[libc++] Replace LIBCXX_ENABLE_STATIC_ABI_LIBRARY & friends by a new LIBCXX_CXX_ABI choice #112978
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@llvm/pr-subscribers-github-workflow @llvm/pr-subscribers-libcxx Author: Louis Dionne (ldionne) ChangesInstead of having complicated options like LIBCXX_ENABLE_STATIC_ABI_LIBRARY and LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY, introduce a more general mechanism to select the ABI library used by libc++. The new mechanism allows specifying the ABI library for the static libc++ and the shared libc++ separately, and allows selecting a "merged" flavor of libc++ for both the in-tree libc++abi and any external static ABI library. As an example, one can now specify arbitrary combinations like which would have been impossible or very brittle in the past. In theory, one can even select an entirely different ABI library for the static and the shared libc++ (e.g. libc++abi vs libsupc++), although supporting that is not a primary goal of this patch but merely a result of the general mechanism. Closes #77655 Differential Revision: https://reviews.llvm.org/D125683 Patch is 42.33 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/112978.diff 18 Files Affected:
diff --git a/clang/cmake/caches/Android.cmake b/clang/cmake/caches/Android.cmake
index d5ca6b50d4ada7..dbf66539591394 100644
--- a/clang/cmake/caches/Android.cmake
+++ b/clang/cmake/caches/Android.cmake
@@ -21,8 +21,8 @@ if (LIBCXX_ENABLE_ABI_LINKER_SCRIPT)
list(APPEND EXTRA_ARGS -DLIBCXX_ENABLE_ABI_LINKER_SCRIPT=${LIBCXX_ENABLE_ABI_LINKER_SCRIPT})
endif()
-if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
- list(APPEND EXTRA_ARGS -DLIBCXX_ENABLE_STATIC_ABI_LIBRARY=${LIBCXX_ENABLE_STATIC_ABI_LIBRARY})
+if (LIBCXX_CXX_ABI)
+ list(APPEND EXTRA_ARGS -DLIBCXX_CXX_ABI=${LIBCXX_CXX_ABI})
endif()
if (LLVM_BUILD_EXTERNAL_COMPILER_RT)
diff --git a/clang/cmake/caches/CrossWinToARMLinux.cmake b/clang/cmake/caches/CrossWinToARMLinux.cmake
index 87118bbd33377d..15341aeb283801 100644
--- a/clang/cmake/caches/CrossWinToARMLinux.cmake
+++ b/clang/cmake/caches/CrossWinToARMLinux.cmake
@@ -215,10 +215,8 @@ set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXXABI_ENABLE_SHARED
set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ENABLE_SHARED ${TOOLCHAIN_SHARED_LIBS} CACHE BOOL "")
set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ABI_VERSION ${LIBCXX_ABI_VERSION} CACHE STRING "")
-set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_CXX_ABI "libcxxabi" CACHE STRING "") #!!!
+set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_CXX_ABI "merged-libcxxabi" CACHE STRING "") #!!!
set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ENABLE_NEW_DELETE_DEFINITIONS ON CACHE BOOL "")
-# Merge libc++ and libc++abi libraries into the single libc++ library file.
-set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
# Avoid searching for the python3 interpreter during the runtimes configuration for the cross builds.
# It starts searching the python3 package using the target's sysroot path, that usually is not compatible with the build host.
diff --git a/clang/cmake/caches/Fuchsia-stage2.cmake b/clang/cmake/caches/Fuchsia-stage2.cmake
index 5af98c7b3b3fba..761a31e486ad34 100644
--- a/clang/cmake/caches/Fuchsia-stage2.cmake
+++ b/clang/cmake/caches/Fuchsia-stage2.cmake
@@ -83,7 +83,7 @@ if(APPLE)
set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
set(LIBCXX_ABI_VERSION 2 CACHE STRING "")
set(LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
- set(LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
+ set(LIBCXX_CXX_ABI "merged-libcxxabi" CACHE STRING "")
set(LIBCXX_HARDENING_MODE "none" CACHE STRING "")
set(LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
set(RUNTIMES_CMAKE_ARGS "-DCMAKE_OSX_DEPLOYMENT_TARGET=10.13;-DCMAKE_OSX_ARCHITECTURES=arm64|x86_64" CACHE STRING "")
@@ -180,9 +180,9 @@ foreach(target aarch64-unknown-linux-gnu;armv7-unknown-linux-gnueabihf;i386-unkn
set(RUNTIMES_${target}_LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
+ set(RUNTIMES_${target}_LIBCXX_CXX_ABI "merged-libcxxabi" CACHE STRING "")
set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
- set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")
set(RUNTIMES_${target}_SANITIZER_CXX_ABI "libc++" CACHE STRING "")
@@ -244,10 +244,10 @@ if(FUCHSIA_SDK)
set(RUNTIMES_${target}_LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXXABI_HERMETIC_STATIC_LIBRARY ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXXABI_INSTALL_STATIC_LIBRARY OFF CACHE BOOL "")
+ set(RUNTIMES_${target}_LIBCXX_ABILIB_FOR_STATIC "merged-libcxxabi" CACHE STRING "")
+ set(RUNTIMES_${target}_LIBCXX_ABILIB_FOR_SHARED "shared-libcxxabi" CACHE STRING "")
set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
- set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_HERMETIC_STATIC_LIBRARY ON CACHE BOOL "")
- set(RUNTIMES_${target}_LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY OFF CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")
set(RUNTIMES_${target}_LLVM_ENABLE_RUNTIMES "compiler-rt;libcxx;libcxxabi;libunwind" CACHE STRING "")
diff --git a/clang/cmake/caches/Fuchsia.cmake b/clang/cmake/caches/Fuchsia.cmake
index 2d2dcb9ae6798d..5e31fe4fdd33df 100644
--- a/clang/cmake/caches/Fuchsia.cmake
+++ b/clang/cmake/caches/Fuchsia.cmake
@@ -109,6 +109,7 @@ endif()
if(WIN32)
set(LIBCXX_ABI_VERSION 2 CACHE STRING "")
+ set(LIBCXX_CXX_ABI "merged-libcxxabi" CACHE STRING "")
set(LIBCXX_ENABLE_ABI_LINKER_SCRIPT OFF CACHE BOOL "")
set(LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
set(BUILTINS_CMAKE_ARGS -DCMAKE_SYSTEM_NAME=Windows CACHE STRING "")
