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CGException.cpp
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1 //===--- CGException.cpp - Emit LLVM Code for C++ exceptions ----*- C++ -*-===//
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 C++ exception related code generation.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CodeGenFunction.h"
15 #include "CGCXXABI.h"
16 #include "CGCleanup.h"
17 #include "CGObjCRuntime.h"
18 #include "ConstantEmitter.h"
19 #include "TargetInfo.h"
20 #include "clang/AST/Mangle.h"
21 #include "clang/AST/StmtCXX.h"
22 #include "clang/AST/StmtObjC.h"
23 #include "clang/AST/StmtVisitor.h"
25 #include "llvm/IR/CallSite.h"
26 #include "llvm/IR/Intrinsics.h"
27 #include "llvm/IR/IntrinsicInst.h"
28 #include "llvm/Support/SaveAndRestore.h"
29 
30 using namespace clang;
31 using namespace CodeGen;
32 
33 static llvm::Constant *getFreeExceptionFn(CodeGenModule &CGM) {
34  // void __cxa_free_exception(void *thrown_exception);
35 
36  llvm::FunctionType *FTy =
37  llvm::FunctionType::get(CGM.VoidTy, CGM.Int8PtrTy, /*IsVarArgs=*/false);
38 
39  return CGM.CreateRuntimeFunction(FTy, "__cxa_free_exception");
40 }
41 
42 static llvm::Constant *getUnexpectedFn(CodeGenModule &CGM) {
43  // void __cxa_call_unexpected(void *thrown_exception);
44 
45  llvm::FunctionType *FTy =
46  llvm::FunctionType::get(CGM.VoidTy, CGM.Int8PtrTy, /*IsVarArgs=*/false);
47 
48  return CGM.CreateRuntimeFunction(FTy, "__cxa_call_unexpected");
49 }
50 
51 llvm::Constant *CodeGenModule::getTerminateFn() {
52  // void __terminate();
53 
54  llvm::FunctionType *FTy =
55  llvm::FunctionType::get(VoidTy, /*IsVarArgs=*/false);
56 
57  StringRef name;
58 
59  // In C++, use std::terminate().
60  if (getLangOpts().CPlusPlus &&
61  getTarget().getCXXABI().isItaniumFamily()) {
62  name = "_ZSt9terminatev";
63  } else if (getLangOpts().CPlusPlus &&
64  getTarget().getCXXABI().isMicrosoft()) {
65  if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015))
66  name = "__std_terminate";
67  else
68  name = "?terminate@@YAXXZ";
69  } else if (getLangOpts().ObjC1 &&
71  name = "objc_terminate";
72  else
73  name = "abort";
74  return CreateRuntimeFunction(FTy, name);
75 }
76 
77 static llvm::Constant *getCatchallRethrowFn(CodeGenModule &CGM,
78  StringRef Name) {
79  llvm::FunctionType *FTy =
80  llvm::FunctionType::get(CGM.VoidTy, CGM.Int8PtrTy, /*IsVarArgs=*/false);
81 
82  return CGM.CreateRuntimeFunction(FTy, Name);
83 }
84 
85 const EHPersonality EHPersonality::GNU_C = { "__gcc_personality_v0", nullptr };
86 const EHPersonality
87 EHPersonality::GNU_C_SJLJ = { "__gcc_personality_sj0", nullptr };
88 const EHPersonality
89 EHPersonality::GNU_C_SEH = { "__gcc_personality_seh0", nullptr };
90 const EHPersonality
91 EHPersonality::NeXT_ObjC = { "__objc_personality_v0", nullptr };
92 const EHPersonality
93 EHPersonality::GNU_CPlusPlus = { "__gxx_personality_v0", nullptr };
94 const EHPersonality
95 EHPersonality::GNU_CPlusPlus_SJLJ = { "__gxx_personality_sj0", nullptr };
96 const EHPersonality
97 EHPersonality::GNU_CPlusPlus_SEH = { "__gxx_personality_seh0", nullptr };
98 const EHPersonality
99 EHPersonality::GNU_ObjC = {"__gnu_objc_personality_v0", "objc_exception_throw"};
100 const EHPersonality
101 EHPersonality::GNU_ObjC_SJLJ = {"__gnu_objc_personality_sj0", "objc_exception_throw"};
102 const EHPersonality
103 EHPersonality::GNU_ObjC_SEH = {"__gnu_objc_personality_seh0", "objc_exception_throw"};
104 const EHPersonality
105 EHPersonality::GNU_ObjCXX = { "__gnustep_objcxx_personality_v0", nullptr };
106 const EHPersonality
107 EHPersonality::GNUstep_ObjC = { "__gnustep_objc_personality_v0", nullptr };
108 const EHPersonality
109 EHPersonality::MSVC_except_handler = { "_except_handler3", nullptr };
110 const EHPersonality
111 EHPersonality::MSVC_C_specific_handler = { "__C_specific_handler", nullptr };
112 const EHPersonality
113 EHPersonality::MSVC_CxxFrameHandler3 = { "__CxxFrameHandler3", nullptr };
114 
115 static const EHPersonality &getCPersonality(const llvm::Triple &T,
116  const LangOptions &L) {
117  if (L.SjLjExceptions)
119  if (L.DWARFExceptions)
120  return EHPersonality::GNU_C;
121  if (T.isWindowsMSVCEnvironment())
122  return EHPersonality::MSVC_CxxFrameHandler3;
123  if (L.SEHExceptions)
125  return EHPersonality::GNU_C;
126 }
127 
128 static const EHPersonality &getObjCPersonality(const llvm::Triple &T,
129  const LangOptions &L) {
130  switch (L.ObjCRuntime.getKind()) {
132  return getCPersonality(T, L);
133  case ObjCRuntime::MacOSX:
134  case ObjCRuntime::iOS:
136  if (T.isWindowsMSVCEnvironment())
137  return EHPersonality::MSVC_CxxFrameHandler3;
140  if (L.ObjCRuntime.getVersion() >= VersionTuple(1, 7))
141  return EHPersonality::GNUstep_ObjC;
142  LLVM_FALLTHROUGH;
143  case ObjCRuntime::GCC:
144  case ObjCRuntime::ObjFW:
145  if (L.SjLjExceptions)
147  if (L.SEHExceptions)
150  }
151  llvm_unreachable("bad runtime kind");
152 }
153 
154 static const EHPersonality &getCXXPersonality(const llvm::Triple &T,
155  const LangOptions &L) {
156  if (L.SjLjExceptions)
158  if (L.DWARFExceptions)
160  if (T.isWindowsMSVCEnvironment())
161  return EHPersonality::MSVC_CxxFrameHandler3;
162  if (L.SEHExceptions)
165 }
166 
167 /// Determines the personality function to use when both C++
168 /// and Objective-C exceptions are being caught.
169 static const EHPersonality &getObjCXXPersonality(const llvm::Triple &T,
170  const LangOptions &L) {
171  switch (L.ObjCRuntime.getKind()) {
172  // In the fragile ABI, just use C++ exception handling and hope
173  // they're not doing crazy exception mixing.
175  return getCXXPersonality(T, L);
176 
177  // The ObjC personality defers to the C++ personality for non-ObjC
178  // handlers. Unlike the C++ case, we use the same personality
179  // function on targets using (backend-driven) SJLJ EH.
180  case ObjCRuntime::MacOSX:
181  case ObjCRuntime::iOS:
183  return getObjCPersonality(T, L);
184 
187 
188  // The GCC runtime's personality function inherently doesn't support
189  // mixed EH. Use the ObjC personality just to avoid returning null.
190  case ObjCRuntime::GCC:
191  case ObjCRuntime::ObjFW:
192  return getObjCPersonality(T, L);
193  }
194  llvm_unreachable("bad runtime kind");
195 }
196 
197 static const EHPersonality &getSEHPersonalityMSVC(const llvm::Triple &T) {
198  if (T.getArch() == llvm::Triple::x86)
199  return EHPersonality::MSVC_except_handler;
201 }
202 
204  const FunctionDecl *FD) {
205  const llvm::Triple &T = CGM.getTarget().getTriple();
206  const LangOptions &L = CGM.getLangOpts();
207 
208  // Functions using SEH get an SEH personality.
209  if (FD && FD->usesSEHTry())
210  return getSEHPersonalityMSVC(T);
211 
212  if (L.ObjC1)
213  return L.CPlusPlus ? getObjCXXPersonality(T, L) : getObjCPersonality(T, L);
214  return L.CPlusPlus ? getCXXPersonality(T, L) : getCPersonality(T, L);
215 }
216 
218  const auto *FD = CGF.CurCodeDecl;
219  // For outlined finallys and filters, use the SEH personality in case they
220  // contain more SEH. This mostly only affects finallys. Filters could
221  // hypothetically use gnu statement expressions to sneak in nested SEH.
222  FD = FD ? FD : CGF.CurSEHParent;
223  return get(CGF.CGM, dyn_cast_or_null<FunctionDecl>(FD));
224 }
225 
226 static llvm::Constant *getPersonalityFn(CodeGenModule &CGM,
227  const EHPersonality &Personality) {
228  return CGM.CreateRuntimeFunction(llvm::FunctionType::get(CGM.Int32Ty, true),
229  Personality.PersonalityFn,
230  llvm::AttributeList(), /*Local=*/true);
231 }
232 
233 static llvm::Constant *getOpaquePersonalityFn(CodeGenModule &CGM,
234  const EHPersonality &Personality) {
235  llvm::Constant *Fn = getPersonalityFn(CGM, Personality);
236  return llvm::ConstantExpr::getBitCast(Fn, CGM.Int8PtrTy);
237 }
238 
239 /// Check whether a landingpad instruction only uses C++ features.
240 static bool LandingPadHasOnlyCXXUses(llvm::LandingPadInst *LPI) {
241  for (unsigned I = 0, E = LPI->getNumClauses(); I != E; ++I) {
242  // Look for something that would've been returned by the ObjC
243  // runtime's GetEHType() method.
244  llvm::Value *Val = LPI->getClause(I)->stripPointerCasts();
245  if (LPI->isCatch(I)) {
246  // Check if the catch value has the ObjC prefix.
247  if (llvm::GlobalVariable *GV = dyn_cast<llvm::GlobalVariable>(Val))
248  // ObjC EH selector entries are always global variables with
249  // names starting like this.
250  if (GV->getName().startswith("OBJC_EHTYPE"))
251  return false;
252  } else {
253  // Check if any of the filter values have the ObjC prefix.
254  llvm::Constant *CVal = cast<llvm::Constant>(Val);
255  for (llvm::User::op_iterator
256  II = CVal->op_begin(), IE = CVal->op_end(); II != IE; ++II) {
257  if (llvm::GlobalVariable *GV =
258  cast<llvm::GlobalVariable>((*II)->stripPointerCasts()))
259  // ObjC EH selector entries are always global variables with
260  // names starting like this.
261  if (GV->getName().startswith("OBJC_EHTYPE"))
262  return false;
263  }
264  }
265  }
266  return true;
267 }
268 
269 /// Check whether a personality function could reasonably be swapped
270 /// for a C++ personality function.
271 static bool PersonalityHasOnlyCXXUses(llvm::Constant *Fn) {
272  for (llvm::User *U : Fn->users()) {
273  // Conditionally white-list bitcasts.
274  if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(U)) {
275  if (CE->getOpcode() != llvm::Instruction::BitCast) return false;
276  if (!PersonalityHasOnlyCXXUses(CE))
277  return false;
278  continue;
279  }
280 
281  // Otherwise it must be a function.
282  llvm::Function *F = dyn_cast<llvm::Function>(U);
283  if (!F) return false;
284 
285  for (auto BB = F->begin(), E = F->end(); BB != E; ++BB) {
286  if (BB->isLandingPad())
287  if (!LandingPadHasOnlyCXXUses(BB->getLandingPadInst()))
288  return false;
289  }
290  }
291 
292  return true;
293 }
294 
295 /// Try to use the C++ personality function in ObjC++. Not doing this
296 /// can cause some incompatibilities with gcc, which is more
297 /// aggressive about only using the ObjC++ personality in a function
298 /// when it really needs it.
299 void CodeGenModule::SimplifyPersonality() {
300  // If we're not in ObjC++ -fexceptions, there's nothing to do.
301  if (!LangOpts.CPlusPlus || !LangOpts.ObjC1 || !LangOpts.Exceptions)
302  return;
303 
304  // Both the problem this endeavors to fix and the way the logic
305  // above works is specific to the NeXT runtime.
306  if (!LangOpts.ObjCRuntime.isNeXTFamily())
307  return;
308 
309  const EHPersonality &ObjCXX = EHPersonality::get(*this, /*FD=*/nullptr);
310  const EHPersonality &CXX =
311  getCXXPersonality(getTarget().getTriple(), LangOpts);
312  if (&ObjCXX == &CXX)
313  return;
314 
315  assert(std::strcmp(ObjCXX.PersonalityFn, CXX.PersonalityFn) != 0 &&
316  "Different EHPersonalities using the same personality function.");
317 
318  llvm::Function *Fn = getModule().getFunction(ObjCXX.PersonalityFn);
319 
320  // Nothing to do if it's unused.
321  if (!Fn || Fn->use_empty()) return;
322 
323  // Can't do the optimization if it has non-C++ uses.
