path: root/build/scripts/go_tool.py

from __future__ import absolute_import, unicode_literals
import argparse
import copy
import json
import os
import re
import shutil
import subprocess
import sys
import tarfile
import tempfile
import threading
import six
from functools import reduce

import process_command_files as pcf
import process_whole_archive_option as pwa

arc_project_prefix = 'a.yandex-team.ru/'
std_lib_prefix = 'contrib/go/_std/src/'
vendor_prefix = 'vendor/'
vet_info_ext = '.vet.out'
vet_report_ext = '.vet.txt'

FIXED_CGO1_SUFFIX='.fixed.cgo1.go'

COMPILE_OPTIMIZATION_FLAGS=('-N',)


def get_trimpath_args(args):
    return ['-trimpath', args.trimpath] if args.trimpath else []


def preprocess_cgo1(src_path, dst_path, source_root):
    with open(src_path, 'r') as f:
        content = f.read()
        content = content.replace('__ARCADIA_SOURCE_ROOT_PREFIX__', source_root)
    with open(dst_path, 'w') as f:
        f.write(content)


def preprocess_args(args):
    # Temporary work around for noauto
    if args.cgo_srcs and len(args.cgo_srcs) > 0:
        cgo_srcs_set = set(args.cgo_srcs)
        args.srcs = [x for x in args.srcs if x not in cgo_srcs_set]

    args.pkg_root = os.path.join(args.toolchain_root, 'pkg')
    toolchain_tool_root = os.path.join(args.pkg_root, 'tool', '{}_{}'.format(args.host_os, args.host_arch))
    args.go_compile = os.path.join(toolchain_tool_root, 'compile')
    args.go_cgo = os.path.join(toolchain_tool_root, 'cgo')
    args.go_link = os.path.join(toolchain_tool_root, 'link')
    args.go_asm = os.path.join(toolchain_tool_root, 'asm')
    args.go_pack = os.path.join(toolchain_tool_root, 'pack')
    args.go_vet = os.path.join(toolchain_tool_root, 'vet') if args.vet is True else args.vet
    args.output = os.path.normpath(args.output)
    args.vet_report_output = vet_report_output_name(args.output, args.vet_report_ext)
    args.trimpath = None
    if args.debug_root_map:
        roots = {'build': args.build_root, 'source': args.source_root, 'tools': args.tools_root}
        replaces = []
        for root in args.debug_root_map.split(';'):
            src, dst = root.split('=', 1)
            assert src in roots
            replaces.append('{}=>{}'.format(roots[src], dst))
            del roots[src]
        assert len(replaces) > 0
        args.trimpath = ';'.join(replaces)
    args.build_root = os.path.normpath(args.build_root)
    args.build_root_dir = args.build_root + os.path.sep
    args.source_root = os.path.normpath(args.source_root)
    args.source_root_dir = args.source_root + os.path.sep
    args.output_root = os.path.normpath(args.output_root)
    args.import_map = {}
    args.module_map = {}
    if args.cgo_peers:
        args.cgo_peers = [x for x in args.cgo_peers if not x.endswith('.fake.pkg')]

    srcs = []
    for f in args.srcs:
        if f.endswith('.gosrc'):
            with tarfile.open(f, 'r') as tar:
                srcs.extend(os.path.join(args.output_root, src) for src in tar.getnames())
                tar.extractall(path=args.output_root)
        else:
            srcs.append(f)
    args.srcs = srcs

    assert args.mode == 'test' or args.test_srcs is None and args.xtest_srcs is None
    # add lexical oreder by basename for go sources
    args.srcs.sort(key=lambda x: os.path.basename(x))
    if args.test_srcs:
        args.srcs += sorted(args.test_srcs, key=lambda x: os.path.basename(x))
        del args.test_srcs
    if args.xtest_srcs:
        args.xtest_srcs.sort(key=lambda x: os.path.basename(x))

