From 540c009fbe9567c008e0bfbcdb0f4f0f5b3a07f7 Mon Sep 17 00:00:00 2001
From: Zhongxing Xu <xuzhongxing@gmail.com>
Date: Sun, 21 Jun 2009 13:24:24 +0000
Subject: [PATCH] Return UnknownVal for pointer arithmetic on struct fields.

llvm-svn: 73851
---
 clang/lib/Analysis/RegionStore.cpp | 7 ++++++-
 clang/test/Analysis/fields.c       | 9 +++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Analysis/RegionStore.cpp b/clang/lib/Analysis/RegionStore.cpp
index 6f316c9c5921..5f2b8f809de3 100644
--- a/clang/lib/Analysis/RegionStore.cpp
+++ b/clang/lib/Analysis/RegionStore.cpp
@@ -773,8 +773,13 @@ SVal RegionStoreManager::EvalBinOp(const GRState *state,
     SVal ZeroIdx = ValMgr.makeZeroArrayIndex();
     ER = MRMgr.getElementRegion(EleTy, ZeroIdx, AR, getContext());
   } 
-  else
+  else if (isa<FieldRegion>(MR)) {
+    // Not track pointer arithmetic on struct fields.
+    return UnknownVal();
+  }
+  else {
     ER = cast<ElementRegion>(MR);
+  }
 
   SVal Idx = ER->getIndex();
 
diff --git a/clang/test/Analysis/fields.c b/clang/test/Analysis/fields.c
index c012a9da7b81..900a6d6869ac 100644
--- a/clang/test/Analysis/fields.c
+++ b/clang/test/Analysis/fields.c
@@ -8,3 +8,12 @@ void bar() {
   *(unsigned*)&y = foo();
   y.x = 1;
 }
+
+struct s {
+  int n;
+};
+
+void f() {
+  struct s a;
+  int *p = &(a.n) + 1;
+}