On Sun, Oct 15, 2023 at 1:43 PM Patrick Palka <ppa...@redhat.com> wrote:
>
> On Fri, 13 Oct 2023, Ken Matsui wrote:
>
> > Since RID_MAX soon reaches 255 and all built-in traits are used
> > approximately
> > once in a C++ translation unit, this patch removes all RID values for
> > built-in
> > traits and uses gperf to look up the specific trait. Rather than holding
> > traits as keywords, we set all trait identifiers as cik_trait, which is a
> > new
> > cp_identifier_kind. As cik_reserved_for_udlit was unused and
> > cp_identifier_kind is 3 bits, we replaced the unused field with the new
> > cik_trait. Also, the later patch handles a subsequent token to the built-in
> > identifier so that we accept the use of non-function-like built-in trait
> > identifiers.
>
> Awesome! It's great we won't have to rename any existing identifiers in
> libstdc++ with this approach.
>
> I think this patch looks perfect, assuming we want to stick with the gperf
> approach, but I just noticed that IDENTIFIER nodes have an IDENTIFIER_CP_INDEX
> field which is currently only used for operator name identifiers to
> optimize looking up operator information. Could we reuse this field for
> IDENTIFIER_TRAIT_P identifiers as well in order to store their
> corresponding cp_trait_kind? If so then I think we wouldn't need to use
> gperf for the built-in traits at all, since the mapping from identifier
> to cp_trait_kind would be implicit in each IDENTIFIER node, which would
> perhaps be a nice simplification (and just as fast if not faster than gperf)?
>
Thank you! I think this way decreases the size of the compiler even if
we do not see speed improvements. Since IDENTIFIER_CP_INDEX
(base.u.bits.address_space) is an unsigned char (addr_space_t), we can
have only up to 255 traits. Is this acceptable?
> >
> > gcc/c-family/ChangeLog:
> >
> > * c-common.cc (c_common_reswords): Remove all mappings of
> > built-in traits.
> > * c-common.h (enum rid): Remove all RID values for built-in traits.
> >
> > gcc/cp/ChangeLog:
> >
> > * Make-lang.in: Add targets to generate cp-trait.gperf and
> > cp-trait.h.
> > * cp-objcp-common.cc (names_builtin_p): Remove all RID value
> > cases for built-in traits. Check for built-in traits via
> > the new cik_trait identifier.
> > * cp-tree.h (cik_reserved_for_udlit): Rename to ...
> > (cik_trait): ... this.
> > (IDENTIFIER_ANY_OP_P): Exclude cik_trait.
> > (IDENTIFIER_TRAIT_P): New macro to detect cik_trait.
> > * lex.cc (init_cp_traits): New function to set cik_trait for all
> > built-in trait identifiers.
> > (cxx_init): Call init_cp_traits function.
> > * parser.cc (cp_lexer_lookup_trait): New function to look up a
> > built-in trait from a token by gperf.
> > (cp_lexer_lookup_trait_expr): Likewise, look up an
> > expression-yielding built-in trait.
> > (cp_lexer_lookup_trait_type): Likewise, look up a type-yielding
> > built-in trait.
> > (cp_keyword_starts_decl_specifier_p): Remove all RID value cases
> > for built-in traits.
> > (cp_lexer_next_token_is_decl_specifier_keyword): Handle
> > type-yielding built-in traits.
> > (cp_parser_primary_expression): Remove all RID value cases for
> > built-in traits. Handle expression-yielding built-in traits.
> > (cp_parser_trait): Handle cp_trait instead of enum rid.
> > (cp_parser_simple_type_specifier): Remove all RID value cases
> > for built-in traits. Handle type-yielding built-in traits.
> > * cp-trait-head.in: New file.
> > * cp-trait.gperf: New file.
> > * cp-trait.h: New file.
> >
> > Co-authored-by: Patrick Palka <ppa...@redhat.com>
> > Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org>
> > ---
> > gcc/c-family/c-common.cc | 7 --
> > gcc/c-family/c-common.h | 5 -
> > gcc/cp/Make-lang.in | 26 ++++
> > gcc/cp/cp-objcp-common.cc | 8 +-
> > gcc/cp/cp-trait-head.in | 30 +++++
> > gcc/cp/cp-trait.gperf | 74 ++++++++++++
> > gcc/cp/cp-trait.h | 247 ++++++++++++++++++++++++++++++++++++++
> > gcc/cp/cp-tree.h | 14 ++-
> > gcc/cp/lex.cc | 19 +++
> > gcc/cp/parser.cc | 132 ++++++++++++--------
> > 10 files changed, 492 insertions(+), 70 deletions(-)
> > create mode 100644 gcc/cp/cp-trait-head.in
> > create mode 100644 gcc/cp/cp-trait.gperf
> > create mode 100644 gcc/cp/cp-trait.h
> >
> > diff --git a/gcc/c-family/c-common.cc b/gcc/c-family/c-common.cc
> > index f044db5b797..21fd333ef57 100644
> > --- a/gcc/c-family/c-common.cc
> > +++ b/gcc/c-family/c-common.cc
> > @@ -508,13 +508,6 @@ const struct c_common_resword c_common_reswords[] =
> > { "wchar_t", RID_WCHAR, D_CXXONLY },
> > { "while", RID_WHILE, 0 },
> >
> > -#define DEFTRAIT(TCC, CODE, NAME, ARITY) \
> > - { NAME, RID_##CODE, D_CXXONLY },
> > -#include "cp/cp-trait.def"
> > -#undef DEFTRAIT
> > - /* An alias for __is_same. */
> > - { "__is_same_as", RID_IS_SAME, D_CXXONLY },
> > -
> > /* C++ transactional memory. */
> > { "synchronized", RID_SYNCHRONIZED, D_CXX_OBJC | D_TRANSMEM },
> > { "atomic_noexcept", RID_ATOMIC_NOEXCEPT, D_CXXONLY | D_TRANSMEM },
> > diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
> > index 1fdba7ef3ea..051a442e0f4 100644
> > --- a/gcc/c-family/c-common.h
> > +++ b/gcc/c-family/c-common.h
> > @@ -168,11 +168,6 @@ enum rid
> > RID_BUILTIN_LAUNDER,
> > RID_BUILTIN_BIT_CAST,
> >
> > -#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/Make-lang.in b/gcc/cp/Make-lang.in
> > index 2727fb7f8cc..a67d1c3e9f3 100644
> > --- a/gcc/cp/Make-lang.in
> > +++ b/gcc/cp/Make-lang.in
> > @@ -34,6 +34,8 @@
> > # - the compiler proper (eg: cc1plus)
> > # - define the names for selecting the language in LANGUAGES.