    # compute root relative module dir path
    assert args.output is None or args.output_root == os.path.dirname(args.output)
    assert args.output_root.startswith(args.build_root_dir)
    args.module_path = args.output_root[len(args.build_root_dir):]
    args.source_module_dir = os.path.join(args.source_root, args.test_import_path or args.module_path) + os.path.sep
    assert len(args.module_path) > 0
    args.import_path, args.is_std = get_import_path(args.module_path)

    assert args.asmhdr is None or args.word == 'go'

    srcs = []
    for f in args.srcs:
        if f.endswith(FIXED_CGO1_SUFFIX) and f.startswith(args.build_root_dir):
            path = os.path.join(args.output_root, '{}.cgo1.go'.format(os.path.basename(f[:-len(FIXED_CGO1_SUFFIX)])))
            srcs.append(path)
            preprocess_cgo1(f, path, args.source_root)
        else:
            srcs.append(f)
    args.srcs = srcs

    if args.extldflags:
        args.extldflags = pwa.ProcessWholeArchiveOption(args.targ_os).construct_cmd(args.extldflags)

    classify_srcs(args.srcs, args)


def compare_versions(version1, version2):
    def last_index(version):
        index = version.find('beta')
        return len(version) if index < 0 else index

    v1 = tuple(x.zfill(8) for x in version1[:last_index(version1)].split('.'))
    v2 = tuple(x.zfill(8) for x in version2[:last_index(version2)].split('.'))
    if v1 == v2:
        return 0
    return 1 if v1 < v2 else -1


def get_symlink_or_copyfile():
    os_symlink = getattr(os, 'symlink', None)
    if os_symlink is None:
        os_symlink = shutil.copyfile
    return os_symlink


def copy_args(args):
    return copy.copy(args)


def get_vendor_index(import_path):
    index = import_path.rfind('/' + vendor_prefix)
    if index < 0:
        index = 0 if import_path.startswith(vendor_prefix) else index
    else:
        index = index + 1
    return index


def get_import_path(module_path):
    assert len(module_path) > 0
    import_path = module_path.replace('\\', '/')
    is_std_module = import_path.startswith(std_lib_prefix)
    if is_std_module:
        import_path = import_path[len(std_lib_prefix):]
    elif import_path.startswith(vendor_prefix):
        import_path = import_path[len(vendor_prefix):]
    else:
        import_path = arc_project_prefix + import_path
    assert len(import_path) > 0
    return import_path, is_std_module


def call(cmd, cwd, env=None):
    # sys.stderr.write('{}\n'.format(' '.join(cmd)))
    return subprocess.check_output(cmd, stdin=None, stderr=subprocess.STDOUT, cwd=cwd, env=env)


def classify_srcs(srcs, args):
    args.go_srcs = [x for x in srcs if x.endswith('.go')]
    args.asm_srcs = [x for x in srcs if x.endswith('.s')]
    args.objects = [x for x in srcs if x.endswith('.o') or x.endswith('.obj')]
    args.symabis = [x for x in srcs if x.endswith('.symabis')]
    args.sysos = [x for x in srcs if x.endswith('.syso')]


def get_import_config_info(peers, gen_importmap, import_map={}, module_map={}):
    info = {'importmap': [], 'packagefile': [], 'standard': {}}
    if gen_importmap:
        for key, value in six.iteritems(import_map):
            info['importmap'].append((key, value))
    for peer in peers:
        peer_import_path, is_std = get_import_path(os.path.dirname(peer))
        if gen_importmap:
            index = get_vendor_index(peer_import_path)
            if index >= 0:
                index += len(vendor_prefix)
                info['importmap'].append((peer_import_path[index:], peer_import_path))
        info['packagefile'].append((peer_import_path, os.path.join(args.build_root, peer)))
        if is_std:
            info['standard'][peer_import_path] = True
    for key, value in six.iteritems(module_map):
        info['packagefile'].append((key, value))
    return info


def create_import_config(peers, gen_importmap, import_map={}, module_map={}):
    lines = []
    info = get_import_config_info(peers, gen_importmap, import_map, module_map)
    for key in ('importmap', 'packagefile'):
        for item in info[key]:
            lines.append('{} {}={}'.format(key, *item))
    if len(lines) > 0:
        lines.append('')
        content = '\n'.join(lines)
        # sys.stderr.writelines('{}\n'.format(l) for l in lines)
        with tempfile.NamedTemporaryFile(delete=False) as f:
            f.write(content.encode('UTF-8'))
            return f.name
    return None


