This test no longer has additional errors for C++20 mode, so remove the
dg-error that is now failing, and the unnecessary dg-prune-output.
libstdc++-v3/ChangeLog:
* testsuite/20_util/scoped_allocator/69293_neg.cc: Remove
dg-error for c++20.
This allows std::make_exception_ptr to be used in a translation unit
compiled with -fno-exceptions. This works because the new implementation
added for PR 68297 doesn't need to throw or catch anything. The catch is
there to handle exceptions from the constructor of the exception object,
which we can assume won't happen in a -fno-exceptions TU and so use the
__catch macro instead. If the constructor does throw (because it's
defined in a different TU which was compiled with exceptions enabled)
then that exception will propagate to the make_exception_ptr caller.
That seems acceptable for a program that is trying to mix & match TUs
compiled with and without exceptions, and using types that throw when
constructed. That should be rare, and can't reasonably be expected to
have sensible behaviour.
This also enables the new implementation for targets that use a
non-standard calling convention for the exceptionDestructor callback
(specifically, mingw, which uses __thiscall). All we need to do is mark
the __dest_thunk function template with the right calling convention.
Finally, the useless no-op definition of make_exception_ptr (which is
only used if both RTTI and exceptions are disabled) is marked
always_inline, to ensure that the linker won't keep that definition and
discard the functional ones when both definitions of the function are
present in the link. An alternative would be to add the abi_tag
attribute to the useless definition, but making it always_inline should
work, and it's small enough to always be inlined reliably.
libstdc++-v3/ChangeLog:
PR libstdc++/85813
* libsupc++/exception_ptr.h (__dest_thunk): Add macro for
destructor calling convention.
(make_exception_ptr): Enable non-throwing implementation for
-fno-exceptions and for non-standard calling conventions. Use
always_inline attribute on the useless no-rtti no-exceptions
definition.
* testsuite/18_support/exception_ptr/64241.cc: Add -fno-rtti so
the no-op implementation is still used.
This restores support for std::make_exception_ptr<E&> and for using
std::exception_ptr in C++98.
Because the new non-throwing implementation needs to use std::decay to
handle references the original throwing implementation is used for
C++98.
We also need to change the typeid expression so it doesn't yield the
dynamic type when the function parameter is a reference to a polymorphic
type. Otherwise the new exception object could be caught by any handler
matching the dynamic type, even though the actual exception object is
only a copy of the base class, sliced to the static type.
libstdc++-v3/ChangeLog:
PR libstdc++/103630
* libsupc++/exception_ptr.h (exception_ptr): Fix exception
specifications on inline definitions.
(make_exception_ptr): Decay the template parameter. Use typeid
of the static type.
* testsuite/18_support/exception_ptr/103630.cc: New test.
This implements my P2467R0 proposal to support opening an fstream in
exclusive mode. The new constant is also supported pre-C++23 as
std::ios_base::__noreplace.
This proposal hasn't been approved for C++23 yet, but I am confident it
will be, as this is restoring a feture found in pre-ISO C++ iostreams
implementations (and still present in the MSVC library as _Noreplace).
If the proposal fails for C++23 we can remove the ios::noreplace
name and just keep ios::__noreplace as an extension.
libstdc++-v3/ChangeLog:
PR libstdc++/59769
* config/io/basic_file_stdio.cc (fopen_mode): Add support for
exclusive mode.
* include/bits/ios_base.h (_S_noreplace): Define new enumerator.
(ios_base::__noreplace): Define.
(ios_base::noreplace): Define for C++23.
* include/std/version (__cpp_lib_ios_noreplace): Define.
* testsuite/27_io/basic_ofstream/open/char/noreplace.cc: New test.
* testsuite/27_io/basic_ofstream/open/wchar_t/noreplace.cc: New test.
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.
Inserting a pair<Key, Value> into a map<Key, Value> will allocate a new
node and construct a pair<const Key, Value> in the node, then check if
the Key is already present in the map. That is because pair<Key, Value>
is not the same type as the map's value_type. But it only differs in the
const-qualification on the Key, and so we should be able to do the
lookup directly, without allocating a new node. This avoids allocating
and then deallocating a node for the case where the key is already found
and nothing gets inserted.
We can take this optimization further and lookup the key directly for a
pair<Key, X>, pair<const Key, X>, pair<Key&, X> etc. for any X. A strict
reading of the standard says we can only do this when we know the
allocator won't do anything funky with the value when constructing a
pair<const Key, Value> from a slightly different type. Inserting that
type only requires the value_type to be Cpp17EmplaceInsertable into the
container, and that doesn't have any requirement that the value is
unchanged (unlike Cpp17CopyInsertable and Cpp17MoveInsertable). For that
reason, the optimization is only done for maps using std::allocator.
A similar optimization can be done for map.emplace(key, value) where the
first argument is similar to the key_type and so can be looked up
without allocating a new node and constructing a key_type.
Finally, both of the insert and emplace cases can use the same
optimization when key_type is a scalar type and some other scalar is
being passed as the insert/emplace argument. Converting from one scalar
type to another won't have surprising value-altering behaviour, and has
no side effects (unlike e.g. constructing a std::string from a const
char* argument, which might allocate).
We don't need to do this for std::multimap, because we always insert the
new node even if the key is already present. So there's no benefit to
doing the lookup before allocating the new node.
libstdc++-v3/ChangeLog:
PR libstdc++/92300
* include/bits/stl_map.h (insert(Pair&&), emplace(Args&&...)):
Check whether the arguments can be looked up directly without
constructing a temporary node first.
* include/bits/stl_pair.h (__is_pair): Move to here, from ...
* include/bits/uses_allocator_args.h (__is_pair): ... here.
* testsuite/23_containers/map/modifiers/emplace/92300.cc: New test.
* testsuite/23_containers/map/modifiers/insert/92300.cc: New test.
