CGDecl.cpp revision f6b89a173827457c28ac77b7cf091a24ef484e8a 
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  // FIXME: Merge attribute handling.
215  if (const AnnotateAttr *AA = D.getAttr<AnnotateAttr>()) {
216    SourceManager &SM = CGM.getContext().getSourceManager();
217    llvm::Constant *Ann =
218      CGM.EmitAnnotateAttr(GV, AA,
219                           SM.getInstantiationLineNumber(D.getLocation()));
220    CGM.AddAnnotation(Ann);
221  }
222
223  if (const SectionAttr *SA = D.getAttr<SectionAttr>())
224    GV->setSection(SA->getName());
225
226  if (D.hasAttr<UsedAttr>())
227    CGM.AddUsedGlobal(GV);
228
229  // We may have to cast the constant because of the initializer
230  // mismatch above.
231  //
232  // FIXME: It is really dangerous to store this in the map; if anyone
233  // RAUW's the GV uses of this constant will be invalid.
234  const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(D.getType());
235  const llvm::Type *LPtrTy =
236    llvm::PointerType::get(LTy, D.getType().getAddressSpace());
237  DMEntry = llvm::ConstantExpr::getBitCast(GV, LPtrTy);
238
239  // Emit global variable debug descriptor for static vars.
240  CGDebugInfo *DI = getDebugInfo();
241  if (DI) {
242    DI->setLocation(D.getLocation());
243    DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(GV), &D);
244  }
245}
246
247unsigned CodeGenFunction::getByRefValueLLVMField(const ValueDecl *VD) const {
248  assert(ByRefValueInfo.count(VD) && "Did not find value!");
249
250  return ByRefValueInfo.find(VD)->second.second;
251}
252
253/// BuildByRefType - This routine changes a __block variable declared as T x
254///   into:
255///
256///      struct {
257///        void *__isa;
258///        void *__forwarding;
259///        int32_t __flags;
260///        int32_t __size;
261///        void *__copy_helper;       // only if needed
262///        void *__destroy_helper;    // only if needed
263///        char padding[X];           // only if needed
264///        T x;
265///      } x
266///
267const llvm::Type *CodeGenFunction::BuildByRefType(const ValueDecl *D) {
268  std::pair<const llvm::Type *, unsigned> &Info = ByRefValueInfo[D];
269  if (Info.first)
270    return Info.first;
271
272  QualType Ty = D->getType();
273
274  std::vector<const llvm::Type *> Types;
275
276  const llvm::PointerType *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext);
277
278  llvm::PATypeHolder ByRefTypeHolder = llvm::OpaqueType::get(VMContext);
279
280  // void *__isa;
281  Types.push_back(Int8PtrTy);
282
283  // void *__forwarding;
284  Types.push_back(llvm::PointerType::getUnqual(ByRefTypeHolder));
285
286  // int32_t __flags;
287  Types.push_back(llvm::Type::getInt32Ty(VMContext));
288
289  // int32_t __size;
290  Types.push_back(llvm::Type::getInt32Ty(VMContext));
291
292  bool HasCopyAndDispose = BlockRequiresCopying(Ty);
293  if (HasCopyAndDispose) {
294    /// void *__copy_helper;
295    Types.push_back(Int8PtrTy);
296
297    /// void *__destroy_helper;
298    Types.push_back(Int8PtrTy);
299  }
300
301  bool Packed = false;
302  CharUnits Align = getContext().getDeclAlign(D);
303  if (Align > CharUnits::fromQuantity(Target.getPointerAlign(0) / 8)) {
304    // We have to insert padding.
305
306    // The struct above has 2 32-bit integers.
307    unsigned CurrentOffsetInBytes = 4 * 2;
308
309    // And either 2 or 4 pointers.
310    CurrentOffsetInBytes += (HasCopyAndDispose ? 4 : 2) *
311      CGM.getTargetData().getTypeAllocSize(Int8PtrTy);
312
313    // Align the offset.
314    unsigned AlignedOffsetInBytes =
315      llvm::RoundUpToAlignment(CurrentOffsetInBytes, Align.getQuantity());
316
317    unsigned NumPaddingBytes = AlignedOffsetInBytes - CurrentOffsetInBytes;
318    if (NumPaddingBytes > 0) {
319      const llvm::Type *Ty = llvm::Type::getInt8Ty(VMContext);
320      // FIXME: We need a sema error for alignment larger than the minimum of
321      // the maximal stack alignmint and the alignment of malloc on the system.
