cmake: Inline the add_llvm_symbol_exports.py script

[tstellar]

Summary

This fixes stand-alone builds.

[andrewng]

LGTM.

llvm/cmake/modules/AddLLVM.cmake

elseif(${CMAKE_SYSTEM_NAME} MATCHES "AIX")
     set_property(TARGET ${target_name} APPEND_STRING PROPERTY
                  LINK_FLAGS " -Wl,-bE:${export_file}")
   elseif(LLVM_HAVE_LINK_VERSION_SCRIPT)
     # Gold and BFD ld require a version script rather than a plain list.
     set(native_export_file "${target_name}.exports")
     # FIXME: Don't write the "local:" line on OpenBSD.
     # in the export file, also add a linker script to version LLVM symbols (form: LLVM_N.M)
     add_custom_command(OUTPUT ${native_export_file}
-      COMMAND "${Python3_EXECUTABLE}" ${LLVM_MAIN_SRC_DIR}/utils/add_llvm_symbol_exports.py ${LLVM_VERSION_MAJOR} ${export_file} ${native_export_file}
+      COMMAND "${Python3_EXECUTABLE}" "-c"
+      "import sys; \
+       lines = ['    ' + l.rstrip() for l in sys.stdin] + ['  local: *;']; \
+       print('LLVM_${LLVM_VERSION_MAJOR} {'); \
+       print('  global:') if len(lines) > 1 else None; \
+       print(';\\n'.join(lines) + '\\n};')"
+      < ${export_file} > ${native_export_file}
       DEPENDS ${export_file}
       VERBATIM
       COMMENT "Creating export file for ${target_name}")
     if (${LLVM_LINKER_IS_SOLARISLD})
       set_property(TARGET ${target_name} APPEND_STRING PROPERTY
                    LINK_FLAGS "  -Wl,-M,\"${CMAKE_CURRENT_BINARY_DIR}/${native_export_file}\"")
     else()
       set_property(TARGET ${target_name} APPEND_STRING PROPERTY

llvm/utils/add_llvm_symbol_exports.py

-#!/usr/bin/env python3
-#===----------------------------------------------------------------------===##
-#
-# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-# See https://llvm.org/LICENSE.txt for license information.
-# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-#
-#===----------------------------------------------------------------------===##
-
-import os
-import sys
-
-if (len(sys.argv) != 4):
-    print('usage: ' + sys.argv[0] + ' <LLVM major version> <input> <output>')
-    sys.exit(1)
-
-with open(sys.argv[3], 'w') as out_fd:
-    out_fd.write('LLVM_' + sys.argv[1] + ' {\n')
-    if os.stat(sys.argv[2]).st_size > 0:
-        out_fd.write('  global:\n')
-        with open(sys.argv[2], 'r') as in_fd:
-            for e in in_fd.readlines():
-                out_fd.write('    ' + e.rstrip() + ';\n')
-    out_fd.write('  local: *;\n};\n')
-
-sys.exit(0)