[Bug tree-optimization/83698] bogus offset in -Wrestrict messages for strcat of unknown strings

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83698

--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
Author: msebor
Date: Wed Feb 14 23:22:15 2018
New Revision: 257676

URL: https://gcc.gnu.org/viewcvs?rev=257676&root=gcc&view=rev
Log:
PR tree-optimization/83698 - bogus offset in -Wrestrict messages for strcat of
unknown strings

gcc/ChangeLog:

        PR tree-optimization/83698
        * gimple-ssa-warn-restrict.c (builtin_memref::builtin_memref): For
        arrays constrain the offset range to their bounds.
        (builtin_access::strcat_overlap): Adjust the bounds of overlap offset.
        (builtin_access::overlap): Avoid setting the size of overlap if it's
        already been set.
        (maybe_diag_overlap): Also consider arrays when deciding what values
        of offsets to include in diagnostics.

gcc/testsuite/ChangeLog:

        PR tree-optimization/83698
        * gcc.dg/Wrestrict-7.c: New test.
        * c-c++-common/Wrestrict.c: Adjust expected values for strcat.
        * gcc.target/i386/chkp-stropt-17.c: Same.


Added:
    trunk/gcc/testsuite/gcc.dg/Wrestrict-7.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/gimple-ssa-warn-restrict.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/c-c++-common/Wrestrict.c
    trunk/gcc/testsuite/gcc.target/i386/chkp-stropt-17.c