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CGDeclCXX.cpp
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1 //===--- CGDeclCXX.cpp - Emit LLVM Code for C++ declarations --------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This contains code dealing with code generation of C++ declarations
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CodeGenFunction.h"
15 #include "CGCXXABI.h"
16 #include "CGObjCRuntime.h"
17 #include "CGOpenMPRuntime.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"
23 
24 using namespace clang;
25 using namespace CodeGen;
26 
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!");
32 
33  QualType type = D.getType();
34  LValue lv = CGF.MakeAddrLValue(DeclPtr, type);
35 
36  const Expr *Init = D.getInit();
37  switch (CGF.getEvaluationKind(type)) {
38  case TEK_Scalar: {
39  CodeGenModule &CGM = CGF.CGM;
40  if (lv.isObjCStrong())
42  DeclPtr, D.getTLSKind());
43  else if (lv.isObjCWeak())
45  DeclPtr);
46  else
47  CGF.EmitScalarInit(Init, &D, lv, false);
48  return;
49  }
50  case TEK_Complex:
51  CGF.EmitComplexExprIntoLValue(Init, lv, /*isInit*/ true);
52  return;
53  case TEK_Aggregate:
57  return;
58  }
59  llvm_unreachable("bad evaluation kind");
60 }
61 
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;
67 
68  // FIXME: __attribute__((cleanup)) ?
69 
70  QualType type = D.getType();
72 
73  switch (dtorKind) {
74  case QualType::DK_none:
75  return;
76 
78  break;
79 
82  // We don't care about releasing objects during process teardown.
83  assert(!D.getTLSKind() && "should have rejected this");
84  return;
85  }
86 
87  llvm::Constant *function;
88  llvm::Constant *argument;
89 
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)) ||
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
100  // directly.
101  bool UsingExternalHelper = !CGM.getCodeGenOpts().CXAAtExit;
102  if (Record && (CanRegisterDestructor || UsingExternalHelper)) {
103  assert(!Record->hasTrivialDestructor());
104  CXXDestructorDecl *dtor = Record->getDestructor();
105 
106  function = CGM.getAddrOfCXXStructor(dtor, StructorType::Complete);
107  argument = llvm::ConstantExpr::getBitCast(
108  addr.getPointer(), CGF.getTypes().ConvertType(type)->getPointerTo());
109 
110  // Otherwise, the standard logic requires a helper function.
111  } else {
112  function = CodeGenFunction(CGM)
113  .generateDestroyHelper(addr, type, CGF.getDestroyer(dtorKind),
114  CGF.needsEHCleanup(dtorKind), &D);
115  argument = llvm::Constant::getNullValue(CGF.Int8PtrTy);
116  }
117 
118  CGM.getCXXABI().registerGlobalDtor(CGF, D, function, argument);
119 }
120 
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)
127  return;
128 
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);
134 
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);
141 }
142 
144  llvm::Constant *DeclPtr,
145  bool PerformInit) {
146 
147  const Expr *Init = D.getInit();
148  QualType T = D.getType();
149 
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.
153  //
154  // struct StructWithCtor {
155  // __device__ StructWithCtor() {...}
156  // };
157  // __device__ void foo() {
158  // __shared__ StructWithCtor s;
159  // ...
160  // }
161  //
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) {
169  llvm::PointerType *PTy = llvm::PointerType::get(LTy, ExpectedAddrSpace);
170  DeclPtr = llvm::ConstantExpr::getAddrSpaceCast(DeclPtr, PTy);
171  }
172 
173  ConstantAddress DeclAddr(DeclPtr, getContext().getDeclAlign(&D));
174 
175  if (!T->isReferenceType()) {
176  if (getLangOpts().OpenMP && D.hasAttr<OMPThreadPrivateDeclAttr>())
177  (void)CGM.getOpenMPRuntime().emitThreadPrivateVarDefinition(
178  &D, DeclAddr, D.getAttr<OMPThreadPrivateDeclAttr>()->getLocation(),
179  PerformInit, this);
180  if (PerformInit)
181  EmitDeclInit(*this, D, DeclAddr);
182  if (CGM.isTypeConstant(D.getType(), true))
183  EmitDeclInvariant(*this, D, DeclPtr);
184  else
185  EmitDeclDestroy(*this, D, DeclAddr);
186  return;
187  }
188 
189  assert(PerformInit && "cannot have constant initializer which needs "
190  "destruction for reference");
192  EmitStoreOfScalar(RV.getScalarVal(), DeclAddr, false, T);
193 }
194 
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;
203  {
204  llvm::raw_svector_ostream Out(FnName);
206  }
207 
209  llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction(ty, FnName.str(),
210  FI,
211  VD.getLocation());
212 
213  CodeGenFunction CGF(CGM);
214 
215  CGF.StartFunction(&VD, CGM.getContext().VoidTy, fn, FI, FunctionArgList());
216 
217  llvm::CallInst *call = CGF.Builder.CreateCall(dtor, addr);
218 
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());
223 
224  CGF.FinishFunction();
225 
226  return fn;
227 }
228 
229 /// Register a global destructor using the C atexit runtime function.
