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RE: Intrinsics for N2965: Type traits and base classes
- From: Michael Spertus <mike_spertus at symantec dot com>
- To: Benjamin Kosnik <bkoz at redhat dot com>
- Cc: Jonathan Wakely <jwakely dot gcc at gmail dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, Jason Merrill <jason at redhat dot com>, "libstdc++ at gcc dot gnu dot org" <libstdc++ at gcc dot gnu dot org>, Michael Spertus <mike_spertus at symantec dot com>
- Date: Sun, 9 Oct 2011 12:13:40 -0700
- Subject: RE: Intrinsics for N2965: Type traits and base classes
- References: <20110913154324.4be22faf@shotwell> <4E809F45.2010908@symantec.com> <20110927195930.54e0d0df@shotwell> <C83DA40E-0C0C-4F0F-96DE-D8B94038A29E@symantec.com> <CAH6eHdQCzY+fGErud70qZn8NM6_gn7=CuCmLge+3ACj471YHCQ@mail.gmail.com> <4E830B10.8020802@symantec.com> <4E831DF8.9080700@symantec.com> <20110929102215.33af0ba9@shotwell> <B3B7EEED51159748B7479527D3A7663C2FC50944E5@TUS1XCHEVSPIN34.SYMC.SYMANTEC.COM> <20111003214035.2cbbcaf8@shotwell> <20111003220353.7d511557@shotwell>
Here is a new diff that works for non-class types (fixing Benjamin's failing test), fixes some spacing and alphabetization, and doesn't inadvertently break the __underlying_type trait.
Index: libstdc++-v3/include/tr2/type_traits
===================================================================
--- libstdc++-v3/include/tr2/type_traits (revision 0)
+++ libstdc++-v3/include/tr2/type_traits (revision 0)
@@ -0,0 +1,96 @@
+// TR2 type_traits -*- C++ -*-
+
+// Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
+// Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file tr2/type_traits
+ * This is a TR2 C++ Library header.
+ */
+
+#ifndef _GLIBCXX_TR2_TYPE_TRAITS
+#define _GLIBCXX_TR2_TYPE_TRAITS 1
+
+#pragma GCC system_header
+#include <type_traits>
+#include <bits/c++config.h>
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+namespace tr2
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ /**
+ * @defgroup metaprogramming Type Traits
+ * @ingroup utilities
+ *
+ * Compile time type transformation and information.
+ * @{
+ */
+
+ template<typename... _Elements> struct typelist;
+ template<>
+ struct typelist<>
+ {
+ typedef std::true_type empty;
+ };
+
+ template<typename _First, typename... _Rest>
+ struct typelist<_First, _Rest...>
+ {
+ struct first
+ {
+ typedef _First type;
+ };
+
+ struct rest
+ {
+ typedef typelist<_Rest...> type;
+ };
+
+ typedef std::false_type empty;
+ };
+
+ // Sequence abstraction metafunctions default to looking in the type
+ template<typename T> struct first : public T::first {};
+ template<typename T> struct rest : public T::rest {};
+ template<typename T> struct empty : public T::empty {};
+
+
+ template<typename T>
+ struct bases
+ {
+ typedef typelist<__bases(T)...> type;
+ };
+
+ template<typename T>
+ struct direct_bases
+ {
+ typedef typelist<__direct_bases(T)...> type;
+ };
+
+_GLIBCXX_END_NAMESPACE_VERSION
+}
+}
+
+#endif // _GLIBCXX_TR2_TYPE_TRAITS
Index: gcc/c-family/c-common.c
===================================================================
--- gcc/c-family/c-common.c (revision 178892)
