Home | History | Annotate | Line # | Download | only in CodeGen
      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   // CodeGen lambda for loops and support for ordered clause
    295   typedef llvm::function_ref<void(CodeGenFunction &, const OMPLoopDirective &,
    296                                   JumpDest)>
    297       CodeGenLoopTy;
    298   typedef llvm::function_ref<void(CodeGenFunction &, SourceLocation,
    299                                   const unsigned, const bool)>
    300       CodeGenOrderedTy;
    301 
    302   // Codegen lambda for loop bounds in worksharing loop constructs
    303   typedef llvm::function_ref<std::pair<LValue, LValue>(
    304       CodeGenFunction &, const OMPExecutableDirective &S)>
    305       CodeGenLoopBoundsTy;
    306 
    307   // Codegen lambda for loop bounds in dispatch-based loop implementation
    308   typedef llvm::function_ref<std::pair<llvm::Value *, llvm::Value *>(
    309       CodeGenFunction &, const OMPExecutableDirective &S, Address LB,
    310       Address UB)>
    311       CodeGenDispatchBoundsTy;
    312 
    313   /// CGBuilder insert helper. This function is called after an
    314   /// instruction is created using Builder.
    315   void InsertHelper(llvm::Instruction *I, const llvm::Twine &Name,
    316                     llvm::BasicBlock *BB,
    317                     llvm::BasicBlock::iterator InsertPt) const;
    318 
    319   /// CurFuncDecl - Holds the Decl for the current outermost
    320   /// non-closure context.
    321   const Decl *CurFuncDecl;
    322   /// CurCodeDecl - This is the inner-most code context, which includes blocks.
    323   const Decl *CurCodeDecl;
    324   const CGFunctionInfo *CurFnInfo;
    325   QualType FnRetTy;
    326   llvm::Function *CurFn = nullptr;
    327 
    328   /// Save Parameter Decl for coroutine.
    329   llvm::SmallVector<const ParmVarDecl *, 4> FnArgs;
    330 
    331   // Holds coroutine data if the current function is a coroutine. We use a
    332   // wrapper to manage its lifetime, so that we don't have to define CGCoroData
    333   // in this header.
    334   struct CGCoroInfo {
    335     std::unique_ptr<CGCoroData> Data;
    336     CGCoroInfo();
    337     ~CGCoroInfo();
    338   };
    339   CGCoroInfo CurCoro;
    340 
    341   bool isCoroutine() const {
    342     return CurCoro.Data != nullptr;
    343   }
    344 
    345   /// CurGD - The GlobalDecl for the current function being compiled.
    346   GlobalDecl CurGD;
    347 
    348   /// PrologueCleanupDepth - The cleanup depth enclosing all the
    349   /// cleanups associated with the parameters.
    350   EHScopeStack::stable_iterator PrologueCleanupDepth;
    351 
    352   /// ReturnBlock - Unified return block.
    353   JumpDest ReturnBlock;
    354 
    355   /// ReturnValue - The temporary alloca to hold the return
    356   /// value. This is invalid iff the function has no return value.
    357   Address ReturnValue = Address::invalid();
    358 
    359   /// ReturnValuePointer - The temporary alloca to hold a pointer to sret.
    360   /// This is invalid if sret is not in use.
    361   Address ReturnValuePointer = Address::invalid();
    362 
    363   /// If a return statement is being visited, this holds the return statment's
    364   /// result expression.
    365   const Expr *RetExpr = nullptr;
    366 
    367   /// Return true if a label was seen in the current scope.
    368   bool hasLabelBeenSeenInCurrentScope() const {
    369     if (CurLexicalScope)
    370       return CurLexicalScope->hasLabels();
    371     return !LabelMap.empty();
    372   }
    373 
    374   /// AllocaInsertPoint - This is an instruction in the entry block before which
    375   /// we prefer to insert allocas.
    376   llvm::AssertingVH<llvm::Instruction> AllocaInsertPt;
    377 
    378   /// API for captured statement code generation.
    379   class CGCapturedStmtInfo {
    380   public:
    381     explicit CGCapturedStmtInfo(CapturedRegionKind K = CR_Default)
    382         : Kind(K), ThisValue(nullptr), CXXThisFieldDecl(nullptr) {}
    383     explicit CGCapturedStmtInfo(const CapturedStmt &S,
    384                                 CapturedRegionKind K = CR_Default)
    385       : Kind(K), ThisValue(nullptr), CXXThisFieldDecl(nullptr) {
    386 
    387       RecordDecl::field_iterator Field =
    388         S.getCapturedRecordDecl()->field_begin();
    389       for (CapturedStmt::const_capture_iterator I = S.capture_begin(),
    390                                                 E = S.capture_end();
    391            I != E; ++I, ++Field) {
    392         if (I->capturesThis())
    393           CXXThisFieldDecl = *Field;
    394         else if (I->capturesVariable())
    395           CaptureFields[I->getCapturedVar()->getCanonicalDecl()] = *Field;
    396         else if (I->capturesVariableByCopy())
    397           CaptureFields[I->getCapturedVar()->getCanonicalDecl()] = *Field;
    398       }
    399     }
    400 
    401     virtual ~CGCapturedStmtInfo();
    402 
    403     CapturedRegionKind getKind() const { return Kind; }
    404 
    405     virtual void setContextValue(llvm::Value *V) { ThisValue = V; }
    406     // Retrieve the value of the context parameter.
    407     virtual llvm::Value *getContextValue() const { return ThisValue; }
    408 
    409     /// Lookup the captured field decl for a variable.
    410     virtual const FieldDecl *lookup(const VarDecl *VD) const {
    411       return CaptureFields.lookup(VD->getCanonicalDecl());
    412     }
    413 
    414     bool isCXXThisExprCaptured() const { return getThisFieldDecl() != nullptr; }
    415     virtual FieldDecl *getThisFieldDecl() const { return CXXThisFieldDecl; }
    416 
    417     static bool classof(const CGCapturedStmtInfo *) {
    418       return true;
    419     }
    420 
    421     /// Emit the captured statement body.
    422     virtual void EmitBody(CodeGenFunction &CGF, const Stmt *S) {
    423       CGF.incrementProfileCounter(S);
    424       CGF.EmitStmt(S);
    425     }
    426 
    427     /// Get the name of the capture helper.
    428     virtual StringRef getHelperName() const { return "__captured_stmt"; }
    429 
    430   private:
    431     /// The kind of captured statement being generated.
    432     CapturedRegionKind Kind;
    433 
    434     /// Keep the map between VarDecl and FieldDecl.
    435     llvm::SmallDenseMap<const VarDecl *, FieldDecl *> CaptureFields;
    436 
    437     /// The base address of the captured record, passed in as the first
    438     /// argument of the parallel region function.
    439     llvm::Value *ThisValue;
    440 
    441     /// Captured 'this' type.
    442     FieldDecl *CXXThisFieldDecl;
    443   };
    444   CGCapturedStmtInfo *CapturedStmtInfo = nullptr;
    445 
    446   /// RAII for correct setting/restoring of CapturedStmtInfo.
    447   class CGCapturedStmtRAII {
    448   private:
    449     CodeGenFunction &CGF;
    450     CGCapturedStmtInfo *PrevCapturedStmtInfo;
    451   public:
    452     CGCapturedStmtRAII(CodeGenFunction &CGF,
    453                        CGCapturedStmtInfo *NewCapturedStmtInfo)
    454         : CGF(CGF), PrevCapturedStmtInfo(CGF.CapturedStmtInfo) {
    455       CGF.CapturedStmtInfo = NewCapturedStmtInfo;
    456     }
    457     ~CGCapturedStmtRAII() { CGF.CapturedStmtInfo = PrevCapturedStmtInfo; }
    458   };
    459 
    460   /// An abstract representation of regular/ObjC call/message targets.
    461   class AbstractCallee {
    462     /// The function declaration of the callee.
    463     const Decl *CalleeDecl;
    464 
    465   public:
    466     AbstractCallee() : CalleeDecl(nullptr) {}
    467     AbstractCallee(const FunctionDecl *FD) : CalleeDecl(FD) {}
    468     AbstractCallee(const ObjCMethodDecl *OMD) : CalleeDecl(OMD) {}
    469     bool hasFunctionDecl() const {
    470       return dyn_cast_or_null<FunctionDecl>(CalleeDecl);
    471     }
    472     const Decl *getDecl() const { return CalleeDecl; }
    473     unsigned getNumParams() const {
    474       if (const auto *FD = dyn_cast<FunctionDecl>(CalleeDecl))
    475         return FD->getNumParams();
    476       return cast<ObjCMethodDecl>(CalleeDecl)->param_size();
    477     }
    478     const ParmVarDecl *getParamDecl(unsigned I) const {
    479       if (const auto *FD = dyn_cast<FunctionDecl>(CalleeDecl))
    480         return FD->getParamDecl(I);
    481       return *(cast<ObjCMethodDecl>(CalleeDecl)->param_begin() + I);
    482     }
    483   };
    484 
    485   /// Sanitizers enabled for this function.
    486   SanitizerSet SanOpts;
    487 
    488   /// True if CodeGen currently emits code implementing sanitizer checks.
    489   bool IsSanitizerScope = false;
    490 
    491   /// RAII object to set/unset CodeGenFunction::IsSanitizerScope.
    492   class SanitizerScope {
    493     CodeGenFunction *CGF;
    494   public:
    495     SanitizerScope(CodeGenFunction *CGF);
    496     ~SanitizerScope();
    497   };
    498 
    499   /// In C++, whether we are code generating a thunk.  This controls whether we
    500   /// should emit cleanups.
    501   bool CurFuncIsThunk = false;
    502 
    503   /// In ARC, whether we should autorelease the return value.
    504   bool AutoreleaseResult = false;
    505 
    506   /// Whether we processed a Microsoft-style asm block during CodeGen. These can
    507   /// potentially set the return value.
    508   bool SawAsmBlock = false;
    509 
    510   const NamedDecl *CurSEHParent = nullptr;
    511 
    512   /// True if the current function is an outlined SEH helper. This can be a
    513   /// finally block or filter expression.
    514   bool IsOutlinedSEHHelper = false;
    515 
    516   /// True if CodeGen currently emits code inside presereved access index
    517   /// region.
    518   bool IsInPreservedAIRegion = false;
    519 
    520   /// True if the current statement has nomerge attribute.
    521   bool InNoMergeAttributedStmt = false;
    522 
    523   // The CallExpr within the current statement that the musttail attribute
    524   // applies to.  nullptr if there is no 'musttail' on the current statement.
    525   const CallExpr *MustTailCall = nullptr;
    526 
    527   /// Returns true if a function must make progress, which means the
    528   /// mustprogress attribute can be added.
    529   bool checkIfFunctionMustProgress() {
    530     if (CGM.getCodeGenOpts().getFiniteLoops() ==
    531         CodeGenOptions::FiniteLoopsKind::Never)
    532       return false;
    533 
    534     // C++11 and later guarantees that a thread eventually will do one of the
    535     // following (6.9.2.3.1 in C++11):
    536     // - terminate,
    537     //  - make a call to a library I/O function,
    538     //  - perform an access through a volatile glvalue, or
    539     //  - perform a synchronization operation or an atomic operation.
    540     //
    541     // Hence each function is 'mustprogress' in C++11 or later.
    542     return getLangOpts().CPlusPlus11;
    543   }
    544 
    545   /// Returns true if a loop must make progress, which means the mustprogress
    546   /// attribute can be added. \p HasConstantCond indicates whether the branch
    547   /// condition is a known constant.
    548   bool checkIfLoopMustProgress(bool HasConstantCond) {
    549     if (CGM.getCodeGenOpts().getFiniteLoops() ==
    550         CodeGenOptions::FiniteLoopsKind::Always)
    551       return true;
    552     if (CGM.getCodeGenOpts().getFiniteLoops() ==
    553         CodeGenOptions::FiniteLoopsKind::Never)
    554       return false;
    555 
    556     // If the containing function must make progress, loops also must make
    557     // progress (as in C++11 and later).
    558     if (checkIfFunctionMustProgress())
    559       return true;
    560 
    561     // Now apply rules for plain C (see  6.8.5.6 in C11).
    562     // Loops with constant conditions do not have to make progress in any C
    563     // version.
    564     if (HasConstantCond)
    565       return false;
    566 
    567     // Loops with non-constant conditions must make progress in C11 and later.
    568     return getLangOpts().C11;
    569   }
    570 
    571   const CodeGen::CGBlockInfo *BlockInfo = nullptr;
    572   llvm::Value *BlockPointer = nullptr;
    573 
    574   llvm::DenseMap<const VarDecl *, FieldDecl *> LambdaCaptureFields;
    575   FieldDecl *LambdaThisCaptureField = nullptr;
    576 
    577   /// A mapping from NRVO variables to the flags used to indicate
    578   /// when the NRVO has been applied to this variable.
    579   llvm::DenseMap<const VarDecl *, llvm::Value *> NRVOFlags;
    580 
    581   EHScopeStack EHStack;
    582   llvm::SmallVector<char, 256> LifetimeExtendedCleanupStack;
    583   llvm::SmallVector<const JumpDest *, 2> SEHTryEpilogueStack;
    584 
    585   llvm::Instruction *CurrentFuncletPad = nullptr;
    586 
    587   class CallLifetimeEnd final : public EHScopeStack::Cleanup {
    588     bool isRedundantBeforeReturn() override { return true; }
    589 
    590     llvm::Value *Addr;
    591     llvm::Value *Size;
    592 
    593   public:
    594     CallLifetimeEnd(Address addr, llvm::Value *size)
    595         : Addr(addr.getPointer()), Size(size) {}
    596 
    597     void Emit(CodeGenFunction &CGF, Flags flags) override {
    598       CGF.EmitLifetimeEnd(Size, Addr);
    599     }
    600   };
    601 
    602   /// Header for data within LifetimeExtendedCleanupStack.
    603   struct LifetimeExtendedCleanupHeader {
    604     /// The size of the following cleanup object.
    605     unsigned Size;
    606     /// The kind of cleanup to push: a value from the CleanupKind enumeration.
    607     unsigned Kind : 31;
    608     /// Whether this is a conditional cleanup.
    609     unsigned IsConditional : 1;
    610 
    611     size_t getSize() const { return Size; }
    612     CleanupKind getKind() const { return (CleanupKind)Kind; }
    613     bool isConditional() const { return IsConditional; }
    614   };
    615 
    616   /// i32s containing the indexes of the cleanup destinations.
    617   Address NormalCleanupDest = Address::invalid();
    618 
    619   unsigned NextCleanupDestIndex = 1;
    620 
    621   /// EHResumeBlock - Unified block containing a call to llvm.eh.resume.
    622   llvm::BasicBlock *EHResumeBlock = nullptr;
    623 
    624   /// The exception slot.  All landing pads write the current exception pointer
    625   /// into this alloca.
    626   llvm::Value *ExceptionSlot = nullptr;
    627 
    628   /// The selector slot.  Under the MandatoryCleanup model, all landing pads
    629   /// write the current selector value into this alloca.
    630   llvm::AllocaInst *EHSelectorSlot = nullptr;
    631 
    632   /// A stack of exception code slots. Entering an __except block pushes a slot
    633   /// on the stack and leaving pops one. The __exception_code() intrinsic loads
    634   /// a value from the top of the stack.
    635   SmallVector<Address, 1> SEHCodeSlotStack;
    636 
    637   /// Value returned by __exception_info intrinsic.
    638   llvm::Value *SEHInfo = nullptr;
    639 
    640   /// Emits a landing pad for the current EH stack.
    641   llvm::BasicBlock *EmitLandingPad();
    642 
    643   llvm::BasicBlock *getInvokeDestImpl();
    644 
    645   /// Parent loop-based directive for scan directive.
    646   const OMPExecutableDirective *OMPParentLoopDirectiveForScan = nullptr;
    647   llvm::BasicBlock *OMPBeforeScanBlock = nullptr;
    648   llvm::BasicBlock *OMPAfterScanBlock = nullptr;
    649   llvm::BasicBlock *OMPScanExitBlock = nullptr;
    650   llvm::BasicBlock *OMPScanDispatch = nullptr;
    651   bool OMPFirstScanLoop = false;
    652 
    653   /// Manages parent directive for scan directives.
    654   class ParentLoopDirectiveForScanRegion {
    655     CodeGenFunction &CGF;
    656     const OMPExecutableDirective *ParentLoopDirectiveForScan;
    657 
    658   public:
    659     ParentLoopDirectiveForScanRegion(
    660         CodeGenFunction &CGF,
    661         const OMPExecutableDirective &ParentLoopDirectiveForScan)
    662         : CGF(CGF),
    663           ParentLoopDirectiveForScan(CGF.OMPParentLoopDirectiveForScan) {
    664       CGF.OMPParentLoopDirectiveForScan = &ParentLoopDirectiveForScan;
    665     }
    666     ~ParentLoopDirectiveForScanRegion() {
    667       CGF.OMPParentLoopDirectiveForScan = ParentLoopDirectiveForScan;
    668     }
    669   };
    670 
    671   template <class T>
    672   typename DominatingValue<T>::saved_type saveValueInCond(T value) {
    673     return DominatingValue<T>::save(*this, value);
    674   }
    675 
    676   class CGFPOptionsRAII {
    677   public:
    678     CGFPOptionsRAII(CodeGenFunction &CGF, FPOptions FPFeatures);
    679     CGFPOptionsRAII(CodeGenFunction &CGF, const Expr *E);
    680     ~CGFPOptionsRAII();
    681 
    682   private:
    683     void ConstructorHelper(FPOptions FPFeatures);
    684     CodeGenFunction &CGF;
    685     FPOptions OldFPFeatures;
    686     llvm::fp::ExceptionBehavior OldExcept;
    687     llvm::RoundingMode OldRounding;
    688     Optional<CGBuilderTy::FastMathFlagGuard> FMFGuard;
    689   };
    690   FPOptions CurFPFeatures;
    691 
    692 public:
    693   /// ObjCEHValueStack - Stack of Objective-C exception values, used for
    694   /// rethrows.
    695   SmallVector<llvm::Value*, 8> ObjCEHValueStack;
    696 
    697   /// A class controlling the emission of a finally block.
    698   class FinallyInfo {
    699     /// Where the catchall's edge through the cleanup should go.
    700     JumpDest RethrowDest;
    701 
    702     /// A function to call to enter the catch.
    703     llvm::FunctionCallee BeginCatchFn;
    704 
    705     /// An i1 variable indicating whether or not the @finally is
    706     /// running for an exception.
    707     llvm::AllocaInst *ForEHVar;
    708 
    709     /// An i8* variable into which the exception pointer to rethrow
    710     /// has been saved.
    711     llvm::AllocaInst *SavedExnVar;
    712 
    713   public:
    714     void enter(CodeGenFunction &CGF, const Stmt *Finally,
    715                llvm::FunctionCallee beginCatchFn,
    716                llvm::FunctionCallee endCatchFn, llvm::FunctionCallee rethrowFn);
    717     void exit(CodeGenFunction &CGF);
    718   };
    719 
    720   /// Returns true inside SEH __try blocks.
    721   bool isSEHTryScope() const { return !SEHTryEpilogueStack.empty(); }
    722 
    723   /// Returns true while emitting a cleanuppad.
    724   bool isCleanupPadScope() const {
    725     return CurrentFuncletPad && isa<llvm::CleanupPadInst>(CurrentFuncletPad);
    726   }
    727 
    728   /// pushFullExprCleanup - Push a cleanup to be run at the end of the
    729   /// current full-expression.  Safe against the possibility that
    730   /// we're currently inside a conditionally-evaluated expression.
    731   template <class T, class... As>
    732   void pushFullExprCleanup(CleanupKind kind, As... A) {
    733     // If we're not in a conditional branch, or if none of the
    734     // arguments requires saving, then use the unconditional cleanup.
    735     if (!isInConditionalBranch())
    736       return EHStack.pushCleanup<T>(kind, A...);
    737 
    738     // Stash values in a tuple so we can guarantee the order of saves.
    739     typedef std::tuple<typename DominatingValue<As>::saved_type...> SavedTuple;
    740     SavedTuple Saved{saveValueInCond(A)...};
    741 
    742     typedef EHScopeStack::ConditionalCleanup<T, As...> CleanupType;
    743     EHStack.pushCleanupTuple<CleanupType>(kind, Saved);
    744     initFullExprCleanup();
    745   }
    746 
    747   /// Queue a cleanup to be pushed after finishing the current full-expression,
    748   /// potentially with an active flag.
    749   template <class T, class... As>
    750   void pushCleanupAfterFullExpr(CleanupKind Kind, As... A) {
    751     if (!isInConditionalBranch())
    752       return pushCleanupAfterFullExprWithActiveFlag<T>(Kind, Address::invalid(),
    753                                                        A...);
    754 
    755     Address ActiveFlag = createCleanupActiveFlag();
    756     assert(!DominatingValue<Address>::needsSaving(ActiveFlag) &&
    757            "cleanup active flag should never need saving");
    758 
    759     typedef std::tuple<typename DominatingValue<As>::saved_type...> SavedTuple;
    760     SavedTuple Saved{saveValueInCond(A)...};
    761 
    762     typedef EHScopeStack::ConditionalCleanup<T, As...> CleanupType;
    763     pushCleanupAfterFullExprWithActiveFlag<CleanupType>(Kind, ActiveFlag, Saved);
    764   }
    765 
    766   template <class T, class... As>
    767   void pushCleanupAfterFullExprWithActiveFlag(CleanupKind Kind,
    768                                               Address ActiveFlag, As... A) {
    769     LifetimeExtendedCleanupHeader Header = {sizeof(T), Kind,
    770                                             ActiveFlag.isValid()};
    771 
    772     size_t OldSize = LifetimeExtendedCleanupStack.size();
    773     LifetimeExtendedCleanupStack.resize(
    774         LifetimeExtendedCleanupStack.size() + sizeof(Header) + Header.Size +
    775         (Header.IsConditional ? sizeof(ActiveFlag) : 0));
    776 
    777     static_assert(sizeof(Header) % alignof(T) == 0,
    778                   "Cleanup will be allocated on misaligned address");
    779     char *Buffer = &LifetimeExtendedCleanupStack[OldSize];
    780     new (Buffer) LifetimeExtendedCleanupHeader(Header);
    781     new (Buffer + sizeof(Header)) T(A...);
    782     if (Header.IsConditional)
    783       new (Buffer + sizeof(Header) + sizeof(T)) Address(ActiveFlag);
    784   }
    785 
    786   /// Set up the last cleanup that was pushed as a conditional
    787   /// full-expression cleanup.
    788   void initFullExprCleanup() {
    789     initFullExprCleanupWithFlag(createCleanupActiveFlag());
    790   }
    791 
    792   void initFullExprCleanupWithFlag(Address ActiveFlag);
    793   Address createCleanupActiveFlag();
    794 
    795   /// PushDestructorCleanup - Push a cleanup to call the
    796   /// complete-object destructor of an object of the given type at the
    797   /// given address.  Does nothing if T is not a C++ class type with a
    798   /// non-trivial destructor.
    799   void PushDestructorCleanup(QualType T, Address Addr);
    800 
    801   /// PushDestructorCleanup - Push a cleanup to call the
    802   /// complete-object variant of the given destructor on the object at
    803   /// the given address.
    804   void PushDestructorCleanup(const CXXDestructorDecl *Dtor, QualType T,
    805                              Address Addr);
    806 
    807   /// PopCleanupBlock - Will pop the cleanup entry on the stack and
    808   /// process all branch fixups.
    809   void PopCleanupBlock(bool FallThroughIsBranchThrough = false);
    810 
    811   /// DeactivateCleanupBlock - Deactivates the given cleanup block.
    812   /// The block cannot be reactivated.  Pops it if it's the top of the
    813   /// stack.
    814   ///
    815   /// \param DominatingIP - An instruction which is known to
    816   ///   dominate the current IP (if set) and which lies along
    817   ///   all paths of execution between the current IP and the
    818   ///   the point at which the cleanup comes into scope.
    819   void DeactivateCleanupBlock(EHScopeStack::stable_iterator Cleanup,
    820                               llvm::Instruction *DominatingIP);
    821 
    822   /// ActivateCleanupBlock - Activates an initially-inactive cleanup.
    823   /// Cannot be used to resurrect a deactivated cleanup.
    824   ///
    825   /// \param DominatingIP - An instruction which is known to
    826   ///   dominate the current IP (if set) and which lies along
    827   ///   all paths of execution between the current IP and the
    828   ///   the point at which the cleanup comes into scope.
    829   void ActivateCleanupBlock(EHScopeStack::stable_iterator Cleanup,
    830                             llvm::Instruction *DominatingIP);
    831 
    832   /// Enters a new scope for capturing cleanups, all of which
    833   /// will be executed once the scope is exited.
    834   class RunCleanupsScope {
    835     EHScopeStack::stable_iterator CleanupStackDepth, OldCleanupScopeDepth;
    836     size_t LifetimeExtendedCleanupStackSize;
    837     bool OldDidCallStackSave;
    838   protected:
    839     bool PerformCleanup;
    840   private:
    841 
    842     RunCleanupsScope(const RunCleanupsScope &) = delete;
    843     void operator=(const RunCleanupsScope &) = delete;
    844 
    845   protected:
    846     CodeGenFunction& CGF;
    847 
    848   public:
    849     /// Enter a new cleanup scope.
    850     explicit RunCleanupsScope(CodeGenFunction &CGF)
    851       : PerformCleanup(true), CGF(CGF)
    852     {
    853       CleanupStackDepth = CGF.EHStack.stable_begin();
    854       LifetimeExtendedCleanupStackSize =
    855           CGF.LifetimeExtendedCleanupStack.size();
    856       OldDidCallStackSave = CGF.DidCallStackSave;
    857       CGF.DidCallStackSave = false;
    858       OldCleanupScopeDepth = CGF.CurrentCleanupScopeDepth;
    859       CGF.CurrentCleanupScopeDepth = CleanupStackDepth;
    860     }
    861 
    862     /// Exit this cleanup scope, emitting any accumulated cleanups.
    863     ~RunCleanupsScope() {
    864       if (PerformCleanup)
    865         ForceCleanup();
    866     }
    867 
    868     /// Determine whether this scope requires any cleanups.
    869     bool requiresCleanups() const {
    870       return CGF.EHStack.stable_begin() != CleanupStackDepth;
    871     }
    872 
    873     /// Force the emission of cleanups now, instead of waiting
    874     /// until this object is destroyed.
    875     /// \param ValuesToReload - A list of values that need to be available at
    876     /// the insertion point after cleanup emission. If cleanup emission created
    877     /// a shared cleanup block, these value pointers will be rewritten.
    878     /// Otherwise, they not will be modified.
    879     void ForceCleanup(std::initializer_list<llvm::Value**> ValuesToReload = {}) {
    880       assert(PerformCleanup && "Already forced cleanup");
    881       CGF.DidCallStackSave = OldDidCallStackSave;
    882       CGF.PopCleanupBlocks(CleanupStackDepth, LifetimeExtendedCleanupStackSize,
    883                            ValuesToReload);
    884       PerformCleanup = false;
    885       CGF.CurrentCleanupScopeDepth = OldCleanupScopeDepth;
    886     }
    887   };
    888 
    889   // Cleanup stack depth of the RunCleanupsScope that was pushed most recently.
    890   EHScopeStack::stable_iterator CurrentCleanupScopeDepth =
    891       EHScopeStack::stable_end();
    892 
    893   class LexicalScope : public RunCleanupsScope {
    894     SourceRange Range;
    895     SmallVector<const LabelDecl*, 4> Labels;
    896     LexicalScope *ParentScope;
    897 
    898     LexicalScope(const LexicalScope &) = delete;
    899     void operator=(const LexicalScope &) = delete;
    900 
    901   public:
    902     /// Enter a new cleanup scope.
    903     explicit LexicalScope(CodeGenFunction &CGF, SourceRange Range)
    904       : RunCleanupsScope(CGF), Range(Range), ParentScope(CGF.CurLexicalScope) {
    905       CGF.CurLexicalScope = this;
    906       if (CGDebugInfo *DI = CGF.getDebugInfo())
    907         DI->EmitLexicalBlockStart(CGF.Builder, Range.getBegin());
    908     }
    909 
    910     void addLabel(const LabelDecl *label) {
    911       assert(PerformCleanup && "adding label to dead scope?");
    912       Labels.push_back(label);
    913     }
    914 
    915     /// Exit this cleanup scope, emitting any accumulated
    916     /// cleanups.
    917     ~LexicalScope() {
    918       if (CGDebugInfo *DI = CGF.getDebugInfo())
    919         DI->EmitLexicalBlockEnd(CGF.Builder, Range.getEnd());
    920 
    921       // If we should perform a cleanup, force them now.  Note that
    922       // this ends the cleanup scope before rescoping any labels.
    923       if (PerformCleanup) {
    924         ApplyDebugLocation DL(CGF, Range.getEnd());
    925         ForceCleanup();
    926       }
    927     }
    928 
    929     /// Force the emission of cleanups now, instead of waiting
    930     /// until this object is destroyed.
    931     void ForceCleanup() {
    932       CGF.CurLexicalScope = ParentScope;
    933       RunCleanupsScope::ForceCleanup();
    934 
    935       if (!Labels.empty())
    936         rescopeLabels();
    937     }
    938 
    939     bool hasLabels() const {
    940       return !Labels.empty();
    941     }
    942 
    943     void rescopeLabels();
    944   };
    945 
    946   typedef llvm::DenseMap<const Decl *, Address> DeclMapTy;
    947 
    948   /// The class used to assign some variables some temporarily addresses.
