Fix a subtle bug with cleanups: when activating
a previously-inactive cleanup, not only do we need a
flag variable, but we should also force the cleanup to
query the flag variable. However, we only need to do
this when we're activating in a context that's
conditionally executed; otherwise, we may safely
assume that the cleanup is dominated by the activation
point.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@144271 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGCleanup.cpp b/lib/CodeGen/CGCleanup.cpp
index b2d0786..9e079c6 100644
--- a/lib/CodeGen/CGCleanup.cpp
+++ b/lib/CodeGen/CGCleanup.cpp
@@ -1003,27 +1003,32 @@
ForActivation_t Kind) {
EHCleanupScope &Scope = cast<EHCleanupScope>(*CGF.EHStack.find(C));
- // We always need the flag if we're activating the cleanup, because
- // we have to assume that the current location doesn't necessarily
- // dominate all future uses of the cleanup.
- bool NeedFlag = (Kind == ForActivation);
+ // We always need the flag if we're activating the cleanup in a
+ // conditional context, because we have to assume that the current
+ // location doesn't necessarily dominate the cleanup's code.
+ bool isActivatedInConditional =
+ (Kind == ForActivation && CGF.isInConditionalBranch());
+
+ bool needFlag = false;
// Calculate whether the cleanup was used:
// - as a normal cleanup
- if (Scope.isNormalCleanup() && IsUsedAsNormalCleanup(CGF.EHStack, C)) {
+ if (Scope.isNormalCleanup() &&
+ (isActivatedInConditional || IsUsedAsNormalCleanup(CGF.EHStack, C))) {
Scope.setTestFlagInNormalCleanup();
- NeedFlag = true;
+ needFlag = true;
}
// - as an EH cleanup
- if (Scope.isEHCleanup() && IsUsedAsEHCleanup(CGF.EHStack, C)) {
+ if (Scope.isEHCleanup() &&
+ (isActivatedInConditional || IsUsedAsEHCleanup(CGF.EHStack, C))) {
Scope.setTestFlagInEHCleanup();
- NeedFlag = true;
+ needFlag = true;
}
// If it hasn't yet been used as either, we're done.
- if (!NeedFlag) return;
+ if (!needFlag) return;
llvm::AllocaInst *Var = Scope.getActiveFlag();
if (!Var) {