xref: /freebsd/contrib/llvm-project/clang/lib/CodeGen/CodeGenFunction.h (revision 5e801ac66d24704442eba426ed13c3effb8a34e7)
1 //===-- CodeGenFunction.h - Per-Function state for LLVM CodeGen -*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This is the internal per-function state used for llvm translation.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENFUNCTION_H
14 #define LLVM_CLANG_LIB_CODEGEN_CODEGENFUNCTION_H
15 
16 #include "CGBuilder.h"
17 #include "CGDebugInfo.h"
18 #include "CGLoopInfo.h"
19 #include "CGValue.h"
20 #include "CodeGenModule.h"
21 #include "CodeGenPGO.h"
22 #include "EHScopeStack.h"
23 #include "VarBypassDetector.h"
24 #include "clang/AST/CharUnits.h"
25 #include "clang/AST/CurrentSourceLocExprScope.h"
26 #include "clang/AST/ExprCXX.h"
27 #include "clang/AST/ExprObjC.h"
28 #include "clang/AST/ExprOpenMP.h"
29 #include "clang/AST/StmtOpenMP.h"
30 #include "clang/AST/Type.h"
31 #include "clang/Basic/ABI.h"
32 #include "clang/Basic/CapturedStmt.h"
33 #include "clang/Basic/CodeGenOptions.h"
34 #include "clang/Basic/OpenMPKinds.h"
35 #include "clang/Basic/TargetInfo.h"
36 #include "llvm/ADT/ArrayRef.h"
37 #include "llvm/ADT/DenseMap.h"
38 #include "llvm/ADT/MapVector.h"
39 #include "llvm/ADT/SmallVector.h"
40 #include "llvm/Frontend/OpenMP/OMPIRBuilder.h"
41 #include "llvm/IR/ValueHandle.h"
42 #include "llvm/Support/Debug.h"
43 #include "llvm/Transforms/Utils/SanitizerStats.h"
44 
45 namespace llvm {
46 class BasicBlock;
47 class LLVMContext;
48 class MDNode;
49 class Module;
50 class SwitchInst;
51 class Twine;
52 class Value;
53 class CanonicalLoopInfo;
54 }
55 
56 namespace clang {
57 class ASTContext;
58 class BlockDecl;
59 class CXXDestructorDecl;
60 class CXXForRangeStmt;
61 class CXXTryStmt;
62 class Decl;
63 class LabelDecl;
64 class EnumConstantDecl;
65 class FunctionDecl;
66 class FunctionProtoType;
67 class LabelStmt;
68 class ObjCContainerDecl;
69 class ObjCInterfaceDecl;
70 class ObjCIvarDecl;
71 class ObjCMethodDecl;
72 class ObjCImplementationDecl;
73 class ObjCPropertyImplDecl;
74 class TargetInfo;
75 class VarDecl;
76 class ObjCForCollectionStmt;
77 class ObjCAtTryStmt;
78 class ObjCAtThrowStmt;
79 class ObjCAtSynchronizedStmt;
80 class ObjCAutoreleasePoolStmt;
81 class OMPUseDevicePtrClause;
82 class OMPUseDeviceAddrClause;
83 class ReturnsNonNullAttr;
84 class SVETypeFlags;
85 class OMPExecutableDirective;
86 
87 namespace analyze_os_log {
88 class OSLogBufferLayout;
89 }
90 
91 namespace CodeGen {
92 class CodeGenTypes;
93 class CGCallee;
94 class CGFunctionInfo;
95 class CGRecordLayout;
96 class CGBlockInfo;
97 class CGCXXABI;
98 class BlockByrefHelpers;
99 class BlockByrefInfo;
100 class BlockFlags;
101 class BlockFieldFlags;
102 class RegionCodeGenTy;
103 class TargetCodeGenInfo;
104 struct OMPTaskDataTy;
105 struct CGCoroData;
106 
107 /// The kind of evaluation to perform on values of a particular
108 /// type.  Basically, is the code in CGExprScalar, CGExprComplex, or
109 /// CGExprAgg?
110 ///
111 /// TODO: should vectors maybe be split out into their own thing?
112 enum TypeEvaluationKind {
113   TEK_Scalar,
114   TEK_Complex,
115   TEK_Aggregate
116 };
117 
118 #define LIST_SANITIZER_CHECKS                                                  \
119   SANITIZER_CHECK(AddOverflow, add_overflow, 0)                                \
120   SANITIZER_CHECK(BuiltinUnreachable, builtin_unreachable, 0)                  \
121   SANITIZER_CHECK(CFICheckFail, cfi_check_fail, 0)                             \
122   SANITIZER_CHECK(DivremOverflow, divrem_overflow, 0)                          \
123   SANITIZER_CHECK(DynamicTypeCacheMiss, dynamic_type_cache_miss, 0)            \
124   SANITIZER_CHECK(FloatCastOverflow, float_cast_overflow, 0)                   \
125   SANITIZER_CHECK(FunctionTypeMismatch, function_type_mismatch, 1)             \
126   SANITIZER_CHECK(ImplicitConversion, implicit_conversion, 0)                  \
127   SANITIZER_CHECK(InvalidBuiltin, invalid_builtin, 0)                          \
128   SANITIZER_CHECK(InvalidObjCCast, invalid_objc_cast, 0)                       \
129   SANITIZER_CHECK(LoadInvalidValue, load_invalid_value, 0)                     \
130   SANITIZER_CHECK(MissingReturn, missing_return, 0)                            \
131   SANITIZER_CHECK(MulOverflow, mul_overflow, 0)                                \
132   SANITIZER_CHECK(NegateOverflow, negate_overflow, 0)                          \
133   SANITIZER_CHECK(NullabilityArg, nullability_arg, 0)                          \
134   SANITIZER_CHECK(NullabilityReturn, nullability_return, 1)                    \
135   SANITIZER_CHECK(NonnullArg, nonnull_arg, 0)                                  \
136   SANITIZER_CHECK(NonnullReturn, nonnull_return, 1)                            \
137   SANITIZER_CHECK(OutOfBounds, out_of_bounds, 0)                               \
138   SANITIZER_CHECK(PointerOverflow, pointer_overflow, 0)                        \
139   SANITIZER_CHECK(ShiftOutOfBounds, shift_out_of_bounds, 0)                    \
140   SANITIZER_CHECK(SubOverflow, sub_overflow, 0)                                \
141   SANITIZER_CHECK(TypeMismatch, type_mismatch, 1)                              \
142   SANITIZER_CHECK(AlignmentAssumption, alignment_assumption, 0)                \
143   SANITIZER_CHECK(VLABoundNotPositive, vla_bound_not_positive, 0)
144 
145 enum SanitizerHandler {
146 #define SANITIZER_CHECK(Enum, Name, Version) Enum,
147   LIST_SANITIZER_CHECKS
148 #undef SANITIZER_CHECK
149 };
150 
151 /// Helper class with most of the code for saving a value for a
152 /// conditional expression cleanup.
153 struct DominatingLLVMValue {
154   typedef llvm::PointerIntPair<llvm::Value*, 1, bool> saved_type;
155 
156   /// Answer whether the given value needs extra work to be saved.
157   static bool needsSaving(llvm::Value *value) {
158     // If it's not an instruction, we don't need to save.
159     if (!isa<llvm::Instruction>(value)) return false;
160 
161     // If it's an instruction in the entry block, we don't need to save.
162     llvm::BasicBlock *block = cast<llvm::Instruction>(value)->getParent();
163     return (block != &block->getParent()->getEntryBlock());
164   }
165 
166   static saved_type save(CodeGenFunction &CGF, llvm::Value *value);
167   static llvm::Value *restore(CodeGenFunction &CGF, saved_type value);
168 };
169 
170 /// A partial specialization of DominatingValue for llvm::Values that
171 /// might be llvm::Instructions.
172 template <class T> struct DominatingPointer<T,true> : DominatingLLVMValue {
173   typedef T *type;
174   static type restore(CodeGenFunction &CGF, saved_type value) {
175     return static_cast<T*>(DominatingLLVMValue::restore(CGF, value));
176   }
177 };
178 
179 /// A specialization of DominatingValue for Address.
180 template <> struct DominatingValue<Address> {
181   typedef Address type;
182 
183   struct saved_type {
184     DominatingLLVMValue::saved_type SavedValue;
185     CharUnits Alignment;
186   };
187 
188   static bool needsSaving(type value) {
189     return DominatingLLVMValue::needsSaving(value.getPointer());
190   }
191   static saved_type save(CodeGenFunction &CGF, type value) {
192     return { DominatingLLVMValue::save(CGF, value.getPointer()),
193              value.getAlignment() };
194   }
195   static type restore(CodeGenFunction &CGF, saved_type value) {
196     return Address(DominatingLLVMValue::restore(CGF, value.SavedValue),
197                    value.Alignment);
198   }
199 };
200 
201 /// A specialization of DominatingValue for RValue.
202 template <> struct DominatingValue<RValue> {
203   typedef RValue type;
204   class saved_type {
205     enum Kind { ScalarLiteral, ScalarAddress, AggregateLiteral,
206                 AggregateAddress, ComplexAddress };
207 
208     llvm::Value *Value;
209     unsigned K : 3;
210     unsigned Align : 29;
211     saved_type(llvm::Value *v, Kind k, unsigned a = 0)
212       : Value(v), K(k), Align(a) {}
213 
214   public:
215     static bool needsSaving(RValue value);
216     static saved_type save(CodeGenFunction &CGF, RValue value);
217     RValue restore(CodeGenFunction &CGF);
218 
219     // implementations in CGCleanup.cpp
220   };
221 
222   static bool needsSaving(type value) {
223     return saved_type::needsSaving(value);
224   }
225   static saved_type save(CodeGenFunction &CGF, type value) {
226     return saved_type::save(CGF, value);
227   }
228   static type restore(CodeGenFunction &CGF, saved_type value) {
229     return value.restore(CGF);
230   }
231 };
232 
233 /// CodeGenFunction - This class organizes the per-function state that is used
234 /// while generating LLVM code.
235 class CodeGenFunction : public CodeGenTypeCache {
236   CodeGenFunction(const CodeGenFunction &) = delete;
237   void operator=(const CodeGenFunction &) = delete;
238 
239   friend class CGCXXABI;
240 public:
241   /// A jump destination is an abstract label, branching to which may
242   /// require a jump out through normal cleanups.
243   struct JumpDest {
244     JumpDest() : Block(nullptr), ScopeDepth(), Index(0) {}
245     JumpDest(llvm::BasicBlock *Block,
246              EHScopeStack::stable_iterator Depth,
247              unsigned Index)
248       : Block(Block), ScopeDepth(Depth), Index(Index) {}
249 
250     bool isValid() const { return Block != nullptr; }
251     llvm::BasicBlock *getBlock() const { return Block; }
252     EHScopeStack::stable_iterator getScopeDepth() const { return ScopeDepth; }
253     unsigned getDestIndex() const { return Index; }
254 
255     // This should be used cautiously.
256     void setScopeDepth(EHScopeStack::stable_iterator depth) {
257       ScopeDepth = depth;
258     }
259 
260   private:
261     llvm::BasicBlock *Block;
262     EHScopeStack::stable_iterator ScopeDepth;
263     unsigned Index;
264   };
265 
266   CodeGenModule &CGM;  // Per-module state.
267   const TargetInfo &Target;
268 
269   // For EH/SEH outlined funclets, this field points to parent's CGF
270   CodeGenFunction *ParentCGF = nullptr;
271 
272   typedef std::pair<llvm::Value *, llvm::Value *> ComplexPairTy;
273   LoopInfoStack LoopStack;
274   CGBuilderTy Builder;
275 
276   // Stores variables for which we can't generate correct lifetime markers
277   // because of jumps.
278   VarBypassDetector Bypasses;
279 
280   /// List of recently emitted OMPCanonicalLoops.
281   ///
282   /// Since OMPCanonicalLoops are nested inside other statements (in particular
283   /// CapturedStmt generated by OMPExecutableDirective and non-perfectly nested
284   /// loops), we cannot directly call OMPEmitOMPCanonicalLoop and receive its
285   /// llvm::CanonicalLoopInfo. Instead, we call EmitStmt and any
286   /// OMPEmitOMPCanonicalLoop called by it will add its CanonicalLoopInfo to
287   /// this stack when done. Entering a new loop requires clearing this list; it
288   /// either means we start parsing a new loop nest (in which case the previous
289   /// loop nest goes out of scope) or a second loop in the same level in which
290   /// case it would be ambiguous into which of the two (or more) loops the loop
291   /// nest would extend.
292   SmallVector<llvm::CanonicalLoopInfo *, 4> OMPLoopNestStack;
293 
294   /// Number of nested loop to be consumed by the last surrounding
295   /// loop-associated directive.
296   int ExpectedOMPLoopDepth = 0;
297 
298   // CodeGen lambda for loops and support for ordered clause
299   typedef llvm::function_ref<void(CodeGenFunction &, const OMPLoopDirective &,
300                                   JumpDest)>
301       CodeGenLoopTy;
302   typedef llvm::function_ref<void(CodeGenFunction &, SourceLocation,
303                                   const unsigned, const bool)>
304       CodeGenOrderedTy;
305 
306   // Codegen lambda for loop bounds in worksharing loop constructs
307   typedef llvm::function_ref<std::pair<LValue, LValue>(
308       CodeGenFunction &, const OMPExecutableDirective &S)>
309       CodeGenLoopBoundsTy;
310 
311   // Codegen lambda for loop bounds in dispatch-based loop implementation
312   typedef llvm::function_ref<std::pair<llvm::Value *, llvm::Value *>(
313       CodeGenFunction &, const OMPExecutableDirective &S, Address LB,
314       Address UB)>
315       CodeGenDispatchBoundsTy;
316 
317   /// CGBuilder insert helper. This function is called after an
318   /// instruction is created using Builder.
319   void InsertHelper(llvm::Instruction *I, const llvm::Twine &Name,
320                     llvm::BasicBlock *BB,
321                     llvm::BasicBlock::iterator InsertPt) const;
322 
323   /// CurFuncDecl - Holds the Decl for the current outermost
324   /// non-closure context.
325   const Decl *CurFuncDecl;
326   /// CurCodeDecl - This is the inner-most code context, which includes blocks.
327   const Decl *CurCodeDecl;
328   const CGFunctionInfo *CurFnInfo;
329   QualType FnRetTy;
330   llvm::Function *CurFn = nullptr;
331 
332   /// Save Parameter Decl for coroutine.
333   llvm::SmallVector<const ParmVarDecl *, 4> FnArgs;
334 
335   // Holds coroutine data if the current function is a coroutine. We use a
336   // wrapper to manage its lifetime, so that we don't have to define CGCoroData
337   // in this header.
338   struct CGCoroInfo {
339     std::unique_ptr<CGCoroData> Data;
340     CGCoroInfo();
341     ~CGCoroInfo();
342   };
343   CGCoroInfo CurCoro;
344 
345   bool isCoroutine() const {
346     return CurCoro.Data != nullptr;
347   }
348 
349   /// CurGD - The GlobalDecl for the current function being compiled.
350   GlobalDecl CurGD;
351 
352   /// PrologueCleanupDepth - The cleanup depth enclosing all the
353   /// cleanups associated with the parameters.
354   EHScopeStack::stable_iterator PrologueCleanupDepth;
355 
356   /// ReturnBlock - Unified return block.
357   JumpDest ReturnBlock;
358 
359   /// ReturnValue - The temporary alloca to hold the return
360   /// value. This is invalid iff the function has no return value.
361   Address ReturnValue = Address::invalid();
362 
363   /// ReturnValuePointer - The temporary alloca to hold a pointer to sret.
364   /// This is invalid if sret is not in use.
365   Address ReturnValuePointer = Address::invalid();
366 
367   /// If a return statement is being visited, this holds the return statment's
368   /// result expression.
369   const Expr *RetExpr = nullptr;
370 
371   /// Return true if a label was seen in the current scope.
372   bool hasLabelBeenSeenInCurrentScope() const {
373     if (CurLexicalScope)
374       return CurLexicalScope->hasLabels();
375     return !LabelMap.empty();
376   }
377 
378   /// AllocaInsertPoint - This is an instruction in the entry block before which
379   /// we prefer to insert allocas.
380   llvm::AssertingVH<llvm::Instruction> AllocaInsertPt;
381 
382 private:
383   /// PostAllocaInsertPt - This is a place in the prologue where code can be
384   /// inserted that will be dominated by all the static allocas. This helps
385   /// achieve two things:
386   ///   1. Contiguity of all static allocas (within the prologue) is maintained.
387   ///   2. All other prologue code (which are dominated by static allocas) do
388   ///      appear in the source order immediately after all static allocas.
389   ///
390   /// PostAllocaInsertPt will be lazily created when it is *really* required.
391   llvm::AssertingVH<llvm::Instruction> PostAllocaInsertPt = nullptr;
392 
393 public:
394   /// Return PostAllocaInsertPt. If it is not yet created, then insert it
395   /// immediately after AllocaInsertPt.
396   llvm::Instruction *getPostAllocaInsertPoint() {
397     if (!PostAllocaInsertPt) {
398       assert(AllocaInsertPt &&
399              "Expected static alloca insertion point at function prologue");
400       assert(AllocaInsertPt->getParent()->isEntryBlock() &&
401              "EBB should be entry block of the current code gen function");
402       PostAllocaInsertPt = AllocaInsertPt->clone();
403       PostAllocaInsertPt->setName("postallocapt");
404       PostAllocaInsertPt->insertAfter(AllocaInsertPt);
405     }
406 
407     return PostAllocaInsertPt;
408   }
409 
410   /// API for captured statement code generation.
411   class CGCapturedStmtInfo {
412   public:
413     explicit CGCapturedStmtInfo(CapturedRegionKind K = CR_Default)
414         : Kind(K), ThisValue(nullptr), CXXThisFieldDecl(nullptr) {}
415     explicit CGCapturedStmtInfo(const CapturedStmt &S,
416                                 CapturedRegionKind K = CR_Default)
417       : Kind(K), ThisValue(nullptr), CXXThisFieldDecl(nullptr) {
418 
419       RecordDecl::field_iterator Field =
420         S.getCapturedRecordDecl()->field_begin();
421       for (CapturedStmt::const_capture_iterator I = S.capture_begin(),
422                                                 E = S.capture_end();
423            I != E; ++I, ++Field) {
424         if (I->capturesThis())
425           CXXThisFieldDecl = *Field;
426         else if (I->capturesVariable())
427           CaptureFields[I->getCapturedVar()->getCanonicalDecl()] = *Field;
428         else if (I->capturesVariableByCopy())
429           CaptureFields[I->getCapturedVar()->getCanonicalDecl()] = *Field;
430       }
431     }
432 
433     virtual ~CGCapturedStmtInfo();
434 
435     CapturedRegionKind getKind() const { return Kind; }
436 
437     virtual void setContextValue(llvm::Value *V) { ThisValue = V; }
438     // Retrieve the value of the context parameter.
439     virtual llvm::Value *getContextValue() const { return ThisValue; }
440 
441     /// Lookup the captured field decl for a variable.
442     virtual const FieldDecl *lookup(const VarDecl *VD) const {
443       return CaptureFields.lookup(VD->getCanonicalDecl());
444     }
445 
446     bool isCXXThisExprCaptured() const { return getThisFieldDecl() != nullptr; }
447     virtual FieldDecl *getThisFieldDecl() const { return CXXThisFieldDecl; }
448 
449     static bool classof(const CGCapturedStmtInfo *) {
450       return true;
451     }
452 
453     /// Emit the captured statement body.
454     virtual void EmitBody(CodeGenFunction &CGF, const Stmt *S) {
455       CGF.incrementProfileCounter(S);
456       CGF.EmitStmt(S);
457     }
458 
459     /// Get the name of the capture helper.
460     virtual StringRef getHelperName() const { return "__captured_stmt"; }
461 
462   private:
463     /// The kind of captured statement being generated.
464     CapturedRegionKind Kind;
465 
466     /// Keep the map between VarDecl and FieldDecl.
467     llvm::SmallDenseMap<const VarDecl *, FieldDecl *> CaptureFields;
468 
469     /// The base address of the captured record, passed in as the first
470     /// argument of the parallel region function.
471     llvm::Value *ThisValue;
472 
473     /// Captured 'this' type.
474     FieldDecl *CXXThisFieldDecl;
475   };
476   CGCapturedStmtInfo *CapturedStmtInfo = nullptr;
477 
478   /// RAII for correct setting/restoring of CapturedStmtInfo.
479   class CGCapturedStmtRAII {
480   private:
481     CodeGenFunction &CGF;
482     CGCapturedStmtInfo *PrevCapturedStmtInfo;
483   public:
484     CGCapturedStmtRAII(CodeGenFunction &CGF,
485                        CGCapturedStmtInfo *NewCapturedStmtInfo)
486         : CGF(CGF), PrevCapturedStmtInfo(CGF.CapturedStmtInfo) {
487       CGF.CapturedStmtInfo = NewCapturedStmtInfo;
488     }
489     ~CGCapturedStmtRAII() { CGF.CapturedStmtInfo = PrevCapturedStmtInfo; }
490   };
491 
492   /// An abstract representation of regular/ObjC call/message targets.
493   class AbstractCallee {
494     /// The function declaration of the callee.
495     const Decl *CalleeDecl;
496 
497   public:
498     AbstractCallee() : CalleeDecl(nullptr) {}
499     AbstractCallee(const FunctionDecl *FD) : CalleeDecl(FD) {}
500     AbstractCallee(const ObjCMethodDecl *OMD) : CalleeDecl(OMD) {}
501     bool hasFunctionDecl() const {
502       return isa_and_nonnull<FunctionDecl>(CalleeDecl);
503     }
504     const Decl *getDecl() const { return CalleeDecl; }
505     unsigned getNumParams() const {
506       if (const auto *FD = dyn_cast<FunctionDecl>(CalleeDecl))
507         return FD->getNumParams();
508       return cast<ObjCMethodDecl>(CalleeDecl)->param_size();
509     }
510     const ParmVarDecl *getParamDecl(unsigned I) const {
511       if (const auto *FD = dyn_cast<FunctionDecl>(CalleeDecl))
512         return FD->getParamDecl(I);
513       return *(cast<ObjCMethodDecl>(CalleeDecl)->param_begin() + I);
514     }
515   };
516 
517   /// Sanitizers enabled for this function.
518   SanitizerSet SanOpts;
519 
520   /// True if CodeGen currently emits code implementing sanitizer checks.
521   bool IsSanitizerScope = false;
522 
523   /// RAII object to set/unset CodeGenFunction::IsSanitizerScope.
524   class SanitizerScope {
525     CodeGenFunction *CGF;
526   public:
527     SanitizerScope(CodeGenFunction *CGF);
528     ~SanitizerScope();
529   };
530 
531   /// In C++, whether we are code generating a thunk.  This controls whether we
532   /// should emit cleanups.
533   bool CurFuncIsThunk = false;
534 
535   /// In ARC, whether we should autorelease the return value.
536   bool AutoreleaseResult = false;
537 
538   /// Whether we processed a Microsoft-style asm block during CodeGen. These can
539   /// potentially set the return value.
540   bool SawAsmBlock = false;
541 
542   const NamedDecl *CurSEHParent = nullptr;
543 
544   /// True if the current function is an outlined SEH helper. This can be a
545   /// finally block or filter expression.
546   bool IsOutlinedSEHHelper = false;
547 
548   /// True if CodeGen currently emits code inside presereved access index
549   /// region.
550   bool IsInPreservedAIRegion = false;
551 
552   /// True if the current statement has nomerge attribute.
553   bool InNoMergeAttributedStmt = false;
554 
555   // The CallExpr within the current statement that the musttail attribute
556   // applies to.  nullptr if there is no 'musttail' on the current statement.
557   const CallExpr *MustTailCall = nullptr;
558 
559   /// Returns true if a function must make progress, which means the
560   /// mustprogress attribute can be added.
561   bool checkIfFunctionMustProgress() {
562     if (CGM.getCodeGenOpts().getFiniteLoops() ==
563         CodeGenOptions::FiniteLoopsKind::Never)
564       return false;
565 
566     // C++11 and later guarantees that a thread eventually will do one of the
567     // following (6.9.2.3.1 in C++11):
568     // - terminate,
569     //  - make a call to a library I/O function,
570     //  - perform an access through a volatile glvalue, or
571     //  - perform a synchronization operation or an atomic operation.
572     //
573     // Hence each function is 'mustprogress' in C++11 or later.
574     return getLangOpts().CPlusPlus11;
575   }
576 
577   /// Returns true if a loop must make progress, which means the mustprogress
578   /// attribute can be added. \p HasConstantCond indicates whether the branch
579   /// condition is a known constant.
580   bool checkIfLoopMustProgress(bool HasConstantCond) {
581     if (CGM.getCodeGenOpts().getFiniteLoops() ==
582         CodeGenOptions::FiniteLoopsKind::Always)
583       return true;
584     if (CGM.getCodeGenOpts().getFiniteLoops() ==
585         CodeGenOptions::FiniteLoopsKind::Never)
586       return false;
587 
588     // If the containing function must make progress, loops also must make
589     // progress (as in C++11 and later).
590     if (checkIfFunctionMustProgress())
591       return true;
592 
593     // Now apply rules for plain C (see  6.8.5.6 in C11).
594     // Loops with constant conditions do not have to make progress in any C
595     // version.
596     if (HasConstantCond)
597       return false;
598 
599     // Loops with non-constant conditions must make progress in C11 and later.
600     return getLangOpts().C11;
601   }
602 
603   const CodeGen::CGBlockInfo *BlockInfo = nullptr;
604   llvm::Value *BlockPointer = nullptr;
605 
606   llvm::DenseMap<const VarDecl *, FieldDecl *> LambdaCaptureFields;
607   FieldDecl *LambdaThisCaptureField = nullptr;
608 
609   /// A mapping from NRVO variables to the flags used to indicate
610   /// when the NRVO has been applied to this variable.
611   llvm::DenseMap<const VarDecl *, llvm::Value *> NRVOFlags;
612 
613   EHScopeStack EHStack;
614   llvm::SmallVector<char, 256> LifetimeExtendedCleanupStack;
615   llvm::SmallVector<const JumpDest *, 2> SEHTryEpilogueStack;
616 
617   llvm::Instruction *CurrentFuncletPad = nullptr;
618 
619   class CallLifetimeEnd final : public EHScopeStack::Cleanup {
620     bool isRedundantBeforeReturn() override { return true; }
621 
622     llvm::Value *Addr;
623     llvm::Value *Size;
624 
625   public:
626     CallLifetimeEnd(Address addr, llvm::Value *size)
627         : Addr(addr.getPointer()), Size(size) {}
628 
629     void Emit(CodeGenFunction &CGF, Flags flags) override {
630       CGF.EmitLifetimeEnd(Size, Addr);
631     }
632   };
633 
634   /// Header for data within LifetimeExtendedCleanupStack.
635   struct LifetimeExtendedCleanupHeader {
636     /// The size of the following cleanup object.
637     unsigned Size;
638     /// The kind of cleanup to push: a value from the CleanupKind enumeration.
639     unsigned Kind : 31;
640     /// Whether this is a conditional cleanup.
641     unsigned IsConditional : 1;
642 
643     size_t getSize() const { return Size; }
644     CleanupKind getKind() const { return (CleanupKind)Kind; }
645     bool isConditional() const { return IsConditional; }
646   };
647 
648   /// i32s containing the indexes of the cleanup destinations.
649   Address NormalCleanupDest = Address::invalid();
650 
651   unsigned NextCleanupDestIndex = 1;
652 
653   /// EHResumeBlock - Unified block containing a call to llvm.eh.resume.
654   llvm::BasicBlock *EHResumeBlock = nullptr;
655 
656   /// The exception slot.  All landing pads write the current exception pointer
657   /// into this alloca.
658   llvm::Value *ExceptionSlot = nullptr;
659 
660   /// The selector slot.  Under the MandatoryCleanup model, all landing pads
661   /// write the current selector value into this alloca.
662   llvm::AllocaInst *EHSelectorSlot = nullptr;
663 
664   /// A stack of exception code slots. Entering an __except block pushes a slot
665   /// on the stack and leaving pops one. The __exception_code() intrinsic loads
666   /// a value from the top of the stack.
667   SmallVector<Address, 1> SEHCodeSlotStack;
668 
669   /// Value returned by __exception_info intrinsic.
670   llvm::Value *SEHInfo = nullptr;
671 
672   /// Emits a landing pad for the current EH stack.
673   llvm::BasicBlock *EmitLandingPad();
674 
675   llvm::BasicBlock *getInvokeDestImpl();
676 
677   /// Parent loop-based directive for scan directive.
678   const OMPExecutableDirective *OMPParentLoopDirectiveForScan = nullptr;
679   llvm::BasicBlock *OMPBeforeScanBlock = nullptr;
680   llvm::BasicBlock *OMPAfterScanBlock = nullptr;
681   llvm::BasicBlock *OMPScanExitBlock = nullptr;
682   llvm::BasicBlock *OMPScanDispatch = nullptr;
683   bool OMPFirstScanLoop = false;
684 
685   /// Manages parent directive for scan directives.
686   class ParentLoopDirectiveForScanRegion {
687     CodeGenFunction &CGF;
688     const OMPExecutableDirective *ParentLoopDirectiveForScan;
689 
690   public:
691     ParentLoopDirectiveForScanRegion(
692         CodeGenFunction &CGF,
693         const OMPExecutableDirective &ParentLoopDirectiveForScan)
694         : CGF(CGF),
695           ParentLoopDirectiveForScan(CGF.OMPParentLoopDirectiveForScan) {
696       CGF.OMPParentLoopDirectiveForScan = &ParentLoopDirectiveForScan;
697     }
698     ~ParentLoopDirectiveForScanRegion() {
699       CGF.OMPParentLoopDirectiveForScan = ParentLoopDirectiveForScan;
700     }
701   };
702 
703   template <class T>
704   typename DominatingValue<T>::saved_type saveValueInCond(T value) {
705     return DominatingValue<T>::save(*this, value);
706   }
707 
708   class CGFPOptionsRAII {
709   public:
710     CGFPOptionsRAII(CodeGenFunction &CGF, FPOptions FPFeatures);
711     CGFPOptionsRAII(CodeGenFunction &CGF, const Expr *E);
712     ~CGFPOptionsRAII();
713 
714   private:
715     void ConstructorHelper(FPOptions FPFeatures);
716     CodeGenFunction &CGF;
717     FPOptions OldFPFeatures;
718     llvm::fp::ExceptionBehavior OldExcept;
719     llvm::RoundingMode OldRounding;
720     Optional<CGBuilderTy::FastMathFlagGuard> FMFGuard;
721   };
722   FPOptions CurFPFeatures;
723 
724 public:
725   /// ObjCEHValueStack - Stack of Objective-C exception values, used for
726   /// rethrows.
