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 */
46 /* Global variables declared in parser-defs.h (and commented there). */
47 struct expression
*expout
;
50 struct block
*expression_context_block
;
51 struct block
*innermost_block
;
53 union type_stack_elt
*type_stack
;
54 int type_stack_depth
, type_stack_size
;
60 static int expressiondebug
= 0;
62 extern int hp_som_som_object_present
;
65 free_funcalls
PARAMS ((void));
68 prefixify_expression
PARAMS ((struct expression
*));
71 prefixify_subexp
PARAMS ((struct expression
*, struct expression
*, int, int));
73 void _initialize_parse
PARAMS ((void));
75 /* Data structure for saving values of arglist_len for function calls whose
76 arguments contain other function calls. */
84 static struct funcall
*funcall_chain
;
86 /* Assign machine-independent names to certain registers
87 (unless overridden by the REGISTER_NAMES table) */
90 unsigned num_std_regs
= 0;
91 struct std_regs std_regs
[1];
93 struct std_regs std_regs
[] = {
110 unsigned num_std_regs
= (sizeof std_regs
/ sizeof std_regs
[0]);
114 /* The generic method for targets to specify how their registers are
115 named. The mapping can be derived from three sources:
116 REGISTER_NAME; std_regs; or a target specific alias hook. */
119 target_map_name_to_register (str
, len
)
125 /* First try target specific aliases. We try these first because on some
126 systems standard names can be context dependent (eg. $pc on a
127 multiprocessor can be could be any of several PCs). */
128 #ifdef REGISTER_NAME_ALIAS_HOOK
129 i
= REGISTER_NAME_ALIAS_HOOK (str
, len
);
134 /* Search architectural register name space. */
135 for (i
= 0; i
< NUM_REGS
; i
++)
136 if (REGISTER_NAME (i
) && len
== strlen (REGISTER_NAME (i
))
137 && STREQN (str
, REGISTER_NAME (i
), len
))
142 /* Try standard aliases */
143 for (i
= 0; i
< num_std_regs
; i
++)
144 if (std_regs
[i
].name
&& len
== strlen (std_regs
[i
].name
)
145 && STREQN (str
, std_regs
[i
].name
, len
))
147 return std_regs
[i
].regnum
;
153 /* Begin counting arguments for a function call,
154 saving the data about any containing call. */
159 register struct funcall
*new;
161 new = (struct funcall
*) xmalloc (sizeof (struct funcall
));
162 new->next
= funcall_chain
;
163 new->arglist_len
= arglist_len
;
168 /* Return the number of arguments in a function call just terminated,
169 and restore the data for the containing function call. */
174 register int val
= arglist_len
;
175 register struct funcall
*call
= funcall_chain
;
176 funcall_chain
= call
->next
;
177 arglist_len
= call
->arglist_len
;
182 /* Free everything in the funcall chain.
183 Used when there is an error inside parsing. */
188 register struct funcall
*call
, *next
;
190 for (call
= funcall_chain
; call
; call
= next
)
197 /* This page contains the functions for adding data to the struct expression
198 being constructed. */
200 /* Add one element to the end of the expression. */
202 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
203 a register through here */
206 write_exp_elt (expelt
)
207 union exp_element expelt
;
209 if (expout_ptr
>= expout_size
)
212 expout
= (struct expression
*)
213 xrealloc ((char *) expout
, sizeof (struct expression
)
214 + EXP_ELEM_TO_BYTES (expout_size
));
216 expout
->elts
[expout_ptr
++] = expelt
;
220 write_exp_elt_opcode (expelt
)
221 enum exp_opcode expelt
;
223 union exp_element tmp
;
231 write_exp_elt_sym (expelt
)
232 struct symbol
*expelt
;
234 union exp_element tmp
;
242 write_exp_elt_block (b
)
245 union exp_element tmp
;
251 write_exp_elt_longcst (expelt
)
254 union exp_element tmp
;
256 tmp
.longconst
= expelt
;
262 write_exp_elt_dblcst (expelt
)
265 union exp_element tmp
;
267 tmp
.doubleconst
= expelt
;
273 write_exp_elt_type (expelt
)
276 union exp_element tmp
;
284 write_exp_elt_intern (expelt
)
285 struct internalvar
*expelt
;
287 union exp_element tmp
;
289 tmp
.internalvar
= expelt
;
294 /* Add a string constant to the end of the expression.
