1 /* Parse expressions for GDB.
3 Copyright (C) 1986-2019 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"
38 #include "expression.h"
43 #include "parser-defs.h"
45 #include "symfile.h" /* for overlay functions */
47 #include "target-float.h"
51 #include "user-regs.h"
53 #include "common/gdb_optional.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 innermost_block_tracker 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 gdb::unique_xmalloc_ptr<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 int prefixify_subexp (struct expression *, struct expression *, int,
117 static expression_up parse_exp_in_context (const char **, CORE_ADDR,
118 const struct block *, int,
120 innermost_block_tracker_types);
122 static void increase_expout_size (struct parser_state *ps, size_t lenelt);
125 /* Documented at it's declaration. */
128 innermost_block_tracker::update (const struct block *b,
129 innermost_block_tracker_types t)
131 if ((m_types & t) != 0
132 && (m_innermost_block == NULL
133 || contained_in (b, m_innermost_block)))
134 m_innermost_block = b;
137 /* Data structure for saving values of arglist_len for function calls whose
138 arguments contain other function calls. */
140 static std::vector<int> *funcall_chain;
142 /* Begin counting arguments for a function call,
143 saving the data about any containing call. */
148 funcall_chain->push_back (arglist_len);
152 /* Return the number of arguments in a function call just terminated,
153 and restore the data for the containing function call. */
158 int val = arglist_len;
159 arglist_len = funcall_chain->back ();
160 funcall_chain->pop_back ();
166 /* See definition in parser-defs.h. */
168 parser_state::parser_state (size_t initial_size,
169 const struct language_defn *lang,
170 struct gdbarch *gdbarch)
171 : expout_size (initial_size),
172 expout (XNEWVAR (expression,
174 + EXP_ELEM_TO_BYTES (expout_size)))),
177 expout->language_defn = lang;
178 expout->gdbarch = gdbarch;
182 parser_state::release ()
184 /* Record the actual number of expression elements, and then
185 reallocate the expression memory so that we free up any
188 expout->nelts = expout_ptr;
189 expout.reset (XRESIZEVAR (expression, expout.release (),
191 + EXP_ELEM_TO_BYTES (expout_ptr))));
193 return std::move (expout);
196 /* This page contains the functions for adding data to the struct expression
197 being constructed. */
199 /* Add one element to the end of the expression. */
201 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
202 a register through here. */
205 write_exp_elt (struct parser_state *ps, const union exp_element *expelt)
207 if (ps->expout_ptr >= ps->expout_size)
209 ps->expout_size *= 2;
210 ps->expout.reset (XRESIZEVAR (expression, ps->expout.release (),
212 + EXP_ELEM_TO_BYTES (ps->expout_size))));
214 ps->expout->elts[ps->expout_ptr++] = *expelt;
218 write_exp_elt_opcode (struct parser_state *ps, enum exp_opcode expelt)
220 union exp_element tmp;
222 memset (&tmp, 0, sizeof (union exp_element));
224 write_exp_elt (ps, &tmp);
228 write_exp_elt_sym (struct parser_state *ps, struct symbol *expelt)
230 union exp_element tmp;
232 memset (&tmp, 0, sizeof (union exp_element));
234 write_exp_elt (ps, &tmp);
238 write_exp_elt_msym (struct parser_state *ps, minimal_symbol *expelt)
240 union exp_element tmp;
242 memset (&tmp, 0, sizeof (union exp_element));
243 tmp.msymbol = expelt;
244 write_exp_elt (ps, &tmp);
248 write_exp_elt_block (struct parser_state *ps, const struct block *b)
250 union exp_element tmp;
252 memset (&tmp, 0, sizeof (union exp_element));
254 write_exp_elt (ps, &tmp);
258 write_exp_elt_objfile (struct parser_state *ps, struct objfile *objfile)
260 union exp_element tmp;
262 memset (&tmp, 0, sizeof (union exp_element));
263 tmp.objfile = objfile;
264 write_exp_elt (ps, &tmp);
268 write_exp_elt_longcst (struct parser_state *ps, LONGEST expelt)
270 union exp_element tmp;
272 memset (&tmp, 0, sizeof (union exp_element));
273 tmp.longconst = expelt;
274 write_exp_elt (ps, &tmp);
278 write_exp_elt_floatcst (struct parser_state *ps, const gdb_byte expelt[16])
280 union exp_element tmp;
283 for (index = 0; index < 16; index++)
284 tmp.floatconst[index] = expelt[index];
286 write_exp_elt (ps, &tmp);
290 write_exp_elt_type (struct parser_state *ps, struct type *expelt)
292 union exp_element tmp;
294 memset (&tmp, 0, sizeof (union exp_element));
296 write_exp_elt (ps, &tmp);
300 write_exp_elt_intern (struct parser_state *ps, struct internalvar *expelt)
302 union exp_element tmp;
304 memset (&tmp, 0, sizeof (union exp_element));
305 tmp.internalvar = expelt;
306 write_exp_elt (ps, &tmp);
309 /* Add a string constant to the end of the expression.
311 String constants are stored by first writing an expression element
312 that contains the length of the string, then stuffing the string
313 constant itself into however many expression elements are needed
314 to hold it, and then writing another expression element that contains
315 the length of the string. I.e. an expression element at each end of
316 the string records the string length, so you can skip over the
317 expression elements containing the actual string bytes from either
318 end of the string. Note that this also allows gdb to handle
319 strings with embedded null bytes, as is required for some languages.
321 Don't be fooled by the fact that the string is null byte terminated,
322 this is strictly for the convenience of debugging gdb itself.