> >
> > +AWK = @AWK@
> > +
> > # Actual names to use when installing a native compiler.
> > CXX_INSTALL_NAME := $(shell echo c++|sed '$(program_transform_name)')
> > GXX_INSTALL_NAME := $(shell echo g++|sed '$(program_transform_name)')
> > @@ -186,6 +188,30 @@ endif
> > # This is the file that depends on the generated header file.
> > cp/name-lookup.o: $(srcdir)/cp/std-name-hint.h
> >
> > +# We always need the dependency on the .gperf file
> > +# because it itself is generated.
> > +ifeq ($(ENABLE_MAINTAINER_RULES), true)
> > +$(srcdir)/cp/cp-trait.h: $(srcdir)/cp/cp-trait.gperf
> > +else
> > +$(srcdir)/cp/cp-trait.h: | $(srcdir)/cp/cp-trait.gperf
> > +endif
> > + gperf -o -C -E -k '8' -D -N 'find' -L C++ \
> > + $(srcdir)/cp/cp-trait.gperf --output-file
> > $(srcdir)/cp/cp-trait.h
> > +
> > +# The cp-trait.gperf file itself is generated from
> > +# cp-trait-head.in and cp-trait.def files.
> > +$(srcdir)/cp/cp-trait.gperf: $(srcdir)/cp/cp-trait-head.in
> > $(srcdir)/cp/cp-trait.def
> > + cat $< > $@
> > + $(AWK) -F', *' '/^DEFTRAIT_/ { \
> > + type = (index($$1, "DEFTRAIT_TYPE") != 0 ? "true" : "false");
> > \
> > + gsub(/DEFTRAIT_(EXPR|TYPE) \(/, "", $$1); \
> > + gsub(/\)/, "", $$3); \
> > + print $$2", CPTK_" $$1", "$$3", "type; \
> > + }' $(srcdir)/cp/cp-trait.def >> $@
> > +
> > +# This is the file that depends on the generated header file.
> > +cp/parser.o: $(srcdir)/cp/cp-trait.h
> > +
> > components_in_prev = "bfd opcodes binutils fixincludes gas gcc gmp mpfr
> > mpc isl gold intl ld libbacktrace libcpp libcody libdecnumber libiberty
> > libiberty-linker-plugin libiconv zlib lto-plugin libctf libsframe"
> > components_in_prev_target = "libstdc++-v3 libsanitizer libvtv libgcc
> > libbacktrace libphobos zlib libgomp libatomic"
> >
> > diff --git a/gcc/cp/cp-objcp-common.cc b/gcc/cp/cp-objcp-common.cc
> > index 93b027b80ce..b1adacfec07 100644
> > --- a/gcc/cp/cp-objcp-common.cc
> > +++ b/gcc/cp/cp-objcp-common.cc
> > @@ -421,6 +421,10 @@ names_builtin_p (const char *name)
> > }
> > }
> >
> > + /* Check for built-in traits. */
> > + if (IDENTIFIER_TRAIT_P (id))
> > + return true;
> > +
> > /* Also detect common reserved C++ words that aren't strictly built-in
> > functions. */
> > switch (C_RID_CODE (id))
> > @@ -434,10 +438,6 @@ names_builtin_p (const char *name)
> > case RID_BUILTIN_ASSOC_BARRIER:
> > case RID_BUILTIN_BIT_CAST:
> > case RID_OFFSETOF:
> > -#define DEFTRAIT(TCC, CODE, NAME, ARITY) \
> > - case RID_##CODE:
> > -#include "cp-trait.def"
> > -#undef DEFTRAIT
> > return true;
> > default:
> > break;
> > diff --git a/gcc/cp/cp-trait-head.in b/gcc/cp/cp-trait-head.in
> > new file mode 100644
> > index 00000000000..9357eea1238
> > --- /dev/null
> > +++ b/gcc/cp/cp-trait-head.in
> > @@ -0,0 +1,30 @@
> > +%language=C++
> > +%define class-name cp_trait_lookup
> > +%struct-type
> > +%{
> > +/* Copyright (C) 2023 Free Software Foundation, Inc.
