eugenis removed rL LLVM as the repository for this revision.
eugenis updated this revision to Diff 33246.
eugenis added a comment.
Introduced cmake options for specifying the desired ABI version.
ABI version affects library soname and include path (include/c++/vN).
Baked ABI version into the headers (autogenerated __config_version) so that,
ex. with -I/usr/include/c++/v2 you get major abi version=2 w/o additional -D
settings.
Clang support for selecting vN include path is coming as a separate change.
http://reviews.llvm.org/D11740
Files:
CMakeLists.txt
docs/Abi.rst
docs/BuildingLibcxx.rst
include/CMakeLists.txt
include/__config
include/__config_version.cmake
include/string
lib/CMakeLists.txt
Index: lib/CMakeLists.txt
===================================================================
--- lib/CMakeLists.txt
+++ lib/CMakeLists.txt
@@ -129,8 +129,8 @@
COMPILE_FLAGS "${LIBCXX_COMPILE_FLAGS}"
LINK_FLAGS "${LIBCXX_LINK_FLAGS}"
OUTPUT_NAME "c++"
- VERSION "1.0"
- SOVERSION "1"
+ VERSION "${LIBCXX_ABI_MAJOR_VERSION}.${LIBCXX_ABI_MINOR_VERSION}"
+ SOVERSION "${LIBCXX_ABI_MAJOR_VERSION}"
)
install(TARGETS cxx
Index: include/string
===================================================================
--- include/string
+++ include/string
@@ -1185,7 +1185,7 @@
#pragma warning( pop )
#endif // _LIBCPP_MSVC
-#ifdef _LIBCPP_ALTERNATE_STRING_LAYOUT
+#ifdef _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
template <class _CharT, size_t = sizeof(_CharT)>
struct __padding
@@ -1198,7 +1198,7 @@
{
};
-#endif // _LIBCPP_ALTERNATE_STRING_LAYOUT
+#endif // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
template<class _CharT, class _Traits, class _Allocator>
class _LIBCPP_TYPE_VIS_ONLY basic_string
@@ -1234,7 +1234,7 @@
private:
-#ifdef _LIBCPP_ALTERNATE_STRING_LAYOUT
+#ifdef _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
struct __long
{
@@ -1294,7 +1294,7 @@
value_type __data_[__min_cap];
};
-#endif // _LIBCPP_ALTERNATE_STRING_LAYOUT
+#endif // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
union __ulx{__long __lx; __short __lxx;};
@@ -1696,7 +1696,7 @@
const allocator_type& __alloc() const _NOEXCEPT
{return __r_.second();}
-#ifdef _LIBCPP_ALTERNATE_STRING_LAYOUT
+#ifdef _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
_LIBCPP_INLINE_VISIBILITY
void __set_short_size(size_type __s) _NOEXCEPT
@@ -1714,7 +1714,7 @@
{return __r_.first().__s.__size_;}
# endif
-#else // _LIBCPP_ALTERNATE_STRING_LAYOUT
+#else // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
_LIBCPP_INLINE_VISIBILITY
void __set_short_size(size_type __s) _NOEXCEPT
@@ -1732,7 +1732,7 @@
{return __r_.first().__s.__size_ >> 1;}
# endif
-#endif // _LIBCPP_ALTERNATE_STRING_LAYOUT
+#endif // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
_LIBCPP_INLINE_VISIBILITY
void __set_long_size(size_type __s) _NOEXCEPT
Index: include/__config_version.cmake
===================================================================
--- include/__config_version.cmake
+++ include/__config_version.cmake
@@ -0,0 +1,19 @@
+// -*- C++ -*-
+//===--------------------------- __config_version -------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_CONFIG_VERSION
+#define _LIBCPP_CONFIG_VERSION
+
+#define _LIBCPP_ABI_MAJOR_VERSION ${LIBCXX_ABI_MAJOR_VERSION}
+#define _LIBCPP_ABI_MINOR_VERSION ${LIBCXX_ABI_MINOR_VERSION}
+
+#define _LIBCPP_ABI_VERSION (_LIBCPP_ABI_MAJOR_VERSION * 100 + _LIBCPP_ABI_MINOR_VERSION)
+
+#endif
Index: include/__config
===================================================================
--- include/__config
+++ include/__config
@@ -11,6 +11,8 @@
#ifndef _LIBCPP_CONFIG
#define _LIBCPP_CONFIG
+#include <__config_version>
+
#if !defined(_MSC_VER) || defined(__clang__)
#pragma GCC system_header
#endif
@@ -23,12 +25,14 @@
#define _LIBCPP_VERSION 3800
-#define _LIBCPP_ABI_VERSION 1
+#if _LIBCPP_ABI_VERSION >= 200
+#define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
+#endif
#define _LIBCPP_CONCAT1(_LIBCPP_X,_LIBCPP_Y) _LIBCPP_X##_LIBCPP_Y
#define _LIBCPP_CONCAT(_LIBCPP_X,_LIBCPP_Y) _LIBCPP_CONCAT1(_LIBCPP_X,_LIBCPP_Y)
-#define _LIBCPP_NAMESPACE _LIBCPP_CONCAT(__,_LIBCPP_ABI_VERSION)
+#define _LIBCPP_NAMESPACE _LIBCPP_CONCAT(__,_LIBCPP_ABI_MAJOR_VERSION)
#ifndef __has_attribute
@@ -230,9 +234,10 @@
#if defined(__clang__)
-#if defined(__APPLE__) && !defined(__i386__) && !defined(__x86_64__) && \
- !defined(__arm__)
-#define _LIBCPP_ALTERNATE_STRING_LAYOUT
+#if (defined(__APPLE__) && !defined(__i386__) && !defined(__x86_64__) && \
+ !defined(__arm__)) || \
+ defined(_LIBCPP_ALTERNATE_STRING_LAYOUT)
+#define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
#endif
#if __has_feature(cxx_alignas)
Index: include/CMakeLists.txt
===================================================================
--- include/CMakeLists.txt
+++ include/CMakeLists.txt
@@ -3,20 +3,25 @@
endif()
set(LIBCXX_HEADER_PATTERN
PATTERN "*"
+ PATTERN "__config_version.cmake" EXCLUDE
PATTERN "CMakeLists.txt" EXCLUDE
PATTERN ".svn" EXCLUDE
${LIBCXX_SUPPORT_HEADER_PATTERN}
)
file(COPY .
