https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82967
--- Comment #10 from David Malcolm <dmalcolm at gcc dot gnu.org> --- Author: dmalcolm Date: Fri Sep 14 22:02:58 2018 New Revision: 264335 URL: https://gcc.gnu.org/viewcvs?rev=264335&root=gcc&view=rev Log: Fix overeager spelling corrections (PR c/82967) This patch tunes class best_match's cutoff for rejecting meaningless spelling suggestions. Previously, we allowed an edit distance of up to half of the length of the longer of the goal string and closest candidate strings, rounded down. With this patch, we now allow only up to a third - with some tuning of rounding (and for very short strings), to ensure that: (a) everything that worked before still works (with the removal of a couple of cases that shouldn't), and that (b) the new threshold is always at least as conservative as the old threshold and thus shouldn't offer new nonsensical suggestions (with the possible exception of cases where transposition has helped; see r261521 aka Damerau-Levenshtein; PR other/69968). In particular, all of the bogus suggestions from PR c/82967 are now no longer offered. gcc/ChangeLog: PR c/82967 * spellcheck.c (get_edit_distance_cutoff): New function. (selftest::test_edit_distance_unit_test_oneway): Rename to... (selftest::test_get_edit_distance_one_way): ...this. (selftest::test_get_edit_distance_unit): Rename to... (selftest::test_get_edit_distance_both_ways): ...this. (selftest::test_edit_distances): Move tests to this new function, and test some more pairs of strings. Update for above renaming. (selftest::get_old_cutoff): New function. (selftest::test_get_edit_distance_cutoff): New function. (selftest::assert_suggested_for): New function. (ASSERT_SUGGESTED_FOR): New macro. (selftest::assert_not_suggested_for): New function. (ASSERT_NOT_SUGGESTED_FOR): New macro. (selftest::test_suggestions): New function. (selftest::spellcheck_c_tests): Move test_get_edit_distance_unit tests to selftest::test_edit_distances and call it. Add calls to selftest::test_get_edit_distance_cutoff and selftest::test_suggestions. * spellcheck.h (get_edit_distance_cutoff): New function declaration. (best_match::consider): Replace hard-coded cutoff calculation with a call to... (best_match::get_cutoff): New declaration. (best_match::get_best_meaningful_candidate): Likewise. gcc/testsuite/ChangeLog: PR c/82967 * c-c++-common/attributes-1.c: Remove bogus suggestion from dg-prune-output. * gcc.dg/diagnostic-token-ranges.c (undeclared_identifier): Remove bogus suggestion. * gcc.dg/spellcheck-identifiers-4.c: New test. Added: trunk/gcc/testsuite/gcc.dg/spellcheck-identifiers-4.c Modified: trunk/gcc/ChangeLog trunk/gcc/spellcheck.c trunk/gcc/spellcheck.h trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/c-c++-common/attributes-1.c trunk/gcc/testsuite/gcc.dg/diagnostic-token-ranges.c
