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 static expression_up
parse_exp_in_context_1 (const char **, CORE_ADDR
,
121 const struct block
*, int,
124 /* Documented at it's declaration. */
127 innermost_block_tracker::update (const struct block
*b
,
128 innermost_block_tracker_types t
)
130 if ((m_types
& t
) != 0
131 && (m_innermost_block
== NULL
132 || contained_in (b
, m_innermost_block
)))
133 m_innermost_block
= b
;
136 /* Data structure for saving values of arglist_len for function calls whose
137 arguments contain other function calls. */
139 static std::vector
<int> *funcall_chain
;
141 /* Begin counting arguments for a function call,
142 saving the data about any containing call. */
147 funcall_chain
->push_back (arglist_len
);
151 /* Return the number of arguments in a function call just terminated,
152 and restore the data for the containing function call. */
157 int val
= arglist_len
;
158 arglist_len
= funcall_chain
->back ();
159 funcall_chain
->pop_back ();
165 /* See definition in parser-defs.h. */
167 parser_state::parser_state (size_t initial_size
,
168 const struct language_defn
*lang
,
169 struct gdbarch
*gdbarch
)
170 : expout_size (initial_size
),
171 expout (XNEWVAR (expression
,
173 + EXP_ELEM_TO_BYTES (expout_size
)))),
176 expout
->language_defn
= lang
;
177 expout
->gdbarch
= gdbarch
;
181 parser_state::release ()
183 /* Record the actual number of expression elements, and then
184 reallocate the expression memory so that we free up any
187 expout
->nelts
= expout_ptr
;
188 expout
.reset (XRESIZEVAR (expression
, expout
.release (),
190 + EXP_ELEM_TO_BYTES (expout_ptr
))));
192 return std::move (expout
);
195 /* This page contains the functions for adding data to the struct expression
196 being constructed. */
198 /* Add one element to the end of the expression. */
200 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
201 a register through here. */
204 write_exp_elt (struct parser_state
*ps
, const union exp_element
*expelt
)
206 if (ps
->expout_ptr
>= ps
->expout_size
)
208 ps
->expout_size
*= 2;
209 ps
->expout
.reset (XRESIZEVAR (expression
, ps
->expout
.release (),
211 + EXP_ELEM_TO_BYTES (ps
->expout_size
))));
213 ps
->expout
->elts
[ps
->expout_ptr
++] = *expelt
;
217 write_exp_elt_opcode (struct parser_state
*ps
, enum exp_opcode expelt
)
219 union exp_element tmp
;
221 memset (&tmp
, 0, sizeof (union exp_element
));
223 write_exp_elt (ps
, &tmp
);
227 write_exp_elt_sym (struct parser_state
*ps
, struct symbol
*expelt
)
229 union exp_element tmp
;
231 memset (&tmp
, 0, sizeof (union exp_element
));
233 write_exp_elt (ps
, &tmp
);
237 write_exp_elt_msym (struct parser_state
*ps
, minimal_symbol
*expelt
)
239 union exp_element tmp
;
241 memset (&tmp
, 0, sizeof (union exp_element
));
242 tmp
.msymbol
= expelt
;
243 write_exp_elt (ps
, &tmp
);
247 write_exp_elt_block (struct parser_state
*ps
, const struct block
*b
)
249 union exp_element tmp
;
251 memset (&tmp
, 0, sizeof (union exp_element
));
253 write_exp_elt (ps
, &tmp
);
257 write_exp_elt_objfile (struct parser_state
*ps
, struct objfile
*objfile
)
259 union exp_element tmp
;
261 memset (&tmp
, 0, sizeof (union exp_element
));
262 tmp
.objfile
= objfile
;
263 write_exp_elt (ps
, &tmp
);
267 write_exp_elt_longcst (struct parser_state
*ps
, LONGEST expelt
)
269 union exp_element tmp
;
271 memset (&tmp
, 0, sizeof (union exp_element
));
272 tmp
.longconst
= expelt
;
273 write_exp_elt (ps
, &tmp
);
277 write_exp_elt_floatcst (struct parser_state
*ps
, const gdb_byte expelt
[16])
279 union exp_element tmp
;
282 for (index
= 0; index
< 16; index
++)
283 tmp
.floatconst
[index
] = expelt
[index
];
285 write_exp_elt (ps
, &tmp
);
289 write_exp_elt_type (struct parser_state
*ps
, struct type
*expelt
)
291 union exp_element tmp
;
293 memset (&tmp
, 0, sizeof (union exp_element
));
295 write_exp_elt (ps
, &tmp
);
299 write_exp_elt_intern (struct parser_state
*ps
, struct internalvar
*expelt
)
301 union exp_element tmp
;
303 memset (&tmp
, 0, sizeof (union exp_element
));
304 tmp
.internalvar
= expelt
;
305 write_exp_elt (ps
, &tmp
);
308 /* Add a string constant to the end of the expression.
