From: Dan Gohman <gohman@apple.com>
Date: Fri, 29 Oct 2010 20:16:10 +0000 (+0000)
Subject: Make ScalarEvolution::forgetLoop forget all contained loops too, because
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e60dcb5e974989998f1d008ea2a1caee29665d58;p=oota-llvm.git

Make ScalarEvolution::forgetLoop forget all contained loops too, because
they may have ValuesAtScopes map entries referencing their outer loops.
This fixes a user-after-free reported in PR8471.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117698 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 5ae273e56d2..4d750b4464b 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -3781,6 +3781,11 @@ void ScalarEvolution::forgetLoop(const Loop *L) {
 
     PushDefUseChildren(I, Worklist);
   }
+
+  // Forget all contained loops too, to avoid dangling entries in the
+  // ValuesAtScopes map.
+  for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I)
+    forgetLoop(*I);
 }
 
 /// forgetValue - This method should be called by the client when it has