The compiler warns about the loop in deque::_M_range_initialize because
it doesn't know that the number of nodes has already been correctly
sized to match the size of the input. Use __builtin_unreachable to tell
it that the loop will never be entered if the number of elements is
smaller than a single node.
libstdc++-v3/ChangeLog:
PR libstdc++/100516
* include/bits/deque.tcc (_M_range_initialize<ForwardIterator>):
Add __builtin_unreachable to loop.
* testsuite/23_containers/deque/100516.cc: New test.
When (bound - i) or n is the most negative value of its type, the
negative of the value will overflow. Instead of abs(n) >= abs(bound - i)
use n >= (bound - i) when positive and n <= (bound - i) when negative.
The function has a precondition that they must have the same sign, so
this works correctly. The precondition check can be moved into the else
branch, and simplified.
The standard requires calling ranges::advance(i, bound) even if i==bound
is already true, which is technically observable, but that's pointless.
We can just return n in that case. Similarly, for i!=bound but n==0 we
are supposed to call ranges::advance(i, n), but that's pointless. An LWG
issue to allow omitting the pointless calls is expected to be filed.
libstdc++-v3/ChangeLog:
* include/bits/ranges_base.h (ranges::advance): Avoid signed
overflow. Do nothing if already equal to desired result.
* testsuite/24_iterators/range_operations/advance_overflow.cc:
New test.
With -fno-exceptions we get a -Wmisleading-indentation warning for:
if (cond)
__try {}
__catch (...) {}
This is because the __catch(...) expands to if (false), but is indented
as though it is controlled by the preceding 'if'. Surround it in braces.
The new make_shared<T[]> code triggers a bogus warning due to PR 61596,
which can be disabled with a pragma.
libstdc++-v3/ChangeLog:
PR libstdc++/104019
* include/bits/istream.tcc (basic_istream::sentry): Add braces
around try-block.
* include/bits/shared_ptr_base.h (_Sp_counted_array_base::_M_init):
Add pragmas to disable bogus warnings from PR 61596.
For GNU/Linux G++ defines _GNU_SOURCE automatically, but not for Cygwin.
This means secure_getenv is not declared by Cygwin's <stdlib.h>, even
though autoconf detected it is present in the library. Define it in the
source files that want to use secure_getenv.
libstdc++-v3/ChangeLog:
PR libstdc++/104217
* src/c++17/fs_ops.cc (_GNU_SOURCE): Define.
* src/filesystem/dir.cc (_GNU_SOURCE): Define.
* src/filesystem/ops.cc (_GNU_SOURCE): Define.
This adds a new internal flag to the filesystem::directory_iterator
constructor that makes it fail if the path is a symlink that resolves to
a directory. This prevents filesystem::remove_all from following a
symlink to a directory, rather than deleting the symlink itself.
We can also use that new flag in recursive_directory_iterator to ensure
that we don't follow symlinks if the follow_directory_symlink option is
not set.
This also moves an error check in filesystem::remove_all after the while
loop, so that errors from the directory_iterator constructor are
reproted, instead of continuing to the filesystem::remove call below.
libstdc++-v3/ChangeLog:
PR libstdc++/104161
* acinclude.m4 (GLIBCXX_CHECK_FILESYSTEM_DEPS): Check for
fdopendir.
* config.h.in: Regenerate.
* configure: Regenerate.
* src/c++17/fs_dir.cc (_Dir): Add nofollow flag to constructor
and pass it to base class constructor.
(directory_iterator): Pass nofollow flag to _Dir constructor.
(fs::recursive_directory_iterator::increment): Likewise.
* src/c++17/fs_ops.cc (do_remove_all): Use nofollow option for
directory_iterator constructor. Move error check outside loop.
* src/filesystem/dir-common.h (_Dir_base): Add nofollow flag to
constructor and when it's set use ::open with O_NOFOLLOW and
O_DIRECTORY.
* src/filesystem/dir.cc (_Dir): Add nofollow flag to constructor
and pass it to base class constructor.
(directory_iterator): Pass nofollow flag to _Dir constructor.
