c-common.c (struct c_common_resword): Add __underlying_type.

/gcc
2011-04-25  Paolo Carlini  <paolo.carlini@oracle.com>

	* c-family/c-common.c (struct c_common_resword): Add
	__underlying_type.
	* c-family/c-common.h (enum rid): Add RID_UNDERLYING_TYPE.

/cp
2011-04-25  Paolo Carlini  <paolo.carlini@oracle.com>

	* cp-tree.def: Add a new UNDERLYING_TYPE tree code.
	* cp-tree.h (enum cp_trait_kind): Add CPTK_UNDERLYING_TYPE, tidy.
	(UNDERLYING_TYPE_TYPE): Add.
	* cp-objcp-common.c (cp_common_init_ts): Mark UNDERLYING_TYPE
	as TS_COMMON.
	* parser.c (cp_lexer_next_token_is_decl_specifier_keyword,
	cp_parser_simple_type_specifier): Handle UNDERLYING_TYPE.
	(cp_parser_trait_expr): Deal with RID_UNDERLYING_TYPE; tidy.
	* semantics.c (finish_underlying_type): New.
	* typeck.c (structural_comptypes): Handle UNDERLYING_TYPE.
	* error.c (dump_type, dump_type_prefix, dump_type_suffix): Likewise.
	* cxx-pretty-print.c (p_cxx_type_id): Likewise.
	* tree.c (cp_walk_subtrees): Likewise.
	* pt.c (for_each_template_parm_r, tsubst, unify,
	dependent_type_p_r): Likewise.
	* mangle.c (write_type): Sorry for __underlying_type.
	* doc/extend.texi: Document __underlying_type.

/testsuite
2011-04-25  Paolo Carlini  <paolo.carlini@oracle.com>

	* g++.dg/ext/underlying_type1.C: New.
	* g++.dg/ext/underlying_type2.C: Likewise.
	* g++.dg/ext/underlying_type3.C: Likewise.
	* g++.dg/ext/underlying_type4.C: Likewise.
	* g++.dg/ext/underlying_type5.C: Likewise.
	* g++.dg/ext/underlying_type6.C: Likewise.
	* g++.dg/ext/underlying_type7.C: Likewise.
	* g++.dg/ext/underlying_type8.C: Likewise.
	* g++.dg/ext/underlying_type9.C: Likewise.
	* g++.dg/ext/underlying_type10.C: Likewise.

From-SVN: r172943

1 files changed, 25 insertions, 5 deletions

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 7d3121c..bb97700 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -1,6 +1,6 @@
 /* C++ Parser.
    Copyright (C) 2000, 2001, 2002, 2003, 2004,
-   2005, 2007, 2008, 2009, 2010  Free Software Foundation, Inc.
+   2005, 2007, 2008, 2009, 2010, 2011  Free Software Foundation, Inc.
    Written by Mark Mitchell <mark@codesourcery.com>.
 
    This file is part of GCC.
@@ -654,6 +654,7 @@ cp_lexer_next_token_is_decl_specifier_keyword (cp_lexer *lexer)
     case RID_TYPEOF:
       /* C++0x extensions.  */
     case RID_DECLTYPE:
+    case RID_UNDERLYING_TYPE:
       return true;
 
     default:
@@ -7129,7 +7130,10 @@ cp_parser_builtin_offsetof (cp_parser *parser)
   return expr;
 }
 
-/* Parse a trait expression.  */
+/* Parse a trait expression.
+
+   Returns a representation of the expression, the underlying type
+   of the type at issue when KEYWORD is RID_UNDERLYING_TYPE.  */
 
 static tree
 cp_parser_trait_expr (cp_parser* parser, enum rid keyword)
@@ -7185,6 +7189,9 @@ cp_parser_trait_expr (cp_parser* parser, enum rid keyword)
     case RID_IS_ENUM:
       kind = CPTK_IS_ENUM;
       break;
+    case RID_IS_LITERAL_TYPE:
+      kind = CPTK_IS_LITERAL_TYPE;
+      break;
     case RID_IS_POD:
       kind = CPTK_IS_POD;
       break;
@@ -7200,8 +7207,8 @@ cp_parser_trait_expr (cp_parser* parser, enum rid keyword)
     case RID_IS_UNION:
       kind = CPTK_IS_UNION;
       break;
-    case RID_IS_LITERAL_TYPE:
-      kind = CPTK_IS_LITERAL_TYPE;
+    case RID_UNDERLYING_TYPE:
+      kind = CPTK_UNDERLYING_TYPE;
       break;
     default:
       gcc_unreachable ();
@@ -7247,7 +7254,9 @@ cp_parser_trait_expr (cp_parser* parser, enum rid keyword)
 
   /* Complete the trait expression, which may mean either processing
      the trait expr now or saving it for template instantiation.  */
-  return finish_trait_expr (kind, type1, type2);
+  return kind != CPTK_UNDERLYING_TYPE
+    ? finish_trait_expr (kind, type1, type2)
+    : finish_underlying_type (type1);
 }
 
 /* Lambdas that appear in variable initializer or default argument scope
@@ -12505,6 +12514,7 @@ cp_parser_type_specifier (cp_parser* parser,
      decltype ( expression )   
      char16_t
      char32_t
+     __underlying_type ( type-id )
 
    GNU Extension:
 
@@ -12621,6 +12631,16 @@ cp_parser_simple_type_specifier (cp_parser* parser,
 
       return type;
 
+    case RID_UNDERLYING_TYPE:
+      type = cp_parser_trait_expr (parser, RID_UNDERLYING_TYPE);
+
+      if (decl_specs)
+	cp_parser_set_decl_spec_type (decl_specs, type,
+				      token->location,
+				      /*user_defined_p=*/true);
+
+      return type;
+
     default:
       break;
     }