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/MapVector.h"
38 #include "llvm/ADT/SmallVector.h"
39 #include "llvm/IR/ValueHandle.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Transforms/Utils/SanitizerStats.h"
42 
43 namespace llvm {
44 class BasicBlock;
45 class LLVMContext;
46 class MDNode;
47 class Module;
48 class SwitchInst;
49 class Twine;
50 class Value;
51 class CallSite;
52 }
53 
54 namespace clang {
55 class ASTContext;
56 class BlockDecl;
57 class CXXDestructorDecl;
58 class CXXForRangeStmt;
59 class CXXTryStmt;
60 class Decl;
61 class LabelDecl;
62 class EnumConstantDecl;
63 class FunctionDecl;
64 class FunctionProtoType;
65 class LabelStmt;
66 class ObjCContainerDecl;
67 class ObjCInterfaceDecl;
68 class ObjCIvarDecl;
69 class ObjCMethodDecl;
70 class ObjCImplementationDecl;
71 class ObjCPropertyImplDecl;
72 class TargetInfo;
73 class VarDecl;
74 class ObjCForCollectionStmt;
75 class ObjCAtTryStmt;
76 class ObjCAtThrowStmt;
77 class ObjCAtSynchronizedStmt;
78 class ObjCAutoreleasePoolStmt;
79 
80 namespace analyze_os_log {
81 class OSLogBufferLayout;
82 }
83 
84 namespace CodeGen {
85 class CodeGenTypes;
86 class CGCallee;
87 class CGFunctionInfo;
88 class CGRecordLayout;
89 class CGBlockInfo;
90 class CGCXXABI;
91 class BlockByrefHelpers;
92 class BlockByrefInfo;
93 class BlockFlags;
94 class BlockFieldFlags;
95 class RegionCodeGenTy;
96 class TargetCodeGenInfo;
97 struct OMPTaskDataTy;
98 struct CGCoroData;
99 
100 /// The kind of evaluation to perform on values of a particular
101 /// type.  Basically, is the code in CGExprScalar, CGExprComplex, or
102 /// CGExprAgg?
103 ///
104 /// TODO: should vectors maybe be split out into their own thing?
105 enum TypeEvaluationKind {
106   TEK_Scalar,
107   TEK_Complex,
108   TEK_Aggregate
109 };
110 
111 #define LIST_SANITIZER_CHECKS                                                  \
112   SANITIZER_CHECK(AddOverflow, add_overflow, 0)                                \
113   SANITIZER_CHECK(BuiltinUnreachable, builtin_unreachable, 0)                  \
114   SANITIZER_CHECK(CFICheckFail, cfi_check_fail, 0)                             \
115   SANITIZER_CHECK(DivremOverflow, divrem_overflow, 0)                          \
116   SANITIZER_CHECK(DynamicTypeCacheMiss, dynamic_type_cache_miss, 0)            \
117   SANITIZER_CHECK(FloatCastOverflow, float_cast_overflow, 0)                   \
118   SANITIZER_CHECK(FunctionTypeMismatch, function_type_mismatch, 0)             \
119   SANITIZER_CHECK(InvalidBuiltin, invalid_builtin, 0)                          \
120   SANITIZER_CHECK(LoadInvalidValue, load_invalid_value, 0)                     \
121   SANITIZER_CHECK(MissingReturn, missing_return, 0)                            \
122   SANITIZER_CHECK(MulOverflow, mul_overflow, 0)                                \
123   SANITIZER_CHECK(NegateOverflow, negate_overflow, 0)                          \
124   SANITIZER_CHECK(NullabilityArg, nullability_arg, 0)                          \
125   SANITIZER_CHECK(NullabilityReturn, nullability_return, 1)                    \
126   SANITIZER_CHECK(NonnullArg, nonnull_arg, 0)                                  \
127   SANITIZER_CHECK(NonnullReturn, nonnull_return, 1)                            \
128   SANITIZER_CHECK(OutOfBounds, out_of_bounds, 0)                               \
129   SANITIZER_CHECK(PointerOverflow, pointer_overflow, 0)                        \
130   SANITIZER_CHECK(ShiftOutOfBounds, shift_out_of_bounds, 0)                    \
131   SANITIZER_CHECK(SubOverflow, sub_overflow, 0)                                \
132   SANITIZER_CHECK(TypeMismatch, type_mismatch, 1)                              \
133   SANITIZER_CHECK(VLABoundNotPositive, vla_bound_not_positive, 0)
134 
135 enum SanitizerHandler {
136 #define SANITIZER_CHECK(Enum, Name, Version) Enum,
137   LIST_SANITIZER_CHECKS
138 #undef SANITIZER_CHECK
139 };
140 
141 /// CodeGenFunction - This class organizes the per-function state that is used
142 /// while generating LLVM code.
143 class CodeGenFunction : public CodeGenTypeCache {
144   CodeGenFunction(const CodeGenFunction &) = delete;
145   void operator=(const CodeGenFunction &) = delete;
146 
147   friend class CGCXXABI;
148 public:
149   /// A jump destination is an abstract label, branching to which may
150   /// require a jump out through normal cleanups.
151   struct JumpDest {
152     JumpDest() : Block(nullptr), ScopeDepth(), Index(0) {}
153     JumpDest(llvm::BasicBlock *Block,
154              EHScopeStack::stable_iterator Depth,
155              unsigned Index)
156       : Block(Block), ScopeDepth(Depth), Index(Index) {}
157 
158     bool isValid() const { return Block != nullptr; }
159     llvm::BasicBlock *getBlock() const { return Block; }
160     EHScopeStack::stable_iterator getScopeDepth() const { return ScopeDepth; }
161     unsigned getDestIndex() const { return Index; }
162 
163     // This should be used cautiously.
164     void setScopeDepth(EHScopeStack::stable_iterator depth) {
165       ScopeDepth = depth;
166     }
167 
168   private:
169     llvm::BasicBlock *Block;
170     EHScopeStack::stable_iterator ScopeDepth;
171     unsigned Index;
172   };
173 
174   CodeGenModule &CGM;  // Per-module state.
175   const TargetInfo &Target;
176 
177   typedef std::pair<llvm::Value *, llvm::Value *> ComplexPairTy;
178   LoopInfoStack LoopStack;
179   CGBuilderTy Builder;
180 
181   // Stores variables for which we can't generate correct lifetime markers
182   // because of jumps.
183   VarBypassDetector Bypasses;
184 
185   // CodeGen lambda for loops and support for ordered clause
186   typedef llvm::function_ref<void(CodeGenFunction &, const OMPLoopDirective &,
187                                   JumpDest)>
188       CodeGenLoopTy;
189   typedef llvm::function_ref<void(CodeGenFunction &, SourceLocation,
190                                   const unsigned, const bool)>
191       CodeGenOrderedTy;
192 
193   // Codegen lambda for loop bounds in worksharing loop constructs
194   typedef llvm::function_ref<std::pair<LValue, LValue>(
195       CodeGenFunction &, const OMPExecutableDirective &S)>
196       CodeGenLoopBoundsTy;
197 
198   // Codegen lambda for loop bounds in dispatch-based loop implementation
199   typedef llvm::function_ref<std::pair<llvm::Value *, llvm::Value *>(
200       CodeGenFunction &, const OMPExecutableDirective &S, Address LB,
201       Address UB)>
202       CodeGenDispatchBoundsTy;
203 
204   /// \brief CGBuilder insert helper. This function is called after an
205   /// instruction is created using Builder.
206   void InsertHelper(llvm::Instruction *I, const llvm::Twine &Name,
207                     llvm::BasicBlock *BB,
208                     llvm::BasicBlock::iterator InsertPt) const;
209 
210   /// CurFuncDecl - Holds the Decl for the current outermost
211   /// non-closure context.
212   const Decl *CurFuncDecl;
213   /// CurCodeDecl - This is the inner-most code context, which includes blocks.
214   const Decl *CurCodeDecl;
215   const CGFunctionInfo *CurFnInfo;
216   QualType FnRetTy;
217   llvm::Function *CurFn;
218 
219   // Holds coroutine data if the current function is a coroutine. We use a
220   // wrapper to manage its lifetime, so that we don't have to define CGCoroData
221   // in this header.
222   struct CGCoroInfo {
223     std::unique_ptr<CGCoroData> Data;
224     CGCoroInfo();
225     ~CGCoroInfo();
226   };
227   CGCoroInfo CurCoro;
228 
229   bool isCoroutine() const {
230     return CurCoro.Data != nullptr;
231   }
232 
233   /// CurGD - The GlobalDecl for the current function being compiled.
234   GlobalDecl CurGD;
235 
236   /// PrologueCleanupDepth - The cleanup depth enclosing all the
237   /// cleanups associated with the parameters.
238   EHScopeStack::stable_iterator PrologueCleanupDepth;
239 
240   /// ReturnBlock - Unified return block.
241   JumpDest ReturnBlock;
242 
243   /// ReturnValue - The temporary alloca to hold the return
244   /// value. This is invalid iff the function has no return value.
245   Address ReturnValue;
246 
247   /// Return true if a label was seen in the current scope.
248   bool hasLabelBeenSeenInCurrentScope() const {
249     if (CurLexicalScope)
250       return CurLexicalScope->hasLabels();
251     return !LabelMap.empty();
252   }
253 
254   /// AllocaInsertPoint - This is an instruction in the entry block before which
255   /// we prefer to insert allocas.
256   llvm::AssertingVH<llvm::Instruction> AllocaInsertPt;
257 
258   /// \brief API for captured statement code generation.
259   class CGCapturedStmtInfo {
260   public:
261     explicit CGCapturedStmtInfo(CapturedRegionKind K = CR_Default)
262         : Kind(K), ThisValue(nullptr), CXXThisFieldDecl(nullptr) {}
263     explicit CGCapturedStmtInfo(const CapturedStmt &S,
264                                 CapturedRegionKind K = CR_Default)
265       : Kind(K), ThisValue(nullptr), CXXThisFieldDecl(nullptr) {
266 
267       RecordDecl::field_iterator Field =
268         S.getCapturedRecordDecl()->field_begin();
269       for (CapturedStmt::const_capture_iterator I = S.capture_begin(),
270                                                 E = S.capture_end();
271            I != E; ++I, ++Field) {
272         if (I->capturesThis())
273           CXXThisFieldDecl = *Field;
274         else if (I->capturesVariable())
275           CaptureFields[I->getCapturedVar()->getCanonicalDecl()] = *Field;
276         else if (I->capturesVariableByCopy())
277           CaptureFields[I->getCapturedVar()->getCanonicalDecl()] = *Field;
278       }
279     }
280 
281     virtual ~CGCapturedStmtInfo();
282 
283     CapturedRegionKind getKind() const { return Kind; }
284 
285     virtual void setContextValue(llvm::Value *V) { ThisValue = V; }
286     // \brief Retrieve the value of the context parameter.
287     virtual llvm::Value *getContextValue() const { return ThisValue; }
288 
289     /// \brief Lookup the captured field decl for a variable.
290     virtual const FieldDecl *lookup(const VarDecl *VD) const {
291       return CaptureFields.lookup(VD->getCanonicalDecl());
292     }
293 
294     bool isCXXThisExprCaptured() const { return getThisFieldDecl() != nullptr; }
295     virtual FieldDecl *getThisFieldDecl() const { return CXXThisFieldDecl; }
296 
297     static bool classof(const CGCapturedStmtInfo *) {
298       return true;
299     }
300 
301     /// \brief Emit the captured statement body.
302     virtual void EmitBody(CodeGenFunction &CGF, const Stmt *S) {
303       CGF.incrementProfileCounter(S);
304       CGF.EmitStmt(S);
305     }
306 
307     /// \brief Get the name of the capture helper.
308     virtual StringRef getHelperName() const { return "__captured_stmt"; }
309 
310   private:
311     /// \brief The kind of captured statement being generated.
312     CapturedRegionKind Kind;
313 
314     /// \brief Keep the map between VarDecl and FieldDecl.
315     llvm::SmallDenseMap<const VarDecl *, FieldDecl *> CaptureFields;
316 
317     /// \brief The base address of the captured record, passed in as the first
318     /// argument of the parallel region function.
319     llvm::Value *ThisValue;
320 
321     /// \brief Captured 'this' type.
322     FieldDecl *CXXThisFieldDecl;
323   };
324   CGCapturedStmtInfo *CapturedStmtInfo;
325 
326   /// \brief RAII for correct setting/restoring of CapturedStmtInfo.
327   class CGCapturedStmtRAII {
328   private:
329     CodeGenFunction &CGF;
330     CGCapturedStmtInfo *PrevCapturedStmtInfo;
331   public:
332     CGCapturedStmtRAII(CodeGenFunction &CGF,
333                        CGCapturedStmtInfo *NewCapturedStmtInfo)
334         : CGF(CGF), PrevCapturedStmtInfo(CGF.CapturedStmtInfo) {
335       CGF.CapturedStmtInfo = NewCapturedStmtInfo;
336     }
337     ~CGCapturedStmtRAII() { CGF.CapturedStmtInfo = PrevCapturedStmtInfo; }
338   };
339 
340   /// An abstract representation of regular/ObjC call/message targets.
341   class AbstractCallee {
342     /// The function declaration of the callee.
343     const Decl *CalleeDecl;
344 
345   public:
346     AbstractCallee() : CalleeDecl(nullptr) {}
347     AbstractCallee(const FunctionDecl *FD) : CalleeDecl(FD) {}
348     AbstractCallee(const ObjCMethodDecl *OMD) : CalleeDecl(OMD) {}
349     bool hasFunctionDecl() const {
350       return dyn_cast_or_null<FunctionDecl>(CalleeDecl);
351     }
352     const Decl *getDecl() const { return CalleeDecl; }
353     unsigned getNumParams() const {
354       if (const auto *FD = dyn_cast<FunctionDecl>(CalleeDecl))
355         return FD->getNumParams();
356       return cast<ObjCMethodDecl>(CalleeDecl)->param_size();
357     }
358     const ParmVarDecl *getParamDecl(unsigned I) const {
359       if (const auto *FD = dyn_cast<FunctionDecl>(CalleeDecl))
360         return FD->getParamDecl(I);
361       return *(cast<ObjCMethodDecl>(CalleeDecl)->param_begin() + I);
362     }
363   };
364 
365   /// \brief Sanitizers enabled for this function.
366   SanitizerSet SanOpts;
367 
368   /// \brief True if CodeGen currently emits code implementing sanitizer checks.
369   bool IsSanitizerScope;
370 
371   /// \brief RAII object to set/unset CodeGenFunction::IsSanitizerScope.
372   class SanitizerScope {
373     CodeGenFunction *CGF;
374   public:
375     SanitizerScope(CodeGenFunction *CGF);
376     ~SanitizerScope();
377   };
378 
379   /// In C++, whether we are code generating a thunk.  This controls whether we
380   /// should emit cleanups.
381   bool CurFuncIsThunk;
382 
383   /// In ARC, whether we should autorelease the return value.
384   bool AutoreleaseResult;
385 
386   /// Whether we processed a Microsoft-style asm block during CodeGen. These can
387   /// potentially set the return value.
388   bool SawAsmBlock;
389 
390   const FunctionDecl *CurSEHParent = nullptr;
391 
392   /// True if the current function is an outlined SEH helper. This can be a
393   /// finally block or filter expression.
394   bool IsOutlinedSEHHelper;
395 
396   const CodeGen::CGBlockInfo *BlockInfo;
397   llvm::Value *BlockPointer;
398 
399   llvm::DenseMap<const VarDecl *, FieldDecl *> LambdaCaptureFields;
400   FieldDecl *LambdaThisCaptureField;
401 
402   /// \brief A mapping from NRVO variables to the flags used to indicate
403   /// when the NRVO has been applied to this variable.
404   llvm::DenseMap<const VarDecl *, llvm::Value *> NRVOFlags;
405 
406   EHScopeStack EHStack;
407   llvm::SmallVector<char, 256> LifetimeExtendedCleanupStack;
408   llvm::SmallVector<const JumpDest *, 2> SEHTryEpilogueStack;
409 
410   llvm::Instruction *CurrentFuncletPad = nullptr;
411 
412   class CallLifetimeEnd final : public EHScopeStack::Cleanup {
413     llvm::Value *Addr;
414     llvm::Value *Size;
415 
416   public:
417     CallLifetimeEnd(Address addr, llvm::Value *size)
418         : Addr(addr.getPointer()), Size(size) {}
419 
420     void Emit(CodeGenFunction &CGF, Flags flags) override {
421       CGF.EmitLifetimeEnd(Size, Addr);
422     }
423   };
424 
425   /// Header for data within LifetimeExtendedCleanupStack.
426   struct LifetimeExtendedCleanupHeader {
427     /// The size of the following cleanup object.
428     unsigned Size;
429     /// The kind of cleanup to push: a value from the CleanupKind enumeration.
430     CleanupKind Kind;
431 
432     size_t getSize() const { return Size; }
433     CleanupKind getKind() const { return Kind; }
434   };
435 
436   /// i32s containing the indexes of the cleanup destinations.
437   Address NormalCleanupDest;
438 
439   unsigned NextCleanupDestIndex;
440 
441   /// FirstBlockInfo - The head of a singly-linked-list of block layouts.
442   CGBlockInfo *FirstBlockInfo;
443 
444   /// EHResumeBlock - Unified block containing a call to llvm.eh.resume.
445   llvm::BasicBlock *EHResumeBlock;
446 
447   /// The exception slot.  All landing pads write the current exception pointer
448   /// into this alloca.
449   llvm::Value *ExceptionSlot;
450 
451   /// The selector slot.  Under the MandatoryCleanup model, all landing pads
452   /// write the current selector value into this alloca.
453   llvm::AllocaInst *EHSelectorSlot;
454 
455   /// A stack of exception code slots. Entering an __except block pushes a slot
456   /// on the stack and leaving pops one. The __exception_code() intrinsic loads
457   /// a value from the top of the stack.
458   SmallVector<Address, 1> SEHCodeSlotStack;
459 
460   /// Value returned by __exception_info intrinsic.
461   llvm::Value *SEHInfo = nullptr;
462 
463   /// Emits a landing pad for the current EH stack.
464   llvm::BasicBlock *EmitLandingPad();
465 
466   llvm::BasicBlock *getInvokeDestImpl();
467 
468   template <class T>
469   typename DominatingValue<T>::saved_type saveValueInCond(T value) {
470     return DominatingValue<T>::save(*this, value);
471   }
472 
473 public:
474   /// ObjCEHValueStack - Stack of Objective-C exception values, used for
475   /// rethrows.
476   SmallVector<llvm::Value*, 8> ObjCEHValueStack;
477 
478   /// A class controlling the emission of a finally block.
479   class FinallyInfo {
480     /// Where the catchall's edge through the cleanup should go.
481     JumpDest RethrowDest;
482 
483     /// A function to call to enter the catch.
484     llvm::Constant *BeginCatchFn;
485 
486     /// An i1 variable indicating whether or not the @finally is
487     /// running for an exception.
488     llvm::AllocaInst *ForEHVar;
489 
490     /// An i8* variable into which the exception pointer to rethrow
491     /// has been saved.
492     llvm::AllocaInst *SavedExnVar;
493 
494   public:
495     void enter(CodeGenFunction &CGF, const Stmt *Finally,
496                llvm::Constant *beginCatchFn, llvm::Constant *endCatchFn,
497                llvm::Constant *rethrowFn);
498     void exit(CodeGenFunction &CGF);
499   };
500 
501   /// Returns true inside SEH __try blocks.
502   bool isSEHTryScope() const { return !SEHTryEpilogueStack.empty(); }
503 
504   /// Returns true while emitting a cleanuppad.
505   bool isCleanupPadScope() const {
506     return CurrentFuncletPad && isa<llvm::CleanupPadInst>(CurrentFuncletPad);
507   }
508 
509   /// pushFullExprCleanup - Push a cleanup to be run at the end of the
510   /// current full-expression.  Safe against the possibility that
511   /// we're currently inside a conditionally-evaluated expression.
512   template <class T, class... As>
513   void pushFullExprCleanup(CleanupKind kind, As... A) {
514     // If we're not in a conditional branch, or if none of the
515     // arguments requires saving, then use the unconditional cleanup.
516     if (!isInConditionalBranch())
517       return EHStack.pushCleanup<T>(kind, A...);
518 
519     // Stash values in a tuple so we can guarantee the order of saves.
520     typedef std::tuple<typename DominatingValue<As>::saved_type...> SavedTuple;
521     SavedTuple Saved{saveValueInCond(A)...};
522 
523     typedef EHScopeStack::ConditionalCleanup<T, As...> CleanupType;
524     EHStack.pushCleanupTuple<CleanupType>(kind, Saved);
525     initFullExprCleanup();
526   }
527 
528   /// \brief Queue a cleanup to be pushed after finishing the current
529   /// full-expression.
530   template <class T, class... As>
531   void pushCleanupAfterFullExpr(CleanupKind Kind, As... A) {
532     assert(!isInConditionalBranch() && "can't defer conditional cleanup");
533 
534     LifetimeExtendedCleanupHeader Header = { sizeof(T), Kind };
535 
536     size_t OldSize = LifetimeExtendedCleanupStack.size();
537     LifetimeExtendedCleanupStack.resize(
538         LifetimeExtendedCleanupStack.size() + sizeof(Header) + Header.Size);
539 
540     static_assert(sizeof(Header) % alignof(T) == 0,
541                   "Cleanup will be allocated on misaligned address");
542     char *Buffer = &LifetimeExtendedCleanupStack[OldSize];
543     new (Buffer) LifetimeExtendedCleanupHeader(Header);
544     new (Buffer + sizeof(Header)) T(A...);
545   }
546 
547   /// Set up the last cleaup that was pushed as a conditional
548   /// full-expression cleanup.
549   void initFullExprCleanup();
550 
551   /// PushDestructorCleanup - Push a cleanup to call the
552   /// complete-object destructor of an object of the given type at the
553   /// given address.  Does nothing if T is not a C++ class type with a
554   /// non-trivial destructor.
555   void PushDestructorCleanup(QualType T, Address Addr);
556 
557   /// PushDestructorCleanup - Push a cleanup to call the
558   /// complete-object variant of the given destructor on the object at
559   /// the given address.
560   void PushDestructorCleanup(const CXXDestructorDecl *Dtor, Address Addr);
561 
562   /// PopCleanupBlock - Will pop the cleanup entry on the stack and
563   /// process all branch fixups.
564   void PopCleanupBlock(bool FallThroughIsBranchThrough = false);
565 
566   /// DeactivateCleanupBlock - Deactivates the given cleanup block.
567   /// The block cannot be reactivated.  Pops it if it's the top of the
568   /// stack.
569   ///
570   /// \param DominatingIP - An instruction which is known to
571   ///   dominate the current IP (if set) and which lies along
572   ///   all paths of execution between the current IP and the
573   ///   the point at which the cleanup comes into scope.
574   void DeactivateCleanupBlock(EHScopeStack::stable_iterator Cleanup,
575                               llvm::Instruction *DominatingIP);
576 
577   /// ActivateCleanupBlock - Activates an initially-inactive cleanup.
578   /// Cannot be used to resurrect a deactivated cleanup.
579   ///
580   /// \param DominatingIP - An instruction which is known to
581   ///   dominate the current IP (if set) and which lies along
582   ///   all paths of execution between the current IP and the
583   ///   the point at which the cleanup comes into scope.
584   void ActivateCleanupBlock(EHScopeStack::stable_iterator Cleanup,
585                             llvm::Instruction *DominatingIP);
586 
587   /// \brief Enters a new scope for capturing cleanups, all of which
588   /// will be executed once the scope is exited.
589   class RunCleanupsScope {
590     EHScopeStack::stable_iterator CleanupStackDepth;
591     size_t LifetimeExtendedCleanupStackSize;
592     bool OldDidCallStackSave;
593   protected:
594     bool PerformCleanup;
595   private:
596 
597     RunCleanupsScope(const RunCleanupsScope &) = delete;
598     void operator=(const RunCleanupsScope &) = delete;
599 
600   protected:
601     CodeGenFunction& CGF;
602 
603   public:
604     /// \brief Enter a new cleanup scope.
605     explicit RunCleanupsScope(CodeGenFunction &CGF)
606       : PerformCleanup(true), CGF(CGF)
607     {
608       CleanupStackDepth = CGF.EHStack.stable_begin();
609       LifetimeExtendedCleanupStackSize =
610           CGF.LifetimeExtendedCleanupStack.size();
611       OldDidCallStackSave = CGF.DidCallStackSave;
612       CGF.DidCallStackSave = false;
613     }
614 
615     /// \brief Exit this cleanup scope, emitting any accumulated cleanups.
616     ~RunCleanupsScope() {
617       if (PerformCleanup)
618         ForceCleanup();
619     }
620 
621     /// \brief Determine whether this scope requires any cleanups.
622     bool requiresCleanups() const {
623       return CGF.EHStack.stable_begin() != CleanupStackDepth;
624     }
625 
626     /// \brief Force the emission of cleanups now, instead of waiting
627     /// until this object is destroyed.
628     /// \param ValuesToReload - A list of values that need to be available at
629     /// the insertion point after cleanup emission. If cleanup emission created
630     /// a shared cleanup block, these value pointers will be rewritten.
631     /// Otherwise, they not will be modified.
