ldionne created this revision.
ldionne added a reviewer: Mordante.
Herald added subscribers: Enna1, abrachet, arichardson, mgorny.
Herald added a project: All.
ldionne requested review of this revision.
Herald added projects: clang, Sanitizers, libc++.
Herald added subscribers: libcxx-commits, Sanitizers, cfe-commits.
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This is the first part of a plan to ship experimental features
by default while guarding them behind a compiler flag to avoid
users accidentally depending on them. Subsequent patches will
also encompass incomplete features (such as <format> and <ranges>)
in that categorization.
Note that this patch intentionally does not start guarding
existing <experimental/FOO> content behind the flag, because
that would merely break users that might be relying on such
content being in the headers unconditionally. Instead, we
should start guarding new TSes behind the flag, and get rid
of the existing TSes we have by shipping their Standard
counterpart.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D128927
Files:
clang/cmake/caches/Fuchsia-stage2.cmake
clang/cmake/caches/Fuchsia.cmake
compiler-rt/cmake/Modules/AddCompilerRT.cmake
libcxx/CMakeLists.txt
libcxx/appveyor.yml
libcxx/cmake/caches/AIX.cmake
libcxx/cmake/caches/Apple.cmake
libcxx/cmake/caches/Generic-no-experimental.cmake
libcxx/cmake/caches/MinGW.cmake
libcxx/docs/BuildingLibcxx.rst
libcxx/docs/ReleaseNotes.rst
libcxx/docs/UsingLibcxx.rst
libcxx/src/CMakeLists.txt
libcxx/test/CMakeLists.txt
libcxx/utils/ci/run-buildbot
libcxx/utils/libcxx/test/params.py
Index: libcxx/utils/libcxx/test/params.py
===================================================================
--- libcxx/utils/libcxx/test/params.py
+++ libcxx/utils/libcxx/test/params.py
@@ -62,6 +62,13 @@
return '-std='+fallbacks[std]
return None
+# TODO: Remove this once all the compilers we support understand `-funstable`
+def getUnstableFlag(cfg):
+ if hasCompileFlag(cfg, '-funstable'):
+ return '-funstable'
+ else:
+ return '-D_LIBCPP_ENABLE_EXPERIMENTAL -lc++experimental'
+
DEFAULT_PARAMETERS = [
Parameter(name='target_triple', type=str,
help="The target triple to compile the test suite for. This must be "
@@ -156,15 +163,10 @@
])),
Parameter(name='enable_experimental', choices=[True, False], type=bool, default=True,
- help="Whether to enable tests for experimental C++ libraries (typically Library Fundamentals TSes).",
+ help="Whether to enable tests for experimental C++ Library features.",
actions=lambda experimental: [] if not experimental else [
+ AddCompileFlag(getUnstableFlag),
AddFeature('c++experimental'),
- # When linking in MSVC mode via the Clang driver, a -l<foo>
- # maps to <foo>.lib, so we need to use -llibc++experimental here
- # to make it link against the static libc++experimental.lib.
- # We can't check for the feature 'msvc' in available_features
- # as those features are added after processing parameters.
- PrependLinkFlag(lambda config: '-llibc++experimental' if _isMSVC(config) else '-lc++experimental')
]),
Parameter(name='long_tests', choices=[True, False], type=bool, default=True,
Index: libcxx/utils/ci/run-buildbot
===================================================================
--- libcxx/utils/ci/run-buildbot
+++ libcxx/utils/ci/run-buildbot
@@ -517,13 +517,7 @@
;;
clang-cl-dll)
clean
- # TODO: Currently, building with the experimental library breaks running
- # tests (the test linking look for the c++experimental library with the
- # wrong name, and the statically linked c++experimental can't be linked
- # correctly when libc++ visibility attributes indicate dllimport linkage
- # anyway), thus just disable the experimental library. Remove this
- # setting when cmake and the test driver does the right thing automatically.
- generate-cmake-libcxx-win -DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY=OFF
+ generate-cmake-libcxx-win
echo "+++ Running the libc++ tests"
${NINJA} -vC "${BUILD_DIR}" check-cxx
;;
Index: libcxx/test/CMakeLists.txt
===================================================================
--- libcxx/test/CMakeLists.txt
+++ libcxx/test/CMakeLists.txt
@@ -93,10 +93,6 @@
serialize_lit_param(enable_exceptions False)
endif()
-if (NOT LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY)
- serialize_lit_param(enable_experimental False)
-endif()
-
if (NOT LIBCXX_ENABLE_RTTI)
serialize_lit_param(enable_rtti False)
endif()
