1 /* Parse expressions for GDB.
3 Copyright (C) 1986, 1989-2001, 2004-2005, 2007-2012 Free Software
6 Modified from expread.y by the Department of Computer Science at the
7 State University of New York at Buffalo, 1991.
9 This file is part of GDB.
11 This program is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 3 of the License, or
14 (at your option) any later version.
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
21 You should have received a copy of the GNU General Public License
22 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 /* Parse an expression from text in a string,
25 and return the result as a struct expression pointer.
26 That structure contains arithmetic operations in reverse polish,
27 with constants represented by operations that are followed by special data.
28 See expression.h for the details of the format.
29 What is important here is that it can be built up sequentially
30 during the process of parsing; the lower levels of the tree always
31 come first in the result. */
35 #include "arch-utils.h"
36 #include "gdb_string.h"
40 #include "expression.h"
45 #include "parser-defs.h"
47 #include "symfile.h" /* for overlay functions */
50 #include "gdb_assert.h"
54 #include "exceptions.h"
55 #include "user-regs.h"
57 /* Standard set of definitions for printing, dumping, prefixifying,
58 * and evaluating expressions. */
60 const struct exp_descriptor exp_descriptor_standard
=
62 print_subexp_standard
,
63 operator_length_standard
,
64 operator_check_standard
,
66 dump_subexp_body_standard
,
67 evaluate_subexp_standard
70 /* Global variables declared in parser-defs.h (and commented there). */
71 struct expression
*expout
;
74 const struct block
*expression_context_block
;
75 CORE_ADDR expression_context_pc
;
76 const struct block
*innermost_block
;
78 static struct type_stack type_stack
;
84 /* True if parsing an expression to attempt completion. */
87 /* The index of the last struct expression directly before a '.' or
88 '->'. This is set when parsing and is only used when completing a
89 field name. It is -1 if no dereference operation was found. */
90 static int expout_last_struct
= -1;
92 static unsigned int expressiondebug
= 0;
94 show_expressiondebug (struct ui_file
*file
, int from_tty
,
95 struct cmd_list_element
*c
, const char *value
)
97 fprintf_filtered (file
, _("Expression debugging is %s.\n"), value
);
101 /* Non-zero if an expression parser should set yydebug. */
105 show_parserdebug (struct ui_file
*file
, int from_tty
,
106 struct cmd_list_element
*c
, const char *value
)
108 fprintf_filtered (file
, _("Parser debugging is %s.\n"), value
);
112 static void free_funcalls (void *ignore
);
114 static int prefixify_subexp (struct expression
*, struct expression
*, int,
117 static struct expression
*parse_exp_in_context (char **, CORE_ADDR
,
118 const struct block
*, int,
121 void _initialize_parse (void);
123 /* Data structure for saving values of arglist_len for function calls whose
124 arguments contain other function calls. */
128 struct funcall
*next
;
132 static struct funcall
*funcall_chain
;
134 /* Begin counting arguments for a function call,
135 saving the data about any containing call. */
142 new = (struct funcall
*) xmalloc (sizeof (struct funcall
));
143 new->next
= funcall_chain
;
144 new->arglist_len
= arglist_len
;
149 /* Return the number of arguments in a function call just terminated,
150 and restore the data for the containing function call. */
155 int val
= arglist_len
;
156 struct funcall
*call
= funcall_chain
;
158 funcall_chain
= call
->next
;
159 arglist_len
= call
->arglist_len
;
164 /* Free everything in the funcall chain.
165 Used when there is an error inside parsing. */
168 free_funcalls (void *ignore
)
170 struct funcall
*call
, *next
;
172 for (call
= funcall_chain
; call
; call
= next
)
179 /* This page contains the functions for adding data to the struct expression
180 being constructed. */
182 /* See definition in parser-defs.h. */
185 initialize_expout (int initial_size
, const struct language_defn
*lang
,
186 struct gdbarch
*gdbarch
)
188 expout_size
= initial_size
;
190 expout
= xmalloc (sizeof (struct expression
)
191 + EXP_ELEM_TO_BYTES (expout_size
));
192 expout
->language_defn
= lang
;
193 expout
->gdbarch
= gdbarch
;
196 /* See definition in parser-defs.h. */
199 reallocate_expout (void)
201 /* Record the actual number of expression elements, and then
202 reallocate the expression memory so that we free up any
205 expout
->nelts
= expout_ptr
;
206 expout
= xrealloc ((char *) expout
,
207 sizeof (struct expression
)
208 + EXP_ELEM_TO_BYTES (expout_ptr
));
211 /* Add one element to the end of the expression. */
213 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
214 a register through here. */
217 write_exp_elt (const union exp_element
*expelt
)
219 if (expout_ptr
>= expout_size
)
222 expout
= (struct expression
*)
223 xrealloc ((char *) expout
, sizeof (struct expression
)
224 + EXP_ELEM_TO_BYTES (expout_size
));
226 expout
->elts
[expout_ptr
++] = *expelt
;
230 write_exp_elt_opcode (enum exp_opcode expelt
)
232 union exp_element tmp
;
234 memset (&tmp
, 0, sizeof (union exp_element
));
236 write_exp_elt (&tmp
);
240 write_exp_elt_sym (struct symbol
*expelt
)
242 union exp_element tmp
;
244 memset (&tmp
, 0, sizeof (union exp_element
));
246 write_exp_elt (&tmp
);
250 write_exp_elt_block (const struct block
*b
)
252 union exp_element tmp
;
254 memset (&tmp
, 0, sizeof (union exp_element
));
256 write_exp_elt (&tmp
);
260 write_exp_elt_objfile (struct objfile
*objfile
)
262 union exp_element tmp
;
264 memset (&tmp
, 0, sizeof (union exp_element
));
265 tmp
.objfile
= objfile
;
266 write_exp_elt (&tmp
);
270 write_exp_elt_longcst (LONGEST expelt
)
272 union exp_element tmp
;
274 memset (&tmp
, 0, sizeof (union exp_element
));
275 tmp
.longconst
= expelt
;
276 write_exp_elt (&tmp
);
280 write_exp_elt_dblcst (DOUBLEST expelt
)
282 union exp_element tmp
;
284 memset (&tmp
, 0, sizeof (union exp_element
));
285 tmp
.doubleconst
= expelt
;
286 write_exp_elt (&tmp
);
290 write_exp_elt_decfloatcst (gdb_byte expelt
[16])
292 union exp_element tmp
;
295 for (index
= 0; index
< 16; index
++)
296 tmp
.decfloatconst
[index
] = expelt
[index
];
298 write_exp_elt (&tmp
);
302 write_exp_elt_type (struct type
*expelt
)
304 union exp_element tmp
;
306 memset (&tmp
, 0, sizeof (union exp_element
));
308 write_exp_elt (&tmp
);
312 write_exp_elt_intern (struct internalvar
*expelt
)
314 union exp_element tmp
;
316 memset (&tmp
, 0, sizeof (union exp_element
));
317 tmp
.internalvar
= expelt
;
318 write_exp_elt (&tmp
);
321 /* Add a string constant to the end of the expression.
