#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PatternMatch.h"
+#include "llvm/MC/MCSymbol.h"
#include "llvm/Pass.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/PromoteMemToReg.h"
+#include "llvm/Transforms/Utils/SSAUpdater.h"
#include <memory>
using namespace llvm;
#define DEBUG_TYPE "winehprepare"
+static cl::opt<bool> DisableDemotion(
+ "disable-demotion", cl::Hidden,
+ cl::desc(
+ "Clone multicolor basic blocks but do not demote cross funclet values"),
+ cl::init(false));
+
+static cl::opt<bool> DisableCleanups(
+ "disable-cleanups", cl::Hidden,
+ cl::desc("Do not remove implausible terminators or other similar cleanups"),
+ cl::init(false));
+
namespace {
// This map is used to model frame variable usage during outlining, to
Function &F);
bool prepareExplicitEH(Function &F,
SmallVectorImpl<BasicBlock *> &EntryBlocks);
+ void replaceTerminatePadWithCleanup(Function &F);
void colorFunclets(Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks);
+ void demotePHIsOnFunclets(Function &F);
+ void demoteUsesBetweenFunclets(Function &F);
+ void demoteArgumentUses(Function &F);
+ void cloneCommonBlocks(Function &F,
+ SmallVectorImpl<BasicBlock *> &EntryBlocks);
+ void removeImplausibleTerminators(Function &F);
+ void cleanupPreparedFunclets(Function &F);
+ void verifyPreparedFunclets(Function &F);
Triple TheTriple;
return new WinEHPrepare(TM);
}
+static bool
+findExceptionalConstructs(Function &Fn,
+ SmallVectorImpl<LandingPadInst *> &LPads,
+ SmallVectorImpl<ResumeInst *> &Resumes,
+ SmallVectorImpl<BasicBlock *> &EntryBlocks) {
+ bool ForExplicitEH = false;
+ for (BasicBlock &BB : Fn) {
+ Instruction *First = BB.getFirstNonPHI();
+ if (auto *LP = dyn_cast<LandingPadInst>(First)) {
+ LPads.push_back(LP);
+ } else if (First->isEHPad()) {
+ if (!ForExplicitEH)
+ EntryBlocks.push_back(&Fn.getEntryBlock());
+ if (!isa<CatchEndPadInst>(First) && !isa<CleanupEndPadInst>(First))
+ EntryBlocks.push_back(&BB);
+ ForExplicitEH = true;
+ }
+ if (auto *Resume = dyn_cast<ResumeInst>(BB.getTerminator()))
+ Resumes.push_back(Resume);
+ }
+ return ForExplicitEH;
+}
+
bool WinEHPrepare::runOnFunction(Function &Fn) {
if (!Fn.hasPersonalityFn())
return false;
// Classify the personality to see what kind of preparation we need.
Personality = classifyEHPersonality(Fn.getPersonalityFn());
- // Do nothing if this is not an MSVC personality.
- if (!isMSVCEHPersonality(Personality))
+ // Do nothing if this is not a funclet-based personality.
+ if (!isFuncletEHPersonality(Personality))
return false;
SmallVector<LandingPadInst *, 4> LPads;
SmallVector<ResumeInst *, 4> Resumes;
SmallVector<BasicBlock *, 4> EntryBlocks;
- bool ForExplicitEH = false;
- for (BasicBlock &BB : Fn) {
- Instruction *First = BB.getFirstNonPHI();
- if (auto *LP = dyn_cast<LandingPadInst>(First)) {
- LPads.push_back(LP);
- } else if (First->isEHPad()) {
- if (!ForExplicitEH)
- EntryBlocks.push_back(&Fn.getEntryBlock());
- if (!isa<CatchEndPadInst>(First))
- EntryBlocks.push_back(&BB);
- ForExplicitEH = true;
- }
- if (auto *Resume = dyn_cast<ResumeInst>(BB.getTerminator()))
- Resumes.push_back(Resume);
- }
+ bool ForExplicitEH =
+ findExceptionalConstructs(Fn, LPads, Resumes, EntryBlocks);
if (ForExplicitEH)
return prepareExplicitEH(Fn, EntryBlocks);
}
IRBuilder<> Builder(HandlerBB->getFirstInsertionPt());
Function *EHCodeFn = Intrinsic::getDeclaration(
- StartBB->getParent()->getParent(), Intrinsic::eh_exceptioncode);
+ StartBB->getParent()->getParent(), Intrinsic::eh_exceptioncode_old);
Value *Code = Builder.CreateCall(EHCodeFn, {}, "sehcode");
Code = Builder.CreateIntToPtr(Code, SEHExceptionCodeSlot->getAllocatedType());
Builder.CreateStore(Code, SEHExceptionCodeSlot);
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);
-};
-}
-
static int addUnwindMapEntry(WinEHFuncInfo &FuncInfo, int ToState,
const Value *V) {
WinEHUnwindMapEntry UME;
for (const CatchPadInst *CPI : Handlers) {
WinEHHandlerType HT;
Constant *TypeInfo = cast<Constant>(CPI->getArgOperand(0));
- if (TypeInfo->isNullValue()) {
- HT.Adjectives = 0x40;
+ if (TypeInfo->isNullValue())
HT.TypeDescriptor = nullptr;
- } else {
- auto *GV = cast<GlobalVariable>(TypeInfo->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 = CPI->getNormalDest();
- HT.HandlerMBB = nullptr;
- // FIXME: Pass CPI->getArgOperand(1).
