1//===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This contains code to emit Decl nodes as LLVM code.
10//
11//===----------------------------------------------------------------------===//
12
13#include "CGBlocks.h"
14#include "CGCXXABI.h"
15#include "CGCleanup.h"
16#include "CGDebugInfo.h"
17#include "CGOpenCLRuntime.h"
18#include "CGOpenMPRuntime.h"
19#include "CodeGenFunction.h"
20#include "CodeGenModule.h"
21#include "CodeGenPGO.h"
22#include "ConstantEmitter.h"
23#include "EHScopeStack.h"
24#include "PatternInit.h"
25#include "TargetInfo.h"
26#include "clang/AST/ASTContext.h"
27#include "clang/AST/Attr.h"
28#include "clang/AST/CharUnits.h"
29#include "clang/AST/Decl.h"
30#include "clang/AST/DeclObjC.h"
31#include "clang/AST/DeclOpenACC.h"
32#include "clang/AST/DeclOpenMP.h"
33#include "clang/Basic/CodeGenOptions.h"
34#include "clang/Basic/TargetInfo.h"
35#include "clang/CodeGen/CGFunctionInfo.h"
36#include "clang/Sema/Sema.h"
37#include "llvm/Analysis/ConstantFolding.h"
38#include "llvm/Analysis/ValueTracking.h"
39#include "llvm/IR/DataLayout.h"
40#include "llvm/IR/GlobalVariable.h"
41#include "llvm/IR/Instructions.h"
42#include "llvm/IR/Intrinsics.h"
43#include "llvm/IR/Type.h"
44#include <optional>
45
46using namespace clang;
47using namespace CodeGen;
48
49static_assert(clang::Sema::MaximumAlignment <= llvm::Value::MaximumAlignment,
50 "Clang max alignment greater than what LLVM supports?");
51
52void CodeGenFunction::EmitDecl(const Decl &D, bool EvaluateConditionDecl) {
53 switch (D.getKind()) {
54 case Decl::BuiltinTemplate:
55 case Decl::TranslationUnit:
56 case Decl::ExternCContext:
57 case Decl::Namespace:
58 case Decl::UnresolvedUsingTypename:
59 case Decl::ClassTemplateSpecialization:
60 case Decl::ClassTemplatePartialSpecialization:
61 case Decl::VarTemplateSpecialization:
62 case Decl::VarTemplatePartialSpecialization:
63 case Decl::TemplateTypeParm:
64 case Decl::UnresolvedUsingValue:
65 case Decl::NonTypeTemplateParm:
66 case Decl::CXXDeductionGuide:
67 case Decl::CXXMethod:
68 case Decl::CXXConstructor:
69 case Decl::CXXDestructor:
70 case Decl::CXXConversion:
71 case Decl::Field:
72 case Decl::MSProperty:
73 case Decl::IndirectField:
74 case Decl::ObjCIvar:
75 case Decl::ObjCAtDefsField:
76 case Decl::ParmVar:
77 case Decl::ImplicitParam:
78 case Decl::ClassTemplate:
79 case Decl::VarTemplate:
80 case Decl::FunctionTemplate:
81 case Decl::TypeAliasTemplate:
82 case Decl::TemplateTemplateParm:
83 case Decl::ObjCMethod:
84 case Decl::ObjCCategory:
85 case Decl::ObjCProtocol:
86 case Decl::ObjCInterface:
87 case Decl::ObjCCategoryImpl:
88 case Decl::ObjCImplementation:
89 case Decl::ObjCProperty:
90 case Decl::ObjCCompatibleAlias:
91 case Decl::PragmaComment:
92 case Decl::PragmaDetectMismatch:
93 case Decl::AccessSpec:
94 case Decl::LinkageSpec:
95 case Decl::Export:
96 case Decl::ObjCPropertyImpl:
97 case Decl::FileScopeAsm:
98 case Decl::TopLevelStmt:
99 case Decl::Friend:
100 case Decl::FriendTemplate:
101 case Decl::Block:
102 case Decl::OutlinedFunction:
103 case Decl::Captured:
104 case Decl::UsingShadow:
105 case Decl::ConstructorUsingShadow:
106 case Decl::ObjCTypeParam:
107 case Decl::Binding:
108 case Decl::UnresolvedUsingIfExists:
109 case Decl::HLSLBuffer:
110 case Decl::HLSLRootSignature:
111 llvm_unreachable("Declaration should not be in declstmts!");
112 case Decl::Record: // struct/union/class X;
113 case Decl::CXXRecord: // struct/union/class X; [C++]
114 if (CGDebugInfo *DI = getDebugInfo())
115 if (cast<RecordDecl>(Val: D).getDefinition())
116 DI->EmitAndRetainType(
117 Ty: getContext().getCanonicalTagType(TD: cast<RecordDecl>(Val: &D)));
118 return;
119 case Decl::Enum: // enum X;
120 if (CGDebugInfo *DI = getDebugInfo())
121 if (cast<EnumDecl>(Val: D).getDefinition())
122 DI->EmitAndRetainType(
123 Ty: getContext().getCanonicalTagType(TD: cast<EnumDecl>(Val: &D)));
124 return;
125 case Decl::Function: // void X();
126 case Decl::EnumConstant: // enum ? { X = ? }
127 case Decl::StaticAssert: // static_assert(X, ""); [C++0x]
128 case Decl::ExplicitInstantiation:
129 case Decl::Label: // __label__ x;
130 case Decl::Import:
131 case Decl::MSGuid: // __declspec(uuid("..."))
132 case Decl::UnnamedGlobalConstant:
133 case Decl::TemplateParamObject:
134 case Decl::OMPThreadPrivate:
135 case Decl::OMPGroupPrivate:
136 case Decl::OMPAllocate:
137 case Decl::OMPCapturedExpr:
138 case Decl::OMPRequires:
139 case Decl::Empty:
140 case Decl::Concept:
141 case Decl::ImplicitConceptSpecialization:
142 case Decl::LifetimeExtendedTemporary:
143 case Decl::RequiresExprBody:
144 // None of these decls require codegen support.
145 return;
146
147 case Decl::CXXExpansionStmt: {
148 const auto *ESD = cast<CXXExpansionStmtDecl>(Val: &D);
149 assert(ESD->getInstantiations() && "expansion statement not expanded?");
150 EmitStmt(S: ESD->getInstantiations());
151 return;
152 }
153
154 case Decl::NamespaceAlias:
155 if (CGDebugInfo *DI = getDebugInfo())
156 DI->EmitNamespaceAlias(NA: cast<NamespaceAliasDecl>(Val: D));
157 return;
158 case Decl::Using: // using X; [C++]
159 if (CGDebugInfo *DI = getDebugInfo())
160 DI->EmitUsingDecl(UD: cast<UsingDecl>(Val: D));
161 return;
162 case Decl::UsingEnum: // using enum X; [C++]
163 if (CGDebugInfo *DI = getDebugInfo())
164 DI->EmitUsingEnumDecl(UD: cast<UsingEnumDecl>(Val: D));
165 return;
166 case Decl::UsingPack:
167 for (auto *Using : cast<UsingPackDecl>(Val: D).expansions())
168 EmitDecl(D: *Using, /*EvaluateConditionDecl=*/EvaluateConditionDecl);
169 return;
170 case Decl::UsingDirective: // using namespace X; [C++]
171 if (CGDebugInfo *DI = getDebugInfo())
172 DI->EmitUsingDirective(UD: cast<UsingDirectiveDecl>(Val: D));
173 return;
174 case Decl::Var:
175 case Decl::Decomposition: {
176 const VarDecl &VD = cast<VarDecl>(Val: D);
177 assert(VD.isLocalVarDecl() &&
178 "Should not see file-scope variables inside a function!");
179 EmitVarDecl(D: VD);
180 if (EvaluateConditionDecl)
181 MaybeEmitDeferredVarDeclInit(var: &VD);
182
183 return;
184 }
185
186 case Decl::OMPDeclareReduction:
187 return CGM.EmitOMPDeclareReduction(D: cast<OMPDeclareReductionDecl>(Val: &D), CGF: this);
188
189 case Decl::OMPDeclareMapper:
190 return CGM.EmitOMPDeclareMapper(D: cast<OMPDeclareMapperDecl>(Val: &D), CGF: this);
191
192 case Decl::OpenACCDeclare:
193 return CGM.EmitOpenACCDeclare(D: cast<OpenACCDeclareDecl>(Val: &D), CGF: this);
194 case Decl::OpenACCRoutine:
195 return CGM.EmitOpenACCRoutine(D: cast<OpenACCRoutineDecl>(Val: &D), CGF: this);
196
197 case Decl::Typedef: // typedef int X;
198 case Decl::TypeAlias: { // using X = int; [C++0x]
199 QualType Ty = cast<TypedefNameDecl>(Val: D).getUnderlyingType();
200 if (CGDebugInfo *DI = getDebugInfo())
201 DI->EmitAndRetainType(Ty);
202 if (Ty->isVariablyModifiedType())
203 EmitVariablyModifiedType(Ty);
204 return;
205 }
206 }
207}
208
209/// EmitVarDecl - This method handles emission of any variable declaration
210/// inside a function, including static vars etc.
211void CodeGenFunction::EmitVarDecl(const VarDecl &D) {
212 if (D.hasExternalStorage())
213 // Don't emit it now, allow it to be emitted lazily on its first use.
214 return;
215
216 // Some function-scope variable does not have static storage but still
217 // needs to be emitted like a static variable, e.g. a function-scope
218 // variable in constant address space in OpenCL.
219 if (D.getStorageDuration() != SD_Automatic) {
220 // Static sampler variables translated to function calls.
221 if (D.getType()->isSamplerT())
222 return;
223
224 llvm::GlobalValue::LinkageTypes Linkage =
225 CGM.getLLVMLinkageVarDefinition(VD: &D);
226
227 // FIXME: We need to force the emission/use of a guard variable for
228 // some variables even if we can constant-evaluate them because
229 // we can't guarantee every translation unit will constant-evaluate them.
230
231 return EmitStaticVarDecl(D, Linkage);
232 }
233
234 if (D.getType().getAddressSpace() == LangAS::opencl_local)
235 return CGM.getOpenCLRuntime().EmitWorkGroupLocalVarDecl(CGF&: *this, D);
236
237 assert(D.hasLocalStorage());
238 return EmitAutoVarDecl(D);
239}
240
241static std::string getStaticDeclName(CodeGenModule &CGM, const VarDecl &D) {
242 if (CGM.getLangOpts().CPlusPlus)
243 return CGM.getMangledName(GD: &D).str();
244
245 // If this isn't C++, we don't need a mangled name, just a pretty one.
246 assert(!D.isExternallyVisible() && "name shouldn't matter");
247 std::string ContextName;
248 const DeclContext *DC = D.getDeclContext();
249 if (auto *CD = dyn_cast<CapturedDecl>(Val: DC))
250 DC = cast<DeclContext>(Val: CD->getNonClosureContext());
251 if (const auto *FD = dyn_cast<FunctionDecl>(Val: DC))
252 ContextName = std::string(CGM.getMangledName(GD: FD));
253 else if (const auto *BD = dyn_cast<BlockDecl>(Val: DC))
254 ContextName = std::string(CGM.getBlockMangledName(GD: GlobalDecl(), BD));
255 else if (const auto *OMD = dyn_cast<ObjCMethodDecl>(Val: DC))
256 ContextName = OMD->getSelector().getAsString();
257 else
258 llvm_unreachable("Unknown context for static var decl");
259
260 ContextName += "." + D.getNameAsString();
261 return ContextName;
262}
263
264llvm::Constant *CodeGenModule::getOrCreateStaticVarDecl(
265 const VarDecl &D, llvm::GlobalValue::LinkageTypes Linkage) {
266 // In general, we don't always emit static var decls once before we reference
267 // them. It is possible to reference them before emitting the function that
268 // contains them, and it is possible to emit the containing function multiple
269 // times.
270 if (llvm::Constant *ExistingGV = StaticLocalDeclMap[&D])
271 return ExistingGV;
272
273 QualType Ty = D.getType();
274 assert(Ty->isConstantSizeType() && "VLAs can't be static");
275
276 // Use the label if the variable is renamed with the asm-label extension.
277 std::string Name;
278 if (D.hasAttr<AsmLabelAttr>())
279 Name = std::string(getMangledName(GD: &D));
280 else
281 Name = getStaticDeclName(CGM&: *this, D);
282
283 llvm::Type *LTy = getTypes().ConvertTypeForMem(T: Ty);
284 LangAS AS = GetGlobalVarAddressSpace(D: &D);
285 unsigned TargetAS = getContext().getTargetAddressSpace(AS);
286
287 // OpenCL variables in local address space and CUDA shared
288 // variables cannot have an initializer.
289 llvm::Constant *Init = nullptr;
290 if (Ty.getAddressSpace() == LangAS::opencl_local ||
291 D.hasAttr<CUDASharedAttr>() || D.hasAttr<LoaderUninitializedAttr>())
292 Init = llvm::UndefValue::get(T: LTy);
293 else
294 Init = EmitNullConstant(T: Ty);
295
296 llvm::GlobalVariable *GV = new llvm::GlobalVariable(
297 getModule(), LTy, Ty.isConstant(Ctx: getContext()), Linkage, Init, Name,
298 nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
299 GV->setAlignment(getContext().getDeclAlign(D: &D).getAsAlign());
300
301 if (supportsCOMDAT() && GV->isWeakForLinker())
302 GV->setComdat(TheModule.getOrInsertComdat(Name: GV->getName()));
303
304 if (D.getTLSKind())
305 setTLSMode(GV, D);
306
307 setGVProperties(GV, D: &D);
308 getTargetCodeGenInfo().setTargetAttributes(D: cast<Decl>(Val: &D), GV, M&: *this);
309
310 // Make sure the result is of the correct type.
311 LangAS ExpectedAS = Ty.getAddressSpace();
312 llvm::Constant *Addr = GV;
313 if (AS != ExpectedAS) {
314 Addr = performAddrSpaceCast(
315 Src: GV,
316 DestTy: llvm::PointerType::get(C&: getLLVMContext(),
317 AddressSpace: getContext().getTargetAddressSpace(AS: ExpectedAS)));
318 }
319
320 setStaticLocalDeclAddress(D: &D, C: Addr);
321
322 // Ensure that the static local gets initialized by making sure the parent
323 // function gets emitted eventually.
324 const Decl *DC = cast<Decl>(Val: D.getDeclContext());
325
326 // We can't name blocks or captured statements directly, so try to emit their
327 // parents.
328 if (isa<BlockDecl>(Val: DC) || isa<CapturedDecl>(Val: DC)) {
329 DC = DC->getNonClosureContext();
330 // FIXME: Ensure that global blocks get emitted.
331 if (!DC)
332 return Addr;
333 }
334
335 GlobalDecl GD;
336 if (const auto *CD = dyn_cast<CXXConstructorDecl>(Val: DC))
337 GD = GlobalDecl(CD, Ctor_Base);
338 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(Val: DC))
339 GD = GlobalDecl(DD, Dtor_Base);
340 else if (const auto *FD = dyn_cast<FunctionDecl>(Val: DC))
341 GD = GlobalDecl(FD);
342 else {
343 // Don't do anything for Obj-C method decls or global closures. We should
344 // never defer them.
345 assert(isa<ObjCMethodDecl>(DC) && "unexpected parent code decl");
346 }
347 if (GD.getDecl()) {
348 // Disable emission of the parent function for the OpenMP device codegen.
349 CGOpenMPRuntime::DisableAutoDeclareTargetRAII NoDeclTarget(*this);
350 (void)GetAddrOfGlobal(GD);
351 }
352
353 return Addr;
354}
355
356/// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
357/// global variable that has already been created for it. If the initializer
358/// has a different type than GV does, this may free GV and return a different
359/// one. Otherwise it just returns GV.
360llvm::GlobalVariable *
361CodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D,
362 llvm::GlobalVariable *GV) {
363 ConstantEmitter emitter(*this);
364 llvm::Constant *Init = emitter.tryEmitForInitializer(D);
365
366 // If constant emission failed, then this should be a C++ static
367 // initializer.
368 if (!Init) {
369 if (!getLangOpts().CPlusPlus)
370 CGM.ErrorUnsupported(S: D.getInit(), Type: "constant l-value expression");
371 else if (D.hasFlexibleArrayInit(Ctx: getContext()))
372 CGM.ErrorUnsupported(S: D.getInit(), Type: "flexible array initializer");
373 else if (HaveInsertPoint()) {
374 // Since we have a static initializer, this global variable can't
375 // be constant.
376 GV->setConstant(false);
377
378 EmitCXXGuardedInit(D, DeclPtr: GV, /*PerformInit*/true);
379 }
380 return GV;
381 }
382
383 PGO->markStmtMaybeUsed(S: D.getInit()); // FIXME: Too lazy
384
385#ifndef NDEBUG
386 CharUnits VarSize = CGM.getContext().getTypeSizeInChars(D.getType()) +
387 D.getFlexibleArrayInitChars(getContext());
388 CharUnits CstSize = CharUnits::fromQuantity(
389 CGM.getDataLayout().getTypeAllocSize(Init->getType()));
390 assert(VarSize == CstSize && "Emitted constant has unexpected size");
391#endif
392
393 bool NeedsDtor =
394 D.needsDestruction(Ctx: getContext()) == QualType::DK_cxx_destructor;
395
396 GV->setConstant(
397 D.getType().isConstantStorage(Ctx: getContext(), ExcludeCtor: true, ExcludeDtor: !NeedsDtor));
398 GV->replaceInitializer(InitVal: Init);
399
400 emitter.finalize(global: GV);
401
402 if (NeedsDtor && HaveInsertPoint()) {
403 // We have a constant initializer, but a nontrivial destructor. We still
404 // need to perform a guarded "initialization" in order to register the
405 // destructor.
406 EmitCXXGuardedInit(D, DeclPtr: GV, /*PerformInit*/false);
407 }
408
409 return GV;
410}
411
412void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
413 llvm::GlobalValue::LinkageTypes Linkage) {
414 // Check to see if we already have a global variable for this
415 // declaration. This can happen when double-emitting function
416 // bodies, e.g. with complete and base constructors.
417 llvm::Constant *addr = CGM.getOrCreateStaticVarDecl(D, Linkage);
418 CharUnits alignment = getContext().getDeclAlign(D: &D);
419
420 // Store into LocalDeclMap before generating initializer to handle
421 // circular references.
422 llvm::Type *elemTy = ConvertTypeForMem(T: D.getType());
423 setAddrOfLocalVar(VD: &D, Addr: Address(addr, elemTy, alignment));
424
425 // We can't have a VLA here, but we can have a pointer to a VLA,
426 // even though that doesn't really make any sense.
427 // Make sure to evaluate VLA bounds now so that we have them for later.
428 if (D.getType()->isVariablyModifiedType())
429 EmitVariablyModifiedType(Ty: D.getType());
430
431 // Save the type in case adding the initializer forces a type change.