231  llvm::Constant *dtor,
232  llvm::Constant *addr) {
233  // Create a function which calls the destructor.
234  llvm::Constant *dtorStub = createAtExitStub(VD, dtor, addr);
235 
236  // extern "C" int atexit(void (*f)(void));
237  llvm::FunctionType *atexitTy =
238  llvm::FunctionType::get(IntTy, dtorStub->getType(), false);
239 
240  llvm::Constant *atexit =
241  CGM.CreateRuntimeFunction(atexitTy, "atexit", llvm::AttributeList(),
242  /*Local=*/true);
243  if (llvm::Function *atexitFn = dyn_cast<llvm::Function>(atexit))
244  atexitFn->setDoesNotThrow();
245 
246  EmitNounwindRuntimeCall(atexit, dtorStub);
247 }
248 
250  llvm::GlobalVariable *DeclPtr,
251  bool PerformInit) {
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");
259 
260  CGM.getCXXABI().EmitGuardedInit(*this, D, DeclPtr, PerformInit);
261 }
262 
264  llvm::BasicBlock *InitBlock,
265  llvm::BasicBlock *NoInitBlock,
266  GuardKind Kind,
267  const VarDecl *D) {
268  assert((Kind == GuardKind::TlsGuard || D) && "no guarded variable");
269 
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;
274 
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.
281  Weights = nullptr;
282  } else {
283  uint64_t NumInits;
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;
288  else
289  NumInits = InitsPerLocalVar;
290 
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);
295  }
296 
297  Builder.CreateCondBr(NeedsInit, InitBlock, NoInitBlock, Weights);
298 }
299 
301  llvm::FunctionType *FTy, const Twine &Name, const CGFunctionInfo &FI,
302  SourceLocation Loc, bool TLS) {
303  llvm::Function *Fn =
305  Name, &getModule());
306  if (!getLangOpts().AppleKext && !TLS) {
307  // Set the section if needed.
308  if (const char *Section = getTarget().getStaticInitSectionSpecifier())
309  Fn->setSection(Section);
310  }
311 
312  SetInternalFunctionAttributes(nullptr, Fn, FI);
313 
314  Fn->setCallingConv(getRuntimeCC());
315 
316  if (!getLangOpts().Exceptions)
317  Fn->setDoesNotThrow();
318 
319  if (getLangOpts().Sanitize.has(SanitizerKind::Address) &&
320  !isInSanitizerBlacklist(SanitizerKind::Address, Fn, Loc))
321  Fn->addFnAttr(llvm::Attribute::SanitizeAddress);
322 
323  if (getLangOpts().Sanitize.has(SanitizerKind::KernelAddress) &&
324  !isInSanitizerBlacklist(SanitizerKind::KernelAddress, Fn, Loc))
325  Fn->addFnAttr(llvm::Attribute::SanitizeAddress);
326 
327  if (getLangOpts().Sanitize.has(SanitizerKind::HWAddress) &&
328  !isInSanitizerBlacklist(SanitizerKind::HWAddress, Fn, Loc))
329  Fn->addFnAttr(llvm::Attribute::SanitizeHWAddress);
330 
331  if (getLangOpts().Sanitize.has(SanitizerKind::Thread) &&
332  !isInSanitizerBlacklist(SanitizerKind::Thread, Fn, Loc))
333  Fn->addFnAttr(llvm::Attribute::SanitizeThread);
334 
335  if (getLangOpts().Sanitize.has(SanitizerKind::Memory) &&
336  !isInSanitizerBlacklist(SanitizerKind::Memory, Fn, Loc))
337  Fn->addFnAttr(llvm::Attribute::SanitizeMemory);
338 
339  if (getLangOpts().Sanitize.has(SanitizerKind::SafeStack) &&
340  !isInSanitizerBlacklist(SanitizerKind::SafeStack, Fn, Loc))
341  Fn->addFnAttr(llvm::Attribute::SafeStack);
342 
343  return Fn;
344 }
345 
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
348 /// section.
