This rewrites ranges::minmax and ranges::minmax_element so that it
performs at most 3*N/2 many comparisons, as required by the standard.
In passing, this also fixes PR100387 by avoiding a premature std::move
in ranges::minmax and in std::shift_right.
PR libstdc++/100387
libstdc++-v3/ChangeLog:
* include/bits/ranges_algo.h (__minmax_fn::operator()): Rewrite
to limit comparison complexity to 3*N/2.
(__minmax_element_fn::operator()): Likewise.
(shift_right): Avoid premature std::move of __result.
* testsuite/25_algorithms/minmax/constrained.cc (test04, test05):
New tests.
* testsuite/25_algorithms/minmax_element/constrained.cc (test02):
Likewise.
These tests rely on ADL for some functions, probably unintentionally.
The calls only work because the iterator wrappers derive from
std::iterator and so namespace std is an associated namespace.
libstdc++-v3/ChangeLog:
* testsuite/25_algorithms/inplace_merge/constrained.cc: Qualify
call to ranges::next.
* testsuite/25_algorithms/is_sorted/constrained.cc: Likewise.
* testsuite/25_algorithms/is_sorted_until/constrained.cc:
Likewise.
* testsuite/25_algorithms/swap_ranges/1.cc: Qualify call to
swap_ranges.
libstdc++-v3/ChangeLog:
* testsuite/25_algorithms/pstl/alg_nonmodifying/find_end.cc:
Increase dg-timeout-factor to 4. Fix -Wunused-parameter
warnings. Replace bitwise AND with logical AND in loop
condition.
* testsuite/25_algorithms/pstl/alg_nonmodifying/search_n.cc:
Replace bitwise AND with logical AND in loop condition.
* testsuite/util/pstl/test_utils.h: Remove unused parameter
names.
The header synopsis test fails to define NOTHROW for C++98.
The shared_ptr test should be skipped for C++98.
The debug mode one should work for C++98 too, it just needs to avoid
C++11 syntax that isn't valid in C++98.
libstdc++-v3/ChangeLog:
* testsuite/20_util/headers/memory/synopsis.cc: Define C++98
alternative for macro.
* testsuite/20_util/shared_ptr/creation/99006.cc: Add effective
target keyword.
* testsuite/25_algorithms/copy/debug/99402.cc: Avoid C++11
syntax.
The message used for static assertions should be phrased so that it's
unambiguous whether the condition should be true or false. The message
should definitely not state the negative condition.
libstdc++-v3/ChangeLog:
* include/bits/stl_algobase.h (__copy_move, __copy_move_backward):
Improve static_assert messages.
* testsuite/25_algorithms/copy/58982.cc: Adjust expected output.
* testsuite/25_algorithms/copy_n/58982.cc: Likewise.
Fix some test bugs found by ubsan.
libstdc++-v3/ChangeLog:
* testsuite/20_util/from_chars/3.cc: Use unsigned type to avoid
overflow.
* testsuite/24_iterators/reverse_iterator/2.cc: Do not add
non-zero value to null pointer.
* testsuite/25_algorithms/copy_backward/move_iterators/69478.cc:
Use past-the-end iterator for result.
* testsuite/25_algorithms/move_backward/69478.cc: Likewise.
* testsuite/25_algorithms/move_backward/93872.cc: Likewise.
__dp_sign precision indicates that we found out what iterator comes first or
last in the range. __dp_sign_max_size is the same plus it gives the information
of the max size of the range that is to say the max_size value such that
distance(lhs, rhs) < max_size.
Thanks to this additional information we are able to tell when a copy of n elements
to that range will fail even if we do not know exactly how large it is.
This patch makes sure that we are properly using this information.
libstdc++-v3/ChangeLog:
PR libstdc++/99402
* include/debug/helper_functions.h (__can_advance(_InputIterator,
const std::pair<_Diff, _Distance_precision>&, int)): New.
(__can_advance(const _Safe_iterator<>&,
const std::pair<_Diff, _Distance_precision>&, int)): New.
* include/debug/macros.h (__glibcxx_check_can_increment_dist): New,
use latter.
(__glibcxx_check_can_increment_range): Adapt to use latter.
(__glibcxx_check_can_decrement_range): Likewise.
* include/debug/safe_iterator.h
(_Safe_iterator<>::_M_can_advance(const std::pair<_Diff, _Distance_precision>&,
int)): New.
(__can_advance(const _Safe_iterator<>&,
const std::pair<_Diff, _Distance_precision>&, int)): New.
* include/debug/safe_iterator.tcc
(_Safe_iterator<>::_M_can_advance(const std::pair<_Diff, _Distance_precision>&,
int)): New.
(_Safe_iterator<>::_M_valid_range(const _Safe_iterator<>&,
std::pair<difference_type, _Distance_precision>&, bool)): Adapt for
__dp_sign_max_size.
(__copy_move_a): Adapt to use __glibcxx_check_can_increment_dist.