323 String constants are stored by first writing an expression element
324 that contains the length of the string, then stuffing the string
325 constant itself into however many expression elements are needed
326 to hold it, and then writing another expression element that contains
327 the length of the string. I.e. an expression element at each end of
328 the string records the string length, so you can skip over the
329 expression elements containing the actual string bytes from either
330 end of the string. Note that this also allows gdb to handle
331 strings with embedded null bytes, as is required for some languages.
333 Don't be fooled by the fact that the string is null byte terminated,
334 this is strictly for the convenience of debugging gdb itself.
335 Gdb does not depend up the string being null terminated, since the
336 actual length is recorded in expression elements at each end of the
337 string. The null byte is taken into consideration when computing how
338 many expression elements are required to hold the string constant, of
343 write_exp_string (struct stoken str
)
345 int len
= str
.length
;
349 /* Compute the number of expression elements required to hold the string
350 (including a null byte terminator), along with one expression element
351 at each end to record the actual string length (not including the
352 null byte terminator). */
354 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
+ 1);
356 /* Ensure that we have enough available expression elements to store
359 if ((expout_ptr
+ lenelt
) >= expout_size
)
361 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
362 expout
= (struct expression
*)
363 xrealloc ((char *) expout
, (sizeof (struct expression
)
364 + EXP_ELEM_TO_BYTES (expout_size
)));
367 /* Write the leading length expression element (which advances the current
368 expression element index), then write the string constant followed by a
369 terminating null byte, and then write the trailing length expression
372 write_exp_elt_longcst ((LONGEST
) len
);
373 strdata
= (char *) &expout
->elts
[expout_ptr
];
374 memcpy (strdata
, str
.ptr
, len
);
375 *(strdata
+ len
) = '\0';
376 expout_ptr
+= lenelt
- 2;
377 write_exp_elt_longcst ((LONGEST
) len
);
380 /* Add a vector of string constants to the end of the expression.
382 This adds an OP_STRING operation, but encodes the contents
383 differently from write_exp_string. The language is expected to
384 handle evaluation of this expression itself.
386 After the usual OP_STRING header, TYPE is written into the
387 expression as a long constant. The interpretation of this field is
388 up to the language evaluator.
390 Next, each string in VEC is written. The length is written as a
391 long constant, followed by the contents of the string. */
394 write_exp_string_vector (int type
, struct stoken_vector
*vec
)
398 /* Compute the size. We compute the size in number of slots to
399 avoid issues with string padding. */
401 for (i
= 0; i
< vec
->len
; ++i
)
403 /* One slot for the length of this element, plus the number of
404 slots needed for this string. */
405 n_slots
+= 1 + BYTES_TO_EXP_ELEM (vec
->tokens
[i
].length
);
408 /* One more slot for the type of the string. */
411 /* Now compute a phony string length. */
412 len
= EXP_ELEM_TO_BYTES (n_slots
) - 1;
415 if ((expout_ptr
+ n_slots
) >= expout_size
)
417 expout_size
= max (expout_size
* 2, expout_ptr
+ n_slots
+ 10);
418 expout
= (struct expression
*)
419 xrealloc ((char *) expout
, (sizeof (struct expression
)
420 + EXP_ELEM_TO_BYTES (expout_size
)));
423 write_exp_elt_opcode (OP_STRING
);
424 write_exp_elt_longcst (len
);
425 write_exp_elt_longcst (type
);
427 for (i
= 0; i
< vec
->len
; ++i
)
429 write_exp_elt_longcst (vec
->tokens
[i
].length
);
430 memcpy (&expout
->elts
[expout_ptr
], vec
->tokens
[i
].ptr
,
431 vec
->tokens
[i
].length
);
432 expout_ptr
+= BYTES_TO_EXP_ELEM (vec
->tokens
[i
].length
);
435 write_exp_elt_longcst (len
);
436 write_exp_elt_opcode (OP_STRING
);
439 /* Add a bitstring constant to the end of the expression.
