1 /* Parse expressions for GDB.
2 Copyright (C) 1986, 89, 90, 91, 94, 1998 Free Software Foundation, Inc.
3 Modified from expread.y by the Department of Computer Science at the
4 State University of New York at Buffalo, 1991.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
22 /* Parse an expression from text in a string,
23 and return the result as a struct expression pointer.
24 That structure contains arithmetic operations in reverse polish,
25 with constants represented by operations that are followed by special data.
26 See expression.h for the details of the format.
27 What is important here is that it can be built up sequentially
28 during the process of parsing; the lower levels of the tree always
29 come first in the result. */
32 #include "gdb_string.h"
37 #include "expression.h"
41 #include "parser-defs.h"
43 #include "symfile.h" /* for overlay functions */
45 /* Global variables declared in parser-defs.h (and commented there). */
46 struct expression
*expout
;
49 struct block
*expression_context_block
;
50 struct block
*innermost_block
;
52 union type_stack_elt
*type_stack
;
53 int type_stack_depth
, type_stack_size
;
59 #ifdef MAINTENANCE_CMDS
60 static int expressiondebug
= 0;
63 extern int hp_som_som_object_present
;
66 free_funcalls
PARAMS ((void));
69 prefixify_expression
PARAMS ((struct expression
*));
72 prefixify_subexp
PARAMS ((struct expression
*, struct expression
*, int, int));
74 /* Data structure for saving values of arglist_len for function calls whose
75 arguments contain other function calls. */
83 static struct funcall
*funcall_chain
;
85 /* Assign machine-independent names to certain registers
86 (unless overridden by the REGISTER_NAMES table) */
89 unsigned num_std_regs
= 0;
90 struct std_regs std_regs
[1];
92 struct std_regs std_regs
[] = {
109 unsigned num_std_regs
= (sizeof std_regs
/ sizeof std_regs
[0]);
113 /* The generic method for targets to specify how their registers are
114 named. The mapping can be derived from three sources:
115 REGISTER_NAME; std_regs; or a target specific alias hook. */
118 target_map_name_to_register (str
, len
)
124 /* First try target specific aliases. We try these first because on some
125 systems standard names can be context dependent (eg. $pc on a
126 multiprocessor can be could be any of several PCs). */
127 #ifdef REGISTER_NAME_ALIAS_HOOK
128 i
= REGISTER_NAME_ALIAS_HOOK (str
, len
);
133 /* Search architectural register name space. */
134 for (i
= 0; i
< NUM_REGS
; i
++)
135 if (REGISTER_NAME (i
) && len
== strlen (REGISTER_NAME (i
))
136 && STREQN (str
, REGISTER_NAME (i
), len
))
141 /* Try standard aliases */
142 for (i
= 0; i
< num_std_regs
; i
++)
143 if (std_regs
[i
].name
&& len
== strlen (std_regs
[i
].name
)
144 && STREQN (str
, std_regs
[i
].name
, len
))
146 return std_regs
[i
].regnum
;
152 /* Begin counting arguments for a function call,
153 saving the data about any containing call. */
158 register struct funcall
*new;
160 new = (struct funcall
*) xmalloc (sizeof (struct funcall
));
161 new->next
= funcall_chain
;
162 new->arglist_len
= arglist_len
;
167 /* Return the number of arguments in a function call just terminated,
168 and restore the data for the containing function call. */
173 register int val
= arglist_len
;
174 register struct funcall
*call
= funcall_chain
;
175 funcall_chain
= call
->next
;
176 arglist_len
= call
->arglist_len
;
181 /* Free everything in the funcall chain.
