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 struct block
*expression_context_block
;
75 CORE_ADDR expression_context_pc
;
76 struct block
*innermost_block
;
78 union type_stack_elt
*type_stack
;
79 int type_stack_depth
, type_stack_size
;
85 /* True if parsing an expression to find a field reference. This is
86 only used by completion. */
89 /* The index of the last struct expression directly before a '.' or
90 '->'. This is set when parsing and is only used when completing a
91 field name. It is -1 if no dereference operation was found. */
92 static int expout_last_struct
= -1;
94 static int expressiondebug
= 0;
96 show_expressiondebug (struct ui_file
*file
, int from_tty
,
97 struct cmd_list_element
*c
, const char *value
)
99 fprintf_filtered (file
, _("Expression debugging is %s.\n"), value
);
103 /* Non-zero if an expression parser should set yydebug. */
107 show_parserdebug (struct ui_file
*file
, int from_tty
,
108 struct cmd_list_element
*c
, const char *value
)
110 fprintf_filtered (file
, _("Parser debugging is %s.\n"), value
);
114 static void free_funcalls (void *ignore
);
116 static int prefixify_expression (struct expression
*);
118 static int prefixify_subexp (struct expression
*, struct expression
*, int,
121 static struct expression
*parse_exp_in_context (char **, struct block
*, int,
124 void _initialize_parse (void);
126 /* Data structure for saving values of arglist_len for function calls whose
127 arguments contain other function calls. */
131 struct funcall
*next
;
135 static struct funcall
*funcall_chain
;
137 /* Begin counting arguments for a function call,
138 saving the data about any containing call. */
145 new = (struct funcall
*) xmalloc (sizeof (struct funcall
));
146 new->next
= funcall_chain
;
147 new->arglist_len
= 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 struct funcall
*call
= funcall_chain
;
161 funcall_chain
= call
->next
;
162 arglist_len
= call
->arglist_len
;
167 /* Free everything in the funcall chain.
168 Used when there is an error inside parsing. */
171 free_funcalls (void *ignore
)
173 struct funcall
*call
, *next
;
175 for (call
= funcall_chain
; call
; call
= next
)
182 /* This page contains the functions for adding data to the struct expression
183 being constructed. */
185 /* Add one element to the end of the expression. */
187 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
188 a register through here. */
191 write_exp_elt (const union exp_element
*expelt
)
193 if (expout_ptr
>= expout_size
)
196 expout
= (struct expression
*)
197 xrealloc ((char *) expout
, sizeof (struct expression
)
198 + EXP_ELEM_TO_BYTES (expout_size
));
200 expout
->elts
[expout_ptr
++] = *expelt
;
204 write_exp_elt_opcode (enum exp_opcode expelt
)
206 union exp_element tmp
;
208 memset (&tmp
, 0, sizeof (union exp_element
));
210 write_exp_elt (&tmp
);
214 write_exp_elt_sym (struct symbol
*expelt
)
216 union exp_element tmp
;
218 memset (&tmp
, 0, sizeof (union exp_element
));
220 write_exp_elt (&tmp
);
224 write_exp_elt_block (struct block
*b
)
226 union exp_element tmp
;
228 memset (&tmp
, 0, sizeof (union exp_element
));
230 write_exp_elt (&tmp
);
234 write_exp_elt_objfile (struct objfile
*objfile
)
236 union exp_element tmp
;
238 memset (&tmp
, 0, sizeof (union exp_element
));
239 tmp
.objfile
= objfile
;
240 write_exp_elt (&tmp
);
244 write_exp_elt_longcst (LONGEST expelt
)
246 union exp_element tmp
;
248 memset (&tmp
, 0, sizeof (union exp_element
));
249 tmp
.longconst
= expelt
;
250 write_exp_elt (&tmp
);
254 write_exp_elt_dblcst (DOUBLEST expelt
)
256 union exp_element tmp
;
258 memset (&tmp
, 0, sizeof (union exp_element
));
259 tmp
.doubleconst
= expelt
;
260 write_exp_elt (&tmp
);
264 write_exp_elt_decfloatcst (gdb_byte expelt
[16])
266 union exp_element tmp
;
269 for (index
= 0; index
< 16; index
++)
270 tmp
.decfloatconst
[index
] = expelt
[index
];
272 write_exp_elt (&tmp
);
276 write_exp_elt_type (struct type
*expelt
)
278 union exp_element tmp
;
280 memset (&tmp
, 0, sizeof (union exp_element
));
282 write_exp_elt (&tmp
);
286 write_exp_elt_intern (struct internalvar
*expelt
)
288 union exp_element tmp
;
290 memset (&tmp
, 0, sizeof (union exp_element
));
291 tmp
.internalvar
= expelt
;
292 write_exp_elt (&tmp
);
295 /* Add a string constant to the end of the expression.
