1 /* Parse expressions for GDB.
3 Copyright (C) 1986, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
4 1997, 1998, 1999, 2000, 2001, 2004, 2005 Free Software Foundation, Inc.
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 2 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, write to the Free Software
23 Foundation, Inc., 51 Franklin Street, Fifth Floor,
24 Boston, MA 02110-1301, USA. */
26 /* Parse an expression from text in a string,
27 and return the result as a struct expression pointer.
28 That structure contains arithmetic operations in reverse polish,
29 with constants represented by operations that are followed by special data.
30 See expression.h for the details of the format.
31 What is important here is that it can be built up sequentially
32 during the process of parsing; the lower levels of the tree always
33 come first in the result. */
38 #include "gdb_string.h"
42 #include "expression.h"
47 #include "parser-defs.h"
49 #include "symfile.h" /* for overlay functions */
50 #include "inferior.h" /* for NUM_PSEUDO_REGS. NOTE: replace
51 with "gdbarch.h" when appropriate. */
53 #include "gdb_assert.h"
56 /* Standard set of definitions for printing, dumping, prefixifying,
57 * and evaluating expressions. */
59 const struct exp_descriptor exp_descriptor_standard
=
61 print_subexp_standard
,
62 operator_length_standard
,
64 dump_subexp_body_standard
,
65 evaluate_subexp_standard
68 /* Global variables declared in parser-defs.h (and commented there). */
69 struct expression
*expout
;
72 struct block
*expression_context_block
;
73 CORE_ADDR expression_context_pc
;
74 struct block
*innermost_block
;
76 union type_stack_elt
*type_stack
;
77 int type_stack_depth
, type_stack_size
;
83 /* A temporary buffer for identifiers, so we can null-terminate them.
85 We allocate this with xrealloc. parse_exp_1 used to allocate with
86 alloca, using the size of the whole expression as a conservative
87 estimate of the space needed. However, macro expansion can
88 introduce names longer than the original expression; there's no
89 practical way to know beforehand how large that might be. */
93 static int expressiondebug
= 0;
95 show_expressiondebug (struct ui_file
*file
, int from_tty
,
96 struct cmd_list_element
*c
, const char *value
)
98 fprintf_filtered (file
, _("Expression debugging is %s.\n"), value
);
101 static void free_funcalls (void *ignore
);
103 static void prefixify_expression (struct expression
*);
105 static void prefixify_subexp (struct expression
*, struct expression
*, int,
108 static struct expression
*parse_exp_in_context (char **, struct block
*, int,
111 void _initialize_parse (void);
113 /* Data structure for saving values of arglist_len for function calls whose
114 arguments contain other function calls. */
118 struct funcall
*next
;
122 static struct funcall
*funcall_chain
;
124 /* Begin counting arguments for a function call,
125 saving the data about any containing call. */
132 new = (struct funcall
*) xmalloc (sizeof (struct funcall
));
133 new->next
= funcall_chain
;
134 new->arglist_len
= arglist_len
;
139 /* Return the number of arguments in a function call just terminated,
140 and restore the data for the containing function call. */
145 int val
= arglist_len
;
146 struct funcall
*call
= funcall_chain
;
147 funcall_chain
= call
->next
;
148 arglist_len
= call
->arglist_len
;
153 /* Free everything in the funcall chain.
