[Bug sanitizer/71498] New: ubsan bounds checking influenced by surrounding code

[jan.sm...@alcatel-lucent.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71498

            Bug ID: 71498
           Summary: ubsan bounds checking influenced by surrounding code
           Product: gcc
           Version: 5.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: sanitizer
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jan.sm...@alcatel-lucent.com
                CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
                    jakub at gcc dot gnu.org, kcc at gcc dot gnu.org
  Target Milestone: ---

$ gcc -c /tmp/test.c -o - -S -fsanitize=bounds |grep ubsan_handle
        call    __ubsan_handle_out_of_bounds
$ gcc -c /tmp/test.c -o - -S -fsanitize=bounds |grep ubsan_handle
$

int a[100];
extern void call(const char * fn);
int testje (int core)
{
    #if 1
        // OK
        call("har har");
    #else
        // NOK
        call(__FUNCTION__);
    #endif

   return a[core];

}