mirror of
https://github.com/c64scene-ar/llvm-6502.git
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88c74bffbf
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230535 91177308-0d34-0410-b5e6-96231b3b80d8
627 lines
25 KiB
C++
627 lines
25 KiB
C++
//===-- WinEHPrepare - Prepare exception handling for code generation ---===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This pass lowers LLVM IR exception handling into something closer to what the
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// backend wants. It snifs the personality function to see which kind of
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// preparation is necessary. If the personality function uses the Itanium LSDA,
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// this pass delegates to the DWARF EH preparation pass.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/Passes.h"
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#include "llvm/ADT/MapVector.h"
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#include "llvm/ADT/TinyPtrVector.h"
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#include "llvm/Analysis/LibCallSemantics.h"
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#include "llvm/IR/Function.h"
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#include "llvm/IR/IRBuilder.h"
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#include "llvm/IR/Instructions.h"
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#include "llvm/IR/IntrinsicInst.h"
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#include "llvm/IR/Module.h"
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#include "llvm/IR/PatternMatch.h"
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#include "llvm/Pass.h"
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#include "llvm/Transforms/Utils/Cloning.h"
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#include "llvm/Transforms/Utils/Local.h"
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#include <memory>
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using namespace llvm;
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using namespace llvm::PatternMatch;
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#define DEBUG_TYPE "winehprepare"
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namespace {
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struct HandlerAllocas {
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TinyPtrVector<AllocaInst *> Allocas;
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int ParentFrameAllocationIndex;
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};
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// This map is used to model frame variable usage during outlining, to
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// construct a structure type to hold the frame variables in a frame
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// allocation block, and to remap the frame variable allocas (including
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// spill locations as needed) to GEPs that get the variable from the
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// frame allocation structure.
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typedef MapVector<AllocaInst *, HandlerAllocas> FrameVarInfoMap;
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class WinEHPrepare : public FunctionPass {
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std::unique_ptr<FunctionPass> DwarfPrepare;
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public:
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static char ID; // Pass identification, replacement for typeid.
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WinEHPrepare(const TargetMachine *TM = nullptr)
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: FunctionPass(ID), DwarfPrepare(createDwarfEHPass(TM)) {}
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bool runOnFunction(Function &Fn) override;
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bool doFinalization(Module &M) override;
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void getAnalysisUsage(AnalysisUsage &AU) const override;
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const char *getPassName() const override {
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return "Windows exception handling preparation";
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}
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private:
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bool prepareCPPEHHandlers(Function &F,
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SmallVectorImpl<LandingPadInst *> &LPads);
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bool outlineCatchHandler(Function *SrcFn, Constant *SelectorType,
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LandingPadInst *LPad, CallInst *&EHAlloc,
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AllocaInst *&EHObjPtr, FrameVarInfoMap &VarInfo);
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};
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class WinEHFrameVariableMaterializer : public ValueMaterializer {
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public:
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WinEHFrameVariableMaterializer(Function *OutlinedFn,
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FrameVarInfoMap &FrameVarInfo);
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~WinEHFrameVariableMaterializer() {}
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virtual Value *materializeValueFor(Value *V) override;
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private:
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FrameVarInfoMap &FrameVarInfo;
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IRBuilder<> Builder;
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};
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class WinEHCatchDirector : public CloningDirector {
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public:
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WinEHCatchDirector(LandingPadInst *LPI, Function *CatchFn, Value *Selector,
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Value *EHObj, FrameVarInfoMap &VarInfo)
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: LPI(LPI), CurrentSelector(Selector->stripPointerCasts()), EHObj(EHObj),
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Materializer(CatchFn, VarInfo),
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SelectorIDType(Type::getInt32Ty(LPI->getContext())),
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Int8PtrType(Type::getInt8PtrTy(LPI->getContext())) {}
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CloningAction handleInstruction(ValueToValueMapTy &VMap,
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const Instruction *Inst,
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BasicBlock *NewBB) override;
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ValueMaterializer *getValueMaterializer() override { return &Materializer; }
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private:
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LandingPadInst *LPI;
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Value *CurrentSelector;
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Value *EHObj;
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WinEHFrameVariableMaterializer Materializer;
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Type *SelectorIDType;
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Type *Int8PtrType;
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const Value *ExtractedEHPtr;
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const Value *ExtractedSelector;
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const Value *EHPtrStoreAddr;
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const Value *SelectorStoreAddr;
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};
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} // end anonymous namespace
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char WinEHPrepare::ID = 0;
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INITIALIZE_TM_PASS(WinEHPrepare, "winehprepare", "Prepare Windows exceptions",
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false, false)
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FunctionPass *llvm::createWinEHPass(const TargetMachine *TM) {
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return new WinEHPrepare(TM);
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}
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static bool isMSVCPersonality(EHPersonality Pers) {
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return Pers == EHPersonality::MSVC_Win64SEH ||
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Pers == EHPersonality::MSVC_CXX;
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}
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bool WinEHPrepare::runOnFunction(Function &Fn) {
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SmallVector<LandingPadInst *, 4> LPads;
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SmallVector<ResumeInst *, 4> Resumes;
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for (BasicBlock &BB : Fn) {
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if (auto *LP = BB.getLandingPadInst())
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LPads.push_back(LP);
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if (auto *Resume = dyn_cast<ResumeInst>(BB.getTerminator()))
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Resumes.push_back(Resume);
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}
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// No need to prepare functions that lack landing pads.
