1 //===-- CodeGenFunction.h - Per-Function state for LLVM CodeGen -*- C++ -*-===//
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 //
10 // This is the internal per-function state used for llvm translation.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENFUNCTION_H
15 #define LLVM_CLANG_LIB_CODEGEN_CODEGENFUNCTION_H
16 
17 #include "CGBuilder.h"
18 #include "CGDebugInfo.h"
19 #include "CGLoopInfo.h"
20 #include "CGValue.h"
21 #include "CodeGenModule.h"
22 #include "CodeGenPGO.h"
23 #include "EHScopeStack.h"
24 #include "VarBypassDetector.h"
25 #include "clang/AST/CharUnits.h"
26 #include "clang/AST/ExprCXX.h"
27 #include "clang/AST/ExprObjC.h"
28 #include "clang/AST/ExprOpenMP.h"
29 #include "clang/AST/Type.h"
30 #include "clang/Basic/ABI.h"
31 #include "clang/Basic/CapturedStmt.h"
32 #include "clang/Basic/OpenMPKinds.h"
33 #include "clang/Basic/TargetInfo.h"
34 #include "clang/Frontend/CodeGenOptions.h"
35 #include "llvm/ADT/ArrayRef.h"
36 #include "llvm/ADT/DenseMap.h"
37 #include "llvm/ADT/SmallVector.h"
38 #include "llvm/IR/ValueHandle.h"
39 #include "llvm/Support/Debug.h"
40 #include "llvm/Transforms/Utils/SanitizerStats.h"
41 
42 namespace llvm {
43 class BasicBlock;
44 class LLVMContext;
45 class MDNode;
46 class Module;
47 class SwitchInst;
48 class Twine;
49 class Value;
50 class CallSite;
51 }
52 
53 namespace clang {
54 class ASTContext;
55 class BlockDecl;
56 class CXXDestructorDecl;
57 class CXXForRangeStmt;
58 class CXXTryStmt;
59 class Decl;
60 class LabelDecl;
61 class EnumConstantDecl;
62 class FunctionDecl;
63 class FunctionProtoType;
64 class LabelStmt;
65 class ObjCContainerDecl;
66 class ObjCInterfaceDecl;
67 class ObjCIvarDecl;
68 class ObjCMethodDecl;
69 class ObjCImplementationDecl;
70 class ObjCPropertyImplDecl;
71 class TargetInfo;
72 class VarDecl;
73 class ObjCForCollectionStmt;
74 class ObjCAtTryStmt;
75 class ObjCAtThrowStmt;
76 class ObjCAtSynchronizedStmt;
77 class ObjCAutoreleasePoolStmt;
78 
79 namespace CodeGen {
80 class CodeGenTypes;
81 class CGCallee;
82 class CGFunctionInfo;
83 class CGRecordLayout;
84 class CGBlockInfo;
85 class CGCXXABI;
86 class BlockByrefHelpers;
87 class BlockByrefInfo;
88 class BlockFlags;
89 class BlockFieldFlags;
90 class RegionCodeGenTy;
91 class TargetCodeGenInfo;
92 struct OMPTaskDataTy;
93 struct CGCoroData;
94 
95 /// The kind of evaluation to perform on values of a particular
96 /// type.  Basically, is the code in CGExprScalar, CGExprComplex, or
97 /// CGExprAgg?
98 ///
99 /// TODO: should vectors maybe be split out into their own thing?
100 enum TypeEvaluationKind {
101   TEK_Scalar,
102   TEK_Complex,
103   TEK_Aggregate
104 };
105 
106 /// CodeGenFunction - This class organizes the per-function state that is used
107 /// while generating LLVM code.
108 class CodeGenFunction : public CodeGenTypeCache {
109   CodeGenFunction(const CodeGenFunction &) = delete;
110   void operator=(const CodeGenFunction &) = delete;
111 
112   friend class CGCXXABI;
113 public:
114   /// A jump destination is an abstract label, branching to which may
115   /// require a jump out through normal cleanups.
116   struct JumpDest {
117     JumpDest() : Block(nullptr), ScopeDepth(), Index(0) {}
118     JumpDest(llvm::BasicBlock *Block,
119              EHScopeStack::stable_iterator Depth,
120              unsigned Index)
121       : Block(Block), ScopeDepth(Depth), Index(Index) {}
122 
123     bool isValid() const { return Block != nullptr; }
124     llvm::BasicBlock *getBlock() const { return Block; }
125     EHScopeStack::stable_iterator getScopeDepth() const { return ScopeDepth; }
126     unsigned getDestIndex() const { return Index; }
127 
128     // This should be used cautiously.
129     void setScopeDepth(EHScopeStack::stable_iterator depth) {
130       ScopeDepth = depth;
131     }
132 
133   private:
134     llvm::BasicBlock *Block;
135     EHScopeStack::stable_iterator ScopeDepth;
136     unsigned Index;
137   };
138 
139   CodeGenModule &CGM;  // Per-module state.
140   const TargetInfo &Target;
141 
142   typedef std::pair<llvm::Value *, llvm::Value *> ComplexPairTy;
143   LoopInfoStack LoopStack;
144   CGBuilderTy Builder;
145 
146   // Stores variables for which we can't generate correct lifetime markers
147   // because of jumps.
148   VarBypassDetector Bypasses;
149 
150   /// \brief CGBuilder insert helper. This function is called after an
151   /// instruction is created using Builder.
152   void InsertHelper(llvm::Instruction *I, const llvm::Twine &Name,
153                     llvm::BasicBlock *BB,
154                     llvm::BasicBlock::iterator InsertPt) const;
155 
156   /// CurFuncDecl - Holds the Decl for the current outermost
157   /// non-closure context.
158   const Decl *CurFuncDecl;
159   /// CurCodeDecl - This is the inner-most code context, which includes blocks.
160   const Decl *CurCodeDecl;
161   const CGFunctionInfo *CurFnInfo;
162   QualType FnRetTy;
163   llvm::Function *CurFn;
164 
165   // Holds coroutine data if the current function is a coroutine. We use a
166   // wrapper to manage its lifetime, so that we don't have to define CGCoroData
167   // in this header.
168   struct CGCoroInfo {
169     std::unique_ptr<CGCoroData> Data;
170     CGCoroInfo();
171     ~CGCoroInfo();
172   };
173   CGCoroInfo CurCoro;
174 
175   /// CurGD - The GlobalDecl for the current function being compiled.
176   GlobalDecl CurGD;
177 
178   /// PrologueCleanupDepth - The cleanup depth enclosing all the
179   /// cleanups associated with the parameters.
180   EHScopeStack::stable_iterator PrologueCleanupDepth;
181 
182   /// ReturnBlock - Unified return block.
183   JumpDest ReturnBlock;
184 
185   /// ReturnValue - The temporary alloca to hold the return
186   /// value. This is invalid iff the function has no return value.
187   Address ReturnValue;
188 
189   /// AllocaInsertPoint - This is an instruction in the entry block before which
190   /// we prefer to insert allocas.
191   llvm::AssertingVH<llvm::Instruction> AllocaInsertPt;
192 
193   /// \brief API for captured statement code generation.
194   class CGCapturedStmtInfo {
195   public:
196     explicit CGCapturedStmtInfo(CapturedRegionKind K = CR_Default)
197         : Kind(K), ThisValue(nullptr), CXXThisFieldDecl(nullptr) {}
198     explicit CGCapturedStmtInfo(const CapturedStmt &S,
199                                 CapturedRegionKind K = CR_Default)
200       : Kind(K), ThisValue(nullptr), CXXThisFieldDecl(nullptr) {
201 
202       RecordDecl::field_iterator Field =
203         S.getCapturedRecordDecl()->field_begin();
204       for (CapturedStmt::const_capture_iterator I = S.capture_begin(),
205                                                 E = S.capture_end();
206            I != E; ++I, ++Field) {
207         if (I->capturesThis())
208           CXXThisFieldDecl = *Field;
209         else if (I->capturesVariable())
210           CaptureFields[I->getCapturedVar()] = *Field;
211         else if (I->capturesVariableByCopy())
212           CaptureFields[I->getCapturedVar()] = *Field;
213       }
214     }
215 
216     virtual ~CGCapturedStmtInfo();
217 
218     CapturedRegionKind getKind() const { return Kind; }
219 
220     virtual void setContextValue(llvm::Value *V) { ThisValue = V; }
221     // \brief Retrieve the value of the context parameter.
222     virtual llvm::Value *getContextValue() const { return ThisValue; }
223 
224     /// \brief Lookup the captured field decl for a variable.
225     virtual const FieldDecl *lookup(const VarDecl *VD) const {
226       return CaptureFields.lookup(VD);
227     }
228 
229     bool isCXXThisExprCaptured() const { return getThisFieldDecl() != nullptr; }
230     virtual FieldDecl *getThisFieldDecl() const { return CXXThisFieldDecl; }
231 
232     static bool classof(const CGCapturedStmtInfo *) {
233       return true;
234     }
235 
236     /// \brief Emit the captured statement body.
237     virtual void EmitBody(CodeGenFunction &CGF, const Stmt *S) {
238       CGF.incrementProfileCounter(S);
239       CGF.EmitStmt(S);
240     }
241 
242     /// \brief Get the name of the capture helper.
243     virtual StringRef getHelperName() const { return "__captured_stmt"; }
244 
245   private:
246     /// \brief The kind of captured statement being generated.
247     CapturedRegionKind Kind;
248 
249     /// \brief Keep the map between VarDecl and FieldDecl.
250     llvm::SmallDenseMap<const VarDecl *, FieldDecl *> CaptureFields;
251 
252     /// \brief The base address of the captured record, passed in as the first
253     /// argument of the parallel region function.
254     llvm::Value *ThisValue;
255 
256     /// \brief Captured 'this' type.
257     FieldDecl *CXXThisFieldDecl;
258   };
259   CGCapturedStmtInfo *CapturedStmtInfo;
260 
261   /// \brief RAII for correct setting/restoring of CapturedStmtInfo.
262   class CGCapturedStmtRAII {
263   private:
264     CodeGenFunction &CGF;
265     CGCapturedStmtInfo *PrevCapturedStmtInfo;
266   public:
267     CGCapturedStmtRAII(CodeGenFunction &CGF,
268                        CGCapturedStmtInfo *NewCapturedStmtInfo)
269         : CGF(CGF), PrevCapturedStmtInfo(CGF.CapturedStmtInfo) {
270       CGF.CapturedStmtInfo = NewCapturedStmtInfo;
271     }
272     ~CGCapturedStmtRAII() { CGF.CapturedStmtInfo = PrevCapturedStmtInfo; }
273   };
274 
275   /// \brief Sanitizers enabled for this function.
276   SanitizerSet SanOpts;
277 
278   /// \brief True if CodeGen currently emits code implementing sanitizer checks.
279   bool IsSanitizerScope;
280 
281   /// \brief RAII object to set/unset CodeGenFunction::IsSanitizerScope.
282   class SanitizerScope {
283     CodeGenFunction *CGF;
284   public:
285     SanitizerScope(CodeGenFunction *CGF);
286     ~SanitizerScope();
287   };
288 
289   /// In C++, whether we are code generating a thunk.  This controls whether we
290   /// should emit cleanups.
291   bool CurFuncIsThunk;
292 
293   /// In ARC, whether we should autorelease the return value.
294   bool AutoreleaseResult;
295 
296   /// Whether we processed a Microsoft-style asm block during CodeGen. These can
297   /// potentially set the return value.
298   bool SawAsmBlock;
299 
300   const FunctionDecl *CurSEHParent = nullptr;
301 
302   /// True if the current function is an outlined SEH helper. This can be a
303   /// finally block or filter expression.
304   bool IsOutlinedSEHHelper;
305 
306   const CodeGen::CGBlockInfo *BlockInfo;
307   llvm::Value *BlockPointer;
308 
309   llvm::DenseMap<const VarDecl *, FieldDecl *> LambdaCaptureFields;
310   FieldDecl *LambdaThisCaptureField;
311 
312   /// \brief A mapping from NRVO variables to the flags used to indicate
313   /// when the NRVO has been applied to this variable.
314   llvm::DenseMap<const VarDecl *, llvm::Value *> NRVOFlags;
315 
316   EHScopeStack EHStack;
317   llvm::SmallVector<char, 256> LifetimeExtendedCleanupStack;
318   llvm::SmallVector<const JumpDest *, 2> SEHTryEpilogueStack;
319 
320   llvm::Instruction *CurrentFuncletPad = nullptr;
321 
322   class CallLifetimeEnd final : public EHScopeStack::Cleanup {
323     llvm::Value *Addr;
324     llvm::Value *Size;
325 
326   public:
327     CallLifetimeEnd(Address addr, llvm::Value *size)
328         : Addr(addr.getPointer()), Size(size) {}
329 
330     void Emit(CodeGenFunction &CGF, Flags flags) override {
331       CGF.EmitLifetimeEnd(Size, Addr);
332     }
333   };
334 
335   /// Header for data within LifetimeExtendedCleanupStack.
336   struct LifetimeExtendedCleanupHeader {
337     /// The size of the following cleanup object.
338     unsigned Size;
339     /// The kind of cleanup to push: a value from the CleanupKind enumeration.
340     CleanupKind Kind;
341 
342     size_t getSize() const { return Size; }
343     CleanupKind getKind() const { return Kind; }
344   };
345 
346   /// i32s containing the indexes of the cleanup destinations.
347   llvm::AllocaInst *NormalCleanupDest;
348 
349   unsigned NextCleanupDestIndex;
350 
351   /// FirstBlockInfo - The head of a singly-linked-list of block layouts.
352   CGBlockInfo *FirstBlockInfo;
353 
354   /// EHResumeBlock - Unified block containing a call to llvm.eh.resume.
355   llvm::BasicBlock *EHResumeBlock;
356 
357   /// The exception slot.  All landing pads write the current exception pointer
358   /// into this alloca.
359   llvm::Value *ExceptionSlot;
360 
361   /// The selector slot.  Under the MandatoryCleanup model, all landing pads
362   /// write the current selector value into this alloca.
363   llvm::AllocaInst *EHSelectorSlot;
364 
365   /// A stack of exception code slots. Entering an __except block pushes a slot
366   /// on the stack and leaving pops one. The __exception_code() intrinsic loads
367   /// a value from the top of the stack.
368   SmallVector<Address, 1> SEHCodeSlotStack;
369 
370   /// Value returned by __exception_info intrinsic.
371   llvm::Value *SEHInfo = nullptr;
372 
373   /// Emits a landing pad for the current EH stack.
374   llvm::BasicBlock *EmitLandingPad();
375 
376   llvm::BasicBlock *getInvokeDestImpl();
377 
378   template <class T>
379   typename DominatingValue<T>::saved_type saveValueInCond(T value) {
380     return DominatingValue<T>::save(*this, value);
381   }
382 
383 public:
384   /// ObjCEHValueStack - Stack of Objective-C exception values, used for
385   /// rethrows.
386   SmallVector<llvm::Value*, 8> ObjCEHValueStack;
387 
388   /// A class controlling the emission of a finally block.
389   class FinallyInfo {
390     /// Where the catchall's edge through the cleanup should go.
391     JumpDest RethrowDest;
392 
393     /// A function to call to enter the catch.
394     llvm::Constant *BeginCatchFn;
395 
396     /// An i1 variable indicating whether or not the @finally is
397     /// running for an exception.
398     llvm::AllocaInst *ForEHVar;
399 
400     /// An i8* variable into which the exception pointer to rethrow
401     /// has been saved.
402     llvm::AllocaInst *SavedExnVar;
403 
404   public:
405     void enter(CodeGenFunction &CGF, const Stmt *Finally,
406                llvm::Constant *beginCatchFn, llvm::Constant *endCatchFn,
407                llvm::Constant *rethrowFn);
408     void exit(CodeGenFunction &CGF);
409   };
410 
411   /// Returns true inside SEH __try blocks.
412   bool isSEHTryScope() const { return !SEHTryEpilogueStack.empty(); }
413 
414   /// Returns true while emitting a cleanuppad.
415   bool isCleanupPadScope() const {
416     return CurrentFuncletPad && isa<llvm::CleanupPadInst>(CurrentFuncletPad);
417   }
418 
419   /// pushFullExprCleanup - Push a cleanup to be run at the end of the
420   /// current full-expression.  Safe against the possibility that
421   /// we're currently inside a conditionally-evaluated expression.
422   template <class T, class... As>
423   void pushFullExprCleanup(CleanupKind kind, As... A) {
424     // If we're not in a conditional branch, or if none of the
425     // arguments requires saving, then use the unconditional cleanup.
426     if (!isInConditionalBranch())
427       return EHStack.pushCleanup<T>(kind, A...);
428 
429     // Stash values in a tuple so we can guarantee the order of saves.
430     typedef std::tuple<typename DominatingValue<As>::saved_type...> SavedTuple;
431     SavedTuple Saved{saveValueInCond(A)...};
432 
433     typedef EHScopeStack::ConditionalCleanup<T, As...> CleanupType;
434     EHStack.pushCleanupTuple<CleanupType>(kind, Saved);
435     initFullExprCleanup();
436   }
437 
438   /// \brief Queue a cleanup to be pushed after finishing the current
439   /// full-expression.
440   template <class T, class... As>
441   void pushCleanupAfterFullExpr(CleanupKind Kind, As... A) {
442     assert(!isInConditionalBranch() && "can't defer conditional cleanup");
443 
444     LifetimeExtendedCleanupHeader Header = { sizeof(T), Kind };
445 
446     size_t OldSize = LifetimeExtendedCleanupStack.size();
447     LifetimeExtendedCleanupStack.resize(
448         LifetimeExtendedCleanupStack.size() + sizeof(Header) + Header.Size);
449 
450     static_assert(sizeof(Header) % alignof(T) == 0,
451                   "Cleanup will be allocated on misaligned address");
452     char *Buffer = &LifetimeExtendedCleanupStack[OldSize];
453     new (Buffer) LifetimeExtendedCleanupHeader(Header);
454     new (Buffer + sizeof(Header)) T(A...);
455   }
456 
457   /// Set up the last cleaup that was pushed as a conditional
458   /// full-expression cleanup.
459   void initFullExprCleanup();
460 
461   /// PushDestructorCleanup - Push a cleanup to call the
462   /// complete-object destructor of an object of the given type at the
463   /// given address.  Does nothing if T is not a C++ class type with a
464   /// non-trivial destructor.
465   void PushDestructorCleanup(QualType T, Address Addr);
466 
467   /// PushDestructorCleanup - Push a cleanup to call the
468   /// complete-object variant of the given destructor on the object at
469   /// the given address.
470   void PushDestructorCleanup(const CXXDestructorDecl *Dtor, Address Addr);
471 
472   /// PopCleanupBlock - Will pop the cleanup entry on the stack and
473   /// process all branch fixups.
474   void PopCleanupBlock(bool FallThroughIsBranchThrough = false);
475 
476   /// DeactivateCleanupBlock - Deactivates the given cleanup block.
477   /// The block cannot be reactivated.  Pops it if it's the top of the
478   /// stack.
479   ///
480   /// \param DominatingIP - An instruction which is known to
481   ///   dominate the current IP (if set) and which lies along
482   ///   all paths of execution between the current IP and the
483   ///   the point at which the cleanup comes into scope.
484   void DeactivateCleanupBlock(EHScopeStack::stable_iterator Cleanup,
485                               llvm::Instruction *DominatingIP);
486 
487   /// ActivateCleanupBlock - Activates an initially-inactive cleanup.
488   /// Cannot be used to resurrect a deactivated cleanup.
489   ///
490   /// \param DominatingIP - An instruction which is known to
491   ///   dominate the current IP (if set) and which lies along
492   ///   all paths of execution between the current IP and the
493   ///   the point at which the cleanup comes into scope.
494   void ActivateCleanupBlock(EHScopeStack::stable_iterator Cleanup,
495                             llvm::Instruction *DominatingIP);
496 
497   /// \brief Enters a new scope for capturing cleanups, all of which
498   /// will be executed once the scope is exited.
499   class RunCleanupsScope {
500     EHScopeStack::stable_iterator CleanupStackDepth;
501     size_t LifetimeExtendedCleanupStackSize;
502     bool OldDidCallStackSave;
503   protected:
504     bool PerformCleanup;
505   private:
506 
507     RunCleanupsScope(const RunCleanupsScope &) = delete;
508     void operator=(const RunCleanupsScope &) = delete;
509 
510   protected:
511     CodeGenFunction& CGF;
512 
513   public:
514     /// \brief Enter a new cleanup scope.
515     explicit RunCleanupsScope(CodeGenFunction &CGF)
516       : PerformCleanup(true), CGF(CGF)
517     {
518       CleanupStackDepth = CGF.EHStack.stable_begin();
519       LifetimeExtendedCleanupStackSize =
520           CGF.LifetimeExtendedCleanupStack.size();
521       OldDidCallStackSave = CGF.DidCallStackSave;
522       CGF.DidCallStackSave = false;
523     }
524 
525     /// \brief Exit this cleanup scope, emitting any accumulated
526     /// cleanups.
527     ~RunCleanupsScope() {
528       if (PerformCleanup) {
529         CGF.DidCallStackSave = OldDidCallStackSave;
530         CGF.PopCleanupBlocks(CleanupStackDepth,
531                              LifetimeExtendedCleanupStackSize);
532       }
533     }
534 
535     /// \brief Determine whether this scope requires any cleanups.
