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diff --git a/gnu/llvm/lib/CodeGen/DwarfEHPrepare.cpp b/gnu/llvm/lib/CodeGen/DwarfEHPrepare.cpp
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-//===- DwarfEHPrepare - 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 mulches exception handling code into a form adapted to code
-// generation. Required if using dwarf exception handling.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/ADT/BitVector.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Analysis/CFG.h"
-#include "llvm/Analysis/EHPersonalities.h"
-#include "llvm/Analysis/TargetTransformInfo.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/CodeGen/RuntimeLibcalls.h"
-#include "llvm/CodeGen/TargetLowering.h"
-#include "llvm/CodeGen/TargetPassConfig.h"
-#include "llvm/CodeGen/TargetSubtargetInfo.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Dominators.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/Module.h"
-#include "llvm/IR/Type.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/Casting.h"
-#include "llvm/Target/TargetMachine.h"
-#include <cstddef>
-
-using namespace llvm;
-
-#define DEBUG_TYPE "dwarfehprepare"
-
-STATISTIC(NumResumesLowered, "Number of resume calls lowered");
-
-namespace {
-
- class DwarfEHPrepare : public FunctionPass {
- // RewindFunction - _Unwind_Resume or the target equivalent.
- Constant *RewindFunction = nullptr;
-
- DominatorTree *DT = nullptr;
- const TargetLowering *TLI = nullptr;
-
- bool InsertUnwindResumeCalls(Function &Fn);
- Value *GetExceptionObject(ResumeInst *RI);
- size_t
- pruneUnreachableResumes(Function &Fn,
- SmallVectorImpl<ResumeInst *> &Resumes,
- SmallVectorImpl<LandingPadInst *> &CleanupLPads);
-
- public:
- static char ID; // Pass identification, replacement for typeid.
-
- DwarfEHPrepare() : FunctionPass(ID) {}
-
- bool runOnFunction(Function &Fn) override;
-
- bool doFinalization(Module &M) override {
- RewindFunction = nullptr;
- return false;
- }
-
- void getAnalysisUsage(AnalysisUsage &AU) const override;
-
- StringRef getPassName() const override {
- return "Exception handling preparation";
- }
- };
-
-} // end anonymous namespace
-
-char DwarfEHPrepare::ID = 0;
-
-INITIALIZE_PASS_BEGIN(DwarfEHPrepare, DEBUG_TYPE,
- "Prepare DWARF exceptions", false, false)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
-INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
-INITIALIZE_PASS_END(DwarfEHPrepare, DEBUG_TYPE,
- "Prepare DWARF exceptions", false, false)
-
-FunctionPass *llvm::createDwarfEHPass() { return new DwarfEHPrepare(); }
-
-void DwarfEHPrepare::getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<TargetPassConfig>();
- AU.addRequired<TargetTransformInfoWrapperPass>();
- AU.addRequired<DominatorTreeWrapperPass>();
-}
-
-/// GetExceptionObject - Return the exception object from the value passed into
-/// the 'resume' instruction (typically an aggregate). Clean up any dead
-/// instructions, including the 'resume' instruction.
-Value *DwarfEHPrepare::GetExceptionObject(ResumeInst *RI) {
- Value *V = RI->getOperand(0);
- Value *ExnObj = nullptr;
- InsertValueInst *SelIVI = dyn_cast<InsertValueInst>(V);
- LoadInst *SelLoad = nullptr;
- InsertValueInst *ExcIVI = nullptr;
- bool EraseIVIs = false;
-
- if (SelIVI) {
- if (SelIVI->getNumIndices() == 1 && *SelIVI->idx_begin() == 1) {
- ExcIVI = dyn_cast<InsertValueInst>(SelIVI->getOperand(0));
- if (ExcIVI && isa<UndefValue>(ExcIVI->getOperand(0)) &&
- ExcIVI->getNumIndices() == 1 && *ExcIVI->idx_begin() == 0) {
- ExnObj = ExcIVI->getOperand(1);
- SelLoad = dyn_cast<LoadInst>(SelIVI->getOperand(1));
- EraseIVIs = true;
- }
- }
- }
-
- if (!ExnObj)
- ExnObj = ExtractValueInst::Create(RI->getOperand(0), 0, "exn.obj", RI);
-
- RI->eraseFromParent();
-
- if (EraseIVIs) {
- if (SelIVI->use_empty())
- SelIVI->eraseFromParent();
- if (ExcIVI->use_empty())
- ExcIVI->eraseFromParent();
- if (SelLoad && SelLoad->use_empty())
- SelLoad->eraseFromParent();
- }
-
- return ExnObj;
-}
-
-/// Replace resumes that are not reachable from a cleanup landing pad with
-/// unreachable and then simplify those blocks.