324  if (!PersonalityHasOnlyCXXUses(Fn)) return;
325 
326  // Create the C++ personality function and kill off the old
327  // function.
328  llvm::Constant *CXXFn = getPersonalityFn(*this, CXX);
329 
330  // This can happen if the user is screwing with us.
331  if (Fn->getType() != CXXFn->getType()) return;
332 
333  Fn->replaceAllUsesWith(CXXFn);
334  Fn->eraseFromParent();
335 }
336 
337 /// Returns the value to inject into a selector to indicate the
338 /// presence of a catch-all.
339 static llvm::Constant *getCatchAllValue(CodeGenFunction &CGF) {
340  // Possibly we should use @llvm.eh.catch.all.value here.
341  return llvm::ConstantPointerNull::get(CGF.Int8PtrTy);
342 }
343 
344 namespace {
345  /// A cleanup to free the exception object if its initialization
346  /// throws.
347  struct FreeException final : EHScopeStack::Cleanup {
348  llvm::Value *exn;
349  FreeException(llvm::Value *exn) : exn(exn) {}
350  void Emit(CodeGenFunction &CGF, Flags flags) override {
352  }
353  };
354 } // end anonymous namespace
355 
356 // Emits an exception expression into the given location. This
357 // differs from EmitAnyExprToMem only in that, if a final copy-ctor
358 // call is required, an exception within that copy ctor causes
359 // std::terminate to be invoked.
361  // Make sure the exception object is cleaned up if there's an
362  // exception during initialization.
363  pushFullExprCleanup<FreeException>(EHCleanup, addr.getPointer());
364  EHScopeStack::stable_iterator cleanup = EHStack.stable_begin();
365 
366  // __cxa_allocate_exception returns a void*; we need to cast this
367  // to the appropriate type for the object.
368  llvm::Type *ty = ConvertTypeForMem(e->getType())->getPointerTo();
369  Address typedAddr = Builder.CreateBitCast(addr, ty);
370 
371  // FIXME: this isn't quite right! If there's a final unelided call
372  // to a copy constructor, then according to [except.terminate]p1 we
373  // must call std::terminate() if that constructor throws, because
374  // technically that copy occurs after the exception expression is
375  // evaluated but before the exception is caught. But the best way
376  // to handle that is to teach EmitAggExpr to do the final copy
377  // differently if it can't be elided.
378  EmitAnyExprToMem(e, typedAddr, e->getType().getQualifiers(),
379  /*IsInit*/ true);
380 
381  // Deactivate the cleanup block.
382  DeactivateCleanupBlock(cleanup,
383  cast<llvm::Instruction>(typedAddr.getPointer()));
384 }
385 
387  if (!ExceptionSlot)
388  ExceptionSlot = CreateTempAlloca(Int8PtrTy, "exn.slot");
389  return Address(ExceptionSlot, getPointerAlign());
390 }
391 
393  if (!EHSelectorSlot)
394  EHSelectorSlot = CreateTempAlloca(Int32Ty, "ehselector.slot");
395  return Address(EHSelectorSlot, CharUnits::fromQuantity(4));
396 }
397 
399  return Builder.CreateLoad(getExceptionSlot(), "exn");
400 }
401 
403  return Builder.CreateLoad(getEHSelectorSlot(), "sel");
404 }
405 
407  bool KeepInsertionPoint) {
408  if (const Expr *SubExpr = E->getSubExpr()) {
409  QualType ThrowType = SubExpr->getType();
410  if (ThrowType->isObjCObjectPointerType()) {
411  const Stmt *ThrowStmt = E->getSubExpr();
412  const ObjCAtThrowStmt S(E->getExprLoc(), const_cast<Stmt *>(ThrowStmt));
413  CGM.getObjCRuntime().EmitThrowStmt(*this, S, false);
414  } else {
415  CGM.getCXXABI().emitThrow(*this, E);
416  }
417  } else {
418  CGM.getCXXABI().emitRethrow(*this, /*isNoReturn=*/true);
419  }
420 
421  // throw is an expression, and the expression emitters expect us
422  // to leave ourselves at a valid insertion point.
423  if (KeepInsertionPoint)
424  EmitBlock(createBasicBlock("throw.cont"));
425 }
426 
428  if (!CGM.getLangOpts().CXXExceptions)
429  return;
430 
431  const FunctionDecl* FD = dyn_cast_or_null<FunctionDecl>(D);
432  if (!FD) {
433  // Check if CapturedDecl is nothrow and create terminate scope for it.
434  if (const CapturedDecl* CD = dyn_cast_or_null<CapturedDecl>(D)) {
435  if (CD->isNothrow())
436  EHStack.pushTerminate();
437  }
438  return;
439  }
440  const FunctionProtoType *Proto = FD->getType()->getAs<FunctionProtoType>();
441  if (!Proto)
442  return;
443 
445  if (isNoexceptExceptionSpec(EST) && Proto->canThrow() == CT_Cannot) {
446  // noexcept functions are simple terminate scopes.
447  EHStack.pushTerminate();
448  } else if (EST == EST_Dynamic || EST == EST_DynamicNone) {
449  // TODO: Revisit exception specifications for the MS ABI. There is a way to
450  // encode these in an object file but MSVC doesn't do anything with it.
451  if (getTarget().getCXXABI().isMicrosoft())
452  return;
453  unsigned NumExceptions = Proto->getNumExceptions();
454  EHFilterScope *Filter = EHStack.pushFilter(NumExceptions);
455 
456  for (unsigned I = 0; I != NumExceptions; ++I) {
457  QualType Ty = Proto->getExceptionType(I);
458  QualType ExceptType = Ty.getNonReferenceType().getUnqualifiedType();
459  llvm::Value *EHType = CGM.GetAddrOfRTTIDescriptor(ExceptType,
460  /*ForEH=*/true);
461  Filter->setFilter(I, EHType);
462  }
463  }
464 }
465 
466 /// Emit the dispatch block for a filter scope if necessary.
468  EHFilterScope &filterScope) {
469  llvm::BasicBlock *dispatchBlock = filterScope.getCachedEHDispatchBlock();
470  if (!dispatchBlock) return;
471  if (dispatchBlock->use_empty()) {
472  delete dispatchBlock;
473  return;
474  }
475 
476  CGF.EmitBlockAfterUses(dispatchBlock);
477 
478  // If this isn't a catch-all filter, we need to check whether we got
479  // here because the filter triggered.
480  if (filterScope.getNumFilters()) {
481  // Load the selector value.
482  llvm::Value *selector = CGF.getSelectorFromSlot();
483  llvm::BasicBlock *unexpectedBB = CGF.createBasicBlock("ehspec.unexpected");
484 
485  llvm::Value *zero = CGF.Builder.getInt32(0);
486  llvm::Value *failsFilter =
487  CGF.Builder.CreateICmpSLT(selector, zero, "ehspec.fails");
488  CGF.Builder.CreateCondBr(failsFilter, unexpectedBB,
489  CGF.getEHResumeBlock(false));
490 
491  CGF.EmitBlock(unexpectedBB);
492  }
493 
494  // Call __cxa_call_unexpected. This doesn't need to be an invoke
495  // because __cxa_call_unexpected magically filters exceptions
496  // according to the last landing pad the exception was thrown
497  // into. Seriously.
498  llvm::Value *exn = CGF.getExceptionFromSlot();
499  CGF.EmitRuntimeCall(getUnexpectedFn(CGF.CGM), exn)
500  ->setDoesNotReturn();
501  CGF.Builder.CreateUnreachable();
502 }
503 
505  if (!CGM.getLangOpts().CXXExceptions)
506  return;
507 
508  const FunctionDecl* FD = dyn_cast_or_null<FunctionDecl>(D);
509  if (!FD) {
510  // Check if CapturedDecl is nothrow and pop terminate scope for it.
511  if (const CapturedDecl* CD = dyn_cast_or_null<CapturedDecl>(D)) {
512  if (CD->isNothrow())
513  EHStack.popTerminate();
514  }
515  return;
516  }
517  const FunctionProtoType *Proto = FD->getType()->getAs<FunctionProtoType>();
518  if (!Proto)
519  return;
520 
522  if (isNoexceptExceptionSpec(EST) && Proto->canThrow() == CT_Cannot) {
523  EHStack.popTerminate();
524  } else if (EST == EST_Dynamic || EST == EST_DynamicNone) {
525  // TODO: Revisit exception specifications for the MS ABI. There is a way to
526  // encode these in an object file but MSVC doesn't do anything with it.
527  if (getTarget().getCXXABI().isMicrosoft())
528  return;
529  EHFilterScope &filterScope = cast<EHFilterScope>(*EHStack.begin());
530  emitFilterDispatchBlock(*this, filterScope);
531  EHStack.popFilter();
532  }
533 }
534 
536  EnterCXXTryStmt(S);
537  EmitStmt(S.getTryBlock());
538  ExitCXXTryStmt(S);
539 }
540 
541 void CodeGenFunction::EnterCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock) {
542  unsigned NumHandlers = S.getNumHandlers();
543  EHCatchScope *CatchScope = EHStack.pushCatch(NumHandlers);
544 
545  for (unsigned I = 0; I != NumHandlers; ++I) {
546  const CXXCatchStmt *C = S.getHandler(I);
547 
548  llvm::BasicBlock *Handler = createBasicBlock("catch");
549  if (C->getExceptionDecl()) {
550  // FIXME: Dropping the reference type on the type into makes it
551  // impossible to correctly implement catch-by-reference
552  // semantics for pointers. Unfortunately, this is what all
553  // existing compilers do, and it's not clear that the standard
554  // personality routine is capable of doing this right. See C++ DR 388:
555  // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#388
556  Qualifiers CaughtTypeQuals;
557  QualType CaughtType = CGM.getContext().getUnqualifiedArrayType(
558  C->getCaughtType().getNonReferenceType(), CaughtTypeQuals);
559 
560  CatchTypeInfo TypeInfo{nullptr, 0};
561  if (CaughtType->isObjCObjectPointerType())
562  TypeInfo.RTTI = CGM.getObjCRuntime().GetEHType(CaughtType);
563  else
564  TypeInfo = CGM.getCXXABI().getAddrOfCXXCatchHandlerType(
565  CaughtType, C->getCaughtType());
566  CatchScope->setHandler(I, TypeInfo, Handler);
567  } else {
568  // No exception decl indicates '...', a catch-all.
569  CatchScope->setHandler(I, CGM.getCXXABI().getCatchAllTypeInfo(), Handler);
570  }
571  }
572 }
573 
574 llvm::BasicBlock *
576  if (EHPersonality::get(*this).usesFuncletPads())
577  return getMSVCDispatchBlock(si);
578 
579  // The dispatch block for the end of the scope chain is a block that
580  // just resumes unwinding.
581  if (si == EHStack.stable_end())
582  return getEHResumeBlock(true);
583 
584  // Otherwise, we should look at the actual scope.
585  EHScope &scope = *EHStack.find(si);
586 
587  llvm::BasicBlock *dispatchBlock = scope.getCachedEHDispatchBlock();
588  if (!dispatchBlock) {
589  switch (scope.getKind()) {
590  case EHScope::Catch: {
591  // Apply a special case to a single catch-all.
592  EHCatchScope &catchScope = cast<EHCatchScope>(scope);
593  if (catchScope.getNumHandlers() == 1 &&
594  catchScope.getHandler(0).isCatchAll()) {
595  dispatchBlock = catchScope.getHandler(0).Block;
596 
597  // Otherwise, make a dispatch block.
598  } else {
599  dispatchBlock = createBasicBlock("catch.dispatch");
600  }
601  break;
602  }
603 
604  case EHScope::Cleanup:
605  dispatchBlock = createBasicBlock("ehcleanup");
606  break;
607 
608  case EHScope::Filter:
609  dispatchBlock = createBasicBlock("filter.dispatch");
610  break;
611 
612  case EHScope::Terminate:
613  dispatchBlock = getTerminateHandler();
614  break;
615 
616  case EHScope::PadEnd:
617  llvm_unreachable("PadEnd unnecessary for Itanium!");
618  }
619  scope.setCachedEHDispatchBlock(dispatchBlock);
620  }
621  return dispatchBlock;
622 }
623 
624 llvm::BasicBlock *
626  // Returning nullptr indicates that the previous dispatch block should unwind
627  // to caller.
628  if (SI == EHStack.stable_end())
629  return nullptr;
630 
631  // Otherwise, we should look at the actual scope.
632  EHScope &EHS = *EHStack.find(SI);
633 
634  llvm::BasicBlock *DispatchBlock = EHS.getCachedEHDispatchBlock();
635  if (DispatchBlock)
636  return DispatchBlock;
637 
638  if (EHS.getKind() == EHScope::Terminate)
639  DispatchBlock = getTerminateFunclet();
640  else
641  DispatchBlock = createBasicBlock();
642  CGBuilderTy Builder(*this, DispatchBlock);
643 
644  switch (EHS.getKind()) {
645  case EHScope::Catch:
646  DispatchBlock->setName("catch.dispatch");
647  break;
648 
649  case EHScope::Cleanup:
650  DispatchBlock->setName("ehcleanup");
651  break;
652 
653  case EHScope::Filter:
654  llvm_unreachable("exception specifications not handled yet!");
655 
656  case EHScope::Terminate:
657  DispatchBlock->setName("terminate");
658  break;
659 
660  case EHScope::PadEnd:
661  llvm_unreachable("PadEnd dispatch block missing!");
662  }
663  EHS.setCachedEHDispatchBlock(DispatchBlock);
664  return DispatchBlock;
665 }
666 
667 /// Check whether this is a non-EH scope, i.e. a scope which doesn't
668 /// affect exception handling. Currently, the only non-EH scopes are
669 /// normal-only cleanup scopes.
