CodeGenModule.h revision 218893 
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 CLANG_CODEGEN_CODEGENMODULE_H
15#define CLANG_CODEGEN_CODEGENMODULE_H
16
17#include "clang/Basic/ABI.h"
18#include "clang/Basic/LangOptions.h"
19#include "clang/AST/Attr.h"
20#include "clang/AST/DeclCXX.h"
21#include "clang/AST/DeclObjC.h"
22#include "clang/AST/Mangle.h"
23#include "CGCall.h"
24#include "CGVTables.h"
25#include "CodeGenTypes.h"
26#include "GlobalDecl.h"
27#include "llvm/Module.h"
28#include "llvm/ADT/DenseMap.h"
29#include "llvm/ADT/StringMap.h"
30#include "llvm/ADT/StringSet.h"
31#include "llvm/ADT/SmallPtrSet.h"
32#include "llvm/Support/ValueHandle.h"
33
34namespace llvm {
35  class Module;
36  class Constant;
37  class Function;
38  class GlobalValue;
39  class TargetData;
40  class FunctionType;
41  class LLVMContext;
42}
43
44namespace clang {
45  class TargetCodeGenInfo;
46  class ASTContext;
47  class FunctionDecl;
48  class IdentifierInfo;
49  class ObjCMethodDecl;
50  class ObjCImplementationDecl;
51  class ObjCCategoryImplDecl;
52  class ObjCProtocolDecl;
53  class ObjCEncodeExpr;
54  class BlockExpr;
55  class CharUnits;
56  class Decl;
57  class Expr;
58  class Stmt;
59  class StringLiteral;
60  class NamedDecl;
61  class ValueDecl;
62  class VarDecl;
63  class LangOptions;
64  class CodeGenOptions;
65  class Diagnostic;
66  class AnnotateAttr;
67  class CXXDestructorDecl;
68  class MangleBuffer;
69
70namespace CodeGen {
71
72  class CodeGenFunction;
73  class CodeGenTBAA;
74  class CGCXXABI;
75  class CGDebugInfo;
76  class CGObjCRuntime;
77  class BlockFieldFlags;
78
79  struct OrderGlobalInits {
80    unsigned int priority;
81    unsigned int lex_order;
82    OrderGlobalInits(unsigned int p, unsigned int l)
83      : priority(p), lex_order(l) {}
84
85    bool operator==(const OrderGlobalInits &RHS) const {
86      return priority == RHS.priority &&
87             lex_order == RHS.lex_order;
88    }
89
90    bool operator<(const OrderGlobalInits &RHS) const {
91      if (priority < RHS.priority)
92        return true;
93
94      return priority == RHS.priority && lex_order < RHS.lex_order;
95    }
96  };
97
98  struct CodeGenTypeCache {
99    /// i8, i32, and i64
100    const llvm::IntegerType *Int8Ty, *Int32Ty, *Int64Ty;
101
102    /// int
103    const llvm::IntegerType *IntTy;
104
105    /// intptr_t and size_t, which we assume are the same
106    union {
107      const llvm::IntegerType *IntPtrTy;
108      const llvm::IntegerType *SizeTy;
109    };
110
111    /// void* in address space 0
112    union {
113      const llvm::PointerType *VoidPtrTy;
114      const llvm::PointerType *Int8PtrTy;
115    };
116
117    /// void** in address space 0
118    union {
119      const llvm::PointerType *VoidPtrPtrTy;
120      const llvm::PointerType *Int8PtrPtrTy;
121    };
122
123    /// The width of an address-zero pointer.
124    unsigned char PointerWidthInBits;
125  };
126
127/// CodeGenModule - This class organizes the cross-function state that is used
128/// while generating LLVM code.
