//===----------------------------------------------------------------------===//
//
// 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/CFG.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/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PatternMatch.h"
+#include "llvm/MC/MCSymbol.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"
#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
public:
static char ID; // Pass identification, replacement for typeid.
WinEHPrepare(const TargetMachine *TM = nullptr)
- : FunctionPass(ID), DT(nullptr), SEHExceptionCodeSlot(nullptr) {}
+ : FunctionPass(ID) {
+ if (TM)
+ TheTriple = 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(Function *ParentFn, Type *RetTy,
+ const Twine &Name, Module *M, Value *&ParentFP);
bool outlineHandler(ActionHandler *Action, Function *SrcFn,
LandingPadInst *LPad, BasicBlock *StartBB,
FrameVarInfoMap &VarInfo);
- void addStubInvokeToHandlerIfNeeded(Function *Handler, Value *PersonalityFn);
+ void addStubInvokeToHandlerIfNeeded(Function *Handler);
void mapLandingPadBlocks(LandingPadInst *LPad, LandingPadActions &Actions);
CatchHandler *findCatchHandler(BasicBlock *BB, BasicBlock *&NextBB,
BasicBlock *EndBB);
void processSEHCatchHandler(CatchHandler *Handler, BasicBlock *StartBB);
+ void insertPHIStores(PHINode *OriginalPHI, AllocaInst *SpillSlot);
+ void
+ insertPHIStore(BasicBlock *PredBlock, Value *PredVal, AllocaInst *SpillSlot,
+ SmallVectorImpl<std::pair<BasicBlock *, Value *>> &Worklist);
+ AllocaInst *insertPHILoads(PHINode *PN, Function &F);
+ void replaceUseWithLoad(Value *V, Use &U, AllocaInst *&SpillSlot,
+ DenseMap<BasicBlock *, Value *> &Loads, Function &F);
+ void demoteNonlocalUses(Value *V, std::set<BasicBlock *> &ColorsForBB,
+ 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;
// 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 but before the outlined code is pruned from the parent function.
DenseMap<const BasicBlock *, BasicBlock *> LPadTargetBlocks;
- AllocaInst *SEHExceptionCodeSlot;
+ // Map from outlined handler to call to parent local address. Only used for
+ // 32-bit EH.
+ DenseMap<Function *, Value *> HandlerToParentFP;
+
+ AllocaInst *SEHExceptionCodeSlot = nullptr;
+
+ std::map<BasicBlock *, std::set<BasicBlock *>> BlockColors;
+ std::map<BasicBlock *, std::set<BasicBlock *>> FuncletBlocks;
+ std::map<BasicBlock *, std::set<BasicBlock *>> FuncletChildren;
};
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);
}
-bool WinEHPrepare::runOnFunction(Function &Fn) {
- // No need to prepare outlined handlers.
- if (Fn.hasFnAttribute("wineh-parent"))
- return false;
-
- SmallVector<LandingPadInst *, 4> LPads;
- SmallVector<ResumeInst *, 4> Resumes;
+static bool
+findExceptionalConstructs(Function &Fn,
+ SmallVectorImpl<LandingPadInst *> &LPads,
+ SmallVectorImpl<ResumeInst *> &Resumes,
+ SmallVectorImpl<BasicBlock *> &EntryBlocks) {
+ bool ForExplicitEH = false;
for (BasicBlock &BB : Fn) {
- if (auto *LP = BB.getLandingPadInst())
+ 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;
+}
- // No need to prepare functions that lack landing pads.
- if (LPads.empty())
+bool WinEHPrepare::runOnFunction(Function &Fn) {
+ if (!Fn.hasPersonalityFn())
+ return false;
+
+ // 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))
+ // 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 =
+ findExceptionalConstructs(Fn, LPads, Resumes, EntryBlocks);
+
+ if (ForExplicitEH)
+ return prepareExplicitEH(Fn, EntryBlocks);
+
+ // No need to prepare functions that lack landing pads.
+ if (LPads.empty())
return false;
DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+ 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
BasicBlock *NextBB;
Constant *Selector;
if (isSelectorDispatch(BB, CatchHandler, Selector, NextBB)) {
- // Split the edge if there is a phi node. Returning from EH to a phi node
- // is just as impossible as having a phi after an indirectbr.
- if (isa<PHINode>(CatchHandler->begin())) {
+ // Split the edge if there are multiple predecessors. This creates a place
+ // where we can insert EH recovery code.
+ if (!CatchHandler->getSinglePredecessor()) {
DEBUG(dbgs() << "splitting EH return edge from " << BB->getName()
<< " to " << CatchHandler->getName() << '\n');
BBI = CatchHandler = SplitCriticalEdge(
}
}
-/// 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());
+
+ // Try to avoid demoting EH pointer and selector values. They get in the way
+ // of our pattern matching.