- HT.CatchObjRecoverIdx = -1;
- TBME.HandlerArray.push_back(HT);
- }
- FuncInfo.TryBlockMap.push_back(TBME);
-}
-
-void WinEHNumbering::createUnwindMapEntry(int ToState, ActionHandler *AH) {
- Value *V = nullptr;
- if (auto *CH = dyn_cast_or_null<CleanupHandler>(AH))
- V = cast<Function>(CH->getHandlerBlockOrFunc());
- addUnwindMapEntry(FuncInfo, ToState, V);
-}
-
-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.HandlerMBB = nullptr;
- HT.CatchObjRecoverIdx = CH->getExceptionVarIndex();
+ else
+ HT.TypeDescriptor = cast<GlobalVariable>(TypeInfo->stripPointerCasts());
+ HT.Adjectives = cast<ConstantInt>(CPI->getArgOperand(1))->getZExtValue();
+ HT.Handler = CPI->getParent();
+ HT.CatchObjRecoverIdx = -2;
+ if (isa<ConstantPointerNull>(CPI->getArgOperand(2)))
+ HT.CatchObj.Alloca = nullptr;
+ else
+ HT.CatchObj.Alloca = cast<AllocaInst>(CPI->getArgOperand(2));
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.EHPadStateMap[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();
- }
+static const CatchPadInst *getSingleCatchPadPredecessor(const BasicBlock *BB) {
+ for (const BasicBlock *PredBlock : predecessors(BB))
+ if (auto *CPI = dyn_cast<CatchPadInst>(PredBlock->getFirstNonPHI()))
+ return CPI;
+ return nullptr;
}
-static const BasicBlock *getSingleCatchPadPredecessor(const BasicBlock &BB) {
- for (const BasicBlock *PredBlock : predecessors(&BB))
- if (isa<CatchPadInst>(PredBlock->getFirstNonPHI()))
- return PredBlock;
- return nullptr;
+/// Find all the catchpads that feed directly into the catchendpad. Frontends
+/// using this personality should ensure that each catchendpad and catchpad has
+/// one or zero catchpad predecessors.
+///
+/// The following C++ generates the IR after it:
+/// try {
+/// } catch (A) {
+/// } catch (B) {
+/// }
+///
+/// IR:
+/// %catchpad.A
+/// catchpad [i8* A typeinfo]
+/// to label %catch.A unwind label %catchpad.B
+/// %catchpad.B
+/// catchpad [i8* B typeinfo]
+/// to label %catch.B unwind label %endcatches
+/// %endcatches
+/// catchendblock unwind to caller
+static void
+findCatchPadsForCatchEndPad(const BasicBlock *CatchEndBB,
+ SmallVectorImpl<const CatchPadInst *> &Handlers) {
+ const CatchPadInst *CPI = getSingleCatchPadPredecessor(CatchEndBB);
+ while (CPI) {
+ Handlers.push_back(CPI);
+ CPI = getSingleCatchPadPredecessor(CPI->getParent());
+ }
+ // We've pushed these back into reverse source order. Reverse them to get
+ // the list back into source order.
+ std::reverse(Handlers.begin(), Handlers.end());
}
// Given BB which ends in an unwind edge, return the EHPad that this BB belongs
const TerminatorInst *TI = BB->getTerminator();
if (isa<InvokeInst>(TI))
return nullptr;
- if (isa<CatchPadInst>(TI) || isa<CatchEndPadInst>(TI) ||
- isa<TerminatePadInst>(TI))
+ if (TI->isEHPad())
return BB;
return cast<CleanupReturnInst>(TI)->getCleanupPad()->getParent();
}
-static void calculateExplicitStateNumbers(WinEHFuncInfo &FuncInfo,
- const BasicBlock &BB,
- int ParentState) {
+static void calculateExplicitCXXStateNumbers(WinEHFuncInfo &FuncInfo,
+ const BasicBlock &BB,
+ int ParentState) {
assert(BB.isEHPad());
const Instruction *FirstNonPHI = BB.getFirstNonPHI();
// All catchpad instructions will be handled when we process their
return;
if (isa<CatchEndPadInst>(FirstNonPHI)) {
- const BasicBlock *TryPad = &BB;
- const BasicBlock *LastTryPad = nullptr;
SmallVector<const CatchPadInst *, 2> Handlers;
- do {
- LastTryPad = TryPad;
- TryPad = getSingleCatchPadPredecessor(*TryPad);
- if (TryPad)
- Handlers.push_back(cast<CatchPadInst>(TryPad->getFirstNonPHI()));
- } while (TryPad);
- // We've pushed these back into reverse source order. Reverse them to get
- // the list back into source order.
