Commit graph

318 commits

Author SHA1 Message Date
Jonathan Wakely
1defe743ae
libstdc++: Export std::__basic_file::native_handle as GLIBCXX_3.4.33 [PR114692]
I added this new symbol in the wrong version. GLIBCXX_3.4.32 was
already used for the GCC 13.2.0 release, so the new symbol should have
been in a new GLIBCXX_3.4.33 version.

Additionally, the pattern doesn't need to use [cw] because we only ever
use __basic_file<char>, even for std::basic_filebuf<wchar_t>.

libstdc++-v3/ChangeLog:

	PR libstdc++/114692
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.32): Move new exports for
	__basic_file::native_handle to ...
	(GLIBCXX_3.4.33): ... here. Adjust to not match wchar_t
	specialization, which isn't used.
	* testsuite/util/testsuite_abi.cc: Add GLIBCXX_3.4.33 and update
	latest version check.
2024-04-11 15:22:33 +01:00
Jakub Jelinek
a945c346f5 Update copyright years. 2024-01-03 12:19:35 +01:00
François Dumont
6504b4a498 libstdc++: [_GLIBCXX_INLINE_VERSION] Add comment on emul TLS symbols
libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu-versioned-namespace.ver: Add comment on recently
	added emul TLS symbols.
2023-10-30 22:07:49 +01:00
François Dumont
3c444fb2ff libstdc++: [_GLIBCXX_INLINE_VERSION] Add emul TLS symbols
libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu-versioned-namespace.ver: Add missing emul TLS
	symbols.
2023-10-29 22:20:28 +01:00
François Dumont
7c0ae1a85b libstdc++: [_GLIBCXX_INLINE_VERSION] Add missing symbols
libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu-versioned-namespace.ver: Add missing symbols
	for _Float{16,32,64,128,32x,64x,128x}.
2023-10-05 21:58:57 +02:00
Jonathan Wakely
c4baeaecbb libstdc++: Implement C++26 native handles for file streams (P1759R6)
The new __basic_file::native_handle() function can be added for C++11
and above, because the names "native_handle" and "native_handle_type"
are already reserved since C++11. Exporting those symbols from the
shared library does no harm, even if the feature gets dropped before the
C++23 standard is final.

The new member functions of std::fstream etc. are only declared for
C++26 and so are not instantiated in src/c++11/fstream-inst.cc. Declare
them with the always_inline attribute so that no symbol definitions are
needed in the library (we can change this later when C++26 support is
less experimental).

libstdc++-v3/ChangeLog:

	* acinclude.m4 (GLIBCXX_CHECK_FILEBUF_NATIVE_HANDLES): New
	macro.
	* config.h.in: Regenerate.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.32): Export new
	basic_filebuf members.
	* config/io/basic_file_stdio.cc (__basic_file::native_handle):
	Define new function.
	* config/io/basic_file_stdio.h (__basic_file::native_handle):
	Declare new function.
	* configure: Regenerate.
	* configure.ac: Use GLIBCXX_CHECK_FILEBUF_NATIVE_HANDLES.
	* include/bits/version.def (fstream_native_handles): New macro.
	* include/bits/version.h: Regenerate.
	* include/std/fstream (basic_filebuf::native_handle)
	(basic_fstream::native_handle, basic_ifstream::native_handle)
	(basic_ofstream::native_handle): New functions.
	* src/c++11/Makefile.am: Move compilation of basic_file.cc,
	locale_init.cc and localename.cc to here.
	* src/c++11/Makefile.in: Regenerate.
	* src/c++98/locale_init.cc: Moved to...
	* src/c++11/locale_init.cc: ...here.
	* src/c++98/localename.cc: Moved to...
	* src/c++11/localename.cc: ...here.
	* src/c++98/Makefile.am: Remove basic_file.cc, locale_init.cc
	and localename.cc from here.
	* src/c++98/Makefile.in: Regenerate.
	* testsuite/27_io/basic_filebuf/native_handle/version.cc: New test.
	* testsuite/27_io/basic_fstream/native_handle/char/1.cc: New test.
	* testsuite/27_io/basic_fstream/native_handle/wchar_t/1.cc: New test.
	* testsuite/27_io/basic_ifstream/native_handle/char/1.cc: New test.
	* testsuite/27_io/basic_ifstream/native_handle/wchar_t/1.cc: New test.
	* testsuite/27_io/basic_ofstream/native_handle/char/1.cc: New test.
	* testsuite/27_io/basic_ofstream/native_handle/wchar_t/1.cc: New test.
2023-09-15 21:57:41 +01:00
François Dumont
3802297528 libstdc++: [_GLIBCXX_INLINE_VERSION] Add __cxa_call_terminate symbol export
libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu-versioned-namespace.ver: Add __cxa_call_terminate
	symbol export.
2023-08-06 14:29:07 +02:00
Jason Merrill
2415024e0f c++: use __cxa_call_terminate for MUST_NOT_THROW [PR97720]
[except.handle]/7 says that when we enter std::terminate due to a throw,
that is considered an active handler.  We already implemented that properly
for the case of not finding a handler (__cxa_throw calls __cxa_begin_catch
before std::terminate) and the case of finding a callsite with no landing
pad (the personality function calls __cxa_call_terminate which calls
__cxa_begin_catch), but for the case of a throw in a try/catch in a noexcept
function, we were emitting a cleanup that calls std::terminate directly
without ever calling __cxa_begin_catch to handle the exception.

A straightforward way to fix this seems to be calling __cxa_call_terminate
instead.  However, that requires exporting it from libstdc++, which we have
not previously done.  Despite the name, it isn't actually part of the ABI
standard.  Nor is __cxa_call_unexpected, as far as I can tell, but that one
is also used by clang.  For this case they use __clang_call_terminate; it
seems reasonable to me for us to stick with __cxa_call_terminate.

I also change __cxa_call_terminate to take void* for simplicity in the front
end (and consistency with __cxa_call_unexpected) but that isn't necessary if
it's undesirable for some reason.

This patch does not fix the issue that representing the noexcept as a
cleanup is wrong, and confuses the handler search; since it looks like a
cleanup in the EH tables, the unwinder keeps looking until it finds the
catch in main(), which it should never have gotten to.  Without the
try/catch in main, the unwinder would reach the end of the stack and say no
handler was found.  The noexcept is a handler, and should be treated as one,
as it is when the landing pad is omitted.

The best fix for that issue seems to me to be to represent an
ERT_MUST_NOT_THROW after an ERT_TRY in an action list as though it were an
ERT_ALLOWED_EXCEPTIONS (since indeed it is an exception-specification).  The
actual code generation shouldn't need to change (apart from the change made
by this patch), only the action table entry.

	PR c++/97720

gcc/cp/ChangeLog:

	* cp-tree.h (enum cp_tree_index): Add CPTI_CALL_TERMINATE_FN.
	(call_terminate_fn): New macro.
	* cp-gimplify.cc (gimplify_must_not_throw_expr): Use it.
	* except.cc (init_exception_processing): Set it.
	(cp_protect_cleanup_actions): Return it.

gcc/ChangeLog:

	* tree-eh.cc (lower_resx): Pass the exception pointer to the
	failure_decl.
	* except.h: Tweak comment.

libstdc++-v3/ChangeLog:

	* libsupc++/eh_call.cc (__cxa_call_terminate): Take void*.
	* config/abi/pre/gnu.ver: Add it.

gcc/testsuite/ChangeLog:

	* g++.dg/eh/terminate2.C: New test.
2023-06-03 21:49:00 -04:00
Jonathan Wakely
c62e945492 libstdc++: Enforce value_type consistency in strings and streams
P1463R1 made it ill-formed for allocator-aware containers (including
std::basic_string) to use an allocator that has a different value_type
from the container itself. We already enforce that for other containers
(since r8-4828-g866e4d3853ccc0), but not for std::basic_string. We
traditionally accepted it as an extension and rebound the allocator, so
this change only adds the enforcement for C++20 and later.

Similarly, P1148R0 made it ill-formed for strings and streams to use a
traits type that has an incorrect char_type. We already enforce that for
std::basic_string_view, so we just need to add it to std::basic_ios and
std::basic_string.

The assertion for the allocator's value_type caused some testsuite
regressions:
FAIL: 21_strings/basic_string/cons/char/deduction.cc (test for excess errors)
FAIL: 21_strings/basic_string/cons/wchar_t/deduction.cc (test for excess errors)
FAIL: 21_strings/basic_string/requirements/explicit_instantiation/debug.cc (test for excess errors)
FAIL: 21_strings/basic_string/requirements/explicit_instantiation/int.cc (test for excess errors)

The last two are testing the traditional extension that rebinds the
allocator, so need to be disabled for C++20.

The first two are similar to LWG 3076 where an incorrect constructor is
considered for CTAD. In this case, determining that it's not viable
requires instantiating std::basic_string<Iter, char_traits<Iter>, Alloc>
which then fails the new assertion, because Alloc::value_type is not the
same as Iter. This is only a problem because the size_type parameter of
the non-viable constructor is an alias for
_Alloc_traits_impl<A>::size_type which is a nested type, and so the
enclosing basic_string specialization needs to be instantiated. If we
remove the _Alloc_traits_impl wrapper that was added in
r12-5413-g2d76292bd6719d, then the definition of size_type no longer
depends on basic_string, and we don't instantiate an invalid
specialization and don't fail the assertion. The work done by
_Alloc_traits_impl::allocate can be done in a _S_allocate function
instead, which is probably more efficient to compile anyway.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver: Export basic_string::_S_allocate.
	* include/bits/basic_ios.h: Add static assertion checking
	traits_type::value_type.
	* include/bits/basic_string.h: Likewise. Do not rebind
	allocator, and add static assertion checking its value_type.
	(basic_string::_Alloc_traits_impl): Remove class template.
	(basic_string::_S_allocate): New static member function.
	(basic_string::assign): Use _S_allocate.
	* include/bits/basic_string.tcc (basic_string::_M_create)
	(basic_string::reserve, basic_string::_M_replace): Likewise.
	* testsuite/21_strings/basic_string/requirements/explicit_instantiation/debug.cc:
	Disable for C++20 and later.
	* testsuite/21_strings/basic_string/requirements/explicit_instantiation/int.cc:
	Likweise.
2023-05-11 21:15:22 +01:00
Jakub Jelinek
9a41d2cdbc libstdc++: Another attempt to ensure g++ 13+ compiled programs enforce gcc 13.2+ libstdc++.so.6 [PR108969]
GCC used to emit an instance of an empty ios_base::Init class in
every TU which included <iostream> to ensure it is std::cout etc.
is initialized, but thanks to Patrick work on some targets (which have
init_priority attribute support) it is now initialized only inside of
libstdc++.so.6/libstdc++.a.

