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[SEH] Emit 32-bit SEH tables for the new EH IR

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The 32-bit tables don't actually contain PC range data, so emitting them
is incredibly simple.

The 64-bit tables, on the other hand, use the same table for state
numbering as well as label ranges. This makes things more difficult, so
it will be implemented later.

llvm-svn: 247192
This commit is contained in:
Reid Kleckner 2015-09-09 21:10:03 +00:00
parent c4e3274379
commit 40ce82e375
9 changed files with 522 additions and 103 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
include/llvm/CodeGen/WinEHFuncInfo.h
View File

@ -14,9 +14,10 @@
#ifndef LLVM_CODEGEN_WINEHFUNCINFO_H
#define LLVM_CODEGEN_WINEHFUNCINFO_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/TinyPtrVector.h"
#include "llvm/ADT/DenseMap.h"
namespace llvm {
class AllocaInst;
@ -120,17 +121,32 @@ struct WinEHUnwindMapEntry {
const Value *Cleanup;
};
typedef PointerUnion<const BasicBlock *, MachineBasicBlock *> MBBOrBasicBlock;
typedef PointerUnion<const Value *, MachineBasicBlock *> ValueOrMBB;
/// Similar to WinEHUnwindMapEntry, but supports SEH filters.
struct SEHUnwindMapEntry {
/// If unwinding continues through this handler, transition to the handler at
/// this state. This indexes into SEHUnwindMap.
int ToState = -1;
/// Holds the filter expression function.
const Function *Filter = nullptr;
/// Holds the __except or __finally basic block.
MBBOrBasicBlock Handler;
};
struct WinEHHandlerType {
int Adjectives;
GlobalVariable *TypeDescriptor;
int CatchObjRecoverIdx;
const Value *Handler;
MachineBasicBlock *HandlerMBB;
ValueOrMBB Handler;
};
struct WinEHTryBlockMapEntry {
int TryLow;
int TryHigh;
int TryLow = -1;
int TryHigh = -1;
int CatchHigh = -1;
SmallVector<WinEHHandlerType, 1> HandlerArray;
};
@ -147,6 +163,7 @@ struct WinEHFuncInfo {
DenseMap<const Function *, int> HandlerBaseState;
SmallVector<WinEHUnwindMapEntry, 4> UnwindMap;
SmallVector<WinEHTryBlockMapEntry, 4> TryBlockMap;
SmallVector<SEHUnwindMapEntry, 4> SEHUnwindMap;
SmallVector<std::pair<MCSymbol *, int>, 4> IPToStateList;
int UnwindHelpFrameIdx = INT_MAX;
int UnwindHelpFrameOffset = -1;
@ -169,5 +186,7 @@ struct WinEHFuncInfo {
void calculateWinCXXEHStateNumbers(const Function *ParentFn,
WinEHFuncInfo &FuncInfo);
void calculateSEHStateNumbers(const Function *ParentFn,
WinEHFuncInfo &FuncInfo);
}
#endif // LLVM_CODEGEN_WINEHFUNCINFO_H