- std::reverse(Handlers.begin(), Handlers.end());
+ findCatchPadsForCatchEndPad(&BB, Handlers);
+ const BasicBlock *FirstTryPad = Handlers.front()->getParent();
int TryLow = addUnwindMapEntry(FuncInfo, ParentState, nullptr);
FuncInfo.EHPadStateMap[Handlers.front()] = TryLow;
- for (const BasicBlock *PredBlock : predecessors(LastTryPad))
+ for (const BasicBlock *PredBlock : predecessors(FirstTryPad))
if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
- calculateExplicitStateNumbers(FuncInfo, *PredBlock, TryLow);
+ calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, TryLow);
int CatchLow = addUnwindMapEntry(FuncInfo, ParentState, nullptr);
+
+ // catchpads are separate funclets in C++ EH due to the way rethrow works.
+ // In SEH, they aren't, so no invokes will unwind to the catchendpad.
FuncInfo.EHPadStateMap[FirstNonPHI] = CatchLow;
int TryHigh = CatchLow - 1;
for (const BasicBlock *PredBlock : predecessors(&BB))
if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
- calculateExplicitStateNumbers(FuncInfo, *PredBlock, CatchLow);
+ calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, CatchLow);
int CatchHigh = FuncInfo.getLastStateNumber();
addTryBlockMapEntry(FuncInfo, TryLow, TryHigh, CatchHigh, Handlers);
- DEBUG(dbgs() << "TryLow[" << LastTryPad->getName() << "]: " << TryLow
+ DEBUG(dbgs() << "TryLow[" << FirstTryPad->getName() << "]: " << TryLow
<< '\n');
- DEBUG(dbgs() << "TryHigh[" << LastTryPad->getName() << "]: " << TryHigh
+ DEBUG(dbgs() << "TryHigh[" << FirstTryPad->getName() << "]: " << TryHigh
<< '\n');
- DEBUG(dbgs() << "CatchHigh[" << LastTryPad->getName() << "]: " << CatchHigh
+ DEBUG(dbgs() << "CatchHigh[" << FirstTryPad->getName() << "]: " << CatchHigh
<< '\n');
} else if (isa<CleanupPadInst>(FirstNonPHI)) {
int CleanupState = addUnwindMapEntry(FuncInfo, ParentState, &BB);
<< BB.getName() << '\n');
for (const BasicBlock *PredBlock : predecessors(&BB))
if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
- calculateExplicitStateNumbers(FuncInfo, *PredBlock, CleanupState);
+ calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, CleanupState);
+ } else if (isa<TerminatePadInst>(FirstNonPHI)) {
+ report_fatal_error("Not yet implemented!");
+ } else {
+ llvm_unreachable("unexpected EH Pad!");
+ }
+}
+
+static int addSEHExcept(WinEHFuncInfo &FuncInfo, int ParentState,
+ const Function *Filter, const BasicBlock *Handler) {
+ SEHUnwindMapEntry Entry;
+ Entry.ToState = ParentState;
+ Entry.IsFinally = false;
+ Entry.Filter = Filter;
+ Entry.Handler = Handler;
+ FuncInfo.SEHUnwindMap.push_back(Entry);
+ return FuncInfo.SEHUnwindMap.size() - 1;
+}
+
+static int addSEHFinally(WinEHFuncInfo &FuncInfo, int ParentState,
+ const BasicBlock *Handler) {
+ SEHUnwindMapEntry Entry;
+ Entry.ToState = ParentState;
+ Entry.IsFinally = true;
+ Entry.Filter = nullptr;
+ Entry.Handler = Handler;
+ FuncInfo.SEHUnwindMap.push_back(Entry);
+ return FuncInfo.SEHUnwindMap.size() - 1;
+}
+
+static void calculateExplicitSEHStateNumbers(WinEHFuncInfo &FuncInfo,
+ const BasicBlock &BB,
+ int ParentState) {
+ assert(BB.isEHPad());
+ const Instruction *FirstNonPHI = BB.getFirstNonPHI();
+ // All catchpad instructions will be handled when we process their
+ // respective catchendpad instruction.
+ if (isa<CatchPadInst>(FirstNonPHI))
+ return;
+
+ if (isa<CatchEndPadInst>(FirstNonPHI)) {
+ // Extract the filter function and the __except basic block and create a
+ // state for them.
+ SmallVector<const CatchPadInst *, 1> Handlers;
+ findCatchPadsForCatchEndPad(&BB, Handlers);
+ assert(Handlers.size() == 1 &&
+ "SEH doesn't have multiple handlers per __try");
+ const CatchPadInst *CPI = Handlers.front();
+ const BasicBlock *CatchPadBB = CPI->getParent();
+ const Constant *FilterOrNull =
+ cast<Constant>(CPI->getArgOperand(0)->stripPointerCasts());
+ const Function *Filter = dyn_cast<Function>(FilterOrNull);
+ assert((Filter || FilterOrNull->isNullValue()) &&
+ "unexpected filter value");
+ int TryState = addSEHExcept(FuncInfo, ParentState, Filter, CatchPadBB);
+
+ // Everything in the __try block uses TryState as its parent state.
+ FuncInfo.EHPadStateMap[CPI] = TryState;
+ DEBUG(dbgs() << "Assigning state #" << TryState << " to BB "
+ << CatchPadBB->getName() << '\n');
+ for (const BasicBlock *PredBlock : predecessors(CatchPadBB))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, TryState);
+
+ // Everything in the __except block unwinds to ParentState, just like code
+ // outside the __try.
