4710 Commits

Author SHA1 Message Date
Jonathan Wakely
632183ddcc libstdc++: Avoid stack overflow in std::vector (PR 94540)
The std::__uninitialized_default_n algorithm used by std::vector creates
an initial object as a local variable then copies that into the
destination range. If the object is too large for the stack this
crashes. We should create the first object directly into the
destination and then copy it from there.

This doesn't fix the bug for C++98, because in that case the initial
value is created as a default argument of the vector constructor i.e. in
the user's code, not inside libstdc++. We can't prevent that.

	PR libstdc++/94540
	* include/bits/stl_uninitialized.h (__uninitialized_default_1<true>):
	Construct the first value at *__first instead of on the stack.
	(__uninitialized_default_n_1<true>): Likewise.
	Improve comments on several of the non-standard algorithms.
	* testsuite/20_util/specialized_algorithms/uninitialized_default/94540.cc:
	New test.
	* testsuite/20_util/specialized_algorithms/uninitialized_default_n/94540.cc:
	New test.
	* testsuite/20_util/specialized_algorithms/uninitialized_value_construct/94540.cc:
	New test.
	* testsuite/20_util/specialized_algorithms/uninitialized_value_construct_n/94540.cc:
	New test.
	* testsuite/23_containers/vector/cons/94540.cc: New test.
2020-06-17 22:49:06 +01:00
Jonathan Wakely
94b94c0bb1 libstdc++: Fix tests for uninitialized_value_construct_n
In my recent r11-1460 commit the tests had been "improved" before
commit, and no longer exercised the code paths changed by the patch.

This restores what I originally tested, so that the tests fail before
the r11-1460 change and pass after it.

	* testsuite/20_util/specialized_algorithms/uninitialized_default_n/sizes.cc:
	Replace Value type with int so trivial code path is used.
	* testsuite/20_util/specialized_algorithms/uninitialized_value_construct_n/sizes.cc:
	Likewise.
2020-06-17 21:23:35 +01:00
Jonathan Wakely
c9dce3b15e libstdc++: Handle non-integral sizes in std::uninitialized_fill_n
The std::uninitialized_fill_n algorithm uses sd::fill_n for trivial
types, but that algorithm has a stronger requirement that the Size
parameter is convertible to an integral type. As the new test shows,
there are types which are valid for std::uninitialized_fill_n but which
produce a different result when converted to an integral type, or cannot
be converted at all. Only use the std::fill_n optimization when the Size
type is already an integral type.

The std::__uninitialized_default_n extension has the same problem, and
so does C++17's std::uninitialized_value_construct_n which uses it.

	* include/bits/stl_uninitialized.h (uninitialized_fill_n): Only
	use std::fill_n when the size is an integral type.
	(__uninitialized_default_n): Likewise.
	* testsuite/20_util/specialized_algorithms/uninitialized_default_n/sizes.cc:
	New test.
	* testsuite/20_util/specialized_algorithms/uninitialized_fill_n/sizes.cc:
	New test.
	* testsuite/20_util/specialized_algorithms/uninitialized_value_construct_n/sizes.cc:
	New test.
2020-06-17 20:55:06 +01:00
Jonathan Wakely
cc799df98f libstdc++: Enforce copyable/movable checks in std::atomic
C++20 adds some new preconditions to std::atomic, which weren't
previously checked by our implementation.

	* include/std/atomic (atomic): Add static assertions.
	* testsuite/29_atomics/atomic/requirements/types_neg.cc: New test.
2020-06-16 22:34:55 +01:00
Patrick Palka
92bed03609 c++: Improve access checking inside templates [PR41437]
This patch generalizes our existing functionality for deferring access
checking of typedefs when parsing a function or class template to now
defer all kinds of access checks until template instantiation time,
including member function and member object accesses.

Since all access checks eventually go through enforce_access, the main
component of this patch is new handling inside enforce_access to defer
the current access check if we're inside a template.  The bulk of the
rest of the patch consists of removing now-unneeded code pertaining to
suppressing access checks inside templates or pertaining to
typedef-specific access handling.  Renamings and other changes with no
functional impact have been split off into the followup patch.

gcc/cp/ChangeLog:

	PR c++/41437
	PR c++/47346
	* call.c (enforce_access): Move to semantics.c.
	* cp-tree.h (enforce_access): Delete.
	(get_types_needing_access_check): Delete.
	(add_typedef_to_current_template_for_access_check): Delete.
	* decl.c (make_typename_type): Adjust accordingly.  Use
	check_accessibility_of_qualified_id instead of directly using
	perform_or_defer_access_check.
	* parser.c (cp_parser_template_declaration_after_parameters):
	Don't push a dk_no_check access state when parsing a template.
	* pt.c (get_types_needing_access_check): Delete.
	(append_type_to_template_for_access_check_1): Delete.
	(perform_typedefs_access_check): Adjust.  If type_decl is a
	FIELD_DECL, also check its DECL_CONTEXT for dependence. Use
	tsubst_copy instead of tsubst to substitute into type_decl so
	that we substitute into the DECL_CONTEXT of a FIELD_DECL.
	(append_type_to_template_for_access_check): Delete.
	* search.c (accessible_p): Remove the processing_template_decl
	early exit.
	* semantics.c (enforce_access): Moved from call.c.  If we're
	parsing a template and the access check failed, add the check to
	TI_TYPEDEFS_NEEDING_ACCESS_CHECKING.
	(perform_or_defer_access_check): Adjust comment.
	(add_typedef_to_current_template_for_access_check): Delete.
	(check_accessibility_of_qualified_id):  Adjust accordingly.
	Exit early if the scope is dependent.

gcc/testsuite/ChangeLog:

	PR c++/41437
	PR c++/47346
	* g++.dg/cpp2a/concepts-using2.C: Adjust.
	* g++.dg/lto/20081219_1.C: Adjust.
	* g++.dg/lto/20091002-1_0.C: Adjust.
	* g++.dg/lto/pr65475c_0.C: Adjust.
	* g++.dg/opt/dump1.C: Adjust.
	* g++.dg/other/pr53574.C: Adjust.
	* g++.dg/template/access30.C: New test.
	* g++.dg/template/access31.C: New test.
	* g++.dg/wrappers/wrapper-around-type-pack-expansion.C: Adjust.

libstdc++-v3/ChangeLog:

	PR libstdc++/94003
	* testsuite/20_util/is_constructible/94003.cc: New test.
2020-06-16 08:21:33 -04:00
Jonathan Wakely
b6ab9ecd55 libstdc++: Update value of __cpp_lib_constexpr_char_traits for C++20
Although not required by SD-6 or the C++20 draft, we define the macro
__cpp_lib_constexpr_char_traits to indicate support for P0432R1. This
updates the value in C++20 mode for the P1032R1 changes to char_traits.

