CGDecl.cpp revision 263508
1207753Smm//===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===// 2207753Smm// 3207753Smm// The LLVM Compiler Infrastructure 4207753Smm// 5207753Smm// This file is distributed under the University of Illinois Open Source 6207753Smm// License. See LICENSE.TXT for details. 7207753Smm// 8207753Smm//===----------------------------------------------------------------------===// 9207753Smm// 10207753Smm// This contains code to emit Decl nodes as LLVM code. 11207753Smm// 12207753Smm//===----------------------------------------------------------------------===// 13207753Smm 14207753Smm#include "CodeGenFunction.h" 15207753Smm#include "CGDebugInfo.h" 16207753Smm#include "CGOpenCLRuntime.h" 17207753Smm#include "CodeGenModule.h" 18207753Smm#include "clang/AST/ASTContext.h" 19207753Smm#include "clang/AST/CharUnits.h" 20207753Smm#include "clang/AST/Decl.h" 21207753Smm#include "clang/AST/DeclObjC.h" 22207753Smm#include "clang/Basic/SourceManager.h" 23207753Smm#include "clang/Basic/TargetInfo.h" 24207753Smm#include "clang/CodeGen/CGFunctionInfo.h" 25207753Smm#include "clang/Frontend/CodeGenOptions.h" 26207753Smm#include "llvm/IR/DataLayout.h" 27207753Smm#include "llvm/IR/GlobalVariable.h" 28207753Smm#include "llvm/IR/Intrinsics.h" 29207753Smm#include "llvm/IR/Type.h" 30207753Smmusing namespace clang; 31207753Smmusing namespace CodeGen; 32207753Smm 33207753Smm 34207753Smmvoid CodeGenFunction::EmitDecl(const Decl &D) { 35207753Smm switch (D.getKind()) { 36207753Smm case Decl::TranslationUnit: 37207753Smm case Decl::Namespace: 38207753Smm case Decl::UnresolvedUsingTypename: 39207753Smm case Decl::ClassTemplateSpecialization: 40207753Smm case Decl::ClassTemplatePartialSpecialization: 41207753Smm case Decl::VarTemplateSpecialization: 42207753Smm case Decl::VarTemplatePartialSpecialization: 43207753Smm case Decl::TemplateTypeParm: 44207753Smm case Decl::UnresolvedUsingValue: 45207753Smm case Decl::NonTypeTemplateParm: 46207753Smm case Decl::CXXMethod: 47207753Smm case Decl::CXXConstructor: 48207753Smm case Decl::CXXDestructor: 49207753Smm case Decl::CXXConversion: 50207753Smm case Decl::Field: 51207753Smm case Decl::MSProperty: 52207753Smm case Decl::IndirectField: 53207753Smm case Decl::ObjCIvar: 54207753Smm case Decl::ObjCAtDefsField: 55207753Smm case Decl::ParmVar: 56207753Smm case Decl::ImplicitParam: 57207753Smm case Decl::ClassTemplate: 58207753Smm case Decl::VarTemplate: 59207753Smm case Decl::FunctionTemplate: 60207753Smm case Decl::TypeAliasTemplate: 61207753Smm case Decl::TemplateTemplateParm: 62207753Smm case Decl::ObjCMethod: 63207753Smm case Decl::ObjCCategory: 64207753Smm case Decl::ObjCProtocol: 65207753Smm case Decl::ObjCInterface: 66207753Smm case Decl::ObjCCategoryImpl: 67207753Smm case Decl::ObjCImplementation: 68207753Smm case Decl::ObjCProperty: 69207753Smm case Decl::ObjCCompatibleAlias: 70207753Smm case Decl::AccessSpec: 71207753Smm case Decl::LinkageSpec: 72207753Smm case Decl::ObjCPropertyImpl: 73207753Smm case Decl::FileScopeAsm: 74207753Smm case Decl::Friend: 75207753Smm case Decl::FriendTemplate: 76207753Smm case Decl::Block: 77207753Smm case Decl::Captured: 78207753Smm case Decl::ClassScopeFunctionSpecialization: 79207753Smm case Decl::UsingShadow: 80207753Smm llvm_unreachable("Declaration should not be in declstmts!"); 81207753Smm case Decl::Function: // void X(); 82207753Smm case Decl::Record: // struct/union/class X; 83207753Smm case Decl::Enum: // enum X; 84207753Smm case Decl::EnumConstant: // enum ? { X = ? } 85207753Smm case Decl::CXXRecord: // struct/union/class X; [C++] 86207753Smm case Decl::StaticAssert: // static_assert(X, ""); [C++0x] 87207753Smm case Decl::Label: // __label__ x; 88207753Smm case Decl::Import: 89207753Smm case Decl::OMPThreadPrivate: 90207753Smm case Decl::Empty: 91207753Smm // None of these decls require codegen support. 92207753Smm return; 93207753Smm 94207753Smm case Decl::NamespaceAlias: 95207753Smm if (CGDebugInfo *DI = getDebugInfo()) 96207753Smm DI->EmitNamespaceAlias(cast<NamespaceAliasDecl>(D)); 97207753Smm return; 98207753Smm case Decl::Using: // using X; [C++] 99207753Smm if (CGDebugInfo *DI = getDebugInfo()) 100207753Smm DI->EmitUsingDecl(cast<UsingDecl>(D)); 101207753Smm return; 102207753Smm case Decl::UsingDirective: // using namespace X; [C++] 103207753Smm if (CGDebugInfo *DI = getDebugInfo()) 104207753Smm DI->EmitUsingDirective(cast<UsingDirectiveDecl>(D)); 105207753Smm return; 106207753Smm case Decl::Var: { 107207753Smm const VarDecl &VD = cast<VarDecl>(D); 108207753Smm assert(VD.isLocalVarDecl() && 109207753Smm "Should not see file-scope variables inside a function!"); 110207753Smm return EmitVarDecl(VD); 111207753Smm } 112207753Smm 113207753Smm case Decl::Typedef: // typedef int X; 114207753Smm case Decl::TypeAlias: { // using X = int; [C++0x] 115207753Smm const TypedefNameDecl &TD = cast<TypedefNameDecl>(D); 116207753Smm QualType Ty = TD.getUnderlyingType(); 117207753Smm 118207753Smm if (Ty->isVariablyModifiedType()) 119207753Smm EmitVariablyModifiedType(Ty); 120207753Smm } 121207753Smm } 122292588Sdelphij} 123207753Smm 124207753Smm/// EmitVarDecl - This method handles emission of any variable declaration 125207753Smm/// inside a function, including static vars etc. 126207753Smmvoid CodeGenFunction::EmitVarDecl(const VarDecl &D) { 127207753Smm if (D.isStaticLocal()) { 128207753Smm llvm::GlobalValue::LinkageTypes Linkage = 129207753Smm llvm::GlobalValue::InternalLinkage; 130207753Smm 131207753Smm // If the variable is externally visible, it must have weak linkage so it 132207753Smm // can be uniqued. 133207753Smm if (D.isExternallyVisible()) { 134207753Smm Linkage = llvm::GlobalValue::LinkOnceODRLinkage; 135207753Smm 136207753Smm // FIXME: We need to force the emission/use of a guard variable for 137207753Smm // some variables even if we can constant-evaluate them because 138207753Smm // we can't guarantee every translation unit will constant-evaluate them. 139207753Smm } 140207753Smm 141207753Smm return EmitStaticVarDecl(D, Linkage); 142207753Smm } 143207753Smm 144207753Smm if (D.hasExternalStorage()) 145207753Smm // Don't emit it now, allow it to be emitted lazily on its first use. 146207753Smm return; 147207753Smm 148207753Smm if (D.getStorageClass() == SC_OpenCLWorkGroupLocal) 149207753Smm return CGM.getOpenCLRuntime().EmitWorkGroupLocalVarDecl(*this, D); 150207753Smm 151207753Smm assert(D.hasLocalStorage()); 152207753Smm return EmitAutoVarDecl(D); 153207753Smm} 154207753Smm 155207753Smmstatic std::string GetStaticDeclName(CodeGenFunction &CGF, const VarDecl &D, 156207753Smm const char *Separator) { 157207753Smm CodeGenModule &CGM = CGF.CGM; 158207753Smm if (CGF.getLangOpts().CPlusPlus) { 159207753Smm StringRef Name = CGM.getMangledName(&D); 160207753Smm return Name.str(); 161207753Smm } 162207753Smm 163207753Smm std::string ContextName; 164207753Smm if (!CGF.CurFuncDecl) { 165207753Smm // Better be in a block declared in global scope. 166207753Smm const NamedDecl *ND = cast<NamedDecl>(&D); 167207753Smm const DeclContext *DC = ND->getDeclContext(); 168207753Smm if (const BlockDecl *BD = dyn_cast<BlockDecl>(DC)) { 169207753Smm MangleBuffer Name; 170207753Smm CGM.getBlockMangledName(GlobalDecl(), Name, BD); 171207753Smm ContextName = Name.getString(); 172207753Smm } 173207753Smm else 174207753Smm llvm_unreachable("Unknown context for block static var decl"); 175207753Smm } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CGF.CurFuncDecl)) { 176207753Smm StringRef Name = CGM.getMangledName(FD); 177207753Smm ContextName = Name.str(); 178207753Smm } else if (isa<ObjCMethodDecl>(CGF.CurFuncDecl)) 179207753Smm ContextName = CGF.CurFn->getName(); 180207753Smm else 181207753Smm llvm_unreachable("Unknown context for static var decl"); 182207753Smm 183207753Smm return ContextName + Separator + D.getNameAsString(); 184207753Smm} 185207753Smm 186207753Smmllvm::GlobalVariable * 187207753SmmCodeGenFunction::CreateStaticVarDecl(const VarDecl &D, 188207753Smm const char *Separator, 189207753Smm llvm::GlobalValue::LinkageTypes Linkage) { 190207753Smm QualType Ty = D.getType(); 191207753Smm assert(Ty->isConstantSizeType() && "VLAs can't be static"); 192207753Smm 193207753Smm // Use the label if the variable is renamed with the asm-label extension. 