xref: /linux/tools/lib/python/kdoc/kdoc_parser.py (revision c991b7ef2fb658c186df56d16b3ebcd0afb555cc)
1#!/usr/bin/env python3
2# SPDX-License-Identifier: GPL-2.0
3# Copyright(c) 2025: Mauro Carvalho Chehab <mchehab@kernel.org>.
4#
5# pylint: disable=C0301,C0302,R0904,R0912,R0913,R0914,R0915,R0917,R1702
6
7"""
8Classes and functions related to reading a C language source or header FILE
9and extract embedded documentation comments from it.
10"""
11
12import sys
13import re
14from pprint import pformat
15
16from kdoc.kdoc_re import NestedMatch, KernRe
17from kdoc.kdoc_item import KdocItem
18
19#
20# Regular expressions used to parse kernel-doc markups at KernelDoc class.
21#
22# Let's declare them in lowercase outside any class to make it easier to
23# convert from the Perl script.
24#
25# As those are evaluated at the beginning, no need to cache them
26#
27
28# Allow whitespace at end of comment start.
29doc_start = KernRe(r'^/\*\*\s*$', cache=False)
30
31doc_end = KernRe(r'\*/', cache=False)
32doc_com = KernRe(r'\s*\*\s*', cache=False)
33doc_com_body = KernRe(r'\s*\* ?', cache=False)
34doc_decl = doc_com + KernRe(r'(\w+)', cache=False)
35
36# @params and a strictly limited set of supported section names
37# Specifically:
38#   Match @word:
39#         @...:
40#         @{section-name}:
41# while trying to not match literal block starts like "example::"
42#
43known_section_names = 'description|context|returns?|notes?|examples?'
44known_sections = KernRe(known_section_names, flags = re.I)
45doc_sect = doc_com + \
46    KernRe(r'\s*(@[.\w]+|@\.\.\.|' + known_section_names + r')\s*:([^:].*)?$',
47           flags=re.I, cache=False)
48
49doc_content = doc_com_body + KernRe(r'(.*)', cache=False)
50doc_inline_start = KernRe(r'^\s*/\*\*\s*$', cache=False)
51doc_inline_sect = KernRe(r'\s*\*\s*(@\s*[\w][\w\.]*\s*):(.*)', cache=False)
52doc_inline_end = KernRe(r'^\s*\*/\s*$', cache=False)
53doc_inline_oneline = KernRe(r'^\s*/\*\*\s*(@\s*[\w][\w\.]*\s*):\s*(.*)\s*\*/\s*$', cache=False)
54
55export_symbol = KernRe(r'^\s*EXPORT_SYMBOL(_GPL)?\s*\(\s*(\w+)\s*\)\s*', cache=False)
56export_symbol_ns = KernRe(r'^\s*EXPORT_SYMBOL_NS(_GPL)?\s*\(\s*(\w+)\s*,\s*"\S+"\)\s*', cache=False)
57
58type_param = KernRe(r"@(\w*((\.\w+)|(->\w+))*(\.\.\.)?)", cache=False)
59
60#
61# Tests for the beginning of a kerneldoc block in its various forms.
62#
63doc_block = doc_com + KernRe(r'DOC:\s*(.*)?', cache=False)
64doc_begin_data = KernRe(r"^\s*\*?\s*(struct|union|enum|typedef|var)\b\s*(\w*)", cache = False)
65doc_begin_func = KernRe(str(doc_com) +			# initial " * '
66                        r"(?:\w+\s*\*\s*)?" + 		# type (not captured)
67                        r'(?:define\s+)?' + 		# possible "define" (not captured)
68                        r'(\w+)\s*(?:\(\w*\))?\s*' +	# name and optional "(...)"
69                        r'(?:[-:].*)?$',		# description (not captured)
70                        cache = False)
71
72#
73# Ancillary functions
74#
75
76multi_space = KernRe(r'\s\s+')
77def trim_whitespace(s):
78    """
79    A little helper to get rid of excess white space.
80    """
81    return multi_space.sub(' ', s.strip())
82
83def trim_private_members(text):
84    """
85    Remove ``struct``/``enum`` members that have been marked "private".
86    """
87    # First look for a "public:" block that ends a private region, then
88    # handle the "private until the end" case.
89    #
90    text = KernRe(r'/\*\s*private:.*?/\*\s*public:.*?\*/', flags=re.S).sub('', text)
91    text = KernRe(r'/\*\s*private:.*', flags=re.S).sub('', text)
92    #
93    # We needed the comments to do the above, but now we can take them out.
94    #
95    return KernRe(r'\s*/\*.*?\*/\s*', flags=re.S).sub('', text).strip()
96
97class state:
98    """
99    States used by the parser's state machine.
100    """
101
102    # Parser states
103    NORMAL        = 0        #: Normal code.
104    NAME          = 1        #: Looking for function name.
105    DECLARATION   = 2        #: We have seen a declaration which might not be done.
106    BODY          = 3        #: The body of the comment.
107    SPECIAL_SECTION = 4      #: Doc section ending with a blank line.
108    PROTO         = 5        #: Scanning prototype.
109    DOCBLOCK      = 6        #: Documentation block.
110    INLINE_NAME   = 7        #: Gathering doc outside main block.
111    INLINE_TEXT   = 8	     #: Reading the body of inline docs.
112
113    #: Names for each parser state.
114    name = [
115        "NORMAL",
116        "NAME",
117        "DECLARATION",
118        "BODY",
119        "SPECIAL_SECTION",
120        "PROTO",
121        "DOCBLOCK",
122        "INLINE_NAME",
123        "INLINE_TEXT",
124    ]
125
126
127SECTION_DEFAULT = "Description"  #: Default section.
128
129class KernelEntry:
130    """
131    Encapsulates a Kernel documentation entry.
132    """
133
134    def __init__(self, config, fname, ln):
135        self.config = config
136        self.fname = fname
137
138        self._contents = []
139        self.prototype = ""
140
141        self.warnings = []
142
143        self.parameterlist = []
144        self.parameterdescs = {}
145        self.parametertypes = {}
146        self.parameterdesc_start_lines = {}
147
148        self.section_start_lines = {}
149        self.sections = {}
150
151        self.anon_struct_union = False
152
153        self.leading_space = None
154
155        self.fname = fname
156
157        # State flags
158        self.brcount = 0
159        self.declaration_start_line = ln + 1
160
161    #
162    # Management of section contents
163    #
164    def add_text(self, text):
165        """Add a new text to the entry contents list."""
166        self._contents.append(text)
167
168    def contents(self):
169        """Returns a string with all content texts that were added."""
170        return '\n'.join(self._contents) + '\n'
171
172    # TODO: rename to emit_message after removal of kernel-doc.pl
173    def emit_msg(self, ln, msg, *, warning=True):
174        """Emit a message."""
175
176        log_msg = f"{self.fname}:{ln} {msg}"
177
178        if not warning:
179            self.config.log.info(log_msg)
180            return
181
182        # Delegate warning output to output logic, as this way it
183        # will report warnings/info only for symbols that are output
184
185        self.warnings.append(log_msg)
186        return
187
188    def begin_section(self, line_no, title = SECTION_DEFAULT, dump = False):
189        """
190        Begin a new section.
191        """
192        if dump:
193            self.dump_section(start_new = True)
194        self.section = title
195        self.new_start_line = line_no
196
197    def dump_section(self, start_new=True):
198        """
199        Dumps section contents to arrays/hashes intended for that purpose.
200        """
201        #
202        # If we have accumulated no contents in the default ("description")
203        # section, don't bother.
