class RDoc::Parser::C

def add_alias(var_name, class_obj, old_name, new_name, comment)
  al = RDoc::Alias.new '', old_name, new_name, ''
  al.singleton = @singleton_classes.key? var_name
  al.comment = comment
  al.record_location @top_level
  class_obj.add_alias al
  @stats.add_alias al
  al
end

def do_aliases
  @content.scan(/rb_define_alias\s*\(
                 \s*(\w+),
                 \s*"(.+?)",
                 \s*"(.+?)"
                 \s*\)/xm) do |var_name, new_name, old_name|
    class_name = @known_classes[var_name]
    unless class_name then
      @options.warn "Enclosing class or module %p for alias %s %s is not known" % [
        var_name, new_name, old_name]
      next
    end
    class_obj = find_class var_name, class_name
    comment = find_alias_comment var_name, new_name, old_name
    comment.normalize
    if comment.to_s.empty? and existing_method = class_obj.method_list.find { |m| m.name == old_name}
      comment = existing_method.comment
    end
    add_alias(var_name, class_obj, old_name, new_name, comment)
  end
end

def do_attrs
  @content.scan(/rb_attr\s*\(
                 \s*(\w+),
                 \s*([\w"()]+),
                 #{BOOL_ARG_PATTERN},
                 #{BOOL_ARG_PATTERN},
                 \s*\w+\);/xmo) do |var_name, attr_name, read, write|
    handle_attr var_name, attr_name, read, write
  end
  @content.scan(%r%rb_define_attr\(
                           \s*([\w\.]+),
                           \s*"([^"]+)",
                           #{BOOL_ARG_PATTERN},
                           #{BOOL_ARG_PATTERN}\);
              %xmo) do |var_name, attr_name, read, write|
    handle_attr var_name, attr_name, read, write
  end
end

def do_boot_defclass
  @content.scan(/(\w+)\s*=\s*boot_defclass\s*\(\s*"(\w+?)",\s*(\w+?)\s*\)/) do
    |var_name, class_name, parent|
    parent = nil if parent == "0"
    handle_class_module(var_name, :class, class_name, parent, nil)
  end
end

def do_classes_and_modules
  do_boot_defclass if @file_name == "class.c"
  @content.scan(
    %r(
      (?<open>\s*\(\s*) {0}
      (?<close>\s*\)\s*) {0}
      (?<name>\s*"(?<class_name>\w+)") {0}
      (?<parent>\s*(?:
        (?<parent_name>[\w\*\s\(\)\.\->]+) |
        rb_path2class\s*\(\s*"(?<path>[\w:]+)"\s*\)
      )) {0}
      (?<under>\w+) {0}
      (?<var_name>[\w\.]+)\s* =
      \s*rb_(?:
        define_(?:
          class(?: # rb_define_class(name, parent_name)
            \(\s*
              \g<name>,
              \g<parent>
            \s*\)
          |
            _under\g<open> # rb_define_class_under(under, name, parent_name...)
              \g<under>,
              \g<name>,
              \g<parent>
            \g<close>
          )
        |
          (?<module>)
          module(?: # rb_define_module(name)
            \g<open>
              \g<name>
            \g<close>
          |
            _under\g<open> # rb_define_module_under(under, name)
              \g<under>,
              \g<name>
            \g<close>
          )
        )
    |
      (?<attributes>(?:\s*"\w+",)*\s*NULL\s*) {0}
      struct_define(?:
        \g<open> # rb_struct_define(name, ...)
          \g<name>,
      |
        _under\g<open> # rb_struct_define_under(under, name, ...)
          \g<under>,
          \g<name>,
      |
        _without_accessor(?:
          \g<open> # rb_struct_define_without_accessor(name, parent_name, ...)
        |
          _under\g<open> # rb_struct_define_without_accessor_under(under, name, parent_name, ...)
            \g<under>,
        )
          \g<name>,
          \g<parent>,
          \s*\w+,        # Allocation function
      )
        \g<attributes>
      \g<close>
    |
      singleton_class\g<open> # rb_singleton_class(target_class_name)
        (?<target_class_name>\w+)
      \g<close>
      )
    )mx
  ) do
    if target_class_name = $~[:target_class_name]
      # rb_singleton_class(target_class_name)
      handle_singleton $~[:var_name], target_class_name
      next
    end
    var_name = $~[:var_name]
    type = $~[:module] ? :module : :class
    class_name = $~[:class_name]
    parent_name = $~[:parent_name] || $~[:path]
    under = $~[:under]
    attributes = $~[:attributes]
    handle_class_module(var_name, type, class_name, parent_name, under)
    if attributes and !parent_name # rb_struct_define *not* without_accessor
      true_flag = 'Qtrue'
      attributes.scan(/"\K\w+(?=")/) do |attr_name|
        handle_attr var_name, attr_name, true_flag, true_flag
      end
    end
  end
end