194312518Sdelphij std::string Name; 195207753Smm if (D.hasAttr<AsmLabelAttr>()) 196207753Smm Name = CGM.getMangledName(&D); 197312518Sdelphij else 198207753Smm Name = GetStaticDeclName(*this, D, Separator); 199207753Smm 200207753Smm llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(Ty); 201207753Smm unsigned AddrSpace = 202312518Sdelphij CGM.GetGlobalVarAddressSpace(&D, CGM.getContext().getTargetAddressSpace(Ty)); 203207753Smm llvm::GlobalVariable *GV = 204207753Smm new llvm::GlobalVariable(CGM.getModule(), LTy, 205312518Sdelphij Ty.isConstant(getContext()), Linkage, 206207753Smm CGM.EmitNullConstant(D.getType()), Name, 0, 207207753Smm llvm::GlobalVariable::NotThreadLocal, 208207753Smm AddrSpace); 209207753Smm GV->setAlignment(getContext().getDeclAlign(&D).getQuantity()); 210207753Smm CGM.setGlobalVisibility(GV, &D); 211207753Smm 212207753Smm if (D.getTLSKind()) 213207753Smm CGM.setTLSMode(GV, D); 214207753Smm 215207753Smm return GV; 216207753Smm} 217207753Smm 218207753Smm/// hasNontrivialDestruction - Determine whether a type's destruction is 219207753Smm/// non-trivial. If so, and the variable uses static initialization, we must 220207753Smm/// register its destructor to run on exit. 221207753Smmstatic bool hasNontrivialDestruction(QualType T) { 222207753Smm CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 223207753Smm return RD && !RD->hasTrivialDestructor(); 224207753Smm} 225207753Smm 226207753Smm/// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the 227207753Smm/// global variable that has already been created for it. If the initializer 228207753Smm/// has a different type than GV does, this may free GV and return a different 229207753Smm/// one. Otherwise it just returns GV. 230207753Smmllvm::GlobalVariable * 231207753SmmCodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D, 232207753Smm llvm::GlobalVariable *GV) { 233207753Smm llvm::Constant *Init = CGM.EmitConstantInit(D, this); 234207753Smm 235207753Smm // If constant emission failed, then this should be a C++ static 236207753Smm // initializer. 237207753Smm if (!Init) { 238207753Smm if (!getLangOpts().CPlusPlus) 239207753Smm CGM.ErrorUnsupported(D.getInit(), "constant l-value expression"); 240207753Smm else if (Builder.GetInsertBlock()) { 241207753Smm // Since we have a static initializer, this global variable can't 242207753Smm // be constant. 243207753Smm GV->setConstant(false); 244207753Smm 245207753Smm EmitCXXGuardedInit(D, GV, /*PerformInit*/true); 246207753Smm } 247207753Smm return GV; 248207753Smm } 249207753Smm 250207753Smm // The initializer may differ in type from the global. Rewrite 251207753Smm // the global to match the initializer. (We have to do this 252207753Smm // because some types, like unions, can't be completely represented 253207753Smm // in the LLVM type system.) 254207753Smm if (GV->getType()->getElementType() != Init->getType()) { 255207753Smm llvm::GlobalVariable *OldGV = GV; 256207753Smm 257207753Smm GV = new llvm::GlobalVariable(CGM.getModule(), Init->getType(), 258207753Smm OldGV->isConstant(), 259207753Smm OldGV->getLinkage(), Init, "", 260207753Smm /*InsertBefore*/ OldGV, 261207753Smm OldGV->getThreadLocalMode(), 262207753Smm CGM.getContext().getTargetAddressSpace(D.getType())); 263207753Smm GV->setVisibility(OldGV->getVisibility()); 264207753Smm 265207753Smm // Steal the name of the old global 266207753Smm GV->takeName(OldGV); 267207753Smm 268207753Smm // Replace all uses of the old global with the new global 269207753Smm llvm::Constant *NewPtrForOldDecl = 270207753Smm llvm::ConstantExpr::getBitCast(GV, OldGV->getType()); 271207753Smm OldGV->replaceAllUsesWith(NewPtrForOldDecl); 272207753Smm 273207753Smm // Erase the old global, since it is no longer used. 274207753Smm OldGV->eraseFromParent(); 275207753Smm } 276207753Smm 277207753Smm GV->setConstant(CGM.isTypeConstant(D.getType(), true)); 278207753Smm GV->setInitializer(Init); 279207753Smm 280207753Smm if (hasNontrivialDestruction(D.getType())) { 281207753Smm // We have a constant initializer, but a nontrivial destructor. We still 282207753Smm // need to perform a guarded "initialization" in order to register the 283213700Smm // destructor. 284207753Smm EmitCXXGuardedInit(D, GV, /*PerformInit*/false); 285207753Smm } 286207753Smm 287207753Smm return GV; 288207753Smm} 289207753Smm 290207753Smmvoid CodeGenFunction::EmitStaticVarDecl(const VarDecl &D, 291207753Smm llvm::GlobalValue::LinkageTypes Linkage) { 292207753Smm llvm::Value *&DMEntry = LocalDeclMap[&D]; 293207753Smm assert(DMEntry == 0 && "Decl already exists in localdeclmap!"); 294207753Smm 295207753Smm // Check to see if we already have a global variable for this 296207753Smm // declaration. This can happen when double-emitting function 297207753Smm // bodies, e.g. with complete and base constructors. 298292588Sdelphij llvm::Constant *addr = 299207753Smm CGM.getStaticLocalDeclAddress(&D); 300207753Smm 301292588Sdelphij llvm::GlobalVariable *var; 302207753Smm if (addr) { 303207753Smm var = cast<llvm::GlobalVariable>(addr->stripPointerCasts()); 304207753Smm } else { 305207753Smm addr = var = CreateStaticVarDecl(D, ".", Linkage); 306207753Smm } 307207753Smm 308207753Smm // Store into LocalDeclMap before generating initializer to handle 309207753Smm // circular references. 310207753Smm DMEntry = addr; 311207753Smm CGM.setStaticLocalDeclAddress(&D, addr); 312207753Smm 313207753Smm // We can't have a VLA here, but we can have a pointer to a VLA, 314207753Smm // even though that doesn't really make any sense. 315207753Smm // Make sure to evaluate VLA bounds now so that we have them for later. 316207753Smm if (D.getType()->isVariablyModifiedType()) 317207753Smm EmitVariablyModifiedType(D.getType()); 318207753Smm 319207753Smm // Save the type in case adding the initializer forces a type change. 320207753Smm llvm::Type *expectedType = addr->getType(); 321207753Smm 322207753Smm // If this value has an initializer, emit it. 323207753Smm if (D.getInit()) 324207753Smm var = AddInitializerToStaticVarDecl(D, var); 325207753Smm 326207753Smm var->setAlignment(getContext().getDeclAlign(&D).getQuantity()); 327207753Smm 328 if (D.hasAttr<AnnotateAttr>()) 329 CGM.AddGlobalAnnotations(&D, var); 330 331 if (const SectionAttr *SA = D.getAttr<SectionAttr>()) 332 var->setSection(SA->getName()); 333 334 if (D.hasAttr<UsedAttr>()) 335 CGM.AddUsedGlobal(var); 336 337 // We may have to cast the constant because of the initializer 338 // mismatch above. 339 // 340 // FIXME: It is really dangerous to store this in the map; if anyone 341 // RAUW's the GV uses of this constant will be invalid. 342 llvm::Constant *castedAddr = llvm::ConstantExpr::getBitCast(var, expectedType); 343 DMEntry = castedAddr; 344 CGM.setStaticLocalDeclAddress(&D, castedAddr); 345 346 // Emit global variable debug descriptor for static vars. 347 CGDebugInfo *DI = getDebugInfo(); 348 if (DI && 349 CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) { 350 DI->setLocation(D.getLocation()); 351 DI->EmitGlobalVariable(var, &D); 352 } 353} 354 355namespace { 356 struct DestroyObject : EHScopeStack::Cleanup { 357 DestroyObject(llvm::Value *addr, QualType type, 358 CodeGenFunction::Destroyer *destroyer, 359 bool useEHCleanupForArray) 360 : addr(addr), type(type), destroyer(destroyer), 361 useEHCleanupForArray(useEHCleanupForArray) {} 362 363 llvm::Value *addr; 364 QualType type; 365 CodeGenFunction::Destroyer *destroyer; 366 bool useEHCleanupForArray; 367 368 void Emit(CodeGenFunction &CGF, Flags flags) { 369 // Don't use an EH cleanup recursively from an EH cleanup. 