scripts: Import Python kerneldoc from Linux kernel

We last synced our copy of kerneldoc with Linux back in 2020.  In the
interim, upstream has entirely rewritten the script in Python, and
the new Python version is split into a main script plus some
libraries in the kernel's scripts/lib/kdoc.

Import all these files.  These are the versions as of kernel commit
0cc53520e68be, with no local changes.

We use the same lib/kdoc/ directory as the kernel does here, so we
can avoid having to edit the top-level script just to adjust a
pathname, even though it is probably not the naming we would have
picked if this was a purely QEMU script.

The Sphinx conf.py still points at the Perl version of the script,
so this Python code will not be invoked to build the docs yet.

NB: checkpatch complains about many things in this commit,
including the use of "GPL-2.0" rather than "GPL-2.0-only" in
the SPDX tags, but since this is a third party import we can
ignore this.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Message-id: 20250814171324.1614516-4-peter.maydell@linaro.org

1 files changed, 1669 insertions, 0 deletions

diff --git a/scripts/lib/kdoc/kdoc_parser.py b/scripts/lib/kdoc/kdoc_parser.py
new file mode 100644
index 0000000..fe73009
--- /dev/null
+++ b/scripts/lib/kdoc/kdoc_parser.py
@@ -0,0 +1,1669 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+# Copyright(c) 2025: Mauro Carvalho Chehab <mchehab@kernel.org>.
+#
+# pylint: disable=C0301,C0302,R0904,R0912,R0913,R0914,R0915,R0917,R1702
+
+"""
+kdoc_parser
+===========
+
+Read a C language source or header FILE and extract embedded
+documentation comments
+"""
+
+import sys
+import re
+from pprint import pformat
+
+from kdoc_re import NestedMatch, KernRe
+from kdoc_item import KdocItem
+
+#
+# Regular expressions used to parse kernel-doc markups at KernelDoc class.
+#
+# Let's declare them in lowercase outside any class to make easier to
+# convert from the python script.
+#
+# As those are evaluated at the beginning, no need to cache them
+#
+
+# Allow whitespace at end of comment start.
+doc_start = KernRe(r'^/\*\*\s*$', cache=False)
+
+doc_end = KernRe(r'\*/', cache=False)
+doc_com = KernRe(r'\s*\*\s*', cache=False)
+doc_com_body = KernRe(r'\s*\* ?', cache=False)
+doc_decl = doc_com + KernRe(r'(\w+)', cache=False)
+
+# @params and a strictly limited set of supported section names
+# Specifically:
+#   Match @word:
+#         @...:
+#         @{section-name}:
+# while trying to not match literal block starts like "example::"
+#
+known_section_names = 'description|context|returns?|notes?|examples?'
+known_sections = KernRe(known_section_names, flags = re.I)
+doc_sect = doc_com + \
+    KernRe(r'\s*(\@[.\w]+|\@\.\.\.|' + known_section_names + r')\s*:([^:].*)?$',
+           flags=re.I, cache=False)
+
+doc_content = doc_com_body + KernRe(r'(.*)', cache=False)
+doc_inline_start = KernRe(r'^\s*/\*\*\s*$', cache=False)
+doc_inline_sect = KernRe(r'\s*\*\s*(@\s*[\w][\w\.]*\s*):(.*)', cache=False)
+doc_inline_end = KernRe(r'^\s*\*/\s*$', cache=False)
+doc_inline_oneline = KernRe(r'^\s*/\*\*\s*(@[\w\s]+):\s*(.*)\s*\*/\s*$', cache=False)
+attribute = KernRe(r"__attribute__\s*\(\([a-z0-9,_\*\s\(\)]*\)\)",
+               flags=re.I | re.S, cache=False)
+
+export_symbol = KernRe(r'^\s*EXPORT_SYMBOL(_GPL)?\s*\(\s*(\w+)\s*\)\s*', cache=False)
+export_symbol_ns = KernRe(r'^\s*EXPORT_SYMBOL_NS(_GPL)?\s*\(\s*(\w+)\s*,\s*"\S+"\)\s*', cache=False)
+
+type_param = KernRe(r"\@(\w*((\.\w+)|(->\w+))*(\.\.\.)?)", cache=False)
+
+#
+# Tests for the beginning of a kerneldoc block in its various forms.
+#
+doc_block = doc_com + KernRe(r'DOC:\s*(.*)?', cache=False)
+doc_begin_data = KernRe(r"^\s*\*?\s*(struct|union|enum|typedef)\b\s*(\w*)", cache = False)
+doc_begin_func = KernRe(str(doc_com) +			# initial " * '
+                        r"(?:\w+\s*\*\s*)?" + 		# type (not captured)
+                        r'(?:define\s+)?' + 		# possible "define" (not captured)
+                        r'(\w+)\s*(?:\(\w*\))?\s*' +	# name and optional "(...)"
+                        r'(?:[-:].*)?$',		# description (not captured)
+                        cache = False)
+
+#
+# A little helper to get rid of excess white space
+#
+multi_space = KernRe(r'\s\s+')
+def trim_whitespace(s):
+    return multi_space.sub(' ', s.strip())
+
+class state:
+    """
+    State machine enums
+    """
+
+    # Parser states
+    NORMAL        = 0        # normal code
+    NAME          = 1        # looking for function name
+    DECLARATION   = 2        # We have seen a declaration which might not be done
+    BODY          = 3        # the body of the comment
+    SPECIAL_SECTION = 4      # doc section ending with a blank line
+    PROTO         = 5        # scanning prototype
+    DOCBLOCK      = 6        # documentation block
+    INLINE_NAME   = 7        # gathering doc outside main block
+    INLINE_TEXT   = 8	     # reading the body of inline docs
+
+    name = [
+        "NORMAL",
+        "NAME",
+        "DECLARATION",
+        "BODY",
+        "SPECIAL_SECTION",
+        "PROTO",
+        "DOCBLOCK",
+        "INLINE_NAME",
+        "INLINE_TEXT",
+    ]
+
+
+SECTION_DEFAULT = "Description"  # default section
+
+class KernelEntry:
+
+    def __init__(self, config, ln):
+        self.config = config
+
+        self._contents = []
+        self.prototype = ""
+
+        self.warnings = []
+
+        self.parameterlist = []
+        self.parameterdescs = {}
+        self.parametertypes = {}
+        self.parameterdesc_start_lines = {}
+
+        self.section_start_lines = {}
+        self.sections = {}
+
+        self.anon_struct_union = False
+
+        self.leading_space = None
+
+        # State flags
+        self.brcount = 0
+        self.declaration_start_line = ln + 1
+
+    #
+    # Management of section contents
+    #
+    def add_text(self, text):
+        self._contents.append(text)
+
+    def contents(self):
+        return '\n'.join(self._contents) + '\n'
+
+    # TODO: rename to emit_message after removal of kernel-doc.pl
+    def emit_msg(self, log_msg, warning=True):
+        """Emit a message"""
+
+        if not warning:
+            self.config.log.info(log_msg)
+            return
+
+        # Delegate warning output to output logic, as this way it
+        # will report warnings/info only for symbols that are output
+
+        self.warnings.append(log_msg)
+        return
+
+    #
+    # Begin a new section.
+    #
+    def begin_section(self, line_no, title = SECTION_DEFAULT, dump = False):
+        if dump:
+            self.dump_section(start_new = True)
+        self.section = title
+        self.new_start_line = line_no
+
+    def dump_section(self, start_new=True):
+        """
+        Dumps section contents to arrays/hashes intended for that purpose.
