gdb/gdbserver/
[deliverable/binutils-gdb.git] / gdb / parse.c
1 /* Parse expressions for GDB.
2
3 Copyright (C) 1986, 1989-2001, 2004-2005, 2007-2012 Free Software
4 Foundation, Inc.
5
6 Modified from expread.y by the Department of Computer Science at the
7 State University of New York at Buffalo, 1991.
8
9 This file is part of GDB.
10
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 3 of the License, or
14 (at your option) any later version.
15
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
20
21 You should have received a copy of the GNU General Public License
22 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23
24 /* Parse an expression from text in a string,
25 and return the result as a struct expression pointer.
26 That structure contains arithmetic operations in reverse polish,
27 with constants represented by operations that are followed by special data.
28 See expression.h for the details of the format.
29 What is important here is that it can be built up sequentially
30 during the process of parsing; the lower levels of the tree always
31 come first in the result. */
32
33 #include "defs.h"
34 #include <ctype.h>
35 #include "arch-utils.h"
36 #include "gdb_string.h"
37 #include "symtab.h"
38 #include "gdbtypes.h"
39 #include "frame.h"
40 #include "expression.h"
41 #include "value.h"
42 #include "command.h"
43 #include "language.h"
44 #include "f-lang.h"
45 #include "parser-defs.h"
46 #include "gdbcmd.h"
47 #include "symfile.h" /* for overlay functions */
48 #include "inferior.h"
49 #include "doublest.h"
50 #include "gdb_assert.h"
51 #include "block.h"
52 #include "source.h"
53 #include "objfiles.h"
54 #include "exceptions.h"
55 #include "user-regs.h"
56
57 /* Standard set of definitions for printing, dumping, prefixifying,
58 * and evaluating expressions. */
59
60 const struct exp_descriptor exp_descriptor_standard =
61 {
62 print_subexp_standard,
63 operator_length_standard,
64 operator_check_standard,
65 op_name_standard,
66 dump_subexp_body_standard,
67 evaluate_subexp_standard
68 };
69 \f
70 /* Global variables declared in parser-defs.h (and commented there). */
71 struct expression *expout;
72 int expout_size;
73 int expout_ptr;
74 struct block *expression_context_block;
75 CORE_ADDR expression_context_pc;
76 struct block *innermost_block;
77 int arglist_len;
78 union type_stack_elt *type_stack;
79 int type_stack_depth, type_stack_size;
80 char *lexptr;
81 char *prev_lexptr;
82 int paren_depth;
83 int comma_terminates;
84
85 /* True if parsing an expression to find a field reference. This is
86 only used by completion. */
87 int in_parse_field;
88
89 /* The index of the last struct expression directly before a '.' or
90 '->'. This is set when parsing and is only used when completing a
91 field name. It is -1 if no dereference operation was found. */
92 static int expout_last_struct = -1;
93
94 /* A temporary buffer for identifiers, so we can null-terminate them.
95
96 We allocate this with xrealloc. parse_exp_1 used to allocate with
97 alloca, using the size of the whole expression as a conservative
98 estimate of the space needed. However, macro expansion can
99 introduce names longer than the original expression; there's no
100 practical way to know beforehand how large that might be. */
101 char *namecopy;
102 size_t namecopy_size;
103 \f
104 static int expressiondebug = 0;
105 static void
106 show_expressiondebug (struct ui_file *file, int from_tty,
107 struct cmd_list_element *c, const char *value)
108 {
109 fprintf_filtered (file, _("Expression debugging is %s.\n"), value);
110 }
111
112
113 /* Non-zero if an expression parser should set yydebug. */
114 int parser_debug;
115
116 static void
117 show_parserdebug (struct ui_file *file, int from_tty,
118 struct cmd_list_element *c, const char *value)
119 {
120 fprintf_filtered (file, _("Parser debugging is %s.\n"), value);
121 }
122
123
124 static void free_funcalls (void *ignore);
125
126 static int prefixify_expression (struct expression *);
127
128 static int prefixify_subexp (struct expression *, struct expression *, int,
129 int);
130
131 static struct expression *parse_exp_in_context (char **, struct block *, int,
132 int, int *);
133
134 void _initialize_parse (void);
135
136 /* Data structure for saving values of arglist_len for function calls whose
137 arguments contain other function calls. */
138
139 struct funcall
140 {
141 struct funcall *next;
142 int arglist_len;
143 };
144
145 static struct funcall *funcall_chain;
146
147 /* Begin counting arguments for a function call,
148 saving the data about any containing call. */
149
150 void
151 start_arglist (void)
152 {
153 struct funcall *new;
154
155 new = (struct funcall *) xmalloc (sizeof (struct funcall));
156 new->next = funcall_chain;
157 new->arglist_len = arglist_len;
158 arglist_len = 0;
159 funcall_chain = new;
160 }
161
162 /* Return the number of arguments in a function call just terminated,
163 and restore the data for the containing function call. */
164
165 int
166 end_arglist (void)
167 {
168 int val = arglist_len;
169 struct funcall *call = funcall_chain;
170
171 funcall_chain = call->next;
172 arglist_len = call->arglist_len;
173 xfree (call);
174 return val;
175 }
176
177 /* Free everything in the funcall chain.