52
lib/CodeGen/AsmPrinter/WinException.cpp
View File

@ -161,7 +161,7 @@ void WinException::endFunction(const MachineFunction *MF) {
// Emit the tables appropriate to the personality function in use. If we
// don't recognize the personality, assume it uses an Itanium-style LSDA.
if (Per == EHPersonality::MSVC_Win64SEH)
emitCSpecificHandlerTable();
emitCSpecificHandlerTable(MF);
else if (Per == EHPersonality::MSVC_X86SEH)
emitExceptHandlerTable(MF);
else if (Per == EHPersonality::MSVC_CXX)
@ -222,9 +222,13 @@ const MCExpr *WinException::create32bitRef(const Value *V) {
/// imagerel32 LabelLPad; // Zero means __finally.
/// } Entries[NumEntries];
/// };
void WinException::emitCSpecificHandlerTable() {
void WinException::emitCSpecificHandlerTable(const MachineFunction *MF) {
const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
WinEHFuncInfo &FuncInfo = MMI->getWinEHFuncInfo(MF->getFunction());
if (!FuncInfo.SEHUnwindMap.empty())
report_fatal_error("x64 SEH tables not yet implemented");
// Simplifying assumptions for first implementation:
// - Cleanups are not implemented.
// - Filters are not implemented.
@ -309,6 +313,15 @@ void WinException::emitCSpecificHandlerTable() {
}
}
/// Retreive the MCSymbol for a GlobalValue or MachineBasicBlock. GlobalValues
/// are used in the old WinEH scheme, and they will be removed eventually.
static MCSymbol *getMCSymbolForMBBOrGV(AsmPrinter *Asm, ValueOrMBB Handler) {
if (Handler.is<MachineBasicBlock *>())
return Handler.get<MachineBasicBlock *>()->getSymbol();
else
return Asm->getSymbol(cast<GlobalValue>(Handler.get<const Value *>()));
}
void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
const Function *F = MF->getFunction();
const Function *ParentF = MMI->getWinEHParent(F);
@ -422,9 +435,9 @@ void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
int CatchHigh = TBME.CatchHigh;
if (CatchHigh == -1) {
for (WinEHHandlerType &HT : TBME.HandlerArray)
CatchHigh = std::max(
CatchHigh,
FuncInfo.CatchHandlerMaxState[cast<Function>(HT.Handler)]);
CatchHigh =
std::max(CatchHigh, FuncInfo.CatchHandlerMaxState[cast<Function>(
HT.Handler.get<const Value *>())]);
}
assert(TBME.TryLow <= TBME.TryHigh);
@ -464,13 +477,12 @@ void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
FrameAllocOffsetRef = MCConstantExpr::create(0, Asm->OutContext);
}
OS.EmitIntValue(HT.Adjectives, 4); // Adjectives
OS.EmitValue(create32bitRef(HT.TypeDescriptor), 4); // Type
OS.EmitValue(FrameAllocOffsetRef, 4); // CatchObjOffset
if (HT.HandlerMBB) // Handler
OS.EmitValue(create32bitRef(HT.HandlerMBB->getSymbol()), 4);
else
OS.EmitValue(create32bitRef(HT.Handler), 4);
MCSymbol *HandlerSym = getMCSymbolForMBBOrGV(Asm, HT.Handler);
OS.EmitIntValue(HT.Adjectives, 4); // Adjectives
OS.EmitValue(create32bitRef(HT.TypeDescriptor), 4); // Type
OS.EmitValue(FrameAllocOffsetRef, 4); // CatchObjOffset
OS.EmitValue(create32bitRef(HandlerSym), 4); // Handler
if (shouldEmitPersonality) {
if (FuncInfo.CatchHandlerParentFrameObjOffset.empty()) {
@ -482,7 +494,8 @@ void WinException::emitCXXFrameHandler3Table(const MachineFunction *MF) {
} else {
MCSymbol *ParentFrameOffset =
Asm->OutContext.getOrCreateParentFrameOffsetSymbol(
GlobalValue::getRealLinkageName(HT.Handler->getName()));
GlobalValue::getRealLinkageName(
HT.Handler.get<const Value *>()->getName()));
const MCSymbolRefExpr *ParentFrameOffsetRef =
MCSymbolRefExpr::create(ParentFrameOffset, Asm->OutContext);
OS.EmitValue(ParentFrameOffsetRef, 4); // ParentFrameOffset
@ -642,6 +655,19 @@ void WinException::emitExceptHandlerTable(const MachineFunction *MF) {
BaseState = -2;
}
if (!FuncInfo.SEHUnwindMap.empty()) {
for (SEHUnwindMapEntry &UME : FuncInfo.SEHUnwindMap) {
MCSymbol *ExceptOrFinally =
UME.Handler.get<MachineBasicBlock *>()->getSymbol();
OS.EmitIntValue(UME.ToState, 4); // ToState
OS.EmitValue(create32bitRef(UME.Filter), 4); // Filter
OS.EmitValue(create32bitRef(ExceptOrFinally), 4); // Except/Finally
}
return;
}
// FIXME: The following code is for the old landingpad-based SEH
// implementation. Remove it when possible.
// Build a list of pointers to LandingPadInfos and then sort by WinEHState.
const std::vector<LandingPadInfo> &PadInfos = MMI->getLandingPads();
SmallVector<const LandingPadInfo *, 4> LPads;

2
lib/CodeGen/AsmPrinter/WinException.h
View File

@ -36,7 +36,7 @@ class LLVM_LIBRARY_VISIBILITY WinException : public EHStreamer {
/// True if this is a 64-bit target and we should use image relative offsets.
bool useImageRel32 = false;
void emitCSpecificHandlerTable();
void emitCSpecificHandlerTable(const MachineFunction *MF);
/// Emit the EH table data for 32-bit and 64-bit functions using
/// the __CxxFrameHandler3 personality.

