1 //===--- CGDeclCXX.cpp - Emit LLVM Code for C++ declarations --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This contains code dealing with code generation of C++ declarations
12 //===----------------------------------------------------------------------===//
14 #include "CodeGenFunction.h"
16 #include "CGObjCRuntime.h"
17 #include "CGOpenMPRuntime.h"
18 #include "clang/Frontend/CodeGenOptions.h"
19 #include "llvm/ADT/StringExtras.h"
20 #include "llvm/IR/Intrinsics.h"
21 #include "llvm/IR/MDBuilder.h"
22 #include "llvm/Support/Path.h"
24 using namespace clang;
25 using namespace CodeGen;
27 static void EmitDeclInit(CodeGenFunction &CGF, const VarDecl &D,
28 ConstantAddress DeclPtr) {
29 assert(D.hasGlobalStorage() && "VarDecl must have global storage!");
30 assert(!D.getType()->isReferenceType() &&
31 "Should not call EmitDeclInit on a reference!");
33 QualType type = D.getType();
34 LValue lv = CGF.MakeAddrLValue(DeclPtr, type);
36 const Expr *Init = D.getInit();
37 switch (CGF.getEvaluationKind(type)) {
39 CodeGenModule &CGM = CGF.CGM;
40 if (lv.isObjCStrong())
41 CGM.getObjCRuntime().EmitObjCGlobalAssign(CGF, CGF.EmitScalarExpr(Init),
42 DeclPtr, D.getTLSKind());
43 else if (lv.isObjCWeak())
44 CGM.getObjCRuntime().EmitObjCWeakAssign(CGF, CGF.EmitScalarExpr(Init),
47 CGF.EmitScalarInit(Init, &D, lv, false);
51 CGF.EmitComplexExprIntoLValue(Init, lv, /*isInit*/ true);
54 CGF.EmitAggExpr(Init, AggValueSlot::forLValue(lv,AggValueSlot::IsDestructed,
55 AggValueSlot::DoesNotNeedGCBarriers,
56 AggValueSlot::IsNotAliased));
59 llvm_unreachable("bad evaluation kind");
62 /// Emit code to cause the destruction of the given variable with
63 /// static storage duration.
64 static void EmitDeclDestroy(CodeGenFunction &CGF, const VarDecl &D,
65 ConstantAddress addr) {
66 CodeGenModule &CGM = CGF.CGM;
68 // FIXME: __attribute__((cleanup)) ?
70 QualType type = D.getType();
71 QualType::DestructionKind dtorKind = type.isDestructedType();
74 case QualType::DK_none:
77 case QualType::DK_cxx_destructor:
80 case QualType::DK_objc_strong_lifetime:
81 case QualType::DK_objc_weak_lifetime:
82 // We don't care about releasing objects during process teardown.
83 assert(!D.getTLSKind() && "should have rejected this");
87 llvm::Constant *function;
88 llvm::Constant *argument;
90 // Special-case non-array C++ destructors, if they have the right signature.
91 // Under some ABIs, destructors return this instead of void, and cannot be
92 // passed directly to __cxa_atexit if the target does not allow this mismatch.
93 const CXXRecordDecl *Record = type->getAsCXXRecordDecl();
94 bool CanRegisterDestructor =
95 Record && (!CGM.getCXXABI().HasThisReturn(
96 GlobalDecl(Record->getDestructor(), Dtor_Complete)) ||
97 CGM.getCXXABI().canCallMismatchedFunctionType());
98 // If __cxa_atexit is disabled via a flag, a different helper function is
99 // generated elsewhere which uses atexit instead, and it takes the destructor
101 bool UsingExternalHelper = !CGM.getCodeGenOpts().CXAAtExit;
102 if (Record && (CanRegisterDestructor || UsingExternalHelper)) {
103 assert(!Record->hasTrivialDestructor());
104 CXXDestructorDecl *dtor = Record->getDestructor();
106 function = CGM.getAddrOfCXXStructor(dtor, StructorType::Complete);
107 argument = llvm::ConstantExpr::getBitCast(
108 addr.getPointer(), CGF.getTypes().ConvertType(type)->getPointerTo());
110 // Otherwise, the standard logic requires a helper function.
