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8a21415b ML |
1 | /* Copyright (c) 1982 Regents of the University of California */ |
2 | ||
3 | static char sccsid[] = "@(#)@(#)symbols.c 1.1 %G%"; | |
4 | ||
5 | /* | |
6 | * Symbol management. | |
7 | */ | |
8 | ||
9 | #include "defs.h" | |
10 | #include "symbols.h" | |
11 | #include "languages.h" | |
12 | #include "printsym.h" | |
13 | #include "tree.h" | |
14 | #include "operators.h" | |
15 | #include "eval.h" | |
16 | #include "mappings.h" | |
17 | #include "events.h" | |
18 | #include "process.h" | |
19 | #include "runtime.h" | |
20 | #include "machine.h" | |
21 | #include "names.h" | |
22 | ||
23 | #ifndef public | |
24 | typedef struct Symbol *Symbol; | |
25 | ||
26 | #include "machine.h" | |
27 | #include "names.h" | |
28 | #include "languages.h" | |
29 | ||
30 | /* | |
31 | * Symbol classes | |
32 | */ | |
33 | ||
34 | typedef enum { | |
35 | BADUSE, CONST, TYPE, VAR, ARRAY, PTRFILE, RECORD, FIELD, | |
36 | PROC, FUNC, FVAR, REF, PTR, FILET, SET, RANGE, | |
37 | LABEL, WITHPTR, SCAL, STR, PROG, IMPROPER, VARNT, | |
38 | FPROC, FFUNC, MODULE, TYPEREF, TAG | |
39 | } Symclass; | |
40 | ||
41 | struct Symbol { | |
42 | Name name; | |
43 | Language language; | |
44 | Symclass class : 8; | |
45 | Integer level : 8; | |
46 | Symbol type; | |
47 | Symbol chain; | |
48 | union { | |
49 | int offset; /* variable address */ | |
50 | long iconval; /* integer constant value */ | |
51 | double fconval; /* floating constant value */ | |
52 | struct { /* field offset and size (both in bits) */ | |
53 | int offset; | |
54 | int length; | |
55 | } field; | |
56 | struct { /* range bounds */ | |
57 | long lower; | |
58 | long upper; | |
59 | } rangev; | |
60 | struct { /* address of function value, code */ | |
61 | int offset; | |
62 | Address beginaddr; | |
63 | } funcv; | |
64 | struct { /* variant record info */ | |
65 | int size; | |
66 | Symbol vtorec; | |
67 | Symbol vtag; | |
68 | } varnt; | |
69 | } symvalue; | |
70 | Symbol block; /* symbol containing this symbol */ | |
71 | Symbol next_sym; /* hash chain */ | |
72 | }; | |
73 | ||
74 | /* | |
75 | * Basic types. | |
76 | */ | |
77 | ||
78 | Symbol t_boolean; | |
79 | Symbol t_char; | |
80 | Symbol t_int; | |
81 | Symbol t_real; | |
82 | Symbol t_nil; | |
83 | ||
84 | Symbol program; | |
85 | Symbol curfunc; | |
86 | ||
87 | #define symname(s) ident(s->name) | |
88 | #define codeloc(f) ((f)->symvalue.funcv.beginaddr) | |
89 | #define isblock(s) (Boolean) ( \ | |
90 | s->class == FUNC or s->class == PROC or \ | |
91 | s->class == MODULE or s->class == PROG \ | |
92 | ) | |
93 | ||
94 | #include "tree.h" | |
95 | ||
96 | /* | |
97 | * Some macros to make finding a symbol with certain attributes. | |
98 | */ | |
99 | ||
100 | #define find(s, withname) \ | |
101 | { \ | |
102 | s = lookup(withname); \ | |
103 | while (s != nil and not (s->name == (withname) and | |
104 | ||
105 | #define where /* qualification */ | |
106 | ||
107 | #define endfind(s) )) { \ | |
108 | s = s->next_sym; \ | |
109 | } \ | |
110 | } | |
111 | ||
112 | #endif | |
113 | ||
114 | /* | |
115 | * Symbol table structure currently does not support deletions. | |
116 | */ | |
117 | ||
118 | #define HASHTABLESIZE 2003 | |
119 | ||
120 | private Symbol hashtab[HASHTABLESIZE]; | |
121 | ||
122 | #define hash(name) ((((unsigned) name) >> 2) mod HASHTABLESIZE) | |
123 | ||
124 | /* | |
125 | * Allocate a new symbol. | |
126 | */ | |
127 | ||
128 | #define SYMBLOCKSIZE 1000 | |
129 | ||
130 | typedef struct Sympool { | |
131 | struct Symbol sym[SYMBLOCKSIZE]; | |
132 | struct Sympool *prevpool; | |
133 | } *Sympool; | |
134 | ||
135 | private Sympool sympool = nil; | |
136 | private Integer nleft = 0; | |
137 | private struct Sympool zeropool; | |
138 | ||
139 | public Symbol symbol_alloc() | |
140 | { | |
141 | register Sympool newpool; | |
142 | ||
143 | if (nleft <= 0) { | |
144 | newpool = new(Sympool); | |
145 | *newpool = zeropool; | |
146 | newpool->prevpool = sympool; | |
147 | sympool = newpool; | |
148 | nleft = SYMBLOCKSIZE; | |
149 | } | |
150 | --nleft; | |
151 | return &(sympool->sym[nleft]); | |
152 | } | |
153 | ||
154 | /* | |
155 | * Free all the symbols currently allocated. | |
156 | */ | |
157 | ||
158 | public symbol_free() | |
159 | { | |