The possible base classes of std::allocator are new_allocator and
malloc_allocator, which both cause a non-reserved name to be declared in
every program that includes the definition of std::allocator. This is
non-conforming.
This change replaces __gnu_cxx::new_allocator with std::__new_allocator
which is identical except for using a reserved name. The non-standard
extension __gnu_cxx::new_allocator is preserved as a thin wrapper over
std::__new_allocator. There is no problem with the extension using a
non-reserved name now that it's not included by default in other
headers.
The same change could be done to __gnu_cxx::malloc_allocator but as it's
not the default configuration it can wait.
libstdc++-v3/ChangeLog:
PR libstdc++/64135
* config/allocator/new_allocator_base.h: Include
<bits/new_allocator.h> instead of <ext/new_allocator.h>.
(__allocator_base): Use std::__new_allocator instead of
__gnu_cxx::new_allocator.
* doc/xml/manual/allocator.xml: Document new default base class
for std::allocator.
* doc/xml/manual/evolution.xml: Likewise.
* doc/html/*: Regenerate.
* include/Makefile.am: Add bits/new_allocator.h.
* include/Makefile.in: Regenerate.
* include/experimental/memory_resource (new_delete_resource):
Use std::__new_allocator instead of __gnu_cxx::new_allocator.
* include/ext/new_allocator.h (new_allocator): Derive from
std::__new_allocator. Move implementation to ...
* include/bits/new_allocator.h: New file.
* testsuite/20_util/allocator/64135.cc: New test.
If the allocator-extended move constructor move-constructs each element
into the new container, the contents of the old container are left in
moved-from states. We cannot know if those states preserve the
container's ordering and uniqueness guarantees, so just erase all
moved-from elements.
libstdc++-v3/ChangeLog:
PR libstdc++/103501
* include/bits/stl_tree.h (_Rb_tree(_Rb_tree&&, false_type)):
Clear container if elements have been moved-from.
* testsuite/23_containers/map/allocator/move_cons.cc: Expect
moved-from container to be empty.
* testsuite/23_containers/multimap/allocator/move_cons.cc:
Likewise.
* testsuite/23_containers/multiset/allocator/103501.cc: New test.
* testsuite/23_containers/set/allocator/103501.cc: New test.
This adds std::__is_constant_evaluated() as a C++11 wrapper for
__builtin_is_constant_evaluated, but just returning false if the
built-in isn't supported by the compiler. This allows us to use it
throughout the library without checking __has_builtin every time.
Some uses in std::vector and std::string can only be constexpr when the
std::is_constant_evaluated() function actually works, so we might as
well guard them with a relevant macro and call that function directly,
rather than the built-in or std::__is_constant_evaluated().
The remaining checks of the __cpp_lib_is_constant_evaluated macro could
now be replaced by checking __cplusplus >= 202002 instead, but there's
no practical difference. We still need some kind of preprocessor check
there anyway.
libstdc++-v3/ChangeLog:
* doc/doxygen/user.cfg.in (PREDEFINED): Change macro name.
* include/bits/allocator.h (allocate, deallocate): Use
std::__is_constant_evaluated() unconditionally, instead of
checking whether std::is_constant_evaluated() (or the built-in)
can be used.
* include/bits/basic_string.h: Check new macro. call
std::is_constant_evaluated() directly in C++20-only code that is
guarded by a suitable macro.
* include/bits/basic_string.tcc: Likewise.
* include/bits/c++config (__is_constant_evaluated): Define.
(_GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED): Replace with ...
(_GLIBCXX_HAVE_IS_CONSTANT_EVALUATED): New macro.
* include/bits/char_traits.h (char_traits): Replace conditional
calls to std::is_constant_evaluated with unconditional calls to
std::__is_constant_evaluated.
* include/bits/cow_string.h: Use new macro.
* include/bits/ranges_algobase.h (__copy_or_move): Replace
conditional calls to std::is_constant_evaluated with unconditional
calls to std::__is_constant_evaluated.
(__copy_or_move_backward, __fill_n_fn): Likewise.
* include/bits/ranges_cmp.h (ranges::less): Likewise.
* include/bits/stl_algobase.h (lexicographical_compare_three_way):
Likewise.
* include/bits/stl_bvector.h: Call std::is_constant_evaluated
directly in C++20-only code that is guarded by a suitable macro.
* include/bits/stl_construct.h (_Construct, _Destroy, _Destroy_n):
Replace is_constant_evaluated with __is_constant_evaluated.
* include/bits/stl_function.h (greater, less, greater_equal)
(less_equal): Replace __builtin_is_constant_evaluated and
__builtin_constant_p with __is_constant_evaluated.
* include/bits/stl_vector.h: Call std::is_constant_evaluated()
in C++20-only code.
* include/debug/helper_functions.h (__check_singular): Use
__is_constant_evaluated instead of built-in, or remove check
entirely.
* include/std/array (operator<=>): Use __is_constant_evaluated
unconditionally.
* include/std/bit (__bit_ceil): Likewise.
* include/std/type_traits (is_constant_evaluated): Define using
'if consteval' if possible.
* include/std/version: Use new macro.
* libsupc++/compare: Use __is_constant_evaluated instead of
__builtin_is_constant_evaluated.
* testsuite/23_containers/array/tuple_interface/get_neg.cc:
Adjust dg-error lines.
Fix some tests that assume that a moved-from string is empty, or that
default constructing a string doesn't allocate.
libstdc++-v3/ChangeLog:
* testsuite/21_strings/basic_string/cons/char/moveable.cc: Allow
moved-from string to be non-empty.
* testsuite/21_strings/basic_string/cons/char/moveable2.cc:
Likewise.
* testsuite/21_strings/basic_string/cons/char/moveable2_c++17.cc:
Likewise.