> > +
> > +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/>. */
> > +%}
> > +struct cp_trait {
> > + const char *name;
> > + enum cp_trait_kind kind;
> > + short arity;
> > + bool type;
> > +};
> > +%%
> > +"__is_same_as", CPTK_IS_SAME, 2, false
> > diff --git a/gcc/cp/cp-trait.gperf b/gcc/cp/cp-trait.gperf
> > new file mode 100644
> > index 00000000000..47e3c1af499
> > --- /dev/null
> > +++ b/gcc/cp/cp-trait.gperf
> > @@ -0,0 +1,74 @@
> > +%language=C++
> > +%define class-name cp_trait_lookup
> > +%struct-type
> > +%{
> > +/* Copyright (C) 2023 Free Software Foundation, Inc.
> > +
> > +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/>. */
> > +%}
> > +struct cp_trait {
> > + const char *name;
> > + enum cp_trait_kind kind;
> > + short arity;
> > + bool type;
> > +};
> > +%%
> > +"__is_same_as", CPTK_IS_SAME, 2, false
> > +"__has_nothrow_assign", CPTK_HAS_NOTHROW_ASSIGN, 1, false
> > +"__has_nothrow_constructor", CPTK_HAS_NOTHROW_CONSTRUCTOR, 1, false
> > +"__has_nothrow_copy", CPTK_HAS_NOTHROW_COPY, 1, false
> > +"__has_trivial_assign", CPTK_HAS_TRIVIAL_ASSIGN, 1, false
> > +"__has_trivial_constructor", CPTK_HAS_TRIVIAL_CONSTRUCTOR, 1, false
> > +"__has_trivial_copy", CPTK_HAS_TRIVIAL_COPY, 1, false
> > +"__has_trivial_destructor", CPTK_HAS_TRIVIAL_DESTRUCTOR, 1, false
> > +"__has_unique_object_representations",
> > CPTK_HAS_UNIQUE_OBJ_REPRESENTATIONS, 1, false
> > +"__has_virtual_destructor", CPTK_HAS_VIRTUAL_DESTRUCTOR, 1, false
> > +"__is_abstract", CPTK_IS_ABSTRACT, 1, false
> > +"__is_aggregate", CPTK_IS_AGGREGATE, 1, false
> > +"__is_assignable", CPTK_IS_ASSIGNABLE, 2, false
> > +"__is_base_of", CPTK_IS_BASE_OF, 2, false
> > +"__is_class", CPTK_IS_CLASS, 1, false
> > +"__is_constructible", CPTK_IS_CONSTRUCTIBLE, -1, false
> > +"__is_convertible", CPTK_IS_CONVERTIBLE, 2, false
> > +"__is_empty", CPTK_IS_EMPTY, 1, false
> > +"__is_enum", CPTK_IS_ENUM, 1, false
> > +"__is_final", CPTK_IS_FINAL, 1, false
> > +"__is_layout_compatible", CPTK_IS_LAYOUT_COMPATIBLE, 2, false
> > +"__is_literal_type", CPTK_IS_LITERAL_TYPE, 1, false
> > +"__is_nothrow_assignable", CPTK_IS_NOTHROW_ASSIGNABLE, 2, false
> > +"__is_nothrow_constructible", CPTK_IS_NOTHROW_CONSTRUCTIBLE, -1, false
> > +"__is_nothrow_convertible", CPTK_IS_NOTHROW_CONVERTIBLE, 2, false
> > +"__is_pointer_interconvertible_base_of",
> > CPTK_IS_POINTER_INTERCONVERTIBLE_BASE_OF, 2, false
> > +"__is_pod", CPTK_IS_POD, 1, false
> > +"__is_polymorphic", CPTK_IS_POLYMORPHIC, 1, false
> > +"__is_same", CPTK_IS_SAME, 2, false
> > +"__is_standard_layout", CPTK_IS_STD_LAYOUT, 1, false
> > +"__is_trivial", CPTK_IS_TRIVIAL, 1, false
> > +"__is_trivially_assignable", CPTK_IS_TRIVIALLY_ASSIGNABLE, 2, false
> > +"__is_trivially_constructible", CPTK_IS_TRIVIALLY_CONSTRUCTIBLE, -1, false
> > +"__is_trivially_copyable", CPTK_IS_TRIVIALLY_COPYABLE, 1, false
> > +"__is_union", CPTK_IS_UNION, 1, false
> > +"__reference_constructs_from_temporary",
> > CPTK_REF_CONSTRUCTS_FROM_TEMPORARY, 2, false
> > +"__reference_converts_from_temporary", CPTK_REF_CONVERTS_FROM_TEMPORARY,
> > 2, false
> > +"__remove_cv", CPTK_REMOVE_CV, 1, true
> > +"__remove_cvref", CPTK_REMOVE_CVREF, 1, true
> > +"__remove_reference", CPTK_REMOVE_REFERENCE, 1, true
> > +"__type_pack_element", CPTK_TYPE_PACK_ELEMENT, -1, true
> > +"__underlying_type", CPTK_UNDERLYING_TYPE, 1, true
> > +"__is_deducible ", CPTK_IS_DEDUCIBLE, 2, false
> > +"__bases", CPTK_BASES, 1, true
> > +"__direct_bases", CPTK_DIRECT_BASES, 1, true
> > diff --git a/gcc/cp/cp-trait.h b/gcc/cp/cp-trait.h
> > new file mode 100644
> > index 00000000000..97ba8492d15
> > --- /dev/null
> > +++ b/gcc/cp/cp-trait.h
> > @@ -0,0 +1,247 @@
> > +/* C++ code produced by gperf version 3.1 */
> > +/* Command-line: gperf -o -C -E -k 8 -D -N find -L C++ --output-file
> > ../../gcc/cp/cp-trait.h ../../gcc/cp/cp-trait.gperf */
> > +
> > +#if !((' ' == 32) && ('!' == 33) && ('"' == 34) && ('#' == 35) \
> > + && ('%' == 37) && ('&' == 38) && ('\'' == 39) && ('(' == 40) \
> > + && (')' == 41) && ('*' == 42) && ('+' == 43) && (',' == 44) \
> > + && ('-' == 45) && ('.' == 46) && ('/' == 47) && ('0' == 48) \