	* include/bits/char_traits.h (__cpp_lib_constexpr_char_traits):
	Update value for C++20.
	* include/std/version (__cpp_lib_constexpr_char_traits): Likewise.
	* testsuite/21_strings/char_traits/requirements/constexpr_functions_c++17.cc:
	Update expected value.
	* testsuite/21_strings/char_traits/requirements/constexpr_functions_c++20.cc:
	Likewise.
2020-06-15 14:31:26 +01:00
Paul Keir
eb11134d0c libstdc++: Fix char_traits move with overlap
Upon constexpr evaluation, char_traits move uses copy_backward, but its
last argument should be to the range end rather than its beginning.

2020-06-12  Paul Keir  <paul.keir@uws.ac.uk>

	* include/bits/char_traits.h (char_traits::move): constexpr move with
	overlap was using copy_backward incorrectly.
	* testsuite/21_strings/char_traits/requirements/constexpr_functions_c++20.cc:
	New test.
2020-06-15 14:31:26 +01:00
Jonathan Wakely
e784f98027 libstdc++: Improve tests for std::atomic_flag
The tests for clear() and test_and_set() didn't cover all cases.

	* testsuite/29_atomics/atomic_flag/clear/1.cc: Also test clear()
	when the value is currently set.
	* testsuite/29_atomics/atomic_flag/test_and_set/explicit.cc:
	Actually check the return value.
	* testsuite/29_atomics/atomic_flag/test_and_set/implicit.cc:
	Likewise.
2020-06-12 10:43:06 +01:00
Jonathan Wakely
17412a74c5 libstdc++: Make std::atomic_flag::test members const
Also fix the tests so they run without an explicit -std=gnu++2a in the
RUNTESTFLAGS, and test the new function on const-qualified objects.

	* include/bits/atomic_base.h (atomic_flag::test): Add missing
	const qualifiers.
	* testsuite/29_atomics/atomic_flag/test/explicit.cc: Add
	dg-options and verify results of test function.
	* testsuite/29_atomics/atomic_flag/test/implicit.cc: Likewise.
2020-06-12 10:31:07 +01:00
Jonathan Wakely
b32eea9c0c libstdc++: Fix istream::ignore discarding too many chars (PR 94749)
The current code assumes that if the next character in the stream is
equal to the delimiter then we stopped because we saw that delimiter,
and so discards it.  But in the testcase for the PR we stop because we
reached the maximum number of characters, and it's coincidence that the
next character equals the delimiter. We should not discard the next
character in that case.

The fix is to check that we haven't discarded __n characters already,
instead of checking whether the next character equals __delim. Because
we've already checked for EOF, if we haven't discarded __n yet then we
know we stopped because we saw the delimiter. On the other hand, if the
next character is the delimiter we don't know if that's why we stopped.

	PR libstdc++/94749
	* include/bits/istream.tcc (basic_istream::ignore(streamsize, CharT)):
	Only discard an extra character if we didn't already reach the
	maximum number.
	* src/c++98/istream.cc (istream::ignore(streamsiz, char))
	(wistream::ignore(streamsize, wchar_t)): Likewise.
	* testsuite/27_io/basic_istream/ignore/char/94749.cc: New test.
	* testsuite/27_io/basic_istream/ignore/wchar_t/94749.cc: New test.
2020-06-11 18:41:37 +01:00
Patrick Palka
a73051a0ea libstdc++: Fix some ranges algos optimizations [PR95578]
ranges::copy and a number of other ranges algorithms have unwrapping
optimizations for iterators of type __normal_iterator, move_iterator and
reverse_iterator.  But in the checks that guard these optimizations we
currently only test that the iterator of the iterator/sentinel pair has
the appropriate type before proceeding with the corresponding
optimization, and do not also test the sentinel type.

This breaks the testcase in this PR because this testcase constructs via
range adaptors a range whose begin() is a __normal_iterator and whose
end() is a custom sentinel type, and then performs ranges::copy on it.
From there we bogusly perform the __normal_iterator unwrapping
optimization on this iterator/sentinel pair, which immediately leads to
a constraint failure since the custom sentinel type does not model
sentinel_for<int*>.

This patch fixes this issue by refining each of the problematic checks
to also test that the iterator and sentinel types are the same before
applying the corresponding unwrapping optimization.  Along the way, some
code simplifications are made.

libstdc++-v3/ChangeLog:

	PR libstdc++/95578
	* include/bits/ranges_algo.h (__lexicographical_compare_fn):
	Also check that the iterator and sentinel have the same type before
	applying the unwrapping optimization for __normal_iterator.
	Split the check into two, one for the first iterator/sentinel
	pair and another for second iterator/sentinel pair.  Remove uses
	of __niter_base, and remove uses of std::move on a
	__normal_iterator.
	* include/bits/ranges_algobase.h (__equal_fn): Likewise.
	(__copy_or_move): Likewise.  Perform similar adjustments for
	the reverse_iterator and move_iterator optimizations.  Inline
	the checks into the if-constexprs, and use using-declarations to
	make them less visually noisy.  Remove uses of __niter_wrap.
	(__copy_or_move_backward): Likewise.
	* testsuite/25_algorithms/copy/95578.cc: New test.
	* testsuite/25_algorithms/copy_backward/95578.cc: New test.
	* testsuite/25_algorithms/equal/95578.cc: New test.
	* testsuite/25_algorithms/lexicographical_compare/95578.cc: New test.
	* testsuite/25_algorithms/move/95578.cc: New test.
	* testsuite/25_algorithms/move_backward/95578.cc: New test.
2020-06-10 17:37:53 -04:00
François Dumont
3a391adf7a libstdc++: Extend memcmp optimization in std::lexicographical_compare
Make the memcmp optimization work for std::deque iterators and safe
iterators.

