xref: /linux/scripts/lib/kdoc/kdoc_parser.py (revision ee2fe81cdcd17f875aeca074afe64d7e8f57750f)
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"""
8kdoc_parser
9===========
10
11Read a C language source or header FILE and extract embedded
12documentation comments
13"""
14
15import sys
16import re
17from pprint import pformat
18
19from kdoc_re import NestedMatch, KernRe
20from kdoc_item import KdocItem
21
22#
23# Regular expressions used to parse kernel-doc markups at KernelDoc class.
24#
25# Let's declare them in lowercase outside any class to make easier to
26# convert from the python script.
27#
28# As those are evaluated at the beginning, no need to cache them
29#
30
31# Allow whitespace at end of comment start.
32doc_start = KernRe(r'^/\*\*\s*$', cache=False)
33
34doc_end = KernRe(r'\*/', cache=False)
35doc_com = KernRe(r'\s*\*\s*', cache=False)
36doc_com_body = KernRe(r'\s*\* ?', cache=False)
37doc_decl = doc_com + KernRe(r'(\w+)', cache=False)
38
39# @params and a strictly limited set of supported section names
40# Specifically:
41#   Match @word:
42#         @...:
43#         @{section-name}:
44# while trying to not match literal block starts like "example::"
45#
46known_section_names = 'description|context|returns?|notes?|examples?'
47known_sections = KernRe(known_section_names, flags = re.I)
48doc_sect = doc_com + \
49    KernRe(r'\s*(@[.\w]+|@\.\.\.|' + known_section_names + r')\s*:([^:].*)?$',
50           flags=re.I, cache=False)
51
52doc_content = doc_com_body + KernRe(r'(.*)', cache=False)
53doc_inline_start = KernRe(r'^\s*/\*\*\s*$', cache=False)
54doc_inline_sect = KernRe(r'\s*\*\s*(@\s*[\w][\w\.]*\s*):(.*)', cache=False)
55doc_inline_end = KernRe(r'^\s*\*/\s*$', cache=False)
56doc_inline_oneline = KernRe(r'^\s*/\*\*\s*(@[\w\s]+):\s*(.*)\s*\*/\s*$', cache=False)
57
58export_symbol = KernRe(r'^\s*EXPORT_SYMBOL(_GPL)?\s*\(\s*(\w+)\s*\)\s*', cache=False)
59export_symbol_ns = KernRe(r'^\s*EXPORT_SYMBOL_NS(_GPL)?\s*\(\s*(\w+)\s*,\s*"\S+"\)\s*', cache=False)
60
61type_param = KernRe(r"@(\w*((\.\w+)|(->\w+))*(\.\.\.)?)", cache=False)
62
63#
64# Tests for the beginning of a kerneldoc block in its various forms.
65#
66doc_block = doc_com + KernRe(r'DOC:\s*(.*)?', cache=False)
67doc_begin_data = KernRe(r"^\s*\*?\s*(struct|union|enum|typedef)\b\s*(\w*)", cache = False)
68doc_begin_func = KernRe(str(doc_com) +			# initial " * '
69                        r"(?:\w+\s*\*\s*)?" + 		# type (not captured)
70                        r'(?:define\s+)?' + 		# possible "define" (not captured)
71                        r'(\w+)\s*(?:\(\w*\))?\s*' +	# name and optional "(...)"
72                        r'(?:[-:].*)?$',		# description (not captured)
73                        cache = False)
74
75#
76# Here begins a long set of transformations to turn structure member prefixes
77# and macro invocations into something we can parse and generate kdoc for.
78#
79struct_args_pattern = r'([^,)]+)'
80
81struct_xforms = [
82    # Strip attributes
83    (KernRe(r"__attribute__\s*\(\([a-z0-9,_\*\s\(\)]*\)\)", flags=re.I | re.S, cache=False), ' '),
84    (KernRe(r'\s*__aligned\s*\([^;]*\)', re.S), ' '),
85    (KernRe(r'\s*__counted_by\s*\([^;]*\)', re.S), ' '),
86    (KernRe(r'\s*__counted_by_(le|be)\s*\([^;]*\)', re.S), ' '),
87    (KernRe(r'\s*__packed\s*', re.S), ' '),
88    (KernRe(r'\s*CRYPTO_MINALIGN_ATTR', re.S), ' '),
89    (KernRe(r'\s*____cacheline_aligned_in_smp', re.S), ' '),
90    (KernRe(r'\s*____cacheline_aligned', re.S), ' '),
91    (KernRe(r'\s*__cacheline_group_(begin|end)\([^\)]+\);'), ''),
92    #
93    # Unwrap struct_group macros based on this definition:
94    # __struct_group(TAG, NAME, ATTRS, MEMBERS...)
95    # which has variants like: struct_group(NAME, MEMBERS...)
96    # Only MEMBERS arguments require documentation.
97    #
98    # Parsing them happens on two steps:
99    #
100    # 1. drop struct group arguments that aren't at MEMBERS,
101    #    storing them as STRUCT_GROUP(MEMBERS)
102    #
103    # 2. remove STRUCT_GROUP() ancillary macro.
104    #
105    # The original logic used to remove STRUCT_GROUP() using an
106    # advanced regex:
107    #
108    #   \bSTRUCT_GROUP(\(((?:(?>[^)(]+)|(?1))*)\))[^;]*;
109    #
110    # with two patterns that are incompatible with
111    # Python re module, as it has:
112    #
113    #   - a recursive pattern: (?1)
114    #   - an atomic grouping: (?>...)
115    #
116    # I tried a simpler version: but it didn't work either:
117    #   \bSTRUCT_GROUP\(([^\)]+)\)[^;]*;
118    #
119    # As it doesn't properly match the end parenthesis on some cases.
120    #
121    # So, a better solution was crafted: there's now a NestedMatch
122    # class that ensures that delimiters after a search are properly
123    # matched. So, the implementation to drop STRUCT_GROUP() will be
124    # handled in separate.
125    #
126    (KernRe(r'\bstruct_group\s*\(([^,]*,)', re.S), r'STRUCT_GROUP('),
127    (KernRe(r'\bstruct_group_attr\s*\(([^,]*,){2}', re.S), r'STRUCT_GROUP('),
128    (KernRe(r'\bstruct_group_tagged\s*\(([^,]*),([^,]*),', re.S), r'struct \1 \2; STRUCT_GROUP('),
129    (KernRe(r'\b__struct_group\s*\(([^,]*,){3}', re.S), r'STRUCT_GROUP('),
130    #
131    # Replace macros
132    #
133    # TODO: use NestedMatch for FOO($1, $2, ...) matches
134    #
135    # it is better to also move those to the NestedMatch logic,
136    # to ensure that parenthesis will be properly matched.