182 Used when there is an error inside parsing. */
187 register struct funcall
*call
, *next
;
189 for (call
= funcall_chain
; call
; call
= next
)
196 /* This page contains the functions for adding data to the struct expression
197 being constructed. */
199 /* Add one element to the end of the expression. */
201 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
202 a register through here */
205 write_exp_elt (expelt
)
206 union exp_element expelt
;
208 if (expout_ptr
>= expout_size
)
211 expout
= (struct expression
*)
212 xrealloc ((char *) expout
, sizeof (struct expression
)
213 + EXP_ELEM_TO_BYTES (expout_size
));
215 expout
->elts
[expout_ptr
++] = expelt
;
219 write_exp_elt_opcode (expelt
)
220 enum exp_opcode expelt
;
222 union exp_element tmp
;
230 write_exp_elt_sym (expelt
)
231 struct symbol
*expelt
;
233 union exp_element tmp
;
241 write_exp_elt_block (b
)
244 union exp_element tmp
;
250 write_exp_elt_longcst (expelt
)
253 union exp_element tmp
;
255 tmp
.longconst
= expelt
;
261 write_exp_elt_dblcst (expelt
)
264 union exp_element tmp
;
266 tmp
.doubleconst
= expelt
;
272 write_exp_elt_type (expelt
)
275 union exp_element tmp
;
283 write_exp_elt_intern (expelt
)
284 struct internalvar
*expelt
;
286 union exp_element tmp
;
288 tmp
.internalvar
= expelt
;
293 /* Add a string constant to the end of the expression.
295 String constants are stored by first writing an expression element
296 that contains the length of the string, then stuffing the string
297 constant itself into however many expression elements are needed
298 to hold it, and then writing another expression element that contains
299 the length of the string. I.E. an expression element at each end of
300 the string records the string length, so you can skip over the
301 expression elements containing the actual string bytes from either
302 end of the string. Note that this also allows gdb to handle
303 strings with embedded null bytes, as is required for some languages.
305 Don't be fooled by the fact that the string is null byte terminated,
306 this is strictly for the convenience of debugging gdb itself. Gdb
307 Gdb does not depend up the string being null terminated, since the
308 actual length is recorded in expression elements at each end of the
309 string. The null byte is taken into consideration when computing how
310 many expression elements are required to hold the string constant, of
315 write_exp_string (str
)
318 register int len
= str
.length
;
320 register char *strdata
;
322 /* Compute the number of expression elements required to hold the string
323 (including a null byte terminator), along with one expression element
324 at each end to record the actual string length (not including the
325 null byte terminator). */
327 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
+ 1);
329 /* Ensure that we have enough available expression elements to store
332 if ((expout_ptr
+ lenelt
) >= expout_size
)
334 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
335 expout
= (struct expression
*)
336 xrealloc ((char *) expout
, (sizeof (struct expression
)
337 + EXP_ELEM_TO_BYTES (expout_size
)));
340 /* Write the leading length expression element (which advances the current
341 expression element index), then write the string constant followed by a
342 terminating null byte, and then write the trailing length expression
345 write_exp_elt_longcst ((LONGEST
) len
);
346 strdata
= (char *) &expout
->elts
[expout_ptr
];
347 memcpy (strdata
, str
.ptr
, len
);
348 *(strdata
+ len
) = '\0';
349 expout_ptr
+= lenelt
- 2;
350 write_exp_elt_longcst ((LONGEST
) len
);
353 /* Add a bitstring constant to the end of the expression.
355 Bitstring constants are stored by first writing an expression element
356 that contains the length of the bitstring (in bits), then stuffing the
357 bitstring constant itself into however many expression elements are
358 needed to hold it, and then writing another expression element that
359 contains the length of the bitstring. I.E. an expression element at
360 each end of the bitstring records the bitstring length, so you can skip
361 over the expression elements containing the actual bitstring bytes from
362 either end of the bitstring. */
365 write_exp_bitstring (str
)
368 register int bits
= str
.length
; /* length in bits */
369 register int len
= (bits
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
371 register char *strdata
;
373 /* Compute the number of expression elements required to hold the bitstring,
374 along with one expression element at each end to record the actual
375 bitstring length in bits. */
377 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
);
379 /* Ensure that we have enough available expression elements to store
382 if ((expout_ptr
+ lenelt
) >= expout_size
)
384 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
385 expout
= (struct expression
*)
386 xrealloc ((char *) expout