204        #
205        if self.section == SECTION_DEFAULT and not self._contents:
206            return
207        name = self.section
208        contents = self.contents()
209
210        if type_param.match(name):
211            name = type_param.group(1)
212
213            self.parameterdescs[name] = contents
214            self.parameterdesc_start_lines[name] = self.new_start_line
215
216            self.new_start_line = 0
217
218        else:
219            if name in self.sections and self.sections[name] != "":
220                # Only warn on user-specified duplicate section names
221                if name != SECTION_DEFAULT:
222                    self.emit_msg(self.new_start_line,
223                                  f"duplicate section name '{name}'")
224                # Treat as a new paragraph - add a blank line
225                self.sections[name] += '\n' + contents
226            else:
227                self.sections[name] = contents
228                self.section_start_lines[name] = self.new_start_line
229                self.new_start_line = 0
230
231#        self.config.log.debug("Section: %s : %s", name, pformat(vars(self)))
232
233        if start_new:
234            self.section = SECTION_DEFAULT
235            self._contents = []
236
237python_warning = False
238
239class KernelDoc:
240    """
241    Read a C language source or header FILE and extract embedded
242    documentation comments.
243    """
244
245    #: Name of context section.
246    section_context = "Context"
247
248    #: Name of return section.
249    section_return = "Return"
250
251    #: String to write when a parameter is not described.
252    undescribed = "-- undescribed --"
253
254    def __init__(self, config, fname, xforms):
255        """Initialize internal variables"""
256
257        self.fname = fname
258        self.config = config
259        self.xforms = xforms
260
261        # Initial state for the state machines
262        self.state = state.NORMAL
263
264        # Store entry currently being processed
265        self.entry = None
266
267        # Place all potential outputs into an array
268        self.entries = []
269
270        #
271        # We need Python 3.7 for its "dicts remember the insertion
272        # order" guarantee
273        #
274        global python_warning
275        if (not python_warning and
276            sys.version_info.major == 3 and sys.version_info.minor < 7):
277
278            self.emit_msg(0,
279                          'Python 3.7 or later is required for correct results')
280            python_warning = True
281
282    def emit_msg(self, ln, msg, *, warning=True):
283        """Emit a message"""
284
285        if self.entry:
286            self.entry.emit_msg(ln, msg, warning=warning)
287            return
288
289        log_msg = f"{self.fname}:{ln} {msg}"
290
291        if warning:
292            self.config.log.warning(log_msg)
293        else:
294            self.config.log.info(log_msg)
295
296    def dump_section(self, start_new=True):
297        """
298        Dump section contents to arrays/hashes intended for that purpose.
299        """
300
301        if self.entry:
302            self.entry.dump_section(start_new)
303
304    # TODO: rename it to store_declaration after removal of kernel-doc.pl
305    def output_declaration(self, dtype, name, **args):
306        """
307        Store the entry into an entry array.
308
309        The actual output and output filters will be handled elsewhere.
310        """
311
312        item = KdocItem(name, self.fname, dtype,
313                        self.entry.declaration_start_line, **args)
314        item.warnings = self.entry.warnings
315
316        # Drop empty sections
317        # TODO: improve empty sections logic to emit warnings
318        sections = self.entry.sections
319        for section in ["Description", "Return"]:
320            if section in sections and not sections[section].rstrip():
321                del sections[section]
322        item.set_sections(sections, self.entry.section_start_lines)
323        item.set_params(self.entry.parameterlist, self.entry.parameterdescs,
324                        self.entry.parametertypes,
325                        self.entry.parameterdesc_start_lines)
326        self.entries.append(item)
327
328        self.config.log.debug("Output: %s:%s = %s", dtype, name, pformat(args))
329
330    def emit_unused_warnings(self):
331        """
332        When the parser fails to produce a valid entry, it places some
333        warnings under `entry.warnings` that will be discarded when resetting
334        the state.
335
336        Ensure that those warnings are not lost.
337
338        .. note::
339
340              Because we are calling `config.warning()` here, those
341              warnings are not filtered by the `-W` parameters: they will all
342              be produced even when `-Wreturn`, `-Wshort-desc`, and/or
343              `-Wcontents-before-sections` are used.
344
345              Allowing those warnings to be filtered is complex, because it
346              would require storing them in a buffer and then filtering them
347              during the output step of the code, depending on the
348              selected symbols.
349        """
350        if self.entry and self.entry not in self.entries:
351            for log_msg in self.entry.warnings:
352                self.config.warning(log_msg)
353
354    def reset_state(self, ln):
355        """
356        Ancillary routine to create a new entry. It initializes all
357        variables used by the state machine.
358        """
359
360        self.emit_unused_warnings()
361
362        self.entry = KernelEntry(self.config, self.fname, ln)
363
364        # State flags
365        self.state = state.NORMAL
366
367    def push_parameter(self, ln, decl_type, param, dtype,
368                       org_arg, declaration_name):
369        """
370        Store parameters and their descriptions at self.entry.
371        """
372
373        if self.entry.anon_struct_union and dtype == "" and param == "}":
374            return  # Ignore the ending }; from anonymous struct/union
375
376        self.entry.anon_struct_union = False
377
378        param = KernRe(r'[\[\)].*').sub('', param, count=1)
379
380        #
381        # Look at various "anonymous type" cases.
382        #
383        if dtype == '':
384            if param.endswith("..."):
385                if len(param) > 3: # there is a name provided, use that
386                    param = param[:-3]
387                if not self.entry.parameterdescs.get(param):
388                    self.entry.parameterdescs[param] = "variable arguments"
389
390            elif (not param) or param == "void":
391                param = "void"
392                self.entry.parameterdescs[param] = "no arguments"
393
394            elif param in ["struct", "union"]:
395                # Handle unnamed (anonymous) union or struct
396                dtype = param
397                param = "{unnamed_" + param + "}"
398                self.entry.parameterdescs[param] = "anonymous\n"
399                self.entry.anon_struct_union = True
400
401        # Warn if parameter has no description
402        # (but ignore ones starting with # as these are not parameters
403        # but inline preprocessor statements)
404        if param not in self.entry.parameterdescs and not param.startswith("#"):
405            self.entry.parameterdescs[param] = self.undescribed
406
407            if "." not in param:
408                if decl_type == 'function':
409                    dname = f"{decl_type} parameter"
410                else:
411                    dname = f"{decl_type} member"
412
413                self.emit_msg(ln,
414                              f"{dname} '{param}' not described in '{declaration_name}'")
415
416        # Strip spaces from param so that it is one continuous string on
417        # parameterlist. This fixes a problem where check_sections()
418        # cannot find a parameter like "addr[6 + 2]" because it actually
419        # appears as "addr[6", "+", "2]" on the parameter list.
420        # However, it's better to maintain the param string unchanged for
421        # output, so just weaken the string compare in check_sections()
422        # to ignore "[blah" in a parameter string.