137    #
138    (KernRe(r'__ETHTOOL_DECLARE_LINK_MODE_MASK\s*\(([^\)]+)\)', re.S),
139     r'DECLARE_BITMAP(\1, __ETHTOOL_LINK_MODE_MASK_NBITS)'),
140    (KernRe(r'DECLARE_PHY_INTERFACE_MASK\s*\(([^\)]+)\)', re.S),
141     r'DECLARE_BITMAP(\1, PHY_INTERFACE_MODE_MAX)'),
142    (KernRe(r'DECLARE_BITMAP\s*\(' + struct_args_pattern + r',\s*' + struct_args_pattern + r'\)',
143            re.S), r'unsigned long \1[BITS_TO_LONGS(\2)]'),
144    (KernRe(r'DECLARE_HASHTABLE\s*\(' + struct_args_pattern + r',\s*' + struct_args_pattern + r'\)',
145            re.S), r'unsigned long \1[1 << ((\2) - 1)]'),
146    (KernRe(r'DECLARE_KFIFO\s*\(' + struct_args_pattern + r',\s*' + struct_args_pattern +
147            r',\s*' + struct_args_pattern + r'\)', re.S), r'\2 *\1'),
148    (KernRe(r'DECLARE_KFIFO_PTR\s*\(' + struct_args_pattern + r',\s*' +
149            struct_args_pattern + r'\)', re.S), r'\2 *\1'),
150    (KernRe(r'(?:__)?DECLARE_FLEX_ARRAY\s*\(' + struct_args_pattern + r',\s*' +
151            struct_args_pattern + r'\)', re.S), r'\1 \2[]'),
152    (KernRe(r'DEFINE_DMA_UNMAP_ADDR\s*\(' + struct_args_pattern + r'\)', re.S), r'dma_addr_t \1'),
153    (KernRe(r'DEFINE_DMA_UNMAP_LEN\s*\(' + struct_args_pattern + r'\)', re.S), r'__u32 \1'),
154]
155#
156# Regexes here are guaranteed to have the end limiter matching
157# the start delimiter. Yet, right now, only one replace group
158# is allowed.
159#
160struct_nested_prefixes = [
161    (re.compile(r'\bSTRUCT_GROUP\('), r'\1'),
162]
163
164#
165# Transforms for function prototypes
166#
167function_xforms  = [
168    (KernRe(r"^static +"), ""),
169    (KernRe(r"^extern +"), ""),
170    (KernRe(r"^asmlinkage +"), ""),
171    (KernRe(r"^inline +"), ""),
172    (KernRe(r"^__inline__ +"), ""),
173    (KernRe(r"^__inline +"), ""),
174    (KernRe(r"^__always_inline +"), ""),
175    (KernRe(r"^noinline +"), ""),
176    (KernRe(r"^__FORTIFY_INLINE +"), ""),
177    (KernRe(r"__init +"), ""),
178    (KernRe(r"__init_or_module +"), ""),
179    (KernRe(r"__deprecated +"), ""),
180    (KernRe(r"__flatten +"), ""),
181    (KernRe(r"__meminit +"), ""),
182    (KernRe(r"__must_check +"), ""),
183    (KernRe(r"__weak +"), ""),
184    (KernRe(r"__sched +"), ""),
185    (KernRe(r"_noprof"), ""),
186    (KernRe(r"__printf\s*\(\s*\d*\s*,\s*\d*\s*\) +"), ""),
187    (KernRe(r"__(?:re)?alloc_size\s*\(\s*\d+\s*(?:,\s*\d+\s*)?\) +"), ""),
188    (KernRe(r"__diagnose_as\s*\(\s*\S+\s*(?:,\s*\d+\s*)*\) +"), ""),
189    (KernRe(r"DECL_BUCKET_PARAMS\s*\(\s*(\S+)\s*,\s*(\S+)\s*\)"), r"\1, \2"),
190    (KernRe(r"__attribute_const__ +"), ""),
191    (KernRe(r"__attribute__\s*\(\((?:[\w\s]+(?:\([^)]*\))?\s*,?)+\)\)\s+"), ""),
192]
193
194#
195# Apply a set of transforms to a block of text.
196#
197def apply_transforms(xforms, text):
198    for search, subst in xforms:
199        text = search.sub(subst, text)
200    return text
201
202#
203# A little helper to get rid of excess white space
204#
205multi_space = KernRe(r'\s\s+')
206def trim_whitespace(s):
207    return multi_space.sub(' ', s.strip())
208
209#
210# Remove struct/enum members that have been marked "private".
211#
212def trim_private_members(text):
213    #
214    # First look for a "public:" block that ends a private region, then
215    # handle the "private until the end" case.
216    #
217    text = KernRe(r'/\*\s*private:.*?/\*\s*public:.*?\*/', flags=re.S).sub('', text)
218    text = KernRe(r'/\*\s*private:.*', flags=re.S).sub('', text)
219    #
220    # We needed the comments to do the above, but now we can take them out.
221    #
222    return KernRe(r'\s*/\*.*?\*/\s*', flags=re.S).sub('', text).strip()
223
224class state:
225    """
226    State machine enums
227    """
228
229    # Parser states
230    NORMAL        = 0        # normal code
231    NAME          = 1        # looking for function name
232    DECLARATION   = 2        # We have seen a declaration which might not be done
233    BODY          = 3        # the body of the comment
234    SPECIAL_SECTION = 4      # doc section ending with a blank line
235    PROTO         = 5        # scanning prototype
236    DOCBLOCK      = 6        # documentation block
237    INLINE_NAME   = 7        # gathering doc outside main block
238    INLINE_TEXT   = 8	     # reading the body of inline docs
239
240    name = [
241        "NORMAL",
242        "NAME",
243        "DECLARATION",
244        "BODY",
245        "SPECIAL_SECTION",
246        "PROTO",
247        "DOCBLOCK",
248        "INLINE_NAME",
249        "INLINE_TEXT",
250    ]
251
252
253SECTION_DEFAULT = "Description"  # default section
254
255class KernelEntry:
256
257    def __init__(self, config, ln):
258        self.config = config
259
260        self._contents = []
261        self.prototype = ""
262
263        self.warnings = []
264
265        self.parameterlist = []
266        self.parameterdescs = {}
267        self.parametertypes = {}
268        self.parameterdesc_start_lines = {}
269
270        self.section_start_lines = {}
271        self.sections = {}
272
273        self.anon_struct_union = False
274
275        self.leading_space = None
276
277        # State flags
278        self.brcount = 0
279        self.declaration_start_line = ln + 1
280
281    #
282    # Management of section contents
283    #
284    def add_text(self, text):
285        self._contents.append(text)
286
287    def contents(self):
288        return '\n'.join(self._contents) + '\n'
289
290    # TODO: rename to emit_message after removal of kernel-doc.pl
291    def emit_msg(self, log_msg, warning=True):
292        """Emit a message"""
293
294        if not warning:
295            self.config.log.info(log_msg)
296            return
297
298        # Delegate warning output to output logic, as this way it
299        # will report warnings/info only for symbols that are output
300
301        self.warnings.append(log_msg)
302        return
303
304    #
305    # Begin a new section.
306    #
307    def begin_section(self, line_no, title = SECTION_DEFAULT, dump = False):
308        if dump:
309            self.dump_section(start_new = True)
310        self.section = title
311        self.new_start_line = line_no
312
313    def dump_section(self, start_new=True):
314        """
315        Dumps section contents to arrays/hashes intended for that purpose.
316        """
317        #
318        # If we have accumulated no contents in the default ("description")
319        # section, don't bother.
320        #
321        if self.section == SECTION_DEFAULT and not self._contents:
322            return
323        name = self.section
324        contents = self.contents()
325
326        if type_param.match(name):
327            name = type_param.group(1)
328
329            self.parameterdescs[name] = contents
330            self.parameterdesc_start_lines[name] = self.new_start_line
331
332            self.new_start_line = 0
333
334        else:
335            if name in self.sections and self.sections[name] != "":
336                # Only warn on user-specified duplicate section names
337                if name != SECTION_DEFAULT:
338                    self.emit_msg(self.new_start_line,
339                                  f"duplicate section name '{name}'\n")
340                # Treat as a new paragraph - add a blank line
341                self.sections[name] += '\n' + contents
342            else:
343                self.sections[name] = contents
344                self.section_start_lines[name] = self.new_start_line
345                self.new_start_line = 0
346
347#        self.config.log.debug("Section: %s : %s", name, pformat(vars(self)))
348
349        if start_new:
350            self.section = SECTION_DEFAULT
351            self._contents = []
352
353
354class KernelDoc:
355    """
356    Read a C language source or header FILE and extract embedded
357    documentation comments.
