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[ObjCARC] Turn off ignoring unwind edges in ObjCARC when -fno-objc-arc-exception is enabled due to it's affect on correctness.

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Specifically according to the semantics of ARC -fno-objc-arc-exception simply
states that it is expected that the unwind path out of a call *MAY* not release
objects. Thus we can have the situation where a release gets moved into a catch
block which we ignore when we remove a retain/release pair resulting in (even
though we assume the program is exiting anyways) the cleanup code path
potentially blowing up before program exit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172599 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Michael Gottesman 2013-01-16 06:32:39 +00:00
parent 457ee1a12e
commit 09c84f13c6
1 changed files with 0 additions and 33 deletions
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33
lib/Transforms/Scalar/ObjCARC.cpp
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@ -2675,17 +2675,6 @@ ObjCARCOpt::CheckForCFGHazards(const BasicBlock *BB,
PtrState &S = I->second;
succ_const_iterator SI(TI), SE(TI, false);
// If the terminator is an invoke marked with the
// clang.arc.no_objc_arc_exceptions metadata, the unwind edge can be
// ignored, for ARC purposes.
if (isa<InvokeInst>(TI) && TI->getMetadata(NoObjCARCExceptionsMDKind)) {
DEBUG(dbgs() << "ObjCARCOpt::CheckForCFGHazards: Found an invoke "
"terminator marked with "
"clang.arc.no_objc_arc_exceptions. Ignoring unwind "
"edge.\n");
--SE;
}
for (; SI != SE; ++SI) {
Sequence SuccSSeq = S_None;
bool SuccSRRIKnownSafe = false;
@ -2734,17 +2723,6 @@ ObjCARCOpt::CheckForCFGHazards(const BasicBlock *BB,
PtrState &S = I->second;
succ_const_iterator SI(TI), SE(TI, false);
// If the terminator is an invoke marked with the
// clang.arc.no_objc_arc_exceptions metadata, the unwind edge can be
// ignored, for ARC purposes.
if (isa<InvokeInst>(TI) && TI->getMetadata(NoObjCARCExceptionsMDKind)) {
DEBUG(dbgs() << "ObjCARCOpt::CheckForCFGHazards: Found an invoke "
"terminator marked with "
"clang.arc.no_objc_arc_exceptions. Ignoring unwind "
"edge.\n");
--SE;
}
for (; SI != SE; ++SI) {
Sequence SuccSSeq = S_None;
bool SuccSRRIKnownSafe = false;
@ -3199,17 +3177,6 @@ ComputePostOrders(Function &F,
TerminatorInst *TI = cast<TerminatorInst>(&CurrBB->back());
succ_iterator SE(TI, false);
// If the terminator is an invoke marked with the
// clang.arc.no_objc_arc_exceptions metadata, the unwind edge can be
// ignored, for ARC purposes.
if (isa<InvokeInst>(TI) && TI->getMetadata(NoObjCARCExceptionsMDKind)) {
DEBUG(dbgs() << "ObjCARCOpt::ComputePostOrders: Found an invoke "
"terminator marked with "
"clang.arc.no_objc_arc_exceptions. Ignoring unwind "
"edge.\n");
--SE;
}
while (SuccStack.back().second != SE) {
BasicBlock *SuccBB = *SuccStack.back().second++;
if (Visited.insert(SuccBB)) {