https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115440
--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:96db57948b50f45235ae4af3b46db66cae7ea859 commit r15-1384-g96db57948b50f45235ae4af3b46db66cae7ea859 Author: Jakub Jelinek <ja...@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 <ja...@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.