296 String constants are stored by first writing an expression element
297 that contains the length of the string, then stuffing the string
298 constant itself into however many expression elements are needed
299 to hold it, and then writing another expression element that contains
300 the length of the string. I.E. an expression element at each end of
301 the string records the string length, so you can skip over the
302 expression elements containing the actual string bytes from either
303 end of the string. Note that this also allows gdb to handle
304 strings with embedded null bytes, as is required for some languages.
306 Don't be fooled by the fact that the string is null byte terminated,
307 this is strictly for the convenience of debugging gdb itself. Gdb
308 Gdb does not depend up the string being null terminated, since the
309 actual length is recorded in expression elements at each end of the
310 string. The null byte is taken into consideration when computing how
311 many expression elements are required to hold the string constant, of
316 write_exp_string (str
)
319 register int len
= str
.length
;
321 register char *strdata
;
323 /* Compute the number of expression elements required to hold the string
324 (including a null byte terminator), along with one expression element
325 at each end to record the actual string length (not including the
326 null byte terminator). */
328 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
+ 1);
330 /* Ensure that we have enough available expression elements to store
333 if ((expout_ptr
+ lenelt
) >= expout_size
)
335 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
336 expout
= (struct expression
*)
337 xrealloc ((char *) expout
, (sizeof (struct expression
)
338 + EXP_ELEM_TO_BYTES (expout_size
)));
341 /* Write the leading length expression element (which advances the current
342 expression element index), then write the string constant followed by a
343 terminating null byte, and then write the trailing length expression
346 write_exp_elt_longcst ((LONGEST
) len
);
347 strdata
= (char *) &expout
->elts
[expout_ptr
];
348 memcpy (strdata
, str
.ptr
, len
);
349 *(strdata
+ len
) = '\0';
350 expout_ptr
+= lenelt
- 2;
351 write_exp_elt_longcst ((LONGEST
) len
);
354 /* Add a bitstring constant to the end of the expression.
356 Bitstring constants are stored by first writing an expression element
357 that contains the length of the bitstring (in bits), then stuffing the
358 bitstring constant itself into however many expression elements are
359 needed to hold it, and then writing another expression element that
360 contains the length of the bitstring. I.E. an expression element at
361 each end of the bitstring records the bitstring length, so you can skip
362 over the expression elements containing the actual bitstring bytes from
363 either end of the bitstring. */
366 write_exp_bitstring (str
)
369 register int bits
= str
.length
; /* length in bits */
370 register int len
= (bits
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
372 register char *strdata
;
374 /* Compute the number of expression elements required to hold the bitstring,
375 along with one expression element at each end to record the actual
376 bitstring length in bits. */
378 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
);
380 /* Ensure that we have enough available expression elements to store
383 if ((expout_ptr
+ lenelt
) >= expout_size
)
385 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
386 expout
= (struct expression
*)
387 xrealloc ((char *) expout
, (sizeof (struct expression
)
388 + EXP_ELEM_TO_BYTES (expout_size
)));
391 /* Write the leading length expression element (which advances the current
392 expression element index), then write the bitstring constant, and then
393 write the trailing length expression element. */
395 write_exp_elt_longcst ((LONGEST
) bits
);
396 strdata
= (char *) &expout
->elts
[expout_ptr
];
397 memcpy (strdata
, str
.ptr
, len
);
398 expout_ptr
+= lenelt
- 2;
399 write_exp_elt_longcst ((LONGEST
) bits
);
402 /* Add the appropriate elements for a minimal symbol to the end of
403 the expression. The rationale behind passing in text_symbol_type and
404 data_symbol_type was so that Modula-2 could pass in WORD for
405 data_symbol_type. Perhaps it still is useful to have those types vary
406 based on the language, but they no longer have names like "int", so
407 the initial rationale is gone. */
409 static struct type
*msym_text_symbol_type
;
410 static struct type
*msym_data_symbol_type
;
411 static struct type
*msym_unknown_symbol_type
;
414 write_exp_msymbol (msymbol
, text_symbol_type
, data_symbol_type
)
415 struct minimal_symbol
*msymbol
;
416 struct type
*text_symbol_type
;
417 struct type
*data_symbol_type
;
421 write_exp_elt_opcode (OP_LONG
);
422 write_exp_elt_type (lookup_pointer_type (builtin_type_void
));
424 addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
425 if (overlay_debugging
)
426 addr
= symbol_overlayed_address (addr
, SYMBOL_BFD_SECTION (msymbol
));
427 write_exp_elt_longcst ((LONGEST
) addr
);
429 write_exp_elt_opcode (OP_LONG
);
431 write_exp_elt_opcode (UNOP_MEMVAL
);
432 switch (msymbol
-> type
)
436 case mst_solib_trampoline
:
437 write_exp_elt_type (msym_text_symbol_type
);
444 write_exp_elt_type (msym_data_symbol_type
);
448 write_exp_elt_type (msym_unknown_symbol_type
);
451 write_exp_elt_opcode (UNOP_MEMVAL
);
454 /* Recognize tokens that start with '$'. These include:
456 $regname A native register name or a "standard
459 $variable A convenience variable with a name chosen
462 $digits Value history with index <digits>, starting
463 from the first value which has index 1.