670 static bool isNonEHScope(const EHScope &S) {
671  switch (S.getKind()) {
672  case EHScope::Cleanup:
673  return !cast<EHCleanupScope>(S).isEHCleanup();
674  case EHScope::Filter:
675  case EHScope::Catch:
676  case EHScope::Terminate:
677  case EHScope::PadEnd:
678  return false;
679  }
680 
681  llvm_unreachable("Invalid EHScope Kind!");
682 }
683 
685  assert(EHStack.requiresLandingPad());
686  assert(!EHStack.empty());
687 
688  // If exceptions are disabled and SEH is not in use, then there is no invoke
689  // destination. SEH "works" even if exceptions are off. In practice, this
690  // means that C++ destructors and other EH cleanups don't run, which is
691  // consistent with MSVC's behavior.
692  const LangOptions &LO = CGM.getLangOpts();
693  if (!LO.Exceptions) {
694  if (!LO.Borland && !LO.MicrosoftExt)
695  return nullptr;
696  if (!currentFunctionUsesSEHTry())
697  return nullptr;
698  }
699 
700  // CUDA device code doesn't have exceptions.
701  if (LO.CUDA && LO.CUDAIsDevice)
702  return nullptr;
703 
704  // Check the innermost scope for a cached landing pad. If this is
705  // a non-EH cleanup, we'll check enclosing scopes in EmitLandingPad.
706  llvm::BasicBlock *LP = EHStack.begin()->getCachedLandingPad();
707  if (LP) return LP;
708 
709  const EHPersonality &Personality = EHPersonality::get(*this);
710 
711  if (!CurFn->hasPersonalityFn())
712  CurFn->setPersonalityFn(getOpaquePersonalityFn(CGM, Personality));
713 
714  if (Personality.usesFuncletPads()) {
715  // We don't need separate landing pads in the funclet model.
716  LP = getEHDispatchBlock(EHStack.getInnermostEHScope());
717  } else {
718  // Build the landing pad for this scope.
719  LP = EmitLandingPad();
720  }
721 
722  assert(LP);
723 
724  // Cache the landing pad on the innermost scope. If this is a
725  // non-EH scope, cache the landing pad on the enclosing scope, too.
726  for (EHScopeStack::iterator ir = EHStack.begin(); true; ++ir) {
727  ir->setCachedLandingPad(LP);
728  if (!isNonEHScope(*ir)) break;
729  }
730 
731  return LP;
732 }
733 
734 llvm::BasicBlock *CodeGenFunction::EmitLandingPad() {
735  assert(EHStack.requiresLandingPad());
736 
737  EHScope &innermostEHScope = *EHStack.find(EHStack.getInnermostEHScope());
738  switch (innermostEHScope.getKind()) {
739  case EHScope::Terminate:
740  return getTerminateLandingPad();
741 
742  case EHScope::PadEnd:
743  llvm_unreachable("PadEnd unnecessary for Itanium!");
744 
745  case EHScope::Catch:
746  case EHScope::Cleanup:
747  case EHScope::Filter:
748  if (llvm::BasicBlock *lpad = innermostEHScope.getCachedLandingPad())
749  return lpad;
750  }
751 
752  // Save the current IR generation state.
753  CGBuilderTy::InsertPoint savedIP = Builder.saveAndClearIP();
754  auto DL = ApplyDebugLocation::CreateDefaultArtificial(*this, CurEHLocation);
755 
756  // Create and configure the landing pad.
757  llvm::BasicBlock *lpad = createBasicBlock("lpad");
758  EmitBlock(lpad);
759 
760  llvm::LandingPadInst *LPadInst =
761  Builder.CreateLandingPad(llvm::StructType::get(Int8PtrTy, Int32Ty), 0);
762 
763  llvm::Value *LPadExn = Builder.CreateExtractValue(LPadInst, 0);
764  Builder.CreateStore(LPadExn, getExceptionSlot());
765  llvm::Value *LPadSel = Builder.CreateExtractValue(LPadInst, 1);
766  Builder.CreateStore(LPadSel, getEHSelectorSlot());
767 
768  // Save the exception pointer. It's safe to use a single exception
769  // pointer per function because EH cleanups can never have nested
770  // try/catches.
771  // Build the landingpad instruction.
772 
773  // Accumulate all the handlers in scope.
774  bool hasCatchAll = false;
775  bool hasCleanup = false;
776  bool hasFilter = false;
777  SmallVector<llvm::Value*, 4> filterTypes;
778  llvm::SmallPtrSet<llvm::Value*, 4> catchTypes;
779  for (EHScopeStack::iterator I = EHStack.begin(), E = EHStack.end(); I != E;
780  ++I) {
781 
782  switch (I->getKind()) {
783  case EHScope::Cleanup:
784  // If we have a cleanup, remember that.
785  hasCleanup = (hasCleanup || cast<EHCleanupScope>(*I).isEHCleanup());
786  continue;
787 
788  case EHScope::Filter: {
789  assert(I.next() == EHStack.end() && "EH filter is not end of EH stack");
790  assert(!hasCatchAll && "EH filter reached after catch-all");
791 
792  // Filter scopes get added to the landingpad in weird ways.
793  EHFilterScope &filter = cast<EHFilterScope>(*I);
794  hasFilter = true;
795 
796  // Add all the filter values.
797  for (unsigned i = 0, e = filter.getNumFilters(); i != e; ++i)
798  filterTypes.push_back(filter.getFilter(i));
799  goto done;
800  }
801 
802  case EHScope::Terminate:
803  // Terminate scopes are basically catch-alls.
804  assert(!hasCatchAll);
805  hasCatchAll = true;
806  goto done;
807 
808  case EHScope::Catch:
809  break;
810 
811  case EHScope::PadEnd:
812  llvm_unreachable("PadEnd unnecessary for Itanium!");
813  }
814 
815  EHCatchScope &catchScope = cast<EHCatchScope>(*I);
816  for (unsigned hi = 0, he = catchScope.getNumHandlers(); hi != he; ++hi) {
817  EHCatchScope::Handler handler = catchScope.getHandler(hi);
818  assert(handler.Type.Flags == 0 &&
819  "landingpads do not support catch handler flags");
820 
821  // If this is a catch-all, register that and abort.
822  if (!handler.Type.RTTI) {
823  assert(!hasCatchAll);
824  hasCatchAll = true;
825  goto done;
826  }
827 
828  // Check whether we already have a handler for this type.
829  if (catchTypes.insert(handler.Type.RTTI).second)
830  // If not, add it directly to the landingpad.
831  LPadInst->addClause(handler.Type.RTTI);
832  }
833  }
834 
835  done:
836  // If we have a catch-all, add null to the landingpad.
837  assert(!(hasCatchAll && hasFilter));
838  if (hasCatchAll) {
839  LPadInst->addClause(getCatchAllValue(*this));
840 
841  // If we have an EH filter, we need to add those handlers in the
842  // right place in the landingpad, which is to say, at the end.
843  } else if (hasFilter) {
844  // Create a filter expression: a constant array indicating which filter
845  // types there are. The personality routine only lands here if the filter
846  // doesn't match.
848  llvm::ArrayType *AType =
849  llvm::ArrayType::get(!filterTypes.empty() ?
850  filterTypes[0]->getType() : Int8PtrTy,
851  filterTypes.size());
852 
853  for (unsigned i = 0, e = filterTypes.size(); i != e; ++i)
854  Filters.push_back(cast<llvm::Constant>(filterTypes[i]));
855  llvm::Constant *FilterArray = llvm::ConstantArray::get(AType, Filters);
856  LPadInst->addClause(FilterArray);
857 
858  // Also check whether we need a cleanup.
859  if (hasCleanup)
860  LPadInst->setCleanup(true);
861 
862  // Otherwise, signal that we at least have cleanups.
863  } else if (hasCleanup) {
864  LPadInst->setCleanup(true);
865  }
866 
867  assert((LPadInst->getNumClauses() > 0 || LPadInst->isCleanup()) &&
868  "landingpad instruction has no clauses!");
869 
870  // Tell the backend how to generate the landing pad.
871  Builder.CreateBr(getEHDispatchBlock(EHStack.getInnermostEHScope()));
872 
873  // Restore the old IR generation state.
874  Builder.restoreIP(savedIP);
875 
876  return lpad;
877 }
878 
879 static void emitCatchPadBlock(CodeGenFunction &CGF, EHCatchScope &CatchScope) {
880  llvm::BasicBlock *DispatchBlock = CatchScope.getCachedEHDispatchBlock();
881  assert(DispatchBlock);
882 
883  CGBuilderTy::InsertPoint SavedIP = CGF.Builder.saveIP();
884  CGF.EmitBlockAfterUses(DispatchBlock);
885 
886  llvm::Value *ParentPad = CGF.CurrentFuncletPad;
887  if (!ParentPad)
888  ParentPad = llvm::ConstantTokenNone::get(CGF.getLLVMContext());
889  llvm::BasicBlock *UnwindBB =
890  CGF.getEHDispatchBlock(CatchScope.getEnclosingEHScope());
891 
892  unsigned NumHandlers = CatchScope.getNumHandlers();
893  llvm::CatchSwitchInst *CatchSwitch =
894  CGF.Builder.CreateCatchSwitch(ParentPad, UnwindBB, NumHandlers);
895 
896  // Test against each of the exception types we claim to catch.
897  for (unsigned I = 0; I < NumHandlers; ++I) {
898  const EHCatchScope::Handler &Handler = CatchScope.getHandler(I);
899 
900  CatchTypeInfo TypeInfo = Handler.Type;
901  if (!TypeInfo.RTTI)
902  TypeInfo.RTTI = llvm::Constant::getNullValue(CGF.VoidPtrTy);
903 
904  CGF.Builder.SetInsertPoint(Handler.Block);
905 
906  if (EHPersonality::get(CGF).isMSVCXXPersonality()) {
907  CGF.Builder.CreateCatchPad(
908  CatchSwitch, {TypeInfo.RTTI, CGF.Builder.getInt32(TypeInfo.Flags),
909  llvm::Constant::getNullValue(CGF.VoidPtrTy)});
910  } else {
911  CGF.Builder.CreateCatchPad(CatchSwitch, {TypeInfo.RTTI});
912  }
913 
914  CatchSwitch->addHandler(Handler.Block);
915  }
916  CGF.Builder.restoreIP(SavedIP);
917 }
918 
919 /// Emit the structure of the dispatch block for the given catch scope.
920 /// It is an invariant that the dispatch block already exists.
922  EHCatchScope &catchScope) {
923  if (EHPersonality::get(CGF).usesFuncletPads())
924  return emitCatchPadBlock(CGF, catchScope);
925 
926  llvm::BasicBlock *dispatchBlock = catchScope.getCachedEHDispatchBlock();
927  assert(dispatchBlock);
928 
929  // If there's only a single catch-all, getEHDispatchBlock returned
930  // that catch-all as the dispatch block.
931  if (catchScope.getNumHandlers() == 1 &&
932  catchScope.getHandler(0).isCatchAll()) {
933  assert(dispatchBlock == catchScope.getHandler(0).Block);
934  return;
935  }
936 
937  CGBuilderTy::InsertPoint savedIP = CGF.Builder.saveIP();
938  CGF.EmitBlockAfterUses(dispatchBlock);
939 
940  // Select the right handler.
941  llvm::Value *llvm_eh_typeid_for =
942  CGF.CGM.getIntrinsic(llvm::Intrinsic::eh_typeid_for);
943 
944  // Load the selector value.
945  llvm::Value *selector = CGF.getSelectorFromSlot();
946 
947  // Test against each of the exception types we claim to catch.
948  for (unsigned i = 0, e = catchScope.getNumHandlers(); ; ++i) {
949  assert(i < e && "ran off end of handlers!");
950  const EHCatchScope::Handler &handler = catchScope.getHandler(i);
951 
952  llvm::Value *typeValue = handler.Type.RTTI;
953  assert(handler.Type.Flags == 0 &&
954  "landingpads do not support catch handler flags");
955  assert(typeValue && "fell into catch-all case!");
956  typeValue = CGF.Builder.CreateBitCast(typeValue, CGF.Int8PtrTy);
957 
958  // Figure out the next block.
959  bool nextIsEnd;
960  llvm::BasicBlock *nextBlock;
961 
962  // If this is the last handler, we're at the end, and the next
963  // block is the block for the enclosing EH scope.
964  if (i + 1 == e) {
965  nextBlock = CGF.getEHDispatchBlock(catchScope.getEnclosingEHScope());
966  nextIsEnd = true;
967 
968  // If the next handler is a catch-all, we're at the end, and the
969  // next block is that handler.
970  } else if (catchScope.getHandler(i+1).isCatchAll()) {
971  nextBlock = catchScope.getHandler(i+1).Block;
972  nextIsEnd = true;
973 
974  // Otherwise, we're not at the end and we need a new block.