632     void ForceCleanup(std::initializer_list<llvm::Value**> ValuesToReload = {}) {
633       assert(PerformCleanup && "Already forced cleanup");
634       CGF.DidCallStackSave = OldDidCallStackSave;
635       CGF.PopCleanupBlocks(CleanupStackDepth, LifetimeExtendedCleanupStackSize,
636                            ValuesToReload);
637       PerformCleanup = false;
638     }
639   };
640 
641   class LexicalScope : public RunCleanupsScope {
642     SourceRange Range;
643     SmallVector<const LabelDecl*, 4> Labels;
644     LexicalScope *ParentScope;
645 
646     LexicalScope(const LexicalScope &) = delete;
647     void operator=(const LexicalScope &) = delete;
648 
649   public:
650     /// \brief Enter a new cleanup scope.
651     explicit LexicalScope(CodeGenFunction &CGF, SourceRange Range)
652       : RunCleanupsScope(CGF), Range(Range), ParentScope(CGF.CurLexicalScope) {
653       CGF.CurLexicalScope = this;
654       if (CGDebugInfo *DI = CGF.getDebugInfo())
655         DI->EmitLexicalBlockStart(CGF.Builder, Range.getBegin());
656     }
657 
658     void addLabel(const LabelDecl *label) {
659       assert(PerformCleanup && "adding label to dead scope?");
660       Labels.push_back(label);
661     }
662 
663     /// \brief Exit this cleanup scope, emitting any accumulated
664     /// cleanups.
665     ~LexicalScope() {
666       if (CGDebugInfo *DI = CGF.getDebugInfo())
667         DI->EmitLexicalBlockEnd(CGF.Builder, Range.getEnd());
668 
669       // If we should perform a cleanup, force them now.  Note that
670       // this ends the cleanup scope before rescoping any labels.
671       if (PerformCleanup) {
672         ApplyDebugLocation DL(CGF, Range.getEnd());
673         ForceCleanup();
674       }
675     }
676 
677     /// \brief Force the emission of cleanups now, instead of waiting
678     /// until this object is destroyed.
679     void ForceCleanup() {
680       CGF.CurLexicalScope = ParentScope;
681       RunCleanupsScope::ForceCleanup();
682 
683       if (!Labels.empty())
684         rescopeLabels();
685     }
686 
687     bool hasLabels() const {
688       return !Labels.empty();
689     }
690 
691     void rescopeLabels();
692   };
693 
694   typedef llvm::DenseMap<const Decl *, Address> DeclMapTy;
695 
696   /// The class used to assign some variables some temporarily addresses.
697   class OMPMapVars {
698     DeclMapTy SavedLocals;
699     DeclMapTy SavedTempAddresses;
700     OMPMapVars(const OMPMapVars &) = delete;
701     void operator=(const OMPMapVars &) = delete;
702 
703   public:
704     explicit OMPMapVars() = default;
705     ~OMPMapVars() {
706       assert(SavedLocals.empty() && "Did not restored original addresses.");
707     };
708 
709     /// Sets the address of the variable \p LocalVD to be \p TempAddr in
710     /// function \p CGF.
711     /// \return true if at least one variable was set already, false otherwise.
712     bool setVarAddr(CodeGenFunction &CGF, const VarDecl *LocalVD,
713                     Address TempAddr) {
714       LocalVD = LocalVD->getCanonicalDecl();
715       // Only save it once.
716       if (SavedLocals.count(LocalVD)) return false;
717 
718       // Copy the existing local entry to SavedLocals.
719       auto it = CGF.LocalDeclMap.find(LocalVD);
720       if (it != CGF.LocalDeclMap.end())
721         SavedLocals.try_emplace(LocalVD, it->second);
722       else
723         SavedLocals.try_emplace(LocalVD, Address::invalid());
724 
725       // Generate the private entry.
726       QualType VarTy = LocalVD->getType();
727       if (VarTy->isReferenceType()) {
728         Address Temp = CGF.CreateMemTemp(VarTy);
729         CGF.Builder.CreateStore(TempAddr.getPointer(), Temp);
730         TempAddr = Temp;
731       }
732       SavedTempAddresses.try_emplace(LocalVD, TempAddr);
733 
734       return true;
735     }
736 
737     /// Applies new addresses to the list of the variables.
738     /// \return true if at least one variable is using new address, false
739     /// otherwise.
740     bool apply(CodeGenFunction &CGF) {
741       copyInto(SavedTempAddresses, CGF.LocalDeclMap);
742       SavedTempAddresses.clear();
743       return !SavedLocals.empty();
744     }
745 
746     /// Restores original addresses of the variables.
747     void restore(CodeGenFunction &CGF) {
748       if (!SavedLocals.empty()) {
749         copyInto(SavedLocals, CGF.LocalDeclMap);
750         SavedLocals.clear();
751       }
752     }
753 
754   private:
755     /// Copy all the entries in the source map over the corresponding
756     /// entries in the destination, which must exist.
757     static void copyInto(const DeclMapTy &Src, DeclMapTy &Dest) {
758       for (auto &Pair : Src) {
759         if (!Pair.second.isValid()) {
760           Dest.erase(Pair.first);
761           continue;
762         }
763 
764         auto I = Dest.find(Pair.first);
765         if (I != Dest.end())
766           I->second = Pair.second;
767         else
768           Dest.insert(Pair);
769       }
770     }
771   };
772 
773   /// The scope used to remap some variables as private in the OpenMP loop body
774   /// (or other captured region emitted without outlining), and to restore old
775   /// vars back on exit.
776   class OMPPrivateScope : public RunCleanupsScope {
777     OMPMapVars MappedVars;
778     OMPPrivateScope(const OMPPrivateScope &) = delete;
779     void operator=(const OMPPrivateScope &) = delete;
780 
781   public:
782     /// Enter a new OpenMP private scope.
783     explicit OMPPrivateScope(CodeGenFunction &CGF) : RunCleanupsScope(CGF) {}
784 
785     /// Registers \p LocalVD variable as a private and apply \p PrivateGen
786     /// function for it to generate corresponding private variable. \p
787     /// PrivateGen returns an address of the generated private variable.
788     /// \return true if the variable is registered as private, false if it has
789     /// been privatized already.
790     bool addPrivate(const VarDecl *LocalVD,
791                     const llvm::function_ref<Address()> PrivateGen) {
792       assert(PerformCleanup && "adding private to dead scope");
793       return MappedVars.setVarAddr(CGF, LocalVD, PrivateGen());
794     }
795 
796     /// Privatizes local variables previously registered as private.
797     /// Registration is separate from the actual privatization to allow
798     /// initializers use values of the original variables, not the private one.
799     /// This is important, for example, if the private variable is a class
800     /// variable initialized by a constructor that references other private
801     /// variables. But at initialization original variables must be used, not
802     /// private copies.
803     /// \return true if at least one variable was privatized, false otherwise.
804     bool Privatize() { return MappedVars.apply(CGF); }
805 
806     void ForceCleanup() {
807       RunCleanupsScope::ForceCleanup();
808       MappedVars.restore(CGF);
809     }
810 
811     /// Exit scope - all the mapped variables are restored.
812     ~OMPPrivateScope() {
813       if (PerformCleanup)
814         ForceCleanup();
815     }
816 
817     /// Checks if the global variable is captured in current function.
818     bool isGlobalVarCaptured(const VarDecl *VD) const {
819       VD = VD->getCanonicalDecl();
820       return !VD->isLocalVarDeclOrParm() && CGF.LocalDeclMap.count(VD) > 0;
821     }
822   };
823 
824   /// \brief Takes the old cleanup stack size and emits the cleanup blocks
825   /// that have been added.
826   void
827   PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize,
828                    std::initializer_list<llvm::Value **> ValuesToReload = {});
829 
830   /// \brief Takes the old cleanup stack size and emits the cleanup blocks
831   /// that have been added, then adds all lifetime-extended cleanups from
832   /// the given position to the stack.
833   void
834   PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize,
835                    size_t OldLifetimeExtendedStackSize,
836                    std::initializer_list<llvm::Value **> ValuesToReload = {});
837 
838   void ResolveBranchFixups(llvm::BasicBlock *Target);
839 
840   /// The given basic block lies in the current EH scope, but may be a
841   /// target of a potentially scope-crossing jump; get a stable handle
842   /// to which we can perform this jump later.
843   JumpDest getJumpDestInCurrentScope(llvm::BasicBlock *Target) {
844     return JumpDest(Target,
845                     EHStack.getInnermostNormalCleanup(),
846                     NextCleanupDestIndex++);
847   }
848 
849   /// The given basic block lies in the current EH scope, but may be a
850   /// target of a potentially scope-crossing jump; get a stable handle
851   /// to which we can perform this jump later.
852   JumpDest getJumpDestInCurrentScope(StringRef Name = StringRef()) {
853     return getJumpDestInCurrentScope(createBasicBlock(Name));
854   }
855 
856   /// EmitBranchThroughCleanup - Emit a branch from the current insert
857   /// block through the normal cleanup handling code (if any) and then
858   /// on to \arg Dest.
859   void EmitBranchThroughCleanup(JumpDest Dest);
860 
861   /// isObviouslyBranchWithoutCleanups - Return true if a branch to the
862   /// specified destination obviously has no cleanups to run.  'false' is always
863   /// a conservatively correct answer for this method.
864   bool isObviouslyBranchWithoutCleanups(JumpDest Dest) const;
865 
866   /// popCatchScope - Pops the catch scope at the top of the EHScope
867   /// stack, emitting any required code (other than the catch handlers
868   /// themselves).
869   void popCatchScope();
870 
871   llvm::BasicBlock *getEHResumeBlock(bool isCleanup);
872   llvm::BasicBlock *getEHDispatchBlock(EHScopeStack::stable_iterator scope);
873   llvm::BasicBlock *getMSVCDispatchBlock(EHScopeStack::stable_iterator scope);
874 
875   /// An object to manage conditionally-evaluated expressions.
876   class ConditionalEvaluation {
877     llvm::BasicBlock *StartBB;
878 
879   public:
880     ConditionalEvaluation(CodeGenFunction &CGF)
881       : StartBB(CGF.Builder.GetInsertBlock()) {}
882 
883     void begin(CodeGenFunction &CGF) {
884       assert(CGF.OutermostConditional != this);
885       if (!CGF.OutermostConditional)
886         CGF.OutermostConditional = this;
887     }
888 
889     void end(CodeGenFunction &CGF) {
890       assert(CGF.OutermostConditional != nullptr);
891       if (CGF.OutermostConditional == this)
892         CGF.OutermostConditional = nullptr;
893     }
894 
895     /// Returns a block which will be executed prior to each
896     /// evaluation of the conditional code.
897     llvm::BasicBlock *getStartingBlock() const {
898       return StartBB;
899     }
900   };
901 
902   /// isInConditionalBranch - Return true if we're currently emitting
903   /// one branch or the other of a conditional expression.
904   bool isInConditionalBranch() const { return OutermostConditional != nullptr; }
905 
906   void setBeforeOutermostConditional(llvm::Value *value, Address addr) {
907     assert(isInConditionalBranch());
908     llvm::BasicBlock *block = OutermostConditional->getStartingBlock();
909     auto store = new llvm::StoreInst(value, addr.getPointer(), &block->back());
910     store->setAlignment(addr.getAlignment().getQuantity());
911   }
912 
913   /// An RAII object to record that we're evaluating a statement
914   /// expression.
915   class StmtExprEvaluation {
916     CodeGenFunction &CGF;
917 
918     /// We have to save the outermost conditional: cleanups in a
919     /// statement expression aren't conditional just because the
920     /// StmtExpr is.
921     ConditionalEvaluation *SavedOutermostConditional;
922 
923   public:
924     StmtExprEvaluation(CodeGenFunction &CGF)
925       : CGF(CGF), SavedOutermostConditional(CGF.OutermostConditional) {
926       CGF.OutermostConditional = nullptr;
927     }
928 
929     ~StmtExprEvaluation() {
930       CGF.OutermostConditional = SavedOutermostConditional;
931       CGF.EnsureInsertPoint();
932     }
933   };
934 
935   /// An object which temporarily prevents a value from being
936   /// destroyed by aggressive peephole optimizations that assume that
937   /// all uses of a value have been realized in the IR.
938   class PeepholeProtection {
939     llvm::Instruction *Inst;
940     friend class CodeGenFunction;
941 
942   public:
943     PeepholeProtection() : Inst(nullptr) {}
944   };
945 
946   /// A non-RAII class containing all the information about a bound
947   /// opaque value.  OpaqueValueMapping, below, is a RAII wrapper for
948   /// this which makes individual mappings very simple; using this
949   /// class directly is useful when you have a variable number of
950   /// opaque values or don't want the RAII functionality for some
951   /// reason.
952   class OpaqueValueMappingData {
953     const OpaqueValueExpr *OpaqueValue;
954     bool BoundLValue;
955     CodeGenFunction::PeepholeProtection Protection;
956 
957     OpaqueValueMappingData(const OpaqueValueExpr *ov,
958                            bool boundLValue)
959       : OpaqueValue(ov), BoundLValue(boundLValue) {}
960   public:
961     OpaqueValueMappingData() : OpaqueValue(nullptr) {}
962 
963     static bool shouldBindAsLValue(const Expr *expr) {
964       // gl-values should be bound as l-values for obvious reasons.
965       // Records should be bound as l-values because IR generation
966       // always keeps them in memory.  Expressions of function type
967       // act exactly like l-values but are formally required to be
968       // r-values in C.
969       return expr->isGLValue() ||
970              expr->getType()->isFunctionType() ||
971              hasAggregateEvaluationKind(expr->getType());
972     }
973 
974     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
975                                        const OpaqueValueExpr *ov,
976                                        const Expr *e) {
977       if (shouldBindAsLValue(ov))
978         return bind(CGF, ov, CGF.EmitLValue(e));
979       return bind(CGF, ov, CGF.EmitAnyExpr(e));
980     }
981 
982     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
983                                        const OpaqueValueExpr *ov,
984                                        const LValue &lv) {
985       assert(shouldBindAsLValue(ov));
986       CGF.OpaqueLValues.insert(std::make_pair(ov, lv));
987       return OpaqueValueMappingData(ov, true);
988     }
989 
990     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
991                                        const OpaqueValueExpr *ov,
992                                        const RValue &rv) {
993       assert(!shouldBindAsLValue(ov));
994       CGF.OpaqueRValues.insert(std::make_pair(ov, rv));
995 
996       OpaqueValueMappingData data(ov, false);
997 
998       // Work around an extremely aggressive peephole optimization in
999       // EmitScalarConversion which assumes that all other uses of a
1000       // value are extant.
1001       data.Protection = CGF.protectFromPeepholes(rv);
1002 
1003       return data;
1004     }
1005 
1006     bool isValid() const { return OpaqueValue != nullptr; }
1007     void clear() { OpaqueValue = nullptr; }
1008 
1009     void unbind(CodeGenFunction &CGF) {
1010       assert(OpaqueValue && "no data to unbind!");
1011 
1012       if (BoundLValue) {
1013         CGF.OpaqueLValues.erase(OpaqueValue);
1014       } else {
1015         CGF.OpaqueRValues.erase(OpaqueValue);
1016         CGF.unprotectFromPeepholes(Protection);
1017       }
1018     }
1019   };
1020 
1021   /// An RAII object to set (and then clear) a mapping for an OpaqueValueExpr.
1022   class OpaqueValueMapping {
1023     CodeGenFunction &CGF;
1024     OpaqueValueMappingData Data;
1025 
1026   public:
1027     static bool shouldBindAsLValue(const Expr *expr) {
1028       return OpaqueValueMappingData::shouldBindAsLValue(expr);
1029     }
1030 
1031     /// Build the opaque value mapping for the given conditional
1032     /// operator if it's the GNU ?: extension.  This is a common
1033     /// enough pattern that the convenience operator is really
1034     /// helpful.
1035     ///
1036     OpaqueValueMapping(CodeGenFunction &CGF,
1037                        const AbstractConditionalOperator *op) : CGF(CGF) {
1038       if (isa<ConditionalOperator>(op))
1039         // Leave Data empty.
1040         return;
1041 
1042       const BinaryConditionalOperator *e = cast<BinaryConditionalOperator>(op);
1043       Data = OpaqueValueMappingData::bind(CGF, e->getOpaqueValue(),
1044                                           e->getCommon());
1045     }
1046 
1047     /// Build the opaque value mapping for an OpaqueValueExpr whose source
1048     /// expression is set to the expression the OVE represents.
1049     OpaqueValueMapping(CodeGenFunction &CGF, const OpaqueValueExpr *OV)
1050         : CGF(CGF) {
1051       if (OV) {
1052         assert(OV->getSourceExpr() && "wrong form of OpaqueValueMapping used "
1053                                       "for OVE with no source expression");
1054         Data = OpaqueValueMappingData::bind(CGF, OV, OV->getSourceExpr());
1055       }
1056     }
1057 
1058     OpaqueValueMapping(CodeGenFunction &CGF,
1059                        const OpaqueValueExpr *opaqueValue,
1060                        LValue lvalue)
1061       : CGF(CGF), Data(OpaqueValueMappingData::bind(CGF, opaqueValue, lvalue)) {
1062     }
1063 
1064     OpaqueValueMapping(CodeGenFunction &CGF,
1065                        const OpaqueValueExpr *opaqueValue,
1066                        RValue rvalue)
1067       : CGF(CGF), Data(OpaqueValueMappingData::bind(CGF, opaqueValue, rvalue)) {
1068     }
1069 
1070     void pop() {
1071       Data.unbind(CGF);
1072       Data.clear();
1073     }
1074 
1075     ~OpaqueValueMapping() {
1076       if (Data.isValid()) Data.unbind(CGF);
1077     }
1078   };
1079 
1080 private:
1081   CGDebugInfo *DebugInfo;
1082   bool DisableDebugInfo;
1083 
1084   /// DidCallStackSave - Whether llvm.stacksave has been called. Used to avoid
1085   /// calling llvm.stacksave for multiple VLAs in the same scope.
1086   bool DidCallStackSave;
1087 
1088   /// IndirectBranch - The first time an indirect goto is seen we create a block
1089   /// with an indirect branch.  Every time we see the address of a label taken,
1090   /// we add the label to the indirect goto.  Every subsequent indirect goto is
1091   /// codegen'd as a jump to the IndirectBranch's basic block.
1092   llvm::IndirectBrInst *IndirectBranch;
1093 
1094   /// LocalDeclMap - This keeps track of the LLVM allocas or globals for local C
1095   /// decls.
1096   DeclMapTy LocalDeclMap;
1097 
1098   /// SizeArguments - If a ParmVarDecl had the pass_object_size attribute, this
1099   /// will contain a mapping from said ParmVarDecl to its implicit "object_size"
1100   /// parameter.
1101   llvm::SmallDenseMap<const ParmVarDecl *, const ImplicitParamDecl *, 2>
1102       SizeArguments;
1103 
1104   /// Track escaped local variables with auto storage. Used during SEH
1105   /// outlining to produce a call to llvm.localescape.
1106   llvm::DenseMap<llvm::AllocaInst *, int> EscapedLocals;
1107 
1108   /// LabelMap - This keeps track of the LLVM basic block for each C label.
1109   llvm::DenseMap<const LabelDecl*, JumpDest> LabelMap;
1110 
1111   // BreakContinueStack - This keeps track of where break and continue
1112   // statements should jump to.
1113   struct BreakContinue {
1114     BreakContinue(JumpDest Break, JumpDest Continue)
1115       : BreakBlock(Break), ContinueBlock(Continue) {}
1116 
1117     JumpDest BreakBlock;
1118     JumpDest ContinueBlock;
1119   };
1120   SmallVector<BreakContinue, 8> BreakContinueStack;
1121 
1122   /// Handles cancellation exit points in OpenMP-related constructs.
1123   class OpenMPCancelExitStack {
1124     /// Tracks cancellation exit point and join point for cancel-related exit
1125     /// and normal exit.
1126     struct CancelExit {
1127       CancelExit() = default;
1128       CancelExit(OpenMPDirectiveKind Kind, JumpDest ExitBlock,
1129                  JumpDest ContBlock)
1130           : Kind(Kind), ExitBlock(ExitBlock), ContBlock(ContBlock) {}
1131       OpenMPDirectiveKind Kind = OMPD_unknown;
1132       /// true if the exit block has been emitted already by the special
1133       /// emitExit() call, false if the default codegen is used.
1134       bool HasBeenEmitted = false;
1135       JumpDest ExitBlock;
1136       JumpDest ContBlock;
1137     };
1138 
1139     SmallVector<CancelExit, 8> Stack;
1140 
1141   public:
1142     OpenMPCancelExitStack() : Stack(1) {}
1143     ~OpenMPCancelExitStack() = default;
1144     /// Fetches the exit block for the current OpenMP construct.
1145     JumpDest getExitBlock() const { return Stack.back().ExitBlock; }
1146     /// Emits exit block with special codegen procedure specific for the related
1147     /// OpenMP construct + emits code for normal construct cleanup.
1148     void emitExit(CodeGenFunction &CGF, OpenMPDirectiveKind Kind,
1149                   const llvm::function_ref<void(CodeGenFunction &)> CodeGen) {
1150       if (Stack.back().Kind == Kind && getExitBlock().isValid()) {
1151         assert(CGF.getOMPCancelDestination(Kind).isValid());
1152         assert(CGF.HaveInsertPoint());
1153         assert(!Stack.back().HasBeenEmitted);
1154         auto IP = CGF.Builder.saveAndClearIP();
1155         CGF.EmitBlock(Stack.back().ExitBlock.getBlock());
1156         CodeGen(CGF);
1157         CGF.EmitBranch(Stack.back().ContBlock.getBlock());
1158         CGF.Builder.restoreIP(IP);
1159         Stack.back().HasBeenEmitted = true;
1160       }
1161       CodeGen(CGF);
1162     }
1163     /// Enter the cancel supporting \a Kind construct.
1164     /// \param Kind OpenMP directive that supports cancel constructs.
1165     /// \param HasCancel true, if the construct has inner cancel directive,
1166     /// false otherwise.
1167     void enter(CodeGenFunction &CGF, OpenMPDirectiveKind Kind, bool HasCancel) {
1168       Stack.push_back({Kind,
1169                        HasCancel ? CGF.getJumpDestInCurrentScope("cancel.exit")
1170                                  : JumpDest(),
1171                        HasCancel ? CGF.getJumpDestInCurrentScope("cancel.cont")
1172                                  : JumpDest()});
1173     }
1174     /// Emits default exit point for the cancel construct (if the special one
1175     /// has not be used) + join point for cancel/normal exits.
1176     void exit(CodeGenFunction &CGF) {
1177       if (getExitBlock().isValid()) {
1178         assert(CGF.getOMPCancelDestination(Stack.back().Kind).isValid());
1179         bool HaveIP = CGF.HaveInsertPoint();
1180         if (!Stack.back().HasBeenEmitted) {
1181           if (HaveIP)
1182             CGF.EmitBranchThroughCleanup(Stack.back().ContBlock);
1183           CGF.EmitBlock(Stack.back().ExitBlock.getBlock());
1184           CGF.EmitBranchThroughCleanup(Stack.back().ContBlock);
1185         }
1186         CGF.EmitBlock(Stack.back().ContBlock.getBlock());
1187         if (!HaveIP) {
1188           CGF.Builder.CreateUnreachable();
1189           CGF.Builder.ClearInsertionPoint();
1190         }
1191       }
1192       Stack.pop_back();
1193     }
1194   };
1195   OpenMPCancelExitStack OMPCancelStack;
1196 
1197   CodeGenPGO PGO;
1198 
1199   /// Calculate branch weights appropriate for PGO data
1200   llvm::MDNode *createProfileWeights(uint64_t TrueCount, uint64_t FalseCount);
1201   llvm::MDNode *createProfileWeights(ArrayRef<uint64_t> Weights);
1202   llvm::MDNode *createProfileWeightsForLoop(const Stmt *Cond,
1203                                             uint64_t LoopCount);
1204 
1205 public:
1206   /// Increment the profiler's counter for the given statement by \p StepV.
1207   /// If \p StepV is null, the default increment is 1.
1208   void incrementProfileCounter(const Stmt *S, llvm::Value *StepV = nullptr) {
1209     if (CGM.getCodeGenOpts().hasProfileClangInstr())
1210       PGO.emitCounterIncrement(Builder, S, StepV);
1211     PGO.setCurrentStmt(S);
1212   }
1213 
1214   /// Get the profiler's count for the given statement.
1215   uint64_t getProfileCount(const Stmt *S) {
1216     Optional<uint64_t> Count = PGO.getStmtCount(S);
1217     if (!Count.hasValue())
1218       return 0;
1219     return *Count;
1220   }
1221 
1222   /// Set the profiler's current count.
1223   void setCurrentProfileCount(uint64_t Count) {
1224     PGO.setCurrentRegionCount(Count);
1225   }
1226 
1227   /// Get the profiler's current count. This is generally the count for the most
1228   /// recently incremented counter.
1229   uint64_t getCurrentProfileCount() {
1230     return PGO.getCurrentRegionCount();
1231   }
1232 
1233 private:
1234 
1235   /// SwitchInsn - This is nearest current switch instruction. It is null if
1236   /// current context is not in a switch.
1237   llvm::SwitchInst *SwitchInsn;
1238   /// The branch weights of SwitchInsn when doing instrumentation based PGO.
1239   SmallVector<uint64_t, 16> *SwitchWeights;
1240 
1241   /// CaseRangeBlock - This block holds if condition check for last case
1242   /// statement range in current switch instruction.