349 void CodeGenModule::EmitPointerToInitFunc(const VarDecl *D,
350  llvm::GlobalVariable *GV,
351  llvm::Function *InitFunc,
352  InitSegAttr *ISA) {
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);
358 
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);
362 }
363 
364 void
365 CodeGenModule::EmitCXXGlobalVarDeclInitFunc(const VarDecl *D,
366  llvm::GlobalVariable *Addr,
367  bool PerformInit) {
368 
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>()))
377  return;
378 
379  // Check if we've already initialized this decl.
380  auto I = DelayedCXXInitPosition.find(D);
381  if (I != DelayedCXXInitPosition.end() && I->second == ~0U)
382  return;
383 
384  llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
385  SmallString<256> FnName;
386  {
387  llvm::raw_svector_ostream Out(FnName);
388  getCXXABI().getMangleContext().mangleDynamicInitializer(D, Out);
389  }
390 
391  // Create a variable initialization function.
392  llvm::Function *Fn =
393  CreateGlobalInitOrDestructFunction(FTy, FnName.str(),
395  D->getLocation());
396 
397  auto *ISA = D->getAttr<InitSegAttr>();
399  PerformInit);
400 
401  llvm::GlobalVariable *COMDATKey =
402  supportsCOMDAT() && D->isExternallyVisible() ? Addr : nullptr;
403 
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
407  // entire TU.
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));
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.
421  //
422  // As a consequence, we can put them into their own llvm.global_ctors entry.
423  //
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
432  // too.
433  AddGlobalCtor(Fn, 65535, COMDATKey);
434  } else {
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;
442  }
443  }
444 
445  // Remember that we already emitted the initializer for this global.
446  DelayedCXXInitPosition[D] = ~0U;
447 }
448 
449 void CodeGenModule::EmitCXXThreadLocalInitFunc() {
450  getCXXABI().EmitThreadLocalInitFuncs(
451  *this, CXXThreadLocals, CXXThreadLocalInits, CXXThreadLocalInitVars);
452 
453  CXXThreadLocalInits.clear();
454  CXXThreadLocalInitVars.clear();
455  CXXThreadLocals.clear();
456 }
457 
458 void
459 CodeGenModule::EmitCXXGlobalInitFunc() {
460  while (!CXXGlobalInits.empty() && !CXXGlobalInits.back())
461  CXXGlobalInits.pop_back();
462 
463  if (CXXGlobalInits.empty() && PrioritizedCXXGlobalInits.empty())
464  return;
465 
466  llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
468 
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.
478  I = PrioritizedCXXGlobalInits.begin(),
479  E = PrioritizedCXXGlobalInits.end(); I != E; ) {
481  PrioE = std::upper_bound(I + 1, E, *I, GlobalInitPriorityCmp());
482 
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);
492 
493  for (; I < PrioE; ++I)
494  LocalCXXGlobalInits.push_back(I->second);
495 
496  CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, LocalCXXGlobalInits);
497  AddGlobalCtor(Fn, Priority);
498  }
499  PrioritizedCXXGlobalInits.clear();
500  }
501 
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())
507  FileName = "<null>";
508 
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]))
513  FileName[i] = '_';
514  }
515 
516  llvm::Function *Fn = CreateGlobalInitOrDestructFunction(
517  FTy, llvm::Twine("_GLOBAL__sub_I_", FileName), FI);
518 
519  CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, CXXGlobalInits);
520  AddGlobalCtor(Fn);
521 
522  CXXGlobalInits.clear();
523 }
524 
525 void CodeGenModule::EmitCXXGlobalDtorFunc() {
526  if (CXXGlobalDtors.empty())
527  return;
528 
529  llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false);
530 
531  // Create our global destructor function.
533  llvm::Function *Fn =
534  CreateGlobalInitOrDestructFunction(FTy, "_GLOBAL__D_a", FI);
535 
536  CodeGenFunction(*this).GenerateCXXGlobalDtorsFunc(Fn, CXXGlobalDtors);
537  AddGlobalDtor(Fn);
538 }
539 
540 /// Emit the code necessary to initialize the given global variable.