975  } else {
976  nextBlock = CGF.createBasicBlock("catch.fallthrough");
977  nextIsEnd = false;
978  }
979 
980  // Figure out the catch type's index in the LSDA's type table.
981  llvm::CallInst *typeIndex =
982  CGF.Builder.CreateCall(llvm_eh_typeid_for, typeValue);
983  typeIndex->setDoesNotThrow();
984 
985  llvm::Value *matchesTypeIndex =
986  CGF.Builder.CreateICmpEQ(selector, typeIndex, "matches");
987  CGF.Builder.CreateCondBr(matchesTypeIndex, handler.Block, nextBlock);
988 
989  // If the next handler is a catch-all, we're completely done.
990  if (nextIsEnd) {
991  CGF.Builder.restoreIP(savedIP);
992  return;
993  }
994  // Otherwise we need to emit and continue at that block.
995  CGF.EmitBlock(nextBlock);
996  }
997 }
998 
1000  EHCatchScope &catchScope = cast<EHCatchScope>(*EHStack.begin());
1001  if (catchScope.hasEHBranches())
1002  emitCatchDispatchBlock(*this, catchScope);
1003  EHStack.popCatch();
1004 }
1005 
1006 void CodeGenFunction::ExitCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock) {
1007  unsigned NumHandlers = S.getNumHandlers();
1008  EHCatchScope &CatchScope = cast<EHCatchScope>(*EHStack.begin());
1009  assert(CatchScope.getNumHandlers() == NumHandlers);
1010 
1011  // If the catch was not required, bail out now.
1012  if (!CatchScope.hasEHBranches()) {
1013  CatchScope.clearHandlerBlocks();
1014  EHStack.popCatch();
1015  return;
1016  }
1017 
1018  // Emit the structure of the EH dispatch for this catch.
1019  emitCatchDispatchBlock(*this, CatchScope);
1020 
1021  // Copy the handler blocks off before we pop the EH stack. Emitting
1022  // the handlers might scribble on this memory.
1024  CatchScope.begin(), CatchScope.begin() + NumHandlers);
1025 
1026  EHStack.popCatch();
1027 
1028  // The fall-through block.
1029  llvm::BasicBlock *ContBB = createBasicBlock("try.cont");
1030 
1031  // We just emitted the body of the try; jump to the continue block.
1032  if (HaveInsertPoint())
1033  Builder.CreateBr(ContBB);
1034 
1035  // Determine if we need an implicit rethrow for all these catch handlers;
1036  // see the comment below.
1037  bool doImplicitRethrow = false;
1038  if (IsFnTryBlock)
1039  doImplicitRethrow = isa<CXXDestructorDecl>(CurCodeDecl) ||
1040  isa<CXXConstructorDecl>(CurCodeDecl);
1041 
1042  // Perversely, we emit the handlers backwards precisely because we
1043  // want them to appear in source order. In all of these cases, the
1044  // catch block will have exactly one predecessor, which will be a
1045  // particular block in the catch dispatch. However, in the case of
1046  // a catch-all, one of the dispatch blocks will branch to two
1047  // different handlers, and EmitBlockAfterUses will cause the second
1048  // handler to be moved before the first.
1049  for (unsigned I = NumHandlers; I != 0; --I) {
1050  llvm::BasicBlock *CatchBlock = Handlers[I-1].Block;
1051  EmitBlockAfterUses(CatchBlock);
1052 
1053  // Catch the exception if this isn't a catch-all.
1054  const CXXCatchStmt *C = S.getHandler(I-1);
1055 
1056  // Enter a cleanup scope, including the catch variable and the
1057  // end-catch.
1058  RunCleanupsScope CatchScope(*this);
1059 
1060  // Initialize the catch variable and set up the cleanups.
1061  SaveAndRestore<llvm::Instruction *> RestoreCurrentFuncletPad(
1062  CurrentFuncletPad);
1063  CGM.getCXXABI().emitBeginCatch(*this, C);
1064 
1065  // Emit the PGO counter increment.
1066  incrementProfileCounter(C);
1067 
1068  // Perform the body of the catch.
1069  EmitStmt(C->getHandlerBlock());
1070 
1071  // [except.handle]p11:
1072  // The currently handled exception is rethrown if control
1073  // reaches the end of a handler of the function-try-block of a
1074  // constructor or destructor.
1075 
1076  // It is important that we only do this on fallthrough and not on
1077  // return. Note that it's illegal to put a return in a
1078  // constructor function-try-block's catch handler (p14), so this
1079  // really only applies to destructors.
1080  if (doImplicitRethrow && HaveInsertPoint()) {
1081  CGM.getCXXABI().emitRethrow(*this, /*isNoReturn*/false);
1082  Builder.CreateUnreachable();
1083  Builder.ClearInsertionPoint();
1084  }
1085 
1086  // Fall out through the catch cleanups.
1087  CatchScope.ForceCleanup();
1088 
1089  // Branch out of the try.
1090  if (HaveInsertPoint())
1091  Builder.CreateBr(ContBB);
1092  }
1093 
1094  EmitBlock(ContBB);
1095  incrementProfileCounter(&S);
1096 }
1097 
1098 namespace {
1099  struct CallEndCatchForFinally final : EHScopeStack::Cleanup {
1100  llvm::Value *ForEHVar;
1101  llvm::Value *EndCatchFn;
1102  CallEndCatchForFinally(llvm::Value *ForEHVar, llvm::Value *EndCatchFn)
1103  : ForEHVar(ForEHVar), EndCatchFn(EndCatchFn) {}
1104 
1105  void Emit(CodeGenFunction &CGF, Flags flags) override {
1106  llvm::BasicBlock *EndCatchBB = CGF.createBasicBlock("finally.endcatch");
1107  llvm::BasicBlock *CleanupContBB =
1108  CGF.createBasicBlock("finally.cleanup.cont");
1109 
1110  llvm::Value *ShouldEndCatch =
1111  CGF.Builder.CreateFlagLoad(ForEHVar, "finally.endcatch");
1112  CGF.Builder.CreateCondBr(ShouldEndCatch, EndCatchBB, CleanupContBB);
1113  CGF.EmitBlock(EndCatchBB);
1114  CGF.EmitRuntimeCallOrInvoke(EndCatchFn); // catch-all, so might throw
1115  CGF.EmitBlock(CleanupContBB);
1116  }
1117  };
1118 
1119  struct PerformFinally final : EHScopeStack::Cleanup {
1120  const Stmt *Body;
1121  llvm::Value *ForEHVar;
1122  llvm::Value *EndCatchFn;
1123  llvm::Value *RethrowFn;
1124  llvm::Value *SavedExnVar;
1125 
1126  PerformFinally(const Stmt *Body, llvm::Value *ForEHVar,
1127  llvm::Value *EndCatchFn,
1128  llvm::Value *RethrowFn, llvm::Value *SavedExnVar)
1129  : Body(Body), ForEHVar(ForEHVar), EndCatchFn(EndCatchFn),
1130  RethrowFn(RethrowFn), SavedExnVar(SavedExnVar) {}
1131 
1132  void Emit(CodeGenFunction &CGF, Flags flags) override {
1133  // Enter a cleanup to call the end-catch function if one was provided.
1134  if (EndCatchFn)
1135  CGF.EHStack.pushCleanup<CallEndCatchForFinally>(NormalAndEHCleanup,
1136  ForEHVar, EndCatchFn);
1137 
1138  // Save the current cleanup destination in case there are
1139  // cleanups in the finally block.
1140  llvm::Value *SavedCleanupDest =
1142  "cleanup.dest.saved");
1143 
1144  // Emit the finally block.
1145  CGF.EmitStmt(Body);
1146 
1147  // If the end of the finally is reachable, check whether this was
1148  // for EH. If so, rethrow.
1149  if (CGF.HaveInsertPoint()) {
1150  llvm::BasicBlock *RethrowBB = CGF.createBasicBlock("finally.rethrow");
1151  llvm::BasicBlock *ContBB = CGF.createBasicBlock("finally.cont");
1152 
1153  llvm::Value *ShouldRethrow =
1154  CGF.Builder.CreateFlagLoad(ForEHVar, "finally.shouldthrow");
1155  CGF.Builder.CreateCondBr(ShouldRethrow, RethrowBB, ContBB);
1156 
1157  CGF.EmitBlock(RethrowBB);
1158  if (SavedExnVar) {
1159  CGF.EmitRuntimeCallOrInvoke(RethrowFn,
1160  CGF.Builder.CreateAlignedLoad(SavedExnVar, CGF.getPointerAlign()));
1161  } else {
1162  CGF.EmitRuntimeCallOrInvoke(RethrowFn);
1163  }
1164  CGF.Builder.CreateUnreachable();
1165 
1166  CGF.EmitBlock(ContBB);
1167 
1168  // Restore the cleanup destination.
1169  CGF.Builder.CreateStore(SavedCleanupDest,
1170  CGF.getNormalCleanupDestSlot());
1171  }
1172 
1173  // Leave the end-catch cleanup. As an optimization, pretend that
1174  // the fallthrough path was inaccessible; we've dynamically proven
1175  // that we're not in the EH case along that path.
1176  if (EndCatchFn) {
1177  CGBuilderTy::InsertPoint SavedIP = CGF.Builder.saveAndClearIP();
1178  CGF.PopCleanupBlock();
1179  CGF.Builder.restoreIP(SavedIP);
1180  }
1181 
1182  // Now make sure we actually have an insertion point or the
1183  // cleanup gods will hate us.
1184  CGF.EnsureInsertPoint();
1185  }
1186  };
1187 } // end anonymous namespace
1188 
1189 /// Enters a finally block for an implementation using zero-cost
1190 /// exceptions. This is mostly general, but hard-codes some
1191 /// language/ABI-specific behavior in the catch-all sections.
1193  const Stmt *body,
1194  llvm::Constant *beginCatchFn,
1195  llvm::Constant *endCatchFn,
1196  llvm::Constant *rethrowFn) {
1197  assert((beginCatchFn != nullptr) == (endCatchFn != nullptr) &&
1198  "begin/end catch functions not paired");
1199  assert(rethrowFn && "rethrow function is required");
1200 
1201  BeginCatchFn = beginCatchFn;
1202 
1203  // The rethrow function has one of the following two types:
1204  // void (*)()
1205  // void (*)(void*)
1206  // In the latter case we need to pass it the exception object.
1207  // But we can't use the exception slot because the @finally might
1208  // have a landing pad (which would overwrite the exception slot).
1209  llvm::FunctionType *rethrowFnTy =
1210  cast<llvm::FunctionType>(
1211  cast<llvm::PointerType>(rethrowFn->getType())->getElementType());
1212  SavedExnVar = nullptr;
1213  if (rethrowFnTy->getNumParams())
1214  SavedExnVar = CGF.CreateTempAlloca(CGF.Int8PtrTy, "finally.exn");
1215 
1216  // A finally block is a statement which must be executed on any edge
1217  // out of a given scope. Unlike a cleanup, the finally block may
1218  // contain arbitrary control flow leading out of itself. In
1219  // addition, finally blocks should always be executed, even if there
1220  // are no catch handlers higher on the stack. Therefore, we
1221  // surround the protected scope with a combination of a normal
1222  // cleanup (to catch attempts to break out of the block via normal
1223  // control flow) and an EH catch-all (semantically "outside" any try
1224  // statement to which the finally block might have been attached).
1225  // The finally block itself is generated in the context of a cleanup
1226  // which conditionally leaves the catch-all.
1227 
1228  // Jump destination for performing the finally block on an exception
1229  // edge. We'll never actually reach this block, so unreachable is
1230  // fine.
1231  RethrowDest = CGF.getJumpDestInCurrentScope(CGF.getUnreachableBlock());
1232 
1233  // Whether the finally block is being executed for EH purposes.
1234  ForEHVar = CGF.CreateTempAlloca(CGF.Builder.getInt1Ty(), "finally.for-eh");
1235  CGF.Builder.CreateFlagStore(false, ForEHVar);
1236 
1237  // Enter a normal cleanup which will perform the @finally block.
1238  CGF.EHStack.pushCleanup<PerformFinally>(NormalCleanup, body,
1239  ForEHVar, endCatchFn,
1240  rethrowFn, SavedExnVar);
1241 
1242  // Enter a catch-all scope.
1243  llvm::BasicBlock *catchBB = CGF.createBasicBlock("finally.catchall");
1244  EHCatchScope *catchScope = CGF.EHStack.pushCatch(1);
1245  catchScope->setCatchAllHandler(0, catchBB);
1246 }
1247 
1249  // Leave the finally catch-all.
1250  EHCatchScope &catchScope = cast<EHCatchScope>(*CGF.EHStack.begin());
1251  llvm::BasicBlock *catchBB = catchScope.getHandler(0).Block;
1252 
1253  CGF.popCatchScope();
1254 
1255  // If there are any references to the catch-all block, emit it.
1256  if (catchBB->use_empty()) {
1257  delete catchBB;
1258  } else {
1259  CGBuilderTy::InsertPoint savedIP = CGF.Builder.saveAndClearIP();
1260  CGF.EmitBlock(catchBB);
1261 
1262  llvm::Value *exn = nullptr;
1263 
1264  // If there's a begin-catch function, call it.
