1# SPDX-License-Identifier: GPL-2.0
2#
3# Builds a .config from a kunitconfig.
4#
5# Copyright (C) 2019, Google LLC.
6# Author: Felix Guo <felixguoxiuping@gmail.com>
7# Author: Brendan Higgins <brendanhiggins@google.com>
8
9from dataclasses import dataclass
10import re
11from typing import List, Set
12
13CONFIG_IS_NOT_SET_PATTERN = r'^# CONFIG_(\w+) is not set$'
14CONFIG_PATTERN = r'^CONFIG_(\w+)=(\S+|".*")$'
15
16@dataclass(frozen=True)
17class KconfigEntry:
18	name: str
19	value: str
20
21	def __str__(self) -> str:
22		if self.value == 'n':
23			return f'# CONFIG_{self.name} is not set'
24		return f'CONFIG_{self.name}={self.value}'
25
26
27class KconfigParseError(Exception):
28	"""Error parsing Kconfig defconfig or .config."""
29
30
31class Kconfig:
32	"""Represents defconfig or .config specified using the Kconfig language."""
33
34	def __init__(self) -> None:
35		self._entries = []  # type: List[KconfigEntry]
36
37	def entries(self) -> Set[KconfigEntry]:
38		return set(self._entries)
39
40	def add_entry(self, entry: KconfigEntry) -> None:
41		self._entries.append(entry)
42
43	def is_subset_of(self, other: 'Kconfig') -> bool:
44		other_dict = {e.name: e.value for e in other.entries()}
45		for a in self.entries():
46			b = other_dict.get(a.name)
47			if b is None:
48				if a.value == 'n':
49					continue
50				return False
51			if a.value != b:
52				return False
53		return True
54
55	def merge_in_entries(self, other: 'Kconfig') -> None:
56		if other.is_subset_of(self):
57			return
58		self._entries = list(self.entries().union(other.entries()))
59
60	def write_to_file(self, path: str) -> None:
61		with open(path, 'a+') as f:
62			for entry in self.entries():
63				f.write(str(entry) + '\n')
64
65def parse_file(path: str) -> Kconfig:
66	with open(path, 'r') as f:
67		return parse_from_string(f.read())
68
69def parse_from_string(blob: str) -> Kconfig:
70	"""Parses a string containing Kconfig entries."""
71	kconfig = Kconfig()
72	is_not_set_matcher = re.compile(CONFIG_IS_NOT_SET_PATTERN)
73	config_matcher = re.compile(CONFIG_PATTERN)
74	for line in blob.split('\n'):
75		line = line.strip()
76		if not line:
77			continue
78
79		match = config_matcher.match(line)
80		if match:
81			entry = KconfigEntry(match.group(1), match.group(2))
82			kconfig.add_entry(entry)
83			continue
84
85		empty_match = is_not_set_matcher.match(line)
86		if empty_match:
87			entry = KconfigEntry(empty_match.group(1), 'n')
88			kconfig.add_entry(entry)
89			continue
90
91		if line[0] == '#':
92			continue
93		raise KconfigParseError('Failed to parse: ' + line)
94	return kconfig
95