1 /* Parse expressions for GDB.
3 Copyright (C) 1986-2014 Free Software Foundation, Inc.
5 Modified from expread.y by the Department of Computer Science at the
6 State University of New York at Buffalo, 1991.
8 This file is part of GDB.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 /* Parse an expression from text in a string,
24 and return the result as a struct expression pointer.
25 That structure contains arithmetic operations in reverse polish,
26 with constants represented by operations that are followed by special data.
27 See expression.h for the details of the format.
28 What is important here is that it can be built up sequentially
29 during the process of parsing; the lower levels of the tree always
30 come first in the result. */
34 #include "arch-utils.h"
39 #include "expression.h"
44 #include "parser-defs.h"
46 #include "symfile.h" /* for overlay functions */
52 #include "exceptions.h"
53 #include "user-regs.h"
55 /* Standard set of definitions for printing, dumping, prefixifying,
56 * and evaluating expressions. */
58 const struct exp_descriptor exp_descriptor_standard =
60 print_subexp_standard,
61 operator_length_standard,
62 operator_check_standard,
64 dump_subexp_body_standard,
65 evaluate_subexp_standard
68 /* Global variables declared in parser-defs.h (and commented there). */
69 const struct block *expression_context_block;
70 CORE_ADDR expression_context_pc;
71 const struct block *innermost_block;
73 static struct type_stack type_stack;
75 const char *prev_lexptr;
79 /* True if parsing an expression to attempt completion. */
82 /* The index of the last struct expression directly before a '.' or
83 '->'. This is set when parsing and is only used when completing a
84 field name. It is -1 if no dereference operation was found. */
85 static int expout_last_struct = -1;
87 /* If we are completing a tagged type name, this will be nonzero. */
88 static enum type_code expout_tag_completion_type = TYPE_CODE_UNDEF;
90 /* The token for tagged type name completion. */
91 static char *expout_completion_name;
94 static unsigned int expressiondebug = 0;
96 show_expressiondebug (struct ui_file *file, int from_tty,
97 struct cmd_list_element *c, const char *value)
99 fprintf_filtered (file, _("Expression debugging is %s.\n"), value);
103 /* Non-zero if an expression parser should set yydebug. */
107 show_parserdebug (struct ui_file *file, int from_tty,
108 struct cmd_list_element *c, const char *value)
110 fprintf_filtered (file, _("Parser debugging is %s.\n"), value);
114 static void free_funcalls (void *ignore);
116 static int prefixify_subexp (struct expression *, struct expression *, int,
119 static struct expression *parse_exp_in_context (const char **, CORE_ADDR,
120 const struct block *, int,
122 static struct expression *parse_exp_in_context_1 (const char **, CORE_ADDR,
123 const struct block *, int,
126 void _initialize_parse (void);
128 /* Data structure for saving values of arglist_len for function calls whose
129 arguments contain other function calls. */
133 struct funcall *next;
137 static struct funcall *funcall_chain;
139 /* Begin counting arguments for a function call,
140 saving the data about any containing call. */
147 new = (struct funcall *) xmalloc (sizeof (struct funcall));
148 new->next = funcall_chain;
149 new->arglist_len = arglist_len;
154 /* Return the number of arguments in a function call just terminated,
155 and restore the data for the containing function call. */
160 int val = arglist_len;
161 struct funcall *call = funcall_chain;
163 funcall_chain = call->next;
164 arglist_len = call->arglist_len;
169 /* Free everything in the funcall chain.
170 Used when there is an error inside parsing. */
173 free_funcalls (void *ignore)
175 struct funcall *call, *next;
177 for (call = funcall_chain; call; call = next)
185 /* See definition in parser-defs.h. */
188 initialize_expout (struct parser_state *ps, size_t initial_size,
189 const struct language_defn *lang,
190 struct gdbarch *gdbarch)
192 ps->expout_size = initial_size;
194 ps->expout = xmalloc (sizeof (struct expression)
195 + EXP_ELEM_TO_BYTES (ps->expout_size));
196 ps->expout->language_defn = lang;
197 ps->expout->gdbarch = gdbarch;
200 /* See definition in parser-defs.h. */
203 reallocate_expout (struct parser_state *ps)
205 /* Record the actual number of expression elements, and then
206 reallocate the expression memory so that we free up any
209 ps->expout->nelts = ps->expout_ptr;
210 ps->expout = (struct expression *)
211 xrealloc (ps->expout,
212 sizeof (struct expression)
213 + EXP_ELEM_TO_BYTES (ps->expout_ptr));
216 /* This page contains the functions for adding data to the struct expression
217 being constructed. */
219 /* Add one element to the end of the expression. */
221 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
222 a register through here. */
225 write_exp_elt (struct parser_state *ps, const union exp_element *expelt)
227 if (ps->expout_ptr >= ps->expout_size)
229 ps->expout_size *= 2;
230 ps->expout = (struct expression *)
231 xrealloc (ps->expout, sizeof (struct expression)
232 + EXP_ELEM_TO_BYTES (ps->expout_size));
234 ps->expout->elts[ps->expout_ptr++] = *expelt;
238 write_exp_elt_opcode (struct parser_state *ps, enum exp_opcode expelt)
240 union exp_element tmp;
242 memset (&tmp, 0, sizeof (union exp_element));
244 write_exp_elt (ps, &tmp);
248 write_exp_elt_sym (struct parser_state *ps, struct symbol *expelt)
250 union exp_element tmp;
252 memset (&tmp, 0, sizeof (union exp_element));
254 write_exp_elt (ps, &tmp);
258 write_exp_elt_block (struct parser_state *ps, const struct block *b)
260 union exp_element tmp;
262 memset (&tmp, 0, sizeof (union exp_element));
264 write_exp_elt (ps, &tmp);
268 write_exp_elt_objfile (struct parser_state *ps, struct objfile *objfile)
270 union exp_element tmp;
272 memset (&tmp, 0, sizeof (union exp_element));
273 tmp.objfile = objfile;
274 write_exp_elt (ps, &tmp);
278 write_exp_elt_longcst (struct parser_state *ps, LONGEST expelt)
280 union exp_element tmp;
282 memset (&tmp, 0, sizeof (union exp_element));
283 tmp.longconst = expelt;
284 write_exp_elt (ps, &tmp);
288 write_exp_elt_dblcst (struct parser_state *ps, DOUBLEST expelt)
290 union exp_element tmp;
292 memset (&tmp, 0, sizeof (union exp_element));
293 tmp.doubleconst = expelt;
294 write_exp_elt (ps, &tmp);
298 write_exp_elt_decfloatcst (struct parser_state *ps, gdb_byte expelt[16])
300 union exp_element tmp;
303 for (index = 0; index < 16; index++)
304 tmp.decfloatconst[index] = expelt[index];
306 write_exp_elt (ps, &tmp);
310 write_exp_elt_type (struct parser_state *ps, struct type *expelt)
312 union exp_element tmp;
314 memset (&tmp, 0, sizeof (union exp_element));
316 write_exp_elt (ps, &tmp);
320 write_exp_elt_intern (struct parser_state *ps, struct internalvar *expelt)
322 union exp_element tmp;
324 memset (&tmp, 0, sizeof (union exp_element));
325 tmp.internalvar = expelt;
326 write_exp_elt (ps, &tmp);
329 /* Add a string constant to the end of the expression.