+ FuncInfo.EHPadStateMap[FirstNonPHI] = ParentState;
+ DEBUG(dbgs() << "Assigning state #" << ParentState << " to BB "
+ << BB.getName() << '\n');
+ for (const BasicBlock *PredBlock : predecessors(&BB))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, ParentState);
+ } else if (isa<CleanupPadInst>(FirstNonPHI)) {
+ int CleanupState = addSEHFinally(FuncInfo, ParentState, &BB);
+ FuncInfo.EHPadStateMap[FirstNonPHI] = CleanupState;
+ DEBUG(dbgs() << "Assigning state #" << CleanupState << " to BB "
+ << BB.getName() << '\n');
+ for (const BasicBlock *PredBlock : predecessors(&BB))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, CleanupState);
+ } else if (isa<CleanupEndPadInst>(FirstNonPHI)) {
+ // Anything unwinding through CleanupEndPadInst is in ParentState.
+ FuncInfo.EHPadStateMap[FirstNonPHI] = ParentState;
+ DEBUG(dbgs() << "Assigning state #" << ParentState << " to BB "
+ << BB.getName() << '\n');
+ for (const BasicBlock *PredBlock : predecessors(&BB))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ calculateExplicitSEHStateNumbers(FuncInfo, *PredBlock, ParentState);
} else if (isa<TerminatePadInst>(FirstNonPHI)) {
report_fatal_error("Not yet implemented!");
} else {
}
}
-void llvm::calculateWinCXXEHStateNumbers(const Function *ParentFn,
+/// Check if the EH Pad unwinds to caller. Cleanups are a little bit of a
+/// special case because we have to look at the cleanupret instruction that uses
+/// the cleanuppad.
+static bool doesEHPadUnwindToCaller(const Instruction *EHPad) {
+ auto *CPI = dyn_cast<CleanupPadInst>(EHPad);
+ if (!CPI)
+ return EHPad->mayThrow();
+
+ // This cleanup does not return or unwind, so we say it unwinds to caller.
+ if (CPI->use_empty())
+ return true;
+
+ const Instruction *User = CPI->user_back();
+ if (auto *CRI = dyn_cast<CleanupReturnInst>(User))
+ return CRI->unwindsToCaller();
+ return cast<CleanupEndPadInst>(User)->unwindsToCaller();
+}
+
+void llvm::calculateSEHStateNumbers(const Function *Fn,
+ WinEHFuncInfo &FuncInfo) {
+ // Don't compute state numbers twice.
+ if (!FuncInfo.SEHUnwindMap.empty())
+ return;
+
+ for (const BasicBlock &BB : *Fn) {
+ if (!BB.isEHPad() || !doesEHPadUnwindToCaller(BB.getFirstNonPHI()))
+ continue;
+ calculateExplicitSEHStateNumbers(FuncInfo, BB, -1);
+ }
+}
+
+void llvm::calculateWinCXXEHStateNumbers(const Function *Fn,
WinEHFuncInfo &FuncInfo) {
// Return if it's already been done.
if (!FuncInfo.EHPadStateMap.empty())
return;
- bool IsExplicit = false;
- for (const BasicBlock &BB : *ParentFn) {
+ for (const BasicBlock &BB : *Fn) {
if (!BB.isEHPad())
continue;
- // Check if the EH Pad has no exceptional successors (i.e. it unwinds to
- // caller). Cleanups are a little bit of a special case because their
- // control flow cannot be determined by looking at the pad but instead by
- // the pad's users.
- bool HasNoSuccessors = false;
+ if (BB.isLandingPad())
+ report_fatal_error("MSVC C++ EH cannot use landingpads");
const Instruction *FirstNonPHI = BB.getFirstNonPHI();
- if (FirstNonPHI->mayThrow()) {
- HasNoSuccessors = true;
- } else if (auto *CPI = dyn_cast<CleanupPadInst>(FirstNonPHI)) {
- HasNoSuccessors =
- CPI->use_empty() ||
- cast<CleanupReturnInst>(CPI->user_back())->unwindsToCaller();
- }
+ // Skip cleanupendpads; they are exits, not entries.
+ if (isa<CleanupEndPadInst>(FirstNonPHI))
+ continue;
+ if (!doesEHPadUnwindToCaller(FirstNonPHI))
+ continue;
+ calculateExplicitCXXStateNumbers(FuncInfo, BB, -1);
+ }
+}
+
+static int addClrEHHandler(WinEHFuncInfo &FuncInfo, int ParentState,
+ ClrHandlerType HandlerType, uint32_t TypeToken,
+ const BasicBlock *Handler) {
+ ClrEHUnwindMapEntry Entry;
+ Entry.Parent = ParentState;
+ Entry.Handler = Handler;
+ Entry.HandlerType = HandlerType;
+ Entry.TypeToken = TypeToken;
+ FuncInfo.ClrEHUnwindMap.push_back(Entry);
+ return FuncInfo.ClrEHUnwindMap.size() - 1;
+}
- if (!HasNoSuccessors)
+void llvm::calculateClrEHStateNumbers(const Function *Fn,
+ WinEHFuncInfo &FuncInfo) {
+ // Return if it's already been done.