154 Used when there is an error inside parsing. */
157 free_funcalls (void *ignore
)
159 struct funcall
*call
, *next
;
161 for (call
= funcall_chain
; call
; call
= next
)
168 /* This page contains the functions for adding data to the struct expression
169 being constructed. */
171 /* Add one element to the end of the expression. */
173 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
174 a register through here */
177 write_exp_elt (union exp_element expelt
)
179 if (expout_ptr
>= expout_size
)
182 expout
= (struct expression
*)
183 xrealloc ((char *) expout
, sizeof (struct expression
)
184 + EXP_ELEM_TO_BYTES (expout_size
));
186 expout
->elts
[expout_ptr
++] = expelt
;
190 write_exp_elt_opcode (enum exp_opcode expelt
)
192 union exp_element tmp
;
200 write_exp_elt_sym (struct symbol
*expelt
)
202 union exp_element tmp
;
210 write_exp_elt_block (struct block
*b
)
212 union exp_element tmp
;
218 write_exp_elt_longcst (LONGEST expelt
)
220 union exp_element tmp
;
222 tmp
.longconst
= expelt
;
228 write_exp_elt_dblcst (DOUBLEST expelt
)
230 union exp_element tmp
;
232 tmp
.doubleconst
= expelt
;
238 write_exp_elt_type (struct type
*expelt
)
240 union exp_element tmp
;
248 write_exp_elt_intern (struct internalvar
*expelt
)
250 union exp_element tmp
;
252 tmp
.internalvar
= expelt
;
257 /* Add a string constant to the end of the expression.
259 String constants are stored by first writing an expression element
260 that contains the length of the string, then stuffing the string
261 constant itself into however many expression elements are needed
262 to hold it, and then writing another expression element that contains
263 the length of the string. I.E. an expression element at each end of
264 the string records the string length, so you can skip over the
265 expression elements containing the actual string bytes from either
266 end of the string. Note that this also allows gdb to handle
267 strings with embedded null bytes, as is required for some languages.
269 Don't be fooled by the fact that the string is null byte terminated,
270 this is strictly for the convenience of debugging gdb itself. Gdb
271 Gdb does not depend up the string being null terminated, since the
272 actual length is recorded in expression elements at each end of the
273 string. The null byte is taken into consideration when computing how
274 many expression elements are required to hold the string constant, of
279 write_exp_string (struct stoken str
)
281 int len
= str
.length
;
285 /* Compute the number of expression elements required to hold the string
286 (including a null byte terminator), along with one expression element
287 at each end to record the actual string length (not including the
288 null byte terminator). */
290 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
+ 1);
292 /* Ensure that we have enough available expression elements to store
295 if ((expout_ptr
+ lenelt
) >= expout_size
)
297 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
298 expout
= (struct expression
*)
299 xrealloc ((char *) expout
, (sizeof (struct expression
)
300 + EXP_ELEM_TO_BYTES (expout_size
)));
303 /* Write the leading length expression element (which advances the current
304 expression element index), then write the string constant followed by a
305 terminating null byte, and then write the trailing length expression
308 write_exp_elt_longcst ((LONGEST
) len
);
309 strdata
= (char *) &expout
->elts
[expout_ptr
];
310 memcpy (strdata
, str
.ptr
, len
);
311 *(strdata
+ len
) = '\0';
312 expout_ptr
+= lenelt
- 2;
313 write_exp_elt_longcst ((LONGEST
) len
);
316 /* Add a bitstring constant to the end of the expression.
318 Bitstring constants are stored by first writing an expression element
319 that contains the length of the bitstring (in bits), then stuffing the
320 bitstring constant itself into however many expression elements are
321 needed to hold it, and then writing another expression element that
322 contains the length of the bitstring. I.E. an expression element at
323 each end of the bitstring records the bitstring length, so you can skip
324 over the expression elements containing the actual bitstring bytes from
325 either end of the bitstring. */
328 write_exp_bitstring (struct stoken str
)
330 int bits
= str
.length
; /* length in bits */
331 int len
= (bits
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
335 /* Compute the number of expression elements required to hold the bitstring,
336 along with one expression element at each end to record the actual
337 bitstring length in bits. */
339 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
);
341 /* Ensure that we have enough available expression elements to store
344 if ((expout_ptr
+ lenelt
) >= expout_size
)
346 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
347 expout
= (struct expression
*)
348 xrealloc ((char *) expout
, (sizeof (struct expression
