+
+void WinEHFrameVariableMaterializer::escapeCatchObject(Value *V) {
+ // Catch parameter objects have to live in the parent frame. When we see a use
+ // 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.localescape.
+ FrameVarInfo[V].push_back(getCatchObjectSentinel());
+}
+
+// This function maps the catch and cleanup handlers that are reachable from the
+// specified landing pad. The landing pad sequence will have this basic shape:
+//
+// <cleanup handler>
+// <selector comparison>
+// <catch handler>
+// <cleanup handler>
+// <selector comparison>
+// <catch handler>
+// <cleanup handler>
+// ...
+//
+// Any of the cleanup slots may be absent. The cleanup slots may be occupied by
+// any arbitrary control flow, but all paths through the cleanup code must
+// eventually reach the next selector comparison and no path can skip to a
+// different selector comparisons, though some paths may terminate abnormally.
+// Therefore, we will use a depth first search from the start of any given
+// cleanup block and stop searching when we find the next selector comparison.
+//
+// If the landingpad instruction does not have a catch clause, we will assume
+// that any instructions other than selector comparisons and catch handlers can
+// be ignored. In practice, these will only be the boilerplate instructions.
+//
+// The catch handlers may also have any control structure, but we are only
+// interested in the start of the catch handlers, so we don't need to actually
+// follow the flow of the catch handlers. The start of the catch handlers can
+// be located from the compare instructions, but they can be skipped in the
+// flow by following the contrary branch.
+void WinEHPrepare::mapLandingPadBlocks(LandingPadInst *LPad,
+ LandingPadActions &Actions) {
+ unsigned int NumClauses = LPad->getNumClauses();
+ unsigned int HandlersFound = 0;
+ BasicBlock *BB = LPad->getParent();
+
+ DEBUG(dbgs() << "Mapping landing pad: " << BB->getName() << "\n");
+
+ if (NumClauses == 0) {
+ findCleanupHandlers(Actions, BB, nullptr);
+ return;
+ }
+
+ VisitedBlockSet VisitedBlocks;
+
+ while (HandlersFound != NumClauses) {
+ BasicBlock *NextBB = nullptr;
+
+ // Skip over filter clauses.
+ if (LPad->isFilter(HandlersFound)) {
+ ++HandlersFound;
+ continue;
+ }
+
+ // See if the clause we're looking for is a catch-all.
+ // If so, the catch begins immediately.
+ Constant *ExpectedSelector =
+ LPad->getClause(HandlersFound)->stripPointerCasts();
+ if (isa<ConstantPointerNull>(ExpectedSelector)) {
+ // The catch all must occur last.
+ assert(HandlersFound == NumClauses - 1);
+
+ // There can be additional selector dispatches in the call chain that we
+ // need to ignore.
+ BasicBlock *CatchBlock = nullptr;
+ Constant *Selector;
+ while (BB && isSelectorDispatch(BB, CatchBlock, Selector, NextBB)) {
+ DEBUG(dbgs() << " Found extra catch dispatch in block "
+ << CatchBlock->getName() << "\n");
+ BB = NextBB;
+ }
+
+ // Add the catch handler to the action list.
+ CatchHandler *Action = nullptr;
+ if (CatchHandlerMap.count(BB) && CatchHandlerMap[BB] != nullptr) {
+ // If the CatchHandlerMap already has an entry for this BB, re-use it.
+ Action = CatchHandlerMap[BB];
+ assert(Action->getSelector() == ExpectedSelector);
+ } else {
+ // We don't expect a selector dispatch, but there may be a call to
+ // llvm.eh.begincatch, which separates catch handling code from
+ // cleanup code in the same control flow. This call looks for the
+ // begincatch intrinsic.
+ Action = findCatchHandler(BB, NextBB, VisitedBlocks);
+ if (Action) {
+ // For C++ EH, check if there is any interesting cleanup code before
+ // we begin the catch. This is important because cleanups cannot
+ // rethrow exceptions but code called from catches can. For SEH, it
+ // isn't important if some finally code before a catch-all is executed
+ // out of line or after recovering from the exception.
+ if (Personality == EHPersonality::MSVC_CXX)
+ findCleanupHandlers(Actions, BB, BB);
+ } else {
+ // If an action was not found, it means that the control flows
+ // directly into the catch-all handler and there is no cleanup code.
+ // That's an expected situation and we must create a catch action.
+ // Since this is a catch-all handler, the selector won't actually
+ // appear in the code anywhere. ExpectedSelector here is the constant
+ // null ptr that we got from the landing pad instruction.
