-//===-- WinEHPrepare - Prepare exception handling for code generation ---===//\r
-//\r
-// The LLVM Compiler Infrastructure\r
-//\r
-// This file is distributed under the University of Illinois Open Source\r
-// License. See LICENSE.TXT for details.\r
-//\r
-//===----------------------------------------------------------------------===//\r
-//\r
-// This pass lowers LLVM IR exception handling into something closer to what the\r
-// backend wants. It snifs the personality function to see which kind of\r
-// preparation is necessary. If the personality function uses the Itanium LSDA,\r
-// this pass delegates to the DWARF EH preparation pass.\r
-//\r
-//===----------------------------------------------------------------------===//\r
-\r
-#include "llvm/CodeGen/Passes.h"\r
-#include "llvm/Analysis/LibCallSemantics.h"\r
-#include "llvm/IR/Function.h"\r
-#include "llvm/IR/IRBuilder.h"\r
-#include "llvm/IR/Instructions.h"\r
-#include "llvm/IR/IntrinsicInst.h"\r
-#include "llvm/IR/Module.h"\r
-#include "llvm/IR/PatternMatch.h"\r
-#include "llvm/Pass.h"\r
-#include "llvm/Transforms/Utils/Cloning.h"\r
-#include "llvm/Transforms/Utils/Local.h"\r
-#include <memory>\r
-\r
-using namespace llvm;\r
-using namespace llvm::PatternMatch;\r
-\r
-#define DEBUG_TYPE "winehprepare"\r
-\r
-namespace {\r
-class WinEHPrepare : public FunctionPass {\r
- std::unique_ptr<FunctionPass> DwarfPrepare;\r
-\r
-public:\r
- static char ID; // Pass identification, replacement for typeid.\r
- WinEHPrepare(const TargetMachine *TM = nullptr)\r
- : FunctionPass(ID), DwarfPrepare(createDwarfEHPass(TM)) {}\r
-\r
- bool runOnFunction(Function &Fn) override;\r
-\r
- bool doFinalization(Module &M) override;\r
-\r
- void getAnalysisUsage(AnalysisUsage &AU) const override;\r
-\r
- const char *getPassName() const override {\r
- return "Windows exception handling preparation";\r
- }\r
-\r
-private:\r
- bool prepareCPPEHHandlers(Function &F,\r
- SmallVectorImpl<LandingPadInst *> &LPads);\r
- bool outlineCatchHandler(Function *SrcFn, Constant *SelectorType,\r
- LandingPadInst *LPad, StructType *EHDataStructTy);\r
-};\r
-\r
-class WinEHCatchDirector : public CloningDirector {\r
-public:\r
- WinEHCatchDirector(LandingPadInst *LPI, Value *Selector, Value *EHObj)\r
- : LPI(LPI), CurrentSelector(Selector->stripPointerCasts()), EHObj(EHObj),\r
- SelectorIDType(Type::getInt32Ty(LPI->getContext())),\r
- Int8PtrType(Type::getInt8PtrTy(LPI->getContext())) {}\r
- virtual ~WinEHCatchDirector() {}\r
-\r
- CloningAction handleInstruction(ValueToValueMapTy &VMap,\r
- const Instruction *Inst,\r
- BasicBlock *NewBB) override;\r
-\r
-private:\r
- LandingPadInst *LPI;\r
- Value *CurrentSelector;\r
- Value *EHObj;\r
- Type *SelectorIDType;\r
- Type *Int8PtrType;\r
-\r
- const Value *ExtractedEHPtr;\r
- const Value *ExtractedSelector;\r
- const Value *EHPtrStoreAddr;\r
- const Value *SelectorStoreAddr;\r
-};\r
-} // end anonymous namespace\r
-\r
-char WinEHPrepare::ID = 0;\r
-INITIALIZE_TM_PASS(WinEHPrepare, "winehprepare", "Prepare Windows exceptions",\r
- false, false)\r
-\r
-FunctionPass *llvm::createWinEHPass(const TargetMachine *TM) {\r
- return new WinEHPrepare(TM);\r
-}\r
-\r
-static bool isMSVCPersonality(EHPersonality Pers) {\r
- return Pers == EHPersonality::MSVC_Win64SEH ||\r
- Pers == EHPersonality::MSVC_CXX;\r
-}\r
-\r
-bool WinEHPrepare::runOnFunction(Function &Fn) {\r
- SmallVector<LandingPadInst *, 4> LPads;\r
- SmallVector<ResumeInst *, 4> Resumes;\r
- for (BasicBlock &BB : Fn) {\r
- if (auto *LP = BB.getLandingPadInst())\r
- LPads.push_back(LP);\r
- if (auto *Resume = dyn_cast<ResumeInst>(BB.getTerminator()))\r
- Resumes.push_back(Resume);\r
- }\r
-\r
- // No need to prepare functions that lack landing pads.\r
- if (LPads.empty())\r
- return false;\r
-\r
- // Classify the personality to see what kind of preparation we need.\r
- EHPersonality Pers = classifyEHPersonality(LPads.back()->getPersonalityFn());\r
-\r
- // Delegate through to the DWARF pass if this is unrecognized.\r
- if (!isMSVCPersonality(Pers))\r
- return DwarfPrepare->runOnFunction(Fn);\r
-\r
- // FIXME: This only returns true if the C++ EH handlers were outlined.\r
- // When that code is complete, it should always return whatever\r
- // prepareCPPEHHandlers returns.\r
- if (Pers == EHPersonality::MSVC_CXX && prepareCPPEHHandlers(Fn, LPads))\r
- return true;\r
-\r
- // FIXME: SEH Cleanups are unimplemented. Replace them with unreachable.\r
- if (Resumes.empty())\r
- return false;\r
-\r
- for (ResumeInst *Resume : Resumes) {\r
- IRBuilder<>(Resume).CreateUnreachable();\r
- Resume->eraseFromParent();\r
- }\r
-\r
- return true;\r
-}\r
-\r
-bool WinEHPrepare::doFinalization(Module &M) {\r