26
lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
View File

@ -287,21 +287,31 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
addSEHHandlersForLPads(LPads);
}
// Calculate state numbers if we haven't already.
WinEHFuncInfo &EHInfo = MMI.getWinEHFuncInfo(&fn);
if (Personality == EHPersonality::MSVC_CXX) {
// Calculate state numbers and then map from funclet BBs to MBBs.
const Function *WinEHParentFn = MMI.getWinEHParent(&fn);
calculateWinCXXEHStateNumbers(WinEHParentFn, EHInfo);
} else {
const Function *WinEHParentFn = MMI.getWinEHParent(&fn);
calculateSEHStateNumbers(WinEHParentFn, EHInfo);
}
// Map all BB references in the EH data to MBBs.
for (WinEHTryBlockMapEntry &TBME : EHInfo.TryBlockMap)
for (WinEHHandlerType &H : TBME.HandlerArray)
if (const auto *BB = dyn_cast<BasicBlock>(H.Handler))
H.HandlerMBB = MBBMap[BB];
// If there's an explicit EH registration node on the stack, record its
// frame index.
if (EHInfo.EHRegNode && EHInfo.EHRegNode->getParent()->getParent() == Fn) {
assert(StaticAllocaMap.count(EHInfo.EHRegNode));
EHInfo.EHRegNodeFrameIndex = StaticAllocaMap[EHInfo.EHRegNode];
if (const auto *BB =
dyn_cast<BasicBlock>(H.Handler.get<const Value *>()))
H.Handler = MBBMap[BB];
for (SEHUnwindMapEntry &UME : EHInfo.SEHUnwindMap) {
const BasicBlock *BB = UME.Handler.get<const BasicBlock *>();
UME.Handler = MBBMap[BB];
}
// If there's an explicit EH registration node on the stack, record its
// frame index.
if (EHInfo.EHRegNode && EHInfo.EHRegNode->getParent()->getParent() == Fn) {
assert(StaticAllocaMap.count(EHInfo.EHRegNode));
EHInfo.EHRegNodeFrameIndex = StaticAllocaMap[EHInfo.EHRegNode];
}
// Copy the state numbers to LandingPadInfo for the current function, which

23
lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
View File

@ -1989,7 +1989,6 @@ void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {
// and catchendpads for successors.
MachineBasicBlock *Return = FuncInfo.MBBMap[I.getSuccessor(0)];
const BasicBlock *EHPadBB = I.getSuccessor(1);
bool IsLandingPad = EHPadBB->isLandingPad();
const Value *Callee(I.getCalledValue());
const Function *Fn = dyn_cast<Function>(Callee);
@ -2025,16 +2024,26 @@ void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {
// Catchpads are conditional branches that add real MBB destinations and
// continue the loop. EH "end" pads are not real BBs and simply continue.
SmallVector<MachineBasicBlock *, 1> UnwindDests;
bool IsMSVCCXX = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn()) ==
EHPersonality::MSVC_CXX;
while (EHPadBB) {
const Instruction *Pad = EHPadBB->getFirstNonPHI();
if (isa<CleanupPadInst>(Pad) || isa<LandingPadInst>(Pad)) {
assert(FuncInfo.MBBMap[EHPadBB]);
// Stop on cleanup pads and landingpads.
if (isa<LandingPadInst>(Pad)) {
// Stop on landingpads. They are not funclets.
UnwindDests.push_back(FuncInfo.MBBMap[EHPadBB]);
break;
} else if (isa<CleanupPadInst>(Pad) || isa<LandingPadInst>(Pad)) {
// Stop on cleanup pads. Cleanups are always funclet entries for all known
// personalities.
UnwindDests.push_back(FuncInfo.MBBMap[EHPadBB]);
UnwindDests.back()->setIsEHFuncletEntry();
break;
} else if (const auto *CPI = dyn_cast<CatchPadInst>(Pad)) {
// Add the catchpad handler to the possible destinations.
UnwindDests.push_back(FuncInfo.MBBMap[CPI->getNormalDest()]);
// In MSVC C++, catchblocks are funclets and need prologues.
if (IsMSVCCXX)
UnwindDests.back()->setIsEHFuncletEntry();
EHPadBB = CPI->getUnwindDest();
} else if (const auto *CEPI = dyn_cast<CatchEndPadInst>(Pad)) {
EHPadBB = CEPI->getUnwindDest();
@ -2043,13 +2052,11 @@ void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {
}
}
// Update successor info
// Update successor info.
// FIXME: The weights for catchpads will be wrong.
addSuccessorWithWeight(InvokeMBB, Return);
for (auto *UnwindDest : UnwindDests) {
for (MachineBasicBlock *UnwindDest : UnwindDests) {
UnwindDest->setIsEHPad();
if (!IsLandingPad)
UnwindDest->setIsEHFuncletEntry();
addSuccessorWithWeight(InvokeMBB, UnwindDest);
}