727   SmallVector<llvm::Value*, 8> ObjCEHValueStack;
728 
729   /// A class controlling the emission of a finally block.
730   class FinallyInfo {
731     /// Where the catchall's edge through the cleanup should go.
732     JumpDest RethrowDest;
733 
734     /// A function to call to enter the catch.
735     llvm::FunctionCallee BeginCatchFn;
736 
737     /// An i1 variable indicating whether or not the @finally is
738     /// running for an exception.
739     llvm::AllocaInst *ForEHVar;
740 
741     /// An i8* variable into which the exception pointer to rethrow
742     /// has been saved.
743     llvm::AllocaInst *SavedExnVar;
744 
745   public:
746     void enter(CodeGenFunction &CGF, const Stmt *Finally,
747                llvm::FunctionCallee beginCatchFn,
748                llvm::FunctionCallee endCatchFn, llvm::FunctionCallee rethrowFn);
749     void exit(CodeGenFunction &CGF);
750   };
751 
752   /// Returns true inside SEH __try blocks.
753   bool isSEHTryScope() const { return !SEHTryEpilogueStack.empty(); }
754 
755   /// Returns true while emitting a cleanuppad.
756   bool isCleanupPadScope() const {
757     return CurrentFuncletPad && isa<llvm::CleanupPadInst>(CurrentFuncletPad);
758   }
759 
760   /// pushFullExprCleanup - Push a cleanup to be run at the end of the
761   /// current full-expression.  Safe against the possibility that
762   /// we're currently inside a conditionally-evaluated expression.
763   template <class T, class... As>
764   void pushFullExprCleanup(CleanupKind kind, As... A) {
765     // If we're not in a conditional branch, or if none of the
766     // arguments requires saving, then use the unconditional cleanup.
767     if (!isInConditionalBranch())
768       return EHStack.pushCleanup<T>(kind, A...);
769 
770     // Stash values in a tuple so we can guarantee the order of saves.
771     typedef std::tuple<typename DominatingValue<As>::saved_type...> SavedTuple;
772     SavedTuple Saved{saveValueInCond(A)...};
773 
774     typedef EHScopeStack::ConditionalCleanup<T, As...> CleanupType;
775     EHStack.pushCleanupTuple<CleanupType>(kind, Saved);
776     initFullExprCleanup();
777   }
778 
779   /// Queue a cleanup to be pushed after finishing the current full-expression,
780   /// potentially with an active flag.
781   template <class T, class... As>
782   void pushCleanupAfterFullExpr(CleanupKind Kind, As... A) {
783     if (!isInConditionalBranch())
784       return pushCleanupAfterFullExprWithActiveFlag<T>(Kind, Address::invalid(),
785                                                        A...);
786 
787     Address ActiveFlag = createCleanupActiveFlag();
788     assert(!DominatingValue<Address>::needsSaving(ActiveFlag) &&
789            "cleanup active flag should never need saving");
790 
791     typedef std::tuple<typename DominatingValue<As>::saved_type...> SavedTuple;
792     SavedTuple Saved{saveValueInCond(A)...};
793 
794     typedef EHScopeStack::ConditionalCleanup<T, As...> CleanupType;
795     pushCleanupAfterFullExprWithActiveFlag<CleanupType>(Kind, ActiveFlag, Saved);
796   }
797 
798   template <class T, class... As>
799   void pushCleanupAfterFullExprWithActiveFlag(CleanupKind Kind,
800                                               Address ActiveFlag, As... A) {
801     LifetimeExtendedCleanupHeader Header = {sizeof(T), Kind,
802                                             ActiveFlag.isValid()};
803 
804     size_t OldSize = LifetimeExtendedCleanupStack.size();
805     LifetimeExtendedCleanupStack.resize(
806         LifetimeExtendedCleanupStack.size() + sizeof(Header) + Header.Size +
807         (Header.IsConditional ? sizeof(ActiveFlag) : 0));
808 
809     static_assert(sizeof(Header) % alignof(T) == 0,
810                   "Cleanup will be allocated on misaligned address");
811     char *Buffer = &LifetimeExtendedCleanupStack[OldSize];
812     new (Buffer) LifetimeExtendedCleanupHeader(Header);
813     new (Buffer + sizeof(Header)) T(A...);
814     if (Header.IsConditional)
815       new (Buffer + sizeof(Header) + sizeof(T)) Address(ActiveFlag);
816   }
817 
818   /// Set up the last cleanup that was pushed as a conditional
819   /// full-expression cleanup.
820   void initFullExprCleanup() {
821     initFullExprCleanupWithFlag(createCleanupActiveFlag());
822   }
823 
824   void initFullExprCleanupWithFlag(Address ActiveFlag);
825   Address createCleanupActiveFlag();
826 
827   /// PushDestructorCleanup - Push a cleanup to call the
828   /// complete-object destructor of an object of the given type at the
829   /// given address.  Does nothing if T is not a C++ class type with a
830   /// non-trivial destructor.
831   void PushDestructorCleanup(QualType T, Address Addr);
832 
833   /// PushDestructorCleanup - Push a cleanup to call the
834   /// complete-object variant of the given destructor on the object at
835   /// the given address.
836   void PushDestructorCleanup(const CXXDestructorDecl *Dtor, QualType T,
837                              Address Addr);
838 
839   /// PopCleanupBlock - Will pop the cleanup entry on the stack and
840   /// process all branch fixups.
841   void PopCleanupBlock(bool FallThroughIsBranchThrough = false);
842 
843   /// DeactivateCleanupBlock - Deactivates the given cleanup block.
844   /// The block cannot be reactivated.  Pops it if it's the top of the
845   /// stack.
846   ///
847   /// \param DominatingIP - An instruction which is known to
848   ///   dominate the current IP (if set) and which lies along
849   ///   all paths of execution between the current IP and the
850   ///   the point at which the cleanup comes into scope.
851   void DeactivateCleanupBlock(EHScopeStack::stable_iterator Cleanup,
852                               llvm::Instruction *DominatingIP);
853 
854   /// ActivateCleanupBlock - Activates an initially-inactive cleanup.
855   /// Cannot be used to resurrect a deactivated cleanup.
856   ///
857   /// \param DominatingIP - An instruction which is known to
858   ///   dominate the current IP (if set) and which lies along
859   ///   all paths of execution between the current IP and the
860   ///   the point at which the cleanup comes into scope.
861   void ActivateCleanupBlock(EHScopeStack::stable_iterator Cleanup,
862                             llvm::Instruction *DominatingIP);
863 
864   /// Enters a new scope for capturing cleanups, all of which
865   /// will be executed once the scope is exited.
866   class RunCleanupsScope {
867     EHScopeStack::stable_iterator CleanupStackDepth, OldCleanupScopeDepth;
868     size_t LifetimeExtendedCleanupStackSize;
869     bool OldDidCallStackSave;
870   protected:
871     bool PerformCleanup;
872   private:
873 
874     RunCleanupsScope(const RunCleanupsScope &) = delete;
875     void operator=(const RunCleanupsScope &) = delete;
876 
877   protected:
878     CodeGenFunction& CGF;
879 
880   public:
881     /// Enter a new cleanup scope.
882     explicit RunCleanupsScope(CodeGenFunction &CGF)
883       : PerformCleanup(true), CGF(CGF)
884     {
885       CleanupStackDepth = CGF.EHStack.stable_begin();
886       LifetimeExtendedCleanupStackSize =
887           CGF.LifetimeExtendedCleanupStack.size();
888       OldDidCallStackSave = CGF.DidCallStackSave;
889       CGF.DidCallStackSave = false;
890       OldCleanupScopeDepth = CGF.CurrentCleanupScopeDepth;
891       CGF.CurrentCleanupScopeDepth = CleanupStackDepth;
892     }
893 
894     /// Exit this cleanup scope, emitting any accumulated cleanups.
895     ~RunCleanupsScope() {
896       if (PerformCleanup)
897         ForceCleanup();
898     }
899 
900     /// Determine whether this scope requires any cleanups.
901     bool requiresCleanups() const {
902       return CGF.EHStack.stable_begin() != CleanupStackDepth;
903     }
904 
905     /// Force the emission of cleanups now, instead of waiting
906     /// until this object is destroyed.
907     /// \param ValuesToReload - A list of values that need to be available at
908     /// the insertion point after cleanup emission. If cleanup emission created
909     /// a shared cleanup block, these value pointers will be rewritten.
910     /// Otherwise, they not will be modified.
911     void ForceCleanup(std::initializer_list<llvm::Value**> ValuesToReload = {}) {
912       assert(PerformCleanup && "Already forced cleanup");
913       CGF.DidCallStackSave = OldDidCallStackSave;
914       CGF.PopCleanupBlocks(CleanupStackDepth, LifetimeExtendedCleanupStackSize,
915                            ValuesToReload);
916       PerformCleanup = false;
917       CGF.CurrentCleanupScopeDepth = OldCleanupScopeDepth;
918     }
919   };
920 
921   // Cleanup stack depth of the RunCleanupsScope that was pushed most recently.
922   EHScopeStack::stable_iterator CurrentCleanupScopeDepth =
923       EHScopeStack::stable_end();
924 
925   class LexicalScope : public RunCleanupsScope {
926     SourceRange Range;
927     SmallVector<const LabelDecl*, 4> Labels;
928     LexicalScope *ParentScope;
929 
930     LexicalScope(const LexicalScope &) = delete;
931     void operator=(const LexicalScope &) = delete;
932 
933   public:
934     /// Enter a new cleanup scope.
935     explicit LexicalScope(CodeGenFunction &CGF, SourceRange Range)
936       : RunCleanupsScope(CGF), Range(Range), ParentScope(CGF.CurLexicalScope) {
937       CGF.CurLexicalScope = this;
938       if (CGDebugInfo *DI = CGF.getDebugInfo())
939         DI->EmitLexicalBlockStart(CGF.Builder, Range.getBegin());
940     }
941 
942     void addLabel(const LabelDecl *label) {
943       assert(PerformCleanup && "adding label to dead scope?");
944       Labels.push_back(label);
945     }
946 
947     /// Exit this cleanup scope, emitting any accumulated
948     /// cleanups.
949     ~LexicalScope() {
950       if (CGDebugInfo *DI = CGF.getDebugInfo())
951         DI->EmitLexicalBlockEnd(CGF.Builder, Range.getEnd());
952 
953       // If we should perform a cleanup, force them now.  Note that
954       // this ends the cleanup scope before rescoping any labels.
955       if (PerformCleanup) {
956         ApplyDebugLocation DL(CGF, Range.getEnd());
957         ForceCleanup();
958       }
959     }
960 
961     /// Force the emission of cleanups now, instead of waiting
962     /// until this object is destroyed.
963     void ForceCleanup() {
964       CGF.CurLexicalScope = ParentScope;
965       RunCleanupsScope::ForceCleanup();
966 
967       if (!Labels.empty())
968         rescopeLabels();
969     }
970 
971     bool hasLabels() const {
972       return !Labels.empty();
973     }
974 
975     void rescopeLabels();
976   };
977 
978   typedef llvm::DenseMap<const Decl *, Address> DeclMapTy;
979 
980   /// The class used to assign some variables some temporarily addresses.
981   class OMPMapVars {
982     DeclMapTy SavedLocals;
983     DeclMapTy SavedTempAddresses;
984     OMPMapVars(const OMPMapVars &) = delete;
985     void operator=(const OMPMapVars &) = delete;
986 
987   public:
988     explicit OMPMapVars() = default;
989     ~OMPMapVars() {
990       assert(SavedLocals.empty() && "Did not restored original addresses.");
991     };
992 
993     /// Sets the address of the variable \p LocalVD to be \p TempAddr in
994     /// function \p CGF.
995     /// \return true if at least one variable was set already, false otherwise.
996     bool setVarAddr(CodeGenFunction &CGF, const VarDecl *LocalVD,
997                     Address TempAddr) {
998       LocalVD = LocalVD->getCanonicalDecl();
999       // Only save it once.
1000       if (SavedLocals.count(LocalVD)) return false;
1001 
1002       // Copy the existing local entry to SavedLocals.
1003       auto it = CGF.LocalDeclMap.find(LocalVD);
1004       if (it != CGF.LocalDeclMap.end())
1005         SavedLocals.try_emplace(LocalVD, it->second);
1006       else
1007         SavedLocals.try_emplace(LocalVD, Address::invalid());
1008 
1009       // Generate the private entry.
1010       QualType VarTy = LocalVD->getType();
1011       if (VarTy->isReferenceType()) {
1012         Address Temp = CGF.CreateMemTemp(VarTy);
1013         CGF.Builder.CreateStore(TempAddr.getPointer(), Temp);
1014         TempAddr = Temp;
1015       }
1016       SavedTempAddresses.try_emplace(LocalVD, TempAddr);
1017 
1018       return true;
1019     }
1020 
1021     /// Applies new addresses to the list of the variables.
1022     /// \return true if at least one variable is using new address, false
1023     /// otherwise.
1024     bool apply(CodeGenFunction &CGF) {
1025       copyInto(SavedTempAddresses, CGF.LocalDeclMap);
1026       SavedTempAddresses.clear();
1027       return !SavedLocals.empty();
1028     }
1029 
1030     /// Restores original addresses of the variables.
1031     void restore(CodeGenFunction &CGF) {
1032       if (!SavedLocals.empty()) {
1033         copyInto(SavedLocals, CGF.LocalDeclMap);
1034         SavedLocals.clear();
1035       }
1036     }
1037 
1038   private:
1039     /// Copy all the entries in the source map over the corresponding
1040     /// entries in the destination, which must exist.
1041     static void copyInto(const DeclMapTy &Src, DeclMapTy &Dest) {
1042       for (auto &Pair : Src) {
1043         if (!Pair.second.isValid()) {
1044           Dest.erase(Pair.first);
1045           continue;
1046         }
1047 
1048         auto I = Dest.find(Pair.first);
1049         if (I != Dest.end())
1050           I->second = Pair.second;
1051         else
1052           Dest.insert(Pair);
1053       }
1054     }
1055   };
1056 
1057   /// The scope used to remap some variables as private in the OpenMP loop body
1058   /// (or other captured region emitted without outlining), and to restore old
1059   /// vars back on exit.
1060   class OMPPrivateScope : public RunCleanupsScope {
1061     OMPMapVars MappedVars;
1062     OMPPrivateScope(const OMPPrivateScope &) = delete;
1063     void operator=(const OMPPrivateScope &) = delete;
1064 
1065   public:
1066     /// Enter a new OpenMP private scope.
1067     explicit OMPPrivateScope(CodeGenFunction &CGF) : RunCleanupsScope(CGF) {}
1068 
1069     /// Registers \p LocalVD variable as a private and apply \p PrivateGen
1070     /// function for it to generate corresponding private variable. \p
1071     /// PrivateGen returns an address of the generated private variable.
1072     /// \return true if the variable is registered as private, false if it has
1073     /// been privatized already.
1074     bool addPrivate(const VarDecl *LocalVD,
1075                     const llvm::function_ref<Address()> PrivateGen) {
1076       assert(PerformCleanup && "adding private to dead scope");
1077       return MappedVars.setVarAddr(CGF, LocalVD, PrivateGen());
1078     }
1079 
1080     /// Privatizes local variables previously registered as private.
1081     /// Registration is separate from the actual privatization to allow
1082     /// initializers use values of the original variables, not the private one.
1083     /// This is important, for example, if the private variable is a class
1084     /// variable initialized by a constructor that references other private
1085     /// variables. But at initialization original variables must be used, not
1086     /// private copies.
1087     /// \return true if at least one variable was privatized, false otherwise.
1088     bool Privatize() { return MappedVars.apply(CGF); }
1089 
1090     void ForceCleanup() {
1091       RunCleanupsScope::ForceCleanup();
1092       MappedVars.restore(CGF);
1093     }
1094 
1095     /// Exit scope - all the mapped variables are restored.
1096     ~OMPPrivateScope() {
1097       if (PerformCleanup)
1098         ForceCleanup();
1099     }
1100 
1101     /// Checks if the global variable is captured in current function.
1102     bool isGlobalVarCaptured(const VarDecl *VD) const {
1103       VD = VD->getCanonicalDecl();
1104       return !VD->isLocalVarDeclOrParm() && CGF.LocalDeclMap.count(VD) > 0;
1105     }
1106   };
1107 
1108   /// Save/restore original map of previously emitted local vars in case when we
1109   /// need to duplicate emission of the same code several times in the same
1110   /// function for OpenMP code.
1111   class OMPLocalDeclMapRAII {
1112     CodeGenFunction &CGF;
1113     DeclMapTy SavedMap;
1114 
1115   public:
1116     OMPLocalDeclMapRAII(CodeGenFunction &CGF)
1117         : CGF(CGF), SavedMap(CGF.LocalDeclMap) {}
1118     ~OMPLocalDeclMapRAII() { SavedMap.swap(CGF.LocalDeclMap); }
1119   };
1120 
1121   /// Takes the old cleanup stack size and emits the cleanup blocks
1122   /// that have been added.
1123   void
1124   PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize,
1125                    std::initializer_list<llvm::Value **> ValuesToReload = {});
1126 
1127   /// Takes the old cleanup stack size and emits the cleanup blocks
1128   /// that have been added, then adds all lifetime-extended cleanups from
1129   /// the given position to the stack.
1130   void
1131   PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize,
1132                    size_t OldLifetimeExtendedStackSize,
1133                    std::initializer_list<llvm::Value **> ValuesToReload = {});
1134 
1135   void ResolveBranchFixups(llvm::BasicBlock *Target);
1136 
1137   /// The given basic block lies in the current EH scope, but may be a
1138   /// target of a potentially scope-crossing jump; get a stable handle
1139   /// to which we can perform this jump later.
1140   JumpDest getJumpDestInCurrentScope(llvm::BasicBlock *Target) {
1141     return JumpDest(Target,
1142                     EHStack.getInnermostNormalCleanup(),
1143                     NextCleanupDestIndex++);
1144   }
1145 
1146   /// The given basic block lies in the current EH scope, but may be a
1147   /// target of a potentially scope-crossing jump; get a stable handle
1148   /// to which we can perform this jump later.
1149   JumpDest getJumpDestInCurrentScope(StringRef Name = StringRef()) {
1150     return getJumpDestInCurrentScope(createBasicBlock(Name));
1151   }
1152 
1153   /// EmitBranchThroughCleanup - Emit a branch from the current insert
1154   /// block through the normal cleanup handling code (if any) and then
1155   /// on to \arg Dest.
1156   void EmitBranchThroughCleanup(JumpDest Dest);
1157 
1158   /// isObviouslyBranchWithoutCleanups - Return true if a branch to the
1159   /// specified destination obviously has no cleanups to run.  'false' is always
1160   /// a conservatively correct answer for this method.
1161   bool isObviouslyBranchWithoutCleanups(JumpDest Dest) const;
1162 
1163   /// popCatchScope - Pops the catch scope at the top of the EHScope
1164   /// stack, emitting any required code (other than the catch handlers
1165   /// themselves).
1166   void popCatchScope();
1167 
1168   llvm::BasicBlock *getEHResumeBlock(bool isCleanup);
1169   llvm::BasicBlock *getEHDispatchBlock(EHScopeStack::stable_iterator scope);
1170   llvm::BasicBlock *
1171   getFuncletEHDispatchBlock(EHScopeStack::stable_iterator scope);
1172 
1173   /// An object to manage conditionally-evaluated expressions.
1174   class ConditionalEvaluation {
1175     llvm::BasicBlock *StartBB;
1176 
1177   public:
1178     ConditionalEvaluation(CodeGenFunction &CGF)
1179       : StartBB(CGF.Builder.GetInsertBlock()) {}
1180 
1181     void begin(CodeGenFunction &CGF) {
1182       assert(CGF.OutermostConditional != this);
1183       if (!CGF.OutermostConditional)
1184         CGF.OutermostConditional = this;
1185     }
1186 
1187     void end(CodeGenFunction &CGF) {
1188       assert(CGF.OutermostConditional != nullptr);
1189       if (CGF.OutermostConditional == this)
1190         CGF.OutermostConditional = nullptr;
1191     }
1192 
1193     /// Returns a block which will be executed prior to each
1194     /// evaluation of the conditional code.
1195     llvm::BasicBlock *getStartingBlock() const {
1196       return StartBB;
1197     }
1198   };
1199 
1200   /// isInConditionalBranch - Return true if we're currently emitting
1201   /// one branch or the other of a conditional expression.
1202   bool isInConditionalBranch() const { return OutermostConditional != nullptr; }
1203 
1204   void setBeforeOutermostConditional(llvm::Value *value, Address addr) {
1205     assert(isInConditionalBranch());
1206     llvm::BasicBlock *block = OutermostConditional->getStartingBlock();
1207     auto store = new llvm::StoreInst(value, addr.getPointer(), &block->back());
1208     store->setAlignment(addr.getAlignment().getAsAlign());
1209   }
1210 
1211   /// An RAII object to record that we're evaluating a statement
1212   /// expression.
1213   class StmtExprEvaluation {
1214     CodeGenFunction &CGF;
1215 
1216     /// We have to save the outermost conditional: cleanups in a
1217     /// statement expression aren't conditional just because the
1218     /// StmtExpr is.
1219     ConditionalEvaluation *SavedOutermostConditional;
1220 
1221   public:
1222     StmtExprEvaluation(CodeGenFunction &CGF)
1223       : CGF(CGF), SavedOutermostConditional(CGF.OutermostConditional) {
1224       CGF.OutermostConditional = nullptr;
1225     }
1226 
1227     ~StmtExprEvaluation() {
1228       CGF.OutermostConditional = SavedOutermostConditional;
1229       CGF.EnsureInsertPoint();
1230     }
1231   };
1232 
1233   /// An object which temporarily prevents a value from being
1234   /// destroyed by aggressive peephole optimizations that assume that
1235   /// all uses of a value have been realized in the IR.
1236   class PeepholeProtection {
1237     llvm::Instruction *Inst;
1238     friend class CodeGenFunction;
1239 
1240   public:
1241     PeepholeProtection() : Inst(nullptr) {}
1242   };
1243 
1244   /// A non-RAII class containing all the information about a bound
1245   /// opaque value.  OpaqueValueMapping, below, is a RAII wrapper for
1246   /// this which makes individual mappings very simple; using this
1247   /// class directly is useful when you have a variable number of
1248   /// opaque values or don't want the RAII functionality for some
1249   /// reason.
1250   class OpaqueValueMappingData {
1251     const OpaqueValueExpr *OpaqueValue;
1252     bool BoundLValue;
1253     CodeGenFunction::PeepholeProtection Protection;
1254 
1255     OpaqueValueMappingData(const OpaqueValueExpr *ov,
1256                            bool boundLValue)
1257       : OpaqueValue(ov), BoundLValue(boundLValue) {}
1258   public:
1259     OpaqueValueMappingData() : OpaqueValue(nullptr) {}
1260 
1261     static bool shouldBindAsLValue(const Expr *expr) {
1262       // gl-values should be bound as l-values for obvious reasons.
1263       // Records should be bound as l-values because IR generation
1264       // always keeps them in memory.  Expressions of function type
1265       // act exactly like l-values but are formally required to be
1266       // r-values in C.
1267       return expr->isGLValue() ||
1268              expr->getType()->isFunctionType() ||
1269              hasAggregateEvaluationKind(expr->getType());
1270     }
1271 
1272     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
1273                                        const OpaqueValueExpr *ov,
1274                                        const Expr *e) {
1275       if (shouldBindAsLValue(ov))
1276         return bind(CGF, ov, CGF.EmitLValue(e));
1277       return bind(CGF, ov, CGF.EmitAnyExpr(e));
1278     }
1279 
1280     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
1281                                        const OpaqueValueExpr *ov,
1282                                        const LValue &lv) {
1283       assert(shouldBindAsLValue(ov));
1284       CGF.OpaqueLValues.insert(std::make_pair(ov, lv));
1285       return OpaqueValueMappingData(ov, true);
1286     }
1287 
1288     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
1289                                        const OpaqueValueExpr *ov,
1290                                        const RValue &rv) {
1291       assert(!shouldBindAsLValue(ov));
1292       CGF.OpaqueRValues.insert(std::make_pair(ov, rv));
1293 
1294       OpaqueValueMappingData data(ov, false);
1295 
1296       // Work around an extremely aggressive peephole optimization in
1297       // EmitScalarConversion which assumes that all other uses of a
1298       // value are extant.
1299       data.Protection = CGF.protectFromPeepholes(rv);
1300 
1301       return data;
1302     }
1303 
1304     bool isValid() const { return OpaqueValue != nullptr; }
1305     void clear() { OpaqueValue = nullptr; }
1306 
1307     void unbind(CodeGenFunction &CGF) {
1308       assert(OpaqueValue && "no data to unbind!");
1309 
1310       if (BoundLValue) {
1311         CGF.OpaqueLValues.erase(OpaqueValue);
1312       } else {
1313         CGF.OpaqueRValues.erase(OpaqueValue);
1314         CGF.unprotectFromPeepholes(Protection);
1315       }
1316     }
1317   };
1318 
1319   /// An RAII object to set (and then clear) a mapping for an OpaqueValueExpr.
1320   class OpaqueValueMapping {
1321     CodeGenFunction &CGF;
1322     OpaqueValueMappingData Data;
1323 
1324   public:
1325     static bool shouldBindAsLValue(const Expr *expr) {
1326       return OpaqueValueMappingData::shouldBindAsLValue(expr);
1327     }
1328 
1329     /// Build the opaque value mapping for the given conditional
1330     /// operator if it's the GNU ?: extension.  This is a common
1331     /// enough pattern that the convenience operator is really
1332     /// helpful.
1333     ///
1334     OpaqueValueMapping(CodeGenFunction &CGF,
1335                        const AbstractConditionalOperator *op) : CGF(CGF) {
1336       if (isa<ConditionalOperator>(op))
1337         // Leave Data empty.
1338         return;
1339 
1340       const BinaryConditionalOperator *e = cast<BinaryConditionalOperator>(op);
1341       Data = OpaqueValueMappingData::bind(CGF, e->getOpaqueValue(),
1342                                           e->getCommon());
1343     }
1344 
1345     /// Build the opaque value mapping for an OpaqueValueExpr whose source
1346     /// expression is set to the expression the OVE represents.
1347     OpaqueValueMapping(CodeGenFunction &CGF, const OpaqueValueExpr *OV)
1348         : CGF(CGF) {
1349       if (OV) {
1350         assert(OV->getSourceExpr() && "wrong form of OpaqueValueMapping used "
1351                                       "for OVE with no source expression");
1352         Data = OpaqueValueMappingData::bind(CGF, OV, OV->getSourceExpr());
1353       }
1354     }
1355 
1356     OpaqueValueMapping(CodeGenFunction &CGF,
1357                        const OpaqueValueExpr *opaqueValue,
1358                        LValue lvalue)
1359       : CGF(CGF), Data(OpaqueValueMappingData::bind(CGF, opaqueValue, lvalue)) {
1360     }
1361 
1362     OpaqueValueMapping(CodeGenFunction &CGF,
1363                        const OpaqueValueExpr *opaqueValue,
1364                        RValue rvalue)
1365       : CGF(CGF), Data(OpaqueValueMappingData::bind(CGF, opaqueValue, rvalue)) {
1366     }
1367 
1368     void pop() {
1369       Data.unbind(CGF);
1370       Data.clear();
1371     }
1372 
1373     ~OpaqueValueMapping() {
1374       if (Data.isValid()) Data.unbind(CGF);
1375     }
1376   };
1377 
1378 private:
1379   CGDebugInfo *DebugInfo;
1380   /// Used to create unique names for artificial VLA size debug info variables.
1381   unsigned VLAExprCounter = 0;
1382   bool DisableDebugInfo = false;
1383 
1384   /// DidCallStackSave - Whether llvm.stacksave has been called. Used to avoid
1385   /// calling llvm.stacksave for multiple VLAs in the same scope.
1386   bool DidCallStackSave = false;
1387 
1388   /// IndirectBranch - The first time an indirect goto is seen we create a block
1389   /// with an indirect branch.  Every time we see the address of a label taken,
1390   /// we add the label to the indirect goto.  Every subsequent indirect goto is
1391   /// codegen'd as a jump to the IndirectBranch's basic block.
1392   llvm::IndirectBrInst *IndirectBranch = nullptr;
1393 
1394   /// LocalDeclMap - This keeps track of the LLVM allocas or globals for local C
1395   /// decls.
1396   DeclMapTy LocalDeclMap;
1397 
1398   // Keep track of the cleanups for callee-destructed parameters pushed to the
1399   // cleanup stack so that they can be deactivated later.
1400   llvm::DenseMap<const ParmVarDecl *, EHScopeStack::stable_iterator>
1401       CalleeDestructedParamCleanups;
1402 
1403   /// SizeArguments - If a ParmVarDecl had the pass_object_size attribute, this
1404   /// will contain a mapping from said ParmVarDecl to its implicit "object_size"
1405   /// parameter.
1406   llvm::SmallDenseMap<const ParmVarDecl *, const ImplicitParamDecl *, 2>
1407       SizeArguments;
1408 
1409   /// Track escaped local variables with auto storage. Used during SEH
1410   /// outlining to produce a call to llvm.localescape.
1411   llvm::DenseMap<llvm::AllocaInst *, int> EscapedLocals;
1412 
1413   /// LabelMap - This keeps track of the LLVM basic block for each C label.