297 String constants are stored by first writing an expression element
298 that contains the length of the string, then stuffing the string
299 constant itself into however many expression elements are needed
300 to hold it, and then writing another expression element that contains
301 the length of the string. I.e. an expression element at each end of
302 the string records the string length, so you can skip over the
303 expression elements containing the actual string bytes from either
304 end of the string. Note that this also allows gdb to handle
305 strings with embedded null bytes, as is required for some languages.
307 Don't be fooled by the fact that the string is null byte terminated,
308 this is strictly for the convenience of debugging gdb itself.
309 Gdb does not depend up the string being null terminated, since the
310 actual length is recorded in expression elements at each end of the
311 string. The null byte is taken into consideration when computing how
312 many expression elements are required to hold the string constant, of
317 write_exp_string (struct stoken str
)
319 int len
= str
.length
;
323 /* Compute the number of expression elements required to hold the string
324 (including a null byte terminator), along with one expression element
325 at each end to record the actual string length (not including the
326 null byte terminator). */
328 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
+ 1);
330 /* Ensure that we have enough available expression elements to store
333 if ((expout_ptr
+ lenelt
) >= expout_size
)
335 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
336 expout
= (struct expression
*)
337 xrealloc ((char *) expout
, (sizeof (struct expression
)
338 + EXP_ELEM_TO_BYTES (expout_size
)));
341 /* Write the leading length expression element (which advances the current
342 expression element index), then write the string constant followed by a
343 terminating null byte, and then write the trailing length expression
346 write_exp_elt_longcst ((LONGEST
) len
);
347 strdata
= (char *) &expout
->elts
[expout_ptr
];
348 memcpy (strdata
, str
.ptr
, len
);
349 *(strdata
+ len
) = '\0';
350 expout_ptr
+= lenelt
- 2;
351 write_exp_elt_longcst ((LONGEST
) len
);
354 /* Add a vector of string constants to the end of the expression.
356 This adds an OP_STRING operation, but encodes the contents
357 differently from write_exp_string. The language is expected to
358 handle evaluation of this expression itself.
360 After the usual OP_STRING header, TYPE is written into the
361 expression as a long constant. The interpretation of this field is
362 up to the language evaluator.
364 Next, each string in VEC is written. The length is written as a
365 long constant, followed by the contents of the string. */
368 write_exp_string_vector (int type
, struct stoken_vector
*vec
)
372 /* Compute the size. We compute the size in number of slots to
373 avoid issues with string padding. */
375 for (i
= 0; i
< vec
->len
; ++i
)
377 /* One slot for the length of this element, plus the number of
378 slots needed for this string. */
379 n_slots
+= 1 + BYTES_TO_EXP_ELEM (vec
->tokens
[i
].length
);
382 /* One more slot for the type of the string. */
385 /* Now compute a phony string length. */
386 len
= EXP_ELEM_TO_BYTES (n_slots
) - 1;
389 if ((expout_ptr
+ n_slots
) >= expout_size
)
391 expout_size
= max (expout_size
* 2, expout_ptr
+ n_slots
+ 10);
392 expout
= (struct expression
*)
393 xrealloc ((char *) expout
, (sizeof (struct expression
)
394 + EXP_ELEM_TO_BYTES (expout_size
)));
397 write_exp_elt_opcode (OP_STRING
);
398 write_exp_elt_longcst (len
);
399 write_exp_elt_longcst (type
);
401 for (i
= 0; i
< vec
->len
; ++i
)
403 write_exp_elt_longcst (vec
->tokens
[i
].length
);
404 memcpy (&expout
->elts
[expout_ptr
], vec
->tokens
[i
].ptr
,
405 vec
->tokens
[i
].length
);
406 expout_ptr
+= BYTES_TO_EXP_ELEM (vec
->tokens
[i
].length
);
409 write_exp_elt_longcst (len
);
410 write_exp_elt_opcode (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 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 /* Ensure that we have enough available expression elements to store
