X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FWinEHPrepare.cpp;h=0d26ed333ca7134928023f870ce50082299c389f;hb=00552e3875ee5f382db6c98286a241a7d0efe1b8;hp=2c72a556f75a28fde29adef20c948bac8dd0cfa4;hpb=d3a9dd70429239093b136e178147ec0425dab269;p=oota-llvm.git diff --git a/lib/CodeGen/WinEHPrepare.cpp b/lib/CodeGen/WinEHPrepare.cpp index 2c72a556f75..0d26ed333ca 100644 --- a/lib/CodeGen/WinEHPrepare.cpp +++ b/lib/CodeGen/WinEHPrepare.cpp @@ -24,6 +24,7 @@ #include "llvm/ADT/Triple.h" #include "llvm/ADT/TinyPtrVector.h" #include "llvm/Analysis/LibCallSemantics.h" +#include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/CodeGen/WinEHFuncInfo.h" #include "llvm/IR/Dominators.h" #include "llvm/IR/Function.h" @@ -75,7 +76,7 @@ public: WinEHPrepare(const TargetMachine *TM = nullptr) : FunctionPass(ID) { if (TM) - TheTriple = Triple(TM->getTargetTriple()); + TheTriple = TM->getTargetTriple(); } bool runOnFunction(Function &Fn) override; @@ -91,6 +92,7 @@ public: private: bool prepareExceptionHandlers(Function &F, SmallVectorImpl &LPads); + void identifyEHBlocks(Function &F, SmallVectorImpl &LPads); void promoteLandingPadValues(LandingPadInst *LPad); void demoteValuesLiveAcrossHandlers(Function &F, SmallVectorImpl &LPads); @@ -98,16 +100,18 @@ private: SetVector &EHReturnBlocks); void findCXXEHReturnPoints(Function &F, SetVector &EHReturnBlocks); + void getPossibleReturnTargets(Function *ParentF, Function *HandlerF, + SetVector &Targets); void completeNestedLandingPad(Function *ParentFn, LandingPadInst *OutlinedLPad, const LandingPadInst *OriginalLPad, FrameVarInfoMap &VarInfo); - Function *createHandlerFunc(Type *RetTy, const Twine &Name, Module *M, - Value *&ParentFP); + Function *createHandlerFunc(Function *ParentFn, Type *RetTy, + const Twine &Name, Module *M, Value *&ParentFP); bool outlineHandler(ActionHandler *Action, Function *SrcFn, LandingPadInst *LPad, BasicBlock *StartBB, FrameVarInfoMap &VarInfo); - void addStubInvokeToHandlerIfNeeded(Function *Handler, Value *PersonalityFn); + void addStubInvokeToHandlerIfNeeded(Function *Handler); void mapLandingPadBlocks(LandingPadInst *LPad, LandingPadActions &Actions); CatchHandler *findCatchHandler(BasicBlock *BB, BasicBlock *&NextBB, @@ -121,10 +125,14 @@ private: // All fields are reset by runOnFunction. DominatorTree *DT = nullptr; + const TargetLibraryInfo *LibInfo = nullptr; EHPersonality Personality = EHPersonality::Unknown; CatchHandlerMapTy CatchHandlerMap; CleanupHandlerMapTy CleanupHandlerMap; DenseMap LPadMaps; + SmallPtrSet NormalBlocks; + SmallPtrSet EHBlocks; + SetVector EHReturnBlocks; // This maps landing pad instructions found in outlined handlers to // the landing pad instruction in the parent function from which they @@ -147,7 +155,7 @@ private: // outlined but before the outlined code is pruned from the parent function. DenseMap LPadTargetBlocks; - // Map from outlined handler to call to llvm.frameaddress(1). Only used for + // Map from outlined handler to call to parent local address. Only used for // 32-bit EH. DenseMap HandlerToParentFP; @@ -212,6 +220,9 @@ public: virtual CloningAction handleTypeIdFor(ValueToValueMapTy &VMap, const Instruction *Inst, BasicBlock *NewBB) = 0; + virtual CloningAction handleIndirectBr(ValueToValueMapTy &VMap, + const IndirectBrInst *IBr, + BasicBlock *NewBB) = 0; virtual CloningAction handleInvoke(ValueToValueMapTy &VMap, const InvokeInst *Invoke, BasicBlock *NewBB) = 0; @@ -242,10 +253,12 @@ public: WinEHCatchDirector( Function *CatchFn, Value *ParentFP, Value *Selector, FrameVarInfoMap &VarInfo, LandingPadMap &LPadMap, - DenseMap &NestedLPads) + DenseMap &NestedLPads, + DominatorTree *DT, SmallPtrSetImpl &EHBlocks) : WinEHCloningDirectorBase(CatchFn, ParentFP, VarInfo, LPadMap), CurrentSelector(Selector->stripPointerCasts()), - ExceptionObjectVar(nullptr), NestedLPtoOriginalLP(NestedLPads) {} + ExceptionObjectVar(nullptr), NestedLPtoOriginalLP(NestedLPads), + DT(DT), EHBlocks(EHBlocks) {} CloningAction handleBeginCatch(ValueToValueMapTy &VMap, const Instruction *Inst, @@ -255,6 +268,9 @@ public: CloningAction handleTypeIdFor(ValueToValueMapTy &VMap, const Instruction *Inst, BasicBlock *NewBB) override; + CloningAction handleIndirectBr(ValueToValueMapTy &VMap, + const IndirectBrInst *IBr, + BasicBlock *NewBB) override; CloningAction handleInvoke(ValueToValueMapTy &VMap, const InvokeInst *Invoke, BasicBlock *NewBB) override; CloningAction handleResume(ValueToValueMapTy &VMap, const ResumeInst *Resume, @@ -277,6 +293,8 @@ private: // This will be a reference to the field of the same name in the WinEHPrepare // object which instantiates this WinEHCatchDirector object. DenseMap &NestedLPtoOriginalLP; + DominatorTree *DT; + SmallPtrSetImpl &EHBlocks; }; class WinEHCleanupDirector : public WinEHCloningDirectorBase { @@ -294,6 +312,9 @@ public: CloningAction handleTypeIdFor(ValueToValueMapTy &VMap, const Instruction *Inst, BasicBlock *NewBB) override; + CloningAction handleIndirectBr(ValueToValueMapTy &VMap, + const IndirectBrInst *IBr, + BasicBlock *NewBB) override; CloningAction handleInvoke(ValueToValueMapTy &VMap, const InvokeInst *Invoke, BasicBlock *NewBB) override; CloningAction handleResume(ValueToValueMapTy &VMap, const ResumeInst *Resume, @@ -358,13 +379,14 @@ bool WinEHPrepare::runOnFunction(Function &Fn) { return false; // Classify the personality to see what kind of preparation we need. - Personality = classifyEHPersonality(LPads.back()->getPersonalityFn()); + Personality = classifyEHPersonality(Fn.getPersonalityFn()); // Do nothing if this is not an MSVC personality. if (!isMSVCEHPersonality(Personality)) return false; DT = &getAnalysis().getDomTree(); + LibInfo = &getAnalysis().getTLI(); // If there were any landing pads, prepareExceptionHandlers will make changes. prepareExceptionHandlers(Fn, LPads); @@ -375,6 +397,7 @@ bool WinEHPrepare::doFinalization(Module &M) { return false; } void WinEHPrepare::getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequired(); + AU.addRequired(); } static bool isSelectorDispatch(BasicBlock *BB, BasicBlock *&CatchHandler, @@ -510,9 +533,9 @@ void WinEHPrepare::findSEHEHReturnPoints( BasicBlock *NextBB; Constant *Selector; if (isSelectorDispatch(BB, CatchHandler, Selector, NextBB)) { - // Split the edge if there is a phi node. Returning from EH to a phi node - // is just as impossible as having a phi after an indirectbr. - if (isa(CatchHandler->begin())) { + // Split the edge if there are multiple predecessors. This creates a place + // where we can insert EH recovery code. + if (!CatchHandler->getSinglePredecessor()) { DEBUG(dbgs() << "splitting EH return edge from " << BB->getName() << " to " << CatchHandler->getName() << '\n'); BBI = CatchHandler = SplitCriticalEdge( @@ -523,13 +546,8 @@ void WinEHPrepare::findSEHEHReturnPoints( } } -/// Ensure