c-family: add name_hint/deferred_diagnostic

In various places we use lookup_name_fuzzy to provide a hint,
and can report messages of the form:
  error: unknown foo named 'bar'
or:
  error: unknown foo named 'bar'; did you mean 'SUGGESTION?

This patch provides a way for lookup_name_fuzzy to provide
both the suggestion above, and (optionally) additional hints
that can be printed e.g.

  note: did you forget to include <SOME_HEADER.h>?

This patch provides the mechanism and ports existing users
of lookup_name_fuzzy to the new return type.
There are no uses of such hints in this patch, but followup
patches provide various front-end specific uses of this.

gcc/c-family/ChangeLog:
	* c-common.h (enum lookup_name_fuzzy_kind): Move to name-hint.h.
	(lookup_name_fuzzy): Likewise.  Convert return type from
	const char * to name_hint.  Add location_t param.
	* name-hint.h: New header.

gcc/c/ChangeLog:
	* c-decl.c: Define INCLUDE_UNIQUE_PTR before including system.h.
	Include "c-family/name-hint.h"
	(implicit_decl_warning): Convert "hint" from
	const char * to name_hint.  Pass location to
	lookup_name_fuzzy.  Suppress any deferred diagnostic if the
	warning was not printed.
	(undeclared_variable): Likewise for "guessed_id".
	(lookup_name_fuzzy): Convert return type from const char *
	to name_hint.  Add location_t param.
	* c-parser.c: Define INCLUDE_UNIQUE_PTR before including system.h.
	Include "c-family/name-hint.h"
	(c_parser_declaration_or_fndef): Convert "hint" from
	const char * to name_hint.  Pass location to lookup_name_fuzzy.
	(c_parser_parameter_declaration): Likewise.

gcc/cp/ChangeLog:
	* name-lookup.c: Define INCLUDE_UNIQUE_PTR before including system.h.
	Include "c-family/name-hint.h"
	(suggest_alternatives_for): Convert "fuzzy_name" from const char *
	to name_hint, and rename to "hint".  Pass location to
	lookup_name_fuzzy.
	(lookup_name_fuzzy): Convert return type from const char *
	to name_hint.  Add location_t param.
	* parser.c: Define INCLUDE_UNIQUE_PTR before including system.h.
	Include "c-family/name-hint.h"
	(cp_parser_diagnose_invalid_type_name): Convert
	"suggestion" from const char * to name_hint, and rename to "hint".
	Pass location to lookup_name_fuzzy.

From-SVN: r254963

1 files changed, 11 insertions, 7 deletions

diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index bd5dd57..4afa9ce 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -36,6 +36,7 @@ along with GCC; see the file COPYING3.  If not see
    location rather than implicitly using input_location.  */
 
 #include "config.h"
+#define INCLUDE_UNIQUE_PTR
 #include "system.h"
 #include "coretypes.h"
 #include "target.h"
@@ -65,6 +66,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "read-rtl-function.h"
 #include "run-rtl-passes.h"
 #include "intl.h"
+#include "c-family/name-hint.h"
 
 /* We need to walk over decls with incomplete struct/union/enum types
    after parsing the whole translation unit.
@@ -1808,13 +1810,14 @@ c_parser_declaration_or_fndef (c_parser *parser, bool fndef_ok,
 	}
       else
 	{
-	  const char *hint = lookup_name_fuzzy (name, FUZZY_LOOKUP_TYPENAME);
+	  name_hint hint = lookup_name_fuzzy (name, FUZZY_LOOKUP_TYPENAME,
+					      here);
 	  if (hint)
 	    {
-	      richloc.add_fixit_replace (hint);
+	      richloc.add_fixit_replace (hint.suggestion ());
 	      error_at (&richloc,
 			"unknown type name %qE; did you mean %qs?",
-			name, hint);
+			name, hint.suggestion ());
 	    }
 	  else
 	    error_at (here, "unknown type name %qE", name);
@@ -4066,15 +4069,16 @@ c_parser_parameter_declaration (c_parser *parser, tree attrs)
       c_parser_set_source_position_from_token (token);
       if (c_parser_next_tokens_start_typename (parser, cla_prefer_type))
 	{
-	  const char *hint = lookup_name_fuzzy (token->value,
-						FUZZY_LOOKUP_TYPENAME);
+	  name_hint hint = lookup_name_fuzzy (token->value,
+					      FUZZY_LOOKUP_TYPENAME,
+					      token->location);
 	  if (hint)
 	    {
 	      gcc_rich_location richloc (token->location);
-	      richloc.add_fixit_replace (hint);
+	      richloc.add_fixit_replace (hint.suggestion ());
 	      error_at (&richloc,
 			"unknown type name %qE; did you mean %qs?",
-			token->value, hint);
+			token->value, hint.suggestion ());
 	    }
 	  else
 	    error_at (token->location, "unknown type name %qE", token->value);