summaryrefslogtreecommitdiff
path: root/lib/racc/parser.rb
blob: a7408dd00a901366575699c0b6744ac865719937 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
#
# $originalId: parser.rb,v 1.8 2006/07/06 11:42:07 aamine Exp $
#
# Copyright (c) 1999-2006 Minero Aoki
#
# This program is free software.
# You can distribute/modify this program under the same terms of ruby.
#
# As a special exception, when this code is copied by Racc
# into a Racc output file, you may use that output file
# without restriction.
#

unless defined?(NotImplementedError)
  NotImplementedError = NotImplementError
end

module Racc
  class ParseError < StandardError; end
end
unless defined?(::ParseError)
  ParseError = Racc::ParseError
end

module Racc

  unless defined?(Racc_No_Extentions)
    Racc_No_Extentions = false
  end

  class Parser

    Racc_Runtime_Version = '1.4.5'
    Racc_Runtime_Revision = '$originalRevision: 1.8 $'.split[1]

    Racc_Runtime_Core_Version_R = '1.4.5'
    Racc_Runtime_Core_Revision_R = '$originalRevision: 1.8 $'.split[1]
    begin
      require 'racc/cparse'
    # Racc_Runtime_Core_Version_C  = (defined in extention)
      Racc_Runtime_Core_Revision_C = Racc_Runtime_Core_Id_C.split[2]
      unless new.respond_to?(:_racc_do_parse_c, true)
        raise LoadError, 'old cparse.so'
      end
      if Racc_No_Extentions
        raise LoadError, 'selecting ruby version of racc runtime core'
      end

      Racc_Main_Parsing_Routine    = :_racc_do_parse_c
      Racc_YY_Parse_Method         = :_racc_yyparse_c
      Racc_Runtime_Core_Version    = Racc_Runtime_Core_Version_C
      Racc_Runtime_Core_Revision   = Racc_Runtime_Core_Revision_C
      Racc_Runtime_Type            = 'c'
    rescue LoadError
      Racc_Main_Parsing_Routine    = :_racc_do_parse_rb
      Racc_YY_Parse_Method         = :_racc_yyparse_rb
      Racc_Runtime_Core_Version    = Racc_Runtime_Core_Version_R
      Racc_Runtime_Core_Revision   = Racc_Runtime_Core_Revision_R
      Racc_Runtime_Type            = 'ruby'
    end

    def Parser.racc_runtime_type
      Racc_Runtime_Type
    end

    private

    def _racc_setup
      @yydebug = false unless self.class::Racc_debug_parser
      @yydebug = false unless defined?(@yydebug)
      if @yydebug
        @racc_debug_out = $stderr unless defined?(@racc_debug_out)
        @racc_debug_out ||= $stderr
      end
      arg = self.class::Racc_arg
      arg[13] = true if arg.size < 14
      arg
    end

    def _racc_init_sysvars
      @racc_state  = [0]
      @racc_tstack = []
      @racc_vstack = []

      @racc_t = nil
      @racc_val = nil

      @racc_read_next = true

      @racc_user_yyerror = false
      @racc_error_status = 0
    end

    ###
    ### do_parse
    ###

    def do_parse
      __send__(Racc_Main_Parsing_Routine, _racc_setup(), false)
    end

    def next_token
      raise NotImplementedError, "#{self.class}\#next_token is not defined"
    end

    def _racc_do_parse_rb(arg, in_debug)
      action_table, action_check, action_default, action_pointer,
      goto_table,   goto_check,   goto_default,   goto_pointer,
      nt_base,      reduce_table, token_table,    shift_n,
      reduce_n,     use_result,   * = arg

      _racc_init_sysvars
      tok = act = i = nil
      nerr = 0

      catch(:racc_end_parse) {
        while true
          if i = action_pointer[@racc_state[-1]]
            if @racc_read_next
              if @racc_t != 0   # not EOF
                tok, @racc_val = next_token()
                unless tok      # EOF
                  @racc_t = 0
                else
                  @racc_t = (token_table[tok] or 1)   # error token
                end
                racc_read_token(@racc_t, tok, @racc_val) if @yydebug
                @racc_read_next = false
              end
            end
            i += @racc_t
            unless i >= 0 and
                   act = action_table[i] and
                   action_check[i] == @racc_state[-1]
              act = action_default[@racc_state[-1]]
            end
          else
            act = action_default[@racc_state[-1]]
          end
          while act = _racc_evalact(act, arg)
            ;
          end
        end
      }
    end