370 bool useEHCleanupForArray = 371 flags.isForNormalCleanup() && this->useEHCleanupForArray; 372 373 CGF.emitDestroy(addr, type, destroyer, useEHCleanupForArray); 374 } 375 }; 376 377 struct DestroyNRVOVariable : EHScopeStack::Cleanup { 378 DestroyNRVOVariable(llvm::Value *addr, 379 const CXXDestructorDecl *Dtor, 380 llvm::Value *NRVOFlag) 381 : Dtor(Dtor), NRVOFlag(NRVOFlag), Loc(addr) {} 382 383 const CXXDestructorDecl *Dtor; 384 llvm::Value *NRVOFlag; 385 llvm::Value *Loc; 386 387 void Emit(CodeGenFunction &CGF, Flags flags) { 388 // Along the exceptions path we always execute the dtor. 389 bool NRVO = flags.isForNormalCleanup() && NRVOFlag; 390 391 llvm::BasicBlock *SkipDtorBB = 0; 392 if (NRVO) { 393 // If we exited via NRVO, we skip the destructor call. 394 llvm::BasicBlock *RunDtorBB = CGF.createBasicBlock("nrvo.unused"); 395 SkipDtorBB = CGF.createBasicBlock("nrvo.skipdtor"); 396 llvm::Value *DidNRVO = CGF.Builder.CreateLoad(NRVOFlag, "nrvo.val"); 397 CGF.Builder.CreateCondBr(DidNRVO, SkipDtorBB, RunDtorBB); 398 CGF.EmitBlock(RunDtorBB); 399 } 400 401 CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete, 402 /*ForVirtualBase=*/false, 403 /*Delegating=*/false, 404 Loc); 405 406 if (NRVO) CGF.EmitBlock(SkipDtorBB); 407 } 408 }; 409 410 struct CallStackRestore : EHScopeStack::Cleanup { 411 llvm::Value *Stack; 412 CallStackRestore(llvm::Value *Stack) : Stack(Stack) {} 413 void Emit(CodeGenFunction &CGF, Flags flags) { 414 llvm::Value *V = CGF.Builder.CreateLoad(Stack); 415 llvm::Value *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stackrestore); 416 CGF.Builder.CreateCall(F, V); 417 } 418 }; 419 420 struct ExtendGCLifetime : EHScopeStack::Cleanup { 421 const VarDecl &Var; 422 ExtendGCLifetime(const VarDecl *var) : Var(*var) {} 423 424 void Emit(CodeGenFunction &CGF, Flags flags) { 425 // Compute the address of the local variable, in case it's a 426 // byref or something. 427 DeclRefExpr DRE(const_cast<VarDecl*>(&Var), false, 428 Var.getType(), VK_LValue, SourceLocation()); 429 llvm::Value *value = CGF.EmitLoadOfScalar(CGF.EmitDeclRefLValue(&DRE), 430 SourceLocation()); 431 CGF.EmitExtendGCLifetime(value); 432 } 433 }; 434 435 struct CallCleanupFunction : EHScopeStack::Cleanup { 436 llvm::Constant *CleanupFn; 437 const CGFunctionInfo &FnInfo; 438 const VarDecl &Var; 439 440 CallCleanupFunction(llvm::Constant *CleanupFn, const CGFunctionInfo *Info, 441 const VarDecl *Var) 442 : CleanupFn(CleanupFn), FnInfo(*Info), Var(*Var) {} 443 444 void Emit(CodeGenFunction &CGF, Flags flags) { 445 DeclRefExpr DRE(const_cast<VarDecl*>(&Var), false, 446 Var.getType(), VK_LValue, SourceLocation()); 447 // Compute the address of the local variable, in case it's a byref 448 // or something. 449 llvm::Value *Addr = CGF.EmitDeclRefLValue(&DRE).getAddress(); 450 451 // In some cases, the type of the function argument will be different from 452 // the type of the pointer. An example of this is 453 // void f(void* arg); 454 // __attribute__((cleanup(f))) void *g; 455 // 456 // To fix this we insert a bitcast here. 457 QualType ArgTy = FnInfo.arg_begin()->type; 458 llvm::Value *Arg = 459 CGF.Builder.CreateBitCast(Addr, CGF.ConvertType(ArgTy)); 460 461 CallArgList Args; 462 Args.add(RValue::get(Arg), 463 CGF.getContext().getPointerType(Var.getType())); 464 CGF.EmitCall(FnInfo, CleanupFn, ReturnValueSlot(), Args); 465 } 466 }; 467 468 /// A cleanup to call @llvm.lifetime.end. 469 class CallLifetimeEnd : public EHScopeStack::Cleanup { 470 llvm::Value *Addr; 471 llvm::Value *Size; 472 public: 473 CallLifetimeEnd(llvm::Value *addr, llvm::Value *size) 474 : Addr(addr), Size(size) {} 475 476 void Emit(CodeGenFunction &CGF, Flags flags) { 477 llvm::Value *castAddr = CGF.Builder.CreateBitCast(Addr, CGF.Int8PtrTy); 478 CGF.Builder.CreateCall2(CGF.CGM.getLLVMLifetimeEndFn(), 479 Size, castAddr) 480 ->setDoesNotThrow(); 481 } 482 }; 483} 484 485/// EmitAutoVarWithLifetime - Does the setup required for an automatic 486/// variable with lifetime. 487static void EmitAutoVarWithLifetime(CodeGenFunction &CGF, const VarDecl &var, 488 llvm::Value *addr, 489 Qualifiers::ObjCLifetime lifetime) { 490 switch (lifetime) { 491 case Qualifiers::OCL_None: 492 llvm_unreachable("present but none"); 493 494 case Qualifiers::OCL_ExplicitNone: 495 // nothing to do 496 break; 497 498 case Qualifiers::OCL_Strong: { 499 CodeGenFunction::Destroyer *destroyer = 500 (var.hasAttr<ObjCPreciseLifetimeAttr>() 501 ? CodeGenFunction::destroyARCStrongPrecise 502 : CodeGenFunction::destroyARCStrongImprecise); 503 504 CleanupKind cleanupKind = CGF.getARCCleanupKind(); 505 CGF.pushDestroy(cleanupKind, addr, var.getType(), destroyer, 506 cleanupKind & EHCleanup); 507 break; 508 } 509 case Qualifiers::OCL_Autoreleasing: 510 // nothing to do 511 break; 512 513 case Qualifiers::OCL_Weak: 514 // __weak objects always get EH cleanups; otherwise, exceptions 515 // could cause really nasty crashes instead of mere leaks. 516 CGF.pushDestroy(NormalAndEHCleanup, addr, var.getType(), 517 CodeGenFunction::destroyARCWeak, 518 /*useEHCleanup*/ true); 519 break; 520 } 521} 522 523static bool isAccessedBy(const VarDecl &var, const Stmt *s) { 524 if (const Expr *e = dyn_cast<Expr>(s)) { 525 // Skip the most common kinds of expressions that make 526 // hierarchy-walking expensive. 527 s = e = e->IgnoreParenCasts(); 528 529 if (const DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e)) 530 return (ref->getDecl() == &var); 531 if (const BlockExpr *be = dyn_cast<BlockExpr>(e)) { 532 const BlockDecl *block = be->getBlockDecl(); 533 for (BlockDecl::capture_const_iterator i = block->capture_begin(), 534 e = block->capture_end(); i != e; ++i) { 535 if (i->getVariable() == &var) 536 return true; 537 } 538 } 539 } 540 541 for (Stmt::const_child_range children = s->children(); children; ++children) 542 // children might be null; as in missing decl or conditional of an if-stmt. 543 if ((*children) && isAccessedBy(var, *children)) 544 return true; 545 546 return false; 547} 548 549static bool isAccessedBy(const ValueDecl *decl, const Expr *e) { 550 if (!decl) return false; 551 if (!isa<VarDecl>(decl)) return false; 552 const VarDecl *var = cast<VarDecl>(decl); 553 return isAccessedBy(*var, e); 554} 555 556static void drillIntoBlockVariable(CodeGenFunction &CGF, 557 LValue &lvalue, 558 const VarDecl *var) { 559 lvalue.setAddress(CGF.BuildBlockByrefAddress(lvalue.getAddress(), var)); 560} 561 562void CodeGenFunction::EmitScalarInit(const Expr *init, 563 const ValueDecl *D, 564 LValue lvalue, 565 bool capturedByInit) { 566 Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime(); 567 if (!lifetime) { 568 llvm::Value *value = EmitScalarExpr(init); 569 if (capturedByInit) 570 drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D)); 571 EmitStoreThroughLValue(RValue::get(value), lvalue, true); 572 return; 573 } 574 575 // If we're emitting a value with lifetime, we have to do the 576 // initialization *before* we leave the cleanup scopes. 577 if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(init)) { 578 enterFullExpression(ewc); 579 init = ewc->getSubExpr(); 580 } 581 CodeGenFunction::RunCleanupsScope Scope(*this); 582 583 // We have to maintain the illusion that the variable is 584 // zero-initialized. If the variable might be accessed in its 585 // initializer, zero-initialize before running the initializer, then 586 // actually perform the initialization with an assign. 587 bool accessedByInit = false; 588 if (lifetime != Qualifiers::OCL_ExplicitNone) 589 accessedByInit = (capturedByInit || isAccessedBy(D, init)); 590 if (accessedByInit) { 591 LValue tempLV = lvalue; 592 // Drill down to the __block object if necessary. 593 if (capturedByInit) { 594 // We can use a simple GEP for this because it can't have been 595 // moved yet. 596 tempLV.setAddress(Builder.CreateStructGEP(tempLV.getAddress(), 597 getByRefValueLLVMField(cast<VarDecl>(D)))); 598 } 599 600 llvm::PointerType *ty 601 = cast<llvm::PointerType>(tempLV.getAddress()->getType()); 602 ty = cast<llvm::PointerType>(ty->getElementType()); 603 604 llvm::Value *zero = llvm::ConstantPointerNull::get(ty); 605 606 // If __weak, we want to use a barrier under certain conditions. 607 if (lifetime == Qualifiers::OCL_Weak) 608 EmitARCInitWeak(tempLV.getAddress(), zero); 609 610 // Otherwise just do a simple store. 611 else 612 EmitStoreOfScalar(zero, tempLV, /* isInitialization */ true); 613 } 614 615 // Emit the initializer. 616 llvm::Value *value = 0; 617 618 switch (lifetime) { 619 case Qualifiers::OCL_None: 620 llvm_unreachable("present but none"); 621 622 case Qualifiers::OCL_ExplicitNone: 623 // nothing to do 624 value = EmitScalarExpr(init); 625 break; 626 627 case Qualifiers::OCL_Strong: { 628 value = EmitARCRetainScalarExpr(init); 629 break; 630 } 631 632 case Qualifiers::OCL_Weak: { 633 // No way to optimize a producing initializer into this. It's not 634 // worth optimizing for, because the value will immediately 635 // disappear in the common case. 636 value = EmitScalarExpr(init); 637 638 if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D)); 639 if (accessedByInit) 640 EmitARCStoreWeak(lvalue.getAddress(), value, /*ignored*/ true); 641 else 642 EmitARCInitWeak(lvalue.getAddress(), value); 643 return; 644 } 645 646 case Qualifiers::OCL_Autoreleasing: 647 value = EmitARCRetainAutoreleaseScalarExpr(init); 648 break; 649 } 650 651 if (capturedByInit) drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D)); 652 653 // If the variable might have been accessed by its initializer, we 654 // might have to initialize with a barrier. We have to do this for 655 // both __weak and __strong, but __weak got filtered out above. 