scripts/kernel-doc.py: move regex methods to a separate file (e31fd36d) · Commits · git / linux-net

scripts/kernel-doc.py

+5 −218

Original line number	Diff line number	Diff line
		@@ -110,228 +110,15 @@ from pprint import pformat

		from dateutil import tz

		# Local cache for regular expressions
		re_cache = {}
		# Import Python modules

		LIB_DIR = "lib/kdoc"
		SRC_DIR = os.path.dirname(os.path.realpath(__file__))

		class Re:
		"""
		Helper class to simplify regex declaration and usage,

		It calls re.compile for a given pattern. It also allows adding
		regular expressions and define sub at class init time.

		Regular expressions can be cached via an argument, helping to speedup
		searches.
		"""

		def _add_regex(self, string, flags):
		if string in re_cache:
		self.regex = re_cache[string]
		else:
		self.regex = re.compile(string, flags=flags)

		if self.cache:
		re_cache[string] = self.regex

		def __init__(self, string, cache=True, flags=0):
		self.cache = cache
		self.last_match = None

		self._add_regex(string, flags)

		def __str__(self):
		return self.regex.pattern

		def __add__(self, other):
		return Re(str(self) + str(other), cache=self.cache or other.cache,
		flags=self.regex.flags \| other.regex.flags)

		def match(self, string):
		self.last_match = self.regex.match(string)
		return self.last_match

		def search(self, string):
		self.last_match = self.regex.search(string)
		return self.last_match

		def findall(self, string):
		return self.regex.findall(string)

		def split(self, string):
		return self.regex.split(string)

		def sub(self, sub, string, count=0):
		return self.regex.sub(sub, string, count=count)

		def group(self, num):
		return self.last_match.group(num)

		class NestedMatch:
		"""
		Finding nested delimiters is hard with regular expressions. It is
		even harder on Python with its normal re module, as there are several
		advanced regular expressions that are missing.

		This is the case of this pattern:

		'\\bSTRUCT_GROUP(\\(((?:(?>[^)(]+)\|(?1)))\\))[^;];'

		which is used to properly match open/close parenthesis of the
		string search STRUCT_GROUP(),

		Add a class that counts pairs of delimiters, using it to match and
		replace nested expressions.

		The original approach was suggested by:
		https://stackoverflow.com/questions/5454322/python-how-to-match-nested-parentheses-with-regex

		Although I re-implemented it to make it more generic and match 3 types
		of delimiters. The logic checks if delimiters are paired. If not, it
		will ignore the search string.
		"""

		# TODO:
		# Right now, regular expressions to match it are defined only up to
		# the start delimiter, e.g.:
		#
		# \bSTRUCT_GROUP\(
		#
		# is similar to: STRUCT_GROUP\((.*)\)
		# except that the content inside the match group is delimiter's aligned.
		#
		# The content inside parenthesis are converted into a single replace
		# group (e.g. r`\1').
		#
		# It would be nice to change such definition to support multiple
		# match groups, allowing a regex equivalent to.
		#
		# FOO\((.), (.), (.*)\)
		#
		# it is probably easier to define it not as a regular expression, but
		# with some lexical definition like:
		#
		# FOO(arg1, arg2, arg3)


		DELIMITER_PAIRS = {
		'{': '}',
		'(': ')',
		'[': ']',
		}

		RE_DELIM = re.compile(r'[\{\}\[\]\(\)]')

		def _search(self, regex, line):
		"""
		Finds paired blocks for a regex that ends with a delimiter.

		The suggestion of using finditer to match pairs came from:
		https://stackoverflow.com/questions/5454322/python-how-to-match-nested-parentheses-with-regex
		but I ended using a different implementation to align all three types
		of delimiters and seek for an initial regular expression.

		The algorithm seeks for open/close paired delimiters and place them
		into a stack, yielding a start/stop position of each match when the
		stack is zeroed.