(fs::recursive_directory_iterator::increment): Likewise.
* src/filesystem/ops.cc (remove_all): Use nofollow option for
directory_iterator constructor. Move error check outside loop.
libstdc++-v3/ChangeLog:
PR libstdc++/104032
* include/std/spanstream (basic_spanbuf(basic_spanbuf&&)): Use
mem-initializer for _M_buf.
(basic_spanbuf::Operator=(basic_spanbuf&&)): Fix ill-formed
member access.
* testsuite/27_io/spanstream/2.cc: New test.
We can use the new from_chars implementation when long double and double
have the same representation.
libstdc++-v3/ChangeLog:
* src/c++17/floating_from_chars.cc (USE_STRTOD_FOR_FROM_CHARS):
Define macro for case where std::from_chars is implemented in
terms of strtod, strtof or strtold.
(buffer_resource, valid_fmt, find_end_of_float, pattern)
(from_chars_impl, make_result, reserve_string): Do not define
unless USE_STRTOD_FOR_FROM_CHARS is defined.
(from_chars): Define when at least one of USE_LIB_FAST_FLOAT and
USE_STRTOD_FOR_FROM_CHARS is defined, instead of
_GLIBCXX_HAVE_USELOCALE. Use fast_float for long double when it
is binary64.
I broke this unintentionally in r12-4259.
libstdc++-v3/ChangeLog:
PR libstdc++/104174
* include/bits/hashtable_policy.h (_Map_base): Add partial
specialization for maps with const key types.
* testsuite/23_containers/unordered_map/104174.cc: New test.
The non-atomic store that sets both reference counts to zero uses a
type-punned pointer, which has undefined behaviour. We could use memset
to write 8 bytes, but we don't actually need it to be a single store
anyway. No other thread can observe the values, that's why it's safe to
use non-atomic stores in the first place. So we can just set each count
to zero.
With -fstore-merging (which is enabled by default at -O2) GCC produces
the same code for this as for memset or the type punned store. Clang
does that store merging even at -O1.
libstdc++-v3/ChangeLog:
PR libstdc++/104019
* include/bits/shared_ptr_base.h (_Sp_counted_base<>::_M_release):
Set members to zero without type punning.
I changed the preprocessor condition from <= to < in r12-6574 which
meant the macro was not defined by <version> for C++17.
libstdc++-v3/ChangeLog:
* include/std/version (__cpp_lib_shared_ptr_arrays): Fix
condition for C++17 definition.
Clang doesn't support the __constinit extension that we use pre-C++20,
but it does have its own equivalent attribute that can be used instead.
This makes it a little easier to use Clang to build libstdc++ (which
isn't supported. but is sometimes attempted for esoteric targets).
libstdc++-v3/ChangeLog:
* src/c++11/cxx11-ios_failure.cc (__constinit): Define as
equivalent attribute for Clang.
* src/c++11/future.cc (__constinit): Likewise.
* src/c++11/system_error.cc (__constinit): Likewise.
* src/c++17/memory_resource.cc (__constinit): Likewise.
The MacOS linker warns about -L arguments that don't exist, which causes
all tests to fail for the defauly configuration (because libbacktrace
isn't built).
libstdc++-v3/ChangeLog:
* scripts/testsuite_flags.in: Only add src/filesystem/.libs and
src/libbacktrace/.libs to LDFLAGS if those directories exist.
The default is -gdwarf-5 now, so this is hurting rather than improving
things.
libstdc++-v3/ChangeLog:
* configure.ac (GLIBCXX_ENABLE_DEBUG_FLAGS): Remove -gdwarf-4
from default flags.
* configure: Regenerate.
This makes it possible to combine --enable-libstdcxx-debug with
--enable-libstdcxx-backtrace, by adding a rule to src/Makefile to copy
the backtrace-supported.h header into the src/debug/libbacktrace
directory.
Add libbacktrace path to testsuite flags so the tests can link without
having the library installed.
Also fix some warnings when running automake for the libbacktrace
makefile.