322      if (NumPaddingBytes > 1)
323        Ty = llvm::ArrayType::get(Ty, NumPaddingBytes);
324
325      Types.push_back(Ty);
326
327      // We want a packed struct.
328      Packed = true;
329    }
330  }
331
332  // T x;
333  Types.push_back(ConvertType(Ty));
334
335  const llvm::Type *T = llvm::StructType::get(VMContext, Types, Packed);
336
337  cast<llvm::OpaqueType>(ByRefTypeHolder.get())->refineAbstractTypeTo(T);
338  CGM.getModule().addTypeName("struct.__block_byref_" + D->getNameAsString(),
339                              ByRefTypeHolder.get());
340
341  Info.first = ByRefTypeHolder.get();
342
343  Info.second = Types.size() - 1;
344
345  return Info.first;
346}
347
348/// EmitLocalBlockVarDecl - Emit code and set up an entry in LocalDeclMap for a
349/// variable declaration with auto, register, or no storage class specifier.
350/// These turn into simple stack objects, or GlobalValues depending on target.
351void CodeGenFunction::EmitLocalBlockVarDecl(const VarDecl &D) {
352  QualType Ty = D.getType();
353  bool isByRef = D.hasAttr<BlocksAttr>();
354  bool needsDispose = false;
355  CharUnits Align = CharUnits::Zero();
356  bool IsSimpleConstantInitializer = false;
357
358  llvm::Value *DeclPtr;
359  if (Ty->isConstantSizeType()) {
360    if (!Target.useGlobalsForAutomaticVariables()) {
361
362      // If this value is an array or struct, is POD, and if the initializer is
363      // a staticly determinable constant, try to optimize it.
364      if (D.getInit() && !isByRef &&
365          (Ty->isArrayType() || Ty->isRecordType()) &&
366          Ty->isPODType() &&
367          D.getInit()->isConstantInitializer(getContext())) {
368        // If this variable is marked 'const', emit the value as a global.
369        if (CGM.getCodeGenOpts().MergeAllConstants &&
370            Ty.isConstant(getContext())) {
371          EmitStaticBlockVarDecl(D, llvm::GlobalValue::InternalLinkage);
372          return;
373        }
374
375        IsSimpleConstantInitializer = true;
376      }
377
378      // A normal fixed sized variable becomes an alloca in the entry block.
379      const llvm::Type *LTy = ConvertTypeForMem(Ty);
380      if (isByRef)
381        LTy = BuildByRefType(&D);
382      llvm::AllocaInst *Alloc = CreateTempAlloca(LTy);
383      Alloc->setName(D.getNameAsString());
384
385      Align = getContext().getDeclAlign(&D);
386      if (isByRef)
387        Align = std::max(Align,
388            CharUnits::fromQuantity(Target.getPointerAlign(0) / 8));
389      Alloc->setAlignment(Align.getQuantity());
390      DeclPtr = Alloc;
391    } else {
392      // Targets that don't support recursion emit locals as globals.
393      const char *Class =
394        D.getStorageClass() == VarDecl::Register ? ".reg." : ".auto.";
395      DeclPtr = CreateStaticBlockVarDecl(D, Class,
396                                         llvm::GlobalValue
397                                         ::InternalLinkage);
398    }
399
400    // FIXME: Can this happen?
401    if (Ty->isVariablyModifiedType())
402      EmitVLASize(Ty);
403  } else {
404    EnsureInsertPoint();
405
406    if (!DidCallStackSave) {
407      // Save the stack.
408      const llvm::Type *LTy = llvm::Type::getInt8PtrTy(VMContext);
409      llvm::Value *Stack = CreateTempAlloca(LTy, "saved_stack");
410
411      llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stacksave);
412      llvm::Value *V = Builder.CreateCall(F);
413
414      Builder.CreateStore(V, Stack);
415
416      DidCallStackSave = true;
417
418      {
419        // Push a cleanup block and restore the stack there.
420        DelayedCleanupBlock scope(*this);
421
422        V = Builder.CreateLoad(Stack, "tmp");
423        llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stackrestore);
424        Builder.CreateCall(F, V);
425      }
426    }
427
428    // Get the element type.
429    const llvm::Type *LElemTy = ConvertTypeForMem(Ty);
430    const llvm::Type *LElemPtrTy =
431      llvm::PointerType::get(LElemTy, D.getType().getAddressSpace());
432
433    llvm::Value *VLASize = EmitVLASize(Ty);
434
435    // Downcast the VLA size expression
436    VLASize = Builder.CreateIntCast(VLASize, llvm::Type::getInt32Ty(VMContext),
437                                    false, "tmp");
438
439    // Allocate memory for the array.