423
424        self.entry.parameterlist.append(param)
425        org_arg = KernRe(r'\s\s+').sub(' ', org_arg)
426        self.entry.parametertypes[param] = org_arg
427
428
429    def create_parameter_list(self, ln, decl_type, args,
430                              splitter, declaration_name):
431        """
432        Creates a list of parameters, storing them at self.entry.
433        """
434
435        # temporarily replace all commas inside function pointer definition
436        arg_expr = KernRe(r'(\([^\),]+),')
437        while arg_expr.search(args):
438            args = arg_expr.sub(r"\1#", args)
439
440        for arg in args.split(splitter):
441            # Ignore argument attributes
442            arg = KernRe(r'\sPOS0?\s').sub(' ', arg)
443
444            # Strip leading/trailing spaces
445            arg = arg.strip()
446            arg = KernRe(r'\s+').sub(' ', arg, count=1)
447
448            if arg.startswith('#'):
449                # Treat preprocessor directive as a typeless variable just to fill
450                # corresponding data structures "correctly". Catch it later in
451                # output_* subs.
452
453                # Treat preprocessor directive as a typeless variable
454                self.push_parameter(ln, decl_type, arg, "",
455                                    "", declaration_name)
456            #
457            # The pointer-to-function case.
458            #
459            elif KernRe(r'\(.+\)\s*\(').search(arg):
460                arg = arg.replace('#', ',')
461                r = KernRe(r'[^\(]+\(\*?\s*'  # Everything up to "(*"
462                           r'([\w\[\].]*)'    # Capture the name and possible [array]
463                           r'\s*\)')	      # Make sure the trailing ")" is there
464                if r.match(arg):
465                    param = r.group(1)
466                else:
467                    self.emit_msg(ln, f"Invalid param: {arg}")
468                    param = arg
469                dtype = arg.replace(param, '')
470                self.push_parameter(ln, decl_type, param, dtype, arg, declaration_name)
471            #
472            # The array-of-pointers case.  Dig the parameter name out from the middle
473            # of the declaration.
474            #
475            elif KernRe(r'\(.+\)\s*\[').search(arg):
476                r = KernRe(r'[^\(]+\(\s*\*\s*'		# Up to "(" and maybe "*"
477                           r'([\w.]*?)'			# The actual pointer name
478                           r'\s*(\[\s*\w+\s*\]\s*)*\)') # The [array portion]
479                if r.match(arg):
480                    param = r.group(1)
481                else:
482                    self.emit_msg(ln, f"Invalid param: {arg}")
483                    param = arg
484                dtype = arg.replace(param, '')
485                self.push_parameter(ln, decl_type, param, dtype, arg, declaration_name)
486            elif arg:
487                #
488                # Clean up extraneous spaces and split the string at commas; the first
489                # element of the resulting list will also include the type information.
490                #
491                arg = KernRe(r'\s*:\s*').sub(":", arg)
492                arg = KernRe(r'\s*\[').sub('[', arg)
493                args = KernRe(r'\s*,\s*').split(arg)
494                args[0] = re.sub(r'(\*+)\s*', r' \1', args[0])
495                #
496                # args[0] has a string of "type a".  If "a" includes an [array]
497                # declaration, we want to not be fooled by any white space inside
498                # the brackets, so detect and handle that case specially.
499                #
500                r = KernRe(r'^([^[\]]*\s+)(.*)$')
501                if r.match(args[0]):
502                    args[0] = r.group(2)
503                    dtype = r.group(1)
504                else:
505                    # No space in args[0]; this seems wrong but preserves previous behavior
506                    dtype = ''
507
508                bitfield_re = KernRe(r'(.*?):(\w+)')
509                for param in args:
510                    #
511                    # For pointers, shift the star(s) from the variable name to the
512                    # type declaration.
513                    #
514                    r = KernRe(r'^(\*+)\s*(.*)')
515                    if r.match(param):
516                        self.push_parameter(ln, decl_type, r.group(2),
517                                            f"{dtype} {r.group(1)}",
518                                            arg, declaration_name)
519                    #
520                    # Perform a similar shift for bitfields.
521                    #
522                    elif bitfield_re.search(param):
523                        if dtype != "":  # Skip unnamed bit-fields
524                            self.push_parameter(ln, decl_type, bitfield_re.group(1),
525                                                f"{dtype}:{bitfield_re.group(2)}",
526                                                arg, declaration_name)
527                    else:
528                        self.push_parameter(ln, decl_type, param, dtype,
529                                            arg, declaration_name)
530
531    def check_sections(self, ln, decl_name, decl_type):
532        """
533        Check for errors inside sections, emitting warnings if not found
534        parameters are described.
535        """
536        for section in self.entry.sections:
537            if section not in self.entry.parameterlist and \
538               not known_sections.search(section):
539                if decl_type == 'function':
540                    dname = f"{decl_type} parameter"
541                else:
542                    dname = f"{decl_type} member"
543                self.emit_msg(ln,
544                              f"Excess {dname} '{section}' description in '{decl_name}'")
545
546    def check_return_section(self, ln, declaration_name, return_type):
547        """
548        If the function doesn't return void, warns about the lack of a
549        return description.
550        """
551
552        if not self.config.wreturn:
553            return
554
555        # Ignore an empty return type (It's a macro)
556        # Ignore functions with a "void" return type (but not "void *")
557        if not return_type or KernRe(r'void\s*\w*\s*$').search(return_type):
558            return
559
560        if not self.entry.sections.get("Return", None):
561            self.emit_msg(ln,
562                          f"No description found for return value of '{declaration_name}'")
563
564    def split_struct_proto(self, proto):
565        """
566        Split apart a structure prototype; returns (struct|union, name,
567        members) or ``None``.
568        """
569
570        type_pattern = r'(struct|union)'
571        qualifiers = [
572            "__attribute__",
573            "__packed",
574            "__aligned",
575            "____cacheline_aligned_in_smp",
576            "____cacheline_aligned",
577        ]
578        definition_body = r'\{(.*)\}\s*' + "(?:" + '|'.join(qualifiers) + ")?"
579
580        r = KernRe(type_pattern + r'\s+(\w+)\s*' + definition_body)
581        if r.search(proto):
582            return (r.group(1), r.group(2), r.group(3))
583        else:
584            r = KernRe(r'typedef\s+' + type_pattern + r'\s*' + definition_body + r'\s*(\w+)\s*;')
585            if r.search(proto):
586                return (r.group(1), r.group(3), r.group(2))
587        return None
588
589    def rewrite_struct_members(self, members):
590        """
591        Process ``struct``/``union`` members from the most deeply nested
592        outward.
593
594        Rewrite the members of a ``struct`` or ``union`` for easier formatting
595        later on. Among other things, this function will turn a member like::
596
597          struct { inner_members; } foo;
598
599        into::
600
601          struct foo; inner_members;
602        """
603
604        #
605        # The trick is in the ``^{`` below - it prevents a match of an outer
606        # ``struct``/``union`` until the inner one has been munged
607        # (removing the ``{`` in the process).
