[Build] Remove pre-CXX11 ABI logic from build script (pytorch#149888)

malfet · pytorchmergebot · commit 5a7588f1832a · 2025-03-25T03:17:16.000Z
Only keep one in check_binary_symbols to make sure there are no pre-CXX11 ABI symbols in the library Pull Request resolved: pytorch#149888 Approved by: https://github.com/atalman, https://github.com/seemethere ghstack dependencies: pytorch#149887
diff --git a/.ci/pytorch/check_binary.sh b/.ci/pytorch/check_binary.sh
@@ -78,47 +78,7 @@ fi
 
 echo "Checking that the gcc ABI is what we expect"
 if [[ "$(uname)" != 'Darwin' ]]; then
-  function is_expected() {
-    if [[ "$1" -gt 0 || "$1" == "ON " ]]; then
-      echo 1
-    fi
-  }
-
-  # First we check that the env var in TorchConfig.cmake is correct
-
-  # We search for D_GLIBCXX_USE_CXX11_ABI=1 in torch/TorchConfig.cmake
-  torch_config="${install_root}/share/cmake/Torch/TorchConfig.cmake"
-  if [[ ! -f "$torch_config" ]]; then
-    echo "No TorchConfig.cmake found!"
-    ls -lah "$install_root/share/cmake/Torch"
-    exit 1
-  fi
-  echo "Checking the TorchConfig.cmake"
-  cat "$torch_config"
-
-  # The sed call below is
-  #   don't print lines by default (only print the line we want)
-  # -n
-  #   execute the following expression
-  # e
-  #   replace lines that match with the first capture group and print
-  # s/.*D_GLIBCXX_USE_CXX11_ABI=\(.\)".*/\1/p
-  #   any characters, D_GLIBCXX_USE_CXX11_ABI=, exactly one any character, a
-  #   quote, any characters
-  #   Note the exactly one single character after the '='. In the case that the
-  #     variable is not set the '=' will be followed by a '"' immediately and the
-  #     line will fail the match and nothing will be printed; this is what we
-  #     want.  Otherwise it will capture the 0 or 1 after the '='.
-  # /.*D_GLIBCXX_USE_CXX11_ABI=\(.\)".*/
-  #   replace the matched line with the capture group and print
-  # /\1/p
-  actual_gcc_abi="$(sed -ne 's/.*D_GLIBCXX_USE_CXX11_ABI=\(.\)".*/\1/p' < "$torch_config")"
-  if [[ "$(is_expected "$actual_gcc_abi")" != 1 ]]; then
-    echo "gcc ABI $actual_gcc_abi not as expected."
-    exit 1
-  fi
-
-  # We also check that there are [not] cxx11 symbols in libtorch
+  # We also check that there are cxx11 symbols in libtorch
   #
   echo "Checking that symbols in libtorch.so have the right gcc abi"
   python3 "$(dirname ${BASH_SOURCE[0]})/smoke_test/check_binary_symbols.py"
diff --git a/.ci/pytorch/smoke_test/check_binary_symbols.py b/.ci/pytorch/smoke_test/check_binary_symbols.py
@@ -80,36 +80,20 @@ def _get_symbols_chunk(i):
         return functools.reduce(list.__add__, (x.result() for x in tasks), [])
 
 
-def check_lib_symbols_for_abi_correctness(lib: str, pre_cxx11_abi: bool = True) -> None:
+def check_lib_symbols_for_abi_correctness(lib: str) -> None:
     print(f"lib: {lib}")
     cxx11_symbols = grep_symbols(lib, LIBTORCH_CXX11_PATTERNS)
     pre_cxx11_symbols = grep_symbols(lib, LIBTORCH_PRE_CXX11_PATTERNS)
     num_cxx11_symbols = len(cxx11_symbols)
     num_pre_cxx11_symbols = len(pre_cxx11_symbols)
     print(f"num_cxx11_symbols: {num_cxx11_symbols}")
     print(f"num_pre_cxx11_symbols: {num_pre_cxx11_symbols}")
-    if pre_cxx11_abi:
-        if num_cxx11_symbols > 0:
-            raise RuntimeError(
-                f"Found cxx11 symbols, but there shouldn't be any, see: {cxx11_symbols[:100]}"
-            )
-        if num_pre_cxx11_symbols < 1000:
-            raise RuntimeError("Didn't find enough pre-cxx11 symbols.")
-        # Check for no recursive iterators, regression test for https://github.com/pytorch/pytorch/issues/133437
-        rec_iter_symbols = grep_symbols(
-            lib, [re.compile("std::filesystem::recursive_directory_iterator.*")]
+    if num_pre_cxx11_symbols > 0:
+        raise RuntimeError(
+            f"Found pre-cxx11 symbols, but there shouldn't be any, see: {pre_cxx11_symbols[:100]}"
         )
-        if len(rec_iter_symbols) > 0:
-            raise RuntimeError(
-                f"recursive_directory_iterator in used pre-CXX11 binaries, see; {rec_iter_symbols}"
-            )
-    else:
-        if num_pre_cxx11_symbols > 0:
-            raise RuntimeError(
-                f"Found pre-cxx11 symbols, but there shouldn't be any, see: {pre_cxx11_symbols[:100]}"
-            )
-        if num_cxx11_symbols < 100:
-            raise RuntimeError("Didn't find enought cxx11 symbols")
+    if num_cxx11_symbols < 100:
+        raise RuntimeError("Didn't find enought cxx11 symbols")
 
