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 "CGOpenCLRuntime.h"
18 #include "clang/AST/ASTContext.h"
19 #include "clang/AST/CharUnits.h"
20 #include "clang/AST/Decl.h"
21 #include "clang/AST/DeclObjC.h"
22 #include "clang/Basic/SourceManager.h"
23 #include "clang/Basic/TargetInfo.h"
24 #include "clang/Frontend/CodeGenOptions.h"
25 #include "llvm/GlobalVariable.h"
26 #include "llvm/Intrinsics.h"
27 #include "llvm/Target/TargetData.h"
28 #include "llvm/Type.h"
29 using namespace clang;
30 using namespace CodeGen;
33 void CodeGenFunction::EmitDecl(const Decl &D) {
34 switch (D.getKind()) {
35 case Decl::TranslationUnit:
37 case Decl::UnresolvedUsingTypename:
38 case Decl::ClassTemplateSpecialization:
39 case Decl::ClassTemplatePartialSpecialization:
40 case Decl::TemplateTypeParm:
41 case Decl::UnresolvedUsingValue:
42 case Decl::NonTypeTemplateParm:
44 case Decl::CXXConstructor:
45 case Decl::CXXDestructor:
46 case Decl::CXXConversion:
48 case Decl::IndirectField:
50 case Decl::ObjCAtDefsField:
52 case Decl::ImplicitParam:
53 case Decl::ClassTemplate:
54 case Decl::FunctionTemplate:
55 case Decl::TypeAliasTemplate:
56 case Decl::TemplateTemplateParm:
57 case Decl::ObjCMethod:
58 case Decl::ObjCCategory:
59 case Decl::ObjCProtocol:
60 case Decl::ObjCInterface:
61 case Decl::ObjCCategoryImpl:
62 case Decl::ObjCImplementation:
63 case Decl::ObjCProperty:
64 case Decl::ObjCCompatibleAlias:
65 case Decl::AccessSpec:
66 case Decl::LinkageSpec:
67 case Decl::ObjCPropertyImpl:
69 case Decl::ObjCForwardProtocol:
70 case Decl::FileScopeAsm:
72 case Decl::FriendTemplate:
74 case Decl::ClassScopeFunctionSpecialization:
75 llvm_unreachable("Declaration should not be in declstmts!");
76 case Decl::Function: // void X();
77 case Decl::Record: // struct/union/class X;
78 case Decl::Enum: // enum X;
79 case Decl::EnumConstant: // enum ? { X = ? }
80 case Decl::CXXRecord: // struct/union/class X; [C++]
81 case Decl::Using: // using X; [C++]
82 case Decl::UsingShadow:
83 case Decl::UsingDirective: // using namespace X; [C++]
84 case Decl::NamespaceAlias:
85 case Decl::StaticAssert: // static_assert(X, ""); [C++0x]
86 case Decl::Label: // __label__ x;
87 // None of these decls require codegen support.
91 const VarDecl &VD = cast<VarDecl>(D);
92 assert(VD.isLocalVarDecl() &&
93 "Should not see file-scope variables inside a function!");
94 return EmitVarDecl(VD);
97 case Decl::Typedef: // typedef int X;
98 case Decl::TypeAlias: { // using X = int; [C++0x]
99 const TypedefNameDecl &TD = cast<TypedefNameDecl>(D);
100 QualType Ty = TD.getUnderlyingType();
102 if (Ty->isVariablyModifiedType())
103 EmitVariablyModifiedType(Ty);
108 /// EmitVarDecl - This method handles emission of any variable declaration
109 /// inside a function, including static vars etc.
110 void CodeGenFunction::EmitVarDecl(const VarDecl &D) {
111 switch (D.getStorageClass()) {
115 return EmitAutoVarDecl(D);
117 llvm::GlobalValue::LinkageTypes Linkage =
118 llvm::GlobalValue::InternalLinkage;
120 // If the function definition has some sort of weak linkage, its
121 // static variables should also be weak so that they get properly
122 // uniqued. We can't do this in C, though, because there's no
123 // standard way to agree on which variables are the same (i.e.
124 // there's no mangling).
125 if (getContext().getLangOptions().CPlusPlus)
126 if (llvm::GlobalValue::isWeakForLinker(CurFn->getLinkage()))
127 Linkage = CurFn->getLinkage();
129 return EmitStaticVarDecl(D, Linkage);
132 case SC_PrivateExtern:
133 // Don't emit it now, allow it to be emitted lazily on its first use.
135 case SC_OpenCLWorkGroupLocal:
136 return CGM.getOpenCLRuntime().EmitWorkGroupLocalVarDecl(*this, D);
139 llvm_unreachable("Unknown storage class");
142 static std::string GetStaticDeclName(CodeGenFunction &CGF, const VarDecl &D,
143 const char *Separator) {
144 CodeGenModule &CGM = CGF.CGM;
145 if (CGF.getContext().getLangOptions().CPlusPlus) {
146 StringRef Name = CGM.getMangledName(&D);
150 std::string ContextName;
151 if (!CGF.CurFuncDecl) {
152 // Better be in a block declared in global scope.
153 const NamedDecl *ND = cast<NamedDecl>(&D);
154 const DeclContext *DC = ND->getDeclContext();
155 if (const BlockDecl *BD = dyn_cast<BlockDecl>(DC)) {
157 CGM.getBlockMangledName(GlobalDecl(), Name, BD);
158 ContextName = Name.getString();
161 llvm_unreachable("Unknown context for block static var decl");
162 } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CGF.CurFuncDecl)) {
163 StringRef Name = CGM.getMangledName(FD);
164 ContextName = Name.str();
165 } else if (isa<ObjCMethodDecl>(CGF.CurFuncDecl))
166 ContextName = CGF.CurFn->getName();
168 llvm_unreachable("Unknown context for static var decl");
170 return ContextName + Separator + D.getNameAsString();
173 llvm::GlobalVariable *
174 CodeGenFunction::CreateStaticVarDecl(const VarDecl &D,
175 const char *Separator,
176 llvm::GlobalValue::LinkageTypes Linkage) {
177 QualType Ty = D.getType();
178 assert(Ty->isConstantSizeType() && "VLAs can't be static");
180 std::string Name = GetStaticDeclName(*this, D, Separator);
182 llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(Ty);
183 llvm::GlobalVariable *GV =
184 new llvm::GlobalVariable(CGM.getModule(), LTy,
185 Ty.isConstant(getContext()), Linkage,
186 CGM.EmitNullConstant(D.getType()), Name, 0,
187 D.isThreadSpecified(),
188 CGM.getContext().getTargetAddressSpace(Ty));
189 GV->setAlignment(getContext().getDeclAlign(&D).getQuantity());
190 if (Linkage != llvm::GlobalValue::InternalLinkage)
191 GV->setVisibility(CurFn->getVisibility());
195 /// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
196 /// global variable that has already been created for it. If the initializer
197 /// has a different type than GV does, this may free GV and return a different
198 /// one. Otherwise it just returns GV.