- return DwarfPrepare->doFinalization(M);\r
-}\r
-\r
-void WinEHPrepare::getAnalysisUsage(AnalysisUsage &AU) const {\r
- DwarfPrepare->getAnalysisUsage(AU);\r
-}\r
-\r
-bool WinEHPrepare::prepareCPPEHHandlers(\r
- Function &F, SmallVectorImpl<LandingPadInst *> &LPads) {\r
- // FIXME: Find all frame variable references in the handlers\r
- // to populate the structure elements.\r
- SmallVector<Type *, 2> AllocStructTys;\r
- AllocStructTys.push_back(Type::getInt32Ty(F.getContext())); // EH state\r
- AllocStructTys.push_back(Type::getInt8PtrTy(F.getContext())); // EH object\r
- StructType *EHDataStructTy =\r
- StructType::create(F.getContext(), AllocStructTys, \r
- "struct." + F.getName().str() + ".ehdata");\r
- bool HandlersOutlined = false;\r
-\r
- for (LandingPadInst *LPad : LPads) {\r
- // Look for evidence that this landingpad has already been processed.\r
- bool LPadHasActionList = false;\r
- BasicBlock *LPadBB = LPad->getParent();\r
- for (Instruction &Inst : LPadBB->getInstList()) {\r
- // FIXME: Make this an intrinsic.\r
- if (auto *Call = dyn_cast<CallInst>(&Inst))\r
- if (Call->getCalledFunction()->getName() == "llvm.eh.actions") {\r
- LPadHasActionList = true;\r
- break;\r
- }\r
- }\r
-\r
- // If we've already outlined the handlers for this landingpad,\r
- // there's nothing more to do here.\r
- if (LPadHasActionList)\r
- continue;\r
-\r
- for (unsigned Idx = 0, NumClauses = LPad->getNumClauses(); Idx < NumClauses;\r
- ++Idx) {\r
- if (LPad->isCatch(Idx))\r
- HandlersOutlined =\r
- outlineCatchHandler(&F, LPad->getClause(Idx), LPad, EHDataStructTy);\r
- } // End for each clause\r
- } // End for each landingpad\r
-\r
- return HandlersOutlined;\r
-}\r
-\r
-bool WinEHPrepare::outlineCatchHandler(Function *SrcFn, Constant *SelectorType,\r
- LandingPadInst *LPad,\r
- StructType *EHDataStructTy) {\r
- Module *M = SrcFn->getParent();\r
- LLVMContext &Context = M->getContext();\r
-\r
- // Create a new function to receive the handler contents.\r
- Type *Int8PtrType = Type::getInt8PtrTy(Context);\r
- std::vector<Type *> ArgTys;\r
- ArgTys.push_back(Int8PtrType);\r
- ArgTys.push_back(Int8PtrType);\r
- FunctionType *FnType = FunctionType::get(Int8PtrType, ArgTys, false);\r
- Function *CatchHandler = Function::Create(\r
- FnType, GlobalVariable::ExternalLinkage, SrcFn->getName() + ".catch", M);\r
-\r
- // Generate a standard prolog to setup the frame recovery structure.\r
- IRBuilder<> Builder(Context);\r
- BasicBlock *Entry = BasicBlock::Create(Context, "catch.entry");\r
- CatchHandler->getBasicBlockList().push_front(Entry);\r
- Builder.SetInsertPoint(Entry);\r
- Builder.SetCurrentDebugLocation(LPad->getDebugLoc());\r
-\r
- // The outlined handler will be called with the parent's frame pointer as\r
- // its second argument. To enable the handler to access variables from\r
- // the parent frame, we use that pointer to get locate a special block\r
- // of memory that was allocated using llvm.eh.allocateframe for this\r
- // purpose. During the outlining process we will determine which frame\r
- // variables are used in handlers and create a structure that maps these\r
- // variables into the frame allocation block.\r
- //\r
- // The frame allocation block also contains an exception state variable\r
- // used by the runtime and a pointer to the exception object pointer\r
- // which will be filled in by the runtime for use in the handler.\r
- Function *RecoverFrameFn =\r
- Intrinsic::getDeclaration(M, Intrinsic::framerecover);\r
- Value *RecoverArgs[] = {Builder.CreateBitCast(SrcFn, Int8PtrType, ""),\r
- &(CatchHandler->getArgumentList().back())};\r
- CallInst *EHAlloc =\r
- Builder.CreateCall(RecoverFrameFn, RecoverArgs, "eh.alloc");\r
- Value *EHData =\r
- Builder.CreateBitCast(EHAlloc, EHDataStructTy->getPointerTo(), "ehdata");\r
- Value *EHObjPtr =\r
- Builder.CreateConstInBoundsGEP2_32(EHData, 0, 1, "eh.obj.ptr");\r
-\r
- // This will give us a raw pointer to the exception object, which\r
- // corresponds to the formal parameter of the catch statement. If the\r
- // handler uses this object, we will generate code during the outlining\r
- // process to cast the pointer to the appropriate type and deference it\r
- // as necessary. The un-outlined landing pad code represents the\r
- // exception object as the result of the llvm.eh.begincatch call.\r
- Value *EHObj = Builder.CreateLoad(EHObjPtr, false, "eh.obj");\r
-\r
- ValueToValueMapTy VMap;\r
-\r
- // FIXME: Map other values referenced in the filter handler.\r
-\r
- WinEHCatchDirector Director(LPad, SelectorType, EHObj);\r
-\r
- SmallVector<ReturnInst *, 8> Returns;\r
- ClonedCodeInfo InlinedFunctionInfo;\r
-\r
- BasicBlock::iterator II = LPad;\r
-\r