440    llvm::AllocaInst *VLA =
441      Builder.CreateAlloca(llvm::Type::getInt8Ty(VMContext), VLASize, "vla");
442    VLA->setAlignment(getContext().getDeclAlign(&D).getQuantity());
443
444    DeclPtr = Builder.CreateBitCast(VLA, LElemPtrTy, "tmp");
445  }
446
447  llvm::Value *&DMEntry = LocalDeclMap[&D];
448  assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
449  DMEntry = DeclPtr;
450
451  // Emit debug info for local var declaration.
452  if (CGDebugInfo *DI = getDebugInfo()) {
453    assert(HaveInsertPoint() && "Unexpected unreachable point!");
454
455    DI->setLocation(D.getLocation());
456    if (Target.useGlobalsForAutomaticVariables()) {
457      DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(DeclPtr), &D);
458    } else
459      DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder);
460  }
461
462  // If this local has an initializer, emit it now.
463  const Expr *Init = D.getInit();
464
465  // If we are at an unreachable point, we don't need to emit the initializer
466  // unless it contains a label.
467  if (!HaveInsertPoint()) {
468    if (!ContainsLabel(Init))
469      Init = 0;
470    else
471      EnsureInsertPoint();
472  }
473
474  if (Init) {
475    llvm::Value *Loc = DeclPtr;
476    if (isByRef)
477      Loc = Builder.CreateStructGEP(DeclPtr, getByRefValueLLVMField(&D),
478                                    D.getNameAsString());
479
480    bool isVolatile =
481      getContext().getCanonicalType(D.getType()).isVolatileQualified();
482
483    // If the initializer was a simple constant initializer, we can optimize it
484    // in various ways.
485    if (IsSimpleConstantInitializer) {
486      llvm::Constant *Init = CGM.EmitConstantExpr(D.getInit(),D.getType(),this);
487      assert(Init != 0 && "Wasn't a simple constant init?");
488
489      llvm::Value *AlignVal =
490        llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
491            Align.getQuantity());
492      const llvm::Type *IntPtr =
493        llvm::IntegerType::get(VMContext, LLVMPointerWidth);
494      llvm::Value *SizeVal =
495        llvm::ConstantInt::get(IntPtr,
496            getContext().getTypeSizeInChars(Ty).getQuantity());
497
498      const llvm::Type *BP = llvm::Type::getInt8PtrTy(VMContext);
499      if (Loc->getType() != BP)
500        Loc = Builder.CreateBitCast(Loc, BP, "tmp");
501
502      // If the initializer is all zeros, codegen with memset.
503      if (isa<llvm::ConstantAggregateZero>(Init)) {
504        llvm::Value *Zero =
505          llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 0);
506        Builder.CreateCall4(CGM.getMemSetFn(), Loc, Zero, SizeVal, AlignVal);
507      } else {
508        // Otherwise, create a temporary global with the initializer then
509        // memcpy from the global to the alloca.
510        std::string Name = GetStaticDeclName(*this, D, ".");
511        llvm::GlobalVariable *GV =
512          new llvm::GlobalVariable(CGM.getModule(), Init->getType(), true,
513                                   llvm::GlobalValue::InternalLinkage,
514                                   Init, Name, 0, false, 0);
515        GV->setAlignment(Align.getQuantity());
516
517        llvm::Value *SrcPtr = GV;
518        if (SrcPtr->getType() != BP)
519          SrcPtr = Builder.CreateBitCast(SrcPtr, BP, "tmp");
520
521        Builder.CreateCall4(CGM.getMemCpyFn(), Loc, SrcPtr, SizeVal, AlignVal);
522      }
523    } else if (Ty->isReferenceType()) {
524      RValue RV = EmitReferenceBindingToExpr(Init, /*IsInitializer=*/true);
525      EmitStoreOfScalar(RV.getScalarVal(), Loc, false, Ty);
526    } else if (!hasAggregateLLVMType(Init->getType())) {
527      llvm::Value *V = EmitScalarExpr(Init);
528      EmitStoreOfScalar(V, Loc, isVolatile, D.getType());
529    } else if (Init->getType()->isAnyComplexType()) {
530      EmitComplexExprIntoAddr(Init, Loc, isVolatile);
531    } else {
532      EmitAggExpr(Init, Loc, isVolatile);
533    }
534  }
535
536  if (isByRef) {
537    const llvm::PointerType *PtrToInt8Ty = llvm::Type::getInt8PtrTy(VMContext);
538
539    EnsureInsertPoint();
540    llvm::Value *isa_field = Builder.CreateStructGEP(DeclPtr, 0);
541    llvm::Value *forwarding_field = Builder.CreateStructGEP(DeclPtr, 1);
542    llvm::Value *flags_field = Builder.CreateStructGEP(DeclPtr, 2);
543    llvm::Value *size_field = Builder.CreateStructGEP(DeclPtr, 3);
544    llvm::Value *V;
545    int flag = 0;
546    int flags = 0;
547
548    needsDispose = true;
549
550    if (Ty->isBlockPointerType()) {
551      flag |= BLOCK_FIELD_IS_BLOCK;
552      flags |= BLOCK_HAS_COPY_DISPOSE;
553    } else if (BlockRequiresCopying(Ty)) {
554      flag |= BLOCK_FIELD_IS_OBJECT;
555      flags |= BLOCK_HAS_COPY_DISPOSE;
556    }
557
558    // FIXME: Someone double check this.