@@ -125,7 +126,6 @@ else()
set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
set(LIBCXX_ABI_VERSION 2 CACHE STRING "")
set(LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
- set(LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
set(LIBCXX_HARDENING_MODE "none" CACHE STRING "")
set(LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
set(LLVM_ENABLE_RUNTIMES "compiler-rt;libcxx;libcxxabi;libunwind" CACHE STRING "")
@@ -155,8 +155,8 @@ if(BOOTSTRAP_CMAKE_SYSTEM_NAME)
set(RUNTIMES_${target}_LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
- set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
+ set(RUNTIMES_${target}_LIBCXX_CXX_ABI "merged-libcxxabi" CACHE STRING "")
set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")
set(RUNTIMES_${target}_LLVM_ENABLE_RUNTIMES "compiler-rt;libcxx;libcxxabi;libunwind" CACHE STRING "")
set(RUNTIMES_${target}_SANITIZER_CXX_ABI "libc++" CACHE STRING "")
diff --git a/compiler-rt/cmake/Modules/AddCompilerRT.cmake b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
index e3d81d241b1054..5dec0face88ca5 100644
--- a/compiler-rt/cmake/Modules/AddCompilerRT.cmake
+++ b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
@@ -696,12 +696,11 @@ macro(add_custom_libcxx name prefix)
-DLIBCXXABI_ENABLE_SHARED=OFF
-DLIBCXXABI_HERMETIC_STATIC_LIBRARY=ON
-DLIBCXXABI_INCLUDE_TESTS=OFF
- -DLIBCXX_CXX_ABI=libcxxabi
+ -DLIBCXX_CXX_ABI="merged-libcxxabi"
-DLIBCXX_ENABLE_SHARED=OFF
-DLIBCXX_HERMETIC_STATIC_LIBRARY=ON
-DLIBCXX_INCLUDE_BENCHMARKS=OFF
-DLIBCXX_INCLUDE_TESTS=OFF
- -DLIBCXX_ENABLE_STATIC_ABI_LIBRARY=ON
${LIBCXX_CMAKE_ARGS}
INSTALL_COMMAND ""
STEP_TARGETS configure build
diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
index 574b262018cd3a..22853ca982af5f 100644
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -230,11 +230,22 @@ else()
endif()
set(LIBCXX_SUPPORTED_ABI_LIBRARIES none libcxxabi system-libcxxabi libcxxrt libstdc++ libsupc++ vcruntime)
-set(LIBCXX_CXX_ABI "${LIBCXX_DEFAULT_ABI_LIBRARY}" CACHE STRING "Specify C++ ABI library to use. Supported values are ${LIBCXX_SUPPORTED_ABI_LIBRARIES}.")
-if (NOT "${LIBCXX_CXX_ABI}" IN_LIST LIBCXX_SUPPORTED_ABI_LIBRARIES)
- message(FATAL_ERROR "Unsupported C++ ABI library: '${LIBCXX_CXX_ABI}'. Supported values are ${LIBCXX_SUPPORTED_ABI_LIBRARIES}.")
-endif()
-
+set(LIBCXX_CXX_ABI "${LIBCXX_DEFAULT_ABI_LIBRARY}" CACHE STRING
+ "Specify the C++ ABI library to use for the shared and the static libc++ libraries. Supported values are ${LIBCXX_SUPPORTED_ABI_LIBRARIES}.
+ This CMake option also supports \"consumption specifiers\", which specify how the selected ABI library should be consumed by
+ libc++. The supported specifiers are:
+ - `shared`: The selected ABI library should be used as a shared library.
+ - `static`: The selected ABI library should be used as a static library.
+ - `merged`: The selected ABI library should be a static library whose object files will be merged directly into the produced libc++ library.
+
+ A consumption specifier is provided by appending it to the name of the library, such as `LIBCXX_CXX_ABI=merged-libcxxabi`.
+ If no consumption specifier is provided, the libc++ shared library will default to using a shared ABI library, and the
+ libc++ static library will default to using a static ABI library.")
+set(LIBCXX_ABILIB_FOR_SHARED "${LIBCXX_CXX_ABI}" CACHE STRING "C++ ABI library to use for the shared libc++ library.")
+set(LIBCXX_ABILIB_FOR_STATIC "${LIBCXX_CXX_ABI}" CACHE STRING "C++ ABI library to use for the static libc++ library.")
+
+#############################
+# TODO: Remove these options in LLVM 21.
option(LIBCXX_ENABLE_STATIC_ABI_LIBRARY
"Use a static copy of the ABI library when linking libc++.
This option cannot be used with LIBCXX_ENABLE_ABI_LINKER_SCRIPT." OFF)
@@ -247,17 +258,34 @@ option(LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY
"Statically link the ABI library to shared library"
${LIBCXX_ENABLE_STATIC_ABI_LIBRARY})
+if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY OR LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY OR LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY)
+ message(WARNING "The LIBCXX_ENABLE_STATIC_ABI_LIBRARY, LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY and "
+ "LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY options have been deprecated in favor of "
+ "using LIBCXX_CXX_ABI=merged-libcxxabi. This will become an error in LLVM 21.")
+endif()
+if (LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY)
+ set(LIBCXX_ABILIB_FOR_STATIC "merged-libcxxabi" CACHE STRING "" FORCE)
+endif()
+if (LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY)
+ set(LIBCXX_ABILIB_FOR_SHARED "merged-libcxxabi" CACHE STRING "" FORCE)
+endif()
+#############################
+
# Generate and install a linker script inplace of libc++.so. The linker script
# will link libc++ to the correct ABI library. This option is on by default
-# on UNIX platforms other than Apple, and on the Fuchsia platform unless we
-# statically link libc++abi inside libc++.so, we don't build libc++.so at all
-# or we don't have any ABI library.
-if (LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY
- OR NOT LIBCXX_ENABLE_SHARED
- OR LIBCXX_CXX_ABI STREQUAL "none")
- set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE OFF)
-elseif((UNIX OR FUCHSIA) AND NOT APPLE)
- set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE ON)
+# on UNIX platforms other than Apple unless we are linking the ABI library as
+# an object library. This option is also disabled when the ABI library is not
+# specified or is specified to be "none".
