CGDecl.cpp revision 0af9523607754a945b49d8a1ebae6631fc927921 
1//===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===//
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 contains code to emit Decl nodes as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CGDebugInfo.h"
15#include "CodeGenFunction.h"
16#include "CodeGenModule.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/CharUnits.h"
19#include "clang/AST/Decl.h"
20#include "clang/AST/DeclObjC.h"
21#include "clang/Basic/SourceManager.h"
22#include "clang/Basic/TargetInfo.h"
23#include "clang/CodeGen/CodeGenOptions.h"
24#include "llvm/GlobalVariable.h"
25#include "llvm/Intrinsics.h"
26#include "llvm/Target/TargetData.h"
27#include "llvm/Type.h"
28using namespace clang;
29using namespace CodeGen;
30
31
32void CodeGenFunction::EmitDecl(const Decl &D) {
33  switch (D.getKind()) {
34  default:
35    CGM.ErrorUnsupported(&D, "decl");
36    return;
37  case Decl::ParmVar:
38    assert(0 && "Parmdecls should not be in declstmts!");
39  case Decl::Function:  // void X();
40  case Decl::Record:    // struct/union/class X;
41  case Decl::Enum:      // enum X;
42  case Decl::EnumConstant: // enum ? { X = ? }
43  case Decl::CXXRecord: // struct/union/class X; [C++]
44  case Decl::Using:          // using X; [C++]
45  case Decl::UsingShadow:
46  case Decl::UsingDirective: // using namespace X; [C++]
47  case Decl::StaticAssert: // static_assert(X, ""); [C++0x]
48    // None of these decls require codegen support.
49    return;
50
51  case Decl::Var: {
52    const VarDecl &VD = cast<VarDecl>(D);
53    assert(VD.isBlockVarDecl() &&
54           "Should not see file-scope variables inside a function!");
55    return EmitBlockVarDecl(VD);
56  }
57
58  case Decl::Typedef: {   // typedef int X;
59    const TypedefDecl &TD = cast<TypedefDecl>(D);
60    QualType Ty = TD.getUnderlyingType();
61
62    if (Ty->isVariablyModifiedType())
63      EmitVLASize(Ty);
64  }
65  }
66}
67
68/// EmitBlockVarDecl - This method handles emission of any variable declaration
69/// inside a function, including static vars etc.
70void CodeGenFunction::EmitBlockVarDecl(const VarDecl &D) {
71  if (D.hasAttr<AsmLabelAttr>())
72    CGM.ErrorUnsupported(&D, "__asm__");
73
74  switch (D.getStorageClass()) {
75  case VarDecl::None:
76  case VarDecl::Auto:
77  case VarDecl::Register:
78    return EmitLocalBlockVarDecl(D);
79  case VarDecl::Static: {
80    llvm::GlobalValue::LinkageTypes Linkage =
81      llvm::GlobalValue::InternalLinkage;
82
83    // If this is a static declaration inside an inline function, it must have
84    // weak linkage so that the linker will merge multiple definitions of it.
85    if (getContext().getLangOptions().CPlusPlus) {
86      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CurFuncDecl)) {
87        if (FD->isInlined())
88          Linkage = llvm::GlobalValue::WeakAnyLinkage;
89      }
90    }
91
92    return EmitStaticBlockVarDecl(D, Linkage);
93  }
94  case VarDecl::Extern:
95  case VarDecl::PrivateExtern:
96    // Don't emit it now, allow it to be emitted lazily on its first use.
97    return;
98  }
99
100  assert(0 && "Unknown storage class");
101}
102
103static std::string GetStaticDeclName(CodeGenFunction &CGF, const VarDecl &D,
104                                     const char *Separator) {
105  CodeGenModule &CGM = CGF.CGM;
106  if (CGF.getContext().getLangOptions().CPlusPlus)
107    return CGM.getMangledName(&D);
108
109  std::string ContextName;
110  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CGF.CurFuncDecl))
111    ContextName = CGM.getMangledName(FD);
112  else if (isa<ObjCMethodDecl>(CGF.CurFuncDecl))
113    ContextName = CGF.CurFn->getName();
114  else
115    // FIXME: What about in a block??
