1 /* Parse expressions for GDB.
3 Copyright 1986, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996,
4 1997, 1998, 1999, 2000, 2001, 2004 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., 59 Temple Place - Suite 330,
24 Boston, MA 02111-1307, 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"
46 #include "parser-defs.h"
48 #include "symfile.h" /* for overlay functions */
49 #include "inferior.h" /* for NUM_PSEUDO_REGS. NOTE: replace
50 with "gdbarch.h" when appropriate. */
52 #include "gdb_assert.h"
55 /* Standard set of definitions for printing, dumping, prefixifying,
56 * and evaluating expressions. */
58 const struct exp_descriptor exp_descriptor_standard
=
60 print_subexp_standard
,
61 operator_length_standard
,
63 dump_subexp_body_standard
,
64 evaluate_subexp_standard
67 /* Global variables declared in parser-defs.h (and commented there). */
68 struct expression
*expout
;
71 struct block
*expression_context_block
;
72 CORE_ADDR expression_context_pc
;
73 struct block
*innermost_block
;
75 union type_stack_elt
*type_stack
;
76 int type_stack_depth
, type_stack_size
;
83 static int expressiondebug
= 0;
85 show_expressiondebug (struct ui_file
*file
, int from_tty
,
86 struct cmd_list_element
*c
, const char *value
)
88 fprintf_filtered (file
, _("Expression debugging is %s.\n"), value
);
91 static void free_funcalls (void *ignore
);
93 static void prefixify_expression (struct expression
*);
95 static void prefixify_subexp (struct expression
*, struct expression
*, int,
98 static struct expression
*parse_exp_in_context (char **, struct block
*, int,
101 void _initialize_parse (void);
103 /* Data structure for saving values of arglist_len for function calls whose
104 arguments contain other function calls. */
108 struct funcall
*next
;
112 static struct funcall
*funcall_chain
;
114 /* Begin counting arguments for a function call,
115 saving the data about any containing call. */
122 new = (struct funcall
*) xmalloc (sizeof (struct funcall
));
123 new->next
= funcall_chain
;
124 new->arglist_len
= arglist_len
;
129 /* Return the number of arguments in a function call just terminated,
130 and restore the data for the containing function call. */
135 int val
= arglist_len
;
136 struct funcall
*call
= funcall_chain
;
137 funcall_chain
= call
->next
;
138 arglist_len
= call
->arglist_len
;
143 /* Free everything in the funcall chain.
144 Used when there is an error inside parsing. */
147 free_funcalls (void *ignore
)
149 struct funcall
*call
, *next
;
151 for (call
= funcall_chain
; call
; call
= next
)
158 /* This page contains the functions for adding data to the struct expression
159 being constructed. */
161 /* Add one element to the end of the expression. */
163 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
164 a register through here */
167 write_exp_elt (union exp_element expelt
)
169 if (expout_ptr
>= expout_size
)
172 expout
= (struct expression
*)
173 xrealloc ((char *) expout
, sizeof (struct expression
)
174 + EXP_ELEM_TO_BYTES (expout_size
));
176 expout
->elts
[expout_ptr
++] = expelt
;
180 write_exp_elt_opcode (enum exp_opcode expelt
)
182 union exp_element tmp
;
190 write_exp_elt_sym (struct symbol
*expelt
)
192 union exp_element tmp
;
200 write_exp_elt_block (struct block
*b
)
202 union exp_element tmp
;
208 write_exp_elt_longcst (LONGEST expelt
)
210 union exp_element tmp
;
212 tmp
.longconst
= expelt
;
218 write_exp_elt_dblcst (DOUBLEST expelt
)
220 union exp_element tmp
;
222 tmp
.doubleconst
= expelt
;
228 write_exp_elt_type (struct type
*expelt
)
230 union exp_element tmp
;
238 write_exp_elt_intern (struct internalvar
*expelt
)
240 union exp_element tmp
;
242 tmp
.internalvar
= expelt
;
247 /* Add a string constant to the end of the expression.
249 String constants are stored by first writing an expression element
250 that contains the length of the string, then stuffing the string
251 constant itself into however many expression elements are needed
252 to hold it, and then writing another expression element that contains
253 the length of the string. I.E. an expression element at each end of
254 the string records the string length, so you can skip over the
255 expression elements containing the actual string bytes from either
256 end of the string. Note that this also allows gdb to handle
257 strings with embedded null bytes, as is required for some languages.