+        """
+        #
+        # If we have accumulated no contents in the default ("description")
+        # section, don't bother.
+        #
+        if self.section == SECTION_DEFAULT and not self._contents:
+            return
+        name = self.section
+        contents = self.contents()
+
+        if type_param.match(name):
+            name = type_param.group(1)
+
+            self.parameterdescs[name] = contents
+            self.parameterdesc_start_lines[name] = self.new_start_line
+
+            self.new_start_line = 0
+
+        else:
+            if name in self.sections and self.sections[name] != "":
+                # Only warn on user-specified duplicate section names
+                if name != SECTION_DEFAULT:
+                    self.emit_msg(self.new_start_line,
+                                  f"duplicate section name '{name}'\n")
+                # Treat as a new paragraph - add a blank line
+                self.sections[name] += '\n' + contents
+            else:
+                self.sections[name] = contents
+                self.section_start_lines[name] = self.new_start_line
+                self.new_start_line = 0
+
+#        self.config.log.debug("Section: %s : %s", name, pformat(vars(self)))
+
+        if start_new:
+            self.section = SECTION_DEFAULT
+            self._contents = []
+
+
+class KernelDoc:
+    """
+    Read a C language source or header FILE and extract embedded
+    documentation comments.
+    """
+
+    # Section names
+
+    section_context = "Context"
+    section_return = "Return"
+
+    undescribed = "-- undescribed --"
+
+    def __init__(self, config, fname):
+        """Initialize internal variables"""
+
+        self.fname = fname
+        self.config = config
+
+        # Initial state for the state machines
+        self.state = state.NORMAL
+
+        # Store entry currently being processed
+        self.entry = None
+
+        # Place all potential outputs into an array
+        self.entries = []
+
+        #
+        # We need Python 3.7 for its "dicts remember the insertion
+        # order" guarantee
+        #
+        if sys.version_info.major == 3 and sys.version_info.minor < 7:
+            self.emit_msg(0,
+                          'Python 3.7 or later is required for correct results')
+
+    def emit_msg(self, ln, msg, warning=True):
+        """Emit a message"""
+
+        log_msg = f"{self.fname}:{ln} {msg}"
+
+        if self.entry:
+            self.entry.emit_msg(log_msg, warning)
+            return
+
+        if warning:
+            self.config.log.warning(log_msg)
+        else:
+            self.config.log.info(log_msg)
+
+    def dump_section(self, start_new=True):
+        """
+        Dumps section contents to arrays/hashes intended for that purpose.
+        """
+
+        if self.entry:
+            self.entry.dump_section(start_new)
+
+    # TODO: rename it to store_declaration after removal of kernel-doc.pl
+    def output_declaration(self, dtype, name, **args):
+        """
+        Stores the entry into an entry array.
+
+        The actual output and output filters will be handled elsewhere
+        """
+
+        item = KdocItem(name, dtype, self.entry.declaration_start_line, **args)
+        item.warnings = self.entry.warnings
+
+        # Drop empty sections
+        # TODO: improve empty sections logic to emit warnings
+        sections = self.entry.sections
+        for section in ["Description", "Return"]:
+            if section in sections and not sections[section].rstrip():
+                del sections[section]
+        item.set_sections(sections, self.entry.section_start_lines)
+        item.set_params(self.entry.parameterlist, self.entry.parameterdescs,
+                        self.entry.parametertypes,
+                        self.entry.parameterdesc_start_lines)
+        self.entries.append(item)
+
+        self.config.log.debug("Output: %s:%s = %s", dtype, name, pformat(args))
+
+    def reset_state(self, ln):
+        """
+        Ancillary routine to create a new entry. It initializes all
+        variables used by the state machine.
+        """
+
+        self.entry = KernelEntry(self.config, ln)
+
+        # State flags
+        self.state = state.NORMAL
+
+    def push_parameter(self, ln, decl_type, param, dtype,
+                       org_arg, declaration_name):
+        """
+        Store parameters and their descriptions at self.entry.
+        """
+
+        if self.entry.anon_struct_union and dtype == "" and param == "}":
+            return  # Ignore the ending }; from anonymous struct/union
+
+        self.entry.anon_struct_union = False
+
+        param = KernRe(r'[\[\)].*').sub('', param, count=1)
+
+        if dtype == "" and param.endswith("..."):
+            if KernRe(r'\w\.\.\.$').search(param):
+                # For named variable parameters of the form `x...`,
+                # remove the dots
+                param = param[:-3]
+            else:
+                # Handles unnamed variable parameters
+                param = "..."
+
+            if param not in self.entry.parameterdescs or \
+                not self.entry.parameterdescs[param]:
+
+                self.entry.parameterdescs[param] = "variable arguments"
+
+        elif dtype == "" and (not param or param == "void"):
+            param = "void"
+            self.entry.parameterdescs[param] = "no arguments"
+
+        elif dtype == "" and param in ["struct", "union"]:
+            # Handle unnamed (anonymous) union or struct
+            dtype = param
+            param = "{unnamed_" + param + "}"
+            self.entry.parameterdescs[param] = "anonymous\n"
+            self.entry.anon_struct_union = True
+
+        # Handle cache group enforcing variables: they do not need
+        # to be described in header files
+        elif "__cacheline_group" in param:
+            # Ignore __cacheline_group_begin and __cacheline_group_end
+            return
+
+        # Warn if parameter has no description
+        # (but ignore ones starting with # as these are not parameters
+        # but inline preprocessor statements)
+        if param not in self.entry.parameterdescs and not param.startswith("#"):
+            self.entry.parameterdescs[param] = self.undescribed
+
+            if "." not in param:
+                if decl_type == 'function':
+                    dname = f"{decl_type} parameter"
+                else:
+                    dname = f"{decl_type} member"
+
+                self.emit_msg(ln,
+                              f"{dname} '{param}' not described in '{declaration_name}'")
+
+        # Strip spaces from param so that it is one continuous string on
+        # parameterlist. This fixes a problem where check_sections()
+        # cannot find a parameter like "addr[6 + 2]" because it actually
+        # appears as "addr[6", "+", "2]" on the parameter list.
+        # However, it's better to maintain the param string unchanged for
+        # output, so just weaken the string compare in check_sections()
+        # to ignore "[blah" in a parameter string.
+
+        self.entry.parameterlist.append(param)
+        org_arg = KernRe(r'\s\s+').sub(' ', org_arg)
+        self.entry.parametertypes[param] = org_arg
+
+
+    def create_parameter_list(self, ln, decl_type, args,
+                              splitter, declaration_name):
+        """
+        Creates a list of parameters, storing them at self.entry.
+        """
+
+        # temporarily replace all commas inside function pointer definition
+        arg_expr = KernRe(r'(\([^\),]+),')
+        while arg_expr.search(args):
+            args = arg_expr.sub(r"\1#", args)
+
+        for arg in args.split(splitter):
+            # Strip comments
+            arg = KernRe(r'\/\*.*\*\/').sub('', arg)
+
+            # Ignore argument attributes
+            arg = KernRe(r'\sPOS0?\s').sub(' ', arg)
+
+            # Strip leading/trailing spaces
+            arg = arg.strip()
+            arg = KernRe(r'\s+').sub(' ', arg, count=1)
+
+            if arg.startswith('#'):
+                # Treat preprocessor directive as a typeless variable just to fill
+                # corresponding data structures "correctly". Catch it later in
+                # output_* subs.