112 function = CodeGenFunction(CGM)
113 .generateDestroyHelper(addr, type, CGF.getDestroyer(dtorKind),
114 CGF.needsEHCleanup(dtorKind), &D);
115 argument = llvm::Constant::getNullValue(CGF.Int8PtrTy);
118 CGM.getCXXABI().registerGlobalDtor(CGF, D, function, argument);
121 /// Emit code to cause the variable at the given address to be considered as
122 /// constant from this point onwards.
123 static void EmitDeclInvariant(CodeGenFunction &CGF, const VarDecl &D,
124 llvm::Constant *Addr) {
125 // Do not emit the intrinsic if we're not optimizing.
126 if (!CGF.CGM.getCodeGenOpts().OptimizationLevel)
129 // Grab the llvm.invariant.start intrinsic.
130 llvm::Intrinsic::ID InvStartID = llvm::Intrinsic::invariant_start;
131 // Overloaded address space type.
132 llvm::Type *ObjectPtr[1] = {CGF.Int8PtrTy};
133 llvm::Constant *InvariantStart = CGF.CGM.getIntrinsic(InvStartID, ObjectPtr);
135 // Emit a call with the size in bytes of the object.
136 CharUnits WidthChars = CGF.getContext().getTypeSizeInChars(D.getType());
137 uint64_t Width = WidthChars.getQuantity();
138 llvm::Value *Args[2] = { llvm::ConstantInt::getSigned(CGF.Int64Ty, Width),
139 llvm::ConstantExpr::getBitCast(Addr, CGF.Int8PtrTy)};
140 CGF.Builder.CreateCall(InvariantStart, Args);
143 void CodeGenFunction::EmitCXXGlobalVarDeclInit(const VarDecl &D,
144 llvm::Constant *DeclPtr,
147 const Expr *Init = D.getInit();
148 QualType T = D.getType();
150 // The address space of a static local variable (DeclPtr) may be different
151 // from the address space of the "this" argument of the constructor. In that
152 // case, we need an addrspacecast before calling the constructor.
154 // struct StructWithCtor {
155 // __device__ StructWithCtor() {...}
157 // __device__ void foo() {
158 // __shared__ StructWithCtor s;
162 // For example, in the above CUDA code, the static local variable s has a
163 // "shared" address space qualifier, but the constructor of StructWithCtor
164 // expects "this" in the "generic" address space.
165 unsigned ExpectedAddrSpace = getContext().getTargetAddressSpace(T);
166 unsigned ActualAddrSpace = DeclPtr->getType()->getPointerAddressSpace();
167 if (ActualAddrSpace != ExpectedAddrSpace) {
168 llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(T);
169 llvm::PointerType *PTy = llvm::PointerType::get(LTy, ExpectedAddrSpace);
170 DeclPtr = llvm::ConstantExpr::getAddrSpaceCast(DeclPtr, PTy);
173 ConstantAddress DeclAddr(DeclPtr, getContext().getDeclAlign(&D));
175 if (!T->isReferenceType()) {
176 if (getLangOpts().OpenMP && D.hasAttr<OMPThreadPrivateDeclAttr>())
177 (void)CGM.getOpenMPRuntime().emitThreadPrivateVarDefinition(
178 &D, DeclAddr, D.getAttr<OMPThreadPrivateDeclAttr>()->getLocation(),
181 EmitDeclInit(*this, D, DeclAddr);
182 if (CGM.isTypeConstant(D.getType(), true))
183 EmitDeclInvariant(*this, D, DeclPtr);
185 EmitDeclDestroy(*this, D, DeclAddr);
189 assert(PerformInit && "cannot have constant initializer which needs "
190 "destruction for reference");
191 RValue RV = EmitReferenceBindingToExpr(Init);
192 EmitStoreOfScalar(RV.getScalarVal(), DeclAddr, false, T);
195 /// Create a stub function, suitable for being passed to atexit,
196 /// which passes the given address to the given destructor function.
