Re: swap does not compile

[Alexandre Oliva <aoliva at redhat dot com>]

On Jan 12, 2004, Mark Mitchell <mark@codesourcery.com> wrote:

> On Mon, 2004-01-12 at 17:01, Alexandre Oliva wrote:
>> On Jan 12, 2004, Alexandre Oliva <aoliva@redhat.com> wrote:

> This is probably OK -- but it would be more reliable to just get the
> return value from cp_parser_nested_name_specifier_{,opt}.  They will
> return the qualifying scope for you. :-)

Unless it's the global namespace, as I found out :-)

> With that change, the patch is OK.

Here's the patch I'll check in as soon as my other patch (for PR
c++/13594) is in, since I've only tested this patch atop of that, and
since before that one there were libstdc++ regressions, it's probably
not a good idea to test without it anyway.

Index: gcc/cp/ChangeLog
from  Alexandre Oliva  <aoliva@redhat.com>

	PR c++/13659
	* name-lookup.c (validate_nonmember_using_decl): Take scope and
	name by value, instead of computing them.
	(do_local_using_decl, do_toplevel_using_decl): Add scope and name
	arguments.  Pass them to validate_nonmember_using_decl.
	* name-lookup.h (do_local_using_decl): Adjust.
	(do_toplevel_using_decl): Likewise.
	* parser.c (cp_parser_using_declaration): Likewise.
	* pt.c (tsubst_expr): Likewise.

Index: gcc/cp/name-lookup.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/name-lookup.c,v
retrieving revision 1.32
diff -u -p -r1.32 name-lookup.c
--- gcc/cp/name-lookup.c 9 Jan 2004 21:30:31 -0000 1.32
+++ gcc/cp/name-lookup.c 13 Jan 2004 13:48:10 -0000
@@ -2071,17 +2071,13 @@ push_overloaded_decl (tree decl, int fla
    being used, and the USING_DECL, or NULL_TREE on failure.  */
 
 static tree
-validate_nonmember_using_decl (tree decl, tree *scope, tree *name)
+validate_nonmember_using_decl (tree decl, tree scope, tree name)
 {
-  *scope = global_namespace;
-  *name = NULL_TREE;
-
   if (TREE_CODE (decl) == TEMPLATE_ID_EXPR)
     {
-      *name = TREE_OPERAND (decl, 0);
       /* 7.3.3/5
 	   A using-declaration shall not name a template-id.  */
-      error ("a using-declaration cannot specify a template-id.  Try `using %D'", *name);
+      error ("a using-declaration cannot specify a template-id.  Try `using %D'", name);
       return NULL_TREE;
     }
 
@@ -2104,25 +2100,17 @@ validate_nonmember_using_decl (tree decl
 
   my_friendly_assert (DECL_P (decl), 20020908);
 
-  if (TREE_CODE (decl) == CONST_DECL)
-    /* Enumeration constants to not have DECL_CONTEXT set.  */
-    *scope = TYPE_CONTEXT (TREE_TYPE (decl));
-  else
-    *scope = DECL_CONTEXT (decl);
-  if (!*scope)
-    *scope = global_namespace;
-
   /* [namespace.udecl]
        A using-declaration for a class member shall be a
        member-declaration.  */
-  if (TYPE_P (*scope))
+  if (TYPE_P (scope))
     {
-      error ("`%T' is not a namespace", *scope);
+      error ("`%T' is not a namespace", scope);
       return NULL_TREE;
     }
-  *name = DECL_NAME (decl);
+
   /* Make a USING_DECL.  */
-  return push_using_decl (*scope, *name);
+  return push_using_decl (scope, name);
 }
 
 /* Process local and global using-declarations.  */
@@ -2235,12 +2223,11 @@ do_nonmember_using_decl (tree scope, tre
 /* Process a using-declaration at function scope.  */
 
 void
-do_local_using_decl (tree decl)
+do_local_using_decl (tree decl, tree scope, tree name)
 {
-  tree scope, name;
   tree oldval, oldtype, newval, newtype;
 
-  decl = validate_nonmember_using_decl (decl, &scope, &name);
+  decl = validate_nonmember_using_decl (decl, scope, name);
   if (decl == NULL_TREE)
     return;
 
@@ -3248,13 +3235,12 @@ add_using_namespace (tree user, tree use
 /* Process a using-declaration not appearing in class or local scope.  */
 
 void
-do_toplevel_using_decl (tree decl)
+do_toplevel_using_decl (tree decl, tree scope, tree name)
 {
-  tree scope, name;
   tree oldval, oldtype, newval, newtype;
   cxx_binding *binding;
 
-  decl = validate_nonmember_using_decl (decl, &scope, &name);
+  decl = validate_nonmember_using_decl (decl, scope, name);
   if (decl == NULL_TREE)
     return;
   