1243   llvm::BasicBlock *CaseRangeBlock;
1244 
1245   /// OpaqueLValues - Keeps track of the current set of opaque value
1246   /// expressions.
1247   llvm::DenseMap<const OpaqueValueExpr *, LValue> OpaqueLValues;
1248   llvm::DenseMap<const OpaqueValueExpr *, RValue> OpaqueRValues;
1249 
1250   // VLASizeMap - This keeps track of the associated size for each VLA type.
1251   // We track this by the size expression rather than the type itself because
1252   // in certain situations, like a const qualifier applied to an VLA typedef,
1253   // multiple VLA types can share the same size expression.
1254   // FIXME: Maybe this could be a stack of maps that is pushed/popped as we
1255   // enter/leave scopes.
1256   llvm::DenseMap<const Expr*, llvm::Value*> VLASizeMap;
1257 
1258   /// A block containing a single 'unreachable' instruction.  Created
1259   /// lazily by getUnreachableBlock().
1260   llvm::BasicBlock *UnreachableBlock;
1261 
1262   /// Counts of the number return expressions in the function.
1263   unsigned NumReturnExprs;
1264 
1265   /// Count the number of simple (constant) return expressions in the function.
1266   unsigned NumSimpleReturnExprs;
1267 
1268   /// The last regular (non-return) debug location (breakpoint) in the function.
1269   SourceLocation LastStopPoint;
1270 
1271 public:
1272   /// A scope within which we are constructing the fields of an object which
1273   /// might use a CXXDefaultInitExpr. This stashes away a 'this' value to use
1274   /// if we need to evaluate a CXXDefaultInitExpr within the evaluation.
1275   class FieldConstructionScope {
1276   public:
1277     FieldConstructionScope(CodeGenFunction &CGF, Address This)
1278         : CGF(CGF), OldCXXDefaultInitExprThis(CGF.CXXDefaultInitExprThis) {
1279       CGF.CXXDefaultInitExprThis = This;
1280     }
1281     ~FieldConstructionScope() {
1282       CGF.CXXDefaultInitExprThis = OldCXXDefaultInitExprThis;
1283     }
1284 
1285   private:
1286     CodeGenFunction &CGF;
1287     Address OldCXXDefaultInitExprThis;
1288   };
1289 
1290   /// The scope of a CXXDefaultInitExpr. Within this scope, the value of 'this'
1291   /// is overridden to be the object under construction.
1292   class CXXDefaultInitExprScope {
1293   public:
1294     CXXDefaultInitExprScope(CodeGenFunction &CGF)
1295       : CGF(CGF), OldCXXThisValue(CGF.CXXThisValue),
1296         OldCXXThisAlignment(CGF.CXXThisAlignment) {
1297       CGF.CXXThisValue = CGF.CXXDefaultInitExprThis.getPointer();
1298       CGF.CXXThisAlignment = CGF.CXXDefaultInitExprThis.getAlignment();
1299     }
1300     ~CXXDefaultInitExprScope() {
1301       CGF.CXXThisValue = OldCXXThisValue;
1302       CGF.CXXThisAlignment = OldCXXThisAlignment;
1303     }
1304 
1305   public:
1306     CodeGenFunction &CGF;
1307     llvm::Value *OldCXXThisValue;
1308     CharUnits OldCXXThisAlignment;
1309   };
1310 
1311   /// The scope of an ArrayInitLoopExpr. Within this scope, the value of the
1312   /// current loop index is overridden.
1313   class ArrayInitLoopExprScope {
1314   public:
1315     ArrayInitLoopExprScope(CodeGenFunction &CGF, llvm::Value *Index)
1316       : CGF(CGF), OldArrayInitIndex(CGF.ArrayInitIndex) {
1317       CGF.ArrayInitIndex = Index;
1318     }
1319     ~ArrayInitLoopExprScope() {
1320       CGF.ArrayInitIndex = OldArrayInitIndex;
1321     }
1322 
1323   private:
1324     CodeGenFunction &CGF;
1325     llvm::Value *OldArrayInitIndex;
1326   };
1327 
1328   class InlinedInheritingConstructorScope {
1329   public:
1330     InlinedInheritingConstructorScope(CodeGenFunction &CGF, GlobalDecl GD)
1331         : CGF(CGF), OldCurGD(CGF.CurGD), OldCurFuncDecl(CGF.CurFuncDecl),
1332           OldCurCodeDecl(CGF.CurCodeDecl),
1333           OldCXXABIThisDecl(CGF.CXXABIThisDecl),
1334           OldCXXABIThisValue(CGF.CXXABIThisValue),
1335           OldCXXThisValue(CGF.CXXThisValue),
1336           OldCXXABIThisAlignment(CGF.CXXABIThisAlignment),
1337           OldCXXThisAlignment(CGF.CXXThisAlignment),
1338           OldReturnValue(CGF.ReturnValue), OldFnRetTy(CGF.FnRetTy),
1339           OldCXXInheritedCtorInitExprArgs(
1340               std::move(CGF.CXXInheritedCtorInitExprArgs)) {
1341       CGF.CurGD = GD;
1342       CGF.CurFuncDecl = CGF.CurCodeDecl =
1343           cast<CXXConstructorDecl>(GD.getDecl());
1344       CGF.CXXABIThisDecl = nullptr;
1345       CGF.CXXABIThisValue = nullptr;
1346       CGF.CXXThisValue = nullptr;
1347       CGF.CXXABIThisAlignment = CharUnits();
1348       CGF.CXXThisAlignment = CharUnits();
1349       CGF.ReturnValue = Address::invalid();
1350       CGF.FnRetTy = QualType();
1351       CGF.CXXInheritedCtorInitExprArgs.clear();
1352     }
1353     ~InlinedInheritingConstructorScope() {
1354       CGF.CurGD = OldCurGD;
1355       CGF.CurFuncDecl = OldCurFuncDecl;
1356       CGF.CurCodeDecl = OldCurCodeDecl;
1357       CGF.CXXABIThisDecl = OldCXXABIThisDecl;
1358       CGF.CXXABIThisValue = OldCXXABIThisValue;
1359       CGF.CXXThisValue = OldCXXThisValue;
1360       CGF.CXXABIThisAlignment = OldCXXABIThisAlignment;
1361       CGF.CXXThisAlignment = OldCXXThisAlignment;
1362       CGF.ReturnValue = OldReturnValue;
1363       CGF.FnRetTy = OldFnRetTy;
1364       CGF.CXXInheritedCtorInitExprArgs =
1365           std::move(OldCXXInheritedCtorInitExprArgs);
1366     }
1367 
1368   private:
1369     CodeGenFunction &CGF;
1370     GlobalDecl OldCurGD;
1371     const Decl *OldCurFuncDecl;
1372     const Decl *OldCurCodeDecl;
1373     ImplicitParamDecl *OldCXXABIThisDecl;
1374     llvm::Value *OldCXXABIThisValue;
1375     llvm::Value *OldCXXThisValue;
1376     CharUnits OldCXXABIThisAlignment;
1377     CharUnits OldCXXThisAlignment;
1378     Address OldReturnValue;
1379     QualType OldFnRetTy;
1380     CallArgList OldCXXInheritedCtorInitExprArgs;
1381   };
1382 
1383 private:
1384   /// CXXThisDecl - When generating code for a C++ member function,
1385   /// this will hold the implicit 'this' declaration.
1386   ImplicitParamDecl *CXXABIThisDecl;
1387   llvm::Value *CXXABIThisValue;
1388   llvm::Value *CXXThisValue;
1389   CharUnits CXXABIThisAlignment;
1390   CharUnits CXXThisAlignment;
1391 
1392   /// The value of 'this' to use when evaluating CXXDefaultInitExprs within
1393   /// this expression.
1394   Address CXXDefaultInitExprThis = Address::invalid();
1395 
1396   /// The current array initialization index when evaluating an
1397   /// ArrayInitIndexExpr within an ArrayInitLoopExpr.
1398   llvm::Value *ArrayInitIndex = nullptr;
1399 
1400   /// The values of function arguments to use when evaluating
1401   /// CXXInheritedCtorInitExprs within this context.
1402   CallArgList CXXInheritedCtorInitExprArgs;
1403 
1404   /// CXXStructorImplicitParamDecl - When generating code for a constructor or
1405   /// destructor, this will hold the implicit argument (e.g. VTT).
1406   ImplicitParamDecl *CXXStructorImplicitParamDecl;
1407   llvm::Value *CXXStructorImplicitParamValue;
1408 
1409   /// OutermostConditional - Points to the outermost active
1410   /// conditional control.  This is used so that we know if a
1411   /// temporary should be destroyed conditionally.
1412   ConditionalEvaluation *OutermostConditional;
1413 
1414   /// The current lexical scope.
1415   LexicalScope *CurLexicalScope;
1416 
1417   /// The current source location that should be used for exception
1418   /// handling code.
1419   SourceLocation CurEHLocation;
1420 
1421   /// BlockByrefInfos - For each __block variable, contains
1422   /// information about the layout of the variable.
1423   llvm::DenseMap<const ValueDecl *, BlockByrefInfo> BlockByrefInfos;
1424 
1425   /// Used by -fsanitize=nullability-return to determine whether the return
1426   /// value can be checked.
1427   llvm::Value *RetValNullabilityPrecondition = nullptr;
1428 
1429   /// Check if -fsanitize=nullability-return instrumentation is required for
1430   /// this function.
1431   bool requiresReturnValueNullabilityCheck() const {
1432     return RetValNullabilityPrecondition;
1433   }
1434 
1435   /// Used to store precise source locations for return statements by the
1436   /// runtime return value checks.
1437   Address ReturnLocation = Address::invalid();
1438 
1439   /// Check if the return value of this function requires sanitization.
1440   bool requiresReturnValueCheck() const {
1441     return requiresReturnValueNullabilityCheck() ||
1442            (SanOpts.has(SanitizerKind::ReturnsNonnullAttribute) &&
1443             CurCodeDecl && CurCodeDecl->getAttr<ReturnsNonNullAttr>());
1444   }
1445 
1446   llvm::BasicBlock *TerminateLandingPad;
1447   llvm::BasicBlock *TerminateHandler;
1448   llvm::BasicBlock *TrapBB;
1449 
1450   /// Terminate funclets keyed by parent funclet pad.
1451   llvm::MapVector<llvm::Value *, llvm::BasicBlock *> TerminateFunclets;
1452 
1453   /// True if we need emit the life-time markers.
1454   const bool ShouldEmitLifetimeMarkers;
1455 
1456   /// Add OpenCL kernel arg metadata and the kernel attribute metadata to
1457   /// the function metadata.
1458   void EmitOpenCLKernelMetadata(const FunctionDecl *FD,
1459                                 llvm::Function *Fn);
1460 
1461 public:
1462   CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext=false);
1463   ~CodeGenFunction();
1464 
1465   CodeGenTypes &getTypes() const { return CGM.getTypes(); }
1466   ASTContext &getContext() const { return CGM.getContext(); }
1467   CGDebugInfo *getDebugInfo() {
1468     if (DisableDebugInfo)
1469       return nullptr;
1470     return DebugInfo;
1471   }
1472   void disableDebugInfo() { DisableDebugInfo = true; }
1473   void enableDebugInfo() { DisableDebugInfo = false; }
1474 
1475   bool shouldUseFusedARCCalls() {
1476     return CGM.getCodeGenOpts().OptimizationLevel == 0;
1477   }
1478 
1479   const LangOptions &getLangOpts() const { return CGM.getLangOpts(); }
1480 
1481   /// Returns a pointer to the function's exception object and selector slot,
1482   /// which is assigned in every landing pad.
1483   Address getExceptionSlot();
1484   Address getEHSelectorSlot();
1485 
1486   /// Returns the contents of the function's exception object and selector
1487   /// slots.
1488   llvm::Value *getExceptionFromSlot();
1489   llvm::Value *getSelectorFromSlot();
1490 
1491   Address getNormalCleanupDestSlot();
1492 
1493   llvm::BasicBlock *getUnreachableBlock() {
1494     if (!UnreachableBlock) {
1495       UnreachableBlock = createBasicBlock("unreachable");
1496       new llvm::UnreachableInst(getLLVMContext(), UnreachableBlock);
1497     }
1498     return UnreachableBlock;
1499   }
1500 
1501   llvm::BasicBlock *getInvokeDest() {
1502     if (!EHStack.requiresLandingPad()) return nullptr;
1503     return getInvokeDestImpl();
1504   }
1505 
1506   bool currentFunctionUsesSEHTry() const { return CurSEHParent != nullptr; }
1507 
1508   const TargetInfo &getTarget() const { return Target; }
1509   llvm::LLVMContext &getLLVMContext() { return CGM.getLLVMContext(); }
1510   const TargetCodeGenInfo &getTargetHooks() const {
1511     return CGM.getTargetCodeGenInfo();
1512   }
1513 
1514   //===--------------------------------------------------------------------===//
1515   //                                  Cleanups
1516   //===--------------------------------------------------------------------===//
1517 
1518   typedef void Destroyer(CodeGenFunction &CGF, Address addr, QualType ty);
1519 
1520   void pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin,
1521                                         Address arrayEndPointer,
1522                                         QualType elementType,
1523                                         CharUnits elementAlignment,
1524                                         Destroyer *destroyer);
1525   void pushRegularPartialArrayCleanup(llvm::Value *arrayBegin,
1526                                       llvm::Value *arrayEnd,
1527                                       QualType elementType,
1528                                       CharUnits elementAlignment,
1529                                       Destroyer *destroyer);
1530 
1531   void pushDestroy(QualType::DestructionKind dtorKind,
1532                    Address addr, QualType type);
1533   void pushEHDestroy(QualType::DestructionKind dtorKind,
1534                      Address addr, QualType type);
1535   void pushDestroy(CleanupKind kind, Address addr, QualType type,
1536                    Destroyer *destroyer, bool useEHCleanupForArray);
1537   void pushLifetimeExtendedDestroy(CleanupKind kind, Address addr,
1538                                    QualType type, Destroyer *destroyer,
1539                                    bool useEHCleanupForArray);
1540   void pushCallObjectDeleteCleanup(const FunctionDecl *OperatorDelete,
1541                                    llvm::Value *CompletePtr,
1542                                    QualType ElementType);
1543   void pushStackRestore(CleanupKind kind, Address SPMem);
1544   void emitDestroy(Address addr, QualType type, Destroyer *destroyer,
1545                    bool useEHCleanupForArray);
1546   llvm::Function *generateDestroyHelper(Address addr, QualType type,
1547                                         Destroyer *destroyer,
1548                                         bool useEHCleanupForArray,
1549                                         const VarDecl *VD);
1550   void emitArrayDestroy(llvm::Value *begin, llvm::Value *end,
1551                         QualType elementType, CharUnits elementAlign,
1552                         Destroyer *destroyer,
1553                         bool checkZeroLength, bool useEHCleanup);
1554 
1555   Destroyer *getDestroyer(QualType::DestructionKind destructionKind);
1556 
1557   /// Determines whether an EH cleanup is required to destroy a type
1558   /// with the given destruction kind.
1559   bool needsEHCleanup(QualType::DestructionKind kind) {
1560     switch (kind) {
1561     case QualType::DK_none:
1562       return false;
1563     case QualType::DK_cxx_destructor:
1564     case QualType::DK_objc_weak_lifetime:
1565     case QualType::DK_nontrivial_c_struct:
1566       return getLangOpts().Exceptions;
1567     case QualType::DK_objc_strong_lifetime:
1568       return getLangOpts().Exceptions &&
1569              CGM.getCodeGenOpts().ObjCAutoRefCountExceptions;
1570     }
1571     llvm_unreachable("bad destruction kind");
1572   }
1573 
1574   CleanupKind getCleanupKind(QualType::DestructionKind kind) {
1575     return (needsEHCleanup(kind) ? NormalAndEHCleanup : NormalCleanup);
1576   }
1577 
1578   //===--------------------------------------------------------------------===//
1579   //                                  Objective-C
1580   //===--------------------------------------------------------------------===//
1581 
1582   void GenerateObjCMethod(const ObjCMethodDecl *OMD);
1583 
1584   void StartObjCMethod(const ObjCMethodDecl *MD, const ObjCContainerDecl *CD);
1585 
1586   /// GenerateObjCGetter - Synthesize an Objective-C property getter function.
1587   void GenerateObjCGetter(ObjCImplementationDecl *IMP,
1588                           const ObjCPropertyImplDecl *PID);
1589   void generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
1590                               const ObjCPropertyImplDecl *propImpl,
1591                               const ObjCMethodDecl *GetterMothodDecl,
1592                               llvm::Constant *AtomicHelperFn);
1593 
1594   void GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP,
1595                                   ObjCMethodDecl *MD, bool ctor);
1596 
1597   /// GenerateObjCSetter - Synthesize an Objective-C property setter function
1598   /// for the given property.
1599   void GenerateObjCSetter(ObjCImplementationDecl *IMP,
1600                           const ObjCPropertyImplDecl *PID);
1601   void generateObjCSetterBody(const ObjCImplementationDecl *classImpl,
1602                               const ObjCPropertyImplDecl *propImpl,
1603                               llvm::Constant *AtomicHelperFn);
1604 
1605   //===--------------------------------------------------------------------===//
1606   //                                  Block Bits
1607   //===--------------------------------------------------------------------===//
1608 
1609   /// Emit block literal.
1610   /// \return an LLVM value which is a pointer to a struct which contains
1611   /// information about the block, including the block invoke function, the
1612   /// captured variables, etc.
1613   llvm::Value *EmitBlockLiteral(const BlockExpr *);
1614   static void destroyBlockInfos(CGBlockInfo *info);
1615 
1616   llvm::Function *GenerateBlockFunction(GlobalDecl GD,
1617                                         const CGBlockInfo &Info,
1618                                         const DeclMapTy &ldm,
1619                                         bool IsLambdaConversionToBlock,
1620                                         bool BuildGlobalBlock);
1621 
1622   llvm::Constant *GenerateCopyHelperFunction(const CGBlockInfo &blockInfo);
1623   llvm::Constant *GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo);
1624   llvm::Constant *GenerateObjCAtomicSetterCopyHelperFunction(
1625                                              const ObjCPropertyImplDecl *PID);
1626   llvm::Constant *GenerateObjCAtomicGetterCopyHelperFunction(
1627                                              const ObjCPropertyImplDecl *PID);
1628   llvm::Value *EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty);
1629 
1630   void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags);
1631 
1632   class AutoVarEmission;
1633 
1634   void emitByrefStructureInit(const AutoVarEmission &emission);
1635   void enterByrefCleanup(const AutoVarEmission &emission);
1636 
1637   void setBlockContextParameter(const ImplicitParamDecl *D, unsigned argNum,
1638                                 llvm::Value *ptr);
1639 
1640   Address LoadBlockStruct();
1641   Address GetAddrOfBlockDecl(const VarDecl *var, bool ByRef);
1642 
1643   /// BuildBlockByrefAddress - Computes the location of the
1644   /// data in a variable which is declared as __block.
1645   Address emitBlockByrefAddress(Address baseAddr, const VarDecl *V,
1646                                 bool followForward = true);
1647   Address emitBlockByrefAddress(Address baseAddr,
1648                                 const BlockByrefInfo &info,
1649                                 bool followForward,
1650                                 const llvm::Twine &name);
1651 
1652   const BlockByrefInfo &getBlockByrefInfo(const VarDecl *var);
1653 
1654   QualType BuildFunctionArgList(GlobalDecl GD, FunctionArgList &Args);
1655 
1656   void GenerateCode(GlobalDecl GD, llvm::Function *Fn,
1657                     const CGFunctionInfo &FnInfo);
1658   /// \brief Emit code for the start of a function.
1659   /// \param Loc       The location to be associated with the function.
1660   /// \param StartLoc  The location of the function body.
1661   void StartFunction(GlobalDecl GD,
1662                      QualType RetTy,
1663                      llvm::Function *Fn,
1664                      const CGFunctionInfo &FnInfo,
1665                      const FunctionArgList &Args,
1666                      SourceLocation Loc = SourceLocation(),
1667                      SourceLocation StartLoc = SourceLocation());
1668 
1669   static bool IsConstructorDelegationValid(const CXXConstructorDecl *Ctor);
1670 
1671   void EmitConstructorBody(FunctionArgList &Args);
1672   void EmitDestructorBody(FunctionArgList &Args);
1673   void emitImplicitAssignmentOperatorBody(FunctionArgList &Args);
1674   void EmitFunctionBody(FunctionArgList &Args, const Stmt *Body);
1675   void EmitBlockWithFallThrough(llvm::BasicBlock *BB, const Stmt *S);
1676 
1677   void EmitForwardingCallToLambda(const CXXMethodDecl *LambdaCallOperator,
1678                                   CallArgList &CallArgs);
1679   void EmitLambdaBlockInvokeBody();
1680   void EmitLambdaDelegatingInvokeBody(const CXXMethodDecl *MD);
1681   void EmitLambdaStaticInvokeBody(const CXXMethodDecl *MD);
1682   void EmitAsanPrologueOrEpilogue(bool Prologue);
1683 
1684   /// \brief Emit the unified return block, trying to avoid its emission when
1685   /// possible.
1686   /// \return The debug location of the user written return statement if the
1687   /// return block is is avoided.
1688   llvm::DebugLoc EmitReturnBlock();
1689 
1690   /// FinishFunction - Complete IR generation of the current function. It is
1691   /// legal to call this function even if there is no current insertion point.
1692   void FinishFunction(SourceLocation EndLoc=SourceLocation());
1693 
1694   void StartThunk(llvm::Function *Fn, GlobalDecl GD,
1695                   const CGFunctionInfo &FnInfo, bool IsUnprototyped);
1696 
1697   void EmitCallAndReturnForThunk(llvm::Constant *Callee, const ThunkInfo *Thunk,
1698                                  bool IsUnprototyped);
1699 
1700   void FinishThunk();
1701 
1702   /// Emit a musttail call for a thunk with a potentially adjusted this pointer.
1703   void EmitMustTailThunk(const CXXMethodDecl *MD, llvm::Value *AdjustedThisPtr,
1704                          llvm::Value *Callee);
1705 
1706   /// Generate a thunk for the given method.
1707   void generateThunk(llvm::Function *Fn, const CGFunctionInfo &FnInfo,
1708                      GlobalDecl GD, const ThunkInfo &Thunk,
1709                      bool IsUnprototyped);
1710 
1711   llvm::Function *GenerateVarArgsThunk(llvm::Function *Fn,
1712                                        const CGFunctionInfo &FnInfo,
1713                                        GlobalDecl GD, const ThunkInfo &Thunk);
1714 
1715   void EmitCtorPrologue(const CXXConstructorDecl *CD, CXXCtorType Type,
1716                         FunctionArgList &Args);
1717 
1718   void EmitInitializerForField(FieldDecl *Field, LValue LHS, Expr *Init);
1719 
1720   /// Struct with all information about dynamic [sub]class needed to set vptr.
1721   struct VPtr {
1722     BaseSubobject Base;
1723     const CXXRecordDecl *NearestVBase;
1724     CharUnits OffsetFromNearestVBase;
1725     const CXXRecordDecl *VTableClass;
1726   };
1727 
1728   /// Initialize the vtable pointer of the given subobject.
1729   void InitializeVTablePointer(const VPtr &vptr);
1730 
1731   typedef llvm::SmallVector<VPtr, 4> VPtrsVector;
1732 
1733   typedef llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBasesSetTy;
1734   VPtrsVector getVTablePointers(const CXXRecordDecl *VTableClass);
1735 
1736   void getVTablePointers(BaseSubobject Base, const CXXRecordDecl *NearestVBase,
1737                          CharUnits OffsetFromNearestVBase,
1738                          bool BaseIsNonVirtualPrimaryBase,
1739                          const CXXRecordDecl *VTableClass,
1740                          VisitedVirtualBasesSetTy &VBases, VPtrsVector &vptrs);
1741 
1742   void InitializeVTablePointers(const CXXRecordDecl *ClassDecl);
1743 
1744   /// GetVTablePtr - Return the Value of the vtable pointer member pointed
1745   /// to by This.
1746   llvm::Value *GetVTablePtr(Address This, llvm::Type *VTableTy,
1747                             const CXXRecordDecl *VTableClass);
1748 
1749   enum CFITypeCheckKind {
1750     CFITCK_VCall,
1751     CFITCK_NVCall,
1752     CFITCK_DerivedCast,
1753     CFITCK_UnrelatedCast,
1754     CFITCK_ICall,
1755   };
1756 
1757   /// \brief Derived is the presumed address of an object of type T after a
1758   /// cast. If T is a polymorphic class type, emit a check that the virtual
1759   /// table for Derived belongs to a class derived from T.
1760   void EmitVTablePtrCheckForCast(QualType T, llvm::Value *Derived,
1761                                  bool MayBeNull, CFITypeCheckKind TCK,
1762                                  SourceLocation Loc);
1763 
1764   /// EmitVTablePtrCheckForCall - Virtual method MD is being called via VTable.
1765   /// If vptr CFI is enabled, emit a check that VTable is valid.
1766   void EmitVTablePtrCheckForCall(const CXXRecordDecl *RD, llvm::Value *VTable,
1767                                  CFITypeCheckKind TCK, SourceLocation Loc);
1768 
1769   /// EmitVTablePtrCheck - Emit a check that VTable is a valid virtual table for
1770   /// RD using llvm.type.test.