(__copy_move_backward_a): Likewise.
(__equal_aux): Likewise.
* include/debug/stl_iterator.h (__can_advance(const std::reverse_iterator<>&,
const std::pair<_Diff, _Distance_precision>&, int)): New.
(__can_advance(const std::move_iterator<>&,
const std::pair<_Diff, _Distance_precision>&, int)): New.
* testsuite/25_algorithms/copy/debug/99402.cc: New test.
These tests FAIL when testing debug mode with a small tool_timeout
value. Give them a longer relative timeout.
libstdc++-v3/ChangeLog:
* testsuite/25_algorithms/lexicographical_compare/deque_iterators/1.cc:
Add dg-timeout-factor directive.
* testsuite/ext/pb_ds/regression/tree_map_rand_debug.cc:
Increase timeout factor from 2.0 to 3.0.
* testsuite/ext/pb_ds/regression/tree_set_rand_debug.cc:
Likewise.
* testsuite/lib/libstdc++.exp (check_effective_target_debug-mode):
Define "debug-mode" as an effective-target keyword.
The __glibcxx_check_can_[increment|decrement]_range macros are using the
_GLIBCXX_DEBUG_VERIFY_COND_AT macro which is not constexpr compliant and will produce nasty
diagnostics rather than the std::__failed_assertion dedicated to constexpr. Replace it with
correct _GLIBCXX_DEBUG_VERIFY_AT_F.
libstdc++-v3/ChangeLog:
* include/debug/macros.h (__glibcxx_check_can_increment_range): Replace
_GLIBCXX_DEBUG_VERIFY_COND_AT usage with _GLIBCXX_DEBUG_VERIFY_AT_F.
(__glibcxx_check_can_decrement_range): Likewise.
* testsuite/25_algorithms/copy_backward/constexpr.cc (test03): New.
* testsuite/25_algorithms/copy/debug/constexpr_neg.cc: New test.
* testsuite/25_algorithms/copy_backward/debug/constexpr_neg.cc: New test.
* testsuite/25_algorithms/equal/constexpr_neg.cc: New test.
* testsuite/25_algorithms/equal/debug/constexpr_neg.cc: New test.
As in r11-5449, this adds a muliplier to the timeout for slow tests.
This covers the majority of the <regex> and PSTL tests.
libstdc++-v3/ChangeLog:
* testsuite/20_util/specialized_algorithms/pstl/*: Add
dg-timeout-factor.
* testsuite/25_algorithms/pstl/*: Likewise.
* testsuite/26_numerics/pstl/*: Likewise.
* testsuite/28_regex/*: Likewise.
Reduce memory allocation in stable_sort/inplace_merge algorithms to what is needed
by the implementation.
Co-authored-by: John Chang <john.chang@samba.tv>
libstdc++-v3/ChangeLog:
PR libstdc++/83938
* include/bits/stl_tempbuf.h (get_temporary_buffer): Change __len
computation in the loop to avoid truncation.
* include/bits/stl_algo.h:
(__inplace_merge): Take temporary buffer length from smallest range.
(__stable_sort): Limit temporary buffer length.
* testsuite/25_algorithms/inplace_merge/1.cc (test4): New.
* testsuite/performance/25_algorithms/stable_sort.cc: Test stable_sort
under different heap memory conditions.
* testsuite/performance/25_algorithms/inplace_merge.cc: New test.
My ranges transcription of the std::search_n implementation for random
access iterators missed a crucial part of the algorithm which the
existing tests didn't exercise. When __remainder is less than __count
at the start of an iteration of the outer while loop, it means we're
continuing a partial match of __count - __remainder elements from the
previous iteration. If at the end of the iteration we don't complete
this partial match, we need to reset __remainder so that it's only
offset by the size of the most recent partial match before starting the
next iteration.
This patch fixes this appropriately, mirroring how it's done in the
corresponding std::search_n implementation.
libstdc++-v3/ChangeLog:
PR libstdc++/97828
* include/bits/ranges_algo.h (__search_n_fn::operator()): Check
random_access_iterator before using the backtracking
implementation. When the backwards scan fails prematurely,
reset __remainder appropriately.
* testsuite/25_algorithms/search_n/97828.cc: New test.
libstdc++-v3/ChangeLog:
* include/debug/assertions.h (__glibcxx_requires_non_empty_range):
Remove __builtin_expect.
(__glibcxx_requires_subscript): Likewise.
(__glibcxx_requires_nonempty): Likewise.
* include/debug/formatter.h (__check_singular): Add C++11 constexpr
qualification.
* include/debug/helper_functions.h (__check_singular): Likewise. Skip
check if constant evaluated.
(__valid_range): Do not skip check if constant evaluated.
* include/debug/macros.h (_GLIBCXX_DEBUG_VERIFY_COND_AT): Add
__builtin_expect.
(_GLIBCXX_DEBUG_VERIFY_AT_F): Use __glibcxx_assert_1.
