1 //===--- SemaOpenMP.cpp - Semantic Analysis for OpenMP constructs ---------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 /// \file
10 /// \brief This file implements semantic analysis for OpenMP directives and
11 /// clauses.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/ASTMutationListener.h"
17 #include "clang/AST/Decl.h"
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/DeclOpenMP.h"
20 #include "clang/AST/StmtCXX.h"
21 #include "clang/AST/StmtOpenMP.h"
22 #include "clang/AST/StmtVisitor.h"
23 #include "clang/Basic/OpenMPKinds.h"
24 #include "clang/Lex/Preprocessor.h"
25 #include "clang/Sema/Initialization.h"
26 #include "clang/Sema/Lookup.h"
27 #include "clang/Sema/Scope.h"
28 #include "clang/Sema/ScopeInfo.h"
29 #include "clang/Sema/SemaInternal.h"
30 using namespace clang;
31 
32 //===----------------------------------------------------------------------===//
33 // Stack of data-sharing attributes for variables
34 //===----------------------------------------------------------------------===//
35 
36 namespace {
37 /// \brief Default data sharing attributes, which can be applied to directive.
38 enum DefaultDataSharingAttributes {
39   DSA_unspecified = 0, /// \brief Data sharing attribute not specified.
40   DSA_none = 1 << 0,   /// \brief Default data sharing attribute 'none'.
41   DSA_shared = 1 << 1  /// \brief Default data sharing attribute 'shared'.
42 };
43 
44 template <class T> struct MatchesAny {
45   explicit MatchesAny(ArrayRef<T> Arr) : Arr(std::move(Arr)) {}
46   bool operator()(T Kind) {
47     for (auto KindEl : Arr)
48       if (KindEl == Kind)
49         return true;
50     return false;
51   }
52 
53 private:
54   ArrayRef<T> Arr;
55 };
56 struct MatchesAlways {
57   MatchesAlways() {}
58   template <class T> bool operator()(T) { return true; }
59 };
60 
61 typedef MatchesAny<OpenMPClauseKind> MatchesAnyClause;
62 typedef MatchesAny<OpenMPDirectiveKind> MatchesAnyDirective;
63 
64 /// \brief Stack for tracking declarations used in OpenMP directives and
65 /// clauses and their data-sharing attributes.
66 class DSAStackTy {
67 public:
68   struct DSAVarData {
69     OpenMPDirectiveKind DKind;
70     OpenMPClauseKind CKind;
71     DeclRefExpr *RefExpr;
72     SourceLocation ImplicitDSALoc;
73     DSAVarData()
74         : DKind(OMPD_unknown), CKind(OMPC_unknown), RefExpr(nullptr),
75           ImplicitDSALoc() {}
76   };
77 
78 private:
79   struct DSAInfo {
80     OpenMPClauseKind Attributes;
81     DeclRefExpr *RefExpr;
82   };
83   typedef llvm::SmallDenseMap<VarDecl *, DSAInfo, 64> DeclSAMapTy;
84   typedef llvm::SmallDenseMap<VarDecl *, DeclRefExpr *, 64> AlignedMapTy;
85   typedef llvm::DenseSet<VarDecl *> LoopControlVariablesSetTy;
86 
87   struct SharingMapTy {
88     DeclSAMapTy SharingMap;
89     AlignedMapTy AlignedMap;
90     LoopControlVariablesSetTy LCVSet;
91     DefaultDataSharingAttributes DefaultAttr;
92     SourceLocation DefaultAttrLoc;
93     OpenMPDirectiveKind Directive;
94     DeclarationNameInfo DirectiveName;
95     Scope *CurScope;
96     SourceLocation ConstructLoc;
97     bool OrderedRegion;
98     unsigned CollapseNumber;
99     SourceLocation InnerTeamsRegionLoc;
100     SharingMapTy(OpenMPDirectiveKind DKind, DeclarationNameInfo Name,
101                  Scope *CurScope, SourceLocation Loc)
102         : SharingMap(), AlignedMap(), LCVSet(), DefaultAttr(DSA_unspecified),
103           Directive(DKind), DirectiveName(std::move(Name)), CurScope(CurScope),
104           ConstructLoc(Loc), OrderedRegion(false), CollapseNumber(1),
105           InnerTeamsRegionLoc() {}
106     SharingMapTy()
107         : SharingMap(), AlignedMap(), LCVSet(), DefaultAttr(DSA_unspecified),
108           Directive(OMPD_unknown), DirectiveName(), CurScope(nullptr),
109           ConstructLoc(), OrderedRegion(false), CollapseNumber(1),
110           InnerTeamsRegionLoc() {}
111   };
112 
113   typedef SmallVector<SharingMapTy, 64> StackTy;
114 
115   /// \brief Stack of used declaration and their data-sharing attributes.
116   StackTy Stack;
117   /// \brief true, if check for DSA must be from parent directive, false, if
118   /// from current directive.
119   bool FromParent;
120   Sema &SemaRef;
121 
122   typedef SmallVector<SharingMapTy, 8>::reverse_iterator reverse_iterator;
123 
124   DSAVarData getDSA(StackTy::reverse_iterator Iter, VarDecl *D);
125 
126   /// \brief Checks if the variable is a local for OpenMP region.
127   bool isOpenMPLocal(VarDecl *D, StackTy::reverse_iterator Iter);
128 
129 public:
130   explicit DSAStackTy(Sema &S) : Stack(1), FromParent(false), SemaRef(S) {}
131 
132   bool isFromParent() const { return FromParent; }
133   void setFromParent(bool Flag) { FromParent = Flag; }
134 
135   void push(OpenMPDirectiveKind DKind, const DeclarationNameInfo &DirName,
136             Scope *CurScope, SourceLocation Loc) {
137     Stack.push_back(SharingMapTy(DKind, DirName, CurScope, Loc));
138     Stack.back().DefaultAttrLoc = Loc;
139   }
140 
141   void pop() {
142     assert(Stack.size() > 1 && "Data-sharing attributes stack is empty!");
143     Stack.pop_back();
144   }
145 
146   /// \brief If 'aligned' declaration for given variable \a D was not seen yet,
147   /// add it and return NULL; otherwise return previous occurrence's expression
148   /// for diagnostics.
149   DeclRefExpr *addUniqueAligned(VarDecl *D, DeclRefExpr *NewDE);
150 
151   /// \brief Register specified variable as loop control variable.
152   void addLoopControlVariable(VarDecl *D);
153   /// \brief Check if the specified variable is a loop control variable for
154   /// current region.
155   bool isLoopControlVariable(VarDecl *D);
156 
157   /// \brief Adds explicit data sharing attribute to the specified declaration.
158   void addDSA(VarDecl *D, DeclRefExpr *E, OpenMPClauseKind A);
159 
160   /// \brief Returns data sharing attributes from top of the stack for the
161   /// specified declaration.
162   DSAVarData getTopDSA(VarDecl *D, bool FromParent);
163   /// \brief Returns data-sharing attributes for the specified declaration.
164   DSAVarData getImplicitDSA(VarDecl *D, bool FromParent);
165   /// \brief Checks if the specified variables has data-sharing attributes which
166   /// match specified \a CPred predicate in any directive which matches \a DPred
167   /// predicate.
168   template <class ClausesPredicate, class DirectivesPredicate>
169   DSAVarData hasDSA(VarDecl *D, ClausesPredicate CPred,
170                     DirectivesPredicate DPred, bool FromParent);
171   /// \brief Checks if the specified variables has data-sharing attributes which
172   /// match specified \a CPred predicate in any innermost directive which
173   /// matches \a DPred predicate.
174   template <class ClausesPredicate, class DirectivesPredicate>
175   DSAVarData hasInnermostDSA(VarDecl *D, ClausesPredicate CPred,
176                              DirectivesPredicate DPred,
177                              bool FromParent);
178   /// \brief Finds a directive which matches specified \a DPred predicate.
179   template <class NamedDirectivesPredicate>
180   bool hasDirective(NamedDirectivesPredicate DPred, bool FromParent);
181 
182   /// \brief Returns currently analyzed directive.
183   OpenMPDirectiveKind getCurrentDirective() const {
184     return Stack.back().Directive;
185   }
186   /// \brief Returns parent directive.
187   OpenMPDirectiveKind getParentDirective() const {
188     if (Stack.size() > 2)
189       return Stack[Stack.size() - 2].Directive;
190     return OMPD_unknown;
191   }
192 
193   /// \brief Set default data sharing attribute to none.
194   void setDefaultDSANone(SourceLocation Loc) {
195     Stack.back().DefaultAttr = DSA_none;
196     Stack.back().DefaultAttrLoc = Loc;
197   }
198   /// \brief Set default data sharing attribute to shared.
199   void setDefaultDSAShared(SourceLocation Loc) {
200     Stack.back().DefaultAttr = DSA_shared;
201     Stack.back().DefaultAttrLoc = Loc;
202   }
203 
204   DefaultDataSharingAttributes getDefaultDSA() const {
205     return Stack.back().DefaultAttr;
206   }
207   SourceLocation getDefaultDSALocation() const {
208     return Stack.back().DefaultAttrLoc;
209   }
210 
211   /// \brief Checks if the specified variable is a threadprivate.
212   bool isThreadPrivate(VarDecl *D) {
213     DSAVarData DVar = getTopDSA(D, false);
214     return isOpenMPThreadPrivate(DVar.CKind);
215   }
216 
217   /// \brief Marks current region as ordered (it has an 'ordered' clause).
218   void setOrderedRegion(bool IsOrdered = true) {
219     Stack.back().OrderedRegion = IsOrdered;
220   }
221   /// \brief Returns true, if parent region is ordered (has associated
222   /// 'ordered' clause), false - otherwise.
223   bool isParentOrderedRegion() const {
224     if (Stack.size() > 2)
225       return Stack[Stack.size() - 2].OrderedRegion;
226     return false;
227   }
228 
229   /// \brief Set collapse value for the region.
230   void setCollapseNumber(unsigned Val) { Stack.back().CollapseNumber = Val; }
231   /// \brief Return collapse value for region.
232   unsigned getCollapseNumber() const {
233     return Stack.back().CollapseNumber;
234   }
235 
236   /// \brief Marks current target region as one with closely nested teams
237   /// region.
238   void setParentTeamsRegionLoc(SourceLocation TeamsRegionLoc) {
239     if (Stack.size() > 2)
240       Stack[Stack.size() - 2].InnerTeamsRegionLoc = TeamsRegionLoc;
241   }
242   /// \brief Returns true, if current region has closely nested teams region.
243   bool hasInnerTeamsRegion() const {
244     return getInnerTeamsRegionLoc().isValid();
245   }
246   /// \brief Returns location of the nested teams region (if any).
247   SourceLocation getInnerTeamsRegionLoc() const {
248     if (Stack.size() > 1)
249       return Stack.back().InnerTeamsRegionLoc;
250     return SourceLocation();
251   }
252 
253   Scope *getCurScope() const { return Stack.back().CurScope; }
254   Scope *getCurScope() { return Stack.back().CurScope; }
255   SourceLocation getConstructLoc() { return Stack.back().ConstructLoc; }
256 };
257 bool isParallelOrTaskRegion(OpenMPDirectiveKind DKind) {
258   return isOpenMPParallelDirective(DKind) || DKind == OMPD_task ||
259          isOpenMPTeamsDirective(DKind) || DKind == OMPD_unknown;
260 }
261 } // namespace
262 
263 DSAStackTy::DSAVarData DSAStackTy::getDSA(StackTy::reverse_iterator Iter,
264                                           VarDecl *D) {
265   D = D->getCanonicalDecl();
266   DSAVarData DVar;
267   if (Iter == std::prev(Stack.rend())) {
268     // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
269     // in a region but not in construct]
270     //  File-scope or namespace-scope variables referenced in called routines
271     //  in the region are shared unless they appear in a threadprivate
272     //  directive.
273     if (!D->isFunctionOrMethodVarDecl() && !isa<ParmVarDecl>(D))
274       DVar.CKind = OMPC_shared;
275 
276     // OpenMP [2.9.1.2, Data-sharing Attribute Rules for Variables Referenced
277     // in a region but not in construct]
278     //  Variables with static storage duration that are declared in called
279     //  routines in the region are shared.
280     if (D->hasGlobalStorage())
281       DVar.CKind = OMPC_shared;
282 
283     return DVar;
284   }
285 
286   DVar.DKind = Iter->Directive;
287   // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
288   // in a Construct, C/C++, predetermined, p.1]
289   // Variables with automatic storage duration that are declared in a scope
290   // inside the construct are private.
291   if (isOpenMPLocal(D, Iter) && D->isLocalVarDecl() &&
292       (D->getStorageClass() == SC_Auto || D->getStorageClass() == SC_None)) {
293     DVar.CKind = OMPC_private;
294     return DVar;
295   }
296 
297   // Explicitly specified attributes and local variables with predetermined
298   // attributes.
299   if (Iter->SharingMap.count(D)) {
300     DVar.RefExpr = Iter->SharingMap[D].RefExpr;
301     DVar.CKind = Iter->SharingMap[D].Attributes;
302     DVar.ImplicitDSALoc = Iter->DefaultAttrLoc;
303     return DVar;
304   }
305 
306   // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
307   // in a Construct, C/C++, implicitly determined, p.1]
308   //  In a parallel or task construct, the data-sharing attributes of these
309   //  variables are determined by the default clause, if present.
310   switch (Iter->DefaultAttr) {
311   case DSA_shared:
312     DVar.CKind = OMPC_shared;
313     DVar.ImplicitDSALoc = Iter->DefaultAttrLoc;
314     return DVar;
315   case DSA_none:
316     return DVar;
317   case DSA_unspecified:
318     // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
319     // in a Construct, implicitly determined, p.2]
320     //  In a parallel construct, if no default clause is present, these
321     //  variables are shared.
322     DVar.ImplicitDSALoc = Iter->DefaultAttrLoc;
323     if (isOpenMPParallelDirective(DVar.DKind) ||
324         isOpenMPTeamsDirective(DVar.DKind)) {
325       DVar.CKind = OMPC_shared;
326       return DVar;
327     }
328 
329     // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
330     // in a Construct, implicitly determined, p.4]
331     //  In a task construct, if no default clause is present, a variable that in
332     //  the enclosing context is determined to be shared by all implicit tasks
333     //  bound to the current team is shared.
334     if (DVar.DKind == OMPD_task) {
335       DSAVarData DVarTemp;
336       for (StackTy::reverse_iterator I = std::next(Iter), EE = Stack.rend();
337            I != EE; ++I) {
338         // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables
339         // Referenced
340         // in a Construct, implicitly determined, p.6]
341         //  In a task construct, if no default clause is present, a variable
342         //  whose data-sharing attribute is not determined by the rules above is
343         //  firstprivate.
344         DVarTemp = getDSA(I, D);
345         if (DVarTemp.CKind != OMPC_shared) {
346           DVar.RefExpr = nullptr;
347           DVar.DKind = OMPD_task;
348           DVar.CKind = OMPC_firstprivate;
349           return DVar;
350         }
351         if (isParallelOrTaskRegion(I->Directive))
352           break;
353       }
354       DVar.DKind = OMPD_task;
355       DVar.CKind =
356           (DVarTemp.CKind == OMPC_unknown) ? OMPC_firstprivate : OMPC_shared;
357       return DVar;
358     }
359   }
360   // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
361   // in a Construct, implicitly determined, p.3]
362   //  For constructs other than task, if no default clause is present, these
363   //  variables inherit their data-sharing attributes from the enclosing
364   //  context.
365   return getDSA(std::next(Iter), D);
366 }
367 
368 DeclRefExpr *DSAStackTy::addUniqueAligned(VarDecl *D, DeclRefExpr *NewDE) {
369   assert(Stack.size() > 1 && "Data sharing attributes stack is empty");
370   D = D->getCanonicalDecl();
371   auto It = Stack.back().AlignedMap.find(D);
372   if (It == Stack.back().AlignedMap.end()) {
373     assert(NewDE && "Unexpected nullptr expr to be added into aligned map");
374     Stack.back().AlignedMap[D] = NewDE;
375     return nullptr;
376   } else {
377     assert(It->second && "Unexpected nullptr expr in the aligned map");
378     return It->second;
379   }
380   return nullptr;
381 }
382 
383 void DSAStackTy::addLoopControlVariable(VarDecl *D) {
384   assert(Stack.size() > 1 && "Data-sharing attributes stack is empty");
385   D = D->getCanonicalDecl();
386   Stack.back().LCVSet.insert(D);
387 }
388 
389 bool DSAStackTy::isLoopControlVariable(VarDecl *D) {
390   assert(Stack.size() > 1 && "Data-sharing attributes stack is empty");
391   D = D->getCanonicalDecl();
392   return Stack.back().LCVSet.count(D) > 0;
393 }
394 
395 void DSAStackTy::addDSA(VarDecl *D, DeclRefExpr *E, OpenMPClauseKind A) {
396   D = D->getCanonicalDecl();
397   if (A == OMPC_threadprivate) {
398     Stack[0].SharingMap[D].Attributes = A;
399     Stack[0].SharingMap[D].RefExpr = E;
400   } else {
401     assert(Stack.size() > 1 && "Data-sharing attributes stack is empty");
402     Stack.back().SharingMap[D].Attributes = A;
403     Stack.back().SharingMap[D].RefExpr = E;
404   }
405 }
406 
407 bool DSAStackTy::isOpenMPLocal(VarDecl *D, StackTy::reverse_iterator Iter) {
408   D = D->getCanonicalDecl();
409   if (Stack.size() > 2) {
410     reverse_iterator I = Iter, E = std::prev(Stack.rend());
411     Scope *TopScope = nullptr;
412     while (I != E && !isParallelOrTaskRegion(I->Directive)) {
413       ++I;
414     }
415     if (I == E)
416       return false;
417     TopScope = I->CurScope ? I->CurScope->getParent() : nullptr;
418     Scope *CurScope = getCurScope();
419     while (CurScope != TopScope && !CurScope->isDeclScope(D)) {
420       CurScope = CurScope->getParent();
421     }
422     return CurScope != TopScope;
423   }
424   return false;
425 }
426 
427 /// \brief Build a variable declaration for OpenMP loop iteration variable.
428 static VarDecl *buildVarDecl(Sema &SemaRef, SourceLocation Loc, QualType Type,
429                              StringRef Name) {
430   DeclContext *DC = SemaRef.CurContext;
431   IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name);
432   TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc);
433   VarDecl *Decl =
434       VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, TInfo, SC_None);
435   Decl->setImplicit();
436   return Decl;
437 }
438 
439 static DeclRefExpr *buildDeclRefExpr(Sema &S, VarDecl *D, QualType Ty,
440                                      SourceLocation Loc,
441                                      bool RefersToCapture = false) {
442   D->setReferenced();
443   D->markUsed(S.Context);
444   return DeclRefExpr::Create(S.getASTContext(), NestedNameSpecifierLoc(),
445                              SourceLocation(), D, RefersToCapture, Loc, Ty,
446                              VK_LValue);
447 }
448 
449 DSAStackTy::DSAVarData DSAStackTy::getTopDSA(VarDecl *D, bool FromParent) {
450   D = D->getCanonicalDecl();
451   DSAVarData DVar;
452 
453   // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
454   // in a Construct, C/C++, predetermined, p.1]
455   //  Variables appearing in threadprivate directives are threadprivate.
456   if (D->getTLSKind() != VarDecl::TLS_None ||
457       (D->getStorageClass() == SC_Register && D->hasAttr<AsmLabelAttr>() &&
458        !D->isLocalVarDecl())) {
459     addDSA(D, buildDeclRefExpr(SemaRef, D, D->getType().getNonReferenceType(),
460                                D->getLocation()),
461            OMPC_threadprivate);
462   }
463   if (Stack[0].SharingMap.count(D)) {
464     DVar.RefExpr = Stack[0].SharingMap[D].RefExpr;
465     DVar.CKind = OMPC_threadprivate;
466     return DVar;
467   }
468 
469   // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
470   // in a Construct, C/C++, predetermined, p.1]
471   // Variables with automatic storage duration that are declared in a scope
472   // inside the construct are private.
473   OpenMPDirectiveKind Kind =
474       FromParent ? getParentDirective() : getCurrentDirective();
475   auto StartI = std::next(Stack.rbegin());
476   auto EndI = std::prev(Stack.rend());
477   if (FromParent && StartI != EndI) {
478     StartI = std::next(StartI);
479   }
480   if (!isParallelOrTaskRegion(Kind)) {
481     if (isOpenMPLocal(D, StartI) &&
482         ((D->isLocalVarDecl() && (D->getStorageClass() == SC_Auto ||
483                                   D->getStorageClass() == SC_None)) ||
484          isa<ParmVarDecl>(D))) {
485       DVar.CKind = OMPC_private;
486       return DVar;
487     }
488 
489     // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
490     // in a Construct, C/C++, predetermined, p.4]
491     //  Static data members are shared.
492     // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
493     // in a Construct, C/C++, predetermined, p.7]
494     //  Variables with static storage duration that are declared in a scope
495     //  inside the construct are shared.
496     if (D->isStaticDataMember() || D->isStaticLocal()) {
497       DSAVarData DVarTemp =
498           hasDSA(D, isOpenMPPrivate, MatchesAlways(), FromParent);
499       if (DVarTemp.CKind != OMPC_unknown && DVarTemp.RefExpr)
500         return DVar;
501 
502       DVar.CKind = OMPC_shared;
503       return DVar;
504     }
505   }
506 
507   QualType Type = D->getType().getNonReferenceType().getCanonicalType();
508   bool IsConstant = Type.isConstant(SemaRef.getASTContext());
509   Type = SemaRef.getASTContext().getBaseElementType(Type);
510   // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
511   // in a Construct, C/C++, predetermined, p.6]
512   //  Variables with const qualified type having no mutable member are
513   //  shared.
514   CXXRecordDecl *RD =
515       SemaRef.getLangOpts().CPlusPlus ? Type->getAsCXXRecordDecl() : nullptr;
516   if (IsConstant &&
517       !(SemaRef.getLangOpts().CPlusPlus && RD && RD->hasMutableFields())) {
518     // Variables with const-qualified type having no mutable member may be
519     // listed in a firstprivate clause, even if they are static data members.
520     DSAVarData DVarTemp = hasDSA(D, MatchesAnyClause(OMPC_firstprivate),
521                                  MatchesAlways(), FromParent);
522     if (DVarTemp.CKind == OMPC_firstprivate && DVarTemp.RefExpr)
523       return DVar;
524 
525     DVar.CKind = OMPC_shared;
526     return DVar;
527   }
528 
529   // Explicitly specified attributes and local variables with predetermined
530   // attributes.
531   auto I = std::prev(StartI);
532   if (I->SharingMap.count(D)) {
533     DVar.RefExpr = I->SharingMap[D].RefExpr;
534     DVar.CKind = I->SharingMap[D].Attributes;
535     DVar.ImplicitDSALoc = I->DefaultAttrLoc;
536   }
537 
538   return DVar;
539 }
540 
541 DSAStackTy::DSAVarData DSAStackTy::getImplicitDSA(VarDecl *D, bool FromParent) {
542   D = D->getCanonicalDecl();
543   auto StartI = Stack.rbegin();
544   auto EndI = std::prev(Stack.rend());
545   if (FromParent && StartI != EndI) {
546     StartI = std::next(StartI);
547   }
548   return getDSA(StartI, D);
549 }
550 
551 template <class ClausesPredicate, class DirectivesPredicate>
552 DSAStackTy::DSAVarData DSAStackTy::hasDSA(VarDecl *D, ClausesPredicate CPred,
553                                           DirectivesPredicate DPred,
554                                           bool FromParent) {
555   D = D->getCanonicalDecl();
556   auto StartI = std::next(Stack.rbegin());
557   auto EndI = std::prev(Stack.rend());
558   if (FromParent && StartI != EndI) {
559     StartI = std::next(StartI);
560   }
561   for (auto I = StartI, EE = EndI; I != EE; ++I) {
562     if (!DPred(I->Directive) && !isParallelOrTaskRegion(I->Directive))
563       continue;
564     DSAVarData DVar = getDSA(I, D);
565     if (CPred(DVar.CKind))
566       return DVar;
567   }
568   return DSAVarData();
569 }
570 
571 template <class ClausesPredicate, class DirectivesPredicate>
572 DSAStackTy::DSAVarData
573 DSAStackTy::hasInnermostDSA(VarDecl *D, ClausesPredicate CPred,
574                             DirectivesPredicate DPred, bool FromParent) {
575   D = D->getCanonicalDecl();
576   auto StartI = std::next(Stack.rbegin());
577   auto EndI = std::prev(Stack.rend());
578   if (FromParent && StartI != EndI) {
579     StartI = std::next(StartI);
580   }
581   for (auto I = StartI, EE = EndI; I != EE; ++I) {
582     if (!DPred(I->Directive))
583       break;
584     DSAVarData DVar = getDSA(I, D);
585     if (CPred(DVar.CKind))
586       return DVar;
587     return DSAVarData();
588   }
589   return DSAVarData();
590 }
591 
592 template <class NamedDirectivesPredicate>
593 bool DSAStackTy::hasDirective(NamedDirectivesPredicate DPred, bool FromParent) {
594   auto StartI = std::next(Stack.rbegin());
595   auto EndI = std::prev(Stack.rend());
596   if (FromParent && StartI != EndI) {
597     StartI = std::next(StartI);
598   }
599   for (auto I = StartI, EE = EndI; I != EE; ++I) {
600     if (DPred(I->Directive, I->DirectiveName, I->ConstructLoc))
601       return true;
602   }
603   return false;
604 }
605 
606 void Sema::InitDataSharingAttributesStack() {
607   VarDataSharingAttributesStack = new DSAStackTy(*this);
608 }
609 
610 #define DSAStack static_cast<DSAStackTy *>(VarDataSharingAttributesStack)
611 
612 bool Sema::IsOpenMPCapturedVar(VarDecl *VD) {
613   assert(LangOpts.OpenMP && "OpenMP is not allowed");
614   VD = VD->getCanonicalDecl();
615   if (DSAStack->getCurrentDirective() != OMPD_unknown) {
616     if (DSAStack->isLoopControlVariable(VD) ||
617         (VD->hasLocalStorage() &&
618          isParallelOrTaskRegion(DSAStack->getCurrentDirective())))
619       return true;
620     auto DVarPrivate = DSAStack->getTopDSA(VD, DSAStack->isFromParent());
621     if (DVarPrivate.CKind != OMPC_unknown && isOpenMPPrivate(DVarPrivate.CKind))
622       return true;
623     DVarPrivate = DSAStack->hasDSA(VD, isOpenMPPrivate, MatchesAlways(),
624                                    DSAStack->isFromParent());
625     return DVarPrivate.CKind != OMPC_unknown;
626   }
627   return false;
628 }
629 
630 void Sema::DestroyDataSharingAttributesStack() { delete DSAStack; }
631 
632 void Sema::StartOpenMPDSABlock(OpenMPDirectiveKind DKind,
633                                const DeclarationNameInfo &DirName,
634                                Scope *CurScope, SourceLocation Loc) {
635   DSAStack->push(DKind, DirName, CurScope, Loc);
636   PushExpressionEvaluationContext(PotentiallyEvaluated);
637 }
638 
639 void Sema::StartOpenMPClauses() {
640   DSAStack->setFromParent(/*Flag=*/true);
641 }
642 
643 void Sema::EndOpenMPClauses() {
644   DSAStack->setFromParent(/*Flag=*/false);
645 }
646 
647 void Sema::EndOpenMPDSABlock(Stmt *CurDirective) {
648   // OpenMP [2.14.3.5, Restrictions, C/C++, p.1]
649   //  A variable of class type (or array thereof) that appears in a lastprivate
650   //  clause requires an accessible, unambiguous default constructor for the
651   //  class type, unless the list item is also specified in a firstprivate
652   //  clause.
653   if (auto D = dyn_cast_or_null<OMPExecutableDirective>(CurDirective)) {
654     for (auto *C : D->clauses()) {
655       if (auto *Clause = dyn_cast<OMPLastprivateClause>(C)) {
656         SmallVector<Expr *, 8> PrivateCopies;
657         for (auto *DE : Clause->varlists()) {
658           if (DE->isValueDependent() || DE->isTypeDependent()) {
659             PrivateCopies.push_back(nullptr);
660             continue;
661           }
662           auto *VD = cast<VarDecl>(cast<DeclRefExpr>(DE)->getDecl());
663           QualType Type = VD->getType();
664           auto DVar = DSAStack->getTopDSA(VD, false);
665           if (DVar.CKind == OMPC_lastprivate) {
666             // Generate helper private variable and initialize it with the
667             // default value. The address of the original variable is replaced
668             // by the address of the new private variable in CodeGen. This new
669             // variable is not added to IdResolver, so the code in the OpenMP
670             // region uses original variable for proper diagnostics.
671             auto *VDPrivate =
672                 buildVarDecl(*this, DE->getExprLoc(), Type.getUnqualifiedType(),
673                              VD->getName());
674             ActOnUninitializedDecl(VDPrivate, /*TypeMayContainAuto=*/false);
675             if (VDPrivate->isInvalidDecl())
676               continue;
677             PrivateCopies.push_back(buildDeclRefExpr(
678                 *this, VDPrivate, DE->getType(), DE->getExprLoc()));
679           } else {
680             // The variable is also a firstprivate, so initialization sequence
681             // for private copy is generated already.
682             PrivateCopies.push_back(nullptr);
683           }
684         }
685         // Set initializers to private copies if no errors were found.
686         if (PrivateCopies.size() == Clause->varlist_size()) {
687           Clause->setPrivateCopies(PrivateCopies);
688         }
689       }
690     }
691   }
692 
693   DSAStack->pop();
694   DiscardCleanupsInEvaluationContext();
695   PopExpressionEvaluationContext();
696 }
697 
698 static bool FinishOpenMPLinearClause(OMPLinearClause &Clause, DeclRefExpr *IV,
699                                      Expr *NumIterations, Sema &SemaRef,
700                                      Scope *S);
701 
702 namespace {
703 
704 class VarDeclFilterCCC : public CorrectionCandidateCallback {
705 private:
706   Sema &SemaRef;
707 
708 public:
709   explicit VarDeclFilterCCC(Sema &S) : SemaRef(S) {}
710   bool ValidateCandidate(const TypoCorrection &Candidate) override {
711     NamedDecl *ND = Candidate.getCorrectionDecl();
712     if (VarDecl *VD = dyn_cast_or_null<VarDecl>(ND)) {
713       return VD->hasGlobalStorage() &&
714              SemaRef.isDeclInScope(ND, SemaRef.getCurLexicalContext(),
715                                    SemaRef.getCurScope());
716     }
717     return false;
718   }
719 };
720 } // namespace
721 
722 ExprResult Sema::ActOnOpenMPIdExpression(Scope *CurScope,
723                                          CXXScopeSpec &ScopeSpec,
724                                          const DeclarationNameInfo &Id) {
725   LookupResult Lookup(*this, Id, LookupOrdinaryName);
726   LookupParsedName(Lookup, CurScope, &ScopeSpec, true);
727 
728   if (Lookup.isAmbiguous())
729     return ExprError();
730 
731   VarDecl *VD;
732   if (!Lookup.isSingleResult()) {
733     if (TypoCorrection Corrected = CorrectTypo(
734             Id, LookupOrdinaryName, CurScope, nullptr,
735             llvm::make_unique<VarDeclFilterCCC>(*this), CTK_ErrorRecovery)) {
736       diagnoseTypo(Corrected,
737                    PDiag(Lookup.empty()
738                              ? diag::err_undeclared_var_use_suggest
739                              : diag::err_omp_expected_var_arg_suggest)
740                        << Id.getName());
741       VD = Corrected.getCorrectionDeclAs<VarDecl>();
742     } else {
743       Diag(Id.getLoc(), Lookup.empty() ? diag::err_undeclared_var_use
744                                        : diag::err_omp_expected_var_arg)
745           << Id.getName();
746       return ExprError();
747     }
748   } else {
749     if (!(VD = Lookup.getAsSingle<VarDecl>())) {
750       Diag(Id.getLoc(), diag::err_omp_expected_var_arg) << Id.getName();
751       Diag(Lookup.getFoundDecl()->getLocation(), diag::note_declared_at);
752       return ExprError();
753     }
754   }
755   Lookup.suppressDiagnostics();
756 
757   // OpenMP [2.9.2, Syntax, C/C++]
758   //   Variables must be file-scope, namespace-scope, or static block-scope.
759   if (!VD->hasGlobalStorage()) {
760     Diag(Id.getLoc(), diag::err_omp_global_var_arg)
761         << getOpenMPDirectiveName(OMPD_threadprivate) << !VD->isStaticLocal();
762     bool IsDecl =
763         VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
764     Diag(VD->getLocation(),
765          IsDecl ? diag::note_previous_decl : diag::note_defined_here)
766         << VD;
767     return ExprError();
768   }
769 
770   VarDecl *CanonicalVD = VD->getCanonicalDecl();
771   NamedDecl *ND = cast<NamedDecl>(CanonicalVD);
772   // OpenMP [2.9.2, Restrictions, C/C++, p.2]
773   //   A threadprivate directive for file-scope variables must appear outside
774   //   any definition or declaration.
775   if (CanonicalVD->getDeclContext()->isTranslationUnit() &&
776       !getCurLexicalContext()->isTranslationUnit()) {
777     Diag(Id.getLoc(), diag::err_omp_var_scope)
778         << getOpenMPDirectiveName(OMPD_threadprivate) << VD;
779     bool IsDecl =
780         VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
781     Diag(VD->getLocation(),
782          IsDecl ? diag::note_previous_decl : diag::note_defined_here)
783         << VD;
784     return ExprError();
785   }
786   // OpenMP [2.9.2, Restrictions, C/C++, p.3]
787   //   A threadprivate directive for static class member variables must appear
788   //   in the class definition, in the same scope in which the member
789   //   variables are declared.
790   if (CanonicalVD->isStaticDataMember() &&
791       !CanonicalVD->getDeclContext()->Equals(getCurLexicalContext())) {
792     Diag(Id.getLoc(), diag::err_omp_var_scope)
793         << getOpenMPDirectiveName(OMPD_threadprivate) << VD;
794     bool IsDecl =
795         VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
796     Diag(VD->getLocation(),
797          IsDecl ? diag::note_previous_decl : diag::note_defined_here)
798         << VD;
799     return ExprError();
800   }
801   // OpenMP [2.9.2, Restrictions, C/C++, p.4]
802   //   A threadprivate directive for namespace-scope variables must appear
803   //   outside any definition or declaration other than the namespace
804   //   definition itself.
805   if (CanonicalVD->getDeclContext()->isNamespace() &&
806       (!getCurLexicalContext()->isFileContext() ||
807        !getCurLexicalContext()->Encloses(CanonicalVD->getDeclContext()))) {
808     Diag(Id.getLoc(), diag::err_omp_var_scope)
809         << getOpenMPDirectiveName(OMPD_threadprivate) << VD;
810     bool IsDecl =
811         VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
812     Diag(VD->getLocation(),
813          IsDecl ? diag::note_previous_decl : diag::note_defined_here)
814         << VD;
815     return ExprError();
816   }
817   // OpenMP [2.9.2, Restrictions, C/C++, p.6]
818   //   A threadprivate directive for static block-scope variables must appear
819   //   in the scope of the variable and not in a nested scope.
820   if (CanonicalVD->isStaticLocal() && CurScope &&
821       !isDeclInScope(ND, getCurLexicalContext(), CurScope)) {
822     Diag(Id.getLoc(), diag::err_omp_var_scope)
823         << getOpenMPDirectiveName(OMPD_threadprivate) << VD;
824     bool IsDecl =
825         VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
826     Diag(VD->getLocation(),
827          IsDecl ? diag::note_previous_decl : diag::note_defined_here)
828         << VD;
829     return ExprError();
830   }
831 
832   // OpenMP [2.9.2, Restrictions, C/C++, p.2-6]
833   //   A threadprivate directive must lexically precede all references to any
834   //   of the variables in its list.
