Source code: java_cup/emit.java
1 package java_cup;
2
3 import java.io.PrintWriter;
4 import java.util.Stack;
5 import java.util.Enumeration;
6 import java.util.Date;
7
8 /**
9 * This class handles emitting generated code for the resulting parser.
10 * The various parse tables must be constructed, etc. before calling any
11 * routines in this class.<p>
12 *
13 * Three classes are produced by this code:
14 * <dl>
15 * <dt> symbol constant class
16 * <dd> this contains constant declarations for each terminal (and
17 * optionally each non-terminal).
18 * <dt> action class
19 * <dd> this non-public class contains code to invoke all the user actions
20 * that were embedded in the parser specification.
21 * <dt> parser class
22 * <dd> the specialized parser class consisting primarily of some user
23 * supplied general and initialization code, and the parse tables.
24 * </dl><p>
25 *
26 * Three parse tables are created as part of the parser class:
27 * <dl>
28 * <dt> production table
29 * <dd> lists the LHS non terminal number, and the length of the RHS of
30 * each production.
31 * <dt> action table
32 * <dd> for each state of the parse machine, gives the action to be taken
33 * (shift, reduce, or error) under each lookahead symbol.<br>
34 * <dt> reduce-goto table
35 * <dd> when a reduce on a given production is taken, the parse stack is
36 * popped back a number of elements corresponding to the RHS of the
37 * production. This reveals a prior state, which we transition out
38 * of under the LHS non terminal symbol for the production (as if we
39 * had seen the LHS symbol rather than all the symbols matching the
40 * RHS). This table is indexed by non terminal numbers and indicates
41 * how to make these transitions.
42 * </dl><p>
43 *
44 * In addition to the method interface, this class maintains a series of
45 * public global variables and flags indicating how misc. parts of the code
46 * and other output is to be produced, and counting things such as number of
47 * conflicts detected (see the source code and public variables below for
48 * more details).<p>
49 *
50 * This class is "static" (contains only static data and methods).<p>
51 *
52 * @see java_cup.main
53 * @version last update: 11/25/95
54 * @author Scott Hudson
55 */
56
57 /* Major externally callable routines here include:
58 symbols - emit the symbol constant class
59 parser - emit the parser class
60
61 In addition the following major internal routines are provided:
62 emit_package - emit a package declaration
63 emit_action_code - emit the class containing the user's actions
64 emit_production_table - emit declaration and init for the production table
65 do_action_table - emit declaration and init for the action table
66 do_reduce_table - emit declaration and init for the reduce-goto table
67
68 Finally, this class uses a number of public instance variables to communicate
69 optional parameters and flags used to control how code is generated,
70 as well as to report counts of various things (such as number of conflicts
71 detected). These include:
72
73 prefix - a prefix string used to prefix names that would
74 otherwise "pollute" someone else's name space.
75 package_name - name of the package emitted code is placed in
76 (or null for an unnamed package.
77 symbol_const_class_name - name of the class containing symbol constants.
78 parser_class_name - name of the class for the resulting parser.
79 action_code - user supplied declarations and other code to be
80 placed in action class.
81 parser_code - user supplied declarations and other code to be
82 placed in parser class.
83 init_code - user supplied code to be executed as the parser
84 is being initialized.
85 scan_code - user supplied code to get the next Symbol.
86 start_production - the start production for the grammar.
87 import_list - list of imports for use with action class.
88 num_conflicts - number of conflicts detected.
89 nowarn - true if we are not to issue warning messages.
90 not_reduced - count of number of productions that never reduce.
91 unused_term - count of unused terminal symbols.
92 unused_non_term - count of unused non terminal symbols.
93 *_time - a series of symbols indicating how long various
94 sub-parts of code generation took (used to produce
95 optional time reports in main).