This causes a problem if people do something that has never been supported,
try to run GCC 13 compiled C++ code against GCC 12 or earlier
libstdc++.so.6 - std::cout etc. are then never initialized because code
including <iostream> expects the library to initialize it and the library
expects code including <iostream> to do that.

The following patch is second attempt to make this work cheaply as the
earlier attempt of aliasing the std::cout etc. symbols with another symbol
version didn't work out due to copy relocation breaking the aliases appart.

The patch forces just a _ZSt21ios_base_library_initv undefined symbol
into all *.o files which include <iostream> and while there is no runtime
relocation against that, it seems to enforce the right version of
libstdc++.so.6.  /home/jakub/src/gcc/obj08i/usr/local/ is the install
directory of trunk patched with this patch, /home/jakub/src/gcc/obj06/
is builddir of trunk without this patch, system g++ is GCC 12.1.1.
$ cat /tmp/hw.C
 #include <iostream>

int
main ()
{
  std::cout << "Hello, world!" << std::endl;
}
$ cd /home/jakub/src/gcc/obj08i/usr/local/bin
$ ./g++ -o /tmp/hw /tmp/hw.C
$ readelf -Wa /tmp/hw 2>/dev/null | grep initv
     4: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND _ZSt21ios_base_library_initv@GLIBCXX_3.4.32 (4)
    71: 0000000000000000     0 FUNC    GLOBAL DEFAULT  UND _ZSt21ios_base_library_initv@GLIBCXX_3.4.32
$ /tmp/hw
/tmp/hw: /lib64/libstdc++.so.6: version `GLIBCXX_3.4.32' not found (required by /tmp/hw)
$ LD_LIBRARY_PATH=/home/jakub/src/gcc/obj08i/usr/local/lib64/ /tmp/hw
Hello, world!
$ LD_LIBRARY_PATH=/home/jakub/src/gcc/obj06/x86_64-pc-linux-gnu/libstdc++-v3/src/.libs/ /tmp/hw
/tmp/hw: /home/jakub/src/gcc/obj06/x86_64-pc-linux-gnu/libstdc++-v3/src/.libs/libstdc++.so.6: version `GLIBCXX_3.4.32' not found (required by /tmp/hw)
$ g++ -o /tmp/hw /tmp/hw.C
$ /tmp/hw
Hello, world!
$ LD_LIBRARY_PATH=/home/jakub/src/gcc/obj06/x86_64-pc-linux-gnu/libstdc++-v3/src/.libs/ /tmp/hw
Hello, world!
$ LD_LIBRARY_PATH=/home/jakub/src/gcc/obj08i/usr/local/lib64/ /tmp/hw
Hello, world!

On sparc-sun-solaris2.11 one I've actually checked a version which had
defined(_GLIBCXX_SYMVER_SUN) next to defined(_GLIBCXX_SYMVER_GNU), but
init_priority attribute doesn't seem to be supported there and so I couldn't
actually test how this works there.  Using gas and Sun ld, Rainer, does one
need to use gas + gld for init_priority or something else?

2023-04-28  Jakub Jelinek  <jakub@redhat.com>

	PR libstdc++/108969
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.32): Export
	_ZSt21ios_base_library_initv.
	* testsuite/util/testsuite_abi.cc (check_version): Add GLIBCXX_3.4.32
	symver and make it the latestp.
	* src/c++98/ios_init.cc (ios_base_library_init): New alias.
	* acinclude.m4 (libtool_VERSION): Change to 6:32:0.
	* include/std/iostream: If init_priority attribute is supported
	and _GLIBCXX_SYMVER_GNU, force undefined _ZSt21ios_base_library_initv
	symbol into the object.
	* configure: Regenerated.
2023-04-28 10:49:40 +02:00
Jonathan Wakely
fac24d43e6 Revert "libstdc++: Export global iostreams with GLIBCXX_3.4.31 symver [PR108969]"
This reverts commit b7c54e3f48.

libstdc++-v3/ChangeLog:

	* config/abi/post/aarch64-linux-gnu/baseline_symbols.txt:
	* config/abi/post/i486-linux-gnu/baseline_symbols.txt:
	* config/abi/post/m68k-linux-gnu/baseline_symbols.txt:
	* config/abi/post/powerpc64-linux-gnu/baseline_symbols.txt:
	* config/abi/post/riscv64-linux-gnu/baseline_symbols.txt:
	* config/abi/post/s390x-linux-gnu/baseline_symbols.txt:
	* config/abi/post/x86_64-linux-gnu/32/baseline_symbols.txt:
	* config/abi/post/x86_64-linux-gnu/baseline_symbols.txt:
	* config/abi/pre/gnu.ver:
	* src/Makefile.am:
	* src/Makefile.in:
	* src/c++98/Makefile.am:
	* src/c++98/Makefile.in:
	* src/c++98/globals_io.cc (defined):
	(_GLIBCXX_IO_GLOBAL):
2023-04-19 13:18:12 +01:00
Jonathan Wakely
a6e4b81b12 Revert "libstdc++: Fix preprocessor condition in linker script [PR108969]"
This reverts commit 6067ae4557.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver:
2023-04-19 13:18:12 +01:00
Jonathan Wakely
6067ae4557 libstdc++: Fix preprocessor condition in linker script [PR108969]
The linker script is preprocessed with $(top_builddir)/config.h not the
include/$target/bits/c++config.h version, which means that configure
macros do not have the _GLIBCXX_ prefix yet.

The _GLIBCXX_SYMVER_GNU and _GLIBCXX_SHARED checks are redundant,
because the gnu.ver file is only used for _GLIBCXX_SYMVER_GNU and the
linker script is only used for the shared library. Remove those.

libstdc++-v3/ChangeLog:

	PR libstdc++/108969
	* config/abi/pre/gnu.ver: Fix preprocessor condition.
2023-04-18 17:28:29 +01:00
Jonathan Wakely
b7c54e3f48 libstdc++: Export global iostreams with GLIBCXX_3.4.31 symver [PR108969]
Since GCC 13 the global iostream objects are only initialized once in
libstdc++, and not by a std::ios::Init object in every translation unit
that includes <iostream>. To avoid using uninitialized streams defined
in an older libstdc++.so, translation units using the global iostreams
should depend on the GLIBCXX_3.4.31 symver.

Define std::cin as std::__io::cin and then export it as
std::cin@@GLIBCXX_3.4.31 so that references to std::cin bind to the new
symver. Also export it as @GLIBCXX_3.4 for backwards compatibility

libstdc++-v3/ChangeLog:

	PR libstdc++/108969
	* src/Makefile.am: Move globals_io.cc to here.
	* src/Makefile.in: Regenerate.
	* src/c++98/Makefile.am: Remove globals_io.cc from here.
	* src/c++98/Makefile.in: Regenerate.
	* src/c++98/globals_io.cc [_GLIBCXX_SYMVER_GNU] (cin): Adjust
	symbol name and then export with GLIBCXX_3.4.31 symver.
	(cout, cerr, clog, wcin, wcout, wcerr, wclog): Likewise.
	* config/abi/post/aarch64-linux-gnu/baseline_symbols.txt:
	Regenerate.
	* config/abi/post/i486-linux-gnu/baseline_symbols.txt:
	Regenerate.
	* config/abi/post/m68k-linux-gnu/baseline_symbols.txt:
	Regenerate.
	* config/abi/post/powerpc64-linux-gnu/baseline_symbols.txt:
	Regenerate.
	* config/abi/post/riscv64-linux-gnu/baseline_symbols.txt:
	Regenerate.
	* config/abi/post/x86_64-linux-gnu/32/baseline_symbols.txt:
	Regenerate.
	* config/abi/post/s390x-linux-gnu/baseline_symbols.txt:
	Regenerate.
	* config/abi/post/x86_64-linux-gnu/baseline_symbols.txt:
	Regenerate.
	* config/abi/pre/gnu.ver: Add iostream objects to new symver.
2023-04-18 16:42:25 +01:00
Jakub Jelinek
13071c3c7d aarch64: Add bfloat16_t support for aarch64
x86_64/i686 has for a few months working std::bfloat16_t support, __bf16
there is no longer a storage only type, but can be used for arithmetics
and is supported in libgcc and libstdc++.

The following patch adds similar support for AArch64.

Unlike the x86 changes, this one keeps the old __bf16 mangling of
u6__bf16 rather than DF16b (so an exception from Itanium ABI), but
otherwise __bf16 and decltype (0.0bf16) are the same type and both
in C++ act as extended floating-point type.

2023-03-13  Jakub Jelinek  <jakub@redhat.com>

gcc/
	* config/aarch64/aarch64.h (aarch64_bf16_type_node): Remove.
	(aarch64_bf16_ptr_type_node): Adjust comment.
	* config/aarch64/aarch64.cc (aarch64_gimplify_va_arg_expr): Use
	bfloat16_type_node rather than aarch64_bf16_type_node.
	(aarch64_libgcc_floating_mode_supported_p,
	aarch64_scalar_mode_supported_p): Also support BFmode.
	(aarch64_invalid_conversion, aarch64_invalid_unary_op): Remove.
	(aarch64_invalid_binary_op): Remove BFmode related rejections.
	(TARGET_INVALID_CONVERSION, TARGET_INVALID_UNARY_OP): Don't redefine.
	* config/aarch64/aarch64-builtins.cc (aarch64_bf16_type_node): Remove.
	(aarch64_int_or_fp_type): Use bfloat16_type_node rather than
	aarch64_bf16_type_node.
	(aarch64_init_simd_builtin_types): Likewise.
	(aarch64_init_bf16_types): Likewise.  Don't create bfloat16_type_node,
	which is created in tree.cc already.
	* config/aarch64/aarch64-sve-builtins.def (svbfloat16_t): Likewise.
gcc/testsuite/
	* gcc.target/aarch64/sve/acle/general-c/ternary_bfloat16_opt_n_1.c:
	Don't expect one __bf16 related error.
	* gcc.target/aarch64/bfloat16_vector_typecheck_1.c: Adjust or remove
	dg-error directives for __bf16 being an extended arithmetic type.
	* gcc.target/aarch64/bfloat16_vector_typecheck_2.c: Likewise.
	* gcc.target/aarch64/bfloat16_scalar_typecheck.c: Likewise.
	* g++.target/aarch64/bfloat_cpp_typecheck.C: Don't expect two __bf16
	related errors.
libgcc/
	* config/aarch64/t-softfp (softfp_extensions): Add bfsf.
	(softfp_truncations): Add tfbf dfbf sfbf hfbf.
	(softfp_extras): Add floatdibf floatundibf floattibf floatuntibf.
	* config/aarch64/libgcc-softfp.ver (GCC_13.0.0): Export
	__extendbfsf2 and __trunc{s,d,t,h}fbf2.
	* config/aarch64/sfp-machine.h (_FP_NANFRAC_B, _FP_NANSIGN_B): Define.
	* soft-fp/floatundibf.c: New file.
	* soft-fp/floatdibf.c: New file.
libstdc++-v3/
	* config/abi/pre/gnu.ver (CXXABI_1.3.14): Also export __bf16 tinfos
	if it isn't mangled as DF16b but u6__bf16.
2023-03-13 00:16:45 +01:00
Jonathan Wakely
7d30593c38 libstdc++: Fix symver for __gnu_cxx11_ieee128::__try_use_facet [PR108882]
libstdc++-v3/ChangeLog:

	PR libstdc++/108882
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.31): Adjust patterns to
	not match symbols in namespace std::__gnu_cxx11_ieee128.
	* config/os/gnu-linux/ldbl-ieee128-extra.ver: Add patterns for
	std::__gnu_cxx11_ieee128::money_{get,put}.
2023-03-07 17:33:28 +00:00
Jonathan Wakely
db8d6fc572 libstdc++: Fix std::filesystem errors with -fkeep-inline-functions [PR108636]
With -fkeep-inline-functions there are linker errors when including
<filesystem>. This happens because there are some filesystem::path
constructors defined inline which call non-exported functions defined in
the library. That's usually not a problem, because those constructors
are only called by code that's also inside the library. But when the
header is compiled with -fkeep-inline-functions those inline functions
are emitted even though they aren't called. That then creates an
undefined reference to the other library internsl. The fix is to just
move the private constructors into the library where they are called.
That way they are never even seen by users, and so not compiled even if
-fkeep-inline-functions is used.

On trunk there is a second problem, which is that the new equality
operators for comparing directory iterators with default_sentinel use
the shared_ptr::operator bool() conversion operator. The shared_ptr
specializations used by directory iterators are explicitly instantiated
in the library, but the bool conversion operators are not exported. This
causes linker errors at -O0 or with -fkeep-inline-functions. That just
requires the conversion operators to be exported.

libstdc++-v3/ChangeLog:

	PR libstdc++/108636
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.31): Export shared_ptr
	conversion operators for directory iterator comparisons with
	std::default_sentinel_t.
	* include/bits/fs_path.h (path::path(string_view, _Type))
	(path::_Cmpt::_Cmpt(string_view, _Type, size_t)): Move inline
	definitions to ...
	* src/c++17/fs_path.cc: ... here.
	* testsuite/27_io/filesystem/path/108636.cc: New test.
2023-02-02 16:18:37 +00:00
Jakub Jelinek
83ffe9cde7 Update copyright years. 2023-01-16 11:52:17 +01:00
François Dumont
e176c031f0 libstdc++: [_GLIBCXX_INLINE_VERSION] Add to_chars/from_chars symbols export
libstdc++-v3/ChangeLog

	* include/std/format [_GLIBCXX_INLINE_VERSION](to_chars): Adapt __asm symbol
	specifications.
	* config/abi/pre/gnu-versioned-namespace.ver: Add to_chars/from_chars symbols
	export.
2023-01-14 14:24:35 +01:00
Jonathan Wakely
b1ad748754 libstdc++: Only use std::atomic<tzdb_list::_Node*> if lock free [PR108228]
This fixes linker errors for hppa-hp-hpux11.11 due to an undefined weak
symbol and the use of atomic operations that require libatomic.

The weak symbol can simply be defined, which we already do for darwin.

The std::atomic<_Node*> is only an optimization, so can be avoided for
targets where the underlying atomic ops aren't available without help
from libatomic. The accesses to the std::atomic<_Node*> can be
abstracted behind a new API for getting and setting the cached value,
and then the atomics can be used conditionally.

libstdc++-v3/ChangeLog:

	PR libstdc++/108228
	PR libstdc++/108235
	* config/abi/pre/gnu.ver: Move zoneinfo_dir_override export to
	the latest symbol version.
	* src/c++20/tzdb.cc (USE_ATOMIC_SHARED_PTR): Define to 0 if
	atomic<_Node*> is not always lock free.
	(USE_ATOMIC_LIST_HEAD): New macro.
	[__hpux__] (__gnu_cxx::zoneinfo_dir_override()): Provide
	definition of weak symbol.
	(tzdb_list::_Node::_S_head): Rename to _S_head_cache.
	(tzdb_list::_Node::_S_list_head): New function for accessing
	list head efficiently.
	(tzdb_list::_Node::_S_cache_list_head): New function for
	updating _S_list_head.
2023-01-05 00:46:00 +00:00
Iain Sandoe
96cba8ebe5 libstdc++: Export the __gnu_cxx::zoneinfo_dir_override symbol [PR108228].
This symbol needs to be visible in the library interface for Darwin
to override it with a user-provided one.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>

	PR libstdc++/108228

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver (GLIBCXX_3.4):
	Add __gnu_cxx::zoneinfo_dir_override().
2023-01-04 15:33:16 +00:00
Jonathan Wakely
9fc61d45fa libstdc++: Implement C++20 time zone support in <chrono>
This is the largest missing piece of C++20 support. Only the cxx11 ABI
is supported, due to the use of std::string in the API for time zones.
For the old gcc4 ABI, utc_clock and leap seconds are supported, but only
using a hardcoded list of leap seconds, no up-to-date tzdb::leap_seconds
information is available, and no time zones or zoned_time conversions.

The implementation currently depends on a tzdata.zi file being provided
by the OS or the user. The expected location is /usr/share/zoneinfo but
that can be changed using --with-libstdcxx-zoneinfo-dir=PATH. On targets
that support it there is also a weak symbol that users can override in
their own program (which also helps with testing):

extern "C++" const char* __gnu_cxx::zoneinfo_dir_override();

If no file is found, a fallback tzdb object will be created which only
contains the "Etc/UTC" and "Etc/GMT" time zones.

A leapseconds file is also expected in the same directory, but if that
isn't present then a hardcoded list of leapseconds is used, which is
correct at least as far as 2023-06-28 (and it currently looks like no
leap second will be inserted for a few years).

The tzdata.zi and leapseconds files from https://www.iana.org/time-zones
are in the public domain, so shipping copies of them with GCC would be
an option. However, the tzdata.zi file will rapidly become outdated, so
users should really provide it themselves (or convince their OS vendor
to do so). It would also be possible to implement an alternative parser
for the compiled tzdata files (one per time zone) under
/usr/share/zoneinfo. Those files are present on more operating systems,
but do not contain all the information present in tzdata.zi.
Specifically, the "links" are not present, so that e.g. "UTC" and
"Universal" are distinct time zones, rather than both being links to the
canonical "Etc/UTC" zone. For some platforms those files are hard links
to the same file, but there's no indication which zone is the canonical
name and which is a link. Other platforms just store them in different
inodes anyway. I do not plan to add such an alternative parser for the
compiled files. That would need to be contributed by maintainers or
users of targets that require it, if making tzdata.zi available is not
an option. The library ABI would not need to change for a new tzdb
implementation, because everything in tzdb_list, tzdb and time_zone is
implemented as a pimpl (except for the shared_ptr links between nodes,
described below). That means the new exported symbols added by this
commit should be stable even if the implementation is completely
rewritten.

The information from tzdata.zi is parsed and stored in data structures
that closely model the info in the file. This is a space-efficient
representation that uses less memory that storing every transition for
every time zone.  It also avoids spending time expanding that
information into time zone transitions that might never be needed by the
program.  When a conversion to/from a local time to UTC is requested the
information will be processed to determine the time zone transitions
close to the time being converted.

There is a bug in some time zone transitions. When generating a sys_info
object immediately after one that was previously generated, we need to
find the previous rule that was in effect and note its offset and
letters. This is so that the start time and abbreviation of the new
sys_info will be correct. This only affects time zones that use a format
like "C%sT" where the LETTERS replacing %s are non-empty for standard
time, e.g. "Asia/Shanghai" which uses "CST" for standard time and "CDT"
for daylight time.

The tzdb_list structure maintains a linked list of tzdb nodes using
shared_ptr links. This allows the iterators into the list to share
ownership with the list itself. This offers a non-portable solution to a
lifetime issue in the API. Because tzdb objects can be erased from the
list using tzdb_list::erase_after, separate modules/libraries in a large
program cannot guarantee that any const tzdb& or const time_zone*
remains valid indefinitely. Holding onto a tzdb_list::const_iterator
will extend the tzdb object's lifetime, even if it's erased from the
list. An alternative design would be for the list iterator to hold a
weak_ptr. This would allow users to test whether the tzdb still exists
when the iterator is dereferenced, which is better than just having a
dangling raw pointer. That doesn't actually extend the tzdb's lifetime
though, and every use of it would need to be preceded by checking the
weak_ptr. Using shared_ptr adds a little bit of overhead but allows
users to solve the lifetime issue if they rely on the libstdc++-specific
iterator property.

libstdc++-v3/ChangeLog:

	* acinclude.m4 (GLIBCXX_ZONEINFO_DIR): New macro.
	* config.h.in: Regenerate.
	* config/abi/pre/gnu.ver: Export new symbols.
	* configure: Regenerate.
	* configure.ac (GLIBCXX_ZONEINFO_DIR): Use new macro.
	* include/std/chrono (utc_clock::from_sys): Correct handling
	of leap seconds.
	(nonexistent_local_time::_M_make_what_str): Define.
	(ambiguous_local_time::_M_make_what_str): Define.
	(__throw_bad_local_time): Define new function.
	(time_zone, tzdb_list, tzdb): Implement all members.
	(remote_version, zoned_time, get_leap_second_info): Define.
	* include/std/version: Add comment for __cpp_lib_chrono.
	* src/c++20/Makefile.am: Add new file.
	* src/c++20/Makefile.in: Regenerate.
	* src/c++20/tzdb.cc: New file.
	* testsuite/lib/libstdc++.exp: Define effective target tzdb.
	* testsuite/std/time/clock/file/members.cc: Check file_time
	alias and file_clock::now() member.
	* testsuite/std/time/clock/gps/1.cc: Likewise for gps_clock.
	* testsuite/std/time/clock/tai/1.cc: Likewise for tai_clock.
	* testsuite/std/time/syn_c++20.cc: Uncomment everything except
	parse.
	* testsuite/std/time/clock/utc/leap_second_info.cc: New test.
	* testsuite/std/time/exceptions.cc: New test.
	* testsuite/std/time/time_zone/get_info_local.cc: New test.
	* testsuite/std/time/time_zone/get_info_sys.cc: New test.
	* testsuite/std/time/time_zone/requirements.cc: New test.
	* testsuite/std/time/tzdb/1.cc: New test.
	* testsuite/std/time/tzdb/leap_seconds.cc: New test.
	* testsuite/std/time/tzdb_list/1.cc: New test.
	* testsuite/std/time/tzdb_list/requirements.cc: New test.
	* testsuite/std/time/zoned_time/1.cc: New test.
	* testsuite/std/time/zoned_time/custom.cc: New test.
	* testsuite/std/time/zoned_time/deduction.cc: New test.
	* testsuite/std/time/zoned_time/req_neg.cc: New test.
	* testsuite/std/time/zoned_time/requirements.cc: New test.
	* testsuite/std/time/zoned_traits.cc: New test.
2022-12-22 23:34:20 +00:00
Jakub Jelinek
3f101e32e2 c++, libstdc++: Add typeinfo for _Float{16,32,64,128,32x,64x} and __bf16 types [PR108075]
The following patch adds typeinfos for the extended floating point
types and _Float{32,64}x.

