Workaround for PR1508.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37597 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan Sands 2007-06-15 19:04:19 +00:00
parent e19dd87598
commit f40708223e
3 changed files with 101 additions and 30 deletions

View File

@ -179,6 +179,11 @@ namespace llvm {
/// anywhere in the function.
std::map<const AllocaInst*, int> StaticAllocaMap;
#ifndef NDEBUG
SmallSet<Instruction*, 8> CatchInfoLost;
SmallSet<Instruction*, 8> CatchInfoFound;
#endif
unsigned MakeReg(MVT::ValueType VT) {
return RegMap->createVirtualRegister(TLI.getRegClassFor(VT));
}
@ -199,6 +204,15 @@ namespace llvm {
};
}
/// isFilterOrSelector - Return true if this instruction is a call to the
/// eh.filter or the eh.selector intrinsic.
static bool isFilterOrSelector(Instruction *I) {
if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I))
return II->getIntrinsicID() == Intrinsic::eh_selector
|| II->getIntrinsicID() == Intrinsic::eh_filter;
return false;
}
/// isUsedOutsideOfDefiningBlock - Return true if this instruction is used by
/// PHI nodes or outside of the basic block that defines it, or used by a
/// switch instruction, which may expand to multiple basic blocks.
@ -2463,6 +2477,33 @@ static GlobalVariable *ExtractGlobalVariable (Constant *C) {
return NULL;
}
/// addCatchInfo - Extract the personality and type infos from an eh.selector
/// or eh.filter call, and add them to the specified machine basic block.
static void addCatchInfo(CallInst &I, MachineModuleInfo *MMI,
MachineBasicBlock *MBB) {
// Inform the MachineModuleInfo of the personality for this landing pad.
ConstantExpr *CE = cast<ConstantExpr>(I.getOperand(2));
assert(CE->getOpcode() == Instruction::BitCast &&
isa<Function>(CE->getOperand(0)) &&
"Personality should be a function");
MMI->addPersonality(MBB, cast<Function>(CE->getOperand(0)));
// Gather all the type infos for this landing pad and pass them along to
// MachineModuleInfo.
std::vector<GlobalVariable *> TyInfo;
for (unsigned i = 3, N = I.getNumOperands(); i < N; ++i) {
Constant *C = cast<Constant>(I.getOperand(i));
GlobalVariable *GV = ExtractGlobalVariable(C);
assert (GV || isa<ConstantPointerNull>(C) &&
"TypeInfo must be a global variable or NULL");
TyInfo.push_back(GV);
}
if (I.getCalledFunction()->getIntrinsicID() == Intrinsic::eh_filter)
MMI->addFilterTypeInfo(MBB, TyInfo);
else
MMI->addCatchTypeInfo(MBB, TyInfo);
}
/// visitIntrinsicCall - Lower the call to the specified intrinsic function. If
/// we want to emit this as a call to a named external function, return the name
/// otherwise lower it and return null.
@ -2597,27 +2638,12 @@ SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
MachineModuleInfo *MMI = DAG.getMachineModuleInfo();
if (ExceptionHandling && MMI) {
// Inform the MachineModuleInfo of the personality for this landing pad.
ConstantExpr *CE = dyn_cast<ConstantExpr>(I.getOperand(2));
assert(CE && CE->getOpcode() == Instruction::BitCast &&
isa<Function>(CE->getOperand(0)) &&
"Personality should be a function");
MMI->addPersonality(CurMBB, cast<Function>(CE->getOperand(0)));
// Gather all the type infos for this landing pad and pass them along to
// MachineModuleInfo.
std::vector<GlobalVariable *> TyInfo;
for (unsigned i = 3, N = I.getNumOperands(); i < N; ++i) {
Constant *C = cast<Constant>(I.getOperand(i));
GlobalVariable *GV = ExtractGlobalVariable(C);
assert (GV || isa<ConstantPointerNull>(C) &&
"TypeInfo must be a global variable or NULL");
TyInfo.push_back(GV);
}
if (Intrinsic == Intrinsic::eh_filter)
MMI->addFilterTypeInfo(CurMBB, TyInfo);
if (CurMBB->isLandingPad())
addCatchInfo(I, MMI, CurMBB);
#ifndef NDEBUG
else
MMI->addCatchTypeInfo(CurMBB, TyInfo);
FuncInfo.CatchInfoLost.insert(&I);
#endif
// Mark exception selector register as live in.
unsigned Reg = TLI.getExceptionSelectorRegister();