96 */
97
98 public class emit {
99
100 /*-----------------------------------------------------------*/
101 /*--- Constructor(s) ----------------------------------------*/
102 /*-----------------------------------------------------------*/
103
104 /** Only constructor is private so no instances can be created. */
105 private emit() { }
106
107 /*-----------------------------------------------------------*/
108 /*--- Static (Class) Variables ------------------------------*/
109 /*-----------------------------------------------------------*/
110
111 /** The prefix placed on names that pollute someone else's name space. */
112 public static String prefix = "CUP$";
113
114 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
115
116 /** Package that the resulting code goes into (null is used for unnamed). */
117 public static String package_name = null;
118
119 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
120
121 /** Name of the generated class for symbol constants. */
122 public static String symbol_const_class_name = "sym";
123
124 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
125
126 /** Name of the generated parser class. */
127 public static String parser_class_name = "parser";
128
129 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
130
131 /** User declarations for direct inclusion in user action class. */
132 public static String action_code = null;
133
134 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
135
136 /** User declarations for direct inclusion in parser class. */
137 public static String parser_code = null;
138
139 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
140
141 /** User code for user_init() which is called during parser initialization. */
142 public static String init_code = null;
143
144 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
145
146 /** User code for scan() which is called to get the next Symbol. */
147 public static String scan_code = null;
148
149 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
150
151 /** The start production of the grammar. */
152 public static production start_production = null;
153
154 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
155
156 /** List of imports (Strings containing class names) to go with actions. */
157 public static Stack import_list = new Stack();
158
159 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
160
161 /** Number of conflict found while building tables. */
162 public static int num_conflicts = 0;
163
164 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
165
166 /** Do we skip warnings? */
167 public static boolean nowarn = false;
168
169 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
170
171 /** Count of the number on non-reduced productions found. */
172 public static int not_reduced = 0;
173
174 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
175
176 /** Count of unused terminals. */
177 public static int unused_term = 0;
178
179 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
180
181 /** Count of unused non terminals. */
182 public static int unused_non_term = 0;
183
184 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
185
186 /* Timing values used to produce timing report in main.*/
187
188 /** Time to produce symbol constant class. */
189 public static long symbols_time = 0;
190
191 /** Time to produce parser class. */
192 public static long parser_time = 0;
193
194 /** Time to produce action code class. */
195 public static long action_code_time = 0;
196
197 /** Time to produce the production table. */
198 public static long production_table_time = 0;
199
200 /** Time to produce the action table. */
201 public static long action_table_time = 0;
202
203 /** Time to produce the reduce-goto table. */
204 public static long goto_table_time = 0;
205
206 /* frankf 6/18/96 */
207 protected static boolean _lr_values;
208
209 /** whether or not to emit code for left and right values */
210 public static boolean lr_values() {return _lr_values;}
211 protected static void set_lr_values(boolean b) { _lr_values = b;}
212
213 /*-----------------------------------------------------------*/
214 /*--- General Methods ---------------------------------------*/
215 /*-----------------------------------------------------------*/
216
217 /** Build a string with the standard prefix.
218 * @param str string to prefix.
219 */
220 protected static String pre(String str) {
221 return prefix + parser_class_name + "$" + str;
222 }
223
224 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
225
226 /** Emit a package spec if the user wants one.
227 * @param out stream to produce output on.
228 */
229 protected static void emit_package(PrintWriter out)
230 {
231 /* generate a package spec if we have a name for one */
232 if (package_name != null) {
233 out.println("package " + package_name + ";"); out.println();
234 }
235 }
236
237 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
238
239 /** Emit code for the symbol constant class, optionally including non terms,
240 * if they have been requested.
241 * @param out stream to produce output on.
242 * @param emit_non_terms do we emit constants for non terminals?
243 * @param sym_interface should we emit an interface, rather than a class?
244 */
245 public static void symbols(PrintWriter out,
246 boolean emit_non_terms, boolean sym_interface)
247 {
248 terminal term;
249 non_terminal nt;
250 String class_or_interface = (sym_interface)?"interface":"class";
251
252 long start_time = System.currentTimeMillis();
253
254 /* top of file */
255 out.println();
256 out.println("//----------------------------------------------------");
257 out.println("// The following code was generated by " +
258 version.title_str);
259 out.println("// " + new Date());
260 out.println("//----------------------------------------------------");
261 out.println();
262 emit_package(out);
263
264 /* class header */
265 out.println("/** CUP generated " + class_or_interface +
266 " containing symbol constants. */");
267 out.println("public " + class_or_interface + " " +
268 symbol_const_class_name + " {");
269
270 out.println(" /* terminals */");
271
272 /* walk over the terminals */ /* later might sort these */
273 for (Enumeration e = terminal.all(); e.hasMoreElements(); )
274 {
275 term = (terminal)e.nextElement();
276
277 /* output a constant decl for the terminal */
278 out.println(" public static final int " + term.name() + " = " +
279 term.index() + ";");
280 }
281
282 /* do the non terminals if they want them (parser doesn't need them) */
283 if (emit_non_terms)
284 {
285 out.println();
286 out.println(" /* non terminals */");
287
288 /* walk over the non terminals */ /* later might sort these */
289 for (Enumeration e = non_terminal.all(); e.hasMoreElements(); )
290 {
291 nt = (non_terminal)e.nextElement();
292
293 /* output a constant decl for the terminal */
294 out.println(" static final int " + nt.name() + " = " +
295 nt.index() + ";");
296 }
297 }
298
299 /* end of class */
300 out.println("}");
301 out.println();
302
303 symbols_time = System.currentTimeMillis() - start_time;
304 }
305
306 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
307
308 /** Emit code for the non-public class holding the actual action code.