441 Bitstring constants are stored by first writing an expression element
442 that contains the length of the bitstring (in bits), then stuffing the
443 bitstring constant itself into however many expression elements are
444 needed to hold it, and then writing another expression element that
445 contains the length of the bitstring. I.e. an expression element at
446 each end of the bitstring records the bitstring length, so you can skip
447 over the expression elements containing the actual bitstring bytes from
448 either end of the bitstring. */
451 write_exp_bitstring (struct stoken str
)
453 int bits
= str
.length
; /* length in bits */
454 int len
= (bits
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
458 /* Compute the number of expression elements required to hold the bitstring,
459 along with one expression element at each end to record the actual
460 bitstring length in bits. */
462 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
);
464 /* Ensure that we have enough available expression elements to store
467 if ((expout_ptr
+ lenelt
) >= expout_size
)
469 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
470 expout
= (struct expression
*)
471 xrealloc ((char *) expout
, (sizeof (struct expression
)
472 + EXP_ELEM_TO_BYTES (expout_size
)));
475 /* Write the leading length expression element (which advances the current
476 expression element index), then write the bitstring constant, and then
477 write the trailing length expression element. */
479 write_exp_elt_longcst ((LONGEST
) bits
);
480 strdata
= (char *) &expout
->elts
[expout_ptr
];
481 memcpy (strdata
, str
.ptr
, len
);
482 expout_ptr
+= lenelt
- 2;
483 write_exp_elt_longcst ((LONGEST
) bits
);
486 /* Add the appropriate elements for a minimal symbol to the end of
490 write_exp_msymbol (struct minimal_symbol
*msymbol
)
492 struct objfile
*objfile
= msymbol_objfile (msymbol
);
493 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
495 CORE_ADDR addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
496 struct obj_section
*section
= SYMBOL_OBJ_SECTION (msymbol
);
497 enum minimal_symbol_type type
= MSYMBOL_TYPE (msymbol
);
500 /* The minimal symbol might point to a function descriptor;
501 resolve it to the actual code address instead. */
502 pc
= gdbarch_convert_from_func_ptr_addr (gdbarch
, addr
, ¤t_target
);
505 struct minimal_symbol
*ifunc_msym
= lookup_minimal_symbol_by_pc (pc
);
507 /* In this case, assume we have a code symbol instead of
510 if (ifunc_msym
!= NULL
&& MSYMBOL_TYPE (ifunc_msym
) == mst_text_gnu_ifunc
511 && SYMBOL_VALUE_ADDRESS (ifunc_msym
) == pc
)
513 /* A function descriptor has been resolved but PC is still in the
514 STT_GNU_IFUNC resolver body (such as because inferior does not
515 run to be able to call it). */
517 type
= mst_text_gnu_ifunc
;
525 if (overlay_debugging
)
526 addr
= symbol_overlayed_address (addr
, section
);
528 write_exp_elt_opcode (OP_LONG
);
529 /* Let's make the type big enough to hold a 64-bit address. */
530 write_exp_elt_type (objfile_type (objfile
)->builtin_core_addr
);
531 write_exp_elt_longcst ((LONGEST
) addr
);
532 write_exp_elt_opcode (OP_LONG
);
534 if (section
&& section
->the_bfd_section
->flags
& SEC_THREAD_LOCAL
)
536 write_exp_elt_opcode (UNOP_MEMVAL_TLS
);
537 write_exp_elt_objfile (objfile
);
538 write_exp_elt_type (objfile_type (objfile
)->nodebug_tls_symbol
);
539 write_exp_elt_opcode (UNOP_MEMVAL_TLS
);
543 write_exp_elt_opcode (UNOP_MEMVAL
);
548 case mst_solib_trampoline
:
549 write_exp_elt_type (objfile_type (objfile
)->nodebug_text_symbol
);
552 case mst_text_gnu_ifunc
:
553 write_exp_elt_type (objfile_type (objfile
)
554 ->nodebug_text_gnu_ifunc_symbol
);
561 write_exp_elt_type (objfile_type (objfile
)->nodebug_data_symbol
);
564 case mst_slot_got_plt
:
565 write_exp_elt_type (objfile_type (objfile
)->nodebug_got_plt_symbol
);
569 write_exp_elt_type (objfile_type (objfile
)->nodebug_unknown_symbol
);
572 write_exp_elt_opcode (UNOP_MEMVAL
);
575 /* Mark the current index as the starting location of a structure
576 expression. This is used when completing on field names. */
579 mark_struct_expression (void)
581 expout_last_struct
= expout_ptr
;
585 /* Recognize tokens that start with '$'. These include:
587 $regname A native register name or a "standard
590 $variable A convenience variable with a name chosen
593 $digits Value history with index <digits>, starting
594 from the first value which has index 1.
596 $$digits Value history with index <digits> relative
597 to the last value. I.e. $$0 is the last
598 value, $$1 is the one previous to that, $$2
599 is the one previous to $$1, etc.
601 $ | $0 | $$0 The last value in the value history.
603 $$ An abbreviation for the second to the last
604 value in the value history, I.e. $$1 */
607 write_dollar_variable (struct stoken str
)
609 struct symbol
*sym
= NULL
;
610 struct minimal_symbol
*msym
= NULL
;
611 struct internalvar
*isym
= NULL
;
613 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
614 and $$digits (equivalent to $<-digits> if you could type that). */
618 /* Double dollar means negate the number and add -1 as well.