* testsuite/21_strings/basic_string_view/element_access/char/back_constexpr_neg.cc:
New test.
* testsuite/21_strings/basic_string_view/element_access/char/constexpr.cc: New test.
* testsuite/21_strings/basic_string_view/element_access/char/constexpr_neg.cc: New test.
* testsuite/21_strings/basic_string_view/element_access/char/front_back_constexpr.cc:
New test.
* testsuite/21_strings/basic_string_view/element_access/char/front_constexpr_neg.cc:
New test.
* testsuite/21_strings/basic_string_view/element_access/wchar_t/back_constexpr_neg.cc:
New test.
* testsuite/21_strings/basic_string_view/element_access/wchar_t/constexpr.cc: New test.
* testsuite/21_strings/basic_string_view/element_access/wchar_t/constexpr_neg.cc: New test.
* testsuite/21_strings/basic_string_view/element_access/wchar_t/front_constexpr_neg.cc:
New test.
* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_neg.cc: New test.
* testsuite/25_algorithms/lower_bound/debug/constexpr_partitioned_pred_neg.cc: New test.
* testsuite/25_algorithms/lower_bound/debug/constexpr_valid_range_neg.cc: New test.
* testsuite/25_algorithms/lower_bound/debug/partitioned_neg.cc: New test.
* testsuite/25_algorithms/lower_bound/debug/partitioned_pred_neg.cc: New test.
* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_neg.cc: New test.
* testsuite/25_algorithms/upper_bound/debug/constexpr_partitioned_pred_neg.cc: New test.
* testsuite/25_algorithms/upper_bound/debug/constexpr_valid_range_neg.cc: New test.
* testsuite/25_algorithms/upper_bound/debug/partitioned_neg.cc: New test.
* testsuite/25_algorithms/upper_bound/debug/partitioned_pred_neg.cc: New test.
This patch implements the -Wvexing-parse warning to warn about the
sneaky most vexing parse rule in C++: the cases when a declaration
looks like a variable definition, but the C++ language requires it
to be interpreted as a function declaration. This warning is on by
default (like clang++). From the docs:
void f(double a) {
int i(); // extern int i (void);
int n(int(a)); // extern int n (int);
}
Another example:
struct S { S(int); };
void f(double a) {
S x(int(a)); // extern struct S x (int);
S y(int()); // extern struct S y (int (*) (void));
S z(); // extern struct S z (void);
}
You can find more on this in [dcl.ambig.res].
I spent a fair amount of time on fix-it hints so that GCC can recommend
various ways to resolve such an ambiguity. Sometimes that's tricky.
E.g., suggesting default-initialization when the class doesn't have
a default constructor would not be optimal. Suggesting {}-init is also
not trivial because it can use an initializer-list constructor if no
default constructor is available (which ()-init wouldn't do). And of
course, pre-C++11, we shouldn't be recommending {}-init at all.
I also uncovered a bug in cp_parser_declarator, where we were setting
*parenthesized_p to true despite the comment saying the exact opposite.
gcc/c-family/ChangeLog:
PR c++/25814
* c.opt (Wvexing-parse): New option.
gcc/cp/ChangeLog:
PR c++/25814
* cp-tree.h (enum cp_tree_index): Add CPTI_EXPLICIT_VOID_LIST.
(explicit_void_list_node): Define.
(PARENTHESIZED_LIST_P): New macro.
(struct cp_declarator): Add function::parens_loc.
* decl.c (cxx_init_decl_processing): Initialize explicit_void_list_node.
(grokparms): Also break when explicit_void_list_node.
* parser.c (make_call_declarator): New location_t parameter. Use it
to set declarator->u.function.parens_loc.
(cp_parser_lambda_declarator_opt): Pass UNKNOWN_LOCATION to
make_call_declarator.
(warn_about_ambiguous_parse): New function.
(cp_parser_init_declarator): Call warn_about_ambiguous_parse.
(cp_parser_declarator): Set *parenthesized_p to false rather than to
true.
(cp_parser_direct_declarator): Create a location for the function's
parentheses and pass it to make_call_declarator.
(cp_parser_parameter_declaration_clause): Return explicit_void_list_node
for (void).
(cp_parser_parameter_declaration_list): Set PARENTHESIZED_LIST_P
in the parameters tree.
gcc/ChangeLog:
PR c++/25814
* doc/invoke.texi: Document -Wvexing-parse.
gcc/testsuite/ChangeLog:
PR c++/25814
* g++.dg/cpp2a/fn-template16.C: Add a dg-warning.
* g++.dg/cpp2a/fn-template7.C: Likewise.
* g++.dg/lookup/pr80891-5.C: Likewise.
* g++.dg/lto/pr79050_0.C: Add extern.
* g++.dg/lto/pr84805_0.C: Likewise.