309 * @param out stream to produce output on.
310 * @param start_prod the start production of the grammar.
311 */
312 protected static void emit_action_code(PrintWriter out, production start_prod)
313 throws internal_error
314 {
315 production prod;
316
317 long start_time = System.currentTimeMillis();
318
319 /* class header */
320 out.println();
321 out.println(
322 "/** Cup generated class to encapsulate user supplied action code.*/"
323 );
324 out.println("class " + pre("actions") + " {");
325
326 /* user supplied code */
327 if (action_code != null)
328 {
329 out.println();
330 out.println(action_code);
331 }
332
333 /* field for parser object */
334 out.println(" private final "+parser_class_name+" parser;");
335
336 /* constructor */
337 out.println();
338 out.println(" /** Constructor */");
339 out.println(" " + pre("actions") + "("+parser_class_name+" parser) {");
340 out.println(" this.parser = parser;");
341 out.println(" }");
342
343 /* action method head */
344 out.println();
345 out.println(" /** Method with the actual generated action code. */");
346 out.println(" public final java_cup.runtime.Symbol " +
347 pre("do_action") + "(");
348 out.println(" int " + pre("act_num,"));
349 out.println(" java_cup.runtime.lr_parser " + pre("parser,"));
350 out.println(" java.util.Stack " + pre("stack,"));
351 out.println(" int " + pre("top)"));
352 out.println(" throws java.lang.Exception");
353 out.println(" {");
354
355 /* declaration of result symbol */
356 /* New declaration!! now return Symbol
357 6/13/96 frankf */
358 out.println(" /* Symbol object for return from actions */");
359 out.println(" java_cup.runtime.Symbol " + pre("result") + ";");
360 out.println();
361
362 /* switch top */
363 out.println(" /* select the action based on the action number */");
364 out.println(" switch (" + pre("act_num") + ")");
365 out.println(" {");
366
367 /* emit action code for each production as a separate case */
368 for (Enumeration p = production.all(); p.hasMoreElements(); )
369 {
370 prod = (production)p.nextElement();
371
372 /* case label */
373 out.println(" /*. . . . . . . . . . . . . . . . . . . .*/");
374 out.println(" case " + prod.index() + ": // " +
375 prod.to_simple_string());
376
377 /* give them their own block to work in */
378 out.println(" {");
379
380 /* create the result symbol */
381 /*make the variable RESULT which will point to the new Symbol (see below)
382 and be changed by action code
383 6/13/96 frankf */
384 out.println(" " + prod.lhs().the_symbol().stack_type() +
385 " RESULT = null;");
386
387 /* Add code to propagate RESULT assignments that occur in
388 * action code embedded in a production (ie, non-rightmost
389 * action code). 24-Mar-1998 CSA
390 */
391 for (int i=0; i<prod.rhs_length(); i++) {
392 // only interested in non-terminal symbols.
393 if (!(prod.rhs(i) instanceof symbol_part)) continue;
394 symbol s = ((symbol_part)prod.rhs(i)).the_symbol();
395 if (!(s instanceof non_terminal)) continue;
396 // skip this non-terminal unless it corresponds to
397 // an embedded action production.
398 if (((non_terminal)s).is_embedded_action == false) continue;
399 // OK, it fits. Make a conditional assignment to RESULT.
400 int index = prod.rhs_length() - i - 1; // last rhs is on top.
