From be36ecbb60c1e18d0a9ffc8e6b780c0148ddfce1 Mon Sep 17 00:00:00 2001
From: Zhongxing Xu <xuzhongxing@gmail.com>
Date: Sun, 14 Feb 2010 06:49:48 +0000
Subject: Fix pr6293. If ptr is NULL, no operation is preformed.

llvm-svn: 96154
---
 clang/lib/Checker/MallocChecker.cpp | 5 +++++
 clang/test/Analysis/malloc.c        | 4 ++++
 2 files changed, 9 insertions(+)

(limited to 'clang')

diff --git a/clang/lib/Checker/MallocChecker.cpp b/clang/lib/Checker/MallocChecker.cpp
index 3be2e0299bb..4ff98642e1c 100644
--- a/clang/lib/Checker/MallocChecker.cpp
+++ b/clang/lib/Checker/MallocChecker.cpp
@@ -172,6 +172,11 @@ void MallocChecker::FreeMem(CheckerContext &C, const CallExpr *CE) {
 const GRState *MallocChecker::FreeMemAux(CheckerContext &C, const CallExpr *CE,
                                          const GRState *state) {
   SVal ArgVal = state->getSVal(CE->getArg(0));
+
+  // If ptr is NULL, no operation is preformed.
+  if (ArgVal.isZeroConstant())
+    return state;
+
   SymbolRef Sym = ArgVal.getAsLocSymbol();
   assert(Sym);
 
diff --git a/clang/test/Analysis/malloc.c b/clang/test/Analysis/malloc.c
index 518ab82ff11..3cce1b0d2ef 100644
--- a/clang/test/Analysis/malloc.c
+++ b/clang/test/Analysis/malloc.c
@@ -57,3 +57,7 @@ void pr6069() {
   char *buf = doit2();
   free(buf);
 }
+
+void pr6293() {
+  free(0);
+}
-- 
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