ScalarEvolution: added tmp to avoid use-after-dtor in for loop.

Summary:
For loop destroyed current instance before invoking next.
Temporary variable added to prevent use-after-dtor when invoke
destructor on current instance.

Reviewers: eugenis

Subscribers: llvm-commits, sanjoy

Differential Revision: http://reviews.llvm.org/D12912

Rename temp var.

llvm-svn: 247867

1 files changed, 5 insertions, 2 deletions

diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index d8d94c422d2..3bdbee3e52c 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -8394,8 +8394,11 @@ ScalarEvolution::ScalarEvolution(ScalarEvolution &&Arg)
 ScalarEvolution::~ScalarEvolution() {
   // Iterate through all the SCEVUnknown instances and call their
   // destructors, so that they release their references to their values.
-  for (SCEVUnknown *U = FirstUnknown; U; U = U->Next)
-    U->~SCEVUnknown();
+  for (SCEVUnknown *U = FirstUnknown; U;) {
+    SCEVUnknown *Tmp = U;
+    U = U->Next;
+    Tmp->~SCEVUnknown();
+  }
   FirstUnknown = nullptr;
 
   ValueExprMap.clear();