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 /* Helper function to initialize the expout, expout_size, expout_ptr
186 trio before it is used to store expression elements created during
187 the parsing of an expression. INITIAL_SIZE is the initial size of
188 the expout array. LANG is the language used to parse the expression.
189 And GDBARCH is the gdbarch to use during parsing. */
192 initialize_expout (int initial_size
, const struct language_defn
*lang
,
193 struct gdbarch
*gdbarch
)
195 expout_size
= initial_size
;
197 expout
= xmalloc (sizeof (struct expression
)
198 + EXP_ELEM_TO_BYTES (expout_size
));
199 expout
->language_defn
= lang
;
200 expout
->gdbarch
= gdbarch
;
203 /* Helper function that frees any unsed space in the expout array.
204 It is generally used when the parser has just been parsed and
208 reallocate_expout (void)
210 /* Record the actual number of expression elements, and then
211 reallocate the expression memory so that we free up any
214 expout
->nelts
= expout_ptr
;
215 expout
= xrealloc ((char *) expout
,
216 sizeof (struct expression
)
217 + EXP_ELEM_TO_BYTES (expout_ptr
));
220 /* Add one element to the end of the expression. */
222 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
223 a register through here. */
226 write_exp_elt (const union exp_element
*expelt
)
228 if (expout_ptr
>= expout_size
)
231 expout
= (struct expression
*)
232 xrealloc ((char *) expout
, sizeof (struct expression
)
233 + EXP_ELEM_TO_BYTES (expout_size
));
235 expout
->elts
[expout_ptr
++] = *expelt
;
239 write_exp_elt_opcode (enum exp_opcode expelt
)
241 union exp_element tmp
;
243 memset (&tmp
, 0, sizeof (union exp_element
));
245 write_exp_elt (&tmp
);
249 write_exp_elt_sym (struct symbol
*expelt
)
251 union exp_element tmp
;
253 memset (&tmp
, 0, sizeof (union exp_element
));
255 write_exp_elt (&tmp
);
259 write_exp_elt_block (struct block
*b
)
261 union exp_element tmp
;
263 memset (&tmp
, 0, sizeof (union exp_element
));
265 write_exp_elt (&tmp
);
269 write_exp_elt_objfile (struct objfile
*objfile
)
271 union exp_element tmp
;
273 memset (&tmp
, 0, sizeof (union exp_element
));
274 tmp
.objfile
= objfile
;
275 write_exp_elt (&tmp
);
279 write_exp_elt_longcst (LONGEST expelt
)
281 union exp_element tmp
;
283 memset (&tmp
, 0, sizeof (union exp_element
));
284 tmp
.longconst
= expelt
;
285 write_exp_elt (&tmp
);
289 write_exp_elt_dblcst (DOUBLEST expelt
)
291 union exp_element tmp
;
293 memset (&tmp
, 0, sizeof (union exp_element
));
294 tmp
.doubleconst
= expelt
;
295 write_exp_elt (&tmp
);
299 write_exp_elt_decfloatcst (gdb_byte expelt
[16])
301 union exp_element tmp
;
304 for (index
= 0; index
< 16; index
++)
305 tmp
.decfloatconst
[index
] = expelt
[index
];
307 write_exp_elt (&tmp
);
311 write_exp_elt_type (struct type
*expelt
)
313 union exp_element tmp
;
315 memset (&tmp
, 0, sizeof (union exp_element
));
317 write_exp_elt (&tmp
);
321 write_exp_elt_intern (struct internalvar
*expelt
)
323 union exp_element tmp
;
325 memset (&tmp
, 0, sizeof (union exp_element
));
326 tmp
.internalvar
= expelt
;
327 write_exp_elt (&tmp
);
330 /* Add a string constant to the end of the expression.
332 String constants are stored by first writing an expression element
333 that contains the length of the string, then stuffing the string
334 constant itself into however many expression elements are needed
335 to hold it, and then writing another expression element that contains
336 the length of the string. I.e. an expression element at each end of
337 the string records the string length, so you can skip over the
338 expression elements containing the actual string bytes from either
339 end of the string. Note that this also allows gdb to handle
340 strings with embedded null bytes, as is required for some languages.
342 Don't be fooled by the fact that the string is null byte terminated,
343 this is strictly for the convenience of debugging gdb itself.