201
lib/CodeGen/WinEHPrepare.cpp
View File

@ -2616,7 +2616,6 @@ static void addTryBlockMapEntry(WinEHFuncInfo &FuncInfo, int TryLow,
cast<GlobalVariable>(CS->getAggregateElement(1)->stripPointerCasts());
}
HT.Handler = CPI->getNormalDest();
HT.HandlerMBB = nullptr;
// FIXME: Pass CPI->getArgOperand(1).
HT.CatchObjRecoverIdx = -1;
TBME.HandlerArray.push_back(HT);
@ -2645,7 +2644,8 @@ void WinEHNumbering::createTryBlockMapEntry(int TryLow, int TryHigh,
continue;
int N;
for (N = 0; N < NumHandlers; ++N) {
if (Entry.HandlerArray[N].Handler != Handlers[N]->getHandlerBlockOrFunc())
if (Entry.HandlerArray[N].Handler.get<const Value *>() !=
Handlers[N]->getHandlerBlockOrFunc())
break; // breaks out of inner loop
}
// If all the handlers match, this is what we were looking for.
@ -2692,7 +2692,6 @@ void WinEHNumbering::createTryBlockMapEntry(int TryLow, int TryHigh,
cast<GlobalVariable>(CS->getAggregateElement(1)->stripPointerCasts());
}
HT.Handler = cast<Function>(CH->getHandlerBlockOrFunc());
HT.HandlerMBB = nullptr;
HT.CatchObjRecoverIdx = CH->getExceptionVarIndex();
TBME.HandlerArray.push_back(HT);
}
@ -2949,13 +2948,45 @@ 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;
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
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) {
@ -2970,9 +3001,9 @@ static const BasicBlock *getEHPadFromPredecessor(const BasicBlock *BB) {
return cast<CleanupReturnInst>(TI)->getCleanupPad()->getParent();
}
static void calculateExplicitStateNumbers(WinEHFuncInfo &FuncInfo,
const BasicBlock &BB,
int ParentState) {
static void calculateExplicitCXXStateNumbers(WinEHFuncInfo &FuncInfo,
const BasicBlock &BB,
int ParentState) {
assert(BB.isEHPad());
const Instruction *FirstNonPHI = BB.getFirstNonPHI();
// All catchpad instructions will be handled when we process their
@ -2981,36 +3012,30 @@ static void calculateExplicitStateNumbers(WinEHFuncInfo &FuncInfo,
return;
if (isa<CatchEndPadInst>(FirstNonPHI)) {
const BasicBlock *TryPad = &BB;
const BasicBlock *LastTryPad = nullptr;
SmallVector<const CatchPadInst *, 2> Handlers;
do {
LastTryPad = TryPad;
TryPad = getSingleCatchPadPredecessor(*TryPad);
if (TryPad)
Handlers.push_back(cast<CatchPadInst>(TryPad->getFirstNonPHI()));
} while (TryPad);
// We've pushed these back into reverse source order. Reverse them to get
// the list back into source order.
std::reverse(Handlers.begin(), Handlers.end());
findCatchPadsForCatchEndPad(&BB, Handlers);
const BasicBlock *FirstTryPad = Handlers.front()->getParent();
int TryLow = addUnwindMapEntry(FuncInfo, ParentState, nullptr);
FuncInfo.EHPadStateMap[Handlers.front()] = TryLow;
for (const BasicBlock *PredBlock : predecessors(LastTryPad))
for (const BasicBlock *PredBlock : predecessors(FirstTryPad))
if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
calculateExplicitStateNumbers(FuncInfo, *PredBlock, TryLow);
calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, TryLow);
int CatchLow = addUnwindMapEntry(FuncInfo, ParentState, nullptr);
// catchpads are separate funclets in C++ EH due to the way rethrow works.
// In SEH, they aren't, so no invokes will unwind to the catchendpad.
FuncInfo.EHPadStateMap[FirstNonPHI] = CatchLow;
int TryHigh = CatchLow - 1;
for (const BasicBlock *PredBlock : predecessors(&BB))
if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
calculateExplicitStateNumbers(FuncInfo, *PredBlock, CatchLow);
calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, CatchLow);
int CatchHigh = FuncInfo.getLastStateNumber();
addTryBlockMapEntry(FuncInfo, TryLow, TryHigh, CatchHigh, Handlers);
DEBUG(dbgs() << "TryLow[" << LastTryPad->getName() << "]: " << TryLow
DEBUG(dbgs() << "TryLow[" << FirstTryPad->getName() << "]: " << TryLow
<< '\n');
DEBUG(dbgs() << "TryHigh[" << LastTryPad->getName() << "]: " << TryHigh
DEBUG(dbgs() << "TryHigh[" << FirstTryPad->getName() << "]: " << TryHigh
<< '\n');
DEBUG(dbgs() << "CatchHigh[" << LastTryPad->getName() << "]: " << CatchHigh
DEBUG(dbgs() << "CatchHigh[" << FirstTryPad->getName() << "]: " << CatchHigh
<< '\n');
} else if (isa<CleanupPadInst>(FirstNonPHI)) {
int CleanupState = addUnwindMapEntry(FuncInfo, ParentState, &BB);
@ -3019,7 +3044,7 @@ static void calculateExplicitStateNumbers(WinEHFuncInfo &FuncInfo,
<< BB.getName() << '\n');
for (const BasicBlock *PredBlock : predecessors(&BB))
if ((PredBlock = getEHPadFromPredecessor(PredBlock)))
calculateExplicitStateNumbers(FuncInfo, *PredBlock, CleanupState);
calculateExplicitCXXStateNumbers(FuncInfo, *PredBlock, CleanupState);
} else if (isa<TerminatePadInst>(FirstNonPHI)) {
report_fatal_error("Not yet implemented!");
} else {
@ -3027,6 +3052,103 @@ static void calculateExplicitStateNumbers(WinEHFuncInfo &FuncInfo,
}
}
static int addSEHHandler(WinEHFuncInfo &FuncInfo, int ParentState,
const Function *Filter, const BasicBlock *Handler) {
SEHUnwindMapEntry Entry;
Entry.ToState = ParentState;
Entry.Filter = Filter;
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 Function *Filter =
cast<Function>(CPI->getArgOperand(0)->stripPointerCasts());
int TryState =
addSEHHandler(FuncInfo, ParentState, Filter, CPI->getNormalDest());
// 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 =
addSEHHandler(FuncInfo, ParentState, /*Filter=*/nullptr, &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<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 *ParentFn,
WinEHFuncInfo &FuncInfo) {
// Don't compute state numbers twice.
if (!FuncInfo.SEHUnwindMap.empty())
return;
for (const BasicBlock &BB : *ParentFn) {
if (!BB.isEHPad() || !doesEHPadUnwindToCaller(BB.getFirstNonPHI()))
continue;
calculateExplicitSEHStateNumbers(FuncInfo, BB, -1);
}
}
void llvm::calculateWinCXXEHStateNumbers(const Function *ParentFn,
WinEHFuncInfo &FuncInfo) {
// Return if it's already been done.
@ -3041,28 +3163,9 @@ void llvm::calculateWinCXXEHStateNumbers(const Function *ParentFn,
// Skip cleanupendpads; they are exits, not entries.
if (isa<CleanupEndPadInst>(FirstNonPHI))
continue;
// Check if the EH Pad has no exceptional successors (i.e. it unwinds to
// caller). Cleanups are a little bit of a special case because their
// control flow cannot be determined by looking at the pad but instead by
// the pad's users.
bool HasNoSuccessors = false;
if (FirstNonPHI->mayThrow()) {
HasNoSuccessors = true;
} else if (auto *CPI = dyn_cast<CleanupPadInst>(FirstNonPHI)) {
if (CPI->use_empty()) {
HasNoSuccessors = true;
} else {
const Instruction *User = CPI->user_back();
if (auto *CRI = dyn_cast<CleanupReturnInst>(User))
HasNoSuccessors = CRI->unwindsToCaller();
else
HasNoSuccessors = cast<CleanupEndPadInst>(User)->unwindsToCaller();
}
}
if (!HasNoSuccessors)
if (!doesEHPadUnwindToCaller(FirstNonPHI))
continue;
calculateExplicitStateNumbers(FuncInfo, BB, -1);
calculateExplicitCXXStateNumbers(FuncInfo, BB, -1);
IsExplicit = true;
}