619 Thus $$ alone means -1. */
620 if (str
.length
>= 2 && str
.ptr
[1] == '$')
627 /* Just dollars (one or two). */
631 /* Is the rest of the token digits? */
632 for (; i
< str
.length
; i
++)
633 if (!(str
.ptr
[i
] >= '0' && str
.ptr
[i
] <= '9'))
637 i
= atoi (str
.ptr
+ 1 + negate
);
643 /* Handle tokens that refer to machine registers:
644 $ followed by a register name. */
645 i
= user_reg_map_name_to_regnum (parse_gdbarch
,
646 str
.ptr
+ 1, str
.length
- 1);
648 goto handle_register
;
650 /* Any names starting with $ are probably debugger internal variables. */
652 isym
= lookup_only_internalvar (copy_name (str
) + 1);
655 write_exp_elt_opcode (OP_INTERNALVAR
);
656 write_exp_elt_intern (isym
);
657 write_exp_elt_opcode (OP_INTERNALVAR
);
661 /* On some systems, such as HP-UX and hppa-linux, certain system routines
662 have names beginning with $ or $$. Check for those, first. */
664 sym
= lookup_symbol (copy_name (str
), (struct block
*) NULL
,
665 VAR_DOMAIN
, (int *) NULL
);
668 write_exp_elt_opcode (OP_VAR_VALUE
);
669 write_exp_elt_block (block_found
); /* set by lookup_symbol */
670 write_exp_elt_sym (sym
);
671 write_exp_elt_opcode (OP_VAR_VALUE
);
674 msym
= lookup_minimal_symbol (copy_name (str
), NULL
, NULL
);
677 write_exp_msymbol (msym
);
681 /* Any other names are assumed to be debugger internal variables. */
683 write_exp_elt_opcode (OP_INTERNALVAR
);
684 write_exp_elt_intern (create_internalvar (copy_name (str
) + 1));
685 write_exp_elt_opcode (OP_INTERNALVAR
);
688 write_exp_elt_opcode (OP_LAST
);
689 write_exp_elt_longcst ((LONGEST
) i
);
690 write_exp_elt_opcode (OP_LAST
);
693 write_exp_elt_opcode (OP_REGISTER
);
696 write_exp_string (str
);
697 write_exp_elt_opcode (OP_REGISTER
);
703 find_template_name_end (char *p
)
706 int just_seen_right
= 0;
707 int just_seen_colon
= 0;
708 int just_seen_space
= 0;
710 if (!p
|| (*p
!= '<'))
721 /* In future, may want to allow these?? */
724 depth
++; /* start nested template */
725 if (just_seen_colon
|| just_seen_right
|| just_seen_space
)
726 return 0; /* but not after : or :: or > or space */
729 if (just_seen_colon
|| just_seen_right
)
730 return 0; /* end a (nested?) template */
731 just_seen_right
= 1; /* but not after : or :: */
732 if (--depth
== 0) /* also disallow >>, insist on > > */
733 return ++p
; /* if outermost ended, return */
736 if (just_seen_space
|| (just_seen_colon
> 1))
737 return 0; /* nested class spec coming up */
738 just_seen_colon
++; /* we allow :: but not :::: */
743 if (!((*p
>= 'a' && *p
<= 'z') || /* allow token chars */
744 (*p
>= 'A' && *p
<= 'Z') ||
745 (*p
>= '0' && *p
<= '9') ||
746 (*p
== '_') || (*p
== ',') || /* commas for template args */
747 (*p
== '&') || (*p
== '*') || /* pointer and ref types */
748 (*p
== '(') || (*p
== ')') || /* function types */
749 (*p
== '[') || (*p
== ']'))) /* array types */
763 /* Return a null-terminated temporary copy of the name of a string token.
765 Tokens that refer to names do so with explicit pointer and length,
766 so they can share the storage that lexptr is parsing.
767 When it is necessary to pass a name to a function that expects
768 a null-terminated string, the substring is copied out
769 into a separate block of storage.
771 N.B. A single buffer is reused on each call. */
774 copy_name (struct stoken token
)
776 /* A temporary buffer for identifiers, so we can null-terminate them.
777 We allocate this with xrealloc. parse_exp_1 used to allocate with
778 alloca, using the size of the whole expression as a conservative
779 estimate of the space needed. However, macro expansion can
780 introduce names longer than the original expression; there's no
781 practical way to know beforehand how large that might be. */
782 static char *namecopy
;
783 static size_t namecopy_size
;
785 /* Make sure there's enough space for the token. */
786 if (namecopy_size
< token
.length
+ 1)
788 namecopy_size
= token
.length
+ 1;
789 namecopy
= xrealloc (namecopy
, token
.length
+ 1);
792 memcpy (namecopy
, token
.ptr
, token
.length
);
793 namecopy
[token
.length
] = 0;
799 /* See comments on parser-defs.h. */
802 prefixify_expression (struct expression
*expr
)
804 int len
= sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expr
->nelts
);
805 struct expression
*temp
;
806 int inpos
= expr
->nelts
, outpos
= 0;
808 temp
= (struct expression
*) alloca (len
);
810 /* Copy the original expression into temp. */
811 memcpy (temp
, expr
, len
);
813 return prefixify_subexp (temp
, expr
, inpos
, outpos
);
816 /* Return the number of exp_elements in the postfix subexpression
817 of EXPR whose operator is at index ENDPOS - 1 in EXPR. */
820 length_of_subexp (struct expression
*expr
, int endpos
)
824 operator_length (expr
, endpos
, &oplen
, &args
);
828 oplen
+= length_of_subexp (expr
, endpos
- oplen
);
835 /* Sets *OPLENP to the length of the operator whose (last) index is
836 ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
840 operator_length (const struct expression
*expr
, int endpos
, int *oplenp
,
843 expr
->language_defn
->la_exp_desc
->operator_length (expr
, endpos
,
847 /* Default value for operator_length in exp_descriptor vectors. */
850 operator_length_standard (const struct expression
*expr
, int endpos
,
851 int *oplenp
, int *argsp
)
855 enum f90_range_type range_type
;
859 error (_("?error in operator_length_standard"));
861 i
= (int) expr
->elts
[endpos
- 1].opcode
;
867 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
868 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
882 case OP_VAR_ENTRY_VALUE
:
892 case OP_F77_UNDETERMINED_ARGLIST
:
894 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
898 oplen
= 4 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
902 case OP_OBJC_MSGCALL
: /* Objective C message (method) call. */
904 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
913 case UNOP_DYNAMIC_CAST
:
914 case UNOP_REINTERPRET_CAST
:
915 case UNOP_MEMVAL_TYPE
:
927 case UNOP_MEMVAL_TLS
:
947 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
948 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
953 case STRUCTOP_STRUCT
:
960 case OP_OBJC_NSSTRING
: /* Objective C Foundation Class
961 NSString constant. */
962 case OP_OBJC_SELECTOR
: /* Objective C "@selector" pseudo-op. */
964 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
965 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
970 args
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
971 args
-= longest_to_int (expr
->elts
[endpos
- 3].longconst
);
981 case MULTI_SUBSCRIPT
:
983 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
986 case BINOP_ASSIGN_MODIFY
:
999 range_type
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
1002 case LOW_BOUND_DEFAULT
:
1003 case HIGH_BOUND_DEFAULT
:
1006 case BOTH_BOUND_DEFAULT
:
1009 case NONE_BOUND_DEFAULT
:
1017 args
= 1 + (i
< (int) BINOP_END
);
1024 /* Copy the subexpression ending just before index INEND in INEXPR
1025 into OUTEXPR, starting at index OUTBEG.