344 Gdb does not depend up the string being null terminated, since the
345 actual length is recorded in expression elements at each end of the
346 string. The null byte is taken into consideration when computing how
347 many expression elements are required to hold the string constant, of
352 write_exp_string (struct stoken str
)
354 int len
= str
.length
;
358 /* Compute the number of expression elements required to hold the string
359 (including a null byte terminator), along with one expression element
360 at each end to record the actual string length (not including the
361 null byte terminator). */
363 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
+ 1);
365 /* Ensure that we have enough available expression elements to store
368 if ((expout_ptr
+ lenelt
) >= expout_size
)
370 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
371 expout
= (struct expression
*)
372 xrealloc ((char *) expout
, (sizeof (struct expression
)
373 + EXP_ELEM_TO_BYTES (expout_size
)));
376 /* Write the leading length expression element (which advances the current
377 expression element index), then write the string constant followed by a
378 terminating null byte, and then write the trailing length expression
381 write_exp_elt_longcst ((LONGEST
) len
);
382 strdata
= (char *) &expout
->elts
[expout_ptr
];
383 memcpy (strdata
, str
.ptr
, len
);
384 *(strdata
+ len
) = '\0';
385 expout_ptr
+= lenelt
- 2;
386 write_exp_elt_longcst ((LONGEST
) len
);
389 /* Add a vector of string constants to the end of the expression.
391 This adds an OP_STRING operation, but encodes the contents
392 differently from write_exp_string. The language is expected to
393 handle evaluation of this expression itself.
395 After the usual OP_STRING header, TYPE is written into the
396 expression as a long constant. The interpretation of this field is
397 up to the language evaluator.
399 Next, each string in VEC is written. The length is written as a
400 long constant, followed by the contents of the string. */
403 write_exp_string_vector (int type
, struct stoken_vector
*vec
)
407 /* Compute the size. We compute the size in number of slots to
408 avoid issues with string padding. */
410 for (i
= 0; i
< vec
->len
; ++i
)
412 /* One slot for the length of this element, plus the number of
413 slots needed for this string. */
414 n_slots
+= 1 + BYTES_TO_EXP_ELEM (vec
->tokens
[i
].length
);
417 /* One more slot for the type of the string. */
420 /* Now compute a phony string length. */
421 len
= EXP_ELEM_TO_BYTES (n_slots
) - 1;
424 if ((expout_ptr
+ n_slots
) >= expout_size
)
426 expout_size
= max (expout_size
* 2, expout_ptr
+ n_slots
+ 10);
427 expout
= (struct expression
*)
428 xrealloc ((char *) expout
, (sizeof (struct expression
)
429 + EXP_ELEM_TO_BYTES (expout_size
)));
432 write_exp_elt_opcode (OP_STRING
);
433 write_exp_elt_longcst (len
);
434 write_exp_elt_longcst (type
);
436 for (i
= 0; i
< vec
->len
; ++i
)
438 write_exp_elt_longcst (vec
->tokens
[i
].length
);
439 memcpy (&expout
->elts
[expout_ptr
], vec
->tokens
[i
].ptr
,
440 vec
->tokens
[i
].length
);
441 expout_ptr
+= BYTES_TO_EXP_ELEM (vec
->tokens
[i
].length
);
444 write_exp_elt_longcst (len
);
445 write_exp_elt_opcode (OP_STRING
);
448 /* Add a bitstring constant to the end of the expression.
450 Bitstring constants are stored by first writing an expression element
451 that contains the length of the bitstring (in bits), then stuffing the
452 bitstring constant itself into however many expression elements are
453 needed to hold it, and then writing another expression element that
454 contains the length of the bitstring. I.e. an expression element at
455 each end of the bitstring records the bitstring length, so you can skip
456 over the expression elements containing the actual bitstring bytes from
457 either end of the bitstring. */
460 write_exp_bitstring (struct stoken str
)
462 int bits
= str
.length
; /* length in bits */
463 int len
= (bits
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
467 /* Compute the number of expression elements required to hold the bitstring,
468 along with one expression element at each end to record the actual
469 bitstring length in bits. */