432 llvm::Type *expectedType = addr->getType();
433
434 llvm::GlobalVariable *var =
435 cast<llvm::GlobalVariable>(Val: addr->stripPointerCasts());
436
437 // CUDA's local and local static __shared__ variables should not
438 // have any non-empty initializers. This is ensured by Sema.
439 // Whatever initializer such variable may have when it gets here is
440 // a no-op and should not be emitted.
441 bool isCudaSharedVar = getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
442 D.hasAttr<CUDASharedAttr>();
443 // If this value has an initializer, emit it.
444 if (D.getInit() && !isCudaSharedVar) {
445 ApplyAtomGroup Grp(getDebugInfo());
446 var = AddInitializerToStaticVarDecl(D, GV: var);
447 }
448
449 var->setAlignment(alignment.getAsAlign());
450
451 if (D.hasAttr<AnnotateAttr>())
452 CGM.AddGlobalAnnotations(D: &D, GV: var);
453
454 if (auto *SA = D.getAttr<PragmaClangBSSSectionAttr>())
455 var->addAttribute(Kind: "bss-section", Val: SA->getName());
456 if (auto *SA = D.getAttr<PragmaClangDataSectionAttr>())
457 var->addAttribute(Kind: "data-section", Val: SA->getName());
458 if (auto *SA = D.getAttr<PragmaClangRodataSectionAttr>())
459 var->addAttribute(Kind: "rodata-section", Val: SA->getName());
460 if (auto *SA = D.getAttr<PragmaClangRelroSectionAttr>())
461 var->addAttribute(Kind: "relro-section", Val: SA->getName());
462
463 if (const SectionAttr *SA = D.getAttr<SectionAttr>())
464 var->setSection(SA->getName());
465
466 if (D.hasAttr<RetainAttr>())
467 CGM.addUsedGlobal(GV: var);
468 else if (D.hasAttr<UsedAttr>())
469 CGM.addUsedOrCompilerUsedGlobal(GV: var);
470
471 if (CGM.getCodeGenOpts().KeepPersistentStorageVariables)
472 CGM.addUsedOrCompilerUsedGlobal(GV: var);
473
474 // We may have to cast the constant because of the initializer
475 // mismatch above.
476 //
477 // FIXME: It is really dangerous to store this in the map; if anyone
478 // RAUW's the GV uses of this constant will be invalid.
479 llvm::Constant *castedAddr =
480 llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(C: var, Ty: expectedType);
481 LocalDeclMap.find(Val: &D)->second = Address(castedAddr, elemTy, alignment);
482 CGM.setStaticLocalDeclAddress(D: &D, C: castedAddr);
483
484 CGM.getSanitizerMetadata()->reportGlobal(GV: var, D);
485
486 // Emit global variable debug descriptor for static vars.
487 CGDebugInfo *DI = getDebugInfo();
488 if (DI && CGM.getCodeGenOpts().hasReducedDebugInfo()) {
489 DI->setLocation(D.getLocation());
490 DI->EmitGlobalVariable(GV: var, Decl: &D);
491 }
492}
493
494namespace {
495 struct DestroyObject final : EHScopeStack::Cleanup {
496 DestroyObject(Address addr, QualType type,
497 CodeGenFunction::Destroyer *destroyer,
498 bool useEHCleanupForArray)
499 : addr(addr), type(type), destroyer(destroyer),
500 useEHCleanupForArray(useEHCleanupForArray) {}
501
502 Address addr;
503 QualType type;
504 CodeGenFunction::Destroyer *destroyer;
505 bool useEHCleanupForArray;
506
507 void Emit(CodeGenFunction &CGF, Flags flags) override {
508 // Don't use an EH cleanup recursively from an EH cleanup.
509 bool useEHCleanupForArray =
510 flags.isForNormalCleanup() && this->useEHCleanupForArray;
511
512 CGF.emitDestroy(addr, type, destroyer, useEHCleanupForArray);
513 }
514 };
515
516 template <class Derived>
517 struct DestroyNRVOVariable : EHScopeStack::Cleanup {
518 DestroyNRVOVariable(Address addr, QualType type, llvm::Value *NRVOFlag)
519 : NRVOFlag(NRVOFlag), Loc(addr), Ty(type) {}
520
521 llvm::Value *NRVOFlag;
522 Address Loc;
523 QualType Ty;
524
525 void Emit(CodeGenFunction &CGF, Flags flags) override {
526 // Along the exceptions path we always execute the dtor.
527 bool NRVO = flags.isForNormalCleanup() && NRVOFlag;
528
529 llvm::BasicBlock *SkipDtorBB = nullptr;
530 if (NRVO) {
531 // If we exited via NRVO, we skip the destructor call.
532 llvm::BasicBlock *RunDtorBB = CGF.createBasicBlock(name: "nrvo.unused");
533 SkipDtorBB = CGF.createBasicBlock(name: "nrvo.skipdtor");
534 llvm::Value *DidNRVO =
535 CGF.Builder.CreateFlagLoad(Addr: NRVOFlag, Name: "nrvo.val");
536 CGF.Builder.CreateCondBr(Cond: DidNRVO, True: SkipDtorBB, False: RunDtorBB);
537 CGF.EmitBlock(BB: RunDtorBB);
538 }
539
540 static_cast<Derived *>(this)->emitDestructorCall(CGF);
541
542 if (NRVO) CGF.EmitBlock(BB: SkipDtorBB);
543 }
544
545 virtual ~DestroyNRVOVariable() = default;
546 };
547
548 struct DestroyNRVOVariableCXX final
549 : DestroyNRVOVariable<DestroyNRVOVariableCXX> {
550 DestroyNRVOVariableCXX(Address addr, QualType type,
551 const CXXDestructorDecl *Dtor, llvm::Value *NRVOFlag)
552 : DestroyNRVOVariable<DestroyNRVOVariableCXX>(addr, type, NRVOFlag),
553 Dtor(Dtor) {}
554
555 const CXXDestructorDecl *Dtor;
556
557 void emitDestructorCall(CodeGenFunction &CGF) {
558 CGF.EmitCXXDestructorCall(D: Dtor, Type: Dtor_Complete,
559 /*ForVirtualBase=*/false,
560 /*Delegating=*/false, This: Loc, ThisTy: Ty);
561 }
562 };
563
564 struct DestroyNRVOVariableC final
565 : DestroyNRVOVariable<DestroyNRVOVariableC> {
566 DestroyNRVOVariableC(Address addr, llvm::Value *NRVOFlag, QualType Ty)
567 : DestroyNRVOVariable<DestroyNRVOVariableC>(addr, Ty, NRVOFlag) {}
568
569 void emitDestructorCall(CodeGenFunction &CGF) {
570 CGF.destroyNonTrivialCStruct(CGF, Loc, Ty);
571 }
572 };
573
574 struct CallStackRestore final : EHScopeStack::Cleanup {
575 Address Stack;
576 CallStackRestore(Address Stack) : Stack(Stack) {}
577 void Emit(CodeGenFunction &CGF, Flags flags) override {
578 llvm::Value *V = CGF.Builder.CreateLoad(Addr: Stack);
579 CGF.Builder.CreateStackRestore(Ptr: V);
580 }
581 };
582
583 struct KmpcAllocFree final : EHScopeStack::Cleanup {
584 std::pair<llvm::Value *, llvm::Value *> AddrSizePair;
585 KmpcAllocFree(const std::pair<llvm::Value *, llvm::Value *> &AddrSizePair)
586 : AddrSizePair(AddrSizePair) {}
587 void Emit(CodeGenFunction &CGF, Flags EmissionFlags) override {
588 auto &RT = CGF.CGM.getOpenMPRuntime();
589 RT.getKmpcFreeShared(CGF, AddrSizePair);
590 }
591 };
592
593 struct ExtendGCLifetime final : EHScopeStack::Cleanup {
594 const VarDecl &Var;
595 ExtendGCLifetime(const VarDecl *var) : Var(*var) {}
596
597 void Emit(CodeGenFunction &CGF, Flags flags) override {
598 // Compute the address of the local variable, in case it's a
599 // byref or something.
600 DeclRefExpr DRE(CGF.getContext(), const_cast<VarDecl *>(&Var), false,
601 Var.getType(), VK_LValue, SourceLocation());
602 llvm::Value *value = CGF.EmitLoadOfScalar(lvalue: CGF.EmitDeclRefLValue(E: &DRE),
603 Loc: SourceLocation());
604 CGF.EmitExtendGCLifetime(object: value);
605 }
606 };
607
608 struct CallCleanupFunction final : EHScopeStack::Cleanup {
609 llvm::Constant *CleanupFn;
610 const CGFunctionInfo &FnInfo;
611 const VarDecl &Var;
612 const CleanupAttr *Attribute;
613
614 CallCleanupFunction(llvm::Constant *CleanupFn, const CGFunctionInfo *Info,
615 const VarDecl *Var, const CleanupAttr *Attr)
616 : CleanupFn(CleanupFn), FnInfo(*Info), Var(*Var), Attribute(Attr) {}
617
618 void Emit(CodeGenFunction &CGF, Flags flags) override {
619 DeclRefExpr DRE(CGF.getContext(), const_cast<VarDecl *>(&Var), false,
620 Var.getType(), VK_LValue, SourceLocation());
621 // Compute the address of the local variable, in case it's a byref
622 // or something.
623 llvm::Value *Addr = CGF.EmitDeclRefLValue(E: &DRE).getPointer(CGF);
624
625 // In some cases, the type of the function argument will be different from
626 // the type of the pointer. An example of this is
627 // void f(void* arg);
628 // __attribute__((cleanup(f))) void *g;
629 //
630 // To fix this we insert a bitcast here.
631 QualType ArgTy = FnInfo.arg_begin()->type;
632 llvm::Value *Arg =
633 CGF.Builder.CreateBitCast(V: Addr, DestTy: CGF.ConvertType(T: ArgTy));
634
635 CallArgList Args;
636 Args.add(rvalue: RValue::get(V: Arg),
637 type: CGF.getContext().getPointerType(T: Var.getType()));
638 GlobalDecl GD = GlobalDecl(Attribute->getFunctionDecl());
639 auto Callee = CGCallee::forDirect(functionPtr: CleanupFn, abstractInfo: CGCalleeInfo(GD));
640 CGF.EmitCall(CallInfo: FnInfo, Callee, ReturnValue: ReturnValueSlot(), Args,
641 /*callOrInvoke*/ CallOrInvoke: nullptr, /*IsMustTail*/ false,
642 Loc: Attribute->getLoc());
643 }
644 };
645} // end anonymous namespace
646
647/// EmitAutoVarWithLifetime - Does the setup required for an automatic
648/// variable with lifetime.
649static void EmitAutoVarWithLifetime(CodeGenFunction &CGF, const VarDecl &var,
650 Address addr,
651 Qualifiers::ObjCLifetime lifetime) {
652 switch (lifetime) {
653 case Qualifiers::OCL_None:
654 llvm_unreachable("present but none");
655
656 case Qualifiers::OCL_ExplicitNone:
657 // nothing to do
658 break;
659
660 case Qualifiers::OCL_Strong: {
661 CodeGenFunction::Destroyer *destroyer =
662 (var.hasAttr<ObjCPreciseLifetimeAttr>()
663 ? CodeGenFunction::destroyARCStrongPrecise
664 : CodeGenFunction::destroyARCStrongImprecise);
665
666 CleanupKind cleanupKind = CGF.getARCCleanupKind();
667 CGF.pushDestroy(kind: cleanupKind, addr, type: var.getType(), destroyer,
668 useEHCleanupForArray: cleanupKind & EHCleanup);
669 break;
670 }
671 case Qualifiers::OCL_Autoreleasing:
672 // nothing to do
673 break;
674
675 case Qualifiers::OCL_Weak:
676 // __weak objects always get EH cleanups; otherwise, exceptions
677 // could cause really nasty crashes instead of mere leaks.
678 CGF.pushDestroy(kind: NormalAndEHCleanup, addr, type: var.getType(),
679 destroyer: CodeGenFunction::destroyARCWeak,
680 /*useEHCleanup*/ useEHCleanupForArray: true);
681 break;
682 }
683}
684
685static bool isAccessedBy(const VarDecl &var, const Stmt *s) {
686 if (const Expr *e = dyn_cast<Expr>(Val: s)) {
687 // Skip the most common kinds of expressions that make
688 // hierarchy-walking expensive.
689 s = e = e->IgnoreParenCasts();
690
691 if (const DeclRefExpr *ref = dyn_cast<DeclRefExpr>(Val: e))
692 return (ref->getDecl() == &var);
693 if (const BlockExpr *be = dyn_cast<BlockExpr>(Val: e)) {
694 const BlockDecl *block = be->getBlockDecl();
695 for (const auto &I : block->captures()) {
696 if (I.getVariable() == &var)
697 return true;
698 }
699 }
700 }
701
702 for (const Stmt *SubStmt : s->children())
703 // SubStmt might be null; as in missing decl or conditional of an if-stmt.
704 if (SubStmt && isAccessedBy(var, s: SubStmt))
705 return true;
706
707 return false;
708}
709
710static bool isAccessedBy(const ValueDecl *decl, const Expr *e) {
711 if (!decl) return false;
712 if (!isa<VarDecl>(Val: decl)) return false;
713 const VarDecl *var = cast<VarDecl>(Val: decl);
714 return isAccessedBy(var: *var, s: e);
715}
716
717static bool tryEmitARCCopyWeakInit(CodeGenFunction &CGF,
718 const LValue &destLV, const Expr *init) {
719 bool needsCast = false;
720
721 while (auto castExpr = dyn_cast<CastExpr>(Val: init->IgnoreParens())) {
722 switch (castExpr->getCastKind()) {
723 // Look through casts that don't require representation changes.
724 case CK_NoOp:
725 case CK_BitCast:
726 case CK_BlockPointerToObjCPointerCast:
727 needsCast = true;
728 break;
729
730 // If we find an l-value to r-value cast from a __weak variable,
731 // emit this operation as a copy or move.
732 case CK_LValueToRValue: {
733 const Expr *srcExpr = castExpr->getSubExpr();
734 if (srcExpr->getType().getObjCLifetime() != Qualifiers::OCL_Weak)
735 return false;
736
737 // Emit the source l-value.
738 LValue srcLV = CGF.EmitLValue(E: srcExpr);
739
740 // Handle a formal type change to avoid asserting.
741 auto srcAddr = srcLV.getAddress();
742 if (needsCast) {
743 srcAddr = srcAddr.withElementType(ElemTy: destLV.getAddress().getElementType());
744 }
745
746 // If it was an l-value, use objc_copyWeak.
747 if (srcExpr->isLValue()) {
748 CGF.EmitARCCopyWeak(dst: destLV.getAddress(), src: srcAddr);
749 } else {
750 assert(srcExpr->isXValue());
751 CGF.EmitARCMoveWeak(dst: destLV.getAddress(), src: srcAddr);
752 }
753 return true;
754 }
755
756 // Stop at anything else.
757 default:
758 return false;
759 }
760
761 init = castExpr->getSubExpr();
762 }
763 return false;
764}
765
766static void drillIntoBlockVariable(CodeGenFunction &CGF,
767 LValue &lvalue,
768 const VarDecl *var) {
769 lvalue.setAddress(CGF.emitBlockByrefAddress(baseAddr: lvalue.getAddress(), V: var));
770}
771
772void CodeGenFunction::EmitNullabilityCheck(LValue LHS, llvm::Value *RHS,
773 SourceLocation Loc) {
774 if (!SanOpts.has(K: SanitizerKind::NullabilityAssign))
775 return;
776
777 auto Nullability = LHS.getType()->getNullability();
778 if (!Nullability || *Nullability != NullabilityKind::NonNull)
779 return;
780
781 // Check if the right hand side of the assignment is nonnull, if the left
782 // hand side must be nonnull.
783 auto CheckOrdinal = SanitizerKind::SO_NullabilityAssign;
784 auto CheckHandler = SanitizerHandler::TypeMismatch;
785 SanitizerDebugLocation SanScope(this, {CheckOrdinal}, CheckHandler);
786 llvm::Value *IsNotNull;
787 if (auto *MPT = LHS.getType()->getAs<MemberPointerType>())
788 IsNotNull = CGM.getCXXABI().EmitMemberPointerIsNotNull(CGF&: *this, MemPtr: RHS, MPT);
789 else
790 IsNotNull = Builder.CreateIsNotNull(Arg: RHS);
791
792 llvm::Constant *StaticData[] = {
793 EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(T: LHS.getType()),
794 llvm::ConstantInt::get(Ty: Int8Ty, V: 0), // The LogAlignment info is unused.
795 llvm::ConstantInt::get(Ty: Int8Ty, V: TCK_NonnullAssign)};
796 EmitCheck(Checked: {{IsNotNull, CheckOrdinal}}, Check: CheckHandler, StaticArgs: StaticData, DynamicArgs: RHS);
797}
798
799void CodeGenFunction::EmitScalarInit(const Expr *init, const ValueDecl *D,
800 LValue lvalue, bool capturedByInit) {
801 Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
802 if (!lifetime) {
803 llvm::Value *Value;
804 if (PointerAuthQualifier PtrAuth = lvalue.getQuals().getPointerAuth()) {
805 Value = EmitPointerAuthQualify(Qualifier: PtrAuth, PointerExpr: init, StorageAddress: lvalue.getAddress());
806 lvalue.getQuals().removePointerAuth();
807 } else {
808 Value = EmitScalarExpr(E: init);
809 }
810 if (capturedByInit)
811 drillIntoBlockVariable(CGF&: *this, lvalue, var: cast<VarDecl>(Val: D));
812 EmitNullabilityCheck(LHS: lvalue, RHS: Value, Loc: init->getExprLoc());
813 EmitStoreThroughLValue(Src: RValue::get(V: Value), Dst: lvalue, isInit: true);
814 return;
815 }
816
817 if (const CXXDefaultInitExpr *DIE = dyn_cast<CXXDefaultInitExpr>(Val: init))
818 init = DIE->getExpr();
819
820 // If we're emitting a value with lifetime, we have to do the
821 // initialization *before* we leave the cleanup scopes.
822 if (auto *EWC = dyn_cast<ExprWithCleanups>(Val: init)) {
823 CodeGenFunction::RunCleanupsScope Scope(*this);
824 return EmitScalarInit(init: EWC->getSubExpr(), D, lvalue, capturedByInit);
825 }
826
827 // We have to maintain the illusion that the variable is
828 // zero-initialized. If the variable might be accessed in its
829 // initializer, zero-initialize before running the initializer, then
830 // actually perform the initialization with an assign.
831 bool accessedByInit = false;
832 if (lifetime != Qualifiers::OCL_ExplicitNone)
833 accessedByInit = (capturedByInit || isAccessedBy(decl: D, e: init));
834 if (accessedByInit) {
835 LValue tempLV = lvalue;
836 // Drill down to the __block object if necessary.