197 llvm::Constant *CodeGenFunction::createAtExitStub(const VarDecl &VD,
198 llvm::Constant *dtor,
199 llvm::Constant *addr) {
200 // Get the destructor function type, void(*)(void).
201 llvm::FunctionType *ty = llvm::FunctionType::get(CGM.VoidTy, false);
202 SmallString<256> FnName;
204 llvm::raw_svector_ostream Out(FnName);
205 CGM.getCXXABI().getMangleContext().mangleDynamicAtExitDestructor(&VD, Out);
208 const CGFunctionInfo &FI = CGM.getTypes().arrangeNullaryFunction();
209 llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction(ty, FnName.str(),
213 CodeGenFunction CGF(CGM);
215 CGF.StartFunction(&VD, CGM.getContext().VoidTy, fn, FI, FunctionArgList());
217 llvm::CallInst *call = CGF.Builder.CreateCall(dtor, addr);
219 // Make sure the call and the callee agree on calling convention.
220 if (llvm::Function *dtorFn =
221 dyn_cast<llvm::Function>(dtor->stripPointerCasts()))
222 call->setCallingConv(dtorFn->getCallingConv());
224 CGF.FinishFunction();
229 /// Register a global destructor using the C atexit runtime function.
230 void CodeGenFunction::registerGlobalDtorWithAtExit(const VarDecl &VD,
231 llvm::Constant *dtor,
232 llvm::Constant *addr) {
233 // Create a function which calls the destructor.
234 llvm::Constant *dtorStub = createAtExitStub(VD, dtor, addr);
236 // extern "C" int atexit(void (*f)(void));
237 llvm::FunctionType *atexitTy =
238 llvm::FunctionType::get(IntTy, dtorStub->getType(), false);
240 llvm::Constant *atexit =
241 CGM.CreateRuntimeFunction(atexitTy, "atexit", llvm::AttributeList(),
243 if (llvm::Function *atexitFn = dyn_cast<llvm::Function>(atexit))
244 atexitFn->setDoesNotThrow();
246 EmitNounwindRuntimeCall(atexit, dtorStub);
249 void CodeGenFunction::EmitCXXGuardedInit(const VarDecl &D,
250 llvm::GlobalVariable *DeclPtr,
252 // If we've been asked to forbid guard variables, emit an error now.
253 // This diagnostic is hard-coded for Darwin's use case; we can find
254 // better phrasing if someone else needs it.
255 if (CGM.getCodeGenOpts().ForbidGuardVariables)
256 CGM.Error(D.getLocation(),
257 "this initialization requires a guard variable, which "
258 "the kernel does not support");
260 CGM.getCXXABI().EmitGuardedInit(*this, D, DeclPtr, PerformInit);
263 void CodeGenFunction::EmitCXXGuardedInitBranch(llvm::Value *NeedsInit,
264 llvm::BasicBlock *InitBlock,
265 llvm::BasicBlock *NoInitBlock,
268 assert((Kind == GuardKind::TlsGuard || D) && "no guarded variable");
270 // A guess at how many times we will enter the initialization of a
271 // variable, depending on the kind of variable.
272 static const uint64_t InitsPerTLSVar = 1024;
273 static const uint64_t InitsPerLocalVar = 1024 * 1024;
275 llvm::MDNode *Weights;
276 if (Kind == GuardKind::VariableGuard && !D->isLocalVarDecl()) {
277 // For non-local variables, don't apply any weighting for now. Due to our
278 // use of COMDATs, we expect there to be at most one initialization of the
279 // variable per DSO, but we have no way to know how many DSOs will try to
280 // initialize the variable.
284 // FIXME: For the TLS case, collect and use profiling information to
285 // determine a more accurate brach weight.