, (sizeof (struct expression
)
387 + EXP_ELEM_TO_BYTES (expout_size
)));
390 /* Write the leading length expression element (which advances the current
391 expression element index), then write the bitstring constant, and then
392 write the trailing length expression element. */
394 write_exp_elt_longcst ((LONGEST
) bits
);
395 strdata
= (char *) &expout
->elts
[expout_ptr
];
396 memcpy (strdata
, str
.ptr
, len
);
397 expout_ptr
+= lenelt
- 2;
398 write_exp_elt_longcst ((LONGEST
) bits
);
401 /* Add the appropriate elements for a minimal symbol to the end of
402 the expression. The rationale behind passing in text_symbol_type and
403 data_symbol_type was so that Modula-2 could pass in WORD for
404 data_symbol_type. Perhaps it still is useful to have those types vary
405 based on the language, but they no longer have names like "int", so
406 the initial rationale is gone. */
408 static struct type
*msym_text_symbol_type
;
409 static struct type
*msym_data_symbol_type
;
410 static struct type
*msym_unknown_symbol_type
;
413 write_exp_msymbol (msymbol
, text_symbol_type
, data_symbol_type
)
414 struct minimal_symbol
*msymbol
;
415 struct type
*text_symbol_type
;
416 struct type
*data_symbol_type
;
420 write_exp_elt_opcode (OP_LONG
);
421 write_exp_elt_type (lookup_pointer_type (builtin_type_void
));
423 addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
424 if (overlay_debugging
)
425 addr
= symbol_overlayed_address (addr
, SYMBOL_BFD_SECTION (msymbol
));
426 write_exp_elt_longcst ((LONGEST
) addr
);
428 write_exp_elt_opcode (OP_LONG
);
430 write_exp_elt_opcode (UNOP_MEMVAL
);
431 switch (msymbol
-> type
)
435 case mst_solib_trampoline
:
436 write_exp_elt_type (msym_text_symbol_type
);
443 write_exp_elt_type (msym_data_symbol_type
);
447 write_exp_elt_type (msym_unknown_symbol_type
);
450 write_exp_elt_opcode (UNOP_MEMVAL
);
453 /* Recognize tokens that start with '$'. These include:
455 $regname A native register name or a "standard
458 $variable A convenience variable with a name chosen
461 $digits Value history with index <digits>, starting
462 from the first value which has index 1.
464 $$digits Value history with index <digits> relative
465 to the last value. I.E. $$0 is the last
466 value, $$1 is the one previous to that, $$2
467 is the one previous to $$1, etc.
469 $ | $0 | $$0 The last value in the value history.
471 $$ An abbreviation for the second to the last
472 value in the value history, I.E. $$1
477 write_dollar_variable (str
)
480 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
481 and $$digits (equivalent to $<-digits> if you could type that). */
483 struct symbol
* sym
= NULL
;
484 struct minimal_symbol
* msym
= NULL
;
488 /* Double dollar means negate the number and add -1 as well.
489 Thus $$ alone means -1. */
490 if (str
.length
>= 2 && str
.ptr
[1] == '$')
497 /* Just dollars (one or two) */
501 /* Is the rest of the token digits? */
502 for (; i
< str
.length
; i
++)
503 if (!(str
.ptr
[i
] >= '0' && str
.ptr
[i
] <= '9'))
507 i
= atoi (str
.ptr
+ 1 + negate
);
513 /* Handle tokens that refer to machine registers:
514 $ followed by a register name. */
515 i
= target_map_name_to_register( str
.ptr
+ 1, str
.length
- 1 );
517 goto handle_register
;
519 /* On HP-UX, certain system routines (millicode) have names beginning
520 with $ or $$, e.g. $$dyncall, which handles inter-space procedure
521 calls on PA-RISC. Check for those, first. */
523 sym
= lookup_symbol (copy_name (str
), (struct block
*) NULL
,
524 VAR_NAMESPACE
, (int *) NULL
, (struct symtab
**) NULL
);
527 write_exp_elt_opcode (OP_VAR_VALUE
);
528 write_exp_elt_block (block_found
); /* set by lookup_symbol */
529 write_exp_elt_sym (sym
);
530 write_exp_elt_opcode (OP_VAR_VALUE
);
533 msym
= lookup_minimal_symbol (copy_name (str
), NULL
, NULL
);
536 write_exp_msymbol (msym
,
537 lookup_function_type (builtin_type_int
),
542 /* Any other names starting in $ are debugger internal variables. */
544 write_exp_elt_opcode (OP_INTERNALVAR
);
545 write_exp_elt_intern (lookup_internalvar (copy_name (str
) + 1));
546 write_exp_elt_opcode (OP_INTERNALVAR
);
549 write_exp_elt_opcode (OP_LAST
);
550 write_exp_elt_longcst ((LONGEST
) i
);
551 write_exp_elt_opcode (OP_LAST
);
554 write_exp_elt_opcode (OP_REGISTER
);
555 write_exp_elt_longcst (i
);
556 write_exp_elt_opcode (OP_REGISTER
);
561 /* Parse a string that is possibly a namespace / nested class
562 specification, i.e., something of the form A::B::C::x. Input
563 (NAME) is the entire string; LEN is the current valid length; the
564 output is a string, TOKEN, which points to the largest recognized
565 prefix which is a series of namespaces or classes. CLASS_PREFIX is
566 another output, which records whether a nested class spec was
567 recognized (= 1) or a fully qualified variable name was found (=
568 0). ARGPTR is side-effected (if non-NULL) to point to beyond the
569 string recognized and consumed by this routine.