Use a per-library CPPFLAGS variable to fix:
src/libbacktrace/Makefile.am:38: warning: AM_CPPFLAGS multiply defined in condition TRUE ...
fragment.am:43: ... 'AM_CPPFLAGS' previously defined here
src/libbacktrace/Makefile.am:32: 'fragment.am' included from here
Create symlinks to the libbacktrace sources to fix:
src/libbacktrace/Makefile.am:55: warning: source file '../../../libbacktrace/atomic.c' is in a subdirectory,
src/libbacktrace/Makefile.am:55: but option 'subdir-objects' is disabled
libstdc++-v3/ChangeLog:
* scripts/testsuite_flags.in: Add src/libbacktrace/.libs to
linker search paths.
* src/Makefile.am: Fix src/debug/libbacktrace build.
* src/Makefile.in: Regenerate.
* src/libbacktrace/Makefile.am: Use per-library CPPFLAGS
variable. Use symlinks for the source files.
* src/libbacktrace/Makefile.in: Regenerate.
Use SFINAE magic to support: "It is unspecified whether math_errhandling
is a macro or an identifier with external linkage." [C Standard]
Signed-off-by: Matthias Kretz <m.kretz@gsi.de>
libstdc++-v3/ChangeLog:
* include/experimental/bits/simd.h (__floating_point_flags): Do
not rely on math_errhandling to expand to a constant expression.
This was deprecated in C++17, not C++14.
libstdc++-v3/ChangeLog:
* include/bits/stl_tempbuf.h (get_temporary_buffer): Change
_GLIBCXX14_DEPRECATED to _GLIBCXX17_DEPRECATED.
This function is no longer used since r12-6691 and can be removed.
libstdc++-v3/ChangeLog:
* include/bits/stl_pair.h (_PCC::_DeprConsPair): Remove unused
function.
This fixes an on AIX.
The lock function currently just spins, which should be changed to use
back-off, and maybe then _M_val.wait(__current) when supported.
libstdc++-v3/ChangeLog:
PR libstdc++/104101
* include/bits/shared_ptr_atomic.h (_Sp_atomic::_Atomic_count::lock):
Only use __thread_relax if __cpp_lib_atomic_wait is defined.
The new deleted constructors added by P2166R1 are a breaking change,
making previously valid code ill-formed in C++23. As a result, they
should only be defined for C++23 and not for C++11 and up.
libstdc++-v3/ChangeLog:
PR libstdc++/104099
* include/bits/basic_string.h (basic_string(nullptr_t)): Only
define for C++23.
(operator=(nullptr_t)): Likewise.
* include/bits/cow_string.h: Likewise.
* include/std/string_view (basic_string_view(nullptr_t)):
Likewise.
* testsuite/21_strings/basic_string/cons/char/nullptr.cc: Adjust
expected error. Add examples that become ill-formed in C++23.
* testsuite/21_strings/basic_string_view/cons/char/nonnull.cc:
Adjust expected errors.
* testsuite/21_strings/basic_string_view/cons/wchar_t/nonnull.cc:
Likewise.
We should not assume that std::iter_value_t etc. are defined
unconditionally for C++20 mode.
libstdc++-v3/ChangeLog:
PR libstdc++/104098
* include/bits/stl_iterator.h (reverse_iterator): Check
__cpp_lib_concepts instead of __cplusplus.
The deprecated non-standard std::pair constructors that allow
constructing std::pair<move-only-type, pointer-type> from an rvalue and
a literal zero where not sufficiently constrained. They were viable when
constructing std::pair<copyable-type, pointer-type>, and that case
should work fine using the standard constructors.
Replace the constraints on the non-standard constructors so they are
only viable in cases that should actually be ill-formed according to the
standard.
Also rename __null_ptr_constant to __zero_as_null_pointer_constant so it
matches the name of the -Wzero-as-null-pointer-constant warning. Also
make the text of the deprecated warning describe the problem in more
detail.
libstdc++-v3/ChangeLog:
PR libstdc++/101124
* include/bits/stl_pair.h (pair): Adjust constraints on
deprecated constructors accepting literal zero as null pointer
constant. Improve wording of deprecated attribute.