> > + && ('1' == 49) && ('2' == 50) && ('3' == 51) && ('4' == 52) \
> > + && ('5' == 53) && ('6' == 54) && ('7' == 55) && ('8' == 56) \
> > + && ('9' == 57) && (':' == 58) && (';' == 59) && ('<' == 60) \
> > + && ('=' == 61) && ('>' == 62) && ('?' == 63) && ('A' == 65) \
> > + && ('B' == 66) && ('C' == 67) && ('D' == 68) && ('E' == 69) \
> > + && ('F' == 70) && ('G' == 71) && ('H' == 72) && ('I' == 73) \
> > + && ('J' == 74) && ('K' == 75) && ('L' == 76) && ('M' == 77) \
> > + && ('N' == 78) && ('O' == 79) && ('P' == 80) && ('Q' == 81) \
> > + && ('R' == 82) && ('S' == 83) && ('T' == 84) && ('U' == 85) \
> > + && ('V' == 86) && ('W' == 87) && ('X' == 88) && ('Y' == 89) \
> > + && ('Z' == 90) && ('[' == 91) && ('\\' == 92) && (']' == 93) \
> > + && ('^' == 94) && ('_' == 95) && ('a' == 97) && ('b' == 98) \
> > + && ('c' == 99) && ('d' == 100) && ('e' == 101) && ('f' == 102) \
> > + && ('g' == 103) && ('h' == 104) && ('i' == 105) && ('j' == 106) \
> > + && ('k' == 107) && ('l' == 108) && ('m' == 109) && ('n' == 110) \
> > + && ('o' == 111) && ('p' == 112) && ('q' == 113) && ('r' == 114) \
> > + && ('s' == 115) && ('t' == 116) && ('u' == 117) && ('v' == 118) \
> > + && ('w' == 119) && ('x' == 120) && ('y' == 121) && ('z' == 122) \
> > + && ('{' == 123) && ('|' == 124) && ('}' == 125) && ('~' == 126))
> > +/* The character set is not based on ISO-646. */
> > +#error "gperf generated tables don't work with this execution character
> > set. Please report a bug to <bug-gp...@gnu.org>."
> > +#endif
> > +
> > +#line 4 "../../gcc/cp/cp-trait.gperf"
> > +
> > +/* Copyright (C) 2023 Free Software Foundation, Inc.
> > +
> > +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/>. */
> > +#line 23 "../../gcc/cp/cp-trait.gperf"
> > +struct cp_trait {
> > + const char *name;
> > + enum cp_trait_kind kind;
> > + short arity;
> > + bool type;
> > +};
> > +/* maximum key range = 79, duplicates = 0 */
> > +
> > +class cp_trait_lookup
> > +{
> > +private:
> > + static inline unsigned int hash (const char *str, size_t len);
> > +public:
> > + static const struct cp_trait *find (const char *str, size_t len);
> > +};
> > +
> > +inline unsigned int
> > +cp_trait_lookup::hash (const char *str, size_t len)
> > +{
> > + static const unsigned char asso_values[] =
> > + {
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 1, 86, 86,
> > + 0, 35, 86, 0, 86, 0, 86, 86, 10, 10,
> > + 50, 15, 55, 86, 30, 5, 15, 0, 86, 86,
> > + 86, 20, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86, 86, 86, 86, 86,
> > + 86, 86, 86, 86, 86, 86
> > + };
> > + unsigned int hval = len;
> > +
> > + switch (hval)
> > + {
> > + default:
> > + hval += asso_values[static_cast<unsigned char>(str[7])];
> > + /*FALLTHROUGH*/
> > + case 7:
> > + break;
> > + }
> > + return hval;
> > +}
> > +
> > +const struct cp_trait *
> > +cp_trait_lookup::find (const char *str, size_t len)
> > +{
> > + enum
> > + {
> > + TOTAL_KEYWORDS = 45,
> > + MIN_WORD_LENGTH = 7,
> > + MAX_WORD_LENGTH = 37,
> > + MIN_HASH_VALUE = 7,
> > + MAX_HASH_VALUE = 85
> > + };
> > +
> > + static const struct cp_trait wordlist[] =
> > + {
> > +#line 73 "../../gcc/cp/cp-trait.gperf"
> > + {"__bases", CPTK_BASES, 1, true},
> > +#line 56 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_pod", CPTK_IS_POD, 1, false},
> > +#line 48 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_enum", CPTK_IS_ENUM, 1, false},
> > +#line 64 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_union", CPTK_IS_UNION, 1, false},
> > +#line 44 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_class", CPTK_IS_CLASS, 1, false},
> > +#line 60 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_trivial", CPTK_IS_TRIVIAL, 1, false},
> > +#line 41 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_aggregate", CPTK_IS_AGGREGATE, 1, false},
> > +#line 72 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_deducible ", CPTK_IS_DEDUCIBLE, 2, false},
> > +#line 43 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_base_of", CPTK_IS_BASE_OF, 2, false},
> > +#line 40 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_abstract", CPTK_IS_ABSTRACT, 1, false},