1026 In the process, convert it from suffix to prefix form.
1027 If EXPOUT_LAST_STRUCT is -1, then this function always returns -1.
1028 Otherwise, it returns the index of the subexpression which is the
1029 left-hand-side of the expression at EXPOUT_LAST_STRUCT. */
1032 prefixify_subexp (struct expression
*inexpr
,
1033 struct expression
*outexpr
, int inend
, int outbeg
)
1041 operator_length (inexpr
, inend
, &oplen
, &args
);
1043 /* Copy the final operator itself, from the end of the input
1044 to the beginning of the output. */
1046 memcpy (&outexpr
->elts
[outbeg
], &inexpr
->elts
[inend
],
1047 EXP_ELEM_TO_BYTES (oplen
));
1050 if (expout_last_struct
== inend
)
1051 result
= outbeg
- oplen
;
1053 /* Find the lengths of the arg subexpressions. */
1054 arglens
= (int *) alloca (args
* sizeof (int));
1055 for (i
= args
- 1; i
>= 0; i
--)
1057 oplen
= length_of_subexp (inexpr
, inend
);
1062 /* Now copy each subexpression, preserving the order of
1063 the subexpressions, but prefixifying each one.
1064 In this loop, inend starts at the beginning of
1065 the expression this level is working on
1066 and marches forward over the arguments.
1067 outbeg does similarly in the output. */
1068 for (i
= 0; i
< args
; i
++)
1074 r
= prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
);
1077 /* Return immediately. We probably have only parsed a
1078 partial expression, so we don't want to try to reverse
1079 the other operands. */
1088 /* Read an expression from the string *STRINGPTR points to,
1089 parse it, and return a pointer to a struct expression that we malloc.
1090 Use block BLOCK as the lexical context for variable names;
1091 if BLOCK is zero, use the block of the selected stack frame.
1092 Meanwhile, advance *STRINGPTR to point after the expression,
1093 at the first nonwhite character that is not part of the expression
1094 (possibly a null character).
1096 If COMMA is nonzero, stop if a comma is reached. */
1099 parse_exp_1 (char **stringptr
, CORE_ADDR pc
, const struct block
*block
,
1102 return parse_exp_in_context (stringptr
, pc
, block
, comma
, 0, NULL
);
1105 /* As for parse_exp_1, except that if VOID_CONTEXT_P, then
1106 no value is expected from the expression.
1107 OUT_SUBEXP is set when attempting to complete a field name; in this
1108 case it is set to the index of the subexpression on the
1109 left-hand-side of the struct op. If not doing such completion, it
1110 is left untouched. */
1112 static struct expression
*
1113 parse_exp_in_context (char **stringptr
, CORE_ADDR pc
, const struct block
*block
,
1114 int comma
, int void_context_p
, int *out_subexp
)
1116 volatile struct gdb_exception except
;
1117 struct cleanup
*old_chain
;
1118 const struct language_defn
*lang
= NULL
;
1121 lexptr
= *stringptr
;
1125 type_stack
.depth
= 0;
1126 expout_last_struct
= -1;
1128 comma_terminates
= comma
;
1130 if (lexptr
== 0 || *lexptr
== 0)
1131 error_no_arg (_("expression to compute"));
1133 old_chain
= make_cleanup (free_funcalls
, 0 /*ignore*/);
1136 expression_context_block
= block
;
1138 /* If no context specified, try using the current frame, if any. */
1139 if (!expression_context_block
)
1140 expression_context_block
= get_selected_block (&expression_context_pc
);
1142 expression_context_pc
= BLOCK_START (expression_context_block
);
1144 expression_context_pc
= pc
;
1146 /* Fall back to using the current source static context, if any. */
1148 if (!expression_context_block
)
1150 struct symtab_and_line cursal
= get_current_source_symtab_and_line ();
1152 expression_context_block
1153 = BLOCKVECTOR_BLOCK (BLOCKVECTOR (cursal
.symtab
), STATIC_BLOCK
);
1154 if (expression_context_block
)
1155 expression_context_pc
= BLOCK_START (expression_context_block
);
1158 if (language_mode
== language_mode_auto
&& block
!= NULL
)
1160 /* Find the language associated to the given context block.