358    """
359
360    # Section names
361
362    section_context = "Context"
363    section_return = "Return"
364
365    undescribed = "-- undescribed --"
366
367    def __init__(self, config, fname):
368        """Initialize internal variables"""
369
370        self.fname = fname
371        self.config = config
372
373        # Initial state for the state machines
374        self.state = state.NORMAL
375
376        # Store entry currently being processed
377        self.entry = None
378
379        # Place all potential outputs into an array
380        self.entries = []
381
382        #
383        # We need Python 3.7 for its "dicts remember the insertion
384        # order" guarantee
385        #
386        if sys.version_info.major == 3 and sys.version_info.minor < 7:
387            self.emit_msg(0,
388                          'Python 3.7 or later is required for correct results')
389
390    def emit_msg(self, ln, msg, warning=True):
391        """Emit a message"""
392
393        log_msg = f"{self.fname}:{ln} {msg}"
394
395        if self.entry:
396            self.entry.emit_msg(log_msg, warning)
397            return
398
399        if warning:
400            self.config.log.warning(log_msg)
401        else:
402            self.config.log.info(log_msg)
403
404    def dump_section(self, start_new=True):
405        """
406        Dumps section contents to arrays/hashes intended for that purpose.
407        """
408
409        if self.entry:
410            self.entry.dump_section(start_new)
411
412    # TODO: rename it to store_declaration after removal of kernel-doc.pl
413    def output_declaration(self, dtype, name, **args):
414        """
415        Stores the entry into an entry array.
416
417        The actual output and output filters will be handled elsewhere
418        """
419
420        item = KdocItem(name, dtype, self.entry.declaration_start_line, **args)
421        item.warnings = self.entry.warnings
422
423        # Drop empty sections
424        # TODO: improve empty sections logic to emit warnings
425        sections = self.entry.sections
426        for section in ["Description", "Return"]:
427            if section in sections and not sections[section].rstrip():
428                del sections[section]
429        item.set_sections(sections, self.entry.section_start_lines)
430        item.set_params(self.entry.parameterlist, self.entry.parameterdescs,
431                        self.entry.parametertypes,
432                        self.entry.parameterdesc_start_lines)
433        self.entries.append(item)
434
435        self.config.log.debug("Output: %s:%s = %s", dtype, name, pformat(args))
436
437    def reset_state(self, ln):
438        """
439        Ancillary routine to create a new entry. It initializes all
440        variables used by the state machine.
441        """
442
443        self.entry = KernelEntry(self.config, ln)
444
445        # State flags
446        self.state = state.NORMAL
447
448    def push_parameter(self, ln, decl_type, param, dtype,
449                       org_arg, declaration_name):
450        """
451        Store parameters and their descriptions at self.entry.
452        """
453
454        if self.entry.anon_struct_union and dtype == "" and param == "}":
455            return  # Ignore the ending }; from anonymous struct/union
456
457        self.entry.anon_struct_union = False
458
459        param = KernRe(r'[\[\)].*').sub('', param, count=1)
460
461        #
462        # Look at various "anonymous type" cases.
463        #
464        if dtype == '':
465            if param.endswith("..."):
466                if len(param) > 3: # there is a name provided, use that
467                    param = param[:-3]
468                if not self.entry.parameterdescs.get(param):
469                    self.entry.parameterdescs[param] = "variable arguments"
470
471            elif (not param) or param == "void":
472                param = "void"
473                self.entry.parameterdescs[param] = "no arguments"
474
475            elif param in ["struct", "union"]:
476                # Handle unnamed (anonymous) union or struct
477                dtype = param
478                param = "{unnamed_" + param + "}"
479                self.entry.parameterdescs[param] = "anonymous\n"
480                self.entry.anon_struct_union = True
481
482        # Warn if parameter has no description
483        # (but ignore ones starting with # as these are not parameters
484        # but inline preprocessor statements)
485        if param not in self.entry.parameterdescs and not param.startswith("#"):
486            self.entry.parameterdescs[param] = self.undescribed
487
488            if "." not in param:
489                if decl_type == 'function':
490                    dname = f"{decl_type} parameter"
491                else:
492                    dname = f"{decl_type} member"
493
494                self.emit_msg(ln,
495                              f"{dname} '{param}' not described in '{declaration_name}'")
496
497        # Strip spaces from param so that it is one continuous string on
498        # parameterlist. This fixes a problem where check_sections()
499        # cannot find a parameter like "addr[6 + 2]" because it actually
500        # appears as "addr[6", "+", "2]" on the parameter list.
501        # However, it's better to maintain the param string unchanged for
502        # output, so just weaken the string compare in check_sections()
503        # to ignore "[blah" in a parameter string.
504
505        self.entry.parameterlist.append(param)
506        org_arg = KernRe(r'\s\s+').sub(' ', org_arg)
507        self.entry.parametertypes[param] = org_arg
508
509
510    def create_parameter_list(self, ln, decl_type, args,
511                              splitter, declaration_name):
512        """
513        Creates a list of parameters, storing them at self.entry.
514        """
515
516        # temporarily replace all commas inside function pointer definition
517        arg_expr = KernRe(r'(\([^\),]+),')
518        while arg_expr.search(args):
519            args = arg_expr.sub(r"\1#", args)
520
521        for arg in args.split(splitter):
522            # Ignore argument attributes
523            arg = KernRe(r'\sPOS0?\s').sub(' ', arg)
524
525            # Strip leading/trailing spaces
526            arg = arg.strip()
527            arg = KernRe(r'\s+').sub(' ', arg, count=1)
528
529            if arg.startswith('#'):
530                # Treat preprocessor directive as a typeless variable just to fill
531                # corresponding data structures "correctly". Catch it later in
532                # output_* subs.
533
534                # Treat preprocessor directive as a typeless variable
535                self.push_parameter(ln, decl_type, arg, "",
536                                    "", declaration_name)
537            #
538            # The pointer-to-function case.
539            #
540            elif KernRe(r'\(.+\)\s*\(').search(arg):
541                arg = arg.replace('#', ',')
542                r = KernRe(r'[^\(]+\(\*?\s*'  # Everything up to "(*"
543                           r'([\w\[\].]*)'    # Capture the name and possible [array]
544                           r'\s*\)')	      # Make sure the trailing ")" is there
545                if r.match(arg):
546                    param = r.group(1)
547                else:
548                    self.emit_msg(ln, f"Invalid param: {arg}")
549                    param = arg
550                dtype = arg.replace(param, '')
551                self.push_parameter(ln, decl_type, param, dtype, arg, declaration_name)
552            #
553            # The array-of-pointers case.  Dig the parameter name out from the middle
554            # of the declaration.
555            #
556            elif KernRe(r'\(.+\)\s*\[').search(arg):
557                r = KernRe(r'[^\(]+\(\s*\*\s*'		# Up to "(" and maybe "*"
558                           r'([\w.]*?)'			# The actual pointer name
559                           r'\s*(\[\s*\w+\s*\]\s*)*\)') # The [array portion]
560                if r.match(arg):
561                    param = r.group(1)
562                else:
563                    self.emit_msg(ln, f"Invalid param: {arg}")
564                    param = arg
565                dtype = arg.replace(param, '')
566                self.push_parameter(ln, decl_type, param, dtype, arg, declaration_name)
567            elif arg:
568                #
569                # Clean up extraneous spaces and split the string at commas; the first
570                # element of the resulting list will also include the type information.
