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      1 //===--- CodeGenModule.h - Per-Module state for LLVM CodeGen ----*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This is the internal per-translation-unit state used for llvm translation.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENMODULE_H
     15 #define LLVM_CLANG_LIB_CODEGEN_CODEGENMODULE_H
     16 
     17 #include "CGVTables.h"
     18 #include "CodeGenTypeCache.h"
     19 #include "CodeGenTypes.h"
     20 #include "SanitizerMetadata.h"
     21 #include "clang/AST/Attr.h"
     22 #include "clang/AST/DeclCXX.h"
     23 #include "clang/AST/DeclObjC.h"
     24 #include "clang/AST/GlobalDecl.h"
     25 #include "clang/AST/Mangle.h"
     26 #include "clang/Basic/ABI.h"
     27 #include "clang/Basic/LangOptions.h"
     28 #include "clang/Basic/Module.h"
     29 #include "clang/Basic/SanitizerBlacklist.h"
     30 #include "llvm/ADT/DenseMap.h"
     31 #include "llvm/ADT/SetVector.h"
     32 #include "llvm/ADT/SmallPtrSet.h"
     33 #include "llvm/ADT/StringMap.h"
     34 #include "llvm/IR/Module.h"
     35 #include "llvm/IR/ValueHandle.h"
     36 
     37 namespace llvm {
     38 class Module;
     39 class Constant;
     40 class ConstantInt;
     41 class Function;
     42 class GlobalValue;
     43 class DataLayout;
     44 class FunctionType;
     45 class LLVMContext;
     46 class IndexedInstrProfReader;
     47 }
     48 
     49 namespace clang {
     50 class TargetCodeGenInfo;
     51 class ASTContext;
     52 class AtomicType;
     53 class FunctionDecl;
     54 class IdentifierInfo;
     55 class ObjCMethodDecl;
     56 class ObjCImplementationDecl;
     57 class ObjCCategoryImplDecl;
     58 class ObjCProtocolDecl;
     59 class ObjCEncodeExpr;
     60 class BlockExpr;
     61 class CharUnits;
     62 class Decl;
     63 class Expr;
     64 class Stmt;
     65 class InitListExpr;
     66 class StringLiteral;
     67 class NamedDecl;
     68 class ValueDecl;
     69 class VarDecl;
     70 class LangOptions;
     71 class CodeGenOptions;
     72 class HeaderSearchOptions;
     73 class PreprocessorOptions;
     74 class DiagnosticsEngine;
     75 class AnnotateAttr;
     76 class CXXDestructorDecl;
     77 class Module;
     78 class CoverageSourceInfo;
     79 
     80 namespace CodeGen {
     81 
     82 class CallArgList;
     83 class CodeGenFunction;
     84 class CodeGenTBAA;
     85 class CGCXXABI;
     86 class CGDebugInfo;
     87 class CGObjCRuntime;
     88 class CGOpenCLRuntime;
     89 class CGOpenMPRuntime;
     90 class CGCUDARuntime;
     91 class BlockFieldFlags;
     92 class FunctionArgList;
     93 class CoverageMappingModuleGen;
     94 
     95 struct OrderGlobalInits {
     96   unsigned int priority;
     97   unsigned int lex_order;
     98   OrderGlobalInits(unsigned int p, unsigned int l)
     99       : priority(p), lex_order(l) {}
    100 
    101   bool operator==(const OrderGlobalInits &RHS) const {
    102     return priority == RHS.priority && lex_order == RHS.lex_order;
    103   }
    104 
    105   bool operator<(const OrderGlobalInits &RHS) const {
    106     return std::tie(priority, lex_order) <
    107            std::tie(RHS.priority, RHS.lex_order);
    108   }
    109 };
    110 
    111 struct ObjCEntrypoints {
    112   ObjCEntrypoints() { memset(this, 0, sizeof(*this)); }
    113 
    114     /// void objc_autoreleasePoolPop(void*);
    115   llvm::Constant *objc_autoreleasePoolPop;
    116 
    117   /// void *objc_autoreleasePoolPush(void);
    118   llvm::Constant *objc_autoreleasePoolPush;
    119 
    120   /// id objc_autorelease(id);
    121   llvm::Constant *objc_autorelease;
    122 
    123   /// id objc_autoreleaseReturnValue(id);
    124   llvm::Constant *objc_autoreleaseReturnValue;
    125 
    126   /// void objc_copyWeak(id *dest, id *src);
    127   llvm::Constant *objc_copyWeak;
    128 
    129   /// void objc_destroyWeak(id*);
    130   llvm::Constant *objc_destroyWeak;
    131 
    132   /// id objc_initWeak(id*, id);
    133   llvm::Constant *objc_initWeak;
    134 
    135   /// id objc_loadWeak(id*);
    136   llvm::Constant *objc_loadWeak;
    137 
    138   /// id objc_loadWeakRetained(id*);
    139   llvm::Constant *objc_loadWeakRetained;
    140 
    141   /// void objc_moveWeak(id *dest, id *src);
    142   llvm::Constant *objc_moveWeak;
    143 
    144   /// id objc_retain(id);
    145   llvm::Constant *objc_retain;
    146 
    147   /// id objc_retainAutorelease(id);
    148   llvm::Constant *objc_retainAutorelease;
    149 
    150   /// id objc_retainAutoreleaseReturnValue(id);
    151   llvm::Constant *objc_retainAutoreleaseReturnValue;
    152 
    153   /// id objc_retainAutoreleasedReturnValue(id);
    154   llvm::Constant *objc_retainAutoreleasedReturnValue;
    155 
    156   /// id objc_retainBlock(id);
    157   llvm::Constant *objc_retainBlock;
    158 
    159   /// void objc_release(id);
    160   llvm::Constant *objc_release;
    161 
    162   /// id objc_storeStrong(id*, id);
    163   llvm::Constant *objc_storeStrong;
    164 
    165   /// id objc_storeWeak(id*, id);
    166   llvm::Constant *objc_storeWeak;
    167 
    168   /// A void(void) inline asm to use to mark that the return value of
    169   /// a call will be immediately retain.
    170   llvm::InlineAsm *retainAutoreleasedReturnValueMarker;
    171 
    172   /// void clang.arc.use(...);
    173   llvm::Constant *clang_arc_use;
    174 };
    175 
    176 /// This class records statistics on instrumentation based profiling.
    177 class InstrProfStats {
    178   uint32_t VisitedInMainFile;
    179   uint32_t MissingInMainFile;
    180   uint32_t Visited;
    181   uint32_t Missing;
    182   uint32_t Mismatched;
    183 
    184 public:
    185   InstrProfStats()
    186       : VisitedInMainFile(0), MissingInMainFile(0), Visited(0), Missing(0),
    187         Mismatched(0) {}
    188   /// Record that we've visited a function and whether or not that function was
    189   /// in the main source file.
    190   void addVisited(bool MainFile) {
    191     if (MainFile)
    192       ++VisitedInMainFile;
    193     ++Visited;
    194   }
    195   /// Record that a function we've visited has no profile data.
    196   void addMissing(bool MainFile) {
    197     if (MainFile)
    198       ++MissingInMainFile;
    199     ++Missing;
    200   }
    201   /// Record that a function we've visited has mismatched profile data.
