[WinEH] Calculate state numbers for the new EH representation

State numbers are calculated by performing a walk from the innermost
funclet to the outermost funclet.   Rudimentary support for the new EH
constructs has been added to the assembly printer, just enough to test
the new machinery.

Differential Revision: http://reviews.llvm.org/D12098

llvm-svn: 245331
This commit is contained in:
David Majnemer 2015-08-18 19:07:12 +00:00
parent 1378a5aec3
commit 0ad363eebc
8 changed files with 298 additions and 34 deletions

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@ -115,19 +115,20 @@ void parseEHActions(const IntrinsicInst *II,
struct WinEHUnwindMapEntry {
int ToState;
Function *Cleanup;
const Value *Cleanup;
};
struct WinEHHandlerType {
int Adjectives;
GlobalVariable *TypeDescriptor;
int CatchObjRecoverIdx;
Function *Handler;
const Value *Handler;
};
struct WinEHTryBlockMapEntry {
int TryLow;
int TryHigh;
int CatchHigh = -1;
SmallVector<WinEHHandlerType, 1> HandlerArray;
};
@ -136,7 +137,7 @@ struct WinEHFuncInfo {
DenseMap<const Function *, const InvokeInst *> LastInvoke;
DenseMap<const Function *, int> HandlerEnclosedState;
DenseMap<const Function *, bool> LastInvokeVisited;
DenseMap<const LandingPadInst *, int> LandingPadStateMap;
DenseMap<const Instruction *, int> EHPadStateMap;
DenseMap<const Function *, int> CatchHandlerParentFrameObjIdx;
DenseMap<const Function *, int> CatchHandlerParentFrameObjOffset;
DenseMap<const Function *, int> CatchHandlerMaxState;
@ -148,6 +149,8 @@ struct WinEHFuncInfo {
int UnwindHelpFrameOffset = -1;
unsigned NumIPToStateFuncsVisited = 0;
int getLastStateNumber() const { return UnwindMap.size() - 1; }
/// localescape index of the 32-bit EH registration node. Set by
/// WinEHStatePass and used indirectly by SEH filter functions of the parent.
int EHRegNodeEscapeIndex = INT_MAX;

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@ -182,10 +182,10 @@ const MCExpr *WinException::create32bitRef(const MCSymbol *Value) {
Asm->OutContext);
}
const MCExpr *WinException::create32bitRef(const GlobalValue *GV) {
if (!GV)
const MCExpr *WinException::create32bitRef(const Value *V) {
if (!V)
return MCConstantExpr::create(0, Asm->OutContext);
return create32bitRef(Asm->getSymbol(GV));
return create32bitRef(Asm->getSymbol(cast<GlobalValue>(V)));
}
/// Emit the language-specific data that __C_specific_handler expects. This
@ -413,7 +413,8 @@ void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
int CatchHigh = -1;
for (WinEHHandlerType &HT : TBME.HandlerArray)
CatchHigh =
std::max(CatchHigh, FuncInfo.CatchHandlerMaxState[HT.Handler]);
std::max(CatchHigh,
FuncInfo.CatchHandlerMaxState[cast<Function>(HT.Handler)]);
assert(TBME.TryLow <= TBME.TryHigh);
OS.EmitIntValue(TBME.TryLow, 4); // TryLow

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@ -18,9 +18,9 @@
namespace llvm {
class Function;
class GlobalValue;
class MachineFunction;
class MCExpr;
class Value;
struct WinEHFuncInfo;
class LLVM_LIBRARY_VISIBILITY WinException : public EHStreamer {
@ -56,7 +56,7 @@ class LLVM_LIBRARY_VISIBILITY WinException : public EHStreamer {
StringRef FLinkageName);
const MCExpr *create32bitRef(const MCSymbol *Value);
const MCExpr *create32bitRef(const GlobalValue *GV);
const MCExpr *create32bitRef(const Value *V);
public:
//===--------------------------------------------------------------------===//

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@ -283,7 +283,7 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
Personality == EHPersonality::MSVC_X86SEH) {
for (const LandingPadInst *LP : LPads) {
MachineBasicBlock *LPadMBB = MBBMap[LP->getParent()];
MMI.addWinEHState(LPadMBB, EHInfo.LandingPadStateMap[LP]);
MMI.addWinEHState(LPadMBB, EHInfo.EHPadStateMap[LP]);
}
}
}