571                #
572                arg = KernRe(r'\s*:\s*').sub(":", arg)
573                arg = KernRe(r'\s*\[').sub('[', arg)
574                args = KernRe(r'\s*,\s*').split(arg)
575                args[0] = re.sub(r'(\*+)\s*', r' \1', args[0])
576                #
577                # args[0] has a string of "type a".  If "a" includes an [array]
578                # declaration, we want to not be fooled by any white space inside
579                # the brackets, so detect and handle that case specially.
580                #
581                r = KernRe(r'^([^[\]]*\s+)(.*)$')
582                if r.match(args[0]):
583                    args[0] = r.group(2)
584                    dtype = r.group(1)
585                else:
586                    # No space in args[0]; this seems wrong but preserves previous behavior
587                    dtype = ''
588
589                bitfield_re = KernRe(r'(.*?):(\w+)')
590                for param in args:
591                    #
592                    # For pointers, shift the star(s) from the variable name to the
593                    # type declaration.
594                    #
595                    r = KernRe(r'^(\*+)\s*(.*)')
596                    if r.match(param):
597                        self.push_parameter(ln, decl_type, r.group(2),
598                                            f"{dtype} {r.group(1)}",
599                                            arg, declaration_name)
600                    #
601                    # Perform a similar shift for bitfields.
602                    #
603                    elif bitfield_re.search(param):
604                        if dtype != "":  # Skip unnamed bit-fields
605                            self.push_parameter(ln, decl_type, bitfield_re.group(1),
606                                                f"{dtype}:{bitfield_re.group(2)}",
607                                                arg, declaration_name)
608                    else:
609                        self.push_parameter(ln, decl_type, param, dtype,
610                                            arg, declaration_name)
611
612    def check_sections(self, ln, decl_name, decl_type):
613        """
614        Check for errors inside sections, emitting warnings if not found
615        parameters are described.
616        """
617        for section in self.entry.sections:
618            if section not in self.entry.parameterlist and \
619               not known_sections.search(section):
620                if decl_type == 'function':
621                    dname = f"{decl_type} parameter"
622                else:
623                    dname = f"{decl_type} member"
624                self.emit_msg(ln,
625                              f"Excess {dname} '{section}' description in '{decl_name}'")
626
627    def check_return_section(self, ln, declaration_name, return_type):
628        """
629        If the function doesn't return void, warns about the lack of a
630        return description.
631        """
632
633        if not self.config.wreturn:
634            return
635
636        # Ignore an empty return type (It's a macro)
637        # Ignore functions with a "void" return type (but not "void *")
638        if not return_type or KernRe(r'void\s*\w*\s*$').search(return_type):
639            return
640
641        if not self.entry.sections.get("Return", None):
642            self.emit_msg(ln,
643                          f"No description found for return value of '{declaration_name}'")
644
645    #
646    # Split apart a structure prototype; returns (struct|union, name, members) or None
647    #
648    def split_struct_proto(self, proto):
649        type_pattern = r'(struct|union)'
650        qualifiers = [
651            "__attribute__",
652            "__packed",
653            "__aligned",
654            "____cacheline_aligned_in_smp",
655            "____cacheline_aligned",
656        ]
657        definition_body = r'\{(.*)\}\s*' + "(?:" + '|'.join(qualifiers) + ")?"
658
659        r = KernRe(type_pattern + r'\s+(\w+)\s*' + definition_body)
660        if r.search(proto):
661            return (r.group(1), r.group(2), r.group(3))
662        else:
663            r = KernRe(r'typedef\s+' + type_pattern + r'\s*' + definition_body + r'\s*(\w+)\s*;')
664            if r.search(proto):
665                return (r.group(1), r.group(3), r.group(2))
666        return None
667    #
668    # Rewrite the members of a structure or union for easier formatting later on.
669    # Among other things, this function will turn a member like:
670    #
671    #  struct { inner_members; } foo;
672    #
673    # into:
674    #
675    #  struct foo; inner_members;
676    #
677    def rewrite_struct_members(self, members):
678        #
679        # Process struct/union members from the most deeply nested outward.  The
680        # trick is in the ^{ below - it prevents a match of an outer struct/union
681        # until the inner one has been munged (removing the "{" in the process).
682        #
683        struct_members = KernRe(r'(struct|union)'   # 0: declaration type
684                                r'([^\{\};]+)' 	    # 1: possible name
685                                r'(\{)'
686                                r'([^\{\}]*)'       # 3: Contents of declaration
687                                r'(\})'
688                                r'([^\{\};]*)(;)')  # 5: Remaining stuff after declaration
689        tuples = struct_members.findall(members)
690        while tuples:
691            for t in tuples:
692                newmember = ""
693                oldmember = "".join(t) # Reconstruct the original formatting
694                dtype, name, lbr, content, rbr, rest, semi = t
695                #
696                # Pass through each field name, normalizing the form and formatting.
697                #
698                for s_id in rest.split(','):
699                    s_id = s_id.strip()
700                    newmember += f"{dtype} {s_id}; "
701                    #
702                    # Remove bitfield/array/pointer info, getting the bare name.
703                    #
704                    s_id = KernRe(r'[:\[].*').sub('', s_id)
705                    s_id = KernRe(r'^\s*\**(\S+)\s*').sub(r'\1', s_id)
706                    #
707                    # Pass through the members of this inner structure/union.
708                    #
709                    for arg in content.split(';'):
710                        arg = arg.strip()
711                        #
712                        # Look for (type)(*name)(args) - pointer to function
713                        #
714                        r = KernRe(r'^([^\(]+\(\*?\s*)([\w.]*)(\s*\).*)')
715                        if r.match(arg):
716                            dtype, name, extra = r.group(1), r.group(2), r.group(3)
717                            # Pointer-to-function
718                            if not s_id:
719                                # Anonymous struct/union
720                                newmember += f"{dtype}{name}{extra}; "
721                            else:
722                                newmember += f"{dtype}{s_id}.{name}{extra}; "
723                        #
724                        # Otherwise a non-function member.
725                        #
726                        else:
727                            #
728                            # Remove bitmap and array portions and spaces around commas
729                            #
730                            arg = KernRe(r':\s*\d+\s*').sub('', arg)
731                            arg = KernRe(r'\[.*\]').sub('', arg)
732                            arg = KernRe(r'\s*,\s*').sub(',', arg)
733                            #
734                            # Look for a normal decl - "type name[,name...]"
735                            #
736                            r = KernRe(r'(.*)\s+([\S+,]+)')
737                            if r.search(arg):
738                                for name in r.group(2).split(','):
739                                    name = KernRe(r'^\s*\**(\S+)\s*').sub(r'\1', name)
740                                    if not s_id:
741                                        # Anonymous struct/union
742                                        newmember += f"{r.group(1)} {name}; "
743                                    else:
744                                        newmember += f"{r.group(1)} {s_id}.{name}; "
745                            else:
746                                newmember += f"{arg}; "
747                #
748                # At the end of the s_id loop, replace the original declaration with
749                # the munged version.
750                #
751                members = members.replace(oldmember, newmember)
752            #
753            # End of the tuple loop - search again and see if there are outer members
754            # that now turn up.
755            #
756            tuples = struct_members.findall(members)
757        return members
758
759    #
760    # Format the struct declaration into a standard form for inclusion in the
761    # resulting docs.
762    #
763    def format_struct_decl(self, declaration):
764        #
765        # Insert newlines, get rid of extra spaces.
766        #
767        declaration = KernRe(r'([\{;])').sub(r'\1\n', declaration)
768        declaration = KernRe(r'\}\s+;').sub('};', declaration)
769        #
770        # Format inline enums with each member on its own line.
771        #
772        r = KernRe(r'(enum\s+\{[^\}]+),([^\n])')
773        while r.search(declaration):
774            declaration = r.sub(r'\1,\n\2', declaration)
775        #
776        # Now go through and supply the right number of tabs
777        # for each line.