1414   llvm::DenseMap<const LabelDecl*, JumpDest> LabelMap;
1415 
1416   // BreakContinueStack - This keeps track of where break and continue
1417   // statements should jump to.
1418   struct BreakContinue {
1419     BreakContinue(JumpDest Break, JumpDest Continue)
1420       : BreakBlock(Break), ContinueBlock(Continue) {}
1421 
1422     JumpDest BreakBlock;
1423     JumpDest ContinueBlock;
1424   };
1425   SmallVector<BreakContinue, 8> BreakContinueStack;
1426 
1427   /// Handles cancellation exit points in OpenMP-related constructs.
1428   class OpenMPCancelExitStack {
1429     /// Tracks cancellation exit point and join point for cancel-related exit
1430     /// and normal exit.
1431     struct CancelExit {
1432       CancelExit() = default;
1433       CancelExit(OpenMPDirectiveKind Kind, JumpDest ExitBlock,
1434                  JumpDest ContBlock)
1435           : Kind(Kind), ExitBlock(ExitBlock), ContBlock(ContBlock) {}
1436       OpenMPDirectiveKind Kind = llvm::omp::OMPD_unknown;
1437       /// true if the exit block has been emitted already by the special
1438       /// emitExit() call, false if the default codegen is used.
1439       bool HasBeenEmitted = false;
1440       JumpDest ExitBlock;
1441       JumpDest ContBlock;
1442     };
1443 
1444     SmallVector<CancelExit, 8> Stack;
1445 
1446   public:
1447     OpenMPCancelExitStack() : Stack(1) {}
1448     ~OpenMPCancelExitStack() = default;
1449     /// Fetches the exit block for the current OpenMP construct.
1450     JumpDest getExitBlock() const { return Stack.back().ExitBlock; }
1451     /// Emits exit block with special codegen procedure specific for the related
1452     /// OpenMP construct + emits code for normal construct cleanup.
1453     void emitExit(CodeGenFunction &CGF, OpenMPDirectiveKind Kind,
1454                   const llvm::function_ref<void(CodeGenFunction &)> CodeGen) {
1455       if (Stack.back().Kind == Kind && getExitBlock().isValid()) {
1456         assert(CGF.getOMPCancelDestination(Kind).isValid());
1457         assert(CGF.HaveInsertPoint());
1458         assert(!Stack.back().HasBeenEmitted);
1459         auto IP = CGF.Builder.saveAndClearIP();
1460         CGF.EmitBlock(Stack.back().ExitBlock.getBlock());
1461         CodeGen(CGF);
1462         CGF.EmitBranch(Stack.back().ContBlock.getBlock());
1463         CGF.Builder.restoreIP(IP);
1464         Stack.back().HasBeenEmitted = true;
1465       }
1466       CodeGen(CGF);
1467     }
1468     /// Enter the cancel supporting \a Kind construct.
1469     /// \param Kind OpenMP directive that supports cancel constructs.
1470     /// \param HasCancel true, if the construct has inner cancel directive,
1471     /// false otherwise.
1472     void enter(CodeGenFunction &CGF, OpenMPDirectiveKind Kind, bool HasCancel) {
1473       Stack.push_back({Kind,
1474                        HasCancel ? CGF.getJumpDestInCurrentScope("cancel.exit")
1475                                  : JumpDest(),
1476                        HasCancel ? CGF.getJumpDestInCurrentScope("cancel.cont")
1477                                  : JumpDest()});
1478     }
1479     /// Emits default exit point for the cancel construct (if the special one
1480     /// has not be used) + join point for cancel/normal exits.
1481     void exit(CodeGenFunction &CGF) {
1482       if (getExitBlock().isValid()) {
1483         assert(CGF.getOMPCancelDestination(Stack.back().Kind).isValid());
1484         bool HaveIP = CGF.HaveInsertPoint();
1485         if (!Stack.back().HasBeenEmitted) {
1486           if (HaveIP)
1487             CGF.EmitBranchThroughCleanup(Stack.back().ContBlock);
1488           CGF.EmitBlock(Stack.back().ExitBlock.getBlock());
1489           CGF.EmitBranchThroughCleanup(Stack.back().ContBlock);
1490         }
1491         CGF.EmitBlock(Stack.back().ContBlock.getBlock());
1492         if (!HaveIP) {
1493           CGF.Builder.CreateUnreachable();
1494           CGF.Builder.ClearInsertionPoint();
1495         }
1496       }
1497       Stack.pop_back();
1498     }
1499   };
1500   OpenMPCancelExitStack OMPCancelStack;
1501 
1502   /// Lower the Likelihood knowledge about the \p Cond via llvm.expect intrin.
1503   llvm::Value *emitCondLikelihoodViaExpectIntrinsic(llvm::Value *Cond,
1504                                                     Stmt::Likelihood LH);
1505 
1506   CodeGenPGO PGO;
1507 
1508   /// Calculate branch weights appropriate for PGO data
1509   llvm::MDNode *createProfileWeights(uint64_t TrueCount,
1510                                      uint64_t FalseCount) const;
1511   llvm::MDNode *createProfileWeights(ArrayRef<uint64_t> Weights) const;
1512   llvm::MDNode *createProfileWeightsForLoop(const Stmt *Cond,
1513                                             uint64_t LoopCount) const;
1514 
1515 public:
1516   /// Increment the profiler's counter for the given statement by \p StepV.
1517   /// If \p StepV is null, the default increment is 1.
1518   void incrementProfileCounter(const Stmt *S, llvm::Value *StepV = nullptr) {
1519     if (CGM.getCodeGenOpts().hasProfileClangInstr() &&
1520         !CurFn->hasFnAttribute(llvm::Attribute::NoProfile))
1521       PGO.emitCounterIncrement(Builder, S, StepV);
1522     PGO.setCurrentStmt(S);
1523   }
1524 
1525   /// Get the profiler's count for the given statement.
1526   uint64_t getProfileCount(const Stmt *S) {
1527     Optional<uint64_t> Count = PGO.getStmtCount(S);
1528     if (!Count.hasValue())
1529       return 0;
1530     return *Count;
1531   }
1532 
1533   /// Set the profiler's current count.
1534   void setCurrentProfileCount(uint64_t Count) {
1535     PGO.setCurrentRegionCount(Count);
1536   }
1537 
1538   /// Get the profiler's current count. This is generally the count for the most
1539   /// recently incremented counter.
1540   uint64_t getCurrentProfileCount() {
1541     return PGO.getCurrentRegionCount();
1542   }
1543 
1544 private:
1545 
1546   /// SwitchInsn - This is nearest current switch instruction. It is null if
1547   /// current context is not in a switch.
1548   llvm::SwitchInst *SwitchInsn = nullptr;
1549   /// The branch weights of SwitchInsn when doing instrumentation based PGO.
1550   SmallVector<uint64_t, 16> *SwitchWeights = nullptr;
1551 
1552   /// The likelihood attributes of the SwitchCase.
1553   SmallVector<Stmt::Likelihood, 16> *SwitchLikelihood = nullptr;
1554 
1555   /// CaseRangeBlock - This block holds if condition check for last case
1556   /// statement range in current switch instruction.
1557   llvm::BasicBlock *CaseRangeBlock = nullptr;
1558 
1559   /// OpaqueLValues - Keeps track of the current set of opaque value
1560   /// expressions.
1561   llvm::DenseMap<const OpaqueValueExpr *, LValue> OpaqueLValues;
1562   llvm::DenseMap<const OpaqueValueExpr *, RValue> OpaqueRValues;
1563 
1564   // VLASizeMap - This keeps track of the associated size for each VLA type.
1565   // We track this by the size expression rather than the type itself because
1566   // in certain situations, like a const qualifier applied to an VLA typedef,
1567   // multiple VLA types can share the same size expression.
1568   // FIXME: Maybe this could be a stack of maps that is pushed/popped as we
1569   // enter/leave scopes.
1570   llvm::DenseMap<const Expr*, llvm::Value*> VLASizeMap;
1571 
1572   /// A block containing a single 'unreachable' instruction.  Created
1573   /// lazily by getUnreachableBlock().
1574   llvm::BasicBlock *UnreachableBlock = nullptr;
1575 
1576   /// Counts of the number return expressions in the function.
1577   unsigned NumReturnExprs = 0;
1578 
1579   /// Count the number of simple (constant) return expressions in the function.
1580   unsigned NumSimpleReturnExprs = 0;
1581 
1582   /// The last regular (non-return) debug location (breakpoint) in the function.
1583   SourceLocation LastStopPoint;
1584 
1585 public:
1586   /// Source location information about the default argument or member
1587   /// initializer expression we're evaluating, if any.
1588   CurrentSourceLocExprScope CurSourceLocExprScope;
1589   using SourceLocExprScopeGuard =
1590       CurrentSourceLocExprScope::SourceLocExprScopeGuard;
1591 
1592   /// A scope within which we are constructing the fields of an object which
1593   /// might use a CXXDefaultInitExpr. This stashes away a 'this' value to use
1594   /// if we need to evaluate a CXXDefaultInitExpr within the evaluation.
1595   class FieldConstructionScope {
1596   public:
1597     FieldConstructionScope(CodeGenFunction &CGF, Address This)
1598         : CGF(CGF), OldCXXDefaultInitExprThis(CGF.CXXDefaultInitExprThis) {
1599       CGF.CXXDefaultInitExprThis = This;
1600     }
1601     ~FieldConstructionScope() {
1602       CGF.CXXDefaultInitExprThis = OldCXXDefaultInitExprThis;
1603     }
1604 
1605   private:
1606     CodeGenFunction &CGF;
1607     Address OldCXXDefaultInitExprThis;
1608   };
1609 
1610   /// The scope of a CXXDefaultInitExpr. Within this scope, the value of 'this'
1611   /// is overridden to be the object under construction.
1612   class CXXDefaultInitExprScope  {
1613   public:
1614     CXXDefaultInitExprScope(CodeGenFunction &CGF, const CXXDefaultInitExpr *E)
1615         : CGF(CGF), OldCXXThisValue(CGF.CXXThisValue),
1616           OldCXXThisAlignment(CGF.CXXThisAlignment),
1617           SourceLocScope(E, CGF.CurSourceLocExprScope) {
1618       CGF.CXXThisValue = CGF.CXXDefaultInitExprThis.getPointer();
1619       CGF.CXXThisAlignment = CGF.CXXDefaultInitExprThis.getAlignment();
1620     }
1621     ~CXXDefaultInitExprScope() {
1622       CGF.CXXThisValue = OldCXXThisValue;
1623       CGF.CXXThisAlignment = OldCXXThisAlignment;
1624     }
1625 
1626   public:
1627     CodeGenFunction &CGF;
1628     llvm::Value *OldCXXThisValue;
1629     CharUnits OldCXXThisAlignment;
1630     SourceLocExprScopeGuard SourceLocScope;
1631   };
1632 
1633   struct CXXDefaultArgExprScope : SourceLocExprScopeGuard {
1634     CXXDefaultArgExprScope(CodeGenFunction &CGF, const CXXDefaultArgExpr *E)
1635         : SourceLocExprScopeGuard(E, CGF.CurSourceLocExprScope) {}
1636   };
1637 
1638   /// The scope of an ArrayInitLoopExpr. Within this scope, the value of the
1639   /// current loop index is overridden.
1640   class ArrayInitLoopExprScope {
1641   public:
1642     ArrayInitLoopExprScope(CodeGenFunction &CGF, llvm::Value *Index)
1643       : CGF(CGF), OldArrayInitIndex(CGF.ArrayInitIndex) {
1644       CGF.ArrayInitIndex = Index;
1645     }
1646     ~ArrayInitLoopExprScope() {
1647       CGF.ArrayInitIndex = OldArrayInitIndex;
1648     }
1649 
1650   private:
1651     CodeGenFunction &CGF;
1652     llvm::Value *OldArrayInitIndex;
1653   };
1654 
1655   class InlinedInheritingConstructorScope {
1656   public:
1657     InlinedInheritingConstructorScope(CodeGenFunction &CGF, GlobalDecl GD)
1658         : CGF(CGF), OldCurGD(CGF.CurGD), OldCurFuncDecl(CGF.CurFuncDecl),
1659           OldCurCodeDecl(CGF.CurCodeDecl),
1660           OldCXXABIThisDecl(CGF.CXXABIThisDecl),
1661           OldCXXABIThisValue(CGF.CXXABIThisValue),
1662           OldCXXThisValue(CGF.CXXThisValue),
1663           OldCXXABIThisAlignment(CGF.CXXABIThisAlignment),
1664           OldCXXThisAlignment(CGF.CXXThisAlignment),
1665           OldReturnValue(CGF.ReturnValue), OldFnRetTy(CGF.FnRetTy),
1666           OldCXXInheritedCtorInitExprArgs(
1667               std::move(CGF.CXXInheritedCtorInitExprArgs)) {
1668       CGF.CurGD = GD;
1669       CGF.CurFuncDecl = CGF.CurCodeDecl =
1670           cast<CXXConstructorDecl>(GD.getDecl());
1671       CGF.CXXABIThisDecl = nullptr;
1672       CGF.CXXABIThisValue = nullptr;
1673       CGF.CXXThisValue = nullptr;
1674       CGF.CXXABIThisAlignment = CharUnits();
1675       CGF.CXXThisAlignment = CharUnits();
1676       CGF.ReturnValue = Address::invalid();
1677       CGF.FnRetTy = QualType();
1678       CGF.CXXInheritedCtorInitExprArgs.clear();
1679     }
1680     ~InlinedInheritingConstructorScope() {
1681       CGF.CurGD = OldCurGD;
1682       CGF.CurFuncDecl = OldCurFuncDecl;
1683       CGF.CurCodeDecl = OldCurCodeDecl;
1684       CGF.CXXABIThisDecl = OldCXXABIThisDecl;
1685       CGF.CXXABIThisValue = OldCXXABIThisValue;
1686       CGF.CXXThisValue = OldCXXThisValue;
1687       CGF.CXXABIThisAlignment = OldCXXABIThisAlignment;
1688       CGF.CXXThisAlignment = OldCXXThisAlignment;
1689       CGF.ReturnValue = OldReturnValue;
1690       CGF.FnRetTy = OldFnRetTy;
1691       CGF.CXXInheritedCtorInitExprArgs =
1692           std::move(OldCXXInheritedCtorInitExprArgs);
1693     }
1694 
1695   private:
1696     CodeGenFunction &CGF;
1697     GlobalDecl OldCurGD;
1698     const Decl *OldCurFuncDecl;
1699     const Decl *OldCurCodeDecl;
1700     ImplicitParamDecl *OldCXXABIThisDecl;
1701     llvm::Value *OldCXXABIThisValue;
1702     llvm::Value *OldCXXThisValue;
1703     CharUnits OldCXXABIThisAlignment;
1704     CharUnits OldCXXThisAlignment;
1705     Address OldReturnValue;
1706     QualType OldFnRetTy;
1707     CallArgList OldCXXInheritedCtorInitExprArgs;
1708   };
1709 
1710   // Helper class for the OpenMP IR Builder. Allows reusability of code used for
1711   // region body, and finalization codegen callbacks. This will class will also
1712   // contain privatization functions used by the privatization call backs
1713   //
1714   // TODO: this is temporary class for things that are being moved out of
1715   // CGOpenMPRuntime, new versions of current CodeGenFunction methods, or
1716   // utility function for use with the OMPBuilder. Once that move to use the
1717   // OMPBuilder is done, everything here will either become part of CodeGenFunc.
1718   // directly, or a new helper class that will contain functions used by both
1719   // this and the OMPBuilder
1720 
1721   struct OMPBuilderCBHelpers {
1722 
1723     OMPBuilderCBHelpers() = delete;
1724     OMPBuilderCBHelpers(const OMPBuilderCBHelpers &) = delete;
1725     OMPBuilderCBHelpers &operator=(const OMPBuilderCBHelpers &) = delete;
1726 
1727     using InsertPointTy = llvm::OpenMPIRBuilder::InsertPointTy;
1728 
1729     /// Cleanup action for allocate support.
1730     class OMPAllocateCleanupTy final : public EHScopeStack::Cleanup {
1731 
1732     private:
1733       llvm::CallInst *RTLFnCI;
1734 
1735     public:
1736       OMPAllocateCleanupTy(llvm::CallInst *RLFnCI) : RTLFnCI(RLFnCI) {
1737         RLFnCI->removeFromParent();
1738       }
1739 
1740       void Emit(CodeGenFunction &CGF, Flags /*flags*/) override {
1741         if (!CGF.HaveInsertPoint())
1742           return;
1743         CGF.Builder.Insert(RTLFnCI);
1744       }
1745     };
1746 
1747     /// Returns address of the threadprivate variable for the current
1748     /// thread. This Also create any necessary OMP runtime calls.
1749     ///
1750     /// \param VD VarDecl for Threadprivate variable.
1751     /// \param VDAddr Address of the Vardecl
1752     /// \param Loc  The location where the barrier directive was encountered
1753     static Address getAddrOfThreadPrivate(CodeGenFunction &CGF,
1754                                           const VarDecl *VD, Address VDAddr,
1755                                           SourceLocation Loc);
1756 
1757     /// Gets the OpenMP-specific address of the local variable /p VD.
1758     static Address getAddressOfLocalVariable(CodeGenFunction &CGF,
1759                                              const VarDecl *VD);
1760     /// Get the platform-specific name separator.
1761     /// \param Parts different parts of the final name that needs separation
1762     /// \param FirstSeparator First separator used between the initial two
1763     ///        parts of the name.
1764     /// \param Separator separator used between all of the rest consecutinve
1765     ///        parts of the name
1766     static std::string getNameWithSeparators(ArrayRef<StringRef> Parts,
1767                                              StringRef FirstSeparator = ".",
1768                                              StringRef Separator = ".");
1769     /// Emit the Finalization for an OMP region
1770     /// \param CGF	The Codegen function this belongs to
1771     /// \param IP	Insertion point for generating the finalization code.
1772     static void FinalizeOMPRegion(CodeGenFunction &CGF, InsertPointTy IP) {
1773       CGBuilderTy::InsertPointGuard IPG(CGF.Builder);
1774       assert(IP.getBlock()->end() != IP.getPoint() &&
1775              "OpenMP IR Builder should cause terminated block!");
1776 
1777       llvm::BasicBlock *IPBB = IP.getBlock();
1778       llvm::BasicBlock *DestBB = IPBB->getUniqueSuccessor();
1779       assert(DestBB && "Finalization block should have one successor!");
1780 
1781       // erase and replace with cleanup branch.
1782       IPBB->getTerminator()->eraseFromParent();
1783       CGF.Builder.SetInsertPoint(IPBB);
1784       CodeGenFunction::JumpDest Dest = CGF.getJumpDestInCurrentScope(DestBB);
1785       CGF.EmitBranchThroughCleanup(Dest);
1786     }
1787 
1788     /// Emit the body of an OMP region
1789     /// \param CGF	The Codegen function this belongs to
1790     /// \param RegionBodyStmt	The body statement for the OpenMP region being
1791     /// 			 generated
1792     /// \param CodeGenIP	Insertion point for generating the body code.
1793     /// \param FiniBB	The finalization basic block
1794     static void EmitOMPRegionBody(CodeGenFunction &CGF,
1795                                   const Stmt *RegionBodyStmt,
1796                                   InsertPointTy CodeGenIP,
1797                                   llvm::BasicBlock &FiniBB) {
1798       llvm::BasicBlock *CodeGenIPBB = CodeGenIP.getBlock();
1799       if (llvm::Instruction *CodeGenIPBBTI = CodeGenIPBB->getTerminator())
1800         CodeGenIPBBTI->eraseFromParent();
1801 
1802       CGF.Builder.SetInsertPoint(CodeGenIPBB);
1803 
1804       CGF.EmitStmt(RegionBodyStmt);
1805 
1806       if (CGF.Builder.saveIP().isSet())
1807         CGF.Builder.CreateBr(&FiniBB);
1808     }
1809 
1810     static void EmitCaptureStmt(CodeGenFunction &CGF, InsertPointTy CodeGenIP,
1811                                 llvm::BasicBlock &FiniBB, llvm::Function *Fn,
1812                                 ArrayRef<llvm::Value *> Args) {
1813       llvm::BasicBlock *CodeGenIPBB = CodeGenIP.getBlock();
1814       if (llvm::Instruction *CodeGenIPBBTI = CodeGenIPBB->getTerminator())
1815         CodeGenIPBBTI->eraseFromParent();
1816 
1817       CGF.Builder.SetInsertPoint(CodeGenIPBB);
1818 
1819       if (Fn->doesNotThrow())
1820         CGF.EmitNounwindRuntimeCall(Fn, Args);
1821       else
1822         CGF.EmitRuntimeCall(Fn, Args);
1823 
1824       if (CGF.Builder.saveIP().isSet())
1825         CGF.Builder.CreateBr(&FiniBB);
1826     }
1827 
1828     /// RAII for preserving necessary info during Outlined region body codegen.
1829     class OutlinedRegionBodyRAII {
1830 
1831       llvm::AssertingVH<llvm::Instruction> OldAllocaIP;
1832       CodeGenFunction::JumpDest OldReturnBlock;
1833       CGBuilderTy::InsertPoint IP;
1834       CodeGenFunction &CGF;
1835 
1836     public:
1837       OutlinedRegionBodyRAII(CodeGenFunction &cgf, InsertPointTy &AllocaIP,
1838                              llvm::BasicBlock &RetBB)
1839           : CGF(cgf) {
1840         assert(AllocaIP.isSet() &&
1841                "Must specify Insertion point for allocas of outlined function");
1842         OldAllocaIP = CGF.AllocaInsertPt;
1843         CGF.AllocaInsertPt = &*AllocaIP.getPoint();
1844         IP = CGF.Builder.saveIP();
1845 
1846         OldReturnBlock = CGF.ReturnBlock;
1847         CGF.ReturnBlock = CGF.getJumpDestInCurrentScope(&RetBB);
1848       }
1849 
1850       ~OutlinedRegionBodyRAII() {
1851         CGF.AllocaInsertPt = OldAllocaIP;
1852         CGF.ReturnBlock = OldReturnBlock;
1853         CGF.Builder.restoreIP(IP);
1854       }
1855     };
1856 
1857     /// RAII for preserving necessary info during inlined region body codegen.
1858     class InlinedRegionBodyRAII {
1859 
1860       llvm::AssertingVH<llvm::Instruction> OldAllocaIP;
1861       CodeGenFunction &CGF;
1862 
1863     public:
1864       InlinedRegionBodyRAII(CodeGenFunction &cgf, InsertPointTy &AllocaIP,
1865                             llvm::BasicBlock &FiniBB)
1866           : CGF(cgf) {
1867         // Alloca insertion block should be in the entry block of the containing
1868         // function so it expects an empty AllocaIP in which case will reuse the
1869         // old alloca insertion point, or a new AllocaIP in the same block as
1870         // the old one
1871         assert((!AllocaIP.isSet() ||
1872                 CGF.AllocaInsertPt->getParent() == AllocaIP.getBlock()) &&
1873                "Insertion point should be in the entry block of containing "
1874                "function!");
1875         OldAllocaIP = CGF.AllocaInsertPt;
1876         if (AllocaIP.isSet())
1877           CGF.AllocaInsertPt = &*AllocaIP.getPoint();
1878 
1879         // TODO: Remove the call, after making sure the counter is not used by
1880         //       the EHStack.
1881         // Since this is an inlined region, it should not modify the
1882         // ReturnBlock, and should reuse the one for the enclosing outlined
1883         // region. So, the JumpDest being return by the function is discarded
1884         (void)CGF.getJumpDestInCurrentScope(&FiniBB);
1885       }
1886 
1887       ~InlinedRegionBodyRAII() { CGF.AllocaInsertPt = OldAllocaIP; }
1888     };
1889   };
1890 
1891 private:
1892   /// CXXThisDecl - When generating code for a C++ member function,
1893   /// this will hold the implicit 'this' declaration.
1894   ImplicitParamDecl *CXXABIThisDecl = nullptr;
1895   llvm::Value *CXXABIThisValue = nullptr;
1896   llvm::Value *CXXThisValue = nullptr;
1897   CharUnits CXXABIThisAlignment;
1898   CharUnits CXXThisAlignment;
1899 
1900   /// The value of 'this' to use when evaluating CXXDefaultInitExprs within
1901   /// this expression.
1902   Address CXXDefaultInitExprThis = Address::invalid();
1903 
1904   /// The current array initialization index when evaluating an
1905   /// ArrayInitIndexExpr within an ArrayInitLoopExpr.
1906   llvm::Value *ArrayInitIndex = nullptr;
1907 
1908   /// The values of function arguments to use when evaluating
1909   /// CXXInheritedCtorInitExprs within this context.
1910   CallArgList CXXInheritedCtorInitExprArgs;
1911 
1912   /// CXXStructorImplicitParamDecl - When generating code for a constructor or
1913   /// destructor, this will hold the implicit argument (e.g. VTT).
1914   ImplicitParamDecl *CXXStructorImplicitParamDecl = nullptr;
1915   llvm::Value *CXXStructorImplicitParamValue = nullptr;
1916 
1917   /// OutermostConditional - Points to the outermost active
1918   /// conditional control.  This is used so that we know if a
1919   /// temporary should be destroyed conditionally.
1920   ConditionalEvaluation *OutermostConditional = nullptr;
1921 
1922   /// The current lexical scope.
1923   LexicalScope *CurLexicalScope = nullptr;
1924 
1925   /// The current source location that should be used for exception
1926   /// handling code.
1927   SourceLocation CurEHLocation;
1928 
1929   /// BlockByrefInfos - For each __block variable, contains
1930   /// information about the layout of the variable.
1931   llvm::DenseMap<const ValueDecl *, BlockByrefInfo> BlockByrefInfos;
1932 
1933   /// Used by -fsanitize=nullability-return to determine whether the return
1934   /// value can be checked.
1935   llvm::Value *RetValNullabilityPrecondition = nullptr;
1936 
1937   /// Check if -fsanitize=nullability-return instrumentation is required for
1938   /// this function.
1939   bool requiresReturnValueNullabilityCheck() const {
1940     return RetValNullabilityPrecondition;
1941   }
1942 
1943   /// Used to store precise source locations for return statements by the
1944   /// runtime return value checks.
1945   Address ReturnLocation = Address::invalid();
1946 
1947   /// Check if the return value of this function requires sanitization.
1948   bool requiresReturnValueCheck() const;
1949 
1950   llvm::BasicBlock *TerminateLandingPad = nullptr;
1951   llvm::BasicBlock *TerminateHandler = nullptr;
1952   llvm::SmallVector<llvm::BasicBlock *, 2> TrapBBs;
1953 
1954   /// Terminate funclets keyed by parent funclet pad.
1955   llvm::MapVector<llvm::Value *, llvm::BasicBlock *> TerminateFunclets;
1956 
1957   /// Largest vector width used in ths function. Will be used to create a
1958   /// function attribute.
1959   unsigned LargestVectorWidth = 0;
1960 
1961   /// True if we need emit the life-time markers. This is initially set in
1962   /// the constructor, but could be overwritten to true if this is a coroutine.
1963   bool ShouldEmitLifetimeMarkers;
1964 
1965   /// Add OpenCL kernel arg metadata and the kernel attribute metadata to
1966   /// the function metadata.
1967   void EmitOpenCLKernelMetadata(const FunctionDecl *FD,
1968                                 llvm::Function *Fn);
1969 
1970 public:
1971   CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext=false);
1972   ~CodeGenFunction();
1973 
1974   CodeGenTypes &getTypes() const { return CGM.getTypes(); }
1975   ASTContext &getContext() const { return CGM.getContext(); }
1976   CGDebugInfo *getDebugInfo() {
1977     if (DisableDebugInfo)
1978       return nullptr;
1979     return DebugInfo;
1980   }
1981   void disableDebugInfo() { DisableDebugInfo = true; }
1982   void enableDebugInfo() { DisableDebugInfo = false; }
1983 
1984   bool shouldUseFusedARCCalls() {
1985     return CGM.getCodeGenOpts().OptimizationLevel == 0;
1986   }
1987 
1988   const LangOptions &getLangOpts() const { return CGM.getLangOpts(); }
1989 
1990   /// Returns a pointer to the function's exception object and selector slot,
1991   /// which is assigned in every landing pad.
1992   Address getExceptionSlot();
1993   Address getEHSelectorSlot();
1994 
1995   /// Returns the contents of the function's exception object and selector
1996   /// slots.