> > +#line 58 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_same", CPTK_IS_SAME, 2, false},
> > +#line 42 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_assignable", CPTK_IS_ASSIGNABLE, 2, false},
> > +#line 59 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_standard_layout", CPTK_IS_STD_LAYOUT, 1, false},
> > +#line 30 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_same_as", CPTK_IS_SAME, 2, false},
> > +#line 63 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_trivially_copyable", CPTK_IS_TRIVIALLY_COPYABLE, 1, false},
> > +#line 39 "../../gcc/cp/cp-trait.gperf"
> > + {"__has_virtual_destructor", CPTK_HAS_VIRTUAL_DESTRUCTOR, 1, false},
> > +#line 61 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_trivially_assignable", CPTK_IS_TRIVIALLY_ASSIGNABLE, 2,
> > false},
> > +#line 57 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_polymorphic", CPTK_IS_POLYMORPHIC, 1, false},
> > +#line 71 "../../gcc/cp/cp-trait.gperf"
> > + {"__underlying_type", CPTK_UNDERLYING_TYPE, 1, true},
> > +#line 62 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_trivially_constructible", CPTK_IS_TRIVIALLY_CONSTRUCTIBLE,
> > -1, false},
> > +#line 74 "../../gcc/cp/cp-trait.gperf"
> > + {"__direct_bases", CPTK_DIRECT_BASES, 1, true},
> > +#line 51 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_literal_type", CPTK_IS_LITERAL_TYPE, 1, false},
> > +#line 33 "../../gcc/cp/cp-trait.gperf"
> > + {"__has_nothrow_copy", CPTK_HAS_NOTHROW_COPY, 1, false},
> > +#line 31 "../../gcc/cp/cp-trait.gperf"
> > + {"__has_nothrow_assign", CPTK_HAS_NOTHROW_ASSIGN, 1, false},
> > +#line 55 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_pointer_interconvertible_base_of",
> > CPTK_IS_POINTER_INTERCONVERTIBLE_BASE_OF, 2, false},
> > +#line 52 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_nothrow_assignable", CPTK_IS_NOTHROW_ASSIGNABLE, 2, false},
> > +#line 54 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_nothrow_convertible", CPTK_IS_NOTHROW_CONVERTIBLE, 2, false},
> > +#line 32 "../../gcc/cp/cp-trait.gperf"
> > + {"__has_nothrow_constructor", CPTK_HAS_NOTHROW_CONSTRUCTOR, 1,
> > false},
> > +#line 53 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_nothrow_constructible", CPTK_IS_NOTHROW_CONSTRUCTIBLE, -1,
> > false},
> > +#line 50 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_layout_compatible", CPTK_IS_LAYOUT_COMPATIBLE, 2, false},
> > +#line 67 "../../gcc/cp/cp-trait.gperf"
> > + {"__remove_cv", CPTK_REMOVE_CV, 1, true},
> > +#line 36 "../../gcc/cp/cp-trait.gperf"
> > + {"__has_trivial_copy", CPTK_HAS_TRIVIAL_COPY, 1, false},
> > +#line 68 "../../gcc/cp/cp-trait.gperf"
> > + {"__remove_cvref", CPTK_REMOVE_CVREF, 1, true},
> > +#line 34 "../../gcc/cp/cp-trait.gperf"
> > + {"__has_trivial_assign", CPTK_HAS_TRIVIAL_ASSIGN, 1, false},
> > +#line 69 "../../gcc/cp/cp-trait.gperf"
> > + {"__remove_reference", CPTK_REMOVE_REFERENCE, 1, true},
> > +#line 37 "../../gcc/cp/cp-trait.gperf"
> > + {"__has_trivial_destructor", CPTK_HAS_TRIVIAL_DESTRUCTOR, 1, false},
> > +#line 35 "../../gcc/cp/cp-trait.gperf"
> > + {"__has_trivial_constructor", CPTK_HAS_TRIVIAL_CONSTRUCTOR, 1,
> > false},
> > +#line 49 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_final", CPTK_IS_FINAL, 1, false},
> > +#line 47 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_empty", CPTK_IS_EMPTY, 1, false},
> > +#line 46 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_convertible", CPTK_IS_CONVERTIBLE, 2, false},
> > +#line 45 "../../gcc/cp/cp-trait.gperf"
> > + {"__is_constructible", CPTK_IS_CONSTRUCTIBLE, -1, false},
> > +#line 66 "../../gcc/cp/cp-trait.gperf"
> > + {"__reference_converts_from_temporary",
> > CPTK_REF_CONVERTS_FROM_TEMPORARY, 2, false},
> > +#line 65 "../../gcc/cp/cp-trait.gperf"
> > + {"__reference_constructs_from_temporary",
> > CPTK_REF_CONSTRUCTS_FROM_TEMPORARY, 2, false},
> > +#line 70 "../../gcc/cp/cp-trait.gperf"
> > + {"__type_pack_element", CPTK_TYPE_PACK_ELEMENT, -1, true},
> > +#line 38 "../../gcc/cp/cp-trait.gperf"
> > + {"__has_unique_object_representations",