		The algorithm shoud work fine for properly paired lines, but will
		silently ignore end delimiters that preceeds an start delimiter.
		This should be OK for kernel-doc parser, as unaligned delimiters
		would cause compilation errors. So, we don't need to rise exceptions
		to cover such issues.
		"""

		stack = []

		for match_re in regex.finditer(line):
		start = match_re.start()
		offset = match_re.end()

		d = line[offset -1]
		if d not in self.DELIMITER_PAIRS:
		continue

		end = self.DELIMITER_PAIRS[d]
		stack.append(end)

		for match in self.RE_DELIM.finditer(line[offset:]):
		pos = match.start() + offset

		d = line[pos]

		if d in self.DELIMITER_PAIRS:
		end = self.DELIMITER_PAIRS[d]

		stack.append(end)
		continue

		# Does the end delimiter match what it is expected?
		if stack and d == stack[-1]:
		stack.pop()

		if not stack:
		yield start, offset, pos + 1
		break

		def search(self, regex, line):
		"""
		This is similar to re.search:

		It matches a regex that it is followed by a delimiter,
		returning occurrences only if all delimiters are paired.
		"""

		for t in self._search(regex, line):

		yield line[t[0]:t[2]]

		def sub(self, regex, sub, line, count=0):
		"""
		This is similar to re.sub:

		It matches a regex that it is followed by a delimiter,
		replacing occurrences only if all delimiters are paired.

		if r'\1' is used, it works just like re: it places there the
		matched paired data with the delimiter stripped.

		If count is different than zero, it will replace at most count
		items.
		"""
		out = ""

		cur_pos = 0
		n = 0

		found = False
		for start, end, pos in self._search(regex, line):
		out += line[cur_pos:start]

		# Value, ignoring start/end delimiters
		value = line[end:pos - 1]

		# replaces \1 at the sub string, if \1 is used there
		new_sub = sub
		new_sub = new_sub.replace(r'\1', value)

		out += new_sub

		# Drop end ';' if any
		if line[pos] == ';':
		pos += 1

		cur_pos = pos
		n += 1

		if count and count >= n:
		break
		sys.path.insert(0, os.path.join(SRC_DIR, LIB_DIR))

		# Append the remaining string
		l = len(line)
		out += line[cur_pos:l]
		from kdoc_re import Re, NestedMatch

		return out

		#
		# Regular expressions used to parse kernel-doc markups at KernelDoc class.

scripts/lib/kdoc/kdoc_re.py

0 → 100755

+272 −0

Original line number	Diff line number	Diff line
		#!/usr/bin/env python3
		# SPDX-License-Identifier: GPL-2.0
		# Copyright(c) 2025: Mauro Carvalho Chehab <mchehab@kernel.org>.

		"""
		Regular expression ancillary classes.

		Those help caching regular expressions and do matching for kernel-doc.
		"""

		import re

		# Local cache for regular expressions
		re_cache = {}


		class Re:
		"""
		Helper class to simplify regex declaration and usage,

		It calls re.compile for a given pattern. It also allows adding
		regular expressions and define sub at class init time.

		Regular expressions can be cached via an argument, helping to speedup
		searches.
		"""

		def _add_regex(self, string, flags):
		"""
		Adds a new regex or re-use it from the cache.
		"""

		if string in re_cache:
		self.regex = re_cache[string]
		else:
		self.regex = re.compile(string, flags=flags)

		if self.cache:
		re_cache[string] = self.regex

		def __init__(self, string, cache=True, flags=0):
		"""
		Compile a regular expression and initialize internal vars.
		"""

		self.cache = cache
		self.last_match = None

		self._add_regex(string, flags)

		def __str__(self):
		"""
		Return the regular expression pattern.
		"""
		return self.regex.pattern

		def __add__(self, other):
		"""
		Allows adding two regular expressions into one.
		"""

		return Re(str(self) + str(other), cache=self.cache or other.cache,
		flags=self.regex.flags \| other.regex.flags)

		def match(self, string):
		"""
		Handles a re.match storing its results
		"""

		self.last_match = self.regex.match(string)
		return self.last_match

		def search(self, string):
		"""
		Handles a re.search storing its results
		"""

		self.last_match = self.regex.search(string)
		return self.last_match

		def findall(self, string):
		"""
		Alias to re.findall
		"""

		return self.regex.findall(string)

		def split(self, string):
		"""
		Alias to re.split
		"""

		return self.regex.split(string)

		def sub(self, sub, string, count=0):
		"""
		Alias to re.sub
		"""

		return self.regex.sub(sub, string, count=count)

		def group(self, num):
		"""
		Returns the group results of the last match
		"""

		return self.last_match.group(num)


		class NestedMatch:
		"""
		Finding nested delimiters is hard with regular expressions. It is
		even harder on Python with its normal re module, as there are several
		advanced regular expressions that are missing.

