Commit Graph

7400 Commits

Author SHA1 Message Date
Jonathan Wakely
b59be1adba libstdc++: Simplify std::basic_regex construction and assignment
Introduce a new _M_compile function which does the common work needed by
all constructors and assignment. Call that directly to avoid multiple
levels of constructor delegation or calls to basic_regex::assign
overloads.

For assignment, there is no need to construct a std::basic_string if we
already have a contiguous sequence of the correct character type, and no
need to construct a temporary basic_regex when assigning from an
existing basic_regex.

Also define the copy and move assignment operators as defaulted, which
does the right thing without constructing a temporary and swapping it.
Copying or moving the shared_ptr member cannot fail, so they can be
noexcept. The assign(const basic_regex&) and assign(basic_regex&&)
member can then be defined in terms of copy or move assignment.

The new _M_compile function takes pointer arguments, so the caller has
to convert arbitrary iterator ranges into a contiguous sequence of
characters. With that simplification, the __compile_nfa helpers are not
needed and can be removed.

This also fixes a bug where construction from a contiguous sequence with
the wrong character type would fail to compile, rather than converting
the elements to the regex character type.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/regex.h (__detail::__is_contiguous_iter): Move
	here from <bits/regex_compiler.h>.
	(basic_regex::_M_compile): New function to compile an NFA from
	a regular expression string.
	(basic_regex::basic_regex): Use _M_compile instead of delegating
	to other constructors.
	(basic_regex::operator=(const basic_regex&)): Define as
	defaulted.
	(basic_regex::operator=(initializer_list<C>)): Use _M_compile.
	(basic_regex::assign(const basic_regex&)): Use copy assignment.
	(basic_regex::assign(basic_regex&&)): Use move assignment.
	(basic_regex::assign(const C*, flag_type)): Use _M_compile
	instead of constructing a temporary string.
	(basic_regex::assign(const C*, size_t, flag_type)): Likewise.
	(basic_regex::assign(const basic_string<C,T,A>&, flag_type)):
	Use _M_compile instead of constructing a temporary basic_regex.
	(basic_regex::assign(InputIter, InputIter, flag_type)): Avoid
	constructing a temporary string for contiguous iterators of the
	right value type.
	* include/bits/regex_compiler.h (__is_contiguous_iter): Move to
	<bits/regex.h>.
	(__enable_if_contiguous_iter, __disable_if_contiguous_iter)
	(__compile_nfa): Remove.
	* testsuite/28_regex/basic_regex/assign/exception_safety.cc: New
	test.
	* testsuite/28_regex/basic_regex/ctors/char/other.cc: New test.
2021-09-29 13:48:02 +01:00
Jonathan Wakely
2fcfc7d668 libstdc++: Fix return values for atomic wait on futex
This fixes a logic error in the futex-based timed wait.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/atomic_timed_wait.h (__platform_wait_until_impl):
	Return false for ETIMEDOUT and true otherwise.
2021-09-28 21:27:04 +01:00
Jonathan Wakely
c44c5f3d9f libstdc++: Remove obfuscating typedefs in <regex>
There is no benefit to using _SizeT instead of size_t, and IterT tells
you less about the type than const _CharT*. This removes some unhelpful
typedefs.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/regex_automaton.h (_NFA_base::_SizeT): Remove.
	* include/bits/regex_compiler.h (_Compiler::_IterT): Remove.
	* include/bits/regex_compiler.tcc: Likewise.
	* include/bits/regex_scanner.h (_Scanner::_IterT): Remove.
	* include/bits/regex_scanner.tcc: Likewise.
2021-09-28 20:38:58 +01:00
Jonathan Wakely
b5f276b8c7 libstdc++: Tweaks to <regex> to avoid warnings
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/regex_compiler.tcc: Add line break in empty while
	statement.
	* include/bits/regex_executor.tcc: Avoid unused parameter
	warning.
2021-09-28 20:38:58 +01:00
Jonathan Wakely
df0dd04b78 libstdc++: Add noexcept to functions in <regex>
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/regex.h (basic_regex, swap): Add noexcept to
	non-throwing functions.
	* include/bits/regex_automaton.h (_State_base, _State)
	(_NFA_base): Likewise.
	* include/bits/regex_compiler.h (_Compiler): Likewise.
	* include/bits/regex_error.h (regex_error::code()): Likewise.
	* include/bits/regex_scanner.h (_Scanner): Likewise.
2021-09-28 20:38:57 +01:00
Jonathan Wakely
aeaea265ce libstdc++: Define macro before it is first checked
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/atomic_wait.h (_GLIBCXX_HAVE_PLATFORM_WAIT):
	Define before first attempt to check it.
2021-09-28 20:30:59 +01:00
Jonathan Wakely
afffc96a52 libstdc++: Fix concept checks for iterators
This adds some additional checks the the C++98-style concept checks for
iterators, and removes some bogus checks for mutable iterators. Instead
of requiring that the result of dereferencing a mutable iterator is
assignable (which is a property of the value type, not required for the
iterator) check that the reference type is a non-const reference to the
value type.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/boost_concept_check.h (_ForwardIteratorConcept)
	(_BidirectionalIteratorConcept, _RandomAccessIteratorConcept):
	Check result types of iterator operations.
	(_Mutable_ForwardIteratorConcept): Check that iterator's
	reference type is a reference to its value type.
	(_Mutable_BidirectionalIteratorConcept): Do not require the
	value type to be assignable.
	(_Mutable_RandomAccessIteratorConcept): Likewise.
	* testsuite/24_iterators/operations/prev_neg.cc: Adjust dg-error
	line number.
2021-09-28 20:22:51 +01:00
Jonathan Wakely
45a8cd2569 libstdc++: Fix _OutputIteratorConcept checks in algorithms
The _OutputIteratorConcept should be checked using the correct value
category. The std::move_backward and std::copy_backward algorithms
should use _OutputIteratorConcept instead of _ConvertibleConcept.