- CloneAndPruneIntoFromInst(CatchHandler, SrcFn, ++II, VMap,\r
- /*ModuleLevelChanges=*/false, Returns, "",\r
- &InlinedFunctionInfo,\r
- SrcFn->getParent()->getDataLayout(), &Director);\r
-\r
- // Move all the instructions in the first cloned block into our entry block.\r
- BasicBlock *FirstClonedBB = std::next(Function::iterator(Entry));\r
- Entry->getInstList().splice(Entry->end(), FirstClonedBB->getInstList());\r
- FirstClonedBB->eraseFromParent();\r
-\r
- return true;\r
-}\r
-\r
-CloningDirector::CloningAction WinEHCatchDirector::handleInstruction(\r
- ValueToValueMapTy &VMap, const Instruction *Inst, BasicBlock *NewBB) {\r
- // Intercept instructions which extract values from the landing pad aggregate.\r
- if (auto *Extract = dyn_cast<ExtractValueInst>(Inst)) {\r
- if (Extract->getAggregateOperand() == LPI) {\r
- assert(Extract->getNumIndices() == 1 &&\r
- "Unexpected operation: extracting both landing pad values");\r
- assert((*(Extract->idx_begin()) == 0 || *(Extract->idx_begin()) == 1) &&\r
- "Unexpected operation: extracting an unknown landing pad element");\r
-\r
- if (*(Extract->idx_begin()) == 0) {\r
- // Element 0 doesn't directly corresponds to anything in the WinEH scheme.\r
- // It will be stored to a memory location, then later loaded and finally\r
- // the loaded value will be used as the argument to an llvm.eh.begincatch\r
- // call. We're tracking it here so that we can skip the store and load.\r
- ExtractedEHPtr = Inst;\r
- } else {\r
- // Element 1 corresponds to the filter selector. We'll map it to 1 for\r
- // matching purposes, but it will also probably be stored to memory and\r
- // reloaded, so we need to track the instuction so that we can map the\r
- // loaded value too.\r
- VMap[Inst] = ConstantInt::get(SelectorIDType, 1);\r
- ExtractedSelector = Inst;\r
- }\r
-\r
- // Tell the caller not to clone this instruction.\r
- return CloningDirector::SkipInstruction;\r
- }\r
- // Other extract value instructions just get cloned.\r
- return CloningDirector::CloneInstruction;\r
- }\r
-\r
- if (auto *Store = dyn_cast<StoreInst>(Inst)) {\r
- // Look for and suppress stores of the extracted landingpad values.\r
- const Value *StoredValue = Store->getValueOperand();\r
- if (StoredValue == ExtractedEHPtr) {\r
- EHPtrStoreAddr = Store->getPointerOperand();\r
- return CloningDirector::SkipInstruction;\r
- }\r
- if (StoredValue == ExtractedSelector) {\r
- SelectorStoreAddr = Store->getPointerOperand();\r
- return CloningDirector::SkipInstruction;\r
- }\r
-\r
- // Any other store just gets cloned.\r
- return CloningDirector::CloneInstruction;\r
- }\r
-\r
- if (auto *Load = dyn_cast<LoadInst>(Inst)) {\r
- // Look for loads of (previously suppressed) landingpad values.\r
- // The EHPtr load can be ignored (it should only be used as\r
- // an argument to llvm.eh.begincatch), but the selector value\r
- // needs to be mapped to a constant value of 1 to be used to\r
- // simplify the branching to always flow to the current handler.\r
- const Value *LoadAddr = Load->getPointerOperand();\r
- if (LoadAddr == EHPtrStoreAddr) {\r
- VMap[Inst] = UndefValue::get(Int8PtrType);\r
- return CloningDirector::SkipInstruction;\r
- }\r
- if (LoadAddr == SelectorStoreAddr) {\r
- VMap[Inst] = ConstantInt::get(SelectorIDType, 1);\r
- return CloningDirector::SkipInstruction;\r
- }\r
-\r
- // Any other loads just get cloned.\r
- return CloningDirector::CloneInstruction;\r
- }\r
-\r
- if (match(Inst, m_Intrinsic<Intrinsic::eh_begincatch>())) {\r
- // The argument to the call is some form of the first element of the\r
- // landingpad aggregate value, but that doesn't matter. It isn't used\r
- // here.\r
- // The return value of this instruction, however, is used to access the\r
- // EH object pointer. We have generated an instruction to get that value\r
- // from the EH alloc block, so we can just map to that here.\r
- VMap[Inst] = EHObj;\r
- return CloningDirector::SkipInstruction;\r
- }\r
- if (match(Inst, m_Intrinsic<Intrinsic::eh_endcatch>())) {\r
- auto *IntrinCall = dyn_cast<IntrinsicInst>(Inst);\r
- // It might be interesting to track whether or not we are inside a catch\r
- // function, but that might make the algorithm more brittle than it needs\r
- // to be.\r
-\r
- // The end catch call can occur in one of two places: either in a\r
- // landingpad\r
- // block that is part of the catch handlers exception mechanism, or at the\r
- // end of the catch block. If it occurs in a landing pad, we must skip it\r
- // and continue so that the landing pad gets cloned.\r
- // FIXME: This case isn't fully supported yet and shouldn't turn up in any\r
- // of the test cases until it is.\r
- if (IntrinCall->getParent()->isLandingPad())\r
