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kdoc_parser.py

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linux-6.19.14/tools/lib/python/kdoc/kdoc_parser.py PYTHON
   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.kdoc_re import NestedMatch, KernRe
  20from kdoc.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 it easier to
  26# convert from the Perl 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*__private', re.S), ' '),
  90    (KernRe(r'\s*__rcu', re.S), ' '),
  91    (KernRe(r'\s*____cacheline_aligned_in_smp', re.S), ' '),
  92    (KernRe(r'\s*____cacheline_aligned', re.S), ' '),
  93    (KernRe(r'\s*__cacheline_group_(begin|end)\([^\)]+\);'), ''),
  94    #
  95    # Unwrap struct_group macros based on this definition:
  96    # __struct_group(TAG, NAME, ATTRS, MEMBERS...)
  97    # which has variants like: struct_group(NAME, MEMBERS...)
  98    # Only MEMBERS arguments require documentation.
  99    #
 100    # Parsing them happens on two steps:
 101    #
 102    # 1. drop struct group arguments that aren't at MEMBERS,
 103    #    storing them as STRUCT_GROUP(MEMBERS)
 104    #
 105    # 2. remove STRUCT_GROUP() ancillary macro.
 106    #
 107    # The original logic used to remove STRUCT_GROUP() using an
 108    # advanced regex:
 109    #
 110    #   \bSTRUCT_GROUP(\(((?:(?>[^)(]+)|(?1))*)\))[^;]*;
 111    #
 112    # with two patterns that are incompatible with
 113    # Python re module, as it has:
 114    #
 115    #   - a recursive pattern: (?1)
 116    #   - an atomic grouping: (?>...)
 117    #
 118    # I tried a simpler version: but it didn't work either:
 119    #   \bSTRUCT_GROUP\(([^\)]+)\)[^;]*;
 120    #
 121    # As it doesn't properly match the end parenthesis on some cases.
 122    #
 123    # So, a better solution was crafted: there's now a NestedMatch
 124    # class that ensures that delimiters after a search are properly
 125    # matched. So, the implementation to drop STRUCT_GROUP() will be
 126    # handled in separate.
 127    #
 128    (KernRe(r'\bstruct_group\s*\(([^,]*,)', re.S), r'STRUCT_GROUP('),
 129    (KernRe(r'\bstruct_group_attr\s*\(([^,]*,){2}', re.S), r'STRUCT_GROUP('),
 130    (KernRe(r'\bstruct_group_tagged\s*\(([^,]*),([^,]*),', re.S), r'struct \1 \2; STRUCT_GROUP('),
 131    (KernRe(r'\b__struct_group\s*\(([^,]*,){3}', re.S), r'STRUCT_GROUP('),
 132    #
 133    # Replace macros
 134    #
 135    # TODO: use NestedMatch for FOO($1, $2, ...) matches
 136    #
 137    # it is better to also move those to the NestedMatch logic,
 138    # to ensure that parentheses will be properly matched.
 139    #
 140    (KernRe(r'__ETHTOOL_DECLARE_LINK_MODE_MASK\s*\(([^\)]+)\)', re.S),
 141     r'DECLARE_BITMAP(\1, __ETHTOOL_LINK_MODE_MASK_NBITS)'),
 142    (KernRe(r'DECLARE_PHY_INTERFACE_MASK\s*\(([^\)]+)\)', re.S),
 143     r'DECLARE_BITMAP(\1, PHY_INTERFACE_MODE_MAX)'),
 144    (KernRe(r'DECLARE_BITMAP\s*\(' + struct_args_pattern + r',\s*' + struct_args_pattern + r'\)',
 145            re.S), r'unsigned long \1[BITS_TO_LONGS(\2)]'),
 146    (KernRe(r'DECLARE_HASHTABLE\s*\(' + struct_args_pattern + r',\s*' + struct_args_pattern + r'\)',
 147            re.S), r'unsigned long \1[1 << ((\2) - 1)]'),
 148    (KernRe(r'DECLARE_KFIFO\s*\(' + struct_args_pattern + r',\s*' + struct_args_pattern +
 149            r',\s*' + struct_args_pattern + r'\)', re.S), r'\2 *\1'),
 150    (KernRe(r'DECLARE_KFIFO_PTR\s*\(' + struct_args_pattern + r',\s*' +
 151            struct_args_pattern + r'\)', re.S), r'\2 *\1'),
 152    (KernRe(r'(?:__)?DECLARE_FLEX_ARRAY\s*\(' + struct_args_pattern + r',\s*' +
 153            struct_args_pattern + r'\)', re.S), r'\1 \2[]'),
 154    (KernRe(r'DEFINE_DMA_UNMAP_ADDR\s*\(' + struct_args_pattern + r'\)', re.S), r'dma_addr_t \1'),
 155    (KernRe(r'DEFINE_DMA_UNMAP_LEN\s*\(' + struct_args_pattern + r'\)', re.S), r'__u32 \1'),
 156]
 157#
 158# Regexes here are guaranteed to have the end delimiter matching
 159# the start delimiter. Yet, right now, only one replace group
 160# is allowed.
 161#
 162struct_nested_prefixes = [
 163    (re.compile(r'\bSTRUCT_GROUP\('), r'\1'),
 164]
 165
 166#
 167# Transforms for function prototypes
 168#
 169function_xforms  = [
 170    (KernRe(r"^static +"), ""),
 171    (KernRe(r"^extern +"), ""),
 172    (KernRe(r"^asmlinkage +"), ""),
 173    (KernRe(r"^inline +"), ""),
 174    (KernRe(r"^__inline__ +"), ""),
 175    (KernRe(r"^__inline +"), ""),
 176    (KernRe(r"^__always_inline +"), ""),
 177    (KernRe(r"^noinline +"), ""),
 178    (KernRe(r"^__FORTIFY_INLINE +"), ""),
 179    (KernRe(r"__init +"), ""),
 180    (KernRe(r"__init_or_module +"), ""),
 181    (KernRe(r"__deprecated +"), ""),
 182    (KernRe(r"__flatten +"), ""),
 183    (KernRe(r"__meminit +"), ""),
 184    (KernRe(r"__must_check +"), ""),
 185    (KernRe(r"__weak +"), ""),
 186    (KernRe(r"__sched +"), ""),
 187    (KernRe(r"_noprof"), ""),
 188    (KernRe(r"__always_unused *"), ""),
 189    (KernRe(r"__printf\s*\(\s*\d*\s*,\s*\d*\s*\) +"), ""),
 190    (KernRe(r"__(?:re)?alloc_size\s*\(\s*\d+\s*(?:,\s*\d+\s*)?\) +"), ""),
 191    (KernRe(r"__diagnose_as\s*\(\s*\S+\s*(?:,\s*\d+\s*)*\) +"), ""),
 192    (KernRe(r"DECL_BUCKET_PARAMS\s*\(\s*(\S+)\s*,\s*(\S+)\s*\)"), r"\1, \2"),
 193    (KernRe(r"__attribute_const__ +"), ""),
 194    (KernRe(r"__attribute__\s*\(\((?:[\w\s]+(?:\([^)]*\))?\s*,?)+\)\)\s+"), ""),
 195]
 196
 197#
 198# Apply a set of transforms to a block of text.
 199#
 200def apply_transforms(xforms, text):
 201    for search, subst in xforms:
 202        text = search.sub(subst, text)
 203    return text
 204
 205#
 206# A little helper to get rid of excess white space
 207#
 208multi_space = KernRe(r'\s\s+')
 209def trim_whitespace(s):
 210    return multi_space.sub(' ', s.strip())
 211
 212#
 213# Remove struct/enum members that have been marked "private".
