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 "ConstantEmitter.h"
22#include "EHScopeStack.h"
23#include "PatternInit.h"
24#include "TargetInfo.h"
25#include "clang/AST/ASTContext.h"
26#include "clang/AST/Attr.h"
27#include "clang/AST/CharUnits.h"
28#include "clang/AST/Decl.h"
29#include "clang/AST/DeclObjC.h"
30#include "clang/AST/DeclOpenMP.h"
31#include "clang/Basic/CodeGenOptions.h"
32#include "clang/Basic/SourceManager.h"
33#include "clang/Basic/TargetInfo.h"
34#include "clang/CodeGen/CGFunctionInfo.h"
35#include "clang/Sema/Sema.h"
36#include "llvm/Analysis/ConstantFolding.h"
37#include "llvm/Analysis/ValueTracking.h"
38#include "llvm/IR/DataLayout.h"
39#include "llvm/IR/GlobalVariable.h"
40#include "llvm/IR/Instructions.h"
41#include "llvm/IR/Intrinsics.h"
42#include "llvm/IR/Type.h"
43#include <optional>
44
45using namespace clang;
46using namespace CodeGen;
47
48static_assert(clang::Sema::MaximumAlignment <= llvm::Value::MaximumAlignment,
49 "Clang max alignment greater than what LLVM supports?");
50
51void CodeGenFunction::EmitDecl(const Decl &D) {
52 switch (D.getKind()) {
53 case Decl::BuiltinTemplate:
54 case Decl::TranslationUnit:
55 case Decl::ExternCContext:
56 case Decl::Namespace:
57 case Decl::UnresolvedUsingTypename:
58 case Decl::ClassTemplateSpecialization:
59 case Decl::ClassTemplatePartialSpecialization:
60 case Decl::VarTemplateSpecialization:
61 case Decl::VarTemplatePartialSpecialization:
62 case Decl::TemplateTypeParm:
63 case Decl::UnresolvedUsingValue:
64 case Decl::NonTypeTemplateParm:
65 case Decl::CXXDeductionGuide:
66 case Decl::CXXMethod:
67 case Decl::CXXConstructor:
68 case Decl::CXXDestructor:
69 case Decl::CXXConversion:
70 case Decl::Field:
71 case Decl::MSProperty:
72 case Decl::IndirectField:
73 case Decl::ObjCIvar:
74 case Decl::ObjCAtDefsField:
75 case Decl::ParmVar:
76 case Decl::ImplicitParam:
77 case Decl::ClassTemplate:
78 case Decl::VarTemplate:
79 case Decl::FunctionTemplate:
80 case Decl::TypeAliasTemplate:
81 case Decl::TemplateTemplateParm:
82 case Decl::ObjCMethod:
83 case Decl::ObjCCategory:
84 case Decl::ObjCProtocol:
85 case Decl::ObjCInterface:
86 case Decl::ObjCCategoryImpl:
87 case Decl::ObjCImplementation:
88 case Decl::ObjCProperty:
89 case Decl::ObjCCompatibleAlias:
90 case Decl::PragmaComment:
91 case Decl::PragmaDetectMismatch:
92 case Decl::AccessSpec:
93 case Decl::LinkageSpec:
94 case Decl::Export:
95 case Decl::ObjCPropertyImpl:
96 case Decl::FileScopeAsm:
97 case Decl::TopLevelStmt:
98 case Decl::Friend:
99 case Decl::FriendTemplate:
100 case Decl::Block:
101 case Decl::Captured:
102 case Decl::UsingShadow:
103 case Decl::ConstructorUsingShadow:
104 case Decl::ObjCTypeParam:
105 case Decl::Binding:
106 case Decl::UnresolvedUsingIfExists:
107 case Decl::HLSLBuffer:
108 llvm_unreachable("Declaration should not be in declstmts!");
109 case Decl::Record: // struct/union/class X;
110 case Decl::CXXRecord: // struct/union/class X; [C++]
111 if (CGDebugInfo *DI = getDebugInfo())
112 if (cast<RecordDecl>(Val: D).getDefinition())
113 DI->EmitAndRetainType(Ty: getContext().getRecordType(Decl: cast<RecordDecl>(Val: &D)));
114 return;
115 case Decl::Enum: // enum X;
116 if (CGDebugInfo *DI = getDebugInfo())
117 if (cast<EnumDecl>(Val: D).getDefinition())
118 DI->EmitAndRetainType(Ty: getContext().getEnumType(Decl: cast<EnumDecl>(Val: &D)));
119 return;
120 case Decl::Function: // void X();
121 case Decl::EnumConstant: // enum ? { X = ? }
122 case Decl::StaticAssert: // static_assert(X, ""); [C++0x]
123 case Decl::Label: // __label__ x;
124 case Decl::Import:
125 case Decl::MSGuid: // __declspec(uuid("..."))
126 case Decl::UnnamedGlobalConstant:
127 case Decl::TemplateParamObject:
128 case Decl::OMPThreadPrivate:
129 case Decl::OMPAllocate:
130 case Decl::OMPCapturedExpr:
131 case Decl::OMPRequires:
132 case Decl::Empty:
133 case Decl::Concept:
134 case Decl::ImplicitConceptSpecialization:
135 case Decl::LifetimeExtendedTemporary:
136 case Decl::RequiresExprBody:
137 // None of these decls require codegen support.
138 return;
139
140 case Decl::NamespaceAlias:
141 if (CGDebugInfo *DI = getDebugInfo())
142 DI->EmitNamespaceAlias(NA: cast<NamespaceAliasDecl>(Val: D));
143 return;
144 case Decl::Using: // using X; [C++]
145 if (CGDebugInfo *DI = getDebugInfo())
146 DI->EmitUsingDecl(UD: cast<UsingDecl>(Val: D));
147 return;
148 case Decl::UsingEnum: // using enum X; [C++]
149 if (CGDebugInfo *DI = getDebugInfo())
150 DI->EmitUsingEnumDecl(UD: cast<UsingEnumDecl>(Val: D));
151 return;
152 case Decl::UsingPack:
153 for (auto *Using : cast<UsingPackDecl>(Val: D).expansions())
154 EmitDecl(D: *Using);
155 return;
156 case Decl::UsingDirective: // using namespace X; [C++]
157 if (CGDebugInfo *DI = getDebugInfo())
158 DI->EmitUsingDirective(UD: cast<UsingDirectiveDecl>(Val: D));
159 return;
160 case Decl::Var:
161 case Decl::Decomposition: {
162 const VarDecl &VD = cast<VarDecl>(Val: D);
163 assert(VD.isLocalVarDecl() &&
164 "Should not see file-scope variables inside a function!");
165 EmitVarDecl(D: VD);
166 if (auto *DD = dyn_cast<DecompositionDecl>(Val: &VD))
167 for (auto *B : DD->bindings())
168 if (auto *HD = B->getHoldingVar())
169 EmitVarDecl(D: *HD);
170 return;
171 }
172
173 case Decl::OMPDeclareReduction:
174 return CGM.EmitOMPDeclareReduction(D: cast<OMPDeclareReductionDecl>(Val: &D), CGF: this);
175
176 case Decl::OMPDeclareMapper:
177 return CGM.EmitOMPDeclareMapper(D: cast<OMPDeclareMapperDecl>(Val: &D), CGF: this);
178
179 case Decl::Typedef: // typedef int X;
180 case Decl::TypeAlias: { // using X = int; [C++0x]
181 QualType Ty = cast<TypedefNameDecl>(Val: D).getUnderlyingType();
182 if (CGDebugInfo *DI = getDebugInfo())
183 DI->EmitAndRetainType(Ty);
184 if (Ty->isVariablyModifiedType())
185 EmitVariablyModifiedType(Ty);
186 return;
187 }
188 }
189}
190
191/// EmitVarDecl - This method handles emission of any variable declaration
192/// inside a function, including static vars etc.
193void CodeGenFunction::EmitVarDecl(const VarDecl &D) {
194 if (D.hasExternalStorage())
195 // Don't emit it now, allow it to be emitted lazily on its first use.
196 return;
197
198 // Some function-scope variable does not have static storage but still
199 // needs to be emitted like a static variable, e.g. a function-scope
200 // variable in constant address space in OpenCL.
201 if (D.getStorageDuration() != SD_Automatic) {
202 // Static sampler variables translated to function calls.
203 if (D.getType()->isSamplerT())
204 return;
205
206 llvm::GlobalValue::LinkageTypes Linkage =
207 CGM.getLLVMLinkageVarDefinition(VD: &D);
208
209 // FIXME: We need to force the emission/use of a guard variable for
210 // some variables even if we can constant-evaluate them because
211 // we can't guarantee every translation unit will constant-evaluate them.
212
213 return EmitStaticVarDecl(D, Linkage);
214 }
215
216 if (D.getType().getAddressSpace() == LangAS::opencl_local)
217 return CGM.getOpenCLRuntime().EmitWorkGroupLocalVarDecl(CGF&: *this, D);
218
219 assert(D.hasLocalStorage());
220 return EmitAutoVarDecl(D);
221}
222
223static std::string getStaticDeclName(CodeGenModule &CGM, const VarDecl &D) {
224 if (CGM.getLangOpts().CPlusPlus)
225 return CGM.getMangledName(GD: &D).str();
226
227 // If this isn't C++, we don't need a mangled name, just a pretty one.
228 assert(!D.isExternallyVisible() && "name shouldn't matter");
229 std::string ContextName;
230 const DeclContext *DC = D.getDeclContext();
231 if (auto *CD = dyn_cast<CapturedDecl>(Val: DC))
232 DC = cast<DeclContext>(Val: CD->getNonClosureContext());
233 if (const auto *FD = dyn_cast<FunctionDecl>(Val: DC))
234 ContextName = std::string(CGM.getMangledName(GD: FD));
235 else if (const auto *BD = dyn_cast<BlockDecl>(Val: DC))
236 ContextName = std::string(CGM.getBlockMangledName(GD: GlobalDecl(), BD));
237 else if (const auto *OMD = dyn_cast<ObjCMethodDecl>(Val: DC))
238 ContextName = OMD->getSelector().getAsString();
239 else
240 llvm_unreachable("Unknown context for static var decl");
241
242 ContextName += "." + D.getNameAsString();
243 return ContextName;
244}
245
246llvm::Constant *CodeGenModule::getOrCreateStaticVarDecl(
247 const VarDecl &D, llvm::GlobalValue::LinkageTypes Linkage) {
248 // In general, we don't always emit static var decls once before we reference
249 // them. It is possible to reference them before emitting the function that
250 // contains them, and it is possible to emit the containing function multiple
251 // times.
252 if (llvm::Constant *ExistingGV = StaticLocalDeclMap[&D])
253 return ExistingGV;
254
255 QualType Ty = D.getType();
256 assert(Ty->isConstantSizeType() && "VLAs can't be static");
257
258 // Use the label if the variable is renamed with the asm-label extension.
259 std::string Name;
260 if (D.hasAttr<AsmLabelAttr>())
261 Name = std::string(getMangledName(GD: &D));
262 else
263 Name = getStaticDeclName(CGM&: *this, D);
264
265 llvm::Type *LTy = getTypes().ConvertTypeForMem(T: Ty);
266 LangAS AS = GetGlobalVarAddressSpace(D: &D);
267 unsigned TargetAS = getContext().getTargetAddressSpace(AS);
268
269 // OpenCL variables in local address space and CUDA shared
270 // variables cannot have an initializer.
271 llvm::Constant *Init = nullptr;
272 if (Ty.getAddressSpace() == LangAS::opencl_local ||
273 D.hasAttr<CUDASharedAttr>() || D.hasAttr<LoaderUninitializedAttr>())
274 Init = llvm::UndefValue::get(T: LTy);
275 else
276 Init = EmitNullConstant(T: Ty);
277
278 llvm::GlobalVariable *GV = new llvm::GlobalVariable(
279 getModule(), LTy, Ty.isConstant(Ctx: getContext()), Linkage, Init, Name,
280 nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS);
281 GV->setAlignment(getContext().getDeclAlign(D: &D).getAsAlign());
282
283 if (supportsCOMDAT() && GV->isWeakForLinker())
284 GV->setComdat(TheModule.getOrInsertComdat(Name: GV->getName()));
285
286 if (D.getTLSKind())
287 setTLSMode(GV, D);
288
289 setGVProperties(GV, D: &D);
290 getTargetCodeGenInfo().setTargetAttributes(D: cast<Decl>(Val: &D), GV, M&: *this);
291
292 // Make sure the result is of the correct type.
293 LangAS ExpectedAS = Ty.getAddressSpace();
294 llvm::Constant *Addr = GV;
295 if (AS != ExpectedAS) {
296 Addr = getTargetCodeGenInfo().performAddrSpaceCast(
297 CGM&: *this, V: GV, SrcAddr: AS, DestAddr: ExpectedAS,
298 DestTy: llvm::PointerType::get(C&: getLLVMContext(),
299 AddressSpace: getContext().getTargetAddressSpace(AS: ExpectedAS)));
300 }
301
302 setStaticLocalDeclAddress(D: &D, C: Addr);
303
304 // Ensure that the static local gets initialized by making sure the parent
305 // function gets emitted eventually.
306 const Decl *DC = cast<Decl>(Val: D.getDeclContext());
307
308 // We can't name blocks or captured statements directly, so try to emit their
309 // parents.
310 if (isa<BlockDecl>(Val: DC) || isa<CapturedDecl>(Val: DC)) {
311 DC = DC->getNonClosureContext();
312 // FIXME: Ensure that global blocks get emitted.
313 if (!DC)
314 return Addr;
315 }
316
317 GlobalDecl GD;
318 if (const auto *CD = dyn_cast<CXXConstructorDecl>(Val: DC))
319 GD = GlobalDecl(CD, Ctor_Base);
320 else if (const auto *DD = dyn_cast<CXXDestructorDecl>(Val: DC))
321 GD = GlobalDecl(DD, Dtor_Base);
322 else if (const auto *FD = dyn_cast<FunctionDecl>(Val: DC))
323 GD = GlobalDecl(FD);
324 else {
325 // Don't do anything for Obj-C method decls or global closures. We should
326 // never defer them.
327 assert(isa<ObjCMethodDecl>(DC) && "unexpected parent code decl");
328 }
329 if (GD.getDecl()) {
330 // Disable emission of the parent function for the OpenMP device codegen.
331 CGOpenMPRuntime::DisableAutoDeclareTargetRAII NoDeclTarget(*this);
332 (void)GetAddrOfGlobal(GD);
333 }
334
335 return Addr;
336}
337
338/// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
339/// global variable that has already been created for it. If the initializer
340/// has a different type than GV does, this may free GV and return a different
341/// one. Otherwise it just returns GV.
342llvm::GlobalVariable *
343CodeGenFunction::AddInitializerToStaticVarDecl(const VarDecl &D,
344 llvm::GlobalVariable *GV) {
345 ConstantEmitter emitter(*this);
346 llvm::Constant *Init = emitter.tryEmitForInitializer(D);
347
348 // If constant emission failed, then this should be a C++ static
349 // initializer.
350 if (!Init) {
351 if (!getLangOpts().CPlusPlus)
352 CGM.ErrorUnsupported(S: D.getInit(), Type: "constant l-value expression");
353 else if (D.hasFlexibleArrayInit(Ctx: getContext()))
354 CGM.ErrorUnsupported(S: D.getInit(), Type: "flexible array initializer");
355 else if (HaveInsertPoint()) {
356 // Since we have a static initializer, this global variable can't
357 // be constant.
358 GV->setConstant(false);
359
360 EmitCXXGuardedInit(D, DeclPtr: GV, /*PerformInit*/true);
361 }
362 return GV;
363 }
364
365#ifndef NDEBUG
366 CharUnits VarSize = CGM.getContext().getTypeSizeInChars(D.getType()) +
367 D.getFlexibleArrayInitChars(getContext());
368 CharUnits CstSize = CharUnits::fromQuantity(
369 CGM.getDataLayout().getTypeAllocSize(Init->getType()));
370 assert(VarSize == CstSize && "Emitted constant has unexpected size");
371#endif
372
373 // The initializer may differ in type from the global. Rewrite
374 // the global to match the initializer. (We have to do this
375 // because some types, like unions, can't be completely represented
376 // in the LLVM type system.)
377 if (GV->getValueType() != Init->getType()) {
378 llvm::GlobalVariable *OldGV = GV;
379
380 GV = new llvm::GlobalVariable(
381 CGM.getModule(), Init->getType(), OldGV->isConstant(),
382 OldGV->getLinkage(), Init, "",
383 /*InsertBefore*/ OldGV, OldGV->getThreadLocalMode(),
384 OldGV->getType()->getPointerAddressSpace());
385 GV->setVisibility(OldGV->getVisibility());
386 GV->setDSOLocal(OldGV->isDSOLocal());
387 GV->setComdat(OldGV->getComdat());
388
389 // Steal the name of the old global
390 GV->takeName(V: OldGV);
391
392 // Replace all uses of the old global with the new global
393 OldGV->replaceAllUsesWith(V: GV);
394
395 // Erase the old global, since it is no longer used.
396 OldGV->eraseFromParent();
397 }
398
399 bool NeedsDtor =
400 D.needsDestruction(Ctx: getContext()) == QualType::DK_cxx_destructor;
401
402 GV->setConstant(
403 D.getType().isConstantStorage(Ctx: getContext(), ExcludeCtor: true, ExcludeDtor: !NeedsDtor));
404 GV->setInitializer(Init);
405
406 emitter.finalize(global: GV);
407
408 if (NeedsDtor && HaveInsertPoint()) {
409 // We have a constant initializer, but a nontrivial destructor. We still
410 // need to perform a guarded "initialization" in order to register the
411 // destructor.