    ###
    ### yyparse
    ###

    def yyparse(recv, mid)
      __send__(Racc_YY_Parse_Method, recv, mid, _racc_setup(), true)
    end

    def _racc_yyparse_rb(recv, mid, arg, c_debug)
      action_table, action_check, action_default, action_pointer,
      goto_table,   goto_check,   goto_default,   goto_pointer,
      nt_base,      reduce_table, token_table,    shift_n,
      reduce_n,     use_result,   * = arg

      _racc_init_sysvars
      tok = nil
      act = nil
      i = nil
      nerr = 0

      catch(:racc_end_parse) {
        until i = action_pointer[@racc_state[-1]]
          while act = _racc_evalact(action_default[@racc_state[-1]], arg)
            ;
          end
        end
        recv.__send__(mid) do |tok, val|
          unless tok
            @racc_t = 0
          else
            @racc_t = (token_table[tok] or 1)   # error token
          end
          @racc_val = val
          @racc_read_next = false

          i += @racc_t
          unless i >= 0 and
                 act = action_table[i] and
                 action_check[i] == @racc_state[-1]
            act = action_default[@racc_state[-1]]
          end
          while act = _racc_evalact(act, arg)
            ;
          end

          while not (i = action_pointer[@racc_state[-1]]) or
                not @racc_read_next or
                @racc_t == 0   # $
            unless i and i += @racc_t and
                   i >= 0 and
                   act = action_table[i] and
                   action_check[i] == @racc_state[-1]
              act = action_default[@racc_state[-1]]
            end
            while act = _racc_evalact(act, arg)
              ;
            end
          end
        end
      }
    end

    ###
    ### common
    ###

    def _racc_evalact(act, arg)
      action_table, action_check, action_default, action_pointer,
      goto_table,   goto_check,   goto_default,   goto_pointer,
      nt_base,      reduce_table, token_table,    shift_n,
      reduce_n,     use_result,   * = arg
      nerr = 0   # tmp

      if act > 0 and act < shift_n
        #
        # shift
        #
        if @racc_error_status > 0
          @racc_error_status -= 1 unless @racc_t == 1   # error token
        end
        @racc_vstack.push @racc_val
        @racc_state.push act
        @racc_read_next = true
        if @yydebug
          @racc_tstack.push @racc_t
          racc_shift @racc_t, @racc_tstack, @racc_vstack
        end

      elsif act < 0 and act > -reduce_n
        #
        # reduce
        #
        code = catch(:racc_jump) {
          @racc_state.push _racc_do_reduce(arg, act)
          false
        }
        if code
          case code
          when 1 # yyerror
            @racc_user_yyerror = true   # user_yyerror
            return -reduce_n
          when 2 # yyaccept
            return shift_n
          else
            raise '[Racc Bug] unknown jump code'
          end
        end

      elsif act == shift_n
        #
        # accept
        #
        racc_accept if @yydebug
        throw :racc_end_parse, @racc_vstack[0]

      elsif act == -reduce_n
        #
        # error
        #
        case @racc_error_status
        when 0
          unless arg[21]    # user_yyerror
            nerr += 1
            on_error @racc_t, @racc_val, @racc_vstack
          end
        when 3
          if @racc_t == 0   # is $
            throw :racc_end_parse, nil
          end
          @racc_read_next = true
        end
        @racc_user_yyerror = false
        @racc_error_status = 3
        while true
          if i = action_pointer[@racc_state[-1]]
            i += 1   # error token
            if  i >= 0 and
                (act = action_table[i]) and
                action_check[i] == @racc_state[-1]
              break
            end
          end
          throw :racc_end_parse, nil if @racc_state.size <= 1
          @racc_state.pop
          @racc_vstack.pop
          if @yydebug
            @racc_tstack.pop
            racc_e_pop @racc_state, @racc_tstack, @racc_vstack
          end
        end
        return act

