diff options
Diffstat (limited to 'boost/intrusive/detail/parent_from_member.hpp')
| -rw-r--r-- | boost/intrusive/detail/parent_from_member.hpp | 45 |
1 files changed, 36 insertions, 9 deletions
diff --git a/boost/intrusive/detail/parent_from_member.hpp b/boost/intrusive/detail/parent_from_member.hpp index 2afffb47bc..3dfe8d6461 100644 --- a/boost/intrusive/detail/parent_from_member.hpp +++ b/boost/intrusive/detail/parent_from_member.hpp @@ -1,6 +1,6 @@ ///////////////////////////////////////////////////////////////////////////// // -// (C) Copyright Ion Gaztanaga 2007-2012 +// (C) Copyright Ion Gaztanaga 2007-2013 // // Distributed under the Boost Software License, Version 1.0. // (See accompanying file LICENSE_1_0.txt or copy at @@ -12,13 +12,16 @@ #ifndef BOOST_INTRUSIVE_DETAIL_PARENT_FROM_MEMBER_HPP #define BOOST_INTRUSIVE_DETAIL_PARENT_FROM_MEMBER_HPP +#if defined(_MSC_VER) +# pragma once +#endif + #include <boost/intrusive/detail/config_begin.hpp> #include <cstddef> #if defined(BOOST_MSVC) || ((defined(_WIN32) || defined(__WIN32__) || defined(WIN32)) && defined(BOOST_INTEL)) - -#define BOOST_INTRUSIVE_MSVC_COMPLIANT_PTR_TO_MEMBER -#include <boost/cstdint.hpp> + #define BOOST_INTRUSIVE_MSVC_ABI_PTR_TO_MEMBER + #include <boost/static_assert.hpp> #endif namespace boost { @@ -29,15 +32,39 @@ template<class Parent, class Member> inline std::ptrdiff_t offset_from_pointer_to_member(const Member Parent::* ptr_to_member) { //The implementation of a pointer to member is compiler dependent. - #if defined(BOOST_INTRUSIVE_MSVC_COMPLIANT_PTR_TO_MEMBER) - //msvc compliant compilers use their the first 32 bits as offset (even in 64 bit mode) + #if defined(BOOST_INTRUSIVE_MSVC_ABI_PTR_TO_MEMBER) + + //MSVC compliant compilers use their the first 32 bits as offset (even in 64 bit mode) union caster_union { const Member Parent::* ptr_to_member; - boost::int32_t offset; + int offset; } caster; + + //MSVC ABI can use up to 3 int32 to represent pointer to member data + //with virtual base classes, in those cases there is no simple to + //obtain the address of the parent. So static assert to avoid runtime errors + BOOST_STATIC_ASSERT( sizeof(caster) == sizeof(int) ); + caster.ptr_to_member = ptr_to_member; return std::ptrdiff_t(caster.offset); + //Additional info on MSVC behaviour for the future. For 2/3 int ptr-to-member + //types dereference seems to be: + // + // vboffset = [compile_time_offset if 2-int ptr2memb] / + // [ptr2memb.i32[2] if 3-int ptr2memb]. + // vbtable = *(this + vboffset); + // adj = vbtable[ptr2memb.i32[1]]; + // var = adj + (this + vboffset) + ptr2memb.i32[0]; + // + //To reverse the operation we need to + // - obtain vboffset (in 2-int ptr2memb implementation only) + // - Go to Parent's vbtable and obtain adjustment at index ptr2memb.i32[1] + // - parent = member - adj - vboffset - ptr2memb.i32[0] + // + //Even accessing to RTTI we might not be able to obtain this information + //so anyone who thinks it's possible, please send a patch. + //This works with gcc, msvc, ac++, ibmcpp #elif defined(__GNUC__) || defined(__HP_aCC) || defined(BOOST_INTEL) || \ defined(__IBMCPP__) || defined(__DECCXX) @@ -84,8 +111,8 @@ inline const Parent *parent_from_member(const Member *member, const Member Paren } //namespace intrusive { } //namespace boost { -#ifdef BOOST_INTRUSIVE_MSVC_COMPLIANT_PTR_TO_MEMBER -#undef BOOST_INTRUSIVE_MSVC_COMPLIANT_PTR_TO_MEMBER +#ifdef BOOST_INTRUSIVE_MSVC_ABI_PTR_TO_MEMBER +#undef BOOST_INTRUSIVE_MSVC_ABI_PTR_TO_MEMBER #endif #include <boost/intrusive/detail/config_end.hpp> |