[libcxx-commits] [libcxx] [libc++] Fix ambiguous call in ranges::count & std::count (PR #122529)
Peng Liu via libcxx-commits
libcxx-commits at lists.llvm.org
Fri Jan 10 13:21:24 PST 2025
https://github.com/winner245 created https://github.com/llvm/llvm-project/pull/122529
This PR fixes an ambiguous call encountered when using the `std::ranges::count` and `std::count` algorithms with `vector<bool>` and a custom-sized allocator.
Fixes #122528.
>From f3103bd663e68d350a00df4b1946ce698dd4114a Mon Sep 17 00:00:00 2001
From: Peng Liu <winner245 at hotmail.com>
Date: Fri, 10 Jan 2025 14:57:14 -0500
Subject: [PATCH] Fix ambiguous call in ranges::count & std::count for
vector<bool>::iterator
---
libcxx/include/__algorithm/count.h | 13 ++-
libcxx/include/__bit/popcount.h | 46 ++++++++
libcxx/include/__fwd/bit_reference.h | 18 ++++
.../alg.nonmodifying/alg.count/count.pass.cpp | 26 +++++
.../alg.count/ranges.count.pass.cpp | 101 ++++++++++++------
libcxx/test/support/sized_allocator.h | 58 ++++++++++
6 files changed, 225 insertions(+), 37 deletions(-)
create mode 100644 libcxx/test/support/sized_allocator.h
diff --git a/libcxx/include/__algorithm/count.h b/libcxx/include/__algorithm/count.h
index 6910b4f43e9934..7eac1f6a76023a 100644
--- a/libcxx/include/__algorithm/count.h
+++ b/libcxx/include/__algorithm/count.h
@@ -55,18 +55,21 @@ __count_bool(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
if (__first.__ctz_ != 0) {
__storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
__storage_type __dn = std::min(__clz_f, __n);
- __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
- __r = std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_) & __m);
+ __storage_type __m = __middle_mask<__storage_type>(__first.__ctz_, __clz_f - __dn);
+ // __r = std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_) & __m);
+ __r = std::popcount(__storage_type(std::__invert_if<!_ToCount>(*__first.__seg_) & __m));
__n -= __dn;
++__first.__seg_;
}
// do middle whole words
for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
- __r += std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_));
+ // __r += std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_));
+ __r += std::popcount(__storage_type(std::__invert_if<!_ToCount>(*__first.__seg_)));
// do last partial word
if (__n > 0) {
- __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
- __r += std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_) & __m);
+ __storage_type __m = __trailing_mask<__storage_type>(__bits_per_word - __n);
+ // __r += std::__libcpp_popcount(std::__invert_if<!_ToCount>(*__first.__seg_) & __m);
+ __r += std::popcount(__storage_type(std::__invert_if<!_ToCount>(*__first.__seg_) & __m));
}
return __r;
}
diff --git a/libcxx/include/__bit/popcount.h b/libcxx/include/__bit/popcount.h
index 5cf0a01d073382..a1ff92f072ad0b 100644
--- a/libcxx/include/__bit/popcount.h
+++ b/libcxx/include/__bit/popcount.h
@@ -15,6 +15,8 @@
#include <__bit/rotate.h>
#include <__concepts/arithmetic.h>
#include <__config>
+#include <__type_traits/enable_if.h>
+#include <__type_traits/is_unsigned.h>
#include <limits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
@@ -62,6 +64,50 @@ template <__libcpp_unsigned_integer _Tp>
# endif // __has_builtin(__builtin_popcountg)
}
+#else
+
+template <class _Tp, __enable_if_t<__has_builtin(__builtin_popcountg) && is_unsigned<_Tp>::value, int> = 0>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int popcount(_Tp __t) _NOEXCEPT {
+ return __builtin_popcountg(__t);
+}
+
+template <
+ class _Tp,