    949   class OMPMapVars {
    950     DeclMapTy SavedLocals;
    951     DeclMapTy SavedTempAddresses;
    952     OMPMapVars(const OMPMapVars &) = delete;
    953     void operator=(const OMPMapVars &) = delete;
    954 
    955   public:
    956     explicit OMPMapVars() = default;
    957     ~OMPMapVars() {
    958       assert(SavedLocals.empty() && "Did not restored original addresses.");
    959     };
    960 
    961     /// Sets the address of the variable \p LocalVD to be \p TempAddr in
    962     /// function \p CGF.
    963     /// \return true if at least one variable was set already, false otherwise.
    964     bool setVarAddr(CodeGenFunction &CGF, const VarDecl *LocalVD,
    965                     Address TempAddr) {
    966       LocalVD = LocalVD->getCanonicalDecl();
    967       // Only save it once.
    968       if (SavedLocals.count(LocalVD)) return false;
    969 
    970       // Copy the existing local entry to SavedLocals.
    971       auto it = CGF.LocalDeclMap.find(LocalVD);
    972       if (it != CGF.LocalDeclMap.end())
    973         SavedLocals.try_emplace(LocalVD, it->second);
    974       else
    975         SavedLocals.try_emplace(LocalVD, Address::invalid());
    976 
    977       // Generate the private entry.
    978       QualType VarTy = LocalVD->getType();
    979       if (VarTy->isReferenceType()) {
    980         Address Temp = CGF.CreateMemTemp(VarTy);
    981         CGF.Builder.CreateStore(TempAddr.getPointer(), Temp);
    982         TempAddr = Temp;
    983       }
    984       SavedTempAddresses.try_emplace(LocalVD, TempAddr);
    985 
    986       return true;
    987     }
    988 
    989     /// Applies new addresses to the list of the variables.
    990     /// \return true if at least one variable is using new address, false
    991     /// otherwise.
    992     bool apply(CodeGenFunction &CGF) {
    993       copyInto(SavedTempAddresses, CGF.LocalDeclMap);
    994       SavedTempAddresses.clear();
    995       return !SavedLocals.empty();
    996     }
    997 
    998     /// Restores original addresses of the variables.
    999     void restore(CodeGenFunction &CGF) {
   1000       if (!SavedLocals.empty()) {
   1001         copyInto(SavedLocals, CGF.LocalDeclMap);
   1002         SavedLocals.clear();
   1003       }
   1004     }
   1005 
   1006   private:
   1007     /// Copy all the entries in the source map over the corresponding
   1008     /// entries in the destination, which must exist.
   1009     static void copyInto(const DeclMapTy &Src, DeclMapTy &Dest) {
   1010       for (auto &Pair : Src) {
   1011         if (!Pair.second.isValid()) {
   1012           Dest.erase(Pair.first);
   1013           continue;
   1014         }
   1015 
   1016         auto I = Dest.find(Pair.first);
   1017         if (I != Dest.end())
   1018           I->second = Pair.second;
   1019         else
   1020           Dest.insert(Pair);
   1021       }
   1022     }
   1023   };
   1024 
   1025   /// The scope used to remap some variables as private in the OpenMP loop body
   1026   /// (or other captured region emitted without outlining), and to restore old
   1027   /// vars back on exit.
   1028   class OMPPrivateScope : public RunCleanupsScope {
   1029     OMPMapVars MappedVars;
   1030     OMPPrivateScope(const OMPPrivateScope &) = delete;
   1031     void operator=(const OMPPrivateScope &) = delete;
   1032 
   1033   public:
   1034     /// Enter a new OpenMP private scope.
   1035     explicit OMPPrivateScope(CodeGenFunction &CGF) : RunCleanupsScope(CGF) {}
   1036 
   1037     /// Registers \p LocalVD variable as a private and apply \p PrivateGen
   1038     /// function for it to generate corresponding private variable. \p
   1039     /// PrivateGen returns an address of the generated private variable.
   1040     /// \return true if the variable is registered as private, false if it has
   1041     /// been privatized already.
   1042     bool addPrivate(const VarDecl *LocalVD,
   1043                     const llvm::function_ref<Address()> PrivateGen) {
   1044       assert(PerformCleanup && "adding private to dead scope");
   1045       return MappedVars.setVarAddr(CGF, LocalVD, PrivateGen());
   1046     }
   1047 
   1048     /// Privatizes local variables previously registered as private.
   1049     /// Registration is separate from the actual privatization to allow
   1050     /// initializers use values of the original variables, not the private one.
   1051     /// This is important, for example, if the private variable is a class
   1052     /// variable initialized by a constructor that references other private
   1053     /// variables. But at initialization original variables must be used, not
   1054     /// private copies.
   1055     /// \return true if at least one variable was privatized, false otherwise.
   1056     bool Privatize() { return MappedVars.apply(CGF); }
   1057 
   1058     void ForceCleanup() {
   1059       RunCleanupsScope::ForceCleanup();
   1060       MappedVars.restore(CGF);
   1061     }
   1062 
   1063     /// Exit scope - all the mapped variables are restored.
   1064     ~OMPPrivateScope() {
   1065       if (PerformCleanup)
   1066         ForceCleanup();
   1067     }
   1068 
   1069     /// Checks if the global variable is captured in current function.
   1070     bool isGlobalVarCaptured(const VarDecl *VD) const {
   1071       VD = VD->getCanonicalDecl();
   1072       return !VD->isLocalVarDeclOrParm() && CGF.LocalDeclMap.count(VD) > 0;
   1073     }
   1074   };
   1075 
   1076   /// Save/restore original map of previously emitted local vars in case when we
   1077   /// need to duplicate emission of the same code several times in the same
   1078   /// function for OpenMP code.
   1079   class OMPLocalDeclMapRAII {
   1080     CodeGenFunction &CGF;
   1081     DeclMapTy SavedMap;
   1082 
   1083   public:
   1084     OMPLocalDeclMapRAII(CodeGenFunction &CGF)
   1085         : CGF(CGF), SavedMap(CGF.LocalDeclMap) {}
   1086     ~OMPLocalDeclMapRAII() { SavedMap.swap(CGF.LocalDeclMap); }
   1087   };
   1088 
   1089   /// Takes the old cleanup stack size and emits the cleanup blocks
   1090   /// that have been added.
   1091   void
   1092   PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize,
   1093                    std::initializer_list<llvm::Value **> ValuesToReload = {});
   1094 
   1095   /// Takes the old cleanup stack size and emits the cleanup blocks
   1096   /// that have been added, then adds all lifetime-extended cleanups from
   1097   /// the given position to the stack.
   1098   void
   1099   PopCleanupBlocks(EHScopeStack::stable_iterator OldCleanupStackSize,
   1100                    size_t OldLifetimeExtendedStackSize,
   1101                    std::initializer_list<llvm::Value **> ValuesToReload = {});
   1102 
   1103   void ResolveBranchFixups(llvm::BasicBlock *Target);
   1104 
   1105   /// The given basic block lies in the current EH scope, but may be a
   1106   /// target of a potentially scope-crossing jump; get a stable handle
   1107   /// to which we can perform this jump later.
   1108   JumpDest getJumpDestInCurrentScope(llvm::BasicBlock *Target) {
   1109     return JumpDest(Target,
   1110                     EHStack.getInnermostNormalCleanup(),
   1111                     NextCleanupDestIndex++);
   1112   }
   1113 
   1114   /// The given basic block lies in the current EH scope, but may be a
   1115   /// target of a potentially scope-crossing jump; get a stable handle
   1116   /// to which we can perform this jump later.
   1117   JumpDest getJumpDestInCurrentScope(StringRef Name = StringRef()) {
   1118     return getJumpDestInCurrentScope(createBasicBlock(Name));
   1119   }
   1120 
   1121   /// EmitBranchThroughCleanup - Emit a branch from the current insert
   1122   /// block through the normal cleanup handling code (if any) and then
   1123   /// on to \arg Dest.
   1124   void EmitBranchThroughCleanup(JumpDest Dest);
   1125 
   1126   /// isObviouslyBranchWithoutCleanups - Return true if a branch to the
   1127   /// specified destination obviously has no cleanups to run.  'false' is always
   1128   /// a conservatively correct answer for this method.
   1129   bool isObviouslyBranchWithoutCleanups(JumpDest Dest) const;
   1130 
   1131   /// popCatchScope - Pops the catch scope at the top of the EHScope
   1132   /// stack, emitting any required code (other than the catch handlers
   1133   /// themselves).
   1134   void popCatchScope();
   1135 
   1136   llvm::BasicBlock *getEHResumeBlock(bool isCleanup);
   1137   llvm::BasicBlock *getEHDispatchBlock(EHScopeStack::stable_iterator scope);
   1138   llvm::BasicBlock *
   1139   getFuncletEHDispatchBlock(EHScopeStack::stable_iterator scope);
   1140 
   1141   /// An object to manage conditionally-evaluated expressions.
   1142   class ConditionalEvaluation {
   1143     llvm::BasicBlock *StartBB;
   1144 
   1145   public:
   1146     ConditionalEvaluation(CodeGenFunction &CGF)
   1147       : StartBB(CGF.Builder.GetInsertBlock()) {}
   1148 
   1149     void begin(CodeGenFunction &CGF) {
   1150       assert(CGF.OutermostConditional != this);
   1151       if (!CGF.OutermostConditional)
   1152         CGF.OutermostConditional = this;
   1153     }
   1154 
   1155     void end(CodeGenFunction &CGF) {
   1156       assert(CGF.OutermostConditional != nullptr);
   1157       if (CGF.OutermostConditional == this)
   1158         CGF.OutermostConditional = nullptr;
   1159     }
   1160 
   1161     /// Returns a block which will be executed prior to each
   1162     /// evaluation of the conditional code.
   1163     llvm::BasicBlock *getStartingBlock() const {
   1164       return StartBB;
   1165     }
   1166   };
   1167 
   1168   /// isInConditionalBranch - Return true if we're currently emitting
   1169   /// one branch or the other of a conditional expression.
   1170   bool isInConditionalBranch() const { return OutermostConditional != nullptr; }
   1171 
   1172   void setBeforeOutermostConditional(llvm::Value *value, Address addr) {
   1173     assert(isInConditionalBranch());
   1174     llvm::BasicBlock *block = OutermostConditional->getStartingBlock();
   1175     auto store = new llvm::StoreInst(value, addr.getPointer(), &block->back());
   1176     store->setAlignment(addr.getAlignment().getAsAlign());
   1177   }
   1178 
   1179   /// An RAII object to record that we're evaluating a statement
   1180   /// expression.
   1181   class StmtExprEvaluation {
   1182     CodeGenFunction &CGF;
   1183 
   1184     /// We have to save the outermost conditional: cleanups in a
   1185     /// statement expression aren't conditional just because the
   1186     /// StmtExpr is.
   1187     ConditionalEvaluation *SavedOutermostConditional;
   1188 
   1189   public:
   1190     StmtExprEvaluation(CodeGenFunction &CGF)
   1191       : CGF(CGF), SavedOutermostConditional(CGF.OutermostConditional) {
   1192       CGF.OutermostConditional = nullptr;
   1193     }
   1194 
   1195     ~StmtExprEvaluation() {
   1196       CGF.OutermostConditional = SavedOutermostConditional;
   1197       CGF.EnsureInsertPoint();
   1198     }
   1199   };
   1200 
   1201   /// An object which temporarily prevents a value from being
   1202   /// destroyed by aggressive peephole optimizations that assume that
   1203   /// all uses of a value have been realized in the IR.
   1204   class PeepholeProtection {
   1205     llvm::Instruction *Inst;
   1206     friend class CodeGenFunction;
   1207 
   1208   public:
   1209     PeepholeProtection() : Inst(nullptr) {}
   1210   };
   1211 
   1212   /// A non-RAII class containing all the information about a bound
   1213   /// opaque value.  OpaqueValueMapping, below, is a RAII wrapper for
   1214   /// this which makes individual mappings very simple; using this
   1215   /// class directly is useful when you have a variable number of
   1216   /// opaque values or don't want the RAII functionality for some
   1217   /// reason.
   1218   class OpaqueValueMappingData {
   1219     const OpaqueValueExpr *OpaqueValue;
   1220     bool BoundLValue;
   1221     CodeGenFunction::PeepholeProtection Protection;
   1222 
   1223     OpaqueValueMappingData(const OpaqueValueExpr *ov,
   1224                            bool boundLValue)
   1225       : OpaqueValue(ov), BoundLValue(boundLValue) {}
   1226   public:
   1227     OpaqueValueMappingData() : OpaqueValue(nullptr) {}
   1228 
   1229     static bool shouldBindAsLValue(const Expr *expr) {
   1230       // gl-values should be bound as l-values for obvious reasons.
   1231       // Records should be bound as l-values because IR generation
   1232       // always keeps them in memory.  Expressions of function type
   1233       // act exactly like l-values but are formally required to be
   1234       // r-values in C.
   1235       return expr->isGLValue() ||
   1236              expr->getType()->isFunctionType() ||
   1237              hasAggregateEvaluationKind(expr->getType());
   1238     }
   1239 
   1240     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
   1241                                        const OpaqueValueExpr *ov,
   1242                                        const Expr *e) {
   1243       if (shouldBindAsLValue(ov))
   1244         return bind(CGF, ov, CGF.EmitLValue(e));
   1245       return bind(CGF, ov, CGF.EmitAnyExpr(e));
   1246     }
   1247 
   1248     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
   1249                                        const OpaqueValueExpr *ov,
   1250                                        const LValue &lv) {
   1251       assert(shouldBindAsLValue(ov));
   1252       CGF.OpaqueLValues.insert(std::make_pair(ov, lv));
   1253       return OpaqueValueMappingData(ov, true);
   1254     }
   1255 
   1256     static OpaqueValueMappingData bind(CodeGenFunction &CGF,
   1257                                        const OpaqueValueExpr *ov,
   1258                                        const RValue &rv) {
   1259       assert(!shouldBindAsLValue(ov));
   1260       CGF.OpaqueRValues.insert(std::make_pair(ov, rv));
   1261 
   1262       OpaqueValueMappingData data(ov, false);
   1263 
   1264       // Work around an extremely aggressive peephole optimization in
   1265       // EmitScalarConversion which assumes that all other uses of a
   1266       // value are extant.
   1267       data.Protection = CGF.protectFromPeepholes(rv);
   1268 
   1269       return data;
   1270     }
   1271 
   1272     bool isValid() const { return OpaqueValue != nullptr; }
   1273     void clear() { OpaqueValue = nullptr; }
   1274 
   1275     void unbind(CodeGenFunction &CGF) {
   1276       assert(OpaqueValue && "no data to unbind!");
   1277 
   1278       if (BoundLValue) {
   1279         CGF.OpaqueLValues.erase(OpaqueValue);
   1280       } else {
   1281         CGF.OpaqueRValues.erase(OpaqueValue);
   1282         CGF.unprotectFromPeepholes(Protection);
   1283       }
   1284     }
   1285   };
   1286 
   1287   /// An RAII object to set (and then clear) a mapping for an OpaqueValueExpr.
   1288   class OpaqueValueMapping {
   1289     CodeGenFunction &CGF;
   1290     OpaqueValueMappingData Data;
   1291 
   1292   public:
   1293     static bool shouldBindAsLValue(const Expr *expr) {
   1294       return OpaqueValueMappingData::shouldBindAsLValue(expr);
   1295     }
   1296 
   1297     /// Build the opaque value mapping for the given conditional
   1298     /// operator if it's the GNU ?: extension.  This is a common
   1299     /// enough pattern that the convenience operator is really
   1300     /// helpful.
   1301     ///
   1302     OpaqueValueMapping(CodeGenFunction &CGF,
   1303                        const AbstractConditionalOperator *op) : CGF(CGF) {
   1304       if (isa<ConditionalOperator>(op))
   1305         // Leave Data empty.
   1306         return;
   1307 
   1308       const BinaryConditionalOperator *e = cast<BinaryConditionalOperator>(op);
   1309       Data = OpaqueValueMappingData::bind(CGF, e->getOpaqueValue(),
   1310                                           e->getCommon());
   1311     }
   1312 
   1313     /// Build the opaque value mapping for an OpaqueValueExpr whose source
   1314     /// expression is set to the expression the OVE represents.
   1315     OpaqueValueMapping(CodeGenFunction &CGF, const OpaqueValueExpr *OV)
   1316         : CGF(CGF) {
   1317       if (OV) {
   1318         assert(OV->getSourceExpr() && "wrong form of OpaqueValueMapping used "
   1319                                       "for OVE with no source expression");
   1320         Data = OpaqueValueMappingData::bind(CGF, OV, OV->getSourceExpr());
   1321       }
   1322     }
   1323 
   1324     OpaqueValueMapping(CodeGenFunction &CGF,
   1325                        const OpaqueValueExpr *opaqueValue,
   1326                        LValue lvalue)
   1327       : CGF(CGF), Data(OpaqueValueMappingData::bind(CGF, opaqueValue, lvalue)) {
   1328     }
   1329 
   1330     OpaqueValueMapping(CodeGenFunction &CGF,
   1331                        const OpaqueValueExpr *opaqueValue,
   1332                        RValue rvalue)
   1333       : CGF(CGF), Data(OpaqueValueMappingData::bind(CGF, opaqueValue, rvalue)) {
   1334     }
   1335 
   1336     void pop() {
   1337       Data.unbind(CGF);
   1338       Data.clear();
   1339     }
   1340 
   1341     ~OpaqueValueMapping() {
   1342       if (Data.isValid()) Data.unbind(CGF);
   1343     }
   1344   };
   1345 
   1346 private:
   1347   CGDebugInfo *DebugInfo;
   1348   /// Used to create unique names for artificial VLA size debug info variables.
   1349   unsigned VLAExprCounter = 0;
   1350   bool DisableDebugInfo = false;
   1351 
   1352   /// DidCallStackSave - Whether llvm.stacksave has been called. Used to avoid
   1353   /// calling llvm.stacksave for multiple VLAs in the same scope.
   1354   bool DidCallStackSave = false;
   1355 
   1356   /// IndirectBranch - The first time an indirect goto is seen we create a block
   1357   /// with an indirect branch.  Every time we see the address of a label taken,
   1358   /// we add the label to the indirect goto.  Every subsequent indirect goto is
   1359   /// codegen'd as a jump to the IndirectBranch's basic block.
   1360   llvm::IndirectBrInst *IndirectBranch = nullptr;
   1361 
   1362   /// LocalDeclMap - This keeps track of the LLVM allocas or globals for local C
   1363   /// decls.
   1364   DeclMapTy LocalDeclMap;
   1365 
   1366   // Keep track of the cleanups for callee-destructed parameters pushed to the
   1367   // cleanup stack so that they can be deactivated later.
   1368   llvm::DenseMap<const ParmVarDecl *, EHScopeStack::stable_iterator>
   1369       CalleeDestructedParamCleanups;
   1370 
   1371   /// SizeArguments - If a ParmVarDecl had the pass_object_size attribute, this
   1372   /// will contain a mapping from said ParmVarDecl to its implicit "object_size"
   1373   /// parameter.
   1374   llvm::SmallDenseMap<const ParmVarDecl *, const ImplicitParamDecl *, 2>
   1375       SizeArguments;
   1376 
   1377   /// Track escaped local variables with auto storage. Used during SEH
   1378   /// outlining to produce a call to llvm.localescape.
   1379   llvm::DenseMap<llvm::AllocaInst *, int> EscapedLocals;
   1380 
   1381   /// LabelMap - This keeps track of the LLVM basic block for each C label.
   1382   llvm::DenseMap<const LabelDecl*, JumpDest> LabelMap;
   1383 
   1384   // BreakContinueStack - This keeps track of where break and continue
   1385   // statements should jump to.
   1386   struct BreakContinue {
   1387     BreakContinue(JumpDest Break, JumpDest Continue)
   1388       : BreakBlock(Break), ContinueBlock(Continue) {}
   1389 
   1390     JumpDest BreakBlock;
   1391     JumpDest ContinueBlock;
   1392   };
   1393   SmallVector<BreakContinue, 8> BreakContinueStack;
   1394 
   1395   /// Handles cancellation exit points in OpenMP-related constructs.
   1396   class OpenMPCancelExitStack {
   1397     /// Tracks cancellation exit point and join point for cancel-related exit
   1398     /// and normal exit.
   1399     struct CancelExit {
   1400       CancelExit() = default;
   1401       CancelExit(OpenMPDirectiveKind Kind, JumpDest ExitBlock,
   1402                  JumpDest ContBlock)
   1403           : Kind(Kind), ExitBlock(ExitBlock), ContBlock(ContBlock) {}
   1404       OpenMPDirectiveKind Kind = llvm::omp::OMPD_unknown;
   1405       /// true if the exit block has been emitted already by the special
   1406       /// emitExit() call, false if the default codegen is used.
   1407       bool HasBeenEmitted = false;
   1408       JumpDest ExitBlock;
   1409       JumpDest ContBlock;
   1410     };
   1411 
   1412     SmallVector<CancelExit, 8> Stack;
   1413 
   1414   public:
   1415     OpenMPCancelExitStack() : Stack(1) {}
   1416     ~OpenMPCancelExitStack() = default;
   1417     /// Fetches the exit block for the current OpenMP construct.
   1418     JumpDest getExitBlock() const { return Stack.back().ExitBlock; }
   1419     /// Emits exit block with special codegen procedure specific for the related
   1420     /// OpenMP construct + emits code for normal construct cleanup.
   1421     void emitExit(CodeGenFunction &CGF, OpenMPDirectiveKind Kind,
   1422                   const llvm::function_ref<void(CodeGenFunction &)> CodeGen) {
   1423       if (Stack.back().Kind == Kind && getExitBlock().isValid()) {
   1424         assert(CGF.getOMPCancelDestination(Kind).isValid());
   1425         assert(CGF.HaveInsertPoint());
   1426         assert(!Stack.back().HasBeenEmitted);
   1427         auto IP = CGF.Builder.saveAndClearIP();
   1428         CGF.EmitBlock(Stack.back().ExitBlock.getBlock());
   1429         CodeGen(CGF);
   1430         CGF.EmitBranch(Stack.back().ContBlock.getBlock());
   1431         CGF.Builder.restoreIP(IP);
   1432         Stack.back().HasBeenEmitted = true;
   1433       }
   1434       CodeGen(CGF);
   1435     }
   1436     /// Enter the cancel supporting \a Kind construct.
   1437     /// \param Kind OpenMP directive that supports cancel constructs.
   1438     /// \param HasCancel true, if the construct has inner cancel directive,
   1439     /// false otherwise.
   1440     void enter(CodeGenFunction &CGF, OpenMPDirectiveKind Kind, bool HasCancel) {
   1441       Stack.push_back({Kind,
   1442                        HasCancel ? CGF.getJumpDestInCurrentScope("cancel.exit")
   1443                                  : JumpDest(),
   1444                        HasCancel ? CGF.getJumpDestInCurrentScope("cancel.cont")
   1445                                  : JumpDest()});
   1446     }
   1447     /// Emits default exit point for the cancel construct (if the special one
   1448     /// has not be used) + join point for cancel/normal exits.
   1449     void exit(CodeGenFunction &CGF) {
   1450       if (getExitBlock().isValid()) {
   1451         assert(CGF.getOMPCancelDestination(Stack.back().Kind).isValid());
   1452         bool HaveIP = CGF.HaveInsertPoint();
   1453         if (!Stack.back().HasBeenEmitted) {
   1454           if (HaveIP)
   1455             CGF.EmitBranchThroughCleanup(Stack.back().ContBlock);
   1456           CGF.EmitBlock(Stack.back().ExitBlock.getBlock());
   1457           CGF.EmitBranchThroughCleanup(Stack.back().ContBlock);
   1458         }
   1459         CGF.EmitBlock(Stack.back().ContBlock.getBlock());
   1460         if (!HaveIP) {
   1461           CGF.Builder.CreateUnreachable();
   1462           CGF.Builder.ClearInsertionPoint();
   1463         }
   1464       }
   1465       Stack.pop_back();
   1466     }
   1467   };
   1468   OpenMPCancelExitStack OMPCancelStack;
   1469 
   1470   /// Lower the Likelihood knowledge about the \p Cond via llvm.expect intrin.
   1471   llvm::Value *emitCondLikelihoodViaExpectIntrinsic(llvm::Value *Cond,
   1472                                                     Stmt::Likelihood LH);
   1473 
   1474   CodeGenPGO PGO;
   1475 
   1476   /// Calculate branch weights appropriate for PGO data
   1477   llvm::MDNode *createProfileWeights(uint64_t TrueCount,
   1478                                      uint64_t FalseCount) const;
   1479   llvm::MDNode *createProfileWeights(ArrayRef<uint64_t> Weights) const;
   1480   llvm::MDNode *createProfileWeightsForLoop(const Stmt *Cond,
   1481                                             uint64_t LoopCount) const;
   1482 
   1483 public:
   1484   /// Increment the profiler's counter for the given statement by \p StepV.
   1485   /// If \p StepV is null, the default increment is 1.
   1486   void incrementProfileCounter(const Stmt *S, llvm::Value *StepV = nullptr) {
   1487     if (CGM.getCodeGenOpts().hasProfileClangInstr() &&
   1488         !CurFn->hasFnAttribute(llvm::Attribute::NoProfile))
   1489       PGO.emitCounterIncrement(Builder, S, StepV);
   1490     PGO.setCurrentStmt(S);
   1491   }
   1492 
   1493   /// Get the profiler's count for the given statement.
   1494   uint64_t getProfileCount(const Stmt *S) {
   1495     Optional<uint64_t> Count = PGO.getStmtCount(S);
   1496     if (!Count.hasValue())
   1497       return 0;
   1498     return *Count;
   1499   }
   1500 
   1501   /// Set the profiler's current count.
   1502   void setCurrentProfileCount(uint64_t Count) {
   1503     PGO.setCurrentRegionCount(Count);
   1504   }
   1505 
   1506   /// Get the profiler's current count. This is generally the count for the most
   1507   /// recently incremented counter.
   1508   uint64_t getCurrentProfileCount() {
   1509     return PGO.getCurrentRegionCount();
   1510   }
   1511 
   1512 private:
   1513 
   1514   /// SwitchInsn - This is nearest current switch instruction. It is null if
   1515   /// current context is not in a switch.
   1516   llvm::SwitchInst *SwitchInsn = nullptr;
   1517   /// The branch weights of SwitchInsn when doing instrumentation based PGO.
   1518   SmallVector<uint64_t, 16> *SwitchWeights = nullptr;
   1519 
   1520   /// The likelihood attributes of the SwitchCase.
   1521   SmallVector<Stmt::Likelihood, 16> *SwitchLikelihood = nullptr;
   1522 
   1523   /// CaseRangeBlock - This block holds if condition check for last case
   1524   /// statement range in current switch instruction.
   1525   llvm::BasicBlock *CaseRangeBlock = nullptr;
   1526 
   1527   /// OpaqueLValues - Keeps track of the current set of opaque value
   1528   /// expressions.
   1529   llvm::DenseMap<const OpaqueValueExpr *, LValue> OpaqueLValues;
   1530   llvm::DenseMap<const OpaqueValueExpr *, RValue> OpaqueRValues;
   1531 
   1532   // VLASizeMap - This keeps track of the associated size for each VLA type.
   1533   // We track this by the size expression rather than the type itself because
   1534   // in certain situations, like a const qualifier applied to an VLA typedef,
   1535   // multiple VLA types can share the same size expression.
   1536   // FIXME: Maybe this could be a stack of maps that is pushed/popped as we
   1537   // enter/leave scopes.
   1538   llvm::DenseMap<const Expr*, llvm::Value*> VLASizeMap;
   1539 
   1540   /// A block containing a single 'unreachable' instruction.  Created
   1541   /// lazily by getUnreachableBlock().
   1542   llvm::BasicBlock *UnreachableBlock = nullptr;
   1543 
   1544   /// Counts of the number return expressions in the function.
   1545   unsigned NumReturnExprs = 0;
   1546 
   1547   /// Count the number of simple (constant) return expressions in the function.
   1548   unsigned NumSimpleReturnExprs = 0;
   1549 
   1550   /// The last regular (non-return) debug location (breakpoint) in the function.
   1551   SourceLocation LastStopPoint;
   1552 
   1553 public:
   1554   /// Source location information about the default argument or member
   1555   /// initializer expression we're evaluating, if any.
   1556   CurrentSourceLocExprScope CurSourceLocExprScope;
   1557   using SourceLocExprScopeGuard =
   1558       CurrentSourceLocExprScope::SourceLocExprScopeGuard;
   1559 
   1560   /// A scope within which we are constructing the fields of an object which
   1561   /// might use a CXXDefaultInitExpr. This stashes away a 'this' value to use
   1562   /// if we need to evaluate a CXXDefaultInitExpr within the evaluation.
   1563   class FieldConstructionScope {
   1564   public:
   1565     FieldConstructionScope(CodeGenFunction &CGF, Address This)
   1566         : CGF(CGF), OldCXXDefaultInitExprThis(CGF.CXXDefaultInitExprThis) {
   1567       CGF.CXXDefaultInitExprThis = This;
   1568     }
   1569     ~FieldConstructionScope() {
   1570       CGF.CXXDefaultInitExprThis = OldCXXDefaultInitExprThis;
   1571     }
   1572 
   1573   private:
   1574     CodeGenFunction &CGF;
   1575     Address OldCXXDefaultInitExprThis;
   1576   };
   1577 
   1578   /// The scope of a CXXDefaultInitExpr. Within this scope, the value of 'this'
   1579   /// is overridden to be the object under construction.