+ if (!FuncInfo.EHPadStateMap.empty())
+ return;
+
+ SmallVector<std::pair<const Instruction *, int>, 8> Worklist;
+
+ // Each pad needs to be able to refer to its parent, so scan the function
+ // looking for top-level handlers and seed the worklist with them.
+ for (const BasicBlock &BB : *Fn) {
+ if (!BB.isEHPad())
continue;
- calculateExplicitStateNumbers(FuncInfo, BB, -1);
- IsExplicit = true;
+ if (BB.isLandingPad())
+ report_fatal_error("CoreCLR EH cannot use landingpads");
+ const Instruction *FirstNonPHI = BB.getFirstNonPHI();
+ if (!doesEHPadUnwindToCaller(FirstNonPHI))
+ continue;
+ // queue this with sentinel parent state -1 to mean unwind to caller.
+ Worklist.emplace_back(FirstNonPHI, -1);
}
- if (IsExplicit)
+ while (!Worklist.empty()) {
+ const Instruction *Pad;
+ int ParentState;
+ std::tie(Pad, ParentState) = Worklist.pop_back_val();
+
+ int PredState;
+ if (const CleanupEndPadInst *EndPad = dyn_cast<CleanupEndPadInst>(Pad)) {
+ FuncInfo.EHPadStateMap[EndPad] = ParentState;
+ // Queue the cleanuppad, in case it doesn't have a cleanupret.
+ Worklist.emplace_back(EndPad->getCleanupPad(), ParentState);
+ // Preds of the endpad should get the parent state.
+ PredState = ParentState;
+ } else if (const CleanupPadInst *Cleanup = dyn_cast<CleanupPadInst>(Pad)) {
+ // A cleanup can have multiple exits; don't re-process after the first.
+ if (FuncInfo.EHPadStateMap.count(Pad))
+ continue;
+ // CoreCLR personality uses arity to distinguish faults from finallies.
+ const BasicBlock *PadBlock = Cleanup->getParent();
+ ClrHandlerType HandlerType =
+ (Cleanup->getNumOperands() ? ClrHandlerType::Fault
+ : ClrHandlerType::Finally);
+ int NewState =
+ addClrEHHandler(FuncInfo, ParentState, HandlerType, 0, PadBlock);
+ FuncInfo.EHPadStateMap[Cleanup] = NewState;
+ // Propagate the new state to all preds of the cleanup
+ PredState = NewState;
+ } else if (const CatchEndPadInst *EndPad = dyn_cast<CatchEndPadInst>(Pad)) {
+ FuncInfo.EHPadStateMap[EndPad] = ParentState;
+ // Preds of the endpad should get the parent state.
+ PredState = ParentState;
+ } else if (const CatchPadInst *Catch = dyn_cast<CatchPadInst>(Pad)) {
+ const BasicBlock *Handler = Catch->getNormalDest();
+ uint32_t TypeToken = static_cast<uint32_t>(
+ cast<ConstantInt>(Catch->getArgOperand(0))->getZExtValue());
+ int NewState = addClrEHHandler(FuncInfo, ParentState,
+ ClrHandlerType::Catch, TypeToken, Handler);
+ FuncInfo.EHPadStateMap[Catch] = NewState;
+ // Preds of the catch get its state
+ PredState = NewState;
+ } else {
+ llvm_unreachable("Unexpected EH pad");
+ }
+
+ // Queue all predecessors with the given state
+ for (const BasicBlock *Pred : predecessors(Pad->getParent())) {
+ if ((Pred = getEHPadFromPredecessor(Pred)))
+ Worklist.emplace_back(Pred->getFirstNonPHI(), PredState);
+ }
+ }
+}
+
+void WinEHPrepare::replaceTerminatePadWithCleanup(Function &F) {
+ if (Personality != EHPersonality::MSVC_CXX)
return;
+ for (BasicBlock &BB : F) {
+ Instruction *First = BB.getFirstNonPHI();
+ auto *TPI = dyn_cast<TerminatePadInst>(First);
+ if (!TPI)
+ continue;
+
+ if (TPI->getNumArgOperands() != 1)
+ report_fatal_error(
+ "Expected a unary terminatepad for MSVC C++ personalities!");
+
+ auto *TerminateFn = dyn_cast<Function>(TPI->getArgOperand(0));
+ if (!TerminateFn)
+ report_fatal_error("Function operand expected in terminatepad for MSVC "
+ "C++ personalities!");
+
+ // Insert the cleanuppad instruction.
+ auto *CPI = CleanupPadInst::Create(
+ BB.getContext(), {}, Twine("terminatepad.for.", BB.getName()), &BB);
+
+ // Insert the call to the terminate instruction.
+ auto *CallTerminate = CallInst::Create(TerminateFn, {}, &BB);
+ CallTerminate->setDoesNotThrow();
+ CallTerminate->setDoesNotReturn();
+ CallTerminate->setCallingConv(TerminateFn->getCallingConv());
+
+ // Insert a new terminator for the cleanuppad using the same successor as
+ // the terminatepad.
+ CleanupReturnInst::Create(CPI, TPI->getUnwindDest(), &BB);
- 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());
+ // Let's remove the terminatepad now that we've inserted the new
+ // instructions.
