On Thu, 29 Sep 2022, Marek Polacek wrote: > On Thu, Sep 29, 2022 at 11:05:04AM -0400, Patrick Palka via Gcc-patches wrote: > > Adding a new builtin trait currently involves some boilerplate (as can > > be seen in r13-2956-g9ca147154074a0) of defining corresponding RID_ and > > CPTK_ enumerators and adding them to various switch statements across > > many files. The exact switch statements we need to change is determined > > by whether the proposed trait yields a type or an expression. > > > > This RFC patch attempts to streamline this process via a centralized > > cp-trait.def file for declaring the important parts about a builtin trait > > (whether it yields a type or an expression, its code, its spelling and > > its arity) and using this file to automate away the switch statement > > addition boilerplate. It also converts 9 traits to use this approach > > by way of example (we can convert all the traits once the design is > > settled). > > > > After this change, the process of adding a new builtin trait is just > > (modulo tests): declare it in cp-trait.def, define its behavior in > > finish_trait_type/expr, and handle it in diagnose_trait_expr if it's > > an expression-yielding trait (this last step is unfortunate but since > > the switch has no default case, we'll at least get a diagnostic if we > > forget to do it). > > > > Does this look like a good approach? > > I think it'd be fantastic to have this. It's been very easy to forget > to update pp_cxx_trait, or names_builtin_p. cp-trait.def just needs to > describe what the arguments mean.
Here's v2 which documents cp-trait.def and factors out its macro definitions into cp-trait-head.h and cp-trait-tail.h: -- >8 -- gcc/c-family/ChangeLog: * c-common.cc (c_common_reswords): Use cp/cp-trait.def to handle C++ traits. * c-common.h (enum rid): Likewise. gcc/cp/ChangeLog: * constraint.cc (diagnose_trait_expr): Likewise. * cp-objcp-common.cc (names_builtin_p): Likewise. * cp-tree.h (enum cp_trait_kind): Likewise. * cxx-pretty-print (pp_cxx_trait): Likewise. * parser.cc (cp_keyword_starts_decl_specifier_p): Likewise. (cp_parser_primary_expression): Likewise. (cp_parser_trait): Likewise. (cp_parser_simple_type_specifier): Likewise. * cp-trait-head.h: New file. * cp-trait-tail.h: New file. * cp-trait.def: New file. --- gcc/c-family/c-common.cc | 13 +++----- gcc/c-family/c-common.h | 8 ++--- gcc/cp/constraint.cc | 7 ++-- gcc/cp/cp-objcp-common.cc | 13 +++----- gcc/cp/cp-trait-head.h | 48 +++++++++++++++++++++++++++ gcc/cp/cp-trait-tail.h | 30 +++++++++++++++++ gcc/cp/cp-trait.def | 45 +++++++++++++++++++++++++ gcc/cp/cp-tree.h | 13 +++----- gcc/cp/cxx-pretty-print.cc | 31 +++--------------- gcc/cp/parser.cc | 67 ++++++++++++-------------------------- 10 files changed, 168 insertions(+), 107 deletions(-) create mode 100644 gcc/cp/cp-trait-head.h create mode 100644 gcc/cp/cp-trait-tail.h create mode 100644 gcc/cp/cp-trait.def diff --git a/gcc/c-family/c-common.cc b/gcc/c-family/c-common.cc index 6e0af863a49..1b2fd37c583 100644 --- a/gcc/c-family/c-common.cc +++ b/gcc/c-family/c-common.cc @@ -537,19 +537,14 @@ const struct c_common_resword c_common_reswords[] = { "volatile", RID_VOLATILE, 