Please auto go.mod

go.build_defs.py

def _set_go_env():
    if CONFIG.GOROOT:
        go_root = CONFIG.GOROOT
    elif CONFIG.HOSTOS == 'freebsd':
        # FreeBSD has some very strange semantics around hardlinks that lead to it finding
        # the wrong thing (essentially os.Executable, which go uses to define GOROOT, returns
        # the most recent hardlink to the file). We can work around this way although it's
        # not very nice (we don't do this globally because OSX doesn't have realpath).
        go_root = f'$(dirname $(dirname $(realpath $TOOLS_GO)))'
    else:
        go_root = '$("$TOOLS_GO" env GOROOT)'
    cmd = f'export GOPATH=$TMP_DIR && export GOROOT={go_root}'
    if CONFIG.CGO_ENABLED:
        return f'export CGO_ENABLED={CONFIG.CGO_ENABLED} && {cmd}'
    return cmd
    
def go_globall(test=False):
    return glob(["**/*.go"], exclude = ["*_test.go"] if test else None)

def go_mod(name, visibility, deps=None):
    aggreg_name = name

    def module_to_target(m):
        return m.replace('/', '_')

    def _parse_mod_mod(line):
        mod, version, depss = line.split(' ')
        deps = depss.split('|') if depss else []
        return mod, version, deps

    def _mod_mod(_, output):
        for i, line in enumerate(output):
            mod, version, deps = _parse_mod_mod(line)
            mod_target = module_to_target(mod)

            target_deps = [(":"+module_to_target(d)) for d in deps]

            log.error(f'{mod} {version} {target_deps}')

            if i == 0:
                mod = go_library(
                    name = mod_target+"#lib",
                    srcs = ['.'],
                    deps = target_deps,
                )
            else:
                moddl = go_mod_download(
                    name = mod_target+"#dl",
                    module = mod,
                    version = version,
                )

                mod = go_module(
                    name = mod_target,
                    module = mod,
                    download = moddl,
                    deps = target_deps,
                    exported_deps = target_deps,
                    install = None,
                )

            add_exported_dep(aggreg_name, mod)

    builddeps = genrule(
        name = name+"#builddeps",
        srcs = {"modpy": ["//build_defs:mod.py"], "d": ["go.mod", "go.sum"]},
        deps = deps,
        cmd = [
            _set_go_env(),
            "$TOOLS_PYTHON $SRCS_MODPY",
        ],
        tools = {
            "go": CONFIG.GO_TOOL,
            "jq": "//tools:jq|jq",
            "python": CONFIG.DEFAULT_PYTHON_INTERPRETER,
        },
        post_build = _mod_mod,
    )

    return filegroup(
        name = aggreg_name,
        deps = [builddeps],
    )

mod.py

import subprocess
import os

pkg_dir = os.getcwd()+"/"+os.getenv('PKG_DIR')

def remove_prefix(str, prefix):
    if str.startswith(prefix):
        return str[len(prefix):]
    else:
        return str

module = None
gomod = open(pkg_dir+'/go.mod')
for line in gomod.readlines():
    if line.startswith("module"):
        module = remove_prefix(line, "module").strip()
        break

if not module:
    die("cannot guess module")

moddl = subprocess.check_output("$TOOLS_GO mod download -modcacherw -json | $TOOLS_JQ -r '(.Path + \"@\" + .Version)'", shell=True, cwd=pkg_dir).decode("ascii",errors="ignore").splitlines()
modgraph = subprocess.check_output("$TOOLS_GO mod graph", shell=True, cwd=pkg_dir).decode("ascii",errors="ignore").splitlines()

depsm = {}
depsm[module] = {'version': 'v0.0.0', 'deps': set()}

for line in moddl:
    mod, version = line.split('@')
    depsm[mod] = {'version': version, 'deps': set()}

for line in modgraph:
    mod_ref, dep_ref = line.split(' ')

    mod_parts = mod_ref.split('@')
    mod = mod_parts[0]

    dep_parts = dep_ref.split('@')
    dep = dep_parts[0]

    assert mod in depsm, "Missing entry for mod: "+mod
    assert dep in depsm, "Missing entry for dep: "+dep
    entry = depsm[mod]
    
    entry['deps'].add(dep)

def print_entry(mod, e):
    version = e['version']
    deps = '|'.join(e['deps'])
    print(f'{mod} {version} {deps}')

print_entry(module, depsm[module])

for mod, entry in depsm.items():
    if mod == module:
        continue

    print_entry(mod, entry)