401 out.println(" " + "// propagate RESULT from " +
402 s.name());
403 out.println(" " + "if ( " +
404 "((java_cup.runtime.Symbol) " + emit.pre("stack") + ".elementAt("
405 + emit.pre("top") + "-" + index + ")).value != null )");
406 out.println(" " + "RESULT = " +
407 "(" + prod.lhs().the_symbol().stack_type() + ") " +
408 "((java_cup.runtime.Symbol) " + emit.pre("stack") + ".elementAt("
409 + emit.pre("top") + "-" + index + ")).value;");
410 }
411
412 /* if there is an action string, emit it */
413 if (prod.action() != null && prod.action().code_string() != null &&
414 !prod.action().equals(""))
415 out.println(prod.action().code_string());
416
417 /* here we have the left and right values being propagated.
418 must make this a command line option.
419 frankf 6/18/96 */
420
421 /* Create the code that assigns the left and right values of
422 the new Symbol that the production is reducing to */
423 if (emit.lr_values()) {
424 int loffset;
425 String leftstring, rightstring;
426 int roffset = 0;
427 rightstring = "((java_cup.runtime.Symbol)" + emit.pre("stack") + ".elementAt(" +
428 emit.pre("top") + "-" + roffset + ")).right";
429 if (prod.rhs_length() == 0)
430 leftstring = rightstring;
431 else {
432 loffset = prod.rhs_length() - 1;
433 leftstring = "((java_cup.runtime.Symbol)" + emit.pre("stack") + ".elementAt(" +
434 emit.pre("top") + "-" + loffset + ")).left";
435 }
436 out.println(" " + pre("result") + " = new java_cup.runtime.Symbol(" +
437 prod.lhs().the_symbol().index() + "/*" +
438 prod.lhs().the_symbol().name() + "*/" +
439 ", " + leftstring + ", " + rightstring + ", RESULT);");
440 } else {
441 out.println(" " + pre("result") + " = new java_cup.runtime.Symbol(" +
442 prod.lhs().the_symbol().index() + "/*" +
443 prod.lhs().the_symbol().name() + "*/" +
444 ", RESULT);");
445 }
446
447 /* end of their block */
448 out.println(" }");
449
450 /* if this was the start production, do action for accept */
451 if (prod == start_prod)
452 {
453 out.println(" /* ACCEPT */");
454 out.println(" " + pre("parser") + ".done_parsing();");
455 }
456
457 /* code to return lhs symbol */
458 out.println(" return " + pre("result") + ";");
459 out.println();
460 }
461
462 /* end of switch */
463 out.println(" /* . . . . . .*/");
464 out.println(" default:");
465 out.println(" throw new Exception(");
466 out.println(" \"Invalid action number found in " +
467 "internal parse table\");");
468 out.println();
469 out.println(" }");
470
471 /* end of method */
472 out.println(" }");
473
474 /* end of class */
475 out.println("}");
476 out.println();
477
478 action_code_time = System.currentTimeMillis() - start_time;
479 }
480
481 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
482
483 /** Emit the production table.
484 * @param out stream to produce output on.
485 */
486 protected static void emit_production_table(PrintWriter out)
487 {
488 production all_prods[];
489 production prod;
490
491 long start_time = System.currentTimeMillis();
492
493 /* collect up the productions in order */
494 all_prods = new production[production.number()];
495 for (Enumeration p = production.all(); p.hasMoreElements(); )
496 {
497 prod = (production)p.nextElement();
498 all_prods[prod.index()] = prod;
499 }
500
501 // make short[][]
502 short[][] prod_table = new short[production.number()][2];
503 for (int i = 0; i<production.number(); i++)
504 {
505 prod = all_prods[i];
506 // { lhs symbol , rhs size }
507 prod_table[i][0] = (short) prod.lhs().the_symbol().index();
508 prod_table[i][1] = (short) prod.rhs_length();
509 }
510 /* do the top of the table */
511 out.println();
512 out.println(" /** Production table. */");
513 out.println(" protected static final short _production_table[][] = ");
514 out.print (" unpackFromStrings(");
515 do_table_as_string(out, prod_table);
516 out.println(");");
517
518 /* do the public accessor method */
519 out.println();
520 out.println(" /** Access to production table. */");
521 out.println(" public short[][] production_table() " +
522 "{return _production_table;}");
523
524 production_table_time = System.currentTimeMillis() - start_time;
525 }
526
527 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
528
529 /** Emit the action table.