* testsuite/21_strings/basic_string/cons/wchar_t/moveable.cc:
Likewise.
* testsuite/21_strings/basic_string/cons/wchar_t/moveable2.cc:
Likewise.
* testsuite/21_strings/basic_string/cons/wchar_t/moveable2_c++17.cc:
Likewise.
* testsuite/21_strings/basic_string/modifiers/assign/char/87749.cc:
Construct empty string before setting oom flag.
* testsuite/21_strings/basic_string/modifiers/assign/wchar_t/87749.cc:
Likewise.
My last change to the fully-dynamic-string actually broke it. This fixes
the move constructor so it builds, and simplifies it slightly so that
more code is common between the fully-dynamic enabled/disabled cases.
libstdc++-v3/ChangeLog:
* include/bits/cow_string.h (basic_string(basic_string&&)): Fix
mem-initializer for _GLIBCXX_FULLY_DYNAMIC_STRING==0 case.
* testsuite/21_strings/basic_string/cons/char/noexcept_move_construct.cc:
Remove outdated comment.
* testsuite/21_strings/basic_string/cons/wchar_t/noexcept_move_construct.cc:
Likewise.
This patch attempts to implement P1272R4 (except for the std::bit_cast
changes in there which seem quite unrelated to this and will need to be
fixed on the compiler side).
While at least for GCC __builtin_bswap{16,32,64,128} should work fine
in constant expressions, I wonder about other compilers, so I'm using
a fallback implementation for constexpr evaluation always.
If you think that is unnecessary, I can drop the
__cpp_if_consteval >= 202106L &&
if !consteval
{
and
}
and reformat.
The fallback implementation is an attempt to make it work even for integral
types that don't have number of bytes divisible by 2 or when __CHAR_BIT__
is e.g. 16.
2021-11-28 Jakub Jelinek <jakub@redhat.com>
* include/std/bit (__cpp_lib_byteswap, byteswap): Define.
* include/std/version (__cpp_lib_byteswap): Define.
* testsuite/26_numerics/bit/bit.byteswap/byteswap.cc: New test.
* testsuite/26_numerics/bit/bit.byteswap/version.cc: New test.
This test was written to verify that the LWG 3265 changes work. But
those changes were superseded by LWG 3435, and the test is now incorrect
according to the current draft. The assignment operator is now
constrained to also require convertibility, which makes the test fail.
Change the Iter type to be convertible from int*, but make it throw an
exception if that conversion is used. Change the test from compile-only
to run, so we verify that the exception isn't thrown.
libstdc++-v3/ChangeLog:
* testsuite/24_iterators/move_iterator/dr3265.cc: Fix test to
account for LWG 3435 resolution.
An 'xfail' selector means the test is expected to fail at runtime, so is
ignored for a compile-only test. The way to mark a compile-only test as
failing is with dg-error (which these already do).
libstdc++-v3/ChangeLog:
* testsuite/21_strings/basic_string_view/element_access/char/back_constexpr_neg.cc:
Remove xfail selector.
* testsuite/21_strings/basic_string_view/element_access/char/constexpr_neg.cc:
Likewise.
Likewise.
* testsuite/21_strings/basic_string_view/element_access/char/front_constexpr_neg.cc:
Likewise.
* testsuite/21_strings/basic_string_view/element_access/wchar_t/back_constexpr_neg.cc:
Likewise.
* testsuite/21_strings/basic_string_view/element_access/wchar_t/constexpr_neg.cc:
Likewise.
* testsuite/21_strings/basic_string_view/element_access/wchar_t/front_constexpr_neg.cc:
Likewise.
* testsuite/23_containers/span/101411.cc: Likewise.
* testsuite/25_algorithms/copy/debug/constexpr_neg.cc: Likewise.
* testsuite/25_algorithms/copy_backward/debug/constexpr_neg.cc:
Likewise.
* testsuite/25_algorithms/equal/constexpr_neg.cc: Likewise.
* testsuite/25_algorithms/equal/debug/constexpr_neg.cc: Likewise.
* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_neg.cc:
Likewise.
* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_pred_neg.cc:
Likewise.
* testsuite/25_algorithms/lower_bound/debug/constexpr_valid_range_neg.cc:
Likewise.
* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_neg.cc:
Likewise.
* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_pred_neg.cc:
Likewise.
* testsuite/25_algorithms/upper_bound/debug/constexpr_valid_range_neg.cc:
Likewise.
Some of the checks in 20_util/pointer_traits/lwg3545.cc really belong in
20_util/to_address/lwg3545 instead.
This also fixes the ordering of the dg-options and dg-do directives.
libstdc++-v3/ChangeLog:
* testsuite/20_util/pointer_traits/lwg3545.cc: Move to_address
tests to ...
* testsuite/20_util/to_address/lwg3545.cc: ... here. Add -std
option before checking effective target.
There was a c++11_only dg-error in this testcase, for a "body of
constexpr function is not a return statement" diagnostic that was bogus,
but happened because the return statement was ill-formed. A change to
G++ earlier this month means that diagnostic is no longer emitted, so
remove the dg-error.
libstdc++-v3/ChangeLog:
* testsuite/20_util/tuple/comparison_operators/overloaded2.cc:
Remove dg-error for C++11_only error.
This implements the resolution I'm proposing for LWG 3545, to avoid hard
errors when using std::to_address for types that make pointer_traits
ill-formed.
Consistent with std::iterator_traits, instantiating std::pointer_traits
for a non-pointer type will be well-formed, but give an empty type with
no member types. This avoids the problematic cases for std::to_address.
Additionally, the pointer_to member is now only declared when the
element type is not cv void (and for C++20, when the function body would
be well-formed). The rebind member was already SFINAE-friendly in our
implementation.
libstdc++-v3/ChangeLog:
PR libstdc++/96416
* include/bits/ptr_traits.h (pointer_traits): Reimplement to be
SFINAE-friendly (LWG 3545).