+ SmallPtrSet<Instruction *, 10> EHVals;
+ for (BasicBlock &BB : F) {
+ LandingPadInst *LP = BB.getLandingPadInst();
+ if (!LP)
+ continue;
+ EHVals.insert(LP);
+ for (User *U : LP->users()) {
+ auto *EI = dyn_cast<ExtractValueInst>(U);
+ if (!EI)
+ continue;
+ EHVals.insert(EI);
+ for (User *U2 : EI->users()) {
+ if (auto *PN = dyn_cast<PHINode>(U2))
+ EHVals.insert(PN);
+ }
+ }
+ }
+
SetVector<Argument *> ArgsToDemote;
SetVector<Instruction *> InstrsToDemote;
for (BasicBlock &BB : F) {
continue;
}
+ // Don't demote EH values.
auto *OpI = cast<Instruction>(Op);
+ if (EHVals.count(OpI))
+ continue;
+
BasicBlock *OpBB = OpI->getParent();
// If a value is produced and consumed in the same BB, we don't need to
// demote it.
return false;
}
+ identifyEHBlocks(F, LPads);
demoteValuesLiveAcrossHandlers(F, LPads);
// These containers are used to re-map frame variables that are used in
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;
// 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");
- LPadBB->splitBasicBlock(LPad->getNextNode(),
- LPadBB->getName() + ".prepsplit");
+ SplitBlock(LPadBB, LPad->getNextNode(), DT);
// Erase the branch inserted by the split so we can insert indirectbr.
LPadBB->getTerminator()->eraseFromParent();
LPad->replaceAllUsesWith(UndefValue::get(LPad->getType()));
// Rewrite uses of the exception pointer to loads of an alloca.
- for (Instruction *E : SEHCodeUses) {
+ while (!SEHCodeUses.empty()) {
+ Instruction *E = SEHCodeUses.pop_back_val();
SmallVector<Use *, 4> Uses;
for (Use &U : E->uses())
Uses.push_back(&U);
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));
+ SEHCodeUses.push_back(Phi);
else
- LI = new LoadInst(SEHExceptionCodeSlot, "sehcode", false, I);
- U->set(LI);
+ U->set(new LoadInst(SEHExceptionCodeSlot, "sehcode", false, I));
}
E->replaceAllUsesWith(UndefValue::get(E->getType()));
E->eraseFromParent();
CallInst *Recover =
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::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.
Builder.SetInsertPoint(Entry->getFirstInsertionPt());
Function *FrameEscapeFn =
- Intrinsic::getDeclaration(M, Intrinsic::frameescape);
+ Intrinsic::getDeclaration(M, Intrinsic::localescape);
Function *RecoverFrameFn =
- Intrinsic::getDeclaration(M, Intrinsic::framerecover);
+ Intrinsic::getDeclaration(M, Intrinsic::localrecover);
SmallVector<Value *, 8> AllocasToEscape;
- // Scan the entry block for an existing call to llvm.frameescape. We need to
+ // Scan the entry block for an existing call to llvm.localescape. We need to
// keep escaping those objects.
for (Instruction &I : F.front()) {
auto *II = dyn_cast<IntrinsicInst>(&I);
- if (II && II->getIntrinsicID() == Intrinsic::frameescape) {
+ if (II && II->getIntrinsicID() == Intrinsic::localescape) {
auto Args = II->arg_operands();
AllocasToEscape.append(Args.begin(), Args.end());
II->eraseFromParent();
}
// Finally, replace all of the temporary allocas for frame variables used in
- // the outlined handlers with calls to llvm.framerecover.
+ // the outlined handlers with calls to llvm.localrecover.
for (auto &VarInfoEntry : FrameVarInfo) {
Value *ParentVal = VarInfoEntry.first;
TinyPtrVector<AllocaInst *> &Allocas = VarInfoEntry.second;
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 localrecover 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();
}
} // End for each FrameVarInfo entry.
- // Insert 'call void (...)* @llvm.frameescape(...)' at the end of the entry
+ // Insert 'call void (...)* @llvm.localescape(...)' at the end of the entry
// block.
Builder.SetInsertPoint(&F.getEntryBlock().back());
Builder.CreateCall(FrameEscapeFn, AllocasToEscape);
if (SEHExceptionCodeSlot) {
- if (SEHExceptionCodeSlot->hasNUses(0))
- SEHExceptionCodeSlot->eraseFromParent();
- else
+ if (isAllocaPromotable(SEHExceptionCodeSlot)) {
+ 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
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(Function *ParentFn, Type *RetTy,
+ const Twine &Name, Module *M,
+ Value *&ParentFP) {
+ // x64 uses a two-argument prototype where the parent FP is the second
+ // argument. x86 uses no arguments, just the incoming EBP value.