571 The return value is a pointer to the symbol for the base class or
572 variable if found, or NULL if not found. Callers must check this
573 first -- if NULL, the outputs may not be correct.
575 This function is used c-exp.y. This is used specifically to get
576 around HP aCC (and possibly other compilers), which insists on
577 generating names with embedded colons for namespace or nested class
580 (Argument LEN is currently unused. 1997-08-27)
582 Callers must free memory allocated for the output string TOKEN. */
584 static const char coloncolon
[2] = {':',':'};
587 parse_nested_classes_for_hpacc (name
, len
, token
, class_prefix
, argptr
)
594 /* Comment below comes from decode_line_1 which has very similar
595 code, which is called for "break" command parsing. */
597 /* We have what looks like a class or namespace
598 scope specification (A::B), possibly with many
599 levels of namespaces or classes (A::B::C::D).
601 Some versions of the HP ANSI C++ compiler (as also possibly
602 other compilers) generate class/function/member names with
603 embedded double-colons if they are inside namespaces. To
604 handle this, we loop a few times, considering larger and
605 larger prefixes of the string as though they were single
606 symbols. So, if the initially supplied string is
607 A::B::C::D::foo, we have to look up "A", then "A::B",
608 then "A::B::C", then "A::B::C::D", and finally
609 "A::B::C::D::foo" as single, monolithic symbols, because
610 A, B, C or D may be namespaces.
612 Note that namespaces can nest only inside other
613 namespaces, and not inside classes. So we need only
614 consider *prefixes* of the string; there is no need to look up
615 "B::C" separately as a symbol in the previous example. */
619 char * prefix
= NULL
;
621 struct symbol
* sym_class
= NULL
;
622 struct symbol
* sym_var
= NULL
;
625 int colons_found
= 0;
630 /* Check for HP-compiled executable -- in other cases
631 return NULL, and caller must default to standard GDB
634 if (!hp_som_som_object_present
)
635 return (struct symbol
*) NULL
;
639 /* Skip over whitespace and possible global "::" */
640 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
641 if (p
[0] == ':' && p
[1] == ':')
643 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
647 /* Get to the end of the next namespace or class spec. */
648 /* If we're looking at some non-token, fail immediately */
650 if (!(isalpha (*p
) || *p
== '$' || *p
== '_'))
651 return (struct symbol
*) NULL
;
653 while (*p
&& (isalnum (*p
) || *p
== '$' || *p
== '_')) p
++;
657 /* If we have the start of a template specification,
658 scan right ahead to its end */
659 q
= find_template_name_end (p
);
666 /* Skip over "::" and whitespace for next time around */
667 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
668 if (p
[0] == ':' && p
[1] == ':')
670 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
672 /* Done with tokens? */
673 if (!*p
|| !(isalpha (*p
) || *p
== '$' || *p
== '_'))
676 tmp
= (char *) alloca (prefix_len
+ end
- start
+ 3);
679 memcpy (tmp
, prefix
, prefix_len
);
680 memcpy (tmp
+ prefix_len
, coloncolon
, 2);
681 memcpy (tmp
+ prefix_len
+ 2, start
, end
- start
);
682 tmp
[prefix_len
+ 2 + end
- start
] = '\000';
686 memcpy (tmp
, start
, end
- start
);
687 tmp
[end
- start
] = '\000';
691 prefix_len
= strlen (prefix
);
693 #if 0 /* DEBUGGING */
694 printf ("Searching for nested class spec: Prefix is %s\n", prefix
);
697 /* See if the prefix we have now is something we know about */
701 /* More tokens to process, so this must be a class/namespace */
702 sym_class
= lookup_symbol (prefix
, 0, STRUCT_NAMESPACE
,
703 0, (struct symtab
**) NULL
);
707 /* No more tokens, so try as a variable first */
708 sym_var
= lookup_symbol (prefix
, 0, VAR_NAMESPACE
,
709 0, (struct symtab
**) NULL
);
710 /* If failed, try as class/namespace */
712 sym_class
= lookup_symbol (prefix
, 0, STRUCT_NAMESPACE
,
713 0, (struct symtab
**) NULL
);
