[PATCH v2 16/28] docs: kdoc_re: get rid of NestedMatch class

Mauro Carvalho Chehab
2026-03-12T14:55:00Z

Now that everything was converted to CMatch, we can get rid of
the previous NestedMatch implementation.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
tools/lib/python/kdoc/kdoc_re.py | 202 -------------------------------
1 file changed, 202 deletions(-)

diff --git a/tools/lib/python/kdoc/kdoc_re.py b/tools/lib/python/kdoc/kdoc_re.py
index ba601a4f5035..6f3ae28859ea 100644
--- a/tools/lib/python/kdoc/kdoc_re.py
+++ b/tools/lib/python/kdoc/kdoc_re.py
@@ -140,205 +140,3 @@ class KernRe:
"""

return self.last_match.groups()
-
-
-#: Nested delimited pairs (brackets and parenthesis)
-DELIMITER_PAIRS = {
- '{': '}',
- '(': ')',
- '[': ']',
-}
-
-#: compiled delimiters
-RE_DELIM = KernRe(r'[\{\}\[\]\(\)]')
-
-
-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 parentheses 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: make NestedMatch handle multiple match groups
- #
- # 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-aligned.
- #
- # The content inside parentheses is converted into a single replace
- # group (e.g. r`\0').
- #
- # 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)
-
- def __init__(self, regex):
- self.regex = KernRe(regex)
-
- def _search(self, 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 places them
- into a stack, yielding a start/stop position of each match when the
- stack is zeroed.
-
- The algorithm should work fine for properly paired lines, but will
- silently ignore end delimiters that precede a start delimiter.
- This should be OK for kernel-doc parser, as unaligned delimiters
- would cause compilation errors. So, we don't need to raise exceptions
- to cover such issues.
- """
-
- stack = []
-
- for match_re in self.regex.finditer(line):
- start = match_re.start()
- offset = match_re.end()
- string_char = None
- escape = False
-
- d = line[offset - 1]
- if d not in DELIMITER_PAIRS:
- continue
-
- end = DELIMITER_PAIRS[d]
- stack.append(end)
-
- for match in RE_DELIM.finditer(line[offset:]):
- pos = match.start() + offset
-
- d = line[pos]
-
- if escape:
- escape = False
- continue
-
- if string_char:
- if d == '\\':
- escape = True
- elif d == string_char:
- string_char = None
-
- continue
-
- if d in ('"', "'"):
- string_char = d
- continue
-
- if d in DELIMITER_PAIRS:
- end = DELIMITER_PAIRS[d]
-
- stack.append(end)
- continue
-
- # Does the end delimiter match what is expected?
- if stack and d == stack[-1]:
- stack.pop()
-
- if not stack:
- yield start, offset, pos + 1
- break
-
- def search(self, 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(line):
-
- yield line[t[0]:t[2]]
-
- def sub(self, 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 the sub argument contains::
-
- r'\0'
-
- it will work 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(line):
- out += line[cur_pos:start]
-
- # Value, ignoring start/end delimiters
- value = line[end:pos - 1]
-
- # replaces \0 at the sub string, if \0 is used there
- new_sub = sub
- new_sub = new_sub.replace(r'\0', value)
-
- out += new_sub
-
- # Drop end ';' if any
- if pos < len(line) and 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
-
- def __repr__(self):
- """
- Returns a displayable version of the class init.
- """
-
- return f'NestedMatch("{self.regex.regex.pattern}")'
--
2.52.0