- return CloningDirector::SkipInstruction;\r
-\r
- // If an end catch occurs anywhere else the next instruction should be an\r
- // unconditional branch instruction that we want to replace with a return\r
- // to the the address of the branch target.\r
- const BasicBlock *EndCatchBB = IntrinCall->getParent();\r
- const TerminatorInst *Terminator = EndCatchBB->getTerminator();\r
- const BranchInst *Branch = dyn_cast<BranchInst>(Terminator);\r
- assert(Branch && Branch->isUnconditional());\r
- assert(std::next(BasicBlock::const_iterator(IntrinCall)) ==\r
- BasicBlock::const_iterator(Branch));\r
-\r
- ReturnInst::Create(NewBB->getContext(),\r
- BlockAddress::get(Branch->getSuccessor(0)), NewBB);\r
-\r
- // We just added a terminator to the cloned block.\r
- // Tell the caller to stop processing the current basic block so that\r
- // the branch instruction will be skipped.\r
- return CloningDirector::StopCloningBB;\r
- }\r
- if (match(Inst, m_Intrinsic<Intrinsic::eh_typeid_for>())) {\r
- auto *IntrinCall = dyn_cast<IntrinsicInst>(Inst);\r
- Value *Selector = IntrinCall->getArgOperand(0)->stripPointerCasts();\r
- // This causes a replacement that will collapse the landing pad CFG based\r
- // on the filter function we intend to match.\r
- if (Selector == CurrentSelector)\r
- VMap[Inst] = ConstantInt::get(SelectorIDType, 1);\r
- else\r
- VMap[Inst] = ConstantInt::get(SelectorIDType, 0);\r
- // Tell the caller not to clone this instruction.\r
- return CloningDirector::SkipInstruction;\r
- }\r
-\r
- // Continue with the default cloning behavior.\r
- return CloningDirector::CloneInstruction;\r
-}\r
+//===-- WinEHPrepare - Prepare exception handling for code generation ---===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass lowers LLVM IR exception handling into something closer to what the
+// backend wants. It snifs the personality function to see which kind of
+// preparation is necessary. If the personality function uses the Itanium LSDA,
+// this pass delegates to the DWARF EH preparation pass.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/Analysis/LibCallSemantics.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/PatternMatch.h"
+#include "llvm/Pass.h"
+#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/Transforms/Utils/Local.h"
+#include <memory>
+
+using namespace llvm;
+using namespace llvm::PatternMatch;
+
+#define DEBUG_TYPE "winehprepare"
+
+namespace {
+class WinEHPrepare : public FunctionPass {
+ std::unique_ptr<FunctionPass> DwarfPrepare;
+
+public:
+ static char ID; // Pass identification, replacement for typeid.
+ WinEHPrepare(const TargetMachine *TM = nullptr)
+ : FunctionPass(ID), DwarfPrepare(createDwarfEHPass(TM)) {}
+
+ bool runOnFunction(Function &Fn) override;
+
+ bool doFinalization(Module &M) override;
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+ const char *getPassName() const override {
+ return "Windows exception handling preparation";
+ }
+
+private:
+ bool prepareCPPEHHandlers(Function &F,
+ SmallVectorImpl<LandingPadInst *> &LPads);
+ bool outlineCatchHandler(Function *SrcFn, Constant *SelectorType,
+ LandingPadInst *LPad, StructType *EHDataStructTy);
+};
+
+class WinEHCatchDirector : public CloningDirector {
+public:
+ WinEHCatchDirector(LandingPadInst *LPI, Value *Selector, Value *EHObj)
+ : LPI(LPI), CurrentSelector(Selector->stripPointerCasts()), EHObj(EHObj),
+ SelectorIDType(Type::getInt32Ty(LPI->getContext())),
+ Int8PtrType(Type::getInt8PtrTy(LPI->getContext())) {}
+ virtual ~WinEHCatchDirector() {}
+
+ CloningAction handleInstruction(ValueToValueMapTy &VMap,
+ const Instruction *Inst,
+ BasicBlock *NewBB) override;
+
+private:
+ LandingPadInst *LPI;
+ Value *CurrentSelector;
+ Value *EHObj;
+ Type *SelectorIDType;
+ Type *Int8PtrType;
+
+ const Value *ExtractedEHPtr;
+ const Value *ExtractedSelector;
+ const Value *EHPtrStoreAddr;
+ const Value *SelectorStoreAddr;
+};
+} // end anonymous namespace
+
+char WinEHPrepare::ID = 0;
+INITIALIZE_TM_PASS(WinEHPrepare, "winehprepare", "Prepare Windows exceptions",
+ false, false)
+
+FunctionPass *llvm::createWinEHPass(const TargetMachine *TM) {
+ return new WinEHPrepare(TM);
+}
+
+static bool isMSVCPersonality(EHPersonality Pers) {
+ return Pers == EHPersonality::MSVC_Win64SEH ||
+ Pers == EHPersonality::MSVC_CXX;
+}
+
+bool WinEHPrepare::runOnFunction(Function &Fn) {
+ SmallVector<LandingPadInst *, 4> LPads;
+ SmallVector<ResumeInst *, 4> Resumes;
+ for (BasicBlock &BB : Fn) {
+ if (auto *LP = BB.getLandingPadInst())
+ LPads.push_back(LP);
+ if (auto *Resume = dyn_cast<ResumeInst>(BB.getTerminator()))
+ Resumes.push_back(Resume);
+ }
+
+ // No need to prepare functions that lack landing pads.