116    assert(0 && "Unknown context for block var decl");
117
118  return ContextName + Separator + D.getNameAsString();
119}
120
121llvm::GlobalVariable *
122CodeGenFunction::CreateStaticBlockVarDecl(const VarDecl &D,
123                                          const char *Separator,
124                                      llvm::GlobalValue::LinkageTypes Linkage) {
125  QualType Ty = D.getType();
126  assert(Ty->isConstantSizeType() && "VLAs can't be static");
127
128  std::string Name = GetStaticDeclName(*this, D, Separator);
129
130  const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(Ty);
131  llvm::GlobalVariable *GV =
132    new llvm::GlobalVariable(CGM.getModule(), LTy,
133                             Ty.isConstant(getContext()), Linkage,
134                             CGM.EmitNullConstant(D.getType()), Name, 0,
135                             D.isThreadSpecified(), Ty.getAddressSpace());
136  GV->setAlignment(getContext().getDeclAlign(&D).getQuantity());
137  return GV;
138}
139
140/// AddInitializerToGlobalBlockVarDecl - Add the initializer for 'D' to the
141/// global variable that has already been created for it.  If the initializer
142/// has a different type than GV does, this may free GV and return a different
143/// one.  Otherwise it just returns GV.
144llvm::GlobalVariable *
145CodeGenFunction::AddInitializerToGlobalBlockVarDecl(const VarDecl &D,
146                                                    llvm::GlobalVariable *GV) {
147  llvm::Constant *Init = CGM.EmitConstantExpr(D.getInit(), D.getType(), this);
148
149  // If constant emission failed, then this should be a C++ static
150  // initializer.
151  if (!Init) {
152    if (!getContext().getLangOptions().CPlusPlus)
153      CGM.ErrorUnsupported(D.getInit(), "constant l-value expression");
154    else {
155      // Since we have a static initializer, this global variable can't
156      // be constant.
157      GV->setConstant(false);
158
159      EmitStaticCXXBlockVarDeclInit(D, GV);
160    }
161    return GV;
162  }
163
164  // The initializer may differ in type from the global. Rewrite
165  // the global to match the initializer.  (We have to do this
166  // because some types, like unions, can't be completely represented
167  // in the LLVM type system.)
168  if (GV->getType() != Init->getType()) {
169    llvm::GlobalVariable *OldGV = GV;
170
171    GV = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
172                                  OldGV->isConstant(),
173                                  OldGV->getLinkage(), Init, "",
174                                  0, D.isThreadSpecified(),
175                                  D.getType().getAddressSpace());
176
177    // Steal the name of the old global
178    GV->takeName(OldGV);
179
180    // Replace all uses of the old global with the new global
181    llvm::Constant *NewPtrForOldDecl =
182    llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
183    OldGV->replaceAllUsesWith(NewPtrForOldDecl);
184
185    // Erase the old global, since it is no longer used.
186    OldGV->eraseFromParent();
187  }
188
189  GV->setInitializer(Init);
190  return GV;
191}
192
193void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D,
194                                      llvm::GlobalValue::LinkageTypes Linkage) {
195  llvm::Value *&DMEntry = LocalDeclMap[&D];
196  assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
197
198  llvm::GlobalVariable *GV = CreateStaticBlockVarDecl(D, ".", Linkage);
199
200  // Store into LocalDeclMap before generating initializer to handle
201  // circular references.
202  DMEntry = GV;
203
204  // Make sure to evaluate VLA bounds now so that we have them for later.
205  //
206  // FIXME: Can this happen?
207  if (D.getType()->isVariablyModifiedType())
208    EmitVLASize(D.getType());
209
210  // If this value has an initializer, emit it.
211  if (D.getInit())
212    GV = AddInitializerToGlobalBlockVarDecl(D, GV);
213
214  GV->setAlignment(getContext().getDeclAlign(&D).getQuantity());
215
216  // FIXME: Merge attribute handling.
217  if (const AnnotateAttr *AA = D.getAttr<AnnotateAttr>()) {
218    SourceManager &SM = CGM.getContext().getSourceManager();
219    llvm::Constant *Ann =
220      CGM.EmitAnnotateAttr(GV, AA,
221                           SM.getInstantiationLineNumber(D.getLocation()));
222    CGM.AddAnnotation(Ann);
223  }
224
225  if (const SectionAttr *SA = D.getAttr<SectionAttr>())
226    GV->setSection(SA->getName());
227
228  if (D.hasAttr<UsedAttr>())
229    CGM.AddUsedGlobal(GV);
230
231  // We may have to cast the constant because of the initializer
232  // mismatch above.
