Properly handle C2x attributes on types
diff mbox series

Message ID alpine.DEB.2.21.1911220241270.31284@digraph.polyomino.org.uk
State New
Headers show
Series
  • Properly handle C2x attributes on types
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Commit Message

Joseph Myers Nov. 22, 2019, 2:42 a.m. UTC
attribs.c has code to ignore all scoped attributes appertaining to
types except when they are part of the definition of that type.

I think the premise of that code is incorrect, and its presence is a
bug; such attributes are clearly valid in both C and C++, which
explicitly specify that attributes in certain syntactic positions
appertain to a particular type, only for that use of that type and not
for other uses of the same type specifiers without that attribute
specified, and while the standard attributes in C2x aren't relevant in
such contexts, some gnu:: attributes certainly are.  Where some
attributes are invalid on some types in such contexts, that's a matter
for the individual attribute handlers to diagnose (or the front end if
the requirements on a standard attribute in the standard are more
strict than those of a handler shared with a GNU attribute).

Thus, this patch removes the bogus code to allow such attributes to be
used.  Doing so (and adding tests for attributes in such positions)
shows up that the logic in the C front end for creating the
c_declarator structures for such attributes put them in the wrong
place relative to the structures for function and array types, and the
logic for postfix attributes on a list of declaration specifiers
failed to handle some cases, so those bugs are also fixed in this
patch.

Bootstrapped with no regressions for x86_64-pc-linux-gnu.  OK to commit 
(attribs.c and C++ testsuite changes)?

gcc:
2019-11-22  Joseph Myers  <joseph@codesourcery.com>

	* attribs.c (decl_attributes): Do not ignore C++11 attributes on
	types.

gcc/c:
2019-11-22  Joseph Myers  <joseph@codesourcery.com>

	* c-tree.h (struct c_declarator): Use a structure for id member.
	* c-decl.c (grokdeclarator): Extract attributes from cdk_id
	declarators at the start, not when handling individual declarators
	later.  Use u.id.id instead of u.id.
	(grokfield): Use u.id.id instead of u.id.
	(build_id_declarator): Set u.id.id and u.id.attrs.
	(finish_declspecs): Handle postfix attributes in case of typedef
	name or typeof used.
	* c-parser.c (c_parser_direct_declarator)
	(c_parser_direct_declarator_inner): Place declarator for
	attributes inside that for function or array, not outside.  Set
	u.id.attrs for identifiers.
	(c_parser_parameter_declaration): Use u.id.id instead of u.id.
	* gimple-parser.c (c_parser_gimple_declaration): Use u.id.id
	instead of u.id.

gcc/testsuite:
2019-11-22  Joseph Myers  <joseph@codesourcery.com>

	* gcc.dg/gnu2x-attrs-1.c: Do not expect message about attributes
	appertaining to types.
	* gcc.dg/gnu2x-attrs-2.c: New test.
	* g++.dg/cpp0x/gen-attrs-1.C, g++.dg/cpp0x/gen-attrs-22.C,
	g++.dg/cpp0x/gen-attrs-4.C, g++.dg/cpp0x/lambda/lambda-attr1.C:
	Update expected diagnostics.

