[Bug c/43651] add warning for duplicate qualifier

["miyuki at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43651

--- Comment #8 from Mikhail Maltsev <miyuki at gcc dot gnu.org> ---
Author: miyuki
Date: Wed May 11 20:23:37 2016
New Revision: 236142

URL: https://gcc.gnu.org/viewcvs?rev=236142&root=gcc&view=rev
Log:
PR43651: add warning for duplicate qualifier

gcc/c/

        PR c/43651
        * c-decl.c (declspecs_add_qual): Warn when -Wduplicate-decl-specifier
        is enabled.
        * c-errors.c (pedwarn_c90): Return true if warned.
        * c-tree.h (pedwarn_c90): Change return type to bool.
        (enum c_declspec_word): Add new enumerator cdw_atomic.

gcc/

        PR c/43651
        * doc/invoke.texi (Wduplicate-decl-specifier): Document new option.

gcc/testsuite/

        PR c/43651
        * gcc.dg/Wduplicate-decl-specifier-c11.c: New test.
        * gcc.dg/Wduplicate-decl-specifier.c: Likewise.

gcc/c-family/

        PR c/43651
        * c.opt (Wduplicate-decl-specifier): New option.

Added:
    trunk/gcc/testsuite/gcc.dg/Wduplicate-decl-specifier-c11.c
    trunk/gcc/testsuite/gcc.dg/Wduplicate-decl-specifier.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-family/ChangeLog
    trunk/gcc/c-family/c.opt
    trunk/gcc/c/ChangeLog
    trunk/gcc/c/c-decl.c
    trunk/gcc/c/c-errors.c
    trunk/gcc/c/c-tree.h
    trunk/gcc/doc/invoke.texi
    trunk/gcc/testsuite/ChangeLog