536     bool requiresCleanups() const {
537       return CGF.EHStack.stable_begin() != CleanupStackDepth;
538     }
539 
540     /// \brief Force the emission of cleanups now, instead of waiting
541     /// until this object is destroyed.
542     void ForceCleanup() {
543       assert(PerformCleanup && "Already forced cleanup");
544       CGF.DidCallStackSave = OldDidCallStackSave;
545       CGF.PopCleanupBlocks(CleanupStackDepth,
546                            LifetimeExtendedCleanupStackSize);
547       PerformCleanup = false;
548     }
549   };
550 
551   class LexicalScope : public RunCleanupsScope {
552     SourceRange Range;
553     SmallVector<const LabelDecl*, 4> Labels;
554     LexicalScope *ParentScope;
555 
556     LexicalScope(const LexicalScope &) = delete;
557     void operator=(const LexicalScope &) = delete;
558 
559   public:
560     /// \brief Enter a new cleanup scope.
561     explicit LexicalScope(CodeGenFunction &CGF, SourceRange Range)
562       : RunCleanupsScope(CGF), Range(Range), ParentScope(CGF.CurLexicalScope) {
563       CGF.CurLexicalScope = this;
564       if (CGDebugInfo *DI = CGF.getDebugInfo())
565         DI->EmitLexicalBlockStart(CGF.Builder, Range.getBegin());
566     }
567 
568     void addLabel(const LabelDecl *label) {
569       assert(PerformCleanup && "adding label to dead scope?");
570       Labels.push_back(label);
571     }
572 
573     /// \brief Exit this cleanup scope, emitting any accumulated
574     /// cleanups.
575     ~LexicalScope() {
576       if (CGDebugInfo *DI = CGF.getDebugInfo())
577         DI->EmitLexicalBlockEnd(CGF.Builder, Range.getEnd());
578 
579       // If we should perform a cleanup, force them now.  Note that
580       // this ends the cleanup scope before rescoping any labels.
581       if (PerformCleanup) {
582         ApplyDebugLocation DL(CGF, Range.getEnd());
583         ForceCleanup();
584       }
585     }
586 
587     /// \brief Force the emission of cleanups now, instead of waiting
588     /// until this object is destroyed.
589     void ForceCleanup() {
590       CGF.CurLexicalScope = ParentScope;
591       RunCleanupsScope::ForceCleanup();
592 
593       if (!Labels.empty())
594         rescopeLabels();
595     }
596 
597     void rescopeLabels();
598   };
599 
600   typedef llvm::DenseMap<const Decl *, Address> DeclMapTy;
601 
602   /// \brief The scope used to remap some variables as private in the OpenMP
603   /// loop body (or other captured region emitted without outlining), and to
604   /// restore old vars back on exit.
605   class OMPPrivateScope : public RunCleanupsScope {
606     DeclMapTy SavedLocals;
607     DeclMapTy SavedPrivates;
608 
609   private:
610     OMPPrivateScope(const OMPPrivateScope &) = delete;
611     void operator=(const OMPPrivateScope &) = delete;
612 
613   public:
614     /// \brief Enter a new OpenMP private scope.
615     explicit OMPPrivateScope(CodeGenFunction &CGF) : RunCleanupsScope(CGF) {}
616 
617     /// \brief Registers \a LocalVD variable as a private and apply \a
618     /// PrivateGen function for it to generate corresponding private variable.
619     /// \a PrivateGen returns an address of the generated private variable.
620     /// \return true if the variable is registered as private, false if it has
621     /// been privatized already.
622     bool
623     addPrivate(const VarDecl *LocalVD,
624                llvm::function_ref<Address()> PrivateGen) {
625       assert(PerformCleanup && "adding private to dead scope");
626 
627       // Only save it once.
628       if (SavedLocals.count(LocalVD)) return false;
629 
630       // Copy the existing local entry to SavedLocals.
631       auto it = CGF.LocalDeclMap.find(LocalVD);
632       if (it != CGF.LocalDeclMap.end()) {
633         SavedLocals.insert({LocalVD, it->second});
634       } else {
635         SavedLocals.insert({LocalVD, Address::invalid()});
636       }
637 
638       // Generate the private entry.
639       Address Addr = PrivateGen();
640       QualType VarTy = LocalVD->getType();
641       if (VarTy->isReferenceType()) {
642         Address Temp = CGF.CreateMemTemp(VarTy);
643         CGF.Builder.CreateStore(Addr.getPointer(), Temp);
644         Addr = Temp;
645       }
646       SavedPrivates.insert({LocalVD, Addr});
647 
648       return true;
649     }
650 
651     /// \brief Privatizes local variables previously registered as private.
652     /// Registration is separate from the actual privatization to allow
653     /// initializers use values of the original variables, not the private one.
654     /// This is important, for example, if the private variable is a class
655     /// variable initialized by a constructor that references other private
656     /// variables. But at initialization original variables must be used, not
657     /// private copies.
658     /// \return true if at least one variable was privatized, false otherwise.
659     bool Privatize() {
660       copyInto(SavedPrivates, CGF.LocalDeclMap);
661       SavedPrivates.clear();
662       return !SavedLocals.empty();
663     }
664 
665     void ForceCleanup() {
666       RunCleanupsScope::ForceCleanup();
667       copyInto(SavedLocals, CGF.LocalDeclMap);
668       SavedLocals.clear();
669     }
670 
671     /// \brief Exit scope - all the mapped variables are restored.
672     ~OMPPrivateScope() {
673       if (PerformCleanup)
674         ForceCleanup();
675     }
676 
677     /// Checks if the global variable is captured in current function.
678     bool isGlobalVarCaptured(const VarDecl *VD) const {
679       return !VD->isLocalVarDeclOrParm() && CGF.LocalDeclMap.count(VD) > 0;
680     }
681 
682   private:
683     /// Copy all the entries in the source map over the corresponding
684     /// entries in the destination, which must exist.
685     static void copyInto(const DeclMapTy &src, DeclMapTy &dest) {
686       for (auto &pair : src) {
687         if (!pair.second.isValid()) {
688           dest.erase(pair.first);
689           continue;
690         }
691 
692         auto it = dest.find(pair.first);
693         if (it != dest.end()) {
694           it->second = pair.second;
695         } else {
696           dest.insert(pair);
697         }
698       }
699     }
700   };
701 
702   /// \brief Takes the old cleanup stack size and emits the cleanup blocks
703   /// that have been added.
704   void PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize);
705 
706   /// \brief Takes the old cleanup stack size and emits the cleanup blocks
707   /// that have been added, then adds all lifetime-extended cleanups from
708   /// the given position to the stack.
709   void PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize,
710                         size_t OldLifetimeExtendedStackSize);
711 
712   void ResolveBranchFixups(llvm::BasicBlock *Target);
713 
714   /// The given basic block lies in the current EH scope, but may be a
715   /// target of a potentially scope-crossing jump; get a stable handle
716   /// to which we can perform this jump later.
717   JumpDest getJumpDestInCurrentScope(llvm::BasicBlock *Target) {
718     return JumpDest(Target,
719                     EHStack.getInnermostNormalCleanup(),
720                     NextCleanupDestIndex++);
721   }
722 
723   /// The given basic block lies in the current EH scope, but may be a
724   /// target of a potentially scope-crossing jump; get a stable handle
725   /// to which we can perform this jump later.
726   JumpDest getJumpDestInCurrentScope(StringRef Name = StringRef()) {
727     return getJumpDestInCurrentScope(createBasicBlock(Name));
728   }
729 
730   /// EmitBranchThroughCleanup - Emit a branch from the current insert
731   /// block through the normal cleanup handling code (if any) and then
732   /// on to \arg Dest.
733   void EmitBranchThroughCleanup(JumpDest Dest);
734 
735   /// isObviouslyBranchWithoutCleanups - Return true if a branch to the
736   /// specified destination obviously has no cleanups to run.  'false' is always
737   /// a conservatively correct answer for this method.
738   bool isObviouslyBranchWithoutCleanups(JumpDest Dest) const;
739 
740   /// popCatchScope - Pops the catch scope at the top of the EHScope
741   /// stack, emitting any required code (other than the catch handlers
742   /// themselves).
743   void popCatchScope();
744 
745   llvm::BasicBlock *getEHResumeBlock(bool isCleanup);
746   llvm::BasicBlock *getEHDispatchBlock(EHScopeStack::stable_iterator scope);
747   llvm::BasicBlock *getMSVCDispatchBlock(EHScopeStack::stable_iterator scope);
748 
749   /// An object to manage conditionally-evaluated expressions.
750   class ConditionalEvaluation {
751     llvm::BasicBlock *StartBB;
752 
753   public:
754     ConditionalEvaluation(CodeGenFunction &CGF)
755       : StartBB(CGF.Builder.GetInsertBlock()) {}
756 
757     void begin(CodeGenFunction &CGF) {
758       assert(CGF.OutermostConditional != this);
759       if (!CGF.OutermostConditional)
760         CGF.OutermostConditional = this;
761     }
762 
763     void end(CodeGenFunction &CGF) {
764       assert(CGF.OutermostConditional != nullptr);
765       if (CGF.OutermostConditional == this)
766         CGF.OutermostConditional = nullptr;
767     }
768 
769     /// Returns a block which will be executed prior to each
770     /// evaluation of the conditional code.
771     llvm::BasicBlock *getStartingBlock() const {
772       return StartBB;
773     }
774   };
775 
776   /// isInConditionalBranch - Return true if we're currently emitting
777   /// one branch or the other of a conditional expression.
778   bool isInConditionalBranch() const { return OutermostConditional != nullptr; }
779 
780   void setBeforeOutermostConditional(llvm::Value *value, Address addr) {
781     assert(isInConditionalBranch());
782     llvm::BasicBlock *block = OutermostConditional->getStartingBlock();
783     auto store = new llvm::StoreInst(value, addr.getPointer(), &block->back());
784     store->setAlignment(addr.getAlignment().getQuantity());
785   }
786 
787   /// An RAII object to record that we're evaluating a statement
788   /// expression.
789   class StmtExprEvaluation {
790     CodeGenFunction &CGF;
791 
792     /// We have to save the outermost conditional: cleanups in a
793     /// statement expression aren't conditional just because the
794     /// StmtExpr is.
795     ConditionalEvaluation *SavedOutermostConditional;
796 
797   public:
798     StmtExprEvaluation(CodeGenFunction &CGF)
799       : CGF(CGF), SavedOutermostConditional(CGF.OutermostConditional) {
800       CGF.OutermostConditional = nullptr;
801     }
802 
803     ~StmtExprEvaluation() {
804       CGF.OutermostConditional = SavedOutermostConditional;
805       CGF.EnsureInsertPoint();
806     }
807   };
808 
809   /// An object which temporarily prevents a value from being
810   /// destroyed by aggressive peephole optimizations that assume that
811   /// all uses of a value have been realized in the IR.
812   class PeepholeProtection {
813     llvm::Instruction *Inst;
814     friend class CodeGenFunction;
815 
816   public:
817     PeepholeProtection() : Inst(nullptr) {}
818   };
819 
820   /// A non-RAII class containing all the information about a bound
821   /// opaque value.  OpaqueValueMapping, below, is a RAII wrapper for
822   /// this which makes individual mappings very simple; using this
823   /// class directly is useful when you have a variable number of
824   /// opaque values or don't want the RAII functionality for some
825   /// reason.
826   class OpaqueValueMappingData {
827     const OpaqueValueExpr *OpaqueValue;
828     bool BoundLValue;
829     CodeGenFunction::PeepholeProtection Protection;
830 
831     OpaqueValueMappingData(const OpaqueValueExpr *ov,
832                            bool boundLValue)
833       : OpaqueValue(ov), BoundLValue(boundLValue) {}
834   public:
835     OpaqueValueMappingData() : OpaqueValue(nullptr) {}
836 
837     static bool shouldBindAsLValue(const Expr *expr) {
838       // gl-values should be bound as l-values for obvious reasons.
839       // Records should be bound as l-values because IR generation
840       // always keeps them in memory.  Expressions of function type
841       // act exactly like l-values but are formally required to be
842       // r-values in C.
843       return expr->isGLValue() ||
844              expr->getType()->isFunctionType() ||
845              hasAggregateEvaluationKind(expr->getType());
846     }
847 
848     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
849                                        const OpaqueValueExpr *ov,
850                                        const Expr *e) {
851       if (shouldBindAsLValue(ov))
852         return bind(CGF, ov, CGF.EmitLValue(e));
853       return bind(CGF, ov, CGF.EmitAnyExpr(e));
854     }
855 
856     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
857                                        const OpaqueValueExpr *ov,
858                                        const LValue &lv) {
859       assert(shouldBindAsLValue(ov));
860       CGF.OpaqueLValues.insert(std::make_pair(ov, lv));
861       return OpaqueValueMappingData(ov, true);
862     }
863 
864     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
865                                        const OpaqueValueExpr *ov,
866                                        const RValue &rv) {
867       assert(!shouldBindAsLValue(ov));
868       CGF.OpaqueRValues.insert(std::make_pair(ov, rv));
869 
870       OpaqueValueMappingData data(ov, false);
871 
872       // Work around an extremely aggressive peephole optimization in
873       // EmitScalarConversion which assumes that all other uses of a
874       // value are extant.
875       data.Protection = CGF.protectFromPeepholes(rv);
876 
877       return data;
878     }
879 
880     bool isValid() const { return OpaqueValue != nullptr; }
881     void clear() { OpaqueValue = nullptr; }
882 
883     void unbind(CodeGenFunction &CGF) {
884       assert(OpaqueValue && "no data to unbind!");
885 
886       if (BoundLValue) {
887         CGF.OpaqueLValues.erase(OpaqueValue);
888       } else {
889         CGF.OpaqueRValues.erase(OpaqueValue);
890         CGF.unprotectFromPeepholes(Protection);
891       }
892     }
893   };
894 
895   /// An RAII object to set (and then clear) a mapping for an OpaqueValueExpr.
896   class OpaqueValueMapping {
897     CodeGenFunction &CGF;
898     OpaqueValueMappingData Data;
899 
900   public:
901     static bool shouldBindAsLValue(const Expr *expr) {
902       return OpaqueValueMappingData::shouldBindAsLValue(expr);
903     }
904 
905     /// Build the opaque value mapping for the given conditional
906     /// operator if it's the GNU ?: extension.  This is a common
907     /// enough pattern that the convenience operator is really
908     /// helpful.
909     ///
910     OpaqueValueMapping(CodeGenFunction &CGF,
911                        const AbstractConditionalOperator *op) : CGF(CGF) {
912       if (isa<ConditionalOperator>(op))
913         // Leave Data empty.
914         return;
915 
916       const BinaryConditionalOperator *e = cast<BinaryConditionalOperator>(op);
917       Data = OpaqueValueMappingData::bind(CGF, e->getOpaqueValue(),
918                                           e->getCommon());
919     }
920 
921     OpaqueValueMapping(CodeGenFunction &CGF,
922                        const OpaqueValueExpr *opaqueValue,
923                        LValue lvalue)
924       : CGF(CGF), Data(OpaqueValueMappingData::bind(CGF, opaqueValue, lvalue)) {
925     }
926 
927     OpaqueValueMapping(CodeGenFunction &CGF,
928                        const OpaqueValueExpr *opaqueValue,
929                        RValue rvalue)
930       : CGF(CGF), Data(OpaqueValueMappingData::bind(CGF, opaqueValue, rvalue)) {
931     }
932 
933     void pop() {
934       Data.unbind(CGF);
935       Data.clear();
936     }
937 
938     ~OpaqueValueMapping() {
939       if (Data.isValid()) Data.unbind(CGF);
940     }
941   };
942 
943 private:
944   CGDebugInfo *DebugInfo;
945   bool DisableDebugInfo;
946 
947   /// DidCallStackSave - Whether llvm.stacksave has been called. Used to avoid
948   /// calling llvm.stacksave for multiple VLAs in the same scope.
949   bool DidCallStackSave;
950 
951   /// IndirectBranch - The first time an indirect goto is seen we create a block
952   /// with an indirect branch.  Every time we see the address of a label taken,
953   /// we add the label to the indirect goto.  Every subsequent indirect goto is
954   /// codegen'd as a jump to the IndirectBranch's basic block.
955   llvm::IndirectBrInst *IndirectBranch;
956 
957   /// LocalDeclMap - This keeps track of the LLVM allocas or globals for local C
958   /// decls.
959   DeclMapTy LocalDeclMap;
960 
961   /// SizeArguments - If a ParmVarDecl had the pass_object_size attribute, this
962   /// will contain a mapping from said ParmVarDecl to its implicit "object_size"
963   /// parameter.
964   llvm::SmallDenseMap<const ParmVarDecl *, const ImplicitParamDecl *, 2>
965       SizeArguments;
966 
967   /// Track escaped local variables with auto storage. Used during SEH
968   /// outlining to produce a call to llvm.localescape.
969   llvm::DenseMap<llvm::AllocaInst *, int> EscapedLocals;
970 
971   /// LabelMap - This keeps track of the LLVM basic block for each C label.
972   llvm::DenseMap<const LabelDecl*, JumpDest> LabelMap;
973 
974   // BreakContinueStack - This keeps track of where break and continue
975   // statements should jump to.
976   struct BreakContinue {
977     BreakContinue(JumpDest Break, JumpDest Continue)
978       : BreakBlock(Break), ContinueBlock(Continue) {}
979 
980     JumpDest BreakBlock;
981     JumpDest ContinueBlock;
982   };
983   SmallVector<BreakContinue, 8> BreakContinueStack;
984 
985   /// Data for exit block for proper support of OpenMP cancellation constructs.
986   struct OMPCancel {
987     JumpDest ExitBlock;
988     llvm::function_ref<void(CodeGenFunction &CGF)> CodeGen;
989     OMPCancel() : CodeGen([](CodeGenFunction &CGF) {}) {}
990   };
991   SmallVector<OMPCancel, 8> OMPCancelStack;
992 
993   /// Controls insertion of cancellation exit blocks in worksharing constructs.
994   class OMPCancelStackRAII {
995     CodeGenFunction &CGF;
996 
997   public:
998     OMPCancelStackRAII(CodeGenFunction &CGF) : CGF(CGF) {
999       CGF.OMPCancelStack.push_back({});
1000     }
1001     ~OMPCancelStackRAII() {
1002       if (CGF.HaveInsertPoint() &&
1003           CGF.OMPCancelStack.back().ExitBlock.isValid()) {
1004         auto CJD = CGF.getJumpDestInCurrentScope("cancel.cont");
1005         CGF.EmitBranchThroughCleanup(CJD);
1006         CGF.EmitBlock(CGF.OMPCancelStack.back().ExitBlock.getBlock());
1007         CGF.OMPCancelStack.back().CodeGen(CGF);
1008         CGF.EmitBranchThroughCleanup(CJD);
1009         CGF.EmitBlock(CJD.getBlock());
1010       }
1011     }
1012   };
1013 
1014   CodeGenPGO PGO;
1015 
1016   /// Calculate branch weights appropriate for PGO data
1017   llvm::MDNode *createProfileWeights(uint64_t TrueCount, uint64_t FalseCount);
1018   llvm::MDNode *createProfileWeights(ArrayRef<uint64_t> Weights);
1019   llvm::MDNode *createProfileWeightsForLoop(const Stmt *Cond,
1020                                             uint64_t LoopCount);
1021 
1022 public:
1023   /// Increment the profiler's counter for the given statement.
1024   void incrementProfileCounter(const Stmt *S) {
1025     if (CGM.getCodeGenOpts().hasProfileClangInstr())
1026       PGO.emitCounterIncrement(Builder, S);
1027     PGO.setCurrentStmt(S);
1028   }
1029 
1030   /// Get the profiler's count for the given statement.
1031   uint64_t getProfileCount(const Stmt *S) {
1032     Optional<uint64_t> Count = PGO.getStmtCount(S);
1033     if (!Count.hasValue())
1034       return 0;
1035     return *Count;
1036   }
1037 
1038   /// Set the profiler's current count.
1039   void setCurrentProfileCount(uint64_t Count) {
1040     PGO.setCurrentRegionCount(Count);
1041   }
1042 
1043   /// Get the profiler's current count. This is generally the count for the most
1044   /// recently incremented counter.
1045   uint64_t getCurrentProfileCount() {
1046     return PGO.getCurrentRegionCount();
1047   }
1048 
1049 private:
1050 
1051   /// SwitchInsn - This is nearest current switch instruction. It is null if
1052   /// current context is not in a switch.
1053   llvm::SwitchInst *SwitchInsn;
1054   /// The branch weights of SwitchInsn when doing instrumentation based PGO.
1055   SmallVector<uint64_t, 16> *SwitchWeights;
1056 
1057   /// CaseRangeBlock - This block holds if condition check for last case
1058   /// statement range in current switch instruction.
1059   llvm::BasicBlock *CaseRangeBlock;
1060 
1061   /// OpaqueLValues - Keeps track of the current set of opaque value
1062   /// expressions.
1063   llvm::DenseMap<const OpaqueValueExpr *, LValue> OpaqueLValues;
1064   llvm::DenseMap<const OpaqueValueExpr *, RValue> OpaqueRValues;
1065 
1066   // VLASizeMap - This keeps track of the associated size for each VLA type.
1067   // We track this by the size expression rather than the type itself because
1068   // in certain situations, like a const qualifier applied to an VLA typedef,
1069   // multiple VLA types can share the same size expression.
1070   // FIXME: Maybe this could be a stack of maps that is pushed/popped as we
1071   // enter/leave scopes.