def create_embed_config(args):
    data = {
        'Patterns': {},
        'Files': {},
    }
    for info in args.embed:
        pattern = info[0]
        if pattern.endswith('/**/*'):
            pattern = pattern[:-3]
        files = {os.path.relpath(f, args.source_module_dir).replace('\\', '/'): f for f in info[1:]}
        data['Patterns'][pattern] = list(files.keys())
        data['Files'].update(files)
    # sys.stderr.write('{}\n'.format(json.dumps(data, indent=4)))
    with tempfile.NamedTemporaryFile(delete=False, suffix='.embedcfg') as f:
        f.write(json.dumps(data).encode('UTF-8'))
        return f.name


def vet_info_output_name(path, ext=None):
    return '{}{}'.format(path, ext or vet_info_ext)


def vet_report_output_name(path, ext=None):
    return '{}{}'.format(path, ext or vet_report_ext)


def get_source_path(args):
    return args.test_import_path or args.module_path


def gen_vet_info(args):
    import_path = args.real_import_path if hasattr(args, 'real_import_path') else args.import_path
    info = get_import_config_info(args.peers, True, args.import_map, args.module_map)

    import_map = dict(info['importmap'])
    # FIXME(snermolaev): it seems that adding import map for 'fake' package
    #                    does't make any harm (it needs to be revised later)
    import_map['unsafe'] = 'unsafe'

    for (key, _) in info['packagefile']:
        if key not in import_map:
            import_map[key] = key

    data = {
        'ID': import_path,
        'Compiler': 'gc',
        'Dir': os.path.join(args.source_root, get_source_path(args)),
        'ImportPath': import_path,
        'GoFiles': [x for x in args.go_srcs if x.endswith('.go')],
        'NonGoFiles': [x for x in args.go_srcs if not x.endswith('.go')],
        'ImportMap': import_map,
        'PackageFile': dict(info['packagefile']),
        'Standard': dict(info['standard']),
        'PackageVetx': dict((key, vet_info_output_name(value)) for key, value in info['packagefile']),
        'VetxOnly': False,
        'VetxOutput': vet_info_output_name(args.output),
        'SucceedOnTypecheckFailure': False
    }
    # sys.stderr.write('{}\n'.format(json.dumps(data, indent=4)))
    return data


def create_vet_config(args, info):
    with tempfile.NamedTemporaryFile(delete=False, suffix='.cfg') as f:
        f.write(json.dumps(info).encode('UTF-8'))
        return f.name


def decode_vet_report(json_report):
    report = ''
    if json_report:
        try:
            full_diags = json.JSONDecoder().decode(json_report.decode('UTF-8'))
        except ValueError:
            report = json_report
        else:
            messages = []
            for _, module_diags in six.iteritems(full_diags):
                for _, type_diags in six.iteritems(module_diags):
                    for diag in type_diags:
                        messages.append('{}: {}'.format(diag['posn'], json.dumps(diag['message'])))
            report = '\n'.join(messages)

    return report


def dump_vet_report(args, report):
    if report:
        report = report.replace(args.build_root, '$B')
        report = report.replace(args.source_root, '$S')
    with open(args.vet_report_output, 'w') as f:
        f.write(report)


def read_vet_report(args):
    assert args
    report = ''
    if os.path.exists(args.vet_report_output):
        with open(args.vet_report_output, 'r') as f:
            report += f.read()
    return report


def dump_vet_report_for_tests(args, *test_args_list):
    dump_vet_report(args, reduce(lambda x, y: x + read_vet_report(y), [_f for _f in test_args_list if _f], ''))


def do_vet(args):
    assert args.vet
    info = gen_vet_info(args)
    vet_config = create_vet_config(args, info)
    cmd = [args.go_vet, '-json']
    if args.vet_flags:
        cmd.extend(args.vet_flags)
    cmd.append(vet_config)
    # sys.stderr.write('>>>> [{}]\n'.format(' '.join(cmd)))
    p_vet = subprocess.Popen(cmd, stdin=None, stderr=subprocess.PIPE, stdout=subprocess.PIPE, cwd=args.source_root)
    vet_out, vet_err = p_vet.communicate()
    report = decode_vet_report(vet_out) if vet_out else ''
    dump_vet_report(args, report)
    if p_vet.returncode:
        raise subprocess.CalledProcessError(returncode=p_vet.returncode, cmd=cmd, output=vet_err)