)
349 + EXP_ELEM_TO_BYTES (expout_size
)));
352 /* Write the leading length expression element (which advances the current
353 expression element index), then write the bitstring constant, and then
354 write the trailing length expression element. */
356 write_exp_elt_longcst ((LONGEST
) bits
);
357 strdata
= (char *) &expout
->elts
[expout_ptr
];
358 memcpy (strdata
, str
.ptr
, len
);
359 expout_ptr
+= lenelt
- 2;
360 write_exp_elt_longcst ((LONGEST
) bits
);
363 /* Add the appropriate elements for a minimal symbol to the end of
364 the expression. The rationale behind passing in text_symbol_type and
365 data_symbol_type was so that Modula-2 could pass in WORD for
366 data_symbol_type. Perhaps it still is useful to have those types vary
367 based on the language, but they no longer have names like "int", so
368 the initial rationale is gone. */
370 static struct type
*msym_text_symbol_type
;
371 static struct type
*msym_data_symbol_type
;
372 static struct type
*msym_unknown_symbol_type
;
375 write_exp_msymbol (struct minimal_symbol
*msymbol
,
376 struct type
*text_symbol_type
,
377 struct type
*data_symbol_type
)
381 write_exp_elt_opcode (OP_LONG
);
382 /* Let's make the type big enough to hold a 64-bit address. */
383 write_exp_elt_type (builtin_type_CORE_ADDR
);
385 addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
386 if (overlay_debugging
)
387 addr
= symbol_overlayed_address (addr
, SYMBOL_BFD_SECTION (msymbol
));
388 write_exp_elt_longcst ((LONGEST
) addr
);
390 write_exp_elt_opcode (OP_LONG
);
392 write_exp_elt_opcode (UNOP_MEMVAL
);
393 switch (msymbol
->type
)
397 case mst_solib_trampoline
:
398 write_exp_elt_type (msym_text_symbol_type
);
405 write_exp_elt_type (msym_data_symbol_type
);
409 write_exp_elt_type (msym_unknown_symbol_type
);
412 write_exp_elt_opcode (UNOP_MEMVAL
);
415 /* Recognize tokens that start with '$'. These include:
417 $regname A native register name or a "standard
420 $variable A convenience variable with a name chosen
423 $digits Value history with index <digits>, starting
424 from the first value which has index 1.
426 $$digits Value history with index <digits> relative
427 to the last value. I.E. $$0 is the last
428 value, $$1 is the one previous to that, $$2
429 is the one previous to $$1, etc.
431 $ | $0 | $$0 The last value in the value history.
433 $$ An abbreviation for the second to the last
434 value in the value history, I.E. $$1
439 write_dollar_variable (struct stoken str
)
441 struct symbol
*sym
= NULL
;
442 struct minimal_symbol
*msym
= NULL
;
444 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
445 and $$digits (equivalent to $<-digits> if you could type that). */
449 /* Double dollar means negate the number and add -1 as well.
450 Thus $$ alone means -1. */
451 if (str
.length
>= 2 && str
.ptr
[1] == '$')
458 /* Just dollars (one or two) */
462 /* Is the rest of the token digits? */
463 for (; i
< str
.length
; i
++)
464 if (!(str
.ptr
[i
] >= '0' && str
.ptr
[i
] <= '9'))
468 i
= atoi (str
.ptr
+ 1 + negate
);
474 /* Handle tokens that refer to machine registers:
475 $ followed by a register name. */
476 i
= frame_map_name_to_regnum (deprecated_selected_frame
,
477 str
.ptr
+ 1, str
.length
- 1);
479 goto handle_register
;
481 /* On some systems, such as HP-UX and hppa-linux, certain system routines
482 have names beginning with $ or $$. Check for those, first. */
484 sym
= lookup_symbol (copy_name (str
), (struct block
*) NULL
,
485 VAR_DOMAIN
, (int *) NULL
, (struct symtab
**) NULL
);
488 write_exp_elt_opcode (OP_VAR_VALUE
);
489 write_exp_elt_block (block_found
); /* set by lookup_symbol */
490 write_exp_elt_sym (sym
);
491 write_exp_elt_opcode (OP_VAR_VALUE
);
494 msym
= lookup_minimal_symbol (copy_name (str
), NULL
, NULL
);
497 write_exp_msymbol (msym
,
498 lookup_function_type (builtin_type_int
),
503 /* Any other names starting in $ are debugger internal variables. */
505 write_exp_elt_opcode (OP_INTERNALVAR
);
506 write_exp_elt_intern (lookup_internalvar (copy_name (str
) + 1));
507 write_exp_elt_opcode (OP_INTERNALVAR
);
510 write_exp_elt_opcode (OP_LAST
);
511 write_exp_elt_longcst ((LONGEST
) i
);
512 write_exp_elt_opcode (OP_LAST
);
515 write_exp_elt_opcode (OP_REGISTER
);
516 write_exp_elt_longcst (i
);
517 write_exp_elt_opcode (OP_REGISTER
);
522 /* Parse a string that is possibly a namespace / nested class
523 specification, i.e., something of the form A::B::C::x. Input
524 (NAME) is the entire string; LEN is the current valid length; the
525 output is a string, TOKEN, which points to the largest recognized
526 prefix which is a series of namespaces or classes. CLASS_PREFIX is
527 another output, which records whether a nested class spec was
528 recognized (= 1) or a fully qualified variable name was found (=
529 0). ARGPTR is side-effected (if non-NULL) to point to beyond the
530 string recognized and consumed by this routine.