1771   void EmitVTablePtrCheck(const CXXRecordDecl *RD, llvm::Value *VTable,
1772                           CFITypeCheckKind TCK, SourceLocation Loc);
1773 
1774   /// If whole-program virtual table optimization is enabled, emit an assumption
1775   /// that VTable is a member of RD's type identifier. Or, if vptr CFI is
1776   /// enabled, emit a check that VTable is a member of RD's type identifier.
1777   void EmitTypeMetadataCodeForVCall(const CXXRecordDecl *RD,
1778                                     llvm::Value *VTable, SourceLocation Loc);
1779 
1780   /// Returns whether we should perform a type checked load when loading a
1781   /// virtual function for virtual calls to members of RD. This is generally
1782   /// true when both vcall CFI and whole-program-vtables are enabled.
1783   bool ShouldEmitVTableTypeCheckedLoad(const CXXRecordDecl *RD);
1784 
1785   /// Emit a type checked load from the given vtable.
1786   llvm::Value *EmitVTableTypeCheckedLoad(const CXXRecordDecl *RD, llvm::Value *VTable,
1787                                          uint64_t VTableByteOffset);
1788 
1789   /// EnterDtorCleanups - Enter the cleanups necessary to complete the
1790   /// given phase of destruction for a destructor.  The end result
1791   /// should call destructors on members and base classes in reverse
1792   /// order of their construction.
1793   void EnterDtorCleanups(const CXXDestructorDecl *Dtor, CXXDtorType Type);
1794 
1795   /// ShouldInstrumentFunction - Return true if the current function should be
1796   /// instrumented with __cyg_profile_func_* calls
1797   bool ShouldInstrumentFunction();
1798 
1799   /// ShouldXRayInstrument - Return true if the current function should be
1800   /// instrumented with XRay nop sleds.
1801   bool ShouldXRayInstrumentFunction() const;
1802 
1803   /// AlwaysEmitXRayCustomEvents - Return true if we must unconditionally emit
1804   /// XRay custom event handling calls.
1805   bool AlwaysEmitXRayCustomEvents() const;
1806 
1807   /// AlwaysEmitXRayTypedEvents - Return true if clang must unconditionally emit
1808   /// XRay typed event handling calls.
1809   bool AlwaysEmitXRayTypedEvents() const;
1810 
1811   /// Encode an address into a form suitable for use in a function prologue.
1812   llvm::Constant *EncodeAddrForUseInPrologue(llvm::Function *F,
1813                                              llvm::Constant *Addr);
1814 
1815   /// Decode an address used in a function prologue, encoded by \c
1816   /// EncodeAddrForUseInPrologue.
1817   llvm::Value *DecodeAddrUsedInPrologue(llvm::Value *F,
1818                                         llvm::Value *EncodedAddr);
1819 
1820   /// EmitFunctionProlog - Emit the target specific LLVM code to load the
1821   /// arguments for the given function. This is also responsible for naming the
1822   /// LLVM function arguments.
1823   void EmitFunctionProlog(const CGFunctionInfo &FI,
1824                           llvm::Function *Fn,
1825                           const FunctionArgList &Args);
1826 
1827   /// EmitFunctionEpilog - Emit the target specific LLVM code to return the
1828   /// given temporary.
1829   void EmitFunctionEpilog(const CGFunctionInfo &FI, bool EmitRetDbgLoc,
1830                           SourceLocation EndLoc);
1831 
1832   /// Emit a test that checks if the return value \p RV is nonnull.
1833   void EmitReturnValueCheck(llvm::Value *RV);
1834 
1835   /// EmitStartEHSpec - Emit the start of the exception spec.
1836   void EmitStartEHSpec(const Decl *D);
1837 
1838   /// EmitEndEHSpec - Emit the end of the exception spec.
1839   void EmitEndEHSpec(const Decl *D);
1840 
1841   /// getTerminateLandingPad - Return a landing pad that just calls terminate.
1842   llvm::BasicBlock *getTerminateLandingPad();
1843 
1844   /// getTerminateLandingPad - Return a cleanup funclet that just calls
1845   /// terminate.
1846   llvm::BasicBlock *getTerminateFunclet();
1847 
1848   /// getTerminateHandler - Return a handler (not a landing pad, just
1849   /// a catch handler) that just calls terminate.  This is used when
1850   /// a terminate scope encloses a try.
1851   llvm::BasicBlock *getTerminateHandler();
1852 
1853   llvm::Type *ConvertTypeForMem(QualType T);
1854   llvm::Type *ConvertType(QualType T);
1855   llvm::Type *ConvertType(const TypeDecl *T) {
1856     return ConvertType(getContext().getTypeDeclType(T));
1857   }
1858 
1859   /// LoadObjCSelf - Load the value of self. This function is only valid while
1860   /// generating code for an Objective-C method.
1861   llvm::Value *LoadObjCSelf();
1862 
1863   /// TypeOfSelfObject - Return type of object that this self represents.
1864   QualType TypeOfSelfObject();
1865 
1866   /// getEvaluationKind - Return the TypeEvaluationKind of QualType \c T.
1867   static TypeEvaluationKind getEvaluationKind(QualType T);
1868 
1869   static bool hasScalarEvaluationKind(QualType T) {
1870     return getEvaluationKind(T) == TEK_Scalar;
1871   }
1872 
1873   static bool hasAggregateEvaluationKind(QualType T) {
1874     return getEvaluationKind(T) == TEK_Aggregate;
1875   }
1876 
1877   /// createBasicBlock - Create an LLVM basic block.
1878   llvm::BasicBlock *createBasicBlock(const Twine &name = "",
1879                                      llvm::Function *parent = nullptr,
1880                                      llvm::BasicBlock *before = nullptr) {
1881     return llvm::BasicBlock::Create(getLLVMContext(), name, parent, before);
1882   }
1883 
1884   /// getBasicBlockForLabel - Return the LLVM basicblock that the specified
1885   /// label maps to.
1886   JumpDest getJumpDestForLabel(const LabelDecl *S);
1887 
1888   /// SimplifyForwardingBlocks - If the given basic block is only a branch to
1889   /// another basic block, simplify it. This assumes that no other code could
1890   /// potentially reference the basic block.
1891   void SimplifyForwardingBlocks(llvm::BasicBlock *BB);
1892 
1893   /// EmitBlock - Emit the given block \arg BB and set it as the insert point,
1894   /// adding a fall-through branch from the current insert block if
1895   /// necessary. It is legal to call this function even if there is no current
1896   /// insertion point.
1897   ///
1898   /// IsFinished - If true, indicates that the caller has finished emitting
1899   /// branches to the given block and does not expect to emit code into it. This
1900   /// means the block can be ignored if it is unreachable.
1901   void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false);
1902 
1903   /// EmitBlockAfterUses - Emit the given block somewhere hopefully
1904   /// near its uses, and leave the insertion point in it.
1905   void EmitBlockAfterUses(llvm::BasicBlock *BB);
1906 
1907   /// EmitBranch - Emit a branch to the specified basic block from the current
1908   /// insert block, taking care to avoid creation of branches from dummy
1909   /// blocks. It is legal to call this function even if there is no current
1910   /// insertion point.
1911   ///
1912   /// This function clears the current insertion point. The caller should follow
1913   /// calls to this function with calls to Emit*Block prior to generation new
1914   /// code.
1915   void EmitBranch(llvm::BasicBlock *Block);
1916 
1917   /// HaveInsertPoint - True if an insertion point is defined. If not, this
1918   /// indicates that the current code being emitted is unreachable.
1919   bool HaveInsertPoint() const {
1920     return Builder.GetInsertBlock() != nullptr;
1921   }
1922 
1923   /// EnsureInsertPoint - Ensure that an insertion point is defined so that
1924   /// emitted IR has a place to go. Note that by definition, if this function
1925   /// creates a block then that block is unreachable; callers may do better to
1926   /// detect when no insertion point is defined and simply skip IR generation.
1927   void EnsureInsertPoint() {
1928     if (!HaveInsertPoint())
1929       EmitBlock(createBasicBlock());
1930   }
1931 
1932   /// ErrorUnsupported - Print out an error that codegen doesn't support the
1933   /// specified stmt yet.
1934   void ErrorUnsupported(const Stmt *S, const char *Type);
1935 
1936   //===--------------------------------------------------------------------===//
1937   //                                  Helpers
1938   //===--------------------------------------------------------------------===//
1939 
1940   LValue MakeAddrLValue(Address Addr, QualType T,
1941                         AlignmentSource Source = AlignmentSource::Type) {
1942     return LValue::MakeAddr(Addr, T, getContext(), LValueBaseInfo(Source),
1943                             CGM.getTBAAAccessInfo(T));
1944   }
1945 
1946   LValue MakeAddrLValue(Address Addr, QualType T, LValueBaseInfo BaseInfo,
1947                         TBAAAccessInfo TBAAInfo) {
1948     return LValue::MakeAddr(Addr, T, getContext(), BaseInfo, TBAAInfo);
1949   }
1950 
1951   LValue MakeAddrLValue(llvm::Value *V, QualType T, CharUnits Alignment,
1952                         AlignmentSource Source = AlignmentSource::Type) {
1953     return LValue::MakeAddr(Address(V, Alignment), T, getContext(),
1954                             LValueBaseInfo(Source), CGM.getTBAAAccessInfo(T));
1955   }
1956 
1957   LValue MakeAddrLValue(llvm::Value *V, QualType T, CharUnits Alignment,
1958                         LValueBaseInfo BaseInfo, TBAAAccessInfo TBAAInfo) {
1959     return LValue::MakeAddr(Address(V, Alignment), T, getContext(),
1960                             BaseInfo, TBAAInfo);
1961   }
1962 
1963   LValue MakeNaturalAlignPointeeAddrLValue(llvm::Value *V, QualType T);
1964   LValue MakeNaturalAlignAddrLValue(llvm::Value *V, QualType T);
1965   CharUnits getNaturalTypeAlignment(QualType T,
1966                                     LValueBaseInfo *BaseInfo = nullptr,
1967                                     TBAAAccessInfo *TBAAInfo = nullptr,
1968                                     bool forPointeeType = false);
1969   CharUnits getNaturalPointeeTypeAlignment(QualType T,
1970                                            LValueBaseInfo *BaseInfo = nullptr,
1971                                            TBAAAccessInfo *TBAAInfo = nullptr);
1972 
1973   Address EmitLoadOfReference(LValue RefLVal,
1974                               LValueBaseInfo *PointeeBaseInfo = nullptr,
1975                               TBAAAccessInfo *PointeeTBAAInfo = nullptr);
1976   LValue EmitLoadOfReferenceLValue(LValue RefLVal);
1977   LValue EmitLoadOfReferenceLValue(Address RefAddr, QualType RefTy,
1978                                    AlignmentSource Source =
1979                                        AlignmentSource::Type) {
1980     LValue RefLVal = MakeAddrLValue(RefAddr, RefTy, LValueBaseInfo(Source),
1981                                     CGM.getTBAAAccessInfo(RefTy));
1982     return EmitLoadOfReferenceLValue(RefLVal);
1983   }
1984 
1985   Address EmitLoadOfPointer(Address Ptr, const PointerType *PtrTy,
1986                             LValueBaseInfo *BaseInfo = nullptr,
1987                             TBAAAccessInfo *TBAAInfo = nullptr);
1988   LValue EmitLoadOfPointerLValue(Address Ptr, const PointerType *PtrTy);
1989 
1990   /// CreateTempAlloca - This creates an alloca and inserts it into the entry
1991   /// block if \p ArraySize is nullptr, otherwise inserts it at the current
1992   /// insertion point of the builder. The caller is responsible for setting an
1993   /// appropriate alignment on
1994   /// the alloca.
1995   ///
1996   /// \p ArraySize is the number of array elements to be allocated if it
1997   ///    is not nullptr.
1998   ///
1999   /// LangAS::Default is the address space of pointers to local variables and
2000   /// temporaries, as exposed in the source language. In certain
2001   /// configurations, this is not the same as the alloca address space, and a
2002   /// cast is needed to lift the pointer from the alloca AS into
2003   /// LangAS::Default. This can happen when the target uses a restricted
2004   /// address space for the stack but the source language requires
2005   /// LangAS::Default to be a generic address space. The latter condition is
2006   /// common for most programming languages; OpenCL is an exception in that
2007   /// LangAS::Default is the private address space, which naturally maps
2008   /// to the stack.
2009   ///
2010   /// Because the address of a temporary is often exposed to the program in
2011   /// various ways, this function will perform the cast by default. The cast
2012   /// may be avoided by passing false as \p CastToDefaultAddrSpace; this is
2013   /// more efficient if the caller knows that the address will not be exposed.
2014   llvm::AllocaInst *CreateTempAlloca(llvm::Type *Ty, const Twine &Name = "tmp",
2015                                      llvm::Value *ArraySize = nullptr);
2016   Address CreateTempAlloca(llvm::Type *Ty, CharUnits align,
2017                            const Twine &Name = "tmp",
2018                            llvm::Value *ArraySize = nullptr,
2019                            bool CastToDefaultAddrSpace = true);
2020 
2021   /// CreateDefaultAlignedTempAlloca - This creates an alloca with the
2022   /// default ABI alignment of the given LLVM type.
2023   ///
2024   /// IMPORTANT NOTE: This is *not* generally the right alignment for
2025   /// any given AST type that happens to have been lowered to the
2026   /// given IR type.  This should only ever be used for function-local,
2027   /// IR-driven manipulations like saving and restoring a value.  Do
2028   /// not hand this address off to arbitrary IRGen routines, and especially
2029   /// do not pass it as an argument to a function that might expect a
2030   /// properly ABI-aligned value.
2031   Address CreateDefaultAlignTempAlloca(llvm::Type *Ty,
2032                                        const Twine &Name = "tmp");
2033 
2034   /// InitTempAlloca - Provide an initial value for the given alloca which
2035   /// will be observable at all locations in the function.
2036   ///
2037   /// The address should be something that was returned from one of
2038   /// the CreateTempAlloca or CreateMemTemp routines, and the
2039   /// initializer must be valid in the entry block (i.e. it must
2040   /// either be a constant or an argument value).
2041   void InitTempAlloca(Address Alloca, llvm::Value *Value);
2042 
2043   /// CreateIRTemp - Create a temporary IR object of the given type, with
2044   /// appropriate alignment. This routine should only be used when an temporary
2045   /// value needs to be stored into an alloca (for example, to avoid explicit
2046   /// PHI construction), but the type is the IR type, not the type appropriate
2047   /// for storing in memory.
2048   ///
2049   /// That is, this is exactly equivalent to CreateMemTemp, but calling
2050   /// ConvertType instead of ConvertTypeForMem.
2051   Address CreateIRTemp(QualType T, const Twine &Name = "tmp");
2052 
2053   /// CreateMemTemp - Create a temporary memory object of the given type, with
2054   /// appropriate alignment. Cast it to the default address space if
2055   /// \p CastToDefaultAddrSpace is true.
2056   Address CreateMemTemp(QualType T, const Twine &Name = "tmp",
2057                         bool CastToDefaultAddrSpace = true);
2058   Address CreateMemTemp(QualType T, CharUnits Align, const Twine &Name = "tmp",
2059                         bool CastToDefaultAddrSpace = true);
2060 
2061   /// CreateAggTemp - Create a temporary memory object for the given
2062   /// aggregate type.
2063   AggValueSlot CreateAggTemp(QualType T, const Twine &Name = "tmp") {
2064     return AggValueSlot::forAddr(CreateMemTemp(T, Name),
2065                                  T.getQualifiers(),
2066                                  AggValueSlot::IsNotDestructed,
2067                                  AggValueSlot::DoesNotNeedGCBarriers,
2068                                  AggValueSlot::IsNotAliased,
2069                                  AggValueSlot::DoesNotOverlap);
2070   }
2071 
2072   /// Emit a cast to void* in the appropriate address space.
2073   llvm::Value *EmitCastToVoidPtr(llvm::Value *value);
2074 
2075   /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
2076   /// expression and compare the result against zero, returning an Int1Ty value.
2077   llvm::Value *EvaluateExprAsBool(const Expr *E);
2078 
2079   /// EmitIgnoredExpr - Emit an expression in a context which ignores the result.
2080   void EmitIgnoredExpr(const Expr *E);
2081 
2082   /// EmitAnyExpr - Emit code to compute the specified expression which can have
2083   /// any type.  The result is returned as an RValue struct.  If this is an
2084   /// aggregate expression, the aggloc/agglocvolatile arguments indicate where
2085   /// the result should be returned.
2086   ///
2087   /// \param ignoreResult True if the resulting value isn't used.
2088   RValue EmitAnyExpr(const Expr *E,
2089                      AggValueSlot aggSlot = AggValueSlot::ignored(),
2090                      bool ignoreResult = false);
2091 
2092   // EmitVAListRef - Emit a "reference" to a va_list; this is either the address
2093   // or the value of the expression, depending on how va_list is defined.
2094   Address EmitVAListRef(const Expr *E);
2095 
2096   /// Emit a "reference" to a __builtin_ms_va_list; this is
2097   /// always the value of the expression, because a __builtin_ms_va_list is a
2098   /// pointer to a char.
2099   Address EmitMSVAListRef(const Expr *E);
2100 
2101   /// EmitAnyExprToTemp - Similarly to EmitAnyExpr(), however, the result will
2102   /// always be accessible even if no aggregate location is provided.
2103   RValue EmitAnyExprToTemp(const Expr *E);
2104 
2105   /// EmitAnyExprToMem - Emits the code necessary to evaluate an
2106   /// arbitrary expression into the given memory location.
2107   void EmitAnyExprToMem(const Expr *E, Address Location,
2108                         Qualifiers Quals, bool IsInitializer);
2109 
2110   void EmitAnyExprToExn(const Expr *E, Address Addr);
2111 
2112   /// EmitExprAsInit - Emits the code necessary to initialize a
2113   /// location in memory with the given initializer.
2114   void EmitExprAsInit(const Expr *init, const ValueDecl *D, LValue lvalue,
2115                       bool capturedByInit);
2116 
2117   /// hasVolatileMember - returns true if aggregate type has a volatile
2118   /// member.
2119   bool hasVolatileMember(QualType T) {
2120     if (const RecordType *RT = T->getAs<RecordType>()) {
2121       const RecordDecl *RD = cast<RecordDecl>(RT->getDecl());
2122       return RD->hasVolatileMember();
2123     }
2124     return false;
2125   }
2126 
2127   /// Determine whether a return value slot may overlap some other object.
2128   AggValueSlot::Overlap_t overlapForReturnValue() {
2129     // FIXME: Assuming no overlap here breaks guaranteed copy elision for base
2130     // class subobjects. These cases may need to be revisited depending on the
2131     // resolution of the relevant core issue.
2132     return AggValueSlot::DoesNotOverlap;
2133   }
2134 
2135   /// Determine whether a field initialization may overlap some other object.
2136   AggValueSlot::Overlap_t overlapForFieldInit(const FieldDecl *FD) {
2137     // FIXME: These cases can result in overlap as a result of P0840R0's
2138     // [[no_unique_address]] attribute. We can still infer NoOverlap in the
2139     // presence of that attribute if the field is within the nvsize of its
2140     // containing class, because non-virtual subobjects are initialized in
2141     // address order.
2142     return AggValueSlot::DoesNotOverlap;
2143   }
2144 
2145   /// Determine whether a base class initialization may overlap some other
2146   /// object.
2147   AggValueSlot::Overlap_t overlapForBaseInit(const CXXRecordDecl *RD,
2148                                              const CXXRecordDecl *BaseRD,
2149                                              bool IsVirtual);
2150 
2151   /// Emit an aggregate assignment.
2152   void EmitAggregateAssign(LValue Dest, LValue Src, QualType EltTy) {
2153     bool IsVolatile = hasVolatileMember(EltTy);
2154     EmitAggregateCopy(Dest, Src, EltTy, AggValueSlot::MayOverlap, IsVolatile);
2155   }
2156 
2157   void EmitAggregateCopyCtor(LValue Dest, LValue Src,
2158                              AggValueSlot::Overlap_t MayOverlap) {
2159     EmitAggregateCopy(Dest, Src, Src.getType(), MayOverlap);
2160   }
2161 
2162   /// EmitAggregateCopy - Emit an aggregate copy.
2163   ///
2164   /// \param isVolatile \c true iff either the source or the destination is
2165   ///        volatile.
2166   /// \param MayOverlap Whether the tail padding of the destination might be
2167   ///        occupied by some other object. More efficient code can often be
2168   ///        generated if not.
2169   void EmitAggregateCopy(LValue Dest, LValue Src, QualType EltTy,
2170                          AggValueSlot::Overlap_t MayOverlap,
2171                          bool isVolatile = false);
2172 
2173   /// GetAddrOfLocalVar - Return the address of a local variable.
2174   Address GetAddrOfLocalVar(const VarDecl *VD) {
2175     auto it = LocalDeclMap.find(VD);
2176     assert(it != LocalDeclMap.end() &&
2177            "Invalid argument to GetAddrOfLocalVar(), no decl!");
2178     return it->second;
2179   }
2180 
2181   /// Given an opaque value expression, return its LValue mapping if it exists,
2182   /// otherwise create one.
2183   LValue getOrCreateOpaqueLValueMapping(const OpaqueValueExpr *e);
2184 
2185   /// Given an opaque value expression, return its RValue mapping if it exists,
2186   /// otherwise create one.
2187   RValue getOrCreateOpaqueRValueMapping(const OpaqueValueExpr *e);
2188 
2189   /// Get the index of the current ArrayInitLoopExpr, if any.
2190   llvm::Value *getArrayInitIndex() { return ArrayInitIndex; }
2191 
2192   /// getAccessedFieldNo - Given an encoded value and a result number, return
2193   /// the input field number being accessed.
2194   static unsigned getAccessedFieldNo(unsigned Idx, const llvm::Constant *Elts);
2195 
2196   llvm::BlockAddress *GetAddrOfLabel(const LabelDecl *L);
2197   llvm::BasicBlock *GetIndirectGotoBlock();
2198 
2199   /// Check if \p E is a C++ "this" pointer wrapped in value-preserving casts.
2200   static bool IsWrappedCXXThis(const Expr *E);
2201 
2202   /// EmitNullInitialization - Generate code to set a value of the given type to
2203   /// null, If the type contains data member pointers, they will be initialized
2204   /// to -1 in accordance with the Itanium C++ ABI.
2205   void EmitNullInitialization(Address DestPtr, QualType Ty);
2206 
2207   /// Emits a call to an LLVM variable-argument intrinsic, either
2208   /// \c llvm.va_start or \c llvm.va_end.
2209   /// \param ArgValue A reference to the \c va_list as emitted by either
2210   /// \c EmitVAListRef or \c EmitMSVAListRef.
2211   /// \param IsStart If \c true, emits a call to \c llvm.va_start; otherwise,
2212   /// calls \c llvm.va_end.
2213   llvm::Value *EmitVAStartEnd(llvm::Value *ArgValue, bool IsStart);
2214 
2215   /// Generate code to get an argument from the passed in pointer
2216   /// and update it accordingly.
2217   /// \param VE The \c VAArgExpr for which to generate code.
2218   /// \param VAListAddr Receives a reference to the \c va_list as emitted by
2219   /// either \c EmitVAListRef or \c EmitMSVAListRef.
2220   /// \returns A pointer to the argument.
2221   // FIXME: We should be able to get rid of this method and use the va_arg
2222   // instruction in LLVM instead once it works well enough.
2223   Address EmitVAArg(VAArgExpr *VE, Address &VAListAddr);
2224 
2225   /// emitArrayLength - Compute the length of an array, even if it's a
2226   /// VLA, and drill down to the base element type.
2227   llvm::Value *emitArrayLength(const ArrayType *arrayType,
2228                                QualType &baseType,
2229                                Address &addr);
2230 
2231   /// EmitVLASize - Capture all the sizes for the VLA expressions in
2232   /// the given variably-modified type and store them in the VLASizeMap.
2233   ///
2234   /// This function can be called with a null (unreachable) insert point.
2235   void EmitVariablyModifiedType(QualType Ty);
2236 
2237   struct VlaSizePair {
2238     llvm::Value *NumElts;
2239     QualType Type;
2240 
2241     VlaSizePair(llvm::Value *NE, QualType T) : NumElts(NE), Type(T) {}
2242   };
2243 
2244   /// Return the number of elements for a single dimension
2245   /// for the given array type.
2246   VlaSizePair getVLAElements1D(const VariableArrayType *vla);
2247   VlaSizePair getVLAElements1D(QualType vla);
2248 
2249   /// Returns an LLVM value that corresponds to the size,
2250   /// in non-variably-sized elements, of a variable length array type,
2251   /// plus that largest non-variably-sized element type.  Assumes that
2252   /// the type has already been emitted with EmitVariablyModifiedType.
2253   VlaSizePair getVLASize(const VariableArrayType *vla);
2254   VlaSizePair getVLASize(QualType vla);
2255 
2256   /// LoadCXXThis - Load the value of 'this'. This function is only valid while
2257   /// generating code for an C++ member function.
2258   llvm::Value *LoadCXXThis() {
2259     assert(CXXThisValue && "no 'this' value for this function");
2260     return CXXThisValue;
2261   }
2262   Address LoadCXXThisAddress();
2263 
2264   /// LoadCXXVTT - Load the VTT parameter to base constructors/destructors have
2265   /// virtual bases.