+ LLVMContext &Context = M->getContext();
+ Type *Int8PtrType = Type::getInt8PtrTy(Context);
+ FunctionType *FnType;
+ if (TheTriple.getArch() == Triple::x86_64) {
+ Type *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);
+ Function *RecoverFPFn =
+ Intrinsic::getDeclaration(M, Intrinsic::x86_seh_recoverfp);
+ IRBuilder<> Builder(&Handler->getEntryBlock());
+ Value *EBP =
+ Builder.CreateCall(FrameAddressFn, {Builder.getInt32(1)}, "ebp");
+ Value *ParentI8Fn = Builder.CreateBitCast(ParentFn, Int8PtrType);
+ ParentFP = Builder.CreateCall(RecoverFPFn, {ParentI8Fn, EBP});
+ }
+ return Handler;
+}
+
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(SrcFn, 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(SrcFn, Type::getVoidTy(Context),
+ SrcFn->getName() + ".cleanup", M, ParentFP);
}
-
+ Handler->setPersonalityFn(SrcFn->getPersonalityFn());
+ HandlerToParentFP[Handler] = ParentFP;
Handler->addFnAttr("wineh-parent", SrcFn->getName());
+ BasicBlock *Entry = &Handler->getEntryBlock();
// 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)));
}
// 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));
+ Function::iterator ClonedIt = std::next(Function::iterator(Entry));
while (!pred_empty(ClonedIt))
++ClonedIt;
BasicBlock *ClonedEntryBB = ClonedIt;
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");
+ StartBB->getParent()->getParent(), Intrinsic::eh_exceptioncode_old);
+ Value *Code = Builder.CreateCall(EHCodeFn, {}, "sehcode");
Code = Builder.CreateIntToPtr(Code, SEHExceptionCodeSlot->getAllocatedType());
Builder.CreateStore(Code, SEHExceptionCodeSlot);
CatchAction->setHandlerBlockOrFunc(BlockAddress::get(HandlerBB));
VMap[Extract] = SelectorValue;
}
-static bool isFrameAddressCall(const Value *V) {
- return match(const_cast<Value *>(V),
- m_Intrinsic<Intrinsic::frameaddress>(m_SpecificInt(0)));
+static bool isLocalAddressCall(const Value *V) {
+ return match(const_cast<Value *>(V), m_Intrinsic<Intrinsic::localaddress>());
}
CloningDirector::CloningAction WinEHCloningDirectorBase::handleInstruction(
if (LPadMap.isLandingPadSpecificInst(Inst))
return CloningDirector::SkipInstruction;
- // Nested landing pads will be cloned as stubs, with just the
- // landingpad instruction and an unreachable instruction. When
- // all landingpads have been outlined, we'll replace this with the
- // llvm.eh.actions call and indirect branch created when the
- // landing pad was outlined.
+ // Nested landing pads that have not already been outlined will be cloned as
+ // stubs, with just the landingpad instruction and an unreachable instruction.
+ // When all landingpads have been outlined, we'll replace this with the
+ // llvm.eh.actions call and indirect branch created when the landing pad was
+ // outlined.
if (auto *LPad = dyn_cast<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);
if (match(Inst, m_Intrinsic<Intrinsic::eh_typeid_for>()))
return handleTypeIdFor(VMap, Inst, NewBB);
- // When outlining llvm.frameaddress(i32 0), remap that to the second argument,
+ // When outlining llvm.localaddress(), remap that to the second argument,
// which is the FP of the parent.
- if (isFrameAddressCall(Inst)) {
- VMap[Inst] = EstablisherFrame;
+ if (isLocalAddressCall(Inst)) {
+ 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 we're asked to materialize a static alloca, we temporarily create an
// alloca in the outlined function and add this to the FrameVarInfo map. When
// all the outlining is complete, we'll replace these temporary allocas with
- // calls to llvm.framerecover.
+ // calls to llvm.localrecover.
if (auto *AV = dyn_cast<AllocaInst>(V)) {
assert(AV->isStaticAlloca() &&
"cannot materialize un-demoted dynamic alloca");
}
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");
}
// of a catch parameter, add a sentinel to the multimap to indicate that it's
// used from another handler. This will prevent us from trying to sink the
// alloca into the handler and ensure that the catch parameter is present in
- // the call to llvm.frameescape.
+ // the call to llvm.localescape.
FrameVarInfo[V].push_back(getCatchObjectSentinel());
}
// 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");
// Under some circumstances optimized IR will flow unconditionally into a
// handler block without checking the selector. This can only happen if
// the landing pad has a catch-all handler and the handler for the
- // preceeding catch clause is identical to the catch-call handler
+ // preceding catch clause is identical to the catch-call handler
// (typically an empty catch). In this case, the handler must be shared
// by all remaining clauses.
if (isa<ConstantPointerNull>(
static CallSite matchOutlinedFinallyCall(BasicBlock *BB,
Instruction *MaybeCall) {
// Look for finally blocks that Clang has already outlined for us.
- // %fp = call i8* @llvm.frameaddress(i32 0)
+ // %fp = call i8* @llvm.localaddress()
// call void @"fin$parent"(iN 1, i8* %fp)
- if (isFrameAddressCall(MaybeCall) && MaybeCall != BB->getTerminator())
+ if (isLocalAddressCall(MaybeCall) && MaybeCall != BB->getTerminator())
MaybeCall = MaybeCall->getNextNode();
CallSite FinallyCall(MaybeCall);
if (!FinallyCall || FinallyCall.arg_size() != 2)
return CallSite();
if (!match(FinallyCall.getArgument(0), m_SpecificInt(1)))
return CallSite();
- if (!isFrameAddressCall(FinallyCall.getArgument(1)))
+ if (!isLocalAddressCall(FinallyCall.getArgument(1)))
return CallSite();
return FinallyCall;
}
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
MaybeCall = MaybeCall->getNextNode();
}
- // Look for outlined finally calls.