* testsuite/20_util/pair/cons/99957.cc: Check that deprecated
constructors do not cause ambiguities for copyable types.
This patch completes implementation of the C++20 proposal P0482R6 [1] by
adding declarations of std::c8rtomb() and std::mbrtoc8() in <cuchar> if
provided by the C library in <uchar.h>.
This patch addresses feedback provided in response to a previous patch
submission [2].
Autoconf changes determine if the C library declares c8rtomb and mbrtoc8
at global scope when uchar.h is included and compiled with either
-fchar8_t or -std=c++20. New _GLIBCXX_USE_UCHAR_C8RTOMB_MBRTOC8_FCHAR8_T
and _GLIBCXX_USE_UCHAR_C8RTOMB_MBRTOC8_CXX20 configuration macros
reflect the probe results. The <cuchar> header declares these functions
in the std namespace only if available and the _GLIBCXX_USE_CHAR8_T
configuration macro is defined (by default it is defined if the C++20
__cpp_char8_t feature test macro is defined)
Patches to glibc to implement c8rtomb and mbrtoc8 have been submitted [3].
New tests validate the presence of these declarations. The tests pass
trivially if the C library does not provide these functions. Otherwise
they ensure that the functions are declared when <cuchar> is included
and either -fchar8_t or -std=c++20 is enabled.
1]: WG21 P0482R6
"char8_t: A type for UTF-8 characters and strings (Revision 6)"
https://wg21.link/p0482r6
[2]: [PATCH] C++ P0482R6 char8_t: declare std::c8rtomb and std::mbrtoc8
if provided by the C library
https://gcc.gnu.org/pipermail/libstdc++/2021-June/052685.html
[3]: "C++20 P0482R6 and C2X N2653"
[Patch 0/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135061.html
[Patch 1/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135062.html
[Patch 2/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135063.html
[Patch 3/3]:
https://sourceware.org/pipermail/libc-alpha/2022-January/135064.html
libstdc++-v3/ChangeLog:
* acinclude.m4: Define config macros if uchar.h provides
c8rtomb() and mbrtoc8().
* config.h.in: Regenerate.
* configure: Regenerate.
* include/c_compatibility/uchar.h (c8rtomb, mbrtoc8): Define.
* include/c_global/cuchar (c8rtomb, mbrtoc8): Likewise.
* include/c_std/cuchar (c8rtomb, mbrtoc8): Likewise.
* testsuite/21_strings/headers/cuchar/functions_std_cxx20.cc:
New test.
* testsuite/21_strings/headers/cuchar/functions_std_fchar8_t.cc:
New test.
This adds the C++23 <stdatomic.h> header, as proposed by P0943R6, for
compatibility with C code.
There are still some ABI differences between atomic_xxx in C and C++
std::atomic_xxx in C++, so this only provides source compatibility, not
binary compatibility.
libstdc++-v3/ChangeLog:
* include/Makefile.am: Install new header.
* include/Makefile.in: Regenerate.
* include/c_compatibility/stdatomic.h: New file.
* testsuite/29_atomics/headers/stdatomic.h/c_compat.cc: New test.
Instead of hardcoded preprocessor conditionals with explicit target
checks, just rely on the fact that __BYTE_ORDER__ is always defined by
GCC.
libstdc++-v3/ChangeLog:
PR libstdc++/104080
* src/c++17/fast_float/LOCAL_PATCHES: Update.
* src/c++17/fast_float/fast_float.h (FASTFLOAT_IS_BIG_ENDIAN):
Define in terms of __BYTE_ORDER__.
This makes our std::from_chars implementation use fast_float for decimal
parsing of binary32/64 numbers. For other floating-point formats we
still use the fallback implementation that goes through the strtod family
of functions.
libstdc++-v3/ChangeLog:
* src/c++17/floating_from_chars.cc: (USE_LIB_FAST_FLOAT):
Conditionally define, and use it to conditionally include
fast_float.
(from_chars): Use fast_float for float and double when
USE_LIB_FAST_FLOAT.