    202   void addMismatched(bool MainFile) { ++Mismatched; }
    203   /// Whether or not the stats we've gathered indicate any potential problems.
    204   bool hasDiagnostics() { return Missing || Mismatched; }
    205   /// Report potential problems we've found to \c Diags.
    206   void reportDiagnostics(DiagnosticsEngine &Diags, StringRef MainFile);
    207 };
    208 
    209 /// A pair of helper functions for a __block variable.
    210 class BlockByrefHelpers : public llvm::FoldingSetNode {
    211   // MSVC requires this type to be complete in order to process this
    212   // header.
    213 public:
    214   llvm::Constant *CopyHelper;
    215   llvm::Constant *DisposeHelper;
    216 
    217   /// The alignment of the field.  This is important because
    218   /// different offsets to the field within the byref struct need to
    219   /// have different helper functions.
    220   CharUnits Alignment;
    221 
    222   BlockByrefHelpers(CharUnits alignment) : Alignment(alignment) {}
    223   BlockByrefHelpers(const BlockByrefHelpers &) = default;
    224   virtual ~BlockByrefHelpers();
    225 
    226   void Profile(llvm::FoldingSetNodeID &id) const {
    227     id.AddInteger(Alignment.getQuantity());
    228     profileImpl(id);
    229   }
    230   virtual void profileImpl(llvm::FoldingSetNodeID &id) const = 0;
    231 
    232   virtual bool needsCopy() const { return true; }
    233   virtual void emitCopy(CodeGenFunction &CGF, Address dest, Address src) = 0;
    234 
    235   virtual bool needsDispose() const { return true; }
    236   virtual void emitDispose(CodeGenFunction &CGF, Address field) = 0;
    237 };
    238 
    239 /// This class organizes the cross-function state that is used while generating
    240 /// LLVM code.
    241 class CodeGenModule : public CodeGenTypeCache {
    242   CodeGenModule(const CodeGenModule &) = delete;
    243   void operator=(const CodeGenModule &) = delete;
    244 
    245 public:
    246   struct Structor {
    247     Structor() : Priority(0), Initializer(nullptr), AssociatedData(nullptr) {}
    248     Structor(int Priority, llvm::Constant *Initializer,
    249              llvm::Constant *AssociatedData)
    250         : Priority(Priority), Initializer(Initializer),
    251           AssociatedData(AssociatedData) {}
    252     int Priority;
    253     llvm::Constant *Initializer;
    254     llvm::Constant *AssociatedData;
    255   };
    256 
    257   typedef std::vector<Structor> CtorList;
    258 
    259 private:
    260   ASTContext &Context;
    261   const LangOptions &LangOpts;
    262   const HeaderSearchOptions &HeaderSearchOpts; // Only used for debug info.
    263   const PreprocessorOptions &PreprocessorOpts; // Only used for debug info.
    264   const CodeGenOptions &CodeGenOpts;
    265   llvm::Module &TheModule;
    266   DiagnosticsEngine &Diags;
    267   const TargetInfo &Target;
    268   std::unique_ptr<CGCXXABI> ABI;
    269   llvm::LLVMContext &VMContext;
    270 
    271   CodeGenTBAA *TBAA;
    272 
    273   mutable const TargetCodeGenInfo *TheTargetCodeGenInfo;
    274 
    275   // This should not be moved earlier, since its initialization depends on some
    276   // of the previous reference members being already initialized and also checks
    277   // if TheTargetCodeGenInfo is NULL
    278   CodeGenTypes Types;
    279 
    280   /// Holds information about C++ vtables.
    281   CodeGenVTables VTables;
    282 
    283   CGObjCRuntime* ObjCRuntime;
    284   CGOpenCLRuntime* OpenCLRuntime;
    285   CGOpenMPRuntime* OpenMPRuntime;
    286   CGCUDARuntime* CUDARuntime;
    287   CGDebugInfo* DebugInfo;
    288   ObjCEntrypoints *ObjCData;
    289   llvm::MDNode *NoObjCARCExceptionsMetadata;
    290   std::unique_ptr<llvm::IndexedInstrProfReader> PGOReader;
    291   InstrProfStats PGOStats;
    292 
    293   // A set of references that have only been seen via a weakref so far. This is
    294   // used to remove the weak of the reference if we ever see a direct reference
    295   // or a definition.
    296   llvm::SmallPtrSet<llvm::GlobalValue*, 10> WeakRefReferences;
    297 
    298   /// This contains all the decls which have definitions but/ which are deferred
    299   /// for emission and therefore should only be output if they are actually
    300   /// used. If a decl is in this, then it is known to have not been referenced
    301   /// yet.
    302   std::map<StringRef, GlobalDecl> DeferredDecls;
    303 
    304   /// This is a list of deferred decls which we have seen that *are* actually
    305   /// referenced. These get code generated when the module is done.
    306   struct DeferredGlobal {
    307     DeferredGlobal(llvm::GlobalValue *GV, GlobalDecl GD) : GV(GV), GD(GD) {}
    308     llvm::TrackingVH<llvm::GlobalValue> GV;
    309     GlobalDecl GD;
    310   };
    311   std::vector<DeferredGlobal> DeferredDeclsToEmit;
    312   void addDeferredDeclToEmit(llvm::GlobalValue *GV, GlobalDecl GD) {
    313     DeferredDeclsToEmit.emplace_back(GV, GD);
    314   }
    315 
    316   /// List of alias we have emitted. Used to make sure that what they point to
    317   /// is defined once we get to the end of the of the translation unit.
    318   std::vector<GlobalDecl> Aliases;
    319 
    320   typedef llvm::StringMap<llvm::TrackingVH<llvm::Constant> > ReplacementsTy;
    321   ReplacementsTy Replacements;
    322 
    323   /// List of global values to be replaced with something else. Used when we
    324   /// want to replace a GlobalValue but can't identify it by its mangled name
    325   /// anymore (because the name is already taken).
    326   llvm::SmallVector<std::pair<llvm::GlobalValue *, llvm::Constant *>, 8>
    327     GlobalValReplacements;
    328 
    329   /// Set of global decls for which we already diagnosed mangled name conflict.
    330   /// Required to not issue a warning (on a mangling conflict) multiple times
    331   /// for the same decl.
    332   llvm::DenseSet<GlobalDecl> DiagnosedConflictingDefinitions;
    333 
    334   /// A queue of (optional) vtables to consider emitting.
    335   std::vector<const CXXRecordDecl*> DeferredVTables;
    336 
    337   /// List of global values which are required to be present in the object file;
    338   /// bitcast to i8*. This is used for forcing visibility of symbols which may
    339   /// otherwise be optimized out.
    340   std::vector<llvm::WeakVH> LLVMUsed;
    341   std::vector<llvm::WeakVH> LLVMCompilerUsed;
    342 
    343   /// Store the list of global constructors and their respective priorities to
    344   /// be emitted when the translation unit is complete.
    345   CtorList GlobalCtors;
    346 
    347   /// Store the list of global destructors and their respective priorities to be
    348   /// emitted when the translation unit is complete.
    349   CtorList GlobalDtors;
    350 
    351   /// An ordered map of canonical GlobalDecls to their mangled names.
    352   llvm::MapVector<GlobalDecl, StringRef> MangledDeclNames;
    353   llvm::StringMap<GlobalDecl, llvm::BumpPtrAllocator> Manglings;
    354 
    355   /// Global annotations.