def do_constants
  @content.scan(%r%\Wrb_define_
                 ( variable          |
                   readonly_variable |
                   const             |
                   global_const        )
             \s*\(
               (?:\s*(\w+),)?
               \s*"(\w+)",
               \s*(.*?)\s*\)\s*;
               %xm) do |type, var_name, const_name, definition|
    var_name = "rb_cObject" if !var_name or var_name == "rb_mKernel"
    type = "const" if type == "global_const"
    handle_constants type, var_name, const_name, definition
  end
  @content.scan(%r%
                \Wrb_curses_define_const
                \s*\(
                  \s*
                  (\w+)
                  \s*
                \)
                \s*;%xm) do |consts|
    const = consts.first
    handle_constants 'const', 'mCurses', const, "UINT2NUM(#{const})"
  end
  @content.scan(%r%
                \Wrb_file_const
                \s*\(
                  \s*
                  "([^"]+)",
                  \s*
                  (.*?)
                  \s*
                \)
                \s*;%xm) do |name, value|
    handle_constants 'const', 'rb_mFConst', name, value
  end
end

def do_includes
  @content.scan(/rb_include_module\s*\(\s*(\w+?),\s*(\w+?)\s*\)/) do |c, m|
    next unless cls = @classes[c]
    m = @known_classes[m] || m
    comment = new_comment '', @top_level, :c
    incl = cls.add_include RDoc::Include.new(m, comment)
    incl.record_location @top_level
  end
end

def do_methods
  @content.scan(%r%rb_define_
                 (
                    singleton_method |
                    method           |
                    module_function  |
                    private_method
                 )
                 \s*\(\s*([\w\.]+),
                   \s*"([^"]+)",
                   \s*(?:RUBY_METHOD_FUNC\(|VALUEFUNC\(|\(METHOD\))?(\w+)\)?,
                   \s*(-?\w+)\s*\)
                 (?:;\s*/[*/]\s+in\s+(\w+?\.(?:cpp|c|y)))?
               %xm) do |type, var_name, meth_name, function, param_count, source_file|
    # Ignore top-object and weird struct.c dynamic stuff
    next if var_name == "ruby_top_self"
    next if var_name == "nstr"
    var_name = "rb_cObject" if var_name == "rb_mKernel"
    handle_method(type, var_name, meth_name, function, param_count,
                  source_file)
  end
  @content.scan(%r%rb_define_global_function\s*\(
                           \s*"([^"]+)",
                           \s*(?:RUBY_METHOD_FUNC\(|VALUEFUNC\()?(\w+)\)?,
                           \s*(-?\w+)\s*\)
              (?:;\s*/[*/]\s+in\s+(\w+?\.[cy]))?
              %xm) do |meth_name, function, param_count, source_file|
    handle_method("method", "rb_mKernel", meth_name, function, param_count,
                  source_file)
  end
  @content.scan(/define_filetest_function\s*\(
                   \s*"([^"]+)",
                   \s*(?:RUBY_METHOD_FUNC\(|VALUEFUNC\()?(\w+)\)?,
                   \s*(-?\w+)\s*\)/xm) do |meth_name, function, param_count|
    handle_method("method", "rb_mFileTest", meth_name, function, param_count)
    handle_method("singleton_method", "rb_cFile", meth_name, function,
                  param_count)
  end
end