160 | Sympool s, t; | |
161 | register Integer i; | |
162 | ||
163 | s = sympool; | |
164 | while (s != nil) { | |
165 | t = s->prevpool; | |
166 | dispose(s); | |
167 | s = t; | |
168 | } | |
169 | for (i = 0; i < HASHTABLESIZE; i++) { | |
170 | hashtab[i] = nil; | |
171 | } | |
172 | sympool = nil; | |
173 | nleft = 0; | |
174 | } | |
175 | ||
176 | /* | |
177 | * Create a new symbol with the given attributes. | |
178 | */ | |
179 | ||
180 | public Symbol newSymbol(name, blevel, class, type, chain) | |
181 | Name name; | |
182 | Integer blevel; | |
183 | Symclass class; | |
184 | Symbol type; | |
185 | Symbol chain; | |
186 | { | |
187 | register Symbol s; | |
188 | ||
189 | s = symbol_alloc(); | |
190 | s->name = name; | |
191 | s->level = blevel; | |
192 | s->class = class; | |
193 | s->type = type; | |
194 | s->chain = chain; | |
195 | return s; | |
196 | } | |
197 | ||
198 | /* | |
199 | * Insert a symbol into the hash table. | |
200 | */ | |
201 | ||
202 | public Symbol insert(name) | |
203 | Name name; | |
204 | { | |
205 | register Symbol s; | |
206 | register unsigned int h; | |
207 | ||
208 | h = hash(name); | |
209 | s = symbol_alloc(); | |
210 | s->name = name; | |
211 | s->next_sym = hashtab[h]; | |
212 | hashtab[h] = s; | |
213 | return s; | |
214 | } | |
215 | ||
216 | /* | |
217 | * Symbol lookup. | |
218 | */ | |
219 | ||
220 | public Symbol lookup(name) | |
221 | Name name; | |
222 | { | |
223 | register Symbol s; | |
224 | register unsigned int h; | |
225 | ||
226 | h = hash(name); | |
227 | s = hashtab[h]; | |
228 | while (s != nil and s->name != name) { | |
229 | s = s->next_sym; | |
230 | } | |
231 | return s; | |
232 | } | |
233 | ||
234 | /* | |
235 | * Dump out all the variables associated with the given | |
236 | * procedure, function, or program at the given recursive level. | |
237 | * | |
238 | * This is quite inefficient. We traverse the entire symbol table | |
239 | * each time we're called. The assumption is that this routine | |
240 | * won't be called frequently enough to merit improved performance. | |
241 | */ | |
242 | ||
243 | public dumpvars(f, frame) | |
244 | Symbol f; | |
245 | Frame frame; | |
246 | { | |
247 | register Integer i; | |
248 | register Symbol s; | |
249 | ||
250 | for (i = 0; i < HASHTABLESIZE; i++) { | |
251 | for (s = hashtab[i]; s != nil; s = s->next_sym) { | |
252 | if (container(s) == f) { | |
253 | if (should_print(s)) { | |
254 | printv(s, frame); | |
255 | putchar('\n'); | |
256 | } else if (s->class == MODULE) { | |
257 | dumpvars(s, frame); | |
258 | } | |
259 | } | |
260 | } | |
261 | } | |
262 | } | |
263 | ||
264 | /* | |
265 | * Create a builtin type. | |
266 | * Builtin types are circular in that btype->type->type = btype. | |
267 | */ | |
268 | ||
269 | public Symbol maketype(name, lower, upper) | |
270 | String name; | |
271 | long lower; | |
272 | long upper; | |
273 | { | |
274 | register Symbol s; | |
275 | ||
276 | s = newSymbol(identname(name, true), 0, TYPE, nil, nil); | |
277 | s->language = findlanguage(".c"); | |
278 | s->type = newSymbol(nil, 0, RANGE, s, nil); | |
279 | s->type->symvalue.rangev.lower = lower; | |
280 | s->type->symvalue.rangev.upper = upper; | |
281 | return s; | |
282 | } | |
283 | ||
284 | /* | |
285 | * These functions are now compiled inline. | |
286 | * | |
287 | * public String symname(s) | |
288 | Symbol s; | |
289 | { | |
290 | checkref(s); | |
291 | return ident(s->name); | |
292 | } | |
293 | ||
294 | * | |
295 | * public Address codeloc(f) | |
296 | Symbol f; | |
297 | { | |
298 | checkref(f); | |
299 | if (not isblock(f)) { | |
300 | panic("codeloc: \"%s\" is not a block", ident(f->name)); | |
301 | } | |
302 | return f->symvalue.funcv.beginaddr; | |
303 | } | |
304 | * | |
305 | */ | |
306 | ||
307 | /* | |
308 | * Reduce type to avoid worrying about type names. | |
309 | */ | |
310 | ||
311 | public Symbol rtype(type) | |
312 | Symbol type; | |
313 | { | |
314 | register Symbol t; | |
315 | ||
316 | t = type; | |
317 | if (t != nil) { | |
318 | if (t->class == VAR or t->class == FIELD) { | |
319 | t = t->type; | |
320 | } | |
321 | while (t->class == TYPE or t->class == TAG) { | |
322 | t = t->type; | |
323 | } | |
324 | } | |
325 | return t; | |
326 | } | |
327 | ||
328 | public Integer level(s) | |
329 | Symbol s; | |