310 String constants are stored by first writing an expression element
311 that contains the length of the string, then stuffing the string
312 constant itself into however many expression elements are needed
313 to hold it, and then writing another expression element that contains
314 the length of the string. I.e. an expression element at each end of
315 the string records the string length, so you can skip over the
316 expression elements containing the actual string bytes from either
317 end of the string. Note that this also allows gdb to handle
318 strings with embedded null bytes, as is required for some languages.
320 Don't be fooled by the fact that the string is null byte terminated,
321 this is strictly for the convenience of debugging gdb itself.
322 Gdb does not depend up the string being null terminated, since the
323 actual length is recorded in expression elements at each end of the
324 string. The null byte is taken into consideration when computing how
325 many expression elements are required to hold the string constant, of
330 write_exp_string (struct parser_state
*ps
, struct stoken str
)
332 int len
= str
.length
;
336 /* Compute the number of expression elements required to hold the string
337 (including a null byte terminator), along with one expression element
338 at each end to record the actual string length (not including the
339 null byte terminator). */
341 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
+ 1);
343 increase_expout_size (ps
, lenelt
);
345 /* Write the leading length expression element (which advances the current
346 expression element index), then write the string constant followed by a
347 terminating null byte, and then write the trailing length expression
350 write_exp_elt_longcst (ps
, (LONGEST
) len
);
351 strdata
= (char *) &ps
->expout
->elts
[ps
->expout_ptr
];
352 memcpy (strdata
, str
.ptr
, len
);
353 *(strdata
+ len
) = '\0';
354 ps
->expout_ptr
+= lenelt
- 2;
355 write_exp_elt_longcst (ps
, (LONGEST
) len
);
358 /* Add a vector of string constants to the end of the expression.
360 This adds an OP_STRING operation, but encodes the contents
361 differently from write_exp_string. The language is expected to
362 handle evaluation of this expression itself.
364 After the usual OP_STRING header, TYPE is written into the
365 expression as a long constant. The interpretation of this field is
366 up to the language evaluator.
368 Next, each string in VEC is written. The length is written as a
369 long constant, followed by the contents of the string. */
372 write_exp_string_vector (struct parser_state
*ps
, int type
,
373 struct stoken_vector
*vec
)
378 /* Compute the size. We compute the size in number of slots to
379 avoid issues with string padding. */
381 for (i
= 0; i
< vec
->len
; ++i
)
383 /* One slot for the length of this element, plus the number of
384 slots needed for this string. */
385 n_slots
+= 1 + BYTES_TO_EXP_ELEM (vec
->tokens
[i
].length
);
388 /* One more slot for the type of the string. */
391 /* Now compute a phony string length. */
392 len
= EXP_ELEM_TO_BYTES (n_slots
) - 1;
395 increase_expout_size (ps
, n_slots
);
397 write_exp_elt_opcode (ps
, OP_STRING
);
398 write_exp_elt_longcst (ps
, len
);
399 write_exp_elt_longcst (ps
, type
);
401 for (i
= 0; i
< vec
->len
; ++i
)
403 write_exp_elt_longcst (ps
, vec
->tokens
[i
].length
);
404 memcpy (&ps
->expout
->elts
[ps
->expout_ptr
], vec
->tokens
[i
].ptr
,
405 vec
->tokens
[i
].length
);
406 ps
->expout_ptr
+= BYTES_TO_EXP_ELEM (vec
->tokens
[i
].length
);
409 write_exp_elt_longcst (ps
, len
);
410 write_exp_elt_opcode (ps
, OP_STRING
);
413 /* Add a bitstring constant to the end of the expression.
