Invalidate the alloca region by setting its default value to conjured symbol.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@74419 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Analysis/array-struct.c b/test/Analysis/array-struct.c
index 1303576..da7df4b 100644
--- a/test/Analysis/array-struct.c
+++ b/test/Analysis/array-struct.c
@@ -168,3 +168,15 @@
   if (t.e.d)
     x = 1;
 }
+
+void read(char*);
+
+void f18() {
+  char *q;
+  char *p = (char *) __builtin_alloca(10);
+  read(p);
+  q = p;
+  q++;
+  if (*q) { // no-warning
+  }
+}