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if (LPads.empty())
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return false;
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// Classify the personality to see what kind of preparation we need.
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EHPersonality Pers = classifyEHPersonality(LPads.back()->getPersonalityFn());
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// Delegate through to the DWARF pass if this is unrecognized.
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if (!isMSVCPersonality(Pers))
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return DwarfPrepare->runOnFunction(Fn);
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// FIXME: This only returns true if the C++ EH handlers were outlined.
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// When that code is complete, it should always return whatever
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// prepareCPPEHHandlers returns.
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if (Pers == EHPersonality::MSVC_CXX && prepareCPPEHHandlers(Fn, LPads))
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return true;
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// FIXME: SEH Cleanups are unimplemented. Replace them with unreachable.
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if (Resumes.empty())
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return false;
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for (ResumeInst *Resume : Resumes) {
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IRBuilder<>(Resume).CreateUnreachable();
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Resume->eraseFromParent();
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}
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return true;
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}
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bool WinEHPrepare::doFinalization(Module &M) {
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return DwarfPrepare->doFinalization(M);
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}
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void WinEHPrepare::getAnalysisUsage(AnalysisUsage &AU) const {
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DwarfPrepare->getAnalysisUsage(AU);
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}
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bool WinEHPrepare::prepareCPPEHHandlers(
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Function &F, SmallVectorImpl<LandingPadInst *> &LPads) {
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// These containers are used to re-map frame variables that are used in
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// outlined catch and cleanup handlers. They will be populated as the
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// handlers are outlined.
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FrameVarInfoMap FrameVarInfo;
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SmallVector<CallInst *, 4> HandlerAllocs;
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SmallVector<AllocaInst *, 4> HandlerEHObjPtrs;
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bool HandlersOutlined = false;
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for (LandingPadInst *LPad : LPads) {
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// Look for evidence that this landingpad has already been processed.
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bool LPadHasActionList = false;
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BasicBlock *LPadBB = LPad->getParent();
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for (Instruction &Inst : LPadBB->getInstList()) {
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// FIXME: Make this an intrinsic.
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if (auto *Call = dyn_cast<CallInst>(&Inst))
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if (Call->getCalledFunction()->getName() == "llvm.eh.actions") {
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LPadHasActionList = true;
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break;
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}
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}
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// If we've already outlined the handlers for this landingpad,
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// there's nothing more to do here.
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if (LPadHasActionList)
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continue;
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for (unsigned Idx = 0, NumClauses = LPad->getNumClauses(); Idx < NumClauses;
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++Idx) {
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if (LPad->isCatch(Idx)) {
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// Create a new instance of the handler data structure in the
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// HandlerData vector.
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CallInst *EHAlloc = nullptr;
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AllocaInst *EHObjPtr = nullptr;
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bool Outlined = outlineCatchHandler(&F, LPad->getClause(Idx), LPad,
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EHAlloc, EHObjPtr, FrameVarInfo);
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if (Outlined) {
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HandlersOutlined = true;
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// These values must be resolved after all handlers have been
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// outlined.
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if (EHAlloc)
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HandlerAllocs.push_back(EHAlloc);
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if (EHObjPtr)
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HandlerEHObjPtrs.push_back(EHObjPtr);
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}
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} // End if (isCatch)
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} // End for each clause
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} // End for each landingpad
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// If nothing got outlined, there is no more processing to be done.
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if (!HandlersOutlined)
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return false;
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// FIXME: We will replace the landingpad bodies with llvm.eh.actions
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// calls and indirect branches here and then delete blocks
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// which are no longer reachable. That will get rid of the
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// handlers that we have outlined. There is code below
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// that looks for allocas with no uses in the parent function.