    356   std::vector<llvm::Constant*> Annotations;
    357 
    358   /// Map used to get unique annotation strings.
    359   llvm::StringMap<llvm::Constant*> AnnotationStrings;
    360 
    361   llvm::StringMap<llvm::GlobalVariable *> CFConstantStringMap;
    362 
    363   llvm::DenseMap<llvm::Constant *, llvm::GlobalVariable *> ConstantStringMap;
    364   llvm::DenseMap<const Decl*, llvm::Constant *> StaticLocalDeclMap;
    365   llvm::DenseMap<const Decl*, llvm::GlobalVariable*> StaticLocalDeclGuardMap;
    366   llvm::DenseMap<const Expr*, llvm::Constant *> MaterializedGlobalTemporaryMap;
    367 
    368   llvm::DenseMap<QualType, llvm::Constant *> AtomicSetterHelperFnMap;
    369   llvm::DenseMap<QualType, llvm::Constant *> AtomicGetterHelperFnMap;
    370 
    371   /// Map used to get unique type descriptor constants for sanitizers.
    372   llvm::DenseMap<QualType, llvm::Constant *> TypeDescriptorMap;
    373 
    374   /// Map used to track internal linkage functions declared within
    375   /// extern "C" regions.
    376   typedef llvm::MapVector<IdentifierInfo *,
    377                           llvm::GlobalValue *> StaticExternCMap;
    378   StaticExternCMap StaticExternCValues;
    379 
    380   /// \brief thread_local variables defined or used in this TU.
    381   std::vector<const VarDecl *> CXXThreadLocals;
    382 
    383   /// \brief thread_local variables with initializers that need to run
    384   /// before any thread_local variable in this TU is odr-used.
    385   std::vector<llvm::Function *> CXXThreadLocalInits;
    386   std::vector<const VarDecl *> CXXThreadLocalInitVars;
    387 
    388   /// Global variables with initializers that need to run before main.
    389   std::vector<llvm::Function *> CXXGlobalInits;
    390 
    391   /// When a C++ decl with an initializer is deferred, null is
    392   /// appended to CXXGlobalInits, and the index of that null is placed
    393   /// here so that the initializer will be performed in the correct
    394   /// order. Once the decl is emitted, the index is replaced with ~0U to ensure
    395   /// that we don't re-emit the initializer.
    396   llvm::DenseMap<const Decl*, unsigned> DelayedCXXInitPosition;
    397 
    398   typedef std::pair<OrderGlobalInits, llvm::Function*> GlobalInitData;
    399 
    400   struct GlobalInitPriorityCmp {
    401     bool operator()(const GlobalInitData &LHS,
    402                     const GlobalInitData &RHS) const {
    403       return LHS.first.priority < RHS.first.priority;
    404     }
    405   };
    406 
    407   /// Global variables with initializers whose order of initialization is set by
    408   /// init_priority attribute.
    409   SmallVector<GlobalInitData, 8> PrioritizedCXXGlobalInits;
    410 
    411   /// Global destructor functions and arguments that need to run on termination.
    412   std::vector<std::pair<llvm::WeakVH,llvm::Constant*> > CXXGlobalDtors;
    413 
    414   /// \brief The complete set of modules that has been imported.
    415   llvm::SetVector<clang::Module *> ImportedModules;
    416 
    417   /// \brief A vector of metadata strings.
    418   SmallVector<llvm::Metadata *, 16> LinkerOptionsMetadata;
    419 
    420   /// @name Cache for Objective-C runtime types
    421   /// @{
    422 
    423   /// Cached reference to the class for constant strings. This value has type
    424   /// int * but is actually an Obj-C class pointer.
    425   llvm::WeakVH CFConstantStringClassRef;
    426 
    427   /// Cached reference to the class for constant strings. This value has type
    428   /// int * but is actually an Obj-C class pointer.
    429   llvm::WeakVH ConstantStringClassRef;
    430 
    431   /// \brief The LLVM type corresponding to NSConstantString.
    432   llvm::StructType *NSConstantStringType;
    433 
    434   /// \brief The type used to describe the state of a fast enumeration in
    435   /// Objective-C's for..in loop.
    436   QualType ObjCFastEnumerationStateType;
    437 
    438   /// @}
    439 
    440   /// Lazily create the Objective-C runtime
    441   void createObjCRuntime();
    442 
    443   void createOpenCLRuntime();
    444   void createOpenMPRuntime();
    445   void createCUDARuntime();
    446 
    447   bool isTriviallyRecursive(const FunctionDecl *F);
    448   bool shouldEmitFunction(GlobalDecl GD);
    449 
    450   /// @name Cache for Blocks Runtime Globals
    451   /// @{
    452 
    453   llvm::Constant *NSConcreteGlobalBlock;
    454   llvm::Constant *NSConcreteStackBlock;
    455 
    456   llvm::Constant *BlockObjectAssign;
    457   llvm::Constant *BlockObjectDispose;
    458 
    459   llvm::Type *BlockDescriptorType;
    460   llvm::Type *GenericBlockLiteralType;
    461 
    462   struct {
    463     int GlobalUniqueCount;
    464   } Block;
    465 
    466   /// void @llvm.lifetime.start(i64 %size, i8* nocapture <ptr>)
    467   llvm::Constant *LifetimeStartFn;
    468 
    469   /// void @llvm.lifetime.end(i64 %size, i8* nocapture <ptr>)
    470   llvm::Constant *LifetimeEndFn;
    471 
    472   GlobalDecl initializedGlobalDecl;
    473 
    474   std::unique_ptr<SanitizerMetadata> SanitizerMD;
    475 
    476   /// @}
    477 
    478   llvm::DenseMap<const Decl *, bool> DeferredEmptyCoverageMappingDecls;
    479 
    480   std::unique_ptr<CoverageMappingModuleGen> CoverageMapping;
    481 
    482   /// Mapping from canonical types to their metadata identifiers. We need to
    483   /// maintain this mapping because identifiers may be formed from distinct
    484   /// MDNodes.
    485   llvm::DenseMap<QualType, llvm::Metadata *> MetadataIdMap;
    486 
    487 public:
    488   CodeGenModule(ASTContext &C, const HeaderSearchOptions &headersearchopts,
    489                 const PreprocessorOptions &ppopts,
    490                 const CodeGenOptions &CodeGenOpts, llvm::Module &M,
    491                 DiagnosticsEngine &Diags,
    492                 CoverageSourceInfo *CoverageInfo = nullptr);
    493 
    494   ~CodeGenModule();
    495 
    496   void clear();
    497 
    498   /// Finalize LLVM code generation.
    499   void Release();
    500 
    501   /// Return a reference to the configured Objective-C runtime.
    502   CGObjCRuntime &getObjCRuntime() {
    503     if (!ObjCRuntime) createObjCRuntime();
    504     return *ObjCRuntime;
    505   }
    506 
    507   /// Return true iff an Objective-C runtime has been configured.
    508   bool hasObjCRuntime() { return !!ObjCRuntime; }
    509 
    510   /// Return a reference to the configured OpenCL runtime.
    511   CGOpenCLRuntime &getOpenCLRuntime() {
    512     assert(OpenCLRuntime != nullptr);
    513     return *OpenCLRuntime;
    514   }
    515 
    516   /// Return a reference to the configured OpenMP runtime.
