From 035cf930d51b890ecd67805d27baf70d8d2c0038 Mon Sep 17 00:00:00 2001
From: Ted Kremenek <kremenek@apple.com>
Date: Sat, 28 Mar 2009 19:59:33 +0000
Subject: [PATCH] Fix regression in pointer comparison with NULL (e.g., 0 !=
 ptr). This fixes <rdar://problem/6732151>.

llvm-svn: 67954
---
 clang/lib/Analysis/GRSimpleVals.cpp | 10 ++++------
 clang/test/Analysis/CheckNSError.m  | 16 ++++++++++++++--
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/clang/lib/Analysis/GRSimpleVals.cpp b/clang/lib/Analysis/GRSimpleVals.cpp
index a38d76d26080..8e605ca4c783 100644
--- a/clang/lib/Analysis/GRSimpleVals.cpp
+++ b/clang/lib/Analysis/GRSimpleVals.cpp
@@ -375,13 +375,11 @@ TryAgain:
         
         return NonLoc::MakeIntTruthVal(BasicVals, b);
       }
-      else if (isa<loc::SymbolVal>(R)) {
+      else if (SymbolRef Sym = R.getAsSymbol()) {
         const SymIntExpr * SE =
-        Eng.getSymbolManager().getSymIntExpr(
-                                    cast<loc::SymbolVal>(R).getSymbol(),
-                                    BinaryOperator::NE,
-                                    cast<loc::ConcreteInt>(L).getValue(),
-                                    Eng.getContext().IntTy);
+          Eng.getSymbolManager().getSymIntExpr(Sym, BinaryOperator::NE,
+                                           cast<loc::ConcreteInt>(L).getValue(),
+                                             Eng.getContext().IntTy);
         return nonloc::SymExprVal(SE);
       }
       
diff --git a/clang/test/Analysis/CheckNSError.m b/clang/test/Analysis/CheckNSError.m
index 28435727eb79..779b865aff8c 100644
--- a/clang/test/Analysis/CheckNSError.m
+++ b/clang/test/Analysis/CheckNSError.m
@@ -41,7 +41,19 @@ void foo(CFErrorRef* error) { // expected-warning {{Function accepting CFErrorRe
   *error = 0;  // expected-warning {{Potential null dereference.}}
 }
 
-int bar(CFErrorRef* error) {
-  if (error) *error = 0;
+int f1(CFErrorRef* error) {
+  if (error) *error = 0; // no-warning
   return 0;
 }
+
+int f2(CFErrorRef* error) {
+  if (0 != error) *error = 0; // no-warning
+  return 0;
+}
+
+int f3(CFErrorRef* error) {
+  if (error != 0) *error = 0; // no-warning
+  return 0;
+}
+
+