415 Bitstring constants are stored by first writing an expression element
416 that contains the length of the bitstring (in bits), then stuffing the
417 bitstring constant itself into however many expression elements are
418 needed to hold it, and then writing another expression element that
419 contains the length of the bitstring. I.e. an expression element at
420 each end of the bitstring records the bitstring length, so you can skip
421 over the expression elements containing the actual bitstring bytes from
422 either end of the bitstring. */
425 write_exp_bitstring (struct parser_state
*ps
, struct stoken str
)
427 int bits
= str
.length
; /* length in bits */
428 int len
= (bits
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
432 /* Compute the number of expression elements required to hold the bitstring,
433 along with one expression element at each end to record the actual
434 bitstring length in bits. */
436 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
);
438 increase_expout_size (ps
, lenelt
);
440 /* Write the leading length expression element (which advances the current
441 expression element index), then write the bitstring constant, and then
442 write the trailing length expression element. */
444 write_exp_elt_longcst (ps
, (LONGEST
) bits
);
445 strdata
= (char *) &ps
->expout
->elts
[ps
->expout_ptr
];
446 memcpy (strdata
, str
.ptr
, len
);
447 ps
->expout_ptr
+= lenelt
- 2;
448 write_exp_elt_longcst (ps
, (LONGEST
) bits
);
451 /* Return the type of MSYMBOL, a minimal symbol of OBJFILE. If
452 ADDRESS_P is not NULL, set it to the MSYMBOL's resolved
456 find_minsym_type_and_address (minimal_symbol
*msymbol
,
457 struct objfile
*objfile
,
458 CORE_ADDR
*address_p
)
460 bound_minimal_symbol bound_msym
= {msymbol
, objfile
};
461 struct obj_section
*section
= MSYMBOL_OBJ_SECTION (objfile
, msymbol
);
462 enum minimal_symbol_type type
= MSYMBOL_TYPE (msymbol
);
464 bool is_tls
= (section
!= NULL
465 && section
->the_bfd_section
->flags
& SEC_THREAD_LOCAL
);
467 /* The minimal symbol might point to a function descriptor;
468 resolve it to the actual code address instead. */
472 /* Addresses of TLS symbols are really offsets into a
473 per-objfile/per-thread storage block. */
474 addr
= MSYMBOL_VALUE_RAW_ADDRESS (bound_msym
.minsym
);
476 else if (msymbol_is_function (objfile
, msymbol
, &addr
))
478 if (addr
!= BMSYMBOL_VALUE_ADDRESS (bound_msym
))
480 /* This means we resolved a function descriptor, and we now
481 have an address for a code/text symbol instead of a data
483 if (MSYMBOL_TYPE (msymbol
) == mst_data_gnu_ifunc
)
484 type
= mst_text_gnu_ifunc
;
491 addr
= BMSYMBOL_VALUE_ADDRESS (bound_msym
);
493 if (overlay_debugging
)
494 addr
= symbol_overlayed_address (addr
, section
);
498 /* Skip translation if caller does not need the address. */
499 if (address_p
!= NULL
)
500 *address_p
= target_translate_tls_address (objfile
, addr
);
501 return objfile_type (objfile
)->nodebug_tls_symbol
;
504 if (address_p
!= NULL
)
511 case mst_solib_trampoline
:
512 return objfile_type (objfile
)->nodebug_text_symbol
;
514 case mst_text_gnu_ifunc
:
515 return objfile_type (objfile
)->nodebug_text_gnu_ifunc_symbol
;
521 return objfile_type (objfile
)->nodebug_data_symbol
;
523 case mst_slot_got_plt
:
524 return objfile_type (objfile
)->nodebug_got_plt_symbol
;
527 return objfile_type (objfile
)->nodebug_unknown_symbol
;
531 /* Add the appropriate elements for a minimal symbol to the end of
535 write_exp_msymbol (struct parser_state
*ps
,
536 struct bound_minimal_symbol bound_msym
)
538 write_exp_elt_opcode (ps
, OP_VAR_MSYM_VALUE
);
539 write_exp_elt_objfile (ps
, bound_msym
.objfile
);
540 write_exp_elt_msym (ps
, bound_msym
.minsym
);
541 write_exp_elt_opcode (ps
, OP_VAR_MSYM_VALUE
);
544 /* Mark the current index as the starting location of a structure
545 expression. This is used when completing on field names. */
548 mark_struct_expression (struct parser_state
*ps
)
550 gdb_assert (parse_completion
551 && expout_tag_completion_type
== TYPE_CODE_UNDEF
);
552 expout_last_struct
= ps
->expout_ptr
;
555 /* Indicate that the current parser invocation is completing a tag.
556 TAG is the type code of the tag, and PTR and LENGTH represent the
557 start of the tag name. */
560 mark_completion_tag (enum type_code tag
, const char *ptr
, int length
)
562 gdb_assert (parse_completion
563 && expout_tag_completion_type
== TYPE_CODE_UNDEF
564 && expout_completion_name
== NULL
565 && expout_last_struct
== -1);
566 gdb_assert (tag
== TYPE_CODE_UNION
567 || tag
== TYPE_CODE_STRUCT
568 || tag
== TYPE_CODE_ENUM
);
569 expout_tag_completion_type
= tag
;
570 expout_completion_name
.reset (xstrndup (ptr
, length
));
574 /* Recognize tokens that start with '$'. These include:
576 $regname A native register name or a "standard
579 $variable A convenience variable with a name chosen
582 $digits Value history with index <digits>, starting
583 from the first value which has index 1.