233  //
234  // FIXME: It is really dangerous to store this in the map; if anyone
235  // RAUW's the GV uses of this constant will be invalid.
236  const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(D.getType());
237  const llvm::Type *LPtrTy =
238    llvm::PointerType::get(LTy, D.getType().getAddressSpace());
239  DMEntry = llvm::ConstantExpr::getBitCast(GV, LPtrTy);
240
241  // Emit global variable debug descriptor for static vars.
242  CGDebugInfo *DI = getDebugInfo();
243  if (DI) {
244    DI->setLocation(D.getLocation());
245    DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(GV), &D);
246  }
247}
248
249unsigned CodeGenFunction::getByRefValueLLVMField(const ValueDecl *VD) const {
250  assert(ByRefValueInfo.count(VD) && "Did not find value!");
251
252  return ByRefValueInfo.find(VD)->second.second;
253}
254
255/// BuildByRefType - This routine changes a __block variable declared as T x
256///   into:
257///
258///      struct {
259///        void *__isa;
260///        void *__forwarding;
261///        int32_t __flags;
262///        int32_t __size;
263///        void *__copy_helper;       // only if needed
264///        void *__destroy_helper;    // only if needed
265///        char padding[X];           // only if needed
266///        T x;
267///      } x
268///
269const llvm::Type *CodeGenFunction::BuildByRefType(const ValueDecl *D) {
270  std::pair<const llvm::Type *, unsigned> &Info = ByRefValueInfo[D];
271  if (Info.first)
272    return Info.first;
273
274  QualType Ty = D->getType();
275
276  std::vector<const llvm::Type *> Types;
277
278  const llvm::PointerType *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext);
279
280  llvm::PATypeHolder ByRefTypeHolder = llvm::OpaqueType::get(VMContext);
281
282  // void *__isa;
283  Types.push_back(Int8PtrTy);
284
285  // void *__forwarding;
286  Types.push_back(llvm::PointerType::getUnqual(ByRefTypeHolder));
287
288  // int32_t __flags;
289  Types.push_back(llvm::Type::getInt32Ty(VMContext));
290
291  // int32_t __size;
292  Types.push_back(llvm::Type::getInt32Ty(VMContext));
293
294  bool HasCopyAndDispose = BlockRequiresCopying(Ty);
295  if (HasCopyAndDispose) {
296    /// void *__copy_helper;
297    Types.push_back(Int8PtrTy);
298
299    /// void *__destroy_helper;
300    Types.push_back(Int8PtrTy);
301  }
302
303  bool Packed = false;
304  CharUnits Align = getContext().getDeclAlign(D);
305  if (Align > CharUnits::fromQuantity(Target.getPointerAlign(0) / 8)) {
306    // We have to insert padding.
307
308    // The struct above has 2 32-bit integers.
309    unsigned CurrentOffsetInBytes = 4 * 2;
310
311    // And either 2 or 4 pointers.
312    CurrentOffsetInBytes += (HasCopyAndDispose ? 4 : 2) *
313      CGM.getTargetData().getTypeAllocSize(Int8PtrTy);
314
315    // Align the offset.
316    unsigned AlignedOffsetInBytes =
317      llvm::RoundUpToAlignment(CurrentOffsetInBytes, Align.getQuantity());
318
319    unsigned NumPaddingBytes = AlignedOffsetInBytes - CurrentOffsetInBytes;
320    if (NumPaddingBytes > 0) {
321      const llvm::Type *Ty = llvm::Type::getInt8Ty(VMContext);
322      // FIXME: We need a sema error for alignment larger than the minimum of
323      // the maximal stack alignmint and the alignment of malloc on the system.
324      if (NumPaddingBytes > 1)
325        Ty = llvm::ArrayType::get(Ty, NumPaddingBytes);
326
327      Types.push_back(Ty);
328
329      // We want a packed struct.
