[gcc r14-12158] libstdc++: Fix test FAIL due to -Wpointer-arith
Jonathan Wakely
redi@gcc.gnu.org
Fri Nov 14 15:58:20 GMT 2025
https://gcc.gnu.org/g:a9d6de2007d142c9dee14b45664e5a3a7e0b2df6
commit r14-12158-ga9d6de2007d142c9dee14b45664e5a3a7e0b2df6
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Thu Sep 26 23:38:41 2024 +0100
libstdc++: Fix test FAIL due to -Wpointer-arith
This fixes a FAIL due to a -Wpointer-arith warning when testing with
c++11 or c++14 dialects. As an extension our std::atomic<void*> supports
pointer arithmetic in C++11 and C++14, but due to the system header
changes there is now a warning about it. The warning seems reasonable,
so rather than suppress it we should make the test expect it.
While looking into this I decided to simplify some of the code related
to atomic<T*> arithmetic.
libstdc++-v3/ChangeLog:
* include/bits/atomic_base.h (__atomic_base<T*>::_M_type_size):
Replace overloaded functions with static _S_type_size.
* include/std/atomic (atomic<T*>): Use is_object_v instead of
is_object.
* testsuite/29_atomics/atomic/operators/pointer_partial_void.cc:
Add dg-warning for -Wpointer-arith warning.
(cherry picked from commit 500046d178bc78a8f18d529c62f7b45c8ad2c861)
Diff:
---
libstdc++-v3/include/bits/atomic_base.h | 33 ++++++++++------------
libstdc++-v3/include/std/atomic | 32 ++++++++++-----------
.../atomic/operators/pointer_partial_void.cc | 1 +
3 files changed, 32 insertions(+), 34 deletions(-)
diff --git a/libstdc++-v3/include/bits/atomic_base.h b/libstdc++-v3/include/bits/atomic_base.h
index 20901b7fc06f..4e0947c7ce34 100644
--- a/libstdc++-v3/include/bits/atomic_base.h
+++ b/libstdc++-v3/include/bits/atomic_base.h
@@ -686,12 +686,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__pointer_type _M_p _GLIBCXX20_INIT(nullptr);
- // Factored out to facilitate explicit specialization.
- constexpr ptrdiff_t
- _M_type_size(ptrdiff_t __d) const { return __d * sizeof(_PTp); }
-
- constexpr ptrdiff_t
- _M_type_size(ptrdiff_t __d) const volatile { return __d * sizeof(_PTp); }
+ static constexpr ptrdiff_t
+ _S_type_size(ptrdiff_t __d)
+ { return __d * sizeof(_PTp); }
public:
__atomic_base() noexcept = default;
@@ -741,42 +738,42 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
__pointer_type
operator++() noexcept
- { return __atomic_add_fetch(&_M_p, _M_type_size(1),
+ { return __atomic_add_fetch(&_M_p, _S_type_size(1),
int(memory_order_seq_cst)); }
__pointer_type
operator++() volatile noexcept
- { return __atomic_add_fetch(&_M_p, _M_type_size(1),
+ { return __atomic_add_fetch(&_M_p, _S_type_size(1),
int(memory_order_seq_cst)); }
__pointer_type
operator--() noexcept
- { return __atomic_sub_fetch(&_M_p, _M_type_size(1),
+ { return __atomic_sub_fetch(&_M_p, _S_type_size(1),
int(memory_order_seq_cst)); }
__pointer_type
operator--() volatile noexcept
- { return __atomic_sub_fetch(&_M_p, _M_type_size(1),
+ { return __atomic_sub_fetch(&_M_p, _S_type_size(1),
int(memory_order_seq_cst)); }
__pointer_type
operator+=(ptrdiff_t __d) noexcept
- { return __atomic_add_fetch(&_M_p, _M_type_size(__d),
+ { return __atomic_add_fetch(&_M_p, _S_type_size(__d),
int(memory_order_seq_cst)); }
__pointer_type
operator+=(ptrdiff_t __d) volatile noexcept
- { return __atomic_add_fetch(&_M_p, _M_type_size(__d),
+ { return __atomic_add_fetch(&_M_p, _S_type_size(__d),
int(memory_order_seq_cst)); }
__pointer_type
operator-=(ptrdiff_t __d) noexcept
- { return __atomic_sub_fetch(&_M_p, _M_type_size(__d),
+ { return __atomic_sub_fetch(&_M_p, _S_type_size(__d),
int(memory_order_seq_cst)); }
__pointer_type
operator-=(ptrdiff_t __d) volatile noexcept
- { return __atomic_sub_fetch(&_M_p, _M_type_size(__d),
+ { return __atomic_sub_fetch(&_M_p, _S_type_size(__d),
int(memory_order_seq_cst)); }
bool
@@ -931,22 +928,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_GLIBCXX_ALWAYS_INLINE __pointer_type
fetch_add(ptrdiff_t __d,
memory_order __m = memory_order_seq_cst) noexcept
- { return __atomic_fetch_add(&_M_p, _M_type_size(__d), int(__m)); }
+ { return __atomic_fetch_add(&_M_p, _S_type_size(__d), int(__m)); }
_GLIBCXX_ALWAYS_INLINE __pointer_type
fetch_add(ptrdiff_t __d,
memory_order __m = memory_order_seq_cst) volatile noexcept
