re PR c++/20293 (Wrong diagnostic for ambiguous access)

	PR c++/20293
	* cxx-pretty-print.c (pp_cxx_statement): Print qualifying scopes
	for namespaces.
	(pp_cxx_original_namespace_definition): Likewise.
	* name-lookup.c (ambiguous_decl): Don't issue error messages;
	instead return lists of ambiguous candidates.
	(select_decl): Handle ambiguous namespace lookups.
	* parser.c (cp_token): Add ambiguous_p.
	(cp_lexer_get_preprocessor_token): Set it.
	(cp_parser_diagnose_invalid_type_name): Avoid duplicate messages
	when a qualified name uses an invalid scope. 
	(cp_parser_primary_expression): Print ambiguous candidates.
	(cp_parser_type_parameter): Adjust comment to reflect new
	parameter name for cp_parser_lookup_name.
	(cp_parser_template_argument): Likewise.
	(cp_parser_elaborated_type_specifier): Likewise.
	(cp_parser_namespace_name): Likewise.
	(cp_parser_class_name): Print ambiguous candidates.
	(cp_parser_lookup_name): Rename ambiguous_p parameter to
	ambiguous_decls.  Use it to return a list of ambiguous candiates
	when a lookup is ambiguous.
	(cp_parser_lookup_name_simple): Adjust comment to reflect new
	parameter name for cp_parser_lookup_name.
	
	PR c++/20293
	* g++.dg/parse/ambig4.C: New test.
	* g++.dg/tc1/dr101.C: Adjust error markers.
	* g++.dg/lookup/strong-using-2.C: Likewise.
	* g++.dg/lookup/ambig5.C: Likewise.
	* g++.dg/lookup/ambig4.C: Likewise.
	* g++.dg/parse/crash22.C: Likewise.

From-SVN: r106879

gcc/cp/ChangeLog

+2005-11-13  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/20293
+	* cxx-pretty-print.c (pp_cxx_statement): Print qualifying scopes
+	for namespaces.
+	(pp_cxx_original_namespace_definition): Likewise.
+	* name-lookup.c (ambiguous_decl): Don't issue error messages;
+	instead return lists of ambiguous candidates.
+	(select_decl): Handle ambiguous namespace lookups.
+	* parser.c (cp_token): Add ambiguous_p.
+	(cp_lexer_get_preprocessor_token): Set it.
+	(cp_parser_diagnose_invalid_type_name): Avoid duplicate messages
+	when a qualified name uses an invalid scope. 
+	(cp_parser_primary_expression): Print ambiguous candidates.
+	(cp_parser_type_parameter): Adjust comment to reflect new
+	parameter name for cp_parser_lookup_name.
+	(cp_parser_template_argument): Likewise.
+	(cp_parser_elaborated_type_specifier): Likewise.
+	(cp_parser_namespace_name): Likewise.
+	(cp_parser_class_name): Print ambiguous candidates.
+	(cp_parser_lookup_name): Rename ambiguous_p parameter to
+	ambiguous_decls.  Use it to return a list of ambiguous candiates
+	when a lookup is ambiguous.
+	(cp_parser_lookup_name_simple): Adjust comment to reflect new
+	parameter name for cp_parser_lookup_name.
+	
 2005-11-12  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/24780

gcc/cp/cxx-pretty-print.c

@@ -1514,6 +1514,8 @@ pp_cxx_statement (cxx_pretty_printer *pp, tree t)
     case USING_STMT:
       pp_cxx_identifier (pp, "using");
       pp_cxx_identifier (pp, "namespace");
+      if (DECL_CONTEXT (t))
+	pp_cxx_nested_name_specifier (pp, DECL_CONTEXT (t));
       pp_cxx_qualified_id (pp, USING_STMT_NAMESPACE (t));
       break;
 
@@ -1701,6 +1703,8 @@ static void
 pp_cxx_original_namespace_definition (cxx_pretty_printer *pp, tree t)
 {
   pp_cxx_identifier (pp, "namespace");
+  if (DECL_CONTEXT (t))
+    pp_cxx_nested_name_specifier (pp, DECL_CONTEXT (t));
   if (DECL_NAME (t))
     pp_cxx_unqualified_id (pp, t);
   pp_cxx_whitespace (pp);
@@ -1723,10 +1727,15 @@ static void
 pp_cxx_namespace_alias_definition (cxx_pretty_printer *pp, tree t)
 {
   pp_cxx_identifier (pp, "namespace");
+  if (DECL_CONTEXT (t))
+    pp_cxx_nested_name_specifier (pp, DECL_CONTEXT (t));
   pp_cxx_unqualified_id (pp, t);
   pp_cxx_whitespace (pp);
   pp_equal (pp);
   pp_cxx_whitespace (pp);
+  if (DECL_CONTEXT (DECL_NAMESPACE_ALIAS (t)))
+    pp_cxx_nested_name_specifier (pp, 
+				  DECL_CONTEXT (DECL_NAMESPACE_ALIAS (t)));
   pp_cxx_qualified_id (pp, DECL_NAMESPACE_ALIAS (t));
   pp_cxx_semicolon (pp);
 }