331 String constants are stored by first writing an expression element
332 that contains the length of the string, then stuffing the string
333 constant itself into however many expression elements are needed
334 to hold it, and then writing another expression element that contains
335 the length of the string. I.e. an expression element at each end of
336 the string records the string length, so you can skip over the
337 expression elements containing the actual string bytes from either
338 end of the string. Note that this also allows gdb to handle
339 strings with embedded null bytes, as is required for some languages.
341 Don't be fooled by the fact that the string is null byte terminated,
342 this is strictly for the convenience of debugging gdb itself.
343 Gdb does not depend up the string being null terminated, since the
344 actual length is recorded in expression elements at each end of the
345 string. The null byte is taken into consideration when computing how
346 many expression elements are required to hold the string constant, of
351 write_exp_string (struct parser_state *ps, struct stoken str)
353 int len = str.length;
357 /* Compute the number of expression elements required to hold the string
358 (including a null byte terminator), along with one expression element
359 at each end to record the actual string length (not including the
360 null byte terminator). */
362 lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1);
364 increase_expout_size (ps, lenelt);
366 /* Write the leading length expression element (which advances the current
367 expression element index), then write the string constant followed by a
368 terminating null byte, and then write the trailing length expression
371 write_exp_elt_longcst (ps, (LONGEST) len);
372 strdata = (char *) &ps->expout->elts[ps->expout_ptr];
373 memcpy (strdata, str.ptr, len);
374 *(strdata + len) = '\0';
375 ps->expout_ptr += lenelt - 2;
376 write_exp_elt_longcst (ps, (LONGEST) len);
379 /* Add a vector of string constants to the end of the expression.
381 This adds an OP_STRING operation, but encodes the contents
382 differently from write_exp_string. The language is expected to
383 handle evaluation of this expression itself.
385 After the usual OP_STRING header, TYPE is written into the
386 expression as a long constant. The interpretation of this field is
387 up to the language evaluator.
389 Next, each string in VEC is written. The length is written as a
390 long constant, followed by the contents of the string. */
393 write_exp_string_vector (struct parser_state *ps, int type,
394 struct stoken_vector *vec)
399 /* Compute the size. We compute the size in number of slots to
400 avoid issues with string padding. */
402 for (i = 0; i < vec->len; ++i)
404 /* One slot for the length of this element, plus the number of
405 slots needed for this string. */
406 n_slots += 1 + BYTES_TO_EXP_ELEM (vec->tokens[i].length);
409 /* One more slot for the type of the string. */
412 /* Now compute a phony string length. */
413 len = EXP_ELEM_TO_BYTES (n_slots) - 1;
416 increase_expout_size (ps, n_slots);
418 write_exp_elt_opcode (ps, OP_STRING);
419 write_exp_elt_longcst (ps, len);
420 write_exp_elt_longcst (ps, type);
422 for (i = 0; i < vec->len; ++i)
424 write_exp_elt_longcst (ps, vec->tokens[i].length);
425 memcpy (&ps->expout->elts[ps->expout_ptr], vec->tokens[i].ptr,
426 vec->tokens[i].length);
427 ps->expout_ptr += BYTES_TO_EXP_ELEM (vec->tokens[i].length);
430 write_exp_elt_longcst (ps, len);
431 write_exp_elt_opcode (ps, OP_STRING);
434 /* Add a bitstring constant to the end of the expression.