471 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
);
473 /* Ensure that we have enough available expression elements to store
476 if ((expout_ptr
+ lenelt
) >= expout_size
)
478 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
479 expout
= (struct expression
*)
480 xrealloc ((char *) expout
, (sizeof (struct expression
)
481 + EXP_ELEM_TO_BYTES (expout_size
)));
484 /* Write the leading length expression element (which advances the current
485 expression element index), then write the bitstring constant, and then
486 write the trailing length expression element. */
488 write_exp_elt_longcst ((LONGEST
) bits
);
489 strdata
= (char *) &expout
->elts
[expout_ptr
];
490 memcpy (strdata
, str
.ptr
, len
);
491 expout_ptr
+= lenelt
- 2;
492 write_exp_elt_longcst ((LONGEST
) bits
);
495 /* Add the appropriate elements for a minimal symbol to the end of
499 write_exp_msymbol (struct minimal_symbol
*msymbol
)
501 struct objfile
*objfile
= msymbol_objfile (msymbol
);
502 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
504 CORE_ADDR addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
505 struct obj_section
*section
= SYMBOL_OBJ_SECTION (msymbol
);
506 enum minimal_symbol_type type
= MSYMBOL_TYPE (msymbol
);
509 /* The minimal symbol might point to a function descriptor;
510 resolve it to the actual code address instead. */
511 pc
= gdbarch_convert_from_func_ptr_addr (gdbarch
, addr
, ¤t_target
);
514 struct minimal_symbol
*ifunc_msym
= lookup_minimal_symbol_by_pc (pc
);
516 /* In this case, assume we have a code symbol instead of
519 if (ifunc_msym
!= NULL
&& MSYMBOL_TYPE (ifunc_msym
) == mst_text_gnu_ifunc
520 && SYMBOL_VALUE_ADDRESS (ifunc_msym
) == pc
)
522 /* A function descriptor has been resolved but PC is still in the
523 STT_GNU_IFUNC resolver body (such as because inferior does not
524 run to be able to call it). */
526 type
= mst_text_gnu_ifunc
;
534 if (overlay_debugging
)
535 addr
= symbol_overlayed_address (addr
, section
);
537 write_exp_elt_opcode (OP_LONG
);
538 /* Let's make the type big enough to hold a 64-bit address. */
539 write_exp_elt_type (objfile_type (objfile
)->builtin_core_addr
);
540 write_exp_elt_longcst ((LONGEST
) addr
);
541 write_exp_elt_opcode (OP_LONG
);
543 if (section
&& section
->the_bfd_section
->flags
& SEC_THREAD_LOCAL
)
545 write_exp_elt_opcode (UNOP_MEMVAL_TLS
);
546 write_exp_elt_objfile (objfile
);
547 write_exp_elt_type (objfile_type (objfile
)->nodebug_tls_symbol
);
548 write_exp_elt_opcode (UNOP_MEMVAL_TLS
);
552 write_exp_elt_opcode (UNOP_MEMVAL
);
557 case mst_solib_trampoline
:
558 write_exp_elt_type (objfile_type (objfile
)->nodebug_text_symbol
);
561 case mst_text_gnu_ifunc
:
562 write_exp_elt_type (objfile_type (objfile
)
563 ->nodebug_text_gnu_ifunc_symbol
);
570 write_exp_elt_type (objfile_type (objfile
)->nodebug_data_symbol
);
573 case mst_slot_got_plt
:
574 write_exp_elt_type (objfile_type (objfile
)->nodebug_got_plt_symbol
);
578 write_exp_elt_type (objfile_type (objfile
)->nodebug_unknown_symbol
);
581 write_exp_elt_opcode (UNOP_MEMVAL
);
584 /* Mark the current index as the starting location of a structure
585 expression. This is used when completing on field names. */
588 mark_struct_expression (void)
590 expout_last_struct
= expout_ptr
;
594 /* Recognize tokens that start with '$'. These include:
596 $regname A native register name or a "standard
599 $variable A convenience variable with a name chosen
602 $digits Value history with index <digits>, starting
603 from the first value which has index 1.
605 $$digits Value history with index <digits> relative
606 to the last value. I.e. $$0 is the last
607 value, $$1 is the one previous to that, $$2
608 is the one previous to $$1, etc.
610 $ | $0 | $$0 The last value in the value history.
612 $$ An abbreviation for the second to the last
613 value in the value history, I.e. $$1 */
616 write_dollar_variable (struct stoken str
)
618 struct symbol
*sym
= NULL
;
619 struct minimal_symbol
*msym
= NULL
;
620 struct internalvar
*isym
= NULL
;
622 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
623 and $$digits (equivalent to $<-digits> if you could type that). */
627 /* Double dollar means negate the number and add -1 as well.