2266   // FIXME: Every place that calls LoadCXXVTT is something
2267   // that needs to be abstracted properly.
2268   llvm::Value *LoadCXXVTT() {
2269     assert(CXXStructorImplicitParamValue && "no VTT value for this function");
2270     return CXXStructorImplicitParamValue;
2271   }
2272 
2273   /// GetAddressOfBaseOfCompleteClass - Convert the given pointer to a
2274   /// complete class to the given direct base.
2275   Address
2276   GetAddressOfDirectBaseInCompleteClass(Address Value,
2277                                         const CXXRecordDecl *Derived,
2278                                         const CXXRecordDecl *Base,
2279                                         bool BaseIsVirtual);
2280 
2281   static bool ShouldNullCheckClassCastValue(const CastExpr *Cast);
2282 
2283   /// GetAddressOfBaseClass - This function will add the necessary delta to the
2284   /// load of 'this' and returns address of the base class.
2285   Address GetAddressOfBaseClass(Address Value,
2286                                 const CXXRecordDecl *Derived,
2287                                 CastExpr::path_const_iterator PathBegin,
2288                                 CastExpr::path_const_iterator PathEnd,
2289                                 bool NullCheckValue, SourceLocation Loc);
2290 
2291   Address GetAddressOfDerivedClass(Address Value,
2292                                    const CXXRecordDecl *Derived,
2293                                    CastExpr::path_const_iterator PathBegin,
2294                                    CastExpr::path_const_iterator PathEnd,
2295                                    bool NullCheckValue);
2296 
2297   /// GetVTTParameter - Return the VTT parameter that should be passed to a
2298   /// base constructor/destructor with virtual bases.
2299   /// FIXME: VTTs are Itanium ABI-specific, so the definition should move
2300   /// to ItaniumCXXABI.cpp together with all the references to VTT.
2301   llvm::Value *GetVTTParameter(GlobalDecl GD, bool ForVirtualBase,
2302                                bool Delegating);
2303 
2304   void EmitDelegateCXXConstructorCall(const CXXConstructorDecl *Ctor,
2305                                       CXXCtorType CtorType,
2306                                       const FunctionArgList &Args,
2307                                       SourceLocation Loc);
2308   // It's important not to confuse this and the previous function. Delegating
2309   // constructors are the C++0x feature. The constructor delegate optimization
2310   // is used to reduce duplication in the base and complete consturctors where
2311   // they are substantially the same.
2312   void EmitDelegatingCXXConstructorCall(const CXXConstructorDecl *Ctor,
2313                                         const FunctionArgList &Args);
2314 
2315   /// Emit a call to an inheriting constructor (that is, one that invokes a
2316   /// constructor inherited from a base class) by inlining its definition. This
2317   /// is necessary if the ABI does not support forwarding the arguments to the
2318   /// base class constructor (because they're variadic or similar).
2319   void EmitInlinedInheritingCXXConstructorCall(const CXXConstructorDecl *Ctor,
2320                                                CXXCtorType CtorType,
2321                                                bool ForVirtualBase,
2322                                                bool Delegating,
2323                                                CallArgList &Args);
2324 
2325   /// Emit a call to a constructor inherited from a base class, passing the
2326   /// current constructor's arguments along unmodified (without even making
2327   /// a copy).
2328   void EmitInheritedCXXConstructorCall(const CXXConstructorDecl *D,
2329                                        bool ForVirtualBase, Address This,
2330                                        bool InheritedFromVBase,
2331                                        const CXXInheritedCtorInitExpr *E);
2332 
2333   void EmitCXXConstructorCall(const CXXConstructorDecl *D, CXXCtorType Type,
2334                               bool ForVirtualBase, bool Delegating,
2335                               Address This, const CXXConstructExpr *E,
2336                               AggValueSlot::Overlap_t Overlap);
2337 
2338   void EmitCXXConstructorCall(const CXXConstructorDecl *D, CXXCtorType Type,
2339                               bool ForVirtualBase, bool Delegating,
2340                               Address This, CallArgList &Args,
2341                               AggValueSlot::Overlap_t Overlap);
2342 
2343   /// Emit assumption load for all bases. Requires to be be called only on
2344   /// most-derived class and not under construction of the object.
2345   void EmitVTableAssumptionLoads(const CXXRecordDecl *ClassDecl, Address This);
2346 
2347   /// Emit assumption that vptr load == global vtable.
2348   void EmitVTableAssumptionLoad(const VPtr &vptr, Address This);
2349 
2350   void EmitSynthesizedCXXCopyCtorCall(const CXXConstructorDecl *D,
2351                                       Address This, Address Src,
2352                                       const CXXConstructExpr *E);
2353 
2354   void EmitCXXAggrConstructorCall(const CXXConstructorDecl *D,
2355                                   const ArrayType *ArrayTy,
2356                                   Address ArrayPtr,
2357                                   const CXXConstructExpr *E,
2358                                   bool ZeroInitialization = false);
2359 
2360   void EmitCXXAggrConstructorCall(const CXXConstructorDecl *D,
2361                                   llvm::Value *NumElements,
2362                                   Address ArrayPtr,
2363                                   const CXXConstructExpr *E,
2364                                   bool ZeroInitialization = false);
2365 
2366   static Destroyer destroyCXXObject;
2367 
2368   void EmitCXXDestructorCall(const CXXDestructorDecl *D, CXXDtorType Type,
2369                              bool ForVirtualBase, bool Delegating,
2370                              Address This);
2371 
2372   void EmitNewArrayInitializer(const CXXNewExpr *E, QualType elementType,
2373                                llvm::Type *ElementTy, Address NewPtr,
2374                                llvm::Value *NumElements,
2375                                llvm::Value *AllocSizeWithoutCookie);
2376 
2377   void EmitCXXTemporary(const CXXTemporary *Temporary, QualType TempType,
2378                         Address Ptr);
2379 
2380   llvm::Value *EmitLifetimeStart(uint64_t Size, llvm::Value *Addr);
2381   void EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr);
2382 
2383   llvm::Value *EmitCXXNewExpr(const CXXNewExpr *E);
2384   void EmitCXXDeleteExpr(const CXXDeleteExpr *E);
2385 
2386   void EmitDeleteCall(const FunctionDecl *DeleteFD, llvm::Value *Ptr,
2387                       QualType DeleteTy, llvm::Value *NumElements = nullptr,
2388                       CharUnits CookieSize = CharUnits());
2389 
2390   RValue EmitBuiltinNewDeleteCall(const FunctionProtoType *Type,
2391                                   const CallExpr *TheCallExpr, bool IsDelete);
2392 
2393   llvm::Value *EmitCXXTypeidExpr(const CXXTypeidExpr *E);
2394   llvm::Value *EmitDynamicCast(Address V, const CXXDynamicCastExpr *DCE);
2395   Address EmitCXXUuidofExpr(const CXXUuidofExpr *E);
2396 
2397   /// \brief Situations in which we might emit a check for the suitability of a
2398   ///        pointer or glvalue.
2399   enum TypeCheckKind {
2400     /// Checking the operand of a load. Must be suitably sized and aligned.
2401     TCK_Load,
2402     /// Checking the destination of a store. Must be suitably sized and aligned.
2403     TCK_Store,
2404     /// Checking the bound value in a reference binding. Must be suitably sized
2405     /// and aligned, but is not required to refer to an object (until the
2406     /// reference is used), per core issue 453.
2407     TCK_ReferenceBinding,
2408     /// Checking the object expression in a non-static data member access. Must
2409     /// be an object within its lifetime.
2410     TCK_MemberAccess,
2411     /// Checking the 'this' pointer for a call to a non-static member function.
2412     /// Must be an object within its lifetime.
2413     TCK_MemberCall,
2414     /// Checking the 'this' pointer for a constructor call.
2415     TCK_ConstructorCall,
2416     /// Checking the operand of a static_cast to a derived pointer type. Must be
2417     /// null or an object within its lifetime.
2418     TCK_DowncastPointer,
2419     /// Checking the operand of a static_cast to a derived reference type. Must
2420     /// be an object within its lifetime.
2421     TCK_DowncastReference,
2422     /// Checking the operand of a cast to a base object. Must be suitably sized
2423     /// and aligned.
2424     TCK_Upcast,
2425     /// Checking the operand of a cast to a virtual base object. Must be an
2426     /// object within its lifetime.
2427     TCK_UpcastToVirtualBase,
2428     /// Checking the value assigned to a _Nonnull pointer. Must not be null.
2429     TCK_NonnullAssign,
2430     /// Checking the operand of a dynamic_cast or a typeid expression.  Must be
2431     /// null or an object within its lifetime.
2432     TCK_DynamicOperation
2433   };
2434 
2435   /// Determine whether the pointer type check \p TCK permits null pointers.
2436   static bool isNullPointerAllowed(TypeCheckKind TCK);
2437 
2438   /// Determine whether the pointer type check \p TCK requires a vptr check.
2439   static bool isVptrCheckRequired(TypeCheckKind TCK, QualType Ty);
2440 
2441   /// \brief Whether any type-checking sanitizers are enabled. If \c false,
2442   /// calls to EmitTypeCheck can be skipped.
2443   bool sanitizePerformTypeCheck() const;
2444 
2445   /// \brief Emit a check that \p V is the address of storage of the
2446   /// appropriate size and alignment for an object of type \p Type.
2447   void EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc, llvm::Value *V,
2448                      QualType Type, CharUnits Alignment = CharUnits::Zero(),
2449                      SanitizerSet SkippedChecks = SanitizerSet());
2450 
2451   /// \brief Emit a check that \p Base points into an array object, which
2452   /// we can access at index \p Index. \p Accessed should be \c false if we
2453   /// this expression is used as an lvalue, for instance in "&Arr[Idx]".
2454   void EmitBoundsCheck(const Expr *E, const Expr *Base, llvm::Value *Index,
2455                        QualType IndexType, bool Accessed);
2456 
2457   llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
2458                                        bool isInc, bool isPre);
2459   ComplexPairTy EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
2460                                          bool isInc, bool isPre);
2461 
2462   void EmitAlignmentAssumption(llvm::Value *PtrValue, unsigned Alignment,
2463                                llvm::Value *OffsetValue = nullptr) {
2464     Builder.CreateAlignmentAssumption(CGM.getDataLayout(), PtrValue, Alignment,
2465                                       OffsetValue);
2466   }
2467 
2468   /// Converts Location to a DebugLoc, if debug information is enabled.
2469   llvm::DebugLoc SourceLocToDebugLoc(SourceLocation Location);
2470 
2471 
2472   //===--------------------------------------------------------------------===//
2473   //                            Declaration Emission
2474   //===--------------------------------------------------------------------===//
2475 
2476   /// EmitDecl - Emit a declaration.
2477   ///
2478   /// This function can be called with a null (unreachable) insert point.
2479   void EmitDecl(const Decl &D);
2480 
2481   /// EmitVarDecl - Emit a local variable declaration.
2482   ///
2483   /// This function can be called with a null (unreachable) insert point.
2484   void EmitVarDecl(const VarDecl &D);
2485 
2486   void EmitScalarInit(const Expr *init, const ValueDecl *D, LValue lvalue,
2487                       bool capturedByInit);
2488 
2489   typedef void SpecialInitFn(CodeGenFunction &Init, const VarDecl &D,
2490                              llvm::Value *Address);
2491 
2492   /// \brief Determine whether the given initializer is trivial in the sense
2493   /// that it requires no code to be generated.
2494   bool isTrivialInitializer(const Expr *Init);
2495 
2496   /// EmitAutoVarDecl - Emit an auto variable declaration.
2497   ///
2498   /// This function can be called with a null (unreachable) insert point.
2499   void EmitAutoVarDecl(const VarDecl &D);
2500 
2501   class AutoVarEmission {
2502     friend class CodeGenFunction;
2503 
2504     const VarDecl *Variable;
2505 
2506     /// The address of the alloca.  Invalid if the variable was emitted
2507     /// as a global constant.
2508     Address Addr;
2509 
2510     llvm::Value *NRVOFlag;
2511 
2512     /// True if the variable is a __block variable.
2513     bool IsByRef;
2514 
2515     /// True if the variable is of aggregate type and has a constant
2516     /// initializer.
2517     bool IsConstantAggregate;
2518 
2519     /// Non-null if we should use lifetime annotations.
2520     llvm::Value *SizeForLifetimeMarkers;
2521 
2522     struct Invalid {};
2523     AutoVarEmission(Invalid) : Variable(nullptr), Addr(Address::invalid()) {}
2524 
2525     AutoVarEmission(const VarDecl &variable)
2526       : Variable(&variable), Addr(Address::invalid()), NRVOFlag(nullptr),
2527         IsByRef(false), IsConstantAggregate(false),
2528         SizeForLifetimeMarkers(nullptr) {}
2529 
2530     bool wasEmittedAsGlobal() const { return !Addr.isValid(); }
2531 
2532   public:
2533     static AutoVarEmission invalid() { return AutoVarEmission(Invalid()); }
2534 
2535     bool useLifetimeMarkers() const {
2536       return SizeForLifetimeMarkers != nullptr;
2537     }
2538     llvm::Value *getSizeForLifetimeMarkers() const {
2539       assert(useLifetimeMarkers());
2540       return SizeForLifetimeMarkers;
2541     }
2542 
2543     /// Returns the raw, allocated address, which is not necessarily
2544     /// the address of the object itself.
2545     Address getAllocatedAddress() const {
2546       return Addr;
2547     }
2548 
2549     /// Returns the address of the object within this declaration.
2550     /// Note that this does not chase the forwarding pointer for
2551     /// __block decls.
2552     Address getObjectAddress(CodeGenFunction &CGF) const {
2553       if (!IsByRef) return Addr;
2554 
2555       return CGF.emitBlockByrefAddress(Addr, Variable, /*forward*/ false);
2556     }
2557   };
2558   AutoVarEmission EmitAutoVarAlloca(const VarDecl &var);
2559   void EmitAutoVarInit(const AutoVarEmission &emission);
2560   void EmitAutoVarCleanups(const AutoVarEmission &emission);
2561   void emitAutoVarTypeCleanup(const AutoVarEmission &emission,
2562                               QualType::DestructionKind dtorKind);
2563 
2564   /// Emits the alloca and debug information for the size expressions for each
2565   /// dimension of an array. It registers the association of its (1-dimensional)
2566   /// QualTypes and size expression's debug node, so that CGDebugInfo can
2567   /// reference this node when creating the DISubrange object to describe the
2568   /// array types.
2569   void EmitAndRegisterVariableArrayDimensions(CGDebugInfo *DI,
2570                                               const VarDecl &D,
2571                                               bool EmitDebugInfo);
2572 
2573   void EmitStaticVarDecl(const VarDecl &D,
2574                          llvm::GlobalValue::LinkageTypes Linkage);
2575 
2576   class ParamValue {
2577     llvm::Value *Value;
2578     unsigned Alignment;
2579     ParamValue(llvm::Value *V, unsigned A) : Value(V), Alignment(A) {}
2580   public:
2581     static ParamValue forDirect(llvm::Value *value) {
2582       return ParamValue(value, 0);
2583     }
2584     static ParamValue forIndirect(Address addr) {
2585       assert(!addr.getAlignment().isZero());
2586       return ParamValue(addr.getPointer(), addr.getAlignment().getQuantity());
2587     }
2588 
2589     bool isIndirect() const { return Alignment != 0; }
2590     llvm::Value *getAnyValue() const { return Value; }
2591 
2592     llvm::Value *getDirectValue() const {
2593       assert(!isIndirect());
2594       return Value;
2595     }
2596 
2597     Address getIndirectAddress() const {
2598       assert(isIndirect());
2599       return Address(Value, CharUnits::fromQuantity(Alignment));
2600     }
2601   };
2602 
2603   /// EmitParmDecl - Emit a ParmVarDecl or an ImplicitParamDecl.
2604   void EmitParmDecl(const VarDecl &D, ParamValue Arg, unsigned ArgNo);
2605 
2606   /// protectFromPeepholes - Protect a value that we're intending to
2607   /// store to the side, but which will probably be used later, from
2608   /// aggressive peepholing optimizations that might delete it.
2609   ///
2610   /// Pass the result to unprotectFromPeepholes to declare that
2611   /// protection is no longer required.
2612   ///
2613   /// There's no particular reason why this shouldn't apply to
2614   /// l-values, it's just that no existing peepholes work on pointers.
2615   PeepholeProtection protectFromPeepholes(RValue rvalue);
2616   void unprotectFromPeepholes(PeepholeProtection protection);
2617 
2618   void EmitAlignmentAssumption(llvm::Value *PtrValue, llvm::Value *Alignment,
2619                                llvm::Value *OffsetValue = nullptr) {
2620     Builder.CreateAlignmentAssumption(CGM.getDataLayout(), PtrValue, Alignment,
2621                                       OffsetValue);
2622   }
2623 
2624   //===--------------------------------------------------------------------===//
2625   //                             Statement Emission
2626   //===--------------------------------------------------------------------===//
2627 
2628   /// EmitStopPoint - Emit a debug stoppoint if we are emitting debug info.
2629   void EmitStopPoint(const Stmt *S);
2630 
2631   /// EmitStmt - Emit the code for the statement \arg S. It is legal to call
2632   /// this function even if there is no current insertion point.
2633   ///
2634   /// This function may clear the current insertion point; callers should use
2635   /// EnsureInsertPoint if they wish to subsequently generate code without first
2636   /// calling EmitBlock, EmitBranch, or EmitStmt.
2637   void EmitStmt(const Stmt *S, ArrayRef<const Attr *> Attrs = None);
2638 
2639   /// EmitSimpleStmt - Try to emit a "simple" statement which does not
2640   /// necessarily require an insertion point or debug information; typically
2641   /// because the statement amounts to a jump or a container of other
2642   /// statements.
2643   ///
2644   /// \return True if the statement was handled.
2645   bool EmitSimpleStmt(const Stmt *S);
2646 
2647   Address EmitCompoundStmt(const CompoundStmt &S, bool GetLast = false,
2648                            AggValueSlot AVS = AggValueSlot::ignored());
2649   Address EmitCompoundStmtWithoutScope(const CompoundStmt &S,
2650                                        bool GetLast = false,
2651                                        AggValueSlot AVS =
2652                                                 AggValueSlot::ignored());
2653 
2654   /// EmitLabel - Emit the block for the given label. It is legal to call this
2655   /// function even if there is no current insertion point.
2656   void EmitLabel(const LabelDecl *D); // helper for EmitLabelStmt.
2657 
2658   void EmitLabelStmt(const LabelStmt &S);
2659   void EmitAttributedStmt(const AttributedStmt &S);
2660   void EmitGotoStmt(const GotoStmt &S);
2661   void EmitIndirectGotoStmt(const IndirectGotoStmt &S);
2662   void EmitIfStmt(const IfStmt &S);
2663 
2664   void EmitWhileStmt(const WhileStmt &S,
2665                      ArrayRef<const Attr *> Attrs = None);
2666   void EmitDoStmt(const DoStmt &S, ArrayRef<const Attr *> Attrs = None);
2667   void EmitForStmt(const ForStmt &S,
2668                    ArrayRef<const Attr *> Attrs = None);
2669   void EmitReturnStmt(const ReturnStmt &S);
2670   void EmitDeclStmt(const DeclStmt &S);
2671   void EmitBreakStmt(const BreakStmt &S);
2672   void EmitContinueStmt(const ContinueStmt &S);
2673   void EmitSwitchStmt(const SwitchStmt &S);
2674   void EmitDefaultStmt(const DefaultStmt &S);
2675   void EmitCaseStmt(const CaseStmt &S);
2676   void EmitCaseStmtRange(const CaseStmt &S);
2677   void EmitAsmStmt(const AsmStmt &S);
2678 
2679   void EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S);
2680   void EmitObjCAtTryStmt(const ObjCAtTryStmt &S);
2681   void EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S);
2682   void EmitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt &S);
2683   void EmitObjCAutoreleasePoolStmt(const ObjCAutoreleasePoolStmt &S);
2684 
2685   void EmitCoroutineBody(const CoroutineBodyStmt &S);
2686   void EmitCoreturnStmt(const CoreturnStmt &S);
2687   RValue EmitCoawaitExpr(const CoawaitExpr &E,
2688                          AggValueSlot aggSlot = AggValueSlot::ignored(),
2689                          bool ignoreResult = false);
2690   LValue EmitCoawaitLValue(const CoawaitExpr *E);
2691   RValue EmitCoyieldExpr(const CoyieldExpr &E,
2692                          AggValueSlot aggSlot = AggValueSlot::ignored(),
2693                          bool ignoreResult = false);
2694   LValue EmitCoyieldLValue(const CoyieldExpr *E);
2695   RValue EmitCoroutineIntrinsic(const CallExpr *E, unsigned int IID);
2696 
2697   void EnterCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
2698   void ExitCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
2699 
2700   void EmitCXXTryStmt(const CXXTryStmt &S);
2701   void EmitSEHTryStmt(const SEHTryStmt &S);
2702   void EmitSEHLeaveStmt(const SEHLeaveStmt &S);
2703   void EnterSEHTryStmt(const SEHTryStmt &S);
2704   void ExitSEHTryStmt(const SEHTryStmt &S);
2705 
2706   void startOutlinedSEHHelper(CodeGenFunction &ParentCGF, bool IsFilter,
2707                               const Stmt *OutlinedStmt);
2708 
2709   llvm::Function *GenerateSEHFilterFunction(CodeGenFunction &ParentCGF,
2710                                             const SEHExceptStmt &Except);
2711 
2712   llvm::Function *GenerateSEHFinallyFunction(CodeGenFunction &ParentCGF,
2713                                              const SEHFinallyStmt &Finally);
2714 
2715   void EmitSEHExceptionCodeSave(CodeGenFunction &ParentCGF,
2716                                 llvm::Value *ParentFP,
2717                                 llvm::Value *EntryEBP);
2718   llvm::Value *EmitSEHExceptionCode();
2719   llvm::Value *EmitSEHExceptionInfo();
2720   llvm::Value *EmitSEHAbnormalTermination();
2721 
2722   /// Emit simple code for OpenMP directives in Simd-only mode.
2723   void EmitSimpleOMPExecutableDirective(const OMPExecutableDirective &D);
2724 
2725   /// Scan the outlined statement for captures from the parent function. For
2726   /// each capture, mark the capture as escaped and emit a call to
2727   /// llvm.localrecover. Insert the localrecover result into the LocalDeclMap.
2728   void EmitCapturedLocals(CodeGenFunction &ParentCGF, const Stmt *OutlinedStmt,
2729                           bool IsFilter);
2730 
2731   /// Recovers the address of a local in a parent function. ParentVar is the
2732   /// address of the variable used in the immediate parent function. It can
2733   /// either be an alloca or a call to llvm.localrecover if there are nested
2734   /// outlined functions. ParentFP is the frame pointer of the outermost parent
2735   /// frame.
2736   Address recoverAddrOfEscapedLocal(CodeGenFunction &ParentCGF,
2737                                     Address ParentVar,
2738                                     llvm::Value *ParentFP);
2739 
2740   void EmitCXXForRangeStmt(const CXXForRangeStmt &S,
2741                            ArrayRef<const Attr *> Attrs = None);
2742 
2743   /// Controls insertion of cancellation exit blocks in worksharing constructs.
2744   class OMPCancelStackRAII {
2745     CodeGenFunction &CGF;
2746 
2747   public:
2748     OMPCancelStackRAII(CodeGenFunction &CGF, OpenMPDirectiveKind Kind,
2749                        bool HasCancel)
2750         : CGF(CGF) {
2751       CGF.OMPCancelStack.enter(CGF, Kind, HasCancel);
2752     }
2753     ~OMPCancelStackRAII() { CGF.OMPCancelStack.exit(CGF); }
2754   };
2755 
2756   /// Returns calculated size of the specified type.
2757   llvm::Value *getTypeSize(QualType Ty);
2758   LValue InitCapturedStruct(const CapturedStmt &S);
2759   llvm::Function *EmitCapturedStmt(const CapturedStmt &S, CapturedRegionKind K);
2760   llvm::Function *GenerateCapturedStmtFunction(const CapturedStmt &S);
2761   Address GenerateCapturedStmtArgument(const CapturedStmt &S);
2762   llvm::Function *GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S);
2763   void GenerateOpenMPCapturedVars(const CapturedStmt &S,
2764                                   SmallVectorImpl<llvm::Value *> &CapturedVars);
2765   void emitOMPSimpleStore(LValue LVal, RValue RVal, QualType RValTy,
2766                           SourceLocation Loc);
2767   /// \brief Perform element by element copying of arrays with type \a
2768   /// OriginalType from \a SrcAddr to \a DestAddr using copying procedure
2769   /// generated by \a CopyGen.
2770   ///
2771   /// \param DestAddr Address of the destination array.
2772   /// \param SrcAddr Address of the source array.
2773   /// \param OriginalType Type of destination and source arrays.
2774   /// \param CopyGen Copying procedure that copies value of single array element
2775   /// to another single array element.
2776   void EmitOMPAggregateAssign(
2777       Address DestAddr, Address SrcAddr, QualType OriginalType,
2778       const llvm::function_ref<void(Address, Address)> CopyGen);
2779   /// \brief Emit proper copying of data from one variable to another.
2780   ///
2781   /// \param OriginalType Original type of the copied variables.
2782   /// \param DestAddr Destination address.
2783   /// \param SrcAddr Source address.
2784   /// \param DestVD Destination variable used in \a CopyExpr (for arrays, has
2785   /// type of the base array element).