1265  if (BeginCatchFn) {
1266  exn = CGF.getExceptionFromSlot();
1267  CGF.EmitNounwindRuntimeCall(BeginCatchFn, exn);
1268  }
1269 
1270  // If we need to remember the exception pointer to rethrow later, do so.
1271  if (SavedExnVar) {
1272  if (!exn) exn = CGF.getExceptionFromSlot();
1273  CGF.Builder.CreateAlignedStore(exn, SavedExnVar, CGF.getPointerAlign());
1274  }
1275 
1276  // Tell the cleanups in the finally block that we're do this for EH.
1277  CGF.Builder.CreateFlagStore(true, ForEHVar);
1278 
1279  // Thread a jump through the finally cleanup.
1280  CGF.EmitBranchThroughCleanup(RethrowDest);
1281 
1282  CGF.Builder.restoreIP(savedIP);
1283  }
1284 
1285  // Finally, leave the @finally cleanup.
1286  CGF.PopCleanupBlock();
1287 }
1288 
1290  if (TerminateLandingPad)
1291  return TerminateLandingPad;
1292 
1293  CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP();
1294 
1295  // This will get inserted at the end of the function.
1296  TerminateLandingPad = createBasicBlock("terminate.lpad");
1297  Builder.SetInsertPoint(TerminateLandingPad);
1298 
1299  // Tell the backend that this is a landing pad.
1300  const EHPersonality &Personality = EHPersonality::get(*this);
1301 
1302  if (!CurFn->hasPersonalityFn())
1303  CurFn->setPersonalityFn(getOpaquePersonalityFn(CGM, Personality));
1304 
1305  llvm::LandingPadInst *LPadInst =
1306  Builder.CreateLandingPad(llvm::StructType::get(Int8PtrTy, Int32Ty), 0);
1307  LPadInst->addClause(getCatchAllValue(*this));
1308 
1309  llvm::Value *Exn = nullptr;
1310  if (getLangOpts().CPlusPlus)
1311  Exn = Builder.CreateExtractValue(LPadInst, 0);
1312  llvm::CallInst *terminateCall =
1313  CGM.getCXXABI().emitTerminateForUnexpectedException(*this, Exn);
1314  terminateCall->setDoesNotReturn();
1315  Builder.CreateUnreachable();
1316 
1317  // Restore the saved insertion state.
1318  Builder.restoreIP(SavedIP);
1319 
1320  return TerminateLandingPad;
1321 }
1322 
1324  if (TerminateHandler)
1325  return TerminateHandler;
1326 
1327  // Set up the terminate handler. This block is inserted at the very
1328  // end of the function by FinishFunction.
1329  TerminateHandler = createBasicBlock("terminate.handler");
1330  CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP();
1331  Builder.SetInsertPoint(TerminateHandler);
1332 
1333  llvm::Value *Exn = nullptr;
1334  if (getLangOpts().CPlusPlus)
1335  Exn = getExceptionFromSlot();
1336  llvm::CallInst *terminateCall =
1337  CGM.getCXXABI().emitTerminateForUnexpectedException(*this, Exn);
1338  terminateCall->setDoesNotReturn();
1339  Builder.CreateUnreachable();
1340 
1341  // Restore the saved insertion state.
1342  Builder.restoreIP(SavedIP);
1343 
1344  return TerminateHandler;
1345 }
1346 
1348  assert(EHPersonality::get(*this).usesFuncletPads() &&
1349  "use getTerminateLandingPad for non-funclet EH");
1350 
1351  llvm::BasicBlock *&TerminateFunclet = TerminateFunclets[CurrentFuncletPad];
1352  if (TerminateFunclet)
1353  return TerminateFunclet;
1354 
1355  CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP();
1356 
1357  // Set up the terminate handler. This block is inserted at the very
1358  // end of the function by FinishFunction.
1359  TerminateFunclet = createBasicBlock("terminate.handler");
1360  Builder.SetInsertPoint(TerminateFunclet);
1361 
1362  // Create the cleanuppad using the current parent pad as its token. Use 'none'
1363  // if this is a top-level terminate scope, which is the common case.
1364  SaveAndRestore<llvm::Instruction *> RestoreCurrentFuncletPad(
1365  CurrentFuncletPad);
1366  llvm::Value *ParentPad = CurrentFuncletPad;
1367  if (!ParentPad)
1368  ParentPad = llvm::ConstantTokenNone::get(CGM.getLLVMContext());
1369  CurrentFuncletPad = Builder.CreateCleanupPad(ParentPad);
1370 
1371  // Emit the __std_terminate call.
1372  llvm::CallInst *terminateCall =
1373  CGM.getCXXABI().emitTerminateForUnexpectedException(*this, nullptr);
1374  terminateCall->setDoesNotReturn();
1375  Builder.CreateUnreachable();
1376 
1377  // Restore the saved insertion state.
1378  Builder.restoreIP(SavedIP);
1379 
1380  return TerminateFunclet;
1381 }
1382 
1383 llvm::BasicBlock *CodeGenFunction::getEHResumeBlock(bool isCleanup) {
1384  if (EHResumeBlock) return EHResumeBlock;
1385 
1386  CGBuilderTy::InsertPoint SavedIP = Builder.saveIP();
1387 
1388  // We emit a jump to a notional label at the outermost unwind state.
1389  EHResumeBlock = createBasicBlock("eh.resume");
1390  Builder.SetInsertPoint(EHResumeBlock);
1391 
1392  const EHPersonality &Personality = EHPersonality::get(*this);
1393 
1394  // This can always be a call because we necessarily didn't find
1395  // anything on the EH stack which needs our help.
1396  const char *RethrowName = Personality.CatchallRethrowFn;
1397  if (RethrowName != nullptr && !isCleanup) {
1398  EmitRuntimeCall(getCatchallRethrowFn(CGM, RethrowName),
1399  getExceptionFromSlot())->setDoesNotReturn();
1400  Builder.CreateUnreachable();
1401  Builder.restoreIP(SavedIP);
1402  return EHResumeBlock;
1403  }
1404 
1405  // Recreate the landingpad's return value for the 'resume' instruction.
1406  llvm::Value *Exn = getExceptionFromSlot();
1407  llvm::Value *Sel = getSelectorFromSlot();
1408 
1409  llvm::Type *LPadType = llvm::StructType::get(Exn->getType(), Sel->getType());
1410  llvm::Value *LPadVal = llvm::UndefValue::get(LPadType);
1411  LPadVal = Builder.CreateInsertValue(LPadVal, Exn, 0, "lpad.val");
1412  LPadVal = Builder.CreateInsertValue(LPadVal, Sel, 1, "lpad.val");
1413 
1414  Builder.CreateResume(LPadVal);
1415  Builder.restoreIP(SavedIP);
1416  return EHResumeBlock;
1417 }
1418 
1420  EnterSEHTryStmt(S);
1421  {
1422  JumpDest TryExit = getJumpDestInCurrentScope("__try.__leave");
1423 
1424  SEHTryEpilogueStack.push_back(&TryExit);
1425  EmitStmt(S.getTryBlock());
1426  SEHTryEpilogueStack.pop_back();
1427 
1428  if (!TryExit.getBlock()->use_empty())
1429  EmitBlock(TryExit.getBlock(), /*IsFinished=*/true);
1430  else
1431  delete TryExit.getBlock();
1432  }
1433  ExitSEHTryStmt(S);
1434 }
1435 
1436 namespace {
1437 struct PerformSEHFinally final : EHScopeStack::Cleanup {
1438  llvm::Function *OutlinedFinally;
1439  PerformSEHFinally(llvm::Function *OutlinedFinally)
1440  : OutlinedFinally(OutlinedFinally) {}
1441 
1442  void Emit(CodeGenFunction &CGF, Flags F) override {
1443  ASTContext &Context = CGF.getContext();
1444  CodeGenModule &CGM = CGF.CGM;
1445 
1446  CallArgList Args;
1447 
1448  // Compute the two argument values.
1449  QualType ArgTys[2] = {Context.UnsignedCharTy, Context.VoidPtrTy};
1450  llvm::Value *LocalAddrFn = CGM.getIntrinsic(llvm::Intrinsic::localaddress);
1451  llvm::Value *FP = CGF.Builder.CreateCall(LocalAddrFn);
1452  llvm::Value *IsForEH =
1453  llvm::ConstantInt::get(CGF.ConvertType(ArgTys[0]), F.isForEHCleanup());
1454  Args.add(RValue::get(IsForEH), ArgTys[0]);
1455  Args.add(RValue::get(FP), ArgTys[1]);
1456 
1457  // Arrange a two-arg function info and type.
1458  const CGFunctionInfo &FnInfo =
1459  CGM.getTypes().arrangeBuiltinFunctionCall(Context.VoidTy, Args);
1460 
1461  auto Callee = CGCallee::forDirect(OutlinedFinally);
1462  CGF.EmitCall(FnInfo, Callee, ReturnValueSlot(), Args);
1463  }
1464 };
1465 } // end anonymous namespace
1466 
1467 namespace {
1468 /// Find all local variable captures in the statement.
1469 struct CaptureFinder : ConstStmtVisitor<CaptureFinder> {
1470  CodeGenFunction &ParentCGF;
1471  const VarDecl *ParentThis;
1473  Address SEHCodeSlot = Address::invalid();
1474  CaptureFinder(CodeGenFunction &ParentCGF, const VarDecl *ParentThis)
1475  : ParentCGF(ParentCGF), ParentThis(ParentThis) {}
1476 
1477  // Return true if we need to do any capturing work.
1478  bool foundCaptures() {
1479  return !Captures.empty() || SEHCodeSlot.isValid();
1480  }
1481 
1482  void Visit(const Stmt *S) {
1483  // See if this is a capture, then recurse.
1485  for (const Stmt *Child : S->children())
1486  if (Child)
1487  Visit(Child);
1488  }
1489 
1490  void VisitDeclRefExpr(const DeclRefExpr *E) {
1491  // If this is already a capture, just make sure we capture 'this'.
1493  Captures.insert(ParentThis);
1494  return;
1495  }
1496 
1497  const auto *D = dyn_cast<VarDecl>(E->getDecl());
1498  if (D && D->isLocalVarDeclOrParm() && D->hasLocalStorage())
1499  Captures.insert(D);
1500  }
1501 
1502  void VisitCXXThisExpr(const CXXThisExpr *E) {
1503  Captures.insert(ParentThis);
1504  }
1505 
1506  void VisitCallExpr(const CallExpr *E) {
1507  // We only need to add parent frame allocations for these builtins in x86.
1508  if (ParentCGF.getTarget().getTriple().getArch() != llvm::Triple::x86)
1509  return;
1510 
1511  unsigned ID = E->getBuiltinCallee();
1512  switch (ID) {
1513  case Builtin::BI__exception_code:
1514  case Builtin::BI_exception_code:
1515  // This is the simple case where we are the outermost finally. All we
1516  // have to do here is make sure we escape this and recover it in the
1517  // outlined handler.
1518  if (!SEHCodeSlot.isValid())
1519  SEHCodeSlot = ParentCGF.SEHCodeSlotStack.back();
1520  break;
1521  }
1522  }
1523 };
1524 } // end anonymous namespace
1525 
1527  Address ParentVar,
1528  llvm::Value *ParentFP) {
1529  llvm::CallInst *RecoverCall = nullptr;
1530  CGBuilderTy Builder(*this, AllocaInsertPt);
1531  if (auto *ParentAlloca = dyn_cast<llvm::AllocaInst>(ParentVar.getPointer())) {
1532  // Mark the variable escaped if nobody else referenced it and compute the
1533  // localescape index.
1534  auto InsertPair = ParentCGF.EscapedLocals.insert(
1535  std::make_pair(ParentAlloca, ParentCGF.EscapedLocals.size()));
1536  int FrameEscapeIdx = InsertPair.first->second;
1537  // call i8* @llvm.localrecover(i8* bitcast(@parentFn), i8* %fp, i32 N)
1538  llvm::Function *FrameRecoverFn = llvm::Intrinsic::getDeclaration(
1539  &CGM.getModule(), llvm::Intrinsic::localrecover);
1540  llvm::Constant *ParentI8Fn =
1541  llvm::ConstantExpr::getBitCast(ParentCGF.CurFn, Int8PtrTy);
1542  RecoverCall = Builder.CreateCall(
1543  FrameRecoverFn, {ParentI8Fn, ParentFP,
1544  llvm::ConstantInt::get(Int32Ty, FrameEscapeIdx)});
1545 
1546  } else {
1547  // If the parent didn't have an alloca, we're doing some nested outlining.
1548  // Just clone the existing localrecover call, but tweak the FP argument to
1549  // use our FP value. All other arguments are constants.
1550  auto *ParentRecover =
1551  cast<llvm::IntrinsicInst>(ParentVar.getPointer()->stripPointerCasts());
1552  assert(ParentRecover->getIntrinsicID() == llvm::Intrinsic::localrecover &&
1553  "expected alloca or localrecover in parent LocalDeclMap");
1554  RecoverCall = cast<llvm::CallInst>(ParentRecover->clone());
1555  RecoverCall->setArgOperand(1, ParentFP);
1556  RecoverCall->insertBefore(AllocaInsertPt);
1557  }
1558 
1559  // Bitcast the variable, rename it, and insert it in the local decl map.