532 The return value is a pointer to the symbol for the base class or
533 variable if found, or NULL if not found. Callers must check this
534 first -- if NULL, the outputs may not be correct.
536 This function is used c-exp.y. This is used specifically to get
537 around HP aCC (and possibly other compilers), which insists on
538 generating names with embedded colons for namespace or nested class
541 (Argument LEN is currently unused. 1997-08-27)
543 Callers must free memory allocated for the output string TOKEN. */
545 static const char coloncolon
[2] =
549 parse_nested_classes_for_hpacc (char *name
, int len
, char **token
,
550 int *class_prefix
, char **argptr
)
552 /* Comment below comes from decode_line_1 which has very similar
553 code, which is called for "break" command parsing. */
555 /* We have what looks like a class or namespace
556 scope specification (A::B), possibly with many
557 levels of namespaces or classes (A::B::C::D).
559 Some versions of the HP ANSI C++ compiler (as also possibly
560 other compilers) generate class/function/member names with
561 embedded double-colons if they are inside namespaces. To
562 handle this, we loop a few times, considering larger and
563 larger prefixes of the string as though they were single
564 symbols. So, if the initially supplied string is
565 A::B::C::D::foo, we have to look up "A", then "A::B",
566 then "A::B::C", then "A::B::C::D", and finally
567 "A::B::C::D::foo" as single, monolithic symbols, because
568 A, B, C or D may be namespaces.
570 Note that namespaces can nest only inside other
571 namespaces, and not inside classes. So we need only
572 consider *prefixes* of the string; there is no need to look up
573 "B::C" separately as a symbol in the previous example. */
579 struct symbol
*sym_class
= NULL
;
580 struct symbol
*sym_var
= NULL
;
586 /* Check for HP-compiled executable -- in other cases
587 return NULL, and caller must default to standard GDB
590 if (!deprecated_hp_som_som_object_present
)
591 return (struct symbol
*) NULL
;
595 /* Skip over whitespace and possible global "::" */
596 while (*p
&& (*p
== ' ' || *p
== '\t'))
598 if (p
[0] == ':' && p
[1] == ':')
600 while (*p
&& (*p
== ' ' || *p
== '\t'))
605 /* Get to the end of the next namespace or class spec. */
606 /* If we're looking at some non-token, fail immediately */
608 if (!(isalpha (*p
) || *p
== '$' || *p
== '_'))
609 return (struct symbol
*) NULL
;
611 while (*p
&& (isalnum (*p
) || *p
== '$' || *p
== '_'))
616 /* If we have the start of a template specification,
617 scan right ahead to its end */
618 q
= find_template_name_end (p
);
625 /* Skip over "::" and whitespace for next time around */
626 while (*p
&& (*p
== ' ' || *p
== '\t'))
628 if (p
[0] == ':' && p
[1] == ':')
630 while (*p
&& (*p
== ' ' || *p
== '\t'))
633 /* Done with tokens? */
634 if (!*p
|| !(isalpha (*p
) || *p
== '$' || *p
== '_'))
637 tmp
= (char *) alloca (prefix_len
+ end
- start
+ 3);
640 memcpy (tmp
, prefix
, prefix_len
);
641 memcpy (tmp
+ prefix_len
, coloncolon
, 2);
642 memcpy (tmp
+ prefix_len
+ 2, start
, end
- start
);
643 tmp
[prefix_len
+ 2 + end
- start
] = '\000';
647 memcpy (tmp
, start
, end
- start
);
648 tmp
[end
- start
] = '\000';
652 prefix_len
= strlen (prefix
);
654 /* See if the prefix we have now is something we know about */
658 /* More tokens to process, so this must be a class/namespace */
