#!/usr/bin/env python3 # xxpylint: disable=R0903 # Copyright(c) 2025: Mauro Carvalho Chehab . # SPDX-License-Identifier: GPL-2.0 """ Convert ABI what into regular expressions """ import re import sys from pprint import pformat from abi_parser import AbiParser from helpers import AbiDebug class AbiRegex(AbiParser): """Extends AbiParser to search ABI nodes with regular expressions""" # Escape only ASCII visible characters escape_symbols = r"([\x21-\x29\x2b-\x2d\x3a-\x40\x5c\x60\x7b-\x7e])" leave_others = "others" # Tuples with regular expressions to be compiled and replacement data re_whats = [ # Drop escape characters that might exist (re.compile("\\\\"), ""), # Temporarily escape dot characters (re.compile(r"\."), "\xf6"), # Temporarily change [0-9]+ type of patterns (re.compile(r"\[0\-9\]\+"), "\xff"), # Temporarily change [\d+-\d+] type of patterns (re.compile(r"\[0\-\d+\]"), "\xff"), (re.compile(r"\[0:\d+\]"), "\xff"), (re.compile(r"\[(\d+)\]"), "\xf4\\\\d+\xf5"), # Temporarily change [0-9] type of patterns (re.compile(r"\[(\d)\-(\d)\]"), "\xf4\1-\2\xf5"), # Handle multiple option patterns (re.compile(r"[\{\<\[]([\w_]+)(?:[,|]+([\w_]+)){1,}[\}\>\]]"), r"(\1|\2)"), # Handle wildcards (re.compile(r"([^\/])\*"), "\\1\\\\w\xf7"), (re.compile(r"/\*/"), "/.*/"), (re.compile(r"/\xf6\xf6\xf6"), "/.*"), (re.compile(r"\<[^\>]+\>"), "\\\\w\xf7"), (re.compile(r"\{[^\}]+\}"), "\\\\w\xf7"), (re.compile(r"\[[^\]]+\]"), "\\\\w\xf7"), (re.compile(r"XX+"), "\\\\w\xf7"), (re.compile(r"([^A-Z])[XYZ]([^A-Z])"), "\\1\\\\w\xf7\\2"), (re.compile(r"([^A-Z])[XYZ]$"), "\\1\\\\w\xf7"), (re.compile(r"_[AB]_"), "_\\\\w\xf7_"), # Recover [0-9] type of patterns (re.compile(r"\xf4"), "["), (re.compile(r"\xf5"), "]"), # Remove duplicated spaces (re.compile(r"\s+"), r" "), # Special case: drop comparison as in: # What: foo = # (this happens on a few IIO definitions) (re.compile(r"\s*\=.*$"), ""), # Escape all other symbols (re.compile(escape_symbols), r"\\\1"), (re.compile(r"\\\\"), r"\\"), (re.compile(r"\\([\[\]\(\)\|])"), r"\1"), (re.compile(r"(\d+)\\(-\d+)"), r"\1\2"), (re.compile(r"\xff"), r"\\d+"), # Special case: IIO ABI which a parenthesis. (re.compile(r"sqrt(.*)"), r"sqrt(.*)"), # Simplify regexes with multiple .* (re.compile(r"(?:\.\*){2,}"), ""), # Recover dot characters (re.compile(r"\xf6"), "\\."), # Recover plus characters (re.compile(r"\xf7"), "+"), ] re_has_num = re.compile(r"\\d") # Symbol name after escape_chars that are considered a devnode basename re_symbol_name = re.compile(r"(\w|\\[\.\-\:])+$") # List of popular group names to be skipped to minimize regex group size # Use AbiDebug.SUBGROUP_SIZE to detect those skip_names = set(["devices", "hwmon"]) def regex_append(self, what, new): """ Get a search group for a subset of regular expressions. As ABI may have thousands of symbols, using a for to search all regular expressions is at least O(n^2). When there are wildcards, the complexity increases substantially, eventually becoming exponential. To avoid spending too much time on them, use a logic to split them into groups. The smaller the group, the better, as it would mean that searches will be confined to a small number of regular expressions. The conversion to a regex subset is tricky, as we need something that can be easily obtained from the sysfs symbol and from the regular expression. So, we need to discard nodes that have wildcards. If it can't obtain a subgroup, place the regular expression inside a special group (self.leave_others). """ search_group = None for search_group in reversed(new.split("/")): if not search_group or search_group in self.skip_names: continue if self.re_symbol_name.match(search_group): break if not search_group: search_group = self.leave_others if self.debug & AbiDebug.SUBGROUP_MAP: self.log.debug("%s: mapped as %s", what, search_group) try: if search_group not in self.regex_group: self.regex_group[search_group] = [] self.regex_group[search_group].append(re.compile(new)) if self.search_string: if what.find(self.search_string) >= 0: print(f"What: {what}") except re.PatternError: self.log.warning("Ignoring '%s' as it produced an invalid regex:\n" " '%s'", what, new) def get_regexes(self, what): """ Given an ABI devnode, return a list of all regular expressions that may match it, based on the sub-groups created by regex_append() """ re_list = [] patches = what.split("/") patches.reverse() patches.append(self.leave_others) for search_group in patches: if search_group in self.regex_group: re_list += self.regex_group[search_group] return re_list def __init__(self, *args, **kwargs): """ Override init method to get verbose argument """ self.regex_group = None self.search_string = None self.re_string = None if "search_string" in kwargs: self.search_string = kwargs.get("search_string") del kwargs["search_string"] if self.search_string: try: self.re_string = re.compile(self.search_string) except re.PatternError as e: msg = f"{self.search_string} is not a valid regular expression" raise ValueError(msg) from e super().__init__(*args, **kwargs) def parse_abi(self, *args, **kwargs): super().parse_abi(*args, **kwargs) self.regex_group = {} print("Converting ABI What fields into regexes...", file=sys.stderr) for t in sorted(self.data.items(), key=lambda x: x[0]): v = t[1] if v.get("type") == "File": continue v["regex"] = [] for what in v.get("what", []): if not what.startswith("/sys"): continue new = what for r, s in self.re_whats: try: new = r.sub(s, new) except re.PatternError as e: # Help debugging troubles with new regexes raise re.PatternError(f"{e}\nwhile re.sub('{r.pattern}', {s}, str)") from e v["regex"].append(new) if self.debug & AbiDebug.REGEX: self.log.debug("%-90s <== %s", new, what) # Store regex into a subgroup to speedup searches self.regex_append(what, new) if self.debug & AbiDebug.SUBGROUP_DICT: self.log.debug("%s", pformat(self.regex_group)) if self.debug & AbiDebug.SUBGROUP_SIZE: biggestd_keys = sorted(self.regex_group.keys(), key= lambda k: len(self.regex_group[k]), reverse=True) print("Top regex subgroups:", file=sys.stderr) for k in biggestd_keys[:10]: print(f"{k} has {len(self.regex_group[k])} elements", file=sys.stderr)