323 Gdb does not depend up the string being null terminated, since the
324 actual length is recorded in expression elements at each end of the
325 string. The null byte is taken into consideration when computing how
326 many expression elements are required to hold the string constant, of
331 write_exp_string (struct parser_state *ps, struct stoken str)
333 int len = str.length;
337 /* Compute the number of expression elements required to hold the string
338 (including a null byte terminator), along with one expression element
339 at each end to record the actual string length (not including the
340 null byte terminator). */
342 lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1);
344 increase_expout_size (ps, lenelt);
346 /* Write the leading length expression element (which advances the current
347 expression element index), then write the string constant followed by a
348 terminating null byte, and then write the trailing length expression
351 write_exp_elt_longcst (ps, (LONGEST) len);
352 strdata = (char *) &ps->expout->elts[ps->expout_ptr];
353 memcpy (strdata, str.ptr, len);
354 *(strdata + len) = '\0';
355 ps->expout_ptr += lenelt - 2;
356 write_exp_elt_longcst (ps, (LONGEST) len);
359 /* Add a vector of string constants to the end of the expression.
361 This adds an OP_STRING operation, but encodes the contents
362 differently from write_exp_string. The language is expected to
363 handle evaluation of this expression itself.
365 After the usual OP_STRING header, TYPE is written into the
366 expression as a long constant. The interpretation of this field is
367 up to the language evaluator.
369 Next, each string in VEC is written. The length is written as a
370 long constant, followed by the contents of the string. */
373 write_exp_string_vector (struct parser_state *ps, int type,
374 struct stoken_vector *vec)
379 /* Compute the size. We compute the size in number of slots to
380 avoid issues with string padding. */
382 for (i = 0; i < vec->len; ++i)
384 /* One slot for the length of this element, plus the number of
385 slots needed for this string. */
386 n_slots += 1 + BYTES_TO_EXP_ELEM (vec->tokens[i].length);
389 /* One more slot for the type of the string. */
392 /* Now compute a phony string length. */
393 len = EXP_ELEM_TO_BYTES (n_slots) - 1;
396 increase_expout_size (ps, n_slots);
398 write_exp_elt_opcode (ps, OP_STRING);
399 write_exp_elt_longcst (ps, len);
400 write_exp_elt_longcst (ps, type);
402 for (i = 0; i < vec->len; ++i)
404 write_exp_elt_longcst (ps, vec->tokens[i].length);
405 memcpy (&ps->expout->elts[ps->expout_ptr], vec->tokens[i].ptr,
406 vec->tokens[i].length);
407 ps->expout_ptr += BYTES_TO_EXP_ELEM (vec->tokens[i].length);
410 write_exp_elt_longcst (ps, len);
411 write_exp_elt_opcode (ps, OP_STRING);
414 /* Add a bitstring constant to the end of the expression.
416 Bitstring constants are stored by first writing an expression element
417 that contains the length of the bitstring (in bits), then stuffing the
418 bitstring constant itself into however many expression elements are
419 needed to hold it, and then writing another expression element that
420 contains the length of the bitstring. I.e. an expression element at
421 each end of the bitstring records the bitstring length, so you can skip
422 over the expression elements containing the actual bitstring bytes from
423 either end of the bitstring. */
426 write_exp_bitstring (struct parser_state *ps, struct stoken str)
428 int bits = str.length; /* length in bits */
429 int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT;
433 /* Compute the number of expression elements required to hold the bitstring,
434 along with one expression element at each end to record the actual
435 bitstring length in bits. */
437 lenelt = 2 + BYTES_TO_EXP_ELEM (len);
439 increase_expout_size (ps, lenelt);
441 /* Write the leading length expression element (which advances the current
442 expression element index), then write the bitstring constant, and then
443 write the trailing length expression element. */
445 write_exp_elt_longcst (ps, (LONGEST) bits);
446 strdata = (char *) &ps->expout->elts[ps->expout_ptr];
447 memcpy (strdata, str.ptr, len);
448 ps->expout_ptr += lenelt - 2;
449 write_exp_elt_longcst (ps, (LONGEST) bits);
452 /* Return the type of MSYMBOL, a minimal symbol of OBJFILE. If
453 ADDRESS_P is not NULL, set it to the MSYMBOL's resolved
457 find_minsym_type_and_address (minimal_symbol *msymbol,
458 struct objfile *objfile,
459 CORE_ADDR *address_p)
461 bound_minimal_symbol bound_msym = {msymbol, objfile};
462 struct obj_section *section = MSYMBOL_OBJ_SECTION (objfile, msymbol);
463 enum minimal_symbol_type type = MSYMBOL_TYPE (msymbol);
465 bool is_tls = (section != NULL
466 && section->the_bfd_section->flags & SEC_THREAD_LOCAL);
468 /* The minimal symbol might point to a function descriptor;
469 resolve it to the actual code address instead. */
473 /* Addresses of TLS symbols are really offsets into a
474 per-objfile/per-thread storage block. */
475 addr = MSYMBOL_VALUE_RAW_ADDRESS (bound_msym.minsym);
477 else if (msymbol_is_function (objfile, msymbol, &addr))
479 if (addr != BMSYMBOL_VALUE_ADDRESS (bound_msym))
481 /* This means we resolved a function descriptor, and we now
482 have an address for a code/text symbol instead of a data
484 if (MSYMBOL_TYPE (msymbol) == mst_data_gnu_ifunc)
485 type = mst_text_gnu_ifunc;
492 addr = BMSYMBOL_VALUE_ADDRESS (bound_msym);
494 if (overlay_debugging)
495 addr = symbol_overlayed_address (addr, section);
499 /* Skip translation if caller does not need the address. */
500 if (address_p != NULL)
501 *address_p = target_translate_tls_address (objfile, addr);
502 return objfile_type (objfile)->nodebug_tls_symbol;
505 if (address_p != NULL)
512 case mst_solib_trampoline:
513 return objfile_type (objfile)->nodebug_text_symbol;
515 case mst_text_gnu_ifunc:
516 return objfile_type (objfile)->nodebug_text_gnu_ifunc_symbol;
522 return objfile_type (objfile)->nodebug_data_symbol;
524 case mst_slot_got_plt:
525 return objfile_type (objfile)->nodebug_got_plt_symbol;
528 return objfile_type (objfile)->nodebug_unknown_symbol;
532 /* Add the appropriate elements for a minimal symbol to the end of
536 write_exp_msymbol (struct parser_state *ps,
537 struct bound_minimal_symbol bound_msym)
539 write_exp_elt_opcode (ps, OP_VAR_MSYM_VALUE);
540 write_exp_elt_objfile (ps, bound_msym.objfile);
541 write_exp_elt_msym (ps, bound_msym.minsym);
542 write_exp_elt_opcode (ps, OP_VAR_MSYM_VALUE);
545 /* Mark the current index as the starting location of a structure
546 expression. This is used when completing on field names. */
549 mark_struct_expression (struct parser_state *ps)
551 gdb_assert (parse_completion
552 && expout_tag_completion_type == TYPE_CODE_UNDEF);
553 expout_last_struct = ps->expout_ptr;
556 /* Indicate that the current parser invocation is completing a tag.