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// That will only happen after the pruning is implemented.
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// Remap the frame variables.
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SmallVector<Type *, 2> StructTys;
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StructTys.push_back(Type::getInt32Ty(F.getContext())); // EH state
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StructTys.push_back(Type::getInt8PtrTy(F.getContext())); // EH object
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// Start the index at two since we always have the above fields at 0 and 1.
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int Idx = 2;
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// FIXME: Sort the FrameVarInfo vector by the ParentAlloca size and alignment
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// and add padding as necessary to provide the proper alignment.
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// Map the alloca instructions to the corresponding index in the
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// frame allocation structure. If any alloca is used only in a single
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// handler and is not used in the parent frame after outlining, it will
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// be assigned an index of -1, meaning the handler can keep its
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// "temporary" alloca and the original alloca can be erased from the
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// parent function. If we later encounter this alloca in a second
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// handler, we will assign it a place in the frame allocation structure
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// at that time. Since the instruction replacement doesn't happen until
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// all the entries in the HandlerData have been processed this isn't a
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// problem.
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for (auto &VarInfoEntry : FrameVarInfo) {
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AllocaInst *ParentAlloca = VarInfoEntry.first;
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HandlerAllocas &AllocaInfo = VarInfoEntry.second;
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// If the instruction still has uses in the parent function or if it is
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// referenced by more than one handler, add it to the frame allocation
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// structure.
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if (ParentAlloca->getNumUses() != 0 || AllocaInfo.Allocas.size() > 1) {
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Type *VarTy = ParentAlloca->getAllocatedType();
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StructTys.push_back(VarTy);
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AllocaInfo.ParentFrameAllocationIndex = Idx++;
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} else {
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// If the variable is not used in the parent frame and it is only used
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// in one handler, the alloca can be removed from the parent frame
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// and the handler will keep its "temporary" alloca to define the value.
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// An element index of -1 is used to indicate this condition.
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AllocaInfo.ParentFrameAllocationIndex = -1;
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}
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}
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// Having filled the StructTys vector and assigned an index to each element,
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// we can now create the structure.
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StructType *EHDataStructTy = StructType::create(
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F.getContext(), StructTys, "struct." + F.getName().str() + ".ehdata");
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IRBuilder<> Builder(F.getParent()->getContext());
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// Create a frame allocation.
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Module *M = F.getParent();
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LLVMContext &Context = M->getContext();
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BasicBlock *Entry = &F.getEntryBlock();
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Builder.SetInsertPoint(Entry->getFirstInsertionPt());
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Function *FrameAllocFn =
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Intrinsic::getDeclaration(M, Intrinsic::frameallocate);
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uint64_t EHAllocSize = M->getDataLayout()->getTypeAllocSize(EHDataStructTy);
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Value *FrameAllocArgs[] = {
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ConstantInt::get(Type::getInt32Ty(Context), EHAllocSize)};
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CallInst *FrameAlloc =
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Builder.CreateCall(FrameAllocFn, FrameAllocArgs, "frame.alloc");
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Value *FrameEHData = Builder.CreateBitCast(
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FrameAlloc, EHDataStructTy->getPointerTo(), "eh.data");
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// Now visit each handler that is using the structure and bitcast its EHAlloc
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// value to be a pointer to the frame alloc structure.
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DenseMap<Function *, Value *> EHDataMap;
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for (CallInst *EHAlloc : HandlerAllocs) {
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// The EHAlloc has no uses at this time, so we need to just insert the
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// cast before the next instruction. There is always a next instruction.
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BasicBlock::iterator II = EHAlloc;
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++II;
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Builder.SetInsertPoint(cast<Instruction>(II));
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Value *EHData = Builder.CreateBitCast(
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EHAlloc, EHDataStructTy->getPointerTo(), "eh.data");
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EHDataMap[EHAlloc->getParent()->getParent()] = EHData;
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}
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// Next, replace the place-holder EHObjPtr allocas with GEP instructions
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// that pull the EHObjPtr from the frame alloc structure
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for (AllocaInst *EHObjPtr : HandlerEHObjPtrs) {
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Value *EHData = EHDataMap[EHObjPtr->getParent()->getParent()];
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Builder.SetInsertPoint(EHObjPtr);
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Value *ElementPtr = Builder.CreateConstInBoundsGEP2_32(EHData, 0, 1);
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EHObjPtr->replaceAllUsesWith(ElementPtr);
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EHObjPtr->removeFromParent();
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ElementPtr->takeName(EHObjPtr);
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delete EHObjPtr;
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}
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// Finally, replace all of the temporary allocas for frame variables used in
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// the outlined handlers and the original frame allocas with GEP instructions
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// that get the equivalent pointer from the frame allocation struct.