608        #
609        struct_members = KernRe(r'(struct|union)'   # 0: declaration type
610                                r'([^\{\};]+)' 	    # 1: possible name
611                                r'(\{)'
612                                r'([^\{\}]*)'       # 3: Contents of declaration
613                                r'(\})'
614                                r'([^\{\};]*)(;)')  # 5: Remaining stuff after declaration
615        tuples = struct_members.findall(members)
616        while tuples:
617            for t in tuples:
618                newmember = ""
619                oldmember = "".join(t) # Reconstruct the original formatting
620                dtype, name, lbr, content, rbr, rest, semi = t
621                #
622                # Pass through each field name, normalizing the form and formatting.
623                #
624                for s_id in rest.split(','):
625                    s_id = s_id.strip()
626                    newmember += f"{dtype} {s_id}; "
627                    #
628                    # Remove bitfield/array/pointer info, getting the bare name.
629                    #
630                    s_id = KernRe(r'[:\[].*').sub('', s_id)
631                    s_id = KernRe(r'^\s*\**(\S+)\s*').sub(r'\1', s_id)
632                    #
633                    # Pass through the members of this inner structure/union.
634                    #
635                    for arg in content.split(';'):
636                        arg = arg.strip()
637                        #
638                        # Look for (type)(*name)(args) - pointer to function
639                        #
640                        r = KernRe(r'^([^\(]+\(\*?\s*)([\w.]*)(\s*\).*)')
641                        if r.match(arg):
642                            dtype, name, extra = r.group(1), r.group(2), r.group(3)
643                            # Pointer-to-function
644                            if not s_id:
645                                # Anonymous struct/union
646                                newmember += f"{dtype}{name}{extra}; "
647                            else:
648                                newmember += f"{dtype}{s_id}.{name}{extra}; "
649                        #
650                        # Otherwise a non-function member.
651                        #
652                        else:
653                            #
654                            # Remove bitmap and array portions and spaces around commas
655                            #
656                            arg = KernRe(r':\s*\d+\s*').sub('', arg)
657                            arg = KernRe(r'\[.*\]').sub('', arg)
658                            arg = KernRe(r'\s*,\s*').sub(',', arg)
659                            #
660                            # Look for a normal decl - "type name[,name...]"
661                            #
662                            r = KernRe(r'(.*)\s+([\S+,]+)')
663                            if r.search(arg):
664                                for name in r.group(2).split(','):
665                                    name = KernRe(r'^\s*\**(\S+)\s*').sub(r'\1', name)
666                                    if not s_id:
667                                        # Anonymous struct/union
668                                        newmember += f"{r.group(1)} {name}; "
669                                    else:
670                                        newmember += f"{r.group(1)} {s_id}.{name}; "
671                            else:
672                                newmember += f"{arg}; "
673                #
674                # At the end of the s_id loop, replace the original declaration with
675                # the munged version.
676                #
677                members = members.replace(oldmember, newmember)
678            #
679            # End of the tuple loop - search again and see if there are outer members
680            # that now turn up.
681            #
682            tuples = struct_members.findall(members)
683        return members
684
685    def format_struct_decl(self, declaration):
686        """
687        Format the ``struct`` declaration into a standard form for inclusion
688        in the resulting docs.
689        """
690
691        #
692        # Insert newlines, get rid of extra spaces.
693        #
694        declaration = KernRe(r'([\{;])').sub(r'\1\n', declaration)
695        declaration = KernRe(r'\}\s+;').sub('};', declaration)
696        #
697        # Format inline enums with each member on its own line.
698        #
699        r = KernRe(r'(enum\s+\{[^\}]+),([^\n])')
700        while r.search(declaration):
701            declaration = r.sub(r'\1,\n\2', declaration)
702        #
703        # Now go through and supply the right number of tabs
704        # for each line.
705        #
706        def_args = declaration.split('\n')
707        level = 1
708        declaration = ""
709        for clause in def_args:
710            clause = KernRe(r'\s+').sub(' ', clause.strip(), count=1)
711            if clause:
712                if '}' in clause and level > 1:
713                    level -= 1
714                if not clause.startswith('#'):
715                    declaration += "\t" * level
716                declaration += "\t" + clause + "\n"
717                if "{" in clause and "}" not in clause:
718                    level += 1
719        return declaration
720
721
722    def dump_struct(self, ln, proto):
723        """
724        Store an entry for a ``struct`` or ``union``
725        """
726        #
727        # Do the basic parse to get the pieces of the declaration.
728        #
729        struct_parts = self.split_struct_proto(proto)
730        if not struct_parts:
731            self.emit_msg(ln, f"{proto} error: Cannot parse struct or union!")
732            return
733        decl_type, declaration_name, members = struct_parts
734
735        if self.entry.identifier != declaration_name:
736            self.emit_msg(ln, f"expecting prototype for {decl_type} {self.entry.identifier}. "
737                          f"Prototype was for {decl_type} {declaration_name} instead\n")
738            return
739        #
740        # Go through the list of members applying all of our transformations.
741        #
742        members = trim_private_members(members)
743        members = self.xforms.apply("struct", members)
744
745        #
746        # Deal with embedded struct and union members, and drop enums entirely.
747        #
748        declaration = members
749        members = self.rewrite_struct_members(members)
750        members = re.sub(r'(\{[^\{\}]*\})', '', members)
751        #
752        # Output the result and we are done.
753        #
754        self.create_parameter_list(ln, decl_type, members, ';',
755                                   declaration_name)
756        self.check_sections(ln, declaration_name, decl_type)
757        self.output_declaration(decl_type, declaration_name,
758                                definition=self.format_struct_decl(declaration),
759                                purpose=self.entry.declaration_purpose)
760
761    def dump_enum(self, ln, proto):
762        """
763        Store an ``enum`` inside self.entries array.
764        """
765        #
766        # Strip preprocessor directives.  Note that this depends on the
767        # trailing semicolon we added in process_proto_type().
768        #
769        proto = KernRe(r'#\s*((define|ifdef|if)\s+|endif)[^;]*;', flags=re.S).sub('', proto)
770        #
771        # Parse out the name and members of the enum.  Typedef form first.
772        #
773        r = KernRe(r'typedef\s+enum\s*\{(.*)\}\s*(\w*)\s*;')
774        if r.search(proto):
775            declaration_name = r.group(2)
776            members = trim_private_members(r.group(1))
777        #
778        # Failing that, look for a straight enum
779        #
780        else:
781            r = KernRe(r'enum\s+(\w*)\s*\{(.*)\}')
782            if r.match(proto):
783                declaration_name = r.group(1)
784                members = trim_private_members(r.group(2))
785        #
786        # OK, this isn't going to work.
787        #
788            else:
789                self.emit_msg(ln, f"{proto}: error: Cannot parse enum!")
790                return
791        #
792        # Make sure we found what we were expecting.
793        #
794        if self.entry.identifier != declaration_name:
795            if self.entry.identifier == "":
796                self.emit_msg(ln,
797                              f"{proto}: wrong kernel-doc identifier on prototype")
798            else:
799                self.emit_msg(ln,
800                              f"expecting prototype for enum {self.entry.identifier}. "
801                              f"Prototype was for enum {declaration_name} instead")
802            return
803
804        if not declaration_name:
805            declaration_name = "(anonymous)"
806        #
807        # Parse out the name of each enum member, and verify that we
808        # have a description for it.