129class CodeGenModule : public CodeGenTypeCache {
130  CodeGenModule(const CodeGenModule&);  // DO NOT IMPLEMENT
131  void operator=(const CodeGenModule&); // DO NOT IMPLEMENT
132
133  typedef std::vector<std::pair<llvm::Constant*, int> > CtorList;
134
135  ASTContext &Context;
136  const LangOptions &Features;
137  const CodeGenOptions &CodeGenOpts;
138  llvm::Module &TheModule;
139  const llvm::TargetData &TheTargetData;
140  mutable const TargetCodeGenInfo *TheTargetCodeGenInfo;
141  Diagnostic &Diags;
142  CGCXXABI &ABI;
143  CodeGenTypes Types;
144  CodeGenTBAA *TBAA;
145
146  /// VTables - Holds information about C++ vtables.
147  CodeGenVTables VTables;
148  friend class CodeGenVTables;
149
150  CGObjCRuntime* Runtime;
151  CGDebugInfo* DebugInfo;
152
153  // WeakRefReferences - A set of references that have only been seen via
154  // a weakref so far. This is used to remove the weak of the reference if we ever
155  // see a direct reference or a definition.
156  llvm::SmallPtrSet<llvm::GlobalValue*, 10> WeakRefReferences;
157
158  /// DeferredDecls - This contains all the decls which have definitions but
159  /// which are deferred for emission and therefore should only be output if
160  /// they are actually used.  If a decl is in this, then it is known to have
161  /// not been referenced yet.
162  llvm::StringMap<GlobalDecl> DeferredDecls;
163
164  /// DeferredDeclsToEmit - This is a list of deferred decls which we have seen
165  /// that *are* actually referenced.  These get code generated when the module
166  /// is done.
167  std::vector<GlobalDecl> DeferredDeclsToEmit;
168
169  /// LLVMUsed - List of global values which are required to be
170  /// present in the object file; bitcast to i8*. This is used for
171  /// forcing visibility of symbols which may otherwise be optimized
172  /// out.
173  std::vector<llvm::WeakVH> LLVMUsed;
174
175  /// GlobalCtors - Store the list of global constructors and their respective
176  /// priorities to be emitted when the translation unit is complete.
177  CtorList GlobalCtors;
178
179  /// GlobalDtors - Store the list of global destructors and their respective
180  /// priorities to be emitted when the translation unit is complete.
181  CtorList GlobalDtors;
182
183  /// MangledDeclNames - A map of canonical GlobalDecls to their mangled names.
184  llvm::DenseMap<GlobalDecl, llvm::StringRef> MangledDeclNames;
185  llvm::BumpPtrAllocator MangledNamesAllocator;
186
187  std::vector<llvm::Constant*> Annotations;
188
189  llvm::StringMap<llvm::Constant*> CFConstantStringMap;
190  llvm::StringMap<llvm::Constant*> ConstantStringMap;
191  llvm::DenseMap<const Decl*, llvm::Value*> StaticLocalDeclMap;
192
193  /// CXXGlobalInits - Global variables with initializers that need to run
194  /// before main.
195  std::vector<llvm::Constant*> CXXGlobalInits;
196
197  /// When a C++ decl with an initializer is deferred, null is
198  /// appended to CXXGlobalInits, and the index of that null is placed
199  /// here so that the initializer will be performed in the correct
200  /// order.
201  llvm::DenseMap<const Decl*, unsigned> DelayedCXXInitPosition;
202
203  /// - Global variables with initializers whose order of initialization
204  /// is set by init_priority attribute.
205
206  llvm::SmallVector<std::pair<OrderGlobalInits, llvm::Function*>, 8>
207    PrioritizedCXXGlobalInits;
208
209  /// CXXGlobalDtors - Global destructor functions and arguments that need to
210  /// run on termination.
211  std::vector<std::pair<llvm::WeakVH,llvm::Constant*> > CXXGlobalDtors;
212
213  /// CFConstantStringClassRef - Cached reference to the class for constant
214  /// strings. This value has type int * but is actually an Obj-C class pointer.
215  llvm::Constant *CFConstantStringClassRef;
216
217  /// ConstantStringClassRef - Cached reference to the class for constant
218  /// strings. This value has type int * but is actually an Obj-C class pointer.