+if(LIBCXX_ENABLE_SHARED)
+ if ((UNIX OR FUCHSIA) AND NOT APPLE)
+ if (LIBCXX_ABILIB_FOR_SHARED STREQUAL "merged-libcxxabi" OR LIBCXX_ABILIB_FOR_SHARED STREQUAL "none")
+ set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE OFF)
+ else()
+ set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE ON)
+ endif()
+ else()
+ set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE OFF)
+ endif()
else()
set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE OFF)
endif()
@@ -379,12 +407,6 @@ if (LIBCXX_ENABLE_ABI_LINKER_SCRIPT)
endif()
endif()
-if (LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY AND LIBCXX_ENABLE_ABI_LINKER_SCRIPT)
- message(FATAL_ERROR "Conflicting options given.
- LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY cannot be specified with
- LIBCXX_ENABLE_ABI_LINKER_SCRIPT")
-endif()
-
if (LIBCXX_ABI_FORCE_ITANIUM AND LIBCXX_ABI_FORCE_MICROSOFT)
message(FATAL_ERROR "Only one of LIBCXX_ABI_FORCE_ITANIUM and LIBCXX_ABI_FORCE_MICROSOFT can be specified.")
endif ()
@@ -481,10 +503,6 @@ include(config-ix)
#===============================================================================
# Setup Compiler Flags
#===============================================================================
-
-include(HandleLibC) # Setup the C library flags
-include(HandleLibCXXABI) # Setup the ABI library flags
-
# FIXME(EricWF): See the FIXME on LIBCXX_ENABLE_PEDANTIC.
# Remove the -pedantic flag and -Wno-pedantic and -pedantic-errors
# so they don't get transformed into -Wno and -errors respectively.
@@ -815,7 +833,7 @@ if (DEFINED WIN32 AND LIBCXX_ENABLE_STATIC AND NOT LIBCXX_ENABLE_SHARED)
config_define(ON _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
endif()
-if (WIN32 AND LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
+if (WIN32 AND LIBCXX_CXX_ABI STREQUAL "merged-libcxxabi")
# If linking libcxxabi statically into libcxx, skip the dllimport attributes
# on symbols we refer to from libcxxabi.
add_definitions(-D_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS)
diff --git a/libcxx/cmake/Modules/HandleLibCXXABI.cmake b/libcxx/cmake/Modules/HandleLibCXXABI.cmake
index 52236f473f35de..fa4b761e818021 100644
--- a/libcxx/cmake/Modules/HandleLibCXXABI.cmake
+++ b/libcxx/cmake/Modules/HandleLibCXXABI.cmake
@@ -2,18 +2,10 @@
# Define targets for linking against the selected ABI library
#
# After including this file, the following targets are defined:
-# - libcxx-abi-headers: An interface target that allows getting access to the
-# headers of the selected ABI library.
-# - libcxx-abi-shared: A target representing the selected shared ABI library.
-# - libcxx-abi-static: A target representing the selected static ABI library.
-#
-# Furthermore, some ABI libraries also define the following target:
-# - libcxx-abi-shared-objects: An object library representing a set of object files
-# constituting the ABI library, suitable for bundling
-# into a shared library.
-# - libcxx-abi-static-objects: An object library representing a set of object files
-# constituting the ABI library, suitable for bundling
-# into a static library.
+# - libcxx-abi-shared: A target representing the selected ABI library for linking into
+# the libc++ shared library.
+# - libcxx-abi-static: A target representing the selected ABI library for linking into
+# the libc++ static library.
#===============================================================================
include(GNUInstallDirs)
@@ -29,6 +21,9 @@ include(GNUInstallDirs)
# the search path. Instead, what we do is copy just the ABI library headers to
# a private directory and add just that path when we build libc++.
function(import_private_headers target include_dirs headers)
+ if (NOT ${include_dirs})
+ message(FATAL_ERROR "Missing include paths for the selected ABI library!")
+ endif()
foreach(header ${headers})
set(found FALSE)
foreach(incpath ${include_dirs})
@@ -38,11 +33,11 @@ function(import_private_headers target include_dirs headers)
get_filename_component(dstdir ${header} PATH)
get_filename_component(header_file ${header} NAME)
set(src ${incpath}/${header})
- set(dst "${LIBCXX_BINARY_DIR}/private-abi-headers/${dstdir}/${header_file}")
+ set(dst "${LIBCXX_BINARY_DIR}/private-abi-headers/${target}/${dstdir}/${header_file}")
add_custom_command(OUTPUT ${dst}
DEPENDS ${src}
- COMMAND ${CMAKE_COMMAND} -E make_directory "${LIBCXX_BINARY_DIR}/private-abi-headers/${dstdir}"
+ COMMAND ${CMAKE_COMMAND} -E make_directory "${LIBCXX_BINARY_DIR}/private-abi-headers/${target}/${dstdir}"
COMMAND ${CMAKE_COMMAND} -E copy_if_different ${src} ${dst}
COMMENT "Copying C++ ABI header ${header}")
list(APPEND abilib_headers "${dst}")
@@ -60,7 +55,7 @@ function(import_private_headers target include_dirs headers)
set_target_properties(${target}-generate-private-headers PROPERTIES LINKER_LANGUAGE CXX)
target_link_libraries(${target} INTERFACE ${target}-generate-private-headers)
- target_include_directories(${target} INTERFACE "${LIBCXX_BINARY_DIR}/private-abi-headers")
+ target_include_directories(${target} INTERFACE "${LIBCXX_BINARY_DIR}/private-abi-headers/${target}")
endfunction()
# This function creates an imported static library named <target>.
@@ -74,128 +69,135 @@ function(import_static_library target path name)
set_target_properties(${target} PROPERTIES IMPORTED_LOCATION "${file}")
endfunction()
-# This function creates an imported shared (interface) library named <target>
-# for the given library <name>.
-function(import_shared_library target name)
- add_library(${target} INTERFACE IMPORTED GLOBAL)
- set_target_properties(${target} PROPERTIES IMPORTED_LIBNAME "${name}")
-endfunction()
-
-# Link against a system-provided libstdc++
-if ("${LIBCXX_CXX_ABI}" STREQUAL "libstdc++")
- if(NOT LIBCXX_CXX_ABI_INCLUDE_PATHS)
- message(FATAL_ERROR "LIBCXX_CXX_ABI_INCLUDE_PATHS must be set when selecting libstdc++ as an ABI library")
+# This function creates a library target for linking against an external ABI library.