835   if (VD->isUsed() && !DSAStack->isThreadPrivate(VD)) {
836     Diag(Id.getLoc(), diag::err_omp_var_used)
837         << getOpenMPDirectiveName(OMPD_threadprivate) << VD;
838     return ExprError();
839   }
840 
841   QualType ExprType = VD->getType().getNonReferenceType();
842   ExprResult DE = buildDeclRefExpr(*this, VD, ExprType, Id.getLoc());
843   return DE;
844 }
845 
846 Sema::DeclGroupPtrTy
847 Sema::ActOnOpenMPThreadprivateDirective(SourceLocation Loc,
848                                         ArrayRef<Expr *> VarList) {
849   if (OMPThreadPrivateDecl *D = CheckOMPThreadPrivateDecl(Loc, VarList)) {
850     CurContext->addDecl(D);
851     return DeclGroupPtrTy::make(DeclGroupRef(D));
852   }
853   return DeclGroupPtrTy();
854 }
855 
856 namespace {
857 class LocalVarRefChecker : public ConstStmtVisitor<LocalVarRefChecker, bool> {
858   Sema &SemaRef;
859 
860 public:
861   bool VisitDeclRefExpr(const DeclRefExpr *E) {
862     if (auto VD = dyn_cast<VarDecl>(E->getDecl())) {
863       if (VD->hasLocalStorage()) {
864         SemaRef.Diag(E->getLocStart(),
865                      diag::err_omp_local_var_in_threadprivate_init)
866             << E->getSourceRange();
867         SemaRef.Diag(VD->getLocation(), diag::note_defined_here)
868             << VD << VD->getSourceRange();
869         return true;
870       }
871     }
872     return false;
873   }
874   bool VisitStmt(const Stmt *S) {
875     for (auto Child : S->children()) {
876       if (Child && Visit(Child))
877         return true;
878     }
879     return false;
880   }
881   explicit LocalVarRefChecker(Sema &SemaRef) : SemaRef(SemaRef) {}
882 };
883 } // namespace
884 
885 OMPThreadPrivateDecl *
886 Sema::CheckOMPThreadPrivateDecl(SourceLocation Loc, ArrayRef<Expr *> VarList) {
887   SmallVector<Expr *, 8> Vars;
888   for (auto &RefExpr : VarList) {
889     DeclRefExpr *DE = cast<DeclRefExpr>(RefExpr);
890     VarDecl *VD = cast<VarDecl>(DE->getDecl());
891     SourceLocation ILoc = DE->getExprLoc();
892 
893     QualType QType = VD->getType();
894     if (QType->isDependentType() || QType->isInstantiationDependentType()) {
895       // It will be analyzed later.
896       Vars.push_back(DE);
897       continue;
898     }
899 
900     // OpenMP [2.9.2, Restrictions, C/C++, p.10]
901     //   A threadprivate variable must not have an incomplete type.
902     if (RequireCompleteType(ILoc, VD->getType(),
903                             diag::err_omp_threadprivate_incomplete_type)) {
904       continue;
905     }
906 
907     // OpenMP [2.9.2, Restrictions, C/C++, p.10]
908     //   A threadprivate variable must not have a reference type.
909     if (VD->getType()->isReferenceType()) {
910       Diag(ILoc, diag::err_omp_ref_type_arg)
911           << getOpenMPDirectiveName(OMPD_threadprivate) << VD->getType();
912       bool IsDecl =
913           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
914       Diag(VD->getLocation(),
915            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
916           << VD;
917       continue;
918     }
919 
920     // Check if this is a TLS variable.
921     if (VD->getTLSKind() != VarDecl::TLS_None ||
922         (VD->getStorageClass() == SC_Register && VD->hasAttr<AsmLabelAttr>() &&
923          !VD->isLocalVarDecl())) {
924       Diag(ILoc, diag::err_omp_var_thread_local)
925           << VD << ((VD->getTLSKind() != VarDecl::TLS_None) ? 0 : 1);
926       bool IsDecl =
927           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
928       Diag(VD->getLocation(),
929            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
930           << VD;
931       continue;
932     }
933 
934     // Check if initial value of threadprivate variable reference variable with
935     // local storage (it is not supported by runtime).
936     if (auto Init = VD->getAnyInitializer()) {
937       LocalVarRefChecker Checker(*this);
938       if (Checker.Visit(Init))
939         continue;
940     }
941 
942     Vars.push_back(RefExpr);
943     DSAStack->addDSA(VD, DE, OMPC_threadprivate);
944     VD->addAttr(OMPThreadPrivateDeclAttr::CreateImplicit(
945         Context, SourceRange(Loc, Loc)));
946     if (auto *ML = Context.getASTMutationListener())
947       ML->DeclarationMarkedOpenMPThreadPrivate(VD);
948   }
949   OMPThreadPrivateDecl *D = nullptr;
950   if (!Vars.empty()) {
951     D = OMPThreadPrivateDecl::Create(Context, getCurLexicalContext(), Loc,
952                                      Vars);
953     D->setAccess(AS_public);
954   }
955   return D;
956 }
957 
958 static void ReportOriginalDSA(Sema &SemaRef, DSAStackTy *Stack,
959                               const VarDecl *VD, DSAStackTy::DSAVarData DVar,
960                               bool IsLoopIterVar = false) {
961   if (DVar.RefExpr) {
962     SemaRef.Diag(DVar.RefExpr->getExprLoc(), diag::note_omp_explicit_dsa)
963         << getOpenMPClauseName(DVar.CKind);
964     return;
965   }
966   enum {
967     PDSA_StaticMemberShared,
968     PDSA_StaticLocalVarShared,
969     PDSA_LoopIterVarPrivate,
970     PDSA_LoopIterVarLinear,
971     PDSA_LoopIterVarLastprivate,
972     PDSA_ConstVarShared,
973     PDSA_GlobalVarShared,
974     PDSA_TaskVarFirstprivate,
975     PDSA_LocalVarPrivate,
976     PDSA_Implicit
977   } Reason = PDSA_Implicit;
978   bool ReportHint = false;
979   auto ReportLoc = VD->getLocation();
980   if (IsLoopIterVar) {
981     if (DVar.CKind == OMPC_private)
982       Reason = PDSA_LoopIterVarPrivate;
983     else if (DVar.CKind == OMPC_lastprivate)
984       Reason = PDSA_LoopIterVarLastprivate;
985     else
986       Reason = PDSA_LoopIterVarLinear;
987   } else if (DVar.DKind == OMPD_task && DVar.CKind == OMPC_firstprivate) {
988     Reason = PDSA_TaskVarFirstprivate;
989     ReportLoc = DVar.ImplicitDSALoc;
990   } else if (VD->isStaticLocal())
991     Reason = PDSA_StaticLocalVarShared;
992   else if (VD->isStaticDataMember())
993     Reason = PDSA_StaticMemberShared;
994   else if (VD->isFileVarDecl())
995     Reason = PDSA_GlobalVarShared;
996   else if (VD->getType().isConstant(SemaRef.getASTContext()))
997     Reason = PDSA_ConstVarShared;
998   else if (VD->isLocalVarDecl() && DVar.CKind == OMPC_private) {
999     ReportHint = true;
1000     Reason = PDSA_LocalVarPrivate;
1001   }
1002   if (Reason != PDSA_Implicit) {
1003     SemaRef.Diag(ReportLoc, diag::note_omp_predetermined_dsa)
1004         << Reason << ReportHint
1005         << getOpenMPDirectiveName(Stack->getCurrentDirective());
1006   } else if (DVar.ImplicitDSALoc.isValid()) {
1007     SemaRef.Diag(DVar.ImplicitDSALoc, diag::note_omp_implicit_dsa)
1008         << getOpenMPClauseName(DVar.CKind);
1009   }
1010 }
1011 
1012 namespace {
1013 class DSAAttrChecker : public StmtVisitor<DSAAttrChecker, void> {
1014   DSAStackTy *Stack;
1015   Sema &SemaRef;
1016   bool ErrorFound;
1017   CapturedStmt *CS;
1018   llvm::SmallVector<Expr *, 8> ImplicitFirstprivate;
1019   llvm::DenseMap<VarDecl *, Expr *> VarsWithInheritedDSA;
1020 
1021 public:
1022   void VisitDeclRefExpr(DeclRefExpr *E) {
1023     if (auto *VD = dyn_cast<VarDecl>(E->getDecl())) {
1024       // Skip internally declared variables.
1025       if (VD->isLocalVarDecl() && !CS->capturesVariable(VD))
1026         return;
1027 
1028       auto DVar = Stack->getTopDSA(VD, false);
1029       // Check if the variable has explicit DSA set and stop analysis if it so.
1030       if (DVar.RefExpr) return;
1031 
1032       auto ELoc = E->getExprLoc();
1033       auto DKind = Stack->getCurrentDirective();
1034       // The default(none) clause requires that each variable that is referenced
1035       // in the construct, and does not have a predetermined data-sharing
1036       // attribute, must have its data-sharing attribute explicitly determined
1037       // by being listed in a data-sharing attribute clause.
1038       if (DVar.CKind == OMPC_unknown && Stack->getDefaultDSA() == DSA_none &&
1039           isParallelOrTaskRegion(DKind) &&
1040           VarsWithInheritedDSA.count(VD) == 0) {
1041         VarsWithInheritedDSA[VD] = E;
1042         return;
1043       }
1044 
1045       // OpenMP [2.9.3.6, Restrictions, p.2]
1046       //  A list item that appears in a reduction clause of the innermost
1047       //  enclosing worksharing or parallel construct may not be accessed in an
1048       //  explicit task.
1049       DVar = Stack->hasInnermostDSA(VD, MatchesAnyClause(OMPC_reduction),
1050                                     [](OpenMPDirectiveKind K) -> bool {
1051                                       return isOpenMPParallelDirective(K) ||
1052                                              isOpenMPWorksharingDirective(K) ||
1053                                              isOpenMPTeamsDirective(K);
1054                                     },
1055                                     false);
1056       if (DKind == OMPD_task && DVar.CKind == OMPC_reduction) {
1057         ErrorFound = true;
1058         SemaRef.Diag(ELoc, diag::err_omp_reduction_in_task);
1059         ReportOriginalDSA(SemaRef, Stack, VD, DVar);
1060         return;
1061       }
1062 
1063       // Define implicit data-sharing attributes for task.
1064       DVar = Stack->getImplicitDSA(VD, false);
1065       if (DKind == OMPD_task && DVar.CKind != OMPC_shared)
1066         ImplicitFirstprivate.push_back(E);
1067     }
1068   }
1069   void VisitOMPExecutableDirective(OMPExecutableDirective *S) {
1070     for (auto *C : S->clauses()) {
1071       // Skip analysis of arguments of implicitly defined firstprivate clause
1072       // for task directives.
1073       if (C && (!isa<OMPFirstprivateClause>(C) || C->getLocStart().isValid()))
1074         for (auto *CC : C->children()) {
1075           if (CC)
1076             Visit(CC);
1077         }
1078     }
1079   }
1080   void VisitStmt(Stmt *S) {
1081     for (auto *C : S->children()) {
1082       if (C && !isa<OMPExecutableDirective>(C))
1083         Visit(C);
1084     }
1085   }
1086 
1087   bool isErrorFound() { return ErrorFound; }
1088   ArrayRef<Expr *> getImplicitFirstprivate() { return ImplicitFirstprivate; }
1089   llvm::DenseMap<VarDecl *, Expr *> &getVarsWithInheritedDSA() {
1090     return VarsWithInheritedDSA;
1091   }
1092 
1093   DSAAttrChecker(DSAStackTy *S, Sema &SemaRef, CapturedStmt *CS)
1094       : Stack(S), SemaRef(SemaRef), ErrorFound(false), CS(CS) {}
1095 };
1096 } // namespace
1097 
1098 void Sema::ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope) {
1099   switch (DKind) {
1100   case OMPD_parallel: {
1101     QualType KmpInt32Ty = Context.getIntTypeForBitwidth(32, 1);
1102     QualType KmpInt32PtrTy = Context.getPointerType(KmpInt32Ty);
1103     Sema::CapturedParamNameType Params[] = {
1104         std::make_pair(".global_tid.", KmpInt32PtrTy),
1105         std::make_pair(".bound_tid.", KmpInt32PtrTy),
1106         std::make_pair(StringRef(), QualType()) // __context with shared vars
1107     };
1108     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1109                              Params);
1110     break;
1111   }
1112   case OMPD_simd: {
1113     Sema::CapturedParamNameType Params[] = {
1114         std::make_pair(StringRef(), QualType()) // __context with shared vars
1115     };
1116     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1117                              Params);
1118     break;
1119   }
1120   case OMPD_for: {
1121     Sema::CapturedParamNameType Params[] = {
1122         std::make_pair(StringRef(), QualType()) // __context with shared vars
1123     };
1124     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1125                              Params);
1126     break;
1127   }
1128   case OMPD_for_simd: {
1129     Sema::CapturedParamNameType Params[] = {
1130         std::make_pair(StringRef(), QualType()) // __context with shared vars
1131     };
1132     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1133                              Params);
1134     break;
1135   }
1136   case OMPD_sections: {
1137     Sema::CapturedParamNameType Params[] = {
1138         std::make_pair(StringRef(), QualType()) // __context with shared vars
1139     };
1140     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1141                              Params);
1142     break;
1143   }
1144   case OMPD_section: {
1145     Sema::CapturedParamNameType Params[] = {
1146         std::make_pair(StringRef(), QualType()) // __context with shared vars
1147     };
1148     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1149                              Params);
1150     break;
1151   }
1152   case OMPD_single: {
1153     Sema::CapturedParamNameType Params[] = {
1154         std::make_pair(StringRef(), QualType()) // __context with shared vars
1155     };
1156     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1157                              Params);
1158     break;
1159   }
1160   case OMPD_master: {
1161     Sema::CapturedParamNameType Params[] = {
1162         std::make_pair(StringRef(), QualType()) // __context with shared vars
1163     };
1164     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1165                              Params);
1166     break;
1167   }
1168   case OMPD_critical: {
1169     Sema::CapturedParamNameType Params[] = {
1170         std::make_pair(StringRef(), QualType()) // __context with shared vars
1171     };
1172     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1173                              Params);
1174     break;
1175   }
1176   case OMPD_parallel_for: {
1177     QualType KmpInt32Ty = Context.getIntTypeForBitwidth(32, 1);
1178     QualType KmpInt32PtrTy = Context.getPointerType(KmpInt32Ty);
1179     Sema::CapturedParamNameType Params[] = {
1180         std::make_pair(".global_tid.", KmpInt32PtrTy),
1181         std::make_pair(".bound_tid.", KmpInt32PtrTy),
1182         std::make_pair(StringRef(), QualType()) // __context with shared vars
1183     };
1184     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1185                              Params);
1186     break;
1187   }
1188   case OMPD_parallel_for_simd: {
1189     QualType KmpInt32Ty = Context.getIntTypeForBitwidth(32, 1);
1190     QualType KmpInt32PtrTy = Context.getPointerType(KmpInt32Ty);
1191     Sema::CapturedParamNameType Params[] = {
1192         std::make_pair(".global_tid.", KmpInt32PtrTy),
1193         std::make_pair(".bound_tid.", KmpInt32PtrTy),
1194         std::make_pair(StringRef(), QualType()) // __context with shared vars
1195     };
1196     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1197                              Params);
1198     break;
1199   }
1200   case OMPD_parallel_sections: {
1201     QualType KmpInt32Ty = Context.getIntTypeForBitwidth(32, 1);
1202     QualType KmpInt32PtrTy = Context.getPointerType(KmpInt32Ty);
1203     Sema::CapturedParamNameType Params[] = {
1204         std::make_pair(".global_tid.", KmpInt32PtrTy),
1205         std::make_pair(".bound_tid.", KmpInt32PtrTy),
1206         std::make_pair(StringRef(), QualType()) // __context with shared vars
1207     };
1208     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1209                              Params);
1210     break;
1211   }
1212   case OMPD_task: {
1213     QualType KmpInt32Ty = Context.getIntTypeForBitwidth(32, 1);
1214     QualType Args[] = {Context.VoidPtrTy.withConst().withRestrict()};
1215     FunctionProtoType::ExtProtoInfo EPI;
1216     EPI.Variadic = true;
1217     QualType CopyFnType = Context.getFunctionType(Context.VoidTy, Args, EPI);
1218     Sema::CapturedParamNameType Params[] = {
1219         std::make_pair(".global_tid.", KmpInt32Ty),
1220         std::make_pair(".part_id.", KmpInt32Ty),
1221         std::make_pair(".privates.",
1222                        Context.VoidPtrTy.withConst().withRestrict()),
1223         std::make_pair(
1224             ".copy_fn.",
1225             Context.getPointerType(CopyFnType).withConst().withRestrict()),
1226         std::make_pair(StringRef(), QualType()) // __context with shared vars
1227     };
1228     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1229                              Params);
1230     // Mark this captured region as inlined, because we don't use outlined
1231     // function directly.
1232     getCurCapturedRegion()->TheCapturedDecl->addAttr(
1233         AlwaysInlineAttr::CreateImplicit(
1234             Context, AlwaysInlineAttr::Keyword_forceinline, SourceRange()));
1235     break;
1236   }
1237   case OMPD_ordered: {
1238     Sema::CapturedParamNameType Params[] = {
1239         std::make_pair(StringRef(), QualType()) // __context with shared vars
1240     };
1241     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1242                              Params);
1243     break;
1244   }
1245   case OMPD_atomic: {
1246     Sema::CapturedParamNameType Params[] = {
1247         std::make_pair(StringRef(), QualType()) // __context with shared vars
1248     };
1249     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1250                              Params);
1251     break;
1252   }
1253   case OMPD_target: {
1254     Sema::CapturedParamNameType Params[] = {
1255         std::make_pair(StringRef(), QualType()) // __context with shared vars
1256     };
1257     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1258                              Params);
1259     break;
1260   }
1261   case OMPD_teams: {
1262     QualType KmpInt32Ty = Context.getIntTypeForBitwidth(32, 1);
1263     QualType KmpInt32PtrTy = Context.getPointerType(KmpInt32Ty);
1264     Sema::CapturedParamNameType Params[] = {
1265         std::make_pair(".global_tid.", KmpInt32PtrTy),
1266         std::make_pair(".bound_tid.", KmpInt32PtrTy),
1267         std::make_pair(StringRef(), QualType()) // __context with shared vars
1268     };
1269     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1270                              Params);
1271     break;
1272   }
1273   case OMPD_taskgroup: {
1274     Sema::CapturedParamNameType Params[] = {
1275         std::make_pair(StringRef(), QualType()) // __context with shared vars
1276     };
1277     ActOnCapturedRegionStart(DSAStack->getConstructLoc(), CurScope, CR_OpenMP,
1278                              Params);
1279     break;
1280   }
1281   case OMPD_threadprivate:
1282   case OMPD_taskyield:
1283   case OMPD_barrier:
1284   case OMPD_taskwait:
1285   case OMPD_flush:
1286     llvm_unreachable("OpenMP Directive is not allowed");
1287   case OMPD_unknown:
1288     llvm_unreachable("Unknown OpenMP directive");
1289   }
1290 }
1291 
1292 StmtResult Sema::ActOnOpenMPRegionEnd(StmtResult S,
1293                                       ArrayRef<OMPClause *> Clauses) {
1294   if (!S.isUsable()) {
1295     ActOnCapturedRegionError();
1296     return StmtError();
1297   }
1298   // This is required for proper codegen.
1299   for (auto *Clause : Clauses) {
1300     if (isOpenMPPrivate(Clause->getClauseKind()) ||
1301         Clause->getClauseKind() == OMPC_copyprivate) {
1302       // Mark all variables in private list clauses as used in inner region.
1303       for (auto *VarRef : Clause->children()) {
1304         if (auto *E = cast_or_null<Expr>(VarRef)) {
1305           MarkDeclarationsReferencedInExpr(E);
1306         }
1307       }
1308     } else if (isParallelOrTaskRegion(DSAStack->getCurrentDirective()) &&
1309                Clause->getClauseKind() == OMPC_schedule) {
1310       // Mark all variables in private list clauses as used in inner region.
1311       // Required for proper codegen of combined directives.
1312       // TODO: add processing for other clauses.
1313       if (auto *E = cast_or_null<Expr>(
1314               cast<OMPScheduleClause>(Clause)->getHelperChunkSize())) {
1315           MarkDeclarationsReferencedInExpr(E);
1316         }
1317     }
1318   }
1319   return ActOnCapturedRegionEnd(S.get());
1320 }
1321 
1322 static bool CheckNestingOfRegions(Sema &SemaRef, DSAStackTy *Stack,
1323                                   OpenMPDirectiveKind CurrentRegion,
1324                                   const DeclarationNameInfo &CurrentName,
1325                                   SourceLocation StartLoc) {
1326   // Allowed nesting of constructs
1327   // +------------------+-----------------+------------------------------------+
1328   // | Parent directive | Child directive | Closely (!), No-Closely(+), Both(*)|
1329   // +------------------+-----------------+------------------------------------+
1330   // | parallel         | parallel        | *                                  |
1331   // | parallel         | for             | *                                  |
1332   // | parallel         | for simd        | *                                  |
1333   // | parallel         | master          | *                                  |
1334   // | parallel         | critical        | *                                  |
1335   // | parallel         | simd            | *                                  |
1336   // | parallel         | sections        | *                                  |
1337   // | parallel         | section         | +                                  |
1338   // | parallel         | single          | *                                  |
1339   // | parallel         | parallel for    | *                                  |
1340   // | parallel         |parallel for simd| *                                  |
1341   // | parallel         |parallel sections| *                                  |
1342   // | parallel         | task            | *                                  |
1343   // | parallel         | taskyield       | *                                  |
1344   // | parallel         | barrier         | *                                  |
1345   // | parallel         | taskwait        | *                                  |
1346   // | parallel         | taskgroup       | *                                  |
1347   // | parallel         | flush           | *                                  |
1348   // | parallel         | ordered         | +                                  |
1349   // | parallel         | atomic          | *                                  |
1350   // | parallel         | target          | *                                  |
1351   // | parallel         | teams           | +                                  |
1352   // +------------------+-----------------+------------------------------------+
1353   // | for              | parallel        | *                                  |
1354   // | for              | for             | +                                  |
1355   // | for              | for simd        | +                                  |
1356   // | for              | master          | +                                  |
1357   // | for              | critical        | *                                  |
1358   // | for              | simd            | *                                  |
1359   // | for              | sections        | +                                  |
1360   // | for              | section         | +                                  |
1361   // | for              | single          | +                                  |
1362   // | for              | parallel for    | *                                  |
1363   // | for              |parallel for simd| *                                  |
1364   // | for              |parallel sections| *                                  |
1365   // | for              | task            | *                                  |
1366   // | for              | taskyield       | *                                  |
1367   // | for              | barrier         | +                                  |
1368   // | for              | taskwait        | *                                  |
1369   // | for              | taskgroup       | *                                  |
1370   // | for              | flush           | *                                  |
1371   // | for              | ordered         | * (if construct is ordered)        |
1372   // | for              | atomic          | *                                  |
1373   // | for              | target          | *                                  |
1374   // | for              | teams           | +                                  |
1375   // +------------------+-----------------+------------------------------------+
1376   // | master           | parallel        | *                                  |
1377   // | master           | for             | +                                  |
1378   // | master           | for simd        | +                                  |
1379   // | master           | master          | *                                  |
1380   // | master           | critical        | *                                  |
1381   // | master           | simd            | *                                  |
1382   // | master           | sections        | +                                  |
1383   // | master           | section         | +                                  |
1384   // | master           | single          | +                                  |
1385   // | master           | parallel for    | *                                  |
1386   // | master           |parallel for simd| *                                  |
1387   // | master           |parallel sections| *                                  |
1388   // | master           | task            | *                                  |
1389   // | master           | taskyield       | *                                  |
1390   // | master           | barrier         | +                                  |
1391   // | master           | taskwait        | *                                  |
1392   // | master           | taskgroup       | *                                  |
1393   // | master           | flush           | *                                  |
1394   // | master           | ordered         | +                                  |
1395   // | master           | atomic          | *                                  |
1396   // | master           | target          | *                                  |
1397   // | master           | teams           | +                                  |
1398   // +------------------+-----------------+------------------------------------+
1399   // | critical         | parallel        | *                                  |
1400   // | critical         | for             | +                                  |
1401   // | critical         | for simd        | +                                  |
1402   // | critical         | master          | *                                  |
1403   // | critical         | critical        | * (should have different names)    |
1404   // | critical         | simd            | *                                  |
1405   // | critical         | sections        | +                                  |
1406   // | critical         | section         | +                                  |
1407   // | critical         | single          | +                                  |
1408   // | critical         | parallel for    | *                                  |
1409   // | critical         |parallel for simd| *                                  |
1410   // | critical         |parallel sections| *                                  |
1411   // | critical         | task            | *                                  |
1412   // | critical         | taskyield       | *                                  |
1413   // | critical         | barrier         | +                                  |
1414   // | critical         | taskwait        | *                                  |
1415   // | critical         | taskgroup       | *                                  |
1416   // | critical         | ordered         | +                                  |
1417   // | critical         | atomic          | *                                  |
1418   // | critical         | target          | *                                  |
1419   // | critical         | teams           | +                                  |
1420   // +------------------+-----------------+------------------------------------+
1421   // | simd             | parallel        |                                    |
1422   // | simd             | for             |                                    |
1423   // | simd             | for simd        |                                    |
1424   // | simd             | master          |                                    |
1425   // | simd             | critical        |                                    |
1426   // | simd             | simd            |                                    |
1427   // | simd             | sections        |                                    |
1428   // | simd             | section         |                                    |
1429   // | simd             | single          |                                    |
1430   // | simd             | parallel for    |                                    |
1431   // | simd             |parallel for simd|                                    |
1432   // | simd             |parallel sections|                                    |
1433   // | simd             | task            |                                    |
1434   // | simd             | taskyield       |                                    |
1435   // | simd             | barrier         |                                    |
1436   // | simd             | taskwait        |                                    |
1437   // | simd             | taskgroup       |                                    |
1438   // | simd             | flush           |                                    |
1439   // | simd             | ordered         |                                    |
1440   // | simd             | atomic          |                                    |
1441   // | simd             | target          |                                    |
1442   // | simd             | teams           |                                    |
1443   // +------------------+-----------------+------------------------------------+
1444   // | for simd         | parallel        |                                    |
1445   // | for simd         | for             |                                    |
1446   // | for simd         | for simd        |                                    |
1447   // | for simd         | master          |                                    |
1448   // | for simd         | critical        |                                    |
1449   // | for simd         | simd            |                                    |
1450   // | for simd         | sections        |                                    |
1451   // | for simd         | section         |                                    |
1452   // | for simd         | single          |                                    |
1453   // | for simd         | parallel for    |                                    |
1454   // | for simd         |parallel for simd|                                    |
1455   // | for simd         |parallel sections|                                    |
1456   // | for simd         | task            |                                    |
1457   // | for simd         | taskyield       |                                    |
1458   // | for simd         | barrier         |                                    |
1459   // | for simd         | taskwait        |                                    |
1460   // | for simd         | taskgroup       |                                    |
1461   // | for simd         | flush           |                                    |
1462   // | for simd         | ordered         |                                    |
1463   // | for simd         | atomic          |                                    |
1464   // | for simd         | target          |                                    |
1465   // | for simd         | teams           |                                    |
1466   // +------------------+-----------------+------------------------------------+
1467   // | parallel for simd| parallel        |                                    |
1468   // | parallel for simd| for             |                                    |
1469   // | parallel for simd| for simd        |                                    |
1470   // | parallel for simd| master          |                                    |
1471   // | parallel for simd| critical        |                                    |
1472   // | parallel for simd| simd            |                                    |
1473   // | parallel for simd| sections        |                                    |
1474   // | parallel for simd| section         |                                    |
1475   // | parallel for simd| single          |                                    |
1476   // | parallel for simd| parallel for    |                                    |
1477   // | parallel for simd|parallel for simd|                                    |
1478   // | parallel for simd|parallel sections|                                    |
1479   // | parallel for simd| task            |                                    |
1480   // | parallel for simd| taskyield       |                                    |
1481   // | parallel for simd| barrier         |                                    |
1482   // | parallel for simd| taskwait        |                                    |
1483   // | parallel for simd| taskgroup       |                                    |
1484   // | parallel for simd| flush           |                                    |
1485   // | parallel for simd| ordered         |                                    |
1486   // | parallel for simd| atomic          |                                    |
1487   // | parallel for simd| target          |                                    |
1488   // | parallel for simd| teams           |                                    |
1489   // +------------------+-----------------+------------------------------------+
1490   // | sections         | parallel        | *                                  |
1491   // | sections         | for             | +                                  |
1492   // | sections         | for simd        | +                                  |
1493   // | sections         | master          | +                                  |
1494   // | sections         | critical        | *                                  |
1495   // | sections         | simd            | *                                  |
1496   // | sections         | sections        | +                                  |
1497   // | sections         | section         | *                                  |
1498   // | sections         | single          | +                                  |
1499   // | sections         | parallel for    | *                                  |
1500   // | sections         |parallel for simd| *                                  |
1501   // | sections         |parallel sections| *                                  |
1502   // | sections         | task            | *                                  |
1503   // | sections         | taskyield       | *                                  |
1504   // | sections         | barrier         | +                                  |
1505   // | sections         | taskwait        | *                                  |
1506   // | sections         | taskgroup       | *                                  |
1507   // | sections         | flush           | *                                  |
1508   // | sections         | ordered         | +                                  |
1509   // | sections         | atomic          | *                                  |
1510   // | sections         | target          | *                                  |
1511   // | sections         | teams           | +                                  |
1512   // +------------------+-----------------+------------------------------------+
1513   // | section          | parallel        | *                                  |
1514   // | section          | for             | +                                  |
1515   // | section          | for simd        | +                                  |
1516   // | section          | master          | +                                  |
1517   // | section          | critical        | *                                  |
1518   // | section          | simd            | *                                  |
1519   // | section          | sections        | +                                  |
1520   // | section          | section         | +                                  |
1521   // | section          | single          | +                                  |
1522   // | section          | parallel for    | *                                  |
1523   // | section          |parallel for simd| *                                  |
1524   // | section          |parallel sections| *                                  |
1525   // | section          | task            | *                                  |
1526   // | section          | taskyield       | *                                  |
1527   // | section          | barrier         | +                                  |
1528   // | section          | taskwait        | *                                  |
1529   // | section          | taskgroup       | *                                  |
1530   // | section          | flush           | *                                  |
1531   // | section          | ordered         | +                                  |
1532   // | section          | atomic          | *                                  |
1533   // | section          | target          | *                                  |
1534   // | section          | teams           | +                                  |
1535   // +------------------+-----------------+------------------------------------+
1536   // | single           | parallel        | *                                  |
1537   // | single           | for             | +                                  |
1538   // | single           | for simd        | +                                  |
1539   // | single           | master          | +                                  |
1540   // | single           | critical        | *                                  |
1541   // | single           | simd            | *                                  |
1542   // | single           | sections        | +                                  |
1543   // | single           | section         | +                                  |
1544   // | single           | single          | +                                  |
1545   // | single           | parallel for    | *                                  |
1546   // | single           |parallel for simd| *                                  |
1547   // | single           |parallel sections| *                                  |
1548   // | single           | task            | *                                  |
1549   // | single           | taskyield       | *                                  |
1550   // | single           | barrier         | +                                  |
1551   // | single           | taskwait        | *                                  |
1552   // | single           | taskgroup       | *                                  |
1553   // | single           | flush           | *                                  |
1554   // | single           | ordered         | +                                  |
1555   // | single           | atomic          | *                                  |
1556   // | single           | target          | *                                  |
1557   // | single           | teams           | +                                  |
1558   // +------------------+-----------------+------------------------------------+
1559   // | parallel for     | parallel        | *                                  |
1560   // | parallel for     | for             | +                                  |
1561   // | parallel for     | for simd        | +                                  |
1562   // | parallel for     | master          | +                                  |
1563   // | parallel for     | critical        | *                                  |
1564   // | parallel for     | simd            | *                                  |
1565   // | parallel for     | sections        | +                                  |
1566   // | parallel for     | section         | +                                  |
1567   // | parallel for     | single          | +                                  |
1568   // | parallel for     | parallel for    | *                                  |
1569   // | parallel for     |parallel for simd| *                                  |
1570   // | parallel for     |parallel sections| *                                  |
1571   // | parallel for     | task            | *                                  |
1572   // | parallel for     | taskyield       | *                                  |
1573   // | parallel for     | barrier         | +                                  |
1574   // | parallel for     | taskwait        | *                                  |
1575   // | parallel for     | taskgroup       | *                                  |
1576   // | parallel for     | flush           | *                                  |
1577   // | parallel for     | ordered         | * (if construct is ordered)        |
1578   // | parallel for     | atomic          | *                                  |
1579   // | parallel for     | target          | *                                  |
1580   // | parallel for     | teams           | +                                  |
1581   // +------------------+-----------------+------------------------------------+
1582   // | parallel sections| parallel        | *                                  |
1583   // | parallel sections| for             | +                                  |
1584   // | parallel sections| for simd        | +                                  |
1585   // | parallel sections| master          | +                                  |
1586   // | parallel sections| critical        | +                                  |
1587   // | parallel sections| simd            | *                                  |
1588   // | parallel sections| sections        | +                                  |
1589   // | parallel sections| section         | *                                  |
1590   // | parallel sections| single          | +                                  |
1591   // | parallel sections| parallel for    | *                                  |
1592   // | parallel sections|parallel for simd| *                                  |
1593   // | parallel sections|parallel sections| *                                  |
1594   // | parallel sections| task            | *                                  |
1595   // | parallel sections| taskyield       | *                                  |
1596   // | parallel sections| barrier         | +                                  |
1597   // | parallel sections| taskwait        | *                                  |
1598   // | parallel sections| taskgroup       | *                                  |
1599   // | parallel sections| flush           | *                                  |
1600   // | parallel sections| ordered         | +                                  |
1601   // | parallel sections| atomic          | *                                  |
1602   // | parallel sections| target          | *                                  |
1603   // | parallel sections| teams           | +                                  |
1604   // +------------------+-----------------+------------------------------------+
1605   // | task             | parallel        | *                                  |
1606   // | task             | for             | +                                  |
1607   // | task             | for simd        | +                                  |
1608   // | task             | master          | +                                  |
1609   // | task             | critical        | *                                  |
1610   // | task             | simd            | *                                  |
1611   // | task             | sections        | +                                  |
1612   // | task             | section         | +                                  |
1613   // | task             | single          | +                                  |
1614   // | task             | parallel for    | *                                  |
1615   // | task             |parallel for simd| *                                  |
1616   // | task             |parallel sections| *                                  |
1617   // | task             | task            | *                                  |
1618   // | task             | taskyield       | *                                  |
1619   // | task             | barrier         | +                                  |
1620   // | task             | taskwait        | *                                  |
1621   // | task             | taskgroup       | *                                  |
1622   // | task             | flush           | *                                  |
1623   // | task             | ordered         | +                                  |
1624   // | task             | atomic          | *                                  |
1625   // | task             | target          | *                                  |
1626   // | task             | teams           | +                                  |
1627   // +------------------+-----------------+------------------------------------+
1628   // | ordered          | parallel        | *                                  |
1629   // | ordered          | for             | +                                  |
1630   // | ordered          | for simd        | +                                  |
1631   // | ordered          | master          | *                                  |
1632   // | ordered          | critical        | *                                  |
1633   // | ordered          | simd            | *                                  |
1634   // | ordered          | sections        | +                                  |
1635   // | ordered          | section         | +                                  |
1636   // | ordered          | single          | +                                  |
1637   // | ordered          | parallel for    | *                                  |
1638   // | ordered          |parallel for simd| *                                  |
1639   // | ordered          |parallel sections| *                                  |
1640   // | ordered          | task            | *                                  |
1641   // | ordered          | taskyield       | *                                  |
1642   // | ordered          | barrier         | +                                  |
1643   // | ordered          | taskwait        | *                                  |
1644   // | ordered          | taskgroup       | *                                  |
1645   // | ordered          | flush           | *                                  |
1646   // | ordered          | ordered         | +                                  |
1647   // | ordered          | atomic          | *                                  |
1648   // | ordered          | target          | *                                  |
1649   // | ordered          | teams           | +                                  |
1650   // +------------------+-----------------+------------------------------------+
1651   // | atomic           | parallel        |                                    |
1652   // | atomic           | for             |                                    |
1653   // | atomic           | for simd        |                                    |
1654   // | atomic           | master          |                                    |
1655   // | atomic           | critical        |                                    |
1656   // | atomic           | simd            |                                    |
1657   // | atomic           | sections        |                                    |
1658   // | atomic           | section         |                                    |
1659   // | atomic           | single          |                                    |
1660   // | atomic           | parallel for    |                                    |
1661   // | atomic           |parallel for simd|                                    |
1662   // | atomic           |parallel sections|                                    |
1663   // | atomic           | task            |                                    |
1664   // | atomic           | taskyield       |                                    |
1665   // | atomic           | barrier         |                                    |
1666   // | atomic           | taskwait        |                                    |
1667   // | atomic           | taskgroup       |                                    |
1668   // | atomic           | flush           |                                    |
1669   // | atomic           | ordered         |                                    |
1670   // | atomic           | atomic          |                                    |
1671   // | atomic           | target          |                                    |
1672   // | atomic           | teams           |                                    |
1673   // +------------------+-----------------+------------------------------------+
1674   // | target           | parallel        | *                                  |
1675   // | target           | for             | *                                  |
1676   // | target           | for simd        | *                                  |
1677   // | target           | master          | *                                  |
1678   // | target           | critical        | *                                  |
1679   // | target           | simd            | *                                  |
1680   // | target           | sections        | *                                  |
1681   // | target           | section         | *                                  |
1682   // | target           | single          | *                                  |
1683   // | target           | parallel for    | *                                  |
1684   // | target           |parallel for simd| *                                  |
1685   // | target           |parallel sections| *                                  |
1686   // | target           | task            | *                                  |
1687   // | target           | taskyield       | *                                  |
1688   // | target           | barrier         | *                                  |
1689   // | target           | taskwait        | *                                  |
1690   // | target           | taskgroup       | *                                  |
1691   // | target           | flush           | *                                  |
1692   // | target           | ordered         | *                                  |
1693   // | target           | atomic          | *                                  |
1694   // | target           | target          | *                                  |
1695   // | target           | teams           | *                                  |
1696   // +------------------+-----------------+------------------------------------+
1697   // | teams            | parallel        | *                                  |
1698   // | teams            | for             | +                                  |
1699   // | teams            | for simd        | +                                  |
1700   // | teams            | master          | +                                  |
1701   // | teams            | critical        | +                                  |
1702   // | teams            | simd            | +                                  |
1703   // | teams            | sections        | +                                  |
1704   // | teams            | section         | +                                  |
1705   // | teams            | single          | +                                  |
1706   // | teams            | parallel for    | *                                  |
1707   // | teams            |parallel for simd| *                                  |
1708   // | teams            |parallel sections| *                                  |
1709   // | teams            | task            | +                                  |
1710   // | teams            | taskyield       | +                                  |
1711   // | teams            | barrier         | +                                  |
1712   // | teams            | taskwait        | +                                  |
1713   // | teams            | taskgroup        | +                                  |
1714   // | teams            | flush           | +                                  |
1715   // | teams            | ordered         | +                                  |
1716   // | teams            | atomic          | +                                  |
1717   // | teams            | target          | +                                  |
1718   // | teams            | teams           | +                                  |
1719   // +------------------+-----------------+------------------------------------+
1720   if (Stack->getCurScope()) {
1721     auto ParentRegion = Stack->getParentDirective();
1722     bool NestingProhibited = false;
1723     bool CloseNesting = true;
1724     enum {
1725       NoRecommend,
1726       ShouldBeInParallelRegion,
1727       ShouldBeInOrderedRegion,
1728       ShouldBeInTargetRegion
1729     } Recommend = NoRecommend;
1730     if (isOpenMPSimdDirective(ParentRegion)) {
1731       // OpenMP [2.16, Nesting of Regions]
1732       // OpenMP constructs may not be nested inside a simd region.