219  llvm::Constant *ConstantStringClassRef;
220
221  /// Lazily create the Objective-C runtime
222  void createObjCRuntime();
223
224  llvm::LLVMContext &VMContext;
225
226  /// @name Cache for Blocks Runtime Globals
227  /// @{
228
229  const VarDecl *NSConcreteGlobalBlockDecl;
230  const VarDecl *NSConcreteStackBlockDecl;
231  llvm::Constant *NSConcreteGlobalBlock;
232  llvm::Constant *NSConcreteStackBlock;
233
234  const FunctionDecl *BlockObjectAssignDecl;
235  const FunctionDecl *BlockObjectDisposeDecl;
236  llvm::Constant *BlockObjectAssign;
237  llvm::Constant *BlockObjectDispose;
238
239  const llvm::Type *BlockDescriptorType;
240  const llvm::Type *GenericBlockLiteralType;
241
242  struct {
243    int GlobalUniqueCount;
244  } Block;
245
246  llvm::DenseMap<uint64_t, llvm::Constant *> AssignCache;
247  llvm::DenseMap<uint64_t, llvm::Constant *> DestroyCache;
248
249  /// @}
250public:
251  CodeGenModule(ASTContext &C, const CodeGenOptions &CodeGenOpts,
252                llvm::Module &M, const llvm::TargetData &TD, Diagnostic &Diags);
253
254  ~CodeGenModule();
255
256  /// Release - Finalize LLVM code generation.
257  void Release();
258
259  /// getObjCRuntime() - Return a reference to the configured
260  /// Objective-C runtime.
261  CGObjCRuntime &getObjCRuntime() {
262    if (!Runtime) createObjCRuntime();
263    return *Runtime;
264  }
265
266  /// hasObjCRuntime() - Return true iff an Objective-C runtime has
267  /// been configured.
268  bool hasObjCRuntime() { return !!Runtime; }
269
270  /// getCXXABI() - Return a reference to the configured C++ ABI.
271  CGCXXABI &getCXXABI() { return ABI; }
272
273  llvm::Value *getStaticLocalDeclAddress(const VarDecl *VD) {
274    return StaticLocalDeclMap[VD];
275  }
276  void setStaticLocalDeclAddress(const VarDecl *D,
277                             llvm::GlobalVariable *GV) {
278    StaticLocalDeclMap[D] = GV;
279  }
280
281  CGDebugInfo *getDebugInfo() { return DebugInfo; }
282  ASTContext &getContext() const { return Context; }
283  const CodeGenOptions &getCodeGenOpts() const { return CodeGenOpts; }
284  const LangOptions &getLangOptions() const { return Features; }
285  llvm::Module &getModule() const { return TheModule; }
286  CodeGenTypes &getTypes() { return Types; }
287  CodeGenVTables &getVTables() { return VTables; }
288  Diagnostic &getDiags() const { return Diags; }
289  const llvm::TargetData &getTargetData() const { return TheTargetData; }
290  const TargetInfo &getTarget() const { return Context.Target; }
291  llvm::LLVMContext &getLLVMContext() { return VMContext; }
292  const TargetCodeGenInfo &getTargetCodeGenInfo();
293  bool isTargetDarwin() const;
294
295  llvm::MDNode *getTBAAInfo(QualType QTy);
296
297  static void DecorateInstruction(llvm::Instruction *Inst,
298                                  llvm::MDNode *TBAAInfo);
299
300  /// setGlobalVisibility - Set the visibility for the given LLVM
301  /// GlobalValue.
302  void setGlobalVisibility(llvm::GlobalValue *GV, const NamedDecl *D) const;
303
304  /// TypeVisibilityKind - The kind of global variable that is passed to
305  /// setTypeVisibility
306  enum TypeVisibilityKind {
307    TVK_ForVTT,
308    TVK_ForVTable,
309    TVK_ForRTTI,
310    TVK_ForRTTIName
311  };
312
313  /// setTypeVisibility - Set the visibility for the given global
314  /// value which holds information about a type.