199 llvm::GlobalVariable *
200 CodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D,
201 llvm::GlobalVariable *GV) {
202 llvm::Constant *Init = CGM.EmitConstantExpr(D.getInit(), D.getType(), this);
204 // If constant emission failed, then this should be a C++ static
207 if (!getContext().getLangOptions().CPlusPlus)
208 CGM.ErrorUnsupported(D.getInit(), "constant l-value expression");
209 else if (Builder.GetInsertBlock()) {
210 // Since we have a static initializer, this global variable can't
212 GV->setConstant(false);
214 EmitCXXGuardedInit(D, GV);
219 // The initializer may differ in type from the global. Rewrite
220 // the global to match the initializer. (We have to do this
221 // because some types, like unions, can't be completely represented
222 // in the LLVM type system.)
223 if (GV->getType()->getElementType() != Init->getType()) {
224 llvm::GlobalVariable *OldGV = GV;
226 GV = new llvm::GlobalVariable(CGM.getModule(), Init->getType(),
228 OldGV->getLinkage(), Init, "",
229 /*InsertBefore*/ OldGV,
230 D.isThreadSpecified(),
231 CGM.getContext().getTargetAddressSpace(D.getType()));
232 GV->setVisibility(OldGV->getVisibility());
234 // Steal the name of the old global
237 // Replace all uses of the old global with the new global
238 llvm::Constant *NewPtrForOldDecl =
239 llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
240 OldGV->replaceAllUsesWith(NewPtrForOldDecl);
242 // Erase the old global, since it is no longer used.
243 OldGV->eraseFromParent();
246 GV->setInitializer(Init);
250 void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
251 llvm::GlobalValue::LinkageTypes Linkage) {
252 llvm::Value *&DMEntry = LocalDeclMap[&D];
253 assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
255 llvm::GlobalVariable *GV = CreateStaticVarDecl(D, ".", Linkage);
257 // Store into LocalDeclMap before generating initializer to handle
258 // circular references.
261 // We can't have a VLA here, but we can have a pointer to a VLA,
262 // even though that doesn't really make any sense.
263 // Make sure to evaluate VLA bounds now so that we have them for later.
264 if (D.getType()->isVariablyModifiedType())
265 EmitVariablyModifiedType(D.getType());
267 // Local static block variables must be treated as globals as they may be
268 // referenced in their RHS initializer block-literal expresion.
269 CGM.setStaticLocalDeclAddress(&D, GV);
271 // If this value has an initializer, emit it.
273 GV = AddInitializerToStaticVarDecl(D, GV);
275 GV->setAlignment(getContext().getDeclAlign(&D).getQuantity());
277 if (D.hasAttr<AnnotateAttr>())
278 CGM.AddGlobalAnnotations(&D, GV);
280 if (const SectionAttr *SA = D.getAttr<SectionAttr>())
281 GV->setSection(SA->getName());
283 if (D.hasAttr<UsedAttr>())
284 CGM.AddUsedGlobal(GV);
286 // We may have to cast the constant because of the initializer
289 // FIXME: It is really dangerous to store this in the map; if anyone
290 // RAUW's the GV uses of this constant will be invalid.
291 llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(D.getType());
293 LTy->getPointerTo(CGM.getContext().getTargetAddressSpace(D.getType()));
294 DMEntry = llvm::ConstantExpr::getBitCast(GV, LPtrTy);
296 // Emit global variable debug descriptor for static vars.
297 CGDebugInfo *DI = getDebugInfo();
299 DI->setLocation(D.getLocation());
300 DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(GV), &D);
305 struct DestroyObject : EHScopeStack::Cleanup {
306 DestroyObject(llvm::Value *addr, QualType type,
307 CodeGenFunction::Destroyer *destroyer,
308 bool useEHCleanupForArray)
309 : addr(addr), type(type), destroyer(*destroyer),
310 useEHCleanupForArray(useEHCleanupForArray) {}
314 CodeGenFunction::Destroyer &destroyer;
315 bool useEHCleanupForArray;
317 void Emit(CodeGenFunction &CGF, Flags flags) {
318 // Don't use an EH cleanup recursively from an EH cleanup.
319 bool useEHCleanupForArray =
320 flags.isForNormalCleanup() && this->useEHCleanupForArray;
322 CGF.emitDestroy(addr, type, destroyer, useEHCleanupForArray);
326 struct DestroyNRVOVariable : EHScopeStack::Cleanup {
327 DestroyNRVOVariable(llvm::Value *addr,
328 const CXXDestructorDecl *Dtor,
329 llvm::Value *NRVOFlag)
330 : Dtor(Dtor), NRVOFlag(NRVOFlag), Loc(addr) {}
332 const CXXDestructorDecl *Dtor;
333 llvm::Value *NRVOFlag;
336 void Emit(CodeGenFunction &CGF, Flags flags) {
337 // Along the exceptions path we always execute the dtor.
338 bool NRVO = flags.isForNormalCleanup() && NRVOFlag;
340 llvm::BasicBlock *SkipDtorBB = 0;
342 // If we exited via NRVO, we skip the destructor call.
343 llvm::BasicBlock *RunDtorBB = CGF.createBasicBlock("nrvo.unused");
344 SkipDtorBB = CGF.createBasicBlock("nrvo.skipdtor");
345 llvm::Value *DidNRVO = CGF.Builder.CreateLoad(NRVOFlag, "nrvo.val");
346 CGF.Builder.CreateCondBr(DidNRVO, SkipDtorBB, RunDtorBB);
347 CGF.EmitBlock(RunDtorBB);
350 CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete,
351 /*ForVirtualBase=*/false, Loc);
353 if (NRVO) CGF.EmitBlock(SkipDtorBB);
357 struct CallStackRestore : EHScopeStack::Cleanup {
359 CallStackRestore(llvm::Value *Stack) : Stack(Stack) {}
360 void Emit(CodeGenFunction &CGF, Flags flags) {
361 llvm::Value *V = CGF.Builder.CreateLoad(Stack);
362 llvm::Value *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stackrestore);
363 CGF.Builder.CreateCall(F, V);
367 struct ExtendGCLifetime : EHScopeStack::Cleanup {
369 ExtendGCLifetime(const VarDecl *var) : Var(*var) {}
371 void Emit(CodeGenFunction &CGF, Flags flags) {
372 // Compute the address of the local variable, in case it's a
373 // byref or something.