def do_missing
  return if @missing_dependencies.empty?
  @enclosure_dependencies.tsort.each do |in_module|
    arguments = @missing_dependencies.delete in_module
    next unless arguments # dependency on existing class
    handle_class_module(*arguments)
  end
end

def find_alias_comment class_name, new_name, old_name
  content =~ %r%((?>/\*.*?\*/\s+))
                rb_define_alias\(\s*#{Regexp.escape class_name}\s*,
                                 \s*"#{Regexp.escape new_name}"\s*,
                                 \s*"#{Regexp.escape old_name}"\s*\);%xm
  new_comment($1 || '', @top_level, :c)
end

def find_attr_comment var_name, attr_name, read = nil, write = nil
  attr_name = Regexp.escape attr_name
  rw = if read and write then
         /\s*#{read}\s*,\s*#{write}\s*/xm
       else
         /.*?/m
       end
  comment = if @content =~ %r%((?>/\*.*?\*/\s+))
                              rb_define_attr\((?:\s*#{var_name},)?\s*
                                              "#{attr_name}"\s*,
                                              #{rw}\)\s*;%xm then
              $1
            elsif @content =~ %r%((?>/\*.*?\*/\s+))
                                 rb_attr\(\s*#{var_name}\s*,
                                          \s*#{attr_name}\s*,
                                          #{rw},.*?\)\s*;%xm then
              $1
            elsif @content =~ %r%(/\*.*?(?:\s*\*\s*)?)
                                 Document-attr:\s#{attr_name}\s*?\n
                                 ((?>(.|\n)*?\*/))%x then
              "#{$1}\n#{$2}"
            else
              ''
            end
  new_comment comment, @top_level, :c
end

def find_body class_name, meth_name, meth_obj, file_content, quiet = false
  if file_content
    @body_table ||= {}
    @body_table[file_content] ||= gen_body_table file_content
    type, *args = @body_table[file_content][meth_name]
  end
  case type
  when :func_def
    comment = new_comment args[0], @top_level, :c
    body = args[1]
    offset, = args[2]
    comment.remove_private if comment
    # try to find the whole body
    body = $& if /#{Regexp.escape body}[^(]*?\{.*?^\}/m =~ file_content
    # The comment block may have been overridden with a 'Document-method'
    # block. This happens in the interpreter when multiple methods are
    # vectored through to the same C method but those methods are logically
    # distinct (for example Kernel.hash and Kernel.object_id share the same
    # implementation
    override_comment = find_override_comment class_name, meth_obj
    comment = override_comment if override_comment
    comment.normalize
    find_modifiers comment, meth_obj if comment
    #meth_obj.params = params
    meth_obj.start_collecting_tokens
    tk = { :line_no => 1, :char_no => 1, :text => body }
    meth_obj.add_token tk
    meth_obj.comment = comment
    meth_obj.line    = file_content[0, offset].count("\n") + 1
    body
  when :macro_def
    comment = new_comment args[0], @top_level, :c
    body = args[1]
    offset, = args[2]
    find_body class_name, args[3], meth_obj, file_content, true
    comment.normalize
    find_modifiers comment, meth_obj
    meth_obj.start_collecting_tokens
    tk = { :line_no => 1, :char_no => 1, :text => body }
    meth_obj.add_token tk
    meth_obj.comment = comment
    meth_obj.line    = file_content[0, offset].count("\n") + 1
    body
  when :macro_alias
    # with no comment we hope the aliased definition has it and use it's
    # definition
    body = find_body(class_name, args[0], meth_obj, file_content, true)
    return body if body
    @options.warn "No definition for #{meth_name}"
    false
  else # No body, but might still have an override comment
    comment = find_override_comment class_name, meth_obj
    if comment then
      comment.normalize
      find_modifiers comment, meth_obj
      meth_obj.comment = comment
      ''
    else
      @options.warn "No definition for #{meth_name}"
      false
    end
  end
end