      else
        raise "[Racc Bug] unknown action #{act.inspect}"
      end

      racc_next_state(@racc_state[-1], @racc_state) if @yydebug

      nil
    end

    def _racc_do_reduce(arg, act)
      action_table, action_check, action_default, action_pointer,
      goto_table,   goto_check,   goto_default,   goto_pointer,
      nt_base,      reduce_table, token_table,    shift_n,
      reduce_n,     use_result,   * = arg
      state = @racc_state
      vstack = @racc_vstack
      tstack = @racc_tstack

      i = act * -3
      len       = reduce_table[i]
      reduce_to = reduce_table[i+1]
      method_id = reduce_table[i+2]
      void_array = []

      tmp_t = tstack[-len, len] if @yydebug
      tmp_v = vstack[-len, len]
      tstack[-len, len] = void_array if @yydebug
      vstack[-len, len] = void_array
      state[-len, len]  = void_array

      # tstack must be updated AFTER method call
      if use_result
        vstack.push __send__(method_id, tmp_v, vstack, tmp_v[0])
      else
        vstack.push __send__(method_id, tmp_v, vstack)
      end
      tstack.push reduce_to

      racc_reduce(tmp_t, reduce_to, tstack, vstack) if @yydebug

      k1 = reduce_to - nt_base
      if i = goto_pointer[k1]
        i += state[-1]
        if i >= 0 and (curstate = goto_table[i]) and goto_check[i] == k1
          return curstate
        end
      end
      goto_default[k1]
    end

    def on_error(t, val, vstack)
      raise ParseError, sprintf("\nparse error on value %s (%s)",
                                val.inspect, token_to_str(t) || '?')
    end

    def yyerror
      throw :racc_jump, 1
    end

    def yyaccept
      throw :racc_jump, 2
    end

    def yyerrok
      @racc_error_status = 0
    end

    #
    # for debugging output
    #

    def racc_read_token(t, tok, val)
      @racc_debug_out.print 'read    '
      @racc_debug_out.print tok.inspect, '(', racc_token2str(t), ') '
      @racc_debug_out.puts val.inspect
      @racc_debug_out.puts
    end

    def racc_shift(tok, tstack, vstack)
      @racc_debug_out.puts "shift   #{racc_token2str tok}"
      racc_print_stacks tstack, vstack
      @racc_debug_out.puts
    end

    def racc_reduce(toks, sim, tstack, vstack)
      out = @racc_debug_out
      out.print 'reduce '
      if toks.empty?
        out.print ' <none>'
      else
        toks.each {|t| out.print ' ', racc_token2str(t) }
      end
      out.puts " --> #{racc_token2str(sim)}"
          
      racc_print_stacks tstack, vstack
      @racc_debug_out.puts
    end

    def racc_accept
      @racc_debug_out.puts 'accept'
      @racc_debug_out.puts
    end

    def racc_e_pop(state, tstack, vstack)
      @racc_debug_out.puts 'error recovering mode: pop token'
      racc_print_states state
      racc_print_stacks tstack, vstack
      @racc_debug_out.puts
    end

    def racc_next_state(curstate, state)
      @racc_debug_out.puts  "goto    #{curstate}"
      racc_print_states state
      @racc_debug_out.puts
    end

    def racc_print_stacks(t, v)
      out = @racc_debug_out
      out.print '        ['
      t.each_index do |i|
        out.print ' (', racc_token2str(t[i]), ' ', v[i].inspect, ')'
      end
      out.puts ' ]'
    end

    def racc_print_states(s)
      out = @racc_debug_out
      out.print '        ['
      s.each {|st| out.print ' ', st }
      out.puts ' ]'
    end

    def racc_token2str(tok)
      self.class::Racc_token_to_s_table[tok] or
          raise "[Racc Bug] can't convert token #{tok} to string"
    end

    def token_to_str(t)
      self.class::Racc_token_to_s_table[t]
    end

  end

end