374 DeclRefExpr DRE(const_cast<VarDecl*>(&Var), Var.getType(), VK_LValue,
376 llvm::Value *value = CGF.EmitLoadOfScalar(CGF.EmitDeclRefLValue(&DRE));
377 CGF.EmitExtendGCLifetime(value);
381 struct CallCleanupFunction : EHScopeStack::Cleanup {
382 llvm::Constant *CleanupFn;
383 const CGFunctionInfo &FnInfo;
386 CallCleanupFunction(llvm::Constant *CleanupFn, const CGFunctionInfo *Info,
388 : CleanupFn(CleanupFn), FnInfo(*Info), Var(*Var) {}
390 void Emit(CodeGenFunction &CGF, Flags flags) {
391 DeclRefExpr DRE(const_cast<VarDecl*>(&Var), Var.getType(), VK_LValue,
393 // Compute the address of the local variable, in case it's a byref
395 llvm::Value *Addr = CGF.EmitDeclRefLValue(&DRE).getAddress();
397 // In some cases, the type of the function argument will be different from
398 // the type of the pointer. An example of this is
399 // void f(void* arg);
400 // __attribute__((cleanup(f))) void *g;
402 // To fix this we insert a bitcast here.
403 QualType ArgTy = FnInfo.arg_begin()->type;
405 CGF.Builder.CreateBitCast(Addr, CGF.ConvertType(ArgTy));
408 Args.add(RValue::get(Arg),
409 CGF.getContext().getPointerType(Var.getType()));
410 CGF.EmitCall(FnInfo, CleanupFn, ReturnValueSlot(), Args);
415 /// EmitAutoVarWithLifetime - Does the setup required for an automatic
416 /// variable with lifetime.
417 static void EmitAutoVarWithLifetime(CodeGenFunction &CGF, const VarDecl &var,
419 Qualifiers::ObjCLifetime lifetime) {
421 case Qualifiers::OCL_None:
422 llvm_unreachable("present but none");
424 case Qualifiers::OCL_ExplicitNone:
428 case Qualifiers::OCL_Strong: {
429 CodeGenFunction::Destroyer &destroyer =
430 (var.hasAttr<ObjCPreciseLifetimeAttr>()
431 ? CodeGenFunction::destroyARCStrongPrecise
432 : CodeGenFunction::destroyARCStrongImprecise);
434 CleanupKind cleanupKind = CGF.getARCCleanupKind();
435 CGF.pushDestroy(cleanupKind, addr, var.getType(), destroyer,
436 cleanupKind & EHCleanup);
439 case Qualifiers::OCL_Autoreleasing:
443 case Qualifiers::OCL_Weak:
444 // __weak objects always get EH cleanups; otherwise, exceptions
445 // could cause really nasty crashes instead of mere leaks.
446 CGF.pushDestroy(NormalAndEHCleanup, addr, var.getType(),
447 CodeGenFunction::destroyARCWeak,
448 /*useEHCleanup*/ true);
453 static bool isAccessedBy(const VarDecl &var, const Stmt *s) {
454 if (const Expr *e = dyn_cast<Expr>(s)) {
455 // Skip the most common kinds of expressions that make
456 // hierarchy-walking expensive.
457 s = e = e->IgnoreParenCasts();
459 if (const DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e))
460 return (ref->getDecl() == &var);
463 for (Stmt::const_child_range children = s->children(); children; ++children)
464 // children might be null; as in missing decl or conditional of an if-stmt.
465 if ((*children) && isAccessedBy(var, *children))
471 static bool isAccessedBy(const ValueDecl *decl, const Expr *e) {
472 if (!decl) return false;
473 if (!isa<VarDecl>(decl)) return false;
474 const VarDecl *var = cast<VarDecl>(decl);
475 return isAccessedBy(*var, e);
478 static void drillIntoBlockVariable(CodeGenFunction &CGF,
480 const VarDecl *var) {
481 lvalue.setAddress(CGF.BuildBlockByrefAddress(lvalue.getAddress(), var));
484 void CodeGenFunction::EmitScalarInit(const Expr *init,
487 bool capturedByInit) {
488 Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
490 llvm::Value *value = EmitScalarExpr(init);
492 drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
493 EmitStoreThroughLValue(RValue::get(value), lvalue);
497 // If we're emitting a value with lifetime, we have to do the
498 // initialization *before* we leave the cleanup scopes.
499 CodeGenFunction::RunCleanupsScope Scope(*this);
500 if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(init))
501 init = ewc->getSubExpr();
503 // We have to maintain the illusion that the variable is
504 // zero-initialized. If the variable might be accessed in its
505 // initializer, zero-initialize before running the initializer, then
506 // actually perform the initialization with an assign.
507 bool accessedByInit = false;
508 if (lifetime != Qualifiers::OCL_ExplicitNone)
509 accessedByInit = (capturedByInit || isAccessedBy(D, init));
510 if (accessedByInit) {
511 LValue tempLV = lvalue;
512 // Drill down to the __block object if necessary.
513 if (capturedByInit) {
514 // We can use a simple GEP for this because it can't have been
516 tempLV.setAddress(Builder.CreateStructGEP(tempLV.getAddress(),
517 getByRefValueLLVMField(cast<VarDecl>(D))));
520 llvm::PointerType *ty
521 = cast<llvm::PointerType>(tempLV.getAddress()->getType());
522 ty = cast<llvm::PointerType>(ty->getElementType());
524 llvm::Value *zero = llvm::ConstantPointerNull::get(ty);
526 // If __weak, we want to use a barrier under certain conditions.
527 if (lifetime == Qualifiers::OCL_Weak)
528 EmitARCInitWeak(tempLV.getAddress(), zero);
530 // Otherwise just do a simple store.
532 EmitStoreOfScalar(zero, tempLV);
535 // Emit the initializer.
536 llvm::Value *value = 0;
539 case Qualifiers::OCL_None:
540 llvm_unreachable("present but none");
542 case Qualifiers::OCL_ExplicitNone:
544 value = EmitScalarExpr(init);
547 case Qualifiers::OCL_Strong: {
548 value = EmitARCRetainScalarExpr(init);
552 case Qualifiers::OCL_Weak: {
553 // No way to optimize a producing initializer into this. It's not
554 // worth optimizing for, because the value will immediately
555 // disappear in the common case.
556 value = EmitScalarExpr(init);
558 if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
560 EmitARCStoreWeak(lvalue.getAddress(), value, /*ignored*/ true);
562 EmitARCInitWeak(lvalue.getAddress(), value);
566 case Qualifiers::OCL_Autoreleasing:
567 value = EmitARCRetainAutoreleaseScalarExpr(init);
571 if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
573 // If the variable might have been accessed by its initializer, we
574 // might have to initialize with a barrier. We have to do this for
575 // both __weak and __strong, but __weak got filtered out above.
576 if (accessedByInit && lifetime == Qualifiers::OCL_Strong) {
577 llvm::Value *oldValue = EmitLoadOfScalar(lvalue);
578 EmitStoreOfScalar(value, lvalue);
579 EmitARCRelease(oldValue, /*precise*/ false);
583 EmitStoreOfScalar(value, lvalue);
586 /// EmitScalarInit - Initialize the given lvalue with the given object.
587 void CodeGenFunction::EmitScalarInit(llvm::Value *init, LValue lvalue) {
588 Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
590 return EmitStoreThroughLValue(RValue::get(init), lvalue);
593 case Qualifiers::OCL_None:
594 llvm_unreachable("present but none");
596 case Qualifiers::OCL_ExplicitNone:
600 case Qualifiers::OCL_Strong:
601 init = EmitARCRetain(lvalue.getType(), init);
604 case Qualifiers::OCL_Weak:
605 // Initialize and then skip the primitive store.
