//===----------------------------------------------------------------------===//
//
// This pass lowers LLVM IR exception handling into something closer to what the
-// backend wants. It snifs the personality function to see which kind of
-// preparation is necessary. If the personality function uses the Itanium LSDA,
-// this pass delegates to the DWARF EH preparation pass.
+// backend wants for functions using a personality function from a runtime
+// provided by MSVC. Functions with other personality functions are left alone
+// and may be prepared by other passes. In particular, all supported MSVC
+// personality functions require cleanup code to be outlined, and the C++
+// personality requires catch handler code to be outlined.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SetVector.h"
+#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"
#include "llvm/IR/Module.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/Pass.h"
-#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
public:
static char ID; // Pass identification, replacement for typeid.
WinEHPrepare(const TargetMachine *TM = nullptr)
- : FunctionPass(ID), DT(nullptr) {}
+ : FunctionPass(ID) {
+ if (TM)
+ TheTriple = Triple(TM->getTargetTriple());
+ }
bool runOnFunction(Function &Fn) override;
private:
bool prepareExceptionHandlers(Function &F,
SmallVectorImpl<LandingPadInst *> &LPads);
+ void identifyEHBlocks(Function &F, SmallVectorImpl<LandingPadInst *> &LPads);
void promoteLandingPadValues(LandingPadInst *LPad);
void demoteValuesLiveAcrossHandlers(Function &F,
SmallVectorImpl<LandingPadInst *> &LPads);
+ void findSEHEHReturnPoints(Function &F,
+ SetVector<BasicBlock *> &EHReturnBlocks);
+ void findCXXEHReturnPoints(Function &F,
+ SetVector<BasicBlock *> &EHReturnBlocks);
+ void getPossibleReturnTargets(Function *ParentF, Function *HandlerF,
+ SetVector<BasicBlock*> &Targets);
void completeNestedLandingPad(Function *ParentFn,
LandingPadInst *OutlinedLPad,
const LandingPadInst *OriginalLPad,
FrameVarInfoMap &VarInfo);
+ Function *createHandlerFunc(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,
void processSEHCatchHandler(CatchHandler *Handler, BasicBlock *StartBB);
+ Triple TheTriple;
+
// All fields are reset by runOnFunction.
- DominatorTree *DT;
- EHPersonality Personality;
+ DominatorTree *DT = nullptr;
+ const TargetLibraryInfo *LibInfo = nullptr;
+ EHPersonality Personality = EHPersonality::Unknown;
CatchHandlerMapTy CatchHandlerMap;
CleanupHandlerMapTy CleanupHandlerMap;
DenseMap<const LandingPadInst *, LandingPadMap> LPadMaps;
+ SmallPtrSet<BasicBlock *, 4> NormalBlocks;
+ SmallPtrSet<BasicBlock *, 4> EHBlocks;
+ SetVector<BasicBlock *> EHReturnBlocks;
// This maps landing pad instructions found in outlined handlers to
// the landing pad instruction in the parent function from which they
// outlined into a handler. This is done after all handlers have been
// outlined but before the outlined code is pruned from the parent function.
DenseMap<const BasicBlock *, BasicBlock *> LPadTargetBlocks;
+
+ // Map from outlined handler to call to llvm.frameaddress(1). Only used for
+ // 32-bit EH.
+ DenseMap<Function *, Value *> HandlerToParentFP;
+
+ AllocaInst *SEHExceptionCodeSlot = nullptr;
};
class WinEHFrameVariableMaterializer : public ValueMaterializer {
public:
- WinEHFrameVariableMaterializer(Function *OutlinedFn,
+ WinEHFrameVariableMaterializer(Function *OutlinedFn, Value *ParentFP,
FrameVarInfoMap &FrameVarInfo);
~WinEHFrameVariableMaterializer() override {}
class WinEHCloningDirectorBase : public CloningDirector {
public:
- WinEHCloningDirectorBase(Function *HandlerFn, FrameVarInfoMap &VarInfo,
- LandingPadMap &LPadMap)
- : Materializer(HandlerFn, VarInfo),
+ WinEHCloningDirectorBase(Function *HandlerFn, Value *ParentFP,
+ FrameVarInfoMap &VarInfo, LandingPadMap &LPadMap)
+ : Materializer(HandlerFn, ParentFP, VarInfo),
SelectorIDType(Type::getInt32Ty(HandlerFn->getContext())),
Int8PtrType(Type::getInt8PtrTy(HandlerFn->getContext())),
- LPadMap(LPadMap) {
- auto AI = HandlerFn->getArgumentList().begin();
- ++AI;
- EstablisherFrame = AI;
- }
+ LPadMap(LPadMap), ParentFP(ParentFP) {}
CloningAction handleInstruction(ValueToValueMapTy &VMap,
const Instruction *Inst,
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;
LandingPadMap &LPadMap;
/// The value representing the parent frame pointer.
