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3d6b6a90 JG |
1 | /* Parse expressions for GDB. |
2 | Copyright (C) 1986, 1989, 1990, 1991 Free Software Foundation, Inc. | |
3 | Modified from expread.y by the Department of Computer Science at the | |
4 | State University of New York at Buffalo, 1991. | |
5 | ||
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
21 | ||
22 | /* Parse an expression from text in a string, | |
23 | and return the result as a struct expression pointer. | |
24 | That structure contains arithmetic operations in reverse polish, | |
25 | with constants represented by operations that are followed by special data. | |
26 | See expression.h for the details of the format. | |
27 | What is important here is that it can be built up sequentially | |
28 | during the process of parsing; the lower levels of the tree always | |
29 | come first in the result. */ | |
30 | ||
3d6b6a90 | 31 | #include "defs.h" |
3d6b6a90 | 32 | #include "symtab.h" |
1ab3bf1b | 33 | #include "gdbtypes.h" |
3d6b6a90 JG |
34 | #include "frame.h" |
35 | #include "expression.h" | |
36 | #include "value.h" | |
37 | #include "command.h" | |
38 | #include "language.h" | |
39 | #include "parser-defs.h" | |
40 | ||
1ab3bf1b JG |
41 | static void |
42 | prefixify_expression PARAMS ((struct expression *)); | |
43 | ||
44 | static int | |
45 | length_of_subexp PARAMS ((struct expression *, int)); | |
46 | ||
47 | static void | |
48 | prefixify_subexp PARAMS ((struct expression *, struct expression *, int, int)); | |
49 | ||
3d6b6a90 JG |
50 | /* Assign machine-independent names to certain registers |
51 | (unless overridden by the REGISTER_NAMES table) */ | |
52 | ||
a332e593 SC |
53 | #ifdef NO_STD_REGS |
54 | unsigned num_std_regs = 0; | |
55 | struct std_regs std_regs[1]; | |
56 | #else | |
3d6b6a90 | 57 | struct std_regs std_regs[] = { |
a332e593 | 58 | |
3d6b6a90 JG |
59 | #ifdef PC_REGNUM |
60 | { "pc", PC_REGNUM }, | |
61 | #endif | |
62 | #ifdef FP_REGNUM | |
63 | { "fp", FP_REGNUM }, | |
64 | #endif | |
65 | #ifdef SP_REGNUM | |
66 | { "sp", SP_REGNUM }, | |
67 | #endif | |
68 | #ifdef PS_REGNUM | |
69 | { "ps", PS_REGNUM }, | |
70 | #endif | |
a332e593 | 71 | |
3d6b6a90 JG |
72 | }; |
73 | ||
74 | unsigned num_std_regs = (sizeof std_regs / sizeof std_regs[0]); | |
75 | ||
a332e593 SC |
76 | #endif |
77 | ||
3d6b6a90 JG |
78 | |
79 | /* Begin counting arguments for a function call, | |
80 | saving the data about any containing call. */ | |
81 | ||
82 | void | |
83 | start_arglist () | |
84 | { | |
85 | register struct funcall *new = (struct funcall *) xmalloc (sizeof (struct funcall)); | |
86 | ||
87 | new->next = funcall_chain; | |
88 | new->arglist_len = arglist_len; | |
89 | arglist_len = 0; | |
90 | funcall_chain = new; | |
91 | } | |
92 | ||
93 | /* Return the number of arguments in a function call just terminated, | |
94 | and restore the data for the containing function call. */ | |
95 | ||
96 | int | |
97 | end_arglist () | |
98 | { | |
99 | register int val = arglist_len; | |
100 | register struct funcall *call = funcall_chain; | |
101 | funcall_chain = call->next; | |
102 | arglist_len = call->arglist_len; | |
be772100 | 103 | free ((PTR)call); |
3d6b6a90 JG |
104 | return val; |
105 | } | |
106 | ||
107 | /* Free everything in the funcall chain. | |
108 | Used when there is an error inside parsing. */ | |
109 | ||
110 | void | |
111 | free_funcalls () | |
112 | { | |
113 | register struct funcall *call, *next; | |
114 | ||
115 | for (call = funcall_chain; call; call = next) | |
116 | { | |