530 * @param out stream to produce output on.
531 * @param act_tab the internal representation of the action table.
532 * @param compact_reduces do we use the most frequent reduce as default?
533 */
534 protected static void do_action_table(
535 PrintWriter out,
536 parse_action_table act_tab,
537 boolean compact_reduces)
538 throws internal_error
539 {
540 parse_action_row row;
541 parse_action act;
542 int red;
543
544 long start_time = System.currentTimeMillis();
545
546 /* collect values for the action table */
547 short[][] action_table = new short[act_tab.num_states()][];
548 /* do each state (row) of the action table */
549 for (int i = 0; i < act_tab.num_states(); i++)
550 {
551 /* get the row */
552 row = act_tab.under_state[i];
553
554 /* determine the default for the row */
555 if (compact_reduces)
556 row.compute_default();
557 else
558 row.default_reduce = -1;
559
560 /* make temporary table for the row. */
561 short[] temp_table = new short[2*row.size()];
562 int nentries = 0;
563
564 /* do each column */
565 for (int j = 0; j < row.size(); j++)
566 {
567 /* extract the action from the table */
568 act = row.under_term[j];
569
570 /* skip error entries these are all defaulted out */
571 if (act.kind() != parse_action.ERROR)
572 {
573 /* first put in the symbol index, then the actual entry */
574
575 /* shifts get positive entries of state number + 1 */
576 if (act.kind() == parse_action.SHIFT)
577 {
578 /* make entry */
579 temp_table[nentries++] = (short) j;
580 temp_table[nentries++] = (short)
581 (((shift_action)act).shift_to().index() + 1);
582 }
583
584 /* reduce actions get negated entries of production# + 1 */
585 else if (act.kind() == parse_action.REDUCE)
586 {
587 /* if its the default entry let it get defaulted out */
588 red = ((reduce_action)act).reduce_with().index();
589 if (red != row.default_reduce) {
590 /* make entry */
591 temp_table[nentries++] = (short) j;
592 temp_table[nentries++] = (short) (-(red+1));
593 }
594 } else if (act.kind() == parse_action.NONASSOC)
595 {
596 /* do nothing, since we just want a syntax error */
597 }
598 /* shouldn't be anything else */
599 else
600 throw new internal_error("Unrecognized action code " +
601 act.kind() + " found in parse table");
602 }
603 }
604
605 /* now we know how big to make the row */
606 action_table[i] = new short[nentries + 2];
607 System.arraycopy(temp_table, 0, action_table[i], 0, nentries);
608
609 /* finish off the row with a default entry */
610 action_table[i][nentries++] = -1;
611 if (row.default_reduce != -1)
612 action_table[i][nentries++] = (short) (-(row.default_reduce+1));
613 else
614 action_table[i][nentries++] = 0;
615 }
616
617 /* finish off the init of the table */
618 out.println();
619 out.println(" /** Parse-action table. */");
620 out.println(" protected static final short[][] _action_table = ");
621 out.print (" unpackFromStrings(");
622 do_table_as_string(out, action_table);
623 out.println(");");
624
625 /* do the public accessor method */
626 out.println();
627 out.println(" /** Access to parse-action table. */");
628 out.println(" public short[][] action_table() {return _action_table;}");
629
630 action_table_time = System.currentTimeMillis() - start_time;
631 }
632
633 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
634
635 /** Emit the reduce-goto table.
636 * @param out stream to produce output on.
637 * @param red_tab the internal representation of the reduce-goto table.