1560  llvm::Value *ChildVar =
1561  Builder.CreateBitCast(RecoverCall, ParentVar.getType());
1562  ChildVar->setName(ParentVar.getName());
1563  return Address(ChildVar, ParentVar.getAlignment());
1564 }
1565 
1567  const Stmt *OutlinedStmt,
1568  bool IsFilter) {
1569  // Find all captures in the Stmt.
1570  CaptureFinder Finder(ParentCGF, ParentCGF.CXXABIThisDecl);
1571  Finder.Visit(OutlinedStmt);
1572 
1573  // We can exit early on x86_64 when there are no captures. We just have to
1574  // save the exception code in filters so that __exception_code() works.
1575  if (!Finder.foundCaptures() &&
1576  CGM.getTarget().getTriple().getArch() != llvm::Triple::x86) {
1577  if (IsFilter)
1578  EmitSEHExceptionCodeSave(ParentCGF, nullptr, nullptr);
1579  return;
1580  }
1581 
1582  llvm::Value *EntryFP = nullptr;
1583  CGBuilderTy Builder(CGM, AllocaInsertPt);
1584  if (IsFilter && CGM.getTarget().getTriple().getArch() == llvm::Triple::x86) {
1585  // 32-bit SEH filters need to be careful about FP recovery. The end of the
1586  // EH registration is passed in as the EBP physical register. We can
1587  // recover that with llvm.frameaddress(1).
1588  EntryFP = Builder.CreateCall(
1589  CGM.getIntrinsic(llvm::Intrinsic::frameaddress), {Builder.getInt32(1)});
1590  } else {
1591  // Otherwise, for x64 and 32-bit finally functions, the parent FP is the
1592  // second parameter.
1593  auto AI = CurFn->arg_begin();
1594  ++AI;
1595  EntryFP = &*AI;
1596  }
1597 
1598  llvm::Value *ParentFP = EntryFP;
1599  if (IsFilter) {
1600  // Given whatever FP the runtime provided us in EntryFP, recover the true
1601  // frame pointer of the parent function. We only need to do this in filters,
1602  // since finally funclets recover the parent FP for us.
1603  llvm::Function *RecoverFPIntrin =
1604  CGM.getIntrinsic(llvm::Intrinsic::x86_seh_recoverfp);
1605  llvm::Constant *ParentI8Fn =
1606  llvm::ConstantExpr::getBitCast(ParentCGF.CurFn, Int8PtrTy);
1607  ParentFP = Builder.CreateCall(RecoverFPIntrin, {ParentI8Fn, EntryFP});
1608  }
1609 
1610  // Create llvm.localrecover calls for all captures.
1611  for (const VarDecl *VD : Finder.Captures) {
1612  if (isa<ImplicitParamDecl>(VD)) {
1613  CGM.ErrorUnsupported(VD, "'this' captured by SEH");
1614  CXXThisValue = llvm::UndefValue::get(ConvertTypeForMem(VD->getType()));
1615  continue;
1616  }
1617  if (VD->getType()->isVariablyModifiedType()) {
1618  CGM.ErrorUnsupported(VD, "VLA captured by SEH");
1619  continue;
1620  }
1621  assert((isa<ImplicitParamDecl>(VD) || VD->isLocalVarDeclOrParm()) &&
1622  "captured non-local variable");
1623 
1624  // If this decl hasn't been declared yet, it will be declared in the
1625  // OutlinedStmt.
1626  auto I = ParentCGF.LocalDeclMap.find(VD);
1627  if (I == ParentCGF.LocalDeclMap.end())
1628  continue;
1629 
1630  Address ParentVar = I->second;
1631  setAddrOfLocalVar(
1632  VD, recoverAddrOfEscapedLocal(ParentCGF, ParentVar, ParentFP));
1633  }
1634 
1635  if (Finder.SEHCodeSlot.isValid()) {
1636  SEHCodeSlotStack.push_back(
1637  recoverAddrOfEscapedLocal(ParentCGF, Finder.SEHCodeSlot, ParentFP));
1638  }
1639 
1640  if (IsFilter)
1641  EmitSEHExceptionCodeSave(ParentCGF, ParentFP, EntryFP);
1642 }
1643 
1644 /// Arrange a function prototype that can be called by Windows exception
1645 /// handling personalities. On Win64, the prototype looks like:
1646 /// RetTy func(void *EHPtrs, void *ParentFP);
1648  bool IsFilter,
1649  const Stmt *OutlinedStmt) {
1650  SourceLocation StartLoc = OutlinedStmt->getLocStart();
1651 
1652  // Get the mangled function name.
1653  SmallString<128> Name;
1654  {
1655  llvm::raw_svector_ostream OS(Name);
1656  const FunctionDecl *ParentSEHFn = ParentCGF.CurSEHParent;
1657  assert(ParentSEHFn && "No CurSEHParent!");
1658  MangleContext &Mangler = CGM.getCXXABI().getMangleContext();
1659  if (IsFilter)
1660  Mangler.mangleSEHFilterExpression(ParentSEHFn, OS);
1661  else
1662  Mangler.mangleSEHFinallyBlock(ParentSEHFn, OS);
1663  }
1664 
1665  FunctionArgList Args;
1666  if (CGM.getTarget().getTriple().getArch() != llvm::Triple::x86 || !IsFilter) {
1667  // All SEH finally functions take two parameters. Win64 filters take two
1668  // parameters. Win32 filters take no parameters.
1669  if (IsFilter) {
1670  Args.push_back(ImplicitParamDecl::Create(
1671  getContext(), /*DC=*/nullptr, StartLoc,
1672  &getContext().Idents.get("exception_pointers"),
1674  } else {
1675  Args.push_back(ImplicitParamDecl::Create(
1676  getContext(), /*DC=*/nullptr, StartLoc,
1677  &getContext().Idents.get("abnormal_termination"),
1679  }
1680  Args.push_back(ImplicitParamDecl::Create(
1681  getContext(), /*DC=*/nullptr, StartLoc,
1682  &getContext().Idents.get("frame_pointer"), getContext().VoidPtrTy,
1684  }
1685 
1686  QualType RetTy = IsFilter ? getContext().LongTy : getContext().VoidTy;
1687 
1688  const CGFunctionInfo &FnInfo =
1689  CGM.getTypes().arrangeBuiltinFunctionDeclaration(RetTy, Args);
1690 
1691  llvm::FunctionType *FnTy = CGM.getTypes().GetFunctionType(FnInfo);
1692  llvm::Function *Fn = llvm::Function::Create(
1693  FnTy, llvm::GlobalValue::InternalLinkage, Name.str(), &CGM.getModule());
1694 
1695  IsOutlinedSEHHelper = true;
1696 
1697  StartFunction(GlobalDecl(), RetTy, Fn, FnInfo, Args,
1698  OutlinedStmt->getLocStart(), OutlinedStmt->getLocStart());
1699  CurSEHParent = ParentCGF.CurSEHParent;
1700 
1701  CGM.SetLLVMFunctionAttributes(nullptr, FnInfo, CurFn);
1702  EmitCapturedLocals(ParentCGF, OutlinedStmt, IsFilter);
1703 }
1704 
1705 /// Create a stub filter function that will ultimately hold the code of the
1706 /// filter expression. The EH preparation passes in LLVM will outline the code
1707 /// from the main function body into this stub.
1708 llvm::Function *
1710  const SEHExceptStmt &Except) {
1711  const Expr *FilterExpr = Except.getFilterExpr();
1712  startOutlinedSEHHelper(ParentCGF, true, FilterExpr);
1713 
1714  // Emit the original filter expression, convert to i32, and return.
1715  llvm::Value *R = EmitScalarExpr(FilterExpr);
1716  R = Builder.CreateIntCast(R, ConvertType(getContext().LongTy),
1717  FilterExpr->getType()->isSignedIntegerType());
1718  Builder.CreateStore(R, ReturnValue);
1719 
1720  FinishFunction(FilterExpr->getLocEnd());
1721 
1722  return CurFn;
1723 }
1724 
1725 llvm::Function *
1727  const SEHFinallyStmt &Finally) {
1728  const Stmt *FinallyBlock = Finally.getBlock();
1729  startOutlinedSEHHelper(ParentCGF, false, FinallyBlock);
1730 
1731  // Emit the original filter expression, convert to i32, and return.
1732  EmitStmt(FinallyBlock);
1733 
1734  FinishFunction(FinallyBlock->getLocEnd());
1735 
1736  return CurFn;
1737 }
1738 
1740  llvm::Value *ParentFP,
1741  llvm::Value *EntryFP) {
1742  // Get the pointer to the EXCEPTION_POINTERS struct. This is returned by the
1743  // __exception_info intrinsic.
1744  if (CGM.getTarget().getTriple().getArch() != llvm::Triple::x86) {
1745  // On Win64, the info is passed as the first parameter to the filter.
1746  SEHInfo = &*CurFn->arg_begin();
1747  SEHCodeSlotStack.push_back(
1748  CreateMemTemp(getContext().IntTy, "__exception_code"));
1749  } else {
1750  // On Win32, the EBP on entry to the filter points to the end of an
1751  // exception registration object. It contains 6 32-bit fields, and the info
1752  // pointer is stored in the second field. So, GEP 20 bytes backwards and
1753  // load the pointer.
1754  SEHInfo = Builder.CreateConstInBoundsGEP1_32(Int8Ty, EntryFP, -20);
1755  SEHInfo = Builder.CreateBitCast(SEHInfo, Int8PtrTy->getPointerTo());
1756  SEHInfo = Builder.CreateAlignedLoad(Int8PtrTy, SEHInfo, getPointerAlign());
1757  SEHCodeSlotStack.push_back(recoverAddrOfEscapedLocal(
1758  ParentCGF, ParentCGF.SEHCodeSlotStack.back(), ParentFP));
1759  }
1760 
1761  // Save the exception code in the exception slot to unify exception access in
1762  // the filter function and the landing pad.
1763  // struct EXCEPTION_POINTERS {
1764  // EXCEPTION_RECORD *ExceptionRecord;
1765  // CONTEXT *ContextRecord;
1766  // };
1767  // int exceptioncode = exception_pointers->ExceptionRecord->ExceptionCode;
1768  llvm::Type *RecordTy = CGM.Int32Ty->getPointerTo();
1769  llvm::Type *PtrsTy = llvm::StructType::get(RecordTy, CGM.VoidPtrTy);
1770  llvm::Value *Ptrs = Builder.CreateBitCast(SEHInfo, PtrsTy->getPointerTo());
1771  llvm::Value *Rec = Builder.CreateStructGEP(PtrsTy, Ptrs, 0);
1772  Rec = Builder.CreateAlignedLoad(Rec, getPointerAlign());
1773  llvm::Value *Code = Builder.CreateAlignedLoad(Rec, getIntAlign());
1774  assert(!SEHCodeSlotStack.empty() && "emitting EH code outside of __except");
1775  Builder.CreateStore(Code, SEHCodeSlotStack.back());
1776 }
1777 
1779  // Sema should diagnose calling this builtin outside of a filter context, but
1780  // don't crash if we screw up.
1781  if (!SEHInfo)
1782  return llvm::UndefValue::get(Int8PtrTy);
1783  assert(SEHInfo->getType() == Int8PtrTy);
1784  return SEHInfo;
1785 }
1786 
1788  assert(!SEHCodeSlotStack.empty() && "emitting EH code outside of __except");
1789  return Builder.CreateLoad(SEHCodeSlotStack.back());
1790 }
1791 
1793  // Abnormal termination is just the first parameter to the outlined finally
1794  // helper.
1795  auto AI = CurFn->arg_begin();
1796  return Builder.CreateZExt(&*AI, Int32Ty);
1797 }
1798 
1800  CodeGenFunction HelperCGF(CGM, /*suppressNewContext=*/true);
1801  if (const SEHFinallyStmt *Finally = S.getFinallyHandler()) {
1802  // Outline the finally block.
1803  llvm::Function *FinallyFunc =
1804  HelperCGF.GenerateSEHFinallyFunction(*this, *Finally);
1805 
1806  // Push a cleanup for __finally blocks.
1807  EHStack.pushCleanup<PerformSEHFinally>(NormalAndEHCleanup, FinallyFunc);
1808  return;
1809  }
1810 
1811  // Otherwise, we must have an __except block.
1812  const SEHExceptStmt *Except = S.getExceptHandler();
1813  assert(Except);
1814  EHCatchScope *CatchScope = EHStack.pushCatch(1);
1815  SEHCodeSlotStack.push_back(
1816  CreateMemTemp(getContext().IntTy, "__exception_code"));
1817 
1818  // If the filter is known to evaluate to 1, then we can use the clause
1819  // "catch i8* null". We can't do this on x86 because the filter has to save
1820  // the exception code.
1821  llvm::Constant *C =
1823  getContext().IntTy);
1824  if (CGM.getTarget().getTriple().getArch() != llvm::Triple::x86 && C &&
1825  C->isOneValue()) {
1826  CatchScope->setCatchAllHandler(0, createBasicBlock("__except"));
1827  return;
1828  }
1829 
1830  // In general, we have to emit an outlined filter function. Use the function
1831  // in place of the RTTI typeinfo global that C++ EH uses.
1832  llvm::Function *FilterFunc =
1833  HelperCGF.GenerateSEHFilterFunction(*this, *Except);
1834  llvm::Constant *OpaqueFunc =
1835  llvm::ConstantExpr::getBitCast(FilterFunc, Int8PtrTy);
1836  CatchScope->setHandler(0, OpaqueFunc, createBasicBlock("__except.ret"));
1837 }
1838 
1840  // Just pop the cleanup if it's a __finally block.