1733       SemaRef.Diag(StartLoc, diag::err_omp_prohibited_region_simd);
1734       return true;
1735     }
1736     if (ParentRegion == OMPD_atomic) {
1737       // OpenMP [2.16, Nesting of Regions]
1738       // OpenMP constructs may not be nested inside an atomic region.
1739       SemaRef.Diag(StartLoc, diag::err_omp_prohibited_region_atomic);
1740       return true;
1741     }
1742     if (CurrentRegion == OMPD_section) {
1743       // OpenMP [2.7.2, sections Construct, Restrictions]
1744       // Orphaned section directives are prohibited. That is, the section
1745       // directives must appear within the sections construct and must not be
1746       // encountered elsewhere in the sections region.
1747       if (ParentRegion != OMPD_sections &&
1748           ParentRegion != OMPD_parallel_sections) {
1749         SemaRef.Diag(StartLoc, diag::err_omp_orphaned_section_directive)
1750             << (ParentRegion != OMPD_unknown)
1751             << getOpenMPDirectiveName(ParentRegion);
1752         return true;
1753       }
1754       return false;
1755     }
1756     // Allow some constructs to be orphaned (they could be used in functions,
1757     // called from OpenMP regions with the required preconditions).
1758     if (ParentRegion == OMPD_unknown)
1759       return false;
1760     if (CurrentRegion == OMPD_master) {
1761       // OpenMP [2.16, Nesting of Regions]
1762       // A master region may not be closely nested inside a worksharing,
1763       // atomic, or explicit task region.
1764       NestingProhibited = isOpenMPWorksharingDirective(ParentRegion) ||
1765                           ParentRegion == OMPD_task;
1766     } else if (CurrentRegion == OMPD_critical && CurrentName.getName()) {
1767       // OpenMP [2.16, Nesting of Regions]
1768       // A critical region may not be nested (closely or otherwise) inside a
1769       // critical region with the same name. Note that this restriction is not
1770       // sufficient to prevent deadlock.
1771       SourceLocation PreviousCriticalLoc;
1772       bool DeadLock =
1773           Stack->hasDirective([CurrentName, &PreviousCriticalLoc](
1774                                   OpenMPDirectiveKind K,
1775                                   const DeclarationNameInfo &DNI,
1776                                   SourceLocation Loc)
1777                                   ->bool {
1778                                 if (K == OMPD_critical &&
1779                                     DNI.getName() == CurrentName.getName()) {
1780                                   PreviousCriticalLoc = Loc;
1781                                   return true;
1782                                 } else
1783                                   return false;
1784                               },
1785                               false /* skip top directive */);
1786       if (DeadLock) {
1787         SemaRef.Diag(StartLoc,
1788                      diag::err_omp_prohibited_region_critical_same_name)
1789             << CurrentName.getName();
1790         if (PreviousCriticalLoc.isValid())
1791           SemaRef.Diag(PreviousCriticalLoc,
1792                        diag::note_omp_previous_critical_region);
1793         return true;
1794       }
1795     } else if (CurrentRegion == OMPD_barrier) {
1796       // OpenMP [2.16, Nesting of Regions]
1797       // A barrier region may not be closely nested inside a worksharing,
1798       // explicit task, critical, ordered, atomic, or master region.
1799       NestingProhibited =
1800           isOpenMPWorksharingDirective(ParentRegion) ||
1801           ParentRegion == OMPD_task || ParentRegion == OMPD_master ||
1802           ParentRegion == OMPD_critical || ParentRegion == OMPD_ordered;
1803     } else if (isOpenMPWorksharingDirective(CurrentRegion) &&
1804                !isOpenMPParallelDirective(CurrentRegion)) {
1805       // OpenMP [2.16, Nesting of Regions]
1806       // A worksharing region may not be closely nested inside a worksharing,
1807       // explicit task, critical, ordered, atomic, or master region.
1808       NestingProhibited =
1809           isOpenMPWorksharingDirective(ParentRegion) ||
1810           ParentRegion == OMPD_task || ParentRegion == OMPD_master ||
1811           ParentRegion == OMPD_critical || ParentRegion == OMPD_ordered;
1812       Recommend = ShouldBeInParallelRegion;
1813     } else if (CurrentRegion == OMPD_ordered) {
1814       // OpenMP [2.16, Nesting of Regions]
1815       // An ordered region may not be closely nested inside a critical,
1816       // atomic, or explicit task region.
1817       // An ordered region must be closely nested inside a loop region (or
1818       // parallel loop region) with an ordered clause.
1819       NestingProhibited = ParentRegion == OMPD_critical ||
1820                           ParentRegion == OMPD_task ||
1821                           !Stack->isParentOrderedRegion();
1822       Recommend = ShouldBeInOrderedRegion;
1823     } else if (isOpenMPTeamsDirective(CurrentRegion)) {
1824       // OpenMP [2.16, Nesting of Regions]
1825       // If specified, a teams construct must be contained within a target
1826       // construct.
1827       NestingProhibited = ParentRegion != OMPD_target;
1828       Recommend = ShouldBeInTargetRegion;
1829       Stack->setParentTeamsRegionLoc(Stack->getConstructLoc());
1830     }
1831     if (!NestingProhibited && isOpenMPTeamsDirective(ParentRegion)) {
1832       // OpenMP [2.16, Nesting of Regions]
1833       // distribute, parallel, parallel sections, parallel workshare, and the
1834       // parallel loop and parallel loop SIMD constructs are the only OpenMP
1835       // constructs that can be closely nested in the teams region.
1836       // TODO: add distribute directive.
1837       NestingProhibited = !isOpenMPParallelDirective(CurrentRegion);
1838       Recommend = ShouldBeInParallelRegion;
1839     }
1840     if (NestingProhibited) {
1841       SemaRef.Diag(StartLoc, diag::err_omp_prohibited_region)
1842           << CloseNesting << getOpenMPDirectiveName(ParentRegion) << Recommend
1843           << getOpenMPDirectiveName(CurrentRegion);
1844       return true;
1845     }
1846   }
1847   return false;
1848 }
1849 
1850 StmtResult Sema::ActOnOpenMPExecutableDirective(OpenMPDirectiveKind Kind,
1851                                                 const DeclarationNameInfo &DirName,
1852                                                 ArrayRef<OMPClause *> Clauses,
1853                                                 Stmt *AStmt,
1854                                                 SourceLocation StartLoc,
1855                                                 SourceLocation EndLoc) {
1856   StmtResult Res = StmtError();
1857   if (CheckNestingOfRegions(*this, DSAStack, Kind, DirName, StartLoc))
1858     return StmtError();
1859 
1860   llvm::SmallVector<OMPClause *, 8> ClausesWithImplicit;
1861   llvm::DenseMap<VarDecl *, Expr *> VarsWithInheritedDSA;
1862   bool ErrorFound = false;
1863   ClausesWithImplicit.append(Clauses.begin(), Clauses.end());
1864   if (AStmt) {
1865     assert(isa<CapturedStmt>(AStmt) && "Captured statement expected");
1866 
1867     // Check default data sharing attributes for referenced variables.
1868     DSAAttrChecker DSAChecker(DSAStack, *this, cast<CapturedStmt>(AStmt));
1869     DSAChecker.Visit(cast<CapturedStmt>(AStmt)->getCapturedStmt());
1870     if (DSAChecker.isErrorFound())
1871       return StmtError();
1872     // Generate list of implicitly defined firstprivate variables.
1873     VarsWithInheritedDSA = DSAChecker.getVarsWithInheritedDSA();
1874 
1875     if (!DSAChecker.getImplicitFirstprivate().empty()) {
1876       if (OMPClause *Implicit = ActOnOpenMPFirstprivateClause(
1877               DSAChecker.getImplicitFirstprivate(), SourceLocation(),
1878               SourceLocation(), SourceLocation())) {
1879         ClausesWithImplicit.push_back(Implicit);
1880         ErrorFound = cast<OMPFirstprivateClause>(Implicit)->varlist_size() !=
1881                      DSAChecker.getImplicitFirstprivate().size();
1882       } else
1883         ErrorFound = true;
1884     }
1885   }
1886 
1887   switch (Kind) {
1888   case OMPD_parallel:
1889     Res = ActOnOpenMPParallelDirective(ClausesWithImplicit, AStmt, StartLoc,
1890                                        EndLoc);
1891     break;
1892   case OMPD_simd:
1893     Res = ActOnOpenMPSimdDirective(ClausesWithImplicit, AStmt, StartLoc, EndLoc,
1894                                    VarsWithInheritedDSA);
1895     break;
1896   case OMPD_for:
1897     Res = ActOnOpenMPForDirective(ClausesWithImplicit, AStmt, StartLoc, EndLoc,
1898                                   VarsWithInheritedDSA);
1899     break;
1900   case OMPD_for_simd:
1901     Res = ActOnOpenMPForSimdDirective(ClausesWithImplicit, AStmt, StartLoc,
1902                                       EndLoc, VarsWithInheritedDSA);
1903     break;
1904   case OMPD_sections:
1905     Res = ActOnOpenMPSectionsDirective(ClausesWithImplicit, AStmt, StartLoc,
1906                                        EndLoc);
1907     break;
1908   case OMPD_section:
1909     assert(ClausesWithImplicit.empty() &&
1910            "No clauses are allowed for 'omp section' directive");
1911     Res = ActOnOpenMPSectionDirective(AStmt, StartLoc, EndLoc);
1912     break;
1913   case OMPD_single:
1914     Res = ActOnOpenMPSingleDirective(ClausesWithImplicit, AStmt, StartLoc,
1915                                      EndLoc);
1916     break;
1917   case OMPD_master:
1918     assert(ClausesWithImplicit.empty() &&
1919            "No clauses are allowed for 'omp master' directive");
1920     Res = ActOnOpenMPMasterDirective(AStmt, StartLoc, EndLoc);
1921     break;
1922   case OMPD_critical:
1923     assert(ClausesWithImplicit.empty() &&
1924            "No clauses are allowed for 'omp critical' directive");
1925     Res = ActOnOpenMPCriticalDirective(DirName, AStmt, StartLoc, EndLoc);
1926     break;
1927   case OMPD_parallel_for:
1928     Res = ActOnOpenMPParallelForDirective(ClausesWithImplicit, AStmt, StartLoc,
1929                                           EndLoc, VarsWithInheritedDSA);
1930     break;
1931   case OMPD_parallel_for_simd:
1932     Res = ActOnOpenMPParallelForSimdDirective(
1933         ClausesWithImplicit, AStmt, StartLoc, EndLoc, VarsWithInheritedDSA);
1934     break;
1935   case OMPD_parallel_sections:
1936     Res = ActOnOpenMPParallelSectionsDirective(ClausesWithImplicit, AStmt,
1937                                                StartLoc, EndLoc);
1938     break;
1939   case OMPD_task:
1940     Res =
1941         ActOnOpenMPTaskDirective(ClausesWithImplicit, AStmt, StartLoc, EndLoc);
1942     break;
1943   case OMPD_taskyield:
1944     assert(ClausesWithImplicit.empty() &&
1945            "No clauses are allowed for 'omp taskyield' directive");
1946     assert(AStmt == nullptr &&
1947            "No associated statement allowed for 'omp taskyield' directive");
1948     Res = ActOnOpenMPTaskyieldDirective(StartLoc, EndLoc);
1949     break;
1950   case OMPD_barrier:
1951     assert(ClausesWithImplicit.empty() &&
1952            "No clauses are allowed for 'omp barrier' directive");
1953     assert(AStmt == nullptr &&
1954            "No associated statement allowed for 'omp barrier' directive");
1955     Res = ActOnOpenMPBarrierDirective(StartLoc, EndLoc);
1956     break;
1957   case OMPD_taskwait:
1958     assert(ClausesWithImplicit.empty() &&
1959            "No clauses are allowed for 'omp taskwait' directive");
1960     assert(AStmt == nullptr &&
1961            "No associated statement allowed for 'omp taskwait' directive");
1962     Res = ActOnOpenMPTaskwaitDirective(StartLoc, EndLoc);
1963     break;
1964   case OMPD_taskgroup:
1965     assert(ClausesWithImplicit.empty() &&
1966            "No clauses are allowed for 'omp taskgroup' directive");
1967     Res = ActOnOpenMPTaskgroupDirective(AStmt, StartLoc, EndLoc);
1968     break;
1969   case OMPD_flush:
1970     assert(AStmt == nullptr &&
1971            "No associated statement allowed for 'omp flush' directive");
1972     Res = ActOnOpenMPFlushDirective(ClausesWithImplicit, StartLoc, EndLoc);
1973     break;
1974   case OMPD_ordered:
1975     assert(ClausesWithImplicit.empty() &&
1976            "No clauses are allowed for 'omp ordered' directive");
1977     Res = ActOnOpenMPOrderedDirective(AStmt, StartLoc, EndLoc);
1978     break;
1979   case OMPD_atomic:
1980     Res = ActOnOpenMPAtomicDirective(ClausesWithImplicit, AStmt, StartLoc,
1981                                      EndLoc);
1982     break;
1983   case OMPD_teams:
1984     Res =
1985         ActOnOpenMPTeamsDirective(ClausesWithImplicit, AStmt, StartLoc, EndLoc);
1986     break;
1987   case OMPD_target:
1988     Res = ActOnOpenMPTargetDirective(ClausesWithImplicit, AStmt, StartLoc,
1989                                      EndLoc);
1990     break;
1991   case OMPD_threadprivate:
1992     llvm_unreachable("OpenMP Directive is not allowed");
1993   case OMPD_unknown:
1994     llvm_unreachable("Unknown OpenMP directive");
1995   }
1996 
1997   for (auto P : VarsWithInheritedDSA) {
1998     Diag(P.second->getExprLoc(), diag::err_omp_no_dsa_for_variable)
1999         << P.first << P.second->getSourceRange();
2000   }
2001   if (!VarsWithInheritedDSA.empty())
2002     return StmtError();
2003 
2004   if (ErrorFound)
2005     return StmtError();
2006   return Res;
2007 }
2008 
2009 StmtResult Sema::ActOnOpenMPParallelDirective(ArrayRef<OMPClause *> Clauses,
2010                                               Stmt *AStmt,
2011                                               SourceLocation StartLoc,
2012                                               SourceLocation EndLoc) {
2013   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
2014   CapturedStmt *CS = cast<CapturedStmt>(AStmt);
2015   // 1.2.2 OpenMP Language Terminology
2016   // Structured block - An executable statement with a single entry at the
2017   // top and a single exit at the bottom.
2018   // The point of exit cannot be a branch out of the structured block.
2019   // longjmp() and throw() must not violate the entry/exit criteria.
2020   CS->getCapturedDecl()->setNothrow();
2021 
2022   getCurFunction()->setHasBranchProtectedScope();
2023 
2024   return OMPParallelDirective::Create(Context, StartLoc, EndLoc, Clauses,
2025                                       AStmt);
2026 }
2027 
2028 namespace {
2029 /// \brief Helper class for checking canonical form of the OpenMP loops and
2030 /// extracting iteration space of each loop in the loop nest, that will be used
2031 /// for IR generation.
2032 class OpenMPIterationSpaceChecker {
2033   /// \brief Reference to Sema.
2034   Sema &SemaRef;
2035   /// \brief A location for diagnostics (when there is no some better location).
2036   SourceLocation DefaultLoc;
2037   /// \brief A location for diagnostics (when increment is not compatible).
2038   SourceLocation ConditionLoc;
2039   /// \brief A source location for referring to loop init later.
2040   SourceRange InitSrcRange;
2041   /// \brief A source location for referring to condition later.
2042   SourceRange ConditionSrcRange;
2043   /// \brief A source location for referring to increment later.
2044   SourceRange IncrementSrcRange;
2045   /// \brief Loop variable.
2046   VarDecl *Var;
2047   /// \brief Reference to loop variable.
2048   DeclRefExpr *VarRef;
2049   /// \brief Lower bound (initializer for the var).
2050   Expr *LB;
2051   /// \brief Upper bound.
2052   Expr *UB;
2053   /// \brief Loop step (increment).
2054   Expr *Step;
2055   /// \brief This flag is true when condition is one of:
2056   ///   Var <  UB
2057   ///   Var <= UB
2058   ///   UB  >  Var
2059   ///   UB  >= Var
2060   bool TestIsLessOp;
2061   /// \brief This flag is true when condition is strict ( < or > ).
2062   bool TestIsStrictOp;
2063   /// \brief This flag is true when step is subtracted on each iteration.
2064   bool SubtractStep;
2065 
2066 public:
2067   OpenMPIterationSpaceChecker(Sema &SemaRef, SourceLocation DefaultLoc)
2068       : SemaRef(SemaRef), DefaultLoc(DefaultLoc), ConditionLoc(DefaultLoc),
2069         InitSrcRange(SourceRange()), ConditionSrcRange(SourceRange()),
2070         IncrementSrcRange(SourceRange()), Var(nullptr), VarRef(nullptr),
2071         LB(nullptr), UB(nullptr), Step(nullptr), TestIsLessOp(false),
2072         TestIsStrictOp(false), SubtractStep(false) {}
2073   /// \brief Check init-expr for canonical loop form and save loop counter
2074   /// variable - #Var and its initialization value - #LB.
2075   bool CheckInit(Stmt *S, bool EmitDiags = true);
2076   /// \brief Check test-expr for canonical form, save upper-bound (#UB), flags
2077   /// for less/greater and for strict/non-strict comparison.
2078   bool CheckCond(Expr *S);
2079   /// \brief Check incr-expr for canonical loop form and return true if it
2080   /// does not conform, otherwise save loop step (#Step).
2081   bool CheckInc(Expr *S);
2082   /// \brief Return the loop counter variable.
2083   VarDecl *GetLoopVar() const { return Var; }
2084   /// \brief Return the reference expression to loop counter variable.
2085   DeclRefExpr *GetLoopVarRefExpr() const { return VarRef; }
2086   /// \brief Source range of the loop init.
2087   SourceRange GetInitSrcRange() const { return InitSrcRange; }
2088   /// \brief Source range of the loop condition.
2089   SourceRange GetConditionSrcRange() const { return ConditionSrcRange; }
2090   /// \brief Source range of the loop increment.
2091   SourceRange GetIncrementSrcRange() const { return IncrementSrcRange; }
2092   /// \brief True if the step should be subtracted.
2093   bool ShouldSubtractStep() const { return SubtractStep; }
2094   /// \brief Build the expression to calculate the number of iterations.
2095   Expr *BuildNumIterations(Scope *S, const bool LimitedType) const;
2096   /// \brief Build the precondition expression for the loops.
2097   Expr *BuildPreCond(Scope *S, Expr *Cond) const;
2098   /// \brief Build reference expression to the counter be used for codegen.
2099   Expr *BuildCounterVar() const;
2100   /// \brief Build initization of the counter be used for codegen.
2101   Expr *BuildCounterInit() const;
2102   /// \brief Build step of the counter be used for codegen.
2103   Expr *BuildCounterStep() const;
2104   /// \brief Return true if any expression is dependent.
2105   bool Dependent() const;
2106 
2107 private:
2108   /// \brief Check the right-hand side of an assignment in the increment
2109   /// expression.
2110   bool CheckIncRHS(Expr *RHS);
2111   /// \brief Helper to set loop counter variable and its initializer.
2112   bool SetVarAndLB(VarDecl *NewVar, DeclRefExpr *NewVarRefExpr, Expr *NewLB);
2113   /// \brief Helper to set upper bound.
2114   bool SetUB(Expr *NewUB, bool LessOp, bool StrictOp, const SourceRange &SR,
2115              const SourceLocation &SL);
2116   /// \brief Helper to set loop increment.
2117   bool SetStep(Expr *NewStep, bool Subtract);
2118 };
2119 
2120 bool OpenMPIterationSpaceChecker::Dependent() const {
2121   if (!Var) {
2122     assert(!LB && !UB && !Step);
2123     return false;
2124   }
2125   return Var->getType()->isDependentType() || (LB && LB->isValueDependent()) ||
2126          (UB && UB->isValueDependent()) || (Step && Step->isValueDependent());
2127 }
2128 
2129 bool OpenMPIterationSpaceChecker::SetVarAndLB(VarDecl *NewVar,
2130                                               DeclRefExpr *NewVarRefExpr,
2131                                               Expr *NewLB) {
2132   // State consistency checking to ensure correct usage.
2133   assert(Var == nullptr && LB == nullptr && VarRef == nullptr &&
2134          UB == nullptr && Step == nullptr && !TestIsLessOp && !TestIsStrictOp);
2135   if (!NewVar || !NewLB)
2136     return true;
2137   Var = NewVar;
2138   VarRef = NewVarRefExpr;
2139   LB = NewLB;
2140   return false;
2141 }
2142 
2143 bool OpenMPIterationSpaceChecker::SetUB(Expr *NewUB, bool LessOp, bool StrictOp,
2144                                         const SourceRange &SR,
2145                                         const SourceLocation &SL) {
2146   // State consistency checking to ensure correct usage.
2147   assert(Var != nullptr && LB != nullptr && UB == nullptr && Step == nullptr &&
2148          !TestIsLessOp && !TestIsStrictOp);
2149   if (!NewUB)
2150     return true;
2151   UB = NewUB;
2152   TestIsLessOp = LessOp;
2153   TestIsStrictOp = StrictOp;
2154   ConditionSrcRange = SR;
2155   ConditionLoc = SL;
2156   return false;
2157 }
2158 
2159 bool OpenMPIterationSpaceChecker::SetStep(Expr *NewStep, bool Subtract) {
2160   // State consistency checking to ensure correct usage.
2161   assert(Var != nullptr && LB != nullptr && Step == nullptr);
2162   if (!NewStep)
2163     return true;
2164   if (!NewStep->isValueDependent()) {
2165     // Check that the step is integer expression.
2166     SourceLocation StepLoc = NewStep->getLocStart();
2167     ExprResult Val =
2168         SemaRef.PerformOpenMPImplicitIntegerConversion(StepLoc, NewStep);
2169     if (Val.isInvalid())
2170       return true;
2171     NewStep = Val.get();
2172 
2173     // OpenMP [2.6, Canonical Loop Form, Restrictions]
2174     //  If test-expr is of form var relational-op b and relational-op is < or
2175     //  <= then incr-expr must cause var to increase on each iteration of the
2176     //  loop. If test-expr is of form var relational-op b and relational-op is
2177     //  > or >= then incr-expr must cause var to decrease on each iteration of
2178     //  the loop.
2179     //  If test-expr is of form b relational-op var and relational-op is < or
2180     //  <= then incr-expr must cause var to decrease on each iteration of the
2181     //  loop. If test-expr is of form b relational-op var and relational-op is
2182     //  > or >= then incr-expr must cause var to increase on each iteration of
2183     //  the loop.
2184     llvm::APSInt Result;
2185     bool IsConstant = NewStep->isIntegerConstantExpr(Result, SemaRef.Context);
2186     bool IsUnsigned = !NewStep->getType()->hasSignedIntegerRepresentation();
2187     bool IsConstNeg =
2188         IsConstant && Result.isSigned() && (Subtract != Result.isNegative());
2189     bool IsConstPos =
2190         IsConstant && Result.isSigned() && (Subtract == Result.isNegative());
2191     bool IsConstZero = IsConstant && !Result.getBoolValue();
2192     if (UB && (IsConstZero ||
2193                (TestIsLessOp ? (IsConstNeg || (IsUnsigned && Subtract))
2194                              : (IsConstPos || (IsUnsigned && !Subtract))))) {
2195       SemaRef.Diag(NewStep->getExprLoc(),
2196                    diag::err_omp_loop_incr_not_compatible)
2197           << Var << TestIsLessOp << NewStep->getSourceRange();
2198       SemaRef.Diag(ConditionLoc,
2199                    diag::note_omp_loop_cond_requres_compatible_incr)
2200           << TestIsLessOp << ConditionSrcRange;
2201       return true;
2202     }
2203     if (TestIsLessOp == Subtract) {
2204       NewStep = SemaRef.CreateBuiltinUnaryOp(NewStep->getExprLoc(), UO_Minus,
2205                                              NewStep).get();
2206       Subtract = !Subtract;
2207     }
2208   }
2209 
2210   Step = NewStep;
2211   SubtractStep = Subtract;
2212   return false;
2213 }
2214 
2215 bool OpenMPIterationSpaceChecker::CheckInit(Stmt *S, bool EmitDiags) {
2216   // Check init-expr for canonical loop form and save loop counter
2217   // variable - #Var and its initialization value - #LB.
2218   // OpenMP [2.6] Canonical loop form. init-expr may be one of the following:
2219   //   var = lb
2220   //   integer-type var = lb
2221   //   random-access-iterator-type var = lb
2222   //   pointer-type var = lb
2223   //
2224   if (!S) {
2225     if (EmitDiags) {
2226       SemaRef.Diag(DefaultLoc, diag::err_omp_loop_not_canonical_init);
2227     }
2228     return true;
2229   }
2230   InitSrcRange = S->getSourceRange();
2231   if (Expr *E = dyn_cast<Expr>(S))
2232     S = E->IgnoreParens();
2233   if (auto BO = dyn_cast<BinaryOperator>(S)) {
2234     if (BO->getOpcode() == BO_Assign)
2235       if (auto DRE = dyn_cast<DeclRefExpr>(BO->getLHS()->IgnoreParens()))
2236         return SetVarAndLB(dyn_cast<VarDecl>(DRE->getDecl()), DRE,
2237                            BO->getRHS());
2238   } else if (auto DS = dyn_cast<DeclStmt>(S)) {
2239     if (DS->isSingleDecl()) {
2240       if (auto Var = dyn_cast_or_null<VarDecl>(DS->getSingleDecl())) {
2241         if (Var->hasInit()) {
2242           // Accept non-canonical init form here but emit ext. warning.
2243           if (Var->getInitStyle() != VarDecl::CInit && EmitDiags)
2244             SemaRef.Diag(S->getLocStart(),
2245                          diag::ext_omp_loop_not_canonical_init)
2246                 << S->getSourceRange();
2247           return SetVarAndLB(Var, nullptr, Var->getInit());
2248         }
2249       }
2250     }
2251   } else if (auto CE = dyn_cast<CXXOperatorCallExpr>(S))
2252     if (CE->getOperator() == OO_Equal)
2253       if (auto DRE = dyn_cast<DeclRefExpr>(CE->getArg(0)))
2254         return SetVarAndLB(dyn_cast<VarDecl>(DRE->getDecl()), DRE,
2255                            CE->getArg(1));
2256 
2257   if (EmitDiags) {
2258     SemaRef.Diag(S->getLocStart(), diag::err_omp_loop_not_canonical_init)
2259         << S->getSourceRange();
2260   }
2261   return true;
2262 }
2263 
2264 /// \brief Ignore parenthesizes, implicit casts, copy constructor and return the
2265 /// variable (which may be the loop variable) if possible.
2266 static const VarDecl *GetInitVarDecl(const Expr *E) {
2267   if (!E)
2268     return nullptr;
2269   E = E->IgnoreParenImpCasts();
2270   if (auto *CE = dyn_cast_or_null<CXXConstructExpr>(E))
2271     if (const CXXConstructorDecl *Ctor = CE->getConstructor())
2272       if (Ctor->isCopyConstructor() && CE->getNumArgs() == 1 &&
2273           CE->getArg(0) != nullptr)
2274         E = CE->getArg(0)->IgnoreParenImpCasts();
2275   auto DRE = dyn_cast_or_null<DeclRefExpr>(E);
2276   if (!DRE)
2277     return nullptr;
2278   return dyn_cast<VarDecl>(DRE->getDecl());
2279 }
2280 
2281 bool OpenMPIterationSpaceChecker::CheckCond(Expr *S) {
2282   // Check test-expr for canonical form, save upper-bound UB, flags for
2283   // less/greater and for strict/non-strict comparison.
2284   // OpenMP [2.6] Canonical loop form. Test-expr may be one of the following:
2285   //   var relational-op b
2286   //   b relational-op var
2287   //
2288   if (!S) {
2289     SemaRef.Diag(DefaultLoc, diag::err_omp_loop_not_canonical_cond) << Var;
2290     return true;
2291   }
2292   S = S->IgnoreParenImpCasts();
2293   SourceLocation CondLoc = S->getLocStart();
2294   if (auto BO = dyn_cast<BinaryOperator>(S)) {
2295     if (BO->isRelationalOp()) {
2296       if (GetInitVarDecl(BO->getLHS()) == Var)
2297         return SetUB(BO->getRHS(),
2298                      (BO->getOpcode() == BO_LT || BO->getOpcode() == BO_LE),
2299                      (BO->getOpcode() == BO_LT || BO->getOpcode() == BO_GT),
2300                      BO->getSourceRange(), BO->getOperatorLoc());
2301       if (GetInitVarDecl(BO->getRHS()) == Var)
2302         return SetUB(BO->getLHS(),
2303                      (BO->getOpcode() == BO_GT || BO->getOpcode() == BO_GE),
2304                      (BO->getOpcode() == BO_LT || BO->getOpcode() == BO_GT),
2305                      BO->getSourceRange(), BO->getOperatorLoc());
2306     }
2307   } else if (auto CE = dyn_cast<CXXOperatorCallExpr>(S)) {
2308     if (CE->getNumArgs() == 2) {
2309       auto Op = CE->getOperator();
2310       switch (Op) {
2311       case OO_Greater:
2312       case OO_GreaterEqual:
2313       case OO_Less:
2314       case OO_LessEqual:
2315         if (GetInitVarDecl(CE->getArg(0)) == Var)
2316           return SetUB(CE->getArg(1), Op == OO_Less || Op == OO_LessEqual,
2317                        Op == OO_Less || Op == OO_Greater, CE->getSourceRange(),
2318                        CE->getOperatorLoc());
2319         if (GetInitVarDecl(CE->getArg(1)) == Var)
2320           return SetUB(CE->getArg(0), Op == OO_Greater || Op == OO_GreaterEqual,
2321                        Op == OO_Less || Op == OO_Greater, CE->getSourceRange(),
2322                        CE->getOperatorLoc());
2323         break;
2324       default:
2325         break;
2326       }
2327     }
2328   }
2329   SemaRef.Diag(CondLoc, diag::err_omp_loop_not_canonical_cond)
2330       << S->getSourceRange() << Var;
2331   return true;
2332 }
2333 
2334 bool OpenMPIterationSpaceChecker::CheckIncRHS(Expr *RHS) {
2335   // RHS of canonical loop form increment can be:
2336   //   var + incr
2337   //   incr + var
2338   //   var - incr
2339   //
2340   RHS = RHS->IgnoreParenImpCasts();
2341   if (auto BO = dyn_cast<BinaryOperator>(RHS)) {
2342     if (BO->isAdditiveOp()) {
2343       bool IsAdd = BO->getOpcode() == BO_Add;
2344       if (GetInitVarDecl(BO->getLHS()) == Var)
2345         return SetStep(BO->getRHS(), !IsAdd);
2346       if (IsAdd && GetInitVarDecl(BO->getRHS()) == Var)
2347         return SetStep(BO->getLHS(), false);
2348     }
2349   } else if (auto CE = dyn_cast<CXXOperatorCallExpr>(RHS)) {
2350     bool IsAdd = CE->getOperator() == OO_Plus;
2351     if ((IsAdd || CE->getOperator() == OO_Minus) && CE->getNumArgs() == 2) {
2352       if (GetInitVarDecl(CE->getArg(0)) == Var)
2353         return SetStep(CE->getArg(1), !IsAdd);
2354       if (IsAdd && GetInitVarDecl(CE->getArg(1)) == Var)
2355         return SetStep(CE->getArg(0), false);
2356     }
2357   }
2358   SemaRef.Diag(RHS->getLocStart(), diag::err_omp_loop_not_canonical_incr)
2359       << RHS->getSourceRange() << Var;
2360   return true;
2361 }
2362 
2363 bool OpenMPIterationSpaceChecker::CheckInc(Expr *S) {
2364   // Check incr-expr for canonical loop form and return true if it
2365   // does not conform.
2366   // OpenMP [2.6] Canonical loop form. Test-expr may be one of the following:
2367   //   ++var
2368   //   var++
2369   //   --var
2370   //   var--
2371   //   var += incr
2372   //   var -= incr
2373   //   var = var + incr
2374   //   var = incr + var
2375   //   var = var - incr
2376   //
2377   if (!S) {
2378     SemaRef.Diag(DefaultLoc, diag::err_omp_loop_not_canonical_incr) << Var;
2379     return true;
2380   }
2381   IncrementSrcRange = S->getSourceRange();
2382   S = S->IgnoreParens();
2383   if (auto UO = dyn_cast<UnaryOperator>(S)) {
2384     if (UO->isIncrementDecrementOp() && GetInitVarDecl(UO->getSubExpr()) == Var)
2385       return SetStep(
2386           SemaRef.ActOnIntegerConstant(UO->getLocStart(),
2387                                        (UO->isDecrementOp() ? -1 : 1)).get(),
2388           false);
2389   } else if (auto BO = dyn_cast<BinaryOperator>(S)) {
2390     switch (BO->getOpcode()) {
2391     case BO_AddAssign:
2392     case BO_SubAssign:
2393       if (GetInitVarDecl(BO->getLHS()) == Var)
2394         return SetStep(BO->getRHS(), BO->getOpcode() == BO_SubAssign);
2395       break;
2396     case BO_Assign:
2397       if (GetInitVarDecl(BO->getLHS()) == Var)
2398         return CheckIncRHS(BO->getRHS());
2399       break;
2400     default:
2401       break;
2402     }
2403   } else if (auto CE = dyn_cast<CXXOperatorCallExpr>(S)) {
2404     switch (CE->getOperator()) {
2405     case OO_PlusPlus:
2406     case OO_MinusMinus:
2407       if (GetInitVarDecl(CE->getArg(0)) == Var)
2408         return SetStep(
2409             SemaRef.ActOnIntegerConstant(
2410                         CE->getLocStart(),
2411                         ((CE->getOperator() == OO_MinusMinus) ? -1 : 1)).get(),
2412             false);
2413       break;
2414     case OO_PlusEqual:
2415     case OO_MinusEqual:
2416       if (GetInitVarDecl(CE->getArg(0)) == Var)
2417         return SetStep(CE->getArg(1), CE->getOperator() == OO_MinusEqual);
2418       break;
2419     case OO_Equal:
2420       if (GetInitVarDecl(CE->getArg(0)) == Var)
2421         return CheckIncRHS(CE->getArg(1));
2422       break;
2423     default:
2424       break;
2425     }
2426   }
2427   SemaRef.Diag(S->getLocStart(), diag::err_omp_loop_not_canonical_incr)
2428       << S->getSourceRange() << Var;
2429   return true;
2430 }
2431 
2432 /// \brief Build the expression to calculate the number of iterations.