656 if (accessedByInit && lifetime == Qualifiers::OCL_Strong) { 657 llvm::Value *oldValue = EmitLoadOfScalar(lvalue, init->getExprLoc()); 658 EmitStoreOfScalar(value, lvalue, /* isInitialization */ true); 659 EmitARCRelease(oldValue, ARCImpreciseLifetime); 660 return; 661 } 662 663 EmitStoreOfScalar(value, lvalue, /* isInitialization */ true); 664} 665 666/// EmitScalarInit - Initialize the given lvalue with the given object. 667void CodeGenFunction::EmitScalarInit(llvm::Value *init, LValue lvalue) { 668 Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime(); 669 if (!lifetime) 670 return EmitStoreThroughLValue(RValue::get(init), lvalue, true); 671 672 switch (lifetime) { 673 case Qualifiers::OCL_None: 674 llvm_unreachable("present but none"); 675 676 case Qualifiers::OCL_ExplicitNone: 677 // nothing to do 678 break; 679 680 case Qualifiers::OCL_Strong: 681 init = EmitARCRetain(lvalue.getType(), init); 682 break; 683 684 case Qualifiers::OCL_Weak: 685 // Initialize and then skip the primitive store. 686 EmitARCInitWeak(lvalue.getAddress(), init); 687 return; 688 689 case Qualifiers::OCL_Autoreleasing: 690 init = EmitARCRetainAutorelease(lvalue.getType(), init); 691 break; 692 } 693 694 EmitStoreOfScalar(init, lvalue, /* isInitialization */ true); 695} 696 697/// canEmitInitWithFewStoresAfterMemset - Decide whether we can emit the 698/// non-zero parts of the specified initializer with equal or fewer than 699/// NumStores scalar stores. 700static bool canEmitInitWithFewStoresAfterMemset(llvm::Constant *Init, 701 unsigned &NumStores) { 702 // Zero and Undef never requires any extra stores. 703 if (isa<llvm::ConstantAggregateZero>(Init) || 704 isa<llvm::ConstantPointerNull>(Init) || 705 isa<llvm::UndefValue>(Init)) 706 return true; 707 if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) || 708 isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) || 709 isa<llvm::ConstantExpr>(Init)) 710 return Init->isNullValue() || NumStores--; 711 712 // See if we can emit each element. 713 if (isa<llvm::ConstantArray>(Init) || isa<llvm::ConstantStruct>(Init)) { 714 for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) { 715 llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i)); 716 if (!canEmitInitWithFewStoresAfterMemset(Elt, NumStores)) 717 return false; 718 } 719 return true; 720 } 721 722 if (llvm::ConstantDataSequential *CDS = 723 dyn_cast<llvm::ConstantDataSequential>(Init)) { 724 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { 725 llvm::Constant *Elt = CDS->getElementAsConstant(i); 726 if (!canEmitInitWithFewStoresAfterMemset(Elt, NumStores)) 727 return false; 728 } 729 return true; 730 } 731 732 // Anything else is hard and scary. 733 return false; 734} 735 736/// emitStoresForInitAfterMemset - For inits that 737/// canEmitInitWithFewStoresAfterMemset returned true for, emit the scalar 738/// stores that would be required. 739static void emitStoresForInitAfterMemset(llvm::Constant *Init, llvm::Value *Loc, 740 bool isVolatile, CGBuilderTy &Builder) { 741 assert(!Init->isNullValue() && !isa<llvm::UndefValue>(Init) && 742 "called emitStoresForInitAfterMemset for zero or undef value."); 743 744 if (isa<llvm::ConstantInt>(Init) || isa<llvm::ConstantFP>(Init) || 745 isa<llvm::ConstantVector>(Init) || isa<llvm::BlockAddress>(Init) || 746 isa<llvm::ConstantExpr>(Init)) { 747 Builder.CreateStore(Init, Loc, isVolatile); 748 return; 749 } 750 751 if (llvm::ConstantDataSequential *CDS = 752 dyn_cast<llvm::ConstantDataSequential>(Init)) { 753 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { 754 llvm::Constant *Elt = CDS->getElementAsConstant(i); 755 756 // If necessary, get a pointer to the element and emit it. 757 if (!Elt->isNullValue() && !isa<llvm::UndefValue>(Elt)) 758 emitStoresForInitAfterMemset(Elt, Builder.CreateConstGEP2_32(Loc, 0, i), 759 isVolatile, Builder); 760 } 761 return; 762 } 763 764 assert((isa<llvm::ConstantStruct>(Init) || isa<llvm::ConstantArray>(Init)) && 765 "Unknown value type!"); 766 767 for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) { 768 llvm::Constant *Elt = cast<llvm::Constant>(Init->getOperand(i)); 769 770 // If necessary, get a pointer to the element and emit it. 771 if (!Elt->isNullValue() && !isa<llvm::UndefValue>(Elt)) 772 emitStoresForInitAfterMemset(Elt, Builder.CreateConstGEP2_32(Loc, 0, i), 773 isVolatile, Builder); 774 } 775} 776 777 778/// shouldUseMemSetPlusStoresToInitialize - Decide whether we should use memset 779/// plus some stores to initialize a local variable instead of using a memcpy 780/// from a constant global. It is beneficial to use memset if the global is all 781/// zeros, or mostly zeros and large. 782static bool shouldUseMemSetPlusStoresToInitialize(llvm::Constant *Init, 783 uint64_t GlobalSize) { 784 // If a global is all zeros, always use a memset. 785 if (isa<llvm::ConstantAggregateZero>(Init)) return true; 786 787 // If a non-zero global is <= 32 bytes, always use a memcpy. If it is large, 788 // do it if it will require 6 or fewer scalar stores. 789 // TODO: Should budget depends on the size? Avoiding a large global warrants 790 // plopping in more stores. 791 unsigned StoreBudget = 6; 792 uint64_t SizeLimit = 32; 793 794 return GlobalSize > SizeLimit && 795 canEmitInitWithFewStoresAfterMemset(Init, StoreBudget); 796} 797 798/// Should we use the LLVM lifetime intrinsics for the given local variable? 799static bool shouldUseLifetimeMarkers(CodeGenFunction &CGF, const VarDecl &D, 800 unsigned Size) { 801 // Always emit lifetime markers in -fsanitize=use-after-scope mode. 802 if (CGF.getLangOpts().Sanitize.UseAfterScope) 803 return true; 804 // For now, only in optimized builds. 805 if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) 806 return false; 807 808 // Limit the size of marked objects to 32 bytes. We don't want to increase 809 // compile time by marking tiny objects. 810 unsigned SizeThreshold = 32; 811 812 return Size > SizeThreshold; 813} 814 815 816/// EmitAutoVarDecl - Emit code and set up an entry in LocalDeclMap for a 817/// variable declaration with auto, register, or no storage class specifier. 818/// These turn into simple stack objects, or GlobalValues depending on target. 819void CodeGenFunction::EmitAutoVarDecl(const VarDecl &D) { 820 AutoVarEmission emission = EmitAutoVarAlloca(D); 821 EmitAutoVarInit(emission); 822 EmitAutoVarCleanups(emission); 823} 824 825/// EmitAutoVarAlloca - Emit the alloca and debug information for a 826/// local variable. Does not emit initalization or destruction. 827CodeGenFunction::AutoVarEmission 828CodeGenFunction::EmitAutoVarAlloca(const VarDecl &D) { 829 QualType Ty = D.getType(); 830 831 AutoVarEmission emission(D); 832 833 bool isByRef = D.hasAttr<BlocksAttr>(); 834 emission.IsByRef = isByRef; 835 836 CharUnits alignment = getContext().getDeclAlign(&D); 837 emission.Alignment = alignment; 838 839 // If the type is variably-modified, emit all the VLA sizes for it. 840 if (Ty->isVariablyModifiedType()) 841 EmitVariablyModifiedType(Ty); 842 843 llvm::Value *DeclPtr; 844 if (Ty->isConstantSizeType()) { 845 bool NRVO = getLangOpts().ElideConstructors && 846 D.isNRVOVariable(); 847 848 // If this value is an array or struct with a statically determinable 849 // constant initializer, there are optimizations we can do. 850 // 851 // TODO: We should constant-evaluate the initializer of any variable, 852 // as long as it is initialized by a constant expression. Currently, 853 // isConstantInitializer produces wrong answers for structs with 854 // reference or bitfield members, and a few other cases, and checking 855 // for POD-ness protects us from some of these. 