Hi! The following patch adds a new -std= option arguments for C++29 and changes __cplusplus value for C++26 from 202400L to 202603L.
Ok for trunk? 2026-06-12 Jakub Jelinek <[email protected]> gcc/ * doc/invoke.texi (-std=c++2d, -std=c++29, -std=gnu++2d, -std=gnu++29): Document. * doc/cpp.texi: Adjust expected __cplusplus value for -std=c++26, document value for -std=c++29. * dwarf2out.cc (highest_c_language): Handle C++29. (gen_compile_unit_die): Likewise. Adjust lversion for C++26. gcc/c-family/ * c-common.h (enum cxx_dialect): Add cxx29. * c-opts.cc (set_std_cxx29): New function. (c_common_handle_option): Handle -std=c++2d, -std=c++29, -std=gnu++2d and -std=gnu++29. * c.opt (std=c++2d, std=c++29, std=gnu++2d, std=gnu++29): New. gcc/testsuite/ * g++.dg/cpp26/cplusplus.C: Expect __cplusplus == 202603L. * g++.dg/cpp29/cplusplus.C: New test. * g++.dg/cpp29/feat-cxx29.C: New test. * lib/target-supports.exp (check_effective_target_c++26): Also true for C++29. (check_effective_target_c++26_down, check_effective_target_c++29_only, check_effective_target_c++29): New procedures. * lib/g++-dg.exp (g++-std-flags): Add 29 to the list too. libcpp/ * include/cpplib.h (enum c_lang): Add CLK_GNUCXX29 and CLK_CXX29. * init.cc (lang_defaults): Add CLK_GNUCXX29 and CLK_CXX29 row. (cpp_init_builtins): Change __cplusplus value for C++26 from 202400L to 202603L and set __cplusplus value for C++29 to 202700L. --- gcc/c-family/c-common.h.jj 2026-06-05 10:39:31.134351137 +0200 +++ gcc/c-family/c-common.h 2026-06-12 17:00:25.426903046 +0200 @@ -751,7 +751,9 @@ enum cxx_dialect { /* C++23 */ cxx23, /* C++26 */ - cxx26 + cxx26, + /* C++29 */ + cxx29 }; /* The C++ dialect being used. C++20 is the default. */ --- gcc/c-family/c-opts.cc.jj 2026-05-30 17:45:09.345110280 +0200 +++ gcc/c-family/c-opts.cc 2026-06-12 17:25:31.330852780 +0200 @@ -118,6 +118,7 @@ static void set_std_cxx17 (int); static void set_std_cxx20 (int); static void set_std_cxx23 (int); static void set_std_cxx26 (int); +static void set_std_cxx29 (int); static void set_std_c89 (int, int); static void set_std_c99 (int); static void set_std_c11 (int); @@ -701,6 +702,12 @@ c_common_handle_option (size_t scode, co set_std_cxx26 (code == OPT_std_c__26 /* ISO */); break; + case OPT_std_c__29: + case OPT_std_gnu__29: + if (!preprocessing_asm_p) + set_std_cxx29 (code == OPT_std_c__29 /* ISO */); + break; + case OPT_std_c90: case OPT_std_iso9899_199409: if (!preprocessing_asm_p) @@ -2095,6 +2102,22 @@ set_std_cxx26 (int iso) lang_hooks.name = "GNU C++26"; } +/* Set the C++ 2029 standard (without GNU extensions if ISO). */ +static void +set_std_cxx29 (int iso) +{ + cpp_set_lang (parse_in, iso ? CLK_CXX29 : CLK_GNUCXX29); + flag_no_gnu_keywords = iso; + flag_no_nonansi_builtin = iso; + flag_iso = iso; + /* C++29 includes the C11 standard library. */ + flag_isoc94 = 1; + flag_isoc99 = 1; + flag_isoc11 = 1; + cxx_dialect = cxx29; + lang_hooks.name = "GNU C++29"; +} + /* Args to -d specify what to dump. Silently ignore unrecognized options; they may be aimed at toplev.cc. */ static void --- gcc/c-family/c.opt.jj 2026-06-01 09:15:39.010605683 +0200 +++ gcc/c-family/c.opt 2026-06-12 17:05:03.744184261 +0200 @@ -2676,6 +2676,14 @@ std=c++26 C++ ObjC++ Undocumented Conform to the ISO 2026 C++ draft standard (experimental and incomplete support). +std=c++2d +C++ ObjC++ Alias(std=c++29) +Conform to the ISO 2029 C++ draft standard (experimental and incomplete support). + +std=c++29 +C++ ObjC++ Undocumented +Conform to the ISO 2029 