1 //===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This contains code to emit Decl nodes as LLVM code.
12 //===----------------------------------------------------------------------===//
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/Frontend/CodeGenOptions.h"
24 #include "llvm/GlobalVariable.h"
25 #include "llvm/Intrinsics.h"
26 #include "llvm/Target/TargetData.h"
27 #include "llvm/Type.h"
28 using namespace clang;
29 using namespace CodeGen;
32 void CodeGenFunction::EmitDecl(const Decl &D) {
33 switch (D.getKind()) {
34 case Decl::TranslationUnit:
36 case Decl::UnresolvedUsingTypename:
37 case Decl::ClassTemplateSpecialization:
38 case Decl::ClassTemplatePartialSpecialization:
39 case Decl::TemplateTypeParm:
40 case Decl::UnresolvedUsingValue:
41 case Decl::NonTypeTemplateParm:
43 case Decl::CXXConstructor:
44 case Decl::CXXDestructor:
45 case Decl::CXXConversion:
47 case Decl::IndirectField:
49 case Decl::ObjCAtDefsField:
51 case Decl::ImplicitParam:
52 case Decl::ClassTemplate:
53 case Decl::FunctionTemplate:
54 case Decl::TypeAliasTemplate:
55 case Decl::TemplateTemplateParm:
56 case Decl::ObjCMethod:
57 case Decl::ObjCCategory:
58 case Decl::ObjCProtocol:
59 case Decl::ObjCInterface:
60 case Decl::ObjCCategoryImpl:
61 case Decl::ObjCImplementation:
62 case Decl::ObjCProperty:
63 case Decl::ObjCCompatibleAlias:
64 case Decl::AccessSpec:
65 case Decl::LinkageSpec:
66 case Decl::ObjCPropertyImpl:
68 case Decl::ObjCForwardProtocol:
69 case Decl::FileScopeAsm:
71 case Decl::FriendTemplate:
73 assert(0 && "Declaration should not be in declstmts!");
74 case Decl::Function: // void X();
75 case Decl::Record: // struct/union/class X;
76 case Decl::Enum: // enum X;
77 case Decl::EnumConstant: // enum ? { X = ? }
78 case Decl::CXXRecord: // struct/union/class X; [C++]
79 case Decl::Using: // using X; [C++]
80 case Decl::UsingShadow:
81 case Decl::UsingDirective: // using namespace X; [C++]
82 case Decl::NamespaceAlias:
83 case Decl::StaticAssert: // static_assert(X, ""); [C++0x]
84 case Decl::Label: // __label__ x;
85 // None of these decls require codegen support.
89 const VarDecl &VD = cast<VarDecl>(D);
90 assert(VD.isLocalVarDecl() &&
91 "Should not see file-scope variables inside a function!");
92 return EmitVarDecl(VD);
95 case Decl::Typedef: // typedef int X;
96 case Decl::TypeAlias: { // using X = int; [C++0x]
97 const TypedefNameDecl &TD = cast<TypedefNameDecl>(D);
98 QualType Ty = TD.getUnderlyingType();
100 if (Ty->isVariablyModifiedType())
101 EmitVariablyModifiedType(Ty);
106 /// EmitVarDecl - This method handles emission of any variable declaration
107 /// inside a function, including static vars etc.
108 void CodeGenFunction::EmitVarDecl(const VarDecl &D) {
109 switch (D.getStorageClass()) {
113 return EmitAutoVarDecl(D);
115 llvm::GlobalValue::LinkageTypes Linkage =
116 llvm::GlobalValue::InternalLinkage;
118 // If the function definition has some sort of weak linkage, its
119 // static variables should also be weak so that they get properly
120 // uniqued. We can't do this in C, though, because there's no
121 // standard way to agree on which variables are the same (i.e.
122 // there's no mangling).
123 if (getContext().getLangOptions().CPlusPlus)
124 if (llvm::GlobalValue::isWeakForLinker(CurFn->getLinkage()))
125 Linkage = CurFn->getLinkage();
127 return EmitStaticVarDecl(D, Linkage);
130 case SC_PrivateExtern:
131 // Don't emit it now, allow it to be emitted lazily on its first use.
135 assert(0 && "Unknown storage class");
138 static std::string GetStaticDeclName(CodeGenFunction &CGF, const VarDecl &D,
139 const char *Separator) {
140 CodeGenModule &CGM = CGF.CGM;
141 if (CGF.getContext().getLangOptions().CPlusPlus) {
142 llvm::StringRef Name = CGM.getMangledName(&D);
146 std::string ContextName;
147 if (!CGF.CurFuncDecl) {
148 // Better be in a block declared in global scope.
149 const NamedDecl *ND = cast<NamedDecl>(&D);
150 const DeclContext *DC = ND->getDeclContext();
151 if (const BlockDecl *BD = dyn_cast<BlockDecl>(DC)) {
153 CGM.getBlockMangledName(GlobalDecl(), Name, BD);
154 ContextName = Name.getString();
157 assert(0 && "Unknown context for block static var decl");
158 } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CGF.CurFuncDecl)) {
159 llvm::StringRef Name = CGM.getMangledName(FD);
160 ContextName = Name.str();
161 } else if (isa<ObjCMethodDecl>(CGF.CurFuncDecl))
162 ContextName = CGF.CurFn->getName();
164 assert(0 && "Unknown context for static var decl");
166 return ContextName + Separator + D.getNameAsString();
169 llvm::GlobalVariable *
170 CodeGenFunction::CreateStaticVarDecl(const VarDecl &D,
171 const char *Separator,
172 llvm::GlobalValue::LinkageTypes Linkage) {
173 QualType Ty = D.getType();
174 assert(Ty->isConstantSizeType() && "VLAs can't be static");
176 std::string Name = GetStaticDeclName(*this, D, Separator);
178 const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(Ty);
179 llvm::GlobalVariable *GV =
180 new llvm::GlobalVariable(CGM.getModule(), LTy,
181 Ty.isConstant(getContext()), Linkage,
182 CGM.EmitNullConstant(D.getType()), Name, 0,
183 D.isThreadSpecified(),
184 CGM.getContext().getTargetAddressSpace(Ty));
185 GV->setAlignment(getContext().getDeclAlign(&D).getQuantity());
186 if (Linkage != llvm::GlobalValue::InternalLinkage)
187 GV->setVisibility(CurFn->getVisibility());
191 /// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
192 /// global variable that has already been created for it. If the initializer
193 /// has a different type than GV does, this may free GV and return a different
194 /// one. Otherwise it just returns GV.