    517   CGOpenMPRuntime &getOpenMPRuntime() {
    518     assert(OpenMPRuntime != nullptr);
    519     return *OpenMPRuntime;
    520   }
    521 
    522   /// Return a reference to the configured CUDA runtime.
    523   CGCUDARuntime &getCUDARuntime() {
    524     assert(CUDARuntime != nullptr);
    525     return *CUDARuntime;
    526   }
    527 
    528   ObjCEntrypoints &getObjCEntrypoints() const {
    529     assert(ObjCData != nullptr);
    530     return *ObjCData;
    531   }
    532 
    533   InstrProfStats &getPGOStats() { return PGOStats; }
    534   llvm::IndexedInstrProfReader *getPGOReader() const { return PGOReader.get(); }
    535 
    536   CoverageMappingModuleGen *getCoverageMapping() const {
    537     return CoverageMapping.get();
    538   }
    539 
    540   llvm::Constant *getStaticLocalDeclAddress(const VarDecl *D) {
    541     return StaticLocalDeclMap[D];
    542   }
    543   void setStaticLocalDeclAddress(const VarDecl *D,
    544                                  llvm::Constant *C) {
    545     StaticLocalDeclMap[D] = C;
    546   }
    547 
    548   llvm::Constant *
    549   getOrCreateStaticVarDecl(const VarDecl &D,
    550                            llvm::GlobalValue::LinkageTypes Linkage);
    551 
    552   llvm::GlobalVariable *getStaticLocalDeclGuardAddress(const VarDecl *D) {
    553     return StaticLocalDeclGuardMap[D];
    554   }
    555   void setStaticLocalDeclGuardAddress(const VarDecl *D,
    556                                       llvm::GlobalVariable *C) {
    557     StaticLocalDeclGuardMap[D] = C;
    558   }
    559 
    560   bool lookupRepresentativeDecl(StringRef MangledName,
    561                                 GlobalDecl &Result) const;
    562 
    563   llvm::Constant *getAtomicSetterHelperFnMap(QualType Ty) {
    564     return AtomicSetterHelperFnMap[Ty];
    565   }
    566   void setAtomicSetterHelperFnMap(QualType Ty,
    567                             llvm::Constant *Fn) {
    568     AtomicSetterHelperFnMap[Ty] = Fn;
    569   }
    570 
    571   llvm::Constant *getAtomicGetterHelperFnMap(QualType Ty) {
    572     return AtomicGetterHelperFnMap[Ty];
    573   }
    574   void setAtomicGetterHelperFnMap(QualType Ty,
    575                             llvm::Constant *Fn) {
    576     AtomicGetterHelperFnMap[Ty] = Fn;
    577   }
    578 
    579   llvm::Constant *getTypeDescriptorFromMap(QualType Ty) {
    580     return TypeDescriptorMap[Ty];
    581   }
    582   void setTypeDescriptorInMap(QualType Ty, llvm::Constant *C) {
    583     TypeDescriptorMap[Ty] = C;
    584   }
    585 
    586   CGDebugInfo *getModuleDebugInfo() { return DebugInfo; }
    587 
    588   llvm::MDNode *getNoObjCARCExceptionsMetadata() {
    589     if (!NoObjCARCExceptionsMetadata)
    590       NoObjCARCExceptionsMetadata = llvm::MDNode::get(getLLVMContext(), None);
    591     return NoObjCARCExceptionsMetadata;
    592   }
    593 
    594   ASTContext &getContext() const { return Context; }
    595   const LangOptions &getLangOpts() const { return LangOpts; }
    596   const HeaderSearchOptions &getHeaderSearchOpts()
    597     const { return HeaderSearchOpts; }
    598   const PreprocessorOptions &getPreprocessorOpts()
    599     const { return PreprocessorOpts; }
    600   const CodeGenOptions &getCodeGenOpts() const { return CodeGenOpts; }
    601   llvm::Module &getModule() const { return TheModule; }
    602   DiagnosticsEngine &getDiags() const { return Diags; }
    603   const llvm::DataLayout &getDataLayout() const {
    604     return TheModule.getDataLayout();
    605   }
    606   const TargetInfo &getTarget() const { return Target; }
    607   const llvm::Triple &getTriple() const;
    608   bool supportsCOMDAT() const;
    609   void maybeSetTrivialComdat(const Decl &D, llvm::GlobalObject &GO);
    610 
    611   CGCXXABI &getCXXABI() const { return *ABI; }
    612   llvm::LLVMContext &getLLVMContext() { return VMContext; }
    613 
    614   bool shouldUseTBAA() const { return TBAA != nullptr; }
    615 
    616   const TargetCodeGenInfo &getTargetCodeGenInfo();
    617 
    618   CodeGenTypes &getTypes() { return Types; }
    619 
    620   CodeGenVTables &getVTables() { return VTables; }
    621 
    622   ItaniumVTableContext &getItaniumVTableContext() {
    623     return VTables.getItaniumVTableContext();
    624   }
    625 
    626   MicrosoftVTableContext &getMicrosoftVTableContext() {
    627     return VTables.getMicrosoftVTableContext();
    628   }
    629 
    630   CtorList &getGlobalCtors() { return GlobalCtors; }
    631   CtorList &getGlobalDtors() { return GlobalDtors; }
    632 
    633   llvm::MDNode *getTBAAInfo(QualType QTy);
    634   llvm::MDNode *getTBAAInfoForVTablePtr();
    635   llvm::MDNode *getTBAAStructInfo(QualType QTy);
    636   /// Return the path-aware tag for given base type, access node and offset.
    637   llvm::MDNode *getTBAAStructTagInfo(QualType BaseTy, llvm::MDNode *AccessN,
    638                                      uint64_t O);
    639 
    640   bool isTypeConstant(QualType QTy, bool ExcludeCtorDtor);
    641 
    642   bool isPaddedAtomicType(QualType type);
    643   bool isPaddedAtomicType(const AtomicType *type);
    644 
    645   /// Decorate the instruction with a TBAA tag. For scalar TBAA, the tag
    646   /// is the same as the type. For struct-path aware TBAA, the tag
    647   /// is different from the type: base type, access type and offset.
    648   /// When ConvertTypeToTag is true, we create a tag based on the scalar type.
    649   void DecorateInstructionWithTBAA(llvm::Instruction *Inst,
    650                                    llvm::MDNode *TBAAInfo,
    651                                    bool ConvertTypeToTag = true);
    652 
    653   /// Adds !invariant.barrier !tag to instruction
    654   void DecorateInstructionWithInvariantGroup(llvm::Instruction *I,
    655                                              const CXXRecordDecl *RD);
    656 
    657   /// Emit the given number of characters as a value of type size_t.
    658   llvm::ConstantInt *getSize(CharUnits numChars);
    659 
    660   /// Set the visibility for the given LLVM GlobalValue.
    661   void setGlobalVisibility(llvm::GlobalValue *GV, const NamedDecl *D) const;
    662 
    663   /// Set the TLS mode for the given LLVM GlobalValue for the thread-local
    664   /// variable declaration D.