286 if (Kind == GuardKind::TlsGuard || D->getTLSKind())
287 NumInits = InitsPerTLSVar;
289 NumInits = InitsPerLocalVar;
291 // The probability of us entering the initializer is
292 // 1 / (total number of times we attempt to initialize the variable).
293 llvm::MDBuilder MDHelper(CGM.getLLVMContext());
294 Weights = MDHelper.createBranchWeights(1, NumInits - 1);
297 Builder.CreateCondBr(NeedsInit, InitBlock, NoInitBlock, Weights);
300 llvm::Function *CodeGenModule::CreateGlobalInitOrDestructFunction(
301 llvm::FunctionType *FTy, const Twine &Name, const CGFunctionInfo &FI,
302 SourceLocation Loc, bool TLS) {
304 llvm::Function::Create(FTy, llvm::GlobalValue::InternalLinkage,
306 if (!getLangOpts().AppleKext && !TLS) {
307 // Set the section if needed.
308 if (const char *Section = getTarget().getStaticInitSectionSpecifier())
309 Fn->setSection(Section);
312 SetInternalFunctionAttributes(nullptr, Fn, FI);
314 Fn->setCallingConv(getRuntimeCC());
316 if (!getLangOpts().Exceptions)
317 Fn->setDoesNotThrow();
319 if (getLangOpts().Sanitize.has(SanitizerKind::Address) &&
320 !isInSanitizerBlacklist(SanitizerKind::Address, Fn, Loc))
321 Fn->addFnAttr(llvm::Attribute::SanitizeAddress);
323 if (getLangOpts().Sanitize.has(SanitizerKind::KernelAddress) &&
324 !isInSanitizerBlacklist(SanitizerKind::KernelAddress, Fn, Loc))
325 Fn->addFnAttr(llvm::Attribute::SanitizeAddress);
327 if (getLangOpts().Sanitize.has(SanitizerKind::HWAddress) &&
328 !isInSanitizerBlacklist(SanitizerKind::HWAddress, Fn, Loc))
329 Fn->addFnAttr(llvm::Attribute::SanitizeHWAddress);
331 if (getLangOpts().Sanitize.has(SanitizerKind::Thread) &&
332 !isInSanitizerBlacklist(SanitizerKind::Thread, Fn, Loc))
333 Fn->addFnAttr(llvm::Attribute::SanitizeThread);
335 if (getLangOpts().Sanitize.has(SanitizerKind::Memory) &&
336 !isInSanitizerBlacklist(SanitizerKind::Memory, Fn, Loc))
337 Fn->addFnAttr(llvm::Attribute::SanitizeMemory);
339 if (getLangOpts().Sanitize.has(SanitizerKind::SafeStack) &&
340 !isInSanitizerBlacklist(SanitizerKind::SafeStack, Fn, Loc))
341 Fn->addFnAttr(llvm::Attribute::SafeStack);
346 /// Create a global pointer to a function that will initialize a global
347 /// variable. The user has requested that this pointer be emitted in a specific
349 void CodeGenModule::EmitPointerToInitFunc(const VarDecl *D,
350 llvm::GlobalVariable *GV,
351 llvm::Function *InitFunc,
353 llvm::GlobalVariable *PtrArray = new llvm::GlobalVariable(
354 TheModule, InitFunc->getType(), /*isConstant=*/true,
355 llvm::GlobalValue::PrivateLinkage, InitFunc, "__cxx_init_fn_ptr");
356 PtrArray->setSection(ISA->getSection());
357 addUsedGlobal(PtrArray);
359 // If the GV is already in a comdat group, then we have to join it.
360 if (llvm::Comdat *C = GV->getComdat())
361 PtrArray->setComdat(C);
365 CodeGenModule::EmitCXXGlobalVarDeclInitFunc(const VarDecl *D,
366 llvm::GlobalVariable *Addr,
369 // According to E.2.3.1 in CUDA-7.5 Programming guide: __device__,
370 // __constant__ and __shared__ variables defined in namespace scope,
371 // that are of class type, cannot have a non-empty constructor. All
372 // the checks have been done in Sema by now. Whatever initializers
373 // are allowed are empty and we just need to ignore them here.