195 llvm::GlobalVariable *
196 CodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D,
197 llvm::GlobalVariable *GV) {
198 llvm::Constant *Init = CGM.EmitConstantExpr(D.getInit(), D.getType(), this);
200 // If constant emission failed, then this should be a C++ static
203 if (!getContext().getLangOptions().CPlusPlus)
204 CGM.ErrorUnsupported(D.getInit(), "constant l-value expression");
205 else if (Builder.GetInsertBlock()) {
206 // Since we have a static initializer, this global variable can't
208 GV->setConstant(false);
210 EmitCXXGuardedInit(D, GV);
215 // The initializer may differ in type from the global. Rewrite
216 // the global to match the initializer. (We have to do this
217 // because some types, like unions, can't be completely represented
218 // in the LLVM type system.)
219 if (GV->getType()->getElementType() != Init->getType()) {
220 llvm::GlobalVariable *OldGV = GV;
222 GV = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
224 OldGV->getLinkage(), Init, "",
225 /*InsertBefore*/ OldGV,
226 D.isThreadSpecified(),
227 CGM.getContext().getTargetAddressSpace(D.getType()));
228 GV->setVisibility(OldGV->getVisibility());
230 // Steal the name of the old global
233 // Replace all uses of the old global with the new global
234 llvm::Constant *NewPtrForOldDecl =
235 llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
236 OldGV->replaceAllUsesWith(NewPtrForOldDecl);
238 // Erase the old global, since it is no longer used.
239 OldGV->eraseFromParent();
242 GV->setInitializer(Init);
246 void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
247 llvm::GlobalValue::LinkageTypes Linkage) {
248 llvm::Value *&DMEntry = LocalDeclMap[&D];
249 assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
251 llvm::GlobalVariable *GV = CreateStaticVarDecl(D, ".", Linkage);
253 // Store into LocalDeclMap before generating initializer to handle
254 // circular references.
257 // We can't have a VLA here, but we can have a pointer to a VLA,
258 // even though that doesn't really make any sense.
259 // Make sure to evaluate VLA bounds now so that we have them for later.
260 if (D.getType()->isVariablyModifiedType())
261 EmitVariablyModifiedType(D.getType());
263 // Local static block variables must be treated as globals as they may be
264 // referenced in their RHS initializer block-literal expresion.
265 CGM.setStaticLocalDeclAddress(&D, GV);
267 // If this value has an initializer, emit it.
269 GV = AddInitializerToStaticVarDecl(D, GV);
271 GV->setAlignment(getContext().getDeclAlign(&D).getQuantity());
273 // FIXME: Merge attribute handling.
274 if (const AnnotateAttr *AA = D.getAttr<AnnotateAttr>()) {
275 SourceManager &SM = CGM.getContext().getSourceManager();
276 llvm::Constant *Ann =
277 CGM.EmitAnnotateAttr(GV, AA,
278 SM.getInstantiationLineNumber(D.getLocation()));
279 CGM.AddAnnotation(Ann);
282 if (const SectionAttr *SA = D.getAttr<SectionAttr>())
283 GV->setSection(SA->getName());
285 if (D.hasAttr<UsedAttr>())
286 CGM.AddUsedGlobal(GV);
288 // We may have to cast the constant because of the initializer
291 // FIXME: It is really dangerous to store this in the map; if anyone
292 // RAUW's the GV uses of this constant will be invalid.
293 const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(D.getType());
294 const llvm::Type *LPtrTy =
295 LTy->getPointerTo(CGM.getContext().getTargetAddressSpace(D.getType()));
296 DMEntry = llvm::ConstantExpr::getBitCast(GV, LPtrTy);
298 // Emit global variable debug descriptor for static vars.
299 CGDebugInfo *DI = getDebugInfo();
301 DI->setLocation(D.getLocation());
302 DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(GV), &D);
307 struct DestroyObject : EHScopeStack::Cleanup {
308 DestroyObject(llvm::Value *addr, QualType type,
309 CodeGenFunction::Destroyer *destroyer,
310 bool useEHCleanupForArray)
311 : addr(addr), type(type), destroyer(*destroyer),
312 useEHCleanupForArray(useEHCleanupForArray) {}
316 CodeGenFunction::Destroyer &destroyer;
317 bool useEHCleanupForArray;
319 void Emit(CodeGenFunction &CGF, Flags flags) {
320 // Don't use an EH cleanup recursively from an EH cleanup.
321 bool useEHCleanupForArray =
322 flags.isForNormalCleanup() && this->useEHCleanupForArray;
324 CGF.emitDestroy(addr, type, destroyer, useEHCleanupForArray);
328 struct DestroyNRVOVariable : EHScopeStack::Cleanup {
329 DestroyNRVOVariable(llvm::Value *addr,
330 const CXXDestructorDecl *Dtor,
331 llvm::Value *NRVOFlag)
332 : Dtor(Dtor), NRVOFlag(NRVOFlag), Loc(addr) {}
334 const CXXDestructorDecl *Dtor;
335 llvm::Value *NRVOFlag;
338 void Emit(CodeGenFunction &CGF, Flags flags) {
339 // Along the exceptions path we always execute the dtor.
340 bool NRVO = flags.isForNormalCleanup() && NRVOFlag;
342 llvm::BasicBlock *SkipDtorBB = 0;
344 // If we exited via NRVO, we skip the destructor call.
345 llvm::BasicBlock *RunDtorBB = CGF.createBasicBlock("nrvo.unused");
346 SkipDtorBB = CGF.createBasicBlock("nrvo.skipdtor");
347 llvm::Value *DidNRVO = CGF.Builder.CreateLoad(NRVOFlag, "nrvo.val");
348 CGF.Builder.CreateCondBr(DidNRVO, SkipDtorBB, RunDtorBB);
349 CGF.EmitBlock(RunDtorBB);
352 CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete,
353 /*ForVirtualBase=*/false, Loc);
355 if (NRVO) CGF.EmitBlock(SkipDtorBB);
359 struct CallStackRestore : EHScopeStack::Cleanup {
361 CallStackRestore(llvm::Value *Stack) : Stack(Stack) {}
362 void Emit(CodeGenFunction &CGF, Flags flags) {
363 llvm::Value *V = CGF.Builder.CreateLoad(Stack, "tmp");
364 llvm::Value *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stackrestore);
365 CGF.Builder.CreateCall(F, V);
369 struct ExtendGCLifetime : EHScopeStack::Cleanup {
371 ExtendGCLifetime(const VarDecl *var) : Var(*var) {}
373 void Emit(CodeGenFunction &CGF, Flags flags) {
374 // Compute the address of the local variable, in case it's a
375 // byref or something.