606 EmitARCInitWeak(lvalue.getAddress(), init);
609 case Qualifiers::OCL_Autoreleasing:
610 init = EmitARCRetainAutorelease(lvalue.getType(), init);
614 EmitStoreOfScalar(init, lvalue);
617 /// canEmitInitWithFewStoresAfterMemset - Decide whether we can emit the
618 /// non-zero parts of the specified initializer with equal or fewer than
619 /// NumStores scalar stores.
620 static bool canEmitInitWithFewStoresAfterMemset(llvm::Constant *Init,
621 unsigned &NumStores) {
622 // Zero and Undef never requires any extra stores.
623 if (isa<llvm::ConstantAggregateZero>(Init) ||
624 isa<llvm::ConstantPointerNull>(Init) ||
625 isa<llvm::UndefValue>(Init))
627 if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) ||
628 isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) ||
629 isa<llvm::ConstantExpr>(Init))
630 return Init->isNullValue() || NumStores--;
632 // See if we can emit each element.
633 if (isa<llvm::ConstantArray>(Init) || isa<llvm::ConstantStruct>(Init)) {
634 for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
635 llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i));
636 if (!canEmitInitWithFewStoresAfterMemset(Elt, NumStores))
642 // Anything else is hard and scary.
646 /// emitStoresForInitAfterMemset - For inits that
647 /// canEmitInitWithFewStoresAfterMemset returned true for, emit the scalar
648 /// stores that would be required.
649 static void emitStoresForInitAfterMemset(llvm::Constant *Init, llvm::Value *Loc,
650 bool isVolatile, CGBuilderTy &Builder) {
651 // Zero doesn't require any stores.
652 if (isa<llvm::ConstantAggregateZero>(Init) ||
653 isa<llvm::ConstantPointerNull>(Init) ||
654 isa<llvm::UndefValue>(Init))
657 if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) ||
658 isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) ||
659 isa<llvm::ConstantExpr>(Init)) {
660 if (!Init->isNullValue())
661 Builder.CreateStore(Init, Loc, isVolatile);
665 assert((isa<llvm::ConstantStruct>(Init) || isa<llvm::ConstantArray>(Init)) &&
666 "Unknown value type!");
668 for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
669 llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i));
670 if (Elt->isNullValue()) continue;
672 // Otherwise, get a pointer to the element and emit it.
673 emitStoresForInitAfterMemset(Elt, Builder.CreateConstGEP2_32(Loc, 0, i),
674 isVolatile, Builder);
679 /// shouldUseMemSetPlusStoresToInitialize - Decide whether we should use memset
680 /// plus some stores to initialize a local variable instead of using a memcpy
681 /// from a constant global. It is beneficial to use memset if the global is all
682 /// zeros, or mostly zeros and large.
683 static bool shouldUseMemSetPlusStoresToInitialize(llvm::Constant *Init,
684 uint64_t GlobalSize) {
685 // If a global is all zeros, always use a memset.
686 if (isa<llvm::ConstantAggregateZero>(Init)) return true;
689 // If a non-zero global is <= 32 bytes, always use a memcpy. If it is large,
690 // do it if it will require 6 or fewer scalar stores.
691 // TODO: Should budget depends on the size? Avoiding a large global warrants
692 // plopping in more stores.
693 unsigned StoreBudget = 6;
694 uint64_t SizeLimit = 32;
696 return GlobalSize > SizeLimit &&
697 canEmitInitWithFewStoresAfterMemset(Init, StoreBudget);
701 /// EmitAutoVarDecl - Emit code and set up an entry in LocalDeclMap for a
702 /// variable declaration with auto, register, or no storage class specifier.
703 /// These turn into simple stack objects, or GlobalValues depending on target.
704 void CodeGenFunction::EmitAutoVarDecl(const VarDecl &D) {
705 AutoVarEmission emission = EmitAutoVarAlloca(D);
706 EmitAutoVarInit(emission);
707 EmitAutoVarCleanups(emission);
710 /// EmitAutoVarAlloca - Emit the alloca and debug information for a
711 /// local variable. Does not emit initalization or destruction.
712 CodeGenFunction::AutoVarEmission
713 CodeGenFunction::EmitAutoVarAlloca(const VarDecl &D) {
714 QualType Ty = D.getType();
716 AutoVarEmission emission(D);
718 bool isByRef = D.hasAttr<BlocksAttr>();
719 emission.IsByRef = isByRef;
721 CharUnits alignment = getContext().getDeclAlign(&D);
722 emission.Alignment = alignment;
724 // If the type is variably-modified, emit all the VLA sizes for it.
725 if (Ty->isVariablyModifiedType())
726 EmitVariablyModifiedType(Ty);
728 llvm::Value *DeclPtr;
729 if (Ty->isConstantSizeType()) {
730 if (!Target.useGlobalsForAutomaticVariables()) {
731 bool NRVO = getContext().getLangOptions().ElideConstructors &&
734 // If this value is a POD array or struct with a statically
735 // determinable constant initializer, there are optimizations we
737 // TODO: we can potentially constant-evaluate non-POD structs and
738 // arrays as long as the initialization is trivial (e.g. if they
739 // have a non-trivial destructor, but not a non-trivial constructor).
741 (Ty->isArrayType() || Ty->isRecordType()) &&
742 (Ty.isPODType(getContext()) ||
743 getContext().getBaseElementType(Ty)->isObjCObjectPointerType()) &&
744 D.getInit()->isConstantInitializer(getContext(), false)) {
746 // If the variable's a const type, and it's neither an NRVO
747 // candidate nor a __block variable, emit it as a global instead.
748 if (CGM.getCodeGenOpts().MergeAllConstants && Ty.isConstQualified() &&
750 EmitStaticVarDecl(D, llvm::GlobalValue::InternalLinkage);
752 emission.Address = 0; // signal this condition to later callbacks
753 assert(emission.wasEmittedAsGlobal());
757 // Otherwise, tell the initialization code that we're in this case.
758 emission.IsConstantAggregate = true;
761 // A normal fixed sized variable becomes an alloca in the entry block,
762 // unless it's an NRVO variable.
763 llvm::Type *LTy = ConvertTypeForMem(Ty);
766 // The named return value optimization: allocate this variable in the
767 // return slot, so that we can elide the copy when returning this
768 // variable (C++0x [class.copy]p34).
769 DeclPtr = ReturnValue;
771 if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
772 if (!cast<CXXRecordDecl>(RecordTy->getDecl())->hasTrivialDestructor()) {
773 // Create a flag that is used to indicate when the NRVO was applied
774 // to this variable. Set it to zero to indicate that NRVO was not
776 llvm::Value *Zero = Builder.getFalse();
777 llvm::Value *NRVOFlag = CreateTempAlloca(Zero->getType(), "nrvo");
779 Builder.CreateStore(Zero, NRVOFlag);
781 // Record the NRVO flag for this variable.