837 if (capturedByInit) {
838 // We can use a simple GEP for this because it can't have been
839 // moved yet.
840 tempLV.setAddress(emitBlockByrefAddress(baseAddr: tempLV.getAddress(),
841 V: cast<VarDecl>(Val: D),
842 /*follow*/ followForward: false));
843 }
844
845 auto ty = cast<llvm::PointerType>(Val: tempLV.getAddress().getElementType());
846 llvm::Value *zero = CGM.getNullPointer(T: ty, QT: tempLV.getType());
847
848 // If __weak, we want to use a barrier under certain conditions.
849 if (lifetime == Qualifiers::OCL_Weak)
850 EmitARCInitWeak(addr: tempLV.getAddress(), value: zero);
851
852 // Otherwise just do a simple store.
853 else
854 EmitStoreOfScalar(value: zero, lvalue: tempLV, /* isInitialization */ isInit: true);
855 }
856
857 // Emit the initializer.
858 llvm::Value *value = nullptr;
859
860 switch (lifetime) {
861 case Qualifiers::OCL_None:
862 llvm_unreachable("present but none");
863
864 case Qualifiers::OCL_Strong: {
865 if (!D || !isa<VarDecl>(Val: D) || !cast<VarDecl>(Val: D)->isARCPseudoStrong()) {
866 value = EmitARCRetainScalarExpr(expr: init);
867 break;
868 }
869 // If D is pseudo-strong, treat it like __unsafe_unretained here. This means
870 // that we omit the retain, and causes non-autoreleased return values to be
871 // immediately released.
872 [[fallthrough]];
873 }
874
875 case Qualifiers::OCL_ExplicitNone:
876 value = EmitARCUnsafeUnretainedScalarExpr(expr: init);
877 break;
878
879 case Qualifiers::OCL_Weak: {
880 // If it's not accessed by the initializer, try to emit the
881 // initialization with a copy or move.
882 if (!accessedByInit && tryEmitARCCopyWeakInit(CGF&: *this, destLV: lvalue, init)) {
883 return;
884 }
885
886 // No way to optimize a producing initializer into this. It's not
887 // worth optimizing for, because the value will immediately
888 // disappear in the common case.
889 value = EmitScalarExpr(E: init);
890
891 if (capturedByInit) drillIntoBlockVariable(CGF&: *this, lvalue, var: cast<VarDecl>(Val: D));
892 if (accessedByInit)
893 EmitARCStoreWeak(addr: lvalue.getAddress(), value, /*ignored*/ true);
894 else
895 EmitARCInitWeak(addr: lvalue.getAddress(), value);
896 return;
897 }
898
899 case Qualifiers::OCL_Autoreleasing:
900 value = EmitARCRetainAutoreleaseScalarExpr(expr: init);
901 break;
902 }
903
904 if (capturedByInit) drillIntoBlockVariable(CGF&: *this, lvalue, var: cast<VarDecl>(Val: D));
905
906 EmitNullabilityCheck(LHS: lvalue, RHS: value, Loc: init->getExprLoc());
907
908 // If the variable might have been accessed by its initializer, we
909 // might have to initialize with a barrier. We have to do this for
910 // both __weak and __strong, but __weak got filtered out above.
911 if (accessedByInit && lifetime == Qualifiers::OCL_Strong) {
912 llvm::Value *oldValue = EmitLoadOfScalar(lvalue, Loc: init->getExprLoc());
913 EmitStoreOfScalar(value, lvalue, /* isInitialization */ isInit: true);
914 EmitARCRelease(value: oldValue, precise: ARCImpreciseLifetime);
915 return;
916 }
917
918 EmitStoreOfScalar(value, lvalue, /* isInitialization */ isInit: true);
919}
920
921/// Decide whether we can emit the non-zero parts of the specified initializer
922/// with equal or fewer than NumStores scalar stores.
923static bool canEmitInitWithFewStoresAfterBZero(llvm::Constant *Init,
924 unsigned &NumStores) {
925 // Zero and Undef never requires any extra stores.
926 if (isa<llvm::ConstantAggregateZero>(Val: Init) ||
927 isa<llvm::ConstantPointerNull>(Val: Init) ||
928 isa<llvm::UndefValue>(Val: Init))
929 return true;
930 if (isa<llvm::ConstantInt>(Val: Init) || isa<llvm::ConstantFP>(Val: Init) ||
931 isa<llvm::ConstantVector>(Val: Init) || isa<llvm::BlockAddress>(Val: Init) ||
932 isa<llvm::ConstantExpr>(Val: Init))
933 return Init->isNullValue() || NumStores--;
934
935 // See if we can emit each element.
936 if (isa<llvm::ConstantArray>(Val: Init) || isa<llvm::ConstantStruct>(Val: Init)) {
937 for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
938 llvm::Constant *Elt = cast<llvm::Constant>(Val: Init->getOperand(i));
939 if (!canEmitInitWithFewStoresAfterBZero(Init: Elt, NumStores))
940 return false;
941 }
942 return true;
943 }
944
945 if (llvm::ConstantDataSequential *CDS =
946 dyn_cast<llvm::ConstantDataSequential>(Val: Init)) {
947 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
948 llvm::Constant *Elt = CDS->getElementAsConstant(i);
949 if (!canEmitInitWithFewStoresAfterBZero(Init: Elt, NumStores))
950 return false;
951 }
952 return true;
953 }
954
955 // Anything else is hard and scary.
956 return false;
957}
958
959/// For inits that canEmitInitWithFewStoresAfterBZero returned true for, emit
960/// the scalar stores that would be required.
961void CodeGenFunction::emitStoresForInitAfterBZero(llvm::Constant *Init,
962 Address Loc, bool isVolatile,
963 bool IsAutoInit) {
964 assert(!Init->isNullValue() && !isa<llvm::UndefValue>(Init) &&
965 "called emitStoresForInitAfterBZero for zero or undef value.");
966
967 if (isa<llvm::ConstantInt>(Val: Init) || isa<llvm::ConstantFP>(Val: Init) ||
968 isa<llvm::ConstantVector>(Val: Init) || isa<llvm::BlockAddress>(Val: Init) ||
969 isa<llvm::ConstantExpr>(Val: Init)) {
970 auto *I = Builder.CreateStore(Val: Init, Addr: Loc, IsVolatile: isVolatile);
971 addInstToCurrentSourceAtom(KeyInstruction: I, Backup: nullptr);
972 if (IsAutoInit)
973 I->addAnnotationMetadata(Annotation: "auto-init");
974 return;
975 }
976
977 if (llvm::ConstantDataSequential *CDS =
978 dyn_cast<llvm::ConstantDataSequential>(Val: Init)) {
979 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
980 llvm::Constant *Elt = CDS->getElementAsConstant(i);
981
982 // If necessary, get a pointer to the element and emit it.
983 if (!Elt->isNullValue() && !isa<llvm::UndefValue>(Val: Elt))
984 emitStoresForInitAfterBZero(
985 Init: Elt, Loc: Builder.CreateConstInBoundsGEP2_32(Addr: Loc, Idx0: 0, Idx1: i), isVolatile,
986 IsAutoInit);
987 }
988 return;
989 }
990
991 assert((isa<llvm::ConstantStruct>(Init) || isa<llvm::ConstantArray>(Init)) &&
992 "Unknown value type!");
993
994 for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
995 llvm::Constant *Elt = cast<llvm::Constant>(Val: Init->getOperand(i));
996
997 // If necessary, get a pointer to the element and emit it.
998 if (!Elt->isNullValue() && !isa<llvm::UndefValue>(Val: Elt))
999 emitStoresForInitAfterBZero(Init: Elt,
1000 Loc: Builder.CreateConstInBoundsGEP2_32(Addr: Loc, Idx0: 0, Idx1: i),
1001 isVolatile, IsAutoInit);
1002 }
1003}
1004
1005/// Decide whether we should use bzero plus some stores to initialize a local
1006/// variable instead of using a memcpy from a constant global. It is beneficial
1007/// to use bzero if the global is all zeros, or mostly zeros and large.
1008static bool shouldUseBZeroPlusStoresToInitialize(llvm::Constant *Init,
1009 uint64_t GlobalSize) {
1010 // If a global is all zeros, always use a bzero.
1011 if (isa<llvm::ConstantAggregateZero>(Val: Init)) return true;
1012
1013 // If a non-zero global is <= 32 bytes, always use a memcpy. If it is large,
1014 // do it if it will require 6 or fewer scalar stores.
1015 // TODO: Should budget depends on the size? Avoiding a large global warrants
1016 // plopping in more stores.
1017 unsigned StoreBudget = 6;
1018 uint64_t SizeLimit = 32;
1019
1020 return GlobalSize > SizeLimit &&
1021 canEmitInitWithFewStoresAfterBZero(Init, NumStores&: StoreBudget);
1022}
1023
1024/// Decide whether we should use memset to initialize a local variable instead
1025/// of using a memcpy from a constant global. Assumes we've already decided to
1026/// not user bzero.
1027/// FIXME We could be more clever, as we are for bzero above, and generate
1028/// memset followed by stores. It's unclear that's worth the effort.
1029static llvm::Value *shouldUseMemSetToInitialize(llvm::Constant *Init,
1030 uint64_t GlobalSize,
1031 const llvm::DataLayout &DL) {
1032 uint64_t SizeLimit = 32;
1033 if (GlobalSize <= SizeLimit)
1034 return nullptr;
1035 return llvm::isBytewiseValue(V: Init, DL);
1036}
1037
1038/// Decide whether we want to split a constant structure or array store into a
1039/// sequence of its fields' stores. This may cost us code size and compilation
1040/// speed, but plays better with store optimizations.
1041static bool shouldSplitConstantStore(CodeGenModule &CGM,
1042 uint64_t GlobalByteSize) {
1043 // Don't break things that occupy more than one cacheline.
1044 uint64_t ByteSizeLimit = 64;
1045 if (CGM.getCodeGenOpts().OptimizationLevel == 0)
1046 return false;
1047 if (GlobalByteSize <= ByteSizeLimit)
1048 return true;
1049 return false;
1050}
1051
1052enum class IsPattern { No, Yes };
1053
1054/// Generate a constant filled with either a pattern or zeroes.
1055static llvm::Constant *patternOrZeroFor(CodeGenModule &CGM, IsPattern isPattern,
1056 llvm::Type *Ty) {
1057 if (isPattern == IsPattern::Yes)
1058 return initializationPatternFor(CGM, Ty);
1059 else
1060 return llvm::Constant::getNullValue(Ty);
1061}
1062
1063static llvm::Constant *constWithPadding(CodeGenModule &CGM, IsPattern isPattern,
1064 llvm::Constant *constant);
1065
1066/// Helper function for constWithPadding() to deal with padding in structures.
1067static llvm::Constant *constStructWithPadding(CodeGenModule &CGM,
1068 IsPattern isPattern,
1069 llvm::StructType *STy,
1070 llvm::Constant *constant) {
1071 const llvm::DataLayout &DL = CGM.getDataLayout();
1072 const llvm::StructLayout *Layout = DL.getStructLayout(Ty: STy);
1073 llvm::Type *Int8Ty = llvm::IntegerType::getInt8Ty(C&: CGM.getLLVMContext());
1074 unsigned SizeSoFar = 0;
1075 SmallVector<llvm::Constant *, 8> Values;
1076 bool NestedIntact = true;
1077 for (unsigned i = 0, e = STy->getNumElements(); i != e; i++) {
1078 unsigned CurOff = Layout->getElementOffset(Idx: i);
1079 if (SizeSoFar < CurOff) {
1080 assert(!STy->isPacked());
1081 auto *PadTy = llvm::ArrayType::get(ElementType: Int8Ty, NumElements: CurOff - SizeSoFar);
1082 Values.push_back(Elt: patternOrZeroFor(CGM, isPattern, Ty: PadTy));
1083 }
1084 llvm::Constant *CurOp;
1085 if (constant->isNullValue())
1086 CurOp = llvm::Constant::getNullValue(Ty: STy->getElementType(N: i));
1087 else
1088 CurOp = cast<llvm::Constant>(Val: constant->getAggregateElement(Elt: i));
1089 auto *NewOp = constWithPadding(CGM, isPattern, constant: CurOp);
1090 if (CurOp != NewOp)
1091 NestedIntact = false;
1092 Values.push_back(Elt: NewOp);
1093 SizeSoFar = CurOff + DL.getTypeAllocSize(Ty: CurOp->getType());
1094 }
1095 unsigned TotalSize = Layout->getSizeInBytes();
1096 if (SizeSoFar < TotalSize) {
1097 auto *PadTy = llvm::ArrayType::get(ElementType: Int8Ty, NumElements: TotalSize - SizeSoFar);
1098 Values.push_back(Elt: patternOrZeroFor(CGM, isPattern, Ty: PadTy));
1099 }
1100 if (NestedIntact && Values.size() == STy->getNumElements())
1101 return constant;
1102 return llvm::ConstantStruct::getAnon(V: Values, Packed: STy->isPacked());
1103}
1104
1105/// Replace all padding bytes in a given constant with either a pattern byte or
1106/// 0x00.
1107static llvm::Constant *constWithPadding(CodeGenModule &CGM, IsPattern isPattern,
1108 llvm::Constant *constant) {
1109 llvm::Type *OrigTy = constant->getType();
1110 if (const auto STy = dyn_cast<llvm::StructType>(Val: OrigTy))
1111 return constStructWithPadding(CGM, isPattern, STy, constant);
1112 if (auto *ArrayTy = dyn_cast<llvm::ArrayType>(Val: OrigTy)) {
1113 llvm::SmallVector<llvm::Constant *, 8> Values;
1114 uint64_t Size = ArrayTy->getNumElements();
1115 if (!Size)
1116 return constant;
1117 llvm::Type *ElemTy = ArrayTy->getElementType();
1118 bool ZeroInitializer = constant->isNullValue();
1119 llvm::Constant *OpValue, *PaddedOp;
1120 if (ZeroInitializer) {
1121 OpValue = llvm::Constant::getNullValue(Ty: ElemTy);
1122 PaddedOp = constWithPadding(CGM, isPattern, constant: OpValue);
1123 }
1124 for (unsigned Op = 0; Op != Size; ++Op) {
1125 if (!ZeroInitializer) {
1126 OpValue = constant->getAggregateElement(Elt: Op);
1127 PaddedOp = constWithPadding(CGM, isPattern, constant: OpValue);
1128 }
1129 Values.push_back(Elt: PaddedOp);
1130 }
1131 auto *NewElemTy = Values[0]->getType();
1132 if (NewElemTy == ElemTy)
1133 return constant;
1134 auto *NewArrayTy = llvm::ArrayType::get(ElementType: NewElemTy, NumElements: Size);
1135 return llvm::ConstantArray::get(T: NewArrayTy, V: Values);
1136 }
1137 // FIXME: Add handling for tail padding in vectors. Vectors don't
1138 // have padding between or inside elements, but the total amount of
1139 // data can be less than the allocated size.
1140 return constant;
1141}
1142
1143Address CodeGenModule::createUnnamedGlobalFrom(const VarDecl &D,
1144 llvm::Constant *Constant,
1145 CharUnits Align) {
1146 auto FunctionName = [&](const DeclContext *DC) -> std::string {
1147 if (const auto *FD = dyn_cast<FunctionDecl>(Val: DC)) {
1148 if (const auto *CC = dyn_cast<CXXConstructorDecl>(Val: FD))
1149 return CC->getNameAsString();
1150 if (const auto *CD = dyn_cast<CXXDestructorDecl>(Val: FD))
1151 return CD->getNameAsString();
1152 return std::string(getMangledName(GD: FD));
1153 } else if (const auto *OM = dyn_cast<ObjCMethodDecl>(Val: DC)) {
1154 return OM->getNameAsString();
1155 } else if (isa<BlockDecl>(Val: DC)) {
1156 return "<block>";
1157 } else if (isa<CapturedDecl>(Val: DC)) {
1158 return "<captured>";
1159 } else {
1160 llvm_unreachable("expected a function or method");
1161 }
1162 };
1163
1164 // Form a simple per-variable cache of these values in case we find we
1165 // want to reuse them.
1166 llvm::GlobalVariable *&CacheEntry = InitializerConstants[&D];
1167 if (!CacheEntry || CacheEntry->getInitializer() != Constant) {
1168 auto *Ty = Constant->getType();
1169 bool isConstant = true;
1170 llvm::GlobalVariable *InsertBefore = nullptr;
1171 unsigned AS =
1172 getContext().getTargetAddressSpace(AS: GetGlobalConstantAddressSpace());
1173 std::string Name;
1174 if (D.hasGlobalStorage())
1175 Name = getMangledName(GD: &D).str() + ".const";
1176 else if (const DeclContext *DC = D.getParentFunctionOrMethod())
1177 Name = ("__const." + FunctionName(DC) + "." + D.getName()).str();
1178 else
1179 llvm_unreachable("local variable has no parent function or method");
1180 llvm::GlobalVariable *GV = new llvm::GlobalVariable(
1181 getModule(), Ty, isConstant, llvm::GlobalValue::PrivateLinkage,
1182 Constant, Name, InsertBefore, llvm::GlobalValue::NotThreadLocal, AS);
1183 GV->setAlignment(Align.getAsAlign());
1184 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1185 CacheEntry = GV;
1186 } else if (CacheEntry->getAlign().valueOrOne() < Align.getAsAlign()) {
1187 CacheEntry->setAlignment(Align.getAsAlign());
1188 }
1189
1190 return Address(CacheEntry, CacheEntry->getValueType(), Align);
1191}
1192
1193static Address createUnnamedGlobalForMemcpyFrom(CodeGenModule &CGM,
1194 const VarDecl &D,
1195 CGBuilderTy &Builder,
1196 llvm::Constant *Constant,
1197 CharUnits Align) {
1198 Address SrcPtr = CGM.createUnnamedGlobalFrom(D, Constant, Align);
1199 return SrcPtr.withElementType(ElemTy: CGM.Int8Ty);
1200}
1201
1202void CodeGenFunction::emitStoresForConstant(const VarDecl &D, Address Loc,
1203 bool isVolatile,
1204 llvm::Constant *constant,
1205 bool IsAutoInit) {
1206 auto *Ty = constant->getType();
1207 uint64_t ConstantSize = CGM.getDataLayout().getTypeAllocSize(Ty);
1208 if (!ConstantSize)
1209 return;
1210
1211 bool canDoSingleStore = Ty->isIntOrIntVectorTy() ||
1212 Ty->isPtrOrPtrVectorTy() || Ty->isFPOrFPVectorTy();
1213 if (canDoSingleStore) {
1214 auto *I = Builder.CreateStore(Val: constant, Addr: Loc, IsVolatile: isVolatile);
1215 addInstToCurrentSourceAtom(KeyInstruction: I, Backup: nullptr);
1216 if (IsAutoInit)
1217 I->addAnnotationMetadata(Annotation: "auto-init");
1218 return;
1219 }
1220
1221 auto *SizeVal = llvm::ConstantInt::get(Ty: CGM.IntPtrTy, V: ConstantSize);
1222
1223 // If the initializer is all or mostly the same, codegen with bzero / memset
1224 // then do a few stores afterward.