638 */
639 protected static void do_reduce_table(
640 PrintWriter out,
641 parse_reduce_table red_tab)
642 {
643 lalr_state goto_st;
644 parse_action act;
645
646 long start_time = System.currentTimeMillis();
647
648 /* collect values for reduce-goto table */
649 short[][] reduce_goto_table = new short[red_tab.num_states()][];
650 /* do each row of the reduce-goto table */
651 for (int i=0; i<red_tab.num_states(); i++)
652 {
653 /* make temporary table for the row. */
654 short[] temp_table = new short[2*red_tab.under_state[i].size()];
655 int nentries = 0;
656 /* do each entry in the row */
657 for (int j=0; j<red_tab.under_state[i].size(); j++)
658 {
659 /* get the entry */
660 goto_st = red_tab.under_state[i].under_non_term[j];
661
662 /* if we have none, skip it */
663 if (goto_st != null)
664 {
665 /* make entries for the index and the value */
666 temp_table[nentries++] = (short) j;
667 temp_table[nentries++] = (short) goto_st.index();
668 }
669 }
670 /* now we know how big to make the row. */
671 reduce_goto_table[i] = new short[nentries+2];
672 System.arraycopy(temp_table, 0, reduce_goto_table[i], 0, nentries);
673
674 /* end row with default value */
675 reduce_goto_table[i][nentries++] = -1;
676 reduce_goto_table[i][nentries++] = -1;
677 }
678
679 /* emit the table. */
680 out.println();
681 out.println(" /** <code>reduce_goto</code> table. */");
682 out.println(" protected static final short[][] _reduce_table = ");
683 out.print (" unpackFromStrings(");
684 do_table_as_string(out, reduce_goto_table);
685 out.println(");");
686
687 /* do the public accessor method */
688 out.println();
689 out.println(" /** Access to <code>reduce_goto</code> table. */");
690 out.println(" public short[][] reduce_table() {return _reduce_table;}");
691 out.println();
692
693 goto_table_time = System.currentTimeMillis() - start_time;
694 }
695
696 // print a string array encoding the given short[][] array.
697 protected static void do_table_as_string(PrintWriter out, short[][] sa) {
698 out.println("new String[] {");
699 out.print(" \"");
700 int nchar=0, nbytes=0;
701 nbytes+=do_escaped(out, (char)(sa.length>>16));
702 nchar =do_newline(out, nchar, nbytes);
703 nbytes+=do_escaped(out, (char)(sa.length&0xFFFF));
704 nchar =do_newline(out, nchar, nbytes);
705 for (int i=0; i<sa.length; i++) {
706 nbytes+=do_escaped(out, (char)(sa[i].length>>16));
707 nchar =do_newline(out, nchar, nbytes);
708 nbytes+=do_escaped(out, (char)(sa[i].length&0xFFFF));
709 nchar =do_newline(out, nchar, nbytes);
710 for (int j=0; j<sa[i].length; j++) {
711 // contents of string are (value+2) to allow for common -1, 0 cases
712 // (UTF-8 encoding is most efficient for 0<c<0x80)
713 nbytes+=do_escaped(out, (char)(2+sa[i][j]));
714 nchar =do_newline(out, nchar, nbytes);
715 }
716 }
717 out.print("\" }");
718 }
719 // split string if it is very long; start new line occasionally for neatness
720 protected static int do_newline(PrintWriter out, int nchar, int nbytes) {
721 if (nbytes > 65500) { out.println("\", "); out.print(" \""); }
722 else if (nchar > 11) { out.println("\" +"); out.print(" \""); }
723 else return nchar+1;
724 return 0;
725 }
726 // output an escape sequence for the given character code.
727 protected static int do_escaped(PrintWriter out, char c) {
728 StringBuffer escape = new StringBuffer();
729 if (c <= 0xFF) {
730 escape.append(Integer.toOctalString(c));
731 while(escape.length() < 3) escape.insert(0, '0');
732 } else {
733 escape.append(Integer.toHexString(c));
734 while(escape.length() < 4) escape.insert(0, '0');
735 escape.insert(0, 'u');
736 }
737 escape.insert(0, '\\');
738 out.print(escape.toString());
739
740 // return number of bytes this takes up in UTF-8 encoding.
741 if (c == 0) return 2;
742 if (c >= 0x01 && c <= 0x7F) return 1;
743 if (c >= 0x80 && c <= 0x7FF) return 2;
744 return 3;
745 }
746
747 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
748
749 /** Emit the parser subclass with embedded tables.
750 * @param out stream to produce output on.
751 * @param action_table internal representation of the action table.
752 * @param reduce_table internal representation of the reduce-goto table.
753 * @param start_st start state of the parse machine.
754 * @param start_prod start production of the grammar.
755 * @param compact_reduces do we use most frequent reduce as default?
756 * @param suppress_scanner should scanner be suppressed for compatibility?
