Re: [google] Use delete with size parameter in STL deallocate (issue5794070)

[Xinliang David Li <davidxl at google dot com>]

ok. As Ollie said, it needs to be in google/gcc-4_7 as well.

David

On Mon, Mar 12, 2012 at 6:03 PM, Easwaran Raman <eraman@google.com> wrote:
> This patch makes -fsized-delete define a macro __GXX_DELETE_WITH_SIZE__. If
> this macro is defined, the deallocate function in new_allocator.h invokes
> the two parameter delete operator with the size of the object. Tested by
> bootstrapping the compiler and ensuring no tests are broken. Also verified
> that compiling a C++ program that uses std::vector with -fsized-delete invokes
> the two parameter version of operator delete.
>
> OK for google/main and google/4_6 branches?
>
> c-family/ChangeLog.google-main:
> 2012-03-12 ? Easwaran Raman ?<eraman@google.com>
>
> ? ? ? ?* c-cppbuiltin.c (c_cpp_builtins): Define __GXX_DELETE_WITH_SIZE__ for
> ? ? ? ?C++ files compiled with -fsized-delete.
>
> libstdc++-v3/ChangeLog.google-main:
> 2012-03-12 ? Easwaran Raman ?<eraman@google.com>
> ? ? ? ?* include/ext/new_allocator.h (deallocate): Call delete with size if
> ? ? ? ?__GXX_DELETE_WITH_SIZE__ is defined.
>
>
> diff --git a/gcc/c-family/c-cppbuiltin.c b/gcc/c-family/c-cppbuiltin.c
> index ccf57fd..3c9a96b 100644
> --- a/gcc/c-family/c-cppbuiltin.c
> +++ b/gcc/c-family/c-cppbuiltin.c
> @@ -970,6 +970,8 @@ c_cpp_builtins (cpp_reader *pfile)
> ? ? ?format. ?*/
> ? if (ENABLE_DECIMAL_FLOAT && ENABLE_DECIMAL_BID_FORMAT)
> ? ? cpp_define (pfile, "__DECIMAL_BID_FORMAT__");
> + ?if (c_dialect_cxx () && flag_sized_delete)
> + ? ?cpp_define (pfile, "__GXX_DELETE_WITH_SIZE__");
> ?}
>
> ?/* Pass an object-like macro. ?If it doesn't lie in the user's
> diff --git a/libstdc++-v3/include/ext/new_allocator.h b/libstdc++-v3/include/ext/new_allocator.h
> index 0c82bd0..c972c1e 100644
> --- a/libstdc++-v3/include/ext/new_allocator.h
> +++ b/libstdc++-v3/include/ext/new_allocator.h
> @@ -94,10 +94,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> ? ? ? ?return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp)));
> ? ? ? }
>
> +#ifdef __GXX_DELETE_WITH_SIZE__
> + ? ? ?// __p is not permitted to be a null pointer.
> + ? ? ?void
> + ? ? ?deallocate(pointer __p, size_type __t)
> + ? ? ?{ ::operator delete(__p, __t * sizeof(_Tp)); }
> +#else
> ? ? ? // __p is not permitted to be a null pointer.
> ? ? ? void
> ? ? ? deallocate(pointer __p, size_type)
> ? ? ? { ::operator delete(__p); }
> +#endif
>
> ? ? ? size_type
> ? ? ? max_size() const _GLIBCXX_USE_NOEXCEPT
>
> --
> This patch is available for review at http://codereview.appspot.com/5794070