809        #
810        member_set = set()
811        members = KernRe(r'\([^;)]*\)').sub('', members)
812        for arg in members.split(','):
813            if not arg:
814                continue
815            arg = KernRe(r'^\s*(\w+).*').sub(r'\1', arg)
816            self.entry.parameterlist.append(arg)
817            if arg not in self.entry.parameterdescs:
818                self.entry.parameterdescs[arg] = self.undescribed
819                self.emit_msg(ln,
820                              f"Enum value '{arg}' not described in enum '{declaration_name}'")
821            member_set.add(arg)
822        #
823        # Ensure that every described member actually exists in the enum.
824        #
825        for k in self.entry.parameterdescs:
826            if k not in member_set:
827                self.emit_msg(ln,
828                              f"Excess enum value '@{k}' description in '{declaration_name}'")
829
830        self.output_declaration('enum', declaration_name,
831                                purpose=self.entry.declaration_purpose)
832
833    def dump_var(self, ln, proto):
834        """
835        Store variables that are part of kAPI.
836        """
837        VAR_ATTRIBS = [
838            "extern",
839            "const",
840        ]
841        OPTIONAL_VAR_ATTR = r"^(?:\b(?:" +"|".join(VAR_ATTRIBS) +r")\b\s*)*"
842
843        #
844        # Store the full prototype before modifying it
845        #
846        full_proto = proto
847        declaration_name = None
848
849        #
850        # Handle macro definitions
851        #
852        macro_prefixes = [
853            KernRe(r"DEFINE_[\w_]+\s*\(([\w_]+)\)"),
854        ]
855
856        for r in macro_prefixes:
857            match = r.search(proto)
858            if match:
859                declaration_name = match.group(1)
860                break
861
862        #
863        # Drop comments and macros to have a pure C prototype
864        #
865        if not declaration_name:
866            proto = self.xforms.apply("var", proto)
867
868        proto = proto.rstrip()
869
870        #
871        # Variable name is at the end of the declaration
872        #
873
874        default_val = None
875
876        r= KernRe(OPTIONAL_VAR_ATTR + r"\s*[\w_\s]*\s+(?:\*+)?([\w_]+)\s*[\d\]\[]*\s*(=.*)?")
877        if r.match(proto):
878            if not declaration_name:
879                declaration_name = r.group(1)
880
881            default_val = r.group(2)
882        else:
883            r= KernRe(OPTIONAL_VAR_ATTR + r"(?:[\w_\s]*)?\s+(?:\*+)?(?:[\w_]+)\s*[\d\]\[]*\s*(=.*)?")
884
885            if r.match(proto):
886                default_val = r.group(1)
887        if not declaration_name:
888           self.emit_msg(ln,f"{proto}: can't parse variable")
889           return
890
891        if default_val:
892            default_val = default_val.lstrip("=").strip()
893
894        self.output_declaration("var", declaration_name,
895                                full_proto=full_proto,
896                                default_val=default_val,
897                                purpose=self.entry.declaration_purpose)
898
899    def dump_declaration(self, ln, prototype):
900        """
901        Store a data declaration inside self.entries array.
902        """
903
904        if self.entry.decl_type == "enum":
905            self.dump_enum(ln, prototype)
906        elif self.entry.decl_type == "typedef":
907            self.dump_typedef(ln, prototype)
908        elif self.entry.decl_type in ["union", "struct"]:
909            self.dump_struct(ln, prototype)
910        elif self.entry.decl_type == "var":
911            self.dump_var(ln, prototype)
912        else:
913            # This would be a bug
914            self.emit_message(ln, f'Unknown declaration type: {self.entry.decl_type}')
915
916    def dump_function(self, ln, prototype):
917        """
918        Store a function or function macro inside self.entries array.
919        """
920
921        found = func_macro = False
922        return_type = ''
923        decl_type = 'function'
924
925        #
926        # If we have a macro, remove the "#define" at the front.
927        #
928        new_proto = KernRe(r"^#\s*define\s+").sub("", prototype)
929        if new_proto != prototype:
930            prototype = new_proto
931            #
932            # Dispense with the simple "#define A B" case here; the key
933            # is the space after the name of the symbol being defined.
934            # NOTE that the seemingly misnamed "func_macro" indicates a
935            # macro *without* arguments.
936            #
937            r = KernRe(r'^(\w+)\s+')
938            if r.search(prototype):
939                return_type = ''
940                declaration_name = r.group(1)
941                func_macro = True
942                found = True
943        else:
944            #
945            # Apply the initial transformations.
946            #
947            prototype = self.xforms.apply("func", prototype)
948
949        # Yes, this truly is vile.  We are looking for:
950        # 1. Return type (may be nothing if we're looking at a macro)
951        # 2. Function name
952        # 3. Function parameters.
953        #
954        # All the while we have to watch out for function pointer parameters
955        # (which IIRC is what the two sections are for), C types (these
956        # regexps don't even start to express all the possibilities), and
957        # so on.
958        #
959        # If you mess with these regexps, it's a good idea to check that
960        # the following functions' documentation still comes out right:
961        # - parport_register_device (function pointer parameters)
962        # - atomic_set (macro)
963        # - pci_match_device, __copy_to_user (long return type)
964
965        name = r'\w+'
966        type1 = r'(?:[\w\s]+)?'
967        type2 = r'(?:[\w\s]+\*+)+'
968        #
969        # Attempt to match first on (args) with no internal parentheses; this
970        # lets us easily filter out __acquires() and other post-args stuff.  If
971        # that fails, just grab the rest of the line to the last closing
972        # parenthesis.
973        #
974        proto_args = r'\(([^\(]*|.*)\)'
975        #
976        # (Except for the simple macro case) attempt to split up the prototype
977        # in the various ways we understand.
978        #
979        if not found:
980            patterns = [
981                rf'^()({name})\s*{proto_args}',
982                rf'^({type1})\s+({name})\s*{proto_args}',
983                rf'^({type2})\s*({name})\s*{proto_args}',
984            ]
985
986            for p in patterns:
987                r = KernRe(p)
988                if r.match(prototype):
989                    return_type = r.group(1)
990                    declaration_name = r.group(2)
991                    args = r.group(3)
992                    self.create_parameter_list(ln, decl_type, args, ',',
993                                               declaration_name)
994                    found = True
995                    break
996        #
997        # Parsing done; make sure that things are as we expect.
998        #
999        if not found:
1000            self.emit_msg(ln,
1001                          f"cannot understand function prototype: '{prototype}'")
1002            return
1003        if self.entry.identifier != declaration_name:
1004            self.emit_msg(ln, f"expecting prototype for {self.entry.identifier}(). "
1005                          f"Prototype was for {declaration_name}() instead")
1006            return
1007        self.check_sections(ln, declaration_name, "function")
1008        self.check_return_section(ln, declaration_name, return_type)
1009        #
1010        # Store the result.
1011        #
1012        self.output_declaration(decl_type, declaration_name,
1013                                typedef=('typedef' in return_type),
1014                                functiontype=return_type,
1015                                purpose=self.entry.declaration_purpose,
1016                                func_macro=func_macro)
1017
1018
1019    def dump_typedef(self, ln, proto):
1020        """
1021        Store a ``typedef`` inside self.entries array.
1022        """
1023        #
1024        # We start by looking for function typedefs.