1997   llvm::Value *getExceptionFromSlot();
1998   llvm::Value *getSelectorFromSlot();
1999 
2000   Address getNormalCleanupDestSlot();
2001 
2002   llvm::BasicBlock *getUnreachableBlock() {
2003     if (!UnreachableBlock) {
2004       UnreachableBlock = createBasicBlock("unreachable");
2005       new llvm::UnreachableInst(getLLVMContext(), UnreachableBlock);
2006     }
2007     return UnreachableBlock;
2008   }
2009 
2010   llvm::BasicBlock *getInvokeDest() {
2011     if (!EHStack.requiresLandingPad()) return nullptr;
2012     return getInvokeDestImpl();
2013   }
2014 
2015   bool currentFunctionUsesSEHTry() const { return CurSEHParent != nullptr; }
2016 
2017   const TargetInfo &getTarget() const { return Target; }
2018   llvm::LLVMContext &getLLVMContext() { return CGM.getLLVMContext(); }
2019   const TargetCodeGenInfo &getTargetHooks() const {
2020     return CGM.getTargetCodeGenInfo();
2021   }
2022 
2023   //===--------------------------------------------------------------------===//
2024   //                                  Cleanups
2025   //===--------------------------------------------------------------------===//
2026 
2027   typedef void Destroyer(CodeGenFunction &CGF, Address addr, QualType ty);
2028 
2029   void pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin,
2030                                         Address arrayEndPointer,
2031                                         QualType elementType,
2032                                         CharUnits elementAlignment,
2033                                         Destroyer *destroyer);
2034   void pushRegularPartialArrayCleanup(llvm::Value *arrayBegin,
2035                                       llvm::Value *arrayEnd,
2036                                       QualType elementType,
2037                                       CharUnits elementAlignment,
2038                                       Destroyer *destroyer);
2039 
2040   void pushDestroy(QualType::DestructionKind dtorKind,
2041                    Address addr, QualType type);
2042   void pushEHDestroy(QualType::DestructionKind dtorKind,
2043                      Address addr, QualType type);
2044   void pushDestroy(CleanupKind kind, Address addr, QualType type,
2045                    Destroyer *destroyer, bool useEHCleanupForArray);
2046   void pushLifetimeExtendedDestroy(CleanupKind kind, Address addr,
2047                                    QualType type, Destroyer *destroyer,
2048                                    bool useEHCleanupForArray);
2049   void pushCallObjectDeleteCleanup(const FunctionDecl *OperatorDelete,
2050                                    llvm::Value *CompletePtr,
2051                                    QualType ElementType);
2052   void pushStackRestore(CleanupKind kind, Address SPMem);
2053   void emitDestroy(Address addr, QualType type, Destroyer *destroyer,
2054                    bool useEHCleanupForArray);
2055   llvm::Function *generateDestroyHelper(Address addr, QualType type,
2056                                         Destroyer *destroyer,
2057                                         bool useEHCleanupForArray,
2058                                         const VarDecl *VD);
2059   void emitArrayDestroy(llvm::Value *begin, llvm::Value *end,
2060                         QualType elementType, CharUnits elementAlign,
2061                         Destroyer *destroyer,
2062                         bool checkZeroLength, bool useEHCleanup);
2063 
2064   Destroyer *getDestroyer(QualType::DestructionKind destructionKind);
2065 
2066   /// Determines whether an EH cleanup is required to destroy a type
2067   /// with the given destruction kind.
2068   bool needsEHCleanup(QualType::DestructionKind kind) {
2069     switch (kind) {
2070     case QualType::DK_none:
2071       return false;
2072     case QualType::DK_cxx_destructor:
2073     case QualType::DK_objc_weak_lifetime:
2074     case QualType::DK_nontrivial_c_struct:
2075       return getLangOpts().Exceptions;
2076     case QualType::DK_objc_strong_lifetime:
2077       return getLangOpts().Exceptions &&
2078              CGM.getCodeGenOpts().ObjCAutoRefCountExceptions;
2079     }
2080     llvm_unreachable("bad destruction kind");
2081   }
2082 
2083   CleanupKind getCleanupKind(QualType::DestructionKind kind) {
2084     return (needsEHCleanup(kind) ? NormalAndEHCleanup : NormalCleanup);
2085   }
2086 
2087   //===--------------------------------------------------------------------===//
2088   //                                  Objective-C
2089   //===--------------------------------------------------------------------===//
2090 
2091   void GenerateObjCMethod(const ObjCMethodDecl *OMD);
2092 
2093   void StartObjCMethod(const ObjCMethodDecl *MD, const ObjCContainerDecl *CD);
2094 
2095   /// GenerateObjCGetter - Synthesize an Objective-C property getter function.
2096   void GenerateObjCGetter(ObjCImplementationDecl *IMP,
2097                           const ObjCPropertyImplDecl *PID);
2098   void generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
2099                               const ObjCPropertyImplDecl *propImpl,
2100                               const ObjCMethodDecl *GetterMothodDecl,
2101                               llvm::Constant *AtomicHelperFn);
2102 
2103   void GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP,
2104                                   ObjCMethodDecl *MD, bool ctor);
2105 
2106   /// GenerateObjCSetter - Synthesize an Objective-C property setter function
2107   /// for the given property.
2108   void GenerateObjCSetter(ObjCImplementationDecl *IMP,
2109                           const ObjCPropertyImplDecl *PID);
2110   void generateObjCSetterBody(const ObjCImplementationDecl *classImpl,
2111                               const ObjCPropertyImplDecl *propImpl,
2112                               llvm::Constant *AtomicHelperFn);
2113 
2114   //===--------------------------------------------------------------------===//
2115   //                                  Block Bits
2116   //===--------------------------------------------------------------------===//
2117 
2118   /// Emit block literal.
2119   /// \return an LLVM value which is a pointer to a struct which contains
2120   /// information about the block, including the block invoke function, the
2121   /// captured variables, etc.
2122   llvm::Value *EmitBlockLiteral(const BlockExpr *);
2123 
2124   llvm::Function *GenerateBlockFunction(GlobalDecl GD,
2125                                         const CGBlockInfo &Info,
2126                                         const DeclMapTy &ldm,
2127                                         bool IsLambdaConversionToBlock,
2128                                         bool BuildGlobalBlock);
2129 
2130   /// Check if \p T is a C++ class that has a destructor that can throw.
2131   static bool cxxDestructorCanThrow(QualType T);
2132 
2133   llvm::Constant *GenerateCopyHelperFunction(const CGBlockInfo &blockInfo);
2134   llvm::Constant *GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo);
2135   llvm::Constant *GenerateObjCAtomicSetterCopyHelperFunction(
2136                                              const ObjCPropertyImplDecl *PID);
2137   llvm::Constant *GenerateObjCAtomicGetterCopyHelperFunction(
2138                                              const ObjCPropertyImplDecl *PID);
2139   llvm::Value *EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty);
2140 
2141   void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags,
2142                          bool CanThrow);
2143 
2144   class AutoVarEmission;
2145 
2146   void emitByrefStructureInit(const AutoVarEmission &emission);
2147 
2148   /// Enter a cleanup to destroy a __block variable.  Note that this
2149   /// cleanup should be a no-op if the variable hasn't left the stack
2150   /// yet; if a cleanup is required for the variable itself, that needs
2151   /// to be done externally.
2152   ///
2153   /// \param Kind Cleanup kind.
2154   ///
2155   /// \param Addr When \p LoadBlockVarAddr is false, the address of the __block
2156   /// structure that will be passed to _Block_object_dispose. When
2157   /// \p LoadBlockVarAddr is true, the address of the field of the block
2158   /// structure that holds the address of the __block structure.
2159   ///
2160   /// \param Flags The flag that will be passed to _Block_object_dispose.
2161   ///
2162   /// \param LoadBlockVarAddr Indicates whether we need to emit a load from
2163   /// \p Addr to get the address of the __block structure.
2164   void enterByrefCleanup(CleanupKind Kind, Address Addr, BlockFieldFlags Flags,
2165                          bool LoadBlockVarAddr, bool CanThrow);
2166 
2167   void setBlockContextParameter(const ImplicitParamDecl *D, unsigned argNum,
2168                                 llvm::Value *ptr);
2169 
2170   Address LoadBlockStruct();
2171   Address GetAddrOfBlockDecl(const VarDecl *var);
2172 
2173   /// BuildBlockByrefAddress - Computes the location of the
2174   /// data in a variable which is declared as __block.
2175   Address emitBlockByrefAddress(Address baseAddr, const VarDecl *V,
2176                                 bool followForward = true);
2177   Address emitBlockByrefAddress(Address baseAddr,
2178                                 const BlockByrefInfo &info,
2179                                 bool followForward,
2180                                 const llvm::Twine &name);
2181 
2182   const BlockByrefInfo &getBlockByrefInfo(const VarDecl *var);
2183 
2184   QualType BuildFunctionArgList(GlobalDecl GD, FunctionArgList &Args);
2185 
2186   void GenerateCode(GlobalDecl GD, llvm::Function *Fn,
2187                     const CGFunctionInfo &FnInfo);
2188 
2189   /// Annotate the function with an attribute that disables TSan checking at
2190   /// runtime.
2191   void markAsIgnoreThreadCheckingAtRuntime(llvm::Function *Fn);
2192 
2193   /// Emit code for the start of a function.
2194   /// \param Loc       The location to be associated with the function.
2195   /// \param StartLoc  The location of the function body.
2196   void StartFunction(GlobalDecl GD,
2197                      QualType RetTy,
2198                      llvm::Function *Fn,
2199                      const CGFunctionInfo &FnInfo,
2200                      const FunctionArgList &Args,
2201                      SourceLocation Loc = SourceLocation(),
2202                      SourceLocation StartLoc = SourceLocation());
2203 
2204   static bool IsConstructorDelegationValid(const CXXConstructorDecl *Ctor);
2205 
2206   void EmitConstructorBody(FunctionArgList &Args);
2207   void EmitDestructorBody(FunctionArgList &Args);
2208   void emitImplicitAssignmentOperatorBody(FunctionArgList &Args);
2209   void EmitFunctionBody(const Stmt *Body);
2210   void EmitBlockWithFallThrough(llvm::BasicBlock *BB, const Stmt *S);
2211 
2212   void EmitForwardingCallToLambda(const CXXMethodDecl *LambdaCallOperator,
2213                                   CallArgList &CallArgs);
2214   void EmitLambdaBlockInvokeBody();
2215   void EmitLambdaDelegatingInvokeBody(const CXXMethodDecl *MD);
2216   void EmitLambdaStaticInvokeBody(const CXXMethodDecl *MD);
2217   void EmitLambdaVLACapture(const VariableArrayType *VAT, LValue LV) {
2218     EmitStoreThroughLValue(RValue::get(VLASizeMap[VAT->getSizeExpr()]), LV);
2219   }
2220   void EmitAsanPrologueOrEpilogue(bool Prologue);
2221 
2222   /// Emit the unified return block, trying to avoid its emission when
2223   /// possible.
2224   /// \return The debug location of the user written return statement if the
2225   /// return block is is avoided.
2226   llvm::DebugLoc EmitReturnBlock();
2227 
2228   /// FinishFunction - Complete IR generation of the current function. It is
2229   /// legal to call this function even if there is no current insertion point.
2230   void FinishFunction(SourceLocation EndLoc=SourceLocation());
2231 
2232   void StartThunk(llvm::Function *Fn, GlobalDecl GD,
2233                   const CGFunctionInfo &FnInfo, bool IsUnprototyped);
2234 
2235   void EmitCallAndReturnForThunk(llvm::FunctionCallee Callee,
2236                                  const ThunkInfo *Thunk, bool IsUnprototyped);
2237 
2238   void FinishThunk();
2239 
2240   /// Emit a musttail call for a thunk with a potentially adjusted this pointer.
2241   void EmitMustTailThunk(GlobalDecl GD, llvm::Value *AdjustedThisPtr,
2242                          llvm::FunctionCallee Callee);
2243 
2244   /// Generate a thunk for the given method.
2245   void generateThunk(llvm::Function *Fn, const CGFunctionInfo &FnInfo,
2246                      GlobalDecl GD, const ThunkInfo &Thunk,
2247                      bool IsUnprototyped);
2248 
2249   llvm::Function *GenerateVarArgsThunk(llvm::Function *Fn,
2250                                        const CGFunctionInfo &FnInfo,
2251                                        GlobalDecl GD, const ThunkInfo &Thunk);
2252 
2253   void EmitCtorPrologue(const CXXConstructorDecl *CD, CXXCtorType Type,
2254                         FunctionArgList &Args);
2255 
2256   void EmitInitializerForField(FieldDecl *Field, LValue LHS, Expr *Init);
2257 
2258   /// Struct with all information about dynamic [sub]class needed to set vptr.
2259   struct VPtr {
2260     BaseSubobject Base;
2261     const CXXRecordDecl *NearestVBase;
2262     CharUnits OffsetFromNearestVBase;
2263     const CXXRecordDecl *VTableClass;
2264   };
2265 
2266   /// Initialize the vtable pointer of the given subobject.
2267   void InitializeVTablePointer(const VPtr &vptr);
2268 
2269   typedef llvm::SmallVector<VPtr, 4> VPtrsVector;
2270 
2271   typedef llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBasesSetTy;
2272   VPtrsVector getVTablePointers(const CXXRecordDecl *VTableClass);
2273 
2274   void getVTablePointers(BaseSubobject Base, const CXXRecordDecl *NearestVBase,
2275                          CharUnits OffsetFromNearestVBase,
2276                          bool BaseIsNonVirtualPrimaryBase,
2277                          const CXXRecordDecl *VTableClass,
2278                          VisitedVirtualBasesSetTy &VBases, VPtrsVector &vptrs);
2279 
2280   void InitializeVTablePointers(const CXXRecordDecl *ClassDecl);
2281 
2282   /// GetVTablePtr - Return the Value of the vtable pointer member pointed
2283   /// to by This.
2284   llvm::Value *GetVTablePtr(Address This, llvm::Type *VTableTy,
2285                             const CXXRecordDecl *VTableClass);
2286 
2287   enum CFITypeCheckKind {
2288     CFITCK_VCall,
2289     CFITCK_NVCall,
2290     CFITCK_DerivedCast,
2291     CFITCK_UnrelatedCast,
2292     CFITCK_ICall,
2293     CFITCK_NVMFCall,
2294     CFITCK_VMFCall,
2295   };
2296 
2297   /// Derived is the presumed address of an object of type T after a
2298   /// cast. If T is a polymorphic class type, emit a check that the virtual
2299   /// table for Derived belongs to a class derived from T.
2300   void EmitVTablePtrCheckForCast(QualType T, llvm::Value *Derived,
2301                                  bool MayBeNull, CFITypeCheckKind TCK,
2302                                  SourceLocation Loc);
2303 
2304   /// EmitVTablePtrCheckForCall - Virtual method MD is being called via VTable.
2305   /// If vptr CFI is enabled, emit a check that VTable is valid.
2306   void EmitVTablePtrCheckForCall(const CXXRecordDecl *RD, llvm::Value *VTable,
2307                                  CFITypeCheckKind TCK, SourceLocation Loc);
2308 
2309   /// EmitVTablePtrCheck - Emit a check that VTable is a valid virtual table for
2310   /// RD using llvm.type.test.
2311   void EmitVTablePtrCheck(const CXXRecordDecl *RD, llvm::Value *VTable,
2312                           CFITypeCheckKind TCK, SourceLocation Loc);
2313 
2314   /// If whole-program virtual table optimization is enabled, emit an assumption
2315   /// that VTable is a member of RD's type identifier. Or, if vptr CFI is
2316   /// enabled, emit a check that VTable is a member of RD's type identifier.
2317   void EmitTypeMetadataCodeForVCall(const CXXRecordDecl *RD,
2318                                     llvm::Value *VTable, SourceLocation Loc);
2319 
2320   /// Returns whether we should perform a type checked load when loading a
2321   /// virtual function for virtual calls to members of RD. This is generally
2322   /// true when both vcall CFI and whole-program-vtables are enabled.
2323   bool ShouldEmitVTableTypeCheckedLoad(const CXXRecordDecl *RD);
2324 
2325   /// Emit a type checked load from the given vtable.
2326   llvm::Value *EmitVTableTypeCheckedLoad(const CXXRecordDecl *RD, llvm::Value *VTable,
2327                                          uint64_t VTableByteOffset);
2328 
2329   /// EnterDtorCleanups - Enter the cleanups necessary to complete the
2330   /// given phase of destruction for a destructor.  The end result
2331   /// should call destructors on members and base classes in reverse
2332   /// order of their construction.
2333   void EnterDtorCleanups(const CXXDestructorDecl *Dtor, CXXDtorType Type);
2334 
2335   /// ShouldInstrumentFunction - Return true if the current function should be
2336   /// instrumented with __cyg_profile_func_* calls
2337   bool ShouldInstrumentFunction();
2338 
2339   /// ShouldSkipSanitizerInstrumentation - Return true if the current function
2340   /// should not be instrumented with sanitizers.
2341   bool ShouldSkipSanitizerInstrumentation();
2342 
2343   /// ShouldXRayInstrument - Return true if the current function should be
2344   /// instrumented with XRay nop sleds.
2345   bool ShouldXRayInstrumentFunction() const;
2346 
2347   /// AlwaysEmitXRayCustomEvents - Return true if we must unconditionally emit
2348   /// XRay custom event handling calls.
2349   bool AlwaysEmitXRayCustomEvents() const;
2350 
2351   /// AlwaysEmitXRayTypedEvents - Return true if clang must unconditionally emit
2352   /// XRay typed event handling calls.
2353   bool AlwaysEmitXRayTypedEvents() const;
2354 
2355   /// Encode an address into a form suitable for use in a function prologue.
2356   llvm::Constant *EncodeAddrForUseInPrologue(llvm::Function *F,
2357                                              llvm::Constant *Addr);
2358 
2359   /// Decode an address used in a function prologue, encoded by \c
2360   /// EncodeAddrForUseInPrologue.
2361   llvm::Value *DecodeAddrUsedInPrologue(llvm::Value *F,
2362                                         llvm::Value *EncodedAddr);
2363 
2364   /// EmitFunctionProlog - Emit the target specific LLVM code to load the
2365   /// arguments for the given function. This is also responsible for naming the
2366   /// LLVM function arguments.
2367   void EmitFunctionProlog(const CGFunctionInfo &FI,
2368                           llvm::Function *Fn,
2369                           const FunctionArgList &Args);
2370 
2371   /// EmitFunctionEpilog - Emit the target specific LLVM code to return the
2372   /// given temporary.
2373   void EmitFunctionEpilog(const CGFunctionInfo &FI, bool EmitRetDbgLoc,
2374                           SourceLocation EndLoc);
2375 
2376   /// Emit a test that checks if the return value \p RV is nonnull.
2377   void EmitReturnValueCheck(llvm::Value *RV);
2378 
2379   /// EmitStartEHSpec - Emit the start of the exception spec.
2380   void EmitStartEHSpec(const Decl *D);
2381 
2382   /// EmitEndEHSpec - Emit the end of the exception spec.
2383   void EmitEndEHSpec(const Decl *D);
2384 
2385   /// getTerminateLandingPad - Return a landing pad that just calls terminate.
2386   llvm::BasicBlock *getTerminateLandingPad();
2387 
2388   /// getTerminateLandingPad - Return a cleanup funclet that just calls
2389   /// terminate.
2390   llvm::BasicBlock *getTerminateFunclet();
2391 
2392   /// getTerminateHandler - Return a handler (not a landing pad, just
2393   /// a catch handler) that just calls terminate.  This is used when
2394   /// a terminate scope encloses a try.
2395   llvm::BasicBlock *getTerminateHandler();
2396 
2397   llvm::Type *ConvertTypeForMem(QualType T);
2398   llvm::Type *ConvertType(QualType T);
2399   llvm::Type *ConvertType(const TypeDecl *T) {
2400     return ConvertType(getContext().getTypeDeclType(T));
2401   }
2402 
2403   /// LoadObjCSelf - Load the value of self. This function is only valid while
2404   /// generating code for an Objective-C method.
2405   llvm::Value *LoadObjCSelf();
2406 
2407   /// TypeOfSelfObject - Return type of object that this self represents.
2408   QualType TypeOfSelfObject();
2409 
2410   /// getEvaluationKind - Return the TypeEvaluationKind of QualType \c T.
2411   static TypeEvaluationKind getEvaluationKind(QualType T);
2412 
2413   static bool hasScalarEvaluationKind(QualType T) {
2414     return getEvaluationKind(T) == TEK_Scalar;
2415   }
2416 
2417   static bool hasAggregateEvaluationKind(QualType T) {
2418     return getEvaluationKind(T) == TEK_Aggregate;
2419   }
2420 
2421   /// createBasicBlock - Create an LLVM basic block.
2422   llvm::BasicBlock *createBasicBlock(const Twine &name = "",
2423                                      llvm::Function *parent = nullptr,
2424                                      llvm::BasicBlock *before = nullptr) {
2425     return llvm::BasicBlock::Create(getLLVMContext(), name, parent, before);
2426   }
2427 
2428   /// getBasicBlockForLabel - Return the LLVM basicblock that the specified
2429   /// label maps to.
2430   JumpDest getJumpDestForLabel(const LabelDecl *S);
2431 
2432   /// SimplifyForwardingBlocks - If the given basic block is only a branch to
2433   /// another basic block, simplify it. This assumes that no other code could
2434   /// potentially reference the basic block.
2435   void SimplifyForwardingBlocks(llvm::BasicBlock *BB);
2436 
2437   /// EmitBlock - Emit the given block \arg BB and set it as the insert point,
2438   /// adding a fall-through branch from the current insert block if
2439   /// necessary. It is legal to call this function even if there is no current
2440   /// insertion point.
2441   ///
2442   /// IsFinished - If true, indicates that the caller has finished emitting
2443   /// branches to the given block and does not expect to emit code into it. This
2444   /// means the block can be ignored if it is unreachable.
2445   void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false);
2446 
2447   /// EmitBlockAfterUses - Emit the given block somewhere hopefully
2448   /// near its uses, and leave the insertion point in it.
2449   void EmitBlockAfterUses(llvm::BasicBlock *BB);
2450 
2451   /// EmitBranch - Emit a branch to the specified basic block from the current
2452   /// insert block, taking care to avoid creation of branches from dummy
2453   /// blocks. It is legal to call this function even if there is no current
2454   /// insertion point.
2455   ///
2456   /// This function clears the current insertion point. The caller should follow
2457   /// calls to this function with calls to Emit*Block prior to generation new
2458   /// code.
2459   void EmitBranch(llvm::BasicBlock *Block);
2460 
2461   /// HaveInsertPoint - True if an insertion point is defined. If not, this
2462   /// indicates that the current code being emitted is unreachable.
2463   bool HaveInsertPoint() const {
2464     return Builder.GetInsertBlock() != nullptr;
2465   }
2466 
2467   /// EnsureInsertPoint - Ensure that an insertion point is defined so that
2468   /// emitted IR has a place to go. Note that by definition, if this function
2469   /// creates a block then that block is unreachable; callers may do better to
2470   /// detect when no insertion point is defined and simply skip IR generation.
2471   void EnsureInsertPoint() {
2472     if (!HaveInsertPoint())
2473       EmitBlock(createBasicBlock());
2474   }
2475 
2476   /// ErrorUnsupported - Print out an error that codegen doesn't support the
2477   /// specified stmt yet.
2478   void ErrorUnsupported(const Stmt *S, const char *Type);
2479 
2480   //===--------------------------------------------------------------------===//
2481   //                                  Helpers
2482   //===--------------------------------------------------------------------===//
2483 
2484   LValue MakeAddrLValue(Address Addr, QualType T,
2485                         AlignmentSource Source = AlignmentSource::Type) {
2486     return LValue::MakeAddr(Addr, T, getContext(), LValueBaseInfo(Source),
2487                             CGM.getTBAAAccessInfo(T));
2488   }
2489 
2490   LValue MakeAddrLValue(Address Addr, QualType T, LValueBaseInfo BaseInfo,
2491                         TBAAAccessInfo TBAAInfo) {
2492     return LValue::MakeAddr(Addr, T, getContext(), BaseInfo, TBAAInfo);
2493   }
2494 
2495   LValue MakeAddrLValue(llvm::Value *V, QualType T, CharUnits Alignment,
2496                         AlignmentSource Source = AlignmentSource::Type) {
2497     return LValue::MakeAddr(Address(V, Alignment), T, getContext(),
2498                             LValueBaseInfo(Source), CGM.getTBAAAccessInfo(T));
2499   }
2500 
2501   LValue MakeAddrLValue(llvm::Value *V, QualType T, CharUnits Alignment,
2502                         LValueBaseInfo BaseInfo, TBAAAccessInfo TBAAInfo) {
2503     return LValue::MakeAddr(Address(V, Alignment), T, getContext(),
2504                             BaseInfo, TBAAInfo);
2505   }
2506 
2507   LValue MakeNaturalAlignPointeeAddrLValue(llvm::Value *V, QualType T);
2508   LValue MakeNaturalAlignAddrLValue(llvm::Value *V, QualType T);
2509 
2510   Address EmitLoadOfReference(LValue RefLVal,
2511                               LValueBaseInfo *PointeeBaseInfo = nullptr,
2512                               TBAAAccessInfo *PointeeTBAAInfo = nullptr);
2513   LValue EmitLoadOfReferenceLValue(LValue RefLVal);
2514   LValue EmitLoadOfReferenceLValue(Address RefAddr, QualType RefTy,
2515                                    AlignmentSource Source =
2516                                        AlignmentSource::Type) {
2517     LValue RefLVal = MakeAddrLValue(RefAddr, RefTy, LValueBaseInfo(Source),
2518                                     CGM.getTBAAAccessInfo(RefTy));
2519     return EmitLoadOfReferenceLValue(RefLVal);
2520   }
2521 
2522   Address EmitLoadOfPointer(Address Ptr, const PointerType *PtrTy,
2523                             LValueBaseInfo *BaseInfo = nullptr,
2524                             TBAAAccessInfo *TBAAInfo = nullptr);
2525   LValue EmitLoadOfPointerLValue(Address Ptr, const PointerType *PtrTy);
2526 
2527   /// CreateTempAlloca - This creates an alloca and inserts it into the entry
2528   /// block if \p ArraySize is nullptr, otherwise inserts it at the current
2529   /// insertion point of the builder. The caller is responsible for setting an
2530   /// appropriate alignment on
2531   /// the alloca.
2532   ///
2533   /// \p ArraySize is the number of array elements to be allocated if it
2534   ///    is not nullptr.
2535   ///
2536   /// LangAS::Default is the address space of pointers to local variables and
2537   /// temporaries, as exposed in the source language. In certain
2538   /// configurations, this is not the same as the alloca address space, and a
2539   /// cast is needed to lift the pointer from the alloca AS into
2540   /// LangAS::Default. This can happen when the target uses a restricted
2541   /// address space for the stack but the source language requires
2542   /// LangAS::Default to be a generic address space. The latter condition is
2543   /// common for most programming languages; OpenCL is an exception in that
2544   /// LangAS::Default is the private address space, which naturally maps
2545   /// to the stack.
2546   ///
2547   /// Because the address of a temporary is often exposed to the program in
2548   /// various ways, this function will perform the cast. The original alloca
2549   /// instruction is returned through \p Alloca if it is not nullptr.
2550   ///
2551   /// The cast is not performaed in CreateTempAllocaWithoutCast. This is
2552   /// more efficient if the caller knows that the address will not be exposed.
2553   llvm::AllocaInst *CreateTempAlloca(llvm::Type *Ty, const Twine &Name = "tmp",
2554                                      llvm::Value *ArraySize = nullptr);
2555   Address CreateTempAlloca(llvm::Type *Ty, CharUnits align,
2556                            const Twine &Name = "tmp",
2557                            llvm::Value *ArraySize = nullptr,
2558                            Address *Alloca = nullptr);
2559   Address CreateTempAllocaWithoutCast(llvm::Type *Ty, CharUnits align,
2560                                       const Twine &Name = "tmp",
2561                                       llvm::Value *ArraySize = nullptr);
2562 
2563   /// CreateDefaultAlignedTempAlloca - This creates an alloca with the
2564   /// default ABI alignment of the given LLVM type.
2565   ///
2566   /// IMPORTANT NOTE: This is *not* generally the right alignment for
2567   /// any given AST type that happens to have been lowered to the
2568   /// given IR type.  This should only ever be used for function-local,
2569   /// IR-driven manipulations like saving and restoring a value.  Do
2570   /// not hand this address off to arbitrary IRGen routines, and especially
2571   /// do not pass it as an argument to a function that might expect a
2572   /// properly ABI-aligned value.
2573   Address CreateDefaultAlignTempAlloca(llvm::Type *Ty,
2574                                        const Twine &Name = "tmp");
2575 
2576   /// CreateIRTemp - Create a temporary IR object of the given type, with
2577   /// appropriate alignment. This routine should only be used when an temporary
2578   /// value needs to be stored into an alloca (for example, to avoid explicit
2579   /// PHI construction), but the type is the IR type, not the type appropriate
2580   /// for storing in memory.
2581   ///
2582   /// That is, this is exactly equivalent to CreateMemTemp, but calling
2583   /// ConvertType instead of ConvertTypeForMem.
2584   Address CreateIRTemp(QualType T, const Twine &Name = "tmp");
2585 
2586   /// CreateMemTemp - Create a temporary memory object of the given type, with
2587   /// appropriate alignmen and cast it to the default address space. Returns
2588   /// the original alloca instruction by \p Alloca if it is not nullptr.
2589   Address CreateMemTemp(QualType T, const Twine &Name = "tmp",
2590                         Address *Alloca = nullptr);
2591   Address CreateMemTemp(QualType T, CharUnits Align, const Twine &Name = "tmp",
2592                         Address *Alloca = nullptr);
2593 
2594   /// CreateMemTemp - Create a temporary memory object of the given type, with
2595   /// appropriate alignmen without casting it to the default address space.
2596   Address CreateMemTempWithoutCast(QualType T, const Twine &Name = "tmp");
2597   Address CreateMemTempWithoutCast(QualType T, CharUnits Align,
2598                                    const Twine &Name = "tmp");
2599 
2600   /// CreateAggTemp - Create a temporary memory object for the given
2601   /// aggregate type.
2602   AggValueSlot CreateAggTemp(QualType T, const Twine &Name = "tmp",
2603                              Address *Alloca = nullptr) {
2604     return AggValueSlot::forAddr(CreateMemTemp(T, Name, Alloca),
2605                                  T.getQualifiers(),
2606                                  AggValueSlot::IsNotDestructed,
2607                                  AggValueSlot::DoesNotNeedGCBarriers,
2608                                  AggValueSlot::IsNotAliased,
2609                                  AggValueSlot::DoesNotOverlap);
2610   }
2611 
2612   /// Emit a cast to void* in the appropriate address space.
2613   llvm::Value *EmitCastToVoidPtr(llvm::Value *value);
2614 
2615   /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
2616   /// expression and compare the result against zero, returning an Int1Ty value.
2617   llvm::Value *EvaluateExprAsBool(const Expr *E);
2618 
2619   /// EmitIgnoredExpr - Emit an expression in a context which ignores the result.
2620   void EmitIgnoredExpr(const Expr *E);
2621 
2622   /// EmitAnyExpr - Emit code to compute the specified expression which can have
2623   /// any type.  The result is returned as an RValue struct.  If this is an
2624   /// aggregate expression, the aggloc/agglocvolatile arguments indicate where
2625   /// the result should be returned.
2626   ///
2627   /// \param ignoreResult True if the resulting value isn't used.