In order to use the correct value category, the concept should use a
function that returns _ValueT instead of using an lvalue data member.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/boost_concept_check.h (_OutputIteratorConcept):
	Use a function to preserve value category of the type.
	* include/bits/stl_algobase.h (copy, move, fill_n): Use a
	reference as the second argument for _OutputIteratorConcept.
	(copy_backward, move_backward): Use _OutputIteratorConcept
	instead of _ConvertibleConcept.
2021-09-28 20:22:50 +01:00
Jonathan Wakely
82626be2d6 libstdc++: Specialize std::pointer_traits<__normal_iterator<I,C>>
This allows std::__to_address to be used with __normal_iterator in
C++11/14/17 modes. Without the partial specialization the deduced
pointer_traits::element_type is incorrect, and so the return type of
__to_address is wrong.

A similar partial specialization is probably needed for
__gnu_debug::_Safe_iterator.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/stl_iterator.h (pointer_traits): Define partial
	specialization for __normal_iterator.
	* testsuite/24_iterators/normal_iterator/to_address.cc: New test.
2021-09-28 20:22:50 +01:00
Jonathan Wakely
a11052d98d libstdc++: Improve std::forward static assert message
The previous message told you something was wrong, but not why it
happened or why it's bad. This changes it to explain that the function
is being misused.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/move.h (forward(remove_reference_t<T>&&)):
	Improve text of static_assert.
	* testsuite/20_util/forward/c_neg.cc: Adjust dg-error.
	* testsuite/20_util/forward/f_neg.cc: Likewise.
2021-09-28 17:30:05 +01:00
Jonathan Wakely
f2b7f56a15 libstdc++: Fix mismatched noexcept-specifiers in filesystem::path [PR102499]
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/102499
	* include/bits/fs_path.h (path::begin, path::end): Add noexcept
	to declarations, to match definitions.
2021-09-28 17:30:05 +01:00
Jonathan Wakely
9b11107ed7 libstdc++: Remove redundant 'inline' specifiers
These functions are constexpr, which means they are implicitly inline.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/range_access.h (cbegin, cend): Remove redundant
	'inline' specifier.
2021-09-24 15:38:44 +01:00
Jonathan Wakely
42eff613d0 libstdc++: Add 'noexcept' to path::iterator members
All path::iterator operations are non-throwing.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/fs_path.h (path::iterator): Add noexcept to all
	member functions and friend functions.
	(distance): Add noexcept.
	(advance): Add noexcept and inline.
	* include/experimental/bits/fs_path.h (path::iterator):
	Add noexcept to all member functions.
2021-09-17 20:43:34 +01:00
Jonathan Wakely
1fa2c5a695 libstdc++: Fix last std::tuple constructor missing 'constexpr' [PR102270]
Also rename the test so it actually runs.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/102270
	* include/std/tuple (_Tuple_impl): Add constexpr to constructor
	missed in previous patch.
	* testsuite/20_util/tuple/cons/102270.C: Moved to...
	* testsuite/20_util/tuple/cons/102270.cc: ...here.
	* testsuite/util/testsuite_allocator.h (SimpleAllocator): Add
	constexpr to constructor so it can be used for C++20 tests.
2021-09-17 20:43:34 +01:00
Jonathan Wakely
cbe705a2f7 libstdc++: Add noexcept to std::nullopt_t constructor
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/std/optional (nullptr_t): Make constructor noexcept.
2021-09-16 23:06:38 +01:00
Jonathan Wakely
21c760510d libstdc++: Remove non-deducible parameter for std::advance overload
This was just a copy and paste error.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/fs_path.h (advance): Remove non-deducible