628 Thus $$ alone means -1. */
629 if (str
.length
>= 2 && str
.ptr
[1] == '$')
636 /* Just dollars (one or two). */
640 /* Is the rest of the token digits? */
641 for (; i
< str
.length
; i
++)
642 if (!(str
.ptr
[i
] >= '0' && str
.ptr
[i
] <= '9'))
646 i
= atoi (str
.ptr
+ 1 + negate
);
652 /* Handle tokens that refer to machine registers:
653 $ followed by a register name. */
654 i
= user_reg_map_name_to_regnum (parse_gdbarch
,
655 str
.ptr
+ 1, str
.length
- 1);
657 goto handle_register
;
659 /* Any names starting with $ are probably debugger internal variables. */
661 isym
= lookup_only_internalvar (copy_name (str
) + 1);
664 write_exp_elt_opcode (OP_INTERNALVAR
);
665 write_exp_elt_intern (isym
);
666 write_exp_elt_opcode (OP_INTERNALVAR
);
670 /* On some systems, such as HP-UX and hppa-linux, certain system routines
671 have names beginning with $ or $$. Check for those, first. */
673 sym
= lookup_symbol (copy_name (str
), (struct block
*) NULL
,
674 VAR_DOMAIN
, (int *) NULL
);
677 write_exp_elt_opcode (OP_VAR_VALUE
);
678 write_exp_elt_block (block_found
); /* set by lookup_symbol */
679 write_exp_elt_sym (sym
);
680 write_exp_elt_opcode (OP_VAR_VALUE
);
683 msym
= lookup_minimal_symbol (copy_name (str
), NULL
, NULL
);
686 write_exp_msymbol (msym
);
690 /* Any other names are assumed to be debugger internal variables. */
692 write_exp_elt_opcode (OP_INTERNALVAR
);
693 write_exp_elt_intern (create_internalvar (copy_name (str
) + 1));
694 write_exp_elt_opcode (OP_INTERNALVAR
);
697 write_exp_elt_opcode (OP_LAST
);
698 write_exp_elt_longcst ((LONGEST
) i
);
699 write_exp_elt_opcode (OP_LAST
);
702 write_exp_elt_opcode (OP_REGISTER
);
705 write_exp_string (str
);
706 write_exp_elt_opcode (OP_REGISTER
);
712 find_template_name_end (char *p
)
715 int just_seen_right
= 0;
716 int just_seen_colon
= 0;
717 int just_seen_space
= 0;
719 if (!p
|| (*p
!= '<'))
730 /* In future, may want to allow these?? */
733 depth
++; /* start nested template */
734 if (just_seen_colon
|| just_seen_right
|| just_seen_space
)
735 return 0; /* but not after : or :: or > or space */
738 if (just_seen_colon
|| just_seen_right
)
739 return 0; /* end a (nested?) template */
740 just_seen_right
= 1; /* but not after : or :: */
741 if (--depth
== 0) /* also disallow >>, insist on > > */
742 return ++p
; /* if outermost ended, return */
745 if (just_seen_space
|| (just_seen_colon
> 1))
746 return 0; /* nested class spec coming up */
747 just_seen_colon
++; /* we allow :: but not :::: */
752 if (!((*p
>= 'a' && *p
<= 'z') || /* allow token chars */
753 (*p
>= 'A' && *p
<= 'Z') ||
754 (*p
>= '0' && *p
<= '9') ||
755 (*p
== '_') || (*p
== ',') || /* commas for template args */
756 (*p
== '&') || (*p
== '*') || /* pointer and ref types */
757 (*p
== '(') || (*p
== ')') || /* function types */
758 (*p
== '[') || (*p
== ']'))) /* array types */
772 /* Return a null-terminated temporary copy of the name of a string token.
774 Tokens that refer to names do so with explicit pointer and length,
775 so they can share the storage that lexptr is parsing.
776 When it is necessary to pass a name to a function that expects
777 a null-terminated string, the substring is copied out
778 into a separate block of storage.
780 N.B. A single buffer is reused on each call. */
783 copy_name (struct stoken token
)
785 /* A temporary buffer for identifiers, so we can null-terminate them.
786 We allocate this with xrealloc. parse_exp_1 used to allocate with
787 alloca, using the size of the whole expression as a conservative
788 estimate of the space needed. However, macro expansion can
789 introduce names longer than the original expression; there's no
790 practical way to know beforehand how large that might be. */
791 static char *namecopy
;
792 static size_t namecopy_size
;
794 /* Make sure there's enough space for the token. */
795 if (namecopy_size
< token
.length
+ 1)
797 namecopy_size
= token
.length
+ 1;
798 namecopy
= xrealloc (namecopy
, token
.length
+ 1);
801 memcpy (namecopy
, token
.ptr
, token
.length
);
802 namecopy
[token
.length
] = 0;
807 /* Reverse an expression from suffix form (in which it is constructed)
808 to prefix form (in which we can conveniently print or execute it).