585 $$digits Value history with index <digits> relative
586 to the last value. I.e. $$0 is the last
587 value, $$1 is the one previous to that, $$2
588 is the one previous to $$1, etc.
590 $ | $0 | $$0 The last value in the value history.
592 $$ An abbreviation for the second to the last
593 value in the value history, I.e. $$1 */
596 write_dollar_variable (struct parser_state
*ps
, struct stoken str
)
598 struct block_symbol sym
;
599 struct bound_minimal_symbol msym
;
600 struct internalvar
*isym
= NULL
;
602 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
603 and $$digits (equivalent to $<-digits> if you could type that). */
607 /* Double dollar means negate the number and add -1 as well.
608 Thus $$ alone means -1. */
609 if (str
.length
>= 2 && str
.ptr
[1] == '$')
616 /* Just dollars (one or two). */
620 /* Is the rest of the token digits? */
621 for (; i
< str
.length
; i
++)
622 if (!(str
.ptr
[i
] >= '0' && str
.ptr
[i
] <= '9'))
626 i
= atoi (str
.ptr
+ 1 + negate
);
632 /* Handle tokens that refer to machine registers:
633 $ followed by a register name. */
634 i
= user_reg_map_name_to_regnum (parse_gdbarch (ps
),
635 str
.ptr
+ 1, str
.length
- 1);
637 goto handle_register
;
639 /* Any names starting with $ are probably debugger internal variables. */
641 isym
= lookup_only_internalvar (copy_name (str
) + 1);
644 write_exp_elt_opcode (ps
, OP_INTERNALVAR
);
645 write_exp_elt_intern (ps
, isym
);
646 write_exp_elt_opcode (ps
, OP_INTERNALVAR
);
650 /* On some systems, such as HP-UX and hppa-linux, certain system routines
651 have names beginning with $ or $$. Check for those, first. */
653 sym
= lookup_symbol (copy_name (str
), (struct block
*) 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
,
1100 return parse_exp_in_context (stringptr
, pc
, block
, comma
, 0, NULL
);
1103 static expression_up
1104 parse_exp_in_context (const char **stringptr
, CORE_ADDR pc
,
1105 const struct block
*block
,
1106 int comma
, int void_context_p
, int *out_subexp
)
1108 return parse_exp_in_context_1 (stringptr
, pc
, block
, comma
,
1109 void_context_p
, out_subexp
);
1112 /* As for parse_exp_1, except that if VOID_CONTEXT_P, then
1113 no value is expected from the expression.
1114 OUT_SUBEXP is set when attempting to complete a field name; in this
1115 case it is set to the index of the subexpression on the
1116 left-hand-side of the struct op. If not doing such completion, it
1117 is left untouched. */
1119 static expression_up
1120 parse_exp_in_context_1 (const char **stringptr
, CORE_ADDR pc
,
1121 const struct block
*block
,
1122 int comma
, int void_context_p
, int *out_subexp
)
1124 const struct language_defn
*lang
= NULL
;
1127 lexptr
= *stringptr
;
1131 type_stack
.elements
.clear ();
1132 expout_last_struct
= -1;
1133 expout_tag_completion_type
= TYPE_CODE_UNDEF
;
1134 expout_completion_name
.reset ();
1136 comma_terminates
= comma
;
1138 if (lexptr
== 0 || *lexptr
== 0)
1139 error_no_arg (_("expression to compute"));
1141 std::vector
<int> funcalls
;
1142 scoped_restore save_funcall_chain
= make_scoped_restore (&funcall_chain
,
1145 expression_context_block
= block
;
1147 /* If no context specified, try using the current frame, if any. */
1148 if (!expression_context_block
)
1149 expression_context_block
= get_selected_block (&expression_context_pc
);
1151 expression_context_pc
= BLOCK_ENTRY_PC (expression_context_block
);
1153 expression_context_pc
= pc
;
1155 /* Fall back to using the current source static context, if any. */
1157 if (!expression_context_block
)
1159 struct symtab_and_line cursal
= get_current_source_symtab_and_line ();
1161 expression_context_block
1162 = BLOCKVECTOR_BLOCK (SYMTAB_BLOCKVECTOR (cursal
.symtab
),
1164 if (expression_context_block
)
1165 expression_context_pc
= BLOCK_ENTRY_PC (expression_context_block
);
1168 if (language_mode
== language_mode_auto
&& block
!= NULL
)
1170 /* Find the language associated to the given context block.