- Value *EstablisherFrame;
+ Value *ParentFP;
};
class WinEHCatchDirector : public WinEHCloningDirectorBase {
public:
WinEHCatchDirector(
- Function *CatchFn, Value *Selector, FrameVarInfoMap &VarInfo,
- LandingPadMap &LPadMap,
- DenseMap<LandingPadInst *, const LandingPadInst *> &NestedLPads)
- : WinEHCloningDirectorBase(CatchFn, VarInfo, LPadMap),
+ Function *CatchFn, Value *ParentFP, Value *Selector,
+ FrameVarInfoMap &VarInfo, LandingPadMap &LPadMap,
+ DenseMap<LandingPadInst *, const LandingPadInst *> &NestedLPads,
+ DominatorTree *DT, SmallPtrSetImpl<BasicBlock *> &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,
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,
BasicBlock *NewBB) override;
- CloningAction handleCompare(ValueToValueMapTy &VMap,
- const CmpInst *Compare, BasicBlock *NewBB) override;
+ CloningAction handleCompare(ValueToValueMapTy &VMap, const CmpInst *Compare,
+ BasicBlock *NewBB) override;
CloningAction handleLandingPad(ValueToValueMapTy &VMap,
const LandingPadInst *LPad,
BasicBlock *NewBB) override;
// This will be a reference to the field of the same name in the WinEHPrepare
// object which instantiates this WinEHCatchDirector object.
DenseMap<LandingPadInst *, const LandingPadInst *> &NestedLPtoOriginalLP;
+ DominatorTree *DT;
+ SmallPtrSetImpl<BasicBlock *> &EHBlocks;
};
class WinEHCleanupDirector : public WinEHCloningDirectorBase {
public:
- WinEHCleanupDirector(Function *CleanupFn, FrameVarInfoMap &VarInfo,
- LandingPadMap &LPadMap)
- : WinEHCloningDirectorBase(CleanupFn, VarInfo, LPadMap) {}
+ WinEHCleanupDirector(Function *CleanupFn, Value *ParentFP,
+ FrameVarInfoMap &VarInfo, LandingPadMap &LPadMap)
+ : WinEHCloningDirectorBase(CleanupFn, ParentFP, VarInfo,
+ LPadMap) {}
CloningAction handleBeginCatch(ValueToValueMapTy &VMap,
const Instruction *Inst,
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,
BasicBlock *NewBB) override;
- CloningAction handleCompare(ValueToValueMapTy &VMap,
- const CmpInst *Compare, BasicBlock *NewBB) override;
+ CloningAction handleCompare(ValueToValueMapTy &VMap, const CmpInst *Compare,
+ BasicBlock *NewBB) override;
CloningAction handleLandingPad(ValueToValueMapTy &VMap,
const LandingPadInst *LPad,
BasicBlock *NewBB) override;
return new WinEHPrepare(TM);
}
-// FIXME: Remove this once the backend can handle the prepared IR.
-static cl::opt<bool>
- SEHPrepare("sehprepare", cl::Hidden,
- cl::desc("Prepare functions with SEH personalities"));
-
bool WinEHPrepare::runOnFunction(Function &Fn) {
// No need to prepare outlined handlers.
if (Fn.hasFnAttribute("wineh-parent"))
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<DominatorTreeWrapperPass>().getDomTree();
-
- if (isAsynchronousEHPersonality(Personality) && !SEHPrepare) {
- // Replace all resume instructions with unreachable.
- // FIXME: Remove this once the backend can handle the prepared IR.
- for (ResumeInst *Resume : Resumes) {
- IRBuilder<>(Resume).CreateUnreachable();
- Resume->eraseFromParent();
- }
- return true;
- }
+ LibInfo = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
// If there were any landing pads, prepareExceptionHandlers will make changes.
prepareExceptionHandlers(Fn, LPads);
void WinEHPrepare::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<DominatorTreeWrapperPass>();
+ AU.addRequired<TargetLibraryInfoWrapperPass>();
}
static bool isSelectorDispatch(BasicBlock *BB, BasicBlock *&CatchHandler,
}
}
+// Attempt to find an instruction where a block can be split before
+// a call to llvm.eh.begincatch and its operands. If the block
+// begins with the begincatch call or one of its adjacent operands
+// the block will not be split.
+static Instruction *findBeginCatchSplitPoint(BasicBlock *BB,
+ IntrinsicInst *II) {
+ // If the begincatch call is already the first instruction in the block,
+ // don't split.
+ Instruction *FirstNonPHI = BB->getFirstNonPHI();
+ if (II == FirstNonPHI)
+ return nullptr;
+
+ // If either operand is in the same basic block as the instruction and
+ // isn't used by another instruction before the begincatch call, include it
+ // in the split block.
+ auto *Op0 = dyn_cast<Instruction>(II->getOperand(0));
+ auto *Op1 = dyn_cast<Instruction>(II->getOperand(1));
+
+ Instruction *I = II->getPrevNode();
+ Instruction *LastI = II;
+
+ while (I == Op0 || I == Op1) {
+ // If the block begins with one of the operands and there are no other
+ // instructions between the operand and the begincatch call, don't split.