Comments

Jeff Law Nov. 23, 2019, 4:56 p.m. UTC | #1
On 11/21/19 7:42 PM, Joseph Myers wrote:
> attribs.c has code to ignore all scoped attributes appertaining to
> types except when they are part of the definition of that type.
> 
> I think the premise of that code is incorrect, and its presence is a
> bug; such attributes are clearly valid in both C and C++, which
> explicitly specify that attributes in certain syntactic positions
> appertain to a particular type, only for that use of that type and not
> for other uses of the same type specifiers without that attribute
> specified, and while the standard attributes in C2x aren't relevant in
> such contexts, some gnu:: attributes certainly are.  Where some
> attributes are invalid on some types in such contexts, that's a matter
> for the individual attribute handlers to diagnose (or the front end if
> the requirements on a standard attribute in the standard are more
> strict than those of a handler shared with a GNU attribute).
> 
> Thus, this patch removes the bogus code to allow such attributes to be
> used.  Doing so (and adding tests for attributes in such positions)
> shows up that the logic in the C front end for creating the
> c_declarator structures for such attributes put them in the wrong
> place relative to the structures for function and array types, and the
> logic for postfix attributes on a list of declaration specifiers
> failed to handle some cases, so those bugs are also fixed in this
> patch.
> 
> Bootstrapped with no regressions for x86_64-pc-linux-gnu.  OK to commit 
> (attribs.c and C++ testsuite changes)?
> 
> gcc:
> 2019-11-22  Joseph Myers  <joseph@codesourcery.com>
> 
> 	* attribs.c (decl_attributes): Do not ignore C++11 attributes on
> 	types.
> 
> gcc/c:
> 2019-11-22  Joseph Myers  <joseph@codesourcery.com>
> 
> 	* c-tree.h (struct c_declarator): Use a structure for id member.
> 	* c-decl.c (grokdeclarator): Extract attributes from cdk_id
> 	declarators at the start, not when handling individual declarators
> 	later.  Use u.id.id instead of u.id.
> 	(grokfield): Use u.id.id instead of u.id.
> 	(build_id_declarator): Set u.id.id and u.id.attrs.
> 	(finish_declspecs): Handle postfix attributes in case of typedef
> 	name or typeof used.
> 	* c-parser.c (c_parser_direct_declarator)
> 	(c_parser_direct_declarator_inner): Place declarator for
> 	attributes inside that for function or array, not outside.  Set
> 	u.id.attrs for identifiers.
> 	(c_parser_parameter_declaration): Use u.id.id instead of u.id.
> 	* gimple-parser.c (c_parser_gimple_declaration): Use u.id.id
> 	instead of u.id.
> 
> gcc/testsuite:
> 2019-11-22  Joseph Myers  <joseph@codesourcery.com>
> 
> 	* gcc.dg/gnu2x-attrs-1.c: Do not expect message about attributes
> 	appertaining to types.
> 	* gcc.dg/gnu2x-attrs-2.c: New test.
> 	* g++.dg/cpp0x/gen-attrs-1.C, g++.dg/cpp0x/gen-attrs-22.C,
> 	g++.dg/cpp0x/gen-attrs-4.C, g++.dg/cpp0x/lambda/lambda-attr1.C:
> 	Update expected diagnostics.
OK
jeff
Rainer Orth Nov. 25, 2019, 8:26 p.m. UTC | #2
Hi Joseph,

> attribs.c has code to ignore all scoped attributes appertaining to
> types except when they are part of the definition of that type.
>
> I think the premise of that code is incorrect, and its presence is a
> bug; such attributes are clearly valid in both C and C++, which
> explicitly specify that attributes in certain syntactic positions
> appertain to a particular type, only for that use of that type and not
> for other uses of the same type specifiers without that attribute
> specified, and while the standard attributes in C2x aren't relevant in
> such contexts, some gnu:: attributes certainly are.  Where some
> attributes are invalid on some types in such contexts, that's a matter
> for the individual attribute handlers to diagnose (or the front end if
> the requirements on a standard attribute in the standard are more
> strict than those of a handler shared with a GNU attribute).
>
> Thus, this patch removes the bogus code to allow such attributes to be
> used.  Doing so (and adding tests for attributes in such positions)
> shows up that the logic in the C front end for creating the
> c_declarator structures for such attributes put them in the wrong
> place relative to the structures for function and array types, and the
> logic for postfix attributes on a list of declaration specifiers
> failed to handle some cases, so those bugs are also fixed in this
> patch.
>
> Bootstrapped with no regressions for x86_64-pc-linux-gnu.  OK to commit 
> (attribs.c and C++ testsuite changes)?

it seems you missed updating a couple of testcases that are ia32-only:

+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++14  (test for warnings, line 12)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++14  (test for warnings, line 13)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++14  (test for warnings, line 20)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++14  (test for warnings, line 21)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++14 (test for excess errors)

Excess errors:
/vol/gcc/src/hg/trunk/local/gcc/testsuite/g++.dg/cpp0x/gen-attrs-36.C:12:50: warning: 'stdcall' attribute only applies to function types [-Wattributes]

+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++17  (test for warnings, line 12)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++17  (test for warnings, line 13)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++17  (test for warnings, line 20)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++17  (test for warnings, line 21)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++17 (test for excess errors)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++2a  (test for warnings, line 12)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++2a  (test for warnings, line 13)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++2a  (test for warnings, line 20)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++2a  (test for warnings, line 21)
+FAIL: g++.dg/cpp0x/gen-attrs-36.C  -std=gnu++2a (test for excess errors)
+FAIL: g++.dg/cpp0x/gen-attrs-37.C  -std=gnu++14  (test for warnings, line 13)
+FAIL: g++.dg/cpp0x/gen-attrs-37.C  -std=gnu++17  (test for warnings, line 13)
+FAIL: g++.dg/cpp0x/gen-attrs-37.C  -std=gnu++2a  (test for warnings, line 13)
+FAIL: g++.dg/cpp0x/gen-attrs-8.C  -std=gnu++14  (test for warnings, line 6)
+FAIL: g++.dg/cpp0x/gen-attrs-8.C  -std=gnu++14 (test for excess errors)
+FAIL: g++.dg/cpp0x/gen-attrs-8.C  -std=gnu++17  (test for warnings, line 6)
+FAIL: g++.dg/cpp0x/gen-attrs-8.C  -std=gnu++17 (test for excess errors)
+FAIL: g++.dg/cpp0x/gen-attrs-8.C  -std=gnu++2a  (test for warnings, line 6)
+FAIL: g++.dg/cpp0x/gen-attrs-8.C  -std=gnu++2a (test for excess errors)

	Rainer
Joseph Myers Nov. 26, 2019, 12:55 a.m. UTC | #3
On Mon, 25 Nov 2019, Rainer Orth wrote:

> it seems you missed updating a couple of testcases that are ia32-only:

I think it's unavoidable that such target-specific testcases need updating 
by someone testing on the target in question.
Rainer Orth Nov. 27, 2019, 11:23 a.m. UTC | #4
Hi Joseph,

> On Mon, 25 Nov 2019, Rainer Orth wrote:
>
>> it seems you missed updating a couple of testcases that are ia32-only:
>
> I think it's unavoidable that such target-specific testcases need updating 
> by someone testing on the target in question.

like so?  Tested on i386-pc-solaris2.11.

	Rainer
Jeff Law Dec. 7, 2019, 4:36 p.m. UTC | #5
On Wed, 2019-11-27 at 12:23 +0100, Rainer Orth wrote:
> Hi Joseph,
> 
> > On Mon, 25 Nov 2019, Rainer Orth wrote:
> > 
> > > it seems you missed updating a couple of testcases that are ia32-
> > > only:
> > 
> > I think it's unavoidable that such target-specific testcases need
> > updating 
> > by someone testing on the target in question.
> 
> like so?  Tested on i386-pc-solaris2.11.
> 
> 	Rainer
> 
> 2019-11-26  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
> 
>         * g++.dg/cpp0x/gen-attrs-36.C: Update expected diagnostics.
>         * g++.dg/cpp0x/gen-attrs-37.C: Likewise.
>         * g++.dg/cpp0x/gen-attrs-8.C: Likewise.
OK
jeff

Patch
diff mbox series

Index: gcc/attribs.c
===================================================================
--- gcc/attribs.c	(revision 278604)
+++ gcc/attribs.c	(working copy)
@@ -583,21 +583,6 @@  decl_attributes (tree *node, tree attributes, int
 	}
       gcc_assert (is_attribute_p (spec->name, name));
 