2628   RValue EmitAnyExpr(const Expr *E,
2629                      AggValueSlot aggSlot = AggValueSlot::ignored(),
2630                      bool ignoreResult = false);
2631 
2632   // EmitVAListRef - Emit a "reference" to a va_list; this is either the address
2633   // or the value of the expression, depending on how va_list is defined.
2634   Address EmitVAListRef(const Expr *E);
2635 
2636   /// Emit a "reference" to a __builtin_ms_va_list; this is
2637   /// always the value of the expression, because a __builtin_ms_va_list is a
2638   /// pointer to a char.
2639   Address EmitMSVAListRef(const Expr *E);
2640 
2641   /// EmitAnyExprToTemp - Similarly to EmitAnyExpr(), however, the result will
2642   /// always be accessible even if no aggregate location is provided.
2643   RValue EmitAnyExprToTemp(const Expr *E);
2644 
2645   /// EmitAnyExprToMem - Emits the code necessary to evaluate an
2646   /// arbitrary expression into the given memory location.
2647   void EmitAnyExprToMem(const Expr *E, Address Location,
2648                         Qualifiers Quals, bool IsInitializer);
2649 
2650   void EmitAnyExprToExn(const Expr *E, Address Addr);
2651 
2652   /// EmitExprAsInit - Emits the code necessary to initialize a
2653   /// location in memory with the given initializer.
2654   void EmitExprAsInit(const Expr *init, const ValueDecl *D, LValue lvalue,
2655                       bool capturedByInit);
2656 
2657   /// hasVolatileMember - returns true if aggregate type has a volatile
2658   /// member.
2659   bool hasVolatileMember(QualType T) {
2660     if (const RecordType *RT = T->getAs<RecordType>()) {
2661       const RecordDecl *RD = cast<RecordDecl>(RT->getDecl());
2662       return RD->hasVolatileMember();
2663     }
2664     return false;
2665   }
2666 
2667   /// Determine whether a return value slot may overlap some other object.
2668   AggValueSlot::Overlap_t getOverlapForReturnValue() {
2669     // FIXME: Assuming no overlap here breaks guaranteed copy elision for base
2670     // class subobjects. These cases may need to be revisited depending on the
2671     // resolution of the relevant core issue.
2672     return AggValueSlot::DoesNotOverlap;
2673   }
2674 
2675   /// Determine whether a field initialization may overlap some other object.
2676   AggValueSlot::Overlap_t getOverlapForFieldInit(const FieldDecl *FD);
2677 
2678   /// Determine whether a base class initialization may overlap some other
2679   /// object.
2680   AggValueSlot::Overlap_t getOverlapForBaseInit(const CXXRecordDecl *RD,
2681                                                 const CXXRecordDecl *BaseRD,
2682                                                 bool IsVirtual);
2683 
2684   /// Emit an aggregate assignment.
2685   void EmitAggregateAssign(LValue Dest, LValue Src, QualType EltTy) {
2686     bool IsVolatile = hasVolatileMember(EltTy);
2687     EmitAggregateCopy(Dest, Src, EltTy, AggValueSlot::MayOverlap, IsVolatile);
2688   }
2689 
2690   void EmitAggregateCopyCtor(LValue Dest, LValue Src,
2691                              AggValueSlot::Overlap_t MayOverlap) {
2692     EmitAggregateCopy(Dest, Src, Src.getType(), MayOverlap);
2693   }
2694 
2695   /// EmitAggregateCopy - Emit an aggregate copy.
2696   ///
2697   /// \param isVolatile \c true iff either the source or the destination is
2698   ///        volatile.
2699   /// \param MayOverlap Whether the tail padding of the destination might be
2700   ///        occupied by some other object. More efficient code can often be
2701   ///        generated if not.
2702   void EmitAggregateCopy(LValue Dest, LValue Src, QualType EltTy,
2703                          AggValueSlot::Overlap_t MayOverlap,
2704                          bool isVolatile = false);
2705 
2706   /// GetAddrOfLocalVar - Return the address of a local variable.
2707   Address GetAddrOfLocalVar(const VarDecl *VD) {
2708     auto it = LocalDeclMap.find(VD);
2709     assert(it != LocalDeclMap.end() &&
2710            "Invalid argument to GetAddrOfLocalVar(), no decl!");
2711     return it->second;
2712   }
2713 
2714   /// Given an opaque value expression, return its LValue mapping if it exists,
2715   /// otherwise create one.
2716   LValue getOrCreateOpaqueLValueMapping(const OpaqueValueExpr *e);
2717 
2718   /// Given an opaque value expression, return its RValue mapping if it exists,
2719   /// otherwise create one.
2720   RValue getOrCreateOpaqueRValueMapping(const OpaqueValueExpr *e);
2721 
2722   /// Get the index of the current ArrayInitLoopExpr, if any.
2723   llvm::Value *getArrayInitIndex() { return ArrayInitIndex; }
2724 
2725   /// getAccessedFieldNo - Given an encoded value and a result number, return
2726   /// the input field number being accessed.
2727   static unsigned getAccessedFieldNo(unsigned Idx, const llvm::Constant *Elts);
2728 
2729   llvm::BlockAddress *GetAddrOfLabel(const LabelDecl *L);
2730   llvm::BasicBlock *GetIndirectGotoBlock();
2731 
2732   /// Check if \p E is a C++ "this" pointer wrapped in value-preserving casts.
2733   static bool IsWrappedCXXThis(const Expr *E);
2734 
2735   /// EmitNullInitialization - Generate code to set a value of the given type to
2736   /// null, If the type contains data member pointers, they will be initialized
2737   /// to -1 in accordance with the Itanium C++ ABI.
2738   void EmitNullInitialization(Address DestPtr, QualType Ty);
2739 
2740   /// Emits a call to an LLVM variable-argument intrinsic, either
2741   /// \c llvm.va_start or \c llvm.va_end.
2742   /// \param ArgValue A reference to the \c va_list as emitted by either
2743   /// \c EmitVAListRef or \c EmitMSVAListRef.
2744   /// \param IsStart If \c true, emits a call to \c llvm.va_start; otherwise,
2745   /// calls \c llvm.va_end.
2746   llvm::Value *EmitVAStartEnd(llvm::Value *ArgValue, bool IsStart);
2747 
2748   /// Generate code to get an argument from the passed in pointer
2749   /// and update it accordingly.
2750   /// \param VE The \c VAArgExpr for which to generate code.
2751   /// \param VAListAddr Receives a reference to the \c va_list as emitted by
2752   /// either \c EmitVAListRef or \c EmitMSVAListRef.
2753   /// \returns A pointer to the argument.
2754   // FIXME: We should be able to get rid of this method and use the va_arg
2755   // instruction in LLVM instead once it works well enough.
2756   Address EmitVAArg(VAArgExpr *VE, Address &VAListAddr);
2757 
2758   /// emitArrayLength - Compute the length of an array, even if it's a
2759   /// VLA, and drill down to the base element type.
2760   llvm::Value *emitArrayLength(const ArrayType *arrayType,
2761                                QualType &baseType,
2762                                Address &addr);
2763 
2764   /// EmitVLASize - Capture all the sizes for the VLA expressions in
2765   /// the given variably-modified type and store them in the VLASizeMap.
2766   ///
2767   /// This function can be called with a null (unreachable) insert point.
2768   void EmitVariablyModifiedType(QualType Ty);
2769 
2770   struct VlaSizePair {
2771     llvm::Value *NumElts;
2772     QualType Type;
2773 
2774     VlaSizePair(llvm::Value *NE, QualType T) : NumElts(NE), Type(T) {}
2775   };
2776 
2777   /// Return the number of elements for a single dimension
2778   /// for the given array type.
2779   VlaSizePair getVLAElements1D(const VariableArrayType *vla);
2780   VlaSizePair getVLAElements1D(QualType vla);
2781 
2782   /// Returns an LLVM value that corresponds to the size,
2783   /// in non-variably-sized elements, of a variable length array type,
2784   /// plus that largest non-variably-sized element type.  Assumes that
2785   /// the type has already been emitted with EmitVariablyModifiedType.
2786   VlaSizePair getVLASize(const VariableArrayType *vla);
2787   VlaSizePair getVLASize(QualType vla);
2788 
2789   /// LoadCXXThis - Load the value of 'this'. This function is only valid while
2790   /// generating code for an C++ member function.
2791   llvm::Value *LoadCXXThis() {
2792     assert(CXXThisValue && "no 'this' value for this function");
2793     return CXXThisValue;
2794   }
2795   Address LoadCXXThisAddress();
2796 
2797   /// LoadCXXVTT - Load the VTT parameter to base constructors/destructors have
2798   /// virtual bases.
2799   // FIXME: Every place that calls LoadCXXVTT is something
2800   // that needs to be abstracted properly.
2801   llvm::Value *LoadCXXVTT() {
2802     assert(CXXStructorImplicitParamValue && "no VTT value for this function");
2803     return CXXStructorImplicitParamValue;
2804   }
2805 
2806   /// GetAddressOfBaseOfCompleteClass - Convert the given pointer to a
2807   /// complete class to the given direct base.
2808   Address
2809   GetAddressOfDirectBaseInCompleteClass(Address Value,
2810                                         const CXXRecordDecl *Derived,
2811                                         const CXXRecordDecl *Base,
2812                                         bool BaseIsVirtual);
2813 
2814   static bool ShouldNullCheckClassCastValue(const CastExpr *Cast);
2815 
2816   /// GetAddressOfBaseClass - This function will add the necessary delta to the
2817   /// load of 'this' and returns address of the base class.
2818   Address GetAddressOfBaseClass(Address Value,
2819                                 const CXXRecordDecl *Derived,
2820                                 CastExpr::path_const_iterator PathBegin,
2821                                 CastExpr::path_const_iterator PathEnd,
2822                                 bool NullCheckValue, SourceLocation Loc);
2823 
2824   Address GetAddressOfDerivedClass(Address Value,
2825                                    const CXXRecordDecl *Derived,
2826                                    CastExpr::path_const_iterator PathBegin,
2827                                    CastExpr::path_const_iterator PathEnd,
2828                                    bool NullCheckValue);
2829 
2830   /// GetVTTParameter - Return the VTT parameter that should be passed to a
2831   /// base constructor/destructor with virtual bases.
2832   /// FIXME: VTTs are Itanium ABI-specific, so the definition should move
2833   /// to ItaniumCXXABI.cpp together with all the references to VTT.
2834   llvm::Value *GetVTTParameter(GlobalDecl GD, bool ForVirtualBase,
2835                                bool Delegating);
2836 
2837   void EmitDelegateCXXConstructorCall(const CXXConstructorDecl *Ctor,
2838                                       CXXCtorType CtorType,
2839                                       const FunctionArgList &Args,
2840                                       SourceLocation Loc);
2841   // It's important not to confuse this and the previous function. Delegating
2842   // constructors are the C++0x feature. The constructor delegate optimization
2843   // is used to reduce duplication in the base and complete consturctors where
2844   // they are substantially the same.
2845   void EmitDelegatingCXXConstructorCall(const CXXConstructorDecl *Ctor,
2846                                         const FunctionArgList &Args);
2847 
2848   /// Emit a call to an inheriting constructor (that is, one that invokes a
2849   /// constructor inherited from a base class) by inlining its definition. This
2850   /// is necessary if the ABI does not support forwarding the arguments to the
2851   /// base class constructor (because they're variadic or similar).
2852   void EmitInlinedInheritingCXXConstructorCall(const CXXConstructorDecl *Ctor,
2853                                                CXXCtorType CtorType,
2854                                                bool ForVirtualBase,
2855                                                bool Delegating,
2856                                                CallArgList &Args);
2857 
2858   /// Emit a call to a constructor inherited from a base class, passing the
2859   /// current constructor's arguments along unmodified (without even making
2860   /// a copy).
2861   void EmitInheritedCXXConstructorCall(const CXXConstructorDecl *D,
2862                                        bool ForVirtualBase, Address This,
2863                                        bool InheritedFromVBase,
2864                                        const CXXInheritedCtorInitExpr *E);
2865 
2866   void EmitCXXConstructorCall(const CXXConstructorDecl *D, CXXCtorType Type,
2867                               bool ForVirtualBase, bool Delegating,
2868                               AggValueSlot ThisAVS, const CXXConstructExpr *E);
2869 
2870   void EmitCXXConstructorCall(const CXXConstructorDecl *D, CXXCtorType Type,
2871                               bool ForVirtualBase, bool Delegating,
2872                               Address This, CallArgList &Args,
2873                               AggValueSlot::Overlap_t Overlap,
2874                               SourceLocation Loc, bool NewPointerIsChecked);
2875 
2876   /// Emit assumption load for all bases. Requires to be be called only on
2877   /// most-derived class and not under construction of the object.
2878   void EmitVTableAssumptionLoads(const CXXRecordDecl *ClassDecl, Address This);
2879 
2880   /// Emit assumption that vptr load == global vtable.
2881   void EmitVTableAssumptionLoad(const VPtr &vptr, Address This);
2882 
2883   void EmitSynthesizedCXXCopyCtorCall(const CXXConstructorDecl *D,
2884                                       Address This, Address Src,
2885                                       const CXXConstructExpr *E);
2886 
2887   void EmitCXXAggrConstructorCall(const CXXConstructorDecl *D,
2888                                   const ArrayType *ArrayTy,
2889                                   Address ArrayPtr,
2890                                   const CXXConstructExpr *E,
2891                                   bool NewPointerIsChecked,
2892                                   bool ZeroInitialization = false);
2893 
2894   void EmitCXXAggrConstructorCall(const CXXConstructorDecl *D,
2895                                   llvm::Value *NumElements,
2896                                   Address ArrayPtr,
2897                                   const CXXConstructExpr *E,
2898                                   bool NewPointerIsChecked,
2899                                   bool ZeroInitialization = false);
2900 
2901   static Destroyer destroyCXXObject;
2902 
2903   void EmitCXXDestructorCall(const CXXDestructorDecl *D, CXXDtorType Type,
2904                              bool ForVirtualBase, bool Delegating, Address This,
2905                              QualType ThisTy);
2906 
2907   void EmitNewArrayInitializer(const CXXNewExpr *E, QualType elementType,
2908                                llvm::Type *ElementTy, Address NewPtr,
2909                                llvm::Value *NumElements,
2910                                llvm::Value *AllocSizeWithoutCookie);
2911 
2912   void EmitCXXTemporary(const CXXTemporary *Temporary, QualType TempType,
2913                         Address Ptr);
2914 
2915   void EmitSehCppScopeBegin();
2916   void EmitSehCppScopeEnd();
2917   void EmitSehTryScopeBegin();
2918   void EmitSehTryScopeEnd();
2919 
2920   llvm::Value *EmitLifetimeStart(llvm::TypeSize Size, llvm::Value *Addr);
2921   void EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr);
2922 
2923   llvm::Value *EmitCXXNewExpr(const CXXNewExpr *E);
2924   void EmitCXXDeleteExpr(const CXXDeleteExpr *E);
2925 
2926   void EmitDeleteCall(const FunctionDecl *DeleteFD, llvm::Value *Ptr,
2927                       QualType DeleteTy, llvm::Value *NumElements = nullptr,
2928                       CharUnits CookieSize = CharUnits());
2929 
2930   RValue EmitBuiltinNewDeleteCall(const FunctionProtoType *Type,
2931                                   const CallExpr *TheCallExpr, bool IsDelete);
2932 
2933   llvm::Value *EmitCXXTypeidExpr(const CXXTypeidExpr *E);
2934   llvm::Value *EmitDynamicCast(Address V, const CXXDynamicCastExpr *DCE);
2935   Address EmitCXXUuidofExpr(const CXXUuidofExpr *E);
2936 
2937   /// Situations in which we might emit a check for the suitability of a
2938   /// pointer or glvalue. Needs to be kept in sync with ubsan_handlers.cpp in
2939   /// compiler-rt.
2940   enum TypeCheckKind {
2941     /// Checking the operand of a load. Must be suitably sized and aligned.
2942     TCK_Load,
2943     /// Checking the destination of a store. Must be suitably sized and aligned.
2944     TCK_Store,
2945     /// Checking the bound value in a reference binding. Must be suitably sized
2946     /// and aligned, but is not required to refer to an object (until the
2947     /// reference is used), per core issue 453.
2948     TCK_ReferenceBinding,
2949     /// Checking the object expression in a non-static data member access. Must
2950     /// be an object within its lifetime.
2951     TCK_MemberAccess,
2952     /// Checking the 'this' pointer for a call to a non-static member function.
2953     /// Must be an object within its lifetime.
2954     TCK_MemberCall,
2955     /// Checking the 'this' pointer for a constructor call.
2956     TCK_ConstructorCall,
2957     /// Checking the operand of a static_cast to a derived pointer type. Must be
2958     /// null or an object within its lifetime.
2959     TCK_DowncastPointer,
2960     /// Checking the operand of a static_cast to a derived reference type. Must
2961     /// be an object within its lifetime.
2962     TCK_DowncastReference,
2963     /// Checking the operand of a cast to a base object. Must be suitably sized
2964     /// and aligned.
2965     TCK_Upcast,
2966     /// Checking the operand of a cast to a virtual base object. Must be an
2967     /// object within its lifetime.
2968     TCK_UpcastToVirtualBase,
2969     /// Checking the value assigned to a _Nonnull pointer. Must not be null.
2970     TCK_NonnullAssign,
2971     /// Checking the operand of a dynamic_cast or a typeid expression.  Must be
2972     /// null or an object within its lifetime.
2973     TCK_DynamicOperation
2974   };
2975 
2976   /// Determine whether the pointer type check \p TCK permits null pointers.
2977   static bool isNullPointerAllowed(TypeCheckKind TCK);
2978 
2979   /// Determine whether the pointer type check \p TCK requires a vptr check.
2980   static bool isVptrCheckRequired(TypeCheckKind TCK, QualType Ty);
2981 
2982   /// Whether any type-checking sanitizers are enabled. If \c false,
2983   /// calls to EmitTypeCheck can be skipped.
2984   bool sanitizePerformTypeCheck() const;
2985 
2986   /// Emit a check that \p V is the address of storage of the
2987   /// appropriate size and alignment for an object of type \p Type
2988   /// (or if ArraySize is provided, for an array of that bound).
2989   void EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc, llvm::Value *V,
2990                      QualType Type, CharUnits Alignment = CharUnits::Zero(),
2991                      SanitizerSet SkippedChecks = SanitizerSet(),
2992                      llvm::Value *ArraySize = nullptr);
2993 
2994   /// Emit a check that \p Base points into an array object, which
2995   /// we can access at index \p Index. \p Accessed should be \c false if we
2996   /// this expression is used as an lvalue, for instance in "&Arr[Idx]".
2997   void EmitBoundsCheck(const Expr *E, const Expr *Base, llvm::Value *Index,
2998                        QualType IndexType, bool Accessed);
2999 
3000   llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
3001                                        bool isInc, bool isPre);
3002   ComplexPairTy EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
3003                                          bool isInc, bool isPre);
3004 
3005   /// Converts Location to a DebugLoc, if debug information is enabled.
3006   llvm::DebugLoc SourceLocToDebugLoc(SourceLocation Location);
3007 
3008   /// Get the record field index as represented in debug info.
3009   unsigned getDebugInfoFIndex(const RecordDecl *Rec, unsigned FieldIndex);
3010 
3011 
3012   //===--------------------------------------------------------------------===//
3013   //                            Declaration Emission
3014   //===--------------------------------------------------------------------===//
3015 
3016   /// EmitDecl - Emit a declaration.
3017   ///
3018   /// This function can be called with a null (unreachable) insert point.
3019   void EmitDecl(const Decl &D);
3020 
3021   /// EmitVarDecl - Emit a local variable declaration.
3022   ///
3023   /// This function can be called with a null (unreachable) insert point.
3024   void EmitVarDecl(const VarDecl &D);
3025 
3026   void EmitScalarInit(const Expr *init, const ValueDecl *D, LValue lvalue,
3027                       bool capturedByInit);
3028 
3029   typedef void SpecialInitFn(CodeGenFunction &Init, const VarDecl &D,
3030                              llvm::Value *Address);
3031 
3032   /// Determine whether the given initializer is trivial in the sense
3033   /// that it requires no code to be generated.
3034   bool isTrivialInitializer(const Expr *Init);
3035 
3036   /// EmitAutoVarDecl - Emit an auto variable declaration.
3037   ///
3038   /// This function can be called with a null (unreachable) insert point.
3039   void EmitAutoVarDecl(const VarDecl &D);
3040 
3041   class AutoVarEmission {
3042     friend class CodeGenFunction;
3043 
3044     const VarDecl *Variable;
3045 
3046     /// The address of the alloca for languages with explicit address space
3047     /// (e.g. OpenCL) or alloca casted to generic pointer for address space
3048     /// agnostic languages (e.g. C++). Invalid if the variable was emitted
3049     /// as a global constant.
3050     Address Addr;
3051 
3052     llvm::Value *NRVOFlag;
3053 
3054     /// True if the variable is a __block variable that is captured by an
3055     /// escaping block.
3056     bool IsEscapingByRef;
3057 
3058     /// True if the variable is of aggregate type and has a constant
3059     /// initializer.
3060     bool IsConstantAggregate;
3061 
3062     /// Non-null if we should use lifetime annotations.
3063     llvm::Value *SizeForLifetimeMarkers;
3064 
3065     /// Address with original alloca instruction. Invalid if the variable was
3066     /// emitted as a global constant.
3067     Address AllocaAddr;
3068 
3069     struct Invalid {};
3070     AutoVarEmission(Invalid)
3071         : Variable(nullptr), Addr(Address::invalid()),
3072           AllocaAddr(Address::invalid()) {}
3073 
3074     AutoVarEmission(const VarDecl &variable)
3075         : Variable(&variable), Addr(Address::invalid()), NRVOFlag(nullptr),
3076           IsEscapingByRef(false), IsConstantAggregate(false),
3077           SizeForLifetimeMarkers(nullptr), AllocaAddr(Address::invalid()) {}
3078 
3079     bool wasEmittedAsGlobal() const { return !Addr.isValid(); }
3080 
3081   public:
3082     static AutoVarEmission invalid() { return AutoVarEmission(Invalid()); }
3083 
3084     bool useLifetimeMarkers() const {
3085       return SizeForLifetimeMarkers != nullptr;
3086     }
3087     llvm::Value *getSizeForLifetimeMarkers() const {
3088       assert(useLifetimeMarkers());
3089       return SizeForLifetimeMarkers;
3090     }
3091 
3092     /// Returns the raw, allocated address, which is not necessarily
3093     /// the address of the object itself. It is casted to default
3094     /// address space for address space agnostic languages.
3095     Address getAllocatedAddress() const {
3096       return Addr;
3097     }
3098 
3099     /// Returns the address for the original alloca instruction.
3100     Address getOriginalAllocatedAddress() const { return AllocaAddr; }
3101 
3102     /// Returns the address of the object within this declaration.
3103     /// Note that this does not chase the forwarding pointer for
3104     /// __block decls.
3105     Address getObjectAddress(CodeGenFunction &CGF) const {
3106       if (!IsEscapingByRef) return Addr;
3107 
3108       return CGF.emitBlockByrefAddress(Addr, Variable, /*forward*/ false);
3109     }
3110   };
3111   AutoVarEmission EmitAutoVarAlloca(const VarDecl &var);
3112   void EmitAutoVarInit(const AutoVarEmission &emission);
3113   void EmitAutoVarCleanups(const AutoVarEmission &emission);
3114   void emitAutoVarTypeCleanup(const AutoVarEmission &emission,
3115                               QualType::DestructionKind dtorKind);
3116 
3117   /// Emits the alloca and debug information for the size expressions for each
3118   /// dimension of an array. It registers the association of its (1-dimensional)
3119   /// QualTypes and size expression's debug node, so that CGDebugInfo can
3120   /// reference this node when creating the DISubrange object to describe the
3121   /// array types.
3122   void EmitAndRegisterVariableArrayDimensions(CGDebugInfo *DI,
3123                                               const VarDecl &D,
3124                                               bool EmitDebugInfo);
3125 
3126   void EmitStaticVarDecl(const VarDecl &D,
3127                          llvm::GlobalValue::LinkageTypes Linkage);
3128 
3129   class ParamValue {
3130     llvm::Value *Value;
3131     unsigned Alignment;
3132     ParamValue(llvm::Value *V, unsigned A) : Value(V), Alignment(A) {}
3133   public:
3134     static ParamValue forDirect(llvm::Value *value) {
3135       return ParamValue(value, 0);
3136     }
3137     static ParamValue forIndirect(Address addr) {
3138       assert(!addr.getAlignment().isZero());
3139       return ParamValue(addr.getPointer(), addr.getAlignment().getQuantity());
3140     }
3141 
3142     bool isIndirect() const { return Alignment != 0; }
3143     llvm::Value *getAnyValue() const { return Value; }
3144 
3145     llvm::Value *getDirectValue() const {
3146       assert(!isIndirect());
3147       return Value;
3148     }
3149 
3150     Address getIndirectAddress() const {
3151       assert(isIndirect());
3152       return Address(Value, CharUnits::fromQuantity(Alignment));
3153     }
3154   };
3155 
3156   /// EmitParmDecl - Emit a ParmVarDecl or an ImplicitParamDecl.
3157   void EmitParmDecl(const VarDecl &D, ParamValue Arg, unsigned ArgNo);
3158 
3159   /// protectFromPeepholes - Protect a value that we're intending to
3160   /// store to the side, but which will probably be used later, from
3161   /// aggressive peepholing optimizations that might delete it.
3162   ///
3163   /// Pass the result to unprotectFromPeepholes to declare that
3164   /// protection is no longer required.
3165   ///
3166   /// There's no particular reason why this shouldn't apply to
3167   /// l-values, it's just that no existing peepholes work on pointers.
3168   PeepholeProtection protectFromPeepholes(RValue rvalue);
3169   void unprotectFromPeepholes(PeepholeProtection protection);
3170 
3171   void emitAlignmentAssumptionCheck(llvm::Value *Ptr, QualType Ty,
3172                                     SourceLocation Loc,
3173                                     SourceLocation AssumptionLoc,
3174                                     llvm::Value *Alignment,
3175                                     llvm::Value *OffsetValue,
3176                                     llvm::Value *TheCheck,
3177                                     llvm::Instruction *Assumption);
3178 
3179   void emitAlignmentAssumption(llvm::Value *PtrValue, QualType Ty,
3180                                SourceLocation Loc, SourceLocation AssumptionLoc,
3181                                llvm::Value *Alignment,
3182                                llvm::Value *OffsetValue = nullptr);
3183 
3184   void emitAlignmentAssumption(llvm::Value *PtrValue, const Expr *E,
3185                                SourceLocation AssumptionLoc,
3186                                llvm::Value *Alignment,
3187                                llvm::Value *OffsetValue = nullptr);
3188 
3189   //===--------------------------------------------------------------------===//
3190   //                             Statement Emission
3191   //===--------------------------------------------------------------------===//
3192 
3193   /// EmitStopPoint - Emit a debug stoppoint if we are emitting debug info.
3194   void EmitStopPoint(const Stmt *S);
3195 
3196   /// EmitStmt - Emit the code for the statement \arg S. It is legal to call
3197   /// this function even if there is no current insertion point.
3198   ///
3199   /// This function may clear the current insertion point; callers should use
3200   /// EnsureInsertPoint if they wish to subsequently generate code without first
3201   /// calling EmitBlock, EmitBranch, or EmitStmt.
3202   void EmitStmt(const Stmt *S, ArrayRef<const Attr *> Attrs = None);
3203 
3204   /// EmitSimpleStmt - Try to emit a "simple" statement which does not
3205   /// necessarily require an insertion point or debug information; typically
3206   /// because the statement amounts to a jump or a container of other
3207   /// statements.
3208   ///
3209   /// \return True if the statement was handled.
3210   bool EmitSimpleStmt(const Stmt *S, ArrayRef<const Attr *> Attrs);
3211 
3212   Address EmitCompoundStmt(const CompoundStmt &S, bool GetLast = false,
3213                            AggValueSlot AVS = AggValueSlot::ignored());
3214   Address EmitCompoundStmtWithoutScope(const CompoundStmt &S,
3215                                        bool GetLast = false,
3216                                        AggValueSlot AVS =
3217                                                 AggValueSlot::ignored());
3218 
3219   /// EmitLabel - Emit the block for the given label. It is legal to call this
3220   /// function even if there is no current insertion point.
3221   void EmitLabel(const LabelDecl *D); // helper for EmitLabelStmt.