856 if (D.getInit() && (Ty->isArrayType() || Ty->isRecordType()) && 857 (D.isConstexpr() || 858 ((Ty.isPODType(getContext()) || 859 getContext().getBaseElementType(Ty)->isObjCObjectPointerType()) && 860 D.getInit()->isConstantInitializer(getContext(), false)))) { 861 862 // If the variable's a const type, and it's neither an NRVO 863 // candidate nor a __block variable and has no mutable members, 864 // emit it as a global instead. 865 if (CGM.getCodeGenOpts().MergeAllConstants && !NRVO && !isByRef && 866 CGM.isTypeConstant(Ty, true)) { 867 EmitStaticVarDecl(D, llvm::GlobalValue::InternalLinkage); 868 869 emission.Address = 0; // signal this condition to later callbacks 870 assert(emission.wasEmittedAsGlobal()); 871 return emission; 872 } 873 874 // Otherwise, tell the initialization code that we're in this case. 875 emission.IsConstantAggregate = true; 876 } 877 878 // A normal fixed sized variable becomes an alloca in the entry block, 879 // unless it's an NRVO variable. 880 llvm::Type *LTy = ConvertTypeForMem(Ty); 881 882 if (NRVO) { 883 // The named return value optimization: allocate this variable in the 884 // return slot, so that we can elide the copy when returning this 885 // variable (C++0x [class.copy]p34). 886 DeclPtr = ReturnValue; 887 888 if (const RecordType *RecordTy = Ty->getAs<RecordType>()) { 889 if (!cast<CXXRecordDecl>(RecordTy->getDecl())->hasTrivialDestructor()) { 890 // Create a flag that is used to indicate when the NRVO was applied 891 // to this variable. Set it to zero to indicate that NRVO was not 892 // applied. 893 llvm::Value *Zero = Builder.getFalse(); 894 llvm::Value *NRVOFlag = CreateTempAlloca(Zero->getType(), "nrvo"); 895 EnsureInsertPoint(); 896 Builder.CreateStore(Zero, NRVOFlag); 897 898 // Record the NRVO flag for this variable. 899 NRVOFlags[&D] = NRVOFlag; 900 emission.NRVOFlag = NRVOFlag; 901 } 902 } 903 } else { 904 if (isByRef) 905 LTy = BuildByRefType(&D); 906 907 llvm::AllocaInst *Alloc = CreateTempAlloca(LTy); 908 Alloc->setName(D.getName()); 909 910 CharUnits allocaAlignment = alignment; 911 if (isByRef) 912 allocaAlignment = std::max(allocaAlignment, 913 getContext().toCharUnitsFromBits(getTarget().getPointerAlign(0))); 914 Alloc->setAlignment(allocaAlignment.getQuantity()); 915 DeclPtr = Alloc; 916 917 // Emit a lifetime intrinsic if meaningful. There's no point 918 // in doing this if we don't have a valid insertion point (?). 919 uint64_t size = CGM.getDataLayout().getTypeAllocSize(LTy); 920 if (HaveInsertPoint() && shouldUseLifetimeMarkers(*this, D, size)) { 921 llvm::Value *sizeV = llvm::ConstantInt::get(Int64Ty, size); 922 923 emission.SizeForLifetimeMarkers = sizeV; 924 llvm::Value *castAddr = Builder.CreateBitCast(Alloc, Int8PtrTy); 925 Builder.CreateCall2(CGM.getLLVMLifetimeStartFn(), sizeV, castAddr) 926 ->setDoesNotThrow(); 927 } else { 928 assert(!emission.useLifetimeMarkers()); 929 } 930 } 931 } else { 932 EnsureInsertPoint(); 933 934 if (!DidCallStackSave) { 935 // Save the stack. 936 llvm::Value *Stack = CreateTempAlloca(Int8PtrTy, "saved_stack"); 937 938 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::stacksave); 939 llvm::Value *V = Builder.CreateCall(F); 940 941 Builder.CreateStore(V, Stack); 942 943 DidCallStackSave = true; 944 945 // Push a cleanup block and restore the stack there. 946 // FIXME: in general circumstances, this should be an EH cleanup. 947 EHStack.pushCleanup<CallStackRestore>(NormalCleanup, Stack); 948 } 949 950 llvm::Value *elementCount; 951 QualType elementType; 952 llvm::tie(elementCount, elementType) = getVLASize(Ty); 953 954 llvm::Type *llvmTy = ConvertTypeForMem(elementType); 955 956 // Allocate memory for the array. 957 llvm::AllocaInst *vla = Builder.CreateAlloca(llvmTy, elementCount, "vla"); 958 vla->setAlignment(alignment.getQuantity()); 959 960 DeclPtr = vla; 961 } 962 963 llvm::Value *&DMEntry = LocalDeclMap[&D]; 964 assert(DMEntry == 0 && "Decl already exists in localdeclmap!"); 965 DMEntry = DeclPtr; 966 emission.Address = DeclPtr; 967 968 // Emit debug info for local var declaration. 969 if (HaveInsertPoint()) 970 if (CGDebugInfo *DI = getDebugInfo()) { 971 if (CGM.getCodeGenOpts().getDebugInfo() 972 >= CodeGenOptions::LimitedDebugInfo) { 973 DI->setLocation(D.getLocation()); 974 DI->EmitDeclareOfAutoVariable(&D, DeclPtr, Builder); 975 } 976 } 977 978 if (D.hasAttr<AnnotateAttr>()) 979 EmitVarAnnotations(&D, emission.Address); 980 981 return emission; 982} 983 984/// Determines whether the given __block variable is potentially 985/// captured by the given expression. 986static bool isCapturedBy(const VarDecl &var, const Expr *e) { 987 // Skip the most common kinds of expressions that make 988 // hierarchy-walking expensive. 989 e = e->IgnoreParenCasts(); 990 991 if (const BlockExpr *be = dyn_cast<BlockExpr>(e)) { 992 const BlockDecl *block = be->getBlockDecl(); 993 for (BlockDecl::capture_const_iterator i = block->capture_begin(), 994 e = block->capture_end(); i != e; ++i) { 995 if (i->getVariable() == &var) 996 return true; 997 } 998 999 // No need to walk into the subexpressions. 1000 return false; 1001 } 1002 1003 if (const StmtExpr *SE = dyn_cast<StmtExpr>(e)) { 1004 const CompoundStmt *CS = SE->getSubStmt(); 1005 for (CompoundStmt::const_body_iterator BI = CS->body_begin(), 1006 BE = CS->body_end(); BI != BE; ++BI) 1007 if (Expr *E = dyn_cast<Expr>((*BI))) { 1008 if (isCapturedBy(var, E)) 1009 return true; 1010 } 1011 else if (DeclStmt *DS = dyn_cast<DeclStmt>((*BI))) { 1012 // special case declarations 1013 for (DeclStmt::decl_iterator I = DS->decl_begin(), E = DS->decl_end(); 1014 I != E; ++I) { 1015 if (VarDecl *VD = dyn_cast<VarDecl>((*I))) { 1016 Expr *Init = VD->getInit(); 1017 if (Init && isCapturedBy(var, Init)) 1018 return true; 1019 } 1020 } 1021 } 1022 else 1023 // FIXME. Make safe assumption assuming arbitrary statements cause capturing. 1024 // Later, provide code to poke into statements for capture analysis. 1025 return true; 1026 return false; 1027 } 1028 1029 for (Stmt::const_child_range children = e->children(); children; ++children) 1030 if (isCapturedBy(var, cast<Expr>(*children))) 1031 return true; 1032 1033 return false; 1034} 1035 1036/// \brief Determine whether the given initializer is trivial in the sense 1037/// that it requires no code to be generated. 1038static bool isTrivialInitializer(const Expr *Init) { 1039 if (!Init) 1040 return true; 1041 1042 if (const CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Init)) 1043 if (CXXConstructorDecl *Constructor = Construct->getConstructor()) 1044 if (Constructor->isTrivial() && 1045 Constructor->isDefaultConstructor() && 1046 !Construct->requiresZeroInitialization()) 1047 return true; 1048 1049 return false; 1050} 1051void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) { 1052 assert(emission.Variable && "emission was not valid!"); 1053 1054 // If this was emitted as a global constant, we're done. 1055 if (emission.wasEmittedAsGlobal()) return; 1056 1057 const VarDecl &D = *emission.Variable; 1058 QualType type = D.getType(); 1059 1060 // If this local has an initializer, emit it now. 1061 const Expr *Init = D.getInit(); 1062 1063 // If we are at an unreachable point, we don't need to emit the initializer 1064 // unless it contains a label. 1065 if (!HaveInsertPoint()) { 1066 if (!Init || !ContainsLabel(Init)) return; 1067 EnsureInsertPoint(); 1068 } 1069 1070 // Initialize the structure of a __block variable. 1071 if (emission.IsByRef) 1072 emitByrefStructureInit(emission); 1073 1074 if (isTrivialInitializer(Init)) 1075 return; 1076 1077 CharUnits alignment = emission.Alignment; 1078 1079 // Check whether this is a byref variable that's potentially 1080 // captured and moved by its own initializer. If so, we'll need to 1081 // emit the initializer first, then copy into the variable. 1082 bool capturedByInit = emission.IsByRef && isCapturedBy(D, Init); 1083 1084 llvm::Value *Loc = 1085 capturedByInit ? emission.Address : emission.getObjectAddress(*this); 1086 1087 llvm::Constant *constant = 0; 1088 if (emission.IsConstantAggregate || D.isConstexpr()) { 1089 assert(!capturedByInit && "constant init contains a capturing block?"); 1090 constant = CGM.EmitConstantInit(D, this); 1091 } 1092 1093 if (!constant) { 1094 LValue lv = MakeAddrLValue(Loc, type, alignment); 1095 lv.setNonGC(true); 1096 return EmitExprAsInit(Init, &D, lv, capturedByInit); 1097 } 1098 1099 if (!emission.IsConstantAggregate) { 1100 // For simple scalar/complex initialization, store the value directly. 