+ Action = new CatchHandler(BB, ExpectedSelector, nullptr);
+ CatchHandlerMap[BB] = Action;
+ }
+ }
+ Actions.insertCatchHandler(Action);
+ DEBUG(dbgs() << " Catch all handler at block " << BB->getName() << "\n");
+ ++HandlersFound;
+
+ // Once we reach a catch-all, don't expect to hit a resume instruction.
+ BB = nullptr;
+ break;
+ }
+
+ CatchHandler *CatchAction = findCatchHandler(BB, NextBB, VisitedBlocks);
+ assert(CatchAction);
+
+ // See if there is any interesting code executed before the dispatch.
+ findCleanupHandlers(Actions, BB, CatchAction->getStartBlock());
+
+ // When the source program contains multiple nested try blocks the catch
+ // handlers can get strung together in such a way that we can encounter
+ // a dispatch for a selector that we've already had a handler for.
+ if (CatchAction->getSelector()->stripPointerCasts() == ExpectedSelector) {
+ ++HandlersFound;
+
+ // Add the catch handler to the action list.
+ DEBUG(dbgs() << " Found catch dispatch in block "
+ << CatchAction->getStartBlock()->getName() << "\n");
+ Actions.insertCatchHandler(CatchAction);
+ } else {
+ // Under some circumstances optimized IR will flow unconditionally into a
+ // handler block without checking the selector. This can only happen if
+ // the landing pad has a catch-all handler and the handler for the
+ // preceeding catch clause is identical to the catch-call handler
+ // (typically an empty catch). In this case, the handler must be shared
+ // by all remaining clauses.
+ if (isa<ConstantPointerNull>(
+ CatchAction->getSelector()->stripPointerCasts())) {
+ DEBUG(dbgs() << " Applying early catch-all handler in block "
+ << CatchAction->getStartBlock()->getName()
+ << " to all remaining clauses.\n");
+ Actions.insertCatchHandler(CatchAction);
+ return;
+ }
+
+ DEBUG(dbgs() << " Found extra catch dispatch in block "
+ << CatchAction->getStartBlock()->getName() << "\n");
+ }
+
+ // Move on to the block after the catch handler.
+ BB = NextBB;
+ }
+
+ // If we didn't wind up in a catch-all, see if there is any interesting code
+ // executed before the resume.
+ findCleanupHandlers(Actions, BB, BB);
+
+ // It's possible that some optimization moved code into a landingpad that
+ // wasn't
+ // previously being used for cleanup. If that happens, we need to execute
+ // that
+ // extra code from a cleanup handler.
+ if (Actions.includesCleanup() && !LPad->isCleanup())
+ LPad->setCleanup(true);
+}
+
+// This function searches starting with the input block for the next
+// block that terminates with a branch whose condition is based on a selector
+// comparison. This may be the input block. See the mapLandingPadBlocks
+// comments for a discussion of control flow assumptions.
+//
+CatchHandler *WinEHPrepare::findCatchHandler(BasicBlock *BB,
+ BasicBlock *&NextBB,
+ VisitedBlockSet &VisitedBlocks) {
+ // See if we've already found a catch handler use it.
+ // Call count() first to avoid creating a null entry for blocks
+ // we haven't seen before.
+ if (CatchHandlerMap.count(BB) && CatchHandlerMap[BB] != nullptr) {
+ CatchHandler *Action = cast<CatchHandler>(CatchHandlerMap[BB]);
+ NextBB = Action->getNextBB();
+ return Action;
+ }
+
+ // VisitedBlocks applies only to the current search. We still
+ // need to consider blocks that we've visited while mapping other
+ // landing pads.
+ VisitedBlocks.insert(BB);
+
+ BasicBlock *CatchBlock = nullptr;
+ Constant *Selector = nullptr;
+
+ // If this is the first time we've visited this block from any landing pad
+ // look to see if it is a selector dispatch block.
+ if (!CatchHandlerMap.count(BB)) {
+ if (isSelectorDispatch(BB, CatchBlock, Selector, NextBB)) {
+ CatchHandler *Action = new CatchHandler(BB, Selector, NextBB);
+ CatchHandlerMap[BB] = Action;
+ return Action;
+ }
+ // If we encounter a block containing an llvm.eh.begincatch before we
+ // find a selector dispatch block, the handler is assumed to be
+ // reached unconditionally. This happens for catch-all blocks, but
+ // it can also happen for other catch handlers that have been combined
+ // with the catch-all handler during optimization.
+ if (isCatchBlock(BB)) {
+ PointerType *Int8PtrTy = Type::getInt8PtrTy(BB->getContext());
+ Constant *NullSelector = ConstantPointerNull::get(Int8PtrTy);
+ CatchHandler *Action = new CatchHandler(BB, NullSelector, nullptr);
+ CatchHandlerMap[BB] = Action;
+ return Action;
+ }
+ }
+
+ // Visit each successor, looking for the dispatch.