259 Don't be fooled by the fact that the string is null byte terminated,
260 this is strictly for the convenience of debugging gdb itself. Gdb
261 Gdb does not depend up the string being null terminated, since the
262 actual length is recorded in expression elements at each end of the
263 string. The null byte is taken into consideration when computing how
264 many expression elements are required to hold the string constant, of
269 write_exp_string (struct stoken str
)
271 int len
= str
.length
;
275 /* Compute the number of expression elements required to hold the string
276 (including a null byte terminator), along with one expression element
277 at each end to record the actual string length (not including the
278 null byte terminator). */
280 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
+ 1);
282 /* Ensure that we have enough available expression elements to store
285 if ((expout_ptr
+ lenelt
) >= expout_size
)
287 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
288 expout
= (struct expression
*)
289 xrealloc ((char *) expout
, (sizeof (struct expression
)
290 + EXP_ELEM_TO_BYTES (expout_size
)));
293 /* Write the leading length expression element (which advances the current
294 expression element index), then write the string constant followed by a
295 terminating null byte, and then write the trailing length expression
298 write_exp_elt_longcst ((LONGEST
) len
);
299 strdata
= (char *) &expout
->elts
[expout_ptr
];
300 memcpy (strdata
, str
.ptr
, len
);
301 *(strdata
+ len
) = '\0';
302 expout_ptr
+= lenelt
- 2;
303 write_exp_elt_longcst ((LONGEST
) len
);
306 /* Add a bitstring constant to the end of the expression.
308 Bitstring constants are stored by first writing an expression element
309 that contains the length of the bitstring (in bits), then stuffing the
310 bitstring constant itself into however many expression elements are
311 needed to hold it, and then writing another expression element that
312 contains the length of the bitstring. I.E. an expression element at
313 each end of the bitstring records the bitstring length, so you can skip
314 over the expression elements containing the actual bitstring bytes from
315 either end of the bitstring. */
318 write_exp_bitstring (struct stoken str
)
320 int bits
= str
.length
; /* length in bits */
321 int len
= (bits
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
325 /* Compute the number of expression elements required to hold the bitstring,
326 along with one expression element at each end to record the actual
327 bitstring length in bits. */
329 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
);
331 /* Ensure that we have enough available expression elements to store
334 if ((expout_ptr
+ lenelt
) >= expout_size
)
336 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
337 expout
= (struct expression
*)
338 xrealloc ((char *) expout
, (sizeof (struct expression
)
339 + EXP_ELEM_TO_BYTES (expout_size
)));
342 /* Write the leading length expression element (which advances the current
343 expression element index), then write the bitstring constant, and then
344 write the trailing length expression element. */
346 write_exp_elt_longcst ((LONGEST
) bits
);
347 strdata
= (char *) &expout
->elts
[expout_ptr
];
348 memcpy (strdata
, str
.ptr
, len
);
349 expout_ptr
+= lenelt
- 2;
350 write_exp_elt_longcst ((LONGEST
) bits
);
353 /* Add the appropriate elements for a minimal symbol to the end of
354 the expression. The rationale behind passing in text_symbol_type and
355 data_symbol_type was so that Modula-2 could pass in WORD for
356 data_symbol_type. Perhaps it still is useful to have those types vary
357 based on the language, but they no longer have names like "int", so
358 the initial rationale is gone. */
360 static struct type
*msym_text_symbol_type
;
361 static struct type
*msym_data_symbol_type
;
362 static struct type
*msym_unknown_symbol_type
;
365 write_exp_msymbol (struct minimal_symbol
*msymbol
,
366 struct type
*text_symbol_type
,
367 struct type
*data_symbol_type
)
371 write_exp_elt_opcode (OP_LONG
);
372 /* Let's make the type big enough to hold a 64-bit address. */
373 write_exp_elt_type (builtin_type_CORE_ADDR
);
375 addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
376 if (overlay_debugging
)
377 addr
= symbol_overlayed_address (addr
, SYMBOL_BFD_SECTION (msymbol
));
378 write_exp_elt_longcst ((LONGEST
) addr
);
380 write_exp_elt_opcode (OP_LONG
);
382 write_exp_elt_opcode (UNOP_MEMVAL
);
383 switch (msymbol
->type
)
387 case mst_solib_trampoline
:
388 write_exp_elt_type (msym_text_symbol_type
);
395 write_exp_elt_type (msym_data_symbol_type
);
399 write_exp_elt_type (msym_unknown_symbol_type
);
402 write_exp_elt_opcode (UNOP_MEMVAL
);
405 /* Recognize tokens that start with '$'. These include:
407 $regname A native register name or a "standard
410 $variable A convenience variable with a name chosen
413 $digits Value history with index <digits>, starting
414 from the first value which has index 1.
