In r15-3714-gd3a7302ec5985a I added -Wsystem-headers to the libstdc++ build flags to help catch problems in the library. This patch takes a different approach, of disabling the #pragma system_header unless _GLIBCXX_SYSHDR is defined. As a result, the testsuites will treat them as non-system-headers to get better warning coverage during regression testing of both gcc and libstdc++, not just when building the library. My rationale for the #ifdef instead of just removing the #pragma is the three G++ tests that want to test libstdc++ system header behavior, so we need a way to select it. This doesn't affect installed libraries, as they get their system-header status from the lookup path. But testsuite_flags --build-includes gives -I directives rather than -isystem. This patch doesn't change the headers in config/ because I'm not compiling with most of them, so won't see any warnings that need fixing. Adjusting them could happen later, or we can not bother. libstdc++-v3/ChangeLog: * acinclude.m4 (WARN_FLAGS): Remove -Wsystem-headers. * configure: Regenerate. * include/bits/algorithmfwd.h: #ifdef out #pragma GCC system_header. * include/bits/atomic_base.h * include/bits/atomic_futex.h * include/bits/atomic_timed_wait.h * include/bits/atomic_wait.h * include/bits/basic_ios.h * include/bits/basic_string.h * include/bits/boost_concept_check.h * include/bits/char_traits.h * include/bits/charconv.h * include/bits/chrono.h * include/bits/chrono_io.h * include/bits/codecvt.h * include/bits/concept_check.h * include/bits/cpp_type_traits.h * include/bits/elements_of.h * include/bits/enable_special_members.h * include/bits/erase_if.h * include/bits/forward_list.h * include/bits/functional_hash.h * include/bits/gslice.h * include/bits/gslice_array.h * include/bits/hashtable.h * include/bits/indirect_array.h * include/bits/invoke.h * include/bits/ios_base.h * include/bits/iterator_concepts.h * include/bits/locale_classes.h * include/bits/locale_facets.h * include/bits/locale_facets_nonio.h * include/bits/localefwd.h * include/bits/mask_array.h * include/bits/max_size_type.h * include/bits/memory_resource.h * include/bits/memoryfwd.h * include/bits/move_only_function.h * include/bits/node_handle.h * include/bits/ostream_insert.h * include/bits/out_ptr.h * include/bits/parse_numbers.h * include/bits/postypes.h * include/bits/quoted_string.h * include/bits/range_access.h * include/bits/ranges_base.h * include/bits/refwrap.h * include/bits/sat_arith.h * include/bits/semaphore_base.h * include/bits/slice_array.h * include/bits/std_abs.h * include/bits/std_function.h * include/bits/std_mutex.h * include/bits/std_thread.h * include/bits/stl_iterator_base_funcs.h * include/bits/stl_iterator_base_types.h * include/bits/stl_tree.h * include/bits/stream_iterator.h * include/bits/streambuf_iterator.h * include/bits/stringfwd.h * include/bits/this_thread_sleep.h * include/bits/unique_lock.h * include/bits/uses_allocator_args.h * include/bits/utility.h * include/bits/valarray_after.h * include/bits/valarray_array.h * include/bits/valarray_before.h * include/bits/version.h * include/c_compatibility/fenv.h * include/c_compatibility/inttypes.h * include/c_compatibility/stdint.h * include/decimal/decimal.h * include/experimental/bits/net.h * include/experimental/bits/shared_ptr.h * include/ext/aligned_buffer.h * include/ext/alloc_traits.h * include/ext/atomicity.h * include/ext/concurrence.h * include/ext/numeric_traits.h * include/ext/pod_char_traits.h * include/ext/pointer.h * include/ext/stdio_filebuf.h * include/ext/stdio_sync_filebuf.h * include/ext/string_conversions.h * include/ext/type_traits.h * include/ext/vstring.h * include/ext/vstring_fwd.h * include/ext/vstring_util.h * include/parallel/algorithmfwd.h * include/parallel/numericfwd.h * include/tr1/functional_hash.h * include/tr1/hashtable.h * include/tr1/random.h * libsupc++/exception.h * libsupc++/hash_bytes.h * include/bits/basic_ios.tcc * include/bits/basic_string.tcc * include/bits/fstream.tcc * include/bits/istream.tcc * include/bits/locale_classes.tcc * include/bits/locale_facets.tcc * include/bits/locale_facets_nonio.tcc * include/bits/ostream.tcc * include/bits/sstream.tcc * include/bits/streambuf.tcc * include/bits/string_view.tcc * include/bits/version.tpl * include/experimental/bits/string_view.tcc * include/ext/pb_ds/detail/resize_policy/hash_prime_size_policy_imp.hpp * include/ext/random.tcc * include/ext/vstring.tcc * include/tr2/bool_set.tcc * include/tr2/dynamic_bitset.tcc * include/bits/c++config * include/c/cassert * include/c/cctype * include/c/cerrno * include/c/cfloat * include/c/ciso646 * include/c/climits * include/c/clocale * include/c/cmath * include/c/csetjmp * include/c/csignal * include/c/cstdarg * include/c/cstddef * include/c/cstdio * include/c/cstdlib * include/c/cstring * include/c/ctime * include/c/cuchar * include/c/cwchar * include/c/cwctype * include/c_global/cassert * include/c_global/ccomplex * include/c_global/cctype * include/c_global/cerrno * include/c_global/cfenv * include/c_global/cfloat * include/c_global/cinttypes * include/c_global/ciso646 * include/c_global/climits * include/c_global/clocale * include/c_global/cmath * include/c_global/csetjmp * include/c_global/csignal * include/c_global/cstdalign * include/c_global/cstdarg * include/c_global/cstdbool * include/c_global/cstddef * include/c_global/cstdint * include/c_global/cstdio * include/c_global/cstdlib * include/c_global/cstring * include/c_global/ctgmath * include/c_global/ctime * include/c_global/cuchar * include/c_global/cwchar * include/c_global/cwctype * include/c_std/cassert * include/c_std/cctype * include/c_std/cerrno * include/c_std/cfloat * include/c_std/ciso646 * include/c_std/climits * include/c_std/clocale * include/c_std/cmath * include/c_std/csetjmp * include/c_std/csignal * include/c_std/cstdarg * include/c_std/cstddef * include/c_std/cstdio * include/c_std/cstdlib * include/c_std/cstring * include/c_std/ctime * include/c_std/cuchar * include/c_std/cwchar * include/c_std/cwctype * include/debug/array * include/debug/bitset * include/debug/deque * include/debug/forward_list * include/debug/list * include/debug/map * include/debug/set * include/debug/string * include/debug/unordered_map * include/debug/unordered_set * include/debug/vector * include/decimal/decimal * include/experimental/algorithm * include/experimental/any * include/experimental/array * include/experimental/buffer * include/experimental/chrono * include/experimental/contract * include/experimental/deque * include/experimental/executor * include/experimental/filesystem * include/experimental/forward_list * include/experimental/functional * include/experimental/internet * include/experimental/io_context * include/experimental/iterator * include/experimental/list * include/experimental/map * include/experimental/memory * include/experimental/memory_resource * include/experimental/net * include/experimental/netfwd * include/experimental/numeric * include/experimental/propagate_const * include/experimental/ratio * include/experimental/regex * include/experimental/scope * include/experimental/set * include/experimental/socket * include/experimental/string * include/experimental/string_view * include/experimental/synchronized_value * include/experimental/system_error * include/experimental/timer * include/experimental/tuple * include/experimental/type_traits * include/experimental/unordered_map * include/experimental/unordered_set * include/experimental/vector * include/ext/algorithm * include/ext/cmath * include/ext/functional * include/ext/iterator * include/ext/memory * include/ext/numeric * include/ext/random * include/ext/rb_tree * include/ext/rope * include/parallel/algorithm * include/std/algorithm * include/std/any * include/std/array * include/std/atomic * include/std/barrier * include/std/bit * include/std/bitset * include/std/charconv * include/std/chrono * include/std/codecvt * include/std/complex * include/std/concepts * include/std/condition_variable * include/std/coroutine * include/std/deque * include/std/execution * include/std/expected * include/std/filesystem * include/std/format * include/std/forward_list * include/std/fstream * include/std/functional * include/std/future * include/std/generator * include/std/iomanip * include/std/ios * include/std/iosfwd * include/std/iostream * include/std/istream * include/std/iterator * include/std/latch * include/std/limits * include/std/list * include/std/locale * include/std/map * include/std/memory * include/std/memory_resource * include/std/mutex * include/std/numbers * include/std/numeric * include/std/optional * include/std/ostream * include/std/print * include/std/queue * include/std/random * include/std/ranges * include/std/ratio * include/std/regex * include/std/scoped_allocator * include/std/semaphore * include/std/set * include/std/shared_mutex * include/std/span * include/std/spanstream * include/std/sstream * include/std/stack * include/std/stacktrace * include/std/stdexcept * include/std/streambuf * include/std/string * include/std/string_view * include/std/syncstream * include/std/system_error * include/std/text_encoding * include/std/thread * include/std/tuple * include/std/type_traits * include/std/typeindex * include/std/unordered_map * include/std/unordered_set * include/std/utility * include/std/valarray * include/std/variant * include/std/vector * include/std/version * include/tr1/array * include/tr1/cfenv * include/tr1/cinttypes * include/tr1/cmath * include/tr1/complex * include/tr1/cstdbool * include/tr1/cstdint * include/tr1/cstdio * include/tr1/cstdlib * include/tr1/cwchar * include/tr1/cwctype * include/tr1/functional * include/tr1/memory * include/tr1/random * include/tr1/regex * include/tr1/tuple * include/tr1/type_traits * include/tr1/unordered_map * include/tr1/unordered_set * include/tr1/utility * include/tr2/bool_set * include/tr2/dynamic_bitset * include/tr2/type_traits * libsupc++/atomic_lockfree_defines.h * libsupc++/compare * libsupc++/cxxabi.h * libsupc++/cxxabi_forced.h * libsupc++/cxxabi_init_exception.h * libsupc++/exception * libsupc++/initializer_list * libsupc++/new * libsupc++/typeinfo: Likewise. * testsuite/20_util/ratio/operations/ops_overflow_neg.cc * testsuite/23_containers/array/tuple_interface/get_neg.cc * testsuite/23_containers/vector/cons/destructible_debug_neg.cc * testsuite/24_iterators/operations/prev_neg.cc * testsuite/ext/type_traits/add_unsigned_floating_neg.cc * testsuite/ext/type_traits/add_unsigned_integer_neg.cc * testsuite/ext/type_traits/remove_unsigned_floating_neg.cc * testsuite/ext/type_traits/remove_unsigned_integer_neg.cc: Adjust line numbers. gcc/testsuite/ChangeLog * g++.dg/analyzer/fanalyzer-show-events-in-system-headers-default.C * g++.dg/analyzer/fanalyzer-show-events-in-system-headers-no.C * g++.dg/diagnostic/disable.C: #define _GLIBCXX_SYSHDR.
Use strerror_r instead of strerror when available, due to the latter not being thread-safe. This is complicated by Glibc providing a GNU-specific strerror_r which is not compatible with POSIX strerror_r, so we need to dispatch on the return type. We can use the recently-added std::string::__resize_and_overwrite to write directly into the string buffer when possible. Because we estimate the initial buffer size we might end up with excess capacity in the returned std::string. We can slightly tweak the std::system_error constructors to make use of that excess capacity, so that in some cases we require fewer allocations to construct the std::system_error::what() string. libstdc++-v3/ChangeLog: PR libstdc++/110133 * include/std/system_error (system_error::system_error): Group arguments so that concatenation can reuse rvalue's capacity. * src/c++11/system_error.cc (strerror_string): New function. [_GLIBCXX_HAVE_STRERROR_R] (use_strerror_result): New functions. (generic_error_category::message): Use strerror_string. (system_error_category::message): Likewise.
PR libstdc++/103626 - _GLIBCXX_HOSTED should respect -ffreestanding Co-authored-by: Jonathan Wakely <jwakely@redhat.com> libstdc++-v3/ChangeLog: PR libstdc++/103626 * include/Makefile.am: Add new header. * include/Makefile.in: Regenerate. * include/bits/requires_hosted.h: New header. * include/experimental/algorithm: Include <bits/requires_hosted.h>. * include/experimental/any: Likewise. * include/experimental/array: Likewise. * include/experimental/buffer: Likewise. * include/experimental/chrono: Likewise. * include/experimental/deque: Likewise. * include/experimental/executor: Likewise. * include/experimental/filesystem: Likewise. * include/experimental/forward_list: Likewise. * include/experimental/functional: Likewise. * include/experimental/internet: Likewise. * include/experimental/io_context: Likewise. * include/experimental/iterator: Likewise. * include/experimental/list: Likewise. * include/experimental/map: Likewise. * include/experimental/memory: Likewise. * include/experimental/memory_resource: Likewise. * include/experimental/net: Likewise. * include/experimental/netfwd: Likewise. * include/experimental/numeric: Likewise. * include/experimental/optional: Likewise. * include/experimental/propagate_const: Likewise. * include/experimental/random: Likewise. * include/experimental/ratio: Likewise. * include/experimental/regex: Likewise. * include/experimental/scope: Likewise. * include/experimental/set: Likewise. * include/experimental/simd: Likewise. * include/experimental/socket: Likewise. * include/experimental/source_location: Likewise. * include/experimental/string: Likewise. * include/experimental/string_view: Likewise. * include/experimental/system_error: Likewise. * include/experimental/timer: Likewise. * include/experimental/tuple: Likewise. * include/experimental/unordered_map: Likewise. * include/experimental/unordered_set: Likewise. * include/experimental/utility: Likewise. * include/experimental/vector: Likewise. * include/std/barrier: Likewise. * include/std/chrono: Likewise. * include/std/condition_variable: Likewise. * include/std/deque: Likewise. * include/std/execution: Likewise. * include/std/filesystem: Likewise. * include/std/forward_list: Likewise. * include/std/fstream: Likewise. * include/std/future: Likewise. * include/std/iomanip: Likewise. * include/std/ios: Likewise. * include/std/iosfwd: Likewise. * include/std/iostream: Likewise. * include/std/istream: Likewise. * include/std/latch: Likewise. * include/std/list: Likewise. * include/std/locale: Likewise. * include/std/map: Likewise. * include/std/memory_resource: Likewise. * include/std/mutex: Likewise. * include/std/ostream: Likewise. * include/std/queue: Likewise. * include/std/random: Likewise. * include/std/regex: Likewise. * include/std/semaphore: Likewise. * include/std/set: Likewise. * include/std/shared_mutex: Likewise. * include/std/spanstream: Likewise. * include/std/sstream: Likewise. * include/std/stack: Likewise. * include/std/stacktrace: Likewise. * include/std/stop_token: Likewise. * include/std/streambuf: Likewise. * include/std/string: Likewise. * include/std/syncstream: Likewise. * include/std/system_error: Likewise. * include/std/thread: Likewise. * include/std/unordered_map: Likewise. * include/std/unordered_set: Likewise. * include/std/valarray: Likewise. * include/std/vector: Likewise. * include/tr1/array: Likewise. * include/tr1/ccomplex: Likewise. * include/tr1/cctype: Likewise. * include/tr1/cfenv: Likewise. * include/tr1/cfloat: Likewise. * include/tr1/cinttypes: Likewise. * include/tr1/climits: Likewise. * include/tr1/cmath: Likewise. * include/tr1/complex: Likewise. * include/tr1/complex.h: Likewise. * include/tr1/cstdarg: Likewise. * include/tr1/cstdbool: Likewise. * include/tr1/cstdint: Likewise. * include/tr1/cstdio: Likewise. * include/tr1/cstdlib: Likewise. * include/tr1/ctgmath: Likewise. * include/tr1/ctime: Likewise. * include/tr1/ctype.h: Likewise. * include/tr1/cwchar: Likewise. * include/tr1/cwctype: Likewise. * include/tr1/fenv.h: Likewise. * include/tr1/float.h: Likewise. * include/tr1/functional: Likewise. * include/tr1/inttypes.h: Likewise. * include/tr1/limits.h: Likewise. * include/tr1/math.h: Likewise. * include/tr1/memory: Likewise. * include/tr1/random: Likewise. * include/tr1/regex: Likewise. * include/tr1/stdarg.h: Likewise. * include/tr1/stdbool.h: Likewise. * include/tr1/stdint.h: Likewise. * include/tr1/stdio.h: Likewise. * include/tr1/stdlib.h: Likewise. * include/tr1/tgmath.h: Likewise. * include/tr1/tuple: Likewise. * include/tr1/type_traits: Likewise. * include/tr1/unordered_map: Likewise. * include/tr1/unordered_set: Likewise. * include/tr1/utility: Likewise. * include/tr1/wchar.h: Likewise. * include/tr1/wctype.h: Likewise. * include/c_global/cmath: Likewise. * include/ext/algorithm: Include <bits/requires_hosted.h>. * include/ext/bitmap_allocator.h: Likewise. * include/ext/cmath: Likewise. * include/ext/codecvt_specializations.h: Likewise. * include/ext/debug_allocator.h: Likewise. * include/ext/enc_filebuf.h: Likewise. * include/ext/extptr_allocator.h: Likewise. * include/ext/functional: Likewise. * include/ext/malloc_allocator.h: Likewise. * include/ext/memory: Likewise. * include/ext/mt_allocator.h: Likewise. * include/ext/new_allocator.h: Likewise. * include/ext/numeric: Likewise. * include/ext/pod_char_traits.h: Likewise. * include/ext/pool_allocator.h: Likewise. * include/ext/random: Likewise. * include/ext/random.tcc: Likewise. * include/ext/rb_tree: Likewise. * include/ext/rc_string_base.h: Likewise. * include/ext/rope: Likewise. * include/ext/ropeimpl.h: Likewise. * include/ext/slist: Likewise. * include/ext/sso_string_base.h: Likewise. * include/ext/stdio_filebuf.h: Likewise. * include/ext/stdio_sync_filebuf.h: Likewise. * include/ext/string_conversions.h: Likewise. * include/ext/throw_allocator.h: Likewise. * include/ext/vstring.h: Likewise. * include/ext/vstring.tcc: Likewise. * include/ext/vstring_fwd.h: Likewise. * include/ext/vstring_util.h: Likewise. * include/std/charconv: Likewise. (__cpp_lib_to_chars): Do not define for freestanding. * include/std/version: Adjust which macros get defined in freestanding. * include/ext/pointer.h [!