def _do_compile_go(args):
    import_path, is_std_module = args.import_path, args.is_std
    cmd = [
        args.go_compile,
        '-o',
        args.output,
        '-p',
        import_path,
        '-D',
        '""',
        '-goversion',
        'go{}'.format(args.goversion)
    ]
    cmd.extend(get_trimpath_args(args))
    compiling_runtime = False
    if is_std_module:
        cmd.append('-std')
        if import_path in ('runtime', 'internal/abi', 'internal/bytealg', 'internal/cpu') or import_path.startswith('runtime/internal/'):
            cmd.append('-+')
            compiling_runtime = True
    import_config_name = create_import_config(args.peers, True, args.import_map, args.module_map)
    if import_config_name:
        cmd += ['-importcfg', import_config_name]
    else:
        if import_path == 'unsafe' or len(args.objects) > 0 or args.asmhdr:
            pass
        else:
            cmd.append('-complete')
    # if compare_versions('1.16', args.goversion) >= 0:
    if args.embed:
        embed_config_name = create_embed_config(args)
        cmd.extend(['-embedcfg', embed_config_name])
    if args.asmhdr:
        cmd += ['-asmhdr', args.asmhdr]
    # Use .symabis (starting from 1.12 version)
    if args.symabis:
        cmd += ['-symabis'] + args.symabis
    # If 1.12 <= version < 1.13 we have to pass -allabis for 'runtime' and 'runtime/internal/atomic'
    # if compare_versions('1.13', args.goversion) >= 0:
    #     pass
    # elif import_path in ('runtime', 'runtime/internal/atomic'):
    #     cmd.append('-allabis')
    compile_workers = '4'
    if args.compile_flags:
        if compiling_runtime:
            cmd.extend(x for x in args.compile_flags if x not in COMPILE_OPTIMIZATION_FLAGS)
        else:
            cmd.extend(args.compile_flags)
        if any([x in ('-race', '-shared') for x in args.compile_flags]):
            compile_workers = '1'
    cmd += ['-pack', '-c={}'.format(compile_workers)]
    cmd += args.go_srcs
    call(cmd, args.build_root)


class VetThread(threading.Thread):

    def __init__(self, target, args):
        super(VetThread, self).__init__(target=target, args=args)
        self.exc_info = None

    def run(self):
        try:
            super(VetThread, self).run()
        except:
            self.exc_info = sys.exc_info()

    def join_with_exception(self, reraise_exception):
        self.join()
        if reraise_exception and self.exc_info:
            six.reraise(self.exc_info[0], self.exc_info[1], self.exc_info[2])


def do_compile_go(args):
    raise_exception_from_vet = False
    if args.vet:
        run_vet = VetThread(target=do_vet, args=(args,))
        run_vet.start()
    try:
        _do_compile_go(args)
        raise_exception_from_vet = True
    finally:
        if args.vet:
            run_vet.join_with_exception(raise_exception_from_vet)


def do_compile_asm(args):
    def need_compiling_runtime(import_path):
        return import_path in ('runtime', 'reflect', 'syscall') or \
            import_path.startswith('runtime/internal/') or \
            compare_versions('1.17', args.goversion) >= 0 and import_path == 'internal/bytealg'

    assert(len(args.srcs) == 1 and len(args.asm_srcs) == 1)
    cmd = [args.go_asm]
    cmd += get_trimpath_args(args)
    cmd += ['-I', args.output_root, '-I', os.path.join(args.pkg_root, 'include')]
    cmd += ['-D', 'GOOS_' + args.targ_os, '-D', 'GOARCH_' + args.targ_arch, '-o', args.output]

    # if compare_versions('1.16', args.goversion) >= 0:
    cmd += ['-p', args.import_path]
    if need_compiling_runtime(args.import_path):
        cmd += ['-compiling-runtime']

    if args.asm_flags:
        cmd += args.asm_flags
    cmd += args.asm_srcs
    call(cmd, args.build_root)


def do_link_lib(args):
    if len(args.asm_srcs) > 0:
        asmargs = copy_args(args)
        asmargs.asmhdr = os.path.join(asmargs.output_root, 'go_asm.h')
        do_compile_go(asmargs)
        for src in asmargs.asm_srcs:
            asmargs.srcs = [src]
            asmargs.asm_srcs = [src]
            asmargs.output = os.path.join(asmargs.output_root, os.path.basename(src) + '.o')
            do_compile_asm(asmargs)
            args.objects.append(asmargs.output)
    else:
        do_compile_go(args)
    if args.objects or args.sysos:
        cmd = [args.go_pack, 'r', args.output] + args.objects + args.sysos
        call(cmd, args.build_root)