659 sym_class
= lookup_symbol (prefix
, 0, STRUCT_DOMAIN
,
660 0, (struct symtab
**) NULL
);
664 /* No more tokens, so try as a variable first */
665 sym_var
= lookup_symbol (prefix
, 0, VAR_DOMAIN
,
666 0, (struct symtab
**) NULL
);
667 /* If failed, try as class/namespace */
669 sym_class
= lookup_symbol (prefix
, 0, STRUCT_DOMAIN
,
670 0, (struct symtab
**) NULL
);
675 (t
= check_typedef (SYMBOL_TYPE (sym_class
)),
676 (TYPE_CODE (t
) == TYPE_CODE_STRUCT
677 || TYPE_CODE (t
) == TYPE_CODE_UNION
))))
679 /* We found a valid token */
680 *token
= (char *) xmalloc (prefix_len
+ 1);
681 memcpy (*token
, prefix
, prefix_len
);
682 (*token
)[prefix_len
] = '\000';
686 /* No variable or class/namespace found, no more tokens */
688 return (struct symbol
*) NULL
;
691 /* Out of loop, so we must have found a valid token */
698 *argptr
= done
? p
: end
;
700 return sym_var
? sym_var
: sym_class
; /* found */
704 find_template_name_end (char *p
)
707 int just_seen_right
= 0;
708 int just_seen_colon
= 0;
709 int just_seen_space
= 0;
711 if (!p
|| (*p
!= '<'))
722 /* In future, may want to allow these?? */
725 depth
++; /* start nested template */
726 if (just_seen_colon
|| just_seen_right
|| just_seen_space
)
727 return 0; /* but not after : or :: or > or space */
730 if (just_seen_colon
|| just_seen_right
)
731 return 0; /* end a (nested?) template */
732 just_seen_right
= 1; /* but not after : or :: */
733 if (--depth
== 0) /* also disallow >>, insist on > > */
734 return ++p
; /* if outermost ended, return */
737 if (just_seen_space
|| (just_seen_colon
> 1))
738 return 0; /* nested class spec coming up */
739 just_seen_colon
++; /* we allow :: but not :::: */
744 if (!((*p
>= 'a' && *p
<= 'z') || /* allow token chars */
745 (*p
>= 'A' && *p
<= 'Z') ||
746 (*p
>= '0' && *p
<= '9') ||
747 (*p
== '_') || (*p
== ',') || /* commas for template args */
748 (*p
== '&') || (*p
== '*') || /* pointer and ref types */
749 (*p
== '(') || (*p
== ')') || /* function types */
750 (*p
== '[') || (*p
== ']'))) /* array types */
765 /* Return a null-terminated temporary copy of the name
766 of a string token. */
769 copy_name (struct stoken token
)
771 /* Make sure there's enough space for the token. */
772 if (namecopy_size
< token
.length
+ 1)
774 namecopy_size
= token
.length
+ 1;
775 namecopy
= xrealloc (namecopy
, token
.length
+ 1);
778 memcpy (namecopy
, token
.ptr
, token
.length
);
779 namecopy
[token
.length
] = 0;
784 /* Reverse an expression from suffix form (in which it is constructed)
785 to prefix form (in which we can conveniently print or execute it). */
788 prefixify_expression (struct expression
*expr
)
791 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expr
->nelts
);
792 struct expression
*temp
;
793 int inpos
= expr
->nelts
, outpos
= 0;
795 temp
= (struct expression
*) alloca (len
);
797 /* Copy the original expression into temp. */
798 memcpy (temp
, expr
, len
);
800 prefixify_subexp (temp
, expr
, inpos
, outpos
);
803 /* Return the number of exp_elements in the postfix subexpression
804 of EXPR whose operator is at index ENDPOS - 1 in EXPR. */
807 length_of_subexp (struct expression
*expr
, int endpos
)
811 operator_length (expr
, endpos
, &oplen
, &args
);
815 oplen
+= length_of_subexp (expr
, endpos
- oplen
);
822 /* Sets *OPLENP to the length of the operator whose (last) index is
