From 78739c2df788ee5c868d998a6333d453317d8711 Mon Sep 17 00:00:00 2001 From: Paul Fee Date: Mon, 25 Jan 2021 01:18:30 +0000 Subject: [PATCH] c++: Add support for -std=c++23 Derived from the changes that added C++2a support in 2017. r8-3237-g026a79f70cf33f836ea5275eda72d4870a3041e5 No C++23 features are added here. Use of -std=c++23 sets __cplusplus to 202100L. $ g++ -std=c++23 -dM -E -x c++ - < /dev/null | grep cplusplus #define __cplusplus 202100L gcc/ * doc/cpp.texi (__cplusplus): Document value for -std=c++23 or -std=gnu++23. * doc/invoke.texi: Document -std=c++23 and -std=gnu++23. * dwarf2out.c (highest_c_language): Recognise C++20 and C++23. (gen_compile_unit_die): Recognise C++23. gcc/c-family/ * c-common.h (cxx_dialect): Add cxx23 as a dialect. * c.opt: Add options for -std=c++23, std=c++2b, -std=gnu++23 and -std=gnu++2b * c-opts.c (set_std_cxx23): New. (c_common_handle_option): Set options when -std=c++23 is enabled. (c_common_post_options): Adjust comments. (set_std_cxx20): Likewise. gcc/testsuite/ * lib/target-supports.exp (check_effective_target_c++2a): Check for C++2a or C++23. (check_effective_target_c++20_down): New. (check_effective_target_c++23_only): New. (check_effective_target_c++23): New. * g++.dg/cpp23/cplusplus.C: New. libcpp/ * include/cpplib.h (c_lang): Add CXX23 and GNUCXX23. * init.c (lang_defaults): Add rows for CXX23 and GNUCXX23. (cpp_init_builtins): Set __cplusplus to 202100L for C++23. --- gcc/c-family/c-common.h | 4 +++- gcc/c-family/c-opts.c | 29 ++++++++++++++++++++++++-- gcc/c-family/c.opt | 18 +++++++++++++++- gcc/doc/cpp.texi | 7 ++++--- gcc/doc/invoke.texi | 12 +++++++++++ gcc/dwarf2out.c | 7 ++++++- gcc/testsuite/g++.dg/cpp23/cplusplus.C | 4 ++++ gcc/testsuite/lib/target-supports.exp | 28 ++++++++++++++++++++++++- libcpp/include/cpplib.h | 3 ++- libcpp/init.c | 9 +++++++- 10 files changed, 110 insertions(+), 11 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp23/cplusplus.C diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h index a65c78f7240..f30b6c6ac33 100644 --- a/gcc/c-family/c-common.h +++ b/gcc/c-family/c-common.h @@ -738,7 +738,9 @@ enum cxx_dialect { /* C++17 */ cxx17, /* C++20 */ - cxx20 + cxx20, + /* C++23 */ + cxx23 }; /* The C++ dialect being used. C++98 is the default. */ diff --git a/gcc/c-family/c-opts.c b/gcc/c-family/c-opts.c index 3cdf41bc6e2..bd15b9cd902 100644 --- a/gcc/c-family/c-opts.c +++ b/gcc/c-family/c-opts.c @@ -113,6 +113,7 @@ static void set_std_cxx11 (int); static void set_std_cxx14 (int); static void set_std_cxx17 (int); static void set_std_cxx20 (int); +static void set_std_cxx23 (int); static void set_std_c89 (int, int); static void set_std_c99 (int); static void set_std_c11 (int); @@ -649,6 +650,12 @@ c_common_handle_option (size_t scode, const char *arg, HOST_WIDE_INT value, set_std_cxx20 (code == OPT_std_c__20 /* ISO */); break; + case OPT_std_c__23: + case OPT_std_gnu__23: + if (!preprocessing_asm_p) + set_std_cxx23 (code == OPT_std_c__23 /* ISO */); + break; + case OPT_std_c90: case OPT_std_iso9899_199409: if (!preprocessing_asm_p) @@ -1019,7 +1026,7 @@ c_common_post_options (const char **pfilename) warn_narrowing = 1; /* Unless -f{,no-}ext-numeric-literals has been used explicitly, - for -std=c++{11,14,17,2a} default to -fno-ext-numeric-literals. */ + for -std=c++{11,14,17,20,23} default to -fno-ext-numeric-literals. */ if (flag_iso && !global_options_set.x_flag_ext_numeric_literals) cpp_opts->ext_numeric_literals = 0; } @@ -1763,7 +1770,7 @@ set_std_cxx20 (int iso) flag_no_gnu_keywords = iso; flag_no_nonansi_builtin = iso; flag_iso = iso; - /* C++17 includes the C11 standard library. */ + /* C++20 includes the C11 standard library. */ flag_isoc94 = 1; flag_isoc99 = 1; flag_isoc11 = 1; @@ -1773,6 +1780,24 @@ set_std_cxx20 (int iso) lang_hooks.name = "GNU C++20"; } +/* Set the C++ 2023 standard (without GNU extensions if ISO). */ +static