This changes fast_float's handling of overflow/underflow to be
consistent with the standard: instead of returning errc{} and setting
value to +-0 or +-infinity, just return errc::result_out_of_range and
don't modify value, as per [charconv.from.chars]/1.
libstdc++-v3/ChangeLog:
* src/c++17/fast_float/LOCAL_PATCHES: Update.
* src/c++17/fast_float/fast_float.h (from_chars_advanced): In
case of over/underflow, return errc::result_out_of_range and don't
modify 'value'.
This performs the following modifications to our local copy of fast_float
in order to make it more readily usable in our std::from_chars
implementation:
* Remove system #includes
* Replace stray call to assert
* Use the standard chars_format and from_chars_result types
libstdc++-v3/ChangeLog:
* src/c++17/fast_float/LOCAL_PATCHES: Update.
* src/c++17/fast_float/fast_float.h: Apply local modifications.
We're going to use the fast_float library[1] in our (compiled-in)
floating-point std::from_chars implementation for faster and more
portable parsing of binary32/64 decimal strings.
The single file fast_float.h is an amalgamation of the entire library,
which can be (re)generated with the amalgamate.py script (from the
fast_float repository) via the command
python3 ./script/amalgamate.py --license=MIT \
> $GCC_SRC/libstdc++-v3/c++17/fast_float/fast_float.h
The code has a GPL-compatible license.
[1]: https://github.com/fastfloat/fast_float
libstdc++-v3/ChangeLog:
* src/c++17/fast_float/LOCAL_PATCHES: New file.
* src/c++17/fast_float/MERGE: New file.
* src/c++17/fast_float/README.md: New file, copied from the
fast_float repository.
* src/c++17/fast_float/fast_float.h: New file, an amalgamation
of the fast_float library.
Signed-off-by: Patrick Palka <ppalka@redhat.com>
libstdc++-v3/ChangeLog:
* src/c++17/floating_from_chars.cc: Include <bit>.
(ascii_to_hexit, starts_with_ci): Conditionally define.
(__floating_from_chars_hex): Conditionally define.
(from_chars): Use __floating_from_chars_hex for
chars_format::hex parsing of binary32/64 float/double.
(testsuite/20_util/from_chars/7.cc): New test.
Add the <stacktrace> header and a new libstdc++_libbacktrace.a library
that provides the implementation. For now, the new library is only built
if --enable-libstdcxx-backtrace=yes is used. As with the Filesystem TS,
the new library is only provided as a static archive.
libstdc++-v3/ChangeLog:
* acinclude.m4 (GLIBCXX_ENABLE_BACKTRACE): New macro.
* configure.ac: Use GLIBCXX_ENABLE_BACKTRACE.
* include/Makefile.am: Add new header.
* include/Makefile.in: Regenerate.
* include/std/stacktrace: New header.
* include/std/version (__cpp_lib_stacktrace): Define.
* Makefile.in: Regenerate.
* config.h.in: Regenerate.
* configure: Regenerate.
* doc/Makefile.in: Regenerate.
* libsupc++/Makefile.in: Regenerate.
* po/Makefile.in: Regenerate.
* python/Makefile.in: Regenerate.
* src/Makefile.am: Regenerate.
* src/Makefile.in: Regenerate.
* src/c++11/Makefile.in: Regenerate.
* src/c++17/Makefile.in: Regenerate.
* src/c++20/Makefile.in: Regenerate.
* src/c++98/Makefile.in: Regenerate.
* src/filesystem/Makefile.in: Regenerate.
* testsuite/Makefile.in: Regenerate.
* src/libbacktrace/Makefile.am: New file.
* src/libbacktrace/Makefile.in: New file.
* src/libbacktrace/backtrace-rename.h: New file.
* src/libbacktrace/backtrace-supported.h.in: New file.
* src/libbacktrace/config.h.in: New file.
* testsuite/lib/libstdc++.exp (check_effective_target_stacktrace):
New proc.
* testsuite/20_util/stacktrace/entry.cc: New test.
* testsuite/20_util/stacktrace/synopsis.cc: New test.
* testsuite/20_util/stacktrace/version.cc: New test.
