[asan] make sure asan erases old unused allocas after it created a new one. This became important after the recent move from ModulePass to FunctionPass because no cleanup is happening after asan pass any more.

llvm-svn: 166267

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 75f42f30fab..d99bb87fd4c 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -1148,6 +1148,10 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) {
     }
   }
 
+  // We are done. Remove the old unused alloca instructions.
+  for (size_t i = 0, n = AllocaVec.size(); i < n; i++)
+    AllocaVec[i]->eraseFromParent();
+
   if (ClDebugStack) {
     DEBUG(dbgs() << F);
   }