   1580   class CXXDefaultInitExprScope  {
   1581   public:
   1582     CXXDefaultInitExprScope(CodeGenFunction &CGF, const CXXDefaultInitExpr *E)
   1583         : CGF(CGF), OldCXXThisValue(CGF.CXXThisValue),
   1584           OldCXXThisAlignment(CGF.CXXThisAlignment),
   1585           SourceLocScope(E, CGF.CurSourceLocExprScope) {
   1586       CGF.CXXThisValue = CGF.CXXDefaultInitExprThis.getPointer();
   1587       CGF.CXXThisAlignment = CGF.CXXDefaultInitExprThis.getAlignment();
   1588     }
   1589     ~CXXDefaultInitExprScope() {
   1590       CGF.CXXThisValue = OldCXXThisValue;
   1591       CGF.CXXThisAlignment = OldCXXThisAlignment;
   1592     }
   1593 
   1594   public:
   1595     CodeGenFunction &CGF;
   1596     llvm::Value *OldCXXThisValue;
   1597     CharUnits OldCXXThisAlignment;
   1598     SourceLocExprScopeGuard SourceLocScope;
   1599   };
   1600 
   1601   struct CXXDefaultArgExprScope : SourceLocExprScopeGuard {
   1602     CXXDefaultArgExprScope(CodeGenFunction &CGF, const CXXDefaultArgExpr *E)
   1603         : SourceLocExprScopeGuard(E, CGF.CurSourceLocExprScope) {}
   1604   };
   1605 
   1606   /// The scope of an ArrayInitLoopExpr. Within this scope, the value of the
   1607   /// current loop index is overridden.
   1608   class ArrayInitLoopExprScope {
   1609   public:
   1610     ArrayInitLoopExprScope(CodeGenFunction &CGF, llvm::Value *Index)
   1611       : CGF(CGF), OldArrayInitIndex(CGF.ArrayInitIndex) {
   1612       CGF.ArrayInitIndex = Index;
   1613     }
   1614     ~ArrayInitLoopExprScope() {
   1615       CGF.ArrayInitIndex = OldArrayInitIndex;
   1616     }
   1617 
   1618   private:
   1619     CodeGenFunction &CGF;
   1620     llvm::Value *OldArrayInitIndex;
   1621   };
   1622 
   1623   class InlinedInheritingConstructorScope {
   1624   public:
   1625     InlinedInheritingConstructorScope(CodeGenFunction &CGF, GlobalDecl GD)
   1626         : CGF(CGF), OldCurGD(CGF.CurGD), OldCurFuncDecl(CGF.CurFuncDecl),
   1627           OldCurCodeDecl(CGF.CurCodeDecl),
   1628           OldCXXABIThisDecl(CGF.CXXABIThisDecl),
   1629           OldCXXABIThisValue(CGF.CXXABIThisValue),
   1630           OldCXXThisValue(CGF.CXXThisValue),
   1631           OldCXXABIThisAlignment(CGF.CXXABIThisAlignment),
   1632           OldCXXThisAlignment(CGF.CXXThisAlignment),
   1633           OldReturnValue(CGF.ReturnValue), OldFnRetTy(CGF.FnRetTy),
   1634           OldCXXInheritedCtorInitExprArgs(
   1635               std::move(CGF.CXXInheritedCtorInitExprArgs)) {
   1636       CGF.CurGD = GD;
   1637       CGF.CurFuncDecl = CGF.CurCodeDecl =
   1638           cast<CXXConstructorDecl>(GD.getDecl());
   1639       CGF.CXXABIThisDecl = nullptr;
   1640       CGF.CXXABIThisValue = nullptr;
   1641       CGF.CXXThisValue = nullptr;
   1642       CGF.CXXABIThisAlignment = CharUnits();
   1643       CGF.CXXThisAlignment = CharUnits();
   1644       CGF.ReturnValue = Address::invalid();
   1645       CGF.FnRetTy = QualType();
   1646       CGF.CXXInheritedCtorInitExprArgs.clear();
   1647     }
   1648     ~InlinedInheritingConstructorScope() {
   1649       CGF.CurGD = OldCurGD;
   1650       CGF.CurFuncDecl = OldCurFuncDecl;
   1651       CGF.CurCodeDecl = OldCurCodeDecl;
   1652       CGF.CXXABIThisDecl = OldCXXABIThisDecl;
   1653       CGF.CXXABIThisValue = OldCXXABIThisValue;
   1654       CGF.CXXThisValue = OldCXXThisValue;
   1655       CGF.CXXABIThisAlignment = OldCXXABIThisAlignment;
   1656       CGF.CXXThisAlignment = OldCXXThisAlignment;
   1657       CGF.ReturnValue = OldReturnValue;
   1658       CGF.FnRetTy = OldFnRetTy;
   1659       CGF.CXXInheritedCtorInitExprArgs =
   1660           std::move(OldCXXInheritedCtorInitExprArgs);
   1661     }
   1662 
   1663   private:
   1664     CodeGenFunction &CGF;
   1665     GlobalDecl OldCurGD;
   1666     const Decl *OldCurFuncDecl;
   1667     const Decl *OldCurCodeDecl;
   1668     ImplicitParamDecl *OldCXXABIThisDecl;
   1669     llvm::Value *OldCXXABIThisValue;
   1670     llvm::Value *OldCXXThisValue;
   1671     CharUnits OldCXXABIThisAlignment;
   1672     CharUnits OldCXXThisAlignment;
   1673     Address OldReturnValue;
   1674     QualType OldFnRetTy;
   1675     CallArgList OldCXXInheritedCtorInitExprArgs;
   1676   };
   1677 
   1678   // Helper class for the OpenMP IR Builder. Allows reusability of code used for
   1679   // region body, and finalization codegen callbacks. This will class will also
   1680   // contain privatization functions used by the privatization call backs
   1681   //
   1682   // TODO: this is temporary class for things that are being moved out of
   1683   // CGOpenMPRuntime, new versions of current CodeGenFunction methods, or
   1684   // utility function for use with the OMPBuilder. Once that move to use the
   1685   // OMPBuilder is done, everything here will either become part of CodeGenFunc.
   1686   // directly, or a new helper class that will contain functions used by both
   1687   // this and the OMPBuilder
   1688 
   1689   struct OMPBuilderCBHelpers {
   1690 
   1691     OMPBuilderCBHelpers() = delete;
   1692     OMPBuilderCBHelpers(const OMPBuilderCBHelpers &) = delete;
   1693     OMPBuilderCBHelpers &operator=(const OMPBuilderCBHelpers &) = delete;
   1694 
   1695     using InsertPointTy = llvm::OpenMPIRBuilder::InsertPointTy;
   1696 
   1697     /// Cleanup action for allocate support.
   1698     class OMPAllocateCleanupTy final : public EHScopeStack::Cleanup {
   1699 
   1700     private:
   1701       llvm::CallInst *RTLFnCI;
   1702 
   1703     public:
   1704       OMPAllocateCleanupTy(llvm::CallInst *RLFnCI) : RTLFnCI(RLFnCI) {
   1705         RLFnCI->removeFromParent();
   1706       }
   1707 
   1708       void Emit(CodeGenFunction &CGF, Flags /*flags*/) override {
   1709         if (!CGF.HaveInsertPoint())
   1710           return;
   1711         CGF.Builder.Insert(RTLFnCI);
   1712       }
   1713     };
   1714 
   1715     /// Returns address of the threadprivate variable for the current
   1716     /// thread. This Also create any necessary OMP runtime calls.
   1717     ///
   1718     /// \param VD VarDecl for Threadprivate variable.
   1719     /// \param VDAddr Address of the Vardecl
   1720     /// \param Loc  The location where the barrier directive was encountered
   1721     static Address getAddrOfThreadPrivate(CodeGenFunction &CGF,
   1722                                           const VarDecl *VD, Address VDAddr,
   1723                                           SourceLocation Loc);
   1724 
   1725     /// Gets the OpenMP-specific address of the local variable /p VD.
   1726     static Address getAddressOfLocalVariable(CodeGenFunction &CGF,
   1727                                              const VarDecl *VD);
   1728     /// Get the platform-specific name separator.
   1729     /// \param Parts different parts of the final name that needs separation
   1730     /// \param FirstSeparator First separator used between the initial two
   1731     ///        parts of the name.
   1732     /// \param Separator separator used between all of the rest consecutinve
   1733     ///        parts of the name
   1734     static std::string getNameWithSeparators(ArrayRef<StringRef> Parts,
   1735                                              StringRef FirstSeparator = ".",
   1736                                              StringRef Separator = ".");
   1737     /// Emit the Finalization for an OMP region
   1738     /// \param CGF	The Codegen function this belongs to
   1739     /// \param IP	Insertion point for generating the finalization code.
   1740     static void FinalizeOMPRegion(CodeGenFunction &CGF, InsertPointTy IP) {
   1741       CGBuilderTy::InsertPointGuard IPG(CGF.Builder);
   1742       assert(IP.getBlock()->end() != IP.getPoint() &&
   1743              "OpenMP IR Builder should cause terminated block!");
   1744 
   1745       llvm::BasicBlock *IPBB = IP.getBlock();
   1746       llvm::BasicBlock *DestBB = IPBB->getUniqueSuccessor();
   1747       assert(DestBB && "Finalization block should have one successor!");
   1748 
   1749       // erase and replace with cleanup branch.
   1750       IPBB->getTerminator()->eraseFromParent();
   1751       CGF.Builder.SetInsertPoint(IPBB);
   1752       CodeGenFunction::JumpDest Dest = CGF.getJumpDestInCurrentScope(DestBB);
   1753       CGF.EmitBranchThroughCleanup(Dest);
   1754     }
   1755 
   1756     /// Emit the body of an OMP region
   1757     /// \param CGF	The Codegen function this belongs to
   1758     /// \param RegionBodyStmt	The body statement for the OpenMP region being
   1759     /// 			 generated
   1760     /// \param CodeGenIP	Insertion point for generating the body code.
   1761     /// \param FiniBB	The finalization basic block
   1762     static void EmitOMPRegionBody(CodeGenFunction &CGF,
   1763                                   const Stmt *RegionBodyStmt,
   1764                                   InsertPointTy CodeGenIP,
   1765                                   llvm::BasicBlock &FiniBB) {
   1766       llvm::BasicBlock *CodeGenIPBB = CodeGenIP.getBlock();
   1767       if (llvm::Instruction *CodeGenIPBBTI = CodeGenIPBB->getTerminator())
   1768         CodeGenIPBBTI->eraseFromParent();
   1769 
   1770       CGF.Builder.SetInsertPoint(CodeGenIPBB);
   1771 
   1772       CGF.EmitStmt(RegionBodyStmt);
   1773 
   1774       if (CGF.Builder.saveIP().isSet())
   1775         CGF.Builder.CreateBr(&FiniBB);
   1776     }
   1777 
   1778     /// RAII for preserving necessary info during Outlined region body codegen.
   1779     class OutlinedRegionBodyRAII {
   1780 
   1781       llvm::AssertingVH<llvm::Instruction> OldAllocaIP;
   1782       CodeGenFunction::JumpDest OldReturnBlock;
   1783       CGBuilderTy::InsertPoint IP;
   1784       CodeGenFunction &CGF;
   1785 
   1786     public:
   1787       OutlinedRegionBodyRAII(CodeGenFunction &cgf, InsertPointTy &AllocaIP,
   1788                              llvm::BasicBlock &RetBB)
   1789           : CGF(cgf) {
   1790         assert(AllocaIP.isSet() &&
   1791                "Must specify Insertion point for allocas of outlined function");
   1792         OldAllocaIP = CGF.AllocaInsertPt;
   1793         CGF.AllocaInsertPt = &*AllocaIP.getPoint();
   1794         IP = CGF.Builder.saveIP();
   1795 
   1796         OldReturnBlock = CGF.ReturnBlock;
   1797         CGF.ReturnBlock = CGF.getJumpDestInCurrentScope(&RetBB);
   1798       }
   1799 
   1800       ~OutlinedRegionBodyRAII() {
   1801         CGF.AllocaInsertPt = OldAllocaIP;
   1802         CGF.ReturnBlock = OldReturnBlock;
   1803         CGF.Builder.restoreIP(IP);
   1804       }
   1805     };
   1806 
   1807     /// RAII for preserving necessary info during inlined region body codegen.
   1808     class InlinedRegionBodyRAII {
   1809 
   1810       llvm::AssertingVH<llvm::Instruction> OldAllocaIP;
   1811       CodeGenFunction &CGF;
   1812 
   1813     public:
   1814       InlinedRegionBodyRAII(CodeGenFunction &cgf, InsertPointTy &AllocaIP,
   1815                             llvm::BasicBlock &FiniBB)
   1816           : CGF(cgf) {
   1817         // Alloca insertion block should be in the entry block of the containing
   1818         // function so it expects an empty AllocaIP in which case will reuse the
   1819         // old alloca insertion point, or a new AllocaIP in the same block as
   1820         // the old one
   1821         assert((!AllocaIP.isSet() ||
   1822                 CGF.AllocaInsertPt->getParent() == AllocaIP.getBlock()) &&
   1823                "Insertion point should be in the entry block of containing "
   1824                "function!");
   1825         OldAllocaIP = CGF.AllocaInsertPt;
   1826         if (AllocaIP.isSet())
   1827           CGF.AllocaInsertPt = &*AllocaIP.getPoint();
   1828 
   1829         // TODO: Remove the call, after making sure the counter is not used by
   1830         //       the EHStack.
   1831         // Since this is an inlined region, it should not modify the
   1832         // ReturnBlock, and should reuse the one for the enclosing outlined
   1833         // region. So, the JumpDest being return by the function is discarded
   1834         (void)CGF.getJumpDestInCurrentScope(&FiniBB);
   1835       }
   1836 
   1837       ~InlinedRegionBodyRAII() { CGF.AllocaInsertPt = OldAllocaIP; }
   1838     };
   1839   };
   1840 
   1841 private:
   1842   /// CXXThisDecl - When generating code for a C++ member function,
   1843   /// this will hold the implicit 'this' declaration.
   1844   ImplicitParamDecl *CXXABIThisDecl = nullptr;
   1845   llvm::Value *CXXABIThisValue = nullptr;
   1846   llvm::Value *CXXThisValue = nullptr;
   1847   CharUnits CXXABIThisAlignment;
   1848   CharUnits CXXThisAlignment;
   1849 
   1850   /// The value of 'this' to use when evaluating CXXDefaultInitExprs within
   1851   /// this expression.
   1852   Address CXXDefaultInitExprThis = Address::invalid();
   1853 
   1854   /// The current array initialization index when evaluating an
   1855   /// ArrayInitIndexExpr within an ArrayInitLoopExpr.
   1856   llvm::Value *ArrayInitIndex = nullptr;
   1857 
   1858   /// The values of function arguments to use when evaluating
   1859   /// CXXInheritedCtorInitExprs within this context.
   1860   CallArgList CXXInheritedCtorInitExprArgs;
   1861 
   1862   /// CXXStructorImplicitParamDecl - When generating code for a constructor or
   1863   /// destructor, this will hold the implicit argument (e.g. VTT).
   1864   ImplicitParamDecl *CXXStructorImplicitParamDecl = nullptr;
   1865   llvm::Value *CXXStructorImplicitParamValue = nullptr;
   1866 
   1867   /// OutermostConditional - Points to the outermost active
   1868   /// conditional control.  This is used so that we know if a
   1869   /// temporary should be destroyed conditionally.
   1870   ConditionalEvaluation *OutermostConditional = nullptr;
   1871 
   1872   /// The current lexical scope.
   1873   LexicalScope *CurLexicalScope = nullptr;
   1874 
   1875   /// The current source location that should be used for exception
   1876   /// handling code.
   1877   SourceLocation CurEHLocation;
   1878 
   1879   /// BlockByrefInfos - For each __block variable, contains
   1880   /// information about the layout of the variable.
   1881   llvm::DenseMap<const ValueDecl *, BlockByrefInfo> BlockByrefInfos;
   1882 
   1883   /// Used by -fsanitize=nullability-return to determine whether the return
   1884   /// value can be checked.
   1885   llvm::Value *RetValNullabilityPrecondition = nullptr;
   1886 
   1887   /// Check if -fsanitize=nullability-return instrumentation is required for
   1888   /// this function.
   1889   bool requiresReturnValueNullabilityCheck() const {
   1890     return RetValNullabilityPrecondition;
   1891   }
   1892 
   1893   /// Used to store precise source locations for return statements by the
   1894   /// runtime return value checks.
   1895   Address ReturnLocation = Address::invalid();
   1896 
   1897   /// Check if the return value of this function requires sanitization.
   1898   bool requiresReturnValueCheck() const;
   1899 
   1900   llvm::BasicBlock *TerminateLandingPad = nullptr;
   1901   llvm::BasicBlock *TerminateHandler = nullptr;
   1902   llvm::SmallVector<llvm::BasicBlock *, 2> TrapBBs;
   1903 
   1904   /// Terminate funclets keyed by parent funclet pad.
   1905   llvm::MapVector<llvm::Value *, llvm::BasicBlock *> TerminateFunclets;
   1906 
   1907   /// Largest vector width used in ths function. Will be used to create a
   1908   /// function attribute.
   1909   unsigned LargestVectorWidth = 0;
   1910 
   1911   /// True if we need emit the life-time markers. This is initially set in
   1912   /// the constructor, but could be overwritten to true if this is a coroutine.
   1913   bool ShouldEmitLifetimeMarkers;
   1914 
   1915   /// Add OpenCL kernel arg metadata and the kernel attribute metadata to
   1916   /// the function metadata.
   1917   void EmitOpenCLKernelMetadata(const FunctionDecl *FD,
   1918                                 llvm::Function *Fn);
   1919 
   1920 public:
   1921   CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext=false);
   1922   ~CodeGenFunction();
   1923 
   1924   CodeGenTypes &getTypes() const { return CGM.getTypes(); }
   1925   ASTContext &getContext() const { return CGM.getContext(); }
   1926   CGDebugInfo *getDebugInfo() {
   1927     if (DisableDebugInfo)
   1928       return nullptr;
   1929     return DebugInfo;
   1930   }
   1931   void disableDebugInfo() { DisableDebugInfo = true; }
   1932   void enableDebugInfo() { DisableDebugInfo = false; }
   1933 
   1934   bool shouldUseFusedARCCalls() {
   1935     return CGM.getCodeGenOpts().OptimizationLevel == 0;
   1936   }
   1937 
   1938   const LangOptions &getLangOpts() const { return CGM.getLangOpts(); }
   1939 
   1940   /// Returns a pointer to the function's exception object and selector slot,
   1941   /// which is assigned in every landing pad.
   1942   Address getExceptionSlot();
   1943   Address getEHSelectorSlot();
   1944 
   1945   /// Returns the contents of the function's exception object and selector
   1946   /// slots.
   1947   llvm::Value *getExceptionFromSlot();
   1948   llvm::Value *getSelectorFromSlot();
   1949 
   1950   Address getNormalCleanupDestSlot();
   1951 
   1952   llvm::BasicBlock *getUnreachableBlock() {
   1953     if (!UnreachableBlock) {
   1954       UnreachableBlock = createBasicBlock("unreachable");
   1955       new llvm::UnreachableInst(getLLVMContext(), UnreachableBlock);
   1956     }
   1957     return UnreachableBlock;
   1958   }
   1959 
   1960   llvm::BasicBlock *getInvokeDest() {
   1961     if (!EHStack.requiresLandingPad()) return nullptr;
   1962     return getInvokeDestImpl();
   1963   }
   1964 
   1965   bool currentFunctionUsesSEHTry() const { return CurSEHParent != nullptr; }
   1966 
   1967   const TargetInfo &getTarget() const { return Target; }
   1968   llvm::LLVMContext &getLLVMContext() { return CGM.getLLVMContext(); }
   1969   const TargetCodeGenInfo &getTargetHooks() const {
   1970     return CGM.getTargetCodeGenInfo();
   1971   }
   1972 
   1973   //===--------------------------------------------------------------------===//
   1974   //                                  Cleanups
   1975   //===--------------------------------------------------------------------===//
   1976 
   1977   typedef void Destroyer(CodeGenFunction &CGF, Address addr, QualType ty);
   1978 
   1979   void pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin,
   1980                                         Address arrayEndPointer,
   1981                                         QualType elementType,
   1982                                         CharUnits elementAlignment,
   1983                                         Destroyer *destroyer);
   1984   void pushRegularPartialArrayCleanup(llvm::Value *arrayBegin,
   1985                                       llvm::Value *arrayEnd,
   1986                                       QualType elementType,
   1987                                       CharUnits elementAlignment,
   1988                                       Destroyer *destroyer);
   1989 
   1990   void pushDestroy(QualType::DestructionKind dtorKind,
   1991                    Address addr, QualType type);
   1992   void pushEHDestroy(QualType::DestructionKind dtorKind,
   1993                      Address addr, QualType type);
   1994   void pushDestroy(CleanupKind kind, Address addr, QualType type,
   1995                    Destroyer *destroyer, bool useEHCleanupForArray);
   1996   void pushLifetimeExtendedDestroy(CleanupKind kind, Address addr,
   1997                                    QualType type, Destroyer *destroyer,
   1998                                    bool useEHCleanupForArray);
   1999   void pushCallObjectDeleteCleanup(const FunctionDecl *OperatorDelete,
   2000                                    llvm::Value *CompletePtr,
   2001                                    QualType ElementType);
   2002   void pushStackRestore(CleanupKind kind, Address SPMem);
   2003   void emitDestroy(Address addr, QualType type, Destroyer *destroyer,
   2004                    bool useEHCleanupForArray);
   2005   llvm::Function *generateDestroyHelper(Address addr, QualType type,
   2006                                         Destroyer *destroyer,
   2007                                         bool useEHCleanupForArray,
   2008                                         const VarDecl *VD);
   2009   void emitArrayDestroy(llvm::Value *begin, llvm::Value *end,
   2010                         QualType elementType, CharUnits elementAlign,
   2011                         Destroyer *destroyer,
   2012                         bool checkZeroLength, bool useEHCleanup);
   2013 
   2014   Destroyer *getDestroyer(QualType::DestructionKind destructionKind);
   2015 
   2016   /// Determines whether an EH cleanup is required to destroy a type
   2017   /// with the given destruction kind.
   2018   bool needsEHCleanup(QualType::DestructionKind kind) {
   2019     switch (kind) {
   2020     case QualType::DK_none:
   2021       return false;
   2022     case QualType::DK_cxx_destructor:
   2023     case QualType::DK_objc_weak_lifetime:
   2024     case QualType::DK_nontrivial_c_struct:
   2025       return getLangOpts().Exceptions;
   2026     case QualType::DK_objc_strong_lifetime:
   2027       return getLangOpts().Exceptions &&
   2028              CGM.getCodeGenOpts().ObjCAutoRefCountExceptions;
   2029     }
   2030     llvm_unreachable("bad destruction kind");
   2031   }
   2032 
   2033   CleanupKind getCleanupKind(QualType::DestructionKind kind) {
   2034     return (needsEHCleanup(kind) ? NormalAndEHCleanup : NormalCleanup);
   2035   }
   2036 
   2037   //===--------------------------------------------------------------------===//
   2038   //                                  Objective-C
   2039   //===--------------------------------------------------------------------===//
   2040 
   2041   void GenerateObjCMethod(const ObjCMethodDecl *OMD);
   2042 
   2043   void StartObjCMethod(const ObjCMethodDecl *MD, const ObjCContainerDecl *CD);
   2044 
   2045   /// GenerateObjCGetter - Synthesize an Objective-C property getter function.
   2046   void GenerateObjCGetter(ObjCImplementationDecl *IMP,
   2047                           const ObjCPropertyImplDecl *PID);
   2048   void generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
   2049                               const ObjCPropertyImplDecl *propImpl,
   2050                               const ObjCMethodDecl *GetterMothodDecl,
   2051                               llvm::Constant *AtomicHelperFn);
   2052 
   2053   void GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP,
   2054                                   ObjCMethodDecl *MD, bool ctor);
   2055 
   2056   /// GenerateObjCSetter - Synthesize an Objective-C property setter function
   2057   /// for the given property.
   2058   void GenerateObjCSetter(ObjCImplementationDecl *IMP,
   2059                           const ObjCPropertyImplDecl *PID);
   2060   void generateObjCSetterBody(const ObjCImplementationDecl *classImpl,
   2061                               const ObjCPropertyImplDecl *propImpl,
   2062                               llvm::Constant *AtomicHelperFn);
   2063 
   2064   //===--------------------------------------------------------------------===//
   2065   //                                  Block Bits
   2066   //===--------------------------------------------------------------------===//
   2067 
   2068   /// Emit block literal.
   2069   /// \return an LLVM value which is a pointer to a struct which contains
   2070   /// information about the block, including the block invoke function, the
   2071   /// captured variables, etc.
   2072   llvm::Value *EmitBlockLiteral(const BlockExpr *);
   2073 
   2074   llvm::Function *GenerateBlockFunction(GlobalDecl GD,
   2075                                         const CGBlockInfo &Info,
   2076                                         const DeclMapTy &ldm,
   2077                                         bool IsLambdaConversionToBlock,
   2078                                         bool BuildGlobalBlock);
   2079 
   2080   /// Check if \p T is a C++ class that has a destructor that can throw.
   2081   static bool cxxDestructorCanThrow(QualType T);
   2082 
   2083   llvm::Constant *GenerateCopyHelperFunction(const CGBlockInfo &blockInfo);
   2084   llvm::Constant *GenerateDestroyHelperFunction(const CGBlockInfo &blockInfo);
   2085   llvm::Constant *GenerateObjCAtomicSetterCopyHelperFunction(
   2086                                              const ObjCPropertyImplDecl *PID);
   2087   llvm::Constant *GenerateObjCAtomicGetterCopyHelperFunction(
   2088                                              const ObjCPropertyImplDecl *PID);
   2089   llvm::Value *EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty);
   2090 
   2091   void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags,
   2092                          bool CanThrow);
   2093 
   2094   class AutoVarEmission;
   2095 
   2096   void emitByrefStructureInit(const AutoVarEmission &emission);
   2097 
   2098   /// Enter a cleanup to destroy a __block variable.  Note that this
   2099   /// cleanup should be a no-op if the variable hasn't left the stack
   2100   /// yet; if a cleanup is required for the variable itself, that needs
   2101   /// to be done externally.
   2102   ///
   2103   /// \param Kind Cleanup kind.
   2104   ///
   2105   /// \param Addr When \p LoadBlockVarAddr is false, the address of the __block
   2106   /// structure that will be passed to _Block_object_dispose. When
   2107   /// \p LoadBlockVarAddr is true, the address of the field of the block
   2108   /// structure that holds the address of the __block structure.
   2109   ///
   2110   /// \param Flags The flag that will be passed to _Block_object_dispose.
   2111   ///
   2112   /// \param LoadBlockVarAddr Indicates whether we need to emit a load from
   2113   /// \p Addr to get the address of the __block structure.
   2114   void enterByrefCleanup(CleanupKind Kind, Address Addr, BlockFieldFlags Flags,
   2115                          bool LoadBlockVarAddr, bool CanThrow);
   2116 
   2117   void setBlockContextParameter(const ImplicitParamDecl *D, unsigned argNum,
   2118                                 llvm::Value *ptr);
   2119 
   2120   Address LoadBlockStruct();
   2121   Address GetAddrOfBlockDecl(const VarDecl *var);
   2122 
   2123   /// BuildBlockByrefAddress - Computes the location of the
   2124   /// data in a variable which is declared as __block.
   2125   Address emitBlockByrefAddress(Address baseAddr, const VarDecl *V,
   2126                                 bool followForward = true);
   2127   Address emitBlockByrefAddress(Address baseAddr,
   2128                                 const BlockByrefInfo &info,
   2129                                 bool followForward,
   2130                                 const llvm::Twine &name);
   2131 
   2132   const BlockByrefInfo &getBlockByrefInfo(const VarDecl *var);
   2133 
   2134   QualType BuildFunctionArgList(GlobalDecl GD, FunctionArgList &Args);
   2135 
   2136   void GenerateCode(GlobalDecl GD, llvm::Function *Fn,
   2137                     const CGFunctionInfo &FnInfo);
   2138 
   2139   /// Annotate the function with an attribute that disables TSan checking at
   2140   /// runtime.
   2141   void markAsIgnoreThreadCheckingAtRuntime(llvm::Function *Fn);
   2142 
   2143   /// Emit code for the start of a function.
   2144   /// \param Loc       The location to be associated with the function.
   2145   /// \param StartLoc  The location of the function body.
   2146   void StartFunction(GlobalDecl GD,
   2147                      QualType RetTy,
   2148                      llvm::Function *Fn,
   2149                      const CGFunctionInfo &FnInfo,
   2150                      const FunctionArgList &Args,
   2151                      SourceLocation Loc = SourceLocation(),
   2152                      SourceLocation StartLoc = SourceLocation());
   2153 
   2154   static bool IsConstructorDelegationValid(const CXXConstructorDecl *Ctor);
   2155 
   2156   void EmitConstructorBody(FunctionArgList &Args);
   2157   void EmitDestructorBody(FunctionArgList &Args);
   2158   void emitImplicitAssignmentOperatorBody(FunctionArgList &Args);
   2159   void EmitFunctionBody(const Stmt *Body);
   2160   void EmitBlockWithFallThrough(llvm::BasicBlock *BB, const Stmt *S);
   2161 
   2162   void EmitForwardingCallToLambda(const CXXMethodDecl *LambdaCallOperator,
   2163                                   CallArgList &CallArgs);
   2164   void EmitLambdaBlockInvokeBody();
   2165   void EmitLambdaDelegatingInvokeBody(const CXXMethodDecl *MD);
   2166   void EmitLambdaStaticInvokeBody(const CXXMethodDecl *MD);
   2167   void EmitLambdaVLACapture(const VariableArrayType *VAT, LValue LV) {
   2168     EmitStoreThroughLValue(RValue::get(VLASizeMap[VAT->getSizeExpr()]), LV);
   2169   }
   2170   void EmitAsanPrologueOrEpilogue(bool Prologue);
   2171 
   2172   /// Emit the unified return block, trying to avoid its emission when
   2173   /// possible.
