https://gcc.gnu.org/g:646b24efaa50b149c12d0ae432999cb5a0cd12f2
commit r15-4797-g646b24efaa50b149c12d0ae432999cb5a0cd12f2 Author: Jonathan Wakely <[email protected]> Date: Tue Jan 9 13:16:11 2024 +0000 libstdc++: Add align_alloc attribute to aligned operator new The aligned versions of operator new should use the align_alloc attribute to help the compiler. PR c++/86878 requests that the compiler would use the attribute to warn about invalid attributes, so an XFAILed test is added for that. libstdc++-v3/ChangeLog: * libsupc++/new (operator new): Add attribute align_alloc(2) to overloads taking a std::align_val_t argument. * testsuite/18_support/new_aligned_warn.cc: New test. Reviewed-by: Jakub Jelinek <[email protected]> Diff: --- libstdc++-v3/libsupc++/new | 6 +++--- libstdc++-v3/testsuite/18_support/new_aligned_warn.cc | 13 +++++++++++++ 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/libstdc++-v3/libsupc++/new b/libstdc++-v3/libsupc++/new index e9a3d9b49a3e..4345030071bb 100644 --- a/libstdc++-v3/libsupc++/new +++ b/libstdc++-v3/libsupc++/new @@ -167,7 +167,7 @@ void operator delete[](void*, const std::nothrow_t&) #if __cpp_aligned_new _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t) _GLIBCXX_TXN_SAFE - __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); + __attribute__((__externally_visible__, __alloc_size__ (1), __alloc_align__ (2), __malloc__)); _GLIBCXX_NODISCARD void* operator new(std::size_t, std::align_val_t, const std::nothrow_t&) _GLIBCXX_TXN_SAFE _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); @@ -178,10 +178,10 @@ void operator delete(void*, std::align_val_t, const std::nothrow_t&) _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t) _GLIBCXX_TXN_SAFE - __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); + __attribute__((__externally_visible__, __alloc_size__ (1), __alloc_align__ (2), __malloc__)); _GLIBCXX_NODISCARD void* operator new[](std::size_t, std::align_val_t, const std::nothrow_t&) _GLIBCXX_TXN_SAFE - _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __malloc__)); + _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__, __alloc_size__ (1), __alloc_align__ (2), __malloc__)); void operator delete[](void*, std::align_val_t) _GLIBCXX_TXN_SAFE _GLIBCXX_USE_NOEXCEPT __attribute__((__externally_visible__)); void operator delete[](void*, std::align_val_t, const std::nothrow_t&) diff --git a/libstdc++-v3/testsuite/18_support/new_aligned_warn.cc b/libstdc++-v3/testsuite/18_support/new_aligned_warn.cc new file mode 100644 index 000000000000..e9d374abe317 --- /dev/null +++ b/libstdc++-v3/testsuite/18_support/new_aligned_warn.cc @@ -0,0 +1,13 @@ +// { dg-options "-Wattributes" } +// { dg-do compile { target c++17 } } + +#include <new> + +int main() +{ + // PR c++/86878 has a patch to make these warn. + (void) operator new(1, std::align_val_t(3)); // { dg-warning "power of two" "" { xfail *-*-* } } + (void) operator new[](1, std::align_val_t(10)); // { dg-warning "power of two" "" { xfail *-*-* } } + (void) operator new(1, std::align_val_t(0), std::nothrow_t()); // { dg-warning "power of two" "" { xfail *-*-* } } + (void) operator new[](1, std::align_val_t(-1), std::nothrow_t()); // { dg-warning "power of two" "" { xfail *-*-* } } +}
