From: Ted Kremenek <kremenek@apple.com>
Date: Sat, 21 Nov 2009 02:17:47 +0000 (+0000)
Subject: Add another test case to show the precision of RegionStore over
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8ea06e95c396aa56a24cc9325d7ac6b27422adcf;p=clang

Add another test case to show the precision of RegionStore over
BasicStore.  In this example, BasicStore would lose information about
the pointer in path after '*path++', causing the analyzer to falsely
flag a null dereference.  This addresses <rdar://problem/7191542>.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@89533 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/test/Analysis/misc-ps-region-store.m b/test/Analysis/misc-ps-region-store.m
index 23199b6361..fe45823fe4 100644
--- a/test/Analysis/misc-ps-region-store.m
+++ b/test/Analysis/misc-ps-region-store.m
@@ -509,3 +509,26 @@ void rdar7403269_b_pos() {
   *p = 0xDEADBEEF; // expected-warning{{Dereference of null pointer}}
 }
 
+
+//===----------------------------------------------------------------------===//
+// Test that incrementing a non-null pointer results in a non-null pointer.
+// (<rdar://problem/7191542>)
+//===----------------------------------------------------------------------===//
+
+void test_increment_nonnull_rdar_7191542(const char *path) {
+  const char *alf = 0;
+  
+  for (;;) {
+    // When using basic-store, we get a null dereference here because we lose information
+    // about path after the pointer increment.
+    char c = *path++; // no-warning
+    if (c == 'a') {
+      alf = path;
+    }
+    
+    if (alf)
+      return;
+  }
+}
+
+