178 Used when there is an error inside parsing. */
179
180 static void
181 free_funcalls (void *ignore)
182 {
183 struct funcall *call, *next;
184
185 for (call = funcall_chain; call; call = next)
186 {
187 next = call->next;
188 xfree (call);
189 }
190 }
191 \f
192 /* This page contains the functions for adding data to the struct expression
193 being constructed. */
194
195 /* Add one element to the end of the expression. */
196
197 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
198 a register through here. */
199
200 static void
201 write_exp_elt (const union exp_element *expelt)
202 {
203 if (expout_ptr >= expout_size)
204 {
205 expout_size *= 2;
206 expout = (struct expression *)
207 xrealloc ((char *) expout, sizeof (struct expression)
208 + EXP_ELEM_TO_BYTES (expout_size));
209 }
210 expout->elts[expout_ptr++] = *expelt;
211 }
212
213 void
214 write_exp_elt_opcode (enum exp_opcode expelt)
215 {
216 union exp_element tmp;
217
218 memset (&tmp, 0, sizeof (union exp_element));
219 tmp.opcode = expelt;
220 write_exp_elt (&tmp);
221 }
222
223 void
224 write_exp_elt_sym (struct symbol *expelt)
225 {
226 union exp_element tmp;
227
228 memset (&tmp, 0, sizeof (union exp_element));
229 tmp.symbol = expelt;
230 write_exp_elt (&tmp);
231 }
232
233 void
234 write_exp_elt_block (struct block *b)
235 {
236 union exp_element tmp;
237
238 memset (&tmp, 0, sizeof (union exp_element));
239 tmp.block = b;
240 write_exp_elt (&tmp);
241 }
242
243 void
244 write_exp_elt_objfile (struct objfile *objfile)
245 {
246 union exp_element tmp;
247
248 memset (&tmp, 0, sizeof (union exp_element));
249 tmp.objfile = objfile;
250 write_exp_elt (&tmp);
251 }
252
253 void
254 write_exp_elt_longcst (LONGEST expelt)
255 {
256 union exp_element tmp;
257
258 memset (&tmp, 0, sizeof (union exp_element));
259 tmp.longconst = expelt;
260 write_exp_elt (&tmp);
261 }
262
263 void
264 write_exp_elt_dblcst (DOUBLEST expelt)
265 {
266 union exp_element tmp;
267
268 memset (&tmp, 0, sizeof (union exp_element));
269 tmp.doubleconst = expelt;
270 write_exp_elt (&tmp);
271 }
272
273 void
274 write_exp_elt_decfloatcst (gdb_byte expelt[16])
275 {
276 union exp_element tmp;
277 int index;
278
279 for (index = 0; index < 16; index++)
280 tmp.decfloatconst[index] = expelt[index];
281
282 write_exp_elt (&tmp);
283 }
284
285 void
286 write_exp_elt_type (struct type *expelt)
287 {
288 union exp_element tmp;
289
290 memset (&tmp, 0, sizeof (union exp_element));
291 tmp.type = expelt;
292 write_exp_elt (&tmp);
293 }
294
295 void
296 write_exp_elt_intern (struct internalvar *expelt)
297 {
298 union exp_element tmp;
299
300 memset (&tmp, 0, sizeof (union exp_element));
301 tmp.internalvar = expelt;
302 write_exp_elt (&tmp);
303 }
304
305 /* Add a string constant to the end of the expression.
306
307 String constants are stored by first writing an expression element
308 that contains the length of the string, then stuffing the string
309 constant itself into however many expression elements are needed
310 to hold it, and then writing another expression element that contains
311 the length of the string. I.e. an expression element at each end of
312 the string records the string length, so you can skip over the
313 expression elements containing the actual string bytes from either
314 end of the string. Note that this also allows gdb to handle
315 strings with embedded null bytes, as is required for some languages.
316
317 Don't be fooled by the fact that the string is null byte terminated,
318 this is strictly for the convenience of debugging gdb itself.
319 Gdb does not depend up the string being null terminated, since the
320 actual length is recorded in expression elements at each end of the
321 string. The null byte is taken into consideration when computing how
322 many expression elements are required to hold the string constant, of
323 course. */
324
325
326 void
327 write_exp_string (struct stoken str)
328 {
329 int len = str.length;
330 int lenelt;
331 char *strdata;
332
333 /* Compute the number of expression elements required to hold the string
334 (including a null byte terminator), along with one expression element
335 at each end to record the actual string length (not including the
336 null byte terminator). */
337
338 lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1);
339
340 /* Ensure that we have enough available expression elements to store
341 everything. */
342
343 if ((expout_ptr + lenelt) >= expout_size)
344 {
345 expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
346 expout = (struct expression *)
347 xrealloc ((char *) expout, (sizeof (struct expression)
348 + EXP_ELEM_TO_BYTES (expout_size)));
349 }
350
351 /* Write the leading length expression element (which advances the current
352 expression element index), then write the string constant followed by a
353 terminating null byte, and then write the trailing length expression
354 element. */
355
356 write_exp_elt_longcst ((LONGEST) len);
357 strdata = (char *) &expout->elts[expout_ptr];
358 memcpy (strdata, str.ptr, len);
359 *(strdata + len) = '\0';
360 expout_ptr += lenelt - 2;
361 write_exp_elt_longcst ((LONGEST) len);
362 }
363
364 /* Add a vector of string constants to the end of the expression.
365
366 This adds an OP_STRING operation, but encodes the contents
367 differently from write_exp_string. The language is expected to
368 handle evaluation of this expression itself.
369
370 After the usual OP_STRING header, TYPE is written into the
371 expression as a long constant. The interpretation of this field is
372 up to the language evaluator.
373
374 Next, each string in VEC is written. The length is written as a
375 long constant, followed by the contents of the string. */
376
377 void
378 write_exp_string_vector (int type, struct stoken_vector *vec)
379 {
380 int i, n_slots, len;
381
382 /* Compute the size. We compute the size in number of slots to
383 avoid issues with string padding. */
384 n_slots = 0;
385 for (i = 0; i < vec->len; ++i)
386 {
387 /* One slot for the length of this element, plus the number of
388 slots needed for this string. */
389 n_slots += 1 + BYTES_TO_EXP_ELEM (vec->tokens[i].length);
390 }
391
392 /* One more slot for the type of the string. */
393 ++n_slots;
394
395 /* Now compute a phony string length. */
396 len = EXP_ELEM_TO_BYTES (n_slots) - 1;
397
398 n_slots += 4;
399 if ((expout_ptr + n_slots) >= expout_size)
400 {
401 expout_size = max (expout_size * 2, expout_ptr + n_slots + 10);
402 expout = (struct expression *)
403 xrealloc ((char *) expout, (sizeof (struct expression)
404 + EXP_ELEM_TO_BYTES (expout_size)));
405 }
406
407 write_exp_elt_opcode (OP_STRING);
408 write_exp_elt_longcst (len);
409 write_exp_elt_longcst (type);
410
411 for (i = 0; i < vec->len; ++i)
412 {
413 write_exp_elt_longcst (vec->tokens[i].length);
414 memcpy (&expout->elts[expout_ptr], vec->tokens[i].ptr,
415 vec->tokens[i].length);
416 expout_ptr += BYTES_TO_EXP_ELEM (vec->tokens[i].length);
417 }
418
419 write_exp_elt_longcst (len);
420 write_exp_elt_opcode (OP_STRING);
421 }
422
423 /* Add a bitstring constant to the end of the expression.