 214#
 215def trim_private_members(text):
 216    #
 217    # First look for a "public:" block that ends a private region, then
 218    # handle the "private until the end" case.
 219    #
 220    text = KernRe(r'/\*\s*private:.*?/\*\s*public:.*?\*/', flags=re.S).sub('', text)
 221    text = KernRe(r'/\*\s*private:.*', flags=re.S).sub('', text)
 222    #
 223    # We needed the comments to do the above, but now we can take them out.
 224    #
 225    return KernRe(r'\s*/\*.*?\*/\s*', flags=re.S).sub('', text).strip()
 226
 227class state:
 228    """
 229    State machine enums
 230    """
 231
 232    # Parser states
 233    NORMAL        = 0        # normal code
 234    NAME          = 1        # looking for function name
 235    DECLARATION   = 2        # We have seen a declaration which might not be done
 236    BODY          = 3        # the body of the comment
 237    SPECIAL_SECTION = 4      # doc section ending with a blank line
 238    PROTO         = 5        # scanning prototype
 239    DOCBLOCK      = 6        # documentation block
 240    INLINE_NAME   = 7        # gathering doc outside main block
 241    INLINE_TEXT   = 8	     # reading the body of inline docs
 242
 243    name = [
 244        "NORMAL",
 245        "NAME",
 246        "DECLARATION",
 247        "BODY",
 248        "SPECIAL_SECTION",
 249        "PROTO",
 250        "DOCBLOCK",
 251        "INLINE_NAME",
 252        "INLINE_TEXT",
 253    ]
 254
 255
 256SECTION_DEFAULT = "Description"  # default section
 257
 258class KernelEntry:
 259
 260    def __init__(self, config, fname, ln):
 261        self.config = config
 262        self.fname = fname
 263
 264        self._contents = []
 265        self.prototype = ""
 266
 267        self.warnings = []
 268
 269        self.parameterlist = []
 270        self.parameterdescs = {}
 271        self.parametertypes = {}
 272        self.parameterdesc_start_lines = {}
 273
 274        self.section_start_lines = {}
 275        self.sections = {}
 276
 277        self.anon_struct_union = False
 278
 279        self.leading_space = None
 280
 281        self.fname = fname
 282
 283        # State flags
 284        self.brcount = 0
 285        self.declaration_start_line = ln + 1
 286
 287    #
 288    # Management of section contents
 289    #
 290    def add_text(self, text):
 291        self._contents.append(text)
 292
 293    def contents(self):
 294        return '\n'.join(self._contents) + '\n'
 295
 296    # TODO: rename to emit_message after removal of kernel-doc.pl
 297    def emit_msg(self, ln, msg, *, warning=True):
 298        """Emit a message."""
 299
 300        log_msg = f"{self.fname}:{ln} {msg}"
 301
 302        if not warning:
 303            self.config.log.info(log_msg)
 304            return
 305
 306        # Delegate warning output to output logic, as this way it
 307        # will report warnings/info only for symbols that are output
 308
 309        self.warnings.append(log_msg)
 310        return
 311
 312    #
 313    # Begin a new section.
 314    #
 315    def begin_section(self, line_no, title = SECTION_DEFAULT, dump = False):
 316        if dump:
 317            self.dump_section(start_new = True)
 318        self.section = title
 319        self.new_start_line = line_no
 320
 321    def dump_section(self, start_new=True):
 322        """
 323        Dumps section contents to arrays/hashes intended for that purpose.
 324        """
 325        #
 326        # If we have accumulated no contents in the default ("description")
 327        # section, don't bother.
 328        #
 329        if self.section == SECTION_DEFAULT and not self._contents:
 330            return
 331        name = self.section
 332        contents = self.contents()
 333
 334        if type_param.match(name):
 335            name = type_param.group(1)
 336
 337            self.parameterdescs[name] = contents
 338            self.parameterdesc_start_lines[name] = self.new_start_line
 339
 340            self.new_start_line = 0
 341
 342        else:
 343            if name in self.sections and self.sections[name] != "":
 344                # Only warn on user-specified duplicate section names
 345                if name != SECTION_DEFAULT:
 346                    self.emit_msg(self.new_start_line,
 347                                  f"duplicate section name '{name}'")
 348                # Treat as a new paragraph - add a blank line
 349                self.sections[name] += '\n' + contents
 350            else:
 351                self.sections[name] = contents
 352                self.section_start_lines[name] = self.new_start_line
 353                self.new_start_line = 0
 354
 355#        self.config.log.debug("Section: %s : %s", name, pformat(vars(self)))
 356
 357        if start_new:
 358            self.section = SECTION_DEFAULT
 359            self._contents = []
 360
 361python_warning = False
 362
 363class KernelDoc:
 364    """
 365    Read a C language source or header FILE and extract embedded
 366    documentation comments.
 367    """
 368
 369    # Section names
 370
 371    section_context = "Context"
 372    section_return = "Return"
 373
 374    undescribed = "-- undescribed --"
 375
 376    def __init__(self, config, fname):
 377        """Initialize internal variables"""
 378
 379        self.fname = fname
 380        self.config = config
 381
 382        # Initial state for the state machines
 383        self.state = state.NORMAL
 384
 385        # Store entry currently being processed
 386        self.entry = None
 387
 388        # Place all potential outputs into an array
 389        self.entries = []
 390
 391        #
 392        # We need Python 3.7 for its "dicts remember the insertion
 393        # order" guarantee
 394        #
 395        global python_warning
 396        if (not python_warning and
 397            sys.version_info.major == 3 and sys.version_info.minor < 7):
 398
 399            self.emit_msg(0,
 400                          'Python 3.7 or later is required for correct results')
 401            python_warning = True
 402
 403    def emit_msg(self, ln, msg, *, warning=True):
 404        """Emit a message"""
 405
 406        if self.entry:
 407            self.entry.emit_msg(ln, msg, warning=warning)
 408            return
 409
 410        log_msg = f"{self.fname}:{ln} {msg}"
 411
 412        if warning:
 413            self.config.log.warning(log_msg)
 414        else:
 415            self.config.log.info(log_msg)
 416
 417    def dump_section(self, start_new=True):
 418        """
 419        Dumps section contents to arrays/hashes intended for that purpose.
 420        """
 421
 422        if self.entry:
 423            self.entry.dump_section(start_new)
 424
 425    # TODO: rename it to store_declaration after removal of kernel-doc.pl
 426    def output_declaration(self, dtype, name, **args):
 427        """
 428        Stores the entry into an entry array.
 429
 430        The actual output and output filters will be handled elsewhere
 431        """
 432
 433        item = KdocItem(name, self.fname, dtype,
 434                        self.entry.declaration_start_line, **args)
 435        item.warnings = self.entry.warnings
 436
 437        # Drop empty sections
 438        # TODO: improve empty sections logic to emit warnings
 439        sections = self.entry.sections
 440        for section in ["Description", "Return"]:
 441            if section in sections and not sections[section].rstrip():
 442                del sections[section]
 443        item.set_sections(sections, self.entry.section_start_lines)
 444        item.set_params(self.entry.parameterlist, self.entry.parameterdescs,
 445                        self.entry.parametertypes,
 446                        self.entry.parameterdesc_start_lines)
 447        self.entries.append(item)
 448
 449        self.config.log.debug("Output: %s:%s = %s", dtype, name, pformat(args))
 450
 451    def emit_unused_warnings(self):
 452        """
 453        When the parser fails to produce a valid entry, it places some
 454        warnings under `entry.warnings` that will be discarded when resetting
 455        the state.