	template parameter.
2021-09-16 23:06:37 +01:00
Jonathan Wakely
734b2c2eed libstdc++: Add missing 'constexpr' to std::tuple [PR102270]
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/102270
	* include/std/tuple (_Head_base, _Tuple_impl): Add
	_GLIBCXX20_CONSTEXPR to allocator-extended constructors.
	(tuple<>::swap(tuple&)): Add _GLIBCXX20_CONSTEXPR.
	* testsuite/20_util/tuple/cons/102270.C: New test.
2021-09-16 23:06:31 +01:00
Jonathan Wakely
e67917f5df libstdc++: Add missing constraint to std::span deduction guide [PR102280]
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/102280
	* include/std/span (span(Range&&)): Add constraint to deduction
	guide.
2021-09-16 22:59:47 +01:00
Jonathan Wakely
9d813ddd97 libstdc++: Add noexcept to std::to_string overloads that don't allocate
When the values is guaranteed to fit in the SSO buffer we know the
string won't allocate, so the function can be noexcept. For 32-bit
integers, we know they need no more than 9 bytes (or 10 with a minus
sign) and the SSO buffer is 15 bytes.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/basic_string.h [_GLIBCXX_USE_CXX11_ABI]
	(to_string): Add noexcept if the type width is 32 bits or less.
2021-09-16 22:59:47 +01:00
Jonathan Wakely
869107c9c9 libstdc++: Add noexcept to unique_ptr accessors
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/unique_ptr.h (__uniq_ptr_impl::_M_ptr)
	(__uniq_ptr_impl::_M_deleter): Add noexcept.
2021-09-16 22:59:46 +01:00
Jason Merrill
76b75018b3 c++: implement C++17 hardware interference size
The last missing piece of the C++17 standard library is the hardware
intereference size constants.  Much of the delay in implementing these has
been due to uncertainty about what the right values are, and even whether
there is a single constant value that is suitable; the destructive
interference size is intended to be used in structure layout, so program
ABIs will depend on it.

In principle, both of these values should be the same as the target's L1
cache line size.  When compiling for a generic target that is intended to
support a range of target CPUs with different cache line sizes, the
constructive size should probably be the minimum size, and the destructive
size the maximum, unless you are constrained by ABI compatibility with
previous code.

From discussion on gcc-patches, I've come to the conclusion that the
solution to the difficulty of choosing stable values is to give up on it,
and instead encourage only uses where ABI stability is unimportant: in
particular, uses where the ABI is shared at most between translation units
built at the same time with the same flags.

To that end, I've added a warning for any use of the constant value of
std::hardware_destructive_interference_size in a header or module export.
Appropriate uses within a project can disable the warning.

A previous iteration of this patch included an -finterference-tune flag to
make the value vary with -mtune; this iteration makes that the default
behavior, which should be appropriate for all reasonable uses of the
variable.  The previous default of "stable-ish" seems to me likely to have
been more of an attractive nuisance; since we can't promise actual
stability, we should instead make proper uses more convenient.

JF Bastien's implementation proposal is summarized at
https://github.com/itanium-cxx-abi/cxx-abi/issues/74

I implement this by adding new --params for the two sizes.  Targets can
override these values in targetm.target_option.override() to support a range
of values for the generic target; otherwise, both will default to the L1
cache line size.