441 if ((expout_ptr
+ lenelt
) >= expout_size
)
443 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
444 expout
= (struct expression
*)
445 xrealloc ((char *) expout
, (sizeof (struct expression
)
446 + EXP_ELEM_TO_BYTES (expout_size
)));
449 /* Write the leading length expression element (which advances the current
450 expression element index), then write the bitstring constant, and then
451 write the trailing length expression element. */
453 write_exp_elt_longcst ((LONGEST
) bits
);
454 strdata
= (char *) &expout
->elts
[expout_ptr
];
455 memcpy (strdata
, str
.ptr
, len
);
456 expout_ptr
+= lenelt
- 2;
457 write_exp_elt_longcst ((LONGEST
) bits
);
460 /* Add the appropriate elements for a minimal symbol to the end of
464 write_exp_msymbol (struct minimal_symbol
*msymbol
)
466 struct objfile
*objfile
= msymbol_objfile (msymbol
);
467 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
469 CORE_ADDR addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
470 struct obj_section
*section
= SYMBOL_OBJ_SECTION (msymbol
);
471 enum minimal_symbol_type type
= MSYMBOL_TYPE (msymbol
);
474 /* The minimal symbol might point to a function descriptor;
475 resolve it to the actual code address instead. */
476 pc
= gdbarch_convert_from_func_ptr_addr (gdbarch
, addr
, ¤t_target
);
479 struct minimal_symbol
*ifunc_msym
= lookup_minimal_symbol_by_pc (pc
);
481 /* In this case, assume we have a code symbol instead of
484 if (ifunc_msym
!= NULL
&& MSYMBOL_TYPE (ifunc_msym
) == mst_text_gnu_ifunc
485 && SYMBOL_VALUE_ADDRESS (ifunc_msym
) == pc
)
487 /* A function descriptor has been resolved but PC is still in the
488 STT_GNU_IFUNC resolver body (such as because inferior does not
489 run to be able to call it). */
491 type
= mst_text_gnu_ifunc
;
499 if (overlay_debugging
)
500 addr
= symbol_overlayed_address (addr
, section
);
502 write_exp_elt_opcode (OP_LONG
);
503 /* Let's make the type big enough to hold a 64-bit address. */
504 write_exp_elt_type (objfile_type (objfile
)->builtin_core_addr
);
505 write_exp_elt_longcst ((LONGEST
) addr
);
506 write_exp_elt_opcode (OP_LONG
);
508 if (section
&& section
->the_bfd_section
->flags
& SEC_THREAD_LOCAL
)
510 write_exp_elt_opcode (UNOP_MEMVAL_TLS
);
511 write_exp_elt_objfile (objfile
);
512 write_exp_elt_type (objfile_type (objfile
)->nodebug_tls_symbol
);
513 write_exp_elt_opcode (UNOP_MEMVAL_TLS
);
517 write_exp_elt_opcode (UNOP_MEMVAL
);
522 case mst_solib_trampoline
:
523 write_exp_elt_type (objfile_type (objfile
)->nodebug_text_symbol
);
526 case mst_text_gnu_ifunc
:
527 write_exp_elt_type (objfile_type (objfile
)
528 ->nodebug_text_gnu_ifunc_symbol
);
535 write_exp_elt_type (objfile_type (objfile
)->nodebug_data_symbol
);
538 case mst_slot_got_plt
:
539 write_exp_elt_type (objfile_type (objfile
)->nodebug_got_plt_symbol
);
543 write_exp_elt_type (objfile_type (objfile
)->nodebug_unknown_symbol
);
546 write_exp_elt_opcode (UNOP_MEMVAL
);
549 /* Mark the current index as the starting location of a structure
550 expression. This is used when completing on field names. */
553 mark_struct_expression (void)
555 expout_last_struct
= expout_ptr
;
559 /* Recognize tokens that start with '$'. These include:
561 $regname A native register name or a "standard
564 $variable A convenience variable with a name chosen
567 $digits Value history with index <digits>, starting
568 from the first value which has index 1.
570 $$digits Value history with index <digits> relative
571 to the last value. I.e. $$0 is the last
572 value, $$1 is the one previous to that, $$2
573 is the one previous to $$1, etc.
575 $ | $0 | $$0 The last value in the value history.
577 $$ An abbreviation for the second to the last
578 value in the value history, I.e. $$1 */
581 write_dollar_variable (struct stoken str
)
583 struct symbol
*sym
= NULL
;
584 struct minimal_symbol
*msym
= NULL
;
585 struct internalvar
*isym
= NULL
;
587 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
588 and $$digits (equivalent to $<-digits> if you could type that). */
592 /* Double dollar means negate the number and add -1 as well.