 456
 457        Ensure that those warnings are not lost.
 458
 459        .. note::
 460
 461              Because we are calling `config.warning()` here, those
 462              warnings are not filtered by the `-W` parameters: they will all
 463              be produced even when `-Wreturn`, `-Wshort-desc`, and/or
 464              `-Wcontents-before-sections` are used.
 465
 466              Allowing those warnings to be filtered is complex, because it
 467              would require storing them in a buffer and then filtering them
 468              during the output step of the code, depending on the
 469              selected symbols.
 470        """
 471        if self.entry and self.entry not in self.entries:
 472            for log_msg in self.entry.warnings:
 473                self.config.warning(log_msg)
 474
 475    def reset_state(self, ln):
 476        """
 477        Ancillary routine to create a new entry. It initializes all
 478        variables used by the state machine.
 479        """
 480
 481        self.emit_unused_warnings()
 482
 483        self.entry = KernelEntry(self.config, self.fname, ln)
 484
 485        # State flags
 486        self.state = state.NORMAL
 487
 488    def push_parameter(self, ln, decl_type, param, dtype,
 489                       org_arg, declaration_name):
 490        """
 491        Store parameters and their descriptions at self.entry.
 492        """
 493
 494        if self.entry.anon_struct_union and dtype == "" and param == "}":
 495            return  # Ignore the ending }; from anonymous struct/union
 496
 497        self.entry.anon_struct_union = False
 498
 499        param = KernRe(r'[\[\)].*').sub('', param, count=1)
 500
 501        #
 502        # Look at various "anonymous type" cases.
 503        #
 504        if dtype == '':
 505            if param.endswith("..."):
 506                if len(param) > 3: # there is a name provided, use that
 507                    param = param[:-3]
 508                if not self.entry.parameterdescs.get(param):
 509                    self.entry.parameterdescs[param] = "variable arguments"
 510
 511            elif (not param) or param == "void":
 512                param = "void"
 513                self.entry.parameterdescs[param] = "no arguments"
 514
 515            elif param in ["struct", "union"]:
 516                # Handle unnamed (anonymous) union or struct
 517                dtype = param
 518                param = "{unnamed_" + param + "}"
 519                self.entry.parameterdescs[param] = "anonymous\n"
 520                self.entry.anon_struct_union = True
 521
 522        # Warn if parameter has no description
 523        # (but ignore ones starting with # as these are not parameters
 524        # but inline preprocessor statements)
 525        if param not in self.entry.parameterdescs and not param.startswith("#"):
 526            self.entry.parameterdescs[param] = self.undescribed
 527
 528            if "." not in param:
 529                if decl_type == 'function':
 530                    dname = f"{decl_type} parameter"
 531                else:
 532                    dname = f"{decl_type} member"
 533
 534                self.emit_msg(ln,
 535                              f"{dname} '{param}' not described in '{declaration_name}'")
 536
 537        # Strip spaces from param so that it is one continuous string on
 538        # parameterlist. This fixes a problem where check_sections()
 539        # cannot find a parameter like "addr[6 + 2]" because it actually
 540        # appears as "addr[6", "+", "2]" on the parameter list.
 541        # However, it's better to maintain the param string unchanged for
 542        # output, so just weaken the string compare in check_sections()
 543        # to ignore "[blah" in a parameter string.
 544
 545        self.entry.parameterlist.append(param)
 546        org_arg = KernRe(r'\s\s+').sub(' ', org_arg)
 547        self.entry.parametertypes[param] = org_arg
 548
 549
 550    def create_parameter_list(self, ln, decl_type, args,
 551                              splitter, declaration_name):
 552        """
 553        Creates a list of parameters, storing them at self.entry.
 554        """
 555
 556        # temporarily replace all commas inside function pointer definition
 557        arg_expr = KernRe(r'(\([^\),]+),')
 558        while arg_expr.search(args):
 559            args = arg_expr.sub(r"\1#", args)
 560
 561        for arg in args.split(splitter):
 562            # Ignore argument attributes
 563            arg = KernRe(r'\sPOS0?\s').sub(' ', arg)
 564
 565            # Strip leading/trailing spaces
 566            arg = arg.strip()
 567            arg = KernRe(r'\s+').sub(' ', arg, count=1)
 568
 569            if arg.startswith('#'):
 570                # Treat preprocessor directive as a typeless variable just to fill
 571                # corresponding data structures "correctly". Catch it later in
 572                # output_* subs.
 573
 574                # Treat preprocessor directive as a typeless variable
 575                self.push_parameter(ln, decl_type, arg, "",
 576                                    "", declaration_name)
 577            #
 578            # The pointer-to-function case.
 579            #
 580            elif KernRe(r'\(.+\)\s*\(').search(arg):
 581                arg = arg.replace('#', ',')
 582                r = KernRe(r'[^\(]+\(\*?\s*'  # Everything up to "(*"
 583                           r'([\w\[\].]*)'    # Capture the name and possible [array]
 584                           r'\s*\)')	      # Make sure the trailing ")" is there
 585                if r.match(arg):
 586                    param = r.group(1)
 587                else:
 588                    self.emit_msg(ln, f"Invalid param: {arg}")
 589                    param = arg
 590                dtype = arg.replace(param, '')
 591                self.push_parameter(ln, decl_type, param, dtype, arg, declaration_name)
 592            #
 593            # The array-of-pointers case.  Dig the parameter name out from the middle
 594            # of the declaration.
 595            #
 596            elif KernRe(r'\(.+\)\s*\[').search(arg):
 597                r = KernRe(r'[^\(]+\(\s*\*\s*'		# Up to "(" and maybe "*"
 598                           r'([\w.]*?)'			# The actual pointer name
 599                           r'\s*(\[\s*\w+\s*\]\s*)*\)') # The [array portion]
 600                if r.match(arg):
 601                    param = r.group(1)
 602                else:
 603                    self.emit_msg(ln, f"Invalid param: {arg}")
 604                    param = arg
 605                dtype = arg.replace(param, '')
 606                self.push_parameter(ln, decl_type, param, dtype, arg, declaration_name)
 607            elif arg:
 608                #
 609                # Clean up extraneous spaces and split the string at commas; the first
 610                # element of the resulting list will also include the type information.
 611                #
 612                arg = KernRe(r'\s*:\s*').sub(":", arg)
 613                arg = KernRe(r'\s*\[').sub('[', arg)
 614                args = KernRe(r'\s*,\s*').split(arg)
 615                args[0] = re.sub(r'(\*+)\s*', r' \1', args[0])
 616                #
 617                # args[0] has a string of "type a".  If "a" includes an [array]
 618                # declaration, we want to not be fooled by any white space inside
 619                # the brackets, so detect and handle that case specially.
 620                #
 621                r = KernRe(r'^([^[\]]*\s+)(.*)$')
 622                if r.match(args[0]):
 623                    args[0] = r.group(2)
 624                    dtype = r.group(1)
 625                else:
 626                    # No space in args[0]; this seems wrong but preserves previous behavior
 627                    dtype = ''
 628
 629                bitfield_re = KernRe(r'(.*?):(\w+)')
 630                for param in args:
 631                    #
 632                    # For pointers, shift the star(s) from the variable name to the
 633                    # type declaration.
 634                    #
 635                    r = KernRe(r'^(\*+)\s*(.*)')
 636                    if r.match(param):
 637                        self.push_parameter(ln, decl_type, r.group(2),
 638                                            f"{dtype} {r.group(1)}",
 639                                            arg, declaration_name)
 640                    #
 641                    # Perform a similar shift for bitfields.