+
+                # Treat preprocessor directive as a typeless variable
+                self.push_parameter(ln, decl_type, arg, "",
+                                    "", declaration_name)
+
+            elif KernRe(r'\(.+\)\s*\(').search(arg):
+                # Pointer-to-function
+
+                arg = arg.replace('#', ',')
+
+                r = KernRe(r'[^\(]+\(\*?\s*([\w\[\]\.]*)\s*\)')
+                if r.match(arg):
+                    param = r.group(1)
+                else:
+                    self.emit_msg(ln, f"Invalid param: {arg}")
+                    param = arg
+
+                dtype = KernRe(r'([^\(]+\(\*?)\s*' + re.escape(param)).sub(r'\1', arg)
+                self.push_parameter(ln, decl_type, param, dtype,
+                                    arg, declaration_name)
+
+            elif KernRe(r'\(.+\)\s*\[').search(arg):
+                # Array-of-pointers
+
+                arg = arg.replace('#', ',')
+                r = KernRe(r'[^\(]+\(\s*\*\s*([\w\[\]\.]*?)\s*(\s*\[\s*[\w]+\s*\]\s*)*\)')
+                if r.match(arg):
+                    param = r.group(1)
+                else:
+                    self.emit_msg(ln, f"Invalid param: {arg}")
+                    param = arg
+
+                dtype = KernRe(r'([^\(]+\(\*?)\s*' + re.escape(param)).sub(r'\1', arg)
+
+                self.push_parameter(ln, decl_type, param, dtype,
+                                    arg, declaration_name)
+
+            elif arg:
+                arg = KernRe(r'\s*:\s*').sub(":", arg)
+                arg = KernRe(r'\s*\[').sub('[', arg)
+
+                args = KernRe(r'\s*,\s*').split(arg)
+                if args[0] and '*' in args[0]:
+                    args[0] = re.sub(r'(\*+)\s*', r' \1', args[0])
+
+                first_arg = []
+                r = KernRe(r'^(.*\s+)(.*?\[.*\].*)$')
+                if args[0] and r.match(args[0]):
+                    args.pop(0)
+                    first_arg.extend(r.group(1))
+                    first_arg.append(r.group(2))
+                else:
+                    first_arg = KernRe(r'\s+').split(args.pop(0))
+
+                args.insert(0, first_arg.pop())
+                dtype = ' '.join(first_arg)
+
+                for param in args:
+                    if KernRe(r'^(\*+)\s*(.*)').match(param):
+                        r = KernRe(r'^(\*+)\s*(.*)')
+                        if not r.match(param):
+                            self.emit_msg(ln, f"Invalid param: {param}")
+                            continue
+
+                        param = r.group(1)
+
+                        self.push_parameter(ln, decl_type, r.group(2),
+                                            f"{dtype} {r.group(1)}",
+                                            arg, declaration_name)
+
+                    elif KernRe(r'(.*?):(\w+)').search(param):
+                        r = KernRe(r'(.*?):(\w+)')
+                        if not r.match(param):
+                            self.emit_msg(ln, f"Invalid param: {param}")
+                            continue
+
+                        if dtype != "":  # Skip unnamed bit-fields
+                            self.push_parameter(ln, decl_type, r.group(1),
+                                                f"{dtype}:{r.group(2)}",
+                                                arg, declaration_name)
+                    else:
+                        self.push_parameter(ln, decl_type, param, dtype,
+                                            arg, declaration_name)
+
+    def check_sections(self, ln, decl_name, decl_type):
+        """
+        Check for errors inside sections, emitting warnings if not found
+        parameters are described.
+        """
+        for section in self.entry.sections:
+            if section not in self.entry.parameterlist and \
+               not known_sections.search(section):
+                if decl_type == 'function':
+                    dname = f"{decl_type} parameter"
+                else:
+                    dname = f"{decl_type} member"
+                self.emit_msg(ln,
+                              f"Excess {dname} '{section}' description in '{decl_name}'")
+
+    def check_return_section(self, ln, declaration_name, return_type):
+        """
+        If the function doesn't return void, warns about the lack of a
+        return description.
+        """
+
+        if not self.config.wreturn:
+            return
+
+        # Ignore an empty return type (It's a macro)
+        # Ignore functions with a "void" return type (but not "void *")
+        if not return_type or KernRe(r'void\s*\w*\s*$').search(return_type):
+            return
+
+        if not self.entry.sections.get("Return", None):
+            self.emit_msg(ln,
+                          f"No description found for return value of '{declaration_name}'")
+
+    def dump_struct(self, ln, proto):
+        """
+        Store an entry for an struct or union
+        """
+
+        type_pattern = r'(struct|union)'
+
+        qualifiers = [
+            "__attribute__",
+            "__packed",
+            "__aligned",
+            "____cacheline_aligned_in_smp",
+            "____cacheline_aligned",
+        ]
+
+        definition_body = r'\{(.*)\}\s*' + "(?:" + '|'.join(qualifiers) + ")?"
+        struct_members = KernRe(type_pattern + r'([^\{\};]+)(\{)([^\{\}]*)(\})([^\{\}\;]*)(\;)')
+
+        # Extract struct/union definition
+        members = None
+        declaration_name = None
+        decl_type = None
+
+        r = KernRe(type_pattern + r'\s+(\w+)\s*' + definition_body)
+        if r.search(proto):
+            decl_type = r.group(1)
+            declaration_name = r.group(2)
+            members = r.group(3)
+        else:
+            r = KernRe(r'typedef\s+' + type_pattern + r'\s*' + definition_body + r'\s*(\w+)\s*;')
+
+            if r.search(proto):
+                decl_type = r.group(1)
+                declaration_name = r.group(3)
+                members = r.group(2)
+
+        if not members:
+            self.emit_msg(ln, f"{proto} error: Cannot parse struct or union!")
+            return
+
+        if self.entry.identifier != declaration_name:
+            self.emit_msg(ln,
+                          f"expecting prototype for {decl_type} {self.entry.identifier}. Prototype was for {decl_type} {declaration_name} instead\n")
+            return
+
+        args_pattern = r'([^,)]+)'
+
+        sub_prefixes = [
+            (KernRe(r'\/\*\s*private:.*?\/\*\s*public:.*?\*\/', re.S | re.I), ''),
+            (KernRe(r'\/\*\s*private:.*', re.S | re.I), ''),
+
+            # Strip comments
+            (KernRe(r'\/\*.*?\*\/', re.S), ''),
+
+            # Strip attributes
+            (attribute, ' '),
+            (KernRe(r'\s*__aligned\s*\([^;]*\)', re.S), ' '),
+            (KernRe(r'\s*__counted_by\s*\([^;]*\)', re.S), ' '),
+            (KernRe(r'\s*__counted_by_(le|be)\s*\([^;]*\)', re.S), ' '),
+            (KernRe(r'\s*__packed\s*', re.S), ' '),
+            (KernRe(r'\s*CRYPTO_MINALIGN_ATTR', re.S), ' '),
+            (KernRe(r'\s*____cacheline_aligned_in_smp', re.S), ' '),
+            (KernRe(r'\s*____cacheline_aligned', re.S), ' '),
+
+            # Unwrap struct_group macros based on this definition:
+            # __struct_group(TAG, NAME, ATTRS, MEMBERS...)
+            # which has variants like: struct_group(NAME, MEMBERS...)
+            # Only MEMBERS arguments require documentation.
+            #
+            # Parsing them happens on two steps:
+            #
+            # 1. drop struct group arguments that aren't at MEMBERS,
+            #    storing them as STRUCT_GROUP(MEMBERS)
+            #
+            # 2. remove STRUCT_GROUP() ancillary macro.