412 EmitCXXGuardedInit(D, DeclPtr: GV, /*PerformInit*/false);
413 }
414
415 return GV;
416}
417
418void CodeGenFunction::EmitStaticVarDecl(const VarDecl &D,
419 llvm::GlobalValue::LinkageTypes Linkage) {
420 // Check to see if we already have a global variable for this
421 // declaration. This can happen when double-emitting function
422 // bodies, e.g. with complete and base constructors.
423 llvm::Constant *addr = CGM.getOrCreateStaticVarDecl(D, Linkage);
424 CharUnits alignment = getContext().getDeclAlign(D: &D);
425
426 // Store into LocalDeclMap before generating initializer to handle
427 // circular references.
428 llvm::Type *elemTy = ConvertTypeForMem(T: D.getType());
429 setAddrOfLocalVar(VD: &D, Addr: Address(addr, elemTy, alignment));
430
431 // We can't have a VLA here, but we can have a pointer to a VLA,
432 // even though that doesn't really make any sense.
433 // Make sure to evaluate VLA bounds now so that we have them for later.
434 if (D.getType()->isVariablyModifiedType())
435 EmitVariablyModifiedType(Ty: D.getType());
436
437 // Save the type in case adding the initializer forces a type change.
438 llvm::Type *expectedType = addr->getType();
439
440 llvm::GlobalVariable *var =
441 cast<llvm::GlobalVariable>(Val: addr->stripPointerCasts());
442
443 // CUDA's local and local static __shared__ variables should not
444 // have any non-empty initializers. This is ensured by Sema.
445 // Whatever initializer such variable may have when it gets here is
446 // a no-op and should not be emitted.
447 bool isCudaSharedVar = getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
448 D.hasAttr<CUDASharedAttr>();
449 // If this value has an initializer, emit it.
450 if (D.getInit() && !isCudaSharedVar)
451 var = AddInitializerToStaticVarDecl(D, GV: var);
452
453 var->setAlignment(alignment.getAsAlign());
454
455 if (D.hasAttr<AnnotateAttr>())
456 CGM.AddGlobalAnnotations(D: &D, GV: var);
457
458 if (auto *SA = D.getAttr<PragmaClangBSSSectionAttr>())
459 var->addAttribute(Kind: "bss-section", Val: SA->getName());
460 if (auto *SA = D.getAttr<PragmaClangDataSectionAttr>())
461 var->addAttribute(Kind: "data-section", Val: SA->getName());
462 if (auto *SA = D.getAttr<PragmaClangRodataSectionAttr>())
463 var->addAttribute(Kind: "rodata-section", Val: SA->getName());
464 if (auto *SA = D.getAttr<PragmaClangRelroSectionAttr>())
465 var->addAttribute(Kind: "relro-section", Val: SA->getName());
466
467 if (const SectionAttr *SA = D.getAttr<SectionAttr>())
468 var->setSection(SA->getName());
469
470 if (D.hasAttr<RetainAttr>())
471 CGM.addUsedGlobal(GV: var);
472 else if (D.hasAttr<UsedAttr>())
473 CGM.addUsedOrCompilerUsedGlobal(GV: var);
474
475 if (CGM.getCodeGenOpts().KeepPersistentStorageVariables)
476 CGM.addUsedOrCompilerUsedGlobal(GV: var);
477
478 // We may have to cast the constant because of the initializer
479 // mismatch above.
480 //
481 // FIXME: It is really dangerous to store this in the map; if anyone
482 // RAUW's the GV uses of this constant will be invalid.
483 llvm::Constant *castedAddr =
484 llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(C: var, Ty: expectedType);
485 LocalDeclMap.find(Val: &D)->second = Address(castedAddr, elemTy, alignment);
486 CGM.setStaticLocalDeclAddress(D: &D, C: castedAddr);
487
488 CGM.getSanitizerMetadata()->reportGlobal(GV: var, D);
489
490 // Emit global variable debug descriptor for static vars.
491 CGDebugInfo *DI = getDebugInfo();
492 if (DI && CGM.getCodeGenOpts().hasReducedDebugInfo()) {
493 DI->setLocation(D.getLocation());
494 DI->EmitGlobalVariable(GV: var, Decl: &D);
495 }
496}
497
498namespace {
499 struct DestroyObject final : EHScopeStack::Cleanup {
500 DestroyObject(Address addr, QualType type,
501 CodeGenFunction::Destroyer *destroyer,
502 bool useEHCleanupForArray)
503 : addr(addr), type(type), destroyer(destroyer),
504 useEHCleanupForArray(useEHCleanupForArray) {}
505
506 Address addr;
507 QualType type;
508 CodeGenFunction::Destroyer *destroyer;
509 bool useEHCleanupForArray;
510
511 void Emit(CodeGenFunction &CGF, Flags flags) override {
512 // Don't use an EH cleanup recursively from an EH cleanup.
513 bool useEHCleanupForArray =
514 flags.isForNormalCleanup() && this->useEHCleanupForArray;
515
516 CGF.emitDestroy(addr, type, destroyer, useEHCleanupForArray);
517 }
518 };
519
520 template <class Derived>
521 struct DestroyNRVOVariable : EHScopeStack::Cleanup {
522 DestroyNRVOVariable(Address addr, QualType type, llvm::Value *NRVOFlag)
523 : NRVOFlag(NRVOFlag), Loc(addr), Ty(type) {}
524
525 llvm::Value *NRVOFlag;
526 Address Loc;
527 QualType Ty;
528
529 void Emit(CodeGenFunction &CGF, Flags flags) override {
530 // Along the exceptions path we always execute the dtor.
531 bool NRVO = flags.isForNormalCleanup() && NRVOFlag;
532
533 llvm::BasicBlock *SkipDtorBB = nullptr;
534 if (NRVO) {
535 // If we exited via NRVO, we skip the destructor call.
536 llvm::BasicBlock *RunDtorBB = CGF.createBasicBlock(name: "nrvo.unused");
537 SkipDtorBB = CGF.createBasicBlock(name: "nrvo.skipdtor");
538 llvm::Value *DidNRVO =
539 CGF.Builder.CreateFlagLoad(Addr: NRVOFlag, Name: "nrvo.val");
540 CGF.Builder.CreateCondBr(Cond: DidNRVO, True: SkipDtorBB, False: RunDtorBB);
541 CGF.EmitBlock(BB: RunDtorBB);
542 }
543
544 static_cast<Derived *>(this)->emitDestructorCall(CGF);
545
546 if (NRVO) CGF.EmitBlock(BB: SkipDtorBB);
547 }
548
549 virtual ~DestroyNRVOVariable() = default;
550 };
551
552 struct DestroyNRVOVariableCXX final
553 : DestroyNRVOVariable<DestroyNRVOVariableCXX> {
554 DestroyNRVOVariableCXX(Address addr, QualType type,
555 const CXXDestructorDecl *Dtor, llvm::Value *NRVOFlag)
556 : DestroyNRVOVariable<DestroyNRVOVariableCXX>(addr, type, NRVOFlag),
557 Dtor(Dtor) {}
558
559 const CXXDestructorDecl *Dtor;
560
561 void emitDestructorCall(CodeGenFunction &CGF) {
562 CGF.EmitCXXDestructorCall(D: Dtor, Type: Dtor_Complete,
563 /*ForVirtualBase=*/false,
564 /*Delegating=*/false, This: Loc, ThisTy: Ty);
565 }
566 };
567
568 struct DestroyNRVOVariableC final
569 : DestroyNRVOVariable<DestroyNRVOVariableC> {
570 DestroyNRVOVariableC(Address addr, llvm::Value *NRVOFlag, QualType Ty)
571 : DestroyNRVOVariable<DestroyNRVOVariableC>(addr, Ty, NRVOFlag) {}
572
573 void emitDestructorCall(CodeGenFunction &CGF) {
574 CGF.destroyNonTrivialCStruct(CGF, Loc, Ty);
575 }
576 };
577
578 struct CallStackRestore final : EHScopeStack::Cleanup {
579 Address Stack;
580 CallStackRestore(Address Stack) : Stack(Stack) {}
581 bool isRedundantBeforeReturn() override { return true; }
582 void Emit(CodeGenFunction &CGF, Flags flags) override {
583 llvm::Value *V = CGF.Builder.CreateLoad(Addr: Stack);
584 CGF.Builder.CreateStackRestore(Ptr: V);
585 }
586 };
587
588 struct KmpcAllocFree final : EHScopeStack::Cleanup {
589 std::pair<llvm::Value *, llvm::Value *> AddrSizePair;
590 KmpcAllocFree(const std::pair<llvm::Value *, llvm::Value *> &AddrSizePair)
591 : AddrSizePair(AddrSizePair) {}
592 void Emit(CodeGenFunction &CGF, Flags EmissionFlags) override {
593 auto &RT = CGF.CGM.getOpenMPRuntime();
594 RT.getKmpcFreeShared(CGF, AddrSizePair);
595 }
596 };
597
598 struct ExtendGCLifetime final : EHScopeStack::Cleanup {
599 const VarDecl &Var;
600 ExtendGCLifetime(const VarDecl *var) : Var(*var) {}
601
602 void Emit(CodeGenFunction &CGF, Flags flags) override {
603 // Compute the address of the local variable, in case it's a
604 // byref or something.
605 DeclRefExpr DRE(CGF.getContext(), const_cast<VarDecl *>(&Var), false,
606 Var.getType(), VK_LValue, SourceLocation());
607 llvm::Value *value = CGF.EmitLoadOfScalar(lvalue: CGF.EmitDeclRefLValue(E: &DRE),
608 Loc: SourceLocation());
609 CGF.EmitExtendGCLifetime(object: value);
610 }
611 };
612
613 struct CallCleanupFunction final : EHScopeStack::Cleanup {
614 llvm::Constant *CleanupFn;
615 const CGFunctionInfo &FnInfo;
616 const VarDecl &Var;
617
618 CallCleanupFunction(llvm::Constant *CleanupFn, const CGFunctionInfo *Info,
619 const VarDecl *Var)
620 : CleanupFn(CleanupFn), FnInfo(*Info), Var(*Var) {}
621
622 void Emit(CodeGenFunction &CGF, Flags flags) override {
623 DeclRefExpr DRE(CGF.getContext(), const_cast<VarDecl *>(&Var), false,
624 Var.getType(), VK_LValue, SourceLocation());
625 // Compute the address of the local variable, in case it's a byref
626 // or something.
627 llvm::Value *Addr = CGF.EmitDeclRefLValue(E: &DRE).getPointer(CGF);
628
629 // In some cases, the type of the function argument will be different from
630 // the type of the pointer. An example of this is
631 // void f(void* arg);
632 // __attribute__((cleanup(f))) void *g;
633 //
634 // To fix this we insert a bitcast here.
635 QualType ArgTy = FnInfo.arg_begin()->type;
636 llvm::Value *Arg =
637 CGF.Builder.CreateBitCast(V: Addr, DestTy: CGF.ConvertType(T: ArgTy));
638
639 CallArgList Args;
640 Args.add(rvalue: RValue::get(V: Arg),
641 type: CGF.getContext().getPointerType(T: Var.getType()));
642 auto Callee = CGCallee::forDirect(functionPtr: CleanupFn);
643 CGF.EmitCall(CallInfo: FnInfo, Callee, ReturnValue: ReturnValueSlot(), Args);
644 }
645 };
646} // end anonymous namespace
647
648/// EmitAutoVarWithLifetime - Does the setup required for an automatic
649/// variable with lifetime.
650static void EmitAutoVarWithLifetime(CodeGenFunction &CGF, const VarDecl &var,
651 Address addr,
652 Qualifiers::ObjCLifetime lifetime) {
653 switch (lifetime) {
654 case Qualifiers::OCL_None:
655 llvm_unreachable("present but none");
656
657 case Qualifiers::OCL_ExplicitNone:
658 // nothing to do
659 break;
660
661 case Qualifiers::OCL_Strong: {
662 CodeGenFunction::Destroyer *destroyer =
663 (var.hasAttr<ObjCPreciseLifetimeAttr>()
664 ? CodeGenFunction::destroyARCStrongPrecise
665 : CodeGenFunction::destroyARCStrongImprecise);
666
667 CleanupKind cleanupKind = CGF.getARCCleanupKind();
668 CGF.pushDestroy(kind: cleanupKind, addr, type: var.getType(), destroyer,
669 useEHCleanupForArray: cleanupKind & EHCleanup);
670 break;
671 }
672 case Qualifiers::OCL_Autoreleasing:
673 // nothing to do
674 break;
675
676 case Qualifiers::OCL_Weak:
677 // __weak objects always get EH cleanups; otherwise, exceptions
678 // could cause really nasty crashes instead of mere leaks.
679 CGF.pushDestroy(kind: NormalAndEHCleanup, addr, type: var.getType(),
680 destroyer: CodeGenFunction::destroyARCWeak,
681 /*useEHCleanup*/ useEHCleanupForArray: true);
682 break;
683 }
684}
685
686static bool isAccessedBy(const VarDecl &var, const Stmt *s) {
687 if (const Expr *e = dyn_cast<Expr>(Val: s)) {
688 // Skip the most common kinds of expressions that make
689 // hierarchy-walking expensive.
690 s = e = e->IgnoreParenCasts();
691
692 if (const DeclRefExpr *ref = dyn_cast<DeclRefExpr>(Val: e))
693 return (ref->getDecl() == &var);
694 if (const BlockExpr *be = dyn_cast<BlockExpr>(Val: e)) {
695 const BlockDecl *block = be->getBlockDecl();
696 for (const auto &I : block->captures()) {
697 if (I.getVariable() == &var)
698 return true;
699 }
700 }
701 }
702
703 for (const Stmt *SubStmt : s->children())
704 // SubStmt might be null; as in missing decl or conditional of an if-stmt.
705 if (SubStmt && isAccessedBy(var, s: SubStmt))
706 return true;
707
708 return false;
709}
710
711static bool isAccessedBy(const ValueDecl *decl, const Expr *e) {
712 if (!decl) return false;
713 if (!isa<VarDecl>(Val: decl)) return false;
714 const VarDecl *var = cast<VarDecl>(Val: decl);
715 return isAccessedBy(var: *var, s: e);
716}
717
718static bool tryEmitARCCopyWeakInit(CodeGenFunction &CGF,
719 const LValue &destLV, const Expr *init) {
720 bool needsCast = false;
721
722 while (auto castExpr = dyn_cast<CastExpr>(Val: init->IgnoreParens())) {
723 switch (castExpr->getCastKind()) {
724 // Look through casts that don't require representation changes.
725 case CK_NoOp:
726 case CK_BitCast:
727 case CK_BlockPointerToObjCPointerCast:
728 needsCast = true;
729 break;
730
731 // If we find an l-value to r-value cast from a __weak variable,
732 // emit this operation as a copy or move.
733 case CK_LValueToRValue: {
734 const Expr *srcExpr = castExpr->getSubExpr();
735 if (srcExpr->getType().getObjCLifetime() != Qualifiers::OCL_Weak)
736 return false;
737
738 // Emit the source l-value.
739 LValue srcLV = CGF.EmitLValue(E: srcExpr);
740
741 // Handle a formal type change to avoid asserting.
742 auto srcAddr = srcLV.getAddress();
743 if (needsCast) {
744 srcAddr = srcAddr.withElementType(ElemTy: destLV.getAddress().getElementType());
745 }
746
747 // If it was an l-value, use objc_copyWeak.
748 if (srcExpr->isLValue()) {
749 CGF.EmitARCCopyWeak(dst: destLV.getAddress(), src: srcAddr);
750 } else {
751 assert(srcExpr->isXValue());
752 CGF.EmitARCMoveWeak(dst: destLV.getAddress(), src: srcAddr);
753 }
754 return true;
755 }
756
757 // Stop at anything else.
758 default:
759 return false;
760 }
761
762 init = castExpr->getSubExpr();
763 }
764 return false;
765}
766
767static void drillIntoBlockVariable(CodeGenFunction &CGF,
768 LValue &lvalue,
769 const VarDecl *var) {
770 lvalue.setAddress(CGF.emitBlockByrefAddress(baseAddr: lvalue.getAddress(), V: var));
771}
772
773void CodeGenFunction::EmitNullabilityCheck(LValue LHS, llvm::Value *RHS,
774 SourceLocation Loc) {
775 if (!SanOpts.has(K: SanitizerKind::NullabilityAssign))
776 return;
777
778 auto Nullability = LHS.getType()->getNullability();
779 if (!Nullability || *Nullability != NullabilityKind::NonNull)
780 return;
781
782 // Check if the right hand side of the assignment is nonnull, if the left
783 // hand side must be nonnull.
784 SanitizerScope SanScope(this);
785 llvm::Value *IsNotNull = Builder.CreateIsNotNull(Arg: RHS);
786 llvm::Constant *StaticData[] = {
787 EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(T: LHS.getType()),
788 llvm::ConstantInt::get(Ty: Int8Ty, V: 0), // The LogAlignment info is unused.