424
425 Bitstring constants are stored by first writing an expression element
426 that contains the length of the bitstring (in bits), then stuffing the
427 bitstring constant itself into however many expression elements are
428 needed to hold it, and then writing another expression element that
429 contains the length of the bitstring. I.e. an expression element at
430 each end of the bitstring records the bitstring length, so you can skip
431 over the expression elements containing the actual bitstring bytes from
432 either end of the bitstring. */
433
434 void
435 write_exp_bitstring (struct stoken str)
436 {
437 int bits = str.length; /* length in bits */
438 int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
439 int lenelt;
440 char *strdata;
441
442 /* Compute the number of expression elements required to hold the bitstring,
443 along with one expression element at each end to record the actual
444 bitstring length in bits. */
445
446 lenelt = 2 + BYTES_TO_EXP_ELEM (len);
447
448 /* Ensure that we have enough available expression elements to store
449 everything. */
450
451 if ((expout_ptr + lenelt) >= expout_size)
452 {
453 expout_size = max (expout_size * 2, expout_ptr + lenelt + 10);
454 expout = (struct expression *)
455 xrealloc ((char *) expout, (sizeof (struct expression)
456 + EXP_ELEM_TO_BYTES (expout_size)));
457 }
458
459 /* Write the leading length expression element (which advances the current
460 expression element index), then write the bitstring constant, and then
461 write the trailing length expression element. */
462
463 write_exp_elt_longcst ((LONGEST) bits);
464 strdata = (char *) &expout->elts[expout_ptr];
465 memcpy (strdata, str.ptr, len);
466 expout_ptr += lenelt - 2;
467 write_exp_elt_longcst ((LONGEST) bits);
468 }
469
470 /* Add the appropriate elements for a minimal symbol to the end of
471 the expression. */
472
473 void
474 write_exp_msymbol (struct minimal_symbol *msymbol)
475 {
476 struct objfile *objfile = msymbol_objfile (msymbol);
477 struct gdbarch *gdbarch = get_objfile_arch (objfile);
478
479 CORE_ADDR addr = SYMBOL_VALUE_ADDRESS (msymbol);
480 struct obj_section *section = SYMBOL_OBJ_SECTION (msymbol);
481 enum minimal_symbol_type type = MSYMBOL_TYPE (msymbol);
482 CORE_ADDR pc;
483
484 /* The minimal symbol might point to a function descriptor;
485 resolve it to the actual code address instead. */
486 pc = gdbarch_convert_from_func_ptr_addr (gdbarch, addr, &current_target);
487 if (pc != addr)
488 {
489 struct minimal_symbol *ifunc_msym = lookup_minimal_symbol_by_pc (pc);
490
491 /* In this case, assume we have a code symbol instead of
492 a data symbol. */
493
494 if (ifunc_msym != NULL && MSYMBOL_TYPE (ifunc_msym) == mst_text_gnu_ifunc
495 && SYMBOL_VALUE_ADDRESS (ifunc_msym) == pc)
496 {
497 /* A function descriptor has been resolved but PC is still in the
498 STT_GNU_IFUNC resolver body (such as because inferior does not
499 run to be able to call it). */
500
501 type = mst_text_gnu_ifunc;
502 }
503 else
504 type = mst_text;
505 section = NULL;
506 addr = pc;
507 }
508
509 if (overlay_debugging)
510 addr = symbol_overlayed_address (addr, section);
511
512 write_exp_elt_opcode (OP_LONG);
513 /* Let's make the type big enough to hold a 64-bit address. */
514 write_exp_elt_type (objfile_type (objfile)->builtin_core_addr);
515 write_exp_elt_longcst ((LONGEST) addr);
516 write_exp_elt_opcode (OP_LONG);
517
518 if (section && section->the_bfd_section->flags & SEC_THREAD_LOCAL)
519 {
520 write_exp_elt_opcode (UNOP_MEMVAL_TLS);
521 write_exp_elt_objfile (objfile);
522 write_exp_elt_type (objfile_type (objfile)->nodebug_tls_symbol);
523 write_exp_elt_opcode (UNOP_MEMVAL_TLS);
524 return;
525 }
526
527 write_exp_elt_opcode (UNOP_MEMVAL);
528 switch (type)
529 {
530 case mst_text:
531 case mst_file_text:
532 case mst_solib_trampoline:
533 write_exp_elt_type (objfile_type (objfile)->nodebug_text_symbol);
534 break;
535
536 case mst_text_gnu_ifunc:
537 write_exp_elt_type (objfile_type (objfile)
538 ->nodebug_text_gnu_ifunc_symbol);
539 break;
540
541 case mst_data:
542 case mst_file_data:
543 case mst_bss:
544 case mst_file_bss:
545 write_exp_elt_type (objfile_type (objfile)->nodebug_data_symbol);
546 break;
547
548 case mst_slot_got_plt:
549 write_exp_elt_type (objfile_type (objfile)->nodebug_got_plt_symbol);
550 break;
551
552 default:
553 write_exp_elt_type (objfile_type (objfile)->nodebug_unknown_symbol);
554 break;
555 }
556 write_exp_elt_opcode (UNOP_MEMVAL);
557 }
558
559 /* Mark the current index as the starting location of a structure
560 expression. This is used when completing on field names. */
561
562 void
563 mark_struct_expression (void)
564 {
565 expout_last_struct = expout_ptr;
566 }
567
568 \f
569 /* Recognize tokens that start with '$'. These include:
570
571 $regname A native register name or a "standard
572 register name".
573
574 $variable A convenience variable with a name chosen
575 by the user.
576
577 $digits Value history with index <digits>, starting
578 from the first value which has index 1.
579
580 $$digits Value history with index <digits> relative
581 to the last value. I.e. $$0 is the last
582 value, $$1 is the one previous to that, $$2
583 is the one previous to $$1, etc.
584
585 $ | $0 | $$0 The last value in the value history.
586
587 $$ An abbreviation for the second to the last
588 value in the value history, I.e. $$1 */
589
590 void
591 write_dollar_variable (struct stoken str)
592 {
593 struct symbol *sym = NULL;
594 struct minimal_symbol *msym = NULL;
595 struct internalvar *isym = NULL;
596
597 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
598 and $$digits (equivalent to $<-digits> if you could type that). */
599
600 int negate = 0;
601 int i = 1;
602 /* Double dollar means negate the number and add -1 as well.
