1 files changed, 37 insertions, 0 deletions
diff --git a/test/Analysis/null-deref-offsets.c b/test/Analysis/null-deref-offsets.c
new file mode 100644
index 0000000000000..988cec4985daa
--- /dev/null
+++ b/test/Analysis/null-deref-offsets.c
@@ -0,0 +1,37 @@
+// RUN: %clang_analyze_cc1 -w -triple i386-apple-darwin10 -analyzer-checker=core,debug.ExprInspection -verify %s
+
+void clang_analyzer_eval(int);
+
+struct S {
+  int x, y;
+  int z[2];
+};
+
+void testOffsets(struct S *s, int coin) {
+  if (s != 0)
+    return;
+
+  // FIXME: Here we are testing the hack that computes offsets to null pointers
+  // as 0 in order to find null dereferences of not-exactly-null pointers,
+  // such as &(s->y) below, which is equal to 4 rather than 0 in run-time.
+
+  // These are indeed null.
+  clang_analyzer_eval(s == 0); // expected-warning{{TRUE}}
+  clang_analyzer_eval(&(s->x) == 0); // expected-warning{{TRUE}}
+
+  // FIXME: These should ideally be true.
+  clang_analyzer_eval(&(s->y) == 4); // expected-warning{{FALSE}}
+  clang_analyzer_eval(&(s->z[0]) == 8); // expected-warning{{FALSE}}
+  clang_analyzer_eval(&(s->z[1]) == 12); // expected-warning{{FALSE}}
+
+  // FIXME: These should ideally be false.
+  clang_analyzer_eval(&(s->y) == 0); // expected-warning{{TRUE}}
+  clang_analyzer_eval(&(s->z[0]) == 0); // expected-warning{{TRUE}}
+  clang_analyzer_eval(&(s->z[1]) == 0); // expected-warning{{TRUE}}
+
+  // But these should still be reported as null dereferences.
+  if (coin)
+    s->y = 5; // expected-warning{{Access to field 'y' results in a dereference of a null pointer (loaded from variable 's')}}
+  else
+    s->z[1] = 6; // expected-warning{{Array access (via field 'z') results in a null pointer dereference}}
+}