[Bug middle-end/85602] -Wsizeof-pointer-memaccess for strncat with size of source

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85602

--- Comment #14 from Martin Sebor <msebor at gcc dot gnu.org> ---
Author: msebor
Date: Wed Jul 18 17:20:05 2018
New Revision: 262859

URL: https://gcc.gnu.org/viewcvs?rev=262859&root=gcc&view=rev
Log:
Backport from trunk.

PR middle-end/85602 - -Wsizeof-pointer-memaccess for strncat with size of
source

gcc/c-family/ChangeLog:

        PR middle-end/85602
        * c-warn.c (sizeof_pointer_memaccess_warning): Check for attribute
        nonstring.

gcc/ChangeLog:

        PR middle-end/85602
        * calls.c (maybe_warn_nonstring_arg): Handle strncat.
        * tree-ssa-strlen.c (is_strlen_related_p): Make extern.
        Handle integer subtraction.
        (maybe_diag_stxncpy_trunc): Handle nonstring source arguments.
        * tree-ssa-strlen.h (is_strlen_related_p): Declare.
        * doc/invoke.texi (-Wstringop-truncation): Update.

gcc/testsuite/ChangeLog:

        PR middle-end/85602
        * gcc.dg/attr-nonstring-2.c: Adjust text of expected warning.
        * c-c++-common/attr-nonstring-8.c: New test.


Added:
    branches/gcc-8-branch/gcc/testsuite/c-c++-common/attr-nonstring-8.c
Modified:
    branches/gcc-8-branch/gcc/ChangeLog
    branches/gcc-8-branch/gcc/c-family/ChangeLog
    branches/gcc-8-branch/gcc/c-family/c-warn.c
    branches/gcc-8-branch/gcc/calls.c
    branches/gcc-8-branch/gcc/doc/invoke.texi
    branches/gcc-8-branch/gcc/testsuite/ChangeLog
    branches/gcc-8-branch/gcc/tree-ssa-strlen.c
    branches/gcc-8-branch/gcc/tree-ssa-strlen.h