789 llvm::ConstantInt::get(Ty: Int8Ty, V: TCK_NonnullAssign)};
790 EmitCheck(Checked: {{IsNotNull, SanitizerKind::NullabilityAssign}},
791 Check: SanitizerHandler::TypeMismatch, StaticArgs: StaticData, DynamicArgs: RHS);
792}
793
794void CodeGenFunction::EmitScalarInit(const Expr *init, const ValueDecl *D,
795 LValue lvalue, bool capturedByInit) {
796 Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
797 if (!lifetime) {
798 llvm::Value *value = EmitScalarExpr(E: init);
799 if (capturedByInit)
800 drillIntoBlockVariable(CGF&: *this, lvalue, var: cast<VarDecl>(Val: D));
801 EmitNullabilityCheck(LHS: lvalue, RHS: value, Loc: init->getExprLoc());
802 EmitStoreThroughLValue(Src: RValue::get(V: value), Dst: lvalue, isInit: true);
803 return;
804 }
805
806 if (const CXXDefaultInitExpr *DIE = dyn_cast<CXXDefaultInitExpr>(Val: init))
807 init = DIE->getExpr();
808
809 // If we're emitting a value with lifetime, we have to do the
810 // initialization *before* we leave the cleanup scopes.
811 if (auto *EWC = dyn_cast<ExprWithCleanups>(Val: init)) {
812 CodeGenFunction::RunCleanupsScope Scope(*this);
813 return EmitScalarInit(init: EWC->getSubExpr(), D, lvalue, capturedByInit);
814 }
815
816 // We have to maintain the illusion that the variable is
817 // zero-initialized. If the variable might be accessed in its
818 // initializer, zero-initialize before running the initializer, then
819 // actually perform the initialization with an assign.
820 bool accessedByInit = false;
821 if (lifetime != Qualifiers::OCL_ExplicitNone)
822 accessedByInit = (capturedByInit || isAccessedBy(decl: D, e: init));
823 if (accessedByInit) {
824 LValue tempLV = lvalue;
825 // Drill down to the __block object if necessary.
826 if (capturedByInit) {
827 // We can use a simple GEP for this because it can't have been
828 // moved yet.
829 tempLV.setAddress(emitBlockByrefAddress(baseAddr: tempLV.getAddress(),
830 V: cast<VarDecl>(Val: D),
831 /*follow*/ followForward: false));
832 }
833
834 auto ty = cast<llvm::PointerType>(Val: tempLV.getAddress().getElementType());
835 llvm::Value *zero = CGM.getNullPointer(T: ty, QT: tempLV.getType());
836
837 // If __weak, we want to use a barrier under certain conditions.
838 if (lifetime == Qualifiers::OCL_Weak)
839 EmitARCInitWeak(addr: tempLV.getAddress(), value: zero);
840
841 // Otherwise just do a simple store.
842 else
843 EmitStoreOfScalar(value: zero, lvalue: tempLV, /* isInitialization */ isInit: true);
844 }
845
846 // Emit the initializer.
847 llvm::Value *value = nullptr;
848
849 switch (lifetime) {
850 case Qualifiers::OCL_None:
851 llvm_unreachable("present but none");
852
853 case Qualifiers::OCL_Strong: {
854 if (!D || !isa<VarDecl>(Val: D) || !cast<VarDecl>(Val: D)->isARCPseudoStrong()) {
855 value = EmitARCRetainScalarExpr(expr: init);
856 break;
857 }
858 // If D is pseudo-strong, treat it like __unsafe_unretained here. This means
859 // that we omit the retain, and causes non-autoreleased return values to be
860 // immediately released.
861 [[fallthrough]];
862 }
863
864 case Qualifiers::OCL_ExplicitNone:
865 value = EmitARCUnsafeUnretainedScalarExpr(expr: init);
866 break;
867
868 case Qualifiers::OCL_Weak: {
869 // If it's not accessed by the initializer, try to emit the
870 // initialization with a copy or move.
871 if (!accessedByInit && tryEmitARCCopyWeakInit(CGF&: *this, destLV: lvalue, init)) {
872 return;
873 }
874
875 // No way to optimize a producing initializer into this. It's not
876 // worth optimizing for, because the value will immediately
877 // disappear in the common case.
878 value = EmitScalarExpr(E: init);
879
880 if (capturedByInit) drillIntoBlockVariable(CGF&: *this, lvalue, var: cast<VarDecl>(Val: D));
881 if (accessedByInit)
882 EmitARCStoreWeak(addr: lvalue.getAddress(), value, /*ignored*/ true);
883 else
884 EmitARCInitWeak(addr: lvalue.getAddress(), value);
885 return;
886 }
887
888 case Qualifiers::OCL_Autoreleasing:
889 value = EmitARCRetainAutoreleaseScalarExpr(expr: init);
890 break;
891 }
892
893 if (capturedByInit) drillIntoBlockVariable(CGF&: *this, lvalue, var: cast<VarDecl>(Val: D));
894
895 EmitNullabilityCheck(LHS: lvalue, RHS: value, Loc: init->getExprLoc());
896
897 // If the variable might have been accessed by its initializer, we
898 // might have to initialize with a barrier. We have to do this for
899 // both __weak and __strong, but __weak got filtered out above.
900 if (accessedByInit && lifetime == Qualifiers::OCL_Strong) {
901 llvm::Value *oldValue = EmitLoadOfScalar(lvalue, Loc: init->getExprLoc());
902 EmitStoreOfScalar(value, lvalue, /* isInitialization */ isInit: true);
903 EmitARCRelease(value: oldValue, precise: ARCImpreciseLifetime);
904 return;
905 }
906
907 EmitStoreOfScalar(value, lvalue, /* isInitialization */ isInit: true);
908}
909
910/// Decide whether we can emit the non-zero parts of the specified initializer
911/// with equal or fewer than NumStores scalar stores.
912static bool canEmitInitWithFewStoresAfterBZero(llvm::Constant *Init,
913 unsigned &NumStores) {
914 // Zero and Undef never requires any extra stores.
915 if (isa<llvm::ConstantAggregateZero>(Val: Init) ||
916 isa<llvm::ConstantPointerNull>(Val: Init) ||
917 isa<llvm::UndefValue>(Val: Init))
918 return true;
919 if (isa<llvm::ConstantInt>(Val: Init) || isa<llvm::ConstantFP>(Val: Init) ||
920 isa<llvm::ConstantVector>(Val: Init) || isa<llvm::BlockAddress>(Val: Init) ||
921 isa<llvm::ConstantExpr>(Val: Init))
922 return Init->isNullValue() || NumStores--;
923
924 // See if we can emit each element.
925 if (isa<llvm::ConstantArray>(Val: Init) || isa<llvm::ConstantStruct>(Val: Init)) {
926 for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
927 llvm::Constant *Elt = cast<llvm::Constant>(Val: Init->getOperand(i));
928 if (!canEmitInitWithFewStoresAfterBZero(Init: Elt, NumStores))
929 return false;
930 }
931 return true;
932 }
933
934 if (llvm::ConstantDataSequential *CDS =
935 dyn_cast<llvm::ConstantDataSequential>(Val: Init)) {
936 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
937 llvm::Constant *Elt = CDS->getElementAsConstant(i);
938 if (!canEmitInitWithFewStoresAfterBZero(Init: Elt, NumStores))
939 return false;
940 }
941 return true;
942 }
943
944 // Anything else is hard and scary.
945 return false;
946}
947
948/// For inits that canEmitInitWithFewStoresAfterBZero returned true for, emit
949/// the scalar stores that would be required.
950static void emitStoresForInitAfterBZero(CodeGenModule &CGM,
951 llvm::Constant *Init, Address Loc,
952 bool isVolatile, CGBuilderTy &Builder,
953 bool IsAutoInit) {
954 assert(!Init->isNullValue() && !isa<llvm::UndefValue>(Init) &&
955 "called emitStoresForInitAfterBZero for zero or undef value.");
956
957 if (isa<llvm::ConstantInt>(Val: Init) || isa<llvm::ConstantFP>(Val: Init) ||
958 isa<llvm::ConstantVector>(Val: Init) || isa<llvm::BlockAddress>(Val: Init) ||
959 isa<llvm::ConstantExpr>(Val: Init)) {
960 auto *I = Builder.CreateStore(Val: Init, Addr: Loc, IsVolatile: isVolatile);
961 if (IsAutoInit)
962 I->addAnnotationMetadata(Annotation: "auto-init");
963 return;
964 }
965
966 if (llvm::ConstantDataSequential *CDS =
967 dyn_cast<llvm::ConstantDataSequential>(Val: Init)) {
968 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
969 llvm::Constant *Elt = CDS->getElementAsConstant(i);
970
971 // If necessary, get a pointer to the element and emit it.
972 if (!Elt->isNullValue() && !isa<llvm::UndefValue>(Val: Elt))
973 emitStoresForInitAfterBZero(
974 CGM, Init: Elt, Loc: Builder.CreateConstInBoundsGEP2_32(Addr: Loc, Idx0: 0, Idx1: i), isVolatile,
975 Builder, IsAutoInit);
976 }
977 return;
978 }
979
980 assert((isa<llvm::ConstantStruct>(Init) || isa<llvm::ConstantArray>(Init)) &&
981 "Unknown value type!");
982
983 for (unsigned i = 0, e = Init->getNumOperands(); i != e; ++i) {
984 llvm::Constant *Elt = cast<llvm::Constant>(Val: Init->getOperand(i));
985
986 // If necessary, get a pointer to the element and emit it.
987 if (!Elt->isNullValue() && !isa<llvm::UndefValue>(Val: Elt))
988 emitStoresForInitAfterBZero(CGM, Init: Elt,
989 Loc: Builder.CreateConstInBoundsGEP2_32(Addr: Loc, Idx0: 0, Idx1: i),
990 isVolatile, Builder, IsAutoInit);
991 }
992}
993
994/// Decide whether we should use bzero plus some stores to initialize a local
995/// variable instead of using a memcpy from a constant global. It is beneficial
996/// to use bzero if the global is all zeros, or mostly zeros and large.
997static bool shouldUseBZeroPlusStoresToInitialize(llvm::Constant *Init,
998 uint64_t GlobalSize) {
999 // If a global is all zeros, always use a bzero.
1000 if (isa<llvm::ConstantAggregateZero>(Val: Init)) return true;
1001
1002 // If a non-zero global is <= 32 bytes, always use a memcpy. If it is large,
1003 // do it if it will require 6 or fewer scalar stores.
1004 // TODO: Should budget depends on the size? Avoiding a large global warrants
1005 // plopping in more stores.
1006 unsigned StoreBudget = 6;
1007 uint64_t SizeLimit = 32;
1008
1009 return GlobalSize > SizeLimit &&
1010 canEmitInitWithFewStoresAfterBZero(Init, NumStores&: StoreBudget);
1011}
1012
1013/// Decide whether we should use memset to initialize a local variable instead
1014/// of using a memcpy from a constant global. Assumes we've already decided to
1015/// not user bzero.
1016/// FIXME We could be more clever, as we are for bzero above, and generate
1017/// memset followed by stores. It's unclear that's worth the effort.
1018static llvm::Value *shouldUseMemSetToInitialize(llvm::Constant *Init,
1019 uint64_t GlobalSize,
1020 const llvm::DataLayout &DL) {
1021 uint64_t SizeLimit = 32;
1022 if (GlobalSize <= SizeLimit)
1023 return nullptr;
1024 return llvm::isBytewiseValue(V: Init, DL);
1025}
1026
1027/// Decide whether we want to split a constant structure or array store into a
1028/// sequence of its fields' stores. This may cost us code size and compilation
1029/// speed, but plays better with store optimizations.
1030static bool shouldSplitConstantStore(CodeGenModule &CGM,
1031 uint64_t GlobalByteSize) {
1032 // Don't break things that occupy more than one cacheline.
1033 uint64_t ByteSizeLimit = 64;
1034 if (CGM.getCodeGenOpts().OptimizationLevel == 0)
1035 return false;
1036 if (GlobalByteSize <= ByteSizeLimit)
1037 return true;
1038 return false;
1039}
1040
1041enum class IsPattern { No, Yes };
1042
1043/// Generate a constant filled with either a pattern or zeroes.
1044static llvm::Constant *patternOrZeroFor(CodeGenModule &CGM, IsPattern isPattern,
1045 llvm::Type *Ty) {
1046 if (isPattern == IsPattern::Yes)
1047 return initializationPatternFor(CGM, Ty);
1048 else
1049 return llvm::Constant::getNullValue(Ty);
1050}
1051
1052static llvm::Constant *constWithPadding(CodeGenModule &CGM, IsPattern isPattern,
1053 llvm::Constant *constant);
1054
1055/// Helper function for constWithPadding() to deal with padding in structures.
1056static llvm::Constant *constStructWithPadding(CodeGenModule &CGM,
1057 IsPattern isPattern,
1058 llvm::StructType *STy,
1059 llvm::Constant *constant) {
1060 const llvm::DataLayout &DL = CGM.getDataLayout();
1061 const llvm::StructLayout *Layout = DL.getStructLayout(Ty: STy);
1062 llvm::Type *Int8Ty = llvm::IntegerType::getInt8Ty(C&: CGM.getLLVMContext());
1063 unsigned SizeSoFar = 0;
1064 SmallVector<llvm::Constant *, 8> Values;
1065 bool NestedIntact = true;
1066 for (unsigned i = 0, e = STy->getNumElements(); i != e; i++) {
1067 unsigned CurOff = Layout->getElementOffset(Idx: i);
1068 if (SizeSoFar < CurOff) {
1069 assert(!STy->isPacked());
1070 auto *PadTy = llvm::ArrayType::get(ElementType: Int8Ty, NumElements: CurOff - SizeSoFar);
1071 Values.push_back(Elt: patternOrZeroFor(CGM, isPattern, Ty: PadTy));
1072 }
1073 llvm::Constant *CurOp;
1074 if (constant->isZeroValue())
1075 CurOp = llvm::Constant::getNullValue(Ty: STy->getElementType(N: i));
1076 else
1077 CurOp = cast<llvm::Constant>(Val: constant->getAggregateElement(Elt: i));
1078 auto *NewOp = constWithPadding(CGM, isPattern, constant: CurOp);
1079 if (CurOp != NewOp)
1080 NestedIntact = false;
1081 Values.push_back(Elt: NewOp);
1082 SizeSoFar = CurOff + DL.getTypeAllocSize(Ty: CurOp->getType());
1083 }
1084 unsigned TotalSize = Layout->getSizeInBytes();
1085 if (SizeSoFar < TotalSize) {
1086 auto *PadTy = llvm::ArrayType::get(ElementType: Int8Ty, NumElements: TotalSize - SizeSoFar);
1087 Values.push_back(Elt: patternOrZeroFor(CGM, isPattern, Ty: PadTy));
1088 }
1089 if (NestedIntact && Values.size() == STy->getNumElements())
1090 return constant;
1091 return llvm::ConstantStruct::getAnon(V: Values, Packed: STy->isPacked());
1092}
1093
1094/// Replace all padding bytes in a given constant with either a pattern byte or
1095/// 0x00.
1096static llvm::Constant *constWithPadding(CodeGenModule &CGM, IsPattern isPattern,
1097 llvm::Constant *constant) {
1098 llvm::Type *OrigTy = constant->getType();
1099 if (const auto STy = dyn_cast<llvm::StructType>(Val: OrigTy))
1100 return constStructWithPadding(CGM, isPattern, STy, constant);
1101 if (auto *ArrayTy = dyn_cast<llvm::ArrayType>(Val: OrigTy)) {
1102 llvm::SmallVector<llvm::Constant *, 8> Values;
1103 uint64_t Size = ArrayTy->getNumElements();
1104 if (!Size)
1105 return constant;
1106 llvm::Type *ElemTy = ArrayTy->getElementType();
1107 bool ZeroInitializer = constant->isNullValue();
1108 llvm::Constant *OpValue, *PaddedOp;
1109 if (ZeroInitializer) {
1110 OpValue = llvm::Constant::getNullValue(Ty: ElemTy);
1111 PaddedOp = constWithPadding(CGM, isPattern, constant: OpValue);
1112 }
1113 for (unsigned Op = 0; Op != Size; ++Op) {
1114 if (!ZeroInitializer) {
1115 OpValue = constant->getAggregateElement(Elt: Op);
1116 PaddedOp = constWithPadding(CGM, isPattern, constant: OpValue);
1117 }
1118 Values.push_back(Elt: PaddedOp);
1119 }
1120 auto *NewElemTy = Values[0]->getType();
1121 if (NewElemTy == ElemTy)
1122 return constant;
1123 auto *NewArrayTy = llvm::ArrayType::get(ElementType: NewElemTy, NumElements: Size);
1124 return llvm::ConstantArray::get(T: NewArrayTy, V: Values);
1125 }
1126 // FIXME: Add handling for tail padding in vectors. Vectors don't
1127 // have padding between or inside elements, but the total amount of
1128 // data can be less than the allocated size.
1129 return constant;
1130}
1131
1132Address CodeGenModule::createUnnamedGlobalFrom(const VarDecl &D,
1133 llvm::Constant *Constant,
1134 CharUnits Align) {
1135 auto FunctionName = [&](const DeclContext *DC) -> std::string {
1136 if (const auto *FD = dyn_cast<FunctionDecl>(Val: DC)) {
1137 if (const auto *CC = dyn_cast<CXXConstructorDecl>(Val: FD))
1138 return CC->getNameAsString();
1139 if (const auto *CD = dyn_cast<CXXDestructorDecl>(Val: FD))
1140 return CD->getNameAsString();
1141 return std::string(getMangledName(GD: FD));
1142 } else if (const auto *OM = dyn_cast<ObjCMethodDecl>(Val: DC)) {
1143 return OM->getNameAsString();
1144 } else if (isa<BlockDecl>(Val: DC)) {
1145 return "<block>";
1146 } else if (isa<CapturedDecl>(Val: DC)) {
1147 return "<captured>";
1148 } else {
1149 llvm_unreachable("expected a function or method");
1150 }
1151 };
1152
1153 // Form a simple per-variable cache of these values in case we find we
1154 // want to reuse them.