603 Thus $$ alone means -1. */
604 if (str.length >= 2 && str.ptr[1] == '$')
605 {
606 negate = 1;
607 i = 2;
608 }
609 if (i == str.length)
610 {
611 /* Just dollars (one or two). */
612 i = -negate;
613 goto handle_last;
614 }
615 /* Is the rest of the token digits? */
616 for (; i < str.length; i++)
617 if (!(str.ptr[i] >= '0' && str.ptr[i] <= '9'))
618 break;
619 if (i == str.length)
620 {
621 i = atoi (str.ptr + 1 + negate);
622 if (negate)
623 i = -i;
624 goto handle_last;
625 }
626
627 /* Handle tokens that refer to machine registers:
628 $ followed by a register name. */
629 i = user_reg_map_name_to_regnum (parse_gdbarch,
630 str.ptr + 1, str.length - 1);
631 if (i >= 0)
632 goto handle_register;
633
634 /* Any names starting with $ are probably debugger internal variables. */
635
636 isym = lookup_only_internalvar (copy_name (str) + 1);
637 if (isym)
638 {
639 write_exp_elt_opcode (OP_INTERNALVAR);
640 write_exp_elt_intern (isym);
641 write_exp_elt_opcode (OP_INTERNALVAR);
642 return;
643 }
644
645 /* On some systems, such as HP-UX and hppa-linux, certain system routines
646 have names beginning with $ or $$. Check for those, first. */
647
648 sym = lookup_symbol (copy_name (str), (struct block *) NULL,
649 VAR_DOMAIN, (int *) NULL);
650 if (sym)
651 {
652 write_exp_elt_opcode (OP_VAR_VALUE);
653 write_exp_elt_block (block_found); /* set by lookup_symbol */
654 write_exp_elt_sym (sym);
655 write_exp_elt_opcode (OP_VAR_VALUE);
656 return;
657 }
658 msym = lookup_minimal_symbol (copy_name (str), NULL, NULL);
659 if (msym)
660 {
661 write_exp_msymbol (msym);
662 return;
663 }
664
665 /* Any other names are assumed to be debugger internal variables. */
666
667 write_exp_elt_opcode (OP_INTERNALVAR);
668 write_exp_elt_intern (create_internalvar (copy_name (str) + 1));
669 write_exp_elt_opcode (OP_INTERNALVAR);
670 return;
671 handle_last:
672 write_exp_elt_opcode (OP_LAST);
673 write_exp_elt_longcst ((LONGEST) i);
674 write_exp_elt_opcode (OP_LAST);
675 return;
676 handle_register:
677 write_exp_elt_opcode (OP_REGISTER);
678 str.length--;
679 str.ptr++;
680 write_exp_string (str);
681 write_exp_elt_opcode (OP_REGISTER);
682 return;
683 }
684
685
686 char *
687 find_template_name_end (char *p)
688 {
689 int depth = 1;
690 int just_seen_right = 0;
691 int just_seen_colon = 0;
692 int just_seen_space = 0;
693
694 if (!p || (*p != '<'))
695 return 0;
696
697 while (*++p)
698 {
699 switch (*p)
700 {
701 case '\'':
702 case '\"':
703 case '{':
704 case '}':
705 /* In future, may want to allow these?? */
706 return 0;
707 case '<':
708 depth++; /* start nested template */
709 if (just_seen_colon || just_seen_right || just_seen_space)
710 return 0; /* but not after : or :: or > or space */
711 break;
712 case '>':
713 if (just_seen_colon || just_seen_right)
714 return 0; /* end a (nested?) template */
715 just_seen_right = 1; /* but not after : or :: */
716 if (--depth == 0) /* also disallow >>, insist on > > */
717 return ++p; /* if outermost ended, return */
718 break;
719 case ':':
720 if (just_seen_space || (just_seen_colon > 1))
721 return 0; /* nested class spec coming up */
722 just_seen_colon++; /* we allow :: but not :::: */
723 break;
724 case ' ':
725 break;
726 default:
727 if (!((*p >= 'a' && *p <= 'z') || /* allow token chars */
728 (*p >= 'A' && *p <= 'Z') ||
729 (*p >= '0' && *p <= '9') ||
730 (*p == '_') || (*p == ',') || /* commas for template args */
731 (*p == '&') || (*p == '*') || /* pointer and ref types */
732 (*p == '(') || (*p == ')') || /* function types */
733 (*p == '[') || (*p == ']'))) /* array types */
734 return 0;
735 }
736 if (*p != ' ')
737 just_seen_space = 0;
738 if (*p != ':')
739 just_seen_colon = 0;
740 if (*p != '>')
741 just_seen_right = 0;
742 }
743 return 0;
744 }
745 \f
746
747
748 /* Return a null-terminated temporary copy of the name
749 of a string token. */
750
751 char *
752 copy_name (struct stoken token)
753 {
754 /* Make sure there's enough space for the token. */
755 if (namecopy_size < token.length + 1)
756 {
757 namecopy_size = token.length + 1;
758 namecopy = xrealloc (namecopy, token.length + 1);
759 }
760
761 memcpy (namecopy, token.ptr, token.length);
762 namecopy[token.length] = 0;
763
764 return namecopy;
765 }
766 \f
767 /* Reverse an expression from suffix form (in which it is constructed)
768 to prefix form (in which we can conveniently print or execute it).
769 Ordinarily this always returns -1. However, if EXPOUT_LAST_STRUCT
770 is not -1 (i.e., we are trying to complete a field name), it will
771 return the index of the subexpression which is the left-hand-side
772 of the struct operation at EXPOUT_LAST_STRUCT. */
773
774 static int
775 prefixify_expression (struct expression *expr)
776 {
777 int len = sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts);
778 struct expression *temp;
779 int inpos = expr->nelts, outpos = 0;
780
781 temp = (struct expression *) alloca (len);
782
783 /* Copy the original expression into temp. */
784 memcpy (temp, expr, len);
785
786 return prefixify_subexp (temp, expr, inpos, outpos);
787 }
788
789 /* Return the number of exp_elements in the postfix subexpression
790 of EXPR whose operator is at index ENDPOS - 1 in EXPR. */
791
792 int
793 length_of_subexp (struct expression *expr, int endpos)
794 {
795 int oplen, args;
796
797 operator_length (expr, endpos, &oplen, &args);
798
799 while (args > 0)
800 {
801 oplen += length_of_subexp (expr, endpos - oplen);
802 args--;
803 }
804
805 return oplen;
806 }
807
808 /* Sets *OPLENP to the length of the operator whose (last) index is
809 ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
810 operator takes. */
811
812 void
813 operator_length (const struct expression *expr, int endpos, int *oplenp,
814 int *argsp)
815 {
816 expr->language_defn->la_exp_desc->operator_length (expr, endpos,
817 oplenp, argsp);
818 }
819
820 /* Default value for operator_length in exp_descriptor vectors. */
821
822 void
823 operator_length_standard (const struct expression *expr, int endpos,
824 int *oplenp, int *argsp)
825 {
826 int oplen = 1;
827 int args = 0;
828 enum f90_range_type range_type;
829 int i;
830
831 if (endpos < 1)