- if (CallSite FinallyCall = matchOutlinedFinallyCall(BB, MaybeCall)) {
- Function *Fin = FinallyCall.getCalledFunction();
- assert(Fin && "outlined finally call should be direct");
- auto *Action = new CleanupHandler(BB);
- Action->setHandlerBlockOrFunc(Fin);
- Actions.insertCleanupHandler(Action);
- CleanupHandlerMap[BB] = Action;
- DEBUG(dbgs() << " Found frontend-outlined finally call to "
- << Fin->getName() << " in block "
- << Action->getStartBlock()->getName() << "\n");
-
- // Split the block if there were more interesting instructions and look
- // for finally calls in the normal successor block.
- BasicBlock *SuccBB = BB;
- if (FinallyCall.getInstruction() != BB->getTerminator() &&
- FinallyCall.getInstruction()->getNextNode() != BB->getTerminator()) {
- SuccBB = BB->splitBasicBlock(FinallyCall.getInstruction()->getNextNode());
- } else {
- if (FinallyCall.isInvoke()) {
- SuccBB = cast<InvokeInst>(FinallyCall.getInstruction())->getNormalDest();
+ // Look for outlined finally calls on x64, since those happen to match the
+ // prototype provided by the runtime.
+ if (TheTriple.getArch() == Triple::x86_64) {
+ if (CallSite FinallyCall = matchOutlinedFinallyCall(BB, MaybeCall)) {
+ Function *Fin = FinallyCall.getCalledFunction();
+ assert(Fin && "outlined finally call should be direct");
+ auto *Action = new CleanupHandler(BB);
+ Action->setHandlerBlockOrFunc(Fin);
+ Actions.insertCleanupHandler(Action);
+ CleanupHandlerMap[BB] = Action;
+ DEBUG(dbgs() << " Found frontend-outlined finally call to "
+ << Fin->getName() << " in block "
+ << Action->getStartBlock()->getName() << "\n");
+
+ // Split the block if there were more interesting instructions and
+ // look for finally calls in the normal successor block.
+ BasicBlock *SuccBB = BB;
+ if (FinallyCall.getInstruction() != BB->getTerminator() &&
+ FinallyCall.getInstruction()->getNextNode() !=
+ BB->getTerminator()) {
+ SuccBB =
+ SplitBlock(BB, FinallyCall.getInstruction()->getNextNode(), DT);
} else {
- SuccBB = BB->getUniqueSuccessor();
- assert(SuccBB && "splitOutlinedFinallyCalls didn't insert a branch");
+ if (FinallyCall.isInvoke()) {
+ SuccBB = cast<InvokeInst>(FinallyCall.getInstruction())
+ ->getNormalDest();
+ } else {
+ SuccBB = BB->getUniqueSuccessor();
+ assert(SuccBB &&
+ "splitOutlinedFinallyCalls didn't insert a branch");
+ }
}
+ BB = SuccBB;
+ if (BB == EndBB)
+ return;
+ continue;
}
- BB = SuccBB;
- if (BB == EndBB)
- return;
- continue;
}
}
// 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());
}
+
+static int addUnwindMapEntry(WinEHFuncInfo &FuncInfo, int ToState,
+ const Value *V) {
+ WinEHUnwindMapEntry UME;
+ UME.ToState = ToState;
+ UME.Cleanup = V;
+ FuncInfo.UnwindMap.push_back(UME);
+ return FuncInfo.getLastStateNumber();
+}
+
+static void addTryBlockMapEntry(WinEHFuncInfo &FuncInfo, int TryLow,
+ int TryHigh, int CatchHigh,
+ ArrayRef<const CatchPadInst *> Handlers) {
+ WinEHTryBlockMapEntry TBME;
+ TBME.TryLow = TryLow;
+ TBME.TryHigh = TryHigh;
+ TBME.CatchHigh = CatchHigh;
+ assert(TBME.TryLow <= TBME.TryHigh);
+ for (const CatchPadInst *CPI : Handlers) {
+ WinEHHandlerType HT;
+ Constant *TypeInfo = cast<Constant>(CPI->getArgOperand(0));
+ if (TypeInfo->isNullValue())
+ HT.TypeDescriptor = nullptr;
+ 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 const CatchPadInst *getSingleCatchPadPredecessor(const BasicBlock *BB) {
+ for (const BasicBlock *PredBlock : predecessors(BB))
+ if (auto *CPI = dyn_cast<CatchPadInst>(PredBlock->getFirstNonPHI()))
+ return CPI;
+ 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
+// to. If the unwind edge came from an invoke, return null.
+static const BasicBlock *getEHPadFromPredecessor(const BasicBlock *BB) {
+ const TerminatorInst *TI = BB->getTerminator();
+ if (isa<InvokeInst>(TI))
+ return nullptr;
+ if (TI->isEHPad())
+ return BB;
+ return cast<CleanupReturnInst>(TI)->getCleanupPad()->getParent();
+}
+
+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
+ // respective catchendpad instruction.