* testsuite/20_util/pointer_traits/lwg3545.cc: New test.
* testsuite/20_util/to_address/1_neg.cc: Adjust dg-error line.
* testsuite/20_util/to_address/lwg3545.cc: New test.
libstdc++-v3/ChangeLog:
PR libstdc++/101608
* include/bits/ranges_algobase.h (__fill_n_fn): Check for
constant evaluation before using memset.
* testsuite/25_algorithms/fill_n/constrained.cc: Check
byte-sized values as well.
The type printers are not substituting std::string for
std::basic_string<char> in debug mode, mark some tests as xfail.
libstdc++-v3/ChangeLog:
* testsuite/libstdc++-prettyprinters/80276.cc: Add xfail for
debug mode.
* testsuite/libstdc++-prettyprinters/libfundts.cc: Likewise.
An effective target like foo-bar-baz will match a target selector of
*-*-* and cause problems in the testsuite. Several libstdc++ et keywords
are of the form foo-bar, which could still be a problem for *-*
selectors.
Replace hyphens with underscores in the et keywords "debug-mode",
"cxx11-abi", etc.
libstdc++-v3/ChangeLog:
* testsuite/lib/libstdc++.exp: Rename effective target keywords
to avoid dashes in the name.
* testsuite/*: Update effective targe keywords.
This allows tests to be skipped if the std::allocator implementation is
not __gnu_cxx::new_allocator.
The 20_util/allocator/overaligned.cc test requires either C++17 or
new_allocator, otherwise we can't guarantee to return overaligned
memory.
libstdc++-v3/ChangeLog:
* testsuite/18_support/50594.cc: Check effective target.
* testsuite/20_util/allocator/1.cc: Likewise.
* testsuite/20_util/allocator/overaligned.cc: Likewise.
* testsuite/23_containers/unordered_map/96088.cc: Likewise.
* testsuite/23_containers/unordered_multimap/96088.cc: Likewise.
* testsuite/23_containers/unordered_multiset/96088.cc: Likewise.
* testsuite/23_containers/unordered_set/96088.cc: Likewise.
* testsuite/ext/throw_allocator/check_delete.cc: Likewise.
* testsuite/ext/throw_allocator/check_new.cc: Likewise.
* testsuite/lib/libstdc++.exp (check_effective_target_std_allocator_new):
Define new proc.
Depending on the permutation of CPU, OS version and shared/non-
shared library inclusion, we get can get warnings from the external
tools (ld64, dsymutil) which are not actually libstdc++ issues but
relate to the external tools themselves. This is already pruned
in the main testsuite, this adds it to the library.
Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>
libstdc++-v3/ChangeLog:
* testsuite/lib/prune.exp: Prune dsymutil (ld64) warning.
Clang gives errors for constexpr std::string because the memory returned
by std::allocator<T>::allocate does not contain any objects yet, and
attempting to set them using char_traits::assign or char_traits::copy
fails with:
assignment to object outside its lifetime is not allowed in a constant expression
*__result = *__first;
^
This adds code to std::char_traits to use std::construct_at to begin
lifetimes when called during constant evaluation. To support
specializations of std::basic_string that don't use std::char_traits
there is now another layer of wrapper around the allocator_traits, so
that the lifetime of characters is begun as soon as the memory is
allocated. By doing it in the char traits and allocator traits, the rest
of basic_string can ignore the problem.
While modifying char_traits::copy and char_traits::assign to begin
lifetimes for the constexpr cases, I also replaced their uses of
std::copy and std::fill_n respectively. That means we don't need
<bits/stl_algobase.h> for char_traits.
libstdc++-v3/ChangeLog:
PR libstdc++/103295
* include/bits/basic_string.h (_Alloc_traits): Replace typedef
with struct for C++20 mode.
* include/bits/basic_string.tcc (_M_replace): Use _Alloc_traits
for allocation.
* include/bits/char_traits.h (__gnu_cxx::char_traits::assign):
Use std::_Construct during constant evaluation.
(__gnu_cxx::char_traits::assign(CharT*, const CharT*, size_t)):
Likewise. Replace std::fill_n with memset or manual loop.
(__gnu_cxx::char_traits::copy): Likewise, replacing std::copy
with memcpy.
* include/ext/vstring.h: Include <bits/stl_algobase.h> for
std::min.
* include/std/string_view: Likewise.
* testsuite/21_strings/basic_string/capacity/char/resize_and_overwrite.cc:
Add constexpr test.
The constexpr branch in __gnu_cxx::char_traits::move compares the string
arguments to see if they overlap, but relational comparisons between
unrelated pointers are not core constant expressions.
I want to replace the comparisons with a loop using pointer equality to
determine whether the end of the source string is in the destination
string. However, that doesn't work with GCC, due to PR c++/89074 so
allocate a temporary buffer instead and copy out into that first, so
that overlapping source and destination don't matter. The allocation
isn't supported by the current Intel icc so use the loop as a fallback.
libstdc++-v3/ChangeLog:
* include/bits/char_traits.h (__gnu_cxx::char_traits::move):
Do not compare unrelated pointers during constant evaluation.
* testsuite/21_strings/char_traits/requirements/constexpr_functions_c++20.cc:
Improve tests for char_traits::move.
The r179236 fix for std::type_info::operator== should also have been
applied to std::type_info::before. Otherwise two distinct types can
compare equivalent due to using a string comparison, when they should do
a pointer comparison.
libstdc++-v3/ChangeLog:
PR libstdc++/103240
* libsupc++/tinfo2.cc (type_info::before): Use unadjusted name
to check for the '*' prefix.
* testsuite/util/testsuite_shared.cc: Add type_info object for
use in new test.
* testsuite/18_support/type_info/103240.cc: New test.