330 | { | |
331 | checkref(s); | |
332 | return s->level; | |
333 | } | |
334 | ||
335 | public Symbol container(s) | |
336 | Symbol s; | |
337 | { | |
338 | checkref(s); | |
339 | return s->block; | |
340 | } | |
341 | ||
342 | /* | |
343 | * Return the object address of the given symbol. | |
344 | * | |
345 | * There are the following possibilities: | |
346 | * | |
347 | * globals - just take offset | |
348 | * locals - take offset from locals base | |
349 | * arguments - take offset from argument base | |
350 | * register - offset is register number | |
351 | */ | |
352 | ||
353 | #define isglobal(s) (s->level == 1 or s->level == 2) | |
354 | #define islocaloff(s) (s->level >= 3 and s->symvalue.offset < 0) | |
355 | #define isparamoff(s) (s->level >= 3 and s->symvalue.offset >= 0) | |
356 | #define isreg(s) (s->level < 0) | |
357 | ||
358 | public Address address(s, frame) | |
359 | Symbol s; | |
360 | Frame frame; | |
361 | { | |
362 | register Frame frp; | |
363 | register Address addr; | |
364 | register Symbol cur; | |
365 | ||
366 | checkref(s); | |
367 | if (not isactive(s->block)) { | |
368 | error("\"%s\" is not currently defined", symname(s)); | |
369 | } else if (isglobal(s)) { | |
370 | addr = s->symvalue.offset; | |
371 | } else { | |
372 | frp = frame; | |
373 | if (frp == nil) { | |
374 | cur = s->block; | |
375 | while (cur != nil and cur->class == MODULE) { | |
376 | cur = cur->block; | |
377 | } | |
378 | if (cur == nil) { | |
379 | cur = whatblock(pc); | |
380 | } | |
381 | frp = findframe(cur); | |
382 | if (frp == nil) { | |
383 | panic("unexpected nil frame for \"%s\"", symname(s)); | |
384 | } | |
385 | } | |
386 | if (islocaloff(s)) { | |
387 | addr = locals_base(frp) + s->symvalue.offset; | |
388 | } else if (isparamoff(s)) { | |
389 | addr = args_base(frp) + s->symvalue.offset; | |
390 | } else if (isreg(s)) { | |
391 | addr = savereg(s->symvalue.offset, frp); | |
392 | } else { | |
393 | panic("address: bad symbol \"%s\"", symname(s)); | |
394 | } | |
395 | } | |
396 | return addr; | |
397 | } | |
398 | ||
399 | /* | |
400 | * Define a symbol used to access register values. | |
401 | */ | |
402 | ||
403 | public defregname(n, r) | |
404 | Name n; | |
405 | Integer r; | |
406 | { | |
407 | register Symbol s, t; | |
408 | ||
409 | s = insert(n); | |
410 | t = newSymbol(nil, 0, PTR, t_int, nil); | |
411 | t->language = findlanguage(".s"); | |
412 | s->language = t->language; | |
413 | s->class = VAR; | |
414 | s->level = -3; | |
415 | s->type = t; | |
416 | s->block = program; | |
417 | s->symvalue.offset = r; | |
418 | } | |
419 | ||
420 | /* | |
421 | * Resolve an "abstract" type reference. | |
422 | * | |
423 | * It is possible in C to define a pointer to a type, but never define | |
424 | * the type in a particular source file. Here we try to resolve | |
425 | * the type definition. This is problematic, it is possible to | |
426 | * have multiple, different definitions for the same name type. | |
427 | */ | |
428 | ||
429 | public findtype(s) | |
430 | Symbol s; | |
431 | { | |
432 | register Symbol t, u, prev; | |
433 | ||
434 | u = s; | |
435 | prev = nil; | |
436 | while (u != nil and u->class != BADUSE) { | |
437 | if (u->name != nil) { | |
438 | prev = u; | |
439 | } | |
440 | u = u->type; | |
441 | } | |
442 | if (prev == nil) { | |
443 | error("couldn't find link to type reference"); | |
444 | } | |
445 | find(t, prev->name) where | |
446 | t->type != nil and t->class == prev->class and | |
447 | t->type->class != BADUSE and t->block->class == MODULE | |
448 | endfind(t); | |
449 | if (t == nil) { | |
450 | error("couldn't resolve reference"); | |
451 | } else { | |
452 | prev->type = t->type; | |
453 | } | |
454 | } | |
455 | ||
456 | /* | |
457 | * Find the size in bytes of the given type. | |
458 | * | |
459 | * This is probably the WRONG thing to do. The size should be kept | |
460 | * as an attribute in the symbol information as is done for structures | |
461 | * and fields. I haven't gotten around to cleaning this up yet. | |
462 | */ | |
463 | ||
464 | #define MINCHAR -128 | |
465 | #define MAXCHAR 127 | |
466 | #define MINSHORT -32768 | |
467 | #define MAXSHORT 32767 | |
468 | ||
469 | public Integer size(sym) | |
470 | Symbol sym; | |
471 | { | |
472 | register Symbol s, t; | |