1072   llvm::DenseMap<const Expr*, llvm::Value*> VLASizeMap;
1073 
1074   /// A block containing a single 'unreachable' instruction.  Created
1075   /// lazily by getUnreachableBlock().
1076   llvm::BasicBlock *UnreachableBlock;
1077 
1078   /// Counts of the number return expressions in the function.
1079   unsigned NumReturnExprs;
1080 
1081   /// Count the number of simple (constant) return expressions in the function.
1082   unsigned NumSimpleReturnExprs;
1083 
1084   /// The last regular (non-return) debug location (breakpoint) in the function.
1085   SourceLocation LastStopPoint;
1086 
1087 public:
1088   /// A scope within which we are constructing the fields of an object which
1089   /// might use a CXXDefaultInitExpr. This stashes away a 'this' value to use
1090   /// if we need to evaluate a CXXDefaultInitExpr within the evaluation.
1091   class FieldConstructionScope {
1092   public:
1093     FieldConstructionScope(CodeGenFunction &CGF, Address This)
1094         : CGF(CGF), OldCXXDefaultInitExprThis(CGF.CXXDefaultInitExprThis) {
1095       CGF.CXXDefaultInitExprThis = This;
1096     }
1097     ~FieldConstructionScope() {
1098       CGF.CXXDefaultInitExprThis = OldCXXDefaultInitExprThis;
1099     }
1100 
1101   private:
1102     CodeGenFunction &CGF;
1103     Address OldCXXDefaultInitExprThis;
1104   };
1105 
1106   /// The scope of a CXXDefaultInitExpr. Within this scope, the value of 'this'
1107   /// is overridden to be the object under construction.
1108   class CXXDefaultInitExprScope {
1109   public:
1110     CXXDefaultInitExprScope(CodeGenFunction &CGF)
1111       : CGF(CGF), OldCXXThisValue(CGF.CXXThisValue),
1112         OldCXXThisAlignment(CGF.CXXThisAlignment) {
1113       CGF.CXXThisValue = CGF.CXXDefaultInitExprThis.getPointer();
1114       CGF.CXXThisAlignment = CGF.CXXDefaultInitExprThis.getAlignment();
1115     }
1116     ~CXXDefaultInitExprScope() {
1117       CGF.CXXThisValue = OldCXXThisValue;
1118       CGF.CXXThisAlignment = OldCXXThisAlignment;
1119     }
1120 
1121   public:
1122     CodeGenFunction &CGF;
1123     llvm::Value *OldCXXThisValue;
1124     CharUnits OldCXXThisAlignment;
1125   };
1126 
1127   class InlinedInheritingConstructorScope {
1128   public:
1129     InlinedInheritingConstructorScope(CodeGenFunction &CGF, GlobalDecl GD)
1130         : CGF(CGF), OldCurGD(CGF.CurGD), OldCurFuncDecl(CGF.CurFuncDecl),
1131           OldCurCodeDecl(CGF.CurCodeDecl),
1132           OldCXXABIThisDecl(CGF.CXXABIThisDecl),
1133           OldCXXABIThisValue(CGF.CXXABIThisValue),
1134           OldCXXThisValue(CGF.CXXThisValue),
1135           OldCXXABIThisAlignment(CGF.CXXABIThisAlignment),
1136           OldCXXThisAlignment(CGF.CXXThisAlignment),
1137           OldReturnValue(CGF.ReturnValue), OldFnRetTy(CGF.FnRetTy),
1138           OldCXXInheritedCtorInitExprArgs(
1139               std::move(CGF.CXXInheritedCtorInitExprArgs)) {
1140       CGF.CurGD = GD;
1141       CGF.CurFuncDecl = CGF.CurCodeDecl =
1142           cast<CXXConstructorDecl>(GD.getDecl());
1143       CGF.CXXABIThisDecl = nullptr;
1144       CGF.CXXABIThisValue = nullptr;
1145       CGF.CXXThisValue = nullptr;
1146       CGF.CXXABIThisAlignment = CharUnits();
1147       CGF.CXXThisAlignment = CharUnits();
1148       CGF.ReturnValue = Address::invalid();
1149       CGF.FnRetTy = QualType();
1150       CGF.CXXInheritedCtorInitExprArgs.clear();
1151     }
1152     ~InlinedInheritingConstructorScope() {
1153       CGF.CurGD = OldCurGD;
1154       CGF.CurFuncDecl = OldCurFuncDecl;
1155       CGF.CurCodeDecl = OldCurCodeDecl;
1156       CGF.CXXABIThisDecl = OldCXXABIThisDecl;
1157       CGF.CXXABIThisValue = OldCXXABIThisValue;
1158       CGF.CXXThisValue = OldCXXThisValue;
1159       CGF.CXXABIThisAlignment = OldCXXABIThisAlignment;
1160       CGF.CXXThisAlignment = OldCXXThisAlignment;
1161       CGF.ReturnValue = OldReturnValue;
1162       CGF.FnRetTy = OldFnRetTy;
1163       CGF.CXXInheritedCtorInitExprArgs =
1164           std::move(OldCXXInheritedCtorInitExprArgs);
1165     }
1166 
1167   private:
1168     CodeGenFunction &CGF;
1169     GlobalDecl OldCurGD;
1170     const Decl *OldCurFuncDecl;
1171     const Decl *OldCurCodeDecl;
1172     ImplicitParamDecl *OldCXXABIThisDecl;
1173     llvm::Value *OldCXXABIThisValue;
1174     llvm::Value *OldCXXThisValue;
1175     CharUnits OldCXXABIThisAlignment;
1176     CharUnits OldCXXThisAlignment;
1177     Address OldReturnValue;
1178     QualType OldFnRetTy;
1179     CallArgList OldCXXInheritedCtorInitExprArgs;
1180   };
1181 
1182 private:
1183   /// CXXThisDecl - When generating code for a C++ member function,
1184   /// this will hold the implicit 'this' declaration.
1185   ImplicitParamDecl *CXXABIThisDecl;
1186   llvm::Value *CXXABIThisValue;
1187   llvm::Value *CXXThisValue;
1188   CharUnits CXXABIThisAlignment;
1189   CharUnits CXXThisAlignment;
1190 
1191   /// The value of 'this' to use when evaluating CXXDefaultInitExprs within
1192   /// this expression.
1193   Address CXXDefaultInitExprThis = Address::invalid();
1194 
1195   /// The values of function arguments to use when evaluating
1196   /// CXXInheritedCtorInitExprs within this context.
1197   CallArgList CXXInheritedCtorInitExprArgs;
1198 
1199   /// CXXStructorImplicitParamDecl - When generating code for a constructor or
1200   /// destructor, this will hold the implicit argument (e.g. VTT).
1201   ImplicitParamDecl *CXXStructorImplicitParamDecl;
1202   llvm::Value *CXXStructorImplicitParamValue;
1203 
1204   /// OutermostConditional - Points to the outermost active
1205   /// conditional control.  This is used so that we know if a
1206   /// temporary should be destroyed conditionally.
1207   ConditionalEvaluation *OutermostConditional;
1208 
1209   /// The current lexical scope.
1210   LexicalScope *CurLexicalScope;
1211 
1212   /// The current source location that should be used for exception
1213   /// handling code.
1214   SourceLocation CurEHLocation;
1215 
1216   /// BlockByrefInfos - For each __block variable, contains
1217   /// information about the layout of the variable.
1218   llvm::DenseMap<const ValueDecl *, BlockByrefInfo> BlockByrefInfos;
1219 
1220   llvm::BasicBlock *TerminateLandingPad;
1221   llvm::BasicBlock *TerminateHandler;
1222   llvm::BasicBlock *TrapBB;
1223 
1224   /// True if we need emit the life-time markers.
1225   const bool ShouldEmitLifetimeMarkers;
1226 
1227   /// Add a kernel metadata node to the named metadata node 'opencl.kernels'.
1228   /// In the kernel metadata node, reference the kernel function and metadata
1229   /// nodes for its optional attribute qualifiers (OpenCL 1.1 6.7.2):
1230   /// - A node for the vec_type_hint(<type>) qualifier contains string
1231   ///   "vec_type_hint", an undefined value of the <type> data type,
1232   ///   and a Boolean that is true if the <type> is integer and signed.
1233   /// - A node for the work_group_size_hint(X,Y,Z) qualifier contains string
1234   ///   "work_group_size_hint", and three 32-bit integers X, Y and Z.
1235   /// - A node for the reqd_work_group_size(X,Y,Z) qualifier contains string
1236   ///   "reqd_work_group_size", and three 32-bit integers X, Y and Z.
1237   void EmitOpenCLKernelMetadata(const FunctionDecl *FD,
1238                                 llvm::Function *Fn);
1239 
1240 public:
1241   CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext=false);
1242   ~CodeGenFunction();
1243 
1244   CodeGenTypes &getTypes() const { return CGM.getTypes(); }
1245   ASTContext &getContext() const { return CGM.getContext(); }
1246   CGDebugInfo *getDebugInfo() {
1247     if (DisableDebugInfo)
1248       return nullptr;
1249     return DebugInfo;
1250   }
1251   void disableDebugInfo() { DisableDebugInfo = true; }
1252   void enableDebugInfo() { DisableDebugInfo = false; }
1253 
1254   bool shouldUseFusedARCCalls() {
1255     return CGM.getCodeGenOpts().OptimizationLevel == 0;
1256   }
1257 
1258   const LangOptions &getLangOpts() const { return CGM.getLangOpts(); }
1259 
1260   /// Returns a pointer to the function's exception object and selector slot,
1261   /// which is assigned in every landing pad.
1262   Address getExceptionSlot();
1263   Address getEHSelectorSlot();
1264 
1265   /// Returns the contents of the function's exception object and selector
1266   /// slots.
1267   llvm::Value *getExceptionFromSlot();
1268   llvm::Value *getSelectorFromSlot();
1269 
1270   Address getNormalCleanupDestSlot();
1271 
1272   llvm::BasicBlock *getUnreachableBlock() {
1273     if (!UnreachableBlock) {
1274       UnreachableBlock = createBasicBlock("unreachable");
1275       new llvm::UnreachableInst(getLLVMContext(), UnreachableBlock);
1276     }
1277     return UnreachableBlock;
1278   }
1279 
1280   llvm::BasicBlock *getInvokeDest() {
1281     if (!EHStack.requiresLandingPad()) return nullptr;
1282     return getInvokeDestImpl();
1283   }
1284 
1285   bool currentFunctionUsesSEHTry() const { return CurSEHParent != nullptr; }
1286 
1287   const TargetInfo &getTarget() const { return Target; }
1288   llvm::LLVMContext &getLLVMContext() { return CGM.getLLVMContext(); }
1289 
1290   //===--------------------------------------------------------------------===//
1291   //                                  Cleanups
1292   //===--------------------------------------------------------------------===//
1293 
1294   typedef void Destroyer(CodeGenFunction &CGF, Address addr, QualType ty);
1295 
1296   void pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin,
1297                                         Address arrayEndPointer,
1298                                         QualType elementType,
1299                                         CharUnits elementAlignment,
1300                                         Destroyer *destroyer);
1301   void pushRegularPartialArrayCleanup(llvm::Value *arrayBegin,
1302                                       llvm::Value *arrayEnd,
1303                                       QualType elementType,
1304                                       CharUnits elementAlignment,
1305                                       Destroyer *destroyer);
1306 
1307   void pushDestroy(QualType::DestructionKind dtorKind,
1308                    Address addr, QualType type);
1309   void pushEHDestroy(QualType::DestructionKind dtorKind,
1310                      Address addr, QualType type);
1311   void pushDestroy(CleanupKind kind, Address addr, QualType type,
1312                    Destroyer *destroyer, bool useEHCleanupForArray);
1313   void pushLifetimeExtendedDestroy(CleanupKind kind, Address addr,
1314                                    QualType type, Destroyer *destroyer,
1315                                    bool useEHCleanupForArray);
1316   void pushCallObjectDeleteCleanup(const FunctionDecl *OperatorDelete,
1317                                    llvm::Value *CompletePtr,
1318                                    QualType ElementType);
1319   void pushStackRestore(CleanupKind kind, Address SPMem);
1320   void emitDestroy(Address addr, QualType type, Destroyer *destroyer,
1321                    bool useEHCleanupForArray);
1322   llvm::Function *generateDestroyHelper(Address addr, QualType type,
1323                                         Destroyer *destroyer,
1324                                         bool useEHCleanupForArray,
1325                                         const VarDecl *VD);
1326   void emitArrayDestroy(llvm::Value *begin, llvm::Value *end,
1327                         QualType elementType, CharUnits elementAlign,
1328                         Destroyer *destroyer,
1329                         bool checkZeroLength, bool useEHCleanup);
1330 
1331   Destroyer *getDestroyer(QualType::DestructionKind destructionKind);
1332 
1333   /// Determines whether an EH cleanup is required to destroy a type
1334   /// with the given destruction kind.
1335   bool needsEHCleanup(QualType::DestructionKind kind) {
1336     switch (kind) {
1337     case QualType::DK_none:
1338       return false;
1339     case QualType::DK_cxx_destructor:
1340     case QualType::DK_objc_weak_lifetime:
1341       return getLangOpts().Exceptions;
1342     case QualType::DK_objc_strong_lifetime:
1343       return getLangOpts().Exceptions &&
1344              CGM.getCodeGenOpts().ObjCAutoRefCountExceptions;
1345     }
1346     llvm_unreachable("bad destruction kind");
1347   }
1348 
1349   CleanupKind getCleanupKind(QualType::DestructionKind kind) {
1350     return (needsEHCleanup(kind) ? NormalAndEHCleanup : NormalCleanup);
1351   }
1352 
1353   //===--------------------------------------------------------------------===//
1354   //                                  Objective-C
1355   //===--------------------------------------------------------------------===//
1356 
1357   void GenerateObjCMethod(const ObjCMethodDecl *OMD);
1358 
1359   void StartObjCMethod(const ObjCMethodDecl *MD, const ObjCContainerDecl *CD);
1360 
1361   /// GenerateObjCGetter - Synthesize an Objective-C property getter function.
1362   void GenerateObjCGetter(ObjCImplementationDecl *IMP,
1363                           const ObjCPropertyImplDecl *PID);
1364   void generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
1365                               const ObjCPropertyImplDecl *propImpl,
1366                               const ObjCMethodDecl *GetterMothodDecl,
1367                               llvm::Constant *AtomicHelperFn);
1368 
1369   void GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP,
1370                                   ObjCMethodDecl *MD, bool ctor);
1371 
1372   /// GenerateObjCSetter - Synthesize an Objective-C property setter function
1373   /// for the given property.
1374   void GenerateObjCSetter(ObjCImplementationDecl *IMP,
1375                           const ObjCPropertyImplDecl *PID);
1376   void generateObjCSetterBody(const ObjCImplementationDecl *classImpl,
1377                               const ObjCPropertyImplDecl *propImpl,
1378                               llvm::Constant *AtomicHelperFn);
1379 
1380   //===--------------------------------------------------------------------===//
1381   //                                  Block Bits
1382   //===--------------------------------------------------------------------===//
1383 
1384   llvm::Value *EmitBlockLiteral(const BlockExpr *);
1385   llvm::Value *EmitBlockLiteral(const CGBlockInfo &Info);
1386   static void destroyBlockInfos(CGBlockInfo *info);
1387 
1388   llvm::Function *GenerateBlockFunction(GlobalDecl GD,
1389                                         const CGBlockInfo &Info,
1390                                         const DeclMapTy &ldm,
1391                                         bool IsLambdaConversionToBlock);
1392 
1393   llvm::Constant *GenerateCopyHelperFunction(const CGBlockInfo &blockInfo);
1394   llvm::Constant *GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo);
1395   llvm::Constant *GenerateObjCAtomicSetterCopyHelperFunction(
1396                                              const ObjCPropertyImplDecl *PID);
1397   llvm::Constant *GenerateObjCAtomicGetterCopyHelperFunction(
1398                                              const ObjCPropertyImplDecl *PID);
1399   llvm::Value *EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty);
1400 
1401   void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags);
1402 
1403   class AutoVarEmission;
1404 
1405   void emitByrefStructureInit(const AutoVarEmission &emission);
1406   void enterByrefCleanup(const AutoVarEmission &emission);
1407 
1408   void setBlockContextParameter(const ImplicitParamDecl *D, unsigned argNum,
1409                                 llvm::Value *ptr);
1410 
1411   Address LoadBlockStruct();
1412   Address GetAddrOfBlockDecl(const VarDecl *var, bool ByRef);
1413 
1414   /// BuildBlockByrefAddress - Computes the location of the
1415   /// data in a variable which is declared as __block.
1416   Address emitBlockByrefAddress(Address baseAddr, const VarDecl *V,
1417                                 bool followForward = true);
1418   Address emitBlockByrefAddress(Address baseAddr,
1419                                 const BlockByrefInfo &info,
1420                                 bool followForward,
1421                                 const llvm::Twine &name);
1422 
1423   const BlockByrefInfo &getBlockByrefInfo(const VarDecl *var);
1424 
1425   QualType BuildFunctionArgList(GlobalDecl GD, FunctionArgList &Args);
1426 
1427   void GenerateCode(GlobalDecl GD, llvm::Function *Fn,
1428                     const CGFunctionInfo &FnInfo);
1429   /// \brief Emit code for the start of a function.
1430   /// \param Loc       The location to be associated with the function.
1431   /// \param StartLoc  The location of the function body.
1432   void StartFunction(GlobalDecl GD,
1433                      QualType RetTy,
1434                      llvm::Function *Fn,
1435                      const CGFunctionInfo &FnInfo,
1436                      const FunctionArgList &Args,
1437                      SourceLocation Loc = SourceLocation(),
1438                      SourceLocation StartLoc = SourceLocation());
1439 
1440   void EmitConstructorBody(FunctionArgList &Args);
1441   void EmitDestructorBody(FunctionArgList &Args);
1442   void emitImplicitAssignmentOperatorBody(FunctionArgList &Args);
1443   void EmitFunctionBody(FunctionArgList &Args, const Stmt *Body);
1444   void EmitBlockWithFallThrough(llvm::BasicBlock *BB, const Stmt *S);
1445 
1446   void EmitForwardingCallToLambda(const CXXMethodDecl *LambdaCallOperator,
1447                                   CallArgList &CallArgs);
1448   void EmitLambdaToBlockPointerBody(FunctionArgList &Args);
1449   void EmitLambdaBlockInvokeBody();
1450   void EmitLambdaDelegatingInvokeBody(const CXXMethodDecl *MD);
1451   void EmitLambdaStaticInvokeFunction(const CXXMethodDecl *MD);
1452   void EmitAsanPrologueOrEpilogue(bool Prologue);
1453 
1454   /// \brief Emit the unified return block, trying to avoid its emission when
1455   /// possible.
1456   /// \return The debug location of the user written return statement if the
1457   /// return block is is avoided.
1458   llvm::DebugLoc EmitReturnBlock();
1459 
1460   /// FinishFunction - Complete IR generation of the current function. It is
1461   /// legal to call this function even if there is no current insertion point.
1462   void FinishFunction(SourceLocation EndLoc=SourceLocation());
1463 
1464   void StartThunk(llvm::Function *Fn, GlobalDecl GD,
1465                   const CGFunctionInfo &FnInfo);
1466 
1467   void EmitCallAndReturnForThunk(llvm::Constant *Callee,
1468                                  const ThunkInfo *Thunk);
1469 
1470   void FinishThunk();
1471 
1472   /// Emit a musttail call for a thunk with a potentially adjusted this pointer.
1473   void EmitMustTailThunk(const CXXMethodDecl *MD, llvm::Value *AdjustedThisPtr,
1474                          llvm::Value *Callee);
1475 
1476   /// Generate a thunk for the given method.
1477   void generateThunk(llvm::Function *Fn, const CGFunctionInfo &FnInfo,
1478                      GlobalDecl GD, const ThunkInfo &Thunk);
1479 
1480   llvm::Function *GenerateVarArgsThunk(llvm::Function *Fn,
1481                                        const CGFunctionInfo &FnInfo,
1482                                        GlobalDecl GD, const ThunkInfo &Thunk);
1483 
1484   void EmitCtorPrologue(const CXXConstructorDecl *CD, CXXCtorType Type,
1485                         FunctionArgList &Args);
1486 
1487   void EmitInitializerForField(FieldDecl *Field, LValue LHS, Expr *Init,
1488                                ArrayRef<VarDecl *> ArrayIndexes);
1489 
1490   /// Struct with all informations about dynamic [sub]class needed to set vptr.
1491   struct VPtr {
1492     BaseSubobject Base;
1493     const CXXRecordDecl *NearestVBase;
1494     CharUnits OffsetFromNearestVBase;
1495     const CXXRecordDecl *VTableClass;
1496   };
1497 
1498   /// Initialize the vtable pointer of the given subobject.
1499   void InitializeVTablePointer(const VPtr &vptr);
1500 
1501   typedef llvm::SmallVector<VPtr, 4> VPtrsVector;
1502 
1503   typedef llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBasesSetTy;
1504   VPtrsVector getVTablePointers(const CXXRecordDecl *VTableClass);
1505 
1506   void getVTablePointers(BaseSubobject Base, const CXXRecordDecl *NearestVBase,
1507                          CharUnits OffsetFromNearestVBase,
1508                          bool BaseIsNonVirtualPrimaryBase,
1509                          const CXXRecordDecl *VTableClass,
1510                          VisitedVirtualBasesSetTy &VBases, VPtrsVector &vptrs);
1511 
1512   void InitializeVTablePointers(const CXXRecordDecl *ClassDecl);
1513 
1514   /// GetVTablePtr - Return the Value of the vtable pointer member pointed
1515   /// to by This.