_GLIBCXX_HOSTED]: Omit iostream functionality from freestanding. * include/std/algorithm [!_GLIBCXX_HOSTED]: Omit PSTL algos. * include/std/memory [!_GLIBCXX_HOSTED]: Omit <bits/stl_tempbuf.h> in freestanding * include/bits/algorithmfwd.h [!_GLIBCXX_HOSTED]: Omit leftover random_shuffle and stable_partition definition. * include/bits/stl_algo.h [!_GLIBCXX_HOSTED]: Omit random_shuffle and stable_partition from freestanding. * include/bits/ranges_algo.h [!_GLIBCXX_HOSTED]: Omit stable_partition from freestanding. * include/bits/concept_check.h: Remove needless HOSTED check. * include/std/iterator: Include <bits/ranges_base.h>. * include/std/numeric (__cpp_lib_parallel_algorithms): Do not define for freestanding. * include/std/functional (__cpp_lib_boyer_moore_searcher): Likewise. * testsuite/lib/prune.exp: Match error for hosted-only libstdc++ tests.
The new proposed resolution for LWG 3629 says that std::error_code and std::error_condition should only use ADL to find their customization points. This means we need to use a poison pill to prevent lookup from finding overloads in the enclosing namespaces. We can also remove the forward declarations of std::make_error_code and std::make_error_condition, because they aren't needed now. ADL can find them anyway (when std is an associated namespace), and unqualified name lookup will not (and should not) find them. libstdc++-v3/ChangeLog: * include/std/system_error (__adl_only::make_error_code): Add deleted function. (__adl_only::make_error_condition): Likewise. (error_code::error_code(ErrorCodeEnum)): Add using-declaration for deleted function. (error_condition::error_condition(ErrorConditionEnum)): Likewise. * testsuite/19_diagnostics/error_code/cons/lwg3629.cc: New test. * testsuite/19_diagnostics/error_condition/cons/lwg3629.cc: New test.
This removes the redundant operator=(E) from std::error_code and std::error_condition. Without that overload, assignment from a custom type will use the templated constructor to create a temporary and then use the trivial copy assignment operator. With the overloaded assignment, we have to check the constraints twice as often, because that overload and its constraints are checked for simple copy assignments (including the one in the overloaded assignment operator itself!) Also add tests that ADL is used as per LWG 3629. libstdc++-v3/ChangeLog: * include/std/system_error (error_code::_Check): New alias template for constructor SFINAE constraint. (error_code::error_code(ErrorCodeEnum)): Use it. (error_code::operator=(ErrorCodeEnum)): Remove. (error_condition::_Check): New alias template for constraint. (error_condition::error_condition(ErrorConditionEnum)): Use it. (error_condition::operator=(ErrorConditionEnum)): Remove. * testsuite/19_diagnostics/error_code/cons/1.cc: Check constructor taking user-defined error enum. * testsuite/19_diagnostics/error_condition/cons/1.cc: Likewise.
Add the const attribute to std::future_category() and std::iostream_category(), to match the existing attributes on std::generic_category() and std::system_category(). Also add [[nodiscard]] to those functions and to the comparison operators for std::error_code and std::error_condition, and to std::make_error_code and std::make_error_condition overloads. libstdc++-v3/ChangeLog: * include/bits/ios_base.h (io_category): Add const and nodiscard attributes. (make_error_code, make_error_condition): Add nodiscard. * include/std/future (future_category): Add const and nodiscard. (make_error_code, make_error_condition): Add nodiscard. * include/std/system_error (generic_category system_category): Add nodiscard. Replace _GLIBCXX_CONST with C++11 attribute. (error_code::value, error_code::category, error_code::operator bool) (error_condition::value, error_condition::category) (error_condition::operator bool, make_error_code) (make_error_condition, operator==, operator!=, operator<=>): Add nodiscard.
libstdc++-v3/ChangeLog: * include/std/system_error: Improve doxygen comments.