1155 llvm::GlobalVariable *&CacheEntry = InitializerConstants[&D];
1156 if (!CacheEntry || CacheEntry->getInitializer() != Constant) {
1157 auto *Ty = Constant->getType();
1158 bool isConstant = true;
1159 llvm::GlobalVariable *InsertBefore = nullptr;
1160 unsigned AS =
1161 getContext().getTargetAddressSpace(AS: GetGlobalConstantAddressSpace());
1162 std::string Name;
1163 if (D.hasGlobalStorage())
1164 Name = getMangledName(GD: &D).str() + ".const";
1165 else if (const DeclContext *DC = D.getParentFunctionOrMethod())
1166 Name = ("__const." + FunctionName(DC) + "." + D.getName()).str();
1167 else
1168 llvm_unreachable("local variable has no parent function or method");
1169 llvm::GlobalVariable *GV = new llvm::GlobalVariable(
1170 getModule(), Ty, isConstant, llvm::GlobalValue::PrivateLinkage,
1171 Constant, Name, InsertBefore, llvm::GlobalValue::NotThreadLocal, AS);
1172 GV->setAlignment(Align.getAsAlign());
1173 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1174 CacheEntry = GV;
1175 } else if (CacheEntry->getAlignment() < uint64_t(Align.getQuantity())) {
1176 CacheEntry->setAlignment(Align.getAsAlign());
1177 }
1178
1179 return Address(CacheEntry, CacheEntry->getValueType(), Align);
1180}
1181
1182static Address createUnnamedGlobalForMemcpyFrom(CodeGenModule &CGM,
1183 const VarDecl &D,
1184 CGBuilderTy &Builder,
1185 llvm::Constant *Constant,
1186 CharUnits Align) {
1187 Address SrcPtr = CGM.createUnnamedGlobalFrom(D, Constant, Align);
1188 return SrcPtr.withElementType(ElemTy: CGM.Int8Ty);
1189}
1190
1191static void emitStoresForConstant(CodeGenModule &CGM, const VarDecl &D,
1192 Address Loc, bool isVolatile,
1193 CGBuilderTy &Builder,
1194 llvm::Constant *constant, bool IsAutoInit) {
1195 auto *Ty = constant->getType();
1196 uint64_t ConstantSize = CGM.getDataLayout().getTypeAllocSize(Ty);
1197 if (!ConstantSize)
1198 return;
1199
1200 bool canDoSingleStore = Ty->isIntOrIntVectorTy() ||
1201 Ty->isPtrOrPtrVectorTy() || Ty->isFPOrFPVectorTy();
1202 if (canDoSingleStore) {
1203 auto *I = Builder.CreateStore(Val: constant, Addr: Loc, IsVolatile: isVolatile);
1204 if (IsAutoInit)
1205 I->addAnnotationMetadata(Annotation: "auto-init");
1206 return;
1207 }
1208
1209 auto *SizeVal = llvm::ConstantInt::get(Ty: CGM.IntPtrTy, V: ConstantSize);
1210
1211 // If the initializer is all or mostly the same, codegen with bzero / memset
1212 // then do a few stores afterward.
1213 if (shouldUseBZeroPlusStoresToInitialize(Init: constant, GlobalSize: ConstantSize)) {
1214 auto *I = Builder.CreateMemSet(Dest: Loc, Value: llvm::ConstantInt::get(Ty: CGM.Int8Ty, V: 0),
1215 Size: SizeVal, IsVolatile: isVolatile);
1216 if (IsAutoInit)
1217 I->addAnnotationMetadata(Annotation: "auto-init");
1218
1219 bool valueAlreadyCorrect =
1220 constant->isNullValue() || isa<llvm::UndefValue>(Val: constant);
1221 if (!valueAlreadyCorrect) {
1222 Loc = Loc.withElementType(ElemTy: Ty);
1223 emitStoresForInitAfterBZero(CGM, Init: constant, Loc, isVolatile, Builder,
1224 IsAutoInit);
1225 }
1226 return;
1227 }
1228
1229 // If the initializer is a repeated byte pattern, use memset.
1230 llvm::Value *Pattern =
1231 shouldUseMemSetToInitialize(Init: constant, GlobalSize: ConstantSize, DL: CGM.getDataLayout());
1232 if (Pattern) {
1233 uint64_t Value = 0x00;
1234 if (!isa<llvm::UndefValue>(Val: Pattern)) {
1235 const llvm::APInt &AP = cast<llvm::ConstantInt>(Val: Pattern)->getValue();
1236 assert(AP.getBitWidth() <= 8);
1237 Value = AP.getLimitedValue();
1238 }
1239 auto *I = Builder.CreateMemSet(
1240 Dest: Loc, Value: llvm::ConstantInt::get(Ty: CGM.Int8Ty, V: Value), Size: SizeVal, IsVolatile: isVolatile);
1241 if (IsAutoInit)
1242 I->addAnnotationMetadata(Annotation: "auto-init");
1243 return;
1244 }
1245
1246 // If the initializer is small or trivialAutoVarInit is set, use a handful of
1247 // stores.
1248 bool IsTrivialAutoVarInitPattern =
1249 CGM.getContext().getLangOpts().getTrivialAutoVarInit() ==
1250 LangOptions::TrivialAutoVarInitKind::Pattern;
1251 if (shouldSplitConstantStore(CGM, GlobalByteSize: ConstantSize)) {
1252 if (auto *STy = dyn_cast<llvm::StructType>(Val: Ty)) {
1253 if (STy == Loc.getElementType() ||
1254 (STy != Loc.getElementType() && IsTrivialAutoVarInitPattern)) {
1255 const llvm::StructLayout *Layout =
1256 CGM.getDataLayout().getStructLayout(Ty: STy);
1257 for (unsigned i = 0; i != constant->getNumOperands(); i++) {
1258 CharUnits CurOff =
1259 CharUnits::fromQuantity(Quantity: Layout->getElementOffset(Idx: i));
1260 Address EltPtr = Builder.CreateConstInBoundsByteGEP(
1261 Addr: Loc.withElementType(ElemTy: CGM.Int8Ty), Offset: CurOff);
1262 emitStoresForConstant(CGM, D, Loc: EltPtr, isVolatile, Builder,
1263 constant: constant->getAggregateElement(Elt: i), IsAutoInit);
1264 }
1265 return;
1266 }
1267 } else if (auto *ATy = dyn_cast<llvm::ArrayType>(Val: Ty)) {
1268 if (ATy == Loc.getElementType() ||
1269 (ATy != Loc.getElementType() && IsTrivialAutoVarInitPattern)) {
1270 for (unsigned i = 0; i != ATy->getNumElements(); i++) {
1271 Address EltPtr = Builder.CreateConstGEP(
1272 Addr: Loc.withElementType(ElemTy: ATy->getElementType()), Index: i);
1273 emitStoresForConstant(CGM, D, Loc: EltPtr, isVolatile, Builder,
1274 constant: constant->getAggregateElement(Elt: i), IsAutoInit);
1275 }
1276 return;
1277 }
1278 }
1279 }
1280
1281 // Copy from a global.
1282 auto *I =
1283 Builder.CreateMemCpy(Dest: Loc,
1284 Src: createUnnamedGlobalForMemcpyFrom(
1285 CGM, D, Builder, Constant: constant, Align: Loc.getAlignment()),
1286 Size: SizeVal, IsVolatile: isVolatile);
1287 if (IsAutoInit)
1288 I->addAnnotationMetadata(Annotation: "auto-init");
1289}
1290
1291static void emitStoresForZeroInit(CodeGenModule &CGM, const VarDecl &D,
1292 Address Loc, bool isVolatile,
1293 CGBuilderTy &Builder) {
1294 llvm::Type *ElTy = Loc.getElementType();
1295 llvm::Constant *constant =
1296 constWithPadding(CGM, isPattern: IsPattern::No, constant: llvm::Constant::getNullValue(Ty: ElTy));
1297 emitStoresForConstant(CGM, D, Loc, isVolatile, Builder, constant,
1298 /*IsAutoInit=*/true);
1299}
1300
1301static void emitStoresForPatternInit(CodeGenModule &CGM, const VarDecl &D,
1302 Address Loc, bool isVolatile,
1303 CGBuilderTy &Builder) {
1304 llvm::Type *ElTy = Loc.getElementType();
1305 llvm::Constant *constant = constWithPadding(
1306 CGM, isPattern: IsPattern::Yes, constant: initializationPatternFor(CGM, ElTy));
1307 assert(!isa<llvm::UndefValue>(constant));
1308 emitStoresForConstant(CGM, D, Loc, isVolatile, Builder, constant,
1309 /*IsAutoInit=*/true);
1310}
1311
1312static bool containsUndef(llvm::Constant *constant) {
1313 auto *Ty = constant->getType();
1314 if (isa<llvm::UndefValue>(Val: constant))
1315 return true;
1316 if (Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy())
1317 for (llvm::Use &Op : constant->operands())
1318 if (containsUndef(constant: cast<llvm::Constant>(Val&: Op)))
1319 return true;
1320 return false;
1321}
1322
1323static llvm::Constant *replaceUndef(CodeGenModule &CGM, IsPattern isPattern,
1324 llvm::Constant *constant) {
1325 auto *Ty = constant->getType();
1326 if (isa<llvm::UndefValue>(Val: constant))
1327 return patternOrZeroFor(CGM, isPattern, Ty);
1328 if (!(Ty->isStructTy() || Ty->isArrayTy() || Ty->isVectorTy()))
1329 return constant;
1330 if (!containsUndef(constant))
1331 return constant;
1332 llvm::SmallVector<llvm::Constant *, 8> Values(constant->getNumOperands());
1333 for (unsigned Op = 0, NumOp = constant->getNumOperands(); Op != NumOp; ++Op) {
1334 auto *OpValue = cast<llvm::Constant>(Val: constant->getOperand(i: Op));
1335 Values[Op] = replaceUndef(CGM, isPattern, constant: OpValue);
1336 }
1337 if (Ty->isStructTy())
1338 return llvm::ConstantStruct::get(T: cast<llvm::StructType>(Val: Ty), V: Values);
1339 if (Ty->isArrayTy())
1340 return llvm::ConstantArray::get(T: cast<llvm::ArrayType>(Val: Ty), V: Values);
1341 assert(Ty->isVectorTy());
1342 return llvm::ConstantVector::get(V: Values);
1343}
1344
1345/// EmitAutoVarDecl - Emit code and set up an entry in LocalDeclMap for a
1346/// variable declaration with auto, register, or no storage class specifier.
1347/// These turn into simple stack objects, or GlobalValues depending on target.
1348void CodeGenFunction::EmitAutoVarDecl(const VarDecl &D) {
1349 AutoVarEmission emission = EmitAutoVarAlloca(var: D);
1350 EmitAutoVarInit(emission);
1351 EmitAutoVarCleanups(emission);
1352}
1353
1354/// Emit a lifetime.begin marker if some criteria are satisfied.
1355/// \return a pointer to the temporary size Value if a marker was emitted, null
1356/// otherwise
1357llvm::Value *CodeGenFunction::EmitLifetimeStart(llvm::TypeSize Size,
1358 llvm::Value *Addr) {
1359 if (!ShouldEmitLifetimeMarkers)
1360 return nullptr;
1361
1362 assert(Addr->getType()->getPointerAddressSpace() ==
1363 CGM.getDataLayout().getAllocaAddrSpace() &&
1364 "Pointer should be in alloca address space");
1365 llvm::Value *SizeV = llvm::ConstantInt::get(
1366 Ty: Int64Ty, V: Size.isScalable() ? -1 : Size.getFixedValue());
1367 llvm::CallInst *C =
1368 Builder.CreateCall(Callee: CGM.getLLVMLifetimeStartFn(), Args: {SizeV, Addr});
1369 C->setDoesNotThrow();
1370 return SizeV;
1371}
1372
1373void CodeGenFunction::EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr) {
1374 assert(Addr->getType()->getPointerAddressSpace() ==
1375 CGM.getDataLayout().getAllocaAddrSpace() &&
1376 "Pointer should be in alloca address space");
1377 llvm::CallInst *C =
1378 Builder.CreateCall(Callee: CGM.getLLVMLifetimeEndFn(), Args: {Size, Addr});
1379 C->setDoesNotThrow();
1380}
1381
1382void CodeGenFunction::EmitAndRegisterVariableArrayDimensions(
1383 CGDebugInfo *DI, const VarDecl &D, bool EmitDebugInfo) {
1384 // For each dimension stores its QualType and corresponding
1385 // size-expression Value.
1386 SmallVector<CodeGenFunction::VlaSizePair, 4> Dimensions;
1387 SmallVector<const IdentifierInfo *, 4> VLAExprNames;
1388
1389 // Break down the array into individual dimensions.
1390 QualType Type1D = D.getType();
1391 while (getContext().getAsVariableArrayType(T: Type1D)) {
1392 auto VlaSize = getVLAElements1D(vla: Type1D);
1393 if (auto *C = dyn_cast<llvm::ConstantInt>(Val: VlaSize.NumElts))
1394 Dimensions.emplace_back(Args&: C, Args: Type1D.getUnqualifiedType());
1395 else {
1396 // Generate a locally unique name for the size expression.
1397 Twine Name = Twine("__vla_expr") + Twine(VLAExprCounter++);
1398 SmallString<12> Buffer;
1399 StringRef NameRef = Name.toStringRef(Out&: Buffer);
1400 auto &Ident = getContext().Idents.getOwn(Name: NameRef);
1401 VLAExprNames.push_back(Elt: &Ident);
1402 auto SizeExprAddr =
1403 CreateDefaultAlignTempAlloca(Ty: VlaSize.NumElts->getType(), Name: NameRef);
1404 Builder.CreateStore(Val: VlaSize.NumElts, Addr: SizeExprAddr);
1405 Dimensions.emplace_back(Args: SizeExprAddr.getPointer(),
1406 Args: Type1D.getUnqualifiedType());
1407 }
1408 Type1D = VlaSize.Type;
1409 }
1410
1411 if (!EmitDebugInfo)
1412 return;
1413
1414 // Register each dimension's size-expression with a DILocalVariable,
1415 // so that it can be used by CGDebugInfo when instantiating a DISubrange
1416 // to describe this array.
1417 unsigned NameIdx = 0;
1418 for (auto &VlaSize : Dimensions) {
1419 llvm::Metadata *MD;
1420 if (auto *C = dyn_cast<llvm::ConstantInt>(Val: VlaSize.NumElts))
1421 MD = llvm::ConstantAsMetadata::get(C);
1422 else {
1423 // Create an artificial VarDecl to generate debug info for.
1424 const IdentifierInfo *NameIdent = VLAExprNames[NameIdx++];
1425 auto QT = getContext().getIntTypeForBitwidth(
1426 DestWidth: SizeTy->getScalarSizeInBits(), Signed: false);
1427 auto *ArtificialDecl = VarDecl::Create(
1428 C&: getContext(), DC: const_cast<DeclContext *>(D.getDeclContext()),
1429 StartLoc: D.getLocation(), IdLoc: D.getLocation(), Id: NameIdent, T: QT,
1430 TInfo: getContext().CreateTypeSourceInfo(T: QT), S: SC_Auto);
1431 ArtificialDecl->setImplicit();
1432
1433 MD = DI->EmitDeclareOfAutoVariable(Decl: ArtificialDecl, AI: VlaSize.NumElts,
1434 Builder);
1435 }
1436 assert(MD && "No Size expression debug node created");
1437 DI->registerVLASizeExpression(Ty: VlaSize.Type, SizeExpr: MD);
1438 }
1439}
1440
1441/// EmitAutoVarAlloca - Emit the alloca and debug information for a
1442/// local variable. Does not emit initialization or destruction.
1443CodeGenFunction::AutoVarEmission
1444CodeGenFunction::EmitAutoVarAlloca(const VarDecl &D) {
1445 QualType Ty = D.getType();
1446 assert(
1447 Ty.getAddressSpace() == LangAS::Default ||
1448 (Ty.getAddressSpace() == LangAS::opencl_private && getLangOpts().OpenCL));
1449
1450 AutoVarEmission emission(D);
1451
1452 bool isEscapingByRef = D.isEscapingByref();
1453 emission.IsEscapingByRef = isEscapingByRef;
1454
1455 CharUnits alignment = getContext().getDeclAlign(D: &D);
1456
1457 // If the type is variably-modified, emit all the VLA sizes for it.
1458 if (Ty->isVariablyModifiedType())
1459 EmitVariablyModifiedType(Ty);
1460
1461 auto *DI = getDebugInfo();
1462 bool EmitDebugInfo = DI && CGM.getCodeGenOpts().hasReducedDebugInfo();
1463
1464 Address address = Address::invalid();
1465 RawAddress AllocaAddr = RawAddress::invalid();
1466 Address OpenMPLocalAddr = Address::invalid();
1467 if (CGM.getLangOpts().OpenMPIRBuilder)
1468 OpenMPLocalAddr = OMPBuilderCBHelpers::getAddressOfLocalVariable(CGF&: *this, VD: &D);
1469 else
1470 OpenMPLocalAddr =
1471 getLangOpts().OpenMP
1472 ? CGM.getOpenMPRuntime().getAddressOfLocalVariable(CGF&: *this, VD: &D)
1473 : Address::invalid();
1474
1475 bool NRVO = getLangOpts().ElideConstructors && D.isNRVOVariable();
1476
1477 if (getLangOpts().OpenMP && OpenMPLocalAddr.isValid()) {
1478 address = OpenMPLocalAddr;
1479 AllocaAddr = OpenMPLocalAddr;
1480 } else if (Ty->isConstantSizeType()) {
1481 // If this value is an array or struct with a statically determinable
1482 // constant initializer, there are optimizations we can do.