+ if (I == FirstNonPHI)
+ return nullptr;
+
+ LastI = I;
+ I = I->getPrevNode();
+ }
+
+ // If there is at least one instruction in the block before the begincatch
+ // call and its operands, split the block at either the begincatch or
+ // its operand.
+ return LastI;
+}
+
/// Find all points where exceptional control rejoins normal control flow via
/// llvm.eh.endcatch. Add them to the normal bb reachability worklist.
-static void findCXXEHReturnPoints(Function &F,
- SetVector<BasicBlock *> &EHReturnBlocks) {
+void WinEHPrepare::findCXXEHReturnPoints(
+ Function &F, SetVector<BasicBlock *> &EHReturnBlocks) {
for (auto BBI = F.begin(), BBE = F.end(); BBI != BBE; ++BBI) {
BasicBlock *BB = BBI;
for (Instruction &I : *BB) {
+ if (match(&I, m_Intrinsic<Intrinsic::eh_begincatch>())) {
+ Instruction *SplitPt =
+ findBeginCatchSplitPoint(BB, cast<IntrinsicInst>(&I));
+ if (SplitPt) {
+ // Split the block before the llvm.eh.begincatch call to allow
+ // cleanup and catch code to be distinguished later.
+ // Do not update BBI because we still need to process the
+ // portion of the block that we are splitting off.
+ SplitBlock(BB, SplitPt, DT);
+ break;
+ }
+ }
if (match(&I, m_Intrinsic<Intrinsic::eh_endcatch>())) {
// Split the block after the call to llvm.eh.endcatch if there is
// anything other than an unconditional branch, or if the successor
isa<PHINode>(Br->getSuccessor(0)->begin())) {
DEBUG(dbgs() << "splitting block " << BB->getName()
<< " with llvm.eh.endcatch\n");
- BBI = BB->splitBasicBlock(I.getNextNode(), "ehreturn");
+ BBI = SplitBlock(BB, I.getNextNode(), DT);
}
// The next BB is normal control flow.
EHReturnBlocks.insert(BB->getTerminator()->getSuccessor(0));
/// Find all points where exceptions control rejoins normal control flow via
/// selector dispatch.
-static void findSEHEHReturnPoints(Function &F,
- SetVector<BasicBlock *> &EHReturnBlocks) {
+void WinEHPrepare::findSEHEHReturnPoints(
+ Function &F, SetVector<BasicBlock *> &EHReturnBlocks) {
for (auto BBI = F.begin(), BBE = F.end(); BBI != BBE; ++BBI) {
BasicBlock *BB = BBI;
// If the landingpad is a catch-all, treat the whole lpad as if it is
}
}
-/// 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<LandingPadInst *> &LPads) {
+void WinEHPrepare::identifyEHBlocks(Function &F,
+ SmallVectorImpl<LandingPadInst *> &LPads) {
DEBUG(dbgs() << "Demoting values live across exception handlers in function "
<< F.getName() << '\n');
// - 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<BasicBlock *, 4> NormalBlocks;
- SmallPtrSet<BasicBlock *, 4> EHBlocks;
- SetVector<BasicBlock *> EHReturnBlocks;
- SetVector<BasicBlock *> Worklist;
if (Personality == EHPersonality::MSVC_CXX)
findCXXEHReturnPoints(F, EHReturnBlocks);
dbgs() << " " << BB->getName() << '\n';
});
- // Join points should not have phis at this point, unless they are a
- // landingpad, in which case we will demote their phis later.
+// Join points should not have phis at this point, unless they are a
+// landingpad, in which case we will demote their phis later.
#ifndef NDEBUG
for (BasicBlock *BB : EHReturnBlocks)
assert((BB->isLandingPad() || !isa<PHINode>(BB->begin())) &&
// Normal blocks are the blocks reachable from the entry block and all EH
// return points.
+ SetVector<BasicBlock *> Worklist;
Worklist = EHReturnBlocks;
Worklist.insert(&F.getEntryBlock());
findReachableBlocks(NormalBlocks, Worklist, nullptr);
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<LandingPadInst *> &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());
+
SetVector<Argument *> ArgsToDemote;
SetVector<Instruction *> InstrsToDemote;
for (BasicBlock &BB : F) {
return false;
}
+ identifyEHBlocks(F, LPads);
demoteValuesLiveAcrossHandlers(F, LPads);
// These containers are used to re-map frame variables that are used in
Type *Int32Type = Type::getInt32Ty(Context);
Function *ActionIntrin = Intrinsic::getDeclaration(M, Intrinsic::eh_actions);
+ if (isAsynchronousEHPersonality(Personality)) {
+ // FIXME: Switch the ehptr type to i32 and then switch this.