559    if (Ty.isObjCGCWeak())
560      flag |= BLOCK_FIELD_IS_WEAK;
561
562    int isa = 0;
563    if (flag&BLOCK_FIELD_IS_WEAK)
564      isa = 1;
565    V = llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), isa);
566    V = Builder.CreateIntToPtr(V, PtrToInt8Ty, "isa");
567    Builder.CreateStore(V, isa_field);
568
569    Builder.CreateStore(DeclPtr, forwarding_field);
570
571    V = llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), flags);
572    Builder.CreateStore(V, flags_field);
573
574    const llvm::Type *V1;
575    V1 = cast<llvm::PointerType>(DeclPtr->getType())->getElementType();
576    V = llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext),
577                               CGM.GetTargetTypeStoreSize(V1).getQuantity());
578    Builder.CreateStore(V, size_field);
579
580    if (flags & BLOCK_HAS_COPY_DISPOSE) {
581      BlockHasCopyDispose = true;
582      llvm::Value *copy_helper = Builder.CreateStructGEP(DeclPtr, 4);
583      Builder.CreateStore(BuildbyrefCopyHelper(DeclPtr->getType(), flag,
584                                               Align.getQuantity()),
585                          copy_helper);
586
587      llvm::Value *destroy_helper = Builder.CreateStructGEP(DeclPtr, 5);
588      Builder.CreateStore(BuildbyrefDestroyHelper(DeclPtr->getType(), flag,
589                                                  Align.getQuantity()),
590                          destroy_helper);
591    }
592  }
593
594  // Handle CXX destruction of variables.
595  QualType DtorTy(Ty);
596  while (const ArrayType *Array = getContext().getAsArrayType(DtorTy))
597    DtorTy = getContext().getBaseElementType(Array);
598  if (const RecordType *RT = DtorTy->getAs<RecordType>())
599    if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
600      if (!ClassDecl->hasTrivialDestructor()) {
601        const CXXDestructorDecl *D = ClassDecl->getDestructor(getContext());
602        assert(D && "EmitLocalBlockVarDecl - destructor is nul");
603
604        if (const ConstantArrayType *Array =
605              getContext().getAsConstantArrayType(Ty)) {
606          {
607            DelayedCleanupBlock Scope(*this);
608            QualType BaseElementTy = getContext().getBaseElementType(Array);
609            const llvm::Type *BasePtr = ConvertType(BaseElementTy);
610            BasePtr = llvm::PointerType::getUnqual(BasePtr);
611            llvm::Value *BaseAddrPtr =
612              Builder.CreateBitCast(DeclPtr, BasePtr);
613            EmitCXXAggrDestructorCall(D, Array, BaseAddrPtr);
614
615            // Make sure to jump to the exit block.
616            EmitBranch(Scope.getCleanupExitBlock());
617          }
618          if (Exceptions) {
619            EHCleanupBlock Cleanup(*this);
620            QualType BaseElementTy = getContext().getBaseElementType(Array);
621            const llvm::Type *BasePtr = ConvertType(BaseElementTy);
622            BasePtr = llvm::PointerType::getUnqual(BasePtr);
623            llvm::Value *BaseAddrPtr =
624              Builder.CreateBitCast(DeclPtr, BasePtr);
625            EmitCXXAggrDestructorCall(D, Array, BaseAddrPtr);
626          }
627        } else {
628          {
629            DelayedCleanupBlock Scope(*this);
630            EmitCXXDestructorCall(D, Dtor_Complete, DeclPtr);
631
632            // Make sure to jump to the exit block.