+ if (isa<CatchPadInst>(FirstNonPHI))
+ return;
+
+ if (isa<CatchEndPadInst>(FirstNonPHI)) {
+ SmallVector<const CatchPadInst *, 2> Handlers;
+ 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(FirstTryPad))
+ if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
+ 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)))
+ calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, CatchLow);
+ int CatchHigh = FuncInfo.getLastStateNumber();
+ addTryBlockMapEntry(FuncInfo, TryLow, TryHigh, CatchHigh, Handlers);
+ DEBUG(dbgs() << "TryLow[" << FirstTryPad->getName() << "]: " << TryLow
+ << '\n');
+ DEBUG(dbgs() << "TryHigh[" << FirstTryPad->getName() << "]: " << TryHigh
+ << '\n');
+ DEBUG(dbgs() << "CatchHigh[" << FirstTryPad->getName() << "]: " << CatchHigh
+ << '\n');
+ } else if (isa<CleanupPadInst>(FirstNonPHI)) {
+ int CleanupState = addUnwindMapEntry(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)))
+ 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 {
+ llvm_unreachable("unexpected EH Pad!");
+ }
+}
+
+/// 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;
+
+ for (const BasicBlock &BB : *Fn) {
+ if (!BB.isEHPad())
+ continue;
+ if (BB.isLandingPad())
+ report_fatal_error("MSVC C++ EH cannot use landingpads");
+ const Instruction *FirstNonPHI = BB.getFirstNonPHI();
+ // 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;
+}
+
+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;
+ 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);
+ }
+
+ 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);
+
+ // Let's remove the terminatepad now that we've inserted the new
+ // instructions.
+ TPI->eraseFromParent();
+ }
+}
+
+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();
+
+ // Build up the color map, which maps each block to its set of 'colors'.
+ // For any block B, the "colors" of B are the set of funclets F (possibly
+ // including a root "funclet" representing the main function), such that
+ // F will need to directly contain B or a copy of B (where the term "directly
+ // contain" is used to distinguish from being "transitively contained" in
+ // a nested funclet).
+ // Use a CFG walk driven by a worklist of (block, color) pairs. The "color"
+ // sets attached during this processing to a block which is the entry of some
+ // funclet F is actually the set of F's parents -- i.e. the union of colors
+ // of all predecessors of F's entry. For all other blocks, the color sets
+ // are as defined above. A post-pass fixes up the block color map to reflect
+ // the same sense of "color" for funclet entries as for other blocks.
+
+ Worklist.push_back({EntryBlock, EntryBlock});
+
+ while (!Worklist.empty()) {
+ BasicBlock *Visiting;
+ BasicBlock *Color;
+ std::tie(Visiting, Color) = Worklist.pop_back_val();
+ Instruction *VisitingHead = Visiting->getFirstNonPHI();
+ 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 *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.
+ if (CatchPadInst *CatchPad = dyn_cast<CatchPadInst>(VisitingHead)) {
+ // Visit the normal successor with the color of the new EH pad, and
+ // visit the unwind successor with the color of the parent.
+ BasicBlock *NormalSucc = CatchPad->getNormalDest();
+ if (BlockColors[NormalSucc].insert(Visiting).second) {
+ Worklist.push_back({NormalSucc, Visiting});
+ }
+ BasicBlock *UnwindSucc = CatchPad->getUnwindDest();
+ if (BlockColors[UnwindSucc].insert(Color).second) {
+ Worklist.push_back({UnwindSucc, Color});
+ }
+ continue;
+ }
+ // Switch color to the current node, except for terminate pads which
+ // have no bodies and only unwind successors and so need their successors
+ // visited with the color of the parent.
+ if (!isa<TerminatePadInst>(VisitingHead))
+ Color = Visiting;
+ } 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) ||
+ 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())) {
+ // The catchendpad needs to be visited with the parent's color, not
+ // the current color. This will happen in the code above that visits
+ // any catchpad unwind successor with the parent color, so we can
+ // safely skip this successor here.
+ continue;
+ }
+ if (BlockColors[Succ].insert(Color).second) {
+ Worklist.push_back({Succ, Color});
+ }
+ }
+ }
+
+ // The processing above actually accumulated the parent set for this
+ // funclet into the color set for its entry; use the parent set to
+ // populate the children map, and reset the color set to include just
+ // the funclet itself (no instruction can target a funclet entry except on
+ // that transitions to the child funclet).
+ for (BasicBlock *FuncletEntry : EntryBlocks) {
+ std::set<BasicBlock *> &ColorMapItem = BlockColors[FuncletEntry];
+ for (BasicBlock *Parent : ColorMapItem)
+ FuncletChildren[Parent].insert(FuncletEntry);
+ ColorMapItem.clear();
+ ColorMapItem.insert(FuncletEntry);
+ }
+}
+
+void WinEHPrepare::colorFunclets(Function &F,
+ SmallVectorImpl<BasicBlock *> &EntryBlocks) {
+ ::colorFunclets(F, EntryBlocks, BlockColors, FuncletBlocks, FuncletChildren);
+}
+
+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;) {
+ BasicBlock *BB = FI++;
+ if (!BB->isEHPad())
+ continue;
+ for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE;) {
+ Instruction *I = BI++;
+ auto *PN = dyn_cast<PHINode>(I);
+ // Stop at the first non-PHI.