809 Ordinarily this always returns -1. However, if EXPOUT_LAST_STRUCT
810 is not -1 (i.e., we are trying to complete a field name), it will
811 return the index of the subexpression which is the left-hand-side
812 of the struct operation at EXPOUT_LAST_STRUCT. */
815 prefixify_expression (struct expression
*expr
)
817 int len
= sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expr
->nelts
);
818 struct expression
*temp
;
819 int inpos
= expr
->nelts
, outpos
= 0;
821 temp
= (struct expression
*) alloca (len
);
823 /* Copy the original expression into temp. */
824 memcpy (temp
, expr
, len
);
826 return prefixify_subexp (temp
, expr
, inpos
, outpos
);
829 /* Return the number of exp_elements in the postfix subexpression
830 of EXPR whose operator is at index ENDPOS - 1 in EXPR. */
833 length_of_subexp (struct expression
*expr
, int endpos
)
837 operator_length (expr
, endpos
, &oplen
, &args
);
841 oplen
+= length_of_subexp (expr
, endpos
- oplen
);
848 /* Sets *OPLENP to the length of the operator whose (last) index is
849 ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
853 operator_length (const struct expression
*expr
, int endpos
, int *oplenp
,
856 expr
->language_defn
->la_exp_desc
->operator_length (expr
, endpos
,
860 /* Default value for operator_length in exp_descriptor vectors. */
863 operator_length_standard (const struct expression
*expr
, int endpos
,
864 int *oplenp
, int *argsp
)
868 enum f90_range_type range_type
;
872 error (_("?error in operator_length_standard"));
874 i
= (int) expr
->elts
[endpos
- 1].opcode
;
880 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
881 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
895 case OP_VAR_ENTRY_VALUE
:
905 case OP_F77_UNDETERMINED_ARGLIST
:
907 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
911 oplen
= 4 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
915 case OP_OBJC_MSGCALL
: /* Objective C message (method) call. */
917 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
927 case UNOP_DYNAMIC_CAST
:
928 case UNOP_REINTERPRET_CAST
:
934 case UNOP_MEMVAL_TLS
:
952 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
953 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
959 case STRUCTOP_STRUCT
:
966 case OP_OBJC_NSSTRING
: /* Objective C Foundation Class
967 NSString constant. */
968 case OP_OBJC_SELECTOR
: /* Objective C "@selector" pseudo-op. */
970 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
971 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
975 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
976 oplen
= (oplen
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
977 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
);
982 args
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
983 args
-= longest_to_int (expr
->elts
[endpos
- 3].longconst
);
989 case TERNOP_SLICE_COUNT
:
994 case MULTI_SUBSCRIPT
:
996 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
999 case BINOP_ASSIGN_MODIFY
:
1012 range_type
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
1015 case LOW_BOUND_DEFAULT
:
1016 case HIGH_BOUND_DEFAULT
:
1019 case BOTH_BOUND_DEFAULT
:
1022 case NONE_BOUND_DEFAULT
:
1030 args
= 1 + (i
< (int) BINOP_END
);
1037 /* Copy the subexpression ending just before index INEND in INEXPR
1038 into OUTEXPR, starting at index OUTBEG.
1039 In the process, convert it from suffix to prefix form.
1040 If EXPOUT_LAST_STRUCT is -1, then this function always returns -1.
1041 Otherwise, it returns the index of the subexpression which is the
1042 left-hand-side of the expression at EXPOUT_LAST_STRUCT. */
1045 prefixify_subexp (struct expression
*inexpr
,
1046 struct expression
*outexpr
, int inend
, int outbeg
)
1054 operator_length (inexpr
, inend
, &oplen
, &args
);
1056 /* Copy the final operator itself, from the end of the input
1057 to the beginning of the output. */
1059 memcpy (&outexpr
->elts
[outbeg
], &inexpr
->elts
[inend
],
1060 EXP_ELEM_TO_BYTES (oplen
));
1063 if (expout_last_struct
== inend
)
1064 result
= outbeg
- oplen
;
1066 /* Find the lengths of the arg subexpressions. */
1067 arglens
= (int *) alloca (args
* sizeof (int));
1068 for (i
= args
- 1; i
>= 0; i
--)
1070 oplen
= length_of_subexp (inexpr
, inend
);
1075 /* Now copy each subexpression, preserving the order of
1076 the subexpressions, but prefixifying each one.
1077 In this loop, inend starts at the beginning of
1078 the expression this level is working on
1079 and marches forward over the arguments.
1080 outbeg does similarly in the output. */
1081 for (i
= 0; i
< args
; i
++)
1087 r
= prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
);
1090 /* Return immediately. We probably have only parsed a
1091 partial expression, so we don't want to try to reverse
1092 the other operands. */
1101 /* Read an expression from the string *STRINGPTR points to,
1102 parse it, and return a pointer to a struct expression that we malloc.
1103 Use block BLOCK as the lexical context for variable names;
1104 if BLOCK is zero, use the block of the selected stack frame.
1105 Meanwhile, advance *STRINGPTR to point after the expression,
1106 at the first nonwhite character that is not part of the expression
1107 (possibly a null character).
1109 If COMMA is nonzero, stop if a comma is reached. */
1112 parse_exp_1 (char **stringptr
, struct block
*block
, int comma
)
1114 return parse_exp_in_context (stringptr
, block
, comma
, 0, NULL
);
1117 /* As for parse_exp_1, except that if VOID_CONTEXT_P, then
1118 no value is expected from the expression.