315  void setTypeVisibility(llvm::GlobalValue *GV, const CXXRecordDecl *D,
316                         TypeVisibilityKind TVK) const;
317
318  static llvm::GlobalValue::VisibilityTypes GetLLVMVisibility(Visibility V) {
319    switch (V) {
320    case DefaultVisibility:   return llvm::GlobalValue::DefaultVisibility;
321    case HiddenVisibility:    return llvm::GlobalValue::HiddenVisibility;
322    case ProtectedVisibility: return llvm::GlobalValue::ProtectedVisibility;
323    }
324    llvm_unreachable("unknown visibility!");
325    return llvm::GlobalValue::DefaultVisibility;
326  }
327
328  llvm::Constant *GetAddrOfGlobal(GlobalDecl GD) {
329    if (isa<CXXConstructorDecl>(GD.getDecl()))
330      return GetAddrOfCXXConstructor(cast<CXXConstructorDecl>(GD.getDecl()),
331                                     GD.getCtorType());
332    else if (isa<CXXDestructorDecl>(GD.getDecl()))
333      return GetAddrOfCXXDestructor(cast<CXXDestructorDecl>(GD.getDecl()),
334                                     GD.getDtorType());
335    else if (isa<FunctionDecl>(GD.getDecl()))
336      return GetAddrOfFunction(GD);
337    else
338      return GetAddrOfGlobalVar(cast<VarDecl>(GD.getDecl()));
339  }
340
341  /// CreateOrReplaceCXXRuntimeVariable - Will return a global variable of the given
342  /// type. If a variable with a different type already exists then a new
343  /// variable with the right type will be created and all uses of the old
344  /// variable will be replaced with a bitcast to the new variable.
345  llvm::GlobalVariable *
346  CreateOrReplaceCXXRuntimeVariable(llvm::StringRef Name, const llvm::Type *Ty,
347                                    llvm::GlobalValue::LinkageTypes Linkage);
348
349  /// GetAddrOfGlobalVar - Return the llvm::Constant for the address of the
350  /// given global variable.  If Ty is non-null and if the global doesn't exist,
351  /// then it will be greated with the specified type instead of whatever the
352  /// normal requested type would be.
353  llvm::Constant *GetAddrOfGlobalVar(const VarDecl *D,
354                                     const llvm::Type *Ty = 0);
355
356  /// GetAddrOfFunction - Return the address of the given function.  If Ty is
357  /// non-null, then this function will use the specified type if it has to
358  /// create it.
359  llvm::Constant *GetAddrOfFunction(GlobalDecl GD,
360                                    const llvm::Type *Ty = 0,
361                                    bool ForVTable = false);
362
363  /// GetAddrOfRTTIDescriptor - Get the address of the RTTI descriptor
364  /// for the given type.
365  llvm::Constant *GetAddrOfRTTIDescriptor(QualType Ty, bool ForEH = false);
366
367  /// GetAddrOfThunk - Get the address of the thunk for the given global decl.
368  llvm::Constant *GetAddrOfThunk(GlobalDecl GD, const ThunkInfo &Thunk);
369
370  /// GetWeakRefReference - Get a reference to the target of VD.
371  llvm::Constant *GetWeakRefReference(const ValueDecl *VD);
372
373  /// GetNonVirtualBaseClassOffset - Returns the offset from a derived class to
374  /// a class. Returns null if the offset is 0.
375  llvm::Constant *
376  GetNonVirtualBaseClassOffset(const CXXRecordDecl *ClassDecl,
377                               CastExpr::path_const_iterator PathBegin,
378                               CastExpr::path_const_iterator PathEnd);
379
380  llvm::Constant *BuildbyrefCopyHelper(const llvm::Type *T,
381                                       BlockFieldFlags flags,
382                                       unsigned Align,
383                                       const VarDecl *variable);
384  llvm::Constant *BuildbyrefDestroyHelper(const llvm::Type *T,
385                                          BlockFieldFlags flags,
386                                          unsigned Align,
387                                          const VarDecl *variable);
388
389  /// getGlobalUniqueCount - Fetches the global unique block count.