593 Thus $$ alone means -1. */
594 if (str
.length
>= 2 && str
.ptr
[1] == '$')
601 /* Just dollars (one or two). */
605 /* Is the rest of the token digits? */
606 for (; i
< str
.length
; i
++)
607 if (!(str
.ptr
[i
] >= '0' && str
.ptr
[i
] <= '9'))
611 i
= atoi (str
.ptr
+ 1 + negate
);
617 /* Handle tokens that refer to machine registers:
618 $ followed by a register name. */
619 i
= user_reg_map_name_to_regnum (parse_gdbarch
,
620 str
.ptr
+ 1, str
.length
- 1);
622 goto handle_register
;
624 /* Any names starting with $ are probably debugger internal variables. */
626 isym
= lookup_only_internalvar (copy_name (str
) + 1);
629 write_exp_elt_opcode (OP_INTERNALVAR
);
630 write_exp_elt_intern (isym
);
631 write_exp_elt_opcode (OP_INTERNALVAR
);
635 /* On some systems, such as HP-UX and hppa-linux, certain system routines
636 have names beginning with $ or $$. Check for those, first. */
638 sym
= lookup_symbol (copy_name (str
), (struct block
*) NULL
,
639 VAR_DOMAIN
, (int *) NULL
);
642 write_exp_elt_opcode (OP_VAR_VALUE
);
643 write_exp_elt_block (block_found
); /* set by lookup_symbol */
644 write_exp_elt_sym (sym
);
645 write_exp_elt_opcode (OP_VAR_VALUE
);
648 msym
= lookup_minimal_symbol (copy_name (str
), NULL
, NULL
);
651 write_exp_msymbol (msym
);
655 /* Any other names are assumed to be debugger internal variables. */
657 write_exp_elt_opcode (OP_INTERNALVAR
);
658 write_exp_elt_intern (create_internalvar (copy_name (str
) + 1));
659 write_exp_elt_opcode (OP_INTERNALVAR
);
662 write_exp_elt_opcode (OP_LAST
);
663 write_exp_elt_longcst ((LONGEST
) i
);
664 write_exp_elt_opcode (OP_LAST
);
667 write_exp_elt_opcode (OP_REGISTER
);
670 write_exp_string (str
);
671 write_exp_elt_opcode (OP_REGISTER
);
677 find_template_name_end (char *p
)
680 int just_seen_right
= 0;
681 int just_seen_colon
= 0;
682 int just_seen_space
= 0;
684 if (!p
|| (*p
!= '<'))
695 /* In future, may want to allow these?? */
698 depth
++; /* start nested template */
699 if (just_seen_colon
|| just_seen_right
|| just_seen_space
)
700 return 0; /* but not after : or :: or > or space */
703 if (just_seen_colon
|| just_seen_right
)
704 return 0; /* end a (nested?) template */
705 just_seen_right
= 1; /* but not after : or :: */
706 if (--depth
== 0) /* also disallow >>, insist on > > */
707 return ++p
; /* if outermost ended, return */
710 if (just_seen_space
|| (just_seen_colon
> 1))
711 return 0; /* nested class spec coming up */
712 just_seen_colon
++; /* we allow :: but not :::: */
717 if (!((*p
>= 'a' && *p
<= 'z') || /* allow token chars */
718 (*p
>= 'A' && *p
<= 'Z') ||
719 (*p
>= '0' && *p
<= '9') ||
720 (*p
== '_') || (*p
== ',') || /* commas for template args */
721 (*p
== '&') || (*p
== '*') || /* pointer and ref types */
722 (*p
== '(') || (*p
== ')') || /* function types */
723 (*p
== '[') || (*p
== ']'))) /* array types */
737 /* Return a null-terminated temporary copy of the name of a string token.
739 Tokens that refer to names do so with explicit pointer and length,
740 so they can share the storage that lexptr is parsing.
741 When it is necessary to pass a name to a function that expects
742 a null-terminated string, the substring is copied out
743 into a separate block of storage.
745 N.B. A single buffer is reused on each call. */
748 copy_name (struct stoken token
)
750 /* A temporary buffer for identifiers, so we can null-terminate them.
751 We allocate this with xrealloc. parse_exp_1 used to allocate with
752 alloca, using the size of the whole expression as a conservative
753 estimate of the space needed. However, macro expansion can
754 introduce names longer than the original expression; there's no
755 practical way to know beforehand how large that might be. */
756 static char *namecopy
;
757 static size_t namecopy_size
;
759 /* Make sure there's enough space for the token. */
760 if (namecopy_size
< token
.length
+ 1)
762 namecopy_size
= token
.length
+ 1;
763 namecopy
= xrealloc (namecopy
, token
.length
+ 1);
766 memcpy (namecopy
, token
.ptr
, token
.length
);
767 namecopy
[token
.length
] = 0;
772 /* Reverse an expression from suffix form (in which it is constructed)
773 to prefix form (in which we can conveniently print or execute it).