117 | next = call->next; | |
be772100 | 118 | free ((PTR)call); |
3d6b6a90 JG |
119 | } |
120 | } | |
121 | \f | |
122 | /* This page contains the functions for adding data to the struct expression | |
123 | being constructed. */ | |
124 | ||
125 | /* Add one element to the end of the expression. */ | |
126 | ||
127 | /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into | |
128 | a register through here */ | |
129 | ||
130 | void | |
131 | write_exp_elt (expelt) | |
132 | union exp_element expelt; | |
133 | { | |
134 | if (expout_ptr >= expout_size) | |
135 | { | |
136 | expout_size *= 2; | |
81028ab0 FF |
137 | expout = (struct expression *) |
138 | xrealloc ((char *) expout, sizeof (struct expression) | |
139 | + EXP_ELEM_TO_BYTES (expout_size)); | |
3d6b6a90 JG |
140 | } |
141 | expout->elts[expout_ptr++] = expelt; | |
142 | } | |
143 | ||
144 | void | |
145 | write_exp_elt_opcode (expelt) | |
146 | enum exp_opcode expelt; | |
147 | { | |
148 | union exp_element tmp; | |
149 | ||
150 | tmp.opcode = expelt; | |
151 | ||
152 | write_exp_elt (tmp); | |
153 | } | |
154 | ||
155 | void | |
156 | write_exp_elt_sym (expelt) | |
157 | struct symbol *expelt; | |
158 | { | |
159 | union exp_element tmp; | |
160 | ||
161 | tmp.symbol = expelt; | |
162 | ||
163 | write_exp_elt (tmp); | |
164 | } | |
165 | ||
166 | void | |
167 | write_exp_elt_longcst (expelt) | |
168 | LONGEST expelt; | |
169 | { | |
170 | union exp_element tmp; | |
171 | ||
172 | tmp.longconst = expelt; | |
173 | ||
174 | write_exp_elt (tmp); | |
175 | } | |
176 | ||
177 | void | |
178 | write_exp_elt_dblcst (expelt) | |
179 | double expelt; | |
180 | { | |
181 | union exp_element tmp; | |
182 | ||
183 | tmp.doubleconst = expelt; | |
184 | ||
185 | write_exp_elt (tmp); | |
186 | } | |
187 | ||
188 | void | |
189 | write_exp_elt_type (expelt) | |
190 | struct type *expelt; | |
191 | { | |
192 | union exp_element tmp; | |
193 | ||
194 | tmp.type = expelt; | |
195 | ||
196 | write_exp_elt (tmp); | |
197 | } | |
198 | ||
199 | void | |
200 | write_exp_elt_intern (expelt) | |
201 | struct internalvar *expelt; | |
202 | { | |
203 | union exp_element tmp; | |
204 | ||
205 | tmp.internalvar = expelt; | |
206 | ||
207 | write_exp_elt (tmp); | |
208 | } | |
209 | ||
210 | /* Add a string constant to the end of the expression. | |
d1065385 FF |
211 | |
212 | String constants are stored by first writing an expression element | |
213 | that contains the length of the string, then stuffing the string | |
214 | constant itself into however many expression elements are needed | |
215 | to hold it, and then writing another expression element that contains | |
216 | the length of the string. I.E. an expression element at each end of | |
217 | the string records the string length, so you can skip over the | |
218 | expression elements containing the actual string bytes from either | |
219 | end of the string. Note that this also allows gdb to handle | |
220 | strings with embedded null bytes, as is required for some languages. | |
221 | ||
222 | Don't be fooled by the fact that the string is null byte terminated, | |
223 | this is strictly for the convenience of debugging gdb itself. Gdb | |
224 | Gdb does not depend up the string being null terminated, since the | |
225 | actual length is recorded in expression elements at each end of the | |
226 | string. The null byte is taken into consideration when computing how | |
227 | many expression elements are required to hold the string constant, of | |
228 | course. */ | |
229 | ||
3d6b6a90 JG |
230 | |