+ __enable_if_t<!__has_builtin(__builtin_popcountg) && is_unsigned<_Tp>::value && sizeof(_Tp) <= sizeof(unsigned int),
+ int> = 0>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int popcount(_Tp __t) _NOEXCEPT {
+ return std::__libcpp_popcount(static_cast<unsigned int>(__t));
+}
+
+template < class _Tp,
+ __enable_if_t<!__has_builtin(__builtin_popcountg) && is_unsigned<_Tp>::value &&
+ (sizeof(_Tp) > sizeof(unsigned int)) && sizeof(_Tp) <= sizeof(unsigned long),
+ int> = 0 >
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int popcount(_Tp __t) _NOEXCEPT {
+ return std::__libcpp_popcount(static_cast<unsigned long>(__t));
+}
+
+template < class _Tp,
+ __enable_if_t<!__has_builtin(__builtin_popcountg) && is_unsigned<_Tp>::value &&
+ (sizeof(_Tp) > sizeof(unsigned long)) && sizeof(_Tp) <= sizeof(unsigned long long),
+ int> = 0 >
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR int popcount(_Tp __t) _NOEXCEPT {
+ return std::__libcpp_popcount(static_cast<unsigned long long>(__t));
+}
+
+template < class _Tp,
+ __enable_if_t<!__has_builtin(__builtin_popcountg) && is_unsigned<_Tp>::value &&
+ (sizeof(_Tp) > sizeof(unsigned long long)),
+ int> = 0 >
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int popcount(_Tp __t) _NOEXCEPT {
+ int __ret = 0;
+ while (__t != 0) {
+ __ret += std::__libcpp_popcount(static_cast<unsigned long long>(__t));
+ __t >>= numeric_limits<unsigned long long>::digits;
+ }
+ return __ret;
+}
+
#endif // _LIBCPP_STD_VER >= 20
_LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__fwd/bit_reference.h b/libcxx/include/__fwd/bit_reference.h
index 237efb6db66429..c927e65747af08 100644
--- a/libcxx/include/__fwd/bit_reference.h
+++ b/libcxx/include/__fwd/bit_reference.h
@@ -10,6 +10,8 @@
#define _LIBCPP___FWD_BIT_REFERENCE_H
#include <__config>
+#include <__type_traits/enable_if.h>
+#include <__type_traits/is_unsigned.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
@@ -20,6 +22,22 @@ _LIBCPP_BEGIN_NAMESPACE_STD
template <class _Cp, bool _IsConst, typename _Cp::__storage_type = 0>
class __bit_iterator;
+template <class _StorageType, __enable_if_t<is_unsigned<_StorageType>::value, int> = 0>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _StorageType __leading_mask(unsigned __shift) {
+ return static_cast<_StorageType>(static_cast<_StorageType>(~static_cast<_StorageType>(0)) << __shift);
+}
+
+template <class _StorageType, __enable_if_t<is_unsigned<_StorageType>::value, int> = 0>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _StorageType __trailing_mask(unsigned __shift) {
+ return static_cast<_StorageType>(static_cast<_StorageType>(~static_cast<_StorageType>(0)) >> __shift);
+}
+
+template <class _StorageType, __enable_if_t<is_unsigned<_StorageType>::value, int> = 0>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _StorageType __middle_mask(unsigned __lshift, unsigned __rshift) {
+ return static_cast<_StorageType>(
+ std::__leading_mask<_StorageType>(__lshift) & std::__trailing_mask<_StorageType>(__rshift));
+}
+
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___FWD_BIT_REFERENCE_H
diff --git a/libcxx/test/std/algorithms/alg.nonmodifying/alg.count/count.pass.cpp b/libcxx/test/std/algorithms/alg.nonmodifying/alg.count/count.pass.cpp
index 7250c49a7ff952..7e5d0c1cc9e470 100644
--- a/libcxx/test/std/algorithms/alg.nonmodifying/alg.count/count.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.nonmodifying/alg.count/count.pass.cpp
@@ -21,6 +21,7 @@
#include <cstddef>
#include <vector>
+#include "sized_allocator.h"
#include "test_macros.h"