* g++.dg/parse/pr58898.C: Add a dg-warning.
* g++.dg/template/scope5.C: Likewise.
* g++.old-deja/g++.brendan/recurse.C: Likewise.
* g++.old-deja/g++.jason/template4.C: Likewise.
* g++.old-deja/g++.law/arm4.C: Likewise.
* g++.old-deja/g++.mike/for2.C: Likewise.
* g++.old-deja/g++.other/local4.C: Likewise.
* g++.old-deja/g++.pt/crash3.C: Likewise.
* g++.dg/warn/Wvexing-parse.C: New test.
* g++.dg/warn/Wvexing-parse2.C: New test.
* g++.dg/warn/Wvexing-parse3.C: New test.
* g++.dg/warn/Wvexing-parse4.C: New test.
* g++.dg/warn/Wvexing-parse5.C: New test.
* g++.dg/warn/Wvexing-parse6.C: New test.
* g++.dg/warn/Wvexing-parse7.C: New test.
libstdc++-v3/ChangeLog:
PR c++/25814
* testsuite/20_util/reference_wrapper/lwg2993.cc: Add a dg-warning.
* testsuite/25_algorithms/generate_n/87982_neg.cc: Likewise.
These tests just return true without checking that the results of the
algorithms. Although it should be safe to assume that the algorithms
behave the same at compile-time as at run-time, we can use these tests
to verify it.
This replaces each 'return true' statement with a condition that depends
on the basic functionality of the algorithm, such as returning an
iterator to the right position.
libstdc++-v3/ChangeLog:
* testsuite/25_algorithms/all_of/constexpr.cc: Check result of
the algorithm.
* testsuite/25_algorithms/any_of/constexpr.cc: Likewise.
* testsuite/25_algorithms/binary_search/constexpr.cc: Likewise.
* testsuite/25_algorithms/copy_backward/constexpr.cc: Likewise.
* testsuite/25_algorithms/count/constexpr.cc: Likewise.
* testsuite/25_algorithms/equal/constexpr.cc: Likewise.
* testsuite/25_algorithms/equal_range/constexpr.cc: Likewise.
* testsuite/25_algorithms/fill/constexpr.cc: Likewise.
* testsuite/25_algorithms/find_end/constexpr.cc: Likewise.
* testsuite/25_algorithms/find_if/constexpr.cc: Likewise.
* testsuite/25_algorithms/is_partitioned/constexpr.cc: Likewise.
* testsuite/25_algorithms/is_permutation/constexpr.cc: Likewise.
* testsuite/25_algorithms/is_sorted_until/constexpr.cc:
Likewise.
* testsuite/25_algorithms/lexicographical_compare/constexpr.cc:
Likewise.
* testsuite/25_algorithms/lower_bound/constexpr.cc: Likewise.
* testsuite/25_algorithms/merge/constexpr.cc: Likewise.
* testsuite/25_algorithms/mismatch/constexpr.cc: Likewise.
* testsuite/25_algorithms/none_of/constexpr.cc: Likewise.
* testsuite/25_algorithms/partition_copy/constexpr.cc: Likewise.
* testsuite/25_algorithms/remove_copy/constexpr.cc: Likewise.
* testsuite/25_algorithms/remove_copy_if/constexpr.cc: Likewise.
* testsuite/25_algorithms/remove_if/constexpr.cc: Likewise.
* testsuite/25_algorithms/replace_if/constexpr.cc: Likewise.
* testsuite/25_algorithms/reverse/constexpr.cc: Likewise.
* testsuite/25_algorithms/reverse_copy/constexpr.cc: Likewise.
* testsuite/25_algorithms/rotate_copy/constexpr.cc: Likewise.
* testsuite/25_algorithms/search/constexpr.cc: Likewise.
* testsuite/25_algorithms/set_difference/constexpr.cc: Likewise.
* testsuite/25_algorithms/set_intersection/constexpr.cc:
Likewise.
* testsuite/25_algorithms/set_symmetric_difference/constexpr.cc:
Likewise.
* testsuite/25_algorithms/set_union/constexpr.cc: Likewise.
* testsuite/25_algorithms/unique_copy/constexpr.cc: Likewise.
* testsuite/25_algorithms/upper_bound/constexpr.cc: Likewise.
libstdc++-v3/ChangeLog:
* testsuite/25_algorithms/lexicographical_compare/constrained.cc:
(test03): Fix initializing the vector vy with the array y of size 4.
This fixes a division by zero in the selection-sampling std::__sample
overload when the input range is empty (and hence __unsampled_sz is 0).
libstdc++-v3/ChangeLog:
* include/bits/stl_algo.h (__sample): Exit early when the
input range is empty.
* testsuite/25_algorithms/sample/3.cc: New test.
As per P0202.
libstdc++-v3/ChangeLog:
* include/bits/stl_algo.h (for_each_n): Mark constexpr for C++20.
(search): Likewise for the overload that takes a searcher.