774 Ordinarily this always returns -1. However, if EXPOUT_LAST_STRUCT
775 is not -1 (i.e., we are trying to complete a field name), it will
776 return the index of the subexpression which is the left-hand-side
777 of the struct operation at EXPOUT_LAST_STRUCT. */
780 prefixify_expression (struct expression
*expr
)
782 int len
= sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expr
->nelts
);
783 struct expression
*temp
;
784 int inpos
= expr
->nelts
, outpos
= 0;
786 temp
= (struct expression
*) alloca (len
);
788 /* Copy the original expression into temp. */
789 memcpy (temp
, expr
, len
);
791 return prefixify_subexp (temp
, expr
, inpos
, outpos
);
794 /* Return the number of exp_elements in the postfix subexpression
795 of EXPR whose operator is at index ENDPOS - 1 in EXPR. */
798 length_of_subexp (struct expression
*expr
, int endpos
)
802 operator_length (expr
, endpos
, &oplen
, &args
);
806 oplen
+= length_of_subexp (expr
, endpos
- oplen
);
813 /* Sets *OPLENP to the length of the operator whose (last) index is
814 ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
818 operator_length (const struct expression
*expr
, int endpos
, int *oplenp
,
821 expr
->language_defn
->la_exp_desc
->operator_length (expr
, endpos
,
825 /* Default value for operator_length in exp_descriptor vectors. */
828 operator_length_standard (const struct expression
*expr
, int endpos
,
829 int *oplenp
, int *argsp
)
833 enum f90_range_type range_type
;
837 error (_("?error in operator_length_standard"));
839 i
= (int) expr
->elts
[endpos
- 1].opcode
;
845 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
846 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
860 case OP_VAR_ENTRY_VALUE
:
870 case OP_F77_UNDETERMINED_ARGLIST
:
872 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
876 oplen
= 4 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
880 case OP_OBJC_MSGCALL
: /* Objective C message (method) call. */
882 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
892 case UNOP_DYNAMIC_CAST
:
893 case UNOP_REINTERPRET_CAST
:
899 case UNOP_MEMVAL_TLS
:
917 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
918 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
924 case STRUCTOP_STRUCT
:
931 case OP_OBJC_NSSTRING
: /* Objective C Foundation Class
932 NSString constant. */
933 case OP_OBJC_SELECTOR
: /* Objective C "@selector" pseudo-op. */
935 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
936 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
940 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
941 oplen
= (oplen
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
942 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
);
947 args
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
948 args
-= longest_to_int (expr
->elts
[endpos
- 3].longconst
);
954 case TERNOP_SLICE_COUNT
:
959 case MULTI_SUBSCRIPT
:
961 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
964 case BINOP_ASSIGN_MODIFY
:
977 range_type
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
980 case LOW_BOUND_DEFAULT
:
981 case HIGH_BOUND_DEFAULT
:
984 case BOTH_BOUND_DEFAULT
:
987 case NONE_BOUND_DEFAULT
:
995 args
= 1 + (i
< (int) BINOP_END
);
1002 /* Copy the subexpression ending just before index INEND in INEXPR
1003 into OUTEXPR, starting at index OUTBEG.
1004 In the process, convert it from suffix to prefix form.
1005 If EXPOUT_LAST_STRUCT is -1, then this function always returns -1.
1006 Otherwise, it returns the index of the subexpression which is the
1007 left-hand-side of the expression at EXPOUT_LAST_STRUCT. */
1010 prefixify_subexp (struct expression
*inexpr
,
1011 struct expression
*outexpr
, int inend
, int outbeg
)
1019 operator_length (inexpr
, inend
, &oplen
, &args
);
1021 /* Copy the final operator itself, from the end of the input
1022 to the beginning of the output. */
1024 memcpy (&outexpr
->elts
[outbeg
], &inexpr
->elts
[inend
],
1025 EXP_ELEM_TO_BYTES (oplen
));
1028 if (expout_last_struct
== inend
)
1029 result
= outbeg
- oplen
;
1031 /* Find the lengths of the arg subexpressions. */
1032 arglens
= (int *) alloca (args
* sizeof (int));
1033 for (i
= args
- 1; i
>= 0; i
--)
1035 oplen
= length_of_subexp (inexpr
, inend
);
1040 /* Now copy each subexpression, preserving the order of
1041 the subexpressions, but prefixifying each one.
1042 In this loop, inend starts at the beginning of
1043 the expression this level is working on
1044 and marches forward over the arguments.
1045 outbeg does similarly in the output. */
1046 for (i
= 0; i
< args
; i
++)
1052 r
= prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
);
1055 /* Return immediately. We probably have only parsed a
1056 partial expression, so we don't want to try to reverse
1057 the other operands. */
1066 /* Read an expression from the string *STRINGPTR points to,
1067 parse it, and return a pointer to a struct expression that we malloc.
1068 Use block BLOCK as the lexical context for variable names;
1069 if BLOCK is zero, use the block of the selected stack frame.
1070 Meanwhile, advance *STRINGPTR to point after the expression,
1071 at the first nonwhite character that is not part of the expression
1072 (possibly a null character).
1074 If COMMA is nonzero, stop if a comma is reached. */
1077 parse_exp_1 (char **stringptr
, struct block
*block
, int comma
)
1079 return parse_exp_in_context (stringptr
, block
, comma
, 0, NULL
);
1082 /* As for parse_exp_1, except that if VOID_CONTEXT_P, then
1083 no value is expected from the expression.