1516   llvm::Value *GetVTablePtr(Address This, llvm::Type *VTableTy,
1517                             const CXXRecordDecl *VTableClass);
1518 
1519   enum CFITypeCheckKind {
1520     CFITCK_VCall,
1521     CFITCK_NVCall,
1522     CFITCK_DerivedCast,
1523     CFITCK_UnrelatedCast,
1524     CFITCK_ICall,
1525   };
1526 
1527   /// \brief Derived is the presumed address of an object of type T after a
1528   /// cast. If T is a polymorphic class type, emit a check that the virtual
1529   /// table for Derived belongs to a class derived from T.
1530   void EmitVTablePtrCheckForCast(QualType T, llvm::Value *Derived,
1531                                  bool MayBeNull, CFITypeCheckKind TCK,
1532                                  SourceLocation Loc);
1533 
1534   /// EmitVTablePtrCheckForCall - Virtual method MD is being called via VTable.
1535   /// If vptr CFI is enabled, emit a check that VTable is valid.
1536   void EmitVTablePtrCheckForCall(const CXXRecordDecl *RD, llvm::Value *VTable,
1537                                  CFITypeCheckKind TCK, SourceLocation Loc);
1538 
1539   /// EmitVTablePtrCheck - Emit a check that VTable is a valid virtual table for
1540   /// RD using llvm.type.test.
1541   void EmitVTablePtrCheck(const CXXRecordDecl *RD, llvm::Value *VTable,
1542                           CFITypeCheckKind TCK, SourceLocation Loc);
1543 
1544   /// If whole-program virtual table optimization is enabled, emit an assumption
1545   /// that VTable is a member of RD's type identifier. Or, if vptr CFI is
1546   /// enabled, emit a check that VTable is a member of RD's type identifier.
1547   void EmitTypeMetadataCodeForVCall(const CXXRecordDecl *RD,
1548                                     llvm::Value *VTable, SourceLocation Loc);
1549 
1550   /// Returns whether we should perform a type checked load when loading a
1551   /// virtual function for virtual calls to members of RD. This is generally
1552   /// true when both vcall CFI and whole-program-vtables are enabled.
1553   bool ShouldEmitVTableTypeCheckedLoad(const CXXRecordDecl *RD);
1554 
1555   /// Emit a type checked load from the given vtable.
1556   llvm::Value *EmitVTableTypeCheckedLoad(const CXXRecordDecl *RD, llvm::Value *VTable,
1557                                          uint64_t VTableByteOffset);
1558 
1559   /// CanDevirtualizeMemberFunctionCalls - Checks whether virtual calls on given
1560   /// expr can be devirtualized.
1561   bool CanDevirtualizeMemberFunctionCall(const Expr *Base,
1562                                          const CXXMethodDecl *MD);
1563 
1564   /// EnterDtorCleanups - Enter the cleanups necessary to complete the
1565   /// given phase of destruction for a destructor.  The end result
1566   /// should call destructors on members and base classes in reverse
1567   /// order of their construction.
1568   void EnterDtorCleanups(const CXXDestructorDecl *Dtor, CXXDtorType Type);
1569 
1570   /// ShouldInstrumentFunction - Return true if the current function should be
1571   /// instrumented with __cyg_profile_func_* calls
1572   bool ShouldInstrumentFunction();
1573 
1574   /// ShouldXRayInstrument - Return true if the current function should be
1575   /// instrumented with XRay nop sleds.
1576   bool ShouldXRayInstrumentFunction() const;
1577 
1578   /// EmitFunctionInstrumentation - Emit LLVM code to call the specified
1579   /// instrumentation function with the current function and the call site, if
1580   /// function instrumentation is enabled.
1581   void EmitFunctionInstrumentation(const char *Fn);
1582 
1583   /// EmitMCountInstrumentation - Emit call to .mcount.
1584   void EmitMCountInstrumentation();
1585 
1586   /// EmitFunctionProlog - Emit the target specific LLVM code to load the
1587   /// arguments for the given function. This is also responsible for naming the
1588   /// LLVM function arguments.
1589   void EmitFunctionProlog(const CGFunctionInfo &FI,
1590                           llvm::Function *Fn,
1591                           const FunctionArgList &Args);
1592 
1593   /// EmitFunctionEpilog - Emit the target specific LLVM code to return the
1594   /// given temporary.
1595   void EmitFunctionEpilog(const CGFunctionInfo &FI, bool EmitRetDbgLoc,
1596                           SourceLocation EndLoc);
1597 
1598   /// EmitStartEHSpec - Emit the start of the exception spec.
1599   void EmitStartEHSpec(const Decl *D);
1600 
1601   /// EmitEndEHSpec - Emit the end of the exception spec.
1602   void EmitEndEHSpec(const Decl *D);
1603 
1604   /// getTerminateLandingPad - Return a landing pad that just calls terminate.
1605   llvm::BasicBlock *getTerminateLandingPad();
1606 
1607   /// getTerminateHandler - Return a handler (not a landing pad, just
1608   /// a catch handler) that just calls terminate.  This is used when
1609   /// a terminate scope encloses a try.
1610   llvm::BasicBlock *getTerminateHandler();
1611 
1612   llvm::Type *ConvertTypeForMem(QualType T);
1613   llvm::Type *ConvertType(QualType T);
1614   llvm::Type *ConvertType(const TypeDecl *T) {
1615     return ConvertType(getContext().getTypeDeclType(T));
1616   }
1617 
1618   /// LoadObjCSelf - Load the value of self. This function is only valid while
1619   /// generating code for an Objective-C method.
1620   llvm::Value *LoadObjCSelf();
1621 
1622   /// TypeOfSelfObject - Return type of object that this self represents.
1623   QualType TypeOfSelfObject();
1624 
1625   /// hasAggregateLLVMType - Return true if the specified AST type will map into
1626   /// an aggregate LLVM type or is void.
1627   static TypeEvaluationKind getEvaluationKind(QualType T);
1628 
1629   static bool hasScalarEvaluationKind(QualType T) {
1630     return getEvaluationKind(T) == TEK_Scalar;
1631   }
1632 
1633   static bool hasAggregateEvaluationKind(QualType T) {
1634     return getEvaluationKind(T) == TEK_Aggregate;
1635   }
1636 
1637   /// createBasicBlock - Create an LLVM basic block.
1638   llvm::BasicBlock *createBasicBlock(const Twine &name = "",
1639                                      llvm::Function *parent = nullptr,
1640                                      llvm::BasicBlock *before = nullptr) {
1641 #ifdef NDEBUG
1642     return llvm::BasicBlock::Create(getLLVMContext(), "", parent, before);
1643 #else
1644     return llvm::BasicBlock::Create(getLLVMContext(), name, parent, before);
1645 #endif
1646   }
1647 
1648   /// getBasicBlockForLabel - Return the LLVM basicblock that the specified
1649   /// label maps to.
1650   JumpDest getJumpDestForLabel(const LabelDecl *S);
1651 
1652   /// SimplifyForwardingBlocks - If the given basic block is only a branch to
1653   /// another basic block, simplify it. This assumes that no other code could
1654   /// potentially reference the basic block.
1655   void SimplifyForwardingBlocks(llvm::BasicBlock *BB);
1656 
1657   /// EmitBlock - Emit the given block \arg BB and set it as the insert point,
1658   /// adding a fall-through branch from the current insert block if
1659   /// necessary. It is legal to call this function even if there is no current
1660   /// insertion point.
1661   ///
1662   /// IsFinished - If true, indicates that the caller has finished emitting
1663   /// branches to the given block and does not expect to emit code into it. This
1664   /// means the block can be ignored if it is unreachable.
1665   void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false);
1666 
1667   /// EmitBlockAfterUses - Emit the given block somewhere hopefully
1668   /// near its uses, and leave the insertion point in it.
1669   void EmitBlockAfterUses(llvm::BasicBlock *BB);
1670 
1671   /// EmitBranch - Emit a branch to the specified basic block from the current
1672   /// insert block, taking care to avoid creation of branches from dummy
1673   /// blocks. It is legal to call this function even if there is no current
1674   /// insertion point.
1675   ///
1676   /// This function clears the current insertion point. The caller should follow
1677   /// calls to this function with calls to Emit*Block prior to generation new
1678   /// code.
1679   void EmitBranch(llvm::BasicBlock *Block);
1680 
1681   /// HaveInsertPoint - True if an insertion point is defined. If not, this
1682   /// indicates that the current code being emitted is unreachable.
1683   bool HaveInsertPoint() const {
1684     return Builder.GetInsertBlock() != nullptr;
1685   }
1686 
1687   /// EnsureInsertPoint - Ensure that an insertion point is defined so that
1688   /// emitted IR has a place to go. Note that by definition, if this function
1689   /// creates a block then that block is unreachable; callers may do better to
1690   /// detect when no insertion point is defined and simply skip IR generation.
1691   void EnsureInsertPoint() {
1692     if (!HaveInsertPoint())
1693       EmitBlock(createBasicBlock());
1694   }
1695 
1696   /// ErrorUnsupported - Print out an error that codegen doesn't support the
1697   /// specified stmt yet.
1698   void ErrorUnsupported(const Stmt *S, const char *Type);
1699 
1700   //===--------------------------------------------------------------------===//
1701   //                                  Helpers
1702   //===--------------------------------------------------------------------===//
1703 
1704   LValue MakeAddrLValue(Address Addr, QualType T,
1705                         AlignmentSource AlignSource = AlignmentSource::Type) {
1706     return LValue::MakeAddr(Addr, T, getContext(), AlignSource,
1707                             CGM.getTBAAInfo(T));
1708   }
1709 
1710   LValue MakeAddrLValue(llvm::Value *V, QualType T, CharUnits Alignment,
1711                         AlignmentSource AlignSource = AlignmentSource::Type) {
1712     return LValue::MakeAddr(Address(V, Alignment), T, getContext(),
1713                             AlignSource, CGM.getTBAAInfo(T));
1714   }
1715 
1716   LValue MakeNaturalAlignPointeeAddrLValue(llvm::Value *V, QualType T);
1717   LValue MakeNaturalAlignAddrLValue(llvm::Value *V, QualType T);
1718   CharUnits getNaturalTypeAlignment(QualType T,
1719                                     AlignmentSource *Source = nullptr,
1720                                     bool forPointeeType = false);
1721   CharUnits getNaturalPointeeTypeAlignment(QualType T,
1722                                            AlignmentSource *Source = nullptr);
1723 
1724   Address EmitLoadOfReference(Address Ref, const ReferenceType *RefTy,
1725                               AlignmentSource *Source = nullptr);
1726   LValue EmitLoadOfReferenceLValue(Address Ref, const ReferenceType *RefTy);
1727 
1728   Address EmitLoadOfPointer(Address Ptr, const PointerType *PtrTy,
1729                             AlignmentSource *Source = nullptr);
1730   LValue EmitLoadOfPointerLValue(Address Ptr, const PointerType *PtrTy);
1731 
1732   /// CreateTempAlloca - This creates a alloca and inserts it into the entry
1733   /// block. The caller is responsible for setting an appropriate alignment on
1734   /// the alloca.
1735   llvm::AllocaInst *CreateTempAlloca(llvm::Type *Ty,
1736                                      const Twine &Name = "tmp");
1737   Address CreateTempAlloca(llvm::Type *Ty, CharUnits align,
1738                            const Twine &Name = "tmp");
1739 
1740   /// CreateDefaultAlignedTempAlloca - This creates an alloca with the
1741   /// default ABI alignment of the given LLVM type.
1742   ///
1743   /// IMPORTANT NOTE: This is *not* generally the right alignment for
1744   /// any given AST type that happens to have been lowered to the
1745   /// given IR type.  This should only ever be used for function-local,
1746   /// IR-driven manipulations like saving and restoring a value.  Do
1747   /// not hand this address off to arbitrary IRGen routines, and especially
1748   /// do not pass it as an argument to a function that might expect a
1749   /// properly ABI-aligned value.
1750   Address CreateDefaultAlignTempAlloca(llvm::Type *Ty,
1751                                        const Twine &Name = "tmp");
1752 
1753   /// InitTempAlloca - Provide an initial value for the given alloca which
1754   /// will be observable at all locations in the function.
1755   ///
1756   /// The address should be something that was returned from one of
1757   /// the CreateTempAlloca or CreateMemTemp routines, and the
1758   /// initializer must be valid in the entry block (i.e. it must
1759   /// either be a constant or an argument value).
1760   void InitTempAlloca(Address Alloca, llvm::Value *Value);
1761 
1762   /// CreateIRTemp - Create a temporary IR object of the given type, with
1763   /// appropriate alignment. This routine should only be used when an temporary
1764   /// value needs to be stored into an alloca (for example, to avoid explicit
1765   /// PHI construction), but the type is the IR type, not the type appropriate
1766   /// for storing in memory.
1767   ///
1768   /// That is, this is exactly equivalent to CreateMemTemp, but calling
1769   /// ConvertType instead of ConvertTypeForMem.
1770   Address CreateIRTemp(QualType T, const Twine &Name = "tmp");
1771 
1772   /// CreateMemTemp - Create a temporary memory object of the given type, with
1773   /// appropriate alignment.
1774   Address CreateMemTemp(QualType T, const Twine &Name = "tmp");
1775   Address CreateMemTemp(QualType T, CharUnits Align, const Twine &Name = "tmp");
1776 
1777   /// CreateAggTemp - Create a temporary memory object for the given
1778   /// aggregate type.
1779   AggValueSlot CreateAggTemp(QualType T, const Twine &Name = "tmp") {
1780     return AggValueSlot::forAddr(CreateMemTemp(T, Name),
1781                                  T.getQualifiers(),
1782                                  AggValueSlot::IsNotDestructed,
1783                                  AggValueSlot::DoesNotNeedGCBarriers,
1784                                  AggValueSlot::IsNotAliased);
1785   }
1786 
1787   /// Emit a cast to void* in the appropriate address space.
1788   llvm::Value *EmitCastToVoidPtr(llvm::Value *value);
1789 
1790   /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
1791   /// expression and compare the result against zero, returning an Int1Ty value.
1792   llvm::Value *EvaluateExprAsBool(const Expr *E);
1793 
1794   /// EmitIgnoredExpr - Emit an expression in a context which ignores the result.
1795   void EmitIgnoredExpr(const Expr *E);
1796 
1797   /// EmitAnyExpr - Emit code to compute the specified expression which can have
1798   /// any type.  The result is returned as an RValue struct.  If this is an
1799   /// aggregate expression, the aggloc/agglocvolatile arguments indicate where
1800   /// the result should be returned.
1801   ///
1802   /// \param ignoreResult True if the resulting value isn't used.
1803   RValue EmitAnyExpr(const Expr *E,
1804                      AggValueSlot aggSlot = AggValueSlot::ignored(),
1805                      bool ignoreResult = false);
1806 
1807   // EmitVAListRef - Emit a "reference" to a va_list; this is either the address
1808   // or the value of the expression, depending on how va_list is defined.
1809   Address EmitVAListRef(const Expr *E);
1810 
1811   /// Emit a "reference" to a __builtin_ms_va_list; this is
1812   /// always the value of the expression, because a __builtin_ms_va_list is a
1813   /// pointer to a char.
1814   Address EmitMSVAListRef(const Expr *E);
1815 
1816   /// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
1817   /// always be accessible even if no aggregate location is provided.
1818   RValue EmitAnyExprToTemp(const Expr *E);
1819 
1820   /// EmitAnyExprToMem - Emits the code necessary to evaluate an
1821   /// arbitrary expression into the given memory location.
1822   void EmitAnyExprToMem(const Expr *E, Address Location,
1823                         Qualifiers Quals, bool IsInitializer);
1824 
1825   void EmitAnyExprToExn(const Expr *E, Address Addr);
1826 
1827   /// EmitExprAsInit - Emits the code necessary to initialize a
1828   /// location in memory with the given initializer.
1829   void EmitExprAsInit(const Expr *init, const ValueDecl *D, LValue lvalue,
1830                       bool capturedByInit);
1831 
1832   /// hasVolatileMember - returns true if aggregate type has a volatile
1833   /// member.
1834   bool hasVolatileMember(QualType T) {
1835     if (const RecordType *RT = T->getAs<RecordType>()) {
1836       const RecordDecl *RD = cast<RecordDecl>(RT->getDecl());
1837       return RD->hasVolatileMember();
1838     }
1839     return false;
1840   }
1841   /// EmitAggregateCopy - Emit an aggregate assignment.
1842   ///
1843   /// The difference to EmitAggregateCopy is that tail padding is not copied.
1844   /// This is required for correctness when assigning non-POD structures in C++.
1845   void EmitAggregateAssign(Address DestPtr, Address SrcPtr,
1846                            QualType EltTy) {
1847     bool IsVolatile = hasVolatileMember(EltTy);
1848     EmitAggregateCopy(DestPtr, SrcPtr, EltTy, IsVolatile, true);
1849   }
1850 
1851   void EmitAggregateCopyCtor(Address DestPtr, Address SrcPtr,
1852                              QualType DestTy, QualType SrcTy) {
1853     EmitAggregateCopy(DestPtr, SrcPtr, SrcTy, /*IsVolatile=*/false,
1854                       /*IsAssignment=*/false);
1855   }
1856 
1857   /// EmitAggregateCopy - Emit an aggregate copy.
1858   ///
1859   /// \param isVolatile - True iff either the source or the destination is
1860   /// volatile.
1861   /// \param isAssignment - If false, allow padding to be copied.  This often
1862   /// yields more efficient.
1863   void EmitAggregateCopy(Address DestPtr, Address SrcPtr,
1864                          QualType EltTy, bool isVolatile=false,
1865                          bool isAssignment = false);
1866 
1867   /// GetAddrOfLocalVar - Return the address of a local variable.
1868   Address GetAddrOfLocalVar(const VarDecl *VD) {
1869     auto it = LocalDeclMap.find(VD);
1870     assert(it != LocalDeclMap.end() &&
1871            "Invalid argument to GetAddrOfLocalVar(), no decl!");
1872     return it->second;
1873   }
1874 
1875   /// getOpaqueLValueMapping - Given an opaque value expression (which
1876   /// must be mapped to an l-value), return its mapping.
1877   const LValue &getOpaqueLValueMapping(const OpaqueValueExpr *e) {
1878     assert(OpaqueValueMapping::shouldBindAsLValue(e));
1879 
1880     llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
1881       it = OpaqueLValues.find(e);
1882     assert(it != OpaqueLValues.end() && "no mapping for opaque value!");
1883     return it->second;
1884   }
1885 
1886   /// getOpaqueRValueMapping - Given an opaque value expression (which
1887   /// must be mapped to an r-value), return its mapping.
1888   const RValue &getOpaqueRValueMapping(const OpaqueValueExpr *e) {
1889     assert(!OpaqueValueMapping::shouldBindAsLValue(e));
1890 
1891     llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
1892       it = OpaqueRValues.find(e);
1893     assert(it != OpaqueRValues.end() && "no mapping for opaque value!");
1894     return it->second;
1895   }
1896 
1897   /// getAccessedFieldNo - Given an encoded value and a result number, return
1898   /// the input field number being accessed.
1899   static unsigned getAccessedFieldNo(unsigned Idx, const llvm::Constant *Elts);
1900 
1901   llvm::BlockAddress *GetAddrOfLabel(const LabelDecl *L);
1902   llvm::BasicBlock *GetIndirectGotoBlock();
1903 
1904   /// EmitNullInitialization - Generate code to set a value of the given type to
1905   /// null, If the type contains data member pointers, they will be initialized
1906   /// to -1 in accordance with the Itanium C++ ABI.
1907   void EmitNullInitialization(Address DestPtr, QualType Ty);
1908 
1909   /// Emits a call to an LLVM variable-argument intrinsic, either
1910   /// \c llvm.va_start or \c llvm.va_end.
1911   /// \param ArgValue A reference to the \c va_list as emitted by either
1912   /// \c EmitVAListRef or \c EmitMSVAListRef.
1913   /// \param IsStart If \c true, emits a call to \c llvm.va_start; otherwise,
1914   /// calls \c llvm.va_end.
1915   llvm::Value *EmitVAStartEnd(llvm::Value *ArgValue, bool IsStart);
1916 
1917   /// Generate code to get an argument from the passed in pointer
1918   /// and update it accordingly.
1919   /// \param VE The \c VAArgExpr for which to generate code.
1920   /// \param VAListAddr Receives a reference to the \c va_list as emitted by
1921   /// either \c EmitVAListRef or \c EmitMSVAListRef.
1922   /// \returns A pointer to the argument.
1923   // FIXME: We should be able to get rid of this method and use the va_arg
1924   // instruction in LLVM instead once it works well enough.
1925   Address EmitVAArg(VAArgExpr *VE, Address &VAListAddr);
1926 
1927   /// emitArrayLength - Compute the length of an array, even if it's a
1928   /// VLA, and drill down to the base element type.
1929   llvm::Value *emitArrayLength(const ArrayType *arrayType,
1930                                QualType &baseType,
1931                                Address &addr);
1932 
1933   /// EmitVLASize - Capture all the sizes for the VLA expressions in
1934   /// the given variably-modified type and store them in the VLASizeMap.