   2174   /// \return The debug location of the user written return statement if the
   2175   /// return block is is avoided.
   2176   llvm::DebugLoc EmitReturnBlock();
   2177 
   2178   /// FinishFunction - Complete IR generation of the current function. It is
   2179   /// legal to call this function even if there is no current insertion point.
   2180   void FinishFunction(SourceLocation EndLoc=SourceLocation());
   2181 
   2182   void StartThunk(llvm::Function *Fn, GlobalDecl GD,
   2183                   const CGFunctionInfo &FnInfo, bool IsUnprototyped);
   2184 
   2185   void EmitCallAndReturnForThunk(llvm::FunctionCallee Callee,
   2186                                  const ThunkInfo *Thunk, bool IsUnprototyped);
   2187 
   2188   void FinishThunk();
   2189 
   2190   /// Emit a musttail call for a thunk with a potentially adjusted this pointer.
   2191   void EmitMustTailThunk(GlobalDecl GD, llvm::Value *AdjustedThisPtr,
   2192                          llvm::FunctionCallee Callee);
   2193 
   2194   /// Generate a thunk for the given method.
   2195   void generateThunk(llvm::Function *Fn, const CGFunctionInfo &FnInfo,
   2196                      GlobalDecl GD, const ThunkInfo &Thunk,
   2197                      bool IsUnprototyped);
   2198 
   2199   llvm::Function *GenerateVarArgsThunk(llvm::Function *Fn,
   2200                                        const CGFunctionInfo &FnInfo,
   2201                                        GlobalDecl GD, const ThunkInfo &Thunk);
   2202 
   2203   void EmitCtorPrologue(const CXXConstructorDecl *CD, CXXCtorType Type,
   2204                         FunctionArgList &Args);
   2205 
   2206   void EmitInitializerForField(FieldDecl *Field, LValue LHS, Expr *Init);
   2207 
   2208   /// Struct with all information about dynamic [sub]class needed to set vptr.
   2209   struct VPtr {
   2210     BaseSubobject Base;
   2211     const CXXRecordDecl *NearestVBase;
   2212     CharUnits OffsetFromNearestVBase;
   2213     const CXXRecordDecl *VTableClass;
   2214   };
   2215 
   2216   /// Initialize the vtable pointer of the given subobject.
   2217   void InitializeVTablePointer(const VPtr &vptr);
   2218 
   2219   typedef llvm::SmallVector<VPtr, 4> VPtrsVector;
   2220 
   2221   typedef llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBasesSetTy;
   2222   VPtrsVector getVTablePointers(const CXXRecordDecl *VTableClass);
   2223 
   2224   void getVTablePointers(BaseSubobject Base, const CXXRecordDecl *NearestVBase,
   2225                          CharUnits OffsetFromNearestVBase,
   2226                          bool BaseIsNonVirtualPrimaryBase,
   2227                          const CXXRecordDecl *VTableClass,
   2228                          VisitedVirtualBasesSetTy &VBases, VPtrsVector &vptrs);
   2229 
   2230   void InitializeVTablePointers(const CXXRecordDecl *ClassDecl);
   2231 
   2232   /// GetVTablePtr - Return the Value of the vtable pointer member pointed
   2233   /// to by This.
   2234   llvm::Value *GetVTablePtr(Address This, llvm::Type *VTableTy,
   2235                             const CXXRecordDecl *VTableClass);
   2236 
   2237   enum CFITypeCheckKind {
   2238     CFITCK_VCall,
   2239     CFITCK_NVCall,
   2240     CFITCK_DerivedCast,
   2241     CFITCK_UnrelatedCast,
   2242     CFITCK_ICall,
   2243     CFITCK_NVMFCall,
   2244     CFITCK_VMFCall,
   2245   };
   2246 
   2247   /// Derived is the presumed address of an object of type T after a
   2248   /// cast. If T is a polymorphic class type, emit a check that the virtual
   2249   /// table for Derived belongs to a class derived from T.
   2250   void EmitVTablePtrCheckForCast(QualType T, llvm::Value *Derived,
   2251                                  bool MayBeNull, CFITypeCheckKind TCK,
   2252                                  SourceLocation Loc);
   2253 
   2254   /// EmitVTablePtrCheckForCall - Virtual method MD is being called via VTable.
   2255   /// If vptr CFI is enabled, emit a check that VTable is valid.
   2256   void EmitVTablePtrCheckForCall(const CXXRecordDecl *RD, llvm::Value *VTable,
   2257                                  CFITypeCheckKind TCK, SourceLocation Loc);
   2258 
   2259   /// EmitVTablePtrCheck - Emit a check that VTable is a valid virtual table for
   2260   /// RD using llvm.type.test.
   2261   void EmitVTablePtrCheck(const CXXRecordDecl *RD, llvm::Value *VTable,
   2262                           CFITypeCheckKind TCK, SourceLocation Loc);
   2263 
   2264   /// If whole-program virtual table optimization is enabled, emit an assumption
   2265   /// that VTable is a member of RD's type identifier. Or, if vptr CFI is
   2266   /// enabled, emit a check that VTable is a member of RD's type identifier.
   2267   void EmitTypeMetadataCodeForVCall(const CXXRecordDecl *RD,
   2268                                     llvm::Value *VTable, SourceLocation Loc);
   2269 
   2270   /// Returns whether we should perform a type checked load when loading a
   2271   /// virtual function for virtual calls to members of RD. This is generally
   2272   /// true when both vcall CFI and whole-program-vtables are enabled.
   2273   bool ShouldEmitVTableTypeCheckedLoad(const CXXRecordDecl *RD);
   2274 
   2275   /// Emit a type checked load from the given vtable.
   2276   llvm::Value *EmitVTableTypeCheckedLoad(const CXXRecordDecl *RD, llvm::Value *VTable,
   2277                                          uint64_t VTableByteOffset);
   2278 
   2279   /// EnterDtorCleanups - Enter the cleanups necessary to complete the
   2280   /// given phase of destruction for a destructor.  The end result
   2281   /// should call destructors on members and base classes in reverse
   2282   /// order of their construction.
   2283   void EnterDtorCleanups(const CXXDestructorDecl *Dtor, CXXDtorType Type);
   2284 
   2285   /// ShouldInstrumentFunction - Return true if the current function should be
   2286   /// instrumented with __cyg_profile_func_* calls
   2287   bool ShouldInstrumentFunction();
   2288 
   2289   /// ShouldXRayInstrument - Return true if the current function should be
   2290   /// instrumented with XRay nop sleds.
   2291   bool ShouldXRayInstrumentFunction() const;
   2292 
   2293   /// AlwaysEmitXRayCustomEvents - Return true if we must unconditionally emit
   2294   /// XRay custom event handling calls.
   2295   bool AlwaysEmitXRayCustomEvents() const;
   2296 
   2297   /// AlwaysEmitXRayTypedEvents - Return true if clang must unconditionally emit
   2298   /// XRay typed event handling calls.
   2299   bool AlwaysEmitXRayTypedEvents() const;
   2300 
   2301   /// Encode an address into a form suitable for use in a function prologue.
   2302   llvm::Constant *EncodeAddrForUseInPrologue(llvm::Function *F,
   2303                                              llvm::Constant *Addr);
   2304 
   2305   /// Decode an address used in a function prologue, encoded by \c
   2306   /// EncodeAddrForUseInPrologue.
   2307   llvm::Value *DecodeAddrUsedInPrologue(llvm::Value *F,
   2308                                         llvm::Value *EncodedAddr);
   2309 
   2310   /// EmitFunctionProlog - Emit the target specific LLVM code to load the
   2311   /// arguments for the given function. This is also responsible for naming the
   2312   /// LLVM function arguments.
   2313   void EmitFunctionProlog(const CGFunctionInfo &FI,
   2314                           llvm::Function *Fn,
   2315                           const FunctionArgList &Args);
   2316 
   2317   /// EmitFunctionEpilog - Emit the target specific LLVM code to return the
   2318   /// given temporary.
   2319   void EmitFunctionEpilog(const CGFunctionInfo &FI, bool EmitRetDbgLoc,
   2320                           SourceLocation EndLoc);
   2321 
   2322   /// Emit a test that checks if the return value \p RV is nonnull.
   2323   void EmitReturnValueCheck(llvm::Value *RV);
   2324 
   2325   /// EmitStartEHSpec - Emit the start of the exception spec.
   2326   void EmitStartEHSpec(const Decl *D);
   2327 
   2328   /// EmitEndEHSpec - Emit the end of the exception spec.
   2329   void EmitEndEHSpec(const Decl *D);
   2330 
   2331   /// getTerminateLandingPad - Return a landing pad that just calls terminate.
   2332   llvm::BasicBlock *getTerminateLandingPad();
   2333 
   2334   /// getTerminateLandingPad - Return a cleanup funclet that just calls
   2335   /// terminate.
   2336   llvm::BasicBlock *getTerminateFunclet();
   2337 
   2338   /// getTerminateHandler - Return a handler (not a landing pad, just
   2339   /// a catch handler) that just calls terminate.  This is used when
   2340   /// a terminate scope encloses a try.
   2341   llvm::BasicBlock *getTerminateHandler();
   2342 
   2343   llvm::Type *ConvertTypeForMem(QualType T);
   2344   llvm::Type *ConvertType(QualType T);
   2345   llvm::Type *ConvertType(const TypeDecl *T) {
   2346     return ConvertType(getContext().getTypeDeclType(T));
   2347   }
   2348 
   2349   /// LoadObjCSelf - Load the value of self. This function is only valid while
   2350   /// generating code for an Objective-C method.
   2351   llvm::Value *LoadObjCSelf();
   2352 
   2353   /// TypeOfSelfObject - Return type of object that this self represents.
   2354   QualType TypeOfSelfObject();
   2355 
   2356   /// getEvaluationKind - Return the TypeEvaluationKind of QualType \c T.
   2357   static TypeEvaluationKind getEvaluationKind(QualType T);
   2358 
   2359   static bool hasScalarEvaluationKind(QualType T) {
   2360     return getEvaluationKind(T) == TEK_Scalar;
   2361   }
   2362 
   2363   static bool hasAggregateEvaluationKind(QualType T) {
   2364     return getEvaluationKind(T) == TEK_Aggregate;
   2365   }
   2366 
   2367   /// createBasicBlock - Create an LLVM basic block.
   2368   llvm::BasicBlock *createBasicBlock(const Twine &name = "",
   2369                                      llvm::Function *parent = nullptr,
   2370                                      llvm::BasicBlock *before = nullptr) {
   2371     return llvm::BasicBlock::Create(getLLVMContext(), name, parent, before);
   2372   }
   2373 
   2374   /// getBasicBlockForLabel - Return the LLVM basicblock that the specified
   2375   /// label maps to.
   2376   JumpDest getJumpDestForLabel(const LabelDecl *S);
   2377 
   2378   /// SimplifyForwardingBlocks - If the given basic block is only a branch to
   2379   /// another basic block, simplify it. This assumes that no other code could
   2380   /// potentially reference the basic block.
   2381   void SimplifyForwardingBlocks(llvm::BasicBlock *BB);
   2382 
   2383   /// EmitBlock - Emit the given block \arg BB and set it as the insert point,
   2384   /// adding a fall-through branch from the current insert block if
   2385   /// necessary. It is legal to call this function even if there is no current
   2386   /// insertion point.
   2387   ///
   2388   /// IsFinished - If true, indicates that the caller has finished emitting
   2389   /// branches to the given block and does not expect to emit code into it. This
   2390   /// means the block can be ignored if it is unreachable.
   2391   void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false);
   2392 
   2393   /// EmitBlockAfterUses - Emit the given block somewhere hopefully
   2394   /// near its uses, and leave the insertion point in it.
   2395   void EmitBlockAfterUses(llvm::BasicBlock *BB);
   2396 
   2397   /// EmitBranch - Emit a branch to the specified basic block from the current
   2398   /// insert block, taking care to avoid creation of branches from dummy
   2399   /// blocks. It is legal to call this function even if there is no current
   2400   /// insertion point.
   2401   ///
   2402   /// This function clears the current insertion point. The caller should follow
   2403   /// calls to this function with calls to Emit*Block prior to generation new
   2404   /// code.
   2405   void EmitBranch(llvm::BasicBlock *Block);
   2406 
   2407   /// HaveInsertPoint - True if an insertion point is defined. If not, this
   2408   /// indicates that the current code being emitted is unreachable.
   2409   bool HaveInsertPoint() const {
   2410     return Builder.GetInsertBlock() != nullptr;
   2411   }
   2412 
   2413   /// EnsureInsertPoint - Ensure that an insertion point is defined so that
   2414   /// emitted IR has a place to go. Note that by definition, if this function
   2415   /// creates a block then that block is unreachable; callers may do better to
   2416   /// detect when no insertion point is defined and simply skip IR generation.
   2417   void EnsureInsertPoint() {
   2418     if (!HaveInsertPoint())
   2419       EmitBlock(createBasicBlock());
   2420   }
   2421 
   2422   /// ErrorUnsupported - Print out an error that codegen doesn't support the
   2423   /// specified stmt yet.
   2424   void ErrorUnsupported(const Stmt *S, const char *Type);
   2425 
   2426   //===--------------------------------------------------------------------===//
   2427   //                                  Helpers
   2428   //===--------------------------------------------------------------------===//
   2429 
   2430   LValue MakeAddrLValue(Address Addr, QualType T,
   2431                         AlignmentSource Source = AlignmentSource::Type) {
   2432     return LValue::MakeAddr(Addr, T, getContext(), LValueBaseInfo(Source),
   2433                             CGM.getTBAAAccessInfo(T));
   2434   }
   2435 
   2436   LValue MakeAddrLValue(Address Addr, QualType T, LValueBaseInfo BaseInfo,
   2437                         TBAAAccessInfo TBAAInfo) {
   2438     return LValue::MakeAddr(Addr, T, getContext(), BaseInfo, TBAAInfo);
   2439   }
   2440 
   2441   LValue MakeAddrLValue(llvm::Value *V, QualType T, CharUnits Alignment,
   2442                         AlignmentSource Source = AlignmentSource::Type) {
   2443     return LValue::MakeAddr(Address(V, Alignment), T, getContext(),
   2444                             LValueBaseInfo(Source), CGM.getTBAAAccessInfo(T));
   2445   }
   2446 
   2447   LValue MakeAddrLValue(llvm::Value *V, QualType T, CharUnits Alignment,
   2448                         LValueBaseInfo BaseInfo, TBAAAccessInfo TBAAInfo) {
   2449     return LValue::MakeAddr(Address(V, Alignment), T, getContext(),
   2450                             BaseInfo, TBAAInfo);
   2451   }
   2452 
   2453   LValue MakeNaturalAlignPointeeAddrLValue(llvm::Value *V, QualType T);
   2454   LValue MakeNaturalAlignAddrLValue(llvm::Value *V, QualType T);
   2455 
   2456   Address EmitLoadOfReference(LValue RefLVal,
   2457                               LValueBaseInfo *PointeeBaseInfo = nullptr,
   2458                               TBAAAccessInfo *PointeeTBAAInfo = nullptr);
   2459   LValue EmitLoadOfReferenceLValue(LValue RefLVal);
   2460   LValue EmitLoadOfReferenceLValue(Address RefAddr, QualType RefTy,
   2461                                    AlignmentSource Source =
   2462                                        AlignmentSource::Type) {
   2463     LValue RefLVal = MakeAddrLValue(RefAddr, RefTy, LValueBaseInfo(Source),
   2464                                     CGM.getTBAAAccessInfo(RefTy));
   2465     return EmitLoadOfReferenceLValue(RefLVal);
   2466   }
   2467 
   2468   Address EmitLoadOfPointer(Address Ptr, const PointerType *PtrTy,
   2469                             LValueBaseInfo *BaseInfo = nullptr,
   2470                             TBAAAccessInfo *TBAAInfo = nullptr);
   2471   LValue EmitLoadOfPointerLValue(Address Ptr, const PointerType *PtrTy);
   2472 
   2473   /// CreateTempAlloca - This creates an alloca and inserts it into the entry
   2474   /// block if \p ArraySize is nullptr, otherwise inserts it at the current
   2475   /// insertion point of the builder. The caller is responsible for setting an
   2476   /// appropriate alignment on
   2477   /// the alloca.
   2478   ///
   2479   /// \p ArraySize is the number of array elements to be allocated if it
   2480   ///    is not nullptr.
   2481   ///
   2482   /// LangAS::Default is the address space of pointers to local variables and
   2483   /// temporaries, as exposed in the source language. In certain
   2484   /// configurations, this is not the same as the alloca address space, and a
   2485   /// cast is needed to lift the pointer from the alloca AS into
   2486   /// LangAS::Default. This can happen when the target uses a restricted
   2487   /// address space for the stack but the source language requires
   2488   /// LangAS::Default to be a generic address space. The latter condition is
   2489   /// common for most programming languages; OpenCL is an exception in that
   2490   /// LangAS::Default is the private address space, which naturally maps
   2491   /// to the stack.
   2492   ///
   2493   /// Because the address of a temporary is often exposed to the program in
   2494   /// various ways, this function will perform the cast. The original alloca
   2495   /// instruction is returned through \p Alloca if it is not nullptr.
   2496   ///
   2497   /// The cast is not performaed in CreateTempAllocaWithoutCast. This is
   2498   /// more efficient if the caller knows that the address will not be exposed.
   2499   llvm::AllocaInst *CreateTempAlloca(llvm::Type *Ty, const Twine &Name = "tmp",
   2500                                      llvm::Value *ArraySize = nullptr);
   2501   Address CreateTempAlloca(llvm::Type *Ty, CharUnits align,
   2502                            const Twine &Name = "tmp",
   2503                            llvm::Value *ArraySize = nullptr,
   2504                            Address *Alloca = nullptr);
   2505   Address CreateTempAllocaWithoutCast(llvm::Type *Ty, CharUnits align,
   2506                                       const Twine &Name = "tmp",
   2507                                       llvm::Value *ArraySize = nullptr);
   2508 
   2509   /// CreateDefaultAlignedTempAlloca - This creates an alloca with the
   2510   /// default ABI alignment of the given LLVM type.
   2511   ///
   2512   /// IMPORTANT NOTE: This is *not* generally the right alignment for
   2513   /// any given AST type that happens to have been lowered to the
   2514   /// given IR type.  This should only ever be used for function-local,
   2515   /// IR-driven manipulations like saving and restoring a value.  Do
   2516   /// not hand this address off to arbitrary IRGen routines, and especially
   2517   /// do not pass it as an argument to a function that might expect a
   2518   /// properly ABI-aligned value.
   2519   Address CreateDefaultAlignTempAlloca(llvm::Type *Ty,
   2520                                        const Twine &Name = "tmp");
   2521 
   2522   /// InitTempAlloca - Provide an initial value for the given alloca which
   2523   /// will be observable at all locations in the function.
   2524   ///
   2525   /// The address should be something that was returned from one of
   2526   /// the CreateTempAlloca or CreateMemTemp routines, and the
   2527   /// initializer must be valid in the entry block (i.e. it must
   2528   /// either be a constant or an argument value).
   2529   void InitTempAlloca(Address Alloca, llvm::Value *Value);
   2530 
   2531   /// CreateIRTemp - Create a temporary IR object of the given type, with
   2532   /// appropriate alignment. This routine should only be used when an temporary
   2533   /// value needs to be stored into an alloca (for example, to avoid explicit
   2534   /// PHI construction), but the type is the IR type, not the type appropriate
   2535   /// for storing in memory.
   2536   ///
   2537   /// That is, this is exactly equivalent to CreateMemTemp, but calling
   2538   /// ConvertType instead of ConvertTypeForMem.
   2539   Address CreateIRTemp(QualType T, const Twine &Name = "tmp");
   2540 
   2541   /// CreateMemTemp - Create a temporary memory object of the given type, with
   2542   /// appropriate alignmen and cast it to the default address space. Returns
   2543   /// the original alloca instruction by \p Alloca if it is not nullptr.
   2544   Address CreateMemTemp(QualType T, const Twine &Name = "tmp",
   2545                         Address *Alloca = nullptr);
   2546   Address CreateMemTemp(QualType T, CharUnits Align, const Twine &Name = "tmp",
   2547                         Address *Alloca = nullptr);
   2548 
   2549   /// CreateMemTemp - Create a temporary memory object of the given type, with
   2550   /// appropriate alignmen without casting it to the default address space.
   2551   Address CreateMemTempWithoutCast(QualType T, const Twine &Name = "tmp");
   2552   Address CreateMemTempWithoutCast(QualType T, CharUnits Align,
   2553                                    const Twine &Name = "tmp");
   2554 
   2555   /// CreateAggTemp - Create a temporary memory object for the given
   2556   /// aggregate type.
   2557   AggValueSlot CreateAggTemp(QualType T, const Twine &Name = "tmp",
   2558                              Address *Alloca = nullptr) {
   2559     return AggValueSlot::forAddr(CreateMemTemp(T, Name, Alloca),
   2560                                  T.getQualifiers(),
   2561                                  AggValueSlot::IsNotDestructed,
   2562                                  AggValueSlot::DoesNotNeedGCBarriers,
   2563                                  AggValueSlot::IsNotAliased,
   2564                                  AggValueSlot::DoesNotOverlap);
   2565   }
   2566 
   2567   /// Emit a cast to void* in the appropriate address space.
   2568   llvm::Value *EmitCastToVoidPtr(llvm::Value *value);
   2569 
   2570   /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
   2571   /// expression and compare the result against zero, returning an Int1Ty value.
   2572   llvm::Value *EvaluateExprAsBool(const Expr *E);
   2573 
   2574   /// EmitIgnoredExpr - Emit an expression in a context which ignores the result.
   2575   void EmitIgnoredExpr(const Expr *E);
   2576 
   2577   /// EmitAnyExpr - Emit code to compute the specified expression which can have
   2578   /// any type.  The result is returned as an RValue struct.  If this is an
   2579   /// aggregate expression, the aggloc/agglocvolatile arguments indicate where
   2580   /// the result should be returned.
   2581   ///
   2582   /// \param ignoreResult True if the resulting value isn't used.
   2583   RValue EmitAnyExpr(const Expr *E,
   2584                      AggValueSlot aggSlot = AggValueSlot::ignored(),
   2585                      bool ignoreResult = false);
   2586 
   2587   // EmitVAListRef - Emit a "reference" to a va_list; this is either the address
   2588   // or the value of the expression, depending on how va_list is defined.
   2589   Address EmitVAListRef(const Expr *E);
   2590 
   2591   /// Emit a "reference" to a __builtin_ms_va_list; this is
   2592   /// always the value of the expression, because a __builtin_ms_va_list is a
   2593   /// pointer to a char.
   2594   Address EmitMSVAListRef(const Expr *E);
   2595 
   2596   /// EmitAnyExprToTemp - Similarly to EmitAnyExpr(), however, the result will
   2597   /// always be accessible even if no aggregate location is provided.
   2598   RValue EmitAnyExprToTemp(const Expr *E);
   2599 
   2600   /// EmitAnyExprToMem - Emits the code necessary to evaluate an
   2601   /// arbitrary expression into the given memory location.
   2602   void EmitAnyExprToMem(const Expr *E, Address Location,
   2603                         Qualifiers Quals, bool IsInitializer);
   2604 
   2605   void EmitAnyExprToExn(const Expr *E, Address Addr);
   2606 
   2607   /// EmitExprAsInit - Emits the code necessary to initialize a
   2608   /// location in memory with the given initializer.
   2609   void EmitExprAsInit(const Expr *init, const ValueDecl *D, LValue lvalue,
   2610                       bool capturedByInit);
   2611 
   2612   /// hasVolatileMember - returns true if aggregate type has a volatile
   2613   /// member.
   2614   bool hasVolatileMember(QualType T) {
   2615     if (const RecordType *RT = T->getAs<RecordType>()) {
   2616       const RecordDecl *RD = cast<RecordDecl>(RT->getDecl());
   2617       return RD->hasVolatileMember();
   2618     }
   2619     return false;
   2620   }
   2621 
   2622   /// Determine whether a return value slot may overlap some other object.
   2623   AggValueSlot::Overlap_t getOverlapForReturnValue() {
   2624     // FIXME: Assuming no overlap here breaks guaranteed copy elision for base
   2625     // class subobjects. These cases may need to be revisited depending on the
   2626     // resolution of the relevant core issue.
   2627     return AggValueSlot::DoesNotOverlap;
   2628   }
   2629 
   2630   /// Determine whether a field initialization may overlap some other object.
   2631   AggValueSlot::Overlap_t getOverlapForFieldInit(const FieldDecl *FD);
   2632 
   2633   /// Determine whether a base class initialization may overlap some other
   2634   /// object.
   2635   AggValueSlot::Overlap_t getOverlapForBaseInit(const CXXRecordDecl *RD,
   2636                                                 const CXXRecordDecl *BaseRD,
   2637                                                 bool IsVirtual);
   2638 
   2639   /// Emit an aggregate assignment.
   2640   void EmitAggregateAssign(LValue Dest, LValue Src, QualType EltTy) {
   2641     bool IsVolatile = hasVolatileMember(EltTy);
   2642     EmitAggregateCopy(Dest, Src, EltTy, AggValueSlot::MayOverlap, IsVolatile);
   2643   }
   2644 
   2645   void EmitAggregateCopyCtor(LValue Dest, LValue Src,
   2646                              AggValueSlot::Overlap_t MayOverlap) {
   2647     EmitAggregateCopy(Dest, Src, Src.getType(), MayOverlap);
   2648   }
   2649 
   2650   /// EmitAggregateCopy - Emit an aggregate copy.
   2651   ///
   2652   /// \param isVolatile \c true iff either the source or the destination is
   2653   ///        volatile.
   2654   /// \param MayOverlap Whether the tail padding of the destination might be
   2655   ///        occupied by some other object. More efficient code can often be
   2656   ///        generated if not.
   2657   void EmitAggregateCopy(LValue Dest, LValue Src, QualType EltTy,
   2658                          AggValueSlot::Overlap_t MayOverlap,
   2659                          bool isVolatile = false);
   2660 
   2661   /// GetAddrOfLocalVar - Return the address of a local variable.
   2662   Address GetAddrOfLocalVar(const VarDecl *VD) {
   2663     auto it = LocalDeclMap.find(VD);
   2664     assert(it != LocalDeclMap.end() &&
   2665            "Invalid argument to GetAddrOfLocalVar(), no decl!");
   2666     return it->second;
   2667   }
   2668 
   2669   /// Given an opaque value expression, return its LValue mapping if it exists,
   2670   /// otherwise create one.
   2671   LValue getOrCreateOpaqueLValueMapping(const OpaqueValueExpr *e);
   2672 
   2673   /// Given an opaque value expression, return its RValue mapping if it exists,
   2674   /// otherwise create one.
   2675   RValue getOrCreateOpaqueRValueMapping(const OpaqueValueExpr *e);
   2676 
   2677   /// Get the index of the current ArrayInitLoopExpr, if any.
   2678   llvm::Value *getArrayInitIndex() { return ArrayInitIndex; }
   2679 
   2680   /// getAccessedFieldNo - Given an encoded value and a result number, return
   2681   /// the input field number being accessed.
   2682   static unsigned getAccessedFieldNo(unsigned Idx, const llvm::Constant *Elts);
   2683 
   2684   llvm::BlockAddress *GetAddrOfLabel(const LabelDecl *L);
   2685   llvm::BasicBlock *GetIndirectGotoBlock();
   2686 
   2687   /// Check if \p E is a C++ "this" pointer wrapped in value-preserving casts.
   2688   static bool IsWrappedCXXThis(const Expr *E);
   2689 
   2690   /// EmitNullInitialization - Generate code to set a value of the given type to
   2691   /// null, If the type contains data member pointers, they will be initialized
   2692   /// to -1 in accordance with the Itanium C++ ABI.
   2693   void EmitNullInitialization(Address DestPtr, QualType Ty);
   2694 
   2695   /// Emits a call to an LLVM variable-argument intrinsic, either
   2696   /// \c llvm.va_start or \c llvm.va_end.
   2697   /// \param ArgValue A reference to the \c va_list as emitted by either
   2698   /// \c EmitVAListRef or \c EmitMSVAListRef.
   2699   /// \param IsStart If \c true, emits a call to \c llvm.va_start; otherwise,
   2700   /// calls \c llvm.va_end.
   2701   llvm::Value *EmitVAStartEnd(llvm::Value *ArgValue, bool IsStart);
   2702 
   2703   /// Generate code to get an argument from the passed in pointer
   2704   /// and update it accordingly.
   2705   /// \param VE The \c VAArgExpr for which to generate code.
   2706   /// \param VAListAddr Receives a reference to the \c va_list as emitted by
   2707   /// either \c EmitVAListRef or \c EmitMSVAListRef.
   2708   /// \returns A pointer to the argument.
   2709   // FIXME: We should be able to get rid of this method and use the va_arg
   2710   // instruction in LLVM instead once it works well enough.
   2711   Address EmitVAArg(VAArgExpr *VE, Address &VAListAddr);
   2712 
   2713   /// emitArrayLength - Compute the length of an array, even if it's a
   2714   /// VLA, and drill down to the base element type.
   2715   llvm::Value *emitArrayLength(const ArrayType *arrayType,
   2716                                QualType &baseType,
   2717                                Address &addr);
   2718 
   2719   /// EmitVLASize - Capture all the sizes for the VLA expressions in
   2720   /// the given variably-modified type and store them in the VLASizeMap.