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@ -2575,14 +2575,52 @@ struct WinEHNumbering {
};
}
void WinEHNumbering::createUnwindMapEntry(int ToState, ActionHandler *AH) {
static int addUnwindMapEntry(WinEHFuncInfo &FuncInfo, int ToState,
const Value *V) {
WinEHUnwindMapEntry UME;
UME.ToState = ToState;
if (auto *CH = dyn_cast_or_null<CleanupHandler>(AH))
UME.Cleanup = cast<Function>(CH->getHandlerBlockOrFunc());
else
UME.Cleanup = nullptr;
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.Adjectives = 0x40;
HT.TypeDescriptor = nullptr;
} else {
auto *GV = cast<GlobalVariable>(TypeInfo->stripPointerCasts());
// Selectors are always pointers to GlobalVariables with 'struct' type.
// The struct has two fields, adjectives and a type descriptor.
auto *CS = cast<ConstantStruct>(GV->getInitializer());
HT.Adjectives =
cast<ConstantInt>(CS->getAggregateElement(0U))->getZExtValue();
HT.TypeDescriptor =
cast<GlobalVariable>(CS->getAggregateElement(1)->stripPointerCasts());
}
HT.Handler = CPI->getParent();
// FIXME: Pass CPI->getArgOperand(1).
HT.CatchObjRecoverIdx = -1;
TBME.HandlerArray.push_back(HT);
}
FuncInfo.TryBlockMap.push_back(TBME);
}
void WinEHNumbering::createUnwindMapEntry(int ToState, ActionHandler *AH) {
Value *V = nullptr;
if (auto *CH = dyn_cast_or_null<CleanupHandler>(AH))
V = cast<Function>(CH->getHandlerBlockOrFunc());
addUnwindMapEntry(FuncInfo, ToState, V);
}
void WinEHNumbering::createTryBlockMapEntry(int TryLow, int TryHigh,
@ -2838,7 +2876,7 @@ void WinEHNumbering::calculateStateNumbers(const Function &F) {
continue;
processCallSite(ActionList, II);
ActionList.clear();
FuncInfo.LandingPadStateMap[LPI] = currentEHNumber();
FuncInfo.EHPadStateMap[LPI] = currentEHNumber();
DEBUG(dbgs() << "Assigning state " << currentEHNumber()
<< " to landing pad at " << LPI->getParent()->getName()
<< '\n');
@ -2902,10 +2940,114 @@ void WinEHNumbering::findActionRootLPads(const Function &F) {
}
}
static const BasicBlock *getSingleCatchPadPredecessor(const BasicBlock &BB) {
for (const BasicBlock *PredBlock : predecessors(&BB))
if (isa<CatchPadInst>(PredBlock->getFirstNonPHI()))
return PredBlock;
return nullptr;
}
// 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 (isa<CatchPadInst>(TI) || isa<CatchEndPadInst>(TI) ||
isa<TerminatePadInst>(TI))
return BB;
return cast<CleanupPadInst>(cast<CleanupReturnInst>(TI)->getReturnValue())
->getParent();
}
static void calculateExplicitStateNumbers(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)) {
const BasicBlock *TryPad = &BB;
const BasicBlock *LastTryPad = nullptr;
SmallVector<const CatchPadInst *, 2> Handlers;
do {
LastTryPad = TryPad;
TryPad = getSingleCatchPadPredecessor(*TryPad);
if (TryPad)
Handlers.push_back(cast<CatchPadInst>(TryPad->getFirstNonPHI()));
} while (TryPad);
// We've pushed these back into reverse source order. Reverse them to get
// the list back into source order.
std::reverse(Handlers.begin(), Handlers.end());
int TryLow = addUnwindMapEntry(FuncInfo, ParentState, nullptr);
FuncInfo.EHPadStateMap[Handlers.front()] = TryLow;
for (const BasicBlock *PredBlock : predecessors(LastTryPad))
if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
calculateExplicitStateNumbers(FuncInfo, *PredBlock, TryLow);
int CatchLow = addUnwindMapEntry(FuncInfo, ParentState, nullptr);
FuncInfo.EHPadStateMap[FirstNonPHI] = CatchLow;
int TryHigh = CatchLow - 1;
for (const BasicBlock *PredBlock : predecessors(&BB))
if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
calculateExplicitStateNumbers(FuncInfo, *PredBlock, CatchLow);
int CatchHigh = FuncInfo.getLastStateNumber();
addTryBlockMapEntry(FuncInfo, TryLow, TryHigh, CatchHigh, Handlers);
DEBUG(dbgs() << "TryLow[" << LastTryPad->getName() << "]: " << TryLow
<< '\n');
DEBUG(dbgs() << "TryHigh[" << LastTryPad->getName() << "]: " << TryHigh
<< '\n');
DEBUG(dbgs() << "CatchHigh[" << LastTryPad->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)))
calculateExplicitStateNumbers(FuncInfo, *PredBlock, CleanupState);
} else if (isa<TerminatePadInst>(FirstNonPHI)) {
report_fatal_error("Not yet implemented!");
} else {
llvm_unreachable("unexpected EH Pad!");
}
}
void llvm::calculateWinCXXEHStateNumbers(const Function *ParentFn,
WinEHFuncInfo &FuncInfo) {
// Return if it's already been done.
if (!FuncInfo.LandingPadStateMap.empty())
if (!FuncInfo.EHPadStateMap.empty())
return;
bool IsExplicit = false;
for (const BasicBlock &BB : *ParentFn) {
if (!BB.isEHPad())
continue;
// Check if the EH Pad has no exceptional successors (i.e. it unwinds to
// caller). Cleanups are a little bit of a special case because their
// control flow cannot be determined by looking at the pad but instead by
// the pad's users.
bool HasNoSuccessors = false;
const Instruction *FirstNonPHI = BB.getFirstNonPHI();
if (FirstNonPHI->mayThrow()) {
HasNoSuccessors = true;
} else if (auto *CPI = dyn_cast<CleanupPadInst>(FirstNonPHI)) {
HasNoSuccessors =
CPI->use_empty() ||
cast<CleanupReturnInst>(CPI->user_back())->unwindsToCaller();
}
if (!HasNoSuccessors)
continue;
calculateExplicitStateNumbers(FuncInfo, BB, -1);
IsExplicit = true;
}
if (IsExplicit)
return;
WinEHNumbering Num(FuncInfo);
@ -3141,6 +3283,7 @@ bool WinEHPrepare::prepareExplicitEH(Function &F) {
BlockColors.clear();
FuncletBlocks.clear();
return true;
}