64 bytes still seems correct for all x86.

I'm not sure why he proposed 64/64 for generic 32-bit ARM, since the Cortex
A9 has a 32-byte cache line, so I'd think 32/64 would make more sense.

He proposed 64/128 for generic AArch64, but since the A64FX now has a 256B
cache line, I've changed that to 64/256.

Other arch maintainers are invited to set ranges for their generic targets
if that seems better than using the default cache line size for both values.

With the above choice to reject stability as a goal, getting these values
"right" is now just a matter of what we want the default optimization to be,
and we can feel free to adjust them as CPUs with different cache lines
become more and less common.

gcc/ChangeLog:

	* params.opt: Add destructive-interference-size and
	constructive-interference-size.
	* doc/invoke.texi: Document them.
	* config/aarch64/aarch64.c (aarch64_override_options_internal):
	Set them.
	* config/arm/arm.c (arm_option_override): Set them.
	* config/i386/i386-options.c (ix86_option_override_internal):
	Set them.

gcc/c-family/ChangeLog:

	* c.opt: Add -Winterference-size.
	* c-cppbuiltin.c (cpp_atomic_builtins): Add __GCC_DESTRUCTIVE_SIZE
	and __GCC_CONSTRUCTIVE_SIZE.

gcc/cp/ChangeLog:

	* constexpr.c (maybe_warn_about_constant_value):
	Complain about std::hardware_destructive_interference_size.
	(cxx_eval_constant_expression): Call it.
	* decl.c (cxx_init_decl_processing): Check
	--param *-interference-size values.

libstdc++-v3/ChangeLog:

	* include/std/version: Define __cpp_lib_hardware_interference_size.
	* libsupc++/new: Define hardware interference size variables.

gcc/testsuite/ChangeLog:

	* g++.dg/warn/Winterference.H: New file.
	* g++.dg/warn/Winterference.C: New test.
	* g++.target/aarch64/interference.C: New test.
	* g++.target/arm/interference.C: New test.
	* g++.target/i386/interference.C: New test.
2021-09-13 12:28:06 -04:00
Jonathan Wakely
89cf858571 libstdc++: Implement std::atomic<T*>::compare_exchange_weak
For some reason r170217 didn't add compare_exchange_weak to the
__atomic_base<T*> partial specialization, and so weak compare exchange
operations on pointers use compare_exchange_strong instead.

This adds __atomic_base<T*>::compare_exchange_weak and then uses it in
std::atomic<T*>::compare_exchange_weak.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/atomic_base.h (__atomic_base<P*>::compare_exchange_weak):
	Add new functions.
	* include/std/atomic (atomic<T*>::compare_exchange_weak): Use
	it.
2021-09-02 18:22:33 +01:00
Jonathan Wakely
892400f1f2 libstdc++: Tweak whitespace in <atomic>
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/std/atomic: Tweak whitespace.
2021-09-02 18:22:32 +01:00
Jonathan Wakely
dba1ab2122 libstdc++: Remove "no stronger" assertion in compare exchange [PR102177]
P0418R2 removed some preconditions from std::atomic::compare_exchange_*
but we still enforce them via __glibcxx_assert. This removes those
assertions.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR c++/102177
	* include/bits/atomic_base.h (__is_valid_cmpexch_failure_order):
	New function to check if a memory order is valid for the failure
	case of compare exchange operations.
	(__atomic_base<I>::compare_exchange_weak): Simplify assertions
	by using __is_valid_cmpexch_failure_order.
	(__atomic_base<I>::compare_exchange_strong): Likewise.
	(__atomic_base<P*>::compare_exchange_weak): Likewise.
	(__atomic_base<P*>::compare_exchange_strong): Likewise.
	(__atomic_impl::compare_exchange_weak): Add assertion.
	(__atomic_impl::compare_exchange_strong): Likewise.
	* include/std/atomic (atomic::compare_exchange_weak): Likewise.
	(atomic::compare_exchange_strong): Likewise.
2021-09-02 18:21:23 +01:00
Jonathan Wakely
5b73abd1a5 libstdc++: Define std::invoke_r for C++23 (P2136R3)
We already supported this feature as std::__invoke<R>, for internal use.
This just adds a public version of it to <functional>.