   2721   ///
   2722   /// This function can be called with a null (unreachable) insert point.
   2723   void EmitVariablyModifiedType(QualType Ty);
   2724 
   2725   struct VlaSizePair {
   2726     llvm::Value *NumElts;
   2727     QualType Type;
   2728 
   2729     VlaSizePair(llvm::Value *NE, QualType T) : NumElts(NE), Type(T) {}
   2730   };
   2731 
   2732   /// Return the number of elements for a single dimension
   2733   /// for the given array type.
   2734   VlaSizePair getVLAElements1D(const VariableArrayType *vla);
   2735   VlaSizePair getVLAElements1D(QualType vla);
   2736 
   2737   /// Returns an LLVM value that corresponds to the size,
   2738   /// in non-variably-sized elements, of a variable length array type,
   2739   /// plus that largest non-variably-sized element type.  Assumes that
   2740   /// the type has already been emitted with EmitVariablyModifiedType.
   2741   VlaSizePair getVLASize(const VariableArrayType *vla);
   2742   VlaSizePair getVLASize(QualType vla);
   2743 
   2744   /// LoadCXXThis - Load the value of 'this'. This function is only valid while
   2745   /// generating code for an C++ member function.
   2746   llvm::Value *LoadCXXThis() {
   2747     assert(CXXThisValue && "no 'this' value for this function");
   2748     return CXXThisValue;
   2749   }
   2750   Address LoadCXXThisAddress();
   2751 
   2752   /// LoadCXXVTT - Load the VTT parameter to base constructors/destructors have
   2753   /// virtual bases.
   2754   // FIXME: Every place that calls LoadCXXVTT is something
   2755   // that needs to be abstracted properly.
   2756   llvm::Value *LoadCXXVTT() {
   2757     assert(CXXStructorImplicitParamValue && "no VTT value for this function");
   2758     return CXXStructorImplicitParamValue;
   2759   }
   2760 
   2761   /// GetAddressOfBaseOfCompleteClass - Convert the given pointer to a
   2762   /// complete class to the given direct base.
   2763   Address
   2764   GetAddressOfDirectBaseInCompleteClass(Address Value,
   2765                                         const CXXRecordDecl *Derived,
   2766                                         const CXXRecordDecl *Base,
   2767                                         bool BaseIsVirtual);
   2768 
   2769   static bool ShouldNullCheckClassCastValue(const CastExpr *Cast);
   2770 
   2771   /// GetAddressOfBaseClass - This function will add the necessary delta to the
   2772   /// load of 'this' and returns address of the base class.
   2773   Address GetAddressOfBaseClass(Address Value,
   2774                                 const CXXRecordDecl *Derived,
   2775                                 CastExpr::path_const_iterator PathBegin,
   2776                                 CastExpr::path_const_iterator PathEnd,
   2777                                 bool NullCheckValue, SourceLocation Loc);
   2778 
   2779   Address GetAddressOfDerivedClass(Address Value,
   2780                                    const CXXRecordDecl *Derived,
   2781                                    CastExpr::path_const_iterator PathBegin,
   2782                                    CastExpr::path_const_iterator PathEnd,
   2783                                    bool NullCheckValue);
   2784 
   2785   /// GetVTTParameter - Return the VTT parameter that should be passed to a
   2786   /// base constructor/destructor with virtual bases.
   2787   /// FIXME: VTTs are Itanium ABI-specific, so the definition should move
   2788   /// to ItaniumCXXABI.cpp together with all the references to VTT.
   2789   llvm::Value *GetVTTParameter(GlobalDecl GD, bool ForVirtualBase,
   2790                                bool Delegating);
   2791 
   2792   void EmitDelegateCXXConstructorCall(const CXXConstructorDecl *Ctor,
   2793                                       CXXCtorType CtorType,
   2794                                       const FunctionArgList &Args,
   2795                                       SourceLocation Loc);
   2796   // It's important not to confuse this and the previous function. Delegating
   2797   // constructors are the C++0x feature. The constructor delegate optimization
   2798   // is used to reduce duplication in the base and complete consturctors where
   2799   // they are substantially the same.
   2800   void EmitDelegatingCXXConstructorCall(const CXXConstructorDecl *Ctor,
   2801                                         const FunctionArgList &Args);
   2802 
   2803   /// Emit a call to an inheriting constructor (that is, one that invokes a
   2804   /// constructor inherited from a base class) by inlining its definition. This
   2805   /// is necessary if the ABI does not support forwarding the arguments to the
   2806   /// base class constructor (because they're variadic or similar).
   2807   void EmitInlinedInheritingCXXConstructorCall(const CXXConstructorDecl *Ctor,
   2808                                                CXXCtorType CtorType,
   2809                                                bool ForVirtualBase,
   2810                                                bool Delegating,
   2811                                                CallArgList &Args);
   2812 
   2813   /// Emit a call to a constructor inherited from a base class, passing the
   2814   /// current constructor's arguments along unmodified (without even making
   2815   /// a copy).
   2816   void EmitInheritedCXXConstructorCall(const CXXConstructorDecl *D,
   2817                                        bool ForVirtualBase, Address This,
   2818                                        bool InheritedFromVBase,
   2819                                        const CXXInheritedCtorInitExpr *E);
   2820 
   2821   void EmitCXXConstructorCall(const CXXConstructorDecl *D, CXXCtorType Type,
   2822                               bool ForVirtualBase, bool Delegating,
   2823                               AggValueSlot ThisAVS, const CXXConstructExpr *E);
   2824 
   2825   void EmitCXXConstructorCall(const CXXConstructorDecl *D, CXXCtorType Type,
   2826                               bool ForVirtualBase, bool Delegating,
   2827                               Address This, CallArgList &Args,
   2828                               AggValueSlot::Overlap_t Overlap,
   2829                               SourceLocation Loc, bool NewPointerIsChecked);
   2830 
   2831   /// Emit assumption load for all bases. Requires to be be called only on
   2832   /// most-derived class and not under construction of the object.
   2833   void EmitVTableAssumptionLoads(const CXXRecordDecl *ClassDecl, Address This);
   2834 
   2835   /// Emit assumption that vptr load == global vtable.
   2836   void EmitVTableAssumptionLoad(const VPtr &vptr, Address This);
   2837 
   2838   void EmitSynthesizedCXXCopyCtorCall(const CXXConstructorDecl *D,
   2839                                       Address This, Address Src,
   2840                                       const CXXConstructExpr *E);
   2841 
   2842   void EmitCXXAggrConstructorCall(const CXXConstructorDecl *D,
   2843                                   const ArrayType *ArrayTy,
   2844                                   Address ArrayPtr,
   2845                                   const CXXConstructExpr *E,
   2846                                   bool NewPointerIsChecked,
   2847                                   bool ZeroInitialization = false);
   2848 
   2849   void EmitCXXAggrConstructorCall(const CXXConstructorDecl *D,
   2850                                   llvm::Value *NumElements,
   2851                                   Address ArrayPtr,
   2852                                   const CXXConstructExpr *E,
   2853                                   bool NewPointerIsChecked,
   2854                                   bool ZeroInitialization = false);
   2855 
   2856   static Destroyer destroyCXXObject;
   2857 
   2858   void EmitCXXDestructorCall(const CXXDestructorDecl *D, CXXDtorType Type,
   2859                              bool ForVirtualBase, bool Delegating, Address This,
   2860                              QualType ThisTy);
   2861 
   2862   void EmitNewArrayInitializer(const CXXNewExpr *E, QualType elementType,
   2863                                llvm::Type *ElementTy, Address NewPtr,
   2864                                llvm::Value *NumElements,
   2865                                llvm::Value *AllocSizeWithoutCookie);
   2866 
   2867   void EmitCXXTemporary(const CXXTemporary *Temporary, QualType TempType,
   2868                         Address Ptr);
   2869 
   2870   void EmitSehCppScopeBegin();
   2871   void EmitSehCppScopeEnd();
   2872   void EmitSehTryScopeBegin();
   2873   void EmitSehTryScopeEnd();
   2874 
   2875   llvm::Value *EmitLifetimeStart(uint64_t Size, llvm::Value *Addr);
   2876   void EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr);
   2877 
   2878   llvm::Value *EmitCXXNewExpr(const CXXNewExpr *E);
   2879   void EmitCXXDeleteExpr(const CXXDeleteExpr *E);
   2880 
   2881   void EmitDeleteCall(const FunctionDecl *DeleteFD, llvm::Value *Ptr,
   2882                       QualType DeleteTy, llvm::Value *NumElements = nullptr,
   2883                       CharUnits CookieSize = CharUnits());
   2884 
   2885   RValue EmitBuiltinNewDeleteCall(const FunctionProtoType *Type,
   2886                                   const CallExpr *TheCallExpr, bool IsDelete);
   2887 
   2888   llvm::Value *EmitCXXTypeidExpr(const CXXTypeidExpr *E);
   2889   llvm::Value *EmitDynamicCast(Address V, const CXXDynamicCastExpr *DCE);
   2890   Address EmitCXXUuidofExpr(const CXXUuidofExpr *E);
   2891 
   2892   /// Situations in which we might emit a check for the suitability of a
   2893   /// pointer or glvalue. Needs to be kept in sync with ubsan_handlers.cpp in
   2894   /// compiler-rt.
   2895   enum TypeCheckKind {
   2896     /// Checking the operand of a load. Must be suitably sized and aligned.
   2897     TCK_Load,
   2898     /// Checking the destination of a store. Must be suitably sized and aligned.
   2899     TCK_Store,
   2900     /// Checking the bound value in a reference binding. Must be suitably sized
   2901     /// and aligned, but is not required to refer to an object (until the
   2902     /// reference is used), per core issue 453.
   2903     TCK_ReferenceBinding,
   2904     /// Checking the object expression in a non-static data member access. Must
   2905     /// be an object within its lifetime.
   2906     TCK_MemberAccess,
   2907     /// Checking the 'this' pointer for a call to a non-static member function.
   2908     /// Must be an object within its lifetime.
   2909     TCK_MemberCall,
   2910     /// Checking the 'this' pointer for a constructor call.
   2911     TCK_ConstructorCall,
   2912     /// Checking the operand of a static_cast to a derived pointer type. Must be
   2913     /// null or an object within its lifetime.
   2914     TCK_DowncastPointer,
   2915     /// Checking the operand of a static_cast to a derived reference type. Must
   2916     /// be an object within its lifetime.
   2917     TCK_DowncastReference,
   2918     /// Checking the operand of a cast to a base object. Must be suitably sized
   2919     /// and aligned.
   2920     TCK_Upcast,
   2921     /// Checking the operand of a cast to a virtual base object. Must be an
   2922     /// object within its lifetime.
   2923     TCK_UpcastToVirtualBase,
   2924     /// Checking the value assigned to a _Nonnull pointer. Must not be null.
   2925     TCK_NonnullAssign,
   2926     /// Checking the operand of a dynamic_cast or a typeid expression.  Must be
   2927     /// null or an object within its lifetime.
   2928     TCK_DynamicOperation
   2929   };
   2930 
   2931   /// Determine whether the pointer type check \p TCK permits null pointers.
   2932   static bool isNullPointerAllowed(TypeCheckKind TCK);
   2933 
   2934   /// Determine whether the pointer type check \p TCK requires a vptr check.
   2935   static bool isVptrCheckRequired(TypeCheckKind TCK, QualType Ty);
   2936 
   2937   /// Whether any type-checking sanitizers are enabled. If \c false,
   2938   /// calls to EmitTypeCheck can be skipped.
   2939   bool sanitizePerformTypeCheck() const;
   2940 
   2941   /// Emit a check that \p V is the address of storage of the
   2942   /// appropriate size and alignment for an object of type \p Type
   2943   /// (or if ArraySize is provided, for an array of that bound).
   2944   void EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc, llvm::Value *V,
   2945                      QualType Type, CharUnits Alignment = CharUnits::Zero(),
   2946                      SanitizerSet SkippedChecks = SanitizerSet(),
   2947                      llvm::Value *ArraySize = nullptr);
   2948 
   2949   /// Emit a check that \p Base points into an array object, which
   2950   /// we can access at index \p Index. \p Accessed should be \c false if we
   2951   /// this expression is used as an lvalue, for instance in "&Arr[Idx]".
   2952   void EmitBoundsCheck(const Expr *E, const Expr *Base, llvm::Value *Index,
   2953                        QualType IndexType, bool Accessed);
   2954 
   2955   llvm::Value *EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
   2956                                        bool isInc, bool isPre);
   2957   ComplexPairTy EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
   2958                                          bool isInc, bool isPre);
   2959 
   2960   /// Converts Location to a DebugLoc, if debug information is enabled.
   2961   llvm::DebugLoc SourceLocToDebugLoc(SourceLocation Location);
   2962 
   2963   /// Get the record field index as represented in debug info.
   2964   unsigned getDebugInfoFIndex(const RecordDecl *Rec, unsigned FieldIndex);
   2965 
   2966 
   2967   //===--------------------------------------------------------------------===//
   2968   //                            Declaration Emission
   2969   //===--------------------------------------------------------------------===//
   2970 
   2971   /// EmitDecl - Emit a declaration.
   2972   ///
   2973   /// This function can be called with a null (unreachable) insert point.
   2974   void EmitDecl(const Decl &D);
   2975 
   2976   /// EmitVarDecl - Emit a local variable declaration.
   2977   ///
   2978   /// This function can be called with a null (unreachable) insert point.
   2979   void EmitVarDecl(const VarDecl &D);
   2980 
   2981   void EmitScalarInit(const Expr *init, const ValueDecl *D, LValue lvalue,
   2982                       bool capturedByInit);
   2983 
   2984   typedef void SpecialInitFn(CodeGenFunction &Init, const VarDecl &D,
   2985                              llvm::Value *Address);
   2986 
   2987   /// Determine whether the given initializer is trivial in the sense
   2988   /// that it requires no code to be generated.
   2989   bool isTrivialInitializer(const Expr *Init);
   2990 
   2991   /// EmitAutoVarDecl - Emit an auto variable declaration.
   2992   ///
   2993   /// This function can be called with a null (unreachable) insert point.
   2994   void EmitAutoVarDecl(const VarDecl &D);
   2995 
   2996   class AutoVarEmission {
   2997     friend class CodeGenFunction;
   2998 
   2999     const VarDecl *Variable;
   3000 
   3001     /// The address of the alloca for languages with explicit address space
   3002     /// (e.g. OpenCL) or alloca casted to generic pointer for address space
   3003     /// agnostic languages (e.g. C++). Invalid if the variable was emitted
   3004     /// as a global constant.
   3005     Address Addr;
   3006 
   3007     llvm::Value *NRVOFlag;
   3008 
   3009     /// True if the variable is a __block variable that is captured by an
   3010     /// escaping block.
   3011     bool IsEscapingByRef;
   3012 
   3013     /// True if the variable is of aggregate type and has a constant
   3014     /// initializer.
   3015     bool IsConstantAggregate;
   3016 
   3017     /// Non-null if we should use lifetime annotations.
   3018     llvm::Value *SizeForLifetimeMarkers;
   3019 
   3020     /// Address with original alloca instruction. Invalid if the variable was
   3021     /// emitted as a global constant.
   3022     Address AllocaAddr;
   3023 
   3024     struct Invalid {};
   3025     AutoVarEmission(Invalid)
   3026         : Variable(nullptr), Addr(Address::invalid()),
   3027           AllocaAddr(Address::invalid()) {}
   3028 
   3029     AutoVarEmission(const VarDecl &variable)
   3030         : Variable(&variable), Addr(Address::invalid()), NRVOFlag(nullptr),
   3031           IsEscapingByRef(false), IsConstantAggregate(false),
   3032           SizeForLifetimeMarkers(nullptr), AllocaAddr(Address::invalid()) {}
   3033 
   3034     bool wasEmittedAsGlobal() const { return !Addr.isValid(); }
   3035 
   3036   public:
   3037     static AutoVarEmission invalid() { return AutoVarEmission(Invalid()); }
   3038 
   3039     bool useLifetimeMarkers() const {
   3040       return SizeForLifetimeMarkers != nullptr;
   3041     }
   3042     llvm::Value *getSizeForLifetimeMarkers() const {
   3043       assert(useLifetimeMarkers());
   3044       return SizeForLifetimeMarkers;
   3045     }
   3046 
   3047     /// Returns the raw, allocated address, which is not necessarily
   3048     /// the address of the object itself. It is casted to default
   3049     /// address space for address space agnostic languages.
   3050     Address getAllocatedAddress() const {
   3051       return Addr;
   3052     }
   3053 
   3054     /// Returns the address for the original alloca instruction.
   3055     Address getOriginalAllocatedAddress() const { return AllocaAddr; }
   3056 
   3057     /// Returns the address of the object within this declaration.
   3058     /// Note that this does not chase the forwarding pointer for
   3059     /// __block decls.
   3060     Address getObjectAddress(CodeGenFunction &CGF) const {
   3061       if (!IsEscapingByRef) return Addr;
   3062 
   3063       return CGF.emitBlockByrefAddress(Addr, Variable, /*forward*/ false);
   3064     }
   3065   };
   3066   AutoVarEmission EmitAutoVarAlloca(const VarDecl &var);
   3067   void EmitAutoVarInit(const AutoVarEmission &emission);
   3068   void EmitAutoVarCleanups(const AutoVarEmission &emission);
   3069   void emitAutoVarTypeCleanup(const AutoVarEmission &emission,
   3070                               QualType::DestructionKind dtorKind);
   3071 
   3072   /// Emits the alloca and debug information for the size expressions for each
   3073   /// dimension of an array. It registers the association of its (1-dimensional)
   3074   /// QualTypes and size expression's debug node, so that CGDebugInfo can
   3075   /// reference this node when creating the DISubrange object to describe the
   3076   /// array types.
   3077   void EmitAndRegisterVariableArrayDimensions(CGDebugInfo *DI,
   3078                                               const VarDecl &D,
   3079                                               bool EmitDebugInfo);
   3080 
   3081   void EmitStaticVarDecl(const VarDecl &D,
   3082                          llvm::GlobalValue::LinkageTypes Linkage);
   3083 
   3084   class ParamValue {
   3085     llvm::Value *Value;
   3086     unsigned Alignment;
   3087     ParamValue(llvm::Value *V, unsigned A) : Value(V), Alignment(A) {}
   3088   public:
   3089     static ParamValue forDirect(llvm::Value *value) {
   3090       return ParamValue(value, 0);
   3091     }
   3092     static ParamValue forIndirect(Address addr) {
   3093       assert(!addr.getAlignment().isZero());
   3094       return ParamValue(addr.getPointer(), addr.getAlignment().getQuantity());
   3095     }
   3096 
   3097     bool isIndirect() const { return Alignment != 0; }
   3098     llvm::Value *getAnyValue() const { return Value; }
   3099 
   3100     llvm::Value *getDirectValue() const {
   3101       assert(!isIndirect());
   3102       return Value;
   3103     }
   3104 
   3105     Address getIndirectAddress() const {
   3106       assert(isIndirect());
   3107       return Address(Value, CharUnits::fromQuantity(Alignment));
   3108     }
   3109   };
   3110 
   3111   /// EmitParmDecl - Emit a ParmVarDecl or an ImplicitParamDecl.
   3112   void EmitParmDecl(const VarDecl &D, ParamValue Arg, unsigned ArgNo);
   3113 
   3114   /// protectFromPeepholes - Protect a value that we're intending to
   3115   /// store to the side, but which will probably be used later, from
   3116   /// aggressive peepholing optimizations that might delete it.
   3117   ///
   3118   /// Pass the result to unprotectFromPeepholes to declare that
   3119   /// protection is no longer required.
   3120   ///
   3121   /// There's no particular reason why this shouldn't apply to
   3122   /// l-values, it's just that no existing peepholes work on pointers.
   3123   PeepholeProtection protectFromPeepholes(RValue rvalue);
   3124   void unprotectFromPeepholes(PeepholeProtection protection);
   3125 
   3126   void emitAlignmentAssumptionCheck(llvm::Value *Ptr, QualType Ty,
   3127                                     SourceLocation Loc,
   3128                                     SourceLocation AssumptionLoc,
   3129                                     llvm::Value *Alignment,
   3130                                     llvm::Value *OffsetValue,
   3131                                     llvm::Value *TheCheck,
   3132                                     llvm::Instruction *Assumption);
   3133 
   3134   void emitAlignmentAssumption(llvm::Value *PtrValue, QualType Ty,
   3135                                SourceLocation Loc, SourceLocation AssumptionLoc,
   3136                                llvm::Value *Alignment,
   3137                                llvm::Value *OffsetValue = nullptr);
   3138 
   3139   void emitAlignmentAssumption(llvm::Value *PtrValue, const Expr *E,
   3140                                SourceLocation AssumptionLoc,
   3141                                llvm::Value *Alignment,
   3142                                llvm::Value *OffsetValue = nullptr);
   3143 
   3144   //===--------------------------------------------------------------------===//
   3145   //                             Statement Emission
   3146   //===--------------------------------------------------------------------===//
   3147 
   3148   /// EmitStopPoint - Emit a debug stoppoint if we are emitting debug info.
   3149   void EmitStopPoint(const Stmt *S);
   3150 
   3151   /// EmitStmt - Emit the code for the statement \arg S. It is legal to call
   3152   /// this function even if there is no current insertion point.
   3153   ///
   3154   /// This function may clear the current insertion point; callers should use
   3155   /// EnsureInsertPoint if they wish to subsequently generate code without first
   3156   /// calling EmitBlock, EmitBranch, or EmitStmt.
   3157   void EmitStmt(const Stmt *S, ArrayRef<const Attr *> Attrs = None);
   3158 
   3159   /// EmitSimpleStmt - Try to emit a "simple" statement which does not
   3160   /// necessarily require an insertion point or debug information; typically
   3161   /// because the statement amounts to a jump or a container of other
   3162   /// statements.
   3163   ///
   3164   /// \return True if the statement was handled.
   3165   bool EmitSimpleStmt(const Stmt *S, ArrayRef<const Attr *> Attrs);
   3166 
   3167   Address EmitCompoundStmt(const CompoundStmt &S, bool GetLast = false,
   3168                            AggValueSlot AVS = AggValueSlot::ignored());
   3169   Address EmitCompoundStmtWithoutScope(const CompoundStmt &S,
   3170                                        bool GetLast = false,
   3171                                        AggValueSlot AVS =
   3172                                                 AggValueSlot::ignored());
   3173 
   3174   /// EmitLabel - Emit the block for the given label. It is legal to call this
   3175   /// function even if there is no current insertion point.
   3176   void EmitLabel(const LabelDecl *D); // helper for EmitLabelStmt.
   3177 
   3178   void EmitLabelStmt(const LabelStmt &S);
   3179   void EmitAttributedStmt(const AttributedStmt &S);
   3180   void EmitGotoStmt(const GotoStmt &S);
   3181   void EmitIndirectGotoStmt(const IndirectGotoStmt &S);
   3182   void EmitIfStmt(const IfStmt &S);
   3183 
   3184   void EmitWhileStmt(const WhileStmt &S,
   3185                      ArrayRef<const Attr *> Attrs = None);
   3186   void EmitDoStmt(const DoStmt &S, ArrayRef<const Attr *> Attrs = None);
   3187   void EmitForStmt(const ForStmt &S,
   3188                    ArrayRef<const Attr *> Attrs = None);
   3189   void EmitReturnStmt(const ReturnStmt &S);
   3190   void EmitDeclStmt(const DeclStmt &S);
   3191   void EmitBreakStmt(const BreakStmt &S);
   3192   void EmitContinueStmt(const ContinueStmt &S);
   3193   void EmitSwitchStmt(const SwitchStmt &S);
   3194   void EmitDefaultStmt(const DefaultStmt &S, ArrayRef<const Attr *> Attrs);
   3195   void EmitCaseStmt(const CaseStmt &S, ArrayRef<const Attr *> Attrs);
   3196   void EmitCaseStmtRange(const CaseStmt &S, ArrayRef<const Attr *> Attrs);
   3197   void EmitAsmStmt(const AsmStmt &S);
   3198 
   3199   void EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S);
   3200   void EmitObjCAtTryStmt(const ObjCAtTryStmt &S);
   3201   void EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S);
   3202   void EmitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt &S);
   3203   void EmitObjCAutoreleasePoolStmt(const ObjCAutoreleasePoolStmt &S);
   3204 
   3205   void EmitCoroutineBody(const CoroutineBodyStmt &S);
   3206   void EmitCoreturnStmt(const CoreturnStmt &S);
   3207   RValue EmitCoawaitExpr(const CoawaitExpr &E,
   3208                          AggValueSlot aggSlot = AggValueSlot::ignored(),
   3209                          bool ignoreResult = false);
   3210   LValue EmitCoawaitLValue(const CoawaitExpr *E);
   3211   RValue EmitCoyieldExpr(const CoyieldExpr &E,
   3212                          AggValueSlot aggSlot = AggValueSlot::ignored(),
   3213                          bool ignoreResult = false);
   3214   LValue EmitCoyieldLValue(const CoyieldExpr *E);
   3215   RValue EmitCoroutineIntrinsic(const CallExpr *E, unsigned int IID);
   3216 
   3217   void EnterCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
   3218   void ExitCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock = false);
   3219 
   3220   void EmitCXXTryStmt(const CXXTryStmt &S);
   3221   void EmitSEHTryStmt(const SEHTryStmt &S);
   3222   void EmitSEHLeaveStmt(const SEHLeaveStmt &S);
   3223   void EnterSEHTryStmt(const SEHTryStmt &S);
   3224   void ExitSEHTryStmt(const SEHTryStmt &S);
   3225   void VolatilizeTryBlocks(llvm::BasicBlock *BB,
   3226                            llvm::SmallPtrSet<llvm::BasicBlock *, 10> &V);
   3227 
   3228   void pushSEHCleanup(CleanupKind kind,
   3229                       llvm::Function *FinallyFunc);
   3230   void startOutlinedSEHHelper(CodeGenFunction &ParentCGF, bool IsFilter,
   3231                               const Stmt *OutlinedStmt);
   3232 
   3233   llvm::Function *GenerateSEHFilterFunction(CodeGenFunction &ParentCGF,
   3234                                             const SEHExceptStmt &Except);
   3235 
   3236   llvm::Function *GenerateSEHFinallyFunction(CodeGenFunction &ParentCGF,
   3237                                              const SEHFinallyStmt &Finally);
   3238 
   3239   void EmitSEHExceptionCodeSave(CodeGenFunction &ParentCGF,
   3240                                 llvm::Value *ParentFP,
   3241                                 llvm::Value *EntryEBP);
   3242   llvm::Value *EmitSEHExceptionCode();
   3243   llvm::Value *EmitSEHExceptionInfo();
   3244   llvm::Value *EmitSEHAbnormalTermination();
   3245 
   3246   /// Emit simple code for OpenMP directives in Simd-only mode.
   3247   void EmitSimpleOMPExecutableDirective(const OMPExecutableDirective &D);
   3248 
   3249   /// Scan the outlined statement for captures from the parent function. For
   3250   /// each capture, mark the capture as escaped and emit a call to
   3251   /// llvm.localrecover. Insert the localrecover result into the LocalDeclMap.
   3252   void EmitCapturedLocals(CodeGenFunction &ParentCGF, const Stmt *OutlinedStmt,
   3253                           bool IsFilter);
   3254 
   3255   /// Recovers the address of a local in a parent function. ParentVar is the
   3256   /// address of the variable used in the immediate parent function. It can
   3257   /// either be an alloca or a call to llvm.localrecover if there are nested
   3258   /// outlined functions. ParentFP is the frame pointer of the outermost parent
   3259   /// frame.
   3260   Address recoverAddrOfEscapedLocal(CodeGenFunction &ParentCGF,
   3261                                     Address ParentVar,
   3262                                     llvm::Value *ParentFP);
   3263 
   3264   void EmitCXXForRangeStmt(const CXXForRangeStmt &S,
   3265                            ArrayRef<const Attr *> Attrs = None);
   3266 
   3267   /// Controls insertion of cancellation exit blocks in worksharing constructs.
   3268   class OMPCancelStackRAII {
   3269     CodeGenFunction &CGF;
   3270 
   3271   public:
   3272     OMPCancelStackRAII(CodeGenFunction &CGF, OpenMPDirectiveKind Kind,
   3273                        bool HasCancel)
   3274         : CGF(CGF) {
   3275       CGF.OMPCancelStack.enter(CGF, Kind, HasCancel);
   3276     }
   3277     ~OMPCancelStackRAII() { CGF.OMPCancelStack.exit(CGF); }
   3278   };
   3279 
   3280   /// Returns calculated size of the specified type.
   3281   llvm::Value *getTypeSize(QualType Ty);
   3282   LValue InitCapturedStruct(const CapturedStmt &S);
   3283   llvm::Function *EmitCapturedStmt(const CapturedStmt &S, CapturedRegionKind K);
   3284   llvm::Function *GenerateCapturedStmtFunction(const CapturedStmt &S);
   3285   Address GenerateCapturedStmtArgument(const CapturedStmt &S);
   3286   llvm::Function *GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S,
   3287                                                      SourceLocation Loc);
   3288   void GenerateOpenMPCapturedVars(const CapturedStmt &S,
   3289                                   SmallVectorImpl<llvm::Value *> &CapturedVars);
   3290   void emitOMPSimpleStore(LValue LVal, RValue RVal, QualType RValTy,
   3291                           SourceLocation Loc);
   3292   /// Perform element by element copying of arrays with type \a
   3293   /// OriginalType from \a SrcAddr to \a DestAddr using copying procedure
   3294   /// generated by \a CopyGen.