#include "test_iterators.h"
#include "type_algorithms.h"
@@ -36,6 +37,29 @@ struct Test {
}
};
+TEST_CONSTEXPR_CXX20 void test_bititer_with_custom_sized_types() {
+ {
+ using Alloc = sized_allocator<bool, std::uint8_t, std::int8_t>;
+ std::vector<bool, Alloc> in(100, true, Alloc(1));
+ assert(std::count(in.begin(), in.end(), true) == 100);
+ }
+ {
+ using Alloc = sized_allocator<bool, std::uint16_t, std::int16_t>;
+ std::vector<bool, Alloc> in(200, true, Alloc(1));
+ assert(std::count(in.begin(), in.end(), true) == 200);
+ }
+ {
+ using Alloc = sized_allocator<bool, std::uint32_t, std::int32_t>;
+ std::vector<bool, Alloc> in(200, true, Alloc(1));
+ assert(std::count(in.begin(), in.end(), true) == 200);
+ }
+ {
+ using Alloc = sized_allocator<bool, std::uint64_t, std::int64_t>;
+ std::vector<bool, Alloc> in(200, true, Alloc(1));
+ assert(std::count(in.begin(), in.end(), true) == 200);
+ }
+}
+
TEST_CONSTEXPR_CXX20 bool test() {
types::for_each(types::cpp17_input_iterator_list<const int*>(), Test());
@@ -51,6 +75,8 @@ TEST_CONSTEXPR_CXX20 bool test() {
}
}
+ test_bititer_with_custom_sized_types();
+
return true;
}
diff --git a/libcxx/test/std/algorithms/alg.nonmodifying/alg.count/ranges.count.pass.cpp b/libcxx/test/std/algorithms/alg.nonmodifying/alg.count/ranges.count.pass.cpp
index 6030bed47ec6a7..b3a9ccca22e4d0 100644
--- a/libcxx/test/std/algorithms/alg.nonmodifying/alg.count/ranges.count.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.nonmodifying/alg.count/ranges.count.pass.cpp
@@ -29,6 +29,7 @@
#include <ranges>
#include <vector>
+#include "sized_allocator.h"
#include "almost_satisfies_types.h"
#include "test_iterators.h"
@@ -67,13 +68,13 @@ constexpr void test_iterators() {
{
// simple test
{
- int a[] = {1, 2, 3, 4};
+ int a[] = {1, 2, 3, 4};
std::same_as<std::ptrdiff_t> auto ret = std::ranges::count(It(a), Sent(It(a + 4)), 3);
assert(ret == 1);
}
{
- int a[] = {1, 2, 3, 4};
- auto range = std::ranges::subrange(It(a), Sent(It(a + 4)));
+ int a[] = {1, 2, 3, 4};
+ auto range = std::ranges::subrange(It(a), Sent(It(a + 4)));
std::same_as<std::ptrdiff_t> auto ret = std::ranges::count(range, 3);
assert(ret == 1);
}
@@ -83,13 +84,13 @@ constexpr void test_iterators() {
// check that an empty range works
{
std::array<int, 0> a = {};
- auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 1);
+ auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 1);
assert(ret == 0);
}
{
std::array<int, 0> a = {};
- auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size())));
- auto ret = std::ranges::count(range, 1);
+ auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size())));
+ auto ret = std::ranges::count(range, 1);
assert(ret == 0);
}
}
@@ -98,13 +99,13 @@ constexpr void test_iterators() {
// check that a range with a single element works
{
std::array a = {2};
- auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 2);
+ auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 2);
assert(ret == 1);
}
{
std::array a = {2};
- auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size())));
- auto ret = std::ranges::count(range, 2);
+ auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size())));
+ auto ret = std::ranges::count(range, 2);
assert(ret == 1);
}
}
@@ -113,13 +114,13 @@ constexpr void test_iterators() {
// check that 0 is returned with no match
{
std::array a = {1, 1, 1};
- auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 0);
+ auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 0);
assert(ret == 0);
}
{
std::array a = {1, 1, 1};
- auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size())));
