llvm-project/libcxx/include/__algorithm/ranges_set_intersection.h
Louis Dionne 7b4622514d
[libc++] Fix missing and incorrect push/pop macros (#79204)
We recently noticed that the unwrap_iter.h file was pushing macros, but
it was pushing them again instead of popping them at the end of the
file. This led to libc++ basically swallowing any custom definition of
these macros in user code:

    #define min HELLO
    #include <algorithm>
    // min is not HELLO anymore, it's not defined

While investigating this issue, I noticed that our push/pop pragmas were
actually entirely wrong too. Indeed, instead of pushing macros like
`move`, we'd push `move(int, int)` in the pragma, which is not a valid
macro name. As a result, we would not actually push macros like `move`
-- instead we'd simply undefine them. This led to the following code not
working:

    #define move HELLO
    #include <algorithm>
    // move is not HELLO anymore

Fixing the pragma push/pop incantations led to a cascade of issues
because we use identifiers like `move` in a large number of places, and
all of these headers would now need to do the push/pop dance.

This patch fixes all these issues. First, it adds a check that we don't
swallow important names like min, max, move or refresh as explained
above. This is done by augmenting the existing
system_reserved_names.gen.py test to also check that the macros are what
we expect after including each header.

Second, it fixes the push/pop pragmas to work properly and adds missing
pragmas to all the files I could detect a failure in via the newly added
test.

rdar://121365472
2024-01-25 15:48:46 -05:00

115 lines
3.8 KiB
C++

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___ALGORITHM_RANGES_SET_INTERSECTION_H
#define _LIBCPP___ALGORITHM_RANGES_SET_INTERSECTION_H
#include <__algorithm/in_in_out_result.h>
#include <__algorithm/iterator_operations.h>
#include <__algorithm/make_projected.h>
#include <__algorithm/set_intersection.h>
#include <__config>
#include <__functional/identity.h>
#include <__functional/invoke.h>
#include <__functional/ranges_operations.h>
#include <__iterator/concepts.h>
#include <__iterator/mergeable.h>
#include <__ranges/access.h>
#include <__ranges/concepts.h>
#include <__ranges/dangling.h>
#include <__utility/move.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
#if _LIBCPP_STD_VER >= 20
_LIBCPP_BEGIN_NAMESPACE_STD
namespace ranges {
template <class _InIter1, class _InIter2, class _OutIter>
using set_intersection_result = in_in_out_result<_InIter1, _InIter2, _OutIter>;
namespace __set_intersection {
struct __fn {
template <input_iterator _InIter1,
sentinel_for<_InIter1> _Sent1,
input_iterator _InIter2,
sentinel_for<_InIter2> _Sent2,
weakly_incrementable _OutIter,
class _Comp = less,
class _Proj1 = identity,
class _Proj2 = identity>
requires mergeable<_InIter1, _InIter2, _OutIter, _Comp, _Proj1, _Proj2>
_LIBCPP_HIDE_FROM_ABI constexpr set_intersection_result<_InIter1, _InIter2, _OutIter> operator()(
_InIter1 __first1,
_Sent1 __last1,
_InIter2 __first2,
_Sent2 __last2,
_OutIter __result,
_Comp __comp = {},
_Proj1 __proj1 = {},
_Proj2 __proj2 = {}) const {
auto __ret = std::__set_intersection<_RangeAlgPolicy>(
std::move(__first1),
std::move(__last1),
std::move(__first2),
std::move(__last2),
std::move(__result),
ranges::__make_projected_comp(__comp, __proj1, __proj2));
return {std::move(__ret.__in1_), std::move(__ret.__in2_), std::move(__ret.__out_)};
}
template <input_range _Range1,
input_range _Range2,
weakly_incrementable _OutIter,
class _Comp = less,
class _Proj1 = identity,
class _Proj2 = identity>
requires mergeable<iterator_t<_Range1>, iterator_t<_Range2>, _OutIter, _Comp, _Proj1, _Proj2>
_LIBCPP_HIDE_FROM_ABI constexpr set_intersection_result<borrowed_iterator_t<_Range1>,
borrowed_iterator_t<_Range2>,
_OutIter>
operator()(_Range1&& __range1,
_Range2&& __range2,
_OutIter __result,
_Comp __comp = {},
_Proj1 __proj1 = {},
_Proj2 __proj2 = {}) const {
auto __ret = std::__set_intersection<_RangeAlgPolicy>(
ranges::begin(__range1),
ranges::end(__range1),
ranges::begin(__range2),
ranges::end(__range2),
std::move(__result),
ranges::__make_projected_comp(__comp, __proj1, __proj2));
return {std::move(__ret.__in1_), std::move(__ret.__in2_), std::move(__ret.__out_)};
}
};
} // namespace __set_intersection
inline namespace __cpo {
inline constexpr auto set_intersection = __set_intersection::__fn{};
} // namespace __cpo
} // namespace ranges
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_STD_VER >= 20
_LIBCPP_POP_MACROS
#endif // _LIBCPP___ALGORITHM_RANGES_SET_INTERSECTION_H