+            #
+            # The original logic used to remove STRUCT_GROUP() using an
+            # advanced regex:
+            #
+            #   \bSTRUCT_GROUP(\(((?:(?>[^)(]+)|(?1))*)\))[^;]*;
+            #
+            # with two patterns that are incompatible with
+            # Python re module, as it has:
+            #
+            #   - a recursive pattern: (?1)
+            #   - an atomic grouping: (?>...)
+            #
+            # I tried a simpler version: but it didn't work either:
+            #   \bSTRUCT_GROUP\(([^\)]+)\)[^;]*;
+            #
+            # As it doesn't properly match the end parenthesis on some cases.
+            #
+            # So, a better solution was crafted: there's now a NestedMatch
+            # class that ensures that delimiters after a search are properly
+            # matched. So, the implementation to drop STRUCT_GROUP() will be
+            # handled in separate.
+
+            (KernRe(r'\bstruct_group\s*\(([^,]*,)', re.S), r'STRUCT_GROUP('),
+            (KernRe(r'\bstruct_group_attr\s*\(([^,]*,){2}', re.S), r'STRUCT_GROUP('),
+            (KernRe(r'\bstruct_group_tagged\s*\(([^,]*),([^,]*),', re.S), r'struct \1 \2; STRUCT_GROUP('),
+            (KernRe(r'\b__struct_group\s*\(([^,]*,){3}', re.S), r'STRUCT_GROUP('),
+
+            # Replace macros
+            #
+            # TODO: use NestedMatch for FOO($1, $2, ...) matches
+            #
+            # it is better to also move those to the NestedMatch logic,
+            # to ensure that parenthesis will be properly matched.
+
+            (KernRe(r'__ETHTOOL_DECLARE_LINK_MODE_MASK\s*\(([^\)]+)\)', re.S), r'DECLARE_BITMAP(\1, __ETHTOOL_LINK_MODE_MASK_NBITS)'),
+            (KernRe(r'DECLARE_PHY_INTERFACE_MASK\s*\(([^\)]+)\)', re.S), r'DECLARE_BITMAP(\1, PHY_INTERFACE_MODE_MAX)'),
+            (KernRe(r'DECLARE_BITMAP\s*\(' + args_pattern + r',\s*' + args_pattern + r'\)', re.S), r'unsigned long \1[BITS_TO_LONGS(\2)]'),
+            (KernRe(r'DECLARE_HASHTABLE\s*\(' + args_pattern + r',\s*' + args_pattern + r'\)', re.S), r'unsigned long \1[1 << ((\2) - 1)]'),
+            (KernRe(r'DECLARE_KFIFO\s*\(' + args_pattern + r',\s*' + args_pattern + r',\s*' + args_pattern + r'\)', re.S), r'\2 *\1'),
+            (KernRe(r'DECLARE_KFIFO_PTR\s*\(' + args_pattern + r',\s*' + args_pattern + r'\)', re.S), r'\2 *\1'),
+            (KernRe(r'(?:__)?DECLARE_FLEX_ARRAY\s*\(' + args_pattern + r',\s*' + args_pattern + r'\)', re.S), r'\1 \2[]'),
+            (KernRe(r'DEFINE_DMA_UNMAP_ADDR\s*\(' + args_pattern + r'\)', re.S), r'dma_addr_t \1'),
+            (KernRe(r'DEFINE_DMA_UNMAP_LEN\s*\(' + args_pattern + r'\)', re.S), r'__u32 \1'),
+            (KernRe(r'VIRTIO_DECLARE_FEATURES\s*\(' + args_pattern + r'\)', re.S), r'u64 \1; u64 \1_array[VIRTIO_FEATURES_DWORDS]'),
+        ]
+
+        # Regexes here are guaranteed to have the end limiter matching
+        # the start delimiter. Yet, right now, only one replace group
+        # is allowed.
+
+        sub_nested_prefixes = [
+            (re.compile(r'\bSTRUCT_GROUP\('), r'\1'),
+        ]
+
+        for search, sub in sub_prefixes:
+            members = search.sub(sub, members)
+
+        nested = NestedMatch()
+
+        for search, sub in sub_nested_prefixes:
+            members = nested.sub(search, sub, members)
+
+        # Keeps the original declaration as-is
+        declaration = members
+
+        # Split nested struct/union elements
+        #
+        # This loop was simpler at the original kernel-doc perl version, as
+        #   while ($members =~ m/$struct_members/) { ... }
+        # reads 'members' string on each interaction.
+        #
+        # Python behavior is different: it parses 'members' only once,
+        # creating a list of tuples from the first interaction.
+        #
+        # On other words, this won't get nested structs.
+        #
+        # So, we need to have an extra loop on Python to override such
+        # re limitation.
+
+        while True:
+            tuples = struct_members.findall(members)
+            if not tuples:
+                break
+
+            for t in tuples:
+                newmember = ""
+                maintype = t[0]
+                s_ids = t[5]
+                content = t[3]
+
+                oldmember = "".join(t)
+
+                for s_id in s_ids.split(','):
+                    s_id = s_id.strip()
+
+                    newmember += f"{maintype} {s_id}; "
+                    s_id = KernRe(r'[:\[].*').sub('', s_id)
+                    s_id = KernRe(r'^\s*\**(\S+)\s*').sub(r'\1', s_id)
+
+                    for arg in content.split(';'):
+                        arg = arg.strip()
+
+                        if not arg:
+                            continue
+
+                        r = KernRe(r'^([^\(]+\(\*?\s*)([\w\.]*)(\s*\).*)')
+                        if r.match(arg):
+                            # Pointer-to-function
+                            dtype = r.group(1)
+                            name = r.group(2)
+                            extra = r.group(3)
+
+                            if not name:
+                                continue
+
+                            if not s_id:
+                                # Anonymous struct/union
+                                newmember += f"{dtype}{name}{extra}; "
+                            else:
+                                newmember += f"{dtype}{s_id}.{name}{extra}; "
+
+                        else:
+                            arg = arg.strip()
+                            # Handle bitmaps
+                            arg = KernRe(r':\s*\d+\s*').sub('', arg)
+
+                            # Handle arrays
+                            arg = KernRe(r'\[.*\]').sub('', arg)
+
+                            # Handle multiple IDs
+                            arg = KernRe(r'\s*,\s*').sub(',', arg)
+
+                            r = KernRe(r'(.*)\s+([\S+,]+)')
+
+                            if r.search(arg):
+                                dtype = r.group(1)
+                                names = r.group(2)
+                            else:
+                                newmember += f"{arg}; "
+                                continue
+
+                            for name in names.split(','):
+                                name = KernRe(r'^\s*\**(\S+)\s*').sub(r'\1', name).strip()
+
+                                if not name:
+                                    continue
+
+                                if not s_id:
+                                    # Anonymous struct/union
+                                    newmember += f"{dtype} {name}; "
+                                else:
+                                    newmember += f"{dtype} {s_id}.{name}; "
+
+                members = members.replace(oldmember, newmember)
+
+        # Ignore other nested elements, like enums
+        members = re.sub(r'(\{[^\{\}]*\})', '', members)
+
+        self.create_parameter_list(ln, decl_type, members, ';',
+                                   declaration_name)
+        self.check_sections(ln, declaration_name, decl_type)
+
+        # Adjust declaration for better display
+        declaration = KernRe(r'([\{;])').sub(r'\1\n', declaration)
+        declaration = KernRe(r'\}\s+;').sub('};', declaration)
+
+        # Better handle inlined enums
+        while True:
+            r = KernRe(r'(enum\s+\{[^\}]+),([^\n])')
+            if not r.search(declaration):
+                break
+
+            declaration = r.sub(r'\1,\n\2', declaration)
+
+        def_args = declaration.split('\n')
+        level = 1
+        declaration = ""
+        for clause in def_args:
+
+            clause = clause.strip()
+            clause = KernRe(r'\s+').sub(' ', clause, count=1)
+
+            if not clause:
+                continue
+
+            if '}' in clause and level > 1:
+                level -= 1
+
+            if not KernRe(r'^\s*#').match(clause):
+                declaration += "\t" * level
+
+            declaration += "\t" + clause + "\n"
+            if "{" in clause and "}" not in clause:
+                level += 1
+
+        self.output_declaration(decl_type, declaration_name,
+                                definition=declaration,
+                                purpose=self.entry.declaration_purpose)
+
+    def dump_enum(self, ln, proto):
+        """
+        Stores an enum inside self.entries array.