* testsuite/25_algorithms/for_each/constexpr.cc: Test constexpr
std::for_each_n.
* testsuite/25_algorithms/search/constexpr.cc: Test constexpr
std::search overload that takes a searcher.
These tests do not actually require TBB, because they only inspect the
feature test macros present in the headers. However, if TBB is installed
then its headers will be included, and the version will be checked. If
the version is too old, compilation fails due to a #error directive.
This change disables the tests if TBB is not present, so that we skip
them instead of failing.
libstdc++-v3/ChangeLog:
PR libstdc++/96718
* testsuite/25_algorithms/pstl/feature_test-2.cc: Require
tbb-backend effective target.
* testsuite/25_algorithms/pstl/feature_test-3.cc: Likewise.
* testsuite/25_algorithms/pstl/feature_test-5.cc: Likewise.
* testsuite/25_algorithms/pstl/feature_test.cc: Likewise.
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.
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.
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.
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.
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.
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.
When deciding whether to perform the memset optimization in ranges::fill_n, we
were crucially neglecting to check that the output pointer's value type is a
byte type. This patch adds such a check to the problematic condition in
ranges::fill_n.
At the same time, this patch relaxes the overly conservative
__is_byte<_Tp>::__value check that requires the fill type be a byte type. It's
overly conservative because it means we won't enable the memset optimization in
the following example
char c[100];
ranges::fill(c, 37);
because the fill type is deduced to be int here. Rather than requiring that the
fill type be a byte type, it seems safe to just require the fill type be an
integral type, which is what this patch does.
libstdc++-v3/ChangeLog:
PR libstdc++/94017
* include/bits/ranges_algobase.h (__fill_n_fn::operator()): Refine
condition for when to use memset, making sure to additionally check that
the output pointer's value type is a non-volatile byte type. Instead of
requiring that the fill type is a byte type, just require that it's an
integral type.
* testsuite/20_util/specialized_algorithms/uninitialized_fill/94017.cc:
New test.
* testsuite/20_util/specialized_algorithms/uninitialized_fill_n/94017.cc:
New test.
* testsuite/25_algorithms/fill/94013.cc: Uncomment part that was blocked
by PR 94017.
* testsuite/25_algorithms/fill/94017.cc: New test.
* testsuite/25_algorithms/fill_n/94017.cc: New test.
Several algorithms check the is_trivially_copyable trait to decide
whether to dispatch to memmove or memcmp as an optimization. Since
r271435 (CWG DR 2094) the trait is true for volatile-qualified scalars,
but we can't use memmove or memcmp when the type is volatile. We need to
also check for volatile types.
This is complicated by the fact that in C++20 (but not earlier standards)
iterator_traits<volatile T*>::value_type is T, so we can't just check
whether the value_type is volatile.
The solution in this patch is to introduce new traits __memcpyable and
__memcmpable which combine into a single trait the checks for pointers,
the value types being the same, and the type being trivially copyable
but not volatile-qualified.
PR libstdc++/94013
* include/bits/cpp_type_traits.h (__memcpyable, __memcmpable): New
traits to control when to use memmove and memcmp optimizations.
(__is_nonvolatile_trivially_copyable): New helper trait.
* include/bits/ranges_algo.h (__lexicographical_compare_fn): Do not
use memcmp optimization with volatile data.
* include/bits/ranges_algobase.h (__equal_fn): Use __memcmpable.
(__copy_or_move, __copy_or_move_backward): Use __memcpyable.
* include/bits/stl_algobase.h (__copy_move_a2): Use __memcpyable.
(__copy_move_backward_a2): Likewise.
(__equal_aux1): Use __memcmpable.
(__lexicographical_compare_aux): Do not use memcmp optimization with
volatile data.
* testsuite/25_algorithms/copy/94013.cc: New test.
* testsuite/25_algorithms/copy_backward/94013.cc: New test.
* testsuite/25_algorithms/equal/94013.cc: New test.
* testsuite/25_algorithms/fill/94013.cc: New test.
* testsuite/25_algorithms/lexicographical_compare/94013.cc: New test.
* testsuite/25_algorithms/move/94013.cc: New test.
* testsuite/25_algorithms/move_backward/94013.cc: New test.
The new 25_algorithms/lexicographical_compare/93972.cc test fails on
targets where char is unsigned, revealing an existing regression with
the std::__memcmp helper that had gone unnoticed in
std::lexicographical_compare. When comparing char and unsigned char, the
memcmp optimisation is enabled, but the new std::__memcmp function fails
to compile for mismatched types.
PR libstdc++/93972
* include/bits/stl_algobase.h (__memcmp): Allow pointer types to
differ.
* testsuite/25_algorithms/lexicographical_compare/uchar.cc: New test.