1161 Default to the current language if it can not be determined.
1163 Note that using the language corresponding to the current frame
1164 can sometimes give unexpected results. For instance, this
1165 routine is often called several times during the inferior
1166 startup phase to re-parse breakpoint expressions after
1167 a new shared library has been loaded. The language associated
1168 to the current frame at this moment is not relevant for
1169 the breakpoint. Using it would therefore be silly, so it seems
1170 better to rely on the current language rather than relying on
1171 the current frame language to parse the expression. That's why
1172 we do the following language detection only if the context block
1173 has been specifically provided. */
1174 struct symbol
*func
= block_linkage_function (block
);
1177 lang
= language_def (SYMBOL_LANGUAGE (func
));
1178 if (lang
== NULL
|| lang
->la_language
== language_unknown
)
1179 lang
= current_language
;
1182 lang
= current_language
;
1184 initialize_expout (10, lang
, get_current_arch ());
1186 TRY_CATCH (except
, RETURN_MASK_ALL
)
1188 if (lang
->la_parser ())
1189 lang
->la_error (NULL
);
1191 if (except
.reason
< 0)
1193 if (! parse_completion
)
1196 throw_exception (except
);
1200 discard_cleanups (old_chain
);
1202 reallocate_expout ();
1204 /* Convert expression from postfix form as generated by yacc
1205 parser, to a prefix form. */
1207 if (expressiondebug
)
1208 dump_raw_expression (expout
, gdb_stdlog
,
1209 "before conversion to prefix form");
1211 subexp
= prefixify_expression (expout
);
1213 *out_subexp
= subexp
;
1215 lang
->la_post_parser (&expout
, void_context_p
);
1217 if (expressiondebug
)
1218 dump_prefix_expression (expout
, gdb_stdlog
);
1220 *stringptr
= lexptr
;
1224 /* Parse STRING as an expression, and complain if this fails
1225 to use up all of the contents of STRING. */
1228 parse_expression (char *string
)
1230 struct expression
*exp
;
1232 exp
= parse_exp_1 (&string
, 0, 0, 0);
1234 error (_("Junk after end of expression."));
1238 /* Parse STRING as an expression. If parsing ends in the middle of a
1239 field reference, return the type of the left-hand-side of the
1240 reference; furthermore, if the parsing ends in the field name,
1241 return the field name in *NAME. If the parsing ends in the middle
1242 of a field reference, but the reference is somehow invalid, throw
1243 an exception. In all other cases, return NULL. Returned non-NULL
1244 *NAME must be freed by the caller. */
1247 parse_expression_for_completion (char *string
, char **name
)
1249 struct expression
*exp
= NULL
;
1252 volatile struct gdb_exception except
;
1254 TRY_CATCH (except
, RETURN_MASK_ERROR
)
1256 parse_completion
= 1;
1257 exp
= parse_exp_in_context (&string
, 0, 0, 0, 0, &subexp
);
1259 parse_completion
= 0;
1260 if (except
.reason
< 0 || ! exp
)
1262 if (expout_last_struct
== -1)
1268 *name
= extract_field_op (exp
, &subexp
);
1275 /* This might throw an exception. If so, we want to let it
1277 val
= evaluate_subexpression_type (exp
, subexp
);
1278 /* (*NAME) is a part of the EXP memory block freed below. */
1279 *name
= xstrdup (*name
);
1282 return value_type (val
);
1285 /* A post-parser that does nothing. */
1288 null_post_parser (struct expression
**exp
, int void_context_p
)
1292 /* Parse floating point value P of length LEN.
1293 Return 0 (false) if invalid, 1 (true) if valid.
1294 The successfully parsed number is stored in D.
1295 *SUFFIX points to the suffix of the number in P.
1297 NOTE: This accepts the floating point syntax that sscanf accepts. */
1300 parse_float (const char *p
, int len
, DOUBLEST
*d
, const char **suffix
)
1305 copy
= xmalloc (len
+ 1);
1306 memcpy (copy
, p
, len
);
1309 num
= sscanf (copy
, "%" DOUBLEST_SCAN_FORMAT
"%n", d
, &n
);
1312 /* The sscanf man page suggests not making any assumptions on the effect
1313 of %n on the result, so we don't.
1314 That is why we simply test num == 0. */
1322 /* Parse floating point value P of length LEN, using the C syntax for floats.
1323 Return 0 (false) if invalid, 1 (true) if valid.
1324 The successfully parsed number is stored in *D.
1325 Its type is taken from builtin_type (gdbarch) and is stored in *T. */
1328 parse_c_float (struct gdbarch
*gdbarch
, const char *p
, int len
,
1329 DOUBLEST
*d
, struct type
**t
)
1333 const struct builtin_type
*builtin_types
= builtin_type (gdbarch
);
1335 if (! parse_float (p
, len
, d
, &suffix
))
1338 suffix_len
= p
+ len
- suffix
;
1340 if (suffix_len
== 0)
1341 *t
= builtin_types
->builtin_double
;
1342 else if (suffix_len
== 1)
1344 /* Handle suffixes: 'f' for float, 'l' for long double. */
1345 if (tolower (*suffix
) == 'f')
1346 *t
= builtin_types
->builtin_float
;
1347 else if (tolower (*suffix
) == 'l')
1348 *t
= builtin_types
->builtin_long_double
;
1358 /* Stuff for maintaining a stack of types. Currently just used by C, but
1359 probably useful for any language which declares its types "backwards". */
1361 /* Ensure that there are HOWMUCH open slots on the type stack STACK. */
1364 type_stack_reserve (struct type_stack
*stack
, int howmuch
)
1366 if (stack
->depth
+ howmuch
>= stack
->size
)
1369 if (stack
->size
< howmuch
)
1370 stack
->size
= howmuch
;
1371 stack
->elements
= xrealloc (stack
->elements
,
1372 stack
->size
* sizeof (union type_stack_elt
));
1376 /* Ensure that there is a single open slot in the global type stack. */
1379 check_type_stack_depth (void)
1381 type_stack_reserve (&type_stack
, 1);
1384 /* A helper function for insert_type and insert_type_address_space.
