Backport racc-1.4.15 from upstream.

1 files changed, 559 insertions, 0 deletions

diff --git a/lib/racc/grammarfileparser.rb b/lib/racc/grammarfileparser.rb
new file mode 100644
index 0000000000..7548a9ea37
--- /dev/null
+++ b/lib/racc/grammarfileparser.rb
@@ -0,0 +1,559 @@
+#
+# $Id: 5e1871defa15d288d2252e6a76bb2c4cf2119ed3 $
+#
+# Copyright (c) 1999-2006 Minero Aoki
+#
+# This program is free software.
+# You can distribute/modify this program under the terms of
+# the GNU LGPL, Lesser General Public License version 2.1.
+# For details of the GNU LGPL, see the file "COPYING".
+#
+
+require 'racc'
+require 'racc/compat'
+require 'racc/grammar'
+require 'racc/parserfilegenerator'
+require 'racc/sourcetext'
+require 'stringio'
+
+module Racc
+
+  grammar = Grammar.define {
+    g = self
+
+    g.class = seq(:CLASS, :cname, many(:param), :RULE, :rules, option(:END))
+
+    g.cname       = seq(:rubyconst) {|name|
+                      @result.params.classname = name
+                    }\
+                  | seq(:rubyconst, "<", :rubyconst) {|c, _, s|
+                      @result.params.classname = c
+                      @result.params.superclass = s
+                    }
+
+    g.rubyconst   = separated_by1(:colon2, :SYMBOL) {|syms|
+                      syms.map {|s| s.to_s }.join('::')
+                    }
+
+    g.colon2 = seq(':', ':')
+
+    g.param       = seq(:CONV, many1(:convdef), :END) {|*|
+                      #@grammar.end_convert_block   # FIXME
+                    }\
+                  | seq(:PRECHIGH, many1(:precdef), :PRECLOW) {|*|
+                      @grammar.end_precedence_declaration true
+                    }\
+                  | seq(:PRECLOW, many1(:precdef), :PRECHIGH) {|*|
+                      @grammar.end_precedence_declaration false
+                    }\
+                  | seq(:START, :symbol) {|_, sym|
+                      @grammar.start_symbol = sym
+                    }\
+                  | seq(:TOKEN, :symbols) {|_, syms|
+                      syms.each do |s|
+                        s.should_terminal
+                      end
+                    }\
+                  | seq(:OPTION, :options) {|_, syms|
+                      syms.each do |opt|
+                        case opt
+                        when 'result_var'
+                          @result.params.result_var = true
+                        when 'no_result_var'
+                          @result.params.result_var = false
+                        when 'omit_action_call'
+                          @result.params.omit_action_call = true
+                        when 'no_omit_action_call'
+                          @result.params.omit_action_call = false
+                        else
+                          raise CompileError, "unknown option: #{opt}"
+                        end
+                      end
+                    }\
+                  | seq(:EXPECT, :DIGIT) {|_, num|
+                      if @grammar.n_expected_srconflicts
+                        raise CompileError, "`expect' seen twice"
+                      end
+                      @grammar.n_expected_srconflicts = num
+                    }
+
+    g.convdef     = seq(:symbol, :STRING) {|sym, code|
+                      sym.serialized = code
+                    }
+
+    g.precdef     = seq(:LEFT, :symbols) {|_, syms|
+                      @grammar.declare_precedence :Left, syms
+                    }\
+                  | seq(:RIGHT, :symbols) {|_, syms|
+                      @grammar.declare_precedence :Right, syms
+                    }\
+                  | seq(:NONASSOC, :symbols) {|_, syms|
+                      @grammar.declare_precedence :Nonassoc, syms
+                    }
+
+    g.symbols     = seq(:symbol) {|sym|
+                      [sym]
+                    }\
+                  | seq(:symbols, :symbol) {|list, sym|
+                      list.push sym
+                      list
+                    }\
+                  | seq(:symbols, "|")
+
+    g.symbol      = seq(:SYMBOL) {|sym| @grammar.intern(sym) }\
+                  | seq(:STRING) {|str| @grammar.intern(str) }
+
+    g.options     = many(:SYMBOL) {|syms| syms.map {|s| s.to_s } }
+
+    g.rules       = option(:rules_core) {|list|
+                      add_rule_block list  unless list.empty?