-      if (TYPE_P (*node)
-	  && cxx11_attr_p
-	  && !(flags & ATTR_FLAG_TYPE_IN_PLACE))
-	{
-	  /* This is a c++11 attribute that appertains to a
-	     type-specifier, outside of the definition of, a class
-	     type.  Ignore it.  */
-	  auto_diagnostic_group d;
-	  if (warning (OPT_Wattributes, "attribute ignored"))
-	    inform (input_location,
-		    "an attribute that appertains to a type-specifier "
-		    "is ignored");
-	  continue;
-	}
-
       if (spec->decl_required && !DECL_P (*anode))
 	{
 	  if (flags & ((int) ATTR_FLAG_DECL_NEXT
Index: gcc/c/c-decl.c
===================================================================
--- gcc/c/c-decl.c	(revision 278604)
+++ gcc/c/c-decl.c	(working copy)
@@ -5951,6 +5951,7 @@  grokdeclarator (const struct c_declarator *declara
   bool array_parm_static = false;
   bool array_parm_vla_unspec_p = false;
   tree returned_attrs = NULL_TREE;
+  tree decl_id_attrs = NULL_TREE;
   bool bitfield = width != NULL;
   tree element_type;
   tree orig_qual_type = NULL;
@@ -6013,8 +6014,9 @@  grokdeclarator (const struct c_declarator *declara
 
 	case cdk_id:
 	  loc = decl->id_loc;
-	  if (decl->u.id)
-	    name = decl->u.id;
+	  if (decl->u.id.id)
+	    name = decl->u.id.id;
+	  decl_id_attrs = decl->u.id.attrs;
 	  if (first_non_attr_kind == cdk_attrs)
 	    first_non_attr_kind = decl->kind;
 	  decl = 0;
@@ -6300,7 +6302,9 @@  grokdeclarator (const struct c_declarator *declara
 	       Standard attributes applied to a function or array
 	       declarator apply exactly to that type; standard
 	       attributes applied to the identifier apply to the
-	       declaration rather than to the type.  */
+	       declaration rather than to the type, and are specified
+	       using a cdk_id declarator rather than using
+	       cdk_attrs.  */
 	    inner_decl = declarator;
 	    while (inner_decl->kind == cdk_attrs)
 	      inner_decl = inner_decl->declarator;
@@ -6313,16 +6317,10 @@  grokdeclarator (const struct c_declarator *declara
 		else if (inner_decl->kind == cdk_array)
 		  attr_flags |= (int) ATTR_FLAG_ARRAY_NEXT;
 	      }
-	    if (cxx11_attribute_p (attrs) && inner_decl->kind == cdk_id)
-	      returned_attrs = chainon (returned_attrs, attrs);
-	    else
-	      {
-		attrs = c_warn_type_attributes (attrs);
-		returned_attrs = decl_attributes (&type,
-						  chainon (returned_attrs,
-							   attrs),
-						  attr_flags);
-	      }
+	    attrs = c_warn_type_attributes (attrs);
+	    returned_attrs = decl_attributes (&type,
+					      chainon (returned_attrs, attrs),
+					      attr_flags);
 	    break;
 	  }
 	case cdk_array:
@@ -6883,6 +6881,7 @@  grokdeclarator (const struct c_declarator *declara
 	}
     }
   *decl_attrs = chainon (returned_attrs, *decl_attrs);
+  *decl_attrs = chainon (decl_id_attrs, *decl_attrs);
 
   /* Now TYPE has the actual type, apart from any qualifiers in
      TYPE_QUALS.  */
@@ -7017,7 +7016,7 @@  grokdeclarator (const struct c_declarator *declara
 	type = c_build_qualified_type (type, type_quals, orig_qual_type,
 				       orig_qual_indirect);
       decl = build_decl (declarator->id_loc,
-			 TYPE_DECL, declarator->u.id, type);
+			 TYPE_DECL, declarator->u.id.id, type);
       if (declspecs->explicit_signed_p)
 	C_TYPEDEF_EXPLICITLY_SIGNED (decl) = 1;
       if (declspecs->inline_p)
@@ -7025,9 +7024,9 @@  grokdeclarator (const struct c_declarator *declara
       if (declspecs->noreturn_p)
 	pedwarn (loc, 0,"typedef %q+D declared %<_Noreturn%>", decl);
 