1025        #
1026        typedef_type = r'typedef((?:\s+[\w*]+\b){0,7}\s+(?:\w+\b|\*+))\s*'
1027        typedef_ident = r'\*?\s*(\w\S+)\s*'
1028        typedef_args = r'\s*\((.*)\);'
1029
1030        typedef1 = KernRe(typedef_type + r'\(' + typedef_ident + r'\)' + typedef_args)
1031        typedef2 = KernRe(typedef_type + typedef_ident + typedef_args)
1032
1033        # Parse function typedef prototypes
1034        for r in [typedef1, typedef2]:
1035            if not r.match(proto):
1036                continue
1037
1038            return_type = r.group(1).strip()
1039            declaration_name = r.group(2)
1040            args = r.group(3)
1041
1042            if self.entry.identifier != declaration_name:
1043                self.emit_msg(ln,
1044                              f"expecting prototype for typedef {self.entry.identifier}. Prototype was for typedef {declaration_name} instead\n")
1045                return
1046
1047            self.create_parameter_list(ln, 'function', args, ',', declaration_name)
1048
1049            self.output_declaration('function', declaration_name,
1050                                    typedef=True,
1051                                    functiontype=return_type,
1052                                    purpose=self.entry.declaration_purpose)
1053            return
1054        #
1055        # Not a function, try to parse a simple typedef.
1056        #
1057        r = KernRe(r'typedef.*\s+(\w+)\s*;')
1058        if r.match(proto):
1059            declaration_name = r.group(1)
1060
1061            if self.entry.identifier != declaration_name:
1062                self.emit_msg(ln,
1063                              f"expecting prototype for typedef {self.entry.identifier}. Prototype was for typedef {declaration_name} instead\n")
1064                return
1065
1066            self.output_declaration('typedef', declaration_name,
1067                                    purpose=self.entry.declaration_purpose)
1068            return
1069
1070        self.emit_msg(ln, "error: Cannot parse typedef!")
1071
1072    @staticmethod
1073    def process_export(function_set, line):
1074        """
1075        process ``EXPORT_SYMBOL*`` tags
1076
1077        This method doesn't use any variable from the class, so declare it
1078        with a staticmethod decorator.
1079        """
1080
1081        # We support documenting some exported symbols with different
1082        # names.  A horrible hack.
1083        suffixes = [ '_noprof' ]
1084
1085        # Note: it accepts only one EXPORT_SYMBOL* per line, as having
1086        # multiple export lines would violate Kernel coding style.
1087
1088        if export_symbol.search(line):
1089            symbol = export_symbol.group(2)
1090        elif export_symbol_ns.search(line):
1091            symbol = export_symbol_ns.group(2)
1092        else:
1093            return False
1094        #
1095        # Found an export, trim out any special suffixes
1096        #
1097        for suffix in suffixes:
1098            # Be backward compatible with Python < 3.9
1099            if symbol.endswith(suffix):
1100                symbol = symbol[:-len(suffix)]
1101        function_set.add(symbol)
1102        return True
1103
1104    def process_normal(self, ln, line):
1105        """
1106        STATE_NORMAL: looking for the ``/**`` to begin everything.
1107        """
1108
1109        if not doc_start.match(line):
1110            return
1111
1112        # start a new entry
1113        self.reset_state(ln)
1114
1115        # next line is always the function name
1116        self.state = state.NAME
1117
1118    def process_name(self, ln, line):
1119        """
1120        STATE_NAME: Looking for the "name - description" line
1121        """
1122        #
1123        # Check for a DOC: block and handle them specially.
1124        #
1125        if doc_block.search(line):
1126
1127            if not doc_block.group(1):
1128                self.entry.begin_section(ln, "Introduction")
1129            else:
1130                self.entry.begin_section(ln, doc_block.group(1))
1131
1132            self.entry.identifier = self.entry.section
1133            self.state = state.DOCBLOCK
1134        #
1135        # Otherwise we're looking for a normal kerneldoc declaration line.
1136        #
1137        elif doc_decl.search(line):
1138            self.entry.identifier = doc_decl.group(1)
1139
1140            # Test for data declaration
1141            if doc_begin_data.search(line):
1142                self.entry.decl_type = doc_begin_data.group(1)
1143                self.entry.identifier = doc_begin_data.group(2)
1144            #
1145            # Look for a function description
1146            #
1147            elif doc_begin_func.search(line):
1148                self.entry.identifier = doc_begin_func.group(1)
1149                self.entry.decl_type = "function"
1150            #
1151            # We struck out.
1152            #
1153            else:
1154                self.emit_msg(ln,
1155                              f"This comment starts with '/**', but isn't a kernel-doc comment. Refer to Documentation/doc-guide/kernel-doc.rst\n{line}")
1156                self.state = state.NORMAL
1157                return
1158            #
1159            # OK, set up for a new kerneldoc entry.
1160            #
1161            self.state = state.BODY
1162            self.entry.identifier = self.entry.identifier.strip(" ")
1163            # if there's no @param blocks need to set up default section here
1164            self.entry.begin_section(ln + 1)
1165            #
1166            # Find the description portion, which *should* be there but
1167            # isn't always.
1168            # (We should be able to capture this from the previous parsing - someday)
1169            #
1170            r = KernRe("[-:](.*)")
1171            if r.search(line):
1172                self.entry.declaration_purpose = trim_whitespace(r.group(1))
1173                self.state = state.DECLARATION
1174            else:
1175                self.entry.declaration_purpose = ""
1176
1177            if not self.entry.declaration_purpose and self.config.wshort_desc:
1178                self.emit_msg(ln,
1179                              f"missing initial short description on line:\n{line}")
1180
1181            if not self.entry.identifier and self.entry.decl_type != "enum":
1182                self.emit_msg(ln,
1183                              f"wrong kernel-doc identifier on line:\n{line}")
1184                self.state = state.NORMAL
1185
1186            if self.config.verbose:
1187                self.emit_msg(ln,
1188                              f"Scanning doc for {self.entry.decl_type} {self.entry.identifier}",
1189                                  warning=False)
1190        #
1191        # Failed to find an identifier. Emit a warning
1192        #
1193        else:
1194            self.emit_msg(ln, f"Cannot find identifier on line:\n{line}")
1195
1196    def is_new_section(self, ln, line):
1197        """
1198        Helper function to determine if a new section is being started.
1199        """
1200        if doc_sect.search(line):
1201            self.state = state.BODY
1202            #
1203            # Pick out the name of our new section, tweaking it if need be.
1204            #
1205            newsection = doc_sect.group(1)
1206            if newsection.lower() == 'description':
1207                newsection = 'Description'
1208            elif newsection.lower() == 'context':
1209                newsection = 'Context'
1210                self.state = state.SPECIAL_SECTION
1211            elif newsection.lower() in ["@return", "@returns",
1212                                        "return", "returns"]:
1213                newsection = "Return"
1214                self.state = state.SPECIAL_SECTION
1215            elif newsection[0] == '@':
1216                self.state = state.SPECIAL_SECTION
1217            #
1218            # Initialize the contents, and get the new section going.