473 | register int nel, elsize; | |
474 | long lower, upper; | |
475 | int r; | |
476 | ||
477 | t = sym; | |
478 | checkref(t); | |
479 | switch (t->class) { | |
480 | case RANGE: | |
481 | lower = t->symvalue.rangev.lower; | |
482 | upper = t->symvalue.rangev.upper; | |
483 | if (upper == 0 and lower > 0) { /* real */ | |
484 | r = lower; | |
485 | } else if (lower >= MINCHAR and upper <= MAXCHAR) { | |
486 | r = sizeof(char); | |
487 | } else if (lower >= MINSHORT and upper <= MAXSHORT) { | |
488 | r = sizeof(short); | |
489 | } else { | |
490 | r = sizeof(long); | |
491 | } | |
492 | break; | |
493 | ||
494 | case ARRAY: | |
495 | elsize = size(t->type); | |
496 | nel = 1; | |
497 | for (t = t->chain; t != nil; t = t->chain) { | |
498 | s = rtype(t); | |
499 | lower = s->symvalue.rangev.lower; | |
500 | upper = s->symvalue.rangev.upper; | |
501 | nel *= (upper-lower+1); | |
502 | } | |
503 | r = nel*elsize; | |
504 | break; | |
505 | ||
506 | case VAR: | |
507 | case FVAR: | |
508 | r = size(t->type); | |
509 | if (r < sizeof(Word)) { | |
510 | r = sizeof(Word); | |
511 | } | |
512 | break; | |
513 | ||
514 | case CONST: | |
515 | r = size(t->type); | |
516 | break; | |
517 | ||
518 | case TYPE: | |
519 | if (t->type->class == PTR and t->type->type->class == BADUSE) { | |
520 | findtype(t); | |
521 | } | |
522 | r = size(t->type); | |
523 | break; | |
524 | ||
525 | case TAG: | |
526 | r = size(t->type); | |
527 | break; | |
528 | ||
529 | case FIELD: | |
530 | r = (t->symvalue.field.length + 7) div 8; | |
531 | break; | |
532 | ||
533 | case RECORD: | |
534 | case VARNT: | |
535 | r = t->symvalue.offset; | |
536 | if (r == 0 and t->chain != nil) { | |
537 | panic("missing size information for record"); | |
538 | } | |
539 | break; | |
540 | ||
541 | case PTR: | |
542 | case REF: | |
543 | case FILET: | |
544 | r = sizeof(Word); | |
545 | break; | |
546 | ||
547 | case SCAL: | |
548 | if (t->symvalue.iconval > 255) { | |
549 | r = sizeof(short); | |
550 | } else { | |
551 | r = sizeof(char); | |
552 | } | |
553 | break; | |
554 | ||
555 | case FPROC: | |
556 | case FFUNC: | |
557 | r = sizeof(Word); | |
558 | break; | |
559 | ||
560 | case PROC: | |
561 | case FUNC: | |
562 | case MODULE: | |
563 | case PROG: | |
564 | r = sizeof(Symbol); | |
565 | break; | |
566 | ||
567 | default: | |
568 | if (ord(t->class) > ord(TYPEREF)) { | |
569 | panic("size: bad class (%d)", ord(t->class)); | |
570 | } else { | |
571 | error("improper operation on a %s", classname(t)); | |
572 | } | |
573 | /* NOTREACHED */ | |
574 | } | |
575 | if (r < sizeof(Word) and isparam(sym)) { | |
576 | r = sizeof(Word); | |
577 | } | |
578 | return r; | |
579 | } | |
580 | ||
581 | /* | |
582 | * Test if a symbol is a parameter. This is true if there | |
583 | * is a cycle from s->block to s via chain pointers. | |
584 | */ | |
585 | ||
586 | public Boolean isparam(s) | |
587 | Symbol s; | |
588 | { | |
589 | register Symbol t; | |
590 | ||
591 | t = s->block; | |
592 | while (t != nil and t != s) { | |
593 | t = t->chain; | |
594 | } | |
595 | return (Boolean) (t != nil); | |
596 | } | |
597 | ||
598 | /* | |
599 | * Test if a symbol is a var parameter, i.e. has class REF. | |
600 | */ | |
601 | ||
602 | public Boolean isvarparam(s) | |
603 | Symbol s; | |
604 | { | |
605 | return (Boolean) (s->class == REF); | |
606 | } | |
607 | ||
608 | /* | |
609 | * Test if a symbol is a variable (actually any addressible quantity | |
610 | * with do). | |
611 | */ | |
612 | ||
613 | public Boolean isvariable(s) | |
614 | register Symbol s; | |
615 | { | |
616 | return (Boolean) (s->class == VAR or s->class == FVAR or s->class == REF); | |
617 | } | |
618 | ||
619 | /* | |
620 | * Test if a symbol is a block, e.g. function, procedure, or the | |
621 | * main program. | |
622 | * | |
623 | * This function is now expanded inline for efficiency. | |
624 | * | |
625 | * public Boolean isblock(s) | |
626 | register Symbol s; | |
627 | { | |
628 | return (Boolean) ( | |
629 | s->class == FUNC or s->class == PROC or | |
630 | s->class == MODULE or s->class == PROG | |
631 | ); | |
632 | } | |
633 | * | |
634 | */ | |
635 | ||
636 | /* | |
637 | * Test if a symbol is a module. | |
638 | */ | |
639 | ||
640 | public Boolean ismodule(s) | |
641 | register Symbol s; | |