1084 OUT_SUBEXP is set when attempting to complete a field name; in this
1085 case it is set to the index of the subexpression on the
1086 left-hand-side of the struct op. If not doing such completion, it
1087 is left untouched. */
1089 static struct expression
*
1090 parse_exp_in_context (char **stringptr
, struct block
*block
, int comma
,
1091 int void_context_p
, int *out_subexp
)
1093 volatile struct gdb_exception except
;
1094 struct cleanup
*old_chain
;
1095 const struct language_defn
*lang
= NULL
;
1098 lexptr
= *stringptr
;
1102 type_stack_depth
= 0;
1103 expout_last_struct
= -1;
1105 comma_terminates
= comma
;
1107 if (lexptr
== 0 || *lexptr
== 0)
1108 error_no_arg (_("expression to compute"));
1110 old_chain
= make_cleanup (free_funcalls
, 0 /*ignore*/);
1113 expression_context_block
= block
;
1115 /* If no context specified, try using the current frame, if any. */
1116 if (!expression_context_block
)
1117 expression_context_block
= get_selected_block (&expression_context_pc
);
1119 expression_context_pc
= BLOCK_START (expression_context_block
);
1121 /* Fall back to using the current source static context, if any. */
1123 if (!expression_context_block
)
1125 struct symtab_and_line cursal
= get_current_source_symtab_and_line ();
1127 expression_context_block
1128 = BLOCKVECTOR_BLOCK (BLOCKVECTOR (cursal
.symtab
), STATIC_BLOCK
);
1129 if (expression_context_block
)
1130 expression_context_pc
= BLOCK_START (expression_context_block
);
1133 if (language_mode
== language_mode_auto
&& block
!= NULL
)
1135 /* Find the language associated to the given context block.
1136 Default to the current language if it can not be determined.
1138 Note that using the language corresponding to the current frame
1139 can sometimes give unexpected results. For instance, this
1140 routine is often called several times during the inferior
1141 startup phase to re-parse breakpoint expressions after
1142 a new shared library has been loaded. The language associated
1143 to the current frame at this moment is not relevant for
1144 the breakpoint. Using it would therefore be silly, so it seems
1145 better to rely on the current language rather than relying on
1146 the current frame language to parse the expression. That's why
1147 we do the following language detection only if the context block
1148 has been specifically provided. */
1149 struct symbol
*func
= block_linkage_function (block
);
1152 lang
= language_def (SYMBOL_LANGUAGE (func
));
1153 if (lang
== NULL
|| lang
->la_language
== language_unknown
)
1154 lang
= current_language
;
1157 lang
= current_language
;
1161 expout
= (struct expression
*)
1162 xmalloc (sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_size
));
1163 expout
->language_defn
= lang
;
1164 expout
->gdbarch
= get_current_arch ();
1166 TRY_CATCH (except
, RETURN_MASK_ALL
)
1168 if (lang
->la_parser ())
1169 lang
->la_error (NULL
);
1171 if (except
.reason
< 0)
1173 if (! in_parse_field
)
1176 throw_exception (except
);
1180 discard_cleanups (old_chain
);
1182 /* Record the actual number of expression elements, and then
1183 reallocate the expression memory so that we free up any
1186 expout
->nelts
= expout_ptr
;
1187 expout
= (struct expression
*)
1188 xrealloc ((char *) expout
,
1189 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_ptr
));
1191 /* Convert expression from postfix form as generated by yacc
1192 parser, to a prefix form. */
1194 if (expressiondebug
)
1195 dump_raw_expression (expout
, gdb_stdlog
,
1196 "before conversion to prefix form");
1198 subexp
= prefixify_expression (expout
);
1200 *out_subexp
= subexp
;
1202 lang
->la_post_parser (&expout
, void_context_p
);
1204 if (expressiondebug
)
1205 dump_prefix_expression (expout
, gdb_stdlog
);
1207 *stringptr
= lexptr
;
1211 /* Parse STRING as an expression, and complain if this fails
1212 to use up all of the contents of STRING. */
1215 parse_expression (char *string
)
1217 struct expression
*exp
;
1219 exp
= parse_exp_1 (&string
, 0, 0);
1221 error (_("Junk after end of expression."));
1225 /* Parse STRING as an expression. If parsing ends in the middle of a
1226 field reference, return the type of the left-hand-side of the
1227 reference; furthermore, if the parsing ends in the field name,
1228 return the field name in *NAME. If the parsing ends in the middle
1229 of a field reference, but the reference is somehow invalid, throw
1230 an exception. In all other cases, return NULL. Returned non-NULL
1231 *NAME must be freed by the caller. */
1234 parse_field_expression (char *string
, char **name
)
1236 struct expression
*exp
= NULL
;
1239 volatile struct gdb_exception except
;
1241 TRY_CATCH (except
, RETURN_MASK_ERROR
)
1244 exp
= parse_exp_in_context (&string
, 0, 0, 0, &subexp
);
1247 if (except
.reason
< 0 || ! exp
)
1249 if (expout_last_struct
== -1)
1255 *name
= extract_field_op (exp
, &subexp
);
1262 /* This might throw an exception. If so, we want to let it
1264 val
= evaluate_subexpression_type (exp
, subexp
);
1265 /* (*NAME) is a part of the EXP memory block freed below. */
1266 *name
= xstrdup (*name
);
1269 return value_type (val
);
1272 /* A post-parser that does nothing. */
1275 null_post_parser (struct expression
**exp
, int void_context_p
)
1279 /* Parse floating point value P of length LEN.