1101 LValue lv = MakeAddrLValue(Loc, type, alignment); 1102 lv.setNonGC(true); 1103 return EmitStoreThroughLValue(RValue::get(constant), lv, true); 1104 } 1105 1106 // If this is a simple aggregate initialization, we can optimize it 1107 // in various ways. 1108 bool isVolatile = type.isVolatileQualified(); 1109 1110 llvm::Value *SizeVal = 1111 llvm::ConstantInt::get(IntPtrTy, 1112 getContext().getTypeSizeInChars(type).getQuantity()); 1113 1114 llvm::Type *BP = Int8PtrTy; 1115 if (Loc->getType() != BP) 1116 Loc = Builder.CreateBitCast(Loc, BP); 1117 1118 // If the initializer is all or mostly zeros, codegen with memset then do 1119 // a few stores afterward. 1120 if (shouldUseMemSetPlusStoresToInitialize(constant, 1121 CGM.getDataLayout().getTypeAllocSize(constant->getType()))) { 1122 Builder.CreateMemSet(Loc, llvm::ConstantInt::get(Int8Ty, 0), SizeVal, 1123 alignment.getQuantity(), isVolatile); 1124 // Zero and undef don't require a stores. 1125 if (!constant->isNullValue() && !isa<llvm::UndefValue>(constant)) { 1126 Loc = Builder.CreateBitCast(Loc, constant->getType()->getPointerTo()); 1127 emitStoresForInitAfterMemset(constant, Loc, isVolatile, Builder); 1128 } 1129 } else { 1130 // Otherwise, create a temporary global with the initializer then 1131 // memcpy from the global to the alloca. 1132 std::string Name = GetStaticDeclName(*this, D, "."); 1133 llvm::GlobalVariable *GV = 1134 new llvm::GlobalVariable(CGM.getModule(), constant->getType(), true, 1135 llvm::GlobalValue::PrivateLinkage, 1136 constant, Name); 1137 GV->setAlignment(alignment.getQuantity()); 1138 GV->setUnnamedAddr(true); 1139 1140 llvm::Value *SrcPtr = GV; 1141 if (SrcPtr->getType() != BP) 1142 SrcPtr = Builder.CreateBitCast(SrcPtr, BP); 1143 1144 Builder.CreateMemCpy(Loc, SrcPtr, SizeVal, alignment.getQuantity(), 1145 isVolatile); 1146 } 1147} 1148 1149/// Emit an expression as an initializer for a variable at the given 1150/// location. The expression is not necessarily the normal 1151/// initializer for the variable, and the address is not necessarily 1152/// its normal location. 1153/// 1154/// \param init the initializing expression 1155/// \param var the variable to act as if we're initializing 1156/// \param loc the address to initialize; its type is a pointer 1157/// to the LLVM mapping of the variable's type 1158/// \param alignment the alignment of the address 1159/// \param capturedByInit true if the variable is a __block variable 1160/// whose address is potentially changed by the initializer 1161void CodeGenFunction::EmitExprAsInit(const Expr *init, 1162 const ValueDecl *D, 1163 LValue lvalue, 1164 bool capturedByInit) { 1165 QualType type = D->getType(); 1166 1167 if (type->isReferenceType()) { 1168 RValue rvalue = EmitReferenceBindingToExpr(init); 1169 if (capturedByInit) 1170 drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D)); 1171 EmitStoreThroughLValue(rvalue, lvalue, true); 1172 return; 1173 } 1174 switch (getEvaluationKind(type)) { 1175 case TEK_Scalar: 1176 EmitScalarInit(init, D, lvalue, capturedByInit); 1177 return; 1178 case TEK_Complex: { 1179 ComplexPairTy complex = EmitComplexExpr(init); 1180 if (capturedByInit) 1181 drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D)); 1182 EmitStoreOfComplex(complex, lvalue, /*init*/ true); 1183 return; 1184 } 1185 case TEK_Aggregate: 1186 if (type->isAtomicType()) { 1187 EmitAtomicInit(const_cast<Expr*>(init), lvalue); 1188 } else { 1189 // TODO: how can we delay here if D is captured by its initializer? 1190 EmitAggExpr(init, AggValueSlot::forLValue(lvalue, 1191 AggValueSlot::IsDestructed, 1192 AggValueSlot::DoesNotNeedGCBarriers, 1193 AggValueSlot::IsNotAliased)); 1194 } 1195 return; 1196 } 1197 llvm_unreachable("bad evaluation kind"); 1198} 1199 1200/// Enter a destroy cleanup for the given local variable. 1201void CodeGenFunction::emitAutoVarTypeCleanup( 1202 const CodeGenFunction::AutoVarEmission &emission, 1203 QualType::DestructionKind dtorKind) { 1204 assert(dtorKind != QualType::DK_none); 1205 1206 // Note that for __block variables, we want to destroy the 1207 // original stack object, not the possibly forwarded object. 1208 llvm::Value *addr = emission.getObjectAddress(*this); 1209 1210 const VarDecl *var = emission.Variable; 1211 QualType type = var->getType(); 1212 1213 CleanupKind cleanupKind = NormalAndEHCleanup; 1214 CodeGenFunction::Destroyer *destroyer = 0; 1215 1216 switch (dtorKind) { 1217 case QualType::DK_none: 1218 llvm_unreachable("no cleanup for trivially-destructible variable"); 1219 1220 case QualType::DK_cxx_destructor: 1221 // If there's an NRVO flag on the emission, we need a different 1222 // cleanup. 1223 if (emission.NRVOFlag) { 1224 assert(!type->isArrayType()); 1225 CXXDestructorDecl *dtor = type->getAsCXXRecordDecl()->getDestructor(); 1226 EHStack.pushCleanup<DestroyNRVOVariable>(cleanupKind, addr, dtor, 1227 emission.NRVOFlag); 1228 return; 1229 } 1230 break; 1231 1232 case QualType::DK_objc_strong_lifetime: 1233 // Suppress cleanups for pseudo-strong variables. 1234 if (var->isARCPseudoStrong()) return; 1235 1236 // Otherwise, consider whether to use an EH cleanup or not. 1237 cleanupKind = getARCCleanupKind(); 1238 1239 // Use the imprecise destroyer by default. 1240 if (!var->hasAttr<ObjCPreciseLifetimeAttr>()) 1241 destroyer = CodeGenFunction::destroyARCStrongImprecise; 1242 break; 1243 1244 case QualType::DK_objc_weak_lifetime: 1245 break; 1246 } 1247 1248 // If we haven't chosen a more specific destroyer, use the default. 1249 if (!destroyer) destroyer = getDestroyer(dtorKind); 1250 1251 // Use an EH cleanup in array destructors iff the destructor itself 1252 // is being pushed as an EH cleanup. 1253 bool useEHCleanup = (cleanupKind & EHCleanup); 1254 EHStack.pushCleanup<DestroyObject>(cleanupKind, addr, type, destroyer, 1255 useEHCleanup); 1256} 1257 1258void CodeGenFunction::EmitAutoVarCleanups(const AutoVarEmission &emission) { 1259 assert(emission.Variable && "emission was not valid!"); 1260 1261 // If this was emitted as a global constant, we're done. 1262 if (emission.wasEmittedAsGlobal()) return; 1263 1264 // If we don't have an insertion point, we're done. Sema prevents 1265 // us from jumping into any of these scopes anyway. 1266 if (!HaveInsertPoint()) return; 1267 1268 const VarDecl &D = *emission.Variable; 1269 1270 // Make sure we call @llvm.lifetime.end. This needs to happen 1271 // *last*, so the cleanup needs to be pushed *first*. 1272 if (emission.useLifetimeMarkers()) { 1273 EHStack.pushCleanup<CallLifetimeEnd>(NormalCleanup, 1274 emission.getAllocatedAddress(), 1275 emission.getSizeForLifetimeMarkers()); 1276 } 1277 1278 // Check the type for a cleanup. 1279 if (QualType::DestructionKind dtorKind = D.getType().isDestructedType()) 1280 emitAutoVarTypeCleanup(emission, dtorKind); 1281 1282 // In GC mode, honor objc_precise_lifetime. 1283 if (getLangOpts().getGC() != LangOptions::NonGC && 1284 D.hasAttr<ObjCPreciseLifetimeAttr>()) { 1285 EHStack.pushCleanup<ExtendGCLifetime>(NormalCleanup, &D); 1286 } 1287 1288 // Handle the cleanup attribute. 1289 if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) { 1290 const FunctionDecl *FD = CA->getFunctionDecl(); 1291 1292 llvm::Constant *F = CGM.GetAddrOfFunction(FD); 1293 assert(F && "Could not find function!"); 1294 1295 const CGFunctionInfo &Info = CGM.getTypes().arrangeFunctionDeclaration(FD); 1296 EHStack.pushCleanup<CallCleanupFunction>(NormalAndEHCleanup, F, &Info, &D); 1297 } 1298 1299 // If this is a block variable, call _Block_object_destroy 1300 // (on the unforwarded address). 1301 if (emission.IsByRef) 1302 enterByrefCleanup(emission); 1303} 1304 1305CodeGenFunction::Destroyer * 1306CodeGenFunction::getDestroyer(QualType::DestructionKind kind) { 1307 switch (kind) { 1308 case QualType::DK_none: llvm_unreachable("no destroyer for trivial dtor"); 1309 case QualType::DK_cxx_destructor: 1310 return destroyCXXObject; 1311 case QualType::DK_objc_strong_lifetime: 1312 return destroyARCStrongPrecise; 1313 case QualType::DK_objc_weak_lifetime: 1314 return destroyARCWeak; 1315 } 1316 llvm_unreachable("Unknown DestructionKind"); 1317} 1318 1319/// pushEHDestroy - Push the standard destructor for the given type as 1320/// an EH-only cleanup. 