557 TAG is the type code of the tag, and PTR and LENGTH represent the
558 start of the tag name. */
561 mark_completion_tag (enum type_code tag, const char *ptr, int length)
563 gdb_assert (parse_completion
564 && expout_tag_completion_type == TYPE_CODE_UNDEF
565 && expout_completion_name == NULL
566 && expout_last_struct == -1);
567 gdb_assert (tag == TYPE_CODE_UNION
568 || tag == TYPE_CODE_STRUCT
569 || tag == TYPE_CODE_ENUM);
570 expout_tag_completion_type = tag;
571 expout_completion_name.reset (xstrndup (ptr, length));
575 /* Recognize tokens that start with '$'. These include:
577 $regname A native register name or a "standard
580 $variable A convenience variable with a name chosen
583 $digits Value history with index <digits>, starting
584 from the first value which has index 1.
586 $$digits Value history with index <digits> relative
587 to the last value. I.e. $$0 is the last
588 value, $$1 is the one previous to that, $$2
589 is the one previous to $$1, etc.
591 $ | $0 | $$0 The last value in the value history.
593 $$ An abbreviation for the second to the last
594 value in the value history, I.e. $$1 */
597 write_dollar_variable (struct parser_state *ps, struct stoken str)
599 struct block_symbol sym;
600 struct bound_minimal_symbol msym;
601 struct internalvar *isym = NULL;
603 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
604 and $$digits (equivalent to $<-digits> if you could type that). */
608 /* Double dollar means negate the number and add -1 as well.
609 Thus $$ alone means -1. */
610 if (str.length >= 2 && str.ptr[1] == '$')
617 /* Just dollars (one or two). */
621 /* Is the rest of the token digits? */
622 for (; i < str.length; i++)
623 if (!(str.ptr[i] >= '0' && str.ptr[i] <= '9'))
627 i = atoi (str.ptr + 1 + negate);
633 /* Handle tokens that refer to machine registers:
634 $ followed by a register name. */
635 i = user_reg_map_name_to_regnum (parse_gdbarch (ps),
636 str.ptr + 1, str.length - 1);
638 goto handle_register;
640 /* Any names starting with $ are probably debugger internal variables. */
642 isym = lookup_only_internalvar (copy_name (str) + 1);
645 write_exp_elt_opcode (ps, OP_INTERNALVAR);
646 write_exp_elt_intern (ps, isym);
647 write_exp_elt_opcode (ps, OP_INTERNALVAR);
651 /* On some systems, such as HP-UX and hppa-linux, certain system routines
652 have names beginning with $ or $$. Check for those, first. */
654 sym = lookup_symbol (copy_name (str), NULL, VAR_DOMAIN, NULL);
657 write_exp_elt_opcode (ps, OP_VAR_VALUE);
658 write_exp_elt_block (ps, sym.block);
659 write_exp_elt_sym (ps, sym.symbol);
660 write_exp_elt_opcode (ps, OP_VAR_VALUE);
663 msym = lookup_bound_minimal_symbol (copy_name (str));
666 write_exp_msymbol (ps, msym);
670 /* Any other names are assumed to be debugger internal variables. */
672 write_exp_elt_opcode (ps, OP_INTERNALVAR);
673 write_exp_elt_intern (ps, create_internalvar (copy_name (str) + 1));
674 write_exp_elt_opcode (ps, OP_INTERNALVAR);
677 write_exp_elt_opcode (ps, OP_LAST);
678 write_exp_elt_longcst (ps, (LONGEST) i);
679 write_exp_elt_opcode (ps, OP_LAST);
682 write_exp_elt_opcode (ps, OP_REGISTER);
685 write_exp_string (ps, str);
686 write_exp_elt_opcode (ps, OP_REGISTER);
687 innermost_block.update (expression_context_block,
688 INNERMOST_BLOCK_FOR_REGISTERS);
694 find_template_name_end (const char *p)
697 int just_seen_right = 0;
698 int just_seen_colon = 0;
699 int just_seen_space = 0;
701 if (!p || (*p != '<'))
712 /* In future, may want to allow these?? */
715 depth++; /* start nested template */
716 if (just_seen_colon || just_seen_right || just_seen_space)
717 return 0; /* but not after : or :: or > or space */
720 if (just_seen_colon || just_seen_right)
721 return 0; /* end a (nested?) template */
722 just_seen_right = 1; /* but not after : or :: */
723 if (--depth == 0) /* also disallow >>, insist on > > */
724 return ++p; /* if outermost ended, return */
727 if (just_seen_space || (just_seen_colon > 1))
728 return 0; /* nested class spec coming up */
729 just_seen_colon++; /* we allow :: but not :::: */
734 if (!((*p >= 'a' && *p <= 'z') || /* allow token chars */
735 (*p >= 'A' && *p <= 'Z') ||
736 (*p >= '0' && *p <= '9') ||
737 (*p == '_') || (*p == ',') || /* commas for template args */
738 (*p == '&') || (*p == '*') || /* pointer and ref types */
739 (*p == '(') || (*p == ')') || /* function types */
740 (*p == '[') || (*p == ']'))) /* array types */
754 /* Return a null-terminated temporary copy of the name of a string token.