Co-authored-by: Jonathan Wakely  <jwakely@redhat.com>

libstdc++-v3/ChangeLog:

2020-06-08  François Dumont  <fdumont@gcc.gnu.org>
	    Jonathan Wakely  <jwakely@redhat.com>

	* include/bits/deque.tcc (__lex_cmp_dit): New.
	(__lexicographical_compare_aux1): Define overloads for deque
	iterators.
	* include/bits/stl_algobase.h (__lexicographical_compare::__3way):
	New static member function.
	(__lexicographical_compare<true>::__3way): Likewise.
	(__lexicographical_compare<true>::__lc): Use __3way.
	(__lexicographical_compare_aux): Rename to
	__lexicographical_compare_aux1 and declare overloads for deque
	iterators.
	(__lexicographical_compare_aux): Define new forwarding function
	that calls __lexicographical_compare_aux1 and declare new overloads
	for safe iterators.
	(lexicographical_compare): Do not use __niter_base on
	parameters.
	* include/debug/safe_iterator.tcc
	(__lexicographical_compare_aux): Define overloads for safe
	iterators.
	* testsuite/25_algorithms/lexicographical_compare/1.cc: Add
	checks with random access iterators.
	* testsuite/25_algorithms/lexicographical_compare/deque_iterators/1.cc:
	New test.
2020-06-10 17:48:56 +01:00
Jonathan Wakely
733167f9d5 libstdc++: Define converting assignment operator for std::move_iterator
As clarified by LWG 3265, std::move_iterator is supposed to have an
assignment operator that converts from a different specialization of
std::move_iterator, which performs an assignment. That has always been
missing from libstdc++, so assigning a different type actually performs
a converting construction, then an assignment. This is non-conforming
for the (fairly contrived) case where the converting assignment is
well-formed but the converting construction is not.

	* include/bits/stl_iterator.h (move_iterator::operator=): Define.
	* testsuite/24_iterators/move_iterator/dr3265.cc: New test.
2020-06-09 22:16:24 +01:00
Jonathan Wakely
d364705791 libstdc++: Define std::bad_optional_access constructor as defaulted
The standard requires that std::bad_optional_access' default
constructor has a non-throwing exception specification.

	* include/std/optional (bad_optional_access): Define default
	constructor and destructor as defaulted.
	* testsuite/20_util/optional/bad_access.cc: New test.
2020-06-09 22:14:43 +01:00
Jonathan Wakely
a37fbff12c libstdc++: Fix failing tests
These started failing with the previous commit, because I forgot to add
the tests after adjusting them.

	* testsuite/20_util/default_delete/48631_neg.cc: Adjust dg-error
	line number.
	* testsuite/20_util/default_delete/void_neg.cc: Likewise.
2020-06-08 21:34:46 +01:00
Jonathan Wakely
187da2ce31 libstdc++: Implement operator<< for std::unique_ptr (LWG 2948)
libstdc++-v3/ChangeLog:

	* include/bits/unique_ptr.h (operator<<): Define for C++20.
	* testsuite/20_util/unique_ptr/io/lwg2948.cc: New test.
2020-06-08 21:21:31 +01:00
François Dumont
4e05c918d2 libstdc++: Specialize copy/copy_n for istreambuf_iterator and deque iterators
Add __copy_n_a overloads for std::deque iterators to replace with C memmove
when possible. Expose std::copy_n implementation details in pre-C++11 modes
and use it for std::copy overloads.

libstdc++-v3/ChangeLog

	* include/bits/stl_algo.h (__copy_n_a): Move to ...
	* include/bits/stl_algobase.h (__copy_n_a): ...here. Add __strict
	parameter.
	(__copy_n_a(istreambuf_iterator<>, _Size, _Deque_iterator<>, bool)):
	Declare.
	(__niter_base(const _Safe_iterator<_Ite, _Seq,
	random_access_iterator_tag>&)): Declare.
	(__copy_move_a2(istreambuf_iterator<>, istreambuf_iterator<>,
	_Deque_iterator<>)): Declare.
	* include/bits/deque.tcc
	(__copy_move_a2(istreambuf_iterator<>, istreambuf_iterator<>,
	_Deque_iterator<>)): New.
	(__copy_n_a(istreambuf_iterator<>, _Size, _Deque_iterator<>, bool)):
	New.
	* include/bits/streambuf_iterator.h
	(__copy_n_a(istreambuf_iterator<>, _Size, _CharT*, bool)): Adapt.
	* include/debug/safe_iterator.tcc (__niter_base): New.
	* testsuite/25_algorithms/copy/streambuf_iterators/char/4.cc
	(test03): New.
	* testsuite/25_algorithms/copy/streambuf_iterators/char/debug/deque_neg.cc:
	New test.
	* testsuite/25_algorithms/copy_n/debug/istreambuf_ite_deque_neg.cc:
	New test.
	* testsuite/25_algorithms/copy_n/istreambuf_iterator/2.cc: New test.
	* testsuite/25_algorithms/copy_n/istreambuf_iterator/deque.cc:
	New test.
2020-06-04 22:27:47 +02:00
Jonathan Wakely
e1008cd1d8 libstdc++: Make std::copy_n work with negative and non-integral sizes
Since it was added in C++11, std::copy_n and std::ranges::copy_n should
do nothing given a negative size, but for random access iterators we add
the size to the iterator, possibly resulting in undefined behaviour.

Also, C++20 clarified that std::copy_n requires the Size type to be
convertible to an integral type. We previously assumed that it could be
directly used in arithmetic expressions, without conversion to an
integral type.

