[Bug tree-optimization/82945] add warning for passing non-strings to functions that expect string arguments

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82945

--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
Author: msebor
Date: Tue Nov 21 20:01:58 2017
New Revision: 255031

URL: https://gcc.gnu.org/viewcvs?rev=255031&root=gcc&view=rev
Log:
PR tree-optimization/82945 - add warning for passing non-strings to functions
that expect string arguments

gcc/ChangeLog:

        PR tree-optimization/82945
        * builtins.c (expand_builtin_strlen): Call maybe_warn_nonstring_arg.
        * calls.h (maybe_warn_nonstring_arg): Declare new function.
        * calls.c (get_attr_nonstring_decl, maybe_warn_nonstring_arg): New
        functions.
        (initialize_argument_information): Call maybe_warn_nonstring_arg.
        * calls.h (get_attr_nonstring_decl): Declare new function.
        * doc/extend.texi (attribute nonstring): Update.
        * gimple-fold.c (gimple_fold_builtin_strncpy): Call
        get_attr_nonstring_decl and handle it.
        * tree-ssa-strlen.c (maybe_diag_stxncpy_trunc): Same.  Improve
        detection of nul-termination.
        (strlen_to_stridx): Change to a pointer.
        (handle_builtin_strlen, handle_builtin_stxncpy): Adjust.
        (pass_strlen::execute): Same.

gcc/testsuite/ChangeLog:

        PR tree-optimization/82945
        * c-c++-common/Wstringop-truncation-2.c: New test.
        * c-c++-common/Wstringop-truncation.c: Adjust.
        * c-c++-common/attr-nonstring-2.c: Adjust.
        * c-c++-common/attr-nonstring-3.c: New test.


Added:
    trunk/gcc/testsuite/c-c++-common/Wstringop-truncation-2.c
    trunk/gcc/testsuite/c-c++-common/attr-nonstring-3.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/builtins.c
    trunk/gcc/calls.c
    trunk/gcc/calls.h
    trunk/gcc/doc/extend.texi
    trunk/gcc/gimple-fold.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/c-c++-common/Wstringop-truncation.c
    trunk/gcc/testsuite/c-c++-common/attr-nonstring-2.c
    trunk/gcc/tree-ssa-strlen.c