1280 Return 0 (false) if invalid, 1 (true) if valid.
1281 The successfully parsed number is stored in D.
1282 *SUFFIX points to the suffix of the number in P.
1284 NOTE: This accepts the floating point syntax that sscanf accepts. */
1287 parse_float (const char *p
, int len
, DOUBLEST
*d
, const char **suffix
)
1293 copy
= xmalloc (len
+ 1);
1294 memcpy (copy
, p
, len
);
1297 num
= sscanf (copy
, "%" DOUBLEST_SCAN_FORMAT
"%n", d
, &n
);
1300 /* The sscanf man page suggests not making any assumptions on the effect
1301 of %n on the result, so we don't.
1302 That is why we simply test num == 0. */
1310 /* Parse floating point value P of length LEN, using the C syntax for floats.
1311 Return 0 (false) if invalid, 1 (true) if valid.
1312 The successfully parsed number is stored in *D.
1313 Its type is taken from builtin_type (gdbarch) and is stored in *T. */
1316 parse_c_float (struct gdbarch
*gdbarch
, const char *p
, int len
,
1317 DOUBLEST
*d
, struct type
**t
)
1321 const struct builtin_type
*builtin_types
= builtin_type (gdbarch
);
1323 if (! parse_float (p
, len
, d
, &suffix
))
1326 suffix_len
= p
+ len
- suffix
;
1328 if (suffix_len
== 0)
1329 *t
= builtin_types
->builtin_double
;
1330 else if (suffix_len
== 1)
1332 /* Handle suffixes: 'f' for float, 'l' for long double. */
1333 if (tolower (*suffix
) == 'f')
1334 *t
= builtin_types
->builtin_float
;
1335 else if (tolower (*suffix
) == 'l')
1336 *t
= builtin_types
->builtin_long_double
;
1346 /* Stuff for maintaining a stack of types. Currently just used by C, but
1347 probably useful for any language which declares its types "backwards". */
1350 check_type_stack_depth (void)
1352 if (type_stack_depth
== type_stack_size
)
1354 type_stack_size
*= 2;
1355 type_stack
= (union type_stack_elt
*)
1356 xrealloc ((char *) type_stack
, type_stack_size
* sizeof (*type_stack
));
1361 push_type (enum type_pieces tp
)
1363 check_type_stack_depth ();
1364 type_stack
[type_stack_depth
++].piece
= tp
;
1368 push_type_int (int n
)
1370 check_type_stack_depth ();
1371 type_stack
[type_stack_depth
++].int_val
= n
;
1375 push_type_address_space (char *string
)
1377 push_type_int (address_space_name_to_int (parse_gdbarch
, string
));
1383 if (type_stack_depth
)
1384 return type_stack
[--type_stack_depth
].piece
;
1391 if (type_stack_depth
)
1392 return type_stack
[--type_stack_depth
].int_val
;
1393 /* "Can't happen". */
1397 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1398 as modified by all the stuff on the stack. */
1400 follow_types (struct type
*follow_type
)
1404 int make_volatile
= 0;
1405 int make_addr_space
= 0;
1409 switch (pop_type ())
1414 follow_type
= make_cv_type (make_const
,
1415 TYPE_VOLATILE (follow_type
),
1418 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1421 if (make_addr_space
)
1422 follow_type
= make_type_with_address_space (follow_type
,
1424 make_const
= make_volatile
= 0;
1425 make_addr_space
= 0;
1433 case tp_space_identifier
:
1434 make_addr_space
= pop_type_int ();
1437 follow_type
= lookup_pointer_type (follow_type
);
1439 follow_type
= make_cv_type (make_const
,
1440 TYPE_VOLATILE (follow_type
),
1443 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1446 if (make_addr_space
)
1447 follow_type
= make_type_with_address_space (follow_type
,
1449 make_const
= make_volatile
= 0;
1450 make_addr_space
= 0;
1453 follow_type
= lookup_reference_type (follow_type
);
1455 follow_type
= make_cv_type (make_const
,
1456 TYPE_VOLATILE (follow_type
),
1459 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1462 if (make_addr_space
)
1463 follow_type
= make_type_with_address_space (follow_type
,
1465 make_const
= make_volatile
= 0;
1466 make_addr_space
= 0;
1469 array_size
= pop_type_int ();
1470 /* FIXME-type-allocation: need a way to free this type when we are
1473 lookup_array_range_type (follow_type
,
1474 0, array_size
>= 0 ? array_size
- 1 : 0);
1476 TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (follow_type
) = 1;
1479 /* FIXME-type-allocation: need a way to free this type when we are
1481 follow_type
= lookup_function_type (follow_type
);
1487 /* This function avoids direct calls to fprintf
1488 in the parser generated debug code. */
1490 parser_fprintf (FILE *x
, const char *y
, ...)