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for (auto &VarInfoEntry : FrameVarInfo) {
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AllocaInst *ParentAlloca = VarInfoEntry.first;
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HandlerAllocas &AllocaInfo = VarInfoEntry.second;
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int Idx = AllocaInfo.ParentFrameAllocationIndex;
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// If we have an index of -1 for this instruction, it means it isn't used
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// outside of this handler. In that case, we just keep the "temporary"
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// alloca in the handler and erase the original alloca from the parent.
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if (Idx == -1) {
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ParentAlloca->eraseFromParent();
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} else {
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// Otherwise, we replace the parent alloca and all outlined allocas
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// which map to it with GEP instructions.
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// First replace the original alloca.
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Builder.SetInsertPoint(ParentAlloca);
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Builder.SetCurrentDebugLocation(ParentAlloca->getDebugLoc());
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Value *ElementPtr =
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Builder.CreateConstInBoundsGEP2_32(FrameEHData, 0, Idx);
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ParentAlloca->replaceAllUsesWith(ElementPtr);
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ParentAlloca->removeFromParent();
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ElementPtr->takeName(ParentAlloca);
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delete ParentAlloca;
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// Next replace all outlined allocas that are mapped to it.
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for (AllocaInst *TempAlloca : AllocaInfo.Allocas) {
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Value *EHData = EHDataMap[TempAlloca->getParent()->getParent()];
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// FIXME: Sink this GEP into the blocks where it is used.
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Builder.SetInsertPoint(TempAlloca);
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Builder.SetCurrentDebugLocation(TempAlloca->getDebugLoc());
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ElementPtr = Builder.CreateConstInBoundsGEP2_32(EHData, 0, Idx);
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TempAlloca->replaceAllUsesWith(ElementPtr);
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TempAlloca->removeFromParent();
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ElementPtr->takeName(TempAlloca);
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delete TempAlloca;
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}
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} // end else of if (Idx == -1)
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} // End for each FrameVarInfo entry.
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return HandlersOutlined;
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}
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bool WinEHPrepare::outlineCatchHandler(Function *SrcFn, Constant *SelectorType,
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LandingPadInst *LPad, CallInst *&EHAlloc,
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AllocaInst *&EHObjPtr,
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FrameVarInfoMap &VarInfo) {
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Module *M = SrcFn->getParent();
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LLVMContext &Context = M->getContext();
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// Create a new function to receive the handler contents.
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Type *Int8PtrType = Type::getInt8PtrTy(Context);
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std::vector<Type *> ArgTys;
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ArgTys.push_back(Int8PtrType);
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ArgTys.push_back(Int8PtrType);
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FunctionType *FnType = FunctionType::get(Int8PtrType, ArgTys, false);
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Function *CatchHandler = Function::Create(
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FnType, GlobalVariable::ExternalLinkage, SrcFn->getName() + ".catch", M);
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// Generate a standard prolog to setup the frame recovery structure.
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IRBuilder<> Builder(Context);
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BasicBlock *Entry = BasicBlock::Create(Context, "catch.entry");
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CatchHandler->getBasicBlockList().push_front(Entry);
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Builder.SetInsertPoint(Entry);
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Builder.SetCurrentDebugLocation(LPad->getDebugLoc());
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// The outlined handler will be called with the parent's frame pointer as
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// its second argument. To enable the handler to access variables from
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// the parent frame, we use that pointer to get locate a special block
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// of memory that was allocated using llvm.eh.allocateframe for this
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// purpose. During the outlining process we will determine which frame
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// variables are used in handlers and create a structure that maps these
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// variables into the frame allocation block.
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//
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// The frame allocation block also contains an exception state variable
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// used by the runtime and a pointer to the exception object pointer
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// which will be filled in by the runtime for use in the handler.
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Function *RecoverFrameFn =
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Intrinsic::getDeclaration(M, Intrinsic::framerecover);
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Value *RecoverArgs[] = {Builder.CreateBitCast(SrcFn, Int8PtrType, ""),
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&(CatchHandler->getArgumentList().back())};
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EHAlloc = Builder.CreateCall(RecoverFrameFn, RecoverArgs, "eh.alloc");
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// This alloca is only temporary. We'll be replacing it once we know all the
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// frame variables that need to go in the frame allocation structure.