Index: libcxx/src/CMakeLists.txt
===================================================================
--- libcxx/src/CMakeLists.txt
+++ libcxx/src/CMakeLists.txt
@@ -315,25 +315,23 @@
# Add a meta-target for both libraries.
add_custom_target(cxx DEPENDS ${LIBCXX_BUILD_TARGETS})
-if (LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY)
- set(LIBCXX_EXPERIMENTAL_SOURCES
- experimental/memory_resource.cpp
- )
- add_library(cxx_experimental STATIC ${LIBCXX_EXPERIMENTAL_SOURCES})
- if (LIBCXX_ENABLE_SHARED)
- target_link_libraries(cxx_experimental PRIVATE cxx_shared)
- else()
- target_link_libraries(cxx_experimental PRIVATE cxx_static)
- endif()
-
- set_target_properties(cxx_experimental
- PROPERTIES
- COMPILE_FLAGS "${LIBCXX_COMPILE_FLAGS}"
- OUTPUT_NAME "c++experimental"
+set(LIBCXX_EXPERIMENTAL_SOURCES
+ experimental/memory_resource.cpp
)
- cxx_add_common_build_flags(cxx_experimental)
+add_library(cxx_experimental STATIC ${LIBCXX_EXPERIMENTAL_SOURCES})
+if (LIBCXX_ENABLE_SHARED)
+ target_link_libraries(cxx_experimental PRIVATE cxx_shared)
+else()
+ target_link_libraries(cxx_experimental PRIVATE cxx_static)
endif()
+set_target_properties(cxx_experimental
+ PROPERTIES
+ COMPILE_FLAGS "${LIBCXX_COMPILE_FLAGS}"
+ OUTPUT_NAME "c++experimental"
+)
+cxx_add_common_build_flags(cxx_experimental)
+
if (LIBCXX_BUILD_EXTERNAL_THREAD_LIBRARY)
set(LIBCXX_EXTERNAL_THREADING_SUPPORT_SOURCES
@@ -369,7 +367,7 @@
RUNTIME DESTINATION ${LIBCXX_INSTALL_RUNTIME_DIR} COMPONENT cxx)
endif()
-if(LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY)
+if (LIBCXX_INSTALL_LIBRARY)
install(TARGETS cxx_experimental
LIBRARY DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
ARCHIVE DESTINATION ${LIBCXX_INSTALL_LIBRARY_DIR} COMPONENT cxx
@@ -386,10 +384,7 @@
if (NOT CMAKE_CONFIGURATION_TYPES)
if(LIBCXX_INSTALL_LIBRARY)
- set(lib_install_target cxx)
- endif()
- if (LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY)
- set(experimental_lib_install_target cxx_experimental)
+ set(lib_install_target "cxx;cxx_experimental")
endif()
if(LIBCXX_INSTALL_HEADERS)
set(header_install_target install-cxx-headers)
@@ -399,7 +394,7 @@
endif()
add_custom_target(install-cxx
DEPENDS ${lib_install_target}
- ${experimental_lib_install_target}
+ cxx_experimental
${header_install_target}
${pstl_install_target}
COMMAND "${CMAKE_COMMAND}"
@@ -407,7 +402,7 @@
-P "${LIBCXX_BINARY_DIR}/cmake_install.cmake")
add_custom_target(install-cxx-stripped
DEPENDS ${lib_install_target}
- ${experimental_lib_install_target}
+ cxx_experimental
${header_install_target}
${pstl_install_target}
COMMAND "${CMAKE_COMMAND}"
Index: libcxx/docs/UsingLibcxx.rst
===================================================================
--- libcxx/docs/UsingLibcxx.rst
+++ libcxx/docs/UsingLibcxx.rst
@@ -34,22 +34,16 @@
library until the standard has been ratified.
-Using libc++experimental and ``<experimental/...>``
-===================================================
+Enabling experimental C++ Library features
+==========================================
-Libc++ provides implementations of experimental technical specifications
-in a separate library, ``libc++experimental.a``. Users of ``<experimental/...>``
-headers may be required to link ``-lc++experimental``. Note that not all
-vendors ship ``libc++experimental.a``, and as a result, you may not be
-able to use those experimental features.
-
-.. code-block:: bash
-
- $ clang++ test.cpp -lc++experimental
+Libc++ provides implementations of some experimental features. Those are disabled by
+default because they are neither API nor ABI stable. However, the Clang flag ``-funstable``
+can be used to turn those features on.
.. warning::
Experimental libraries are Experimental.
- * The contents of the ``<experimental/...>`` headers and ``libc++experimental.a``
+ * The contents of the ``<experimental/...>`` headers and the associated static
library will not remain compatible between versions.
* No guarantees of API or ABI stability are provided.