1119 OUT_SUBEXP is set when attempting to complete a field name; in this
1120 case it is set to the index of the subexpression on the
1121 left-hand-side of the struct op. If not doing such completion, it
1122 is left untouched. */
1124 static struct expression
*
1125 parse_exp_in_context (char **stringptr
, struct block
*block
, int comma
,
1126 int void_context_p
, int *out_subexp
)
1128 volatile struct gdb_exception except
;
1129 struct cleanup
*old_chain
;
1130 const struct language_defn
*lang
= NULL
;
1133 lexptr
= *stringptr
;
1137 type_stack_depth
= 0;
1138 expout_last_struct
= -1;
1140 comma_terminates
= comma
;
1142 if (lexptr
== 0 || *lexptr
== 0)
1143 error_no_arg (_("expression to compute"));
1145 old_chain
= make_cleanup (free_funcalls
, 0 /*ignore*/);
1148 expression_context_block
= block
;
1150 /* If no context specified, try using the current frame, if any. */
1151 if (!expression_context_block
)
1152 expression_context_block
= get_selected_block (&expression_context_pc
);
1154 expression_context_pc
= BLOCK_START (expression_context_block
);
1156 /* Fall back to using the current source static context, if any. */
1158 if (!expression_context_block
)
1160 struct symtab_and_line cursal
= get_current_source_symtab_and_line ();
1162 expression_context_block
1163 = BLOCKVECTOR_BLOCK (BLOCKVECTOR (cursal
.symtab
), STATIC_BLOCK
);
1164 if (expression_context_block
)
1165 expression_context_pc
= BLOCK_START (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 initialize_expout (10, lang
, get_current_arch ());
1196 TRY_CATCH (except
, RETURN_MASK_ALL
)
1198 if (lang
->la_parser ())
1199 lang
->la_error (NULL
);
1201 if (except
.reason
< 0)
1203 if (! in_parse_field
)
1206 throw_exception (except
);
1210 discard_cleanups (old_chain
);
1212 reallocate_expout ();
1214 /* Convert expression from postfix form as generated by yacc
1215 parser, to a prefix form. */
1217 if (expressiondebug
)
1218 dump_raw_expression (expout
, gdb_stdlog
,
1219 "before conversion to prefix form");
1221 subexp
= prefixify_expression (expout
);
1223 *out_subexp
= subexp
;
1225 lang
->la_post_parser (&expout
, void_context_p
);
1227 if (expressiondebug
)
1228 dump_prefix_expression (expout
, gdb_stdlog
);
1230 *stringptr
= lexptr
;
1234 /* Parse STRING as an expression, and complain if this fails
1235 to use up all of the contents of STRING. */
1238 parse_expression (char *string
)
1240 struct expression
*exp
;
1242 exp
= parse_exp_1 (&string
, 0, 0);
1244 error (_("Junk after end of expression."));
1248 /* Parse STRING as an expression. If parsing ends in the middle of a
1249 field reference, return the type of the left-hand-side of the
1250 reference; furthermore, if the parsing ends in the field name,
1251 return the field name in *NAME. If the parsing ends in the middle
1252 of a field reference, but the reference is somehow invalid, throw
1253 an exception. In all other cases, return NULL. Returned non-NULL
1254 *NAME must be freed by the caller. */
1257 parse_field_expression (char *string
, char **name
)
1259 struct expression
*exp
= NULL
;
1262 volatile struct gdb_exception except
;
1264 TRY_CATCH (except
, RETURN_MASK_ERROR
)
1267 exp
= parse_exp_in_context (&string
, 0, 0, 0, &subexp
);
1270 if (except
.reason
< 0 || ! exp
)
1272 if (expout_last_struct
== -1)
1278 *name
= extract_field_op (exp
, &subexp
);
1285 /* This might throw an exception. If so, we want to let it
1287 val
= evaluate_subexpression_type (exp
, subexp
);
1288 /* (*NAME) is a part of the EXP memory block freed below. */
1289 *name
= xstrdup (*name
);
1292 return value_type (val
);
1295 /* A post-parser that does nothing. */
1298 null_post_parser (struct expression
**exp
, int void_context_p
)
1302 /* Parse floating point value P of length LEN.
1303 Return 0 (false) if invalid, 1 (true) if valid.
1304 The successfully parsed number is stored in D.
1305 *SUFFIX points to the suffix of the number in P.
1307 NOTE: This accepts the floating point syntax that sscanf accepts. */
1310 parse_float (const char *p
, int len
, DOUBLEST
*d
, const char **suffix
)
1316 copy
= xmalloc (len
+ 1);
1317 memcpy (copy
, p
, len
);
1320 num
= sscanf (copy
, "%" DOUBLEST_SCAN_FORMAT
"%n", d
, &n
);
1323 /* The sscanf man page suggests not making any assumptions on the effect
1324 of %n on the result, so we don't.