2786   /// \param SrcVD Source variable used in \a CopyExpr (for arrays, has type of
2787   /// the base array element).
2788   /// \param Copy Actual copygin expression for copying data from \a SrcVD to \a
2789   /// DestVD.
2790   void EmitOMPCopy(QualType OriginalType,
2791                    Address DestAddr, Address SrcAddr,
2792                    const VarDecl *DestVD, const VarDecl *SrcVD,
2793                    const Expr *Copy);
2794   /// \brief Emit atomic update code for constructs: \a X = \a X \a BO \a E or
2795   /// \a X = \a E \a BO \a E.
2796   ///
2797   /// \param X Value to be updated.
2798   /// \param E Update value.
2799   /// \param BO Binary operation for update operation.
2800   /// \param IsXLHSInRHSPart true if \a X is LHS in RHS part of the update
2801   /// expression, false otherwise.
2802   /// \param AO Atomic ordering of the generated atomic instructions.
2803   /// \param CommonGen Code generator for complex expressions that cannot be
2804   /// expressed through atomicrmw instruction.
2805   /// \returns <true, OldAtomicValue> if simple 'atomicrmw' instruction was
2806   /// generated, <false, RValue::get(nullptr)> otherwise.
2807   std::pair<bool, RValue> EmitOMPAtomicSimpleUpdateExpr(
2808       LValue X, RValue E, BinaryOperatorKind BO, bool IsXLHSInRHSPart,
2809       llvm::AtomicOrdering AO, SourceLocation Loc,
2810       const llvm::function_ref<RValue(RValue)> CommonGen);
2811   bool EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
2812                                  OMPPrivateScope &PrivateScope);
2813   void EmitOMPPrivateClause(const OMPExecutableDirective &D,
2814                             OMPPrivateScope &PrivateScope);
2815   void EmitOMPUseDevicePtrClause(
2816       const OMPClause &C, OMPPrivateScope &PrivateScope,
2817       const llvm::DenseMap<const ValueDecl *, Address> &CaptureDeviceAddrMap);
2818   /// \brief Emit code for copyin clause in \a D directive. The next code is
2819   /// generated at the start of outlined functions for directives:
2820   /// \code
2821   /// threadprivate_var1 = master_threadprivate_var1;
2822   /// operator=(threadprivate_var2, master_threadprivate_var2);
2823   /// ...
2824   /// __kmpc_barrier(&loc, global_tid);
2825   /// \endcode
2826   ///
2827   /// \param D OpenMP directive possibly with 'copyin' clause(s).
2828   /// \returns true if at least one copyin variable is found, false otherwise.
2829   bool EmitOMPCopyinClause(const OMPExecutableDirective &D);
2830   /// \brief Emit initial code for lastprivate variables. If some variable is
2831   /// not also firstprivate, then the default initialization is used. Otherwise
2832   /// initialization of this variable is performed by EmitOMPFirstprivateClause
2833   /// method.
2834   ///
2835   /// \param D Directive that may have 'lastprivate' directives.
2836   /// \param PrivateScope Private scope for capturing lastprivate variables for
2837   /// proper codegen in internal captured statement.
2838   ///
2839   /// \returns true if there is at least one lastprivate variable, false
2840   /// otherwise.
2841   bool EmitOMPLastprivateClauseInit(const OMPExecutableDirective &D,
2842                                     OMPPrivateScope &PrivateScope);
2843   /// \brief Emit final copying of lastprivate values to original variables at
2844   /// the end of the worksharing or simd directive.
2845   ///
2846   /// \param D Directive that has at least one 'lastprivate' directives.
2847   /// \param IsLastIterCond Boolean condition that must be set to 'i1 true' if
2848   /// it is the last iteration of the loop code in associated directive, or to
2849   /// 'i1 false' otherwise. If this item is nullptr, no final check is required.
2850   void EmitOMPLastprivateClauseFinal(const OMPExecutableDirective &D,
2851                                      bool NoFinals,
2852                                      llvm::Value *IsLastIterCond = nullptr);
2853   /// Emit initial code for linear clauses.
2854   void EmitOMPLinearClause(const OMPLoopDirective &D,
2855                            CodeGenFunction::OMPPrivateScope &PrivateScope);
2856   /// Emit final code for linear clauses.
2857   /// \param CondGen Optional conditional code for final part of codegen for
2858   /// linear clause.
2859   void EmitOMPLinearClauseFinal(
2860       const OMPLoopDirective &D,
2861       const llvm::function_ref<llvm::Value *(CodeGenFunction &)> CondGen);
2862   /// \brief Emit initial code for reduction variables. Creates reduction copies
2863   /// and initializes them with the values according to OpenMP standard.
2864   ///
2865   /// \param D Directive (possibly) with the 'reduction' clause.
2866   /// \param PrivateScope Private scope for capturing reduction variables for
2867   /// proper codegen in internal captured statement.
2868   ///
2869   void EmitOMPReductionClauseInit(const OMPExecutableDirective &D,
2870                                   OMPPrivateScope &PrivateScope);
2871   /// \brief Emit final update of reduction values to original variables at
2872   /// the end of the directive.
2873   ///
2874   /// \param D Directive that has at least one 'reduction' directives.
2875   /// \param ReductionKind The kind of reduction to perform.
2876   void EmitOMPReductionClauseFinal(const OMPExecutableDirective &D,
2877                                    const OpenMPDirectiveKind ReductionKind);
2878   /// \brief Emit initial code for linear variables. Creates private copies
2879   /// and initializes them with the values according to OpenMP standard.
2880   ///
2881   /// \param D Directive (possibly) with the 'linear' clause.
2882   /// \return true if at least one linear variable is found that should be
2883   /// initialized with the value of the original variable, false otherwise.
2884   bool EmitOMPLinearClauseInit(const OMPLoopDirective &D);
2885 
2886   typedef const llvm::function_ref<void(CodeGenFunction & /*CGF*/,
2887                                         llvm::Value * /*OutlinedFn*/,
2888                                         const OMPTaskDataTy & /*Data*/)>
2889       TaskGenTy;
2890   void EmitOMPTaskBasedDirective(const OMPExecutableDirective &S,
2891                                  const OpenMPDirectiveKind CapturedRegion,
2892                                  const RegionCodeGenTy &BodyGen,
2893                                  const TaskGenTy &TaskGen, OMPTaskDataTy &Data);
2894   struct OMPTargetDataInfo {
2895     Address BasePointersArray = Address::invalid();
2896     Address PointersArray = Address::invalid();
2897     Address SizesArray = Address::invalid();
2898     unsigned NumberOfTargetItems = 0;
2899     explicit OMPTargetDataInfo() = default;
2900     OMPTargetDataInfo(Address BasePointersArray, Address PointersArray,
2901                       Address SizesArray, unsigned NumberOfTargetItems)
2902         : BasePointersArray(BasePointersArray), PointersArray(PointersArray),
2903           SizesArray(SizesArray), NumberOfTargetItems(NumberOfTargetItems) {}
2904   };
2905   void EmitOMPTargetTaskBasedDirective(const OMPExecutableDirective &S,
2906                                        const RegionCodeGenTy &BodyGen,
2907                                        OMPTargetDataInfo &InputInfo);
2908 
2909   void EmitOMPParallelDirective(const OMPParallelDirective &S);
2910   void EmitOMPSimdDirective(const OMPSimdDirective &S);
2911   void EmitOMPForDirective(const OMPForDirective &S);
2912   void EmitOMPForSimdDirective(const OMPForSimdDirective &S);
2913   void EmitOMPSectionsDirective(const OMPSectionsDirective &S);
2914   void EmitOMPSectionDirective(const OMPSectionDirective &S);
2915   void EmitOMPSingleDirective(const OMPSingleDirective &S);
2916   void EmitOMPMasterDirective(const OMPMasterDirective &S);
2917   void EmitOMPCriticalDirective(const OMPCriticalDirective &S);
2918   void EmitOMPParallelForDirective(const OMPParallelForDirective &S);
2919   void EmitOMPParallelForSimdDirective(const OMPParallelForSimdDirective &S);
2920   void EmitOMPParallelSectionsDirective(const OMPParallelSectionsDirective &S);
2921   void EmitOMPTaskDirective(const OMPTaskDirective &S);
2922   void EmitOMPTaskyieldDirective(const OMPTaskyieldDirective &S);
2923   void EmitOMPBarrierDirective(const OMPBarrierDirective &S);
2924   void EmitOMPTaskwaitDirective(const OMPTaskwaitDirective &S);
2925   void EmitOMPTaskgroupDirective(const OMPTaskgroupDirective &S);
2926   void EmitOMPFlushDirective(const OMPFlushDirective &S);
2927   void EmitOMPOrderedDirective(const OMPOrderedDirective &S);
2928   void EmitOMPAtomicDirective(const OMPAtomicDirective &S);
2929   void EmitOMPTargetDirective(const OMPTargetDirective &S);
2930   void EmitOMPTargetDataDirective(const OMPTargetDataDirective &S);
2931   void EmitOMPTargetEnterDataDirective(const OMPTargetEnterDataDirective &S);
2932   void EmitOMPTargetExitDataDirective(const OMPTargetExitDataDirective &S);
2933   void EmitOMPTargetUpdateDirective(const OMPTargetUpdateDirective &S);
2934   void EmitOMPTargetParallelDirective(const OMPTargetParallelDirective &S);
2935   void
2936   EmitOMPTargetParallelForDirective(const OMPTargetParallelForDirective &S);
2937   void EmitOMPTeamsDirective(const OMPTeamsDirective &S);
2938   void
2939   EmitOMPCancellationPointDirective(const OMPCancellationPointDirective &S);
2940   void EmitOMPCancelDirective(const OMPCancelDirective &S);
2941   void EmitOMPTaskLoopBasedDirective(const OMPLoopDirective &S);
2942   void EmitOMPTaskLoopDirective(const OMPTaskLoopDirective &S);
2943   void EmitOMPTaskLoopSimdDirective(const OMPTaskLoopSimdDirective &S);
2944   void EmitOMPDistributeDirective(const OMPDistributeDirective &S);
2945   void EmitOMPDistributeParallelForDirective(
2946       const OMPDistributeParallelForDirective &S);
2947   void EmitOMPDistributeParallelForSimdDirective(
2948       const OMPDistributeParallelForSimdDirective &S);
2949   void EmitOMPDistributeSimdDirective(const OMPDistributeSimdDirective &S);
2950   void EmitOMPTargetParallelForSimdDirective(
2951       const OMPTargetParallelForSimdDirective &S);
2952   void EmitOMPTargetSimdDirective(const OMPTargetSimdDirective &S);
2953   void EmitOMPTeamsDistributeDirective(const OMPTeamsDistributeDirective &S);
2954   void
2955   EmitOMPTeamsDistributeSimdDirective(const OMPTeamsDistributeSimdDirective &S);
2956   void EmitOMPTeamsDistributeParallelForSimdDirective(
2957       const OMPTeamsDistributeParallelForSimdDirective &S);
2958   void EmitOMPTeamsDistributeParallelForDirective(
2959       const OMPTeamsDistributeParallelForDirective &S);
2960   void EmitOMPTargetTeamsDirective(const OMPTargetTeamsDirective &S);
2961   void EmitOMPTargetTeamsDistributeDirective(
2962       const OMPTargetTeamsDistributeDirective &S);
2963   void EmitOMPTargetTeamsDistributeParallelForDirective(
2964       const OMPTargetTeamsDistributeParallelForDirective &S);
2965   void EmitOMPTargetTeamsDistributeParallelForSimdDirective(
2966       const OMPTargetTeamsDistributeParallelForSimdDirective &S);
2967   void EmitOMPTargetTeamsDistributeSimdDirective(
2968       const OMPTargetTeamsDistributeSimdDirective &S);
2969 
2970   /// Emit device code for the target directive.
2971   static void EmitOMPTargetDeviceFunction(CodeGenModule &CGM,
2972                                           StringRef ParentName,
2973                                           const OMPTargetDirective &S);
2974   static void
2975   EmitOMPTargetParallelDeviceFunction(CodeGenModule &CGM, StringRef ParentName,
2976                                       const OMPTargetParallelDirective &S);
2977   /// Emit device code for the target parallel for directive.
2978   static void EmitOMPTargetParallelForDeviceFunction(
2979       CodeGenModule &CGM, StringRef ParentName,
2980       const OMPTargetParallelForDirective &S);
2981   /// Emit device code for the target parallel for simd directive.
2982   static void EmitOMPTargetParallelForSimdDeviceFunction(
2983       CodeGenModule &CGM, StringRef ParentName,
2984       const OMPTargetParallelForSimdDirective &S);
2985   /// Emit device code for the target teams directive.
2986   static void
2987   EmitOMPTargetTeamsDeviceFunction(CodeGenModule &CGM, StringRef ParentName,
2988                                    const OMPTargetTeamsDirective &S);
2989   /// Emit device code for the target teams distribute directive.
2990   static void EmitOMPTargetTeamsDistributeDeviceFunction(
2991       CodeGenModule &CGM, StringRef ParentName,
2992       const OMPTargetTeamsDistributeDirective &S);
2993   /// Emit device code for the target teams distribute simd directive.
2994   static void EmitOMPTargetTeamsDistributeSimdDeviceFunction(
2995       CodeGenModule &CGM, StringRef ParentName,
2996       const OMPTargetTeamsDistributeSimdDirective &S);
2997   /// Emit device code for the target simd directive.
2998   static void EmitOMPTargetSimdDeviceFunction(CodeGenModule &CGM,
2999                                               StringRef ParentName,
3000                                               const OMPTargetSimdDirective &S);
3001   /// Emit device code for the target teams distribute parallel for simd
3002   /// directive.
3003   static void EmitOMPTargetTeamsDistributeParallelForSimdDeviceFunction(
3004       CodeGenModule &CGM, StringRef ParentName,
3005       const OMPTargetTeamsDistributeParallelForSimdDirective &S);
3006 
3007   static void EmitOMPTargetTeamsDistributeParallelForDeviceFunction(
3008       CodeGenModule &CGM, StringRef ParentName,
3009       const OMPTargetTeamsDistributeParallelForDirective &S);
3010   /// \brief Emit inner loop of the worksharing/simd construct.
3011   ///
3012   /// \param S Directive, for which the inner loop must be emitted.
3013   /// \param RequiresCleanup true, if directive has some associated private
3014   /// variables.
3015   /// \param LoopCond Bollean condition for loop continuation.
3016   /// \param IncExpr Increment expression for loop control variable.
3017   /// \param BodyGen Generator for the inner body of the inner loop.
3018   /// \param PostIncGen Genrator for post-increment code (required for ordered
3019   /// loop directvies).
3020   void EmitOMPInnerLoop(
3021       const Stmt &S, bool RequiresCleanup, const Expr *LoopCond,
3022       const Expr *IncExpr,
3023       const llvm::function_ref<void(CodeGenFunction &)> BodyGen,
3024       const llvm::function_ref<void(CodeGenFunction &)> PostIncGen);
3025 
3026   JumpDest getOMPCancelDestination(OpenMPDirectiveKind Kind);
3027   /// Emit initial code for loop counters of loop-based directives.
3028   void EmitOMPPrivateLoopCounters(const OMPLoopDirective &S,
3029                                   OMPPrivateScope &LoopScope);
3030 
3031   /// Helper for the OpenMP loop directives.
3032   void EmitOMPLoopBody(const OMPLoopDirective &D, JumpDest LoopExit);
3033 
3034   /// \brief Emit code for the worksharing loop-based directive.
3035   /// \return true, if this construct has any lastprivate clause, false -
3036   /// otherwise.
3037   bool EmitOMPWorksharingLoop(const OMPLoopDirective &S, Expr *EUB,
3038                               const CodeGenLoopBoundsTy &CodeGenLoopBounds,
3039                               const CodeGenDispatchBoundsTy &CGDispatchBounds);
3040 
3041   /// Emit code for the distribute loop-based directive.
3042   void EmitOMPDistributeLoop(const OMPLoopDirective &S,
3043                              const CodeGenLoopTy &CodeGenLoop, Expr *IncExpr);
3044 
3045   /// Helpers for the OpenMP loop directives.
3046   void EmitOMPSimdInit(const OMPLoopDirective &D, bool IsMonotonic = false);
3047   void EmitOMPSimdFinal(
3048       const OMPLoopDirective &D,
3049       const llvm::function_ref<llvm::Value *(CodeGenFunction &)> CondGen);
3050 
3051   /// Emits the lvalue for the expression with possibly captured variable.
3052   LValue EmitOMPSharedLValue(const Expr *E);
3053 
3054 private:
3055   /// Helpers for blocks.
3056   llvm::Value *EmitBlockLiteral(const CGBlockInfo &Info);
3057 
3058   /// struct with the values to be passed to the OpenMP loop-related functions
3059   struct OMPLoopArguments {
3060     /// loop lower bound
3061     Address LB = Address::invalid();
3062     /// loop upper bound
3063     Address UB = Address::invalid();
3064     /// loop stride
3065     Address ST = Address::invalid();
3066     /// isLastIteration argument for runtime functions
3067     Address IL = Address::invalid();
3068     /// Chunk value generated by sema
3069     llvm::Value *Chunk = nullptr;
3070     /// EnsureUpperBound
3071     Expr *EUB = nullptr;
3072     /// IncrementExpression
3073     Expr *IncExpr = nullptr;
3074     /// Loop initialization
3075     Expr *Init = nullptr;
3076     /// Loop exit condition
3077     Expr *Cond = nullptr;
3078     /// Update of LB after a whole chunk has been executed
3079     Expr *NextLB = nullptr;
3080     /// Update of UB after a whole chunk has been executed
3081     Expr *NextUB = nullptr;
3082     OMPLoopArguments() = default;
3083     OMPLoopArguments(Address LB, Address UB, Address ST, Address IL,
3084                      llvm::Value *Chunk = nullptr, Expr *EUB = nullptr,
3085                      Expr *IncExpr = nullptr, Expr *Init = nullptr,
3086                      Expr *Cond = nullptr, Expr *NextLB = nullptr,
3087                      Expr *NextUB = nullptr)
3088         : LB(LB), UB(UB), ST(ST), IL(IL), Chunk(Chunk), EUB(EUB),
3089           IncExpr(IncExpr), Init(Init), Cond(Cond), NextLB(NextLB),
3090           NextUB(NextUB) {}
3091   };
3092   void EmitOMPOuterLoop(bool DynamicOrOrdered, bool IsMonotonic,
3093                         const OMPLoopDirective &S, OMPPrivateScope &LoopScope,
3094                         const OMPLoopArguments &LoopArgs,
3095                         const CodeGenLoopTy &CodeGenLoop,
3096                         const CodeGenOrderedTy &CodeGenOrdered);
3097   void EmitOMPForOuterLoop(const OpenMPScheduleTy &ScheduleKind,
3098                            bool IsMonotonic, const OMPLoopDirective &S,
3099                            OMPPrivateScope &LoopScope, bool Ordered,
3100                            const OMPLoopArguments &LoopArgs,
3101                            const CodeGenDispatchBoundsTy &CGDispatchBounds);
3102   void EmitOMPDistributeOuterLoop(OpenMPDistScheduleClauseKind ScheduleKind,
3103                                   const OMPLoopDirective &S,
3104                                   OMPPrivateScope &LoopScope,
3105                                   const OMPLoopArguments &LoopArgs,
3106                                   const CodeGenLoopTy &CodeGenLoopContent);
3107   /// \brief Emit code for sections directive.
3108   void EmitSections(const OMPExecutableDirective &S);
3109 
3110 public:
3111 
3112   //===--------------------------------------------------------------------===//
3113   //                         LValue Expression Emission
3114   //===--------------------------------------------------------------------===//
3115 
3116   /// GetUndefRValue - Get an appropriate 'undef' rvalue for the given type.
3117   RValue GetUndefRValue(QualType Ty);
3118 
3119   /// EmitUnsupportedRValue - Emit a dummy r-value using the type of E
3120   /// and issue an ErrorUnsupported style diagnostic (using the
3121   /// provided Name).
3122   RValue EmitUnsupportedRValue(const Expr *E,
3123                                const char *Name);
3124 
3125   /// EmitUnsupportedLValue - Emit a dummy l-value using the type of E and issue
3126   /// an ErrorUnsupported style diagnostic (using the provided Name).
3127   LValue EmitUnsupportedLValue(const Expr *E,
3128                                const char *Name);
3129 
3130   /// EmitLValue - Emit code to compute a designator that specifies the location
3131   /// of the expression.
3132   ///
3133   /// This can return one of two things: a simple address or a bitfield
3134   /// reference.  In either case, the LLVM Value* in the LValue structure is
3135   /// guaranteed to be an LLVM pointer type.
3136   ///
3137   /// If this returns a bitfield reference, nothing about the pointee type of
3138   /// the LLVM value is known: For example, it may not be a pointer to an
3139   /// integer.
3140   ///
3141   /// If this returns a normal address, and if the lvalue's C type is fixed
3142   /// size, this method guarantees that the returned pointer type will point to
3143   /// an LLVM type of the same size of the lvalue's type.  If the lvalue has a
3144   /// variable length type, this is not possible.
3145   ///
3146   LValue EmitLValue(const Expr *E);
3147 
3148   /// \brief Same as EmitLValue but additionally we generate checking code to
3149   /// guard against undefined behavior.  This is only suitable when we know
3150   /// that the address will be used to access the object.
3151   LValue EmitCheckedLValue(const Expr *E, TypeCheckKind TCK);
3152 
3153   RValue convertTempToRValue(Address addr, QualType type,
3154                              SourceLocation Loc);
3155 
3156   void EmitAtomicInit(Expr *E, LValue lvalue);
3157 
3158   bool LValueIsSuitableForInlineAtomic(LValue Src);
3159 
3160   RValue EmitAtomicLoad(LValue LV, SourceLocation SL,
3161                         AggValueSlot Slot = AggValueSlot::ignored());
3162 
3163   RValue EmitAtomicLoad(LValue lvalue, SourceLocation loc,
3164                         llvm::AtomicOrdering AO, bool IsVolatile = false,
3165                         AggValueSlot slot = AggValueSlot::ignored());
3166 
3167   void EmitAtomicStore(RValue rvalue, LValue lvalue, bool isInit);
3168 
3169   void EmitAtomicStore(RValue rvalue, LValue lvalue, llvm::AtomicOrdering AO,
3170                        bool IsVolatile, bool isInit);
3171 
3172   std::pair<RValue, llvm::Value *> EmitAtomicCompareExchange(
3173       LValue Obj, RValue Expected, RValue Desired, SourceLocation Loc,
3174       llvm::AtomicOrdering Success =
3175           llvm::AtomicOrdering::SequentiallyConsistent,
3176       llvm::AtomicOrdering Failure =
3177           llvm::AtomicOrdering::SequentiallyConsistent,
3178       bool IsWeak = false, AggValueSlot Slot = AggValueSlot::ignored());
3179 
3180   void EmitAtomicUpdate(LValue LVal, llvm::AtomicOrdering AO,
3181                         const llvm::function_ref<RValue(RValue)> &UpdateOp,
3182                         bool IsVolatile);
3183 
3184   /// EmitToMemory - Change a scalar value from its value
3185   /// representation to its in-memory representation.
3186   llvm::Value *EmitToMemory(llvm::Value *Value, QualType Ty);
3187 
3188   /// EmitFromMemory - Change a scalar value from its memory
3189   /// representation to its value representation.
3190   llvm::Value *EmitFromMemory(llvm::Value *Value, QualType Ty);
3191 
3192   /// Check if the scalar \p Value is within the valid range for the given
3193   /// type \p Ty.
3194   ///
3195   /// Returns true if a check is needed (even if the range is unknown).
3196   bool EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
3197                             SourceLocation Loc);
3198 
3199   /// EmitLoadOfScalar - Load a scalar value from an address, taking
3200   /// care to appropriately convert from the memory representation to
3201   /// the LLVM value representation.
3202   llvm::Value *EmitLoadOfScalar(Address Addr, bool Volatile, QualType Ty,
3203                                 SourceLocation Loc,
3204                                 AlignmentSource Source = AlignmentSource::Type,
3205                                 bool isNontemporal = false) {
3206     return EmitLoadOfScalar(Addr, Volatile, Ty, Loc, LValueBaseInfo(Source),
3207                             CGM.getTBAAAccessInfo(Ty), isNontemporal);
3208   }
3209 
3210   llvm::Value *EmitLoadOfScalar(Address Addr, bool Volatile, QualType Ty,
3211                                 SourceLocation Loc, LValueBaseInfo BaseInfo,
3212                                 TBAAAccessInfo TBAAInfo,
3213                                 bool isNontemporal = false);
3214 
3215   /// EmitLoadOfScalar - Load a scalar value from an address, taking
3216   /// care to appropriately convert from the memory representation to
3217   /// the LLVM value representation.  The l-value must be a simple
3218   /// l-value.
3219   llvm::Value *EmitLoadOfScalar(LValue lvalue, SourceLocation Loc);
3220 
3221   /// EmitStoreOfScalar - Store a scalar value to an address, taking
3222   /// care to appropriately convert from the memory representation to
3223   /// the LLVM value representation.