Index: gcc/cp/name-lookup.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/name-lookup.h,v
retrieving revision 1.13
diff -u -p -r1.13 name-lookup.h
--- gcc/cp/name-lookup.h 2 Dec 2003 10:11:24 -0000 1.13
+++ gcc/cp/name-lookup.h 13 Jan 2004 13:48:10 -0000
@@ -301,8 +301,8 @@ extern tree current_decl_namespace (void
 extern void push_decl_namespace (tree);
 extern void pop_decl_namespace (void);
 extern void do_namespace_alias (tree, tree);
-extern void do_toplevel_using_decl (tree);
-extern void do_local_using_decl (tree);
+extern void do_toplevel_using_decl (tree, tree, tree);
+extern void do_local_using_decl (tree, tree, tree);
 extern tree do_class_using_decl (tree);
 extern void do_using_directive (tree);
 extern tree lookup_arg_dependent (tree, tree, tree);
Index: gcc/cp/parser.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/parser.c,v
retrieving revision 1.152
diff -u -p -r1.152 parser.c
--- gcc/cp/parser.c 13 Jan 2004 00:44:50 -0000 1.152
+++ gcc/cp/parser.c 13 Jan 2004 13:48:19 -0000
@@ -9392,6 +9392,7 @@ cp_parser_using_declaration (cp_parser* 
   tree decl;
   tree identifier;
   tree scope;
+  tree qscope;
 
   /* Look for the `using' keyword.  */
   cp_parser_require_keyword (parser, RID_USING, "`using'");
@@ -9416,18 +9417,20 @@ cp_parser_using_declaration (cp_parser* 
   /* If we saw `typename', or didn't see `::', then there must be a
      nested-name-specifier present.  */
   if (typename_p || !global_scope_p)
-    cp_parser_nested_name_specifier (parser, typename_p, 
-				     /*check_dependency_p=*/true,
-				     /*type_p=*/false,
-				     /*is_declaration=*/true);
+    qscope = cp_parser_nested_name_specifier (parser, typename_p, 
+					      /*check_dependency_p=*/true,
+					      /*type_p=*/false,
+					      /*is_declaration=*/true);
   /* Otherwise, we could be in either of the two productions.  In that
      case, treat the nested-name-specifier as optional.  */
   else
-    cp_parser_nested_name_specifier_opt (parser,
-					 /*typename_keyword_p=*/false,
-					 /*check_dependency_p=*/true,
-					 /*type_p=*/false,
-					 /*is_declaration=*/true);
+    qscope = cp_parser_nested_name_specifier_opt (parser,
+						  /*typename_keyword_p=*/false,
+						  /*check_dependency_p=*/true,
+						  /*type_p=*/false,
+						  /*is_declaration=*/true);
+  if (!qscope)
+    qscope = global_namespace;
 
   /* Parse the unqualified-id.  */
   identifier = cp_parser_unqualified_id (parser, 
@@ -9463,9 +9466,9 @@ cp_parser_using_declaration (cp_parser* 
 	  if (decl == error_mark_node)
 	    cp_parser_name_lookup_error (parser, identifier, decl, NULL);
 	  else if (scope)
-	    do_local_using_decl (decl);
+	    do_local_using_decl (decl, qscope, identifier);
 	  else
-	    do_toplevel_using_decl (decl);
+	    do_toplevel_using_decl (decl, qscope, identifier);
 	}
     }
 
Index: gcc/cp/pt.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/pt.c,v
retrieving revision 1.813
diff -u -p -r1.813 pt.c
--- gcc/cp/pt.c 13 Jan 2004 01:02:27 -0000 1.813
+++ gcc/cp/pt.c 13 Jan 2004 13:48:27 -0000
@@ -7695,7 +7695,7 @@ tsubst_expr (tree t, tree args, tsubst_f
 	    if (decl == error_mark_node)
 	      qualified_name_lookup_error (scope, name);
 	    else
-	      do_local_using_decl (decl);
+	      do_local_using_decl (decl, scope, name);
 	  }
 	else
 	  {
Index: gcc/testsuite/ChangeLog
from  Alexandre Oliva  <aoliva@redhat.com>

	PR c++/13659
	* g++.dg/lookup/strong-using-3.C: New.
	* g++.dg/lookup/using-10.C: New.

Index: gcc/testsuite/g++.dg/lookup/strong-using-3.C
===================================================================
RCS file: gcc/testsuite/g++.dg/lookup/strong-using-3.C
diff -N gcc/testsuite/g++.dg/lookup/strong-using-3.C
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ gcc/testsuite/g++.dg/lookup/strong-using-3.C 13 Jan 2004 13:48:39 -0000
@@ -0,0 +1,18 @@
+// PR c++/13659
+
+// { dg-do compile }
+
+namespace foo {
+  template <class T> void f(T, T);
+}
+namespace bar {
+  using namespace foo __attribute__((strong));
+  template <class T> void f(T);
+}
+
+int main() {
+  // Make sure both declarations are brought in.
+  using bar::f;
+  f(1);
+  f(1, 1);
+}
Index: gcc/testsuite/g++.dg/lookup/using-10.C
===================================================================
RCS file: gcc/testsuite/g++.dg/lookup/using-10.C
diff -N gcc/testsuite/g++.dg/lookup/using-10.C
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ gcc/testsuite/g++.dg/lookup/using-10.C 13 Jan 2004 13:48:39 -0000
@@ -0,0 +1,22 @@
+// PR c++/13659
+
+// { dg-do compile }
+
+namespace foo1 {
+  template <class T> void f(T);
+}
+namespace foo2 {
+  template <class T> void f(T, T);
+}
+namespace foo {
+  using namespace foo1;
+  using namespace foo2;
+}
+
+// Make sure we bring in both declarations.
+using foo::f;
+
+int main() {
+  f(1);
+  f(1, 1);
+}

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Happy GNU Year!                     oliva@{lsd.ic.unicamp.br, gnu.org}
Red Hat GCC Developer                 aoliva@{redhat.com, gcc.gnu.org}
Free Software Evangelist                Professional serial bug killer