330      Packed = true;
331    }
332  }
333
334  // T x;
335  Types.push_back(ConvertType(Ty));
336
337  const llvm::Type *T = llvm::StructType::get(VMContext, Types, Packed);
338
339  cast<llvm::OpaqueType>(ByRefTypeHolder.get())->refineAbstractTypeTo(T);
340  CGM.getModule().addTypeName("struct.__block_byref_" + D->getNameAsString(),
341                              ByRefTypeHolder.get());
342
343  Info.first = ByRefTypeHolder.get();
344
345  Info.second = Types.size() - 1;
346
347  return Info.first;
348}
349
350/// EmitLocalBlockVarDecl - Emit code and set up an entry in LocalDeclMap for a
351/// variable declaration with auto, register, or no storage class specifier.
352/// These turn into simple stack objects, or GlobalValues depending on target.
353void CodeGenFunction::EmitLocalBlockVarDecl(const VarDecl &D) {
354  QualType Ty = D.getType();
355  bool isByRef = D.hasAttr<BlocksAttr>();
356  bool needsDispose = false;
357  CharUnits Align = CharUnits::Zero();
358  bool IsSimpleConstantInitializer = false;
359
360  llvm::Value *DeclPtr;
361  if (Ty->isConstantSizeType()) {
362    if (!Target.useGlobalsForAutomaticVariables()) {
363
364      // If this value is an array or struct, is POD, and if the initializer is
365      // a staticly determinable constant, try to optimize it.
366      if (D.getInit() && !isByRef &&
367          (Ty->isArrayType() || Ty->isRecordType()) &&
368          Ty->isPODType() &&
369          D.getInit()->isConstantInitializer(getContext())) {
370        // If this variable is marked 'const', emit the value as a global.
371        if (CGM.getCodeGenOpts().MergeAllConstants &&
372            Ty.isConstant(getContext())) {
373          EmitStaticBlockVarDecl(D, llvm::GlobalValue::InternalLinkage);
374          return;
375        }
376
377        IsSimpleConstantInitializer = true;
378      }
379
380      // A normal fixed sized variable becomes an alloca in the entry block.
381      const llvm::Type *LTy = ConvertTypeForMem(Ty);
382      if (isByRef)
383        LTy = BuildByRefType(&D);
384      llvm::AllocaInst *Alloc = CreateTempAlloca(LTy);
385      Alloc->setName(D.getNameAsString());
386
387      Align = getContext().getDeclAlign(&D);
388      if (isByRef)
389        Align = std::max(Align,
390            CharUnits::fromQuantity(Target.getPointerAlign(0) / 8));
391      Alloc->setAlignment(Align.getQuantity());
392      DeclPtr = Alloc;
393    } else {
394      // Targets that don't support recursion emit locals as globals.
395      const char *Class =
396        D.getStorageClass() == VarDecl::Register ? ".reg." : ".auto.";
397      DeclPtr = CreateStaticBlockVarDecl(D, Class,
398                                         llvm::GlobalValue
399                                         ::InternalLinkage);
400    }
401
402    // FIXME: Can this happen?
403    if (Ty->isVariablyModifiedType())
404      EmitVLASize(Ty);
405  } else {
406    EnsureInsertPoint();
407
408    if (!DidCallStackSave) {
409      // Save the stack.
410      const llvm::Type *LTy = llvm::Type::getInt8PtrTy(VMContext);
411      llvm::Value *Stack = CreateTempAlloca(LTy, "saved_stack");
412
413      llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stacksave);
414      llvm::Value *V = Builder.CreateCall(F);
415
416      Builder.CreateStore(V, Stack);
417
418      DidCallStackSave = true;
419
420      {
421        // Push a cleanup block and restore the stack there.
422        DelayedCleanupBlock scope(*this);
423
424        V = Builder.CreateLoad(Stack, "tmp");
425        llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stackrestore);
426        Builder.CreateCall(F, V);
427      }
428    }
429
430    // Get the element type.
431    const llvm::Type *LElemTy = ConvertTypeForMem(Ty);
432    const llvm::Type *LElemPtrTy =
433      llvm::PointerType::get(LElemTy, D.getType().getAddressSpace());
434
435    llvm::Value *VLASize = EmitVLASize(Ty);
436
437    // Downcast the VLA size expression
438    VLASize = Builder.CreateIntCast(VLASize, llvm::Type::getInt32Ty(VMContext),
439                                    false, "tmp");
440
441    // Allocate memory for the array.