def do_link_exe(args):
    assert args.extld is not None
    assert args.non_local_peers is not None
    compile_args = copy_args(args)
    compile_args.output = os.path.join(args.output_root, 'main.a')
    compile_args.real_import_path = compile_args.import_path
    compile_args.import_path = 'main'

    if args.vcs and os.path.isfile(compile_args.vcs):
        build_info = os.path.join('library', 'go', 'core', 'buildinfo')
        if any([x.startswith(build_info) for x in compile_args.peers]):
            compile_args.go_srcs.append(compile_args.vcs)

    do_link_lib(compile_args)
    cmd = [args.go_link, '-o', args.output]
    import_config_name = create_import_config(args.peers + args.non_local_peers, False, args.import_map, args.module_map)
    if import_config_name:
        cmd += ['-importcfg', import_config_name]
    if args.link_flags:
        cmd += args.link_flags

    if args.mode in ('exe', 'test'):
        cmd.append('-buildmode=exe')
    elif args.mode == 'dll':
        cmd.append('-buildmode=c-shared')
    else:
        assert False, 'Unexpected mode: {}'.format(args.mode)
    cmd.append('-extld={}'.format(args.extld))

    extldflags = []
    if args.extldflags is not None:
        filter_musl = bool
        if args.musl:
            cmd.append('-linkmode=external')
            extldflags.append('-static')
            filter_musl = lambda x: x not in ('-lc', '-ldl', '-lm', '-lpthread', '-lrt')
        extldflags += [x for x in args.extldflags if filter_musl(x)]
    cgo_peers = []
    if args.cgo_peers is not None and len(args.cgo_peers) > 0:
        is_group = args.targ_os == 'linux'
        if is_group:
            cgo_peers.append('-Wl,--start-group')
        cgo_peers.extend(args.cgo_peers)
        if is_group:
            cgo_peers.append('-Wl,--end-group')
    try:
        index = extldflags.index('--cgo-peers')
        extldflags = extldflags[:index] + cgo_peers + extldflags[index+1:]
    except ValueError:
        extldflags.extend(cgo_peers)
    if len(extldflags) > 0:
        cmd.append('-extldflags={}'.format(' '.join(extldflags)))
    cmd.append(compile_args.output)
    call(cmd, args.build_root)


def gen_cover_info(args):
    lines = []
    lines.extend([
        """
var (
    coverCounters = make(map[string][]uint32)
    coverBlocks = make(map[string][]testing.CoverBlock)
)
        """,
        'func init() {',
    ])
    for var, file in (x.split(':') for x in args.cover_info):
        lines.append('    coverRegisterFile("{file}", _cover0.{var}.Count[:], _cover0.{var}.Pos[:], _cover0.{var}.NumStmt[:])'.format(file=file, var=var))
    lines.extend([
        '}',
        """
func coverRegisterFile(fileName string, counter []uint32, pos []uint32, numStmts []uint16) {
    if 3*len(counter) != len(pos) || len(counter) != len(numStmts) {
        panic("coverage: mismatched sizes")
    }
    if coverCounters[fileName] != nil {
        // Already registered.
        return
    }
    coverCounters[fileName] = counter
    block := make([]testing.CoverBlock, len(counter))
    for i := range counter {
        block[i] = testing.CoverBlock{
            Line0: pos[3*i+0],
            Col0: uint16(pos[3*i+2]),
            Line1: pos[3*i+1],
            Col1: uint16(pos[3*i+2]>>16),
            Stmts: numStmts[i],
        }
    }
    coverBlocks[fileName] = block
}
        """,
    ])
    return lines


def filter_out_skip_tests(tests, skip_tests):
    skip_set = set()
    star_skip_set = set()
    for t in skip_tests:
        work_set = star_skip_set if '*' in t else skip_set
        work_set.add(t)

    re_star_tests = None
    if len(star_skip_set) > 0:
        re_star_tests = re.compile(re.sub(r'(\*)+', r'.\1', '^({})$'.format('|'.join(star_skip_set))))

    return [x for x in tests if not (x in skip_tests or re_star_tests and re_star_tests.match(x))]


def gen_test_main(args, test_lib_args, xtest_lib_args):
    assert args and (test_lib_args or xtest_lib_args)
    test_miner = args.test_miner
    test_module_path = test_lib_args.import_path if test_lib_args else xtest_lib_args.import_path
    is_cover = args.cover_info and len(args.cover_info) > 0