1225 if (shouldUseBZeroPlusStoresToInitialize(Init: constant, GlobalSize: ConstantSize)) {
1226 auto *I = Builder.CreateMemSet(Dest: Loc, Value: llvm::ConstantInt::get(Ty: CGM.Int8Ty, V: 0),
1227 Size: SizeVal, IsVolatile: isVolatile);
1228 addInstToCurrentSourceAtom(KeyInstruction: I, Backup: nullptr);
1229
1230 if (IsAutoInit)
1231 I->addAnnotationMetadata(Annotation: "auto-init");
1232
1233 bool valueAlreadyCorrect =
1234 constant->isNullValue() || isa<llvm::UndefValue>(Val: constant);
1235 if (!valueAlreadyCorrect) {
1236 Loc = Loc.withElementType(ElemTy: Ty);
1237 emitStoresForInitAfterBZero(Init: constant, Loc, isVolatile, IsAutoInit);
1238 }
1239 return;
1240 }
1241
1242 // If the initializer is a repeated byte pattern, use memset.
1243 llvm::Value *Pattern =
1244 shouldUseMemSetToInitialize(Init: constant, GlobalSize: ConstantSize, DL: CGM.getDataLayout());
1245 if (Pattern) {
1246 uint64_t Value = 0x00;
1247 if (!isa<llvm::UndefValue>(Val: Pattern)) {
1248 const llvm::APInt &AP = cast<llvm::ConstantInt>(Val: Pattern)->getValue();
1249 assert(AP.getBitWidth() <= 8);
1250 Value = AP.getLimitedValue();
1251 }
1252 auto *I = Builder.CreateMemSet(
1253 Dest: Loc, Value: llvm::ConstantInt::get(Ty: CGM.Int8Ty, V: Value), Size: SizeVal, IsVolatile: isVolatile);
1254 addInstToCurrentSourceAtom(KeyInstruction: I, Backup: nullptr);
1255 if (IsAutoInit)
1256 I->addAnnotationMetadata(Annotation: "auto-init");
1257 return;
1258 }
1259
1260 // If the initializer is small or trivialAutoVarInit is set, use a handful of
1261 // stores.
1262 bool IsTrivialAutoVarInitPattern =
1263 CGM.getContext().getLangOpts().getTrivialAutoVarInit() ==
1264 LangOptions::TrivialAutoVarInitKind::Pattern;
1265 if (shouldSplitConstantStore(CGM, GlobalByteSize: ConstantSize)) {
1266 if (auto *STy = dyn_cast<llvm::StructType>(Val: Ty)) {
1267 if (STy == Loc.getElementType() || IsTrivialAutoVarInitPattern) {
1268 const llvm::StructLayout *Layout =
1269 CGM.getDataLayout().getStructLayout(Ty: STy);
1270 for (unsigned i = 0; i != constant->getNumOperands(); i++) {
1271 CharUnits CurOff =
1272 CharUnits::fromQuantity(Quantity: Layout->getElementOffset(Idx: i));
1273 Address EltPtr = Builder.CreateConstInBoundsByteGEP(
1274 Addr: Loc.withElementType(ElemTy: CGM.Int8Ty), Offset: CurOff);
1275 emitStoresForConstant(D, Loc: EltPtr, isVolatile,
1276 constant: constant->getAggregateElement(Elt: i), IsAutoInit);
1277 }
1278 return;
1279 }
1280 } else if (auto *ATy = dyn_cast<llvm::ArrayType>(Val: Ty)) {
1281 if (ATy == Loc.getElementType() || IsTrivialAutoVarInitPattern) {
1282 for (unsigned i = 0; i != ATy->getNumElements(); i++) {
1283 Address EltPtr = Builder.CreateConstGEP(
1284 Addr: Loc.withElementType(ElemTy: ATy->getElementType()), Index: i);
1285 emitStoresForConstant(D, Loc: EltPtr, isVolatile,
1286 constant: constant->getAggregateElement(Elt: i), IsAutoInit);
1287 }
1288 return;
1289 }
1290 }
1291 }
1292
1293 // Copy from a global.
1294 auto *I =
1295 Builder.CreateMemCpy(Dest: Loc,
1296 Src: createUnnamedGlobalForMemcpyFrom(
1297 CGM, D, Builder, Constant: constant, Align: Loc.getAlignment()),
1298 Size: SizeVal, IsVolatile: isVolatile);
1299 addInstToCurrentSourceAtom(KeyInstruction: I, Backup: nullptr);
1300
1301 if (IsAutoInit)
1302 I->addAnnotationMetadata(Annotation: "auto-init");
1303}
1304
1305void CodeGenFunction::emitStoresForZeroInit(const VarDecl &D, Address Loc,
1306 bool isVolatile) {
1307 llvm::Type *ElTy = Loc.getElementType();
1308 llvm::Constant *constant =
1309 constWithPadding(CGM, isPattern: IsPattern::No, constant: llvm::Constant::getNullValue(Ty: ElTy));
1310 emitStoresForConstant(D, Loc, isVolatile, constant,
1311 /*IsAutoInit=*/true);
1312}
1313
1314void CodeGenFunction::emitStoresForPatternInit(const VarDecl &D, Address Loc,
1315 bool isVolatile) {
1316 llvm::Type *ElTy = Loc.getElementType();
1317 llvm::Constant *constant = constWithPadding(
1318 CGM, isPattern: IsPattern::Yes, constant: initializationPatternFor(CGM, ElTy));
1319 assert(!isa<llvm::UndefValue>(constant));
1320 emitStoresForConstant(D, Loc, isVolatile, constant,
1321 /*IsAutoInit=*/true);
1322}
1323
1324static bool containsUndef(llvm::Constant *constant) {
1325 auto *Ty = constant->getType();
1326 if (isa<llvm::UndefValue>(Val: constant))
1327 return true;
1328 if (Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy())
1329 for (llvm::Use &Op : constant->operands())
1330 if (containsUndef(constant: cast<llvm::Constant>(Val&: Op)))
1331 return true;
1332 return false;
1333}
1334
1335static llvm::Constant *replaceUndef(CodeGenModule &CGM, IsPattern isPattern,
1336 llvm::Constant *constant) {
1337 auto *Ty = constant->getType();
1338 if (isa<llvm::UndefValue>(Val: constant))
1339 return patternOrZeroFor(CGM, isPattern, Ty);
1340 if (!(Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()))
1341 return constant;
1342 if (!containsUndef(constant))
1343 return constant;
1344 llvm::SmallVector<llvm::Constant *, 8> Values(constant->getNumOperands());
1345 for (unsigned Op = 0, NumOp = constant->getNumOperands(); Op != NumOp; ++Op) {
1346 auto *OpValue = cast<llvm::Constant>(Val: constant->getOperand(i: Op));
1347 Values[Op] = replaceUndef(CGM, isPattern, constant: OpValue);
1348 }
1349 if (Ty->isStructTy())
1350 return llvm::ConstantStruct::get(T: cast<llvm::StructType>(Val: Ty), V: Values);
1351 if (Ty->isArrayTy())
1352 return llvm::ConstantArray::get(T: cast<llvm::ArrayType>(Val: Ty), V: Values);
1353 assert(Ty->isVectorTy());
1354 return llvm::ConstantVector::get(V: Values);
1355}
1356
1357/// EmitAutoVarDecl - Emit code and set up an entry in LocalDeclMap for a
1358/// variable declaration with auto, register, or no storage class specifier.
1359/// These turn into simple stack objects, or GlobalValues depending on target.
1360void CodeGenFunction::EmitAutoVarDecl(const VarDecl &D) {
1361 AutoVarEmission emission = EmitAutoVarAlloca(var: D);
1362 EmitAutoVarInit(emission);
1363 EmitAutoVarCleanups(emission);
1364}
1365
1366/// Emit a lifetime.begin marker if some criteria are satisfied.
1367/// \return whether the marker was emitted.
1368bool CodeGenFunction::EmitLifetimeStart(llvm::Value *Addr) {
1369 if (!ShouldEmitLifetimeMarkers)
1370 return false;
1371
1372 assert(Addr->getType()->getPointerAddressSpace() ==
1373 CGM.getDataLayout().getAllocaAddrSpace() &&
1374 "Pointer should be in alloca address space");
1375 llvm::CallInst *C = Builder.CreateCall(Callee: CGM.getLLVMLifetimeStartFn(), Args: {Addr});
1376 C->setDoesNotThrow();
1377 return true;
1378}
1379
1380void CodeGenFunction::EmitLifetimeEnd(llvm::Value *Addr) {
1381 if (!ShouldEmitLifetimeMarkers)
1382 return;
1383
1384 assert(Addr->getType()->getPointerAddressSpace() ==
1385 CGM.getDataLayout().getAllocaAddrSpace() &&
1386 "Pointer should be in alloca address space");
1387 llvm::CallInst *C = Builder.CreateCall(Callee: CGM.getLLVMLifetimeEndFn(), Args: {Addr});
1388 C->setDoesNotThrow();
1389}
1390
1391void CodeGenFunction::EmitFakeUse(Address Addr) {
1392 auto NL = ApplyDebugLocation::CreateEmpty(CGF&: *this);
1393 llvm::Value *V = Builder.CreateLoad(Addr, Name: "fake.use");
1394 llvm::CallInst *C = Builder.CreateCall(Callee: CGM.getLLVMFakeUseFn(), Args: {V});
1395 C->setDoesNotThrow();
1396 C->setTailCallKind(llvm::CallInst::TCK_NoTail);
1397}
1398
1399void CodeGenFunction::EmitAndRegisterVariableArrayDimensions(
1400 CGDebugInfo *DI, const VarDecl &D, bool EmitDebugInfo) {
1401 // For each dimension stores its QualType and corresponding
1402 // size-expression Value.
1403 SmallVector<CodeGenFunction::VlaSizePair, 4> Dimensions;
1404 SmallVector<const IdentifierInfo *, 4> VLAExprNames;
1405
1406 // Break down the array into individual dimensions.
1407 QualType Type1D = D.getType();
1408 while (getContext().getAsVariableArrayType(T: Type1D)) {
1409 auto VlaSize = getVLAElements1D(vla: Type1D);
1410 if (auto *C = dyn_cast<llvm::ConstantInt>(Val: VlaSize.NumElts))
1411 Dimensions.emplace_back(Args&: C, Args: Type1D.getUnqualifiedType());
1412 else {
1413 // Generate a locally unique name for the size expression.
1414 Twine Name = Twine("__vla_expr") + Twine(VLAExprCounter++);
1415 SmallString<12> Buffer;
1416 StringRef NameRef = Name.toStringRef(Out&: Buffer);
1417 auto &Ident = getContext().Idents.getOwn(Name: NameRef);
1418 VLAExprNames.push_back(Elt: &Ident);
1419 auto SizeExprAddr =
1420 CreateDefaultAlignTempAlloca(Ty: VlaSize.NumElts->getType(), Name: NameRef);
1421 Builder.CreateStore(Val: VlaSize.NumElts, Addr: SizeExprAddr);
1422 Dimensions.emplace_back(Args: SizeExprAddr.getPointer(),
1423 Args: Type1D.getUnqualifiedType());
1424 }
1425 Type1D = VlaSize.Type;
1426 }
1427
1428 if (!EmitDebugInfo)
1429 return;
1430
1431 // Register each dimension's size-expression with a DILocalVariable,
1432 // so that it can be used by CGDebugInfo when instantiating a DISubrange
1433 // to describe this array.
1434 unsigned NameIdx = 0;
1435 for (auto &VlaSize : Dimensions) {
1436 llvm::Metadata *MD;
1437 if (auto *C = dyn_cast<llvm::ConstantInt>(Val: VlaSize.NumElts))
1438 MD = llvm::ConstantAsMetadata::get(C);
1439 else {
1440 // Create an artificial VarDecl to generate debug info for.
1441 const IdentifierInfo *NameIdent = VLAExprNames[NameIdx++];
1442 auto QT = getContext().getIntTypeForBitwidth(
1443 DestWidth: SizeTy->getScalarSizeInBits(), Signed: false);
1444 auto *ArtificialDecl = VarDecl::Create(
1445 C&: getContext(), DC: const_cast<DeclContext *>(D.getDeclContext()),
1446 StartLoc: D.getLocation(), IdLoc: D.getLocation(), Id: NameIdent, T: QT,
1447 TInfo: getContext().CreateTypeSourceInfo(T: QT), S: SC_Auto);
1448 ArtificialDecl->setImplicit();
1449
1450 MD = DI->EmitDeclareOfAutoVariable(Decl: ArtificialDecl, AI: VlaSize.NumElts,
1451 Builder);
1452 }
1453 assert(MD && "No Size expression debug node created");
1454 DI->registerVLASizeExpression(Ty: VlaSize.Type, SizeExpr: MD);
1455 }
1456}
1457
1458/// Return the maximum size of an aggregate for which we generate a fake use
1459/// intrinsic when -fextend-variable-liveness is in effect.
1460static uint64_t maxFakeUseAggregateSize(const ASTContext &C) {
1461 return 4 * C.getTypeSize(T: C.UnsignedIntTy);
1462}
1463
1464// Helper function to determine whether a variable's or parameter's lifetime
1465// should be extended.
1466static bool shouldExtendLifetime(const ASTContext &Context,
1467 const Decl *FuncDecl, const VarDecl &D,
1468 ImplicitParamDecl *CXXABIThisDecl) {
1469 // When we're not inside a valid function it is unlikely that any
1470 // lifetime extension is useful.
1471 if (!FuncDecl)
1472 return false;
1473 if (FuncDecl->isImplicit())
1474 return false;
1475 // Do not extend compiler-created variables except for the this pointer.
1476 if (D.isImplicit() && &D != CXXABIThisDecl)
1477 return false;
1478 QualType Ty = D.getType();
1479 // No need to extend volatiles, they have a memory location.
1480 if (Ty.isVolatileQualified())
1481 return false;
1482 // Don't extend variables that exceed a certain size.
1483 if (Context.getTypeSize(T: Ty) > maxFakeUseAggregateSize(C: Context))
1484 return false;
1485 // Do not extend variables in nodebug or optnone functions.
1486 if (FuncDecl->hasAttr<NoDebugAttr>() || FuncDecl->hasAttr<OptimizeNoneAttr>())
1487 return false;
1488 return true;
1489}
1490
1491/// EmitAutoVarAlloca - Emit the alloca and debug information for a
1492/// local variable. Does not emit initialization or destruction.
1493CodeGenFunction::AutoVarEmission
1494CodeGenFunction::EmitAutoVarAlloca(const VarDecl &D) {
1495 QualType Ty = D.getType();
1496 assert(
1497 Ty.getAddressSpace() == LangAS::Default ||
1498 (Ty.getAddressSpace() == LangAS::opencl_private && getLangOpts().OpenCL));
1499
1500 AutoVarEmission emission(D);
1501
1502 bool isEscapingByRef = D.isEscapingByref();
1503 emission.IsEscapingByRef = isEscapingByRef;
1504
1505 CharUnits alignment = getContext().getDeclAlign(D: &D);
1506
1507 // If the type is variably-modified, emit all the VLA sizes for it.
1508 if (Ty->isVariablyModifiedType())
1509 EmitVariablyModifiedType(Ty);
1510
1511 auto *DI = getDebugInfo();
1512 bool EmitDebugInfo = DI && CGM.getCodeGenOpts().hasReducedDebugInfo();
1513
1514 Address address = Address::invalid();
1515 RawAddress AllocaAddr = RawAddress::invalid();
1516 Address OpenMPLocalAddr = Address::invalid();
1517 if (CGM.getLangOpts().OpenMPIRBuilder)
1518 OpenMPLocalAddr = OMPBuilderCBHelpers::getAddressOfLocalVariable(CGF&: *this, VD: &D);
1519 else
1520 OpenMPLocalAddr =
1521 getLangOpts().OpenMP
1522 ? CGM.getOpenMPRuntime().getAddressOfLocalVariable(CGF&: *this, VD: &D)
1523 : Address::invalid();
1524
1525 bool NRVO = getLangOpts().ElideConstructors && D.isNRVOVariable();
1526
1527 if (getLangOpts().OpenMP && OpenMPLocalAddr.isValid()) {
1528 address = OpenMPLocalAddr;
1529 AllocaAddr = OpenMPLocalAddr;
1530 } else if (Ty->isConstantSizeType()) {
1531 // If this value is an array or struct with a statically determinable
1532 // constant initializer, there are optimizations we can do.
1533 //
1534 // TODO: We should be able to delete most of the restrictions here; there's
1535 // no reason we specifically need a POD array/record type. But we'd need to
1536 // evaluate the performance, update regression tests, and fix a crash with
1537 // OpenMP.
1538 if (D.getInit() && (Ty->isArrayType() || Ty->isRecordType()) &&
1539 (D.isConstexpr() ||
1540 ((Ty.isPODType(Context: getContext()) ||
1541 getContext().getBaseElementType(QT: Ty)->isObjCObjectPointerType())))) {
1542 emission.ConstantAggregateInitializer =
1543 ConstantEmitter(*this).tryEmitAbstractForInitializer(D);
1544 if (emission.ConstantAggregateInitializer) {
1545 // If the variable's a const type, and it's neither an NRVO
1546 // candidate nor a __block variable and has no mutable members,
1547 // emit it as a global instead.
1548 // Exception is if a variable is located in non-constant address space
1549 // in OpenCL.
1550 bool NeedsDtor =
1551 D.needsDestruction(Ctx: getContext()) == QualType::DK_cxx_destructor;
1552 if ((!getLangOpts().OpenCL ||
1553 Ty.getAddressSpace() == LangAS::opencl_constant) &&
1554 (CGM.getCodeGenOpts().MergeAllConstants && !NRVO &&
1555 !isEscapingByRef &&
1556 Ty.isConstantStorage(Ctx: getContext(), ExcludeCtor: true, ExcludeDtor: !NeedsDtor))) {
1557 EmitStaticVarDecl(D, Linkage: llvm::GlobalValue::InternalLinkage);
1558
1559 // Signal this condition to later callbacks.
1560 emission.Addr = Address::invalid();
1561 assert(emission.wasEmittedAsGlobal());
1562 return emission;
1563 }
1564 }
1565 }
1566
1567 // A normal fixed sized variable becomes an alloca in the entry block,
1568 // unless:
1569 // - it's an NRVO variable.
1570 // - we are compiling OpenMP and it's an OpenMP local variable.
1571 if (NRVO) {
1572 // The named return value optimization: allocate this variable in the
1573 // return slot, so that we can elide the copy when returning this
1574 // variable (C++0x [class.copy]p34).
