[Bug tree-optimization/78913] Probably misleading error reported by -Wformat-length

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78913

--- Comment #10 from Martin Sebor <msebor at gcc dot gnu.org> ---
Author: msebor
Date: Sun Jan  8 23:42:09 2017
New Revision: 244210

URL: https://gcc.gnu.org/viewcvs?rev=244210&root=gcc&view=rev
Log:
PR tree-optimization/78913 - Probably misleading error reported by
-Wformat-length
PR middle-end/77708 - -Wformat-length %s warns for snprintf

gcc/ChangeLog:

        PR middle-end/77708
        * doc/invoke.texi (Warning Options): Document -Wformat-truncation.
        * gimple-ssa-sprintf.c (call_info::reval_used, call_info::warnopt):
        New member functions.
        (format_directive): Used them.
        (add_bytes): Same.
        (pass_sprintf_length::handle_gimple_call): Same.
        * graphite-sese-to-poly.c (tree_int_to_gmp): Increase buffer size
        to avoid truncation for any argument.
        (extract_affine_mul): Same.
        * tree.c (get_file_function_name): Same.

gcc/c-family/ChangeLog:

        PR middle-end/77708
        * c.opt (-Wformat-truncation): New option.

gcc/fortran/ChangeLog:

        PR tree-optimization/78913
        PR middle-end/77708
        * trans-common.c (build_equiv_decl): Increase buffer size to avoid
        truncation for any argument.
        * trans-types.c (gfc_build_logical_type): Same.

gcc/testsuite/ChangeLog:

        PR middle-end/77708
        * gcc.dg/tree-ssa/builtin-snprintf-warn-1.c: New test.
        * gcc.dg/tree-ssa/builtin-snprintf-warn-2.c: New test.
        * gcc.dg/tree-ssa/builtin-sprintf-warn-6.c: XFAIL test cases failing
        due to bug 78969.
        * gcc.dg/format/pr78569.c: Adjust.


Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/builtin-snprintf-warn-1.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/builtin-snprintf-warn-2.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-family/ChangeLog
    trunk/gcc/c-family/c.opt
    trunk/gcc/doc/invoke.texi
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/trans-common.c
    trunk/gcc/fortran/trans-types.c
    trunk/gcc/gimple-ssa-sprintf.c
    trunk/gcc/graphite-sese-to-poly.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/format/pr78569.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/builtin-sprintf-warn-6.c
    trunk/gcc/tree.c