1385 This does work of expanding the type stack and inserting the new
1386 element, ELEMENT, into the stack at location SLOT. */
1389 insert_into_type_stack (int slot
, union type_stack_elt element
)
1391 check_type_stack_depth ();
1393 if (slot
< type_stack
.depth
)
1394 memmove (&type_stack
.elements
[slot
+ 1], &type_stack
.elements
[slot
],
1395 (type_stack
.depth
- slot
) * sizeof (union type_stack_elt
));
1396 type_stack
.elements
[slot
] = element
;
1400 /* Insert a new type, TP, at the bottom of the type stack. If TP is
1401 tp_pointer or tp_reference, it is inserted at the bottom. If TP is
1402 a qualifier, it is inserted at slot 1 (just above a previous
1403 tp_pointer) if there is anything on the stack, or simply pushed if
1404 the stack is empty. Other values for TP are invalid. */
1407 insert_type (enum type_pieces tp
)
1409 union type_stack_elt element
;
1412 gdb_assert (tp
== tp_pointer
|| tp
== tp_reference
1413 || tp
== tp_const
|| tp
== tp_volatile
);
1415 /* If there is anything on the stack (we know it will be a
1416 tp_pointer), insert the qualifier above it. Otherwise, simply
1417 push this on the top of the stack. */
1418 if (type_stack
.depth
&& (tp
== tp_const
|| tp
== tp_volatile
))
1424 insert_into_type_stack (slot
, element
);
1428 push_type (enum type_pieces tp
)
1430 check_type_stack_depth ();
1431 type_stack
.elements
[type_stack
.depth
++].piece
= tp
;
1435 push_type_int (int n
)
1437 check_type_stack_depth ();
1438 type_stack
.elements
[type_stack
.depth
++].int_val
= n
;
1441 /* Insert a tp_space_identifier and the corresponding address space
1442 value into the stack. STRING is the name of an address space, as
1443 recognized by address_space_name_to_int. If the stack is empty,
1444 the new elements are simply pushed. If the stack is not empty,
1445 this function assumes that the first item on the stack is a
1446 tp_pointer, and the new values are inserted above the first
1450 insert_type_address_space (char *string
)
1452 union type_stack_elt element
;
1455 /* If there is anything on the stack (we know it will be a
1456 tp_pointer), insert the address space qualifier above it.
1457 Otherwise, simply push this on the top of the stack. */
1458 if (type_stack
.depth
)
1463 element
.piece
= tp_space_identifier
;
1464 insert_into_type_stack (slot
, element
);
1465 element
.int_val
= address_space_name_to_int (parse_gdbarch
, string
);
1466 insert_into_type_stack (slot
, element
);
1472 if (type_stack
.depth
)
1473 return type_stack
.elements
[--type_stack
.depth
].piece
;
1480 if (type_stack
.depth
)
1481 return type_stack
.elements
[--type_stack
.depth
].int_val
;
1482 /* "Can't happen". */
1486 /* Pop a type list element from the global type stack. */
1488 static VEC (type_ptr
) *
1491 gdb_assert (type_stack
.depth
);
1492 return type_stack
.elements
[--type_stack
.depth
].typelist_val
;
1495 /* Pop a type_stack element from the global type stack. */
1497 static struct type_stack
*
1498 pop_type_stack (void)
1500 gdb_assert (type_stack
.depth
);
1501 return type_stack
.elements
[--type_stack
.depth
].stack_val
;
1504 /* Append the elements of the type stack FROM to the type stack TO.
1505 Always returns TO. */
1508 append_type_stack (struct type_stack
*to
, struct type_stack
*from
)
1510 type_stack_reserve (to
, from
->depth
);
1512 memcpy (&to
->elements
[to
->depth
], &from
->elements
[0],
1513 from
->depth
* sizeof (union type_stack_elt
));
1514 to
->depth
+= from
->depth
;
1519 /* Push the type stack STACK as an element on the global type stack. */
1522 push_type_stack (struct type_stack
*stack
)
1524 check_type_stack_depth ();
1525 type_stack
.elements
[type_stack
.depth
++].stack_val
= stack
;
1526 push_type (tp_type_stack
);
1529 /* Copy the global type stack into a newly allocated type stack and
1530 return it. The global stack is cleared. The returned type stack
1531 must be freed with type_stack_cleanup. */
1534 get_type_stack (void)
1536 struct type_stack
*result
= XNEW (struct type_stack
);
1538 *result
= type_stack
;
1539 type_stack
.depth
= 0;
1540 type_stack
.size
= 0;
1541 type_stack
.elements
= NULL
;
1546 /* A cleanup function that destroys a single type stack. */
1549 type_stack_cleanup (void *arg
)
1551 struct type_stack
*stack
= arg
;
1553 xfree (stack
->elements
);
1557 /* Push a function type with arguments onto the global type stack.
1558 LIST holds the argument types. If the final item in LIST is NULL,
1559 then the function will be varargs. */
1562 push_typelist (VEC (type_ptr
) *list
)
1564 check_type_stack_depth ();
1565 type_stack
.elements
[type_stack
.depth
++].typelist_val
= list
;
1566 push_type (tp_function_with_arguments
);
1569 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1570 as modified by all the stuff on the stack. */
1572 follow_types (struct type
*follow_type
)
1576 int make_volatile
= 0;
1577 int make_addr_space
= 0;
1581 switch (pop_type ())
1586 follow_type
= make_cv_type (make_const
,
1587 TYPE_VOLATILE (follow_type
),
1590 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1593 if (make_addr_space
)
1594 follow_type
= make_type_with_address_space (follow_type
,
1596 make_const
= make_volatile
= 0;
1597 make_addr_space
= 0;
1605 case tp_space_identifier
:
1606 make_addr_space
= pop_type_int ();
1609 follow_type
= lookup_pointer_type (follow_type
);
1611 follow_type
= make_cv_type (make_const
,
1612 TYPE_VOLATILE (follow_type
),
1615 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1618 if (make_addr_space
)
1619 follow_type
= make_type_with_address_space (follow_type
,
1621 make_const
= make_volatile
= 0;
1622 make_addr_space
= 0;
1625 follow_type
= lookup_reference_type (follow_type
);
1627 follow_type
= make_cv_type (make_const
,
1628 TYPE_VOLATILE (follow_type
),
1631 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1634 if (make_addr_space
)
1635 follow_type
= make_type_with_address_space (follow_type
,
1637 make_const
= make_volatile
= 0;
1638 make_addr_space
= 0;
1641 array_size
= pop_type_int ();
1642 /* FIXME-type-allocation: need a way to free this type when we are
1645 lookup_array_range_type (follow_type
,
1646 0, array_size
>= 0 ? array_size
- 1 : 0);
1648 TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (follow_type
) = 1;
1651 /* FIXME-type-allocation: need a way to free this type when we are
1653 follow_type
= lookup_function_type (follow_type
);
1656 case tp_function_with_arguments
:
1658 VEC (type_ptr
) *args
= pop_typelist ();
1661 = lookup_function_type_with_arguments (follow_type
,
1662 VEC_length (type_ptr
, args
),
1663 VEC_address (type_ptr
,
1665 VEC_free (type_ptr
, args
);
1671 struct type_stack
*stack
= pop_type_stack ();
1672 /* Sort of ugly, but not really much worse than the
1674 struct type_stack save
= type_stack
;
1676 type_stack
= *stack
;
1677 follow_type
= follow_types (follow_type
);
1678 gdb_assert (type_stack
.depth
== 0);
1684 gdb_assert_not_reached ("unrecognized tp_ value in follow_types");
1689 /* This function avoids direct calls to fprintf
1690 in the parser generated debug code. */
1692 parser_fprintf (FILE *x
, const char *y
, ...)