+ // FIXME: We expect to find the dispatch quickly, so this will probably
+ // work better as a breadth first search.
+ for (BasicBlock *Succ : successors(BB)) {
+ if (VisitedBlocks.count(Succ))
+ continue;
+
+ CatchHandler *Action = findCatchHandler(Succ, NextBB, VisitedBlocks);
+ if (Action)
+ return Action;
+ }
+ return nullptr;
+}
+
+// These are helper functions to combine repeated code from findCleanupHandlers.
+static void createCleanupHandler(LandingPadActions &Actions,
+ CleanupHandlerMapTy &CleanupHandlerMap,
+ BasicBlock *BB) {
+ CleanupHandler *Action = new CleanupHandler(BB);
+ CleanupHandlerMap[BB] = Action;
+ Actions.insertCleanupHandler(Action);
+ DEBUG(dbgs() << " Found cleanup code in block "
+ << Action->getStartBlock()->getName() << "\n");
+}
+
+static CallSite matchOutlinedFinallyCall(BasicBlock *BB,
+ Instruction *MaybeCall) {
+ // Look for finally blocks that Clang has already outlined for us.
+ // %fp = call i8* @llvm.localaddress()
+ // call void @"fin$parent"(iN 1, i8* %fp)
+ 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 (!isLocalAddressCall(FinallyCall.getArgument(1)))
+ return CallSite();
+ return FinallyCall;
+}
+
+static BasicBlock *followSingleUnconditionalBranches(BasicBlock *BB) {
+ // Skip single ubr blocks.
+ while (BB->getFirstNonPHIOrDbg() == BB->getTerminator()) {
+ auto *Br = dyn_cast<BranchInst>(BB->getTerminator());
+ if (Br && Br->isUnconditional())
+ BB = Br->getSuccessor(0);
+ else
+ return BB;
+ }
+ return BB;
+}
+
+// This function searches starting with the input block for the next block that
+// contains code that is not part of a catch handler and would not be eliminated
+// during handler outlining.
+//
+void WinEHPrepare::findCleanupHandlers(LandingPadActions &Actions,
+ BasicBlock *StartBB, BasicBlock *EndBB) {
+ // Here we will skip over the following:
+ //
+ // landing pad prolog:
+ //
+ // Unconditional branches
+ //
+ // Selector dispatch
+ //
+ // Resume pattern
+ //
+ // Anything else marks the start of an interesting block
+
+ BasicBlock *BB = StartBB;
+ // Anything other than an unconditional branch will kick us out of this loop
+ // one way or another.
+ while (BB) {
+ BB = followSingleUnconditionalBranches(BB);
+ // If we've already scanned this block, don't scan it again. If it is
+ // a cleanup block, there will be an action in the CleanupHandlerMap.
+ // If we've scanned it and it is not a cleanup block, there will be a
+ // nullptr in the CleanupHandlerMap. If we have not scanned it, there will
+ // be no entry in the CleanupHandlerMap. We must call count() first to
+ // avoid creating a null entry for blocks we haven't scanned.
+ if (CleanupHandlerMap.count(BB)) {
+ if (auto *Action = CleanupHandlerMap[BB]) {
+ Actions.insertCleanupHandler(Action);
+ DEBUG(dbgs() << " Found cleanup code in block "
+ << Action->getStartBlock()->getName() << "\n");
+ // FIXME: This cleanup might chain into another, and we need to discover
+ // that.
+ return;
+ } else {
+ // Here we handle the case where the cleanup handler map contains a
+ // 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 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
+ // branch is the only case for which we might need to continue
+ // searching.
+ BasicBlock *SuccBB = followSingleUnconditionalBranches(BB);
+ if (SuccBB == BB || SuccBB == EndBB)
+ return;
+ BB = SuccBB;
+ continue;
+ }
+ }
+
+ // Create an entry in the cleanup handler map for this block. Initially
+ // we create an entry that says this isn't a cleanup block. If we find
+ // cleanup code, the caller will replace this entry.
+ CleanupHandlerMap[BB] = nullptr;
+
+ TerminatorInst *Terminator = BB->getTerminator();
+
+ // Landing pad blocks have extra instructions we need to accept.