756 Tokens that refer to names do so with explicit pointer and length,
757 so they can share the storage that lexptr is parsing.
758 When it is necessary to pass a name to a function that expects
759 a null-terminated string, the substring is copied out
760 into a separate block of storage.
762 N.B. A single buffer is reused on each call. */
765 copy_name (struct stoken token)
767 /* A temporary buffer for identifiers, so we can null-terminate them.
768 We allocate this with xrealloc. parse_exp_1 used to allocate with
769 alloca, using the size of the whole expression as a conservative
770 estimate of the space needed. However, macro expansion can
771 introduce names longer than the original expression; there's no
772 practical way to know beforehand how large that might be. */
773 static char *namecopy;
774 static size_t namecopy_size;
776 /* Make sure there's enough space for the token. */
777 if (namecopy_size < token.length + 1)
779 namecopy_size = token.length + 1;
780 namecopy = (char *) xrealloc (namecopy, token.length + 1);
783 memcpy (namecopy, token.ptr, token.length);
784 namecopy[token.length] = 0;
790 /* See comments on parser-defs.h. */
793 prefixify_expression (struct expression *expr)
795 gdb_assert (expr->nelts > 0);
796 int len = sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts);
797 struct expression *temp;
798 int inpos = expr->nelts, outpos = 0;
800 temp = (struct expression *) alloca (len);
802 /* Copy the original expression into temp. */
803 memcpy (temp, expr, len);
805 return prefixify_subexp (temp, expr, inpos, outpos);
808 /* Return the number of exp_elements in the postfix subexpression
809 of EXPR whose operator is at index ENDPOS - 1 in EXPR. */
812 length_of_subexp (struct expression *expr, int endpos)
816 operator_length (expr, endpos, &oplen, &args);
820 oplen += length_of_subexp (expr, endpos - oplen);
827 /* Sets *OPLENP to the length of the operator whose (last) index is
828 ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
832 operator_length (const struct expression *expr, int endpos, int *oplenp,
835 expr->language_defn->la_exp_desc->operator_length (expr, endpos,
839 /* Default value for operator_length in exp_descriptor vectors. */
842 operator_length_standard (const struct expression *expr, int endpos,
843 int *oplenp, int *argsp)
847 enum range_type range_type;
851 error (_("?error in operator_length_standard"));
853 i = (int) expr->elts[endpos - 1].opcode;
859 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
860 oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1);
866 case OP_VAR_MSYM_VALUE:
870 case OP_FUNC_STATIC_VAR:
871 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
872 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
880 case OP_VAR_ENTRY_VALUE:
890 case OP_F77_UNDETERMINED_ARGLIST:
892 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
896 oplen = 5 + longest_to_int (expr->elts[endpos - 2].longconst);
900 case OP_OBJC_MSGCALL: /* Objective C message (method) call. */
902 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
911 case UNOP_DYNAMIC_CAST:
912 case UNOP_REINTERPRET_CAST:
913 case UNOP_MEMVAL_TYPE:
942 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
943 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
948 case STRUCTOP_STRUCT:
955 case OP_OBJC_NSSTRING: /* Objective C Foundation Class
956 NSString constant. */
957 case OP_OBJC_SELECTOR: /* Objective C "@selector" pseudo-op. */
959 oplen = longest_to_int (expr->elts[endpos - 2].longconst);
960 oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1);
965 args = longest_to_int (expr->elts[endpos - 2].longconst);
966 args -= longest_to_int (expr->elts[endpos - 3].longconst);
976 case MULTI_SUBSCRIPT:
978 args = 1 + longest_to_int (expr->elts[endpos - 2].longconst);
981 case BINOP_ASSIGN_MODIFY:
993 range_type = (enum range_type)
994 longest_to_int (expr->elts[endpos - 2].longconst);
998 case LOW_BOUND_DEFAULT:
999 case LOW_BOUND_DEFAULT_EXCLUSIVE:
1000 case HIGH_BOUND_DEFAULT:
1003 case BOTH_BOUND_DEFAULT:
1006 case NONE_BOUND_DEFAULT:
1007 case NONE_BOUND_DEFAULT_EXCLUSIVE:
1015 args = 1 + (i < (int) BINOP_END);
1022 /* Copy the subexpression ending just before index INEND in INEXPR
1023 into OUTEXPR, starting at index OUTBEG.