 642                    #
 643                    elif bitfield_re.search(param):
 644                        if dtype != "":  # Skip unnamed bit-fields
 645                            self.push_parameter(ln, decl_type, bitfield_re.group(1),
 646                                                f"{dtype}:{bitfield_re.group(2)}",
 647                                                arg, declaration_name)
 648                    else:
 649                        self.push_parameter(ln, decl_type, param, dtype,
 650                                            arg, declaration_name)
 651
 652    def check_sections(self, ln, decl_name, decl_type):
 653        """
 654        Check for errors inside sections, emitting warnings if not found
 655        parameters are described.
 656        """
 657        for section in self.entry.sections:
 658            if section not in self.entry.parameterlist and \
 659               not known_sections.search(section):
 660                if decl_type == 'function':
 661                    dname = f"{decl_type} parameter"
 662                else:
 663                    dname = f"{decl_type} member"
 664                self.emit_msg(ln,
 665                              f"Excess {dname} '{section}' description in '{decl_name}'")
 666
 667    def check_return_section(self, ln, declaration_name, return_type):
 668        """
 669        If the function doesn't return void, warns about the lack of a
 670        return description.
 671        """
 672
 673        if not self.config.wreturn:
 674            return
 675
 676        # Ignore an empty return type (It's a macro)
 677        # Ignore functions with a "void" return type (but not "void *")
 678        if not return_type or KernRe(r'void\s*\w*\s*$').search(return_type):
 679            return
 680
 681        if not self.entry.sections.get("Return", None):
 682            self.emit_msg(ln,
 683                          f"No description found for return value of '{declaration_name}'")
 684
 685    #
 686    # Split apart a structure prototype; returns (struct|union, name, members) or None
 687    #
 688    def split_struct_proto(self, proto):
 689        type_pattern = r'(struct|union)'
 690        qualifiers = [
 691            "__attribute__",
 692            "__packed",
 693            "__aligned",
 694            "____cacheline_aligned_in_smp",
 695            "____cacheline_aligned",
 696        ]
 697        definition_body = r'\{(.*)\}\s*' + "(?:" + '|'.join(qualifiers) + ")?"
 698
 699        r = KernRe(type_pattern + r'\s+(\w+)\s*' + definition_body)
 700        if r.search(proto):
 701            return (r.group(1), r.group(2), r.group(3))
 702        else:
 703            r = KernRe(r'typedef\s+' + type_pattern + r'\s*' + definition_body + r'\s*(\w+)\s*;')
 704            if r.search(proto):
 705                return (r.group(1), r.group(3), r.group(2))
 706        return None
 707    #
 708    # Rewrite the members of a structure or union for easier formatting later on.
 709    # Among other things, this function will turn a member like:
 710    #
 711    #  struct { inner_members; } foo;
 712    #
 713    # into:
 714    #
 715    #  struct foo; inner_members;
 716    #
 717    def rewrite_struct_members(self, members):
 718        #
 719        # Process struct/union members from the most deeply nested outward.  The
 720        # trick is in the ^{ below - it prevents a match of an outer struct/union
 721        # until the inner one has been munged (removing the "{" in the process).
 722        #
 723        struct_members = KernRe(r'(struct|union)'   # 0: declaration type
 724                                r'([^\{\};]+)' 	    # 1: possible name
 725                                r'(\{)'
 726                                r'([^\{\}]*)'       # 3: Contents of declaration
 727                                r'(\})'
 728                                r'([^\{\};]*)(;)')  # 5: Remaining stuff after declaration
 729        tuples = struct_members.findall(members)
 730        while tuples:
 731            for t in tuples:
 732                newmember = ""
 733                oldmember = "".join(t) # Reconstruct the original formatting
 734                dtype, name, lbr, content, rbr, rest, semi = t
 735                #
 736                # Pass through each field name, normalizing the form and formatting.
 737                #
 738                for s_id in rest.split(','):
 739                    s_id = s_id.strip()
 740                    newmember += f"{dtype} {s_id}; "
 741                    #
 742                    # Remove bitfield/array/pointer info, getting the bare name.
 743                    #
 744                    s_id = KernRe(r'[:\[].*').sub('', s_id)
 745                    s_id = KernRe(r'^\s*\**(\S+)\s*').sub(r'\1', s_id)
 746                    #
 747                    # Pass through the members of this inner structure/union.
 748                    #
 749                    for arg in content.split(';'):
 750                        arg = arg.strip()
 751                        #
 752                        # Look for (type)(*name)(args) - pointer to function
 753                        #
 754                        r = KernRe(r'^([^\(]+\(\*?\s*)([\w.]*)(\s*\).*)')
 755                        if r.match(arg):
 756                            dtype, name, extra = r.group(1), r.group(2), r.group(3)
 757                            # Pointer-to-function
 758                            if not s_id:
 759                                # Anonymous struct/union
 760                                newmember += f"{dtype}{name}{extra}; "
 761                            else:
 762                                newmember += f"{dtype}{s_id}.{name}{extra}; "
 763                        #
 764                        # Otherwise a non-function member.
 765                        #
 766                        else:
 767                            #
 768                            # Remove bitmap and array portions and spaces around commas
 769                            #
 770                            arg = KernRe(r':\s*\d+\s*').sub('', arg)
 771                            arg = KernRe(r'\[.*\]').sub('', arg)
 772                            arg = KernRe(r'\s*,\s*').sub(',', arg)
 773                            #
 774                            # Look for a normal decl - "type name[,name...]"
 775                            #
 776                            r = KernRe(r'(.*)\s+([\S+,]+)')
 777                            if r.search(arg):
 778                                for name in r.group(2).split(','):
 779                                    name = KernRe(r'^\s*\**(\S+)\s*').sub(r'\1', name)
 780                                    if not s_id:
 781                                        # Anonymous struct/union
 782                                        newmember += f"{r.group(1)} {name}; "
 783                                    else:
 784                                        newmember += f"{r.group(1)} {s_id}.{name}; "
 785                            else:
 786                                newmember += f"{arg}; "
 787                #
 788                # At the end of the s_id loop, replace the original declaration with
 789                # the munged version.
 790                #
 791                members = members.replace(oldmember, newmember)
 792            #
 793            # End of the tuple loop - search again and see if there are outer members
 794            # that now turn up.
 795            #
 796            tuples = struct_members.findall(members)
 797        return members
 798
 799    #
 800    # Format the struct declaration into a standard form for inclusion in the
 801    # resulting docs.
 802    #
 803    def format_struct_decl(self, declaration):
 804        #
 805        # Insert newlines, get rid of extra spaces.
 806        #
 807        declaration = KernRe(r'([\{;])').sub(r'\1\n', declaration)
 808        declaration = KernRe(r'\}\s+;').sub('};', declaration)
 809        #
 810        # Format inline enums with each member on its own line.
 811        #
 812        r = KernRe(r'(enum\s+\{[^\}]+),([^\n])')
 813        while r.search(declaration):
 814            declaration = r.sub(r'\1,\n\2', declaration)
 815        #
 816        # Now go through and supply the right number of tabs
 817        # for each line.
 818        #
 819        def_args = declaration.split('\n')
 820        level = 1
 821        declaration = ""
 822        for clause in def_args:
 823            clause = KernRe(r'\s+').sub(' ', clause.strip(), count=1)
 824            if clause:
 825                if '}' in clause and level > 1:
 826                    level -= 1
 827                if not clause.startswith('#'):
 828                    declaration += "\t" * level
 829                declaration += "\t" + clause + "\n"
 830                if "{" in clause and "}" not in clause:
 831                    level += 1
 832        return declaration
 833
 834
 835    def dump_struct(self, ln, proto):
 836        """
 837        Store an entry for a struct or union
 838        """
 839        #
 840        # Do the basic parse to get the pieces of the declaration.