782 NRVOFlags[&D] = NRVOFlag;
783 emission.NRVOFlag = NRVOFlag;
788 LTy = BuildByRefType(&D);
790 llvm::AllocaInst *Alloc = CreateTempAlloca(LTy);
791 Alloc->setName(D.getNameAsString());
793 CharUnits allocaAlignment = alignment;
795 allocaAlignment = std::max(allocaAlignment,
796 getContext().toCharUnitsFromBits(Target.getPointerAlign(0)));
797 Alloc->setAlignment(allocaAlignment.getQuantity());
801 // Targets that don't support recursion emit locals as globals.
803 D.getStorageClass() == SC_Register ? ".reg." : ".auto.";
804 DeclPtr = CreateStaticVarDecl(D, Class,
805 llvm::GlobalValue::InternalLinkage);
810 if (!DidCallStackSave) {
812 llvm::Value *Stack = CreateTempAlloca(Int8PtrTy, "saved_stack");
814 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stacksave);
815 llvm::Value *V = Builder.CreateCall(F);
817 Builder.CreateStore(V, Stack);
819 DidCallStackSave = true;
821 // Push a cleanup block and restore the stack there.
822 // FIXME: in general circumstances, this should be an EH cleanup.
823 EHStack.pushCleanup<CallStackRestore>(NormalCleanup, Stack);
826 llvm::Value *elementCount;
827 QualType elementType;
828 llvm::tie(elementCount, elementType) = getVLASize(Ty);
830 llvm::Type *llvmTy = ConvertTypeForMem(elementType);
832 // Allocate memory for the array.
833 llvm::AllocaInst *vla = Builder.CreateAlloca(llvmTy, elementCount, "vla");
834 vla->setAlignment(alignment.getQuantity());
839 llvm::Value *&DMEntry = LocalDeclMap[&D];
840 assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
842 emission.Address = DeclPtr;
844 // Emit debug info for local var declaration.
845 if (HaveInsertPoint())
846 if (CGDebugInfo *DI = getDebugInfo()) {
847 DI->setLocation(D.getLocation());
848 if (Target.useGlobalsForAutomaticVariables()) {
849 DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(DeclPtr), &D);
851 DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder);
854 if (D.hasAttr<AnnotateAttr>())
855 EmitVarAnnotations(&D, emission.Address);
860 /// Determines whether the given __block variable is potentially
861 /// captured by the given expression.
862 static bool isCapturedBy(const VarDecl &var, const Expr *e) {
863 // Skip the most common kinds of expressions that make
864 // hierarchy-walking expensive.
865 e = e->IgnoreParenCasts();
867 if (const BlockExpr *be = dyn_cast<BlockExpr>(e)) {
868 const BlockDecl *block = be->getBlockDecl();
869 for (BlockDecl::capture_const_iterator i = block->capture_begin(),
870 e = block->capture_end(); i != e; ++i) {
871 if (i->getVariable() == &var)
875 // No need to walk into the subexpressions.
879 if (const StmtExpr *SE = dyn_cast<StmtExpr>(e)) {
880 const CompoundStmt *CS = SE->getSubStmt();
881 for (CompoundStmt::const_body_iterator BI = CS->body_begin(),
882 BE = CS->body_end(); BI != BE; ++BI)
883 if (Expr *E = dyn_cast<Expr>((*BI))) {
884 if (isCapturedBy(var, E))
887 else if (DeclStmt *DS = dyn_cast<DeclStmt>((*BI))) {
888 // special case declarations
889 for (DeclStmt::decl_iterator I = DS->decl_begin(), E = DS->decl_end();
891 if (VarDecl *VD = dyn_cast<VarDecl>((*I))) {
892 Expr *Init = VD->getInit();
893 if (Init && isCapturedBy(var, Init))
899 // FIXME. Make safe assumption assuming arbitrary statements cause capturing.
900 // Later, provide code to poke into statements for capture analysis.
905 for (Stmt::const_child_range children = e->children(); children; ++children)
906 if (isCapturedBy(var, cast<Expr>(*children)))
912 /// \brief Determine whether the given initializer is trivial in the sense
913 /// that it requires no code to be generated.
914 static bool isTrivialInitializer(const Expr *Init) {
918 if (const CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init))
919 if (CXXConstructorDecl *Constructor = Construct->getConstructor())
920 if (Constructor->isTrivial() &&
921 Constructor->isDefaultConstructor() &&
922 !Construct->requiresZeroInitialization())
927 void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) {
928 assert(emission.Variable && "emission was not valid!");
930 // If this was emitted as a global constant, we're done.
931 if (emission.wasEmittedAsGlobal()) return;
933 const VarDecl &D = *emission.Variable;
934 QualType type = D.getType();
936 // If this local has an initializer, emit it now.
937 const Expr *Init = D.getInit();
939 // If we are at an unreachable point, we don't need to emit the initializer
940 // unless it contains a label.
941 if (!HaveInsertPoint()) {
942 if (!Init || !ContainsLabel(Init)) return;
946 // Initialize the structure of a __block variable.
947 if (emission.IsByRef)
948 emitByrefStructureInit(emission);
950 if (isTrivialInitializer(Init))
953 CharUnits alignment = emission.Alignment;
955 // Check whether this is a byref variable that's potentially
956 // captured and moved by its own initializer. If so, we'll need to
957 // emit the initializer first, then copy into the variable.
958 bool capturedByInit = emission.IsByRef && isCapturedBy(D, Init);
961 capturedByInit ? emission.Address : emission.getObjectAddress(*this);
963 if (!emission.IsConstantAggregate) {
964 LValue lv = MakeAddrLValue(Loc, type, alignment.getQuantity());
966 return EmitExprAsInit(Init, &D, lv, capturedByInit);
969 // If this is a simple aggregate initialization, we can optimize it
971 assert(!capturedByInit && "constant init contains a capturing block?");
973 bool isVolatile = type.isVolatileQualified();
975 llvm::Constant *constant = CGM.EmitConstantExpr(D.getInit(), type, this);
976 assert(constant != 0 && "Wasn't a simple constant init?");
978 llvm::Value *SizeVal =
979 llvm::ConstantInt::get(IntPtrTy,
980 getContext().getTypeSizeInChars(type).getQuantity());
982 llvm::Type *BP = Int8PtrTy;
983 if (Loc->getType() != BP)
984 Loc = Builder.CreateBitCast(Loc, BP);
986 // If the initializer is all or mostly zeros, codegen with memset then do
987 // a few stores afterward.
988 if (shouldUseMemSetPlusStoresToInitialize(constant,
989 CGM.getTargetData().getTypeAllocSize(constant->getType()))) {
990 Builder.CreateMemSet(Loc, llvm::ConstantInt::get(Int8Ty, 0), SizeVal,
991 alignment.getQuantity(), isVolatile);
992 if (!constant->isNullValue()) {
993 Loc = Builder.CreateBitCast(Loc, constant->getType()->getPointerTo());
994 emitStoresForInitAfterMemset(constant, Loc, isVolatile, Builder);
997 // Otherwise, create a temporary global with the initializer then
998 // memcpy from the global to the alloca.