718 (t
= check_typedef (SYMBOL_TYPE (sym_class
)),
719 (TYPE_CODE (t
) == TYPE_CODE_STRUCT
720 || TYPE_CODE (t
) == TYPE_CODE_UNION
))))
722 /* We found a valid token */
723 *token
= (char *) xmalloc (prefix_len
+ 1 );
724 memcpy (*token
, prefix
, prefix_len
);
725 (*token
)[prefix_len
] = '\000';
729 /* No variable or class/namespace found, no more tokens */
731 return (struct symbol
*) NULL
;
734 /* Out of loop, so we must have found a valid token */
741 *argptr
= done
? p
: end
;
743 #if 0 /* DEBUGGING */
744 printf ("Searching for nested class spec: Token is %s, class_prefix %d\n", *token
, *class_prefix
);
747 return sym_var
? sym_var
: sym_class
; /* found */
751 find_template_name_end (p
)
755 int just_seen_right
= 0;
756 int just_seen_colon
= 0;
757 int just_seen_space
= 0;
759 if (!p
|| (*p
!= '<'))
766 case '\'': case '\"':
768 /* In future, may want to allow these?? */
771 depth
++; /* start nested template */
772 if (just_seen_colon
|| just_seen_right
|| just_seen_space
)
773 return 0; /* but not after : or :: or > or space */
776 if (just_seen_colon
|| just_seen_right
)
777 return 0; /* end a (nested?) template */
778 just_seen_right
= 1; /* but not after : or :: */
779 if (--depth
== 0) /* also disallow >>, insist on > > */
780 return ++p
; /* if outermost ended, return */
783 if (just_seen_space
|| (just_seen_colon
> 1))
784 return 0; /* nested class spec coming up */
785 just_seen_colon
++; /* we allow :: but not :::: */
790 if (!((*p
>= 'a' && *p
<= 'z') || /* allow token chars */
791 (*p
>= 'A' && *p
<= 'Z') ||
792 (*p
>= '0' && *p
<= '9') ||
793 (*p
== '_') || (*p
== ',') || /* commas for template args */
794 (*p
== '&') || (*p
== '*') || /* pointer and ref types */
795 (*p
== '(') || (*p
== ')') || /* function types */
796 (*p
== '[') || (*p
== ']') )) /* array types */
811 /* Return a null-terminated temporary copy of the name
812 of a string token. */
818 memcpy (namecopy
, token
.ptr
, token
.length
);
819 namecopy
[token
.length
] = 0;
823 /* Reverse an expression from suffix form (in which it is constructed)
824 to prefix form (in which we can conveniently print or execute it). */
827 prefixify_expression (expr
)
828 register struct expression
*expr
;
831 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expr
->nelts
);
832 register struct expression
*temp
;
833 register int inpos
= expr
->nelts
, outpos
= 0;
835 temp
= (struct expression
*) alloca (len
);
837 /* Copy the original expression into temp. */
838 memcpy (temp
, expr
, len
);
840 prefixify_subexp (temp
, expr
, inpos
, outpos
);
843 /* Return the number of exp_elements in the subexpression of EXPR
844 whose last exp_element is at index ENDPOS - 1 in EXPR. */
847 length_of_subexp (expr
, endpos
)
848 register struct expression
*expr
;
851 register int oplen
= 1;
852 register int args
= 0;
856 error ("?error in length_of_subexp");
858 i
= (int) expr
->elts
[endpos
- 1].opcode
;
864 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
865 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
888 case OP_F77_UNDETERMINED_ARGLIST
:
890 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
918 case STRUCTOP_STRUCT
:
926 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
927 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
931 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
932 oplen
= (oplen
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
933 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
);
938 args
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
939 args
-= longest_to_int (expr
->elts
[endpos
- 3].longconst
);
945 case TERNOP_SLICE_COUNT
:
950 case MULTI_SUBSCRIPT
:
952 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
955 case BINOP_ASSIGN_MODIFY
:
966 args
= 1 + (i
< (int) BINOP_END
);
971 oplen
+= length_of_subexp (expr
, endpos
- oplen
);
978 /* Copy the subexpression ending just before index INEND in INEXPR
979 into OUTEXPR, starting at index OUTBEG.