    665   void setTLSMode(llvm::GlobalValue *GV, const VarDecl &D) const;
    666 
    667   static llvm::GlobalValue::VisibilityTypes GetLLVMVisibility(Visibility V) {
    668     switch (V) {
    669     case DefaultVisibility:   return llvm::GlobalValue::DefaultVisibility;
    670     case HiddenVisibility:    return llvm::GlobalValue::HiddenVisibility;
    671     case ProtectedVisibility: return llvm::GlobalValue::ProtectedVisibility;
    672     }
    673     llvm_unreachable("unknown visibility!");
    674   }
    675 
    676   llvm::Constant *GetAddrOfGlobal(GlobalDecl GD, bool IsForDefinition = false);
    677 
    678   /// Will return a global variable of the given type. If a variable with a
    679   /// different type already exists then a new  variable with the right type
    680   /// will be created and all uses of the old variable will be replaced with a
    681   /// bitcast to the new variable.
    682   llvm::GlobalVariable *
    683   CreateOrReplaceCXXRuntimeVariable(StringRef Name, llvm::Type *Ty,
    684                                     llvm::GlobalValue::LinkageTypes Linkage);
    685 
    686   llvm::Function *
    687   CreateGlobalInitOrDestructFunction(llvm::FunctionType *ty, const Twine &name,
    688                                      const CGFunctionInfo &FI,
    689                                      SourceLocation Loc = SourceLocation(),
    690                                      bool TLS = false);
    691 
    692   /// Return the address space of the underlying global variable for D, as
    693   /// determined by its declaration. Normally this is the same as the address
    694   /// space of D's type, but in CUDA, address spaces are associated with
    695   /// declarations, not types.
    696   unsigned GetGlobalVarAddressSpace(const VarDecl *D, unsigned AddrSpace);
    697 
    698   /// Return the llvm::Constant for the address of the given global variable.
    699   /// If Ty is non-null and if the global doesn't exist, then it will be greated
    700   /// with the specified type instead of whatever the normal requested type
    701   /// would be.
    702   llvm::Constant *GetAddrOfGlobalVar(const VarDecl *D,
    703                                      llvm::Type *Ty = nullptr);
    704 
    705   /// Return the address of the given function. If Ty is non-null, then this
    706   /// function will use the specified type if it has to create it.
    707   llvm::Constant *GetAddrOfFunction(GlobalDecl GD, llvm::Type *Ty = nullptr,
    708                                     bool ForVTable = false,
    709                                     bool DontDefer = false,
    710                                     bool IsForDefinition = false);
    711 
    712   /// Get the address of the RTTI descriptor for the given type.
    713   llvm::Constant *GetAddrOfRTTIDescriptor(QualType Ty, bool ForEH = false);
    714 
    715   /// Get the address of a uuid descriptor .
    716   ConstantAddress GetAddrOfUuidDescriptor(const CXXUuidofExpr* E);
    717 
    718   /// Get the address of the thunk for the given global decl.
    719   llvm::Constant *GetAddrOfThunk(GlobalDecl GD, const ThunkInfo &Thunk);
    720 
    721   /// Get a reference to the target of VD.
    722   ConstantAddress GetWeakRefReference(const ValueDecl *VD);
    723 
    724   /// Returns the assumed alignment of an opaque pointer to the given class.
    725   CharUnits getClassPointerAlignment(const CXXRecordDecl *CD);
    726 
    727   /// Returns the assumed alignment of a virtual base of a class.
    728   CharUnits getVBaseAlignment(CharUnits DerivedAlign,
    729                               const CXXRecordDecl *Derived,
    730                               const CXXRecordDecl *VBase);
    731 
    732   /// Given a class pointer with an actual known alignment, and the
    733   /// expected alignment of an object at a dynamic offset w.r.t that
    734   /// pointer, return the alignment to assume at the offset.
    735   CharUnits getDynamicOffsetAlignment(CharUnits ActualAlign,
    736                                       const CXXRecordDecl *Class,
    737                                       CharUnits ExpectedTargetAlign);
    738 
    739   CharUnits
    740   computeNonVirtualBaseClassOffset(const CXXRecordDecl *DerivedClass,
    741                                    CastExpr::path_const_iterator Start,
    742                                    CastExpr::path_const_iterator End);
    743 
    744   /// Returns the offset from a derived class to  a class. Returns null if the
    745   /// offset is 0.
    746   llvm::Constant *
    747   GetNonVirtualBaseClassOffset(const CXXRecordDecl *ClassDecl,
    748                                CastExpr::path_const_iterator PathBegin,
    749                                CastExpr::path_const_iterator PathEnd);
    750 
    751   llvm::FoldingSet<BlockByrefHelpers> ByrefHelpersCache;
    752 
    753   /// Fetches the global unique block count.
    754   int getUniqueBlockCount() { return ++Block.GlobalUniqueCount; }
    755 
    756   /// Fetches the type of a generic block descriptor.
    757   llvm::Type *getBlockDescriptorType();
    758 
    759   /// The type of a generic block literal.
    760   llvm::Type *getGenericBlockLiteralType();
    761 
    762   /// Gets the address of a block which requires no captures.
    763   llvm::Constant *GetAddrOfGlobalBlock(const BlockExpr *BE, const char *);
    764 
    765   /// Return a pointer to a constant CFString object for the given string.
    766   ConstantAddress GetAddrOfConstantCFString(const StringLiteral *Literal);
    767 
    768   /// Return a pointer to a constant NSString object for the given string. Or a
    769   /// user defined String object as defined via
    770   /// -fconstant-string-class=class_name option.
    771   ConstantAddress GetAddrOfConstantString(const StringLiteral *Literal);
    772 
    773   /// Return a constant array for the given string.
    774   llvm::Constant *GetConstantArrayFromStringLiteral(const StringLiteral *E);
    775 
    776   /// Return a pointer to a constant array for the given string literal.
    777   ConstantAddress
    778   GetAddrOfConstantStringFromLiteral(const StringLiteral *S,
    779                                      StringRef Name = ".str");
    780 
    781   /// Return a pointer to a constant array for the given ObjCEncodeExpr node.
    782   ConstantAddress
    783   GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *);
    784 
    785   /// Returns a pointer to a character array containing the literal and a
    786   /// terminating '\0' character. The result has pointer to array type.
    787   ///
    788   /// \param GlobalName If provided, the name to use for the global (if one is
    789   /// created).
    790   ConstantAddress
    791   GetAddrOfConstantCString(const std::string &Str,
    792                            const char *GlobalName = nullptr);
    793 
    794   /// Returns a pointer to a constant global variable for the given file-scope
    795   /// compound literal expression.
    796   ConstantAddress GetAddrOfConstantCompoundLiteral(const CompoundLiteralExpr*E);
    797 
    798   /// \brief Returns a pointer to a global variable representing a temporary
    799   /// with static or thread storage duration.
    800   ConstantAddress GetAddrOfGlobalTemporary(const MaterializeTemporaryExpr *E,
    801                                            const Expr *Inner);
    802 
    803   /// \brief Retrieve the record type that describes the state of an
    804   /// Objective-C fast enumeration loop (for..in).
    805   QualType getObjCFastEnumerationStateType();
    806 
    807   // Produce code for this constructor/destructor. This method doesn't try
    808   // to apply any ABI rules about which other constructors/destructors
    809   // are needed or if they are alias to each other.