832 error (_("?error in operator_length_standard"));
833
834 i = (int) expr->elts[endpos - 1].opcode;
835
836 switch (i)
837 {
838 /* C++ */
839 case OP_SCOPE:
840 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
841 oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1);
842 break;
843
844 case OP_LONG:
845 case OP_DOUBLE:
846 case OP_DECFLOAT:
847 case OP_VAR_VALUE:
848 oplen = 4;
849 break;
850
851 case OP_TYPE:
852 case OP_BOOL:
853 case OP_LAST:
854 case OP_INTERNALVAR:
855 case OP_VAR_ENTRY_VALUE:
856 oplen = 3;
857 break;
858
859 case OP_COMPLEX:
860 oplen = 3;
861 args = 2;
862 break;
863
864 case OP_FUNCALL:
865 case OP_F77_UNDETERMINED_ARGLIST:
866 oplen = 3;
867 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
868 break;
869
870 case TYPE_INSTANCE:
871 oplen = 4 + longest_to_int (expr->elts[endpos - 2].longconst);
872 args = 1;
873 break;
874
875 case OP_OBJC_MSGCALL: /* Objective C message (method) call. */
876 oplen = 4;
877 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
878 break;
879
880 case UNOP_MAX:
881 case UNOP_MIN:
882 oplen = 3;
883 break;
884
885 case BINOP_VAL:
886 case UNOP_CAST:
887 case UNOP_DYNAMIC_CAST:
888 case UNOP_REINTERPRET_CAST:
889 case UNOP_MEMVAL:
890 oplen = 3;
891 args = 1;
892 break;
893
894 case UNOP_MEMVAL_TLS:
895 oplen = 4;
896 args = 1;
897 break;
898
899 case UNOP_ABS:
900 case UNOP_CAP:
901 case UNOP_CHR:
902 case UNOP_FLOAT:
903 case UNOP_HIGH:
904 case UNOP_ODD:
905 case UNOP_ORD:
906 case UNOP_TRUNC:
907 oplen = 1;
908 args = 1;
909 break;
910
911 case OP_ADL_FUNC:
912 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
913 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
914 oplen++;
915 oplen++;
916 break;
917
918 case OP_LABELED:
919 case STRUCTOP_STRUCT:
920 case STRUCTOP_PTR:
921 args = 1;
922 /* fall through */
923 case OP_REGISTER:
924 case OP_M2_STRING:
925 case OP_STRING:
926 case OP_OBJC_NSSTRING: /* Objective C Foundation Class
927 NSString constant. */
928 case OP_OBJC_SELECTOR: /* Objective C "@selector" pseudo-op. */
929 case OP_NAME:
930 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
931 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
932 break;
933
934 case OP_BITSTRING:
935 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
936 oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
937 oplen = 4 + BYTES_TO_EXP_ELEM (oplen);
938 break;
939
940 case OP_ARRAY:
941 oplen = 4;
942 args = longest_to_int (expr->elts[endpos - 2].longconst);
943 args -= longest_to_int (expr->elts[endpos - 3].longconst);
944 args += 1;
945 break;
946
947 case TERNOP_COND:
948 case TERNOP_SLICE:
949 case TERNOP_SLICE_COUNT:
950 args = 3;
951 break;
952
953 /* Modula-2 */
954 case MULTI_SUBSCRIPT:
955 oplen = 3;
956 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
957 break;
958
959 case BINOP_ASSIGN_MODIFY:
960 oplen = 3;
961 args = 2;
962 break;
963
964 /* C++ */
965 case OP_THIS:
966 oplen = 2;
967 break;
968
969 case OP_F90_RANGE:
970 oplen = 3;
971
972 range_type = longest_to_int (expr->elts[endpos - 2].longconst);
973 switch (range_type)
974 {
975 case LOW_BOUND_DEFAULT:
976 case HIGH_BOUND_DEFAULT:
977 args = 1;
978 break;
979 case BOTH_BOUND_DEFAULT:
980 args = 0;
981 break;
982 case NONE_BOUND_DEFAULT:
983 args = 2;
984 break;
985 }
986
987 break;
988
989 default:
990 args = 1 + (i < (int) BINOP_END);
991 }
992
993 *oplenp = oplen;
994 *argsp = args;
995 }
996
997 /* Copy the subexpression ending just before index INEND in INEXPR
998 into OUTEXPR, starting at index OUTBEG.
999 In the process, convert it from suffix to prefix form.
1000 If EXPOUT_LAST_STRUCT is -1, then this function always returns -1.
1001 Otherwise, it returns the index of the subexpression which is the
1002 left-hand-side of the expression at EXPOUT_LAST_STRUCT. */
1003
1004 static int
1005 prefixify_subexp (struct expression *inexpr,
1006 struct expression *outexpr, int inend, int outbeg)
1007 {
1008 int oplen;
1009 int args;
1010 int i;
1011 int *arglens;
1012 int result = -1;
1013
1014 operator_length (inexpr, inend, &oplen, &args);
1015
1016 /* Copy the final operator itself, from the end of the input
1017 to the beginning of the output. */
1018 inend -= oplen;
1019 memcpy (&outexpr->elts[outbeg], &inexpr->elts[inend],
1020 EXP_ELEM_TO_BYTES (oplen));
1021 outbeg += oplen;
1022
1023 if (expout_last_struct == inend)
1024 result = outbeg - oplen;
1025
1026 /* Find the lengths of the arg subexpressions. */
1027 arglens = (int *) alloca (args * sizeof (int));
1028 for (i = args - 1; i >= 0; i--)
1029 {
1030 oplen = length_of_subexp (inexpr, inend);
1031 arglens[i] = oplen;
1032 inend -= oplen;
1033 }
1034
1035 /* Now copy each subexpression, preserving the order of
1036 the subexpressions, but prefixifying each one.
1037 In this loop, inend starts at the beginning of
1038 the expression this level is working on
1039 and marches forward over the arguments.
1040 outbeg does similarly in the output. */
1041 for (i = 0; i < args; i++)
1042 {
1043 int r;
1044
1045 oplen = arglens[i];
1046 inend += oplen;
1047 r = prefixify_subexp (inexpr, outexpr, inend, outbeg);
1048 if (r != -1)
1049 {
1050 /* Return immediately. We probably have only parsed a
1051 partial expression, so we don't want to try to reverse
1052 the other operands. */
1053 return r;
1054 }
1055 outbeg += oplen;
1056 }
1057
1058 return result;
1059 }
1060 \f
1061 /* Read an expression from the string *STRINGPTR points to,
1062 parse it, and return a pointer to a struct expression that we malloc.
1063 Use block BLOCK as the lexical context for variable names;
1064 if BLOCK is zero, use the block of the selected stack frame.
1065 Meanwhile, advance *STRINGPTR to point after the expression,
1066 at the first nonwhite character that is not part of the expression
1067 (possibly a null character).
1068
1069 If COMMA is nonzero, stop if a comma is reached. */
1070
1071 struct expression *
1072 parse_exp_1 (char **stringptr, struct block *block, int comma)
1073 {
1074 return parse_exp_in_context (stringptr, block, comma, 0, NULL);
1075 }
1076
1077 /* As for parse_exp_1, except that if VOID_CONTEXT_P, then
1078 no value is expected from the expression.