231 | void | |
232 | write_exp_string (str) | |
233 | struct stoken str; | |
234 | { | |
235 | register int len = str.length; | |
d1065385 FF |
236 | register int lenelt; |
237 | register char *strdata; | |
3d6b6a90 | 238 | |
d1065385 FF |
239 | /* Compute the number of expression elements required to hold the string |
240 | (including a null byte terminator), along with one expression element | |
241 | at each end to record the actual string length (not including the | |
242 | null byte terminator). */ | |
3d6b6a90 | 243 | |
81028ab0 | 244 | lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1); |
d1065385 FF |
245 | |
246 | /* Ensure that we have enough available expression elements to store | |
247 | everything. */ | |
248 | ||
249 | if ((expout_ptr + lenelt) >= expout_size) | |
3d6b6a90 | 250 | { |
d1065385 | 251 | expout_size = max (expout_size * 2, expout_ptr + lenelt + 10); |
3d6b6a90 | 252 | expout = (struct expression *) |
1ab3bf1b | 253 | xrealloc ((char *) expout, (sizeof (struct expression) |
81028ab0 | 254 | + EXP_ELEM_TO_BYTES (expout_size))); |
3d6b6a90 | 255 | } |
d1065385 FF |
256 | |
257 | /* Write the leading length expression element (which advances the current | |
258 | expression element index), then write the string constant followed by a | |
259 | terminating null byte, and then write the trailing length expression | |
260 | element. */ | |
261 | ||
262 | write_exp_elt_longcst ((LONGEST) len); | |
263 | strdata = (char *) &expout->elts[expout_ptr]; | |
264 | memcpy (strdata, str.ptr, len); | |
265 | *(strdata + len) = '\0'; | |
266 | expout_ptr += lenelt - 2; | |
3d6b6a90 JG |
267 | write_exp_elt_longcst ((LONGEST) len); |
268 | } | |
81028ab0 FF |
269 | |
270 | /* Add a bitstring constant to the end of the expression. | |
271 | ||
272 | Bitstring constants are stored by first writing an expression element | |
273 | that contains the length of the bitstring (in bits), then stuffing the | |
274 | bitstring constant itself into however many expression elements are | |
275 | needed to hold it, and then writing another expression element that | |
276 | contains the length of the bitstring. I.E. an expression element at | |
277 | each end of the bitstring records the bitstring length, so you can skip | |
278 | over the expression elements containing the actual bitstring bytes from | |
279 | either end of the bitstring. */ | |
280 | ||
281 | void | |
282 | write_exp_bitstring (str) | |
283 | struct stoken str; | |
284 | { | |
285 | register int bits = str.length; /* length in bits */ | |
286 | register int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT; | |
287 | register int lenelt; | |
288 | register char *strdata; | |
289 | ||
290 | /* Compute the number of expression elements required to hold the bitstring, | |
291 | along with one expression element at each end to record the actual | |
292 | bitstring length in bits. */ | |
293 | ||
294 | lenelt = 2 + BYTES_TO_EXP_ELEM (len); | |
295 | ||
296 | /* Ensure that we have enough available expression elements to store | |
297 | everything. */ | |
298 | ||
299 | if ((expout_ptr + lenelt) >= expout_size) | |
300 | { | |
301 | expout_size = max (expout_size * 2, expout_ptr + lenelt + 10); | |
302 | expout = (struct expression *) | |
303 | xrealloc ((char *) expout, (sizeof (struct expression) | |
304 | + EXP_ELEM_TO_BYTES (expout_size))); | |
305 | } | |
306 | ||
307 | /* Write the leading length expression element (which advances the current | |
308 | expression element index), then write the bitstring constant, and then | |