Some tests fail when run with -D_GLIBCXX_USE_CXX11_ABI or -stdgnu++20.
libstdc++-v3/ChangeLog:
* include/bits/basic_string.h (operator<=>): Use constexpr
unconditionally.
* testsuite/21_strings/basic_string/modifiers/constexpr.cc:
Require cxx11-abit effective target.
* testsuite/21_strings/headers/string/synopsis.cc: Add
conditional constexpr to declarations, and adjust relational
operators for C++20.
This is only supported for the cxx11 ABI, not for COW strings.
libstdc++-v3/ChangeLog:
* include/bits/basic_string.h (basic_string, operator""s): Add
constexpr for C++20.
(basic_string::basic_string(basic_string&&)): Only copy
initialized portion of the buffer.
(basic_string::basic_string(basic_string&&, const Alloc&)):
Likewise.
* include/bits/basic_string.tcc (basic_string): Add constexpr
for C++20.
(basic_string::swap(basic_string&)): Only copy initialized
portions of the buffers.
(basic_string::_M_replace): Add constexpr implementation that
doesn't depend on pointer comparisons.
* include/bits/cow_string.h: Adjust comment.
* include/ext/type_traits.h (__is_null_pointer): Add constexpr.
* include/std/string (erase, erase_if): Add constexpr.
* include/std/version (__cpp_lib_constexpr_string): Update
value.
* testsuite/21_strings/basic_string/cons/char/constexpr.cc:
New test.
* testsuite/21_strings/basic_string/cons/wchar_t/constexpr.cc:
New test.
* testsuite/21_strings/basic_string/literals/constexpr.cc:
New test.
* testsuite/21_strings/basic_string/modifiers/constexpr.cc: New test.
* testsuite/21_strings/basic_string/modifiers/swap/char/constexpr.cc:
New test.
* testsuite/21_strings/basic_string/modifiers/swap/wchar_t/constexpr.cc:
New test.
* testsuite/21_strings/basic_string/version.cc: New test.
I fixed some undefined behaviour in string tests in r238609, but I only
fixed the narrow char versions. This applies the same fixes to the
wchar_t ones. These problems were found when testing a patch to make
std::basic_string usable in constexpr.
libstdc++-v3/ChangeLog:
* testsuite/21_strings/basic_string/modifiers/append/wchar_t/1.cc:
Fix reads past the end of strings.
* testsuite/21_strings/basic_string/operations/compare/wchar_t/1.cc:
Likewise.
* testsuite/experimental/string_view/operations/compare/wchar_t/1.cc:
Likewise.
With each successive C++ standard the restrictions on the use of the
constexpr keyword for functions get weaker and weaker; it recently occurred
to me that it is heading toward the same fate as the C register keyword,
which was once useful for optimization but became obsolete. Similarly, it
seems to me that we should be able to just treat inlines as constexpr
functions and not make people add the extra keyword everywhere.
There were a lot of testcase changes needed; many disabling errors about
non-constexpr functions that are now constexpr, and many disabling implicit
constexpr so that the tests can check the same thing as before, whether
that's mangling or whatever.
gcc/c-family/ChangeLog:
* c.opt: Add -fimplicit-constexpr.
* c-cppbuiltin.c: Define __cpp_implicit_constexpr.
* c-opts.c (c_common_post_options): Disable below C++14.
gcc/cp/ChangeLog:
* cp-tree.h (struct lang_decl_fn): Add implicit_constexpr.
(decl_implicit_constexpr_p): New.
* class.c (type_maybe_constexpr_destructor): Use
TYPE_HAS_TRIVIAL_DESTRUCTOR and maybe_constexpr_fn.
(finalize_literal_type_property): Simplify.
* constexpr.c (is_valid_constexpr_fn): Check for dtor.
(maybe_save_constexpr_fundef): Try to set DECL_DECLARED_CONSTEXPR_P
on inlines.
(cxx_eval_call_expression): Use maybe_constexpr_fn.
(maybe_constexpr_fn): Handle flag_implicit_constexpr.
(var_in_maybe_constexpr_fn): Use maybe_constexpr_fn.
(potential_constant_expression_1): Likewise.
(decl_implicit_constexpr_p): New.
* decl.c (validate_constexpr_redeclaration): Allow change with
-fimplicit-constexpr.
(grok_special_member_properties): Use maybe_constexpr_fn.
* error.c (dump_function_decl): Don't print 'constexpr'
if it's implicit.
* Make-lang.in (check-c++-all): Update.
libstdc++-v3/ChangeLog:
* testsuite/20_util/to_address/1_neg.cc: Adjust error.
* testsuite/26_numerics/random/concept.cc: Adjust asserts.
gcc/testsuite/ChangeLog:
* lib/g++-dg.exp: Handle "impcx".
* lib/target-supports.exp
(check_effective_target_implicit_constexpr): New.