 841        #
 842        struct_parts = self.split_struct_proto(proto)
 843        if not struct_parts:
 844            self.emit_msg(ln, f"{proto} error: Cannot parse struct or union!")
 845            return
 846        decl_type, declaration_name, members = struct_parts
 847
 848        if self.entry.identifier != declaration_name:
 849            self.emit_msg(ln, f"expecting prototype for {decl_type} {self.entry.identifier}. "
 850                          f"Prototype was for {decl_type} {declaration_name} instead\n")
 851            return
 852        #
 853        # Go through the list of members applying all of our transformations.
 854        #
 855        members = trim_private_members(members)
 856        members = apply_transforms(struct_xforms, members)
 857
 858        nested = NestedMatch()
 859        for search, sub in struct_nested_prefixes:
 860            members = nested.sub(search, sub, members)
 861        #
 862        # Deal with embedded struct and union members, and drop enums entirely.
 863        #
 864        declaration = members
 865        members = self.rewrite_struct_members(members)
 866        members = re.sub(r'(\{[^\{\}]*\})', '', members)
 867        #
 868        # Output the result and we are done.
 869        #
 870        self.create_parameter_list(ln, decl_type, members, ';',
 871                                   declaration_name)
 872        self.check_sections(ln, declaration_name, decl_type)
 873        self.output_declaration(decl_type, declaration_name,
 874                                definition=self.format_struct_decl(declaration),
 875                                purpose=self.entry.declaration_purpose)
 876
 877    def dump_enum(self, ln, proto):
 878        """
 879        Stores an enum inside self.entries array.
 880        """
 881        #
 882        # Strip preprocessor directives.  Note that this depends on the
 883        # trailing semicolon we added in process_proto_type().
 884        #
 885        proto = KernRe(r'#\s*((define|ifdef|if)\s+|endif)[^;]*;', flags=re.S).sub('', proto)
 886        #
 887        # Parse out the name and members of the enum.  Typedef form first.
 888        #
 889        r = KernRe(r'typedef\s+enum\s*\{(.*)\}\s*(\w*)\s*;')
 890        if r.search(proto):
 891            declaration_name = r.group(2)
 892            members = trim_private_members(r.group(1))
 893        #
 894        # Failing that, look for a straight enum
 895        #
 896        else:
 897            r = KernRe(r'enum\s+(\w*)\s*\{(.*)\}')
 898            if r.match(proto):
 899                declaration_name = r.group(1)
 900                members = trim_private_members(r.group(2))
 901        #
 902        # OK, this isn't going to work.
 903        #
 904            else:
 905                self.emit_msg(ln, f"{proto}: error: Cannot parse enum!")
 906                return
 907        #
 908        # Make sure we found what we were expecting.
 909        #
 910        if self.entry.identifier != declaration_name:
 911            if self.entry.identifier == "":
 912                self.emit_msg(ln,
 913                              f"{proto}: wrong kernel-doc identifier on prototype")
 914            else:
 915                self.emit_msg(ln,
 916                              f"expecting prototype for enum {self.entry.identifier}. "
 917                              f"Prototype was for enum {declaration_name} instead")
 918            return
 919
 920        if not declaration_name:
 921            declaration_name = "(anonymous)"
 922        #
 923        # Parse out the name of each enum member, and verify that we
 924        # have a description for it.
 925        #
 926        member_set = set()
 927        members = KernRe(r'\([^;)]*\)').sub('', members)
 928        for arg in members.split(','):
 929            if not arg:
 930                continue
 931            arg = KernRe(r'^\s*(\w+).*').sub(r'\1', arg)
 932            self.entry.parameterlist.append(arg)
 933            if arg not in self.entry.parameterdescs:
 934                self.entry.parameterdescs[arg] = self.undescribed
 935                self.emit_msg(ln,
 936                              f"Enum value '{arg}' not described in enum '{declaration_name}'")
 937            member_set.add(arg)
 938        #
 939        # Ensure that every described member actually exists in the enum.
 940        #
 941        for k in self.entry.parameterdescs:
 942            if k not in member_set:
 943                self.emit_msg(ln,
 944                              f"Excess enum value '@{k}' description in '{declaration_name}'")
 945
 946        self.output_declaration('enum', declaration_name,
 947                                purpose=self.entry.declaration_purpose)
 948
 949    def dump_declaration(self, ln, prototype):
 950        """
 951        Stores a data declaration inside self.entries array.
 952        """
 953
 954        if self.entry.decl_type == "enum":
 955            self.dump_enum(ln, prototype)
 956        elif self.entry.decl_type == "typedef":
 957            self.dump_typedef(ln, prototype)
 958        elif self.entry.decl_type in ["union", "struct"]:
 959            self.dump_struct(ln, prototype)
 960        else:
 961            # This would be a bug
 962            self.emit_message(ln, f'Unknown declaration type: {self.entry.decl_type}')
 963
 964    def dump_function(self, ln, prototype):
 965        """
 966        Stores a function or function macro inside self.entries array.
 967        """
 968
 969        found = func_macro = False
 970        return_type = ''
 971        decl_type = 'function'
 972        #
 973        # Apply the initial transformations.
 974        #
 975        prototype = apply_transforms(function_xforms, prototype)
 976        #
 977        # If we have a macro, remove the "#define" at the front.
 978        #
 979        new_proto = KernRe(r"^#\s*define\s+").sub("", prototype)
 980        if new_proto != prototype:
 981            prototype = new_proto
 982            #
 983            # Dispense with the simple "#define A B" case here; the key
 984            # is the space after the name of the symbol being defined.
 985            # NOTE that the seemingly misnamed "func_macro" indicates a
 986            # macro *without* arguments.
 987            #
 988            r = KernRe(r'^(\w+)\s+')
 989            if r.search(prototype):
 990                return_type = ''
 991                declaration_name = r.group(1)
 992                func_macro = True
 993                found = True
 994
 995        # Yes, this truly is vile.  We are looking for:
 996        # 1. Return type (may be nothing if we're looking at a macro)
 997        # 2. Function name
 998        # 3. Function parameters.
 999        #
1000        # All the while we have to watch out for function pointer parameters
1001        # (which IIRC is what the two sections are for), C types (these
1002        # regexps don't even start to express all the possibilities), and
1003        # so on.
1004        #
1005        # If you mess with these regexps, it's a good idea to check that
1006        # the following functions' documentation still comes out right:
1007        # - parport_register_device (function pointer parameters)
1008        # - atomic_set (macro)
1009        # - pci_match_device, __copy_to_user (long return type)
1010
1011        name = r'\w+'
1012        type1 = r'(?:[\w\s]+)?'
1013        type2 = r'(?:[\w\s]+\*+)+'
1014        #
1015        # Attempt to match first on (args) with no internal parentheses; this
1016        # lets us easily filter out __acquires() and other post-args stuff.  If
1017        # that fails, just grab the rest of the line to the last closing
1018        # parenthesis.
1019        #
1020        proto_args = r'\(([^\(]*|.*)\)'
1021        #
1022        # (Except for the simple macro case) attempt to split up the prototype
1023        # in the various ways we understand.
1024        #
1025        if not found:
1026            patterns = [
1027                rf'^()({name})\s*{proto_args}',
1028                rf'^({type1})\s+({name})\s*{proto_args}',
1029                rf'^({type2})\s*({name})\s*{proto_args}',
1030            ]
1031
1032            for p in patterns:
1033                r = KernRe(p)
1034                if r.match(prototype):
1035                    return_type = r.group(1)
1036                    declaration_name = r.group(2)
1037                    args = r.group(3)
1038                    self.create_parameter_list(ln, decl_type, args, ',',
1039                                               declaration_name)
1040                    found = True
1041                    break
1042        #
1043        # Parsing done; make sure that things are as we expect.