> > CPTK_HAS_UNIQUE_OBJ_REPRESENTATIONS, 1, false}
> > + };
> > +
> > + static const signed char lookup[] =
> > + {
> > + -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, -1,
> > + 6, 7, -1, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
> > + 19, 20, -1, -1, 21, 22, -1, 23, -1, 24, 25, 26, 27, 28,
> > + 29, -1, -1, -1, 30, -1, 31, 32, 33, -1, -1, 34, 35, 36,
> > + -1, -1, -1, -1, 37, -1, -1, -1, -1, 38, 39, -1, 40, -1,
> > + 41, -1, 42, -1, 43, -1, -1, -1, -1, -1, -1, -1, -1, -1,
> > + -1, 44
> > + };
> > +
> > + if (len <= MAX_WORD_LENGTH && len >= MIN_WORD_LENGTH)
> > + {
> > + unsigned int key = hash (str, len);
> > +
> > + if (key <= MAX_HASH_VALUE)
> > + {
> > + int index = lookup[key];
> > +
> > + if (index >= 0)
> > + {
> > + const char *s = wordlist[index].name;
> > +
> > + if (*str == *s && !strcmp (str + 1, s + 1))
> > + return &wordlist[index];
> > + }
> > + }
> > + }
> > + return 0;
> > +}
> > diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
> > index 6e34952da99..62e134886fb 100644
> > --- a/gcc/cp/cp-tree.h
> > +++ b/gcc/cp/cp-tree.h
> > @@ -1226,7 +1226,7 @@ enum cp_identifier_kind {
> > cik_simple_op = 4, /* Non-assignment operator name. */
> > cik_assign_op = 5, /* An assignment operator name. */
> > cik_conv_op = 6, /* Conversion operator name. */
> > - cik_reserved_for_udlit = 7, /* Not yet in use */
> > + cik_trait = 7, /* Built-in trait name. */
> > cik_max
> > };
> >
> > @@ -1271,9 +1271,9 @@ enum cp_identifier_kind {
> > & IDENTIFIER_KIND_BIT_0 (NODE))
> >
> > /* True if this identifier is for any operator name (including
> > - conversions). Value 4, 5, 6 or 7. */
> > + conversions). Value 4, 5, or 6. */
> > #define IDENTIFIER_ANY_OP_P(NODE) \
> > - (IDENTIFIER_KIND_BIT_2 (NODE))
> > + (IDENTIFIER_KIND_BIT_2 (NODE) && !IDENTIFIER_TRAIT_P (NODE))
> >
> > /* True if this identifier is for an overloaded operator. Values 4, 5. */
> > #define IDENTIFIER_OVL_OP_P(NODE) \
> > @@ -1286,12 +1286,18 @@ enum cp_identifier_kind {
> > & IDENTIFIER_KIND_BIT_0 (NODE))
> >
> > /* True if this identifier is the name of a type-conversion
> > - operator. Value 7. */
> > + operator. Value 6. */
> > #define IDENTIFIER_CONV_OP_P(NODE) \
> > (IDENTIFIER_ANY_OP_P (NODE) \
> > & IDENTIFIER_KIND_BIT_1 (NODE) \
> > & (!IDENTIFIER_KIND_BIT_0 (NODE)))
> >
> > +/* True if this identifier is the name of a built-in trait. */
> > +#define IDENTIFIER_TRAIT_P(NODE) \
> > + (IDENTIFIER_KIND_BIT_0 (NODE) \
> > + && IDENTIFIER_KIND_BIT_1 (NODE) \
> > + && IDENTIFIER_KIND_BIT_2 (NODE))
> > +
> > /* True if this identifier is a new or delete operator. */
> > #define IDENTIFIER_NEWDEL_OP_P(NODE) \
> > (IDENTIFIER_OVL_OP_P (NODE) \
> > diff --git a/gcc/cp/lex.cc b/gcc/cp/lex.cc
> > index 64bcfb18196..f6e1f6a4075 100644
> > --- a/gcc/cp/lex.cc
> > +++ b/gcc/cp/lex.cc
> > @@ -35,6 +35,7 @@ along with GCC; see the file COPYING3. If not see
> > #include "langhooks.h"
> >
> > static int interface_strcmp (const char *);
> > +static void init_cp_traits (void);
> > static void init_cp_pragma (void);
> >
> > static tree parse_strconst_pragma (const char *, int);
> > @@ -283,6 +284,23 @@ init_reswords (void)
> > }
> > }
> >
> > +/* Initialize the C++ traits. */
> > +static void
> > +init_cp_traits (void)
> > +{
> > + tree id;
> > +
> > +#define DEFTRAIT(TCC, CODE, NAME, ARITY) \
> > + id = get_identifier (NAME); \
> > + set_identifier_kind (id, cik_trait);
> > +#include "cp/cp-trait.def"
> > +#undef DEFTRAIT
> > +
> > + /* An alias for __is_same. */
> > + id = get_identifier ("__is_same_as");
> > + set_identifier_kind (id, cik_trait);
> > +}
> > +
> > static void
> > init_cp_pragma (void)
> > {
> > @@ -324,6 +342,7 @@ cxx_init (void)
> > input_location = BUILTINS_LOCATION;
> >
> > init_reswords ();
> > + init_cp_traits ();
> > init_tree ();
> > init_cp_semantics ();
> > init_operators ();
> > diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
> > index f3abae716fe..39952893ffa 100644
> > --- a/gcc/cp/parser.cc
> > +++ b/gcc/cp/parser.cc
> > @@ -49,6 +49,7 @@ along with GCC; see the file COPYING3. If not see
> > #include "contracts.h"
> > #include "bitmap.h"