1079 OUT_SUBEXP is set when attempting to complete a field name; in this
1080 case it is set to the index of the subexpression on the
1081 left-hand-side of the struct op. If not doing such completion, it
1082 is left untouched. */
1083
1084 static struct expression *
1085 parse_exp_in_context (char **stringptr, struct block *block, int comma,
1086 int void_context_p, int *out_subexp)
1087 {
1088 volatile struct gdb_exception except;
1089 struct cleanup *old_chain;
1090 const struct language_defn *lang = NULL;
1091 int subexp;
1092
1093 lexptr = *stringptr;
1094 prev_lexptr = NULL;
1095
1096 paren_depth = 0;
1097 type_stack_depth = 0;
1098 expout_last_struct = -1;
1099
1100 comma_terminates = comma;
1101
1102 if (lexptr == 0 || *lexptr == 0)
1103 error_no_arg (_("expression to compute"));
1104
1105 old_chain = make_cleanup (free_funcalls, 0 /*ignore*/);
1106 funcall_chain = 0;
1107
1108 expression_context_block = block;
1109
1110 /* If no context specified, try using the current frame, if any. */
1111 if (!expression_context_block)
1112 expression_context_block = get_selected_block (&expression_context_pc);
1113 else
1114 expression_context_pc = BLOCK_START (expression_context_block);
1115
1116 /* Fall back to using the current source static context, if any. */
1117
1118 if (!expression_context_block)
1119 {
1120 struct symtab_and_line cursal = get_current_source_symtab_and_line ();
1121 if (cursal.symtab)
1122 expression_context_block
1123 = BLOCKVECTOR_BLOCK (BLOCKVECTOR (cursal.symtab), STATIC_BLOCK);
1124 if (expression_context_block)
1125 expression_context_pc = BLOCK_START (expression_context_block);
1126 }
1127
1128 if (language_mode == language_mode_auto && block != NULL)
1129 {
1130 /* Find the language associated to the given context block.
1131 Default to the current language if it can not be determined.
1132
1133 Note that using the language corresponding to the current frame
1134 can sometimes give unexpected results. For instance, this
1135 routine is often called several times during the inferior
1136 startup phase to re-parse breakpoint expressions after
1137 a new shared library has been loaded. The language associated
1138 to the current frame at this moment is not relevant for
1139 the breakpoint. Using it would therefore be silly, so it seems
1140 better to rely on the current language rather than relying on
1141 the current frame language to parse the expression. That's why
1142 we do the following language detection only if the context block
1143 has been specifically provided. */
1144 struct symbol *func = block_linkage_function (block);
1145
1146 if (func != NULL)
1147 lang = language_def (SYMBOL_LANGUAGE (func));
1148 if (lang == NULL || lang->la_language == language_unknown)
1149 lang = current_language;
1150 }
1151 else
1152 lang = current_language;
1153
1154 expout_size = 10;
1155 expout_ptr = 0;
1156 expout = (struct expression *)
1157 xmalloc (sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_size));
1158 expout->language_defn = lang;
1159 expout->gdbarch = get_current_arch ();
1160
1161 TRY_CATCH (except, RETURN_MASK_ALL)
1162 {
1163 if (lang->la_parser ())
1164 lang->la_error (NULL);
1165 }
1166 if (except.reason < 0)
1167 {
1168 if (! in_parse_field)
1169 {
1170 xfree (expout);
1171 throw_exception (except);
1172 }
1173 }
1174
1175 discard_cleanups (old_chain);
1176
1177 /* Record the actual number of expression elements, and then
1178 reallocate the expression memory so that we free up any
1179 excess elements. */
1180
1181 expout->nelts = expout_ptr;
1182 expout = (struct expression *)
1183 xrealloc ((char *) expout,
1184 sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_ptr));
1185
1186 /* Convert expression from postfix form as generated by yacc
1187 parser, to a prefix form. */
1188
1189 if (expressiondebug)
1190 dump_raw_expression (expout, gdb_stdlog,
1191 "before conversion to prefix form");
1192
1193 subexp = prefixify_expression (expout);
1194 if (out_subexp)
1195 *out_subexp = subexp;
1196
1197 lang->la_post_parser (&expout, void_context_p);
1198
1199 if (expressiondebug)
1200 dump_prefix_expression (expout, gdb_stdlog);
1201
1202 *stringptr = lexptr;
1203 return expout;
1204 }
1205
1206 /* Parse STRING as an expression, and complain if this fails
1207 to use up all of the contents of STRING. */
1208
1209 struct expression *
1210 parse_expression (char *string)
1211 {
1212 struct expression *exp;
1213
1214 exp = parse_exp_1 (&string, 0, 0);
1215 if (*string)
1216 error (_("Junk after end of expression."));
1217 return exp;
1218 }
1219
1220 /* Parse STRING as an expression. If parsing ends in the middle of a
1221 field reference, return the type of the left-hand-side of the
1222 reference; furthermore, if the parsing ends in the field name,
1223 return the field name in *NAME. If the parsing ends in the middle
1224 of a field reference, but the reference is somehow invalid, throw
1225 an exception. In all other cases, return NULL. Returned non-NULL
1226 *NAME must be freed by the caller. */
1227
1228 struct type *
1229 parse_field_expression (char *string, char **name)
1230 {
1231 struct expression *exp = NULL;
1232 struct value *val;
1233 int subexp;
1234 volatile struct gdb_exception except;
1235
1236 TRY_CATCH (except, RETURN_MASK_ERROR)
1237 {
1238 in_parse_field = 1;
1239 exp = parse_exp_in_context (&string, 0, 0, 0, &subexp);
1240 }
1241 in_parse_field = 0;
1242 if (except.reason < 0 || ! exp)
1243 return NULL;
1244 if (expout_last_struct == -1)
1245 {
1246 xfree (exp);
1247 return NULL;
1248 }
1249
1250 *name = extract_field_op (exp, &subexp);
1251 if (!*name)
1252 {
1253 xfree (exp);
1254 return NULL;
1255 }
1256
1257 /* This might throw an exception. If so, we want to let it
1258 propagate. */
1259 val = evaluate_subexpression_type (exp, subexp);
1260 /* (*NAME) is a part of the EXP memory block freed below. */
1261 *name = xstrdup (*name);
1262 xfree (exp);
1263
1264 return value_type (val);
1265 }
1266
1267 /* A post-parser that does nothing. */
1268
1269 void
1270 null_post_parser (struct expression **exp, int void_context_p)
1271 {
1272 }
1273
1274 /* Parse floating point value P of length LEN.