1024 In the process, convert it from suffix to prefix form.
1025 If EXPOUT_LAST_STRUCT is -1, then this function always returns -1.
1026 Otherwise, it returns the index of the subexpression which is the
1027 left-hand-side of the expression at EXPOUT_LAST_STRUCT. */
1030 prefixify_subexp (struct expression *inexpr,
1031 struct expression *outexpr, int inend, int outbeg)
1039 operator_length (inexpr, inend, &oplen, &args);
1041 /* Copy the final operator itself, from the end of the input
1042 to the beginning of the output. */
1044 memcpy (&outexpr->elts[outbeg], &inexpr->elts[inend],
1045 EXP_ELEM_TO_BYTES (oplen));
1048 if (expout_last_struct == inend)
1049 result = outbeg - oplen;
1051 /* Find the lengths of the arg subexpressions. */
1052 arglens = (int *) alloca (args * sizeof (int));
1053 for (i = args - 1; i >= 0; i--)
1055 oplen = length_of_subexp (inexpr, inend);
1060 /* Now copy each subexpression, preserving the order of
1061 the subexpressions, but prefixifying each one.
1062 In this loop, inend starts at the beginning of
1063 the expression this level is working on
1064 and marches forward over the arguments.
1065 outbeg does similarly in the output. */
1066 for (i = 0; i < args; i++)
1072 r = prefixify_subexp (inexpr, outexpr, inend, outbeg);
1075 /* Return immediately. We probably have only parsed a
1076 partial expression, so we don't want to try to reverse
1077 the other operands. */
1086 /* Read an expression from the string *STRINGPTR points to,
1087 parse it, and return a pointer to a struct expression that we malloc.
1088 Use block BLOCK as the lexical context for variable names;
1089 if BLOCK is zero, use the block of the selected stack frame.
1090 Meanwhile, advance *STRINGPTR to point after the expression,
1091 at the first nonwhite character that is not part of the expression
1092 (possibly a null character).
1094 If COMMA is nonzero, stop if a comma is reached. */
1097 parse_exp_1 (const char **stringptr, CORE_ADDR pc, const struct block *block,
1098 int comma, innermost_block_tracker_types tracker_types)
1100 return parse_exp_in_context (stringptr, pc, block, comma, 0, NULL,
1104 /* As for parse_exp_1, except that if VOID_CONTEXT_P, then
1105 no value is expected from the expression.
1106 OUT_SUBEXP is set when attempting to complete a field name; in this
1107 case it is set to the index of the subexpression on the
1108 left-hand-side of the struct op. If not doing such completion, it
1109 is left untouched. */
1111 static expression_up
1112 parse_exp_in_context (const char **stringptr, CORE_ADDR pc,
1113 const struct block *block,
1114 int comma, int void_context_p, int *out_subexp,
1115 innermost_block_tracker_types tracker_types)
1117 const struct language_defn *lang = NULL;
1120 lexptr = *stringptr;
1124 type_stack.elements.clear ();
1125 expout_last_struct = -1;
1126 expout_tag_completion_type = TYPE_CODE_UNDEF;
1127 expout_completion_name.reset ();
1128 innermost_block.reset (tracker_types);
1130 comma_terminates = comma;
1132 if (lexptr == 0 || *lexptr == 0)
1133 error_no_arg (_("expression to compute"));
1135 std::vector<int> funcalls;
1136 scoped_restore save_funcall_chain = make_scoped_restore (&funcall_chain,
1139 expression_context_block = block;
1141 /* If no context specified, try using the current frame, if any. */
1142 if (!expression_context_block)
1143 expression_context_block = get_selected_block (&expression_context_pc);
1145 expression_context_pc = BLOCK_ENTRY_PC (expression_context_block);
1147 expression_context_pc = pc;
1149 /* Fall back to using the current source static context, if any. */
1151 if (!expression_context_block)
1153 struct symtab_and_line cursal = get_current_source_symtab_and_line ();
1155 expression_context_block
1156 = BLOCKVECTOR_BLOCK (SYMTAB_BLOCKVECTOR (cursal.symtab),
1158 if (expression_context_block)
1159 expression_context_pc = BLOCK_ENTRY_PC (expression_context_block);
1162 if (language_mode == language_mode_auto && block != NULL)
1164 /* Find the language associated to the given context block.
1165 Default to the current language if it can not be determined.
1167 Note that using the language corresponding to the current frame
1168 can sometimes give unexpected results. For instance, this
1169 routine is often called several times during the inferior
1170 startup phase to re-parse breakpoint expressions after
1171 a new shared library has been loaded. The language associated
1172 to the current frame at this moment is not relevant for
1173 the breakpoint. Using it would therefore be silly, so it seems
1174 better to rely on the current language rather than relying on
1175 the current frame language to parse the expression. That's why
1176 we do the following language detection only if the context block
1177 has been specifically provided. */
1178 struct symbol *func = block_linkage_function (block);
1181 lang = language_def (SYMBOL_LANGUAGE (func));
1182 if (lang == NULL || lang->la_language == language_unknown)
1183 lang = current_language;
1186 lang = current_language;
1188 /* get_current_arch may reset CURRENT_LANGUAGE via select_frame.