+ if (LPads.empty())
+ return false;
+
+ // Classify the personality to see what kind of preparation we need.
+ EHPersonality Pers = classifyEHPersonality(LPads.back()->getPersonalityFn());
+
+ // Delegate through to the DWARF pass if this is unrecognized.
+ if (!isMSVCPersonality(Pers))
+ return DwarfPrepare->runOnFunction(Fn);
+
+ // FIXME: This only returns true if the C++ EH handlers were outlined.
+ // When that code is complete, it should always return whatever
+ // prepareCPPEHHandlers returns.
+ if (Pers == EHPersonality::MSVC_CXX && prepareCPPEHHandlers(Fn, LPads))
+ return true;
+
+ // FIXME: SEH Cleanups are unimplemented. Replace them with unreachable.
+ if (Resumes.empty())
+ return false;
+
+ for (ResumeInst *Resume : Resumes) {
+ IRBuilder<>(Resume).CreateUnreachable();
+ Resume->eraseFromParent();
+ }
+
+ return true;
+}
+
+bool WinEHPrepare::doFinalization(Module &M) {
+ return DwarfPrepare->doFinalization(M);
+}
+
+void WinEHPrepare::getAnalysisUsage(AnalysisUsage &AU) const {
+ DwarfPrepare->getAnalysisUsage(AU);
+}
+
+bool WinEHPrepare::prepareCPPEHHandlers(
+ Function &F, SmallVectorImpl<LandingPadInst *> &LPads) {
+ // FIXME: Find all frame variable references in the handlers
+ // to populate the structure elements.
+ SmallVector<Type *, 2> AllocStructTys;
+ AllocStructTys.push_back(Type::getInt32Ty(F.getContext())); // EH state
+ AllocStructTys.push_back(Type::getInt8PtrTy(F.getContext())); // EH object
+ StructType *EHDataStructTy =
+ StructType::create(F.getContext(), AllocStructTys,
+ "struct." + F.getName().str() + ".ehdata");
+ bool HandlersOutlined = false;
+
+ for (LandingPadInst *LPad : LPads) {
+ // Look for evidence that this landingpad has already been processed.
+ bool LPadHasActionList = false;
+ BasicBlock *LPadBB = LPad->getParent();
+ for (Instruction &Inst : LPadBB->getInstList()) {
+ // FIXME: Make this an intrinsic.
+ if (auto *Call = dyn_cast<CallInst>(&Inst))
+ if (Call->getCalledFunction()->getName() == "llvm.eh.actions") {
+ LPadHasActionList = true;
+ break;
+ }
+ }
+
+ // If we've already outlined the handlers for this landingpad,
+ // there's nothing more to do here.
+ if (LPadHasActionList)
+ continue;
+
+ for (unsigned Idx = 0, NumClauses = LPad->getNumClauses(); Idx < NumClauses;
+ ++Idx) {
+ if (LPad->isCatch(Idx))
+ HandlersOutlined =
+ outlineCatchHandler(&F, LPad->getClause(Idx), LPad, EHDataStructTy);
+ } // End for each clause
+ } // End for each landingpad
+
+ return HandlersOutlined;
+}
+
+bool WinEHPrepare::outlineCatchHandler(Function *SrcFn, Constant *SelectorType,
+ LandingPadInst *LPad,
+ StructType *EHDataStructTy) {
+ Module *M = SrcFn->getParent();
+ LLVMContext &Context = M->getContext();
+
+ // Create a new function to receive the handler contents.
+ Type *Int8PtrType = Type::getInt8PtrTy(Context);
+ std::vector<Type *> ArgTys;
+ ArgTys.push_back(Int8PtrType);
+ ArgTys.push_back(Int8PtrType);
+ FunctionType *FnType = FunctionType::get(Int8PtrType, ArgTys, false);
+ Function *CatchHandler = Function::Create(
+ FnType, GlobalVariable::ExternalLinkage, SrcFn->getName() + ".catch", M);
+
+ // Generate a standard prolog to setup the frame recovery structure.
+ IRBuilder<> Builder(Context);
+ BasicBlock *Entry = BasicBlock::Create(Context, "catch.entry");
+ CatchHandler->getBasicBlockList().push_front(Entry);
+ Builder.SetInsertPoint(Entry);
+ Builder.SetCurrentDebugLocation(LPad->getDebugLoc());
+
+ // The outlined handler will be called with the parent's frame pointer as
+ // its second argument. To enable the handler to access variables from
+ // the parent frame, we use that pointer to get locate a special block
+ // of memory that was allocated using llvm.eh.allocateframe for this
+ // purpose. During the outlining process we will determine which frame
+ // variables are used in handlers and create a structure that maps these
+ // variables into the frame allocation block.
+ //
+ // The frame allocation block also contains an exception state variable
+ // used by the runtime and a pointer to the exception object pointer
+ // which will be filled in by the runtime for use in the handler.