Internal uses should continue to include <bits/invoke.h> and use
std::__invoke<R> so that they don't need to include all of <functional>.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/std/functional (invoke_r): Define.
	* include/std/version (__cpp_lib_invoke_r): Define.
	* testsuite/20_util/function_objects/invoke/version.cc: Check
	for __cpp_lib_invoke_r as well as __cpp_lib_invoke.
	* testsuite/20_util/function_objects/invoke/4.cc: New test.
2021-09-02 17:48:45 +01:00
Jonathan Wakely
ef7becc9c8 libstdc++: Add valid range checks to std::span constructors [PR98421]
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/98421
	* include/std/span (span(Iter, size_type), span(Iter, Iter)):
	Add valid range checks.
	* testsuite/23_containers/span/cons_1_assert_neg.cc: New test.
	* testsuite/23_containers/span/cons_2_assert_neg.cc: New test.
2021-08-31 19:13:55 +01:00
Jonathan Wakely
763eb1f192 libstdc++: Add missing return for atomic timed wait [PR102074]
This adds a missing return statement to the non-futex wait-until
operation.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/102074
	* include/bits/atomic_timed_wait.h (__timed_waiter_pool)
	[!_GLIBCXX_HAVE_PLATFORM_TIMED_WAIT]: Add missing return.
2021-08-31 17:36:12 +01:00
Jonathan Wakely
feec7ef667 libstdc++: Improve error handling in Net TS name resolution
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/experimental/internet (__make_resolver_error_code):
	Handle EAI_SYSTEM errors.
	(basic_resolver_results): Use __make_resolver_error_code. Use
	Glibc NI_MAXHOST and NI_MAXSERV values for buffer sizes.
2021-08-31 17:36:11 +01:00
Jonathan Wakely
754fca77e8 libstdc++: Fix std::allocator<void> for versioned namespace
Removing the allocator<void> specialization for the versioned namespace
breaks _Extptr_allocator<void> because the allocator<void>
specialization was still declared in <bits/memoryfwd.h>, making it an
incomplete type.  It wrong to remove that specialization anyway, because
it is still needed pre-C++20.

This removes the #if ! _GLIBCXX_INLINE_VERSION check, so that
allocator<void> is still explicitly specialized for the versioned
namespace, consistent with the normal unversioned namespace mode.

To make _Extptr_allocator<void> usable as a ProtoAllocator, this change
adds a default constructor and converting constructor. That is
consistent with std::allocator<void> since C++20 (and harmless to do for
earlier standards).

I'm also explicitly specializing allocator_traits<allocator<void>> so
that it doesn't need to use allocator<void>::construct and destroy.
Doing that allows those members to be removed, further simplifying
allocator<void>.  That new explicit specialization can delete the
allocate, deallocate and max_size members, which are always ill-formed
for allocator<void>.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/alloc_traits.h (allocator_traits): Add explicit
	specialization for allocator<void>. Improve doxygen comments.
	* include/bits/allocator.h (allocator<void>): Restore for the
	versioned namespace.
	(allocator<void>::construct, allocator<void>::destroy): Remove.
	* include/ext/extptr_allocator.h (_Extptr_allocator<void>):
	Add default constructor and converting constructor.
2021-08-28 14:37:19 +01:00
Jonathan Wakely
dd3e5859fc libstdc++: Fix comment typo
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/stl_uninitialized.h: Fix typo in comment.
2021-08-28 11:52:22 +01:00
Jonathan Wakely
952095bb05 libstdc++: Name std::function template parameter
This avoids "<template-parameter-2-2>" being shown in the diagnostics
for ill-formed uses of std::function constructor:

In instantiation of 'std::function<_Res(_ArgTypes ...)>::function(_Functor&&)
[with _Functor = f(f()::_Z1fv.frame*)::<lambda()>;
<template-parameter-2-2> = void; _Res = void; _ArgTypes = {}]'

Instead we get:

In instantiation of 'std::function<_Res(_ArgTypes ...)>::function(_Functor&&)
[with _Functor = f(f()::_Z1fv.frame*)::<lambda()>;
_Constraints = void; _Res = void; _ArgTypes = {}]'