+        """
+
+        # Ignore members marked private
+        proto = KernRe(r'\/\*\s*private:.*?\/\*\s*public:.*?\*\/', flags=re.S).sub('', proto)
+        proto = KernRe(r'\/\*\s*private:.*}', flags=re.S).sub('}', proto)
+
+        # Strip comments
+        proto = KernRe(r'\/\*.*?\*\/', flags=re.S).sub('', proto)
+
+        # Strip #define macros inside enums
+        proto = KernRe(r'#\s*((define|ifdef|if)\s+|endif)[^;]*;', flags=re.S).sub('', proto)
+
+        #
+        # Parse out the name and members of the enum.  Typedef form first.
+        #
+        r = KernRe(r'typedef\s+enum\s*\{(.*)\}\s*(\w*)\s*;')
+        if r.search(proto):
+            declaration_name = r.group(2)
+            members = r.group(1).rstrip()
+        #
+        # Failing that, look for a straight enum
+        #
+        else:
+            r = KernRe(r'enum\s+(\w*)\s*\{(.*)\}')
+            if r.match(proto):
+                declaration_name = r.group(1)
+                members = r.group(2).rstrip()
+        #
+        # OK, this isn't going to work.
+        #
+            else:
+                self.emit_msg(ln, f"{proto}: error: Cannot parse enum!")
+                return
+        #
+        # Make sure we found what we were expecting.
+        #
+        if self.entry.identifier != declaration_name:
+            if self.entry.identifier == "":
+                self.emit_msg(ln,
+                              f"{proto}: wrong kernel-doc identifier on prototype")
+            else:
+                self.emit_msg(ln,
+                              f"expecting prototype for enum {self.entry.identifier}. "
+                              f"Prototype was for enum {declaration_name} instead")
+            return
+
+        if not declaration_name:
+            declaration_name = "(anonymous)"
+        #
+        # Parse out the name of each enum member, and verify that we
+        # have a description for it.
+        #
+        member_set = set()
+        members = KernRe(r'\([^;)]*\)').sub('', members)
+        for arg in members.split(','):
+            if not arg:
+                continue
+            arg = KernRe(r'^\s*(\w+).*').sub(r'\1', arg)
+            self.entry.parameterlist.append(arg)
+            if arg not in self.entry.parameterdescs:
+                self.entry.parameterdescs[arg] = self.undescribed
+                self.emit_msg(ln,
+                              f"Enum value '{arg}' not described in enum '{declaration_name}'")
+            member_set.add(arg)
+        #
+        # Ensure that every described member actually exists in the enum.
+        #
+        for k in self.entry.parameterdescs:
+            if k not in member_set:
+                self.emit_msg(ln,
+                              f"Excess enum value '%{k}' description in '{declaration_name}'")
+
+        self.output_declaration('enum', declaration_name,
+                                purpose=self.entry.declaration_purpose)
+
+    def dump_declaration(self, ln, prototype):
+        """
+        Stores a data declaration inside self.entries array.
+        """
+
+        if self.entry.decl_type == "enum":
+            self.dump_enum(ln, prototype)
+        elif self.entry.decl_type == "typedef":
+            self.dump_typedef(ln, prototype)
+        elif self.entry.decl_type in ["union", "struct"]:
+            self.dump_struct(ln, prototype)
+        else:
+            # This would be a bug
+            self.emit_message(ln, f'Unknown declaration type: {self.entry.decl_type}')
+
+    def dump_function(self, ln, prototype):
+        """
+        Stores a function of function macro inside self.entries array.
+        """
+
+        func_macro = False
+        return_type = ''
+        decl_type = 'function'
+
+        # Prefixes that would be removed
+        sub_prefixes = [
+            (r"^static +", "", 0),
+            (r"^extern +", "", 0),
+            (r"^asmlinkage +", "", 0),
+            (r"^inline +", "", 0),
+            (r"^__inline__ +", "", 0),
+            (r"^__inline +", "", 0),
+            (r"^__always_inline +", "", 0),
+            (r"^noinline +", "", 0),
+            (r"^__FORTIFY_INLINE +", "", 0),
+            (r"__init +", "", 0),
+            (r"__init_or_module +", "", 0),
+            (r"__deprecated +", "", 0),
+            (r"__flatten +", "", 0),
+            (r"__meminit +", "", 0),
+            (r"__must_check +", "", 0),
+            (r"__weak +", "", 0),
+            (r"__sched +", "", 0),
+            (r"_noprof", "", 0),
+            (r"__printf\s*\(\s*\d*\s*,\s*\d*\s*\) +", "", 0),
+            (r"__(?:re)?alloc_size\s*\(\s*\d+\s*(?:,\s*\d+\s*)?\) +", "", 0),
+            (r"__diagnose_as\s*\(\s*\S+\s*(?:,\s*\d+\s*)*\) +", "", 0),
+            (r"DECL_BUCKET_PARAMS\s*\(\s*(\S+)\s*,\s*(\S+)\s*\)", r"\1, \2", 0),
+            (r"__attribute_const__ +", "", 0),
+
+            # It seems that Python support for re.X is broken:
+            # At least for me (Python 3.13), this didn't work
+#            (r"""
+#              __attribute__\s*\(\(
+#                (?:
+#                    [\w\s]+          # attribute name
+#                    (?:\([^)]*\))?   # attribute arguments
+#                    \s*,?            # optional comma at the end
+#                )+
+#              \)\)\s+
+#             """, "", re.X),
+
+            # So, remove whitespaces and comments from it
+            (r"__attribute__\s*\(\((?:[\w\s]+(?:\([^)]*\))?\s*,?)+\)\)\s+", "", 0),
+        ]
+
+        for search, sub, flags in sub_prefixes:
+            prototype = KernRe(search, flags).sub(sub, prototype)
+
+        # Macros are a special case, as they change the prototype format
+        new_proto = KernRe(r"^#\s*define\s+").sub("", prototype)
+        if new_proto != prototype:
+            is_define_proto = True
+            prototype = new_proto
+        else:
+            is_define_proto = False
+
+        # Yes, this truly is vile.  We are looking for:
+        # 1. Return type (may be nothing if we're looking at a macro)
+        # 2. Function name
+        # 3. Function parameters.
+        #
+        # All the while we have to watch out for function pointer parameters
+        # (which IIRC is what the two sections are for), C types (these
+        # regexps don't even start to express all the possibilities), and
+        # so on.
+        #
+        # If you mess with these regexps, it's a good idea to check that
+        # the following functions' documentation still comes out right:
+        # - parport_register_device (function pointer parameters)
+        # - atomic_set (macro)
+        # - pci_match_device, __copy_to_user (long return type)
+
+        name = r'[a-zA-Z0-9_~:]+'
+        prototype_end1 = r'[^\(]*'
+        prototype_end2 = r'[^\{]*'
+        prototype_end = fr'\(({prototype_end1}|{prototype_end2})\)'
+
+        # Besides compiling, Perl qr{[\w\s]+} works as a non-capturing group.