436 Bitstring constants are stored by first writing an expression element
437 that contains the length of the bitstring (in bits), then stuffing the
438 bitstring constant itself into however many expression elements are
439 needed to hold it, and then writing another expression element that
440 contains the length of the bitstring. I.e. an expression element at
441 each end of the bitstring records the bitstring length, so you can skip
442 over the expression elements containing the actual bitstring bytes from
443 either end of the bitstring. */
446 write_exp_bitstring (struct parser_state *ps, struct stoken str)
448 int bits = str.length; /* length in bits */
449 int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
453 /* Compute the number of expression elements required to hold the bitstring,
454 along with one expression element at each end to record the actual
455 bitstring length in bits. */
457 lenelt = 2 + BYTES_TO_EXP_ELEM (len);
459 increase_expout_size (ps, lenelt);
461 /* Write the leading length expression element (which advances the current
462 expression element index), then write the bitstring constant, and then
463 write the trailing length expression element. */
465 write_exp_elt_longcst (ps, (LONGEST) bits);
466 strdata = (char *) &ps->expout->elts[ps->expout_ptr];
467 memcpy (strdata, str.ptr, len);
468 ps->expout_ptr += lenelt - 2;
469 write_exp_elt_longcst (ps, (LONGEST) bits);
472 /* Add the appropriate elements for a minimal symbol to the end of
476 write_exp_msymbol (struct parser_state *ps,
477 struct bound_minimal_symbol bound_msym)
479 struct minimal_symbol *msymbol = bound_msym.minsym;
480 struct objfile *objfile = bound_msym.objfile;
481 struct gdbarch *gdbarch = get_objfile_arch (objfile);
483 CORE_ADDR addr = BMSYMBOL_VALUE_ADDRESS (bound_msym);
484 struct obj_section *section = MSYMBOL_OBJ_SECTION (objfile, msymbol);
485 enum minimal_symbol_type type = MSYMBOL_TYPE (msymbol);
488 /* The minimal symbol might point to a function descriptor;
489 resolve it to the actual code address instead. */
490 pc = gdbarch_convert_from_func_ptr_addr (gdbarch, addr, ¤t_target);
493 struct bound_minimal_symbol ifunc_msym = lookup_minimal_symbol_by_pc (pc);
495 /* In this case, assume we have a code symbol instead of
498 if (ifunc_msym.minsym != NULL
499 && MSYMBOL_TYPE (ifunc_msym.minsym) == mst_text_gnu_ifunc
500 && BMSYMBOL_VALUE_ADDRESS (ifunc_msym) == pc)
502 /* A function descriptor has been resolved but PC is still in the
503 STT_GNU_IFUNC resolver body (such as because inferior does not
504 run to be able to call it). */
506 type = mst_text_gnu_ifunc;
514 if (overlay_debugging)
515 addr = symbol_overlayed_address (addr, section);
517 write_exp_elt_opcode (ps, OP_LONG);
518 /* Let's make the type big enough to hold a 64-bit address. */
519 write_exp_elt_type (ps, objfile_type (objfile)->builtin_core_addr);
520 write_exp_elt_longcst (ps, (LONGEST) addr);
521 write_exp_elt_opcode (ps, OP_LONG);
523 if (section && section->the_bfd_section->flags & SEC_THREAD_LOCAL)
525 write_exp_elt_opcode (ps, UNOP_MEMVAL_TLS);
526 write_exp_elt_objfile (ps, objfile);
527 write_exp_elt_type (ps, objfile_type (objfile)->nodebug_tls_symbol);
528 write_exp_elt_opcode (ps, UNOP_MEMVAL_TLS);
532 write_exp_elt_opcode (ps, UNOP_MEMVAL);
537 case mst_solib_trampoline:
538 write_exp_elt_type (ps, objfile_type (objfile)->nodebug_text_symbol);
541 case mst_text_gnu_ifunc:
542 write_exp_elt_type (ps, objfile_type (objfile)
543 ->nodebug_text_gnu_ifunc_symbol);
550 write_exp_elt_type (ps, objfile_type (objfile)->nodebug_data_symbol);
553 case mst_slot_got_plt:
554 write_exp_elt_type (ps, objfile_type (objfile)->nodebug_got_plt_symbol);
558 write_exp_elt_type (ps, objfile_type (objfile)->nodebug_unknown_symbol);
561 write_exp_elt_opcode (ps, UNOP_MEMVAL);
564 /* Mark the current index as the starting location of a structure
565 expression. This is used when completing on field names. */
568 mark_struct_expression (struct parser_state *ps)
570 gdb_assert (parse_completion
571 && expout_tag_completion_type == TYPE_CODE_UNDEF);
572 expout_last_struct = ps->expout_ptr;
575 /* Indicate that the current parser invocation is completing a tag.
576 TAG is the type code of the tag, and PTR and LENGTH represent the
577 start of the tag name. */
580 mark_completion_tag (enum type_code tag, const char *ptr, int length)
582 gdb_assert (parse_completion
583 && expout_tag_completion_type == TYPE_CODE_UNDEF
584 && expout_completion_name == NULL
585 && expout_last_struct == -1);
586 gdb_assert (tag == TYPE_CODE_UNION
587 || tag == TYPE_CODE_STRUCT
588 || tag == TYPE_CODE_CLASS
589 || tag == TYPE_CODE_ENUM);
590 expout_tag_completion_type = tag;
591 expout_completion_name = xmalloc (length + 1);
592 memcpy (expout_completion_name, ptr, length);
593 expout_completion_name[length] = '\0';
597 /* Recognize tokens that start with '$'. These include:
599 $regname A native register name or a "standard
602 $variable A convenience variable with a name chosen
605 $digits Value history with index <digits>, starting
606 from the first value which has index 1.
608 $$digits Value history with index <digits> relative
609 to the last value. I.e. $$0 is the last
610 value, $$1 is the one previous to that, $$2
611 is the one previous to $$1, etc.
613 $ | $0 | $$0 The last value in the value history.
615 $$ An abbreviation for the second to the last
616 value in the value history, I.e. $$1 */
619 write_dollar_variable (struct parser_state *ps, struct stoken str)
621 struct symbol *sym = NULL;
622 struct bound_minimal_symbol msym;
623 struct internalvar *isym = NULL;
625 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
626 and $$digits (equivalent to $<-digits> if you could type that). */
630 /* Double dollar means negate the number and add -1 as well.