+ if (!PN)
+ break;
+
+ AllocaInst *SpillSlot = insertPHILoads(PN, F);
+ if (SpillSlot)
+ insertPHIStores(PN, SpillSlot);
+
+ PHINodes.push_back(PN);
+ }
+ }
+
+ for (auto *PN : PHINodes) {
+ // There may be lingering uses on other EH PHIs being removed
+ 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++;
+ std::set<BasicBlock *> &ColorsForBB = BlockColors[BB];
+ for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE;) {
+ Instruction *I = BI++;
+ // Funclets are permitted to use static allocas.
+ if (auto *AI = dyn_cast<AllocaInst>(I))
+ if (AI->isStaticAlloca())
+ continue;
+
+ 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.
+ for (BasicBlock *FuncletPadBB : EntryBlocks) {
+ std::set<BasicBlock *> &BlocksInFunclet = FuncletBlocks[FuncletPadBB];
+
+ std::map<BasicBlock *, BasicBlock *> Orig2Clone;
+ ValueToValueMapTy VMap;
+ for (BasicBlock *BB : BlocksInFunclet) {
+ std::set<BasicBlock *> &ColorsForBB = BlockColors[BB];
+ // We don't need to do anything if the block is monochromatic.
+ size_t NumColorsForBB = ColorsForBB.size();
+ if (NumColorsForBB == 1)
+ continue;
+
+ // Create a new basic block and copy instructions into it!
+ BasicBlock *CBB =
+ CloneBasicBlock(BB, VMap, Twine(".for.", FuncletPadBB->getName()));
+ // Insert the clone immediately after the original to ensure determinism
+ // and to keep the same relative ordering of any funclet's blocks.
+ CBB->insertInto(&F, BB->getNextNode());
+
+ // Add basic block mapping.
+ VMap[BB] = CBB;
+
+ // Record delta operations that we need to perform to our color mappings.
+ Orig2Clone[BB] = CBB;
+ }
+
+ // Update our color mappings to reflect that one block has lost a color and
+ // another has gained a color.
+ for (auto &BBMapping : Orig2Clone) {
+ BasicBlock *OldBlock = BBMapping.first;
+ BasicBlock *NewBlock = BBMapping.second;
+
+ BlocksInFunclet.insert(NewBlock);
+ BlockColors[NewBlock].insert(FuncletPadBB);
+
+ BlocksInFunclet.erase(OldBlock);
+ BlockColors[OldBlock].erase(FuncletPadBB);
+ }
+
+ // Loop over all of the instructions in the function, fixing up operand
+ // references as we go. This uses VMap to do all the hard work.
+ for (BasicBlock *BB : BlocksInFunclet)
+ // 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;
+ std::set<BasicBlock *> &BlocksInFunclet = Funclet.second;
+ Instruction *FirstNonPHI = FuncletPadBB->getFirstNonPHI();
+ auto *CatchPad = dyn_cast<CatchPadInst>(FirstNonPHI);
+ auto *CleanupPad = dyn_cast<CleanupPadInst>(FirstNonPHI);
+
+ for (BasicBlock *BB : BlocksInFunclet) {
+ TerminatorInst *TI = BB->getTerminator();
+ // CatchPadInst and CleanupPadInst can't transfer control to a ReturnInst.
+ bool IsUnreachableRet = isa<ReturnInst>(TI) && (CatchPad || CleanupPad);
+ // The token consumed by a CatchReturnInst must match the funclet token.
+ bool IsUnreachableCatchret = false;
+ if (auto *CRI = dyn_cast<CatchReturnInst>(TI))
+ IsUnreachableCatchret = CRI->getCatchPad() != CatchPad;
+ // 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;
+ // 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;) {
+ BasicBlock *BB = FI++;
+ SimplifyInstructionsInBlock(BB);
+ ConstantFoldTerminator(BB, /*DeleteDeadConditions=*/true);
+ MergeBlockIntoPredecessor(BB);
+ }
+
+ // 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();
+ assert(NumColors == 1 && "Expected monochromatic BB!");
+ if (NumColors == 0)
+ report_fatal_error("Uncolored BB!");
+ if (NumColors > 1)
+ report_fatal_error("Multicolor BB!");
+ 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();
+ FuncletChildren.clear();
+
+ return true;
+}
+
+// TODO: Share loads when one use dominates another, or when a catchpad exit
+// dominates uses (needs dominators).
+AllocaInst *WinEHPrepare::insertPHILoads(PHINode *PN, Function &F) {
+ BasicBlock *PHIBlock = PN->getParent();
+ AllocaInst *SpillSlot = nullptr;
+
+ if (isa<CleanupPadInst>(PHIBlock->getFirstNonPHI())) {
+ // Insert a load in place of the PHI and replace all uses.