-      if (warn_cxx_compat && declarator->u.id != NULL_TREE)
+      if (warn_cxx_compat && declarator->u.id.id != NULL_TREE)
 	{
-	  struct c_binding *b = I_TAG_BINDING (declarator->u.id);
+	  struct c_binding *b = I_TAG_BINDING (declarator->u.id.id);
 
 	  if (b != NULL
 	      && b->decl != NULL_TREE
@@ -7159,7 +7158,7 @@  grokdeclarator (const struct c_declarator *declara
 	  type = c_build_qualified_type (type, type_quals);
 
 	decl = build_decl (declarator->id_loc,
-			   PARM_DECL, declarator->u.id, type);
+			   PARM_DECL, declarator->u.id.id, type);
 	if (size_varies)
 	  C_DECL_VARIABLE_SIZE (decl) = 1;
 	C_ARRAY_PARAMETER (decl) = array_parameter_p;
@@ -7221,9 +7220,9 @@  grokdeclarator (const struct c_declarator *declara
 	type = c_build_qualified_type (type, type_quals, orig_qual_type,
 				       orig_qual_indirect);
 	decl = build_decl (declarator->id_loc,
-			   FIELD_DECL, declarator->u.id, type);
+			   FIELD_DECL, declarator->u.id.id, type);
 	DECL_NONADDRESSABLE_P (decl) = bitfield;
-	if (bitfield && !declarator->u.id)
+	if (bitfield && !declarator->u.id.id)
 	  {
 	    TREE_NO_WARNING (decl) = 1;
 	    DECL_PADDING_P (decl) = 1;
@@ -7259,7 +7258,7 @@  grokdeclarator (const struct c_declarator *declara
 	  }
 
 	decl = build_decl (declarator->id_loc,
-			   FUNCTION_DECL, declarator->u.id, type);
+			   FUNCTION_DECL, declarator->u.id.id, type);
 	decl = build_decl_attribute_variant (decl, decl_attr);
 
 	if (type_quals & TYPE_QUAL_ATOMIC)
@@ -7304,7 +7303,7 @@  grokdeclarator (const struct c_declarator *declara
 
 	/* Record presence of `inline' and `_Noreturn', if it is
 	   reasonable.  */
-	if (flag_hosted && MAIN_NAME_P (declarator->u.id))
+	if (flag_hosted && MAIN_NAME_P (declarator->u.id.id))
 	  {
 	    if (declspecs->inline_p)
 	      pedwarn (loc, 0, "cannot inline function %<main%>");
@@ -7345,8 +7344,8 @@  grokdeclarator (const struct c_declarator *declara
 	   the 'extern' declaration is taken to refer to that decl.) */
 	if (extern_ref && current_scope != file_scope)
 	  {
-	    tree global_decl  = identifier_global_value (declarator->u.id);
-	    tree visible_decl = lookup_name (declarator->u.id);
+	    tree global_decl  = identifier_global_value (declarator->u.id.id);
+	    tree visible_decl = lookup_name (declarator->u.id.id);
 
 	    if (global_decl
 		&& global_decl != visible_decl
@@ -7357,7 +7356,7 @@  grokdeclarator (const struct c_declarator *declara
 	  }
 
 	decl = build_decl (declarator->id_loc,
-			   VAR_DECL, declarator->u.id, type);
+			   VAR_DECL, declarator->u.id.id, type);
 	if (size_varies)
 	  C_DECL_VARIABLE_SIZE (decl) = 1;
 
@@ -8009,7 +8008,7 @@  grokfield (location_t loc,
 {
   tree value;
 