642 | { | |
643 | return (Boolean) (s->class == MODULE); | |
644 | } | |
645 | ||
646 | /* | |
647 | * Test if a symbol is builtin, that is, a predefined type or | |
648 | * reserved word. | |
649 | */ | |
650 | ||
651 | public Boolean isbuiltin(s) | |
652 | register Symbol s; | |
653 | { | |
654 | return (Boolean) (s->level == 0 and s->class != PROG and s->class != VAR); | |
655 | } | |
656 | ||
657 | /* | |
658 | * Test if two types match. | |
659 | * Equivalent names implies a match in any language. | |
660 | * | |
661 | * Special symbols must be handled with care. | |
662 | */ | |
663 | ||
664 | public Boolean compatible(t1, t2) | |
665 | register Symbol t1, t2; | |
666 | { | |
667 | Boolean b; | |
668 | ||
669 | if (t1 == t2) { | |
670 | b = true; | |
671 | } else if (t1 == nil or t2 == nil) { | |
672 | b = false; | |
673 | } else if (t1 == procsym) { | |
674 | b = isblock(t2); | |
675 | } else if (t2 == procsym) { | |
676 | b = isblock(t1); | |
677 | } else if (t1->language == nil) { | |
678 | b = (Boolean) (t2->language == nil or | |
679 | (*language_op(t2->language, L_TYPEMATCH))(t1, t2)); | |
680 | } else { | |
681 | b = (Boolean) (*language_op(t1->language, L_TYPEMATCH))(t1, t2); | |
682 | } | |
683 | return b; | |
684 | } | |
685 | ||
686 | /* | |
687 | * Check for a type of the given name. | |
688 | */ | |
689 | ||
690 | public Boolean istypename(type, name) | |
691 | Symbol type; | |
692 | String name; | |
693 | { | |
694 | Symbol t; | |
695 | Boolean b; | |
696 | ||
697 | t = type; | |
698 | checkref(t); | |
699 | b = (Boolean) ( | |
700 | t->class == TYPE and t->name == identname(name, true) | |
701 | ); | |
702 | return b; | |
703 | } | |
704 | ||
705 | /* | |
706 | * Test if the name of a symbol is uniquely defined or not. | |
707 | */ | |
708 | ||
709 | public Boolean isambiguous(s) | |
710 | register Symbol s; | |
711 | { | |
712 | register Symbol t; | |
713 | ||
714 | find(t, s->name) where t != s endfind(t); | |
715 | return (Boolean) (t != nil); | |
716 | } | |
717 | ||
718 | typedef char *Arglist; | |
719 | ||
720 | #define nextarg(type) ((type *) (ap += sizeof(type)))[-1] | |
721 | ||
722 | private Symbol mkstring(); | |
723 | private Symbol namenode(); | |
724 | ||
725 | /* | |
726 | * Determine the type of a parse tree. | |
727 | * Also make some symbol-dependent changes to the tree such as | |
728 | * changing removing RVAL nodes for constant symbols. | |
729 | */ | |
730 | ||
731 | public assigntypes(p) | |
732 | register Node p; | |
733 | { | |
734 | register Node p1; | |
735 | register Symbol s; | |
736 | ||
737 | switch (p->op) { | |
738 | case O_SYM: | |
739 | p->nodetype = namenode(p); | |
740 | break; | |
741 | ||
742 | case O_LCON: | |
743 | p->nodetype = t_int; | |
744 | break; | |
745 | ||
746 | case O_FCON: | |
747 | p->nodetype = t_real; | |
748 | break; | |
749 | ||
750 | case O_SCON: | |
751 | p->value.scon = strdup(p->value.scon); | |
752 | s = mkstring(p->value.scon); | |
753 | if (s == t_char) { | |
754 | p->op = O_LCON; | |
755 | p->value.lcon = p->value.scon[0]; | |
756 | } | |
757 | p->nodetype = s; | |
758 | break; | |
759 | ||
760 | case O_INDIR: | |
761 | p1 = p->value.arg[0]; | |
762 | chkclass(p1, PTR); | |
763 | p->nodetype = rtype(p1->nodetype)->type; | |
764 | break; | |
765 | ||
766 | case O_DOT: | |
767 | p->nodetype = p->value.arg[1]->value.sym; | |
768 | break; | |
769 | ||
770 | case O_RVAL: | |
771 | p1 = p->value.arg[0]; | |
772 | p->nodetype = p1->nodetype; | |
773 | if (p1->op == O_SYM) { | |
774 | if (p1->nodetype->class == FUNC) { | |
775 | p->op = O_CALL; | |
776 | p->value.arg[1] = nil; | |
777 | } else if (p1->value.sym->class == CONST) { | |
778 | if (compatible(p1->value.sym->type, t_real)) { | |
779 | p->op = O_FCON; | |
780 | p->value.fcon = p1->value.sym->symvalue.fconval; | |
781 | p->nodetype = t_real; | |
782 | dispose(p1); | |
783 | } else { | |
784 | p->op = O_LCON; | |
785 | p->value.lcon = p1->value.sym->symvalue.iconval; | |
786 | p->nodetype = p1->value.sym->type; | |
787 | dispose(p1); | |
788 | } | |
789 | } else if (isreg(p1->value.sym)) { | |
790 | p->op = O_SYM; | |
791 | p->value.sym = p1->value.sym; | |
792 | dispose(p1); | |
793 | } | |
794 | } else if (p1->op == O_INDIR and p1->value.arg[0]->op == O_SYM) { | |
795 | s = p1->value.arg[0]->value.sym; | |