+ Function *RecoverFrameFn =
+ Intrinsic::getDeclaration(M, Intrinsic::framerecover);
+ Value *RecoverArgs[] = {Builder.CreateBitCast(SrcFn, Int8PtrType, ""),
+ &(CatchHandler->getArgumentList().back())};
+ CallInst *EHAlloc =
+ Builder.CreateCall(RecoverFrameFn, RecoverArgs, "eh.alloc");
+ Value *EHData =
+ Builder.CreateBitCast(EHAlloc, EHDataStructTy->getPointerTo(), "ehdata");
+ Value *EHObjPtr =
+ Builder.CreateConstInBoundsGEP2_32(EHData, 0, 1, "eh.obj.ptr");
+
+ // This will give us a raw pointer to the exception object, which
+ // corresponds to the formal parameter of the catch statement. If the
+ // handler uses this object, we will generate code during the outlining
+ // process to cast the pointer to the appropriate type and deference it
+ // as necessary. The un-outlined landing pad code represents the
+ // exception object as the result of the llvm.eh.begincatch call.
+ Value *EHObj = Builder.CreateLoad(EHObjPtr, false, "eh.obj");
+
+ ValueToValueMapTy VMap;
+
+ // FIXME: Map other values referenced in the filter handler.
+
+ WinEHCatchDirector Director(LPad, SelectorType, EHObj);
+
+ SmallVector<ReturnInst *, 8> Returns;
+ ClonedCodeInfo InlinedFunctionInfo;
+
+ BasicBlock::iterator II = LPad;
+
+ CloneAndPruneIntoFromInst(CatchHandler, SrcFn, ++II, VMap,
+ /*ModuleLevelChanges=*/false, Returns, "",
+ &InlinedFunctionInfo,
+ SrcFn->getParent()->getDataLayout(), &Director);
+
+ // Move all the instructions in the first cloned block into our entry block.
+ BasicBlock *FirstClonedBB = std::next(Function::iterator(Entry));
+ Entry->getInstList().splice(Entry->end(), FirstClonedBB->getInstList());
+ FirstClonedBB->eraseFromParent();
+
+ return true;
+}
+
+CloningDirector::CloningAction WinEHCatchDirector::handleInstruction(
+ ValueToValueMapTy &VMap, const Instruction *Inst, BasicBlock *NewBB) {
+ // Intercept instructions which extract values from the landing pad aggregate.
+ if (auto *Extract = dyn_cast<ExtractValueInst>(Inst)) {
+ if (Extract->getAggregateOperand() == LPI) {
+ assert(Extract->getNumIndices() == 1 &&
+ "Unexpected operation: extracting both landing pad values");
+ assert((*(Extract->idx_begin()) == 0 || *(Extract->idx_begin()) == 1) &&
+ "Unexpected operation: extracting an unknown landing pad element");
+
+ if (*(Extract->idx_begin()) == 0) {
+ // Element 0 doesn't directly corresponds to anything in the WinEH scheme.
+ // It will be stored to a memory location, then later loaded and finally
+ // the loaded value will be used as the argument to an llvm.eh.begincatch
+ // call. We're tracking it here so that we can skip the store and load.
+ ExtractedEHPtr = Inst;
+ } else {
+ // Element 1 corresponds to the filter selector. We'll map it to 1 for
+ // matching purposes, but it will also probably be stored to memory and
+ // reloaded, so we need to track the instuction so that we can map the
+ // loaded value too.
+ VMap[Inst] = ConstantInt::get(SelectorIDType, 1);
+ ExtractedSelector = Inst;
+ }
+
+ // Tell the caller not to clone this instruction.
+ return CloningDirector::SkipInstruction;
+ }
+ // Other extract value instructions just get cloned.
+ return CloningDirector::CloneInstruction;
+ }
+
+ if (auto *Store = dyn_cast<StoreInst>(Inst)) {
+ // Look for and suppress stores of the extracted landingpad values.
+ const Value *StoredValue = Store->getValueOperand();
+ if (StoredValue == ExtractedEHPtr) {
+ EHPtrStoreAddr = Store->getPointerOperand();
+ return CloningDirector::SkipInstruction;
+ }
+ if (StoredValue == ExtractedSelector) {
+ SelectorStoreAddr = Store->getPointerOperand();
+ return CloningDirector::SkipInstruction;
+ }
+
+ // Any other store just gets cloned.
+ return CloningDirector::CloneInstruction;
+ }
+
+ if (auto *Load = dyn_cast<LoadInst>(Inst)) {
+ // Look for loads of (previously suppressed) landingpad values.
+ // The EHPtr load can be ignored (it should only be used as
+ // an argument to llvm.eh.begincatch), but the selector value
+ // needs to be mapped to a constant value of 1 to be used to
+ // simplify the branching to always flow to the current handler.
+ const Value *LoadAddr = Load->getPointerOperand();
+ if (LoadAddr == EHPtrStoreAddr) {
+ VMap[Inst] = UndefValue::get(Int8PtrType);
+ return CloningDirector::SkipInstruction;
+ }
+ if (LoadAddr == SelectorStoreAddr) {
+ VMap[Inst] = ConstantInt::get(SelectorIDType, 1);
+ return CloningDirector::SkipInstruction;
+ }
+
+ // Any other loads just get cloned.
+ return CloningDirector::CloneInstruction;
+ }
+
+ if (match(Inst, m_Intrinsic<Intrinsic::eh_begincatch>())) {
+ // The argument to the call is some form of the first element of the
+ // landingpad aggregate value, but that doesn't matter. It isn't used
+ // here.
+ // The return value of this instruction, however, is used to access the
+ // EH object pointer. We have generated an instruction to get that value
+ // from the EH alloc block, so we can just map to that here.