that all values live into and out of exception handlers are stored -/// in memory. -/// FIXME: This falls down when values are defined in one handler and live into -/// another handler. For example, a cleanup defines a value used only by a -/// catch handler. -void WinEHPrepare::demoteValuesLiveAcrossHandlers( - Function &F, SmallVectorImpl &LPads) { +void WinEHPrepare::identifyEHBlocks(Function &F, + SmallVectorImpl &LPads) { DEBUG(dbgs() << "Demoting values live across exception handlers in function " << F.getName() << '\n'); @@ -539,10 +557,6 @@ void WinEHPrepare::demoteValuesLiveAcrossHandlers( // - Exceptional blocks are blocks reachable from landingpads. Analysis does // not follow llvm.eh.endcatch blocks, which mark a transition from // exceptional to normal control. - SmallPtrSet NormalBlocks; - SmallPtrSet EHBlocks; - SetVector EHReturnBlocks; - SetVector Worklist; if (Personality == EHPersonality::MSVC_CXX) findCXXEHReturnPoints(F, EHReturnBlocks); @@ -565,6 +579,7 @@ void WinEHPrepare::demoteValuesLiveAcrossHandlers( // Normal blocks are the blocks reachable from the entry block and all EH // return points. + SetVector Worklist; Worklist = EHReturnBlocks; Worklist.insert(&F.getEntryBlock()); findReachableBlocks(NormalBlocks, Worklist, nullptr); @@ -586,6 +601,41 @@ void WinEHPrepare::demoteValuesLiveAcrossHandlers( dbgs() << " " << BB->getName() << '\n'; }); +} + +/// Ensure that all values live into and out of exception handlers are stored +/// in memory. +/// FIXME: This falls down when values are defined in one handler and live into +/// another handler. For example, a cleanup defines a value used only by a +/// catch handler. +void WinEHPrepare::demoteValuesLiveAcrossHandlers( + Function &F, SmallVectorImpl &LPads) { + DEBUG(dbgs() << "Demoting values live across exception handlers in function " + << F.getName() << '\n'); + + // identifyEHBlocks() should have been called before this function. + assert(!NormalBlocks.empty()); + + // Try to avoid demoting EH pointer and selector values. They get in the way + // of our pattern matching. + SmallPtrSet EHVals; + for (BasicBlock &BB : F) { + LandingPadInst *LP = BB.getLandingPadInst(); + if (!LP) + continue; + EHVals.insert(LP); + for (User *U : LP->users()) { + auto *EI = dyn_cast(U); + if (!EI) + continue; + EHVals.insert(EI); + for (User *U2 : EI->users()) { + if (auto *PN = dyn_cast(U2)) + EHVals.insert(PN); + } + } + } + SetVector ArgsToDemote; SetVector InstrsToDemote; for (BasicBlock &BB : F) { @@ -611,7 +661,11 @@ void WinEHPrepare::demoteValuesLiveAcrossHandlers( continue; } + // Don't demote EH values. auto *OpI = cast(Op); + if (EHVals.count(OpI)) + continue; + BasicBlock *OpBB = OpI->getParent(); // If a value is produced and consumed in the same BB, we don't need to // demote it. @@ -676,6 +730,7 @@ bool WinEHPrepare::prepareExceptionHandlers( return false; } + identifyEHBlocks(F, LPads); demoteValuesLiveAcrossHandlers(F, LPads); // These containers are used to re-map frame variables that are used in @@ -700,6 +755,24 @@ bool WinEHPrepare::prepareExceptionHandlers( F.getEntryBlock().getFirstInsertionPt()); } + // In order to handle the case where one outlined catch handler returns + // to a block within another outlined catch handler that would otherwise + // be unreachable, we need to outline the nested landing pad before we + // outline the landing pad which encloses it. + if (!isAsynchronousEHPersonality(Personality)) + std::sort(LPads.begin(), LPads.end(), + [this](LandingPadInst *const &L, LandingPadInst *const &R) { + return DT->properlyDominates(R->getParent(), L->getParent()); + }); + + // This container stores the llvm.eh.recover and IndirectBr instructions + // that make up the body of each landing pad after it has been outlined. + // We need to defer the population of the target list for the indirectbr + // until all landing pads have been outlined so that we can handle the + // case of blocks in the target that are reached only from nested + // landing pads. + SmallVector, 4> LPadImpls; + for (LandingPadInst *LPad : LPads) { // Look for evidence that this landingpad has already been processed. bool LPadHasActionList = false; @@ -773,7 +846,8 @@ bool WinEHPrepare::prepareExceptionHandlers( LPad->replaceAllUsesWith(UndefValue::get(LPad->getType())); // Rewrite uses of the exception pointer to loads of an alloca. - for (Instruction *E : SEHCodeUses) { + while (!SEHCodeUses.empty()) { + Instruction *E = SEHCodeUses.pop_back_val(); SmallVector Uses; for (Use &U : E->uses()) Uses.push_back(&U); @@ -781,13 +855,10 @@ bool WinEHPrepare::prepareExceptionHandlers( auto *I = cast(U->getUser()); if (isa(I)) continue; - LoadInst *LI; if (auto *Phi = dyn_cast(I)) - LI = new LoadInst(SEHExceptionCodeSlot, "sehcode", false, - Phi->getIncomingBlock(*U)); + SEHCodeUses.push_back(Phi); else - LI = new LoadInst(SEHExceptionCodeSlot, "sehcode", false, I); - U->set(LI); + U->set(new LoadInst(SEHExceptionCodeSlot, "sehcode", false, I)); } E->replaceAllUsesWith(UndefValue::get(E->getType())); E->eraseFromParent(); @@ -819,7 +890,6 @@ bool WinEHPrepare::prepareExceptionHandlers( CallInst *Recover = CallInst::Create(ActionIntrin, ActionArgs, "recover", LPadBB); - // Add an indirect branch listing possible successors of the catch handlers. SetVector ReturnTargets; for (ActionHandler *Action : Actions) { if (auto *CatchAction = dyn_cast(Action)) { @@ -831,6 +901,13 @@ bool WinEHPrepare::prepareExceptionHandlers( IndirectBrInst::Create(Recover, ReturnTargets.size(), LPadBB); for (BasicBlock *Target : ReturnTargets) Branch->addDestination(Target); + + if (!isAsynchronousEHPersonality(Personality)) { + // C++ EH must repopulate the targets later to handle the case of + // targets that are reached indirectly through nested landing pads. + LPadImpls.push_back(std::make_pair(Recover, Branch)); + } + } // End for each landingpad // If nothing got outlined, there is no more processing to be done. @@ -844,6 +921,50 @@ bool WinEHPrepare::prepareExceptionHandlers( completeNestedLandingPad(&F, LPadPair.first, LPadPair.second, FrameVarInfo); NestedLPtoOriginalLP.clear(); + // Update the indirectbr instructions' target lists if necessary. + SetVector CheckedTargets; + SmallVector, 4> ActionList; + for (auto &LPadImplPair : LPadImpls) { + IntrinsicInst *Recover = cast(LPadImplPair.first); + IndirectBrInst *Branch = LPadImplPair.second; + + // Get a list of handlers called by + parseEHActions(Recover, ActionList); + + // Add an indirect branch listing possible successors of the catch handlers. + SetVector ReturnTargets; + for (const auto &Action : ActionList) { + if (auto *CA = dyn_cast(Action.get())) { + Function *Handler = cast(CA->getHandlerBlockOrFunc()); + getPossibleReturnTargets(&F, Handler, ReturnTargets); + } + } + ActionList.clear(); + // Clear