- auto ret = std::ranges::count(range, 0);
+ auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size())));
+ auto ret = std::ranges::count(range, 0);
assert(ret == 0);
}
}
@@ -128,13 +129,13 @@ constexpr void test_iterators() {
// check that more than one element is counted
{
std::array a = {3, 3, 4, 3, 3};
- auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 3);
+ auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 3);
assert(ret == 4);
}
{
std::array a = {3, 3, 4, 3, 3};
- auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size())));
- auto ret = std::ranges::count(range, 3);
+ auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size())));
+ auto ret = std::ranges::count(range, 3);
assert(ret == 4);
}
}
@@ -143,18 +144,41 @@ constexpr void test_iterators() {
// check that all elements are counted
{
std::array a = {5, 5, 5, 5};
- auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 5);
+ auto ret = std::ranges::count(It(a.data()), Sent(It(a.data() + a.size())), 5);
assert(ret == 4);
}
{
std::array a = {5, 5, 5, 5};
- auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size())));
- auto ret = std::ranges::count(range, 5);
+ auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data() + a.size())));
+ auto ret = std::ranges::count(range, 5);
assert(ret == 4);
}
}
}
+TEST_CONSTEXPR_CXX20 void test_bititer_with_custom_sized_types() {
+ {
+ using Alloc = sized_allocator<bool, std::uint8_t, std::int8_t>;
+ std::vector<bool, Alloc> in(100, true, Alloc(1));
+ assert(std::ranges::count(in, true) == 100);
+ }
+ {
+ using Alloc = sized_allocator<bool, std::uint16_t, std::int16_t>;
+ std::vector<bool, Alloc> in(200, true, Alloc(1));
+ assert(std::ranges::count(in, true) == 200);
+ }
+ {
+ using Alloc = sized_allocator<bool, std::uint32_t, std::int32_t>;
+ std::vector<bool, Alloc> in(200, true, Alloc(1));
+ assert(std::ranges::count(in, true) == 200);
+ }
+ {
+ using Alloc = sized_allocator<bool, std::uint64_t, std::int64_t>;
+ std::vector<bool, Alloc> in(200, true, Alloc(1));
+ assert(std::ranges::count(in, true) == 200);
+ }
+}
+
constexpr bool test() {
test_iterators<int*>();
test_iterators<const int*>();
@@ -167,12 +191,12 @@ constexpr bool test() {
{
// check that projections are used properly and that they are called with the iterator directly
{
- int a[] = {1, 2, 3, 4};
+ int a[] = {1, 2, 3, 4};
auto ret = std::ranges::count(a, a + 4, a + 3, [](int& i) { return &i; });
assert(ret == 1);
}
{
- int a[] = {1, 2, 3, 4};
+ int a[] = {1, 2, 3, 4};
auto ret = std::ranges::count(a, a + 3, [](int& i) { return &i; });
assert(ret == 1);
}
@@ -180,8 +204,10 @@ constexpr bool test() {
{
// check that std::invoke is used
- struct S { int i; };
- S a[] = { S{1}, S{3}, S{2} };
+ struct S {
+ int i;
+ };
+ S a[] = {S{1}, S{3}, S{2}};
std::same_as<std::ptrdiff_t> auto ret = std::ranges::count(a, 4, &S::i);
assert(ret == 0);
}
@@ -189,16 +215,22 @@ constexpr bool test() {
{
// count invocations of the projection
{
- int a[] = {1, 2, 3, 4};
+ int a[] = {1, 2, 3, 4};
int projection_count = 0;
- auto ret = std::ranges::count(a, a + 4, 2, [&](int i) { ++projection_count; return i; });
+ auto ret = std::ranges::count(a, a + 4, 2, [&](int i) {
+ ++projection_count;
+ return i;
+ });
assert(ret == 1);
assert(projection_count == 4);
}
{
- int a[] = {1, 2, 3, 4};
+ int a[] = {1, 2, 3, 4};
int projection_count = 0;
- auto ret = std::ranges::count(a, 2, [&](int i) { ++projection_count; return i; });
+ auto ret = std::ranges::count(a, 2, [&](int i) {
+ ++projection_count;