+ VMap[Inst] = EHObj;
+ return CloningDirector::SkipInstruction;
+ }
+ if (match(Inst, m_Intrinsic<Intrinsic::eh_endcatch>())) {
+ auto *IntrinCall = dyn_cast<IntrinsicInst>(Inst);
+ // It might be interesting to track whether or not we are inside a catch
+ // function, but that might make the algorithm more brittle than it needs
+ // to be.
+
+ // The end catch call can occur in one of two places: either in a
+ // landingpad
+ // block that is part of the catch handlers exception mechanism, or at the
+ // end of the catch block. If it occurs in a landing pad, we must skip it
+ // and continue so that the landing pad gets cloned.
+ // FIXME: This case isn't fully supported yet and shouldn't turn up in any
+ // of the test cases until it is.
+ if (IntrinCall->getParent()->isLandingPad())
+ return CloningDirector::SkipInstruction;
+
+ // If an end catch occurs anywhere else the next instruction should be an
+ // unconditional branch instruction that we want to replace with a return
+ // to the the address of the branch target.
+ const BasicBlock *EndCatchBB = IntrinCall->getParent();
+ const TerminatorInst *Terminator = EndCatchBB->getTerminator();
+ const BranchInst *Branch = dyn_cast<BranchInst>(Terminator);
+ assert(Branch && Branch->isUnconditional());
+ assert(std::next(BasicBlock::const_iterator(IntrinCall)) ==
+ BasicBlock::const_iterator(Branch));
+
+ ReturnInst::Create(NewBB->getContext(),
+ BlockAddress::get(Branch->getSuccessor(0)), NewBB);
+
+ // We just added a terminator to the cloned block.
+ // Tell the caller to stop processing the current basic block so that
+ // the branch instruction will be skipped.
+ return CloningDirector::StopCloningBB;
+ }
+ if (match(Inst, m_Intrinsic<Intrinsic::eh_typeid_for>())) {
+ auto *IntrinCall = dyn_cast<IntrinsicInst>(Inst);
+ Value *Selector = IntrinCall->getArgOperand(0)->stripPointerCasts();
+ // This causes a replacement that will collapse the landing pad CFG based
+ // on the filter function we intend to match.
+ if (Selector == CurrentSelector)
+ VMap[Inst] = ConstantInt::get(SelectorIDType, 1);
+ else
+ VMap[Inst] = ConstantInt::get(SelectorIDType, 0);
+ // Tell the caller not to clone this instruction.
+ return CloningDirector::SkipInstruction;
+ }
+
+ // Continue with the default cloning behavior.
+ return CloningDirector::CloneInstruction;
+}
-; RUN: opt -mtriple=x86_64-pc-windows-msvc -winehprepare -S -o - < %s | FileCheck %s\r
-\r
-; This test is based on the following code:\r
-;\r
-; void test()\r
-; {\r
-; try {\r
-; may_throw();\r
-; } catch (int) {\r
-; handle_int();\r
-; }\r
-; }\r
-;\r
-; Parts of the IR have been hand-edited to simplify the test case.\r
-; The full IR will be restored when Windows C++ EH support is complete.\r
-\r
-;ModuleID = 'cppeh-catch-scalar.cpp'\r
-target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"\r
-target triple = "x86_64-pc-windows-msvc"\r
-\r
-@_ZTIi = external constant i8*\r
-\r
-; Function Attrs: uwtable\r
-define void @_Z4testv() #0 {\r
-entry:\r
- %exn.slot = alloca i8*\r
- %ehselector.slot = alloca i32\r
- invoke void @_Z9may_throwv()\r
- to label %invoke.cont unwind label %lpad\r
-\r
-invoke.cont: ; preds = %entry\r
- br label %try.cont\r
-\r
-lpad: ; preds = %entry\r
- %0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*)\r
- catch i8* bitcast (i8** @_ZTIi to i8*)\r
- %1 = extractvalue { i8*, i32 } %0, 0\r
- store i8* %1, i8** %exn.slot\r
- %2 = extractvalue { i8*, i32 } %0, 1\r
- store i32 %2, i32* %ehselector.slot\r
- br label %catch.dispatch\r
-\r
-catch.dispatch: ; preds = %lpad\r
- %sel = load i32* %ehselector.slot\r
- %3 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*)) #3\r
- %matches = icmp eq i32 %sel, %3\r
- br i1 %matches, label %catch, label %eh.resume\r
-\r
-catch: ; preds = %catch.dispatch\r
- %exn11 = load i8** %exn.slot\r
- %4 = call i8* @llvm.eh.begincatch(i8* %exn11) #3\r
- %5 = bitcast i8* %4 to i32*\r
- call void @_Z10handle_intv()\r
- br label %invoke.cont2\r
-\r
-invoke.cont2: ; preds = %catch\r
- call void @llvm.eh.endcatch() #3\r
- br label %try.cont\r
-\r
-try.cont: ; preds = %invoke.cont2, %invoke.cont\r
- ret void\r
-\r
-eh.resume: ; preds = %catch.dispatch\r
- %exn3 = load i8** %exn.slot\r
- %sel4 = load i32* %ehselector.slot\r
