buildorder.py: wrap main()

[termux-packages] / buildorder.py

#!/usr/bin/env python3
# buildorder.py - script to generate a build order respecting package dependencies

import os
import sys


def die(msg):
    sys.exit('ERROR: ' + msg)


if len(sys.argv) != 1:
    die('buildorder.py takes no arguments')


class DebianPackage(object):
    def __init__(self, name):
        self.name = name
        self.remaining_dependencies = set()  # String
        self.sub_packages = set()  # String
        self.prerequisite_for = set()  # Packages that needs this package

# List of all DebianPackage:s
all_packages = []

# Mapping from package name to DebianPackage
# (if subpackage, mapping from subpackage name to parent package)
packages_map = {}

packages_dir = 'packages'


def main():
    for subdir_name in sorted(os.listdir(packages_dir)):
        subdir_path = packages_dir + '/' + subdir_name

        if os.path.exists(subdir_path + '/BROKEN.txt'):
            continue

        build_sh_path = subdir_path + '/build.sh'

        this_package = DebianPackage(subdir_name)
        all_packages.append(this_package)
        packages_map[this_package.name] = this_package

        if not os.path.isfile(build_sh_path):
            die('The directory ' + subdir_name + ' does not contain build.sh')

        with open(build_sh_path) as build_sh_file:
            for line in build_sh_file:
                if line.startswith('TERMUX_PKG_DEPENDS='):
                    deps_comma_separated = line[(line.index('=')+2):(len(line)-2)]
                    for dep in deps_comma_separated.split(','):
                        dep = dep.strip()
                        if not dep.endswith('libandroid-support-dev'):
                            this_package.remaining_dependencies.add(dep)

        for file_in_subdir_name in sorted(os.listdir(subdir_path)):
            if file_in_subdir_name.endswith('.subpackage.sh'):
                subpackage_name = file_in_subdir_name[0:-len(".subpackage.sh"):]
                this_package.sub_packages.add(subpackage_name)
                packages_map[subpackage_name] = this_package
                with open(subdir_path + '/' + file_in_subdir_name) as subpackage_sh_file:
                    for line in subpackage_sh_file:
                        if line.startswith('TERMUX_SUBPKG_DEPENDS='):
                            deps_comma_separated = line[(line.index('=')+2):(len(line)-2)]
                            for dep in deps_comma_separated.split(','):
                                dep = dep.strip()
                                this_package.remaining_dependencies.add(dep)
        # Do not depend on itself
        this_package.remaining_dependencies.discard(this_package.name)
        # Do not depend on any sub package
        this_package.remaining_dependencies.difference_update(this_package.sub_packages)

    for package in all_packages:
        for remaining in package.remaining_dependencies:
            if remaining not in packages_map:
                die('Package %s depends on non-existing package "%s"' % (
                 package.name, remaining
                ))
            packages_map[remaining].prerequisite_for.add(package)

    # List of all DebianPackage:s without dependencies
    packages_without_deps = [p for p in all_packages if not p.remaining_dependencies]
    if not packages_without_deps:
        die('No package without dependency - where to start?')

    # Sort alphabetically, but with libandroid-support first (since dependency on libandroid-support
    # does not need to be declared explicitly, so anything might in theory depend on it to build):

    packages_without_deps.sort(
        key=lambda p: '' if p.name == 'libandroid-support' else p.name,
        reverse=True)

    # Topological sorting
    build_order = []
    while packages_without_deps:
        pkg = packages_without_deps.pop()
        build_order.append(pkg)
        for other_package in pkg.prerequisite_for:
            # Remove this package
            other_package.remaining_dependencies.discard(pkg.name)
            # .. and all its subpackages
            other_package.remaining_dependencies.difference_update(pkg.sub_packages)
            if not other_package.remaining_dependencies:
                # Check if the other package is ready to build now
                packages_without_deps.append(other_package)

    if len(all_packages) != len(build_order):
        print("ERROR: Cycle exists. Remaining: ")
        for pkg in all_packages:
            if pkg not in build_order:
                print(pkg.name)
        sys.exit(1)

    for pkg in build_order:
        print(pkg.name)

if __name__ == '__main__':
    main()