+        # So, this needs to be mapped in Python with (?:...)? or (?:...)+
+
+        type1 = r'(?:[\w\s]+)?'
+        type2 = r'(?:[\w\s]+\*+)+'
+
+        found = False
+
+        if is_define_proto:
+            r = KernRe(r'^()(' + name + r')\s+')
+
+            if r.search(prototype):
+                return_type = ''
+                declaration_name = r.group(2)
+                func_macro = True
+
+                found = True
+
+        if not found:
+            patterns = [
+                rf'^()({name})\s*{prototype_end}',
+                rf'^({type1})\s+({name})\s*{prototype_end}',
+                rf'^({type2})\s*({name})\s*{prototype_end}',
+            ]
+
+            for p in patterns:
+                r = KernRe(p)
+
+                if r.match(prototype):
+
+                    return_type = r.group(1)
+                    declaration_name = r.group(2)
+                    args = r.group(3)
+
+                    self.create_parameter_list(ln, decl_type, args, ',',
+                                               declaration_name)
+
+                    found = True
+                    break
+        if not found:
+            self.emit_msg(ln,
+                          f"cannot understand function prototype: '{prototype}'")
+            return
+
+        if self.entry.identifier != declaration_name:
+            self.emit_msg(ln,
+                          f"expecting prototype for {self.entry.identifier}(). Prototype was for {declaration_name}() instead")
+            return
+
+        self.check_sections(ln, declaration_name, "function")
+
+        self.check_return_section(ln, declaration_name, return_type)
+
+        if 'typedef' in return_type:
+            self.output_declaration(decl_type, declaration_name,
+                                    typedef=True,
+                                    functiontype=return_type,
+                                    purpose=self.entry.declaration_purpose,
+                                    func_macro=func_macro)
+        else:
+            self.output_declaration(decl_type, declaration_name,
+                                    typedef=False,
+                                    functiontype=return_type,
+                                    purpose=self.entry.declaration_purpose,
+                                    func_macro=func_macro)
+
+    def dump_typedef(self, ln, proto):
+        """
+        Stores a typedef inside self.entries array.
+        """
+
+        typedef_type = r'((?:\s+[\w\*]+\b){0,7}\s+(?:\w+\b|\*+))\s*'
+        typedef_ident = r'\*?\s*(\w\S+)\s*'
+        typedef_args = r'\s*\((.*)\);'
+
+        typedef1 = KernRe(r'typedef' + typedef_type + r'\(' + typedef_ident + r'\)' + typedef_args)
+        typedef2 = KernRe(r'typedef' + typedef_type + typedef_ident + typedef_args)
+
+        # Strip comments
+        proto = KernRe(r'/\*.*?\*/', flags=re.S).sub('', proto)
+
+        # Parse function typedef prototypes
+        for r in [typedef1, typedef2]:
+            if not r.match(proto):
+                continue
+
+            return_type = r.group(1).strip()
+            declaration_name = r.group(2)
+            args = r.group(3)
+
+            if self.entry.identifier != declaration_name:
+                self.emit_msg(ln,
+                              f"expecting prototype for typedef {self.entry.identifier}. Prototype was for typedef {declaration_name} instead\n")
+                return
+
+            decl_type = 'function'
+            self.create_parameter_list(ln, decl_type, args, ',', declaration_name)
+
+            self.output_declaration(decl_type, declaration_name,
+                                    typedef=True,
+                                    functiontype=return_type,
+                                    purpose=self.entry.declaration_purpose)
+            return
+
+        # Handle nested parentheses or brackets
+        r = KernRe(r'(\(*.\)\s*|\[*.\]\s*);$')
+        while r.search(proto):
+            proto = r.sub('', proto)
+
+        # Parse simple typedefs
+        r = KernRe(r'typedef.*\s+(\w+)\s*;')
+        if r.match(proto):
+            declaration_name = r.group(1)
+
+            if self.entry.identifier != declaration_name:
+                self.emit_msg(ln,
+                              f"expecting prototype for typedef {self.entry.identifier}. Prototype was for typedef {declaration_name} instead\n")
+                return
+
+            self.output_declaration('typedef', declaration_name,
+                                    purpose=self.entry.declaration_purpose)
+            return
+
+        self.emit_msg(ln, "error: Cannot parse typedef!")
+
+    @staticmethod
+    def process_export(function_set, line):
+        """
+        process EXPORT_SYMBOL* tags
+
+        This method doesn't use any variable from the class, so declare it
+        with a staticmethod decorator.
+        """
+
+        # We support documenting some exported symbols with different
+        # names.  A horrible hack.
+        suffixes = [ '_noprof' ]
+
+        # Note: it accepts only one EXPORT_SYMBOL* per line, as having
+        # multiple export lines would violate Kernel coding style.
+
+        if export_symbol.search(line):
+            symbol = export_symbol.group(2)
+        elif export_symbol_ns.search(line):
+            symbol = export_symbol_ns.group(2)
+        else:
+            return False
+        #
+        # Found an export, trim out any special suffixes
+        #
+        for suffix in suffixes:
+            # Be backward compatible with Python < 3.9
+            if symbol.endswith(suffix):
+                symbol = symbol[:-len(suffix)]
+        function_set.add(symbol)
+        return True
+
+    def process_normal(self, ln, line):
+        """
+        STATE_NORMAL: looking for the /** to begin everything.
+        """
+
+        if not doc_start.match(line):
+            return
+
+        # start a new entry
+        self.reset_state(ln)
+
+        # next line is always the function name
+        self.state = state.NAME
+
+    def process_name(self, ln, line):
+        """
+        STATE_NAME: Looking for the "name - description" line
+        """
+        #
+        # Check for a DOC: block and handle them specially.
+        #
+        if doc_block.search(line):
+
+            if not doc_block.group(1):
+                self.entry.begin_section(ln, "Introduction")
+            else:
+                self.entry.begin_section(ln, doc_block.group(1))
+
+            self.entry.identifier = self.entry.section
+            self.state = state.DOCBLOCK
+        #
+        # Otherwise we're looking for a normal kerneldoc declaration line.
+        #
+        elif doc_decl.search(line):
+            self.entry.identifier = doc_decl.group(1)
+
+            # Test for data declaration
+            if doc_begin_data.search(line):
+                self.entry.decl_type = doc_begin_data.group(1)
+                self.entry.identifier = doc_begin_data.group(2)
+            #
+            # Look for a function description
+            #
+            elif doc_begin_func.search(line):
+                self.entry.identifier = doc_begin_func.group(1)
+                self.entry.decl_type = "function"
+            #
+            # We struck out.
+            #
+            else:
+                self.emit_msg(ln,
+                              f"This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst\n{line}")
+                self.state = state.NORMAL
+                return
+            #
+            # OK, set up for a new kerneldoc entry.
+            #
+            self.state = state.BODY
+            self.entry.identifier = self.entry.identifier.strip(" ")
+            # if there's no @param blocks need to set up default section here
+            self.entry.begin_section(ln + 1)
+            #
+            # Find the description portion, which *should* be there but
+            # isn't always.