-  if (declarator->kind == cdk_id && declarator->u.id == NULL_TREE
+  if (declarator->kind == cdk_id && declarator->u.id.id == NULL_TREE
       && width == NULL_TREE)
     {
       /* This is an unnamed decl.
@@ -10281,7 +10280,8 @@  build_id_declarator (tree ident)
   struct c_declarator *ret = XOBNEW (&parser_obstack, struct c_declarator);
   ret->kind = cdk_id;
   ret->declarator = 0;
-  ret->u.id = ident;
+  ret->u.id.id = ident;
+  ret->u.id.attrs = NULL_TREE;
   /* Default value - may get reset to a more precise location. */
   ret->id_loc = input_location;
   return ret;
@@ -11454,7 +11454,7 @@  finish_declspecs (struct c_declspecs *specs)
       /* Set a dummy type.  */
       if (TREE_CODE (specs->type) == ERROR_MARK)
         specs->type = integer_type_node;
-      return specs;
+      goto handle_postfix_attrs;
     }
 
   /* If none of "void", "_Bool", "char", "int", "float" or "double"
@@ -11715,6 +11715,7 @@  finish_declspecs (struct c_declspecs *specs)
     default:
       gcc_unreachable ();
     }
+ handle_postfix_attrs:
   if (specs->type != NULL)
     {
       specs->postfix_attrs = c_warn_type_attributes (specs->postfix_attrs);
Index: gcc/c/c-parser.c
===================================================================
--- gcc/c/c-parser.c	(revision 278604)
+++ gcc/c/c-parser.c	(working copy)
@@ -3857,11 +3857,7 @@  c_parser_direct_declarator (c_parser *parser, bool
       inner->id_loc = c_parser_peek_token (parser)->location;
       c_parser_consume_token (parser);
       if (c_parser_nth_token_starts_std_attributes (parser, 1))
-	{
-	  tree std_attrs = c_parser_std_attribute_specifier_sequence (parser);
-	  if (std_attrs)
-	    inner = build_attrs_declarator (std_attrs, inner);
-	}
+	inner->u.id.attrs = c_parser_std_attribute_specifier_sequence (parser);
       return c_parser_direct_declarator_inner (parser, *seen_id, inner);
     }
 