+#
+# <target>: The name of the target to create
+# <name>: The name of the library file to search for (e.g. c++abi, stdc++, cxxrt, supc++)
+# <type>: Whether to set up a static or a shared library (e.g. SHARED or STATIC)
+# <merged>: Whether to include the ABI library's object files directly into libc++. Only makes sense for a static ABI library.
+function(import_external_abi_library target name type merged)
+ if (${merged} AND "${type}" STREQUAL "SHARED")
+ message(FATAL_ERROR "Can't import an external ABI library for merging when requesting a shared ABI library.")
endif()
- add_library(libcxx-abi-headers INTERFACE)
- import_private_headers(libcxx-abi-headers "${LIBCXX_CXX_ABI_INCLUDE_PATHS}"
- "cxxabi.h;bits/c++config.h;bits/os_defines.h;bits/cpu_defines.h;bits/cxxabi_tweaks.h;bits/cxxabi_forced.h")
- target_compile_definitions(libcxx-abi-headers INTERFACE "-DLIBSTDCXX" "-D__GLIBCXX__")
-
- import_shared_library(libcxx-abi-shared stdc++)
- target_link_libraries(libcxx-abi-shared INTERFACE libcxx-abi-headers)
-
- import_static_library(libcxx-abi-static "${LIBCXX_CXX_ABI_LIBRARY_PATH}" stdc++)
- target_link_libraries(libcxx-abi-static INTERFACE libcxx-abi-headers)
-
-# Link against a system-provided libsupc++
-elseif ("${LIBCXX_CXX_ABI}" STREQUAL "libsupc++")
- if(NOT LIBCXX_CXX_ABI_INCLUDE_PATHS)
- message(FATAL_ERROR "LIBCXX_CXX_ABI_INCLUDE_PATHS must be set when selecting libsupc++ as an ABI library")
+ if ("${type}" STREQUAL "SHARED")
+ add_library(${target} INTERFACE IMPORTED GLOBAL)
+ set_target_properties(${target} PROPERTIES IMPORTED_LIBNAME "${name}")
+ elseif ("${type}" STREQUAL "STATIC")
+ if (${merged})
+ import_static_library(${target}-impl "${LIBCXX_CXX_ABI_LIBRARY_PATH}" ${name})
+ add_library(${target} INTERFACE)
+ if (APPLE)
+ target_link_options(${target} INTERFACE
+ "-Wl,-force_load" "$<TARGET_PROPERTY:${target}-impl,IMPORTED_LOCATION>")
+ else()
+ target_link_options(${target} INTERFACE
+ "-Wl,--whole-archive" "-Wl,-Bstatic"
+ "$<TARGET_PROPERTY:${target}-impl,IMPORTED_LOCATION>"
+ "-Wl,-Bdynamic" "-Wl,--no-whole-archive")
+ endif()
+ else()
+ import_static_library(${target} "${LIBCXX_CXX_ABI_LIBRARY_PATH}" ${name})
+ endif()
endif()
+endfunction()
- add_library(libcxx-abi-headers INTERFACE)
- import_private_headers(libcxx-abi-headers "${LIBCXX_CXX_ABI_INCLUDE_PATHS}"
- "cxxabi.h;bits/c++config.h;bits/os_defines.h;bits/cpu_defines.h;bits/cxxabi_tweaks.h;bits/cxxabi_forced.h")
- target_compile_definitions(libcxx-abi-headers INTERFACE "-D__GLIBCXX__")
-
- import_shared_library(libcxx-abi-shared supc++)
- target_link_libraries(libcxx-abi-shared INTERFACE libcxx-abi-headers)
-
- import_static_library(libcxx-abi-static "${LIBCXX_CXX_ABI_LIBRARY_PATH}" supc++)
- target_link_libraries(libcxx-abi-static INTERFACE libcxx-abi-headers)
-
-# Link against the in-tree libc++abi
-elseif ("${LIBCXX_CXX_ABI}" STREQUAL "libcxxabi")
- add_library(libcxx-abi-headers INTERFACE)
- target_link_libraries(libcxx-abi-headers ...
[truncated]
|
|
@llvm/pr-subscribers-clang Author: Louis Dionne (ldionne) ChangesInstead of having complicated options like LIBCXX_ENABLE_STATIC_ABI_LIBRARY and LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY, introduce a more general mechanism to select the ABI library used by libc++. The new mechanism allows specifying the ABI library for the static libc++ and the shared libc++ separately, and allows selecting a "merged" flavor of libc++ for both the in-tree libc++abi and any external static ABI library. As an example, one can now specify arbitrary combinations like which would have been impossible or very brittle in the past. In theory, one can even select an entirely different ABI library for the static and the shared libc++ (e.g. libc++abi vs libsupc++), although supporting that is not a primary goal of this patch but merely a result of the general mechanism. Closes #77655 Differential Revision: https://reviews.llvm.org/D125683 Patch is 42.33 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/112978.diff 18 Files Affected:
diff --git a/clang/cmake/caches/Android.cmake b/clang/cmake/caches/Android.cmake
index d5ca6b50d4ada7..dbf66539591394 100644
--- a/clang/cmake/caches/Android.cmake
+++ b/clang/cmake/caches/Android.cmake
@@ -21,8 +21,8 @@ if (LIBCXX_ENABLE_ABI_LINKER_SCRIPT)
list(APPEND EXTRA_ARGS -DLIBCXX_ENABLE_ABI_LINKER_SCRIPT=${LIBCXX_ENABLE_ABI_LINKER_SCRIPT})
endif()
-if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
- list(APPEND EXTRA_ARGS -DLIBCXX_ENABLE_STATIC_ABI_LIBRARY=${LIBCXX_ENABLE_STATIC_ABI_LIBRARY})
+if (LIBCXX_CXX_ABI)
+ list(APPEND EXTRA_ARGS -DLIBCXX_CXX_ABI=${LIBCXX_CXX_ABI})
endif()
if (LLVM_BUILD_EXTERNAL_COMPILER_RT)
diff --git a/clang/cmake/caches/CrossWinToARMLinux.cmake b/clang/cmake/caches/CrossWinToARMLinux.cmake
index 87118bbd33377d..15341aeb283801 100644
--- a/clang/cmake/caches/CrossWinToARMLinux.cmake
+++ b/clang/cmake/caches/CrossWinToARMLinux.cmake
@@ -215,10 +215,8 @@ set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXXABI_ENABLE_SHARED
set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ENABLE_SHARED ${TOOLCHAIN_SHARED_LIBS} CACHE BOOL "")
set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ABI_VERSION ${LIBCXX_ABI_VERSION} CACHE STRING "")
-set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_CXX_ABI "libcxxabi" CACHE STRING "") #!!!