1171 Default to the current language if it can not be determined.
1173 Note that using the language corresponding to the current frame
1174 can sometimes give unexpected results. For instance, this
1175 routine is often called several times during the inferior
1176 startup phase to re-parse breakpoint expressions after
1177 a new shared library has been loaded. The language associated
1178 to the current frame at this moment is not relevant for
1179 the breakpoint. Using it would therefore be silly, so it seems
1180 better to rely on the current language rather than relying on
1181 the current frame language to parse the expression. That's why
1182 we do the following language detection only if the context block
1183 has been specifically provided. */
1184 struct symbol
*func
= block_linkage_function (block
);
1187 lang
= language_def (SYMBOL_LANGUAGE (func
));
1188 if (lang
== NULL
|| lang
->la_language
== language_unknown
)
1189 lang
= current_language
;
1192 lang
= current_language
;
1194 /* get_current_arch may reset CURRENT_LANGUAGE via select_frame.
1195 While we need CURRENT_LANGUAGE to be set to LANG (for lookup_symbol
1196 and others called from *.y) ensure CURRENT_LANGUAGE gets restored
1197 to the value matching SELECTED_FRAME as set by get_current_arch. */
1199 parser_state
ps (10, lang
, get_current_arch ());
1201 scoped_restore_current_language lang_saver
;
1202 set_language (lang
->la_language
);
1206 lang
->la_parser (&ps
);
1208 CATCH (except
, RETURN_MASK_ALL
)
1210 /* If parsing for completion, allow this to succeed; but if no
1211 expression elements have been written, then there's nothing
1213 if (! parse_completion
|| ps
.expout_ptr
== 0)
1214 throw_exception (except
);
1218 /* We have to operate on an "expression *", due to la_post_parser,
1219 which explains this funny-looking double release. */
1220 expression_up result
= ps
.release ();
1222 /* Convert expression from postfix form as generated by yacc
1223 parser, to a prefix form. */
1225 if (expressiondebug
)
1226 dump_raw_expression (result
.get (), gdb_stdlog
,
1227 "before conversion to prefix form");
1229 subexp
= prefixify_expression (result
.get ());
1231 *out_subexp
= subexp
;
1233 lang
->la_post_parser (&result
, void_context_p
);
1235 if (expressiondebug
)
1236 dump_prefix_expression (result
.get (), gdb_stdlog
);
1238 *stringptr
= lexptr
;
1242 /* Parse STRING as an expression, and complain if this fails
1243 to use up all of the contents of STRING. */
1246 parse_expression (const char *string
)
1248 expression_up exp
= parse_exp_1 (&string
, 0, 0, 0);
1250 error (_("Junk after end of expression."));
1254 /* Same as parse_expression, but using the given language (LANG)
1255 to parse the expression. */
1258 parse_expression_with_language (const char *string
, enum language lang
)
1260 gdb::optional
<scoped_restore_current_language
> lang_saver
;
1261 if (current_language
->la_language
!= lang
)
1263 lang_saver
.emplace ();
1264 set_language (lang
);
1267 return parse_expression (string
);
1270 /* Parse STRING as an expression. If parsing ends in the middle of a
1271 field reference, return the type of the left-hand-side of the
1272 reference; furthermore, if the parsing ends in the field name,
1273 return the field name in *NAME. If the parsing ends in the middle
1274 of a field reference, but the reference is somehow invalid, throw
1275 an exception. In all other cases, return NULL. */
1278 parse_expression_for_completion (const char *string
,
1279 gdb::unique_xmalloc_ptr
<char> *name
,
1280 enum type_code
*code
)
1288 parse_completion
= 1;
1289 exp
= parse_exp_in_context (&string
, 0, 0, 0, 0, &subexp
);
1291 CATCH (except
, RETURN_MASK_ERROR
)
1293 /* Nothing, EXP remains NULL. */
1297 parse_completion
= 0;
1301 if (expout_tag_completion_type
!= TYPE_CODE_UNDEF
)
1303 *code
= expout_tag_completion_type
;
1304 *name
= std::move (expout_completion_name
);
1308 if (expout_last_struct
== -1)
1311 const char *fieldname
= extract_field_op (exp
.get (), &subexp
);
1312 if (fieldname
== NULL
)
1318 name
->reset (xstrdup (fieldname
));
1319 /* This might throw an exception. If so, we want to let it
1321 val
= evaluate_subexpression_type (exp
.get (), subexp
);
1323 return value_type (val
);
1326 /* A post-parser that does nothing. */
1329 null_post_parser (expression_up
*exp
, int void_context_p
)
1333 /* Parse floating point value P of length LEN.
1334 Return false if invalid, true if valid.
1335 The successfully parsed number is stored in DATA in
1336 target format for floating-point type TYPE.