823 ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
827 operator_length (struct expression
*expr
, int endpos
, int *oplenp
, int *argsp
)
829 expr
->language_defn
->la_exp_desc
->operator_length (expr
, endpos
,
833 /* Default value for operator_length in exp_descriptor vectors. */
836 operator_length_standard (struct expression
*expr
, int endpos
,
837 int *oplenp
, int *argsp
)
841 enum f90_range_type range_type
;
845 error (_("?error in operator_length_standard"));
847 i
= (int) expr
->elts
[endpos
- 1].opcode
;
853 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
854 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
877 case OP_F77_UNDETERMINED_ARGLIST
:
879 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
882 case OP_OBJC_MSGCALL
: /* Objective C message (method) call */
884 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
912 case STRUCTOP_STRUCT
:
918 case OP_OBJC_NSSTRING
: /* Objective C Foundation Class NSString constant */
919 case OP_OBJC_SELECTOR
: /* Objective C "@selector" pseudo-op */
922 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
923 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
927 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
928 oplen
= (oplen
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
929 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
);
934 args
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
935 args
-= longest_to_int (expr
->elts
[endpos
- 3].longconst
);
941 case TERNOP_SLICE_COUNT
:
946 case MULTI_SUBSCRIPT
:
948 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
951 case BINOP_ASSIGN_MODIFY
:
965 range_type
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
968 case LOW_BOUND_DEFAULT
:
969 case HIGH_BOUND_DEFAULT
:
972 case BOTH_BOUND_DEFAULT
:
975 case NONE_BOUND_DEFAULT
:
983 args
= 1 + (i
< (int) BINOP_END
);
990 /* Copy the subexpression ending just before index INEND in INEXPR
991 into OUTEXPR, starting at index OUTBEG.
992 In the process, convert it from suffix to prefix form. */
995 prefixify_subexp (struct expression
*inexpr
,
996 struct expression
*outexpr
, int inend
, int outbeg
)
1002 enum exp_opcode opcode
;
1004 operator_length (inexpr
, inend
, &oplen
, &args
);
1006 /* Copy the final operator itself, from the end of the input
1007 to the beginning of the output. */
1009 memcpy (&outexpr
->elts
[outbeg
], &inexpr
->elts
[inend
],
1010 EXP_ELEM_TO_BYTES (oplen
));
1013 /* Find the lengths of the arg subexpressions. */
1014 arglens
= (int *) alloca (args
* sizeof (int));
1015 for (i
= args
- 1; i
>= 0; i
--)
1017 oplen
= length_of_subexp (inexpr
, inend
);
1022 /* Now copy each subexpression, preserving the order of
1023 the subexpressions, but prefixifying each one.
1024 In this loop, inend starts at the beginning of
1025 the expression this level is working on
1026 and marches forward over the arguments.
1027 outbeg does similarly in the output. */
1028 for (i
= 0; i
< args
; i
++)
1032 prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
);
1037 /* This page contains the two entry points to this file. */
1039 /* Read an expression from the string *STRINGPTR points to,
1040 parse it, and return a pointer to a struct expression that we malloc.
1041 Use block BLOCK as the lexical context for variable names;
1042 if BLOCK is zero, use the block of the selected stack frame.