542  const VarDecl *D,
543  llvm::GlobalVariable *Addr,
544  bool PerformInit) {
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
548 
549  CurEHLocation = D->getLocStart();
550 
552  getTypes().arrangeNullaryFunction(),
554  D->getInit()->getExprLoc());
555 
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);
561  } else {
562  EmitCXXGlobalVarDeclInit(*D, Addr, PerformInit);
563  }
564 
565  FinishFunction();
566 }
567 
568 void
571  Address Guard) {
572  {
573  auto NL = ApplyDebugLocation::CreateEmpty(*this);
575  getTypes().arrangeNullaryFunction(), FunctionArgList());
576  // Emit an artificial location for this function.
577  auto AL = ApplyDebugLocation::CreateArtificial(*this);
578 
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);
595  }
596 
597  RunCleanupsScope Scope(*this);
598 
599  // When building in Objective-C++ ARC mode, create an autorelease pool
600  // around the global initializers.
601  if (getLangOpts().ObjCAutoRefCount && getLangOpts().CPlusPlus) {
604  }
605 
606  for (unsigned i = 0, e = Decls.size(); i != e; ++i)
607  if (Decls[i])
608  EmitRuntimeCall(Decls[i]);
609 
610  Scope.ForceCleanup();
611 
612  if (ExitBlock) {
613  Builder.CreateBr(ExitBlock);
614  EmitBlock(ExitBlock);
615  }
616  }
617 
618  FinishFunction();
619 }
620 
622  llvm::Function *Fn,
623  const std::vector<std::pair<llvm::WeakTrackingVH, llvm::Constant *>>
624  &DtorsAndObjects) {
625  {
626  auto NL = ApplyDebugLocation::CreateEmpty(*this);
628  getTypes().arrangeNullaryFunction(), FunctionArgList());
629  // Emit an artificial location for this function.
630  auto AL = ApplyDebugLocation::CreateArtificial(*this);
631 
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());
640  }
641  }
642 
643  FinishFunction();
644 }
645 
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.
650  Address addr, QualType type, Destroyer *destroyer,
651  bool useEHCleanupForArray, const VarDecl *VD) {
652  FunctionArgList args;
655  args.push_back(&Dst);
656 
657  const CGFunctionInfo &FI =
659  llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(FI);
660  llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction(
661  FTy, "__cxx_global_array_dtor", FI, VD->getLocation());
662 
663  CurEHLocation = VD->getLocStart();
664 
665  StartFunction(VD, getContext().VoidTy, fn, FI, args);
666 
667  emitDestroy(addr, type, destroyer, useEHCleanupForArray);
668 
669  FinishFunction();
670 
671  return fn;
672 }
const CGFunctionInfo & arrangeBuiltinFunctionDeclaration(QualType resultType, const FunctionArgList &args)
A builtin function is a freestanding function using the default C conventions.
Definition: CGCall.cpp:640
void EmitCXXGuardedInitBranch(llvm::Value *NeedsInit, llvm::BasicBlock *InitBlock, llvm::BasicBlock *NoInitBlock, GuardKind Kind, const VarDecl *D)
Emit a branch to select whether or not to perform guarded initialization.
Definition: CGDeclCXX.cpp:263
llvm::IntegerType * IntTy
int
Other implicit parameter.
Definition: Decl.h:1473
Destroyer * getDestroyer(QualType::DestructionKind destructionKind)
Definition: CGDecl.cpp:1461
A (possibly-)qualified type.
Definition: Type.h:653
const CodeGenOptions & getCodeGenOpts() const
llvm::LLVMContext & getLLVMContext()
static AggValueSlot forLValue(const LValue &LV, IsDestructed_t isDestructed, NeedsGCBarriers_t needsGC, IsAliased_t isAliased, IsZeroed_t isZeroed=IsNotZeroed)
Definition: CGValue.h:517
void GenerateCXXGlobalInitFunc(llvm::Function *Fn, ArrayRef< llvm::Function *> CXXThreadLocals, Address Guard=Address::invalid())
GenerateCXXGlobalInitFunc - Generates code for initializing global variables.
Definition: CGDeclCXX.cpp:569
void EmitComplexExprIntoLValue(const Expr *E, LValue dest, bool isInit)
EmitComplexExprIntoLValue - Emit the given expression of complex type and place its result into the s...
VarDecl - An instance of this class is created to represent a variable declaration or definition...
Definition: Decl.h:806
llvm::Value * EmitObjCAutoreleasePoolPush()
Produce the code to do a objc_autoreleasepool_push.
Definition: CGObjC.cpp:2330
llvm::Type * ConvertTypeForMem(QualType T)
ConvertTypeForMem - Convert type T into a llvm::Type.
static void EmitDeclDestroy(CodeGenFunction &CGF, const VarDecl &D, ConstantAddress addr)
Emit code to cause the destruction of the given variable with static storage duration.
Definition: CGDeclCXX.cpp:64
const TargetInfo & getTarget() const
void emitDestroy(Address addr, QualType type, Destroyer *destroyer, bool useEHCleanupForArray)
emitDestroy - Immediately perform the destruction of the given object.
Definition: CGDecl.cpp:1537
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
llvm::Type * ConvertType(QualType T)
ConvertType - Convert type T into a llvm::Type.
RValue EmitReferenceBindingToExpr(const Expr *E)
Emits a reference binding to the passed in expression.
Definition: CGExpr.cpp:531
llvm::Constant * getAddrOfCXXStructor(const CXXMethodDecl *MD, StructorType Type, const CGFunctionInfo *FnInfo=nullptr, llvm::FunctionType *FnType=nullptr, bool DontDefer=false, ForDefinition_t IsForDefinition=NotForDefinition)
Return the address of the constructor/destructor of the given type.
Definition: CGCXX.cpp:238
llvm::CallInst * EmitRuntimeCall(llvm::Value *callee, const Twine &name="")
bool isReferenceType() const
Definition: Type.h:5956
void GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn, const VarDecl *D, llvm::GlobalVariable *Addr, bool PerformInit)
Emit the code necessary to initialize the given global variable.
Definition: CGDeclCXX.cpp:541
void EmitStoreOfScalar(llvm::Value *Value, Address Addr, bool Volatile, QualType Ty, AlignmentSource Source=AlignmentSource::Type, bool isInit=false, bool isNontemporal=false)
EmitStoreOfScalar - Store a scalar value to an address, taking care to appropriately convert from the...
static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF)
Apply TemporaryLocation if it is valid.
Definition: CGDebugInfo.h:651
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:38
TemplateSpecializationKind getTemplateSpecializationKind() const
If this variable is an instantiation of a variable template or a static data member of a class templa...
Definition: Decl.cpp:2373
bool needsEHCleanup(QualType::DestructionKind kind)
Determines whether an EH cleanup is required to destroy a type with the given destruction kind...
void registerGlobalDtorWithAtExit(const VarDecl &D, llvm::Constant *fn, llvm::Constant *addr)
Call atexit() with a function that passes the given argument to the given function.
Definition: CGDeclCXX.cpp:230
bool isObjCWeak() const
Definition: CGValue.h:291
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:39
llvm::BasicBlock * createBasicBlock(const Twine &name="", llvm::Function *parent=nullptr, llvm::BasicBlock *before=nullptr)
createBasicBlock - Create an LLVM basic block.
void ForceCleanup(std::initializer_list< llvm::Value **> ValuesToReload={})
Force the emission of cleanups now, instead of waiting until this object is destroyed.
bool hasTrivialDestructor() const
Determine whether this class has a trivial destructor (C++ [class.dtor]p3)
Definition: DeclCXX.h:1404
CXXDestructorDecl * getDestructor() const
Returns the destructor decl for this class.
Definition: DeclCXX.cpp:1458
virtual bool canCallMismatchedFunctionType() const
Returns true if the target allows calling a function through a pointer with a different signature tha...
Definition: CGCXXABI.h:119
llvm::Constant * CreateRuntimeFunction(llvm::FunctionType *Ty, StringRef Name, llvm::AttributeList ExtraAttrs=llvm::AttributeList(), bool Local=false)
Create a new runtime function with the specified type and name.
virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF, llvm::Value *src, Address dest, bool threadlocal=false)=0
bool isTypeConstant(QualType QTy, bool ExcludeCtorDtor)
isTypeConstant - Determine whether an object of this type can be emitted as a constant.
bool hasAttr() const
Definition: DeclBase.h:535
bool isValid() const
Definition: Address.h:36
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1590
llvm::CallInst * EmitNounwindRuntimeCall(llvm::Value *callee, const Twine &name="")
RValue - This trivial value class is used to represent the result of an expression that is evaluated...