1275 Return 0 (false) if invalid, 1 (true) if valid.
1276 The successfully parsed number is stored in D.
1277 *SUFFIX points to the suffix of the number in P.
1278
1279 NOTE: This accepts the floating point syntax that sscanf accepts. */
1280
1281 int
1282 parse_float (const char *p, int len, DOUBLEST *d, const char **suffix)
1283 {
1284 char *copy;
1285 char *s;
1286 int n, num;
1287
1288 copy = xmalloc (len + 1);
1289 memcpy (copy, p, len);
1290 copy[len] = 0;
1291
1292 num = sscanf (copy, "%" DOUBLEST_SCAN_FORMAT "%n", d, &n);
1293 xfree (copy);
1294
1295 /* The sscanf man page suggests not making any assumptions on the effect
1296 of %n on the result, so we don't.
1297 That is why we simply test num == 0. */
1298 if (num == 0)
1299 return 0;
1300
1301 *suffix = p + n;
1302 return 1;
1303 }
1304
1305 /* Parse floating point value P of length LEN, using the C syntax for floats.
1306 Return 0 (false) if invalid, 1 (true) if valid.
1307 The successfully parsed number is stored in *D.
1308 Its type is taken from builtin_type (gdbarch) and is stored in *T. */
1309
1310 int
1311 parse_c_float (struct gdbarch *gdbarch, const char *p, int len,
1312 DOUBLEST *d, struct type **t)
1313 {
1314 const char *suffix;
1315 int suffix_len;
1316 const struct builtin_type *builtin_types = builtin_type (gdbarch);
1317
1318 if (! parse_float (p, len, d, &suffix))
1319 return 0;
1320
1321 suffix_len = p + len - suffix;
1322
1323 if (suffix_len == 0)
1324 *t = builtin_types->builtin_double;
1325 else if (suffix_len == 1)
1326 {
1327 /* Handle suffixes: 'f' for float, 'l' for long double. */
1328 if (tolower (*suffix) == 'f')
1329 *t = builtin_types->builtin_float;
1330 else if (tolower (*suffix) == 'l')
1331 *t = builtin_types->builtin_long_double;
1332 else
1333 return 0;
1334 }
1335 else
1336 return 0;
1337
1338 return 1;
1339 }
1340 \f
1341 /* Stuff for maintaining a stack of types. Currently just used by C, but
1342 probably useful for any language which declares its types "backwards". */
1343
1344 static void
1345 check_type_stack_depth (void)
1346 {
1347 if (type_stack_depth == type_stack_size)
1348 {
1349 type_stack_size *= 2;
1350 type_stack = (union type_stack_elt *)
1351 xrealloc ((char *) type_stack, type_stack_size * sizeof (*type_stack));
1352 }
1353 }
1354
1355 void
1356 push_type (enum type_pieces tp)
1357 {
1358 check_type_stack_depth ();
1359 type_stack[type_stack_depth++].piece = tp;
1360 }
1361
1362 void
1363 push_type_int (int n)
1364 {
1365 check_type_stack_depth ();
1366 type_stack[type_stack_depth++].int_val = n;
1367 }
1368
1369 void
1370 push_type_address_space (char *string)
1371 {
1372 push_type_int (address_space_name_to_int (parse_gdbarch, string));
1373 }
1374
1375 enum type_pieces
1376 pop_type (void)
1377 {
1378 if (type_stack_depth)
1379 return type_stack[--type_stack_depth].piece;
1380 return tp_end;
1381 }
1382
1383 int
1384 pop_type_int (void)
1385 {
1386 if (type_stack_depth)
1387 return type_stack[--type_stack_depth].int_val;
1388 /* "Can't happen". */
1389 return 0;
1390 }
1391
1392 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1393 as modified by all the stuff on the stack. */
1394 struct type *
1395 follow_types (struct type *follow_type)
1396 {
1397 int done = 0;
1398 int make_const = 0;
1399 int make_volatile = 0;
1400 int make_addr_space = 0;
1401 int array_size;
1402
1403 while (!done)
1404 switch (pop_type ())
1405 {
1406 case tp_end:
1407 done = 1;
1408 if (make_const)
1409 follow_type = make_cv_type (make_const,
1410 TYPE_VOLATILE (follow_type),
1411 follow_type, 0);
1412 if (make_volatile)
1413 follow_type = make_cv_type (TYPE_CONST (follow_type),
1414 make_volatile,
1415 follow_type, 0);
1416 if (make_addr_space)
1417 follow_type = make_type_with_address_space (follow_type,
1418 make_addr_space);
1419 make_const = make_volatile = 0;
1420 make_addr_space = 0;
1421 break;
1422 case tp_const:
1423 make_const = 1;
1424 break;
1425 case tp_volatile:
1426 make_volatile = 1;
1427 break;
1428 case tp_space_identifier:
1429 make_addr_space = pop_type_int ();
1430 break;
1431 case tp_pointer:
1432 follow_type = lookup_pointer_type (follow_type);
1433 if (make_const)
1434 follow_type = make_cv_type (make_const,
1435 TYPE_VOLATILE (follow_type),
1436 follow_type, 0);
1437 if (make_volatile)
1438 follow_type = make_cv_type (TYPE_CONST (follow_type),
1439 make_volatile,
1440 follow_type, 0);
1441 if (make_addr_space)
1442 follow_type = make_type_with_address_space (follow_type,
1443 make_addr_space);
1444 make_const = make_volatile = 0;
1445 make_addr_space = 0;
1446 break;
1447 case tp_reference:
1448 follow_type = lookup_reference_type (follow_type);
1449 if (make_const)
1450 follow_type = make_cv_type (make_const,
1451 TYPE_VOLATILE (follow_type),
1452 follow_type, 0);
1453 if (make_volatile)
1454 follow_type = make_cv_type (TYPE_CONST (follow_type),
1455 make_volatile,
1456 follow_type, 0);
1457 if (make_addr_space)
1458 follow_type = make_type_with_address_space (follow_type,
1459 make_addr_space);
1460 make_const = make_volatile = 0;
1461 make_addr_space = 0;
1462 break;
1463 case tp_array:
1464 array_size = pop_type_int ();
1465 /* FIXME-type-allocation: need a way to free this type when we are
1466 done with it. */
1467 follow_type =
1468 lookup_array_range_type (follow_type,
1469 0, array_size >= 0 ? array_size - 1 : 0);
1470 if (array_size < 0)
1471 TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (follow_type) = 1;
1472 break;
1473 case tp_function:
1474 /* FIXME-type-allocation: need a way to free this type when we are
1475 done with it. */
1476 follow_type = lookup_function_type (follow_type);
1477 break;
1478 }
1479 return follow_type;
1480 }
1481 \f
1482 /* This function avoids direct calls to fprintf
1483 in the parser generated debug code. */
1484 void
1485 parser_fprintf (FILE *x, const char *y, ...)