416 $$digits Value history with index <digits> relative
417 to the last value. I.E. $$0 is the last
418 value, $$1 is the one previous to that, $$2
419 is the one previous to $$1, etc.
421 $ | $0 | $$0 The last value in the value history.
423 $$ An abbreviation for the second to the last
424 value in the value history, I.E. $$1
429 write_dollar_variable (struct stoken str
)
431 struct symbol
*sym
= NULL
;
432 struct minimal_symbol
*msym
= NULL
;
434 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
435 and $$digits (equivalent to $<-digits> if you could type that). */
439 /* Double dollar means negate the number and add -1 as well.
440 Thus $$ alone means -1. */
441 if (str
.length
>= 2 && str
.ptr
[1] == '$')
448 /* Just dollars (one or two) */
452 /* Is the rest of the token digits? */
453 for (; i
< str
.length
; i
++)
454 if (!(str
.ptr
[i
] >= '0' && str
.ptr
[i
] <= '9'))
458 i
= atoi (str
.ptr
+ 1 + negate
);
464 /* Handle tokens that refer to machine registers:
465 $ followed by a register name. */
466 i
= frame_map_name_to_regnum (deprecated_selected_frame
,
467 str
.ptr
+ 1, str
.length
- 1);
469 goto handle_register
;
471 /* On some systems, such as HP-UX and hppa-linux, certain system routines
472 have names beginning with $ or $$. Check for those, first. */
474 sym
= lookup_symbol (copy_name (str
), (struct block
*) NULL
,
475 VAR_DOMAIN
, (int *) NULL
, (struct symtab
**) NULL
);
478 write_exp_elt_opcode (OP_VAR_VALUE
);
479 write_exp_elt_block (block_found
); /* set by lookup_symbol */
480 write_exp_elt_sym (sym
);
481 write_exp_elt_opcode (OP_VAR_VALUE
);
484 msym
= lookup_minimal_symbol (copy_name (str
), NULL
, NULL
);
487 write_exp_msymbol (msym
,
488 lookup_function_type (builtin_type_int
),
493 /* Any other names starting in $ are debugger internal variables. */
495 write_exp_elt_opcode (OP_INTERNALVAR
);
496 write_exp_elt_intern (lookup_internalvar (copy_name (str
) + 1));
497 write_exp_elt_opcode (OP_INTERNALVAR
);
500 write_exp_elt_opcode (OP_LAST
);
501 write_exp_elt_longcst ((LONGEST
) i
);
502 write_exp_elt_opcode (OP_LAST
);
505 write_exp_elt_opcode (OP_REGISTER
);
506 write_exp_elt_longcst (i
);
507 write_exp_elt_opcode (OP_REGISTER
);
512 /* Parse a string that is possibly a namespace / nested class
513 specification, i.e., something of the form A::B::C::x. Input
514 (NAME) is the entire string; LEN is the current valid length; the
515 output is a string, TOKEN, which points to the largest recognized
516 prefix which is a series of namespaces or classes. CLASS_PREFIX is
517 another output, which records whether a nested class spec was
518 recognized (= 1) or a fully qualified variable name was found (=
519 0). ARGPTR is side-effected (if non-NULL) to point to beyond the
520 string recognized and consumed by this routine.
522 The return value is a pointer to the symbol for the base class or
523 variable if found, or NULL if not found. Callers must check this
524 first -- if NULL, the outputs may not be correct.
526 This function is used c-exp.y. This is used specifically to get
527 around HP aCC (and possibly other compilers), which insists on
528 generating names with embedded colons for namespace or nested class
531 (Argument LEN is currently unused. 1997-08-27)
533 Callers must free memory allocated for the output string TOKEN. */
535 static const char coloncolon
[2] =
539 parse_nested_classes_for_hpacc (char *name
, int len
, char **token
,
540 int *class_prefix
, char **argptr
)
542 /* Comment below comes from decode_line_1 which has very similar
543 code, which is called for "break" command parsing. */
545 /* We have what looks like a class or namespace
546 scope specification (A::B), possibly with many
547 levels of namespaces or classes (A::B::C::D).