2433 Expr *
2434 OpenMPIterationSpaceChecker::BuildNumIterations(Scope *S,
2435                                                 const bool LimitedType) const {
2436   ExprResult Diff;
2437   if (Var->getType()->isIntegerType() || Var->getType()->isPointerType() ||
2438       SemaRef.getLangOpts().CPlusPlus) {
2439     // Upper - Lower
2440     Expr *Upper = TestIsLessOp ? UB : LB;
2441     Expr *Lower = TestIsLessOp ? LB : UB;
2442 
2443     Diff = SemaRef.BuildBinOp(S, DefaultLoc, BO_Sub, Upper, Lower);
2444 
2445     if (!Diff.isUsable() && Var->getType()->getAsCXXRecordDecl()) {
2446       // BuildBinOp already emitted error, this one is to point user to upper
2447       // and lower bound, and to tell what is passed to 'operator-'.
2448       SemaRef.Diag(Upper->getLocStart(), diag::err_omp_loop_diff_cxx)
2449           << Upper->getSourceRange() << Lower->getSourceRange();
2450       return nullptr;
2451     }
2452   }
2453 
2454   if (!Diff.isUsable())
2455     return nullptr;
2456 
2457   // Upper - Lower [- 1]
2458   if (TestIsStrictOp)
2459     Diff = SemaRef.BuildBinOp(
2460         S, DefaultLoc, BO_Sub, Diff.get(),
2461         SemaRef.ActOnIntegerConstant(SourceLocation(), 1).get());
2462   if (!Diff.isUsable())
2463     return nullptr;
2464 
2465   // Upper - Lower [- 1] + Step
2466   Diff = SemaRef.BuildBinOp(S, DefaultLoc, BO_Add, Diff.get(),
2467                             Step->IgnoreImplicit());
2468   if (!Diff.isUsable())
2469     return nullptr;
2470 
2471   // Parentheses (for dumping/debugging purposes only).
2472   Diff = SemaRef.ActOnParenExpr(DefaultLoc, DefaultLoc, Diff.get());
2473   if (!Diff.isUsable())
2474     return nullptr;
2475 
2476   // (Upper - Lower [- 1] + Step) / Step
2477   Diff = SemaRef.BuildBinOp(S, DefaultLoc, BO_Div, Diff.get(),
2478                             Step->IgnoreImplicit());
2479   if (!Diff.isUsable())
2480     return nullptr;
2481 
2482   // OpenMP runtime requires 32-bit or 64-bit loop variables.
2483   if (LimitedType) {
2484     auto &C = SemaRef.Context;
2485     QualType Type = Diff.get()->getType();
2486     unsigned NewSize = (C.getTypeSize(Type) > 32) ? 64 : 32;
2487     if (NewSize != C.getTypeSize(Type)) {
2488       if (NewSize < C.getTypeSize(Type)) {
2489         assert(NewSize == 64 && "incorrect loop var size");
2490         SemaRef.Diag(DefaultLoc, diag::warn_omp_loop_64_bit_var)
2491             << InitSrcRange << ConditionSrcRange;
2492       }
2493       QualType NewType = C.getIntTypeForBitwidth(
2494           NewSize, Type->hasSignedIntegerRepresentation());
2495       Diff = SemaRef.PerformImplicitConversion(Diff.get(), NewType,
2496                                                Sema::AA_Converting, true);
2497       if (!Diff.isUsable())
2498         return nullptr;
2499     }
2500   }
2501 
2502   return Diff.get();
2503 }
2504 
2505 Expr *OpenMPIterationSpaceChecker::BuildPreCond(Scope *S, Expr *Cond) const {
2506   // Try to build LB <op> UB, where <op> is <, >, <=, or >=.
2507   bool Suppress = SemaRef.getDiagnostics().getSuppressAllDiagnostics();
2508   SemaRef.getDiagnostics().setSuppressAllDiagnostics(/*Val=*/true);
2509   auto CondExpr = SemaRef.BuildBinOp(
2510       S, DefaultLoc, TestIsLessOp ? (TestIsStrictOp ? BO_LT : BO_LE)
2511                                   : (TestIsStrictOp ? BO_GT : BO_GE),
2512       LB, UB);
2513   SemaRef.getDiagnostics().setSuppressAllDiagnostics(Suppress);
2514   // Otherwise use original loop conditon and evaluate it in runtime.
2515   return CondExpr.isUsable() ? CondExpr.get() : Cond;
2516 }
2517 
2518 /// \brief Build reference expression to the counter be used for codegen.
2519 Expr *OpenMPIterationSpaceChecker::BuildCounterVar() const {
2520   return buildDeclRefExpr(SemaRef, Var, Var->getType(), DefaultLoc);
2521 }
2522 
2523 /// \brief Build initization of the counter be used for codegen.
2524 Expr *OpenMPIterationSpaceChecker::BuildCounterInit() const { return LB; }
2525 
2526 /// \brief Build step of the counter be used for codegen.
2527 Expr *OpenMPIterationSpaceChecker::BuildCounterStep() const { return Step; }
2528 
2529 /// \brief Iteration space of a single for loop.
2530 struct LoopIterationSpace {
2531   /// \brief Condition of the loop.
2532   Expr *PreCond;
2533   /// \brief This expression calculates the number of iterations in the loop.
2534   /// It is always possible to calculate it before starting the loop.
2535   Expr *NumIterations;
2536   /// \brief The loop counter variable.
2537   Expr *CounterVar;
2538   /// \brief This is initializer for the initial value of #CounterVar.
2539   Expr *CounterInit;
2540   /// \brief This is step for the #CounterVar used to generate its update:
2541   /// #CounterVar = #CounterInit + #CounterStep * CurrentIteration.
2542   Expr *CounterStep;
2543   /// \brief Should step be subtracted?
2544   bool Subtract;
2545   /// \brief Source range of the loop init.
2546   SourceRange InitSrcRange;
2547   /// \brief Source range of the loop condition.
2548   SourceRange CondSrcRange;
2549   /// \brief Source range of the loop increment.
2550   SourceRange IncSrcRange;
2551 };
2552 
2553 } // namespace
2554 
2555 void Sema::ActOnOpenMPLoopInitialization(SourceLocation ForLoc, Stmt *Init) {
2556   assert(getLangOpts().OpenMP && "OpenMP is not active.");
2557   assert(Init && "Expected loop in canonical form.");
2558   unsigned CollapseIteration = DSAStack->getCollapseNumber();
2559   if (CollapseIteration > 0 &&
2560       isOpenMPLoopDirective(DSAStack->getCurrentDirective())) {
2561     OpenMPIterationSpaceChecker ISC(*this, ForLoc);
2562     if (!ISC.CheckInit(Init, /*EmitDiags=*/false)) {
2563       DSAStack->addLoopControlVariable(ISC.GetLoopVar());
2564     }
2565     DSAStack->setCollapseNumber(CollapseIteration - 1);
2566   }
2567 }
2568 
2569 /// \brief Called on a for stmt to check and extract its iteration space
2570 /// for further processing (such as collapsing).
2571 static bool CheckOpenMPIterationSpace(
2572     OpenMPDirectiveKind DKind, Stmt *S, Sema &SemaRef, DSAStackTy &DSA,
2573     unsigned CurrentNestedLoopCount, unsigned NestedLoopCount,
2574     Expr *NestedLoopCountExpr,
2575     llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA,
2576     LoopIterationSpace &ResultIterSpace) {
2577   // OpenMP [2.6, Canonical Loop Form]
2578   //   for (init-expr; test-expr; incr-expr) structured-block
2579   auto For = dyn_cast_or_null<ForStmt>(S);
2580   if (!For) {
2581     SemaRef.Diag(S->getLocStart(), diag::err_omp_not_for)
2582         << (NestedLoopCountExpr != nullptr) << getOpenMPDirectiveName(DKind)
2583         << NestedLoopCount << (CurrentNestedLoopCount > 0)
2584         << CurrentNestedLoopCount;
2585     if (NestedLoopCount > 1)
2586       SemaRef.Diag(NestedLoopCountExpr->getExprLoc(),
2587                    diag::note_omp_collapse_expr)
2588           << NestedLoopCountExpr->getSourceRange();
2589     return true;
2590   }
2591   assert(For->getBody());
2592 
2593   OpenMPIterationSpaceChecker ISC(SemaRef, For->getForLoc());
2594 
2595   // Check init.
2596   auto Init = For->getInit();
2597   if (ISC.CheckInit(Init)) {
2598     return true;
2599   }
2600 
2601   bool HasErrors = false;
2602 
2603   // Check loop variable's type.
2604   auto Var = ISC.GetLoopVar();
2605 
2606   // OpenMP [2.6, Canonical Loop Form]
2607   // Var is one of the following:
2608   //   A variable of signed or unsigned integer type.
2609   //   For C++, a variable of a random access iterator type.
2610   //   For C, a variable of a pointer type.
2611   auto VarType = Var->getType();
2612   if (!VarType->isDependentType() && !VarType->isIntegerType() &&
2613       !VarType->isPointerType() &&
2614       !(SemaRef.getLangOpts().CPlusPlus && VarType->isOverloadableType())) {
2615     SemaRef.Diag(Init->getLocStart(), diag::err_omp_loop_variable_type)
2616         << SemaRef.getLangOpts().CPlusPlus;
2617     HasErrors = true;
2618   }
2619 
2620   // OpenMP, 2.14.1.1 Data-sharing Attribute Rules for Variables Referenced in a
2621   // Construct
2622   // The loop iteration variable(s) in the associated for-loop(s) of a for or
2623   // parallel for construct is (are) private.
2624   // The loop iteration variable in the associated for-loop of a simd construct
2625   // with just one associated for-loop is linear with a constant-linear-step
2626   // that is the increment of the associated for-loop.
2627   // Exclude loop var from the list of variables with implicitly defined data
2628   // sharing attributes.
2629   VarsWithImplicitDSA.erase(Var);
2630 
2631   // OpenMP [2.14.1.1, Data-sharing Attribute Rules for Variables Referenced in
2632   // a Construct, C/C++].
2633   // The loop iteration variable in the associated for-loop of a simd construct
2634   // with just one associated for-loop may be listed in a linear clause with a
2635   // constant-linear-step that is the increment of the associated for-loop.
2636   // The loop iteration variable(s) in the associated for-loop(s) of a for or
2637   // parallel for construct may be listed in a private or lastprivate clause.
2638   DSAStackTy::DSAVarData DVar = DSA.getTopDSA(Var, false);
2639   auto LoopVarRefExpr = ISC.GetLoopVarRefExpr();
2640   // If LoopVarRefExpr is nullptr it means the corresponding loop variable is
2641   // declared in the loop and it is predetermined as a private.
2642   auto PredeterminedCKind =
2643       isOpenMPSimdDirective(DKind)
2644           ? ((NestedLoopCount == 1) ? OMPC_linear : OMPC_lastprivate)
2645           : OMPC_private;
2646   if (((isOpenMPSimdDirective(DKind) && DVar.CKind != OMPC_unknown &&
2647         DVar.CKind != OMPC_threadprivate && DVar.CKind != PredeterminedCKind) ||
2648        (isOpenMPWorksharingDirective(DKind) && !isOpenMPSimdDirective(DKind) &&
2649         DVar.CKind != OMPC_unknown && DVar.CKind != OMPC_private &&
2650         DVar.CKind != OMPC_lastprivate && DVar.CKind != OMPC_threadprivate)) &&
2651       ((DVar.CKind != OMPC_private && DVar.CKind != OMPC_threadprivate) ||
2652        DVar.RefExpr != nullptr)) {
2653     SemaRef.Diag(Init->getLocStart(), diag::err_omp_loop_var_dsa)
2654         << getOpenMPClauseName(DVar.CKind) << getOpenMPDirectiveName(DKind)
2655         << getOpenMPClauseName(PredeterminedCKind);
2656     if (DVar.RefExpr == nullptr)
2657       DVar.CKind = PredeterminedCKind;
2658     ReportOriginalDSA(SemaRef, &DSA, Var, DVar, /*IsLoopIterVar=*/true);
2659     HasErrors = true;
2660   } else if (LoopVarRefExpr != nullptr) {
2661     // Make the loop iteration variable private (for worksharing constructs),
2662     // linear (for simd directives with the only one associated loop) or
2663     // lastprivate (for simd directives with several collapsed loops).
2664     if (DVar.CKind == OMPC_unknown)
2665       DVar = DSA.hasDSA(Var, isOpenMPPrivate, MatchesAlways(),
2666                         /*FromParent=*/false);
2667     DSA.addDSA(Var, LoopVarRefExpr, PredeterminedCKind);
2668   }
2669 
2670   assert(isOpenMPLoopDirective(DKind) && "DSA for non-loop vars");
2671 
2672   // Check test-expr.
2673   HasErrors |= ISC.CheckCond(For->getCond());
2674 
2675   // Check incr-expr.
2676   HasErrors |= ISC.CheckInc(For->getInc());
2677 
2678   if (ISC.Dependent() || SemaRef.CurContext->isDependentContext() || HasErrors)
2679     return HasErrors;
2680 
2681   // Build the loop's iteration space representation.
2682   ResultIterSpace.PreCond = ISC.BuildPreCond(DSA.getCurScope(), For->getCond());
2683   ResultIterSpace.NumIterations = ISC.BuildNumIterations(
2684       DSA.getCurScope(), /* LimitedType */ isOpenMPWorksharingDirective(DKind));
2685   ResultIterSpace.CounterVar = ISC.BuildCounterVar();
2686   ResultIterSpace.CounterInit = ISC.BuildCounterInit();
2687   ResultIterSpace.CounterStep = ISC.BuildCounterStep();
2688   ResultIterSpace.InitSrcRange = ISC.GetInitSrcRange();
2689   ResultIterSpace.CondSrcRange = ISC.GetConditionSrcRange();
2690   ResultIterSpace.IncSrcRange = ISC.GetIncrementSrcRange();
2691   ResultIterSpace.Subtract = ISC.ShouldSubtractStep();
2692 
2693   HasErrors |= (ResultIterSpace.PreCond == nullptr ||
2694                 ResultIterSpace.NumIterations == nullptr ||
2695                 ResultIterSpace.CounterVar == nullptr ||
2696                 ResultIterSpace.CounterInit == nullptr ||
2697                 ResultIterSpace.CounterStep == nullptr);
2698 
2699   return HasErrors;
2700 }
2701 
2702 /// \brief Build 'VarRef = Start + Iter * Step'.
2703 static ExprResult BuildCounterUpdate(Sema &SemaRef, Scope *S,
2704                                      SourceLocation Loc, ExprResult VarRef,
2705                                      ExprResult Start, ExprResult Iter,
2706                                      ExprResult Step, bool Subtract) {
2707   // Add parentheses (for debugging purposes only).
2708   Iter = SemaRef.ActOnParenExpr(Loc, Loc, Iter.get());
2709   if (!VarRef.isUsable() || !Start.isUsable() || !Iter.isUsable() ||
2710       !Step.isUsable())
2711     return ExprError();
2712 
2713   ExprResult Update = SemaRef.BuildBinOp(S, Loc, BO_Mul, Iter.get(),
2714                                          Step.get()->IgnoreImplicit());
2715   if (!Update.isUsable())
2716     return ExprError();
2717 
2718   // Build 'VarRef = Start + Iter * Step'.
2719   Update = SemaRef.BuildBinOp(S, Loc, (Subtract ? BO_Sub : BO_Add),
2720                               Start.get()->IgnoreImplicit(), Update.get());
2721   if (!Update.isUsable())
2722     return ExprError();
2723 
2724   Update = SemaRef.PerformImplicitConversion(
2725       Update.get(), VarRef.get()->getType(), Sema::AA_Converting, true);
2726   if (!Update.isUsable())
2727     return ExprError();
2728 
2729   Update = SemaRef.BuildBinOp(S, Loc, BO_Assign, VarRef.get(), Update.get());
2730   return Update;
2731 }
2732 
2733 /// \brief Convert integer expression \a E to make it have at least \a Bits
2734 /// bits.
2735 static ExprResult WidenIterationCount(unsigned Bits, Expr *E,
2736                                       Sema &SemaRef) {
2737   if (E == nullptr)
2738     return ExprError();
2739   auto &C = SemaRef.Context;
2740   QualType OldType = E->getType();
2741   unsigned HasBits = C.getTypeSize(OldType);
2742   if (HasBits >= Bits)
2743     return ExprResult(E);
2744   // OK to convert to signed, because new type has more bits than old.
2745   QualType NewType = C.getIntTypeForBitwidth(Bits, /* Signed */ true);
2746   return SemaRef.PerformImplicitConversion(E, NewType, Sema::AA_Converting,
2747                                            true);
2748 }
2749 
2750 /// \brief Check if the given expression \a E is a constant integer that fits
2751 /// into \a Bits bits.
2752 static bool FitsInto(unsigned Bits, bool Signed, Expr *E, Sema &SemaRef) {
2753   if (E == nullptr)
2754     return false;
2755   llvm::APSInt Result;
2756   if (E->isIntegerConstantExpr(Result, SemaRef.Context))
2757     return Signed ? Result.isSignedIntN(Bits) : Result.isIntN(Bits);
2758   return false;
2759 }
2760 
2761 /// \brief Called on a for stmt to check itself and nested loops (if any).
2762 /// \return Returns 0 if one of the collapsed stmts is not canonical for loop,
2763 /// number of collapsed loops otherwise.
2764 static unsigned
2765 CheckOpenMPLoop(OpenMPDirectiveKind DKind, Expr *NestedLoopCountExpr,
2766                 Stmt *AStmt, Sema &SemaRef, DSAStackTy &DSA,
2767                 llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA,
2768                 OMPLoopDirective::HelperExprs &Built) {
2769   unsigned NestedLoopCount = 1;
2770   if (NestedLoopCountExpr) {
2771     // Found 'collapse' clause - calculate collapse number.
2772     llvm::APSInt Result;
2773     if (NestedLoopCountExpr->EvaluateAsInt(Result, SemaRef.getASTContext()))
2774       NestedLoopCount = Result.getLimitedValue();
2775   }
2776   // This is helper routine for loop directives (e.g., 'for', 'simd',
2777   // 'for simd', etc.).
2778   SmallVector<LoopIterationSpace, 4> IterSpaces;
2779   IterSpaces.resize(NestedLoopCount);
2780   Stmt *CurStmt = AStmt->IgnoreContainers(/* IgnoreCaptured */ true);
2781   for (unsigned Cnt = 0; Cnt < NestedLoopCount; ++Cnt) {
2782     if (CheckOpenMPIterationSpace(DKind, CurStmt, SemaRef, DSA, Cnt,
2783                                   NestedLoopCount, NestedLoopCountExpr,
2784                                   VarsWithImplicitDSA, IterSpaces[Cnt]))
2785       return 0;
2786     // Move on to the next nested for loop, or to the loop body.
2787     // OpenMP [2.8.1, simd construct, Restrictions]
2788     // All loops associated with the construct must be perfectly nested; that
2789     // is, there must be no intervening code nor any OpenMP directive between
2790     // any two loops.
2791     CurStmt = cast<ForStmt>(CurStmt)->getBody()->IgnoreContainers();
2792   }
2793 
2794   Built.clear(/* size */ NestedLoopCount);
2795 
2796   if (SemaRef.CurContext->isDependentContext())
2797     return NestedLoopCount;
2798 
2799   // An example of what is generated for the following code:
2800   //
2801   //   #pragma omp simd collapse(2)
2802   //   for (i = 0; i < NI; ++i)
2803   //     for (j = J0; j < NJ; j+=2) {
2804   //     <loop body>
2805   //   }
2806   //
2807   // We generate the code below.
2808   // Note: the loop body may be outlined in CodeGen.
2809   // Note: some counters may be C++ classes, operator- is used to find number of
2810   // iterations and operator+= to calculate counter value.
2811   // Note: decltype(NumIterations) must be integer type (in 'omp for', only i32
2812   // or i64 is currently supported).
2813   //
2814   //   #define NumIterations (NI * ((NJ - J0 - 1 + 2) / 2))
2815   //   for (int[32|64]_t IV = 0; IV < NumIterations; ++IV ) {
2816   //     .local.i = IV / ((NJ - J0 - 1 + 2) / 2);
2817   //     .local.j = J0 + (IV % ((NJ - J0 - 1 + 2) / 2)) * 2;
2818   //     // similar updates for vars in clauses (e.g. 'linear')
2819   //     <loop body (using local i and j)>
2820   //   }
2821   //   i = NI; // assign final values of counters
2822   //   j = NJ;
2823   //
2824 
2825   // Last iteration number is (I1 * I2 * ... In) - 1, where I1, I2 ... In are
2826   // the iteration counts of the collapsed for loops.
2827   // Precondition tests if there is at least one iteration (all conditions are
2828   // true).
2829   auto PreCond = ExprResult(IterSpaces[0].PreCond);
2830   auto N0 = IterSpaces[0].NumIterations;
2831   ExprResult LastIteration32 = WidenIterationCount(32 /* Bits */, N0, SemaRef);
2832   ExprResult LastIteration64 = WidenIterationCount(64 /* Bits */, N0, SemaRef);
2833 
2834   if (!LastIteration32.isUsable() || !LastIteration64.isUsable())
2835     return NestedLoopCount;
2836 
2837   auto &C = SemaRef.Context;
2838   bool AllCountsNeedLessThan32Bits = C.getTypeSize(N0->getType()) < 32;
2839 
2840   Scope *CurScope = DSA.getCurScope();
2841   for (unsigned Cnt = 1; Cnt < NestedLoopCount; ++Cnt) {
2842     if (PreCond.isUsable()) {
2843       PreCond = SemaRef.BuildBinOp(CurScope, SourceLocation(), BO_LAnd,
2844                                    PreCond.get(), IterSpaces[Cnt].PreCond);
2845     }
2846     auto N = IterSpaces[Cnt].NumIterations;
2847     AllCountsNeedLessThan32Bits &= C.getTypeSize(N->getType()) < 32;
2848     if (LastIteration32.isUsable())
2849       LastIteration32 = SemaRef.BuildBinOp(CurScope, SourceLocation(), BO_Mul,
2850                                            LastIteration32.get(), N);
2851     if (LastIteration64.isUsable())
2852       LastIteration64 = SemaRef.BuildBinOp(CurScope, SourceLocation(), BO_Mul,
2853                                            LastIteration64.get(), N);
2854   }
2855 
2856   // Choose either the 32-bit or 64-bit version.
2857   ExprResult LastIteration = LastIteration64;
2858   if (LastIteration32.isUsable() &&
2859       C.getTypeSize(LastIteration32.get()->getType()) == 32 &&
2860       (AllCountsNeedLessThan32Bits || NestedLoopCount == 1 ||
2861        FitsInto(
2862            32 /* Bits */,
2863            LastIteration32.get()->getType()->hasSignedIntegerRepresentation(),
2864            LastIteration64.get(), SemaRef)))
2865     LastIteration = LastIteration32;
2866 
2867   if (!LastIteration.isUsable())
2868     return 0;
2869 
2870   // Save the number of iterations.
2871   ExprResult NumIterations = LastIteration;
2872   {
2873     LastIteration = SemaRef.BuildBinOp(
2874         CurScope, SourceLocation(), BO_Sub, LastIteration.get(),
2875         SemaRef.ActOnIntegerConstant(SourceLocation(), 1).get());
2876     if (!LastIteration.isUsable())
2877       return 0;
2878   }
2879 
2880   // Calculate the last iteration number beforehand instead of doing this on
2881   // each iteration. Do not do this if the number of iterations may be kfold-ed.
2882   llvm::APSInt Result;
2883   bool IsConstant =
2884       LastIteration.get()->isIntegerConstantExpr(Result, SemaRef.Context);
2885   ExprResult CalcLastIteration;
2886   if (!IsConstant) {
2887     SourceLocation SaveLoc;
2888     VarDecl *SaveVar =
2889         buildVarDecl(SemaRef, SaveLoc, LastIteration.get()->getType(),
2890                      ".omp.last.iteration");
2891     ExprResult SaveRef = buildDeclRefExpr(
2892         SemaRef, SaveVar, LastIteration.get()->getType(), SaveLoc);
2893     CalcLastIteration = SemaRef.BuildBinOp(CurScope, SaveLoc, BO_Assign,
2894                                            SaveRef.get(), LastIteration.get());
2895     LastIteration = SaveRef;
2896 
2897     // Prepare SaveRef + 1.
2898     NumIterations = SemaRef.BuildBinOp(
2899         CurScope, SaveLoc, BO_Add, SaveRef.get(),
2900         SemaRef.ActOnIntegerConstant(SourceLocation(), 1).get());
2901     if (!NumIterations.isUsable())
2902       return 0;
2903   }
2904 
2905   SourceLocation InitLoc = IterSpaces[0].InitSrcRange.getBegin();
2906 
2907   QualType VType = LastIteration.get()->getType();
2908   // Build variables passed into runtime, nesessary for worksharing directives.
2909   ExprResult LB, UB, IL, ST, EUB;
2910   if (isOpenMPWorksharingDirective(DKind)) {
2911     // Lower bound variable, initialized with zero.
2912     VarDecl *LBDecl = buildVarDecl(SemaRef, InitLoc, VType, ".omp.lb");
2913     LB = buildDeclRefExpr(SemaRef, LBDecl, VType, InitLoc);
2914     SemaRef.AddInitializerToDecl(
2915         LBDecl, SemaRef.ActOnIntegerConstant(InitLoc, 0).get(),
2916         /*DirectInit*/ false, /*TypeMayContainAuto*/ false);
2917 
2918     // Upper bound variable, initialized with last iteration number.
2919     VarDecl *UBDecl = buildVarDecl(SemaRef, InitLoc, VType, ".omp.ub");
2920     UB = buildDeclRefExpr(SemaRef, UBDecl, VType, InitLoc);
2921     SemaRef.AddInitializerToDecl(UBDecl, LastIteration.get(),
2922                                  /*DirectInit*/ false,
2923                                  /*TypeMayContainAuto*/ false);
2924 
2925     // A 32-bit variable-flag where runtime returns 1 for the last iteration.
2926     // This will be used to implement clause 'lastprivate'.
2927     QualType Int32Ty = SemaRef.Context.getIntTypeForBitwidth(32, true);
2928     VarDecl *ILDecl = buildVarDecl(SemaRef, InitLoc, Int32Ty, ".omp.is_last");
2929     IL = buildDeclRefExpr(SemaRef, ILDecl, Int32Ty, InitLoc);
2930     SemaRef.AddInitializerToDecl(
2931         ILDecl, SemaRef.ActOnIntegerConstant(InitLoc, 0).get(),
2932         /*DirectInit*/ false, /*TypeMayContainAuto*/ false);
2933 
2934     // Stride variable returned by runtime (we initialize it to 1 by default).
2935     VarDecl *STDecl = buildVarDecl(SemaRef, InitLoc, VType, ".omp.stride");
2936     ST = buildDeclRefExpr(SemaRef, STDecl, VType, InitLoc);
2937     SemaRef.AddInitializerToDecl(
2938         STDecl, SemaRef.ActOnIntegerConstant(InitLoc, 1).get(),
2939         /*DirectInit*/ false, /*TypeMayContainAuto*/ false);
2940 
2941     // Build expression: UB = min(UB, LastIteration)
2942     // It is nesessary for CodeGen of directives with static scheduling.
2943     ExprResult IsUBGreater = SemaRef.BuildBinOp(CurScope, InitLoc, BO_GT,
2944                                                 UB.get(), LastIteration.get());
2945     ExprResult CondOp = SemaRef.ActOnConditionalOp(
2946         InitLoc, InitLoc, IsUBGreater.get(), LastIteration.get(), UB.get());
2947     EUB = SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, UB.get(),
2948                              CondOp.get());
2949     EUB = SemaRef.ActOnFinishFullExpr(EUB.get());
2950   }
2951 
2952   // Build the iteration variable and its initialization before loop.
2953   ExprResult IV;
2954   ExprResult Init;
2955   {
2956     VarDecl *IVDecl = buildVarDecl(SemaRef, InitLoc, VType, ".omp.iv");
2957     IV = buildDeclRefExpr(SemaRef, IVDecl, VType, InitLoc);
2958     Expr *RHS = isOpenMPWorksharingDirective(DKind)
2959                     ? LB.get()
2960                     : SemaRef.ActOnIntegerConstant(SourceLocation(), 0).get();
2961     Init = SemaRef.BuildBinOp(CurScope, InitLoc, BO_Assign, IV.get(), RHS);
2962     Init = SemaRef.ActOnFinishFullExpr(Init.get());
2963   }
2964 
2965   // Loop condition (IV < NumIterations) or (IV <= UB) for worksharing loops.
2966   SourceLocation CondLoc;
2967   ExprResult Cond =
2968       isOpenMPWorksharingDirective(DKind)
2969           ? SemaRef.BuildBinOp(CurScope, CondLoc, BO_LE, IV.get(), UB.get())
2970           : SemaRef.BuildBinOp(CurScope, CondLoc, BO_LT, IV.get(),
2971                                NumIterations.get());
2972 
2973   // Loop increment (IV = IV + 1)
2974   SourceLocation IncLoc;
2975   ExprResult Inc =
2976       SemaRef.BuildBinOp(CurScope, IncLoc, BO_Add, IV.get(),
2977                          SemaRef.ActOnIntegerConstant(IncLoc, 1).get());
2978   if (!Inc.isUsable())
2979     return 0;
2980   Inc = SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, IV.get(), Inc.get());
2981   Inc = SemaRef.ActOnFinishFullExpr(Inc.get());
2982   if (!Inc.isUsable())
2983     return 0;
2984 
2985   // Increments for worksharing loops (LB = LB + ST; UB = UB + ST).
2986   // Used for directives with static scheduling.
2987   ExprResult NextLB, NextUB;
2988   if (isOpenMPWorksharingDirective(DKind)) {
2989     // LB + ST
2990     NextLB = SemaRef.BuildBinOp(CurScope, IncLoc, BO_Add, LB.get(), ST.get());
2991     if (!NextLB.isUsable())
2992       return 0;
2993     // LB = LB + ST
2994     NextLB =
2995         SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, LB.get(), NextLB.get());
2996     NextLB = SemaRef.ActOnFinishFullExpr(NextLB.get());
2997     if (!NextLB.isUsable())
2998       return 0;
2999     // UB + ST
3000     NextUB = SemaRef.BuildBinOp(CurScope, IncLoc, BO_Add, UB.get(), ST.get());
3001     if (!NextUB.isUsable())
3002       return 0;
3003     // UB = UB + ST
3004     NextUB =
3005         SemaRef.BuildBinOp(CurScope, IncLoc, BO_Assign, UB.get(), NextUB.get());
3006     NextUB = SemaRef.ActOnFinishFullExpr(NextUB.get());
3007     if (!NextUB.isUsable())
3008       return 0;
3009   }
3010 
3011   // Build updates and final values of the loop counters.
3012   bool HasErrors = false;
3013   Built.Counters.resize(NestedLoopCount);
3014   Built.Updates.resize(NestedLoopCount);
3015   Built.Finals.resize(NestedLoopCount);
3016   {
3017     ExprResult Div;
3018     // Go from inner nested loop to outer.
3019     for (int Cnt = NestedLoopCount - 1; Cnt >= 0; --Cnt) {
3020       LoopIterationSpace &IS = IterSpaces[Cnt];
3021       SourceLocation UpdLoc = IS.IncSrcRange.getBegin();
3022       // Build: Iter = (IV / Div) % IS.NumIters
3023       // where Div is product of previous iterations' IS.NumIters.
3024       ExprResult Iter;
3025       if (Div.isUsable()) {
3026         Iter =
3027             SemaRef.BuildBinOp(CurScope, UpdLoc, BO_Div, IV.get(), Div.get());
3028       } else {
3029         Iter = IV;
3030         assert((Cnt == (int)NestedLoopCount - 1) &&
3031                "unusable div expected on first iteration only");
3032       }
3033 
3034       if (Cnt != 0 && Iter.isUsable())
3035         Iter = SemaRef.BuildBinOp(CurScope, UpdLoc, BO_Rem, Iter.get(),
3036                                   IS.NumIterations);
3037       if (!Iter.isUsable()) {
3038         HasErrors = true;
3039         break;
3040       }
3041 
3042       // Build update: IS.CounterVar(Private) = IS.Start + Iter * IS.Step
3043       auto *CounterVar = buildDeclRefExpr(
3044           SemaRef, cast<VarDecl>(cast<DeclRefExpr>(IS.CounterVar)->getDecl()),
3045           IS.CounterVar->getType(), IS.CounterVar->getExprLoc(),
3046           /*RefersToCapture=*/true);
3047       ExprResult Update =
3048           BuildCounterUpdate(SemaRef, CurScope, UpdLoc, CounterVar,
3049                              IS.CounterInit, Iter, IS.CounterStep, IS.Subtract);
3050       if (!Update.isUsable()) {
3051         HasErrors = true;
3052         break;
3053       }
3054 
3055       // Build final: IS.CounterVar = IS.Start + IS.NumIters * IS.Step
3056       ExprResult Final = BuildCounterUpdate(
3057           SemaRef, CurScope, UpdLoc, CounterVar, IS.CounterInit,
3058           IS.NumIterations, IS.CounterStep, IS.Subtract);
3059       if (!Final.isUsable()) {
3060         HasErrors = true;
3061         break;
3062       }
3063 
3064       // Build Div for the next iteration: Div <- Div * IS.NumIters
3065       if (Cnt != 0) {
3066         if (Div.isUnset())
3067           Div = IS.NumIterations;
3068         else
3069           Div = SemaRef.BuildBinOp(CurScope, UpdLoc, BO_Mul, Div.get(),
3070                                    IS.NumIterations);
3071 
3072         // Add parentheses (for debugging purposes only).
3073         if (Div.isUsable())
3074           Div = SemaRef.ActOnParenExpr(UpdLoc, UpdLoc, Div.get());
3075         if (!Div.isUsable()) {
3076           HasErrors = true;
3077           break;
3078         }
3079       }
3080       if (!Update.isUsable() || !Final.isUsable()) {
3081         HasErrors = true;
3082         break;
3083       }
3084       // Save results
3085       Built.Counters[Cnt] = IS.CounterVar;
3086       Built.Updates[Cnt] = Update.get();
3087       Built.Finals[Cnt] = Final.get();
3088     }
3089   }
3090 
3091   if (HasErrors)
3092     return 0;
3093 
3094   // Save results
3095   Built.IterationVarRef = IV.get();
3096   Built.LastIteration = LastIteration.get();
3097   Built.NumIterations = NumIterations.get();
3098   Built.CalcLastIteration = CalcLastIteration.get();
3099   Built.PreCond = PreCond.get();
3100   Built.Cond = Cond.get();
3101   Built.Init = Init.get();
3102   Built.Inc = Inc.get();
3103   Built.LB = LB.get();
3104   Built.UB = UB.get();
3105   Built.IL = IL.get();
3106   Built.ST = ST.get();
3107   Built.EUB = EUB.get();
3108   Built.NLB = NextLB.get();
3109   Built.NUB = NextUB.get();
3110 
3111   return NestedLoopCount;
3112 }
3113 
3114 static Expr *GetCollapseNumberExpr(ArrayRef<OMPClause *> Clauses) {
3115   auto &&CollapseFilter = [](const OMPClause *C) -> bool {
3116     return C->getClauseKind() == OMPC_collapse;
3117   };
3118   OMPExecutableDirective::filtered_clause_iterator<decltype(CollapseFilter)> I(
3119       Clauses, std::move(CollapseFilter));
3120   if (I)
3121     return cast<OMPCollapseClause>(*I)->getNumForLoops();
3122   return nullptr;
3123 }
3124 
3125 StmtResult Sema::ActOnOpenMPSimdDirective(
3126     ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
3127     SourceLocation EndLoc,
3128     llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA) {
3129   OMPLoopDirective::HelperExprs B;
3130   // In presence of clause 'collapse', it will define the nested loops number.
3131   unsigned NestedLoopCount =
3132       CheckOpenMPLoop(OMPD_simd, GetCollapseNumberExpr(Clauses), AStmt, *this,
3133                       *DSAStack, VarsWithImplicitDSA, B);
3134   if (NestedLoopCount == 0)
3135     return StmtError();
3136 
3137   assert((CurContext->isDependentContext() || B.builtAll()) &&
3138          "omp simd loop exprs were not built");
3139 
3140   if (!CurContext->isDependentContext()) {
3141     // Finalize the clauses that need pre-built expressions for CodeGen.
3142     for (auto C : Clauses) {
3143       if (auto LC = dyn_cast<OMPLinearClause>(C))
3144         if (FinishOpenMPLinearClause(*LC, cast<DeclRefExpr>(B.IterationVarRef),
3145                                      B.NumIterations, *this, CurScope))
3146           return StmtError();
3147     }
3148   }
3149 
3150   getCurFunction()->setHasBranchProtectedScope();
3151   return OMPSimdDirective::Create(Context, StartLoc, EndLoc, NestedLoopCount,
3152                                   Clauses, AStmt, B);
3153 }
3154 
3155 StmtResult Sema::ActOnOpenMPForDirective(
3156     ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
3157     SourceLocation EndLoc,
3158     llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA) {
3159   OMPLoopDirective::HelperExprs B;
3160   // In presence of clause 'collapse', it will define the nested loops number.