+ LandingPadMap *LPadMap = nullptr;
+ if (BB->isLandingPad()) {
+ LandingPadInst *LPad = BB->getLandingPadInst();
+ LPadMap = &LPadMaps[LPad];
+ if (!LPadMap->isInitialized())
+ LPadMap->mapLandingPad(LPad);
+ }
+
+ // Look for the bare resume pattern:
+ // %lpad.val1 = insertvalue { i8*, i32 } undef, i8* %exn, 0
+ // %lpad.val2 = insertvalue { i8*, i32 } %lpad.val1, i32 %sel, 1
+ // resume { i8*, i32 } %lpad.val2
+ if (auto *Resume = dyn_cast<ResumeInst>(Terminator)) {
+ InsertValueInst *Insert1 = nullptr;
+ InsertValueInst *Insert2 = nullptr;
+ Value *ResumeVal = Resume->getOperand(0);
+ // If the resume value isn't a phi or landingpad value, it should be a
+ // series of insertions. Identify them so we can avoid them when scanning
+ // for cleanups.
+ if (!isa<PHINode>(ResumeVal) && !isa<LandingPadInst>(ResumeVal)) {
+ Insert2 = dyn_cast<InsertValueInst>(ResumeVal);
+ if (!Insert2)
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
+ Insert1 = dyn_cast<InsertValueInst>(Insert2->getAggregateOperand());
+ if (!Insert1)
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
+ }
+ for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
+ II != IE; ++II) {
+ Instruction *Inst = II;
+ if (LPadMap && LPadMap->isLandingPadSpecificInst(Inst))
+ continue;
+ if (Inst == Insert1 || Inst == Insert2 || Inst == Resume)
+ continue;
+ if (!Inst->hasOneUse() ||
+ (Inst->user_back() != Insert1 && Inst->user_back() != Insert2)) {
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
+ }
+ }
+ return;
+ }
+
+ BranchInst *Branch = dyn_cast<BranchInst>(Terminator);
+ if (Branch && Branch->isConditional()) {
+ // Look for the selector dispatch.
+ // %2 = call i32 @llvm.eh.typeid.for(i8* bitcast (i8** @_ZTIf to i8*))
+ // %matches = icmp eq i32 %sel, %2
+ // br i1 %matches, label %catch14, label %eh.resume
+ CmpInst *Compare = dyn_cast<CmpInst>(Branch->getCondition());
+ if (!Compare || !Compare->isEquality())
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
+ for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
+ II != IE; ++II) {
+ Instruction *Inst = II;
+ if (LPadMap && LPadMap->isLandingPadSpecificInst(Inst))
+ continue;
+ if (Inst == Compare || Inst == Branch)
+ continue;
+ if (match(Inst, m_Intrinsic<Intrinsic::eh_typeid_for>()))
+ continue;
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
+ }
+ // The selector dispatch block should always terminate our search.
+ assert(BB == EndBB);
+ return;
+ }
+
+ if (isAsynchronousEHPersonality(Personality)) {
+ // If this is a landingpad block, split the block at the first non-landing
+ // pad instruction.
+ Instruction *MaybeCall = BB->getFirstNonPHIOrDbg();
+ if (LPadMap) {
+ while (MaybeCall != BB->getTerminator() &&
+ LPadMap->isLandingPadSpecificInst(MaybeCall))
+ MaybeCall = MaybeCall->getNextNode();
+ }
+
+ // 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 =
+ SplitBlock(BB, FinallyCall.getInstruction()->getNextNode(), DT);
+ } else {
+ if (FinallyCall.isInvoke()) {
+ SuccBB = cast<InvokeInst>(FinallyCall.getInstruction())
+ ->getNormalDest();
+ } else {
+ SuccBB = BB->getUniqueSuccessor();
+ assert(SuccBB &&
+ "splitOutlinedFinallyCalls didn't insert a branch");
+ }
+ }
+ BB = SuccBB;
+ if (BB == EndBB)
+ return;
+ continue;
+ }
+ }
+ }
+
+ // Anything else is either a catch block or interesting cleanup code.
+ for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
+ II != IE; ++II) {
+ Instruction *Inst = II;
+ if (LPadMap && LPadMap->isLandingPadSpecificInst(Inst))
+ continue;
+ // Unconditional branches fall through to this loop.
+ if (Inst == Branch)
+ continue;
+ // If this is a catch block, there is no cleanup code to be found.
+ if (match(Inst, m_Intrinsic<Intrinsic::eh_begincatch>()))
+ return;
+ // If this a nested landing pad, it may contain an endcatch call.
+ if (match(Inst, m_Intrinsic<Intrinsic::eh_endcatch>()))
+ return;
+ // Anything else makes this interesting cleanup code.
+ return createCleanupHandler(Actions, CleanupHandlerMap, BB);
+ }
+
+ // Only unconditional branches in empty blocks should get this far.