3224   void EmitStoreOfScalar(llvm::Value *Value, Address Addr,
3225                          bool Volatile, QualType Ty,
3226                          AlignmentSource Source = AlignmentSource::Type,
3227                          bool isInit = false, bool isNontemporal = false) {
3228     EmitStoreOfScalar(Value, Addr, Volatile, Ty, LValueBaseInfo(Source),
3229                       CGM.getTBAAAccessInfo(Ty), isInit, isNontemporal);
3230   }
3231 
3232   void EmitStoreOfScalar(llvm::Value *Value, Address Addr,
3233                          bool Volatile, QualType Ty,
3234                          LValueBaseInfo BaseInfo, TBAAAccessInfo TBAAInfo,
3235                          bool isInit = false, bool isNontemporal = false);
3236 
3237   /// EmitStoreOfScalar - Store a scalar value to an address, taking
3238   /// care to appropriately convert from the memory representation to
3239   /// the LLVM value representation.  The l-value must be a simple
3240   /// l-value.  The isInit flag indicates whether this is an initialization.
3241   /// If so, atomic qualifiers are ignored and the store is always non-atomic.
3242   void EmitStoreOfScalar(llvm::Value *value, LValue lvalue, bool isInit=false);
3243 
3244   /// EmitLoadOfLValue - Given an expression that represents a value lvalue,
3245   /// this method emits the address of the lvalue, then loads the result as an
3246   /// rvalue, returning the rvalue.
3247   RValue EmitLoadOfLValue(LValue V, SourceLocation Loc);
3248   RValue EmitLoadOfExtVectorElementLValue(LValue V);
3249   RValue EmitLoadOfBitfieldLValue(LValue LV, SourceLocation Loc);
3250   RValue EmitLoadOfGlobalRegLValue(LValue LV);
3251 
3252   /// EmitStoreThroughLValue - Store the specified rvalue into the specified
3253   /// lvalue, where both are guaranteed to the have the same type, and that type
3254   /// is 'Ty'.
3255   void EmitStoreThroughLValue(RValue Src, LValue Dst, bool isInit = false);
3256   void EmitStoreThroughExtVectorComponentLValue(RValue Src, LValue Dst);
3257   void EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst);
3258 
3259   /// EmitStoreThroughBitfieldLValue - Store Src into Dst with same constraints
3260   /// as EmitStoreThroughLValue.
3261   ///
3262   /// \param Result [out] - If non-null, this will be set to a Value* for the
3263   /// bit-field contents after the store, appropriate for use as the result of
3264   /// an assignment to the bit-field.
3265   void EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
3266                                       llvm::Value **Result=nullptr);
3267 
3268   /// Emit an l-value for an assignment (simple or compound) of complex type.
3269   LValue EmitComplexAssignmentLValue(const BinaryOperator *E);
3270   LValue EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E);
3271   LValue EmitScalarCompoundAssignWithComplex(const CompoundAssignOperator *E,
3272                                              llvm::Value *&Result);
3273 
3274   // Note: only available for agg return types
3275   LValue EmitBinaryOperatorLValue(const BinaryOperator *E);
3276   LValue EmitCompoundAssignmentLValue(const CompoundAssignOperator *E);
3277   // Note: only available for agg return types
3278   LValue EmitCallExprLValue(const CallExpr *E);
3279   // Note: only available for agg return types
3280   LValue EmitVAArgExprLValue(const VAArgExpr *E);
3281   LValue EmitDeclRefLValue(const DeclRefExpr *E);
3282   LValue EmitStringLiteralLValue(const StringLiteral *E);
3283   LValue EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E);
3284   LValue EmitPredefinedLValue(const PredefinedExpr *E);
3285   LValue EmitUnaryOpLValue(const UnaryOperator *E);
3286   LValue EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
3287                                 bool Accessed = false);
3288   LValue EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
3289                                  bool IsLowerBound = true);
3290   LValue EmitExtVectorElementExpr(const ExtVectorElementExpr *E);
3291   LValue EmitMemberExpr(const MemberExpr *E);
3292   LValue EmitObjCIsaExpr(const ObjCIsaExpr *E);
3293   LValue EmitCompoundLiteralLValue(const CompoundLiteralExpr *E);
3294   LValue EmitInitListLValue(const InitListExpr *E);
3295   LValue EmitConditionalOperatorLValue(const AbstractConditionalOperator *E);
3296   LValue EmitCastLValue(const CastExpr *E);
3297   LValue EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E);
3298   LValue EmitOpaqueValueLValue(const OpaqueValueExpr *e);
3299 
3300   Address EmitExtVectorElementLValue(LValue V);
3301 
3302   RValue EmitRValueForField(LValue LV, const FieldDecl *FD, SourceLocation Loc);
3303 
3304   Address EmitArrayToPointerDecay(const Expr *Array,
3305                                   LValueBaseInfo *BaseInfo = nullptr,
3306                                   TBAAAccessInfo *TBAAInfo = nullptr);
3307 
3308   class ConstantEmission {
3309     llvm::PointerIntPair<llvm::Constant*, 1, bool> ValueAndIsReference;
3310     ConstantEmission(llvm::Constant *C, bool isReference)
3311       : ValueAndIsReference(C, isReference) {}
3312   public:
3313     ConstantEmission() {}
3314     static ConstantEmission forReference(llvm::Constant *C) {
3315       return ConstantEmission(C, true);
3316     }
3317     static ConstantEmission forValue(llvm::Constant *C) {
3318       return ConstantEmission(C, false);
3319     }
3320 
3321     explicit operator bool() const {
3322       return ValueAndIsReference.getOpaqueValue() != nullptr;
3323     }
3324 
3325     bool isReference() const { return ValueAndIsReference.getInt(); }
3326     LValue getReferenceLValue(CodeGenFunction &CGF, Expr *refExpr) const {
3327       assert(isReference());
3328       return CGF.MakeNaturalAlignAddrLValue(ValueAndIsReference.getPointer(),
3329                                             refExpr->getType());
3330     }
3331 
3332     llvm::Constant *getValue() const {
3333       assert(!isReference());
3334       return ValueAndIsReference.getPointer();
3335     }
3336   };
3337 
3338   ConstantEmission tryEmitAsConstant(DeclRefExpr *refExpr);
3339   ConstantEmission tryEmitAsConstant(const MemberExpr *ME);
3340 
3341   RValue EmitPseudoObjectRValue(const PseudoObjectExpr *e,
3342                                 AggValueSlot slot = AggValueSlot::ignored());
3343   LValue EmitPseudoObjectLValue(const PseudoObjectExpr *e);
3344 
3345   llvm::Value *EmitIvarOffset(const ObjCInterfaceDecl *Interface,
3346                               const ObjCIvarDecl *Ivar);
3347   LValue EmitLValueForField(LValue Base, const FieldDecl* Field);
3348   LValue EmitLValueForLambdaField(const FieldDecl *Field);
3349 
3350   /// EmitLValueForFieldInitialization - Like EmitLValueForField, except that
3351   /// if the Field is a reference, this will return the address of the reference
3352   /// and not the address of the value stored in the reference.
3353   LValue EmitLValueForFieldInitialization(LValue Base,
3354                                           const FieldDecl* Field);
3355 
3356   LValue EmitLValueForIvar(QualType ObjectTy,
3357                            llvm::Value* Base, const ObjCIvarDecl *Ivar,
3358                            unsigned CVRQualifiers);
3359 
3360   LValue EmitCXXConstructLValue(const CXXConstructExpr *E);
3361   LValue EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E);
3362   LValue EmitLambdaLValue(const LambdaExpr *E);
3363   LValue EmitCXXTypeidLValue(const CXXTypeidExpr *E);
3364   LValue EmitCXXUuidofLValue(const CXXUuidofExpr *E);
3365 
3366   LValue EmitObjCMessageExprLValue(const ObjCMessageExpr *E);
3367   LValue EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E);
3368   LValue EmitStmtExprLValue(const StmtExpr *E);
3369   LValue EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E);
3370   LValue EmitObjCSelectorLValue(const ObjCSelectorExpr *E);
3371   void   EmitDeclRefExprDbgValue(const DeclRefExpr *E, const APValue &Init);
3372 
3373   //===--------------------------------------------------------------------===//
3374   //                         Scalar Expression Emission
3375   //===--------------------------------------------------------------------===//
3376 
3377   /// EmitCall - Generate a call of the given function, expecting the given
3378   /// result type, and using the given argument list which specifies both the
3379   /// LLVM arguments and the types they were derived from.
3380   RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee,
3381                   ReturnValueSlot ReturnValue, const CallArgList &Args,
3382                   llvm::Instruction **callOrInvoke, SourceLocation Loc);
3383   RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee,
3384                   ReturnValueSlot ReturnValue, const CallArgList &Args,
3385                   llvm::Instruction **callOrInvoke = nullptr) {
3386     return EmitCall(CallInfo, Callee, ReturnValue, Args, callOrInvoke,
3387                     SourceLocation());
3388   }
3389   RValue EmitCall(QualType FnType, const CGCallee &Callee, const CallExpr *E,
3390                   ReturnValueSlot ReturnValue, llvm::Value *Chain = nullptr);
3391   RValue EmitCallExpr(const CallExpr *E,
3392                       ReturnValueSlot ReturnValue = ReturnValueSlot());
3393   RValue EmitSimpleCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue);
3394   CGCallee EmitCallee(const Expr *E);
3395 
3396   void checkTargetFeatures(const CallExpr *E, const FunctionDecl *TargetDecl);
3397 
3398   llvm::CallInst *EmitRuntimeCall(llvm::Value *callee,
3399                                   const Twine &name = "");
3400   llvm::CallInst *EmitRuntimeCall(llvm::Value *callee,
3401                                   ArrayRef<llvm::Value*> args,
3402                                   const Twine &name = "");
3403   llvm::CallInst *EmitNounwindRuntimeCall(llvm::Value *callee,
3404                                           const Twine &name = "");
3405   llvm::CallInst *EmitNounwindRuntimeCall(llvm::Value *callee,
3406                                           ArrayRef<llvm::Value*> args,
3407                                           const Twine &name = "");
3408 
3409   SmallVector<llvm::OperandBundleDef, 1>
3410   getBundlesForFunclet(llvm::Value *Callee);
3411 
3412   llvm::CallSite EmitCallOrInvoke(llvm::Value *Callee,
3413                                   ArrayRef<llvm::Value *> Args,
3414                                   const Twine &Name = "");
3415   llvm::CallSite EmitRuntimeCallOrInvoke(llvm::Value *callee,
3416                                          ArrayRef<llvm::Value*> args,
3417                                          const Twine &name = "");
3418   llvm::CallSite EmitRuntimeCallOrInvoke(llvm::Value *callee,
3419                                          const Twine &name = "");
3420   void EmitNoreturnRuntimeCallOrInvoke(llvm::Value *callee,
3421                                        ArrayRef<llvm::Value*> args);
3422 
3423   CGCallee BuildAppleKextVirtualCall(const CXXMethodDecl *MD,
3424                                      NestedNameSpecifier *Qual,
3425                                      llvm::Type *Ty);
3426 
3427   CGCallee BuildAppleKextVirtualDestructorCall(const CXXDestructorDecl *DD,
3428                                                CXXDtorType Type,
3429                                                const CXXRecordDecl *RD);
3430 
3431   // These functions emit calls to the special functions of non-trivial C
3432   // structs.
3433   void defaultInitNonTrivialCStructVar(LValue Dst);
3434   void callCStructDefaultConstructor(LValue Dst);
3435   void callCStructDestructor(LValue Dst);
3436   void callCStructCopyConstructor(LValue Dst, LValue Src);
3437   void callCStructMoveConstructor(LValue Dst, LValue Src);
3438   void callCStructCopyAssignmentOperator(LValue Dst, LValue Src);
3439   void callCStructMoveAssignmentOperator(LValue Dst, LValue Src);
3440 
3441   RValue
3442   EmitCXXMemberOrOperatorCall(const CXXMethodDecl *Method,
3443                               const CGCallee &Callee,
3444                               ReturnValueSlot ReturnValue, llvm::Value *This,
3445                               llvm::Value *ImplicitParam,
3446                               QualType ImplicitParamTy, const CallExpr *E,
3447                               CallArgList *RtlArgs);
3448   RValue EmitCXXDestructorCall(const CXXDestructorDecl *DD,
3449                                const CGCallee &Callee,
3450                                llvm::Value *This, llvm::Value *ImplicitParam,
3451                                QualType ImplicitParamTy, const CallExpr *E,
3452                                StructorType Type);
3453   RValue EmitCXXMemberCallExpr(const CXXMemberCallExpr *E,
3454                                ReturnValueSlot ReturnValue);
3455   RValue EmitCXXMemberOrOperatorMemberCallExpr(const CallExpr *CE,
3456                                                const CXXMethodDecl *MD,
3457                                                ReturnValueSlot ReturnValue,
3458                                                bool HasQualifier,
3459                                                NestedNameSpecifier *Qualifier,
3460                                                bool IsArrow, const Expr *Base);
3461   // Compute the object pointer.
3462   Address EmitCXXMemberDataPointerAddress(const Expr *E, Address base,
3463                                           llvm::Value *memberPtr,
3464                                           const MemberPointerType *memberPtrType,
3465                                           LValueBaseInfo *BaseInfo = nullptr,
3466                                           TBAAAccessInfo *TBAAInfo = nullptr);
3467   RValue EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
3468                                       ReturnValueSlot ReturnValue);
3469 
3470   RValue EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E,
3471                                        const CXXMethodDecl *MD,
3472                                        ReturnValueSlot ReturnValue);
3473   RValue EmitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E);
3474 
3475   RValue EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E,
3476                                 ReturnValueSlot ReturnValue);
3477 
3478   RValue EmitNVPTXDevicePrintfCallExpr(const CallExpr *E,
3479                                        ReturnValueSlot ReturnValue);
3480 
3481   RValue EmitBuiltinExpr(const FunctionDecl *FD,
3482                          unsigned BuiltinID, const CallExpr *E,
3483                          ReturnValueSlot ReturnValue);
3484 
3485   /// Emit IR for __builtin_os_log_format.
3486   RValue emitBuiltinOSLogFormat(const CallExpr &E);
3487 
3488   llvm::Function *generateBuiltinOSLogHelperFunction(
3489       const analyze_os_log::OSLogBufferLayout &Layout,
3490       CharUnits BufferAlignment);
3491 
3492   RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue);
3493 
3494   /// EmitTargetBuiltinExpr - Emit the given builtin call. Returns 0 if the call
3495   /// is unhandled by the current target.
3496   llvm::Value *EmitTargetBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3497 
3498   llvm::Value *EmitAArch64CompareBuiltinExpr(llvm::Value *Op, llvm::Type *Ty,
3499                                              const llvm::CmpInst::Predicate Fp,
3500                                              const llvm::CmpInst::Predicate Ip,
3501                                              const llvm::Twine &Name = "");
3502   llvm::Value *EmitARMBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
3503                                   llvm::Triple::ArchType Arch);
3504 
3505   llvm::Value *EmitCommonNeonBuiltinExpr(unsigned BuiltinID,
3506                                          unsigned LLVMIntrinsic,
3507                                          unsigned AltLLVMIntrinsic,
3508                                          const char *NameHint,
3509                                          unsigned Modifier,
3510                                          const CallExpr *E,
3511                                          SmallVectorImpl<llvm::Value *> &Ops,
3512                                          Address PtrOp0, Address PtrOp1,
3513                                          llvm::Triple::ArchType Arch);
3514   llvm::Function *LookupNeonLLVMIntrinsic(unsigned IntrinsicID,
3515                                           unsigned Modifier, llvm::Type *ArgTy,
3516                                           const CallExpr *E);
3517   llvm::Value *EmitNeonCall(llvm::Function *F,
3518                             SmallVectorImpl<llvm::Value*> &O,
3519                             const char *name,
3520                             unsigned shift = 0, bool rightshift = false);
3521   llvm::Value *EmitNeonSplat(llvm::Value *V, llvm::Constant *Idx);
3522   llvm::Value *EmitNeonShiftVector(llvm::Value *V, llvm::Type *Ty,
3523                                    bool negateForRightShift);
3524   llvm::Value *EmitNeonRShiftImm(llvm::Value *Vec, llvm::Value *Amt,
3525                                  llvm::Type *Ty, bool usgn, const char *name);
3526   llvm::Value *vectorWrapScalar16(llvm::Value *Op);
3527   llvm::Value *EmitAArch64BuiltinExpr(unsigned BuiltinID, const CallExpr *E,
3528                                       llvm::Triple::ArchType Arch);
3529 
3530   llvm::Value *BuildVector(ArrayRef<llvm::Value*> Ops);
3531   llvm::Value *EmitX86BuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3532   llvm::Value *EmitPPCBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3533   llvm::Value *EmitAMDGPUBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3534   llvm::Value *EmitSystemZBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3535   llvm::Value *EmitNVPTXBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3536   llvm::Value *EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
3537                                           const CallExpr *E);
3538   llvm::Value *EmitHexagonBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
3539 
3540 private:
3541   enum class MSVCIntrin;
3542 
3543 public:
3544   llvm::Value *EmitMSVCBuiltinExpr(MSVCIntrin BuiltinID, const CallExpr *E);
3545 
3546   llvm::Value *EmitBuiltinAvailable(ArrayRef<llvm::Value *> Args);
3547 
3548   llvm::Value *EmitObjCProtocolExpr(const ObjCProtocolExpr *E);
3549   llvm::Value *EmitObjCStringLiteral(const ObjCStringLiteral *E);
3550   llvm::Value *EmitObjCBoxedExpr(const ObjCBoxedExpr *E);
3551   llvm::Value *EmitObjCArrayLiteral(const ObjCArrayLiteral *E);
3552   llvm::Value *EmitObjCDictionaryLiteral(const ObjCDictionaryLiteral *E);
3553   llvm::Value *EmitObjCCollectionLiteral(const Expr *E,
3554                                 const ObjCMethodDecl *MethodWithObjects);
3555   llvm::Value *EmitObjCSelectorExpr(const ObjCSelectorExpr *E);
3556   RValue EmitObjCMessageExpr(const ObjCMessageExpr *E,
3557                              ReturnValueSlot Return = ReturnValueSlot());
3558 
3559   /// Retrieves the default cleanup kind for an ARC cleanup.
3560   /// Except under -fobjc-arc-eh, ARC cleanups are normal-only.
3561   CleanupKind getARCCleanupKind() {
3562     return CGM.getCodeGenOpts().ObjCAutoRefCountExceptions
3563              ? NormalAndEHCleanup : NormalCleanup;
3564   }
3565 
3566   // ARC primitives.
3567   void EmitARCInitWeak(Address addr, llvm::Value *value);
3568   void EmitARCDestroyWeak(Address addr);
3569   llvm::Value *EmitARCLoadWeak(Address addr);
3570   llvm::Value *EmitARCLoadWeakRetained(Address addr);
3571   llvm::Value *EmitARCStoreWeak(Address addr, llvm::Value *value, bool ignored);
3572   void emitARCCopyAssignWeak(QualType Ty, Address DstAddr, Address SrcAddr);
3573   void emitARCMoveAssignWeak(QualType Ty, Address DstAddr, Address SrcAddr);
3574   void EmitARCCopyWeak(Address dst, Address src);
3575   void EmitARCMoveWeak(Address dst, Address src);
3576   llvm::Value *EmitARCRetainAutorelease(QualType type, llvm::Value *value);
3577   llvm::Value *EmitARCRetainAutoreleaseNonBlock(llvm::Value *value);
3578   llvm::Value *EmitARCStoreStrong(LValue lvalue, llvm::Value *value,
3579                                   bool resultIgnored);
3580   llvm::Value *EmitARCStoreStrongCall(Address addr, llvm::Value *value,
3581                                       bool resultIgnored);
3582   llvm::Value *EmitARCRetain(QualType type, llvm::Value *value);
3583   llvm::Value *EmitARCRetainNonBlock(llvm::Value *value);
3584   llvm::Value *EmitARCRetainBlock(llvm::Value *value, bool mandatory);
3585   void EmitARCDestroyStrong(Address addr, ARCPreciseLifetime_t precise);
3586   void EmitARCRelease(llvm::Value *value, ARCPreciseLifetime_t precise);
3587   llvm::Value *EmitARCAutorelease(llvm::Value *value);
3588   llvm::Value *EmitARCAutoreleaseReturnValue(llvm::Value *value);
3589   llvm::Value *EmitARCRetainAutoreleaseReturnValue(llvm::Value *value);
3590   llvm::Value *EmitARCRetainAutoreleasedReturnValue(llvm::Value *value);
3591   llvm::Value *EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value *value);
3592 
3593   std::pair<LValue,llvm::Value*>
3594   EmitARCStoreAutoreleasing(const BinaryOperator *e);
3595   std::pair<LValue,llvm::Value*>
3596   EmitARCStoreStrong(const BinaryOperator *e, bool ignored);
3597   std::pair<LValue,llvm::Value*>
3598   EmitARCStoreUnsafeUnretained(const BinaryOperator *e, bool ignored);
3599 
3600   llvm::Value *EmitObjCThrowOperand(const Expr *expr);
3601   llvm::Value *EmitObjCConsumeObject(QualType T, llvm::Value *Ptr);
3602   llvm::Value *EmitObjCExtendObjectLifetime(QualType T, llvm::Value *Ptr);
3603 
3604   llvm::Value *EmitARCExtendBlockObject(const Expr *expr);
3605   llvm::Value *EmitARCReclaimReturnedObject(const Expr *e,
3606                                             bool allowUnsafeClaim);
3607   llvm::Value *EmitARCRetainScalarExpr(const Expr *expr);
3608   llvm::Value *EmitARCRetainAutoreleaseScalarExpr(const Expr *expr);
3609   llvm::Value *EmitARCUnsafeUnretainedScalarExpr(const Expr *expr);
3610 
3611   void EmitARCIntrinsicUse(ArrayRef<llvm::Value*> values);
3612 
3613   static Destroyer destroyARCStrongImprecise;
3614   static Destroyer destroyARCStrongPrecise;
3615   static Destroyer destroyARCWeak;
3616   static Destroyer emitARCIntrinsicUse;
3617   static Destroyer destroyNonTrivialCStruct;
3618 
3619   void EmitObjCAutoreleasePoolPop(llvm::Value *Ptr);
3620   llvm::Value *EmitObjCAutoreleasePoolPush();
3621   llvm::Value *EmitObjCMRRAutoreleasePoolPush();
3622   void EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr);
3623   void EmitObjCMRRAutoreleasePoolPop(llvm::Value *Ptr);
3624 
3625   /// \brief Emits a reference binding to the passed in expression.
3626   RValue EmitReferenceBindingToExpr(const Expr *E);
3627 
3628   //===--------------------------------------------------------------------===//
3629   //                           Expression Emission
3630   //===--------------------------------------------------------------------===//
3631 
3632   // Expressions are broken into three classes: scalar, complex, aggregate.
3633 
3634   /// EmitScalarExpr - Emit the computation of the specified expression of LLVM
3635   /// scalar type, returning the result.
3636   llvm::Value *EmitScalarExpr(const Expr *E , bool IgnoreResultAssign = false);
3637 
3638   /// Emit a conversion from the specified type to the specified destination
3639   /// type, both of which are LLVM scalar types.
3640   llvm::Value *EmitScalarConversion(llvm::Value *Src, QualType SrcTy,
3641                                     QualType DstTy, SourceLocation Loc);
3642 
3643   /// Emit a conversion from the specified complex type to the specified
3644   /// destination type, where the destination type is an LLVM scalar type.
3645   llvm::Value *EmitComplexToScalarConversion(ComplexPairTy Src, QualType SrcTy,
3646                                              QualType DstTy,
3647                                              SourceLocation Loc);
3648 
3649   /// EmitAggExpr - Emit the computation of the specified expression
3650   /// of aggregate type.  The result is computed into the given slot,
3651   /// which may be null to indicate that the value is not needed.
3652   void EmitAggExpr(const Expr *E, AggValueSlot AS);
3653 
3654   /// EmitAggExprToLValue - Emit the computation of the specified expression of
3655   /// aggregate type into a temporary LValue.
3656   LValue EmitAggExprToLValue(const Expr *E);
3657 
3658   /// EmitExtendGCLifetime - Given a pointer to an Objective-C object,
3659   /// make sure it survives garbage collection until this point.
3660   void EmitExtendGCLifetime(llvm::Value *object);
3661 
3662   /// EmitComplexExpr - Emit the computation of the specified expression of
3663   /// complex type, returning the result.
3664   ComplexPairTy EmitComplexExpr(const Expr *E,
3665                                 bool IgnoreReal = false,
3666                                 bool IgnoreImag = false);
3667 
3668   /// EmitComplexExprIntoLValue - Emit the given expression of complex
3669   /// type and place its result into the specified l-value.
3670   void EmitComplexExprIntoLValue(const Expr *E, LValue dest, bool isInit);
3671 
3672   /// EmitStoreOfComplex - Store a complex number into the specified l-value.
3673   void EmitStoreOfComplex(ComplexPairTy V, LValue dest, bool isInit);
3674 
3675   /// EmitLoadOfComplex - Load a complex number from the specified l-value.
3676   ComplexPairTy EmitLoadOfComplex(LValue src, SourceLocation loc);
3677 
3678   Address emitAddrOfRealComponent(Address complex, QualType complexType);
3679   Address emitAddrOfImagComponent(Address complex, QualType complexType);
3680 
3681   /// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
3682   /// global variable that has already been created for it.  If the initializer
3683   /// has a different type than GV does, this may free GV and return a different
3684   /// one.  Otherwise it just returns GV.