442    llvm::AllocaInst *VLA =
443      Builder.CreateAlloca(llvm::Type::getInt8Ty(VMContext), VLASize, "vla");
444    VLA->setAlignment(getContext().getDeclAlign(&D).getQuantity());
445
446    DeclPtr = Builder.CreateBitCast(VLA, LElemPtrTy, "tmp");
447  }
448
449  llvm::Value *&DMEntry = LocalDeclMap[&D];
450  assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
451  DMEntry = DeclPtr;
452
453  // Emit debug info for local var declaration.
454  if (CGDebugInfo *DI = getDebugInfo()) {
455    assert(HaveInsertPoint() && "Unexpected unreachable point!");
456
457    DI->setLocation(D.getLocation());
458    if (Target.useGlobalsForAutomaticVariables()) {
459      DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(DeclPtr), &D);
460    } else
461      DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder);
462  }
463
464  // If this local has an initializer, emit it now.
465  const Expr *Init = D.getInit();
466
467  // If we are at an unreachable point, we don't need to emit the initializer
468  // unless it contains a label.
469  if (!HaveInsertPoint()) {
470    if (!ContainsLabel(Init))
471      Init = 0;
472    else
473      EnsureInsertPoint();
474  }
475
476  if (Init) {
477    llvm::Value *Loc = DeclPtr;
478    if (isByRef)
479      Loc = Builder.CreateStructGEP(DeclPtr, getByRefValueLLVMField(&D),
480                                    D.getNameAsString());
481
482    bool isVolatile =
483      getContext().getCanonicalType(D.getType()).isVolatileQualified();
484
485    // If the initializer was a simple constant initializer, we can optimize it
486    // in various ways.
487    if (IsSimpleConstantInitializer) {
488      llvm::Constant *Init = CGM.EmitConstantExpr(D.getInit(),D.getType(),this);
489      assert(Init != 0 && "Wasn't a simple constant init?");
490
491      llvm::Value *AlignVal =
492        llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
493            Align.getQuantity());
494      const llvm::Type *IntPtr =
495        llvm::IntegerType::get(VMContext, LLVMPointerWidth);
496      llvm::Value *SizeVal =
497        llvm::ConstantInt::get(IntPtr,
498            getContext().getTypeSizeInChars(Ty).getQuantity());
499
500      const llvm::Type *BP = llvm::Type::getInt8PtrTy(VMContext);
501      if (Loc->getType() != BP)
502        Loc = Builder.CreateBitCast(Loc, BP, "tmp");
503
504      // If the initializer is all zeros, codegen with memset.
505      if (isa<llvm::ConstantAggregateZero>(Init)) {
506        llvm::Value *Zero =
507          llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 0);
508        Builder.CreateCall4(CGM.getMemSetFn(), Loc, Zero, SizeVal, AlignVal);
509      } else {
510        // Otherwise, create a temporary global with the initializer then
511        // memcpy from the global to the alloca.
512        std::string Name = GetStaticDeclName(*this, D, ".");
513        llvm::GlobalVariable *GV =
514          new llvm::GlobalVariable(CGM.getModule(), Init->getType(), true,
515                                   llvm::GlobalValue::InternalLinkage,
516                                   Init, Name, 0, false, 0);
517        GV->setAlignment(Align.getQuantity());
518
519        llvm::Value *SrcPtr = GV;
520        if (SrcPtr->getType() != BP)
521          SrcPtr = Builder.CreateBitCast(SrcPtr, BP, "tmp");
522
523        Builder.CreateCall4(CGM.getMemCpyFn(), Loc, SrcPtr, SizeVal, AlignVal);
524      }
525    } else if (Ty->isReferenceType()) {
526      RValue RV = EmitReferenceBindingToExpr(Init, /*IsInitializer=*/true);
527      EmitStoreOfScalar(RV.getScalarVal(), Loc, false, Ty);
528    } else if (!hasAggregateLLVMType(Init->getType())) {
529      llvm::Value *V = EmitScalarExpr(Init);
530      EmitStoreOfScalar(V, Loc, isVolatile, D.getType());
531    } else if (Init->getType()->isAnyComplexType()) {
532      EmitComplexExprIntoAddr(Init, Loc, isVolatile);
533    } else {
534      EmitAggExpr(Init, Loc, isVolatile);
535    }
536  }
537
538  if (isByRef) {
539    const llvm::PointerType *PtrToInt8Ty = llvm::Type::getInt8PtrTy(VMContext);
540
541    EnsureInsertPoint();
542    llvm::Value *isa_field = Builder.CreateStructGEP(DeclPtr, 0);
543    llvm::Value *forwarding_field = Builder.CreateStructGEP(DeclPtr, 1);
544    llvm::Value *flags_field = Builder.CreateStructGEP(DeclPtr, 2);
545    llvm::Value *size_field = Builder.CreateStructGEP(DeclPtr, 3);
546    llvm::Value *V;
547    int flag = 0;
548    int flags = 0;
549
550    needsDispose = true;
551
552    if (Ty->isBlockPointerType()) {
553      flag |= BLOCK_FIELD_IS_BLOCK;
554      flags |= BLOCK_HAS_COPY_DISPOSE;
555    } else if (BlockRequiresCopying(Ty)) {
556      flag |= BLOCK_FIELD_IS_OBJECT;
557      flags |= BLOCK_HAS_COPY_DISPOSE;
558    }
559
560    // FIXME: Someone double check this.