631 Thus $$ alone means -1. */
632 if (str.length >= 2 && str.ptr[1] == '$')
639 /* Just dollars (one or two). */
643 /* Is the rest of the token digits? */
644 for (; i < str.length; i++)
645 if (!(str.ptr[i] >= '0' && str.ptr[i] <= '9'))
649 i = atoi (str.ptr + 1 + negate);
655 /* Handle tokens that refer to machine registers:
656 $ followed by a register name. */
657 i = user_reg_map_name_to_regnum (parse_gdbarch (ps),
658 str.ptr + 1, str.length - 1);
660 goto handle_register;
662 /* Any names starting with $ are probably debugger internal variables. */
664 isym = lookup_only_internalvar (copy_name (str) + 1);
667 write_exp_elt_opcode (ps, OP_INTERNALVAR);
668 write_exp_elt_intern (ps, isym);
669 write_exp_elt_opcode (ps, OP_INTERNALVAR);
673 /* On some systems, such as HP-UX and hppa-linux, certain system routines
674 have names beginning with $ or $$. Check for those, first. */
676 sym = lookup_symbol (copy_name (str), (struct block *) NULL,
680 write_exp_elt_opcode (ps, OP_VAR_VALUE);
681 write_exp_elt_block (ps, block_found); /* set by lookup_symbol */
682 write_exp_elt_sym (ps, sym);
683 write_exp_elt_opcode (ps, OP_VAR_VALUE);
686 msym = lookup_bound_minimal_symbol (copy_name (str));
689 write_exp_msymbol (ps, msym);
693 /* Any other names are assumed to be debugger internal variables. */
695 write_exp_elt_opcode (ps, OP_INTERNALVAR);
696 write_exp_elt_intern (ps, create_internalvar (copy_name (str) + 1));
697 write_exp_elt_opcode (ps, OP_INTERNALVAR);
700 write_exp_elt_opcode (ps, OP_LAST);
701 write_exp_elt_longcst (ps, (LONGEST) i);
702 write_exp_elt_opcode (ps, OP_LAST);
705 write_exp_elt_opcode (ps, OP_REGISTER);
708 write_exp_string (ps, str);
709 write_exp_elt_opcode (ps, OP_REGISTER);
715 find_template_name_end (const char *p)
718 int just_seen_right = 0;
719 int just_seen_colon = 0;
720 int just_seen_space = 0;
722 if (!p || (*p != '<'))
733 /* In future, may want to allow these?? */
736 depth++; /* start nested template */
737 if (just_seen_colon || just_seen_right || just_seen_space)
738 return 0; /* but not after : or :: or > or space */
741 if (just_seen_colon || just_seen_right)
742 return 0; /* end a (nested?) template */
743 just_seen_right = 1; /* but not after : or :: */
744 if (--depth == 0) /* also disallow >>, insist on > > */
745 return ++p; /* if outermost ended, return */
748 if (just_seen_space || (just_seen_colon > 1))
749 return 0; /* nested class spec coming up */
750 just_seen_colon++; /* we allow :: but not :::: */
755 if (!((*p >= 'a' && *p <= 'z') || /* allow token chars */
756 (*p >= 'A' && *p <= 'Z') ||
757 (*p >= '0' && *p <= '9') ||
758 (*p == '_') || (*p == ',') || /* commas for template args */
759 (*p == '&') || (*p == '*') || /* pointer and ref types */
760 (*p == '(') || (*p == ')') || /* function types */
761 (*p == '[') || (*p == ']'))) /* array types */
775 /* Return a null-terminated temporary copy of the name of a string token.
777 Tokens that refer to names do so with explicit pointer and length,
778 so they can share the storage that lexptr is parsing.
779 When it is necessary to pass a name to a function that expects
780 a null-terminated string, the substring is copied out
781 into a separate block of storage.
783 N.B. A single buffer is reused on each call. */
786 copy_name (struct stoken token)
788 /* A temporary buffer for identifiers, so we can null-terminate them.
789 We allocate this with xrealloc. parse_exp_1 used to allocate with
790 alloca, using the size of the whole expression as a conservative
791 estimate of the space needed. However, macro expansion can
792 introduce names longer than the original expression; there's no
793 practical way to know beforehand how large that might be. */
794 static char *namecopy;
795 static size_t namecopy_size;
797 /* Make sure there's enough space for the token. */
798 if (namecopy_size < token.length + 1)
800 namecopy_size = token.length + 1;
801 namecopy = xrealloc (namecopy, token.length + 1);
804 memcpy (namecopy, token.ptr, token.length);
805 namecopy[token.length] = 0;
811 /* See comments on parser-defs.h. */
814 prefixify_expression (struct expression *expr)
816 int len = sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts);
817 struct expression *temp;
818 int inpos = expr->nelts, outpos = 0;
820 temp = (struct expression *) alloca (len);
822 /* Copy the original expression into temp. */
823 memcpy (temp, expr, len);
825 return prefixify_subexp (temp, expr, inpos, outpos);
828 /* Return the number of exp_elements in the postfix subexpression
829 of EXPR whose operator is at index ENDPOS - 1 in EXPR. */
832 length_of_subexp (struct expression *expr, int endpos)
836 operator_length (expr, endpos, &oplen, &args);
840 oplen += length_of_subexp (expr, endpos - oplen);
847 /* Sets *OPLENP to the length of the operator whose (last) index is
848 ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
852 operator_length (const struct expression *expr, int endpos, int *oplenp,
855 expr->language_defn->la_exp_desc->operator_length (expr, endpos,
859 /* Default value for operator_length in exp_descriptor vectors. */
862 operator_length_standard (const struct expression *expr, int endpos,
863 int *oplenp, int *argsp)
867 enum f90_range_type range_type;
871 error (_("?error in operator_length_standard"));
873 i = (int) expr->elts[endpos - 1].opcode;
879 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
880 oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1);
894 case OP_VAR_ENTRY_VALUE:
904 case OP_F77_UNDETERMINED_ARGLIST:
906 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
910 oplen = 4 + longest_to_int (expr->elts[endpos - 2].longconst);
914 case OP_OBJC_MSGCALL: /* Objective C message (method) call. */
916 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
925 case UNOP_DYNAMIC_CAST:
926 case UNOP_REINTERPRET_CAST:
927 case UNOP_MEMVAL_TYPE:
939 case UNOP_MEMVAL_TLS:
960 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
961 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
966 case STRUCTOP_STRUCT:
973 case OP_OBJC_NSSTRING: /* Objective C Foundation Class
974 NSString constant. */
975 case OP_OBJC_SELECTOR: /* Objective C "@selector" pseudo-op. */
977 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
978 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
983 args = longest_to_int (expr->elts[endpos - 2].longconst);
984 args -= longest_to_int (expr->elts[endpos - 3].longconst);
994 case MULTI_SUBSCRIPT:
996 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
999 case BINOP_ASSIGN_MODIFY:
1012 range_type = longest_to_int (expr->elts[endpos - 2].longconst);
1015 case LOW_BOUND_DEFAULT:
1016 case HIGH_BOUND_DEFAULT:
1019 case BOTH_BOUND_DEFAULT:
1022 case NONE_BOUND_DEFAULT:
1030 args = 1 + (i < (int) BINOP_END);
1037 /* Copy the subexpression ending just before index INEND in INEXPR
1038 into OUTEXPR, starting at index OUTBEG.