@@ -3898,9 +3894,7 @@  c_parser_direct_declarator (c_parser *parser, bool
 	    return NULL;
 	  else
 	    {
-	      inner
-		= build_function_declarator (args,
-					     build_id_declarator (NULL_TREE));
+	      inner = build_id_declarator (NULL_TREE);
 	      if (!(args->types
 		    && args->types != error_mark_node
 		    && TREE_CODE (TREE_VALUE (args->types)) == IDENTIFIER_NODE)
@@ -3911,6 +3905,7 @@  c_parser_direct_declarator (c_parser *parser, bool
 		  if (std_attrs)
 		    inner = build_attrs_declarator (std_attrs, inner);
 		}
+	      inner = build_function_declarator (args, inner);
 	      return c_parser_direct_declarator_inner (parser, *seen_id,
 						       inner);
 	    }
@@ -4028,7 +4023,6 @@  c_parser_direct_declarator_inner (c_parser *parser
 					   static_seen, star_seen);
       if (declarator == NULL)
 	return NULL;
-      inner = set_array_declarator_inner (declarator, inner);
       if (c_parser_nth_token_starts_std_attributes (parser, 1))
 	{
 	  tree std_attrs
@@ -4036,6 +4030,7 @@  c_parser_direct_declarator_inner (c_parser *parser
 	  if (std_attrs)
 	    inner = build_attrs_declarator (std_attrs, inner);
 	}
+      inner = set_array_declarator_inner (declarator, inner);
       return c_parser_direct_declarator_inner (parser, id_present, inner);
     }
   else if (c_parser_next_token_is (parser, CPP_OPEN_PAREN))
@@ -4052,7 +4047,6 @@  c_parser_direct_declarator_inner (c_parser *parser
 	return NULL;
       else
 	{
-	  inner = build_function_declarator (args, inner);
 	  if (!(args->types
 		&& args->types != error_mark_node
 		&& TREE_CODE (TREE_VALUE (args->types)) == IDENTIFIER_NODE)
@@ -4063,6 +4057,7 @@  c_parser_direct_declarator_inner (c_parser *parser
 	      if (std_attrs)
 		inner = build_attrs_declarator (std_attrs, inner);
 	    }
+	  inner = build_function_declarator (args, inner);
 	  return c_parser_direct_declarator_inner (parser, id_present, inner);
 	}
     }
@@ -4352,7 +4347,7 @@  c_parser_parameter_declaration (c_parser *parser,
   c_declarator *id_declarator = declarator;
   while (id_declarator && id_declarator->kind != cdk_id)
     id_declarator = id_declarator->declarator;
-  location_t caret_loc = (id_declarator->u.id
+  location_t caret_loc = (id_declarator->u.id.id
 			  ? id_declarator->id_loc
 			  : start_loc);
   location_t param_loc = make_location (caret_loc, start_loc, end_loc);
Index: gcc/c/c-tree.h
===================================================================
--- gcc/c/c-tree.h	(revision 278604)
+++ gcc/c/c-tree.h	(working copy)
@@ -460,9 +460,15 @@  struct c_declarator {
   /* Except for cdk_id, the contained declarator.  For cdk_id, NULL.  */
   struct c_declarator *declarator;
   union {
-    /* For identifiers, an IDENTIFIER_NODE or NULL_TREE if an abstract
-       declarator.  */
-    tree id;
+    /* For identifiers.  */
+    struct {
+      /* An IDENTIFIER_NODE, or NULL_TREE if an abstract
+	 declarator.  */
+      tree id;
+      /* Any attributes (which apply to the declaration rather than to
+	 the type described by the outer declarators).  */
+      tree attrs;
+    } id;
     /* For functions.  */
     struct c_arg_info *arg_info;
     /* For arrays.  */
Index: gcc/c/gimple-parser.c
===================================================================
--- gcc/c/gimple-parser.c	(revision 278604)
+++ gcc/c/gimple-parser.c	(working copy)
@@ -2040,13 +2040,13 @@  c_parser_gimple_declaration (gimple_parser &parser
       unsigned version, ver_offset;
       if (declarator->kind == cdk_id
 	  && is_gimple_reg_type (specs->type)
-	  && c_parser_parse_ssa_name_id (declarator->u.id,
+	  && c_parser_parse_ssa_name_id (declarator->u.id.id,
 					 &version, &ver_offset)
 	  /* The following restricts it to unnamed anonymous SSA names
 	     which fails parsing of named ones in dumps (we could
 	     decide to not dump their name for -gimple).  */
 	  && ver_offset == 0)
-	c_parser_parse_ssa_name (parser, declarator->u.id, specs->type,
+	c_parser_parse_ssa_name (parser, declarator->u.id.id, specs->type,
 				 version, ver_offset);
       else
 	{
Index: gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C	(revision 278604)
+++ gcc/testsuite/g++.dg/cpp0x/gen-attrs-1.C	(working copy)
@@ -1,3 +1,3 @@ 
 // { dg-do compile { target c++11 } }
 
-int **** [[gnu::format(printf, 1, 2)]] foo(const char *, ...); // { dg-warning "ignored" }
+int **** [[gnu::format(printf, 1, 2)]] foo(const char *, ...); // { dg-warning "only applies to function types" }
Index: gcc/testsuite/g++.dg/cpp0x/gen-attrs-22.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/gen-attrs-22.C	(revision 278604)
+++ gcc/testsuite/g++.dg/cpp0x/gen-attrs-22.C	(working copy)
@@ -3,5 +3,5 @@ 
 