This also fixes a bug in the random_access_iterator_wrapper helper adds
some convenience aliases for using the iterator wrappers.

libstdc++-v3/ChangeLog:

	* include/bits/ranges_algobase.h (__copy_n_fn): Only call
	ranges::copy for positive values.
	* include/bits/stl_algo.h (copy_n): Convert Size argument to an
	integral type and only call __copy_n for positive values.
	* testsuite/util/testsuite_iterators.h
	(random_access_iterator_wrapper::operator+=): Fix range check for
	negative values.
	(output_container, input_container, forward_container)
	(bidirectional_container, random_access_container): New alias
	templates.
	* testsuite/25_algorithms/copy_n/5.cc: New test.
2020-06-04 14:21:34 +01:00
Jonathan Wakely
eca833b812 libstdc++: Make debug containers prefer copy ctor to base ctor (PR 90102)
When given a type which can convert to any container-like type, the
C(const C&) copy constructor and C(const C::_Base&) converting
constructor are ambiguous. This change replaces the converting
constructor's parameter with a reference_wrapper-like type so that
calling that constructor requires an additional user-defined conversion.
This gives it a lower rank than the copy constructor, avoiding the
ambiguity.

While testing this change I discovered that __gnu_debug::forward_list
doesn't have a convering constructor from the std::forward_list base, so
this adds it.

We should probably consider whether the converting constructors should
be 'explicit' but I'm not changing that now.

libstdc++-v3/ChangeLog:

	PR libstdc++/90102
	* include/debug/deque (deque(const _Base&)): Replace parameter
	with a struct that wraps a const _Base&.
	* include/debug/forward_list (forward_list(_Base_ref)): New
	constructor.
	* include/debug/list (list(const _Base&)): Replace parameter
	with a struct that wraps a const _Base&.
	* include/debug/map.h (map(const _Base&)): Likewise.
	* include/debug/multimap.h (multimap(const _Base&)): Likewise.
	* include/debug/multiset.h (multiset(const _Base&)): Likewise.
	* include/debug/set.h (set(const _Base&)): Likewise.
	* include/debug/unordered_map (unordered_map(const _Base&))
	(unordered_multimap(const _Base&)): Likewise.
	* include/debug/unordered_set (unordered_set(const _Base&))
	(unordered_multiset(const _Base&)): Likewise.
	* testsuite/23_containers/vector/cons/destructible_debug_neg.cc:
	Adjust dg-error line number.
	* include/debug/vector (vector(const _Base&)): Likewise.
	* testsuite/23_containers/deque/debug/90102.cc: New test.
	* testsuite/23_containers/forward_list/debug/90102.cc: New test.
	* testsuite/23_containers/list/debug/90102.cc: New test.
	* testsuite/23_containers/map/debug/90102.cc: New test.
	* testsuite/23_containers/multimap/debug/90102.cc: New test.
	* testsuite/23_containers/multiset/debug/90102.cc: New test.
	* testsuite/23_containers/set/debug/90102.cc: New test.
	* testsuite/23_containers/unordered_map/debug/90102.cc: New test.
	* testsuite/23_containers/unordered_multimap/debug/90102.cc: New test.
	* testsuite/23_containers/unordered_multiset/debug/90102.cc: New test.
	* testsuite/23_containers/unordered_set/debug/90102.cc: New test.
	* testsuite/23_containers/vector/debug/90102.cc: New test.
2020-06-02 18:13:33 +01:00
Jonathan Wakely
118158b646 libstdc++: Fix __gnu_test::input_iterator_wrapper::operator++(int)
I noticed recently that our input_iterator_wrapper utility for writing
tests has the following post-increment operator:

    void
    operator++(int)
    {
      ++*this;
    }

That fails to meet the Cpp17InputIterator requirement that *r++ is
valid. This change makes it return a non-void proxy type that can be
deferenced to produce another proxy, which is convertible to the
value_type. The second proxy converts to const T& to ensure it can't be
written to.

	* testsuite/util/testsuite_iterators.h:
	(input_iterator_wrapper::operator++(int)): Return proxy object.
2020-06-01 18:30:47 +01:00
Jonathan Wakely
bbaec68c86 libstdc++: Fix atomic<FP>::load (PR 95282)
PR libstdc++/95282
	* include/bits/atomic_base.h (__atomic_impl::load): Add
	cv-qualifiers to parameter so that _Tp is deduced as the
	unqualified type.
	* testsuite/29_atomics/atomic_float/95282.cc: New test.
2020-05-27 22:55:21 +01:00
Jonathan Wakely
6c2582c040 libstdc++: Fix view adaptors for mixed-const sentinels and iterators (PR 95322)
The bug report is that transform_view's sentinel<false> cannot be
compared to its iterator<true>.  The comparison is supposed to use
operator==(iterator<Const>, sentinel<Const>) after converting
sentinel<false> to sentinel<true>. However, the operator== is a hidden
friend so is not a candidate when comparing iterator<true> with
sentinel<false>. The required conversion would only happen if we'd found
the operator, but we can't find the operator until after the conversion
happens.

A new LWG issue has been reported, but not yet assigned a number.  The
solution suggested by Casey Carter is to make the hidden friends of the
sentinel types work with iterators of any const-ness, so that no
conversions are required.

Patrick Palka observed that join_view has a similar problem and a
similar fix is used for its sentinel.

	PR libstdc++/95322
	* include/std/ranges (transform_view::_Sentinel): Allow hidden
	friends to work with _Iterator<true> and _Iterator<false>.
	(join_view::_Sentinel): Likewise.
	* testsuite/std/ranges/adaptors/95322.cc: New test.
2020-05-27 22:08:15 +01:00
Jonathan Wakely
979e89a9a9 libstdc++: Fix std::reverse_iterator comparisons (PR 94354)
The std::reverse_iterator comparisons have always been implemented only
in terms of equality and less than. In C++98 that made no difference for
reasonable code, because when the underlying operators are the same type
they are required to support all comparisons anyway.

But since LWG 280 it's possible to compare reverse_iterator<X> and
reverse_iterator<Y>, and comparisons between X and Y might not support
the full set of equality and relational operators. This means that it
matters whether we implement operator!= as x.base() != y.base() or
!(x.base() == y.base()), and the current implementation is
non-conforming.

This was already fixed in GCC 10.1 for C++20, this change also fixes it
for all other -std modes.