+ assert(Branch && Branch->isUnconditional());
+ if (BB == EndBB)
+ return;
+ BB = Branch->getSuccessor(0);
+ }
+}
+
+// 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<std::unique_ptr<ActionHandler>> &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<ConstantInt>(II->getArgOperand(I))->getZExtValue();
+ if (ActionKind == /*catch=*/1) {
+ auto *Selector = cast<Constant>(II->getArgOperand(I + 1));
+ ConstantInt *EHObjIndex = cast<ConstantInt>(II->getArgOperand(I + 2));
+ int64_t EHObjIndexVal = EHObjIndex->getSExtValue();
+ Constant *Handler = cast<Constant>(II->getArgOperand(I + 3));
+ I += 4;
+ auto CH = make_unique<CatchHandler>(/*BB=*/nullptr, Selector,
+ /*NextBB=*/nullptr);
+ CH->setHandlerBlockOrFunc(Handler);
+ CH->setExceptionVarIndex(EHObjIndexVal);
+ Actions.push_back(std::move(CH));
+ } else if (ActionKind == 0) {
+ Constant *Handler = cast<Constant>(II->getArgOperand(I + 1));
+ I += 2;
+ auto CH = make_unique<CleanupHandler>(/*BB=*/nullptr);
+ CH->setHandlerBlockOrFunc(Handler);
+ 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<std::unique_ptr<ActionHandler>, 4> HandlerStack;
+ SmallPtrSet<const Function *, 4> VisitedHandlers;
+
+ int currentEHNumber() const {
+ return HandlerStack.empty() ? CurrentBaseState : HandlerStack.back()->getEHState();
+ }
+
+ void createUnwindMapEntry(int ToState, ActionHandler *AH);
+ void createTryBlockMapEntry(int TryLow, int TryHigh,
+ ArrayRef<CatchHandler *> Handlers);
+ void processCallSite(MutableArrayRef<std::unique_ptr<ActionHandler>> 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<CleanupHandler>(AH))
+ UME.Cleanup = cast<Function>(CH->getHandlerBlockOrFunc());
+ else
+ UME.Cleanup = nullptr;
+ FuncInfo.UnwindMap.push_back(UME);
+}
+
+void WinEHNumbering::createTryBlockMapEntry(int TryLow, int TryHigh,
+ ArrayRef<CatchHandler *> 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<GlobalVariable>(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<ConstantStruct>(GV->getInitializer());
+ HT.Adjectives =
+ cast<ConstantInt>(CS->getAggregateElement(0U))->getZExtValue();
+ HT.TypeDescriptor =
+ cast<GlobalVariable>(CS->getAggregateElement(1)->stripPointerCasts());
+ }
+ HT.Handler = cast<Function>(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<Function>(V))
+ DEBUG(dbgs() << F->getName());
+ else
+ DEBUG(V->dump());
+#endif
+}
+
+void WinEHNumbering::processCallSite(
+ MutableArrayRef<std::unique_ptr<ActionHandler>> 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<CatchHandler>(Actions[I].get());
+ auto *Handler = cast<Function>(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<Function>(HandlerStack[I]->getHandlerBlockOrFunc());
+ if (FuncInfo.LastInvoke[Handler] != cast<InvokeInst>(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<CatchHandler *, 4> PoppedCatches;
+ for (int I = HandlerStack.size() - 1; I >= FirstMismatch; --I) {
+ std::unique_ptr<ActionHandler> Handler = HandlerStack.pop_back_val();
+ if (isa<CatchHandler>(Handler.get()))
+ PoppedCatches.push_back(cast<CatchHandler>(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<Function>(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<std::unique_ptr<ActionHandler>, 4> ActionList;
+ for (const BasicBlock &BB : F) {
+ for (const Instruction &I : BB) {
+ const auto *CI = dyn_cast<CallInst>(&I);
+ if (!CI || CI->doesNotThrow())
+ continue;
+ processCallSite(None, CI);
+ }
+ const auto *II = dyn_cast<InvokeInst>(BB.getTerminator());
+ if (!II)
+ continue;
+ const LandingPadInst *LPI = II->getLandingPadInst();
+ auto *ActionsCall = dyn_cast<IntrinsicInst>(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<std::unique_ptr<ActionHandler>, 4> ActionList;
+ for (const BasicBlock &BB : F) {
+ const auto *II = dyn_cast<InvokeInst>(BB.getTerminator());
+ if (!II)
+ continue;
+ const LandingPadInst *LPI = II->getLandingPadInst();
+ auto *ActionsCall = dyn_cast<IntrinsicInst>(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<Function>(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<Function>(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());
+}