[PATCH 1/2] C: convert return type of lookup_name_fuzzy from tree to const char *

[David Malcolm <dmalcolm at redhat dot com>]

The followup patch implements lookup_name_fuzzy for the C++ frontend.
It's cleaner for that implementation to return a const char *, so this
patch updates the implementation in the C frontend to have the same
return type.

Successfully bootstrapped&regrtested on x86_64-pc-linux-gnu
(in combination with the followup patch).

OK for trunk?

gcc/c-family/ChangeLog:
	* c-common.h (lookup_name_fuzzy): Convert return type from tree to
	const char *.

gcc/c/ChangeLog:
	* c-decl.c (implicit_decl_warning): Update for conversion of
	return type of lookup_name_fuzzy to const char *.
	(undeclared_variable): Likewise.
	(lookup_name_fuzzy): Convert return type from tree to
	const char *.
	* c-parser.c (c_parser_declaration_or_fndef): Update for
	conversion of return type of lookup_name_fuzzy to const char *.
	(c_parser_parameter_declaration): Likewise.

gcc/ChangeLog:
	* gcc-rich-location.c
	(gcc_rich_location::add_fixit_misspelled_id): New overload, taking
	a const char *.
	* gcc-rich-location.h
	(gcc_rich_location::add_fixit_misspelled_id): Likewise.
---
 gcc/c-family/c-common.h |  2 +-
 gcc/c/c-decl.c          | 22 +++++++++++++---------
 gcc/c/c-parser.c        | 10 +++++-----
 gcc/gcc-rich-location.c | 13 +++++++++++++
 gcc/gcc-rich-location.h |  2 ++
 5 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 3ad5400..44d98d1 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -997,7 +997,7 @@ enum lookup_name_fuzzy_kind {
   /* Any name.  */
   FUZZY_LOOKUP_NAME
 };
-extern tree lookup_name_fuzzy (tree, enum lookup_name_fuzzy_kind);
+extern const char *lookup_name_fuzzy (tree, enum lookup_name_fuzzy_kind);
 
 extern bool vector_targets_convertible_p (const_tree t1, const_tree t2);
 extern bool vector_types_convertible_p (const_tree t1, const_tree t2, bool emit_lax_note);
diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
index 8b966fe..09f7f79 100644
--- a/gcc/c/c-decl.c
+++ b/gcc/c/c-decl.c
@@ -3088,7 +3088,7 @@ implicit_decl_warning (location_t loc, tree id, tree olddecl)
   if (warn_implicit_function_declaration)
     {
       bool warned;
-      tree hint = NULL_TREE;
+      const char *hint = NULL;
       if (!olddecl)
 	hint = lookup_name_fuzzy (id, FUZZY_LOOKUP_NAME);
 
@@ -3099,7 +3099,7 @@ implicit_decl_warning (location_t loc, tree id, tree olddecl)
 	    richloc.add_fixit_misspelled_id (loc, hint);
 	    warned = pedwarn_at_rich_loc
 	      (&richloc, OPT_Wimplicit_function_declaration,
-	       "implicit declaration of function %qE; did you mean %qE?",
+	       "implicit declaration of function %qE; did you mean %qs?",
 	       id, hint);
 	  }
 	else
@@ -3112,7 +3112,7 @@ implicit_decl_warning (location_t loc, tree id, tree olddecl)
 	    richloc.add_fixit_misspelled_id (loc, hint);
 	    warned = warning_at_rich_loc
 	      (&richloc, OPT_Wimplicit_function_declaration,
-	       G_("implicit declaration of function %qE;did you mean %qE?"),
+	       G_("implicit declaration of function %qE;did you mean %qs?"),
 	       id, hint);
 	  }
 	else
@@ -3433,14 +3433,14 @@ undeclared_variable (location_t loc, tree id)
 