549 Some versions of the HP ANSI C++ compiler (as also possibly
550 other compilers) generate class/function/member names with
551 embedded double-colons if they are inside namespaces. To
552 handle this, we loop a few times, considering larger and
553 larger prefixes of the string as though they were single
554 symbols. So, if the initially supplied string is
555 A::B::C::D::foo, we have to look up "A", then "A::B",
556 then "A::B::C", then "A::B::C::D", and finally
557 "A::B::C::D::foo" as single, monolithic symbols, because
558 A, B, C or D may be namespaces.
560 Note that namespaces can nest only inside other
561 namespaces, and not inside classes. So we need only
562 consider *prefixes* of the string; there is no need to look up
563 "B::C" separately as a symbol in the previous example. */
569 struct symbol
*sym_class
= NULL
;
570 struct symbol
*sym_var
= NULL
;
576 /* Check for HP-compiled executable -- in other cases
577 return NULL, and caller must default to standard GDB
580 if (!deprecated_hp_som_som_object_present
)
581 return (struct symbol
*) NULL
;
585 /* Skip over whitespace and possible global "::" */
586 while (*p
&& (*p
== ' ' || *p
== '\t'))
588 if (p
[0] == ':' && p
[1] == ':')
590 while (*p
&& (*p
== ' ' || *p
== '\t'))
595 /* Get to the end of the next namespace or class spec. */
596 /* If we're looking at some non-token, fail immediately */
598 if (!(isalpha (*p
) || *p
== '$' || *p
== '_'))
599 return (struct symbol
*) NULL
;
601 while (*p
&& (isalnum (*p
) || *p
== '$' || *p
== '_'))
606 /* If we have the start of a template specification,
607 scan right ahead to its end */
608 q
= find_template_name_end (p
);
615 /* Skip over "::" and whitespace for next time around */
616 while (*p
&& (*p
== ' ' || *p
== '\t'))
618 if (p
[0] == ':' && p
[1] == ':')
620 while (*p
&& (*p
== ' ' || *p
== '\t'))
623 /* Done with tokens? */
624 if (!*p
|| !(isalpha (*p
) || *p
== '$' || *p
== '_'))
627 tmp
= (char *) alloca (prefix_len
+ end
- start
+ 3);
630 memcpy (tmp
, prefix
, prefix_len
);
631 memcpy (tmp
+ prefix_len
, coloncolon
, 2);
632 memcpy (tmp
+ prefix_len
+ 2, start
, end
- start
);
633 tmp
[prefix_len
+ 2 + end
- start
] = '\000';
637 memcpy (tmp
, start
, end
- start
);
638 tmp
[end
- start
] = '\000';
642 prefix_len
= strlen (prefix
);
644 /* See if the prefix we have now is something we know about */
648 /* More tokens to process, so this must be a class/namespace */
649 sym_class
= lookup_symbol (prefix
, 0, STRUCT_DOMAIN
,
650 0, (struct symtab
**) NULL
);
654 /* No more tokens, so try as a variable first */
655 sym_var
= lookup_symbol (prefix
, 0, VAR_DOMAIN
,
656 0, (struct symtab
**) NULL
);
657 /* If failed, try as class/namespace */
659 sym_class
= lookup_symbol (prefix
, 0, STRUCT_DOMAIN
,
660 0, (struct symtab
**) NULL
);
665 (t
= check_typedef (SYMBOL_TYPE (sym_class
)),
666 (TYPE_CODE (t
) == TYPE_CODE_STRUCT
667 || TYPE_CODE (t
) == TYPE_CODE_UNION
))))
669 /* We found a valid token */
670 *token
= (char *) xmalloc (prefix_len
+ 1);
671 memcpy (*token
, prefix
, prefix_len
);
672 (*token
)[prefix_len
] = '\000';
676 /* No variable or class/namespace found, no more tokens */
678 return (struct symbol
*) NULL
;
681 /* Out of loop, so we must have found a valid token */
688 *argptr
= done
? p
: end
;
690 return sym_var
? sym_var
: sym_class
; /* found */
694 find_template_name_end (char *p
)
697 int just_seen_right
= 0;
698 int just_seen_colon
= 0;
699 int just_seen_space
= 0;
701 if (!p
|| (*p
!= '<'))
712 /* In future, may want to allow these?? */
715 depth
++; /* start nested template */
716 if (just_seen_colon
|| just_seen_right
|| just_seen_space
)
717 return 0; /* but not after : or :: or > or space */
720 if (just_seen_colon
|| just_seen_right
)
721 return 0; /* end a (nested?) template */
722 just_seen_right
= 1; /* but not after : or :: */
723 if (--depth
== 0) /* also disallow >>, insist on > > */
724 return ++p
; /* if outermost ended, return */
727 if (just_seen_space
|| (just_seen_colon
> 1))
728 return 0; /* nested class spec coming up */