465 $$digits Value history with index <digits> relative
466 to the last value. I.E. $$0 is the last
467 value, $$1 is the one previous to that, $$2
468 is the one previous to $$1, etc.
470 $ | $0 | $$0 The last value in the value history.
472 $$ An abbreviation for the second to the last
473 value in the value history, I.E. $$1
478 write_dollar_variable (str
)
481 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
482 and $$digits (equivalent to $<-digits> if you could type that). */
484 struct symbol
* sym
= NULL
;
485 struct minimal_symbol
* msym
= NULL
;
489 /* Double dollar means negate the number and add -1 as well.
490 Thus $$ alone means -1. */
491 if (str
.length
>= 2 && str
.ptr
[1] == '$')
498 /* Just dollars (one or two) */
502 /* Is the rest of the token digits? */
503 for (; i
< str
.length
; i
++)
504 if (!(str
.ptr
[i
] >= '0' && str
.ptr
[i
] <= '9'))
508 i
= atoi (str
.ptr
+ 1 + negate
);
514 /* Handle tokens that refer to machine registers:
515 $ followed by a register name. */
516 i
= target_map_name_to_register( str
.ptr
+ 1, str
.length
- 1 );
518 goto handle_register
;
520 /* On HP-UX, certain system routines (millicode) have names beginning
521 with $ or $$, e.g. $$dyncall, which handles inter-space procedure
522 calls on PA-RISC. Check for those, first. */
524 sym
= lookup_symbol (copy_name (str
), (struct block
*) NULL
,
525 VAR_NAMESPACE
, (int *) NULL
, (struct symtab
**) NULL
);
528 write_exp_elt_opcode (OP_VAR_VALUE
);
529 write_exp_elt_block (block_found
); /* set by lookup_symbol */
530 write_exp_elt_sym (sym
);
531 write_exp_elt_opcode (OP_VAR_VALUE
);
534 msym
= lookup_minimal_symbol (copy_name (str
), NULL
, NULL
);
537 write_exp_msymbol (msym
,
538 lookup_function_type (builtin_type_int
),
543 /* Any other names starting in $ are debugger internal variables. */
545 write_exp_elt_opcode (OP_INTERNALVAR
);
546 write_exp_elt_intern (lookup_internalvar (copy_name (str
) + 1));
547 write_exp_elt_opcode (OP_INTERNALVAR
);
550 write_exp_elt_opcode (OP_LAST
);
551 write_exp_elt_longcst ((LONGEST
) i
);
552 write_exp_elt_opcode (OP_LAST
);
555 write_exp_elt_opcode (OP_REGISTER
);
556 write_exp_elt_longcst (i
);
557 write_exp_elt_opcode (OP_REGISTER
);
562 /* Parse a string that is possibly a namespace / nested class
563 specification, i.e., something of the form A::B::C::x. Input
564 (NAME) is the entire string; LEN is the current valid length; the
565 output is a string, TOKEN, which points to the largest recognized
566 prefix which is a series of namespaces or classes. CLASS_PREFIX is
567 another output, which records whether a nested class spec was
568 recognized (= 1) or a fully qualified variable name was found (=
569 0). ARGPTR is side-effected (if non-NULL) to point to beyond the
570 string recognized and consumed by this routine.
572 The return value is a pointer to the symbol for the base class or
573 variable if found, or NULL if not found. Callers must check this
574 first -- if NULL, the outputs may not be correct.
576 This function is used c-exp.y. This is used specifically to get
577 around HP aCC (and possibly other compilers), which insists on
578 generating names with embedded colons for namespace or nested class
581 (Argument LEN is currently unused. 1997-08-27)
583 Callers must free memory allocated for the output string TOKEN. */
585 static const char coloncolon
[2] = {':',':'};
588 parse_nested_classes_for_hpacc (name
, len
, token
, class_prefix
, argptr
)
595 /* Comment below comes from decode_line_1 which has very similar
596 code, which is called for "break" command parsing. */
598 /* We have what looks like a class or namespace
599 scope specification (A::B), possibly with many
600 levels of namespaces or classes (A::B::C::D).