Definition: CGValue.h:39
virtual void mangleDynamicAtExitDestructor(const VarDecl *D, raw_ostream &)=0
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
virtual bool HasThisReturn(GlobalDecl GD) const
Returns true if the given constructor or destructor is one of the kinds that the ABI says returns &#39;th...
Definition: CGCXXABI.h:107
llvm::CallingConv::ID getRuntimeCC() const
void EmitCXXGuardedInit(const VarDecl &D, llvm::GlobalVariable *DeclPtr, bool PerformInit)
Emit code in this function to perform a guarded variable initialization.
Definition: CGDeclCXX.cpp:249
CGObjCRuntime & getObjCRuntime()
Return a reference to the configured Objective-C runtime.
static TypeEvaluationKind getEvaluationKind(QualType T)
getEvaluationKind - Return the TypeEvaluationKind of QualType T.
llvm::Function * generateDestroyHelper(Address addr, QualType type, Destroyer *destroyer, bool useEHCleanupForArray, const VarDecl *VD)
generateDestroyHelper - Generates a helper function which, when invoked, destroys the given object...
Definition: CGDeclCXX.cpp:649
Expr - This represents one expression.
Definition: Expr.h:106
Enters a new scope for capturing cleanups, all of which will be executed once the scope is exited...
const FunctionProtoType * T
const CGFunctionInfo & arrangeNullaryFunction()
A nullary function is a freestanding function of type &#39;void ()&#39;.
Definition: CGCall.cpp:682
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2620
virtual void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D, llvm::GlobalVariable *DeclPtr, bool PerformInit)=0
Emits the guarded initializer and destructor setup for the given variable, given that it couldn&#39;t be ...
TLSKind getTLSKind() const
Definition: Decl.cpp:1883
virtual void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D, llvm::Constant *Dtor, llvm::Constant *Addr)=0
Emit code to force the execution of a destructor during global teardown.
void EmitCXXGlobalVarDeclInit(const VarDecl &D, llvm::Constant *DeclPtr, bool PerformInit)
EmitCXXGlobalVarDeclInit - Create the initializer for a C++ variable with global storage.
Definition: CGDeclCXX.cpp:143
bool isObjCStrong() const
Definition: CGValue.h:294
ASTContext & getContext() const
bool isTemplateInstantiation(TemplateSpecializationKind Kind)
Determine whether this template specialization kind refers to an instantiation of an entity (as oppos...
Definition: Specifiers.h:167
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:35
The l-value was considered opaque, so the alignment was determined from a type.
Kind
Encodes a location in the source.
llvm::Constant * createAtExitStub(const VarDecl &VD, llvm::Constant *Dtor, llvm::Constant *Addr)
Create a stub function, suitable for being passed to atexit, which passes the given address to the gi...
Definition: CGDeclCXX.cpp:197
bool hasGlobalStorage() const
Returns true for all variables that do not have local storage.
Definition: Decl.h:1067
CanQualType VoidTy
Definition: ASTContext.h:996
An aligned address.
Definition: Address.h:25
void StartFunction(GlobalDecl GD, QualType RetTy, llvm::Function *Fn, const CGFunctionInfo &FnInfo, const FunctionArgList &Args, SourceLocation Loc=SourceLocation(), SourceLocation StartLoc=SourceLocation())
Emit code for the start of a function.
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1098
MangleContext & getMangleContext()
Gets the mangle context.
Definition: CGCXXABI.h:97
Complete object dtor.
Definition: ABI.h:36
void Error(SourceLocation loc, StringRef error)
Emit a general error that something can&#39;t be done.
void FinishFunction(SourceLocation EndLoc=SourceLocation())
FinishFunction - Complete IR generation of the current function.
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:216
llvm::Value * EmitScalarExpr(const Expr *E, bool IgnoreResultAssign=false)
EmitScalarExpr - Emit the computation of the specified expression of LLVM scalar type, returning the result.
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:276
llvm::Value * getScalarVal() const
getScalarVal() - Return the Value* of this scalar value.
Definition: CGValue.h:59
CGFunctionInfo - Class to encapsulate the information about a function definition.
This class organizes the cross-function state that is used while generating LLVM code.