1039 In the process, convert it from suffix to prefix form.
1040 If EXPOUT_LAST_STRUCT is -1, then this function always returns -1.
1041 Otherwise, it returns the index of the subexpression which is the
1042 left-hand-side of the expression at EXPOUT_LAST_STRUCT. */
1045 prefixify_subexp (struct expression *inexpr,
1046 struct expression *outexpr, int inend, int outbeg)
1054 operator_length (inexpr, inend, &oplen, &args);
1056 /* Copy the final operator itself, from the end of the input
1057 to the beginning of the output. */
1059 memcpy (&outexpr->elts[outbeg], &inexpr->elts[inend],
1060 EXP_ELEM_TO_BYTES (oplen));
1063 if (expout_last_struct == inend)
1064 result = outbeg - oplen;
1066 /* Find the lengths of the arg subexpressions. */
1067 arglens = (int *) alloca (args * sizeof (int));
1068 for (i = args - 1; i >= 0; i--)
1070 oplen = length_of_subexp (inexpr, inend);
1075 /* Now copy each subexpression, preserving the order of
1076 the subexpressions, but prefixifying each one.
1077 In this loop, inend starts at the beginning of
1078 the expression this level is working on
1079 and marches forward over the arguments.
1080 outbeg does similarly in the output. */
1081 for (i = 0; i < args; i++)
1087 r = prefixify_subexp (inexpr, outexpr, inend, outbeg);
1090 /* Return immediately. We probably have only parsed a
1091 partial expression, so we don't want to try to reverse
1092 the other operands. */
1101 /* Read an expression from the string *STRINGPTR points to,
1102 parse it, and return a pointer to a struct expression that we malloc.
1103 Use block BLOCK as the lexical context for variable names;
1104 if BLOCK is zero, use the block of the selected stack frame.
1105 Meanwhile, advance *STRINGPTR to point after the expression,
1106 at the first nonwhite character that is not part of the expression
1107 (possibly a null character).
1109 If COMMA is nonzero, stop if a comma is reached. */
1112 parse_exp_1 (const char **stringptr, CORE_ADDR pc, const struct block *block,
1115 return parse_exp_in_context (stringptr, pc, block, comma, 0, NULL);
1118 static struct expression *
1119 parse_exp_in_context (const char **stringptr, CORE_ADDR pc,
1120 const struct block *block,
1121 int comma, int void_context_p, int *out_subexp)
1123 return parse_exp_in_context_1 (stringptr, pc, block, comma,
1124 void_context_p, out_subexp);
1127 /* As for parse_exp_1, except that if VOID_CONTEXT_P, then
1128 no value is expected from the expression.
1129 OUT_SUBEXP is set when attempting to complete a field name; in this
1130 case it is set to the index of the subexpression on the
1131 left-hand-side of the struct op. If not doing such completion, it
1132 is left untouched. */
1134 static struct expression *
1135 parse_exp_in_context_1 (const char **stringptr, CORE_ADDR pc,
1136 const struct block *block,
1137 int comma, int void_context_p, int *out_subexp)
1139 volatile struct gdb_exception except;
1140 struct cleanup *old_chain, *inner_chain;
1141 const struct language_defn *lang = NULL;
1142 struct parser_state ps;
1145 lexptr = *stringptr;
1149 type_stack.depth = 0;
1150 expout_last_struct = -1;
1151 expout_tag_completion_type = TYPE_CODE_UNDEF;
1152 xfree (expout_completion_name);
1153 expout_completion_name = NULL;
1155 comma_terminates = comma;
1157 if (lexptr == 0 || *lexptr == 0)
1158 error_no_arg (_("expression to compute"));
1160 old_chain = make_cleanup (free_funcalls, 0 /*ignore*/);
1163 expression_context_block = block;
1165 /* If no context specified, try using the current frame, if any. */
1166 if (!expression_context_block)
1167 expression_context_block = get_selected_block (&expression_context_pc);
1169 expression_context_pc = BLOCK_START (expression_context_block);
1171 expression_context_pc = pc;
1173 /* Fall back to using the current source static context, if any. */
1175 if (!expression_context_block)
1177 struct symtab_and_line cursal = get_current_source_symtab_and_line ();
1179 expression_context_block
1180 = BLOCKVECTOR_BLOCK (BLOCKVECTOR (cursal.symtab), STATIC_BLOCK);
1181 if (expression_context_block)
1182 expression_context_pc = BLOCK_START (expression_context_block);
1185 if (language_mode == language_mode_auto && block != NULL)
1187 /* Find the language associated to the given context block.
1188 Default to the current language if it can not be determined.
1190 Note that using the language corresponding to the current frame
1191 can sometimes give unexpected results. For instance, this
1192 routine is often called several times during the inferior
1193 startup phase to re-parse breakpoint expressions after
1194 a new shared library has been loaded. The language associated
1195 to the current frame at this moment is not relevant for
1196 the breakpoint. Using it would therefore be silly, so it seems
1197 better to rely on the current language rather than relying on
1198 the current frame language to parse the expression. That's why
1199 we do the following language detection only if the context block
1200 has been specifically provided. */
1201 struct symbol *func = block_linkage_function (block);
1204 lang = language_def (SYMBOL_LANGUAGE (func));
1205 if (lang == NULL || lang->la_language == language_unknown)
1206 lang = current_language;
1209 lang = current_language;
1211 /* get_current_arch may reset CURRENT_LANGUAGE via select_frame.