@ -4403,6 +4429,11 @@ bool SelectionDAGISel::runOnFunction(Function &Fn) {
E = MF.livein_end(); I != E; ++I)
BB->addLiveIn(I->first);
#ifndef NDEBUG
assert(FuncInfo.CatchInfoFound.size() == FuncInfo.CatchInfoLost.size() &&
"Not all catch info was assigned to a landing pad!");
#endif
return true;
}
@ -4513,6 +4544,20 @@ LowerArguments(BasicBlock *LLVMBB, SelectionDAGLowering &SDL,
EmitFunctionEntryCode(F, SDL.DAG.getMachineFunction());
}
static void copyCatchInfo(BasicBlock *SrcBB, BasicBlock *DestBB,
MachineModuleInfo *MMI, FunctionLoweringInfo &FLI) {
assert(!FLI.MBBMap[SrcBB]->isLandingPad() &&
"Copying catch info out of a landing pad!");
for (BasicBlock::iterator I = SrcBB->begin(), E = --SrcBB->end(); I != E; ++I)
if (isFilterOrSelector(I)) {
// Apply the catch info to DestBB.
addCatchInfo(cast<CallInst>(*I), MMI, FLI.MBBMap[DestBB]);
#ifndef NDEBUG
FLI.CatchInfoFound.insert(I);
#endif
}
}
void SelectionDAGISel::BuildSelectionDAG(SelectionDAG &DAG, BasicBlock *LLVMBB,
std::vector<std::pair<MachineInstr*, unsigned> > &PHINodesToUpdate,
FunctionLoweringInfo &FuncInfo) {
@ -4527,15 +4572,37 @@ void SelectionDAGISel::BuildSelectionDAG(SelectionDAG &DAG, BasicBlock *LLVMBB,
BB = FuncInfo.MBBMap[LLVMBB];
SDL.setCurrentBasicBlock(BB);
if (ExceptionHandling && BB->isLandingPad()) {
MachineModuleInfo *MMI = DAG.getMachineModuleInfo();
MachineModuleInfo *MMI = DAG.getMachineModuleInfo();
if (MMI) {
// Add a label to mark the beginning of the landing pad. Deletion of the
// landing pad can thus be detected via the MachineModuleInfo.
unsigned LabelID = MMI->addLandingPad(BB);
DAG.setRoot(DAG.getNode(ISD::LABEL, MVT::Other, DAG.getEntryNode(),
DAG.getConstant(LabelID, MVT::i32)));
if (ExceptionHandling && MMI && BB->isLandingPad()) {
// Add a label to mark the beginning of the landing pad. Deletion of the
// landing pad can thus be detected via the MachineModuleInfo.
unsigned LabelID = MMI->addLandingPad(BB);
DAG.setRoot(DAG.getNode(ISD::LABEL, MVT::Other, DAG.getEntryNode(),
DAG.getConstant(LabelID, MVT::i32)));
// FIXME: Hack around an exception handling flaw (PR1508): the personality
// function and list of typeids logically belong to the invoke (or, if you
// like, the basic block containing the invoke), and need to be associated
// with it in the dwarf exception handling tables. Currently however the
// information is provided by intrinsics (eh.filter and eh.selector) that
// can be moved to unexpected places by the optimizers: if the unwind edge
// is critical, then breaking it can result in the intrinsics being in the
// successor of the landing pad, not the landing pad itself. This results
// in exceptions not being caught because no typeids are associated with
// the invoke. This may not be the only way things can go wrong, but it
// is the only way we try to work around for the moment.
BranchInst *Br = dyn_cast<BranchInst>(LLVMBB->getTerminator());
if (Br && Br->isUnconditional()) { // Critical edge?
BasicBlock::iterator I, E;
for (I = LLVMBB->begin(), E = --LLVMBB->end(); I != E; ++I)
if (isFilterOrSelector(I))
break;
if (I == E)
// No catch info found - try to extract some from the successor.
copyCatchInfo(Br->getSuccessor(0), LLVMBB, MMI, FuncInfo);
}
}

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@ -1,5 +1,7 @@
; RUN: llvm-as < %s | llc -enable-eh
; RUN: llvm-as < %s | llc -enable-eh -march=x86-64
; XFAIL: *
; Un-XFAIL this when PR1508 is fixed.
; PR1326

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@ -1,5 +1,7 @@
; RUN: llvm-as < %s | llc -enable-eh -asm-verbose -o - | grep {Llabel137.*Region start}
; RUN: llvm-as < %s | llc -enable-eh -asm-verbose -o - | \
; RUN: grep -A 3 {Llabel137.*Region start} | grep {5.*Action}
; PR1422
; PR1508
target triple = "i686-pc-linux-gnu"
%struct.exception = type { i8, i8, i32, i8*, i8*, i32, i8* }