3161   unsigned NestedLoopCount =
3162       CheckOpenMPLoop(OMPD_for, GetCollapseNumberExpr(Clauses), AStmt, *this,
3163                       *DSAStack, VarsWithImplicitDSA, B);
3164   if (NestedLoopCount == 0)
3165     return StmtError();
3166 
3167   assert((CurContext->isDependentContext() || B.builtAll()) &&
3168          "omp for loop exprs were not built");
3169 
3170   getCurFunction()->setHasBranchProtectedScope();
3171   return OMPForDirective::Create(Context, StartLoc, EndLoc, NestedLoopCount,
3172                                  Clauses, AStmt, B);
3173 }
3174 
3175 StmtResult Sema::ActOnOpenMPForSimdDirective(
3176     ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
3177     SourceLocation EndLoc,
3178     llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA) {
3179   OMPLoopDirective::HelperExprs B;
3180   // In presence of clause 'collapse', it will define the nested loops number.
3181   unsigned NestedLoopCount =
3182       CheckOpenMPLoop(OMPD_for_simd, GetCollapseNumberExpr(Clauses), AStmt,
3183                       *this, *DSAStack, VarsWithImplicitDSA, B);
3184   if (NestedLoopCount == 0)
3185     return StmtError();
3186 
3187   assert((CurContext->isDependentContext() || B.builtAll()) &&
3188          "omp for simd loop exprs were not built");
3189 
3190   if (!CurContext->isDependentContext()) {
3191     // Finalize the clauses that need pre-built expressions for CodeGen.
3192     for (auto C : Clauses) {
3193       if (auto LC = dyn_cast<OMPLinearClause>(C))
3194         if (FinishOpenMPLinearClause(*LC, cast<DeclRefExpr>(B.IterationVarRef),
3195                                      B.NumIterations, *this, CurScope))
3196           return StmtError();
3197     }
3198   }
3199 
3200   getCurFunction()->setHasBranchProtectedScope();
3201   return OMPForSimdDirective::Create(Context, StartLoc, EndLoc, NestedLoopCount,
3202                                      Clauses, AStmt, B);
3203 }
3204 
3205 StmtResult Sema::ActOnOpenMPSectionsDirective(ArrayRef<OMPClause *> Clauses,
3206                                               Stmt *AStmt,
3207                                               SourceLocation StartLoc,
3208                                               SourceLocation EndLoc) {
3209   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3210   auto BaseStmt = AStmt;
3211   while (CapturedStmt *CS = dyn_cast_or_null<CapturedStmt>(BaseStmt))
3212     BaseStmt = CS->getCapturedStmt();
3213   if (auto C = dyn_cast_or_null<CompoundStmt>(BaseStmt)) {
3214     auto S = C->children();
3215     if (!S)
3216       return StmtError();
3217     // All associated statements must be '#pragma omp section' except for
3218     // the first one.
3219     for (++S; S; ++S) {
3220       auto SectionStmt = *S;
3221       if (!SectionStmt || !isa<OMPSectionDirective>(SectionStmt)) {
3222         if (SectionStmt)
3223           Diag(SectionStmt->getLocStart(),
3224                diag::err_omp_sections_substmt_not_section);
3225         return StmtError();
3226       }
3227     }
3228   } else {
3229     Diag(AStmt->getLocStart(), diag::err_omp_sections_not_compound_stmt);
3230     return StmtError();
3231   }
3232 
3233   getCurFunction()->setHasBranchProtectedScope();
3234 
3235   return OMPSectionsDirective::Create(Context, StartLoc, EndLoc, Clauses,
3236                                       AStmt);
3237 }
3238 
3239 StmtResult Sema::ActOnOpenMPSectionDirective(Stmt *AStmt,
3240                                              SourceLocation StartLoc,
3241                                              SourceLocation EndLoc) {
3242   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3243 
3244   getCurFunction()->setHasBranchProtectedScope();
3245 
3246   return OMPSectionDirective::Create(Context, StartLoc, EndLoc, AStmt);
3247 }
3248 
3249 StmtResult Sema::ActOnOpenMPSingleDirective(ArrayRef<OMPClause *> Clauses,
3250                                             Stmt *AStmt,
3251                                             SourceLocation StartLoc,
3252                                             SourceLocation EndLoc) {
3253   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3254 
3255   getCurFunction()->setHasBranchProtectedScope();
3256 
3257   // OpenMP [2.7.3, single Construct, Restrictions]
3258   // The copyprivate clause must not be used with the nowait clause.
3259   OMPClause *Nowait = nullptr;
3260   OMPClause *Copyprivate = nullptr;
3261   for (auto *Clause : Clauses) {
3262     if (Clause->getClauseKind() == OMPC_nowait)
3263       Nowait = Clause;
3264     else if (Clause->getClauseKind() == OMPC_copyprivate)
3265       Copyprivate = Clause;
3266     if (Copyprivate && Nowait) {
3267       Diag(Copyprivate->getLocStart(),
3268            diag::err_omp_single_copyprivate_with_nowait);
3269       Diag(Nowait->getLocStart(), diag::note_omp_nowait_clause_here);
3270       return StmtError();
3271     }
3272   }
3273 
3274   return OMPSingleDirective::Create(Context, StartLoc, EndLoc, Clauses, AStmt);
3275 }
3276 
3277 StmtResult Sema::ActOnOpenMPMasterDirective(Stmt *AStmt,
3278                                             SourceLocation StartLoc,
3279                                             SourceLocation EndLoc) {
3280   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3281 
3282   getCurFunction()->setHasBranchProtectedScope();
3283 
3284   return OMPMasterDirective::Create(Context, StartLoc, EndLoc, AStmt);
3285 }
3286 
3287 StmtResult
3288 Sema::ActOnOpenMPCriticalDirective(const DeclarationNameInfo &DirName,
3289                                    Stmt *AStmt, SourceLocation StartLoc,
3290                                    SourceLocation EndLoc) {
3291   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3292 
3293   getCurFunction()->setHasBranchProtectedScope();
3294 
3295   return OMPCriticalDirective::Create(Context, DirName, StartLoc, EndLoc,
3296                                       AStmt);
3297 }
3298 
3299 StmtResult Sema::ActOnOpenMPParallelForDirective(
3300     ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
3301     SourceLocation EndLoc,
3302     llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA) {
3303   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3304   CapturedStmt *CS = cast<CapturedStmt>(AStmt);
3305   // 1.2.2 OpenMP Language Terminology
3306   // Structured block - An executable statement with a single entry at the
3307   // top and a single exit at the bottom.
3308   // The point of exit cannot be a branch out of the structured block.
3309   // longjmp() and throw() must not violate the entry/exit criteria.
3310   CS->getCapturedDecl()->setNothrow();
3311 
3312   OMPLoopDirective::HelperExprs B;
3313   // In presence of clause 'collapse', it will define the nested loops number.
3314   unsigned NestedLoopCount =
3315       CheckOpenMPLoop(OMPD_parallel_for, GetCollapseNumberExpr(Clauses), AStmt,
3316                       *this, *DSAStack, VarsWithImplicitDSA, B);
3317   if (NestedLoopCount == 0)
3318     return StmtError();
3319 
3320   assert((CurContext->isDependentContext() || B.builtAll()) &&
3321          "omp parallel for loop exprs were not built");
3322 
3323   getCurFunction()->setHasBranchProtectedScope();
3324   return OMPParallelForDirective::Create(Context, StartLoc, EndLoc,
3325                                          NestedLoopCount, Clauses, AStmt, B);
3326 }
3327 
3328 StmtResult Sema::ActOnOpenMPParallelForSimdDirective(
3329     ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
3330     SourceLocation EndLoc,
3331     llvm::DenseMap<VarDecl *, Expr *> &VarsWithImplicitDSA) {
3332   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3333   CapturedStmt *CS = cast<CapturedStmt>(AStmt);
3334   // 1.2.2 OpenMP Language Terminology
3335   // Structured block - An executable statement with a single entry at the
3336   // top and a single exit at the bottom.
3337   // The point of exit cannot be a branch out of the structured block.
3338   // longjmp() and throw() must not violate the entry/exit criteria.
3339   CS->getCapturedDecl()->setNothrow();
3340 
3341   OMPLoopDirective::HelperExprs B;
3342   // In presence of clause 'collapse', it will define the nested loops number.
3343   unsigned NestedLoopCount =
3344       CheckOpenMPLoop(OMPD_parallel_for_simd, GetCollapseNumberExpr(Clauses),
3345                       AStmt, *this, *DSAStack, VarsWithImplicitDSA, B);
3346   if (NestedLoopCount == 0)
3347     return StmtError();
3348 
3349   if (!CurContext->isDependentContext()) {
3350     // Finalize the clauses that need pre-built expressions for CodeGen.
3351     for (auto C : Clauses) {
3352       if (auto LC = dyn_cast<OMPLinearClause>(C))
3353         if (FinishOpenMPLinearClause(*LC, cast<DeclRefExpr>(B.IterationVarRef),
3354                                      B.NumIterations, *this, CurScope))
3355           return StmtError();
3356     }
3357   }
3358 
3359   getCurFunction()->setHasBranchProtectedScope();
3360   return OMPParallelForSimdDirective::Create(
3361       Context, StartLoc, EndLoc, NestedLoopCount, Clauses, AStmt, B);
3362 }
3363 
3364 StmtResult
3365 Sema::ActOnOpenMPParallelSectionsDirective(ArrayRef<OMPClause *> Clauses,
3366                                            Stmt *AStmt, SourceLocation StartLoc,
3367                                            SourceLocation EndLoc) {
3368   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3369   auto BaseStmt = AStmt;
3370   while (CapturedStmt *CS = dyn_cast_or_null<CapturedStmt>(BaseStmt))
3371     BaseStmt = CS->getCapturedStmt();
3372   if (auto C = dyn_cast_or_null<CompoundStmt>(BaseStmt)) {
3373     auto S = C->children();
3374     if (!S)
3375       return StmtError();
3376     // All associated statements must be '#pragma omp section' except for
3377     // the first one.
3378     for (++S; S; ++S) {
3379       auto SectionStmt = *S;
3380       if (!SectionStmt || !isa<OMPSectionDirective>(SectionStmt)) {
3381         if (SectionStmt)
3382           Diag(SectionStmt->getLocStart(),
3383                diag::err_omp_parallel_sections_substmt_not_section);
3384         return StmtError();
3385       }
3386     }
3387   } else {
3388     Diag(AStmt->getLocStart(),
3389          diag::err_omp_parallel_sections_not_compound_stmt);
3390     return StmtError();
3391   }
3392 
3393   getCurFunction()->setHasBranchProtectedScope();
3394 
3395   return OMPParallelSectionsDirective::Create(Context, StartLoc, EndLoc,
3396                                               Clauses, AStmt);
3397 }
3398 
3399 StmtResult Sema::ActOnOpenMPTaskDirective(ArrayRef<OMPClause *> Clauses,
3400                                           Stmt *AStmt, SourceLocation StartLoc,
3401                                           SourceLocation EndLoc) {
3402   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3403   CapturedStmt *CS = cast<CapturedStmt>(AStmt);
3404   // 1.2.2 OpenMP Language Terminology
3405   // Structured block - An executable statement with a single entry at the
3406   // top and a single exit at the bottom.
3407   // The point of exit cannot be a branch out of the structured block.
3408   // longjmp() and throw() must not violate the entry/exit criteria.
3409   CS->getCapturedDecl()->setNothrow();
3410 
3411   getCurFunction()->setHasBranchProtectedScope();
3412 
3413   return OMPTaskDirective::Create(Context, StartLoc, EndLoc, Clauses, AStmt);
3414 }
3415 
3416 StmtResult Sema::ActOnOpenMPTaskyieldDirective(SourceLocation StartLoc,
3417                                                SourceLocation EndLoc) {
3418   return OMPTaskyieldDirective::Create(Context, StartLoc, EndLoc);
3419 }
3420 
3421 StmtResult Sema::ActOnOpenMPBarrierDirective(SourceLocation StartLoc,
3422                                              SourceLocation EndLoc) {
3423   return OMPBarrierDirective::Create(Context, StartLoc, EndLoc);
3424 }
3425 
3426 StmtResult Sema::ActOnOpenMPTaskwaitDirective(SourceLocation StartLoc,
3427                                               SourceLocation EndLoc) {
3428   return OMPTaskwaitDirective::Create(Context, StartLoc, EndLoc);
3429 }
3430 
3431 StmtResult Sema::ActOnOpenMPTaskgroupDirective(Stmt *AStmt,
3432                                                SourceLocation StartLoc,
3433                                                SourceLocation EndLoc) {
3434   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3435 
3436   getCurFunction()->setHasBranchProtectedScope();
3437 
3438   return OMPTaskgroupDirective::Create(Context, StartLoc, EndLoc, AStmt);
3439 }
3440 
3441 StmtResult Sema::ActOnOpenMPFlushDirective(ArrayRef<OMPClause *> Clauses,
3442                                            SourceLocation StartLoc,
3443                                            SourceLocation EndLoc) {
3444   assert(Clauses.size() <= 1 && "Extra clauses in flush directive");
3445   return OMPFlushDirective::Create(Context, StartLoc, EndLoc, Clauses);
3446 }
3447 
3448 StmtResult Sema::ActOnOpenMPOrderedDirective(Stmt *AStmt,
3449                                              SourceLocation StartLoc,
3450                                              SourceLocation EndLoc) {
3451   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3452 
3453   getCurFunction()->setHasBranchProtectedScope();
3454 
3455   return OMPOrderedDirective::Create(Context, StartLoc, EndLoc, AStmt);
3456 }
3457 
3458 namespace {
3459 /// \brief Helper class for checking expression in 'omp atomic [update]'
3460 /// construct.
3461 class OpenMPAtomicUpdateChecker {
3462   /// \brief Error results for atomic update expressions.
3463   enum ExprAnalysisErrorCode {
3464     /// \brief A statement is not an expression statement.
3465     NotAnExpression,
3466     /// \brief Expression is not builtin binary or unary operation.
3467     NotABinaryOrUnaryExpression,
3468     /// \brief Unary operation is not post-/pre- increment/decrement operation.
3469     NotAnUnaryIncDecExpression,
3470     /// \brief An expression is not of scalar type.
3471     NotAScalarType,
3472     /// \brief A binary operation is not an assignment operation.
3473     NotAnAssignmentOp,
3474     /// \brief RHS part of the binary operation is not a binary expression.
3475     NotABinaryExpression,
3476     /// \brief RHS part is not additive/multiplicative/shift/biwise binary
3477     /// expression.
3478     NotABinaryOperator,
3479     /// \brief RHS binary operation does not have reference to the updated LHS
3480     /// part.
3481     NotAnUpdateExpression,
3482     /// \brief No errors is found.
3483     NoError
3484   };
3485   /// \brief Reference to Sema.
3486   Sema &SemaRef;
3487   /// \brief A location for note diagnostics (when error is found).
3488   SourceLocation NoteLoc;
3489   /// \brief 'x' lvalue part of the source atomic expression.
3490   Expr *X;
3491   /// \brief 'expr' rvalue part of the source atomic expression.
3492   Expr *E;
3493   /// \brief Helper expression of the form
3494   /// 'OpaqueValueExpr(x) binop OpaqueValueExpr(expr)' or
3495   /// 'OpaqueValueExpr(expr) binop OpaqueValueExpr(x)'.
3496   Expr *UpdateExpr;
3497   /// \brief Is 'x' a LHS in a RHS part of full update expression. It is
3498   /// important for non-associative operations.
3499   bool IsXLHSInRHSPart;
3500   BinaryOperatorKind Op;
3501   SourceLocation OpLoc;
3502   /// \brief true if the source expression is a postfix unary operation, false
3503   /// if it is a prefix unary operation.
3504   bool IsPostfixUpdate;
3505 
3506 public:
3507   OpenMPAtomicUpdateChecker(Sema &SemaRef)
3508       : SemaRef(SemaRef), X(nullptr), E(nullptr), UpdateExpr(nullptr),
3509         IsXLHSInRHSPart(false), Op(BO_PtrMemD), IsPostfixUpdate(false) {}
3510   /// \brief Check specified statement that it is suitable for 'atomic update'
3511   /// constructs and extract 'x', 'expr' and Operation from the original
3512   /// expression. If DiagId and NoteId == 0, then only check is performed
3513   /// without error notification.
3514   /// \param DiagId Diagnostic which should be emitted if error is found.
3515   /// \param NoteId Diagnostic note for the main error message.
3516   /// \return true if statement is not an update expression, false otherwise.
3517   bool checkStatement(Stmt *S, unsigned DiagId = 0, unsigned NoteId = 0);
3518   /// \brief Return the 'x' lvalue part of the source atomic expression.
3519   Expr *getX() const { return X; }
3520   /// \brief Return the 'expr' rvalue part of the source atomic expression.
3521   Expr *getExpr() const { return E; }
3522   /// \brief Return the update expression used in calculation of the updated
3523   /// value. Always has form 'OpaqueValueExpr(x) binop OpaqueValueExpr(expr)' or
3524   /// 'OpaqueValueExpr(expr) binop OpaqueValueExpr(x)'.
3525   Expr *getUpdateExpr() const { return UpdateExpr; }
3526   /// \brief Return true if 'x' is LHS in RHS part of full update expression,
3527   /// false otherwise.
3528   bool isXLHSInRHSPart() const { return IsXLHSInRHSPart; }
3529 
3530   /// \brief true if the source expression is a postfix unary operation, false
3531   /// if it is a prefix unary operation.
3532   bool isPostfixUpdate() const { return IsPostfixUpdate; }
3533 
3534 private:
3535   bool checkBinaryOperation(BinaryOperator *AtomicBinOp, unsigned DiagId = 0,
3536                             unsigned NoteId = 0);
3537 };
3538 } // namespace
3539 
3540 bool OpenMPAtomicUpdateChecker::checkBinaryOperation(
3541     BinaryOperator *AtomicBinOp, unsigned DiagId, unsigned NoteId) {
3542   ExprAnalysisErrorCode ErrorFound = NoError;
3543   SourceLocation ErrorLoc, NoteLoc;
3544   SourceRange ErrorRange, NoteRange;
3545   // Allowed constructs are:
3546   //  x = x binop expr;
3547   //  x = expr binop x;
3548   if (AtomicBinOp->getOpcode() == BO_Assign) {
3549     X = AtomicBinOp->getLHS();
3550     if (auto *AtomicInnerBinOp = dyn_cast<BinaryOperator>(
3551             AtomicBinOp->getRHS()->IgnoreParenImpCasts())) {
3552       if (AtomicInnerBinOp->isMultiplicativeOp() ||
3553           AtomicInnerBinOp->isAdditiveOp() || AtomicInnerBinOp->isShiftOp() ||
3554           AtomicInnerBinOp->isBitwiseOp()) {
3555         Op = AtomicInnerBinOp->getOpcode();
3556         OpLoc = AtomicInnerBinOp->getOperatorLoc();
3557         auto *LHS = AtomicInnerBinOp->getLHS();
3558         auto *RHS = AtomicInnerBinOp->getRHS();
3559         llvm::FoldingSetNodeID XId, LHSId, RHSId;
3560         X->IgnoreParenImpCasts()->Profile(XId, SemaRef.getASTContext(),
3561                                           /*Canonical=*/true);
3562         LHS->IgnoreParenImpCasts()->Profile(LHSId, SemaRef.getASTContext(),
3563                                             /*Canonical=*/true);
3564         RHS->IgnoreParenImpCasts()->Profile(RHSId, SemaRef.getASTContext(),
3565                                             /*Canonical=*/true);
3566         if (XId == LHSId) {
3567           E = RHS;
3568           IsXLHSInRHSPart = true;
3569         } else if (XId == RHSId) {
3570           E = LHS;
3571           IsXLHSInRHSPart = false;
3572         } else {
3573           ErrorLoc = AtomicInnerBinOp->getExprLoc();
3574           ErrorRange = AtomicInnerBinOp->getSourceRange();
3575           NoteLoc = X->getExprLoc();
3576           NoteRange = X->getSourceRange();
3577           ErrorFound = NotAnUpdateExpression;
3578         }
3579       } else {
3580         ErrorLoc = AtomicInnerBinOp->getExprLoc();
3581         ErrorRange = AtomicInnerBinOp->getSourceRange();
3582         NoteLoc = AtomicInnerBinOp->getOperatorLoc();
3583         NoteRange = SourceRange(NoteLoc, NoteLoc);
3584         ErrorFound = NotABinaryOperator;
3585       }
3586     } else {
3587       NoteLoc = ErrorLoc = AtomicBinOp->getRHS()->getExprLoc();
3588       NoteRange = ErrorRange = AtomicBinOp->getRHS()->getSourceRange();
3589       ErrorFound = NotABinaryExpression;
3590     }
3591   } else {
3592     ErrorLoc = AtomicBinOp->getExprLoc();
3593     ErrorRange = AtomicBinOp->getSourceRange();
3594     NoteLoc = AtomicBinOp->getOperatorLoc();
3595     NoteRange = SourceRange(NoteLoc, NoteLoc);
3596     ErrorFound = NotAnAssignmentOp;
3597   }
3598   if (ErrorFound != NoError && DiagId != 0 && NoteId != 0) {
3599     SemaRef.Diag(ErrorLoc, DiagId) << ErrorRange;
3600     SemaRef.Diag(NoteLoc, NoteId) << ErrorFound << NoteRange;
3601     return true;
3602   } else if (SemaRef.CurContext->isDependentContext())
3603     E = X = UpdateExpr = nullptr;
3604   return ErrorFound != NoError;
3605 }
3606 
3607 bool OpenMPAtomicUpdateChecker::checkStatement(Stmt *S, unsigned DiagId,
3608                                                unsigned NoteId) {
3609   ExprAnalysisErrorCode ErrorFound = NoError;
3610   SourceLocation ErrorLoc, NoteLoc;
3611   SourceRange ErrorRange, NoteRange;
3612   // Allowed constructs are:
3613   //  x++;
3614   //  x--;
3615   //  ++x;
3616   //  --x;
3617   //  x binop= expr;
3618   //  x = x binop expr;
3619   //  x = expr binop x;
3620   if (auto *AtomicBody = dyn_cast<Expr>(S)) {
3621     AtomicBody = AtomicBody->IgnoreParenImpCasts();
3622     if (AtomicBody->getType()->isScalarType() ||
3623         AtomicBody->isInstantiationDependent()) {
3624       if (auto *AtomicCompAssignOp = dyn_cast<CompoundAssignOperator>(
3625               AtomicBody->IgnoreParenImpCasts())) {
3626         // Check for Compound Assignment Operation
3627         Op = BinaryOperator::getOpForCompoundAssignment(
3628             AtomicCompAssignOp->getOpcode());
3629         OpLoc = AtomicCompAssignOp->getOperatorLoc();
3630         E = AtomicCompAssignOp->getRHS();
3631         X = AtomicCompAssignOp->getLHS();
3632         IsXLHSInRHSPart = true;
3633       } else if (auto *AtomicBinOp = dyn_cast<BinaryOperator>(
3634                      AtomicBody->IgnoreParenImpCasts())) {
3635         // Check for Binary Operation
3636         if(checkBinaryOperation(AtomicBinOp, DiagId, NoteId))
3637           return true;
3638       } else if (auto *AtomicUnaryOp =
3639                  dyn_cast<UnaryOperator>(AtomicBody->IgnoreParenImpCasts())) {
3640         // Check for Unary Operation
3641         if (AtomicUnaryOp->isIncrementDecrementOp()) {
3642           IsPostfixUpdate = AtomicUnaryOp->isPostfix();
3643           Op = AtomicUnaryOp->isIncrementOp() ? BO_Add : BO_Sub;
3644           OpLoc = AtomicUnaryOp->getOperatorLoc();
3645           X = AtomicUnaryOp->getSubExpr();
3646           E = SemaRef.ActOnIntegerConstant(OpLoc, /*uint64_t Val=*/1).get();
3647           IsXLHSInRHSPart = true;
3648         } else {
3649           ErrorFound = NotAnUnaryIncDecExpression;
3650           ErrorLoc = AtomicUnaryOp->getExprLoc();
3651           ErrorRange = AtomicUnaryOp->getSourceRange();
3652           NoteLoc = AtomicUnaryOp->getOperatorLoc();
3653           NoteRange = SourceRange(NoteLoc, NoteLoc);
3654         }
3655       } else {
3656         ErrorFound = NotABinaryOrUnaryExpression;
3657         NoteLoc = ErrorLoc = AtomicBody->getExprLoc();
3658         NoteRange = ErrorRange = AtomicBody->getSourceRange();
3659       }
3660     } else {
3661       ErrorFound = NotAScalarType;
3662       NoteLoc = ErrorLoc = AtomicBody->getLocStart();
3663       NoteRange = ErrorRange = SourceRange(NoteLoc, NoteLoc);
3664     }
3665   } else {
3666     ErrorFound = NotAnExpression;
3667     NoteLoc = ErrorLoc = S->getLocStart();
3668     NoteRange = ErrorRange = SourceRange(NoteLoc, NoteLoc);
3669   }
3670   if (ErrorFound != NoError && DiagId != 0 && NoteId != 0) {
3671     SemaRef.Diag(ErrorLoc, DiagId) << ErrorRange;
3672     SemaRef.Diag(NoteLoc, NoteId) << ErrorFound << NoteRange;
3673     return true;
3674   } else if (SemaRef.CurContext->isDependentContext())
3675     E = X = UpdateExpr = nullptr;
3676   if (ErrorFound == NoError && E && X) {
3677     // Build an update expression of form 'OpaqueValueExpr(x) binop
3678     // OpaqueValueExpr(expr)' or 'OpaqueValueExpr(expr) binop
3679     // OpaqueValueExpr(x)' and then cast it to the type of the 'x' expression.
3680     auto *OVEX = new (SemaRef.getASTContext())
3681         OpaqueValueExpr(X->getExprLoc(), X->getType(), VK_RValue);
3682     auto *OVEExpr = new (SemaRef.getASTContext())
3683         OpaqueValueExpr(E->getExprLoc(), E->getType(), VK_RValue);
3684     auto Update =
3685         SemaRef.CreateBuiltinBinOp(OpLoc, Op, IsXLHSInRHSPart ? OVEX : OVEExpr,
3686                                    IsXLHSInRHSPart ? OVEExpr : OVEX);
3687     if (Update.isInvalid())
3688       return true;
3689     Update = SemaRef.PerformImplicitConversion(Update.get(), X->getType(),
3690                                                Sema::AA_Casting);
3691     if (Update.isInvalid())
3692       return true;
3693     UpdateExpr = Update.get();
3694   }
3695   return ErrorFound != NoError;
3696 }
3697 
3698 StmtResult Sema::ActOnOpenMPAtomicDirective(ArrayRef<OMPClause *> Clauses,
3699                                             Stmt *AStmt,
3700                                             SourceLocation StartLoc,
3701                                             SourceLocation EndLoc) {
3702   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
3703   auto CS = cast<CapturedStmt>(AStmt);
3704   // 1.2.2 OpenMP Language Terminology
3705   // Structured block - An executable statement with a single entry at the
3706   // top and a single exit at the bottom.
3707   // The point of exit cannot be a branch out of the structured block.
3708   // longjmp() and throw() must not violate the entry/exit criteria.
3709   OpenMPClauseKind AtomicKind = OMPC_unknown;
3710   SourceLocation AtomicKindLoc;
3711   for (auto *C : Clauses) {
3712     if (C->getClauseKind() == OMPC_read || C->getClauseKind() == OMPC_write ||
3713         C->getClauseKind() == OMPC_update ||
3714         C->getClauseKind() == OMPC_capture) {
3715       if (AtomicKind != OMPC_unknown) {
3716         Diag(C->getLocStart(), diag::err_omp_atomic_several_clauses)
3717             << SourceRange(C->getLocStart(), C->getLocEnd());
3718         Diag(AtomicKindLoc, diag::note_omp_atomic_previous_clause)
3719             << getOpenMPClauseName(AtomicKind);
3720       } else {
3721         AtomicKind = C->getClauseKind();
3722         AtomicKindLoc = C->getLocStart();
3723       }
3724     }
3725   }
3726 
3727   auto Body = CS->getCapturedStmt();
3728   if (auto *EWC = dyn_cast<ExprWithCleanups>(Body))
3729     Body = EWC->getSubExpr();
3730 
3731   Expr *X = nullptr;
3732   Expr *V = nullptr;
3733   Expr *E = nullptr;
3734   Expr *UE = nullptr;
3735   bool IsXLHSInRHSPart = false;
3736   bool IsPostfixUpdate = false;
3737   // OpenMP [2.12.6, atomic Construct]
3738   // In the next expressions:
3739   // * x and v (as applicable) are both l-value expressions with scalar type.
3740   // * During the execution of an atomic region, multiple syntactic
3741   // occurrences of x must designate the same storage location.
3742   // * Neither of v and expr (as applicable) may access the storage location
3743   // designated by x.
3744   // * Neither of x and expr (as applicable) may access the storage location
3745   // designated by v.
3746   // * expr is an expression with scalar type.
3747   // * binop is one of +, *, -, /, &, ^, |, <<, or >>.
3748   // * binop, binop=, ++, and -- are not overloaded operators.
3749   // * The expression x binop expr must be numerically equivalent to x binop
3750   // (expr). This requirement is satisfied if the operators in expr have
3751   // precedence greater than binop, or by using parentheses around expr or
3752   // subexpressions of expr.
3753   // * The expression expr binop x must be numerically equivalent to (expr)
3754   // binop x. This requirement is satisfied if the operators in expr have
3755   // precedence equal to or greater than binop, or by using parentheses around
3756   // expr or subexpressions of expr.
3757   // * For forms that allow multiple occurrences of x, the number of times
3758   // that x is evaluated is unspecified.
3759   if (AtomicKind == OMPC_read) {
3760     enum {
3761       NotAnExpression,
3762       NotAnAssignmentOp,
3763       NotAScalarType,
3764       NotAnLValue,
3765       NoError
3766     } ErrorFound = NoError;
3767     SourceLocation ErrorLoc, NoteLoc;
3768     SourceRange ErrorRange, NoteRange;
3769     // If clause is read:
3770     //  v = x;
3771     if (auto AtomicBody = dyn_cast<Expr>(Body)) {
3772       auto AtomicBinOp =
3773           dyn_cast<BinaryOperator>(AtomicBody->IgnoreParenImpCasts());
3774       if (AtomicBinOp && AtomicBinOp->getOpcode() == BO_Assign) {
3775         X = AtomicBinOp->getRHS()->IgnoreParenImpCasts();
3776         V = AtomicBinOp->getLHS()->IgnoreParenImpCasts();
3777         if ((X->isInstantiationDependent() || X->getType()->isScalarType()) &&
3778             (V->isInstantiationDependent() || V->getType()->isScalarType())) {
3779           if (!X->isLValue() || !V->isLValue()) {
3780             auto NotLValueExpr = X->isLValue() ? V : X;
3781             ErrorFound = NotAnLValue;
3782             ErrorLoc = AtomicBinOp->getExprLoc();
3783             ErrorRange = AtomicBinOp->getSourceRange();
3784             NoteLoc = NotLValueExpr->getExprLoc();
3785             NoteRange = NotLValueExpr->getSourceRange();
3786           }
3787         } else if (!X->isInstantiationDependent() ||
3788                    !V->isInstantiationDependent()) {
3789           auto NotScalarExpr =
3790               (X->isInstantiationDependent() || X->getType()->isScalarType())
3791                   ? V
3792                   : X;
3793           ErrorFound = NotAScalarType;
3794           ErrorLoc = AtomicBinOp->getExprLoc();
3795           ErrorRange = AtomicBinOp->getSourceRange();
3796           NoteLoc = NotScalarExpr->getExprLoc();
3797           NoteRange = NotScalarExpr->getSourceRange();
3798         }
3799       } else {
3800         ErrorFound = NotAnAssignmentOp;
3801         ErrorLoc = AtomicBody->getExprLoc();
3802         ErrorRange = AtomicBody->getSourceRange();
3803         NoteLoc = AtomicBinOp ? AtomicBinOp->getOperatorLoc()
3804                               : AtomicBody->getExprLoc();
3805         NoteRange = AtomicBinOp ? AtomicBinOp->getSourceRange()
3806                                 : AtomicBody->getSourceRange();
3807       }
3808     } else {
3809       ErrorFound = NotAnExpression;
3810       NoteLoc = ErrorLoc = Body->getLocStart();
3811       NoteRange = ErrorRange = SourceRange(NoteLoc, NoteLoc);
3812     }
3813     if (ErrorFound != NoError) {
3814       Diag(ErrorLoc, diag::err_omp_atomic_read_not_expression_statement)
3815           << ErrorRange;
3816       Diag(NoteLoc, diag::note_omp_atomic_read_write) << ErrorFound
3817                                                       << NoteRange;
3818       return StmtError();
3819     } else if (CurContext->isDependentContext())
3820       V = X = nullptr;
3821   } else if (AtomicKind == OMPC_write) {
3822     enum {
3823       NotAnExpression,
3824       NotAnAssignmentOp,
3825       NotAScalarType,
3826       NotAnLValue,
3827       NoError
3828     } ErrorFound = NoError;
3829     SourceLocation ErrorLoc, NoteLoc;
3830     SourceRange ErrorRange, NoteRange;
3831     // If clause is write:
3832     //  x = expr;
3833     if (auto AtomicBody = dyn_cast<Expr>(Body)) {
3834       auto AtomicBinOp =
3835           dyn_cast<BinaryOperator>(AtomicBody->IgnoreParenImpCasts());
3836       if (AtomicBinOp && AtomicBinOp->getOpcode() == BO_Assign) {
3837         X = AtomicBinOp->getLHS();
3838         E = AtomicBinOp->getRHS();
3839         if ((X->isInstantiationDependent() || X->getType()->isScalarType()) &&
3840             (E->isInstantiationDependent() || E->getType()->isScalarType())) {
3841           if (!X->isLValue()) {
3842             ErrorFound = NotAnLValue;
3843             ErrorLoc = AtomicBinOp->getExprLoc();
3844             ErrorRange = AtomicBinOp->getSourceRange();
3845             NoteLoc = X->getExprLoc();
3846             NoteRange = X->getSourceRange();
3847           }
3848         } else if (!X->isInstantiationDependent() ||
3849                    !E->isInstantiationDependent()) {
3850           auto NotScalarExpr =
3851               (X->isInstantiationDependent() || X->getType()->isScalarType())
3852                   ? E
3853                   : X;
3854           ErrorFound = NotAScalarType;
3855           ErrorLoc = AtomicBinOp->getExprLoc();
3856           ErrorRange = AtomicBinOp->getSourceRange();
3857           NoteLoc = NotScalarExpr->getExprLoc();
3858           NoteRange = NotScalarExpr->getSourceRange();
3859         }
3860       } else {
3861         ErrorFound = NotAnAssignmentOp;
3862         ErrorLoc = AtomicBody->getExprLoc();
3863         ErrorRange = AtomicBody->getSourceRange();
3864         NoteLoc = AtomicBinOp ? AtomicBinOp->getOperatorLoc()
3865                               : AtomicBody->getExprLoc();
3866         NoteRange = AtomicBinOp ? AtomicBinOp->getSourceRange()
3867                                 : AtomicBody->getSourceRange();
3868       }
3869     } else {
3870       ErrorFound = NotAnExpression;
3871       NoteLoc = ErrorLoc = Body->getLocStart();
3872       NoteRange = ErrorRange = SourceRange(NoteLoc, NoteLoc);
3873     }
3874     if (ErrorFound != NoError) {
3875       Diag(ErrorLoc, diag::err_omp_atomic_write_not_expression_statement)
3876           << ErrorRange;
3877       Diag(NoteLoc, diag::note_omp_atomic_read_write) << ErrorFound
3878                                                       << NoteRange;
3879       return StmtError();
3880     } else if (CurContext->isDependentContext())
3881       E = X = nullptr;
3882   } else if (AtomicKind == OMPC_update || AtomicKind == OMPC_unknown) {
3883     // If clause is update:
3884     //  x++;
3885     //  x--;
3886     //  ++x;
3887     //  --x;
3888     //  x binop= expr;
3889     //  x = x binop expr;
3890     //  x = expr binop x;
3891     OpenMPAtomicUpdateChecker Checker(*this);
3892     if (Checker.checkStatement(
3893             Body, (AtomicKind == OMPC_update)
3894                       ? diag::err_omp_atomic_update_not_expression_statement
3895                       : diag::err_omp_atomic_not_expression_statement,
3896             diag::note_omp_atomic_update))
3897       return StmtError();
3898     if (!CurContext->isDependentContext()) {
3899       E = Checker.getExpr();
3900       X = Checker.getX();
3901       UE = Checker.getUpdateExpr();
3902       IsXLHSInRHSPart = Checker.isXLHSInRHSPart();
3903     }
3904   } else if (AtomicKind == OMPC_capture) {
3905     enum {
3906       NotAnAssignmentOp,
3907       NotACompoundStatement,
3908       NotTwoSubstatements,
3909       NotASpecificExpression,
3910       NoError
3911     } ErrorFound = NoError;
3912     SourceLocation ErrorLoc, NoteLoc;
3913     SourceRange ErrorRange, NoteRange;
3914     if (auto *AtomicBody = dyn_cast<Expr>(Body)) {
3915       // If clause is a capture:
3916       //  v = x++;
3917       //  v = x--;
3918       //  v = ++x;
3919       //  v = --x;
3920       //  v = x binop= expr;
3921       //  v = x = x binop expr;
3922       //  v = x = expr binop x;
3923       auto *AtomicBinOp =
3924           dyn_cast<BinaryOperator>(AtomicBody->IgnoreParenImpCasts());
3925       if (AtomicBinOp && AtomicBinOp->getOpcode() == BO_Assign) {
3926         V = AtomicBinOp->getLHS();
3927         Body = AtomicBinOp->getRHS()->IgnoreParenImpCasts();
3928         OpenMPAtomicUpdateChecker Checker(*this);
3929         if (Checker.checkStatement(
3930                 Body, diag::err_omp_atomic_capture_not_expression_statement,
3931                 diag::note_omp_atomic_update))
3932           return StmtError();
3933         E = Checker.getExpr();
3934         X = Checker.getX();
3935         UE = Checker.getUpdateExpr();
3936         IsXLHSInRHSPart = Checker.isXLHSInRHSPart();
3937         IsPostfixUpdate = Checker.isPostfixUpdate();
3938       } else {
3939         ErrorLoc = AtomicBody->getExprLoc();
3940         ErrorRange = AtomicBody->getSourceRange();
3941         NoteLoc = AtomicBinOp ? AtomicBinOp->getOperatorLoc()
3942                               : AtomicBody->getExprLoc();
3943         NoteRange = AtomicBinOp ? AtomicBinOp->getSourceRange()
3944                                 : AtomicBody->getSourceRange();
3945         ErrorFound = NotAnAssignmentOp;
3946       }
3947       if (ErrorFound != NoError) {
3948         Diag(ErrorLoc, diag::err_omp_atomic_capture_not_expression_statement)
3949             << ErrorRange;
3950         Diag(NoteLoc, diag::note_omp_atomic_capture) << ErrorFound << NoteRange;
3951         return StmtError();
3952       } else if (CurContext->isDependentContext()) {
3953         UE = V = E = X = nullptr;
3954       }
3955     } else {
3956       // If clause is a capture:
3957       //  { v = x; x = expr; }
3958       //  { v = x; x++; }
3959       //  { v = x; x--; }
3960       //  { v = x; ++x; }
3961       //  { v = x; --x; }
3962       //  { v = x; x binop= expr; }
3963       //  { v = x; x = x binop expr; }
3964       //  { v = x; x = expr binop x; }
3965       //  { x++; v = x; }
3966       //  { x--; v = x; }
3967       //  { ++x; v = x; }
3968       //  { --x; v = x; }
3969       //  { x binop= expr; v = x; }
3970       //  { x = x binop expr; v = x; }
3971       //  { x = expr binop x; v = x; }
3972       if (auto *CS = dyn_cast<CompoundStmt>(Body)) {
3973         // Check that this is { expr1; expr2; }
3974         if (CS->size() == 2) {
3975           auto *First = CS->body_front();
3976           auto *Second = CS->body_back();
3977           if (auto *EWC = dyn_cast<ExprWithCleanups>(First))
3978             First = EWC->getSubExpr()->IgnoreParenImpCasts();
3979           if (auto *EWC = dyn_cast<ExprWithCleanups>(Second))
3980             Second = EWC->getSubExpr()->IgnoreParenImpCasts();
3981           // Need to find what subexpression is 'v' and what is 'x'.
