Switch to use CXX11 ABI

CMakeLists.txt

@@ -59,18 +59,12 @@ endif()
 string(APPEND CMAKE_CUDA_FLAGS " -DLIBCUDACXX_ENABLE_SIMPLIFIED_COMPLEX_OPERATIONS")
 
 if(LINUX)
-  include(cmake/CheckAbi.cmake)
   string(APPEND CMAKE_CXX_FLAGS " -D_GLIBCXX_USE_CXX11_ABI=${GLIBCXX_USE_CXX11_ABI}")
   string(APPEND CMAKE_CUDA_FLAGS " -D_GLIBCXX_USE_CXX11_ABI=${GLIBCXX_USE_CXX11_ABI}")
-  if(${GLIBCXX_USE_CXX11_ABI} EQUAL 1)
-    set(CXX_STANDARD_REQUIRED ON)
-  else()
-    # Please note this is required in order to ensure compatibility between gcc 9 and gcc 7
-    # This could be removed when all Linux PyTorch binary builds are compiled by the same toolchain again
-    append_cxx_flag_if_supported("-fabi-version=11" CMAKE_CXX_FLAGS)
-  endif()
+  set(GLIBCXX_USE_CXX11_ABI 1 CACHE BOOL "Use C++11 ABI")
 endif()
 
+set(CXX_STANDARD_REQUIRED ON)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 set(CMAKE_LINK_WHAT_YOU_USE TRUE)
 

README.md

@@ -246,11 +246,6 @@ git submodule update --init --recursive
 #### Install PyTorch
 **On Linux**
 