1189 While we need CURRENT_LANGUAGE to be set to LANG (for lookup_symbol
1190 and others called from *.y) ensure CURRENT_LANGUAGE gets restored
1191 to the value matching SELECTED_FRAME as set by get_current_arch. */
1193 parser_state ps (10, lang, get_current_arch ());
1195 scoped_restore_current_language lang_saver;
1196 set_language (lang->la_language);
1200 lang->la_parser (&ps);
1202 CATCH (except, RETURN_MASK_ALL)
1204 /* If parsing for completion, allow this to succeed; but if no
1205 expression elements have been written, then there's nothing
1207 if (! parse_completion || ps.expout_ptr == 0)
1208 throw_exception (except);
1212 /* We have to operate on an "expression *", due to la_post_parser,
1213 which explains this funny-looking double release. */
1214 expression_up result = ps.release ();
1216 /* Convert expression from postfix form as generated by yacc
1217 parser, to a prefix form. */
1219 if (expressiondebug)
1220 dump_raw_expression (result.get (), gdb_stdlog,
1221 "before conversion to prefix form");
1223 subexp = prefixify_expression (result.get ());
1225 *out_subexp = subexp;
1227 lang->la_post_parser (&result, void_context_p);
1229 if (expressiondebug)
1230 dump_prefix_expression (result.get (), gdb_stdlog);
1232 *stringptr = lexptr;
1236 /* Parse STRING as an expression, and complain if this fails
1237 to use up all of the contents of STRING. */
1240 parse_expression (const char *string)
1242 expression_up exp = parse_exp_1 (&string, 0, 0, 0);
1244 error (_("Junk after end of expression."));
1248 /* Same as parse_expression, but using the given language (LANG)
1249 to parse the expression. */
1252 parse_expression_with_language (const char *string, enum language lang)
1254 gdb::optional<scoped_restore_current_language> lang_saver;
1255 if (current_language->la_language != lang)
1257 lang_saver.emplace ();
1258 set_language (lang);
1261 return parse_expression (string);
1264 /* Parse STRING as an expression. If parsing ends in the middle of a
1265 field reference, return the type of the left-hand-side of the
1266 reference; furthermore, if the parsing ends in the field name,
1267 return the field name in *NAME. If the parsing ends in the middle
1268 of a field reference, but the reference is somehow invalid, throw
1269 an exception. In all other cases, return NULL. */
1272 parse_expression_for_completion (const char *string,
1273 gdb::unique_xmalloc_ptr<char> *name,
1274 enum type_code *code)
1282 parse_completion = 1;
1283 exp = parse_exp_in_context (&string, 0, 0, 0, 0, &subexp,
1284 INNERMOST_BLOCK_FOR_SYMBOLS);
1286 CATCH (except, RETURN_MASK_ERROR)
1288 /* Nothing, EXP remains NULL. */
1292 parse_completion = 0;
1296 if (expout_tag_completion_type != TYPE_CODE_UNDEF)
1298 *code = expout_tag_completion_type;
1299 *name = std::move (expout_completion_name);
1303 if (expout_last_struct == -1)
1306 const char *fieldname = extract_field_op (exp.get (), &subexp);
1307 if (fieldname == NULL)
1313 name->reset (xstrdup (fieldname));
1314 /* This might throw an exception. If so, we want to let it
1316 val = evaluate_subexpression_type (exp.get (), subexp);
1318 return value_type (val);
1321 /* A post-parser that does nothing. */
1324 null_post_parser (expression_up *exp, int void_context_p)
1328 /* Parse floating point value P of length LEN.
1329 Return false if invalid, true if valid.
1330 The successfully parsed number is stored in DATA in
1331 target format for floating-point type TYPE.
1333 NOTE: This accepts the floating point syntax that sscanf accepts. */
1336 parse_float (const char *p, int len,
1337 const struct type *type, gdb_byte *data)
1339 return target_float_from_string (data, type, std::string (p, len));
1342 /* Stuff for maintaining a stack of types. Currently just used by C, but
1343 probably useful for any language which declares its types "backwards". */
1345 /* A helper function for insert_type and insert_type_address_space.
1346 This does work of expanding the type stack and inserting the new
1347 element, ELEMENT, into the stack at location SLOT. */
1350 insert_into_type_stack (int slot, union type_stack_elt element)
1352 gdb_assert (slot <= type_stack.elements.size ());
1353 type_stack.elements.insert (type_stack.elements.begin () + slot, element);
1356 /* Insert a new type, TP, at the bottom of the type stack. If TP is
1357 tp_pointer, tp_reference or tp_rvalue_reference, it is inserted at the
1358 bottom. If TP is a qualifier, it is inserted at slot 1 (just above a
1359 previous tp_pointer) if there is anything on the stack, or simply pushed
1360 if the stack is empty. Other values for TP are invalid. */
1363 insert_type (enum type_pieces tp)
1365 union type_stack_elt element;
1368 gdb_assert (tp == tp_pointer || tp == tp_reference
1369 || tp == tp_rvalue_reference || tp == tp_const
1370 || tp == tp_volatile);
1372 /* If there is anything on the stack (we know it will be a
1373 tp_pointer), insert the qualifier above it. Otherwise, simply
1374 push this on the top of the stack. */
1375 if (!type_stack.elements.empty () && (tp == tp_const || tp == tp_volatile))
1381 insert_into_type_stack (slot, element);
1385 push_type (enum type_pieces tp)
1389 type_stack.elements.push_back (elt);
1393 push_type_int (int n)
1397 type_stack.elements.push_back (elt);
1400 /* Insert a tp_space_identifier and the corresponding address space
1401 value into the stack. STRING is the name of an address space, as
1402 recognized by address_space_name_to_int. If the stack is empty,
1403 the new elements are simply pushed. If the stack is not empty,
1404 this function assumes that the first item on the stack is a
1405 tp_pointer, and the new values are inserted above the first
1409 insert_type_address_space (struct parser_state *pstate, char *string)
1411 union type_stack_elt element;
1414 /* If there is anything on the stack (we know it will be a
1415 tp_pointer), insert the address space qualifier above it.