1219            #
1220            newcontents = doc_sect.group(2)
1221            if not newcontents:
1222                newcontents = ""
1223            self.dump_section()
1224            self.entry.begin_section(ln, newsection)
1225            self.entry.leading_space = None
1226
1227            self.entry.add_text(newcontents.lstrip())
1228            return True
1229        return False
1230
1231    def is_comment_end(self, ln, line):
1232        """
1233        Helper function to detect (and effect) the end of a kerneldoc comment.
1234        """
1235        if doc_end.search(line):
1236            self.dump_section()
1237
1238            # Look for doc_com + <text> + doc_end:
1239            r = KernRe(r'\s*\*\s*[a-zA-Z_0-9:.]+\*/')
1240            if r.match(line):
1241                self.emit_msg(ln, f"suspicious ending line: {line}")
1242
1243            self.entry.prototype = ""
1244            self.entry.new_start_line = ln + 1
1245
1246            self.state = state.PROTO
1247            return True
1248        return False
1249
1250
1251    def process_decl(self, ln, line):
1252        """
1253        STATE_DECLARATION: We've seen the beginning of a declaration.
1254        """
1255        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
1256            return
1257        #
1258        # Look for anything with the " * " line beginning.
1259        #
1260        if doc_content.search(line):
1261            cont = doc_content.group(1)
1262            #
1263            # A blank line means that we have moved out of the declaration
1264            # part of the comment (without any "special section" parameter
1265            # descriptions).
1266            #
1267            if cont == "":
1268                self.state = state.BODY
1269            #
1270            # Otherwise we have more of the declaration section to soak up.
1271            #
1272            else:
1273                self.entry.declaration_purpose = \
1274                    trim_whitespace(self.entry.declaration_purpose + ' ' + cont)
1275        else:
1276            # Unknown line, ignore
1277            self.emit_msg(ln, f"bad line: {line}")
1278
1279
1280    def process_special(self, ln, line):
1281        """
1282        STATE_SPECIAL_SECTION: a section ending with a blank line.
1283        """
1284        #
1285        # If we have hit a blank line (only the " * " marker), then this
1286        # section is done.
1287        #
1288        if KernRe(r"\s*\*\s*$").match(line):
1289            self.entry.begin_section(ln, dump = True)
1290            self.state = state.BODY
1291            return
1292        #
1293        # Not a blank line, look for the other ways to end the section.
1294        #
1295        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
1296            return
1297        #
1298        # OK, we should have a continuation of the text for this section.
1299        #
1300        if doc_content.search(line):
1301            cont = doc_content.group(1)
1302            #
1303            # If the lines of text after the first in a special section have
1304            # leading white space, we need to trim it out or Sphinx will get
1305            # confused.  For the second line (the None case), see what we
1306            # find there and remember it.
1307            #
1308            if self.entry.leading_space is None:
1309                r = KernRe(r'^(\s+)')
1310                if r.match(cont):
1311                    self.entry.leading_space = len(r.group(1))
1312                else:
1313                    self.entry.leading_space = 0
1314            #
1315            # Otherwise, before trimming any leading chars, be *sure*
1316            # that they are white space.  We should maybe warn if this
1317            # isn't the case.
1318            #
1319            for i in range(0, self.entry.leading_space):
1320                if cont[i] != " ":
1321                    self.entry.leading_space = i
1322                    break
1323            #
1324            # Add the trimmed result to the section and we're done.
1325            #
1326            self.entry.add_text(cont[self.entry.leading_space:])
1327        else:
1328            # Unknown line, ignore
1329            self.emit_msg(ln, f"bad line: {line}")
1330
1331    def process_body(self, ln, line):
1332        """
1333        STATE_BODY: the bulk of a kerneldoc comment.
1334        """
1335        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
1336            return
1337
1338        if doc_content.search(line):
1339            cont = doc_content.group(1)
1340            self.entry.add_text(cont)
1341        else:
1342            # Unknown line, ignore
1343            self.emit_msg(ln, f"bad line: {line}")
1344
1345    def process_inline_name(self, ln, line):
1346        """STATE_INLINE_NAME: beginning of docbook comments within a prototype."""
1347
1348        if doc_inline_sect.search(line):
1349            self.entry.begin_section(ln, doc_inline_sect.group(1))
1350            self.entry.add_text(doc_inline_sect.group(2).lstrip())
1351            self.state = state.INLINE_TEXT
1352        elif doc_inline_end.search(line):
1353            self.dump_section()
1354            self.state = state.PROTO
1355        elif doc_content.search(line):
1356            self.emit_msg(ln, f"Incorrect use of kernel-doc format: {line}")
1357            self.state = state.PROTO
1358        # else ... ??
1359
1360    def process_inline_text(self, ln, line):
1361        """STATE_INLINE_TEXT: docbook comments within a prototype."""
1362
1363        if doc_inline_end.search(line):
1364            self.dump_section()
1365            self.state = state.PROTO
1366        elif doc_content.search(line):
1367            self.entry.add_text(doc_content.group(1))
1368        # else ... ??
1369
1370    def syscall_munge(self, ln, proto):         # pylint: disable=W0613
1371        """
1372        Handle syscall definitions.
1373        """
1374
1375        is_void = False
1376
1377        # Strip newlines/CR's
1378        proto = re.sub(r'[\r\n]+', ' ', proto)
1379
1380        # Check if it's a SYSCALL_DEFINE0
1381        if 'SYSCALL_DEFINE0' in proto:
1382            is_void = True
1383
1384        # Replace SYSCALL_DEFINE with correct return type & function name
1385        proto = KernRe(r'SYSCALL_DEFINE.*\(').sub('long sys_', proto)
1386
1387        r = KernRe(r'long\s+(sys_.*?),')
1388        if r.search(proto):
1389            proto = KernRe(',').sub('(', proto, count=1)
1390        elif is_void:
1391            proto = KernRe(r'\)').sub('(void)', proto, count=1)
1392
1393        # Now delete all of the odd-numbered commas in the proto
1394        # so that argument types & names don't have a comma between them
1395        count = 0
1396        length = len(proto)
1397
1398        if is_void:
1399            length = 0  # skip the loop if is_void
1400
1401        for ix in range(length):
1402            if proto[ix] == ',':
1403                count += 1
1404                if count % 2 == 1:
1405                    proto = proto[:ix] + ' ' + proto[ix + 1:]
1406
1407        return proto
1408
1409    def tracepoint_munge(self, ln, proto):
1410        """
1411        Handle tracepoint definitions.
1412        """
1413
1414        tracepointname = None
1415        tracepointargs = None
1416
1417        # Match tracepoint name based on different patterns
1418        r = KernRe(r'TRACE_EVENT\((.*?),')
1419        if r.search(proto):
1420            tracepointname = r.group(1)
1421
1422        r = KernRe(r'DEFINE_SINGLE_EVENT\((.*?),')
1423        if r.search(proto):
1424            tracepointname = r.group(1)
1425
1426        r = KernRe(r'DEFINE_EVENT\((.*?),(.*?),')
1427        if r.search(proto):
1428            tracepointname = r.group(2)
1429
1430        if tracepointname:
1431            tracepointname = tracepointname.lstrip()
1432
1433        r = KernRe(r'TP_PROTO\((.*?)\)')
1434        if r.search(proto):
1435            tracepointargs = r.group(1)
1436
1437        if not tracepointname or not tracepointargs:
1438            self.emit_msg(ln,
1439                          f"Unrecognized tracepoint format:\n{proto}\n")
1440        else:
1441            proto = f"static inline void trace_{tracepointname}({tracepointargs})"
1442            self.entry.identifier = f"trace_{self.entry.identifier}"
1443
1444        return proto
1445
1446    def process_proto_function(self, ln, line):
1447        """Ancillary routine to process a function prototype."""