- DESTINATION "${CMAKE_BINARY_DIR}/include/c++/v1"
+ DESTINATION "${CMAKE_BINARY_DIR}/include/c++/v${LIBCXX_ABI_MAJOR_VERSION}"
FILES_MATCHING
${LIBCXX_HEADER_PATTERN}
)
+configure_file(
+ __config_version.cmake
+ "${CMAKE_BINARY_DIR}/include/c++/v${LIBCXX_ABI_MAJOR_VERSION}/__config_version")
+
if (LIBCXX_INSTALL_HEADERS)
- install(DIRECTORY .
- DESTINATION include/c++/v1
+ install(DIRECTORY ${CMAKE_BINARY_DIR}/include/c++/v${LIBCXX_ABI_MAJOR_VERSION}
+ DESTINATION include/c++
COMPONENT libcxx
FILES_MATCHING
${LIBCXX_HEADER_PATTERN}
Index: docs/BuildingLibcxx.rst
===================================================================
--- docs/BuildingLibcxx.rst
+++ docs/BuildingLibcxx.rst
@@ -193,6 +193,21 @@
Build libc++ with run time type information.
+
+libc++ Feature options
+----------------------
+
+The following options allow building libc++ for a different ABI version.
+
+.. option:: LIBCXX_ABI_MAJOR_VERSION:STRING
+
+ **Default**: ``1``
+
+.. option:: LIBCXX_ABI_MINOR_VERSION:STRING
+
+ **Default**: ``0``
+
+
.. _LLVM-specific variables:
LLVM-specific options
Index: docs/Abi.rst
===================================================================
--- docs/Abi.rst
+++ docs/Abi.rst
@@ -0,0 +1,23 @@
+
+====================
+Libc++ ABI stability
+====================
+
+Libc++ aims to preserve stable ABI to avoid subtle bugs when code built to the old ABI
+is linked with the code build to the new ABI. At the same time, libc++ allows ABI-breaking
+improvements and bugfixes for the scenarios when ABI change is not a issue.
+
+To support both cases, libc++ allows specifying the ABI version at the build time.
+The version is defined with 2 cmake options, LIBCXX_ABI_MAJOR_VERSION and LIBCXX_ABI_MINOR_VERSION,
+which translate into C++ macro definitions _LIBCPP_ABI_MAJOR_VERSION, _LIBCPP_ABI_MINOR_VERSION and _LIBCPP_ABI_VERSION.
+
+Any ABI-changing feature is placed under it's own macro, _LIBCPP_ABI_XXX, which is enabled
+based on the value of _LIBCPP_ABI_VERSION.
+
+Changes are classified based on their importance and the scope of the ABI break they create into "major" and "minor"
+breaks.
+
+Major breaks are opt-in. They are enabled in the next (future) major ABI version.
+Minor breaks are enabled in the next minor ABI version, and the default minor ABI version is bumped. Users that can not take
+this breakage must build with the appropriate LIBCXX_ABI_MINOR_VERSION to opt out.
+
Index: CMakeLists.txt
===================================================================
--- CMakeLists.txt
+++ CMakeLists.txt
@@ -57,6 +57,8 @@
"Define suffix of library directory name (32/64)")
option(LIBCXX_INSTALL_HEADERS "Install the libc++ headers." ON)
option(LIBCXX_INSTALL_SUPPORT_HEADERS "Install libc++ support headers." ON)
+set(LIBCXX_ABI_MAJOR_VERSION 1 CACHE STRING "Major ABI version of libc++.")
+set(LIBCXX_ABI_MINOR_VERSION 0 CACHE STRING "Minor ABI version of libc++.")
# ABI Library options ---------------------------------------------------------
set(LIBCXX_CXX_ABI "${LIBCXX_CXX_ABI}" CACHE STRING
@@ -287,6 +289,7 @@
# Setup Source Code And Tests
#===============================================================================
include_directories(include)
+include_directories("${CMAKE_BINARY_DIR}/include/c++/v${LIBCXX_ABI_MAJOR_VERSION}")
add_subdirectory(include)
add_subdirectory(lib)
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