1698 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1701 fprintf_unfiltered (gdb_stderr
, " Unknown FILE used.\n");
1702 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1707 /* Implementation of the exp_descriptor method operator_check. */
1710 operator_check_standard (struct expression
*exp
, int pos
,
1711 int (*objfile_func
) (struct objfile
*objfile
,
1715 const union exp_element
*const elts
= exp
->elts
;
1716 struct type
*type
= NULL
;
1717 struct objfile
*objfile
= NULL
;
1719 /* Extended operators should have been already handled by exp_descriptor
1720 iterate method of its specific language. */
1721 gdb_assert (elts
[pos
].opcode
< OP_EXTENDED0
);
1723 /* Track the callers of write_exp_elt_type for this table. */
1725 switch (elts
[pos
].opcode
)
1738 type
= elts
[pos
+ 1].type
;
1743 LONGEST arg
, nargs
= elts
[pos
+ 1].longconst
;
1745 for (arg
= 0; arg
< nargs
; arg
++)
1747 struct type
*type
= elts
[pos
+ 2 + arg
].type
;
1748 struct objfile
*objfile
= TYPE_OBJFILE (type
);
1750 if (objfile
&& (*objfile_func
) (objfile
, data
))
1756 case UNOP_MEMVAL_TLS
:
1757 objfile
= elts
[pos
+ 1].objfile
;
1758 type
= elts
[pos
+ 2].type
;
1763 const struct block
*const block
= elts
[pos
+ 1].block
;
1764 const struct symbol
*const symbol
= elts
[pos
+ 2].symbol
;
1766 /* Check objfile where the variable itself is placed.
1767 SYMBOL_OBJ_SECTION (symbol) may be NULL. */
1768 if ((*objfile_func
) (SYMBOL_SYMTAB (symbol
)->objfile
, data
))
1771 /* Check objfile where is placed the code touching the variable. */
1772 objfile
= lookup_objfile_from_block (block
);
1774 type
= SYMBOL_TYPE (symbol
);
1779 /* Invoke callbacks for TYPE and OBJFILE if they were set as non-NULL. */
1781 if (type
&& TYPE_OBJFILE (type
)
1782 && (*objfile_func
) (TYPE_OBJFILE (type
), data
))
1784 if (objfile
&& (*objfile_func
) (objfile
, data
))
1790 /* Call OBJFILE_FUNC for any TYPE and OBJFILE found being referenced by EXP.
1791 The functions are never called with NULL OBJFILE. Functions get passed an
1792 arbitrary caller supplied DATA pointer. If any of the functions returns
1793 non-zero value then (any other) non-zero value is immediately returned to
1794 the caller. Otherwise zero is returned after iterating through whole EXP.
1798 exp_iterate (struct expression
*exp
,
1799 int (*objfile_func
) (struct objfile
*objfile
, void *data
),
1804 for (endpos
= exp
->nelts
; endpos
> 0; )
1806 int pos
, args
, oplen
= 0;
1808 operator_length (exp
, endpos
, &oplen
, &args
);
1809 gdb_assert (oplen
> 0);
1811 pos
= endpos
- oplen
;
1812 if (exp
->language_defn
->la_exp_desc
->operator_check (exp
, pos
,
1813 objfile_func
, data
))
1822 /* Helper for exp_uses_objfile. */
1825 exp_uses_objfile_iter (struct objfile
*exp_objfile
, void *objfile_voidp
)
1827 struct objfile
*objfile
= objfile_voidp
;
1829 if (exp_objfile
->separate_debug_objfile_backlink
)
1830 exp_objfile
= exp_objfile
->separate_debug_objfile_backlink
;
1832 return exp_objfile
== objfile
;
1835 /* Return 1 if EXP uses OBJFILE (and will become dangling when OBJFILE
1836 is unloaded), otherwise return 0. OBJFILE must not be a separate debug info
1840 exp_uses_objfile (struct expression
*exp
, struct objfile
*objfile
)
1842 gdb_assert (objfile
->separate_debug_objfile_backlink
== NULL
);
1844 return exp_iterate (exp
, exp_uses_objfile_iter
, objfile
);
1848 _initialize_parse (void)
1850 type_stack
.size
= 0;
1851 type_stack
.depth
= 0;
1852 type_stack
.elements
= NULL
;
1854 add_setshow_zuinteger_cmd ("expression", class_maintenance
,
1856 _("Set expression debugging."),
1857 _("Show expression debugging."),
1858 _("When non-zero, the internal representation "
1859 "of expressions will be printed."),
1861 show_expressiondebug
,
1862 &setdebuglist
, &showdebuglist
);
1863 add_setshow_boolean_cmd ("parser", class_maintenance
,
1865 _("Set parser debugging."),
1866 _("Show parser debugging."),
1867 _("When non-zero, expression parser "
1868 "tracing will be enabled."),
1871 &setdebuglist
, &showdebuglist
);