We were enabling the memcmp optimization in ranges::lexicographical_compare for
signed integral types and for integral types wider than a byte. But memcmp
gives the wrong answer for arrays of such types. This patch fixes this issue by
refining the condition that enables the memcmp optimization. It's now
consistent with the corresponding condition used in
std::lexicographical_compare.
libstdc++-v3/ChangeLog:
PR libstdc++/93972
* include/bits/ranges_algo.h (__lexicographical_compare_fn::operator()):
Fix condition for when to use memcmp, making it consistent with the
corresponding condition used in std::lexicographical_compare.
* testsuite/25_algorithms/lexicographical_compare/93972.cc: New test.
This fixes the failures in the constrained algos tests when they are run in
debug mode.
libstdc++-v3/ChangeLog:
* testsuite/25_algorithms/copy/constrained.cc: Don't assume that the
base() of a vector<>::iterator is a pointer.
* testsuite/25_algorithms/copy_backward/constrained.cc: Likewise.
* testsuite/25_algorithms/move/constrained.cc: Likewise.
* testsuite/25_algorithms/move_backward/constrained.cc: Likewise.
* testsuite/25_algorithms/inplace_merge/constrained.cc: Use foo.data()
instead of &foo[0].
* testsuite/25_algorithms/partial_sort/constrained.cc: Likewise.
* testsuite/25_algorithms/partial_sort_copy/constrained.cc: Likewise.
* testsuite/25_algorithms/shuffle/constrained.cc: Likewise.
* testsuite/25_algorithms/sort/constrained.cc: Likewise.
* testsuite/25_algorithms/stable_sort/constrained.cc: Likewise.
Although most of the old-style "concept checks" are only really usable
with C++98 because they enforce the wrong things, this is a simple
change that makes them a bit more useful for C++14 and up.
* include/bits/boost_concept_check.h (__function_requires): Add
_GLIBCXX14_CONSTEXPR.
* testsuite/25_algorithms/min/concept_checks.cc: New test.
The mutating sequence algorithms std::copy, std::copy_backward,
std::move and std::move_backward conditionally use __builtin_memmove
for trivially copyable types. However, because memmove isn't usable in
constant expressions the use of __builtin_memmove is wrapped in a
__memmove function which replaces __builtin_memmove with a handwritten
loop when std::is_constant_evaluated() is true.
This means we have a manual loop for non-trivially copyable cases, and a
different manual loop for trivially copyable but constexpr cases. The
latter loop has incorrect semantics for the {copy,move}_backward cases
and so isn't used for them. Until earlier today the latter loop also had
incorrect semantics for the std::move cases, trying to move from const
rvalues.
The approach taken by this patch is to remove the __memmove function
entirely and use the original (and correct) manual loops for the
constexpr cases as well as the non-trivially copyable cases. This was
already done for move_backward and copy_backward, but was incorrectly
turning copy_backward into move_backward, by failing to use the _IsMove
constant to select the right specialization. This patch also fixes that.
* include/bits/ranges_algobase.h (__copy_or_move): Do not use memmove
during constant evaluation. Call __builtin_memmove directly instead of
__memmove.
(__copy_or_move_backward): Likewise.
* include/bits/stl_algobase.h (__memmove): Remove.
(__copy_move<M, true, random_access_iterator_tag>::__copy_m)
(__copy_move_backward<M, true, random_access_iterator_tag>::__copy_m):
Use __builtin_memmove directly instead of __memmove.
(__copy_move_a2): Do not use memmove during constant evaluation.
(__copy_move_backward_a2): Use _IsMove constant to select correct
__copy_move_backward specialization.
* testsuite/25_algorithms/copy_backward/constexpr.cc: Check for copies
begin turned into moves during constant evaluation.
The std::move and std::move_backward algorithms dispatch to the
std::__memmove helper when appropriate. That function uses a
pointer-to-const for the source values, preventing them from being
moved. The two callers of that function have the same problem.
Rather than altering __memmove and its callers to work with const or
non-const source pointers, this takes a more conservative approach of
casting away the const at the point where we want to do a move
assignment. This relies on the fact that we only use __memmove when the
type is trivially copyable, so we know the move assignment doesn't alter
the source anyway.
PR libstdc++/93872
* include/bits/stl_algobase.h (__memmove): Cast away const before
doing move assignment.
* testsuite/25_algorithms/move/93872.cc: New test.
* testsuite/25_algorithms/move_backward/93872.cc: New test.
This patch adds std::shift_left and std::shift_right as per P0769R2. Alhough
these are STL-style algos, this patch places them in <bits/ranges_algo.h>
because they make use of some functions in the ranges namespace that are more
easily reachable from <bits/ranges_algo.h> than from <bits/stl_algo.h>, namely
ranges::next. In order to place these algos in <bits/stl_algo.h>, we would need
to include <bits/range_access.h> from <bits/stl_algo.h> which would undesirably
increase the size of <bits/stl_algo.h>.
libstdc++-v3/ChangeLog:
P0769R2 Add shift to <algorithm>
* include/bits/ranges_algo.h (shift_left, shift_right): New.