- %lpad.val = insertvalue { i8*, i32 } undef, i8* %exn3, 0\r
- %lpad.val5 = insertvalue { i8*, i32 } %lpad.val, i32 %sel4, 1\r
- resume { i8*, i32 } %lpad.val5\r
-}\r
-\r
-; CHECK: define i8* @_Z4testv.catch(i8*, i8*) {\r
-; CHECK: catch.entry:\r
-; CHECK: %eh.alloc = call i8* @llvm.framerecover(i8* bitcast (void ()* @_Z4testv to i8*), i8* %1)\r
-; CHECK: %ehdata = bitcast i8* %eh.alloc to %struct._Z4testv.ehdata*\r
-; CHECK: %eh.obj.ptr = getelementptr inbounds %struct._Z4testv.ehdata* %ehdata, i32 0, i32 1\r
-; CHECK: %eh.obj = load i8** %eh.obj.ptr\r
-; CHECK: %2 = bitcast i8* %eh.obj to i32*\r
-; CHECK: call void @_Z10handle_intv()\r
-; CHECK: ret i8* blockaddress(@_Z4testv, %try.cont)\r
-; CHECK: }\r
-\r
-declare void @_Z9may_throwv() #1\r
-\r
-declare i32 @__CxxFrameHandler3(...)\r
-\r
-; Function Attrs: nounwind readnone\r
-declare i32 @llvm.eh.typeid.for(i8*) #2\r
-\r
-declare i8* @llvm.eh.begincatch(i8*)\r
-\r
-declare void @llvm.eh.endcatch()\r
-\r
-declare void @_Z10handle_intv() #1\r
-\r
-attributes #0 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }\r
-attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }\r
-attributes #2 = { nounwind readnone }\r
-attributes #3 = { nounwind }\r
-\r
-!llvm.ident = !{!0}\r
-\r
-!0 = !{!"clang version 3.7.0 (trunk 227474) (llvm/trunk 227508)"}\r
+; RUN: opt -mtriple=x86_64-pc-windows-msvc -winehprepare -S -o - < %s | FileCheck %s
+
+; This test is based on the following code:
+;
+; void test()
+; {
+; try {
+; may_throw();
+; } catch (int) {
+; handle_int();
+; }
+; }
+;
+; Parts of the IR have been hand-edited to simplify the test case.
+; The full IR will be restored when Windows C++ EH support is complete.
+
+;ModuleID = 'cppeh-catch-scalar.cpp'
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc"
+
+@_ZTIi = external constant i8*
+
+; Function Attrs: uwtable
+define void @_Z4testv() #0 {
+entry:
+ %exn.slot = alloca i8*
+ %ehselector.slot = alloca i32
+ invoke void @_Z9may_throwv()
+ to label %invoke.cont unwind label %lpad
+
+invoke.cont: ; preds = %entry
+ br label %try.cont
+
+lpad: ; preds = %entry
+ %0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*)
+ catch i8* bitcast (i8** @_ZTIi to i8*)
+ %1 = extractvalue { i8*, i32 } %0, 0
+ store i8* %1, i8** %exn.slot
+ %2 = extractvalue { i8*, i32 } %0, 1
+ store i32 %2, i32* %ehselector.slot
+ br label %catch.dispatch
+
+catch.dispatch: ; preds = %lpad
+ %sel = load i32* %ehselector.slot
+ %3 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIi to i8*)) #3
+ %matches = icmp eq i32 %sel, %3
+ br i1 %matches, label %catch, label %eh.resume
+
+catch: ; preds = %catch.dispatch
+ %exn11 = load i8** %exn.slot
+ %4 = call i8* @llvm.eh.begincatch(i8* %exn11) #3
+ %5 = bitcast i8* %4 to i32*
+ call void @_Z10handle_intv()
+ br label %invoke.cont2
+
+invoke.cont2: ; preds = %catch
+ call void @llvm.eh.endcatch() #3
+ br label %try.cont
+
+try.cont: ; preds = %invoke.cont2, %invoke.cont
+ ret void
+
+eh.resume: ; preds = %catch.dispatch
+ %exn3 = load i8** %exn.slot
+ %sel4 = load i32* %ehselector.slot
+ %lpad.val = insertvalue { i8*, i32 } undef, i8* %exn3, 0
+ %lpad.val5 = insertvalue { i8*, i32 } %lpad.val, i32 %sel4, 1
+ resume { i8*, i32 } %lpad.val5
+}
+
+; CHECK: define i8* @_Z4testv.catch(i8*, i8*) {
+; CHECK: catch.entry:
+; CHECK: %eh.alloc = call i8* @llvm.framerecover(i8* bitcast (void ()* @_Z4testv to i8*), i8* %1)
+; CHECK: %ehdata = bitcast i8* %eh.alloc to %struct._Z4testv.ehdata*
+; CHECK: %eh.obj.ptr = getelementptr inbounds %struct._Z4testv.ehdata* %ehdata, i32 0, i32 1
+; CHECK: %eh.obj = load i8** %eh.obj.ptr
+; CHECK: %2 = bitcast i8* %eh.obj to i32*
+; CHECK: call void @_Z10handle_intv()
+; CHECK: ret i8* blockaddress(@_Z4testv, %try.cont)
+; CHECK: }
+
+declare void @_Z9may_throwv() #1
+
+declare i32 @__CxxFrameHandler3(...)
+
+; Function Attrs: nounwind readnone
+declare i32 @llvm.eh.typeid.for(i8*) #2
+
+declare i8* @llvm.eh.begincatch(i8*)
+
+declare void @llvm.eh.endcatch()
+
+declare void @_Z10handle_intv() #1
+
+attributes #0 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #2 = { nounwind readnone }
+attributes #3 = { nounwind }
+
+!llvm.ident = !{!0}
+
+!0 = !{!"clang version 3.7.0 (trunk 227474) (llvm/trunk 227508)"}
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