[Bug driver/115440] unrecognized command-line option '--c++17'; did you mean '--stdc++17'?

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115440

--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:e216eb16ef740c4e820a24c73e7d7e97a12d93c3

commit r13-8859-ge216eb16ef740c4e820a24c73e7d7e97a12d93c3
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Mon Jun 17 22:02:46 2024 +0200

    diagnostics: Fix add_misspelling_candidates [PR115440]

    The option_map array for most entries contains just non-NULL opt0
        { "-Wno-", NULL, "-W", false, true },
        { "-fno-", NULL, "-f", false, true },
        { "-gno-", NULL, "-g", false, true },
        { "-mno-", NULL, "-m", false, true },
        { "--debug=", NULL, "-g", false, false },
        { "--machine-", NULL, "-m", true, false },
        { "--machine-no-", NULL, "-m", false, true },
        { "--machine=", NULL, "-m", false, false },
        { "--machine=no-", NULL, "-m", false, true },
        { "--machine", "", "-m", false, false },
        { "--machine", "no-", "-m", false, true },
        { "--optimize=", NULL, "-O", false, false },
        { "--std=", NULL, "-std=", false, false },
        { "--std", "", "-std=", false, false },
        { "--warn-", NULL, "-W", true, false },
        { "--warn-no-", NULL, "-W", false, true },
        { "--", NULL, "-f", true, false },
        { "--no-", NULL, "-f", false, true }
    and so add_misspelling_candidates works correctly for it, but 3 out of
    these,
        { "--machine", "", "-m", false, false },
        { "--machine", "no-", "-m", false, true },
    and
        { "--std", "", "-std=", false, false },
    use non-NULL opt1.  That says that
    --machine foo
    should map to
    -mfoo
    and
    --machine no-foo
    should map to
    -mno-foo
    and
    --std c++17
    should map to
    -std=c++17
    add_misspelling_canidates was not handling this, so it hapilly
    registered say
    --stdc++17
    or
    --machineavx512
    (twice) as spelling alternatives, when those options aren't recognized.
    Instead we support
    --std c++17
    or
    --machine avx512
    --machine no-avx512

    The following patch fixes that.  On this particular testcase, we no longer
    suggest anything, even when among the suggestion is say that
    --std c++17
    or
    -std=c++17
    etc.

    2024-06-17  Jakub Jelinek  <jakub@redhat.com>

            PR driver/115440
            * opts-common.cc (add_misspelling_candidates): If opt1 is non-NULL,
            add a space and opt1 to the alternative suggestion text.

            * g++.dg/cpp1z/pr115440.C: New test.

    (cherry picked from commit 96db57948b50f45235ae4af3b46db66cae7ea859)