+ SEHExceptionCodeSlot =
+ new AllocaInst(Int8PtrType, nullptr, "seh_exception_code",
+ 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<std::pair<CallInst*, IndirectBrInst *>, 4> LPadImpls;
+
for (LandingPadInst *LPad : LPads) {
// Look for evidence that this landingpad has already been processed.
bool LPadHasActionList = false;
outlineHandler(Action, &F, LPad, StartBB, FrameVarInfo);
}
- // Replace the landing pad with a new llvm.eh.action based landing pad.
- BasicBlock *NewLPadBB = BasicBlock::Create(Context, "lpad", &F, LPadBB);
- assert(!isa<PHINode>(LPadBB->begin()));
- auto *NewLPad = cast<LandingPadInst>(LPad->clone());
- NewLPadBB->getInstList().push_back(NewLPad);
- while (!pred_empty(LPadBB)) {
- auto *pred = *pred_begin(LPadBB);
- InvokeInst *Invoke = cast<InvokeInst>(pred->getTerminator());
- Invoke->setUnwindDest(NewLPadBB);
- }
+ // Split the block after the landingpad instruction so that it is just a
+ // call to llvm.eh.actions followed by indirectbr.
+ assert(!isa<PHINode>(LPadBB->begin()) && "lpad phi not removed");
+ SplitBlock(LPadBB, LPad->getNextNode(), DT);
+ // Erase the branch inserted by the split so we can insert indirectbr.
+ LPadBB->getTerminator()->eraseFromParent();
- // If anyone is still using the old landingpad value, just give them undef
- // instead. The eh pointer and selector values are not real.
+ // Replace all extracted values with undef and ultimately replace the
+ // landingpad with undef.
+ SmallVector<Instruction *, 4> SEHCodeUses;
+ SmallVector<Instruction *, 4> EHUndefs;
+ for (User *U : LPad->users()) {
+ auto *E = dyn_cast<ExtractValueInst>(U);
+ if (!E)
+ continue;
+ assert(E->getNumIndices() == 1 &&
+ "Unexpected operation: extracting both landing pad values");
+ unsigned Idx = *E->idx_begin();
+ assert((Idx == 0 || Idx == 1) && "unexpected index");
+ if (Idx == 0 && isAsynchronousEHPersonality(Personality))
+ SEHCodeUses.push_back(E);
+ else
+ EHUndefs.push_back(E);
+ }
+ for (Instruction *E : EHUndefs) {
+ E->replaceAllUsesWith(UndefValue::get(E->getType()));
+ E->eraseFromParent();
+ }
LPad->replaceAllUsesWith(UndefValue::get(LPad->getType()));
- // Replace the mapping of any nested landing pad that previously mapped
- // to this landing pad with a referenced to the cloned version.
- for (auto &LPadPair : NestedLPtoOriginalLP) {
- const LandingPadInst *OriginalLPad = LPadPair.second;
- if (OriginalLPad == LPad) {
- LPadPair.second = NewLPad;
+ // Rewrite uses of the exception pointer to loads of an alloca.
+ for (Instruction *E : SEHCodeUses) {
+ SmallVector<Use *, 4> Uses;
+ for (Use &U : E->uses())
+ Uses.push_back(&U);
+ for (Use *U : Uses) {
+ auto *I = cast<Instruction>(U->getUser());
+ if (isa<ResumeInst>(I))
+ continue;
+ LoadInst *LI;
+ if (auto *Phi = dyn_cast<PHINode>(I))
+ LI = new LoadInst(SEHExceptionCodeSlot, "sehcode", false,
+ Phi->getIncomingBlock(*U));
+ else
+ LI = new LoadInst(SEHExceptionCodeSlot, "sehcode", false, I);
+ U->set(LI);
}
+ E->replaceAllUsesWith(UndefValue::get(E->getType()));
+ E->eraseFromParent();
}
- // Replace uses of the old lpad in phis with this block and delete the old
- // block.
- LPadBB->replaceSuccessorsPhiUsesWith(NewLPadBB);
- LPadBB->getTerminator()->eraseFromParent();
- new UnreachableInst(LPadBB->getContext(), LPadBB);
-
// Add a call to describe the actions for this landing pad.
std::vector<Value *> ActionArgs;
for (ActionHandler *Action : Actions) {
ActionArgs.push_back(Action->getHandlerBlockOrFunc());
}
CallInst *Recover =
- CallInst::Create(ActionIntrin, ActionArgs, "recover", NewLPadBB);
+ CallInst::Create(ActionIntrin, ActionArgs, "recover", LPadBB);
- // Add an indirect branch listing possible successors of the catch handlers.
SetVector<BasicBlock *> ReturnTargets;
for (ActionHandler *Action : Actions) {
if (auto *CatchAction = dyn_cast<CatchHandler>(Action)) {
}
}
IndirectBrInst *Branch =
- IndirectBrInst::Create(Recover, ReturnTargets.size(), NewLPadBB);
+ 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.
completeNestedLandingPad(&F, LPadPair.first, LPadPair.second, FrameVarInfo);
NestedLPtoOriginalLP.clear();
+ // Update the indirectbr instructions' target lists if necessary.