778        #
779        def_args = declaration.split('\n')
780        level = 1
781        declaration = ""
782        for clause in def_args:
783            clause = KernRe(r'\s+').sub(' ', clause.strip(), count=1)
784            if clause:
785                if '}' in clause and level > 1:
786                    level -= 1
787                if not clause.startswith('#'):
788                    declaration += "\t" * level
789                declaration += "\t" + clause + "\n"
790                if "{" in clause and "}" not in clause:
791                    level += 1
792        return declaration
793
794
795    def dump_struct(self, ln, proto):
796        """
797        Store an entry for an struct or union
798        """
799        #
800        # Do the basic parse to get the pieces of the declaration.
801        #
802        struct_parts = self.split_struct_proto(proto)
803        if not struct_parts:
804            self.emit_msg(ln, f"{proto} error: Cannot parse struct or union!")
805            return
806        decl_type, declaration_name, members = struct_parts
807
808        if self.entry.identifier != declaration_name:
809            self.emit_msg(ln, f"expecting prototype for {decl_type} {self.entry.identifier}. "
810                          f"Prototype was for {decl_type} {declaration_name} instead\n")
811            return
812        #
813        # Go through the list of members applying all of our transformations.
814        #
815        members = trim_private_members(members)
816        members = apply_transforms(struct_xforms, members)
817
818        nested = NestedMatch()
819        for search, sub in struct_nested_prefixes:
820            members = nested.sub(search, sub, members)
821        #
822        # Deal with embedded struct and union members, and drop enums entirely.
823        #
824        declaration = members
825        members = self.rewrite_struct_members(members)
826        members = re.sub(r'(\{[^\{\}]*\})', '', members)
827        #
828        # Output the result and we are done.
829        #
830        self.create_parameter_list(ln, decl_type, members, ';',
831                                   declaration_name)
832        self.check_sections(ln, declaration_name, decl_type)
833        self.output_declaration(decl_type, declaration_name,
834                                definition=self.format_struct_decl(declaration),
835                                purpose=self.entry.declaration_purpose)
836
837    def dump_enum(self, ln, proto):
838        """
839        Stores an enum inside self.entries array.
840        """
841        #
842        # Strip preprocessor directives.  Note that this depends on the
843        # trailing semicolon we added in process_proto_type().
844        #
845        proto = KernRe(r'#\s*((define|ifdef|if)\s+|endif)[^;]*;', flags=re.S).sub('', proto)
846        #
847        # Parse out the name and members of the enum.  Typedef form first.
848        #
849        r = KernRe(r'typedef\s+enum\s*\{(.*)\}\s*(\w*)\s*;')
850        if r.search(proto):
851            declaration_name = r.group(2)
852            members = trim_private_members(r.group(1))
853        #
854        # Failing that, look for a straight enum
855        #
856        else:
857            r = KernRe(r'enum\s+(\w*)\s*\{(.*)\}')
858            if r.match(proto):
859                declaration_name = r.group(1)
860                members = trim_private_members(r.group(2))
861        #
862        # OK, this isn't going to work.
863        #
864            else:
865                self.emit_msg(ln, f"{proto}: error: Cannot parse enum!")
866                return
867        #
868        # Make sure we found what we were expecting.
869        #
870        if self.entry.identifier != declaration_name:
871            if self.entry.identifier == "":
872                self.emit_msg(ln,
873                              f"{proto}: wrong kernel-doc identifier on prototype")
874            else:
875                self.emit_msg(ln,
876                              f"expecting prototype for enum {self.entry.identifier}. "
877                              f"Prototype was for enum {declaration_name} instead")
878            return
879
880        if not declaration_name:
881            declaration_name = "(anonymous)"
882        #
883        # Parse out the name of each enum member, and verify that we
884        # have a description for it.
885        #
886        member_set = set()
887        members = KernRe(r'\([^;)]*\)').sub('', members)
888        for arg in members.split(','):
889            if not arg:
890                continue
891            arg = KernRe(r'^\s*(\w+).*').sub(r'\1', arg)
892            self.entry.parameterlist.append(arg)
893            if arg not in self.entry.parameterdescs:
894                self.entry.parameterdescs[arg] = self.undescribed
895                self.emit_msg(ln,
896                              f"Enum value '{arg}' not described in enum '{declaration_name}'")
897            member_set.add(arg)
898        #
899        # Ensure that every described member actually exists in the enum.
900        #
901        for k in self.entry.parameterdescs:
902            if k not in member_set:
903                self.emit_msg(ln,
904                              f"Excess enum value '%{k}' description in '{declaration_name}'")
905
906        self.output_declaration('enum', declaration_name,
907                                purpose=self.entry.declaration_purpose)
908
909    def dump_declaration(self, ln, prototype):
910        """
911        Stores a data declaration inside self.entries array.
912        """
913
914        if self.entry.decl_type == "enum":
915            self.dump_enum(ln, prototype)
916        elif self.entry.decl_type == "typedef":
917            self.dump_typedef(ln, prototype)
918        elif self.entry.decl_type in ["union", "struct"]:
919            self.dump_struct(ln, prototype)
920        else:
921            # This would be a bug
922            self.emit_message(ln, f'Unknown declaration type: {self.entry.decl_type}')
923
924    def dump_function(self, ln, prototype):
925        """
926        Stores a function of function macro inside self.entries array.
927        """
928
929        found = func_macro = False
930        return_type = ''
931        decl_type = 'function'
932        #
933        # Apply the initial transformations.
934        #
935        prototype = apply_transforms(function_xforms, prototype)
936        #
937        # If we have a macro, remove the "#define" at the front.
938        #
939        new_proto = KernRe(r"^#\s*define\s+").sub("", prototype)
940        if new_proto != prototype:
941            prototype = new_proto
942            #
943            # Dispense with the simple "#define A B" case here; the key
944            # is the space after the name of the symbol being defined.
945            # NOTE that the seemingly misnamed "func_macro" indicates a
946            # macro *without* arguments.
947            #
948            r = KernRe(r'^(\w+)\s+')
949            if r.search(prototype):
950                return_type = ''
951                declaration_name = r.group(1)
952                func_macro = True
953                found = True
954
955        # Yes, this truly is vile.  We are looking for:
956        # 1. Return type (may be nothing if we're looking at a macro)
957        # 2. Function name
958        # 3. Function parameters.
959        #
960        # All the while we have to watch out for function pointer parameters
961        # (which IIRC is what the two sections are for), C types (these
962        # regexps don't even start to express all the possibilities), and
963        # so on.
964        #
965        # If you mess with these regexps, it's a good idea to check that
966        # the following functions' documentation still comes out right:
967        # - parport_register_device (function pointer parameters)
968        # - atomic_set (macro)
969        # - pci_match_device, __copy_to_user (long return type)
970
971        name = r'\w+'
972        type1 = r'(?:[\w\s]+)?'
973        type2 = r'(?:[\w\s]+\*+)+'
974        #
975        # Attempt to match first on (args) with no internal parentheses; this
976        # lets us easily filter out __acquires() and other post-args stuff.  If
977        # that fails, just grab the rest of the line to the last closing
978        # parenthesis.
979        #
980        proto_args = r'\(([^\(]*|.*)\)'
981        #
982        # (Except for the simple macro case) attempt to split up the prototype
983        # in the various ways we understand.