2022-12-15  Jakub Jelinek  <jakub@redhat.com>

	PR libstdc++/108075
gcc/cp/
	* rtti.cc (emit_support_tinfos): Add pointers to
	{bfloat16,float{16,32,64,128,32x,64x,128x}}_type_node to fundamentals
	array.
gcc/testsuite/
	* g++.dg/cpp23/ext-floating13.C: New test.
libstdc++-v3/
	* config/abi/pre/gnu.ver (CXXABI_1.3.14): Export
	_ZTIDF[0-9]*[_bx], _ZTIPDF[0-9]*[_bx] and _ZTIPKDF[0-9]*[_bx].
	* testsuite/util/testsuite_abi.cc (check_version): Handle
	CXXABI_1.3.14.
2022-12-15 17:02:55 +01:00
Jonathan Wakely
b3ac43a3c0 libstdc++: Avoid redundant checks in std::use_facet [PR103755]
We do not need to do bounds checks or a runtime dynamic_cast when using
std::has_facet and std::use_facet to access the default facets that are
guaranteed to be present in every std::locale object. We can just index
straight into the array and use a static_cast for the conversion.

This patch adds a new std::__try_use_facet function that is like
std::use_facet but returns a pointer, so can be used to implement both
std::has_facet and std::use_facet. We can then do the necessary
metaprogramming to skip the redundant checks in std::__try_use_facet.

To avoid having to export (or hide) instantiations of the new function
from libstdc++.so the instantiations are given hidden visibility. This
allows them to be used in the library, but user code will instantiate it
again using the definition in the header. That would happen anyway,
because there are no explicit instantiation declarations for any of
std::has_facet, std::use_facet, or the new std::__try_use_facet.

libstdc++-v3/ChangeLog:

	PR libstdc++/103755
	* config/abi/pre/gnu.ver: Tighten patterns for facets in the
	base version. Add exports for __try_use_facet.
	* include/bits/basic_ios.tcc (basic_ios::_M_cache_locale): Use
	__try_use_facet instead of has_facet and use_facet.
	* include/bits/fstream.tcc (basic_filebuf::basic_filebuf()):
	Likewise.
	(basic_filebuf::imbue): Likewise.
	* include/bits/locale_classes.h (locale, locale::id)
	(locale::_Impl): Declare __try_use_facet as a friend.
	* include/bits/locale_classes.tcc (__try_use_facet): Define new
	function template with special cases for default facets.
	(has_facet, use_facet): Call __try_use_facet.
	* include/bits/locale_facets.tcc (__try_use_facet): Declare
	explicit instantiations.
	* include/bits/locale_facets_nonio.tcc (__try_use_facet):
	Likewise.
	* src/c++11/locale-inst-monetary.h (INSTANTIATE_FACET_ACCESSORS):
	Use new macro for facet accessor instantiations.
	* src/c++11/locale-inst-numeric.h (INSTANTIATE_FACET_ACCESSORS):
	Likewise.
	* src/c++11/locale-inst.cc (INSTANTIATE_USE_FACET): Define new
	macro for instantiating __try_use_facet and use_facet.
	(INSTANTIATE_FACET_ACCESSORS): Define new macro for also
	defining has_facet.
	* src/c++98/compatibility-ldbl.cc (__try_use_facet):
	Instantiate.
	* testsuite/22_locale/ctype/is/string/89728_neg.cc: Adjust
	expected errors.
2022-11-11 04:00:58 +00:00
Jakub Jelinek
e5bcbcd04c libstdc++: Add _Float128 to_chars/from_chars support for x86, ia64 and ppc64le with glibc
The following patch adds std::{to,from}_chars support for std::float128_t
on glibc 2.26+ for {i?86,x86_64,ia64,powerpc64le}-linux.
When long double is already IEEE quad, previous changes already handle
it by using long double overloads in _Float128 overloads.
The powerpc64le case (with explicit or implicit -mabi=ibmlongdouble)
is handled by using the __float128/__ieee128 entrypoints which are
already in the library and used for -mabi=ieeelongdouble.
For i?86, x86_64 and ia64 this patch adds new library entrypoints,
mostly by enabling the code that was already there for powerpc64le-linux.
Those use __float128 or __ieee128, the patch uses _Float128 for the
exported overloads and internally as template parameter.  While
powerpc64le-linux uses __sprintfieee128 and __strtoieee128,
for _Float128 the patch uses the glibc 2.26 strfromf128 and strtof128
APIs.  So that one can build gcc against older glibc and then compile
user programs on newer glibc, the patch uses weak references unless
gcc is compiled against glibc 2.26+.  strfromf128 unfortunately can't
handle %.0Lf and %.*Le, %.*Lf, %.*Lg format strings sprintf/__sprintfieee128
use, we need to remove the L from those and replace * with actually
directly printing the precision into the format string (i.e. it can
handle %.0f and %.27f (floating point type is implied from the function
name)).
Unlike the std::{,b}float16_t support, this one actually exports APIs
with std::float128_t aka _Float128 in the mangled name, because no
standard format is superset of it.  On the other side, e.g. on i?86/x86_64
it doesn't have restrictions like for _Float16/__bf16 which ISAs need
to be enabled in order to use it.

The denorm_min case in the testcase is temporarily commented out because
of the ERANGE subnormal issue Patrick posted patch for.

2022-11-07  Jakub Jelinek  <jakub@redhat.com>

	* include/std/charconv (from_chars, to_chars): Add _Float128
	overfloads if _GLIBCXX_HAVE_FLOAT128_MATH is defined.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.31): Export
	_ZSt8to_charsPcS_DF128_, _ZSt8to_charsPcS_DF128_St12chars_format,
	_ZSt8to_charsPcS_DF128_St12chars_formati and
	_ZSt10from_charsPKcS0_RDF128_St12chars_format.
	* src/c++17/floating_from_chars.cc (USE_STRTOF128_FOR_FROM_CHARS):
	Define if needed.
	(__strtof128): Declare.
	(from_chars_impl): Handle _Float128.
	(from_chars): New _Float128 overload if USE_STRTOF128_FOR_FROM_CHARS
	is define.
	* src/c++17/floating_to_chars.cc (__strfromf128): Declare.
	(FLOAT128_TO_CHARS): Define even when _Float128 is supported and
	wider than long double.
	(F128_type): Use _Float128 for that case.
	(floating_type_traits): Specialize for F128_type rather than
	__float128.
	(sprintf_ld): Add length argument.  Handle _Float128.
	(__floating_to_chars_shortest, __floating_to_chars_precision):
	Pass length to sprintf_ld.
	(to_chars): Add _Float128 overloads for the F128_type being
	_Float128 cases.
	* testsuite/20_util/to_chars/float128_c++23.cc: New test.
2022-11-07 15:15:50 +01:00
Jakub Jelinek
81f98afa22 libstdc++: std::from_chars std::{,b}float16_t support
The following patch adds std::from_chars support, similarly to the
previous std::to_chars patch through APIs that use float instead of
the 16-bit floating point formats as container.
The patch uses the fast_float library and doesn't need any changes
to it, like the previous patch it introduces wrapper classes around
float that represent the float holding float16_t or bfloat16_t value,
and specializes binary_format etc. from fast_float for these classes.

The new test verifies exhaustively to_chars and from_chars afterward
results in the original value (except for nans) in all the fmt cases.