10
lib/Target/X86/X86ISelLowering.cpp
View File

@ -16880,6 +16880,16 @@ SDValue X86TargetLowering::LowerCATCHRET(SDValue Op, SelectionDAG &DAG) const {
SDLoc DL(Op);
MVT PtrVT = getPointerTy(DAG.getDataLayout());
MachineFunction &MF = DAG.getMachineFunction();
if (isAsynchronousEHPersonality(
classifyEHPersonality(MF.getFunction()->getPersonalityFn()))) {
// For SEH, codegen catchret as a branch for now.
// FIXME: Insert something to restore the frame.
return DAG.getNode(ISD::BR, DL, MVT::Other, Chain, Dest);
}
unsigned ReturnReg = (PtrVT == MVT::i64 ? X86::RAX : X86::EAX);
// Load the address of the destination block.

63
lib/Target/X86/X86WinEHState.cpp
View File

@ -68,9 +68,10 @@ private:
void unlinkExceptionRegistration(IRBuilder<> &Builder);
void addCXXStateStores(Function &F, WinEHFuncInfo &FuncInfo);
void addSEHStateStores(Function &F, WinEHFuncInfo &FuncInfo);
void addCXXStateStoresToFunclet(Value *ParentRegNode, WinEHFuncInfo &FuncInfo,
Function &F, int BaseState);
void addStateStoresToFunclet(Value *ParentRegNode, WinEHFuncInfo &FuncInfo,
Function &F, int BaseState);
void insertStateNumberStore(Value *ParentRegNode, Instruction *IP, int State);
void insertRestoreFrame(BasicBlock *BB);
Value *emitEHLSDA(IRBuilder<> &Builder, Function *F);
@ -91,6 +92,7 @@ private:
Function *FrameRecover = nullptr;
Function *FrameAddress = nullptr;
Function *FrameEscape = nullptr;
Function *RestoreFrame = nullptr;
// Per-function state
EHPersonality Personality = EHPersonality::Unknown;
@ -123,6 +125,8 @@ bool WinEHStatePass::doInitialization(Module &M) {
FrameEscape = Intrinsic::getDeclaration(TheModule, Intrinsic::localescape);
FrameRecover = Intrinsic::getDeclaration(TheModule, Intrinsic::localrecover);
FrameAddress = Intrinsic::getDeclaration(TheModule, Intrinsic::frameaddress);
RestoreFrame =
Intrinsic::getDeclaration(TheModule, Intrinsic::x86_seh_restoreframe);
return false;
}
@ -414,7 +418,7 @@ void WinEHStatePass::addCXXStateStores(Function &F, WinEHFuncInfo &FuncInfo) {
calculateWinCXXEHStateNumbers(&F, FuncInfo);
// The base state for the parent is -1.
addCXXStateStoresToFunclet(RegNode, FuncInfo, F, -1);
addStateStoresToFunclet(RegNode, FuncInfo, F, -1);
// Set up RegNodeEscapeIndex
int RegNodeEscapeIndex = escapeRegNode(F);
@ -434,7 +438,7 @@ void WinEHStatePass::addCXXStateStores(Function &F, WinEHFuncInfo &FuncInfo) {
FrameRecover, {FI8, ParentFP, Builder.getInt32(RegNodeEscapeIndex)});
RecoveredRegNode =
Builder.CreateBitCast(RecoveredRegNode, RegNodeTy->getPointerTo(0));
addCXXStateStoresToFunclet(RecoveredRegNode, FuncInfo, *Handler, BaseState);
addStateStoresToFunclet(RecoveredRegNode, FuncInfo, *Handler, BaseState);
}
}
@ -470,11 +474,17 @@ int WinEHStatePass::escapeRegNode(Function &F) {
return Args.size() - 1;
}
void WinEHStatePass::addCXXStateStoresToFunclet(Value *ParentRegNode,
WinEHFuncInfo &FuncInfo,
Function &F, int BaseState) {
Function *RestoreFrame =
Intrinsic::getDeclaration(TheModule, Intrinsic::x86_seh_restoreframe);
void WinEHStatePass::insertRestoreFrame(BasicBlock *BB) {
Instruction *Start = BB->getFirstInsertionPt();
if (match(Start, m_Intrinsic<Intrinsic::x86_seh_restoreframe>()))
return;
IRBuilder<> Builder(Start);
Builder.CreateCall(RestoreFrame, {});
}
void WinEHStatePass::addStateStoresToFunclet(Value *ParentRegNode,
WinEHFuncInfo &FuncInfo,
Function &F, int BaseState) {
// Iterate all the instructions and emit state number stores.
for (BasicBlock &BB : F) {
for (Instruction &I : BB) {
@ -494,16 +504,14 @@ void WinEHStatePass::addCXXStateStoresToFunclet(Value *ParentRegNode,
}
}
// Insert calls to llvm.x86.seh.restoreframe at catchret destinations.
if (auto *CR = dyn_cast<CatchReturnInst>(BB.getTerminator())) {
Instruction *Start = CR->getSuccessor()->begin();
assert(!isa<PHINode>(Start) &&
"winehprepare failed to demote phi after catchret");
if (match(Start, m_Intrinsic<Intrinsic::x86_seh_restoreframe>()))
continue;
IRBuilder<> Builder(Start);
Builder.CreateCall(RestoreFrame, {});
}
// Insert calls to llvm.x86.seh.restoreframe at catchret destinations. In
// SEH, insert them before the catchret.
// FIXME: We should probably do this as part of catchret lowering in the
// DAG.
if (auto *CR = dyn_cast<CatchReturnInst>(BB.getTerminator()))
insertRestoreFrame(Personality == EHPersonality::MSVC_X86SEH
? CR->getParent()
: CR->getSuccessor());
}
}
@ -519,6 +527,23 @@ void WinEHStatePass::addSEHStateStores(Function &F, WinEHFuncInfo &FuncInfo) {
int RegNodeEscapeIndex = escapeRegNode(F);
FuncInfo.EHRegNodeEscapeIndex = RegNodeEscapeIndex;
// If this funciton uses the new EH IR, use the explicit state numbering
// algorithm and return early.
bool UsesLPads = false;
for (BasicBlock &BB : F) {
if (BB.isLandingPad()) {
UsesLPads = true;
break;
}
}
if (!UsesLPads) {
calculateSEHStateNumbers(&F, FuncInfo);
addStateStoresToFunclet(RegNode, FuncInfo, F, -1);
return;
}
// FIXME: Delete the rest of this code and clean things up when new EH is
// done.
// Iterate all the instructions and emit state number stores.
int CurState = 0;
SmallPtrSet<BasicBlock *, 4> ExceptBlocks;