1935   ///
1936   /// This function can be called with a null (unreachable) insert point.
1937   void EmitVariablyModifiedType(QualType Ty);
1938 
1939   /// getVLASize - Returns an LLVM value that corresponds to the size,
1940   /// in non-variably-sized elements, of a variable length array type,
1941   /// plus that largest non-variably-sized element type.  Assumes that
1942   /// the type has already been emitted with EmitVariablyModifiedType.
1943   std::pair<llvm::Value*,QualType> getVLASize(const VariableArrayType *vla);
1944   std::pair<llvm::Value*,QualType> getVLASize(QualType vla);
1945 
1946   /// LoadCXXThis - Load the value of 'this'. This function is only valid while
1947   /// generating code for an C++ member function.
1948   llvm::Value *LoadCXXThis() {
1949     assert(CXXThisValue && "no 'this' value for this function");
1950     return CXXThisValue;
1951   }
1952   Address LoadCXXThisAddress();
1953 
1954   /// LoadCXXVTT - Load the VTT parameter to base constructors/destructors have
1955   /// virtual bases.
1956   // FIXME: Every place that calls LoadCXXVTT is something
1957   // that needs to be abstracted properly.
1958   llvm::Value *LoadCXXVTT() {
1959     assert(CXXStructorImplicitParamValue && "no VTT value for this function");
1960     return CXXStructorImplicitParamValue;
1961   }
1962 
1963   /// GetAddressOfBaseOfCompleteClass - Convert the given pointer to a
1964   /// complete class to the given direct base.
1965   Address
1966   GetAddressOfDirectBaseInCompleteClass(Address Value,
1967                                         const CXXRecordDecl *Derived,
1968                                         const CXXRecordDecl *Base,
1969                                         bool BaseIsVirtual);
1970 
1971   static bool ShouldNullCheckClassCastValue(const CastExpr *Cast);
1972 
1973   /// GetAddressOfBaseClass - This function will add the necessary delta to the
1974   /// load of 'this' and returns address of the base class.
1975   Address GetAddressOfBaseClass(Address Value,
1976                                 const CXXRecordDecl *Derived,
1977                                 CastExpr::path_const_iterator PathBegin,
1978                                 CastExpr::path_const_iterator PathEnd,
1979                                 bool NullCheckValue, SourceLocation Loc);
1980 
1981   Address GetAddressOfDerivedClass(Address Value,
1982                                    const CXXRecordDecl *Derived,
1983                                    CastExpr::path_const_iterator PathBegin,
1984                                    CastExpr::path_const_iterator PathEnd,
1985                                    bool NullCheckValue);
1986 
1987   /// GetVTTParameter - Return the VTT parameter that should be passed to a
1988   /// base constructor/destructor with virtual bases.
1989   /// FIXME: VTTs are Itanium ABI-specific, so the definition should move
1990   /// to ItaniumCXXABI.cpp together with all the references to VTT.
1991   llvm::Value *GetVTTParameter(GlobalDecl GD, bool ForVirtualBase,
1992                                bool Delegating);
1993 
1994   void EmitDelegateCXXConstructorCall(const CXXConstructorDecl *Ctor,
1995                                       CXXCtorType CtorType,
1996                                       const FunctionArgList &Args,
1997                                       SourceLocation Loc);
1998   // It's important not to confuse this and the previous function. Delegating
1999   // constructors are the C++0x feature. The constructor delegate optimization
2000   // is used to reduce duplication in the base and complete consturctors where
2001   // they are substantially the same.
2002   void EmitDelegatingCXXConstructorCall(const CXXConstructorDecl *Ctor,
2003                                         const FunctionArgList &Args);
2004 
2005   /// Emit a call to an inheriting constructor (that is, one that invokes a
2006   /// constructor inherited from a base class) by inlining its definition. This
2007   /// is necessary if the ABI does not support forwarding the arguments to the
2008   /// base class constructor (because they're variadic or similar).
2009   void EmitInlinedInheritingCXXConstructorCall(const CXXConstructorDecl *Ctor,
2010                                                CXXCtorType CtorType,
2011                                                bool ForVirtualBase,
2012                                                bool Delegating,
2013                                                CallArgList &Args);
2014 
2015   /// Emit a call to a constructor inherited from a base class, passing the
2016   /// current constructor's arguments along unmodified (without even making
2017   /// a copy).
2018   void EmitInheritedCXXConstructorCall(const CXXConstructorDecl *D,
2019                                        bool ForVirtualBase, Address This,
2020                                        bool InheritedFromVBase,
2021                                        const CXXInheritedCtorInitExpr *E);
2022 
2023   void EmitCXXConstructorCall(const CXXConstructorDecl *D, CXXCtorType Type,
2024                               bool ForVirtualBase, bool Delegating,
2025                               Address This, const CXXConstructExpr *E);
2026 
2027   void EmitCXXConstructorCall(const CXXConstructorDecl *D, CXXCtorType Type,
2028                               bool ForVirtualBase, bool Delegating,
2029                               Address This, CallArgList &Args);
2030 
2031   /// Emit assumption load for all bases. Requires to be be called only on
2032   /// most-derived class and not under construction of the object.
2033   void EmitVTableAssumptionLoads(const CXXRecordDecl *ClassDecl, Address This);
2034 
2035   /// Emit assumption that vptr load == global vtable.
2036   void EmitVTableAssumptionLoad(const VPtr &vptr, Address This);
2037 
2038   void EmitSynthesizedCXXCopyCtorCall(const CXXConstructorDecl *D,
2039                                       Address This, Address Src,
2040                                       const CXXConstructExpr *E);
2041 
2042   void EmitCXXAggrConstructorCall(const CXXConstructorDecl *D,
2043                                   const ArrayType *ArrayTy,
2044                                   Address ArrayPtr,
2045                                   const CXXConstructExpr *E,
2046                                   bool ZeroInitialization = false);
2047 
2048   void EmitCXXAggrConstructorCall(const CXXConstructorDecl *D,
2049                                   llvm::Value *NumElements,
2050                                   Address ArrayPtr,
2051                                   const CXXConstructExpr *E,
2052                                   bool ZeroInitialization = false);
2053 
2054   static Destroyer destroyCXXObject;
2055 
2056   void EmitCXXDestructorCall(const CXXDestructorDecl *D, CXXDtorType Type,
2057                              bool ForVirtualBase, bool Delegating,
2058                              Address This);
2059 
2060   void EmitNewArrayInitializer(const CXXNewExpr *E, QualType elementType,
2061                                llvm::Type *ElementTy, Address NewPtr,
2062                                llvm::Value *NumElements,
2063                                llvm::Value *AllocSizeWithoutCookie);
2064 
2065   void EmitCXXTemporary(const CXXTemporary *Temporary, QualType TempType,
2066                         Address Ptr);
2067 
2068   llvm::Value *EmitLifetimeStart(uint64_t Size, llvm::Value *Addr);
2069   void EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr);
2070 
2071   llvm::Value *EmitCXXNewExpr(const CXXNewExpr *E);
2072   void EmitCXXDeleteExpr(const CXXDeleteExpr *E);
2073 
2074   void EmitDeleteCall(const FunctionDecl *DeleteFD, llvm::Value *Ptr,
2075                       QualType DeleteTy, llvm::Value *NumElements = nullptr,
2076                       CharUnits CookieSize = CharUnits());
2077 
2078   RValue EmitBuiltinNewDeleteCall(const FunctionProtoType *Type,
2079                                   const Expr *Arg, bool IsDelete);
2080 
2081   llvm::Value *EmitCXXTypeidExpr(const CXXTypeidExpr *E);
2082   llvm::Value *EmitDynamicCast(Address V, const CXXDynamicCastExpr *DCE);
2083   Address EmitCXXUuidofExpr(const CXXUuidofExpr *E);
2084 
2085   /// \brief Situations in which we might emit a check for the suitability of a
2086   ///        pointer or glvalue.
2087   enum TypeCheckKind {
2088     /// Checking the operand of a load. Must be suitably sized and aligned.
2089     TCK_Load,
2090     /// Checking the destination of a store. Must be suitably sized and aligned.
2091     TCK_Store,
2092     /// Checking the bound value in a reference binding. Must be suitably sized
2093     /// and aligned, but is not required to refer to an object (until the
2094     /// reference is used), per core issue 453.
2095     TCK_ReferenceBinding,
2096     /// Checking the object expression in a non-static data member access. Must
2097     /// be an object within its lifetime.
2098     TCK_MemberAccess,
2099     /// Checking the 'this' pointer for a call to a non-static member function.
2100     /// Must be an object within its lifetime.
2101     TCK_MemberCall,
2102     /// Checking the 'this' pointer for a constructor call.
2103     TCK_ConstructorCall,
2104     /// Checking the operand of a static_cast to a derived pointer type. Must be
2105     /// null or an object within its lifetime.
2106     TCK_DowncastPointer,
2107     /// Checking the operand of a static_cast to a derived reference type. Must
2108     /// be an object within its lifetime.
2109     TCK_DowncastReference,
2110     /// Checking the operand of a cast to a base object. Must be suitably sized
2111     /// and aligned.
2112     TCK_Upcast,
2113     /// Checking the operand of a cast to a virtual base object. Must be an
2114     /// object within its lifetime.
2115     TCK_UpcastToVirtualBase
2116   };
2117 
2118   /// \brief Whether any type-checking sanitizers are enabled. If \c false,
2119   /// calls to EmitTypeCheck can be skipped.
2120   bool sanitizePerformTypeCheck() const;
2121 
2122   /// \brief Emit a check that \p V is the address of storage of the
2123   /// appropriate size and alignment for an object of type \p Type.
2124   void EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc, llvm::Value *V,
2125                      QualType Type, CharUnits Alignment = CharUnits::Zero(),
2126                      bool SkipNullCheck = false);
2127 
2128   /// \brief Emit a check that \p Base points into an array object, which
2129   /// we can access at index \p Index. \p Accessed should be \c false if we
2130   /// this expression is used as an lvalue, for instance in "&Arr[Idx]".
2131   void EmitBoundsCheck(const Expr *E, const Expr *Base, llvm::Value *Index,
2132                        QualType IndexType, bool Accessed);
2133 
2134   llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
2135                                        bool isInc, bool isPre);
2136   ComplexPairTy EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
2137                                          bool isInc, bool isPre);
2138 
2139   void EmitAlignmentAssumption(llvm::Value *PtrValue, unsigned Alignment,
2140                                llvm::Value *OffsetValue = nullptr) {
2141     Builder.CreateAlignmentAssumption(CGM.getDataLayout(), PtrValue, Alignment,
2142                                       OffsetValue);
2143   }
2144 
2145   /// Converts Location to a DebugLoc, if debug information is enabled.
2146   llvm::DebugLoc SourceLocToDebugLoc(SourceLocation Location);
2147 
2148 
2149   //===--------------------------------------------------------------------===//
2150   //                            Declaration Emission
2151   //===--------------------------------------------------------------------===//
2152 
2153   /// EmitDecl - Emit a declaration.
2154   ///
2155   /// This function can be called with a null (unreachable) insert point.
2156   void EmitDecl(const Decl &D);
2157 
2158   /// EmitVarDecl - Emit a local variable declaration.
2159   ///
2160   /// This function can be called with a null (unreachable) insert point.
2161   void EmitVarDecl(const VarDecl &D);
2162 
2163   void EmitScalarInit(const Expr *init, const ValueDecl *D, LValue lvalue,
2164                       bool capturedByInit);
2165 
2166   typedef void SpecialInitFn(CodeGenFunction &Init, const VarDecl &D,
2167                              llvm::Value *Address);
2168 
2169   /// \brief Determine whether the given initializer is trivial in the sense
2170   /// that it requires no code to be generated.
2171   bool isTrivialInitializer(const Expr *Init);
2172 
2173   /// EmitAutoVarDecl - Emit an auto variable declaration.
2174   ///
2175   /// This function can be called with a null (unreachable) insert point.
2176   void EmitAutoVarDecl(const VarDecl &D);
2177 
2178   class AutoVarEmission {
2179     friend class CodeGenFunction;
2180 
2181     const VarDecl *Variable;
2182 
2183     /// The address of the alloca.  Invalid if the variable was emitted
2184     /// as a global constant.
2185     Address Addr;
2186 
2187     llvm::Value *NRVOFlag;
2188 
2189     /// True if the variable is a __block variable.
2190     bool IsByRef;
2191 
2192     /// True if the variable is of aggregate type and has a constant
2193     /// initializer.
2194     bool IsConstantAggregate;
2195 
2196     /// Non-null if we should use lifetime annotations.
2197     llvm::Value *SizeForLifetimeMarkers;
2198 
2199     struct Invalid {};
2200     AutoVarEmission(Invalid) : Variable(nullptr), Addr(Address::invalid()) {}
2201 
2202     AutoVarEmission(const VarDecl &variable)
2203       : Variable(&variable), Addr(Address::invalid()), NRVOFlag(nullptr),
2204         IsByRef(false), IsConstantAggregate(false),
2205         SizeForLifetimeMarkers(nullptr) {}
2206 
2207     bool wasEmittedAsGlobal() const { return !Addr.isValid(); }
2208 
2209   public:
2210     static AutoVarEmission invalid() { return AutoVarEmission(Invalid()); }
2211 
2212     bool useLifetimeMarkers() const {
2213       return SizeForLifetimeMarkers != nullptr;
2214     }
2215     llvm::Value *getSizeForLifetimeMarkers() const {
2216       assert(useLifetimeMarkers());
2217       return SizeForLifetimeMarkers;
2218     }
2219 
2220     /// Returns the raw, allocated address, which is not necessarily
2221     /// the address of the object itself.
2222     Address getAllocatedAddress() const {
2223       return Addr;
2224     }
2225 
2226     /// Returns the address of the object within this declaration.
2227     /// Note that this does not chase the forwarding pointer for
2228     /// __block decls.
2229     Address getObjectAddress(CodeGenFunction &CGF) const {
2230       if (!IsByRef) return Addr;
2231 
2232       return CGF.emitBlockByrefAddress(Addr, Variable, /*forward*/ false);
2233     }
2234   };
2235   AutoVarEmission EmitAutoVarAlloca(const VarDecl &var);
2236   void EmitAutoVarInit(const AutoVarEmission &emission);
2237   void EmitAutoVarCleanups(const AutoVarEmission &emission);
2238   void emitAutoVarTypeCleanup(const AutoVarEmission &emission,
2239                               QualType::DestructionKind dtorKind);
2240 
2241   void EmitStaticVarDecl(const VarDecl &D,
2242                          llvm::GlobalValue::LinkageTypes Linkage);
2243 
2244   class ParamValue {
2245     llvm::Value *Value;
2246     unsigned Alignment;
2247     ParamValue(llvm::Value *V, unsigned A) : Value(V), Alignment(A) {}
2248   public:
2249     static ParamValue forDirect(llvm::Value *value) {
2250       return ParamValue(value, 0);
2251     }
2252     static ParamValue forIndirect(Address addr) {
2253       assert(!addr.getAlignment().isZero());
2254       return ParamValue(addr.getPointer(), addr.getAlignment().getQuantity());
2255     }
2256 
2257     bool isIndirect() const { return Alignment != 0; }
2258     llvm::Value *getAnyValue() const { return Value; }
2259 
2260     llvm::Value *getDirectValue() const {
2261       assert(!isIndirect());
2262       return Value;
2263     }
2264 
2265     Address getIndirectAddress() const {
2266       assert(isIndirect());
2267       return Address(Value, CharUnits::fromQuantity(Alignment));
2268     }
2269   };
2270 
2271   /// EmitParmDecl - Emit a ParmVarDecl or an ImplicitParamDecl.
2272   void EmitParmDecl(const VarDecl &D, ParamValue Arg, unsigned ArgNo);
2273 
2274   /// protectFromPeepholes - Protect a value that we're intending to
2275   /// store to the side, but which will probably be used later, from
2276   /// aggressive peepholing optimizations that might delete it.
2277   ///
2278   /// Pass the result to unprotectFromPeepholes to declare that
2279   /// protection is no longer required.
2280   ///
2281   /// There's no particular reason why this shouldn't apply to
2282   /// l-values, it's just that no existing peepholes work on pointers.
2283   PeepholeProtection protectFromPeepholes(RValue rvalue);
2284   void unprotectFromPeepholes(PeepholeProtection protection);
2285 
2286   //===--------------------------------------------------------------------===//
2287   //                             Statement Emission
2288   //===--------------------------------------------------------------------===//
2289 
2290   /// EmitStopPoint - Emit a debug stoppoint if we are emitting debug info.
2291   void EmitStopPoint(const Stmt *S);
2292 
2293   /// EmitStmt - Emit the code for the statement \arg S. It is legal to call
2294   /// this function even if there is no current insertion point.
2295   ///
2296   /// This function may clear the current insertion point; callers should use
2297   /// EnsureInsertPoint if they wish to subsequently generate code without first
2298   /// calling EmitBlock, EmitBranch, or EmitStmt.
2299   void EmitStmt(const Stmt *S);
2300 
2301   /// EmitSimpleStmt - Try to emit a "simple" statement which does not
2302   /// necessarily require an insertion point or debug information; typically
2303   /// because the statement amounts to a jump or a container of other
2304   /// statements.
2305   ///
2306   /// \return True if the statement was handled.
2307   bool EmitSimpleStmt(const Stmt *S);
2308 
2309   Address EmitCompoundStmt(const CompoundStmt &S, bool GetLast = false,
2310                            AggValueSlot AVS = AggValueSlot::ignored());
2311   Address EmitCompoundStmtWithoutScope(const CompoundStmt &S,
2312                                        bool GetLast = false,
2313                                        AggValueSlot AVS =
2314                                                 AggValueSlot::ignored());
2315 
2316   /// EmitLabel - Emit the block for the given label. It is legal to call this
2317   /// function even if there is no current insertion point.
2318   void EmitLabel(const LabelDecl *D); // helper for EmitLabelStmt.
2319 
2320   void EmitLabelStmt(const LabelStmt &S);
2321   void EmitAttributedStmt(const AttributedStmt &S);
2322   void EmitGotoStmt(const GotoStmt &S);
2323   void EmitIndirectGotoStmt(const IndirectGotoStmt &S);
2324   void EmitIfStmt(const IfStmt &S);
2325 
2326   void EmitWhileStmt(const WhileStmt &S,
2327                      ArrayRef<const Attr *> Attrs = None);
2328   void EmitDoStmt(const DoStmt &S, ArrayRef<const Attr *> Attrs = None);
2329   void EmitForStmt(const ForStmt &S,
2330                    ArrayRef<const Attr *> Attrs = None);
2331   void EmitReturnStmt(const ReturnStmt &S);
2332   void EmitDeclStmt(const DeclStmt &S);
2333   void EmitBreakStmt(const BreakStmt &S);
2334   void EmitContinueStmt(const ContinueStmt &S);
2335   void EmitSwitchStmt(const SwitchStmt &S);
2336   void EmitDefaultStmt(const DefaultStmt &S);
2337   void EmitCaseStmt(const CaseStmt &S);
2338   void EmitCaseStmtRange(const CaseStmt &S);
2339   void EmitAsmStmt(const AsmStmt &S);
2340 
2341   void EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S);
2342   void EmitObjCAtTryStmt(const ObjCAtTryStmt &S);
2343   void EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S);
2344   void EmitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt &S);
2345   void EmitObjCAutoreleasePoolStmt(const ObjCAutoreleasePoolStmt &S);
2346 
2347   void EmitCoroutineBody(const CoroutineBodyStmt &S);
2348   RValue EmitCoroutineIntrinsic(const CallExpr *E, unsigned int IID);
2349 
2350   void EnterCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
2351   void ExitCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
2352 
2353   void EmitCXXTryStmt(const CXXTryStmt &S);
2354   void EmitSEHTryStmt(const SEHTryStmt &S);
2355   void EmitSEHLeaveStmt(const SEHLeaveStmt &S);
2356   void EnterSEHTryStmt(const SEHTryStmt &S);
2357   void ExitSEHTryStmt(const SEHTryStmt &S);
2358 
2359   void startOutlinedSEHHelper(CodeGenFunction &ParentCGF, bool IsFilter,
2360                               const Stmt *OutlinedStmt);
2361 
2362   llvm::Function *GenerateSEHFilterFunction(CodeGenFunction &ParentCGF,
2363                                             const SEHExceptStmt &Except);
2364 
2365   llvm::Function *GenerateSEHFinallyFunction(CodeGenFunction &ParentCGF,
2366                                              const SEHFinallyStmt &Finally);
2367 
2368   void EmitSEHExceptionCodeSave(CodeGenFunction &ParentCGF,
2369                                 llvm::Value *ParentFP,
2370                                 llvm::Value *EntryEBP);
2371   llvm::Value *EmitSEHExceptionCode();
2372   llvm::Value *EmitSEHExceptionInfo();
2373   llvm::Value *EmitSEHAbnormalTermination();
2374 
2375   /// Scan the outlined statement for captures from the parent function. For
2376   /// each capture, mark the capture as escaped and emit a call to
2377   /// llvm.localrecover. Insert the localrecover result into the LocalDeclMap.
2378   void EmitCapturedLocals(CodeGenFunction &ParentCGF, const Stmt *OutlinedStmt,
2379                           bool IsFilter);
2380 
2381   /// Recovers the address of a local in a parent function. ParentVar is the
2382   /// address of the variable used in the immediate parent function. It can
2383   /// either be an alloca or a call to llvm.localrecover if there are nested
2384   /// outlined functions. ParentFP is the frame pointer of the outermost parent
2385   /// frame.