561    if (Ty.isObjCGCWeak())
562      flag |= BLOCK_FIELD_IS_WEAK;
563
564    int isa = 0;
565    if (flag&BLOCK_FIELD_IS_WEAK)
566      isa = 1;
567    V = llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), isa);
568    V = Builder.CreateIntToPtr(V, PtrToInt8Ty, "isa");
569    Builder.CreateStore(V, isa_field);
570
571    Builder.CreateStore(DeclPtr, forwarding_field);
572
573    V = llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), flags);
574    Builder.CreateStore(V, flags_field);
575
576    const llvm::Type *V1;
577    V1 = cast<llvm::PointerType>(DeclPtr->getType())->getElementType();
578    V = llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
579                               CGM.GetTargetTypeStoreSize(V1).getQuantity());
580    Builder.CreateStore(V, size_field);
581
582    if (flags & BLOCK_HAS_COPY_DISPOSE) {
583      BlockHasCopyDispose = true;
584      llvm::Value *copy_helper = Builder.CreateStructGEP(DeclPtr, 4);
585      Builder.CreateStore(BuildbyrefCopyHelper(DeclPtr->getType(), flag,
586                                               Align.getQuantity()),
587                          copy_helper);
588
589      llvm::Value *destroy_helper = Builder.CreateStructGEP(DeclPtr, 5);
590      Builder.CreateStore(BuildbyrefDestroyHelper(DeclPtr->getType(), flag,
591                                                  Align.getQuantity()),
592                          destroy_helper);
593    }
594  }
595
596  // Handle CXX destruction of variables.
597  QualType DtorTy(Ty);
598  while (const ArrayType *Array = getContext().getAsArrayType(DtorTy))
599    DtorTy = getContext().getBaseElementType(Array);
600  if (const RecordType *RT = DtorTy->getAs<RecordType>())
601    if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
602      if (!ClassDecl->hasTrivialDestructor()) {
603        const CXXDestructorDecl *D = ClassDecl->getDestructor(getContext());
604        assert(D && "EmitLocalBlockVarDecl - destructor is nul");
605
606        if (const ConstantArrayType *Array =
607              getContext().getAsConstantArrayType(Ty)) {
608          {
609            DelayedCleanupBlock Scope(*this);
610            QualType BaseElementTy = getContext().getBaseElementType(Array);
611            const llvm::Type *BasePtr = ConvertType(BaseElementTy);
612            BasePtr = llvm::PointerType::getUnqual(BasePtr);
613            llvm::Value *BaseAddrPtr =
614              Builder.CreateBitCast(DeclPtr, BasePtr);
615            EmitCXXAggrDestructorCall(D, Array, BaseAddrPtr);
616
617            // Make sure to jump to the exit block.
618            EmitBranch(Scope.getCleanupExitBlock());
619          }
620          if (Exceptions) {
621            EHCleanupBlock Cleanup(*this);
622            QualType BaseElementTy = getContext().getBaseElementType(Array);
623            const llvm::Type *BasePtr = ConvertType(BaseElementTy);
624            BasePtr = llvm::PointerType::getUnqual(BasePtr);
625            llvm::Value *BaseAddrPtr =
626              Builder.CreateBitCast(DeclPtr, BasePtr);
627            EmitCXXAggrDestructorCall(D, Array, BaseAddrPtr);
628          }
629        } else {
630          {
631            DelayedCleanupBlock Scope(*this);
632            EmitCXXDestructorCall(D, Dtor_Complete, DeclPtr);
633
634            // Make sure to jump to the exit block.