	PR libstdc++/94354
	* include/bits/stl_iterator.h (reverse_iterator): Fix comparison
	operators to use the correct operations on the underlying
	iterators.
	* testsuite/24_iterators/reverse_iterator/rel_ops.cc: New test.
2020-05-27 21:58:56 +01:00
Jonathan Wakely
116e3cfc7b libstdc++: Add new testcase for comparison category types
Comparing a comparison category type to anything except a literal 0 is
undefined. This verifies that at least some misuses are diagnosed at
compile time.

	* testsuite/18_support/comparisons/categories/zero_neg.cc: New test.
2020-05-27 13:14:17 +01:00
Patrick Palka
3bf5e7657b libstdc++: Fix common_iterator::operator-> [PR95322]
This patch fixes the definition of common_iterator::operator-> when the
underlying iterator's operator* returns a non-reference.

The first problem is that the class __detail::_Common_iter_proxy is used
unqualified.  Fixing that revealed another problem: the class's template
friend declaration of common_iterator doesn't match up with the
definition of common_iterator, because the friend declaration isn't
constrained.

If we try to make the friend declaration match up by adding constraints,
we run into frontend bug PR93467.  So we currently can't correctly
express this friend relation between __detail::_Common_iter_proxy and
common_iterator.

As a workaround to this frontend bug, this patch moves the definition of
_Common_iter_proxy into the class template of common_iterator so that we
could instead express the friend relation via the injected-class-name.

(This bug was found when attempting to use views::common to work around
the compile failure with the testcase in PR95322.)

libstdc++-v3/ChangeLog:

	PR libstdc++/95322
	* include/bits/stl_iterator.h (__detail::_Common_iter_proxy):
	Remove and instead define it ...
	(common_iterator::_Proxy): ... here.
	(common_iterator::operator->): Use it.
	* testsuite/24_iterators/common_iterator/2.cc: New test.
	* testsuite/std/ranges/adaptors/95322.cc: New test.
2020-05-26 16:17:34 -04:00
Patrick Palka
a57aa11191 libstdc++: Compile PR93978 testcase with -Wall
Now that the frontend issue PR c++/94038 is thoroughly fixed, the
testcase for PR93978 no longer fails to compile with -O -Wall, so add
-Wall to the testcase's compile flags to help ensure we don't regress
here.

libstdc++-v3/ChangeLog:

	PR libstdc++/93978
	* testsuite/std/ranges/adaptors/93978.cc: Add -Wall to
	dg-additional-options.  Avoid unused-but-set-variable warning.
2020-05-23 15:25:40 -04:00
Jonathan Wakely
3cb0c7cc16 libstdc++: Fix function that can't be constexpr in C++11 (PR 95289)
The body of this function isn't just a return statement, so it can't be
constexpr until C++14.

	PR libstdc++/95289
	* include/debug/helper_functions.h (__get_distance): Only declare
	as a constexpr function for C++14 and up.
	* testsuite/25_algorithms/copy/debug/95289.cc: New test.
2020-05-23 18:27:35 +01:00
Jonathan Wakely
988b853f9c libstdc++: Simplify filesystem::path SFINAE constraints
This replaces the filesystem::__detail::_Path SFINAE helper with two
separate helpers, _Path and _Path2. This avoids having one helper which
tries to check two different sets of requirements.

The _Path helper now uses variable templates instead of a set of
overloaded functions to detect specializations of basic_string or
basic_string_view.

The __not_<is_void<remove_pointer_t<_Tp1>> check is not necessary in
C++20 because iterator_traits<void*> is now empty. For C++17 replace
that check with a __safe_iterator_traits helper with partial
specializations for void pointers.

Finally, the __is_encoded_char check no longer uses remove_const_t,
which means that iterators with a const value_type will no longer be
accepted as arguments for path creation. Such iterators resulted in
undefined behaviour anyway, so it's still conforming to reject them in
the constraint checks.

	* include/bits/fs_path.h (filesystem::__detail::__is_encoded_char):
	Replace alias template with variable template. Don't remove const.
	(filesystem::__detail::__is_path_src): Replace overloaded function
	template with variable template and specializations.
	(filesystem::__detail::__is_path_iter_src): Replace alias template
	with class template.
	(filesystem::__detail::_Path): Use __is_path_src. Remove support for
	iterator pairs.
	(filesystem::__detail::_Path2): New alias template for checking
	InputIterator requirements.
	(filesystem::__detail::__constructible_from): Remove.
	(filesystem::path): Replace _Path<Iter, Iter> with _Path2<Iter>.
	* testsuite/27_io/filesystem/path/construct/80762.cc: Check with two
	constructor arguments of void and void* types.
2020-05-23 09:40:16 +01:00
Matthias Kretz
bc7a4f2f9e libstdc++: Enable simple invocation of runtest in testsuite
2020-05-21  Matthias Kretz  <kretz@kde.org>

	* testsuite/Makefile.am: Remove dup target_triplet and set tool,
	allowing runtest to work without arguments.
	* testsuite/Makefile.in: Regenerate.

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
2020-05-21 14:16:19 +01:00
Jonathan Wakely
f094665d46 libstdc++: Avoid constraint recursion with iterator_traits (PR 93983)
Checking whether a filesystem::path constructor argument is an iterator
requires instantiating std::iterator_traits. In C++20 that checks for
satisfaction of std::iterator_traits constraints, which checks if the
type is copyable, which can end up recursing back to the path
constructor. The fix in LWG 3420 is to reorder the cpp17-iterator
concept's constraints to check if the type looks vaguely like an
iterator before checking copyable. That avoids the recursion for types
which definitely aren't iterators, but isn't foolproof.

	PR libstdc++/93983
	* include/bits/iterator_concepts.h (__detail::__cpp17_iterator):
	Reorder constraints to avoid recursion when constructors use
	iterator_traits (LWG 3420).
	* testsuite/24_iterators/customization_points/lwg3420.cc: New test.
2020-05-21 07:32:15 +01:00
Jonathan Wakely
d9d34449bb libstdc++: Fix net::basic_socket::close(error_code&)
Also add some missing member functions, nodiscard attributes, and
noexcept-specifiers.

