Tools/Scripts/strip-tbd

#!/usr/bin/env python3

import argparse
import collections
import yaml
import os
import tempfile

parser = argparse.ArgumentParser(description='subset of strip(1) for manipulating symbol tables in text-based API stubs')
parser.add_argument('input', type=argparse.FileType('r'), nargs='+', help='TBDs to strip')
group = parser.add_mutually_exclusive_group()
group.add_argument('-s', type=argparse.FileType('r'), dest='save_list', help='save the symbols listed in the file given')
group.add_argument('-R', type=argparse.FileType('r'), dest='remove_list', help='remove the symbols listed in the file given')

OPTS = parser.parse_args()
SELECTED_SYMBOLS = set()
STRIP_SELECTED = bool(OPTS.remove_list)

fd = OPTS.save_list or OPTS.remove_list
if fd:
    for line in fd:
        line = line.strip()
        if line and not line.startswith('#'):
            SELECTED_SYMBOLS.add(line)

# FIXME: handle JSON-based TBD format (v5)
class TBD(yaml.YAMLObject):
    yaml_tag = '!tapi-tbd'

    def __repr__(self):
        return 'TBD(version={tbd-version}, {install-name})'.format_map(self.__dict__)

    @classmethod
    def to_yaml(cls, dumper, data):
        dumper.sort_keys = False
        mapping = super().to_yaml(dumper, data)
        # Selectively enable flow layout to mimic LLVM formatting.
        def walk_and_set_flow_style(node):
            if isinstance(node, yaml.nodes.SequenceNode):
                only_scalar = True
                for n in node.value:
                    only_scalar &= walk_and_set_flow_style(n)
                if only_scalar:
                    node.flow_style = True
                return False
            elif isinstance(node, yaml.nodes.MappingNode):
                for k, v in node.value:
                    walk_and_set_flow_style(v)
                return False
            else:
                node.flow_style = True
                return True
        walk_and_set_flow_style(mapping)
        return mapping

for tbd_fd in OPTS.input:
    updated_tbds = []
    for tbd in yaml.unsafe_load_all(tbd_fd):
        new_exports = []
        while getattr(tbd, 'exports', None):
            export_list = tbd.exports.pop()
            write_back = False

            for key, predicate in (
                # field name     # whether value represents a selected symbol
                ('symbols',      lambda x: x in SELECTED_SYMBOLS),
                ('weak-symbols', lambda x: x in SELECTED_SYMBOLS),
                ('objc-classes', lambda x: f'_OBJC_CLASS_$_{x}' in SELECTED_SYMBOLS or f'_OBJC_METACLASS_$_{x}' in SELECTED_SYMBOLS),
                ('objc-ivars',   lambda x: f'_OBJC_IVAR_$_{x}' in SELECTED_SYMBOLS),
            ):
                if not key in export_list:
                    continue
                filtered = [name for name in export_list[key] if predicate(name) ^ STRIP_SELECTED]
                if filtered:
                    export_list[key] = filtered
                    write_back = True
                else:
                    del export_list[key]

            if write_back:
                new_exports.append(export_list)
        tbd.exports = new_exports
        if hasattr(tbd, 'allowable-clients'):
            # Stub TBDs in WebKit aren't part of a real SDK, no need to care
            # about who links against them.
            delattr(tbd, 'allowable-clients')
        updated_tbds.append(tbd)

    output_dir, output_basename = os.path.split(tbd_fd.name)
    output_fd, output_name = tempfile.mkstemp(prefix=f'.{output_basename}', dir=output_dir)
    output_fd = os.fdopen(output_fd, 'w')
    yaml.dump_all(updated_tbds, output_fd, width=120, indent=8, explicit_start=True, explicit_end=True)
    os.replace(output_name, tbd_fd.name)