    # Prepare GOPATH
    # $BINDIR
    #    |- __go__
    #        |- src
    #        |- pkg
    #            |- ${TARGET_OS}_${TARGET_ARCH}
    go_path_root = os.path.join(args.output_root, '__go__')
    test_src_dir = os.path.join(go_path_root, 'src')
    target_os_arch = '_'.join([args.targ_os, args.targ_arch])
    test_pkg_dir = os.path.join(go_path_root, 'pkg', target_os_arch, os.path.dirname(test_module_path))
    os.makedirs(test_pkg_dir)

    my_env = os.environ.copy()
    my_env['GOROOT'] = ''
    my_env['GOPATH'] = go_path_root
    my_env['GOARCH'] = args.targ_arch
    my_env['GOOS'] = args.targ_os

    tests = []
    xtests = []
    os_symlink = get_symlink_or_copyfile()

    # Get the list of "internal" tests
    if test_lib_args:
        os.makedirs(os.path.join(test_src_dir, test_module_path))
        os_symlink(test_lib_args.output, os.path.join(test_pkg_dir, os.path.basename(test_module_path) + '.a'))
        cmd = [test_miner, '-benchmarks', '-tests', test_module_path]
        tests = [x for x in (call(cmd, test_lib_args.output_root, my_env).decode('UTF-8') or '').strip().split('\n') if len(x) > 0]
        if args.skip_tests:
            tests = filter_out_skip_tests(tests, args.skip_tests)
    test_main_found = '#TestMain' in tests

    # Get the list of "external" tests
    if xtest_lib_args:
        xtest_module_path = xtest_lib_args.import_path
        os.makedirs(os.path.join(test_src_dir, xtest_module_path))
        os_symlink(xtest_lib_args.output, os.path.join(test_pkg_dir, os.path.basename(xtest_module_path) + '.a'))
        cmd = [test_miner, '-benchmarks', '-tests', xtest_module_path]
        xtests = [x for x in (call(cmd, xtest_lib_args.output_root, my_env).decode('UTF-8') or '').strip().split('\n') if len(x) > 0]
        if args.skip_tests:
            xtests = filter_out_skip_tests(xtests, args.skip_tests)
    xtest_main_found = '#TestMain' in xtests

    test_main_package = None
    if test_main_found and xtest_main_found:
        assert False, 'multiple definition of TestMain'
    elif test_main_found:
        test_main_package = '_test'
    elif xtest_main_found:
        test_main_package = '_xtest'

    shutil.rmtree(go_path_root)

    lines = ['package main', '', 'import (']
    if test_main_package is None:
        lines.append('    "os"')
    lines.extend(['    "testing"', '    "testing/internal/testdeps"'])

    if len(tests) > 0:
        lines.append('    _test "{}"'.format(test_module_path))
    elif test_lib_args:
        lines.append('    _ "{}"'.format(test_module_path))

    if len(xtests) > 0:
        lines.append('    _xtest "{}"'.format(xtest_module_path))
    elif xtest_lib_args:
        lines.append('    _ "{}"'.format(xtest_module_path))

    if is_cover:
        lines.append('    _cover0 "{}"'.format(test_module_path))
    lines.extend([')', ''])

    if compare_versions('1.18', args.goversion) < 0:
        kinds = ['Test', 'Benchmark', 'Example']
    else:
        kinds = ['Test', 'Benchmark', 'FuzzTarget', 'Example']

    var_names = []
    for kind in kinds:
        var_name = '{}s'.format(kind.lower())
        var_names.append(var_name)
        lines.append('var {} = []testing.Internal{}{{'.format(var_name, kind))
        for test in [x for x in tests if x.startswith(kind)]:
            lines.append('    {{"{test}", _test.{test}}},'.format(test=test))
        for test in [x for x in xtests if x.startswith(kind)]:
            lines.append('    {{"{test}", _xtest.{test}}},'.format(test=test))
        lines.extend(['}', ''])