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EHObjPtr = Builder.CreateAlloca(Int8PtrType, 0, "eh.obj.ptr");
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// This will give us a raw pointer to the exception object, which
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// corresponds to the formal parameter of the catch statement. If the
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// handler uses this object, we will generate code during the outlining
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// process to cast the pointer to the appropriate type and deference it
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// as necessary. The un-outlined landing pad code represents the
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// exception object as the result of the llvm.eh.begincatch call.
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Value *EHObj = Builder.CreateLoad(EHObjPtr, false, "eh.obj");
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ValueToValueMapTy VMap;
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// FIXME: Map other values referenced in the filter handler.
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WinEHCatchDirector Director(LPad, CatchHandler, SelectorType, EHObj, VarInfo);
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SmallVector<ReturnInst *, 8> Returns;
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ClonedCodeInfo InlinedFunctionInfo;
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BasicBlock::iterator II = LPad;
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CloneAndPruneIntoFromInst(CatchHandler, SrcFn, ++II, VMap,
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/*ModuleLevelChanges=*/false, Returns, "",
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&InlinedFunctionInfo,
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SrcFn->getParent()->getDataLayout(), &Director);
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// Move all the instructions in the first cloned block into our entry block.
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BasicBlock *FirstClonedBB = std::next(Function::iterator(Entry));
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Entry->getInstList().splice(Entry->end(), FirstClonedBB->getInstList());
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FirstClonedBB->eraseFromParent();
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return true;
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}
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CloningDirector::CloningAction WinEHCatchDirector::handleInstruction(
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ValueToValueMapTy &VMap, const Instruction *Inst, BasicBlock *NewBB) {
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// Intercept instructions which extract values from the landing pad aggregate.
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if (auto *Extract = dyn_cast<ExtractValueInst>(Inst)) {
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if (Extract->getAggregateOperand() == LPI) {
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assert(Extract->getNumIndices() == 1 &&
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"Unexpected operation: extracting both landing pad values");
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assert((*(Extract->idx_begin()) == 0 || *(Extract->idx_begin()) == 1) &&
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"Unexpected operation: extracting an unknown landing pad element");
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|
|
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;
|
|
}
|
|
|
|
WinEHFrameVariableMaterializer::WinEHFrameVariableMaterializer(
|
|
Function *OutlinedFn, FrameVarInfoMap &FrameVarInfo)
|
|
: FrameVarInfo(FrameVarInfo), Builder(OutlinedFn->getContext()) {
|
|
Builder.SetInsertPoint(&OutlinedFn->getEntryBlock());
|
|
// FIXME: Do something with the FrameVarMapped so that it is shared across the
|
|
// function.
|
|
}
|
|
|
|
Value *WinEHFrameVariableMaterializer::materializeValueFor(Value *V) {
|
|
// If we're asked to materialize an alloca variable, we temporarily
|
|
// create a matching alloca in the outlined function. When all the
|
|
// outlining is complete, we'll collect these into a structure and
|
|
// replace these temporary allocas with GEPs referencing the frame
|
|
// allocation block.
|
|
if (auto *AV = dyn_cast<AllocaInst>(V)) {
|
|
AllocaInst *NewAlloca = Builder.CreateAlloca(
|
|
AV->getAllocatedType(), AV->getArraySize(), AV->getName());
|
|
FrameVarInfo[AV].Allocas.push_back(NewAlloca);
|
|
return NewAlloca;
|
|
}
|
|
|
|
// FIXME: Do PHI nodes need special handling?
|
|
|
|
// FIXME: Are there other cases we can handle better? GEP, ExtractValue, etc.
|
|
|
|
// FIXME: This doesn't work during cloning because it finds an instruction
|
|
// in the use list that isn't yet part of a basic block.
|
|
#if 0
|
|
// If we're asked to remap some other instruction, we'll need to
|
|
// spill it to an alloca variable in the parent function and add a
|
|
// temporary alloca in the outlined function to be processed as
|
|
// described above.
|
|
Instruction *Inst = dyn_cast<Instruction>(V);
|
|
if (Inst) {
|
|
AllocaInst *Spill = DemoteRegToStack(*Inst, true);
|
|
AllocaInst *NewAlloca = Builder.CreateAlloca(Spill->getAllocatedType(),
|
|
Spill->getArraySize());
|
|
FrameVarMap[AV] = NewAlloca;
|
|
return NewAlloca;
|
|
}
|
|
#endif
|
|
|
|
return nullptr;
|
|
}
|