+ SetVector<BasicBlock*> CheckedTargets;
+ SmallVector<std::unique_ptr<ActionHandler>, 4> ActionList;
+ for (auto &LPadImplPair : LPadImpls) {
+ IntrinsicInst *Recover = cast<IntrinsicInst>(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<BasicBlock *> ReturnTargets;
+ for (const auto &Action : ActionList) {
+ if (auto *CA = dyn_cast<CatchHandler>(Action.get())) {
+ Function *Handler = cast<Function>(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<BranchInst>(Target->getTerminator());
+ if (Br && Br->isUnconditional() &&
+ Br != Target->getFirstNonPHIOrDbgOrLifetime()) {
+ Instruction *Prev = Br->getPrevNode();
+ if (match(cast<Value>(Prev), m_Intrinsic<Intrinsic::eh_endcatch>()))
+ Prev->eraseFromParent();
+ }
+ }
+ }
+ }
+ LPadImpls.clear();
+
F.addFnAttr("wineh-parent", F.getName());
// Delete any blocks that were only used by handlers that were outlined above.
if (TempAlloca == getCatchObjectSentinel())
continue; // Skip catch parameter sentinels.
Function *HandlerFn = TempAlloca->getParent()->getParent();
- // FIXME: Sink this GEP into the blocks where it is used.
+ llvm::Value *FP = HandlerToParentFP[HandlerFn];
+ assert(FP);
+
+ // FIXME: Sink this framerecover into the blocks where it is used.
Builder.SetInsertPoint(TempAlloca);
Builder.SetCurrentDebugLocation(TempAlloca->getDebugLoc());
Value *RecoverArgs[] = {
- Builder.CreateBitCast(&F, Int8PtrType, ""),
- &(HandlerFn->getArgumentList().back()),
+ Builder.CreateBitCast(&F, Int8PtrType, ""), FP,
llvm::ConstantInt::get(Int32Type, AllocasToEscape.size() - 1)};
- Value *RecoveredAlloca = Builder.CreateCall(RecoverFrameFn, RecoverArgs);
+ Instruction *RecoveredAlloca =
+ Builder.CreateCall(RecoverFrameFn, RecoverArgs);
+
// Add a pointer bitcast if the alloca wasn't an i8.
if (RecoveredAlloca->getType() != TempAlloca->getType()) {
RecoveredAlloca->setName(Twine(TempAlloca->getName()) + ".i8");
- RecoveredAlloca =
- Builder.CreateBitCast(RecoveredAlloca, TempAlloca->getType());
+ RecoveredAlloca = cast<Instruction>(
+ Builder.CreateBitCast(RecoveredAlloca, TempAlloca->getType()));
}
TempAlloca->replaceAllUsesWith(RecoveredAlloca);
TempAlloca->removeFromParent();
Builder.SetInsertPoint(&F.getEntryBlock().back());
Builder.CreateCall(FrameEscapeFn, AllocasToEscape);
+ if (SEHExceptionCodeSlot) {
+ if (isAllocaPromotable(SEHExceptionCodeSlot)) {
+ SmallPtrSet<BasicBlock *, 4> UserBlocks;
+ for (User *U : SEHExceptionCodeSlot->users()) {
+ if (auto *Inst = dyn_cast<Instruction>(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
DeleteContainerSeconds(CatchHandlerMap);
CatchHandlerMap.clear();
DeleteContainerSeconds(CleanupHandlerMap);
CleanupHandlerMap.clear();
+ HandlerToParentFP.clear();
+ DT = nullptr;
+ LibInfo = nullptr;
+ SEHExceptionCodeSlot = nullptr;
+ EHBlocks.clear();
+ NormalBlocks.clear();
+ EHReturnBlocks.clear();
return HandlersOutlined;
}
RecursivelyDeleteTriviallyDeadInstructions(U);
}
+void WinEHPrepare::getPossibleReturnTargets(Function *ParentF,
+ Function *HandlerF,
+ SetVector<BasicBlock*> &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<IntrinsicInst>(LPI->getNextNode());
+ SmallVector<std::unique_ptr<ActionHandler>, 4> ActionList;
+ parseEHActions(Recover, ActionList);
+ for (const auto &Action : ActionList) {
+ if (auto *CH = dyn_cast<CatchHandler>(Action.get())) {
+ Function *NestedF = cast<Function>(CH->getHandlerBlockOrFunc());
+ getPossibleReturnTargets(ParentF, NestedF, Targets);
+ }
+ }
+ }
+
+ auto *Ret = dyn_cast<ReturnInst>(BB.getTerminator());
+ if (!Ret)
+ continue;
+
+ // Handler functions must always return a block address.
+ BlockAddress *BA = cast<BlockAddress>(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,
// temporarily inserted as its terminator.