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/std_function.h (function::function(F&&)): Give
	name to defaulted template parameter, to improve diagnostics.
	Use markdown for more doxygen comments.
2021-08-28 11:52:22 +01:00
Jonathan Wakely
3a32a8ad7c libstdc:: Use markdown for Doxygen comments in std::function
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/std_function.h (function): Adjust doxygen
	comments.
	* include/bits/unique_ptr.h (make_unique_for_overwrite):
	Change parameter name to match doxygen comment.
2021-08-27 00:12:54 +01:00
Jonathan Wakely
d38d26be33 libstdc++: Avoid a move in std::function construction (LWG 2447)
This makes the std::function constructor use perfect forwarding, to
avoid an unnecessary move-construction of the target. This means we need
to rewrite the _Function_base::_Base_manager::_M_init_functor function
to use a forwarding reference, and so can reuse it for the clone
operation.

Also simplify the SFINAE constraints on the constructor, by combining
the !is_same_v<remove_cvref_t<F>, function> constraint into the
_Callable trait.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/std_function.h (_function_base::_Base_manager):
	Replace _M_init_functor with a function template using a
	forwarding reference, and a pair of _M_create function
	templates. Reuse _M_create for the clone operation.
	(function::_Decay_t): New alias template.
	(function::_Callable): Simplify by using _Decay.
	(function::function(F)): Change parameter to forwarding
	reference, as per LWG 2447. Add noexcept-specifier. Simplify
	constraints.
	(function::operator=(F&&)): Add noexcept-specifier.
	* testsuite/20_util/function/cons/lwg2774.cc: New test.
	* testsuite/20_util/function/cons/noexcept.cc: New test.
2021-08-27 00:12:54 +01:00
Jonathan Wakely
8cf428bfd3 libstdc++: Add static assertions for std::function requirements
Add static assertions to std::function, so that more user-friendly
diagnostics are given when trying to store a non-copyable target object.

These preconditions were added as "Mandates:" by LWG 2447, but I'm
committing them separately from implementing that, to allow just this
change to be backported more easily.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/std_function.h (function::function(F)): Add
	static assertions to check constructibility requirements.
2021-08-27 00:12:54 +01:00
Jonathan Wakely
cd67d138ec libstdc++: Make Networking TS headers more portable [PR100285]
Add more preprocessor conditions to check for constants being defined
before using them, so that the Networking TS headers can be compiled on
a wider range of platforms.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/100285
	* configure.ac: Check for O_NONBLOCK.
	* configure: Regenerate.
	* include/experimental/internet: Include <ws2tcpip.h> for
	Windows.  Use preprocessor conditions around more constants.
	* include/experimental/socket: Use preprocessor conditions
	around more constants.
	* testsuite/experimental/net/internet/resolver/base.cc: Only use
	constants when the corresponding C macro is defined.
	* testsuite/experimental/net/socket/basic_socket.cc: Likewise.
	* testsuite/experimental/net/socket/socket_base.cc: Likewise.
	Make preprocessor checks more fine-grained.
2021-08-26 12:41:28 +01:00
Jonathan Wakely
0163bbaaef libstdc++: Fix non-reserved names in <valarray>
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/std/valarray: Uglify 'func' parameters.
	* testsuite/17_intro/names.cc: Add 'func' to checks.
2021-08-25 22:29:26 +01:00
Jonathan Wakely
ead408529d libstdc++: Fix conditions for optimizing uninitialized algos [PR102064]
While laying some groundwork for constexpr std::vector, I noticed some
bugs in the std::uninitialized_xxx algorithms. The conditions being
checked for optimizing trivial cases were not quite right, as shown in
the examples in the PR.

This consolidates the checks into a single macro. The macro has
appropriate definitions for C++98 or for later standards, to avoid a #if
everywhere the checks are used. For C++11 and later the check makes a
call to a new function doing a static_assert to ensure we don't use
assignment in cases where construction would have been invalid.
Extracting that check to a separate function will be useful for
constexpr std::vector, as that can't use std::uninitialized_copy
directly because it isn't constexpr).

