Get all deps and hooks exclusive to Chromium on Android

get_android_deps.py

#!/usr/bin/env python3
# -*- coding: UTF-8 -*-

"""
Prints out the deps and hooks exclusive to Chromium for Android 

Usage: get_android_deps.py path/to/DEPS
"""

import ast
import sys

class _UnexpectedSyntax(RuntimeError):
    """Raised when unexpected syntax is used in DEPS"""
    pass

class _DepsNodeVisitor(ast.NodeVisitor):
    _valid_syntax_types = (
        ast.mod, ast.expr_context, ast.boolop,
        ast.Assign, ast.Add, ast.Name, ast.Dict, ast.Str, ast.NameConstant,
        ast.List, ast.BinOp
    )
    _allowed_callables = ('Var',)

    def visit_Call(self, node):
        if node.func.id not in self._allowed_callables:
            raise _UnexpectedSyntax(
                'Unexpected call of "%s" at line %s, column %s' % (
                    node.func.id, node.lineno, node.col_offset))

    def generic_visit(self, node):
        for ast_type in self._valid_syntax_types:
            if isinstance(node, ast_type):
                super().generic_visit(node)
                return
        raise _UnexpectedSyntax(
            'Unexpected {} at line {}, column {}'.format(
                type(node).__name__, node.lineno, node.col_offset))

def _validate_deps(deps_text):
    """Returns True if the DEPS file passes validation; False otherwise"""
    try:
        _DepsNodeVisitor().visit(ast.parse(deps_text))
    except _UnexpectedSyntax as exc:
        print('ERROR: %s' % exc)
        return False
    return True

def _deps_var(deps_globals):
    """Return a function that implements DEPS's Var() function"""
    def _var_impl(var_name):
        """Implementation of Var() in DEPS"""
        return deps_globals['vars'][var_name]
    return _var_impl

def _parse_deps(deps_text):
    """Returns a dict of parsed DEPS data"""
    deps_globals = {'__builtins__': None}
    deps_globals['Var'] = _deps_var(deps_globals)
    exec(deps_text, deps_globals)
    return deps_globals

def _get_android_deps(parsed_deps):
    """Yields deps that are needed only by Android"""
    recursive_deps = dict()
    for recurse_dep in parsed_deps['recursedeps']:
        if isinstance(recurse_dep, str):
            recursive_deps[recurse_dep] = 'DEPS'
        elif isinstance(recurse_dep, list):
            recursive_deps[recurse_dep[0]] = recurse_dep[1]
        else:
            raise ValueError('Unexpected recursedeps value: %s' % recurse_dep)
    for dep_name, dep_def in parsed_deps['deps'].items():
        if isinstance(dep_def, str):
            # This is just a URL, so skip it
            continue
        condition = dep_def.get('condition', '')
        if 'checkout_linux' not in condition and 'checkout_android' in condition:
            yield dep_name, dep_def, recursive_deps.get(dep_name)

def _get_android_hooks(parsed_deps):
    """Yields hooks that are needed only by Android"""
    for hook in parsed_deps['hooks']:
        condition = hook.get('condition', '')
        if 'checkout_linux' not in condition and 'checkout_android' in condition:
            yield hook['name'], hook

def main(args):
    assert len(args) == 1
    with open(args[0]) as deps_file:
        deps_text = deps_file.read()
    if not _validate_deps(deps_text):
        print('ERROR: DEPS does not pass validation. Aborting.')
        return 1
    parsed_deps = _parse_deps(deps_text)
    print('***Dependencies:')
    for dep_name, dep_def, recurse_dep in sorted(_get_android_deps(parsed_deps)):
        if recurse_dep:
            print(dep_name, '(Contains additional deps file: %s)' % recurse_dep)
        else:
            print(dep_name)
    print('***Hooks:')
    for hook_name, hook in sorted(_get_android_hooks(parsed_deps)):
        print(hook_name)
    return 0

if __name__ == '__main__':
    exit(main(sys.argv[1:]))