 
 def main() -> None:
@@ -122,8 +106,7 @@ def main() -> None:
             install_root = Path(distutils.sysconfig.get_python_lib()) / "torch"
 
     libtorch_cpu_path = str(install_root / "lib" / "libtorch_cpu.so")
-    # NOTE: All binaries are built with cxx11abi now
-    check_lib_symbols_for_abi_correctness(libtorch_cpu_path, False)
+    check_lib_symbols_for_abi_correctness(libtorch_cpu_path)
 
 
 if __name__ == "__main__":
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -69,19 +69,7 @@ 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(CXX_STANDARD_REQUIRED ON)
 endif()
 
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
diff --git a/README.md b/README.md
@@ -274,13 +274,6 @@ conda install -c conda-forge libuv=1.39
 #### 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
-```
-
-Please **note** that starting from PyTorch 2.5, the PyTorch build with XPU supports both new and old C++ ABIs. Previously, XPU only supported the new C++ ABI. If you want to compile with Intel GPU support, please follow [Intel GPU Support](#intel-gpu-support).
-
 If you're compiling for AMD ROCm then first run this command:
 ```bash
 # Only run this if you're compiling for ROCm
diff --git a/caffe2/CMakeLists.txt b/caffe2/CMakeLists.txt
@@ -1317,10 +1317,6 @@ 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
diff --git a/cmake/CheckAbi.cmake b/cmake/CheckAbi.cmake
diff --git a/cmake/TorchConfig.cmake.in b/cmake/TorchConfig.cmake.in
@@ -147,11 +147,6 @@ if(@USE_XPU@ AND @BUILD_SHARED_LIBS@)
     append_torchlib_if_found(c10_xpu torch_xpu)
 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)
diff --git a/tools/setup_helpers/cmake.py b/tools/setup_helpers/cmake.py
@@ -189,7 +189,6 @@ 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",
         }
diff --git a/torch/__init__.py b/torch/__init__.py
@@ -2232,7 +2232,7 @@ 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
 
 
 from torch import _library as _library, _ops as _ops
diff --git a/torch/abi-check.cpp b/torch/abi-check.cpp
diff --git a/torch/csrc/Module.cpp b/torch/csrc/Module.cpp
@@ -2399,12 +2399,7 @@ 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) \
diff --git a/torch/utils/cpp_extension.py b/torch/utils/cpp_extension.py
@@ -655,7 +655,6 @@ 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}."
@@ -1113,10 +1112,6 @@ def _define_torch_extension_name(self, extension):
         define = f'-DTORCH_EXTENSION_NAME={name}'
         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)))
-
 
 def CppExtension(name, sources, *args, **kwargs):
     """
@@ -1688,10 +1683,6 @@ 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:
         return False
@@ -1822,7 +1813,6 @@ 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)
@@ -2644,8 +2634,6 @@ 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 + ['/std:c++17'] + extra_cflags
         cflags += COMMON_HIP_FLAGS if IS_HIP_EXTENSION else COMMON_MSVC_FLAGS

Original file line number	Diff line number	Diff line change
`@@ -189,7 +189,6 @@ def generate(`
`189`	`189`	`# Key: environment variable name. Value: Corresponding variable name to be passed to CMake. If you are`
`190`	`190`	`# adding a new build option to this block: Consider making these two names identical and adding this option`
`191`	`191`	`# in the block below.`
`192`		`- "_GLIBCXX_USE_CXX11_ABI": "GLIBCXX_USE_CXX11_ABI",`
`193`	`192`	`"CUDNN_LIB_DIR": "CUDNN_LIBRARY",`
`194`	`193`	`"USE_CUDA_STATIC_LINK": "CAFFE2_STATIC_LINK_CUDA",`
`195`	`194`	`}`