1483 //
1484 // TODO: We should constant-evaluate the initializer of any variable,
1485 // as long as it is initialized by a constant expression. Currently,
1486 // isConstantInitializer produces wrong answers for structs with
1487 // reference or bitfield members, and a few other cases, and checking
1488 // for POD-ness protects us from some of these.
1489 if (D.getInit() && (Ty->isArrayType() || Ty->isRecordType()) &&
1490 (D.isConstexpr() ||
1491 ((Ty.isPODType(Context: getContext()) ||
1492 getContext().getBaseElementType(QT: Ty)->isObjCObjectPointerType()) &&
1493 D.getInit()->isConstantInitializer(Ctx&: getContext(), ForRef: false)))) {
1494
1495 // If the variable's a const type, and it's neither an NRVO
1496 // candidate nor a __block variable and has no mutable members,
1497 // emit it as a global instead.
1498 // Exception is if a variable is located in non-constant address space
1499 // in OpenCL.
1500 bool NeedsDtor =
1501 D.needsDestruction(Ctx: getContext()) == QualType::DK_cxx_destructor;
1502 if ((!getLangOpts().OpenCL ||
1503 Ty.getAddressSpace() == LangAS::opencl_constant) &&
1504 (CGM.getCodeGenOpts().MergeAllConstants && !NRVO &&
1505 !isEscapingByRef &&
1506 Ty.isConstantStorage(Ctx: getContext(), ExcludeCtor: true, ExcludeDtor: !NeedsDtor))) {
1507 EmitStaticVarDecl(D, Linkage: llvm::GlobalValue::InternalLinkage);
1508
1509 // Signal this condition to later callbacks.
1510 emission.Addr = Address::invalid();
1511 assert(emission.wasEmittedAsGlobal());
1512 return emission;
1513 }
1514
1515 // Otherwise, tell the initialization code that we're in this case.
1516 emission.IsConstantAggregate = true;
1517 }
1518
1519 // A normal fixed sized variable becomes an alloca in the entry block,
1520 // unless:
1521 // - it's an NRVO variable.
1522 // - we are compiling OpenMP and it's an OpenMP local variable.
1523 if (NRVO) {
1524 // The named return value optimization: allocate this variable in the
1525 // return slot, so that we can elide the copy when returning this
1526 // variable (C++0x [class.copy]p34).
1527 address = ReturnValue;
1528 AllocaAddr =
1529 RawAddress(ReturnValue.emitRawPointer(CGF&: *this),
1530 ReturnValue.getElementType(), ReturnValue.getAlignment());
1531 ;
1532
1533 if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
1534 const auto *RD = RecordTy->getDecl();
1535 const auto *CXXRD = dyn_cast<CXXRecordDecl>(Val: RD);
1536 if ((CXXRD && !CXXRD->hasTrivialDestructor()) ||
1537 RD->isNonTrivialToPrimitiveDestroy()) {
1538 // Create a flag that is used to indicate when the NRVO was applied
1539 // to this variable. Set it to zero to indicate that NRVO was not
1540 // applied.
1541 llvm::Value *Zero = Builder.getFalse();
1542 RawAddress NRVOFlag =
1543 CreateTempAlloca(Ty: Zero->getType(), align: CharUnits::One(), Name: "nrvo");
1544 EnsureInsertPoint();
1545 Builder.CreateStore(Val: Zero, Addr: NRVOFlag);
1546
1547 // Record the NRVO flag for this variable.
1548 NRVOFlags[&D] = NRVOFlag.getPointer();
1549 emission.NRVOFlag = NRVOFlag.getPointer();
1550 }
1551 }
1552 } else {
1553 CharUnits allocaAlignment;
1554 llvm::Type *allocaTy;
1555 if (isEscapingByRef) {
1556 auto &byrefInfo = getBlockByrefInfo(var: &D);
1557 allocaTy = byrefInfo.Type;
1558 allocaAlignment = byrefInfo.ByrefAlignment;
1559 } else {
1560 allocaTy = ConvertTypeForMem(T: Ty);
1561 allocaAlignment = alignment;
1562 }
1563
1564 // Create the alloca. Note that we set the name separately from
1565 // building the instruction so that it's there even in no-asserts
1566 // builds.
1567 address = CreateTempAlloca(Ty: allocaTy, align: allocaAlignment, Name: D.getName(),
1568 /*ArraySize=*/nullptr, Alloca: &AllocaAddr);
1569
1570 // Don't emit lifetime markers for MSVC catch parameters. The lifetime of
1571 // the catch parameter starts in the catchpad instruction, and we can't
1572 // insert code in those basic blocks.
1573 bool IsMSCatchParam =
1574 D.isExceptionVariable() && getTarget().getCXXABI().isMicrosoft();
1575
1576 // Emit a lifetime intrinsic if meaningful. There's no point in doing this
1577 // if we don't have a valid insertion point (?).
1578 if (HaveInsertPoint() && !IsMSCatchParam) {
1579 // If there's a jump into the lifetime of this variable, its lifetime
1580 // gets broken up into several regions in IR, which requires more work
1581 // to handle correctly. For now, just omit the intrinsics; this is a
1582 // rare case, and it's better to just be conservatively correct.
1583 // PR28267.
1584 //
1585 // We have to do this in all language modes if there's a jump past the
1586 // declaration. We also have to do it in C if there's a jump to an
1587 // earlier point in the current block because non-VLA lifetimes begin as
1588 // soon as the containing block is entered, not when its variables
1589 // actually come into scope; suppressing the lifetime annotations
1590 // completely in this case is unnecessarily pessimistic, but again, this
1591 // is rare.
1592 if (!Bypasses.IsBypassed(D: &D) &&
1593 !(!getLangOpts().CPlusPlus && hasLabelBeenSeenInCurrentScope())) {
1594 llvm::TypeSize Size = CGM.getDataLayout().getTypeAllocSize(Ty: allocaTy);
1595 emission.SizeForLifetimeMarkers =
1596 EmitLifetimeStart(Size, Addr: AllocaAddr.getPointer());
1597 }
1598 } else {
1599 assert(!emission.useLifetimeMarkers());
1600 }
1601 }
1602 } else {
1603 EnsureInsertPoint();
1604
1605 // Delayed globalization for variable length declarations. This ensures that
1606 // the expression representing the length has been emitted and can be used
1607 // by the definition of the VLA. Since this is an escaped declaration, in
1608 // OpenMP we have to use a call to __kmpc_alloc_shared(). The matching
1609 // deallocation call to __kmpc_free_shared() is emitted later.
1610 bool VarAllocated = false;
1611 if (getLangOpts().OpenMPIsTargetDevice) {
1612 auto &RT = CGM.getOpenMPRuntime();
1613 if (RT.isDelayedVariableLengthDecl(CGF&: *this, VD: &D)) {
1614 // Emit call to __kmpc_alloc_shared() instead of the alloca.
1615 std::pair<llvm::Value *, llvm::Value *> AddrSizePair =
1616 RT.getKmpcAllocShared(CGF&: *this, VD: &D);
1617
1618 // Save the address of the allocation:
1619 LValue Base = MakeAddrLValue(V: AddrSizePair.first, T: D.getType(),
1620 Alignment: CGM.getContext().getDeclAlign(D: &D),
1621 Source: AlignmentSource::Decl);
1622 address = Base.getAddress();
1623
1624 // Push a cleanup block to emit the call to __kmpc_free_shared in the
1625 // appropriate location at the end of the scope of the
1626 // __kmpc_alloc_shared functions:
1627 pushKmpcAllocFree(Kind: NormalCleanup, AddrSizePair);
1628
1629 // Mark variable as allocated:
1630 VarAllocated = true;
1631 }
1632 }
1633
1634 if (!VarAllocated) {
1635 if (!DidCallStackSave) {
1636 // Save the stack.
1637 Address Stack =
1638 CreateDefaultAlignTempAlloca(Ty: AllocaInt8PtrTy, Name: "saved_stack");
1639
1640 llvm::Value *V = Builder.CreateStackSave();
1641 assert(V->getType() == AllocaInt8PtrTy);
1642 Builder.CreateStore(Val: V, Addr: Stack);
1643
1644 DidCallStackSave = true;
1645
1646 // Push a cleanup block and restore the stack there.
1647 // FIXME: in general circumstances, this should be an EH cleanup.
1648 pushStackRestore(kind: NormalCleanup, SPMem: Stack);
1649 }
1650
1651 auto VlaSize = getVLASize(vla: Ty);
1652 llvm::Type *llvmTy = ConvertTypeForMem(T: VlaSize.Type);
1653
1654 // Allocate memory for the array.
1655 address = CreateTempAlloca(Ty: llvmTy, align: alignment, Name: "vla", ArraySize: VlaSize.NumElts,
1656 Alloca: &AllocaAddr);
1657 }
1658
1659 // If we have debug info enabled, properly describe the VLA dimensions for
1660 // this type by registering the vla size expression for each of the
1661 // dimensions.
1662 EmitAndRegisterVariableArrayDimensions(DI, D, EmitDebugInfo);
1663 }
1664
1665 setAddrOfLocalVar(VD: &D, Addr: address);
1666 emission.Addr = address;
1667 emission.AllocaAddr = AllocaAddr;
1668
1669 // Emit debug info for local var declaration.
1670 if (EmitDebugInfo && HaveInsertPoint()) {
1671 Address DebugAddr = address;
1672 bool UsePointerValue = NRVO && ReturnValuePointer.isValid();
1673 DI->setLocation(D.getLocation());
1674
1675 // If NRVO, use a pointer to the return address.
1676 if (UsePointerValue) {
1677 DebugAddr = ReturnValuePointer;
1678 AllocaAddr = ReturnValuePointer;
1679 }
1680 (void)DI->EmitDeclareOfAutoVariable(Decl: &D, AI: AllocaAddr.getPointer(), Builder,
1681 UsePointerValue);
1682 }
1683
1684 if (D.hasAttr<AnnotateAttr>() && HaveInsertPoint())
1685 EmitVarAnnotations(D: &D, V: address.emitRawPointer(CGF&: *this));
1686
1687 // Make sure we call @llvm.lifetime.end.
1688 if (emission.useLifetimeMarkers())
1689 EHStack.pushCleanup<CallLifetimeEnd>(Kind: NormalEHLifetimeMarker,
1690 A: emission.getOriginalAllocatedAddress(),
1691 A: emission.getSizeForLifetimeMarkers());
1692
1693 return emission;
1694}
1695
1696static bool isCapturedBy(const VarDecl &, const Expr *);
1697
1698/// Determines whether the given __block variable is potentially
1699/// captured by the given statement.
1700static bool isCapturedBy(const VarDecl &Var, const Stmt *S) {
1701 if (const Expr *E = dyn_cast<Expr>(Val: S))
1702 return isCapturedBy(Var, E);
1703 for (const Stmt *SubStmt : S->children())
1704 if (isCapturedBy(Var, S: SubStmt))
1705 return true;
1706 return false;
1707}
1708
1709/// Determines whether the given __block variable is potentially
1710/// captured by the given expression.
1711static bool isCapturedBy(const VarDecl &Var, const Expr *E) {
1712 // Skip the most common kinds of expressions that make
1713 // hierarchy-walking expensive.
1714 E = E->IgnoreParenCasts();
1715
1716 if (const BlockExpr *BE = dyn_cast<BlockExpr>(Val: E)) {
1717 const BlockDecl *Block = BE->getBlockDecl();
1718 for (const auto &I : Block->captures()) {
1719 if (I.getVariable() == &Var)
1720 return true;
1721 }
1722
1723 // No need to walk into the subexpressions.
1724 return false;
1725 }
1726
1727 if (const StmtExpr *SE = dyn_cast<StmtExpr>(Val: E)) {
1728 const CompoundStmt *CS = SE->getSubStmt();
1729 for (const auto *BI : CS->body())
1730 if (const auto *BIE = dyn_cast<Expr>(Val: BI)) {
1731 if (isCapturedBy(Var, E: BIE))
1732 return true;
1733 }
1734 else if (const auto *DS = dyn_cast<DeclStmt>(Val: BI)) {
1735 // special case declarations
1736 for (const auto *I : DS->decls()) {
1737 if (const auto *VD = dyn_cast<VarDecl>(Val: (I))) {
1738 const Expr *Init = VD->getInit();
1739 if (Init && isCapturedBy(Var, E: Init))
1740 return true;
1741 }
1742 }
1743 }
1744 else
1745 // FIXME. Make safe assumption assuming arbitrary statements cause capturing.
1746 // Later, provide code to poke into statements for capture analysis.
1747 return true;
1748 return false;
1749 }
1750
1751 for (const Stmt *SubStmt : E->children())
1752 if (isCapturedBy(Var, S: SubStmt))
1753 return true;
1754
1755 return false;
1756}
1757
1758/// Determine whether the given initializer is trivial in the sense
1759/// that it requires no code to be generated.
1760bool CodeGenFunction::isTrivialInitializer(const Expr *Init) {
1761 if (!Init)
1762 return true;
1763
1764 if (const CXXConstructExpr *Construct = dyn_cast<CXXConstructExpr>(Val: Init))
1765 if (CXXConstructorDecl *Constructor = Construct->getConstructor())
1766 if (Constructor->isTrivial() &&
1767 Constructor->isDefaultConstructor() &&
1768 !Construct->requiresZeroInitialization())
1769 return true;
1770
1771 return false;
1772}
1773
1774void CodeGenFunction::emitZeroOrPatternForAutoVarInit(QualType type,
1775 const VarDecl &D,
1776 Address Loc) {
1777 auto trivialAutoVarInit = getContext().getLangOpts().getTrivialAutoVarInit();
1778 auto trivialAutoVarInitMaxSize =
1779 getContext().getLangOpts().TrivialAutoVarInitMaxSize;
1780 CharUnits Size = getContext().getTypeSizeInChars(T: type);
1781 bool isVolatile = type.isVolatileQualified();
1782 if (!Size.isZero()) {
1783 // We skip auto-init variables by their alloc size. Take this as an example:
1784 // "struct Foo {int x; char buff[1024];}" Assume the max-size flag is 1023.
1785 // All Foo type variables will be skipped. Ideally, we only skip the buff
1786 // array and still auto-init X in this example.
1787 // TODO: Improve the size filtering to by member size.
1788 auto allocSize = CGM.getDataLayout().getTypeAllocSize(Ty: Loc.getElementType());
1789 switch (trivialAutoVarInit) {
1790 case LangOptions::TrivialAutoVarInitKind::Uninitialized:
1791 llvm_unreachable("Uninitialized handled by caller");
1792 case LangOptions::TrivialAutoVarInitKind::Zero:
1793 if (CGM.stopAutoInit())
1794 return;
1795 if (trivialAutoVarInitMaxSize > 0 &&
1796 allocSize > trivialAutoVarInitMaxSize)
1797 return;
1798 emitStoresForZeroInit(CGM, D, Loc, isVolatile, Builder);
1799 break;
1800 case LangOptions::TrivialAutoVarInitKind::Pattern:
1801 if (CGM.stopAutoInit())
1802 return;
1803 if (trivialAutoVarInitMaxSize > 0 &&
1804 allocSize > trivialAutoVarInitMaxSize)
1805 return;
1806 emitStoresForPatternInit(CGM, D, Loc, isVolatile, Builder);
1807 break;
1808 }
1809 return;
1810 }
1811
1812 // VLAs look zero-sized to getTypeInfo. We can't emit constant stores to
1813 // them, so emit a memcpy with the VLA size to initialize each element.
1814 // Technically zero-sized or negative-sized VLAs are undefined, and UBSan
1815 // will catch that code, but there exists code which generates zero-sized
1816 // VLAs. Be nice and initialize whatever they requested.
