[Bug c/91092] Error on implicit function declarations by default

[cvs-commit at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91092

--- Comment #22 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Florian Weimer <f...@gcc.gnu.org>:

https://gcc.gnu.org/g:55e94561e97ed0bce4774aa1c6b5d5d82209a379

commit r14-6033-g55e94561e97ed0bce4774aa1c6b5d5d82209a379
Author: Florian Weimer <fwei...@redhat.com>
Date:   Fri Dec 1 08:10:13 2023 +0100

    c: Turn -Wimplicit-function-declaration into a permerror

    In the future, it may make sense to avoid cascading errors from
    the implicit declaration, especially its assumed int return type.
    This change here only changes the kind of the diagnostic, not
    its wording or consequences.

    gcc/

            * doc/invoke.texi (Warning Options): Document changes.

    gcc/c/

            PR c/91092
            PR c/96284
            * c-decl.cc (implicit_decl_permerror): Rename from
            implicit_decl_warning.  Call permerror_opt instead of
            pedwarn and warning_at.
            (implicitly_declare): Adjust callers.

    gcc/testsuite/

            * gcc.dg/permerror-default.c (implicit_function_declaration):
            Expect the new permerror.
            * gcc.dg/permerror-system.c: Likewise.
            * c-c++-common/spellcheck-reserved.c (test, test_2): Expect
            error instead of warning.
            (f): Expect error instead of warning.
            * gcc.dg/Wimplicit-function-declaration-c99.c: Compile with
            -fpermissive due to expected warning.
            * gcc.dg/Wimplicit-function-declaration-c99-2.c: New test.
            Copied from gcc.dg/Wimplicit-function-declaration-c99.c.
            Expect error.
            * gcc.dg/missing-header-fixit-1.c: Compile with -fpermissive
            due to expect error.
            * gcc.dg/missing-header-fixit-1a.c: New test.  Copied from
            gcc.dg/missing-header-fixit-1.c, but expect error.
            * gcc.dg/missing-header-fixit-2.c: Compile with -fpermissive
            due to expect error.
            * gcc.dg/missing-header-fixit-2a.c: New test.  Copied from
            gcc.dg/missing-header-fixit-2.c, but expect error.
            * gcc.dg/missing-header-fixit-4.c: Compile with -fpermissive
            due to expect error.
            * gcc.dg/missing-header-fixit-4a.c: New test.  Copied from
            gcc.dg/missing-header-fixit-4.c, but expect error.
            * gcc.dg/missing-header-fixit-5.c: Compile with -fpermissive
            due to expect error.
            * gcc.dg/missing-header-fixit-5a.c: New test.  Copied from
            gcc.dg/missing-header-fixit-5.c, but expect error.
            * gcc.dg/pr61852.c: Expect implicit-function-declaration
            error instead of warning.
            * gcc.dg/spellcheck-identifiers-2.c: Compile with
            -fpermissive due to expected warnings.
            * gcc.dg/spellcheck-identifiers-2a.c: New test.  Copied
            from gcc.dg/spellcheck-identifiers-2a.c.  Expect errors.
            * gcc.dg/spellcheck-identifiers-3.c: Compile with
            -fpermissive due to expected warnings.
            * gcc.dg/spellcheck-identifiers-3a.c: New test.  Copied
            from gcc.dg/spellcheck-identifiers-2a.c.  Expect errors.
            * gcc.dg/spellcheck-identifiers-4.c: Compile with
            -fpermissive due to expected warnings.
            * gcc.dg/spellcheck-identifiers-4a.c: New test.  Copied
            from gcc.dg/spellcheck-identifiers-2a.c.  Expect error.
            * gcc.dg/spellcheck-identifiers.c: Compile with
            -fpermissive due to expected warnings.
            * gcc.dg/spellcheck-identifiers-1a.c: New test.  Copied
            from gcc.dg/spellcheck-identifiers.c.  Expect errors.
            * gcc.target/aarch64/sve/acle/general-c/ld1sh_gather_1.c (f1):
            Expect error.
            * gcc.target/aarch64/sve/acle/general-c/load_ext_gather_index_1.c:
            (f1): Likewise.
            *
gcc.target/aarch64/sve/acle/general-c/load_ext_gather_index_restricted_1.c:
            (f1): Likewise.
            * gcc.target/aarch64/sve/acle/general-c/load_ext_gather_offset_1.c:
            (f1): Likewise.
            * gcc.target/aarch64/sve/acle/general-c/load_ext_gather_offset_2.c:
            (f1): Likewise.
            * gcc.target/aarch64/sve/acle/general-c/load_ext_gather_offset_3.c:
            (f1): Likewise.
            * gcc.target/aarch64/sve/acle/general-c/load_ext_gather_offset_4.c:
            (f1): Likewise.
            * gcc.target/aarch64/sve/acle/general-c/load_ext_gather_offset_5.c:
            (f1): Likewise.
            *
gcc.target/aarch64/sve/acle/general-c/load_ext_gather_offset_restricted_1.c:
            (f1): Likewise.
            *
gcc.target/aarch64/sve/acle/general-c/load_ext_gather_offset_restricted_2.c:
            (f1): Likewise.
            *
gcc.target/aarch64/sve/acle/general-c/load_ext_gather_offset_restricted_3.c:
            (f1): Likewise.
            *
gcc.target/aarch64/sve/acle/general-c/load_ext_gather_offset_restricted_4.c:
            (f1): Likewise.