C++ draft standard (experimental and incomplete support). + std=c11 C ObjC Conform to the ISO 2011 C standard. @@ -2778,6 +2786,14 @@ std=gnu++26 C++ ObjC++ Undocumented Conform to the ISO 2026 C++ draft standard with GNU extensions (experimental and incomplete support). +std=gnu++2d +C++ ObjC++ Alias(std=gnu++29) +Conform to the ISO 2029 C++ draft standard with GNU extensions (experimental and incomplete support). + +std=gnu++29 +C++ ObjC++ Undocumented +Conform to the ISO 2029 C++ draft standard with GNU extensions (experimental and incomplete support). + std=gnu11 C ObjC Conform to the ISO 2011 C standard with GNU extensions. --- gcc/doc/invoke.texi.jj 2026-06-10 17:42:21.458938285 +0200 +++ gcc/doc/invoke.texi 2026-06-12 17:27:00.453670490 +0200 @@ -2648,6 +2648,18 @@ change in incompatible ways in future re GNU dialect of @option{-std=c++2c}. Support is highly experimental, and will almost certainly change in incompatible ways in future releases. + +@item c++2d +@itemx c++29 +The upcoming revision of the ISO C++ standard, planned for +2029. Support is highly experimental, and will almost certainly +change in incompatible ways in future releases. + +@item gnu++2d +@itemx gnu++29 +GNU dialect of @option{-std=c++2d}. Support is highly experimental, +and will almost certainly change in incompatible ways in future +releases. @end table @opindex aux-info --- gcc/doc/cpp.texi.jj 2026-06-09 10:19:34.527847828 +0200 +++ gcc/doc/cpp.texi 2026-06-12 17:08:35.300367120 +0200 @@ -1912,9 +1912,10 @@ selected, the value of the macro is @code{201703L} for the 2017 C++ standard, @code{202002L} for the 2020 C++ standard, @code{202302L} for the 2023 C++ standard, -or an unspecified value strictly larger than @code{202302L} for the -experimental languages enabled by @option{-std=c++26} and -@option{-std=gnu++26}. +@code{202603L} for the 2026 C++ standard, +or an unspecified value strictly larger than @code{202603L} for the +experimental languages enabled by @option{-std=c++29} and +@option{-std=gnu++29}. @item __OBJC__ This macro is defined, with value 1, when the Objective-C compiler is in --- gcc/testsuite/g++.dg/cpp26/cplusplus.C.jj 2026-03-27 10:17:15.650306001 +0100 +++ gcc/testsuite/g++.dg/cpp26/cplusplus.C 2026-06-12 17:15:00.831233282 +0200 @@ -1,3 +1,3 @@ // { dg-do compile { target c++26_only } } -static_assert(__cplusplus > 202302L); +static_assert(__cplusplus == 202603L); --- gcc/testsuite/g++.dg/cpp29/cplusplus.C.jj 2026-06-12 17:15:32.774807913 +0200 +++ gcc/testsuite/g++.dg/cpp29/cplusplus.C 2026-06-12 17:16:32.290015391 +0200 @@ -0,0 +1,3 @@ +// { dg-do compile { target c++29_only } } + +static_assert(__cplusplus > 202603L); --- gcc/testsuite/g++.dg/cpp29/feat-cxx29.C.jj 2026-06-12 17:15:48.882593418 +0200 +++ gcc/testsuite/g++.dg/cpp29/feat-cxx29.C 2026-06-12 17:16:03.543398189 +0200 @@ -0,0 +1,660 @@ +// { dg-options "-std=c++29 -I${srcdir}/g++.dg/cpp1y -I${srcdir}/g++.dg/cpp1y/testinc" } +// { dg-skip-if "requires hosted libstdc++ for complex" { ! hostedlib } } + +// C++98 features: + +#ifndef __cpp_rtti +# error "__cpp_rtti" +#elif __cpp_rtti != 199711 +# error "__cpp_rtti != 199711" +#endif + +#ifndef __cpp_exceptions +# error "__cpp_exceptions" +#elif __cpp_exceptions != 199711 +# error "__cpp_exceptions != 199711" +#endif + +// C++11 features: + +#ifndef __cpp_raw_strings +# error "__cpp_raw_strings" +#elif __cpp_raw_strings != 200710 +# error "__cpp_raw_strings != 200710" +#endif + +#ifndef __cpp_unicode_literals +# error "__cpp_unicode_literals" +#elif __cpp_unicode_literals != 200710 +# error "__cpp_unicode_literals != 200710" +#endif + +#ifndef __cpp_user_defined_literals +# error "__cpp_user_defined_literals" +#elif __cpp_user_defined_literals != 200809 +# error "__cpp_user_defined_literals != 200809" +#endif + +#ifndef __cpp_lambdas +# error "__cpp_lambdas" +#elif __cpp_lambdas != 200907 +# error "__cpp_lambdas != 200907" +#endif + +#ifndef __cpp_range_based_for +# error "__cpp_range_based_for" +#elif __cpp_range_based_for != 202211 +# error "__cpp_range_based_for != 202211" +#endif + +#ifndef __cpp_decltype +# error "__cpp_decltype" +#elif __cpp_decltype != 200707 +# error "__cpp_decltype != 200707" +#endif + +#ifndef __cpp_attributes +# error "__cpp_attributes" +#elif __cpp_attributes != 200809 +# error "__cpp_attributes != 200809" +#endif + +#ifndef __cpp_rvalue_references +# error "__cpp_rvalue_references" +#elif __cpp_rvalue_references != 200610 +# error "__cpp_rvalue_references != 200610" +#endif + +#ifndef __cpp_variadic_templates +# error "__cpp_variadic_templates" +#elif __cpp_variadic_templates != 200704 +# error "__cpp_variadic_templates != 200704" +#endif + +#ifndef __cpp_initializer_lists +# error "__cpp_initializer_lists" +#elif __cpp_initializer_lists != 200806 +# error "__cpp_initializer_lists != 200806" +#endif + +#ifndef __cpp_delegating_constructors +# error "__cpp_delegating_constructors" +#elif __cpp_delegating_constructors != 200604 +# error "__cpp_delegating_constructors != 200604" +#endif + +#ifndef __cpp_nsdmi +# error "__cpp_nsdmi" +#elif __cpp_nsdmi != 200809 +# error "__cpp_nsdmi != 200809" +#endif + +#ifndef __cpp_inheriting_constructors +# error "__cpp_inheriting_constructors" +#elif __cpp_inheriting_constructors!= 201511 +# error "__cpp_inheriting_constructors != 201511" +#endif + +#ifndef __cpp_ref_qualifiers +# error "__cpp_ref_qualifiers" +#elif __cpp_ref_qualifiers != 200710 +# error "__cpp_ref_qualifiers != 200710" +#endif + +#ifndef __cpp_alias_templates +# error "__cpp_alias_templates" +#elif __cpp_alias_templates != 200704 +# error "__cpp_alias_templates != 200704" +#endif + +#ifndef __cpp_threadsafe_static_init +# error "__cpp_threadsafe_static_init" +#elif __cpp_threadsafe_static_init != 200806 +# error "__cpp_threadsafe_static_init != 200806" +#endif + +// C++14 features: + +#ifndef __cpp_binary_literals +# error "__cpp_binary_literals" +#elif __cpp_binary_literals != 201304 +# error "__cpp_binary_literals != 201304" +#endif + +#ifndef __cpp_init_captures +# error "__cpp_init_captures" +#elif __cpp_init_captures != 201803 +# error "__cpp_init_captures != 201803" +#endif + +#ifndef __cpp_generic_lambdas +# error "__cpp_generic_lambdas" +#elif __cpp_generic_lambdas != 201707 +# error "__cpp_generic_lambdas != 201707" +#endif + +#ifndef __cpp_constexpr +# error "__cpp_constexpr" +#elif __cpp_constexpr != 202406L +# error "__cpp_constexpr != 202406L" +#endif + +#ifndef __cpp_decltype_auto +# error "__cpp_decltype_auto" +#elif __cpp_decltype_auto != 201304 +# error "__cpp_decltype_auto != 201304" +#endif + +#ifndef __cpp_return_type_deduction +# error "__cpp_return_type_deduction" +#elif __cpp_return_type_deduction != 201304 +# error "__cpp_return_type_deduction != 201304" +#endif + +#ifndef __cpp_aggregate_nsdmi +# error "__cpp_aggregate_nsdmi" +#elif __cpp_aggregate_nsdmi != 201304 +# error "__cpp_aggregate_nsdmi != 201304" +#endif + +#ifndef __cpp_variable_templates +# error "__cpp_variable_templates" +#elif __cpp_variable_templates != 201304 +# error "__cpp_variable_templates != 201304" +#endif + +#ifndef __cpp_digit_separators +# error "__cpp_digit_separators" +#elif __cpp_digit_separators != 201309 +# error "__cpp_digit_separators != 201309" +#endif + +#ifndef __cpp_sized_deallocation +# error "__cpp_sized_deallocation" +#elif __cpp_sized_deallocation != 201309 +# error "__cpp_sized_deallocation != 201309" +#endif + +// GNU VLA support: + +#ifndef __cpp_runtime_arrays +# error "__cpp_runtime_arrays" +#elif __cpp_runtime_arrays != 198712 +# error "__cpp_runtime_arrays != 198712" +#endif + +// C++11 attributes: + +#ifdef __has_cpp_attribute +# if ! __has_cpp_attribute(noreturn) +# error "__has_cpp_attribute(noreturn)" +# elif __has_cpp_attribute(noreturn) != 200809 +# error "__has_cpp_attribute(noreturn) != 200809" +# endif +#else +# error "__has_cpp_attribute" +#endif + +// Attribute carries_dependency not in yet. +//#ifdef __has_cpp_attribute +//# if ! __has_cpp_attribute(carries_dependency) +//# error "__has_cpp_attribute(carries_dependency)" +//# elif __has_cpp_attribute(carries_dependency) != 200809 +//# error "__has_cpp_attribute(carries_dependency) != 200809" +//# endif +//#else +//# error "__has_cpp_attribute" +//#endif + +// C++14 attributes: + +#ifdef __has_cpp_attribute +# if ! __has_cpp_attribute(deprecated) +# error "__has_cpp_attribute(deprecated)" +# elif __has_cpp_attribute(deprecated) != 201309 +# error "__has_cpp_attribute(deprecated) != 201309" +# endif +#else +# error "__has_cpp_attribute" +#endif + +// Include checks: + +// Check for __has_include macro. +#ifndef __has_include +# error "__has_include" +#endif + +// Try known bracket header (use operator). +#if __has_include (<complex>) +#else +# error "<complex>" +#endif + +// Define and use a macro to invoke the operator. +#define sluggo(TXT) __has_include(TXT) + +#if sluggo(<complex>) +#else +# error "<complex>" +#endif + +#if ! sluggo(<complex>) +# error "<complex>" +#else +#endif + +// Quoted complex.h should find at least the bracket version. +#if __has_include("complex.h") +#else +# error "complex.h" +#endif + +// Try known local quote header. +#if __has_include("complex_literals.h") +#else +# error "\"complex_literals.h\"" +#endif + +// Try nonexistent bracket header. +#if __has_include(<stuff>) +# error "<stuff>" +#else +#endif + +// Try nonexistent quote header. +#if __has_include("phlegm") +# error "\"phlegm\"" +#else +#endif + +// Test __has_include_next. +#if __has_include("phoobhar.h") +# include "phoobhar.h" +#else +# error "__has_include(\"phoobhar.h\")" +#endif + +// Try a macro. +#define COMPLEX_INC "complex.h" +#if __has_include(COMPLEX_INC) +#else +# error COMPLEX_INC +#endif + +// Realistic use of __has_include. +#if __has_include(<array>) +# define STD_ARRAY 1 +# include <array> + template<typename _Tp, std::size_t _Num> + using array = std::array<_Tp, _Num>; +#elif __has_include(<tr1/array>) +# define TR1_ARRAY 1 +# include <tr1/array> + template<typename _Tp, std::size_t _Num> + typedef std::tr1::array<_Tp, _Num> array; +#endif + +// C++17 features: + +#ifndef __cpp_unicode_characters +# error "__cpp_unicode_characters" +#elif __cpp_unicode_characters != 201411 +# error "__cpp_unicode_characters != 201411" +#endif + +#ifndef __cpp_static_assert +# error "__cpp_static_assert" +#elif __cpp_static_assert != 202306 +# error "__cpp_static_assert != 202306" +#endif + +#ifndef __cpp_namespace_attributes +# error "__cpp_namespace_attributes" +#elif __cpp_namespace_attributes != 201411 +# error "__cpp_namespace_attributes != 201411" +#endif + +#ifndef __cpp_enumerator_attributes +# error "__cpp_enumerator_attributes" +#elif __cpp_enumerator_attributes != 201411 +# error "__cpp_enumerator_attributes != 201411" +#endif + +#ifndef __cpp_nested_namespace_definitions +# error "__cpp_nested_namespace_definitions" +#elif __cpp_nested_namespace_definitions != 201411 +# error "__cpp_nested_namespace_definitions != 201411" +#endif + +#ifndef __cpp_fold_expressions +# error "__cpp_fold_expressions" +#elif __cpp_fold_expressions != 201603 +# error "__cpp_fold_expressions != 201603" +#endif + +#ifndef __cpp_nontype_template_args +# error "__cpp_nontype_template_args" +#elif __cpp_nontype_template_args != 201911 +# error "__cpp_nontype_template_args != 201911" +#endif + +#ifndef __cpp_hex_float +# error "__cpp_hex_float" +#elif __cpp_hex_float != 201603 +# error "__cpp_hex_float != 201603" +#endif + +#ifndef __cpp_aggregate_bases +# error "__cpp_aggregate_bases" +#elif __cpp_aggregate_bases != 201603 +# error "__cpp_aggregate_bases != 201603" +#endif + +#ifndef __cpp_deduction_guides +# error "__cpp_deduction_guides" +#elif __cpp_deduction_guides != 202207 +# error "__cpp_deduction_guides != 202207" +#endif + +#ifndef __cpp_if_constexpr +# error "__cpp_if_constexpr" +#elif __cpp_if_constexpr != 201606 +# error "__cpp_if_constexpr != 201606" +#endif + +#ifndef __cpp_aligned_new +# error "__cpp_aligned_new" +#elif __cpp_aligned_new != 201606 +# error "__cpp_aligned_new != 201606" +#endif + +#ifndef __cpp_template_auto +# error "__cpp_template_auto" +#elif __cpp_template_auto != 201606 +# error "__cpp_template_auto != 201606" +#endif + +#ifndef __cpp_inline_variables +# error "__cpp_inline_variables" +#elif __cpp_inline_variables != 201606 +# error "__cpp_inline_variables != 201606" +#endif + +#ifndef __cpp_capture_star_this +# error "__cpp_capture_star_this" +#elif __cpp_capture_star_this != 201603 +# error "__cpp_capture_star_this != 201603" +#endif + +#ifndef __cpp_noexcept_function_type +# error "__cpp_noexcept_function_type" +#elif __cpp_noexcept_function_type != 201510 +# error "__cpp_noexcept_function_type != 201510" +#endif + +#ifndef __cpp_structured_bindings +# error "__cpp_structured_bindings" +#elif __cpp_structured_bindings != 202411 +# error "__cpp_structured_bindings != 202411" +#endif + +#ifndef __cpp_template_template_args +# error "__cpp_template_template_args" +#elif __cpp_template_template_args != 201611 +# error "__cpp_template_template_args != 201611" +#endif + +#ifndef __cpp_variadic_using +# error "__cpp_variadic_using" +#elif __cpp_variadic_using != 201611 +# error "__cpp_variadic_using != 201611" +#endif + +#ifndef __cpp_guaranteed_copy_elision +# error "__cpp_guaranteed_copy_elision" +#elif __cpp_guaranteed_copy_elision != 201606 +# error "__cpp_guaranteed_copy_elision != 201606" +#endif + +#ifndef __cpp_nontype_template_parameter_auto +# error "__cpp_nontype_template_parameter_auto" +#elif __cpp_nontype_template_parameter_auto != 201606 +# error "__cpp_nontype_template_parameter_auto != 201606" +#endif + +// C++20 features: + +#ifndef __cpp_conditional_explicit +# error "__cpp_conditional_explicit" +#elif __cpp_conditional_explicit != 201806 +# error "__cpp_conditional_explicit != 201806" +#endif + +#ifndef __cpp_nontype_template_parameter_class +# error "__cpp_nontype_template_parameter_class" +#elif __cpp_nontype_template_parameter_class != 201806 +# error "__cpp_nontype_template_parameter_class != 201806" +#endif + +#ifndef __cpp_impl_destroying_delete +# error "__cpp_impl_destroying_delete" +#elif __cpp_impl_destroying_delete != 201806 +# error "__cpp_impl_destroying_delete != 201806" +#endif + +#ifndef __cpp_constinit +# error "__cpp_constinit" +#elif __cpp_constinit != 201907 +# error "__cpp_constinit != 201907" +#endif + +#ifndef __cpp_constexpr_dynamic_alloc +# error "__cpp_constexpr_dynamic_alloc" +#elif __cpp_constexpr_dynamic_alloc != 201907 +# error "__cpp_constexpr_dynamic_alloc != 201907" +#endif + +#ifndef __cpp_aggregate_paren_init +# error "__cpp_aggregate_paren_init" +#elif __cpp_aggregate_paren_init != 201902 +# error "__cpp_aggregate_paren_init != 201902" +#endif + +#ifndef __cpp_char8_t +# error "__cpp_char8_t" +#elif __cpp_char8_t != 202207 +# error "__cpp_char8_t != 202207" +#endif + +#ifndef __cpp_designated_initializers +# error "__cpp_designated_initializers" +#elif __cpp_designated_initializers != 201707 +# error "__cpp_designated_initializers != 201707" +#endif + +#ifndef __cpp_constexpr_in_decltype +# error "__cpp_constexpr_in_decltype" +#elif __cpp_constexpr_in_decltype != 201711 +# error "__cpp_constexpr_in_decltype != 201711" +#endif + +#ifndef __cpp_consteval +# error "__cpp_consteval" +#elif __cpp_consteval != 202211L +# error "__cpp_consteval != 202211L" +#endif + +#ifndef __cpp_concepts +# error "__cpp_concepts" +#elif __cpp_concepts != 202002 +# error "__cpp_concepts != 202002" +#endif + +#ifndef __cpp_using_enum +# error "__cpp_using_enum" +#elif __cpp_using_enum != 201907 +# error "__cpp_using_enum != 201907" +#endif + +// C++20 attributes: + +#ifdef __has_cpp_attribute + +# if ! __has_cpp_attribute(maybe_unused) +# error "__has_cpp_attribute(maybe_unused)" +# elif __has_cpp_attribute(maybe_unused) != 201603 +# error "__has_cpp_attribute(maybe_unused) != 201603" +# endif + +# if ! __has_cpp_attribute(nodiscard) +# error "__has_cpp_attribute(nodiscard)" +# elif __has_cpp_attribute(nodiscard) != 201907 +# error "__has_cpp_attribute(nodiscard) != 201907" +# endif + +# if ! __has_cpp_attribute(fallthrough) +# error "__has_cpp_attribute(fallthrough)" +# elif __has_cpp_attribute(fallthrough) != 201603 +# error "__has_cpp_attribute(fallthrough) != 201603" +# endif + +# if ! __has_cpp_attribute(no_unique_address) +# error "__has_cpp_attribute(no_unique_address)" +# elif __has_cpp_attribute(no_unique_address) != 201803 +# error "__has_cpp_attribute(no_unique_address) != 201803" +# endif + +# if ! __has_cpp_attribute(likely) +# error "__has_cpp_attribute(likely)" +# elif __has_cpp_attribute(likely) != 201803 +# error "__has_cpp_attribute(likely) != 201803" +# endif + +# if ! __has_cpp_attribute(unlikely) +# error "__has_cpp_attribute(unlikely)" +# elif __has_cpp_attribute(unlikely) != 201803 +# error "__has_cpp_attribute(unlikely) != 201803" +# endif + +#else +# error "__has_cpp_attribute" +#endif + +// C++23 features: + +#ifndef __cpp_size_t_suffix +# error "__cpp_size_t_suffix" +#elif __cpp_size_t_suffix != 202011 +# error "__cpp_size_t_suffix != 202011" +#endif + +#ifndef __cpp_if_consteval +# error "__cpp_if_consteval" +#elif __cpp_if_consteval != 202106 +# error "__cpp_if_consteval != 202106" +#endif + +#ifndef __cpp_multidimensional_subscript +# error "__cpp_multidimensional_subscript" +#elif __cpp_multidimensional_subscript != 202211 +# error "__cpp_multidimensional_subscript != 202211" +#endif + +#ifndef __cpp_named_character_escapes +# error "__cpp_named_character_escapes" +#elif __cpp_named_character_escapes != 