219
test/CodeGen/X86/win32-seh-catchpad.ll Normal file
View File

@ -0,0 +1,219 @@
; RUN: llc < %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"
define void @try_except() #0 personality i8* bitcast (i32 (...)* @_except_handler3 to i8*) {
entry:
%__exception_code = alloca i32, align 4
call void (...) @llvm.localescape(i32* %__exception_code)
invoke void @f(i32 1) #3
to label %invoke.cont unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchpad [i8* bitcast (i32 ()* @try_except_filter_catchall to i8*)] to label %__except.ret unwind label %catchendblock
__except.ret: ; preds = %catch.dispatch
catchret %0 to label %__except
__except: ; preds = %__except.ret
call void @f(i32 2)
br label %__try.cont
__try.cont: ; preds = %__except, %invoke.cont
call void @f(i32 3)
ret void
catchendblock: ; preds = %catch.dispatch
catchendpad unwind to caller
invoke.cont: ; preds = %entry
br label %__try.cont
}
; CHECK-LABEL: _try_except:
; Store state #0
; CHECK: movl $0, -[[state:[0-9]+]](%ebp)
; CHECK: movl $1, (%esp)
; CHECK: calll _f
; CHECK: movl $-1, -[[state]](%ebp)
; CHECK: movl $3, (%esp)
; CHECK: calll _f
; CHECK: retl
; __except
; CHECK: movl $-1, -[[state]](%ebp)
; CHECK: movl $2, (%esp)
; CHECK: calll _f
; CHECK: .section .xdata,"dr"
; CHECK: L__ehtable$try_except:
; CHECK: .long -1
; CHECK: .long _try_except_filter_catchall
; CHECK: .long LBB0_1
define internal i32 @try_except_filter_catchall() #0 {
entry:
%0 = call i8* @llvm.frameaddress(i32 1)
%1 = call i8* @llvm.x86.seh.recoverfp(i8* bitcast (void ()* @try_except to i8*), i8* %0)
%2 = call i8* @llvm.localrecover(i8* bitcast (void ()* @try_except to i8*), i8* %1, i32 0)
%__exception_code = bitcast i8* %2 to i32*
%3 = getelementptr inbounds i8, i8* %0, i32 -20
%4 = bitcast i8* %3 to i8**
%5 = load i8*, i8** %4, align 4
%6 = bitcast i8* %5 to { i32*, i8* }*
%7 = getelementptr inbounds { i32*, i8* }, { i32*, i8* }* %6, i32 0, i32 0
%8 = load i32*, i32** %7, align 4
%9 = load i32, i32* %8, align 4
store i32 %9, i32* %__exception_code, align 4
ret i32 1
}
define void @nested_exceptions() #0 personality i8* bitcast (i32 (...)* @_except_handler3 to i8*) {
entry:
%__exception_code = alloca i32, align 4
call void (...) @llvm.localescape(i32* %__exception_code)
invoke void @crash() #3
to label %__try.cont unwind label %catch.dispatch
catch.dispatch: ; preds = %entry
%0 = catchpad [i8* bitcast (i32 ()* @nested_exceptions_filter_catchall to i8*)] to label %__except.ret unwind label %catchendblock
__except.ret: ; preds = %catch.dispatch
catchret %0 to label %__try.cont
__try.cont: ; preds = %entry, %__except.ret
invoke void @crash() #3
to label %__try.cont.9 unwind label %catch.dispatch.5
catch.dispatch.5: ; preds = %__try.cont
%1 = catchpad [i8* bitcast (i32 ()* @nested_exceptions_filter_catchall to i8*)] to label %__except.ret.7 unwind label %catchendblock.6
__except.ret.7: ; preds = %catch.dispatch.5
catchret %1 to label %__try.cont.9
__try.cont.9: ; preds = %__try.cont, %__except.ret.7
invoke void @crash() #3
to label %__try.cont.15 unwind label %catch.dispatch.11
catch.dispatch.11: ; preds = %catchendblock, %catchendblock.6, %__try.cont.9
%2 = catchpad [i8* bitcast (i32 ()* @nested_exceptions_filter_catchall to i8*)] to label %__except.ret.13 unwind label %catchendblock.12
__except.ret.13: ; preds = %catch.dispatch.11
catchret %2 to label %__try.cont.15
__try.cont.15: ; preds = %__try.cont.9, %__except.ret.13
invoke void @crash() #3
to label %__try.cont.35 unwind label %catch.dispatch.17