		This is the case of this pattern:

		'\\bSTRUCT_GROUP(\\(((?:(?>[^)(]+)\|(?1)))\\))[^;];'

		which is used to properly match open/close parenthesis of the
		string search STRUCT_GROUP(),

		Add a class that counts pairs of delimiters, using it to match and
		replace nested expressions.

		The original approach was suggested by:
		https://stackoverflow.com/questions/5454322/python-how-to-match-nested-parentheses-with-regex

		Although I re-implemented it to make it more generic and match 3 types
		of delimiters. The logic checks if delimiters are paired. If not, it
		will ignore the search string.
		"""

		# TODO:
		# Right now, regular expressions to match it are defined only up to
		# the start delimiter, e.g.:
		#
		# \bSTRUCT_GROUP\(
		#
		# is similar to: STRUCT_GROUP\((.*)\)
		# except that the content inside the match group is delimiter's aligned.
		#
		# The content inside parenthesis are converted into a single replace
		# group (e.g. r`\1').
		#
		# It would be nice to change such definition to support multiple
		# match groups, allowing a regex equivalent to.
		#
		# FOO\((.), (.), (.*)\)
		#
		# it is probably easier to define it not as a regular expression, but
		# with some lexical definition like:
		#
		# FOO(arg1, arg2, arg3)

		DELIMITER_PAIRS = {
		'{': '}',
		'(': ')',
		'[': ']',
		}

		RE_DELIM = re.compile(r'[\{\}\[\]\(\)]')

		def _search(self, regex, line):
		"""
		Finds paired blocks for a regex that ends with a delimiter.

		The suggestion of using finditer to match pairs came from:
		https://stackoverflow.com/questions/5454322/python-how-to-match-nested-parentheses-with-regex
		but I ended using a different implementation to align all three types
		of delimiters and seek for an initial regular expression.

		The algorithm seeks for open/close paired delimiters and place them
		into a stack, yielding a start/stop position of each match when the
		stack is zeroed.

		The algorithm shoud work fine for properly paired lines, but will
		silently ignore end delimiters that preceeds an start delimiter.
		This should be OK for kernel-doc parser, as unaligned delimiters
		would cause compilation errors. So, we don't need to rise exceptions
		to cover such issues.
		"""

		stack = []

		for match_re in regex.finditer(line):
		start = match_re.start()
		offset = match_re.end()

		d = line[offset - 1]
		if d not in self.DELIMITER_PAIRS:
		continue

		end = self.DELIMITER_PAIRS[d]
		stack.append(end)

		for match in self.RE_DELIM.finditer(line[offset:]):
		pos = match.start() + offset

		d = line[pos]

		if d in self.DELIMITER_PAIRS:
		end = self.DELIMITER_PAIRS[d]

		stack.append(end)
		continue

		# Does the end delimiter match what it is expected?
		if stack and d == stack[-1]:
		stack.pop()

		if not stack:
		yield start, offset, pos + 1
		break

		def search(self, regex, line):
		"""
		This is similar to re.search:

		It matches a regex that it is followed by a delimiter,
		returning occurrences only if all delimiters are paired.
		"""

		for t in self._search(regex, line):

		yield line[t[0]:t[2]]

		def sub(self, regex, sub, line, count=0):
		"""
		This is similar to re.sub:

		It matches a regex that it is followed by a delimiter,
		replacing occurrences only if all delimiters are paired.

		if r'\1' is used, it works just like re: it places there the
		matched paired data with the delimiter stripped.

		If count is different than zero, it will replace at most count
		items.
		"""
		out = ""

		cur_pos = 0
		n = 0

		for start, end, pos in self._search(regex, line):
		out += line[cur_pos:start]

		# Value, ignoring start/end delimiters
		value = line[end:pos - 1]

		# replaces \1 at the sub string, if \1 is used there
		new_sub = sub
		new_sub = new_sub.replace(r'\1', value)

		out += new_sub

		# Drop end ';' if any
		if line[pos] == ';':
		pos += 1

		cur_pos = pos
		n += 1

		if count and count >= n:
		break

		# Append the remaining string
		l = len(line)
		out += line[cur_pos:l]

		return out