635            EmitBranch(Scope.getCleanupExitBlock());
636          }
637          if (Exceptions) {
638            EHCleanupBlock Cleanup(*this);
639            EmitCXXDestructorCall(D, Dtor_Complete, DeclPtr);
640          }
641        }
642      }
643  }
644
645  // Handle the cleanup attribute
646  if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) {
647    const FunctionDecl *FD = CA->getFunctionDecl();
648
649    llvm::Constant* F = CGM.GetAddrOfFunction(FD);
650    assert(F && "Could not find function!");
651
652    const CGFunctionInfo &Info = CGM.getTypes().getFunctionInfo(FD);
653
654    // In some cases, the type of the function argument will be different from
655    // the type of the pointer. An example of this is
656    // void f(void* arg);
657    // __attribute__((cleanup(f))) void *g;
658    //
659    // To fix this we insert a bitcast here.
660    QualType ArgTy = Info.arg_begin()->type;
661    {
662      DelayedCleanupBlock scope(*this);
663
664      CallArgList Args;
665      Args.push_back(std::make_pair(RValue::get(Builder.CreateBitCast(DeclPtr,
666                                                           ConvertType(ArgTy))),
667                                    getContext().getPointerType(D.getType())));
668      EmitCall(Info, F, ReturnValueSlot(), Args);
669    }
670    if (Exceptions) {
671      EHCleanupBlock Cleanup(*this);
672
673      CallArgList Args;
674      Args.push_back(std::make_pair(RValue::get(Builder.CreateBitCast(DeclPtr,
675                                                           ConvertType(ArgTy))),
676                                    getContext().getPointerType(D.getType())));
677      EmitCall(Info, F, ReturnValueSlot(), Args);
678    }
679  }
680
681  if (needsDispose && CGM.getLangOptions().getGCMode() != LangOptions::GCOnly) {
682    {
683      DelayedCleanupBlock scope(*this);
684      llvm::Value *V = Builder.CreateStructGEP(DeclPtr, 1, "forwarding");
685      V = Builder.CreateLoad(V);
686      BuildBlockRelease(V);
687    }
688    // FIXME: Turn this on and audit the codegen
689    if (0 && Exceptions) {
690      EHCleanupBlock Cleanup(*this);
691      llvm::Value *V = Builder.CreateStructGEP(DeclPtr, 1, "forwarding");
692      V = Builder.CreateLoad(V);
693      BuildBlockRelease(V);
694    }
695  }
696}
697
698/// Emit an alloca (or GlobalValue depending on target)
699/// for the specified parameter and set up LocalDeclMap.
700void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg) {
701  // FIXME: Why isn't ImplicitParamDecl a ParmVarDecl?
702  assert((isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)) &&
703         "Invalid argument to EmitParmDecl");
704  QualType Ty = D.getType();
705  CanQualType CTy = getContext().getCanonicalType(Ty);
706
707  llvm::Value *DeclPtr;
708  // If this is an aggregate or variable sized value, reuse the input pointer.
709  if (!Ty->isConstantSizeType() ||
710      CodeGenFunction::hasAggregateLLVMType(Ty)) {
711    DeclPtr = Arg;
712  } else {
713    // Otherwise, create a temporary to hold the value.
714    DeclPtr = CreateMemTemp(Ty, D.getName() + ".addr");
715
716    // Store the initial value into the alloca.
717    EmitStoreOfScalar(Arg, DeclPtr, CTy.isVolatileQualified(), Ty);
718  }
719  Arg->setName(D.getName());
720
721  llvm::Value *&DMEntry = LocalDeclMap[&D];
722  assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
723  DMEntry = DeclPtr;
724
725  // Emit debug info for param declaration.
726  if (CGDebugInfo *DI = getDebugInfo()) {
727    DI->setLocation(D.getLocation());
728    DI->EmitDeclareOfArgVariable(&D, DeclPtr, Builder);
729  }
730}
731