999 std::string Name = GetStaticDeclName(*this, D, ".");
1000 llvm::GlobalVariable *GV =
1001 new llvm::GlobalVariable(CGM.getModule(), constant->getType(), true,
1002 llvm::GlobalValue::PrivateLinkage,
1003 constant, Name, 0, false, 0);
1004 GV->setAlignment(alignment.getQuantity());
1005 GV->setUnnamedAddr(true);
1007 llvm::Value *SrcPtr = GV;
1008 if (SrcPtr->getType() != BP)
1009 SrcPtr = Builder.CreateBitCast(SrcPtr, BP);
1011 Builder.CreateMemCpy(Loc, SrcPtr, SizeVal, alignment.getQuantity(),
1016 /// Emit an expression as an initializer for a variable at the given
1017 /// location. The expression is not necessarily the normal
1018 /// initializer for the variable, and the address is not necessarily
1019 /// its normal location.
1021 /// \param init the initializing expression
1022 /// \param var the variable to act as if we're initializing
1023 /// \param loc the address to initialize; its type is a pointer
1024 /// to the LLVM mapping of the variable's type
1025 /// \param alignment the alignment of the address
1026 /// \param capturedByInit true if the variable is a __block variable
1027 /// whose address is potentially changed by the initializer
1028 void CodeGenFunction::EmitExprAsInit(const Expr *init,
1031 bool capturedByInit) {
1032 QualType type = D->getType();
1034 if (type->isReferenceType()) {
1035 RValue rvalue = EmitReferenceBindingToExpr(init, D);
1037 drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
1038 EmitStoreThroughLValue(rvalue, lvalue);
1039 } else if (!hasAggregateLLVMType(type)) {
1040 EmitScalarInit(init, D, lvalue, capturedByInit);
1041 } else if (type->isAnyComplexType()) {
1042 ComplexPairTy complex = EmitComplexExpr(init);
1044 drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
1045 StoreComplexToAddr(complex, lvalue.getAddress(), lvalue.isVolatile());
1047 // TODO: how can we delay here if D is captured by its initializer?
1048 EmitAggExpr(init, AggValueSlot::forLValue(lvalue,
1049 AggValueSlot::IsDestructed,
1050 AggValueSlot::DoesNotNeedGCBarriers,
1051 AggValueSlot::IsNotAliased));
1055 /// Enter a destroy cleanup for the given local variable.
1056 void CodeGenFunction::emitAutoVarTypeCleanup(
1057 const CodeGenFunction::AutoVarEmission &emission,
1058 QualType::DestructionKind dtorKind) {
1059 assert(dtorKind != QualType::DK_none);
1061 // Note that for __block variables, we want to destroy the
1062 // original stack object, not the possibly forwarded object.
1063 llvm::Value *addr = emission.getObjectAddress(*this);
1065 const VarDecl *var = emission.Variable;
1066 QualType type = var->getType();
1068 CleanupKind cleanupKind = NormalAndEHCleanup;
1069 CodeGenFunction::Destroyer *destroyer = 0;
1072 case QualType::DK_none:
1073 llvm_unreachable("no cleanup for trivially-destructible variable");
1075 case QualType::DK_cxx_destructor:
1076 // If there's an NRVO flag on the emission, we need a different
1078 if (emission.NRVOFlag) {
1079 assert(!type->isArrayType());
1080 CXXDestructorDecl *dtor = type->getAsCXXRecordDecl()->getDestructor();
1081 EHStack.pushCleanup<DestroyNRVOVariable>(cleanupKind, addr, dtor,
1087 case QualType::DK_objc_strong_lifetime:
1088 // Suppress cleanups for pseudo-strong variables.
1089 if (var->isARCPseudoStrong()) return;
1091 // Otherwise, consider whether to use an EH cleanup or not.
1092 cleanupKind = getARCCleanupKind();
1094 // Use the imprecise destroyer by default.
1095 if (!var->hasAttr<ObjCPreciseLifetimeAttr>())
1096 destroyer = CodeGenFunction::destroyARCStrongImprecise;
1099 case QualType::DK_objc_weak_lifetime:
1103 // If we haven't chosen a more specific destroyer, use the default.
1104 if (!destroyer) destroyer = &getDestroyer(dtorKind);
1106 // Use an EH cleanup in array destructors iff the destructor itself
1107 // is being pushed as an EH cleanup.
1108 bool useEHCleanup = (cleanupKind & EHCleanup);
1109 EHStack.pushCleanup<DestroyObject>(cleanupKind, addr, type, destroyer,
1113 void CodeGenFunction::EmitAutoVarCleanups(const AutoVarEmission &emission) {
1114 assert(emission.Variable && "emission was not valid!");
1116 // If this was emitted as a global constant, we're done.
1117 if (emission.wasEmittedAsGlobal()) return;
1119 const VarDecl &D = *emission.Variable;
1121 // Check the type for a cleanup.
1122 if (QualType::DestructionKind dtorKind = D.getType().isDestructedType())
1123 emitAutoVarTypeCleanup(emission, dtorKind);
1125 // In GC mode, honor objc_precise_lifetime.
1126 if (getLangOptions().getGC() != LangOptions::NonGC &&
1127 D.hasAttr<ObjCPreciseLifetimeAttr>()) {
1128 EHStack.pushCleanup<ExtendGCLifetime>(NormalCleanup, &D);
1131 // Handle the cleanup attribute.
1132 if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) {
1133 const FunctionDecl *FD = CA->getFunctionDecl();
1135 llvm::Constant *F = CGM.GetAddrOfFunction(FD);
1136 assert(F && "Could not find function!");
1138 const CGFunctionInfo &Info = CGM.getTypes().getFunctionInfo(FD);
1139 EHStack.pushCleanup<CallCleanupFunction>(NormalAndEHCleanup, F, &Info, &D);
1142 // If this is a block variable, call _Block_object_destroy
1143 // (on the unforwarded address).
1144 if (emission.IsByRef)
1145 enterByrefCleanup(emission);
1148 CodeGenFunction::Destroyer &
1149 CodeGenFunction::getDestroyer(QualType::DestructionKind kind) {
1150 // This is surprisingly compiler-dependent. GCC 4.2 can't bind
1151 // references to functions directly in returns, and using '*&foo'
1152 // confuses MSVC. Luckily, the following code pattern works in both.
1153 Destroyer *destroyer = 0;
1155 case QualType::DK_none: llvm_unreachable("no destroyer for trivial dtor");
1156 case QualType::DK_cxx_destructor:
1157 destroyer = &destroyCXXObject;
1159 case QualType::DK_objc_strong_lifetime:
1160 destroyer = &destroyARCStrongPrecise;
1162 case QualType::DK_objc_weak_lifetime:
1163 destroyer = &destroyARCWeak;
1169 /// pushDestroy - Push the standard destructor for the given type.