3222 
3223   void EmitLabelStmt(const LabelStmt &S);
3224   void EmitAttributedStmt(const AttributedStmt &S);
3225   void EmitGotoStmt(const GotoStmt &S);
3226   void EmitIndirectGotoStmt(const IndirectGotoStmt &S);
3227   void EmitIfStmt(const IfStmt &S);
3228 
3229   void EmitWhileStmt(const WhileStmt &S,
3230                      ArrayRef<const Attr *> Attrs = None);
3231   void EmitDoStmt(const DoStmt &S, ArrayRef<const Attr *> Attrs = None);
3232   void EmitForStmt(const ForStmt &S,
3233                    ArrayRef<const Attr *> Attrs = None);
3234   void EmitReturnStmt(const ReturnStmt &S);
3235   void EmitDeclStmt(const DeclStmt &S);
3236   void EmitBreakStmt(const BreakStmt &S);
3237   void EmitContinueStmt(const ContinueStmt &S);
3238   void EmitSwitchStmt(const SwitchStmt &S);
3239   void EmitDefaultStmt(const DefaultStmt &S, ArrayRef<const Attr *> Attrs);
3240   void EmitCaseStmt(const CaseStmt &S, ArrayRef<const Attr *> Attrs);
3241   void EmitCaseStmtRange(const CaseStmt &S, ArrayRef<const Attr *> Attrs);
3242   void EmitAsmStmt(const AsmStmt &S);
3243 
3244   void EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S);
3245   void EmitObjCAtTryStmt(const ObjCAtTryStmt &S);
3246   void EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S);
3247   void EmitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt &S);
3248   void EmitObjCAutoreleasePoolStmt(const ObjCAutoreleasePoolStmt &S);
3249 
3250   void EmitCoroutineBody(const CoroutineBodyStmt &S);
3251   void EmitCoreturnStmt(const CoreturnStmt &S);
3252   RValue EmitCoawaitExpr(const CoawaitExpr &E,
3253                          AggValueSlot aggSlot = AggValueSlot::ignored(),
3254                          bool ignoreResult = false);
3255   LValue EmitCoawaitLValue(const CoawaitExpr *E);
3256   RValue EmitCoyieldExpr(const CoyieldExpr &E,
3257                          AggValueSlot aggSlot = AggValueSlot::ignored(),
3258                          bool ignoreResult = false);
3259   LValue EmitCoyieldLValue(const CoyieldExpr *E);
3260   RValue EmitCoroutineIntrinsic(const CallExpr *E, unsigned int IID);
3261 
3262   void EnterCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
3263   void ExitCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
3264 
3265   void EmitCXXTryStmt(const CXXTryStmt &S);
3266   void EmitSEHTryStmt(const SEHTryStmt &S);
3267   void EmitSEHLeaveStmt(const SEHLeaveStmt &S);
3268   void EnterSEHTryStmt(const SEHTryStmt &S);
3269   void ExitSEHTryStmt(const SEHTryStmt &S);
3270   void VolatilizeTryBlocks(llvm::BasicBlock *BB,
3271                            llvm::SmallPtrSet<llvm::BasicBlock *, 10> &V);
3272 
3273   void pushSEHCleanup(CleanupKind kind,
3274                       llvm::Function *FinallyFunc);
3275   void startOutlinedSEHHelper(CodeGenFunction &ParentCGF, bool IsFilter,
3276                               const Stmt *OutlinedStmt);
3277 
3278   llvm::Function *GenerateSEHFilterFunction(CodeGenFunction &ParentCGF,
3279                                             const SEHExceptStmt &Except);
3280 
3281   llvm::Function *GenerateSEHFinallyFunction(CodeGenFunction &ParentCGF,
3282                                              const SEHFinallyStmt &Finally);
3283 
3284   void EmitSEHExceptionCodeSave(CodeGenFunction &ParentCGF,
3285                                 llvm::Value *ParentFP,
3286                                 llvm::Value *EntryEBP);
3287   llvm::Value *EmitSEHExceptionCode();
3288   llvm::Value *EmitSEHExceptionInfo();
3289   llvm::Value *EmitSEHAbnormalTermination();
3290 
3291   /// Emit simple code for OpenMP directives in Simd-only mode.
3292   void EmitSimpleOMPExecutableDirective(const OMPExecutableDirective &D);
3293 
3294   /// Scan the outlined statement for captures from the parent function. For
3295   /// each capture, mark the capture as escaped and emit a call to
3296   /// llvm.localrecover. Insert the localrecover result into the LocalDeclMap.
3297   void EmitCapturedLocals(CodeGenFunction &ParentCGF, const Stmt *OutlinedStmt,
3298                           bool IsFilter);
3299 
3300   /// Recovers the address of a local in a parent function. ParentVar is the
3301   /// address of the variable used in the immediate parent function. It can
3302   /// either be an alloca or a call to llvm.localrecover if there are nested
3303   /// outlined functions. ParentFP is the frame pointer of the outermost parent
3304   /// frame.
3305   Address recoverAddrOfEscapedLocal(CodeGenFunction &ParentCGF,
3306                                     Address ParentVar,
3307                                     llvm::Value *ParentFP);
3308 
3309   void EmitCXXForRangeStmt(const CXXForRangeStmt &S,
3310                            ArrayRef<const Attr *> Attrs = None);
3311 
3312   /// Controls insertion of cancellation exit blocks in worksharing constructs.
3313   class OMPCancelStackRAII {
3314     CodeGenFunction &CGF;
3315 
3316   public:
3317     OMPCancelStackRAII(CodeGenFunction &CGF, OpenMPDirectiveKind Kind,
3318                        bool HasCancel)
3319         : CGF(CGF) {
3320       CGF.OMPCancelStack.enter(CGF, Kind, HasCancel);
3321     }
3322     ~OMPCancelStackRAII() { CGF.OMPCancelStack.exit(CGF); }
3323   };
3324 
3325   /// Returns calculated size of the specified type.
3326   llvm::Value *getTypeSize(QualType Ty);
3327   LValue InitCapturedStruct(const CapturedStmt &S);
3328   llvm::Function *EmitCapturedStmt(const CapturedStmt &S, CapturedRegionKind K);
3329   llvm::Function *GenerateCapturedStmtFunction(const CapturedStmt &S);
3330   Address GenerateCapturedStmtArgument(const CapturedStmt &S);
3331   llvm::Function *GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S,
3332                                                      SourceLocation Loc);
3333   void GenerateOpenMPCapturedVars(const CapturedStmt &S,
3334                                   SmallVectorImpl<llvm::Value *> &CapturedVars);
3335   void emitOMPSimpleStore(LValue LVal, RValue RVal, QualType RValTy,
3336                           SourceLocation Loc);
3337   /// Perform element by element copying of arrays with type \a
3338   /// OriginalType from \a SrcAddr to \a DestAddr using copying procedure
3339   /// generated by \a CopyGen.
3340   ///
3341   /// \param DestAddr Address of the destination array.
3342   /// \param SrcAddr Address of the source array.
3343   /// \param OriginalType Type of destination and source arrays.
3344   /// \param CopyGen Copying procedure that copies value of single array element
3345   /// to another single array element.
3346   void EmitOMPAggregateAssign(
3347       Address DestAddr, Address SrcAddr, QualType OriginalType,
3348       const llvm::function_ref<void(Address, Address)> CopyGen);
3349   /// Emit proper copying of data from one variable to another.
3350   ///
3351   /// \param OriginalType Original type of the copied variables.
3352   /// \param DestAddr Destination address.
3353   /// \param SrcAddr Source address.
3354   /// \param DestVD Destination variable used in \a CopyExpr (for arrays, has
3355   /// type of the base array element).
3356   /// \param SrcVD Source variable used in \a CopyExpr (for arrays, has type of
3357   /// the base array element).
3358   /// \param Copy Actual copygin expression for copying data from \a SrcVD to \a
3359   /// DestVD.
3360   void EmitOMPCopy(QualType OriginalType,
3361                    Address DestAddr, Address SrcAddr,
3362                    const VarDecl *DestVD, const VarDecl *SrcVD,
3363                    const Expr *Copy);
3364   /// Emit atomic update code for constructs: \a X = \a X \a BO \a E or
3365   /// \a X = \a E \a BO \a E.
3366   ///
3367   /// \param X Value to be updated.
3368   /// \param E Update value.
3369   /// \param BO Binary operation for update operation.
3370   /// \param IsXLHSInRHSPart true if \a X is LHS in RHS part of the update
3371   /// expression, false otherwise.
3372   /// \param AO Atomic ordering of the generated atomic instructions.
3373   /// \param CommonGen Code generator for complex expressions that cannot be
3374   /// expressed through atomicrmw instruction.
3375   /// \returns <true, OldAtomicValue> if simple 'atomicrmw' instruction was
3376   /// generated, <false, RValue::get(nullptr)> otherwise.
3377   std::pair<bool, RValue> EmitOMPAtomicSimpleUpdateExpr(
3378       LValue X, RValue E, BinaryOperatorKind BO, bool IsXLHSInRHSPart,
3379       llvm::AtomicOrdering AO, SourceLocation Loc,
3380       const llvm::function_ref<RValue(RValue)> CommonGen);
3381   bool EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
3382                                  OMPPrivateScope &PrivateScope);
3383   void EmitOMPPrivateClause(const OMPExecutableDirective &D,
3384                             OMPPrivateScope &PrivateScope);
3385   void EmitOMPUseDevicePtrClause(
3386       const OMPUseDevicePtrClause &C, OMPPrivateScope &PrivateScope,
3387       const llvm::DenseMap<const ValueDecl *, Address> &CaptureDeviceAddrMap);
3388   void EmitOMPUseDeviceAddrClause(
3389       const OMPUseDeviceAddrClause &C, OMPPrivateScope &PrivateScope,
3390       const llvm::DenseMap<const ValueDecl *, Address> &CaptureDeviceAddrMap);
3391   /// Emit code for copyin clause in \a D directive. The next code is
3392   /// generated at the start of outlined functions for directives:
3393   /// \code
3394   /// threadprivate_var1 = master_threadprivate_var1;
3395   /// operator=(threadprivate_var2, master_threadprivate_var2);
3396   /// ...
3397   /// __kmpc_barrier(&loc, global_tid);
3398   /// \endcode
3399   ///
3400   /// \param D OpenMP directive possibly with 'copyin' clause(s).
3401   /// \returns true if at least one copyin variable is found, false otherwise.
3402   bool EmitOMPCopyinClause(const OMPExecutableDirective &D);
3403   /// Emit initial code for lastprivate variables. If some variable is
3404   /// not also firstprivate, then the default initialization is used. Otherwise
3405   /// initialization of this variable is performed by EmitOMPFirstprivateClause
3406   /// method.
3407   ///
3408   /// \param D Directive that may have 'lastprivate' directives.
3409   /// \param PrivateScope Private scope for capturing lastprivate variables for
3410   /// proper codegen in internal captured statement.
3411   ///
3412   /// \returns true if there is at least one lastprivate variable, false
3413   /// otherwise.
3414   bool EmitOMPLastprivateClauseInit(const OMPExecutableDirective &D,
3415                                     OMPPrivateScope &PrivateScope);
3416   /// Emit final copying of lastprivate values to original variables at
3417   /// the end of the worksharing or simd directive.
3418   ///
3419   /// \param D Directive that has at least one 'lastprivate' directives.
3420   /// \param IsLastIterCond Boolean condition that must be set to 'i1 true' if
3421   /// it is the last iteration of the loop code in associated directive, or to
3422   /// 'i1 false' otherwise. If this item is nullptr, no final check is required.
3423   void EmitOMPLastprivateClauseFinal(const OMPExecutableDirective &D,
3424                                      bool NoFinals,
3425                                      llvm::Value *IsLastIterCond = nullptr);
3426   /// Emit initial code for linear clauses.
3427   void EmitOMPLinearClause(const OMPLoopDirective &D,
3428                            CodeGenFunction::OMPPrivateScope &PrivateScope);
3429   /// Emit final code for linear clauses.
3430   /// \param CondGen Optional conditional code for final part of codegen for
3431   /// linear clause.
3432   void EmitOMPLinearClauseFinal(
3433       const OMPLoopDirective &D,
3434       const llvm::function_ref<llvm::Value *(CodeGenFunction &)> CondGen);
3435   /// Emit initial code for reduction variables. Creates reduction copies
3436   /// and initializes them with the values according to OpenMP standard.
3437   ///
3438   /// \param D Directive (possibly) with the 'reduction' clause.
3439   /// \param PrivateScope Private scope for capturing reduction variables for
3440   /// proper codegen in internal captured statement.
3441   ///
3442   void EmitOMPReductionClauseInit(const OMPExecutableDirective &D,
3443                                   OMPPrivateScope &PrivateScope,
3444                                   bool ForInscan = false);
3445   /// Emit final update of reduction values to original variables at
3446   /// the end of the directive.
3447   ///
3448   /// \param D Directive that has at least one 'reduction' directives.
3449   /// \param ReductionKind The kind of reduction to perform.
3450   void EmitOMPReductionClauseFinal(const OMPExecutableDirective &D,
3451                                    const OpenMPDirectiveKind ReductionKind);
3452   /// Emit initial code for linear variables. Creates private copies
3453   /// and initializes them with the values according to OpenMP standard.
3454   ///
3455   /// \param D Directive (possibly) with the 'linear' clause.
3456   /// \return true if at least one linear variable is found that should be
3457   /// initialized with the value of the original variable, false otherwise.
3458   bool EmitOMPLinearClauseInit(const OMPLoopDirective &D);
3459 
3460   typedef const llvm::function_ref<void(CodeGenFunction & /*CGF*/,
3461                                         llvm::Function * /*OutlinedFn*/,
3462                                         const OMPTaskDataTy & /*Data*/)>
3463       TaskGenTy;
3464   void EmitOMPTaskBasedDirective(const OMPExecutableDirective &S,
3465                                  const OpenMPDirectiveKind CapturedRegion,
3466                                  const RegionCodeGenTy &BodyGen,
3467                                  const TaskGenTy &TaskGen, OMPTaskDataTy &Data);
3468   struct OMPTargetDataInfo {
3469     Address BasePointersArray = Address::invalid();
3470     Address PointersArray = Address::invalid();
3471     Address SizesArray = Address::invalid();
3472     Address MappersArray = Address::invalid();
3473     unsigned NumberOfTargetItems = 0;
3474     explicit OMPTargetDataInfo() = default;
3475     OMPTargetDataInfo(Address BasePointersArray, Address PointersArray,
3476                       Address SizesArray, Address MappersArray,
3477                       unsigned NumberOfTargetItems)
3478         : BasePointersArray(BasePointersArray), PointersArray(PointersArray),
3479           SizesArray(SizesArray), MappersArray(MappersArray),
3480           NumberOfTargetItems(NumberOfTargetItems) {}
3481   };
3482   void EmitOMPTargetTaskBasedDirective(const OMPExecutableDirective &S,
3483                                        const RegionCodeGenTy &BodyGen,
3484                                        OMPTargetDataInfo &InputInfo);
3485 
3486   void EmitOMPMetaDirective(const OMPMetaDirective &S);
3487   void EmitOMPParallelDirective(const OMPParallelDirective &S);
3488   void EmitOMPSimdDirective(const OMPSimdDirective &S);
3489   void EmitOMPTileDirective(const OMPTileDirective &S);
3490   void EmitOMPUnrollDirective(const OMPUnrollDirective &S);
3491   void EmitOMPForDirective(const OMPForDirective &S);
3492   void EmitOMPForSimdDirective(const OMPForSimdDirective &S);
3493   void EmitOMPSectionsDirective(const OMPSectionsDirective &S);
3494   void EmitOMPSectionDirective(const OMPSectionDirective &S);
3495   void EmitOMPSingleDirective(const OMPSingleDirective &S);
3496   void EmitOMPMasterDirective(const OMPMasterDirective &S);
3497   void EmitOMPMaskedDirective(const OMPMaskedDirective &S);
3498   void EmitOMPCriticalDirective(const OMPCriticalDirective &S);
3499   void EmitOMPParallelForDirective(const OMPParallelForDirective &S);
3500   void EmitOMPParallelForSimdDirective(const OMPParallelForSimdDirective &S);
3501   void EmitOMPParallelSectionsDirective(const OMPParallelSectionsDirective &S);
3502   void EmitOMPParallelMasterDirective(const OMPParallelMasterDirective &S);
3503   void EmitOMPTaskDirective(const OMPTaskDirective &S);
3504   void EmitOMPTaskyieldDirective(const OMPTaskyieldDirective &S);
3505   void EmitOMPBarrierDirective(const OMPBarrierDirective &S);
3506   void EmitOMPTaskwaitDirective(const OMPTaskwaitDirective &S);
3507   void EmitOMPTaskgroupDirective(const OMPTaskgroupDirective &S);
3508   void EmitOMPFlushDirective(const OMPFlushDirective &S);
3509   void EmitOMPDepobjDirective(const OMPDepobjDirective &S);
3510   void EmitOMPScanDirective(const OMPScanDirective &S);
3511   void EmitOMPOrderedDirective(const OMPOrderedDirective &S);
3512   void EmitOMPAtomicDirective(const OMPAtomicDirective &S);
3513   void EmitOMPTargetDirective(const OMPTargetDirective &S);
3514   void EmitOMPTargetDataDirective(const OMPTargetDataDirective &S);
3515   void EmitOMPTargetEnterDataDirective(const OMPTargetEnterDataDirective &S);
3516   void EmitOMPTargetExitDataDirective(const OMPTargetExitDataDirective &S);
3517   void EmitOMPTargetUpdateDirective(const OMPTargetUpdateDirective &S);
3518   void EmitOMPTargetParallelDirective(const OMPTargetParallelDirective &S);
3519   void
3520   EmitOMPTargetParallelForDirective(const OMPTargetParallelForDirective &S);
3521   void EmitOMPTeamsDirective(const OMPTeamsDirective &S);
3522   void
3523   EmitOMPCancellationPointDirective(const OMPCancellationPointDirective &S);
3524   void EmitOMPCancelDirective(const OMPCancelDirective &S);
3525   void EmitOMPTaskLoopBasedDirective(const OMPLoopDirective &S);
3526   void EmitOMPTaskLoopDirective(const OMPTaskLoopDirective &S);
3527   void EmitOMPTaskLoopSimdDirective(const OMPTaskLoopSimdDirective &S);
3528   void EmitOMPMasterTaskLoopDirective(const OMPMasterTaskLoopDirective &S);
3529   void
3530   EmitOMPMasterTaskLoopSimdDirective(const OMPMasterTaskLoopSimdDirective &S);
3531   void EmitOMPParallelMasterTaskLoopDirective(
3532       const OMPParallelMasterTaskLoopDirective &S);
3533   void EmitOMPParallelMasterTaskLoopSimdDirective(
3534       const OMPParallelMasterTaskLoopSimdDirective &S);
3535   void EmitOMPDistributeDirective(const OMPDistributeDirective &S);
3536   void EmitOMPDistributeParallelForDirective(
3537       const OMPDistributeParallelForDirective &S);
3538   void EmitOMPDistributeParallelForSimdDirective(
3539       const OMPDistributeParallelForSimdDirective &S);
3540   void EmitOMPDistributeSimdDirective(const OMPDistributeSimdDirective &S);
3541   void EmitOMPTargetParallelForSimdDirective(
3542       const OMPTargetParallelForSimdDirective &S);
3543   void EmitOMPTargetSimdDirective(const OMPTargetSimdDirective &S);
3544   void EmitOMPTeamsDistributeDirective(const OMPTeamsDistributeDirective &S);
3545   void
3546   EmitOMPTeamsDistributeSimdDirective(const OMPTeamsDistributeSimdDirective &S);
3547   void EmitOMPTeamsDistributeParallelForSimdDirective(
3548       const OMPTeamsDistributeParallelForSimdDirective &S);
3549   void EmitOMPTeamsDistributeParallelForDirective(
3550       const OMPTeamsDistributeParallelForDirective &S);
3551   void EmitOMPTargetTeamsDirective(const OMPTargetTeamsDirective &S);
3552   void EmitOMPTargetTeamsDistributeDirective(
3553       const OMPTargetTeamsDistributeDirective &S);
3554   void EmitOMPTargetTeamsDistributeParallelForDirective(
3555       const OMPTargetTeamsDistributeParallelForDirective &S);
3556   void EmitOMPTargetTeamsDistributeParallelForSimdDirective(
3557       const OMPTargetTeamsDistributeParallelForSimdDirective &S);
3558   void EmitOMPTargetTeamsDistributeSimdDirective(
3559       const OMPTargetTeamsDistributeSimdDirective &S);
3560   void EmitOMPGenericLoopDirective(const OMPGenericLoopDirective &S);
3561 
3562   /// Emit device code for the target directive.
3563   static void EmitOMPTargetDeviceFunction(CodeGenModule &CGM,
3564                                           StringRef ParentName,
3565                                           const OMPTargetDirective &S);
3566   static void
3567   EmitOMPTargetParallelDeviceFunction(CodeGenModule &CGM, StringRef ParentName,
3568                                       const OMPTargetParallelDirective &S);
3569   /// Emit device code for the target parallel for directive.
3570   static void EmitOMPTargetParallelForDeviceFunction(
3571       CodeGenModule &CGM, StringRef ParentName,
3572       const OMPTargetParallelForDirective &S);
3573   /// Emit device code for the target parallel for simd directive.
3574   static void EmitOMPTargetParallelForSimdDeviceFunction(
3575       CodeGenModule &CGM, StringRef ParentName,
3576       const OMPTargetParallelForSimdDirective &S);
3577   /// Emit device code for the target teams directive.
3578   static void
3579   EmitOMPTargetTeamsDeviceFunction(CodeGenModule &CGM, StringRef ParentName,
3580                                    const OMPTargetTeamsDirective &S);
3581   /// Emit device code for the target teams distribute directive.
3582   static void EmitOMPTargetTeamsDistributeDeviceFunction(
3583       CodeGenModule &CGM, StringRef ParentName,
3584       const OMPTargetTeamsDistributeDirective &S);
3585   /// Emit device code for the target teams distribute simd directive.
3586   static void EmitOMPTargetTeamsDistributeSimdDeviceFunction(
3587       CodeGenModule &CGM, StringRef ParentName,
3588       const OMPTargetTeamsDistributeSimdDirective &S);
3589   /// Emit device code for the target simd directive.
3590   static void EmitOMPTargetSimdDeviceFunction(CodeGenModule &CGM,
3591                                               StringRef ParentName,
3592                                               const OMPTargetSimdDirective &S);
3593   /// Emit device code for the target teams distribute parallel for simd
3594   /// directive.
3595   static void EmitOMPTargetTeamsDistributeParallelForSimdDeviceFunction(
3596       CodeGenModule &CGM, StringRef ParentName,
3597       const OMPTargetTeamsDistributeParallelForSimdDirective &S);
3598 
3599   static void EmitOMPTargetTeamsDistributeParallelForDeviceFunction(
3600       CodeGenModule &CGM, StringRef ParentName,
3601       const OMPTargetTeamsDistributeParallelForDirective &S);
3602 
3603   /// Emit the Stmt \p S and return its topmost canonical loop, if any.
3604   /// TODO: The \p Depth paramter is not yet implemented and must be 1. In the
3605   /// future it is meant to be the number of loops expected in the loop nests
3606   /// (usually specified by the "collapse" clause) that are collapsed to a
3607   /// single loop by this function.
3608   llvm::CanonicalLoopInfo *EmitOMPCollapsedCanonicalLoopNest(const Stmt *S,
3609                                                              int Depth);
3610 
3611   /// Emit an OMPCanonicalLoop using the OpenMPIRBuilder.
3612   void EmitOMPCanonicalLoop(const OMPCanonicalLoop *S);
3613 
3614   /// Emit inner loop of the worksharing/simd construct.
3615   ///
3616   /// \param S Directive, for which the inner loop must be emitted.
3617   /// \param RequiresCleanup true, if directive has some associated private
3618   /// variables.
3619   /// \param LoopCond Bollean condition for loop continuation.
3620   /// \param IncExpr Increment expression for loop control variable.
3621   /// \param BodyGen Generator for the inner body of the inner loop.
3622   /// \param PostIncGen Genrator for post-increment code (required for ordered
3623   /// loop directvies).
3624   void EmitOMPInnerLoop(
3625       const OMPExecutableDirective &S, bool RequiresCleanup,
3626       const Expr *LoopCond, const Expr *IncExpr,
3627       const llvm::function_ref<void(CodeGenFunction &)> BodyGen,
3628       const llvm::function_ref<void(CodeGenFunction &)> PostIncGen);
3629 
3630   JumpDest getOMPCancelDestination(OpenMPDirectiveKind Kind);
3631   /// Emit initial code for loop counters of loop-based directives.
3632   void EmitOMPPrivateLoopCounters(const OMPLoopDirective &S,
3633                                   OMPPrivateScope &LoopScope);
3634 
3635   /// Helper for the OpenMP loop directives.
3636   void EmitOMPLoopBody(const OMPLoopDirective &D, JumpDest LoopExit);
3637 
3638   /// Emit code for the worksharing loop-based directive.
3639   /// \return true, if this construct has any lastprivate clause, false -
3640   /// otherwise.
3641   bool EmitOMPWorksharingLoop(const OMPLoopDirective &S, Expr *EUB,
3642                               const CodeGenLoopBoundsTy &CodeGenLoopBounds,
3643                               const CodeGenDispatchBoundsTy &CGDispatchBounds);
3644 
3645   /// Emit code for the distribute loop-based directive.
3646   void EmitOMPDistributeLoop(const OMPLoopDirective &S,
3647                              const CodeGenLoopTy &CodeGenLoop, Expr *IncExpr);
3648 
3649   /// Helpers for the OpenMP loop directives.
3650   void EmitOMPSimdInit(const OMPLoopDirective &D);
3651   void EmitOMPSimdFinal(
3652       const OMPLoopDirective &D,
3653       const llvm::function_ref<llvm::Value *(CodeGenFunction &)> CondGen);
3654 
3655   /// Emits the lvalue for the expression with possibly captured variable.
3656   LValue EmitOMPSharedLValue(const Expr *E);
3657 
3658 private:
3659   /// Helpers for blocks.
3660   llvm::Value *EmitBlockLiteral(const CGBlockInfo &Info);
3661 
3662   /// struct with the values to be passed to the OpenMP loop-related functions
3663   struct OMPLoopArguments {
3664     /// loop lower bound
3665     Address LB = Address::invalid();
3666     /// loop upper bound
3667     Address UB = Address::invalid();
3668     /// loop stride
3669     Address ST = Address::invalid();
3670     /// isLastIteration argument for runtime functions
3671     Address IL = Address::invalid();
3672     /// Chunk value generated by sema
3673     llvm::Value *Chunk = nullptr;
3674     /// EnsureUpperBound
3675     Expr *EUB = nullptr;
3676     /// IncrementExpression
3677     Expr *IncExpr = nullptr;
3678     /// Loop initialization
3679     Expr *Init = nullptr;
3680     /// Loop exit condition
3681     Expr *Cond = nullptr;
3682     /// Update of LB after a whole chunk has been executed
3683     Expr *NextLB = nullptr;
3684     /// Update of UB after a whole chunk has been executed
3685     Expr *NextUB = nullptr;
3686     OMPLoopArguments() = default;
3687     OMPLoopArguments(Address LB, Address UB, Address ST, Address IL,
3688                      llvm::Value *Chunk = nullptr, Expr *EUB = nullptr,
3689                      Expr *IncExpr = nullptr, Expr *Init = nullptr,
3690                      Expr *Cond = nullptr, Expr *NextLB = nullptr,
3691                      Expr *NextUB = nullptr)
3692         : LB(LB), UB(UB), ST(ST), IL(IL), Chunk(Chunk), EUB(EUB),
3693           IncExpr(IncExpr), Init(Init), Cond(Cond), NextLB(NextLB),
3694           NextUB(NextUB) {}
3695   };
3696   void EmitOMPOuterLoop(bool DynamicOrOrdered, bool IsMonotonic,
3697                         const OMPLoopDirective &S, OMPPrivateScope &LoopScope,
3698                         const OMPLoopArguments &LoopArgs,
3699                         const CodeGenLoopTy &CodeGenLoop,
3700                         const CodeGenOrderedTy &CodeGenOrdered);
3701   void EmitOMPForOuterLoop(const OpenMPScheduleTy &ScheduleKind,
3702                            bool IsMonotonic, const OMPLoopDirective &S,
3703                            OMPPrivateScope &LoopScope, bool Ordered,
3704                            const OMPLoopArguments &LoopArgs,
3705                            const CodeGenDispatchBoundsTy &CGDispatchBounds);
3706   void EmitOMPDistributeOuterLoop(OpenMPDistScheduleClauseKind ScheduleKind,
3707                                   const OMPLoopDirective &S,
3708                                   OMPPrivateScope &LoopScope,
3709                                   const OMPLoopArguments &LoopArgs,
3710                                   const CodeGenLoopTy &CodeGenLoopContent);
3711   /// Emit code for sections directive.
3712   void EmitSections(const OMPExecutableDirective &S);
3713 
3714 public:
3715 
3716   //===--------------------------------------------------------------------===//
3717   //                         LValue Expression Emission
3718   //===--------------------------------------------------------------------===//
3719 
3720   /// Create a check that a scalar RValue is non-null.
3721   llvm::Value *EmitNonNullRValueCheck(RValue RV, QualType T);
3722 
3723   /// GetUndefRValue - Get an appropriate 'undef' rvalue for the given type.
3724   RValue GetUndefRValue(QualType Ty);
3725 
3726   /// EmitUnsupportedRValue - Emit a dummy r-value using the type of E
3727   /// and issue an ErrorUnsupported style diagnostic (using the
3728   /// provided Name).
3729   RValue EmitUnsupportedRValue(const Expr *E,
3730                                const char *Name);
3731 
3732   /// EmitUnsupportedLValue - Emit a dummy l-value using the type of E and issue
3733   /// an ErrorUnsupported style diagnostic (using the provided Name).
3734   LValue EmitUnsupportedLValue(const Expr *E,
3735                                const char *Name);
3736 
3737   /// EmitLValue - Emit code to compute a designator that specifies the location
3738   /// of the expression.
3739   ///
3740   /// This can return one of two things: a simple address or a bitfield
3741   /// reference.  In either case, the LLVM Value* in the LValue structure is
3742   /// guaranteed to be an LLVM pointer type.
3743   ///
3744   /// If this returns a bitfield reference, nothing about the pointee type of
3745   /// the LLVM value is known: For example, it may not be a pointer to an
3746   /// integer.
3747   ///
3748   /// If this returns a normal address, and if the lvalue's C type is fixed
3749   /// size, this method guarantees that the returned pointer type will point to
3750   /// an LLVM type of the same size of the lvalue's type.  If the lvalue has a
3751   /// variable length type, this is not possible.
3752   ///
3753   LValue EmitLValue(const Expr *E);
3754 
3755   /// Same as EmitLValue but additionally we generate checking code to
3756   /// guard against undefined behavior.  This is only suitable when we know
3757   /// that the address will be used to access the object.