* testsuite/25_algorithms/shift_left/1.cc: New test.
* testsuite/25_algorithms/shift_right/1.cc: New test.
libstdc++-v3/ChangeLog:
P2106R0 Alternative wording for GB315 and GB316
* include/bits/ranges_algo.h (in_fun_result): New.
(for_each_result, for_each_n_result): Change into an alias of
in_fun_result.
(in_in_result): New.
(mismatch_result): Change into an alias of in_in_result.
(copy_if_result): Change into an alias of in_out_result.
(swap_ranges_result): Change into an alias of in_in_result.
(unary_transform_result): Change into an alias of in_out_result.
(in_in_out_result): New.
(binary_transform_result): Change into an alias of in_in_out_result.
(replace_copy_result, replace_copy_if_result, remove_copy_if_result,
remove_copy_result, unique_copy_result, reverse_copy_result,
rotate_copy_result, partial_sort_copy_result): Change into an alias of
in_out_result.
(in_out_out_result): New.
(partition_copy_result, merge_result): Change into an alias of
in_out_out_result.
(set_union_result, set_intersection_result): Change into an alias of
in_in_out_result.
(set_difference_result): Change into an alias of in_out_result.
(set_symmetric_difference): Change into an alias of in_in_out_result.
(min_max_result): New.
(minmax_result, minmax_element_result): Change into an alias of
min_max_result.
(in_found_result): New.
(next_permutation_result, prev_permutation_result): Change into an alias
of in_found_result.
(__next_permutation_fn::operator(), __prev_permutation_fn::operator()):
Adjust following changes to next_permutation_result and
prev_permutation_result.
* include/bits/ranges_algobase.h (in_out_result): New.
(copy_result, move_result, move_backward_result, copy_backward_result,
copy_n_result): Change into an alias of in_out_result.
* include/bits/ranges_uninitialized.h (uninitialized_copy_result,
uninitialized_copy_n_result, uninitialized_move_result,
uninitialized_move_n_result): Likewise.
* testsuite/25_algorithms/next_permutation/constrained.cc: Adjust uses of
structured bindings.
* testsuite/25_algorithms/prev_permutation/constrained.cc: Likewise.
This adds rangified overloads for for_each_n, sample and clamp as per P1243R4.
libstdc++-v3/ChangeLog:
P1243R4 Rangify new algorithms
* include/bits/ranges_algo.h (for_each_n_result, __for_each_n_fn,
for_each_n, __sample_fn, sample, __clamp_fn, clamp): New.
* testsuite/25_algorithms/clamp/constrained.cc: New test.
* testsuite/25_algorithms/for_each/constrained.cc: Augment test.
* testsuite/25_algorithms/sample/constrained.cc: New test.
This patch implements the C++20 ranges overloads for the algorithms in
[algorithms]. Most of the algorithms were reimplemented, with each of their
implementations very closely following the existing implementation in
bits/stl_algo.h and bits/stl_algobase.h. The reason for reimplementing most of
the algorithms instead of forwarding to their STL-style overload is because
forwarding cannot be conformantly and efficiently performed for algorithms that
operate on non-random-access iterators. But algorithms that operate on random
access iterators can safely and efficiently be forwarded to the STL-style
implementation, and this patch does so for push_heap, pop_heap, make_heap,
sort_heap, sort, stable_sort, nth_element, inplace_merge and stable_partition.
What's missing from this patch is debug-iterator and container specializations
that are present for some of the STL-style algorithms that need to be ported
over to the ranges algos. I marked them missing at TODO comments. There are
also some other minor outstanding TODOs.
The code that could use the most thorough review is ranges::__copy_or_move,
ranges::__copy_or_move_backward, ranges::__equal and
ranges::__lexicographical_compare. In the tests, I tried to test the interface
of each new overload, as well as the correctness of the new implementation.
libstdc++-v3/ChangeLog:
Implement C++20 constrained algorithms
* include/Makefile.am: Add new header.
* include/Makefile.in: Regenerate.
* include/std/algorithm: Include <bits/ranges_algo.h>.
* include/bits/ranges_algo.h: New file.
* testsuite/25_algorithms/adjacent_find/constrained.cc: New test.
* testsuite/25_algorithms/all_of/constrained.cc: New test.
* testsuite/25_algorithms/any_of/constrained.cc: New test.
* testsuite/25_algorithms/binary_search/constrained.cc: New test.
* testsuite/25_algorithms/copy/constrained.cc: New test.
* testsuite/25_algorithms/copy_backward/constrained.cc: New test.
* testsuite/25_algorithms/copy_if/constrained.cc: New test.
* testsuite/25_algorithms/copy_n/constrained.cc: New test.
* testsuite/25_algorithms/count/constrained.cc: New test.
* testsuite/25_algorithms/count_if/constrained.cc: New test.