2022-11-01  Jakub Jelinek  <jakub@redhat.com>

	* include/std/charconv (__from_chars_float16_t,
	__from_chars_bfloat16_t): Declare.
	(from_chars): Add _Float16 and __gnu_cxx::__bfloat16_t overloads.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.31): Export
	_ZSt22__from_chars_float16_tPKcS0_RfSt12chars_format and
	_ZSt23__from_chars_bfloat16_tPKcS0_RfSt12chars_format.
	* src/c++17/floating_from_chars.cc
	(fast_float::floating_type_float16_t,
	fast_float::floating_type_bfloat16_t): New classes.
	(fast_float::binary_format<floating_type_float16_t>,
	fast_float::binary_format<floating_type_bfloat16_t>): New
	specializations.
	(fast_float::to_float<floating_type_float16_t>,
	fast_float::to_float<floating_type_bfloat16_t>,
	fast_float::to_extended<floating_type_float16_t>,
	fast_float::to_extended<floating_type_bfloat16_t>): Likewise.
	(fast_float::from_chars_16): New template function.
	(__floating_from_chars_hex): Allow instantiation with
	fast_float::floating_type_{,b}float16_t.
	(from_chars): Formatting fixes for float/double/long double overloads.
	(__from_chars_float16_t, __from_chars_bfloat16_t): New functions.
	* testsuite/20_util/to_chars/float16_c++23.cc: New test.
2022-11-01 13:41:57 +01:00
Jakub Jelinek
0ae26533b3 libstdc++: std::to_chars std::{,b}float16_t support
The following patch on top of
https://gcc.gnu.org/pipermail/libstdc++/2022-October/054849.html
adds std::{,b}float16_t support for std::to_chars.
When precision is specified (or for std::bfloat16_t for hex mode even if not),
I believe we can just use the std::to_chars float (when float is mode
compatible with std::float32_t) overloads, both formats are proper subsets
of std::float32_t.
Unfortunately when precision is not specified and we are supposed to emit
shortest string, the std::{,b}float16_t strings are usually much shorter.
E.g. 1.e7p-14f16 shortest fixed representation is
0.0001161 and shortest scientific representation is
1.161e-04 while 1.e7p-14f32 (same number promoted to std::float32_t)
0.00011610985 and
1.1610985e-04.
Similarly for 1.38p-112bf16,
0.000000000000000000000000000000000235
2.35e-34 vs. 1.38p-112f32
0.00000000000000000000000000000000023472271
2.3472271e-34
For std::float16_t there are differences even in the shortest hex, say:
0.01p-14 vs. 1p-22
but only for denormal std::float16_t values (where all std::float16_t
denormals converted to std::float32_t are normal), __FLT16_MIN__ and
everything larger in absolute value than that is the same.  Unless
that is a bug and we should try to discover shorter representations
even for denormals...
std::bfloat16_t has the same exponent range as std::float32_t, so all
std::bfloat16_t denormals are also std::float32_t denormals and thus
the shortest hex representations are the same.
As documented, ryu can handle arbitrary IEEE like floating point formats
(probably not wider than IEEE quad) using the generic_128 handling, but
ryu is hidden in libstdc++.so.  As only few architectures support
std::float16_t right now and some of them have special ISA requirements
for those (e.g. on i?86 one needs -msse2) and std::bfloat16_t is right
now supported only on x86 (again with -msse2), perhaps with aarch64/arm
coming next if ARM is interested, but I think it is possible that more
will be added later, instead of exporting APIs from the library to handle
directly the std::{,b}float16_t overloads this patch instead exports
functions which take a float which is a superset of those and expects
the inline overloads to promote the 16-bit formats to 32-bit, then inside
of the library it ensures they are printed right.
With the added [[gnu::cold]] attribute because I think most users
will primarily use these formats as storage formats and perform arithmetics
in the excess precision for them and print also as std::float32_t the
added support doesn't seem to be too large, on x86_64:
readelf -Ws libstdc++.so.6.0.31 | grep float16_t
   912: 00000000000ae824   950 FUNC    GLOBAL DEFAULT   13 _ZSt21__to_chars_bfloat16_tPcS_fSt12chars_format@@GLIBCXX_3.4.31
  5767: 00000000000ae4a1   899 FUNC    GLOBAL DEFAULT   13 _ZSt20__to_chars_float16_tPcS_fSt12chars_format@@GLIBCXX_3.4.31
   842: 000000000016d430   106 FUNC    LOCAL  DEFAULT   13 _ZN12_GLOBAL__N_113get_ieee_reprINS_23floating_type_float16_tEEENS_6ieee_tIT_EES3_
   865: 0000000000170980  1613 FUNC    LOCAL  DEFAULT   13
+_ZSt23__floating_to_chars_hexIN12_GLOBAL__N_123floating_type_float16_tEESt15to_chars_resultPcS3_T_St8optionalIiE.constprop.0.isra.0
  7205: 00000000000ae824   950 FUNC    GLOBAL DEFAULT   13 _ZSt21__to_chars_bfloat16_tPcS_fSt12chars_format
  7985: 00000000000ae4a1   899 FUNC    GLOBAL DEFAULT   13 _ZSt20__to_chars_float16_tPcS_fSt12chars_format
so 3568 code bytes together or so.

Tested with the attached test (which doesn't prove the shortest
representation, just prints std::{,b}float16_t and std::float32_t
shortest strings side by side, then tries to verify it can be
emitted even into the exact sized range and can't be into range
one smaller than that and tries to read what is printed
back using from_chars float32_t overload (so there could be
double rounding, but apparently there is none for the shortest strings).
The only differences printed are for NaNs, where sNaNs are canonicalized
to canonical qNaNs and as to_chars doesn't print NaN mantissa, even qNaNs
other than the canonical one are read back just as the canonical NaN.

Also attaching what Patrick wrote to generate the pow10_adjustment_tab,
for std::float16_t only 1.0, 10.0, 100.0, 1000.0 and 10000.0 are powers
of 10 in the range because __FLT16_MAX__ is 65504.0, and all of the above
are exactly representable in std::float16_t, so we want to use 0 in
pow10_adjustment_tab.

2022-11-01  Jakub Jelinek  <jakub@redhat.com>

	* include/std/charconv (__to_chars_float16_t, __to_chars_bfloat16_t):
	Declare.
	(to_chars): Add _Float16 and __gnu_cxx::__bfloat16_t overloads.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.31): Export
	_ZSt20__to_chars_float16_tPcS_fSt12chars_format and
	_ZSt21__to_chars_bfloat16_tPcS_fSt12chars_format.
	* src/c++17/floating_to_chars.cc (floating_type_float16_t,
	floating_type_bfloat16_t): New types.
	(floating_type_traits<floating_type_float16_t>,
	floating_type_traits<floating_type_bfloat16_t>,
	get_ieee_repr<floating_type_float16_t>,
	get_ieee_repr<floating_type_bfloat16_t>,
	__handle_special_value<floating_type_float16_t>,
	__handle_special_value<floating_type_bfloat16_t>): New specializations.
	(floating_to_shortest_scientific): Handle floating_type_float16_t
	and floating_type_bfloat16_t like IEEE quad.
	(__floating_to_chars_shortest): For floating_type_bfloat16_t call
	__floating_to_chars_hex<float> rather than
	__floating_to_chars_hex<floating_type_bfloat16_t> to avoid
	instantiating the latter.
	(__to_chars_float16_t, __to_chars_bfloat16_t): New functions.
2022-11-01 13:40:05 +01:00
François Dumont
d26bcff991 libstdc++: [_GLIBCXX_INLINE_VERSION] Cleanup gnu-versioned-namespace.ver
Remove expressions for symbols in std::__detail::__8 namespace, they are obsolete since
version namespace applies only at std:: level, not at sub-levels.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu-versioned-namespace.ver: Remove obsolete std::__detail::__8
	symbols.
2022-09-15 18:58:50 +02:00
Jakub Jelinek
723ef5a937 libstdc++: Outline the overlapping case of string _M_replace into a separate function [PR105329]
The following patch is partially a workaround for bogus warnings
when the compiler isn't able to fold _M_disjunct call into constant
false, but also an optimization attempt - assuming _M_disjunct (__s)
is rare, the patch should shrink code size for the common case and
use library or for non-standard instantiations an out of line
function to handle the rare case.

2022-09-12  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/105329
	* acinclude.m4 (libtool_VERSION): Change to 6:31:0.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.21): Don't export
	std::basic_string methods with name length of 15.
	(GLIBCXX_3.4.31): Export std::basic_string::_M_replace_cold.
	* testsuite/util/testsuite_abi.cc (check_version): Handle
	GLIBCXX_3.4.31.
	* include/bits/basic_string.h (std::basic_string::_M_replace_cold):
	Declare.
	* include/bits/basic_string.tcc (std::basic_string::_M_replace_cold):
	Define and export even for C++20.
	(std::basic_string::_M_replace): Use __builtin_expect, outline
	the overlapping case to _M_replace_cold.
	* configure: Regenerated.
2022-09-12 11:36:58 +02:00
François Dumont
f39fcafbc0 libstdc++: Remove redundant line in versioned namespace linker script
This doesn't match anything.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu-versioned-namespace.ver: Remove
	std::random_device::* pattern.
2022-04-28 10:03:12 +01:00
Jonathan Wakely
2f26b26721 libstdc++: Fix symbol versioning for Solaris 11.3 [PR103407]
The new std::from_chars implementation means that those symbols are now
defined on Solaris 11.3, which lacks uselocale. They were not present in
gcc-11, but the linker script gives them the GLIBCXX_3.4.29 symbol
version because that is the version where they appeared for systems with
uselocale.

This makes the version for those symbols depend on whether uselocale is
available or not, so that they get version GLIBCXX_3.4.30 on targets
where they weren't defined in gcc-11.

In order to avoid needing separate ABI baseline files for Solaris 11.3
and 11.4, the ABI checker program now treats the floating-point
std::from_chars overloads as undesignated if they are not found in the
baseline symbols file. This means they can be left out of the SOlaris
baseline without causing the check-abi target to fail.

libstdc++-v3/ChangeLog:

	PR libstdc++/103407
	* config/abi/pre/gnu.ver: Make version for std::from_chars
	depend on HAVE_USELOCALE macro.
	* testsuite/util/testsuite_abi.cc (compare_symbols): Treat
	std::from_chars for floating-point types as undesignated if
	not found in the baseline symbols file.
2022-03-16 21:16:53 +00:00
Jakub Jelinek
a8d3c98746 libstdc++: Add %j, %U, %w, %W time_get support, fix %y, %Y, %C, %p [PR77760]
glibc strptime passes around some state, what fields in struct tm have been
set and what needs to be finalized through possibly recursive calls, and
at the end performs various finalizations, like applying %p so that it
works for both %I %p and %p %I orders, or applying century so that both
%C %y and %y %C works, or computation of missing fields from others
(e.g. from %Y and %j one can compute tm_mon, tm_mday and tm_wday,
from %Y %U %w, %Y %W %w, %Y %U %a, or %Y %W %w one can compute
tm_mon, tm_mday, tm_yday or e.g. from %Y %m %d one can compute tm_wday
and tm_yday.

As the finalization is quite large and doesn't need to be a template
(doesn't depend on any iterators or char types), I've put it into libstdc++,
and left some padding in the state struct, so that perhaps in the future we
can track some more state without changing ABI.

Unfortunately, there is an ugly problem that the standard mandates that
get method calls the do_get virtual method and I don't see how we can
cary on any state in between those calls (even if we did an ABI change
for the facets, the methods are const, so that I think multiple threads
could use the same time_get objects and we couldn't store state in there).

There is a hack for that for GCC (seems to work with ICC too, doesn't work
with clang++) if the do_get method isn't overriden we can pass the state
around.

For both do_get_year and per IRC discussions also for %y, the behavior is
if 1-2 digits are parsed, the year is treated according to POSIX 2008 %y
rules (0-68 is 2000-2068, 69-99 is 1969-1999), if 3-4 digits are parsed,
it is treated as %Y.