3758   LValue EmitCheckedLValue(const Expr *E, TypeCheckKind TCK);
3759 
3760   RValue convertTempToRValue(Address addr, QualType type,
3761                              SourceLocation Loc);
3762 
3763   void EmitAtomicInit(Expr *E, LValue lvalue);
3764 
3765   bool LValueIsSuitableForInlineAtomic(LValue Src);
3766 
3767   RValue EmitAtomicLoad(LValue LV, SourceLocation SL,
3768                         AggValueSlot Slot = AggValueSlot::ignored());
3769 
3770   RValue EmitAtomicLoad(LValue lvalue, SourceLocation loc,
3771                         llvm::AtomicOrdering AO, bool IsVolatile = false,
3772                         AggValueSlot slot = AggValueSlot::ignored());
3773 
3774   void EmitAtomicStore(RValue rvalue, LValue lvalue, bool isInit);
3775 
3776   void EmitAtomicStore(RValue rvalue, LValue lvalue, llvm::AtomicOrdering AO,
3777                        bool IsVolatile, bool isInit);
3778 
3779   std::pair<RValue, llvm::Value *> EmitAtomicCompareExchange(
3780       LValue Obj, RValue Expected, RValue Desired, SourceLocation Loc,
3781       llvm::AtomicOrdering Success =
3782           llvm::AtomicOrdering::SequentiallyConsistent,
3783       llvm::AtomicOrdering Failure =
3784           llvm::AtomicOrdering::SequentiallyConsistent,
3785       bool IsWeak = false, AggValueSlot Slot = AggValueSlot::ignored());
3786 
3787   void EmitAtomicUpdate(LValue LVal, llvm::AtomicOrdering AO,
3788                         const llvm::function_ref<RValue(RValue)> &UpdateOp,
3789                         bool IsVolatile);
3790 
3791   /// EmitToMemory - Change a scalar value from its value
3792   /// representation to its in-memory representation.
3793   llvm::Value *EmitToMemory(llvm::Value *Value, QualType Ty);
3794 
3795   /// EmitFromMemory - Change a scalar value from its memory
3796   /// representation to its value representation.
3797   llvm::Value *EmitFromMemory(llvm::Value *Value, QualType Ty);
3798 
3799   /// Check if the scalar \p Value is within the valid range for the given
3800   /// type \p Ty.
3801   ///
3802   /// Returns true if a check is needed (even if the range is unknown).
3803   bool EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
3804                             SourceLocation Loc);
3805 
3806   /// EmitLoadOfScalar - Load a scalar value from an address, taking
3807   /// care to appropriately convert from the memory representation to
3808   /// the LLVM value representation.
3809   llvm::Value *EmitLoadOfScalar(Address Addr, bool Volatile, QualType Ty,
3810                                 SourceLocation Loc,
3811                                 AlignmentSource Source = AlignmentSource::Type,
3812                                 bool isNontemporal = false) {
3813     return EmitLoadOfScalar(Addr, Volatile, Ty, Loc, LValueBaseInfo(Source),
3814                             CGM.getTBAAAccessInfo(Ty), isNontemporal);
3815   }
3816 
3817   llvm::Value *EmitLoadOfScalar(Address Addr, bool Volatile, QualType Ty,
3818                                 SourceLocation Loc, LValueBaseInfo BaseInfo,
3819                                 TBAAAccessInfo TBAAInfo,
3820                                 bool isNontemporal = false);
3821 
3822   /// EmitLoadOfScalar - Load a scalar value from an address, taking
3823   /// care to appropriately convert from the memory representation to
3824   /// the LLVM value representation.  The l-value must be a simple
3825   /// l-value.
3826   llvm::Value *EmitLoadOfScalar(LValue lvalue, SourceLocation Loc);
3827 
3828   /// EmitStoreOfScalar - Store a scalar value to an address, taking
3829   /// care to appropriately convert from the memory representation to
3830   /// the LLVM value representation.
3831   void EmitStoreOfScalar(llvm::Value *Value, Address Addr,
3832                          bool Volatile, QualType Ty,
3833                          AlignmentSource Source = AlignmentSource::Type,
3834                          bool isInit = false, bool isNontemporal = false) {
3835     EmitStoreOfScalar(Value, Addr, Volatile, Ty, LValueBaseInfo(Source),
3836                       CGM.getTBAAAccessInfo(Ty), isInit, isNontemporal);
3837   }
3838 
3839   void EmitStoreOfScalar(llvm::Value *Value, Address Addr,
3840                          bool Volatile, QualType Ty,
3841                          LValueBaseInfo BaseInfo, TBAAAccessInfo TBAAInfo,
3842                          bool isInit = false, bool isNontemporal = false);
3843 
3844   /// EmitStoreOfScalar - Store a scalar value to an address, taking
3845   /// care to appropriately convert from the memory representation to
3846   /// the LLVM value representation.  The l-value must be a simple
3847   /// l-value.  The isInit flag indicates whether this is an initialization.
3848   /// If so, atomic qualifiers are ignored and the store is always non-atomic.
3849   void EmitStoreOfScalar(llvm::Value *value, LValue lvalue, bool isInit=false);
3850 
3851   /// EmitLoadOfLValue - Given an expression that represents a value lvalue,
3852   /// this method emits the address of the lvalue, then loads the result as an
3853   /// rvalue, returning the rvalue.
3854   RValue EmitLoadOfLValue(LValue V, SourceLocation Loc);
3855   RValue EmitLoadOfExtVectorElementLValue(LValue V);
3856   RValue EmitLoadOfBitfieldLValue(LValue LV, SourceLocation Loc);
3857   RValue EmitLoadOfGlobalRegLValue(LValue LV);
3858 
3859   /// EmitStoreThroughLValue - Store the specified rvalue into the specified
3860   /// lvalue, where both are guaranteed to the have the same type, and that type
3861   /// is 'Ty'.
3862   void EmitStoreThroughLValue(RValue Src, LValue Dst, bool isInit = false);
3863   void EmitStoreThroughExtVectorComponentLValue(RValue Src, LValue Dst);
3864   void EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst);
3865 
3866   /// EmitStoreThroughBitfieldLValue - Store Src into Dst with same constraints
3867   /// as EmitStoreThroughLValue.
3868   ///
3869   /// \param Result [out] - If non-null, this will be set to a Value* for the
3870   /// bit-field contents after the store, appropriate for use as the result of
3871   /// an assignment to the bit-field.
3872   void EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
3873                                       llvm::Value **Result=nullptr);
3874 
3875   /// Emit an l-value for an assignment (simple or compound) of complex type.
3876   LValue EmitComplexAssignmentLValue(const BinaryOperator *E);
3877   LValue EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E);
3878   LValue EmitScalarCompoundAssignWithComplex(const CompoundAssignOperator *E,
3879                                              llvm::Value *&Result);
3880 
3881   // Note: only available for agg return types
3882   LValue EmitBinaryOperatorLValue(const BinaryOperator *E);
3883   LValue EmitCompoundAssignmentLValue(const CompoundAssignOperator *E);
3884   // Note: only available for agg return types
3885   LValue EmitCallExprLValue(const CallExpr *E);
3886   // Note: only available for agg return types
3887   LValue EmitVAArgExprLValue(const VAArgExpr *E);
3888   LValue EmitDeclRefLValue(const DeclRefExpr *E);
3889   LValue EmitStringLiteralLValue(const StringLiteral *E);
3890   LValue EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E);
3891   LValue EmitPredefinedLValue(const PredefinedExpr *E);
3892   LValue EmitUnaryOpLValue(const UnaryOperator *E);
3893   LValue EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
3894                                 bool Accessed = false);
3895   LValue EmitMatrixSubscriptExpr(const MatrixSubscriptExpr *E);
3896   LValue EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
3897                                  bool IsLowerBound = true);
3898   LValue EmitExtVectorElementExpr(const ExtVectorElementExpr *E);
3899   LValue EmitMemberExpr(const MemberExpr *E);
3900   LValue EmitObjCIsaExpr(const ObjCIsaExpr *E);
3901   LValue EmitCompoundLiteralLValue(const CompoundLiteralExpr *E);
3902   LValue EmitInitListLValue(const InitListExpr *E);
3903   LValue EmitConditionalOperatorLValue(const AbstractConditionalOperator *E);
3904   LValue EmitCastLValue(const CastExpr *E);
3905   LValue EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E);
3906   LValue EmitOpaqueValueLValue(const OpaqueValueExpr *e);
3907 
3908   Address EmitExtVectorElementLValue(LValue V);
3909 
3910   RValue EmitRValueForField(LValue LV, const FieldDecl *FD, SourceLocation Loc);
3911 
3912   Address EmitArrayToPointerDecay(const Expr *Array,
3913                                   LValueBaseInfo *BaseInfo = nullptr,
3914                                   TBAAAccessInfo *TBAAInfo = nullptr);
3915 
3916   class ConstantEmission {
3917     llvm::PointerIntPair<llvm::Constant*, 1, bool> ValueAndIsReference;
3918     ConstantEmission(llvm::Constant *C, bool isReference)
3919       : ValueAndIsReference(C, isReference) {}
3920   public:
3921     ConstantEmission() {}
3922     static ConstantEmission forReference(llvm::Constant *C) {
3923       return ConstantEmission(C, true);
3924     }
3925     static ConstantEmission forValue(llvm::Constant *C) {
3926       return ConstantEmission(C, false);
3927     }
3928 
3929     explicit operator bool() const {
3930       return ValueAndIsReference.getOpaqueValue() != nullptr;
3931     }
3932 
3933     bool isReference() const { return ValueAndIsReference.getInt(); }
3934     LValue getReferenceLValue(CodeGenFunction &CGF, Expr *refExpr) const {
3935       assert(isReference());
3936       return CGF.MakeNaturalAlignAddrLValue(ValueAndIsReference.getPointer(),
3937                                             refExpr->getType());
3938     }
3939 
3940     llvm::Constant *getValue() const {
3941       assert(!isReference());
3942       return ValueAndIsReference.getPointer();
3943     }
3944   };
3945 
3946   ConstantEmission tryEmitAsConstant(DeclRefExpr *refExpr);
3947   ConstantEmission tryEmitAsConstant(const MemberExpr *ME);
3948   llvm::Value *emitScalarConstant(const ConstantEmission &Constant, Expr *E);
3949 
3950   RValue EmitPseudoObjectRValue(const PseudoObjectExpr *e,
3951                                 AggValueSlot slot = AggValueSlot::ignored());
3952   LValue EmitPseudoObjectLValue(const PseudoObjectExpr *e);
3953 
3954   llvm::Value *EmitIvarOffset(const ObjCInterfaceDecl *Interface,
3955                               const ObjCIvarDecl *Ivar);
3956   LValue EmitLValueForField(LValue Base, const FieldDecl* Field);
3957   LValue EmitLValueForLambdaField(const FieldDecl *Field);
3958 
3959   /// EmitLValueForFieldInitialization - Like EmitLValueForField, except that
3960   /// if the Field is a reference, this will return the address of the reference
3961   /// and not the address of the value stored in the reference.
3962   LValue EmitLValueForFieldInitialization(LValue Base,
3963                                           const FieldDecl* Field);
3964 
3965   LValue EmitLValueForIvar(QualType ObjectTy,
3966                            llvm::Value* Base, const ObjCIvarDecl *Ivar,
3967                            unsigned CVRQualifiers);
3968 
3969   LValue EmitCXXConstructLValue(const CXXConstructExpr *E);
3970   LValue EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E);
3971   LValue EmitCXXTypeidLValue(const CXXTypeidExpr *E);
3972   LValue EmitCXXUuidofLValue(const CXXUuidofExpr *E);
3973 
3974   LValue EmitObjCMessageExprLValue(const ObjCMessageExpr *E);
3975   LValue EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E);
3976   LValue EmitStmtExprLValue(const StmtExpr *E);
3977   LValue EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E);
3978   LValue EmitObjCSelectorLValue(const ObjCSelectorExpr *E);
3979   void   EmitDeclRefExprDbgValue(const DeclRefExpr *E, const APValue &Init);
3980 
3981   //===--------------------------------------------------------------------===//
3982   //                         Scalar Expression Emission
3983   //===--------------------------------------------------------------------===//
3984 
3985   /// EmitCall - Generate a call of the given function, expecting the given
3986   /// result type, and using the given argument list which specifies both the
3987   /// LLVM arguments and the types they were derived from.
3988   RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee,
3989                   ReturnValueSlot ReturnValue, const CallArgList &Args,
3990                   llvm::CallBase **callOrInvoke, bool IsMustTail,
3991                   SourceLocation Loc);
3992   RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee,
3993                   ReturnValueSlot ReturnValue, const CallArgList &Args,
3994                   llvm::CallBase **callOrInvoke = nullptr,
3995                   bool IsMustTail = false) {
3996     return EmitCall(CallInfo, Callee, ReturnValue, Args, callOrInvoke,
3997                     IsMustTail, SourceLocation());
3998   }
3999   RValue EmitCall(QualType FnType, const CGCallee &Callee, const CallExpr *E,
4000                   ReturnValueSlot ReturnValue, llvm::Value *Chain = nullptr);
4001   RValue EmitCallExpr(const CallExpr *E,
4002                       ReturnValueSlot ReturnValue = ReturnValueSlot());
4003   RValue EmitSimpleCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue);
4004   CGCallee EmitCallee(const Expr *E);
4005 
4006   void checkTargetFeatures(const CallExpr *E, const FunctionDecl *TargetDecl);
4007   void checkTargetFeatures(SourceLocation Loc, const FunctionDecl *TargetDecl);
4008 
4009   llvm::CallInst *EmitRuntimeCall(llvm::FunctionCallee callee,
4010                                   const Twine &name = "");
4011   llvm::CallInst *EmitRuntimeCall(llvm::FunctionCallee callee,
4012                                   ArrayRef<llvm::Value *> args,
4013                                   const Twine &name = "");
4014   llvm::CallInst *EmitNounwindRuntimeCall(llvm::FunctionCallee callee,
4015                                           const Twine &name = "");
4016   llvm::CallInst *EmitNounwindRuntimeCall(llvm::FunctionCallee callee,
4017                                           ArrayRef<llvm::Value *> args,
4018                                           const Twine &name = "");
4019 
4020   SmallVector<llvm::OperandBundleDef, 1>
4021   getBundlesForFunclet(llvm::Value *Callee);
4022 
4023   llvm::CallBase *EmitCallOrInvoke(llvm::FunctionCallee Callee,
4024                                    ArrayRef<llvm::Value *> Args,
4025                                    const Twine &Name = "");
4026   llvm::CallBase *EmitRuntimeCallOrInvoke(llvm::FunctionCallee callee,
4027                                           ArrayRef<llvm::Value *> args,
4028                                           const Twine &name = "");
4029   llvm::CallBase *EmitRuntimeCallOrInvoke(llvm::FunctionCallee callee,
4030                                           const Twine &name = "");
4031   void EmitNoreturnRuntimeCallOrInvoke(llvm::FunctionCallee callee,
4032                                        ArrayRef<llvm::Value *> args);
4033 
4034   CGCallee BuildAppleKextVirtualCall(const CXXMethodDecl *MD,
4035                                      NestedNameSpecifier *Qual,
4036                                      llvm::Type *Ty);
4037 
4038   CGCallee BuildAppleKextVirtualDestructorCall(const CXXDestructorDecl *DD,
4039                                                CXXDtorType Type,
4040                                                const CXXRecordDecl *RD);
4041 
4042   // Return the copy constructor name with the prefix "__copy_constructor_"
4043   // removed.
4044   static std::string getNonTrivialCopyConstructorStr(QualType QT,
4045                                                      CharUnits Alignment,
4046                                                      bool IsVolatile,
4047                                                      ASTContext &Ctx);
4048 
4049   // Return the destructor name with the prefix "__destructor_" removed.
4050   static std::string getNonTrivialDestructorStr(QualType QT,
4051                                                 CharUnits Alignment,
4052                                                 bool IsVolatile,
4053                                                 ASTContext &Ctx);
4054 
4055   // These functions emit calls to the special functions of non-trivial C
4056   // structs.
4057   void defaultInitNonTrivialCStructVar(LValue Dst);
4058   void callCStructDefaultConstructor(LValue Dst);
4059   void callCStructDestructor(LValue Dst);
4060   void callCStructCopyConstructor(LValue Dst, LValue Src);
4061   void callCStructMoveConstructor(LValue Dst, LValue Src);
4062   void callCStructCopyAssignmentOperator(LValue Dst, LValue Src);
4063   void callCStructMoveAssignmentOperator(LValue Dst, LValue Src);
4064 
4065   RValue
4066   EmitCXXMemberOrOperatorCall(const CXXMethodDecl *Method,
4067                               const CGCallee &Callee,
4068                               ReturnValueSlot ReturnValue, llvm::Value *This,
4069                               llvm::Value *ImplicitParam,
4070                               QualType ImplicitParamTy, const CallExpr *E,
4071                               CallArgList *RtlArgs);
4072   RValue EmitCXXDestructorCall(GlobalDecl Dtor, const CGCallee &Callee,
4073                                llvm::Value *This, QualType ThisTy,
4074                                llvm::Value *ImplicitParam,
4075                                QualType ImplicitParamTy, const CallExpr *E);
4076   RValue EmitCXXMemberCallExpr(const CXXMemberCallExpr *E,
4077                                ReturnValueSlot ReturnValue);
4078   RValue EmitCXXMemberOrOperatorMemberCallExpr(const CallExpr *CE,
4079                                                const CXXMethodDecl *MD,
4080                                                ReturnValueSlot ReturnValue,
4081                                                bool HasQualifier,
4082                                                NestedNameSpecifier *Qualifier,
4083                                                bool IsArrow, const Expr *Base);
4084   // Compute the object pointer.
4085   Address EmitCXXMemberDataPointerAddress(const Expr *E, Address base,
4086                                           llvm::Value *memberPtr,
4087                                           const MemberPointerType *memberPtrType,
4088                                           LValueBaseInfo *BaseInfo = nullptr,
4089                                           TBAAAccessInfo *TBAAInfo = nullptr);
4090   RValue EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
4091                                       ReturnValueSlot ReturnValue);
4092 
4093   RValue EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E,
4094                                        const CXXMethodDecl *MD,
4095                                        ReturnValueSlot ReturnValue);
4096   RValue EmitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E);
4097 
4098   RValue EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E,
4099                                 ReturnValueSlot ReturnValue);
4100 
4101   RValue EmitNVPTXDevicePrintfCallExpr(const CallExpr *E);
4102   RValue EmitAMDGPUDevicePrintfCallExpr(const CallExpr *E);
4103   RValue EmitOpenMPDevicePrintfCallExpr(const CallExpr *E);
4104 
4105   RValue EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
4106                          const CallExpr *E, ReturnValueSlot ReturnValue);
4107 
4108   RValue emitRotate(const CallExpr *E, bool IsRotateRight);
4109 
4110   /// Emit IR for __builtin_os_log_format.
4111   RValue emitBuiltinOSLogFormat(const CallExpr &E);
4112 
4113   /// Emit IR for __builtin_is_aligned.
4114   RValue EmitBuiltinIsAligned(const CallExpr *E);
4115   /// Emit IR for __builtin_align_up/__builtin_align_down.
4116   RValue EmitBuiltinAlignTo(const CallExpr *E, bool AlignUp);
4117 
4118   llvm::Function *generateBuiltinOSLogHelperFunction(
4119       const analyze_os_log::OSLogBufferLayout &Layout,
4120       CharUnits BufferAlignment);
4121 
4122   RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue);
4123 
4124   /// EmitTargetBuiltinExpr - Emit the given builtin call. Returns 0 if the call
4125   /// is unhandled by the current target.
4126   llvm::Value *EmitTargetBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
4127                                      ReturnValueSlot ReturnValue);
4128 
4129   llvm::Value *EmitAArch64CompareBuiltinExpr(llvm::Value *Op, llvm::Type *Ty,
4130                                              const llvm::CmpInst::Predicate Fp,
4131                                              const llvm::CmpInst::Predicate Ip,
4132                                              const llvm::Twine &Name = "");
4133   llvm::Value *EmitARMBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
4134                                   ReturnValueSlot ReturnValue,
4135                                   llvm::Triple::ArchType Arch);
4136   llvm::Value *EmitARMMVEBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
4137                                      ReturnValueSlot ReturnValue,
4138                                      llvm::Triple::ArchType Arch);
4139   llvm::Value *EmitARMCDEBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
4140                                      ReturnValueSlot ReturnValue,
4141                                      llvm::Triple::ArchType Arch);
4142   llvm::Value *EmitCMSEClearRecord(llvm::Value *V, llvm::IntegerType *ITy,
4143                                    QualType RTy);
4144   llvm::Value *EmitCMSEClearRecord(llvm::Value *V, llvm::ArrayType *ATy,
4145                                    QualType RTy);
4146 
4147   llvm::Value *EmitCommonNeonBuiltinExpr(unsigned BuiltinID,
4148                                          unsigned LLVMIntrinsic,
4149                                          unsigned AltLLVMIntrinsic,
4150                                          const char *NameHint,
4151                                          unsigned Modifier,
4152                                          const CallExpr *E,
4153                                          SmallVectorImpl<llvm::Value *> &Ops,
4154                                          Address PtrOp0, Address PtrOp1,
4155                                          llvm::Triple::ArchType Arch);
4156 
4157   llvm::Function *LookupNeonLLVMIntrinsic(unsigned IntrinsicID,
4158                                           unsigned Modifier, llvm::Type *ArgTy,
4159                                           const CallExpr *E);
4160   llvm::Value *EmitNeonCall(llvm::Function *F,
4161                             SmallVectorImpl<llvm::Value*> &O,
4162                             const char *name,
4163                             unsigned shift = 0, bool rightshift = false);
4164   llvm::Value *EmitNeonSplat(llvm::Value *V, llvm::Constant *Idx,
4165                              const llvm::ElementCount &Count);
4166   llvm::Value *EmitNeonSplat(llvm::Value *V, llvm::Constant *Idx);
4167   llvm::Value *EmitNeonShiftVector(llvm::Value *V, llvm::Type *Ty,
4168                                    bool negateForRightShift);
4169   llvm::Value *EmitNeonRShiftImm(llvm::Value *Vec, llvm::Value *Amt,
4170                                  llvm::Type *Ty, bool usgn, const char *name);
4171   llvm::Value *vectorWrapScalar16(llvm::Value *Op);
4172   /// SVEBuiltinMemEltTy - Returns the memory element type for this memory
4173   /// access builtin.  Only required if it can't be inferred from the base
4174   /// pointer operand.
4175   llvm::Type *SVEBuiltinMemEltTy(const SVETypeFlags &TypeFlags);
4176 
4177   SmallVector<llvm::Type *, 2>
4178   getSVEOverloadTypes(const SVETypeFlags &TypeFlags, llvm::Type *ReturnType,
4179                       ArrayRef<llvm::Value *> Ops);
4180   llvm::Type *getEltType(const SVETypeFlags &TypeFlags);
4181   llvm::ScalableVectorType *getSVEType(const SVETypeFlags &TypeFlags);
4182   llvm::ScalableVectorType *getSVEPredType(const SVETypeFlags &TypeFlags);
4183   llvm::Value *EmitSVEAllTruePred(const SVETypeFlags &TypeFlags);
4184   llvm::Value *EmitSVEDupX(llvm::Value *Scalar);
4185   llvm::Value *EmitSVEDupX(llvm::Value *Scalar, llvm::Type *Ty);
4186   llvm::Value *EmitSVEReinterpret(llvm::Value *Val, llvm::Type *Ty);
4187   llvm::Value *EmitSVEPMull(const SVETypeFlags &TypeFlags,
4188                             llvm::SmallVectorImpl<llvm::Value *> &Ops,
4189                             unsigned BuiltinID);
4190   llvm::Value *EmitSVEMovl(const SVETypeFlags &TypeFlags,
4191                            llvm::ArrayRef<llvm::Value *> Ops,
4192                            unsigned BuiltinID);
4193   llvm::Value *EmitSVEPredicateCast(llvm::Value *Pred,
4194                                     llvm::ScalableVectorType *VTy);
4195   llvm::Value *EmitSVEGatherLoad(const SVETypeFlags &TypeFlags,
4196                                  llvm::SmallVectorImpl<llvm::Value *> &Ops,
4197                                  unsigned IntID);
4198   llvm::Value *EmitSVEScatterStore(const SVETypeFlags &TypeFlags,
4199                                    llvm::SmallVectorImpl<llvm::Value *> &Ops,
4200                                    unsigned IntID);
4201   llvm::Value *EmitSVEMaskedLoad(const CallExpr *, llvm::Type *ReturnTy,
4202                                  SmallVectorImpl<llvm::Value *> &Ops,
4203                                  unsigned BuiltinID, bool IsZExtReturn);
4204   llvm::Value *EmitSVEMaskedStore(const CallExpr *,
4205                                   SmallVectorImpl<llvm::Value *> &Ops,
4206                                   unsigned BuiltinID);
4207   llvm::Value *EmitSVEPrefetchLoad(const SVETypeFlags &TypeFlags,
4208                                    SmallVectorImpl<llvm::Value *> &Ops,
4209                                    unsigned BuiltinID);
4210   llvm::Value *EmitSVEGatherPrefetch(const SVETypeFlags &TypeFlags,
4211                                      SmallVectorImpl<llvm::Value *> &Ops,
4212                                      unsigned IntID);
4213   llvm::Value *EmitSVEStructLoad(const SVETypeFlags &TypeFlags,
4214                                  SmallVectorImpl<llvm::Value *> &Ops,
4215                                  unsigned IntID);
4216   llvm::Value *EmitSVEStructStore(const SVETypeFlags &TypeFlags,
4217                                   SmallVectorImpl<llvm::Value *> &Ops,
4218                                   unsigned IntID);
4219   llvm::Value *EmitAArch64SVEBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
4220 
4221   llvm::Value *EmitAArch64BuiltinExpr(unsigned BuiltinID, const CallExpr *E,
4222                                       llvm::Triple::ArchType Arch);
4223   llvm::Value *EmitBPFBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
4224 
4225   llvm::Value *BuildVector(ArrayRef<llvm::Value*> Ops);
4226   llvm::Value *EmitX86BuiltinExpr(unsigned BuiltinID, const CallExpr *E);
4227   llvm::Value *EmitPPCBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
4228   llvm::Value *EmitAMDGPUBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
4229   llvm::Value *EmitSystemZBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
4230   llvm::Value *EmitNVPTXBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
4231   llvm::Value *EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
4232                                           const CallExpr *E);
4233   llvm::Value *EmitHexagonBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
4234   llvm::Value *EmitRISCVBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
4235                                     ReturnValueSlot ReturnValue);
4236   bool ProcessOrderScopeAMDGCN(llvm::Value *Order, llvm::Value *Scope,
4237                                llvm::AtomicOrdering &AO,
4238                                llvm::SyncScope::ID &SSID);
4239 
4240   enum class MSVCIntrin;
4241   llvm::Value *EmitMSVCBuiltinExpr(MSVCIntrin BuiltinID, const CallExpr *E);
4242 
4243   llvm::Value *EmitBuiltinAvailable(const VersionTuple &Version);
4244 
4245   llvm::Value *EmitObjCProtocolExpr(const ObjCProtocolExpr *E);
4246   llvm::Value *EmitObjCStringLiteral(const ObjCStringLiteral *E);
4247   llvm::Value *EmitObjCBoxedExpr(const ObjCBoxedExpr *E);
4248   llvm::Value *EmitObjCArrayLiteral(const ObjCArrayLiteral *E);
4249   llvm::Value *EmitObjCDictionaryLiteral(const ObjCDictionaryLiteral *E);
4250   llvm::Value *EmitObjCCollectionLiteral(const Expr *E,
4251                                 const ObjCMethodDecl *MethodWithObjects);
4252   llvm::Value *EmitObjCSelectorExpr(const ObjCSelectorExpr *E);
4253   RValue EmitObjCMessageExpr(const ObjCMessageExpr *E,
4254                              ReturnValueSlot Return = ReturnValueSlot());
4255 
4256   /// Retrieves the default cleanup kind for an ARC cleanup.
4257   /// Except under -fobjc-arc-eh, ARC cleanups are normal-only.
4258   CleanupKind getARCCleanupKind() {
4259     return CGM.getCodeGenOpts().ObjCAutoRefCountExceptions
4260              ? NormalAndEHCleanup : NormalCleanup;
4261   }
4262 
4263   // ARC primitives.