    if is_cover:
        lines.extend(gen_cover_info(args))

    lines.append('func main() {')
    if is_cover:
        lines.extend([
            '    testing.RegisterCover(testing.Cover{',
            '        Mode: "set",',
            '        Counters: coverCounters,',
            '        Blocks: coverBlocks,',
            '        CoveredPackages: "",',
            '    })',
        ])
    lines.extend([
        '    m := testing.MainStart(testdeps.TestDeps{{}}, {})'.format(', '.join(var_names)),
        '',
    ])

    if test_main_package:
        lines.append('    {}.TestMain(m)'.format(test_main_package))
    else:
        lines.append('    os.Exit(m.Run())')
    lines.extend(['}', ''])

    content = '\n'.join(lines)
    # sys.stderr.write('{}\n'.format(content))
    return content


def do_link_test(args):
    assert args.srcs or args.xtest_srcs
    assert args.test_miner is not None

    test_module_path = get_source_path(args)
    test_import_path, _ = get_import_path(test_module_path)

    test_lib_args = copy_args(args) if args.srcs else None
    xtest_lib_args = copy_args(args) if args.xtest_srcs else None
    if xtest_lib_args is not None:
        xtest_lib_args.embed = args.embed_xtest if args.embed_xtest else None

    ydx_file_name = None
    xtest_ydx_file_name = None
    need_append_ydx = test_lib_args and xtest_lib_args and args.ydx_file and args.vet_flags
    if need_append_ydx:
        def find_ydx_file_name(name, flags):
            for i, elem in enumerate(flags):
                if elem.endswith(name):
                    return (i, elem)
            assert False, 'Unreachable code'

        idx, ydx_file_name = find_ydx_file_name(xtest_lib_args.ydx_file, xtest_lib_args.vet_flags)
        xtest_ydx_file_name = '{}_xtest'.format(ydx_file_name)
        xtest_lib_args.vet_flags = copy.copy(xtest_lib_args.vet_flags)
        xtest_lib_args.vet_flags[idx] = xtest_ydx_file_name

    if test_lib_args:
        test_lib_args.output = os.path.join(args.output_root, 'test.a')
        test_lib_args.vet_report_output = vet_report_output_name(test_lib_args.output)
        test_lib_args.module_path = test_module_path
        test_lib_args.import_path = test_import_path
        do_link_lib(test_lib_args)

    if xtest_lib_args:
        xtest_lib_args.srcs = xtest_lib_args.xtest_srcs
        classify_srcs(xtest_lib_args.srcs, xtest_lib_args)
        xtest_lib_args.output = os.path.join(args.output_root, 'xtest.a')
        xtest_lib_args.vet_report_output = vet_report_output_name(xtest_lib_args.output)
        xtest_lib_args.module_path = test_module_path + '_test'
        xtest_lib_args.import_path = test_import_path + '_test'
        if test_lib_args:
            xtest_lib_args.module_map[test_import_path] = test_lib_args.output
        need_append_ydx = args.ydx_file and args.srcs and args.vet_flags
        do_link_lib(xtest_lib_args)

    if need_append_ydx:
        with open(os.path.join(args.build_root, ydx_file_name), 'ab') as dst_file:
            with open(os.path.join(args.build_root, xtest_ydx_file_name), 'rb') as src_file:
                dst_file.write(src_file.read())

    test_main_content = gen_test_main(args, test_lib_args, xtest_lib_args)
    test_main_name = os.path.join(args.output_root, '_test_main.go')
    with open(test_main_name, "w") as f:
        f.write(test_main_content)
    test_args = copy_args(args)
    test_args.embed = None
    test_args.srcs = [test_main_name]
    if test_args.test_import_path is None:
        # it seems that we can do it unconditionally, but this kind
        # of mangling doesn't really looks good to me and we leave it
        # for pure GO_TEST module
        test_args.module_path = test_args.module_path + '___test_main__'
        test_args.import_path = test_args.import_path + '___test_main__'
    classify_srcs(test_args.srcs, test_args)
    if test_lib_args:
        test_args.module_map[test_lib_args.import_path] = test_lib_args.output
    if xtest_lib_args:
        test_args.module_map[xtest_lib_args.import_path] = xtest_lib_args.output

    if args.vet:
        dump_vet_report_for_tests(test_args, test_lib_args, xtest_lib_args)
    test_args.vet = False

    do_link_exe(test_args)


if __name__ == '__main__':
    args = pcf.get_args(sys.argv[1:])

    parser = argparse.ArgumentParser(prefix_chars='+')
    parser.add_argument('++mode', choices=['dll', 'exe', 'lib', 'test'], required=True)
    parser.add_argument('++srcs', nargs='*', required=True)
    parser.add_argument('++cgo-srcs', nargs='*')
    parser.add_argument('++test_srcs', nargs='*')
    parser.add_argument('++xtest_srcs', nargs='*')
    parser.add_argument('++cover_info', nargs='*')
    parser.add_argument('++output', nargs='?', default=None)
    parser.add_argument('++source-root', default=None)
    parser.add_argument('++build-root', required=True)
    parser.add_argument('++tools-root', default=None)
    parser.add_argument('++output-root', required=True)
    parser.add_argument('++toolchain-root', required=True)
    parser.add_argument('++host-os', choices=['linux', 'darwin', 'windows'], required=True)
    parser.add_argument('++host-arch', choices=['amd64', 'arm64'], required=True)
    parser.add_argument('++targ-os', choices=['linux', 'darwin', 'windows'], required=True)
    parser.add_argument('++targ-arch', choices=['amd64', 'x86', 'arm64'], required=True)
    parser.add_argument('++peers', nargs='*')
    parser.add_argument('++non-local-peers', nargs='*')
    parser.add_argument('++cgo-peers', nargs='*')
    parser.add_argument('++asmhdr', nargs='?', default=None)
    parser.add_argument('++test-import-path', nargs='?')
    parser.add_argument('++test-miner', nargs='?')
    parser.add_argument('++arc-project-prefix', nargs='?', default=arc_project_prefix)
    parser.add_argument('++std-lib-prefix', nargs='?', default=std_lib_prefix)
    parser.add_argument('++vendor-prefix', nargs='?', default=vendor_prefix)
    parser.add_argument('++extld', nargs='?', default=None)
    parser.add_argument('++extldflags', nargs='+', default=None)
    parser.add_argument('++goversion', required=True)
    parser.add_argument('++asm-flags', nargs='*')
    parser.add_argument('++compile-flags', nargs='*')
    parser.add_argument('++link-flags', nargs='*')
    parser.add_argument('++vcs', nargs='?', default=None)
    parser.add_argument('++vet', nargs='?', const=True, default=False)
    parser.add_argument('++vet-flags', nargs='*', default=None)
    parser.add_argument('++vet-info-ext', default=vet_info_ext)
    parser.add_argument('++vet-report-ext', default=vet_report_ext)
    parser.add_argument('++musl', action='store_true')
    parser.add_argument('++skip-tests', nargs='*', default=None)
    parser.add_argument('++ydx-file', default='')
    parser.add_argument('++debug-root-map', default=None)
    parser.add_argument('++embed', action='append', nargs='*')
    parser.add_argument('++embed_xtest', action='append', nargs='*')
    args = parser.parse_args(args)

    arc_project_prefix = args.arc_project_prefix
    std_lib_prefix = args.std_lib_prefix
    vendor_prefix = args.vendor_prefix
    vet_info_ext = args.vet_info_ext
    vet_report_ext = args.vet_report_ext

    preprocess_args(args)

    try:
        os.unlink(args.output)
    except OSError:
        pass

    # We are going to support only 'lib', 'exe' and 'cgo' build modes currently
    # and as a result we are going to generate only one build node per module
    # (or program)
    dispatch = {
        'exe': do_link_exe,
        'dll': do_link_exe,
        'lib': do_link_lib,
        'test': do_link_test
    }

    exit_code = 1
    try:
        dispatch[args.mode](args)
        exit_code = 0
    except KeyError:
        sys.stderr.write('Unknown build mode [{}]...\n'.format(args.mode))
    except subprocess.CalledProcessError as e:
        sys.stderr.write('{} returned non-zero exit code {}.\n{}\n'.format(' '.join(e.cmd), e.returncode, e.output))
        exit_code = e.returncode
    except Exception as e:
        sys.stderr.write('Unhandled exception [{}]...\n'.format(str(e)))
    sys.exit(exit_code)