gcc/cp/name-lookup.c

@@ -3400,20 +3400,9 @@ ambiguous_decl (tree name, struct scope_binding *old, cxx_binding *new,
 	old->value = merge_functions (old->value, val);
       else
 	{
-	  /* Some declarations are functions, some are not.  */
-	  if (flags & LOOKUP_COMPLAIN)
-	    {
-	      /* If we've already given this error for this lookup,
-		 old->value is error_mark_node, so let's not
-		 repeat ourselves.  */
-	      if (old->value != error_mark_node)
-		{
-		  error ("use of %qD is ambiguous", name);
-		  error ("  first declared as %q+#D here", old->value);
-		}
-	      error ("  also declared as %q+#D here", val);
-	    }
-	  old->value = error_mark_node;
+	  old->value = tree_cons (NULL_TREE, old->value,
+				  build_tree_list (NULL_TREE, new->value));
+	  TREE_TYPE (old->value) = error_mark_node;
 	}
     }
   /* ... and copy the type.  */
@@ -3609,7 +3598,8 @@ select_decl (const struct scope_binding *binding, int flags)
   if (LOOKUP_NAMESPACES_ONLY (flags))
     {
       /* We are not interested in types.  */
-      if (val && TREE_CODE (val) == NAMESPACE_DECL)
+      if (val && (TREE_CODE (val) == NAMESPACE_DECL
+		  || TREE_CODE (val) == TREE_LIST))
 	POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, val);
       POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, NULL_TREE);
     }

gcc/testsuite/ChangeLog

+2005-11-13  Mark Mitchell  <mark@codesourcery.com>
+
+	PR c++/20293
+	* g++.dg/parse/ambig4.C: New test.
+	* g++.dg/tc1/dr101.C: Adjust error markers.
+	* g++.dg/lookup/strong-using-2.C: Likewise.
+	* g++.dg/lookup/ambig5.C: Likewise.
+	* g++.dg/lookup/ambig4.C: Likewise.
+	* g++.dg/parse/crash22.C: Likewise.
+
 2005-11-14  Hans-Peter Nilsson  <hp@axis.com>
 
 	* gcc.dg/pr19340.c: Skip for mmix-*-* and cris-*-*.

gcc/testsuite/g++.dg/lookup/ambig4.C

@@ -4,11 +4,11 @@
 
 namespace N
 {
-  int i;            // { dg-error "declared" }
+  int i;            // { dg-error "i" }
 }
 
-int i;              // { dg-error "declared" }
+int i;              // { dg-error "i" }
 
 using namespace N;
 
-void foo() { i; }   // { dg-error "in this scope|ambiguous" }
+void foo() { i; }   // { dg-error "ambiguous" }

gcc/testsuite/g++.dg/lookup/ambig5.C

@@ -4,10 +4,10 @@
 
 namespace N
 {
-  namespace M {}    // { dg-error "declared" }
+  namespace M {}    // { dg-error "M" }
 }
 
-namespace M {}      // { dg-error "declared" }
+namespace M {}      // { dg-error "M" }
 
 using namespace N;
 using namespace M;  // { dg-error "namespace-name|ambiguous" }

gcc/testsuite/g++.dg/lookup/strong-using-2.C

@@ -3,10 +3,10 @@
 // { dg-do compile }
 
 namespace foo_impl {
-  class T; // { dg-error "first declared" "" }
+  class T; // { dg-error "T" "" }
 }
 namespace bar_impl {
-  class T; // { dg-error "also declared" "" }
+  class T; // { dg-error "T" "" }
 }
 namespace foo {
   using namespace foo_impl __attribute__((strong));

gcc/testsuite/g++.dg/parse/ambig4.C

+// PR c++/20293
+
+namespace hide { // { dg-error "hide" }
+  int k;
+}
+
+namespace {
+  int i; 
+  namespace hide { // { dg-error "hide" }
+    int j; 
+  }
+}
+
+void F(int) {}
+
+int main() {
+  F(hide::j); // { dg-error "ambiguous" }
+}

gcc/testsuite/g++.dg/parse/crash22.C

@@ -4,17 +4,17 @@
 // PR 19030: ICE
 // Origin: Volker Reichelt <reichelt@gcc.gnu.org>
 
-struct A;
+struct A; // { dg-error "A" }
 
 namespace N
 {
-  struct A;
+  struct A; // { dg-error "A" }
 }
 
 using namespace N;
 
-int A::i; // { dg-error "not been declared|declared here" "" }
-int A::i; // { dg-error "not been declared|redefinition of" "" }
+int A::i; // { dg-error "ambiguous|declared here" "" }
+int A::i; // { dg-error "ambiguous|redefinition of" "" }
 
 namespace N
 {

gcc/testsuite/g++.dg/tc1/dr101.C

@@ -17,10 +17,10 @@ namespace Test1 {
 
 namespace Test2 {
 
-  typedef unsigned int X;   // { dg-bogus "declared" "" { xfail *-*-* } }
+  typedef unsigned int X;   // { dg-bogus "X" "" { xfail *-*-* } }
   extern "C" int f2();
   namespace N {
-    typedef unsigned int X; // { dg-bogus "declared" "" { xfail *-*-* } }
+    typedef unsigned int X; // { dg-bogus "X" "" { xfail *-*-* } }
     extern "C" int f2();
   }
   using namespace N;