602 Some versions of the HP ANSI C++ compiler (as also possibly
603 other compilers) generate class/function/member names with
604 embedded double-colons if they are inside namespaces. To
605 handle this, we loop a few times, considering larger and
606 larger prefixes of the string as though they were single
607 symbols. So, if the initially supplied string is
608 A::B::C::D::foo, we have to look up "A", then "A::B",
609 then "A::B::C", then "A::B::C::D", and finally
610 "A::B::C::D::foo" as single, monolithic symbols, because
611 A, B, C or D may be namespaces.
613 Note that namespaces can nest only inside other
614 namespaces, and not inside classes. So we need only
615 consider *prefixes* of the string; there is no need to look up
616 "B::C" separately as a symbol in the previous example. */
620 char * prefix
= NULL
;
622 struct symbol
* sym_class
= NULL
;
623 struct symbol
* sym_var
= NULL
;
626 int colons_found
= 0;
631 /* Check for HP-compiled executable -- in other cases
632 return NULL, and caller must default to standard GDB
635 if (!hp_som_som_object_present
)
636 return (struct symbol
*) NULL
;
640 /* Skip over whitespace and possible global "::" */
641 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
642 if (p
[0] == ':' && p
[1] == ':')
644 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
648 /* Get to the end of the next namespace or class spec. */
649 /* If we're looking at some non-token, fail immediately */
651 if (!(isalpha (*p
) || *p
== '$' || *p
== '_'))
652 return (struct symbol
*) NULL
;
654 while (*p
&& (isalnum (*p
) || *p
== '$' || *p
== '_')) p
++;
658 /* If we have the start of a template specification,
659 scan right ahead to its end */
660 q
= find_template_name_end (p
);
667 /* Skip over "::" and whitespace for next time around */
668 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
669 if (p
[0] == ':' && p
[1] == ':')
671 while (*p
&& (*p
== ' ' || *p
== '\t')) p
++;
673 /* Done with tokens? */
674 if (!*p
|| !(isalpha (*p
) || *p
== '$' || *p
== '_'))
677 tmp
= (char *) alloca (prefix_len
+ end
- start
+ 3);
680 memcpy (tmp
, prefix
, prefix_len
);
681 memcpy (tmp
+ prefix_len
, coloncolon
, 2);
682 memcpy (tmp
+ prefix_len
+ 2, start
, end
- start
);
683 tmp
[prefix_len
+ 2 + end
- start
] = '\000';
687 memcpy (tmp
, start
, end
- start
);
688 tmp
[end
- start
] = '\000';
692 prefix_len
= strlen (prefix
);
694 #if 0 /* DEBUGGING */
695 printf ("Searching for nested class spec: Prefix is %s\n", prefix
);
698 /* See if the prefix we have now is something we know about */
702 /* More tokens to process, so this must be a class/namespace */
703 sym_class
= lookup_symbol (prefix
, 0, STRUCT_NAMESPACE
,
704 0, (struct symtab
**) NULL
);
708 /* No more tokens, so try as a variable first */
709 sym_var
= lookup_symbol (prefix
, 0, VAR_NAMESPACE
,
710 0, (struct symtab
**) NULL
);
711 /* If failed, try as class/namespace */
713 sym_class
= lookup_symbol (prefix
, 0, STRUCT_NAMESPACE
,
714 0, (struct symtab
**) NULL
);
719 (t
= check_typedef (SYMBOL_TYPE (sym_class
)),
720 (TYPE_CODE (t
) == TYPE_CODE_STRUCT
721 || TYPE_CODE (t
) == TYPE_CODE_UNION
))))
723 /* We found a valid token */
724 *token
= (char *) xmalloc (prefix_len
+ 1 );
725 memcpy (*token
, prefix
, prefix_len
);
726 (*token
)[prefix_len
] = '\000';
730 /* No variable or class/namespace found, no more tokens */
732 return (struct symbol
*) NULL
;
735 /* Out of loop, so we must have found a valid token */
742 *argptr
= done
? p
: end
;
744 #if 0 /* DEBUGGING */
745 printf ("Searching for nested class spec: Token is %s, class_prefix %d\n", *token
, *class_prefix
);
748 return sym_var
? sym_var
: sym_class
; /* found */
752 find_template_name_end (p
)
756 int just_seen_right
= 0;
757 int just_seen_colon
= 0;
758 int just_seen_space
= 0;
760 if (!p
|| (*p
!= '<'))
767 case '\'': case '\"':
769 /* In future, may want to allow these?? */
772 depth
++; /* start nested template */
773 if (just_seen_colon
|| just_seen_right
|| just_seen_space
)
774 return 0; /* but not after : or :: or > or space */
777 if (just_seen_colon
|| just_seen_right
)
778 return 0; /* end a (nested?) template */
779 just_seen_right
= 1; /* but not after : or :: */
780 if (--depth
== 0) /* also disallow >>, insist on > > */
781 return ++p