1817 const auto *VlaType = getContext().getAsVariableArrayType(T: type);
1818 if (!VlaType)
1819 return;
1820 auto VlaSize = getVLASize(vla: VlaType);
1821 auto SizeVal = VlaSize.NumElts;
1822 CharUnits EltSize = getContext().getTypeSizeInChars(T: VlaSize.Type);
1823 switch (trivialAutoVarInit) {
1824 case LangOptions::TrivialAutoVarInitKind::Uninitialized:
1825 llvm_unreachable("Uninitialized handled by caller");
1826
1827 case LangOptions::TrivialAutoVarInitKind::Zero: {
1828 if (CGM.stopAutoInit())
1829 return;
1830 if (!EltSize.isOne())
1831 SizeVal = Builder.CreateNUWMul(LHS: SizeVal, RHS: CGM.getSize(numChars: EltSize));
1832 auto *I = Builder.CreateMemSet(Dest: Loc, Value: llvm::ConstantInt::get(Ty: Int8Ty, V: 0),
1833 Size: SizeVal, IsVolatile: isVolatile);
1834 I->addAnnotationMetadata(Annotation: "auto-init");
1835 break;
1836 }
1837
1838 case LangOptions::TrivialAutoVarInitKind::Pattern: {
1839 if (CGM.stopAutoInit())
1840 return;
1841 llvm::Type *ElTy = Loc.getElementType();
1842 llvm::Constant *Constant = constWithPadding(
1843 CGM, isPattern: IsPattern::Yes, constant: initializationPatternFor(CGM, ElTy));
1844 CharUnits ConstantAlign = getContext().getTypeAlignInChars(T: VlaSize.Type);
1845 llvm::BasicBlock *SetupBB = createBasicBlock(name: "vla-setup.loop");
1846 llvm::BasicBlock *LoopBB = createBasicBlock(name: "vla-init.loop");
1847 llvm::BasicBlock *ContBB = createBasicBlock(name: "vla-init.cont");
1848 llvm::Value *IsZeroSizedVLA = Builder.CreateICmpEQ(
1849 LHS: SizeVal, RHS: llvm::ConstantInt::get(Ty: SizeVal->getType(), V: 0),
1850 Name: "vla.iszerosized");
1851 Builder.CreateCondBr(Cond: IsZeroSizedVLA, True: ContBB, False: SetupBB);
1852 EmitBlock(BB: SetupBB);
1853 if (!EltSize.isOne())
1854 SizeVal = Builder.CreateNUWMul(LHS: SizeVal, RHS: CGM.getSize(numChars: EltSize));
1855 llvm::Value *BaseSizeInChars =
1856 llvm::ConstantInt::get(Ty: IntPtrTy, V: EltSize.getQuantity());
1857 Address Begin = Loc.withElementType(ElemTy: Int8Ty);
1858 llvm::Value *End = Builder.CreateInBoundsGEP(Ty: Begin.getElementType(),
1859 Ptr: Begin.emitRawPointer(CGF&: *this),
1860 IdxList: SizeVal, Name: "vla.end");
1861 llvm::BasicBlock *OriginBB = Builder.GetInsertBlock();
1862 EmitBlock(BB: LoopBB);
1863 llvm::PHINode *Cur = Builder.CreatePHI(Ty: Begin.getType(), NumReservedValues: 2, Name: "vla.cur");
1864 Cur->addIncoming(V: Begin.emitRawPointer(CGF&: *this), BB: OriginBB);
1865 CharUnits CurAlign = Loc.getAlignment().alignmentOfArrayElement(elementSize: EltSize);
1866 auto *I =
1867 Builder.CreateMemCpy(Dest: Address(Cur, Int8Ty, CurAlign),
1868 Src: createUnnamedGlobalForMemcpyFrom(
1869 CGM, D, Builder, Constant, Align: ConstantAlign),
1870 Size: BaseSizeInChars, IsVolatile: isVolatile);
1871 I->addAnnotationMetadata(Annotation: "auto-init");
1872 llvm::Value *Next =
1873 Builder.CreateInBoundsGEP(Ty: Int8Ty, Ptr: Cur, IdxList: BaseSizeInChars, Name: "vla.next");
1874 llvm::Value *Done = Builder.CreateICmpEQ(LHS: Next, RHS: End, Name: "vla-init.isdone");
1875 Builder.CreateCondBr(Cond: Done, True: ContBB, False: LoopBB);
1876 Cur->addIncoming(V: Next, BB: LoopBB);
1877 EmitBlock(BB: ContBB);
1878 } break;
1879 }
1880}
1881
1882void CodeGenFunction::EmitAutoVarInit(const AutoVarEmission &emission) {
1883 assert(emission.Variable && "emission was not valid!");
1884
1885 // If this was emitted as a global constant, we're done.
1886 if (emission.wasEmittedAsGlobal()) return;
1887
1888 const VarDecl &D = *emission.Variable;
1889 auto DL = ApplyDebugLocation::CreateDefaultArtificial(CGF&: *this, TemporaryLocation: D.getLocation());
1890 QualType type = D.getType();
1891
1892 // If this local has an initializer, emit it now.
1893 const Expr *Init = D.getInit();
1894
1895 // If we are at an unreachable point, we don't need to emit the initializer
1896 // unless it contains a label.
1897 if (!HaveInsertPoint()) {
1898 if (!Init || !ContainsLabel(S: Init)) return;
1899 EnsureInsertPoint();
1900 }
1901
1902 // Initialize the structure of a __block variable.
1903 if (emission.IsEscapingByRef)
1904 emitByrefStructureInit(emission);
1905
1906 // Initialize the variable here if it doesn't have a initializer and it is a
1907 // C struct that is non-trivial to initialize or an array containing such a
1908 // struct.
1909 if (!Init &&
1910 type.isNonTrivialToPrimitiveDefaultInitialize() ==
1911 QualType::PDIK_Struct) {
1912 LValue Dst = MakeAddrLValue(Addr: emission.getAllocatedAddress(), T: type);
1913 if (emission.IsEscapingByRef)
1914 drillIntoBlockVariable(CGF&: *this, lvalue&: Dst, var: &D);
1915 defaultInitNonTrivialCStructVar(Dst);
1916 return;
1917 }
1918
1919 // Check whether this is a byref variable that's potentially
1920 // captured and moved by its own initializer. If so, we'll need to
1921 // emit the initializer first, then copy into the variable.
1922 bool capturedByInit =
1923 Init && emission.IsEscapingByRef && isCapturedBy(Var: D, E: Init);
1924
1925 bool locIsByrefHeader = !capturedByInit;
1926 const Address Loc =
1927 locIsByrefHeader ? emission.getObjectAddress(CGF&: *this) : emission.Addr;
1928
1929 // Note: constexpr already initializes everything correctly.
1930 LangOptions::TrivialAutoVarInitKind trivialAutoVarInit =
1931 (D.isConstexpr()
1932 ? LangOptions::TrivialAutoVarInitKind::Uninitialized
1933 : (D.getAttr<UninitializedAttr>()
1934 ? LangOptions::TrivialAutoVarInitKind::Uninitialized
1935 : getContext().getLangOpts().getTrivialAutoVarInit()));
1936
1937 auto initializeWhatIsTechnicallyUninitialized = [&](Address Loc) {
1938 if (trivialAutoVarInit ==
1939 LangOptions::TrivialAutoVarInitKind::Uninitialized)
1940 return;
1941
1942 // Only initialize a __block's storage: we always initialize the header.
1943 if (emission.IsEscapingByRef && !locIsByrefHeader)
1944 Loc = emitBlockByrefAddress(baseAddr: Loc, V: &D, /*follow=*/followForward: false);
1945
1946 return emitZeroOrPatternForAutoVarInit(type, D, Loc);
1947 };
1948
1949 if (isTrivialInitializer(Init))
1950 return initializeWhatIsTechnicallyUninitialized(Loc);
1951
1952 llvm::Constant *constant = nullptr;
1953 if (emission.IsConstantAggregate ||
1954 D.mightBeUsableInConstantExpressions(C: getContext())) {
1955 assert(!capturedByInit && "constant init contains a capturing block?");
1956 constant = ConstantEmitter(*this).tryEmitAbstractForInitializer(D);
1957 if (constant && !constant->isZeroValue() &&
1958 (trivialAutoVarInit !=
1959 LangOptions::TrivialAutoVarInitKind::Uninitialized)) {
1960 IsPattern isPattern =
1961 (trivialAutoVarInit == LangOptions::TrivialAutoVarInitKind::Pattern)
1962 ? IsPattern::Yes
1963 : IsPattern::No;
1964 // C guarantees that brace-init with fewer initializers than members in
1965 // the aggregate will initialize the rest of the aggregate as-if it were
1966 // static initialization. In turn static initialization guarantees that
1967 // padding is initialized to zero bits. We could instead pattern-init if D
1968 // has any ImplicitValueInitExpr, but that seems to be unintuitive
1969 // behavior.
1970 constant = constWithPadding(CGM, isPattern: IsPattern::No,
1971 constant: replaceUndef(CGM, isPattern, constant));
1972 }
1973
1974 if (D.getType()->isBitIntType() &&
1975 CGM.getTypes().typeRequiresSplitIntoByteArray(ASTTy: D.getType())) {
1976 // Constants for long _BitInt types are split into individual bytes.
1977 // Try to fold these back into an integer constant so it can be stored
1978 // properly.
1979 llvm::Type *LoadType = CGM.getTypes().convertTypeForLoadStore(
1980 T: D.getType(), LLVMTy: constant->getType());
1981 constant = llvm::ConstantFoldLoadFromConst(
1982 C: constant, Ty: LoadType, Offset: llvm::APInt::getZero(numBits: 32), DL: CGM.getDataLayout());
1983 }
1984 }
1985
1986 if (!constant) {
1987 if (trivialAutoVarInit !=
1988 LangOptions::TrivialAutoVarInitKind::Uninitialized) {
1989 // At this point, we know D has an Init expression, but isn't a constant.
1990 // - If D is not a scalar, auto-var-init conservatively (members may be
1991 // left uninitialized by constructor Init expressions for example).
1992 // - If D is a scalar, we only need to auto-var-init if there is a
1993 // self-reference. Otherwise, the Init expression should be sufficient.
1994 // It may be that the Init expression uses other uninitialized memory,
1995 // but auto-var-init here would not help, as auto-init would get
1996 // overwritten by Init.
1997 if (!D.getType()->isScalarType() || capturedByInit ||
1998 isAccessedBy(var: D, s: Init)) {
1999 initializeWhatIsTechnicallyUninitialized(Loc);
2000 }
2001 }
2002 LValue lv = MakeAddrLValue(Addr: Loc, T: type);
2003 lv.setNonGC(true);
2004 return EmitExprAsInit(init: Init, D: &D, lvalue: lv, capturedByInit);
2005 }
2006
2007 if (!emission.IsConstantAggregate) {
2008 // For simple scalar/complex initialization, store the value directly.
2009 LValue lv = MakeAddrLValue(Addr: Loc, T: type);
2010 lv.setNonGC(true);
2011 return EmitStoreThroughLValue(Src: RValue::get(V: constant), Dst: lv, isInit: true);
2012 }
2013
2014 emitStoresForConstant(CGM, D, Loc: Loc.withElementType(ElemTy: CGM.Int8Ty),
2015 isVolatile: type.isVolatileQualified(), Builder, constant,
2016 /*IsAutoInit=*/false);
2017}
2018
2019/// Emit an expression as an initializer for an object (variable, field, etc.)
2020/// at the given location. The expression is not necessarily the normal
2021/// initializer for the object, and the address is not necessarily
2022/// its normal location.
2023///
2024/// \param init the initializing expression
2025/// \param D the object to act as if we're initializing
2026/// \param lvalue the lvalue to initialize
2027/// \param capturedByInit true if \p D is a __block variable
2028/// whose address is potentially changed by the initializer
2029void CodeGenFunction::EmitExprAsInit(const Expr *init, const ValueDecl *D,
2030 LValue lvalue, bool capturedByInit) {
2031 QualType type = D->getType();
2032
2033 if (type->isReferenceType()) {
2034 RValue rvalue = EmitReferenceBindingToExpr(E: init);
2035 if (capturedByInit)
2036 drillIntoBlockVariable(CGF&: *this, lvalue, var: cast<VarDecl>(Val: D));
2037 EmitStoreThroughLValue(Src: rvalue, Dst: lvalue, isInit: true);
2038 return;
2039 }
2040 switch (getEvaluationKind(T: type)) {
2041 case TEK_Scalar:
2042 EmitScalarInit(init, D, lvalue, capturedByInit);
2043 return;
2044 case TEK_Complex: {
2045 ComplexPairTy complex = EmitComplexExpr(E: init);
2046 if (capturedByInit)
2047 drillIntoBlockVariable(CGF&: *this, lvalue, var: cast<VarDecl>(Val: D));
2048 EmitStoreOfComplex(V: complex, dest: lvalue, /*init*/ isInit: true);
2049 return;
2050 }
2051 case TEK_Aggregate:
2052 if (type->isAtomicType()) {
2053 EmitAtomicInit(E: const_cast<Expr*>(init), lvalue);
2054 } else {
2055 AggValueSlot::Overlap_t Overlap = AggValueSlot::MayOverlap;
2056 if (isa<VarDecl>(Val: D))
2057 Overlap = AggValueSlot::DoesNotOverlap;
2058 else if (auto *FD = dyn_cast<FieldDecl>(Val: D))
2059 Overlap = getOverlapForFieldInit(FD);
2060 // TODO: how can we delay here if D is captured by its initializer?
2061 EmitAggExpr(E: init,
2062 AS: AggValueSlot::forLValue(LV: lvalue, isDestructed: AggValueSlot::IsDestructed,
2063 needsGC: AggValueSlot::DoesNotNeedGCBarriers,
2064 isAliased: AggValueSlot::IsNotAliased, mayOverlap: Overlap));
2065 }
2066 return;
2067 }
2068 llvm_unreachable("bad evaluation kind");
2069}
2070
2071/// Enter a destroy cleanup for the given local variable.
2072void CodeGenFunction::emitAutoVarTypeCleanup(
2073 const CodeGenFunction::AutoVarEmission &emission,
2074 QualType::DestructionKind dtorKind) {
2075 assert(dtorKind != QualType::DK_none);
2076
2077 // Note that for __block variables, we want to destroy the
2078 // original stack object, not the possibly forwarded object.
2079 Address addr = emission.getObjectAddress(CGF&: *this);
2080
2081 const VarDecl *var = emission.Variable;
2082 QualType type = var->getType();
2083
2084 CleanupKind cleanupKind = NormalAndEHCleanup;
2085 CodeGenFunction::Destroyer *destroyer = nullptr;
2086
2087 switch (dtorKind) {
2088 case QualType::DK_none:
2089 llvm_unreachable("no cleanup for trivially-destructible variable");
2090
2091 case QualType::DK_cxx_destructor:
2092 // If there's an NRVO flag on the emission, we need a different
2093 // cleanup.
2094 if (emission.NRVOFlag) {
2095 assert(!type->isArrayType());
2096 CXXDestructorDecl *dtor = type->getAsCXXRecordDecl()->getDestructor();
2097 EHStack.pushCleanup<DestroyNRVOVariableCXX>(Kind: cleanupKind, A: addr, A: type, A: dtor,
2098 A: emission.NRVOFlag);
2099 return;
2100 }
2101 break;
2102
2103 case QualType::DK_objc_strong_lifetime:
2104 // Suppress cleanups for pseudo-strong variables.
2105 if (var->isARCPseudoStrong()) return;
2106
2107 // Otherwise, consider whether to use an EH cleanup or not.
2108 cleanupKind = getARCCleanupKind();
2109
2110 // Use the imprecise destroyer by default.
2111 if (!var->hasAttr<ObjCPreciseLifetimeAttr>())
2112 destroyer = CodeGenFunction::destroyARCStrongImprecise;
2113 break;
2114
2115 case QualType::DK_objc_weak_lifetime:
2116 break;
2117
2118 case QualType::DK_nontrivial_c_struct:
2119 destroyer = CodeGenFunction::destroyNonTrivialCStruct;
2120 if (emission.NRVOFlag) {
2121 assert(!type->isArrayType());
2122 EHStack.pushCleanup<DestroyNRVOVariableC>(Kind: cleanupKind, A: addr,
2123 A: emission.NRVOFlag, A: type);
2124 return;
2125 }
2126 break;
2127 }
2128
2129 // If we haven't chosen a more specific destroyer, use the default.
2130 if (!destroyer) destroyer = getDestroyer(destructionKind: dtorKind);
2131
2132 // Use an EH cleanup in array destructors iff the destructor itself
2133 // is being pushed as an EH cleanup.
2134 bool useEHCleanup = (cleanupKind & EHCleanup);
2135 EHStack.pushCleanup<DestroyObject>(Kind: cleanupKind, A: addr, A: type, A: destroyer,
2136 A: useEHCleanup);
2137}
2138
2139void CodeGenFunction::EmitAutoVarCleanups(const AutoVarEmission &emission) {
2140 assert(emission.Variable && "emission was not valid!");
2141
2142 // If this was emitted as a global constant, we're done.
2143 if (emission.wasEmittedAsGlobal()) return;
2144
2145 // If we don't have an insertion point, we're done. Sema prevents
2146 // us from jumping into any of these scopes anyway.
2147 if (!HaveInsertPoint()) return;
2148
2149 const VarDecl &D = *emission.Variable;
2150
2151 // Check the type for a cleanup.
2152 if (QualType::DestructionKind dtorKind = D.needsDestruction(Ctx: getContext()))
2153 emitAutoVarTypeCleanup(emission, dtorKind);
2154
2155 // In GC mode, honor objc_precise_lifetime.
2156 if (getLangOpts().getGC() != LangOptions::NonGC &&
2157 D.hasAttr<ObjCPreciseLifetimeAttr>()) {
2158 EHStack.pushCleanup<ExtendGCLifetime>(Kind: NormalCleanup, A: &D);
2159 }
2160
2161 // Handle the cleanup attribute.
2162 if (const CleanupAttr *CA = D.getAttr<CleanupAttr>()) {
2163 const FunctionDecl *FD = CA->getFunctionDecl();
2164
2165 llvm::Constant *F = CGM.GetAddrOfFunction(GD: FD);
2166 assert(F && "Could not find function!");
2167
2168 const CGFunctionInfo &Info = CGM.getTypes().arrangeFunctionDeclaration(FD);
2169 EHStack.pushCleanup<CallCleanupFunction>(Kind: NormalAndEHCleanup, A: F, A: &Info, A: &D);
2170 }
2171
2172 // If this is a block variable, call _Block_object_destroy
2173 // (on the unforwarded address). Don't enter this cleanup if we're in pure-GC
2174 // mode.
2175 if (emission.IsEscapingByRef &&
2176 CGM.getLangOpts().getGC() != LangOptions::GCOnly) {
2177 BlockFieldFlags Flags = BLOCK_FIELD_IS_BYREF;
2178 if (emission.Variable->getType().isObjCGCWeak())
2179 Flags |= BLOCK_FIELD_IS_WEAK;
2180 enterByrefCleanup(Kind: NormalAndEHCleanup, Addr: emission.Addr, Flags,
2181 /*LoadBlockVarAddr*/ false,
2182 CanThrow: cxxDestructorCanThrow(T: emission.Variable->getType()));
2183 }
2184}
2185
2186CodeGenFunction::Destroyer *
2187CodeGenFunction::getDestroyer(QualType::DestructionKind kind) {
2188 switch (kind) {
2189 case QualType::DK_none: llvm_unreachable("no destroyer for trivial dtor");
2190 case QualType::DK_cxx_destructor:
2191 return destroyCXXObject;
2192 case QualType::DK_objc_strong_lifetime:
2193 return destroyARCStrongPrecise;
2194 case QualType::DK_objc_weak_lifetime:
2195 return destroyARCWeak;
2196 case QualType::DK_nontrivial_c_struct:
2197 return destroyNonTrivialCStruct;
2198 }
2199 llvm_unreachable("Unknown DestructionKind");
2200}
2201
2202/// pushEHDestroy - Push the standard destructor for the given type as
2203/// an EH-only cleanup.
