[Bug tree-optimization/88771] [9 Regression] Misleading -Werror=array-bounds error

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88771

--- Comment #19 from Martin Sebor <msebor at gcc dot gnu.org> ---
Author: msebor
Date: Mon Feb 11 17:44:05 2019
New Revision: 268775

URL: https://gcc.gnu.org/viewcvs?rev=268775&root=gcc&view=rev
Log:
PR tree-optimization/88771 - Misleading -Werror=array-bounds error

gcc/ChangeLog:

        PR tree-optimization/88771
        * gimple-ssa-warn-restrict.c (pass_wrestrict::gate): Also enable
        when -Wstringop-overflow is set.
        (builtin_memref::builtin_memref): Adjust excessive upper bound
        only when lower bound is not excessive.
        (maybe_diag_overlap): Detect and diagnose excessive bounds via
        -Wstringop-ovefflow.
        (maybe_diag_offset_bounds): Rename...
        (maybe_diag_access_bounds): ...to this.
        (check_bounds_or_overlap): Adjust for name change above.

gcc/testsuite/ChangeLog:

        PR tree-optimization/88771
        * gcc.dg/Wstringop-overflow-8.c: New test.
        * gcc.dg/Wstringop-overflow-9.c: New test.
        * gcc.dg/Warray-bounds-40.c: New test.
        * gcc.dg/builtin-stpncpy.c: Adjust.
        * gcc.dg/builtin-stringop-chk-4.c: Adjust.
        * g++.dg/opt/memcpy1.C: Adjust.


Added:
    trunk/gcc/testsuite/gcc.dg/Warray-bounds-40.c
    trunk/gcc/testsuite/gcc.dg/Wstringop-overflow-8.c
    trunk/gcc/testsuite/gcc.dg/Wstringop-overflow-9.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/gimple-ssa-warn-restrict.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/opt/memcpy1.C
    trunk/gcc/testsuite/gcc.dg/builtin-stpncpy.c
    trunk/gcc/testsuite/gcc.dg/builtin-stringop-chk-4.c