def find_class(raw_name, name, base_name = nil)
  unless @classes[raw_name]
    if raw_name =~ /^rb_m/
      container = @top_level.add_module RDoc::NormalModule, name
    else
      container = @top_level.add_class RDoc::NormalClass, name
    end
    container.name = base_name if base_name
    container.record_location @top_level
    @classes[raw_name] = container
  end
  @classes[raw_name]
end

def find_class_comment class_name, class_mod
  comment = nil
  if @content =~ %r%
      ((?>/\*.*?\*/\s+))
      (static\s+)?
      void\s+
      Init(?:VM)?_(?i:#{class_name})\s*(?:_\(\s*)?\(\s*(?:void\s*)?\)%xm then
    comment = $1.sub(%r%Document-(?:class|module):\s+#{class_name}%, '')
  elsif @content =~ %r%Document-(?:class|module):\s+#{class_name}\s*?
                       (?:<\s+[:,\w]+)?\n((?>.*?\*/))%xm then
    comment = "/*\n#{$1}"
  elsif @content =~ %r%((?>/\*.*?\*/\s+))
                       ([\w\.\s]+\s* = \s+)?rb_define_(class|module)[\t (]*?"(#{class_name})"%xm then
    comment = $1
  elsif @content =~ %r%((?>/\*.*?\*/\s+))
                       ([\w\. \t]+ = \s+)?rb_define_(class|module)_under[\t\w, (]*?"(#{class_name.split('::').last})"%xm then
    comment = $1
  else
    comment = ''
  end
  comment = new_comment comment, @top_level, :c
  comment.normalize
  look_for_directives_in class_mod, comment
  class_mod.add_comment comment, @top_level
end

def find_const_comment(type, const_name, class_name = nil)
  @const_table ||= {}
  @const_table[@content] ||= gen_const_table @content
  table = @const_table[@content]
  comment =
    table[[type, const_name]] ||
    (class_name && table[class_name + "::" + const_name]) ||
    table[const_name] ||
    ''
  new_comment comment, @top_level, :c
end

def find_modifiers comment, meth_obj
  comment.normalize
  comment.extract_call_seq meth_obj
  look_for_directives_in meth_obj, comment
end

def find_override_comment class_name, meth_obj
  name = Regexp.escape meth_obj.name
  prefix = Regexp.escape meth_obj.name_prefix
  comment = if @content =~ %r%Document-method:
                              \s+#{class_name}#{prefix}#{name}
                              \s*?\n((?>.*?\*/))%xm then
              "/*#{$1}"
            elsif @content =~ %r%Document-method:
                                 \s#{name}\s*?\n((?>.*?\*/))%xm then
              "/*#{$1}"
            end
  return unless comment
  new_comment comment, @top_level, :c
end

def gen_body_table file_content
  table = {}
  file_content.scan(%r{
    ((?>/\*.*?\*/\s*)?)
    ((?:\w+\s+){0,2} VALUE\s+(\w+)
      \s*(?:\([^\)]*\))(?:[^\);]|$))
  | ((?>/\*.*?\*/\s*))^\s*(\#\s*define\s+(\w+)\s+(\w+))
  | ^\s*\#\s*define\s+(\w+)\s+(\w+)
  }xm) do
    case
    when name = $3
      table[name] = [:func_def, $1, $2, $~.offset(2)] if !(t = table[name]) || t[0] != :func_def
    when name = $6
      table[name] = [:macro_def, $4, $5, $~.offset(5), $7] if !(t = table[name]) || t[0] == :macro_alias
    when name = $8
      table[name] ||= [:macro_alias, $9]
    end
  end
  table
end