* When the standardized version of an experimental feature is implemented,
Index: libcxx/docs/ReleaseNotes.rst
===================================================================
--- libcxx/docs/ReleaseNotes.rst
+++ libcxx/docs/ReleaseNotes.rst
@@ -219,3 +219,8 @@
means that the same set of installed headers works for both DLL and static
linkage. This means that distributors finally can build both library
versions with a single CMake invocation.
+
+- The ``c++experimental.a`` library is now always built and included alongside the usual
+ libc++ library. Users must pass the ``-funstable`` compiler flag in order to use the
+ experimental features provided by it. Note that vendors are encouraged to ship the
+ experimental library now that the compiler provides an ergonomic way to use it.
Index: libcxx/docs/BuildingLibcxx.rst
===================================================================
--- libcxx/docs/BuildingLibcxx.rst
+++ libcxx/docs/BuildingLibcxx.rst
@@ -99,8 +99,7 @@
-T "ClangCL" ^
-DLLVM_ENABLE_RUNTIMES=libcxx ^
-DLIBCXX_ENABLE_SHARED=YES ^
- -DLIBCXX_ENABLE_STATIC=NO ^
- -DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY=NO
+ -DLIBCXX_ENABLE_STATIC=NO
> cmake --build build
CMake + ninja (MSVC)
@@ -131,8 +130,7 @@
> cmake -G Ninja -S runtimes -B build ^
-DCMAKE_C_COMPILER=clang-cl ^
-DCMAKE_CXX_COMPILER=clang-cl ^
- -DLLVM_ENABLE_RUNTIMES=libcxx ^
- -DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY=NO
+ -DLLVM_ENABLE_RUNTIMES=libcxx
> ninja -C build cxx
> ninja -C build check-cxx
@@ -298,23 +296,6 @@
Path where target-specific libc++ headers should be installed. If a relative
path, relative to ``CMAKE_INSTALL_PREFIX``.
-.. _libc++experimental options:
-
-libc++experimental Specific Options
-------------------------------------
-
-.. option:: LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY:BOOL
-
- **Default**: ``ON``
-
- Build and test libc++experimental.a.
-
-.. option:: LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY:BOOL
-
- **Default**: ``LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY AND LIBCXX_INSTALL_LIBRARY``
-
- Install libc++experimental.a alongside libc++.
-
.. _ABI Library Specific Options:
Index: libcxx/cmake/caches/MinGW.cmake
===================================================================
--- libcxx/cmake/caches/MinGW.cmake
+++ libcxx/cmake/caches/MinGW.cmake
@@ -1,5 +1,3 @@
-set(LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY OFF CACHE BOOL "")
-
set(LIBCXX_CXX_ABI libcxxabi CACHE STRING "")
set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
Index: libcxx/cmake/caches/Generic-no-experimental.cmake
===================================================================
--- libcxx/cmake/caches/Generic-no-experimental.cmake
+++ libcxx/cmake/caches/Generic-no-experimental.cmake
@@ -1,2 +1,3 @@
-set(LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY OFF CACHE BOOL "")
+set(LIBCXX_TEST_PARAMS "enable_experimental=False" CACHE STRING "")
+set(LIBCXXABI_TEST_PARAMS "${LIBCXX_TEST_PARAMS}" CACHE STRING "")
set(LIBCXX_ENABLE_INCOMPLETE_FEATURES OFF CACHE BOOL "")
Index: libcxx/cmake/caches/Apple.cmake
===================================================================
--- libcxx/cmake/caches/Apple.cmake
+++ libcxx/cmake/caches/Apple.cmake
@@ -4,7 +4,6 @@
set(LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
set(LIBCXX_ENABLE_ASSERTIONS OFF CACHE BOOL "")
set(LIBCXX_ABI_VERSION "1" CACHE STRING "")
-set(LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY OFF CACHE BOOL "")
set(LIBCXX_ENABLE_STATIC ON CACHE BOOL "")
set(LIBCXX_ENABLE_SHARED ON CACHE BOOL "")
set(LIBCXX_CXX_ABI libcxxabi CACHE STRING "")
Index: libcxx/cmake/caches/AIX.cmake
===================================================================
--- libcxx/cmake/caches/AIX.cmake
+++ libcxx/cmake/caches/AIX.cmake
@@ -9,7 +9,6 @@
set(LIBCXX_ENABLE_ASSERTIONS OFF CACHE BOOL "")
set(LIBCXX_ABI_VERSION "1" CACHE STRING "")
set(LIBCXX_ENABLE_ABI_LINKER_SCRIPT OFF CACHE BOOL "")