* g++.dg/abi/abi-tag16.C:
* g++.dg/abi/abi-tag18a.C:
* g++.dg/abi/guard4.C:
* g++.dg/abi/lambda-defarg1.C:
* g++.dg/abi/mangle26.C:
* g++.dg/cpp0x/constexpr-diag3.C:
* g++.dg/cpp0x/constexpr-ex1.C:
* g++.dg/cpp0x/constexpr-ice5.C:
* g++.dg/cpp0x/constexpr-incomplete2.C:
* g++.dg/cpp0x/constexpr-memfn1.C:
* g++.dg/cpp0x/constexpr-neg3.C:
* g++.dg/cpp0x/constexpr-specialization.C:
* g++.dg/cpp0x/inh-ctor19.C:
* g++.dg/cpp0x/inh-ctor30.C:
* g++.dg/cpp0x/lambda/lambda-mangle3.C:
* g++.dg/cpp0x/lambda/lambda-mangle5.C:
* g++.dg/cpp1y/auto-fn12.C:
* g++.dg/cpp1y/constexpr-loop5.C:
* g++.dg/cpp1z/constexpr-lambda7.C:
* g++.dg/cpp2a/constexpr-dtor3.C:
* g++.dg/cpp2a/constexpr-new13.C:
* g++.dg/cpp2a/constinit11.C:
* g++.dg/cpp2a/constinit12.C:
* g++.dg/cpp2a/constinit14.C:
* g++.dg/cpp2a/constinit15.C:
* g++.dg/cpp2a/spaceship-constexpr1.C:
* g++.dg/cpp2a/spaceship-eq3.C:
* g++.dg/cpp2a/udlit-class-nttp-neg2.C:
* g++.dg/debug/dwarf2/auto1.C:
* g++.dg/debug/dwarf2/cdtor-1.C:
* g++.dg/debug/dwarf2/lambda1.C:
* g++.dg/debug/dwarf2/pr54508.C:
* g++.dg/debug/dwarf2/pubnames-2.C:
* g++.dg/debug/dwarf2/pubnames-3.C:
* g++.dg/ext/is_literal_type3.C:
* g++.dg/ext/visibility/template7.C:
* g++.dg/gcov/gcov-12.C:
* g++.dg/gcov/gcov-2.C:
* g++.dg/ipa/devirt-35.C:
* g++.dg/ipa/devirt-36.C:
* g++.dg/ipa/devirt-37.C:
* g++.dg/ipa/devirt-44.C:
* g++.dg/ipa/imm-devirt-1.C:
* g++.dg/lookup/builtin5.C:
* g++.dg/lto/inline-crossmodule-1_0.C:
* g++.dg/modules/enum-1_a.C:
* g++.dg/modules/fn-inline-1_c.C:
* g++.dg/modules/pmf-1_b.C:
* g++.dg/modules/used-1_c.C:
* g++.dg/tls/thread_local11.C:
* g++.dg/tls/thread_local11a.C:
* g++.dg/tm/pr46653.C:
* g++.dg/ubsan/pr70035.C:
* g++.old-deja/g++.other/delete6.C:
* g++.dg/modules/pmf-1_a.H:
Adjust for implicit constexpr.
When merging 2 unordered containers with same hasher we can re-use the hash code from
the cache if any.
Also in the context of the merge operation on multi-container use previous insert iterator as a hint
for the next insert.
libstdc++-v3/ChangeLog:
* include/bits/hashtable_policy.h:
(_Hash_code_base<>::_M_hash_code(const _Hash&, const _Hash_node_value<_Value, true>&)): New.
(_Hash_code_base<>::_M_hash_code<_H2>(const _H2&, const _Hash_node_value<>&)): New.
* include/bits/hashtable.h (_Hashtable<>::_M_merge_unique): Use latter.
(_Hashtable<>::_M_merge_multi): Likewise.
* testsuite/23_containers/unordered_multiset/modifiers/merge.cc (test05): New test.
* testsuite/23_containers/unordered_set/modifiers/merge.cc (test04): New test.
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.
This implements P1004R2 ("Making std::vector constexpr") for C++20.
For now, debug mode vectors are not supported in constant expressions.
To make that work we might need to disable all attaching/detaching of
safe iterators. That can be fixed later.
Co-authored-by: Josh Marshall <joshua.r.marshall.1991@gmail.com>
libstdc++-v3/ChangeLog:
* include/bits/alloc_traits.h (_Destroy): Make constexpr for
C++20 mode.
* include/bits/allocator.h (__shrink_to_fit::_S_do_it):
Likewise.
* include/bits/stl_algobase.h (__fill_a1): Declare _Bit_iterator
overload constexpr for C++20.
* include/bits/stl_bvector.h (_Bit_type, _S_word_bit): Move out
of inline namespace.
(_Bit_reference, _Bit_iterator_base, _Bit_iterator)
(_Bit_const_iterator, _Bvector_impl_data, _Bvector_base)
(vector<bool, A>>): Add constexpr to every member function.
(_Bvector_base::_M_allocate): Initialize storage during constant
evaluation.
(vector<bool, A>::_M_initialize_value): Use __fill_bvector_n
instead of memset.
(__fill_bvector_n): New helper function to replace memset during
constant evaluation.
* include/bits/stl_uninitialized.h (__uninitialized_copy<false>):
Move logic to ...
(__do_uninit_copy): New function.
(__uninitialized_fill<false>): Move logic to ...
(__do_uninit_fill): New function.
(__uninitialized_fill_n<false>): Move logic to ...
(__do_uninit_fill_n): New function.
(__uninitialized_copy_a): Add constexpr. Use __do_uninit_copy.
(__uninitialized_move_a, __uninitialized_move_if_noexcept_a):
Add constexpr.
(__uninitialized_fill_a): Add constexpr. Use __do_uninit_fill.
(__uninitialized_fill_n_a): Add constexpr. Use
__do_uninit_fill_n.
(__uninitialized_default_n, __uninitialized_default_n_a)
(__relocate_a_1, __relocate_a): Add constexpr.
* include/bits/stl_vector.h (_Vector_impl_data, _Vector_impl)
(_Vector_base, vector): Add constexpr to every member function.
(_Vector_impl::_S_adjust): Disable ASan annotation during
constant evaluation.
(_Vector_base::_S_use_relocate): Disable bitwise-relocation
during constant evaluation.
(vector::_Temporary_value): Use a union for storage.
* include/bits/vector.tcc (vector, vector<bool>): Add constexpr
to every member function.
* include/std/vector (erase_if, erase): Add constexpr.
* testsuite/23_containers/headers/vector/synopsis.cc: Add
constexpr for C++20 mode.
* testsuite/23_containers/vector/bool/cmp_c++20.cc: Change to
compile-only test using constant expressions.