any targets we already knew about. + for (unsigned int I = 0, E = Branch->getNumDestinations(); I < E; ++I) { + BasicBlock *KnownTarget = Branch->getDestination(I); + if (ReturnTargets.count(KnownTarget)) + ReturnTargets.remove(KnownTarget); + } + for (BasicBlock *Target : ReturnTargets) { + Branch->addDestination(Target); + // The target may be a block that we excepted to get pruned. + // If it is, it may contain a call to llvm.eh.endcatch. + if (CheckedTargets.insert(Target)) { + // Earlier preparations guarantee that all calls to llvm.eh.endcatch + // will be followed by an unconditional branch. + auto *Br = dyn_cast(Target->getTerminator()); + if (Br && Br->isUnconditional() && + Br != Target->getFirstNonPHIOrDbgOrLifetime()) { + Instruction *Prev = Br->getPrevNode(); + if (match(cast(Prev), m_Intrinsic())) + Prev->eraseFromParent(); + } + } + } + } + LPadImpls.clear(); + F.addFnAttr("wineh-parent", F.getName()); // Delete any blocks that were only used by handlers that were outlined above. @@ -854,16 +975,16 @@ bool WinEHPrepare::prepareExceptionHandlers( Builder.SetInsertPoint(Entry->getFirstInsertionPt()); Function *FrameEscapeFn = - Intrinsic::getDeclaration(M, Intrinsic::frameescape); + Intrinsic::getDeclaration(M, Intrinsic::localescape); Function *RecoverFrameFn = - Intrinsic::getDeclaration(M, Intrinsic::framerecover); + Intrinsic::getDeclaration(M, Intrinsic::localrecover); SmallVector AllocasToEscape; - // Scan the entry block for an existing call to llvm.frameescape. We need to + // Scan the entry block for an existing call to llvm.localescape. We need to // keep escaping those objects. for (Instruction &I : F.front()) { auto *II = dyn_cast(&I); - if (II && II->getIntrinsicID() == Intrinsic::frameescape) { + if (II && II->getIntrinsicID() == Intrinsic::localescape) { auto Args = II->arg_operands(); AllocasToEscape.append(Args.begin(), Args.end()); II->eraseFromParent(); @@ -872,7 +993,7 @@ bool WinEHPrepare::prepareExceptionHandlers( } // Finally, replace all of the temporary allocas for frame variables used in - // the outlined handlers with calls to llvm.framerecover. + // the outlined handlers with calls to llvm.localrecover. for (auto &VarInfoEntry : FrameVarInfo) { Value *ParentVal = VarInfoEntry.first; TinyPtrVector &Allocas = VarInfoEntry.second; @@ -893,7 +1014,7 @@ bool WinEHPrepare::prepareExceptionHandlers( llvm::Value *FP = HandlerToParentFP[HandlerFn]; assert(FP); - // FIXME: Sink this framerecover into the blocks where it is used. + // FIXME: Sink this localrecover into the blocks where it is used. Builder.SetInsertPoint(TempAlloca); Builder.SetCurrentDebugLocation(TempAlloca->getDebugLoc()); Value *RecoverArgs[] = { @@ -915,16 +1036,23 @@ bool WinEHPrepare::prepareExceptionHandlers( } } // End for each FrameVarInfo entry. - // Insert 'call void (...)* @llvm.frameescape(...)' at the end of the entry + // Insert 'call void (...)* @llvm.localescape(...)' at the end of the entry // block. Builder.SetInsertPoint(&F.getEntryBlock().back()); Builder.CreateCall(FrameEscapeFn, AllocasToEscape); if (SEHExceptionCodeSlot) { - if (SEHExceptionCodeSlot->hasNUses(0)) - SEHExceptionCodeSlot->eraseFromParent(); - else if (isAllocaPromotable(SEHExceptionCodeSlot)) + if (isAllocaPromotable(SEHExceptionCodeSlot)) { + SmallPtrSet UserBlocks; + for (User *U : SEHExceptionCodeSlot->users()) { + if (auto *Inst = dyn_cast(U)) + UserBlocks.insert(Inst->getParent()); + } PromoteMemToReg(SEHExceptionCodeSlot, *DT); + // After the promotion, kill off dead instructions. + for (BasicBlock *BB : UserBlocks) + SimplifyInstructionsInBlock(BB, LibInfo); + } } // Clean up the handler action maps we created for this function @@ -934,7 +1062,11 @@ bool WinEHPrepare::prepareExceptionHandlers( CleanupHandlerMap.clear(); HandlerToParentFP.clear(); DT = nullptr; + LibInfo = nullptr; SEHExceptionCodeSlot = nullptr; + EHBlocks.clear(); + NormalBlocks.clear(); + EHReturnBlocks.clear(); return HandlersOutlined; } @@ -976,6 +1108,42 @@ void WinEHPrepare::promoteLandingPadValues(LandingPadInst *LPad) { RecursivelyDeleteTriviallyDeadInstructions(U); } +void WinEHPrepare::getPossibleReturnTargets(Function *ParentF, + Function *HandlerF, + SetVector &Targets) { + for (BasicBlock &BB : *HandlerF) { + // If the handler contains landing pads, check for any + // handlers that may return directly to a block in the + // parent function. + if (auto *LPI = BB.getLandingPadInst()) { + IntrinsicInst *Recover = cast(LPI->getNextNode()); + SmallVector, 4> ActionList; + parseEHActions(Recover, ActionList); + for (const auto &Action : ActionList) { + if (auto *CH = dyn_cast(Action.get())) { + Function *NestedF = cast(CH->getHandlerBlockOrFunc()); + getPossibleReturnTargets(ParentF, NestedF, Targets); + } + } + } + + auto *Ret = dyn_cast(BB.getTerminator()); + if (!Ret) + continue; + + // Handler functions must always return a block address. + BlockAddress *BA = cast(Ret->getReturnValue()); + + // If this is the handler for a nested landing pad, the + // return address may have been remapped to a block in the + // parent handler. We're not interested in those. + if (BA->getFunction() != ParentF) + continue; + + Targets.insert(BA->getBasicBlock()); + } +} + void WinEHPrepare::completeNestedLandingPad(Function *ParentFn, LandingPadInst *OutlinedLPad, const LandingPadInst *OriginalLPad, @@ -984,10 +1152,19 @@ void WinEHPrepare::completeNestedLandingPad(Function *ParentFn, // temporarily inserted as its terminator. LLVMContext &Context = ParentFn->getContext(); BasicBlock *OutlinedBB = OutlinedLPad->getParent(); - assert(isa(OutlinedBB->getTerminator())); - OutlinedBB->getTerminator()->eraseFromParent(); - // That should leave OutlinedLPad as the last instruction in its block. - assert(&OutlinedBB->back() == OutlinedLPad); + // If the nested landing pad was outlined before the landing pad that enclosed + // it, it will already be in outlined form. In that case, we just need to see + // if the returns and the enclosing branch instruction need to be updated. + IndirectBrInst *Branch = + dyn_cast(OutlinedBB->getTerminator()); + if (!Branch) { + // If the landing pad wasn't in outlined form, it should be a stub with + // an unreachable terminator. + assert(isa(OutlinedBB->getTerminator())); + OutlinedBB->getTerminator()->eraseFromParent(); + // That should leave OutlinedLPad as the last instruction in its block. + assert(&OutlinedBB->back() == OutlinedLPad); + } // The original landing pad will have already had its action intrinsic // built by the outlining loop. We need to clone that into the outlined @@ -1000,15 +1177,14 @@ void WinEHPrepare::completeNestedLandingPad(Function *ParentFn, ++II; // The instruction after the landing pad should now be a call to eh.actions. const Instruction *Recover = II; - assert(match(Recover, m_Intrinsic())); - IntrinsicInst *EHActions = cast(Recover->clone()); + const IntrinsicInst *EHActions = cast(Recover); - // Remap the exception variables into the outlined function. + // Remap the return target in the nested handler. SmallVector ActionTargets; - SmallVector ActionList; + SmallVector, 4> ActionList; parseEHActions(EHActions, ActionList); - for (auto *Action : ActionList) { - auto *Catch = dyn_cast(Action); + for (const auto &Action : ActionList) { + auto *Catch = dyn_cast(Action.get()); if (!Catch) continue; // The dyn_cast to function here selects C++ catch handlers and skips @@ -1030,7 +1206,7 @@ void WinEHPrepare::completeNestedLandingPad(Function *ParentFn, // should be a block that was outlined into OutlinedHandlerFn. assert(BA->getFunction() == ParentFn); - // Ignore targets that aren't part of OutlinedHandlerFn. + // Ignore targets that aren't part of an outlined handler function. if (!LPadTargetBlocks.count(BA->getBasicBlock())) continue; @@ -1046,15 +1222,26 @@ void WinEHPrepare::completeNestedLandingPad(Function *ParentFn, ActionTargets.push_back(NewBA); } } - DeleteContainerPointers(ActionList); ActionList.clear(); - OutlinedBB->getInstList().push_back(EHActions); - // Insert an indirect branch into the outlined landing pad BB. - IndirectBrInst *IBr = IndirectBrInst::Create(EHActions, 0, OutlinedBB); - // Add the previously collected action targets. - for (auto *Target : ActionTargets) - IBr->addDestination(Target->getBasicBlock()); + if (Branch) { + // If the landing pad was already in outlined form, just update its targets. + for (unsigned int I = Branch->getNumDestinations(); I > 0; --I) + Branch->removeDestination(I); + // Add the previously collected action targets. + for (auto *Target : ActionTargets) + Branch->addDestination(Target->getBasicBlock()); + } else { + // If the landing pad was previously stubbed out, fill in its outlined form. + IntrinsicInst *NewEHActions = cast(EHActions->clone()); + OutlinedBB->getInstList().push_back(NewEHActions); + + // Insert an indirect branch into the outlined landing pad BB. + IndirectBrInst *IBr = IndirectBrInst::Create(NewEHActions, 0, OutlinedBB); + // Add the previously collected action targets. + for (auto *Target : ActionTargets) + IBr->addDestination(Target->getBasicBlock()); + } } // This function examines a block to determine whether the block ends with a @@ -1100,8 +1287,7 @@ static bool isCatchBlock(BasicBlock *BB) { return false; } -static BasicBlock *createStubLandingPad(Function *Handler, - Value *PersonalityFn) { +static BasicBlock *createStubLandingPad(Function *Handler) { // FIXME: Finish this! LLVMContext &Context = Handler->getContext(); BasicBlock *StubBB = BasicBlock::Create(Context, "stub"); @@ -1110,11 +1296,11 @@ static BasicBlock *createStubLandingPad(Function *Handler, LandingPadInst *LPad = Builder.CreateLandingPad( llvm::StructType::get(Type::getInt8PtrTy(Context), Type::getInt32Ty(Context), nullptr), - PersonalityFn, 0); + 0); // Insert a call to llvm.eh.actions so that we don't try to outline this lpad. Function *ActionIntrin = Intrinsic::getDeclaration(Handler->getParent(), Intrinsic::eh_actions); - Builder.CreateCall(ActionIntrin, "recover"); + Builder.CreateCall(ActionIntrin, {}, "recover"); LPad->setCleanup(true); Builder.CreateUnreachable(); return StubBB; @@ -1125,8 +1311,7 @@ static BasicBlock *createStubLandingPad(Function *Handler, // landing pad if none is found. The code that generates the .xdata tables for // the handler needs at least one landing pad to identify the parent function's // personality. -void WinEHPrepare::addStubInvokeToHandlerIfNeeded(Function *Handler, - Value *PersonalityFn) { +void WinEHPrepare::addStubInvokeToHandlerIfNeeded(Function *Handler) { ReturnInst *Ret = nullptr; UnreachableInst *Unreached = nullptr; for (BasicBlock &BB : *Handler) { @@ -1158,7 +1343,7 @@ void WinEHPrepare::addStubInvokeToHandlerIfNeeded(Function *Handler, // parent block. We want to replace that with an invoke call, so we can // erase it now. OldRetBB->getTerminator()->eraseFromParent(); - BasicBlock *StubLandingPad = createStubLandingPad(Handler, PersonalityFn); + BasicBlock *StubLandingPad = createStubLandingPad(Handler); Function *F = Intrinsic::getDeclaration(Handler->getParent(), Intrinsic::donothing); InvokeInst::Create(F, NewRetBB, StubLandingPad, None, "", OldRetBB); @@ -1166,14 +1351,15 @@ void WinEHPrepare::addStubInvokeToHandlerIfNeeded(Function *Handler, // FIXME: Consider sinking this into lib/Target/X86 somehow. TargetLowering // usually doesn't build LLVM IR, so that's probably the wrong place. -Function *WinEHPrepare::createHandlerFunc(Type *RetTy, const Twine &Name, - Module *M, Value *&ParentFP) { +Function *WinEHPrepare::createHandlerFunc(Function *ParentFn, Type *RetTy, + const Twine &Name, Module *M, + Value *&ParentFP) { // x64 uses a two-argument prototype where the parent FP is the second // argument. x86 uses no arguments, just the incoming EBP value. LLVMContext &Context = M->getContext(); + Type *Int8PtrType = Type::getInt8PtrTy(Context); FunctionType *FnType; if (TheTriple.getArch() == Triple::x86_64) { - Type *Int8PtrType = Type::getInt8PtrTy(Context); Type *ArgTys[2] = {Int8PtrType, Int8PtrType}; FnType = FunctionType::get(RetTy, ArgTys, false); } else { @@ -1190,9 +1376,13 @@ Function *WinEHPrepare::createHandlerFunc(Type *RetTy, const Twine &Name, assert(M); Function *FrameAddressFn = Intrinsic::getDeclaration(M, Intrinsic::frameaddress); - Value *Args[1] = {ConstantInt::get(Type::getInt32Ty(Context), 1)}; - ParentFP = CallInst::Create(FrameAddressFn, Args, "parent_fp", - &Handler->getEntryBlock()); + Function *RecoverFPFn = + Intrinsic::getDeclaration(M, Intrinsic::x86_seh_recoverfp); + IRBuilder<> Builder(&Handler->getEntryBlock()); + Value *EBP = + Builder.CreateCall(FrameAddressFn, {Builder.getInt32(1)}, "ebp"); + Value *ParentI8Fn = Builder.CreateBitCast(ParentFn, Int8PtrType); + ParentFP = Builder.CreateCall(RecoverFPFn, {ParentI8Fn, EBP}); } return Handler; } @@ -1208,12 +1398,13 @@ bool WinEHPrepare::outlineHandler(ActionHandler *Action, Function *SrcFn, Value *ParentFP; Function *Handler; if (Action->getType() == Catch) { - Handler = createHandlerFunc(Int8PtrType, SrcFn->getName() + ".catch", M, + Handler = createHandlerFunc(SrcFn, Int8PtrType, SrcFn->getName() + ".catch", M, ParentFP); } else { - Handler = createHandlerFunc(Type::getVoidTy(Context), + Handler = createHandlerFunc(SrcFn, Type::getVoidTy(Context), SrcFn->getName() + ".cleanup", M, ParentFP); } + Handler->setPersonalityFn(SrcFn->getPersonalityFn()); HandlerToParentFP[Handler] = ParentFP; Handler->addFnAttr("wineh-parent", SrcFn->getName()); BasicBlock *Entry = &Handler->getEntryBlock(); @@ -1232,9 +1423,9 @@ bool WinEHPrepare::outlineHandler(ActionHandler *Action, Function *SrcFn, LPadMap.mapLandingPad(LPad); if (auto *CatchAction = dyn_cast(Action)) { Constant *Sel = CatchAction->getSelector(); - Director.reset(new WinEHCatchDirector(Handler, ParentFP, Sel, - VarInfo, LPadMap, - NestedLPtoOriginalLP)); + Director.reset(new WinEHCatchDirector(Handler, ParentFP, Sel, VarInfo, + LPadMap, NestedLPtoOriginalLP, DT, + EHBlocks)); LPadMap.remapEHValues(VMap, UndefValue::get(Int8PtrType), ConstantInt::get(Type::getInt32Ty(Context), 1)); } else { @@ -1291,7 +1482,7 @@ bool WinEHPrepare::outlineHandler(ActionHandler *Action, Function *SrcFn, ClonedEntryBB->eraseFromParent(); // Make sure we can identify the handler's personality later. - addStubInvokeToHandlerIfNeeded(Handler, LPad->getPersonalityFn()); + addStubInvokeToHandlerIfNeeded(Handler); if (auto *CatchAction = dyn_cast(Action)) { WinEHCatchDirector *CatchDirector = @@ -1359,7 +1550,7 @@ void WinEHPrepare::processSEHCatchHandler(CatchHandler *CatchAction, IRBuilder<> Builder(HandlerBB->getFirstInsertionPt()); Function *EHCodeFn = Intrinsic::getDeclaration( StartBB->getParent()->getParent(), Intrinsic::eh_exceptioncode); - Value *Code = Builder.CreateCall(EHCodeFn, "sehcode"); + Value *Code = Builder.CreateCall(EHCodeFn, {}, "sehcode"); Code = Builder.CreateIntToPtr(Code, SEHExceptionCodeSlot->getAllocatedType()); Builder.CreateStore(Code, SEHExceptionCodeSlot); CatchAction->setHandlerBlockOrFunc(BlockAddress::get(HandlerBB)); @@ -1426,9 +1617,8 @@ void LandingPadMap::remapEHValues(ValueToValueMapTy &VMap, Value *EHPtrValue, VMap[Extract] = SelectorValue; } -static bool isFrameAddressCall(const Value *V) { - return match(const_cast(V), - m_Intrinsic(m_SpecificInt(0))); +static bool isLocalAddressCall(const Value *V) { + return match(const_cast(V), m_Intrinsic()); } CloningDirector::CloningAction WinEHCloningDirectorBase::handleInstruction( @@ -1438,15 +1628,22 @@ CloningDirector::CloningAction WinEHCloningDirectorBase::handleInstruction( if (LPadMap.isLandingPadSpecificInst(Inst)) return CloningDirector::SkipInstruction; - // Nested landing pads will be cloned as stubs, with just the - // landingpad instruction and an unreachable instruction. When - // all landingpads have been outlined, we'll replace this with the - // llvm.eh.actions call and indirect branch created when the - // landing pad was outlined. + // Nested landing pads that have not already been outlined will be cloned as + // stubs, with just the landingpad instruction and an unreachable instruction. + // When all landingpads have been outlined, we'll replace this with the + // llvm.eh.actions call and indirect branch created when the landing pad was + // outlined. if (auto *LPad = dyn_cast(Inst)) { return handleLandingPad(VMap, LPad, NewBB); } + // Nested landing pads that have already been outlined will be cloned in their + // outlined form, but we need to intercept the ibr instruction to filter out + // targets that do not return to the handler we are outlining. + if (auto *IBr = dyn_cast(Inst)) { + return handleIndirectBr(VMap, IBr, NewBB); + } + if (auto *Invoke = dyn_cast(Inst)) return handleInvoke(VMap, Invoke, NewBB); @@ -1463,9 +1660,9 @@ CloningDirector::CloningAction WinEHCloningDirectorBase::handleInstruction( if (match(Inst, m_Intrinsic())) return handleTypeIdFor(VMap, Inst, NewBB); - // When outlining llvm.frameaddress(i32 0), remap that to the second argument, + // When outlining llvm.localaddress(), remap that to the second argument, // which is the FP of the parent. - if (isFrameAddressCall(Inst)) { + if (isLocalAddressCall(Inst)) { VMap[Inst] = ParentFP; return CloningDirector::SkipInstruction; } @@ -1476,6 +1673,20 @@ CloningDirector::CloningAction WinEHCloningDirectorBase::handleInstruction( CloningDirector::CloningAction WinEHCatchDirector::handleLandingPad( ValueToValueMapTy &VMap, const LandingPadInst *LPad, BasicBlock *NewBB) { + // If the instruction after the landing pad is a call to llvm.eh.actions + // the landing pad has already been outlined. In this case, we should + // clone it because it may return to a block in the handler we are + // outlining now that would otherwise be unreachable. The landing pads + // are sorted before outlining begins to enable this case to work + // properly. + const Instruction *NextI = LPad->getNextNode(); + if (match(NextI, m_Intrinsic())) + return CloningDirector::CloneInstruction; + + // If the landing pad hasn't been outlined yet, the landing pad we are + // outlining now does not dominate it and so it cannot return to a block + // in this handler. In that case, we can just insert a stub landing + // pad now and patch it up later. Instruction *NewInst = LPad->clone(); if (LPad->hasName()) NewInst->setName(LPad->getName()); @@ -1567,6 +1778,48 @@ CloningDirector::CloningAction WinEHCatchDirector::handleTypeIdFor( return CloningDirector::SkipInstruction; } +CloningDirector::CloningAction WinEHCatchDirector::handleIndirectBr( + ValueToValueMapTy &VMap, + const IndirectBrInst *IBr, + BasicBlock *NewBB) { + // If this indirect branch is not part of a landing pad block, just clone it. + const BasicBlock *ParentBB = IBr->getParent(); + if (!ParentBB->isLandingPad()) + return CloningDirector::CloneInstruction; + + // If it is part of a landing pad, we want to filter out target blocks + // that are not part of the handler we are outlining. + const LandingPadInst *LPad = ParentBB->getLandingPadInst(); + + // Save this correlation for later processing. + NestedLPtoOriginalLP[cast(VMap[LPad])] = LPad; + + // We should only get here for landing pads that have already been outlined. + assert(match(LPad->getNextNode(), m_Intrinsic())); + + // Copy the indirectbr, but only include targets that were previously + // identified as EH blocks and are dominated by the nested landing pad. + SetVector ReturnTargets; + for (int I = 0, E = IBr->getNumDestinations(); I < E; ++I) { + auto *TargetBB = IBr->getDestination(I); + if (EHBlocks.count(const_cast(TargetBB)) && + DT->dominates(ParentBB, TargetBB)) { + DEBUG(dbgs() << " Adding destination " << TargetBB->getName() << "\n"); + ReturnTargets.insert(TargetBB); + } + } + IndirectBrInst *NewBranch = + IndirectBrInst::Create(const_cast(IBr->getAddress()), + ReturnTargets.size(), NewBB); + for (auto *Target : ReturnTargets) + NewBranch->addDestination(const_cast(Target)); + + // The operands and targets of the branch instruction are remapped later + // because it is a terminator. Tell the cloning code to clone the + // blocks we just added to the target list. + return CloningDirector::CloneSuccessors; +} + CloningDirector::CloningAction WinEHCatchDirector::handleInvoke(ValueToValueMapTy &VMap, const InvokeInst *Invoke, BasicBlock *NewBB) { @@ -1656,6 +1909,14 @@ CloningDirector::CloningAction WinEHCleanupDirector::handleTypeIdFor( return