980 In the process, convert it from suffix to prefix form. */
983 prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
)
984 register struct expression
*inexpr
;
985 struct expression
*outexpr
;
989 register int oplen
= 1;
990 register int args
= 0;
993 enum exp_opcode opcode
;
995 /* Compute how long the last operation is (in OPLEN),
996 and also how many preceding subexpressions serve as
997 arguments for it (in ARGS). */
999 opcode
= inexpr
->elts
[inend
- 1].opcode
;
1004 oplen
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1005 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
1018 case OP_INTERNALVAR
:
1028 case OP_F77_UNDETERMINED_ARGLIST
:
1030 args
= 1 + longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1056 case STRUCTOP_STRUCT
:
1065 oplen
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1066 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
1070 oplen
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1071 oplen
= (oplen
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
1072 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
);
1077 args
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1078 args
-= longest_to_int (inexpr
->elts
[inend
- 3].longconst
);
1084 case TERNOP_SLICE_COUNT
:
1088 case BINOP_ASSIGN_MODIFY
:
1094 case MULTI_SUBSCRIPT
:
1096 args
= 1 + longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1105 args
= 1 + ((int) opcode
< (int) BINOP_END
);
1108 /* Copy the final operator itself, from the end of the input
1109 to the beginning of the output. */
1111 memcpy (&outexpr
->elts
[outbeg
], &inexpr
->elts
[inend
],
1112 EXP_ELEM_TO_BYTES (oplen
));
1115 /* Find the lengths of the arg subexpressions. */
1116 arglens
= (int *) alloca (args
* sizeof (int));
1117 for (i
= args
- 1; i
>= 0; i
--)
1119 oplen
= length_of_subexp (inexpr
, inend
);
1124 /* Now copy each subexpression, preserving the order of
1125 the subexpressions, but prefixifying each one.
1126 In this loop, inend starts at the beginning of
1127 the expression this level is working on
1128 and marches forward over the arguments.
1129 outbeg does similarly in the output. */
1130 for (i
= 0; i
< args
; i
++)
1134 prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
);
1139 /* This page contains the two entry points to this file. */
1141 /* Read an expression from the string *STRINGPTR points to,
1142 parse it, and return a pointer to a struct expression that we malloc.
1143 Use block BLOCK as the lexical context for variable names;
1144 if BLOCK is zero, use the block of the selected stack frame.
1145 Meanwhile, advance *STRINGPTR to point after the expression,
1146 at the first nonwhite character that is not part of the expression
1147 (possibly a null character).