1338 NOTE: This accepts the floating point syntax that sscanf accepts. */
1341 parse_float (const char *p
, int len
,
1342 const struct type
*type
, gdb_byte
*data
)
1344 return target_float_from_string (data
, type
, std::string (p
, len
));
1347 /* Stuff for maintaining a stack of types. Currently just used by C, but
1348 probably useful for any language which declares its types "backwards". */
1350 /* A helper function for insert_type and insert_type_address_space.
1351 This does work of expanding the type stack and inserting the new
1352 element, ELEMENT, into the stack at location SLOT. */
1355 insert_into_type_stack (int slot
, union type_stack_elt element
)
1357 gdb_assert (slot
<= type_stack
.elements
.size ());
1358 type_stack
.elements
.insert (type_stack
.elements
.begin () + slot
, element
);
1361 /* Insert a new type, TP, at the bottom of the type stack. If TP is
1362 tp_pointer, tp_reference or tp_rvalue_reference, it is inserted at the
1363 bottom. If TP is a qualifier, it is inserted at slot 1 (just above a
1364 previous tp_pointer) if there is anything on the stack, or simply pushed
1365 if the stack is empty. Other values for TP are invalid. */
1368 insert_type (enum type_pieces tp
)
1370 union type_stack_elt element
;
1373 gdb_assert (tp
== tp_pointer
|| tp
== tp_reference
1374 || tp
== tp_rvalue_reference
|| tp
== tp_const
1375 || tp
== tp_volatile
);
1377 /* If there is anything on the stack (we know it will be a
1378 tp_pointer), insert the qualifier above it. Otherwise, simply
1379 push this on the top of the stack. */
1380 if (!type_stack
.elements
.empty () && (tp
== tp_const
|| tp
== tp_volatile
))
1386 insert_into_type_stack (slot
, element
);
1390 push_type (enum type_pieces tp
)
1394 type_stack
.elements
.push_back (elt
);
1398 push_type_int (int n
)
1402 type_stack
.elements
.push_back (elt
);
1405 /* Insert a tp_space_identifier and the corresponding address space
1406 value into the stack. STRING is the name of an address space, as
1407 recognized by address_space_name_to_int. If the stack is empty,
1408 the new elements are simply pushed. If the stack is not empty,
1409 this function assumes that the first item on the stack is a
1410 tp_pointer, and the new values are inserted above the first
1414 insert_type_address_space (struct parser_state
*pstate
, char *string
)
1416 union type_stack_elt element
;
1419 /* If there is anything on the stack (we know it will be a
1420 tp_pointer), insert the address space qualifier above it.
1421 Otherwise, simply push this on the top of the stack. */
1422 if (!type_stack
.elements
.empty ())
1427 element
.piece
= tp_space_identifier
;
1428 insert_into_type_stack (slot
, element
);
1429 element
.int_val
= address_space_name_to_int (parse_gdbarch (pstate
),
1431 insert_into_type_stack (slot
, element
);
1437 if (!type_stack
.elements
.empty ())
1439 type_stack_elt elt
= type_stack
.elements
.back ();
1440 type_stack
.elements
.pop_back ();
1449 if (!type_stack
.elements
.empty ())
1451 type_stack_elt elt
= type_stack
.elements
.back ();
1452 type_stack
.elements
.pop_back ();
1455 /* "Can't happen". */
1459 /* Pop a type list element from the global type stack. */
1461 static std::vector
<struct type
*> *
1464 gdb_assert (!type_stack
.elements
.empty ());
1465 type_stack_elt elt
= type_stack
.elements
.back ();
1466 type_stack
.elements
.pop_back ();
1467 return elt
.typelist_val
;
1470 /* Pop a type_stack element from the global type stack. */
1472 static struct type_stack
*
1473 pop_type_stack (void)
1475 gdb_assert (!type_stack
.elements
.empty ());
1476 type_stack_elt elt
= type_stack
.elements
.back ();
1477 type_stack
.elements
.pop_back ();
1478 return elt
.stack_val
;
1481 /* Append the elements of the type stack FROM to the type stack TO.
1482 Always returns TO. */
1485 append_type_stack (struct type_stack
*to
, struct type_stack
*from
)
1487 to
->elements
.insert (to
->elements
.end (), from
->elements
.begin (),
1488 from
->elements
.end ());
1492 /* Push the type stack STACK as an element on the global type stack. */
1495 push_type_stack (struct type_stack
*stack
)
1498 elt
.stack_val
= stack
;
1499 type_stack
.elements
.push_back (elt
);
1500 push_type (tp_type_stack
);
1503 /* Copy the global type stack into a newly allocated type stack and
1504 return it. The global stack is cleared. The returned type stack
1505 must be freed with delete. */
1508 get_type_stack (void)
1510 struct type_stack
*result
= new struct type_stack (std::move (type_stack
));
1511 type_stack
.elements
.clear ();
1515 /* Push a function type with arguments onto the global type stack.
