#!/usr/bin/env python3
# Copyright 2015 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Runs a linking command and optionally a strip command.

This script exists to avoid using complex shell commands in
gcc_toolchain.gni's tool("link"), in case the host running the compiler
does not have a POSIX-like shell (e.g. Windows).
"""

import argparse
import os
import subprocess
import sys

import wrapper_utils


# When running on a Windows host and using a toolchain whose tools are
# actually wrapper scripts (i.e. .bat files on Windows) rather than binary
# executables, the "command" to run has to be prefixed with this magic.
# The GN toolchain definitions take care of that for when GN/Ninja is
# running the tool directly.  When that command is passed in to this
# script, it appears as a unitary string but needs to be split up so that
# just 'cmd' is the actual command given to Python's subprocess module.
BAT_PREFIX = 'cmd /c call '


def CommandToRun(command):
    if command[0].startswith(BAT_PREFIX):
        command = command[0].split(None, 3) + command[1:]
    return command


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument(
        '--strip', help='The strip binary to run', metavar='PATH'
    )
    parser.add_argument(
        '--symbols-file',
        help='.so file with .debug sections (if different from --output)',
        metavar='FILE',
    )
    parser.add_argument(
        '--map-file',
        help=(
            'Use --Wl,-Map to generate a map file. Will be '
            'gzipped if extension ends with .gz'
        ),
        metavar='FILE',
    )
    parser.add_argument(
        '--output',
        required=True,
        help='Final output executable file',
        metavar='FILE',
    )
    parser.add_argument('command', nargs='+', help='Linking command')
    args = parser.parse_args()

    # Work-around for gold being slow-by-default. http://crbug.com/632230
    fast_env = dict(os.environ)
    fast_env['LC_ALL'] = 'C'
    result = wrapper_utils.RunLinkWithOptionalMapFile(
        args.command, env=fast_env, map_file=args.map_file
    )
    if result != 0:
        return result

    # Finally, strip the linked executable (if desired).
    if args.strip:
        result = subprocess.call(
            CommandToRun([args.strip, '-o', args.output, args.symbols_file])
        )

    return result


if __name__ == "__main__":
    sys.exit(main())