+++ gcc/c-family/c-common.c (working copy)
@@ -423,6 +423,7 @@
{ "__asm__", RID_ASM, 0 },
{ "__attribute", RID_ATTRIBUTE, 0 },
{ "__attribute__", RID_ATTRIBUTE, 0 },
+ { "__bases", RID_BASES, D_CXXONLY },
{ "__builtin_choose_expr", RID_CHOOSE_EXPR, D_CONLY },
{ "__builtin_complex", RID_BUILTIN_COMPLEX, D_CONLY },
{ "__builtin_offsetof", RID_OFFSETOF, 0 },
@@ -433,6 +434,7 @@
{ "__const", RID_CONST, 0 },
{ "__const__", RID_CONST, 0 },
{ "__decltype", RID_DECLTYPE, D_CXXONLY },
+ { "__direct_bases", RID_DIRECT_BASES, D_CXXONLY },
{ "__extension__", RID_EXTENSION, 0 },
{ "__func__", RID_C99_FUNCTION_NAME, 0 },
{ "__has_nothrow_assign", RID_HAS_NOTHROW_ASSIGN, D_CXXONLY },
Index: gcc/c-family/c-common.h
===================================================================
--- gcc/c-family/c-common.h (revision 178892)
+++ gcc/c-family/c-common.h (working copy)
@@ -129,12 +129,13 @@
RID_CONSTCAST, RID_DYNCAST, RID_REINTCAST, RID_STATCAST,
/* C++ extensions */
+ RID_BASES, RID_DIRECT_BASES,
RID_HAS_NOTHROW_ASSIGN, RID_HAS_NOTHROW_CONSTRUCTOR,
RID_HAS_NOTHROW_COPY, RID_HAS_TRIVIAL_ASSIGN,
RID_HAS_TRIVIAL_CONSTRUCTOR, RID_HAS_TRIVIAL_COPY,
RID_HAS_TRIVIAL_DESTRUCTOR, RID_HAS_VIRTUAL_DESTRUCTOR,
RID_IS_ABSTRACT, RID_IS_BASE_OF,
- RID_IS_CONVERTIBLE_TO, RID_IS_CLASS,
+ RID_IS_CLASS, RID_IS_CONVERTIBLE_TO,
RID_IS_EMPTY, RID_IS_ENUM,
RID_IS_LITERAL_TYPE, RID_IS_POD,
RID_IS_POLYMORPHIC, RID_IS_STD_LAYOUT,
Index: gcc/cp/pt.c
===================================================================
--- gcc/cp/pt.c (revision 178892)
+++ gcc/cp/pt.c (working copy)
@@ -2976,6 +2976,9 @@
}
break;
+ case BASES:
+ parameter_pack_p = true;
+ break;
default:
/* Not a parameter pack. */
break;
@@ -9123,6 +9126,15 @@
tree arg_pack = NULL_TREE;
tree orig_arg = NULL_TREE;
+ if (TREE_CODE (parm_pack) == BASES)
+ {
+ if (BASES_DIRECT (parm_pack))
+ return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack),
+ args, complain, in_decl, false));
+ else
+ return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
+ args, complain, in_decl, false));
+ }
if (TREE_CODE (parm_pack) == PARM_DECL)
{
if (!cp_unevaluated_operand)
Index: gcc/cp/semantics.c
===================================================================
--- gcc/cp/semantics.c (revision 178892)
+++ gcc/cp/semantics.c (working copy)
@@ -3407,6 +3407,150 @@
return underlying_type;
}
+/* Implement the __direct_bases keyword: Return the direct base classes
+ of type */
+
+tree
+calculate_direct_bases (tree type)
+{
+ VEC(tree, gc) *vector = make_tree_vector();
+ tree bases_vec = NULL_TREE;
+ VEC(tree, none) *base_binfos;
+ tree binfo;
+ unsigned i;
+
+ complete_type (type);
+
+ if (!NON_UNION_CLASS_TYPE_P (type))
+ return make_tree_vec (0);
+
+ base_binfos = BINFO_BASE_BINFOS (TYPE_BINFO (type));
+
+ /* Virtual bases are initialized first */
+ for (i = 0; VEC_iterate (tree, base_binfos, i, binfo); i++)
+ {
+ if (BINFO_VIRTUAL_P (binfo))
+ {
+ VEC_safe_push (tree, gc, vector, binfo);
+ }
+ }
+
+ /* Now non-virtuals */
+ for (i = 0; VEC_iterate (tree, base_binfos, i, binfo); i++)
+ {
+ if (!BINFO_VIRTUAL_P (binfo))
+ {
+ VEC_safe_push (tree, gc, vector, binfo);
+ }
+ }
+
+
