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.
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.
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.
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.
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.
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.
With PR c++/92078 and PR c++/92103 both fixed, nested class templates
can now be constrained. That means a number of namespace-scope helpers
can be moved to the class scope, so they're only visible where they're
needed.
* include/bits/iterator_concepts.h (__detail::__ptr, __detail::__ref)
(__detail::__cat, __detail::__diff): Move to class scope in the
relevant __iterator_traits specializations.
(__iterator_traits<>): Use nested class templates instead of ones from
namespace __detail.
* include/bits/stl_iterator.h (__detail::__common_iter_ptr): Move to
class scope in iterator_traits<common_iterator<I, S>>.
(iterator_traits<common_iterator<I, S>>): Use nested class template
instead of __detail::__common_iter_ptr.
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.
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.
When I refactored filesystem::path string conversions in
r11-587-584d52b088f9fcf78704b504c3f1f07e17c1cded I failed to update the
mingw-specific code in filesystem::u8path, causing a bootstrap failure.
This fixes it, and further refactors the mingw-specific code along the
same lines as the previous commit. All conversions from UTF-8 strings to
wide strings now use the same helper function, __wstr_from_utf8.
PR libstdc++/95392
* include/bits/fs_path.h (path::_S_to_string): Move to
namespace-scope and rename to ...
(__detail::__string_from_range): ... this.
[WINDOWS] (__detail::__wstr_from_utf8): New function template to
convert a char sequence containing UTF-8 to wstring.
(path::_S_convert(Iter, Iter)): Adjust call to _S_to_string.
(path::_S_convert_loc(Iter, Iter, const locale&)): Likewise.
(u8path(InputIterator, InputIterator)) [WINDOWS]: Use
__string_from_range to obtain a contiguous range and
__wstr_from_utf8 to obtain a wide string.
(u8path(const Source&)) [WINDOWS]: Use __effective_range to
obtain a contiguous range and __wstr_from_utf8 to obtain a wide
string.
(path::_S_convert(const _EcharT*, const _EcharT)) [WINDOWS]:
Use __wstr_from_utf8.
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.
The <xref> element creates the link text automatically from the link
target, rather than using the text node child of the element. This can
be changed by using an endterm attribute, but it's simpler to just use
the <link> element instead.
* doc/xml/manual/containers.xml: Replace <xref> with <link>.
* doc/xml/manual/evolution.xml: Likewise.
* doc/html/manual/api.html: Regenerate.
* doc/html/manual/containers.html: Regenerate.
There is a stray change (introducing a bogus line at the top) that
came via 2babbb6760c43bcd803a5e168ef5ecb0be8a5121; remove that again.
* doc/xml/manual/policy_data_structures_biblio.xml: Remove
stray change.
Use the GLIBCXX_CHECK_MATH_DECL macro to check for the full list of
vxworks math decls.
libstdc++-v3/ChangeLog
* crossconfig.m4 (<*-vxworks>): Check for more math decls.
* configure: Rebuild.
Those methods are making a double lookup in case of insertion, they can
perform only one.
PR libstdc++/95079
* include/bits/hashtable_policy.h (_Insert_base<>::try_emplace): New.
* include/bits/unordered_map.h (unordered_map<>::try_emplace): Adapt.
(unordered_map<>::insert_or_assign): Adapt.
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.
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.
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.
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.
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.
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.
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.
This simplifies the logic of converting Source arguments and pairs of
InputIterator arguments into the native string format. For any input
that is a contiguous range of path::value_type (or char8_t for POSIX)
a string view can be created and the conversion can be done directly,
with no intermediate allocation. Previously some cases created a
basic_string unnecessarily, for example construction from a pair of
path::string_type::iterators, or a pair of non-const value_type*
pointers.
* include/bits/fs_path.h (__detail::_S_range_begin)
(__detail::_S_range_end, path::_S_string_from_iter): Replace with
overloaded function template __detail::__effective_range.
(__detail::__effective_range): New overloaded function template to
create a basic_string or basic_string_view for an effective range.
(__detail::__value_type_is_char): Use __detail::__effective_range.
Do not use remove_const on value type.
(__detail::__value_type_is_char_or_char8_t): Likewise.
(path::path(const Source&, format))
(path::path(const Source&, const locale&))
(path::operator/=(const Source&), path::append(const Source&))
(path::concat(const Source&)): Use __detail::__effective_range.
(path::_S_to_string(InputIterator, InputIterator)): New function
template to create a string view if possible, or string otherwise.
(path::_S_convert): Add overloads that convert a string returned
by __detail::__effective_range. Use if-constexpr to inline conversion
logic from all overloads of _Cvt::_S_convert.
(path::_S_convert_loc): Add overload that converts a string. Use
_S_to_string to avoid allocation when possible.
(path::_Cvt): Remove.
(path::operator+=(CharT)): Remove indirection through path::concat.
* include/experimental/bits/fs_path.h (path::_S_convert_loc): Add
overload for non-const pointers, to avoid constructing a std::string.
* src/c++17/fs_path.cc (path::_S_convert_loc): Replace conditional
compilation with call to _S_convert.
These functions were originally static members of the path class, but
the 'static' specifiers were not removed when they were moved to
namespace scope. This causes ODR violations when the functions are
called from functions defined in the header, which is incompatible with
Nathan's modules branch. Change them to 'inline' instead.
* include/bits/fs_path.h (__detail::_S_range_begin)
(__detail::_S_range_end): Remove unintentional static specifiers.
* include/experimental/bits/fs_path.h (__detail::_S_range_begin)
(__detail::_S_range_end): Likewise.
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.
2020-05-21 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>
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.
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.
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.