4264   void EmitARCInitWeak(Address addr, llvm::Value *value);
4265   void EmitARCDestroyWeak(Address addr);
4266   llvm::Value *EmitARCLoadWeak(Address addr);
4267   llvm::Value *EmitARCLoadWeakRetained(Address addr);
4268   llvm::Value *EmitARCStoreWeak(Address addr, llvm::Value *value, bool ignored);
4269   void emitARCCopyAssignWeak(QualType Ty, Address DstAddr, Address SrcAddr);
4270   void emitARCMoveAssignWeak(QualType Ty, Address DstAddr, Address SrcAddr);
4271   void EmitARCCopyWeak(Address dst, Address src);
4272   void EmitARCMoveWeak(Address dst, Address src);
4273   llvm::Value *EmitARCRetainAutorelease(QualType type, llvm::Value *value);
4274   llvm::Value *EmitARCRetainAutoreleaseNonBlock(llvm::Value *value);
4275   llvm::Value *EmitARCStoreStrong(LValue lvalue, llvm::Value *value,
4276                                   bool resultIgnored);
4277   llvm::Value *EmitARCStoreStrongCall(Address addr, llvm::Value *value,
4278                                       bool resultIgnored);
4279   llvm::Value *EmitARCRetain(QualType type, llvm::Value *value);
4280   llvm::Value *EmitARCRetainNonBlock(llvm::Value *value);
4281   llvm::Value *EmitARCRetainBlock(llvm::Value *value, bool mandatory);
4282   void EmitARCDestroyStrong(Address addr, ARCPreciseLifetime_t precise);
4283   void EmitARCRelease(llvm::Value *value, ARCPreciseLifetime_t precise);
4284   llvm::Value *EmitARCAutorelease(llvm::Value *value);
4285   llvm::Value *EmitARCAutoreleaseReturnValue(llvm::Value *value);
4286   llvm::Value *EmitARCRetainAutoreleaseReturnValue(llvm::Value *value);
4287   llvm::Value *EmitARCRetainAutoreleasedReturnValue(llvm::Value *value);
4288   llvm::Value *EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value *value);
4289 
4290   llvm::Value *EmitObjCAutorelease(llvm::Value *value, llvm::Type *returnType);
4291   llvm::Value *EmitObjCRetainNonBlock(llvm::Value *value,
4292                                       llvm::Type *returnType);
4293   void EmitObjCRelease(llvm::Value *value, ARCPreciseLifetime_t precise);
4294 
4295   std::pair<LValue,llvm::Value*>
4296   EmitARCStoreAutoreleasing(const BinaryOperator *e);
4297   std::pair<LValue,llvm::Value*>
4298   EmitARCStoreStrong(const BinaryOperator *e, bool ignored);
4299   std::pair<LValue,llvm::Value*>
4300   EmitARCStoreUnsafeUnretained(const BinaryOperator *e, bool ignored);
4301 
4302   llvm::Value *EmitObjCAlloc(llvm::Value *value,
4303                              llvm::Type *returnType);
4304   llvm::Value *EmitObjCAllocWithZone(llvm::Value *value,
4305                                      llvm::Type *returnType);
4306   llvm::Value *EmitObjCAllocInit(llvm::Value *value, llvm::Type *resultType);
4307 
4308   llvm::Value *EmitObjCThrowOperand(const Expr *expr);
4309   llvm::Value *EmitObjCConsumeObject(QualType T, llvm::Value *Ptr);
4310   llvm::Value *EmitObjCExtendObjectLifetime(QualType T, llvm::Value *Ptr);
4311 
4312   llvm::Value *EmitARCExtendBlockObject(const Expr *expr);
4313   llvm::Value *EmitARCReclaimReturnedObject(const Expr *e,
4314                                             bool allowUnsafeClaim);
4315   llvm::Value *EmitARCRetainScalarExpr(const Expr *expr);
4316   llvm::Value *EmitARCRetainAutoreleaseScalarExpr(const Expr *expr);
4317   llvm::Value *EmitARCUnsafeUnretainedScalarExpr(const Expr *expr);
4318 
4319   void EmitARCIntrinsicUse(ArrayRef<llvm::Value*> values);
4320 
4321   void EmitARCNoopIntrinsicUse(ArrayRef<llvm::Value *> values);
4322 
4323   static Destroyer destroyARCStrongImprecise;
4324   static Destroyer destroyARCStrongPrecise;
4325   static Destroyer destroyARCWeak;
4326   static Destroyer emitARCIntrinsicUse;
4327   static Destroyer destroyNonTrivialCStruct;
4328 
4329   void EmitObjCAutoreleasePoolPop(llvm::Value *Ptr);
4330   llvm::Value *EmitObjCAutoreleasePoolPush();
4331   llvm::Value *EmitObjCMRRAutoreleasePoolPush();
4332   void EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr);
4333   void EmitObjCMRRAutoreleasePoolPop(llvm::Value *Ptr);
4334 
4335   /// Emits a reference binding to the passed in expression.
4336   RValue EmitReferenceBindingToExpr(const Expr *E);
4337 
4338   //===--------------------------------------------------------------------===//
4339   //                           Expression Emission
4340   //===--------------------------------------------------------------------===//
4341 
4342   // Expressions are broken into three classes: scalar, complex, aggregate.
4343 
4344   /// EmitScalarExpr - Emit the computation of the specified expression of LLVM
4345   /// scalar type, returning the result.
4346   llvm::Value *EmitScalarExpr(const Expr *E , bool IgnoreResultAssign = false);
4347 
4348   /// Emit a conversion from the specified type to the specified destination
4349   /// type, both of which are LLVM scalar types.
4350   llvm::Value *EmitScalarConversion(llvm::Value *Src, QualType SrcTy,
4351                                     QualType DstTy, SourceLocation Loc);
4352 
4353   /// Emit a conversion from the specified complex type to the specified
4354   /// destination type, where the destination type is an LLVM scalar type.
4355   llvm::Value *EmitComplexToScalarConversion(ComplexPairTy Src, QualType SrcTy,
4356                                              QualType DstTy,
4357                                              SourceLocation Loc);
4358 
4359   /// EmitAggExpr - Emit the computation of the specified expression
4360   /// of aggregate type.  The result is computed into the given slot,
4361   /// which may be null to indicate that the value is not needed.
4362   void EmitAggExpr(const Expr *E, AggValueSlot AS);
4363 
4364   /// EmitAggExprToLValue - Emit the computation of the specified expression of
4365   /// aggregate type into a temporary LValue.
4366   LValue EmitAggExprToLValue(const Expr *E);
4367 
4368   /// Build all the stores needed to initialize an aggregate at Dest with the
4369   /// value Val.
4370   void EmitAggregateStore(llvm::Value *Val, Address Dest, bool DestIsVolatile);
4371 
4372   /// EmitExtendGCLifetime - Given a pointer to an Objective-C object,
4373   /// make sure it survives garbage collection until this point.
4374   void EmitExtendGCLifetime(llvm::Value *object);
4375 
4376   /// EmitComplexExpr - Emit the computation of the specified expression of
4377   /// complex type, returning the result.
4378   ComplexPairTy EmitComplexExpr(const Expr *E,
4379                                 bool IgnoreReal = false,
4380                                 bool IgnoreImag = false);
4381 
4382   /// EmitComplexExprIntoLValue - Emit the given expression of complex
4383   /// type and place its result into the specified l-value.
4384   void EmitComplexExprIntoLValue(const Expr *E, LValue dest, bool isInit);
4385 
4386   /// EmitStoreOfComplex - Store a complex number into the specified l-value.
4387   void EmitStoreOfComplex(ComplexPairTy V, LValue dest, bool isInit);
4388 
4389   /// EmitLoadOfComplex - Load a complex number from the specified l-value.
4390   ComplexPairTy EmitLoadOfComplex(LValue src, SourceLocation loc);
4391 
4392   Address emitAddrOfRealComponent(Address complex, QualType complexType);
4393   Address emitAddrOfImagComponent(Address complex, QualType complexType);
4394 
4395   /// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
4396   /// global variable that has already been created for it.  If the initializer
4397   /// has a different type than GV does, this may free GV and return a different
4398   /// one.  Otherwise it just returns GV.
4399   llvm::GlobalVariable *
4400   AddInitializerToStaticVarDecl(const VarDecl &D,
4401                                 llvm::GlobalVariable *GV);
4402 
4403   // Emit an @llvm.invariant.start call for the given memory region.
4404   void EmitInvariantStart(llvm::Constant *Addr, CharUnits Size);
4405 
4406   /// EmitCXXGlobalVarDeclInit - Create the initializer for a C++
4407   /// variable with global storage.
4408   void EmitCXXGlobalVarDeclInit(const VarDecl &D, llvm::Constant *DeclPtr,
4409                                 bool PerformInit);
4410 
4411   llvm::Function *createAtExitStub(const VarDecl &VD, llvm::FunctionCallee Dtor,
4412                                    llvm::Constant *Addr);
4413 
4414   llvm::Function *createTLSAtExitStub(const VarDecl &VD,
4415                                       llvm::FunctionCallee Dtor,
4416                                       llvm::Constant *Addr,
4417                                       llvm::FunctionCallee &AtExit);
4418 
4419   /// Call atexit() with a function that passes the given argument to
4420   /// the given function.
4421   void registerGlobalDtorWithAtExit(const VarDecl &D, llvm::FunctionCallee fn,
4422                                     llvm::Constant *addr);
4423 
4424   /// Call atexit() with function dtorStub.
4425   void registerGlobalDtorWithAtExit(llvm::Constant *dtorStub);
4426 
4427   /// Call unatexit() with function dtorStub.
4428   llvm::Value *unregisterGlobalDtorWithUnAtExit(llvm::Constant *dtorStub);
4429 
4430   /// Emit code in this function to perform a guarded variable
4431   /// initialization.  Guarded initializations are used when it's not
4432   /// possible to prove that an initialization will be done exactly
4433   /// once, e.g. with a static local variable or a static data member
4434   /// of a class template.
4435   void EmitCXXGuardedInit(const VarDecl &D, llvm::GlobalVariable *DeclPtr,
4436                           bool PerformInit);
4437 
4438   enum class GuardKind { VariableGuard, TlsGuard };
4439 
4440   /// Emit a branch to select whether or not to perform guarded initialization.
4441   void EmitCXXGuardedInitBranch(llvm::Value *NeedsInit,
4442                                 llvm::BasicBlock *InitBlock,
4443                                 llvm::BasicBlock *NoInitBlock,
4444                                 GuardKind Kind, const VarDecl *D);
4445 
4446   /// GenerateCXXGlobalInitFunc - Generates code for initializing global
4447   /// variables.
4448   void
4449   GenerateCXXGlobalInitFunc(llvm::Function *Fn,
4450                             ArrayRef<llvm::Function *> CXXThreadLocals,
4451                             ConstantAddress Guard = ConstantAddress::invalid());
4452 
4453   /// GenerateCXXGlobalCleanUpFunc - Generates code for cleaning up global
4454   /// variables.
4455   void GenerateCXXGlobalCleanUpFunc(
4456       llvm::Function *Fn,
4457       ArrayRef<std::tuple<llvm::FunctionType *, llvm::WeakTrackingVH,
4458                           llvm::Constant *>>
4459           DtorsOrStermFinalizers);
4460 
4461   void GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn,
4462                                         const VarDecl *D,
4463                                         llvm::GlobalVariable *Addr,
4464                                         bool PerformInit);
4465 
4466   void EmitCXXConstructExpr(const CXXConstructExpr *E, AggValueSlot Dest);
4467 
4468   void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp);
4469 
4470   void EmitCXXThrowExpr(const CXXThrowExpr *E, bool KeepInsertionPoint = true);
4471 
4472   RValue EmitAtomicExpr(AtomicExpr *E);
4473 
4474   //===--------------------------------------------------------------------===//
4475   //                         Annotations Emission
4476   //===--------------------------------------------------------------------===//
4477 
4478   /// Emit an annotation call (intrinsic).
4479   llvm::Value *EmitAnnotationCall(llvm::Function *AnnotationFn,
4480                                   llvm::Value *AnnotatedVal,
4481                                   StringRef AnnotationStr,
4482                                   SourceLocation Location,
4483                                   const AnnotateAttr *Attr);
4484 
4485   /// Emit local annotations for the local variable V, declared by D.
4486   void EmitVarAnnotations(const VarDecl *D, llvm::Value *V);
4487 
4488   /// Emit field annotations for the given field & value. Returns the
4489   /// annotation result.
4490   Address EmitFieldAnnotations(const FieldDecl *D, Address V);
4491 
4492   //===--------------------------------------------------------------------===//
4493   //                             Internal Helpers
4494   //===--------------------------------------------------------------------===//
4495 
4496   /// ContainsLabel - Return true if the statement contains a label in it.  If
4497   /// this statement is not executed normally, it not containing a label means
4498   /// that we can just remove the code.
4499   static bool ContainsLabel(const Stmt *S, bool IgnoreCaseStmts = false);
4500 
4501   /// containsBreak - Return true if the statement contains a break out of it.
4502   /// If the statement (recursively) contains a switch or loop with a break
4503   /// inside of it, this is fine.
4504   static bool containsBreak(const Stmt *S);
4505 
4506   /// Determine if the given statement might introduce a declaration into the
4507   /// current scope, by being a (possibly-labelled) DeclStmt.
4508   static bool mightAddDeclToScope(const Stmt *S);
4509 
4510   /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
4511   /// to a constant, or if it does but contains a label, return false.  If it
4512   /// constant folds return true and set the boolean result in Result.
4513   bool ConstantFoldsToSimpleInteger(const Expr *Cond, bool &Result,
4514                                     bool AllowLabels = false);
4515 
4516   /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
4517   /// to a constant, or if it does but contains a label, return false.  If it
4518   /// constant folds return true and set the folded value.
4519   bool ConstantFoldsToSimpleInteger(const Expr *Cond, llvm::APSInt &Result,
4520                                     bool AllowLabels = false);
4521 
4522   /// isInstrumentedCondition - Determine whether the given condition is an
4523   /// instrumentable condition (i.e. no "&&" or "||").
4524   static bool isInstrumentedCondition(const Expr *C);
4525 
4526   /// EmitBranchToCounterBlock - Emit a conditional branch to a new block that
4527   /// increments a profile counter based on the semantics of the given logical
4528   /// operator opcode.  This is used to instrument branch condition coverage
4529   /// for logical operators.
4530   void EmitBranchToCounterBlock(const Expr *Cond, BinaryOperator::Opcode LOp,
4531                                 llvm::BasicBlock *TrueBlock,
4532                                 llvm::BasicBlock *FalseBlock,
4533                                 uint64_t TrueCount = 0,
4534                                 Stmt::Likelihood LH = Stmt::LH_None,
4535                                 const Expr *CntrIdx = nullptr);
4536 
4537   /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an
4538   /// if statement) to the specified blocks.  Based on the condition, this might
4539   /// try to simplify the codegen of the conditional based on the branch.
4540   /// TrueCount should be the number of times we expect the condition to
4541   /// evaluate to true based on PGO data.
4542   void EmitBranchOnBoolExpr(const Expr *Cond, llvm::BasicBlock *TrueBlock,
4543                             llvm::BasicBlock *FalseBlock, uint64_t TrueCount,
4544                             Stmt::Likelihood LH = Stmt::LH_None);
4545 
4546   /// Given an assignment `*LHS = RHS`, emit a test that checks if \p RHS is
4547   /// nonnull, if \p LHS is marked _Nonnull.
4548   void EmitNullabilityCheck(LValue LHS, llvm::Value *RHS, SourceLocation Loc);
4549 
4550   /// An enumeration which makes it easier to specify whether or not an
4551   /// operation is a subtraction.
4552   enum { NotSubtraction = false, IsSubtraction = true };
4553 
4554   /// Same as IRBuilder::CreateInBoundsGEP, but additionally emits a check to
4555   /// detect undefined behavior when the pointer overflow sanitizer is enabled.
4556   /// \p SignedIndices indicates whether any of the GEP indices are signed.
4557   /// \p IsSubtraction indicates whether the expression used to form the GEP
4558   /// is a subtraction.
4559   llvm::Value *EmitCheckedInBoundsGEP(llvm::Value *Ptr,
4560                                       ArrayRef<llvm::Value *> IdxList,
4561                                       bool SignedIndices,
4562                                       bool IsSubtraction,
4563                                       SourceLocation Loc,
4564                                       const Twine &Name = "");
4565 
4566   /// Specifies which type of sanitizer check to apply when handling a
4567   /// particular builtin.
4568   enum BuiltinCheckKind {
4569     BCK_CTZPassedZero,
4570     BCK_CLZPassedZero,
4571   };
4572 
4573   /// Emits an argument for a call to a builtin. If the builtin sanitizer is
4574   /// enabled, a runtime check specified by \p Kind is also emitted.
4575   llvm::Value *EmitCheckedArgForBuiltin(const Expr *E, BuiltinCheckKind Kind);
4576 
4577   /// Emit a description of a type in a format suitable for passing to
4578   /// a runtime sanitizer handler.
4579   llvm::Constant *EmitCheckTypeDescriptor(QualType T);
4580 
4581   /// Convert a value into a format suitable for passing to a runtime
4582   /// sanitizer handler.
4583   llvm::Value *EmitCheckValue(llvm::Value *V);
4584 
4585   /// Emit a description of a source location in a format suitable for
4586   /// passing to a runtime sanitizer handler.
4587   llvm::Constant *EmitCheckSourceLocation(SourceLocation Loc);
4588 
4589   /// Create a basic block that will either trap or call a handler function in
4590   /// the UBSan runtime with the provided arguments, and create a conditional
4591   /// branch to it.
4592   void EmitCheck(ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
4593                  SanitizerHandler Check, ArrayRef<llvm::Constant *> StaticArgs,
4594                  ArrayRef<llvm::Value *> DynamicArgs);
4595 
4596   /// Emit a slow path cross-DSO CFI check which calls __cfi_slowpath
4597   /// if Cond if false.
4598   void EmitCfiSlowPathCheck(SanitizerMask Kind, llvm::Value *Cond,
4599                             llvm::ConstantInt *TypeId, llvm::Value *Ptr,
4600                             ArrayRef<llvm::Constant *> StaticArgs);
4601 
4602   /// Emit a reached-unreachable diagnostic if \p Loc is valid and runtime
4603   /// checking is enabled. Otherwise, just emit an unreachable instruction.
4604   void EmitUnreachable(SourceLocation Loc);
4605 
4606   /// Create a basic block that will call the trap intrinsic, and emit a
4607   /// conditional branch to it, for the -ftrapv checks.
4608   void EmitTrapCheck(llvm::Value *Checked, SanitizerHandler CheckHandlerID);
4609 
4610   /// Emit a call to trap or debugtrap and attach function attribute
4611   /// "trap-func-name" if specified.
4612   llvm::CallInst *EmitTrapCall(llvm::Intrinsic::ID IntrID);
4613 
4614   /// Emit a stub for the cross-DSO CFI check function.
4615   void EmitCfiCheckStub();
4616 
4617   /// Emit a cross-DSO CFI failure handling function.
4618   void EmitCfiCheckFail();
4619 
4620   /// Create a check for a function parameter that may potentially be
4621   /// declared as non-null.
4622   void EmitNonNullArgCheck(RValue RV, QualType ArgType, SourceLocation ArgLoc,
4623                            AbstractCallee AC, unsigned ParmNum);
4624 
4625   /// EmitCallArg - Emit a single call argument.
4626   void EmitCallArg(CallArgList &args, const Expr *E, QualType ArgType);
4627 
4628   /// EmitDelegateCallArg - We are performing a delegate call; that
4629   /// is, the current function is delegating to another one.  Produce
4630   /// a r-value suitable for passing the given parameter.
4631   void EmitDelegateCallArg(CallArgList &args, const VarDecl *param,
4632                            SourceLocation loc);
4633 
4634   /// SetFPAccuracy - Set the minimum required accuracy of the given floating
4635   /// point operation, expressed as the maximum relative error in ulp.
4636   void SetFPAccuracy(llvm::Value *Val, float Accuracy);
4637 
4638   /// Set the codegen fast-math flags.
4639   void SetFastMathFlags(FPOptions FPFeatures);
4640 
4641 private:
4642   llvm::MDNode *getRangeForLoadFromType(QualType Ty);
4643   void EmitReturnOfRValue(RValue RV, QualType Ty);
4644 
4645   void deferPlaceholderReplacement(llvm::Instruction *Old, llvm::Value *New);
4646 
4647   llvm::SmallVector<std::pair<llvm::WeakTrackingVH, llvm::Value *>, 4>
4648       DeferredReplacements;
4649 
4650   /// Set the address of a local variable.
4651   void setAddrOfLocalVar(const VarDecl *VD, Address Addr) {
4652     assert(!LocalDeclMap.count(VD) && "Decl already exists in LocalDeclMap!");
4653     LocalDeclMap.insert({VD, Addr});
4654   }
4655 
4656   /// ExpandTypeFromArgs - Reconstruct a structure of type \arg Ty
4657   /// from function arguments into \arg Dst. See ABIArgInfo::Expand.
4658   ///
4659   /// \param AI - The first function argument of the expansion.
4660   void ExpandTypeFromArgs(QualType Ty, LValue Dst,
4661                           llvm::Function::arg_iterator &AI);
4662 
4663   /// ExpandTypeToArgs - Expand an CallArg \arg Arg, with the LLVM type for \arg
4664   /// Ty, into individual arguments on the provided vector \arg IRCallArgs,
4665   /// starting at index \arg IRCallArgPos. See ABIArgInfo::Expand.
4666   void ExpandTypeToArgs(QualType Ty, CallArg Arg, llvm::FunctionType *IRFuncTy,
4667                         SmallVectorImpl<llvm::Value *> &IRCallArgs,
4668                         unsigned &IRCallArgPos);
4669 
4670   llvm::Value* EmitAsmInput(const TargetInfo::ConstraintInfo &Info,
4671                             const Expr *InputExpr, std::string &ConstraintStr);
4672 
4673   llvm::Value* EmitAsmInputLValue(const TargetInfo::ConstraintInfo &Info,
4674                                   LValue InputValue, QualType InputType,
4675                                   std::string &ConstraintStr,
4676                                   SourceLocation Loc);
4677 
4678   /// Attempts to statically evaluate the object size of E. If that
4679   /// fails, emits code to figure the size of E out for us. This is
4680   /// pass_object_size aware.
4681   ///
4682   /// If EmittedExpr is non-null, this will use that instead of re-emitting E.
4683   llvm::Value *evaluateOrEmitBuiltinObjectSize(const Expr *E, unsigned Type,
4684                                                llvm::IntegerType *ResType,
4685                                                llvm::Value *EmittedE,
4686                                                bool IsDynamic);
4687 
4688   /// Emits the size of E, as required by __builtin_object_size. This
4689   /// function is aware of pass_object_size parameters, and will act accordingly
4690   /// if E is a parameter with the pass_object_size attribute.
4691   llvm::Value *emitBuiltinObjectSize(const Expr *E, unsigned Type,
4692                                      llvm::IntegerType *ResType,
4693                                      llvm::Value *EmittedE,
4694                                      bool IsDynamic);
4695 
4696   void emitZeroOrPatternForAutoVarInit(QualType type, const VarDecl &D,
4697                                        Address Loc);
4698 
4699 public:
4700   enum class EvaluationOrder {
4701     ///! No language constraints on evaluation order.
4702     Default,
4703     ///! Language semantics require left-to-right evaluation.
4704     ForceLeftToRight,
4705     ///! Language semantics require right-to-left evaluation.
4706     ForceRightToLeft
4707   };
4708 
4709   // Wrapper for function prototype sources. Wraps either a FunctionProtoType or
4710   // an ObjCMethodDecl.
4711   struct PrototypeWrapper {
4712     llvm::PointerUnion<const FunctionProtoType *, const ObjCMethodDecl *> P;
4713 
4714     PrototypeWrapper(const FunctionProtoType *FT) : P(FT) {}
4715     PrototypeWrapper(const ObjCMethodDecl *MD) : P(MD) {}
4716   };
4717 
4718   void EmitCallArgs(CallArgList &Args, PrototypeWrapper Prototype,
4719                     llvm::iterator_range<CallExpr::const_arg_iterator> ArgRange,
4720                     AbstractCallee AC = AbstractCallee(),
4721                     unsigned ParamsToSkip = 0,
4722                     EvaluationOrder Order = EvaluationOrder::Default);
4723 
4724   /// EmitPointerWithAlignment - Given an expression with a pointer type,
4725   /// emit the value and compute our best estimate of the alignment of the
4726   /// pointee.
4727   ///
4728   /// \param BaseInfo - If non-null, this will be initialized with
4729   /// information about the source of the alignment and the may-alias
4730   /// attribute.  Note that this function will conservatively fall back on
4731   /// the type when it doesn't recognize the expression and may-alias will
4732   /// be set to false.
4733   ///
4734   /// One reasonable way to use this information is when there's a language
4735   /// guarantee that the pointer must be aligned to some stricter value, and
4736   /// we're simply trying to ensure that sufficiently obvious uses of under-
4737   /// aligned objects don't get miscompiled; for example, a placement new
4738   /// into the address of a local variable.  In such a case, it's quite
4739   /// reasonable to just ignore the returned alignment when it isn't from an
4740   /// explicit source.
4741   Address EmitPointerWithAlignment(const Expr *Addr,
4742                                    LValueBaseInfo *BaseInfo = nullptr,
4743                                    TBAAAccessInfo *TBAAInfo = nullptr);
4744 
4745   /// If \p E references a parameter with pass_object_size info or a constant
4746   /// array size modifier, emit the object size divided by the size of \p EltTy.
4747   /// Otherwise return null.
4748   llvm::Value *LoadPassedObjectSize(const Expr *E, QualType EltTy);
4749 
4750   void EmitSanitizerStatReport(llvm::SanitizerStatKind SSK);
4751 
4752   struct MultiVersionResolverOption {
4753     llvm::Function *Function;
4754     struct Conds {
4755       StringRef Architecture;
4756       llvm::SmallVector<StringRef, 8> Features;
4757 
4758       Conds(StringRef Arch, ArrayRef<StringRef> Feats)
4759           : Architecture(Arch), Features(Feats.begin(), Feats.end()) {}
4760     } Conditions;
4761 
4762     MultiVersionResolverOption(llvm::Function *F, StringRef Arch,
4763                                ArrayRef<StringRef> Feats)
4764         : Function(F), Conditions(Arch, Feats) {}
4765   };
4766 
4767   // Emits the body of a multiversion function's resolver. Assumes that the
4768   // options are already sorted in the proper order, with the 'default' option
4769   // last (if it exists).
4770   void EmitMultiVersionResolver(llvm::Function *Resolver,
4771                                 ArrayRef<MultiVersionResolverOption> Options);
4772 
4773 private:
4774   QualType getVarArgType(const Expr *Arg);
4775 
4776   void EmitDeclMetadata();
4777 
4778   BlockByrefHelpers *buildByrefHelpers(llvm::StructType &byrefType,
4779                                   const AutoVarEmission &emission);
4780 
4781   void AddObjCARCExceptionMetadata(llvm::Instruction *Inst);
4782 
4783   llvm::Value *GetValueForARMHint(unsigned BuiltinID);
4784   llvm::Value *EmitX86CpuIs(const CallExpr *E);
4785   llvm::Value *EmitX86CpuIs(StringRef CPUStr);
4786   llvm::Value *EmitX86CpuSupports(const CallExpr *E);
4787   llvm::Value *EmitX86CpuSupports(ArrayRef<StringRef> FeatureStrs);
4788   llvm::Value *EmitX86CpuSupports(uint64_t Mask);
4789   llvm::Value *EmitX86CpuInit();
4790   llvm::Value *FormResolverCondition(const MultiVersionResolverOption &RO);
4791 };
4792 
4793 /// TargetFeatures - This class is used to check whether the builtin function
4794 /// has the required tagert specific features. It is able to support the
4795 /// combination of ','(and), '|'(or), and '()'. By default, the priority of
4796 /// ',' is higher than that of '|' .
4797 /// E.g:
4798 /// A,B|C means the builtin function requires both A and B, or C.
4799 /// If we want the builtin function requires both A and B, or both A and C,
4800 /// there are two ways: A,B|A,C or A,(B|C).
4801 /// The FeaturesList should not contain spaces, and brackets must appear in
4802 /// pairs.
4803 class TargetFeatures {
4804   struct FeatureListStatus {
4805     bool HasFeatures;
4806     StringRef CurFeaturesList;
4807   };
4808 
4809   const llvm::StringMap<bool> &CallerFeatureMap;
4810 
4811   FeatureListStatus getAndFeatures(StringRef FeatureList) {
4812     int InParentheses = 0;
4813     bool HasFeatures = true;
4814     size_t SubexpressionStart = 0;
4815     for (size_t i = 0, e = FeatureList.size(); i < e; ++i) {
4816       char CurrentToken = FeatureList[i];
4817       switch (CurrentToken) {
4818       default:
4819         break;
4820       case '(':
4821         if (InParentheses == 0)
4822           SubexpressionStart = i + 1;
4823         ++InParentheses;
4824         break;
4825       case ')':
4826         --InParentheses;
4827         assert(InParentheses >= 0 && "Parentheses are not in pair");
4828         LLVM_FALLTHROUGH;
4829       case '|':
4830       case ',':
4831         if (InParentheses == 0) {
4832           if (HasFeatures && i != SubexpressionStart) {
4833             StringRef F = FeatureList.slice(SubexpressionStart, i);
4834             HasFeatures = CurrentToken == ')' ? hasRequiredFeatures(F)
4835                                               : CallerFeatureMap.lookup(F);
4836           }
4837           SubexpressionStart = i + 1;
4838           if (CurrentToken == '|') {
4839             return {HasFeatures, FeatureList.substr(SubexpressionStart)};
4840           }
4841         }
4842         break;
4843       }
4844     }
4845     assert(InParentheses == 0 && "Parentheses are not in pair");
4846     if (HasFeatures && SubexpressionStart != FeatureList.size())
4847       HasFeatures =
4848           CallerFeatureMap.lookup(FeatureList.substr(SubexpressionStart));
4849     return {HasFeatures, StringRef()};
4850   }
4851 
4852 public:
4853   bool hasRequiredFeatures(StringRef FeatureList) {
4854     FeatureListStatus FS = {false, FeatureList};
4855     while (!FS.HasFeatures && !FS.CurFeaturesList.empty())
4856       FS = getAndFeatures(FS.CurFeaturesList);
4857     return FS.HasFeatures;
4858   }
4859 
4860   TargetFeatures(const llvm::StringMap<bool> &CallerFeatureMap)
4861       : CallerFeatureMap(CallerFeatureMap) {}
4862 };
4863 
4864 inline DominatingLLVMValue::saved_type
4865 DominatingLLVMValue::save(CodeGenFunction &CGF, llvm::Value *value) {
4866   if (!needsSaving(value)) return saved_type(value, false);
4867 
4868   // Otherwise, we need an alloca.
4869   auto align = CharUnits::fromQuantity(
4870             CGF.CGM.getDataLayout().getPrefTypeAlignment(value->getType()));
4871   Address alloca =
4872     CGF.CreateTempAlloca(value->getType(), align, "cond-cleanup.save");
4873   CGF.Builder.CreateStore(value, alloca);
4874 
4875   return saved_type(alloca.getPointer(), true);
4876 }
4877 
4878 inline llvm::Value *DominatingLLVMValue::restore(CodeGenFunction &CGF,
4879                                                  saved_type value) {
4880   // If the value says it wasn't saved, trust that it's still dominating.
4881   if (!value.getInt()) return value.getPointer();
4882 
4883   // Otherwise, it should be an alloca instruction, as set up in save().
4884   auto alloca = cast<llvm::AllocaInst>(value.getPointer());
4885   return CGF.Builder.CreateAlignedLoad(alloca->getAllocatedType(), alloca,
4886                                        alloca->getAlign());
4887 }
4888 
4889 }  // end namespace CodeGen
4890 
4891 // Map the LangOption for floating point exception behavior into
4892 // the corresponding enum in the IR.
4893 llvm::fp::ExceptionBehavior
4894 ToConstrainedExceptMD(LangOptions::FPExceptionModeKind Kind);
4895 }  // end namespace clang
4896 
4897 #endif
4898