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@ -28,10 +28,17 @@ static cl::opt<bool> EnableMachineCombinerPass("x86-machine-combiner",
cl::desc("Enable the machine combiner pass"),
cl::init(true), cl::Hidden);
namespace llvm {
void initializeWinEHStatePassPass(PassRegistry &);
}
extern "C" void LLVMInitializeX86Target() {
// Register the target.
RegisterTargetMachine<X86TargetMachine> X(TheX86_32Target);
RegisterTargetMachine<X86TargetMachine> Y(TheX86_64Target);
PassRegistry &PR = *PassRegistry::getPassRegistry();
initializeWinEHStatePassPass(PR);
}
static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {

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@ -38,12 +38,16 @@ using namespace llvm::PatternMatch;
#define DEBUG_TYPE "winehstate"
namespace llvm { void initializeWinEHStatePassPass(PassRegistry &); }
namespace {
class WinEHStatePass : public FunctionPass {
public:
static char ID; // Pass identification, replacement for typeid.
WinEHStatePass() : FunctionPass(ID) {}
WinEHStatePass() : FunctionPass(ID) {
initializeWinEHStatePassPass(*PassRegistry::getPassRegistry());
}
bool runOnFunction(Function &Fn) override;
@ -62,8 +66,8 @@ private:
void linkExceptionRegistration(IRBuilder<> &Builder, Function *Handler);
void unlinkExceptionRegistration(IRBuilder<> &Builder);
void addCXXStateStores(Function &F, MachineModuleInfo &MMI);
void addSEHStateStores(Function &F, MachineModuleInfo &MMI);
void addCXXStateStores(Function &F, WinEHFuncInfo &FuncInfo);
void addSEHStateStores(Function &F, WinEHFuncInfo &FuncInfo);
void addCXXStateStoresToFunclet(Value *ParentRegNode, WinEHFuncInfo &FuncInfo,
Function &F, int BaseState);
void insertStateNumberStore(Value *ParentRegNode, Instruction *IP, int State);
@ -111,6 +115,9 @@ FunctionPass *llvm::createX86WinEHStatePass() { return new WinEHStatePass(); }
char WinEHStatePass::ID = 0;
INITIALIZE_PASS(WinEHStatePass, "x86-winehstate",
"Insert stores for EH state numbers", false, false)
bool WinEHStatePass::doInitialization(Module &M) {
TheModule = &M;
FrameEscape = Intrinsic::getDeclaration(TheModule, Intrinsic::localescape);
@ -163,13 +170,23 @@ bool WinEHStatePass::runOnFunction(Function &F) {
emitExceptionRegistrationRecord(&F);
auto *MMIPtr = getAnalysisIfAvailable<MachineModuleInfo>();
assert(MMIPtr && "MachineModuleInfo should always be available");
MachineModuleInfo &MMI = *MMIPtr;
auto *MMI = getAnalysisIfAvailable<MachineModuleInfo>();
// If MMI is null, create our own WinEHFuncInfo. This only happens in opt
// tests.
std::unique_ptr<WinEHFuncInfo> FuncInfoPtr;
if (!MMI)
FuncInfoPtr.reset(new WinEHFuncInfo());
WinEHFuncInfo &FuncInfo =
*(MMI ? &MMI->getWinEHFuncInfo(&F) : FuncInfoPtr.get());
