On Fri, 1 Nov 2024 at 10:42, Jakub Jelinek <ja...@redhat.com> wrote:
>
> Hi!
>
> I've noticed alloc_align attribute is missing on the non-vector
> ::operator new with std::align_val_t and const std::nothrow_t&
> arguments, this patch adds it. The last hunk is just
> an attempt to make the line shorter.
> The first hunk originally added also __alloc_size__ (1) attribute,
> but seems that regresses
> FAIL: g++.dg/tm/pr46270.C -std=gnu++98 (test for excess errors)
> with
> Excess errors:
> .../libstdc++-v3/libsupc++/new:137:26: warning: new declaration 'void*
> operator new(std::size_t)' ambiguates built-in declaration 'void* operator
> new(long unsigned int) transaction_safe' [-Wbuiltin-declaration-mismatch]
> .../libstdc++-v3/libsupc++/new:140:26: warning: new declaration 'void*
> operator new [](std::size_t)' ambiguates built-in declaration 'void* operator
> new [](long unsigned int) transaction_safe' [-Wbuiltin-declaration-mismatch]
> I must say I have no clue why that happens only in C++98 (C++11 and
> above are quiet) and why only with -fgnu-tm, tried to debug that but
> am lost. It is some conflict with the predeclared ::operator new, but
> those clearly do have the externally_visible attribute, and alloc_size (1)
> attributes:
> extvisattr = build_tree_list (get_identifier ("externally_visible"),
> NULL_TREE);
> newattrs = tree_cons (get_identifier ("alloc_size"),
> build_tree_list (NULL_TREE, integer_one_node),
> extvisattr);
> newtype = cp_build_type_attribute_variant (ptr_ftype_sizetype, newattrs);
> newtype = build_exception_variant (newtype, new_eh_spec);
> ...
> tree opnew = push_cp_library_fn (NEW_EXPR, newtype, 0);
> DECL_IS_MALLOC (opnew) = 1;
> DECL_SET_IS_OPERATOR_NEW (opnew, true);
> DECL_IS_REPLACEABLE_OPERATOR (opnew) = 1;
> and at C++98 I think libstdc++ doesn't add transaction_safe attribute:
> // Conditionally enable annotations for the Transactional Memory TS on C++11.
> // Most of the following conditions are due to limitations in the current
> // implementation.
> #if __cplusplus >= 201103L && _GLIBCXX_USE_CXX11_ABI \
> && _GLIBCXX_USE_DUAL_ABI && __cpp_transactional_memory >= 201500L \
> && !_GLIBCXX_FULLY_DYNAMIC_STRING && _GLIBCXX_USE_WEAK_REF \
> && _GLIBCXX_USE_ALLOCATOR_NEW
> #define _GLIBCXX_TXN_SAFE transaction_safe
> #define _GLIBCXX_TXN_SAFE_DYN transaction_safe_dynamic
> #else
> #define _GLIBCXX_TXN_SAFE
> #define _GLIBCXX_TXN_SAFE_DYN
> #endif
> push_cp_library_fn adds transaction_safe attribute whenever -fgnu-tm
> is used, regardless of the other conditionals:
> if (flag_tm)
> apply_tm_attr (fn, get_identifier ("transaction_safe"));
>
> Anyway, omitting alloc_size (1) fixes that test and given that the
> predeclared operator new already has alloc_size (1) attribute, I think it
> can be safely left out.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK, thanks.
>
> 2024-11-01 Jakub Jelinek <ja...@redhat.com>
>
> * libsupc++/new (::operator new, ::operator new[]): Add malloc
> attribute where missing. Add alloc_align attribute when
> std::align_val_t is present and where it was missing. Formatting fix.
>
> --- libstdc++-v3/libsupc++/new.jj 2024-10-31 11:41:47.894615923 +0100
> +++ libstdc++-v3/libsupc++/new 2024-10-31 16:16:56.545859474 +0100
> @@ -136,10 +136,10 @@ namespace std
> */
> _GLIBCXX_NODISCARD void* operator new(std::size_t)
> _GLIBCXX_TXN_SAFE _GLIBCXX_THROW (std::bad_alloc)
> - __attribute__((__externally_visible__));
> + __attribute__((__externally_visible__, __malloc__));
> _GLIBCXX_NODISCARD void* operator new[](std::size_t)
> _GLIBCXX_TXN_SAFE _GLIBCXX_THROW (std::bad_alloc)
> - __attribute__((__externally_visible__));
> + __attribute__((__externally_visible__, __malloc__));
> void operator delete(void*) _GLIBCXX_TXN_SAFE _GLIBCXX_USE_NOEXCEPT
> __attribute__((__externally_visible__));
> void operator delete[](void*) _GLIBCXX_TXN_SAFE _GLIBCXX_USE_NOEXCEPT
> @@ -169,8 +169,8 @@ _GLIBCXX_NODISCARD void* operator new(st
> _GLIBCXX_TXN_SAFE
> __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_TXN_SAFE _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&)
> @@ -180,8 +180,8 @@ _GLIBCXX_NODISCARD void* operator new[](
> _GLIBCXX_TXN_SAFE
> __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), __alloc_align__ (2), __malloc__));
> + _GLIBCXX_TXN_SAFE _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&)
>
> Jakub
>