    810   llvm::Function *codegenCXXStructor(const CXXMethodDecl *MD,
    811                                      StructorType Type);
    812 
    813   /// Return the address of the constructor/destructor of the given type.
    814   llvm::Constant *
    815   getAddrOfCXXStructor(const CXXMethodDecl *MD, StructorType Type,
    816                        const CGFunctionInfo *FnInfo = nullptr,
    817                        llvm::FunctionType *FnType = nullptr,
    818                        bool DontDefer = false, bool IsForDefinition = false);
    819 
    820   /// Given a builtin id for a function like "__builtin_fabsf", return a
    821   /// Function* for "fabsf".
    822   llvm::Value *getBuiltinLibFunction(const FunctionDecl *FD,
    823                                      unsigned BuiltinID);
    824 
    825   llvm::Function *getIntrinsic(unsigned IID, ArrayRef<llvm::Type*> Tys = None);
    826 
    827   /// Emit code for a single top level declaration.
    828   void EmitTopLevelDecl(Decl *D);
    829 
    830   /// \brief Stored a deferred empty coverage mapping for an unused
    831   /// and thus uninstrumented top level declaration.
    832   void AddDeferredUnusedCoverageMapping(Decl *D);
    833 
    834   /// \brief Remove the deferred empty coverage mapping as this
    835   /// declaration is actually instrumented.
    836   void ClearUnusedCoverageMapping(const Decl *D);
    837 
    838   /// \brief Emit all the deferred coverage mappings
    839   /// for the uninstrumented functions.
    840   void EmitDeferredUnusedCoverageMappings();
    841 
    842   /// Tell the consumer that this variable has been instantiated.
    843   void HandleCXXStaticMemberVarInstantiation(VarDecl *VD);
    844 
    845   /// \brief If the declaration has internal linkage but is inside an
    846   /// extern "C" linkage specification, prepare to emit an alias for it
    847   /// to the expected name.
    848   template<typename SomeDecl>
    849   void MaybeHandleStaticInExternC(const SomeDecl *D, llvm::GlobalValue *GV);
    850 
    851   /// Add a global to a list to be added to the llvm.used metadata.
    852   void addUsedGlobal(llvm::GlobalValue *GV);
    853 
    854   /// Add a global to a list to be added to the llvm.compiler.used metadata.
    855   void addCompilerUsedGlobal(llvm::GlobalValue *GV);
    856 
    857   /// Add a destructor and object to add to the C++ global destructor function.
    858   void AddCXXDtorEntry(llvm::Constant *DtorFn, llvm::Constant *Object) {
    859     CXXGlobalDtors.emplace_back(DtorFn, Object);
    860   }
    861 
    862   /// Create a new runtime function with the specified type and name.
    863   llvm::Constant *CreateRuntimeFunction(llvm::FunctionType *Ty,
    864                                         StringRef Name,
    865                                         llvm::AttributeSet ExtraAttrs =
    866                                           llvm::AttributeSet());
    867   /// Create a new compiler builtin function with the specified type and name.
    868   llvm::Constant *CreateBuiltinFunction(llvm::FunctionType *Ty,
    869                                         StringRef Name,
    870                                         llvm::AttributeSet ExtraAttrs =
    871                                           llvm::AttributeSet());
    872   /// Create a new runtime global variable with the specified type and name.
    873   llvm::Constant *CreateRuntimeVariable(llvm::Type *Ty,
    874                                         StringRef Name);
    875 
    876   ///@name Custom Blocks Runtime Interfaces
    877   ///@{
    878 
    879   llvm::Constant *getNSConcreteGlobalBlock();
    880   llvm::Constant *getNSConcreteStackBlock();
    881   llvm::Constant *getBlockObjectAssign();
    882   llvm::Constant *getBlockObjectDispose();
    883 
    884   ///@}
    885 
    886   llvm::Constant *getLLVMLifetimeStartFn();
    887   llvm::Constant *getLLVMLifetimeEndFn();
    888 
    889   // Make sure that this type is translated.
    890   void UpdateCompletedType(const TagDecl *TD);
    891 
    892   llvm::Constant *getMemberPointerConstant(const UnaryOperator *e);
    893 
    894   /// Try to emit the initializer for the given declaration as a constant;
    895   /// returns 0 if the expression cannot be emitted as a constant.
    896   llvm::Constant *EmitConstantInit(const VarDecl &D,
    897                                    CodeGenFunction *CGF = nullptr);
    898 
    899   /// Try to emit the given expression as a constant; returns 0 if the
    900   /// expression cannot be emitted as a constant.
    901   llvm::Constant *EmitConstantExpr(const Expr *E, QualType DestType,
    902                                    CodeGenFunction *CGF = nullptr);
    903 
    904   /// Emit the given constant value as a constant, in the type's scalar
    905   /// representation.
    906   llvm::Constant *EmitConstantValue(const APValue &Value, QualType DestType,
    907                                     CodeGenFunction *CGF = nullptr);
    908 
    909   /// Emit the given constant value as a constant, in the type's memory
    910   /// representation.
    911   llvm::Constant *EmitConstantValueForMemory(const APValue &Value,
    912                                              QualType DestType,
    913                                              CodeGenFunction *CGF = nullptr);
    914 
    915   /// \brief Emit type info if type of an expression is a variably modified
    916   /// type. Also emit proper debug info for cast types.
    917   void EmitExplicitCastExprType(const ExplicitCastExpr *E,
    918                                 CodeGenFunction *CGF = nullptr);
    919 
    920   /// Return the result of value-initializing the given type, i.e. a null
    921   /// expression of the given type.  This is usually, but not always, an LLVM
    922   /// null constant.
    923   llvm::Constant *EmitNullConstant(QualType T);
    924 
    925   /// Return a null constant appropriate for zero-initializing a base class with
    926   /// the given type. This is usually, but not always, an LLVM null constant.
    927   llvm::Constant *EmitNullConstantForBase(const CXXRecordDecl *Record);
    928 
    929   /// Emit a general error that something can't be done.
    930   void Error(SourceLocation loc, StringRef error);
    931 
    932   /// Print out an error that codegen doesn't support the specified stmt yet.
    933   void ErrorUnsupported(const Stmt *S, const char *Type);
    934 
    935   /// Print out an error that codegen doesn't support the specified decl yet.
    936   void ErrorUnsupported(const Decl *D, const char *Type);
    937 
    938   /// Set the attributes on the LLVM function for the given decl and function
    939   /// info. This applies attributes necessary for handling the ABI as well as
    940   /// user specified attributes like section.
    941   void SetInternalFunctionAttributes(const Decl *D, llvm::Function *F,
    942                                      const CGFunctionInfo &FI);
    943 
    944   /// Set the LLVM function attributes (sext, zext, etc).
    945   void SetLLVMFunctionAttributes(const Decl *D,
    946                                  const CGFunctionInfo &Info,
    947                                  llvm::Function *F);
    948 
    949   /// Set the LLVM function attributes which only apply to a function
    950   /// definition.
    951   void SetLLVMFunctionAttributesForDefinition(const Decl *D, llvm::Function *F);
    952 
    953   /// Return true iff the given type uses 'sret' when used as a return type.
    954   bool ReturnTypeUsesSRet(const CGFunctionInfo &FI);
    955 
    956   /// Return true iff the given type uses an argument slot when 'sret' is used
    957   /// as a return type.