309 | write the trailing length expression element. */ | |
310 | ||
311 | write_exp_elt_longcst ((LONGEST) bits); | |
312 | strdata = (char *) &expout->elts[expout_ptr]; | |
313 | memcpy (strdata, str.ptr, len); | |
314 | expout_ptr += lenelt - 2; | |
315 | write_exp_elt_longcst ((LONGEST) bits); | |
316 | } | |
3d6b6a90 JG |
317 | \f |
318 | /* Return a null-terminated temporary copy of the name | |
319 | of a string token. */ | |
320 | ||
321 | char * | |
322 | copy_name (token) | |
323 | struct stoken token; | |
324 | { | |
4ed3a9ea | 325 | memcpy (namecopy, token.ptr, token.length); |
3d6b6a90 JG |
326 | namecopy[token.length] = 0; |
327 | return namecopy; | |
328 | } | |
329 | \f | |
330 | /* Reverse an expression from suffix form (in which it is constructed) | |
331 | to prefix form (in which we can conveniently print or execute it). */ | |
332 | ||
1ab3bf1b | 333 | static void |
3d6b6a90 JG |
334 | prefixify_expression (expr) |
335 | register struct expression *expr; | |
336 | { | |
81028ab0 FF |
337 | register int len = |
338 | sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts); | |
3d6b6a90 JG |
339 | register struct expression *temp; |
340 | register int inpos = expr->nelts, outpos = 0; | |
341 | ||
342 | temp = (struct expression *) alloca (len); | |
343 | ||
344 | /* Copy the original expression into temp. */ | |
4ed3a9ea | 345 | memcpy (temp, expr, len); |
3d6b6a90 JG |
346 | |
347 | prefixify_subexp (temp, expr, inpos, outpos); | |
348 | } | |
349 | ||
350 | /* Return the number of exp_elements in the subexpression of EXPR | |
351 | whose last exp_element is at index ENDPOS - 1 in EXPR. */ | |
352 | ||
1ab3bf1b | 353 | static int |
3d6b6a90 JG |
354 | length_of_subexp (expr, endpos) |
355 | register struct expression *expr; | |
356 | register int endpos; | |
357 | { | |
358 | register int oplen = 1; | |
359 | register int args = 0; | |
360 | register int i; | |
361 | ||
d1065385 | 362 | if (endpos < 1) |
3d6b6a90 JG |
363 | error ("?error in length_of_subexp"); |
364 | ||
365 | i = (int) expr->elts[endpos - 1].opcode; | |
366 | ||
367 | switch (i) | |
368 | { | |
369 | /* C++ */ | |
370 | case OP_SCOPE: | |
81028ab0 FF |
371 | oplen = longest_to_int (expr->elts[endpos - 2].longconst); |
372 | oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1); | |
3d6b6a90 JG |
373 | break; |
374 | ||
375 | case OP_LONG: | |
376 | case OP_DOUBLE: | |
377 | oplen = 4; | |
378 | break; | |
379 | ||
380 | case OP_TYPE: | |
381 | case OP_BOOL: | |
382 | case OP_VAR_VALUE: | |
383 | case OP_LAST: | |
384 | case OP_REGISTER: | |
385 | case OP_INTERNALVAR: | |
386 | oplen = 3; | |
387 | break; | |
388 | ||
389 | case OP_FUNCALL: | |
390 | oplen = 3; | |
d1065385 | 391 | args = 1 + longest_to_int (expr->elts[endpos - 2].longconst); |
3d6b6a90 JG |
392 | break; |
393 | ||
394 | case UNOP_MAX: | |
395 | case UNOP_MIN: | |
396 | oplen = 3; | |
3d6b6a90 JG |
397 | break; |
398 | ||
399 | case BINOP_VAL: | |
400 | case UNOP_CAST: | |
401 | case UNOP_MEMVAL: | |
402 | oplen = 3; | |
403 | args = 1; | |
404 | break; | |
405 | ||
406 | case UNOP_ABS: | |
407 | case UNOP_CAP: | |
408 | case UNOP_CHR: | |
409 | case UNOP_FLOAT: | |
410 | case UNOP_HIGH: | |
411 | case UNOP_ODD: | |
412 | case UNOP_ORD: | |
413 | case UNOP_TRUNC: | |
414 | oplen = 1; | |
415 | args = 1; | |
416 | break; | |
417 | ||
2640f7e1 JG |
418 | case STRUCTOP_STRUCT: |
419 | case STRUCTOP_PTR: | |
420 | args = 1; | |
d1065385 | 421 | /* fall through */ |
3d6b6a90 JG |
422 | case OP_M2_STRING: |
423 | case OP_STRING: | |
81028ab0 FF |