   3295   ///
   3296   /// \param DestAddr Address of the destination array.
   3297   /// \param SrcAddr Address of the source array.
   3298   /// \param OriginalType Type of destination and source arrays.
   3299   /// \param CopyGen Copying procedure that copies value of single array element
   3300   /// to another single array element.
   3301   void EmitOMPAggregateAssign(
   3302       Address DestAddr, Address SrcAddr, QualType OriginalType,
   3303       const llvm::function_ref<void(Address, Address)> CopyGen);
   3304   /// Emit proper copying of data from one variable to another.
   3305   ///
   3306   /// \param OriginalType Original type of the copied variables.
   3307   /// \param DestAddr Destination address.
   3308   /// \param SrcAddr Source address.
   3309   /// \param DestVD Destination variable used in \a CopyExpr (for arrays, has
   3310   /// type of the base array element).
   3311   /// \param SrcVD Source variable used in \a CopyExpr (for arrays, has type of
   3312   /// the base array element).
   3313   /// \param Copy Actual copygin expression for copying data from \a SrcVD to \a
   3314   /// DestVD.
   3315   void EmitOMPCopy(QualType OriginalType,
   3316                    Address DestAddr, Address SrcAddr,
   3317                    const VarDecl *DestVD, const VarDecl *SrcVD,
   3318                    const Expr *Copy);
   3319   /// Emit atomic update code for constructs: \a X = \a X \a BO \a E or
   3320   /// \a X = \a E \a BO \a E.
   3321   ///
   3322   /// \param X Value to be updated.
   3323   /// \param E Update value.
   3324   /// \param BO Binary operation for update operation.
   3325   /// \param IsXLHSInRHSPart true if \a X is LHS in RHS part of the update
   3326   /// expression, false otherwise.
   3327   /// \param AO Atomic ordering of the generated atomic instructions.
   3328   /// \param CommonGen Code generator for complex expressions that cannot be
   3329   /// expressed through atomicrmw instruction.
   3330   /// \returns <true, OldAtomicValue> if simple 'atomicrmw' instruction was
   3331   /// generated, <false, RValue::get(nullptr)> otherwise.
   3332   std::pair<bool, RValue> EmitOMPAtomicSimpleUpdateExpr(
   3333       LValue X, RValue E, BinaryOperatorKind BO, bool IsXLHSInRHSPart,
   3334       llvm::AtomicOrdering AO, SourceLocation Loc,
   3335       const llvm::function_ref<RValue(RValue)> CommonGen);
   3336   bool EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
   3337                                  OMPPrivateScope &PrivateScope);
   3338   void EmitOMPPrivateClause(const OMPExecutableDirective &D,
   3339                             OMPPrivateScope &PrivateScope);
   3340   void EmitOMPUseDevicePtrClause(
   3341       const OMPUseDevicePtrClause &C, OMPPrivateScope &PrivateScope,
   3342       const llvm::DenseMap<const ValueDecl *, Address> &CaptureDeviceAddrMap);
   3343   void EmitOMPUseDeviceAddrClause(
   3344       const OMPUseDeviceAddrClause &C, OMPPrivateScope &PrivateScope,
   3345       const llvm::DenseMap<const ValueDecl *, Address> &CaptureDeviceAddrMap);
   3346   /// Emit code for copyin clause in \a D directive. The next code is
   3347   /// generated at the start of outlined functions for directives:
   3348   /// \code
   3349   /// threadprivate_var1 = master_threadprivate_var1;
   3350   /// operator=(threadprivate_var2, master_threadprivate_var2);
   3351   /// ...
   3352   /// __kmpc_barrier(&loc, global_tid);
   3353   /// \endcode
   3354   ///
   3355   /// \param D OpenMP directive possibly with 'copyin' clause(s).
   3356   /// \returns true if at least one copyin variable is found, false otherwise.
   3357   bool EmitOMPCopyinClause(const OMPExecutableDirective &D);
   3358   /// Emit initial code for lastprivate variables. If some variable is
   3359   /// not also firstprivate, then the default initialization is used. Otherwise
   3360   /// initialization of this variable is performed by EmitOMPFirstprivateClause
   3361   /// method.
   3362   ///
   3363   /// \param D Directive that may have 'lastprivate' directives.
   3364   /// \param PrivateScope Private scope for capturing lastprivate variables for
   3365   /// proper codegen in internal captured statement.
   3366   ///
   3367   /// \returns true if there is at least one lastprivate variable, false
   3368   /// otherwise.
   3369   bool EmitOMPLastprivateClauseInit(const OMPExecutableDirective &D,
   3370                                     OMPPrivateScope &PrivateScope);
   3371   /// Emit final copying of lastprivate values to original variables at
   3372   /// the end of the worksharing or simd directive.
   3373   ///
   3374   /// \param D Directive that has at least one 'lastprivate' directives.
   3375   /// \param IsLastIterCond Boolean condition that must be set to 'i1 true' if
   3376   /// it is the last iteration of the loop code in associated directive, or to
   3377   /// 'i1 false' otherwise. If this item is nullptr, no final check is required.
   3378   void EmitOMPLastprivateClauseFinal(const OMPExecutableDirective &D,
   3379                                      bool NoFinals,
   3380                                      llvm::Value *IsLastIterCond = nullptr);
   3381   /// Emit initial code for linear clauses.
   3382   void EmitOMPLinearClause(const OMPLoopDirective &D,
   3383                            CodeGenFunction::OMPPrivateScope &PrivateScope);
   3384   /// Emit final code for linear clauses.
   3385   /// \param CondGen Optional conditional code for final part of codegen for
   3386   /// linear clause.
   3387   void EmitOMPLinearClauseFinal(
   3388       const OMPLoopDirective &D,
   3389       const llvm::function_ref<llvm::Value *(CodeGenFunction &)> CondGen);
   3390   /// Emit initial code for reduction variables. Creates reduction copies
   3391   /// and initializes them with the values according to OpenMP standard.
   3392   ///
   3393   /// \param D Directive (possibly) with the 'reduction' clause.
   3394   /// \param PrivateScope Private scope for capturing reduction variables for
   3395   /// proper codegen in internal captured statement.
   3396   ///
   3397   void EmitOMPReductionClauseInit(const OMPExecutableDirective &D,
   3398                                   OMPPrivateScope &PrivateScope,
   3399                                   bool ForInscan = false);
   3400   /// Emit final update of reduction values to original variables at
   3401   /// the end of the directive.
   3402   ///
   3403   /// \param D Directive that has at least one 'reduction' directives.
   3404   /// \param ReductionKind The kind of reduction to perform.
   3405   void EmitOMPReductionClauseFinal(const OMPExecutableDirective &D,
   3406                                    const OpenMPDirectiveKind ReductionKind);
   3407   /// Emit initial code for linear variables. Creates private copies
   3408   /// and initializes them with the values according to OpenMP standard.
   3409   ///
   3410   /// \param D Directive (possibly) with the 'linear' clause.
   3411   /// \return true if at least one linear variable is found that should be
   3412   /// initialized with the value of the original variable, false otherwise.
   3413   bool EmitOMPLinearClauseInit(const OMPLoopDirective &D);
   3414 
   3415   typedef const llvm::function_ref<void(CodeGenFunction & /*CGF*/,
   3416                                         llvm::Function * /*OutlinedFn*/,
   3417                                         const OMPTaskDataTy & /*Data*/)>
   3418       TaskGenTy;
   3419   void EmitOMPTaskBasedDirective(const OMPExecutableDirective &S,
   3420                                  const OpenMPDirectiveKind CapturedRegion,
   3421                                  const RegionCodeGenTy &BodyGen,
   3422                                  const TaskGenTy &TaskGen, OMPTaskDataTy &Data);
   3423   struct OMPTargetDataInfo {
   3424     Address BasePointersArray = Address::invalid();
   3425     Address PointersArray = Address::invalid();
   3426     Address SizesArray = Address::invalid();
   3427     Address MappersArray = Address::invalid();
   3428     unsigned NumberOfTargetItems = 0;
   3429     explicit OMPTargetDataInfo() = default;
   3430     OMPTargetDataInfo(Address BasePointersArray, Address PointersArray,
   3431                       Address SizesArray, Address MappersArray,
   3432                       unsigned NumberOfTargetItems)
   3433         : BasePointersArray(BasePointersArray), PointersArray(PointersArray),
   3434           SizesArray(SizesArray), MappersArray(MappersArray),
   3435           NumberOfTargetItems(NumberOfTargetItems) {}
   3436   };
   3437   void EmitOMPTargetTaskBasedDirective(const OMPExecutableDirective &S,
   3438                                        const RegionCodeGenTy &BodyGen,
   3439                                        OMPTargetDataInfo &InputInfo);
   3440 
   3441   void EmitOMPParallelDirective(const OMPParallelDirective &S);
   3442   void EmitOMPSimdDirective(const OMPSimdDirective &S);
   3443   void EmitOMPTileDirective(const OMPTileDirective &S);
   3444   void EmitOMPForDirective(const OMPForDirective &S);
   3445   void EmitOMPForSimdDirective(const OMPForSimdDirective &S);
   3446   void EmitOMPSectionsDirective(const OMPSectionsDirective &S);
   3447   void EmitOMPSectionDirective(const OMPSectionDirective &S);
   3448   void EmitOMPSingleDirective(const OMPSingleDirective &S);
   3449   void EmitOMPMasterDirective(const OMPMasterDirective &S);
   3450   void EmitOMPMaskedDirective(const OMPMaskedDirective &S);
   3451   void EmitOMPCriticalDirective(const OMPCriticalDirective &S);
   3452   void EmitOMPParallelForDirective(const OMPParallelForDirective &S);
   3453   void EmitOMPParallelForSimdDirective(const OMPParallelForSimdDirective &S);
   3454   void EmitOMPParallelSectionsDirective(const OMPParallelSectionsDirective &S);
   3455   void EmitOMPParallelMasterDirective(const OMPParallelMasterDirective &S);
   3456   void EmitOMPTaskDirective(const OMPTaskDirective &S);
   3457   void EmitOMPTaskyieldDirective(const OMPTaskyieldDirective &S);
   3458   void EmitOMPBarrierDirective(const OMPBarrierDirective &S);
   3459   void EmitOMPTaskwaitDirective(const OMPTaskwaitDirective &S);
   3460   void EmitOMPTaskgroupDirective(const OMPTaskgroupDirective &S);
   3461   void EmitOMPFlushDirective(const OMPFlushDirective &S);
   3462   void EmitOMPDepobjDirective(const OMPDepobjDirective &S);
   3463   void EmitOMPScanDirective(const OMPScanDirective &S);
   3464   void EmitOMPOrderedDirective(const OMPOrderedDirective &S);
   3465   void EmitOMPAtomicDirective(const OMPAtomicDirective &S);
   3466   void EmitOMPTargetDirective(const OMPTargetDirective &S);
   3467   void EmitOMPTargetDataDirective(const OMPTargetDataDirective &S);
   3468   void EmitOMPTargetEnterDataDirective(const OMPTargetEnterDataDirective &S);
   3469   void EmitOMPTargetExitDataDirective(const OMPTargetExitDataDirective &S);
   3470   void EmitOMPTargetUpdateDirective(const OMPTargetUpdateDirective &S);
   3471   void EmitOMPTargetParallelDirective(const OMPTargetParallelDirective &S);
   3472   void
   3473   EmitOMPTargetParallelForDirective(const OMPTargetParallelForDirective &S);
   3474   void EmitOMPTeamsDirective(const OMPTeamsDirective &S);
   3475   void
   3476   EmitOMPCancellationPointDirective(const OMPCancellationPointDirective &S);
   3477   void EmitOMPCancelDirective(const OMPCancelDirective &S);
   3478   void EmitOMPTaskLoopBasedDirective(const OMPLoopDirective &S);
   3479   void EmitOMPTaskLoopDirective(const OMPTaskLoopDirective &S);
   3480   void EmitOMPTaskLoopSimdDirective(const OMPTaskLoopSimdDirective &S);
   3481   void EmitOMPMasterTaskLoopDirective(const OMPMasterTaskLoopDirective &S);
   3482   void
   3483   EmitOMPMasterTaskLoopSimdDirective(const OMPMasterTaskLoopSimdDirective &S);
   3484   void EmitOMPParallelMasterTaskLoopDirective(
   3485       const OMPParallelMasterTaskLoopDirective &S);
   3486   void EmitOMPParallelMasterTaskLoopSimdDirective(
   3487       const OMPParallelMasterTaskLoopSimdDirective &S);
   3488   void EmitOMPDistributeDirective(const OMPDistributeDirective &S);
   3489   void EmitOMPDistributeParallelForDirective(
   3490       const OMPDistributeParallelForDirective &S);
   3491   void EmitOMPDistributeParallelForSimdDirective(
   3492       const OMPDistributeParallelForSimdDirective &S);
   3493   void EmitOMPDistributeSimdDirective(const OMPDistributeSimdDirective &S);
   3494   void EmitOMPTargetParallelForSimdDirective(
   3495       const OMPTargetParallelForSimdDirective &S);
   3496   void EmitOMPTargetSimdDirective(const OMPTargetSimdDirective &S);
   3497   void EmitOMPTeamsDistributeDirective(const OMPTeamsDistributeDirective &S);
   3498   void
   3499   EmitOMPTeamsDistributeSimdDirective(const OMPTeamsDistributeSimdDirective &S);
   3500   void EmitOMPTeamsDistributeParallelForSimdDirective(
   3501       const OMPTeamsDistributeParallelForSimdDirective &S);
   3502   void EmitOMPTeamsDistributeParallelForDirective(
   3503       const OMPTeamsDistributeParallelForDirective &S);
   3504   void EmitOMPTargetTeamsDirective(const OMPTargetTeamsDirective &S);
   3505   void EmitOMPTargetTeamsDistributeDirective(
   3506       const OMPTargetTeamsDistributeDirective &S);
   3507   void EmitOMPTargetTeamsDistributeParallelForDirective(
   3508       const OMPTargetTeamsDistributeParallelForDirective &S);
   3509   void EmitOMPTargetTeamsDistributeParallelForSimdDirective(
   3510       const OMPTargetTeamsDistributeParallelForSimdDirective &S);
   3511   void EmitOMPTargetTeamsDistributeSimdDirective(
   3512       const OMPTargetTeamsDistributeSimdDirective &S);
   3513 
   3514   /// Emit device code for the target directive.
   3515   static void EmitOMPTargetDeviceFunction(CodeGenModule &CGM,
   3516                                           StringRef ParentName,
   3517                                           const OMPTargetDirective &S);
   3518   static void
   3519   EmitOMPTargetParallelDeviceFunction(CodeGenModule &CGM, StringRef ParentName,
   3520                                       const OMPTargetParallelDirective &S);
   3521   /// Emit device code for the target parallel for directive.
   3522   static void EmitOMPTargetParallelForDeviceFunction(
   3523       CodeGenModule &CGM, StringRef ParentName,
   3524       const OMPTargetParallelForDirective &S);
   3525   /// Emit device code for the target parallel for simd directive.
   3526   static void EmitOMPTargetParallelForSimdDeviceFunction(
   3527       CodeGenModule &CGM, StringRef ParentName,
   3528       const OMPTargetParallelForSimdDirective &S);
   3529   /// Emit device code for the target teams directive.
   3530   static void
   3531   EmitOMPTargetTeamsDeviceFunction(CodeGenModule &CGM, StringRef ParentName,
   3532                                    const OMPTargetTeamsDirective &S);
   3533   /// Emit device code for the target teams distribute directive.
   3534   static void EmitOMPTargetTeamsDistributeDeviceFunction(
   3535       CodeGenModule &CGM, StringRef ParentName,
   3536       const OMPTargetTeamsDistributeDirective &S);
   3537   /// Emit device code for the target teams distribute simd directive.
   3538   static void EmitOMPTargetTeamsDistributeSimdDeviceFunction(
   3539       CodeGenModule &CGM, StringRef ParentName,
   3540       const OMPTargetTeamsDistributeSimdDirective &S);
   3541   /// Emit device code for the target simd directive.
   3542   static void EmitOMPTargetSimdDeviceFunction(CodeGenModule &CGM,
   3543                                               StringRef ParentName,
   3544                                               const OMPTargetSimdDirective &S);
   3545   /// Emit device code for the target teams distribute parallel for simd
   3546   /// directive.
   3547   static void EmitOMPTargetTeamsDistributeParallelForSimdDeviceFunction(
   3548       CodeGenModule &CGM, StringRef ParentName,
   3549       const OMPTargetTeamsDistributeParallelForSimdDirective &S);
   3550 
   3551   static void EmitOMPTargetTeamsDistributeParallelForDeviceFunction(
   3552       CodeGenModule &CGM, StringRef ParentName,
   3553       const OMPTargetTeamsDistributeParallelForDirective &S);
   3554 
   3555   /// Emit the Stmt \p S and return its topmost canonical loop, if any.
   3556   /// TODO: The \p Depth paramter is not yet implemented and must be 1. In the
   3557   /// future it is meant to be the number of loops expected in the loop nests
   3558   /// (usually specified by the "collapse" clause) that are collapsed to a
   3559   /// single loop by this function.
   3560   llvm::CanonicalLoopInfo *EmitOMPCollapsedCanonicalLoopNest(const Stmt *S,
   3561                                                              int Depth);
   3562 
   3563   /// Emit an OMPCanonicalLoop using the OpenMPIRBuilder.
   3564   void EmitOMPCanonicalLoop(const OMPCanonicalLoop *S);
   3565 
   3566   /// Emit inner loop of the worksharing/simd construct.
   3567   ///
   3568   /// \param S Directive, for which the inner loop must be emitted.
   3569   /// \param RequiresCleanup true, if directive has some associated private
   3570   /// variables.
   3571   /// \param LoopCond Bollean condition for loop continuation.
   3572   /// \param IncExpr Increment expression for loop control variable.
   3573   /// \param BodyGen Generator for the inner body of the inner loop.
   3574   /// \param PostIncGen Genrator for post-increment code (required for ordered
   3575   /// loop directvies).
   3576   void EmitOMPInnerLoop(
   3577       const OMPExecutableDirective &S, bool RequiresCleanup,
   3578       const Expr *LoopCond, const Expr *IncExpr,
   3579       const llvm::function_ref<void(CodeGenFunction &)> BodyGen,
   3580       const llvm::function_ref<void(CodeGenFunction &)> PostIncGen);
   3581 
   3582   JumpDest getOMPCancelDestination(OpenMPDirectiveKind Kind);
   3583   /// Emit initial code for loop counters of loop-based directives.
   3584   void EmitOMPPrivateLoopCounters(const OMPLoopDirective &S,
   3585                                   OMPPrivateScope &LoopScope);
   3586 
   3587   /// Helper for the OpenMP loop directives.
   3588   void EmitOMPLoopBody(const OMPLoopDirective &D, JumpDest LoopExit);
   3589 
   3590   /// Emit code for the worksharing loop-based directive.
   3591   /// \return true, if this construct has any lastprivate clause, false -
   3592   /// otherwise.
   3593   bool EmitOMPWorksharingLoop(const OMPLoopDirective &S, Expr *EUB,
   3594                               const CodeGenLoopBoundsTy &CodeGenLoopBounds,
   3595                               const CodeGenDispatchBoundsTy &CGDispatchBounds);
   3596 
   3597   /// Emit code for the distribute loop-based directive.
   3598   void EmitOMPDistributeLoop(const OMPLoopDirective &S,
   3599                              const CodeGenLoopTy &CodeGenLoop, Expr *IncExpr);
   3600 
   3601   /// Helpers for the OpenMP loop directives.
   3602   void EmitOMPSimdInit(const OMPLoopDirective &D, bool IsMonotonic = false);
   3603   void EmitOMPSimdFinal(
   3604       const OMPLoopDirective &D,
   3605       const llvm::function_ref<llvm::Value *(CodeGenFunction &)> CondGen);
   3606 
   3607   /// Emits the lvalue for the expression with possibly captured variable.
   3608   LValue EmitOMPSharedLValue(const Expr *E);
   3609 
   3610 private:
   3611   /// Helpers for blocks.
   3612   llvm::Value *EmitBlockLiteral(const CGBlockInfo &Info);
   3613 
   3614   /// struct with the values to be passed to the OpenMP loop-related functions
   3615   struct OMPLoopArguments {
   3616     /// loop lower bound
   3617     Address LB = Address::invalid();
   3618     /// loop upper bound
   3619     Address UB = Address::invalid();
   3620     /// loop stride
   3621     Address ST = Address::invalid();
   3622     /// isLastIteration argument for runtime functions
   3623     Address IL = Address::invalid();
   3624     /// Chunk value generated by sema
   3625     llvm::Value *Chunk = nullptr;
   3626     /// EnsureUpperBound
   3627     Expr *EUB = nullptr;
   3628     /// IncrementExpression
   3629     Expr *IncExpr = nullptr;
   3630     /// Loop initialization
   3631     Expr *Init = nullptr;
   3632     /// Loop exit condition
   3633     Expr *Cond = nullptr;
   3634     /// Update of LB after a whole chunk has been executed
   3635     Expr *NextLB = nullptr;
   3636     /// Update of UB after a whole chunk has been executed
   3637     Expr *NextUB = nullptr;
   3638     OMPLoopArguments() = default;
   3639     OMPLoopArguments(Address LB, Address UB, Address ST, Address IL,
   3640                      llvm::Value *Chunk = nullptr, Expr *EUB = nullptr,
   3641                      Expr *IncExpr = nullptr, Expr *Init = nullptr,
   3642                      Expr *Cond = nullptr, Expr *NextLB = nullptr,
   3643                      Expr *NextUB = nullptr)
   3644         : LB(LB), UB(UB), ST(ST), IL(IL), Chunk(Chunk), EUB(EUB),
   3645           IncExpr(IncExpr), Init(Init), Cond(Cond), NextLB(NextLB),
   3646           NextUB(NextUB) {}
   3647   };
   3648   void EmitOMPOuterLoop(bool DynamicOrOrdered, bool IsMonotonic,
   3649                         const OMPLoopDirective &S, OMPPrivateScope &LoopScope,
   3650                         const OMPLoopArguments &LoopArgs,
   3651                         const CodeGenLoopTy &CodeGenLoop,
   3652                         const CodeGenOrderedTy &CodeGenOrdered);
   3653   void EmitOMPForOuterLoop(const OpenMPScheduleTy &ScheduleKind,
   3654                            bool IsMonotonic, const OMPLoopDirective &S,
   3655                            OMPPrivateScope &LoopScope, bool Ordered,
   3656                            const OMPLoopArguments &LoopArgs,
   3657                            const CodeGenDispatchBoundsTy &CGDispatchBounds);
   3658   void EmitOMPDistributeOuterLoop(OpenMPDistScheduleClauseKind ScheduleKind,
   3659                                   const OMPLoopDirective &S,
   3660                                   OMPPrivateScope &LoopScope,
   3661                                   const OMPLoopArguments &LoopArgs,
   3662                                   const CodeGenLoopTy &CodeGenLoopContent);
   3663   /// Emit code for sections directive.
   3664   void EmitSections(const OMPExecutableDirective &S);
   3665 
   3666 public:
   3667 
   3668   //===--------------------------------------------------------------------===//
   3669   //                         LValue Expression Emission
   3670   //===--------------------------------------------------------------------===//
   3671 
   3672   /// Create a check that a scalar RValue is non-null.
   3673   llvm::Value *EmitNonNullRValueCheck(RValue RV, QualType T);
   3674 
   3675   /// GetUndefRValue - Get an appropriate 'undef' rvalue for the given type.
   3676   RValue GetUndefRValue(QualType Ty);
   3677 
   3678   /// EmitUnsupportedRValue - Emit a dummy r-value using the type of E
   3679   /// and issue an ErrorUnsupported style diagnostic (using the
   3680   /// provided Name).
   3681   RValue EmitUnsupportedRValue(const Expr *E,
   3682                                const char *Name);
   3683 
   3684   /// EmitUnsupportedLValue - Emit a dummy l-value using the type of E and issue
   3685   /// an ErrorUnsupported style diagnostic (using the provided Name).
   3686   LValue EmitUnsupportedLValue(const Expr *E,
   3687                                const char *Name);
   3688 
   3689   /// EmitLValue - Emit code to compute a designator that specifies the location
   3690   /// of the expression.
   3691   ///
   3692   /// This can return one of two things: a simple address or a bitfield
   3693   /// reference.  In either case, the LLVM Value* in the LValue structure is
   3694   /// guaranteed to be an LLVM pointer type.
   3695   ///
   3696   /// If this returns a bitfield reference, nothing about the pointee type of
   3697   /// the LLVM value is known: For example, it may not be a pointer to an
   3698   /// integer.
   3699   ///
   3700   /// If this returns a normal address, and if the lvalue's C type is fixed
   3701   /// size, this method guarantees that the returned pointer type will point to
   3702   /// an LLVM type of the same size of the lvalue's type.  If the lvalue has a
   3703   /// variable length type, this is not possible.
   3704   ///
   3705   LValue EmitLValue(const Expr *E);
   3706 
   3707   /// Same as EmitLValue but additionally we generate checking code to
   3708   /// guard against undefined behavior.  This is only suitable when we know
   3709   /// that the address will be used to access the object.
   3710   LValue EmitCheckedLValue(const Expr *E, TypeCheckKind TCK);
   3711 
   3712   RValue convertTempToRValue(Address addr, QualType type,
   3713                              SourceLocation Loc);
   3714 
   3715   void EmitAtomicInit(Expr *E, LValue lvalue);
   3716 
   3717   bool LValueIsSuitableForInlineAtomic(LValue Src);
   3718 
   3719   RValue EmitAtomicLoad(LValue LV, SourceLocation SL,
   3720                         AggValueSlot Slot = AggValueSlot::ignored());
   3721 
   3722   RValue EmitAtomicLoad(LValue lvalue, SourceLocation loc,
   3723                         llvm::AtomicOrdering AO, bool IsVolatile = false,
   3724                         AggValueSlot slot = AggValueSlot::ignored());
   3725 
   3726   void EmitAtomicStore(RValue rvalue, LValue lvalue, bool isInit);
   3727 
   3728   void EmitAtomicStore(RValue rvalue, LValue lvalue, llvm::AtomicOrdering AO,
   3729                        bool IsVolatile, bool isInit);
   3730 
   3731   std::pair<RValue, llvm::Value *> EmitAtomicCompareExchange(
   3732       LValue Obj, RValue Expected, RValue Desired, SourceLocation Loc,
   3733       llvm::AtomicOrdering Success =
   3734           llvm::AtomicOrdering::SequentiallyConsistent,
   3735       llvm::AtomicOrdering Failure =
   3736           llvm::AtomicOrdering::SequentiallyConsistent,
   3737       bool IsWeak = false, AggValueSlot Slot = AggValueSlot::ignored());
   3738 
   3739   void EmitAtomicUpdate(LValue LVal, llvm::AtomicOrdering AO,
   3740                         const llvm::function_ref<RValue(RValue)> &UpdateOp,
   3741                         bool IsVolatile);
   3742 
   3743   /// EmitToMemory - Change a scalar value from its value
   3744   /// representation to its in-memory representation.
   3745   llvm::Value *EmitToMemory(llvm::Value *Value, QualType Ty);
   3746 
   3747   /// EmitFromMemory - Change a scalar value from its memory
   3748   /// representation to its value representation.
   3749   llvm::Value *EmitFromMemory(llvm::Value *Value, QualType Ty);
   3750 
   3751   /// Check if the scalar \p Value is within the valid range for the given
   3752   /// type \p Ty.
   3753   ///
   3754   /// Returns true if a check is needed (even if the range is unknown).
   3755   bool EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
   3756                             SourceLocation Loc);
   3757 
   3758   /// EmitLoadOfScalar - Load a scalar value from an address, taking
   3759   /// care to appropriately convert from the memory representation to
   3760   /// the LLVM value representation.
   3761   llvm::Value *EmitLoadOfScalar(Address Addr, bool Volatile, QualType Ty,
   3762                                 SourceLocation Loc,
   3763                                 AlignmentSource Source = AlignmentSource::Type,
   3764                                 bool isNontemporal = false) {
   3765     return EmitLoadOfScalar(Addr, Volatile, Ty, Loc, LValueBaseInfo(Source),
   3766                             CGM.getTBAAAccessInfo(Ty), isNontemporal);
   3767   }
   3768 
   3769   llvm::Value *EmitLoadOfScalar(Address Addr, bool Volatile, QualType Ty,
   3770                                 SourceLocation Loc, LValueBaseInfo BaseInfo,
   3771                                 TBAAAccessInfo TBAAInfo,
   3772                                 bool isNontemporal = false);
   3773 
   3774   /// EmitLoadOfScalar - Load a scalar value from an address, taking
   3775   /// care to appropriately convert from the memory representation to
   3776   /// the LLVM value representation.  The l-value must be a simple
   3777   /// l-value.
   3778   llvm::Value *EmitLoadOfScalar(LValue lvalue, SourceLocation Loc);
   3779 
   3780   /// EmitStoreOfScalar - Store a scalar value to an address, taking
   3781   /// care to appropriately convert from the memory representation to
   3782   /// the LLVM value representation.