2022-01-10  Jakub Jelinek  <jakub@redhat.com>

	PR libstdc++/77760
	* include/bits/locale_facets_nonio.h (__time_get_state): New struct.
	(time_get::_M_extract_via_format): Declare new method with
	__time_get_state& as an extra argument.
	* include/bits/locale_facets_nonio.tcc (_M_extract_via_format): Add
	__state argument, set various fields in it while parsing.  Handle %j,
	%U, %w and %W, fix up handling of %y, %Y and %C, don't adjust tm_hour
	for %p immediately.  Add a wrapper around the method without the
	__state argument for backwards compatibility.
	(_M_extract_num): Remove all __len == 4 special cases.
	(time_get::do_get_time, time_get::do_get_date, time_get::do_get): Zero
	initialize __state, pass it to _M_extract_via_format and finalize it
	at the end.
	(do_get_year): For 1-2 digit parsed years, map 0-68 to 2000-2068,
	69-99 to 1969-1999.  For 3-4 digit parsed years use that as year.
	(get): If do_get isn't overloaded from the locale_facets_nonio.tcc
	version, don't call do_get but call _M_extract_via_format instead to
	pass around state.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.30): Export _M_extract_via_format
	with extra __time_get_state and __time_get_state::_M_finalize_state.
	* src/c++98/locale_facets.cc (is_leap, day_of_the_week,
	day_of_the_year): New functions in anon namespace.
	(mon_yday): New var in anon namespace.
	(__time_get_state::_M_finalize_state): Define.
	* testsuite/22_locale/time_get/get/char/4.cc: New test.
	* testsuite/22_locale/time_get/get/wchar_t/4.cc: New test.
	* testsuite/22_locale/time_get/get_year/char/1.cc (test01): Parse 197
	as year 197AD instead of error.
	* testsuite/22_locale/time_get/get_year/char/5.cc (test01): Parse 1 as
	year 2001 instead of error.
	* testsuite/22_locale/time_get/get_year/char/6.cc: New test.
	* testsuite/22_locale/time_get/get_year/wchar_t/1.cc (test01): Parse
	197 as year 197AD instead of error.
	* testsuite/22_locale/time_get/get_year/wchar_t/5.cc (test01): Parse
	1 as year 2001 instead of error.
	* testsuite/22_locale/time_get/get_year/wchar_t/6.cc: New test.
2022-01-10 15:38:47 +01:00
Jonathan Wakely
3633cc5428 libstdc++: Implement P1328 "Making std::type_info::operator== constexpr"
This feature is present in the C++23 draft.

With Jakub's recent front-end changes we can implement constexpr
equality by comparing the addresses of std::type_info objects. We do not
need string comparisons, because for constant evaluation cases we know
we aren't dealing with std::type_info objects defined in other
translation units.

The ARM EABI requires that the type_info::operator== function can be
defined out-of-line (and suggests that should be the default), but to be
a constexpr function it must be defined inline (at least for C++23
mode). To meet these conflicting requirements we make the inline version
of operator== call a new __equal function when called at runtime. That
is an alias for the non-inline definition of operator== defined in
libsupc++.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver (GLIBCXX_3.4.30): Export new symbol for
	ARM EABI.
	* include/bits/c++config (_GLIBCXX23_CONSTEXPR): Define.
	* include/std/version (__cpp_lib_constexpr_typeinfo): Define.
	* libsupc++/tinfo.cc: Add #error to ensure non-inline definition
	is emitted.
	(type_info::__equal): Define alias symbol.
	* libsupc++/typeinfo (type_info::before): Combine different
	implementations into one.
	(type_info::operator==): Likewise. Use address equality for
	constant evaluation. Call __equal for targets that require the
	definition to be non-inline.
	* testsuite/18_support/type_info/constexpr.cc: New test.
2022-01-05 14:43:01 +00:00
Jakub Jelinek
7adcbafe45 Update copyright years. 2022-01-03 10:42:10 +01:00
Jakub Jelinek
982a2c9b78 libstdc++: Add std::time_get %r support [PR71367]
This incremental patch adds std::time_get %r support (%p was added already
in the previous patch).  The _M_am_fm_format method previously in the header
unfortunately had wrong arguments and so was useless, so the largest
complication in this patch is exporting a new symbol in the right symbol
version.

2021-12-10  Jakub Jelinek  <jakub@redhat.com>

	PR libstdc++/71367
	* config/locale/dragonfly/time_members.cc (_M_initialize_timepunct):
	Initialize "C" _M_am_pm_format to %I:%M:%S %p rather than empty
	string.
	* config/locale/gnu/time_members.cc (_M_initialize_timepunct):
	Likewise.
	* config/locale/generic/time_members.cc (_M_initialize_timepunct):
	Likewise.
	* include/bits/locale_facets_nonio.h (_M_am_pm_format): New method.
	* include/bits/locale_facets_nonio.tcc (_M_extract_via_format): Handle
	%r.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.30): Export _M_am_pm_format
	with const _CharT** argument, ensure it isn't exported in GLIBCXX_3.4.
	* testsuite/22_locale/time_get/get/char/71367.cc: New test.
	* testsuite/22_locale/time_get/get/wchar_t/71367.cc: New test.
2021-12-10 17:05:04 +01:00
Jonathan Wakely
9e18a25331 libstdc++: Allow std::condition_variable waits to be cancelled [PR103382]
std::condition_variable::wait(unique_lock<mutex>&) is incorrectly marked
noexcept, which means that the __forced_unwind exception used by NPTL
cancellation will terminate the process. It should allow exceptions to
pass through, so that a thread can be cleanly cancelled when waiting on
a condition variable.

The new behaviour is exported as a new version of the symbol, to avoid
an ABI break for existing code linked to the non-throwing definition of
the function. Code linked against older releases will have a reference
to the @GLIBCXX_3.4.11 version, andcode compiled against the new
libstdc++ will get a reference to the @@GLIBCXX_3.4.30 version.

libstdc++-v3/ChangeLog:

	PR libstdc++/103382
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.11): Do not export old
	symbol if .symver renaming is supported.
	(GLIBCXX_3.4.30): Export new symbol if .symver renaming is
	supported.
	* doc/xml/manual/evolution.xml: Document change.
	* doc/html/manual/api.html: Regenerate.
	* include/bits/std_mutex.h (__condvar::wait, __condvar::wait_until):
	Remove noexcept.
	* include/std/condition_variable (condition_variable::wait):
	Likewise.
	* src/c++11/condition_variable.cc (condition_variable::wait):
	Likewise.
	* src/c++11/compatibility-condvar.cc (__nothrow_wait_cv::wait):
	Define nothrow wrapper around std::condition_variable::wait and
	export the old symbol as an alias to it.
	* testsuite/30_threads/condition_variable/members/103382.cc: New test.
2021-12-09 22:58:19 +00:00
Jonathan Wakely
a54ce8865a libstdc++: Print assertion messages to stderr [PR59675]
This replaces the printf used by failed debug assertions with fprintf,
so we can write to stderr.

To avoid including <stdio.h> the assert function is moved into the
library. To avoid programs using a vague linkage definition of the old
inline function, the function is renamed. Code compiled with old
versions of GCC might still call the old function, but code compiled
with the newer GCC will call the new function and write to stderr.

libstdc++-v3/ChangeLog:

	PR libstdc++/59675
	* acinclude.m4 (libtool_VERSION): Bump version.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.30): Add version and
	export new symbol.
	* configure: Regenerate.
	* include/bits/c++config (__replacement_assert): Remove, declare
	__glibcxx_assert_fail instead.
	* src/c++11/debug.cc (__glibcxx_assert_fail): New function to
	replace __replacement_assert, writing to stderr instead of
	stdout.
	* testsuite/util/testsuite_abi.cc: Update latest version.
2021-11-12 12:23:10 +00:00
Jonathan Wakely
995a740cb0 libstdc++: Remove symbols for new std::call_once implementation [PR 99341]
This removes the new symbols added for the new futex-based
std::call_once implementation. These symbols were new on trunk, so not
in any released version. However, they are already present in some
beta distro releases (Fedora Linux 34) and in Fedora Linux rawhide. This
change can be locally reverted by distros that need to keep the symbols
present until affected packages have been rebuilt.

libstdc++-v3/ChangeLog:

	PR libstdc++/99341
	* config/abi/post/aarch64-linux-gnu/baseline_symbols.txt: Remove
	std::once_flag symbols.
	* config/abi/post/ia64-linux-gnu/baseline_symbols.txt: Likewise.
	* config/abi/post/m68k-linux-gnu/baseline_symbols.txt: Likewise.
	* config/abi/post/riscv64-linux-gnu/baseline_symbols.txt:
	Likewise.
	* config/abi/pre/gnu.ver: Likewise.
	* src/c++11/mutex.cc [_GLIBCXX_HAVE_LINUX_FUTEX]
	(struct __once_flag_compat): Remove.
	(_ZNSt9once_flag11_M_activateEv): Remove.
	(_ZNSt9once_flag9_M_finishEb): Remove.
2021-03-16 12:25:28 +00:00
Jonathan Wakely
f90027d18a libstdc++: Define std::to_chars overloads for __ieee128 [PR 98389]
This adds overloads of std::to_chars for powerpc64's __ieee128, so that
std::to_chars can be used for long double when -mabi=ieeelongdouble is
in used.

Eventually we'll want to extend these new overloads to work for
__float128 on all targets that support that type. For now, we're only
doing it for powerpc64 when the new long double type is supported in
parallel to the old long double type.

Additionally the existing std::to_chars overloads for long double
are given the right symbol version, resolving PR libstdc++/98389.

libstdc++-v3/ChangeLog:

	PR libstdc++/98389
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.29): Do not match to_chars
	symbols for long double arguments mangled as 'g'.
	* config/os/gnu-linux/ldbl-extra.ver: Likewise.
	* config/os/gnu-linux/ldbl-ieee128-extra.ver: Likewise.
	* src/c++17/Makefile.am [GLIBCXX_LDBL_ALT128_COMPAT_TRUE]:
	Use -mabi=ibmlongdouble for floating_to_chars.cc.
	* src/c++17/Makefile.in: Regenerate.
	* src/c++17/floating_to_chars.cc (floating_type_traits_binary128):
	New type defining type traits of IEEE binary128 format.
	(floating_type_traits<__float128>): Define specialization.
	(floating_type_traits<long double>): Define in terms of
	floating_type_traits_binary128 when appropriate.
	(floating_to_shortest_scientific): Handle __float128.
	(sprintf_ld): New function template for printing a long double
	or __ieee128 value using sprintf.
	(__floating_to_chars_shortest, __floating_to_chars_precision):
	Use sprintf_ld.
	(to_chars): Define overloads for __float128.
2021-02-24 16:34:06 +00:00
Jakub Jelinek
99dee82307 Update copyright years. 2021-01-04 10:26:59 +01:00
Patrick Palka
3c57e69235 libstdc++: Add floating-point std::to_chars implementation
This implements the floating-point std::to_chars overloads for float,
double and long double.  We use the Ryu library to compute the shortest
round-trippable fixed and scientific forms for float, double and long
double.  We also use Ryu for performing explicit-precision fixed and
scientific formatting for float and double. For explicit-precision
formatting for long double we fall back to using printf.  Hexadecimal
formatting for float, double and long double is implemented from
scratch.