* testsuite/23_containers/vector/bool/capacity/29134.cc: Adjust
namespace for _S_word_bit.
* testsuite/23_containers/vector/bool/modifiers/insert/31370.cc:
Likewise.
* testsuite/23_containers/vector/cmp_c++20.cc: Likewise.
* testsuite/23_containers/vector/cons/89164.cc: Adjust errors
for C++20 and move C++17 test to ...
* testsuite/23_containers/vector/cons/89164_c++17.cc: ... here.
* testsuite/23_containers/vector/bool/capacity/constexpr.cc: New test.
* testsuite/23_containers/vector/bool/cons/constexpr.cc: New test.
* testsuite/23_containers/vector/bool/element_access/constexpr.cc: New test.
* testsuite/23_containers/vector/bool/modifiers/assign/constexpr.cc: New test.
* testsuite/23_containers/vector/bool/modifiers/constexpr.cc: New test.
* testsuite/23_containers/vector/bool/modifiers/swap/constexpr.cc: New test.
* testsuite/23_containers/vector/capacity/constexpr.cc: New test.
* testsuite/23_containers/vector/cons/constexpr.cc: New test.
* testsuite/23_containers/vector/data_access/constexpr.cc: New test.
* testsuite/23_containers/vector/element_access/constexpr.cc: New test.
* testsuite/23_containers/vector/modifiers/assign/constexpr.cc: New test.
* testsuite/23_containers/vector/modifiers/constexpr.cc: New test.
* testsuite/23_containers/vector/modifiers/swap/constexpr.cc: New test.
The <cxxx> headers for the C library are not under our control, so we
can't prevent them from including <unistd.h>. Change the PR 49745 test
to only include the C++ library headers, not the <cxxx> ones.
To ensure <bits/stdc++.h> isn't included automatically we need to use
no_pch to disable PCH.
libstdc++-v3/ChangeLog:
PR libstdc++/100117
* testsuite/17_intro/headers/c++1998/49745.cc: Explicitly list
all C++ headers instead of including <bits/stdc++.h>
This adds additional "getentropy" and "arc4random" tokens to
std::random_device. The former is supported on Glibc and OpenBSD (and
apparently wasm), and the latter is supported on various BSDs.
libstdc++-v3/ChangeLog:
* acinclude.m4 (GLIBCXX_CHECK_GETENTROPY, GLIBCXX_CHECK_ARC4RANDOM):
Define.
* configure.ac (GLIBCXX_CHECK_GETENTROPY, GLIBCXX_CHECK_ARC4RANDOM):
Use them.
* config.h.in: Regenerate.
* configure: Regenerate.
* src/c++11/random.cc (random_device): Add getentropy and
arc4random as sources.
* testsuite/26_numerics/random/random_device/cons/token.cc:
Check new tokens.
* testsuite/26_numerics/random/random_device/entropy.cc:
Likewise.
It's possible that independent reads from /dev/random and /dev/urandom
could produce the same value by chance. Retry if that happens. The
chances of it happening twice are miniscule.
libstdc++-v3/ChangeLog:
* testsuite/26_numerics/random/random_device/cons/token.cc:
Retry if random devices produce the same value.
The ISA-3.0 instruction set includes DARN ("deliver a random number")
which can be used similarly to the existing support for RDRAND and RDSEED.
libstdc++-v3/ChangeLog:
* src/c++11/random.cc [__powerpc__] (USE_DARN): Define.
(__ppc_darn): New function to use POWER9 DARN instruction.
(Which): Add 'darn' enumerator.
(which_source): Check for __ppc_darn.
(random_device::_M_init): Support "darn" and "hw" tokens.
(random_device::_M_getentropy): Add darn to switch.
* testsuite/26_numerics/random/random_device/cons/token.cc:
Check "darn" token.
* testsuite/26_numerics/random/random_device/entropy.cc:
Likewise.
For some reason the type printer for std::string doesn't work in C++20
mode, so std::basic_string<char, char_traits<char>, allocator<char> is
printed out in full rather than being shown as std::string. It's
probably related to the fact that the extern template declarations are
disabled for C++20, but I don't know why that affects GDB.
For now I'm just marking the relevant tests as XFAIL. That requires
adding support for target selectors to individual GDB directives such as
note-test and whatis-regexp-test.
libstdc++-v3/ChangeLog:
* testsuite/lib/gdb-test.exp: Add target selector support to the
dg-final directives.
* testsuite/libstdc++-prettyprinters/80276.cc: Add xfail for
C++20.
* testsuite/libstdc++-prettyprinters/libfundts.cc: Likewise.
* testsuite/libstdc++-prettyprinters/prettyprinters.exp: Tweak
comment.
These functions have been deprecated since C++11, and were removed in
C++17. The proposal P0323 wants to reuse the name std::unexpected for a
class template, so we will need to stop defining the current function
for C++23 anyway.
This marks them as deprecated for C++11 and up, to warn users they won't
continue to be available. It disables them for C++17 and up, unless the
_GLIBCXX_USE_DEPRECATED macro is defined.
The <unwind-cxx.h> header uses std::unexpected_handler in the public
API, but since that type is the same as std::terminate_handler we can
just use that instead, to avoid warnings about it being deprecated.
libstdc++-v3/ChangeLog:
* doc/xml/manual/evolution.xml: Document deprecations.
* doc/html/*: Regenerate.
* libsupc++/exception (unexpected_handler, unexpected)
(get_unexpected, set_unexpected): Add deprecated attribute.
Do not define without _GLIBCXX_USE_DEPRECATED for C++17 and up.
* libsupc++/eh_personality.cc (PERSONALITY_FUNCTION): Disable
deprecated warnings.
* libsupc++/eh_ptr.cc (std::rethrow_exception): Likewise.
* libsupc++/eh_terminate.cc: Likewise.