1516 LIST holds the argument types. If the final item in LIST is NULL,
1517 then the function will be varargs. */
1520 push_typelist (std::vector
<struct type
*> *list
)
1523 elt
.typelist_val
= list
;
1524 type_stack
.elements
.push_back (elt
);
1525 push_type (tp_function_with_arguments
);
1528 /* Pop the type stack and return a type_instance_flags that
1529 corresponds the const/volatile qualifiers on the stack. This is
1530 called by the C++ parser when parsing methods types, and as such no
1531 other kind of type in the type stack is expected. */
1534 follow_type_instance_flags ()
1536 type_instance_flags flags
= 0;
1539 switch (pop_type ())
1544 flags
|= TYPE_INSTANCE_FLAG_CONST
;
1547 flags
|= TYPE_INSTANCE_FLAG_VOLATILE
;
1550 gdb_assert_not_reached ("unrecognized tp_ value in follow_types");
1555 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1556 as modified by all the stuff on the stack. */
1558 follow_types (struct type
*follow_type
)
1562 int make_volatile
= 0;
1563 int make_addr_space
= 0;
1567 switch (pop_type ())
1572 follow_type
= make_cv_type (make_const
,
1573 TYPE_VOLATILE (follow_type
),
1576 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1579 if (make_addr_space
)
1580 follow_type
= make_type_with_address_space (follow_type
,
1582 make_const
= make_volatile
= 0;
1583 make_addr_space
= 0;
1591 case tp_space_identifier
:
1592 make_addr_space
= pop_type_int ();
1595 follow_type
= lookup_pointer_type (follow_type
);
1597 follow_type
= make_cv_type (make_const
,
1598 TYPE_VOLATILE (follow_type
),
1601 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1604 if (make_addr_space
)
1605 follow_type
= make_type_with_address_space (follow_type
,
1607 make_const
= make_volatile
= 0;
1608 make_addr_space
= 0;
1611 follow_type
= lookup_lvalue_reference_type (follow_type
);
1612 goto process_reference
;
1613 case tp_rvalue_reference
:
1614 follow_type
= lookup_rvalue_reference_type (follow_type
);
1617 follow_type
= make_cv_type (make_const
,
1618 TYPE_VOLATILE (follow_type
),
1621 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1624 if (make_addr_space
)
1625 follow_type
= make_type_with_address_space (follow_type
,
1627 make_const
= make_volatile
= 0;
1628 make_addr_space
= 0;
1631 array_size
= pop_type_int ();
1632 /* FIXME-type-allocation: need a way to free this type when we are
1635 lookup_array_range_type (follow_type
,
1636 0, array_size
>= 0 ? array_size
- 1 : 0);
1638 TYPE_HIGH_BOUND_KIND (TYPE_INDEX_TYPE (follow_type
))
1642 /* FIXME-type-allocation: need a way to free this type when we are
1644 follow_type
= lookup_function_type (follow_type
);
1647 case tp_function_with_arguments
:
1649 std::vector
<struct type
*> *args
= pop_typelist ();
1652 = lookup_function_type_with_arguments (follow_type
,
1660 struct type_stack
*stack
= pop_type_stack ();
1661 /* Sort of ugly, but not really much worse than the
1663 struct type_stack save
= type_stack
;
1665 type_stack
= *stack
;
1666 follow_type
= follow_types (follow_type
);
1667 gdb_assert (type_stack
.elements
.empty ());
1673 gdb_assert_not_reached ("unrecognized tp_ value in follow_types");
1678 /* This function avoids direct calls to fprintf
1679 in the parser generated debug code. */
1681 parser_fprintf (FILE *x
, const char *y
, ...)
1687 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1690 fprintf_unfiltered (gdb_stderr
, " Unknown FILE used.\n");
1691 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1696 /* Implementation of the exp_descriptor method operator_check. */
1699 operator_check_standard (struct expression
*exp
, int pos
,
1700 int (*objfile_func
) (struct objfile
*objfile
,
1704 const union exp_element
*const elts
= exp
->elts
;
1705 struct type
*type
= NULL
;
1706 struct objfile
*objfile
= NULL
;
1708 /* Extended operators should have been already handled by exp_descriptor
1709 iterate method of its specific language. */
1710 gdb_assert (elts
[pos
].opcode
< OP_EXTENDED0
);
1712 /* Track the callers of write_exp_elt_type for this table. */
1714 switch (elts
[pos
].opcode
)
1726 type
= elts
[pos
+ 1].type
;
1731 LONGEST arg
, nargs
= elts
[pos
+ 2].longconst
;
1733 for (arg
= 0; arg
< nargs
; arg
++)
1735 struct type
*inst_type
= elts
[pos
+ 3 + arg
].type
;
1736 struct objfile
*inst_objfile
= TYPE_OBJFILE (inst_type
);
1738 if (inst_objfile
&& (*objfile_func
) (inst_objfile
, data
))
1746 const struct block
*const block
= elts
[pos
+ 1].block
;
1747 const struct symbol
*const symbol
= elts
[pos
+ 2].symbol
;
1749 /* Check objfile where the variable itself is placed.