390  int getGlobalUniqueCount() { return ++Block.GlobalUniqueCount; }
391
392  /// getBlockDescriptorType - Fetches the type of a generic block
393  /// descriptor.
394  const llvm::Type *getBlockDescriptorType();
395
396  /// getGenericBlockLiteralType - The type of a generic block literal.
397  const llvm::Type *getGenericBlockLiteralType();
398
399  /// GetAddrOfGlobalBlock - Gets the address of a block which
400  /// requires no captures.
401  llvm::Constant *GetAddrOfGlobalBlock(const BlockExpr *BE, const char *);
402
403  /// GetStringForStringLiteral - Return the appropriate bytes for a string
404  /// literal, properly padded to match the literal type. If only the address of
405  /// a constant is needed consider using GetAddrOfConstantStringLiteral.
406  std::string GetStringForStringLiteral(const StringLiteral *E);
407
408  /// GetAddrOfConstantCFString - Return a pointer to a constant CFString object
409  /// for the given string.
410  llvm::Constant *GetAddrOfConstantCFString(const StringLiteral *Literal);
411
412  /// GetAddrOfConstantString - Return a pointer to a constant NSString object
413  /// for the given string. Or a user defined String object as defined via
414  /// -fconstant-string-class=class_name option.
415  llvm::Constant *GetAddrOfConstantString(const StringLiteral *Literal);
416
417  /// GetAddrOfConstantStringFromLiteral - Return a pointer to a constant array
418  /// for the given string literal.
419  llvm::Constant *GetAddrOfConstantStringFromLiteral(const StringLiteral *S);
420
421  /// GetAddrOfConstantStringFromObjCEncode - Return a pointer to a constant
422  /// array for the given ObjCEncodeExpr node.
423  llvm::Constant *GetAddrOfConstantStringFromObjCEncode(const ObjCEncodeExpr *);
424
425  /// GetAddrOfConstantString - Returns a pointer to a character array
426  /// containing the literal. This contents are exactly that of the given
427  /// string, i.e. it will not be null terminated automatically; see
428  /// GetAddrOfConstantCString. Note that whether the result is actually a
429  /// pointer to an LLVM constant depends on Feature.WriteableStrings.
430  ///
431  /// The result has pointer to array type.
432  ///
433  /// \param GlobalName If provided, the name to use for the global
434  /// (if one is created).
435  llvm::Constant *GetAddrOfConstantString(const std::string& str,
436                                          const char *GlobalName=0);
437
438  /// GetAddrOfConstantCString - Returns a pointer to a character array
439  /// containing the literal and a terminating '\0' character. The result has
440  /// pointer to array type.
441  ///
442  /// \param GlobalName If provided, the name to use for the global (if one is
443  /// created).
444  llvm::Constant *GetAddrOfConstantCString(const std::string &str,
445                                           const char *GlobalName=0);
446
447  /// GetAddrOfCXXConstructor - Return the address of the constructor of the
448  /// given type.
449  llvm::GlobalValue *GetAddrOfCXXConstructor(const CXXConstructorDecl *D,
450                                             CXXCtorType Type);
451
452  /// GetAddrOfCXXDestructor - Return the address of the constructor of the
453  /// given type.
454  llvm::GlobalValue *GetAddrOfCXXDestructor(const CXXDestructorDecl *D,
455                                            CXXDtorType Type);
456
457  /// getBuiltinLibFunction - Given a builtin id for a function like
458  /// "__builtin_fabsf", return a Function* for "fabsf".
459  llvm::Value *getBuiltinLibFunction(const FunctionDecl *FD,
460                                     unsigned BuiltinID);
461
462  llvm::Function *getIntrinsic(unsigned IID, const llvm::Type **Tys = 0,
463                               unsigned NumTys = 0);
464
465  /// EmitTopLevelDecl - Emit code for a single top level declaration.