1575 AllocaAddr =
1576 RawAddress(ReturnValue.emitRawPointer(CGF&: *this),
1577 ReturnValue.getElementType(), ReturnValue.getAlignment());
1578 address = MaybeCastStackAddressSpace(Alloca: AllocaAddr, DestLangAS: Ty.getAddressSpace());
1579
1580 if (const auto *RD = Ty->getAsRecordDecl()) {
1581 if (const auto *CXXRD = dyn_cast<CXXRecordDecl>(Val: RD);
1582 (CXXRD && !CXXRD->hasTrivialDestructor()) ||
1583 RD->isNonTrivialToPrimitiveDestroy()) {
1584 // Create a flag that is used to indicate when the NRVO was applied
1585 // to this variable. Set it to zero to indicate that NRVO was not
1586 // applied.
1587 llvm::Value *Zero = Builder.getFalse();
1588 RawAddress NRVOFlag =
1589 CreateTempAlloca(Ty: Zero->getType(), align: CharUnits::One(), Name: "nrvo");
1590 EnsureInsertPoint();
1591 Builder.CreateStore(Val: Zero, Addr: NRVOFlag);
1592
1593 // Record the NRVO flag for this variable.
1594 NRVOFlags[&D] = NRVOFlag.getPointer();
1595 emission.NRVOFlag = NRVOFlag.getPointer();
1596 }
1597 }
1598 } else {
1599 CharUnits allocaAlignment;
1600 llvm::Type *allocaTy;
1601 if (isEscapingByRef) {
1602 auto &byrefInfo = getBlockByrefInfo(var: &D);
1603 allocaTy = byrefInfo.Type;
1604 allocaAlignment = byrefInfo.ByrefAlignment;
1605 } else {
1606 allocaTy = ConvertTypeForMem(T: Ty);
1607 allocaAlignment = alignment;
1608 }
1609
1610 // Create the alloca. Note that we set the name separately from
1611 // building the instruction so that it's there even in no-asserts
1612 // builds.
1613 address = CreateTempAlloca(Ty: allocaTy, UseAddrSpace: Ty.getAddressSpace(),
1614 align: allocaAlignment, Name: D.getName(),
1615 /*ArraySize=*/nullptr, Alloca: &AllocaAddr);
1616
1617 // Don't emit lifetime markers for MSVC catch parameters. The lifetime of
1618 // the catch parameter starts in the catchpad instruction, and we can't
1619 // insert code in those basic blocks.
1620 bool IsMSCatchParam =
1621 D.isExceptionVariable() && getTarget().getCXXABI().isMicrosoft();
1622
1623 // Emit a lifetime intrinsic if meaningful. There's no point in doing this
1624 // if we don't have a valid insertion point (?).
1625 if (HaveInsertPoint() && !IsMSCatchParam) {
1626 // If there's a jump into the lifetime of this variable, its lifetime
1627 // gets broken up into several regions in IR, which requires more work
1628 // to handle correctly. For now, just omit the intrinsics; this is a
1629 // rare case, and it's better to just be conservatively correct.
1630 // PR28267.
1631 //
1632 // We have to do this in all language modes if there's a jump past the
1633 // declaration. We also have to do it in C if there's a jump to an
1634 // earlier point in the current block because non-VLA lifetimes begin as
1635 // soon as the containing block is entered, not when its variables
1636 // actually come into scope; suppressing the lifetime annotations
1637 // completely in this case is unnecessarily pessimistic, but again, this
1638 // is rare.
1639 if (!Bypasses.IsBypassed(D: &D) &&
1640 !(!getLangOpts().CPlusPlus && hasLabelBeenSeenInCurrentScope())) {
1641 emission.UseLifetimeMarkers =
1642 EmitLifetimeStart(Addr: AllocaAddr.getPointer());
1643 }
1644 } else {
1645 assert(!emission.useLifetimeMarkers());
1646 }
1647 }
1648
1649 // A variable whose declaration is bypassed by a goto or switch is not
1650 // initialized by EmitAutoVarInit, which runs at the declaration. Emit the
1651 // trivial-auto-var-init separately.
1652 if (Bypasses.IsBypassed(D: &D) && !emission.IsEscapingByRef &&
1653 !Ty->isVariablyModifiedType() &&
1654 getAutoVarInitKind(Ty, D) !=
1655 LangOptions::TrivialAutoVarInitKind::Uninitialized) {
1656 if (!Bypasses.isAlwaysBypassed()) {
1657 // The variable's lifetime restarts on each re-entry into its scope, so
1658 // reinitialize at every bypassing jump. Backward gotos are emitted at
1659 // the jump source, which comes after this alloca; forward gotos and the
1660 // switch dispatch have already been emitted, so patch their init in
1661 // before the jump.
1662 BypassedVarInits.insert(KV: {&D, address});
1663 for (const BypassingForwardJump &FG : BypassingForwardJumps) {
1664 const auto *Vars = Bypasses.getBypassedVarsForSource(Source: FG.Source);
1665 if (!Vars || !Vars->contains(key: &D))
1666 continue;
1667 llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
1668 Builder.SetInsertPoint(FG.Block->getTerminator());
1669 emitZeroOrPatternForAutoVarInit(type: Ty, D, Loc: address);
1670 }
1671 } else {
1672 // A computed goto can jump anywhere, so we can't identify the jumps
1673 // that bypass this declaration. Fall back to initializing once, in the
1674 // function's entry block.
1675 llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
1676 Builder.SetInsertPoint(getPostAllocaInsertPoint());
1677 emitZeroOrPatternForAutoVarInit(type: Ty, D, Loc: address);
1678 }
1679 }
1680
1681 if (D.hasAttr<StackProtectorIgnoreAttr>()) {
1682 if (auto *AI = dyn_cast<llvm::AllocaInst>(Val: address.getBasePointer())) {
1683 llvm::LLVMContext &Ctx = Builder.getContext();
1684 auto *Operand = llvm::ConstantAsMetadata::get(C: Builder.getInt32(C: 0));
1685 AI->setMetadata(Kind: "stack-protector", Node: llvm::MDNode::get(Context&: Ctx, MDs: {Operand}));
1686 }
1687
1688 std::optional<llvm::Attribute::AttrKind> Attr =
1689 CGM.StackProtectorAttribute(D: &D);
1690 if (Attr && (*Attr == llvm::Attribute::StackProtectReq)) {
1691 CGM.getDiags().Report(Loc: D.getLocation(),
1692 DiagID: diag::warn_stack_protection_ignore_attribute);
1693 }
1694 }
1695 } else {
1696 EnsureInsertPoint();
1697
1698 // Delayed globalization for variable length declarations. This ensures that
1699 // the expression representing the length has been emitted and can be used
1700 // by the definition of the VLA. Since this is an escaped declaration, in
1701 // OpenMP we have to use a call to __kmpc_alloc_shared(). The matching
1702 // deallocation call to __kmpc_free_shared() is emitted later.
1703 bool VarAllocated = false;
1704 if (getLangOpts().OpenMPIsTargetDevice) {
1705 auto &RT = CGM.getOpenMPRuntime();
1706 if (RT.isDelayedVariableLengthDecl(CGF&: *this, VD: &D)) {
1707 // Emit call to __kmpc_alloc_shared() instead of the alloca.
1708 std::pair<llvm::Value *, llvm::Value *> AddrSizePair =
1709 RT.getKmpcAllocShared(CGF&: *this, VD: &D);
1710
1711 // Save the address of the allocation:
1712 LValue Base = MakeAddrLValue(V: AddrSizePair.first, T: D.getType(),
1713 Alignment: CGM.getContext().getDeclAlign(D: &D),
1714 Source: AlignmentSource::Decl);
1715 address = Base.getAddress();
1716
1717 // Push a cleanup block to emit the call to __kmpc_free_shared in the
1718 // appropriate location at the end of the scope of the
1719 // __kmpc_alloc_shared functions:
1720 pushKmpcAllocFree(Kind: NormalCleanup, AddrSizePair);
1721
1722 // Mark variable as allocated:
1723 VarAllocated = true;
1724 }
1725 }
1726
1727 if (!VarAllocated) {
1728 if (!DidCallStackSave) {
1729 // Save the stack.
1730 Address Stack =
1731 CreateDefaultAlignTempAlloca(Ty: AllocaInt8PtrTy, Name: "saved_stack");
1732
1733 llvm::Value *V = Builder.CreateStackSave();
1734 assert(V->getType() == AllocaInt8PtrTy);
1735 Builder.CreateStore(Val: V, Addr: Stack);
1736
1737 DidCallStackSave = true;
1738
1739 // Push a cleanup block and restore the stack there.
1740 // FIXME: in general circumstances, this should be an EH cleanup.
1741 pushStackRestore(kind: NormalCleanup, SPMem: Stack);
1742 }
1743
1744 auto VlaSize = getVLASize(vla: Ty);
1745 llvm::Type *llvmTy = ConvertTypeForMem(T: VlaSize.Type);
1746
1747 // Allocate memory for the array.
1748 address = CreateTempAlloca(Ty: llvmTy, align: alignment, Name: "vla", ArraySize: VlaSize.NumElts,
1749 Alloca: &AllocaAddr);
1750 }
1751
1752 // If we have debug info enabled, properly describe the VLA dimensions for
1753 // this type by registering the vla size expression for each of the
1754 // dimensions.
1755 EmitAndRegisterVariableArrayDimensions(DI, D, EmitDebugInfo);
1756 }
1757
1758 setAddrOfLocalVar(VD: &D, Addr: address);
1759 emission.Addr = address;
1760 emission.AllocaAddr = AllocaAddr;
1761
1762 // Emit debug info for local var declaration.
1763 if (EmitDebugInfo && HaveInsertPoint()) {
1764 Address DebugAddr = address;
1765 bool UsePointerValue = NRVO && ReturnValuePointer.isValid();
1766 DI->setLocation(D.getLocation());
1767
1768 // If NRVO, use a pointer to the return address.
1769 if (UsePointerValue) {
1770 DebugAddr = ReturnValuePointer;
1771 AllocaAddr = ReturnValuePointer;
1772 }
1773 (void)DI->EmitDeclareOfAutoVariable(Decl: &D, AI: AllocaAddr.getPointer(), Builder,
1774 UsePointerValue);
1775 }
1776
1777 if (D.hasAttr<AnnotateAttr>() && HaveInsertPoint())
1778 EmitVarAnnotations(D: &D, V: address.emitRawPointer(CGF&: *this));
1779
1780 // Make sure we call @llvm.lifetime.end.
1781 if (emission.useLifetimeMarkers())
1782 EHStack.pushCleanup<CallLifetimeEnd>(
1783 Kind: NormalEHLifetimeMarker, A: emission.getOriginalAllocatedAddress());
1784
1785 // Analogous to lifetime markers, we use a 'cleanup' to emit fake.use
1786 // calls for local variables. We are exempting volatile variables and
1787 // non-scalars larger than 4 times the size of an unsigned int. Larger
1788 // non-scalars are often allocated in memory and may create unnecessary
1789 // overhead.
1790 if (CGM.getCodeGenOpts().getExtendVariableLiveness() ==
1791 CodeGenOptions::ExtendVariableLivenessKind::All) {
1792 if (shouldExtendLifetime(Context: getContext(), FuncDecl: CurCodeDecl, D, CXXABIThisDecl))
1793 EHStack.pushCleanup<FakeUse>(Kind: NormalFakeUse,
1794 A: emission.getAllocatedAddress());
1795 }
1796
1797 return emission;
1798}
1799
1800static bool isCapturedBy(const VarDecl &, const Expr *);
1801
1802/// Determines whether the given __block variable is potentially
1803/// captured by the given statement.
1804static bool isCapturedBy(const VarDecl &Var, const Stmt *S) {
1805 if (const Expr *E = dyn_cast<Expr>(Val: S))
1806 return isCapturedBy(Var, E);
1807 for (const Stmt *SubStmt : S->children())
1808 if (isCapturedBy(Var, S: SubStmt))
1809 return true;
1810 return false;
1811}
1812
1813/// Determines whether the given __block variable is potentially
1814/// captured by the given expression.
1815static bool isCapturedBy(const VarDecl &Var, const Expr *E) {
1816 // Skip the most common kinds of expressions that make
1817 // hierarchy-walking expensive.
1818 E = E->IgnoreParenCasts();
1819
1820 if (const BlockExpr *BE = dyn_cast<BlockExpr>(Val: E)) {
1821 const BlockDecl *Block = BE->getBlockDecl();
1822 for (const auto &I : Block->captures()) {
1823 if (I.getVariable() == &Var)
1824 return true;
1825 }
1826
1827 // No need to walk into the subexpressions.
1828 return false;
1829 }
1830
1831 if (const StmtExpr *SE = dyn_cast<StmtExpr>(Val: E)) {
1832 const CompoundStmt *CS = SE->getSubStmt();
1833 for (const auto *BI : CS->body())
1834 if (const auto *BIE = dyn_cast<Expr>(Val: BI)) {
1835 if (isCapturedBy(Var, E: BIE))
1836 return true;
1837 }
1838 else if (const auto *DS = dyn_cast<DeclStmt>(Val: BI)) {
1839 // special case declarations
1840 for (const auto *I : DS->decls()) {
1841 if (const auto *VD = dyn_cast<VarDecl>(Val: (I))) {
1842 const Expr *Init = VD->getInit();
1843 if (Init && isCapturedBy(Var, E: Init))
1844 return true;
1845 }
1846 }
1847 }
1848 else
1849 // FIXME. Make safe assumption assuming arbitrary statements cause capturing.
1850 // Later, provide code to poke into statements for capture analysis.
1851 return true;
1852 return false;
1853 }
1854
1855 for (const Stmt *SubStmt : E->children())
1856 if (isCapturedBy(Var, S: SubStmt))
1857 return true;
1858
1859 return false;
1860}
1861
1862/// Determine whether the given initializer is trivial in the sense
1863/// that it requires no code to be generated.
1864bool CodeGenFunction::isTrivialInitializer(const Expr *Init) {
1865 if (!Init)
1866 return true;
1867
1868 if (const CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Val: Init))
1869 if (CXXConstructorDecl *Constructor = Construct->getConstructor())
1870 if (Constructor->isTrivial() &&
1871 Constructor->isDefaultConstructor() &&
1872 !Construct->requiresZeroInitialization())
1873 return true;
1874
1875 return false;
1876}
1877
1878LangOptions::TrivialAutoVarInitKind
1879CodeGenFunction::getAutoVarInitKind(QualType Ty, const VarDecl &D) {
1880 auto hasNoTrivialAutoVarInitAttr = [](const Decl *D) {
1881 return D && D->hasAttr<NoTrivialAutoVarInitAttr>();
1882 };
1883 if (D.isConstexpr() || D.getAttr<UninitializedAttr>() ||
1884 hasNoTrivialAutoVarInitAttr(Ty->getAsTagDecl()) ||
1885 hasNoTrivialAutoVarInitAttr(CurFuncDecl))
1886 return LangOptions::TrivialAutoVarInitKind::Uninitialized;
1887 return getContext().getLangOpts().getTrivialAutoVarInit();
1888}
1889
1890void CodeGenFunction::emitBypassedVarInitsForSource(const Stmt *Source) {
1891 // Scope-reentry reinit is only sound when jump sources are known. With a
1892 // computed goto we can't tell whether a jump leaves a variable's scope, so
1893 // EmitAutoVarAlloca falls back to a single function-scope init and we must
1894 // not reinitialize here -- doing so could clobber a still-live variable.
1895 if (Bypasses.isAlwaysBypassed())
1896 return;
1897 const auto *Vars = Bypasses.getBypassedVarsForSource(Source);
1898 if (!Vars)
1899 return;
1900 for (const VarDecl *VD : *Vars) {
1901 auto It = BypassedVarInits.find(Val: VD);
1902 if (It != BypassedVarInits.end())
1903 emitZeroOrPatternForAutoVarInit(type: VD->getType(), D: *VD, Loc: It->second);
1904 }
1905}
1906
1907void CodeGenFunction::emitZeroOrPatternForAutoVarInit(QualType type,
1908 const VarDecl &D,
1909 Address Loc) {
1910 auto trivialAutoVarInit = getContext().getLangOpts().getTrivialAutoVarInit();
1911 auto trivialAutoVarInitMaxSize =
1912 getContext().getLangOpts().TrivialAutoVarInitMaxSize;
1913 CharUnits Size = getContext().getTypeSizeInChars(T: type);
1914 bool isVolatile = type.isVolatileQualified();
1915 if (!Size.isZero()) {
1916 // We skip auto-init variables by their alloc size. Take this as an example:
1917 // "struct Foo {int x; char buff[1024];}" Assume the max-size flag is 1023.
1918 // All Foo type variables will be skipped. Ideally, we only skip the buff
1919 // array and still auto-init X in this example.
1920 // TODO: Improve the size filtering to by member size.
1921 auto allocSize = CGM.getDataLayout().getTypeAllocSize(Ty: Loc.getElementType());
1922 switch (trivialAutoVarInit) {
1923 case LangOptions::TrivialAutoVarInitKind::Uninitialized:
1924 llvm_unreachable("Uninitialized handled by caller");
1925 case LangOptions::TrivialAutoVarInitKind::Zero:
1926 if (CGM.stopAutoInit())
1927 return;
1928 if (trivialAutoVarInitMaxSize > 0 &&
1929 allocSize > trivialAutoVarInitMaxSize)
1930 return;
1931 emitStoresForZeroInit(D, Loc, isVolatile);
1932 break;
1933 case LangOptions::TrivialAutoVarInitKind::Pattern:
1934 if (CGM.stopAutoInit())
1935 return;
1936 if (trivialAutoVarInitMaxSize > 0 &&
1937 allocSize > trivialAutoVarInitMaxSize)
1938 return;
1939 emitStoresForPatternInit(D, Loc, isVolatile);
1940 break;
1941 }
1942 return;
1943 }
1944
1945 // VLAs look zero-sized to getTypeInfo. We can't emit constant stores to
1946 // them, so emit a memcpy with the VLA size to initialize each element.
1947 // Technically zero-sized or negative-sized VLAs are undefined, and UBSan
1948 // will catch that code, but there exists code which generates zero-sized
1949 // VLAs. Be nice and initialize whatever they requested.