-size_t DwarfEHPrepare::pruneUnreachableResumes(
- Function &Fn, SmallVectorImpl<ResumeInst *> &Resumes,
- SmallVectorImpl<LandingPadInst *> &CleanupLPads) {
- BitVector ResumeReachable(Resumes.size());
- size_t ResumeIndex = 0;
- for (auto *RI : Resumes) {
- for (auto *LP : CleanupLPads) {
- if (isPotentiallyReachable(LP, RI, DT)) {
- ResumeReachable.set(ResumeIndex);
- break;
- }
- }
- ++ResumeIndex;
- }
-
- // If everything is reachable, there is no change.
- if (ResumeReachable.all())
- return Resumes.size();
-
- const TargetTransformInfo &TTI =
- getAnalysis<TargetTransformInfoWrapperPass>().getTTI(Fn);
- LLVMContext &Ctx = Fn.getContext();
-
- // Otherwise, insert unreachable instructions and call simplifycfg.
- size_t ResumesLeft = 0;
- for (size_t I = 0, E = Resumes.size(); I < E; ++I) {
- ResumeInst *RI = Resumes[I];
- if (ResumeReachable[I]) {
- Resumes[ResumesLeft++] = RI;
- } else {
- BasicBlock *BB = RI->getParent();
- new UnreachableInst(Ctx, RI);
- RI->eraseFromParent();
- simplifyCFG(BB, TTI);
- }
- }
- Resumes.resize(ResumesLeft);
- return ResumesLeft;
-}
-
-/// InsertUnwindResumeCalls - Convert the ResumeInsts that are still present
-/// into calls to the appropriate _Unwind_Resume function.
-bool DwarfEHPrepare::InsertUnwindResumeCalls(Function &Fn) {
- SmallVector<ResumeInst*, 16> Resumes;
- SmallVector<LandingPadInst*, 16> CleanupLPads;
- for (BasicBlock &BB : Fn) {
- if (auto *RI = dyn_cast<ResumeInst>(BB.getTerminator()))
- Resumes.push_back(RI);
- if (auto *LP = BB.getLandingPadInst())
- if (LP->isCleanup())
- CleanupLPads.push_back(LP);
- }
-
- if (Resumes.empty())
- return false;
-
- // Check the personality, don't do anything if it's scope-based.
- EHPersonality Pers = classifyEHPersonality(Fn.getPersonalityFn());
- if (isScopedEHPersonality(Pers))
- return false;
-
- LLVMContext &Ctx = Fn.getContext();
-
- size_t ResumesLeft = pruneUnreachableResumes(Fn, Resumes, CleanupLPads);
- if (ResumesLeft == 0)
- return true; // We pruned them all.
-
- // Find the rewind function if we didn't already.
- if (!RewindFunction) {
- FunctionType *FTy = FunctionType::get(Type::getVoidTy(Ctx),
- Type::getInt8PtrTy(Ctx), false);
- const char *RewindName = TLI->getLibcallName(RTLIB::UNWIND_RESUME);
- RewindFunction = Fn.getParent()->getOrInsertFunction(RewindName, FTy);
- }
-
- // Create the basic block where the _Unwind_Resume call will live.
- if (ResumesLeft == 1) {
- // Instead of creating a new BB and PHI node, just append the call to
- // _Unwind_Resume to the end of the single resume block.
- ResumeInst *RI = Resumes.front();
- BasicBlock *UnwindBB = RI->getParent();
- Value *ExnObj = GetExceptionObject(RI);
-
- // Call the _Unwind_Resume function.
- CallInst *CI = CallInst::Create(RewindFunction, ExnObj, "", UnwindBB);
- CI->setCallingConv(TLI->getLibcallCallingConv(RTLIB::UNWIND_RESUME));
-
- // We never expect _Unwind_Resume to return.
- new UnreachableInst(Ctx, UnwindBB);
- return true;
- }
-
- BasicBlock *UnwindBB = BasicBlock::Create(Ctx, "unwind_resume", &Fn);
- PHINode *PN = PHINode::Create(Type::getInt8PtrTy(Ctx), ResumesLeft,
- "exn.obj", UnwindBB);
-
- // Extract the exception object from the ResumeInst and add it to the PHI node
- // that feeds the _Unwind_Resume call.
- for (ResumeInst *RI : Resumes) {
- BasicBlock *Parent = RI->getParent();
- BranchInst::Create(UnwindBB, Parent);
-
- Value *ExnObj = GetExceptionObject(RI);
- PN->addIncoming(ExnObj, Parent);
-
- ++NumResumesLowered;
- }
-
- // Call the function.
- CallInst *CI = CallInst::Create(RewindFunction, PN, "", UnwindBB);
- CI->setCallingConv(TLI->getLibcallCallingConv(RTLIB::UNWIND_RESUME));
-
- // We never expect _Unwind_Resume to return.
- new UnreachableInst(Ctx, UnwindBB);
- return true;
-}
-
-bool DwarfEHPrepare::runOnFunction(Function &Fn) {
- const TargetMachine &TM =
- getAnalysis<TargetPassConfig>().getTM<TargetMachine>();
- DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
- TLI = TM.getSubtargetImpl(Fn)->getTargetLowering();
- bool Changed = InsertUnwindResumeCalls(Fn);
- DT = nullptr;
- TLI = nullptr;
- return Changed;
-}
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