#!/usr/bin/env python3# xxpylint: disable=R0903# Copyright(c) 2025: Mauro Carvalho Chehab <mchehab@kernel.org>.# SPDX-License-Identifier: GPL-2.0 """Convert ABI what into regular expressions""" import reimport sys from pprint import pformat from abi.abi_parser import AbiParserfrom abi.helpers import AbiDebug class AbiRegex(AbiParser):    """    Extends AbiParser to search ABI nodes with regular expressions.     There some optimizations here to allow a quick symbol search:    instead of trying to place all symbols altogether an doing linear    search which is very time consuming, create a tree with one depth,    grouping similar symbols altogether.     Yet, sometimes a full search will be needed, so we have a special branch    on such group tree where other symbols are placed.    """     #: Escape only ASCII visible characters.    escape_symbols = r"([\x21-\x29\x2b-\x2d\x3a-\x40\x5c\x60\x7b-\x7e])"     #: Special group for other nodes.    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])"), "\\\\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 = <something>        # (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"), "+"),    ]     #: Regex to check if the symbol name has a number on it.    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.error:            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.error 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.error as e:                        # Help debugging troubles with new regexes                        raise re.error(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)