+ TPI->eraseFromParent();
+ }
}
-void WinEHPrepare::colorFunclets(Function &F,
- SmallVectorImpl<BasicBlock *> &EntryBlocks) {
+static void
+colorFunclets(Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks,
+ std::map<BasicBlock *, std::set<BasicBlock *>> &BlockColors,
+ std::map<BasicBlock *, std::set<BasicBlock *>> &FuncletBlocks,
+ std::map<BasicBlock *, std::set<BasicBlock *>> &FuncletChildren) {
SmallVector<std::pair<BasicBlock *, BasicBlock *>, 16> Worklist;
BasicBlock *EntryBlock = &F.getEntryBlock();
BasicBlock *Color;
std::tie(Visiting, Color) = Worklist.pop_back_val();
Instruction *VisitingHead = Visiting->getFirstNonPHI();
- if (VisitingHead->isEHPad() && !isa<CatchEndPadInst>(VisitingHead)) {
+ if (VisitingHead->isEHPad() && !isa<CatchEndPadInst>(VisitingHead) &&
+ !isa<CleanupEndPadInst>(VisitingHead)) {
// Mark this as a funclet head as a member of itself.
FuncletBlocks[Visiting].insert(Visiting);
// Queue exits with the parent color.
- for (User *Exit : VisitingHead->users()) {
- for (BasicBlock *Succ :
- successors(cast<Instruction>(Exit)->getParent())) {
- if (BlockColors[Succ].insert(Color).second) {
- Worklist.push_back({Succ, Color});
- }
+ for (User *U : VisitingHead->users()) {
+ if (auto *Exit = dyn_cast<TerminatorInst>(U)) {
+ for (BasicBlock *Succ : successors(Exit->getParent()))
+ if (BlockColors[Succ].insert(Color).second)
+ Worklist.push_back({Succ, Color});
}
}
// Handle CatchPad specially since its successors need different colors.
} else {
// Note that this is a member of the given color.
FuncletBlocks[Color].insert(Visiting);
- TerminatorInst *Terminator = Visiting->getTerminator();
- if (isa<CleanupReturnInst>(Terminator) ||
- isa<CatchReturnInst>(Terminator)) {
- // These block's successors have already been queued with the parent
- // color.
- continue;
- }
+ }
+
+ TerminatorInst *Terminator = Visiting->getTerminator();
+ if (isa<CleanupReturnInst>(Terminator) ||
+ isa<CatchReturnInst>(Terminator) ||
+ isa<CleanupEndPadInst>(Terminator)) {
+ // These blocks' successors have already been queued with the parent
+ // color.
+ continue;
}
for (BasicBlock *Succ : successors(Visiting)) {
if (isa<CatchEndPadInst>(Succ->getFirstNonPHI())) {
}
}
-bool WinEHPrepare::prepareExplicitEH(
- Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks) {
- // Remove unreachable blocks. It is not valuable to assign them a color and
- // their existence can trick us into thinking values are alive when they are
- // not.
- removeUnreachableBlocks(F);
+void WinEHPrepare::colorFunclets(Function &F,
+ SmallVectorImpl<BasicBlock *> &EntryBlocks) {
+ ::colorFunclets(F, EntryBlocks, BlockColors, FuncletBlocks, FuncletChildren);
+}
- // Determine which blocks are reachable from which funclet entries.
- colorFunclets(F, EntryBlocks);
+void llvm::calculateCatchReturnSuccessorColors(const Function *Fn,
+ WinEHFuncInfo &FuncInfo) {
+ SmallVector<LandingPadInst *, 4> LPads;
+ SmallVector<ResumeInst *, 4> Resumes;
+ SmallVector<BasicBlock *, 4> EntryBlocks;
+ // colorFunclets needs the set of EntryBlocks, get them using
+ // findExceptionalConstructs.
+ bool ForExplicitEH = findExceptionalConstructs(const_cast<Function &>(*Fn),
+ LPads, Resumes, EntryBlocks);
+ if (!ForExplicitEH)
+ return;
+
+ std::map<BasicBlock *, std::set<BasicBlock *>> BlockColors;
+ std::map<BasicBlock *, std::set<BasicBlock *>> FuncletBlocks;
+ std::map<BasicBlock *, std::set<BasicBlock *>> FuncletChildren;
+ // Figure out which basic blocks belong to which funclets.
+ colorFunclets(const_cast<Function &>(*Fn), EntryBlocks, BlockColors,
+ FuncletBlocks, FuncletChildren);
+ // We need to find the catchret successors. To do this, we must first find
+ // all the catchpad funclets.
+ for (auto &Funclet : FuncletBlocks) {
+ // Figure out what kind of funclet we are looking at; We only care about
+ // catchpads.
+ BasicBlock *FuncletPadBB = Funclet.first;
+ Instruction *FirstNonPHI = FuncletPadBB->getFirstNonPHI();
+ auto *CatchPad = dyn_cast<CatchPadInst>(FirstNonPHI);
+ if (!CatchPad)
+ continue;
+
+ // The users of a catchpad are always catchrets.