    958   bool ReturnSlotInterferesWithArgs(const CGFunctionInfo &FI);
    959 
    960   /// Return true iff the given type uses 'fpret' when used as a return type.
    961   bool ReturnTypeUsesFPRet(QualType ResultType);
    962 
    963   /// Return true iff the given type uses 'fp2ret' when used as a return type.
    964   bool ReturnTypeUsesFP2Ret(QualType ResultType);
    965 
    966   /// Get the LLVM attributes and calling convention to use for a particular
    967   /// function type.
    968   ///
    969   /// \param Info - The function type information.
    970   /// \param CalleeInfo - The callee information these attributes are being
    971   /// constructed for. If valid, the attributes applied to this decl may
    972   /// contribute to the function attributes and calling convention.
    973   /// \param PAL [out] - On return, the attribute list to use.
    974   /// \param CallingConv [out] - On return, the LLVM calling convention to use.
    975   void ConstructAttributeList(const CGFunctionInfo &Info,
    976                               CGCalleeInfo CalleeInfo, AttributeListType &PAL,
    977                               unsigned &CallingConv, bool AttrOnCallSite);
    978 
    979   // Fills in the supplied string map with the set of target features for the
    980   // passed in function.
    981   void getFunctionFeatureMap(llvm::StringMap<bool> &FeatureMap,
    982                              const FunctionDecl *FD);
    983 
    984   StringRef getMangledName(GlobalDecl GD);
    985   StringRef getBlockMangledName(GlobalDecl GD, const BlockDecl *BD);
    986 
    987   void EmitTentativeDefinition(const VarDecl *D);
    988 
    989   void EmitVTable(CXXRecordDecl *Class);
    990 
    991   /// \brief Appends Opts to the "Linker Options" metadata value.
    992   void AppendLinkerOptions(StringRef Opts);
    993 
    994   /// \brief Appends a detect mismatch command to the linker options.
    995   void AddDetectMismatch(StringRef Name, StringRef Value);
    996 
    997   /// \brief Appends a dependent lib to the "Linker Options" metadata value.
    998   void AddDependentLib(StringRef Lib);
    999 
   1000   llvm::GlobalVariable::LinkageTypes getFunctionLinkage(GlobalDecl GD);
   1001 
   1002   void setFunctionLinkage(GlobalDecl GD, llvm::Function *F) {
   1003     F->setLinkage(getFunctionLinkage(GD));
   1004   }
   1005 
   1006   /// Set the DLL storage class on F.
   1007   void setFunctionDLLStorageClass(GlobalDecl GD, llvm::Function *F);
   1008 
   1009   /// Return the appropriate linkage for the vtable, VTT, and type information
   1010   /// of the given class.
   1011   llvm::GlobalVariable::LinkageTypes getVTableLinkage(const CXXRecordDecl *RD);
   1012 
   1013   /// Return the store size, in character units, of the given LLVM type.
   1014   CharUnits GetTargetTypeStoreSize(llvm::Type *Ty) const;
   1015 
   1016   /// Returns LLVM linkage for a declarator.
   1017   llvm::GlobalValue::LinkageTypes
   1018   getLLVMLinkageForDeclarator(const DeclaratorDecl *D, GVALinkage Linkage,
   1019                               bool IsConstantVariable);
   1020 
   1021   /// Returns LLVM linkage for a declarator.
   1022   llvm::GlobalValue::LinkageTypes
   1023   getLLVMLinkageVarDefinition(const VarDecl *VD, bool IsConstant);
   1024 
   1025   /// Emit all the global annotations.
   1026   void EmitGlobalAnnotations();
   1027 
   1028   /// Emit an annotation string.
   1029   llvm::Constant *EmitAnnotationString(StringRef Str);
   1030 
   1031   /// Emit the annotation's translation unit.
   1032   llvm::Constant *EmitAnnotationUnit(SourceLocation Loc);
   1033 
   1034   /// Emit the annotation line number.
   1035   llvm::Constant *EmitAnnotationLineNo(SourceLocation L);
   1036 
   1037   /// Generate the llvm::ConstantStruct which contains the annotation
   1038   /// information for a given GlobalValue. The annotation struct is
   1039   /// {i8 *, i8 *, i8 *, i32}. The first field is a constant expression, the
   1040   /// GlobalValue being annotated. The second field is the constant string
   1041   /// created from the AnnotateAttr's annotation. The third field is a constant
   1042   /// string containing the name of the translation unit. The fourth field is
   1043   /// the line number in the file of the annotated value declaration.
   1044   llvm::Constant *EmitAnnotateAttr(llvm::GlobalValue *GV,
   1045                                    const AnnotateAttr *AA,
   1046                                    SourceLocation L);
   1047 
   1048   /// Add global annotations that are set on D, for the global GV. Those
   1049   /// annotations are emitted during finalization of the LLVM code.
   1050   void AddGlobalAnnotations(const ValueDecl *D, llvm::GlobalValue *GV);
   1051 
   1052   bool isInSanitizerBlacklist(llvm::Function *Fn, SourceLocation Loc) const;
   1053 
   1054   bool isInSanitizerBlacklist(llvm::GlobalVariable *GV, SourceLocation Loc,
   1055                               QualType Ty,
   1056                               StringRef Category = StringRef()) const;
   1057 
   1058   SanitizerMetadata *getSanitizerMetadata() {
   1059     return SanitizerMD.get();
   1060   }
   1061 
   1062   void addDeferredVTable(const CXXRecordDecl *RD) {
   1063     DeferredVTables.push_back(RD);
   1064   }
   1065 
   1066   /// Emit code for a singal global function or var decl. Forward declarations
   1067   /// are emitted lazily.
   1068   void EmitGlobal(GlobalDecl D);
   1069 
   1070   bool TryEmitDefinitionAsAlias(GlobalDecl Alias, GlobalDecl Target,
   1071                                 bool InEveryTU);
   1072   bool TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D);
   1073 
   1074   /// Set attributes for a global definition.
   1075   void setFunctionDefinitionAttributes(const FunctionDecl *D,
   1076                                        llvm::Function *F);
   1077 
   1078   llvm::GlobalValue *GetGlobalValue(StringRef Ref);
   1079 
   1080   /// Set attributes which are common to any form of a global definition (alias,
   1081   /// Objective-C method, function, global variable).
   1082   ///
   1083   /// NOTE: This should only be called for definitions.
   1084   void SetCommonAttributes(const Decl *D, llvm::GlobalValue *GV);
   1085 
   1086   /// Set attributes which must be preserved by an alias. This includes common
   1087   /// attributes (i.e. it includes a call to SetCommonAttributes).
   1088   ///
   1089   /// NOTE: This should only be called for definitions.
   1090   void setAliasAttributes(const Decl *D, llvm::GlobalValue *GV);
   1091 
   1092   void addReplacement(StringRef Name, llvm::Constant *C);
   1093 
   1094   void addGlobalValReplacement(llvm::GlobalValue *GV, llvm::Constant *C);
   1095 
   1096   /// \brief Emit a code for threadprivate directive.
   1097   /// \param D Threadprivate declaration.
   1098   void EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D);
   1099 
   1100   /// Returns whether the given record is blacklisted from control flow
   1101   /// integrity checks.
