Revert "Revert r234581, it might have caused a few miscompiles in Chromium."
This reverts commit r234700. It turns out that the lifetime markers
were not the cause of Chromium failing but a bug which was uncovered by
optimizations exposed by the markers.
llvm-svn: 235553
diff --git a/clang/lib/CodeGen/CGCleanup.cpp b/clang/lib/CodeGen/CGCleanup.cpp
index 299969a..d97e405 100644
--- a/clang/lib/CodeGen/CGCleanup.cpp
+++ b/clang/lib/CodeGen/CGCleanup.cpp
@@ -125,6 +125,17 @@
return StartOfData;
}
+bool EHScopeStack::containsOnlyLifetimeMarkers(
+ EHScopeStack::stable_iterator Old) const {
+ for (EHScopeStack::iterator it = begin(); stabilize(it) != Old; it++) {
+ EHCleanupScope *cleanup = dyn_cast<EHCleanupScope>(&*it);
+ if (!cleanup || !cleanup->isLifetimeMarker())
+ return false;
+ }
+
+ return true;
+}
+
EHScopeStack::stable_iterator
EHScopeStack::getInnermostActiveNormalCleanup() const {
for (stable_iterator si = getInnermostNormalCleanup(), se = stable_end();
@@ -748,7 +759,15 @@
Scope.getNumBranchAfters() == 1) {
assert(!BranchThroughDest || !IsActive);
- // TODO: clean up the possibly dead stores to the cleanup dest slot.
+ // Clean up the possibly dead store to the cleanup dest slot.
+ llvm::Instruction *NormalCleanupDestSlot =
+ cast<llvm::Instruction>(getNormalCleanupDestSlot());
+ if (NormalCleanupDestSlot->hasOneUse()) {
+ NormalCleanupDestSlot->user_back()->eraseFromParent();
+ NormalCleanupDestSlot->eraseFromParent();
+ NormalCleanupDest = nullptr;
+ }
+
llvm::BasicBlock *BranchAfter = Scope.getBranchAfterBlock(0);
InstsToAppend.push_back(llvm::BranchInst::Create(BranchAfter));