+ SpillSlot = new AllocaInst(PN->getType(), nullptr,
+ Twine(PN->getName(), ".wineh.spillslot"),
+ F.getEntryBlock().begin());
+ Value *V = new LoadInst(SpillSlot, Twine(PN->getName(), ".wineh.reload"),
+ PHIBlock->getFirstInsertionPt());
+ PN->replaceAllUsesWith(V);
+ return SpillSlot;
+ }
+
+ DenseMap<BasicBlock *, Value *> Loads;
+ for (Value::use_iterator UI = PN->use_begin(), UE = PN->use_end();
+ UI != UE;) {
+ Use &U = *UI++;
+ auto *UsingInst = cast<Instruction>(U.getUser());
+ BasicBlock *UsingBB = UsingInst->getParent();
+ if (UsingBB->isEHPad()) {
+ // Use is on an EH pad phi. Leave it alone; we'll insert loads and
+ // stores for it separately.
+ assert(isa<PHINode>(UsingInst));
+ continue;
+ }
+ replaceUseWithLoad(PN, U, SpillSlot, Loads, F);
+ }
+ return SpillSlot;
+}
+
+// TODO: improve store placement. Inserting at def is probably good, but need
+// to be careful not to introduce interfering stores (needs liveness analysis).
+// TODO: identify related phi nodes that can share spill slots, and share them
+// (also needs liveness).
+void WinEHPrepare::insertPHIStores(PHINode *OriginalPHI,
+ AllocaInst *SpillSlot) {
+ // Use a worklist of (Block, Value) pairs -- the given Value needs to be
+ // stored to the spill slot by the end of the given Block.
+ SmallVector<std::pair<BasicBlock *, Value *>, 4> Worklist;
+
+ Worklist.push_back({OriginalPHI->getParent(), OriginalPHI});
+
+ while (!Worklist.empty()) {
+ BasicBlock *EHBlock;
+ Value *InVal;
+ std::tie(EHBlock, InVal) = Worklist.pop_back_val();
+
+ PHINode *PN = dyn_cast<PHINode>(InVal);
+ if (PN && PN->getParent() == EHBlock) {
+ // The value is defined by another PHI we need to remove, with no room to
+ // insert a store after the PHI, so each predecessor needs to store its
+ // incoming value.
+ for (unsigned i = 0, e = PN->getNumIncomingValues(); i < e; ++i) {
+ Value *PredVal = PN->getIncomingValue(i);
+
+ // Undef can safely be skipped.
+ if (isa<UndefValue>(PredVal))
+ continue;
+
+ insertPHIStore(PN->getIncomingBlock(i), PredVal, SpillSlot, Worklist);
+ }
+ } else {
+ // We need to store InVal, which dominates EHBlock, but can't put a store
+ // in EHBlock, so need to put stores in each predecessor.
+ for (BasicBlock *PredBlock : predecessors(EHBlock)) {
+ insertPHIStore(PredBlock, InVal, SpillSlot, Worklist);
+ }
+ }
+ }
+}
+
+void WinEHPrepare::insertPHIStore(
+ BasicBlock *PredBlock, Value *PredVal, AllocaInst *SpillSlot,
+ SmallVectorImpl<std::pair<BasicBlock *, Value *>> &Worklist) {
+
+ if (PredBlock->isEHPad() &&
+ !isa<CleanupPadInst>(PredBlock->getFirstNonPHI())) {
+ // Pred is unsplittable, so we need to queue it on the worklist.
+ Worklist.push_back({PredBlock, PredVal});
+ return;
+ }
+
+ // Otherwise, insert the store at the end of the basic block.
+ new StoreInst(PredVal, SpillSlot, PredBlock->getTerminator());
+}
+
+// TODO: Share loads for same-funclet uses (requires dominators if funclets
+// aren't properly nested).
+void WinEHPrepare::demoteNonlocalUses(Value *V,
+ std::set<BasicBlock *> &ColorsForBB,
+ Function &F) {
+ // Tokens can only be used non-locally due to control flow involving
+ // unreachable edges. Don't try to demote the token usage, we'll simply
+ // delete the cloned user later.
+ if (isa<CatchPadInst>(V) || isa<CleanupPadInst>(V))
+ return;
+
+ DenseMap<BasicBlock *, Value *> Loads;
+ AllocaInst *SpillSlot = nullptr;
+ for (Value::use_iterator UI = V->use_begin(), UE = V->use_end(); UI != UE;) {
+ Use &U = *UI++;
+ auto *UsingInst = cast<Instruction>(U.getUser());
+ BasicBlock *UsingBB = UsingInst->getParent();
+
+ // Is the Use inside a block which is colored the same as the Def?
+ // If so, we don't need to escape the Def because we will clone
+ // ourselves our own private copy.
+ std::set<BasicBlock *> &ColorsForUsingBB = BlockColors[UsingBB];
+ if (ColorsForUsingBB == ColorsForBB)
+ continue;
+
+ replaceUseWithLoad(V, U, SpillSlot, Loads, F);
+ }
+ if (SpillSlot) {
+ // Insert stores of the computed value into the stack slot.
+ // We have to be careful if I is an invoke instruction,
+ // because we can't insert the store AFTER the terminator instruction.