3982           OpenMPAtomicUpdateChecker Checker(*this);
3983           bool IsUpdateExprFound = !Checker.checkStatement(Second);
3984           BinaryOperator *BinOp = nullptr;
3985           if (IsUpdateExprFound) {
3986             BinOp = dyn_cast<BinaryOperator>(First);
3987             IsUpdateExprFound = BinOp && BinOp->getOpcode() == BO_Assign;
3988           }
3989           if (IsUpdateExprFound && !CurContext->isDependentContext()) {
3990             //  { v = x; x++; }
3991             //  { v = x; x--; }
3992             //  { v = x; ++x; }
3993             //  { v = x; --x; }
3994             //  { v = x; x binop= expr; }
3995             //  { v = x; x = x binop expr; }
3996             //  { v = x; x = expr binop x; }
3997             // Check that the first expression has form v = x.
3998             auto *PossibleX = BinOp->getRHS()->IgnoreParenImpCasts();
3999             llvm::FoldingSetNodeID XId, PossibleXId;
4000             Checker.getX()->Profile(XId, Context, /*Canonical=*/true);
4001             PossibleX->Profile(PossibleXId, Context, /*Canonical=*/true);
4002             IsUpdateExprFound = XId == PossibleXId;
4003             if (IsUpdateExprFound) {
4004               V = BinOp->getLHS();
4005               X = Checker.getX();
4006               E = Checker.getExpr();
4007               UE = Checker.getUpdateExpr();
4008               IsXLHSInRHSPart = Checker.isXLHSInRHSPart();
4009               IsPostfixUpdate = true;
4010             }
4011           }
4012           if (!IsUpdateExprFound) {
4013             IsUpdateExprFound = !Checker.checkStatement(First);
4014             BinOp = nullptr;
4015             if (IsUpdateExprFound) {
4016               BinOp = dyn_cast<BinaryOperator>(Second);
4017               IsUpdateExprFound = BinOp && BinOp->getOpcode() == BO_Assign;
4018             }
4019             if (IsUpdateExprFound && !CurContext->isDependentContext()) {
4020               //  { x++; v = x; }
4021               //  { x--; v = x; }
4022               //  { ++x; v = x; }
4023               //  { --x; v = x; }
4024               //  { x binop= expr; v = x; }
4025               //  { x = x binop expr; v = x; }
4026               //  { x = expr binop x; v = x; }
4027               // Check that the second expression has form v = x.
4028               auto *PossibleX = BinOp->getRHS()->IgnoreParenImpCasts();
4029               llvm::FoldingSetNodeID XId, PossibleXId;
4030               Checker.getX()->Profile(XId, Context, /*Canonical=*/true);
4031               PossibleX->Profile(PossibleXId, Context, /*Canonical=*/true);
4032               IsUpdateExprFound = XId == PossibleXId;
4033               if (IsUpdateExprFound) {
4034                 V = BinOp->getLHS();
4035                 X = Checker.getX();
4036                 E = Checker.getExpr();
4037                 UE = Checker.getUpdateExpr();
4038                 IsXLHSInRHSPart = Checker.isXLHSInRHSPart();
4039                 IsPostfixUpdate = false;
4040               }
4041             }
4042           }
4043           if (!IsUpdateExprFound) {
4044             //  { v = x; x = expr; }
4045             auto *FirstBinOp = dyn_cast<BinaryOperator>(First);
4046             if (!FirstBinOp || FirstBinOp->getOpcode() != BO_Assign) {
4047               ErrorFound = NotAnAssignmentOp;
4048               NoteLoc = ErrorLoc = FirstBinOp ? FirstBinOp->getOperatorLoc()
4049                                               : First->getLocStart();
4050               NoteRange = ErrorRange = FirstBinOp
4051                                            ? FirstBinOp->getSourceRange()
4052                                            : SourceRange(ErrorLoc, ErrorLoc);
4053             } else {
4054               auto *SecondBinOp = dyn_cast<BinaryOperator>(Second);
4055               if (!SecondBinOp || SecondBinOp->getOpcode() != BO_Assign) {
4056                 ErrorFound = NotAnAssignmentOp;
4057                 NoteLoc = ErrorLoc = SecondBinOp ? SecondBinOp->getOperatorLoc()
4058                                                  : Second->getLocStart();
4059                 NoteRange = ErrorRange = SecondBinOp
4060                                              ? SecondBinOp->getSourceRange()
4061                                              : SourceRange(ErrorLoc, ErrorLoc);
4062               } else {
4063                 auto *PossibleXRHSInFirst =
4064                     FirstBinOp->getRHS()->IgnoreParenImpCasts();
4065                 auto *PossibleXLHSInSecond =
4066                     SecondBinOp->getLHS()->IgnoreParenImpCasts();
4067                 llvm::FoldingSetNodeID X1Id, X2Id;
4068                 PossibleXRHSInFirst->Profile(X1Id, Context, /*Canonical=*/true);
4069                 PossibleXLHSInSecond->Profile(X2Id, Context,
4070                                               /*Canonical=*/true);
4071                 IsUpdateExprFound = X1Id == X2Id;
4072                 if (IsUpdateExprFound) {
4073                   V = FirstBinOp->getLHS();
4074                   X = SecondBinOp->getLHS();
4075                   E = SecondBinOp->getRHS();
4076                   UE = nullptr;
4077                   IsXLHSInRHSPart = false;
4078                   IsPostfixUpdate = true;
4079                 } else {
4080                   ErrorFound = NotASpecificExpression;
4081                   ErrorLoc = FirstBinOp->getExprLoc();
4082                   ErrorRange = FirstBinOp->getSourceRange();
4083                   NoteLoc = SecondBinOp->getLHS()->getExprLoc();
4084                   NoteRange = SecondBinOp->getRHS()->getSourceRange();
4085                 }
4086               }
4087             }
4088           }
4089         } else {
4090           NoteLoc = ErrorLoc = Body->getLocStart();
4091           NoteRange = ErrorRange =
4092               SourceRange(Body->getLocStart(), Body->getLocStart());
4093           ErrorFound = NotTwoSubstatements;
4094         }
4095       } else {
4096         NoteLoc = ErrorLoc = Body->getLocStart();
4097         NoteRange = ErrorRange =
4098             SourceRange(Body->getLocStart(), Body->getLocStart());
4099         ErrorFound = NotACompoundStatement;
4100       }
4101       if (ErrorFound != NoError) {
4102         Diag(ErrorLoc, diag::err_omp_atomic_capture_not_compound_statement)
4103             << ErrorRange;
4104         Diag(NoteLoc, diag::note_omp_atomic_capture) << ErrorFound << NoteRange;
4105         return StmtError();
4106       } else if (CurContext->isDependentContext()) {
4107         UE = V = E = X = nullptr;
4108       }
4109     }
4110   }
4111 
4112   getCurFunction()->setHasBranchProtectedScope();
4113 
4114   return OMPAtomicDirective::Create(Context, StartLoc, EndLoc, Clauses, AStmt,
4115                                     X, V, E, UE, IsXLHSInRHSPart,
4116                                     IsPostfixUpdate);
4117 }
4118 
4119 StmtResult Sema::ActOnOpenMPTargetDirective(ArrayRef<OMPClause *> Clauses,
4120                                             Stmt *AStmt,
4121                                             SourceLocation StartLoc,
4122                                             SourceLocation EndLoc) {
4123   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
4124 
4125   // OpenMP [2.16, Nesting of Regions]
4126   // If specified, a teams construct must be contained within a target
4127   // construct. That target construct must contain no statements or directives
4128   // outside of the teams construct.
4129   if (DSAStack->hasInnerTeamsRegion()) {
4130     auto S = AStmt->IgnoreContainers(/*IgnoreCaptured*/ true);
4131     bool OMPTeamsFound = true;
4132     if (auto *CS = dyn_cast<CompoundStmt>(S)) {
4133       auto I = CS->body_begin();
4134       while (I != CS->body_end()) {
4135         auto OED = dyn_cast<OMPExecutableDirective>(*I);
4136         if (!OED || !isOpenMPTeamsDirective(OED->getDirectiveKind())) {
4137           OMPTeamsFound = false;
4138           break;
4139         }
4140         ++I;
4141       }
4142       assert(I != CS->body_end() && "Not found statement");
4143       S = *I;
4144     }
4145     if (!OMPTeamsFound) {
4146       Diag(StartLoc, diag::err_omp_target_contains_not_only_teams);
4147       Diag(DSAStack->getInnerTeamsRegionLoc(),
4148            diag::note_omp_nested_teams_construct_here);
4149       Diag(S->getLocStart(), diag::note_omp_nested_statement_here)
4150           << isa<OMPExecutableDirective>(S);
4151       return StmtError();
4152     }
4153   }
4154 
4155   getCurFunction()->setHasBranchProtectedScope();
4156 
4157   return OMPTargetDirective::Create(Context, StartLoc, EndLoc, Clauses, AStmt);
4158 }
4159 
4160 StmtResult Sema::ActOnOpenMPTeamsDirective(ArrayRef<OMPClause *> Clauses,
4161                                            Stmt *AStmt, SourceLocation StartLoc,
4162                                            SourceLocation EndLoc) {
4163   assert(AStmt && isa<CapturedStmt>(AStmt) && "Captured statement expected");
4164   CapturedStmt *CS = cast<CapturedStmt>(AStmt);
4165   // 1.2.2 OpenMP Language Terminology
4166   // Structured block - An executable statement with a single entry at the
4167   // top and a single exit at the bottom.
4168   // The point of exit cannot be a branch out of the structured block.
4169   // longjmp() and throw() must not violate the entry/exit criteria.
4170   CS->getCapturedDecl()->setNothrow();
4171 
4172   getCurFunction()->setHasBranchProtectedScope();
4173 
4174   return OMPTeamsDirective::Create(Context, StartLoc, EndLoc, Clauses, AStmt);
4175 }
4176 
4177 OMPClause *Sema::ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind, Expr *Expr,
4178                                              SourceLocation StartLoc,
4179                                              SourceLocation LParenLoc,
4180                                              SourceLocation EndLoc) {
4181   OMPClause *Res = nullptr;
4182   switch (Kind) {
4183   case OMPC_if:
4184     Res = ActOnOpenMPIfClause(Expr, StartLoc, LParenLoc, EndLoc);
4185     break;
4186   case OMPC_final:
4187     Res = ActOnOpenMPFinalClause(Expr, StartLoc, LParenLoc, EndLoc);
4188     break;
4189   case OMPC_num_threads:
4190     Res = ActOnOpenMPNumThreadsClause(Expr, StartLoc, LParenLoc, EndLoc);
4191     break;
4192   case OMPC_safelen:
4193     Res = ActOnOpenMPSafelenClause(Expr, StartLoc, LParenLoc, EndLoc);
4194     break;
4195   case OMPC_collapse:
4196     Res = ActOnOpenMPCollapseClause(Expr, StartLoc, LParenLoc, EndLoc);
4197     break;
4198   case OMPC_default:
4199   case OMPC_proc_bind:
4200   case OMPC_schedule:
4201   case OMPC_private:
4202   case OMPC_firstprivate:
4203   case OMPC_lastprivate:
4204   case OMPC_shared:
4205   case OMPC_reduction:
4206   case OMPC_linear:
4207   case OMPC_aligned:
4208   case OMPC_copyin:
4209   case OMPC_copyprivate:
4210   case OMPC_ordered:
4211   case OMPC_nowait:
4212   case OMPC_untied:
4213   case OMPC_mergeable:
4214   case OMPC_threadprivate:
4215   case OMPC_flush:
4216   case OMPC_read:
4217   case OMPC_write:
4218   case OMPC_update:
4219   case OMPC_capture:
4220   case OMPC_seq_cst:
4221   case OMPC_unknown:
4222     llvm_unreachable("Clause is not allowed.");
4223   }
4224   return Res;
4225 }
4226 
4227 OMPClause *Sema::ActOnOpenMPIfClause(Expr *Condition, SourceLocation StartLoc,
4228                                      SourceLocation LParenLoc,
4229                                      SourceLocation EndLoc) {
4230   Expr *ValExpr = Condition;
4231   if (!Condition->isValueDependent() && !Condition->isTypeDependent() &&
4232       !Condition->isInstantiationDependent() &&
4233       !Condition->containsUnexpandedParameterPack()) {
4234     ExprResult Val = ActOnBooleanCondition(DSAStack->getCurScope(),
4235                                            Condition->getExprLoc(), Condition);
4236     if (Val.isInvalid())
4237       return nullptr;
4238 
4239     ValExpr = Val.get();
4240   }
4241 
4242   return new (Context) OMPIfClause(ValExpr, StartLoc, LParenLoc, EndLoc);
4243 }
4244 
4245 OMPClause *Sema::ActOnOpenMPFinalClause(Expr *Condition,
4246                                         SourceLocation StartLoc,
4247                                         SourceLocation LParenLoc,
4248                                         SourceLocation EndLoc) {
4249   Expr *ValExpr = Condition;
4250   if (!Condition->isValueDependent() && !Condition->isTypeDependent() &&
4251       !Condition->isInstantiationDependent() &&
4252       !Condition->containsUnexpandedParameterPack()) {
4253     ExprResult Val = ActOnBooleanCondition(DSAStack->getCurScope(),
4254                                            Condition->getExprLoc(), Condition);
4255     if (Val.isInvalid())
4256       return nullptr;
4257 
4258     ValExpr = Val.get();
4259   }
4260 
4261   return new (Context) OMPFinalClause(ValExpr, StartLoc, LParenLoc, EndLoc);
4262 }
4263 ExprResult Sema::PerformOpenMPImplicitIntegerConversion(SourceLocation Loc,
4264                                                         Expr *Op) {
4265   if (!Op)
4266     return ExprError();
4267 
4268   class IntConvertDiagnoser : public ICEConvertDiagnoser {
4269   public:
4270     IntConvertDiagnoser()
4271         : ICEConvertDiagnoser(/*AllowScopedEnumerations*/ false, false, true) {}
4272     SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc,
4273                                          QualType T) override {
4274       return S.Diag(Loc, diag::err_omp_not_integral) << T;
4275     }
4276     SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc,
4277                                              QualType T) override {
4278       return S.Diag(Loc, diag::err_omp_incomplete_type) << T;
4279     }
4280     SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc,
4281                                                QualType T,
4282                                                QualType ConvTy) override {
4283       return S.Diag(Loc, diag::err_omp_explicit_conversion) << T << ConvTy;
4284     }
4285     SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv,
4286                                            QualType ConvTy) override {
4287       return S.Diag(Conv->getLocation(), diag::note_omp_conversion_here)
4288              << ConvTy->isEnumeralType() << ConvTy;
4289     }
4290     SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc,
4291                                             QualType T) override {
4292       return S.Diag(Loc, diag::err_omp_ambiguous_conversion) << T;
4293     }
4294     SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv,
4295                                         QualType ConvTy) override {
4296       return S.Diag(Conv->getLocation(), diag::note_omp_conversion_here)
4297              << ConvTy->isEnumeralType() << ConvTy;
4298     }
4299     SemaDiagnosticBuilder diagnoseConversion(Sema &, SourceLocation, QualType,
4300                                              QualType) override {
4301       llvm_unreachable("conversion functions are permitted");
4302     }
4303   } ConvertDiagnoser;
4304   return PerformContextualImplicitConversion(Loc, Op, ConvertDiagnoser);
4305 }
4306 
4307 OMPClause *Sema::ActOnOpenMPNumThreadsClause(Expr *NumThreads,
4308                                              SourceLocation StartLoc,
4309                                              SourceLocation LParenLoc,
4310                                              SourceLocation EndLoc) {
4311   Expr *ValExpr = NumThreads;
4312   if (!NumThreads->isValueDependent() && !NumThreads->isTypeDependent() &&
4313       !NumThreads->containsUnexpandedParameterPack()) {
4314     SourceLocation NumThreadsLoc = NumThreads->getLocStart();
4315     ExprResult Val =
4316         PerformOpenMPImplicitIntegerConversion(NumThreadsLoc, NumThreads);
4317     if (Val.isInvalid())
4318       return nullptr;
4319 
4320     ValExpr = Val.get();
4321 
4322     // OpenMP [2.5, Restrictions]
4323     //  The num_threads expression must evaluate to a positive integer value.
4324     llvm::APSInt Result;
4325     if (ValExpr->isIntegerConstantExpr(Result, Context) && Result.isSigned() &&
4326         !Result.isStrictlyPositive()) {
4327       Diag(NumThreadsLoc, diag::err_omp_negative_expression_in_clause)
4328           << "num_threads" << NumThreads->getSourceRange();
4329       return nullptr;
4330     }
4331   }
4332 
4333   return new (Context)
4334       OMPNumThreadsClause(ValExpr, StartLoc, LParenLoc, EndLoc);
4335 }
4336 
4337 ExprResult Sema::VerifyPositiveIntegerConstantInClause(Expr *E,
4338                                                        OpenMPClauseKind CKind) {
4339   if (!E)
4340     return ExprError();
4341   if (E->isValueDependent() || E->isTypeDependent() ||
4342       E->isInstantiationDependent() || E->containsUnexpandedParameterPack())
4343     return E;
4344   llvm::APSInt Result;
4345   ExprResult ICE = VerifyIntegerConstantExpression(E, &Result);
4346   if (ICE.isInvalid())
4347     return ExprError();
4348   if (!Result.isStrictlyPositive()) {
4349     Diag(E->getExprLoc(), diag::err_omp_negative_expression_in_clause)
4350         << getOpenMPClauseName(CKind) << E->getSourceRange();
4351     return ExprError();
4352   }
4353   if (CKind == OMPC_aligned && !Result.isPowerOf2()) {
4354     Diag(E->getExprLoc(), diag::warn_omp_alignment_not_power_of_two)
4355         << E->getSourceRange();
4356     return ExprError();
4357   }
4358   if (CKind == OMPC_collapse) {
4359     DSAStack->setCollapseNumber(Result.getExtValue());
4360   }
4361   return ICE;
4362 }
4363 
4364 OMPClause *Sema::ActOnOpenMPSafelenClause(Expr *Len, SourceLocation StartLoc,
4365                                           SourceLocation LParenLoc,
4366                                           SourceLocation EndLoc) {
4367   // OpenMP [2.8.1, simd construct, Description]
4368   // The parameter of the safelen clause must be a constant
4369   // positive integer expression.
4370   ExprResult Safelen = VerifyPositiveIntegerConstantInClause(Len, OMPC_safelen);
4371   if (Safelen.isInvalid())
4372     return nullptr;
4373   return new (Context)
4374       OMPSafelenClause(Safelen.get(), StartLoc, LParenLoc, EndLoc);
4375 }
4376 
4377 OMPClause *Sema::ActOnOpenMPCollapseClause(Expr *NumForLoops,
4378                                            SourceLocation StartLoc,
4379                                            SourceLocation LParenLoc,
4380                                            SourceLocation EndLoc) {
4381   // OpenMP [2.7.1, loop construct, Description]
4382   // OpenMP [2.8.1, simd construct, Description]
4383   // OpenMP [2.9.6, distribute construct, Description]
4384   // The parameter of the collapse clause must be a constant
4385   // positive integer expression.
4386   ExprResult NumForLoopsResult =
4387       VerifyPositiveIntegerConstantInClause(NumForLoops, OMPC_collapse);
4388   if (NumForLoopsResult.isInvalid())
4389     return nullptr;
4390   return new (Context)
4391       OMPCollapseClause(NumForLoopsResult.get(), StartLoc, LParenLoc, EndLoc);
4392 }
4393 
4394 OMPClause *Sema::ActOnOpenMPSimpleClause(
4395     OpenMPClauseKind Kind, unsigned Argument, SourceLocation ArgumentLoc,
4396     SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation EndLoc) {
4397   OMPClause *Res = nullptr;
4398   switch (Kind) {
4399   case OMPC_default:
4400     Res =
4401         ActOnOpenMPDefaultClause(static_cast<OpenMPDefaultClauseKind>(Argument),
4402                                  ArgumentLoc, StartLoc, LParenLoc, EndLoc);
4403     break;
4404   case OMPC_proc_bind:
4405     Res = ActOnOpenMPProcBindClause(
4406         static_cast<OpenMPProcBindClauseKind>(Argument), ArgumentLoc, StartLoc,
4407         LParenLoc, EndLoc);
4408     break;
4409   case OMPC_if:
4410   case OMPC_final:
4411   case OMPC_num_threads:
4412   case OMPC_safelen:
4413   case OMPC_collapse:
4414   case OMPC_schedule:
4415   case OMPC_private:
4416   case OMPC_firstprivate:
4417   case OMPC_lastprivate:
4418   case OMPC_shared:
4419   case OMPC_reduction:
4420   case OMPC_linear:
4421   case OMPC_aligned:
4422   case OMPC_copyin:
4423   case OMPC_copyprivate:
4424   case OMPC_ordered:
4425   case OMPC_nowait:
4426   case OMPC_untied:
4427   case OMPC_mergeable:
4428   case OMPC_threadprivate:
4429   case OMPC_flush:
4430   case OMPC_read:
4431   case OMPC_write:
4432   case OMPC_update:
4433   case OMPC_capture:
4434   case OMPC_seq_cst:
4435   case OMPC_unknown:
4436     llvm_unreachable("Clause is not allowed.");
4437   }
4438   return Res;
4439 }
4440 
4441 OMPClause *Sema::ActOnOpenMPDefaultClause(OpenMPDefaultClauseKind Kind,
4442                                           SourceLocation KindKwLoc,
4443                                           SourceLocation StartLoc,
4444                                           SourceLocation LParenLoc,
4445                                           SourceLocation EndLoc) {
4446   if (Kind == OMPC_DEFAULT_unknown) {
4447     std::string Values;
4448     static_assert(OMPC_DEFAULT_unknown > 0,
4449                   "OMPC_DEFAULT_unknown not greater than 0");
4450     std::string Sep(", ");
4451     for (unsigned i = 0; i < OMPC_DEFAULT_unknown; ++i) {
4452       Values += "'";
4453       Values += getOpenMPSimpleClauseTypeName(OMPC_default, i);
4454       Values += "'";
4455       switch (i) {
4456       case OMPC_DEFAULT_unknown - 2:
4457         Values += " or ";
4458         break;
4459       case OMPC_DEFAULT_unknown - 1:
4460         break;
4461       default:
4462         Values += Sep;
4463         break;
4464       }
4465     }
4466     Diag(KindKwLoc, diag::err_omp_unexpected_clause_value)
4467         << Values << getOpenMPClauseName(OMPC_default);
4468     return nullptr;
4469   }
4470   switch (Kind) {
4471   case OMPC_DEFAULT_none:
4472     DSAStack->setDefaultDSANone(KindKwLoc);
4473     break;
4474   case OMPC_DEFAULT_shared:
4475     DSAStack->setDefaultDSAShared(KindKwLoc);
4476     break;
4477   case OMPC_DEFAULT_unknown:
4478     llvm_unreachable("Clause kind is not allowed.");
4479     break;
4480   }
4481   return new (Context)
4482       OMPDefaultClause(Kind, KindKwLoc, StartLoc, LParenLoc, EndLoc);
4483 }
4484 
4485 OMPClause *Sema::ActOnOpenMPProcBindClause(OpenMPProcBindClauseKind Kind,
4486                                            SourceLocation KindKwLoc,
4487                                            SourceLocation StartLoc,
4488                                            SourceLocation LParenLoc,
4489                                            SourceLocation EndLoc) {
4490   if (Kind == OMPC_PROC_BIND_unknown) {
4491     std::string Values;
4492     std::string Sep(", ");
4493     for (unsigned i = 0; i < OMPC_PROC_BIND_unknown; ++i) {
4494       Values += "'";
4495       Values += getOpenMPSimpleClauseTypeName(OMPC_proc_bind, i);
4496       Values += "'";
4497       switch (i) {
4498       case OMPC_PROC_BIND_unknown - 2:
4499         Values += " or ";
4500         break;
4501       case OMPC_PROC_BIND_unknown - 1:
4502         break;
4503       default:
4504         Values += Sep;
4505         break;
4506       }
4507     }
4508     Diag(KindKwLoc, diag::err_omp_unexpected_clause_value)
4509         << Values << getOpenMPClauseName(OMPC_proc_bind);
4510     return nullptr;
4511   }
4512   return new (Context)
4513       OMPProcBindClause(Kind, KindKwLoc, StartLoc, LParenLoc, EndLoc);
4514 }
4515 
4516 OMPClause *Sema::ActOnOpenMPSingleExprWithArgClause(
4517     OpenMPClauseKind Kind, unsigned Argument, Expr *Expr,
4518     SourceLocation StartLoc, SourceLocation LParenLoc,
4519     SourceLocation ArgumentLoc, SourceLocation CommaLoc,
4520     SourceLocation EndLoc) {
4521   OMPClause *Res = nullptr;
4522   switch (Kind) {
4523   case OMPC_schedule:
4524     Res = ActOnOpenMPScheduleClause(
4525         static_cast<OpenMPScheduleClauseKind>(Argument), Expr, StartLoc,
4526         LParenLoc, ArgumentLoc, CommaLoc, EndLoc);
4527     break;
4528   case OMPC_if:
4529   case OMPC_final:
4530   case OMPC_num_threads:
4531   case OMPC_safelen:
4532   case OMPC_collapse:
4533   case OMPC_default:
4534   case OMPC_proc_bind:
4535   case OMPC_private:
4536   case OMPC_firstprivate:
4537   case OMPC_lastprivate:
4538   case OMPC_shared:
4539   case OMPC_reduction:
4540   case OMPC_linear:
4541   case OMPC_aligned:
4542   case OMPC_copyin:
4543   case OMPC_copyprivate:
4544   case OMPC_ordered:
4545   case OMPC_nowait:
4546   case OMPC_untied:
4547   case OMPC_mergeable:
4548   case OMPC_threadprivate:
4549   case OMPC_flush:
4550   case OMPC_read:
4551   case OMPC_write:
4552   case OMPC_update:
4553   case OMPC_capture:
4554   case OMPC_seq_cst:
4555   case OMPC_unknown:
4556     llvm_unreachable("Clause is not allowed.");
4557   }
4558   return Res;
4559 }
4560 
4561 OMPClause *Sema::ActOnOpenMPScheduleClause(
4562     OpenMPScheduleClauseKind Kind, Expr *ChunkSize, SourceLocation StartLoc,
4563     SourceLocation LParenLoc, SourceLocation KindLoc, SourceLocation CommaLoc,
4564     SourceLocation EndLoc) {
4565   if (Kind == OMPC_SCHEDULE_unknown) {
4566     std::string Values;
4567     std::string Sep(", ");
4568     for (unsigned i = 0; i < OMPC_SCHEDULE_unknown; ++i) {
4569       Values += "'";
4570       Values += getOpenMPSimpleClauseTypeName(OMPC_schedule, i);
4571       Values += "'";
4572       switch (i) {
4573       case OMPC_SCHEDULE_unknown - 2:
4574         Values += " or ";
4575         break;
4576       case OMPC_SCHEDULE_unknown - 1:
4577         break;
4578       default:
4579         Values += Sep;
4580         break;
4581       }
4582     }
4583     Diag(KindLoc, diag::err_omp_unexpected_clause_value)
4584         << Values << getOpenMPClauseName(OMPC_schedule);
4585     return nullptr;
4586   }
4587   Expr *ValExpr = ChunkSize;
4588   Expr *HelperValExpr = nullptr;
4589   if (ChunkSize) {
4590     if (!ChunkSize->isValueDependent() && !ChunkSize->isTypeDependent() &&
4591         !ChunkSize->isInstantiationDependent() &&
4592         !ChunkSize->containsUnexpandedParameterPack()) {
4593       SourceLocation ChunkSizeLoc = ChunkSize->getLocStart();
4594       ExprResult Val =
4595           PerformOpenMPImplicitIntegerConversion(ChunkSizeLoc, ChunkSize);
4596       if (Val.isInvalid())
4597         return nullptr;
4598 
4599       ValExpr = Val.get();
4600 
4601       // OpenMP [2.7.1, Restrictions]
4602       //  chunk_size must be a loop invariant integer expression with a positive
4603       //  value.
4604       llvm::APSInt Result;
4605       if (ValExpr->isIntegerConstantExpr(Result, Context)) {
4606         if (Result.isSigned() && !Result.isStrictlyPositive()) {
4607           Diag(ChunkSizeLoc, diag::err_omp_negative_expression_in_clause)
4608               << "schedule" << ChunkSize->getSourceRange();
4609           return nullptr;
4610         }
4611       } else if (isParallelOrTaskRegion(DSAStack->getCurrentDirective())) {
4612         auto *ImpVar = buildVarDecl(*this, ChunkSize->getExprLoc(),
4613                                     ChunkSize->getType(), ".chunk.");
4614         auto *ImpVarRef = buildDeclRefExpr(*this, ImpVar, ChunkSize->getType(),
4615                                            ChunkSize->getExprLoc(),
4616                                            /*RefersToCapture=*/true);
4617         HelperValExpr = ImpVarRef;
4618       }
4619     }
4620   }
4621 
4622   return new (Context) OMPScheduleClause(StartLoc, LParenLoc, KindLoc, CommaLoc,
4623                                          EndLoc, Kind, ValExpr, HelperValExpr);
4624 }
4625 
4626 OMPClause *Sema::ActOnOpenMPClause(OpenMPClauseKind Kind,
4627                                    SourceLocation StartLoc,
4628                                    SourceLocation EndLoc) {
4629   OMPClause *Res = nullptr;
4630   switch (Kind) {
4631   case OMPC_ordered:
4632     Res = ActOnOpenMPOrderedClause(StartLoc, EndLoc);
4633     break;
4634   case OMPC_nowait:
4635     Res = ActOnOpenMPNowaitClause(StartLoc, EndLoc);
4636     break;
4637   case OMPC_untied:
4638     Res = ActOnOpenMPUntiedClause(StartLoc, EndLoc);
4639     break;
4640   case OMPC_mergeable:
4641     Res = ActOnOpenMPMergeableClause(StartLoc, EndLoc);
4642     break;
4643   case OMPC_read:
4644     Res = ActOnOpenMPReadClause(StartLoc, EndLoc);
4645     break;
4646   case OMPC_write:
4647     Res = ActOnOpenMPWriteClause(StartLoc, EndLoc);
4648     break;
4649   case OMPC_update:
4650     Res = ActOnOpenMPUpdateClause(StartLoc, EndLoc);
4651     break;
4652   case OMPC_capture:
4653     Res = ActOnOpenMPCaptureClause(StartLoc, EndLoc);
4654     break;
4655   case OMPC_seq_cst:
4656     Res = ActOnOpenMPSeqCstClause(StartLoc, EndLoc);
4657     break;
4658   case OMPC_if:
4659   case OMPC_final:
4660   case OMPC_num_threads:
4661   case OMPC_safelen:
4662   case OMPC_collapse:
4663   case OMPC_schedule:
4664   case OMPC_private:
4665   case OMPC_firstprivate:
4666   case OMPC_lastprivate:
4667   case OMPC_shared:
4668   case OMPC_reduction:
4669   case OMPC_linear:
4670   case OMPC_aligned:
4671   case OMPC_copyin:
4672   case OMPC_copyprivate:
4673   case OMPC_default:
4674   case OMPC_proc_bind:
4675   case OMPC_threadprivate:
4676   case OMPC_flush:
4677   case OMPC_unknown:
4678     llvm_unreachable("Clause is not allowed.");
4679   }
4680   return Res;
4681 }
4682 
4683 OMPClause *Sema::ActOnOpenMPOrderedClause(SourceLocation StartLoc,
4684                                           SourceLocation EndLoc) {
4685   DSAStack->setOrderedRegion();
4686   return new (Context) OMPOrderedClause(StartLoc, EndLoc);
4687 }
4688 
4689 OMPClause *Sema::ActOnOpenMPNowaitClause(SourceLocation StartLoc,
4690                                          SourceLocation EndLoc) {
4691   return new (Context) OMPNowaitClause(StartLoc, EndLoc);
4692 }
4693 
4694 OMPClause *Sema::ActOnOpenMPUntiedClause(SourceLocation StartLoc,
4695                                          SourceLocation EndLoc) {
4696   return new (Context) OMPUntiedClause(StartLoc, EndLoc);
4697 }
4698 
4699 OMPClause *Sema::ActOnOpenMPMergeableClause(SourceLocation StartLoc,
4700                                             SourceLocation EndLoc) {
4701   return new (Context) OMPMergeableClause(StartLoc, EndLoc);
4702 }
4703 
4704 OMPClause *Sema::ActOnOpenMPReadClause(SourceLocation StartLoc,
4705                                        SourceLocation EndLoc) {
4706   return new (Context) OMPReadClause(StartLoc, EndLoc);
4707 }
4708 
4709 OMPClause *Sema::ActOnOpenMPWriteClause(SourceLocation StartLoc,
4710                                         SourceLocation EndLoc) {
4711   return new (Context) OMPWriteClause(StartLoc, EndLoc);
4712 }
4713 
4714 OMPClause *Sema::ActOnOpenMPUpdateClause(SourceLocation StartLoc,
4715                                          SourceLocation EndLoc) {
4716   return new (Context) OMPUpdateClause(StartLoc, EndLoc);
4717 }
4718 
4719 OMPClause *Sema::ActOnOpenMPCaptureClause(SourceLocation StartLoc,
4720                                           SourceLocation EndLoc) {
4721   return new (Context) OMPCaptureClause(StartLoc, EndLoc);
4722 }
4723 
4724 OMPClause *Sema::ActOnOpenMPSeqCstClause(SourceLocation StartLoc,
4725                                          SourceLocation EndLoc) {
4726   return new (Context) OMPSeqCstClause(StartLoc, EndLoc);
4727 }
4728 
4729 OMPClause *Sema::ActOnOpenMPVarListClause(
4730     OpenMPClauseKind Kind, ArrayRef<Expr *> VarList, Expr *TailExpr,
4731     SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation ColonLoc,
4732     SourceLocation EndLoc, CXXScopeSpec &ReductionIdScopeSpec,
4733     const DeclarationNameInfo &ReductionId) {
4734   OMPClause *Res = nullptr;
4735   switch (Kind) {
4736   case OMPC_private:
4737     Res = ActOnOpenMPPrivateClause(VarList, StartLoc, LParenLoc, EndLoc);
4738     break;
4739   case OMPC_firstprivate:
4740     Res = ActOnOpenMPFirstprivateClause(VarList, StartLoc, LParenLoc, EndLoc);
4741     break;
4742   case OMPC_lastprivate:
4743     Res = ActOnOpenMPLastprivateClause(VarList, StartLoc, LParenLoc, EndLoc);
4744     break;
4745   case OMPC_shared:
4746     Res = ActOnOpenMPSharedClause(VarList, StartLoc, LParenLoc, EndLoc);
4747     break;
4748   case OMPC_reduction:
4749     Res = ActOnOpenMPReductionClause(VarList, StartLoc, LParenLoc, ColonLoc,
4750                                      EndLoc, ReductionIdScopeSpec, ReductionId);
4751     break;
4752   case OMPC_linear:
4753     Res = ActOnOpenMPLinearClause(VarList, TailExpr, StartLoc, LParenLoc,
4754                                   ColonLoc, EndLoc);
4755     break;
4756   case OMPC_aligned:
4757     Res = ActOnOpenMPAlignedClause(VarList, TailExpr, StartLoc, LParenLoc,
4758                                    ColonLoc, EndLoc);
4759     break;
4760   case OMPC_copyin:
4761     Res = ActOnOpenMPCopyinClause(VarList, StartLoc, LParenLoc, EndLoc);
4762     break;
4763   case OMPC_copyprivate:
4764     Res = ActOnOpenMPCopyprivateClause(VarList, StartLoc, LParenLoc, EndLoc);
4765     break;
4766   case OMPC_flush:
4767     Res = ActOnOpenMPFlushClause(VarList, StartLoc, LParenLoc, EndLoc);
4768     break;
4769   case OMPC_if:
4770   case OMPC_final:
4771   case OMPC_num_threads:
4772   case OMPC_safelen:
4773   case OMPC_collapse:
4774   case OMPC_default:
4775   case OMPC_proc_bind:
4776   case OMPC_schedule:
4777   case OMPC_ordered:
4778   case OMPC_nowait:
4779   case OMPC_untied:
4780   case OMPC_mergeable:
4781   case OMPC_threadprivate:
4782   case OMPC_read:
4783   case OMPC_write:
4784   case OMPC_update:
4785   case OMPC_capture:
4786   case OMPC_seq_cst:
4787   case OMPC_unknown:
4788     llvm_unreachable("Clause is not allowed.");
4789   }
4790   return Res;
4791 }
4792 
4793 OMPClause *Sema::ActOnOpenMPPrivateClause(ArrayRef<Expr *> VarList,
4794                                           SourceLocation StartLoc,
4795                                           SourceLocation LParenLoc,
4796                                           SourceLocation EndLoc) {
4797   SmallVector<Expr *, 8> Vars;
4798   SmallVector<Expr *, 8> PrivateCopies;
4799   for (auto &RefExpr : VarList) {
4800     assert(RefExpr && "NULL expr in OpenMP private clause.");
4801     if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
4802       // It will be analyzed later.