1416 Otherwise, simply push this on the top of the stack. */
1417 if (!type_stack.elements.empty ())
1422 element.piece = tp_space_identifier;
1423 insert_into_type_stack (slot, element);
1424 element.int_val = address_space_name_to_int (parse_gdbarch (pstate),
1426 insert_into_type_stack (slot, element);
1432 if (!type_stack.elements.empty ())
1434 type_stack_elt elt = type_stack.elements.back ();
1435 type_stack.elements.pop_back ();
1444 if (!type_stack.elements.empty ())
1446 type_stack_elt elt = type_stack.elements.back ();
1447 type_stack.elements.pop_back ();
1450 /* "Can't happen". */
1454 /* Pop a type list element from the global type stack. */
1456 static std::vector<struct type *> *
1459 gdb_assert (!type_stack.elements.empty ());
1460 type_stack_elt elt = type_stack.elements.back ();
1461 type_stack.elements.pop_back ();
1462 return elt.typelist_val;
1465 /* Pop a type_stack element from the global type stack. */
1467 static struct type_stack *
1468 pop_type_stack (void)
1470 gdb_assert (!type_stack.elements.empty ());
1471 type_stack_elt elt = type_stack.elements.back ();
1472 type_stack.elements.pop_back ();
1473 return elt.stack_val;
1476 /* Append the elements of the type stack FROM to the type stack TO.
1477 Always returns TO. */
1480 append_type_stack (struct type_stack *to, struct type_stack *from)
1482 to->elements.insert (to->elements.end (), from->elements.begin (),
1483 from->elements.end ());
1487 /* Push the type stack STACK as an element on the global type stack. */
1490 push_type_stack (struct type_stack *stack)
1493 elt.stack_val = stack;
1494 type_stack.elements.push_back (elt);
1495 push_type (tp_type_stack);
1498 /* Copy the global type stack into a newly allocated type stack and
1499 return it. The global stack is cleared. The returned type stack
1500 must be freed with delete. */
1503 get_type_stack (void)
1505 struct type_stack *result = new struct type_stack (std::move (type_stack));
1506 type_stack.elements.clear ();
1510 /* Push a function type with arguments onto the global type stack.
1511 LIST holds the argument types. If the final item in LIST is NULL,
1512 then the function will be varargs. */
1515 push_typelist (std::vector<struct type *> *list)
1518 elt.typelist_val = list;
1519 type_stack.elements.push_back (elt);
1520 push_type (tp_function_with_arguments);
1523 /* Pop the type stack and return a type_instance_flags that
1524 corresponds the const/volatile qualifiers on the stack. This is
1525 called by the C++ parser when parsing methods types, and as such no
1526 other kind of type in the type stack is expected. */
1529 follow_type_instance_flags ()
1531 type_instance_flags flags = 0;
1534 switch (pop_type ())
1539 flags |= TYPE_INSTANCE_FLAG_CONST;
1542 flags |= TYPE_INSTANCE_FLAG_VOLATILE;
1545 gdb_assert_not_reached ("unrecognized tp_ value in follow_types");
1550 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1551 as modified by all the stuff on the stack. */
1553 follow_types (struct type *follow_type)
1557 int make_volatile = 0;
1558 int make_addr_space = 0;
1562 switch (pop_type ())
1567 follow_type = make_cv_type (make_const,
1568 TYPE_VOLATILE (follow_type),
1571 follow_type = make_cv_type (TYPE_CONST (follow_type),
1574 if (make_addr_space)
1575 follow_type = make_type_with_address_space (follow_type,
1577 make_const = make_volatile = 0;
1578 make_addr_space = 0;
1586 case tp_space_identifier:
1587 make_addr_space = pop_type_int ();
1590 follow_type = lookup_pointer_type (follow_type);
1592 follow_type = make_cv_type (make_const,
1593 TYPE_VOLATILE (follow_type),
1596 follow_type = make_cv_type (TYPE_CONST (follow_type),
1599 if (make_addr_space)
1600 follow_type = make_type_with_address_space (follow_type,
1602 make_const = make_volatile = 0;
1603 make_addr_space = 0;
1606 follow_type = lookup_lvalue_reference_type (follow_type);
1607 goto process_reference;
1608 case tp_rvalue_reference:
1609 follow_type = lookup_rvalue_reference_type (follow_type);
1612 follow_type = make_cv_type (make_const,
1613 TYPE_VOLATILE (follow_type),
1616 follow_type = make_cv_type (TYPE_CONST (follow_type),
1619 if (make_addr_space)
1620 follow_type = make_type_with_address_space (follow_type,
1622 make_const = make_volatile = 0;
1623 make_addr_space = 0;
1626 array_size = pop_type_int ();
1627 /* FIXME-type-allocation: need a way to free this type when we are
1630 lookup_array_range_type (follow_type,
1631 0, array_size >= 0 ? array_size - 1 : 0);
1633 TYPE_HIGH_BOUND_KIND (TYPE_INDEX_TYPE (follow_type))
1637 /* FIXME-type-allocation: need a way to free this type when we are
1639 follow_type = lookup_function_type (follow_type);
1642 case tp_function_with_arguments:
1644 std::vector<struct type *> *args = pop_typelist ();
1647 = lookup_function_type_with_arguments (follow_type,
1655 struct type_stack *stack = pop_type_stack ();
1656 /* Sort of ugly, but not really much worse than the
1658 struct type_stack save = type_stack;
1660 type_stack = *stack;
1661 follow_type = follow_types (follow_type);
1662 gdb_assert (type_stack.elements.empty ());
1668 gdb_assert_not_reached ("unrecognized tp_ value in follow_types");
1673 /* This function avoids direct calls to fprintf
1674 in the parser generated debug code. */
1676 parser_fprintf (FILE *x, const char *y, ...)