 void f()
 {
-  static_cast<float *[[gnu::unused]]>(0); // { dg-warning "ignored" }
+  static_cast<float *[[gnu::unused]]>(0);
 }
Index: gcc/testsuite/g++.dg/cpp0x/gen-attrs-4.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/gen-attrs-4.C	(revision 278604)
+++ gcc/testsuite/g++.dg/cpp0x/gen-attrs-4.C	(working copy)
@@ -21,7 +21,7 @@  void two [[gnu::unused]] (void) {}
 [[gnu::unused]]
 int
 five(void)
-[[noreturn]] // { dg-warning "ignored" }
+[[noreturn]] // { dg-warning "does not apply to types" }
 { return 0; }
 
 [[noreturn]]
Index: gcc/testsuite/g++.dg/cpp0x/lambda/lambda-attr1.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/lambda/lambda-attr1.C	(revision 278604)
+++ gcc/testsuite/g++.dg/cpp0x/lambda/lambda-attr1.C	(working copy)
@@ -1,3 +1,3 @@ 
 // { dg-do compile { target c++11 } }
 
-auto l = []() [[noreturn]] {};	// { dg-warning "ignored" }
+auto l = []() [[noreturn]] {};	// { dg-warning "does not apply to types" }
Index: gcc/testsuite/gcc.dg/gnu2x-attrs-1.c
===================================================================
--- gcc/testsuite/gcc.dg/gnu2x-attrs-1.c	(revision 278604)
+++ gcc/testsuite/gcc.dg/gnu2x-attrs-1.c	(working copy)
@@ -7,8 +7,7 @@  void f (void) {};
 
 [[gnu::alias("f")]] void g (void); /* { dg-error "only weak" "" { target *-*-darwin* } } */
 
-void [[gnu::alias("f")]] h (void); /* { dg-warning "ignored" } */
-/* { dg-message "that appertains to a type-specifier" "appertains" { target *-*-* } .-1 } */
+void [[gnu::alias("f")]] h (void); /* { dg-warning "does not apply to types" } */
 
 struct [[gnu::packed]] s { int a; char b; };
 _Static_assert (sizeof (struct s) == (sizeof (int) + sizeof (char)));
Index: gcc/testsuite/gcc.dg/gnu2x-attrs-2.c
===================================================================
--- gcc/testsuite/gcc.dg/gnu2x-attrs-2.c	(nonexistent)
+++ gcc/testsuite/gcc.dg/gnu2x-attrs-2.c	(working copy)
@@ -0,0 +1,33 @@ 
+/* Test C2x attribute syntax.  Test GNU attributes appertain to
+   appropriate constructs.  Attributes on types not being defined at
+   the time.  */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu2x -Wformat" } */
+
+typedef void va_type (const char *, ...);
+typedef va_type [[gnu::format (printf, 1, 2)]] printf_like_1;
+typedef void printf_like_2 (const char *, ...) [[gnu::format (printf, 1, 2)]];
+typedef __typeof__ (void (const char *, ...) [[gnu::format (printf, 1, 2)]])
+  printf_like_3;
+
+va_type func1;
+printf_like_1 func2;
+printf_like_2 func3;
+printf_like_3 func4;
+va_type [[gnu::format (printf, 1, 2)]] *func5 (void);
+
+void
+func_test (void)
+{
+  func1 ("%s", 1);
+  func2 ("%s", 1); /* { dg-warning "expects argument" } */
+  func3 ("%s", 1); /* { dg-warning "expects argument" } */
+  func4 ("%s", 1); /* { dg-warning "expects argument" } */
+  func5 () ("%s", 1); /* { dg-warning "expects argument" } */
+}
+
+typedef int A[2];
+
+__typeof__ (int [[gnu::deprecated]]) var1; /* { dg-warning "deprecated" } */
+__typeof__ (A [[gnu::deprecated]]) var2; /* { dg-warning "deprecated" } */
+__typeof__ (int [3] [[gnu::deprecated]]) var3; /* { dg-warning "deprecated" } */