- { return __atomic_fetch_add(&_M_p, _M_type_size(__d), int(__m)); }
+ { return __atomic_fetch_add(&_M_p, _S_type_size(__d), int(__m)); }
_GLIBCXX_ALWAYS_INLINE __pointer_type
fetch_sub(ptrdiff_t __d,
memory_order __m = memory_order_seq_cst) noexcept
- { return __atomic_fetch_sub(&_M_p, _M_type_size(__d), int(__m)); }
+ { return __atomic_fetch_sub(&_M_p, _S_type_size(__d), int(__m)); }
_GLIBCXX_ALWAYS_INLINE __pointer_type
fetch_sub(ptrdiff_t __d,
memory_order __m = memory_order_seq_cst) volatile noexcept
- { return __atomic_fetch_sub(&_M_p, _M_type_size(__d), int(__m)); }
+ { return __atomic_fetch_sub(&_M_p, _S_type_size(__d), int(__m)); }
};
namespace __atomic_impl
diff --git a/libstdc++-v3/include/std/atomic b/libstdc++-v3/include/std/atomic
index 1462cf5ec23f..608a9e7ca28d 100644
--- a/libstdc++-v3/include/std/atomic
+++ b/libstdc++-v3/include/std/atomic
@@ -450,7 +450,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator++(int) noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b++;
}
@@ -459,7 +459,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator++(int) volatile noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b++;
}
@@ -468,7 +468,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator--(int) noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b--;
}
@@ -477,7 +477,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator--(int) volatile noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b--;
}
@@ -486,7 +486,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator++() noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return ++_M_b;
}
@@ -495,7 +495,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator++() volatile noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return ++_M_b;
}
@@ -504,7 +504,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator--() noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return --_M_b;
}
@@ -513,7 +513,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator--() volatile noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return --_M_b;
}
@@ -522,7 +522,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator+=(ptrdiff_t __d) noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b.operator+=(__d);
}
@@ -531,7 +531,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator+=(ptrdiff_t __d) volatile noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b.operator+=(__d);
}
@@ -540,7 +540,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator-=(ptrdiff_t __d) noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b.operator-=(__d);
}
@@ -549,7 +549,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
operator-=(ptrdiff_t __d) volatile noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b.operator-=(__d);
}
@@ -670,7 +670,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m = memory_order_seq_cst) noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b.fetch_add(__d, __m);
}
@@ -680,7 +680,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m = memory_order_seq_cst) volatile noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b.fetch_add(__d, __m);
}
@@ -690,7 +690,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m = memory_order_seq_cst) noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b.fetch_sub(__d, __m);
}
@@ -700,7 +700,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
memory_order __m = memory_order_seq_cst) volatile noexcept
{
#if __cplusplus >= 201703L
- static_assert( is_object<_Tp>::value, "pointer to object type" );
+ static_assert( is_object_v<_Tp>, "pointer to object type" );
#endif
return _M_b.fetch_sub(__d, __m);
}
diff --git a/libstdc++-v3/testsuite/29_atomics/atomic/operators/pointer_partial_void.cc b/libstdc++-v3/testsuite/29_atomics/atomic/operators/pointer_partial_void.cc
index 255912e85c4c..5e5054a2ae45 100644
--- a/libstdc++-v3/testsuite/29_atomics/atomic/operators/pointer_partial_void.cc
+++ b/libstdc++-v3/testsuite/29_atomics/atomic/operators/pointer_partial_void.cc
@@ -69,3 +69,4 @@ int main(void)
return 0;
}
+// { dg-warning "invalid application of 'sizeof' to a void type" "" { target *-*-* } 0 }
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