1682 vfprintf_unfiltered (gdb_stderr, y, args);
1685 fprintf_unfiltered (gdb_stderr, " Unknown FILE used.\n");
1686 vfprintf_unfiltered (gdb_stderr, y, args);
1691 /* Implementation of the exp_descriptor method operator_check. */
1694 operator_check_standard (struct expression *exp, int pos,
1695 int (*objfile_func) (struct objfile *objfile,
1699 const union exp_element *const elts = exp->elts;
1700 struct type *type = NULL;
1701 struct objfile *objfile = NULL;
1703 /* Extended operators should have been already handled by exp_descriptor
1704 iterate method of its specific language. */
1705 gdb_assert (elts[pos].opcode < OP_EXTENDED0);
1707 /* Track the callers of write_exp_elt_type for this table. */
1709 switch (elts[pos].opcode)
1721 type = elts[pos + 1].type;
1726 LONGEST arg, nargs = elts[pos + 2].longconst;
1728 for (arg = 0; arg < nargs; arg++)
1730 struct type *inst_type = elts[pos + 3 + arg].type;
1731 struct objfile *inst_objfile = TYPE_OBJFILE (inst_type);
1733 if (inst_objfile && (*objfile_func) (inst_objfile, data))
1741 const struct block *const block = elts[pos + 1].block;
1742 const struct symbol *const symbol = elts[pos + 2].symbol;
1744 /* Check objfile where the variable itself is placed.
1745 SYMBOL_OBJ_SECTION (symbol) may be NULL. */
1746 if ((*objfile_func) (symbol_objfile (symbol), data))
1749 /* Check objfile where is placed the code touching the variable. */
1750 objfile = lookup_objfile_from_block (block);
1752 type = SYMBOL_TYPE (symbol);
1755 case OP_VAR_MSYM_VALUE:
1756 objfile = elts[pos + 1].objfile;
1760 /* Invoke callbacks for TYPE and OBJFILE if they were set as non-NULL. */
1762 if (type && TYPE_OBJFILE (type)
1763 && (*objfile_func) (TYPE_OBJFILE (type), data))
1765 if (objfile && (*objfile_func) (objfile, data))
1771 /* Call OBJFILE_FUNC for any objfile found being referenced by EXP.
1772 OBJFILE_FUNC is never called with NULL OBJFILE. OBJFILE_FUNC get
1773 passed an arbitrary caller supplied DATA pointer. If OBJFILE_FUNC
1774 returns non-zero value then (any other) non-zero value is immediately
1775 returned to the caller. Otherwise zero is returned after iterating
1776 through whole EXP. */
1779 exp_iterate (struct expression *exp,
1780 int (*objfile_func) (struct objfile *objfile, void *data),
1785 for (endpos = exp->nelts; endpos > 0; )
1787 int pos, args, oplen = 0;
1789 operator_length (exp, endpos, &oplen, &args);
1790 gdb_assert (oplen > 0);
1792 pos = endpos - oplen;
1793 if (exp->language_defn->la_exp_desc->operator_check (exp, pos,
1794 objfile_func, data))
1803 /* Helper for exp_uses_objfile. */
1806 exp_uses_objfile_iter (struct objfile *exp_objfile, void *objfile_voidp)
1808 struct objfile *objfile = (struct objfile *) objfile_voidp;
1810 if (exp_objfile->separate_debug_objfile_backlink)
1811 exp_objfile = exp_objfile->separate_debug_objfile_backlink;
1813 return exp_objfile == objfile;
1816 /* Return 1 if EXP uses OBJFILE (and will become dangling when OBJFILE
1817 is unloaded), otherwise return 0. OBJFILE must not be a separate debug info
1821 exp_uses_objfile (struct expression *exp, struct objfile *objfile)
1823 gdb_assert (objfile->separate_debug_objfile_backlink == NULL);
1825 return exp_iterate (exp, exp_uses_objfile_iter, objfile);
1828 /* Reallocate the `expout' pointer inside PS so that it can accommodate
1829 at least LENELT expression elements. This function does nothing if
1830 there is enough room for the elements. */
1833 increase_expout_size (struct parser_state *ps, size_t lenelt)
1835 if ((ps->expout_ptr + lenelt) >= ps->expout_size)
1837 ps->expout_size = std::max (ps->expout_size * 2,
1838 ps->expout_ptr + lenelt + 10);
1839 ps->expout.reset (XRESIZEVAR (expression,
1840 ps->expout.release (),
1841 (sizeof (struct expression)
1842 + EXP_ELEM_TO_BYTES (ps->expout_size))));
1847 _initialize_parse (void)
1849 add_setshow_zuinteger_cmd ("expression", class_maintenance,
1851 _("Set expression debugging."),
1852 _("Show expression debugging."),
1853 _("When non-zero, the internal representation "
1854 "of expressions will be printed."),
1856 show_expressiondebug,
1857 &setdebuglist, &showdebuglist);
1858 add_setshow_boolean_cmd ("parser", class_maintenance,
1860 _("Set parser debugging."),
1861 _("Show parser debugging."),
1862 _("When non-zero, expression parser "
1863 "tracing will be enabled."),
1866 &setdebuglist, &showdebuglist);