+set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_CXX_ABI "merged-libcxxabi" CACHE STRING "") #!!!
set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ENABLE_NEW_DELETE_DEFINITIONS ON CACHE BOOL "")
-# Merge libc++ and libc++abi libraries into the single libc++ library file.
-set(RUNTIMES_${TOOLCHAIN_TARGET_TRIPLE}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
# Avoid searching for the python3 interpreter during the runtimes configuration for the cross builds.
# It starts searching the python3 package using the target's sysroot path, that usually is not compatible with the build host.
diff --git a/clang/cmake/caches/Fuchsia-stage2.cmake b/clang/cmake/caches/Fuchsia-stage2.cmake
index 5af98c7b3b3fba..761a31e486ad34 100644
--- a/clang/cmake/caches/Fuchsia-stage2.cmake
+++ b/clang/cmake/caches/Fuchsia-stage2.cmake
@@ -83,7 +83,7 @@ if(APPLE)
set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
set(LIBCXX_ABI_VERSION 2 CACHE STRING "")
set(LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
- set(LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
+ set(LIBCXX_CXX_ABI "merged-libcxxabi" CACHE STRING "")
set(LIBCXX_HARDENING_MODE "none" CACHE STRING "")
set(LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
set(RUNTIMES_CMAKE_ARGS "-DCMAKE_OSX_DEPLOYMENT_TARGET=10.13;-DCMAKE_OSX_ARCHITECTURES=arm64|x86_64" CACHE STRING "")
@@ -180,9 +180,9 @@ foreach(target aarch64-unknown-linux-gnu;armv7-unknown-linux-gnueabihf;i386-unkn
set(RUNTIMES_${target}_LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
+ set(RUNTIMES_${target}_LIBCXX_CXX_ABI "merged-libcxxabi" CACHE STRING "")
set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
- set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")
set(RUNTIMES_${target}_SANITIZER_CXX_ABI "libc++" CACHE STRING "")
@@ -244,10 +244,10 @@ if(FUCHSIA_SDK)
set(RUNTIMES_${target}_LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXXABI_HERMETIC_STATIC_LIBRARY ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXXABI_INSTALL_STATIC_LIBRARY OFF CACHE BOOL "")
+ set(RUNTIMES_${target}_LIBCXX_ABILIB_FOR_STATIC "merged-libcxxabi" CACHE STRING "")
+ set(RUNTIMES_${target}_LIBCXX_ABILIB_FOR_SHARED "shared-libcxxabi" CACHE STRING "")
set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
- set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_HERMETIC_STATIC_LIBRARY ON CACHE BOOL "")
- set(RUNTIMES_${target}_LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY OFF CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")
set(RUNTIMES_${target}_LLVM_ENABLE_RUNTIMES "compiler-rt;libcxx;libcxxabi;libunwind" CACHE STRING "")
diff --git a/clang/cmake/caches/Fuchsia.cmake b/clang/cmake/caches/Fuchsia.cmake
index 2d2dcb9ae6798d..5e31fe4fdd33df 100644
--- a/clang/cmake/caches/Fuchsia.cmake
+++ b/clang/cmake/caches/Fuchsia.cmake
@@ -109,6 +109,7 @@ endif()
if(WIN32)
set(LIBCXX_ABI_VERSION 2 CACHE STRING "")
+ set(LIBCXX_CXX_ABI "merged-libcxxabi" CACHE STRING "")
set(LIBCXX_ENABLE_ABI_LINKER_SCRIPT OFF CACHE BOOL "")
set(LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
set(BUILTINS_CMAKE_ARGS -DCMAKE_SYSTEM_NAME=Windows CACHE STRING "")
@@ -125,7 +126,6 @@ else()
set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
set(LIBCXX_ABI_VERSION 2 CACHE STRING "")
set(LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
- set(LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
set(LIBCXX_HARDENING_MODE "none" CACHE STRING "")
set(LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
set(LLVM_ENABLE_RUNTIMES "compiler-rt;libcxx;libcxxabi;libunwind" CACHE STRING "")
@@ -155,8 +155,8 @@ if(BOOTSTRAP_CMAKE_SYSTEM_NAME)
set(RUNTIMES_${target}_LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
- set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
+ set(RUNTIMES_${target}_LIBCXX_CXX_ABI "merged-libcxxabi" CACHE STRING "")
set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")
set(RUNTIMES_${target}_LLVM_ENABLE_RUNTIMES "compiler-rt;libcxx;libcxxabi;libunwind" CACHE STRING "")
set(RUNTIMES_${target}_SANITIZER_CXX_ABI "libc++" CACHE STRING "")
diff --git a/compiler-rt/cmake/Modules/AddCompilerRT.cmake b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
index e3d81d241b1054..5dec0face88ca5 100644
--- a/compiler-rt/cmake/Modules/AddCompilerRT.cmake
+++ b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
@@ -696,12 +696,11 @@ macro(add_custom_libcxx name prefix)
-DLIBCXXABI_ENABLE_SHARED=OFF
-DLIBCXXABI_HERMETIC_STATIC_LIBRARY=ON
-DLIBCXXABI_INCLUDE_TESTS=OFF
- -DLIBCXX_CXX_ABI=libcxxabi
+ -DLIBCXX_CXX_ABI="merged-libcxxabi"
-DLIBCXX_ENABLE_SHARED=OFF
-DLIBCXX_HERMETIC_STATIC_LIBRARY=ON
-DLIBCXX_INCLUDE_BENCHMARKS=OFF
-DLIBCXX_INCLUDE_TESTS=OFF
- -DLIBCXX_ENABLE_STATIC_ABI_LIBRARY=ON
${LIBCXX_CMAKE_ARGS}
INSTALL_COMMAND ""
STEP_TARGETS configure build
diff --git a/libcxx/CMakeLists.txt b/libcxx/CMakeLists.txt
index 574b262018cd3a..22853ca982af5f 100644
--- a/libcxx/CMakeLists.txt
+++ b/libcxx/CMakeLists.txt
@@ -230,11 +230,22 @@ else()
endif()
set(LIBCXX_SUPPORTED_ABI_LIBRARIES none libcxxabi system-libcxxabi libcxxrt libstdc++ libsupc++ vcruntime)
-set(LIBCXX_CXX_ABI "${LIBCXX_DEFAULT_ABI_LIBRARY}" CACHE STRING "Specify C++ ABI library to use. Supported values are ${LIBCXX_SUPPORTED_ABI_LIBRARIES}.")