LLVMContext &Context = ParentFn->getContext();
BasicBlock *OutlinedBB = OutlinedLPad->getParent();
- assert(isa<UnreachableInst>(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<IndirectBrInst>(OutlinedBB->getTerminator());
+ if (!Branch) {
+ // If the landing pad wasn't in outlined form, it should be a stub with
+ // an unreachable terminator.
+ assert(isa<UnreachableInst>(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
++II;
// The instruction after the landing pad should now be a call to eh.actions.
const Instruction *Recover = II;
- assert(match(Recover, m_Intrinsic<Intrinsic::eh_actions>()));
- IntrinsicInst *EHActions = cast<IntrinsicInst>(Recover->clone());
+ const IntrinsicInst *EHActions = cast<IntrinsicInst>(Recover);
- // Remap the exception variables into the outlined function.
- WinEHFrameVariableMaterializer Materializer(OutlinedHandlerFn, FrameVarInfo);
+ // Remap the return target in the nested handler.
SmallVector<BlockAddress *, 4> ActionTargets;
- SmallVector<ActionHandler *, 4> ActionList;
+ SmallVector<std::unique_ptr<ActionHandler>, 4> ActionList;
parseEHActions(EHActions, ActionList);
- for (auto *Action : ActionList) {
- auto *Catch = dyn_cast<CatchHandler>(Action);
+ for (const auto &Action : ActionList) {
+ auto *Catch = dyn_cast<CatchHandler>(Action.get());
if (!Catch)
continue;
// The dyn_cast to function here selects C++ catch handlers and skips
// 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;
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<IntrinsicInst>(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
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");
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");
+ Function *ActionIntrin =
+ Intrinsic::getDeclaration(Handler->getParent(), Intrinsic::eh_actions);
+ Builder.CreateCall(ActionIntrin, {}, "recover");
LPad->setCleanup(true);
Builder.CreateUnreachable();
return StubBB;
// 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) {
else
Term = Unreached;
BasicBlock *OldRetBB = Term->getParent();
- BasicBlock *NewRetBB = SplitBlock(OldRetBB, Term);
+ BasicBlock *NewRetBB = SplitBlock(OldRetBB, Term, DT);
// SplitBlock adds an unconditional branch instruction at the end of the
// 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);
}
+// 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) {
+ // 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();
+ 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 {
+ FnType = FunctionType::get(RetTy, None, false);
+ }
+
+ Function *Handler =
+ Function::Create(FnType, GlobalVariable::InternalLinkage, Name, M);
+ BasicBlock *Entry = BasicBlock::Create(Context, "entry");
+ Handler->getBasicBlockList().push_front(Entry);
+ if (TheTriple.getArch() == Triple::x86_64) {
+ ParentFP = &(Handler->getArgumentList().back());
+ } else {
+ 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());
+ }
+ return Handler;
+}
+
bool WinEHPrepare::outlineHandler(ActionHandler *Action, Function *SrcFn,
LandingPadInst *LPad, BasicBlock *StartBB,
FrameVarInfoMap &VarInfo) {
Module *M = SrcFn->getParent();
LLVMContext &Context = M->getContext();
+ Type *Int8PtrType = Type::getInt8PtrTy(Context);
// Create a new function to receive the handler contents.
- Type *Int8PtrType = Type::getInt8PtrTy(Context);
- std::vector<Type *> ArgTys;
- ArgTys.push_back(Int8PtrType);
- ArgTys.push_back(Int8PtrType);
+ Value *ParentFP;
Function *Handler;
if (Action->getType() == Catch) {
- FunctionType *FnType = FunctionType::get(Int8PtrType, ArgTys, false);
- Handler = Function::Create(FnType, GlobalVariable::InternalLinkage,
- SrcFn->getName() + ".catch", M);
+ Handler = createHandlerFunc(Int8PtrType, SrcFn->getName() + ".catch", M,
+ ParentFP);
} else {
- FunctionType *FnType =
- FunctionType::get(Type::getVoidTy(Context), ArgTys, false);
- Handler = Function::Create(FnType, GlobalVariable::InternalLinkage,
- SrcFn->getName() + ".cleanup", M);
+ Handler = createHandlerFunc(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();
// Generate a standard prolog to setup the frame recovery structure.
IRBuilder<> Builder(Context);
- BasicBlock *Entry = BasicBlock::Create(Context, "entry");
- Handler->getBasicBlockList().push_front(Entry);
Builder.SetInsertPoint(Entry);
Builder.SetCurrentDebugLocation(LPad->getDebugLoc());
LPadMap.mapLandingPad(LPad);
if (auto *CatchAction = dyn_cast<CatchHandler>(Action)) {
Constant *Sel = CatchAction->getSelector();
- Director.reset(new WinEHCatchDirector(Handler, 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 {
- Director.reset(new WinEHCleanupDirector(Handler, VarInfo, LPadMap));
+ Director.reset(
+ new WinEHCleanupDirector(Handler, ParentFP, VarInfo, LPadMap));
LPadMap.remapEHValues(VMap, UndefValue::get(Int8PtrType),
UndefValue::get(Type::getInt32Ty(Context)));
}
/*ModuleLevelChanges=*/false, Returns, "",
&OutlinedFunctionInfo, Director.get());
- // Move all the instructions in the first cloned block into our entry block.