switch (Personality) {
default: llvm_unreachable("unexpected personality function");
case EHPersonality::MSVC_CXX: addCXXStateStores(F, MMI); break;
case EHPersonality::MSVC_X86SEH: addSEHStateStores(F, MMI); break;
case EHPersonality::MSVC_CXX:
addCXXStateStores(F, FuncInfo);
break;
case EHPersonality::MSVC_X86SEH:
addSEHStateStores(F, FuncInfo);
break;
}
// Reset per-function state.
@ -391,8 +408,7 @@ void WinEHStatePass::unlinkExceptionRegistration(IRBuilder<> &Builder) {
Builder.CreateStore(Next, FSZero);
}
void WinEHStatePass::addCXXStateStores(Function &F, MachineModuleInfo &MMI) {
WinEHFuncInfo &FuncInfo = MMI.getWinEHFuncInfo(&F);
void WinEHStatePass::addCXXStateStores(Function &F, WinEHFuncInfo &FuncInfo) {
calculateWinCXXEHStateNumbers(&F, FuncInfo);
// The base state for the parent is -1.
@ -466,10 +482,10 @@ void WinEHStatePass::addCXXStateStoresToFunclet(Value *ParentRegNode,
insertStateNumberStore(ParentRegNode, CI, BaseState);
} else if (auto *II = dyn_cast<InvokeInst>(&I)) {
// Look up the state number of the landingpad this unwinds to.
LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst();
Instruction *PadInst = II->getUnwindDest()->getFirstNonPHI();
// FIXME: Why does this assertion fail?
//assert(FuncInfo.LandingPadStateMap.count(LPI) && "LP has no state!");
int State = FuncInfo.LandingPadStateMap[LPI];
//assert(FuncInfo.EHPadStateMap.count(PadInst) && "EH Pad has no state!");
int State = FuncInfo.EHPadStateMap[PadInst];
insertStateNumberStore(ParentRegNode, II, State);
}
}
@ -481,9 +497,7 @@ void WinEHStatePass::addCXXStateStoresToFunclet(Value *ParentRegNode,
/// handlers aren't outlined and the runtime doesn't have to figure out which
/// catch handler frame to unwind to.
/// FIXME: __finally blocks are outlined, so this approach may break down there.
void WinEHStatePass::addSEHStateStores(Function &F, MachineModuleInfo &MMI) {
WinEHFuncInfo &FuncInfo = MMI.getWinEHFuncInfo(&F);
void WinEHStatePass::addSEHStateStores(Function &F, WinEHFuncInfo &FuncInfo) {
// Remember and return the index that we used. We save it in WinEHFuncInfo so
// that we can lower llvm.x86.seh.recoverfp later in filter functions without
// too much trouble.
@ -507,7 +521,7 @@ void WinEHStatePass::addSEHStateStores(Function &F, MachineModuleInfo &MMI) {
// Look up the state number of the landingpad this unwinds to.
LandingPadInst *LPI = II->getUnwindDest()->getLandingPadInst();
auto InsertionPair =
FuncInfo.LandingPadStateMap.insert(std::make_pair(LPI, CurState));
FuncInfo.EHPadStateMap.insert(std::make_pair(LPI, CurState));
auto Iter = InsertionPair.first;
int &State = Iter->second;
bool Inserted = InsertionPair.second;