202207 +# error "__cpp_named_character_escapes != 202207" +#endif + +#ifndef __cpp_static_call_operator +# error "__cpp_static_call_operator" +#elif __cpp_static_call_operator != 202207 +# error "__cpp_static_call_operator != 202207" +#endif + +#ifndef __cpp_implicit_move +# error "__cpp_implicit_move" +#elif __cpp_implicit_move != 202207 +# error "__cpp_implicit_move != 202207" +#endif + +#ifndef __cpp_explicit_this_parameter +# error "__cpp_explicit_this_parameter" +#elif __cpp_explicit_this_parameter != 202110 +# error "__cpp_explicit_this_parameter != 202110" +#endif + +#ifndef __cpp_auto_cast +# error "__cpp_auto_cast" +#elif __cpp_auto_cast != 202110 +# error "__cpp_auto_cast != 202110" +#endif + +// C++23 attributes: + +#ifdef __has_cpp_attribute +# if ! __has_cpp_attribute(assume) +# error "__has_cpp_attribute(assume)" +# elif __has_cpp_attribute(assume) != 202207 +# error "__has_cpp_attribute(assume) != 202207" +# endif +#else +# error "__has_cpp_attribute" +#endif + +// C++26 features: + +#ifndef __cpp_placeholder_variables +# error "__cpp_placeholder_variables" +#elif __cpp_placeholder_variables != 202306 +# error "__cpp_placeholder_variables != 202306" +#endif + +#ifndef __cpp_deleted_function +# error "__cpp_deleted_function" +#elif __cpp_deleted_function != 202403 +# error "__cpp_deleted_function != 202403" +#endif + +#ifndef __cpp_variadic_friend +# error "__cpp_variadic_friend" +#elif __cpp_variadic_friend != 202403 +# error "__cpp_variadic_friend != 202403" +#endif + +#ifndef __cpp_pack_indexing +# error "__cpp_pack_indexing" +#elif __cpp_pack_indexing != 202311 +# error "__cpp_pack_indexing != 202311" +#endif + +#ifndef __cpp_pp_embed +# error "__cpp_pp_embed" +#elif __cpp_pp_embed != 202502 +# error "__cpp_pp_embed != 202502" +#endif + +#ifndef __cpp_constexpr_virtual_inheritance +# error "__cpp_constexpr_virtual_inheritance" +#elif __cpp_constexpr_virtual_inheritance != 202506 +# error "__cpp_constexpr_virtual_inheritance != 202506" +#endif + +#ifndef __cpp_constexpr_exceptions +# error "__cpp_constexpr_exceptions" +#elif __cpp_constexpr_exceptions != 202411 +# error "__cpp_constexpr_exceptions != 202411" +#endif + +#ifndef __cpp_expansion_statements +# error "__cpp_expansion_statements" +#elif __cpp_expansion_statements != 202506 +# error "__cpp_expansion_statements != 202506" +#endif + +#ifndef __cpp_trivial_union +# error "__cpp_trivial_union" +#elif __cpp_trivial_union != 202502 +# error "__cpp_trivial_union != 202502" +#endif --- gcc/testsuite/lib/target-supports.exp.jj 2026-06-12 16:55:06.698171156 +0200 +++ gcc/testsuite/lib/target-supports.exp 2026-06-12 17:20:44.359659689 +0200 @@ -12540,7 +12540,35 @@ proc check_effective_target_c++26_only { } proc check_effective_target_c++26 { } { - return [check_effective_target_c++26_only] + if [check_effective_target_c++26_only] { + return 1 + } + return [check_effective_target_c++29] +} + +proc check_effective_target_c++26_down { } { + if ![check_effective_target_c++] { + return 0 + } + return [expr ![check_effective_target_c++29] ] +} + +proc check_effective_target_c++29_only { } { + global cxx_default + if ![check_effective_target_c++] { + return 0 + } + if [check-flags { { } { } { -std=c++29 -std=gnu++29 -std=c++2d -std=gnu++2d } }] { + return 1 + } + if { $cxx_default == "c++29" && [check-flags { { } { } { } { -std=* } }] } { + return 1 + } + return 0 +} + +proc check_effective_target_c++29 { } { + return [check_effective_target_c++29_only] } # Check for C++ Concepts