PR driver/69265 and 69453: improved suggestions for various misspelled options

gcc/ChangeLog:
	PR driver/69265
	PR driver/69453
	* gcc.c (driver::driver): Initialize m_option_suggestions.
	(driver::~driver): Clean up m_option_suggestions.
	(suggest_option): Convert to...
	(driver::suggest_option): ...this, and split out into
	driver::build_option_suggestions and find_closest_string.
	(driver::build_option_suggestions): New function, from
	first half of suggest_option.  Special-case
	OPT_fsanitize_ and OPT_fsanitize_recover_, making use of
	the sanitizer_opts array.  For options of enum types, add the
	various enum values to the candidate strings.
	(driver::handle_unrecognized_options): Remove "const".
	* gcc.h (driver::handle_unrecognized_options): Likewise.
	(driver::build_option_suggestions): New decl.
	(driver::suggest_option): New decl.
	(driver::m_option_suggestions): New field.
	* opts-common.c (add_misspelling_candidates): New function.
	* opts.c (sanitizer_opts): Remove decl of struct sanitizer_opts_s
	and make non-static.
	* opts.h (sanitizer_opts): New array decl.
	(add_misspelling_candidates): New function decl.
	* spellcheck.c (find_closest_string): New function.
	* spellcheck.h (find_closest_string): New function decl.

gcc/testsuite/ChangeLog:
	PR driver/69265
	PR driver/69453
	* gcc.dg/spellcheck-options-3.c: New test case.
	* gcc.dg/spellcheck-options-4.c: New test case.
	* gcc.dg/spellcheck-options-5.c: New test case.
	* gcc.dg/spellcheck-options-6.c: New test case.
	* gcc.dg/spellcheck-options-7.c: New test case.
	* gcc.dg/spellcheck-options-8.c: New test case.
	* gcc.dg/spellcheck-options-9.c: New test case.
	* gcc.dg/spellcheck-options-10.c: New test case.

From-SVN: r233382

1 files changed, 41 insertions, 0 deletions

diff --git a/gcc/opts-common.c b/gcc/opts-common.c
index 38c805837d4..bb689827227 100644
--- a/gcc/opts-common.c
+++ b/gcc/opts-common.c
@@ -365,6 +365,47 @@ static const struct option_map option_map[] =
     { "--no-", NULL, "-f", false, true }
   };
 
+/* Helper function for gcc.c's driver::suggest_option, for populating the
+   vec of suggestions for misspelled options.
+
+   option_map above provides various prefixes for spelling command-line
+   options, which decode_cmdline_option uses to map spellings of options
+   to specific options.  We want to do the reverse: to find all the ways
+   that a user could validly spell an option.
+
+   Given valid OPT_TEXT (with a leading dash), add it and all of its valid
+   variant spellings to CANDIDATES, each without a leading dash.
+
+   For example, given "-Wabi-tag", the following are added to CANDIDATES:
+     "Wabi-tag"
+     "Wno-abi-tag"
+     "-warn-abi-tag"
+     "-warn-no-abi-tag".
+
+   The added strings must be freed using free.  */
+
+void
+add_misspelling_candidates (auto_vec<char *> *candidates,
+			    const char *opt_text)
+{
+  gcc_assert (candidates);
+  gcc_assert (opt_text);
+  candidates->safe_push (xstrdup (opt_text + 1));
+  for (unsigned i = 0; i < ARRAY_SIZE (option_map); i++)
+    {
+      const char *opt0 = option_map[i].opt0;
+      const char *new_prefix = option_map[i].new_prefix;
+      size_t new_prefix_len = strlen (new_prefix);
+
+      if (strncmp (opt_text, new_prefix, new_prefix_len) == 0)
+	{
+	  char *alternative = concat (opt0 + 1, opt_text + new_prefix_len,
+				      NULL);
+	  candidates->safe_push (alternative);
+	}
+    }
+}
+
 /* Decode the switch beginning at ARGV for the language indicated by
    LANG_MASK (including CL_COMMON and CL_TARGET if applicable), into
    the structure *DECODED.  Returns the number of switches