def gen_const_table file_content
  table = {}
  @content.scan(%r{
    (?<doc>(?>^\s*/\*.*?\*/\s+))
      rb_define_(?<type>\w+)\(\s*(?:\w+),\s*
                         "(?<name>\w+)"\s*,
                         .*?\)\s*;
  | (?<doc>(?>^\s*/\*.*?\*/\s+))
      rb_define_global_(?<type>const)\(\s*
                         "(?<name>\w+)"\s*,
                         .*?\)\s*;
  |  (?<doc>(?>^\s*/\*.*?\*/\s+))
      rb_file_(?<type>const)\(\s*
                         "(?<name>\w+)"\s*,
                         .*?\)\s*;
  |  (?<doc>(?>^\s*/\*.*?\*/\s+))
      rb_curses_define_(?<type>const)\(\s*
                         (?<name>\w+)
                         \s*\)\s*;
  | Document-(?:const|global|variable):\s
      (?<name>(?:\w+::)*\w+)
      \s*?\n(?<doc>(?>.*?\*/))
  }mxi) do
    name, doc, type = $~.values_at(:name, :doc, :type)
    if type
      table[[type, name]] = doc
    else
      table[name] = "/*\n" + doc
    end
  end
  table
end

def handle_attr(var_name, attr_name, read, write)
  rw = ''
  rw += 'R' if TRUE_VALUES.include?(read)
  rw += 'W' if TRUE_VALUES.include?(write)
  class_name = @known_classes[var_name]
  return unless class_name
  class_obj = find_class var_name, class_name
  return unless class_obj
  comment = find_attr_comment var_name, attr_name
  comment.normalize
  name = attr_name.gsub(/rb_intern(?:_const)?\("([^"]+)"\)/, '\1')
  attr = RDoc::Attr.new '', name, rw, comment
  attr.record_location @top_level
  class_obj.add_attribute attr
  @stats.add_attribute attr
end

def handle_class_module(var_name, type, class_name, parent, in_module)
  parent_name = @known_classes[parent] || parent
  if in_module then
    enclosure = @classes[in_module] || @store.find_c_enclosure(in_module)
    if enclosure.nil? and enclosure = @known_classes[in_module] then
      enc_type = /^rb_m/ =~ in_module ? :module : :class
      handle_class_module in_module, enc_type, enclosure, nil, nil
      enclosure = @classes[in_module]
    end
    unless enclosure then
      @enclosure_dependencies[in_module] << var_name
      @missing_dependencies[var_name] =
        [var_name, type, class_name, parent, in_module]
      return
    end
  else
    enclosure = @top_level
  end
  if type == :class then
    full_name = if RDoc::ClassModule === enclosure then
                  enclosure.full_name + "::#{class_name}"
                else
                  class_name
                end
    if @content =~ %r%Document-class:\s+#{full_name}\s*<\s+([:,\w]+)% then
      parent_name = $1
    end
    cm = enclosure.add_class RDoc::NormalClass, class_name, parent_name
  else
    cm = enclosure.add_module RDoc::NormalModule, class_name
  end
  cm.record_location enclosure.top_level
  find_class_comment cm.full_name, cm
  case cm
  when RDoc::NormalClass
    @stats.add_class cm
  when RDoc::NormalModule
    @stats.add_module cm
  end
  @classes[var_name] = cm
  @known_classes[var_name] = cm.full_name
  @store.add_c_enclosure var_name, cm
end