374 if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice &&
375 (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() ||
376 D->hasAttr<CUDASharedAttr>()))
379 // Check if we've already initialized this decl.
380 auto I = DelayedCXXInitPosition.find(D);
381 if (I != DelayedCXXInitPosition.end() && I->second == ~0U)
384 llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
385 SmallString<256> FnName;
387 llvm::raw_svector_ostream Out(FnName);
388 getCXXABI().getMangleContext().mangleDynamicInitializer(D, Out);
391 // Create a variable initialization function.
393 CreateGlobalInitOrDestructFunction(FTy, FnName.str(),
394 getTypes().arrangeNullaryFunction(),
397 auto *ISA = D->getAttr<InitSegAttr>();
398 CodeGenFunction(*this).GenerateCXXGlobalVarDeclInitFunc(Fn, D, Addr,
401 llvm::GlobalVariable *COMDATKey =
402 supportsCOMDAT() && D->isExternallyVisible() ? Addr : nullptr;
404 if (D->getTLSKind()) {
405 // FIXME: Should we support init_priority for thread_local?
406 // FIXME: We only need to register one __cxa_thread_atexit function for the
408 CXXThreadLocalInits.push_back(Fn);
409 CXXThreadLocalInitVars.push_back(D);
410 } else if (PerformInit && ISA) {
411 EmitPointerToInitFunc(D, Addr, Fn, ISA);
412 } else if (auto *IPA = D->getAttr<InitPriorityAttr>()) {
413 OrderGlobalInits Key(IPA->getPriority(), PrioritizedCXXGlobalInits.size());
414 PrioritizedCXXGlobalInits.push_back(std::make_pair(Key, Fn));
415 } else if (isTemplateInstantiation(D->getTemplateSpecializationKind())) {
416 // C++ [basic.start.init]p2:
417 // Definitions of explicitly specialized class template static data
418 // members have ordered initialization. Other class template static data
419 // members (i.e., implicitly or explicitly instantiated specializations)
420 // have unordered initialization.
422 // As a consequence, we can put them into their own llvm.global_ctors entry.
424 // If the global is externally visible, put the initializer into a COMDAT
425 // group with the global being initialized. On most platforms, this is a
426 // minor startup time optimization. In the MS C++ ABI, there are no guard
427 // variables, so this COMDAT key is required for correctness.
428 AddGlobalCtor(Fn, 65535, COMDATKey);
429 } else if (D->hasAttr<SelectAnyAttr>()) {
430 // SelectAny globals will be comdat-folded. Put the initializer into a
431 // COMDAT group associated with the global, so the initializers get folded
433 AddGlobalCtor(Fn, 65535, COMDATKey);
435 I = DelayedCXXInitPosition.find(D); // Re-do lookup in case of re-hash.
436 if (I == DelayedCXXInitPosition.end()) {
437 CXXGlobalInits.push_back(Fn);
438 } else if (I->second != ~0U) {
439 assert(I->second < CXXGlobalInits.size() &&
440 CXXGlobalInits[I->second] == nullptr);
441 CXXGlobalInits[I->second] = Fn;
445 // Remember that we already emitted the initializer for this global.
446 DelayedCXXInitPosition[D] = ~0U;
449 void CodeGenModule::EmitCXXThreadLocalInitFunc() {
450 getCXXABI().EmitThreadLocalInitFuncs(
451 *this, CXXThreadLocals, CXXThreadLocalInits, CXXThreadLocalInitVars);
453 CXXThreadLocalInits.clear();
454 CXXThreadLocalInitVars.clear();
455 CXXThreadLocals.clear();
459 CodeGenModule::EmitCXXGlobalInitFunc() {
460 while (!CXXGlobalInits.empty() && !CXXGlobalInits.back())
461 CXXGlobalInits.pop_back();
463 if (CXXGlobalInits.empty() && PrioritizedCXXGlobalInits.empty())
466 llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
467 const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();
469 // Create our global initialization function.
