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There are some situations which can cause the URoR hack to infinitely recurse

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and then go kablooie. The problem was that it was tracking the PHI nodes anew
each time into this function. But it didn't need to. And because the recursion
didn't know that a PHINode was visited before, it would go ahead and call
itself.

There is a testcase, but unfortunately it's too big to add. This problem will go
away with the EH rewrite.
<rdar://problem/8856298>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127640 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling 2011-03-15 01:03:17 +00:00
parent c343c1e27e
commit 28cc1aa3a7
1 changed files with 8 additions and 6 deletions
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14
lib/CodeGen/DwarfEHPrepare.cpp
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@ -93,7 +93,8 @@ namespace {
/// with the eh.exception call. This recursively looks past instructions
/// which don't change the EH pointer value, like casts or PHI nodes.
bool FindSelectorAndURoR(Instruction *Inst, bool &URoRInvoke,
SmallPtrSet<IntrinsicInst*, 8> &SelCalls);
SmallPtrSet<IntrinsicInst*, 8> &SelCalls,
SmallPtrSet<PHINode*, 32> &SeenPHIs);
public:
static char ID; // Pass identification, replacement for typeid.
@ -199,8 +200,8 @@ bool DwarfEHPrepare::CleanupSelectors(SmallPtrSet<IntrinsicInst*, 32> &Sels) {
/// change the EH pointer value, like casts or PHI nodes.
bool
DwarfEHPrepare::FindSelectorAndURoR(Instruction *Inst, bool &URoRInvoke,
SmallPtrSet<IntrinsicInst*, 8> &SelCalls) {
SmallPtrSet<PHINode*, 32> SeenPHIs;
SmallPtrSet<IntrinsicInst*, 8> &SelCalls,
SmallPtrSet<PHINode*, 32> &SeenPHIs) {
bool Changed = false;
for (Value::use_iterator
@ -215,11 +216,11 @@ DwarfEHPrepare::FindSelectorAndURoR(Instruction *Inst, bool &URoRInvoke,
if (Invoke->getCalledFunction() == URoR)
URoRInvoke = true;
} else if (CastInst *CI = dyn_cast<CastInst>(II)) {
Changed |= FindSelectorAndURoR(CI, URoRInvoke, SelCalls);
Changed |= FindSelectorAndURoR(CI, URoRInvoke, SelCalls, SeenPHIs);
} else if (PHINode *PN = dyn_cast<PHINode>(II)) {
if (SeenPHIs.insert(PN))
// Don't process a PHI node more than once.
Changed |= FindSelectorAndURoR(PN, URoRInvoke, SelCalls);
Changed |= FindSelectorAndURoR(PN, URoRInvoke, SelCalls, SeenPHIs);
}
}
@ -294,7 +295,8 @@ bool DwarfEHPrepare::HandleURoRInvokes() {
bool URoRInvoke = false;
SmallPtrSet<IntrinsicInst*, 8> SelCalls;
Changed |= FindSelectorAndURoR(EHPtr, URoRInvoke, SelCalls);
SmallPtrSet<PHINode*, 32> SeenPHIs;
Changed |= FindSelectorAndURoR(EHPtr, URoRInvoke, SelCalls, SeenPHIs);
if (URoRInvoke) {
// This EH pointer is being used by an invoke of an URoR instruction and