- BasicBlock *FirstClonedBB = std::next(Function::iterator(Entry));
- Entry->getInstList().splice(Entry->end(), FirstClonedBB->getInstList());
- FirstClonedBB->eraseFromParent();
+ // Move all the instructions in the cloned "entry" block into our entry block.
+ // Depending on how the parent function was laid out, the block that will
+ // correspond to the outlined entry block may not be the first block in the
+ // list. We can recognize it, however, as the cloned block which has no
+ // predecessors. Any other block wouldn't have been cloned if it didn't
+ // have a predecessor which was also cloned.
+ Function::iterator ClonedIt = std::next(Function::iterator(Entry));
+ while (!pred_empty(ClonedIt))
+ ++ClonedIt;
+ BasicBlock *ClonedEntryBB = ClonedIt;
+ assert(ClonedEntryBB);
+ Entry->getInstList().splice(Entry->end(), ClonedEntryBB->getInstList());
+ ClonedEntryBB->eraseFromParent();
// Make sure we can identify the handler's personality later.
- addStubInvokeToHandlerIfNeeded(Handler, LPad->getPersonalityFn());
+ addStubInvokeToHandlerIfNeeded(Handler);
if (auto *CatchAction = dyn_cast<CatchHandler>(Action)) {
WinEHCatchDirector *CatchDirector =
} else {
// This must be a catch-all. Split the block after the landingpad.
assert(CatchAction->getSelector()->isNullValue() && "expected catch-all");
- HandlerBB =
- StartBB->splitBasicBlock(StartBB->getFirstInsertionPt(), "catch.all");
+ HandlerBB = SplitBlock(StartBB, StartBB->getFirstInsertionPt(), DT);
}
+ IRBuilder<> Builder(HandlerBB->getFirstInsertionPt());
+ Function *EHCodeFn = Intrinsic::getDeclaration(
+ StartBB->getParent()->getParent(), Intrinsic::eh_exceptioncode);
+ Value *Code = Builder.CreateCall(EHCodeFn, {}, "sehcode");
+ Code = Builder.CreateIntToPtr(Code, SEHExceptionCodeSlot->getAllocatedType());
+ Builder.CreateStore(Code, SEHExceptionCodeSlot);
CatchAction->setHandlerBlockOrFunc(BlockAddress::get(HandlerBB));
TinyPtrVector<BasicBlock *> Targets(HandlerBB);
CatchAction->setReturnTargets(Targets);
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<LandingPadInst>(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<IndirectBrInst>(Inst)) {
+ return handleIndirectBr(VMap, IBr, NewBB);
+ }
+
if (auto *Invoke = dyn_cast<InvokeInst>(Inst))
return handleInvoke(VMap, Invoke, NewBB);
// When outlining llvm.frameaddress(i32 0), remap that to the second argument,
// which is the FP of the parent.
if (isFrameAddressCall(Inst)) {
- VMap[Inst] = EstablisherFrame;
+ VMap[Inst] = ParentFP;
return CloningDirector::SkipInstruction;
}
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<Intrinsic::eh_actions>()))
+ 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());
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<LandingPadInst>(VMap[LPad])] = LPad;
+
+ // We should only get here for landing pads that have already been outlined.
+ assert(match(LPad->getNextNode(), m_Intrinsic<Intrinsic::eh_actions>()));
+
+ // Copy the indirectbr, but only include targets that were previously
+ // identified as EH blocks and are dominated by the nested landing pad.
+ SetVector<const BasicBlock *> ReturnTargets;
+ for (int I = 0, E = IBr->getNumDestinations(); I < E; ++I) {
+ auto *TargetBB = IBr->getDestination(I);
+ if (EHBlocks.count(const_cast<BasicBlock*>(TargetBB)) &&
+ DT->dominates(ParentBB, TargetBB)) {
+ DEBUG(dbgs() << " Adding destination " << TargetBB->getName() << "\n");
+ ReturnTargets.insert(TargetBB);
+ }
+ }
+ IndirectBrInst *NewBranch =
+ IndirectBrInst::Create(const_cast<Value *>(IBr->getAddress()),
+ ReturnTargets.size(), NewBB);
+ for (auto *Target : ReturnTargets)
+ NewBranch->addDestination(const_cast<BasicBlock*>(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) {
const IntrinsicInst *IntrinCall = nullptr;
if (match(Compare->getOperand(0), m_Intrinsic<Intrinsic::eh_typeid_for>())) {
IntrinCall = dyn_cast<IntrinsicInst>(Compare->getOperand(0));
- } else if (match(Compare->getOperand(1), m_Intrinsic<Intrinsic::eh_typeid_for>())) {
+ } else if (match(Compare->getOperand(1),
+ m_Intrinsic<Intrinsic::eh_typeid_for>())) {
IntrinCall = dyn_cast<IntrinsicInst>(Compare->getOperand(1));
}
if (IntrinCall) {
// on the filter function we intend to match.