796 | if (isreg(s)) { | |
797 | p1->op = O_SYM; | |
798 | dispose(p1->value.arg[0]); | |
799 | p1->value.sym = s; | |
800 | p1->nodetype = s; | |
801 | } | |
802 | } | |
803 | break; | |
804 | ||
805 | /* | |
806 | * Perform a cast if the call is of the form "type(expr)". | |
807 | */ | |
808 | case O_CALL: | |
809 | p1 = p->value.arg[0]; | |
810 | if (p1->op == O_SYM and | |
811 | (p1->value.sym->class == TYPE or p1->value.sym->class == TAG)) { | |
812 | s = p1->value.sym; | |
813 | dispose(p1); | |
814 | p1 = p->value.arg[1]; | |
815 | assert(p1->op == O_COMMA); | |
816 | if (p1->value.arg[1] != nil) { | |
817 | error("unexpected comma within type conversion"); | |
818 | } | |
819 | p->op = O_RVAL; | |
820 | p->value.arg[0] = p1->value.arg[0]; | |
821 | p->nodetype = s; | |
822 | p->value.arg[0]->nodetype = s; | |
823 | dispose(p1); | |
824 | } else { | |
825 | p->nodetype = rtype(p1->nodetype)->type; | |
826 | } | |
827 | break; | |
828 | ||
829 | case O_ITOF: | |
830 | p->nodetype = t_real; | |
831 | break; | |
832 | ||
833 | case O_NEG: | |
834 | s = p->value.arg[0]->nodetype; | |
835 | if (not compatible(s, t_int)) { | |
836 | if (not compatible(s, t_real)) { | |
837 | beginerrmsg(); | |
838 | prtree(stderr, p->value.arg[0]); | |
839 | fprintf(stderr, "is improper type"); | |
840 | enderrmsg(); | |
841 | } else { | |
842 | p->op = O_NEGF; | |
843 | } | |
844 | } | |
845 | p->nodetype = s; | |
846 | break; | |
847 | ||
848 | case O_ADD: | |
849 | case O_SUB: | |
850 | case O_MUL: | |
851 | case O_LT: | |
852 | case O_LE: | |
853 | case O_GT: | |
854 | case O_GE: | |
855 | case O_EQ: | |
856 | case O_NE: | |
857 | { | |
858 | Boolean t1real, t2real; | |
859 | Symbol t1, t2; | |
860 | ||
861 | t1 = rtype(p->value.arg[0]->nodetype); | |
862 | t2 = rtype(p->value.arg[1]->nodetype); | |
863 | t1real = compatible(t1, t_real); | |
864 | t2real = compatible(t2, t_real); | |
865 | if (t1real or t2real) { | |
866 | p->op = (Operator) (ord(p->op) + 1); | |
867 | if (not t1real) { | |
868 | p->value.arg[0] = build(O_ITOF, p->value.arg[0]); | |
869 | } else if (not t2real) { | |
870 | p->value.arg[1] = build(O_ITOF, p->value.arg[1]); | |
871 | } | |
872 | } else { | |
873 | if (t1real) { | |
874 | convert(&(p->value.arg[0]), t_int, O_NOP); | |
875 | } | |
876 | if (t2real) { | |
877 | convert(&(p->value.arg[1]), t_int, O_NOP); | |
878 | } | |
879 | } | |
880 | if (ord(p->op) >= ord(O_LT)) { | |
881 | p->nodetype = t_boolean; | |
882 | } else { | |
883 | if (t1real or t2real) { | |
884 | p->nodetype = t_real; | |
885 | } else { | |
886 | p->nodetype = t_int; | |
887 | } | |
888 | } | |
889 | break; | |
890 | } | |
891 | ||
892 | case O_DIVF: | |
893 | convert(&(p->value.arg[0]), t_real, O_ITOF); | |
894 | convert(&(p->value.arg[1]), t_real, O_ITOF); | |
895 | p->nodetype = t_real; | |
896 | break; | |
897 | ||
898 | case O_DIV: | |
899 | case O_MOD: | |
900 | convert(&(p->value.arg[0]), t_int, O_NOP); | |
901 | convert(&(p->value.arg[1]), t_int, O_NOP); | |
902 | p->nodetype = t_int; | |
903 | break; | |
904 | ||
905 | case O_AND: | |
906 | case O_OR: | |
907 | chkboolean(p->value.arg[0]); | |
908 | chkboolean(p->value.arg[1]); | |
909 | p->nodetype = t_boolean; | |
910 | break; | |
911 | ||
912 | case O_QLINE: | |
913 | p->nodetype = t_int; | |
914 | break; | |
915 | ||
916 | default: | |
917 | p->nodetype = nil; | |
918 | break; | |
919 | } | |
920 | } | |
921 | ||
922 | /* | |
923 | * Create a node for a name. The symbol for the name has already | |
924 | * been chosen, either implicitly with "which" or explicitly from | |
925 | * the dot routine. | |
926 | */ | |
927 | ||
928 | private Symbol namenode(p) | |
929 | Node p; | |
930 | { | |
931 | register Symbol r, s; | |
932 | register Node np; | |
933 | ||
934 | s = p->value.sym; | |
935 | if (s->class == REF) { | |
936 | np = new(Node); | |
937 | np->op = p->op; | |
938 | np->nodetype = s; | |
939 | np->value.sym = s; | |
940 | p->op = O_INDIR; | |
941 | p->value.arg[0] = np; | |
942 | } | |
943 | /* | |
944 | * Old way | |
945 | * | |
946 | if (s->class == CONST or s->class == VAR or s->class == FVAR) { | |
947 | r = s->type; | |
948 | } else { | |
949 | r = s; | |
950 | } | |
951 | * | |
952 | */ | |
953 | return s; | |
954 | } | |
955 | ||
956 | /* | |