+ return i;
+ });
assert(ret == 1);
assert(projection_count == 4);
}
@@ -208,7 +240,7 @@ constexpr bool test() {
// check that an immobile type works
struct NonMovable {
NonMovable(const NonMovable&) = delete;
- NonMovable(NonMovable&&) = delete;
+ NonMovable(NonMovable&&) = delete;
constexpr NonMovable(int i_) : i(i_) {}
int i;
@@ -216,12 +248,12 @@ constexpr bool test() {
};
{
NonMovable a[] = {9, 8, 4, 3};
- auto ret = std::ranges::count(a, a + 4, NonMovable(8));
+ auto ret = std::ranges::count(a, a + 4, NonMovable(8));
assert(ret == 1);
}
{
NonMovable a[] = {9, 8, 4, 3};
- auto ret = std::ranges::count(a, NonMovable(8));
+ auto ret = std::ranges::count(a, NonMovable(8));
assert(ret == 1);
}
}
@@ -230,7 +262,7 @@ constexpr bool test() {
// check that difference_type is used
struct DiffTypeIterator {
using difference_type = signed char;
- using value_type = int;
+ using value_type = int;
int* it = nullptr;
@@ -238,7 +270,10 @@ constexpr bool test() {
constexpr DiffTypeIterator(int* i) : it(i) {}
constexpr int& operator*() const { return *it; }
- constexpr DiffTypeIterator& operator++() { ++it; return *this; }
+ constexpr DiffTypeIterator& operator++() {
+ ++it;
+ return *this;
+ }
constexpr void operator++(int) { ++it; }
bool operator==(const DiffTypeIterator&) const = default;
@@ -251,7 +286,7 @@ constexpr bool test() {
assert(ret == 1);
}
{
- int a[] = {5, 5, 4, 3, 2, 1};
+ int a[] = {5, 5, 4, 3, 2, 1};
auto range = std::ranges::subrange(DiffTypeIterator(a), DiffTypeIterator(a + 6));
std::same_as<signed char> decltype(auto) ret = std::ranges::count(range, 4);
assert(ret == 1);
@@ -270,6 +305,8 @@ constexpr bool test() {
}
}
+ test_bititer_with_custom_sized_types();
+
return true;
}
diff --git a/libcxx/test/support/sized_allocator.h b/libcxx/test/support/sized_allocator.h
new file mode 100644
index 00000000000000..9a16430f7eaf9c
--- /dev/null
+++ b/libcxx/test/support/sized_allocator.h
@@ -0,0 +1,58 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 TEST_SUPPORT_SIZED_ALLOCATOR_H
+#define TEST_SUPPORT_SIZED_ALLOCATOR_H
+
+#include <cstddef>
+#include <limits>
+#include <memory>
+#include <new>
+
+#include "test_macros.h"
+
+template <typename T, typename SIZE_TYPE = std::size_t, typename DIFF_TYPE = std::ptrdiff_t>
+class sized_allocator {
+ template <typename U, typename Sz, typename Diff>
+ friend class sized_allocator;
+
+public:
+ using value_type = T;
+ using size_type = SIZE_TYPE;
+ using difference_type = DIFF_TYPE;
+ using propagate_on_container_swap = std::true_type;
+
+ TEST_CONSTEXPR_CXX20 explicit sized_allocator(int d = 0) : data_(d) {}
+
+ template <typename U, typename Sz, typename Diff>
+ TEST_CONSTEXPR_CXX20 sized_allocator(const sized_allocator<U, Sz, Diff>& a) TEST_NOEXCEPT : data_(a.data_) {}
+
+ TEST_CONSTEXPR_CXX20 T* allocate(size_type n) {
+ if (n > max_size())
+ TEST_THROW(std::bad_array_new_length());
+ return std::allocator<T>().allocate(n);
+ }
+
+ TEST_CONSTEXPR_CXX20 void deallocate(T* p, size_type n) TEST_NOEXCEPT { std::allocator<T>().deallocate(p, n); }
+
+ TEST_CONSTEXPR size_type max_size() const TEST_NOEXCEPT {
+ return std::numeric_limits<size_type>::max() / sizeof(value_type);
+ }
+
+private:
+ int data_;
+
+ TEST_CONSTEXPR friend bool operator==(const sized_allocator& a, const sized_allocator& b) {
+ return a.data_ == b.data_;
+ }
+ TEST_CONSTEXPR friend bool operator!=(const sized_allocator& a, const sized_allocator& b) {
+ return a.data_ != b.data_;
+ }
+};
+
+#endif
\ No newline at end of file
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