+            # (We should be able to capture this from the previous parsing - someday)
+            #
+            r = KernRe("[-:](.*)")
+            if r.search(line):
+                self.entry.declaration_purpose = trim_whitespace(r.group(1))
+                self.state = state.DECLARATION
+            else:
+                self.entry.declaration_purpose = ""
+
+            if not self.entry.declaration_purpose and self.config.wshort_desc:
+                self.emit_msg(ln,
+                              f"missing initial short description on line:\n{line}")
+
+            if not self.entry.identifier and self.entry.decl_type != "enum":
+                self.emit_msg(ln,
+                              f"wrong kernel-doc identifier on line:\n{line}")
+                self.state = state.NORMAL
+
+            if self.config.verbose:
+                self.emit_msg(ln,
+                              f"Scanning doc for {self.entry.decl_type} {self.entry.identifier}",
+                                  warning=False)
+        #
+        # Failed to find an identifier. Emit a warning
+        #
+        else:
+            self.emit_msg(ln, f"Cannot find identifier on line:\n{line}")
+
+    #
+    # Helper function to determine if a new section is being started.
+    #
+    def is_new_section(self, ln, line):
+        if doc_sect.search(line):
+            self.state = state.BODY
+            #
+            # Pick out the name of our new section, tweaking it if need be.
+            #
+            newsection = doc_sect.group(1)
+            if newsection.lower() == 'description':
+                newsection = 'Description'
+            elif newsection.lower() == 'context':
+                newsection = 'Context'
+                self.state = state.SPECIAL_SECTION
+            elif newsection.lower() in ["@return", "@returns",
+                                        "return", "returns"]:
+                newsection = "Return"
+                self.state = state.SPECIAL_SECTION
+            elif newsection[0] == '@':
+                self.state = state.SPECIAL_SECTION
+            #
+            # Initialize the contents, and get the new section going.
+            #
+            newcontents = doc_sect.group(2)
+            if not newcontents:
+                newcontents = ""
+            self.dump_section()
+            self.entry.begin_section(ln, newsection)
+            self.entry.leading_space = None
+
+            self.entry.add_text(newcontents.lstrip())
+            return True
+        return False
+
+    #
+    # Helper function to detect (and effect) the end of a kerneldoc comment.
+    #
+    def is_comment_end(self, ln, line):
+        if doc_end.search(line):
+            self.dump_section()
+
+            # Look for doc_com + <text> + doc_end:
+            r = KernRe(r'\s*\*\s*[a-zA-Z_0-9:\.]+\*/')
+            if r.match(line):
+                self.emit_msg(ln, f"suspicious ending line: {line}")
+
+            self.entry.prototype = ""
+            self.entry.new_start_line = ln + 1
+
+            self.state = state.PROTO
+            return True
+        return False
+
+
+    def process_decl(self, ln, line):
+        """
+        STATE_DECLARATION: We've seen the beginning of a declaration
+        """
+        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
+            return
+        #
+        # Look for anything with the " * " line beginning.
+        #
+        if doc_content.search(line):
+            cont = doc_content.group(1)
+            #
+            # A blank line means that we have moved out of the declaration
+            # part of the comment (without any "special section" parameter
+            # descriptions).
+            #
+            if cont == "":
+                self.state = state.BODY
+            #
+            # Otherwise we have more of the declaration section to soak up.
+            #
+            else:
+                self.entry.declaration_purpose = \
+                    trim_whitespace(self.entry.declaration_purpose + ' ' + cont)
+        else:
+            # Unknown line, ignore
+            self.emit_msg(ln, f"bad line: {line}")
+
+
+    def process_special(self, ln, line):
+        """
+        STATE_SPECIAL_SECTION: a section ending with a blank line
+        """
+        #
+        # If we have hit a blank line (only the " * " marker), then this
+        # section is done.
+        #
+        if KernRe(r"\s*\*\s*$").match(line):
+            self.entry.begin_section(ln, dump = True)
+            self.state = state.BODY
+            return
+        #
+        # Not a blank line, look for the other ways to end the section.
+        #
+        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
+            return
+        #
+        # OK, we should have a continuation of the text for this section.
+        #
+        if doc_content.search(line):
+            cont = doc_content.group(1)
+            #
+            # If the lines of text after the first in a special section have
+            # leading white space, we need to trim it out or Sphinx will get
+            # confused.  For the second line (the None case), see what we
+            # find there and remember it.
+            #
+            if self.entry.leading_space is None:
+                r = KernRe(r'^(\s+)')
+                if r.match(cont):
+                    self.entry.leading_space = len(r.group(1))
+                else:
+                    self.entry.leading_space = 0
+            #
+            # Otherwise, before trimming any leading chars, be *sure*
+            # that they are white space.  We should maybe warn if this
+            # isn't the case.
+            #
+            for i in range(0, self.entry.leading_space):
+                if cont[i] != " ":
+                    self.entry.leading_space = i
+                    break
+            #
+            # Add the trimmed result to the section and we're done.
+            #
+            self.entry.add_text(cont[self.entry.leading_space:])
+        else:
+            # Unknown line, ignore
+            self.emit_msg(ln, f"bad line: {line}")
+
+    def process_body(self, ln, line):
+        """
+        STATE_BODY: the bulk of a kerneldoc comment.
+        """
+        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
+            return
+
+        if doc_content.search(line):
+            cont = doc_content.group(1)
+            self.entry.add_text(cont)
+        else:
+            # Unknown line, ignore
+            self.emit_msg(ln, f"bad line: {line}")
+
+    def process_inline_name(self, ln, line):
+        """STATE_INLINE_NAME: beginning of docbook comments within a prototype."""
+
+        if doc_inline_sect.search(line):
+            self.entry.begin_section(ln, doc_inline_sect.group(1))
+            self.entry.add_text(doc_inline_sect.group(2).lstrip())
+            self.state = state.INLINE_TEXT
+        elif doc_inline_end.search(line):
+            self.dump_section()
+            self.state = state.PROTO
+        elif doc_content.search(line):
+            self.emit_msg(ln, f"Incorrect use of kernel-doc format: {line}")
+            self.state = state.PROTO
+        # else ... ??
+
+    def process_inline_text(self, ln, line):
+        """STATE_INLINE_TEXT: docbook comments within a prototype."""
+
+        if doc_inline_end.search(line):
+            self.dump_section()
+            self.state = state.PROTO
+        elif doc_content.search(line):
+            self.entry.add_text(doc_content.group(1))
+        # else ... ??
+
+    def syscall_munge(self, ln, proto):         # pylint: disable=W0613
+        """
+        Handle syscall definitions
+        """
+
+        is_void = False
+
+        # Strip newlines/CR's
+        proto = re.sub(r'[\r\n]+', ' ', proto)
+
+        # Check if it's a SYSCALL_DEFINE0
+        if 'SYSCALL_DEFINE0' in proto:
+            is_void = True
+
+        # Replace SYSCALL_DEFINE with correct return type & function name
+        proto = KernRe(r'SYSCALL_DEFINE.*\(').sub('long sys_', proto)
+
+        r = KernRe(r'long\s+(sys_.*?),')
+        if r.search(proto):
+            proto = KernRe(',').sub('(', proto, count=1)
+        elif is_void:
+            proto = KernRe(r'\)').sub('(void)', proto, count=1)
+
+        # Now delete all of the odd-numbered commas in the proto
+        # so that argument types & names don't have a comma between them
+        count = 0
+        length = len(proto)
+
+        if is_void:
+            length = 0  # skip the loop if is_void
+
+        for ix in range(length):
+            if proto[ix] == ',':
+                count += 1
+                if count % 2 == 1:
+                    proto = proto[:ix] + ' ' + proto[ix + 1:]
+
+        return proto
+
+    def tracepoint_munge(self, ln, proto):
+        """
+        Handle tracepoint definitions
+        """
+
+        tracepointname = None
+        tracepointargs = None
+
+        # Match tracepoint name based on different patterns
+        r = KernRe(r'TRACE_EVENT\((.*?),')
+        if r.search(proto):
+            tracepointname = r.group(1)
+
+        r = KernRe(r'DEFINE_SINGLE_EVENT\((.*?),')
+        if r.search(proto):
+            tracepointname = r.group(1)
+
+        r = KernRe(r'DEFINE_EVENT\((.*?),(.*?),')
+        if r.search(proto):
+            tracepointname = r.group(2)
+
+        if tracepointname:
+            tracepointname = tracepointname.lstrip()
+
+        r = KernRe(r'TP_PROTO\((.*?)\)')
+        if r.search(proto):
+            tracepointargs = r.group(1)
+
+        if not tracepointname or not tracepointargs:
+            self.emit_msg(ln,
+                          f"Unrecognized tracepoint format:\n{proto}\n")
+        else:
+            proto = f"static inline void trace_{tracepointname}({tracepointargs})"
+            self.entry.identifier = f"trace_{self.entry.identifier}"
+
+        return proto
+
+    def process_proto_function(self, ln, line):
+        """Ancillary routine to process a function prototype"""
+
+        # strip C99-style comments to end of line
+        line = KernRe(r"\/\/.*$", re.S).sub('', line)
+        #
+        # Soak up the line's worth of prototype text, stopping at { or ; if present.