   3783   void EmitStoreOfScalar(llvm::Value *Value, Address Addr,
   3784                          bool Volatile, QualType Ty,
   3785                          AlignmentSource Source = AlignmentSource::Type,
   3786                          bool isInit = false, bool isNontemporal = false) {
   3787     EmitStoreOfScalar(Value, Addr, Volatile, Ty, LValueBaseInfo(Source),
   3788                       CGM.getTBAAAccessInfo(Ty), isInit, isNontemporal);
   3789   }
   3790 
   3791   void EmitStoreOfScalar(llvm::Value *Value, Address Addr,
   3792                          bool Volatile, QualType Ty,
   3793                          LValueBaseInfo BaseInfo, TBAAAccessInfo TBAAInfo,
   3794                          bool isInit = false, bool isNontemporal = false);
   3795 
   3796   /// EmitStoreOfScalar - Store a scalar value to an address, taking
   3797   /// care to appropriately convert from the memory representation to
   3798   /// the LLVM value representation.  The l-value must be a simple
   3799   /// l-value.  The isInit flag indicates whether this is an initialization.
   3800   /// If so, atomic qualifiers are ignored and the store is always non-atomic.
   3801   void EmitStoreOfScalar(llvm::Value *value, LValue lvalue, bool isInit=false);
   3802 
   3803   /// EmitLoadOfLValue - Given an expression that represents a value lvalue,
   3804   /// this method emits the address of the lvalue, then loads the result as an
   3805   /// rvalue, returning the rvalue.
   3806   RValue EmitLoadOfLValue(LValue V, SourceLocation Loc);
   3807   RValue EmitLoadOfExtVectorElementLValue(LValue V);
   3808   RValue EmitLoadOfBitfieldLValue(LValue LV, SourceLocation Loc);
   3809   RValue EmitLoadOfGlobalRegLValue(LValue LV);
   3810 
   3811   /// EmitStoreThroughLValue - Store the specified rvalue into the specified
   3812   /// lvalue, where both are guaranteed to the have the same type, and that type
   3813   /// is 'Ty'.
   3814   void EmitStoreThroughLValue(RValue Src, LValue Dst, bool isInit = false);
   3815   void EmitStoreThroughExtVectorComponentLValue(RValue Src, LValue Dst);
   3816   void EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst);
   3817 
   3818   /// EmitStoreThroughBitfieldLValue - Store Src into Dst with same constraints
   3819   /// as EmitStoreThroughLValue.
   3820   ///
   3821   /// \param Result [out] - If non-null, this will be set to a Value* for the
   3822   /// bit-field contents after the store, appropriate for use as the result of
   3823   /// an assignment to the bit-field.
   3824   void EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
   3825                                       llvm::Value **Result=nullptr);
   3826 
   3827   /// Emit an l-value for an assignment (simple or compound) of complex type.
   3828   LValue EmitComplexAssignmentLValue(const BinaryOperator *E);
   3829   LValue EmitComplexCompoundAssignmentLValue(const CompoundAssignOperator *E);
   3830   LValue EmitScalarCompoundAssignWithComplex(const CompoundAssignOperator *E,
   3831                                              llvm::Value *&Result);
   3832 
   3833   // Note: only available for agg return types
   3834   LValue EmitBinaryOperatorLValue(const BinaryOperator *E);
   3835   LValue EmitCompoundAssignmentLValue(const CompoundAssignOperator *E);
   3836   // Note: only available for agg return types
   3837   LValue EmitCallExprLValue(const CallExpr *E);
   3838   // Note: only available for agg return types
   3839   LValue EmitVAArgExprLValue(const VAArgExpr *E);
   3840   LValue EmitDeclRefLValue(const DeclRefExpr *E);
   3841   LValue EmitStringLiteralLValue(const StringLiteral *E);
   3842   LValue EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E);
   3843   LValue EmitPredefinedLValue(const PredefinedExpr *E);
   3844   LValue EmitUnaryOpLValue(const UnaryOperator *E);
   3845   LValue EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
   3846                                 bool Accessed = false);
   3847   LValue EmitMatrixSubscriptExpr(const MatrixSubscriptExpr *E);
   3848   LValue EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
   3849                                  bool IsLowerBound = true);
   3850   LValue EmitExtVectorElementExpr(const ExtVectorElementExpr *E);
   3851   LValue EmitMemberExpr(const MemberExpr *E);
   3852   LValue EmitObjCIsaExpr(const ObjCIsaExpr *E);
   3853   LValue EmitCompoundLiteralLValue(const CompoundLiteralExpr *E);
   3854   LValue EmitInitListLValue(const InitListExpr *E);
   3855   LValue EmitConditionalOperatorLValue(const AbstractConditionalOperator *E);
   3856   LValue EmitCastLValue(const CastExpr *E);
   3857   LValue EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *E);
   3858   LValue EmitOpaqueValueLValue(const OpaqueValueExpr *e);
   3859 
   3860   Address EmitExtVectorElementLValue(LValue V);
   3861 
   3862   RValue EmitRValueForField(LValue LV, const FieldDecl *FD, SourceLocation Loc);
   3863 
   3864   Address EmitArrayToPointerDecay(const Expr *Array,
   3865                                   LValueBaseInfo *BaseInfo = nullptr,
   3866                                   TBAAAccessInfo *TBAAInfo = nullptr);
   3867 
   3868   class ConstantEmission {
   3869     llvm::PointerIntPair<llvm::Constant*, 1, bool> ValueAndIsReference;
   3870     ConstantEmission(llvm::Constant *C, bool isReference)
   3871       : ValueAndIsReference(C, isReference) {}
   3872   public:
   3873     ConstantEmission() {}
   3874     static ConstantEmission forReference(llvm::Constant *C) {
   3875       return ConstantEmission(C, true);
   3876     }
   3877     static ConstantEmission forValue(llvm::Constant *C) {
   3878       return ConstantEmission(C, false);
   3879     }
   3880 
   3881     explicit operator bool() const {
   3882       return ValueAndIsReference.getOpaqueValue() != nullptr;
   3883     }
   3884 
   3885     bool isReference() const { return ValueAndIsReference.getInt(); }
   3886     LValue getReferenceLValue(CodeGenFunction &CGF, Expr *refExpr) const {
   3887       assert(isReference());
   3888       return CGF.MakeNaturalAlignAddrLValue(ValueAndIsReference.getPointer(),
   3889                                             refExpr->getType());
   3890     }
   3891 
   3892     llvm::Constant *getValue() const {
   3893       assert(!isReference());
   3894       return ValueAndIsReference.getPointer();
   3895     }
   3896   };
   3897 
   3898   ConstantEmission tryEmitAsConstant(DeclRefExpr *refExpr);
   3899   ConstantEmission tryEmitAsConstant(const MemberExpr *ME);
   3900   llvm::Value *emitScalarConstant(const ConstantEmission &Constant, Expr *E);
   3901 
   3902   RValue EmitPseudoObjectRValue(const PseudoObjectExpr *e,
   3903                                 AggValueSlot slot = AggValueSlot::ignored());
   3904   LValue EmitPseudoObjectLValue(const PseudoObjectExpr *e);
   3905 
   3906   llvm::Value *EmitIvarOffset(const ObjCInterfaceDecl *Interface,
   3907                               const ObjCIvarDecl *Ivar);
   3908   LValue EmitLValueForField(LValue Base, const FieldDecl* Field);
   3909   LValue EmitLValueForLambdaField(const FieldDecl *Field);
   3910 
   3911   /// EmitLValueForFieldInitialization - Like EmitLValueForField, except that
   3912   /// if the Field is a reference, this will return the address of the reference
   3913   /// and not the address of the value stored in the reference.
   3914   LValue EmitLValueForFieldInitialization(LValue Base,
   3915                                           const FieldDecl* Field);
   3916 
   3917   LValue EmitLValueForIvar(QualType ObjectTy,
   3918                            llvm::Value* Base, const ObjCIvarDecl *Ivar,
   3919                            unsigned CVRQualifiers);
   3920 
   3921   LValue EmitCXXConstructLValue(const CXXConstructExpr *E);
   3922   LValue EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E);
   3923   LValue EmitCXXTypeidLValue(const CXXTypeidExpr *E);
   3924   LValue EmitCXXUuidofLValue(const CXXUuidofExpr *E);
   3925 
   3926   LValue EmitObjCMessageExprLValue(const ObjCMessageExpr *E);
   3927   LValue EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E);
   3928   LValue EmitStmtExprLValue(const StmtExpr *E);
   3929   LValue EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E);
   3930   LValue EmitObjCSelectorLValue(const ObjCSelectorExpr *E);
   3931   void   EmitDeclRefExprDbgValue(const DeclRefExpr *E, const APValue &Init);
   3932 
   3933   //===--------------------------------------------------------------------===//
   3934   //                         Scalar Expression Emission
   3935   //===--------------------------------------------------------------------===//
   3936 
   3937   /// EmitCall - Generate a call of the given function, expecting the given
   3938   /// result type, and using the given argument list which specifies both the
   3939   /// LLVM arguments and the types they were derived from.
   3940   RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee,
   3941                   ReturnValueSlot ReturnValue, const CallArgList &Args,
   3942                   llvm::CallBase **callOrInvoke, bool IsMustTail,
   3943                   SourceLocation Loc);
   3944   RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee,
   3945                   ReturnValueSlot ReturnValue, const CallArgList &Args,
   3946                   llvm::CallBase **callOrInvoke = nullptr,
   3947                   bool IsMustTail = false) {
   3948     return EmitCall(CallInfo, Callee, ReturnValue, Args, callOrInvoke,
   3949                     IsMustTail, SourceLocation());
   3950   }
   3951   RValue EmitCall(QualType FnType, const CGCallee &Callee, const CallExpr *E,
   3952                   ReturnValueSlot ReturnValue, llvm::Value *Chain = nullptr);
   3953   RValue EmitCallExpr(const CallExpr *E,
   3954                       ReturnValueSlot ReturnValue = ReturnValueSlot());
   3955   RValue EmitSimpleCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue);
   3956   CGCallee EmitCallee(const Expr *E);
   3957 
   3958   void checkTargetFeatures(const CallExpr *E, const FunctionDecl *TargetDecl);
   3959   void checkTargetFeatures(SourceLocation Loc, const FunctionDecl *TargetDecl);
   3960 
   3961   llvm::CallInst *EmitRuntimeCall(llvm::FunctionCallee callee,
   3962                                   const Twine &name = "");
   3963   llvm::CallInst *EmitRuntimeCall(llvm::FunctionCallee callee,
   3964                                   ArrayRef<llvm::Value *> args,
   3965                                   const Twine &name = "");
   3966   llvm::CallInst *EmitNounwindRuntimeCall(llvm::FunctionCallee callee,
   3967                                           const Twine &name = "");
   3968   llvm::CallInst *EmitNounwindRuntimeCall(llvm::FunctionCallee callee,
   3969                                           ArrayRef<llvm::Value *> args,
   3970                                           const Twine &name = "");
   3971 
   3972   SmallVector<llvm::OperandBundleDef, 1>
   3973   getBundlesForFunclet(llvm::Value *Callee);
   3974 
   3975   llvm::CallBase *EmitCallOrInvoke(llvm::FunctionCallee Callee,
   3976                                    ArrayRef<llvm::Value *> Args,
   3977                                    const Twine &Name = "");
   3978   llvm::CallBase *EmitRuntimeCallOrInvoke(llvm::FunctionCallee callee,
   3979                                           ArrayRef<llvm::Value *> args,
   3980                                           const Twine &name = "");
   3981   llvm::CallBase *EmitRuntimeCallOrInvoke(llvm::FunctionCallee callee,
   3982                                           const Twine &name = "");
   3983   void EmitNoreturnRuntimeCallOrInvoke(llvm::FunctionCallee callee,
   3984                                        ArrayRef<llvm::Value *> args);
   3985 
   3986   CGCallee BuildAppleKextVirtualCall(const CXXMethodDecl *MD,
   3987                                      NestedNameSpecifier *Qual,
   3988                                      llvm::Type *Ty);
   3989 
   3990   CGCallee BuildAppleKextVirtualDestructorCall(const CXXDestructorDecl *DD,
   3991                                                CXXDtorType Type,
   3992                                                const CXXRecordDecl *RD);
   3993 
   3994   // Return the copy constructor name with the prefix "__copy_constructor_"
   3995   // removed.
   3996   static std::string getNonTrivialCopyConstructorStr(QualType QT,
   3997                                                      CharUnits Alignment,
   3998                                                      bool IsVolatile,
   3999                                                      ASTContext &Ctx);
   4000 
   4001   // Return the destructor name with the prefix "__destructor_" removed.
   4002   static std::string getNonTrivialDestructorStr(QualType QT,
   4003                                                 CharUnits Alignment,
   4004                                                 bool IsVolatile,
   4005                                                 ASTContext &Ctx);
   4006 
   4007   // These functions emit calls to the special functions of non-trivial C
   4008   // structs.
   4009   void defaultInitNonTrivialCStructVar(LValue Dst);
   4010   void callCStructDefaultConstructor(LValue Dst);
   4011   void callCStructDestructor(LValue Dst);
   4012   void callCStructCopyConstructor(LValue Dst, LValue Src);
   4013   void callCStructMoveConstructor(LValue Dst, LValue Src);
   4014   void callCStructCopyAssignmentOperator(LValue Dst, LValue Src);
   4015   void callCStructMoveAssignmentOperator(LValue Dst, LValue Src);
   4016 
   4017   RValue
   4018   EmitCXXMemberOrOperatorCall(const CXXMethodDecl *Method,
   4019                               const CGCallee &Callee,
   4020                               ReturnValueSlot ReturnValue, llvm::Value *This,
   4021                               llvm::Value *ImplicitParam,
   4022                               QualType ImplicitParamTy, const CallExpr *E,
   4023                               CallArgList *RtlArgs);
   4024   RValue EmitCXXDestructorCall(GlobalDecl Dtor, const CGCallee &Callee,
   4025                                llvm::Value *This, QualType ThisTy,
   4026                                llvm::Value *ImplicitParam,
   4027                                QualType ImplicitParamTy, const CallExpr *E);
   4028   RValue EmitCXXMemberCallExpr(const CXXMemberCallExpr *E,
   4029                                ReturnValueSlot ReturnValue);
   4030   RValue EmitCXXMemberOrOperatorMemberCallExpr(const CallExpr *CE,
   4031                                                const CXXMethodDecl *MD,
   4032                                                ReturnValueSlot ReturnValue,
   4033                                                bool HasQualifier,
   4034                                                NestedNameSpecifier *Qualifier,
   4035                                                bool IsArrow, const Expr *Base);
   4036   // Compute the object pointer.
   4037   Address EmitCXXMemberDataPointerAddress(const Expr *E, Address base,
   4038                                           llvm::Value *memberPtr,
   4039                                           const MemberPointerType *memberPtrType,
   4040                                           LValueBaseInfo *BaseInfo = nullptr,
   4041                                           TBAAAccessInfo *TBAAInfo = nullptr);
   4042   RValue EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
   4043                                       ReturnValueSlot ReturnValue);
   4044 
   4045   RValue EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E,
   4046                                        const CXXMethodDecl *MD,
   4047                                        ReturnValueSlot ReturnValue);
   4048   RValue EmitCXXPseudoDestructorExpr(const CXXPseudoDestructorExpr *E);
   4049 
   4050   RValue EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E,
   4051                                 ReturnValueSlot ReturnValue);
   4052 
   4053   RValue EmitNVPTXDevicePrintfCallExpr(const CallExpr *E,
   4054                                        ReturnValueSlot ReturnValue);
   4055   RValue EmitAMDGPUDevicePrintfCallExpr(const CallExpr *E,
   4056                                         ReturnValueSlot ReturnValue);
   4057 
   4058   RValue EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
   4059                          const CallExpr *E, ReturnValueSlot ReturnValue);
   4060 
   4061   RValue emitRotate(const CallExpr *E, bool IsRotateRight);
   4062 
   4063   /// Emit IR for __builtin_os_log_format.
   4064   RValue emitBuiltinOSLogFormat(const CallExpr &E);
   4065 
   4066   /// Emit IR for __builtin_is_aligned.
   4067   RValue EmitBuiltinIsAligned(const CallExpr *E);
   4068   /// Emit IR for __builtin_align_up/__builtin_align_down.
   4069   RValue EmitBuiltinAlignTo(const CallExpr *E, bool AlignUp);
   4070 
   4071   llvm::Function *generateBuiltinOSLogHelperFunction(
   4072       const analyze_os_log::OSLogBufferLayout &Layout,
   4073       CharUnits BufferAlignment);
   4074 
   4075   RValue EmitBlockCallExpr(const CallExpr *E, ReturnValueSlot ReturnValue);
   4076 
   4077   /// EmitTargetBuiltinExpr - Emit the given builtin call. Returns 0 if the call
   4078   /// is unhandled by the current target.
   4079   llvm::Value *EmitTargetBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
   4080                                      ReturnValueSlot ReturnValue);
   4081 
   4082   llvm::Value *EmitAArch64CompareBuiltinExpr(llvm::Value *Op, llvm::Type *Ty,
   4083                                              const llvm::CmpInst::Predicate Fp,
   4084                                              const llvm::CmpInst::Predicate Ip,
   4085                                              const llvm::Twine &Name = "");
   4086   llvm::Value *EmitARMBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
   4087                                   ReturnValueSlot ReturnValue,
   4088                                   llvm::Triple::ArchType Arch);
   4089   llvm::Value *EmitARMMVEBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
   4090                                      ReturnValueSlot ReturnValue,
   4091                                      llvm::Triple::ArchType Arch);
   4092   llvm::Value *EmitARMCDEBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
   4093                                      ReturnValueSlot ReturnValue,
   4094                                      llvm::Triple::ArchType Arch);
   4095   llvm::Value *EmitCMSEClearRecord(llvm::Value *V, llvm::IntegerType *ITy,
   4096                                    QualType RTy);
   4097   llvm::Value *EmitCMSEClearRecord(llvm::Value *V, llvm::ArrayType *ATy,
   4098                                    QualType RTy);
   4099 
   4100   llvm::Value *EmitCommonNeonBuiltinExpr(unsigned BuiltinID,
   4101                                          unsigned LLVMIntrinsic,
   4102                                          unsigned AltLLVMIntrinsic,
   4103                                          const char *NameHint,
   4104                                          unsigned Modifier,
   4105                                          const CallExpr *E,
   4106                                          SmallVectorImpl<llvm::Value *> &Ops,
   4107                                          Address PtrOp0, Address PtrOp1,
   4108                                          llvm::Triple::ArchType Arch);
   4109 
   4110   llvm::Function *LookupNeonLLVMIntrinsic(unsigned IntrinsicID,
   4111                                           unsigned Modifier, llvm::Type *ArgTy,
   4112                                           const CallExpr *E);
   4113   llvm::Value *EmitNeonCall(llvm::Function *F,
   4114                             SmallVectorImpl<llvm::Value*> &O,
   4115                             const char *name,
   4116                             unsigned shift = 0, bool rightshift = false);
   4117   llvm::Value *EmitNeonSplat(llvm::Value *V, llvm::Constant *Idx,
   4118                              const llvm::ElementCount &Count);
   4119   llvm::Value *EmitNeonSplat(llvm::Value *V, llvm::Constant *Idx);
   4120   llvm::Value *EmitNeonShiftVector(llvm::Value *V, llvm::Type *Ty,
   4121                                    bool negateForRightShift);
   4122   llvm::Value *EmitNeonRShiftImm(llvm::Value *Vec, llvm::Value *Amt,
   4123                                  llvm::Type *Ty, bool usgn, const char *name);
   4124   llvm::Value *vectorWrapScalar16(llvm::Value *Op);
   4125   /// SVEBuiltinMemEltTy - Returns the memory element type for this memory
   4126   /// access builtin.  Only required if it can't be inferred from the base
   4127   /// pointer operand.
   4128   llvm::Type *SVEBuiltinMemEltTy(SVETypeFlags TypeFlags);
   4129 
   4130   SmallVector<llvm::Type *, 2> getSVEOverloadTypes(SVETypeFlags TypeFlags,
   4131                                                    llvm::Type *ReturnType,
   4132                                                    ArrayRef<llvm::Value *> Ops);
   4133   llvm::Type *getEltType(SVETypeFlags TypeFlags);
   4134   llvm::ScalableVectorType *getSVEType(const SVETypeFlags &TypeFlags);
   4135   llvm::ScalableVectorType *getSVEPredType(SVETypeFlags TypeFlags);
   4136   llvm::Value *EmitSVEAllTruePred(SVETypeFlags TypeFlags);
   4137   llvm::Value *EmitSVEDupX(llvm::Value *Scalar);
   4138   llvm::Value *EmitSVEDupX(llvm::Value *Scalar, llvm::Type *Ty);
   4139   llvm::Value *EmitSVEReinterpret(llvm::Value *Val, llvm::Type *Ty);
   4140   llvm::Value *EmitSVEPMull(SVETypeFlags TypeFlags,
   4141                             llvm::SmallVectorImpl<llvm::Value *> &Ops,
   4142                             unsigned BuiltinID);
   4143   llvm::Value *EmitSVEMovl(SVETypeFlags TypeFlags,
   4144                            llvm::ArrayRef<llvm::Value *> Ops,
   4145                            unsigned BuiltinID);
   4146   llvm::Value *EmitSVEPredicateCast(llvm::Value *Pred,
   4147                                     llvm::ScalableVectorType *VTy);
   4148   llvm::Value *EmitSVEGatherLoad(SVETypeFlags TypeFlags,
   4149                                  llvm::SmallVectorImpl<llvm::Value *> &Ops,
   4150                                  unsigned IntID);
   4151   llvm::Value *EmitSVEScatterStore(SVETypeFlags TypeFlags,
   4152                                    llvm::SmallVectorImpl<llvm::Value *> &Ops,
   4153                                    unsigned IntID);
   4154   llvm::Value *EmitSVEMaskedLoad(const CallExpr *, llvm::Type *ReturnTy,
   4155                                  SmallVectorImpl<llvm::Value *> &Ops,
   4156                                  unsigned BuiltinID, bool IsZExtReturn);
   4157   llvm::Value *EmitSVEMaskedStore(const CallExpr *,
   4158                                   SmallVectorImpl<llvm::Value *> &Ops,
   4159                                   unsigned BuiltinID);
   4160   llvm::Value *EmitSVEPrefetchLoad(SVETypeFlags TypeFlags,
   4161                                    SmallVectorImpl<llvm::Value *> &Ops,
   4162                                    unsigned BuiltinID);
   4163   llvm::Value *EmitSVEGatherPrefetch(SVETypeFlags TypeFlags,
   4164                                      SmallVectorImpl<llvm::Value *> &Ops,
   4165                                      unsigned IntID);
   4166   llvm::Value *EmitSVEStructLoad(SVETypeFlags TypeFlags,
   4167                                  SmallVectorImpl<llvm::Value *> &Ops, unsigned IntID);
   4168   llvm::Value *EmitSVEStructStore(SVETypeFlags TypeFlags,
   4169                                   SmallVectorImpl<llvm::Value *> &Ops,
   4170                                   unsigned IntID);
   4171   llvm::Value *EmitAArch64SVEBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   4172 
   4173   llvm::Value *EmitAArch64BuiltinExpr(unsigned BuiltinID, const CallExpr *E,
   4174                                       llvm::Triple::ArchType Arch);
   4175   llvm::Value *EmitBPFBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   4176 
   4177   llvm::Value *BuildVector(ArrayRef<llvm::Value*> Ops);
   4178   llvm::Value *EmitX86BuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   4179   llvm::Value *EmitPPCBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   4180   llvm::Value *EmitAMDGPUBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   4181   llvm::Value *EmitSystemZBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   4182   llvm::Value *EmitNVPTXBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   4183   llvm::Value *EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
   4184                                           const CallExpr *E);
   4185   llvm::Value *EmitHexagonBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   4186   llvm::Value *EmitRISCVBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
   4187                                     ReturnValueSlot ReturnValue);
   4188   bool ProcessOrderScopeAMDGCN(llvm::Value *Order, llvm::Value *Scope,
   4189                                llvm::AtomicOrdering &AO,
   4190                                llvm::SyncScope::ID &SSID);
   4191 
   4192   enum class MSVCIntrin;
   4193   llvm::Value *EmitMSVCBuiltinExpr(MSVCIntrin BuiltinID, const CallExpr *E);
   4194 
   4195   llvm::Value *EmitBuiltinAvailable(const VersionTuple &Version);
   4196 
   4197   llvm::Value *EmitObjCProtocolExpr(const ObjCProtocolExpr *E);
   4198   llvm::Value *EmitObjCStringLiteral(const ObjCStringLiteral *E);
   4199   llvm::Value *EmitObjCBoxedExpr(const ObjCBoxedExpr *E);
   4200   llvm::Value *EmitObjCArrayLiteral(const ObjCArrayLiteral *E);
   4201   llvm::Value *EmitObjCDictionaryLiteral(const ObjCDictionaryLiteral *E);
   4202   llvm::Value *EmitObjCCollectionLiteral(const Expr *E,
   4203                                 const ObjCMethodDecl *MethodWithObjects);
   4204   llvm::Value *EmitObjCSelectorExpr(const ObjCSelectorExpr *E);
   4205   RValue EmitObjCMessageExpr(const ObjCMessageExpr *E,
   4206                              ReturnValueSlot Return = ReturnValueSlot());
   4207 
   4208   /// Retrieves the default cleanup kind for an ARC cleanup.
   4209   /// Except under -fobjc-arc-eh, ARC cleanups are normal-only.
   4210   CleanupKind getARCCleanupKind() {
   4211     return CGM.getCodeGenOpts().ObjCAutoRefCountExceptions
   4212              ? NormalAndEHCleanup : NormalCleanup;
   4213   }
   4214 
   4215   // ARC primitives.
   4216   void EmitARCInitWeak(Address addr, llvm::Value *value);
   4217   void EmitARCDestroyWeak(Address addr);
   4218   llvm::Value *EmitARCLoadWeak(Address addr);
   4219   llvm::Value *EmitARCLoadWeakRetained(Address addr);
   4220   llvm::Value *EmitARCStoreWeak(Address addr, llvm::Value *value, bool ignored);
   4221   void emitARCCopyAssignWeak(QualType Ty, Address DstAddr, Address SrcAddr);
   4222   void emitARCMoveAssignWeak(QualType Ty, Address DstAddr, Address SrcAddr);
   4223   void EmitARCCopyWeak(Address dst, Address src);
   4224   void EmitARCMoveWeak(Address dst, Address src);
   4225   llvm::Value *EmitARCRetainAutorelease(QualType type, llvm::Value *value);
   4226   llvm::Value *EmitARCRetainAutoreleaseNonBlock(llvm::Value *value);
   4227   llvm::Value *EmitARCStoreStrong(LValue lvalue, llvm::Value *value,
   4228                                   bool resultIgnored);
   4229   llvm::Value *EmitARCStoreStrongCall(Address addr, llvm::Value *value,
   4230                                       bool resultIgnored);
   4231   llvm::Value *EmitARCRetain(QualType type, llvm::Value *value);
   4232   llvm::Value *EmitARCRetainNonBlock(llvm::Value *value);
   4233   llvm::Value *EmitARCRetainBlock(llvm::Value *value, bool mandatory);
   4234   void EmitARCDestroyStrong(Address addr, ARCPreciseLifetime_t precise);
   4235   void EmitARCRelease(llvm::Value *value, ARCPreciseLifetime_t precise);
   4236   llvm::Value *EmitARCAutorelease(llvm::Value *value);
   4237   llvm::Value *EmitARCAutoreleaseReturnValue(llvm::Value *value);
   4238   llvm::Value *EmitARCRetainAutoreleaseReturnValue(llvm::Value *value);
   4239   llvm::Value *EmitARCRetainAutoreleasedReturnValue(llvm::Value *value);
   4240   llvm::Value *EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value *value);
   4241 
   4242   llvm::Value *EmitObjCAutorelease(llvm::Value *value, llvm::Type *returnType);
   4243   llvm::Value *EmitObjCRetainNonBlock(llvm::Value *value,
   4244                                       llvm::Type *returnType);
   4245   void EmitObjCRelease(llvm::Value *value, ARCPreciseLifetime_t precise);
   4246 
   4247   std::pair<LValue,llvm::Value*>
   4248   EmitARCStoreAutoreleasing(const BinaryOperator *e);
   4249   std::pair<LValue,llvm::Value*>
   4250   EmitARCStoreStrong(const BinaryOperator *e, bool ignored);
   4251   std::pair<LValue,llvm::Value*>
   4252   EmitARCStoreUnsafeUnretained(const BinaryOperator *e, bool ignored);
   4253 
   4254   llvm::Value *EmitObjCAlloc(llvm::Value *value,
   4255                              llvm::Type *returnType);
   4256   llvm::Value *EmitObjCAllocWithZone(llvm::Value *value,
   4257                                      llvm::Type *returnType);
   4258   llvm::Value *EmitObjCAllocInit(llvm::Value *value, llvm::Type *resultType);
   4259 
   4260   llvm::Value *EmitObjCThrowOperand(const Expr *expr);
   4261   llvm::Value *EmitObjCConsumeObject(QualType T, llvm::Value *Ptr);
   4262   llvm::Value *EmitObjCExtendObjectLifetime(QualType T, llvm::Value *Ptr);
   4263 
   4264   llvm::Value *EmitARCExtendBlockObject(const Expr *expr);
   4265   llvm::Value *EmitARCReclaimReturnedObject(const Expr *e,
   4266                                             bool allowUnsafeClaim);
   4267   llvm::Value *EmitARCRetainScalarExpr(const Expr *expr);
   4268   llvm::Value *EmitARCRetainAutoreleaseScalarExpr(const Expr *expr);
   4269   llvm::Value *EmitARCUnsafeUnretainedScalarExpr(const Expr *expr);
   4270 
   4271   void EmitARCIntrinsicUse(ArrayRef<llvm::Value*> values);
   4272 
   4273   void EmitARCNoopIntrinsicUse(ArrayRef<llvm::Value *> values);
   4274 
   4275   static Destroyer destroyARCStrongImprecise;
   4276   static Destroyer destroyARCStrongPrecise;
   4277   static Destroyer destroyARCWeak;
   4278   static Destroyer emitARCIntrinsicUse;
   4279   static Destroyer destroyNonTrivialCStruct;
   4280 
   4281   void EmitObjCAutoreleasePoolPop(llvm::Value *Ptr);
   4282   llvm::Value *EmitObjCAutoreleasePoolPush();
   4283   llvm::Value *EmitObjCMRRAutoreleasePoolPush();
   4284   void EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr);
   4285   void EmitObjCMRRAutoreleasePoolPop(llvm::Value *Ptr);
   4286 
   4287   /// Emits a reference binding to the passed in expression.