1321void CodeGenFunction::pushEHDestroy(QualType::DestructionKind dtorKind, 1322 llvm::Value *addr, QualType type) { 1323 assert(dtorKind && "cannot push destructor for trivial type"); 1324 assert(needsEHCleanup(dtorKind)); 1325 1326 pushDestroy(EHCleanup, addr, type, getDestroyer(dtorKind), true); 1327} 1328 1329/// pushDestroy - Push the standard destructor for the given type as 1330/// at least a normal cleanup. 1331void CodeGenFunction::pushDestroy(QualType::DestructionKind dtorKind, 1332 llvm::Value *addr, QualType type) { 1333 assert(dtorKind && "cannot push destructor for trivial type"); 1334 1335 CleanupKind cleanupKind = getCleanupKind(dtorKind); 1336 pushDestroy(cleanupKind, addr, type, getDestroyer(dtorKind), 1337 cleanupKind & EHCleanup); 1338} 1339 1340void CodeGenFunction::pushDestroy(CleanupKind cleanupKind, llvm::Value *addr, 1341 QualType type, Destroyer *destroyer, 1342 bool useEHCleanupForArray) { 1343 pushFullExprCleanup<DestroyObject>(cleanupKind, addr, type, 1344 destroyer, useEHCleanupForArray); 1345} 1346 1347void CodeGenFunction::pushLifetimeExtendedDestroy( 1348 CleanupKind cleanupKind, llvm::Value *addr, QualType type, 1349 Destroyer *destroyer, bool useEHCleanupForArray) { 1350 assert(!isInConditionalBranch() && 1351 "performing lifetime extension from within conditional"); 1352 1353 // Push an EH-only cleanup for the object now. 1354 // FIXME: When popping normal cleanups, we need to keep this EH cleanup 1355 // around in case a temporary's destructor throws an exception. 1356 if (cleanupKind & EHCleanup) 1357 EHStack.pushCleanup<DestroyObject>( 1358 static_cast<CleanupKind>(cleanupKind & ~NormalCleanup), addr, type, 1359 destroyer, useEHCleanupForArray); 1360 1361 // Remember that we need to push a full cleanup for the object at the 1362 // end of the full-expression. 1363 pushCleanupAfterFullExpr<DestroyObject>( 1364 cleanupKind, addr, type, destroyer, useEHCleanupForArray); 1365} 1366 1367/// emitDestroy - Immediately perform the destruction of the given 1368/// object. 1369/// 1370/// \param addr - the address of the object; a type* 1371/// \param type - the type of the object; if an array type, all 1372/// objects are destroyed in reverse order 1373/// \param destroyer - the function to call to destroy individual 1374/// elements 1375/// \param useEHCleanupForArray - whether an EH cleanup should be 1376/// used when destroying array elements, in case one of the 1377/// destructions throws an exception 1378void CodeGenFunction::emitDestroy(llvm::Value *addr, QualType type, 1379 Destroyer *destroyer, 1380 bool useEHCleanupForArray) { 1381 const ArrayType *arrayType = getContext().getAsArrayType(type); 1382 if (!arrayType) 1383 return destroyer(*this, addr, type); 1384 1385 llvm::Value *begin = addr; 1386 llvm::Value *length = emitArrayLength(arrayType, type, begin); 1387 1388 // Normally we have to check whether the array is zero-length. 1389 bool checkZeroLength = true; 1390 1391 // But if the array length is constant, we can suppress that. 1392 if (llvm::ConstantInt *constLength = dyn_cast<llvm::ConstantInt>(length)) { 1393 // ...and if it's constant zero, we can just skip the entire thing. 1394 if (constLength->isZero()) return; 1395 checkZeroLength = false; 1396 } 1397 1398 llvm::Value *end = Builder.CreateInBoundsGEP(begin, length); 1399 emitArrayDestroy(begin, end, type, destroyer, 1400 checkZeroLength, useEHCleanupForArray); 1401} 1402 1403/// emitArrayDestroy - Destroys all the elements of the given array, 1404/// beginning from last to first. The array cannot be zero-length. 1405/// 1406/// \param begin - a type* denoting the first element of the array 1407/// \param end - a type* denoting one past the end of the array 1408/// \param type - the element type of the array 1409/// \param destroyer - the function to call to destroy elements 1410/// \param useEHCleanup - whether to push an EH cleanup to destroy 1411/// the remaining elements in case the destruction of a single 1412/// element throws 1413void CodeGenFunction::emitArrayDestroy(llvm::Value *begin, 1414 llvm::Value *end, 1415 QualType type, 1416 Destroyer *destroyer, 1417 bool checkZeroLength, 1418 bool useEHCleanup) { 1419 assert(!type->isArrayType()); 1420 1421 // The basic structure here is a do-while loop, because we don't 1422 // need to check for the zero-element case. 1423 llvm::BasicBlock *bodyBB = createBasicBlock("arraydestroy.body"); 1424 llvm::BasicBlock *doneBB = createBasicBlock("arraydestroy.done"); 1425 1426 if (checkZeroLength) { 1427 llvm::Value *isEmpty = Builder.CreateICmpEQ(begin, end, 1428 "arraydestroy.isempty"); 1429 Builder.CreateCondBr(isEmpty, doneBB, bodyBB); 1430 } 1431 1432 // Enter the loop body, making that address the current address. 1433 llvm::BasicBlock *entryBB = Builder.GetInsertBlock(); 1434 EmitBlock(bodyBB); 1435 llvm::PHINode *elementPast = 1436 Builder.CreatePHI(begin->getType(), 2, "arraydestroy.elementPast"); 1437 elementPast->addIncoming(end, entryBB); 1438 1439 // Shift the address back by one element. 1440 llvm::Value *negativeOne = llvm::ConstantInt::get(SizeTy, -1, true); 1441 llvm::Value *element = Builder.CreateInBoundsGEP(elementPast, negativeOne, 1442 "arraydestroy.element"); 1443 1444 if (useEHCleanup) 1445 pushRegularPartialArrayCleanup(begin, element, type, destroyer); 1446 1447 // Perform the actual destruction there. 1448 destroyer(*this, element, type); 1449 1450 if (useEHCleanup) 1451 PopCleanupBlock(); 1452 1453 // Check whether we've reached the end. 1454 llvm::Value *done = Builder.CreateICmpEQ(element, begin, "arraydestroy.done"); 1455 Builder.CreateCondBr(done, doneBB, bodyBB); 1456 elementPast->addIncoming(element, Builder.GetInsertBlock()); 1457 1458 // Done. 1459 EmitBlock(doneBB); 1460} 1461 1462/// Perform partial array destruction as if in an EH cleanup. Unlike 1463/// emitArrayDestroy, the element type here may still be an array type. 1464static void emitPartialArrayDestroy(CodeGenFunction &CGF, 1465 llvm::Value *begin, llvm::Value *end, 1466 QualType type, 1467 CodeGenFunction::Destroyer *destroyer) { 1468 // If the element type is itself an array, drill down. 1469 unsigned arrayDepth = 0; 1470 while (const ArrayType *arrayType = CGF.getContext().getAsArrayType(type)) { 1471 // VLAs don't require a GEP index to walk into. 1472 if (!isa<VariableArrayType>(arrayType)) 1473 arrayDepth++; 1474 type = arrayType->getElementType(); 1475 } 1476 1477 if (arrayDepth) { 1478 llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, arrayDepth+1); 1479 1480 SmallVector<llvm::Value*,4> gepIndices(arrayDepth, zero); 1481 begin = CGF.Builder.CreateInBoundsGEP(begin, gepIndices, "pad.arraybegin"); 1482 end = CGF.Builder.CreateInBoundsGEP(end, gepIndices, "pad.arrayend"); 1483 } 1484 1485 // Destroy the array. We don't ever need an EH cleanup because we 1486 // assume that we're in an EH cleanup ourselves, so a throwing 1487 // destructor causes an immediate terminate. 1488 CGF.emitArrayDestroy(begin, end, type, destroyer, 1489 /*checkZeroLength*/ true, /*useEHCleanup*/ false); 1490} 1491 1492namespace { 1493 /// RegularPartialArrayDestroy - a cleanup which performs a partial 1494 /// array destroy where the end pointer is regularly determined and 1495 /// does not need to be loaded from a local. 1496 class RegularPartialArrayDestroy : public EHScopeStack::Cleanup { 1497 llvm::Value *ArrayBegin; 1498 llvm::Value *ArrayEnd; 1499 QualType ElementType; 1500 CodeGenFunction::Destroyer *Destroyer; 1501 public: 1502 RegularPartialArrayDestroy(llvm::Value *arrayBegin, llvm::Value *arrayEnd, 1503 QualType elementType, 1504 CodeGenFunction::Destroyer *destroyer) 1505 : ArrayBegin(arrayBegin), ArrayEnd(arrayEnd), 1506 ElementType(elementType), Destroyer(destroyer) {} 1507 1508 void Emit(CodeGenFunction &CGF, Flags flags) { 1509 emitPartialArrayDestroy(CGF, ArrayBegin, ArrayEnd, 1510 ElementType, Destroyer); 1511 } 1512 }; 1513 1514 /// IrregularPartialArrayDestroy - a cleanup which performs a 1515 /// partial array destroy where the end pointer is irregularly 1516 /// determined and must be loaded from a local. 