if (Selector == CurrentSelector->stripPointerCasts()) {
VMap[Compare] = ConstantInt::get(SelectorIDType, 1);
- }
- else {
+ } else {
VMap[Compare] = ConstantInt::get(SelectorIDType, 0);
}
return CloningDirector::SkipInstruction;
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.
return CloningDirector::SkipInstruction;
}
return CloningDirector::CloneInstruction;
-
}
WinEHFrameVariableMaterializer::WinEHFrameVariableMaterializer(
- Function *OutlinedFn, FrameVarInfoMap &FrameVarInfo)
+ Function *OutlinedFn, Value *ParentFP, FrameVarInfoMap &FrameVarInfo)
: FrameVarInfo(FrameVarInfo), Builder(OutlinedFn->getContext()) {
BasicBlock *EntryBB = &OutlinedFn->getEntryBlock();
- Builder.SetInsertPoint(EntryBB, EntryBB->getFirstInsertionPt());
+
+ // New allocas should be inserted in the entry block, but after the parent FP
+ // is established if it is an instruction.
+ Instruction *InsertPoint = EntryBB->getFirstInsertionPt();
+ if (auto *FPInst = dyn_cast<Instruction>(ParentFP))
+ InsertPoint = FPInst->getNextNode();
+ Builder.SetInsertPoint(EntryBB, InsertPoint);
}
Value *WinEHFrameVariableMaterializer::materializeValueFor(Value *V) {
}
if (isa<Instruction>(V) || isa<Argument>(V)) {
- errs() << "Failed to demote instruction used in exception handler:\n";
+ Function *Parent = isa<Instruction>(V)
+ ? cast<Instruction>(V)->getParent()->getParent()
+ : cast<Argument>(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");
}
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();
+ Constant *ExpectedSelector =
+ LPad->getClause(HandlersFound)->stripPointerCasts();
if (isa<ConstantPointerNull>(ExpectedSelector)) {
// The catch all must occur last.
assert(HandlersFound == NumClauses - 1);
Constant *Selector;
while (BB && isSelectorDispatch(BB, CatchBlock, Selector, NextBB)) {
DEBUG(dbgs() << " Found extra catch dispatch in block "
- << CatchBlock->getName() << "\n");
+ << CatchBlock->getName() << "\n");
BB = NextBB;
}
- // 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);
-
// Add the catch handler to the action list.
CatchHandler *Action = nullptr;
if (CatchHandlerMap.count(BB) && CatchHandlerMap[BB] != nullptr) {
Action = CatchHandlerMap[BB];
assert(Action->getSelector() == ExpectedSelector);
} else {
- // 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;
+ // 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");
if (auto *Action = CleanupHandlerMap[BB]) {
Actions.insertCleanupHandler(Action);
DEBUG(dbgs() << " Found cleanup code in block "
- << Action->getStartBlock()->getName() << "\n");
+ << Action->getStartBlock()->getName() << "\n");
// FIXME: This cleanup might chain into another, and we need to discover
// that.
return;
// 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
// for finally calls in the normal successor block.
BasicBlock *SuccBB = BB;
if (FinallyCall.getInstruction() != BB->getTerminator() &&
- FinallyCall.getInstruction()->getNextNode() != BB->getTerminator()) {
- SuccBB = BB->splitBasicBlock(FinallyCall.getInstruction()->getNextNode());
+ FinallyCall.getInstruction()->getNextNode() !=
+ BB->getTerminator()) {
+ SuccBB =
+ SplitBlock(BB, FinallyCall.getInstruction()->getNextNode(), DT);
} else {
if (FinallyCall.isInvoke()) {
- SuccBB = cast<InvokeInst>(FinallyCall.getInstruction())->getNormalDest();
+ SuccBB =
+ cast<InvokeInst>(FinallyCall.getInstruction())->getNormalDest();
} else {
SuccBB = BB->getUniqueSuccessor();
- assert(SuccBB && "splitOutlinedFinallyCalls didn't insert a branch");
+ assert(SuccBB &&
+ "splitOutlinedFinallyCalls didn't insert a branch");
}
}
BB = SuccBB;
// 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<ActionHandler *> &Actions) {
+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();
int64_t EHObjIndexVal = EHObjIndex->getSExtValue();
Constant *Handler = cast<Constant>(II->getArgOperand(I + 3));
I += 4;
- auto *CH = new CatchHandler(/*BB=*/nullptr, Selector, /*NextBB=*/nullptr);
+ auto CH = make_unique<CatchHandler>(/*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<Constant>(II->getArgOperand(I + 1));
I += 2;
- auto *CH = new CleanupHandler(/*BB=*/nullptr);
+ auto CH = make_unique<CleanupHandler>(/*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<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);
+};
+} // namespace
+
+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());
+}
projects / oota-llvm.git / blobdiff