1841  if (S.getFinallyHandler()) {
1842  PopCleanupBlock();
1843  return;
1844  }
1845 
1846  // Otherwise, we must have an __except block.
1847  const SEHExceptStmt *Except = S.getExceptHandler();
1848  assert(Except && "__try must have __finally xor __except");
1849  EHCatchScope &CatchScope = cast<EHCatchScope>(*EHStack.begin());
1850 
1851  // Don't emit the __except block if the __try block lacked invokes.
1852  // TODO: Model unwind edges from instructions, either with iload / istore or
1853  // a try body function.
1854  if (!CatchScope.hasEHBranches()) {
1855  CatchScope.clearHandlerBlocks();
1856  EHStack.popCatch();
1857  SEHCodeSlotStack.pop_back();
1858  return;
1859  }
1860 
1861  // The fall-through block.
1862  llvm::BasicBlock *ContBB = createBasicBlock("__try.cont");
1863 
1864  // We just emitted the body of the __try; jump to the continue block.
1865  if (HaveInsertPoint())
1866  Builder.CreateBr(ContBB);
1867 
1868  // Check if our filter function returned true.
1869  emitCatchDispatchBlock(*this, CatchScope);
1870 
1871  // Grab the block before we pop the handler.
1872  llvm::BasicBlock *CatchPadBB = CatchScope.getHandler(0).Block;
1873  EHStack.popCatch();
1874 
1875  EmitBlockAfterUses(CatchPadBB);
1876 
1877  // __except blocks don't get outlined into funclets, so immediately do a
1878  // catchret.
1879  llvm::CatchPadInst *CPI =
1880  cast<llvm::CatchPadInst>(CatchPadBB->getFirstNonPHI());
1881  llvm::BasicBlock *ExceptBB = createBasicBlock("__except");
1882  Builder.CreateCatchRet(CPI, ExceptBB);
1883  EmitBlock(ExceptBB);
1884 
1885  // On Win64, the exception code is returned in EAX. Copy it into the slot.
1886  if (CGM.getTarget().getTriple().getArch() != llvm::Triple::x86) {
1887  llvm::Function *SEHCodeIntrin =
1888  CGM.getIntrinsic(llvm::Intrinsic::eh_exceptioncode);
1889  llvm::Value *Code = Builder.CreateCall(SEHCodeIntrin, {CPI});
1890  Builder.CreateStore(Code, SEHCodeSlotStack.back());
1891  }
1892 
1893  // Emit the __except body.
1894  EmitStmt(Except->getBlock());
1895 
1896  // End the lifetime of the exception code.
1897  SEHCodeSlotStack.pop_back();
1898 
1899  if (HaveInsertPoint())
1900  Builder.CreateBr(ContBB);
1901 
1902  EmitBlock(ContBB);
1903 }
1904 
1906  // If this code is reachable then emit a stop point (if generating
1907  // debug info). We have to do this ourselves because we are on the
1908  // "simple" statement path.
1909  if (HaveInsertPoint())
1910  EmitStopPoint(&S);
1911 
1912  // This must be a __leave from a __finally block, which we warn on and is UB.
1913  // Just emit unreachable.
1914  if (!isSEHTryScope()) {
1915  Builder.CreateUnreachable();
1916  Builder.ClearInsertionPoint();
1917  return;
1918  }
1919 
1920  EmitBranchThroughCleanup(*SEHTryEpilogueStack.back());
1921 }
virtual void mangleSEHFilterExpression(const NamedDecl *EnclosingDecl, raw_ostream &Out)=0
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:361
Represents a function declaration or definition.
Definition: Decl.h:1714
llvm::IntegerType * IntTy
int
EHScopeStack::stable_iterator getEnclosingEHScope() const
Definition: CGCleanup.h:138
Other implicit parameter.
Definition: Decl.h:1493
CompoundStmt * getBlock() const
Definition: Stmt.h:1974
void setCatchAllHandler(unsigned I, llvm::BasicBlock *Block)
Definition: CGCleanup.h:193
CanQualType VoidPtrTy
Definition: ASTContext.h:1014
A (possibly-)qualified type.
Definition: Type.h:654
void EmitSEHLeaveStmt(const SEHLeaveStmt &S)
bool usesFuncletPads() const
Does this personality use landingpads or the family of pad instructions designed to form funclets...
Definition: CGCleanup.h:633
Represents a version number in the form major[.minor[.subminor[.build]]].
Definition: VersionTuple.h:26
unsigned getNumExceptions() const
Definition: Type.h:3645
const Expr * getSubExpr() const
Definition: ExprCXX.h:1007
ConstStmtVisitor - This class implements a simple visitor for Stmt subclasses.
Definition: StmtVisitor.h:195
llvm::BasicBlock * getCachedEHDispatchBlock() const
Definition: CGCleanup.h:124
bool HaveInsertPoint() const
HaveInsertPoint - True if an insertion point is defined.
static const EHPersonality GNU_C_SJLJ
Definition: CGCleanup.h:616
void EmitCXXTryStmt(const CXXTryStmt &S)
Stmt - This represents one statement.
Definition: Stmt.h:66
CXXCatchStmt * getHandler(unsigned i)
Definition: StmtCXX.h:104
static const EHPersonality MSVC_C_specific_handler
Definition: CGCleanup.h:628
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:801
static const EHPersonality MSVC_CxxFrameHandler3
Definition: CGCleanup.h:629
tooling::Replacements cleanup(const FormatStyle &Style, StringRef Code, ArrayRef< tooling::Range > Ranges, StringRef FileName="<stdin>")
Clean up any erroneous/redundant code in the given Ranges in Code.
Definition: Format.cpp:2017
bool hasEHBranches() const
Definition: CGCleanup.h:132
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:86
Stmt * getHandlerBlock() const
Definition: StmtCXX.h:52
const Decl * CurCodeDecl
CurCodeDecl - This is the inner-most code context, which includes blocks.
static const EHPersonality GNU_C
Definition: CGCleanup.h:615
virtual void mangleSEHFinallyBlock(const NamedDecl *EnclosingDecl, raw_ostream &Out)=0
QualType getNonReferenceType() const
If Type is a reference type (e.g., const int&), returns the type that the reference refers to ("const...
Definition: Type.h:5977
Represents Objective-C&#39;s @throw statement.
Definition: StmtObjC.h:313
CanQualType LongTy
Definition: ASTContext.h:1006
static llvm::Constant * getUnexpectedFn(CodeGenModule &CGM)
Definition: CGException.cpp:42
void EmitSEHExceptionCodeSave(CodeGenFunction &ParentCGF, llvm::Value *ParentFP, llvm::Value *EntryEBP)
bool usesSEHTry() const
Indicates the function uses __try.
Definition: Decl.h:2101
static llvm::Constant * getPersonalityFn(CodeGenModule &CGM, const EHPersonality &Personality)
unsigned getNumFilters() const
Definition: CGCleanup.h:461
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
&#39;gcc&#39; is the Objective-C runtime shipped with GCC, implementing a fragile Objective-C ABI ...
Definition: ObjCRuntime.h:53
RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee, ReturnValueSlot ReturnValue, const CallArgList &Args, llvm::Instruction **callOrInvoke, SourceLocation Loc)
EmitCall - Generate a call of the given function, expecting the given result type, and using the given argument list which specifies both the LLVM arguments and the types they were derived from.
Definition: CGCall.cpp:3760
Represents a variable declaration or definition.
Definition: Decl.h:812
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6397
unsigned getNumHandlers() const
Definition: CGCleanup.h:189
llvm::Value * getPointer() const
Definition: Address.h:38
iterator begin() const
Returns an iterator pointing to the innermost EH scope.
Definition: CGCleanup.h:567
llvm::BasicBlock * EmitLandingPad()
Emits a landing pad for the current EH stack.
A protected scope for zero-cost EH handling.
Definition: CGCleanup.h:44
Defines the Objective-C statement AST node classes.
A C++ throw-expression (C++ [except.throw]).
Definition: ExprCXX.h:985
A scope which attempts to handle some, possibly all, types of exceptions.
Definition: CGCleanup.h:148
The collection of all-type qualifiers we support.
Definition: Type.h:153
void add(RValue rvalue, QualType type)
Definition: CGCall.h:285
A jump destination is an abstract label, branching to which may require a jump out through normal cle...
bool isNoexceptExceptionSpec(ExceptionSpecificationType ESpecType)
void popCatchScope()
popCatchScope - Pops the catch scope at the top of the EHScope stack, emitting any required code (oth...
const TargetInfo & getTarget() const
llvm::BasicBlock * getTerminateHandler()
getTerminateHandler - Return a handler (not a landing pad, just a catch handler) that just calls term...
&#39;macosx-fragile&#39; is the Apple-provided NeXT-derived runtime on Mac OS X platforms that use the fragil...
Definition: ObjCRuntime.h:40
const char * CatchallRethrowFn
Definition: CGCleanup.h:610
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:150
QualType getCaughtType() const
Definition: StmtCXX.cpp:20
SmallVector< Address, 1 > SEHCodeSlotStack
A stack of exception code slots.
static const EHPersonality GNU_CPlusPlus_SJLJ
Definition: CGCleanup.h:625
const FunctionDecl * CurSEHParent
llvm::CallInst * EmitRuntimeCall(llvm::Value *callee, const Twine &name="")
Denotes a cleanup that should run when a scope is exited using exceptional control flow (a throw stat...
Definition: EHScopeStack.h:81
static const EHPersonality & get(CodeGenModule &CGM, const FunctionDecl *FD)
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:50
Address getExceptionSlot()
Returns a pointer to the function&#39;s exception object and selector slot, which is assigned in every la...
void setFilter(unsigned i, llvm::Value *filterValue)
Definition: CGCleanup.h:463
class EHCatchScope * pushCatch(unsigned NumHandlers)
Push a set of catch handlers on the stack.
Definition: CGCleanup.cpp:251
bool isNeXTFamily() const
Is this runtime basically of the NeXT family of runtimes?
Definition: ObjCRuntime.h:135
static llvm::Constant * getFreeExceptionFn(CodeGenModule &CGM)
Definition: CGException.cpp:33
static llvm::Constant * getCatchAllValue(CodeGenFunction &CGF)
Returns the value to inject into a selector to indicate the presence of a catch-all.
void ExitSEHTryStmt(const SEHTryStmt &S)
QualType getExceptionType(unsigned i) const
Definition: Type.h:3646
iterator begin() const
Definition: CGCleanup.h:224
CharUnits getAlignment() const
Return the alignment of this pointer.
Definition: Address.h:67
child_range children()
Definition: Stmt.cpp:227
const Handler & getHandler(unsigned I) const
Definition: CGCleanup.h:209
static const EHPersonality GNUstep_ObjC
Definition: CGCleanup.h:621
llvm::Constant * getTerminateFn()
Get the declaration of std::terminate for the platform.
Definition: CGException.cpp:51
llvm::BasicBlock * getInvokeDestImpl()
llvm::Function * GenerateSEHFinallyFunction(CodeGenFunction &ParentCGF, const SEHFinallyStmt &Finally)
llvm::BasicBlock * createBasicBlock(const Twine &name="", llvm::Function *parent=nullptr, llvm::BasicBlock *before=nullptr)
createBasicBlock - Create an LLVM basic block.
Denotes a cleanup that should run when a scope is exited using normal control flow (falling off the e...
Definition: EHScopeStack.h:85
void ForceCleanup(std::initializer_list< llvm::Value **> ValuesToReload={})
Force the emission of cleanups now, instead of waiting until this object is destroyed.
Represents the body of a CapturedStmt, and serves as its DeclContext.
Definition: Decl.h:4015
llvm::AllocaInst * CreateTempAlloca(llvm::Type *Ty, const Twine &Name="tmp", llvm::Value *ArraySize=nullptr)
CreateTempAlloca - This creates an alloca and inserts it into the entry block if ArraySize is nullptr...
Definition: CGExpr.cpp:97
CanQualType UnsignedCharTy
Definition: ASTContext.h:1007
Represents the this expression in C++.
Definition: ExprCXX.h:945
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.
static ImplicitParamDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, ImplicitParamKind ParamKind)
Create implicit parameter.
Definition: Decl.cpp:4277
&#39;watchos&#39; is a variant of iOS for Apple&#39;s watchOS.
Definition: ObjCRuntime.h:49
bool isValid() const
Definition: Address.h:36
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3348
llvm::CallInst * EmitNounwindRuntimeCall(llvm::Value *callee, const Twine &name="")
static const EHPersonality MSVC_except_handler
Definition: CGCleanup.h:627
static llvm::Constant * getOpaquePersonalityFn(CodeGenModule &CGM, const EHPersonality &Personality)
SourceLocation getLocEnd() const LLVM_READONLY
Definition: Stmt.cpp:291
CatchTypeInfo Type
A type info value, or null (C++ null, not an LLVM null pointer) for a catch-all.
Definition: CGCleanup.h:158
void EmitCapturedLocals(CodeGenFunction &ParentCGF, const Stmt *OutlinedStmt, bool IsFilter)
Scan the outlined statement for captures from the parent function.
Expr - This represents one expression.