466  void EmitTopLevelDecl(Decl *D);
467
468  /// AddUsedGlobal - Add a global which should be forced to be
469  /// present in the object file; these are emitted to the llvm.used
470  /// metadata global.
471  void AddUsedGlobal(llvm::GlobalValue *GV);
472
473  void AddAnnotation(llvm::Constant *C) { Annotations.push_back(C); }
474
475  /// AddCXXDtorEntry - Add a destructor and object to add to the C++ global
476  /// destructor function.
477  void AddCXXDtorEntry(llvm::Constant *DtorFn, llvm::Constant *Object) {
478    CXXGlobalDtors.push_back(std::make_pair(DtorFn, Object));
479  }
480
481  /// CreateRuntimeFunction - Create a new runtime function with the specified
482  /// type and name.
483  llvm::Constant *CreateRuntimeFunction(const llvm::FunctionType *Ty,
484                                        llvm::StringRef Name);
485  /// CreateRuntimeVariable - Create a new runtime global variable with the
486  /// specified type and name.
487  llvm::Constant *CreateRuntimeVariable(const llvm::Type *Ty,
488                                        llvm::StringRef Name);
489
490  ///@name Custom Blocks Runtime Interfaces
491  ///@{
492
493  llvm::Constant *getNSConcreteGlobalBlock();
494  llvm::Constant *getNSConcreteStackBlock();
495  llvm::Constant *getBlockObjectAssign();
496  llvm::Constant *getBlockObjectDispose();
497
498  ///@}
499
500  void UpdateCompletedType(const TagDecl *TD) {
501    // Make sure that this type is translated.
502    Types.UpdateCompletedType(TD);
503  }
504
505  llvm::Constant *getMemberPointerConstant(const UnaryOperator *e);
506
507  /// EmitConstantExpr - Try to emit the given expression as a
508  /// constant; returns 0 if the expression cannot be emitted as a
509  /// constant.
510  llvm::Constant *EmitConstantExpr(const Expr *E, QualType DestType,
511                                   CodeGenFunction *CGF = 0);
512
513  /// EmitNullConstant - Return the result of value-initializing the given
514  /// type, i.e. a null expression of the given type.  This is usually,
515  /// but not always, an LLVM null constant.
516  llvm::Constant *EmitNullConstant(QualType T);
517
518  llvm::Constant *EmitAnnotateAttr(llvm::GlobalValue *GV,
519                                   const AnnotateAttr *AA, unsigned LineNo);
520
521  /// ErrorUnsupported - Print out an error that codegen doesn't support the
522  /// specified stmt yet.
523  /// \param OmitOnError - If true, then this error should only be emitted if no
524  /// other errors have been reported.
525  void ErrorUnsupported(const Stmt *S, const char *Type,
526                        bool OmitOnError=false);
527
528  /// ErrorUnsupported - Print out an error that codegen doesn't support the
529  /// specified decl yet.
530  /// \param OmitOnError - If true, then this error should only be emitted if no
531  /// other errors have been reported.
532  void ErrorUnsupported(const Decl *D, const char *Type,
533                        bool OmitOnError=false);
534
535  /// SetInternalFunctionAttributes - Set the attributes on the LLVM
536  /// function for the given decl and function info. This applies
537  /// attributes necessary for handling the ABI as well as user
538  /// specified attributes like section.
539  void SetInternalFunctionAttributes(const Decl *D, llvm::Function *F,
540                                     const CGFunctionInfo &FI);
541
542  /// SetLLVMFunctionAttributes - Set the LLVM function attributes
543  /// (sext, zext, etc).
544  void SetLLVMFunctionAttributes(const Decl *D,
545                                 const CGFunctionInfo &Info,
546                                 llvm::Function *F);
547
548  /// SetLLVMFunctionAttributesForDefinition - Set the LLVM function attributes
549  /// which only apply to a function definintion.