def handle_constants(type, var_name, const_name, definition)
  class_name = @known_classes[var_name]
  return unless class_name
  class_obj = find_class var_name, class_name, class_name[/::\K[^:]+\z/]
  unless class_obj then
    @options.warn 'Enclosing class or module %p is not known' % [const_name]
    return
  end
  comment = find_const_comment type, const_name, class_name
  comment.normalize
  # In the case of rb_define_const, the definition and comment are in
  # "/* definition: comment */" form.  The literal ':' and '\' characters
  # can be escaped with a backslash.
  if type.downcase == 'const' then
    if /\A(.+?)?:(?!\S)/ =~ comment.text
      new_definition, new_comment = $1, $'
      if !new_definition # Default to literal C definition
        new_definition = definition
      else
        new_definition = new_definition.gsub(/\\([\\:])/, '\1')
      end
      new_definition.sub!(/\A(\s+)/, '')
      new_comment = "#{$1}#{new_comment.lstrip}"
      new_comment = self.new_comment(new_comment, @top_level, :c)
      con = RDoc::Constant.new const_name, new_definition, new_comment
    else
      con = RDoc::Constant.new const_name, definition, comment
    end
  else
    con = RDoc::Constant.new const_name, definition, comment
  end
  con.record_location @top_level
  @stats.add_constant con
  class_obj.add_constant con
end

def handle_ifdefs_in(body)
  body.gsub(/^#ifdef HAVE_PROTOTYPES.*?#else.*?\n(.*?)#endif.*?\n/m, '\1')
end

def handle_method(type, var_name, meth_name, function, param_count,
                  source_file = nil)
  class_name = @known_classes[var_name]
  singleton  = @singleton_classes.key? var_name
  @methods[var_name][function] << meth_name
  return unless class_name
  class_obj = find_class var_name, class_name
  if existing_method = class_obj.method_list.find { |m| m.c_function == function }
    add_alias(var_name, class_obj, existing_method.name, meth_name, existing_method.comment)
  end
  if class_obj then
    if meth_name == 'initialize' then
      meth_name = 'new'
      singleton = true
      type = 'method' # force public
    end
    meth_obj = RDoc::AnyMethod.new '', meth_name
    meth_obj.c_function = function
    meth_obj.singleton =
      singleton || %w[singleton_method module_function].include?(type)
    p_count = Integer(param_count) rescue -1
    if source_file then
      file_name = File.join @file_dir, source_file
      if File.exist? file_name then
        file_content = File.read file_name
      else
        @options.warn "unknown source #{source_file} for #{meth_name} in #{@file_name}"
      end
    else
      file_content = @content
    end
    body = find_body class_name, function, meth_obj, file_content
    if body and meth_obj.document_self then
      meth_obj.params = if p_count < -1 then # -2 is Array
                          '(*args)'
                        elsif p_count == -1 then # argc, argv
                          rb_scan_args body
                        else
                          args = (1..p_count).map { |i| "p#{i}" }
                          "(#{args.join ', '})"
                        end
      meth_obj.record_location @top_level
      if meth_obj.section_title
        class_obj.temporary_section = class_obj.add_section(meth_obj.section_title)
      end
      class_obj.add_method meth_obj
      @stats.add_method meth_obj
      meth_obj.visibility = :private if 'private_method' == type
    end
  end
end

def handle_singleton sclass_var, class_var
  class_name = @known_classes[class_var]
  @known_classes[sclass_var]     = class_name
  @singleton_classes[sclass_var] = class_name
end

def initialize top_level, file_name, content, options, stats
  super
  @known_classes = RDoc::KNOWN_CLASSES.dup
  @content = handle_tab_width handle_ifdefs_in @content
  @file_dir = File.dirname @file_name
  @classes           = load_variable_map :c_class_variables
  @singleton_classes = load_variable_map :c_singleton_class_variables
  @markup = @options.markup
  # class_variable => { function => [method, ...] }
  @methods = Hash.new { |h, f| h[f] = Hash.new { |i, m| i[m] = [] } }
  # missing variable => [handle_class_module arguments]
  @missing_dependencies = {}
  # missing enclosure variable => [dependent handle_class_module arguments]
  @enclosure_dependencies = Hash.new { |h, k| h[k] = [] }
  @enclosure_dependencies.instance_variable_set :@missing_dependencies,
                                                @missing_dependencies
  @enclosure_dependencies.extend TSort
  def @enclosure_dependencies.tsort_each_node &block
    each_key(&block)
  rescue TSort::Cyclic => e
    cycle_vars = e.message.scan(/"(.*?)"/).flatten
    cycle = cycle_vars.sort.map do |var_name|
      delete var_name
      var_name, type, mod_name, = @missing_dependencies[var_name]
      "#{type} #{mod_name} (#{var_name})"
    end.join ', '
    warn "Unable to create #{cycle} due to a cyclic class or module creation"
    retry
  end
  def @enclosure_dependencies.tsort_each_child node, &block
    fetch(node, []).each(&block)
  end
end