1950 const auto *VlaType = getContext().getAsVariableArrayType(T: type);
1951 if (!VlaType)
1952 return;
1953 auto VlaSize = getVLASize(vla: VlaType);
1954 auto SizeVal = VlaSize.NumElts;
1955 CharUnits EltSize = getContext().getTypeSizeInChars(T: VlaSize.Type);
1956 switch (trivialAutoVarInit) {
1957 case LangOptions::TrivialAutoVarInitKind::Uninitialized:
1958 llvm_unreachable("Uninitialized handled by caller");
1959
1960 case LangOptions::TrivialAutoVarInitKind::Zero: {
1961 if (CGM.stopAutoInit())
1962 return;
1963 if (!EltSize.isOne())
1964 SizeVal = Builder.CreateNUWMul(LHS: SizeVal, RHS: CGM.getSize(numChars: EltSize));
1965 auto *I = Builder.CreateMemSet(Dest: Loc, Value: llvm::ConstantInt::get(Ty: Int8Ty, V: 0),
1966 Size: SizeVal, IsVolatile: isVolatile);
1967 I->addAnnotationMetadata(Annotation: "auto-init");
1968 break;
1969 }
1970
1971 case LangOptions::TrivialAutoVarInitKind::Pattern: {
1972 if (CGM.stopAutoInit())
1973 return;
1974 llvm::Type *ElTy = Loc.getElementType();
1975 llvm::Constant *Constant = constWithPadding(
1976 CGM, isPattern: IsPattern::Yes, constant: initializationPatternFor(CGM, ElTy));
1977 CharUnits ConstantAlign = getContext().getTypeAlignInChars(T: VlaSize.Type);
1978 llvm::BasicBlock *SetupBB = createBasicBlock(name: "vla-setup.loop");
1979 llvm::BasicBlock *LoopBB = createBasicBlock(name: "vla-init.loop");
1980 llvm::BasicBlock *ContBB = createBasicBlock(name: "vla-init.cont");
1981 llvm::Value *IsZeroSizedVLA = Builder.CreateICmpEQ(
1982 LHS: SizeVal, RHS: llvm::ConstantInt::get(Ty: SizeVal->getType(), V: 0),
1983 Name: "vla.iszerosized");
1984 Builder.CreateCondBr(Cond: IsZeroSizedVLA, True: ContBB, False: SetupBB);
1985 EmitBlock(BB: SetupBB);
1986 if (!EltSize.isOne())
1987 SizeVal = Builder.CreateNUWMul(LHS: SizeVal, RHS: CGM.getSize(numChars: EltSize));
1988 llvm::Value *BaseSizeInChars =
1989 llvm::ConstantInt::get(Ty: IntPtrTy, V: EltSize.getQuantity());
1990 Address Begin = Loc.withElementType(ElemTy: Int8Ty);
1991 llvm::Value *End = Builder.CreateInBoundsGEP(Ty: Begin.getElementType(),
1992 Ptr: Begin.emitRawPointer(CGF&: *this),
1993 IdxList: SizeVal, Name: "vla.end");
1994 llvm::BasicBlock *OriginBB = Builder.GetInsertBlock();
1995 EmitBlock(BB: LoopBB);
1996 llvm::PHINode *Cur = Builder.CreatePHI(Ty: Begin.getType(), NumReservedValues: 2, Name: "vla.cur");
1997 Cur->addIncoming(V: Begin.emitRawPointer(CGF&: *this), BB: OriginBB);
1998 CharUnits CurAlign = Loc.getAlignment().alignmentOfArrayElement(elementSize: EltSize);
1999 auto *I =
2000 Builder.CreateMemCpy(Dest: Address(Cur, Int8Ty, CurAlign),
2001 Src: createUnnamedGlobalForMemcpyFrom(
2002 CGM, D, Builder, Constant, Align: ConstantAlign),
2003 Size: BaseSizeInChars, IsVolatile: isVolatile);
2004 I->addAnnotationMetadata(Annotation: "auto-init");
2005 llvm::Value *Next =
2006 Builder.CreateInBoundsGEP(Ty: Int8Ty, Ptr: Cur, IdxList: BaseSizeInChars, Name: "vla.next");
2007 llvm::Value *Done = Builder.CreateICmpEQ(LHS: Next, RHS: End, Name: "vla-init.isdone");
2008 Builder.CreateCondBr(Cond: Done, True: ContBB, False: LoopBB);
2009 Cur->addIncoming(V: Next, BB: LoopBB);
2010 EmitBlock(BB: ContBB);
2011 } break;
2012 }
2013}
2014
2015void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) {
2016 assert(emission.Variable && "emission was not valid!");
2017
2018 // If this was emitted as a global constant, we're done.
2019 if (emission.wasEmittedAsGlobal()) return;
2020
2021 const VarDecl &D = *emission.Variable;
2022 auto DL = ApplyDebugLocation::CreateDefaultArtificial(CGF&: *this, TemporaryLocation: D.getLocation());
2023 ApplyAtomGroup Grp(getDebugInfo());
2024 QualType type = D.getType();
2025
2026 // If this local has an initializer, emit it now.
2027 const Expr *Init = D.getInit();
2028
2029 // If we are at an unreachable point, we don't need to emit the initializer
2030 // unless it contains a label.
2031 if (!HaveInsertPoint()) {
2032 if (!Init || !ContainsLabel(S: Init)) {
2033 PGO->markStmtMaybeUsed(S: Init);
2034 return;
2035 }
2036 EnsureInsertPoint();
2037 }
2038
2039 // Initialize the structure of a __block variable.
2040 if (emission.IsEscapingByRef)
2041 emitByrefStructureInit(emission);
2042
2043 // Initialize the variable here if it doesn't have a initializer and it is a
2044 // C struct that is non-trivial to initialize or an array containing such a
2045 // struct.
2046 if (!Init &&
2047 type.isNonTrivialToPrimitiveDefaultInitialize() ==
2048 QualType::PDIK_Struct) {
2049 LValue Dst = MakeAddrLValue(Addr: emission.getAllocatedAddress(), T: type);
2050 if (emission.IsEscapingByRef)
2051 drillIntoBlockVariable(CGF&: *this, lvalue&: Dst, var: &D);
2052 defaultInitNonTrivialCStructVar(Dst);
2053 return;
2054 }
2055
2056 // Check whether this is a byref variable that's potentially
2057 // captured and moved by its own initializer. If so, we'll need to
2058 // emit the initializer first, then copy into the variable.
2059 bool capturedByInit =
2060 Init && emission.IsEscapingByRef && isCapturedBy(Var: D, E: Init);
2061
2062 bool locIsByrefHeader = !capturedByInit;
2063 const Address Loc =
2064 locIsByrefHeader ? emission.getObjectAddress(CGF&: *this) : emission.Addr;
2065
2066 // Note: constexpr already initializes everything correctly.
2067 LangOptions::TrivialAutoVarInitKind trivialAutoVarInit =
2068 getAutoVarInitKind(Ty: type, D);
2069
2070 auto initializeWhatIsTechnicallyUninitialized = [&](Address Loc) {
2071 if (trivialAutoVarInit ==
2072 LangOptions::TrivialAutoVarInitKind::Uninitialized)
2073 return;
2074
2075 // Only initialize a __block's storage: we always initialize the header.
2076 if (emission.IsEscapingByRef && !locIsByrefHeader)
2077 Loc = emitBlockByrefAddress(baseAddr: Loc, V: &D, /*follow=*/followForward: false);
2078
2079 return emitZeroOrPatternForAutoVarInit(type, D, Loc);
2080 };
2081
2082 if (isTrivialInitializer(Init))
2083 return initializeWhatIsTechnicallyUninitialized(Loc);
2084
2085 llvm::Constant *constant = nullptr;
2086 if (emission.ConstantAggregateInitializer ||
2087 D.mightBeUsableInConstantExpressions(C: getContext())) {
2088 assert(!capturedByInit && "constant init contains a capturing block?");
2089 if (emission.ConstantAggregateInitializer)
2090 constant = emission.ConstantAggregateInitializer;
2091 else
2092 constant = ConstantEmitter(*this).tryEmitAbstractForInitializer(D);
2093 if (constant && !constant->isNullValue() &&
2094 (trivialAutoVarInit !=
2095 LangOptions::TrivialAutoVarInitKind::Uninitialized)) {
2096 IsPattern isPattern =
2097 (trivialAutoVarInit == LangOptions::TrivialAutoVarInitKind::Pattern)
2098 ? IsPattern::Yes
2099 : IsPattern::No;
2100 // C guarantees that brace-init with fewer initializers than members in
2101 // the aggregate will initialize the rest of the aggregate as-if it were
2102 // static initialization. In turn static initialization guarantees that
2103 // padding is initialized to zero bits. We could instead pattern-init if D
2104 // has any ImplicitValueInitExpr, but that seems to be unintuitive
2105 // behavior.
2106 constant = constWithPadding(CGM, isPattern: IsPattern::No,
2107 constant: replaceUndef(CGM, isPattern, constant));
2108 }
2109
2110 if (constant && type->isBitIntType() &&
2111 CGM.getTypes().typeRequiresSplitIntoByteArray(ASTTy: type)) {
2112 // Constants for long _BitInt types are split into individual bytes.
2113 // Try to fold these back into an integer constant so it can be stored
2114 // properly.
2115 llvm::Type *LoadType =
2116 CGM.getTypes().convertTypeForLoadStore(T: type, LLVMTy: constant->getType());
2117 constant = llvm::ConstantFoldLoadFromConst(
2118 C: constant, Ty: LoadType, Offset: llvm::APInt::getZero(numBits: 32), DL: CGM.getDataLayout());
2119 }
2120 }
2121
2122 if (!constant) {
2123 if (trivialAutoVarInit !=
2124 LangOptions::TrivialAutoVarInitKind::Uninitialized) {
2125 // At this point, we know D has an Init expression, but isn't a constant.
2126 // - If D is not a scalar, auto-var-init conservatively (members may be
2127 // left uninitialized by constructor Init expressions for example).
2128 // - If D is a scalar, we only need to auto-var-init if there is a
2129 // self-reference. Otherwise, the Init expression should be sufficient.
2130 // It may be that the Init expression uses other uninitialized memory,
2131 // but auto-var-init here would not help, as auto-init would get
2132 // overwritten by Init.
2133 if (!type->isScalarType() || capturedByInit || isAccessedBy(var: D, s: Init)) {
2134 initializeWhatIsTechnicallyUninitialized(Loc);
2135 }
2136 }
2137 LValue lv = MakeAddrLValue(Addr: Loc, T: type);
2138 lv.setNonGC(true);
2139 return EmitExprAsInit(init: Init, D: &D, lvalue: lv, capturedByInit);
2140 }
2141
2142 PGO->markStmtMaybeUsed(S: Init);
2143
2144 if (!emission.ConstantAggregateInitializer) {
2145 // For simple scalar/complex initialization, store the value directly.
2146 LValue lv = MakeAddrLValue(Addr: Loc, T: type);
2147 lv.setNonGC(true);
2148 return EmitStoreThroughLValue(Src: RValue::get(V: constant), Dst: lv, isInit: true);
2149 }
2150
2151 emitStoresForConstant(D, Loc: Loc.withElementType(ElemTy: CGM.Int8Ty),
2152 isVolatile: type.isVolatileQualified(), constant,
2153 /*IsAutoInit=*/false);
2154}
2155
2156void CodeGenFunction::MaybeEmitDeferredVarDeclInit(const VarDecl *VD) {
2157 if (auto *DD = dyn_cast_if_present<DecompositionDecl>(Val: VD)) {
2158 for (auto *B : DD->flat_bindings())
2159 if (auto *HD = B->getHoldingVar())
2160 EmitVarDecl(D: *HD);
2161 }
2162}
2163
2164/// Emit an expression as an initializer for an object (variable, field, etc.)
2165/// at the given location. The expression is not necessarily the normal
2166/// initializer for the object, and the address is not necessarily
2167/// its normal location.
2168///
2169/// \param init the initializing expression
2170/// \param D the object to act as if we're initializing
2171/// \param lvalue the lvalue to initialize
2172/// \param capturedByInit true if \p D is a __block variable
2173/// whose address is potentially changed by the initializer
2174void CodeGenFunction::EmitExprAsInit(const Expr *init, const ValueDecl *D,
2175 LValue lvalue, bool capturedByInit) {
2176 QualType type = D->getType();
2177
2178 if (type->isReferenceType()) {
2179 RValue rvalue = EmitReferenceBindingToExpr(E: init);
2180 if (capturedByInit)
2181 drillIntoBlockVariable(CGF&: *this, lvalue, var: cast<VarDecl>(Val: D));
2182 EmitStoreThroughLValue(Src: rvalue, Dst: lvalue, isInit: true);
2183 return;
2184 }
2185 switch (getEvaluationKind(T: type)) {
2186 case TEK_Scalar:
2187 EmitScalarInit(init, D, lvalue, capturedByInit);
2188 return;
2189 case TEK_Complex: {
2190 ComplexPairTy complex = EmitComplexExpr(E: init);
2191 if (capturedByInit)
2192 drillIntoBlockVariable(CGF&: *this, lvalue, var: cast<VarDecl>(Val: D));
2193 EmitStoreOfComplex(V: complex, dest: lvalue, /*init*/ isInit: true);
2194 return;
2195 }
2196 case TEK_Aggregate:
2197 if (type->isAtomicType()) {
2198 EmitAtomicInit(E: const_cast<Expr*>(init), lvalue);
2199 } else {
2200 AggValueSlot::Overlap_t Overlap = AggValueSlot::MayOverlap;
2201 if (isa<VarDecl>(Val: D))
2202 Overlap = AggValueSlot::DoesNotOverlap;
2203 else if (auto *FD = dyn_cast<FieldDecl>(Val: D))
2204 Overlap = getOverlapForFieldInit(FD);
2205 // TODO: how can we delay here if D is captured by its initializer?
2206 EmitAggExpr(E: init,
2207 AS: AggValueSlot::forLValue(LV: lvalue, isDestructed: AggValueSlot::IsDestructed,
2208 needsGC: AggValueSlot::DoesNotNeedGCBarriers,
2209 isAliased: AggValueSlot::IsNotAliased, mayOverlap: Overlap));
2210 }
2211 return;
2212 }
2213 llvm_unreachable("bad evaluation kind");
2214}
2215
2216/// Enter a destroy cleanup for the given local variable.
2217void CodeGenFunction::emitAutoVarTypeCleanup(
2218 const CodeGenFunction::AutoVarEmission &emission,
2219 QualType::DestructionKind dtorKind) {
2220 assert(dtorKind != QualType::DK_none);
2221
2222 // Note that for __block variables, we want to destroy the
2223 // original stack object, not the possibly forwarded object.
2224 Address addr = emission.getObjectAddress(CGF&: *this);
2225
2226 const VarDecl *var = emission.Variable;
2227 QualType type = var->getType();
2228
2229 CleanupKind cleanupKind = NormalAndEHCleanup;
2230 CodeGenFunction::Destroyer *destroyer = nullptr;
2231
2232 switch (dtorKind) {
2233 case QualType::DK_none:
2234 llvm_unreachable("no cleanup for trivially-destructible variable");
2235
2236 case QualType::DK_cxx_destructor:
2237 // If there's an NRVO flag on the emission, we need a different
2238 // cleanup.
2239 if (emission.NRVOFlag) {
2240 assert(!type->isArrayType());
2241 CXXDestructorDecl *dtor = type->getAsCXXRecordDecl()->getDestructor();
2242 EHStack.pushCleanup<DestroyNRVOVariableCXX>(Kind: cleanupKind, A: addr, A: type, A: dtor,
2243 A: emission.NRVOFlag);
2244 return;
2245 }
2246 break;
2247
2248 case QualType::DK_objc_strong_lifetime:
2249 // Suppress cleanups for pseudo-strong variables.
2250 if (var->isARCPseudoStrong()) return;
2251
2252 // Otherwise, consider whether to use an EH cleanup or not.
2253 cleanupKind = getARCCleanupKind();
2254
2255 // Use the imprecise destroyer by default.
2256 if (!var->hasAttr<ObjCPreciseLifetimeAttr>())
2257 destroyer = CodeGenFunction::destroyARCStrongImprecise;
2258 break;
2259
2260 case QualType::DK_objc_weak_lifetime:
2261 break;
2262
2263 case QualType::DK_nontrivial_c_struct:
2264 destroyer = CodeGenFunction::destroyNonTrivialCStruct;
2265 if (emission.NRVOFlag) {
2266 assert(!type->isArrayType());
2267 EHStack.pushCleanup<DestroyNRVOVariableC>(Kind: cleanupKind, A: addr,
2268 A: emission.NRVOFlag, A: type);
2269 return;
2270 }
2271 break;
2272 }
2273
2274 // If we haven't chosen a more specific destroyer, use the default.
2275 if (!destroyer) destroyer = getDestroyer(destructionKind: dtorKind);
2276
2277 // Use an EH cleanup in array destructors iff the destructor itself
2278 // is being pushed as an EH cleanup.
2279 bool useEHCleanup = (cleanupKind & EHCleanup);
2280 EHStack.pushCleanup<DestroyObject>(Kind: cleanupKind, A: addr, A: type, A: destroyer,
2281 A: useEHCleanup);
2282}
2283
2284void CodeGenFunction::EmitAutoVarCleanups(const AutoVarEmission &emission) {
2285 assert(emission.Variable && "emission was not valid!");
2286
2287 // If this was emitted as a global constant, we're done.
2288 if (emission.wasEmittedAsGlobal()) return;
2289
2290 // If we don't have an insertion point, we're done. Sema prevents
2291 // us from jumping into any of these scopes anyway.
2292 if (!HaveInsertPoint()) return;
2293
2294 const VarDecl &D = *emission.Variable;
2295
2296 // Check the type for a cleanup.
2297 if (QualType::DestructionKind dtorKind = D.needsDestruction(Ctx: getContext())) {
2298 // Check if we're in a SEH block with /EH, prevent it
2299 if (getLangOpts().CXXExceptions && currentFunctionUsesSEHTry())
2300 getContext().getDiagnostics().Report(Loc: D.getLocation(),
2301 DiagID: diag::err_seh_object_unwinding);
2302 emitAutoVarTypeCleanup(emission, dtorKind);
2303 }
2304
2305 // In GC mode, honor objc_precise_lifetime.
2306 if (getLangOpts().getGC() != LangOptions::NonGC &&
2307 D.hasAttr<ObjCPreciseLifetimeAttr>()) {
2308 EHStack.pushCleanup<ExtendGCLifetime>(Kind: NormalCleanup, A: &D);
2309 }
2310
2311 // Handle the cleanup attribute.
2312 if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) {
2313 const FunctionDecl *FD = CA->getFunctionDecl();
2314
2315 llvm::Constant *F = CGM.GetAddrOfFunction(GD: FD);
2316 assert(F && "Could not find function!");
2317
2318 const CGFunctionInfo &Info = CGM.getTypes().arrangeFunctionDeclaration(GD: FD);
2319 EHStack.pushCleanup<CallCleanupFunction>(Kind: NormalAndEHCleanup, A: F, A: &Info, A: &D,
2320 A: CA);
2321 }
2322
2323 // If this is a block variable, call _Block_object_destroy
2324 // (on the unforwarded address). Don't enter this cleanup if we're in pure-GC
2325 // mode.