1043 Meanwhile, advance *STRINGPTR to point after the expression,
1044 at the first nonwhite character that is not part of the expression
1045 (possibly a null character).
1047 If COMMA is nonzero, stop if a comma is reached. */
1050 parse_exp_1 (char **stringptr
, struct block
*block
, int comma
)
1052 return parse_exp_in_context (stringptr
, block
, comma
, 0);
1055 /* As for parse_exp_1, except that if VOID_CONTEXT_P, then
1056 no value is expected from the expression. */
1058 static struct expression
*
1059 parse_exp_in_context (char **stringptr
, struct block
*block
, int comma
,
1062 struct cleanup
*old_chain
;
1064 lexptr
= *stringptr
;
1068 type_stack_depth
= 0;
1070 comma_terminates
= comma
;
1072 if (lexptr
== 0 || *lexptr
== 0)
1073 error_no_arg (_("expression to compute"));
1075 old_chain
= make_cleanup (free_funcalls
, 0 /*ignore*/);
1080 expression_context_block
= block
;
1081 expression_context_pc
= BLOCK_START (block
);
1084 expression_context_block
= get_selected_block (&expression_context_pc
);
1088 expout
= (struct expression
*)
1089 xmalloc (sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_size
));
1090 expout
->language_defn
= current_language
;
1091 make_cleanup (free_current_contents
, &expout
);
1093 if (current_language
->la_parser ())
1094 current_language
->la_error (NULL
);
1096 discard_cleanups (old_chain
);
1098 /* Record the actual number of expression elements, and then
1099 reallocate the expression memory so that we free up any
1102 expout
->nelts
= expout_ptr
;
1103 expout
= (struct expression
*)
1104 xrealloc ((char *) expout
,
1105 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_ptr
));;
1107 /* Convert expression from postfix form as generated by yacc
1108 parser, to a prefix form. */
1110 if (expressiondebug
)
1111 dump_raw_expression (expout
, gdb_stdlog
,
1112 "before conversion to prefix form");
1114 prefixify_expression (expout
);
1116 current_language
->la_post_parser (&expout
, void_context_p
);
1118 if (expressiondebug
)
1119 dump_prefix_expression (expout
, gdb_stdlog
);
1121 *stringptr
= lexptr
;
1125 /* Parse STRING as an expression, and complain if this fails
1126 to use up all of the contents of STRING. */
1129 parse_expression (char *string
)
1131 struct expression
*exp
;
1132 exp
= parse_exp_1 (&string
, 0, 0);
1134 error (_("Junk after end of expression."));
1139 /* As for parse_expression, except that if VOID_CONTEXT_P, then
1140 no value is expected from the expression. */
1143 parse_expression_in_context (char *string
, int void_context_p
)
1145 struct expression
*exp
;
1146 exp
= parse_exp_in_context (&string
, 0, 0, void_context_p
);
1147 if (*string
!= '\000')
1148 error (_("Junk after end of expression."));
1152 /* A post-parser that does nothing */
1155 null_post_parser (struct expression
**exp
, int void_context_p
)
1159 /* Stuff for maintaining a stack of types. Currently just used by C, but
1160 probably useful for any language which declares its types "backwards". */
1163 check_type_stack_depth (void)
1165 if (type_stack_depth
== type_stack_size
)
1167 type_stack_size
*= 2;
1168 type_stack
= (union type_stack_elt
*)
1169 xrealloc ((char *) type_stack
, type_stack_size
* sizeof (*type_stack
));
1174 push_type (enum type_pieces tp
)
1176 check_type_stack_depth ();
1177 type_stack
[type_stack_depth
++].piece
= tp
;
1181 push_type_int (int n
)
1183 check_type_stack_depth ();
1184 type_stack
[type_stack_depth
++].int_val
= n
;
1188 push_type_address_space (char *string
)
1190 push_type_int (address_space_name_to_int (string
));
1196 if (type_stack_depth
)
1197 return type_stack
[--type_stack_depth
].piece
;
1204 if (type_stack_depth
)