+ for (User *Exit : CatchPad->users()) {
+ auto *CatchReturn = dyn_cast<CatchReturnInst>(Exit);
+ if (!CatchReturn)
+ continue;
+ BasicBlock *CatchRetSuccessor = CatchReturn->getSuccessor();
+ std::set<BasicBlock *> &SuccessorColors = BlockColors[CatchRetSuccessor];
+ assert(SuccessorColors.size() == 1 && "Expected BB to be monochrome!");
+ BasicBlock *Color = *SuccessorColors.begin();
+ if (auto *CPI = dyn_cast<CatchPadInst>(Color->getFirstNonPHI()))
+ Color = CPI->getNormalDest();
+ // Record the catchret successor's funclet membership.
+ FuncInfo.CatchRetSuccessorColorMap[CatchReturn] = Color;
+ }
+ }
+}
+
+void WinEHPrepare::demotePHIsOnFunclets(Function &F) {
// Strip PHI nodes off of EH pads.
SmallVector<PHINode *, 16> PHINodes;
for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE;) {
PN->replaceAllUsesWith(UndefValue::get(PN->getType()));
PN->eraseFromParent();
}
+}
+void WinEHPrepare::demoteUsesBetweenFunclets(Function &F) {
// Turn all inter-funclet uses of a Value into loads and stores.
for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE;) {
BasicBlock *BB = FI++;
demoteNonlocalUses(I, ColorsForBB, F);
}
}
+}
+
+void WinEHPrepare::demoteArgumentUses(Function &F) {
// Also demote function parameters used in funclets.
std::set<BasicBlock *> &ColorsForEntry = BlockColors[&F.getEntryBlock()];
for (Argument &Arg : F.args())
demoteNonlocalUses(&Arg, ColorsForEntry, F);
+}
+void WinEHPrepare::cloneCommonBlocks(
+ Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks) {
// We need to clone all blocks which belong to multiple funclets. Values are
// remapped throughout the funclet to propogate both the new instructions
// *and* the new basic blocks themselves.
// Loop over all instructions, fixing each one as we find it...
for (Instruction &I : *BB)
RemapInstruction(&I, VMap, RF_IgnoreMissingEntries);
+
+ // Check to see if SuccBB has PHI nodes. If so, we need to add entries to
+ // the PHI nodes for NewBB now.
+ for (auto &BBMapping : Orig2Clone) {
+ BasicBlock *OldBlock = BBMapping.first;
+ BasicBlock *NewBlock = BBMapping.second;
+ for (BasicBlock *SuccBB : successors(NewBlock)) {
+ for (Instruction &SuccI : *SuccBB) {
+ auto *SuccPN = dyn_cast<PHINode>(&SuccI);
+ if (!SuccPN)
+ break;
+
+ // Ok, we have a PHI node. Figure out what the incoming value was for
+ // the OldBlock.
+ int OldBlockIdx = SuccPN->getBasicBlockIndex(OldBlock);
+ if (OldBlockIdx == -1)
+ break;
+ Value *IV = SuccPN->getIncomingValue(OldBlockIdx);
+
+ // Remap the value if necessary.
+ if (auto *Inst = dyn_cast<Instruction>(IV)) {
+ ValueToValueMapTy::iterator I = VMap.find(Inst);
+ if (I != VMap.end())
+ IV = I->second;
+ }
+
+ SuccPN->addIncoming(IV, NewBlock);
+ }
+ }
+ }
+
+ for (ValueToValueMapTy::value_type VT : VMap) {
+ // If there were values defined in BB that are used outside the funclet,
+ // then we now have to update all uses of the value to use either the
+ // original value, the cloned value, or some PHI derived value. This can
+ // require arbitrary PHI insertion, of which we are prepared to do, clean
+ // these up now.
+ SmallVector<Use *, 16> UsesToRename;
+
+ auto *OldI = dyn_cast<Instruction>(const_cast<Value *>(VT.first));
+ if (!OldI)
+ continue;
+ auto *NewI = cast<Instruction>(VT.second);
+ // Scan all uses of this instruction to see if it is used outside of its
+ // funclet, and if so, record them in UsesToRename.
+ for (Use &U : OldI->uses()) {
+ Instruction *UserI = cast<Instruction>(U.getUser());
+ BasicBlock *UserBB = UserI->getParent();
+ std::set<BasicBlock *> &ColorsForUserBB = BlockColors[UserBB];
+ assert(!ColorsForUserBB.empty());
+ if (ColorsForUserBB.size() > 1 ||
+ *ColorsForUserBB.begin() != FuncletPadBB)
+ UsesToRename.push_back(&U);
+ }
+
+ // If there are no uses outside the block, we're done with this
+ // instruction.
+ if (UsesToRename.empty())
+ continue;
+
+ // We found a use of OldI outside of the funclet. Rename all uses of OldI
+ // that are outside its funclet to be uses of the appropriate PHI node
+ // etc.