1325 That is why we simply test num == 0. */
1333 /* Parse floating point value P of length LEN, using the C syntax for floats.
1334 Return 0 (false) if invalid, 1 (true) if valid.
1335 The successfully parsed number is stored in *D.
1336 Its type is taken from builtin_type (gdbarch) and is stored in *T. */
1339 parse_c_float (struct gdbarch
*gdbarch
, const char *p
, int len
,
1340 DOUBLEST
*d
, struct type
**t
)
1344 const struct builtin_type
*builtin_types
= builtin_type (gdbarch
);
1346 if (! parse_float (p
, len
, d
, &suffix
))
1349 suffix_len
= p
+ len
- suffix
;
1351 if (suffix_len
== 0)
1352 *t
= builtin_types
->builtin_double
;
1353 else if (suffix_len
== 1)
1355 /* Handle suffixes: 'f' for float, 'l' for long double. */
1356 if (tolower (*suffix
) == 'f')
1357 *t
= builtin_types
->builtin_float
;
1358 else if (tolower (*suffix
) == 'l')
1359 *t
= builtin_types
->builtin_long_double
;
1369 /* Stuff for maintaining a stack of types. Currently just used by C, but
1370 probably useful for any language which declares its types "backwards". */
1373 check_type_stack_depth (void)
1375 if (type_stack_depth
== type_stack_size
)
1377 type_stack_size
*= 2;
1378 type_stack
= (union type_stack_elt
*)
1379 xrealloc ((char *) type_stack
, type_stack_size
* sizeof (*type_stack
));
1384 push_type (enum type_pieces tp
)
1386 check_type_stack_depth ();
1387 type_stack
[type_stack_depth
++].piece
= tp
;
1391 push_type_int (int n
)
1393 check_type_stack_depth ();
1394 type_stack
[type_stack_depth
++].int_val
= n
;
1398 push_type_address_space (char *string
)
1400 push_type_int (address_space_name_to_int (parse_gdbarch
, string
));
1406 if (type_stack_depth
)
1407 return type_stack
[--type_stack_depth
].piece
;
1414 if (type_stack_depth
)
1415 return type_stack
[--type_stack_depth
].int_val
;
1416 /* "Can't happen". */
1420 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1421 as modified by all the stuff on the stack. */
1423 follow_types (struct type
*follow_type
)
1427 int make_volatile
= 0;
1428 int make_addr_space
= 0;
1432 switch (pop_type ())
1437 follow_type
= make_cv_type (make_const
,
1438 TYPE_VOLATILE (follow_type
),
1441 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1444 if (make_addr_space
)
1445 follow_type
= make_type_with_address_space (follow_type
,
1447 make_const
= make_volatile
= 0;
1448 make_addr_space
= 0;
1456 case tp_space_identifier
:
1457 make_addr_space
= pop_type_int ();
1460 follow_type
= lookup_pointer_type (follow_type
);
1462 follow_type
= make_cv_type (make_const
,
1463 TYPE_VOLATILE (follow_type
),
1466 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1469 if (make_addr_space
)
1470 follow_type
= make_type_with_address_space (follow_type
,
1472 make_const
= make_volatile
= 0;
1473 make_addr_space
= 0;
1476 follow_type
= lookup_reference_type (follow_type
);
1478 follow_type
= make_cv_type (make_const
,
1479 TYPE_VOLATILE (follow_type
),
1482 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1485 if (make_addr_space
)
1486 follow_type
= make_type_with_address_space (follow_type
,
1488 make_const
= make_volatile
= 0;
1489 make_addr_space
= 0;
1492 array_size
= pop_type_int ();
1493 /* FIXME-type-allocation: need a way to free this type when we are
1496 lookup_array_range_type (follow_type
,
1497 0, array_size
>= 0 ? array_size
- 1 : 0);
1499 TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (follow_type
) = 1;
1502 /* FIXME-type-allocation: need a way to free this type when we are
1504 follow_type
= lookup_function_type (follow_type
);
1510 /* This function avoids direct calls to fprintf
1511 in the parser generated debug code. */
1513 parser_fprintf (FILE *x
, const char *y
, ...)