424 | oplen = longest_to_int (expr->elts[endpos - 2].longconst); |
425 | oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1); | |
426 | break; | |
427 | ||
428 | case OP_BITSTRING: | |
429 | oplen = longest_to_int (expr->elts[endpos - 2].longconst); | |
430 | oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT; | |
431 | oplen = 4 + BYTES_TO_EXP_ELEM (oplen); | |
3d6b6a90 JG |
432 | break; |
433 | ||
c4413e2c FF |
434 | case OP_ARRAY: |
435 | oplen = 4; | |
436 | args = longest_to_int (expr->elts[endpos - 2].longconst); | |
437 | args -= longest_to_int (expr->elts[endpos - 3].longconst); | |
438 | args += 1; | |
439 | break; | |
440 | ||
3d6b6a90 JG |
441 | case TERNOP_COND: |
442 | args = 3; | |
443 | break; | |
444 | ||
445 | /* Modula-2 */ | |
54bbbfb4 | 446 | case MULTI_SUBSCRIPT: |
3d6b6a90 | 447 | oplen=3; |
d1065385 | 448 | args = 1 + longest_to_int (expr->elts[endpos- 2].longconst); |
3d6b6a90 JG |
449 | break; |
450 | ||
451 | case BINOP_ASSIGN_MODIFY: | |
452 | oplen = 3; | |
453 | args = 2; | |
454 | break; | |
455 | ||
456 | /* C++ */ | |
457 | case OP_THIS: | |
458 | oplen = 2; | |
459 | break; | |
460 | ||
461 | default: | |
462 | args = 1 + (i < (int) BINOP_END); | |
463 | } | |
464 | ||
465 | while (args > 0) | |
466 | { | |
467 | oplen += length_of_subexp (expr, endpos - oplen); | |
468 | args--; | |
469 | } | |
470 | ||
471 | return oplen; | |
472 | } | |
473 | ||
474 | /* Copy the subexpression ending just before index INEND in INEXPR | |
475 | into OUTEXPR, starting at index OUTBEG. | |
476 | In the process, convert it from suffix to prefix form. */ | |
477 | ||
478 | static void | |
479 | prefixify_subexp (inexpr, outexpr, inend, outbeg) | |
480 | register struct expression *inexpr; | |
481 | struct expression *outexpr; | |
482 | register int inend; | |
483 | int outbeg; | |
484 | { | |
485 | register int oplen = 1; | |
486 | register int args = 0; | |
487 | register int i; | |
488 | int *arglens; | |
489 | enum exp_opcode opcode; | |
490 | ||
491 | /* Compute how long the last operation is (in OPLEN), | |
492 | and also how many preceding subexpressions serve as | |
493 | arguments for it (in ARGS). */ | |
494 | ||
495 | opcode = inexpr->elts[inend - 1].opcode; | |
496 | switch (opcode) | |
497 | { | |
498 | /* C++ */ | |
499 | case OP_SCOPE: | |
81028ab0 FF |
500 | oplen = longest_to_int (inexpr->elts[inend - 2].longconst); |
501 | oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1); | |
3d6b6a90 JG |
502 | break; |
503 | ||
504 | case OP_LONG: | |
505 | case OP_DOUBLE: | |
506 | oplen = 4; | |
507 | break; | |
508 | ||
509 | case OP_TYPE: | |
510 | case OP_BOOL: | |
511 | case OP_VAR_VALUE: | |
512 | case OP_LAST: | |
513 | case OP_REGISTER: | |
514 | case OP_INTERNALVAR: | |
515 | oplen = 3; | |
516 | break; | |
517 | ||
518 | case OP_FUNCALL: | |
519 | oplen = 3; | |
d1065385 | 520 | args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst); |
3d6b6a90 JG |
521 | break; |
522 | ||
523 | case UNOP_MIN: | |
524 | case UNOP_MAX: | |
525 | oplen = 3; | |
3d6b6a90 JG |
526 | break; |
527 | ||
528 | case UNOP_CAST: | |
529 | case UNOP_MEMVAL: | |
530 | oplen = 3; | |
531 | args = 1; | |
532 | break; | |
533 | ||
534 | case UNOP_ABS: | |
535 | case UNOP_CAP: | |
536 | case UNOP_CHR: | |
537 | case UNOP_FLOAT: | |
538 | case UNOP_HIGH: | |
539 | case UNOP_ODD: | |
540 | case UNOP_ORD: | |
541 | case UNOP_TRUNC: | |
542 | oplen=1; | |
543 | args=1; | |
544 | break; | |
545 | ||
61c1724b | 546 | case STRUCTOP_STRUCT: |
2640f7e1 JG |
547 | case STRUCTOP_PTR: |
548 | args = 1; | |