1448
1449        # strip C99-style comments to end of line
1450        line = KernRe(r"//.*$", re.S).sub('', line)
1451        #
1452        # Soak up the line's worth of prototype text, stopping at { or ; if present.
1453        #
1454        if KernRe(r'\s*#\s*define').match(line):
1455            self.entry.prototype = line
1456        elif not line.startswith('#'):   # skip other preprocessor stuff
1457            r = KernRe(r'([^\{]*)')
1458            if r.match(line):
1459                self.entry.prototype += r.group(1) + " "
1460        #
1461        # If we now have the whole prototype, clean it up and declare victory.
1462        #
1463        if '{' in line or ';' in line or KernRe(r'\s*#\s*define').match(line):
1464            # strip comments and surrounding spaces
1465            self.entry.prototype = KernRe(r'/\*.*\*/').sub('', self.entry.prototype).strip()
1466            #
1467            # Handle self.entry.prototypes for function pointers like:
1468            #       int (*pcs_config)(struct foo)
1469            # by turning it into
1470            #	    int pcs_config(struct foo)
1471            #
1472            r = KernRe(r'^(\S+\s+)\(\s*\*(\S+)\)')
1473            self.entry.prototype = r.sub(r'\1\2', self.entry.prototype)
1474            #
1475            # Handle special declaration syntaxes
1476            #
1477            if 'SYSCALL_DEFINE' in self.entry.prototype:
1478                self.entry.prototype = self.syscall_munge(ln,
1479                                                          self.entry.prototype)
1480            else:
1481                r = KernRe(r'TRACE_EVENT|DEFINE_EVENT|DEFINE_SINGLE_EVENT')
1482                if r.search(self.entry.prototype):
1483                    self.entry.prototype = self.tracepoint_munge(ln,
1484                                                                 self.entry.prototype)
1485            #
1486            # ... and we're done
1487            #
1488            self.dump_function(ln, self.entry.prototype)
1489            self.reset_state(ln)
1490
1491    def process_proto_type(self, ln, line):
1492        """
1493        Ancillary routine to process a type.
1494        """
1495
1496        # Strip C99-style comments and surrounding whitespace
1497        line = KernRe(r"//.*$", re.S).sub('', line).strip()
1498        if not line:
1499            return # nothing to see here
1500
1501        # To distinguish preprocessor directive from regular declaration later.
1502        if line.startswith('#'):
1503            line += ";"
1504        #
1505        # Split the declaration on any of { } or ;, and accumulate pieces
1506        # until we hit a semicolon while not inside {brackets}
1507        #
1508        r = KernRe(r'(.*?)([{};])')
1509        for chunk in r.split(line):
1510            if chunk:  # Ignore empty matches
1511                self.entry.prototype += chunk
1512                #
1513                # This cries out for a match statement ... someday after we can
1514                # drop Python 3.9 ...
1515                #
1516                if chunk == '{':
1517                    self.entry.brcount += 1
1518                elif chunk == '}':
1519                    self.entry.brcount -= 1
1520                elif chunk == ';' and self.entry.brcount <= 0:
1521                    self.dump_declaration(ln, self.entry.prototype)
1522                    self.reset_state(ln)
1523                    return
1524        #
1525        # We hit the end of the line while still in the declaration; put
1526        # in a space to represent the newline.
1527        #
1528        self.entry.prototype += ' '
1529
1530    def process_proto(self, ln, line):
1531        """STATE_PROTO: reading a function/whatever prototype."""
1532
1533        if doc_inline_oneline.search(line):
1534            self.entry.begin_section(ln, doc_inline_oneline.group(1))
1535            self.entry.add_text(doc_inline_oneline.group(2))
1536            self.dump_section()
1537
1538        elif doc_inline_start.search(line):
1539            self.state = state.INLINE_NAME
1540
1541        elif self.entry.decl_type == 'function':
1542            self.process_proto_function(ln, line)
1543
1544        else:
1545            self.process_proto_type(ln, line)
1546
1547    def process_docblock(self, ln, line):
1548        """STATE_DOCBLOCK: within a ``DOC:`` block."""
1549
1550        if doc_end.search(line):
1551            self.dump_section()
1552            self.output_declaration("doc", self.entry.identifier)
1553            self.reset_state(ln)
1554
1555        elif doc_content.search(line):
1556            self.entry.add_text(doc_content.group(1))
1557
1558    def parse_export(self):
1559        """
1560        Parses ``EXPORT_SYMBOL*`` macros from a single Kernel source file.
1561        """
1562
1563        export_table = set()
1564
1565        try:
1566            with open(self.fname, "r", encoding="utf8",
1567                      errors="backslashreplace") as fp:
1568
1569                for line in fp:
1570                    self.process_export(export_table, line)
1571
1572        except IOError:
1573            return None
1574
1575        return export_table
1576
1577    #: The state/action table telling us which function to invoke in each state.
1578    state_actions = {
1579        state.NORMAL:			process_normal,
1580        state.NAME:			process_name,
1581        state.BODY:			process_body,
1582        state.DECLARATION:		process_decl,
1583        state.SPECIAL_SECTION:		process_special,
1584        state.INLINE_NAME:		process_inline_name,
1585        state.INLINE_TEXT:		process_inline_text,
1586        state.PROTO:			process_proto,
1587        state.DOCBLOCK:			process_docblock,
1588        }
1589
1590    def parse_kdoc(self):
1591        """
1592        Open and process each line of a C source file.
1593        The parsing is controlled via a state machine, and the line is passed
1594        to a different process function depending on the state. The process
1595        function may update the state as needed.
1596
1597        Besides parsing kernel-doc tags, it also parses export symbols.
1598        """
1599
1600        prev = ""
1601        prev_ln = None
1602        export_table = set()
1603
1604        try:
1605            with open(self.fname, "r", encoding="utf8",
1606                      errors="backslashreplace") as fp:
1607                for ln, line in enumerate(fp):
1608
1609                    line = line.expandtabs().strip("\n")
1610
1611                    # Group continuation lines on prototypes
1612                    if self.state == state.PROTO:
1613                        if line.endswith("\\"):
1614                            prev += line.rstrip("\\")
1615                            if not prev_ln:
1616                                prev_ln = ln
1617                            continue
1618
1619                        if prev:
1620                            ln = prev_ln
1621                            line = prev + line
1622                            prev = ""
1623                            prev_ln = None
1624
1625                    self.config.log.debug("%d %s: %s",
1626                                          ln, state.name[self.state],
1627                                          line)
1628
1629                    # This is an optimization over the original script.
1630                    # There, when export_file was used for the same file,
1631                    # it was read twice. Here, we use the already-existing
1632                    # loop to parse exported symbols as well.
1633                    #
1634                    if (self.state != state.NORMAL) or \
1635                       not self.process_export(export_table, line):
1636                        # Hand this line to the appropriate state handler
1637                        self.state_actions[self.state](self, ln, line)
1638
1639            self.emit_unused_warnings()
1640
1641        except OSError:
1642            self.config.log.error(f"Error: Cannot open file {self.fname}")
1643
1644        return export_table, self.entries
1645