The consolidated checks mean that some slight variations in static
assert message are gone, as there is only one place that does the assert
now. That required adjusting some tests. As part of that the redundant
89164_c++17.cc test was merged into 89164.cc which is compiled as C++17
by default now, but can also use other -std options if the
C++17-specific error is made conditional with a target selector.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/102064
	* include/bits/stl_uninitialized.h (_GLIBCXX_USE_ASSIGN_FOR_INIT):
	Define macro to check conditions for optimizing trivial cases.
	(__check_constructible): New function to do static assert.
	(uninitialized_copy, uninitialized_fill, uninitialized_fill_n):
	Use new macro.
	* testsuite/20_util/specialized_algorithms/uninitialized_copy/1.cc:
	Adjust dg-error pattern.
	* testsuite/23_containers/vector/cons/89164.cc: Likewise. Add
	C++17-specific checks from 89164_c++17.cc.
	* testsuite/23_containers/vector/cons/89164_c++17.cc: Removed.
	* testsuite/20_util/specialized_algorithms/uninitialized_copy/102064.cc:
	New test.
	* testsuite/20_util/specialized_algorithms/uninitialized_copy_n/102064.cc:
	New test.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill/102064.cc:
	New test.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill_n/102064.cc:
	New test.
2021-08-25 22:28:47 +01:00
Jonathan Wakely
2cd229dec8 libstdc++: Remove __gnu_cxx::rope::erase(size_type) [PR102048]
This function claims to remove a single character at index p, but it
actually removes p+1 characters beginning at p. So r.erase(0) removes
the first character, but r.erase(1) removes the second and third, and
r.erase(2) removes the second, third and fourth. This is not a useful
API.

The overload is present in the SGI STL <stl_rope.h> header that we
imported, but it isn't documented in the API reference. The erase
overloads that are documented are:

erase(const iterator& p)
erase(const iterator& f, const iterator& l)
erase(size_type i, size_type n);

Having an erase(size_type p) overload that erases a single character (as
the comment says it does) might be useful, but would be inconsistent
with std::basic_string::erase(size_type p = 0, size_type n = npos),
which erases from p to the end of the string when called with a single
argument.

Since the function isn't part of the documented API, doesn't do what it
claims to do (or anything useful) and "fixing" it would leave it
inconsistent with basic_string, I'm just removing that overload.

libstdc++-v3/ChangeLog:

	PR libstdc++/102048
	* include/ext/rope (rope::erase(size_type)): Remove broken
	function.
2021-08-25 22:28:46 +01:00
Jonathan Wakely
037ef219b2 libstdc++: Add std::is_layout_compatible trait for C++20
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/std/type_traits (is_layout_compatible): Define.
	(is_corresponding_member): Define.
	* include/std/version (__cpp_lib_is_layout_compatible): Define.
	* testsuite/20_util/is_layout_compatible/is_corresponding_member.cc:
	New test.
	* testsuite/20_util/is_layout_compatible/value.cc: New test.
	* testsuite/20_util/is_layout_compatible/version.cc: New test.
	* testsuite/20_util/is_pointer_interconvertible/with_class.cc:
	New test.
	* testsuite/23_containers/span/layout_compat.cc: Do not use real
	std::is_layout_compatible trait if available.
2021-08-24 16:12:44 +01:00
Jonathan Wakely
1a129376bb libstdc++: Add default template argument to basic_istream_view
The standard shows this default template argument in the <ranges>
synopsis, but it was missing in libstdc++.

libstdc++-v3/ChangeLog:

	* include/std/ranges (basic_istream_view): Add default template
	argument.
	* testsuite/std/ranges/istream_view.cc: Check it.
2021-08-23 16:17:10 +01:00
Jonathan Wakely
85a7095950 libstdc++: Don't check always-true condition [PR101965]
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/101965
	* include/std/charconv (__to_chars_i): Remove redundant check.
2021-08-19 14:57:41 +01:00
Jonathan Wakely
0187e0d736 libstdc++: Fix move construction of std::tuple with array elements [PR101960]
An array member cannot be direct-initialized in a ctor-initializer-list,
so use the base class' move constructor, which does the right thing for
both arrays and non-arrays.