2386   Address recoverAddrOfEscapedLocal(CodeGenFunction &ParentCGF,
2387                                     Address ParentVar,
2388                                     llvm::Value *ParentFP);
2389 
2390   void EmitCXXForRangeStmt(const CXXForRangeStmt &S,
2391                            ArrayRef<const Attr *> Attrs = None);
2392 
2393   /// Returns calculated size of the specified type.
2394   llvm::Value *getTypeSize(QualType Ty);
2395   LValue InitCapturedStruct(const CapturedStmt &S);
2396   llvm::Function *EmitCapturedStmt(const CapturedStmt &S, CapturedRegionKind K);
2397   llvm::Function *GenerateCapturedStmtFunction(const CapturedStmt &S);
2398   Address GenerateCapturedStmtArgument(const CapturedStmt &S);
2399   llvm::Function *GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S);
2400   void GenerateOpenMPCapturedVars(const CapturedStmt &S,
2401                                   SmallVectorImpl<llvm::Value *> &CapturedVars);
2402   void emitOMPSimpleStore(LValue LVal, RValue RVal, QualType RValTy,
2403                           SourceLocation Loc);
2404   /// \brief Perform element by element copying of arrays with type \a
2405   /// OriginalType from \a SrcAddr to \a DestAddr using copying procedure
2406   /// generated by \a CopyGen.
2407   ///
2408   /// \param DestAddr Address of the destination array.
2409   /// \param SrcAddr Address of the source array.
2410   /// \param OriginalType Type of destination and source arrays.
2411   /// \param CopyGen Copying procedure that copies value of single array element
2412   /// to another single array element.
2413   void EmitOMPAggregateAssign(
2414       Address DestAddr, Address SrcAddr, QualType OriginalType,
2415       const llvm::function_ref<void(Address, Address)> &CopyGen);
2416   /// \brief Emit proper copying of data from one variable to another.
2417   ///
2418   /// \param OriginalType Original type of the copied variables.
2419   /// \param DestAddr Destination address.
2420   /// \param SrcAddr Source address.
2421   /// \param DestVD Destination variable used in \a CopyExpr (for arrays, has
2422   /// type of the base array element).
2423   /// \param SrcVD Source variable used in \a CopyExpr (for arrays, has type of
2424   /// the base array element).
2425   /// \param Copy Actual copygin expression for copying data from \a SrcVD to \a
2426   /// DestVD.
2427   void EmitOMPCopy(QualType OriginalType,
2428                    Address DestAddr, Address SrcAddr,
2429                    const VarDecl *DestVD, const VarDecl *SrcVD,
2430                    const Expr *Copy);
2431   /// \brief Emit atomic update code for constructs: \a X = \a X \a BO \a E or
2432   /// \a X = \a E \a BO \a E.
2433   ///
2434   /// \param X Value to be updated.
2435   /// \param E Update value.
2436   /// \param BO Binary operation for update operation.
2437   /// \param IsXLHSInRHSPart true if \a X is LHS in RHS part of the update
2438   /// expression, false otherwise.
2439   /// \param AO Atomic ordering of the generated atomic instructions.
2440   /// \param CommonGen Code generator for complex expressions that cannot be
2441   /// expressed through atomicrmw instruction.
2442   /// \returns <true, OldAtomicValue> if simple 'atomicrmw' instruction was
2443   /// generated, <false, RValue::get(nullptr)> otherwise.
2444   std::pair<bool, RValue> EmitOMPAtomicSimpleUpdateExpr(
2445       LValue X, RValue E, BinaryOperatorKind BO, bool IsXLHSInRHSPart,
2446       llvm::AtomicOrdering AO, SourceLocation Loc,
2447       const llvm::function_ref<RValue(RValue)> &CommonGen);
2448   bool EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
2449                                  OMPPrivateScope &PrivateScope);
2450   void EmitOMPPrivateClause(const OMPExecutableDirective &D,
2451                             OMPPrivateScope &PrivateScope);
2452   void EmitOMPUseDevicePtrClause(
2453       const OMPClause &C, OMPPrivateScope &PrivateScope,
2454       const llvm::DenseMap<const ValueDecl *, Address> &CaptureDeviceAddrMap);
2455   /// \brief Emit code for copyin clause in \a D directive. The next code is
2456   /// generated at the start of outlined functions for directives:
2457   /// \code
2458   /// threadprivate_var1 = master_threadprivate_var1;
2459   /// operator=(threadprivate_var2, master_threadprivate_var2);
2460   /// ...
2461   /// __kmpc_barrier(&loc, global_tid);
2462   /// \endcode
2463   ///
2464   /// \param D OpenMP directive possibly with 'copyin' clause(s).
2465   /// \returns true if at least one copyin variable is found, false otherwise.
2466   bool EmitOMPCopyinClause(const OMPExecutableDirective &D);
2467   /// \brief Emit initial code for lastprivate variables. If some variable is
2468   /// not also firstprivate, then the default initialization is used. Otherwise
2469   /// initialization of this variable is performed by EmitOMPFirstprivateClause
2470   /// method.
2471   ///
2472   /// \param D Directive that may have 'lastprivate' directives.
2473   /// \param PrivateScope Private scope for capturing lastprivate variables for
2474   /// proper codegen in internal captured statement.
2475   ///
2476   /// \returns true if there is at least one lastprivate variable, false
2477   /// otherwise.
2478   bool EmitOMPLastprivateClauseInit(const OMPExecutableDirective &D,
2479                                     OMPPrivateScope &PrivateScope);
2480   /// \brief Emit final copying of lastprivate values to original variables at
2481   /// the end of the worksharing or simd directive.
2482   ///
2483   /// \param D Directive that has at least one 'lastprivate' directives.
2484   /// \param IsLastIterCond Boolean condition that must be set to 'i1 true' if
2485   /// it is the last iteration of the loop code in associated directive, or to
2486   /// 'i1 false' otherwise. If this item is nullptr, no final check is required.
2487   void EmitOMPLastprivateClauseFinal(const OMPExecutableDirective &D,
2488                                      bool NoFinals,
2489                                      llvm::Value *IsLastIterCond = nullptr);
2490   /// Emit initial code for linear clauses.
2491   void EmitOMPLinearClause(const OMPLoopDirective &D,
2492                            CodeGenFunction::OMPPrivateScope &PrivateScope);
2493   /// Emit final code for linear clauses.
2494   /// \param CondGen Optional conditional code for final part of codegen for
2495   /// linear clause.
2496   void EmitOMPLinearClauseFinal(
2497       const OMPLoopDirective &D,
2498       const llvm::function_ref<llvm::Value *(CodeGenFunction &)> &CondGen);
2499   /// \brief Emit initial code for reduction variables. Creates reduction copies
2500   /// and initializes them with the values according to OpenMP standard.
2501   ///
2502   /// \param D Directive (possibly) with the 'reduction' clause.
2503   /// \param PrivateScope Private scope for capturing reduction variables for
2504   /// proper codegen in internal captured statement.
2505   ///
2506   void EmitOMPReductionClauseInit(const OMPExecutableDirective &D,
2507                                   OMPPrivateScope &PrivateScope);
2508   /// \brief Emit final update of reduction values to original variables at
2509   /// the end of the directive.
2510   ///
2511   /// \param D Directive that has at least one 'reduction' directives.
2512   void EmitOMPReductionClauseFinal(const OMPExecutableDirective &D);
2513   /// \brief Emit initial code for linear variables. Creates private copies
2514   /// and initializes them with the values according to OpenMP standard.
2515   ///
2516   /// \param D Directive (possibly) with the 'linear' clause.
2517   void EmitOMPLinearClauseInit(const OMPLoopDirective &D);
2518 
2519   typedef const llvm::function_ref<void(CodeGenFunction & /*CGF*/,
2520                                         llvm::Value * /*OutlinedFn*/,
2521                                         const OMPTaskDataTy & /*Data*/)>
2522       TaskGenTy;
2523   void EmitOMPTaskBasedDirective(const OMPExecutableDirective &S,
2524                                  const RegionCodeGenTy &BodyGen,
2525                                  const TaskGenTy &TaskGen, OMPTaskDataTy &Data);
2526 
2527   void EmitOMPParallelDirective(const OMPParallelDirective &S);
2528   void EmitOMPSimdDirective(const OMPSimdDirective &S);
2529   void EmitOMPForDirective(const OMPForDirective &S);
2530   void EmitOMPForSimdDirective(const OMPForSimdDirective &S);
2531   void EmitOMPSectionsDirective(const OMPSectionsDirective &S);
2532   void EmitOMPSectionDirective(const OMPSectionDirective &S);
2533   void EmitOMPSingleDirective(const OMPSingleDirective &S);
2534   void EmitOMPMasterDirective(const OMPMasterDirective &S);
2535   void EmitOMPCriticalDirective(const OMPCriticalDirective &S);
2536   void EmitOMPParallelForDirective(const OMPParallelForDirective &S);
2537   void EmitOMPParallelForSimdDirective(const OMPParallelForSimdDirective &S);
2538   void EmitOMPParallelSectionsDirective(const OMPParallelSectionsDirective &S);
2539   void EmitOMPTaskDirective(const OMPTaskDirective &S);
2540   void EmitOMPTaskyieldDirective(const OMPTaskyieldDirective &S);
2541   void EmitOMPBarrierDirective(const OMPBarrierDirective &S);
2542   void EmitOMPTaskwaitDirective(const OMPTaskwaitDirective &S);
2543   void EmitOMPTaskgroupDirective(const OMPTaskgroupDirective &S);
2544   void EmitOMPFlushDirective(const OMPFlushDirective &S);
2545   void EmitOMPOrderedDirective(const OMPOrderedDirective &S);
2546   void EmitOMPAtomicDirective(const OMPAtomicDirective &S);
2547   void EmitOMPTargetDirective(const OMPTargetDirective &S);
2548   void EmitOMPTargetDataDirective(const OMPTargetDataDirective &S);
2549   void EmitOMPTargetEnterDataDirective(const OMPTargetEnterDataDirective &S);
2550   void EmitOMPTargetExitDataDirective(const OMPTargetExitDataDirective &S);
2551   void EmitOMPTargetUpdateDirective(const OMPTargetUpdateDirective &S);
2552   void EmitOMPTargetParallelDirective(const OMPTargetParallelDirective &S);
2553   void
2554   EmitOMPTargetParallelForDirective(const OMPTargetParallelForDirective &S);
2555   void EmitOMPTeamsDirective(const OMPTeamsDirective &S);
2556   void
2557   EmitOMPCancellationPointDirective(const OMPCancellationPointDirective &S);
2558   void EmitOMPCancelDirective(const OMPCancelDirective &S);
2559   void EmitOMPTaskLoopBasedDirective(const OMPLoopDirective &S);
2560   void EmitOMPTaskLoopDirective(const OMPTaskLoopDirective &S);
2561   void EmitOMPTaskLoopSimdDirective(const OMPTaskLoopSimdDirective &S);
2562   void EmitOMPDistributeDirective(const OMPDistributeDirective &S);
2563   void EmitOMPDistributeLoop(const OMPDistributeDirective &S);
2564   void EmitOMPDistributeParallelForDirective(
2565       const OMPDistributeParallelForDirective &S);
2566   void EmitOMPDistributeParallelForSimdDirective(
2567       const OMPDistributeParallelForSimdDirective &S);
2568   void EmitOMPDistributeSimdDirective(const OMPDistributeSimdDirective &S);
2569   void EmitOMPTargetParallelForSimdDirective(
2570       const OMPTargetParallelForSimdDirective &S);
2571   void EmitOMPTargetSimdDirective(const OMPTargetSimdDirective &S);
2572   void EmitOMPTeamsDistributeDirective(const OMPTeamsDistributeDirective &S);
2573   void
2574   EmitOMPTeamsDistributeSimdDirective(const OMPTeamsDistributeSimdDirective &S);
2575 
2576   /// Emit outlined function for the target directive.
2577   static std::pair<llvm::Function * /*OutlinedFn*/,
2578                    llvm::Constant * /*OutlinedFnID*/>
2579   EmitOMPTargetDirectiveOutlinedFunction(CodeGenModule &CGM,
2580                                          const OMPTargetDirective &S,
2581                                          StringRef ParentName,
2582                                          bool IsOffloadEntry);
2583   /// \brief Emit inner loop of the worksharing/simd construct.
2584   ///
2585   /// \param S Directive, for which the inner loop must be emitted.
2586   /// \param RequiresCleanup true, if directive has some associated private
2587   /// variables.
2588   /// \param LoopCond Bollean condition for loop continuation.
2589   /// \param IncExpr Increment expression for loop control variable.
2590   /// \param BodyGen Generator for the inner body of the inner loop.
2591   /// \param PostIncGen Genrator for post-increment code (required for ordered
2592   /// loop directvies).
2593   void EmitOMPInnerLoop(
2594       const Stmt &S, bool RequiresCleanup, const Expr *LoopCond,
2595       const Expr *IncExpr,
2596       const llvm::function_ref<void(CodeGenFunction &)> &BodyGen,
2597       const llvm::function_ref<void(CodeGenFunction &)> &PostIncGen);
2598 
2599   JumpDest getOMPCancelDestination(OpenMPDirectiveKind Kind);
2600   /// Emit initial code for loop counters of loop-based directives.
2601   void EmitOMPPrivateLoopCounters(const OMPLoopDirective &S,
2602                                   OMPPrivateScope &LoopScope);
2603 
2604 private:
2605   /// Helpers for the OpenMP loop directives.
2606   void EmitOMPLoopBody(const OMPLoopDirective &D, JumpDest LoopExit);
2607   void EmitOMPSimdInit(const OMPLoopDirective &D, bool IsMonotonic = false);
2608   void EmitOMPSimdFinal(
2609       const OMPLoopDirective &D,
2610       const llvm::function_ref<llvm::Value *(CodeGenFunction &)> &CondGen);
2611   /// \brief Emit code for the worksharing loop-based directive.
2612   /// \return true, if this construct has any lastprivate clause, false -
2613   /// otherwise.
2614   bool EmitOMPWorksharingLoop(const OMPLoopDirective &S);
2615   void EmitOMPOuterLoop(bool IsMonotonic, bool DynamicOrOrdered,
2616       const OMPLoopDirective &S, OMPPrivateScope &LoopScope, bool Ordered,
2617       Address LB, Address UB, Address ST, Address IL, llvm::Value *Chunk);
2618   void EmitOMPForOuterLoop(const OpenMPScheduleTy &ScheduleKind,
2619                            bool IsMonotonic, const OMPLoopDirective &S,
2620                            OMPPrivateScope &LoopScope, bool Ordered, Address LB,
2621                            Address UB, Address ST, Address IL,
2622                            llvm::Value *Chunk);
2623   void EmitOMPDistributeOuterLoop(
2624       OpenMPDistScheduleClauseKind ScheduleKind,
2625       const OMPDistributeDirective &S, OMPPrivateScope &LoopScope,
2626       Address LB, Address UB, Address ST, Address IL, llvm::Value *Chunk);
2627   /// \brief Emit code for sections directive.
2628   void EmitSections(const OMPExecutableDirective &S);
2629 
2630 public:
2631 
2632   //===--------------------------------------------------------------------===//
2633   //                         LValue Expression Emission
2634   //===--------------------------------------------------------------------===//
2635 
2636   /// GetUndefRValue - Get an appropriate 'undef' rvalue for the given type.
2637   RValue GetUndefRValue(QualType Ty);
2638 
2639   /// EmitUnsupportedRValue - Emit a dummy r-value using the type of E
2640   /// and issue an ErrorUnsupported style diagnostic (using the
2641   /// provided Name).
2642   RValue EmitUnsupportedRValue(const Expr *E,
2643                                const char *Name);
2644 
2645   /// EmitUnsupportedLValue - Emit a dummy l-value using the type of E and issue
2646   /// an ErrorUnsupported style diagnostic (using the provided Name).
2647   LValue EmitUnsupportedLValue(const Expr *E,
2648                                const char *Name);
2649 
2650   /// EmitLValue - Emit code to compute a designator that specifies the location
2651   /// of the expression.
2652   ///
2653   /// This can return one of two things: a simple address or a bitfield
2654   /// reference.  In either case, the LLVM Value* in the LValue structure is
2655   /// guaranteed to be an LLVM pointer type.
2656   ///
2657   /// If this returns a bitfield reference, nothing about the pointee type of
2658   /// the LLVM value is known: For example, it may not be a pointer to an
2659   /// integer.
2660   ///
2661   /// If this returns a normal address, and if the lvalue's C type is fixed
2662   /// size, this method guarantees that the returned pointer type will point to
2663   /// an LLVM type of the same size of the lvalue's type.  If the lvalue has a
2664   /// variable length type, this is not possible.
2665   ///
2666   LValue EmitLValue(const Expr *E);
2667 
2668   /// \brief Same as EmitLValue but additionally we generate checking code to
2669   /// guard against undefined behavior.  This is only suitable when we know
2670   /// that the address will be used to access the object.
2671   LValue EmitCheckedLValue(const Expr *E, TypeCheckKind TCK);
2672 
2673   RValue convertTempToRValue(Address addr, QualType type,
2674                              SourceLocation Loc);
2675 
2676   void EmitAtomicInit(Expr *E, LValue lvalue);
2677 
2678   bool LValueIsSuitableForInlineAtomic(LValue Src);
2679 
2680   RValue EmitAtomicLoad(LValue LV, SourceLocation SL,
2681                         AggValueSlot Slot = AggValueSlot::ignored());
2682 
2683   RValue EmitAtomicLoad(LValue lvalue, SourceLocation loc,
2684                         llvm::AtomicOrdering AO, bool IsVolatile = false,
2685                         AggValueSlot slot = AggValueSlot::ignored());
2686 
2687   void EmitAtomicStore(RValue rvalue, LValue lvalue, bool isInit);
2688 
2689   void EmitAtomicStore(RValue rvalue, LValue lvalue, llvm::AtomicOrdering AO,
2690                        bool IsVolatile, bool isInit);
2691 
2692   std::pair<RValue, llvm::Value *> EmitAtomicCompareExchange(
2693       LValue Obj, RValue Expected, RValue Desired, SourceLocation Loc,
2694       llvm::AtomicOrdering Success =
2695           llvm::AtomicOrdering::SequentiallyConsistent,
2696       llvm::AtomicOrdering Failure =
2697           llvm::AtomicOrdering::SequentiallyConsistent,
2698       bool IsWeak = false, AggValueSlot Slot = AggValueSlot::ignored());
2699 
2700   void EmitAtomicUpdate(LValue LVal, llvm::AtomicOrdering AO,
2701                         const llvm::function_ref<RValue(RValue)> &UpdateOp,
2702                         bool IsVolatile);
2703 
2704   /// EmitToMemory - Change a scalar value from its value
2705   /// representation to its in-memory representation.
2706   llvm::Value *EmitToMemory(llvm::Value *Value, QualType Ty);
2707 
2708   /// EmitFromMemory - Change a scalar value from its memory
2709   /// representation to its value representation.
2710   llvm::Value *EmitFromMemory(llvm::Value *Value, QualType Ty);
2711 
2712   /// EmitLoadOfScalar - Load a scalar value from an address, taking
2713   /// care to appropriately convert from the memory representation to
2714   /// the LLVM value representation.
2715   llvm::Value *EmitLoadOfScalar(Address Addr, bool Volatile, QualType Ty,
2716                                 SourceLocation Loc,
2717                                 AlignmentSource AlignSource =
2718                                   AlignmentSource::Type,
2719                                 llvm::MDNode *TBAAInfo = nullptr,
2720                                 QualType TBAABaseTy = QualType(),
2721                                 uint64_t TBAAOffset = 0,
2722                                 bool isNontemporal = false);
2723 
2724   /// EmitLoadOfScalar - Load a scalar value from an address, taking
2725   /// care to appropriately convert from the memory representation to
2726   /// the LLVM value representation.  The l-value must be a simple
2727   /// l-value.
2728   llvm::Value *EmitLoadOfScalar(LValue lvalue, SourceLocation Loc);
2729 
2730   /// EmitStoreOfScalar - Store a scalar value to an address, taking
2731   /// care to appropriately convert from the memory representation to
2732   /// the LLVM value representation.
2733   void EmitStoreOfScalar(llvm::Value *Value, Address Addr,
2734                          bool Volatile, QualType Ty,
2735                          AlignmentSource AlignSource = AlignmentSource::Type,
2736                          llvm::MDNode *TBAAInfo = nullptr, bool isInit = false,
2737                          QualType TBAABaseTy = QualType(),
2738                          uint64_t TBAAOffset = 0, bool isNontemporal = false);
2739 
2740   /// EmitStoreOfScalar - Store a scalar value to an address, taking
2741   /// care to appropriately convert from the memory representation to
2742   /// the LLVM value representation.  The l-value must be a simple
2743   /// l-value.  The isInit flag indicates whether this is an initialization.
2744   /// If so, atomic qualifiers are ignored and the store is always non-atomic.
2745   void EmitStoreOfScalar(llvm::Value *value, LValue lvalue, bool isInit=false);
2746 
2747   /// EmitLoadOfLValue - Given an expression that represents a value lvalue,
2748   /// this method emits the address of the lvalue, then loads the result as an
2749   /// rvalue, returning the rvalue.
