1 files changed, 51 insertions, 0 deletions
diff --git a/exp-sgcheck/tests/unaligned.c b/exp-sgcheck/tests/unaligned.c
new file mode 100644
index 00000000..6c7ba39d
--- /dev/null
+++ b/exp-sgcheck/tests/unaligned.c
@@ -0,0 +1,51 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main ( void )
+{
+   char* x = strdup("hello");
+   char c __attribute__((unused));
+   char c0[8], c1[8], c2[8], c3[8], c4[8];
+
+   // Each of these pointers has a different alignment
+   char** p0 = (char**)&c0[0];   char** p1 = (char**)&c1[1];
+   char** p2 = (char**)&c2[2];   char** p3 = (char**)&c3[3];
+   char** p4 = (char**)&c4[4];
+   *p0 = x;   *p1 = x;   *p2 = x;
+   *p3 = x;   *p4 = x;
+
+   // These 10 are ok
+   c = (*p0)[0];
+   c = (*p1)[0];
+   c = (*p2)[0];
+   c = (*p3)[0];
+   c = (*p4)[0];
+
+   c = (*p0)[5];
+   c = (*p1)[5];
+   c = (*p2)[5];
+   c = (*p3)[5];
+   c = (*p4)[5];
+
+   // These 10 are bad
+   c = (*p0)[-1];    // always word aligned, so det
+   c = (*p1)[-1];    // undet
+   c = (*p2)[-1];    // undet
+   c = (*p3)[-1];    // undet
+   c = (*p4)[-1];    // undet on 64-bit since not 64-bit aligned
+
+   c = (*p0)[6];     // always word aligned, so det
+   c = (*p1)[6];     // undet
+   c = (*p2)[6];     // undet
+   c = (*p3)[6];     // undet
+   c = (*p4)[6];     // undet on 64-bit since not 64-bit aligned
+
+   return 0;
+}
+
+/* What this program does: verifies that (unfortunately) if you store a
+   pointer misaligned, then the associated shadow value decays to Unknown,
+   and so when you retrieve the pointer later and dereference it, you
+   get no check :-( */