void +set_std_cxx23 (int iso) +{ + cpp_set_lang (parse_in, iso ? CLK_CXX23: CLK_GNUCXX23); + flag_no_gnu_keywords = iso; + flag_no_nonansi_builtin = iso; + flag_iso = iso; + /* C++23 includes the C11 standard library. */ + flag_isoc94 = 1; + flag_isoc99 = 1; + flag_isoc11 = 1; + /* C++23 includes coroutines. */ + flag_coroutines = true; + cxx_dialect = cxx23; + lang_hooks.name = "GNU C++23"; +} + /* Args to -d specify what to dump. Silently ignore unrecognized options; they may be aimed at toplev.c. */ static void diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt index 1766364806e..b729be7f40e 100644 --- a/gcc/c-family/c.opt +++ b/gcc/c-family/c.opt @@ -2214,6 +2214,14 @@ std=c++20 C++ ObjC++ Conform to the ISO 2020 C++ draft standard (experimental and incomplete support). +std=c++2b +C++ ObjC++ Alias(std=c++23) +Conform to the ISO 2020 C++ draft standard (experimental and incomplete support). + +std=c++23 +C++ ObjC++ Undocumented +Conform to the ISO 2023 C++ draft standard (experimental and incomplete support). + std=c11 C ObjC Conform to the ISO 2011 C standard. @@ -2285,13 +2293,21 @@ C++ ObjC++ Conform to the ISO 2017 C++ standard with GNU extensions. std=gnu++2a -C++ ObjC++ Alias(std=gnu++20) +C++ ObjC++ Alias(std=gnu++20) Undocumented Conform to the ISO 2020 C++ draft standard with GNU extensions (experimental and incomplete support). std=gnu++20 C++ ObjC++ Conform to the ISO 2020 C++ draft standard with GNU extensions (experimental and incomplete support). +std=gnu++2b +C++ ObjC++ Alias(std=gnu++23) +Conform to the ISO 2023 C++ draft standard with GNU extensions (experimental and incomplete support). + +std=gnu++23 +C++ ObjC++ Undocumented +Conform to the ISO 2023 C++ draft standard with GNU extensions (experimental and incomplete support). + std=gnu11 C ObjC Conform to the ISO 2011 C standard with GNU extensions. diff --git a/gcc/doc/cpp.texi b/gcc/doc/cpp.texi index 25f2625d8bd..2c109bbc5bd 100644 --- a/gcc/doc/cpp.texi +++ b/gcc/doc/cpp.texi @@ -1907,9 +1907,10 @@ selected, the value of the macro is @code{201103L} for the 2011 C++ standard, @code{201402L} for the 2014 C++ standard, @code{201703L} for the 2017 C++ standard, -or an unspecified value strictly larger than @code{201703L} for the -experimental languages enabled by @option{-std=c++2a} and -@option{-std=gnu++2a}. +@code{202002L} for the 2020 C++ standard, +or an unspecified value strictly larger than @code{202002L} for the +experimental languages enabled by @option{-std=c++23} and +@option{-std=gnu++23}. @item __OBJC__ This macro is defined, with value 1, when the Objective-C compiler is in diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 34218a751f0..d9e49c4a0da 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -2430,6 +2430,18 @@ GNU dialect of @option{-std=c++20}. Support is experimental, and could change in incompatible ways in future releases. The name @samp{gnu++2a} is deprecated. + +@item c++2b +@itemx c++23 +The next revision of the ISO C++ standard, planned for +2023. Support is highly experimental, and will almost certainly +change in incompatible ways in future releases. + +@item gnu++2b +@itemx gnu++23 +GNU dialect of @option{-std=c++2b}. Support is highly experimental, +and will almost certainly change in incompatible ways in future +releases. @end table @item -fgnu89-inline diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c index 2ec3449a190..0a61d148c8a 100644 --- a/gcc/dwarf2out.c +++ b/gcc/dwarf2out.c @@ -24492,6 +24492,10 @@ static char *producer_string; static const char * highest_c_language (const char *lang1, const char *lang2) { + if (strcmp ("GNU C++23", lang1) == 0 || strcmp ("GNU C++23", lang2) == 0) + return "GNU C++23"; + if (strcmp ("GNU C++20", lang1) == 0 || strcmp ("GNU C++20", lang2) == 0) + return "GNU C++20"; if (strcmp ("GNU C++17", lang1) == 0 || strcmp ("GNU C++17", lang2) == 0) return "GNU