	* include/experimental/executor (use_future_t::use_future_t()): Fix
	incorrect noexcept-specifier.
	* include/experimental/internet (basic_resolver_results): Adjust
	whitespace.
	* include/experimental/socket (__basic_socket_impl::release): Add
	member function.
	(basic_socket(io_context&, const endpoint_type&)): Fix argument to
	target constructor.
	(basic_socket::release(), basic_socket::release(error_code&)): Add
	missing member functions.
	(basic_socket::is_open()): Add nodiscard attribute.
	(basic_socket::close(error_code&)): Pass argument to base function.
	(basic_socket_acceptor::release())
	(basic_socket_acceptor::release(error_code&)): Add missing member
	functions.
	(basic_socket_acceptor::is_open()): Add nodiscard attribute.
	(basic_socket_streambuf::error()): Add noexcept.
	(basic_socket_iostream::error()): Likewise.
	* testsuite/experimental/net/socket/basic_socket.cc: New test.
2020-05-21 00:59:55 +01:00
Jonathan Wakely
a2d196e75c libstdc++: Use RDRAND as fallback if RDSEED keeps failing (PR 94087)
It's not difficult for multiple threads to drain the entropy available
to the RDSEED instruction, at which point we throw an exception. This
change will try to use RDRAND after RDSEED fails repeatedly, and only
throw if RDRAND also fails repeatedly. This doesn't guarantee a random
value can always be read, but reduces the likelihood of failure when
using the RDSEED instruction.

	PR libstdc++/94087
	* src/c++11/random.cc (__x86_rdseed): Allow fallback function to be
	passed in.
	(__x86_rdseed_rdrand): New function that uses rdseed with rdrand
	fallback.
	(random_device::_M_init): Use __x86_rdseed_rdrand when both
	instructions are available.
	* testsuite/26_numerics/random/random_device/94087.cc: New test.
2020-05-19 23:04:45 +01:00
Patrick Palka
864fed4a49 c++: Explain fn template argument type/value mismatches [PR66439]
In fn_type_unifcation, we are passing NULL_TREE as the 'in_decl'
parameter to coerce_template_parms, and this is causing template
type/value mismatch error messages to get suppressed regardless of the
value of 'complain'.

This means that when substitution into a function template fails due to
a type/value mismatch between a template parameter and the provided
template argument, we just say "template argument deduction/substitution
failed:" without a followup explanation of the failure.

Fix this by passing 'fn' instead of NULL_TREE to coerce_template_parms.

gcc/cp/ChangeLog:

	PR c++/66439
	* pt.c (fn_type_unification): Pass 'fn' instead of NULL_TREE as
	the 'in_decl' parameter to coerce_template_parms.

gcc/testsuite/ChangeLog:

	PR c++/66439
	* g++.dg/cpp2a/concepts-ts4.C: Expect a "type/value mismatch"
	diagnostic.
	* g++.dg/cpp2a/concepts-ts6.C: Likewise.
	* g++.dg/template/error56.C: Likewise.
	* g++.dg/template/error59.C: New test.

libstdc++-v3/ChangeLog:

	PR c++/66439
	* testsuite/20_util/pair/astuple/get_neg.cc: Prune "type/value
	mismatch" messages.
	* testsuite/20_util/tuple/element_access/get_neg.cc: Likewise.
2020-05-18 23:50:14 -04:00
Alexandre Oliva
883246530f x86-vxworks malloc aligns to 8 bytes like solaris
Vxworks 7's malloc, like Solaris', only ensures 8-byte alignment of
returned pointers on 32-bit x86, though GCC's stddef.h defines
max_align_t with 16-byte alignment for __float128.  This patch enables
on x86-vxworks the same memory_resource workaround used for x86-solaris.

The testsuite also had a workaround, defining BAD_MAX_ALIGN_T and
xfailing the test; extend those to x86-vxworks as well, and remove the
check for char-aligned requested allocation to be aligned like
max_align_t.  With that change, the test passes on x86-vxworks; I'm
guessing that's the same reason for the test not to pass on
x86-solaris (and on x86_64-solaris -m32), so with the fix, I'm
tentatively removing the xfail.


for libstdc++-v3/ChangeLog

	PR libstdc++/77691
	* include/experimental/memory_resource
	(__resource_adaptor_imp::do_allocate): Handle max_align_t on
	x86-vxworks as on x86-solaris.
	(__resource_adaptor_imp::do_deallocate): Likewise.
	* testsuite/experimental/memory_resource/new_delete_resource.cc:
	Drop xfail.
	(BAD_MAX_ALIGN_T): Define on x86-vxworks as on x86-solaris.
	(test03): Drop max-align test for char-aligned alloc.
2020-05-13 04:49:00 -03:00
Ulrich Drepper
7a2e715c9a Actually comment the new tests 2020-05-12 07:38:28 +02:00
François Dumont
72a54e5e81 libstdc++ std::fill overload for std::vector<bool>::iterator
Extend the overload so that it is used even when _GLIBCXX_DEBUG mode
is activated.

	* include/bits/stl_algobase.h (struct _Bit_iterator): New declaration.
	(std::__fill_a1(_Bit_iterator, _Bit_iterator, const bool&)): Likewise.
	* include/bits/stl_bvector.h (__fill_bvector): Move outside
	_GLIBCXX_STD_C namespace.
	(fill(_Bit_iterator, _Bit_iterator, const bool&)): Likewise and rename
	into...
	(__fill_a1): ...this.
	* testsuite/25_algorithms/fill/bvector/1.cc: New.
2020-05-06 23:28:22 +02:00
Jonathan Wakely
ec40967f13 libstdc++: Make pmr::synchronized_pool_resource work without libpthread (PR 94936)
I implicitly assumed that programs using pmr::synchronized_pool_resource
would also be using multiple threads, and so the weak symbols in
gthr-posix.h would be resolved by linking to libpthread. If that isn't
true then it crashes when trying to use pthread_key_create.

This commit makes the pool resource check __gthread_active_p() before
using thread-specific data, and just use a single set of memory pools
when there's only a single thread.