* libsupc++/eh_throw.cc (__cxa_init_primary_exception):
Likewise.
* libsupc++/unwind-cxx.h (struct __cxa_exception): Use
terminate_handler instead of unexpected_handler.
(struct __cxa_dependent_exception): Likewise.
(__unexpected): Likewise.
* testsuite/18_support/headers/exception/synopsis.cc: Add
dg-warning for deprecated warning.
* testsuite/18_support/exception_ptr/60612-unexpected.cc:
Disable deprecated warnings.
* testsuite/18_support/set_unexpected.cc: Likewise.
* testsuite/18_support/unexpected_handler.cc: Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/lambda/lambda-eh2.C: Add dg-warning for new
deprecation warnings.
* g++.dg/cpp0x/noexcept06.C: Likewise.
* g++.dg/cpp0x/noexcept07.C: Likewise.
* g++.dg/eh/forced3.C: Likewise.
* g++.dg/eh/unexpected1.C: Likewise.
* g++.old-deja/g++.eh/spec1.C: Likewise.
* g++.old-deja/g++.eh/spec2.C: Likewise.
* g++.old-deja/g++.eh/spec3.C: Likewise.
* g++.old-deja/g++.eh/spec4.C: Likewise.
* g++.old-deja/g++.mike/eh33.C: Likewise.
* g++.old-deja/g++.mike/eh34.C: Likewise.
* g++.old-deja/g++.mike/eh50.C: Likewise.
* g++.old-deja/g++.mike/eh51.C: Likewise.
This reduces the number of class template instantiations needed for code
using tuples, by reusing _Nth_type in tuple_element and specializing
tuple_size_v for tuple, pair and array (and const-qualified versions of
them).
Also define the _Nth_type primary template as a complete type (but with
no nested 'type' member). This avoids "invalid use of incomplete type"
errors for out-of-range specializations of tuple_element. Those errors
would probably be confusing and unhelpful for users. We already have
a user-friendly static assert in tuple_element itself.
Also ensure that tuple_size_v is available whenever tuple_size is (as
proposed by LWG 3387). We already do that for tuple_element_t.
libstdc++-v3/ChangeLog:
* include/bits/stl_pair.h (tuple_size_v): Define partial
specializations for std::pair.
* include/bits/utility.h (_Nth_type): Move definition here
and define primary template.
(tuple_size_v): Move definition here.
* include/std/array (tuple_size_v): Define partial
specializations for std::array.
* include/std/tuple (tuple_size_v): Move primary template to
<bits/utility.h>. Define partial specializations for
std::tuple.
(tuple_element): Change definition to use _Nth_type.
* include/std/variant (_Nth_type): Move to <bits/utility.h>.
(variant_alternative, variant): Adjust qualification of
_Nth_type.
* testsuite/20_util/tuple/element_access/get_neg.cc: Prune
additional errors from _Nth_type.
Prior to r12-4447 (implementing P2231R1 constexpr changes) we didn't
construct the correct member of the union in __variant_construct_single,
we just plopped an object in the memory occupied by the union:
void* __storage = std::addressof(__lhs._M_u);
using _Type = remove_reference_t<decltype(__rhs_mem)>;
::new (__storage) _Type(std::forward<decltype(__rhs_mem)>(__rhs_mem));
We didn't care whether we had variant<int, const int>, we would just
place an int (or const int) into the storage, and then set the _M_index
to say which one it was.
In the new constexpr-friendly code we use std::construct_at to construct
the union object, which constructs the active member of the right type.
But now we need to know exactly the right type. We have to distinguish
between alternatives of type int and const int, and we have to be able
to find a const int (or const std::string, as in the OP) among the
alternatives. So my change from remove_reference_t<decltype(__rhs_mem)>
to remove_cvref_t<_Up> was wrong. It strips the const from const int,
and then we can't find the index of the const int alternative.
But just using remove_reference_t doesn't work either. When the copy
assignment operator of std::variant<int> uses __variant_construct_single
it passes a const int& as __rhs_mem, but if we don't strip the const
then we try to find const int among the alternatives, and *that* fails.
Similarly for the copy constructor, which also uses a const int& as the
initializer for a non-const int alternative.
The root cause of the problem is that __variant_construct_single doesn't
know the index of the type it's supposed to construct, and the new
_Variant_storage::__index_of<_Type> helper doesn't work if __rhs_mem and
the alternative being constructed have different const-qualification. We
need to replace __variant_construct_single with something that knows the
index of the alternative being constructed. All uses of that function do
actually know the index, but that context is lost by the time we call
__variant_construct_single. This patch replaces that function and
__variant_construct, inlining their effects directly into the callers.
libstdc++-v3/ChangeLog:
PR libstdc++/102912
* include/std/variant (_Variant_storage::__index_of): Remove.
(__variant_construct_single): Remove.
(__variant_construct): Remove.
(_Copy_ctor_base::_Copy_ctor_base(const _Copy_ctor_base&)): Do
construction directly instead of using __variant_construct.
(_Move_ctor_base::_Move_ctor_base(_Move_ctor_base&&)): Likewise.
(_Move_ctor_base::_M_destructive_move()): Remove.
(_Move_ctor_base::_M_destructive_copy()): Remove.
(_Copy_assign_base::operator=(const _Copy_assign_base&)): Do
construction directly instead of using _M_destructive_copy.
(variant::swap): Do construction directly instead of using
_M_destructive_move.
* testsuite/20_util/variant/102912.cc: New test.
The standard does not require const-correct comparisons in list::sort.
libstdc++-v3/ChangeLog:
PR libstdc++/66742
* include/bits/list.tcc (list::sort): Use mutable iterators for
comparisons.
* include/bits/stl_list.h (_Scratch_list::_Ptr_cmp): Likewise.
* testsuite/23_containers/list/operations/66742.cc: Check
non-const comparisons.