376 DeclRefExpr DRE(const_cast<VarDecl*>(&Var), Var.getType(), VK_LValue,
378 llvm::Value *value = CGF.EmitLoadOfScalar(CGF.EmitDeclRefLValue(&DRE));
379 CGF.EmitExtendGCLifetime(value);
383 struct CallCleanupFunction : EHScopeStack::Cleanup {
384 llvm::Constant *CleanupFn;
385 const CGFunctionInfo &FnInfo;
388 CallCleanupFunction(llvm::Constant *CleanupFn, const CGFunctionInfo *Info,
390 : CleanupFn(CleanupFn), FnInfo(*Info), Var(*Var) {}
392 void Emit(CodeGenFunction &CGF, Flags flags) {
393 DeclRefExpr DRE(const_cast<VarDecl*>(&Var), Var.getType(), VK_LValue,
395 // Compute the address of the local variable, in case it's a byref
397 llvm::Value *Addr = CGF.EmitDeclRefLValue(&DRE).getAddress();
399 // In some cases, the type of the function argument will be different from
400 // the type of the pointer. An example of this is
401 // void f(void* arg);
402 // __attribute__((cleanup(f))) void *g;
404 // To fix this we insert a bitcast here.
405 QualType ArgTy = FnInfo.arg_begin()->type;
407 CGF.Builder.CreateBitCast(Addr, CGF.ConvertType(ArgTy));
410 Args.add(RValue::get(Arg),
411 CGF.getContext().getPointerType(Var.getType()));
412 CGF.EmitCall(FnInfo, CleanupFn, ReturnValueSlot(), Args);
417 /// EmitAutoVarWithLifetime - Does the setup required for an automatic
418 /// variable with lifetime.
419 static void EmitAutoVarWithLifetime(CodeGenFunction &CGF, const VarDecl &var,
421 Qualifiers::ObjCLifetime lifetime) {
423 case Qualifiers::OCL_None:
424 llvm_unreachable("present but none");
426 case Qualifiers::OCL_ExplicitNone:
430 case Qualifiers::OCL_Strong: {
431 CodeGenFunction::Destroyer &destroyer =
432 (var.hasAttr<ObjCPreciseLifetimeAttr>()
433 ? CodeGenFunction::destroyARCStrongPrecise
434 : CodeGenFunction::destroyARCStrongImprecise);
436 CleanupKind cleanupKind = CGF.getARCCleanupKind();
437 CGF.pushDestroy(cleanupKind, addr, var.getType(), destroyer,
438 cleanupKind & EHCleanup);
441 case Qualifiers::OCL_Autoreleasing:
445 case Qualifiers::OCL_Weak:
446 // __weak objects always get EH cleanups; otherwise, exceptions
447 // could cause really nasty crashes instead of mere leaks.
448 CGF.pushDestroy(NormalAndEHCleanup, addr, var.getType(),
449 CodeGenFunction::destroyARCWeak,
450 /*useEHCleanup*/ true);
455 static bool isAccessedBy(const VarDecl &var, const Stmt *s) {
456 if (const Expr *e = dyn_cast<Expr>(s)) {
457 // Skip the most common kinds of expressions that make
458 // hierarchy-walking expensive.
459 s = e = e->IgnoreParenCasts();
461 if (const DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e))
462 return (ref->getDecl() == &var);
465 for (Stmt::const_child_range children = s->children(); children; ++children)
466 // children might be null; as in missing decl or conditional of an if-stmt.
467 if ((*children) && isAccessedBy(var, *children))
473 static bool isAccessedBy(const ValueDecl *decl, const Expr *e) {
474 if (!decl) return false;
475 if (!isa<VarDecl>(decl)) return false;
476 const VarDecl *var = cast<VarDecl>(decl);
477 return isAccessedBy(*var, e);
480 static void drillIntoBlockVariable(CodeGenFunction &CGF,
482 const VarDecl *var) {
483 lvalue.setAddress(CGF.BuildBlockByrefAddress(lvalue.getAddress(), var));
486 void CodeGenFunction::EmitScalarInit(const Expr *init,
489 bool capturedByInit) {
490 Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
492 llvm::Value *value = EmitScalarExpr(init);
494 drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
495 EmitStoreThroughLValue(RValue::get(value), lvalue);
499 // If we're emitting a value with lifetime, we have to do the
500 // initialization *before* we leave the cleanup scopes.
501 CodeGenFunction::RunCleanupsScope Scope(*this);
502 if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(init))
503 init = ewc->getSubExpr();
505 // We have to maintain the illusion that the variable is
506 // zero-initialized. If the variable might be accessed in its
507 // initializer, zero-initialize before running the initializer, then
508 // actually perform the initialization with an assign.
509 bool accessedByInit = false;
510 if (lifetime != Qualifiers::OCL_ExplicitNone)
511 accessedByInit = isAccessedBy(D, init);
512 if (accessedByInit) {
513 LValue tempLV = lvalue;
514 // Drill down to the __block object if necessary.
515 if (capturedByInit) {
516 // We can use a simple GEP for this because it can't have been
518 tempLV.setAddress(Builder.CreateStructGEP(tempLV.getAddress(),
519 getByRefValueLLVMField(cast<VarDecl>(D))));
522 const llvm::PointerType *ty
523 = cast<llvm::PointerType>(tempLV.getAddress()->getType());
524 ty = cast<llvm::PointerType>(ty->getElementType());
526 llvm::Value *zero = llvm::ConstantPointerNull::get(ty);
528 // If __weak, we want to use a barrier under certain conditions.
529 if (lifetime == Qualifiers::OCL_Weak)
530 EmitARCInitWeak(tempLV.getAddress(), zero);
532 // Otherwise just do a simple store.
534 EmitStoreOfScalar(zero, tempLV);
537 // Emit the initializer.
538 llvm::Value *value = 0;
541 case Qualifiers::OCL_None:
542 llvm_unreachable("present but none");
544 case Qualifiers::OCL_ExplicitNone:
546 value = EmitScalarExpr(init);
549 case Qualifiers::OCL_Strong: {
550 value = EmitARCRetainScalarExpr(init);
554 case Qualifiers::OCL_Weak: {
555 // No way to optimize a producing initializer into this. It's not
556 // worth optimizing for, because the value will immediately
557 // disappear in the common case.
558 value = EmitScalarExpr(init);
560 if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
562 EmitARCStoreWeak(lvalue.getAddress(), value, /*ignored*/ true);
564 EmitARCInitWeak(lvalue.getAddress(), value);
568 case Qualifiers::OCL_Autoreleasing:
569 value = EmitARCRetainAutoreleaseScalarExpr(init);
573 if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
575 // If the variable might have been accessed by its initializer, we
576 // might have to initialize with a barrier. We have to do this for
577 // both __weak and __strong, but __weak got filtered out above.
578 if (accessedByInit && lifetime == Qualifiers::OCL_Strong) {
579 llvm::Value *oldValue = EmitLoadOfScalar(lvalue);
580 EmitStoreOfScalar(value, lvalue);
581 EmitARCRelease(oldValue, /*precise*/ false);
585 EmitStoreOfScalar(value, lvalue);
588 /// EmitScalarInit - Initialize the given lvalue with the given object.