470 if (!PrioritizedCXXGlobalInits.empty()) {
471 SmallVector<llvm::Function *, 8> LocalCXXGlobalInits;
472 llvm::array_pod_sort(PrioritizedCXXGlobalInits.begin(),
473 PrioritizedCXXGlobalInits.end());
474 // Iterate over "chunks" of ctors with same priority and emit each chunk
475 // into separate function. Note - everything is sorted first by priority,
476 // second - by lex order, so we emit ctor functions in proper order.
477 for (SmallVectorImpl<GlobalInitData >::iterator
478 I = PrioritizedCXXGlobalInits.begin(),
479 E = PrioritizedCXXGlobalInits.end(); I != E; ) {
480 SmallVectorImpl<GlobalInitData >::iterator
481 PrioE = std::upper_bound(I + 1, E, *I, GlobalInitPriorityCmp());
483 LocalCXXGlobalInits.clear();
484 unsigned Priority = I->first.priority;
485 // Compute the function suffix from priority. Prepend with zeroes to make
486 // sure the function names are also ordered as priorities.
487 std::string PrioritySuffix = llvm::utostr(Priority);
488 // Priority is always <= 65535 (enforced by sema).
489 PrioritySuffix = std::string(6-PrioritySuffix.size(), '0')+PrioritySuffix;
490 llvm::Function *Fn = CreateGlobalInitOrDestructFunction(
491 FTy, "_GLOBAL__I_" + PrioritySuffix, FI);
493 for (; I < PrioE; ++I)
494 LocalCXXGlobalInits.push_back(I->second);
496 CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, LocalCXXGlobalInits);
497 AddGlobalCtor(Fn, Priority);
499 PrioritizedCXXGlobalInits.clear();
502 // Include the filename in the symbol name. Including "sub_" matches gcc and
503 // makes sure these symbols appear lexicographically behind the symbols with
504 // priority emitted above.
505 SmallString<128> FileName = llvm::sys::path::filename(getModule().getName());
506 if (FileName.empty())
509 for (size_t i = 0; i < FileName.size(); ++i) {
510 // Replace everything that's not [a-zA-Z0-9._] with a _. This set happens
511 // to be the set of C preprocessing numbers.
512 if (!isPreprocessingNumberBody(FileName[i]))
516 llvm::Function *Fn = CreateGlobalInitOrDestructFunction(
517 FTy, llvm::Twine("_GLOBAL__sub_I_", FileName), FI);
519 CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, CXXGlobalInits);
522 CXXGlobalInits.clear();
525 void CodeGenModule::EmitCXXGlobalDtorFunc() {
526 if (CXXGlobalDtors.empty())
529 llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
531 // Create our global destructor function.
532 const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction();
534 CreateGlobalInitOrDestructFunction(FTy, "_GLOBAL__D_a", FI);
536 CodeGenFunction(*this).GenerateCXXGlobalDtorsFunc(Fn, CXXGlobalDtors);
540 /// Emit the code necessary to initialize the given global variable.
541 void CodeGenFunction::GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn,
543 llvm::GlobalVariable *Addr,
545 // Check if we need to emit debug info for variable initializer.
546 if (D->hasAttr<NoDebugAttr>())
547 DebugInfo = nullptr; // disable debug info indefinitely for this function
549 CurEHLocation = D->getLocStart();
551 StartFunction(GlobalDecl(D), getContext().VoidTy, Fn,
552 getTypes().arrangeNullaryFunction(),
553 FunctionArgList(), D->getLocation(),
554 D->getInit()->getExprLoc());
556 // Use guarded initialization if the global variable is weak. This
557 // occurs for, e.g., instantiated static data members and
558 // definitions explicitly marked weak.
559 if (Addr->hasWeakLinkage() || Addr->hasLinkOnceLinkage()) {
560 EmitCXXGuardedInit(*D, Addr, PerformInit);
562 EmitCXXGlobalVarDeclInit(*D, Addr, PerformInit);
569 CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn,
570 ArrayRef<llvm::Function *> Decls,
573 auto NL = ApplyDebugLocation::CreateEmpty(*this);
574 StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
575 getTypes().arrangeNullaryFunction(), FunctionArgList());
576 // Emit an artificial location for this function.