4803       Vars.push_back(RefExpr);
4804       PrivateCopies.push_back(nullptr);
4805       continue;
4806     }
4807 
4808     SourceLocation ELoc = RefExpr->getExprLoc();
4809     // OpenMP [2.1, C/C++]
4810     //  A list item is a variable name.
4811     // OpenMP  [2.9.3.3, Restrictions, p.1]
4812     //  A variable that is part of another variable (as an array or
4813     //  structure element) cannot appear in a private clause.
4814     DeclRefExpr *DE = dyn_cast_or_null<DeclRefExpr>(RefExpr);
4815     if (!DE || !isa<VarDecl>(DE->getDecl())) {
4816       Diag(ELoc, diag::err_omp_expected_var_name) << RefExpr->getSourceRange();
4817       continue;
4818     }
4819     Decl *D = DE->getDecl();
4820     VarDecl *VD = cast<VarDecl>(D);
4821 
4822     QualType Type = VD->getType();
4823     if (Type->isDependentType() || Type->isInstantiationDependentType()) {
4824       // It will be analyzed later.
4825       Vars.push_back(DE);
4826       PrivateCopies.push_back(nullptr);
4827       continue;
4828     }
4829 
4830     // OpenMP [2.9.3.3, Restrictions, C/C++, p.3]
4831     //  A variable that appears in a private clause must not have an incomplete
4832     //  type or a reference type.
4833     if (RequireCompleteType(ELoc, Type,
4834                             diag::err_omp_private_incomplete_type)) {
4835       continue;
4836     }
4837     if (Type->isReferenceType()) {
4838       Diag(ELoc, diag::err_omp_clause_ref_type_arg)
4839           << getOpenMPClauseName(OMPC_private) << Type;
4840       bool IsDecl =
4841           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
4842       Diag(VD->getLocation(),
4843            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
4844           << VD;
4845       continue;
4846     }
4847 
4848     // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
4849     // in a Construct]
4850     //  Variables with the predetermined data-sharing attributes may not be
4851     //  listed in data-sharing attributes clauses, except for the cases
4852     //  listed below. For these exceptions only, listing a predetermined
4853     //  variable in a data-sharing attribute clause is allowed and overrides
4854     //  the variable's predetermined data-sharing attributes.
4855     DSAStackTy::DSAVarData DVar = DSAStack->getTopDSA(VD, false);
4856     if (DVar.CKind != OMPC_unknown && DVar.CKind != OMPC_private) {
4857       Diag(ELoc, diag::err_omp_wrong_dsa) << getOpenMPClauseName(DVar.CKind)
4858                                           << getOpenMPClauseName(OMPC_private);
4859       ReportOriginalDSA(*this, DSAStack, VD, DVar);
4860       continue;
4861     }
4862 
4863     // Variably modified types are not supported for tasks.
4864     if (!Type->isAnyPointerType() && Type->isVariablyModifiedType() &&
4865         DSAStack->getCurrentDirective() == OMPD_task) {
4866       Diag(ELoc, diag::err_omp_variably_modified_type_not_supported)
4867           << getOpenMPClauseName(OMPC_private) << Type
4868           << getOpenMPDirectiveName(DSAStack->getCurrentDirective());
4869       bool IsDecl =
4870           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
4871       Diag(VD->getLocation(),
4872            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
4873           << VD;
4874       continue;
4875     }
4876 
4877     // OpenMP [2.9.3.3, Restrictions, C/C++, p.1]
4878     //  A variable of class type (or array thereof) that appears in a private
4879     //  clause requires an accessible, unambiguous default constructor for the
4880     //  class type.
4881     // Generate helper private variable and initialize it with the default
4882     // value. The address of the original variable is replaced by the address of
4883     // the new private variable in CodeGen. This new variable is not added to
4884     // IdResolver, so the code in the OpenMP region uses original variable for
4885     // proper diagnostics.
4886     Type = Type.getUnqualifiedType();
4887     auto VDPrivate = buildVarDecl(*this, DE->getExprLoc(), Type, VD->getName());
4888     ActOnUninitializedDecl(VDPrivate, /*TypeMayContainAuto=*/false);
4889     if (VDPrivate->isInvalidDecl())
4890       continue;
4891     auto VDPrivateRefExpr = buildDeclRefExpr(
4892         *this, VDPrivate, DE->getType().getUnqualifiedType(), DE->getExprLoc());
4893 
4894     DSAStack->addDSA(VD, DE, OMPC_private);
4895     Vars.push_back(DE);
4896     PrivateCopies.push_back(VDPrivateRefExpr);
4897   }
4898 
4899   if (Vars.empty())
4900     return nullptr;
4901 
4902   return OMPPrivateClause::Create(Context, StartLoc, LParenLoc, EndLoc, Vars,
4903                                   PrivateCopies);
4904 }
4905 
4906 namespace {
4907 class DiagsUninitializedSeveretyRAII {
4908 private:
4909   DiagnosticsEngine &Diags;
4910   SourceLocation SavedLoc;
4911   bool IsIgnored;
4912 
4913 public:
4914   DiagsUninitializedSeveretyRAII(DiagnosticsEngine &Diags, SourceLocation Loc,
4915                                  bool IsIgnored)
4916       : Diags(Diags), SavedLoc(Loc), IsIgnored(IsIgnored) {
4917     if (!IsIgnored) {
4918       Diags.setSeverity(/*Diag*/ diag::warn_uninit_self_reference_in_init,
4919                         /*Map*/ diag::Severity::Ignored, Loc);
4920     }
4921   }
4922   ~DiagsUninitializedSeveretyRAII() {
4923     if (!IsIgnored)
4924       Diags.popMappings(SavedLoc);
4925   }
4926 };
4927 } // namespace
4928 
4929 OMPClause *Sema::ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
4930                                                SourceLocation StartLoc,
4931                                                SourceLocation LParenLoc,
4932                                                SourceLocation EndLoc) {
4933   SmallVector<Expr *, 8> Vars;
4934   SmallVector<Expr *, 8> PrivateCopies;
4935   SmallVector<Expr *, 8> Inits;
4936   bool IsImplicitClause =
4937       StartLoc.isInvalid() && LParenLoc.isInvalid() && EndLoc.isInvalid();
4938   auto ImplicitClauseLoc = DSAStack->getConstructLoc();
4939 
4940   for (auto &RefExpr : VarList) {
4941     assert(RefExpr && "NULL expr in OpenMP firstprivate clause.");
4942     if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
4943       // It will be analyzed later.
4944       Vars.push_back(RefExpr);
4945       PrivateCopies.push_back(nullptr);
4946       Inits.push_back(nullptr);
4947       continue;
4948     }
4949 
4950     SourceLocation ELoc =
4951         IsImplicitClause ? ImplicitClauseLoc : RefExpr->getExprLoc();
4952     // OpenMP [2.1, C/C++]
4953     //  A list item is a variable name.
4954     // OpenMP  [2.9.3.3, Restrictions, p.1]
4955     //  A variable that is part of another variable (as an array or
4956     //  structure element) cannot appear in a private clause.
4957     DeclRefExpr *DE = dyn_cast_or_null<DeclRefExpr>(RefExpr);
4958     if (!DE || !isa<VarDecl>(DE->getDecl())) {
4959       Diag(ELoc, diag::err_omp_expected_var_name) << RefExpr->getSourceRange();
4960       continue;
4961     }
4962     Decl *D = DE->getDecl();
4963     VarDecl *VD = cast<VarDecl>(D);
4964 
4965     QualType Type = VD->getType();
4966     if (Type->isDependentType() || Type->isInstantiationDependentType()) {
4967       // It will be analyzed later.
4968       Vars.push_back(DE);
4969       PrivateCopies.push_back(nullptr);
4970       Inits.push_back(nullptr);
4971       continue;
4972     }
4973 
4974     // OpenMP [2.9.3.3, Restrictions, C/C++, p.3]
4975     //  A variable that appears in a private clause must not have an incomplete
4976     //  type or a reference type.
4977     if (RequireCompleteType(ELoc, Type,
4978                             diag::err_omp_firstprivate_incomplete_type)) {
4979       continue;
4980     }
4981     if (Type->isReferenceType()) {
4982       if (IsImplicitClause) {
4983         Diag(ImplicitClauseLoc,
4984              diag::err_omp_task_predetermined_firstprivate_ref_type_arg)
4985             << Type;
4986         Diag(RefExpr->getExprLoc(), diag::note_used_here);
4987       } else {
4988         Diag(ELoc, diag::err_omp_clause_ref_type_arg)
4989             << getOpenMPClauseName(OMPC_firstprivate) << Type;
4990       }
4991       bool IsDecl =
4992           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
4993       Diag(VD->getLocation(),
4994            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
4995           << VD;
4996       continue;
4997     }
4998 
4999     // OpenMP [2.9.3.4, Restrictions, C/C++, p.1]
5000     //  A variable of class type (or array thereof) that appears in a private
5001     //  clause requires an accessible, unambiguous copy constructor for the
5002     //  class type.
5003     auto ElemType = Context.getBaseElementType(Type).getNonReferenceType();
5004 
5005     // If an implicit firstprivate variable found it was checked already.
5006     if (!IsImplicitClause) {
5007       DSAStackTy::DSAVarData DVar = DSAStack->getTopDSA(VD, false);
5008       bool IsConstant = ElemType.isConstant(Context);
5009       // OpenMP [2.4.13, Data-sharing Attribute Clauses]
5010       //  A list item that specifies a given variable may not appear in more
5011       // than one clause on the same directive, except that a variable may be
5012       //  specified in both firstprivate and lastprivate clauses.
5013       if (DVar.CKind != OMPC_unknown && DVar.CKind != OMPC_firstprivate &&
5014           DVar.CKind != OMPC_lastprivate && DVar.RefExpr) {
5015         Diag(ELoc, diag::err_omp_wrong_dsa)
5016             << getOpenMPClauseName(DVar.CKind)
5017             << getOpenMPClauseName(OMPC_firstprivate);
5018         ReportOriginalDSA(*this, DSAStack, VD, DVar);
5019         continue;
5020       }
5021 
5022       // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
5023       // in a Construct]
5024       //  Variables with the predetermined data-sharing attributes may not be
5025       //  listed in data-sharing attributes clauses, except for the cases
5026       //  listed below. For these exceptions only, listing a predetermined
5027       //  variable in a data-sharing attribute clause is allowed and overrides
5028       //  the variable's predetermined data-sharing attributes.
5029       // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
5030       // in a Construct, C/C++, p.2]
5031       //  Variables with const-qualified type having no mutable member may be
5032       //  listed in a firstprivate clause, even if they are static data members.
5033       if (!(IsConstant || VD->isStaticDataMember()) && !DVar.RefExpr &&
5034           DVar.CKind != OMPC_unknown && DVar.CKind != OMPC_shared) {
5035         Diag(ELoc, diag::err_omp_wrong_dsa)
5036             << getOpenMPClauseName(DVar.CKind)
5037             << getOpenMPClauseName(OMPC_firstprivate);
5038         ReportOriginalDSA(*this, DSAStack, VD, DVar);
5039         continue;
5040       }
5041 
5042       OpenMPDirectiveKind CurrDir = DSAStack->getCurrentDirective();
5043       // OpenMP [2.9.3.4, Restrictions, p.2]
5044       //  A list item that is private within a parallel region must not appear
5045       //  in a firstprivate clause on a worksharing construct if any of the
5046       //  worksharing regions arising from the worksharing construct ever bind
5047       //  to any of the parallel regions arising from the parallel construct.
5048       if (isOpenMPWorksharingDirective(CurrDir) &&
5049           !isOpenMPParallelDirective(CurrDir)) {
5050         DVar = DSAStack->getImplicitDSA(VD, true);
5051         if (DVar.CKind != OMPC_shared &&
5052             (isOpenMPParallelDirective(DVar.DKind) ||
5053              DVar.DKind == OMPD_unknown)) {
5054           Diag(ELoc, diag::err_omp_required_access)
5055               << getOpenMPClauseName(OMPC_firstprivate)
5056               << getOpenMPClauseName(OMPC_shared);
5057           ReportOriginalDSA(*this, DSAStack, VD, DVar);
5058           continue;
5059         }
5060       }
5061       // OpenMP [2.9.3.4, Restrictions, p.3]
5062       //  A list item that appears in a reduction clause of a parallel construct
5063       //  must not appear in a firstprivate clause on a worksharing or task
5064       //  construct if any of the worksharing or task regions arising from the
5065       //  worksharing or task construct ever bind to any of the parallel regions
5066       //  arising from the parallel construct.
5067       // OpenMP [2.9.3.4, Restrictions, p.4]
5068       //  A list item that appears in a reduction clause in worksharing
5069       //  construct must not appear in a firstprivate clause in a task construct
5070       //  encountered during execution of any of the worksharing regions arising
5071       //  from the worksharing construct.
5072       if (CurrDir == OMPD_task) {
5073         DVar =
5074             DSAStack->hasInnermostDSA(VD, MatchesAnyClause(OMPC_reduction),
5075                                       [](OpenMPDirectiveKind K) -> bool {
5076                                         return isOpenMPParallelDirective(K) ||
5077                                                isOpenMPWorksharingDirective(K);
5078                                       },
5079                                       false);
5080         if (DVar.CKind == OMPC_reduction &&
5081             (isOpenMPParallelDirective(DVar.DKind) ||
5082              isOpenMPWorksharingDirective(DVar.DKind))) {
5083           Diag(ELoc, diag::err_omp_parallel_reduction_in_task_firstprivate)
5084               << getOpenMPDirectiveName(DVar.DKind);
5085           ReportOriginalDSA(*this, DSAStack, VD, DVar);
5086           continue;
5087         }
5088       }
5089     }
5090 
5091     // Variably modified types are not supported for tasks.
5092     if (!Type->isAnyPointerType() && Type->isVariablyModifiedType() &&
5093         DSAStack->getCurrentDirective() == OMPD_task) {
5094       Diag(ELoc, diag::err_omp_variably_modified_type_not_supported)
5095           << getOpenMPClauseName(OMPC_firstprivate) << Type
5096           << getOpenMPDirectiveName(DSAStack->getCurrentDirective());
5097       bool IsDecl =
5098           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
5099       Diag(VD->getLocation(),
5100            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
5101           << VD;
5102       continue;
5103     }
5104 
5105     Type = Type.getUnqualifiedType();
5106     auto VDPrivate = buildVarDecl(*this, ELoc, Type, VD->getName());
5107     // Generate helper private variable and initialize it with the value of the
5108     // original variable. The address of the original variable is replaced by
5109     // the address of the new private variable in the CodeGen. This new variable
5110     // is not added to IdResolver, so the code in the OpenMP region uses
5111     // original variable for proper diagnostics and variable capturing.
5112     Expr *VDInitRefExpr = nullptr;
5113     // For arrays generate initializer for single element and replace it by the
5114     // original array element in CodeGen.
5115     if (Type->isArrayType()) {
5116       auto VDInit =
5117           buildVarDecl(*this, DE->getExprLoc(), ElemType, VD->getName());
5118       VDInitRefExpr = buildDeclRefExpr(*this, VDInit, ElemType, ELoc);
5119       auto Init = DefaultLvalueConversion(VDInitRefExpr).get();
5120       ElemType = ElemType.getUnqualifiedType();
5121       auto *VDInitTemp = buildVarDecl(*this, DE->getLocStart(), ElemType,
5122                                       ".firstprivate.temp");
5123       InitializedEntity Entity =
5124           InitializedEntity::InitializeVariable(VDInitTemp);
5125       InitializationKind Kind = InitializationKind::CreateCopy(ELoc, ELoc);
5126 
5127       InitializationSequence InitSeq(*this, Entity, Kind, Init);
5128       ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Init);
5129       if (Result.isInvalid())
5130         VDPrivate->setInvalidDecl();
5131       else
5132         VDPrivate->setInit(Result.getAs<Expr>());
5133     } else {
5134       auto *VDInit =
5135           buildVarDecl(*this, DE->getLocStart(), Type, ".firstprivate.temp");
5136       VDInitRefExpr =
5137           buildDeclRefExpr(*this, VDInit, DE->getType(), DE->getExprLoc());
5138       AddInitializerToDecl(VDPrivate,
5139                            DefaultLvalueConversion(VDInitRefExpr).get(),
5140                            /*DirectInit=*/false, /*TypeMayContainAuto=*/false);
5141     }
5142     if (VDPrivate->isInvalidDecl()) {
5143       if (IsImplicitClause) {
5144         Diag(DE->getExprLoc(),
5145              diag::note_omp_task_predetermined_firstprivate_here);
5146       }
5147       continue;
5148     }
5149     CurContext->addDecl(VDPrivate);
5150     auto VDPrivateRefExpr = buildDeclRefExpr(
5151         *this, VDPrivate, DE->getType().getUnqualifiedType(), DE->getExprLoc());
5152     DSAStack->addDSA(VD, DE, OMPC_firstprivate);
5153     Vars.push_back(DE);
5154     PrivateCopies.push_back(VDPrivateRefExpr);
5155     Inits.push_back(VDInitRefExpr);
5156   }
5157 
5158   if (Vars.empty())
5159     return nullptr;
5160 
5161   return OMPFirstprivateClause::Create(Context, StartLoc, LParenLoc, EndLoc,
5162                                        Vars, PrivateCopies, Inits);
5163 }
5164 
5165 OMPClause *Sema::ActOnOpenMPLastprivateClause(ArrayRef<Expr *> VarList,
5166                                               SourceLocation StartLoc,
5167                                               SourceLocation LParenLoc,
5168                                               SourceLocation EndLoc) {
5169   SmallVector<Expr *, 8> Vars;
5170   SmallVector<Expr *, 8> SrcExprs;
5171   SmallVector<Expr *, 8> DstExprs;
5172   SmallVector<Expr *, 8> AssignmentOps;
5173   for (auto &RefExpr : VarList) {
5174     assert(RefExpr && "NULL expr in OpenMP lastprivate clause.");
5175     if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
5176       // It will be analyzed later.
5177       Vars.push_back(RefExpr);
5178       SrcExprs.push_back(nullptr);
5179       DstExprs.push_back(nullptr);
5180       AssignmentOps.push_back(nullptr);
5181       continue;
5182     }
5183 
5184     SourceLocation ELoc = RefExpr->getExprLoc();
5185     // OpenMP [2.1, C/C++]
5186     //  A list item is a variable name.
5187     // OpenMP  [2.14.3.5, Restrictions, p.1]
5188     //  A variable that is part of another variable (as an array or structure
5189     //  element) cannot appear in a lastprivate clause.
5190     DeclRefExpr *DE = dyn_cast_or_null<DeclRefExpr>(RefExpr);
5191     if (!DE || !isa<VarDecl>(DE->getDecl())) {
5192       Diag(ELoc, diag::err_omp_expected_var_name) << RefExpr->getSourceRange();
5193       continue;
5194     }
5195     Decl *D = DE->getDecl();
5196     VarDecl *VD = cast<VarDecl>(D);
5197 
5198     QualType Type = VD->getType();
5199     if (Type->isDependentType() || Type->isInstantiationDependentType()) {
5200       // It will be analyzed later.
5201       Vars.push_back(DE);
5202       SrcExprs.push_back(nullptr);
5203       DstExprs.push_back(nullptr);
5204       AssignmentOps.push_back(nullptr);
5205       continue;
5206     }
5207 
5208     // OpenMP [2.14.3.5, Restrictions, C/C++, p.2]
5209     //  A variable that appears in a lastprivate clause must not have an
5210     //  incomplete type or a reference type.
5211     if (RequireCompleteType(ELoc, Type,
5212                             diag::err_omp_lastprivate_incomplete_type)) {
5213       continue;
5214     }
5215     if (Type->isReferenceType()) {
5216       Diag(ELoc, diag::err_omp_clause_ref_type_arg)
5217           << getOpenMPClauseName(OMPC_lastprivate) << Type;
5218       bool IsDecl =
5219           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
5220       Diag(VD->getLocation(),
5221            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
5222           << VD;
5223       continue;
5224     }
5225 
5226     // OpenMP [2.14.1.1, Data-sharing Attribute Rules for Variables Referenced
5227     // in a Construct]
5228     //  Variables with the predetermined data-sharing attributes may not be
5229     //  listed in data-sharing attributes clauses, except for the cases
5230     //  listed below.
5231     DSAStackTy::DSAVarData DVar = DSAStack->getTopDSA(VD, false);
5232     if (DVar.CKind != OMPC_unknown && DVar.CKind != OMPC_lastprivate &&
5233         DVar.CKind != OMPC_firstprivate &&
5234         (DVar.CKind != OMPC_private || DVar.RefExpr != nullptr)) {
5235       Diag(ELoc, diag::err_omp_wrong_dsa)
5236           << getOpenMPClauseName(DVar.CKind)
5237           << getOpenMPClauseName(OMPC_lastprivate);
5238       ReportOriginalDSA(*this, DSAStack, VD, DVar);
5239       continue;
5240     }
5241 
5242     OpenMPDirectiveKind CurrDir = DSAStack->getCurrentDirective();
5243     // OpenMP [2.14.3.5, Restrictions, p.2]
5244     // A list item that is private within a parallel region, or that appears in
5245     // the reduction clause of a parallel construct, must not appear in a
5246     // lastprivate clause on a worksharing construct if any of the corresponding
5247     // worksharing regions ever binds to any of the corresponding parallel
5248     // regions.
5249     DSAStackTy::DSAVarData TopDVar = DVar;
5250     if (isOpenMPWorksharingDirective(CurrDir) &&
5251         !isOpenMPParallelDirective(CurrDir)) {
5252       DVar = DSAStack->getImplicitDSA(VD, true);
5253       if (DVar.CKind != OMPC_shared) {
5254         Diag(ELoc, diag::err_omp_required_access)
5255             << getOpenMPClauseName(OMPC_lastprivate)
5256             << getOpenMPClauseName(OMPC_shared);
5257         ReportOriginalDSA(*this, DSAStack, VD, DVar);
5258         continue;
5259       }
5260     }
5261     // OpenMP [2.14.3.5, Restrictions, C++, p.1,2]
5262     //  A variable of class type (or array thereof) that appears in a
5263     //  lastprivate clause requires an accessible, unambiguous default
5264     //  constructor for the class type, unless the list item is also specified
5265     //  in a firstprivate clause.
5266     //  A variable of class type (or array thereof) that appears in a
5267     //  lastprivate clause requires an accessible, unambiguous copy assignment
5268     //  operator for the class type.
5269     Type = Context.getBaseElementType(Type).getNonReferenceType();
5270     auto *SrcVD = buildVarDecl(*this, DE->getLocStart(),
5271                                Type.getUnqualifiedType(), ".lastprivate.src");
5272     auto *PseudoSrcExpr = buildDeclRefExpr(
5273         *this, SrcVD, Type.getUnqualifiedType(), DE->getExprLoc());
5274     auto *DstVD =
5275         buildVarDecl(*this, DE->getLocStart(), Type, ".lastprivate.dst");
5276     auto *PseudoDstExpr =
5277         buildDeclRefExpr(*this, DstVD, Type, DE->getExprLoc());
5278     // For arrays generate assignment operation for single element and replace
5279     // it by the original array element in CodeGen.
5280     auto AssignmentOp = BuildBinOp(/*S=*/nullptr, DE->getExprLoc(), BO_Assign,
5281                                    PseudoDstExpr, PseudoSrcExpr);
5282     if (AssignmentOp.isInvalid())
5283       continue;
5284     AssignmentOp = ActOnFinishFullExpr(AssignmentOp.get(), DE->getExprLoc(),
5285                                        /*DiscardedValue=*/true);
5286     if (AssignmentOp.isInvalid())
5287       continue;
5288 
5289     if (TopDVar.CKind != OMPC_firstprivate)
5290       DSAStack->addDSA(VD, DE, OMPC_lastprivate);
5291     Vars.push_back(DE);
5292     SrcExprs.push_back(PseudoSrcExpr);
5293     DstExprs.push_back(PseudoDstExpr);
5294     AssignmentOps.push_back(AssignmentOp.get());
5295   }
5296 
5297   if (Vars.empty())
5298     return nullptr;
5299 
5300   return OMPLastprivateClause::Create(Context, StartLoc, LParenLoc, EndLoc,
5301                                       Vars, SrcExprs, DstExprs, AssignmentOps);
5302 }
5303 
5304 OMPClause *Sema::ActOnOpenMPSharedClause(ArrayRef<Expr *> VarList,
5305                                          SourceLocation StartLoc,
5306                                          SourceLocation LParenLoc,
5307                                          SourceLocation EndLoc) {
5308   SmallVector<Expr *, 8> Vars;
5309   for (auto &RefExpr : VarList) {
5310     assert(RefExpr && "NULL expr in OpenMP shared clause.");
5311     if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
5312       // It will be analyzed later.
5313       Vars.push_back(RefExpr);
5314       continue;
5315     }
5316 
5317     SourceLocation ELoc = RefExpr->getExprLoc();
5318     // OpenMP [2.1, C/C++]
5319     //  A list item is a variable name.
5320     // OpenMP  [2.14.3.2, Restrictions, p.1]
5321     //  A variable that is part of another variable (as an array or structure
5322     //  element) cannot appear in a shared unless it is a static data member
5323     //  of a C++ class.
5324     DeclRefExpr *DE = dyn_cast<DeclRefExpr>(RefExpr);
5325     if (!DE || !isa<VarDecl>(DE->getDecl())) {
5326       Diag(ELoc, diag::err_omp_expected_var_name) << RefExpr->getSourceRange();
5327       continue;
5328     }
5329     Decl *D = DE->getDecl();
5330     VarDecl *VD = cast<VarDecl>(D);
5331 
5332     QualType Type = VD->getType();
5333     if (Type->isDependentType() || Type->isInstantiationDependentType()) {
5334       // It will be analyzed later.
5335       Vars.push_back(DE);
5336       continue;
5337     }
5338 
5339     // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
5340     // in a Construct]
5341     //  Variables with the predetermined data-sharing attributes may not be
5342     //  listed in data-sharing attributes clauses, except for the cases
5343     //  listed below. For these exceptions only, listing a predetermined
5344     //  variable in a data-sharing attribute clause is allowed and overrides
5345     //  the variable's predetermined data-sharing attributes.
5346     DSAStackTy::DSAVarData DVar = DSAStack->getTopDSA(VD, false);
5347     if (DVar.CKind != OMPC_unknown && DVar.CKind != OMPC_shared &&
5348         DVar.RefExpr) {
5349       Diag(ELoc, diag::err_omp_wrong_dsa) << getOpenMPClauseName(DVar.CKind)
5350                                           << getOpenMPClauseName(OMPC_shared);
5351       ReportOriginalDSA(*this, DSAStack, VD, DVar);
5352       continue;
5353     }
5354 
5355     DSAStack->addDSA(VD, DE, OMPC_shared);
5356     Vars.push_back(DE);
5357   }
5358 
5359   if (Vars.empty())
5360     return nullptr;
5361 
5362   return OMPSharedClause::Create(Context, StartLoc, LParenLoc, EndLoc, Vars);
5363 }
5364 
5365 namespace {
5366 class DSARefChecker : public StmtVisitor<DSARefChecker, bool> {
5367   DSAStackTy *Stack;
5368 
5369 public:
5370   bool VisitDeclRefExpr(DeclRefExpr *E) {
5371     if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) {
5372       DSAStackTy::DSAVarData DVar = Stack->getTopDSA(VD, false);
5373       if (DVar.CKind == OMPC_shared && !DVar.RefExpr)
5374         return false;
5375       if (DVar.CKind != OMPC_unknown)
5376         return true;
5377       DSAStackTy::DSAVarData DVarPrivate =
5378           Stack->hasDSA(VD, isOpenMPPrivate, MatchesAlways(), false);
5379       if (DVarPrivate.CKind != OMPC_unknown)
5380         return true;
5381       return false;
5382     }
5383     return false;
5384   }
5385   bool VisitStmt(Stmt *S) {
5386     for (auto Child : S->children()) {
5387       if (Child && Visit(Child))
5388         return true;
5389     }
5390     return false;
5391   }
5392   explicit DSARefChecker(DSAStackTy *S) : Stack(S) {}
5393 };
5394 } // namespace
5395 
5396 OMPClause *Sema::ActOnOpenMPReductionClause(
5397     ArrayRef<Expr *> VarList, SourceLocation StartLoc, SourceLocation LParenLoc,
5398     SourceLocation ColonLoc, SourceLocation EndLoc,
5399     CXXScopeSpec &ReductionIdScopeSpec,
5400     const DeclarationNameInfo &ReductionId) {
5401   // TODO: Allow scope specification search when 'declare reduction' is
5402   // supported.
5403   assert(ReductionIdScopeSpec.isEmpty() &&
5404          "No support for scoped reduction identifiers yet.");
5405 
5406   auto DN = ReductionId.getName();
5407   auto OOK = DN.getCXXOverloadedOperator();
5408   BinaryOperatorKind BOK = BO_Comma;
5409 
5410   // OpenMP [2.14.3.6, reduction clause]
5411   // C
5412   // reduction-identifier is either an identifier or one of the following
5413   // operators: +, -, *,  &, |, ^, && and ||
5414   // C++
5415   // reduction-identifier is either an id-expression or one of the following
5416   // operators: +, -, *, &, |, ^, && and ||
5417   // FIXME: Only 'min' and 'max' identifiers are supported for now.
5418   switch (OOK) {
5419   case OO_Plus:
5420   case OO_Minus:
5421     BOK = BO_Add;
5422     break;
5423   case OO_Star:
5424     BOK = BO_Mul;
5425     break;
5426   case OO_Amp:
5427     BOK = BO_And;
5428     break;
5429   case OO_Pipe:
5430     BOK = BO_Or;
5431     break;
5432   case OO_Caret:
5433     BOK = BO_Xor;
5434     break;
5435   case OO_AmpAmp:
5436     BOK = BO_LAnd;
5437     break;
5438   case OO_PipePipe:
5439     BOK = BO_LOr;
5440     break;
5441   case OO_New:
5442   case OO_Delete:
5443   case OO_Array_New:
5444   case OO_Array_Delete:
5445   case OO_Slash:
5446   case OO_Percent:
5447   case OO_Tilde:
5448   case OO_Exclaim:
5449   case OO_Equal:
5450   case OO_Less:
5451   case OO_Greater:
5452   case OO_LessEqual:
5453   case OO_GreaterEqual:
5454   case OO_PlusEqual:
5455   case OO_MinusEqual:
5456   case OO_StarEqual:
5457   case OO_SlashEqual:
5458   case OO_PercentEqual:
5459   case OO_CaretEqual:
5460   case OO_AmpEqual:
5461   case OO_PipeEqual:
5462   case OO_LessLess:
5463   case OO_GreaterGreater:
5464   case OO_LessLessEqual:
5465   case OO_GreaterGreaterEqual:
5466   case OO_EqualEqual:
5467   case OO_ExclaimEqual:
5468   case OO_PlusPlus:
5469   case OO_MinusMinus:
5470   case OO_Comma:
5471   case OO_ArrowStar:
5472   case OO_Arrow:
5473   case OO_Call:
5474   case OO_Subscript:
5475   case OO_Conditional:
5476   case NUM_OVERLOADED_OPERATORS:
5477     llvm_unreachable("Unexpected reduction identifier");
5478   case OO_None:
5479     if (auto II = DN.getAsIdentifierInfo()) {
5480       if (II->isStr("max"))
5481         BOK = BO_GT;
5482       else if (II->isStr("min"))
5483         BOK = BO_LT;
5484     }
5485     break;
5486   }
5487   SourceRange ReductionIdRange;
5488   if (ReductionIdScopeSpec.isValid()) {
5489     ReductionIdRange.setBegin(ReductionIdScopeSpec.getBeginLoc());
5490   }
5491   ReductionIdRange.setEnd(ReductionId.getEndLoc());
5492   if (BOK == BO_Comma) {
5493     // Not allowed reduction identifier is found.
5494     Diag(ReductionId.getLocStart(), diag::err_omp_unknown_reduction_identifier)
5495         << ReductionIdRange;
5496     return nullptr;
5497   }
5498 
5499   SmallVector<Expr *, 8> Vars;
5500   SmallVector<Expr *, 8> LHSs;
5501   SmallVector<Expr *, 8> RHSs;
5502   SmallVector<Expr *, 8> ReductionOps;
5503   for (auto RefExpr : VarList) {
5504     assert(RefExpr && "nullptr expr in OpenMP reduction clause.");
5505     if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
5506       // It will be analyzed later.
5507       Vars.push_back(RefExpr);
5508       LHSs.push_back(nullptr);
5509       RHSs.push_back(nullptr);
5510       ReductionOps.push_back(nullptr);
5511       continue;
5512     }
5513 
5514     if (RefExpr->isTypeDependent() || RefExpr->isValueDependent() ||
5515         RefExpr->isInstantiationDependent() ||
5516         RefExpr->containsUnexpandedParameterPack()) {
5517       // It will be analyzed later.
5518       Vars.push_back(RefExpr);
5519       LHSs.push_back(nullptr);
5520       RHSs.push_back(nullptr);
5521       ReductionOps.push_back(nullptr);
5522       continue;
5523     }
5524 
5525     auto ELoc = RefExpr->getExprLoc();
5526     auto ERange = RefExpr->getSourceRange();
5527     // OpenMP [2.1, C/C++]
5528     //  A list item is a variable or array section, subject to the restrictions
5529     //  specified in Section 2.4 on page 42 and in each of the sections
5530     // describing clauses and directives for which a list appears.
5531     // OpenMP  [2.14.3.3, Restrictions, p.1]
5532     //  A variable that is part of another variable (as an array or
5533     //  structure element) cannot appear in a private clause.
