toolchains/common/meson-crossgen

#!/usr/bin/env python3

# Copyright 2017 Jussi Pakkanen
# Copyright 2021 ScummVM team

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at

#     http://www.apache.org/licenses/LICENSE-2.0

# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import argparse
import os
import re
import shlex
import sys

parser = argparse.ArgumentParser(description='''Generate cross compilation definition file for the Meson build system.

This script must be run in an environment where CC, CXX, LD, CPPFLAGS, CFLAGS et al are set to the
same values used in the actual compilation.
'''
)

parser.add_argument('--system', required=True,
                    help='The system to use.')
parser.add_argument('--cpu', required=True,
                    help='The cpu to generate.')
parser.add_argument('--sysroot', default=None,
                    help='The sysroot location.')
parser.add_argument('-o', required=True, dest='outfile',
                    help='The output file.')

def locate_path(program):
    if os.path.isabs(program):
        return program
    for d in os.get_exec_path():
        f = os.path.join(d, program)
        if os.access(f, os.X_OK):
            return f
    raise ValueError("{0} not found on $PATH".format(program))

def get_value(v, context):
    if callable(v):
        return v(context)
    return v

def write_args_line(ofile, name, args):
    if len(args) == 0:
        return
    ostr = '{0} = [{1}]\n'.format(name,
            ', '.join("'{0}'".format(i) for i in args))
    ofile.write(ostr)

BINARIES = {
    'AR': ('ar', None),
    'C': ('c', None),
    'CXX': ('cpp', None),
    'OBJCOPY': ('objcopy', None),
    'LD': ('ld', None),
    'PKG_CONFIG': ('pkgconfig', 'pkg-config'),
    'STRIP': ('strip', None),
    'WINDRES': ('windres', None),
}

def write_binaries(ofile):
    for envvar, (confvar, default) in BINARIES.items():
        binary = os.environ.get(envvar, default)
        if binary:
            ofile.write("{0} = '{1}'\n".format(
                confvar,
                locate_path(binary)))

def write_args_from_envvars(ofile):
    cppflags = shlex.split(os.environ.get('CPPFLAGS', ''))
    cflags = shlex.split(os.environ.get('CFLAGS', ''))
    cxxflags = shlex.split(os.environ.get('CXXFLAGS', ''))
    ldflags = shlex.split(os.environ.get('LDFLAGS', ''))

    c_args = cppflags + cflags
    cpp_args = cppflags + cxxflags
    c_link_args = cflags + ldflags
    cpp_link_args = cxxflags + ldflags

    write_args_line(ofile, 'c_args', c_args)
    write_args_line(ofile, 'cpp_args', cpp_args)
    write_args_line(ofile, 'c_link_args', c_link_args)
    write_args_line(ofile, 'cpp_link_args', cpp_link_args)

def write_properties(ofile, sysroot):
    if not sysroot:
        sysroot = os.environ.get('PKG_CONFIG_SYSROOT_DIR', None)
    if sysroot:
        ofile.write("sys_root = '{0}'\n".format(sysroot))

    pkg_config_libdir = os.environ.get('PKG_CONFIG_LIBDIR', None)
    if pkg_config_libdir:
        ofile.write("pkg_config_libdir = '{0}'\n".format(pkg_config_libdir))

# Order in this list is important: most specific match first
CPUS = [
    {'key': r'(i[34567]86|pentium)',  'family': 'x86', 'bigendian': False },
    {'key': r'(x86_64|amd64)',        'family': 'x86_64', 'bigendian': False },
    {'key': r'alpha.*',               'family': 'alpha', 'bigendian': False },
    {'key': r'(arm64|aarch64).*',     'family': 'aarch64', 'bigendian': False, 'cpu': 'aarch64' },
    {'key': r'(arm.*)b',              'family': 'arm', 'bigendian': True, 'cpu': lambda m: m.group(1) },
    {'key': r'arm.*',                 'family': 'arm', 'bigendian': False },
    {'key': r'avr32',                 'family': 'avr', 'bigendian': True },
    {'key': r'ia64',                  'family': 'ia64', 'bigendian': False },
    {'key': r'm32r',                  'family': 'm32r', 'bigendian': True },
    {'key': r'm68k',                  'family': 'm68k', 'bigendian': True },
    {'key': r'mips(32)?(eb)?',        'family': 'mips', 'bigendian': True, 'cpu': 'mips' },
    {'key': r'mips(32)?el',           'family': 'mips', 'bigendian': False, 'cpu': 'mips' },
    {'key': r'mips64',                'family': 'mips64', 'bigendian': True },
    {'key': r'mips64el',              'family': 'mips64', 'bigendian': False, 'cpu': 'mips64' },
    {'key': r'hppa.*',                'family': 'parisc', 'bigendian': True },
    {'key': r'(powerpc|ppc)',         'family': 'ppc', 'bigendian': True },
    {'key': r'powerpcle',             'family': 'ppc', 'bigendian': False, 'cpu': 'powerpc' },
    {'key': r'(powerpc|ppc)64',       'family': 'ppc64', 'bigendian': True },
    {'key': r'powerpc64le',           'family': 'ppc64', 'bigendian': False, 'cpu': 'powerpc64' },
    {'key': r'riscv64',               'family': 'riscv64', 'bigendian': False },
    {'key': r's390',                  'family': 's390', 'bigendian': True },
    {'key': r's390x',                 'family': 's390x', 'bigendian': True },
    {'key': r'sh4',                   'family': 'sh4', 'bigendian': False },
    {'key': r'sh4eb',                 'family': 'sh4', 'bigendian': True, 'cpu': 'sh4' },
    {'key': r'sparc',                 'family': 'sparc', 'bigendian': True },
    {'key': r'sparc64',               'family': 'sparc64', 'bigendian': True },
]
for cpu in CPUS:
    cpu['key'] = re.compile(cpu['key'])

def find_cpu(cpu_name):
    for cpu in CPUS:
        mtch = cpu['key'].match(cpu_name)
        if mtch is None:
            continue

        family = get_value(cpu['family'], mtch)
        endian = 'big' if get_value(cpu['bigendian'], mtch) else 'little'
        cpu_name = get_value(cpu.get('cpu', cpu_name), mtch)

        return {
            'cpu_family': family,
            'endian': endian,
            'cpu': cpu_name,
        }

    raise LookupError("Can't find cpu {0}".format(cpu_name))

def run(options):
    cpu = find_cpu(options.cpu)
    os.makedirs(os.path.dirname(options.outfile), exist_ok=True)
    with open(options.outfile, "w") as ofile:
        ofile.write('[host_machine]\n')
        ofile.write("system = '{0}'\n".format(options.system))
        for k, v in cpu.items():
            ofile.write("{0} = '{1}'\n".format(k, v))
        ofile.write('\n[binaries]\n')
        write_binaries(ofile)
        ofile.write('\n[built-in options]\n')
        write_args_from_envvars(ofile)
        ofile.write('\n[properties]\n')
        write_properties(ofile, options.sysroot)

if __name__ == '__main__':
    options = parser.parse_args()
    run(options)