	PR libstdc++/94936
	* src/c++17/memory_resource.cc (synchronized_pool_resource::_TPools):
	Add comment about single-threaded behaviour.
	(synchronized_pool_resource::_TPools::move_nonempty_chunks()): Hoist
	class member access out of loop.
	(synchronized_pool_resource::synchronized_pool_resource())
	(synchronized_pool_resource::~synchronized_pool_resource())
	(synchronized_pool_resource::release()): Check __gthread_active_p
	before creating and/or deleting the thread-specific data key.
	(synchronized_pool_resource::_M_thread_specific_pools()): Adjust
	assertions.
	(synchronized_pool_resource::do_allocate(size_t, size_t)): Add fast
	path for single-threaded case.
	(synchronized_pool_resource::do_deallocate(void*, size_t, size_t)):
	Likewise. Return if unable to find a pool that owns the allocation.
	* testsuite/20_util/synchronized_pool_resource/allocate_single.cc:
	New test.
	* testsuite/20_util/synchronized_pool_resource/cons_single.cc: New
	test.
	* testsuite/20_util/synchronized_pool_resource/release_single.cc: New
	test.
2020-05-04 13:37:31 +01:00
Jonathan Wakely
22b6b5d6cf libstdc++: Make byte-sized std::fill_n a constant expression (PR 94933)
The overload for byte types uses memset and isn't constexpr. This adds
the specifier and uses std::is_constant_evaluated() to provide a
compile-time alternative.

	PR libstdc++/94933
	* include/bits/stl_algobase.h (__fill_a1): Make overload for byte types
	usable in constant expressions.
	* testsuite/25_algorithms/fill_n/constexpr.cc: Test with bytes and
	non-scalars.
2020-05-03 13:33:15 +01:00
Jonathan Wakely
187c854cc6 libstdc++: Add more tests for _E10, _E11 etc. (PR 94901)
PR libstdc++/94901
	* testsuite/17_intro/badnames.cc: Test values between _E9 and _E24 too.
2020-05-01 14:49:48 +01:00
Jonathan Wakely
a5f2fb1ff1 libstdc++: Replace deduced return type in ranges::iter_move (PR 92894)
The deduced return type causes the instantiation of the function body,
which can then require the instantiation of std::projected::operator*
which is intentionally not defined.

This patch uses a helper trait to define the return type, so that the
function body doesn't need to be instantiated. That helper trait can
then also be used in other places that currently check the return type
of ranges::iter_move (iter_rvalue_reference_t and indirectly_readable).

2020-05-01  Jonathan Wakely  <jwakely@redhat.com>
	    Patrick Palka  <ppalka@redhat.com>

	PR libstdc++/92894
	* include/bits/iterator_concepts.h (ranges::__cust_imove::_IMove):
	Add trait to determine return type and an alias for it.
	(ranges::__cust_imove::_IMove::operator()): Use __result instead of
	deduced return type.
	(iter_rvalue_reference_t): Use _IMove::__type instead of checking
	the result of ranges::iter_move.
	(__detail::__indirectly_readable_impl): Use iter_rvalue_reference_t
	instead of checking the result of ranges::iter_move.
	* testsuite/24_iterators/customization_points/92894.cc: New test.
	* testsuite/24_iterators/indirect_callable/92894.cc: New test.
2020-05-01 14:27:25 +01:00
Jonathan Wakely
070b4df8a0 libstdc++: Replace reserved identifier _T with _Tp (PR 94901)
The libstdc++ manual documents that _T can not be used, because it's a
macro in system headers on some targets.

	PR libstdc++/94901
	* include/std/type_traits (__is_complete_or_unbounded): Replace
	BADNAME _T with _Tp.
	* testsuite/17_intro/badnames.cc: New test.
2020-05-01 13:41:02 +01:00
Jonathan Wakely
b1983f4582 libstdc++: Avoid errors in allocator's noexcept-specifier (PR 89510)
This fixes a regression due to the conditional noexcept-specifier on
std::allocator::construct and std::allocator::destroy, as well as the
corresponding members of new_allocator, malloc_allocator, and
allocator_traits. Those noexcept-specifiers were using expressions which
might be ill-formed, which caused errors outside the immediate context
when checking for the presence of construct and destroy in SFINAE
contexts.

The fix is to use the is_nothrow_constructible and
is_nothrow_destructible type traits instead, because those traits are
safe to use even when the construction/destruction itself is not valid.

The is_nothrow_constructible trait will be false for a type that is not
also nothrow-destructible, even if the new-expression used in the
construct function body is actually noexcept. That's not the correct
answer, but isn't a problem because providing a noexcept-specifier on
these functions is not required by the standard anyway. If the answer is
false when it should be true, that's suboptimal but OK (unlike giving
errors for valid code, or giving a true answer when it should be false).

	PR libstdc++/89510
	* include/bits/alloc_traits.h (allocator_traits::_S_construct)
	(allocator_traits::_S_destroy)
	(allocator_traits<allocator<T>>::construct): Use traits in
	noexcept-specifiers.
	* include/bits/allocator.h (allocator<void>::construct)
	(allocator<void>::destroy): Likewise.
	* include/ext/malloc_allocator.h (malloc_allocator::construct)
	(malloc_allocator::destroy): Likewise.
	* include/ext/new_allocator.h (new_allocator::construct)
	(new_allocator::destroy): Likewise.
	* testsuite/20_util/allocator/89510.cc: New test.
	* testsuite/ext/malloc_allocator/89510.cc: New test.
	* testsuite/ext/new_allocator/89510.cc: New test.
2020-04-30 16:01:43 +01:00
Jonathan Wakely
d0330a0360 libstdc++: Fixes for feature test macros (PR 91480)
Remove the non-standard __cpp_lib_allocator_is_always_equal macro and
add the missing macros for P1032R1.