d1065385 | 549 | /* fall through */ |
3d6b6a90 JG |
550 | case OP_M2_STRING: |
551 | case OP_STRING: | |
81028ab0 FF |
552 | oplen = longest_to_int (inexpr->elts[inend - 2].longconst); |
553 | oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1); | |
554 | break; | |
555 | ||
556 | case OP_BITSTRING: | |
557 | oplen = longest_to_int (inexpr->elts[inend - 2].longconst); | |
558 | oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT; | |
559 | oplen = 4 + BYTES_TO_EXP_ELEM (oplen); | |
3d6b6a90 JG |
560 | break; |
561 | ||
c4413e2c FF |
562 | case OP_ARRAY: |
563 | oplen = 4; | |
564 | args = longest_to_int (inexpr->elts[inend - 2].longconst); | |
565 | args -= longest_to_int (inexpr->elts[inend - 3].longconst); | |
566 | args += 1; | |
567 | break; | |
568 | ||
3d6b6a90 JG |
569 | case TERNOP_COND: |
570 | args = 3; | |
571 | break; | |
572 | ||
573 | case BINOP_ASSIGN_MODIFY: | |
574 | oplen = 3; | |
575 | args = 2; | |
576 | break; | |
577 | ||
578 | /* Modula-2 */ | |
54bbbfb4 | 579 | case MULTI_SUBSCRIPT: |
3d6b6a90 | 580 | oplen=3; |
d1065385 | 581 | args = 1 + longest_to_int (inexpr->elts[inend - 2].longconst); |
3d6b6a90 JG |
582 | break; |
583 | ||
584 | /* C++ */ | |
585 | case OP_THIS: | |
586 | oplen = 2; | |
587 | break; | |
588 | ||
589 | default: | |
590 | args = 1 + ((int) opcode < (int) BINOP_END); | |
591 | } | |
592 | ||
593 | /* Copy the final operator itself, from the end of the input | |
594 | to the beginning of the output. */ | |
595 | inend -= oplen; | |
4ed3a9ea | 596 | memcpy (&outexpr->elts[outbeg], &inexpr->elts[inend], |
81028ab0 | 597 | EXP_ELEM_TO_BYTES (oplen)); |
3d6b6a90 JG |
598 | outbeg += oplen; |
599 | ||
600 | /* Find the lengths of the arg subexpressions. */ | |
601 | arglens = (int *) alloca (args * sizeof (int)); | |
602 | for (i = args - 1; i >= 0; i--) | |
603 | { | |
604 | oplen = length_of_subexp (inexpr, inend); | |
605 | arglens[i] = oplen; | |
606 | inend -= oplen; | |
607 | } | |
608 | ||
609 | /* Now copy each subexpression, preserving the order of | |
610 | the subexpressions, but prefixifying each one. | |
611 | In this loop, inend starts at the beginning of | |
612 | the expression this level is working on | |
613 | and marches forward over the arguments. | |
614 | outbeg does similarly in the output. */ | |
615 | for (i = 0; i < args; i++) | |
616 | { | |
617 | oplen = arglens[i]; | |
618 | inend += oplen; | |
619 | prefixify_subexp (inexpr, outexpr, inend, outbeg); | |
620 | outbeg += oplen; | |
621 | } | |
622 | } | |
623 | \f | |
624 | /* This page contains the two entry points to this file. */ | |
625 | ||
626 | /* Read an expression from the string *STRINGPTR points to, | |
627 | parse it, and return a pointer to a struct expression that we malloc. | |
628 | Use block BLOCK as the lexical context for variable names; | |
629 | if BLOCK is zero, use the block of the selected stack frame. | |
630 | Meanwhile, advance *STRINGPTR to point after the expression, | |
631 | at the first nonwhite character that is not part of the expression | |
632 | (possibly a null character). | |
633 | ||
634 | If COMMA is nonzero, stop if a comma is reached. */ | |
635 | ||
636 | struct expression * | |
637 | parse_exp_1 (stringptr, block, comma) | |
638 | char **stringptr; | |
639 | struct block *block; | |
640 | int comma; | |
641 | { | |
642 | struct cleanup *old_chain; | |
643 | ||
644 | lexptr = *stringptr; | |
645 | ||
646 | paren_depth = 0; | |
647 | type_stack_depth = 0; | |
648 | ||
649 | comma_terminates = comma; | |
650 | ||