1750 SYMBOL_OBJ_SECTION (symbol) may be NULL. */
1751 if ((*objfile_func
) (symbol_objfile (symbol
), data
))
1754 /* Check objfile where is placed the code touching the variable. */
1755 objfile
= lookup_objfile_from_block (block
);
1757 type
= SYMBOL_TYPE (symbol
);
1760 case OP_VAR_MSYM_VALUE
:
1761 objfile
= elts
[pos
+ 1].objfile
;
1765 /* Invoke callbacks for TYPE and OBJFILE if they were set as non-NULL. */
1767 if (type
&& TYPE_OBJFILE (type
)
1768 && (*objfile_func
) (TYPE_OBJFILE (type
), data
))
1770 if (objfile
&& (*objfile_func
) (objfile
, data
))
1776 /* Call OBJFILE_FUNC for any objfile found being referenced by EXP.
1777 OBJFILE_FUNC is never called with NULL OBJFILE. OBJFILE_FUNC get
1778 passed an arbitrary caller supplied DATA pointer. If OBJFILE_FUNC
1779 returns non-zero value then (any other) non-zero value is immediately
1780 returned to the caller. Otherwise zero is returned after iterating
1781 through whole EXP. */
1784 exp_iterate (struct expression
*exp
,
1785 int (*objfile_func
) (struct objfile
*objfile
, void *data
),
1790 for (endpos
= exp
->nelts
; endpos
> 0; )
1792 int pos
, args
, oplen
= 0;
1794 operator_length (exp
, endpos
, &oplen
, &args
);
1795 gdb_assert (oplen
> 0);
1797 pos
= endpos
- oplen
;
1798 if (exp
->language_defn
->la_exp_desc
->operator_check (exp
, pos
,
1799 objfile_func
, data
))
1808 /* Helper for exp_uses_objfile. */
1811 exp_uses_objfile_iter (struct objfile
*exp_objfile
, void *objfile_voidp
)
1813 struct objfile
*objfile
= (struct objfile
*) objfile_voidp
;
1815 if (exp_objfile
->separate_debug_objfile_backlink
)
1816 exp_objfile
= exp_objfile
->separate_debug_objfile_backlink
;
1818 return exp_objfile
== objfile
;
1821 /* Return 1 if EXP uses OBJFILE (and will become dangling when OBJFILE
1822 is unloaded), otherwise return 0. OBJFILE must not be a separate debug info
1826 exp_uses_objfile (struct expression
*exp
, struct objfile
*objfile
)
1828 gdb_assert (objfile
->separate_debug_objfile_backlink
== NULL
);
1830 return exp_iterate (exp
, exp_uses_objfile_iter
, objfile
);
1833 /* See definition in parser-defs.h. */
1836 increase_expout_size (struct parser_state
*ps
, size_t lenelt
)
1838 if ((ps
->expout_ptr
+ lenelt
) >= ps
->expout_size
)
1840 ps
->expout_size
= std::max (ps
->expout_size
* 2,
1841 ps
->expout_ptr
+ lenelt
+ 10);
1842 ps
->expout
.reset (XRESIZEVAR (expression
,
1843 ps
->expout
.release (),
1844 (sizeof (struct expression
)
1845 + EXP_ELEM_TO_BYTES (ps
->expout_size
))));
1850 _initialize_parse (void)
1852 add_setshow_zuinteger_cmd ("expression", class_maintenance
,
1854 _("Set expression debugging."),
1855 _("Show expression debugging."),
1856 _("When non-zero, the internal representation "
1857 "of expressions will be printed."),
1859 show_expressiondebug
,
1860 &setdebuglist
, &showdebuglist
);
1861 add_setshow_boolean_cmd ("parser", class_maintenance
,
1863 _("Set parser debugging."),
1864 _("Show parser debugging."),
1865 _("When non-zero, expression parser "
1866 "tracing will be enabled."),
1869 &setdebuglist
, &showdebuglist
);