1212 While we need CURRENT_LANGUAGE to be set to LANG (for lookup_symbol
1213 and others called from *.y) ensure CURRENT_LANGUAGE gets restored
1214 to the value matching SELECTED_FRAME as set by get_current_arch. */
1216 initialize_expout (&ps, 10, lang, get_current_arch ());
1217 inner_chain = make_cleanup_restore_current_language ();
1218 set_language (lang->la_language);
1220 TRY_CATCH (except, RETURN_MASK_ALL)
1222 if (lang->la_parser (&ps))
1223 lang->la_error (NULL);
1225 if (except.reason < 0)
1227 if (! parse_completion)
1230 throw_exception (except);
1234 reallocate_expout (&ps);
1236 /* Convert expression from postfix form as generated by yacc
1237 parser, to a prefix form. */
1239 if (expressiondebug)
1240 dump_raw_expression (ps.expout, gdb_stdlog,
1241 "before conversion to prefix form");
1243 subexp = prefixify_expression (ps.expout);
1245 *out_subexp = subexp;
1247 lang->la_post_parser (&ps.expout, void_context_p);
1249 if (expressiondebug)
1250 dump_prefix_expression (ps.expout, gdb_stdlog);
1252 do_cleanups (inner_chain);
1253 discard_cleanups (old_chain);
1255 *stringptr = lexptr;
1259 /* Parse STRING as an expression, and complain if this fails
1260 to use up all of the contents of STRING. */
1263 parse_expression (const char *string)
1265 struct expression *exp;
1267 exp = parse_exp_1 (&string, 0, 0, 0);
1269 error (_("Junk after end of expression."));
1273 /* Parse STRING as an expression. If parsing ends in the middle of a
1274 field reference, return the type of the left-hand-side of the
1275 reference; furthermore, if the parsing ends in the field name,
1276 return the field name in *NAME. If the parsing ends in the middle
1277 of a field reference, but the reference is somehow invalid, throw
1278 an exception. In all other cases, return NULL. Returned non-NULL
1279 *NAME must be freed by the caller. */
1282 parse_expression_for_completion (const char *string, char **name,
1283 enum type_code *code)
1285 struct expression *exp = NULL;
1288 volatile struct gdb_exception except;
1290 TRY_CATCH (except, RETURN_MASK_ERROR)
1292 parse_completion = 1;
1293 exp = parse_exp_in_context (&string, 0, 0, 0, 0, &subexp);
1295 parse_completion = 0;
1296 if (except.reason < 0 || ! exp)
1299 if (expout_tag_completion_type != TYPE_CODE_UNDEF)
1301 *code = expout_tag_completion_type;
1302 *name = expout_completion_name;
1303 expout_completion_name = NULL;
1307 if (expout_last_struct == -1)
1313 *name = extract_field_op (exp, &subexp);
1320 /* This might throw an exception. If so, we want to let it
1322 val = evaluate_subexpression_type (exp, subexp);
1323 /* (*NAME) is a part of the EXP memory block freed below. */
1324 *name = xstrdup (*name);
1327 return value_type (val);
1330 /* A post-parser that does nothing. */
1333 null_post_parser (struct expression **exp, int void_context_p)
1337 /* Parse floating point value P of length LEN.
1338 Return 0 (false) if invalid, 1 (true) if valid.
1339 The successfully parsed number is stored in D.
1340 *SUFFIX points to the suffix of the number in P.
1342 NOTE: This accepts the floating point syntax that sscanf accepts. */
1345 parse_float (const char *p, int len, DOUBLEST *d, const char **suffix)
1350 copy = xmalloc (len + 1);
1351 memcpy (copy, p, len);
1354 num = sscanf (copy, "%" DOUBLEST_SCAN_FORMAT "%n", d, &n);
1357 /* The sscanf man page suggests not making any assumptions on the effect
1358 of %n on the result, so we don't.
1359 That is why we simply test num == 0. */
1367 /* Parse floating point value P of length LEN, using the C syntax for floats.
1368 Return 0 (false) if invalid, 1 (true) if valid.
1369 The successfully parsed number is stored in *D.
1370 Its type is taken from builtin_type (gdbarch) and is stored in *T. */
1373 parse_c_float (struct gdbarch *gdbarch, const char *p, int len,
1374 DOUBLEST *d, struct type **t)
1378 const struct builtin_type *builtin_types = builtin_type (gdbarch);
1380 if (! parse_float (p, len, d, &suffix))
1383 suffix_len = p + len - suffix;
1385 if (suffix_len == 0)
1386 *t = builtin_types->builtin_double;
1387 else if (suffix_len == 1)
1389 /* Handle suffixes: 'f' for float, 'l' for long double. */
1390 if (tolower (*suffix) == 'f')
1391 *t = builtin_types->builtin_float;
1392 else if (tolower (*suffix) == 'l')
1393 *t = builtin_types->builtin_long_double;
1403 /* Stuff for maintaining a stack of types. Currently just used by C, but
1404 probably useful for any language which declares its types "backwards". */
1406 /* Ensure that there are HOWMUCH open slots on the type stack STACK. */
1409 type_stack_reserve (struct type_stack *stack, int howmuch)
1411 if (stack->depth + howmuch >= stack->size)
1414 if (stack->size < howmuch)
1415 stack->size = howmuch;
1416 stack->elements = xrealloc (stack->elements,
1417 stack->size * sizeof (union type_stack_elt));
1421 /* Ensure that there is a single open slot in the global type stack. */
1424 check_type_stack_depth (void)
1426 type_stack_reserve (&type_stack, 1);
1429 /* A helper function for insert_type and insert_type_address_space.