577 auto AL = ApplyDebugLocation::CreateArtificial(*this);
579 llvm::BasicBlock *ExitBlock = nullptr;
580 if (Guard.isValid()) {
581 // If we have a guard variable, check whether we've already performed
582 // these initializations. This happens for TLS initialization functions.
583 llvm::Value *GuardVal = Builder.CreateLoad(Guard);
584 llvm::Value *Uninit = Builder.CreateIsNull(GuardVal,
585 "guard.uninitialized");
586 llvm::BasicBlock *InitBlock = createBasicBlock("init");
587 ExitBlock = createBasicBlock("exit");
588 EmitCXXGuardedInitBranch(Uninit, InitBlock, ExitBlock,
589 GuardKind::TlsGuard, nullptr);
590 EmitBlock(InitBlock);
591 // Mark as initialized before initializing anything else. If the
592 // initializers use previously-initialized thread_local vars, that's
593 // probably supposed to be OK, but the standard doesn't say.
594 Builder.CreateStore(llvm::ConstantInt::get(GuardVal->getType(),1), Guard);
597 RunCleanupsScope Scope(*this);
599 // When building in Objective-C++ ARC mode, create an autorelease pool
600 // around the global initializers.
601 if (getLangOpts().ObjCAutoRefCount && getLangOpts().CPlusPlus) {
602 llvm::Value *token = EmitObjCAutoreleasePoolPush();
603 EmitObjCAutoreleasePoolCleanup(token);
606 for (unsigned i = 0, e = Decls.size(); i != e; ++i)
608 EmitRuntimeCall(Decls[i]);
610 Scope.ForceCleanup();
613 Builder.CreateBr(ExitBlock);
614 EmitBlock(ExitBlock);
621 void CodeGenFunction::GenerateCXXGlobalDtorsFunc(
623 const std::vector<std::pair<llvm::WeakTrackingVH, llvm::Constant *>>
626 auto NL = ApplyDebugLocation::CreateEmpty(*this);
627 StartFunction(GlobalDecl(), getContext().VoidTy, Fn,
628 getTypes().arrangeNullaryFunction(), FunctionArgList());
629 // Emit an artificial location for this function.
630 auto AL = ApplyDebugLocation::CreateArtificial(*this);
632 // Emit the dtors, in reverse order from construction.
633 for (unsigned i = 0, e = DtorsAndObjects.size(); i != e; ++i) {
634 llvm::Value *Callee = DtorsAndObjects[e - i - 1].first;
635 llvm::CallInst *CI = Builder.CreateCall(Callee,
636 DtorsAndObjects[e - i - 1].second);
637 // Make sure the call and the callee agree on calling convention.
638 if (llvm::Function *F = dyn_cast<llvm::Function>(Callee))
639 CI->setCallingConv(F->getCallingConv());
646 /// generateDestroyHelper - Generates a helper function which, when
647 /// invoked, destroys the given object. The address of the object
648 /// should be in global memory.
649 llvm::Function *CodeGenFunction::generateDestroyHelper(
650 Address addr, QualType type, Destroyer *destroyer,
651 bool useEHCleanupForArray, const VarDecl *VD) {
652 FunctionArgList args;
653 ImplicitParamDecl Dst(getContext(), getContext().VoidPtrTy,
654 ImplicitParamDecl::Other);
655 args.push_back(&Dst);
657 const CGFunctionInfo &FI =
658 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, args);
659 llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(FI);
660 llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction(
661 FTy, "__cxx_global_array_dtor", FI, VD->getLocation());
663 CurEHLocation = VD->getLocStart();
665 StartFunction(VD, getContext().VoidTy, fn, FI, args);
667 emitDestroy(addr, type, destroyer, useEHCleanupForArray);