5534     auto DE = dyn_cast<DeclRefExpr>(RefExpr);
5535     if (!DE || !isa<VarDecl>(DE->getDecl())) {
5536       Diag(ELoc, diag::err_omp_expected_var_name) << ERange;
5537       continue;
5538     }
5539     auto D = DE->getDecl();
5540     auto VD = cast<VarDecl>(D);
5541     auto Type = VD->getType();
5542     // OpenMP [2.9.3.3, Restrictions, C/C++, p.3]
5543     //  A variable that appears in a private clause must not have an incomplete
5544     //  type or a reference type.
5545     if (RequireCompleteType(ELoc, Type,
5546                             diag::err_omp_reduction_incomplete_type))
5547       continue;
5548     // OpenMP [2.14.3.6, reduction clause, Restrictions]
5549     // Arrays may not appear in a reduction clause.
5550     if (Type.getNonReferenceType()->isArrayType()) {
5551       Diag(ELoc, diag::err_omp_reduction_type_array) << Type << ERange;
5552       bool IsDecl =
5553           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
5554       Diag(VD->getLocation(),
5555            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
5556           << VD;
5557       continue;
5558     }
5559     // OpenMP [2.14.3.6, reduction clause, Restrictions]
5560     // A list item that appears in a reduction clause must not be
5561     // const-qualified.
5562     if (Type.getNonReferenceType().isConstant(Context)) {
5563       Diag(ELoc, diag::err_omp_const_variable)
5564           << getOpenMPClauseName(OMPC_reduction) << Type << ERange;
5565       bool IsDecl =
5566           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
5567       Diag(VD->getLocation(),
5568            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
5569           << VD;
5570       continue;
5571     }
5572     // OpenMP [2.9.3.6, Restrictions, C/C++, p.4]
5573     //  If a list-item is a reference type then it must bind to the same object
5574     //  for all threads of the team.
5575     VarDecl *VDDef = VD->getDefinition();
5576     if (Type->isReferenceType() && VDDef) {
5577       DSARefChecker Check(DSAStack);
5578       if (Check.Visit(VDDef->getInit())) {
5579         Diag(ELoc, diag::err_omp_reduction_ref_type_arg) << ERange;
5580         Diag(VDDef->getLocation(), diag::note_defined_here) << VDDef;
5581         continue;
5582       }
5583     }
5584     // OpenMP [2.14.3.6, reduction clause, Restrictions]
5585     // The type of a list item that appears in a reduction clause must be valid
5586     // for the reduction-identifier. For a max or min reduction in C, the type
5587     // of the list item must be an allowed arithmetic data type: char, int,
5588     // float, double, or _Bool, possibly modified with long, short, signed, or
5589     // unsigned. For a max or min reduction in C++, the type of the list item
5590     // must be an allowed arithmetic data type: char, wchar_t, int, float,
5591     // double, or bool, possibly modified with long, short, signed, or unsigned.
5592     if ((BOK == BO_GT || BOK == BO_LT) &&
5593         !(Type->isScalarType() ||
5594           (getLangOpts().CPlusPlus && Type->isArithmeticType()))) {
5595       Diag(ELoc, diag::err_omp_clause_not_arithmetic_type_arg)
5596           << getLangOpts().CPlusPlus;
5597       bool IsDecl =
5598           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
5599       Diag(VD->getLocation(),
5600            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
5601           << VD;
5602       continue;
5603     }
5604     if ((BOK == BO_OrAssign || BOK == BO_AndAssign || BOK == BO_XorAssign) &&
5605         !getLangOpts().CPlusPlus && Type->isFloatingType()) {
5606       Diag(ELoc, diag::err_omp_clause_floating_type_arg);
5607       bool IsDecl =
5608           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
5609       Diag(VD->getLocation(),
5610            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
5611           << VD;
5612       continue;
5613     }
5614     // OpenMP [2.14.1.1, Data-sharing Attribute Rules for Variables Referenced
5615     // in a Construct]
5616     //  Variables with the predetermined data-sharing attributes may not be
5617     //  listed in data-sharing attributes clauses, except for the cases
5618     //  listed below. For these exceptions only, listing a predetermined
5619     //  variable in a data-sharing attribute clause is allowed and overrides
5620     //  the variable's predetermined data-sharing attributes.
5621     // OpenMP [2.14.3.6, Restrictions, p.3]
5622     //  Any number of reduction clauses can be specified on the directive,
5623     //  but a list item can appear only once in the reduction clauses for that
5624     //  directive.
5625     DSAStackTy::DSAVarData DVar = DSAStack->getTopDSA(VD, false);
5626     if (DVar.CKind == OMPC_reduction) {
5627       Diag(ELoc, diag::err_omp_once_referenced)
5628           << getOpenMPClauseName(OMPC_reduction);
5629       if (DVar.RefExpr) {
5630         Diag(DVar.RefExpr->getExprLoc(), diag::note_omp_referenced);
5631       }
5632     } else if (DVar.CKind != OMPC_unknown) {
5633       Diag(ELoc, diag::err_omp_wrong_dsa)
5634           << getOpenMPClauseName(DVar.CKind)
5635           << getOpenMPClauseName(OMPC_reduction);
5636       ReportOriginalDSA(*this, DSAStack, VD, DVar);
5637       continue;
5638     }
5639 
5640     // OpenMP [2.14.3.6, Restrictions, p.1]
5641     //  A list item that appears in a reduction clause of a worksharing
5642     //  construct must be shared in the parallel regions to which any of the
5643     //  worksharing regions arising from the worksharing construct bind.
5644     OpenMPDirectiveKind CurrDir = DSAStack->getCurrentDirective();
5645     if (isOpenMPWorksharingDirective(CurrDir) &&
5646         !isOpenMPParallelDirective(CurrDir)) {
5647       DVar = DSAStack->getImplicitDSA(VD, true);
5648       if (DVar.CKind != OMPC_shared) {
5649         Diag(ELoc, diag::err_omp_required_access)
5650             << getOpenMPClauseName(OMPC_reduction)
5651             << getOpenMPClauseName(OMPC_shared);
5652         ReportOriginalDSA(*this, DSAStack, VD, DVar);
5653         continue;
5654       }
5655     }
5656     Type = Type.getNonLValueExprType(Context).getUnqualifiedType();
5657     auto *LHSVD = buildVarDecl(*this, ELoc, Type, ".reduction.lhs");
5658     auto *RHSVD = buildVarDecl(*this, ELoc, Type, VD->getName());
5659     // Add initializer for private variable.
5660     Expr *Init = nullptr;
5661     switch (BOK) {
5662     case BO_Add:
5663     case BO_Xor:
5664     case BO_Or:
5665     case BO_LOr:
5666       // '+', '-', '^', '|', '||' reduction ops - initializer is '0'.
5667       if (Type->isScalarType() || Type->isAnyComplexType()) {
5668         Init = ActOnIntegerConstant(ELoc, /*Val=*/0).get();
5669       }
5670       break;
5671     case BO_Mul:
5672     case BO_LAnd:
5673       if (Type->isScalarType() || Type->isAnyComplexType()) {
5674         // '*' and '&&' reduction ops - initializer is '1'.
5675         Init = ActOnIntegerConstant(ELoc, /*Val=*/1).get();
5676       }
5677       break;
5678     case BO_And: {
5679       // '&' reduction op - initializer is '~0'.
5680       QualType OrigType = Type;
5681       if (auto *ComplexTy = OrigType->getAs<ComplexType>()) {
5682         Type = ComplexTy->getElementType();
5683       }
5684       if (Type->isRealFloatingType()) {
5685         llvm::APFloat InitValue =
5686             llvm::APFloat::getAllOnesValue(Context.getTypeSize(Type),
5687                                            /*isIEEE=*/true);
5688         Init = FloatingLiteral::Create(Context, InitValue, /*isexact=*/true,
5689                                        Type, ELoc);
5690       } else if (Type->isScalarType()) {
5691         auto Size = Context.getTypeSize(Type);
5692         QualType IntTy = Context.getIntTypeForBitwidth(Size, /*Signed=*/0);
5693         llvm::APInt InitValue = llvm::APInt::getAllOnesValue(Size);
5694         Init = IntegerLiteral::Create(Context, InitValue, IntTy, ELoc);
5695       }
5696       if (Init && OrigType->isAnyComplexType()) {
5697         // Init = 0xFFFF + 0xFFFFi;
5698         auto *Im = new (Context) ImaginaryLiteral(Init, OrigType);
5699         Init = CreateBuiltinBinOp(ELoc, BO_Add, Init, Im).get();
5700       }
5701       Type = OrigType;
5702       break;
5703     }
5704     case BO_LT:
5705     case BO_GT: {
5706       // 'min' reduction op - initializer is 'Largest representable number in
5707       // the reduction list item type'.
5708       // 'max' reduction op - initializer is 'Least representable number in
5709       // the reduction list item type'.
5710       if (Type->isIntegerType() || Type->isPointerType()) {
5711         bool IsSigned = Type->hasSignedIntegerRepresentation();
5712         auto Size = Context.getTypeSize(Type);
5713         QualType IntTy =
5714             Context.getIntTypeForBitwidth(Size, /*Signed=*/IsSigned);
5715         llvm::APInt InitValue =
5716             (BOK != BO_LT)
5717                 ? IsSigned ? llvm::APInt::getSignedMinValue(Size)
5718                            : llvm::APInt::getMinValue(Size)
5719                 : IsSigned ? llvm::APInt::getSignedMaxValue(Size)
5720                            : llvm::APInt::getMaxValue(Size);
5721         Init = IntegerLiteral::Create(Context, InitValue, IntTy, ELoc);
5722         if (Type->isPointerType()) {
5723           // Cast to pointer type.
5724           auto CastExpr = BuildCStyleCastExpr(
5725               SourceLocation(), Context.getTrivialTypeSourceInfo(Type, ELoc),
5726               SourceLocation(), Init);
5727           if (CastExpr.isInvalid())
5728             continue;
5729           Init = CastExpr.get();
5730         }
5731       } else if (Type->isRealFloatingType()) {
5732         llvm::APFloat InitValue = llvm::APFloat::getLargest(
5733             Context.getFloatTypeSemantics(Type), BOK != BO_LT);
5734         Init = FloatingLiteral::Create(Context, InitValue, /*isexact=*/true,
5735                                        Type, ELoc);
5736       }
5737       break;
5738     }
5739     case BO_PtrMemD:
5740     case BO_PtrMemI:
5741     case BO_MulAssign:
5742     case BO_Div:
5743     case BO_Rem:
5744     case BO_Sub:
5745     case BO_Shl:
5746     case BO_Shr:
5747     case BO_LE:
5748     case BO_GE:
5749     case BO_EQ:
5750     case BO_NE:
5751     case BO_AndAssign:
5752     case BO_XorAssign:
5753     case BO_OrAssign:
5754     case BO_Assign:
5755     case BO_AddAssign:
5756     case BO_SubAssign:
5757     case BO_DivAssign:
5758     case BO_RemAssign:
5759     case BO_ShlAssign:
5760     case BO_ShrAssign:
5761     case BO_Comma:
5762       llvm_unreachable("Unexpected reduction operation");
5763     }
5764     if (Init) {
5765       AddInitializerToDecl(RHSVD, Init, /*DirectInit=*/false,
5766                            /*TypeMayContainAuto=*/false);
5767     } else {
5768       ActOnUninitializedDecl(RHSVD, /*TypeMayContainAuto=*/false);
5769     }
5770     if (!RHSVD->hasInit()) {
5771       Diag(ELoc, diag::err_omp_reduction_id_not_compatible) << Type
5772                                                             << ReductionIdRange;
5773       bool IsDecl =
5774           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
5775       Diag(VD->getLocation(),
5776            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
5777           << VD;
5778       continue;
5779     }
5780     auto *LHSDRE = buildDeclRefExpr(*this, LHSVD, Type, ELoc);
5781     auto *RHSDRE = buildDeclRefExpr(*this, RHSVD, Type, ELoc);
5782     ExprResult ReductionOp =
5783         BuildBinOp(DSAStack->getCurScope(), ReductionId.getLocStart(), BOK,
5784                    LHSDRE, RHSDRE);
5785     if (ReductionOp.isUsable()) {
5786       if (BOK != BO_LT && BOK != BO_GT) {
5787         ReductionOp =
5788             BuildBinOp(DSAStack->getCurScope(), ReductionId.getLocStart(),
5789                        BO_Assign, LHSDRE, ReductionOp.get());
5790       } else {
5791         auto *ConditionalOp = new (Context) ConditionalOperator(
5792             ReductionOp.get(), SourceLocation(), LHSDRE, SourceLocation(),
5793             RHSDRE, Type, VK_LValue, OK_Ordinary);
5794         ReductionOp =
5795             BuildBinOp(DSAStack->getCurScope(), ReductionId.getLocStart(),
5796                        BO_Assign, LHSDRE, ConditionalOp);
5797       }
5798       if (ReductionOp.isUsable()) {
5799         ReductionOp = ActOnFinishFullExpr(ReductionOp.get());
5800       }
5801     }
5802     if (ReductionOp.isInvalid())
5803       continue;
5804 
5805     DSAStack->addDSA(VD, DE, OMPC_reduction);
5806     Vars.push_back(DE);
5807     LHSs.push_back(LHSDRE);
5808     RHSs.push_back(RHSDRE);
5809     ReductionOps.push_back(ReductionOp.get());
5810   }
5811 
5812   if (Vars.empty())
5813     return nullptr;
5814 
5815   return OMPReductionClause::Create(
5816       Context, StartLoc, LParenLoc, ColonLoc, EndLoc, Vars,
5817       ReductionIdScopeSpec.getWithLocInContext(Context), ReductionId, LHSs,
5818       RHSs, ReductionOps);
5819 }
5820 
5821 OMPClause *Sema::ActOnOpenMPLinearClause(ArrayRef<Expr *> VarList, Expr *Step,
5822                                          SourceLocation StartLoc,
5823                                          SourceLocation LParenLoc,
5824                                          SourceLocation ColonLoc,
5825                                          SourceLocation EndLoc) {
5826   SmallVector<Expr *, 8> Vars;
5827   SmallVector<Expr *, 8> Inits;
5828   for (auto &RefExpr : VarList) {
5829     assert(RefExpr && "NULL expr in OpenMP linear clause.");
5830     if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
5831       // It will be analyzed later.
5832       Vars.push_back(RefExpr);
5833       Inits.push_back(nullptr);
5834       continue;
5835     }
5836 
5837     // OpenMP [2.14.3.7, linear clause]
5838     // A list item that appears in a linear clause is subject to the private
5839     // clause semantics described in Section 2.14.3.3 on page 159 except as
5840     // noted. In addition, the value of the new list item on each iteration
5841     // of the associated loop(s) corresponds to the value of the original
5842     // list item before entering the construct plus the logical number of
5843     // the iteration times linear-step.
5844 
5845     SourceLocation ELoc = RefExpr->getExprLoc();
5846     // OpenMP [2.1, C/C++]
5847     //  A list item is a variable name.
5848     // OpenMP  [2.14.3.3, Restrictions, p.1]
5849     //  A variable that is part of another variable (as an array or
5850     //  structure element) cannot appear in a private clause.
5851     DeclRefExpr *DE = dyn_cast<DeclRefExpr>(RefExpr);
5852     if (!DE || !isa<VarDecl>(DE->getDecl())) {
5853       Diag(ELoc, diag::err_omp_expected_var_name) << RefExpr->getSourceRange();
5854       continue;
5855     }
5856 
5857     VarDecl *VD = cast<VarDecl>(DE->getDecl());
5858 
5859     // OpenMP [2.14.3.7, linear clause]
5860     //  A list-item cannot appear in more than one linear clause.
5861     //  A list-item that appears in a linear clause cannot appear in any
5862     //  other data-sharing attribute clause.
5863     DSAStackTy::DSAVarData DVar = DSAStack->getTopDSA(VD, false);
5864     if (DVar.RefExpr) {
5865       Diag(ELoc, diag::err_omp_wrong_dsa) << getOpenMPClauseName(DVar.CKind)
5866                                           << getOpenMPClauseName(OMPC_linear);
5867       ReportOriginalDSA(*this, DSAStack, VD, DVar);
5868       continue;
5869     }
5870 
5871     QualType QType = VD->getType();
5872     if (QType->isDependentType() || QType->isInstantiationDependentType()) {
5873       // It will be analyzed later.
5874       Vars.push_back(DE);
5875       Inits.push_back(nullptr);
5876       continue;
5877     }
5878 
5879     // A variable must not have an incomplete type or a reference type.
5880     if (RequireCompleteType(ELoc, QType,
5881                             diag::err_omp_linear_incomplete_type)) {
5882       continue;
5883     }
5884     if (QType->isReferenceType()) {
5885       Diag(ELoc, diag::err_omp_clause_ref_type_arg)
5886           << getOpenMPClauseName(OMPC_linear) << QType;
5887       bool IsDecl =
5888           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
5889       Diag(VD->getLocation(),
5890            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
5891           << VD;
5892       continue;
5893     }
5894 
5895     // A list item must not be const-qualified.
5896     if (QType.isConstant(Context)) {
5897       Diag(ELoc, diag::err_omp_const_variable)
5898           << getOpenMPClauseName(OMPC_linear);
5899       bool IsDecl =
5900           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
5901       Diag(VD->getLocation(),
5902            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
5903           << VD;
5904       continue;
5905     }
5906 
5907     // A list item must be of integral or pointer type.
5908     QType = QType.getUnqualifiedType().getCanonicalType();
5909     const Type *Ty = QType.getTypePtrOrNull();
5910     if (!Ty || (!Ty->isDependentType() && !Ty->isIntegralType(Context) &&
5911                 !Ty->isPointerType())) {
5912       Diag(ELoc, diag::err_omp_linear_expected_int_or_ptr) << QType;
5913       bool IsDecl =
5914           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
5915       Diag(VD->getLocation(),
5916            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
5917           << VD;
5918       continue;
5919     }
5920 
5921     // Build var to save initial value.
5922     VarDecl *Init = buildVarDecl(*this, ELoc, QType, ".linear.start");
5923     AddInitializerToDecl(Init, DefaultLvalueConversion(DE).get(),
5924                          /*DirectInit*/ false, /*TypeMayContainAuto*/ false);
5925     auto InitRef = buildDeclRefExpr(
5926         *this, Init, DE->getType().getUnqualifiedType(), DE->getExprLoc());
5927     DSAStack->addDSA(VD, DE, OMPC_linear);
5928     Vars.push_back(DE);
5929     Inits.push_back(InitRef);
5930   }
5931 
5932   if (Vars.empty())
5933     return nullptr;
5934 
5935   Expr *StepExpr = Step;
5936   Expr *CalcStepExpr = nullptr;
5937   if (Step && !Step->isValueDependent() && !Step->isTypeDependent() &&
5938       !Step->isInstantiationDependent() &&
5939       !Step->containsUnexpandedParameterPack()) {
5940     SourceLocation StepLoc = Step->getLocStart();
5941     ExprResult Val = PerformOpenMPImplicitIntegerConversion(StepLoc, Step);
5942     if (Val.isInvalid())
5943       return nullptr;
5944     StepExpr = Val.get();
5945 
5946     // Build var to save the step value.
5947     VarDecl *SaveVar =
5948         buildVarDecl(*this, StepLoc, StepExpr->getType(), ".linear.step");
5949     ExprResult SaveRef =
5950         buildDeclRefExpr(*this, SaveVar, StepExpr->getType(), StepLoc);
5951     ExprResult CalcStep =
5952         BuildBinOp(CurScope, StepLoc, BO_Assign, SaveRef.get(), StepExpr);
5953 
5954     // Warn about zero linear step (it would be probably better specified as
5955     // making corresponding variables 'const').
5956     llvm::APSInt Result;
5957     bool IsConstant = StepExpr->isIntegerConstantExpr(Result, Context);
5958     if (IsConstant && !Result.isNegative() && !Result.isStrictlyPositive())
5959       Diag(StepLoc, diag::warn_omp_linear_step_zero) << Vars[0]
5960                                                      << (Vars.size() > 1);
5961     if (!IsConstant && CalcStep.isUsable()) {
5962       // Calculate the step beforehand instead of doing this on each iteration.
5963       // (This is not used if the number of iterations may be kfold-ed).
5964       CalcStepExpr = CalcStep.get();
5965     }
5966   }
5967 
5968   return OMPLinearClause::Create(Context, StartLoc, LParenLoc, ColonLoc, EndLoc,
5969                                  Vars, Inits, StepExpr, CalcStepExpr);
5970 }
5971 
5972 static bool FinishOpenMPLinearClause(OMPLinearClause &Clause, DeclRefExpr *IV,
5973                                      Expr *NumIterations, Sema &SemaRef,
5974                                      Scope *S) {
5975   // Walk the vars and build update/final expressions for the CodeGen.
5976   SmallVector<Expr *, 8> Updates;
5977   SmallVector<Expr *, 8> Finals;
5978   Expr *Step = Clause.getStep();
5979   Expr *CalcStep = Clause.getCalcStep();
5980   // OpenMP [2.14.3.7, linear clause]
5981   // If linear-step is not specified it is assumed to be 1.
5982   if (Step == nullptr)
5983     Step = SemaRef.ActOnIntegerConstant(SourceLocation(), 1).get();
5984   else if (CalcStep)
5985     Step = cast<BinaryOperator>(CalcStep)->getLHS();
5986   bool HasErrors = false;
5987   auto CurInit = Clause.inits().begin();
5988   for (auto &RefExpr : Clause.varlists()) {
5989     Expr *InitExpr = *CurInit;
5990 
5991     // Build privatized reference to the current linear var.
5992     auto DE = cast<DeclRefExpr>(RefExpr);
5993     auto PrivateRef =
5994         buildDeclRefExpr(SemaRef, cast<VarDecl>(DE->getDecl()),
5995                          DE->getType().getUnqualifiedType(), DE->getExprLoc(),
5996                          /*RefersToCapture=*/true);
5997 
5998     // Build update: Var = InitExpr + IV * Step
5999     ExprResult Update =
6000         BuildCounterUpdate(SemaRef, S, RefExpr->getExprLoc(), PrivateRef,
6001                            InitExpr, IV, Step, /* Subtract */ false);
6002     Update = SemaRef.ActOnFinishFullExpr(Update.get());
6003 
6004     // Build final: Var = InitExpr + NumIterations * Step
6005     ExprResult Final =
6006         BuildCounterUpdate(SemaRef, S, RefExpr->getExprLoc(), PrivateRef,
6007                            InitExpr, NumIterations, Step, /* Subtract */ false);
6008     Final = SemaRef.ActOnFinishFullExpr(Final.get());
6009     if (!Update.isUsable() || !Final.isUsable()) {
6010       Updates.push_back(nullptr);
6011       Finals.push_back(nullptr);
6012       HasErrors = true;
6013     } else {
6014       Updates.push_back(Update.get());
6015       Finals.push_back(Final.get());
6016     }
6017     ++CurInit;
6018   }
6019   Clause.setUpdates(Updates);
6020   Clause.setFinals(Finals);
6021   return HasErrors;
6022 }
6023 
6024 OMPClause *Sema::ActOnOpenMPAlignedClause(
6025     ArrayRef<Expr *> VarList, Expr *Alignment, SourceLocation StartLoc,
6026     SourceLocation LParenLoc, SourceLocation ColonLoc, SourceLocation EndLoc) {
6027 
6028   SmallVector<Expr *, 8> Vars;
6029   for (auto &RefExpr : VarList) {
6030     assert(RefExpr && "NULL expr in OpenMP aligned clause.");
6031     if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
6032       // It will be analyzed later.
6033       Vars.push_back(RefExpr);
6034       continue;
6035     }
6036 
6037     SourceLocation ELoc = RefExpr->getExprLoc();
6038     // OpenMP [2.1, C/C++]
6039     //  A list item is a variable name.
6040     DeclRefExpr *DE = dyn_cast<DeclRefExpr>(RefExpr);
6041     if (!DE || !isa<VarDecl>(DE->getDecl())) {
6042       Diag(ELoc, diag::err_omp_expected_var_name) << RefExpr->getSourceRange();
6043       continue;
6044     }
6045 
6046     VarDecl *VD = cast<VarDecl>(DE->getDecl());
6047 
6048     // OpenMP  [2.8.1, simd construct, Restrictions]
6049     // The type of list items appearing in the aligned clause must be
6050     // array, pointer, reference to array, or reference to pointer.
6051     QualType QType = VD->getType();
6052     QType = QType.getNonReferenceType().getUnqualifiedType().getCanonicalType();
6053     const Type *Ty = QType.getTypePtrOrNull();
6054     if (!Ty || (!Ty->isDependentType() && !Ty->isArrayType() &&
6055                 !Ty->isPointerType())) {
6056       Diag(ELoc, diag::err_omp_aligned_expected_array_or_ptr)
6057           << QType << getLangOpts().CPlusPlus << RefExpr->getSourceRange();
6058       bool IsDecl =
6059           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
6060       Diag(VD->getLocation(),
6061            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
6062           << VD;
6063       continue;
6064     }
6065 
6066     // OpenMP  [2.8.1, simd construct, Restrictions]
6067     // A list-item cannot appear in more than one aligned clause.
6068     if (DeclRefExpr *PrevRef = DSAStack->addUniqueAligned(VD, DE)) {
6069       Diag(ELoc, diag::err_omp_aligned_twice) << RefExpr->getSourceRange();
6070       Diag(PrevRef->getExprLoc(), diag::note_omp_explicit_dsa)
6071           << getOpenMPClauseName(OMPC_aligned);
6072       continue;
6073     }
6074 
6075     Vars.push_back(DE);
6076   }
6077 
6078   // OpenMP [2.8.1, simd construct, Description]
6079   // The parameter of the aligned clause, alignment, must be a constant
6080   // positive integer expression.
6081   // If no optional parameter is specified, implementation-defined default
6082   // alignments for SIMD instructions on the target platforms are assumed.
6083   if (Alignment != nullptr) {
6084     ExprResult AlignResult =
6085         VerifyPositiveIntegerConstantInClause(Alignment, OMPC_aligned);
6086     if (AlignResult.isInvalid())
6087       return nullptr;
6088     Alignment = AlignResult.get();
6089   }
6090   if (Vars.empty())
6091     return nullptr;
6092 
6093   return OMPAlignedClause::Create(Context, StartLoc, LParenLoc, ColonLoc,
6094                                   EndLoc, Vars, Alignment);
6095 }
6096 
6097 OMPClause *Sema::ActOnOpenMPCopyinClause(ArrayRef<Expr *> VarList,
6098                                          SourceLocation StartLoc,
6099                                          SourceLocation LParenLoc,
6100                                          SourceLocation EndLoc) {
6101   SmallVector<Expr *, 8> Vars;
6102   SmallVector<Expr *, 8> SrcExprs;
6103   SmallVector<Expr *, 8> DstExprs;
6104   SmallVector<Expr *, 8> AssignmentOps;
6105   for (auto &RefExpr : VarList) {
6106     assert(RefExpr && "NULL expr in OpenMP copyin clause.");
6107     if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
6108       // It will be analyzed later.
6109       Vars.push_back(RefExpr);
6110       SrcExprs.push_back(nullptr);
6111       DstExprs.push_back(nullptr);
6112       AssignmentOps.push_back(nullptr);
6113       continue;
6114     }
6115 
6116     SourceLocation ELoc = RefExpr->getExprLoc();
6117     // OpenMP [2.1, C/C++]
6118     //  A list item is a variable name.
6119     // OpenMP  [2.14.4.1, Restrictions, p.1]
6120     //  A list item that appears in a copyin clause must be threadprivate.
6121     DeclRefExpr *DE = dyn_cast<DeclRefExpr>(RefExpr);
6122     if (!DE || !isa<VarDecl>(DE->getDecl())) {
6123       Diag(ELoc, diag::err_omp_expected_var_name) << RefExpr->getSourceRange();
6124       continue;
6125     }
6126 
6127     Decl *D = DE->getDecl();
6128     VarDecl *VD = cast<VarDecl>(D);
6129 
6130     QualType Type = VD->getType();
6131     if (Type->isDependentType() || Type->isInstantiationDependentType()) {
6132       // It will be analyzed later.
6133       Vars.push_back(DE);
6134       SrcExprs.push_back(nullptr);
6135       DstExprs.push_back(nullptr);
6136       AssignmentOps.push_back(nullptr);
6137       continue;
6138     }
6139 
6140     // OpenMP [2.14.4.1, Restrictions, C/C++, p.1]
6141     //  A list item that appears in a copyin clause must be threadprivate.
6142     if (!DSAStack->isThreadPrivate(VD)) {
6143       Diag(ELoc, diag::err_omp_required_access)
6144           << getOpenMPClauseName(OMPC_copyin)
6145           << getOpenMPDirectiveName(OMPD_threadprivate);
6146       continue;
6147     }
6148 
6149     // OpenMP [2.14.4.1, Restrictions, C/C++, p.2]
6150     //  A variable of class type (or array thereof) that appears in a
6151     //  copyin clause requires an accessible, unambiguous copy assignment
6152     //  operator for the class type.
6153     auto ElemType = Context.getBaseElementType(Type).getNonReferenceType();
6154     auto *SrcVD = buildVarDecl(*this, DE->getLocStart(),
6155                                ElemType.getUnqualifiedType(), ".copyin.src");
6156     auto *PseudoSrcExpr = buildDeclRefExpr(
6157         *this, SrcVD, ElemType.getUnqualifiedType(), DE->getExprLoc());
6158     auto *DstVD =
6159         buildVarDecl(*this, DE->getLocStart(), ElemType, ".copyin.dst");
6160     auto *PseudoDstExpr =
6161         buildDeclRefExpr(*this, DstVD, ElemType, DE->getExprLoc());
6162     // For arrays generate assignment operation for single element and replace
6163     // it by the original array element in CodeGen.
6164     auto AssignmentOp = BuildBinOp(/*S=*/nullptr, DE->getExprLoc(), BO_Assign,
6165                                    PseudoDstExpr, PseudoSrcExpr);
6166     if (AssignmentOp.isInvalid())
6167       continue;
6168     AssignmentOp = ActOnFinishFullExpr(AssignmentOp.get(), DE->getExprLoc(),
6169                                        /*DiscardedValue=*/true);
6170     if (AssignmentOp.isInvalid())
6171       continue;
6172 
6173     DSAStack->addDSA(VD, DE, OMPC_copyin);
6174     Vars.push_back(DE);
6175     SrcExprs.push_back(PseudoSrcExpr);
6176     DstExprs.push_back(PseudoDstExpr);
6177     AssignmentOps.push_back(AssignmentOp.get());
6178   }
6179 
6180   if (Vars.empty())
6181     return nullptr;
6182 
6183   return OMPCopyinClause::Create(Context, StartLoc, LParenLoc, EndLoc, Vars,
6184                                  SrcExprs, DstExprs, AssignmentOps);
6185 }
6186 
6187 OMPClause *Sema::ActOnOpenMPCopyprivateClause(ArrayRef<Expr *> VarList,
6188                                               SourceLocation StartLoc,
6189                                               SourceLocation LParenLoc,
6190                                               SourceLocation EndLoc) {
6191   SmallVector<Expr *, 8> Vars;
6192   SmallVector<Expr *, 8> SrcExprs;
6193   SmallVector<Expr *, 8> DstExprs;
6194   SmallVector<Expr *, 8> AssignmentOps;
6195   for (auto &RefExpr : VarList) {
6196     assert(RefExpr && "NULL expr in OpenMP copyprivate clause.");
6197     if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
6198       // It will be analyzed later.
6199       Vars.push_back(RefExpr);
6200       SrcExprs.push_back(nullptr);
6201       DstExprs.push_back(nullptr);
6202       AssignmentOps.push_back(nullptr);
6203       continue;
6204     }
6205 
6206     SourceLocation ELoc = RefExpr->getExprLoc();
6207     // OpenMP [2.1, C/C++]
6208     //  A list item is a variable name.
6209     // OpenMP  [2.14.4.1, Restrictions, p.1]
6210     //  A list item that appears in a copyin clause must be threadprivate.
6211     DeclRefExpr *DE = dyn_cast<DeclRefExpr>(RefExpr);
6212     if (!DE || !isa<VarDecl>(DE->getDecl())) {
6213       Diag(ELoc, diag::err_omp_expected_var_name) << RefExpr->getSourceRange();
6214       continue;
6215     }
6216 
6217     Decl *D = DE->getDecl();
6218     VarDecl *VD = cast<VarDecl>(D);
6219 
6220     QualType Type = VD->getType();
6221     if (Type->isDependentType() || Type->isInstantiationDependentType()) {
6222       // It will be analyzed later.
6223       Vars.push_back(DE);
6224       SrcExprs.push_back(nullptr);
6225       DstExprs.push_back(nullptr);
6226       AssignmentOps.push_back(nullptr);
6227       continue;
6228     }
6229 
6230     // OpenMP [2.14.4.2, Restrictions, p.2]
6231     //  A list item that appears in a copyprivate clause may not appear in a
6232     //  private or firstprivate clause on the single construct.
6233     if (!DSAStack->isThreadPrivate(VD)) {
6234       auto DVar = DSAStack->getTopDSA(VD, false);
6235       if (DVar.CKind != OMPC_unknown && DVar.CKind != OMPC_copyprivate &&
6236           DVar.RefExpr) {
6237         Diag(ELoc, diag::err_omp_wrong_dsa)
6238             << getOpenMPClauseName(DVar.CKind)
6239             << getOpenMPClauseName(OMPC_copyprivate);
6240         ReportOriginalDSA(*this, DSAStack, VD, DVar);
6241         continue;
6242       }
6243 
6244       // OpenMP [2.11.4.2, Restrictions, p.1]
6245       //  All list items that appear in a copyprivate clause must be either
6246       //  threadprivate or private in the enclosing context.
6247       if (DVar.CKind == OMPC_unknown) {
6248         DVar = DSAStack->getImplicitDSA(VD, false);
6249         if (DVar.CKind == OMPC_shared) {
6250           Diag(ELoc, diag::err_omp_required_access)
6251               << getOpenMPClauseName(OMPC_copyprivate)
6252               << "threadprivate or private in the enclosing context";
6253           ReportOriginalDSA(*this, DSAStack, VD, DVar);
6254           continue;
6255         }
6256       }
6257     }
6258 
6259     // Variably modified types are not supported.
6260     if (!Type->isAnyPointerType() && Type->isVariablyModifiedType()) {
6261       Diag(ELoc, diag::err_omp_variably_modified_type_not_supported)
6262           << getOpenMPClauseName(OMPC_copyprivate) << Type
6263           << getOpenMPDirectiveName(DSAStack->getCurrentDirective());
6264       bool IsDecl =
6265           VD->isThisDeclarationADefinition(Context) == VarDecl::DeclarationOnly;
6266       Diag(VD->getLocation(),
6267            IsDecl ? diag::note_previous_decl : diag::note_defined_here)
6268           << VD;
6269       continue;
6270     }
6271 
6272     // OpenMP [2.14.4.1, Restrictions, C/C++, p.2]
6273     //  A variable of class type (or array thereof) that appears in a
6274     //  copyin clause requires an accessible, unambiguous copy assignment
6275     //  operator for the class type.
6276     Type = Context.getBaseElementType(Type).getUnqualifiedType();
6277     auto *SrcVD =
6278         buildVarDecl(*this, DE->getLocStart(), Type, ".copyprivate.src");
6279     auto *PseudoSrcExpr =
6280         buildDeclRefExpr(*this, SrcVD, Type, DE->getExprLoc());
6281     auto *DstVD =
6282         buildVarDecl(*this, DE->getLocStart(), Type, ".copyprivate.dst");
6283     auto *PseudoDstExpr =
6284         buildDeclRefExpr(*this, DstVD, Type, DE->getExprLoc());
6285     auto AssignmentOp = BuildBinOp(/*S=*/nullptr, DE->getExprLoc(), BO_Assign,
6286                                    PseudoDstExpr, PseudoSrcExpr);
6287     if (AssignmentOp.isInvalid())
6288       continue;
6289     AssignmentOp = ActOnFinishFullExpr(AssignmentOp.get(), DE->getExprLoc(),
6290                                        /*DiscardedValue=*/true);
6291     if (AssignmentOp.isInvalid())
6292       continue;
6293 
6294     // No need to mark vars as copyprivate, they are already threadprivate or
6295     // implicitly private.
6296     Vars.push_back(DE);
6297     SrcExprs.push_back(PseudoSrcExpr);
6298     DstExprs.push_back(PseudoDstExpr);
6299     AssignmentOps.push_back(AssignmentOp.get());
6300   }
6301 
6302   if (Vars.empty())
6303     return nullptr;
6304 
6305   return OMPCopyprivateClause::Create(Context, StartLoc, LParenLoc, EndLoc,
6306                                       Vars, SrcExprs, DstExprs, AssignmentOps);
6307 }
6308 
6309 OMPClause *Sema::ActOnOpenMPFlushClause(ArrayRef<Expr *> VarList,
6310                                         SourceLocation StartLoc,
6311                                         SourceLocation LParenLoc,
6312                                         SourceLocation EndLoc) {
6313   if (VarList.empty())
6314     return nullptr;
6315 
6316   return OMPFlushClause::Create(Context, StartLoc, LParenLoc, EndLoc, VarList);
6317 }
6318 
6319