2204void CodeGenFunction::pushEHDestroy(QualType::DestructionKind dtorKind,
2205 Address addr, QualType type) {
2206 assert(dtorKind && "cannot push destructor for trivial type");
2207 assert(needsEHCleanup(dtorKind));
2208
2209 pushDestroy(kind: EHCleanup, addr, type, destroyer: getDestroyer(kind: dtorKind), useEHCleanupForArray: true);
2210}
2211
2212/// pushDestroy - Push the standard destructor for the given type as
2213/// at least a normal cleanup.
2214void CodeGenFunction::pushDestroy(QualType::DestructionKind dtorKind,
2215 Address addr, QualType type) {
2216 assert(dtorKind && "cannot push destructor for trivial type");
2217
2218 CleanupKind cleanupKind = getCleanupKind(kind: dtorKind);
2219 pushDestroy(kind: cleanupKind, addr, type, destroyer: getDestroyer(kind: dtorKind),
2220 useEHCleanupForArray: cleanupKind & EHCleanup);
2221}
2222
2223void CodeGenFunction::pushDestroy(CleanupKind cleanupKind, Address addr,
2224 QualType type, Destroyer *destroyer,
2225 bool useEHCleanupForArray) {
2226 pushFullExprCleanup<DestroyObject>(kind: cleanupKind, A: addr, A: type,
2227 A: destroyer, A: useEHCleanupForArray);
2228}
2229
2230// Pushes a destroy and defers its deactivation until its
2231// CleanupDeactivationScope is exited.
2232void CodeGenFunction::pushDestroyAndDeferDeactivation(
2233 QualType::DestructionKind dtorKind, Address addr, QualType type) {
2234 assert(dtorKind && "cannot push destructor for trivial type");
2235
2236 CleanupKind cleanupKind = getCleanupKind(kind: dtorKind);
2237 pushDestroyAndDeferDeactivation(
2238 cleanupKind, addr, type, destroyer: getDestroyer(kind: dtorKind), useEHCleanupForArray: cleanupKind & EHCleanup);
2239}
2240
2241void CodeGenFunction::pushDestroyAndDeferDeactivation(
2242 CleanupKind cleanupKind, Address addr, QualType type, Destroyer *destroyer,
2243 bool useEHCleanupForArray) {
2244 llvm::Instruction *DominatingIP =
2245 Builder.CreateFlagLoad(Addr: llvm::Constant::getNullValue(Ty: Int8PtrTy));
2246 pushDestroy(cleanupKind, addr, type, destroyer, useEHCleanupForArray);
2247 DeferredDeactivationCleanupStack.push_back(
2248 Elt: {.Cleanup: EHStack.stable_begin(), .DominatingIP: DominatingIP});
2249}
2250
2251void CodeGenFunction::pushStackRestore(CleanupKind Kind, Address SPMem) {
2252 EHStack.pushCleanup<CallStackRestore>(Kind, A: SPMem);
2253}
2254
2255void CodeGenFunction::pushKmpcAllocFree(
2256 CleanupKind Kind, std::pair<llvm::Value *, llvm::Value *> AddrSizePair) {
2257 EHStack.pushCleanup<KmpcAllocFree>(Kind, A: AddrSizePair);
2258}
2259
2260void CodeGenFunction::pushLifetimeExtendedDestroy(CleanupKind cleanupKind,
2261 Address addr, QualType type,
2262 Destroyer *destroyer,
2263 bool useEHCleanupForArray) {
2264 // If we're not in a conditional branch, we don't need to bother generating a
2265 // conditional cleanup.
2266 if (!isInConditionalBranch()) {
2267 // FIXME: When popping normal cleanups, we need to keep this EH cleanup
2268 // around in case a temporary's destructor throws an exception.
2269
2270 // Add the cleanup to the EHStack. After the full-expr, this would be
2271 // deactivated before being popped from the stack.
2272 pushDestroyAndDeferDeactivation(cleanupKind, addr, type, destroyer,
2273 useEHCleanupForArray);
2274
2275 // Since this is lifetime-extended, push it once again to the EHStack after
2276 // the full expression.
2277 return pushCleanupAfterFullExprWithActiveFlag<DestroyObject>(
2278 Kind: cleanupKind, ActiveFlag: Address::invalid(), A: addr, A: type, A: destroyer,
2279 A: useEHCleanupForArray);
2280 }
2281
2282 // Otherwise, we should only destroy the object if it's been initialized.
2283
2284 using ConditionalCleanupType =
2285 EHScopeStack::ConditionalCleanup<DestroyObject, Address, QualType,
2286 Destroyer *, bool>;
2287 DominatingValue<Address>::saved_type SavedAddr = saveValueInCond(value: addr);
2288
2289 // Remember to emit cleanup if we branch-out before end of full-expression
2290 // (eg: through stmt-expr or coro suspensions).
2291 AllocaTrackerRAII DeactivationAllocas(*this);
2292 Address ActiveFlagForDeactivation = createCleanupActiveFlag();
2293
2294 pushCleanupAndDeferDeactivation<ConditionalCleanupType>(
2295 Kind: cleanupKind, A: SavedAddr, A: type, A: destroyer, A: useEHCleanupForArray);
2296 initFullExprCleanupWithFlag(ActiveFlag: ActiveFlagForDeactivation);
2297 EHCleanupScope &cleanup = cast<EHCleanupScope>(Val&: *EHStack.begin());
2298 // Erase the active flag if the cleanup was not emitted.
2299 cleanup.AddAuxAllocas(Allocas: std::move(DeactivationAllocas).Take());
2300
2301 // Since this is lifetime-extended, push it once again to the EHStack after
2302 // the full expression.
2303 // The previous active flag would always be 'false' due to forced deferred
2304 // deactivation. Use a separate flag for lifetime-extension to correctly
2305 // remember if this branch was taken and the object was initialized.
2306 Address ActiveFlagForLifetimeExt = createCleanupActiveFlag();
2307 pushCleanupAfterFullExprWithActiveFlag<ConditionalCleanupType>(
2308 Kind: cleanupKind, ActiveFlag: ActiveFlagForLifetimeExt, A: SavedAddr, A: type, A: destroyer,
2309 A: useEHCleanupForArray);
2310}
2311
2312/// emitDestroy - Immediately perform the destruction of the given
2313/// object.
2314///
2315/// \param addr - the address of the object; a type*
2316/// \param type - the type of the object; if an array type, all
2317/// objects are destroyed in reverse order
2318/// \param destroyer - the function to call to destroy individual
2319/// elements
2320/// \param useEHCleanupForArray - whether an EH cleanup should be
2321/// used when destroying array elements, in case one of the
2322/// destructions throws an exception
2323void CodeGenFunction::emitDestroy(Address addr, QualType type,
2324 Destroyer *destroyer,
2325 bool useEHCleanupForArray) {
2326 const ArrayType *arrayType = getContext().getAsArrayType(T: type);
2327 if (!arrayType)
2328 return destroyer(*this, addr, type);
2329
2330 llvm::Value *length = emitArrayLength(arrayType, baseType&: type, addr);
2331
2332 CharUnits elementAlign =
2333 addr.getAlignment()
2334 .alignmentOfArrayElement(elementSize: getContext().getTypeSizeInChars(T: type));
2335
2336 // Normally we have to check whether the array is zero-length.
2337 bool checkZeroLength = true;
2338
2339 // But if the array length is constant, we can suppress that.
2340 if (llvm::ConstantInt *constLength = dyn_cast<llvm::ConstantInt>(Val: length)) {
2341 // ...and if it's constant zero, we can just skip the entire thing.
2342 if (constLength->isZero()) return;
2343 checkZeroLength = false;
2344 }
2345
2346 llvm::Value *begin = addr.emitRawPointer(CGF&: *this);
2347 llvm::Value *end =
2348 Builder.CreateInBoundsGEP(Ty: addr.getElementType(), Ptr: begin, IdxList: length);
2349 emitArrayDestroy(begin, end, elementType: type, elementAlign, destroyer,
2350 checkZeroLength, useEHCleanup: useEHCleanupForArray);
2351}
2352
2353/// emitArrayDestroy - Destroys all the elements of the given array,
2354/// beginning from last to first. The array cannot be zero-length.
2355///
2356/// \param begin - a type* denoting the first element of the array
2357/// \param end - a type* denoting one past the end of the array
2358/// \param elementType - the element type of the array
2359/// \param destroyer - the function to call to destroy elements
2360/// \param useEHCleanup - whether to push an EH cleanup to destroy
2361/// the remaining elements in case the destruction of a single
2362/// element throws
2363void CodeGenFunction::emitArrayDestroy(llvm::Value *begin,
2364 llvm::Value *end,
2365 QualType elementType,
2366 CharUnits elementAlign,
2367 Destroyer *destroyer,
2368 bool checkZeroLength,
2369 bool useEHCleanup) {
2370 assert(!elementType->isArrayType());
2371
2372 // The basic structure here is a do-while loop, because we don't
2373 // need to check for the zero-element case.
2374 llvm::BasicBlock *bodyBB = createBasicBlock(name: "arraydestroy.body");
2375 llvm::BasicBlock *doneBB = createBasicBlock(name: "arraydestroy.done");
2376
2377 if (checkZeroLength) {
2378 llvm::Value *isEmpty = Builder.CreateICmpEQ(LHS: begin, RHS: end,
2379 Name: "arraydestroy.isempty");
2380 Builder.CreateCondBr(Cond: isEmpty, True: doneBB, False: bodyBB);
2381 }
2382
2383 // Enter the loop body, making that address the current address.
2384 llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
2385 EmitBlock(BB: bodyBB);
2386 llvm::PHINode *elementPast =
2387 Builder.CreatePHI(Ty: begin->getType(), NumReservedValues: 2, Name: "arraydestroy.elementPast");
2388 elementPast->addIncoming(V: end, BB: entryBB);
2389
2390 // Shift the address back by one element.
2391 llvm::Value *negativeOne = llvm::ConstantInt::get(Ty: SizeTy, V: -1, IsSigned: true);
2392 llvm::Type *llvmElementType = ConvertTypeForMem(T: elementType);
2393 llvm::Value *element = Builder.CreateInBoundsGEP(
2394 Ty: llvmElementType, Ptr: elementPast, IdxList: negativeOne, Name: "arraydestroy.element");
2395
2396 if (useEHCleanup)
2397 pushRegularPartialArrayCleanup(arrayBegin: begin, arrayEnd: element, elementType, elementAlignment: elementAlign,
2398 destroyer);
2399
2400 // Perform the actual destruction there.
2401 destroyer(*this, Address(element, llvmElementType, elementAlign),
2402 elementType);
2403
2404 if (useEHCleanup)
2405 PopCleanupBlock();
2406
2407 // Check whether we've reached the end.
2408 llvm::Value *done = Builder.CreateICmpEQ(LHS: element, RHS: begin, Name: "arraydestroy.done");
2409 Builder.CreateCondBr(Cond: done, True: doneBB, False: bodyBB);
2410 elementPast->addIncoming(V: element, BB: Builder.GetInsertBlock());
2411
2412 // Done.
2413 EmitBlock(BB: doneBB);
2414}
2415
2416/// Perform partial array destruction as if in an EH cleanup. Unlike
2417/// emitArrayDestroy, the element type here may still be an array type.
2418static void emitPartialArrayDestroy(CodeGenFunction &CGF,
2419 llvm::Value *begin, llvm::Value *end,
2420 QualType type, CharUnits elementAlign,
2421 CodeGenFunction::Destroyer *destroyer) {
2422 llvm::Type *elemTy = CGF.ConvertTypeForMem(T: type);
2423
2424 // If the element type is itself an array, drill down.
2425 unsigned arrayDepth = 0;
2426 while (const ArrayType *arrayType = CGF.getContext().getAsArrayType(T: type)) {
2427 // VLAs don't require a GEP index to walk into.
2428 if (!isa<VariableArrayType>(Val: arrayType))
2429 arrayDepth++;
2430 type = arrayType->getElementType();
2431 }
2432
2433 if (arrayDepth) {
2434 llvm::Value *zero = llvm::ConstantInt::get(Ty: CGF.SizeTy, V: 0);
2435
2436 SmallVector<llvm::Value*,4> gepIndices(arrayDepth+1, zero);
2437 begin = CGF.Builder.CreateInBoundsGEP(
2438 Ty: elemTy, Ptr: begin, IdxList: gepIndices, Name: "pad.arraybegin");
2439 end = CGF.Builder.CreateInBoundsGEP(
2440 Ty: elemTy, Ptr: end, IdxList: gepIndices, Name: "pad.arrayend");
2441 }
2442
2443 // Destroy the array. We don't ever need an EH cleanup because we
2444 // assume that we're in an EH cleanup ourselves, so a throwing
2445 // destructor causes an immediate terminate.
2446 CGF.emitArrayDestroy(begin, end, elementType: type, elementAlign, destroyer,
2447 /*checkZeroLength*/ true, /*useEHCleanup*/ false);
2448}
2449
2450namespace {
2451 /// RegularPartialArrayDestroy - a cleanup which performs a partial
2452 /// array destroy where the end pointer is regularly determined and
2453 /// does not need to be loaded from a local.
2454 class RegularPartialArrayDestroy final : public EHScopeStack::Cleanup {
2455 llvm::Value *ArrayBegin;
2456 llvm::Value *ArrayEnd;
2457 QualType ElementType;
2458 CodeGenFunction::Destroyer *Destroyer;
2459 CharUnits ElementAlign;
2460 public:
2461 RegularPartialArrayDestroy(llvm::Value *arrayBegin, llvm::Value *arrayEnd,
2462 QualType elementType, CharUnits elementAlign,
2463 CodeGenFunction::Destroyer *destroyer)
2464 : ArrayBegin(arrayBegin), ArrayEnd(arrayEnd),
2465 ElementType(elementType), Destroyer(destroyer),
2466 ElementAlign(elementAlign) {}
2467
2468 void Emit(CodeGenFunction &CGF, Flags flags) override {
2469 emitPartialArrayDestroy(CGF, begin: ArrayBegin, end: ArrayEnd,
2470 type: ElementType, elementAlign: ElementAlign, destroyer: Destroyer);
2471 }
2472 };
2473
2474 /// IrregularPartialArrayDestroy - a cleanup which performs a
2475 /// partial array destroy where the end pointer is irregularly
2476 /// determined and must be loaded from a local.
2477 class IrregularPartialArrayDestroy final : public EHScopeStack::Cleanup {
2478 llvm::Value *ArrayBegin;
2479 Address ArrayEndPointer;
2480 QualType ElementType;
2481 CodeGenFunction::Destroyer *Destroyer;
2482 CharUnits ElementAlign;
2483 public:
2484 IrregularPartialArrayDestroy(llvm::Value *arrayBegin,
2485 Address arrayEndPointer,
2486 QualType elementType,
2487 CharUnits elementAlign,
2488 CodeGenFunction::Destroyer *destroyer)
2489 : ArrayBegin(arrayBegin), ArrayEndPointer(arrayEndPointer),
2490 ElementType(elementType), Destroyer(destroyer),
2491 ElementAlign(elementAlign) {}
2492
2493 void Emit(CodeGenFunction &CGF, Flags flags) override {
2494 llvm::Value *arrayEnd = CGF.Builder.CreateLoad(Addr: ArrayEndPointer);
2495 emitPartialArrayDestroy(CGF, begin: ArrayBegin, end: arrayEnd,
2496 type: ElementType, elementAlign: ElementAlign, destroyer: Destroyer);
2497 }
2498 };
2499} // end anonymous namespace
2500
2501/// pushIrregularPartialArrayCleanup - Push a NormalAndEHCleanup to
2502/// destroy already-constructed elements of the given array. The cleanup may be
2503/// popped with DeactivateCleanupBlock or PopCleanupBlock.
2504///
2505/// \param elementType - the immediate element type of the array;
2506/// possibly still an array type
2507void CodeGenFunction::pushIrregularPartialArrayCleanup(llvm::Value *arrayBegin,
2508 Address arrayEndPointer,
2509 QualType elementType,
2510 CharUnits elementAlign,
2511 Destroyer *destroyer) {
2512 pushFullExprCleanup<IrregularPartialArrayDestroy>(
2513 kind: NormalAndEHCleanup, A: arrayBegin, A: arrayEndPointer, A: elementType,
2514 A: elementAlign, A: destroyer);
2515}
2516
2517/// pushRegularPartialArrayCleanup - Push an EH cleanup to destroy
2518/// already-constructed elements of the given array. The cleanup
2519/// may be popped with DeactivateCleanupBlock or PopCleanupBlock.
2520///
2521/// \param elementType - the immediate element type of the array;
2522/// possibly still an array type
2523void CodeGenFunction::pushRegularPartialArrayCleanup(llvm::Value *arrayBegin,
2524 llvm::Value *arrayEnd,
2525 QualType elementType,
2526 CharUnits elementAlign,
2527 Destroyer *destroyer) {
2528 pushFullExprCleanup<RegularPartialArrayDestroy>(kind: EHCleanup,
2529 A: arrayBegin, A: arrayEnd,
2530 A: elementType, A: elementAlign,
2531 A: destroyer);
2532}
2533
2534/// Lazily declare the @llvm.lifetime.start intrinsic.