support, i.e. -fconcepts flag. --- gcc/testsuite/lib/g++-dg.exp.jj 2026-03-27 10:17:21.308213672 +0100 +++ gcc/testsuite/lib/g++-dg.exp 2026-06-12 17:21:41.122906679 +0200 @@ -78,7 +78,7 @@ proc g++-std-flags { test } { # The order of this list is significant: first $cxx_default, # then the oldest and newest, then others in rough order of # importance based on test coverage and usage. - foreach ver { 20 98 26 17 11 14 23 } { + foreach ver { 20 98 26 17 11 14 23 29 } { set cmpver $ver if { $ver == 98 } { set cmpver 03 } if { [llength $std_list] < 3 --- gcc/dwarf2out.cc.jj 2026-05-30 17:45:09.404109533 +0200 +++ gcc/dwarf2out.cc 2026-06-12 17:13:54.895111309 +0200 @@ -25640,6 +25640,8 @@ static char *producer_string; static const char * highest_c_language (const char *lang1, const char *lang2) { + if (strcmp ("GNU C++29", lang1) == 0 || strcmp ("GNU C++29", lang2) == 0) + return "GNU C++29"; if (strcmp ("GNU C++26", lang1) == 0 || strcmp ("GNU C++26", lang2) == 0) return "GNU C++26"; if (strcmp ("GNU C++23", lang1) == 0 || strcmp ("GNU C++23", lang2) == 0) @@ -25794,7 +25796,13 @@ gen_compile_unit_die (const char *filena { language = DW_LANG_C_plus_plus_14; lname = DW_LNAME_C_plus_plus; - lversion = 202400; + lversion = 202603; + } + else if (strcmp (language_string, "GNU C++29") == 0) + { + language = DW_LANG_C_plus_plus_14; + lname = DW_LNAME_C_plus_plus; + lversion = 202700; } } } --- libcpp/include/cpplib.h.jj 2026-05-30 17:45:09.502108293 +0200 +++ libcpp/include/cpplib.h 2026-06-12 17:22:11.101508989 +0200 @@ -183,7 +183,8 @@ enum c_lang {CLK_GNUC89 = 0, CLK_GNUC99, CLK_GNUCXX, CLK_CXX98, CLK_GNUCXX11, CLK_CXX11, CLK_GNUCXX14, CLK_CXX14, CLK_GNUCXX17, CLK_CXX17, CLK_GNUCXX20, CLK_CXX20, CLK_GNUCXX23, CLK_CXX23, - CLK_GNUCXX26, CLK_CXX26, CLK_ASM}; + CLK_GNUCXX26, CLK_CXX26, CLK_GNUCXX29, CLK_CXX29, + CLK_ASM}; /* Payload of a NUMBER, STRING, CHAR or COMMENT token. */ struct GTY(()) cpp_string { --- libcpp/init.cc.jj 2026-03-27 10:17:21.566209462 +0100 +++ libcpp/init.cc 2026-06-12 17:23:29.230472545 +0200 @@ -151,6 +151,8 @@ static const struct lang_flags lang_defa /* CXX23 */ { 1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0,1,0,0,1 }, /* GNUCXX26 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0,1,1,0,1 }, /* CXX26 */ { 1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0,1,1,0,1 }, + /* GNUCXX29 */ { 1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0,1,1,0,1 }, + /* CXX29 */ { 1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,0,1,1,1,1,1,0,1,1,0,1 }, /* ASM */ { 0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } }; @@ -599,11 +601,14 @@ cpp_init_builtins (cpp_reader *pfile, in if (CPP_OPTION (pfile, cplusplus)) { - /* C++26 is not yet a standard. For now, use an invalid - year/month, 202400L, which is larger than 202302L. */ - if (CPP_OPTION (pfile, lang) == CLK_CXX26 - || CPP_OPTION (pfile, lang) == CLK_GNUCXX26) - _cpp_define_builtin (pfile, "__cplusplus 202400L"); + /* C++29 is not yet a standard. For now, use an invalid + year/month, 202700L, which is larger than 202603L. */ + if (CPP_OPTION (pfile, lang) == CLK_CXX29 + || CPP_OPTION (pfile, lang) == CLK_GNUCXX29) + _cpp_define_builtin (pfile, "__cplusplus 202700L"); + else if (CPP_OPTION (pfile, lang) == CLK_CXX26 + || CPP_OPTION (pfile, lang) == CLK_GNUCXX26) + _cpp_define_builtin (pfile, "__cplusplus 202603L"); else if (CPP_OPTION (pfile, lang) == CLK_CXX23 || CPP_OPTION (pfile, lang) == CLK_GNUCXX23) _cpp_define_builtin (pfile, "__cplusplus 202302L"); Jakub