984        #
985        if not found:
986            patterns = [
987                rf'^()({name})\s*{proto_args}',
988                rf'^({type1})\s+({name})\s*{proto_args}',
989                rf'^({type2})\s*({name})\s*{proto_args}',
990            ]
991
992            for p in patterns:
993                r = KernRe(p)
994                if r.match(prototype):
995                    return_type = r.group(1)
996                    declaration_name = r.group(2)
997                    args = r.group(3)
998                    self.create_parameter_list(ln, decl_type, args, ',',
999                                               declaration_name)
1000                    found = True
1001                    break
1002        #
1003        # Parsing done; make sure that things are as we expect.
1004        #
1005        if not found:
1006            self.emit_msg(ln,
1007                          f"cannot understand function prototype: '{prototype}'")
1008            return
1009        if self.entry.identifier != declaration_name:
1010            self.emit_msg(ln, f"expecting prototype for {self.entry.identifier}(). "
1011                          f"Prototype was for {declaration_name}() instead")
1012            return
1013        self.check_sections(ln, declaration_name, "function")
1014        self.check_return_section(ln, declaration_name, return_type)
1015        #
1016        # Store the result.
1017        #
1018        self.output_declaration(decl_type, declaration_name,
1019                                typedef=('typedef' in return_type),
1020                                functiontype=return_type,
1021                                purpose=self.entry.declaration_purpose,
1022                                func_macro=func_macro)
1023
1024
1025    def dump_typedef(self, ln, proto):
1026        """
1027        Stores a typedef inside self.entries array.
1028        """
1029        #
1030        # We start by looking for function typedefs.
1031        #
1032        typedef_type = r'typedef((?:\s+[\w*]+\b){0,7}\s+(?:\w+\b|\*+))\s*'
1033        typedef_ident = r'\*?\s*(\w\S+)\s*'
1034        typedef_args = r'\s*\((.*)\);'
1035
1036        typedef1 = KernRe(typedef_type + r'\(' + typedef_ident + r'\)' + typedef_args)
1037        typedef2 = KernRe(typedef_type + typedef_ident + typedef_args)
1038
1039        # Parse function typedef prototypes
1040        for r in [typedef1, typedef2]:
1041            if not r.match(proto):
1042                continue
1043
1044            return_type = r.group(1).strip()
1045            declaration_name = r.group(2)
1046            args = r.group(3)
1047
1048            if self.entry.identifier != declaration_name:
1049                self.emit_msg(ln,
1050                              f"expecting prototype for typedef {self.entry.identifier}. Prototype was for typedef {declaration_name} instead\n")
1051                return
1052
1053            self.create_parameter_list(ln, 'function', args, ',', declaration_name)
1054
1055            self.output_declaration('function', declaration_name,
1056                                    typedef=True,
1057                                    functiontype=return_type,
1058                                    purpose=self.entry.declaration_purpose)
1059            return
1060        #
1061        # Not a function, try to parse a simple typedef.
1062        #
1063        r = KernRe(r'typedef.*\s+(\w+)\s*;')
1064        if r.match(proto):
1065            declaration_name = r.group(1)
1066
1067            if self.entry.identifier != declaration_name:
1068                self.emit_msg(ln,
1069                              f"expecting prototype for typedef {self.entry.identifier}. Prototype was for typedef {declaration_name} instead\n")
1070                return
1071
1072            self.output_declaration('typedef', declaration_name,
1073                                    purpose=self.entry.declaration_purpose)
1074            return
1075
1076        self.emit_msg(ln, "error: Cannot parse typedef!")
1077
1078    @staticmethod
1079    def process_export(function_set, line):
1080        """
1081        process EXPORT_SYMBOL* tags
1082
1083        This method doesn't use any variable from the class, so declare it
1084        with a staticmethod decorator.
1085        """
1086
1087        # We support documenting some exported symbols with different
1088        # names.  A horrible hack.
1089        suffixes = [ '_noprof' ]
1090
1091        # Note: it accepts only one EXPORT_SYMBOL* per line, as having
1092        # multiple export lines would violate Kernel coding style.
1093
1094        if export_symbol.search(line):
1095            symbol = export_symbol.group(2)
1096        elif export_symbol_ns.search(line):
1097            symbol = export_symbol_ns.group(2)
1098        else:
1099            return False
1100        #
1101        # Found an export, trim out any special suffixes
1102        #
1103        for suffix in suffixes:
1104            # Be backward compatible with Python < 3.9
1105            if symbol.endswith(suffix):
1106                symbol = symbol[:-len(suffix)]
1107        function_set.add(symbol)
1108        return True
1109
1110    def process_normal(self, ln, line):
1111        """
1112        STATE_NORMAL: looking for the /** to begin everything.
1113        """
1114
1115        if not doc_start.match(line):
1116            return
1117
1118        # start a new entry
1119        self.reset_state(ln)
1120
1121        # next line is always the function name
1122        self.state = state.NAME
1123
1124    def process_name(self, ln, line):
1125        """
1126        STATE_NAME: Looking for the "name - description" line
1127        """
1128        #
1129        # Check for a DOC: block and handle them specially.
1130        #
1131        if doc_block.search(line):
1132
1133            if not doc_block.group(1):
1134                self.entry.begin_section(ln, "Introduction")
1135            else:
1136                self.entry.begin_section(ln, doc_block.group(1))
1137
1138            self.entry.identifier = self.entry.section
1139            self.state = state.DOCBLOCK
1140        #
1141        # Otherwise we're looking for a normal kerneldoc declaration line.
1142        #
1143        elif doc_decl.search(line):
1144            self.entry.identifier = doc_decl.group(1)
1145
1146            # Test for data declaration
1147            if doc_begin_data.search(line):
1148                self.entry.decl_type = doc_begin_data.group(1)
1149                self.entry.identifier = doc_begin_data.group(2)
1150            #
1151            # Look for a function description
1152            #
1153            elif doc_begin_func.search(line):
1154                self.entry.identifier = doc_begin_func.group(1)
1155                self.entry.decl_type = "function"
1156            #
1157            # We struck out.
1158            #
1159            else:
1160                self.emit_msg(ln,
1161                              f"This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst\n{line}")
1162                self.state = state.NORMAL
1163                return
1164            #
1165            # OK, set up for a new kerneldoc entry.
1166            #
1167            self.state = state.BODY
1168            self.entry.identifier = self.entry.identifier.strip(" ")
1169            # if there's no @param blocks need to set up default section here
1170            self.entry.begin_section(ln + 1)
1171            #
1172            # Find the description portion, which *should* be there but
1173            # isn't always.
1174            # (We should be able to capture this from the previous parsing - someday)
1175            #
1176            r = KernRe("[-:](.*)")
1177            if r.search(line):
1178                self.entry.declaration_purpose = trim_whitespace(r.group(1))
1179                self.state = state.DECLARATION
1180            else:
1181                self.entry.declaration_purpose = ""
1182
1183            if not self.entry.declaration_purpose and self.config.wshort_desc:
1184                self.emit_msg(ln,
1185                              f"missing initial short description on line:\n{line}")
1186
1187            if not self.entry.identifier and self.entry.decl_type != "enum":
1188                self.emit_msg(ln,
1189                              f"wrong kernel-doc identifier on line:\n{line}")
1190                self.state = state.NORMAL
1191
1192            if self.config.verbose:
1193                self.emit_msg(ln,
1194                              f"Scanning doc for {self.entry.decl_type} {self.entry.identifier}",
1195                                  warning=False)
1196        #
1197        # Failed to find an identifier. Emit a warning
1198        #
1199        else:
1200            self.emit_msg(ln, f"Cannot find identifier on line:\n{line}")
1201
1202    #
1203    # Helper function to determine if a new section is being started.
1204    #
1205    def is_new_section(self, ln, line):
1206        if doc_sect.search(line):
1207            self.state = state.BODY
1208            #
1209            # Pick out the name of our new section, tweaking it if need be.