1044        #
1045        if not found:
1046            self.emit_msg(ln,
1047                          f"cannot understand function prototype: '{prototype}'")
1048            return
1049        if self.entry.identifier != declaration_name:
1050            self.emit_msg(ln, f"expecting prototype for {self.entry.identifier}(). "
1051                          f"Prototype was for {declaration_name}() instead")
1052            return
1053        self.check_sections(ln, declaration_name, "function")
1054        self.check_return_section(ln, declaration_name, return_type)
1055        #
1056        # Store the result.
1057        #
1058        self.output_declaration(decl_type, declaration_name,
1059                                typedef=('typedef' in return_type),
1060                                functiontype=return_type,
1061                                purpose=self.entry.declaration_purpose,
1062                                func_macro=func_macro)
1063
1064
1065    def dump_typedef(self, ln, proto):
1066        """
1067        Stores a typedef inside self.entries array.
1068        """
1069        #
1070        # We start by looking for function typedefs.
1071        #
1072        typedef_type = r'typedef((?:\s+[\w*]+\b){0,7}\s+(?:\w+\b|\*+))\s*'
1073        typedef_ident = r'\*?\s*(\w\S+)\s*'
1074        typedef_args = r'\s*\((.*)\);'
1075
1076        typedef1 = KernRe(typedef_type + r'\(' + typedef_ident + r'\)' + typedef_args)
1077        typedef2 = KernRe(typedef_type + typedef_ident + typedef_args)
1078
1079        # Parse function typedef prototypes
1080        for r in [typedef1, typedef2]:
1081            if not r.match(proto):
1082                continue
1083
1084            return_type = r.group(1).strip()
1085            declaration_name = r.group(2)
1086            args = r.group(3)
1087
1088            if self.entry.identifier != declaration_name:
1089                self.emit_msg(ln,
1090                              f"expecting prototype for typedef {self.entry.identifier}. Prototype was for typedef {declaration_name} instead\n")
1091                return
1092
1093            self.create_parameter_list(ln, 'function', args, ',', declaration_name)
1094
1095            self.output_declaration('function', declaration_name,
1096                                    typedef=True,
1097                                    functiontype=return_type,
1098                                    purpose=self.entry.declaration_purpose)
1099            return
1100        #
1101        # Not a function, try to parse a simple typedef.
1102        #
1103        r = KernRe(r'typedef.*\s+(\w+)\s*;')
1104        if r.match(proto):
1105            declaration_name = r.group(1)
1106
1107            if self.entry.identifier != declaration_name:
1108                self.emit_msg(ln,
1109                              f"expecting prototype for typedef {self.entry.identifier}. Prototype was for typedef {declaration_name} instead\n")
1110                return
1111
1112            self.output_declaration('typedef', declaration_name,
1113                                    purpose=self.entry.declaration_purpose)
1114            return
1115
1116        self.emit_msg(ln, "error: Cannot parse typedef!")
1117
1118    @staticmethod
1119    def process_export(function_set, line):
1120        """
1121        process EXPORT_SYMBOL* tags
1122
1123        This method doesn't use any variable from the class, so declare it
1124        with a staticmethod decorator.
1125        """
1126
1127        # We support documenting some exported symbols with different
1128        # names.  A horrible hack.
1129        suffixes = [ '_noprof' ]
1130
1131        # Note: it accepts only one EXPORT_SYMBOL* per line, as having
1132        # multiple export lines would violate Kernel coding style.
1133
1134        if export_symbol.search(line):
1135            symbol = export_symbol.group(2)
1136        elif export_symbol_ns.search(line):
1137            symbol = export_symbol_ns.group(2)
1138        else:
1139            return False
1140        #
1141        # Found an export, trim out any special suffixes
1142        #
1143        for suffix in suffixes:
1144            # Be backward compatible with Python < 3.9
1145            if symbol.endswith(suffix):
1146                symbol = symbol[:-len(suffix)]
1147        function_set.add(symbol)
1148        return True
1149
1150    def process_normal(self, ln, line):
1151        """
1152        STATE_NORMAL: looking for the /** to begin everything.
1153        """
1154
1155        if not doc_start.match(line):
1156            return
1157
1158        # start a new entry
1159        self.reset_state(ln)
1160
1161        # next line is always the function name
1162        self.state = state.NAME
1163
1164    def process_name(self, ln, line):
1165        """
1166        STATE_NAME: Looking for the "name - description" line
1167        """
1168        #
1169        # Check for a DOC: block and handle them specially.
1170        #
1171        if doc_block.search(line):
1172
1173            if not doc_block.group(1):
1174                self.entry.begin_section(ln, "Introduction")
1175            else:
1176                self.entry.begin_section(ln, doc_block.group(1))
1177
1178            self.entry.identifier = self.entry.section
1179            self.state = state.DOCBLOCK
1180        #
1181        # Otherwise we're looking for a normal kerneldoc declaration line.
1182        #
1183        elif doc_decl.search(line):
1184            self.entry.identifier = doc_decl.group(1)
1185
1186            # Test for data declaration
1187            if doc_begin_data.search(line):
1188                self.entry.decl_type = doc_begin_data.group(1)
1189                self.entry.identifier = doc_begin_data.group(2)
1190            #
1191            # Look for a function description
1192            #
1193            elif doc_begin_func.search(line):
1194                self.entry.identifier = doc_begin_func.group(1)
1195                self.entry.decl_type = "function"
1196            #
1197            # We struck out.
1198            #
1199            else:
1200                self.emit_msg(ln,
1201                              f"This comment starts with '/**', but isn't a kernel-doc comment. Refer to Documentation/doc-guide/kernel-doc.rst\n{line}")
1202                self.state = state.NORMAL
1203                return
1204            #
1205            # OK, set up for a new kerneldoc entry.
1206            #
1207            self.state = state.BODY
1208            self.entry.identifier = self.entry.identifier.strip(" ")
1209            # if there's no @param blocks need to set up default section here
1210            self.entry.begin_section(ln + 1)
1211            #
1212            # Find the description portion, which *should* be there but
1213            # isn't always.
1214            # (We should be able to capture this from the previous parsing - someday)
1215            #
1216            r = KernRe("[-:](.*)")
1217            if r.search(line):
1218                self.entry.declaration_purpose = trim_whitespace(r.group(1))
1219                self.state = state.DECLARATION
1220            else:
1221                self.entry.declaration_purpose = ""
1222
1223            if not self.entry.declaration_purpose and self.config.wshort_desc:
1224                self.emit_msg(ln,
1225                              f"missing initial short description on line:\n{line}")
1226
1227            if not self.entry.identifier and self.entry.decl_type != "enum":
1228                self.emit_msg(ln,
1229                              f"wrong kernel-doc identifier on line:\n{line}")
1230                self.state = state.NORMAL
1231
1232            if self.config.verbose:
1233                self.emit_msg(ln,
1234                              f"Scanning doc for {self.entry.decl_type} {self.entry.identifier}",
1235                                  warning=False)
1236        #
1237        # Failed to find an identifier. Emit a warning
1238        #
1239        else:
1240            self.emit_msg(ln, f"Cannot find identifier on line:\n{line}")
1241
1242    #
1243    # Helper function to determine if a new section is being started.
1244    #
1245    def is_new_section(self, ln, line):
1246        if doc_sect.search(line):
1247            self.state = state.BODY
1248            #
1249            # Pick out the name of our new section, tweaking it if need be.