> > #include "builtins.h"
> > +#include "cp-trait.h"
> >
> >
> > /* The lexer. */
> > @@ -246,6 +247,12 @@ static void cp_lexer_start_debugging
> > (cp_lexer *) ATTRIBUTE_UNUSED;
> > static void cp_lexer_stop_debugging
> > (cp_lexer *) ATTRIBUTE_UNUSED;
> > +static const cp_trait *cp_lexer_lookup_trait
> > + (const cp_token *);
> > +static const cp_trait *cp_lexer_lookup_trait_expr
> > + (const cp_token *);
> > +static const cp_trait *cp_lexer_lookup_trait_type
> > + (const cp_token *);
> >
> > static cp_token_cache *cp_token_cache_new
> > (cp_token *, cp_token *);
> > @@ -1167,12 +1174,6 @@ cp_keyword_starts_decl_specifier_p (enum rid keyword)
> > case RID_CONSTEVAL:
> > return true;
> >
> > -#define DEFTRAIT_TYPE(CODE, NAME, ARITY) \
> > - case RID_##CODE:
> > -#include "cp-trait.def"
> > -#undef DEFTRAIT_TYPE
> > - return true;
> > -
> > default:
> > if (keyword >= RID_FIRST_INT_N
> > && keyword < RID_FIRST_INT_N + NUM_INT_N_ENTS
> > @@ -1182,6 +1183,51 @@ cp_keyword_starts_decl_specifier_p (enum rid keyword)
> > }
> > }
> >
> > +/* Look ups the corresponding built-in trait if a given token is
> > + a built-in trait. Otherwise, returns nullptr. */
> > +
> > +static const cp_trait *
> > +cp_lexer_lookup_trait (const cp_token *token)
> > +{
> > + tree id = token->u.value;
> > +
> > + if (token->type == CPP_NAME
> > + && TREE_CODE (id) == IDENTIFIER_NODE
> > + && IDENTIFIER_TRAIT_P (id))
> > + {
> > + const char *id_str = IDENTIFIER_POINTER (id);
> > + const int id_len = IDENTIFIER_LENGTH (id);
> > + return cp_trait_lookup::find (id_str, id_len);
> > + }
> > + return nullptr;
> > +}
> > +
> > +/* Similarly, but only if the token is an expression-yielding
> > + built-in trait. */
> > +
> > +static const cp_trait *
> > +cp_lexer_lookup_trait_expr (const cp_token *token)
> > +{
> > + const cp_trait *trait = cp_lexer_lookup_trait (token);
> > + if (trait && !trait->type)
> > + return trait;
> > +
> > + return nullptr;
> > +}
> > +
> > +/* Similarly, but only if the token is a type-yielding
> > + built-in trait. */
> > +
> > +static const cp_trait *
> > +cp_lexer_lookup_trait_type (const cp_token *token)
> > +{
> > + const cp_trait *trait = cp_lexer_lookup_trait (token);
> > + if (trait && trait->type)
> > + return trait;
> > +
> > + return nullptr;
> > +}
> > +
> > /* Return true if the next token is a keyword for a decl-specifier. */
> >
> > static bool
> > @@ -1190,6 +1236,8 @@ cp_lexer_next_token_is_decl_specifier_keyword
> > (cp_lexer *lexer)
> > cp_token *token;
> >
> > token = cp_lexer_peek_token (lexer);
> > + if (cp_lexer_lookup_trait_type (token))
> > + return true;
> > return cp_keyword_starts_decl_specifier_p (token->keyword);
> > }
> >
> > @@ -2854,7 +2902,7 @@ static void cp_parser_late_parsing_default_args
> > static tree cp_parser_sizeof_operand
> > (cp_parser *, enum rid);
> > static cp_expr cp_parser_trait
> > - (cp_parser *, enum rid);
> > + (cp_parser *, const cp_trait *);
> > static bool cp_parser_declares_only_class_p
> > (cp_parser *);
> > static void cp_parser_set_storage_class
> > @@ -6021,12 +6069,6 @@ cp_parser_primary_expression (cp_parser *parser,
> > case RID_OFFSETOF:
> > return cp_parser_builtin_offsetof (parser);
> >
> > -#define DEFTRAIT_EXPR(CODE, NAME, ARITY) \
> > - case RID_##CODE:
> > -#include "cp-trait.def"
> > -#undef DEFTRAIT_EXPR
> > - return cp_parser_trait (parser, token->keyword);
> > -
> > // C++ concepts
> > case RID_REQUIRES:
> > return cp_parser_requires_expression (parser);
> > @@ -6065,6 +6107,12 @@ cp_parser_primary_expression (cp_parser *parser,
> > `::' as the beginning of a qualified-id, or the "operator"
> > keyword. */
> > case CPP_NAME:
> > + {
> > + const cp_trait* trait = cp_lexer_lookup_trait_expr (token);
> > + if (trait)
> > + return cp_parser_trait (parser, trait);
> > + }
> > + /* FALLTHRU */
> > case CPP_SCOPE:
> > case CPP_TEMPLATE_ID:
> > case CPP_NESTED_NAME_SPECIFIER:
> > @@ -11033,28 +11081,11 @@ cp_parser_builtin_offsetof (cp_parser *parser)
> > /* Parse a builtin trait expression or type. */
> >
> > static cp_expr
> > -cp_parser_trait (cp_parser* parser, enum rid keyword)