589 void CodeGenFunction::EmitScalarInit(llvm::Value *init, LValue lvalue) {
590 Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
592 return EmitStoreThroughLValue(RValue::get(init), lvalue);
595 case Qualifiers::OCL_None:
596 llvm_unreachable("present but none");
598 case Qualifiers::OCL_ExplicitNone:
602 case Qualifiers::OCL_Strong:
603 init = EmitARCRetain(lvalue.getType(), init);
606 case Qualifiers::OCL_Weak:
607 // Initialize and then skip the primitive store.
608 EmitARCInitWeak(lvalue.getAddress(), init);
611 case Qualifiers::OCL_Autoreleasing:
612 init = EmitARCRetainAutorelease(lvalue.getType(), init);
616 EmitStoreOfScalar(init, lvalue);
619 /// canEmitInitWithFewStoresAfterMemset - Decide whether we can emit the
620 /// non-zero parts of the specified initializer with equal or fewer than
621 /// NumStores scalar stores.
622 static bool canEmitInitWithFewStoresAfterMemset(llvm::Constant *Init,
623 unsigned &NumStores) {
624 // Zero and Undef never requires any extra stores.
625 if (isa<llvm::ConstantAggregateZero>(Init) ||
626 isa<llvm::ConstantPointerNull>(Init) ||
627 isa<llvm::UndefValue>(Init))
629 if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) ||
630 isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) ||
631 isa<llvm::ConstantExpr>(Init))
632 return Init->isNullValue() || NumStores--;
634 // See if we can emit each element.
635 if (isa<llvm::ConstantArray>(Init) || isa<llvm::ConstantStruct>(Init)) {
636 for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
637 llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i));
638 if (!canEmitInitWithFewStoresAfterMemset(Elt, NumStores))
644 // Anything else is hard and scary.
648 /// emitStoresForInitAfterMemset - For inits that
649 /// canEmitInitWithFewStoresAfterMemset returned true for, emit the scalar
650 /// stores that would be required.
651 static void emitStoresForInitAfterMemset(llvm::Constant *Init, llvm::Value *Loc,
652 bool isVolatile, CGBuilderTy &Builder) {
653 // Zero doesn't require any stores.
654 if (isa<llvm::ConstantAggregateZero>(Init) ||
655 isa<llvm::ConstantPointerNull>(Init) ||
656 isa<llvm::UndefValue>(Init))
659 if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) ||
660 isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) ||
661 isa<llvm::ConstantExpr>(Init)) {
662 if (!Init->isNullValue())
663 Builder.CreateStore(Init, Loc, isVolatile);
667 assert((isa<llvm::ConstantStruct>(Init) || isa<llvm::ConstantArray>(Init)) &&
668 "Unknown value type!");
670 for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
671 llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i));
672 if (Elt->isNullValue()) continue;
674 // Otherwise, get a pointer to the element and emit it.
675 emitStoresForInitAfterMemset(Elt, Builder.CreateConstGEP2_32(Loc, 0, i),
676 isVolatile, Builder);
681 /// shouldUseMemSetPlusStoresToInitialize - Decide whether we should use memset
682 /// plus some stores to initialize a local variable instead of using a memcpy
683 /// from a constant global. It is beneficial to use memset if the global is all
684 /// zeros, or mostly zeros and large.
685 static bool shouldUseMemSetPlusStoresToInitialize(llvm::Constant *Init,
686 uint64_t GlobalSize) {
687 // If a global is all zeros, always use a memset.
688 if (isa<llvm::ConstantAggregateZero>(Init)) return true;
691 // If a non-zero global is <= 32 bytes, always use a memcpy. If it is large,
692 // do it if it will require 6 or fewer scalar stores.
693 // TODO: Should budget depends on the size? Avoiding a large global warrants
694 // plopping in more stores.
695 unsigned StoreBudget = 6;
696 uint64_t SizeLimit = 32;
698 return GlobalSize > SizeLimit &&
699 canEmitInitWithFewStoresAfterMemset(Init, StoreBudget);
703 /// EmitAutoVarDecl - Emit code and set up an entry in LocalDeclMap for a
704 /// variable declaration with auto, register, or no storage class specifier.
705 /// These turn into simple stack objects, or GlobalValues depending on target.
706 void CodeGenFunction::EmitAutoVarDecl(const VarDecl &D) {
707 AutoVarEmission emission = EmitAutoVarAlloca(D);
708 EmitAutoVarInit(emission);
709 EmitAutoVarCleanups(emission);
712 /// EmitAutoVarAlloca - Emit the alloca and debug information for a
713 /// local variable. Does not emit initalization or destruction.
714 CodeGenFunction::AutoVarEmission
715 CodeGenFunction::EmitAutoVarAlloca(const VarDecl &D) {
716 QualType Ty = D.getType();
718 AutoVarEmission emission(D);
720 bool isByRef = D.hasAttr<BlocksAttr>();
721 emission.IsByRef = isByRef;
723 CharUnits alignment = getContext().getDeclAlign(&D);
724 emission.Alignment = alignment;
726 // If the type is variably-modified, emit all the VLA sizes for it.
727 if (Ty->isVariablyModifiedType())
728 EmitVariablyModifiedType(Ty);
730 llvm::Value *DeclPtr;
731 if (Ty->isConstantSizeType()) {
732 if (!Target.useGlobalsForAutomaticVariables()) {
733 bool NRVO = getContext().getLangOptions().ElideConstructors &&
736 // If this value is a POD array or struct with a statically
737 // determinable constant initializer, there are optimizations we
739 // TODO: we can potentially constant-evaluate non-POD structs and
740 // arrays as long as the initialization is trivial (e.g. if they
741 // have a non-trivial destructor, but not a non-trivial constructor).
743 (Ty->isArrayType() || Ty->isRecordType()) &&
744 (Ty.isPODType(getContext()) ||
745 getContext().getBaseElementType(Ty)->isObjCObjectPointerType()) &&
746 D.getInit()->isConstantInitializer(getContext(), false)) {
748 // If the variable's a const type, and it's neither an NRVO
749 // candidate nor a __block variable, emit it as a global instead.
750 if (CGM.getCodeGenOpts().MergeAllConstants && Ty.isConstQualified() &&
752 EmitStaticVarDecl(D, llvm::GlobalValue::InternalLinkage);
754 emission.Address = 0; // signal this condition to later callbacks
755 assert(emission.wasEmittedAsGlobal());
759 // Otherwise, tell the initialization code that we're in this case.
760 emission.IsConstantAggregate = true;
763 // A normal fixed sized variable becomes an alloca in the entry block,
764 // unless it's an NRVO variable.
765 const llvm::Type *LTy = ConvertTypeForMem(Ty);
768 // The named return value optimization: allocate this variable in the
769 // return slot, so that we can elide the copy when returning this
770 // variable (C++0x [class.copy]p34).