Definition: Expr.h:106
void enter(CodeGenFunction &CGF, const Stmt *Finally, llvm::Constant *beginCatchFn, llvm::Constant *endCatchFn, llvm::Constant *rethrowFn)
Enters a finally block for an implementation using zero-cost exceptions.
static bool PersonalityHasOnlyCXXUses(llvm::Constant *Fn)
Check whether a personality function could reasonably be swapped for a C++ personality function...
&#39;macosx&#39; is the Apple-provided NeXT-derived runtime on Mac OS X platforms that use the non-fragile AB...
Definition: ObjCRuntime.h:35
static Address invalid()
Definition: Address.h:35
Enters a new scope for capturing cleanups, all of which will be executed once the scope is exited...
const FunctionProtoType * T
llvm::Function * GenerateSEHFilterFunction(CodeGenFunction &ParentCGF, const SEHExceptStmt &Except)
Create a stub filter function that will ultimately hold the code of the filter expression.
static CGCallee forDirect(llvm::Constant *functionPtr, const CGCalleeInfo &abstractInfo=CGCalleeInfo())
Definition: CGCall.h:134
VarDecl * getExceptionDecl() const
Definition: StmtCXX.h:50
llvm::PointerType * getType() const
Return the type of the pointer value.
Definition: Address.h:44
void EmitSEHTryStmt(const SEHTryStmt &S)
llvm::BasicBlock * Block
The catch handler for this type.
Definition: CGCleanup.h:161
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:63
CXXTryStmt - A C++ try block, including all handlers.
Definition: StmtCXX.h:65
bool refersToEnclosingVariableOrCapture() const
Does this DeclRefExpr refer to an enclosing local or a captured variable?
Definition: Expr.h:1181
llvm::Value * getExceptionFromSlot()
Returns the contents of the function&#39;s exception object and selector slots.
static void emitCatchDispatchBlock(CodeGenFunction &CGF, EHCatchScope &catchScope)
Emit the structure of the dispatch block for the given catch scope.
llvm::LLVMContext & getLLVMContext()
const CGFunctionInfo & arrangeBuiltinFunctionCall(QualType resultType, const CallArgList &args)
Definition: CGCall.cpp:627
bool isSignedIntegerType() const
Return true if this is an integer type that is signed, according to C99 6.2.5p4 [char, signed char, short, int, long..], or an enum decl which has a signed representation.
Definition: Type.cpp:1807
QualType getType() const
Definition: Expr.h:128
static const EHPersonality & getObjCXXPersonality(const llvm::Triple &T, const LangOptions &L)
Determines the personality function to use when both C++ and Objective-C exceptions are being caught...
static const EHPersonality GNU_ObjCXX
Definition: CGCleanup.h:622
bool hasTerminate() const
Does this runtime provide an objc_terminate function?
Definition: ObjCRuntime.h:258
clang::ObjCRuntime ObjCRuntime
Definition: LangOptions.h:165
static const EHPersonality GNU_ObjC_SEH
Definition: CGCleanup.h:620
const TargetInfo & getTarget() const
ValueDecl * getDecl()
Definition: Expr.h:1057
&#39;gnustep&#39; is the modern non-fragile GNUstep runtime.
Definition: ObjCRuntime.h:56
const LangOptions & getLangOpts() const
ASTContext & getContext() const
llvm::StoreInst * CreateFlagStore(bool Value, llvm::Value *Addr)
Emit a store to an i1 flag variable.
Definition: CGBuilder.h:136
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:35
unsigned getBuiltinCallee() const
getBuiltinCallee - If this is a call to a builtin, return the builtin ID of the callee.
Definition: Expr.cpp:1280
llvm::BasicBlock * getEHDispatchBlock(EHScopeStack::stable_iterator scope)
The l-value was considered opaque, so the alignment was determined from a type.
static void emitFilterDispatchBlock(CodeGenFunction &CGF, EHFilterScope &filterScope)
Emit the dispatch block for a filter scope if necessary.
Address recoverAddrOfEscapedLocal(CodeGenFunction &ParentCGF, Address ParentVar, llvm::Value *ParentFP)
Recovers the address of a local in a parent function.
Enumerates target-specific builtins in their own namespaces within namespace clang.
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:142
static const EHPersonality & getObjCPersonality(const llvm::Triple &T, const LangOptions &L)
Encodes a location in the source.
void EnsureInsertPoint()
EnsureInsertPoint - Ensure that an insertion point is defined so that emitted IR has a place to go...
A saved depth on the scope stack.
Definition: EHScopeStack.h:107
unsigned getNumHandlers() const
Definition: StmtCXX.h:103
bool isVariablyModifiedType() const
Whether this type is a variably-modified type (C99 6.7.5).
Definition: Type.h:1945
&#39;objfw&#39; is the Objective-C runtime included in ObjFW
Definition: ObjCRuntime.h:59
llvm::BasicBlock * getUnreachableBlock()
llvm::CallSite EmitRuntimeCallOrInvoke(llvm::Value *callee, ArrayRef< llvm::Value *> args, const Twine &name="")
Emits a call or invoke instruction to the given runtime function.
Definition: CGCall.cpp:3719
Kind getKind() const
Definition: ObjCRuntime.h:77
MangleContext - Context for tracking state which persists across multiple calls to the C++ name mangl...
Definition: Mangle.h:43
void EmitStmt(const Stmt *S, ArrayRef< const Attr *> Attrs=None)
EmitStmt - Emit the code for the statement.
Definition: CGStmt.cpp:48
CanQualType VoidTy
Definition: ASTContext.h:997
bool isObjCObjectPointerType() const
Definition: Type.h:6125
An aligned address.
Definition: Address.h:25
llvm::BasicBlock * getEHResumeBlock(bool isCleanup)
void setCachedEHDispatchBlock(llvm::BasicBlock *block)
Definition: CGCleanup.h:128
llvm::Instruction * CurrentFuncletPad
llvm::Value * getFilter(unsigned i) const
Definition: CGCleanup.h:468
JumpDest getJumpDestInCurrentScope(llvm::BasicBlock *Target)
The given basic block lies in the current EH scope, but may be a target of a potentially scope-crossi...
const VersionTuple & getVersion() const
Definition: ObjCRuntime.h:78
void EmitStartEHSpec(const Decl *D)
EmitStartEHSpec - Emit the start of the exception spec.
The MS C++ ABI needs a pointer to RTTI data plus some flags to describe the type of a catch handler...
Definition: CGCleanup.h:38
static const EHPersonality & getCXXPersonality(const llvm::Triple &T, const LangOptions &L)
ExceptionSpecificationType getExceptionSpecType() const
Get the kind of exception specification on this function.
Definition: Type.h:3619
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
static const EHPersonality NeXT_ObjC
Definition: CGCleanup.h:623
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:356
llvm::BasicBlock * getMSVCDispatchBlock(EHScopeStack::stable_iterator scope)
CGFunctionInfo - Class to encapsulate the information about a function definition.
Kind getKind() const
Definition: CGCleanup.h:114
This class organizes the cross-function state that is used while generating LLVM code.
Dataflow Directional Tag Classes.
static ApplyDebugLocation CreateDefaultArtificial(CodeGenFunction &CGF, SourceLocation TemporaryLocation)
Apply TemporaryLocation if it is valid.
Definition: CGDebugInfo.h:679
static bool LandingPadHasOnlyCXXUses(llvm::LandingPadInst *LPI)
Check whether a landingpad instruction only uses C++ features.
static const EHPersonality GNU_CPlusPlus_SEH
Definition: CGCleanup.h:626
The basic abstraction for the target Objective-C runtime.
Definition: ObjCRuntime.h:28
static const EHPersonality GNU_ObjC
Definition: CGCleanup.h:618
static bool isNonEHScope(const EHScope &S)
Check whether this is a non-EH scope, i.e.
void EmitAnyExprToExn(const Expr *E, Address Addr)
llvm::LoadInst * CreateAlignedLoad(llvm::Value *Addr, CharUnits Align, const llvm::Twine &Name="")
Definition: CGBuilder.h:91
llvm::LoadInst * CreateLoad(Address Addr, const llvm::Twine &Name="")
Definition: CGBuilder.h:70
SEHExceptStmt * getExceptHandler() const
Returns 0 if not defined.
Definition: Stmt.cpp:948
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
llvm::Module & getModule() const
Represents a __leave statement.
Definition: Stmt.h:2035
&#39;ios&#39; is the Apple-provided NeXT-derived runtime on iOS or the iOS simulator; it is always non-fragil...
Definition: ObjCRuntime.h:45
llvm::BasicBlock * getTerminateFunclet()
getTerminateLandingPad - Return a cleanup funclet that just calls terminate.
CanThrowResult canThrow() const
Determine whether this function type has a non-throwing exception specification.
Definition: Type.cpp:2875
static const EHPersonality GNU_CPlusPlus
Definition: CGCleanup.h:624
llvm::LoadInst * CreateFlagLoad(llvm::Value *Addr, const llvm::Twine &Name="")
Emit a load from an i1 flag variable.
Definition: CGBuilder.h:129
llvm::StringRef getName() const
Return the IR name of the pointer value.
Definition: Address.h:62
static const EHPersonality GNU_ObjC_SJLJ
Definition: CGCleanup.h:619
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:32
ExceptionSpecificationType
The various types of exception specifications that exist in C++11.
void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false)
EmitBlock - Emit the given block.
Definition: CGStmt.cpp:445
void EnterCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock=false)
SEHFinallyStmt * getFinallyHandler() const
Definition: Stmt.cpp:952
static const EHPersonality & getSEHPersonalityMSVC(const llvm::Triple &T)
QualType getUnqualifiedType() const
Retrieve the unqualified variant of the given type, removing as little sugar as possible.
Definition: Type.h:5884
Expr * getFilterExpr() const
Definition: Stmt.h:1936
llvm::BasicBlock * getTerminateLandingPad()
getTerminateLandingPad - Return a landing pad that just calls terminate.
CXXCatchStmt - This represents a C++ catch block.
Definition: StmtCXX.h:29
llvm::Type * ConvertType(QualType T)
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:5831
static const EHPersonality GNU_C_SEH
Definition: CGCleanup.h:617
static const EHPersonality & getCPersonality(const llvm::Triple &T, const LangOptions &L)
The exceptions personality for a function.
Definition: CGCleanup.h:604
llvm::Constant * RTTI
Definition: CGCleanup.h:39
CompoundStmt * getTryBlock()
Definition: StmtCXX.h:96
llvm::Value * EmitSEHAbnormalTermination()
CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
Definition: Expr.h:2234
llvm::Constant * tryEmitAbstract(const Expr *E, QualType T)
Try to emit the result of the given expression as an abstract constant.
void EnterSEHTryStmt(const SEHTryStmt &S)
void startOutlinedSEHHelper(CodeGenFunction &ParentCGF, bool IsFilter, const Stmt *OutlinedStmt)
Arrange a function prototype that can be called by Windows exception handling personalities.
CGCXXABI & getCXXABI() const
CanQualType IntTy
Definition: ASTContext.h:1006
An exceptions scope which filters exceptions thrown through it.
Definition: CGCleanup.h:438
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:972
static RValue get(llvm::Value *V)
Definition: CGValue.h:86
void ExitCXXTryStmt(const CXXTryStmt &S, bool IsFnTryBlock=false)
void EmitBranchThroughCleanup(JumpDest Dest)
EmitBranchThroughCleanup - Emit a branch from the current insert block through the normal cleanup han...
Definition: CGCleanup.cpp:1034
void EmitEndEHSpec(const Decl *D)
EmitEndEHSpec - Emit the end of the exception spec.
static llvm::Constant * getCatchallRethrowFn(CodeGenModule &CGM, StringRef Name)
Definition: CGException.cpp:77
llvm::StoreInst * CreateAlignedStore(llvm::Value *Val, llvm::Value *Addr, CharUnits Align, bool IsVolatile=false)
Definition: CGBuilder.h:115
QualType getType() const
Definition: Decl.h:647
Information for lazily generating a cleanup.
Definition: EHScopeStack.h:147
A non-stable pointer into the scope stack.
Definition: CGCleanup.h:503
void EmitBlockAfterUses(llvm::BasicBlock *BB)
EmitBlockAfterUses - Emit the given block somewhere hopefully near its uses, and leave the insertion ...
Definition: CGStmt.cpp:482
static void emitCatchPadBlock(CodeGenFunction &CGF, EHCatchScope &CatchScope)
SourceLocation getLocStart() const LLVM_READONLY
Definition: Stmt.cpp:278
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:260
void PopCleanupBlock(bool FallThroughIsBranchThrough=false)
PopCleanupBlock - Will pop the cleanup entry on the stack and process all branch fixups.
Definition: CGCleanup.cpp:640
void setHandler(unsigned I, llvm::Constant *Type, llvm::BasicBlock *Block)
Definition: CGCleanup.h:197
CompoundStmt * getTryBlock() const
Definition: Stmt.h:2015
CompoundStmt * getBlock() const
Definition: Stmt.h:1940
void EmitCXXThrowExpr(const CXXThrowExpr *E, bool KeepInsertionPoint=true)
bool isLocalVarDeclOrParm() const
Similar to isLocalVarDecl but also includes parameters.
Definition: Decl.h:1111
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.
const llvm::Triple & getTriple() const