+        #
+        if KernRe(r'\s*#\s*define').match(line):
+            self.entry.prototype = line
+        elif not line.startswith('#'):   # skip other preprocessor stuff
+            r = KernRe(r'([^\{]*)')
+            if r.match(line):
+                self.entry.prototype += r.group(1) + " "
+        #
+        # If we now have the whole prototype, clean it up and declare victory.
+        #
+        if '{' in line or ';' in line or KernRe(r'\s*#\s*define').match(line):
+            # strip comments and surrounding spaces
+            self.entry.prototype = KernRe(r'/\*.*\*/').sub('', self.entry.prototype).strip()
+            #
+            # Handle self.entry.prototypes for function pointers like:
+            #       int (*pcs_config)(struct foo)
+            # by turning it into
+            #	    int pcs_config(struct foo)
+            #
+            r = KernRe(r'^(\S+\s+)\(\s*\*(\S+)\)')
+            self.entry.prototype = r.sub(r'\1\2', self.entry.prototype)
+            #
+            # Handle special declaration syntaxes
+            #
+            if 'SYSCALL_DEFINE' in self.entry.prototype:
+                self.entry.prototype = self.syscall_munge(ln,
+                                                          self.entry.prototype)
+            else:
+                r = KernRe(r'TRACE_EVENT|DEFINE_EVENT|DEFINE_SINGLE_EVENT')
+                if r.search(self.entry.prototype):
+                    self.entry.prototype = self.tracepoint_munge(ln,
+                                                                 self.entry.prototype)
+            #
+            # ... and we're done
+            #
+            self.dump_function(ln, self.entry.prototype)
+            self.reset_state(ln)
+
+    def process_proto_type(self, ln, line):
+        """Ancillary routine to process a type"""
+
+        # Strip C99-style comments and surrounding whitespace
+        line = KernRe(r"//.*$", re.S).sub('', line).strip()
+        if not line:
+            return # nothing to see here
+
+        # To distinguish preprocessor directive from regular declaration later.
+        if line.startswith('#'):
+            line += ";"
+        #
+        # Split the declaration on any of { } or ;, and accumulate pieces
+        # until we hit a semicolon while not inside {brackets}
+        #
+        r = KernRe(r'(.*?)([{};])')
+        for chunk in r.split(line):
+            if chunk:  # Ignore empty matches
+                self.entry.prototype += chunk
+                #
+                # This cries out for a match statement ... someday after we can
+                # drop Python 3.9 ...
+                #
+                if chunk == '{':
+                    self.entry.brcount += 1
+                elif chunk == '}':
+                    self.entry.brcount -= 1
+                elif chunk == ';' and self.entry.brcount <= 0:
+                    self.dump_declaration(ln, self.entry.prototype)
+                    self.reset_state(ln)
+                    return
+        #
+        # We hit the end of the line while still in the declaration; put
+        # in a space to represent the newline.
+        #
+        self.entry.prototype += ' '
+
+    def process_proto(self, ln, line):
+        """STATE_PROTO: reading a function/whatever prototype."""
+
+        if doc_inline_oneline.search(line):
+            self.entry.begin_section(ln, doc_inline_oneline.group(1))
+            self.entry.add_text(doc_inline_oneline.group(2))
+            self.dump_section()
+
+        elif doc_inline_start.search(line):
+            self.state = state.INLINE_NAME
+
+        elif self.entry.decl_type == 'function':
+            self.process_proto_function(ln, line)
+
+        else:
+            self.process_proto_type(ln, line)
+
+    def process_docblock(self, ln, line):
+        """STATE_DOCBLOCK: within a DOC: block."""
+
+        if doc_end.search(line):
+            self.dump_section()
+            self.output_declaration("doc", self.entry.identifier)
+            self.reset_state(ln)
+
+        elif doc_content.search(line):
+            self.entry.add_text(doc_content.group(1))
+
+    def parse_export(self):
+        """
+        Parses EXPORT_SYMBOL* macros from a single Kernel source file.
+        """
+
+        export_table = set()
+
+        try:
+            with open(self.fname, "r", encoding="utf8",
+                      errors="backslashreplace") as fp:
+
+                for line in fp:
+                    self.process_export(export_table, line)
+
+        except IOError:
+            return None
+
+        return export_table
+
+    #
+    # The state/action table telling us which function to invoke in
+    # each state.
+    #
+    state_actions = {
+        state.NORMAL:			process_normal,
+        state.NAME:			process_name,
+        state.BODY:			process_body,
+        state.DECLARATION:		process_decl,
+        state.SPECIAL_SECTION:		process_special,
+        state.INLINE_NAME:		process_inline_name,
+        state.INLINE_TEXT:		process_inline_text,
+        state.PROTO:			process_proto,
+        state.DOCBLOCK:			process_docblock,
+        }
+
+    def parse_kdoc(self):
+        """
+        Open and process each line of a C source file.
+        The parsing is controlled via a state machine, and the line is passed
+        to a different process function depending on the state. The process
+        function may update the state as needed.
+
+        Besides parsing kernel-doc tags, it also parses export symbols.
+        """
+
+        prev = ""
+        prev_ln = None
+        export_table = set()
+
+        try:
+            with open(self.fname, "r", encoding="utf8",
+                      errors="backslashreplace") as fp:
+                for ln, line in enumerate(fp):
+
+                    line = line.expandtabs().strip("\n")
+
+                    # Group continuation lines on prototypes
+                    if self.state == state.PROTO:
+                        if line.endswith("\\"):
+                            prev += line.rstrip("\\")
+                            if not prev_ln:
+                                prev_ln = ln
+                            continue
+
+                        if prev:
+                            ln = prev_ln
+                            line = prev + line
+                            prev = ""
+                            prev_ln = None
+
+                    self.config.log.debug("%d %s: %s",
+                                          ln, state.name[self.state],
+                                          line)
+
+                    # This is an optimization over the original script.
+                    # There, when export_file was used for the same file,
+                    # it was read twice. Here, we use the already-existing
+                    # loop to parse exported symbols as well.
+                    #
+                    if (self.state != state.NORMAL) or \
+                       not self.process_export(export_table, line):
+                        # Hand this line to the appropriate state handler
+                        self.state_actions[self.state](self, ln, line)
+
+        except OSError:
+            self.config.log.error(f"Error: Cannot open file {self.fname}")
+
+        return export_table, self.entries