2535llvm::Function *CodeGenModule::getLLVMLifetimeStartFn() {
2536 if (LifetimeStartFn)
2537 return LifetimeStartFn;
2538 LifetimeStartFn = llvm::Intrinsic::getDeclaration(M: &getModule(),
2539 id: llvm::Intrinsic::lifetime_start, Tys: AllocaInt8PtrTy);
2540 return LifetimeStartFn;
2541}
2542
2543/// Lazily declare the @llvm.lifetime.end intrinsic.
2544llvm::Function *CodeGenModule::getLLVMLifetimeEndFn() {
2545 if (LifetimeEndFn)
2546 return LifetimeEndFn;
2547 LifetimeEndFn = llvm::Intrinsic::getDeclaration(M: &getModule(),
2548 id: llvm::Intrinsic::lifetime_end, Tys: AllocaInt8PtrTy);
2549 return LifetimeEndFn;
2550}
2551
2552namespace {
2553 /// A cleanup to perform a release of an object at the end of a
2554 /// function. This is used to balance out the incoming +1 of a
2555 /// ns_consumed argument when we can't reasonably do that just by
2556 /// not doing the initial retain for a __block argument.
2557 struct ConsumeARCParameter final : EHScopeStack::Cleanup {
2558 ConsumeARCParameter(llvm::Value *param,
2559 ARCPreciseLifetime_t precise)
2560 : Param(param), Precise(precise) {}
2561
2562 llvm::Value *Param;
2563 ARCPreciseLifetime_t Precise;
2564
2565 void Emit(CodeGenFunction &CGF, Flags flags) override {
2566 CGF.EmitARCRelease(value: Param, precise: Precise);
2567 }
2568 };
2569} // end anonymous namespace
2570
2571/// Emit an alloca (or GlobalValue depending on target)
2572/// for the specified parameter and set up LocalDeclMap.
2573void CodeGenFunction::EmitParmDecl(const VarDecl &D, ParamValue Arg,
2574 unsigned ArgNo) {
2575 bool NoDebugInfo = false;
2576 // FIXME: Why isn't ImplicitParamDecl a ParmVarDecl?
2577 assert((isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D)) &&
2578 "Invalid argument to EmitParmDecl");
2579
2580 // Set the name of the parameter's initial value to make IR easier to
2581 // read. Don't modify the names of globals.
2582 if (!isa<llvm::GlobalValue>(Val: Arg.getAnyValue()))
2583 Arg.getAnyValue()->setName(D.getName());
2584
2585 QualType Ty = D.getType();
2586
2587 // Use better IR generation for certain implicit parameters.
2588 if (auto IPD = dyn_cast<ImplicitParamDecl>(Val: &D)) {
2589 // The only implicit argument a block has is its literal.
2590 // This may be passed as an inalloca'ed value on Windows x86.
2591 if (BlockInfo) {
2592 llvm::Value *V = Arg.isIndirect()
2593 ? Builder.CreateLoad(Addr: Arg.getIndirectAddress())
2594 : Arg.getDirectValue();
2595 setBlockContextParameter(D: IPD, argNum: ArgNo, ptr: V);
2596 return;
2597 }
2598 // Suppressing debug info for ThreadPrivateVar parameters, else it hides
2599 // debug info of TLS variables.
2600 NoDebugInfo =
2601 (IPD->getParameterKind() == ImplicitParamKind::ThreadPrivateVar);
2602 }
2603
2604 Address DeclPtr = Address::invalid();
2605 RawAddress AllocaPtr = Address::invalid();
2606 bool DoStore = false;
2607 bool IsScalar = hasScalarEvaluationKind(T: Ty);
2608 bool UseIndirectDebugAddress = false;
2609
2610 // If we already have a pointer to the argument, reuse the input pointer.
2611 if (Arg.isIndirect()) {
2612 DeclPtr = Arg.getIndirectAddress();
2613 DeclPtr = DeclPtr.withElementType(ElemTy: ConvertTypeForMem(T: Ty));
2614 // Indirect argument is in alloca address space, which may be different
2615 // from the default address space.
2616 auto AllocaAS = CGM.getASTAllocaAddressSpace();
2617 auto *V = DeclPtr.emitRawPointer(CGF&: *this);
2618 AllocaPtr = RawAddress(V, DeclPtr.getElementType(), DeclPtr.getAlignment());
2619
2620 // For truly ABI indirect arguments -- those that are not `byval` -- store
2621 // the address of the argument on the stack to preserve debug information.
2622 ABIArgInfo ArgInfo = CurFnInfo->arguments()[ArgNo - 1].info;
2623 if (ArgInfo.isIndirect())
2624 UseIndirectDebugAddress = !ArgInfo.getIndirectByVal();
2625 if (UseIndirectDebugAddress) {
2626 auto PtrTy = getContext().getPointerType(T: Ty);
2627 AllocaPtr = CreateMemTemp(T: PtrTy, Align: getContext().getTypeAlignInChars(T: PtrTy),
2628 Name: D.getName() + ".indirect_addr");
2629 EmitStoreOfScalar(Value: V, Addr: AllocaPtr, /* Volatile */ false, Ty: PtrTy);
2630 }
2631
2632 auto SrcLangAS = getLangOpts().OpenCL ? LangAS::opencl_private : AllocaAS;
2633 auto DestLangAS =
2634 getLangOpts().OpenCL ? LangAS::opencl_private : LangAS::Default;
2635 if (SrcLangAS != DestLangAS) {
2636 assert(getContext().getTargetAddressSpace(SrcLangAS) ==
2637 CGM.getDataLayout().getAllocaAddrSpace());
2638 auto DestAS = getContext().getTargetAddressSpace(AS: DestLangAS);
2639 auto *T = llvm::PointerType::get(C&: getLLVMContext(), AddressSpace: DestAS);
2640 DeclPtr =
2641 DeclPtr.withPointer(NewPointer: getTargetHooks().performAddrSpaceCast(
2642 CGF&: *this, V, SrcAddr: SrcLangAS, DestAddr: DestLangAS, DestTy: T, IsNonNull: true),
2643 IsKnownNonNull: DeclPtr.isKnownNonNull());
2644 }
2645
2646 // Push a destructor cleanup for this parameter if the ABI requires it.
2647 // Don't push a cleanup in a thunk for a method that will also emit a
2648 // cleanup.
2649 if (Ty->isRecordType() && !CurFuncIsThunk &&
2650 Ty->castAs<RecordType>()->getDecl()->isParamDestroyedInCallee()) {
2651 if (QualType::DestructionKind DtorKind =
2652 D.needsDestruction(Ctx: getContext())) {
2653 assert((DtorKind == QualType::DK_cxx_destructor ||
2654 DtorKind == QualType::DK_nontrivial_c_struct) &&
2655 "unexpected destructor type");
2656 pushDestroy(dtorKind: DtorKind, addr: DeclPtr, type: Ty);
2657 CalleeDestructedParamCleanups[cast<ParmVarDecl>(Val: &D)] =
2658 EHStack.stable_begin();
2659 }
2660 }
2661 } else {
2662 // Check if the parameter address is controlled by OpenMP runtime.
2663 Address OpenMPLocalAddr =
2664 getLangOpts().OpenMP
2665 ? CGM.getOpenMPRuntime().getAddressOfLocalVariable(CGF&: *this, VD: &D)
2666 : Address::invalid();
2667 if (getLangOpts().OpenMP && OpenMPLocalAddr.isValid()) {
2668 DeclPtr = OpenMPLocalAddr;
2669 AllocaPtr = DeclPtr;
2670 } else {
2671 // Otherwise, create a temporary to hold the value.
2672 DeclPtr = CreateMemTemp(T: Ty, Align: getContext().getDeclAlign(D: &D),
2673 Name: D.getName() + ".addr", Alloca: &AllocaPtr);
2674 }
2675 DoStore = true;
2676 }
2677
2678 llvm::Value *ArgVal = (DoStore ? Arg.getDirectValue() : nullptr);
2679
2680 LValue lv = MakeAddrLValue(Addr: DeclPtr, T: Ty);
2681 if (IsScalar) {
2682 Qualifiers qs = Ty.getQualifiers();
2683 if (Qualifiers::ObjCLifetime lt = qs.getObjCLifetime()) {
2684 // We honor __attribute__((ns_consumed)) for types with lifetime.
2685 // For __strong, it's handled by just skipping the initial retain;
2686 // otherwise we have to balance out the initial +1 with an extra
2687 // cleanup to do the release at the end of the function.
2688 bool isConsumed = D.hasAttr<NSConsumedAttr>();
2689
2690 // If a parameter is pseudo-strong then we can omit the implicit retain.
2691 if (D.isARCPseudoStrong()) {
2692 assert(lt == Qualifiers::OCL_Strong &&
2693 "pseudo-strong variable isn't strong?");
2694 assert(qs.hasConst() && "pseudo-strong variable should be const!");
2695 lt = Qualifiers::OCL_ExplicitNone;
2696 }
2697
2698 // Load objects passed indirectly.
2699 if (Arg.isIndirect() && !ArgVal)
2700 ArgVal = Builder.CreateLoad(Addr: DeclPtr);
2701
2702 if (lt == Qualifiers::OCL_Strong) {
2703 if (!isConsumed) {
2704 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2705 // use objc_storeStrong(&dest, value) for retaining the
2706 // object. But first, store a null into 'dest' because
2707 // objc_storeStrong attempts to release its old value.
2708 llvm::Value *Null = CGM.EmitNullConstant(T: D.getType());
2709 EmitStoreOfScalar(value: Null, lvalue: lv, /* isInitialization */ isInit: true);
2710 EmitARCStoreStrongCall(addr: lv.getAddress(), value: ArgVal, resultIgnored: true);
2711 DoStore = false;
2712 }
2713 else
2714 // Don't use objc_retainBlock for block pointers, because we
2715 // don't want to Block_copy something just because we got it
2716 // as a parameter.
2717 ArgVal = EmitARCRetainNonBlock(value: ArgVal);
2718 }
2719 } else {
2720 // Push the cleanup for a consumed parameter.
2721 if (isConsumed) {
2722 ARCPreciseLifetime_t precise = (D.hasAttr<ObjCPreciseLifetimeAttr>()
2723 ? ARCPreciseLifetime : ARCImpreciseLifetime);
2724 EHStack.pushCleanup<ConsumeARCParameter>(Kind: getARCCleanupKind(), A: ArgVal,
2725 A: precise);
2726 }
2727
2728 if (lt == Qualifiers::OCL_Weak) {
2729 EmitARCInitWeak(addr: DeclPtr, value: ArgVal);
2730 DoStore = false; // The weak init is a store, no need to do two.
2731 }
2732 }
2733
2734 // Enter the cleanup scope.
2735 EmitAutoVarWithLifetime(CGF&: *this, var: D, addr: DeclPtr, lifetime: lt);
2736 }
2737 }
2738
2739 // Store the initial value into the alloca.
2740 if (DoStore)
2741 EmitStoreOfScalar(value: ArgVal, lvalue: lv, /* isInitialization */ isInit: true);
2742
2743 setAddrOfLocalVar(VD: &D, Addr: DeclPtr);
2744
2745 // Emit debug info for param declarations in non-thunk functions.
2746 if (CGDebugInfo *DI = getDebugInfo()) {
2747 if (CGM.getCodeGenOpts().hasReducedDebugInfo() && !CurFuncIsThunk &&
2748 !NoDebugInfo) {
2749 llvm::DILocalVariable *DILocalVar = DI->EmitDeclareOfArgVariable(
2750 Decl: &D, AI: AllocaPtr.getPointer(), ArgNo, Builder, UsePointerValue: UseIndirectDebugAddress);
2751 if (const auto *Var = dyn_cast_or_null<ParmVarDecl>(Val: &D))
2752 DI->getParamDbgMappings().insert(KV: {Var, DILocalVar});
2753 }
2754 }
2755
2756 if (D.hasAttr<AnnotateAttr>())
2757 EmitVarAnnotations(D: &D, V: DeclPtr.emitRawPointer(CGF&: *this));
2758
2759 // We can only check return value nullability if all arguments to the
2760 // function satisfy their nullability preconditions. This makes it necessary
2761 // to emit null checks for args in the function body itself.
2762 if (requiresReturnValueNullabilityCheck()) {
2763 auto Nullability = Ty->getNullability();
2764 if (Nullability && *Nullability == NullabilityKind::NonNull) {
2765 SanitizerScope SanScope(this);
2766 RetValNullabilityPrecondition =
2767 Builder.CreateAnd(LHS: RetValNullabilityPrecondition,
2768 RHS: Builder.CreateIsNotNull(Arg: Arg.getAnyValue()));
2769 }
2770 }
2771}
2772
2773void CodeGenModule::EmitOMPDeclareReduction(const OMPDeclareReductionDecl *D,
2774 CodeGenFunction *CGF) {
2775 if (!LangOpts.OpenMP || (!LangOpts.EmitAllDecls && !D->isUsed()))
2776 return;
2777 getOpenMPRuntime().emitUserDefinedReduction(CGF, D);
2778}
2779
2780void CodeGenModule::EmitOMPDeclareMapper(const OMPDeclareMapperDecl *D,
2781 CodeGenFunction *CGF) {
2782 if (!LangOpts.OpenMP || LangOpts.OpenMPSimd ||
2783 (!LangOpts.EmitAllDecls && !D->isUsed()))
2784 return;
2785 getOpenMPRuntime().emitUserDefinedMapper(D, CGF);
2786}
2787
2788void CodeGenModule::EmitOMPRequiresDecl(const OMPRequiresDecl *D) {
2789 getOpenMPRuntime().processRequiresDirective(D);
2790}
2791
2792void CodeGenModule::EmitOMPAllocateDecl(const OMPAllocateDecl *D) {
2793 for (const Expr *E : D->varlists()) {
2794 const auto *DE = cast<DeclRefExpr>(Val: E);
2795 const auto *VD = cast<VarDecl>(Val: DE->getDecl());
2796
2797 // Skip all but globals.
2798 if (!VD->hasGlobalStorage())
2799 continue;
2800
2801 // Check if the global has been materialized yet or not. If not, we are done
2802 // as any later generation will utilize the OMPAllocateDeclAttr. However, if
2803 // we already emitted the global we might have done so before the
2804 // OMPAllocateDeclAttr was attached, leading to the wrong address space
2805 // (potentially). While not pretty, common practise is to remove the old IR
2806 // global and generate a new one, so we do that here too. Uses are replaced
2807 // properly.
2808 StringRef MangledName = getMangledName(GD: VD);
2809 llvm::GlobalValue *Entry = GetGlobalValue(Ref: MangledName);
2810 if (!Entry)
2811 continue;
2812
2813 // We can also keep the existing global if the address space is what we
2814 // expect it to be, if not, it is replaced.
2815 QualType ASTTy = VD->getType();
2816 clang::LangAS GVAS = GetGlobalVarAddressSpace(D: VD);
2817 auto TargetAS = getContext().getTargetAddressSpace(AS: GVAS);
2818 if (Entry->getType()->getAddressSpace() == TargetAS)
2819 continue;
2820
2821 // Make a new global with the correct type / address space.
2822 llvm::Type *Ty = getTypes().ConvertTypeForMem(T: ASTTy);
2823 llvm::PointerType *PTy = llvm::PointerType::get(ElementType: Ty, AddressSpace: TargetAS);
2824
2825 // Replace all uses of the old global with a cast. Since we mutate the type
2826 // in place we neeed an intermediate that takes the spot of the old entry
2827 // until we can create the cast.
2828 llvm::GlobalVariable *DummyGV = new llvm::GlobalVariable(
2829 getModule(), Entry->getValueType(), false,
2830 llvm::GlobalValue::CommonLinkage, nullptr, "dummy", nullptr,
2831 llvm::GlobalVariable::NotThreadLocal, Entry->getAddressSpace());
2832 Entry->replaceAllUsesWith(V: DummyGV);
2833
2834 Entry->mutateType(Ty: PTy);
2835 llvm::Constant *NewPtrForOldDecl =
2836 llvm::ConstantExpr::getPointerBitCastOrAddrSpaceCast(
2837 C: Entry, Ty: DummyGV->getType());
2838
2839 // Now we have a casted version of the changed global, the dummy can be
2840 // replaced and deleted.
2841 DummyGV->replaceAllUsesWith(V: NewPtrForOldDecl);
2842 DummyGV->eraseFromParent();
2843 }
2844}
2845
2846std::optional<CharUnits>
2847CodeGenModule::getOMPAllocateAlignment(const VarDecl *VD) {
2848 if (const auto *AA = VD->getAttr<OMPAllocateDeclAttr>()) {
2849 if (Expr *Alignment = AA->getAlignment()) {
2850 unsigned UserAlign =
2851 Alignment->EvaluateKnownConstInt(Ctx: getContext()).getExtValue();
2852 CharUnits NaturalAlign =
2853 getNaturalTypeAlignment(T: VD->getType().getNonReferenceType());
2854
2855 // OpenMP5.1 pg 185 lines 7-10
2856 // Each item in the align modifier list must be aligned to the maximum
2857 // of the specified alignment and the type's natural alignment.
2858 return CharUnits::fromQuantity(
2859 Quantity: std::max<unsigned>(a: UserAlign, b: NaturalAlign.getQuantity()));
2860 }
2861 }
2862 return std::nullopt;
2863}
2864