1170 void CodeGenFunction::pushDestroy(QualType::DestructionKind dtorKind,
1171 llvm::Value *addr, QualType type) {
1172 assert(dtorKind && "cannot push destructor for trivial type");
1174 CleanupKind cleanupKind = getCleanupKind(dtorKind);
1175 pushDestroy(cleanupKind, addr, type, getDestroyer(dtorKind),
1176 cleanupKind & EHCleanup);
1179 void CodeGenFunction::pushDestroy(CleanupKind cleanupKind, llvm::Value *addr,
1180 QualType type, Destroyer &destroyer,
1181 bool useEHCleanupForArray) {
1182 pushFullExprCleanup<DestroyObject>(cleanupKind, addr, type,
1183 destroyer, useEHCleanupForArray);
1186 /// emitDestroy - Immediately perform the destruction of the given
1189 /// \param addr - the address of the object; a type*
1190 /// \param type - the type of the object; if an array type, all
1191 /// objects are destroyed in reverse order
1192 /// \param destroyer - the function to call to destroy individual
1194 /// \param useEHCleanupForArray - whether an EH cleanup should be
1195 /// used when destroying array elements, in case one of the
1196 /// destructions throws an exception
1197 void CodeGenFunction::emitDestroy(llvm::Value *addr, QualType type,
1198 Destroyer &destroyer,
1199 bool useEHCleanupForArray) {
1200 const ArrayType *arrayType = getContext().getAsArrayType(type);
1202 return destroyer(*this, addr, type);
1204 llvm::Value *begin = addr;
1205 llvm::Value *length = emitArrayLength(arrayType, type, begin);
1207 // Normally we have to check whether the array is zero-length.
1208 bool checkZeroLength = true;
1210 // But if the array length is constant, we can suppress that.
1211 if (llvm::ConstantInt *constLength = dyn_cast<llvm::ConstantInt>(length)) {
1212 // ...and if it's constant zero, we can just skip the entire thing.
1213 if (constLength->isZero()) return;
1214 checkZeroLength = false;
1217 llvm::Value *end = Builder.CreateInBoundsGEP(begin, length);
1218 emitArrayDestroy(begin, end, type, destroyer,
1219 checkZeroLength, useEHCleanupForArray);
1222 /// emitArrayDestroy - Destroys all the elements of the given array,
1223 /// beginning from last to first. The array cannot be zero-length.
1225 /// \param begin - a type* denoting the first element of the array
1226 /// \param end - a type* denoting one past the end of the array
1227 /// \param type - the element type of the array
1228 /// \param destroyer - the function to call to destroy elements
1229 /// \param useEHCleanup - whether to push an EH cleanup to destroy
1230 /// the remaining elements in case the destruction of a single
1232 void CodeGenFunction::emitArrayDestroy(llvm::Value *begin,
1235 Destroyer &destroyer,
1236 bool checkZeroLength,
1237 bool useEHCleanup) {
1238 assert(!type->isArrayType());
1240 // The basic structure here is a do-while loop, because we don't
1241 // need to check for the zero-element case.
1242 llvm::BasicBlock *bodyBB = createBasicBlock("arraydestroy.body");
1243 llvm::BasicBlock *doneBB = createBasicBlock("arraydestroy.done");
1245 if (checkZeroLength) {
1246 llvm::Value *isEmpty = Builder.CreateICmpEQ(begin, end,
1247 "arraydestroy.isempty");
1248 Builder.CreateCondBr(isEmpty, doneBB, bodyBB);
1251 // Enter the loop body, making that address the current address.
1252 llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
1254 llvm::PHINode *elementPast =
1255 Builder.CreatePHI(begin->getType(), 2, "arraydestroy.elementPast");
1256 elementPast->addIncoming(end, entryBB);
1258 // Shift the address back by one element.
1259 llvm::Value *negativeOne = llvm::ConstantInt::get(SizeTy, -1, true);
1260 llvm::Value *element = Builder.CreateInBoundsGEP(elementPast, negativeOne,
1261 "arraydestroy.element");
1264 pushRegularPartialArrayCleanup(begin, element, type, destroyer);
1266 // Perform the actual destruction there.
1267 destroyer(*this, element, type);
1272 // Check whether we've reached the end.
1273 llvm::Value *done = Builder.CreateICmpEQ(element, begin, "arraydestroy.done");
1274 Builder.CreateCondBr(done, doneBB, bodyBB);
1275 elementPast->addIncoming(element, Builder.GetInsertBlock());
1281 /// Perform partial array destruction as if in an EH cleanup. Unlike
1282 /// emitArrayDestroy, the element type here may still be an array type.
1283 static void emitPartialArrayDestroy(CodeGenFunction &CGF,
1284 llvm::Value *begin, llvm::Value *end,
1286 CodeGenFunction::Destroyer &destroyer) {
1287 // If the element type is itself an array, drill down.
1288 unsigned arrayDepth = 0;
1289 while (const ArrayType *arrayType = CGF.getContext().getAsArrayType(type)) {
1290 // VLAs don't require a GEP index to walk into.
1291 if (!isa<VariableArrayType>(arrayType))
1293 type = arrayType->getElementType();
1297 llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, arrayDepth+1);
1299 SmallVector<llvm::Value*,4> gepIndices(arrayDepth, zero);
1300 begin = CGF.Builder.CreateInBoundsGEP(begin, gepIndices, "pad.arraybegin");
1301 end = CGF.Builder.CreateInBoundsGEP(end, gepIndices, "pad.arrayend");
1304 // Destroy the array. We don't ever need an EH cleanup because we
1305 // assume that we're in an EH cleanup ourselves, so a throwing
1306 // destructor causes an immediate terminate.
1307 CGF.emitArrayDestroy(begin, end, type, destroyer,
1308 /*checkZeroLength*/ true, /*useEHCleanup*/ false);
1312 /// RegularPartialArrayDestroy - a cleanup which performs a partial
1313 /// array destroy where the end pointer is regularly determined and
1314 /// does not need to be loaded from a local.
1315 class RegularPartialArrayDestroy : public EHScopeStack::Cleanup {
1316 llvm::Value *ArrayBegin;
1317 llvm::Value *ArrayEnd;
1318 QualType ElementType;
1319 CodeGenFunction::Destroyer &Destroyer;
1321 RegularPartialArrayDestroy(llvm::Value *arrayBegin, llvm::Value *arrayEnd,
1322 QualType elementType,
1323 CodeGenFunction::Destroyer *destroyer)
1324 : ArrayBegin(arrayBegin), ArrayEnd(arrayEnd),
1325 ElementType(elementType), Destroyer(*destroyer) {}
1327 void Emit(CodeGenFunction &CGF, Flags flags) {
1328 emitPartialArrayDestroy(CGF, ArrayBegin, ArrayEnd,
1329 ElementType, Destroyer);
1333 /// IrregularPartialArrayDestroy - a cleanup which performs a
1334 /// partial array destroy where the end pointer is irregularly
1335 /// determined and must be loaded from a local.