-if (NOT "${LIBCXX_CXX_ABI}" IN_LIST LIBCXX_SUPPORTED_ABI_LIBRARIES)
- message(FATAL_ERROR "Unsupported C++ ABI library: '${LIBCXX_CXX_ABI}'. Supported values are ${LIBCXX_SUPPORTED_ABI_LIBRARIES}.")
-endif()
-
+set(LIBCXX_CXX_ABI "${LIBCXX_DEFAULT_ABI_LIBRARY}" CACHE STRING
+ "Specify the C++ ABI library to use for the shared and the static libc++ libraries. Supported values are ${LIBCXX_SUPPORTED_ABI_LIBRARIES}.
+ This CMake option also supports \"consumption specifiers\", which specify how the selected ABI library should be consumed by
+ libc++. The supported specifiers are:
+ - `shared`: The selected ABI library should be used as a shared library.
+ - `static`: The selected ABI library should be used as a static library.
+ - `merged`: The selected ABI library should be a static library whose object files will be merged directly into the produced libc++ library.
+
+ A consumption specifier is provided by appending it to the name of the library, such as `LIBCXX_CXX_ABI=merged-libcxxabi`.
+ If no consumption specifier is provided, the libc++ shared library will default to using a shared ABI library, and the
+ libc++ static library will default to using a static ABI library.")
+set(LIBCXX_ABILIB_FOR_SHARED "${LIBCXX_CXX_ABI}" CACHE STRING "C++ ABI library to use for the shared libc++ library.")
+set(LIBCXX_ABILIB_FOR_STATIC "${LIBCXX_CXX_ABI}" CACHE STRING "C++ ABI library to use for the static libc++ library.")
+
+#############################
+# TODO: Remove these options in LLVM 21.
option(LIBCXX_ENABLE_STATIC_ABI_LIBRARY
"Use a static copy of the ABI library when linking libc++.
This option cannot be used with LIBCXX_ENABLE_ABI_LINKER_SCRIPT." OFF)
@@ -247,17 +258,34 @@ option(LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY
"Statically link the ABI library to shared library"
${LIBCXX_ENABLE_STATIC_ABI_LIBRARY})
+if (LIBCXX_ENABLE_STATIC_ABI_LIBRARY OR LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY OR LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY)
+ message(WARNING "The LIBCXX_ENABLE_STATIC_ABI_LIBRARY, LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY and "
+ "LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY options have been deprecated in favor of "
+ "using LIBCXX_CXX_ABI=merged-libcxxabi. This will become an error in LLVM 21.")
+endif()
+if (LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY)
+ set(LIBCXX_ABILIB_FOR_STATIC "merged-libcxxabi" CACHE STRING "" FORCE)
+endif()
+if (LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY)
+ set(LIBCXX_ABILIB_FOR_SHARED "merged-libcxxabi" CACHE STRING "" FORCE)
+endif()
+#############################
+
# Generate and install a linker script inplace of libc++.so. The linker script
# will link libc++ to the correct ABI library. This option is on by default
-# on UNIX platforms other than Apple, and on the Fuchsia platform unless we
-# statically link libc++abi inside libc++.so, we don't build libc++.so at all
-# or we don't have any ABI library.
-if (LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY
- OR NOT LIBCXX_ENABLE_SHARED
- OR LIBCXX_CXX_ABI STREQUAL "none")
- set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE OFF)
-elseif((UNIX OR FUCHSIA) AND NOT APPLE)
- set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE ON)
+# on UNIX platforms other than Apple unless we are linking the ABI library as
+# an object library. This option is also disabled when the ABI library is not
+# specified or is specified to be "none".
+if(LIBCXX_ENABLE_SHARED)
+ if ((UNIX OR FUCHSIA) AND NOT APPLE)
+ if (LIBCXX_ABILIB_FOR_SHARED STREQUAL "merged-libcxxabi" OR LIBCXX_ABILIB_FOR_SHARED STREQUAL "none")
+ set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE OFF)
+ else()
+ set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE ON)
+ endif()
+ else()
+ set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE OFF)
+ endif()
else()
set(ENABLE_LINKER_SCRIPT_DEFAULT_VALUE OFF)
endif()
@@ -379,12 +407,6 @@ if (LIBCXX_ENABLE_ABI_LINKER_SCRIPT)
endif()
endif()
-if (LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY AND LIBCXX_ENABLE_ABI_LINKER_SCRIPT)
- message(FATAL_ERROR "Conflicting options given.
- LIBCXX_STATICALLY_LINK_ABI_IN_SHARED_LIBRARY cannot be specified with
- LIBCXX_ENABLE_ABI_LINKER_SCRIPT")
-endif()
-
if (LIBCXX_ABI_FORCE_ITANIUM AND LIBCXX_ABI_FORCE_MICROSOFT)
message(FATAL_ERROR "Only one of LIBCXX_ABI_FORCE_ITANIUM and LIBCXX_ABI_FORCE_MICROSOFT can be specified.")