catch.dispatch.17: ; preds = %catchendblock.12, %__try.cont.15
%3 = catchpad [i8* bitcast (i32 ()* @nested_exceptions_filter_catchall to i8*)] to label %__except.ret.19 unwind label %catchendblock.18
__except.ret.19: ; preds = %catch.dispatch.17
catchret %3 to label %__except.20
__except.20: ; preds = %__except.ret.19
invoke void @crash() #3
to label %__try.cont.27 unwind label %catch.dispatch.23
catch.dispatch.23: ; preds = %__except.20
%4 = catchpad [i8* bitcast (i32 ()* @nested_exceptions_filter_catchall to i8*)] to label %__except.ret.25 unwind label %catchendblock.24
__except.ret.25: ; preds = %catch.dispatch.23
catchret %4 to label %__try.cont.27
__try.cont.27: ; preds = %__except.20, %__except.ret.25
invoke void @crash() #3
to label %__try.cont.35 unwind label %catch.dispatch.30
catch.dispatch.30: ; preds = %__try.cont.27
%5 = catchpad [i8* bitcast (i32 ()* @nested_exceptions_filter_catchall to i8*)] to label %__except.ret.32 unwind label %catchendblock.31
__except.ret.32: ; preds = %catch.dispatch.30
catchret %5 to label %__try.cont.35
__try.cont.35: ; preds = %__try.cont.15, %__try.cont.27, %__except.ret.32
ret void
catchendblock.31: ; preds = %catch.dispatch.30
catchendpad unwind to caller
catchendblock.24: ; preds = %catch.dispatch.23
catchendpad unwind to caller
catchendblock.18: ; preds = %catch.dispatch.17
catchendpad unwind to caller
catchendblock.12: ; preds = %catch.dispatch.11
catchendpad unwind label %catch.dispatch.17
catchendblock.6: ; preds = %catch.dispatch.5
catchendpad unwind label %catch.dispatch.11
catchendblock: ; preds = %catch.dispatch
catchendpad unwind label %catch.dispatch.11
}
; This table is equivalent to the one produced by MSVC, even if it isn't in
; quite the same order.
; CHECK-LABEL: _nested_exceptions:
; CHECK: L__ehtable$nested_exceptions:
; CHECK: .long -1
; CHECK: .long _nested_exceptions_filter_catchall
; CHECK: .long LBB
; CHECK: .long -1
; CHECK: .long _nested_exceptions_filter_catchall
; CHECK: .long LBB
; CHECK: .long -1
; CHECK: .long _nested_exceptions_filter_catchall
; CHECK: .long LBB
; CHECK: .long 2
; CHECK: .long _nested_exceptions_filter_catchall
; CHECK: .long LBB
; CHECK: .long 3
; CHECK: .long _nested_exceptions_filter_catchall
; CHECK: .long LBB
; CHECK: .long 3
; CHECK: .long _nested_exceptions_filter_catchall
; CHECK: .long LBB
declare void @crash() #0
define internal i32 @nested_exceptions_filter_catchall() #0 {
entry:
%0 = call i8* @llvm.frameaddress(i32 1)
%1 = call i8* @llvm.x86.seh.recoverfp(i8* bitcast (void ()* @nested_exceptions to i8*), i8* %0)
%2 = call i8* @llvm.localrecover(i8* bitcast (void ()* @nested_exceptions to i8*), i8* %1, i32 0)
%__exception_code3 = bitcast i8* %2 to i32*
%3 = getelementptr inbounds i8, i8* %0, i32 -20
%4 = bitcast i8* %3 to i8**
%5 = load i8*, i8** %4, align 4
%6 = bitcast i8* %5 to { i32*, i8* }*
%7 = getelementptr inbounds { i32*, i8* }, { i32*, i8* }* %6, i32 0, i32 0
%8 = load i32*, i32** %7, align 4
%9 = load i32, i32* %8, align 4
store i32 %9, i32* %__exception_code3, align 4
ret i32 1
}
; Function Attrs: nounwind readnone
declare i8* @llvm.frameaddress(i32) #1
; Function Attrs: nounwind readnone
declare i8* @llvm.x86.seh.recoverfp(i8*, i8*) #1
; Function Attrs: nounwind readnone
declare i8* @llvm.localrecover(i8*, i8*, i32) #1
declare void @f(i32) #0
declare i32 @_except_handler3(...)
; Function Attrs: nounwind
declare void @llvm.localescape(...) #2
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 = { nounwind readnone }
attributes #2 = { nounwind }
attributes #3 = { noinline }