> > +cp_parser_trait (cp_parser* parser, const cp_trait* trait)
> > {
> > - cp_trait_kind kind;
> > tree type1, type2 = NULL_TREE;
> > - bool binary = false;
> > - bool variadic = false;
> > - bool type = false;
> > -
> > - switch (keyword)
> > - {
> > -#define DEFTRAIT(TCC, CODE, NAME, ARITY) \
> > - case RID_##CODE: \
> > - kind = CPTK_##CODE; \
> > - binary = (ARITY == 2); \
> > - variadic = (ARITY == -1); \
> > - type = (TCC == tcc_type); \
> > - break;
> > -#include "cp-trait.def"
> > -#undef DEFTRAIT
> > - default:
> > - gcc_unreachable ();
> > - }
> > + const bool binary = (trait->arity == 2);
> > + const bool variadic = (trait->arity == -1);
> >
> > /* Get location of initial token. */
> > location_t start_loc = cp_lexer_peek_token (parser->lexer)->location;
> > @@ -11063,12 +11094,12 @@ cp_parser_trait (cp_parser* parser, enum rid
> > keyword)
> > cp_lexer_consume_token (parser->lexer);
> >
> > matching_parens parens;
> > - if (kind == CPTK_TYPE_PACK_ELEMENT)
> > + if (trait->kind == CPTK_TYPE_PACK_ELEMENT)
> > cp_parser_require (parser, CPP_LESS, RT_LESS);
> > else
> > parens.require_open (parser);
> >
> > - if (kind == CPTK_IS_DEDUCIBLE)
> > + if (trait->kind == CPTK_IS_DEDUCIBLE)
> > {
> > const cp_token* token = cp_lexer_peek_token (parser->lexer);
> > type1 = cp_parser_id_expression (parser,
> > @@ -11079,7 +11110,7 @@ cp_parser_trait (cp_parser* parser, enum rid
> > keyword)
> > /*optional_p=*/false);
> > type1 = cp_parser_lookup_name_simple (parser, type1,
> > token->location);
> > }
> > - else if (kind == CPTK_TYPE_PACK_ELEMENT)
> > + else if (trait->kind == CPTK_TYPE_PACK_ELEMENT)
> > /* __type_pack_element takes an expression as its first argument and
> > uses
> > template-id syntax instead of function call syntax (for consistency
> > with Clang). We special case these properties of
> > __type_pack_element
> > @@ -11094,7 +11125,7 @@ cp_parser_trait (cp_parser* parser, enum rid
> > keyword)
> > if (type1 == error_mark_node)
> > return error_mark_node;
> >
> > - if (kind == CPTK_TYPE_PACK_ELEMENT)
> > + if (trait->kind == CPTK_TYPE_PACK_ELEMENT)
> > {
> > cp_parser_require (parser, CPP_COMMA, RT_COMMA);
> > tree trailing = cp_parser_enclosed_template_argument_list (parser);
> > @@ -11144,7 +11175,7 @@ cp_parser_trait (cp_parser* parser, enum rid
> > keyword)
> > }
> >
> > location_t finish_loc = cp_lexer_peek_token (parser->lexer)->location;
> > - if (kind == CPTK_TYPE_PACK_ELEMENT)
> > + if (trait->kind == CPTK_TYPE_PACK_ELEMENT)
> > /* cp_parser_enclosed_template_argument_list above already took care
> > of parsing the closing '>'. */;
> > else
> > @@ -11158,17 +11189,17 @@ cp_parser_trait (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. */
> > - switch (kind)
> > + switch (trait->kind)
> > {
> > case CPTK_BASES:
> > return cp_expr (finish_bases (type1, false), trait_loc);
> > case CPTK_DIRECT_BASES:
> > return cp_expr (finish_bases (type1, true), trait_loc);
> > default:
> > - if (type)
> > - return finish_trait_type (kind, type1, type2, tf_warning_or_error);
> > + if (trait->type)
> > + return finish_trait_type (trait->kind, type1, type2,
> > tf_warning_or_error);
> > else
> > - return finish_trait_expr (trait_loc, kind, type1, type2);
> > + return finish_trait_expr (trait_loc, trait->kind, type1, type2);
> > }
> > }
> >
> > @@ -20081,20 +20112,21 @@ cp_parser_simple_type_specifier (cp_parser*
> > parser,
> >
> > return type;
> >
> > -#define DEFTRAIT_TYPE(CODE, NAME, ARITY) \
> > - case RID_##CODE:
> > -#include "cp-trait.def"
> > -#undef DEFTRAIT_TYPE
> > - type = cp_parser_trait (parser, token->keyword);
> > + default:
> > + break;
> > + }
> > +
> > + /* If token is a type-yielding built-in traits, parse it. */
> > + const cp_trait* trait = cp_lexer_lookup_trait_type (token);
> > + if (trait)
> > + {
> > + type = cp_parser_trait (parser, trait);
> > if (decl_specs)
> > cp_parser_set_decl_spec_type (decl_specs, type,
> > token,
> > /*type_definition_p=*/false);
> >
> > return type;
> > -
> > - default:
> > - break;
> > }
> >
> > /* If token is an already-parsed decltype not followed by ::,
> > --
> > 2.42.0
> >
> >
>