The supported long double binary formats are binary64, binary80 (x86
80-bit extended precision), binary128 and ibm128.

Much of the complexity of the implementation is in computing the exact
output length before handing it off to Ryu (which doesn't do bounds
checking).  In some cases it's hard to compute the output length
beforehand, so in these cases we instead compute an upper bound on the
output length and use a sufficiently-sized intermediate buffer only if
necessary.

Another source of complexity is in the general-with-precision formatting
mode, where we need to do zero-trimming of the string returned by Ryu,
and where we also take care to avoid having to format the number through
Ryu a second time when the general formatting mode resolves to fixed
(which we determine by doing a scientific formatting first and
inspecting the scientific exponent).  We avoid going through Ryu twice
by instead transforming the scientific form to the corresponding fixed
form via in-place string manipulation.

This implementation is non-conforming in a couple of ways:

1. For the shortest hexadecimal formatting, we currently follow the
   Microsoft implementation's decision to be consistent with the
   output of printf's '%a' specifier at the expense of sometimes not
   printing the shortest representation.  For example, the shortest hex
   form for the number 1.08p+0 is 2.1p-1, but we output the former
   instead of the latter, as does printf.

2. The Ryu routine generic_binary_to_decimal that we use for performing
   shortest formatting for large floating point types is implemented
   using the __int128 type, but some targets with a large long double
   type lack __int128 (e.g. i686), so we can't perform shortest
   formatting of long double on such targets through Ryu.  As a
   temporary stopgap this patch makes the long double to_chars overloads
   just dispatch to the double overloads on these targets, which means
   we lose precision in the output.  (We could potentially fix this by
   writing a specialized version of Ryu's generic_binary_to_decimal
   routine that uses uint64_t instead of __int128.)  [Though I wonder if
   there's a better way to work around the lack of __int128 on i686
   specifically?]

3. Our shortest formatting for __ibm128 doesn't guarantee the round-trip
   property if the difference between the high- and low-order exponent
   is large.  This is because we treat __ibm128 as if it has a
   contiguous 105-bit mantissa by merging the mantissas of the high-
   and low-order parts (using code extracted from glibc), so we
   potentially lose precision from the low-order part.  This seems to be
   consistent with how glibc printf formats __ibm128.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver: Add new exports.
	* include/std/charconv (to_chars): Declare the floating-point
	overloads for float, double and long double.
	* src/c++17/Makefile.am (sources): Add floating_to_chars.cc.
	* src/c++17/Makefile.in: Regenerate.
	* src/c++17/floating_to_chars.cc: New file.
	(to_chars): Define for float, double and long double.
	* testsuite/20_util/to_chars/long_double.cc: New test.
2020-12-17 23:11:34 -05:00
Jonathan Wakely
7c1e7eed89 libstdc++: Add C++ runtime support for new 128-bit long double format
This adds support for the new __ieee128 long double format on
powerpc64le targets.

Most of the complexity comes from wanting a single libstdc++.so library
that contains the symbols needed by code compiled with both
-mabi=ibmlongdouble and -mabi=ieeelongdouble (and not forgetting
-mlong-double-64 as well!)

In a few places this just requires an extra overload, for example
std::from_chars has to be overloaded for both forms of long double.
That can be done in a single translation unit that defines overloads
for 'long double' and also '__ieee128', so that user code including
<charconv> will be able to link to a definition for either type of long
double. Those are the easy cases.

The difficult parts are (as for the std::string ABI transition) the I/O
and locale facets. In order to be able to write either form of long
double to an ostream such as std::cout we need the locale to contain a
std::num_put facet that can handle both forms. The same approach is
taken as was already done for supporting 64-bit long double and 128-bit
long double: adding extra overloads of do_put to the facet class. On
targets where the new long double code is enabled, the facets that are
registered in the locale at program startup have additional overloads so
that they can work with any long double type. Where this fails to work
is if user code installs its own facet, which will probably not have the
additional overloads and so will only be able to output one or the other
type. In practice the number of users expecting to be able to use their
own locale facets in code using a mix of -mabi=ibmlongdouble and
-mabi=ieeelongdouble is probably close to zero.

libstdc++-v3/ChangeLog:

	* Makefile.in: Regenerate.
	* config.h.in: Regenerate.
	* config/abi/pre/gnu.ver: Make patterns less greedy.
	* config/os/gnu-linux/ldbl-ieee128-extra.ver: New file with patterns
	for IEEE128 long double symbols.
	* configure: Regenerate.
	* configure.ac: Enable alternative 128-bit long double format on
	powerpc64*-*-linux*.
	* doc/Makefile.in: Regenerate.
	* fragment.am: Regenerate.
	* include/Makefile.am: Set _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT.
	* include/Makefile.in: Regenerate.
	* include/bits/c++config: Define inline namespace for new long
	double symbols. Don't define _GLIBCXX_USE_FLOAT128 when it's the
	same type as long double.
	* include/bits/locale_classes.h [_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT]
	(locale::_Impl::_M_init_extra_ldbl128): Declare new member function.
	* include/bits/locale_facets.h (_GLIBCXX_NUM_FACETS): Simplify by
	only counting narrow character facets.
	(_GLIBCXX_NUM_CXX11_FACETS): Likewise.
	(_GLIBCXX_NUM_LBDL_ALT128_FACETS): New.
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT] (num_get::__do_get): Define
	vtable placeholder for __ibm128 long double type.
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(num_get::__do_get): Declare vtable placeholder for __ibm128 long
	double type.
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(num_put::__do_put): Likewise.
	* include/bits/locale_facets.tcc
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(num_get::__do_get, num_put::__do_put): Define.
	* include/bits/locale_facets_nonio.h
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(money_get::__do_get): Declare vtable placeholder for __ibm128 long
	double type.
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(money_put::__do_put): Likewise.
	* include/bits/locale_facets_nonio.tcc
	[_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __LONG_DOUBLE_IEEE128__]
	(money_get::__do_get, money_put::__do_put): Define.
	* include/ext/numeric_traits.h [_GLIBCXX_LONG_DOUBLE_ALT128_COMPAT]
	(__numeric_traits<__ibm128>, __numeric_traits<__ieee128>): Define.
	* libsupc++/Makefile.in: Regenerate.
	* po/Makefile.in: Regenerate.
	* python/Makefile.in: Regenerate.
	* src/Makefile.am: Add compatibility-ldbl-alt128.cc and
	compatibility-ldbl-alt128-cxx11.cc sources and recipes for objects.
	* src/Makefile.in: Regenerate.
	* src/c++11/Makefile.in: Regenerate.
	* src/c++11/compatibility-ldbl-alt128-cxx11.cc: New file defining
	symbols using the old 128-bit long double format, for the cxx11 ABI.
	* src/c++11/compatibility-ldbl-alt128.cc: Likewise, for the
	gcc4-compatible ABI.
	* src/c++11/compatibility-ldbl-facets-aliases.h: New header for long
	double compat aliases.
	* src/c++11/cow-locale_init.cc: Add comment.
	* src/c++11/cxx11-locale-inst.cc: Define C and C_is_char
	unconditionally.
	* src/c++11/cxx11-wlocale-inst.cc: Add sanity check. Include
	locale-inst.cc directly, not via cxx11-locale-inst.cc.
	* src/c++11/locale-inst-monetary.h: New header for monetary
	category instantiations.
	* src/c++11/locale-inst-numeric.h: New header for numeric category
	instantiations.
	* src/c++11/locale-inst.cc: Include new headers for monetary,
	numeric, and long double definitions.
	* src/c++11/wlocale-inst.cc: Remove long double compat aliases that
	are defined in new header now.
	* src/c++17/Makefile.am: Use -mabi=ibmlongdouble for
	floating_from_chars.cc.
	* src/c++17/Makefile.in: Regenerate.
	* src/c++17/floating_from_chars.cc (from_chars_impl): Add
	if-constexpr branch for __ieee128.
	(from_chars): Overload for __ieee128.
	* src/c++20/Makefile.in: Regenerate.
	* src/c++98/Makefile.in: Regenerate.
	* src/c++98/locale_init.cc (num_facets): Adjust calculation.
	(locale::_Impl::_Impl(size_t)): Call _M_init_extra_ldbl128.
	* src/c++98/localename.cc (num_facets): Adjust calculation.
	(locale::_Impl::_Impl(const char*, size_t)): Call
	_M_init_extra_ldbl128.
	* src/filesystem/Makefile.in: Regenerate.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/util/testsuite_abi.cc: Add new symbol versions.
	Allow new symbols to be added to GLIBCXX_IEEE128_3.4.29 and
	CXXABI_IEEE128_1.3.13 too.
	* testsuite/26_numerics/complex/abi_tag.cc: Add u9__ieee128 to
	regex matching expected symbols.
2020-12-16 23:25:01 +00:00
Jonathan Wakely
95cb0fc8c5 libstdc++: Add remaining C++20 additions to <sstream> [P0408R7]
This adds the new overloads of basic_stringbuf::str, and the
corresponding overloads to basic_istringstream, basic_ostringstream and
basic_stringstream.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver (GLIBCXX_3.4.21): Tighten patterns.
	(GLIBCXX_3.4.29): Export new symbols.
	* include/bits/alloc_traits.h (__allocator_like): New concept.
	* include/std/sstream (basic_stringbuf::swap): Add exception
	specification.
	(basic_stringbuf::str() const): Add ref-qualifier. Use new
	_M_high_mark function.
	(basic_stringbuf::str(const SAlloc&) const): Define new function.
	(basic_stringbuf::str() &&): Likewise.
	(basic_stringbuf::str(const basic_string<C,T,SAlloc>&)):
	Likewise.
	(basic_stringbuf::str(basic_string<C,T,Alloc>&&)): Likewise.
	(basic_stringbuf::view() const): Use _M_high_mark.
	(basic_istringstream::str, basic_ostringstream::str)
	(basic_stringstream::str): Define new overloads.
	* src/c++20/sstream-inst.cc (basic_stringbuf::str)
	(basic_istringstream::str, basic_ostringstream::str)
	(basic_stringstream::str): Explicit instantiation definitions
	for new overloads.
	* testsuite/27_io/basic_istringstream/view/char/1.cc: Add more
	checks.
	* testsuite/27_io/basic_istringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_ostringstream/view/char/1.cc:
	Likewise.
	* testsuite/27_io/basic_ostringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_stringstream/view/char/1.cc:
	Likewise.
	* testsuite/27_io/basic_stringstream/view/wchar_t/1.cc:
	Likewise.
	* testsuite/27_io/basic_istringstream/str/char/2.cc: New test.
	* testsuite/27_io/basic_istringstream/str/wchar_t/2.cc: New test.
	* testsuite/27_io/basic_ostringstream/str/char/3.cc: New test.
	* testsuite/27_io/basic_ostringstream/str/wchar_t/3.cc: New test.
	* testsuite/27_io/basic_stringbuf/str/char/4.cc: New test.
	* testsuite/27_io/basic_stringbuf/str/wchar_t/4.cc: New test.
	* testsuite/27_io/basic_stringstream/str/char/5.cc: New test.
	* testsuite/27_io/basic_stringstream/str/wchar_t/5.cc.cc: New test.
2020-11-10 19:22:47 +00:00
Jonathan Wakely
887515acd2 libstdc++: Fix symbol version conflict in linker script
The change in r11-4748-50b840ac5e1d6534e345c3fee9a97ae45ced6bc7 causes
a build error on Solaris, due to the new explicit instantiation matching
patterns for two different symbol versions.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver (GLIBCXX_3.4.21): Tighten up patterns
	for basic_stringbuf that refer to __xfer_bufptrs.
2020-11-06 20:14:03 +00:00
Jonathan Wakely
50b840ac5e libstdc++: Export basic_stringbuf constructor [PR 97729]
libstdc++-v3/ChangeLog:

	PR libstdc++/97729
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.29): Add exports.
	* src/c++20/sstream-inst.cc (basic_stringbuf): Instantiate
	private constructor taking __xfer_bufptrs.
2020-11-05 18:01:25 +00:00
François Dumont
12d0512305 libstdc++: Add mising gnu-versioned-namespace symbols
libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu-versioned-namespace.ver:
	Add __istream_extract and _Safe_local_iterator_base::_M_attach_single
	symbols.
2020-11-03 22:01:55 +01:00
Jonathan Wakely
93e79ed391 libstdc++: Rewrite std::call_once to use futexes [PR 66146]
The current implementation of std::call_once uses pthread_once, which
only meets the C++ requirements when compiled with support for
exceptions. For most glibc targets and all non-glibc targets,
pthread_once does not work correctly if the init_routine exits via an
exception. The pthread_once_t object is left in the "active" state, and
any later attempts to run another init_routine will block forever.

This change makes std::call_once work correctly for Linux targets, by
replacing the use of pthread_once with a futex, based on the code from
__cxa_guard_acquire. For both glibc and musl, the Linux implementation
of pthread_once is already based on futexes, and pthread_once_t is just
a typedef for int, so this change does not alter the layout of
std::once_flag. By choosing the values for the int appropriately, the
new code is even ABI compatible. Code that calls the old implementation
of std::call_once will use pthread_once to manipulate the int, while new
code will use the new std::once_flag members to manipulate it, but they
should interoperate correctly. In both cases, the int is initially zero,
has the lowest bit set when there is an active execution, and equals 2
after a successful returning execution. The difference with the new code
is that exceptional exceptions are correctly detected and the int is
reset to zero.

The __cxa_guard_acquire code (and musl's pthread_once) use an additional
state to say there are other threads waiting. This allows the futex wake
syscall to be skipped if there is no contention. Glibc doesn't use a
waiter bit, so we have to unconditionally issue the wake in order to be
compatible with code calling the old std::call_once that uses Glibc's
pthread_once. If we know that we're using musl (and musl's pthread_once
doesn't change) it would be possible to set a waiting state and check
for it in std::once_flag::_M_finish(bool), but this patch doesn't do
that.

This doesn't fix the bug for non-linux targets. A similar approach could
be used for targets where we know the definition of pthread_once_t is a
mutex and an integer. We could make once_flag._M_activate() use
pthread_mutex_lock on the mutex member within the pthread_once_t, and
then only set the integer if the execution finishes, and then unlock the
mutex. That would require careful study of each target's pthread_once
implementation and that work is left for a later date.

This also fixes PR 55394 because pthread_once is no longer needed, and
PR 84323 because the fast path is now just an atomic load.

As a consequence of the new implementation that doesn't use
pthread_once, we can also make std::call_once work for targets with no
gthreads support. The code for the single-threaded implementation
follows the same methods as on Linux, but with no need for atomics or
futexes.

libstdc++-v3/ChangeLog:

	PR libstdc++/55394
	PR libstdc++/66146
	PR libstdc++/84323
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.29): Add new symbols.
	* include/std/mutex [!_GLIBCXX_HAS_GTHREADS] (once_flag): Define
	even when gthreads is not supported.
	(once_flag::_M_once) [_GLIBCXX_HAVE_LINUX_FUTEX]: Change type
	from __gthread_once_t to int.
	(once_flag::_M_passive(), once_flag::_M_activate())
	(once_flag::_M_finish(bool), once_flag::_Active_execution):
	Define new members for futex and non-threaded implementation.
	[_GLIBCXX_HAS_GTHREADS] (once_flag::_Prepare_execution): New
	RAII helper type.
	(call_once): Use new members of once_flag.
	* src/c++11/mutex.cc (std::once_flag::_M_activate): Define.
	(std::once_flag::_M_finish): Define.
	* testsuite/30_threads/call_once/39909.cc: Do not require
	gthreads.
	* testsuite/30_threads/call_once/49668.cc: Likewise.
	* testsuite/30_threads/call_once/60497.cc: Likewise.
	* testsuite/30_threads/call_once/call_once1.cc: Likewise.
	* testsuite/30_threads/call_once/dr2442.cc: Likewise.
	* testsuite/30_threads/call_once/once_flag.cc: Add test for
	constexpr constructor.
	* testsuite/30_threads/call_once/66146.cc: New test.
	* testsuite/30_threads/call_once/constexpr.cc: Removed.
	* testsuite/30_threads/once_flag/cons/constexpr.cc: Removed.
2020-11-03 18:44:49 +00:00
Jonathan Wakely
ffe6b41015 libstdc++: Fix linker script to remove conflicting patterns
This should fix a bootstrap error on Solaris, due to some of the new
symbols matching old patterns as well as new ones.

libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver (GLIBCXX_3.4.21): Tighten patterns
	for old <sstream> symbols some more.
2020-10-29 22:47:22 +00:00
Jonathan Wakely
f4f9364d20 libstdc++: Fix linker script
libstdc++-v3/ChangeLog:

	* config/abi/pre/gnu.ver (GLIBCXX_3.4.29): Remove duplicate
	patterns.
	(CXXABI_1.3.13): Restore missing piece.
2020-10-28 23:52:12 +00:00
Thomas Rodgers
a0e4d7b44c libstdc++: Implement C++20 features for <sstream>
New ctors and ::view() accessor for -
  * basic_stingbuf
  * basic_istringstream
  * basic_ostringstream
  * basic_stringstreamm

New ::get_allocator() accessor for basic_stringbuf.

libstdc++-v3/ChangeLog:
	* acinclude.m4 (glibcxx_SUBDIRS): Add src/c++20.
	* config/abi/pre/gnu.ver (GLIBCXX_3.4.29): New symbols.
	* configure: Regenerate.
	* include/std/sstream:
	(basic_stringbuf::basic_stringbuf(allocator const&)): New constructor.
	(basic_stringbuf::basic_stringbuf(openmode, allocator const&)): Likewise.
	(basic_stringbuf::basic_stringbuf(basic_string&&, openmode)): Likewise.
	(basic_stringbuf::basic_stringbuf(basic_stringbuf&&, allocator const&)):
	Likewise.
	(basic_stringbuf::get_allocator()): New method.
	(basic_stringbuf::view()): Likewise.
	(basic_istringstream::basic_istringstream(basic_string&&, openmode)):
	New constructor.
	(basic_istringstream::basic_istringstream(openmode, allocator const&)):
	Likewise
	(basic_istringstream::view()): New method.
	(basic_ostringstream::basic_ostringstream(basic_string&&, openmode)):
	New constructor.
	(basic_ostringstream::basic_ostringstream(openmode, allocator const&)):
	Likewise
	(basic_ostringstream::view()): New method.
	(basic_stringstream::basic_stringstream(basic_string&&, openmode)):
	New constructor.
	(basic_stringstream::basic_stringstream(openmode, allocator const&)):
	Likewise
	(basic_stringstream::view()): New method.
	* src/Makefile.in: Add c++20 directory.
	* src/Makefile.am: Regenerate.
	* src/c++20/Makefile.am: Add makefile for new sub-directory.
	* src/c++20/Makefile.in: Generate.
	* src/c++20/sstream-inst.cc: New file defining explicit
	instantiations for basic_stringbuf, basic_istringstream,
	basic_ostringstream, and basic_stringstream member functions
	added in C++20.
	* testsuite/27_io/basic_stringbuf/cons/char/2.cc: New test.
	* testsuite/27_io/basic_stringbuf/cons/wchar_t/2.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/view/wchar_t/1.cc: Likewise.
	* testsuite/27_io/basic_istringstream/cons/char/1.cc: Likewise.
	* testsuite/27_io/basic_istringstream/cons/wchar_t/1.cc: Likewise.
	* testsuite/27_io/basic_istringstream/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_istringstream/view/wchar_t/1.cc: Likewise.
	* testsuite/27_io/basic_ostringstream/cons/char/1.cc: Likewise.
	* testsuite/27_io/basic_ostringstream/cons/wchar_t/1.cc: Likewise.
	* testsuite/27_io/basic_ostringstream/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_ostringstream/view/wchar_t/1.cc: Likewise.
	* testsuite/27_io/basic_stringstream/cons/char/1.cc: Likewise.
	* testsuite/27_io/basic_stringstream/cons/wchar_t/1.cc: Likewise.
	* testsuite/27_io/basic_stringstream/view/char/1.cc: Likewise.
	* testsuite/27_io/basic_stringstream/view/wchar_t/1.cc: Likewise.
2020-10-28 11:56:06 -07:00