957 | * Convert a tree to a type via a conversion operator; | |
958 | * if this isn't possible generate an error. | |
959 | * | |
960 | * Note the tree is call by address, hence the #define below. | |
961 | */ | |
962 | ||
963 | private convert(tp, typeto, op) | |
964 | Node *tp; | |
965 | Symbol typeto; | |
966 | Operator op; | |
967 | { | |
968 | #define tree (*tp) | |
969 | ||
970 | Symbol s; | |
971 | ||
972 | s = rtype(tree->nodetype); | |
973 | typeto = rtype(typeto); | |
974 | if (compatible(typeto, t_real) and compatible(s, t_int)) { | |
975 | tree = build(op, tree); | |
976 | } else if (not compatible(s, typeto)) { | |
977 | beginerrmsg(); | |
978 | prtree(stderr, s); | |
979 | fprintf(stderr, " is improper type"); | |
980 | enderrmsg(); | |
981 | } else if (op != O_NOP and s != typeto) { | |
982 | tree = build(op, tree); | |
983 | } | |
984 | ||
985 | #undef tree | |
986 | } | |
987 | ||
988 | /* | |
989 | * Construct a node for the dot operator. | |
990 | * | |
991 | * If the left operand is not a record, but rather a procedure | |
992 | * or function, then we interpret the "." as referencing an | |
993 | * "invisible" variable; i.e. a variable within a dynamically | |
994 | * active block but not within the static scope of the current procedure. | |
995 | */ | |
996 | ||
997 | public Node dot(record, fieldname) | |
998 | Node record; | |
999 | Name fieldname; | |
1000 | { | |
1001 | register Node p; | |
1002 | register Symbol s, t; | |
1003 | ||
1004 | if (isblock(record->nodetype)) { | |
1005 | find(s, fieldname) where | |
1006 | s->block == record->nodetype and | |
1007 | s->class != FIELD and s->class != TAG | |
1008 | endfind(s); | |
1009 | if (s == nil) { | |
1010 | beginerrmsg(); | |
1011 | fprintf(stderr, "\"%s\" is not defined in ", ident(fieldname)); | |
1012 | printname(stderr, record->nodetype); | |
1013 | enderrmsg(); | |
1014 | } | |
1015 | p = new(Node); | |
1016 | p->op = O_SYM; | |
1017 | p->value.sym = s; | |
1018 | p->nodetype = namenode(p); | |
1019 | } else { | |
1020 | p = record; | |
1021 | t = rtype(p->nodetype); | |
1022 | if (t->class == PTR) { | |
1023 | s = findfield(fieldname, t->type); | |
1024 | } else { | |
1025 | s = findfield(fieldname, t); | |
1026 | } | |
1027 | if (s == nil) { | |
1028 | beginerrmsg(); | |
1029 | fprintf(stderr, "\"%s\" is not a field in ", ident(fieldname)); | |
1030 | prtree(stderr, record); | |
1031 | enderrmsg(); | |
1032 | } | |
1033 | if (t->class == PTR and not isreg(record->nodetype)) { | |
1034 | p = build(O_INDIR, record); | |
1035 | } | |
1036 | p = build(O_DOT, p, build(O_SYM, s)); | |
1037 | } | |
1038 | return p; | |
1039 | } | |
1040 | ||
1041 | /* | |
1042 | * Return a tree corresponding to an array reference and do the | |
1043 | * error checking. | |
1044 | */ | |
1045 | ||
1046 | public Node subscript(a, slist) | |
1047 | Node a, slist; | |
1048 | { | |
1049 | register Symbol t; | |
1050 | register Node p; | |
1051 | Symbol etype, atype, eltype; | |
1052 | Node esub, olda; | |
1053 | ||
1054 | olda = a; | |
1055 | t = rtype(a->nodetype); | |
1056 | if (t->class != ARRAY) { | |
1057 | beginerrmsg(); | |
1058 | prtree(stderr, a); | |
1059 | fprintf(stderr, " is not an array"); | |
1060 | enderrmsg(); | |
1061 | } | |
1062 | eltype = t->type; | |
1063 | p = slist; | |
1064 | t = t->chain; | |
1065 | for (; p != nil and t != nil; p = p->value.arg[1], t = t->chain) { | |
1066 | esub = p->value.arg[0]; | |
1067 | etype = rtype(esub->nodetype); | |
1068 | atype = rtype(t); | |
1069 | if (not compatible(atype, etype)) { | |
1070 | beginerrmsg(); | |
1071 | fprintf(stderr, "subscript "); | |
1072 | prtree(stderr, esub); | |
1073 | fprintf(stderr, " is the wrong type"); | |
1074 | enderrmsg(); | |
1075 | } | |
1076 | a = build(O_INDEX, a, esub); | |
1077 | a->nodetype = eltype; | |
1078 | } | |
1079 | if (p != nil or t != nil) { | |
1080 | beginerrmsg(); | |
1081 | if (p != nil) { | |
1082 | fprintf(stderr, "too many subscripts for "); | |
1083 | } else { | |
1084 | fprintf(stderr, "not enough subscripts for "); | |
1085 | } | |
1086 | prtree(stderr, olda); | |
1087 | enderrmsg(); | |
1088 | } | |
1089 | return a; | |
1090 | } | |
1091 | ||
1092 | /* | |
1093 | * Evaluate a subscript index. | |
1094 | */ | |
1095 | ||
1096 | public int evalindex(s, i) | |