CloningDirector::SkipInstruction; } +CloningDirector::CloningAction WinEHCleanupDirector::handleIndirectBr( + ValueToValueMapTy &VMap, + const IndirectBrInst *IBr, + BasicBlock *NewBB) { + // No special handling is required for cleanup cloning. + return CloningDirector::CloneInstruction; +} + CloningDirector::CloningAction WinEHCleanupDirector::handleInvoke( ValueToValueMapTy &VMap, const InvokeInst *Invoke, BasicBlock *NewBB) { // All invokes in cleanup handlers can be replaced with calls. @@ -1721,7 +1982,7 @@ Value *WinEHFrameVariableMaterializer::materializeValueFor(Value *V) { // If we're asked to materialize a static alloca, we temporarily create an // alloca in the outlined function and add this to the FrameVarInfo map. When // all the outlining is complete, we'll replace these temporary allocas with - // calls to llvm.framerecover. + // calls to llvm.localrecover. if (auto *AV = dyn_cast(V)) { assert(AV->isStaticAlloca() && "cannot materialize un-demoted dynamic alloca"); @@ -1732,7 +1993,12 @@ Value *WinEHFrameVariableMaterializer::materializeValueFor(Value *V) { } if (isa(V) || isa(V)) { - errs() << "Failed to demote instruction used in exception handler:\n"; + Function *Parent = isa(V) + ? cast(V)->getParent()->getParent() + : cast(V)->getParent(); + errs() + << "Failed to demote instruction used in exception handler of function " + << GlobalValue::getRealLinkageName(Parent->getName()) << ":\n"; errs() << " " << *V << '\n'; report_fatal_error("WinEHPrepare failed to demote instruction"); } @@ -1746,7 +2012,7 @@ void WinEHFrameVariableMaterializer::escapeCatchObject(Value *V) { // of a catch parameter, add a sentinel to the multimap to indicate that it's // used from another handler. This will prevent us from trying to sink the // alloca into the handler and ensure that the catch parameter is present in - // the call to llvm.frameescape. + // the call to llvm.localescape. FrameVarInfo[V].push_back(getCatchObjectSentinel()); } @@ -1988,16 +2254,16 @@ static void createCleanupHandler(LandingPadActions &Actions, static CallSite matchOutlinedFinallyCall(BasicBlock *BB, Instruction *MaybeCall) { // Look for finally blocks that Clang has already outlined for us. - // %fp = call i8* @llvm.frameaddress(i32 0) + // %fp = call i8* @llvm.localaddress() // call void @"fin$parent"(iN 1, i8* %fp) - if (isFrameAddressCall(MaybeCall) && MaybeCall != BB->getTerminator()) + if (isLocalAddressCall(MaybeCall) && MaybeCall != BB->getTerminator()) MaybeCall = MaybeCall->getNextNode(); CallSite FinallyCall(MaybeCall); if (!FinallyCall || FinallyCall.arg_size() != 2) return CallSite(); if (!match(FinallyCall.getArgument(0), m_SpecificInt(1))) return CallSite(); - if (!isFrameAddressCall(FinallyCall.getArgument(1))) + if (!isLocalAddressCall(FinallyCall.getArgument(1))) return CallSite(); return FinallyCall; } @@ -2056,7 +2322,7 @@ void WinEHPrepare::findCleanupHandlers(LandingPadActions &Actions, // value for this block but the value is a nullptr. This means that // we have previously analyzed the block and determined that it did // not contain any cleanup code. Based on the earlier analysis, we - // know the the block must end in either an unconditional branch, a + // know the block must end in either an unconditional branch, a // resume or a conditional branch that is predicated on a comparison // with a selector. Either the resume or the selector dispatch // would terminate the search for cleanup code, so the unconditional @@ -2155,40 +2421,43 @@ void WinEHPrepare::findCleanupHandlers(LandingPadActions &Actions, MaybeCall = MaybeCall->getNextNode(); } - // Look for outlined finally calls. - if (CallSite FinallyCall = matchOutlinedFinallyCall(BB, MaybeCall)) { - Function *Fin = FinallyCall.getCalledFunction(); - assert(Fin && "outlined finally call should be direct"); - auto *Action = new CleanupHandler(BB); - Action->setHandlerBlockOrFunc(Fin); - Actions.insertCleanupHandler(Action); - CleanupHandlerMap[BB] = Action; - DEBUG(dbgs() << " Found frontend-outlined finally call to " - << Fin->getName() << " in block " - << Action->getStartBlock()->getName() << "\n"); - - // Split the block if there were more interesting instructions and look - // for finally calls in the normal successor block. - BasicBlock *SuccBB = BB; - if (FinallyCall.getInstruction() != BB->getTerminator() && - FinallyCall.getInstruction()->getNextNode() != - BB->getTerminator()) { - SuccBB = - SplitBlock(BB, FinallyCall.getInstruction()->getNextNode(), DT); - } else { - if (FinallyCall.isInvoke()) { + // Look for outlined finally calls on x64, since those happen to match the + // prototype provided by the runtime. + if (TheTriple.getArch() == Triple::x86_64) { + if (CallSite FinallyCall = matchOutlinedFinallyCall(BB, MaybeCall)) { + Function *Fin = FinallyCall.getCalledFunction(); + assert(Fin && "outlined finally call should be direct"); + auto *Action = new CleanupHandler(BB); + Action->setHandlerBlockOrFunc(Fin); + Actions.insertCleanupHandler(Action); + CleanupHandlerMap[BB] = Action; + DEBUG(dbgs() << " Found frontend-outlined finally call to " + << Fin->getName() << " in block " + << Action->getStartBlock()->getName() << "\n"); + + // Split the block if there were more interesting instructions and + // look for finally calls in the normal successor block. + BasicBlock *SuccBB = BB; + if (FinallyCall.getInstruction() != BB->getTerminator() && + FinallyCall.getInstruction()->getNextNode() != + BB->getTerminator()) { SuccBB = - cast(FinallyCall.getInstruction())->getNormalDest(); + SplitBlock(BB, FinallyCall.getInstruction()->getNextNode(), DT); } else { - SuccBB = BB->getUniqueSuccessor(); - assert(SuccBB && - "splitOutlinedFinallyCalls didn't insert a branch"); + if (FinallyCall.isInvoke()) { + SuccBB = cast(FinallyCall.getInstruction()) + ->getNormalDest(); + } else { + SuccBB = BB->getUniqueSuccessor(); + assert(SuccBB && + "splitOutlinedFinallyCalls didn't insert a branch"); + } } + BB = SuccBB; + if (BB == EndBB) + return; + continue; } - BB = SuccBB; - if (BB == EndBB) - return; - continue; } } @@ -2221,8 +2490,11 @@ void WinEHPrepare::findCleanupHandlers(LandingPadActions &Actions, // This is a public function, declared in WinEHFuncInfo.h and is also // referenced by WinEHNumbering in FunctionLoweringInfo.cpp. -void llvm::parseEHActions(const IntrinsicInst *II, - SmallVectorImpl &Actions) { +void llvm::parseEHActions( + const IntrinsicInst *II, + SmallVectorImpl> &Actions) { + assert(II->getIntrinsicID() == Intrinsic::eh_actions && + "attempted to parse non eh.actions intrinsic"); for (unsigned I = 0, E = II->getNumArgOperands(); I != E;) { uint64_t ActionKind = cast(II->getArgOperand(I))->getZExtValue(); @@ -2232,19 +2504,393 @@ void llvm::parseEHActions(const IntrinsicInst *II, int64_t EHObjIndexVal = EHObjIndex->getSExtValue(); Constant *Handler = cast(II->getArgOperand(I + 3)); I += 4; - auto *CH = new CatchHandler(/*BB=*/nullptr, Selector, /*NextBB=*/nullptr); + auto CH = make_unique(/*BB=*/nullptr, Selector, + /*NextBB=*/nullptr); CH->setHandlerBlockOrFunc(Handler); CH->setExceptionVarIndex(EHObjIndexVal); - Actions.push_back(CH); + Actions.push_back(std::move(CH)); } else if (ActionKind == 0) { Constant *Handler = cast(II->getArgOperand(I + 1)); I += 2; - auto *CH = new CleanupHandler(/*BB=*/nullptr); + auto CH = make_unique(/*BB=*/nullptr); CH->setHandlerBlockOrFunc(Handler); - Actions.push_back(CH); + Actions.push_back(std::move(CH)); } else { llvm_unreachable("Expected either a catch or cleanup handler!"); } } std::reverse(Actions.begin(), Actions.end()); } + +namespace { +struct WinEHNumbering { + WinEHNumbering(WinEHFuncInfo &FuncInfo) : FuncInfo(FuncInfo), + CurrentBaseState(-1), NextState(0) {} + + WinEHFuncInfo &FuncInfo; + int CurrentBaseState; + int NextState; + + SmallVector, 4> HandlerStack; + SmallPtrSet VisitedHandlers; + + int currentEHNumber() const { + return HandlerStack.empty() ? CurrentBaseState : HandlerStack.back()->getEHState(); + } + + void createUnwindMapEntry(int ToState, ActionHandler *AH); + void createTryBlockMapEntry(int TryLow, int TryHigh, + ArrayRef Handlers); + void processCallSite(MutableArrayRef> Actions, + ImmutableCallSite CS); + void popUnmatchedActions(int FirstMismatch); + void calculateStateNumbers(const Function &F); + void findActionRootLPads(const Function &F); +}; +} + +void WinEHNumbering::createUnwindMapEntry(int ToState, ActionHandler *AH) { + WinEHUnwindMapEntry UME; + UME.ToState = ToState; + if (auto *CH = dyn_cast_or_null(AH)) + UME.Cleanup = cast(CH->getHandlerBlockOrFunc()); + else + UME.Cleanup = nullptr; + FuncInfo.UnwindMap.push_back(UME); +} + +void WinEHNumbering::createTryBlockMapEntry(int TryLow, int TryHigh, + ArrayRef Handlers) { + // See if we already have an entry for this set of handlers. + // This is using iterators rather than a range-based for loop because + // if we find the entry we're looking for we'll need the iterator to erase it. + int NumHandlers = Handlers.size(); + auto I = FuncInfo.TryBlockMap.begin(); + auto E = FuncInfo.TryBlockMap.end(); + for ( ; I != E; ++I) { + auto &Entry = *I; + if (Entry.HandlerArray.size() != (size_t)NumHandlers) + continue; + int N; + for (N = 0; N < NumHandlers; ++N) { + if (Entry.HandlerArray[N].Handler != Handlers[N]->getHandlerBlockOrFunc()) + break; // breaks out of inner loop + } + // If all the handlers match, this is what we were looking for. + if (N == NumHandlers) { + break; + } + } + + // If we found an existing entry for this set of handlers, extend the range + // but move the entry to the end of the map vector. The order of entries + // in the map is critical to the way that the runtime finds handlers. + // FIXME: Depending on what has happened with block ordering, this may + // incorrectly combine entries that should remain separate. + if (I != E) { + // Copy the existing entry. + WinEHTryBlockMapEntry Entry = *I; + Entry.TryLow = std::min(TryLow, Entry.TryLow); + Entry.TryHigh = std::max(TryHigh, Entry.TryHigh); + assert(Entry.TryLow <= Entry.TryHigh); + // Erase the old entry and add this one to the back. + FuncInfo.TryBlockMap.erase(I); + FuncInfo.TryBlockMap.push_back(Entry); + return; + } + + // If we didn't find an entry, create a new one. + WinEHTryBlockMapEntry TBME; + TBME.TryLow = TryLow; + TBME.TryHigh = TryHigh; + assert(TBME.TryLow <= TBME.TryHigh); + for (CatchHandler *CH : Handlers) { + WinEHHandlerType HT; + if (CH->getSelector()->isNullValue()) { + HT.Adjectives = 0x40; + HT.TypeDescriptor = nullptr; + } else { + auto *GV = cast(CH->getSelector()->stripPointerCasts()); + // Selectors are always pointers to GlobalVariables with 'struct' type. + // The struct has two fields, adjectives and a type descriptor. + auto *CS = cast(GV->getInitializer()); + HT.Adjectives = + cast(CS->getAggregateElement(0U))->getZExtValue(); + HT.TypeDescriptor = + cast(CS->getAggregateElement(1)->stripPointerCasts()); + } + HT.Handler = cast(CH->getHandlerBlockOrFunc()); + HT.CatchObjRecoverIdx = CH->getExceptionVarIndex(); + TBME.HandlerArray.push_back(HT); + } + FuncInfo.TryBlockMap.push_back(TBME); +} + +static void print_name(const Value *V) { +#ifndef NDEBUG + if (!V) { + DEBUG(dbgs() << "null"); + return; + } + + if (const auto *F = dyn_cast(V)) + DEBUG(dbgs() << F->getName()); + else + DEBUG(V->dump()); +#endif +} + +void WinEHNumbering::processCallSite( + MutableArrayRef> Actions, + ImmutableCallSite CS) { + DEBUG(dbgs() << "processCallSite (EH state = " << currentEHNumber() + << ") for: "); + print_name(CS ? CS.getCalledValue() : nullptr); + DEBUG(dbgs() << '\n'); + + DEBUG(dbgs() << "HandlerStack: \n"); + for (int I = 0, E = HandlerStack.size(); I < E; ++I) { + DEBUG(dbgs() << " "); + print_name(HandlerStack[I]->getHandlerBlockOrFunc()); + DEBUG(dbgs() << '\n'); + } + DEBUG(dbgs() << "Actions: \n"); + for (int I = 0, E = Actions.size(); I < E; ++I) { + DEBUG(dbgs() << " "); + print_name(Actions[I]->getHandlerBlockOrFunc()); + DEBUG(dbgs() << '\n'); + } + int FirstMismatch = 0; + for (int E = std::min(HandlerStack.size(), Actions.size()); FirstMismatch < E; + ++FirstMismatch) { + if (HandlerStack[FirstMismatch]->getHandlerBlockOrFunc() != + Actions[FirstMismatch]->getHandlerBlockOrFunc()) + break; + } + + // Remove unmatched actions from the stack and process their EH states. + popUnmatchedActions(FirstMismatch); + + DEBUG(dbgs() << "Pushing actions for CallSite: "); + print_name(CS ? CS.getCalledValue() : nullptr); + DEBUG(dbgs() << '\n'); + + bool LastActionWasCatch = false; + const LandingPadInst *LastRootLPad = nullptr; + for (size_t I = FirstMismatch; I != Actions.size(); ++I) { + // We can reuse eh states when pushing two catches for the same invoke. + bool CurrActionIsCatch = isa(Actions[I].get()); + auto *Handler = cast(Actions[I]->getHandlerBlockOrFunc()); + // Various conditions can lead to a handler being popped from the + // stack and re-pushed later. That shouldn't create a new state. + // FIXME: Can code optimization lead to re-used handlers? + if (FuncInfo.HandlerEnclosedState.count(Handler)) { + // If we already assigned the state enclosed by this handler re-use it. + Actions[I]->setEHState(FuncInfo.HandlerEnclosedState[Handler]); + continue; + } + const LandingPadInst* RootLPad = FuncInfo.RootLPad[Handler]; + if (CurrActionIsCatch && LastActionWasCatch && RootLPad == LastRootLPad) { + DEBUG(dbgs() << "setEHState for handler to " << currentEHNumber() << "\n"); + Actions[I]->setEHState(currentEHNumber()); + } else { + DEBUG(dbgs() << "createUnwindMapEntry(" << currentEHNumber() << ", "); + print_name(Actions[I]->getHandlerBlockOrFunc()); + DEBUG(dbgs() << ") with EH state " << NextState << "\n"); + createUnwindMapEntry(currentEHNumber(), Actions[I].get()); + DEBUG(dbgs() << "setEHState for handler to " << NextState << "\n"); + Actions[I]->setEHState(NextState); + NextState++; + } + HandlerStack.push_back(std::move(Actions[I])); + LastActionWasCatch = CurrActionIsCatch; + LastRootLPad = RootLPad; + } + + // This is used to defer numbering states for a handler until after the + // last time it appears in an invoke action list. + if (CS.isInvoke()) { + for (int I = 0, E = HandlerStack.size(); I < E; ++I) { + auto *Handler = cast(HandlerStack[I]->getHandlerBlockOrFunc()); + if (FuncInfo.LastInvoke[Handler] != cast(CS.getInstruction())) + continue; + FuncInfo.LastInvokeVisited[Handler] = true; + DEBUG(dbgs() << "Last invoke of "); + print_name(Handler); + DEBUG(dbgs() << " has been visited.