	PR libstdc++/91480
	* include/bits/allocator.h (__cpp_lib_allocator_is_always_equal):
	Remove non-standard macro.
	* include/bits/stl_iterator.h (__cpp_lib_constexpr_iterator): Define
	to indicate P1032R1 support.
	* include/bits/stl_pair.h (__cpp_lib_constexpr_utility): Likewise.
	* include/std/string_view (__cpp_lib_constexpr_string_view): Likewise.
	* include/std/tuple (__cpp_lib_constexpr_tuple): Likewise.
	* include/std/version (__cpp_lib_allocator_is_always_equal): Remove.
	(__cpp_lib_constexpr_iterator, __cpp_lib_constexpr_string_view)
	(__cpp_lib_constexpr_tuple, __cpp_lib_constexpr_utility): Define.
	* testsuite/20_util/function_objects/constexpr_searcher.cc: Check
	feature test macro.
	* testsuite/20_util/tuple/cons/constexpr_allocator_arg_t.cc: Likewise.
	* testsuite/21_strings/basic_string_view/operations/copy/char/
	constexpr.cc: Likewise.
	* testsuite/24_iterators/insert_iterator/constexpr.cc: Likewise.
2020-04-28 23:40:18 +01:00
Jonathan Wakely
162c40a4c1 libstdc++: Fix regression in std::_Construct (PR 94831)
By trying to reuse the existing std::_Construct function as a wrapper
for std::construct_at I introduced regressions, because changing
std::_Construct to return non-void made it ill-formed for array types.

The solution is to revert _Construct to its former state, and change
allocator_traits::construct to explicitly call construct_at instead.
This decouples all the existing callers of _Construct from the new
construct_at requirements.

	PR libstdc++/94831
	* include/bits/alloc_traits.h (_S_construct): Restore placement
	new-expression for C++11/14/17 and call std::construct_at directly
	for C++20.
	* include/bits/stl_construct.h (_Construct): Revert to non-constexpr
	function returning void.
	* testsuite/20_util/specialized_algorithms/
	uninitialized_value_construct/94831.cc: New test.
	* testsuite/23_containers/vector/cons/94831.cc: New test.
2020-04-28 23:39:38 +01:00
Patrick Palka
19667c82e4 libstdc++: Fix subrange::advance and subrange::prev (LWG 3433)
This implements the proposed resolution of LWG 3433, which fixes
subrange::advance when called with a negative argument.

libstdc++-v3/ChangeLog:

	LWG 3433 subrange::advance(n) has UB when n < 0
	* include/std/ranges (subrange::prev): Fix typo.
	(subrange::advance): Handle a negative argument as per the proposed
	resolution of LWG 3433.
	* testsuite/std/ranges/subrange/lwg3433.cc: New test.
2020-04-28 16:43:23 -04:00
Jonathan Wakely
00082ff88c libstdc++: Make net::service_already_exists default constructible
The LWG issue I created is Tentatively Ready and proposes to declare a
public default constructor, rather than the private one I added
recently.

	* include/experimental/executor (service_already_exists): Make default
	constructor public (LWG 3414).
	* testsuite/experimental/net/execution_context/make_service.cc: Check
	the service_already_exists can be default constructed.
2020-04-24 14:15:51 +01:00
Jonathan Wakely
d1462b0782 libstdc++: Fix constructor constraints for std::any (PR 90415)
This removes a non-standard extension to std::any which causes errors
for valid code, due to recursive instantiation of a trait that isn't
supposed to be in the constraints.

It also removes some incorrect constraints on the in_place_type<T>
constructors and emplace members, which were preventing creating a
std::any object with another std::any as the contained value.

2020-04-24  Kamlesh Kumar  <kamleshbhalui@gmail.com>
	    Jonathan Wakely  <jwakely@redhat.com>

	PR libstdc++/90415
	PR libstdc++/92156
	* include/std/any (any): Rename template parameters for consistency
	with the standard.
	(any::_Decay): Rename to _Decay_if_not_any.
	(any::any(T&&):: Remove is_constructible from constraints. Remove
	non-standard overload.
	(any::any(in_place_type_t<T>, Args&&...))
	(any::any(in_place_type_t<T>, initializer_list<U>, Args&&...))
	(any::emplace(Args&&...))
	(any::emplace(initializer_list<U>, Args&&...)):
	Use decay_t instead of _Decay.
	* testsuite/20_util/any/cons/90415.cc: New test.
	* testsuite/20_util/any/cons/92156.cc: New Test.
	* testsuite/20_util/any/misc/any_cast_neg.cc: Make dg-error directives
	more robust.
	* testsuite/20_util/any/modifiers/92156.cc: New test.
2020-04-24 00:54:20 +01:00
Thomas Rodgers
8c9d69bafc libstdc++: Mark experimental::net::system_context ctor deleted
* include/experimental/net/executor (system_context): Mark
           system_context::system_context() = delete.
           * testsuite/experimental/net/executor/1.cc: Add new
           test to check system_context is not default constructible.
2020-04-23 13:44:23 -07:00
Jonathan Wakely
40541efe1c libstdc++: Change __cpp_lib_array_constexpr for C++17 again
This partially reverts my previous change related to this macro. The
C++20 constexpr iterator requirements are always met by array:iterator,
because it's just a pointer. So the macro can be set to 201803 even in
C++17 mode.

	* include/bits/stl_iterator.h (__cpp_lib_array_constexpr): Revert
	value for C++17 to 201803L because P0858R0 is supported for C++17.
	* include/std/version (__cpp_lib_array_constexpr): Likewise.
	* testsuite/23_containers/array/element_access/constexpr_c++17.cc:
	Check for value corresponding to P0031R0 features being tested.
	* testsuite/23_containers/array/requirements/constexpr_iter.cc:
	Check for value corresponding to P0858R0 features being tested.
2020-04-23 21:39:33 +01:00
Jonathan Wakely
aac39307e8 libstdc++: Define __cpp_lib_execution feature test macro
This macro has never been defined by libstdc++, despite supporting the
parallel algorithms. It should have a different value for C++17 and
C++20, because P1001R2 should not be supported in C++17, but
unsequenced_policy is defined for C++17 (see PR p4702).

	* include/std/execution (__cpp_lib_execution): Define to indicate
	support for P0024R2 and P1001R2.
	* include/std/version (__cpp_lib_execution): Define.
	* testsuite/25_algorithms/pstl/feature_test.cc: Only test macro
	defined by <algorithm>, move other tests to new tests ...
	* testsuite/25_algorithms/pstl/feature_test-2.cc: New test.
	* testsuite/25_algorithms/pstl/feature_test-3.cc: New test.
	* testsuite/25_algorithms/pstl/feature_test-4.cc: New test.
	* testsuite/25_algorithms/pstl/feature_test-5.cc: New test.
2020-04-22 22:54:35 +01:00