3685   llvm::GlobalVariable *
3686   AddInitializerToStaticVarDecl(const VarDecl &D,
3687                                 llvm::GlobalVariable *GV);
3688 
3689 
3690   /// EmitCXXGlobalVarDeclInit - Create the initializer for a C++
3691   /// variable with global storage.
3692   void EmitCXXGlobalVarDeclInit(const VarDecl &D, llvm::Constant *DeclPtr,
3693                                 bool PerformInit);
3694 
3695   llvm::Constant *createAtExitStub(const VarDecl &VD, llvm::Constant *Dtor,
3696                                    llvm::Constant *Addr);
3697 
3698   /// Call atexit() with a function that passes the given argument to
3699   /// the given function.
3700   void registerGlobalDtorWithAtExit(const VarDecl &D, llvm::Constant *fn,
3701                                     llvm::Constant *addr);
3702 
3703   /// Call atexit() with function dtorStub.
3704   void registerGlobalDtorWithAtExit(llvm::Constant *dtorStub);
3705 
3706   /// Emit code in this function to perform a guarded variable
3707   /// initialization.  Guarded initializations are used when it's not
3708   /// possible to prove that an initialization will be done exactly
3709   /// once, e.g. with a static local variable or a static data member
3710   /// of a class template.
3711   void EmitCXXGuardedInit(const VarDecl &D, llvm::GlobalVariable *DeclPtr,
3712                           bool PerformInit);
3713 
3714   enum class GuardKind { VariableGuard, TlsGuard };
3715 
3716   /// Emit a branch to select whether or not to perform guarded initialization.
3717   void EmitCXXGuardedInitBranch(llvm::Value *NeedsInit,
3718                                 llvm::BasicBlock *InitBlock,
3719                                 llvm::BasicBlock *NoInitBlock,
3720                                 GuardKind Kind, const VarDecl *D);
3721 
3722   /// GenerateCXXGlobalInitFunc - Generates code for initializing global
3723   /// variables.
3724   void GenerateCXXGlobalInitFunc(llvm::Function *Fn,
3725                                  ArrayRef<llvm::Function *> CXXThreadLocals,
3726                                  Address Guard = Address::invalid());
3727 
3728   /// GenerateCXXGlobalDtorsFunc - Generates code for destroying global
3729   /// variables.
3730   void GenerateCXXGlobalDtorsFunc(
3731       llvm::Function *Fn,
3732       const std::vector<std::pair<llvm::WeakTrackingVH, llvm::Constant *>>
3733           &DtorsAndObjects);
3734 
3735   void GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn,
3736                                         const VarDecl *D,
3737                                         llvm::GlobalVariable *Addr,
3738                                         bool PerformInit);
3739 
3740   void EmitCXXConstructExpr(const CXXConstructExpr *E, AggValueSlot Dest);
3741 
3742   void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp);
3743 
3744   void enterFullExpression(const ExprWithCleanups *E) {
3745     if (E->getNumObjects() == 0) return;
3746     enterNonTrivialFullExpression(E);
3747   }
3748   void enterNonTrivialFullExpression(const ExprWithCleanups *E);
3749 
3750   void EmitCXXThrowExpr(const CXXThrowExpr *E, bool KeepInsertionPoint = true);
3751 
3752   void EmitLambdaExpr(const LambdaExpr *E, AggValueSlot Dest);
3753 
3754   RValue EmitAtomicExpr(AtomicExpr *E);
3755 
3756   //===--------------------------------------------------------------------===//
3757   //                         Annotations Emission
3758   //===--------------------------------------------------------------------===//
3759 
3760   /// Emit an annotation call (intrinsic or builtin).
3761   llvm::Value *EmitAnnotationCall(llvm::Value *AnnotationFn,
3762                                   llvm::Value *AnnotatedVal,
3763                                   StringRef AnnotationStr,
3764                                   SourceLocation Location);
3765 
3766   /// Emit local annotations for the local variable V, declared by D.
3767   void EmitVarAnnotations(const VarDecl *D, llvm::Value *V);
3768 
3769   /// Emit field annotations for the given field & value. Returns the
3770   /// annotation result.
3771   Address EmitFieldAnnotations(const FieldDecl *D, Address V);
3772 
3773   //===--------------------------------------------------------------------===//
3774   //                             Internal Helpers
3775   //===--------------------------------------------------------------------===//
3776 
3777   /// ContainsLabel - Return true if the statement contains a label in it.  If
3778   /// this statement is not executed normally, it not containing a label means
3779   /// that we can just remove the code.
3780   static bool ContainsLabel(const Stmt *S, bool IgnoreCaseStmts = false);
3781 
3782   /// containsBreak - Return true if the statement contains a break out of it.
3783   /// If the statement (recursively) contains a switch or loop with a break
3784   /// inside of it, this is fine.
3785   static bool containsBreak(const Stmt *S);
3786 
3787   /// Determine if the given statement might introduce a declaration into the
3788   /// current scope, by being a (possibly-labelled) DeclStmt.
3789   static bool mightAddDeclToScope(const Stmt *S);
3790 
3791   /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
3792   /// to a constant, or if it does but contains a label, return false.  If it
3793   /// constant folds return true and set the boolean result in Result.
3794   bool ConstantFoldsToSimpleInteger(const Expr *Cond, bool &Result,
3795                                     bool AllowLabels = false);
3796 
3797   /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
3798   /// to a constant, or if it does but contains a label, return false.  If it
3799   /// constant folds return true and set the folded value.
3800   bool ConstantFoldsToSimpleInteger(const Expr *Cond, llvm::APSInt &Result,
3801                                     bool AllowLabels = false);
3802 
3803   /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an
3804   /// if statement) to the specified blocks.  Based on the condition, this might
3805   /// try to simplify the codegen of the conditional based on the branch.
3806   /// TrueCount should be the number of times we expect the condition to
3807   /// evaluate to true based on PGO data.
3808   void EmitBranchOnBoolExpr(const Expr *Cond, llvm::BasicBlock *TrueBlock,
3809                             llvm::BasicBlock *FalseBlock, uint64_t TrueCount);
3810 
3811   /// Given an assignment `*LHS = RHS`, emit a test that checks if \p RHS is
3812   /// nonnull, if \p LHS is marked _Nonnull.
3813   void EmitNullabilityCheck(LValue LHS, llvm::Value *RHS, SourceLocation Loc);
3814 
3815   /// An enumeration which makes it easier to specify whether or not an
3816   /// operation is a subtraction.
3817   enum { NotSubtraction = false, IsSubtraction = true };
3818 
3819   /// Same as IRBuilder::CreateInBoundsGEP, but additionally emits a check to
3820   /// detect undefined behavior when the pointer overflow sanitizer is enabled.
3821   /// \p SignedIndices indicates whether any of the GEP indices are signed.
3822   /// \p IsSubtraction indicates whether the expression used to form the GEP
3823   /// is a subtraction.
3824   llvm::Value *EmitCheckedInBoundsGEP(llvm::Value *Ptr,
3825                                       ArrayRef<llvm::Value *> IdxList,
3826                                       bool SignedIndices,
3827                                       bool IsSubtraction,
3828                                       SourceLocation Loc,
3829                                       const Twine &Name = "");
3830 
3831   /// Specifies which type of sanitizer check to apply when handling a
3832   /// particular builtin.
3833   enum BuiltinCheckKind {
3834     BCK_CTZPassedZero,
3835     BCK_CLZPassedZero,
3836   };
3837 
3838   /// Emits an argument for a call to a builtin. If the builtin sanitizer is
3839   /// enabled, a runtime check specified by \p Kind is also emitted.
3840   llvm::Value *EmitCheckedArgForBuiltin(const Expr *E, BuiltinCheckKind Kind);
3841 
3842   /// \brief Emit a description of a type in a format suitable for passing to
3843   /// a runtime sanitizer handler.
3844   llvm::Constant *EmitCheckTypeDescriptor(QualType T);
3845 
3846   /// \brief Convert a value into a format suitable for passing to a runtime
3847   /// sanitizer handler.
3848   llvm::Value *EmitCheckValue(llvm::Value *V);
3849 
3850   /// \brief Emit a description of a source location in a format suitable for
3851   /// passing to a runtime sanitizer handler.
3852   llvm::Constant *EmitCheckSourceLocation(SourceLocation Loc);
3853 
3854   /// \brief Create a basic block that will call a handler function in a
3855   /// sanitizer runtime with the provided arguments, and create a conditional
3856   /// branch to it.
3857   void EmitCheck(ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
3858                  SanitizerHandler Check, ArrayRef<llvm::Constant *> StaticArgs,
3859                  ArrayRef<llvm::Value *> DynamicArgs);
3860 
3861   /// \brief Emit a slow path cross-DSO CFI check which calls __cfi_slowpath
3862   /// if Cond if false.
3863   void EmitCfiSlowPathCheck(SanitizerMask Kind, llvm::Value *Cond,
3864                             llvm::ConstantInt *TypeId, llvm::Value *Ptr,
3865                             ArrayRef<llvm::Constant *> StaticArgs);
3866 
3867   /// Emit a reached-unreachable diagnostic if \p Loc is valid and runtime
3868   /// checking is enabled. Otherwise, just emit an unreachable instruction.
3869   void EmitUnreachable(SourceLocation Loc);
3870 
3871   /// \brief Create a basic block that will call the trap intrinsic, and emit a
3872   /// conditional branch to it, for the -ftrapv checks.
3873   void EmitTrapCheck(llvm::Value *Checked);
3874 
3875   /// \brief Emit a call to trap or debugtrap and attach function attribute
3876   /// "trap-func-name" if specified.
3877   llvm::CallInst *EmitTrapCall(llvm::Intrinsic::ID IntrID);
3878 
3879   /// \brief Emit a stub for the cross-DSO CFI check function.
3880   void EmitCfiCheckStub();
3881 
3882   /// \brief Emit a cross-DSO CFI failure handling function.
3883   void EmitCfiCheckFail();
3884 
3885   /// \brief Create a check for a function parameter that may potentially be
3886   /// declared as non-null.
3887   void EmitNonNullArgCheck(RValue RV, QualType ArgType, SourceLocation ArgLoc,
3888                            AbstractCallee AC, unsigned ParmNum);
3889 
3890   /// EmitCallArg - Emit a single call argument.
3891   void EmitCallArg(CallArgList &args, const Expr *E, QualType ArgType);
3892 
3893   /// EmitDelegateCallArg - We are performing a delegate call; that
3894   /// is, the current function is delegating to another one.  Produce
3895   /// a r-value suitable for passing the given parameter.
3896   void EmitDelegateCallArg(CallArgList &args, const VarDecl *param,
3897                            SourceLocation loc);
3898 
3899   /// SetFPAccuracy - Set the minimum required accuracy of the given floating
3900   /// point operation, expressed as the maximum relative error in ulp.
3901   void SetFPAccuracy(llvm::Value *Val, float Accuracy);
3902 
3903 private:
3904   llvm::MDNode *getRangeForLoadFromType(QualType Ty);
3905   void EmitReturnOfRValue(RValue RV, QualType Ty);
3906 
3907   void deferPlaceholderReplacement(llvm::Instruction *Old, llvm::Value *New);
3908 
3909   llvm::SmallVector<std::pair<llvm::Instruction *, llvm::Value *>, 4>
3910   DeferredReplacements;
3911 
3912   /// Set the address of a local variable.
3913   void setAddrOfLocalVar(const VarDecl *VD, Address Addr) {
3914     assert(!LocalDeclMap.count(VD) && "Decl already exists in LocalDeclMap!");
3915     LocalDeclMap.insert({VD, Addr});
3916   }
3917 
3918   /// ExpandTypeFromArgs - Reconstruct a structure of type \arg Ty
3919   /// from function arguments into \arg Dst. See ABIArgInfo::Expand.
3920   ///
3921   /// \param AI - The first function argument of the expansion.
3922   void ExpandTypeFromArgs(QualType Ty, LValue Dst,
3923                           SmallVectorImpl<llvm::Value *>::iterator &AI);
3924 
3925   /// ExpandTypeToArgs - Expand an CallArg \arg Arg, with the LLVM type for \arg
3926   /// Ty, into individual arguments on the provided vector \arg IRCallArgs,
3927   /// starting at index \arg IRCallArgPos. See ABIArgInfo::Expand.
3928   void ExpandTypeToArgs(QualType Ty, CallArg Arg, llvm::FunctionType *IRFuncTy,
3929                         SmallVectorImpl<llvm::Value *> &IRCallArgs,
3930                         unsigned &IRCallArgPos);
3931 
3932   llvm::Value* EmitAsmInput(const TargetInfo::ConstraintInfo &Info,
3933                             const Expr *InputExpr, std::string &ConstraintStr);
3934 
3935   llvm::Value* EmitAsmInputLValue(const TargetInfo::ConstraintInfo &Info,
3936                                   LValue InputValue, QualType InputType,
3937                                   std::string &ConstraintStr,
3938                                   SourceLocation Loc);
3939 
3940   /// \brief Attempts to statically evaluate the object size of E. If that
3941   /// fails, emits code to figure the size of E out for us. This is
3942   /// pass_object_size aware.
3943   ///
3944   /// If EmittedExpr is non-null, this will use that instead of re-emitting E.
3945   llvm::Value *evaluateOrEmitBuiltinObjectSize(const Expr *E, unsigned Type,
3946                                                llvm::IntegerType *ResType,
3947                                                llvm::Value *EmittedE);
3948 
3949   /// \brief Emits the size of E, as required by __builtin_object_size. This
3950   /// function is aware of pass_object_size parameters, and will act accordingly
3951   /// if E is a parameter with the pass_object_size attribute.
3952   llvm::Value *emitBuiltinObjectSize(const Expr *E, unsigned Type,
3953                                      llvm::IntegerType *ResType,
3954                                      llvm::Value *EmittedE);
3955 
3956 public:
3957 #ifndef NDEBUG
3958   // Determine whether the given argument is an Objective-C method
3959   // that may have type parameters in its signature.
3960   static bool isObjCMethodWithTypeParams(const ObjCMethodDecl *method) {
3961     const DeclContext *dc = method->getDeclContext();
3962     if (const ObjCInterfaceDecl *classDecl= dyn_cast<ObjCInterfaceDecl>(dc)) {
3963       return classDecl->getTypeParamListAsWritten();
3964     }
3965 
3966     if (const ObjCCategoryDecl *catDecl = dyn_cast<ObjCCategoryDecl>(dc)) {
3967       return catDecl->getTypeParamList();
3968     }
3969 
3970     return false;
3971   }
3972 
3973   template<typename T>
3974   static bool isObjCMethodWithTypeParams(const T *) { return false; }
3975 #endif
3976 
3977   enum class EvaluationOrder {
3978     ///! No language constraints on evaluation order.
3979     Default,
3980     ///! Language semantics require left-to-right evaluation.
3981     ForceLeftToRight,
3982     ///! Language semantics require right-to-left evaluation.
3983     ForceRightToLeft
3984   };
3985 
3986   /// EmitCallArgs - Emit call arguments for a function.
3987   template <typename T>
3988   void EmitCallArgs(CallArgList &Args, const T *CallArgTypeInfo,
3989                     llvm::iterator_range<CallExpr::const_arg_iterator> ArgRange,
3990                     AbstractCallee AC = AbstractCallee(),
3991                     unsigned ParamsToSkip = 0,
3992                     EvaluationOrder Order = EvaluationOrder::Default) {
3993     SmallVector<QualType, 16> ArgTypes;
3994     CallExpr::const_arg_iterator Arg = ArgRange.begin();
3995 
3996     assert((ParamsToSkip == 0 || CallArgTypeInfo) &&
3997            "Can't skip parameters if type info is not provided");
3998     if (CallArgTypeInfo) {
3999 #ifndef NDEBUG
4000       bool isGenericMethod = isObjCMethodWithTypeParams(CallArgTypeInfo);
4001 #endif
4002 
4003       // First, use the argument types that the type info knows about
4004       for (auto I = CallArgTypeInfo->param_type_begin() + ParamsToSkip,
4005                 E = CallArgTypeInfo->param_type_end();
4006            I != E; ++I, ++Arg) {
4007         assert(Arg != ArgRange.end() && "Running over edge of argument list!");
4008         assert((isGenericMethod ||
4009                 ((*I)->isVariablyModifiedType() ||
4010                  (*I).getNonReferenceType()->isObjCRetainableType() ||
4011                  getContext()
4012                          .getCanonicalType((*I).getNonReferenceType())
4013                          .getTypePtr() ==
4014                      getContext()
4015                          .getCanonicalType((*Arg)->getType())
4016                          .getTypePtr())) &&
4017                "type mismatch in call argument!");
4018         ArgTypes.push_back(*I);
4019       }
4020     }
4021 
4022     // Either we've emitted all the call args, or we have a call to variadic
4023     // function.
4024     assert((Arg == ArgRange.end() || !CallArgTypeInfo ||
4025             CallArgTypeInfo->isVariadic()) &&
4026            "Extra arguments in non-variadic function!");
4027 
4028     // If we still have any arguments, emit them using the type of the argument.
4029     for (auto *A : llvm::make_range(Arg, ArgRange.end()))
4030       ArgTypes.push_back(CallArgTypeInfo ? getVarArgType(A) : A->getType());
4031 
4032     EmitCallArgs(Args, ArgTypes, ArgRange, AC, ParamsToSkip, Order);
4033   }
4034 
4035   void EmitCallArgs(CallArgList &Args, ArrayRef<QualType> ArgTypes,
4036                     llvm::iterator_range<CallExpr::const_arg_iterator> ArgRange,
4037                     AbstractCallee AC = AbstractCallee(),
4038                     unsigned ParamsToSkip = 0,
4039                     EvaluationOrder Order = EvaluationOrder::Default);
4040 
4041   /// EmitPointerWithAlignment - Given an expression with a pointer type,
4042   /// emit the value and compute our best estimate of the alignment of the
4043   /// pointee.
4044   ///
4045   /// \param BaseInfo - If non-null, this will be initialized with
4046   /// information about the source of the alignment and the may-alias
4047   /// attribute.  Note that this function will conservatively fall back on
4048   /// the type when it doesn't recognize the expression and may-alias will
4049   /// be set to false.
4050   ///
4051   /// One reasonable way to use this information is when there's a language
4052   /// guarantee that the pointer must be aligned to some stricter value, and
4053   /// we're simply trying to ensure that sufficiently obvious uses of under-
4054   /// aligned objects don't get miscompiled; for example, a placement new
4055   /// into the address of a local variable.  In such a case, it's quite
4056   /// reasonable to just ignore the returned alignment when it isn't from an
4057   /// explicit source.
4058   Address EmitPointerWithAlignment(const Expr *Addr,
4059                                    LValueBaseInfo *BaseInfo = nullptr,
4060                                    TBAAAccessInfo *TBAAInfo = nullptr);
4061 
4062   /// If \p E references a parameter with pass_object_size info or a constant
4063   /// array size modifier, emit the object size divided by the size of \p EltTy.
4064   /// Otherwise return null.
4065   llvm::Value *LoadPassedObjectSize(const Expr *E, QualType EltTy);
4066 
4067   void EmitSanitizerStatReport(llvm::SanitizerStatKind SSK);
4068 
4069   struct MultiVersionResolverOption {
4070     llvm::Function *Function;
4071     TargetAttr::ParsedTargetAttr ParsedAttribute;
4072     unsigned Priority;
4073     MultiVersionResolverOption(const TargetInfo &TargInfo, llvm::Function *F,
4074                                const clang::TargetAttr::ParsedTargetAttr &PT)
4075         : Function(F), ParsedAttribute(PT), Priority(0u) {
4076       for (StringRef Feat : PT.Features)
4077         Priority = std::max(Priority,
4078                             TargInfo.multiVersionSortPriority(Feat.substr(1)));
4079 
4080       if (!PT.Architecture.empty())
4081         Priority = std::max(Priority,
4082                             TargInfo.multiVersionSortPriority(PT.Architecture));
4083     }
4084 
4085     bool operator>(const MultiVersionResolverOption &Other) const {
4086       return Priority > Other.Priority;
4087     }
4088   };
4089   void EmitMultiVersionResolver(llvm::Function *Resolver,
4090                                 ArrayRef<MultiVersionResolverOption> Options);
4091 
4092 private:
4093   QualType getVarArgType(const Expr *Arg);
4094 
4095   void EmitDeclMetadata();
4096 
4097   BlockByrefHelpers *buildByrefHelpers(llvm::StructType &byrefType,
4098                                   const AutoVarEmission &emission);
4099 
4100   void AddObjCARCExceptionMetadata(llvm::Instruction *Inst);
4101 
4102   llvm::Value *GetValueForARMHint(unsigned BuiltinID);
4103   llvm::Value *EmitX86CpuIs(const CallExpr *E);
4104   llvm::Value *EmitX86CpuIs(StringRef CPUStr);
4105   llvm::Value *EmitX86CpuSupports(const CallExpr *E);
4106   llvm::Value *EmitX86CpuSupports(ArrayRef<StringRef> FeatureStrs);
4107   llvm::Value *EmitX86CpuInit();
4108   llvm::Value *FormResolverCondition(const MultiVersionResolverOption &RO);
4109 };
4110 
4111 /// Helper class with most of the code for saving a value for a
4112 /// conditional expression cleanup.
4113 struct DominatingLLVMValue {
4114   typedef llvm::PointerIntPair<llvm::Value*, 1, bool> saved_type;
4115 
4116   /// Answer whether the given value needs extra work to be saved.
4117   static bool needsSaving(llvm::Value *value) {
4118     // If it's not an instruction, we don't need to save.
4119     if (!isa<llvm::Instruction>(value)) return false;
4120 
4121     // If it's an instruction in the entry block, we don't need to save.
4122     llvm::BasicBlock *block = cast<llvm::Instruction>(value)->getParent();
4123     return (block != &block->getParent()->getEntryBlock());
4124   }
4125 
4126   /// Try to save the given value.
4127   static saved_type save(CodeGenFunction &CGF, llvm::Value *value) {
4128     if (!needsSaving(value)) return saved_type(value, false);
4129 
4130     // Otherwise, we need an alloca.
4131     auto align = CharUnits::fromQuantity(
4132               CGF.CGM.getDataLayout().getPrefTypeAlignment(value->getType()));
4133     Address alloca =
4134       CGF.CreateTempAlloca(value->getType(), align, "cond-cleanup.save");
4135     CGF.Builder.CreateStore(value, alloca);
4136 
4137     return saved_type(alloca.getPointer(), true);
4138   }
4139 
4140   static llvm::Value *restore(CodeGenFunction &CGF, saved_type value) {
4141     // If the value says it wasn't saved, trust that it's still dominating.
4142     if (!value.getInt()) return value.getPointer();
4143 
4144     // Otherwise, it should be an alloca instruction, as set up in save().
4145     auto alloca = cast<llvm::AllocaInst>(value.getPointer());
4146     return CGF.Builder.CreateAlignedLoad(alloca, alloca->getAlignment());
4147   }
4148 };
4149 
4150 /// A partial specialization of DominatingValue for llvm::Values that
4151 /// might be llvm::Instructions.
4152 template <class T> struct DominatingPointer<T,true> : DominatingLLVMValue {
4153   typedef T *type;
4154   static type restore(CodeGenFunction &CGF, saved_type value) {
4155     return static_cast<T*>(DominatingLLVMValue::restore(CGF, value));
4156   }
4157 };
4158 
4159 /// A specialization of DominatingValue for Address.
4160 template <> struct DominatingValue<Address> {
4161   typedef Address type;
4162 
4163   struct saved_type {
4164     DominatingLLVMValue::saved_type SavedValue;
4165     CharUnits Alignment;
4166   };
4167 
4168   static bool needsSaving(type value) {
4169     return DominatingLLVMValue::needsSaving(value.getPointer());
4170   }
4171   static saved_type save(CodeGenFunction &CGF, type value) {
4172     return { DominatingLLVMValue::save(CGF, value.getPointer()),
4173              value.getAlignment() };
4174   }
4175   static type restore(CodeGenFunction &CGF, saved_type value) {
4176     return Address(DominatingLLVMValue::restore(CGF, value.SavedValue),
4177                    value.Alignment);
4178   }
4179 };
4180 
4181 /// A specialization of DominatingValue for RValue.
4182 template <> struct DominatingValue<RValue> {
4183   typedef RValue type;
4184   class saved_type {
4185     enum Kind { ScalarLiteral, ScalarAddress, AggregateLiteral,
4186                 AggregateAddress, ComplexAddress };
4187 
4188     llvm::Value *Value;
4189     unsigned K : 3;
4190     unsigned Align : 29;
4191     saved_type(llvm::Value *v, Kind k, unsigned a = 0)
4192       : Value(v), K(k), Align(a) {}
4193 
4194   public:
4195     static bool needsSaving(RValue value);
4196     static saved_type save(CodeGenFunction &CGF, RValue value);
4197     RValue restore(CodeGenFunction &CGF);
4198 
4199     // implementations in CGCleanup.cpp
4200   };
4201 
4202   static bool needsSaving(type value) {
4203     return saved_type::needsSaving(value);
4204   }
4205   static saved_type save(CodeGenFunction &CGF, type value) {
4206     return saved_type::save(CGF, value);
4207   }
4208   static type restore(CodeGenFunction &CGF, saved_type value) {
4209     return value.restore(CGF);
4210   }
4211 };
4212 
4213 }  // end namespace CodeGen
4214 }  // end namespace clang
4215 
4216 #endif
4217