729 just_seen_colon
++; /* we allow :: but not :::: */
734 if (!((*p
>= 'a' && *p
<= 'z') || /* allow token chars */
735 (*p
>= 'A' && *p
<= 'Z') ||
736 (*p
>= '0' && *p
<= '9') ||
737 (*p
== '_') || (*p
== ',') || /* commas for template args */
738 (*p
== '&') || (*p
== '*') || /* pointer and ref types */
739 (*p
== '(') || (*p
== ')') || /* function types */
740 (*p
== '[') || (*p
== ']'))) /* array types */
755 /* Return a null-terminated temporary copy of the name
756 of a string token. */
759 copy_name (struct stoken token
)
761 memcpy (namecopy
, token
.ptr
, token
.length
);
762 namecopy
[token
.length
] = 0;
766 /* Reverse an expression from suffix form (in which it is constructed)
767 to prefix form (in which we can conveniently print or execute it). */
770 prefixify_expression (struct expression
*expr
)
773 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expr
->nelts
);
774 struct expression
*temp
;
775 int inpos
= expr
->nelts
, outpos
= 0;
777 temp
= (struct expression
*) alloca (len
);
779 /* Copy the original expression into temp. */
780 memcpy (temp
, expr
, len
);
782 prefixify_subexp (temp
, expr
, inpos
, outpos
);
785 /* Return the number of exp_elements in the postfix subexpression
786 of EXPR whose operator is at index ENDPOS - 1 in EXPR. */
789 length_of_subexp (struct expression
*expr
, int endpos
)
793 operator_length (expr
, endpos
, &oplen
, &args
);
797 oplen
+= length_of_subexp (expr
, endpos
- oplen
);
804 /* Sets *OPLENP to the length of the operator whose (last) index is
805 ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
809 operator_length (struct expression
*expr
, int endpos
, int *oplenp
, int *argsp
)
811 expr
->language_defn
->la_exp_desc
->operator_length (expr
, endpos
,
815 /* Default value for operator_length in exp_descriptor vectors. */
818 operator_length_standard (struct expression
*expr
, int endpos
,
819 int *oplenp
, int *argsp
)
826 error (_("?error in operator_length_standard"));
828 i
= (int) expr
->elts
[endpos
- 1].opcode
;
834 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
835 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
858 case OP_F77_UNDETERMINED_ARGLIST
:
860 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
863 case OP_OBJC_MSGCALL
: /* Objective C message (method) call */
865 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
893 case STRUCTOP_STRUCT
:
899 case OP_OBJC_NSSTRING
: /* Objective C Foundation Class NSString constant */
900 case OP_OBJC_SELECTOR
: /* Objective C "@selector" pseudo-op */
903 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
904 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
908 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
909 oplen
= (oplen
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
910 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
);
915 args
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
916 args
-= longest_to_int (expr
->elts
[endpos
- 3].longconst
);
922 case TERNOP_SLICE_COUNT
:
927 case MULTI_SUBSCRIPT
:
929 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
932 case BINOP_ASSIGN_MODIFY
:
944 args
= 1 + (i
< (int) BINOP_END
);
951 /* Copy the subexpression ending just before index INEND in INEXPR
952 into OUTEXPR, starting at index OUTBEG.
953 In the process, convert it from suffix to prefix form. */
956 prefixify_subexp (struct expression
*inexpr
,
957 struct expression
*outexpr
, int inend
, int outbeg
)
963 enum exp_opcode opcode
;
965 operator_length (inexpr
, inend
, &oplen
, &args
);
967 /* Copy the final operator itself, from the end of the input
968 to the beginning of the output. */
970 memcpy (&outexpr
->elts
[outbeg
], &inexpr
->elts
[inend
],
971 EXP_ELEM_TO_BYTES (oplen
));
974 /* Find the lengths of the arg subexpressions. */
975 arglens
= (int *) alloca (args
* sizeof (int));
976 for (i
= args
- 1; i
>= 0; i
--)
978 oplen
= length_of_subexp (inexpr
, inend
);
983 /* Now copy each subexpression, preserving the order of
984 the subexpressions, but prefixifying each one.