651 | if (lexptr == 0 || *lexptr == 0) | |
652 | error_no_arg ("expression to compute"); | |
653 | ||
654 | old_chain = make_cleanup (free_funcalls, 0); | |
655 | funcall_chain = 0; | |
656 | ||
657 | expression_context_block = block ? block : get_selected_block (); | |
658 | ||
659 | namecopy = (char *) alloca (strlen (lexptr) + 1); | |
660 | expout_size = 10; | |
661 | expout_ptr = 0; | |
662 | expout = (struct expression *) | |
81028ab0 | 663 | xmalloc (sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_size)); |
3d6b6a90 JG |
664 | expout->language_defn = current_language; |
665 | make_cleanup (free_current_contents, &expout); | |
666 | ||
667 | if (current_language->la_parser ()) | |
668 | current_language->la_error (NULL); | |
669 | ||
670 | discard_cleanups (old_chain); | |
54bbbfb4 FF |
671 | |
672 | /* Record the actual number of expression elements, and then | |
673 | reallocate the expression memory so that we free up any | |
674 | excess elements. */ | |
675 | ||
3d6b6a90 JG |
676 | expout->nelts = expout_ptr; |
677 | expout = (struct expression *) | |
1ab3bf1b | 678 | xrealloc ((char *) expout, |
81028ab0 | 679 | sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_ptr));; |
54bbbfb4 FF |
680 | |
681 | /* Convert expression from postfix form as generated by yacc | |
682 | parser, to a prefix form. */ | |
683 | ||
684 | DUMP_EXPRESSION (expout, stdout, "before conversion to prefix form"); | |
3d6b6a90 | 685 | prefixify_expression (expout); |
54bbbfb4 FF |
686 | DUMP_EXPRESSION (expout, stdout, "after conversion to prefix form"); |
687 | ||
3d6b6a90 JG |
688 | *stringptr = lexptr; |
689 | return expout; | |
690 | } | |
691 | ||
692 | /* Parse STRING as an expression, and complain if this fails | |
693 | to use up all of the contents of STRING. */ | |
694 | ||
695 | struct expression * | |
696 | parse_expression (string) | |
697 | char *string; | |
698 | { | |
699 | register struct expression *exp; | |
700 | exp = parse_exp_1 (&string, 0, 0); | |
701 | if (*string) | |
702 | error ("Junk after end of expression."); | |
703 | return exp; | |
704 | } | |
705 | ||
706 | void | |
707 | push_type (tp) | |
708 | enum type_pieces tp; | |
709 | { | |
710 | if (type_stack_depth == type_stack_size) | |
711 | { | |
712 | type_stack_size *= 2; | |
713 | type_stack = (union type_stack_elt *) | |
1ab3bf1b | 714 | xrealloc ((char *) type_stack, type_stack_size * sizeof (*type_stack)); |
3d6b6a90 JG |
715 | } |
716 | type_stack[type_stack_depth++].piece = tp; | |
717 | } | |
718 | ||
719 | void | |
720 | push_type_int (n) | |
721 | int n; | |
722 | { | |
723 | if (type_stack_depth == type_stack_size) | |
724 | { | |
725 | type_stack_size *= 2; | |
726 | type_stack = (union type_stack_elt *) | |
1ab3bf1b | 727 | xrealloc ((char *) type_stack, type_stack_size * sizeof (*type_stack)); |
3d6b6a90 JG |
728 | } |
729 | type_stack[type_stack_depth++].int_val = n; | |
730 | } | |
731 | ||
732 | enum type_pieces | |
733 | pop_type () | |
734 | { | |
735 | if (type_stack_depth) | |
736 | return type_stack[--type_stack_depth].piece; | |
737 | return tp_end; | |
738 | } | |
739 | ||
740 | int | |
741 | pop_type_int () | |
742 | { | |
743 | if (type_stack_depth) | |
744 | return type_stack[--type_stack_depth].int_val; | |
745 | /* "Can't happen". */ | |
746 | return 0; | |
747 | } | |
748 | ||
749 | void | |
750 | _initialize_parse () | |
751 | { | |
752 | type_stack_size = 80; | |
753 | type_stack_depth = 0; | |
754 | type_stack = (union type_stack_elt *) | |
755 | xmalloc (type_stack_size * sizeof (*type_stack)); | |
756 | } |