SoundSoftware Code Site

module CodeRay

module Scanners

  # Scanner for C.

  class C < Scanner

    register_for :c

    file_extension 'c'

    KEYWORDS = [

      'asm', 'break', 'case', 'continue', 'default', 'do',

      'else', 'enum', 'for', 'goto', 'if', 'return',

      'sizeof', 'struct', 'switch', 'typedef', 'union', 'while',

      'restrict',  # added in C99

    ]  # :nodoc:

    PREDEFINED_TYPES = [

      'int', 'long', 'short', 'char',

      'signed', 'unsigned', 'float', 'double',

      'bool', 'complex',  # added in C99

    ]  # :nodoc:

    PREDEFINED_CONSTANTS = [

      'EOF', 'NULL',

      'true', 'false',  # added in C99

    ]  # :nodoc:

    DIRECTIVES = [

      'auto', 'extern', 'register', 'static', 'void',

      'const', 'volatile',  # added in C89

      'inline',  # added in C99

    ]  # :nodoc:

    IDENT_KIND = WordList.new(:ident).

      add(KEYWORDS, :keyword).

      add(PREDEFINED_TYPES, :predefined_type).

      add(DIRECTIVES, :directive).

      add(PREDEFINED_CONSTANTS, :predefined_constant)  # :nodoc:

    ESCAPE = / [rbfntv\n\\'"] | x[a-fA-F0-9]{1,2} | [0-7]{1,3} /x  # :nodoc:

    UNICODE_ESCAPE =  / u[a-fA-F0-9]{4} | U[a-fA-F0-9]{8} /x  # :nodoc:

  protected

    def scan_tokens encoder, options

      state = :initial

      label_expected = true

      case_expected = false

      label_expected_before_preproc_line = nil

      in_preproc_line = false

      until eos?

        case state

        when :initial

          if match = scan(/ \s+ | \\\n /x)

            if in_preproc_line && match != "\\\n" && match.index(?\n)

              in_preproc_line = false

              label_expected = label_expected_before_preproc_line

            end

            encoder.text_token match, :space

          elsif match = scan(%r! // [^\n\\]* (?: \\. [^\n\\]* )* | /\* (?: .*? \*/ | .* ) !mx)

            encoder.text_token match, :comment

          elsif match = scan(/ [-+*=<>?:;,!&^|()\[\]{}~%]+ | \/=? | \.(?!\d) /x)

            label_expected = match =~ /[;\{\}]/

            if case_expected

              label_expected = true if match == ':'

              case_expected = false

            end

            encoder.text_token match, :operator

          elsif match = scan(/ [A-Za-z_][A-Za-z_0-9]* /x)

            kind = IDENT_KIND[match]

            if kind == :ident && label_expected && !in_preproc_line && scan(/:(?!:)/)

              kind = :label

              match << matched

            else

              label_expected = false

              if kind == :keyword

                case match

                when 'case', 'default'

                  case_expected = true

                end

              end

            end

            encoder.text_token match, kind

          elsif match = scan(/L?"/)

            encoder.begin_group :string

            if match[0] == ?L

              encoder.text_token 'L', :modifier

              match = '"'

            end

            encoder.text_token match, :delimiter

            state = :string

          elsif match = scan(/ \# \s* if \s* 0 /x)

            match << scan_until(/ ^\# (?:elif|else|endif) .*? $ | \z /xm) unless eos?

            encoder.text_token match, :comment

          elsif match = scan(/#[ \t]*(\w*)/)

            encoder.text_token match, :preprocessor

            in_preproc_line = true

            label_expected_before_preproc_line = label_expected

            state = :include_expected if self[1] == 'include'

          elsif match = scan(/ L?' (?: [^\'\n\\] | \\ #{ESCAPE} )? '? /ox)

            label_expected = false

            encoder.text_token match, :char

          elsif match = scan(/\$/)

            encoder.text_token match, :ident

          elsif match = scan(/0[xX][0-9A-Fa-f]+/)

            label_expected = false

            encoder.text_token match, :hex

          elsif match = scan(/(?:0[0-7]+)(?![89.eEfF])/)

            label_expected = false

            encoder.text_token match, :octal

          elsif match = scan(/(?:\d+)(?![.eEfF])L?L?/)

            label_expected = false

            encoder.text_token match, :integer

          elsif match = scan(/\d[fF]?|\d*\.\d+(?:[eE][+-]?\d+)?[fF]?|\d+[eE][+-]?\d+[fF]?/)

            label_expected = false

            encoder.text_token match, :float

          else

            encoder.text_token getch, :error

          end

        when :string

          if match = scan(/[^\\\n"]+/)

            encoder.text_token match, :content

          elsif match = scan(/"/)

            encoder.text_token match, :delimiter

            encoder.end_group :string

            state = :initial

            label_expected = false

          elsif match = scan(/ \\ (?: #{ESCAPE} | #{UNICODE_ESCAPE} ) /mox)

            encoder.text_token match, :char

          elsif match = scan(/ \\ | $ /x)

            encoder.end_group :string

            encoder.text_token match, :error

            state = :initial

            label_expected = false

          else

            raise_inspect "else case \" reached; %p not handled." % peek(1), encoder

          end

        when :include_expected

          if match = scan(/<[^>\n]+>?|"[^"\n\\]*(?:\\.[^"\n\\]*)*"?/)

            encoder.text_token match, :include

            state = :initial

          elsif match = scan(/\s+/)

            encoder.text_token match, :space

            state = :initial if match.index ?\n

          else

            state = :initial

          end

        else

          raise_inspect 'Unknown state', encoder

        end

      end

      if state == :string

        encoder.end_group :string

      end

      encoder

    end

  end

end

end