+ BasicBlock::iterator InsertPt;
+ if (isa<Argument>(V)) {
+ InsertPt = F.getEntryBlock().getTerminator();
+ } else if (isa<TerminatorInst>(V)) {
+ auto *II = cast<InvokeInst>(V);
+ // We cannot demote invoke instructions to the stack if their normal
+ // edge is critical. Therefore, split the critical edge and create a
+ // basic block into which the store can be inserted.
+ if (!II->getNormalDest()->getSinglePredecessor()) {
+ unsigned SuccNum =
+ GetSuccessorNumber(II->getParent(), II->getNormalDest());
+ assert(isCriticalEdge(II, SuccNum) && "Expected a critical edge!");
+ BasicBlock *NewBlock = SplitCriticalEdge(II, SuccNum);
+ assert(NewBlock && "Unable to split critical edge.");
+ // Update the color mapping for the newly split edge.
+ std::set<BasicBlock *> &ColorsForUsingBB = BlockColors[II->getParent()];
+ BlockColors[NewBlock] = ColorsForUsingBB;
+ for (BasicBlock *FuncletPad : ColorsForUsingBB)
+ FuncletBlocks[FuncletPad].insert(NewBlock);
+ }
+ InsertPt = II->getNormalDest()->getFirstInsertionPt();
+ } else {
+ InsertPt = cast<Instruction>(V);
+ ++InsertPt;
+ // Don't insert before PHI nodes or EH pad instrs.
+ for (; isa<PHINode>(InsertPt) || InsertPt->isEHPad(); ++InsertPt)
+ ;
+ }
+ new StoreInst(V, SpillSlot, InsertPt);
+ }
+}
+
+void WinEHPrepare::replaceUseWithLoad(Value *V, Use &U, AllocaInst *&SpillSlot,
+ DenseMap<BasicBlock *, Value *> &Loads,
+ Function &F) {
+ // Lazilly create the spill slot.
+ if (!SpillSlot)
+ SpillSlot = new AllocaInst(V->getType(), nullptr,
+ Twine(V->getName(), ".wineh.spillslot"),
+ F.getEntryBlock().begin());
+
+ auto *UsingInst = cast<Instruction>(U.getUser());
+ if (auto *UsingPHI = dyn_cast<PHINode>(UsingInst)) {
+ // If this is a PHI node, we can't insert a load of the value before
+ // the use. Instead insert the load in the predecessor block
+ // corresponding to the incoming value.
+ //
+ // Note that if there are multiple edges from a basic block to this
+ // PHI node that we cannot have multiple loads. The problem is that
+ // the resulting PHI node will have multiple values (from each load)
+ // coming in from the same block, which is illegal SSA form.
+ // For this reason, we keep track of and reuse loads we insert.
+ BasicBlock *IncomingBlock = UsingPHI->getIncomingBlock(U);
+ if (auto *CatchRet =
+ dyn_cast<CatchReturnInst>(IncomingBlock->getTerminator())) {
+ // Putting a load above a catchret and use on the phi would still leave
+ // a cross-funclet def/use. We need to split the edge, change the
+ // catchret to target the new block, and put the load there.
+ BasicBlock *PHIBlock = UsingInst->getParent();
+ BasicBlock *NewBlock = SplitEdge(IncomingBlock, PHIBlock);
+ // SplitEdge gives us:
+ // IncomingBlock:
+ // ...
+ // br label %NewBlock
+ // NewBlock:
+ // catchret label %PHIBlock
+ // But we need:
+ // IncomingBlock:
+ // ...
+ // catchret label %NewBlock
+ // NewBlock:
+ // br label %PHIBlock
+ // So move the terminators to each others' blocks and swap their
+ // successors.
+ BranchInst *Goto = cast<BranchInst>(IncomingBlock->getTerminator());
+ Goto->removeFromParent();
+ CatchRet->removeFromParent();
+ IncomingBlock->getInstList().push_back(CatchRet);
+ NewBlock->getInstList().push_back(Goto);
+ Goto->setSuccessor(0, PHIBlock);
+ CatchRet->setSuccessor(NewBlock);
+ // Update the color mapping for the newly split edge.
+ std::set<BasicBlock *> &ColorsForPHIBlock = BlockColors[PHIBlock];
+ BlockColors[NewBlock] = ColorsForPHIBlock;
+ for (BasicBlock *FuncletPad : ColorsForPHIBlock)
+ FuncletBlocks[FuncletPad].insert(NewBlock);
+ // Treat the new block as incoming for load insertion.
+ IncomingBlock = NewBlock;
+ }
+ Value *&Load = Loads[IncomingBlock];
+ // Insert the load into the predecessor block
+ if (!Load)
+ Load = new LoadInst(SpillSlot, Twine(V->getName(), ".wineh.reload"),
+ /*Volatile=*/false, IncomingBlock->getTerminator());
+
+ U.set(Load);
+ } else {
+ // Reload right before the old use.
+ auto *Load = new LoadInst(SpillSlot, Twine(V->getName(), ".wineh.reload"),
+ /*Volatile=*/false, UsingInst);
+ 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