1210            #
1211            newsection = doc_sect.group(1)
1212            if newsection.lower() == 'description':
1213                newsection = 'Description'
1214            elif newsection.lower() == 'context':
1215                newsection = 'Context'
1216                self.state = state.SPECIAL_SECTION
1217            elif newsection.lower() in ["@return", "@returns",
1218                                        "return", "returns"]:
1219                newsection = "Return"
1220                self.state = state.SPECIAL_SECTION
1221            elif newsection[0] == '@':
1222                self.state = state.SPECIAL_SECTION
1223            #
1224            # Initialize the contents, and get the new section going.
1225            #
1226            newcontents = doc_sect.group(2)
1227            if not newcontents:
1228                newcontents = ""
1229            self.dump_section()
1230            self.entry.begin_section(ln, newsection)
1231            self.entry.leading_space = None
1232
1233            self.entry.add_text(newcontents.lstrip())
1234            return True
1235        return False
1236
1237    #
1238    # Helper function to detect (and effect) the end of a kerneldoc comment.
1239    #
1240    def is_comment_end(self, ln, line):
1241        if doc_end.search(line):
1242            self.dump_section()
1243
1244            # Look for doc_com + <text> + doc_end:
1245            r = KernRe(r'\s*\*\s*[a-zA-Z_0-9:.]+\*/')
1246            if r.match(line):
1247                self.emit_msg(ln, f"suspicious ending line: {line}")
1248
1249            self.entry.prototype = ""
1250            self.entry.new_start_line = ln + 1
1251
1252            self.state = state.PROTO
1253            return True
1254        return False
1255
1256
1257    def process_decl(self, ln, line):
1258        """
1259        STATE_DECLARATION: We've seen the beginning of a declaration
1260        """
1261        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
1262            return
1263        #
1264        # Look for anything with the " * " line beginning.
1265        #
1266        if doc_content.search(line):
1267            cont = doc_content.group(1)
1268            #
1269            # A blank line means that we have moved out of the declaration
1270            # part of the comment (without any "special section" parameter
1271            # descriptions).
1272            #
1273            if cont == "":
1274                self.state = state.BODY
1275            #
1276            # Otherwise we have more of the declaration section to soak up.
1277            #
1278            else:
1279                self.entry.declaration_purpose = \
1280                    trim_whitespace(self.entry.declaration_purpose + ' ' + cont)
1281        else:
1282            # Unknown line, ignore
1283            self.emit_msg(ln, f"bad line: {line}")
1284
1285
1286    def process_special(self, ln, line):
1287        """
1288        STATE_SPECIAL_SECTION: a section ending with a blank line
1289        """
1290        #
1291        # If we have hit a blank line (only the " * " marker), then this
1292        # section is done.
1293        #
1294        if KernRe(r"\s*\*\s*$").match(line):
1295            self.entry.begin_section(ln, dump = True)
1296            self.state = state.BODY
1297            return
1298        #
1299        # Not a blank line, look for the other ways to end the section.
1300        #
1301        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
1302            return
1303        #
1304        # OK, we should have a continuation of the text for this section.
1305        #
1306        if doc_content.search(line):
1307            cont = doc_content.group(1)
1308            #
1309            # If the lines of text after the first in a special section have
1310            # leading white space, we need to trim it out or Sphinx will get
1311            # confused.  For the second line (the None case), see what we
1312            # find there and remember it.
1313            #
1314            if self.entry.leading_space is None:
1315                r = KernRe(r'^(\s+)')
1316                if r.match(cont):
1317                    self.entry.leading_space = len(r.group(1))
1318                else:
1319                    self.entry.leading_space = 0
1320            #
1321            # Otherwise, before trimming any leading chars, be *sure*
1322            # that they are white space.  We should maybe warn if this
1323            # isn't the case.
1324            #
1325            for i in range(0, self.entry.leading_space):
1326                if cont[i] != " ":
1327                    self.entry.leading_space = i
1328                    break
1329            #
1330            # Add the trimmed result to the section and we're done.
1331            #
1332            self.entry.add_text(cont[self.entry.leading_space:])
1333        else:
1334            # Unknown line, ignore
1335            self.emit_msg(ln, f"bad line: {line}")
1336
1337    def process_body(self, ln, line):
1338        """
1339        STATE_BODY: the bulk of a kerneldoc comment.
1340        """
1341        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
1342            return
1343
1344        if doc_content.search(line):
1345            cont = doc_content.group(1)
1346            self.entry.add_text(cont)
1347        else:
1348            # Unknown line, ignore
1349            self.emit_msg(ln, f"bad line: {line}")
1350
1351    def process_inline_name(self, ln, line):
1352        """STATE_INLINE_NAME: beginning of docbook comments within a prototype."""
1353
1354        if doc_inline_sect.search(line):
1355            self.entry.begin_section(ln, doc_inline_sect.group(1))
1356            self.entry.add_text(doc_inline_sect.group(2).lstrip())
1357            self.state = state.INLINE_TEXT
1358        elif doc_inline_end.search(line):
1359            self.dump_section()
1360            self.state = state.PROTO
1361        elif doc_content.search(line):
1362            self.emit_msg(ln, f"Incorrect use of kernel-doc format: {line}")
1363            self.state = state.PROTO
1364        # else ... ??
1365
1366    def process_inline_text(self, ln, line):
1367        """STATE_INLINE_TEXT: docbook comments within a prototype."""
1368
1369        if doc_inline_end.search(line):
1370            self.dump_section()
1371            self.state = state.PROTO
1372        elif doc_content.search(line):
1373            self.entry.add_text(doc_content.group(1))
1374        # else ... ??
1375
1376    def syscall_munge(self, ln, proto):         # pylint: disable=W0613
1377        """
1378        Handle syscall definitions
1379        """
1380
1381        is_void = False
1382
1383        # Strip newlines/CR's
1384        proto = re.sub(r'[\r\n]+', ' ', proto)
1385
1386        # Check if it's a SYSCALL_DEFINE0
1387        if 'SYSCALL_DEFINE0' in proto:
1388            is_void = True
1389
1390        # Replace SYSCALL_DEFINE with correct return type & function name
1391        proto = KernRe(r'SYSCALL_DEFINE.*\(').sub('long sys_', proto)
1392
1393        r = KernRe(r'long\s+(sys_.*?),')
1394        if r.search(proto):
1395            proto = KernRe(',').sub('(', proto, count=1)
1396        elif is_void:
1397            proto = KernRe(r'\)').sub('(void)', proto, count=1)
1398
1399        # Now delete all of the odd-numbered commas in the proto
1400        # so that argument types & names don't have a comma between them
1401        count = 0
1402        length = len(proto)
1403
1404        if is_void:
1405            length = 0  # skip the loop if is_void
1406
1407        for ix in range(length):
1408            if proto[ix] == ',':
1409                count += 1
1410                if count % 2 == 1:
1411                    proto = proto[:ix] + ' ' + proto[ix + 1:]
1412
1413        return proto
1414
1415    def tracepoint_munge(self, ln, proto):
1416        """
1417        Handle tracepoint definitions
1418        """
1419
1420        tracepointname = None
1421        tracepointargs = None
1422
1423        # Match tracepoint name based on different patterns
1424        r = KernRe(r'TRACE_EVENT\((.*?),')
1425        if r.search(proto):
1426            tracepointname = r.group(1)
1427
1428        r = KernRe(r'DEFINE_SINGLE_EVENT\((.*?),')
1429        if r.search(proto):
1430            tracepointname = r.group(1)
1431
1432        r = KernRe(r'DEFINE_EVENT\((.*?),(.*?),')
1433        if r.search(proto):
1434            tracepointname = r.group(2)
1435
1436        if tracepointname:
1437            tracepointname = tracepointname.lstrip()
1438
1439        r = KernRe(r'TP_PROTO\((.*?)\)')
1440        if r.search(proto):
1441            tracepointargs = r.group(1)
1442
1443        if not tracepointname or not tracepointargs:
1444            self.emit_msg(ln,
1445                          f"Unrecognized tracepoint format:\n{proto}\n")
1446        else:
1447            proto = f"static inline void trace_{tracepointname}({tracepointargs})"
1448            self.entry.identifier = f"trace_{self.entry.identifier}"
1449
1450        return proto
1451
1452    def process_proto_function(self, ln, line):
1453        """Ancillary routine to process a function prototype"""
1454
1455        # strip C99-style comments to end of line
1456        line = KernRe(r"//.*$", re.S).sub('', line)
1457        #
1458        # Soak up the line's worth of prototype text, stopping at { or ; if present.