-set(LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY OFF CACHE BOOL "")
set(LIBCXX_ENABLE_SHARED ON CACHE BOOL "")
set(LIBCXX_ENABLE_STATIC OFF CACHE BOOL "")
set(LIBCXXABI_ENABLE_SHARED ON CACHE BOOL "")
Index: libcxx/appveyor.yml
===================================================================
--- libcxx/appveyor.yml
+++ libcxx/appveyor.yml
@@ -45,7 +45,7 @@
#############################################################################
- cmake -G "%GENERATOR%" %CMAKE_OPTIONS%
"-DCMAKE_BUILD_TYPE=%configuration%"
- "-DLLVM_PATH=C:\projects\deps\llvm" -DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY=OFF
+ "-DLLVM_PATH=C:\projects\deps\llvm"
-DLLVM_LIT_ARGS="-sv --show-xfail --show-unsupported"
%APPVEYOR_BUILD_FOLDER%
Index: libcxx/CMakeLists.txt
===================================================================
--- libcxx/CMakeLists.txt
+++ libcxx/CMakeLists.txt
@@ -55,7 +55,6 @@
by users in their own code regardless of this option." OFF)
option(LIBCXX_ENABLE_SHARED "Build libc++ as a shared library." ON)
option(LIBCXX_ENABLE_STATIC "Build libc++ as a static library." ON)
-option(LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY "Build libc++experimental.a" ON)
set(ENABLE_FILESYSTEM_DEFAULT ON)
if (WIN32 AND NOT MINGW)
# Filesystem is buildable for windows, but it requires __int128 helper
@@ -167,9 +166,6 @@
cmake_dependent_option(LIBCXX_INSTALL_SHARED_LIBRARY
"Install the shared libc++ library." ON
"LIBCXX_ENABLE_SHARED;LIBCXX_INSTALL_LIBRARY" OFF)
-cmake_dependent_option(LIBCXX_INSTALL_EXPERIMENTAL_LIBRARY
- "Install libc++experimental.a" ON
- "LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY;LIBCXX_INSTALL_LIBRARY" OFF)
option(LIBCXX_ABI_UNSTABLE "Use the unstable ABI of libc++. This is equivalent to specifying LIBCXX_ABI_VERSION=n, where n is the not-yet-stable version." OFF)
if (LIBCXX_ABI_UNSTABLE)
@@ -932,11 +928,7 @@
add_subdirectory(src)
add_subdirectory(utils)
-set(LIBCXX_TEST_DEPS "")
-
-if (LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY)
- list(APPEND LIBCXX_TEST_DEPS cxx_experimental)
-endif()
+set(LIBCXX_TEST_DEPS "cxx_experimental")
if (LIBCXX_BUILD_EXTERNAL_THREAD_LIBRARY)
list(APPEND LIBCXX_TEST_DEPS cxx_external_threads)
Index: compiler-rt/cmake/Modules/AddCompilerRT.cmake
===================================================================
--- compiler-rt/cmake/Modules/AddCompilerRT.cmake
+++ compiler-rt/cmake/Modules/AddCompilerRT.cmake
@@ -685,7 +685,6 @@
-DLIBCXXABI_HERMETIC_STATIC_LIBRARY=ON
-DLIBCXXABI_INCLUDE_TESTS=OFF
-DLIBCXX_CXX_ABI=libcxxabi
- -DLIBCXX_ENABLE_EXPERIMENTAL_LIBRARY=OFF
-DLIBCXX_ENABLE_SHARED=OFF
-DLIBCXX_HERMETIC_STATIC_LIBRARY=ON
-DLIBCXX_INCLUDE_BENCHMARKS=OFF
Index: clang/cmake/caches/Fuchsia.cmake
===================================================================
--- clang/cmake/caches/Fuchsia.cmake
+++ clang/cmake/caches/Fuchsia.cmake
@@ -50,7 +50,6 @@
if(WIN32)
set(LIBCXX_ABI_VERSION 2 CACHE STRING "")
- set(LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY OFF CACHE BOOL "")
set(LIBCXX_ENABLE_FILESYSTEM OFF CACHE BOOL "")
set(LIBCXX_ENABLE_ABI_LINKER_SCRIPT OFF CACHE BOOL "")
set(LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
Index: clang/cmake/caches/Fuchsia-stage2.cmake
===================================================================
--- clang/cmake/caches/Fuchsia-stage2.cmake
+++ clang/cmake/caches/Fuchsia-stage2.cmake
@@ -79,7 +79,6 @@
set(RUNTIMES_${target}_CMAKE_SYSTEM_NAME Windows CACHE STRING "")
set(RUNTIMES_${target}_CMAKE_BUILD_TYPE RelWithDebInfo CACHE STRING "")
set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
- set(RUNTIMES_${target}_LIBCXX_ENABLE_EXPERIMENTAL_LIBRARY OFF CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ENABLE_FILESYSTEM OFF CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ENABLE_ABI_LINKER_SCRIPT OFF CACHE BOOL "")
set(RUNTIMES_${target}_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
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