1496 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1499 fprintf_unfiltered (gdb_stderr
, " Unknown FILE used.\n");
1500 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1505 /* Implementation of the exp_descriptor method operator_check. */
1508 operator_check_standard (struct expression
*exp
, int pos
,
1509 int (*objfile_func
) (struct objfile
*objfile
,
1513 const union exp_element
*const elts
= exp
->elts
;
1514 struct type
*type
= NULL
;
1515 struct objfile
*objfile
= NULL
;
1517 /* Extended operators should have been already handled by exp_descriptor
1518 iterate method of its specific language. */
1519 gdb_assert (elts
[pos
].opcode
< OP_EXTENDED0
);
1521 /* Track the callers of write_exp_elt_type for this table. */
1523 switch (elts
[pos
].opcode
)
1533 case UNOP_DYNAMIC_CAST
:
1534 case UNOP_REINTERPRET_CAST
:
1538 type
= elts
[pos
+ 1].type
;
1543 LONGEST arg
, nargs
= elts
[pos
+ 1].longconst
;
1545 for (arg
= 0; arg
< nargs
; arg
++)
1547 struct type
*type
= elts
[pos
+ 2 + arg
].type
;
1548 struct objfile
*objfile
= TYPE_OBJFILE (type
);
1550 if (objfile
&& (*objfile_func
) (objfile
, data
))
1556 case UNOP_MEMVAL_TLS
:
1557 objfile
= elts
[pos
+ 1].objfile
;
1558 type
= elts
[pos
+ 2].type
;
1563 const struct block
*const block
= elts
[pos
+ 1].block
;
1564 const struct symbol
*const symbol
= elts
[pos
+ 2].symbol
;
1566 /* Check objfile where the variable itself is placed.
1567 SYMBOL_OBJ_SECTION (symbol) may be NULL. */
1568 if ((*objfile_func
) (SYMBOL_SYMTAB (symbol
)->objfile
, data
))
1571 /* Check objfile where is placed the code touching the variable. */
1572 objfile
= lookup_objfile_from_block (block
);
1574 type
= SYMBOL_TYPE (symbol
);
1579 /* Invoke callbacks for TYPE and OBJFILE if they were set as non-NULL. */
1581 if (type
&& TYPE_OBJFILE (type
)
1582 && (*objfile_func
) (TYPE_OBJFILE (type
), data
))
1584 if (objfile
&& (*objfile_func
) (objfile
, data
))
1590 /* Call OBJFILE_FUNC for any TYPE and OBJFILE found being referenced by EXP.
1591 The functions are never called with NULL OBJFILE. Functions get passed an
1592 arbitrary caller supplied DATA pointer. If any of the functions returns
1593 non-zero value then (any other) non-zero value is immediately returned to
1594 the caller. Otherwise zero is returned after iterating through whole EXP.
1598 exp_iterate (struct expression
*exp
,
1599 int (*objfile_func
) (struct objfile
*objfile
, void *data
),
1604 for (endpos
= exp
->nelts
; endpos
> 0; )
1606 int pos
, args
, oplen
= 0;
1608 operator_length (exp
, endpos
, &oplen
, &args
);
1609 gdb_assert (oplen
> 0);
1611 pos
= endpos
- oplen
;
1612 if (exp
->language_defn
->la_exp_desc
->operator_check (exp
, pos
,
1613 objfile_func
, data
))
1622 /* Helper for exp_uses_objfile. */
1625 exp_uses_objfile_iter (struct objfile
*exp_objfile
, void *objfile_voidp
)
1627 struct objfile
*objfile
= objfile_voidp
;
1629 if (exp_objfile
->separate_debug_objfile_backlink
)
1630 exp_objfile
= exp_objfile
->separate_debug_objfile_backlink
;
1632 return exp_objfile
== objfile
;
1635 /* Return 1 if EXP uses OBJFILE (and will become dangling when OBJFILE
1636 is unloaded), otherwise return 0. OBJFILE must not be a separate debug info
1640 exp_uses_objfile (struct expression
*exp
, struct objfile
*objfile
)
1642 gdb_assert (objfile
->separate_debug_objfile_backlink
== NULL
);
1644 return exp_iterate (exp
, exp_uses_objfile_iter
, objfile
);
1648 _initialize_parse (void)
1650 type_stack_size
= 80;
1651 type_stack_depth
= 0;
1652 type_stack
= (union type_stack_elt
*)
1653 xmalloc (type_stack_size
* sizeof (*type_stack
));
1655 add_setshow_zinteger_cmd ("expression", class_maintenance
,
1657 _("Set expression debugging."),
1658 _("Show expression debugging."),
1659 _("When non-zero, the internal representation "
1660 "of expressions will be printed."),
1662 show_expressiondebug
,
1663 &setdebuglist
, &showdebuglist
);
1664 add_setshow_boolean_cmd ("parser", class_maintenance
,
1666 _("Set parser debugging."),
1667 _("Show parser debugging."),
1668 _("When non-zero, expression parser "
1669 "tracing will be enabled."),
1672 &setdebuglist
, &showdebuglist
);