1149 If COMMA is nonzero, stop if a comma is reached. */
1152 parse_exp_1 (stringptr
, block
, comma
)
1154 struct block
*block
;
1157 struct cleanup
*old_chain
;
1159 lexptr
= *stringptr
;
1162 type_stack_depth
= 0;
1164 comma_terminates
= comma
;
1166 if (lexptr
== 0 || *lexptr
== 0)
1167 error_no_arg ("expression to compute");
1169 old_chain
= make_cleanup ((make_cleanup_func
) free_funcalls
, 0);
1172 expression_context_block
= block
? block
: get_selected_block ();
1174 namecopy
= (char *) alloca (strlen (lexptr
) + 1);
1177 expout
= (struct expression
*)
1178 xmalloc (sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_size
));
1179 expout
->language_defn
= current_language
;
1180 make_cleanup ((make_cleanup_func
) free_current_contents
, &expout
);
1182 if (current_language
->la_parser ())
1183 current_language
->la_error (NULL
);
1185 discard_cleanups (old_chain
);
1187 /* Record the actual number of expression elements, and then
1188 reallocate the expression memory so that we free up any
1191 expout
->nelts
= expout_ptr
;
1192 expout
= (struct expression
*)
1193 xrealloc ((char *) expout
,
1194 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_ptr
));;
1196 /* Convert expression from postfix form as generated by yacc
1197 parser, to a prefix form. */
1199 #ifdef MAINTENANCE_CMDS
1200 if (expressiondebug
)
1201 dump_prefix_expression (expout
, gdb_stdout
,
1202 "before conversion to prefix form");
1203 #endif /* MAINTENANCE_CMDS */
1205 prefixify_expression (expout
);
1207 #ifdef MAINTENANCE_CMDS
1208 if (expressiondebug
)
1209 dump_postfix_expression (expout
, gdb_stdout
,
1210 "after conversion to prefix form");
1211 #endif /* MAINTENANCE_CMDS */
1213 *stringptr
= lexptr
;
1217 /* Parse STRING as an expression, and complain if this fails
1218 to use up all of the contents of STRING. */
1221 parse_expression (string
)
1224 register struct expression
*exp
;
1225 exp
= parse_exp_1 (&string
, 0, 0);
1227 error ("Junk after end of expression.");
1231 /* Stuff for maintaining a stack of types. Currently just used by C, but
1232 probably useful for any language which declares its types "backwards". */
1236 enum type_pieces tp
;
1238 if (type_stack_depth
== type_stack_size
)
1240 type_stack_size
*= 2;
1241 type_stack
= (union type_stack_elt
*)
1242 xrealloc ((char *) type_stack
, type_stack_size
* sizeof (*type_stack
));
1244 type_stack
[type_stack_depth
++].piece
= tp
;
1251 if (type_stack_depth
== type_stack_size
)
1253 type_stack_size
*= 2;
1254 type_stack
= (union type_stack_elt
*)
1255 xrealloc ((char *) type_stack
, type_stack_size
* sizeof (*type_stack
));
1257 type_stack
[type_stack_depth
++].int_val
= n
;
1263 if (type_stack_depth
)
1264 return type_stack
[--type_stack_depth
].piece
;
1271 if (type_stack_depth
)
1272 return type_stack
[--type_stack_depth
].int_val
;
1273 /* "Can't happen". */
1277 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1278 as modified by all the stuff on the stack. */
1280 follow_types (follow_type
)
1281 struct type
*follow_type
;
1285 struct type
*range_type
;
1288 switch (pop_type ())
1294 follow_type
= lookup_pointer_type (follow_type
);
1297 follow_type
= lookup_reference_type (follow_type
);
1300 array_size
= pop_type_int ();
1301 /* FIXME-type-allocation: need a way to free this type when we are
1304 create_range_type ((struct type
*) NULL
,
1305 builtin_type_int
, 0,
1306 array_size
>= 0 ? array_size
- 1 : 0);
1308 create_array_type ((struct type
*) NULL
,
1309 follow_type
, range_type
);
1311 TYPE_ARRAY_UPPER_BOUND_TYPE(follow_type
)
1312 = BOUND_CANNOT_BE_DETERMINED
;
1315 /* FIXME-type-allocation: need a way to free this type when we are
1317 follow_type
= lookup_function_type (follow_type
);
1324 _initialize_parse ()
1326 type_stack_size
= 80;
1327 type_stack_depth
= 0;
1328 type_stack
= (union type_stack_elt
*)
1329 xmalloc (type_stack_size
* sizeof (*type_stack
));
1331 msym_text_symbol_type
=
1332 init_type (TYPE_CODE_FUNC
, 1, 0, "<text variable, no debug info>", NULL
);
1333 TYPE_TARGET_TYPE (msym_text_symbol_type
) = builtin_type_int
;
1334 msym_data_symbol_type
=
1335 init_type (TYPE_CODE_INT
, TARGET_INT_BIT
/ HOST_CHAR_BIT
, 0,
1336 "<data variable, no debug info>", NULL
);
1337 msym_unknown_symbol_type
=
1338 init_type (TYPE_CODE_INT
, 1, 0,
1339 "<variable (not text or data), no debug info>",
1342 #ifdef MAINTENANCE_CMDS
1344 add_set_cmd ("expressiondebug", class_maintenance
, var_zinteger
,
1345 (char *)&expressiondebug
,
1346 "Set expression debugging.\n\
1347 When non-zero, the internal representation of expressions will be printed.",