+                      nil
+                    }
+
+    g.rules_core  = seq(:symbol) {|sym|
+                      [sym]
+                    }\
+                  | seq(:rules_core, :rule_item) {|list, i|
+                      list.push i
+                      list
+                    }\
+                  | seq(:rules_core, ';') {|list, *|
+                      add_rule_block list  unless list.empty?
+                      list.clear
+                      list
+                    }\
+                  | seq(:rules_core, ':') {|list, *|
+                      next_target = list.pop
+                      add_rule_block list  unless list.empty?
+                      [next_target]
+                    }
+
+    g.rule_item   = seq(:symbol)\
+                  | seq("|") {|*|
+                      OrMark.new(@scanner.lineno)
+                    }\
+                  | seq("=", :symbol) {|_, sym|
+                      Prec.new(sym, @scanner.lineno)
+                    }\
+                  | seq(:ACTION) {|src|
+                      UserAction.source_text(src)
+                    }
+  }
+
+  GrammarFileParser = grammar.parser_class
+
+  if grammar.states.srconflict_exist?
+    raise 'Racc boot script fatal: S/R conflict in build'
+  end
+  if grammar.states.rrconflict_exist?
+    raise 'Racc boot script fatal: R/R conflict in build'
+  end
+
+  class GrammarFileParser   # reopen
+
+    class Result
+      def initialize(grammar)
+        @grammar = grammar
+        @params = ParserFileGenerator::Params.new
+      end
+
+      attr_reader :grammar
+      attr_reader :params
+    end
+
+    def GrammarFileParser.parse_file(filename)
+      parse(File.read(filename), filename, 1)
+    end
+
+    def GrammarFileParser.parse(src, filename = '-', lineno = 1)
+      new().parse(src, filename, lineno)
+    end
+
+    def initialize(debug_flags = DebugFlags.new)
+      @yydebug = debug_flags.parse
+    end
+
+    def parse(src, filename = '-', lineno = 1)
+      @filename = filename
+      @lineno = lineno
+      @scanner = GrammarFileScanner.new(src, @filename)
+      @scanner.debug = @yydebug
+      @grammar = Grammar.new
+      @result = Result.new(@grammar)
+      @embedded_action_seq = 0
+      yyparse @scanner, :yylex
+      parse_user_code
+      @result.grammar.init
+      @result
+    end
+
+    private
+
+    def next_token
+      @scanner.scan
+    end
+
+    def on_error(tok, val, _values)
+      if val.respond_to?(:id2name)
+        v = val.id2name
+      elsif val.kind_of?(String)
+        v = val
+      else
+        v = val.inspect
+      end
+      raise CompileError, "#{location()}: unexpected token '#{v}'"
+    end
+
+    def location
+      "#{@filename}:#{@lineno - 1 + @scanner.lineno}"
+    end
+
+    def add_rule_block(list)
+      sprec = nil
+      target = list.shift
+      case target
+      when OrMark, UserAction, Prec
+        raise CompileError, "#{target.lineno}: unexpected symbol #{target.name}"
+      end
+      curr = []
+      list.each do |i|
+        case i
+        when OrMark
+          add_rule target, curr, sprec
+          curr = []
+          sprec = nil
+        when Prec
+          raise CompileError, "'=<prec>' used twice in one rule" if sprec
+          sprec = i.symbol
+        else
+          curr.push i
+        end
+      end
+      add_rule target, curr, sprec
+    end
+
+    def add_rule(target, list, sprec)
+      if list.last.kind_of?(UserAction)
+        act = list.pop
+      else
+        act = UserAction.empty
+      end
+      list.map! {|s| s.kind_of?(UserAction) ? embedded_action(s) : s }
+      rule = Rule.new(target, list, act)
+      rule.specified_prec = sprec
+      @grammar.add rule
+    end
+
+    def embedded_action(act)
+      sym = @grammar.intern("@#{@embedded_action_seq += 1}".intern, true)
+      @grammar.add Rule.new(sym, [], act)
+      sym
+    end
+
+    #
+    # User Code Block
+    #
+
+    def parse_user_code
+      line = @scanner.lineno
+      _, *blocks = *@scanner.epilogue.split(/^----/)
+      blocks.each do |block|
+        header, *body = block.lines.to_a
+        label0, pathes = *header.sub(/\A-+/, '').split('=', 2)
+        label = canonical_label(label0)