0 }, { "wchar_t", RID_WCHAR, D_CXXONLY }, { "while", RID_WHILE, 0 }, - { "__is_assignable", RID_IS_ASSIGNABLE, D_CXXONLY }, - { "__is_constructible", RID_IS_CONSTRUCTIBLE, D_CXXONLY }, - { "__is_nothrow_assignable", RID_IS_NOTHROW_ASSIGNABLE, D_CXXONLY }, - { "__is_nothrow_constructible", RID_IS_NOTHROW_CONSTRUCTIBLE, D_CXXONLY }, - { "__is_convertible", RID_IS_CONVERTIBLE, D_CXXONLY }, - { "__is_nothrow_convertible", RID_IS_NOTHROW_CONVERTIBLE, D_CXXONLY }, { "__reference_constructs_from_temporary", RID_REF_CONSTRUCTS_FROM_TEMPORARY, D_CXXONLY }, { "__reference_converts_from_temporary", RID_REF_CONVERTS_FROM_TEMPORARY, D_CXXONLY }, - { "__remove_cv", RID_REMOVE_CV, D_CXXONLY }, - { "__remove_reference", RID_REMOVE_REFERENCE, D_CXXONLY }, - { "__remove_cvref", RID_REMOVE_CVREF, D_CXXONLY }, +#define DEFTRAIT(TCC, CODE, NAME, ARITY) \ + { NAME, RID_##CODE, D_CXXONLY }, +#include "cp/cp-trait.def" +#undef DEFTRAIT /* C++ transactional memory. */ { "synchronized", RID_SYNCHRONIZED, D_CXX_OBJC | D_TRANSMEM }, diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h index d5c98d306ce..b306815c23b 100644 --- a/gcc/c-family/c-common.h +++ b/gcc/c-family/c-common.h @@ -182,12 +182,12 @@ enum rid RID_IS_TRIVIALLY_ASSIGNABLE, RID_IS_TRIVIALLY_CONSTRUCTIBLE, RID_IS_TRIVIALLY_COPYABLE, RID_IS_UNION, RID_UNDERLYING_TYPE, - RID_IS_ASSIGNABLE, RID_IS_CONSTRUCTIBLE, - RID_IS_NOTHROW_ASSIGNABLE, RID_IS_NOTHROW_CONSTRUCTIBLE, - RID_IS_CONVERTIBLE, RID_IS_NOTHROW_CONVERTIBLE, RID_REF_CONSTRUCTS_FROM_TEMPORARY, RID_REF_CONVERTS_FROM_TEMPORARY, - RID_REMOVE_CV, RID_REMOVE_REFERENCE, RID_REMOVE_CVREF, +#define DEFTRAIT(TCC, CODE, NAME, ARITY) \ + RID_##CODE, +#include "cp/cp-trait.def" +#undef DEFTRAIT /* C++11 */ RID_CONSTEXPR, RID_DECLTYPE, RID_NOEXCEPT, RID_NULLPTR, RID_STATIC_ASSERT, diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc index ca73aff3f38..9323bb091e1 100644 --- a/gcc/cp/constraint.cc +++ b/gcc/cp/constraint.cc @@ -3714,9 +3714,10 @@ diagnose_trait_expr (tree expr, tree args) case CPTK_BASES: case CPTK_DIRECT_BASES: case CPTK_UNDERLYING_TYPE: - case CPTK_REMOVE_CV: - case CPTK_REMOVE_REFERENCE: - case CPTK_REMOVE_CVREF: +#define DEFTRAIT_TYPE(CODE, NAME, ARITY) \ + case CPTK_##CODE: +#include "cp/cp-trait.def" +#undef DEFTRAIT_TYPE /* We shouldn't see these non-expression traits. */ gcc_unreachable (); /* We deliberately omit the default case so that when adding a new diff --git a/gcc/cp/cp-objcp-common.cc b/gcc/cp/cp-objcp-common.cc index 2d3f206b530..bc397a5447f 100644 --- a/gcc/cp/cp-objcp-common.cc +++ b/gcc/cp/cp-objcp-common.cc @@ -458,18 +458,13 @@ names_builtin_p (const char *name) case RID_IS_TRIVIALLY_CONSTRUCTIBLE: case RID_IS_TRIVIALLY_COPYABLE: case RID_IS_UNION: - case RID_IS_ASSIGNABLE: - case RID_IS_CONSTRUCTIBLE: - case RID_IS_NOTHROW_ASSIGNABLE: - case RID_IS_NOTHROW_CONSTRUCTIBLE: case RID_UNDERLYING_TYPE: - case RID_IS_CONVERTIBLE: - case RID_IS_NOTHROW_CONVERTIBLE: case RID_REF_CONSTRUCTS_FROM_TEMPORARY: case RID_REF_CONVERTS_FROM_TEMPORARY: - case RID_REMOVE_CV: - case RID_REMOVE_REFERENCE: - case RID_REMOVE_CVREF: +#define DEFTRAIT(TCC, CODE, NAME, ARITY) \ + case RID_##CODE: +#include "cp/cp-trait.def" +#undef DEFTRAIT return true; default: break; diff --git a/gcc/cp/cp-trait-head.h b/gcc/cp/cp-trait-head.h new file mode 100644 index 00000000000..5cec25af041 --- /dev/null +++ b/gcc/cp/cp-trait-head.h @@ -0,0 +1,48 @@ +/* Convenience macro definitions for programmatically tabulating over traits + defined in cp-trait.def. Used only by cp-trait.def. + + Copyright The GNU Toolchain Authors. + + This file is part of GCC. + + GCC 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. + + GCC 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. + + You should have received a copy of the GNU General Public License + along with GCC; see the file COPYING3. If not see + <http://www.gnu.org/licenses/>. */ + +/* Define DEFTRAIT(TCC, CODE, NAME, ARITY) and include cp-trait.def to + tabulate over all traits defined in cp-trait.def. The first argument + will be tcc_expression for expression-yielding traits and tcc_type for + type-yielding traits. */ + +#ifdef DEFTRAIT +#define DEFTRAIT_EXPR(CODE, NAME, ARITY) DEFTRAIT(tcc_expression, CODE, NAME, ARITY) +#define DEFTRAIT_TYPE(CODE, NAME, ARITY) DEFTRAIT(tcc_type, CODE, NAME, ARITY) +#define DEFTRAIT_EXPR_DEFAULTED +#define DEFTRAIT_TYPE_DEFAULTED +#endif + +/* Define DEFTRAIT_EXPR(CODE, NAME, ARITY) and include cp-trait.def to + tabulate over all expression-yielding traits. */ + +#ifndef DEFTRAIT_EXPR +#define DEFTRAIT_EXPR(CODE, NAME, ARITY) +#define DEFTRAIT_EXPR_DEFAULTED +#endif + +/* Define DEFTRAIT_TYPE(CODE, NAME, ARITY) and include cp-trait.def to + tabulate over all type-yielding traits. */ + +#ifndef DEFTRAIT_TYPE +#define DEFTRAIT_TYPE(CODE, NAME, ARITY) +#define DEFTRAIT_TYPE_DEFAULTED +#endif diff --git a/gcc/cp/cp-trait-tail.h b/gcc/cp/cp-trait-tail.h new file mode 100644 index 00000000000..cc8425119b2 --- /dev/null +++ b/gcc/cp/cp-trait-tail.h @@ -0,0 +1,30 @@ +/* Undefines the macros that may have been implicitly defined in + cp-trait-head.h. Used only by cp-trait.def. + + Copyright The GNU Toolchain Authors. + + This file is part of GCC. + + GCC 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. + + GCC 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. + + You should have received a copy of the GNU General Public License + along with GCC; see the file COPYING3. If not see + <http://www.gnu.org/licenses/>. */ + +#ifdef DEFTRAIT_EXPR_DEFAULTED +#undef DEFTRAIT_EXPR +#undef DEFTRAIT_EXPR_DEFAULTED +#endif + +#ifdef DEFTRAIT_TYPE_DEFAULTED +#undef DEFTRAIT_TYPE +#undef DEFTRAIT_TYPE_DEFAULTED +#endif diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def new file mode 100644 index 00000000000..61a0bbfdfa5 --- /dev/null +++ b/gcc/cp/cp-trait.def @@ -0,0 +1,45 @@ +/* This file contains the definitions for C++-specific builtin traits. + + Copyright The GNU Toolchain Authors. + + This file is part of GCC. + + GCC 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. + + GCC 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. + + You should have received a copy of the GNU General Public License + along with GCC; see the file COPYING3. If not see + <http://www.gnu.org/licenses/>. */ + +#include "cp-trait-head.h" + +/* Add a DEFTRAIT_EXPR (CODE, NAME, N) line to this file to define an + expression-yielding builtin trait with internal code name CODE, spelled + as NAME and takes exactly N type arguments (where N is either 1, 2, or + the special value -1 which denotes that it takes at least one argument). + Such traits are represented as TRAIT_EXPR tree whose TRAIT_EXPR_KIND is + CPTK_NAME. */ + +/* Add a DEFTRAIT_TYPE (CODE, NAME, N) line to this file to define a + type-yielding trait in the same manner as described above. Such traits + are represented as a TRAIT_TYPE tree whose TRAIT_TYPE_KIND is CPTK_NAME. */ + +DEFTRAIT_EXPR (IS_ASSIGNABLE, "__is_assignable", 2) +DEFTRAIT_EXPR (IS_NOTHROW_ASSIGNABLE, "__is_nothrow_assignable", 2) +DEFTRAIT_EXPR (IS_CONSTRUCTIBLE, "__is_constructible", -1) +DEFTRAIT_EXPR (IS_NOTHROW_CONSTRUCTIBLE, "__is_nothrow_constructible", -1) +DEFTRAIT_EXPR (IS_CONVERTIBLE, "__is_convertible", 2) +DEFTRAIT_EXPR (IS_NOTHROW_CONVERTIBLE, "__is_nothrow_convertible", 2) + +DEFTRAIT_TYPE (REMOVE_CV, "__remove_cv", 1) +DEFTRAIT_TYPE (REMOVE_REFERENCE, "__remove_reference", 1) +DEFTRAIT_TYPE (REMOVE_CVREF, "__remove_cvref", 1) + +#include "cp-trait-tail.h" diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index 3cbcdf726ca..8c5a85ab5fe 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -1405,17 +1405,12 @@ enum cp_trait_kind CPTK_IS_TRIVIALLY_COPYABLE, CPTK_IS_UNION, CPTK_UNDERLYING_TYPE, - CPTK_IS_ASSIGNABLE, - CPTK_IS_CONSTRUCTIBLE, - CPTK_IS_NOTHROW_ASSIGNABLE, - CPTK_IS_NOTHROW_CONSTRUCTIBLE, - CPTK_IS_CONVERTIBLE, - CPTK_IS_NOTHROW_CONVERTIBLE, CPTK_REF_CONSTRUCTS_FROM_TEMPORARY, CPTK_REF_CONVERTS_FROM_TEMPORARY, - CPTK_REMOVE_CV, - CPTK_REMOVE_REFERENCE, - CPTK_REMOVE_CVREF, +#define DEFTRAIT(TCC, CODE, NAME, ARITY) \ + CPTK_##CODE, +#include "cp/cp-trait.def" +#undef DEFTRAIT }; /* The types that we are processing. */ diff --git a/gcc/cp/cxx-pretty-print.cc b/gcc/cp/cxx-pretty-print.cc index b91615439e4..a2ddbcb899a 100644 --- a/gcc/cp/cxx-pretty-print.cc +++ b/gcc/cp/cxx-pretty-print.cc @@ -2701,24 +2701,6 @@ pp_cxx_trait (cxx_pretty_printer *pp, tree t) case CPTK_IS_LITERAL_TYPE: pp_cxx_ws_string (pp, "__is_literal_type"); break; - case CPTK_IS_ASSIGNABLE: - pp_cxx_ws_string (pp, "__is_assignable"); - break; - case CPTK_IS_CONSTRUCTIBLE: - pp_cxx_ws_string (pp, "__is_constructible"); - break; - case CPTK_IS_NOTHROW_ASSIGNABLE: - pp_cxx_ws_string (pp, "__is_nothrow_assignable"); - break; - case CPTK_IS_NOTHROW_CONSTRUCTIBLE: - pp_cxx_ws_string (pp, "__is_nothrow_constructible"); - break; - case CPTK_IS_CONVERTIBLE: - pp_cxx_ws_string (pp, "__is_convertible"); - break; - case CPTK_IS_NOTHROW_CONVERTIBLE: - pp_cxx_ws_string (pp, "__is_nothrow_convertible"); - break; case CPTK_REF_CONSTRUCTS_FROM_TEMPORARY: pp_cxx_ws_string (pp, "__reference_constructs_from_temporary"); break; @@ -2728,15 +2710,12 @@ pp_cxx_trait (cxx_pretty_printer *pp, tree t) case CPTK_UNDERLYING_TYPE: pp_cxx_ws_string (pp, "__underlying_type"); break; - case CPTK_REMOVE_CV: - pp_cxx_ws_string (pp, "__remove_cv"); - break; - case CPTK_REMOVE_REFERENCE: - pp_cxx_ws_string (pp, "__remove_reference"); - break; - case CPTK_REMOVE_CVREF: - pp_cxx_ws_string (pp, "__remove_cvref"); +#define DEFTRAIT(TCC, CODE, NAME, ARITY) \ + case CPTK_##CODE: \ + pp_cxx_ws_string (pp, NAME); \ break; +#include "cp/cp-trait.def" +#undef DEFTRAIT default: gcc_unreachable (); } diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc index d592d783250..138892716b4 100644 --- a/gcc/cp/parser.cc +++ b/gcc/cp/parser.cc @@ -1147,9 +1147,10 @@ cp_keyword_starts_decl_specifier_p (enum rid keyword) /* C++11 extensions. */ case RID_DECLTYPE: case RID_UNDERLYING_TYPE: - case RID_REMOVE_CV: - case RID_REMOVE_REFERENCE: - case RID_REMOVE_CVREF: +#define DEFTRAIT_TYPE(CODE, NAME, ARITY) \ + case RID_##CODE: +#include "cp/cp-trait.def" +#undef DEFTRAIT_TYPE case RID_CONSTEXPR: /* C++20 extensions. */ case RID_CONSTINIT: @@ -5923,14 +5924,12 @@ cp_parser_primary_expression (cp_parser *parser, case RID_IS_TRIVIALLY_CONSTRUCTIBLE: case RID_IS_TRIVIALLY_COPYABLE: case RID_IS_UNION: - case RID_IS_ASSIGNABLE: - case RID_IS_CONSTRUCTIBLE: - case RID_IS_NOTHROW_ASSIGNABLE: - case RID_IS_NOTHROW_CONSTRUCTIBLE: - case RID_IS_CONVERTIBLE: - case RID_IS_NOTHROW_CONVERTIBLE: case RID_REF_CONSTRUCTS_FROM_TEMPORARY: case RID_REF_CONVERTS_FROM_TEMPORARY: +#define DEFTRAIT_EXPR(CODE, NAME, ARITY) \ + case RID_##CODE: +#include "cp/cp-trait.def" +#undef DEFTRAIT_EXPR return cp_parser_trait (parser, token->keyword); // C++ concepts @@ -10998,30 +10997,6 @@ cp_parser_trait (cp_parser* parser, enum rid keyword) case RID_DIRECT_BASES: kind = CPTK_DIRECT_BASES; break; - case RID_IS_ASSIGNABLE: - kind = CPTK_IS_ASSIGNABLE; - binary = true; - break; - case RID_IS_CONSTRUCTIBLE: - kind = CPTK_IS_CONSTRUCTIBLE; - variadic = true; - break; - case RID_IS_NOTHROW_ASSIGNABLE: - kind = CPTK_IS_NOTHROW_ASSIGNABLE; - binary = true; - break; - case RID_IS_NOTHROW_CONSTRUCTIBLE: - kind = CPTK_IS_NOTHROW_CONSTRUCTIBLE; - variadic = true; - break; - case RID_IS_CONVERTIBLE: - kind = CPTK_IS_CONVERTIBLE; - binary = true; - break; - case RID_IS_NOTHROW_CONVERTIBLE: - kind = CPTK_IS_NOTHROW_CONVERTIBLE; - binary = true; - break; case RID_REF_CONSTRUCTS_FROM_TEMPORARY: kind = CPTK_REF_CONSTRUCTS_FROM_TEMPORARY; binary = true; @@ -11030,18 +11005,15 @@ cp_parser_trait (cp_parser* parser, enum rid keyword) kind = CPTK_REF_CONVERTS_FROM_TEMPORARY; binary = true; break; - case RID_REMOVE_CV: - kind = CPTK_REMOVE_CV; - type = true; - break; - case RID_REMOVE_REFERENCE: - kind = CPTK_REMOVE_REFERENCE; - type = true; - break; - case RID_REMOVE_CVREF: - kind = CPTK_REMOVE_CVREF; - type = true; +#define DEFTRAIT(TCC, CODE, NAME, ARITY) \ + case RID_##CODE: \ + type = (TCC == tcc_type); \ + kind = CPTK_##CODE; \ + binary = (ARITY == 2); \ + variadic = (ARITY == -1); \ break; +#include "cp/cp-trait.def" +#undef DEFTRAIT default: gcc_unreachable (); } @@ -19882,9 +19854,10 @@ cp_parser_simple_type_specifier (cp_parser* parser, return type; case RID_UNDERLYING_TYPE: - case RID_REMOVE_CV: - case RID_REMOVE_REFERENCE: - case RID_REMOVE_CVREF: +#define DEFTRAIT_TYPE(CODE, NAME, ARITY) \ + case RID_##CODE: +#include "cp/cp-trait.def" +#undef DEFTRAIT_TYPE type = cp_parser_trait (parser, token->keyword); if (decl_specs) cp_parser_set_decl_spec_type (decl_specs, type, -- 2.38.0.rc2