+ bases_vec = make_tree_vec (VEC_length (tree, vector));
+
+ for (i = 0; i < VEC_length (tree, vector); ++i)
+ {
+ TREE_VEC_ELT (bases_vec, i) = BINFO_TYPE (VEC_index (tree, vector, i));
+ }
+ return bases_vec;
+}
+
+/* Implement the __bases keyword: Return the base classes
+ of type */
+
+/* Find morally non-virtual base classes by walking binfo hierarchy */
+/* Virtual base classes are handled separately in finish_bases */
+
+static tree
+dfs_calculate_bases_pre (tree binfo, void *data_)
+{
+ (void)data_;
+ /* Don't walk bases of virtual bases */
+ return BINFO_VIRTUAL_P (binfo) ? dfs_skip_bases : NULL_TREE;
+}
+
+static tree
+dfs_calculate_bases_post (tree binfo, void *data_)
+{
+ VEC(tree, gc) **data = (VEC(tree, gc) **) data_;
+ if (!BINFO_VIRTUAL_P (binfo))
+ {
+ VEC_safe_push (tree, gc, *data, BINFO_TYPE (binfo));
+ }
+ return NULL_TREE;
+}
+
+/* Calculates the morally non-virtual base classes of a class */
+static VEC(tree, gc) *
+calculate_bases_helper (tree type)
+{
+ VEC(tree, gc) *vector = make_tree_vector();
+
+ /* Now add non-virtual base classes in order of construction */
+ dfs_walk_all (TYPE_BINFO (type),
+ dfs_calculate_bases_pre, dfs_calculate_bases_post, &vector);
+ return vector;
+}
+
+tree
+calculate_bases (tree type)
+{
+ VEC(tree, gc) *vector = make_tree_vector();
+ tree bases_vec = NULL_TREE;
+ unsigned i;
+ VEC(tree, gc) *vbases;
+ VEC(tree, gc) *nonvbases;
+ tree binfo;
+
+ complete_type (type);
+
+ if (!NON_UNION_CLASS_TYPE_P (type))
+ return make_tree_vec (0);
+
+ /* First go through virtual base classes */
+ for (vbases = CLASSTYPE_VBASECLASSES (type), i = 0;
+ VEC_iterate (tree, vbases, i, binfo); i++)
+ {
+ VEC(tree, gc) *vbase_bases = calculate_bases_helper (BINFO_TYPE (binfo));
+ VEC_safe_splice (tree, gc, vector, vbase_bases);
+ release_tree_vector (vbase_bases);
+ }
+
+ /* Now for the non-virtual bases */
+ nonvbases = calculate_bases_helper (type);
+ VEC_safe_splice (tree, gc, vector, nonvbases);
+ release_tree_vector (nonvbases);
+
+ /* Last element is entire class, so don't copy */
+ bases_vec = make_tree_vec (VEC_length (tree, vector) - 1);
+
+ for (i = 0; i < VEC_length (tree, vector) - 1; ++i)
+ {
+ TREE_VEC_ELT (bases_vec, i) = VEC_index (tree, vector, i);
+ }
+ release_tree_vector (vector);
+ return bases_vec;
+}
+
+tree
+finish_bases (tree type, bool direct)
+{
+ tree bases = NULL_TREE;
+
+ if (!processing_template_decl)
+ {
+ /* Parameter packs can only be used in templates */
+ error ("Parameter pack __bases only valid in template declaration");
+ return error_mark_node;
+ }
+
+ bases = cxx_make_type (BASES);
+ BASES_TYPE (bases) = type;
+ BASES_DIRECT (bases) = direct;
+ SET_TYPE_STRUCTURAL_EQUALITY (bases);
+
+ return bases;
+}
+
/* Perform C++-specific checks for __builtin_offsetof before calling
fold_offsetof. */
Index: gcc/cp/parser.c
===================================================================
--- gcc/cp/parser.c (revision 178892)
+++ gcc/cp/parser.c (working copy)
@@ -7295,6 +7295,12 @@
case RID_UNDERLYING_TYPE:
kind = CPTK_UNDERLYING_TYPE;
break;
+ case RID_BASES:
+ kind = CPTK_BASES;
+ break;
+ case RID_DIRECT_BASES:
+ kind = CPTK_DIRECT_BASES;
+ break;