757 */
758 public static void parser(
759 PrintWriter out,
760 parse_action_table action_table,
761 parse_reduce_table reduce_table,
762 int start_st,
763 production start_prod,
764 boolean compact_reduces,
765 boolean suppress_scanner)
766 throws internal_error
767 {
768 long start_time = System.currentTimeMillis();
769
770 /* top of file */
771 out.println();
772 out.println("//----------------------------------------------------");
773 out.println("// The following code was generated by " +
774 version.title_str);
775 out.println("// " + new Date());
776 out.println("//----------------------------------------------------");
777 out.println();
778 emit_package(out);
779
780 /* user supplied imports */
781 for (int i = 0; i < import_list.size(); i++)
782 out.println("import " + import_list.elementAt(i) + ";");
783
784 /* class header */
785 out.println();
786 out.println("/** "+version.title_str+" generated parser.");
787 out.println(" * @version " + new Date());
788 out.println(" */");
789 out.println("public class " + parser_class_name +
790 " extends java_cup.runtime.lr_parser {");
791
792 /* constructors [CSA/davidm, 24-jul-99] */
793 out.println();
794 out.println(" /** Default constructor. */");
795 out.println(" public " + parser_class_name + "() {super();}");
796 if (!suppress_scanner) {
797 out.println();
798 out.println(" /** Constructor which sets the default scanner. */");
799 out.println(" public " + parser_class_name +
800 "(java_cup.runtime.Scanner s) {super(s);}");
801 }
802
803 /* emit the various tables */
804 emit_production_table(out);
805 do_action_table(out, action_table, compact_reduces);
806 do_reduce_table(out, reduce_table);
807
808 /* instance of the action encapsulation class */
809 out.println(" /** Instance of action encapsulation class. */");
810 out.println(" protected " + pre("actions") + " action_obj;");
811 out.println();
812
813 /* action object initializer */
814 out.println(" /** Action encapsulation object initializer. */");
815 out.println(" protected void init_actions()");
816 out.println(" {");
817 out.println(" action_obj = new " + pre("actions") + "(this);");
818 out.println(" }");
819 out.println();
820
821 /* access to action code */
822 out.println(" /** Invoke a user supplied parse action. */");
823 out.println(" public java_cup.runtime.Symbol do_action(");
824 out.println(" int act_num,");
825 out.println(" java_cup.runtime.lr_parser parser,");
826 out.println(" java.util.Stack stack,");
827 out.println(" int top)");
828 out.println(" throws java.lang.Exception");
829 out.println(" {");
830 out.println(" /* call code in generated class */");
831 out.println(" return action_obj." + pre("do_action(") +
832 "act_num, parser, stack, top);");
833 out.println(" }");
834 out.println("");
835
836
837 /* method to tell the parser about the start state */
838 out.println(" /** Indicates start state. */");
839 out.println(" public int start_state() {return " + start_st + ";}");
840
841 /* method to indicate start production */
842 out.println(" /** Indicates start production. */");
843 out.println(" public int start_production() {return " +
844 start_production.index() + ";}");
845 out.println();
846
847 /* methods to indicate EOF and error symbol indexes */
848 out.println(" /** <code>EOF</code> Symbol index. */");
849 out.println(" public int EOF_sym() {return " + terminal.EOF.index() +
850 ";}");
851 out.println();
852 out.println(" /** <code>error</code> Symbol index. */");
853 out.println(" public int error_sym() {return " + terminal.error.index() +
854 ";}");
855 out.println();
856
857 /* user supplied code for user_init() */
858 if (init_code != null)
859 {
860 out.println();
861 out.println(" /** User initialization code. */");
862 out.println(" public void user_init() throws java.lang.Exception");
863 out.println(" {");
864 out.println(init_code);
865 out.println(" }");
866 }
867
868 /* user supplied code for scan */
869 if (scan_code != null)
870 {
871 out.println();
872 out.println(" /** Scan to get the next Symbol. */");
873 out.println(" public java_cup.runtime.Symbol scan()");
874 out.println(" throws java.lang.Exception");
875 out.println(" {");
876 out.println(scan_code);
877 out.println(" }");
878 }
879
880 /* user supplied code */
881 if (parser_code != null)
882 {
883 out.println();
884 out.println(parser_code);
885 }
886
887 /* end of class */
888 out.println("}");
889
890 /* put out the action code class */
891 emit_action_code(out, start_prod);
892
893 parser_time = System.currentTimeMillis() - start_time;
894 }
895
896 /*-----------------------------------------------------------*/
897 }