1097 | Symbol s; | |
1098 | long i; | |
1099 | { | |
1100 | long lb, ub; | |
1101 | ||
1102 | s = rtype(s)->chain; | |
1103 | lb = s->symvalue.rangev.lower; | |
1104 | ub = s->symvalue.rangev.upper; | |
1105 | if (i < lb or i > ub) { | |
1106 | error("subscript out of range"); | |
1107 | } | |
1108 | return (i - lb); | |
1109 | } | |
1110 | ||
1111 | /* | |
1112 | * Check to see if a tree is boolean-valued, if not it's an error. | |
1113 | */ | |
1114 | ||
1115 | public chkboolean(p) | |
1116 | register Node p; | |
1117 | { | |
1118 | if (p->nodetype != t_boolean) { | |
1119 | beginerrmsg(); | |
1120 | fprintf(stderr, "found "); | |
1121 | prtree(stderr, p); | |
1122 | fprintf(stderr, ", expected boolean expression"); | |
1123 | enderrmsg(); | |
1124 | } | |
1125 | } | |
1126 | ||
1127 | /* | |
1128 | * Check to make sure the given tree has a type of the given class. | |
1129 | */ | |
1130 | ||
1131 | private chkclass(p, class) | |
1132 | Node p; | |
1133 | Symclass class; | |
1134 | { | |
1135 | struct Symbol tmpsym; | |
1136 | ||
1137 | tmpsym.class = class; | |
1138 | if (rtype(p->nodetype)->class != class) { | |
1139 | beginerrmsg(); | |
1140 | fprintf(stderr, "\""); | |
1141 | prtree(stderr, p); | |
1142 | fprintf(stderr, "\" is not a %s", classname(&tmpsym)); | |
1143 | enderrmsg(); | |
1144 | } | |
1145 | } | |
1146 | ||
1147 | /* | |
1148 | * Construct a node for the type of a string. While we're at it, | |
1149 | * scan the string for '' that collapse to ', and chop off the ends. | |
1150 | */ | |
1151 | ||
1152 | private Symbol mkstring(str) | |
1153 | String str; | |
1154 | { | |
1155 | register char *p, *q; | |
1156 | register Symbol s; | |
1157 | ||
1158 | p = str; | |
1159 | q = str; | |
1160 | while (*p != '\0') { | |
1161 | if (*p == '\\') { | |
1162 | ++p; | |
1163 | } | |
1164 | *q = *p; | |
1165 | ++p; | |
1166 | ++q; | |
1167 | } | |
1168 | *q = '\0'; | |
1169 | s = newSymbol(nil, 0, ARRAY, t_char, nil); | |
1170 | s->language = findlanguage(".s"); | |
1171 | s->chain = newSymbol(nil, 0, RANGE, t_int, nil); | |
1172 | s->chain->language = s->language; | |
1173 | s->chain->symvalue.rangev.lower = 1; | |
1174 | s->chain->symvalue.rangev.upper = p - str + 1; | |
1175 | return s; | |
1176 | } | |
1177 | ||
1178 | /* | |
1179 | * Free up the space allocated for a string type. | |
1180 | */ | |
1181 | ||
1182 | public unmkstring(s) | |
1183 | Symbol s; | |
1184 | { | |
1185 | dispose(s->chain); | |
1186 | } | |
1187 | ||
1188 | /* | |
1189 | * Figure out the "current" variable or function being referred to, | |
1190 | * this is either the active one or the most visible from the | |
1191 | * current scope. | |
1192 | */ | |
1193 | ||
1194 | public Symbol which(n) | |
1195 | Name n; | |
1196 | { | |
1197 | register Symbol s, p, t, f; | |
1198 | ||
1199 | find(s, n) where s->class != FIELD and s->class != TAG endfind(s); | |
1200 | if (s == nil) { | |
1201 | s = lookup(n); | |
1202 | } | |
1203 | if (s == nil) { | |
1204 | error("\"%s\" is not defined", ident(n)); | |
1205 | } else if (s == program or isbuiltin(s)) { | |
1206 | t = s; | |
1207 | } else { | |
1208 | /* | |
1209 | * Old way | |
1210 | * | |
1211 | if (not isactive(program)) { | |
1212 | f = program; | |
1213 | } else { | |
1214 | f = whatblock(pc); | |
1215 | if (f == nil) { | |
1216 | panic("no block for addr 0x%x", pc); | |
1217 | } | |
1218 | } | |
1219 | * | |
1220 | * Now start with curfunc. | |
1221 | */ | |
1222 | p = curfunc; | |
1223 | do { | |
1224 | find(t, n) where | |
1225 | t->block == p and t->class != FIELD and t->class != TAG | |
1226 | endfind(t); | |
1227 | p = p->block; | |
1228 | } while (t == nil and p != nil); | |
1229 | if (t == nil) { | |
1230 | t = s; | |
1231 | } | |
1232 | } | |
1233 | return t; | |
1234 | } | |
1235 | ||
1236 | /* | |
1237 | * Find the symbol which is has the same name and scope as the | |
1238 | * given symbol but is of the given field. Return nil if there is none. | |
1239 | */ | |
1240 | ||
1241 | public Symbol findfield(fieldname, record) | |
1242 | Name fieldname; | |
1243 | Symbol record; | |
1244 | { | |
1245 | register Symbol t; | |
1246 | ||
1247 | t = rtype(record)->chain; | |
1248 | while (t != nil and t->name != fieldname) { | |
1249 | t = t->chain; | |
1250 | } | |
1251 | return t; | |
1252 | } |