985 In this loop, inend starts at the beginning of
986 the expression this level is working on
987 and marches forward over the arguments.
988 outbeg does similarly in the output. */
989 for (i
= 0; i
< args
; i
++)
993 prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
);
998 /* This page contains the two entry points to this file. */
1000 /* Read an expression from the string *STRINGPTR points to,
1001 parse it, and return a pointer to a struct expression that we malloc.
1002 Use block BLOCK as the lexical context for variable names;
1003 if BLOCK is zero, use the block of the selected stack frame.
1004 Meanwhile, advance *STRINGPTR to point after the expression,
1005 at the first nonwhite character that is not part of the expression
1006 (possibly a null character).
1008 If COMMA is nonzero, stop if a comma is reached. */
1011 parse_exp_1 (char **stringptr
, struct block
*block
, int comma
)
1013 return parse_exp_in_context (stringptr
, block
, comma
, 0);
1016 /* As for parse_exp_1, except that if VOID_CONTEXT_P, then
1017 no value is expected from the expression. */
1019 static struct expression
*
1020 parse_exp_in_context (char **stringptr
, struct block
*block
, int comma
,
1023 struct cleanup
*old_chain
;
1025 lexptr
= *stringptr
;
1029 type_stack_depth
= 0;
1031 comma_terminates
= comma
;
1033 if (lexptr
== 0 || *lexptr
== 0)
1034 error_no_arg (_("expression to compute"));
1036 old_chain
= make_cleanup (free_funcalls
, 0 /*ignore*/);
1041 expression_context_block
= block
;
1042 expression_context_pc
= BLOCK_START (block
);
1045 expression_context_block
= get_selected_block (&expression_context_pc
);
1047 namecopy
= (char *) alloca (strlen (lexptr
) + 1);
1050 expout
= (struct expression
*)
1051 xmalloc (sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_size
));
1052 expout
->language_defn
= current_language
;
1053 make_cleanup (free_current_contents
, &expout
);
1055 if (current_language
->la_parser ())
1056 current_language
->la_error (NULL
);
1058 discard_cleanups (old_chain
);
1060 /* Record the actual number of expression elements, and then
1061 reallocate the expression memory so that we free up any
1064 expout
->nelts
= expout_ptr
;
1065 expout
= (struct expression
*)
1066 xrealloc ((char *) expout
,
1067 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_ptr
));;
1069 /* Convert expression from postfix form as generated by yacc
1070 parser, to a prefix form. */
1072 if (expressiondebug
)
1073 dump_raw_expression (expout
, gdb_stdlog
,
1074 "before conversion to prefix form");
1076 prefixify_expression (expout
);
1078 current_language
->la_post_parser (&expout
, void_context_p
);
1080 if (expressiondebug
)
1081 dump_prefix_expression (expout
, gdb_stdlog
);
1083 *stringptr
= lexptr
;
1087 /* Parse STRING as an expression, and complain if this fails
1088 to use up all of the contents of STRING. */
1091 parse_expression (char *string
)
1093 struct expression
*exp
;
1094 exp
= parse_exp_1 (&string
, 0, 0);
1096 error (_("Junk after end of expression."));
1101 /* As for parse_expression, except that if VOID_CONTEXT_P, then
1102 no value is expected from the expression. */
1105 parse_expression_in_context (char *string
, int void_context_p
)
1107 struct expression
*exp
;
1108 exp
= parse_exp_in_context (&string
, 0, 0, void_context_p
);
1109 if (*string
!= '\000')
1110 error (_("Junk after end of expression."));
1114 /* A post-parser that does nothing */
1117 null_post_parser (struct expression
**exp
, int void_context_p
)
1121 /* Stuff for maintaining a stack of types. Currently just used by C, but
1122 probably useful for any language which declares its types "backwards". */
1125 check_type_stack_depth (void)
1127 if (type_stack_depth
== type_stack_size
)
1129 type_stack_size
*= 2;
1130 type_stack
= (union type_stack_elt
*)
1131 xrealloc ((char *) type_stack
, type_stack_size
* sizeof (*type_stack
));
1136 push_type (enum type_pieces tp
)
1138 check_type_stack_depth ();
1139 type_stack
[type_stack_depth
++].piece
= tp