771 DeclPtr = ReturnValue;
773 if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
774 if (!cast<CXXRecordDecl>(RecordTy->getDecl())->hasTrivialDestructor()) {
775 // Create a flag that is used to indicate when the NRVO was applied
776 // to this variable. Set it to zero to indicate that NRVO was not
778 llvm::Value *Zero = Builder.getFalse();
779 llvm::Value *NRVOFlag = CreateTempAlloca(Zero->getType(), "nrvo");
781 Builder.CreateStore(Zero, NRVOFlag);
783 // Record the NRVO flag for this variable.
784 NRVOFlags[&D] = NRVOFlag;
785 emission.NRVOFlag = NRVOFlag;
790 LTy = BuildByRefType(&D);
792 llvm::AllocaInst *Alloc = CreateTempAlloca(LTy);
793 Alloc->setName(D.getNameAsString());
795 CharUnits allocaAlignment = alignment;
797 allocaAlignment = std::max(allocaAlignment,
798 getContext().toCharUnitsFromBits(Target.getPointerAlign(0)));
799 Alloc->setAlignment(allocaAlignment.getQuantity());
803 // Targets that don't support recursion emit locals as globals.
805 D.getStorageClass() == SC_Register ? ".reg." : ".auto.";
806 DeclPtr = CreateStaticVarDecl(D, Class,
807 llvm::GlobalValue::InternalLinkage);
812 if (!DidCallStackSave) {
814 llvm::Value *Stack = CreateTempAlloca(Int8PtrTy, "saved_stack");
816 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stacksave);
817 llvm::Value *V = Builder.CreateCall(F);
819 Builder.CreateStore(V, Stack);
821 DidCallStackSave = true;
823 // Push a cleanup block and restore the stack there.
824 // FIXME: in general circumstances, this should be an EH cleanup.
825 EHStack.pushCleanup<CallStackRestore>(NormalCleanup, Stack);
828 llvm::Value *elementCount;
829 QualType elementType;
830 llvm::tie(elementCount, elementType) = getVLASize(Ty);
832 const llvm::Type *llvmTy = ConvertTypeForMem(elementType);
834 // Allocate memory for the array.
835 llvm::AllocaInst *vla = Builder.CreateAlloca(llvmTy, elementCount, "vla");
836 vla->setAlignment(alignment.getQuantity());
841 llvm::Value *&DMEntry = LocalDeclMap[&D];
842 assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
844 emission.Address = DeclPtr;
846 // Emit debug info for local var declaration.
847 if (HaveInsertPoint())
848 if (CGDebugInfo *DI = getDebugInfo()) {
849 DI->setLocation(D.getLocation());
850 if (Target.useGlobalsForAutomaticVariables()) {
851 DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(DeclPtr), &D);
853 DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder);
859 /// Determines whether the given __block variable is potentially
860 /// captured by the given expression.
861 static bool isCapturedBy(const VarDecl &var, const Expr *e) {
862 // Skip the most common kinds of expressions that make
863 // hierarchy-walking expensive.
864 e = e->IgnoreParenCasts();
866 if (const BlockExpr *be = dyn_cast<BlockExpr>(e)) {
867 const BlockDecl *block = be->getBlockDecl();
868 for (BlockDecl::capture_const_iterator i = block->capture_begin(),
869 e = block->capture_end(); i != e; ++i) {
870 if (i->getVariable() == &var)
874 // No need to walk into the subexpressions.
878 for (Stmt::const_child_range children = e->children(); children; ++children)
879 if (isCapturedBy(var, cast<Expr>(*children)))
885 /// \brief Determine whether the given initializer is trivial in the sense
886 /// that it requires no code to be generated.
887 static bool isTrivialInitializer(const Expr *Init) {
891 if (const CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init))
892 if (CXXConstructorDecl *Constructor = Construct->getConstructor())
893 if (Constructor->isTrivial() &&
894 Constructor->isDefaultConstructor() &&
895 !Construct->requiresZeroInitialization())
900 void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) {
901 assert(emission.Variable && "emission was not valid!");
903 // If this was emitted as a global constant, we're done.
904 if (emission.wasEmittedAsGlobal()) return;
906 const VarDecl &D = *emission.Variable;
907 QualType type = D.getType();
909 // If this local has an initializer, emit it now.
910 const Expr *Init = D.getInit();
912 // If we are at an unreachable point, we don't need to emit the initializer
913 // unless it contains a label.
914 if (!HaveInsertPoint()) {
915 if (!Init || !ContainsLabel(Init)) return;
919 // Initialize the structure of a __block variable.
920 if (emission.IsByRef)
921 emitByrefStructureInit(emission);
923 if (isTrivialInitializer(Init))
927 CharUnits alignment = emission.Alignment;
929 // Check whether this is a byref variable that's potentially
930 // captured and moved by its own initializer. If so, we'll need to
931 // emit the initializer first, then copy into the variable.
932 bool capturedByInit = emission.IsByRef && isCapturedBy(D, Init);
935 capturedByInit ? emission.Address : emission.getObjectAddress(*this);
937 if (!emission.IsConstantAggregate) {
938 LValue lv = MakeAddrLValue(Loc, type, alignment.getQuantity());
940 return EmitExprAsInit(Init, &D, lv, capturedByInit);
943 // If this is a simple aggregate initialization, we can optimize it
945 assert(!capturedByInit && "constant init contains a capturing block?");
947 bool isVolatile = type.isVolatileQualified();
949 llvm::Constant *constant = CGM.EmitConstantExpr(D.getInit(), type, this);
950 assert(constant != 0 && "Wasn't a simple constant init?");
952 llvm::Value *SizeVal =
953 llvm::ConstantInt::get(IntPtrTy,
954 getContext().getTypeSizeInChars(type).getQuantity());
956 const llvm::Type *BP = Int8PtrTy;
957 if (Loc->getType() != BP)
958 Loc = Builder.CreateBitCast(Loc, BP, "tmp");
960 // If the initializer is all or mostly zeros, codegen with memset then do
961 // a few stores afterward.
962 if (shouldUseMemSetPlusStoresToInitialize(constant,
963 CGM.getTargetData().getTypeAllocSize(constant->getType()))) {
964 Builder.CreateMemSet(Loc, llvm::ConstantInt::get(Int8Ty, 0), SizeVal,
965 alignment.getQuantity(), isVolatile);
966 if (!constant->isNullValue()) {
967 Loc = Builder.CreateBitCast(Loc, constant->getType()->getPointerTo());
968 emitStoresForInitAfterMemset(constant, Loc, isVolatile, Builder);
971 // Otherwise, create a temporary global with the initializer then
972 // memcpy from the global to the alloca.