1459        #
1460        if KernRe(r'\s*#\s*define').match(line):
1461            self.entry.prototype = line
1462        elif not line.startswith('#'):   # skip other preprocessor stuff
1463            r = KernRe(r'([^\{]*)')
1464            if r.match(line):
1465                self.entry.prototype += r.group(1) + " "
1466        #
1467        # If we now have the whole prototype, clean it up and declare victory.
1468        #
1469        if '{' in line or ';' in line or KernRe(r'\s*#\s*define').match(line):
1470            # strip comments and surrounding spaces
1471            self.entry.prototype = KernRe(r'/\*.*\*/').sub('', self.entry.prototype).strip()
1472            #
1473            # Handle self.entry.prototypes for function pointers like:
1474            #       int (*pcs_config)(struct foo)
1475            # by turning it into
1476            #	    int pcs_config(struct foo)
1477            #
1478            r = KernRe(r'^(\S+\s+)\(\s*\*(\S+)\)')
1479            self.entry.prototype = r.sub(r'\1\2', self.entry.prototype)
1480            #
1481            # Handle special declaration syntaxes
1482            #
1483            if 'SYSCALL_DEFINE' in self.entry.prototype:
1484                self.entry.prototype = self.syscall_munge(ln,
1485                                                          self.entry.prototype)
1486            else:
1487                r = KernRe(r'TRACE_EVENT|DEFINE_EVENT|DEFINE_SINGLE_EVENT')
1488                if r.search(self.entry.prototype):
1489                    self.entry.prototype = self.tracepoint_munge(ln,
1490                                                                 self.entry.prototype)
1491            #
1492            # ... and we're done
1493            #
1494            self.dump_function(ln, self.entry.prototype)
1495            self.reset_state(ln)
1496
1497    def process_proto_type(self, ln, line):
1498        """Ancillary routine to process a type"""
1499
1500        # Strip C99-style comments and surrounding whitespace
1501        line = KernRe(r"//.*$", re.S).sub('', line).strip()
1502        if not line:
1503            return # nothing to see here
1504
1505        # To distinguish preprocessor directive from regular declaration later.
1506        if line.startswith('#'):
1507            line += ";"
1508        #
1509        # Split the declaration on any of { } or ;, and accumulate pieces
1510        # until we hit a semicolon while not inside {brackets}
1511        #
1512        r = KernRe(r'(.*?)([{};])')
1513        for chunk in r.split(line):
1514            if chunk:  # Ignore empty matches
1515                self.entry.prototype += chunk
1516                #
1517                # This cries out for a match statement ... someday after we can
1518                # drop Python 3.9 ...
1519                #
1520                if chunk == '{':
1521                    self.entry.brcount += 1
1522                elif chunk == '}':
1523                    self.entry.brcount -= 1
1524                elif chunk == ';' and self.entry.brcount <= 0:
1525                    self.dump_declaration(ln, self.entry.prototype)
1526                    self.reset_state(ln)
1527                    return
1528        #
1529        # We hit the end of the line while still in the declaration; put
1530        # in a space to represent the newline.
1531        #
1532        self.entry.prototype += ' '
1533
1534    def process_proto(self, ln, line):
1535        """STATE_PROTO: reading a function/whatever prototype."""
1536
1537        if doc_inline_oneline.search(line):
1538            self.entry.begin_section(ln, doc_inline_oneline.group(1))
1539            self.entry.add_text(doc_inline_oneline.group(2))
1540            self.dump_section()
1541
1542        elif doc_inline_start.search(line):
1543            self.state = state.INLINE_NAME
1544
1545        elif self.entry.decl_type == 'function':
1546            self.process_proto_function(ln, line)
1547
1548        else:
1549            self.process_proto_type(ln, line)
1550
1551    def process_docblock(self, ln, line):
1552        """STATE_DOCBLOCK: within a DOC: block."""
1553
1554        if doc_end.search(line):
1555            self.dump_section()
1556            self.output_declaration("doc", self.entry.identifier)
1557            self.reset_state(ln)
1558
1559        elif doc_content.search(line):
1560            self.entry.add_text(doc_content.group(1))
1561
1562    def parse_export(self):
1563        """
1564        Parses EXPORT_SYMBOL* macros from a single Kernel source file.
1565        """
1566
1567        export_table = set()
1568
1569        try:
1570            with open(self.fname, "r", encoding="utf8",
1571                      errors="backslashreplace") as fp:
1572
1573                for line in fp:
1574                    self.process_export(export_table, line)
1575
1576        except IOError:
1577            return None
1578
1579        return export_table
1580
1581    #
1582    # The state/action table telling us which function to invoke in
1583    # each state.
1584    #
1585    state_actions = {
1586        state.NORMAL:			process_normal,
1587        state.NAME:			process_name,
1588        state.BODY:			process_body,
1589        state.DECLARATION:		process_decl,
1590        state.SPECIAL_SECTION:		process_special,
1591        state.INLINE_NAME:		process_inline_name,
1592        state.INLINE_TEXT:		process_inline_text,
1593        state.PROTO:			process_proto,
1594        state.DOCBLOCK:			process_docblock,
1595        }
1596
1597    def parse_kdoc(self):
1598        """
1599        Open and process each line of a C source file.
1600        The parsing is controlled via a state machine, and the line is passed
1601        to a different process function depending on the state. The process
1602        function may update the state as needed.
1603
1604        Besides parsing kernel-doc tags, it also parses export symbols.
1605        """
1606
1607        prev = ""
1608        prev_ln = None
1609        export_table = set()
1610
1611        try:
1612            with open(self.fname, "r", encoding="utf8",
1613                      errors="backslashreplace") as fp:
1614                for ln, line in enumerate(fp):
1615
1616                    line = line.expandtabs().strip("\n")
1617
1618                    # Group continuation lines on prototypes
1619                    if self.state == state.PROTO:
1620                        if line.endswith("\\"):
1621                            prev += line.rstrip("\\")
1622                            if not prev_ln:
1623                                prev_ln = ln
1624                            continue
1625
1626                        if prev:
1627                            ln = prev_ln
1628                            line = prev + line
1629                            prev = ""
1630                            prev_ln = None
1631
1632                    self.config.log.debug("%d %s: %s",
1633                                          ln, state.name[self.state],
1634                                          line)
1635
1636                    # This is an optimization over the original script.
1637                    # There, when export_file was used for the same file,
1638                    # it was read twice. Here, we use the already-existing
1639                    # loop to parse exported symbols as well.
1640                    #
1641                    if (self.state != state.NORMAL) or \
1642                       not self.process_export(export_table, line):
1643                        # Hand this line to the appropriate state handler
1644                        self.state_actions[self.state](self, ln, line)
1645
1646        except OSError:
1647            self.config.log.error(f"Error: Cannot open file {self.fname}")
1648
1649        return export_table, self.entries
1650