2750   RValue EmitLoadOfLValue(LValue V, SourceLocation Loc);
2751   RValue EmitLoadOfExtVectorElementLValue(LValue V);
2752   RValue EmitLoadOfBitfieldLValue(LValue LV);
2753   RValue EmitLoadOfGlobalRegLValue(LValue LV);
2754 
2755   /// EmitStoreThroughLValue - Store the specified rvalue into the specified
2756   /// lvalue, where both are guaranteed to the have the same type, and that type
2757   /// is 'Ty'.
2758   void EmitStoreThroughLValue(RValue Src, LValue Dst, bool isInit = false);
2759   void EmitStoreThroughExtVectorComponentLValue(RValue Src, LValue Dst);
2760   void EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst);
2761 
2762   /// EmitStoreThroughBitfieldLValue - Store Src into Dst with same constraints
2763   /// as EmitStoreThroughLValue.
2764   ///
2765   /// \param Result [out] - If non-null, this will be set to a Value* for the
2766   /// bit-field contents after the store, appropriate for use as the result of
2767   /// an assignment to the bit-field.
2768   void EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
2769                                       llvm::Value **Result=nullptr);
2770 
2771   /// Emit an l-value for an assignment (simple or compound) of complex type.
2772   LValue EmitComplexAssignmentLValue(const BinaryOperator *E);
2773   LValue EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E);
2774   LValue EmitScalarCompoundAssignWithComplex(const CompoundAssignOperator *E,
2775                                              llvm::Value *&Result);
2776 
2777   // Note: only available for agg return types
2778   LValue EmitBinaryOperatorLValue(const BinaryOperator *E);
2779   LValue EmitCompoundAssignmentLValue(const CompoundAssignOperator *E);
2780   // Note: only available for agg return types
2781   LValue EmitCallExprLValue(const CallExpr *E);
2782   // Note: only available for agg return types
2783   LValue EmitVAArgExprLValue(const VAArgExpr *E);
2784   LValue EmitDeclRefLValue(const DeclRefExpr *E);
2785   LValue EmitStringLiteralLValue(const StringLiteral *E);
2786   LValue EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E);
2787   LValue EmitPredefinedLValue(const PredefinedExpr *E);
2788   LValue EmitUnaryOpLValue(const UnaryOperator *E);
2789   LValue EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
2790                                 bool Accessed = false);
2791   LValue EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
2792                                  bool IsLowerBound = true);
2793   LValue EmitExtVectorElementExpr(const ExtVectorElementExpr *E);
2794   LValue EmitMemberExpr(const MemberExpr *E);
2795   LValue EmitObjCIsaExpr(const ObjCIsaExpr *E);
2796   LValue EmitCompoundLiteralLValue(const CompoundLiteralExpr *E);
2797   LValue EmitInitListLValue(const InitListExpr *E);
2798   LValue EmitConditionalOperatorLValue(const AbstractConditionalOperator *E);
2799   LValue EmitCastLValue(const CastExpr *E);
2800   LValue EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E);
2801   LValue EmitOpaqueValueLValue(const OpaqueValueExpr *e);
2802 
2803   Address EmitExtVectorElementLValue(LValue V);
2804 
2805   RValue EmitRValueForField(LValue LV, const FieldDecl *FD, SourceLocation Loc);
2806 
2807   Address EmitArrayToPointerDecay(const Expr *Array,
2808                                   AlignmentSource *AlignSource = nullptr);
2809 
2810   class ConstantEmission {
2811     llvm::PointerIntPair<llvm::Constant*, 1, bool> ValueAndIsReference;
2812     ConstantEmission(llvm::Constant *C, bool isReference)
2813       : ValueAndIsReference(C, isReference) {}
2814   public:
2815     ConstantEmission() {}
2816     static ConstantEmission forReference(llvm::Constant *C) {
2817       return ConstantEmission(C, true);
2818     }
2819     static ConstantEmission forValue(llvm::Constant *C) {
2820       return ConstantEmission(C, false);
2821     }
2822 
2823     explicit operator bool() const {
2824       return ValueAndIsReference.getOpaqueValue() != nullptr;
2825     }
2826 
2827     bool isReference() const { return ValueAndIsReference.getInt(); }
2828     LValue getReferenceLValue(CodeGenFunction &CGF, Expr *refExpr) const {
2829       assert(isReference());
2830       return CGF.MakeNaturalAlignAddrLValue(ValueAndIsReference.getPointer(),
2831                                             refExpr->getType());
2832     }
2833 
2834     llvm::Constant *getValue() const {
2835       assert(!isReference());
2836       return ValueAndIsReference.getPointer();
2837     }
2838   };
2839 
2840   ConstantEmission tryEmitAsConstant(DeclRefExpr *refExpr);
2841 
2842   RValue EmitPseudoObjectRValue(const PseudoObjectExpr *e,
2843                                 AggValueSlot slot = AggValueSlot::ignored());
2844   LValue EmitPseudoObjectLValue(const PseudoObjectExpr *e);
2845 
2846   llvm::Value *EmitIvarOffset(const ObjCInterfaceDecl *Interface,
2847                               const ObjCIvarDecl *Ivar);
2848   LValue EmitLValueForField(LValue Base, const FieldDecl* Field);
2849   LValue EmitLValueForLambdaField(const FieldDecl *Field);
2850 
2851   /// EmitLValueForFieldInitialization - Like EmitLValueForField, except that
2852   /// if the Field is a reference, this will return the address of the reference
2853   /// and not the address of the value stored in the reference.
2854   LValue EmitLValueForFieldInitialization(LValue Base,
2855                                           const FieldDecl* Field);
2856 
2857   LValue EmitLValueForIvar(QualType ObjectTy,
2858                            llvm::Value* Base, const ObjCIvarDecl *Ivar,
2859                            unsigned CVRQualifiers);
2860 
2861   LValue EmitCXXConstructLValue(const CXXConstructExpr *E);
2862   LValue EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E);
2863   LValue EmitLambdaLValue(const LambdaExpr *E);
2864   LValue EmitCXXTypeidLValue(const CXXTypeidExpr *E);
2865   LValue EmitCXXUuidofLValue(const CXXUuidofExpr *E);
2866 
2867   LValue EmitObjCMessageExprLValue(const ObjCMessageExpr *E);
2868   LValue EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E);
2869   LValue EmitStmtExprLValue(const StmtExpr *E);
2870   LValue EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E);
2871   LValue EmitObjCSelectorLValue(const ObjCSelectorExpr *E);
2872   void   EmitDeclRefExprDbgValue(const DeclRefExpr *E, const APValue &Init);
2873 
2874   //===--------------------------------------------------------------------===//
2875   //                         Scalar Expression Emission
2876   //===--------------------------------------------------------------------===//
2877 
2878   /// EmitCall - Generate a call of the given function, expecting the given
2879   /// result type, and using the given argument list which specifies both the
2880   /// LLVM arguments and the types they were derived from.
2881   RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee,
2882                   ReturnValueSlot ReturnValue, const CallArgList &Args,
2883                   llvm::Instruction **callOrInvoke = nullptr);
2884 
2885   RValue EmitCall(QualType FnType, const CGCallee &Callee, const CallExpr *E,
2886                   ReturnValueSlot ReturnValue,
2887                   llvm::Value *Chain = nullptr);
2888   RValue EmitCallExpr(const CallExpr *E,
2889                       ReturnValueSlot ReturnValue = ReturnValueSlot());
2890   RValue EmitSimpleCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue);
2891   CGCallee EmitCallee(const Expr *E);
2892 
2893   void checkTargetFeatures(const CallExpr *E, const FunctionDecl *TargetDecl);
2894 
2895   llvm::CallInst *EmitRuntimeCall(llvm::Value *callee,
2896                                   const Twine &name = "");
2897   llvm::CallInst *EmitRuntimeCall(llvm::Value *callee,
2898                                   ArrayRef<llvm::Value*> args,
2899                                   const Twine &name = "");
2900   llvm::CallInst *EmitNounwindRuntimeCall(llvm::Value *callee,
2901                                           const Twine &name = "");
2902   llvm::CallInst *EmitNounwindRuntimeCall(llvm::Value *callee,
2903                                           ArrayRef<llvm::Value*> args,
2904                                           const Twine &name = "");
2905 
2906   llvm::CallSite EmitCallOrInvoke(llvm::Value *Callee,
2907                                   ArrayRef<llvm::Value *> Args,
2908                                   const Twine &Name = "");
2909   llvm::CallSite EmitRuntimeCallOrInvoke(llvm::Value *callee,
2910                                          ArrayRef<llvm::Value*> args,
2911                                          const Twine &name = "");
2912   llvm::CallSite EmitRuntimeCallOrInvoke(llvm::Value *callee,
2913                                          const Twine &name = "");
2914   void EmitNoreturnRuntimeCallOrInvoke(llvm::Value *callee,
2915                                        ArrayRef<llvm::Value*> args);
2916 
2917   CGCallee BuildAppleKextVirtualCall(const CXXMethodDecl *MD,
2918                                      NestedNameSpecifier *Qual,
2919                                      llvm::Type *Ty);
2920 
2921   CGCallee BuildAppleKextVirtualDestructorCall(const CXXDestructorDecl *DD,
2922                                                CXXDtorType Type,
2923                                                const CXXRecordDecl *RD);
2924 
2925   RValue
2926   EmitCXXMemberOrOperatorCall(const CXXMethodDecl *Method,
2927                               const CGCallee &Callee,
2928                               ReturnValueSlot ReturnValue, llvm::Value *This,
2929                               llvm::Value *ImplicitParam,
2930                               QualType ImplicitParamTy, const CallExpr *E,
2931                               CallArgList *RtlArgs);
2932   RValue EmitCXXDestructorCall(const CXXDestructorDecl *DD,
2933                                const CGCallee &Callee,
2934                                llvm::Value *This, llvm::Value *ImplicitParam,
2935                                QualType ImplicitParamTy, const CallExpr *E,
2936                                StructorType Type);
2937   RValue EmitCXXMemberCallExpr(const CXXMemberCallExpr *E,
2938                                ReturnValueSlot ReturnValue);
2939   RValue EmitCXXMemberOrOperatorMemberCallExpr(const CallExpr *CE,
2940                                                const CXXMethodDecl *MD,
2941                                                ReturnValueSlot ReturnValue,
2942                                                bool HasQualifier,
2943                                                NestedNameSpecifier *Qualifier,
2944                                                bool IsArrow, const Expr *Base);
2945   // Compute the object pointer.
2946   Address EmitCXXMemberDataPointerAddress(const Expr *E, Address base,
2947                                           llvm::Value *memberPtr,
2948                                           const MemberPointerType *memberPtrType,
2949                                           AlignmentSource *AlignSource = nullptr);
2950   RValue EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
2951                                       ReturnValueSlot ReturnValue);
2952 
2953   RValue EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E,
2954                                        const CXXMethodDecl *MD,
2955                                        ReturnValueSlot ReturnValue);
2956   RValue EmitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E);
2957 
2958   RValue EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E,
2959                                 ReturnValueSlot ReturnValue);
2960 
2961   RValue EmitCUDADevicePrintfCallExpr(const CallExpr *E,
2962                                       ReturnValueSlot ReturnValue);
2963 
2964   RValue EmitBuiltinExpr(const FunctionDecl *FD,
2965                          unsigned BuiltinID, const CallExpr *E,
2966                          ReturnValueSlot ReturnValue);
2967 
2968   RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue);
2969 
2970   /// EmitTargetBuiltinExpr - Emit the given builtin call. Returns 0 if the call
2971   /// is unhandled by the current target.
2972   llvm::Value *EmitTargetBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
2973 
2974   llvm::Value *EmitAArch64CompareBuiltinExpr(llvm::Value *Op, llvm::Type *Ty,
2975                                              const llvm::CmpInst::Predicate Fp,
2976                                              const llvm::CmpInst::Predicate Ip,
2977                                              const llvm::Twine &Name = "");
2978   llvm::Value *EmitARMBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
2979 
2980   llvm::Value *EmitCommonNeonBuiltinExpr(unsigned BuiltinID,
2981                                          unsigned LLVMIntrinsic,
2982                                          unsigned AltLLVMIntrinsic,
2983                                          const char *NameHint,
2984                                          unsigned Modifier,
2985                                          const CallExpr *E,
2986                                          SmallVectorImpl<llvm::Value *> &Ops,
2987                                          Address PtrOp0, Address PtrOp1);
2988   llvm::Function *LookupNeonLLVMIntrinsic(unsigned IntrinsicID,
2989                                           unsigned Modifier, llvm::Type *ArgTy,
2990                                           const CallExpr *E);
2991   llvm::Value *EmitNeonCall(llvm::Function *F,
2992                             SmallVectorImpl<llvm::Value*> &O,
2993                             const char *name,
2994                             unsigned shift = 0, bool rightshift = false);
2995   llvm::Value *EmitNeonSplat(llvm::Value *V, llvm::Constant *Idx);
2996   llvm::Value *EmitNeonShiftVector(llvm::Value *V, llvm::Type *Ty,
2997                                    bool negateForRightShift);
2998   llvm::Value *EmitNeonRShiftImm(llvm::Value *Vec, llvm::Value *Amt,
2999                                  llvm::Type *Ty, bool usgn, const char *name);
3000   llvm::Value *vectorWrapScalar16(llvm::Value *Op);
3001   llvm::Value *EmitAArch64BuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3002 
3003   llvm::Value *BuildVector(ArrayRef<llvm::Value*> Ops);
3004   llvm::Value *EmitX86BuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3005   llvm::Value *EmitPPCBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3006   llvm::Value *EmitAMDGPUBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3007   llvm::Value *EmitSystemZBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3008   llvm::Value *EmitNVPTXBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3009   llvm::Value *EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
3010                                           const CallExpr *E);
3011 
3012 private:
3013   enum class MSVCIntrin;
3014 
3015 public:
3016   llvm::Value *EmitMSVCBuiltinExpr(MSVCIntrin BuiltinID, const CallExpr *E);
3017 
3018   llvm::Value *EmitObjCProtocolExpr(const ObjCProtocolExpr *E);
3019   llvm::Value *EmitObjCStringLiteral(const ObjCStringLiteral *E);
3020   llvm::Value *EmitObjCBoxedExpr(const ObjCBoxedExpr *E);
3021   llvm::Value *EmitObjCArrayLiteral(const ObjCArrayLiteral *E);
3022   llvm::Value *EmitObjCDictionaryLiteral(const ObjCDictionaryLiteral *E);
3023   llvm::Value *EmitObjCCollectionLiteral(const Expr *E,
3024                                 const ObjCMethodDecl *MethodWithObjects);
3025   llvm::Value *EmitObjCSelectorExpr(const ObjCSelectorExpr *E);
3026   RValue EmitObjCMessageExpr(const ObjCMessageExpr *E,
3027                              ReturnValueSlot Return = ReturnValueSlot());
3028 
3029   /// Retrieves the default cleanup kind for an ARC cleanup.
3030   /// Except under -fobjc-arc-eh, ARC cleanups are normal-only.
3031   CleanupKind getARCCleanupKind() {
3032     return CGM.getCodeGenOpts().ObjCAutoRefCountExceptions
3033              ? NormalAndEHCleanup : NormalCleanup;
3034   }
3035 
3036   // ARC primitives.
3037   void EmitARCInitWeak(Address addr, llvm::Value *value);
3038   void EmitARCDestroyWeak(Address addr);
3039   llvm::Value *EmitARCLoadWeak(Address addr);
3040   llvm::Value *EmitARCLoadWeakRetained(Address addr);
3041   llvm::Value *EmitARCStoreWeak(Address addr, llvm::Value *value, bool ignored);
3042   void EmitARCCopyWeak(Address dst, Address src);
3043   void EmitARCMoveWeak(Address dst, Address src);
3044   llvm::Value *EmitARCRetainAutorelease(QualType type, llvm::Value *value);
3045   llvm::Value *EmitARCRetainAutoreleaseNonBlock(llvm::Value *value);
3046   llvm::Value *EmitARCStoreStrong(LValue lvalue, llvm::Value *value,
3047                                   bool resultIgnored);
3048   llvm::Value *EmitARCStoreStrongCall(Address addr, llvm::Value *value,
3049                                       bool resultIgnored);
3050   llvm::Value *EmitARCRetain(QualType type, llvm::Value *value);
3051   llvm::Value *EmitARCRetainNonBlock(llvm::Value *value);
3052   llvm::Value *EmitARCRetainBlock(llvm::Value *value, bool mandatory);
3053   void EmitARCDestroyStrong(Address addr, ARCPreciseLifetime_t precise);
3054   void EmitARCRelease(llvm::Value *value, ARCPreciseLifetime_t precise);
3055   llvm::Value *EmitARCAutorelease(llvm::Value *value);
3056   llvm::Value *EmitARCAutoreleaseReturnValue(llvm::Value *value);
3057   llvm::Value *EmitARCRetainAutoreleaseReturnValue(llvm::Value *value);
3058   llvm::Value *EmitARCRetainAutoreleasedReturnValue(llvm::Value *value);
3059   llvm::Value *EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value *value);
3060 
3061   std::pair<LValue,llvm::Value*>
3062   EmitARCStoreAutoreleasing(const BinaryOperator *e);
3063   std::pair<LValue,llvm::Value*>
3064   EmitARCStoreStrong(const BinaryOperator *e, bool ignored);
3065   std::pair<LValue,llvm::Value*>
3066   EmitARCStoreUnsafeUnretained(const BinaryOperator *e, bool ignored);
3067 
3068   llvm::Value *EmitObjCThrowOperand(const Expr *expr);
3069   llvm::Value *EmitObjCConsumeObject(QualType T, llvm::Value *Ptr);
3070   llvm::Value *EmitObjCExtendObjectLifetime(QualType T, llvm::Value *Ptr);
3071 
3072   llvm::Value *EmitARCExtendBlockObject(const Expr *expr);
3073   llvm::Value *EmitARCReclaimReturnedObject(const Expr *e,
3074                                             bool allowUnsafeClaim);
3075   llvm::Value *EmitARCRetainScalarExpr(const Expr *expr);
3076   llvm::Value *EmitARCRetainAutoreleaseScalarExpr(const Expr *expr);
3077   llvm::Value *EmitARCUnsafeUnretainedScalarExpr(const Expr *expr);
3078 
3079   void EmitARCIntrinsicUse(ArrayRef<llvm::Value*> values);
3080 
3081   static Destroyer destroyARCStrongImprecise;
3082   static Destroyer destroyARCStrongPrecise;
3083   static Destroyer destroyARCWeak;
3084 
3085   void EmitObjCAutoreleasePoolPop(llvm::Value *Ptr);
3086   llvm::Value *EmitObjCAutoreleasePoolPush();
3087   llvm::Value *EmitObjCMRRAutoreleasePoolPush();
3088   void EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr);
3089   void EmitObjCMRRAutoreleasePoolPop(llvm::Value *Ptr);
3090 
3091   /// \brief Emits a reference binding to the passed in expression.
3092   RValue EmitReferenceBindingToExpr(const Expr *E);
3093 
3094   //===--------------------------------------------------------------------===//
3095   //                           Expression Emission
3096   //===--------------------------------------------------------------------===//
3097 
3098   // Expressions are broken into three classes: scalar, complex, aggregate.
3099 
3100   /// EmitScalarExpr - Emit the computation of the specified expression of LLVM
3101   /// scalar type, returning the result.
3102   llvm::Value *EmitScalarExpr(const Expr *E , bool IgnoreResultAssign = false);
3103 
3104   /// Emit a conversion from the specified type to the specified destination
3105   /// type, both of which are LLVM scalar types.
3106   llvm::Value *EmitScalarConversion(llvm::Value *Src, QualType SrcTy,
3107                                     QualType DstTy, SourceLocation Loc);
3108 
3109   /// Emit a conversion from the specified complex type to the specified
3110   /// destination type, where the destination type is an LLVM scalar type.
3111   llvm::Value *EmitComplexToScalarConversion(ComplexPairTy Src, QualType SrcTy,
3112                                              QualType DstTy,
3113                                              SourceLocation Loc);
3114 
3115   /// EmitAggExpr - Emit the computation of the specified expression
3116   /// of aggregate type.  The result is computed into the given slot,
3117   /// which may be null to indicate that the value is not needed.
3118   void EmitAggExpr(const Expr *E, AggValueSlot AS);
3119 
3120   /// EmitAggExprToLValue - Emit the computation of the specified expression of
3121   /// aggregate type into a temporary LValue.
3122   LValue EmitAggExprToLValue(const Expr *E);
3123 
3124   /// EmitExtendGCLifetime - Given a pointer to an Objective-C object,
3125   /// make sure it survives garbage collection until this point.
3126   void EmitExtendGCLifetime(llvm::Value *object);
3127 
3128   /// EmitComplexExpr - Emit the computation of the specified expression of
3129   /// complex type, returning the result.
3130   ComplexPairTy EmitComplexExpr(const Expr *E,
3131                                 bool IgnoreReal = false,
3132                                 bool IgnoreImag = false);
3133 
3134   /// EmitComplexExprIntoLValue - Emit the given expression of complex
3135   /// type and place its result into the specified l-value.
3136   void EmitComplexExprIntoLValue(const Expr *E, LValue dest, bool isInit);
3137 
3138   /// EmitStoreOfComplex - Store a complex number into the specified l-value.
3139   void EmitStoreOfComplex(ComplexPairTy V, LValue dest, bool isInit);
3140 
3141   /// EmitLoadOfComplex - Load a complex number from the specified l-value.