endif ()
@@ -481,10 +503,6 @@ include(config-ix)
#===============================================================================
# Setup Compiler Flags
#===============================================================================
-
-include(HandleLibC) # Setup the C library flags
-include(HandleLibCXXABI) # Setup the ABI library flags
-
# FIXME(EricWF): See the FIXME on LIBCXX_ENABLE_PEDANTIC.
# Remove the -pedantic flag and -Wno-pedantic and -pedantic-errors
# so they don't get transformed into -Wno and -errors respectively.
@@ -815,7 +833,7 @@ if (DEFINED WIN32 AND LIBCXX_ENABLE_STATIC AND NOT LIBCXX_ENABLE_SHARED)
config_define(ON _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
endif()
-if (WIN32 AND LIBCXX_ENABLE_STATIC_ABI_LIBRARY)
+if (WIN32 AND LIBCXX_CXX_ABI STREQUAL "merged-libcxxabi")
# If linking libcxxabi statically into libcxx, skip the dllimport attributes
# on symbols we refer to from libcxxabi.
add_definitions(-D_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS)
diff --git a/libcxx/cmake/Modules/HandleLibCXXABI.cmake b/libcxx/cmake/Modules/HandleLibCXXABI.cmake
index 52236f473f35de..fa4b761e818021 100644
--- a/libcxx/cmake/Modules/HandleLibCXXABI.cmake
+++ b/libcxx/cmake/Modules/HandleLibCXXABI.cmake
@@ -2,18 +2,10 @@
# Define targets for linking against the selected ABI library
#
# After including this file, the following targets are defined:
-# - libcxx-abi-headers: An interface target that allows getting access to the
-# headers of the selected ABI library.
-# - libcxx-abi-shared: A target representing the selected shared ABI library.
-# - libcxx-abi-static: A target representing the selected static ABI library.
-#
-# Furthermore, some ABI libraries also define the following target:
-# - libcxx-abi-shared-objects: An object library representing a set of object files
-# constituting the ABI library, suitable for bundling
-# into a shared library.
-# - libcxx-abi-static-objects: An object library representing a set of object files
-# constituting the ABI library, suitable for bundling
-# into a static library.
+# - libcxx-abi-shared: A target representing the selected ABI library for linking into
+# the libc++ shared library.
+# - libcxx-abi-static: A target representing the selected ABI library for linking into
+# the libc++ static library.
#===============================================================================
include(GNUInstallDirs)
@@ -29,6 +21,9 @@ include(GNUInstallDirs)
# the search path. Instead, what we do is copy just the ABI library headers to
# a private directory and add just that path when we build libc++.
function(import_private_headers target include_dirs headers)
+ if (NOT ${include_dirs})
+ message(FATAL_ERROR "Missing include paths for the selected ABI library!")
+ endif()
foreach(header ${headers})
set(found FALSE)
foreach(incpath ${include_dirs})
@@ -38,11 +33,11 @@ function(import_private_headers target include_dirs headers)
get_filename_component(dstdir ${header} PATH)
get_filename_component(header_file ${header} NAME)
set(src ${incpath}/${header})
- set(dst "${LIBCXX_BINARY_DIR}/private-abi-headers/${dstdir}/${header_file}")
+ set(dst "${LIBCXX_BINARY_DIR}/private-abi-headers/${target}/${dstdir}/${header_file}")
add_custom_command(OUTPUT ${dst}
DEPENDS ${src}
- COMMAND ${CMAKE_COMMAND} -E make_directory "${LIBCXX_BINARY_DIR}/private-abi-headers/${dstdir}"
+ COMMAND ${CMAKE_COMMAND} -E make_directory "${LIBCXX_BINARY_DIR}/private-abi-headers/${target}/${dstdir}"
COMMAND ${CMAKE_COMMAND} -E copy_if_different ${src} ${dst}
COMMENT "Copying C++ ABI header ${header}")
list(APPEND abilib_headers "${dst}")
@@ -60,7 +55,7 @@ function(import_private_headers target include_dirs headers)
set_target_properties(${target}-generate-private-headers PROPERTIES LINKER_LANGUAGE CXX)
target_link_libraries(${target} INTERFACE ${target}-generate-private-headers)
- target_include_directories(${target} INTERFACE "${LIBCXX_BINARY_DIR}/private-abi-headers")
+ target_include_directories(${target} INTERFACE "${LIBCXX_BINARY_DIR}/private-abi-headers/${target}")
endfunction()
# This function creates an imported static library named <target>.
@@ -74,128 +69,135 @@ function(import_static_library target path name)
set_target_properties(${target} PROPERTIES IMPORTED_LOCATION "${file}")
endfunction()
-# This function creates an imported shared (interface) library named <target>
-# for the given library <name>.
-function(import_shared_library target name)
- add_library(${target} INTERFACE IMPORTED GLOBAL)
- set_target_properties(${target} PROPERTIES IMPORTED_LIBNAME "${name}")
-endfunction()
-
-# Link against a system-provided libstdc++
-if ("${LIBCXX_CXX_ABI}" STREQUAL "libstdc++")
- if(NOT LIBCXX_CXX_ABI_INCLUDE_PATHS)
- message(FATAL_ERROR "LIBCXX_CXX_ABI_INCLUDE_PATHS must be set when selecting libstdc++ as an ABI library")
+# This function creates a library target for linking against an external ABI library.
+#
+# <target>: The name of the target to create
+# <name>: The name of the library file to search for (e.g. c++abi, stdc++, cxxrt, supc++)
+# <type>: Whether to set up a static or a shared library (e.g. SHARED or STATIC)
+# <merged>: Whether to include the ABI library's object files directly into libc++. Only makes sense for a static ABI library.
+function(import_external_abi_library target name type merged)
+ if (${merged} AND "${type}" STREQUAL "SHARED")
+ message(FATAL_ERROR "Can't import an external ABI library for merging when requesting a shared ABI library.")
