C++ FE: handle misspelled identifiers and typenames

gcc/cp/ChangeLog:
	PR c/70339
	PR c/71858
	* name-lookup.c: Include gcc-rich-location.h, spellcheck-tree.h,
	and parser.h.
	(suggest_alternatives_for): If no candidates are found, try
	lookup_name_fuzzy and report if if finds a suggestion.
	(consider_binding_level): New function.
	(lookup_name_fuzzy) New function.
	* parser.c: Include gcc-rich-location.h.
	(cp_lexer_next_token_is_decl_specifier_keyword): Move most of
	logic into...
	(cp_keyword_starts_decl_specifier_p): ...this new function.
	(cp_parser_diagnose_invalid_type_name): When issuing
	"does not name a type" errors, attempt to make a suggestion using
	lookup_name_fuzzy.
	* parser.h (cp_keyword_starts_decl_specifier_p): New prototype.
	* search.c (lookup_field_fuzzy_info::fuzzy_lookup_field): Reject
	types that are not CLASS_TYPE_P, rather than rejecting individual
	tree codes.

gcc/testsuite/ChangeLog:
	PR c/70339
	PR c/71858
	* g++.dg/spellcheck-identifiers.C: New test case, based on
	gcc.dg/spellcheck-identifiers.c.
	* g++.dg/spellcheck-identifiers-2.C: New test case, based on
	gcc.dg/spellcheck-identifiers-2.c.
	* g++.dg/spellcheck-typenames.C: New test case, based on
	gcc.dg/spellcheck-typenames.c

From-SVN: r238538

1 files changed, 32 insertions, 11 deletions

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 84dad48..8fceaed 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -40,6 +40,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "c-family/c-indentation.h"
 #include "context.h"
 #include "cp-cilkplus.h"
+#include "gcc-rich-location.h"
 
 
 /* The lexer.  */
@@ -937,15 +938,12 @@ cp_lexer_next_token_is_not_keyword (cp_lexer* lexer, enum rid keyword)
   return cp_lexer_peek_token (lexer)->keyword != keyword;
 }
 
-/* Return true if the next token is a keyword for a decl-specifier.  */
+/* Return true if KEYWORD can start a decl-specifier.  */
 
-static bool
-cp_lexer_next_token_is_decl_specifier_keyword (cp_lexer *lexer)
+bool
+cp_keyword_starts_decl_specifier_p (enum rid keyword)
 {
-  cp_token *token;
-
-  token = cp_lexer_peek_token (lexer);
-  switch (token->keyword) 
+  switch (keyword)
     {
       /* auto specifier: storage-class-specifier in C++,
          simple-type-specifier in C++0x.  */
@@ -985,14 +983,25 @@ cp_lexer_next_token_is_decl_specifier_keyword (cp_lexer *lexer)
       return true;
 
     default:
-      if (token->keyword >= RID_FIRST_INT_N
-	  && token->keyword < RID_FIRST_INT_N + NUM_INT_N_ENTS
-	  && int_n_enabled_p[token->keyword - RID_FIRST_INT_N])
+      if (keyword >= RID_FIRST_INT_N
+	  && keyword < RID_FIRST_INT_N + NUM_INT_N_ENTS
+	  && int_n_enabled_p[keyword - RID_FIRST_INT_N])
 	return true;
       return false;
     }
 }
 
+/* Return true if the next token is a keyword for a decl-specifier.  */
+
+static bool
+cp_lexer_next_token_is_decl_specifier_keyword (cp_lexer *lexer)
+{
+  cp_token *token;
+
+  token = cp_lexer_peek_token (lexer);
+  return cp_keyword_starts_decl_specifier_p (token->keyword);
+}
+
 /* Returns TRUE iff the token T begins a decltype type.  */
 
 static bool
@@ -3154,7 +3163,19 @@ cp_parser_diagnose_invalid_type_name (cp_parser *parser, tree id,
   else if (!parser->scope)
     {
       /* Issue an error message.  */
-      error_at (location, "%qE does not name a type", id);
+      const char *suggestion = NULL;
+      if (TREE_CODE (id) == IDENTIFIER_NODE)
+        suggestion = lookup_name_fuzzy (id, FUZZY_LOOKUP_TYPENAME);
+      if (suggestion)
+	{
+	  gcc_rich_location richloc (location);
+	  richloc.add_fixit_misspelled_id (location, suggestion);
+	  error_at_rich_loc (&richloc,
+			     "%qE does not name a type; did you mean %qs?",
+			     id, suggestion);
+	}
+      else
+	error_at (location, "%qE does not name a type", id);
       /* If we're in a template class, it's possible that the user was
 	 referring to a type from a base class.  For example: