1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
  137
  138
  139
  140
  141
  142
  143
  144
  145
  146
  147
  148
  149
  150
  151
  152
  153
  154
  155

build / gn_ast / jni_refactor.py [blame]

# Copyright 2023 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Refactors BUILD.gn files for our Annotation Processor -> .srcjar migration.

1) Finds all generate_jni() targets
2) Finds all android_library() targets with that use ":jni_processor"
3) Compares lists of sources between them
4) Removes the annotation_processor_deps entry
5) Adds the generate_jni target as a srcjar_dep
6) Updates visibility of generate_jni to allow the dep

This script has already done its job, but is left as an example of using gn_ast.
"""

import argparse
import sys

import gn_ast

_PROCESSOR_DEP = '//base/android/jni_generator:jni_processor'


class RefactorException(Exception):
    pass


def find_processor_assignment(target):
    for assignment in target.block.find_assignments(
            'annotation_processor_deps'):
        processors = assignment.list_value.literals
        if _PROCESSOR_DEP in processors:
            return assignment
    return None


def find_all_sources(target, build_file):
    ret = []

    def helper(assignments):
        for assignment in assignments:
            if assignment.operation not in ('=', '+='):
                raise RefactorException(
                    f'{target.name}: sources has a {assignment.operation}.')

            value = assignment.value
            if value.is_identifier():
                helper(build_file.block.find_assignments(value.node_value))
            elif not value.is_list():
                raise RefactorException(f'{target.name}: sources not a list.')
            else:
                ret.extend(value.literals)

    helper(target.block.find_assignments('sources'))
    return ret


def find_matching_jni_target(library_target, jni_target_to_sources,
                             build_file):
    all_sources = set(find_all_sources(library_target, build_file))
    matches = []
    for jni_target_name, jni_sources in jni_target_to_sources.items():
        if all(s in all_sources for s in jni_sources):
            matches.append(jni_target_name)
    if len(matches) == 1:
        return matches[0]
    if len(matches) > 1:
        raise RefactorException(
            f'{library_target.name}: Matched multiple generate_jni().')
    if jni_target_to_sources:
        raise RefactorException(
            f'{library_target.name}: No matching generate_jni().')
    raise RefactorException('No sources found for generate_jni().')


def fix_visibility(target):
    for assignment in target.block.find_assignments('visibility'):
        if not assignment.value.is_list():
            continue
        list_value = assignment.list_value
        for value in list(list_value.literals):
            if value.startswith(':'):
                list_value.remove_literal(value)
        list_value.add_literal(':*')


def refactor(lib_target, jni_target):
    assignments = lib_target.block.find_assignments('srcjar_deps')
    srcjar_deps = assignments[0] if assignments else None
    if srcjar_deps is None:
        srcjar_deps = gn_ast.AssignmentWrapper.create_list('srcjar_deps')
        first_source_assignment = lib_target.block.find_assignments(
            'sources')[0]
        lib_target.block.add_child(srcjar_deps, before=first_source_assignment)
    elif not srcjar_deps.value.is_list():
        raise RefactorException(
            f'{lib_target.name}: srcjar_deps is not a list.')
    srcjar_deps.list_value.add_literal(f':{jni_target.name}')

    processor_assignment = find_processor_assignment(lib_target)
    processors = processor_assignment.list_value.literals
    if len(processors) == 1:
        lib_target.block.remove_child(processor_assignment.node)
    else:
        processor_assignment.list_value.remove_literal(_PROCESSOR_DEP)

    fix_visibility(jni_target)


def analyze(build_file):
    targets = build_file.targets
    jni_targets = [t for t in targets if t.type == 'generate_jni']
    lib_targets = [t for t in targets if find_processor_assignment(t)]

    if len(jni_targets) == 0 and len(lib_targets) == 0:
        return
    # Match up target when there are only one, even when targets use variables
    # for list values.
    if len(jni_targets) == 1 and len(lib_targets) == 1:
        refactor(lib_targets[0], jni_targets[0])
        return

    jni_target_to_sources = {
        t.name: find_all_sources(t, build_file)
        for t in jni_targets
    }
    for lib_target in lib_targets:
        jni_target_name = find_matching_jni_target(lib_target,
                                                   jni_target_to_sources,
                                                   build_file)
        jni_target = build_file.targets_by_name[jni_target_name]
        refactor(lib_target, jni_target)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('path')
    args = parser.parse_args()
    try:
        build_file = gn_ast.BuildFile.from_file(args.path)
        analyze(build_file)
        if build_file.write_changes():
            print(f'{args.path}: Changes applied.')
        else:
            print(f'{args.path}: No changes necessary.')
    except RefactorException as e:
        print(f'{args.path}: {e}')
        sys.exit(1)
    except Exception:
        print('Failure on', args.path)
        raise


if __name__ == '__main__':
    main()