1486 {
1487 va_list args;
1488
1489 va_start (args, y);
1490 if (x == stderr)
1491 vfprintf_unfiltered (gdb_stderr, y, args);
1492 else
1493 {
1494 fprintf_unfiltered (gdb_stderr, " Unknown FILE used.\n");
1495 vfprintf_unfiltered (gdb_stderr, y, args);
1496 }
1497 va_end (args);
1498 }
1499
1500 /* Implementation of the exp_descriptor method operator_check. */
1501
1502 int
1503 operator_check_standard (struct expression *exp, int pos,
1504 int (*objfile_func) (struct objfile *objfile,
1505 void *data),
1506 void *data)
1507 {
1508 const union exp_element *const elts = exp->elts;
1509 struct type *type = NULL;
1510 struct objfile *objfile = NULL;
1511
1512 /* Extended operators should have been already handled by exp_descriptor
1513 iterate method of its specific language. */
1514 gdb_assert (elts[pos].opcode < OP_EXTENDED0);
1515
1516 /* Track the callers of write_exp_elt_type for this table. */
1517
1518 switch (elts[pos].opcode)
1519 {
1520 case BINOP_VAL:
1521 case OP_COMPLEX:
1522 case OP_DECFLOAT:
1523 case OP_DOUBLE:
1524 case OP_LONG:
1525 case OP_SCOPE:
1526 case OP_TYPE:
1527 case UNOP_CAST:
1528 case UNOP_DYNAMIC_CAST:
1529 case UNOP_REINTERPRET_CAST:
1530 case UNOP_MAX:
1531 case UNOP_MEMVAL:
1532 case UNOP_MIN:
1533 type = elts[pos + 1].type;
1534 break;
1535
1536 case TYPE_INSTANCE:
1537 {
1538 LONGEST arg, nargs = elts[pos + 1].longconst;
1539
1540 for (arg = 0; arg < nargs; arg++)
1541 {
1542 struct type *type = elts[pos + 2 + arg].type;
1543 struct objfile *objfile = TYPE_OBJFILE (type);
1544
1545 if (objfile && (*objfile_func) (objfile, data))
1546 return 1;
1547 }
1548 }
1549 break;
1550
1551 case UNOP_MEMVAL_TLS:
1552 objfile = elts[pos + 1].objfile;
1553 type = elts[pos + 2].type;
1554 break;
1555
1556 case OP_VAR_VALUE:
1557 {
1558 const struct block *const block = elts[pos + 1].block;
1559 const struct symbol *const symbol = elts[pos + 2].symbol;
1560
1561 /* Check objfile where the variable itself is placed.
1562 SYMBOL_OBJ_SECTION (symbol) may be NULL. */
1563 if ((*objfile_func) (SYMBOL_SYMTAB (symbol)->objfile, data))
1564 return 1;
1565
1566 /* Check objfile where is placed the code touching the variable. */
1567 objfile = lookup_objfile_from_block (block);
1568
1569 type = SYMBOL_TYPE (symbol);
1570 }
1571 break;
1572 }
1573
1574 /* Invoke callbacks for TYPE and OBJFILE if they were set as non-NULL. */
1575
1576 if (type && TYPE_OBJFILE (type)
1577 && (*objfile_func) (TYPE_OBJFILE (type), data))
1578 return 1;
1579 if (objfile && (*objfile_func) (objfile, data))
1580 return 1;
1581
1582 return 0;
1583 }
1584
1585 /* Call OBJFILE_FUNC for any TYPE and OBJFILE found being referenced by EXP.
1586 The functions are never called with NULL OBJFILE. Functions get passed an
1587 arbitrary caller supplied DATA pointer. If any of the functions returns
1588 non-zero value then (any other) non-zero value is immediately returned to
1589 the caller. Otherwise zero is returned after iterating through whole EXP.
1590 */
1591
1592 static int
1593 exp_iterate (struct expression *exp,
1594 int (*objfile_func) (struct objfile *objfile, void *data),
1595 void *data)
1596 {
1597 int endpos;
1598
1599 for (endpos = exp->nelts; endpos > 0; )
1600 {
1601 int pos, args, oplen = 0;
1602
1603 operator_length (exp, endpos, &oplen, &args);
1604 gdb_assert (oplen > 0);
1605
1606 pos = endpos - oplen;
1607 if (exp->language_defn->la_exp_desc->operator_check (exp, pos,
1608 objfile_func, data))
1609 return 1;
1610
1611 endpos = pos;
1612 }
1613
1614 return 0;
1615 }
1616
1617 /* Helper for exp_uses_objfile. */
1618
1619 static int
1620 exp_uses_objfile_iter (struct objfile *exp_objfile, void *objfile_voidp)
1621 {
1622 struct objfile *objfile = objfile_voidp;
1623
1624 if (exp_objfile->separate_debug_objfile_backlink)
1625 exp_objfile = exp_objfile->separate_debug_objfile_backlink;
1626
1627 return exp_objfile == objfile;
1628 }
1629
1630 /* Return 1 if EXP uses OBJFILE (and will become dangling when OBJFILE
1631 is unloaded), otherwise return 0. OBJFILE must not be a separate debug info
1632 file. */
1633
1634 int
1635 exp_uses_objfile (struct expression *exp, struct objfile *objfile)
1636 {
1637 gdb_assert (objfile->separate_debug_objfile_backlink == NULL);
1638
1639 return exp_iterate (exp, exp_uses_objfile_iter, objfile);
1640 }
1641
1642 void
1643 _initialize_parse (void)
1644 {
1645 type_stack_size = 80;
1646 type_stack_depth = 0;
1647 type_stack = (union type_stack_elt *)
1648 xmalloc (type_stack_size * sizeof (*type_stack));
1649
1650 add_setshow_zinteger_cmd ("expression", class_maintenance,
1651 &expressiondebug,
1652 _("Set expression debugging."),
1653 _("Show expression debugging."),
1654 _("When non-zero, the internal representation "
1655 "of expressions will be printed."),
1656 NULL,
1657 show_expressiondebug,
1658 &setdebuglist, &showdebuglist);
1659 add_setshow_boolean_cmd ("parser", class_maintenance,
1660 &parser_debug,
1661 _("Set parser debugging."),
1662 _("Show parser debugging."),
1663 _("When non-zero, expression parser "
1664 "tracing will be enabled."),
1665 NULL,
1666 show_parserdebug,
1667 &setdebuglist, &showdebuglist);
1668 }
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