3142   ComplexPairTy EmitLoadOfComplex(LValue src, SourceLocation loc);
3143 
3144   Address emitAddrOfRealComponent(Address complex, QualType complexType);
3145   Address emitAddrOfImagComponent(Address complex, QualType complexType);
3146 
3147   /// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
3148   /// global variable that has already been created for it.  If the initializer
3149   /// has a different type than GV does, this may free GV and return a different
3150   /// one.  Otherwise it just returns GV.
3151   llvm::GlobalVariable *
3152   AddInitializerToStaticVarDecl(const VarDecl &D,
3153                                 llvm::GlobalVariable *GV);
3154 
3155 
3156   /// EmitCXXGlobalVarDeclInit - Create the initializer for a C++
3157   /// variable with global storage.
3158   void EmitCXXGlobalVarDeclInit(const VarDecl &D, llvm::Constant *DeclPtr,
3159                                 bool PerformInit);
3160 
3161   llvm::Constant *createAtExitStub(const VarDecl &VD, llvm::Constant *Dtor,
3162                                    llvm::Constant *Addr);
3163 
3164   /// Call atexit() with a function that passes the given argument to
3165   /// the given function.
3166   void registerGlobalDtorWithAtExit(const VarDecl &D, llvm::Constant *fn,
3167                                     llvm::Constant *addr);
3168 
3169   /// Emit code in this function to perform a guarded variable
3170   /// initialization.  Guarded initializations are used when it's not
3171   /// possible to prove that an initialization will be done exactly
3172   /// once, e.g. with a static local variable or a static data member
3173   /// of a class template.
3174   void EmitCXXGuardedInit(const VarDecl &D, llvm::GlobalVariable *DeclPtr,
3175                           bool PerformInit);
3176 
3177   /// GenerateCXXGlobalInitFunc - Generates code for initializing global
3178   /// variables.
3179   void GenerateCXXGlobalInitFunc(llvm::Function *Fn,
3180                                  ArrayRef<llvm::Function *> CXXThreadLocals,
3181                                  Address Guard = Address::invalid());
3182 
3183   /// GenerateCXXGlobalDtorsFunc - Generates code for destroying global
3184   /// variables.
3185   void GenerateCXXGlobalDtorsFunc(llvm::Function *Fn,
3186                                   const std::vector<std::pair<llvm::WeakVH,
3187                                   llvm::Constant*> > &DtorsAndObjects);
3188 
3189   void GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn,
3190                                         const VarDecl *D,
3191                                         llvm::GlobalVariable *Addr,
3192                                         bool PerformInit);
3193 
3194   void EmitCXXConstructExpr(const CXXConstructExpr *E, AggValueSlot Dest);
3195 
3196   void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp);
3197 
3198   void enterFullExpression(const ExprWithCleanups *E) {
3199     if (E->getNumObjects() == 0) return;
3200     enterNonTrivialFullExpression(E);
3201   }
3202   void enterNonTrivialFullExpression(const ExprWithCleanups *E);
3203 
3204   void EmitCXXThrowExpr(const CXXThrowExpr *E, bool KeepInsertionPoint = true);
3205 
3206   void EmitLambdaExpr(const LambdaExpr *E, AggValueSlot Dest);
3207 
3208   RValue EmitAtomicExpr(AtomicExpr *E);
3209 
3210   //===--------------------------------------------------------------------===//
3211   //                         Annotations Emission
3212   //===--------------------------------------------------------------------===//
3213 
3214   /// Emit an annotation call (intrinsic or builtin).
3215   llvm::Value *EmitAnnotationCall(llvm::Value *AnnotationFn,
3216                                   llvm::Value *AnnotatedVal,
3217                                   StringRef AnnotationStr,
3218                                   SourceLocation Location);
3219 
3220   /// Emit local annotations for the local variable V, declared by D.
3221   void EmitVarAnnotations(const VarDecl *D, llvm::Value *V);
3222 
3223   /// Emit field annotations for the given field & value. Returns the
3224   /// annotation result.
3225   Address EmitFieldAnnotations(const FieldDecl *D, Address V);
3226 
3227   //===--------------------------------------------------------------------===//
3228   //                             Internal Helpers
3229   //===--------------------------------------------------------------------===//
3230 
3231   /// ContainsLabel - Return true if the statement contains a label in it.  If
3232   /// this statement is not executed normally, it not containing a label means
3233   /// that we can just remove the code.
3234   static bool ContainsLabel(const Stmt *S, bool IgnoreCaseStmts = false);
3235 
3236   /// containsBreak - Return true if the statement contains a break out of it.
3237   /// If the statement (recursively) contains a switch or loop with a break
3238   /// inside of it, this is fine.
3239   static bool containsBreak(const Stmt *S);
3240 
3241   /// Determine if the given statement might introduce a declaration into the
3242   /// current scope, by being a (possibly-labelled) DeclStmt.
3243   static bool mightAddDeclToScope(const Stmt *S);
3244 
3245   /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
3246   /// to a constant, or if it does but contains a label, return false.  If it
3247   /// constant folds return true and set the boolean result in Result.
3248   bool ConstantFoldsToSimpleInteger(const Expr *Cond, bool &Result,
3249                                     bool AllowLabels = false);
3250 
3251   /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
3252   /// to a constant, or if it does but contains a label, return false.  If it
3253   /// constant folds return true and set the folded value.
3254   bool ConstantFoldsToSimpleInteger(const Expr *Cond, llvm::APSInt &Result,
3255                                     bool AllowLabels = false);
3256 
3257   /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an
3258   /// if statement) to the specified blocks.  Based on the condition, this might
3259   /// try to simplify the codegen of the conditional based on the branch.
3260   /// TrueCount should be the number of times we expect the condition to
3261   /// evaluate to true based on PGO data.
3262   void EmitBranchOnBoolExpr(const Expr *Cond, llvm::BasicBlock *TrueBlock,
3263                             llvm::BasicBlock *FalseBlock, uint64_t TrueCount);
3264 
3265   /// \brief Emit a description of a type in a format suitable for passing to
3266   /// a runtime sanitizer handler.
3267   llvm::Constant *EmitCheckTypeDescriptor(QualType T);
3268 
3269   /// \brief Convert a value into a format suitable for passing to a runtime
3270   /// sanitizer handler.
3271   llvm::Value *EmitCheckValue(llvm::Value *V);
3272 
3273   /// \brief Emit a description of a source location in a format suitable for
3274   /// passing to a runtime sanitizer handler.
3275   llvm::Constant *EmitCheckSourceLocation(SourceLocation Loc);
3276 
3277   /// \brief Create a basic block that will call a handler function in a
3278   /// sanitizer runtime with the provided arguments, and create a conditional
3279   /// branch to it.
3280   void EmitCheck(ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
3281                  StringRef CheckName, ArrayRef<llvm::Constant *> StaticArgs,
3282                  ArrayRef<llvm::Value *> DynamicArgs);
3283 
3284   /// \brief Emit a slow path cross-DSO CFI check which calls __cfi_slowpath
3285   /// if Cond if false.
3286   void EmitCfiSlowPathCheck(SanitizerMask Kind, llvm::Value *Cond,
3287                             llvm::ConstantInt *TypeId, llvm::Value *Ptr,
3288                             ArrayRef<llvm::Constant *> StaticArgs);
3289 
3290   /// \brief Create a basic block that will call the trap intrinsic, and emit a
3291   /// conditional branch to it, for the -ftrapv checks.
3292   void EmitTrapCheck(llvm::Value *Checked);
3293 
3294   /// \brief Emit a call to trap or debugtrap and attach function attribute
3295   /// "trap-func-name" if specified.
3296   llvm::CallInst *EmitTrapCall(llvm::Intrinsic::ID IntrID);
3297 
3298   /// \brief Emit a cross-DSO CFI failure handling function.
3299   void EmitCfiCheckFail();
3300 
3301   /// \brief Create a check for a function parameter that may potentially be
3302   /// declared as non-null.
3303   void EmitNonNullArgCheck(RValue RV, QualType ArgType, SourceLocation ArgLoc,
3304                            const FunctionDecl *FD, unsigned ParmNum);
3305 
3306   /// EmitCallArg - Emit a single call argument.
3307   void EmitCallArg(CallArgList &args, const Expr *E, QualType ArgType);
3308 
3309   /// EmitDelegateCallArg - We are performing a delegate call; that
3310   /// is, the current function is delegating to another one.  Produce
3311   /// a r-value suitable for passing the given parameter.
3312   void EmitDelegateCallArg(CallArgList &args, const VarDecl *param,
3313                            SourceLocation loc);
3314 
3315   /// SetFPAccuracy - Set the minimum required accuracy of the given floating
3316   /// point operation, expressed as the maximum relative error in ulp.
3317   void SetFPAccuracy(llvm::Value *Val, float Accuracy);
3318 
3319 private:
3320   llvm::MDNode *getRangeForLoadFromType(QualType Ty);
3321   void EmitReturnOfRValue(RValue RV, QualType Ty);
3322 
3323   void deferPlaceholderReplacement(llvm::Instruction *Old, llvm::Value *New);
3324 
3325   llvm::SmallVector<std::pair<llvm::Instruction *, llvm::Value *>, 4>
3326   DeferredReplacements;
3327 
3328   /// Set the address of a local variable.
3329   void setAddrOfLocalVar(const VarDecl *VD, Address Addr) {
3330     assert(!LocalDeclMap.count(VD) && "Decl already exists in LocalDeclMap!");
3331     LocalDeclMap.insert({VD, Addr});
3332   }
3333 
3334   /// ExpandTypeFromArgs - Reconstruct a structure of type \arg Ty
3335   /// from function arguments into \arg Dst. See ABIArgInfo::Expand.
3336   ///
3337   /// \param AI - The first function argument of the expansion.
3338   void ExpandTypeFromArgs(QualType Ty, LValue Dst,
3339                           SmallVectorImpl<llvm::Value *>::iterator &AI);
3340 
3341   /// ExpandTypeToArgs - Expand an RValue \arg RV, with the LLVM type for \arg
3342   /// Ty, into individual arguments on the provided vector \arg IRCallArgs,
3343   /// starting at index \arg IRCallArgPos. See ABIArgInfo::Expand.
3344   void ExpandTypeToArgs(QualType Ty, RValue RV, llvm::FunctionType *IRFuncTy,
3345                         SmallVectorImpl<llvm::Value *> &IRCallArgs,
3346                         unsigned &IRCallArgPos);
3347 
3348   llvm::Value* EmitAsmInput(const TargetInfo::ConstraintInfo &Info,
3349                             const Expr *InputExpr, std::string &ConstraintStr);
3350 
3351   llvm::Value* EmitAsmInputLValue(const TargetInfo::ConstraintInfo &Info,
3352                                   LValue InputValue, QualType InputType,
3353                                   std::string &ConstraintStr,
3354                                   SourceLocation Loc);
3355 
3356   /// \brief Attempts to statically evaluate the object size of E. If that
3357   /// fails, emits code to figure the size of E out for us. This is
3358   /// pass_object_size aware.
3359   llvm::Value *evaluateOrEmitBuiltinObjectSize(const Expr *E, unsigned Type,
3360                                                llvm::IntegerType *ResType);
3361 
3362   /// \brief Emits the size of E, as required by __builtin_object_size. This
3363   /// function is aware of pass_object_size parameters, and will act accordingly
3364   /// if E is a parameter with the pass_object_size attribute.
3365   llvm::Value *emitBuiltinObjectSize(const Expr *E, unsigned Type,
3366                                      llvm::IntegerType *ResType);
3367 
3368 public:
3369 #ifndef NDEBUG
3370   // Determine whether the given argument is an Objective-C method
3371   // that may have type parameters in its signature.
3372   static bool isObjCMethodWithTypeParams(const ObjCMethodDecl *method) {
3373     const DeclContext *dc = method->getDeclContext();
3374     if (const ObjCInterfaceDecl *classDecl= dyn_cast<ObjCInterfaceDecl>(dc)) {
3375       return classDecl->getTypeParamListAsWritten();
3376     }
3377 
3378     if (const ObjCCategoryDecl *catDecl = dyn_cast<ObjCCategoryDecl>(dc)) {
3379       return catDecl->getTypeParamList();
3380     }
3381 
3382     return false;
3383   }
3384 
3385   template<typename T>
3386   static bool isObjCMethodWithTypeParams(const T *) { return false; }
3387 #endif
3388 
3389   enum class EvaluationOrder {
3390     ///! No language constraints on evaluation order.
3391     Default,
3392     ///! Language semantics require left-to-right evaluation.
3393     ForceLeftToRight,
3394     ///! Language semantics require right-to-left evaluation.
3395     ForceRightToLeft
3396   };
3397 
3398   /// EmitCallArgs - Emit call arguments for a function.
3399   template <typename T>
3400   void EmitCallArgs(CallArgList &Args, const T *CallArgTypeInfo,
3401                     llvm::iterator_range<CallExpr::const_arg_iterator> ArgRange,
3402                     const FunctionDecl *CalleeDecl = nullptr,
3403                     unsigned ParamsToSkip = 0,
3404                     EvaluationOrder Order = EvaluationOrder::Default) {
3405     SmallVector<QualType, 16> ArgTypes;
3406     CallExpr::const_arg_iterator Arg = ArgRange.begin();
3407 
3408     assert((ParamsToSkip == 0 || CallArgTypeInfo) &&
3409            "Can't skip parameters if type info is not provided");
3410     if (CallArgTypeInfo) {
3411 #ifndef NDEBUG
3412       bool isGenericMethod = isObjCMethodWithTypeParams(CallArgTypeInfo);
3413 #endif
3414 
3415       // First, use the argument types that the type info knows about
3416       for (auto I = CallArgTypeInfo->param_type_begin() + ParamsToSkip,
3417                 E = CallArgTypeInfo->param_type_end();
3418            I != E; ++I, ++Arg) {
3419         assert(Arg != ArgRange.end() && "Running over edge of argument list!");
3420         assert((isGenericMethod ||
3421                 ((*I)->isVariablyModifiedType() ||
3422                  (*I).getNonReferenceType()->isObjCRetainableType() ||
3423                  getContext()
3424                          .getCanonicalType((*I).getNonReferenceType())
3425                          .getTypePtr() ==
3426                      getContext()
3427                          .getCanonicalType((*Arg)->getType())
3428                          .getTypePtr())) &&
3429                "type mismatch in call argument!");
3430         ArgTypes.push_back(*I);
3431       }
3432     }
3433 
3434     // Either we've emitted all the call args, or we have a call to variadic
3435     // function.
3436     assert((Arg == ArgRange.end() || !CallArgTypeInfo ||
3437             CallArgTypeInfo->isVariadic()) &&
3438            "Extra arguments in non-variadic function!");
3439 
3440     // If we still have any arguments, emit them using the type of the argument.
3441     for (auto *A : llvm::make_range(Arg, ArgRange.end()))
3442       ArgTypes.push_back(getVarArgType(A));
3443 
3444     EmitCallArgs(Args, ArgTypes, ArgRange, CalleeDecl, ParamsToSkip, Order);
3445   }
3446 
3447   void EmitCallArgs(CallArgList &Args, ArrayRef<QualType> ArgTypes,
3448                     llvm::iterator_range<CallExpr::const_arg_iterator> ArgRange,
3449                     const FunctionDecl *CalleeDecl = nullptr,
3450                     unsigned ParamsToSkip = 0,
3451                     EvaluationOrder Order = EvaluationOrder::Default);
3452 
3453   /// EmitPointerWithAlignment - Given an expression with a pointer
3454   /// type, emit the value and compute our best estimate of the
3455   /// alignment of the pointee.
3456   ///
3457   /// Note that this function will conservatively fall back on the type
3458   /// when it doesn't
3459   ///
3460   /// \param Source - If non-null, this will be initialized with
3461   ///   information about the source of the alignment.  Note that this
3462   ///   function will conservatively fall back on the type when it
3463   ///   doesn't recognize the expression, which means that sometimes
3464   ///
3465   ///   a worst-case One
3466   ///   reasonable way to use this information is when there's a
3467   ///   language guarantee that the pointer must be aligned to some
3468   ///   stricter value, and we're simply trying to ensure that
3469   ///   sufficiently obvious uses of under-aligned objects don't get
3470   ///   miscompiled; for example, a placement new into the address of
3471   ///   a local variable.  In such a case, it's quite reasonable to
3472   ///   just ignore the returned alignment when it isn't from an
3473   ///   explicit source.
3474   Address EmitPointerWithAlignment(const Expr *Addr,
3475                                    AlignmentSource *Source = nullptr);
3476 
3477   void EmitSanitizerStatReport(llvm::SanitizerStatKind SSK);
3478 
3479 private:
3480   QualType getVarArgType(const Expr *Arg);
3481 
3482   const TargetCodeGenInfo &getTargetHooks() const {
3483     return CGM.getTargetCodeGenInfo();
3484   }
3485 
3486   void EmitDeclMetadata();
3487 
3488   BlockByrefHelpers *buildByrefHelpers(llvm::StructType &byrefType,
3489                                   const AutoVarEmission &emission);
3490 
3491   void AddObjCARCExceptionMetadata(llvm::Instruction *Inst);
3492 
3493   llvm::Value *GetValueForARMHint(unsigned BuiltinID);
3494 };
3495 
3496 /// Helper class with most of the code for saving a value for a
3497 /// conditional expression cleanup.
3498 struct DominatingLLVMValue {
3499   typedef llvm::PointerIntPair<llvm::Value*, 1, bool> saved_type;
3500 
3501   /// Answer whether the given value needs extra work to be saved.
3502   static bool needsSaving(llvm::Value *value) {
3503     // If it's not an instruction, we don't need to save.
3504     if (!isa<llvm::Instruction>(value)) return false;
3505 
3506     // If it's an instruction in the entry block, we don't need to save.
3507     llvm::BasicBlock *block = cast<llvm::Instruction>(value)->getParent();
3508     return (block != &block->getParent()->getEntryBlock());
3509   }
3510 
3511   /// Try to save the given value.
3512   static saved_type save(CodeGenFunction &CGF, llvm::Value *value) {
3513     if (!needsSaving(value)) return saved_type(value, false);
3514 
3515     // Otherwise, we need an alloca.
3516     auto align = CharUnits::fromQuantity(
3517               CGF.CGM.getDataLayout().getPrefTypeAlignment(value->getType()));
3518     Address alloca =
3519       CGF.CreateTempAlloca(value->getType(), align, "cond-cleanup.save");
3520     CGF.Builder.CreateStore(value, alloca);
3521 
3522     return saved_type(alloca.getPointer(), true);
3523   }
3524 
3525   static llvm::Value *restore(CodeGenFunction &CGF, saved_type value) {
3526     // If the value says it wasn't saved, trust that it's still dominating.
3527     if (!value.getInt()) return value.getPointer();
3528 
3529     // Otherwise, it should be an alloca instruction, as set up in save().
3530     auto alloca = cast<llvm::AllocaInst>(value.getPointer());
3531     return CGF.Builder.CreateAlignedLoad(alloca, alloca->getAlignment());
3532   }
3533 };
3534 
3535 /// A partial specialization of DominatingValue for llvm::Values that
3536 /// might be llvm::Instructions.
3537 template <class T> struct DominatingPointer<T,true> : DominatingLLVMValue {
3538   typedef T *type;
3539   static type restore(CodeGenFunction &CGF, saved_type value) {
3540     return static_cast<T*>(DominatingLLVMValue::restore(CGF, value));
3541   }
3542 };
3543 
3544 /// A specialization of DominatingValue for Address.
3545 template <> struct DominatingValue<Address> {
3546   typedef Address type;
3547 
3548   struct saved_type {
3549     DominatingLLVMValue::saved_type SavedValue;
3550     CharUnits Alignment;
3551   };
3552 
3553   static bool needsSaving(type value) {
3554     return DominatingLLVMValue::needsSaving(value.getPointer());
3555   }
3556   static saved_type save(CodeGenFunction &CGF, type value) {
3557     return { DominatingLLVMValue::save(CGF, value.getPointer()),
3558              value.getAlignment() };
3559   }
3560   static type restore(CodeGenFunction &CGF, saved_type value) {
3561     return Address(DominatingLLVMValue::restore(CGF, value.SavedValue),
3562                    value.Alignment);
3563   }
3564 };
3565 
3566 /// A specialization of DominatingValue for RValue.
3567 template <> struct DominatingValue<RValue> {
3568   typedef RValue type;
3569   class saved_type {
3570     enum Kind { ScalarLiteral, ScalarAddress, AggregateLiteral,
3571                 AggregateAddress, ComplexAddress };
3572 
3573     llvm::Value *Value;
3574     unsigned K : 3;
3575     unsigned Align : 29;
3576     saved_type(llvm::Value *v, Kind k, unsigned a = 0)
3577       : Value(v), K(k), Align(a) {}
3578 
3579   public:
3580     static bool needsSaving(RValue value);
3581     static saved_type save(CodeGenFunction &CGF, RValue value);
3582     RValue restore(CodeGenFunction &CGF);
3583 
3584     // implementations in CGCleanup.cpp
3585   };
3586 
3587   static bool needsSaving(type value) {
3588     return saved_type::needsSaving(value);
3589   }
3590   static saved_type save(CodeGenFunction &CGF, type value) {
3591     return saved_type::save(CGF, value);
3592   }
3593   static type restore(CodeGenFunction &CGF, saved_type value) {
3594     return value.restore(CGF);
3595   }
3596 };
3597 
3598 }  // end namespace CodeGen
3599 }  // end namespace clang
3600 
3601 #endif
3602