550  void SetLLVMFunctionAttributesForDefinition(const Decl *D, llvm::Function *F);
551
552  /// ReturnTypeUsesSRet - Return true iff the given type uses 'sret' when used
553  /// as a return type.
554  bool ReturnTypeUsesSRet(const CGFunctionInfo &FI);
555
556  /// ReturnTypeUsesSret - Return true iff the given type uses 'fpret' when used
557  /// as a return type.
558  bool ReturnTypeUsesFPRet(QualType ResultType);
559
560  /// ConstructAttributeList - Get the LLVM attributes and calling convention to
561  /// use for a particular function type.
562  ///
563  /// \param Info - The function type information.
564  /// \param TargetDecl - The decl these attributes are being constructed
565  /// for. If supplied the attributes applied to this decl may contribute to the
566  /// function attributes and calling convention.
567  /// \param PAL [out] - On return, the attribute list to use.
568  /// \param CallingConv [out] - On return, the LLVM calling convention to use.
569  void ConstructAttributeList(const CGFunctionInfo &Info,
570                              const Decl *TargetDecl,
571                              AttributeListType &PAL,
572                              unsigned &CallingConv);
573
574  llvm::StringRef getMangledName(GlobalDecl GD);
575  void getBlockMangledName(GlobalDecl GD, MangleBuffer &Buffer,
576                           const BlockDecl *BD);
577
578  void EmitTentativeDefinition(const VarDecl *D);
579
580  void EmitVTable(CXXRecordDecl *Class, bool DefinitionRequired);
581
582  llvm::GlobalVariable::LinkageTypes
583  getFunctionLinkage(const FunctionDecl *FD);
584
585  void setFunctionLinkage(const FunctionDecl *FD, llvm::GlobalValue *V) {
586    V->setLinkage(getFunctionLinkage(FD));
587  }
588
589  /// getVTableLinkage - Return the appropriate linkage for the vtable, VTT,
590  /// and type information of the given class.
591  llvm::GlobalVariable::LinkageTypes getVTableLinkage(const CXXRecordDecl *RD);
592
593  /// GetTargetTypeStoreSize - Return the store size, in character units, of
594  /// the given LLVM type.
595  CharUnits GetTargetTypeStoreSize(const llvm::Type *Ty) const;
596
597  /// GetLLVMLinkageVarDefinition - Returns LLVM linkage for a global
598  /// variable.
599  llvm::GlobalValue::LinkageTypes
600  GetLLVMLinkageVarDefinition(const VarDecl *D,
601                              llvm::GlobalVariable *GV);
602
603  std::vector<const CXXRecordDecl*> DeferredVTables;
604
605private:
606  llvm::GlobalValue *GetGlobalValue(llvm::StringRef Ref);
607
608  llvm::Constant *GetOrCreateLLVMFunction(llvm::StringRef MangledName,
609                                          const llvm::Type *Ty,
610                                          GlobalDecl D,
611                                          bool ForVTable);
612  llvm::Constant *GetOrCreateLLVMGlobal(llvm::StringRef MangledName,
613                                        const llvm::PointerType *PTy,
614                                        const VarDecl *D,
615                                        bool UnnamedAddr = false);
616
617  /// SetCommonAttributes - Set attributes which are common to any
618  /// form of a global definition (alias, Objective-C method,
619  /// function, global variable).
620  ///
621  /// NOTE: This should only be called for definitions.
622  void SetCommonAttributes(const Decl *D, llvm::GlobalValue *GV);
623
624  /// SetFunctionDefinitionAttributes - Set attributes for a global definition.
625  void SetFunctionDefinitionAttributes(const FunctionDecl *D,
626                                       llvm::GlobalValue *GV);
627
628  /// SetFunctionAttributes - Set function attributes for a function
629  /// declaration.