1517 class IrregularPartialArrayDestroy : public EHScopeStack::Cleanup { 1518 llvm::Value *ArrayBegin; 1519 llvm::Value *ArrayEndPointer; 1520 QualType ElementType; 1521 CodeGenFunction::Destroyer *Destroyer; 1522 public: 1523 IrregularPartialArrayDestroy(llvm::Value *arrayBegin, 1524 llvm::Value *arrayEndPointer, 1525 QualType elementType, 1526 CodeGenFunction::Destroyer *destroyer) 1527 : ArrayBegin(arrayBegin), ArrayEndPointer(arrayEndPointer), 1528 ElementType(elementType), Destroyer(destroyer) {} 1529 1530 void Emit(CodeGenFunction &CGF, Flags flags) { 1531 llvm::Value *arrayEnd = CGF.Builder.CreateLoad(ArrayEndPointer); 1532 emitPartialArrayDestroy(CGF, ArrayBegin, arrayEnd, 1533 ElementType, Destroyer); 1534 } 1535 }; 1536} 1537 1538/// pushIrregularPartialArrayCleanup - Push an EH cleanup to destroy 1539/// already-constructed elements of the given array. The cleanup 1540/// may be popped with DeactivateCleanupBlock or PopCleanupBlock. 1541/// 1542/// \param elementType - the immediate element type of the array; 1543/// possibly still an array type 1544void CodeGenFunction::pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin, 1545 llvm::Value *arrayEndPointer, 1546 QualType elementType, 1547 Destroyer *destroyer) { 1548 pushFullExprCleanup<IrregularPartialArrayDestroy>(EHCleanup, 1549 arrayBegin, arrayEndPointer, 1550 elementType, destroyer); 1551} 1552 1553/// pushRegularPartialArrayCleanup - Push an EH cleanup to destroy 1554/// already-constructed elements of the given array. The cleanup 1555/// may be popped with DeactivateCleanupBlock or PopCleanupBlock. 1556/// 1557/// \param elementType - the immediate element type of the array; 1558/// possibly still an array type 1559void CodeGenFunction::pushRegularPartialArrayCleanup(llvm::Value *arrayBegin, 1560 llvm::Value *arrayEnd, 1561 QualType elementType, 1562 Destroyer *destroyer) { 1563 pushFullExprCleanup<RegularPartialArrayDestroy>(EHCleanup, 1564 arrayBegin, arrayEnd, 1565 elementType, destroyer); 1566} 1567 1568/// Lazily declare the @llvm.lifetime.start intrinsic. 1569llvm::Constant *CodeGenModule::getLLVMLifetimeStartFn() { 1570 if (LifetimeStartFn) return LifetimeStartFn; 1571 LifetimeStartFn = llvm::Intrinsic::getDeclaration(&getModule(), 1572 llvm::Intrinsic::lifetime_start); 1573 return LifetimeStartFn; 1574} 1575 1576/// Lazily declare the @llvm.lifetime.end intrinsic. 1577llvm::Constant *CodeGenModule::getLLVMLifetimeEndFn() { 1578 if (LifetimeEndFn) return LifetimeEndFn; 1579 LifetimeEndFn = llvm::Intrinsic::getDeclaration(&getModule(), 1580 llvm::Intrinsic::lifetime_end); 1581 return LifetimeEndFn; 1582} 1583 1584namespace { 1585 /// A cleanup to perform a release of an object at the end of a 1586 /// function. This is used to balance out the incoming +1 of a 1587 /// ns_consumed argument when we can't reasonably do that just by 1588 /// not doing the initial retain for a __block argument. 1589 struct ConsumeARCParameter : EHScopeStack::Cleanup { 1590 ConsumeARCParameter(llvm::Value *param, 1591 ARCPreciseLifetime_t precise) 1592 : Param(param), Precise(precise) {} 1593 1594 llvm::Value *Param; 1595 ARCPreciseLifetime_t Precise; 1596 1597 void Emit(CodeGenFunction &CGF, Flags flags) { 1598 CGF.EmitARCRelease(Param, Precise); 1599 } 1600 }; 1601} 1602 1603/// Emit an alloca (or GlobalValue depending on target) 1604/// for the specified parameter and set up LocalDeclMap. 1605void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg, 1606 unsigned ArgNo) { 1607 // FIXME: Why isn't ImplicitParamDecl a ParmVarDecl? 1608 assert((isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)) && 1609 "Invalid argument to EmitParmDecl"); 1610 1611 Arg->setName(D.getName()); 1612 1613 QualType Ty = D.getType(); 1614 1615 // Use better IR generation for certain implicit parameters. 1616 if (isa<ImplicitParamDecl>(D)) { 1617 // The only implicit argument a block has is its literal. 1618 if (BlockInfo) { 1619 LocalDeclMap[&D] = Arg; 1620 llvm::Value *LocalAddr = 0; 1621 if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1622 // Allocate a stack slot to let the debug info survive the RA. 1623 llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), 1624 D.getName() + ".addr"); 1625 Alloc->setAlignment(getContext().getDeclAlign(&D).getQuantity()); 1626 LValue lv = MakeAddrLValue(Alloc, Ty, getContext().getDeclAlign(&D)); 1627 EmitStoreOfScalar(Arg, lv, /* isInitialization */ true); 1628 LocalAddr = Builder.CreateLoad(Alloc); 1629 } 1630 1631 if (CGDebugInfo *DI = getDebugInfo()) { 1632 if (CGM.getCodeGenOpts().getDebugInfo() 1633 >= CodeGenOptions::LimitedDebugInfo) { 1634 DI->setLocation(D.getLocation()); 1635 DI->EmitDeclareOfBlockLiteralArgVariable(*BlockInfo, Arg, LocalAddr, Builder); 1636 } 1637 } 1638 1639 return; 1640 } 1641 } 1642 1643 llvm::Value *DeclPtr; 1644 bool HasNonScalarEvalKind = !CodeGenFunction::hasScalarEvaluationKind(Ty); 1645 // If this is an aggregate or variable sized value, reuse the input pointer. 1646 if (HasNonScalarEvalKind || !Ty->isConstantSizeType()) { 1647 DeclPtr = Arg; 1648 // Push a destructor cleanup for this parameter if the ABI requires it. 1649 if (HasNonScalarEvalKind && 1650 getTarget().getCXXABI().isArgumentDestroyedByCallee()) { 1651 if (const CXXRecordDecl *RD = Ty->getAsCXXRecordDecl()) { 1652 if (RD->hasNonTrivialDestructor()) 1653 pushDestroy(QualType::DK_cxx_destructor, DeclPtr, Ty); 1654 } 1655 } 1656 } else { 1657 // Otherwise, create a temporary to hold the value. 1658 llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), 1659 D.getName() + ".addr"); 1660 CharUnits Align = getContext().getDeclAlign(&D); 1661 Alloc->setAlignment(Align.getQuantity()); 1662 DeclPtr = Alloc; 1663 1664 bool doStore = true; 1665 1666 Qualifiers qs = Ty.getQualifiers(); 1667 LValue lv = MakeAddrLValue(DeclPtr, Ty, Align); 1668 if (Qualifiers::ObjCLifetime lt = qs.getObjCLifetime()) { 1669 // We honor __attribute__((ns_consumed)) for types with lifetime. 1670 // For __strong, it's handled by just skipping the initial retain; 1671 // otherwise we have to balance out the initial +1 with an extra 1672 // cleanup to do the release at the end of the function. 1673 bool isConsumed = D.hasAttr<NSConsumedAttr>(); 1674 1675 // 'self' is always formally __strong, but if this is not an 1676 // init method then we don't want to retain it. 1677 if (D.isARCPseudoStrong()) { 1678 const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CurCodeDecl); 1679 assert(&D == method->getSelfDecl()); 1680 assert(lt == Qualifiers::OCL_Strong); 1681 assert(qs.hasConst()); 1682 assert(method->getMethodFamily() != OMF_init); 1683 (void) method; 1684 lt = Qualifiers::OCL_ExplicitNone; 1685 } 1686 1687 if (lt == Qualifiers::OCL_Strong) { 1688 if (!isConsumed) { 1689 if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1690 // use objc_storeStrong(&dest, value) for retaining the 1691 // object. But first, store a null into 'dest' because 1692 // objc_storeStrong attempts to release its old value. 1693 llvm::Value *Null = CGM.EmitNullConstant(D.getType()); 1694 EmitStoreOfScalar(Null, lv, /* isInitialization */ true); 1695 EmitARCStoreStrongCall(lv.getAddress(), Arg, true); 1696 doStore = false; 1697 } 1698 else 1699 // Don't use objc_retainBlock for block pointers, because we 1700 // don't want to Block_copy something just because we got it 1701 // as a parameter. 1702 Arg = EmitARCRetainNonBlock(Arg); 1703 } 1704 } else { 1705 // Push the cleanup for a consumed parameter. 1706 if (isConsumed) { 1707 ARCPreciseLifetime_t precise = (D.hasAttr<ObjCPreciseLifetimeAttr>() 1708 ? ARCPreciseLifetime : ARCImpreciseLifetime); 1709 EHStack.pushCleanup<ConsumeARCParameter>(getARCCleanupKind(), Arg, 1710 precise); 1711 } 1712 1713 if (lt == Qualifiers::OCL_Weak) { 1714 EmitARCInitWeak(DeclPtr, Arg); 1715 doStore = false; // The weak init is a store, no need to do two. 1716 } 1717 } 1718 1719 // Enter the cleanup scope. 1720 EmitAutoVarWithLifetime(*this, D, DeclPtr, lt); 1721 } 1722 1723 // Store the initial value into the alloca. 1724 if (doStore) 1725 EmitStoreOfScalar(Arg, lv, /* isInitialization */ true); 1726 } 1727 1728 llvm::Value *&DMEntry = LocalDeclMap[&D]; 1729 assert(DMEntry == 0 && "Decl already exists in localdeclmap!"); 1730 DMEntry = DeclPtr; 1731 1732 // Emit debug info for param declaration. 1733 if (CGDebugInfo *DI = getDebugInfo()) { 1734 if (CGM.getCodeGenOpts().getDebugInfo() 1735 >= CodeGenOptions::LimitedDebugInfo) { 1736 DI->EmitDeclareOfArgVariable(&D, DeclPtr, ArgNo, Builder); 1737 } 1738 } 1739 1740 if (D.hasAttr<AnnotateAttr>()) 1741 EmitVarAnnotations(&D, DeclPtr); 1742} 1743