973 std::string Name = GetStaticDeclName(*this, D, ".");
974 llvm::GlobalVariable *GV =
975 new llvm::GlobalVariable(CGM.getModule(), constant->getType(), true,
976 llvm::GlobalValue::InternalLinkage,
977 constant, Name, 0, false, 0);
978 GV->setAlignment(alignment.getQuantity());
979 GV->setUnnamedAddr(true);
981 llvm::Value *SrcPtr = GV;
982 if (SrcPtr->getType() != BP)
983 SrcPtr = Builder.CreateBitCast(SrcPtr, BP, "tmp");
985 Builder.CreateMemCpy(Loc, SrcPtr, SizeVal, alignment.getQuantity(),
990 /// Emit an expression as an initializer for a variable at the given
991 /// location. The expression is not necessarily the normal
992 /// initializer for the variable, and the address is not necessarily
993 /// its normal location.
995 /// \param init the initializing expression
996 /// \param var the variable to act as if we're initializing
997 /// \param loc the address to initialize; its type is a pointer
998 /// to the LLVM mapping of the variable's type
999 /// \param alignment the alignment of the address
1000 /// \param capturedByInit true if the variable is a __block variable
1001 /// whose address is potentially changed by the initializer
1002 void CodeGenFunction::EmitExprAsInit(const Expr *init,
1005 bool capturedByInit) {
1006 QualType type = D->getType();
1008 if (type->isReferenceType()) {
1009 RValue rvalue = EmitReferenceBindingToExpr(init, D);
1011 drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
1012 EmitStoreThroughLValue(rvalue, lvalue);
1013 } else if (!hasAggregateLLVMType(type)) {
1014 EmitScalarInit(init, D, lvalue, capturedByInit);
1015 } else if (type->isAnyComplexType()) {
1016 ComplexPairTy complex = EmitComplexExpr(init);
1018 drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
1019 StoreComplexToAddr(complex, lvalue.getAddress(), lvalue.isVolatile());
1021 // TODO: how can we delay here if D is captured by its initializer?
1022 EmitAggExpr(init, AggValueSlot::forLValue(lvalue, true, false));
1026 /// Enter a destroy cleanup for the given local variable.
1027 void CodeGenFunction::emitAutoVarTypeCleanup(
1028 const CodeGenFunction::AutoVarEmission &emission,
1029 QualType::DestructionKind dtorKind) {
1030 assert(dtorKind != QualType::DK_none);
1032 // Note that for __block variables, we want to destroy the
1033 // original stack object, not the possibly forwarded object.
1034 llvm::Value *addr = emission.getObjectAddress(*this);
1036 const VarDecl *var = emission.Variable;
1037 QualType type = var->getType();
1039 CleanupKind cleanupKind = NormalAndEHCleanup;
1040 CodeGenFunction::Destroyer *destroyer = 0;
1043 case QualType::DK_none:
1044 llvm_unreachable("no cleanup for trivially-destructible variable");
1046 case QualType::DK_cxx_destructor:
1047 // If there's an NRVO flag on the emission, we need a different
1049 if (emission.NRVOFlag) {
1050 assert(!type->isArrayType());
1051 CXXDestructorDecl *dtor = type->getAsCXXRecordDecl()->getDestructor();
1052 EHStack.pushCleanup<DestroyNRVOVariable>(cleanupKind, addr, dtor,
1058 case QualType::DK_objc_strong_lifetime:
1059 // Suppress cleanups for pseudo-strong variables.
1060 if (var->isARCPseudoStrong()) return;
1062 // Otherwise, consider whether to use an EH cleanup or not.
1063 cleanupKind = getARCCleanupKind();
1065 // Use the imprecise destroyer by default.
1066 if (!var->hasAttr<ObjCPreciseLifetimeAttr>())
1067 destroyer = CodeGenFunction::destroyARCStrongImprecise;
1070 case QualType::DK_objc_weak_lifetime:
1074 // If we haven't chosen a more specific destroyer, use the default.
1075 if (!destroyer) destroyer = &getDestroyer(dtorKind);
1077 // Use an EH cleanup in array destructors iff the destructor itself
1078 // is being pushed as an EH cleanup.
1079 bool useEHCleanup = (cleanupKind & EHCleanup);
1080 EHStack.pushCleanup<DestroyObject>(cleanupKind, addr, type, destroyer,
1084 void CodeGenFunction::EmitAutoVarCleanups(const AutoVarEmission &emission) {
1085 assert(emission.Variable && "emission was not valid!");
1087 // If this was emitted as a global constant, we're done.
1088 if (emission.wasEmittedAsGlobal()) return;
1090 const VarDecl &D = *emission.Variable;
1092 // Check the type for a cleanup.
1093 if (QualType::DestructionKind dtorKind = D.getType().isDestructedType())
1094 emitAutoVarTypeCleanup(emission, dtorKind);
1096 // In GC mode, honor objc_precise_lifetime.
1097 if (getLangOptions().getGCMode() != LangOptions::NonGC &&
1098 D.hasAttr<ObjCPreciseLifetimeAttr>()) {
1099 EHStack.pushCleanup<ExtendGCLifetime>(NormalCleanup, &D);
1102 // Handle the cleanup attribute.
1103 if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) {
1104 const FunctionDecl *FD = CA->getFunctionDecl();
1106 llvm::Constant *F = CGM.GetAddrOfFunction(FD);
1107 assert(F && "Could not find function!");
1109 const CGFunctionInfo &Info = CGM.getTypes().getFunctionInfo(FD);
1110 EHStack.pushCleanup<CallCleanupFunction>(NormalAndEHCleanup, F, &Info, &D);
1113 // If this is a block variable, call _Block_object_destroy
1114 // (on the unforwarded address).
1115 if (emission.IsByRef)
1116 enterByrefCleanup(emission);
1119 CodeGenFunction::Destroyer &
1120 CodeGenFunction::getDestroyer(QualType::DestructionKind kind) {
1121 // This is surprisingly compiler-dependent. GCC 4.2 can't bind
1122 // references to functions directly in returns, and using '*&foo'
1123 // confuses MSVC. Luckily, the following code pattern works in both.
1124 Destroyer *destroyer = 0;
1126 case QualType::DK_none: llvm_unreachable("no destroyer for trivial dtor");
1127 case QualType::DK_cxx_destructor:
1128 destroyer = &destroyCXXObject;
1130 case QualType::DK_objc_strong_lifetime:
1131 destroyer = &destroyARCStrongPrecise;
1133 case QualType::DK_objc_weak_lifetime:
1134 destroyer = &destroyARCWeak;
1140 /// pushDestroy - Push the standard destructor for the given type.