2326 if (emission.IsEscapingByRef &&
2327 CGM.getLangOpts().getGC() != LangOptions::GCOnly) {
2328 BlockFieldFlags Flags = BLOCK_FIELD_IS_BYREF;
2329 if (emission.Variable->getType().isObjCGCWeak())
2330 Flags |= BLOCK_FIELD_IS_WEAK;
2331 enterByrefCleanup(Kind: NormalAndEHCleanup, Addr: emission.Addr, Flags,
2332 /*LoadBlockVarAddr*/ false,
2333 CanThrow: cxxDestructorCanThrow(T: emission.Variable->getType()));
2334 }
2335}
2336
2337CodeGenFunction::Destroyer *
2338CodeGenFunction::getDestroyer(QualType::DestructionKind kind) {
2339 switch (kind) {
2340 case QualType::DK_none: llvm_unreachable("no destroyer for trivial dtor");
2341 case QualType::DK_cxx_destructor:
2342 return destroyCXXObject;
2343 case QualType::DK_objc_strong_lifetime:
2344 return destroyARCStrongPrecise;
2345 case QualType::DK_objc_weak_lifetime:
2346 return destroyARCWeak;
2347 case QualType::DK_nontrivial_c_struct:
2348 return destroyNonTrivialCStruct;
2349 }
2350 llvm_unreachable("Unknown DestructionKind");
2351}
2352
2353/// pushEHDestroy - Push the standard destructor for the given type as
2354/// an EH-only cleanup.
2355void CodeGenFunction::pushEHDestroy(QualType::DestructionKind dtorKind,
2356 Address addr, QualType type) {
2357 assert(dtorKind && "cannot push destructor for trivial type");
2358 assert(needsEHCleanup(dtorKind));
2359
2360 pushDestroy(kind: EHCleanup, addr, type, destroyer: getDestroyer(kind: dtorKind), useEHCleanupForArray: true);
2361}
2362
2363/// pushDestroy - Push the standard destructor for the given type as
2364/// at least a normal cleanup.
2365void CodeGenFunction::pushDestroy(QualType::DestructionKind dtorKind,
2366 Address addr, QualType type) {
2367 assert(dtorKind && "cannot push destructor for trivial type");
2368
2369 CleanupKind cleanupKind = getCleanupKind(kind: dtorKind);
2370 pushDestroy(kind: cleanupKind, addr, type, destroyer: getDestroyer(kind: dtorKind),
2371 useEHCleanupForArray: cleanupKind & EHCleanup);
2372}
2373
2374void CodeGenFunction::pushLifetimeExtendedDestroy(
2375 QualType::DestructionKind dtorKind, Address addr, QualType type) {
2376 CleanupKind cleanupKind = getCleanupKind(kind: dtorKind);
2377 pushLifetimeExtendedDestroy(kind: cleanupKind, addr, type, destroyer: getDestroyer(kind: dtorKind),
2378 useEHCleanupForArray: cleanupKind & EHCleanup);
2379}
2380
2381void CodeGenFunction::pushDestroy(CleanupKind cleanupKind, Address addr,
2382 QualType type, Destroyer *destroyer,
2383 bool useEHCleanupForArray) {
2384 pushFullExprCleanup<DestroyObject>(kind: cleanupKind, A: addr, A: type, A: destroyer,
2385 A: useEHCleanupForArray);
2386}
2387
2388// Pushes a destroy and defers its deactivation until its
2389// CleanupDeactivationScope is exited.
2390void CodeGenFunction::pushDestroyAndDeferDeactivation(
2391 QualType::DestructionKind dtorKind, Address addr, QualType type) {
2392 assert(dtorKind && "cannot push destructor for trivial type");
2393
2394 CleanupKind cleanupKind = getCleanupKind(kind: dtorKind);
2395 pushDestroyAndDeferDeactivation(
2396 cleanupKind, addr, type, destroyer: getDestroyer(kind: dtorKind), useEHCleanupForArray: cleanupKind & EHCleanup);
2397}
2398
2399void CodeGenFunction::pushDestroyAndDeferDeactivation(
2400 CleanupKind cleanupKind, Address addr, QualType type, Destroyer *destroyer,
2401 bool useEHCleanupForArray) {
2402 llvm::Instruction *DominatingIP =
2403 Builder.CreateFlagLoad(Addr: llvm::Constant::getNullValue(Ty: Int8PtrTy));
2404 pushDestroy(cleanupKind, addr, type, destroyer, useEHCleanupForArray);
2405 DeferredDeactivationCleanupStack.push_back(
2406 Elt: {.Cleanup: EHStack.stable_begin(), .DominatingIP: DominatingIP});
2407}
2408
2409void CodeGenFunction::pushStackRestore(CleanupKind Kind, Address SPMem) {
2410 EHStack.pushCleanup<CallStackRestore>(
2411 Kind: static_cast<CleanupKind>(Kind | StackRestore), A: SPMem);
2412}
2413
2414void CodeGenFunction::pushKmpcAllocFree(
2415 CleanupKind Kind, std::pair<llvm::Value *, llvm::Value *> AddrSizePair) {
2416 EHStack.pushCleanup<KmpcAllocFree>(Kind, A: AddrSizePair);
2417}
2418
2419void CodeGenFunction::pushLifetimeExtendedDestroy(CleanupKind cleanupKind,
2420 Address addr, QualType type,
2421 Destroyer *destroyer,
2422 bool useEHCleanupForArray) {
2423 // If we're not in a conditional branch, we don't need to bother generating a
2424 // conditional cleanup.
2425 if (!isInConditionalBranch()) {
2426 // FIXME: When popping normal cleanups, we need to keep this EH cleanup
2427 // around in case a temporary's destructor throws an exception.
2428
2429 // Add the cleanup to the EHStack. After the full-expr, this would be
2430 // deactivated before being popped from the stack.
2431 pushDestroyAndDeferDeactivation(cleanupKind, addr, type, destroyer,
2432 useEHCleanupForArray);
2433
2434 // Since this is lifetime-extended, push it once again to the EHStack after
2435 // the full expression.
2436 return pushCleanupAfterFullExprWithActiveFlag<DestroyObject>(
2437 Kind: cleanupKind, ActiveFlag: Address::invalid(), A: addr, A: type, A: destroyer,
2438 A: useEHCleanupForArray);
2439 }
2440
2441 // Otherwise, we should only destroy the object if it's been initialized.
2442
2443 using ConditionalCleanupType =
2444 EHScopeStack::ConditionalCleanup<DestroyObject, Address, QualType,
2445 Destroyer *, bool>;
2446 DominatingValue<Address>::saved_type SavedAddr = saveValueInCond(value: addr);
2447
2448 // Remember to emit cleanup if we branch-out before end of full-expression
2449 // (eg: through stmt-expr or coro suspensions).
2450 AllocaTrackerRAII DeactivationAllocas(*this);
2451 Address ActiveFlagForDeactivation = createCleanupActiveFlag();
2452
2453 pushCleanupAndDeferDeactivation<ConditionalCleanupType>(
2454 Kind: cleanupKind, A: SavedAddr, A: type, A: destroyer, A: useEHCleanupForArray);
2455 initFullExprCleanupWithFlag(ActiveFlag: ActiveFlagForDeactivation);
2456 EHCleanupScope &cleanup = cast<EHCleanupScope>(Val&: *EHStack.begin());
2457 // Erase the active flag if the cleanup was not emitted.
2458 cleanup.AddAuxAllocas(Allocas: std::move(DeactivationAllocas).Take());
2459
2460 // Since this is lifetime-extended, push it once again to the EHStack after
2461 // the full expression.
2462 // The previous active flag would always be 'false' due to forced deferred
2463 // deactivation. Use a separate flag for lifetime-extension to correctly
2464 // remember if this branch was taken and the object was initialized.
2465 Address ActiveFlagForLifetimeExt = createCleanupActiveFlag();
2466 pushCleanupAfterFullExprWithActiveFlag<ConditionalCleanupType>(
2467 Kind: cleanupKind, ActiveFlag: ActiveFlagForLifetimeExt, A: SavedAddr, A: type, A: destroyer,
2468 A: useEHCleanupForArray);
2469}
2470
2471/// emitDestroy - Immediately perform the destruction of the given
2472/// object.
2473///
2474/// \param addr - the address of the object; a type*
2475/// \param type - the type of the object; if an array type, all
2476/// objects are destroyed in reverse order
2477/// \param destroyer - the function to call to destroy individual
2478/// elements
2479/// \param useEHCleanupForArray - whether an EH cleanup should be
2480/// used when destroying array elements, in case one of the
2481/// destructions throws an exception
2482void CodeGenFunction::emitDestroy(Address addr, QualType type,
2483 Destroyer *destroyer,
2484 bool useEHCleanupForArray) {
2485 const ArrayType *arrayType = getContext().getAsArrayType(T: type);
2486 if (!arrayType)
2487 return destroyer(*this, addr, type);
2488
2489 llvm::Value *length = emitArrayLength(arrayType, baseType&: type, addr);
2490
2491 CharUnits elementAlign =
2492 addr.getAlignment()
2493 .alignmentOfArrayElement(elementSize: getContext().getTypeSizeInChars(T: type));
2494
2495 // Normally we have to check whether the array is zero-length.
2496 bool checkZeroLength = true;
2497
2498 // But if the array length is constant, we can suppress that.
2499 if (llvm::ConstantInt *constLength = dyn_cast<llvm::ConstantInt>(Val: length)) {
2500 // ...and if it's constant zero, we can just skip the entire thing.
2501 if (constLength->isZero()) return;
2502 checkZeroLength = false;
2503 }
2504
2505 llvm::Value *begin = addr.emitRawPointer(CGF&: *this);
2506 llvm::Value *end =
2507 Builder.CreateInBoundsGEP(Ty: addr.getElementType(), Ptr: begin, IdxList: length);
2508 emitArrayDestroy(begin, end, elementType: type, elementAlign, destroyer,
2509 checkZeroLength, useEHCleanup: useEHCleanupForArray);
2510}
2511
2512/// emitArrayDestroy - Destroys all the elements of the given array,
2513/// beginning from last to first. The array cannot be zero-length.
2514///
2515/// \param begin - a type* denoting the first element of the array
2516/// \param end - a type* denoting one past the end of the array
2517/// \param elementType - the element type of the array
2518/// \param destroyer - the function to call to destroy elements
2519/// \param useEHCleanup - whether to push an EH cleanup to destroy
2520/// the remaining elements in case the destruction of a single
2521/// element throws
2522void CodeGenFunction::emitArrayDestroy(llvm::Value *begin,
2523 llvm::Value *end,
2524 QualType elementType,
2525 CharUnits elementAlign,
2526 Destroyer *destroyer,
2527 bool checkZeroLength,
2528 bool useEHCleanup) {
2529 assert(!elementType->isArrayType());
2530
2531 // The basic structure here is a do-while loop, because we don't
2532 // need to check for the zero-element case.
2533 llvm::BasicBlock *bodyBB = createBasicBlock(name: "arraydestroy.body");
2534 llvm::BasicBlock *doneBB = createBasicBlock(name: "arraydestroy.done");
2535
2536 if (checkZeroLength) {
2537 llvm::Value *isEmpty = Builder.CreateICmpEQ(LHS: begin, RHS: end,
2538 Name: "arraydestroy.isempty");
2539 Builder.CreateCondBr(Cond: isEmpty, True: doneBB, False: bodyBB);
2540 }
2541
2542 // Enter the loop body, making that address the current address.
2543 llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
2544 EmitBlock(BB: bodyBB);
2545 llvm::PHINode *elementPast =
2546 Builder.CreatePHI(Ty: begin->getType(), NumReservedValues: 2, Name: "arraydestroy.elementPast");
2547 elementPast->addIncoming(V: end, BB: entryBB);
2548
2549 // Shift the address back by one element.
2550 llvm::Value *negativeOne = llvm::ConstantInt::get(Ty: SizeTy, V: -1, IsSigned: true);
2551 llvm::Type *llvmElementType = ConvertTypeForMem(T: elementType);
2552 llvm::Value *element = Builder.CreateInBoundsGEP(
2553 Ty: llvmElementType, Ptr: elementPast, IdxList: negativeOne, Name: "arraydestroy.element");
2554
2555 if (useEHCleanup)
2556 pushRegularPartialArrayCleanup(arrayBegin: begin, arrayEnd: element, elementType, elementAlignment: elementAlign,
2557 destroyer);
2558
2559 // Perform the actual destruction there.
2560 destroyer(*this, Address(element, llvmElementType, elementAlign),
2561 elementType);
2562
2563 if (useEHCleanup)
2564 PopCleanupBlock();
2565
2566 // Check whether we've reached the end.
2567 llvm::Value *done = Builder.CreateICmpEQ(LHS: element, RHS: begin, Name: "arraydestroy.done");
2568 Builder.CreateCondBr(Cond: done, True: doneBB, False: bodyBB);
2569 elementPast->addIncoming(V: element, BB: Builder.GetInsertBlock());
2570
2571 // Done.
2572 EmitBlock(BB: doneBB);
2573}
2574
2575/// Perform partial array destruction as if in an EH cleanup. Unlike
2576/// emitArrayDestroy, the element type here may still be an array type.
2577static void emitPartialArrayDestroy(CodeGenFunction &CGF,
2578 llvm::Value *begin, llvm::Value *end,
2579 QualType type, CharUnits elementAlign,
2580 CodeGenFunction::Destroyer *destroyer) {
2581 llvm::Type *elemTy = CGF.ConvertTypeForMem(T: type);
2582
2583 // If the element type is itself an array, drill down.
2584 unsigned arrayDepth = 0;
2585 while (const ArrayType *arrayType = CGF.getContext().getAsArrayType(T: type)) {
2586 // VLAs don't require a GEP index to walk into.
2587 if (!isa<VariableArrayType>(Val: arrayType))
2588 arrayDepth++;
2589 type = arrayType->getElementType();
2590 }
2591
2592 if (arrayDepth) {
2593 llvm::Value *zero = llvm::ConstantInt::get(Ty: CGF.SizeTy, V: 0);
2594
2595 SmallVector<llvm::Value*,4> gepIndices(arrayDepth+1, zero);
2596 begin = CGF.Builder.CreateInBoundsGEP(
2597 Ty: elemTy, Ptr: begin, IdxList: gepIndices, Name: "pad.arraybegin");
2598 end = CGF.Builder.CreateInBoundsGEP(
2599 Ty: elemTy, Ptr: end, IdxList: gepIndices, Name: "pad.arrayend");
2600 }
2601
2602 // Destroy the array. We don't ever need an EH cleanup because we
2603 // assume that we're in an EH cleanup ourselves, so a throwing
2604 // destructor causes an immediate terminate.
2605 CGF.emitArrayDestroy(begin, end, elementType: type, elementAlign, destroyer,
2606 /*checkZeroLength*/ true, /*useEHCleanup*/ false);
2607}
2608
2609namespace {
2610 /// RegularPartialArrayDestroy - a cleanup which performs a partial
2611 /// array destroy where the end pointer is regularly determined and
2612 /// does not need to be loaded from a local.
2613 class RegularPartialArrayDestroy final : public EHScopeStack::Cleanup {
2614 llvm::Value *ArrayBegin;
2615 llvm::Value *ArrayEnd;
2616 QualType ElementType;
2617 CodeGenFunction::Destroyer *Destroyer;
2618 CharUnits ElementAlign;
2619 public:
2620 RegularPartialArrayDestroy(llvm::Value *arrayBegin, llvm::Value *arrayEnd,
2621 QualType elementType, CharUnits elementAlign,
2622 CodeGenFunction::Destroyer *destroyer)
2623 : ArrayBegin(arrayBegin), ArrayEnd(arrayEnd),
2624 ElementType(elementType), Destroyer(destroyer),
2625 ElementAlign(elementAlign) {}
2626
2627 void Emit(CodeGenFunction &CGF, Flags flags) override {
2628 emitPartialArrayDestroy(CGF, begin: ArrayBegin, end: ArrayEnd,
2629 type: ElementType, elementAlign: ElementAlign, destroyer: Destroyer);
2630 }
2631 };
2632
2633 /// IrregularPartialArrayDestroy - a cleanup which performs a
2634 /// partial array destroy where the end pointer is irregularly
2635 /// determined and must be loaded from a local.
2636 class IrregularPartialArrayDestroy final : public EHScopeStack::Cleanup {
2637 llvm::Value *ArrayBegin;
2638 Address ArrayEndPointer;
2639 QualType ElementType;
2640 CodeGenFunction::Destroyer *Destroyer;
2641 CharUnits ElementAlign;
2642 public:
2643 IrregularPartialArrayDestroy(llvm::Value *arrayBegin,
2644 Address arrayEndPointer,
2645 QualType elementType,
2646 CharUnits elementAlign,
2647 CodeGenFunction::Destroyer *destroyer)
2648 : ArrayBegin(arrayBegin), ArrayEndPointer(arrayEndPointer),
2649 ElementType(elementType), Destroyer(destroyer),
2650 ElementAlign(elementAlign) {}
2651
2652 void Emit(CodeGenFunction &CGF, Flags flags) override {
2653 llvm::Value *arrayEnd = CGF.Builder.CreateLoad(Addr: ArrayEndPointer);
2654 emitPartialArrayDestroy(CGF, begin: ArrayBegin, end: arrayEnd,
2655 type: ElementType, elementAlign: ElementAlign, destroyer: Destroyer);
2656 }
2657 };
2658} // end anonymous namespace
2659
2660/// pushIrregularPartialArrayCleanup - Push a NormalAndEHCleanup to
2661/// destroy already-constructed elements of the given array. The cleanup may be
2662/// popped with DeactivateCleanupBlock or PopCleanupBlock.
2663///
2664/// \param elementType - the immediate element type of the array;
2665/// possibly still an array type
2666void CodeGenFunction::pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin,
2667 Address arrayEndPointer,
2668 QualType elementType,
2669 CharUnits elementAlign,
2670 Destroyer *destroyer) {
2671 pushFullExprCleanup<IrregularPartialArrayDestroy>(
2672 kind: NormalAndEHCleanup, A: arrayBegin, A: arrayEndPointer, A: elementType,
2673 A: elementAlign, A: destroyer);
2674}
2675
2676/// pushRegularPartialArrayCleanup - Push an EH cleanup to destroy
2677/// already-constructed elements of the given array. The cleanup
2678/// may be popped with DeactivateCleanupBlock or PopCleanupBlock.
2679///
2680/// \param elementType - the immediate element type of the array;
2681/// possibly still an array type
2682void CodeGenFunction::pushRegularPartialArrayCleanup(llvm::Value *arrayBegin,
2683 llvm::Value *arrayEnd,
2684 QualType elementType,
2685 CharUnits elementAlign,
2686 Destroyer *destroyer) {
2687 pushFullExprCleanup<RegularPartialArrayDestroy>(kind: EHCleanup,
2688 A: arrayBegin, A: arrayEnd,
2689 A: elementType, A: elementAlign,
2690 A: destroyer);
2691}
2692
2693/// Lazily declare the @llvm.lifetime.start intrinsic.