+ SSAUpdater SSAUpdate;
+ SSAUpdate.Initialize(OldI->getType(), OldI->getName());
+ SSAUpdate.AddAvailableValue(OldI->getParent(), OldI);
+ SSAUpdate.AddAvailableValue(NewI->getParent(), NewI);
+
+ while (!UsesToRename.empty())
+ SSAUpdate.RewriteUseAfterInsertions(*UsesToRename.pop_back_val());
+ }
}
+}
+void WinEHPrepare::removeImplausibleTerminators(Function &F) {
// Remove implausible terminators and replace them with UnreachableInst.
for (auto &Funclet : FuncletBlocks) {
BasicBlock *FuncletPadBB = Funclet.first;
bool IsUnreachableCatchret = false;
if (auto *CRI = dyn_cast<CatchReturnInst>(TI))
IsUnreachableCatchret = CRI->getCatchPad() != CatchPad;
- // The token consumed by a CleanupPadInst must match the funclet token.
+ // The token consumed by a CleanupReturnInst must match the funclet token.
bool IsUnreachableCleanupret = false;
if (auto *CRI = dyn_cast<CleanupReturnInst>(TI))
IsUnreachableCleanupret = CRI->getCleanupPad() != CleanupPad;
- if (IsUnreachableRet || IsUnreachableCatchret || IsUnreachableCleanupret) {
+ // The token consumed by a CleanupEndPadInst must match the funclet token.
+ bool IsUnreachableCleanupendpad = false;
+ if (auto *CEPI = dyn_cast<CleanupEndPadInst>(TI))
+ IsUnreachableCleanupendpad = CEPI->getCleanupPad() != CleanupPad;
+ if (IsUnreachableRet || IsUnreachableCatchret ||
+ IsUnreachableCleanupret || IsUnreachableCleanupendpad) {
+ // Loop through all of our successors and make sure they know that one
+ // of their predecessors is going away.
+ for (BasicBlock *SuccBB : TI->successors())
+ SuccBB->removePredecessor(BB);
+
+ if (IsUnreachableCleanupendpad) {
+ // We can't simply replace a cleanupendpad with unreachable, because
+ // its predecessor edges are EH edges and unreachable is not an EH
+ // pad. Change all predecessors to the "unwind to caller" form.
+ for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB);
+ PI != PE;) {
+ BasicBlock *Pred = *PI++;
+ removeUnwindEdge(Pred);
+ }
+ }
+
new UnreachableInst(BB->getContext(), TI);
TI->eraseFromParent();
}
+ // FIXME: Check for invokes/cleanuprets/cleanupendpads which unwind to
+ // implausible catchendpads (i.e. catchendpad not in immediate parent
+ // funclet).
}
}
+}
+void WinEHPrepare::cleanupPreparedFunclets(Function &F) {
// Clean-up some of the mess we made by removing useles PHI nodes, trivial
// branches, etc.
for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE;) {
// We might have some unreachable blocks after cleaning up some impossible
// control flow.
removeUnreachableBlocks(F);
+}
+void WinEHPrepare::verifyPreparedFunclets(Function &F) {
// Recolor the CFG to verify that all is well.
for (BasicBlock &BB : F) {
size_t NumColors = BlockColors[&BB].size();
report_fatal_error("Uncolored BB!");
if (NumColors > 1)
report_fatal_error("Multicolor BB!");
- bool EHPadHasPHI = BB.isEHPad() && isa<PHINode>(BB.begin());
- assert(!EHPadHasPHI && "EH Pad still has a PHI!");
- if (EHPadHasPHI)
- report_fatal_error("EH Pad still has a PHI!");
+ if (!DisableDemotion) {
+ bool EHPadHasPHI = BB.isEHPad() && isa<PHINode>(BB.begin());
+ assert(!EHPadHasPHI && "EH Pad still has a PHI!");
+ if (EHPadHasPHI)
+ report_fatal_error("EH Pad still has a PHI!");
+ }
}
+}
+
+bool WinEHPrepare::prepareExplicitEH(
+ Function &F, SmallVectorImpl<BasicBlock *> &EntryBlocks) {
+ // Remove unreachable blocks. It is not valuable to assign them a color and
+ // their existence can trick us into thinking values are alive when they are
+ // not.
+ removeUnreachableBlocks(F);
+
+ replaceTerminatePadWithCleanup(F);
+
+ // Determine which blocks are reachable from which funclet entries.
+ colorFunclets(F, EntryBlocks);
+
+ if (!DisableDemotion) {
+ demotePHIsOnFunclets(F);
+
+ demoteUsesBetweenFunclets(F);
+
+ demoteArgumentUses(F);
+ }
+
+ cloneCommonBlocks(F, EntryBlocks);
+
+ if (!DisableCleanups) {
+ removeImplausibleTerminators(F);
+
+ cleanupPreparedFunclets(F);
+ }
+
+ verifyPreparedFunclets(F);
BlockColors.clear();
FuncletBlocks.clear();
U.set(Load);
}
}
+
+void WinEHFuncInfo::addIPToStateRange(const BasicBlock *PadBB,
+ MCSymbol *InvokeBegin,
+ MCSymbol *InvokeEnd) {
+ assert(PadBB->isEHPad() && EHPadStateMap.count(PadBB->getFirstNonPHI()) &&
+ "should get EH pad BB with precomputed state");
+ InvokeToStateMap[InvokeBegin] =
+ std::make_pair(EHPadStateMap[PadBB->getFirstNonPHI()], InvokeEnd);
+}
projects / oota-llvm.git / blobdiff