[Bug c/68325] missing -Warray-bounds on a negative subscript into a flexible array member

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68325

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
      Known to work|                            |8.0
         Resolution|---                         |FIXED
   Target Milestone|---                         |8.0
      Known to fail|                            |5.4.0, 6.4.0, 7.2.0

--- Comment #2 from Martin Sebor <msebor at gcc dot gnu.org> ---
Fixed in r254830.  GCC now issues the warnings below for the test case in
comment #0:

z.c: In function ‘foo’:
z.c:7:16: warning: array subscript -2147483647 is below array bounds of
‘int[99]’ [-Warray-bounds]
     return s.a [-__INT_MAX__];
            ~~~~^~~~~~~~~~~~~~
z.c: In function ‘bar’:
z.c:12:17: warning: array subscript -2147483647 is below array bounds of
‘int[99]’ [-Warray-bounds]
     return p->a [-__INT_MAX__];
            ~~~~~^~~~~~~~~~~~~~