This constructor could be defaulted, but that would make it trivial for
some specializations, which would change the argument passing ABI. Do
that for the versioned namespace only.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	PR libstdc++/101960
	* include/std/tuple (_Tuple_impl(_Tuple_impl&&)): Use base
	class' move constructor. Define as defaulted for versioned
	namespace.
	* testsuite/20_util/tuple/cons/101960.cc: New test.
2021-08-19 13:02:12 +01:00
Jonathan Wakely
30b300de8e libstdc++: Improve doxygen docs for smart pointers
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/shared_ptr.h: Add @since and @headerfile tags.
	* include/bits/unique_ptr.h: Add @headerfile tags.
2021-08-19 13:02:12 +01:00
Jonathan Wakely
c8a1cf1a7a libstdc++: Tweak whitespace
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/stl_tree.h: Tweak whitespace.
2021-08-19 13:02:11 +01:00
Jonathan Wakely
4fb471afc4 libstdc++: Improve doxygen documentation for std::unique_ptr
Add more detailed documentation for unique_ptr and related components.

The new alias templates for the _MakeUniq SFINAE helper make the
generated docs look better too.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/unique_ptr.h (default_delete): Add @since tag.
	(unique_ptr, unique_ptr<T[]>): Likewise. Improve @brief.
	(make_unique, make_unique_for_overwrite): Likewise. Add @tparam,
	@param, and @returns.
	(_MakeUniq): Move to __detail namespace. Add alias template
	helpers.
2021-08-18 15:13:08 +01:00
Jonathan Wakely
828176ba49 libstdc++: Improve doxygen comments in <bits/stl_function.h>
Add notes about deprecation and modern replacements. Fix bogus
"memory_adaptors" group name. Use markdown for formatting.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/stl_function.h: Improve doxygen comments.
2021-08-18 15:07:16 +01:00
Jonathan Wakely
aba938d6c3 libstdc++: Enable doxygen processing for C++20 components
Improve grouping, add @since and @deprecated information.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* doc/doxygen/user.cfg.in (PREDEFINED): Enable doxygen
	processing for C++20 components and components that depend on
	compiler features.
	* include/bits/stl_algo.h (random_shuffle): Use @deprecated.
	* include/std/type_traits: Improve doxygen comments for C++20
	traits.
2021-08-18 15:02:31 +01:00
Jonathan Wakely
37620d5751 libstdc++: Simplify n-ary arithmetic promotion traits
The std::complex partial specializations have been unnecessary since
774c3d8647

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/ext/type_traits.h (__promote_2, __promote_3)
	(__promote_4): Redfine as alias templates using __promoted_t.
	* include/std/complex (__promote_2): Remove partial
	specializations for std::complex.
2021-08-18 14:26:39 +01:00
Jonathan Wakely
de44eee5d5 libstdc++: Minor optimization for min/max/minmax
The debug mode checks for a valid range are redundant when we have an
initializer_list argument, because we know it's a valid range already.
By making std::min(initialier_list<T>) call the internal __min_element
function directly we avoid a function call and skip those checks. The
same can be done for the overload taking a comparison function, and also
for the std::max and std::minmax overloads for initializer_list
arguments.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/bits/stl_algo.h (min(initializer_list<T>))
	(min(initializer_list<T>, Compare)): Call __min_element directly to
	avoid redundant debug checks for valid ranges.
	(max(initializer_list<T>), max(initializer_list<T>, Compare)):
	Likewise, for __max_element.
	(minmax(initializer_list<T>), minmax(initializer_list<T>, Compare)):
	Likewise, for __minmax_element.
2021-08-18 14:26:39 +01:00
Jonathan Wakely
085c2f8f0e libstdc++: Fix CTAD for debug sequence containers
This fixes some 23_containers/*/cons/deduction.cc failures seen with
-std=c++17/-D_GLIBCXX_DEBUG, caused by non-immediate errors when
substituting template arguments into an incorrect specialization of the
std::__cxx1998 base class. This happens because the size_type member of
the debug container is _Base_type::size_type, so is non-deducible, and
the deduced types get substituted into _Base_type, triggering the
static_assert that checks the allocator's value_type matches the
container's.

The solution is to make the C(size_type, const T&, const Alloc&)
constructors of the debug sequence containers non-deducible. In order to
make CTAD work again deduction guides that use std::size_t for the first
argument are added.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

	* include/debug/deque (deque(size_type, const T&, const A&)):
	Prevent class template argument deduction and replace with a
	deduction guide.
	* include/debug/forward_list (forward_list(size_type, const T&, const A&)):
	Likewise.
	* include/debug/list (list(size_type, const T&, const A&)):
	Likewise.
	* include/debug/vector (vector(size_type, const T&, const A&)):
	Likewise.
2021-08-18 14:26:38 +01:00