1336 class IrregularPartialArrayDestroy : public EHScopeStack::Cleanup {
1337 llvm::Value *ArrayBegin;
1338 llvm::Value *ArrayEndPointer;
1339 QualType ElementType;
1340 CodeGenFunction::Destroyer &Destroyer;
1342 IrregularPartialArrayDestroy(llvm::Value *arrayBegin,
1343 llvm::Value *arrayEndPointer,
1344 QualType elementType,
1345 CodeGenFunction::Destroyer *destroyer)
1346 : ArrayBegin(arrayBegin), ArrayEndPointer(arrayEndPointer),
1347 ElementType(elementType), Destroyer(*destroyer) {}
1349 void Emit(CodeGenFunction &CGF, Flags flags) {
1350 llvm::Value *arrayEnd = CGF.Builder.CreateLoad(ArrayEndPointer);
1351 emitPartialArrayDestroy(CGF, ArrayBegin, arrayEnd,
1352 ElementType, Destroyer);
1357 /// pushIrregularPartialArrayCleanup - Push an EH cleanup to destroy
1358 /// already-constructed elements of the given array. The cleanup
1359 /// may be popped with DeactivateCleanupBlock or PopCleanupBlock.
1361 /// \param elementType - the immediate element type of the array;
1362 /// possibly still an array type
1363 /// \param array - a value of type elementType*
1364 /// \param destructionKind - the kind of destruction required
1365 /// \param initializedElementCount - a value of type size_t* holding
1366 /// the number of successfully-constructed elements
1367 void CodeGenFunction::pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin,
1368 llvm::Value *arrayEndPointer,
1369 QualType elementType,
1370 Destroyer &destroyer) {
1371 pushFullExprCleanup<IrregularPartialArrayDestroy>(EHCleanup,
1372 arrayBegin, arrayEndPointer,
1373 elementType, &destroyer);
1376 /// pushRegularPartialArrayCleanup - Push an EH cleanup to destroy
1377 /// already-constructed elements of the given array. The cleanup
1378 /// may be popped with DeactivateCleanupBlock or PopCleanupBlock.
1380 /// \param elementType - the immediate element type of the array;
1381 /// possibly still an array type
1382 /// \param array - a value of type elementType*
1383 /// \param destructionKind - the kind of destruction required
1384 /// \param initializedElementCount - a value of type size_t* holding
1385 /// the number of successfully-constructed elements
1386 void CodeGenFunction::pushRegularPartialArrayCleanup(llvm::Value *arrayBegin,
1387 llvm::Value *arrayEnd,
1388 QualType elementType,
1389 Destroyer &destroyer) {
1390 pushFullExprCleanup<RegularPartialArrayDestroy>(EHCleanup,
1391 arrayBegin, arrayEnd,
1392 elementType, &destroyer);
1396 /// A cleanup to perform a release of an object at the end of a
1397 /// function. This is used to balance out the incoming +1 of a
1398 /// ns_consumed argument when we can't reasonably do that just by
1399 /// not doing the initial retain for a __block argument.
1400 struct ConsumeARCParameter : EHScopeStack::Cleanup {
1401 ConsumeARCParameter(llvm::Value *param) : Param(param) {}
1405 void Emit(CodeGenFunction &CGF, Flags flags) {
1406 CGF.EmitARCRelease(Param, /*precise*/ false);
1411 /// Emit an alloca (or GlobalValue depending on target)
1412 /// for the specified parameter and set up LocalDeclMap.
1413 void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg,
1415 // FIXME: Why isn't ImplicitParamDecl a ParmVarDecl?
1416 assert((isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)) &&
1417 "Invalid argument to EmitParmDecl");
1419 Arg->setName(D.getName());
1421 // Use better IR generation for certain implicit parameters.
1422 if (isa<ImplicitParamDecl>(D)) {
1423 // The only implicit argument a block has is its literal.
1425 LocalDeclMap[&D] = Arg;
1427 if (CGDebugInfo *DI = getDebugInfo()) {
1428 DI->setLocation(D.getLocation());
1429 DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, Arg, Builder);
1436 QualType Ty = D.getType();
1438 llvm::Value *DeclPtr;
1439 // If this is an aggregate or variable sized value, reuse the input pointer.
1440 if (!Ty->isConstantSizeType() ||
1441 CodeGenFunction::hasAggregateLLVMType(Ty)) {
1444 // Otherwise, create a temporary to hold the value.
1445 DeclPtr = CreateMemTemp(Ty, D.getName() + ".addr");
1447 bool doStore = true;
1449 Qualifiers qs = Ty.getQualifiers();
1451 if (Qualifiers::ObjCLifetime lt = qs.getObjCLifetime()) {
1452 // We honor __attribute__((ns_consumed)) for types with lifetime.
1453 // For __strong, it's handled by just skipping the initial retain;
1454 // otherwise we have to balance out the initial +1 with an extra
1455 // cleanup to do the release at the end of the function.
1456 bool isConsumed = D.hasAttr<NSConsumedAttr>();
1458 // 'self' is always formally __strong, but if this is not an
1459 // init method then we don't want to retain it.
1460 if (D.isARCPseudoStrong()) {
1461 const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CurCodeDecl);
1462 assert(&D == method->getSelfDecl());
1463 assert(lt == Qualifiers::OCL_Strong);
1464 assert(qs.hasConst());
1465 assert(method->getMethodFamily() != OMF_init);
1467 lt = Qualifiers::OCL_ExplicitNone;
1470 if (lt == Qualifiers::OCL_Strong) {
1472 // Don't use objc_retainBlock for block pointers, because we
1473 // don't want to Block_copy something just because we got it
1475 Arg = EmitARCRetainNonBlock(Arg);
1477 // Push the cleanup for a consumed parameter.
1479 EHStack.pushCleanup<ConsumeARCParameter>(getARCCleanupKind(), Arg);
1481 if (lt == Qualifiers::OCL_Weak) {
1482 EmitARCInitWeak(DeclPtr, Arg);
1483 doStore = false; // The weak init is a store, no need to do two
1487 // Enter the cleanup scope.
1488 EmitAutoVarWithLifetime(*this, D, DeclPtr, lt);
1491 // Store the initial value into the alloca.
1493 LValue lv = MakeAddrLValue(DeclPtr, Ty,
1494 getContext().getDeclAlign(&D).getQuantity());
1495 EmitStoreOfScalar(Arg, lv);
1499 llvm::Value *&DMEntry = LocalDeclMap[&D];
1500 assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
1503 // Emit debug info for param declaration.
1504 if (CGDebugInfo *DI = getDebugInfo())
1505 DI->EmitDeclareOfArgVariable(&D, DeclPtr, ArgNo, Builder);
1507 if (D.hasAttr<AnnotateAttr>())
1508 EmitVarAnnotations(&D, DeclPtr);