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@ -0,0 +1,96 @@
; RUN: opt -mtriple=i686-pc-windows-msvc -S -x86-winehstate < %s | FileCheck %s
target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
target triple = "i686-pc-windows-msvc"
%rtti.TypeDescriptor2 = type { i8**, i8*, [3 x i8] }
%eh.CatchableType = type { i32, i8*, i32, i32, i32, i32, i8* }
%eh.CatchableTypeArray.1 = type { i32, [1 x %eh.CatchableType*] }
%eh.ThrowInfo = type { i32, i8*, i8*, i8* }
$"\01??_R0H@8" = comdat any
$"_CT??_R0H@84" = comdat any
$_CTA1H = comdat any
$_TI1H = comdat any
@"\01??_7type_info@@6B@" = external constant i8*
@"\01??_R0H@8" = linkonce_odr global %rtti.TypeDescriptor2 { i8** @"\01??_7type_info@@6B@", i8* null, [3 x i8] c".H\00" }, comdat
@"_CT??_R0H@84" = linkonce_odr unnamed_addr constant %eh.CatchableType { i32 1, i8* bitcast (%rtti.TypeDescriptor2* @"\01??_R0H@8" to i8*), i32 0, i32 -1, i32 0, i32 4, i8* null }, section ".xdata", comdat
@_CTA1H = linkonce_odr unnamed_addr constant %eh.CatchableTypeArray.1 { i32 1, [1 x %eh.CatchableType*] [%eh.CatchableType* @"_CT??_R0H@84"] }, section ".xdata", comdat
@_TI1H = linkonce_odr unnamed_addr constant %eh.ThrowInfo { i32 0, i8* null, i8* null, i8* bitcast (%eh.CatchableTypeArray.1* @_CTA1H to i8*) }, section ".xdata", comdat
define i32 @main() #0 personality i32 (...)* @__CxxFrameHandler3 {
entry:
%tmp = alloca i32, align 4
; CHECK: entry:
; CHECK: store i32 -1
; CHECK: call void @g(i32 3)
call void @g(i32 3)
store i32 0, i32* %tmp, align 4
%0 = bitcast i32* %tmp to i8*
; CHECK: store i32 0
; CHECK: invoke void @_CxxThrowException(
invoke void @_CxxThrowException(i8* %0, %eh.ThrowInfo* nonnull @_TI1H) #1
to label %unreachable.for.entry unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%1 = catchpad token [i8* null, i8* null] to label %catch unwind label %catchendblock
catch: ; preds = %catch.dispatch
; CHECK: catch:
; CHECK: store i32 2
; CHECK: invoke void @_CxxThrowException(
invoke void @_CxxThrowException(i8* null, %eh.ThrowInfo* null) #1
to label %unreachable unwind label %catch.dispatch.1
catch.dispatch.1: ; preds = %catch
%2 = catchpad token [i8* null, i8* null] to label %catch.3 unwind label %catchendblock.2
catch.3: ; preds = %catch.dispatch.1
; CHECK: catch.3:
; CHECK: store i32 3
; CHECK: invoke void @g(i32 1)
invoke void @g(i32 1)
to label %invoke.cont unwind label %catchendblock.2
invoke.cont: ; preds = %catch.3
catchret token %2 to label %try.cont
try.cont: ; preds = %invoke.cont
; CHECK: try.cont:
; CHECK: store i32 1
; CHECK: invoke void @g(i32 2)
invoke void @g(i32 2)
to label %invoke.cont.4 unwind label %catchendblock
invoke.cont.4: ; preds = %try.cont
unreachable
catchendblock.2: ; preds = %catch.3, %catch.dispatch.1
catchendpad unwind label %catchendblock
catchendblock: ; preds = %catchendblock.2, %try.cont, %catch.dispatch
catchendpad unwind to caller
unreachable: ; preds = %catch
unreachable
unreachable.for.entry: ; preds = %entry
unreachable
}
declare void @g(i32) #0
declare x86_stdcallcc void @_CxxThrowException(i8*, %eh.ThrowInfo*)
declare i32 @__CxxFrameHandler3(...)
attributes #0 = { "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { noreturn }
!llvm.ident = !{!0}
!0 = !{!"clang version 3.8.0 (trunk 245153) (llvm/trunk 245238)"}