\n"); + } + } + + DEBUG(dbgs() << "In EHState " << currentEHNumber() << " for CallSite: "); + print_name(CS ? CS.getCalledValue() : nullptr); + DEBUG(dbgs() << '\n'); +} + +void WinEHNumbering::popUnmatchedActions(int FirstMismatch) { + // Don't recurse while we are looping over the handler stack. Instead, defer + // the numbering of the catch handlers until we are done popping. + SmallVector PoppedCatches; + for (int I = HandlerStack.size() - 1; I >= FirstMismatch; --I) { + std::unique_ptr Handler = HandlerStack.pop_back_val(); + if (isa(Handler.get())) + PoppedCatches.push_back(cast(Handler.release())); + } + + int TryHigh = NextState - 1; + int LastTryLowIdx = 0; + for (int I = 0, E = PoppedCatches.size(); I != E; ++I) { + CatchHandler *CH = PoppedCatches[I]; + DEBUG(dbgs() << "Popped handler with state " << CH->getEHState() << "\n"); + if (I + 1 == E || CH->getEHState() != PoppedCatches[I + 1]->getEHState()) { + int TryLow = CH->getEHState(); + auto Handlers = + makeArrayRef(&PoppedCatches[LastTryLowIdx], I - LastTryLowIdx + 1); + DEBUG(dbgs() << "createTryBlockMapEntry(" << TryLow << ", " << TryHigh); + for (size_t J = 0; J < Handlers.size(); ++J) { + DEBUG(dbgs() << ", "); + print_name(Handlers[J]->getHandlerBlockOrFunc()); + } + DEBUG(dbgs() << ")\n"); + createTryBlockMapEntry(TryLow, TryHigh, Handlers); + LastTryLowIdx = I + 1; + } + } + + for (CatchHandler *CH : PoppedCatches) { + if (auto *F = dyn_cast(CH->getHandlerBlockOrFunc())) { + if (FuncInfo.LastInvokeVisited[F]) { + DEBUG(dbgs() << "Assigning base state " << NextState << " to "); + print_name(F); + DEBUG(dbgs() << '\n'); + FuncInfo.HandlerBaseState[F] = NextState; + DEBUG(dbgs() << "createUnwindMapEntry(" << currentEHNumber() + << ", null)\n"); + createUnwindMapEntry(currentEHNumber(), nullptr); + ++NextState; + calculateStateNumbers(*F); + } + else { + DEBUG(dbgs() << "Deferring handling of "); + print_name(F); + DEBUG(dbgs() << " until last invoke visited.\n"); + } + } + delete CH; + } +} + +void WinEHNumbering::calculateStateNumbers(const Function &F) { + auto I = VisitedHandlers.insert(&F); + if (!I.second) + return; // We've already visited this handler, don't renumber it. + + int OldBaseState = CurrentBaseState; + if (FuncInfo.HandlerBaseState.count(&F)) { + CurrentBaseState = FuncInfo.HandlerBaseState[&F]; + } + + size_t SavedHandlerStackSize = HandlerStack.size(); + + DEBUG(dbgs() << "Calculating state numbers for: " << F.getName() << '\n'); + SmallVector, 4> ActionList; + for (const BasicBlock &BB : F) { + for (const Instruction &I : BB) { + const auto *CI = dyn_cast(&I); + if (!CI || CI->doesNotThrow()) + continue; + processCallSite(None, CI); + } + const auto *II = dyn_cast(BB.getTerminator()); + if (!II) + continue; + const LandingPadInst *LPI = II->getLandingPadInst(); + auto *ActionsCall = dyn_cast(LPI->getNextNode()); + if (!ActionsCall) + continue; + parseEHActions(ActionsCall, ActionList); + if (ActionList.empty()) + continue; + processCallSite(ActionList, II); + ActionList.clear(); + FuncInfo.LandingPadStateMap[LPI] = currentEHNumber(); + DEBUG(dbgs() << "Assigning state " << currentEHNumber() + << " to landing pad at " << LPI->getParent()->getName() + << '\n'); + } + + // Pop any actions that were pushed on the stack for this function. + popUnmatchedActions(SavedHandlerStackSize); + + DEBUG(dbgs() << "Assigning max state " << NextState - 1 + << " to " << F.getName() << '\n'); + FuncInfo.CatchHandlerMaxState[&F] = NextState - 1; + + CurrentBaseState = OldBaseState; +} + +// This function follows the same basic traversal as calculateStateNumbers +// but it is necessary to identify the root landing pad associated +// with each action before we start assigning state numbers. +void WinEHNumbering::findActionRootLPads(const Function &F) { + auto I = VisitedHandlers.insert(&F); + if (!I.second) + return; // We've already visited this handler, don't revisit it. + + SmallVector, 4> ActionList; + for (const BasicBlock &BB : F) { + const auto *II = dyn_cast(BB.getTerminator()); + if (!II) + continue; + const LandingPadInst *LPI = II->getLandingPadInst(); + auto *ActionsCall = dyn_cast(LPI->getNextNode()); + if (!ActionsCall) + continue; + + assert(ActionsCall->getIntrinsicID() == Intrinsic::eh_actions); + parseEHActions(ActionsCall, ActionList); + if (ActionList.empty()) + continue; + for (int I = 0, E = ActionList.size(); I < E; ++I) { + if (auto *Handler + = dyn_cast(ActionList[I]->getHandlerBlockOrFunc())) { + FuncInfo.LastInvoke[Handler] = II; + // Don't replace the root landing pad if we previously saw this + // handler in a different function. + if (FuncInfo.RootLPad.count(Handler) && + FuncInfo.RootLPad[Handler]->getParent()->getParent() != &F) + continue; + DEBUG(dbgs() << "Setting root lpad for "); + print_name(Handler); + DEBUG(dbgs() << " to " << LPI->getParent()->getName() << '\n'); + FuncInfo.RootLPad[Handler] = LPI; + } + } + // Walk the actions again and look for nested handlers. This has to + // happen after all of the actions have been processed in the current + // function. + for (int I = 0, E = ActionList.size(); I < E; ++I) + if (auto *Handler + = dyn_cast(ActionList[I]->getHandlerBlockOrFunc())) + findActionRootLPads(*Handler); + ActionList.clear(); + } +} + +void llvm::calculateWinCXXEHStateNumbers(const Function *ParentFn, + WinEHFuncInfo &FuncInfo) { + // Return if it's already been done. + if (!FuncInfo.LandingPadStateMap.empty()) + return; + + WinEHNumbering Num(FuncInfo); + Num.findActionRootLPads(*ParentFn); + // The VisitedHandlers list is used by both findActionRootLPads and + // calculateStateNumbers, but both functions need to visit all handlers. + Num.VisitedHandlers.clear(); + Num.calculateStateNumbers(*ParentFn); + // Pop everything on the handler stack. + // It may be necessary to call this more than once because a handler can + // be pushed on the stack as a result of clearing the stack. + while (!Num.HandlerStack.empty()) + Num.processCallSite(None, ImmutableCallSite()); +}