def load_variable_map map_name
  return {} unless files = @store.cache[map_name]
  return {} unless name_map = files[@file_name]
  class_map = {}
  name_map.each do |variable, name|
    next unless mod = @store.find_class_or_module(name)
    class_map[variable] = if map_name == :c_class_variables then
                            mod
                          else
                            name
                          end
    @known_classes[variable] = name
  end
  class_map
end

def look_for_directives_in context, comment
  @preprocess.handle comment, context do |directive, param|
    case directive
    when 'main' then
      @options.main_page = param
      warn <<~MSG
        The :main: directive is deprecated and will be removed in RDoc 7.
        You can use these options to specify the initial page displayed instead:
        - `--main=#{param}` via the command line
        - `rdoc.main = "#{param}"` if you use `RDoc::Task`
        - `main_page: #{param}` in your `.rdoc_options` file
      MSG
      ''
    when 'title' then
      @options.default_title = param if @options.respond_to? :default_title=
      warn <<~MSG
        The :title: directive is deprecated and will be removed in RDoc 7.
        You can use these options to specify the title displayed instead:
        - `--title=#{param}` via the command line
        - `rdoc.title = "#{param}"` if you use `RDoc::Task`
        - `title: #{param}` in your `.rdoc_options` file
      MSG
      ''
    end
  end
  comment
end

def new_comment text = nil, location = nil, language = nil
  RDoc::Comment.new(text, location, language).tap do |comment|
    comment.format = @markup
  end
end

def rb_scan_args method_body
  method_body =~ /rb_scan_args\((.*?)\)/m
  return '(*args)' unless $1
  $1.split(/,/)[2] =~ /"(.*?)"/ # format argument
  format = $1.split(//)
  lead = opt = trail = 0
  if format.first =~ /\d/ then
    lead = $&.to_i
    format.shift
    if format.first =~ /\d/ then
      opt = $&.to_i
      format.shift
      if format.first =~ /\d/ then
        trail = $&.to_i
        format.shift
        block_arg = true
      end
    end
  end
  if format.first == '*' and not block_arg then
    var = true
    format.shift
    if format.first =~ /\d/ then
      trail = $&.to_i
      format.shift
    end
  end
  if format.first == ':' then
    hash = true
    format.shift
  end
  if format.first == '&' then
    block = true
    format.shift
  end
  # if the format string is not empty there's a bug in the C code, ignore it
  args = []
  position = 1
  (1...(position + lead)).each do |index|
    args << "p#{index}"
  end
  position += lead
  (position...(position + opt)).each do |index|
    args << "p#{index} = v#{index}"
  end
  position += opt
  if var then
    args << '*args'
    position += 1
  end
  (position...(position + trail)).each do |index|
    args << "p#{index}"
  end
  position += trail
  if hash then
    args << "p#{position} = {}"
  end
  args << '&block' if block
  "(#{args.join ', '})"
end

def remove_commented_out_lines
  @content = @content.gsub(%r%//.*rb_define_%, '//')
end

def scan
  remove_commented_out_lines
  do_classes_and_modules
  do_missing
  do_constants
  do_methods
  do_includes
  do_aliases
  do_attrs
  @store.add_c_variables self
  @top_level
end