# Custom script is necessary because CMake does not yet support creating static libraries combined with dependencies # https://gitlab.kitware.com/cmake/cmake/-/issues/22975 # # This script is intended to be used set as a CXX_LINKER_LAUNCHER property for recursive library targets. # It parses the linking command and transforms it to archiving commands combining static libraries from dependencies. import argparse import os import re import shlex import subprocess import sys import tempfile class Opts(object): def __init__(self, args): argparser = argparse.ArgumentParser(allow_abbrev=False) argparser.add_argument('--project-binary-dir', required=True) argparser.add_argument('--cmake-ar', required=True) argparser.add_argument('--cmake-ranlib', required=True) argparser.add_argument('--cmake-host-system-name', required=True) argparser.add_argument('--cmake-cxx-standard-libraries') argparser.add_argument('--global-part-suffix', required=True) self.parsed_args, other_args = argparser.parse_known_args(args=args) if len(other_args) < 2: # must contain at least '--linking-cmdline' and orginal linking tool name raise Exception('not enough arguments') if other_args[0] != '--linking-cmdline': raise Exception("expected '--linking-cmdline' arg, got {}".format(other_args[0])) self.is_msvc_compatible_linker = other_args[1].endswith('\\link.exe') or other_args[1].endswith('\\lld-link.exe') is_host_system_windows = self.parsed_args.cmake_host_system_name == 'Windows' std_libraries_to_exclude_from_input = ( set(self.parsed_args.cmake_cxx_standard_libraries.split()) if self.parsed_args.cmake_cxx_standard_libraries is not None else set() ) msvc_preserved_option_prefixes = [ 'machine:', 'nodefaultlib', 'nologo', ] self.preserved_options = [] # these variables can contain paths absolute or relative to project_binary_dir self.global_libs_and_objects_input = [] self.non_global_libs_input = [] self.output = None def is_external_library(path): """ Check whether this library has been built in this CMake project or came from Conan-provided dependencies (these use absolute paths). If it is a library that is added from some other path (like CUDA) return True """ return not (os.path.exists(path) or os.path.exists(os.path.join(self.parsed_args.project_binary_dir, path))) def process_input(args): i = 0 is_in_whole_archive = False while i < len(args): arg = args[i] if is_host_system_windows and ((arg[0] == '/') or (arg[0] == '-')): arg_wo_specifier_lower = arg[1:].lower() if arg_wo_specifier_lower.startswith('out:'): self.output = arg[len('/out:') :] elif arg_wo_specifier_lower.startswith('wholearchive:'): lib_path = arg[len('/wholearchive:') :] if not is_external_library(lib_path): self.global_libs_and_objects_input.append(lib_path) else: for preserved_option_prefix in msvc_preserved_option_prefixes: if arg_wo_specifier_lower.startswith(preserved_option_prefix): self.preserved_options.append(arg) break # other flags are non-linking related and just ignored elif arg[0] == '-': if arg == '-o': if (i + 1) >= len(args): raise Exception('-o flag without an argument') self.output = args[i + 1] i += 1 elif arg == '-Wl,--whole-archive': is_in_whole_archive = True elif arg == '-Wl,--no-whole-archive': is_in_whole_archive = False elif arg.startswith('-Wl,-force_load,'): lib_path = arg[len('-Wl,-force_load,') :] if not is_external_library(lib_path): self.global_libs_and_objects_input.append(lib_path) elif arg == '-isysroot': i += 1 # other flags are non-linking related and just ignored elif arg[0] == '@': # response file with args with open(arg[1:]) as response_file: parsed_args = shlex.shlex(response_file, posix=False, punctuation_chars=False) parsed_args.whitespace_split = True args_in_response_file = list(arg.strip('"') for arg in parsed_args) process_input(args_in_response_file) elif not is_external_library(arg): if is_in_whole_archive or arg.endswith('.o') or arg.endswith('.obj'): self.global_libs_and_objects_input.append(arg) elif arg not in std_libraries_to_exclude_from_input: self.non_global_libs_input.append(arg) i += 1 process_input(other_args[2:]) if self.output is None: raise Exception("No output specified") if (len(self.global_libs_and_objects_input) == 0) and (len(self.non_global_libs_input) == 0): raise Exception("List of input objects and libraries is empty") class FilesCombiner(object): def __init__(self, opts): self.opts = opts archiver_tool_path = opts.parsed_args.cmake_ar if sys.platform.startswith('darwin'): # force LIBTOOL even if CMAKE_AR is defined because 'ar' under Darwin does not contain the necessary options arch_type = 'LIBTOOL' archiver_tool_path = 'libtool' elif opts.is_msvc_compatible_linker: arch_type = 'LIB' elif re.match(r'^(|.*/)llvm\-ar(\-[\d])?', opts.parsed_args.cmake_ar): arch_type = 'LLVM_AR' elif re.match(r'^(|.*/)(gcc\-)?ar(\-[\d])?', opts.parsed_args.cmake_ar): arch_type = 'GNU_AR' else: raise Exception('Unsupported arch type for CMAKE_AR={}'.format(opts.parsed_args.cmake_ar)) self.archiving_cmd_prefix = [ sys.executable, os.path.join(os.path.dirname(os.path.abspath(__file__)), 'link_lib.py'), archiver_tool_path, arch_type, 'gnu', # llvm_ar_format, used only if arch_type == 'LLVM_AR' opts.parsed_args.project_binary_dir, 'None', # plugin. Unused for now ] # the remaining archiving cmd args are [output, .. input .. ] def do(self, output, input_list): input_file_path = None try: if self.opts.is_msvc_compatible_linker: # use response file for input (because of Windows cmdline length limitations) # can't use NamedTemporaryFile because of permissions issues on Windows input_file_fd, input_file_path = tempfile.mkstemp() try: input_file = os.fdopen(input_file_fd, 'w') for input in input_list: if ' ' in input: input_file.write('"{}" '.format(input)) else: input_file.write('{} '.format(input)) input_file.flush() finally: os.close(input_file_fd) input_args = ['@' + input_file_path] else: input_args = input_list cmd = self.archiving_cmd_prefix + [output] + self.opts.preserved_options + input_args subprocess.check_call(cmd) finally: if input_file_path is not None: os.remove(input_file_path) if not self.opts.is_msvc_compatible_linker: subprocess.check_call([self.opts.parsed_args.cmake_ranlib, output]) if __name__ == "__main__": opts = Opts(sys.argv[1:]) output_prefix, output_ext = os.path.splitext(opts.output) globals_output = output_prefix + opts.parsed_args.global_part_suffix + output_ext if os.path.exists(globals_output): os.remove(globals_output) if os.path.exists(opts.output): os.remove(opts.output) files_combiner = FilesCombiner(opts) if len(opts.global_libs_and_objects_input) > 0: files_combiner.do(globals_output, opts.global_libs_and_objects_input) if len(opts.non_global_libs_input) > 0: files_combiner.do(opts.output, opts.non_global_libs_input)