+        (pathes ? pathes.strip.split(' ') : []).each do |path|
+          add_user_code label, SourceText.new(File.read(path), path, 1)
+        end
+        add_user_code label, SourceText.new(body.join(''), @filename, line + 1)
+        line += (1 + body.size)
+      end
+    end
+
+    USER_CODE_LABELS = {
+      'header'  => :header,
+      'prepare' => :header,   # obsolete
+      'inner'   => :inner,
+      'footer'  => :footer,
+      'driver'  => :footer    # obsolete
+    }
+
+    def canonical_label(src)
+      label = src.to_s.strip.downcase.slice(/\w+/)
+      unless USER_CODE_LABELS.key?(label)
+        raise CompileError, "unknown user code type: #{label.inspect}"
+      end
+      label
+    end
+    
+    def add_user_code(label, src)
+      @result.params.send(USER_CODE_LABELS[label]).push src
+    end
+
+  end
+
+
+  class GrammarFileScanner
+
+    def initialize(str, filename = '-')
+      @lines  = str.split(/\n|\r\n|\r/)
+      @filename = filename
+      @lineno = -1
+      @line_head   = true
+      @in_rule_blk = false
+      @in_conv_blk = false
+      @in_block = nil
+      @epilogue = ''
+      @debug = false
+      next_line
+    end
+
+    attr_reader :epilogue
+
+    def lineno
+      @lineno + 1
+    end
+
+    attr_accessor :debug
+
+    def yylex(&block)
+      unless @debug
+        yylex0(&block)
+      else
+        yylex0 do |sym, tok|
+          $stderr.printf "%7d %-10s %s\n", lineno(), sym.inspect, tok.inspect
+          yield [sym, tok]
+        end
+      end
+    end
+
+    private
+
+    def yylex0
+      begin
+        until @line.empty?
+          @line.sub!(/\A\s+/, '')
+          if /\A\#/ =~ @line
+            break
+          elsif /\A\/\*/ =~ @line
+            skip_comment
+          elsif s = reads(/\A[a-zA-Z_]\w*/)
+            yield [atom_symbol(s), s.intern]
+          elsif s = reads(/\A\d+/)
+            yield [:DIGIT, s.to_i]
+          elsif ch = reads(/\A./)
+            case ch
+            when '"', "'"
+              yield [:STRING, eval(scan_quoted(ch))]
+            when '{'
+              lineno = lineno()
+              yield [:ACTION, SourceText.new(scan_action(), @filename, lineno)]
+            else
+              if ch == '|'
+                @line_head = false
+              end
+              yield [ch, ch]
+            end
+          else
+          end
+        end
+      end while next_line()
+      yield nil
+    end
+
+    def next_line
+      @lineno += 1
+      @line = @lines[@lineno]
+      if not @line or /\A----/ =~ @line
+        @epilogue = @lines.join("\n")
+        @lines.clear
+        @line = nil
+        if @in_block
+          @lineno -= 1
+          scan_error! sprintf('unterminated %s', @in_block)
+        end
+        false
+      else
+        @line.sub!(/(?:\n|\r\n|\r)\z/, '')
+        @line_head = true
+        true
+      end
+    end
+
+    ReservedWord = {
+      'right'    => :RIGHT,
+      'left'     => :LEFT,
+      'nonassoc' => :NONASSOC,
+      'preclow'  => :PRECLOW,
+      'prechigh' => :PRECHIGH,
+      'token'    => :TOKEN,
+      'convert'  => :CONV,
+      'options'  => :OPTION,
+      'start'    => :START,
+      'expect'   => :EXPECT,
+      'class'    => :CLASS,
+      'rule'     => :RULE,
+      'end'      => :END
+    }
+
+    def atom_symbol(token)
+      if token == 'end'
+        symbol = :END
+        @in_conv_blk = false
+        @in_rule_blk = false
+      else
+        if @line_head and not @in_conv_blk and not @in_rule_blk
+          symbol = ReservedWord[token] || :SYMBOL
+        else
+          symbol = :SYMBOL
+        end
+        case symbol
+        when :RULE then @in_rule_blk = true
+        when :CONV then @in_conv_blk = true
+        end
+      end
+      @line_head = false
+      symbol
+    end
+
+    def skip_comment
+      @in_block = 'comment'
+      until m = /\*\//.match(@line)
+        next_line
+      end
+      @line = m.post_match
+      @in_block = nil
+    end
+
+    $raccs_print_type = false
+
+    def scan_action
+      buf = ''
+      nest = 1
+      pre = nil
+      @in_block = 'action'
+      begin
+        pre = nil
+        if s = reads(/\A\s+/)
+          # does not set 'pre'
+          buf << s
+        end
+        until @line.empty?