1430 This does work of expanding the type stack and inserting the new
1431 element, ELEMENT, into the stack at location SLOT. */
1434 insert_into_type_stack (int slot, union type_stack_elt element)
1436 check_type_stack_depth ();
1438 if (slot < type_stack.depth)
1439 memmove (&type_stack.elements[slot + 1], &type_stack.elements[slot],
1440 (type_stack.depth - slot) * sizeof (union type_stack_elt));
1441 type_stack.elements[slot] = element;
1445 /* Insert a new type, TP, at the bottom of the type stack. If TP is
1446 tp_pointer or tp_reference, it is inserted at the bottom. If TP is
1447 a qualifier, it is inserted at slot 1 (just above a previous
1448 tp_pointer) if there is anything on the stack, or simply pushed if
1449 the stack is empty. Other values for TP are invalid. */
1452 insert_type (enum type_pieces tp)
1454 union type_stack_elt element;
1457 gdb_assert (tp == tp_pointer || tp == tp_reference
1458 || tp == tp_const || tp == tp_volatile);
1460 /* If there is anything on the stack (we know it will be a
1461 tp_pointer), insert the qualifier above it. Otherwise, simply
1462 push this on the top of the stack. */
1463 if (type_stack.depth && (tp == tp_const || tp == tp_volatile))
1469 insert_into_type_stack (slot, element);
1473 push_type (enum type_pieces tp)
1475 check_type_stack_depth ();
1476 type_stack.elements[type_stack.depth++].piece = tp;
1480 push_type_int (int n)
1482 check_type_stack_depth ();
1483 type_stack.elements[type_stack.depth++].int_val = n;
1486 /* Insert a tp_space_identifier and the corresponding address space
1487 value into the stack. STRING is the name of an address space, as
1488 recognized by address_space_name_to_int. If the stack is empty,
1489 the new elements are simply pushed. If the stack is not empty,
1490 this function assumes that the first item on the stack is a
1491 tp_pointer, and the new values are inserted above the first
1495 insert_type_address_space (struct parser_state *pstate, char *string)
1497 union type_stack_elt element;
1500 /* If there is anything on the stack (we know it will be a
1501 tp_pointer), insert the address space qualifier above it.
1502 Otherwise, simply push this on the top of the stack. */
1503 if (type_stack.depth)
1508 element.piece = tp_space_identifier;
1509 insert_into_type_stack (slot, element);
1510 element.int_val = address_space_name_to_int (parse_gdbarch (pstate),
1512 insert_into_type_stack (slot, element);
1518 if (type_stack.depth)
1519 return type_stack.elements[--type_stack.depth].piece;
1526 if (type_stack.depth)
1527 return type_stack.elements[--type_stack.depth].int_val;
1528 /* "Can't happen". */
1532 /* Pop a type list element from the global type stack. */
1534 static VEC (type_ptr) *
1537 gdb_assert (type_stack.depth);
1538 return type_stack.elements[--type_stack.depth].typelist_val;
1541 /* Pop a type_stack element from the global type stack. */
1543 static struct type_stack *
1544 pop_type_stack (void)
1546 gdb_assert (type_stack.depth);
1547 return type_stack.elements[--type_stack.depth].stack_val;
1550 /* Append the elements of the type stack FROM to the type stack TO.
1551 Always returns TO. */
1554 append_type_stack (struct type_stack *to, struct type_stack *from)
1556 type_stack_reserve (to, from->depth);
1558 memcpy (&to->elements[to->depth], &from->elements[0],
1559 from->depth * sizeof (union type_stack_elt));
1560 to->depth += from->depth;
1565 /* Push the type stack STACK as an element on the global type stack. */
1568 push_type_stack (struct type_stack *stack)
1570 check_type_stack_depth ();
1571 type_stack.elements[type_stack.depth++].stack_val = stack;
1572 push_type (tp_type_stack);
1575 /* Copy the global type stack into a newly allocated type stack and
1576 return it. The global stack is cleared. The returned type stack
1577 must be freed with type_stack_cleanup. */
1580 get_type_stack (void)
1582 struct type_stack *result = XNEW (struct type_stack);
1584 *result = type_stack;
1585 type_stack.depth = 0;
1586 type_stack.size = 0;
1587 type_stack.elements = NULL;
1592 /* A cleanup function that destroys a single type stack. */
1595 type_stack_cleanup (void *arg)
1597 struct type_stack *stack = arg;
1599 xfree (stack->elements);
1603 /* Push a function type with arguments onto the global type stack.
1604 LIST holds the argument types. If the final item in LIST is NULL,
1605 then the function will be varargs. */
1608 push_typelist (VEC (type_ptr) *list)
1610 check_type_stack_depth ();
1611 type_stack.elements[type_stack.depth++].typelist_val = list;
1612 push_type (tp_function_with_arguments);
1615 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1616 as modified by all the stuff on the stack. */
1618 follow_types (struct type *follow_type)
1622 int make_volatile = 0;
1623 int make_addr_space = 0;
1627 switch (pop_type ())
1632 follow_type = make_cv_type (make_const,
1633 TYPE_VOLATILE (follow_type),
1636 follow_type = make_cv_type (TYPE_CONST (follow_type),
1639 if (make_addr_space)
1640 follow_type = make_type_with_address_space (follow_type,
1642 make_const = make_volatile = 0;
1643 make_addr_space = 0;
1651 case tp_space_identifier:
1652 make_addr_space = pop_type_int ();
1655 follow_type = lookup_pointer_type (follow_type);
1657 follow_type = make_cv_type (make_const,
1658 TYPE_VOLATILE (follow_type),
1661 follow_type = make_cv_type (TYPE_CONST (follow_type),
1664 if (make_addr_space)
1665 follow_type = make_type_with_address_space (follow_type,
1667 make_const = make_volatile = 0;
1668 make_addr_space = 0;
1671 follow_type = lookup_reference_type (follow_type);
1673 follow_type = make_cv_type (make_const,
1674 TYPE_VOLATILE (follow_type),
1677 follow_type = make_cv_type (TYPE_CONST (follow_type),
1680 if (make_addr_space)
1681 follow_type = make_type_with_address_space (follow_type,
1683 make_const = make_volatile = 0;
1684 make_addr_space = 0;
1687 array_size = pop_type_int ();
1688 /* FIXME-type-allocation: need a way to free this type when we are
1691 lookup_array_range_type (follow_type,
1692 0, array_size >= 0 ? array_size - 1 : 0);
1694 TYPE_HIGH_BOUND_KIND (TYPE_INDEX_TYPE (follow_type))
1698 /* FIXME-type-allocation: need a way to free this type when we are
1700 follow_type = lookup_function_type (follow_type);
1703 case tp_function_with_arguments:
1705 VEC (type_ptr) *args = pop_typelist ();
1708 = lookup_function_type_with_arguments (follow_type,
1709 VEC_length (type_ptr, args),
1710 VEC_address (type_ptr,
1712 VEC_free (type_ptr, args);
1718 struct type_stack *stack = pop_type_stack ();
1719 /* Sort of ugly, but not really much worse than the
1721 struct type_stack save = type_stack;
1723 type_stack = *stack;
1724 follow_type = follow_types (follow_type);
1725 gdb_assert (type_stack.depth == 0);
1731 gdb_assert_not_reached ("unrecognized tp_ value in follow_types");
1736 /* This function avoids direct calls to fprintf
1737 in the parser generated debug code. */
1739 parser_fprintf (FILE *x, const char *y, ...)