1250            #
1251            newsection = doc_sect.group(1)
1252            if newsection.lower() == 'description':
1253                newsection = 'Description'
1254            elif newsection.lower() == 'context':
1255                newsection = 'Context'
1256                self.state = state.SPECIAL_SECTION
1257            elif newsection.lower() in ["@return", "@returns",
1258                                        "return", "returns"]:
1259                newsection = "Return"
1260                self.state = state.SPECIAL_SECTION
1261            elif newsection[0] == '@':
1262                self.state = state.SPECIAL_SECTION
1263            #
1264            # Initialize the contents, and get the new section going.
1265            #
1266            newcontents = doc_sect.group(2)
1267            if not newcontents:
1268                newcontents = ""
1269            self.dump_section()
1270            self.entry.begin_section(ln, newsection)
1271            self.entry.leading_space = None
1272
1273            self.entry.add_text(newcontents.lstrip())
1274            return True
1275        return False
1276
1277    #
1278    # Helper function to detect (and effect) the end of a kerneldoc comment.
1279    #
1280    def is_comment_end(self, ln, line):
1281        if doc_end.search(line):
1282            self.dump_section()
1283
1284            # Look for doc_com + <text> + doc_end:
1285            r = KernRe(r'\s*\*\s*[a-zA-Z_0-9:.]+\*/')
1286            if r.match(line):
1287                self.emit_msg(ln, f"suspicious ending line: {line}")
1288
1289            self.entry.prototype = ""
1290            self.entry.new_start_line = ln + 1
1291
1292            self.state = state.PROTO
1293            return True
1294        return False
1295
1296
1297    def process_decl(self, ln, line):
1298        """
1299        STATE_DECLARATION: We've seen the beginning of a declaration
1300        """
1301        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
1302            return
1303        #
1304        # Look for anything with the " * " line beginning.
1305        #
1306        if doc_content.search(line):
1307            cont = doc_content.group(1)
1308            #
1309            # A blank line means that we have moved out of the declaration
1310            # part of the comment (without any "special section" parameter
1311            # descriptions).
1312            #
1313            if cont == "":
1314                self.state = state.BODY
1315            #
1316            # Otherwise we have more of the declaration section to soak up.
1317            #
1318            else:
1319                self.entry.declaration_purpose = \
1320                    trim_whitespace(self.entry.declaration_purpose + ' ' + cont)
1321        else:
1322            # Unknown line, ignore
1323            self.emit_msg(ln, f"bad line: {line}")
1324
1325
1326    def process_special(self, ln, line):
1327        """
1328        STATE_SPECIAL_SECTION: a section ending with a blank line
1329        """
1330        #
1331        # If we have hit a blank line (only the " * " marker), then this
1332        # section is done.
1333        #
1334        if KernRe(r"\s*\*\s*$").match(line):
1335            self.entry.begin_section(ln, dump = True)
1336            self.state = state.BODY
1337            return
1338        #
1339        # Not a blank line, look for the other ways to end the section.
1340        #
1341        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
1342            return
1343        #
1344        # OK, we should have a continuation of the text for this section.
1345        #
1346        if doc_content.search(line):
1347            cont = doc_content.group(1)
1348            #
1349            # If the lines of text after the first in a special section have
1350            # leading white space, we need to trim it out or Sphinx will get
1351            # confused.  For the second line (the None case), see what we
1352            # find there and remember it.
1353            #
1354            if self.entry.leading_space is None:
1355                r = KernRe(r'^(\s+)')
1356                if r.match(cont):
1357                    self.entry.leading_space = len(r.group(1))
1358                else:
1359                    self.entry.leading_space = 0
1360            #
1361            # Otherwise, before trimming any leading chars, be *sure*
1362            # that they are white space.  We should maybe warn if this
1363            # isn't the case.
1364            #
1365            for i in range(0, self.entry.leading_space):
1366                if cont[i] != " ":
1367                    self.entry.leading_space = i
1368                    break
1369            #
1370            # Add the trimmed result to the section and we're done.
1371            #
1372            self.entry.add_text(cont[self.entry.leading_space:])
1373        else:
1374            # Unknown line, ignore
1375            self.emit_msg(ln, f"bad line: {line}")
1376
1377    def process_body(self, ln, line):
1378        """
1379        STATE_BODY: the bulk of a kerneldoc comment.
1380        """
1381        if self.is_new_section(ln, line) or self.is_comment_end(ln, line):
1382            return
1383
1384        if doc_content.search(line):
1385            cont = doc_content.group(1)
1386            self.entry.add_text(cont)
1387        else:
1388            # Unknown line, ignore
1389            self.emit_msg(ln, f"bad line: {line}")
1390
1391    def process_inline_name(self, ln, line):
1392        """STATE_INLINE_NAME: beginning of docbook comments within a prototype."""
1393
1394        if doc_inline_sect.search(line):
1395            self.entry.begin_section(ln, doc_inline_sect.group(1))
1396            self.entry.add_text(doc_inline_sect.group(2).lstrip())
1397            self.state = state.INLINE_TEXT
1398        elif doc_inline_end.search(line):
1399            self.dump_section()
1400            self.state = state.PROTO
1401        elif doc_content.search(line):
1402            self.emit_msg(ln, f"Incorrect use of kernel-doc format: {line}")
1403            self.state = state.PROTO
1404        # else ... ??
1405
1406    def process_inline_text(self, ln, line):
1407        """STATE_INLINE_TEXT: docbook comments within a prototype."""
1408
1409        if doc_inline_end.search(line):
1410            self.dump_section()
1411            self.state = state.PROTO
1412        elif doc_content.search(line):
1413            self.entry.add_text(doc_content.group(1))
1414        # else ... ??
1415
1416    def syscall_munge(self, ln, proto):         # pylint: disable=W0613
1417        """
1418        Handle syscall definitions
1419        """
1420
1421        is_void = False
1422
1423        # Strip newlines/CR's
1424        proto = re.sub(r'[\r\n]+', ' ', proto)
1425
1426        # Check if it's a SYSCALL_DEFINE0
1427        if 'SYSCALL_DEFINE0' in proto:
1428            is_void = True
1429
1430        # Replace SYSCALL_DEFINE with correct return type & function name
1431        proto = KernRe(r'SYSCALL_DEFINE.*\(').sub('long sys_', proto)
1432
1433        r = KernRe(r'long\s+(sys_.*?),')
1434        if r.search(proto):
1435            proto = KernRe(',').sub('(', proto, count=1)
1436        elif is_void:
1437            proto = KernRe(r'\)').sub('(void)', proto, count=1)
1438
1439        # Now delete all of the odd-numbered commas in the proto
1440        # so that argument types & names don't have a comma between them
1441        count = 0
1442        length = len(proto)
1443
1444        if is_void:
1445            length = 0  # skip the loop if is_void
1446
1447        for ix in range(length):
1448            if proto[ix] == ',':
1449                count += 1
1450                if count % 2 == 1:
1451                    proto = proto[:ix] + ' ' + proto[ix + 1:]
1452
1453        return proto
1454
1455    def tracepoint_munge(self, ln, proto):
1456        """
1457        Handle tracepoint definitions
1458        """
1459
1460        tracepointname = None
1461        tracepointargs = None
1462
1463        # Match tracepoint name based on different patterns
1464        r = KernRe(r'TRACE_EVENT\((.*?),')
1465        if r.search(proto):
1466            tracepointname = r.group(1)
1467
1468        r = KernRe(r'DEFINE_SINGLE_EVENT\((.*?),')
1469        if r.search(proto):
1470            tracepointname = r.group(1)
1471
1472        r = KernRe(r'DEFINE_EVENT\((.*?),(.*?),')
1473        if r.search(proto):
1474            tracepointname = r.group(2)
1475
1476        if tracepointname:
1477            tracepointname = tracepointname.lstrip()
1478
1479        r = KernRe(r'TP_PROTO\((.*?)\)')
1480        if r.search(proto):
1481            tracepointargs = r.group(1)
1482
1483        if not tracepointname or not tracepointargs:
1484            self.emit_msg(ln,
1485                          f"Unrecognized tracepoint format:\n{proto}\n")
1486        else:
1487            proto = f"static inline void trace_{tracepointname}({tracepointargs})"
1488            self.entry.identifier = f"trace_{self.entry.identifier}"
1489
1490        return proto
1491
1492    def process_proto_function(self, ln, line):
1493        """Ancillary routine to process a function prototype"""
1494
1495        # strip C99-style comments to end of line
1496        line = KernRe(r"//.*$", re.S).sub('', line)
1497        #
1498        # Soak up the line's worth of prototype text, stopping at { or ; if present.