CGOpenMPRuntime & getOpenMPRuntime()
Return a reference to the configured OpenMP runtime.
Dataflow Directional Tag Classes.
const Expr * getInit() const
Definition: Decl.h:1212
llvm::Constant * getPointer() const
Definition: Address.h:84
llvm::LoadInst * CreateLoad(Address Addr, const llvm::Twine &Name="")
Definition: CGBuilder.h:70
SourceLocation getLocStart() const LLVM_READONLY
Definition: Decl.h:731
llvm::Function * getIntrinsic(unsigned IID, ArrayRef< llvm::Type *> Tys=None)
llvm::StoreInst * CreateStore(llvm::Value *Val, Address Addr, bool IsVolatile=false)
Definition: CGBuilder.h:108
LValue MakeAddrLValue(Address Addr, QualType T, AlignmentSource Source=AlignmentSource::Type)
void EmitAggExpr(const Expr *E, AggValueSlot AS)
EmitAggExpr - Emit the computation of the specified expression of aggregate type. ...
Definition: CGExprAgg.cpp:1522
virtual void EmitObjCWeakAssign(CodeGen::CodeGenFunction &CGF, llvm::Value *src, Address dest)=0
CodeGenTypes & getTypes() const
T * getAttr() const
Definition: DeclBase.h:531
void EmitScalarInit(const Expr *init, const ValueDecl *D, LValue lvalue, bool capturedByInit)
Definition: CGDecl.cpp:713
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:33
void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false)
EmitBlock - Emit the given block.
Definition: CGStmt.cpp:436
static void EmitDeclInit(CodeGenFunction &CGF, const VarDecl &D, ConstantAddress DeclPtr)
Definition: CGDeclCXX.cpp:27
Represents a C++ struct/union/class.
Definition: DeclCXX.h:299
llvm::Function * CreateGlobalInitOrDestructFunction(llvm::FunctionType *ty, const Twine &name, const CGFunctionInfo &FI, SourceLocation Loc=SourceLocation(), bool TLS=false)
Definition: CGDeclCXX.cpp:300
A specialization of Address that requires the address to be an LLVM Constant.
Definition: Address.h:75
CGCXXABI & getCXXABI() const
void EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr)
Definition: CGObjC.cpp:2443
void GenerateCXXGlobalDtorsFunc(llvm::Function *Fn, const std::vector< std::pair< llvm::WeakTrackingVH, llvm::Constant *>> &DtorsAndObjects)
GenerateCXXGlobalDtorsFunc - Generates code for destroying global variables.
Definition: CGDeclCXX.cpp:621
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF)
Set the IRBuilder to not attach debug locations.
Definition: CGDebugInfo.h:668
bool isLocalVarDecl() const
isLocalVarDecl - Returns true for local variable declarations other than parameters.
Definition: Decl.h:1095
QualType getType() const
Definition: Decl.h:638
LValue - This represents an lvalue references.
Definition: CGValue.h:167
const LangOptions & getLangOpts() const
unsigned getTargetAddressSpace(QualType T) const
Definition: ASTContext.h:2407
LLVM_READONLY bool isPreprocessingNumberBody(unsigned char c)
Return true if this is the body character of a C preprocessing number, which is [a-zA-Z0-9_.
Definition: CharInfo.h:148
SourceLocation getLocation() const
Definition: DeclBase.h:416
bool isExternallyVisible() const
Definition: Decl.h:370
static void EmitDeclInvariant(CodeGenFunction &CGF, const VarDecl &D, llvm::Constant *Addr)
Emit code to cause the variable at the given address to be considered as constant from this point onw...
Definition: CGDeclCXX.cpp:123
static OMPLinearClause * Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc, OpenMPLinearClauseKind Modifier, SourceLocation ModifierLoc, SourceLocation ColonLoc, SourceLocation EndLoc, ArrayRef< Expr *> VL, ArrayRef< Expr *> PL, ArrayRef< Expr *> IL, Expr *Step, Expr *CalcStep, Stmt *PreInit, Expr *PostUpdate)
Creates clause with a list of variables VL and a linear step Step.
void Destroyer(CodeGenFunction &CGF, Address addr, QualType ty)
static CharUnits getDeclAlign(Expr *E, CharUnits TypeAlign, ASTContext &Context)
A helper function to get the alignment of a Decl referred to by DeclRefExpr or MemberExpr.
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1524