1141 void CodeGenFunction::pushDestroy(QualType::DestructionKind dtorKind,
1142 llvm::Value *addr, QualType type) {
1143 assert(dtorKind && "cannot push destructor for trivial type");
1145 CleanupKind cleanupKind = getCleanupKind(dtorKind);
1146 pushDestroy(cleanupKind, addr, type, getDestroyer(dtorKind),
1147 cleanupKind & EHCleanup);
1150 void CodeGenFunction::pushDestroy(CleanupKind cleanupKind, llvm::Value *addr,
1151 QualType type, Destroyer &destroyer,
1152 bool useEHCleanupForArray) {
1153 pushFullExprCleanup<DestroyObject>(cleanupKind, addr, type,
1154 destroyer, useEHCleanupForArray);
1157 /// emitDestroy - Immediately perform the destruction of the given
1160 /// \param addr - the address of the object; a type*
1161 /// \param type - the type of the object; if an array type, all
1162 /// objects are destroyed in reverse order
1163 /// \param destroyer - the function to call to destroy individual
1165 /// \param useEHCleanupForArray - whether an EH cleanup should be
1166 /// used when destroying array elements, in case one of the
1167 /// destructions throws an exception
1168 void CodeGenFunction::emitDestroy(llvm::Value *addr, QualType type,
1169 Destroyer &destroyer,
1170 bool useEHCleanupForArray) {
1171 const ArrayType *arrayType = getContext().getAsArrayType(type);
1173 return destroyer(*this, addr, type);
1175 llvm::Value *begin = addr;
1176 llvm::Value *length = emitArrayLength(arrayType, type, begin);
1178 // Normally we have to check whether the array is zero-length.
1179 bool checkZeroLength = true;
1181 // But if the array length is constant, we can suppress that.
1182 if (llvm::ConstantInt *constLength = dyn_cast<llvm::ConstantInt>(length)) {
1183 // ...and if it's constant zero, we can just skip the entire thing.
1184 if (constLength->isZero()) return;
1185 checkZeroLength = false;
1188 llvm::Value *end = Builder.CreateInBoundsGEP(begin, length);
1189 emitArrayDestroy(begin, end, type, destroyer,
1190 checkZeroLength, useEHCleanupForArray);
1193 /// emitArrayDestroy - Destroys all the elements of the given array,
1194 /// beginning from last to first. The array cannot be zero-length.
1196 /// \param begin - a type* denoting the first element of the array
1197 /// \param end - a type* denoting one past the end of the array
1198 /// \param type - the element type of the array
1199 /// \param destroyer - the function to call to destroy elements
1200 /// \param useEHCleanup - whether to push an EH cleanup to destroy
1201 /// the remaining elements in case the destruction of a single
1203 void CodeGenFunction::emitArrayDestroy(llvm::Value *begin,
1206 Destroyer &destroyer,
1207 bool checkZeroLength,
1208 bool useEHCleanup) {
1209 assert(!type->isArrayType());
1211 // The basic structure here is a do-while loop, because we don't
1212 // need to check for the zero-element case.
1213 llvm::BasicBlock *bodyBB = createBasicBlock("arraydestroy.body");
1214 llvm::BasicBlock *doneBB = createBasicBlock("arraydestroy.done");
1216 if (checkZeroLength) {
1217 llvm::Value *isEmpty = Builder.CreateICmpEQ(begin, end,
1218 "arraydestroy.isempty");
1219 Builder.CreateCondBr(isEmpty, doneBB, bodyBB);
1222 // Enter the loop body, making that address the current address.
1223 llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
1225 llvm::PHINode *elementPast =
1226 Builder.CreatePHI(begin->getType(), 2, "arraydestroy.elementPast");
1227 elementPast->addIncoming(end, entryBB);
1229 // Shift the address back by one element.
1230 llvm::Value *negativeOne = llvm::ConstantInt::get(SizeTy, -1, true);
1231 llvm::Value *element = Builder.CreateInBoundsGEP(elementPast, negativeOne,
1232 "arraydestroy.element");
1235 pushRegularPartialArrayCleanup(begin, element, type, destroyer);
1237 // Perform the actual destruction there.
1238 destroyer(*this, element, type);
1243 // Check whether we've reached the end.
1244 llvm::Value *done = Builder.CreateICmpEQ(element, begin, "arraydestroy.done");
1245 Builder.CreateCondBr(done, doneBB, bodyBB);
1246 elementPast->addIncoming(element, Builder.GetInsertBlock());
1252 /// Perform partial array destruction as if in an EH cleanup. Unlike
1253 /// emitArrayDestroy, the element type here may still be an array type.
1254 static void emitPartialArrayDestroy(CodeGenFunction &CGF,
1255 llvm::Value *begin, llvm::Value *end,
1257 CodeGenFunction::Destroyer &destroyer) {
1258 // If the element type is itself an array, drill down.
1259 unsigned arrayDepth = 0;
1260 while (const ArrayType *arrayType = CGF.getContext().getAsArrayType(type)) {
1261 // VLAs don't require a GEP index to walk into.
1262 if (!isa<VariableArrayType>(arrayType))
1264 type = arrayType->getElementType();
1268 llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, arrayDepth+1);
1270 llvm::SmallVector<llvm::Value*,4> gepIndices(arrayDepth, zero);
1271 begin = CGF.Builder.CreateInBoundsGEP(begin, gepIndices.begin(),
1272 gepIndices.end(), "pad.arraybegin");
1273 end = CGF.Builder.CreateInBoundsGEP(end, gepIndices.begin(),
1274 gepIndices.end(), "pad.arrayend");
1277 // Destroy the array. We don't ever need an EH cleanup because we
1278 // assume that we're in an EH cleanup ourselves, so a throwing
1279 // destructor causes an immediate terminate.
1280 CGF.emitArrayDestroy(begin, end, type, destroyer,
1281 /*checkZeroLength*/ true, /*useEHCleanup*/ false);
1285 /// RegularPartialArrayDestroy - a cleanup which performs a partial
1286 /// array destroy where the end pointer is regularly determined and
1287 /// does not need to be loaded from a local.
1288 class RegularPartialArrayDestroy : public EHScopeStack::Cleanup {
1289 llvm::Value *ArrayBegin;
1290 llvm::Value *ArrayEnd;
1291 QualType ElementType;
1292 CodeGenFunction::Destroyer &Destroyer;
1294 RegularPartialArrayDestroy(llvm::Value *arrayBegin, llvm::Value *arrayEnd,
1295 QualType elementType,
1296 CodeGenFunction::Destroyer *destroyer)
1297 : ArrayBegin(arrayBegin), ArrayEnd(arrayEnd),
1298 ElementType(elementType), Destroyer(*destroyer) {}
1300 void Emit(CodeGenFunction &CGF, Flags flags) {
1301 emitPartialArrayDestroy(CGF, ArrayBegin, ArrayEnd,
1302 ElementType, Destroyer);
1306 /// IrregularPartialArrayDestroy - a cleanup which performs a
1307 /// partial array destroy where the end pointer is irregularly
1308 /// determined and must be loaded from a local.