1205 return type_stack
[--type_stack_depth
].int_val
;
1206 /* "Can't happen". */
1210 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1211 as modified by all the stuff on the stack. */
1213 follow_types (struct type
*follow_type
)
1217 int make_volatile
= 0;
1218 int make_addr_space
= 0;
1220 struct type
*range_type
;
1223 switch (pop_type ())
1228 follow_type
= make_cv_type (make_const
,
1229 TYPE_VOLATILE (follow_type
),
1232 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1235 if (make_addr_space
)
1236 follow_type
= make_type_with_address_space (follow_type
,
1238 make_const
= make_volatile
= 0;
1239 make_addr_space
= 0;
1247 case tp_space_identifier
:
1248 make_addr_space
= pop_type_int ();
1251 follow_type
= lookup_pointer_type (follow_type
);
1253 follow_type
= make_cv_type (make_const
,
1254 TYPE_VOLATILE (follow_type
),
1257 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1260 if (make_addr_space
)
1261 follow_type
= make_type_with_address_space (follow_type
,
1263 make_const
= make_volatile
= 0;
1264 make_addr_space
= 0;
1267 follow_type
= lookup_reference_type (follow_type
);
1269 follow_type
= make_cv_type (make_const
,
1270 TYPE_VOLATILE (follow_type
),
1273 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1276 if (make_addr_space
)
1277 follow_type
= make_type_with_address_space (follow_type
,
1279 make_const
= make_volatile
= 0;
1280 make_addr_space
= 0;
1283 array_size
= pop_type_int ();
1284 /* FIXME-type-allocation: need a way to free this type when we are
1287 create_range_type ((struct type
*) NULL
,
1288 builtin_type_int
, 0,
1289 array_size
>= 0 ? array_size
- 1 : 0);
1291 create_array_type ((struct type
*) NULL
,
1292 follow_type
, range_type
);
1294 TYPE_ARRAY_UPPER_BOUND_TYPE (follow_type
)
1295 = BOUND_CANNOT_BE_DETERMINED
;
1298 /* FIXME-type-allocation: need a way to free this type when we are
1300 follow_type
= lookup_function_type (follow_type
);
1306 static void build_parse (void);
1312 msym_text_symbol_type
=
1313 init_type (TYPE_CODE_FUNC
, 1, 0, "<text variable, no debug info>", NULL
);
1314 TYPE_TARGET_TYPE (msym_text_symbol_type
) = builtin_type_int
;
1315 msym_data_symbol_type
=
1316 init_type (TYPE_CODE_INT
, TARGET_INT_BIT
/ HOST_CHAR_BIT
, 0,
1317 "<data variable, no debug info>", NULL
);
1318 msym_unknown_symbol_type
=
1319 init_type (TYPE_CODE_INT
, 1, 0,
1320 "<variable (not text or data), no debug info>",
1324 /* This function avoids direct calls to fprintf
1325 in the parser generated debug code. */
1327 parser_fprintf (FILE *x
, const char *y
, ...)
1332 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1335 fprintf_unfiltered (gdb_stderr
, " Unknown FILE used.\n");
1336 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1342 _initialize_parse (void)
1344 type_stack_size
= 80;
1345 type_stack_depth
= 0;
1346 type_stack
= (union type_stack_elt
*)
1347 xmalloc (type_stack_size
* sizeof (*type_stack
));
1351 /* FIXME - For the moment, handle types by swapping them in and out.
1352 Should be using the per-architecture data-pointer and a large
1354 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_text_symbol_type
);
1355 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_data_symbol_type
);
1356 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_unknown_symbol_type
);
1357 deprecated_register_gdbarch_swap (NULL
, 0, build_parse
);
1359 add_setshow_zinteger_cmd ("expression", class_maintenance
,
1360 &expressiondebug
, _("\
1361 Set expression debugging."), _("\
1362 Show expression debugging."), _("\
1363 When non-zero, the internal representation of expressions will be printed."),
1365 show_expressiondebug
,
1366 &setdebuglist
, &showdebuglist
);