;
1143 push_type_int (int n
)
1145 check_type_stack_depth ();
1146 type_stack
[type_stack_depth
++].int_val
= n
;
1150 push_type_address_space (char *string
)
1152 push_type_int (address_space_name_to_int (string
));
1158 if (type_stack_depth
)
1159 return type_stack
[--type_stack_depth
].piece
;
1166 if (type_stack_depth
)
1167 return type_stack
[--type_stack_depth
].int_val
;
1168 /* "Can't happen". */
1172 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1173 as modified by all the stuff on the stack. */
1175 follow_types (struct type
*follow_type
)
1179 int make_volatile
= 0;
1180 int make_addr_space
= 0;
1182 struct type
*range_type
;
1185 switch (pop_type ())
1190 follow_type
= make_cv_type (make_const
,
1191 TYPE_VOLATILE (follow_type
),
1194 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1197 if (make_addr_space
)
1198 follow_type
= make_type_with_address_space (follow_type
,
1200 make_const
= make_volatile
= 0;
1201 make_addr_space
= 0;
1209 case tp_space_identifier
:
1210 make_addr_space
= pop_type_int ();
1213 follow_type
= lookup_pointer_type (follow_type
);
1215 follow_type
= make_cv_type (make_const
,
1216 TYPE_VOLATILE (follow_type
),
1219 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1222 if (make_addr_space
)
1223 follow_type
= make_type_with_address_space (follow_type
,
1225 make_const
= make_volatile
= 0;
1226 make_addr_space
= 0;
1229 follow_type
= lookup_reference_type (follow_type
);
1231 follow_type
= make_cv_type (make_const
,
1232 TYPE_VOLATILE (follow_type
),
1235 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1238 if (make_addr_space
)
1239 follow_type
= make_type_with_address_space (follow_type
,
1241 make_const
= make_volatile
= 0;
1242 make_addr_space
= 0;
1245 array_size
= pop_type_int ();
1246 /* FIXME-type-allocation: need a way to free this type when we are
1249 create_range_type ((struct type
*) NULL
,
1250 builtin_type_int
, 0,
1251 array_size
>= 0 ? array_size
- 1 : 0);
1253 create_array_type ((struct type
*) NULL
,
1254 follow_type
, range_type
);
1256 TYPE_ARRAY_UPPER_BOUND_TYPE (follow_type
)
1257 = BOUND_CANNOT_BE_DETERMINED
;
1260 /* FIXME-type-allocation: need a way to free this type when we are
1262 follow_type
= lookup_function_type (follow_type
);
1268 static void build_parse (void);
1274 msym_text_symbol_type
=
1275 init_type (TYPE_CODE_FUNC
, 1, 0, "<text variable, no debug info>", NULL
);
1276 TYPE_TARGET_TYPE (msym_text_symbol_type
) = builtin_type_int
;
1277 msym_data_symbol_type
=
1278 init_type (TYPE_CODE_INT
, TARGET_INT_BIT
/ HOST_CHAR_BIT
, 0,
1279 "<data variable, no debug info>", NULL
);
1280 msym_unknown_symbol_type
=
1281 init_type (TYPE_CODE_INT
, 1, 0,
1282 "<variable (not text or data), no debug info>",
1286 /* This function avoids direct calls to fprintf
1287 in the parser generated debug code. */
1289 parser_fprintf (FILE *x
, const char *y
, ...)
1294 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1297 fprintf_unfiltered (gdb_stderr
, " Unknown FILE used.\n");
1298 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1304 _initialize_parse (void)
1306 type_stack_size
= 80;
1307 type_stack_depth
= 0;
1308 type_stack
= (union type_stack_elt
*)
1309 xmalloc (type_stack_size
* sizeof (*type_stack
));
1313 /* FIXME - For the moment, handle types by swapping them in and out.
1314 Should be using the per-architecture data-pointer and a large
1316 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_text_symbol_type
);
1317 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_data_symbol_type
);
1318 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_unknown_symbol_type
);
1319 deprecated_register_gdbarch_swap (NULL
, 0, build_parse
);
1321 add_setshow_zinteger_cmd ("expression", class_maintenance
,
1322 &expressiondebug
, _("\
1323 Set expression debugging."), _("\
1324 Show expression debugging."), _("\
1325 When non-zero, the internal representation of expressions will be printed."),
1327 show_expressiondebug
,
1328 &setdebuglist
, &showdebuglist
);