2694llvm::Function *CodeGenModule::getLLVMLifetimeStartFn() {
2695 if (LifetimeStartFn)
2696 return LifetimeStartFn;
2697 LifetimeStartFn = llvm::Intrinsic::getOrInsertDeclaration(
2698 M: &getModule(), id: llvm::Intrinsic::lifetime_start, OverloadTys: AllocaInt8PtrTy);
2699 return LifetimeStartFn;
2700}
2701
2702/// Lazily declare the @llvm.lifetime.end intrinsic.
2703llvm::Function *CodeGenModule::getLLVMLifetimeEndFn() {
2704 if (LifetimeEndFn)
2705 return LifetimeEndFn;
2706 LifetimeEndFn = llvm::Intrinsic::getOrInsertDeclaration(
2707 M: &getModule(), id: llvm::Intrinsic::lifetime_end, OverloadTys: AllocaInt8PtrTy);
2708 return LifetimeEndFn;
2709}
2710
2711/// Lazily declare the @llvm.fake.use intrinsic.
2712llvm::Function *CodeGenModule::getLLVMFakeUseFn() {
2713 if (FakeUseFn)
2714 return FakeUseFn;
2715 FakeUseFn = llvm::Intrinsic::getOrInsertDeclaration(
2716 M: &getModule(), id: llvm::Intrinsic::fake_use);
2717 return FakeUseFn;
2718}
2719
2720namespace {
2721 /// A cleanup to perform a release of an object at the end of a
2722 /// function. This is used to balance out the incoming +1 of a
2723 /// ns_consumed argument when we can't reasonably do that just by
2724 /// not doing the initial retain for a __block argument.
2725 struct ConsumeARCParameter final : EHScopeStack::Cleanup {
2726 ConsumeARCParameter(llvm::Value *param,
2727 ARCPreciseLifetime_t precise)
2728 : Param(param), Precise(precise) {}
2729
2730 llvm::Value *Param;
2731 ARCPreciseLifetime_t Precise;
2732
2733 void Emit(CodeGenFunction &CGF, Flags flags) override {
2734 CGF.EmitARCRelease(value: Param, precise: Precise);
2735 }
2736 };
2737} // end anonymous namespace
2738
2739/// Emit an alloca (or GlobalValue depending on target)
2740/// for the specified parameter and set up LocalDeclMap.
2741void CodeGenFunction::EmitParmDecl(const VarDecl &D, ParamValue Arg,
2742 unsigned ArgNo) {
2743 bool NoDebugInfo = false;
2744 // FIXME: Why isn't ImplicitParamDecl a ParmVarDecl?
2745 assert((isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)) &&
2746 "Invalid argument to EmitParmDecl");
2747
2748 // Set the name of the parameter's initial value to make IR easier to
2749 // read. Don't modify the names of globals.
2750 if (!isa<llvm::GlobalValue>(Val: Arg.getAnyValue()))
2751 Arg.getAnyValue()->setName(D.getName());
2752
2753 QualType Ty = D.getType();
2754 assert((getLangOpts().OpenCL || Ty.getAddressSpace() == LangAS::Default) &&
2755 "parameter has non-default address space in non-OpenCL mode");
2756
2757 // Use better IR generation for certain implicit parameters.
2758 if (auto IPD = dyn_cast<ImplicitParamDecl>(Val: &D)) {
2759 // The only implicit argument a block has is its literal.
2760 // This may be passed as an inalloca'ed value on Windows x86.
2761 if (BlockInfo) {
2762 llvm::Value *V = Arg.isIndirect()
2763 ? Builder.CreateLoad(Addr: Arg.getIndirectAddress())
2764 : Arg.getDirectValue();
2765 setBlockContextParameter(D: IPD, argNum: ArgNo, ptr: V);
2766 return;
2767 }
2768 // Suppressing debug info for ThreadPrivateVar parameters, else it hides
2769 // debug info of TLS variables.
2770 NoDebugInfo =
2771 (IPD->getParameterKind() == ImplicitParamKind::ThreadPrivateVar);
2772 }
2773
2774 Address DeclPtr = Address::invalid();
2775 RawAddress AllocaPtr = Address::invalid();
2776 bool DoStore = false;
2777 bool IsScalar = hasScalarEvaluationKind(T: Ty);
2778 bool UseIndirectDebugAddress = false;
2779
2780 // If we already have a pointer to the argument, reuse the input pointer.
2781 if (Arg.isIndirect()) {
2782 DeclPtr = Arg.getIndirectAddress();
2783 DeclPtr = DeclPtr.withElementType(ElemTy: ConvertTypeForMem(T: Ty));
2784 auto *V = DeclPtr.emitRawPointer(CGF&: *this);
2785 AllocaPtr = RawAddress(V, DeclPtr.getElementType(), DeclPtr.getAlignment());
2786
2787 // For truly ABI indirect arguments -- those that are not `byval` -- store
2788 // the address of the argument on the stack to preserve debug information.
2789 ABIArgInfo ArgInfo = CurFnInfo->arguments()[ArgNo - 1].info;
2790 if (ArgInfo.isIndirect())
2791 UseIndirectDebugAddress = !ArgInfo.getIndirectByVal();
2792 if (UseIndirectDebugAddress) {
2793 auto PtrTy = getContext().getPointerType(T: Ty);
2794 AllocaPtr = CreateMemTempWithoutCast(
2795 T: PtrTy, Align: getContext().getTypeAlignInChars(T: PtrTy),
2796 Name: D.getName() + ".indirect_addr");
2797 EmitStoreOfScalar(Value: V, Addr: AllocaPtr, /* Volatile */ false, Ty: PtrTy);
2798 }
2799
2800 LangAS DestLangAS = Ty.getAddressSpace();
2801 unsigned DestAS = getContext().getTargetAddressSpace(AS: DestLangAS);
2802 if (DeclPtr.getAddressSpace() != DestAS) {
2803 auto *T = llvm::PointerType::get(C&: getLLVMContext(), AddressSpace: DestAS);
2804 DeclPtr = DeclPtr.withPointer(NewPointer: performAddrSpaceCast(Src: V, DestTy: T),
2805 IsKnownNonNull: DeclPtr.isKnownNonNull());
2806 }
2807
2808 // Push a destructor cleanup for this parameter if the ABI requires it.
2809 // Don't push a cleanup in a thunk for a method that will also emit a
2810 // cleanup.
2811 if (Ty->isRecordType() && !CurFuncIsThunk &&
2812 Ty->castAsRecordDecl()->isParamDestroyedInCallee()) {
2813 if (QualType::DestructionKind DtorKind =
2814 D.needsDestruction(Ctx: getContext())) {
2815 assert((DtorKind == QualType::DK_cxx_destructor ||
2816 DtorKind == QualType::DK_nontrivial_c_struct) &&
2817 "unexpected destructor type");
2818 pushDestroy(dtorKind: DtorKind, addr: DeclPtr, type: Ty);
2819 CalleeDestructedParamCleanups[cast<ParmVarDecl>(Val: &D)] =
2820 EHStack.stable_begin();
2821 }
2822 }
2823 } else {
2824 // Check if the parameter address is controlled by OpenMP runtime.
2825 Address OpenMPLocalAddr =
2826 getLangOpts().OpenMP
2827 ? CGM.getOpenMPRuntime().getAddressOfLocalVariable(CGF&: *this, VD: &D)
2828 : Address::invalid();
2829 if (getLangOpts().OpenMP && OpenMPLocalAddr.isValid()) {
2830 DeclPtr = OpenMPLocalAddr;
2831 AllocaPtr = DeclPtr;
2832 } else {
2833 // Otherwise, create a casted temporary to hold the value.
2834 DeclPtr = CreateMemTemp(T: Ty, Align: getContext().getDeclAlign(D: &D),
2835 Name: D.getName() + ".addr", Alloca: &AllocaPtr);
2836 }
2837 DoStore = true;
2838 }
2839
2840 llvm::Value *ArgVal = (DoStore ? Arg.getDirectValue() : nullptr);
2841
2842 LValue lv = MakeAddrLValue(Addr: DeclPtr, T: Ty);
2843 // If this is a thunk, don't bother with ARC lifetime management.
2844 // The true implementation will take care of that.
2845 if (IsScalar && !CurFuncIsThunk) {
2846 Qualifiers qs = Ty.getQualifiers();
2847 if (Qualifiers::ObjCLifetime lt = qs.getObjCLifetime()) {
2848 // We honor __attribute__((ns_consumed)) for types with lifetime.
2849 // For __strong, it's handled by just skipping the initial retain;
2850 // otherwise we have to balance out the initial +1 with an extra
2851 // cleanup to do the release at the end of the function.
2852 bool isConsumed = D.hasAttr<NSConsumedAttr>();
2853
2854 // If a parameter is pseudo-strong then we can omit the implicit retain.
2855 if (D.isARCPseudoStrong()) {
2856 assert(lt == Qualifiers::OCL_Strong &&
2857 "pseudo-strong variable isn't strong?");
2858 assert(qs.hasConst() && "pseudo-strong variable should be const!");
2859 lt = Qualifiers::OCL_ExplicitNone;
2860 }
2861
2862 // Load objects passed indirectly.
2863 if (Arg.isIndirect() && !ArgVal)
2864 ArgVal = Builder.CreateLoad(Addr: DeclPtr);
2865
2866 if (lt == Qualifiers::OCL_Strong) {
2867 if (!isConsumed) {
2868 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2869 // use objc_storeStrong(&dest, value) for retaining the
2870 // object. But first, store a null into 'dest' because
2871 // objc_storeStrong attempts to release its old value.
2872 llvm::Value *Null = CGM.EmitNullConstant(T: D.getType());
2873 EmitStoreOfScalar(value: Null, lvalue: lv, /* isInitialization */ isInit: true);
2874 EmitARCStoreStrongCall(addr: lv.getAddress(), value: ArgVal, resultIgnored: true);
2875 DoStore = false;
2876 }
2877 else
2878 // Don't use objc_retainBlock for block pointers, because we
2879 // don't want to Block_copy something just because we got it
2880 // as a parameter.
2881 ArgVal = EmitARCRetainNonBlock(value: ArgVal);
2882 }
2883 } else {
2884 // Push the cleanup for a consumed parameter.
2885 if (isConsumed) {
2886 ARCPreciseLifetime_t precise = (D.hasAttr<ObjCPreciseLifetimeAttr>()
2887 ? ARCPreciseLifetime : ARCImpreciseLifetime);
2888 EHStack.pushCleanup<ConsumeARCParameter>(Kind: getARCCleanupKind(), A: ArgVal,
2889 A: precise);
2890 }
2891
2892 if (lt == Qualifiers::OCL_Weak) {
2893 EmitARCInitWeak(addr: DeclPtr, value: ArgVal);
2894 DoStore = false; // The weak init is a store, no need to do two.
2895 }
2896 }
2897
2898 // Enter the cleanup scope.
2899 EmitAutoVarWithLifetime(CGF&: *this, var: D, addr: DeclPtr, lifetime: lt);
2900 }
2901 }
2902
2903 // Store the initial value into the alloca.
2904 if (DoStore)
2905 EmitStoreOfScalar(value: ArgVal, lvalue: lv, /* isInitialization */ isInit: true);
2906
2907 setAddrOfLocalVar(VD: &D, Addr: DeclPtr);
2908
2909 // Push a FakeUse 'cleanup' object onto the EHStack for the parameter,
2910 // which may be the 'this' pointer. This causes the emission of a fake.use
2911 // call with the parameter as argument at the end of the function.
2912 if (CGM.getCodeGenOpts().getExtendVariableLiveness() ==
2913 CodeGenOptions::ExtendVariableLivenessKind::All ||
2914 (CGM.getCodeGenOpts().getExtendVariableLiveness() ==
2915 CodeGenOptions::ExtendVariableLivenessKind::This &&
2916 &D == CXXABIThisDecl)) {
2917 // We don't emit fake uses for coroutine parameters, other than `this`.
2918 if (auto *FnDecl = dyn_cast_or_null<FunctionDecl>(Val: CurCodeDecl);
2919 &D == CXXABIThisDecl || !FnDecl || !FnDecl->getBody() ||
2920 FnDecl->getBody()->getStmtClass() != Stmt::CoroutineBodyStmtClass) {
2921 if (shouldExtendLifetime(Context: getContext(), FuncDecl: CurCodeDecl, D, CXXABIThisDecl))
2922 EHStack.pushCleanup<FakeUse>(Kind: NormalFakeUse, A: DeclPtr);
2923 }
2924 }
2925
2926 // Emit debug info for param declarations in non-thunk functions.
2927 if (CGDebugInfo *DI = getDebugInfo()) {
2928 if (CGM.getCodeGenOpts().hasReducedDebugInfo() && !CurFuncIsThunk &&
2929 !NoDebugInfo) {
2930 llvm::DILocalVariable *DILocalVar = DI->EmitDeclareOfArgVariable(
2931 Decl: &D, AI: AllocaPtr.getPointer(), ArgNo, Builder, UsePointerValue: UseIndirectDebugAddress);
2932 if (const auto *Var = dyn_cast_or_null<ParmVarDecl>(Val: &D))
2933 DI->getParamDbgMappings().insert(KV: {Var, DILocalVar});
2934 }
2935 }
2936
2937 if (D.hasAttr<AnnotateAttr>())
2938 EmitVarAnnotations(D: &D, V: DeclPtr.emitRawPointer(CGF&: *this));
2939
2940 // We can only check return value nullability if all arguments to the
2941 // function satisfy their nullability preconditions. This makes it necessary
2942 // to emit null checks for args in the function body itself.
2943 if (requiresReturnValueNullabilityCheck()) {
2944 auto Nullability = Ty->getNullability();
2945 if (Nullability && *Nullability == NullabilityKind::NonNull) {
2946 SanitizerScope SanScope(this);
2947 RetValNullabilityPrecondition =
2948 Builder.CreateAnd(LHS: RetValNullabilityPrecondition,
2949 RHS: Builder.CreateIsNotNull(Arg: Arg.getAnyValue()));
2950 }
2951 }
2952}
2953
2954void CodeGenModule::EmitOMPDeclareReduction(const OMPDeclareReductionDecl *D,
2955 CodeGenFunction *CGF) {
2956 if (!LangOpts.OpenMP || (!LangOpts.EmitAllDecls && !D->isUsed()))
2957 return;
2958 getOpenMPRuntime().emitUserDefinedReduction(CGF, D);
2959}
2960
2961void CodeGenModule::EmitOMPDeclareMapper(const OMPDeclareMapperDecl *D,
2962 CodeGenFunction *CGF) {
2963 if (!LangOpts.OpenMP || LangOpts.OpenMPSimd ||
2964 (!LangOpts.EmitAllDecls && !D->isUsed()))
2965 return;
2966 getOpenMPRuntime().emitUserDefinedMapper(D, CGF);
2967}
2968
2969void CodeGenModule::EmitOpenACCDeclare(const OpenACCDeclareDecl *D,
2970 CodeGenFunction *CGF) {
2971 // This is a no-op, we cna just ignore these declarations.
2972}
2973
2974void CodeGenModule::EmitOpenACCRoutine(const OpenACCRoutineDecl *D,
2975 CodeGenFunction *CGF) {
2976 // This is a no-op, we cna just ignore these declarations.
2977}
2978
2979void CodeGenModule::EmitOMPRequiresDecl(const OMPRequiresDecl *D) {
2980 getOpenMPRuntime().processRequiresDirective(D);
2981}
2982
2983void CodeGenModule::EmitOMPAllocateDecl(const OMPAllocateDecl *D) {
2984 for (const Expr *E : D->varlist()) {
2985 const auto *DE = cast<DeclRefExpr>(Val: E);
2986 const auto *VD = cast<VarDecl>(Val: DE->getDecl());
2987
2988 // Skip all but globals.
2989 if (!VD->hasGlobalStorage())
2990 continue;
2991
2992 // Check if the global has been materialized yet or not. If not, we are done
2993 // as any later generation will utilize the OMPAllocateDeclAttr. However, if
2994 // we already emitted the global we might have done so before the
2995 // OMPAllocateDeclAttr was attached, leading to the wrong address space
2996 // (potentially). While not pretty, common practise is to remove the old IR
2997 // global and generate a new one, so we do that here too. Uses are replaced
2998 // properly.
2999 StringRef MangledName = getMangledName(GD: VD);
3000 llvm::GlobalValue *Entry = GetGlobalValue(Ref: MangledName);
3001 if (!Entry)
3002 continue;
3003
3004 // We can also keep the existing global if the address space is what we
3005 // expect it to be, if not, it is replaced.
3006 clang::LangAS GVAS = GetGlobalVarAddressSpace(D: VD);
3007 auto TargetAS = getContext().getTargetAddressSpace(AS: GVAS);
3008 if (Entry->getType()->getAddressSpace() == TargetAS)
3009 continue;
3010
3011 llvm::PointerType *PTy = llvm::PointerType::get(C&: getLLVMContext(), AddressSpace: TargetAS);
3012
3013 // Replace all uses of the old global with a cast. Since we mutate the type
3014 // in place we neeed an intermediate that takes the spot of the old entry
3015 // until we can create the cast.
3016 llvm::GlobalVariable *DummyGV = new llvm::GlobalVariable(
3017 getModule(), Entry->getValueType(), false,
3018 llvm::GlobalValue::CommonLinkage, nullptr, "dummy", nullptr,
3019 llvm::GlobalVariable::NotThreadLocal, Entry->getAddressSpace());
3020 Entry->replaceAllUsesWith(V: DummyGV);
3021
3022 Entry->mutateType(Ty: PTy);
3023 llvm::Constant *NewPtrForOldDecl =
3024 llvm::ConstantExpr::getAddrSpaceCast(C: Entry, Ty: DummyGV->getType());
3025
3026 // Now we have a casted version of the changed global, the dummy can be
3027 // replaced and deleted.
3028 DummyGV->replaceAllUsesWith(V: NewPtrForOldDecl);
3029 DummyGV->eraseFromParent();
3030 }
3031}
3032
3033std::optional<CharUnits>
3034CodeGenModule::getOMPAllocateAlignment(const VarDecl *VD) {
3035 if (const auto *AA = VD->getAttr<OMPAllocateDeclAttr>()) {
3036 if (Expr *Alignment = AA->getAlignment()) {
3037 unsigned UserAlign =
3038 Alignment->EvaluateKnownConstInt(Ctx: getContext()).getExtValue();
3039 CharUnits NaturalAlign =
3040 getNaturalTypeAlignment(T: VD->getType().getNonReferenceType());
3041
3042 // OpenMP5.1 pg 185 lines 7-10
3043 // Each item in the align modifier list must be aligned to the maximum
3044 // of the specified alignment and the type's natural alignment.
3045 return CharUnits::fromQuantity(
3046 Quantity: std::max<unsigned>(a: UserAlign, b: NaturalAlign.getQuantity()));
3047 }
3048 }
3049 return std::nullopt;
3050}
3051