1519 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1522 fprintf_unfiltered (gdb_stderr
, " Unknown FILE used.\n");
1523 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1528 /* Implementation of the exp_descriptor method operator_check. */
1531 operator_check_standard (struct expression
*exp
, int pos
,
1532 int (*objfile_func
) (struct objfile
*objfile
,
1536 const union exp_element
*const elts
= exp
->elts
;
1537 struct type
*type
= NULL
;
1538 struct objfile
*objfile
= NULL
;
1540 /* Extended operators should have been already handled by exp_descriptor
1541 iterate method of its specific language. */
1542 gdb_assert (elts
[pos
].opcode
< OP_EXTENDED0
);
1544 /* Track the callers of write_exp_elt_type for this table. */
1546 switch (elts
[pos
].opcode
)
1556 case UNOP_DYNAMIC_CAST
:
1557 case UNOP_REINTERPRET_CAST
:
1561 type
= elts
[pos
+ 1].type
;
1566 LONGEST arg
, nargs
= elts
[pos
+ 1].longconst
;
1568 for (arg
= 0; arg
< nargs
; arg
++)
1570 struct type
*type
= elts
[pos
+ 2 + arg
].type
;
1571 struct objfile
*objfile
= TYPE_OBJFILE (type
);
1573 if (objfile
&& (*objfile_func
) (objfile
, data
))
1579 case UNOP_MEMVAL_TLS
:
1580 objfile
= elts
[pos
+ 1].objfile
;
1581 type
= elts
[pos
+ 2].type
;
1586 const struct block
*const block
= elts
[pos
+ 1].block
;
1587 const struct symbol
*const symbol
= elts
[pos
+ 2].symbol
;
1589 /* Check objfile where the variable itself is placed.
1590 SYMBOL_OBJ_SECTION (symbol) may be NULL. */
1591 if ((*objfile_func
) (SYMBOL_SYMTAB (symbol
)->objfile
, data
))
1594 /* Check objfile where is placed the code touching the variable. */
1595 objfile
= lookup_objfile_from_block (block
);
1597 type
= SYMBOL_TYPE (symbol
);
1602 /* Invoke callbacks for TYPE and OBJFILE if they were set as non-NULL. */
1604 if (type
&& TYPE_OBJFILE (type
)
1605 && (*objfile_func
) (TYPE_OBJFILE (type
), data
))
1607 if (objfile
&& (*objfile_func
) (objfile
, data
))
1613 /* Call OBJFILE_FUNC for any TYPE and OBJFILE found being referenced by EXP.
1614 The functions are never called with NULL OBJFILE. Functions get passed an
1615 arbitrary caller supplied DATA pointer. If any of the functions returns
1616 non-zero value then (any other) non-zero value is immediately returned to
1617 the caller. Otherwise zero is returned after iterating through whole EXP.
1621 exp_iterate (struct expression
*exp
,
1622 int (*objfile_func
) (struct objfile
*objfile
, void *data
),
1627 for (endpos
= exp
->nelts
; endpos
> 0; )
1629 int pos
, args
, oplen
= 0;
1631 operator_length (exp
, endpos
, &oplen
, &args
);
1632 gdb_assert (oplen
> 0);
1634 pos
= endpos
- oplen
;
1635 if (exp
->language_defn
->la_exp_desc
->operator_check (exp
, pos
,
1636 objfile_func
, data
))
1645 /* Helper for exp_uses_objfile. */
1648 exp_uses_objfile_iter (struct objfile
*exp_objfile
, void *objfile_voidp
)
1650 struct objfile
*objfile
= objfile_voidp
;
1652 if (exp_objfile
->separate_debug_objfile_backlink
)
1653 exp_objfile
= exp_objfile
->separate_debug_objfile_backlink
;
1655 return exp_objfile
== objfile
;
1658 /* Return 1 if EXP uses OBJFILE (and will become dangling when OBJFILE
1659 is unloaded), otherwise return 0. OBJFILE must not be a separate debug info
1663 exp_uses_objfile (struct expression
*exp
, struct objfile
*objfile
)
1665 gdb_assert (objfile
->separate_debug_objfile_backlink
== NULL
);
1667 return exp_iterate (exp
, exp_uses_objfile_iter
, objfile
);
1671 _initialize_parse (void)
1673 type_stack_size
= 80;
1674 type_stack_depth
= 0;
1675 type_stack
= (union type_stack_elt
*)
1676 xmalloc (type_stack_size
* sizeof (*type_stack
));
1678 add_setshow_zinteger_cmd ("expression", class_maintenance
,
1680 _("Set expression debugging."),
1681 _("Show expression debugging."),
1682 _("When non-zero, the internal representation "
1683 "of expressions will be printed."),
1685 show_expressiondebug
,
1686 &setdebuglist
, &showdebuglist
);
1687 add_setshow_boolean_cmd ("parser", class_maintenance
,
1689 _("Set parser debugging."),
1690 _("Show parser debugging."),
1691 _("When non-zero, expression parser "
1692 "tracing will be enabled."),
1695 &setdebuglist
, &showdebuglist
);