   1102   bool IsCFIBlacklistedRecord(const CXXRecordDecl *RD);
   1103 
   1104   /// Emit bit set entries for the given vtable using the given layout if
   1105   /// vptr CFI is enabled.
   1106   void EmitVTableBitSetEntries(llvm::GlobalVariable *VTable,
   1107                                const VTableLayout &VTLayout);
   1108 
   1109   /// Generate a cross-DSO type identifier for type.
   1110   llvm::ConstantInt *CreateCfiIdForTypeMetadata(llvm::Metadata *MD);
   1111 
   1112   /// Create a metadata identifier for the given type. This may either be an
   1113   /// MDString (for external identifiers) or a distinct unnamed MDNode (for
   1114   /// internal identifiers).
   1115   llvm::Metadata *CreateMetadataIdentifierForType(QualType T);
   1116 
   1117   /// Create a bitset entry for the given function and add it to BitsetsMD.
   1118   void CreateFunctionBitSetEntry(const FunctionDecl *FD, llvm::Function *F);
   1119 
   1120   /// Create a bitset entry for the given vtable and add it to BitsetsMD.
   1121   void CreateVTableBitSetEntry(llvm::NamedMDNode *BitsetsMD,
   1122                                llvm::GlobalVariable *VTable, CharUnits Offset,
   1123                                const CXXRecordDecl *RD);
   1124 
   1125   /// \breif Get the declaration of std::terminate for the platform.
   1126   llvm::Constant *getTerminateFn();
   1127 
   1128 private:
   1129   llvm::Constant *
   1130   GetOrCreateLLVMFunction(StringRef MangledName, llvm::Type *Ty, GlobalDecl D,
   1131                           bool ForVTable, bool DontDefer = false,
   1132                           bool IsThunk = false,
   1133                           llvm::AttributeSet ExtraAttrs = llvm::AttributeSet(),
   1134                           bool IsForDefinition = false);
   1135 
   1136   llvm::Constant *GetOrCreateLLVMGlobal(StringRef MangledName,
   1137                                         llvm::PointerType *PTy,
   1138                                         const VarDecl *D);
   1139 
   1140   void setNonAliasAttributes(const Decl *D, llvm::GlobalObject *GO);
   1141 
   1142   /// Set function attributes for a function declaration.
   1143   void SetFunctionAttributes(GlobalDecl GD, llvm::Function *F,
   1144                              bool IsIncompleteFunction, bool IsThunk);
   1145 
   1146   void EmitGlobalDefinition(GlobalDecl D, llvm::GlobalValue *GV = nullptr);
   1147 
   1148   void EmitGlobalFunctionDefinition(GlobalDecl GD, llvm::GlobalValue *GV);
   1149   void EmitGlobalVarDefinition(const VarDecl *D);
   1150   void EmitAliasDefinition(GlobalDecl GD);
   1151   void EmitObjCPropertyImplementations(const ObjCImplementationDecl *D);
   1152   void EmitObjCIvarInitializations(ObjCImplementationDecl *D);
   1153 
   1154   // C++ related functions.
   1155 
   1156   void EmitNamespace(const NamespaceDecl *D);
   1157   void EmitLinkageSpec(const LinkageSpecDecl *D);
   1158   void CompleteDIClassType(const CXXMethodDecl* D);
   1159 
   1160   /// \brief Emit the function that initializes C++ thread_local variables.
   1161   void EmitCXXThreadLocalInitFunc();
   1162 
   1163   /// Emit the function that initializes C++ globals.
   1164   void EmitCXXGlobalInitFunc();
   1165 
   1166   /// Emit the function that destroys C++ globals.
   1167   void EmitCXXGlobalDtorFunc();
   1168 
   1169   /// Emit the function that initializes the specified global (if PerformInit is
   1170   /// true) and registers its destructor.
   1171   void EmitCXXGlobalVarDeclInitFunc(const VarDecl *D,
   1172                                     llvm::GlobalVariable *Addr,
   1173                                     bool PerformInit);
   1174 
   1175   void EmitPointerToInitFunc(const VarDecl *VD, llvm::GlobalVariable *Addr,
   1176                              llvm::Function *InitFunc, InitSegAttr *ISA);
   1177 
   1178   // FIXME: Hardcoding priority here is gross.
   1179   void AddGlobalCtor(llvm::Function *Ctor, int Priority = 65535,
   1180                      llvm::Constant *AssociatedData = nullptr);
   1181   void AddGlobalDtor(llvm::Function *Dtor, int Priority = 65535);
   1182 
   1183   /// Generates a global array of functions and priorities using the given list
   1184   /// and name. This array will have appending linkage and is suitable for use
   1185   /// as a LLVM constructor or destructor array.
   1186   void EmitCtorList(const CtorList &Fns, const char *GlobalName);
   1187 
   1188   /// Emit any needed decls for which code generation was deferred.
   1189   void EmitDeferred();
   1190 
   1191   /// Call replaceAllUsesWith on all pairs in Replacements.
   1192   void applyReplacements();
   1193 
   1194   /// Call replaceAllUsesWith on all pairs in GlobalValReplacements.
   1195   void applyGlobalValReplacements();
   1196 
   1197   void checkAliases();
   1198 
   1199   /// Emit any vtables which we deferred and still have a use for.
   1200   void EmitDeferredVTables();
   1201 
   1202   /// Emit the llvm.used and llvm.compiler.used metadata.
   1203   void emitLLVMUsed();
   1204 
   1205   /// \brief Emit the link options introduced by imported modules.
   1206   void EmitModuleLinkOptions();
   1207 
   1208   /// \brief Emit aliases for internal-linkage declarations inside "C" language
   1209   /// linkage specifications, giving them the "expected" name where possible.
   1210   void EmitStaticExternCAliases();
   1211 
   1212   void EmitDeclMetadata();
   1213 
   1214   /// \brief Emit the Clang version as llvm.ident metadata.
   1215   void EmitVersionIdentMetadata();
   1216 
   1217   /// Emits target specific Metadata for global declarations.
   1218   void EmitTargetMetadata();
   1219 
   1220   /// Emit the llvm.gcov metadata used to tell LLVM where to emit the .gcno and
   1221   /// .gcda files in a way that persists in .bc files.
   1222   void EmitCoverageFile();
   1223 
   1224   /// Emits the initializer for a uuidof string.
   1225   llvm::Constant *EmitUuidofInitializer(StringRef uuidstr);
   1226 
   1227   /// Determine whether the definition must be emitted; if this returns \c
   1228   /// false, the definition can be emitted lazily if it's used.
   1229   bool MustBeEmitted(const ValueDecl *D);
   1230 
   1231   /// Determine whether the definition can be emitted eagerly, or should be
   1232   /// delayed until the end of the translation unit. This is relevant for
   1233   /// definitions whose linkage can change, e.g. implicit function instantions
   1234   /// which may later be explicitly instantiated.
   1235   bool MayBeEmittedEagerly(const ValueDecl *D);
   1236 
   1237   /// Check whether we can use a "simpler", more core exceptions personality
   1238   /// function.
   1239   void SimplifyPersonality();
   1240 };
   1241 }  // end namespace CodeGen
   1242 }  // end namespace clang
   1243 
   1244 #endif // LLVM_CLANG_LIB_CODEGEN_CODEGENMODULE_H
   1245