   4288   RValue EmitReferenceBindingToExpr(const Expr *E);
   4289 
   4290   //===--------------------------------------------------------------------===//
   4291   //                           Expression Emission
   4292   //===--------------------------------------------------------------------===//
   4293 
   4294   // Expressions are broken into three classes: scalar, complex, aggregate.
   4295 
   4296   /// EmitScalarExpr - Emit the computation of the specified expression of LLVM
   4297   /// scalar type, returning the result.
   4298   llvm::Value *EmitScalarExpr(const Expr *E , bool IgnoreResultAssign = false);
   4299 
   4300   /// Emit a conversion from the specified type to the specified destination
   4301   /// type, both of which are LLVM scalar types.
   4302   llvm::Value *EmitScalarConversion(llvm::Value *Src, QualType SrcTy,
   4303                                     QualType DstTy, SourceLocation Loc);
   4304 
   4305   /// Emit a conversion from the specified complex type to the specified
   4306   /// destination type, where the destination type is an LLVM scalar type.
   4307   llvm::Value *EmitComplexToScalarConversion(ComplexPairTy Src, QualType SrcTy,
   4308                                              QualType DstTy,
   4309                                              SourceLocation Loc);
   4310 
   4311   /// EmitAggExpr - Emit the computation of the specified expression
   4312   /// of aggregate type.  The result is computed into the given slot,
   4313   /// which may be null to indicate that the value is not needed.
   4314   void EmitAggExpr(const Expr *E, AggValueSlot AS);
   4315 
   4316   /// EmitAggExprToLValue - Emit the computation of the specified expression of
   4317   /// aggregate type into a temporary LValue.
   4318   LValue EmitAggExprToLValue(const Expr *E);
   4319 
   4320   /// Build all the stores needed to initialize an aggregate at Dest with the
   4321   /// value Val.
   4322   void EmitAggregateStore(llvm::Value *Val, Address Dest, bool DestIsVolatile);
   4323 
   4324   /// EmitExtendGCLifetime - Given a pointer to an Objective-C object,
   4325   /// make sure it survives garbage collection until this point.
   4326   void EmitExtendGCLifetime(llvm::Value *object);
   4327 
   4328   /// EmitComplexExpr - Emit the computation of the specified expression of
   4329   /// complex type, returning the result.
   4330   ComplexPairTy EmitComplexExpr(const Expr *E,
   4331                                 bool IgnoreReal = false,
   4332                                 bool IgnoreImag = false);
   4333 
   4334   /// EmitComplexExprIntoLValue - Emit the given expression of complex
   4335   /// type and place its result into the specified l-value.
   4336   void EmitComplexExprIntoLValue(const Expr *E, LValue dest, bool isInit);
   4337 
   4338   /// EmitStoreOfComplex - Store a complex number into the specified l-value.
   4339   void EmitStoreOfComplex(ComplexPairTy V, LValue dest, bool isInit);
   4340 
   4341   /// EmitLoadOfComplex - Load a complex number from the specified l-value.
   4342   ComplexPairTy EmitLoadOfComplex(LValue src, SourceLocation loc);
   4343 
   4344   Address emitAddrOfRealComponent(Address complex, QualType complexType);
   4345   Address emitAddrOfImagComponent(Address complex, QualType complexType);
   4346 
   4347   /// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
   4348   /// global variable that has already been created for it.  If the initializer
   4349   /// has a different type than GV does, this may free GV and return a different
   4350   /// one.  Otherwise it just returns GV.
   4351   llvm::GlobalVariable *
   4352   AddInitializerToStaticVarDecl(const VarDecl &D,
   4353                                 llvm::GlobalVariable *GV);
   4354 
   4355   // Emit an @llvm.invariant.start call for the given memory region.
   4356   void EmitInvariantStart(llvm::Constant *Addr, CharUnits Size);
   4357 
   4358   /// EmitCXXGlobalVarDeclInit - Create the initializer for a C++
   4359   /// variable with global storage.
   4360   void EmitCXXGlobalVarDeclInit(const VarDecl &D, llvm::Constant *DeclPtr,
   4361                                 bool PerformInit);
   4362 
   4363   llvm::Function *createAtExitStub(const VarDecl &VD, llvm::FunctionCallee Dtor,
   4364                                    llvm::Constant *Addr);
   4365 
   4366   /// Call atexit() with a function that passes the given argument to
   4367   /// the given function.
   4368   void registerGlobalDtorWithAtExit(const VarDecl &D, llvm::FunctionCallee fn,
   4369                                     llvm::Constant *addr);
   4370 
   4371   /// Call atexit() with function dtorStub.
   4372   void registerGlobalDtorWithAtExit(llvm::Constant *dtorStub);
   4373 
   4374   /// Call unatexit() with function dtorStub.
   4375   llvm::Value *unregisterGlobalDtorWithUnAtExit(llvm::Constant *dtorStub);
   4376 
   4377   /// Emit code in this function to perform a guarded variable
   4378   /// initialization.  Guarded initializations are used when it's not
   4379   /// possible to prove that an initialization will be done exactly
   4380   /// once, e.g. with a static local variable or a static data member
   4381   /// of a class template.
   4382   void EmitCXXGuardedInit(const VarDecl &D, llvm::GlobalVariable *DeclPtr,
   4383                           bool PerformInit);
   4384 
   4385   enum class GuardKind { VariableGuard, TlsGuard };
   4386 
   4387   /// Emit a branch to select whether or not to perform guarded initialization.
   4388   void EmitCXXGuardedInitBranch(llvm::Value *NeedsInit,
   4389                                 llvm::BasicBlock *InitBlock,
   4390                                 llvm::BasicBlock *NoInitBlock,
   4391                                 GuardKind Kind, const VarDecl *D);
   4392 
   4393   /// GenerateCXXGlobalInitFunc - Generates code for initializing global
   4394   /// variables.
   4395   void
   4396   GenerateCXXGlobalInitFunc(llvm::Function *Fn,
   4397                             ArrayRef<llvm::Function *> CXXThreadLocals,
   4398                             ConstantAddress Guard = ConstantAddress::invalid());
   4399 
   4400   /// GenerateCXXGlobalCleanUpFunc - Generates code for cleaning up global
   4401   /// variables.
   4402   void GenerateCXXGlobalCleanUpFunc(
   4403       llvm::Function *Fn,
   4404       ArrayRef<std::tuple<llvm::FunctionType *, llvm::WeakTrackingVH,
   4405                           llvm::Constant *>>
   4406           DtorsOrStermFinalizers);
   4407 
   4408   void GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn,
   4409                                         const VarDecl *D,
   4410                                         llvm::GlobalVariable *Addr,
   4411                                         bool PerformInit);
   4412 
   4413   void EmitCXXConstructExpr(const CXXConstructExpr *E, AggValueSlot Dest);
   4414 
   4415   void EmitSynthesizedCXXCopyCtor(Address Dest, Address Src, const Expr *Exp);
   4416 
   4417   void EmitCXXThrowExpr(const CXXThrowExpr *E, bool KeepInsertionPoint = true);
   4418 
   4419   RValue EmitAtomicExpr(AtomicExpr *E);
   4420 
   4421   //===--------------------------------------------------------------------===//
   4422   //                         Annotations Emission
   4423   //===--------------------------------------------------------------------===//
   4424 
   4425   /// Emit an annotation call (intrinsic).
   4426   llvm::Value *EmitAnnotationCall(llvm::Function *AnnotationFn,
   4427                                   llvm::Value *AnnotatedVal,
   4428                                   StringRef AnnotationStr,
   4429                                   SourceLocation Location,
   4430                                   const AnnotateAttr *Attr);
   4431 
   4432   /// Emit local annotations for the local variable V, declared by D.
   4433   void EmitVarAnnotations(const VarDecl *D, llvm::Value *V);
   4434 
   4435   /// Emit field annotations for the given field & value. Returns the
   4436   /// annotation result.
   4437   Address EmitFieldAnnotations(const FieldDecl *D, Address V);
   4438 
   4439   //===--------------------------------------------------------------------===//
   4440   //                             Internal Helpers
   4441   //===--------------------------------------------------------------------===//
   4442 
   4443   /// ContainsLabel - Return true if the statement contains a label in it.  If
   4444   /// this statement is not executed normally, it not containing a label means
   4445   /// that we can just remove the code.
   4446   static bool ContainsLabel(const Stmt *S, bool IgnoreCaseStmts = false);
   4447 
   4448   /// containsBreak - Return true if the statement contains a break out of it.
   4449   /// If the statement (recursively) contains a switch or loop with a break
   4450   /// inside of it, this is fine.
   4451   static bool containsBreak(const Stmt *S);
   4452 
   4453   /// Determine if the given statement might introduce a declaration into the
   4454   /// current scope, by being a (possibly-labelled) DeclStmt.
   4455   static bool mightAddDeclToScope(const Stmt *S);
   4456 
   4457   /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
   4458   /// to a constant, or if it does but contains a label, return false.  If it
   4459   /// constant folds return true and set the boolean result in Result.
   4460   bool ConstantFoldsToSimpleInteger(const Expr *Cond, bool &Result,
   4461                                     bool AllowLabels = false);
   4462 
   4463   /// ConstantFoldsToSimpleInteger - If the specified expression does not fold
   4464   /// to a constant, or if it does but contains a label, return false.  If it
   4465   /// constant folds return true and set the folded value.
   4466   bool ConstantFoldsToSimpleInteger(const Expr *Cond, llvm::APSInt &Result,
   4467                                     bool AllowLabels = false);
   4468 
   4469   /// isInstrumentedCondition - Determine whether the given condition is an
   4470   /// instrumentable condition (i.e. no "&&" or "||").
   4471   static bool isInstrumentedCondition(const Expr *C);
   4472 
   4473   /// EmitBranchToCounterBlock - Emit a conditional branch to a new block that
   4474   /// increments a profile counter based on the semantics of the given logical
   4475   /// operator opcode.  This is used to instrument branch condition coverage
   4476   /// for logical operators.
   4477   void EmitBranchToCounterBlock(const Expr *Cond, BinaryOperator::Opcode LOp,
   4478                                 llvm::BasicBlock *TrueBlock,
   4479                                 llvm::BasicBlock *FalseBlock,
   4480                                 uint64_t TrueCount = 0,
   4481                                 Stmt::Likelihood LH = Stmt::LH_None,
   4482                                 const Expr *CntrIdx = nullptr);
   4483 
   4484   /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an
   4485   /// if statement) to the specified blocks.  Based on the condition, this might
   4486   /// try to simplify the codegen of the conditional based on the branch.
   4487   /// TrueCount should be the number of times we expect the condition to
   4488   /// evaluate to true based on PGO data.
   4489   void EmitBranchOnBoolExpr(const Expr *Cond, llvm::BasicBlock *TrueBlock,
   4490                             llvm::BasicBlock *FalseBlock, uint64_t TrueCount,
   4491                             Stmt::Likelihood LH = Stmt::LH_None);
   4492 
   4493   /// Given an assignment `*LHS = RHS`, emit a test that checks if \p RHS is
   4494   /// nonnull, if \p LHS is marked _Nonnull.
   4495   void EmitNullabilityCheck(LValue LHS, llvm::Value *RHS, SourceLocation Loc);
   4496 
   4497   /// An enumeration which makes it easier to specify whether or not an
   4498   /// operation is a subtraction.
   4499   enum { NotSubtraction = false, IsSubtraction = true };
   4500 
   4501   /// Same as IRBuilder::CreateInBoundsGEP, but additionally emits a check to
   4502   /// detect undefined behavior when the pointer overflow sanitizer is enabled.
   4503   /// \p SignedIndices indicates whether any of the GEP indices are signed.
   4504   /// \p IsSubtraction indicates whether the expression used to form the GEP
   4505   /// is a subtraction.
   4506   llvm::Value *EmitCheckedInBoundsGEP(llvm::Value *Ptr,
   4507                                       ArrayRef<llvm::Value *> IdxList,
   4508                                       bool SignedIndices,
   4509                                       bool IsSubtraction,
   4510                                       SourceLocation Loc,
   4511                                       const Twine &Name = "");
   4512 
   4513   /// Specifies which type of sanitizer check to apply when handling a
   4514   /// particular builtin.
   4515   enum BuiltinCheckKind {
   4516     BCK_CTZPassedZero,
   4517     BCK_CLZPassedZero,
   4518   };
   4519 
   4520   /// Emits an argument for a call to a builtin. If the builtin sanitizer is
   4521   /// enabled, a runtime check specified by \p Kind is also emitted.
   4522   llvm::Value *EmitCheckedArgForBuiltin(const Expr *E, BuiltinCheckKind Kind);
   4523 
   4524   /// Emit a description of a type in a format suitable for passing to
   4525   /// a runtime sanitizer handler.
   4526   llvm::Constant *EmitCheckTypeDescriptor(QualType T);
   4527 
   4528   /// Convert a value into a format suitable for passing to a runtime
   4529   /// sanitizer handler.
   4530   llvm::Value *EmitCheckValue(llvm::Value *V);
   4531 
   4532   /// Emit a description of a source location in a format suitable for
   4533   /// passing to a runtime sanitizer handler.
   4534   llvm::Constant *EmitCheckSourceLocation(SourceLocation Loc);
   4535 
   4536   /// Create a basic block that will either trap or call a handler function in
   4537   /// the UBSan runtime with the provided arguments, and create a conditional
   4538   /// branch to it.
   4539   void EmitCheck(ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
   4540                  SanitizerHandler Check, ArrayRef<llvm::Constant *> StaticArgs,
   4541                  ArrayRef<llvm::Value *> DynamicArgs);
   4542 
   4543   /// Emit a slow path cross-DSO CFI check which calls __cfi_slowpath
   4544   /// if Cond if false.
   4545   void EmitCfiSlowPathCheck(SanitizerMask Kind, llvm::Value *Cond,
   4546                             llvm::ConstantInt *TypeId, llvm::Value *Ptr,
   4547                             ArrayRef<llvm::Constant *> StaticArgs);
   4548 
   4549   /// Emit a reached-unreachable diagnostic if \p Loc is valid and runtime
   4550   /// checking is enabled. Otherwise, just emit an unreachable instruction.
   4551   void EmitUnreachable(SourceLocation Loc);
   4552 
   4553   /// Create a basic block that will call the trap intrinsic, and emit a
   4554   /// conditional branch to it, for the -ftrapv checks.
   4555   void EmitTrapCheck(llvm::Value *Checked, SanitizerHandler CheckHandlerID);
   4556 
   4557   /// Emit a call to trap or debugtrap and attach function attribute
   4558   /// "trap-func-name" if specified.
   4559   llvm::CallInst *EmitTrapCall(llvm::Intrinsic::ID IntrID);
   4560 
   4561   /// Emit a stub for the cross-DSO CFI check function.
   4562   void EmitCfiCheckStub();
   4563 
   4564   /// Emit a cross-DSO CFI failure handling function.
   4565   void EmitCfiCheckFail();
   4566 
   4567   /// Create a check for a function parameter that may potentially be
   4568   /// declared as non-null.
   4569   void EmitNonNullArgCheck(RValue RV, QualType ArgType, SourceLocation ArgLoc,
   4570                            AbstractCallee AC, unsigned ParmNum);
   4571 
   4572   /// EmitCallArg - Emit a single call argument.
   4573   void EmitCallArg(CallArgList &args, const Expr *E, QualType ArgType);
   4574 
   4575   /// EmitDelegateCallArg - We are performing a delegate call; that
   4576   /// is, the current function is delegating to another one.  Produce
   4577   /// a r-value suitable for passing the given parameter.
   4578   void EmitDelegateCallArg(CallArgList &args, const VarDecl *param,
   4579                            SourceLocation loc);
   4580 
   4581   /// SetFPAccuracy - Set the minimum required accuracy of the given floating
   4582   /// point operation, expressed as the maximum relative error in ulp.
   4583   void SetFPAccuracy(llvm::Value *Val, float Accuracy);
   4584 
   4585   /// SetFPModel - Control floating point behavior via fp-model settings.
   4586   void SetFPModel();
   4587 
   4588   /// Set the codegen fast-math flags.
   4589   void SetFastMathFlags(FPOptions FPFeatures);
   4590 
   4591 private:
   4592   llvm::MDNode *getRangeForLoadFromType(QualType Ty);
   4593   void EmitReturnOfRValue(RValue RV, QualType Ty);
   4594 
   4595   void deferPlaceholderReplacement(llvm::Instruction *Old, llvm::Value *New);
   4596 
   4597   llvm::SmallVector<std::pair<llvm::WeakTrackingVH, llvm::Value *>, 4>
   4598       DeferredReplacements;
   4599 
   4600   /// Set the address of a local variable.
   4601   void setAddrOfLocalVar(const VarDecl *VD, Address Addr) {
   4602     assert(!LocalDeclMap.count(VD) && "Decl already exists in LocalDeclMap!");
   4603     LocalDeclMap.insert({VD, Addr});
   4604   }
   4605 
   4606   /// ExpandTypeFromArgs - Reconstruct a structure of type \arg Ty
   4607   /// from function arguments into \arg Dst. See ABIArgInfo::Expand.
   4608   ///
   4609   /// \param AI - The first function argument of the expansion.
   4610   void ExpandTypeFromArgs(QualType Ty, LValue Dst,
   4611                           llvm::Function::arg_iterator &AI);
   4612 
   4613   /// ExpandTypeToArgs - Expand an CallArg \arg Arg, with the LLVM type for \arg
   4614   /// Ty, into individual arguments on the provided vector \arg IRCallArgs,
   4615   /// starting at index \arg IRCallArgPos. See ABIArgInfo::Expand.
   4616   void ExpandTypeToArgs(QualType Ty, CallArg Arg, llvm::FunctionType *IRFuncTy,
   4617                         SmallVectorImpl<llvm::Value *> &IRCallArgs,
   4618                         unsigned &IRCallArgPos);
   4619 
   4620   llvm::Value* EmitAsmInput(const TargetInfo::ConstraintInfo &Info,
   4621                             const Expr *InputExpr, std::string &ConstraintStr);
   4622 
   4623   llvm::Value* EmitAsmInputLValue(const TargetInfo::ConstraintInfo &Info,
   4624                                   LValue InputValue, QualType InputType,
   4625                                   std::string &ConstraintStr,
   4626                                   SourceLocation Loc);
   4627 
   4628   /// Attempts to statically evaluate the object size of E. If that
   4629   /// fails, emits code to figure the size of E out for us. This is
   4630   /// pass_object_size aware.
   4631   ///
   4632   /// If EmittedExpr is non-null, this will use that instead of re-emitting E.
   4633   llvm::Value *evaluateOrEmitBuiltinObjectSize(const Expr *E, unsigned Type,
   4634                                                llvm::IntegerType *ResType,
   4635                                                llvm::Value *EmittedE,
   4636                                                bool IsDynamic);
   4637 
   4638   /// Emits the size of E, as required by __builtin_object_size. This
   4639   /// function is aware of pass_object_size parameters, and will act accordingly
   4640   /// if E is a parameter with the pass_object_size attribute.
   4641   llvm::Value *emitBuiltinObjectSize(const Expr *E, unsigned Type,
   4642                                      llvm::IntegerType *ResType,
   4643                                      llvm::Value *EmittedE,
   4644                                      bool IsDynamic);
   4645 
   4646   void emitZeroOrPatternForAutoVarInit(QualType type, const VarDecl &D,
   4647                                        Address Loc);
   4648 
   4649 public:
   4650   enum class EvaluationOrder {
   4651     ///! No language constraints on evaluation order.
   4652     Default,
   4653     ///! Language semantics require left-to-right evaluation.
   4654     ForceLeftToRight,
   4655     ///! Language semantics require right-to-left evaluation.
   4656     ForceRightToLeft
   4657   };
   4658 
   4659   // Wrapper for function prototype sources. Wraps either a FunctionProtoType or
   4660   // an ObjCMethodDecl.
   4661   struct PrototypeWrapper {
   4662     llvm::PointerUnion<const FunctionProtoType *, const ObjCMethodDecl *> P;
   4663 
   4664     PrototypeWrapper(const FunctionProtoType *FT) : P(FT) {}
   4665     PrototypeWrapper(const ObjCMethodDecl *MD) : P(MD) {}
   4666   };
   4667 
   4668   void EmitCallArgs(CallArgList &Args, PrototypeWrapper Prototype,
   4669                     llvm::iterator_range<CallExpr::const_arg_iterator> ArgRange,
   4670                     AbstractCallee AC = AbstractCallee(),
   4671                     unsigned ParamsToSkip = 0,
   4672                     EvaluationOrder Order = EvaluationOrder::Default);
   4673 
   4674   /// EmitPointerWithAlignment - Given an expression with a pointer type,
   4675   /// emit the value and compute our best estimate of the alignment of the
   4676   /// pointee.
   4677   ///
   4678   /// \param BaseInfo - If non-null, this will be initialized with
   4679   /// information about the source of the alignment and the may-alias
   4680   /// attribute.  Note that this function will conservatively fall back on
   4681   /// the type when it doesn't recognize the expression and may-alias will
   4682   /// be set to false.
   4683   ///
   4684   /// One reasonable way to use this information is when there's a language
   4685   /// guarantee that the pointer must be aligned to some stricter value, and
   4686   /// we're simply trying to ensure that sufficiently obvious uses of under-
   4687   /// aligned objects don't get miscompiled; for example, a placement new
   4688   /// into the address of a local variable.  In such a case, it's quite
   4689   /// reasonable to just ignore the returned alignment when it isn't from an
   4690   /// explicit source.
   4691   Address EmitPointerWithAlignment(const Expr *Addr,
   4692                                    LValueBaseInfo *BaseInfo = nullptr,
   4693                                    TBAAAccessInfo *TBAAInfo = nullptr);
   4694 
   4695   /// If \p E references a parameter with pass_object_size info or a constant
   4696   /// array size modifier, emit the object size divided by the size of \p EltTy.
   4697   /// Otherwise return null.
   4698   llvm::Value *LoadPassedObjectSize(const Expr *E, QualType EltTy);
   4699 
   4700   void EmitSanitizerStatReport(llvm::SanitizerStatKind SSK);
   4701 
   4702   struct MultiVersionResolverOption {
   4703     llvm::Function *Function;
   4704     struct Conds {
   4705       StringRef Architecture;
   4706       llvm::SmallVector<StringRef, 8> Features;
   4707 
   4708       Conds(StringRef Arch, ArrayRef<StringRef> Feats)
   4709           : Architecture(Arch), Features(Feats.begin(), Feats.end()) {}
   4710     } Conditions;
   4711 
   4712     MultiVersionResolverOption(llvm::Function *F, StringRef Arch,
   4713                                ArrayRef<StringRef> Feats)
   4714         : Function(F), Conditions(Arch, Feats) {}
   4715   };
   4716 
   4717   // Emits the body of a multiversion function's resolver. Assumes that the
   4718   // options are already sorted in the proper order, with the 'default' option
   4719   // last (if it exists).
   4720   void EmitMultiVersionResolver(llvm::Function *Resolver,
   4721                                 ArrayRef<MultiVersionResolverOption> Options);
   4722 
   4723   static uint64_t GetX86CpuSupportsMask(ArrayRef<StringRef> FeatureStrs);
   4724 
   4725 private:
   4726   QualType getVarArgType(const Expr *Arg);
   4727 
   4728   void EmitDeclMetadata();
   4729 
   4730   BlockByrefHelpers *buildByrefHelpers(llvm::StructType &byrefType,
   4731                                   const AutoVarEmission &emission);
   4732 
   4733   void AddObjCARCExceptionMetadata(llvm::Instruction *Inst);
   4734 
   4735   llvm::Value *GetValueForARMHint(unsigned BuiltinID);
   4736   llvm::Value *EmitX86CpuIs(const CallExpr *E);
   4737   llvm::Value *EmitX86CpuIs(StringRef CPUStr);
   4738   llvm::Value *EmitX86CpuSupports(const CallExpr *E);
   4739   llvm::Value *EmitX86CpuSupports(ArrayRef<StringRef> FeatureStrs);
   4740   llvm::Value *EmitX86CpuSupports(uint64_t Mask);
   4741   llvm::Value *EmitX86CpuInit();
   4742   llvm::Value *FormResolverCondition(const MultiVersionResolverOption &RO);
   4743 };
   4744 
   4745 /// TargetFeatures - This class is used to check whether the builtin function
   4746 /// has the required tagert specific features. It is able to support the
   4747 /// combination of ','(and), '|'(or), and '()'. By default, the priority of
   4748 /// ',' is higher than that of '|' .
   4749 /// E.g:
   4750 /// A,B|C means the builtin function requires both A and B, or C.
   4751 /// If we want the builtin function requires both A and B, or both A and C,
   4752 /// there are two ways: A,B|A,C or A,(B|C).
   4753 /// The FeaturesList should not contain spaces, and brackets must appear in
   4754 /// pairs.
   4755 class TargetFeatures {
   4756   struct FeatureListStatus {
   4757     bool HasFeatures;
   4758     StringRef CurFeaturesList;
   4759   };
   4760 
   4761   const llvm::StringMap<bool> &CallerFeatureMap;
   4762 
   4763   FeatureListStatus getAndFeatures(StringRef FeatureList) {
   4764     int InParentheses = 0;
   4765     bool HasFeatures = true;
   4766     size_t SubexpressionStart = 0;
   4767     for (size_t i = 0, e = FeatureList.size(); i < e; ++i) {
   4768       char CurrentToken = FeatureList[i];
   4769       switch (CurrentToken) {
   4770       default:
   4771         break;
   4772       case '(':
   4773         if (InParentheses == 0)
   4774           SubexpressionStart = i + 1;
   4775         ++InParentheses;
   4776         break;
   4777       case ')':
   4778         --InParentheses;
   4779         assert(InParentheses >= 0 && "Parentheses are not in pair");
   4780         LLVM_FALLTHROUGH;
   4781       case '|':
   4782       case ',':
   4783         if (InParentheses == 0) {
   4784           if (HasFeatures && i != SubexpressionStart) {
   4785             StringRef F = FeatureList.slice(SubexpressionStart, i);
   4786             HasFeatures = CurrentToken == ')' ? hasRequiredFeatures(F)
   4787                                               : CallerFeatureMap.lookup(F);
   4788           }
   4789           SubexpressionStart = i + 1;
   4790           if (CurrentToken == '|') {
   4791             return {HasFeatures, FeatureList.substr(SubexpressionStart)};
   4792           }
   4793         }
   4794         break;
   4795       }
   4796     }
   4797     assert(InParentheses == 0 && "Parentheses are not in pair");
   4798     if (HasFeatures && SubexpressionStart != FeatureList.size())
   4799       HasFeatures =
   4800           CallerFeatureMap.lookup(FeatureList.substr(SubexpressionStart));
   4801     return {HasFeatures, StringRef()};
   4802   }
   4803 
   4804 public:
   4805   bool hasRequiredFeatures(StringRef FeatureList) {
   4806     FeatureListStatus FS = {false, FeatureList};
   4807     while (!FS.HasFeatures && !FS.CurFeaturesList.empty())
   4808       FS = getAndFeatures(FS.CurFeaturesList);
   4809     return FS.HasFeatures;
   4810   }
   4811 
   4812   TargetFeatures(const llvm::StringMap<bool> &CallerFeatureMap)
   4813       : CallerFeatureMap(CallerFeatureMap) {}
   4814 };
   4815 
   4816 inline DominatingLLVMValue::saved_type
   4817 DominatingLLVMValue::save(CodeGenFunction &CGF, llvm::Value *value) {
   4818   if (!needsSaving(value)) return saved_type(value, false);
   4819 
   4820   // Otherwise, we need an alloca.
   4821   auto align = CharUnits::fromQuantity(
   4822             CGF.CGM.getDataLayout().getPrefTypeAlignment(value->getType()));
   4823   Address alloca =
   4824     CGF.CreateTempAlloca(value->getType(), align, "cond-cleanup.save");
   4825   CGF.Builder.CreateStore(value, alloca);
   4826 
   4827   return saved_type(alloca.getPointer(), true);
   4828 }
   4829 
   4830 inline llvm::Value *DominatingLLVMValue::restore(CodeGenFunction &CGF,
   4831                                                  saved_type value) {
   4832   // If the value says it wasn't saved, trust that it's still dominating.
   4833   if (!value.getInt()) return value.getPointer();
   4834 
   4835   // Otherwise, it should be an alloca instruction, as set up in save().
   4836   auto alloca = cast<llvm::AllocaInst>(value.getPointer());
   4837   return CGF.Builder.CreateAlignedLoad(alloca->getAllocatedType(), alloca,
   4838                                        alloca->getAlign());
   4839 }
   4840 
   4841 }  // end namespace CodeGen
   4842 
   4843 // Map the LangOption for floating point exception behavior into
   4844 // the corresponding enum in the IR.
   4845 llvm::fp::ExceptionBehavior
   4846 ToConstrainedExceptMD(LangOptions::FPExceptionModeKind Kind);
   4847 }  // end namespace clang
   4848 
   4849 #endif
   4850