633            EmitBranch(Scope.getCleanupExitBlock());
634          }
635          if (Exceptions) {
636            EHCleanupBlock Cleanup(*this);
637            EmitCXXDestructorCall(D, Dtor_Complete, DeclPtr);
638          }
639        }
640      }
641  }
642
643  // Handle the cleanup attribute
644  if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) {
645    const FunctionDecl *FD = CA->getFunctionDecl();
646
647    llvm::Constant* F = CGM.GetAddrOfFunction(FD);
648    assert(F && "Could not find function!");
649
650    const CGFunctionInfo &Info = CGM.getTypes().getFunctionInfo(FD);
651
652    // In some cases, the type of the function argument will be different from
653    // the type of the pointer. An example of this is
654    // void f(void* arg);
655    // __attribute__((cleanup(f))) void *g;
656    //
657    // To fix this we insert a bitcast here.
658    QualType ArgTy = Info.arg_begin()->type;
659    {
660      DelayedCleanupBlock scope(*this);
661
662      CallArgList Args;
663      Args.push_back(std::make_pair(RValue::get(Builder.CreateBitCast(DeclPtr,
664                                                           ConvertType(ArgTy))),
665                                    getContext().getPointerType(D.getType())));
666      EmitCall(Info, F, ReturnValueSlot(), Args);
667    }
668    if (Exceptions) {
669      EHCleanupBlock Cleanup(*this);
670
671      CallArgList Args;
672      Args.push_back(std::make_pair(RValue::get(Builder.CreateBitCast(DeclPtr,
673                                                           ConvertType(ArgTy))),
674                                    getContext().getPointerType(D.getType())));
675      EmitCall(Info, F, ReturnValueSlot(), Args);
676    }
677  }
678
679  if (needsDispose && CGM.getLangOptions().getGCMode() != LangOptions::GCOnly) {
680    {
681      DelayedCleanupBlock scope(*this);
682      llvm::Value *V = Builder.CreateStructGEP(DeclPtr, 1, "forwarding");
683      V = Builder.CreateLoad(V);
684      BuildBlockRelease(V);
685    }
686    // FIXME: Turn this on and audit the codegen
687    if (0 && Exceptions) {
688      EHCleanupBlock Cleanup(*this);
689      llvm::Value *V = Builder.CreateStructGEP(DeclPtr, 1, "forwarding");
690      V = Builder.CreateLoad(V);
691      BuildBlockRelease(V);
692    }
693  }
694}
695
696/// Emit an alloca (or GlobalValue depending on target)
697/// for the specified parameter and set up LocalDeclMap.
698void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg) {
699  // FIXME: Why isn't ImplicitParamDecl a ParmVarDecl?
700  assert((isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)) &&
701         "Invalid argument to EmitParmDecl");
702  QualType Ty = D.getType();
703  CanQualType CTy = getContext().getCanonicalType(Ty);
704
705  llvm::Value *DeclPtr;
706  if (!Ty->isConstantSizeType()) {
707    // Variable sized values always are passed by-reference.
708    DeclPtr = Arg;
709  } else {
710    // A fixed sized single-value variable becomes an alloca in the entry block.
711    const llvm::Type *LTy = ConvertTypeForMem(Ty);
712    if (LTy->isSingleValueType()) {
713      // TODO: Alignment
714      DeclPtr = CreateTempAlloca(LTy);
715      DeclPtr->setName(D.getNameAsString() + llvm::StringRef(".addr"));
716
717      // Store the initial value into the alloca.
718      EmitStoreOfScalar(Arg, DeclPtr, CTy.isVolatileQualified(), Ty);
719    } else {
720      // Otherwise, if this is an aggregate, just use the input pointer.
721      DeclPtr = Arg;
722    }
723    Arg->setName(D.getNameAsString());
724  }
725
726  llvm::Value *&DMEntry = LocalDeclMap[&D];
727  assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
728  DMEntry = DeclPtr;
729
730  // Emit debug info for param declaration.
731  if (CGDebugInfo *DI = getDebugInfo()) {
732    DI->setLocation(D.getLocation());
733    DI->EmitDeclareOfArgVariable(&D, DeclPtr, Builder);
734  }
735}
736