-If you would like to compile PyTorch with [new C++ ABI](https://gcc.gnu.org/onlinedocs/libstdc++/manual/using_dual_abi.html) enabled, then first run this command:
-```bash
-export _GLIBCXX_USE_CXX11_ABI=1
-```
-
 If you're compiling for AMD ROCm then first run this command:
 ```bash
 # Only run this if you're compiling for ROCm

caffe2/CMakeLists.txt

@@ -1276,10 +1276,6 @@ if(BUILD_TEST)
   endif()
 endif()
 
-if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-  include(../cmake/CheckAbi.cmake)
-endif()
-
 # CMake config for external projects.
 configure_file(
   ${PROJECT_SOURCE_DIR}/cmake/TorchConfigVersion.cmake.in

cmake/TorchConfig.cmake.in

@@ -159,11 +159,6 @@ if(@USE_CUDA@)
   list(APPEND TORCH_LIBRARIES ${TORCH_CUDA_LIBRARIES})
 endif()
 
-# When we build libtorch with the old libstdc++ ABI, dependent libraries must too.
-if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-  set(TORCH_CXX_FLAGS "-D_GLIBCXX_USE_CXX11_ABI=@GLIBCXX_USE_CXX11_ABI@")
-endif()
-
 find_library(TORCH_LIBRARY torch PATHS "${TORCH_INSTALL_PREFIX}/lib")
 # the statements below changes target properties on
 # - the imported target from Caffe2Targets.cmake in shared library mode (see the find_package above)

tools/setup_helpers/cmake.py

@@ -190,7 +190,6 @@ def generate(
             # Key: environment variable name. Value: Corresponding variable name to be passed to CMake. If you are
             # adding a new build option to this block: Consider making these two names identical and adding this option
             # in the block below.
-            "_GLIBCXX_USE_CXX11_ABI": "GLIBCXX_USE_CXX11_ABI",
             "CUDNN_LIB_DIR": "CUDNN_LIBRARY",
             "USE_CUDA_STATIC_LINK": "CAFFE2_STATIC_LINK_CUDA",
         }

torch/__init__.py

@@ -1633,7 +1633,7 @@ def _assert(condition, message):
 
 def compiled_with_cxx11_abi() -> builtins.bool:
     r"""Returns whether PyTorch was built with _GLIBCXX_USE_CXX11_ABI=1"""
-    return _C._GLIBCXX_USE_CXX11_ABI
+    return True
 
 
 # Import the ops "namespace"

torch/_inductor/codecache.py

@@ -1461,10 +1461,6 @@ def get_warning_all_flag(warning_all: bool = True) -> str:
     return "-Wall" if warning_all else ""
 
 
-def get_glibcxx_abi_build_flags() -> str:
-    return "-D_GLIBCXX_USE_CXX11_ABI=" + str(int(torch._C._GLIBCXX_USE_CXX11_ABI))
-
-
 def cpp_flags() -> str:
     flags = ["-std=c++17", "-Wno-unused-variable", "-Wno-unknown-pragmas"]
     if is_clang():
@@ -1812,7 +1808,6 @@ def cpp_compile_command(
         f"""
             {cpp_compiler()} {inp_name_str} {get_shared(shared, compile_only)}
             {get_warning_all_flag(warning_all)} {cpp_flags()}
-            {get_glibcxx_abi_build_flags()}
             {ipaths_str} {lpaths} {libs} {build_arch_flags}
             {macros} {linker_paths} {clang_flags}
             {optimization_flags()}

torch/csrc/Module.cpp

@@ -2087,12 +2087,7 @@ Call this whenever a new thread is created in order to propagate values from
   ASSERT_TRUE(
       set_module_attr("_has_mkldnn", at::hasMKLDNN() ? Py_True : Py_False));
 
-#ifdef _GLIBCXX_USE_CXX11_ABI
-  ASSERT_TRUE(set_module_attr(
-      "_GLIBCXX_USE_CXX11_ABI", _GLIBCXX_USE_CXX11_ABI ? Py_True : Py_False));
-#else
-  ASSERT_TRUE(set_module_attr("_GLIBCXX_USE_CXX11_ABI", Py_False));
-#endif
+  ASSERT_TRUE(set_module_attr("_GLIBCXX_USE_CXX11_ABI", Py_True));
 
 // See note [Pybind11 ABI constants]
 #define SET_STR_DEFINE(name) \

torch/utils/cpp_extension.py

@@ -536,7 +536,6 @@ def build_extensions(self) -> None:
                 if val is not None and not IS_WINDOWS:
                     self._add_compile_flag(extension, f'-DPYBIND11_{name}="{val}"')
             self._define_torch_extension_name(extension)
-            self._add_gnu_cpp_abi_flag(extension)
 
             if 'nvcc_dlink' in extension.extra_compile_args:
                 assert self.use_ninja, f"With dlink=True, ninja is required to build cuda extension {extension.name}."
@@ -914,8 +913,7 @@ def _define_torch_extension_name(self, extension):
         self._add_compile_flag(extension, define)
 
     def _add_gnu_cpp_abi_flag(self, extension):
-        # use the same CXX ABI as what PyTorch was compiled with
-        self._add_compile_flag(extension, '-D_GLIBCXX_USE_CXX11_ABI=' + str(int(torch._C._GLIBCXX_USE_CXX11_ABI)))
+        pass
 
 
 def CppExtension(name, sources, *args, **kwargs):
@@ -1334,9 +1332,6 @@ def _get_pybind11_abi_build_flags():
             abi_cflags.append(f'-DPYBIND11_{pname}=\\"{pval}\\"')
     return abi_cflags
 
-def _get_glibcxx_abi_build_flags():
-    glibcxx_abi_cflags = ['-D_GLIBCXX_USE_CXX11_ABI=' + str(int(torch._C._GLIBCXX_USE_CXX11_ABI))]
-    return glibcxx_abi_cflags
 
 def check_compiler_is_gcc(compiler):
     if not IS_LINUX:
@@ -1471,7 +1466,6 @@ def build_precompile_header(pch_cmd):
 
     common_cflags += ['-std=c++17', '-fPIC']
     common_cflags += [f"{x}" for x in _get_pybind11_abi_build_flags()]
-    common_cflags += [f"{x}" for x in _get_glibcxx_abi_build_flags()]
     common_cflags_str = listToString(common_cflags)
 
     pch_cmd = format_precompiler_header_cmd(compiler, head_file, head_file_pch, common_cflags_str, torch_include_dirs_str, extra_cflags_str, extra_include_paths_str)
@@ -2181,7 +2175,6 @@ def _write_ninja_file_to_build_library(path,
         common_cflags += [f'-I{shlex.quote(include)}' for include in user_includes]
         common_cflags += [f'-isystem {shlex.quote(include)}' for include in system_includes]
 
-    common_cflags += [f"{x}" for x in _get_glibcxx_abi_build_flags()]
 
     if IS_WINDOWS:
         cflags = common_cflags + COMMON_MSVC_FLAGS + ['/std:c++17'] + extra_cflags