endif()
- add_library(libcxx-abi-headers INTERFACE)
- import_private_headers(libcxx-abi-headers "${LIBCXX_CXX_ABI_INCLUDE_PATHS}"
- "cxxabi.h;bits/c++config.h;bits/os_defines.h;bits/cpu_defines.h;bits/cxxabi_tweaks.h;bits/cxxabi_forced.h")
- target_compile_definitions(libcxx-abi-headers INTERFACE "-DLIBSTDCXX" "-D__GLIBCXX__")
-
- import_shared_library(libcxx-abi-shared stdc++)
- target_link_libraries(libcxx-abi-shared INTERFACE libcxx-abi-headers)
-
- import_static_library(libcxx-abi-static "${LIBCXX_CXX_ABI_LIBRARY_PATH}" stdc++)
- target_link_libraries(libcxx-abi-static INTERFACE libcxx-abi-headers)
-
-# Link against a system-provided libsupc++
-elseif ("${LIBCXX_CXX_ABI}" STREQUAL "libsupc++")
- if(NOT LIBCXX_CXX_ABI_INCLUDE_PATHS)
- message(FATAL_ERROR "LIBCXX_CXX_ABI_INCLUDE_PATHS must be set when selecting libsupc++ as an ABI library")
+ if ("${type}" STREQUAL "SHARED")
+ add_library(${target} INTERFACE IMPORTED GLOBAL)
+ set_target_properties(${target} PROPERTIES IMPORTED_LIBNAME "${name}")
+ elseif ("${type}" STREQUAL "STATIC")
+ if (${merged})
+ import_static_library(${target}-impl "${LIBCXX_CXX_ABI_LIBRARY_PATH}" ${name})
+ add_library(${target} INTERFACE)
+ if (APPLE)
+ target_link_options(${target} INTERFACE
+ "-Wl,-force_load" "$<TARGET_PROPERTY:${target}-impl,IMPORTED_LOCATION>")
+ else()
+ target_link_options(${target} INTERFACE
+ "-Wl,--whole-archive" "-Wl,-Bstatic"
+ "$<TARGET_PROPERTY:${target}-impl,IMPORTED_LOCATION>"
+ "-Wl,-Bdynamic" "-Wl,--no-whole-archive")
+ endif()
+ else()
+ import_static_library(${target} "${LIBCXX_CXX_ABI_LIBRARY_PATH}" ${name})
+ endif()
endif()
+endfunction()
- add_library(libcxx-abi-headers INTERFACE)
- import_private_headers(libcxx-abi-headers "${LIBCXX_CXX_ABI_INCLUDE_PATHS}"
- "cxxabi.h;bits/c++config.h;bits/os_defines.h;bits/cpu_defines.h;bits/cxxabi_tweaks.h;bits/cxxabi_forced.h")
- target_compile_definitions(libcxx-abi-headers INTERFACE "-D__GLIBCXX__")
-
- import_shared_library(libcxx-abi-shared supc++)
- target_link_libraries(libcxx-abi-shared INTERFACE libcxx-abi-headers)
-
- import_static_library(libcxx-abi-static "${LIBCXX_CXX_ABI_LIBRARY_PATH}" supc++)
- target_link_libraries(libcxx-abi-static INTERFACE libcxx-abi-headers)
-
-# Link against the in-tree libc++abi
-elseif ("${LIBCXX_CXX_ABI}" STREQUAL "libcxxabi")
- add_library(libcxx-abi-headers INTERFACE)
- target_link_libraries(libcxx-abi-headers ...
[truncated]
|
|
The original review in https://reviews.llvm.org/D125683 had a some comments, mainly the fact that:
Both of these shortcomings have been addressed in this version of the patch. |
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|
Looking at our current cmake config, we're using: Do I understand correctly that the new replacement for that would be? And those LIBCXX_ABILIB options are also the defaults, if I'm reading the docs right. |
Yes, that is correct. This patch should be changing your CMake config as well, unless that config is not visible in the monorepo (or if I missed it).
Not quite. |
It's out of tree :)
I see, thanks. I didn't look into this in detail, but the high level design here makes sense to me, and addresses the concerns I had with the previous iteration of the patch. |
|
@petrhosek I'm curious to know what you think of this design. |
petrhosek
reviewed
Nov 5, 2024
| libc++. The supported specifiers are: | ||
| - `shared`: The selected ABI library should be used as a shared library. | ||
| - `static`: The selected ABI library should be used as a static library. | ||
| - `merged`: The selected ABI library should be a static library whose object files will be merged directly into the produced libc++ library. |
There was a problem hiding this comment.
This is just bikeshedding, but have you considered object rather than merged?
There was a problem hiding this comment.
I did, in fact I started with that but eventually renamed it to merged since it's not necessarily implemented with CMake object libraries. Possibilities:
merged-libcxxabi
object-libcxxabi
Or we can swap it around and have this instead:
libcxxabi-merged
libcxxabi-objects
IMO merged makes more sense than object because for e.g. libsupcxx-objects it makes it look as-if we were using the object files of the library, when in reality we're using the static archive and merging it into our dylib (in practice I guess those are the same thing under the hood, but I have a different mental model).
petrhosek
reviewed
Nov 5, 2024
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…LIBCXX_CXX_ABI choice Instead of having complicated options like LIBCXX_ENABLE_STATIC_ABI_LIBRARY and LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY, introduce a more general mechanism to select the ABI library used by libc++. The new mechanism allows specifying the ABI library for the static libc++ and the shared libc++ separately, and allows selecting a "merged" flavor of libc++ for both the in-tree libc++abi and any external static ABI library. As an example, one can now specify arbitrary combinations like -DLIBCXX_ABILIB_FOR_SHARED="shared-libcxxabi" -DLIBCXX_ABILIB_FOR_STATIC="merged-libcxxabi" which would have been impossible or very brittle in the past. In theory, one can even select an entirely different ABI library for the static and the shared libc++ (e.g. libc++abi vs libsupc++), although supporting that is not a primary goal of this patch but merely a result of the general mechanism. Closes llvm#77655 Fixes llvm#57759 Differential Revision: https://reviews.llvm.org/D125683
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Instead of having complicated options like LIBCXX_ENABLE_STATIC_ABI_LIBRARY and LIBCXX_STATICALLY_LINK_ABI_IN_STATIC_LIBRARY, introduce a more general mechanism to select the ABI library used by libc++. The new mechanism allows specifying the ABI library for the static libc++ and the shared libc++ separately, and allows selecting a "merged" flavor of libc++ for both the in-tree libc++abi and any external static ABI library.
As an example, one can now specify arbitrary combinations like
-DLIBCXX_ABILIB_FOR_SHARED="shared-libcxxabi"
-DLIBCXX_ABILIB_FOR_STATIC="merged-libcxxabi"
which would have been impossible or very brittle in the past. In theory, one can even select an entirely different ABI library for the static and the shared libc++ (e.g. libc++abi vs libsupc++), although supporting that is not a primary goal of this patch but merely a result of the general mechanism.
Closes #77655
Fixes #57759
Differential Revision: https://reviews.llvm.org/D125683