1309 class IrregularPartialArrayDestroy : public EHScopeStack::Cleanup {
1310 llvm::Value *ArrayBegin;
1311 llvm::Value *ArrayEndPointer;
1312 QualType ElementType;
1313 CodeGenFunction::Destroyer &Destroyer;
1315 IrregularPartialArrayDestroy(llvm::Value *arrayBegin,
1316 llvm::Value *arrayEndPointer,
1317 QualType elementType,
1318 CodeGenFunction::Destroyer *destroyer)
1319 : ArrayBegin(arrayBegin), ArrayEndPointer(arrayEndPointer),
1320 ElementType(elementType), Destroyer(*destroyer) {}
1322 void Emit(CodeGenFunction &CGF, Flags flags) {
1323 llvm::Value *arrayEnd = CGF.Builder.CreateLoad(ArrayEndPointer);
1324 emitPartialArrayDestroy(CGF, ArrayBegin, arrayEnd,
1325 ElementType, Destroyer);
1330 /// pushIrregularPartialArrayCleanup - Push an EH cleanup to destroy
1331 /// already-constructed elements of the given array. The cleanup
1332 /// may be popped with DeactivateCleanupBlock or PopCleanupBlock.
1334 /// \param elementType - the immediate element type of the array;
1335 /// possibly still an array type
1336 /// \param array - a value of type elementType*
1337 /// \param destructionKind - the kind of destruction required
1338 /// \param initializedElementCount - a value of type size_t* holding
1339 /// the number of successfully-constructed elements
1340 void CodeGenFunction::pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin,
1341 llvm::Value *arrayEndPointer,
1342 QualType elementType,
1343 Destroyer &destroyer) {
1344 pushFullExprCleanup<IrregularPartialArrayDestroy>(EHCleanup,
1345 arrayBegin, arrayEndPointer,
1346 elementType, &destroyer);
1349 /// pushRegularPartialArrayCleanup - Push an EH cleanup to destroy
1350 /// already-constructed elements of the given array. The cleanup
1351 /// may be popped with DeactivateCleanupBlock or PopCleanupBlock.
1353 /// \param elementType - the immediate element type of the array;
1354 /// possibly still an array type
1355 /// \param array - a value of type elementType*
1356 /// \param destructionKind - the kind of destruction required
1357 /// \param initializedElementCount - a value of type size_t* holding
1358 /// the number of successfully-constructed elements
1359 void CodeGenFunction::pushRegularPartialArrayCleanup(llvm::Value *arrayBegin,
1360 llvm::Value *arrayEnd,
1361 QualType elementType,
1362 Destroyer &destroyer) {
1363 pushFullExprCleanup<RegularPartialArrayDestroy>(EHCleanup,
1364 arrayBegin, arrayEnd,
1365 elementType, &destroyer);
1369 /// A cleanup to perform a release of an object at the end of a
1370 /// function. This is used to balance out the incoming +1 of a
1371 /// ns_consumed argument when we can't reasonably do that just by
1372 /// not doing the initial retain for a __block argument.
1373 struct ConsumeARCParameter : EHScopeStack::Cleanup {
1374 ConsumeARCParameter(llvm::Value *param) : Param(param) {}
1378 void Emit(CodeGenFunction &CGF, Flags flags) {
1379 CGF.EmitARCRelease(Param, /*precise*/ false);
1384 /// Emit an alloca (or GlobalValue depending on target)
1385 /// for the specified parameter and set up LocalDeclMap.
1386 void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg,
1388 // FIXME: Why isn't ImplicitParamDecl a ParmVarDecl?
1389 assert((isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)) &&
1390 "Invalid argument to EmitParmDecl");
1392 Arg->setName(D.getName());
1394 // Use better IR generation for certain implicit parameters.
1395 if (isa<ImplicitParamDecl>(D)) {
1396 // The only implicit argument a block has is its literal.
1398 LocalDeclMap[&D] = Arg;
1400 if (CGDebugInfo *DI = getDebugInfo()) {
1401 DI->setLocation(D.getLocation());
1402 DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, Arg, Builder);
1409 QualType Ty = D.getType();
1411 llvm::Value *DeclPtr;
1412 // If this is an aggregate or variable sized value, reuse the input pointer.
1413 if (!Ty->isConstantSizeType() ||
1414 CodeGenFunction::hasAggregateLLVMType(Ty)) {
1417 // Otherwise, create a temporary to hold the value.
1418 DeclPtr = CreateMemTemp(Ty, D.getName() + ".addr");
1420 bool doStore = true;
1422 Qualifiers qs = Ty.getQualifiers();
1424 if (Qualifiers::ObjCLifetime lt = qs.getObjCLifetime()) {
1425 // We honor __attribute__((ns_consumed)) for types with lifetime.
1426 // For __strong, it's handled by just skipping the initial retain;
1427 // otherwise we have to balance out the initial +1 with an extra
1428 // cleanup to do the release at the end of the function.
1429 bool isConsumed = D.hasAttr<NSConsumedAttr>();
1431 // 'self' is always formally __strong, but if this is not an
1432 // init method then we don't want to retain it.
1433 if (D.isARCPseudoStrong()) {
1434 const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CurCodeDecl);
1435 assert(&D == method->getSelfDecl());
1436 assert(lt == Qualifiers::OCL_Strong);
1437 assert(qs.hasConst());
1438 assert(method->getMethodFamily() != OMF_init);
1440 lt = Qualifiers::OCL_ExplicitNone;
1443 if (lt == Qualifiers::OCL_Strong) {
1445 // Don't use objc_retainBlock for block pointers, because we
1446 // don't want to Block_copy something just because we got it
1448 Arg = EmitARCRetainNonBlock(Arg);
1450 // Push the cleanup for a consumed parameter.
1452 EHStack.pushCleanup<ConsumeARCParameter>(getARCCleanupKind(), Arg);
1454 if (lt == Qualifiers::OCL_Weak) {
1455 EmitARCInitWeak(DeclPtr, Arg);
1456 doStore = false; // The weak init is a store, no need to do two
1460 // Enter the cleanup scope.
1461 EmitAutoVarWithLifetime(*this, D, DeclPtr, lt);
1464 // Store the initial value into the alloca.
1466 LValue lv = MakeAddrLValue(DeclPtr, Ty,
1467 getContext().getDeclAlign(&D).getQuantity());
1468 EmitStoreOfScalar(Arg, lv);
1472 llvm::Value *&DMEntry = LocalDeclMap[&D];
1473 assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
1476 // Emit debug info for param declaration.
1477 if (CGDebugInfo *DI = getDebugInfo())
1478 DI->EmitDeclareOfArgVariable(&D, DeclPtr, ArgNo, Builder);