default:
gcc_unreachable ();
}
@@ -7339,9 +7345,17 @@
/* Complete the trait expression, which may mean either processing
the trait expr now or saving it for template instantiation. */
- return kind != CPTK_UNDERLYING_TYPE
- ? finish_trait_expr (kind, type1, type2)
- : finish_underlying_type (type1);
+ switch(kind)
+ {
+ case CPTK_UNDERLYING_TYPE:
+ return finish_underlying_type (type1);
+ case CPTK_BASES:
+ return finish_bases (type1, false);
+ case CPTK_DIRECT_BASES:
+ return finish_bases (type1, true);
+ default:
+ return finish_trait_expr (kind, type1, type2);
+ }
}
/* Lambdas that appear in variable initializer or default argument scope
@@ -12010,6 +12024,7 @@
parser->integral_constant_expression_p = false;
saved_non_ice_p = parser->non_integral_constant_expression_p;
parser->non_integral_constant_expression_p = false;
+
/* Parse the arguments. */
do
{
@@ -12827,7 +12842,6 @@
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,
@@ -12835,6 +12849,14 @@
return type;
+ case RID_BASES:
+ case RID_DIRECT_BASES:
+ type = cp_parser_trait_expr (parser, token->keyword);
+ if (decl_specs)
+ cp_parser_set_decl_spec_type (decl_specs, type,
+ token->location,
+ /*type_definition_p=*/false);
+ return type;
default:
break;
}
@@ -20534,7 +20556,7 @@
}
/* Parse a template-argument-list, as well as the trailing ">" (but
- not the opening ">"). See cp_parser_template_argument_list for the
+ not the opening "<"). See cp_parser_template_argument_list for the
return value. */
static tree
Index: gcc/cp/cp-tree.def
===================================================================
--- gcc/cp/cp-tree.def (revision 178892)
+++ gcc/cp/cp-tree.def (working copy)
@@ -461,6 +461,10 @@
UNDERLYING_TYPE_TYPE is the type in question. */
DEFTREECODE (UNDERLYING_TYPE, "underlying_type", tcc_type, 0)
+/* A type designated by one of the bases type traits.
+ BASES_TYPE is the type in question. */
+DEFTREECODE (BASES, "bases", tcc_type, 0)
+
/* Used to represent the template information stored by template
specializations.
The accessors are:
Index: gcc/cp/cp-tree.h
===================================================================
--- gcc/cp/cp-tree.h (revision 178892)
+++ gcc/cp/cp-tree.h (working copy)
@@ -558,6 +558,8 @@
typedef enum cp_trait_kind
{
+ CPTK_BASES,
+ CPTK_DIRECT_BASES,
CPTK_HAS_NOTHROW_ASSIGN,
CPTK_HAS_NOTHROW_CONSTRUCTOR,
CPTK_HAS_NOTHROW_COPY,
@@ -3416,6 +3418,13 @@
#define UNDERLYING_TYPE_TYPE(NODE) \
(TYPE_VALUES_RAW (UNDERLYING_TYPE_CHECK (NODE)))
+/* The type in question for BASES. */
+#define BASES_TYPE(NODE) \
+ (TYPE_VALUES_RAW (BASES_CHECK (NODE)))
+
+#define BASES_DIRECT(NODE) \
+ TREE_LANG_FLAG_0 (BASES_CHECK (NODE))
+
/* The expression in question for a DECLTYPE_TYPE. */
#define DECLTYPE_TYPE_EXPR(NODE) (TYPE_VALUES_RAW (DECLTYPE_TYPE_CHECK (NODE)))
@@ -5430,6 +5439,9 @@
location_t);
extern tree finish_typeof (tree);
extern tree finish_underlying_type (tree);
+extern tree calculate_bases (tree);
+extern tree finish_bases (tree, bool);
+extern tree calculate_direct_bases (tree);
extern tree finish_offsetof (tree);
extern void finish_decl_cleanup (tree, tree);
extern void finish_eh_cleanup (tree);