1499        #
1500        if KernRe(r'\s*#\s*define').match(line):
1501            self.entry.prototype = line
1502        elif not line.startswith('#'):   # skip other preprocessor stuff
1503            r = KernRe(r'([^\{]*)')
1504            if r.match(line):
1505                self.entry.prototype += r.group(1) + " "
1506        #
1507        # If we now have the whole prototype, clean it up and declare victory.
1508        #
1509        if '{' in line or ';' in line or KernRe(r'\s*#\s*define').match(line):
1510            # strip comments and surrounding spaces
1511            self.entry.prototype = KernRe(r'/\*.*\*/').sub('', self.entry.prototype).strip()
1512            #
1513            # Handle self.entry.prototypes for function pointers like:
1514            #       int (*pcs_config)(struct foo)
1515            # by turning it into
1516            #	    int pcs_config(struct foo)
1517            #
1518            r = KernRe(r'^(\S+\s+)\(\s*\*(\S+)\)')
1519            self.entry.prototype = r.sub(r'\1\2', self.entry.prototype)
1520            #
1521            # Handle special declaration syntaxes
1522            #
1523            if 'SYSCALL_DEFINE' in self.entry.prototype:
1524                self.entry.prototype = self.syscall_munge(ln,
1525                                                          self.entry.prototype)
1526            else:
1527                r = KernRe(r'TRACE_EVENT|DEFINE_EVENT|DEFINE_SINGLE_EVENT')
1528                if r.search(self.entry.prototype):
1529                    self.entry.prototype = self.tracepoint_munge(ln,
1530                                                                 self.entry.prototype)
1531            #
1532            # ... and we're done
1533            #
1534            self.dump_function(ln, self.entry.prototype)
1535            self.reset_state(ln)
1536
1537    def process_proto_type(self, ln, line):
1538        """Ancillary routine to process a type"""
1539
1540        # Strip C99-style comments and surrounding whitespace
1541        line = KernRe(r"//.*$", re.S).sub('', line).strip()
1542        if not line:
1543            return # nothing to see here
1544
1545        # To distinguish preprocessor directive from regular declaration later.
1546        if line.startswith('#'):
1547            line += ";"
1548        #
1549        # Split the declaration on any of { } or ;, and accumulate pieces
1550        # until we hit a semicolon while not inside {brackets}
1551        #
1552        r = KernRe(r'(.*?)([{};])')
1553        for chunk in r.split(line):
1554            if chunk:  # Ignore empty matches
1555                self.entry.prototype += chunk
1556                #
1557                # This cries out for a match statement ... someday after we can
1558                # drop Python 3.9 ...
1559                #
1560                if chunk == '{':
1561                    self.entry.brcount += 1
1562                elif chunk == '}':
1563                    self.entry.brcount -= 1
1564                elif chunk == ';' and self.entry.brcount <= 0:
1565                    self.dump_declaration(ln, self.entry.prototype)
1566                    self.reset_state(ln)
1567                    return
1568        #
1569        # We hit the end of the line while still in the declaration; put
1570        # in a space to represent the newline.
1571        #
1572        self.entry.prototype += ' '
1573
1574    def process_proto(self, ln, line):
1575        """STATE_PROTO: reading a function/whatever prototype."""
1576
1577        if doc_inline_oneline.search(line):
1578            self.entry.begin_section(ln, doc_inline_oneline.group(1))
1579            self.entry.add_text(doc_inline_oneline.group(2))
1580            self.dump_section()
1581
1582        elif doc_inline_start.search(line):
1583            self.state = state.INLINE_NAME
1584
1585        elif self.entry.decl_type == 'function':
1586            self.process_proto_function(ln, line)
1587
1588        else:
1589            self.process_proto_type(ln, line)
1590
1591    def process_docblock(self, ln, line):
1592        """STATE_DOCBLOCK: within a DOC: block."""
1593
1594        if doc_end.search(line):
1595            self.dump_section()
1596            self.output_declaration("doc", self.entry.identifier)
1597            self.reset_state(ln)
1598
1599        elif doc_content.search(line):
1600            self.entry.add_text(doc_content.group(1))
1601
1602    def parse_export(self):
1603        """
1604        Parses EXPORT_SYMBOL* macros from a single Kernel source file.
1605        """
1606
1607        export_table = set()
1608
1609        try:
1610            with open(self.fname, "r", encoding="utf8",
1611                      errors="backslashreplace") as fp:
1612
1613                for line in fp:
1614                    self.process_export(export_table, line)
1615
1616        except IOError:
1617            return None
1618
1619        return export_table
1620
1621    #
1622    # The state/action table telling us which function to invoke in
1623    # each state.
1624    #
1625    state_actions = {
1626        state.NORMAL:			process_normal,
1627        state.NAME:			process_name,
1628        state.BODY:			process_body,
1629        state.DECLARATION:		process_decl,
1630        state.SPECIAL_SECTION:		process_special,
1631        state.INLINE_NAME:		process_inline_name,
1632        state.INLINE_TEXT:		process_inline_text,
1633        state.PROTO:			process_proto,
1634        state.DOCBLOCK:			process_docblock,
1635        }
1636
1637    def parse_kdoc(self):
1638        """
1639        Open and process each line of a C source file.
1640        The parsing is controlled via a state machine, and the line is passed
1641        to a different process function depending on the state. The process
1642        function may update the state as needed.
1643
1644        Besides parsing kernel-doc tags, it also parses export symbols.
1645        """
1646
1647        prev = ""
1648        prev_ln = None
1649        export_table = set()
1650
1651        try:
1652            with open(self.fname, "r", encoding="utf8",
1653                      errors="backslashreplace") as fp:
1654                for ln, line in enumerate(fp):
1655
1656                    line = line.expandtabs().strip("\n")
1657
1658                    # Group continuation lines on prototypes
1659                    if self.state == state.PROTO:
1660                        if line.endswith("\\"):
1661                            prev += line.rstrip("\\")
1662                            if not prev_ln:
1663                                prev_ln = ln
1664                            continue
1665
1666                        if prev:
1667                            ln = prev_ln
1668                            line = prev + line
1669                            prev = ""
1670                            prev_ln = None
1671
1672                    self.config.log.debug("%d %s: %s",
1673                                          ln, state.name[self.state],
1674                                          line)
1675
1676                    # This is an optimization over the original script.
1677                    # There, when export_file was used for the same file,
1678                    # it was read twice. Here, we use the already-existing
1679                    # loop to parse exported symbols as well.
1680                    #
1681                    if (self.state != state.NORMAL) or \
1682                       not self.process_export(export_table, line):
1683                        # Hand this line to the appropriate state handler
1684                        self.state_actions[self.state](self, ln, line)
1685
1686            self.emit_unused_warnings()
1687
1688        except OSError:
1689            self.config.log.error(f"Error: Cannot open file {self.fname}")
1690
1691        return export_table, self.entries
~/ Read-only file preview.