   if (current_function_decl == 0)
     {
-      tree guessed_id = lookup_name_fuzzy (id, FUZZY_LOOKUP_NAME);
+      const char *guessed_id = lookup_name_fuzzy (id, FUZZY_LOOKUP_NAME);
       if (guessed_id)
 	{
 	  gcc_rich_location richloc (loc);
 	  richloc.add_fixit_misspelled_id (loc, guessed_id);
 	  error_at_rich_loc (&richloc,
 			     "%qE undeclared here (not in a function);"
-			     " did you mean %qE?",
+			     " did you mean %qs?",
 			     id, guessed_id);
 	}
       else
@@ -3451,7 +3451,7 @@ undeclared_variable (location_t loc, tree id)
     {
       if (!objc_diagnose_private_ivar (id))
 	{
-	  tree guessed_id = lookup_name_fuzzy (id, FUZZY_LOOKUP_NAME);
+	  const char *guessed_id = lookup_name_fuzzy (id, FUZZY_LOOKUP_NAME);
 	  if (guessed_id)
 	    {
 	      gcc_rich_location richloc (loc);
@@ -3459,7 +3459,7 @@ undeclared_variable (location_t loc, tree id)
 	      error_at_rich_loc
 		(&richloc,
 		 "%qE undeclared (first use in this function);"
-		 " did you mean %qE?",
+		 " did you mean %qs?",
 		 id, guessed_id);
 	    }
 	  else
@@ -4010,7 +4010,7 @@ find_closest_macro_cpp_cb (cpp_reader *, cpp_hashnode *hashnode,
    It also looks for start_typename keywords, to detect "singed" vs "signed"
    typos.  */
 
-tree
+const char *
 lookup_name_fuzzy (tree name, enum lookup_name_fuzzy_kind kind)
 {
   gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE);
@@ -4079,7 +4079,11 @@ lookup_name_fuzzy (tree name, enum lookup_name_fuzzy_kind kind)
 	}
     }
 
-  return bm.get_best_meaningful_candidate ();
+  tree best = bm.get_best_meaningful_candidate ();
+  if (best)
+    return IDENTIFIER_POINTER (best);
+  else
+    return NULL;
 }
 
 
diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index 7f491f1..0451120 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -1695,12 +1695,12 @@ c_parser_declaration_or_fndef (c_parser *parser, bool fndef_ok,
 	}
       else
 	{
-	  tree hint = lookup_name_fuzzy (name, FUZZY_LOOKUP_TYPENAME);
+	  const char *hint = lookup_name_fuzzy (name, FUZZY_LOOKUP_TYPENAME);
 	  if (hint)
 	    {
 	      richloc.add_fixit_misspelled_id (here, hint);
 	      error_at_rich_loc (&richloc,
-				 "unknown type name %qE; did you mean %qE?",
+				 "unknown type name %qE; did you mean %qs?",
 				 name, hint);
 	    }
 	  else
@@ -3850,14 +3850,14 @@ 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))
 	{
-	  tree hint = lookup_name_fuzzy (token->value, FUZZY_LOOKUP_TYPENAME);
+	  const char *hint = lookup_name_fuzzy (token->value,
+						FUZZY_LOOKUP_TYPENAME);
 	  if (hint)
 	    {
-	      gcc_assert (TREE_CODE (hint) == IDENTIFIER_NODE);
 	      gcc_rich_location richloc (token->location);
 	      richloc.add_fixit_misspelled_id (token->location, hint);
 	      error_at_rich_loc (&richloc,
-				 "unknown type name %qE; did you mean %qE?",
+				 "unknown type name %qE; did you mean %qs?",
 				 token->value, hint);
 	    }
 	  else
diff --git a/gcc/gcc-rich-location.c b/gcc/gcc-rich-location.c
index 15c0700..09475ff 100644
--- a/gcc/gcc-rich-location.c
+++ b/gcc/gcc-rich-location.c
@@ -74,3 +74,16 @@ gcc_rich_location::add_fixit_misspelled_id (location_t misspelled_token_loc,
     = get_range_from_loc (line_table, misspelled_token_loc);
   add_fixit_replace (misspelled_token_range, IDENTIFIER_POINTER (hint_id));
 }
+
+/* As above, but with a const char * for the suggested replacement.  */
+
+void
+gcc_rich_location::add_fixit_misspelled_id (location_t misspelled_token_loc,
+					    const char *hint)
+{
+  gcc_assert (hint);
+
+  source_range misspelled_token_range
+    = get_range_from_loc (line_table, misspelled_token_loc);
+  add_fixit_replace (misspelled_token_range, hint);
+}
diff --git a/gcc/gcc-rich-location.h b/gcc/gcc-rich-location.h
index 9c8a790..aa69b2e 100644
--- a/gcc/gcc-rich-location.h
+++ b/gcc/gcc-rich-location.h
@@ -45,6 +45,8 @@ class gcc_rich_location : public rich_location
 
   void add_fixit_misspelled_id (location_t misspelled_token_loc,
 				tree hint_id);
+  void add_fixit_misspelled_id (location_t misspelled_token_loc,
+				const char *hint);
 };
 
 #endif /* GCC_RICH_LOCATION_H */
-- 
1.8.5.3