[Bug tree-optimization/84051] [6/7/8 Regression] missing -Warray-bounds on an out-of-bounds access via an array pointer

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84051

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
      Known to work|                            |4.5.4
            Summary|missing -Warray-bounds on   |[6/7/8 Regression] missing
                   |an out-of-bounds access via |-Warray-bounds on an
                   |an array pointer            |out-of-bounds access via an
                   |                            |array pointer
      Known to fail|                            |4.6.4, 4.7.4, 4.8.4, 4.9.4,
                   |                            |5.5.0, 6.4.0, 7.2.0, 8.0

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
Bisection points to either r158060 or r158060, both committed into GCC 4.6. 
The latter seems like the more likely culprit:

2010-04-07  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/43270
        * tree-vrp.c (check_array_ref): Fix flexible array member
        detection.
        * tree-ssa-sccvn.h (fully_constant_vn_reference_p): Declare.
        * tree-ssa-pre.c (phi_translate_1): Adjust.
        (fully_constant_expression): Split out vn_reference handling to ...
        * tree-ssa-sccvn.c (fully_constant_vn_reference_p): ... here.
        Fold reads from constant strings.
        (vn_reference_lookup): Handle fully constant references.
        (vn_reference_lookup_pieces): Likewise.
        * Makefile.in (expmed.o-warn): Add -Wno-error.