630  void SetFunctionAttributes(GlobalDecl GD,
631                             llvm::Function *F,
632                             bool IsIncompleteFunction);
633
634  /// EmitGlobal - Emit code for a singal global function or var decl. Forward
635  /// declarations are emitted lazily.
636  void EmitGlobal(GlobalDecl D);
637
638  void EmitGlobalDefinition(GlobalDecl D);
639
640  void EmitGlobalFunctionDefinition(GlobalDecl GD);
641  void EmitGlobalVarDefinition(const VarDecl *D);
642  void EmitAliasDefinition(GlobalDecl GD);
643  void EmitObjCPropertyImplementations(const ObjCImplementationDecl *D);
644  void EmitObjCIvarInitializations(ObjCImplementationDecl *D);
645
646  // C++ related functions.
647
648  bool TryEmitDefinitionAsAlias(GlobalDecl Alias, GlobalDecl Target);
649  bool TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D);
650
651  void EmitNamespace(const NamespaceDecl *D);
652  void EmitLinkageSpec(const LinkageSpecDecl *D);
653
654  /// EmitCXXConstructors - Emit constructors (base, complete) from a
655  /// C++ constructor Decl.
656  void EmitCXXConstructors(const CXXConstructorDecl *D);
657
658  /// EmitCXXConstructor - Emit a single constructor with the given type from
659  /// a C++ constructor Decl.
660  void EmitCXXConstructor(const CXXConstructorDecl *D, CXXCtorType Type);
661
662  /// EmitCXXDestructors - Emit destructors (base, complete) from a
663  /// C++ destructor Decl.
664  void EmitCXXDestructors(const CXXDestructorDecl *D);
665
666  /// EmitCXXDestructor - Emit a single destructor with the given type from
667  /// a C++ destructor Decl.
668  void EmitCXXDestructor(const CXXDestructorDecl *D, CXXDtorType Type);
669
670  /// EmitCXXGlobalInitFunc - Emit the function that initializes C++ globals.
671  void EmitCXXGlobalInitFunc();
672
673  /// EmitCXXGlobalDtorFunc - Emit the function that destroys C++ globals.
674  void EmitCXXGlobalDtorFunc();
675
676  void EmitCXXGlobalVarDeclInitFunc(const VarDecl *D,
677                                    llvm::GlobalVariable *Addr);
678
679  // FIXME: Hardcoding priority here is gross.
680  void AddGlobalCtor(llvm::Function *Ctor, int Priority=65535);
681  void AddGlobalDtor(llvm::Function *Dtor, int Priority=65535);
682
683  /// EmitCtorList - Generates a global array of functions and priorities using
684  /// the given list and name. This array will have appending linkage and is
685  /// suitable for use as a LLVM constructor or destructor array.
686  void EmitCtorList(const CtorList &Fns, const char *GlobalName);
687
688  void EmitAnnotations(void);
689
690  /// EmitFundamentalRTTIDescriptor - Emit the RTTI descriptors for the
691  /// given type.
692  void EmitFundamentalRTTIDescriptor(QualType Type);
693
694  /// EmitFundamentalRTTIDescriptors - Emit the RTTI descriptors for the
695  /// builtin types.
696  void EmitFundamentalRTTIDescriptors();
697
698  /// EmitDeferred - Emit any needed decls for which code generation
699  /// was deferred.
700  void EmitDeferred(void);
701
702  /// EmitLLVMUsed - Emit the llvm.used metadata used to force
703  /// references to global which may otherwise be optimized out.
704  void EmitLLVMUsed(void);
705
706  void EmitDeclMetadata();
707
708  /// MayDeferGeneration - Determine if the given decl can be emitted
709  /// lazily; this is only relevant for definitions. The given decl
710  /// must be either a function or var decl.
711  bool MayDeferGeneration(const ValueDecl *D);
712
713  /// SimplifyPersonality - Check whether we can use a "simpler", more
714  /// core exceptions personality function.
715  void SimplifyPersonality();
716};
717}  // end namespace CodeGen
718}  // end namespace clang
719
720#endif
721