+          if s = reads(/\A[^'"`{}%#\/\$]+/)
+            buf << (pre = s)
+            next
+          end
+          case ch = read(1)
+          when '{'
+            nest += 1
+            buf << (pre = ch)
+          when '}'
+            nest -= 1
+            if nest == 0
+              @in_block = nil
+              return buf
+            end
+            buf << (pre = ch)
+          when '#'   # comment
+            buf << ch << @line
+            break
+          when "'", '"', '`'
+            buf << (pre = scan_quoted(ch))
+          when '%'
+            if literal_head? pre, @line
+              # % string, regexp, array
+              buf << ch
+              case ch = read(1)
+              when /[qQx]/n
+                buf << ch << (pre = scan_quoted(read(1), '%string'))
+              when /wW/n
+                buf << ch << (pre = scan_quoted(read(1), '%array'))
+              when /s/n
+                buf << ch << (pre = scan_quoted(read(1), '%symbol'))
+              when /r/n
+                buf << ch << (pre = scan_quoted(read(1), '%regexp'))
+              when /[a-zA-Z0-9= ]/n   # does not include "_"
+                scan_error! "unknown type of % literal '%#{ch}'"
+              else
+                buf << (pre = scan_quoted(ch, '%string'))
+              end
+            else
+              # operator
+              buf << '||op->' if $raccs_print_type
+              buf << (pre = ch)
+            end
+          when '/'
+            if literal_head? pre, @line
+              # regexp
+              buf << (pre = scan_quoted(ch, 'regexp'))
+            else
+              # operator
+              buf << '||op->' if $raccs_print_type
+              buf << (pre = ch)
+            end
+          when '$'   # gvar
+            buf << ch << (pre = read(1))
+          else
+            raise 'racc: fatal: must not happen'
+          end
+        end
+        buf << "\n"
+      end while next_line()
+      raise 'racc: fatal: scan finished before parser finished'
+    end
+
+    def literal_head?(pre, post)
+      (!pre || /[a-zA-Z_0-9]/n !~ pre[-1,1]) &&
+          !post.empty? && /\A[\s\=]/n !~ post
+    end
+
+    def read(len)
+      s = @line[0, len]
+      @line = @line[len .. -1]
+      s
+    end
+
+    def reads(re)
+      m = re.match(@line) or return nil
+      @line = m.post_match
+      m[0]
+    end
+
+    def scan_quoted(left, tag = 'string')
+      buf = left.dup
+      buf = "||#{tag}->" + buf if $raccs_print_type
+      re = get_quoted_re(left)
+      sv, @in_block = @in_block, tag
+      begin
+        if s = reads(re)
+          buf << s
+          break
+        else
+          buf << @line
+        end
+      end while next_line()
+      @in_block = sv
+      buf << "<-#{tag}||" if $raccs_print_type
+      buf
+    end
+
+    LEFT_TO_RIGHT = {
+      '(' => ')',
+      '{' => '}',
+      '[' => ']',
+      '<' => '>'
+    }
+
+    CACHE = {}
+
+    def get_quoted_re(left)
+      term = Regexp.quote(LEFT_TO_RIGHT[left] || left)
+      CACHE[left] ||= /\A[^#{term}\\]*(?:\\.[^\\#{term}]*)*#{term}/
+    end
+
+    def scan_error!(msg)
+      raise CompileError, "#{lineno()}: #{msg}"
+    end
+
+  end
+
+end   # module Racc