[PATCH] c++: give suggestion on misspelled class name [PR116771]

[David Malcolm]

Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.

OK for trunk?

gcc/cp/ChangeLog:
	PR c++/116771
	* parser.cc (cp_parser_name_lookup_error): Provide suggestions for
	the case of complete failure where there is no scope.

gcc/testsuite/ChangeLog:
	PR c++/116771
	* g++.dg/spellcheck-pr116771.C: New test.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>
---
 gcc/cp/parser.cc                           | 16 +++++++++++++++-
 gcc/testsuite/g++.dg/spellcheck-pr116771.C |  9 +++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/spellcheck-pr116771.C

diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index ed10f58422ea..06ee36e6727c 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -3399,7 +3399,21 @@ cp_parser_name_lookup_error (cp_parser* parser,
 	error_at (location, "%<%T::%E%> has not been declared",
 		  parser->object_scope, name);
       else
-	error_at (location, "%qE has not been declared", name);
+	{
+	  auto_diagnostic_group d;
+	  name_hint hint
+	    = lookup_name_fuzzy (name, FUZZY_LOOKUP_TYPENAME, location);
+	  if (const char *suggestion = hint.suggestion ())
+	    {
+	      gcc_rich_location richloc (location);
+	      richloc.add_fixit_replace (suggestion);
+	      error_at (&richloc,
+			"%qE has not been declared; did you mean %qs?",
+			name, suggestion);
+	    }
+	  else
+	    error_at (location, "%qE has not been declared", name);
+	}
     }
   else if (parser->scope && parser->scope != global_namespace)
     {
diff --git a/gcc/testsuite/g++.dg/spellcheck-pr116771.C b/gcc/testsuite/g++.dg/spellcheck-pr116771.C
new file mode 100644
index 000000000000..fd8bd6d46cbd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/spellcheck-pr116771.C
@@ -0,0 +1,9 @@
+class layout_printer
+{
+    void print_newline ();
+};
+
+void
+layout_pirnter::print_newline () // { dg-error "'layout_pirnter' has not been declared; did you mean 'layout_printer'" }
+{
+}
-- 
2.26.3