[libc++] Disallow volatile types in std::allocator

LWG 2447 is marked as `Complete`, but there is no `static_assert` to
reject volatile types in `std::allocator`. See the discussion at
https://reviews.llvm.org/D108856.

Add `static_assert` in `std::allocator` to disallow volatile types. Since this
is an implementation choice, mark the binding test as `libc++` only.

Remove tests that use containers backed by `std::allocator` that test
the container when used with a volatile type.

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D109056
This commit is contained in:
Joe Loser 2021-09-22 11:46:21 -04:00
parent ca999f7191
commit 400b33e18d
No known key found for this signature in database
GPG key ID: 1CDBEBC050EA230D
6 changed files with 42 additions and 69 deletions

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@ -21,4 +21,3 @@ Misc Tasks
* Find all sequences of >2 underscores and eradicate them.
* run clang-tidy on libc++
* Document the "conditionally-supported" bits of libc++
* Put a static_assert in std::allocator to deny const/volatile types (LWG 2447)

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@ -80,6 +80,7 @@ template <class _Tp>
class _LIBCPP_TEMPLATE_VIS allocator
: private __non_trivial_if<!is_void<_Tp>::value, allocator<_Tp> >
{
static_assert(!is_volatile<_Tp>::value, "std::allocator does not support volatile types");
public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;
@ -162,6 +163,7 @@ template <class _Tp>
class _LIBCPP_TEMPLATE_VIS allocator<const _Tp>
: private __non_trivial_if<!is_void<_Tp>::value, allocator<const _Tp> >
{
static_assert(!is_volatile<_Tp>::value, "std::allocator does not support volatile types");
public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;

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@ -0,0 +1,16 @@
//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// REQUIRES: libc++
// http://wg21.link/LWG2447 gives implementors freedom to reject volatile types in `std::allocator`.
#include <memory>
std::allocator<volatile int> A1; // expected-error@*:* {{std::allocator does not support volatile types}}
std::allocator<const volatile int> A2; // expected-error@*:* {{std::allocator does not support volatile types}}

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@ -204,8 +204,6 @@ void test()
test_true <std::deque< int>>();
#ifdef _LIBCPP_VERSION
test_true <std::deque<const int>>();
test_true <std::deque< volatile int>>();
test_true <std::deque<const volatile int>>();
#endif // _LIBCPP_VERSION
test_true <std::forward_list<int>>();
test_true <std::list<int>>();
@ -227,8 +225,6 @@ void test()
test_true <std::stack< int>>();
#ifdef _LIBCPP_VERSION
test_true <std::stack<const int>>();
test_true <std::stack< volatile int>>();
test_true <std::stack<const volatile int>>();
#endif // _LIBCPP_VERSION
test_true <std::queue<int>>();
test_true <std::priority_queue<int>>();

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@ -73,6 +73,26 @@ void test_pointer_to_function() {
void test_pointer_to_function() {}
#endif // _LIBCPP_VERSION
template <typename T>
void test(const T &t0)
{
{
T t1 = t0;
std::shared_ptr<T> p0 = std::make_shared<T>(t0);
std::shared_ptr<T> p1 = std::make_shared<T>(t1);
assert(*p0 == t0);
assert(*p1 == t1);
}
{
const T t1 = t0;
std::shared_ptr<const T> p0 = std::make_shared<const T>(t0);
std::shared_ptr<const T> p1 = std::make_shared<const T>(t1);
assert(*p0 == t0);
assert(*p1 == t1);
}
}
int main(int, char**)
{
int nc = globalMemCounter.outstanding_new;
@ -108,5 +128,9 @@ int main(int, char**)
#endif
assert(A::count == 0);
test<bool>(true);
test<int>(3);
test<double>(5.0);
return 0;
}

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@ -1,64 +0,0 @@
//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// <memory>
// shared_ptr
// template<class T, class... Args> shared_ptr<T> make_shared(Args&&... args);
#include <memory>
#include <cassert>
#include "test_macros.h"
template <typename T>
void test(const T &t0)
{
{
T t1 = t0;
std::shared_ptr<T> p0 = std::make_shared<T>(t0);
std::shared_ptr<T> p1 = std::make_shared<T>(t1);
assert(*p0 == t0);
assert(*p1 == t1);
}
{
const T t1 = t0;
std::shared_ptr<const T> p0 = std::make_shared<const T>(t0);
std::shared_ptr<const T> p1 = std::make_shared<const T>(t1);
assert(*p0 == t0);
assert(*p1 == t1);
}
{
volatile T t1 = t0;
std::shared_ptr<volatile T> p0 = std::make_shared<volatile T>(t0);
std::shared_ptr<volatile T> p1 = std::make_shared<volatile T>(t1);
assert(*p0 == t0);
assert(*p1 == t1);
}
{
const volatile T t1 = t0;
std::shared_ptr<const volatile T> p0 = std::make_shared<const volatile T>(t0);
std::shared_ptr<const volatile T> p1 = std::make_shared<const volatile T>(t1);
assert(*p0 == t0);
assert(*p1 == t1);
}
}
int main(int, char**)
{
test<bool>(true);
test<int>(3);
test<double>(5.0);
return 0;
}