* testsuite/25_algorithms/equal/constrained.cc: New test.
* testsuite/25_algorithms/equal_range/constrained.cc: New test.
* testsuite/25_algorithms/fill/constrained.cc: New test.
* testsuite/25_algorithms/fill_n/constrained.cc: New test.
* testsuite/25_algorithms/find/constrained.cc: New test.
* testsuite/25_algorithms/find_end/constrained.cc: New test.
* testsuite/25_algorithms/find_first_of/constrained.cc: New test.
* testsuite/25_algorithms/find_if/constrained.cc: New test.
* testsuite/25_algorithms/find_if_not/constrained.cc: New test.
* testsuite/25_algorithms/for_each/constrained.cc: New test.
* testsuite/25_algorithms/generate/constrained.cc: New test.
* testsuite/25_algorithms/generate_n/constrained.cc: New test.
* testsuite/25_algorithms/heap/constrained.cc: New test.
* testsuite/25_algorithms/includes/constrained.cc: New test.
* testsuite/25_algorithms/inplace_merge/constrained.cc: New test.
* testsuite/25_algorithms/is_partitioned/constrained.cc: New test.
* testsuite/25_algorithms/is_permutation/constrained.cc: New test.
* testsuite/25_algorithms/is_sorted/constrained.cc: New test.
* testsuite/25_algorithms/is_sorted_until/constrained.cc: New test.
* testsuite/25_algorithms/lexicographical_compare/constrained.cc: New
test.
* testsuite/25_algorithms/lower_bound/constrained.cc: New test.
* testsuite/25_algorithms/max/constrained.cc: New test.
* testsuite/25_algorithms/max_element/constrained.cc: New test.
* testsuite/25_algorithms/merge/constrained.cc: New test.
* testsuite/25_algorithms/min/constrained.cc: New test.
* testsuite/25_algorithms/min_element/constrained.cc: New test.
* testsuite/25_algorithms/minmax/constrained.cc: New test.
* testsuite/25_algorithms/minmax_element/constrained.cc: New test.
* testsuite/25_algorithms/mismatch/constrained.cc: New test.
* testsuite/25_algorithms/move/constrained.cc: New test.
* testsuite/25_algorithms/move_backward/constrained.cc: New test.
* testsuite/25_algorithms/next_permutation/constrained.cc: New test.
* testsuite/25_algorithms/none_of/constrained.cc: New test.
* testsuite/25_algorithms/nth_element/constrained.cc: New test.
* testsuite/25_algorithms/partial_sort/constrained.cc: New test.
* testsuite/25_algorithms/partial_sort_copy/constrained.cc: New test.
* testsuite/25_algorithms/partition/constrained.cc: New test.
* testsuite/25_algorithms/partition_copy/constrained.cc: New test.
* testsuite/25_algorithms/partition_point/constrained.cc: New test.
* testsuite/25_algorithms/prev_permutation/constrained.cc: New test.
* testsuite/25_algorithms/remove/constrained.cc: New test.
* testsuite/25_algorithms/remove_copy/constrained.cc: New test.
* testsuite/25_algorithms/remove_copy_if/constrained.cc: New test.
* testsuite/25_algorithms/remove_if/constrained.cc: New test.
* testsuite/25_algorithms/replace/constrained.cc: New test.
* testsuite/25_algorithms/replace_copy/constrained.cc: New test.
* testsuite/25_algorithms/replace_copy_if/constrained.cc: New test.
* testsuite/25_algorithms/replace_if/constrained.cc: New test.
* testsuite/25_algorithms/reverse/constrained.cc: New test.
* testsuite/25_algorithms/reverse_copy/constrained.cc: New test.
* testsuite/25_algorithms/rotate/constrained.cc: New test.
* testsuite/25_algorithms/rotate_copy/constrained.cc: New test.
* testsuite/25_algorithms/search/constrained.cc: New test.
* testsuite/25_algorithms/search_n/constrained.cc: New test.
* testsuite/25_algorithms/set_difference/constrained.cc: New test.
* testsuite/25_algorithms/set_intersection/constrained.cc: New test.
* testsuite/25_algorithms/set_symmetric_difference/constrained.cc: New
test.
* testsuite/25_algorithms/set_union/constrained.cc: New test.
* testsuite/25_algorithms/shuffle/constrained.cc: New test.
* testsuite/25_algorithms/sort/constrained.cc: New test.
* testsuite/25_algorithms/stable_partition/constrained.cc: New test.
* testsuite/25_algorithms/stable_sort/constrained.cc: New test.
* testsuite/25_algorithms/swap_ranges/constrained.cc: New test.
* testsuite/25_algorithms/transform/constrained.cc: New test.
* testsuite/25_algorithms/unique/constrained.cc: New test.
* testsuite/25_algorithms/unique_copy/constrained.cc: New test.
* testsuite/25_algorithms/upper_bound/constrained.cc: New test.