C++17"; if (strcmp ("GNU C++14", lang1) == 0 || strcmp ("GNU C++14", lang2) == 0) @@ -24597,7 +24601,8 @@ gen_compile_unit_die (const char *filename) else if (strcmp (language_string, "GNU C++14") == 0) language = DW_LANG_C_plus_plus_14; else if (strcmp (language_string, "GNU C++17") == 0 - || strcmp (language_string, "GNU C++20") == 0) + || strcmp (language_string, "GNU C++20") == 0 + || strcmp (language_string, "GNU C++23") == 0) /* For now. */ language = DW_LANG_C_plus_plus_14; } diff --git a/gcc/testsuite/g++.dg/cpp23/cplusplus.C b/gcc/testsuite/g++.dg/cpp23/cplusplus.C new file mode 100644 index 00000000000..29a941bc758 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp23/cplusplus.C @@ -0,0 +1,4 @@ +// { dg-do compile } +// { dg-options "-std=c++23" } + +static_assert(__cplusplus > 202002L); diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp index 0d351c8fbad..af46c779214 100644 --- a/gcc/testsuite/lib/target-supports.exp +++ b/gcc/testsuite/lib/target-supports.exp @@ -9503,7 +9503,10 @@ proc check_effective_target_c++2a_only { } { return 0 } proc check_effective_target_c++2a { } { - return [check_effective_target_c++2a_only] + if [check_effective_target_c++2a_only] { + return 1 + } + return [check_effective_target_c++23] } proc check_effective_target_c++20_only { } { @@ -9513,6 +9516,29 @@ proc check_effective_target_c++20_only { } { proc check_effective_target_c++20 { } { return [check_effective_target_c++2a] } +proc check_effective_target_c++20_down { } { + if ![check_effective_target_c++] { + return 0 + } + return [expr ![check_effective_target_c++23] ] +} + +proc check_effective_target_c++23_only { } { + global cxx_default + if ![check_effective_target_c++] { + return 0 + } + if [check-flags { { } { } { -std=c++23 -std=gnu++23 -std=c++2b -std=gnu++2b } }] { + return 1 + } + if { $cxx_default == "c++23" && [check-flags { { } { } { } { -std=* } }] } { + return 1 + } + return 0 +} +proc check_effective_target_c++23 { } { + return [check_effective_target_c++23_only] +} # Check for C++ Concepts support, i.e. -fconcepts flag. proc check_effective_target_concepts { } { diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h index bcc50ba45f6..4467c73284d 100644 --- a/libcpp/include/cpplib.h +++ b/libcpp/include/cpplib.h @@ -173,7 +173,8 @@ enum c_lang {CLK_GNUC89 = 0, CLK_GNUC99, CLK_GNUC11, CLK_GNUC17, CLK_GNUC2X, CLK_STDC2X, CLK_GNUCXX, CLK_CXX98, CLK_GNUCXX11, CLK_CXX11, CLK_GNUCXX14, CLK_CXX14, CLK_GNUCXX17, CLK_CXX17, - CLK_GNUCXX20, CLK_CXX20, CLK_ASM}; + CLK_GNUCXX20, CLK_CXX20, CLK_GNUCXX23, CLK_CXX23, + CLK_ASM}; /* Payload of a NUMBER, STRING, CHAR or COMMENT token. */ struct GTY(()) cpp_string { diff --git a/libcpp/init.c b/libcpp/init.c index a5103c4d454..ecd3d5be7fd 100644 --- a/libcpp/init.c +++ b/libcpp/init.c @@ -119,6 +119,8 @@ static const struct lang_flags lang_defaults[] = /* CXX17 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0 }, /* GNUCXX20 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0 }, /* CXX20 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0 }, + /* GNUCXX23 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0 }, + /* CXX23 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0 }, /* ASM */ { 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } }; @@ -540,7 +542,12 @@ cpp_init_builtins (cpp_reader *pfile, int hosted) if (CPP_OPTION (pfile, cplusplus)) { - if (CPP_OPTION (pfile, lang) == CLK_CXX20 + /* C++23 is not yet a standard. For now, use an invalid + * year/month, 202100L, which is larger than 202002L. */ + if (CPP_OPTION (pfile, lang) == CLK_CXX23 + || CPP_OPTION (pfile, lang) == CLK_GNUCXX23) + _cpp_define_builtin (pfile, "__cplusplus 202100L"); + else if (CPP_OPTION (pfile, lang) == CLK_CXX20 || CPP_OPTION (pfile, lang) == CLK_GNUCXX20) _cpp_define_builtin (pfile, "__cplusplus 202002L"); else if (CPP_OPTION (pfile, lang) == CLK_CXX17 -- 2.30.2