1745 vfprintf_unfiltered (gdb_stderr, y, args);
1748 fprintf_unfiltered (gdb_stderr, " Unknown FILE used.\n");
1749 vfprintf_unfiltered (gdb_stderr, y, args);
1754 /* Implementation of the exp_descriptor method operator_check. */
1757 operator_check_standard (struct expression *exp, int pos,
1758 int (*objfile_func) (struct objfile *objfile,
1762 const union exp_element *const elts = exp->elts;
1763 struct type *type = NULL;
1764 struct objfile *objfile = NULL;
1766 /* Extended operators should have been already handled by exp_descriptor
1767 iterate method of its specific language. */
1768 gdb_assert (elts[pos].opcode < OP_EXTENDED0);
1770 /* Track the callers of write_exp_elt_type for this table. */
1772 switch (elts[pos].opcode)
1785 type = elts[pos + 1].type;
1790 LONGEST arg, nargs = elts[pos + 1].longconst;
1792 for (arg = 0; arg < nargs; arg++)
1794 struct type *type = elts[pos + 2 + arg].type;
1795 struct objfile *objfile = TYPE_OBJFILE (type);
1797 if (objfile && (*objfile_func) (objfile, data))
1803 case UNOP_MEMVAL_TLS:
1804 objfile = elts[pos + 1].objfile;
1805 type = elts[pos + 2].type;
1810 const struct block *const block = elts[pos + 1].block;
1811 const struct symbol *const symbol = elts[pos + 2].symbol;
1813 /* Check objfile where the variable itself is placed.
1814 SYMBOL_OBJ_SECTION (symbol) may be NULL. */
1815 if ((*objfile_func) (SYMBOL_SYMTAB (symbol)->objfile, data))
1818 /* Check objfile where is placed the code touching the variable. */
1819 objfile = lookup_objfile_from_block (block);
1821 type = SYMBOL_TYPE (symbol);
1826 /* Invoke callbacks for TYPE and OBJFILE if they were set as non-NULL. */
1828 if (type && TYPE_OBJFILE (type)
1829 && (*objfile_func) (TYPE_OBJFILE (type), data))
1831 if (objfile && (*objfile_func) (objfile, data))
1837 /* Call OBJFILE_FUNC for any objfile found being referenced by EXP.
1838 OBJFILE_FUNC is never called with NULL OBJFILE. OBJFILE_FUNC get
1839 passed an arbitrary caller supplied DATA pointer. If OBJFILE_FUNC
1840 returns non-zero value then (any other) non-zero value is immediately
1841 returned to the caller. Otherwise zero is returned after iterating
1842 through whole EXP. */
1845 exp_iterate (struct expression *exp,
1846 int (*objfile_func) (struct objfile *objfile, void *data),
1851 for (endpos = exp->nelts; endpos > 0; )
1853 int pos, args, oplen = 0;
1855 operator_length (exp, endpos, &oplen, &args);
1856 gdb_assert (oplen > 0);
1858 pos = endpos - oplen;
1859 if (exp->language_defn->la_exp_desc->operator_check (exp, pos,
1860 objfile_func, data))
1869 /* Helper for exp_uses_objfile. */
1872 exp_uses_objfile_iter (struct objfile *exp_objfile, void *objfile_voidp)
1874 struct objfile *objfile = objfile_voidp;
1876 if (exp_objfile->separate_debug_objfile_backlink)
1877 exp_objfile = exp_objfile->separate_debug_objfile_backlink;
1879 return exp_objfile == objfile;
1882 /* Return 1 if EXP uses OBJFILE (and will become dangling when OBJFILE
1883 is unloaded), otherwise return 0. OBJFILE must not be a separate debug info
1887 exp_uses_objfile (struct expression *exp, struct objfile *objfile)
1889 gdb_assert (objfile->separate_debug_objfile_backlink == NULL);
1891 return exp_iterate (exp, exp_uses_objfile_iter, objfile);
1894 /* See definition in parser-defs.h. */
1897 increase_expout_size (struct parser_state *ps, size_t lenelt)
1899 if ((ps->expout_ptr + lenelt) >= ps->expout_size)
1901 ps->expout_size = max (ps->expout_size * 2,
1902 ps->expout_ptr + lenelt + 10);
1903 ps->expout = (struct expression *)
1904 xrealloc (ps->expout, (sizeof (struct expression)
1905 + EXP_ELEM_TO_BYTES (ps->expout_size)));
1910 _initialize_parse (void)
1912 type_stack.size = 0;
1913 type_stack.depth = 0;
1914 type_stack.elements = NULL;
1916 add_setshow_zuinteger_cmd ("expression", class_maintenance,
1918 _("Set expression debugging."),
1919 _("Show expression debugging."),
1920 _("When non-zero, the internal representation "
1921 "of expressions will be printed."),
1923 show_expressiondebug,
1924 &setdebuglist, &showdebuglist);
1925 add_setshow_boolean_cmd ("parser", class_maintenance,
1927 _("Set parser debugging."),
1928 _("Show parser debugging."),
1929 _("When non-zero, expression parser "
1930 "tracing will be enabled."),
1933 &setdebuglist, &showdebuglist);