; /* if outermost ended, return */
784 if (just_seen_space
|| (just_seen_colon
> 1))
785 return 0; /* nested class spec coming up */
786 just_seen_colon
++; /* we allow :: but not :::: */
791 if (!((*p
>= 'a' && *p
<= 'z') || /* allow token chars */
792 (*p
>= 'A' && *p
<= 'Z') ||
793 (*p
>= '0' && *p
<= '9') ||
794 (*p
== '_') || (*p
== ',') || /* commas for template args */
795 (*p
== '&') || (*p
== '*') || /* pointer and ref types */
796 (*p
== '(') || (*p
== ')') || /* function types */
797 (*p
== '[') || (*p
== ']') )) /* array types */
812 /* Return a null-terminated temporary copy of the name
813 of a string token. */
819 memcpy (namecopy
, token
.ptr
, token
.length
);
820 namecopy
[token
.length
] = 0;
824 /* Reverse an expression from suffix form (in which it is constructed)
825 to prefix form (in which we can conveniently print or execute it). */
828 prefixify_expression (expr
)
829 register struct expression
*expr
;
832 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expr
->nelts
);
833 register struct expression
*temp
;
834 register int inpos
= expr
->nelts
, outpos
= 0;
836 temp
= (struct expression
*) alloca (len
);
838 /* Copy the original expression into temp. */
839 memcpy (temp
, expr
, len
);
841 prefixify_subexp (temp
, expr
, inpos
, outpos
);
844 /* Return the number of exp_elements in the subexpression of EXPR
845 whose last exp_element is at index ENDPOS - 1 in EXPR. */
848 length_of_subexp (expr
, endpos
)
849 register struct expression
*expr
;
852 register int oplen
= 1;
853 register int args
= 0;
857 error ("?error in length_of_subexp");
859 i
= (int) expr
->elts
[endpos
- 1].opcode
;
865 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
866 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
889 case OP_F77_UNDETERMINED_ARGLIST
:
891 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
919 case STRUCTOP_STRUCT
:
927 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
928 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
932 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
933 oplen
= (oplen
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
934 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
);
939 args
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
940 args
-= longest_to_int (expr
->elts
[endpos
- 3].longconst
);
946 case TERNOP_SLICE_COUNT
:
951 case MULTI_SUBSCRIPT
:
953 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
956 case BINOP_ASSIGN_MODIFY
:
967 args
= 1 + (i
< (int) BINOP_END
);
972 oplen
+= length_of_subexp (expr
, endpos
- oplen
);
979 /* Copy the subexpression ending just before index INEND in INEXPR
980 into OUTEXPR, starting at index OUTBEG.
981 In the process, convert it from suffix to prefix form. */
984 prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
)
985 register struct expression
*inexpr
;
986 struct expression
*outexpr
;
990 register int oplen
= 1;
991 register int args
= 0;
994 enum exp_opcode opcode
;
996 /* Compute how long the last operation is (in OPLEN),
997 and also how many preceding subexpressions serve as
998 arguments for it (in ARGS). */
1000 opcode
= inexpr
->elts
[inend
- 1].opcode
;
1005 oplen
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1006 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
1019 case OP_INTERNALVAR
:
1029 case OP_F77_UNDETERMINED_ARGLIST
:
1031 args
= 1 + longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1057 case STRUCTOP_STRUCT
:
1066 oplen
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1067 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
1071 oplen
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1072 oplen
= (oplen
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
1073 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
);
1078 args
= longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1079 args
-= longest_to_int (inexpr
->elts
[inend
- 3].longconst
);
1085 case TERNOP_SLICE_COUNT
:
1089 case BINOP_ASSIGN_MODIFY
:
1095 case MULTI_SUBSCRIPT
:
1097 args
= 1 + longest_to_int (inexpr
->elts
[inend
- 2].longconst
);
1106 args
= 1 + ((int) opcode
< (int) BINOP_END
);
1109 /* Copy the final operator itself, from the end of the input
1110 to the beginning of the output. */
1112 memcpy (&outexpr
->elts
[outbeg
], &inexpr
->elts
[inend
],
1113 EXP_ELEM_TO_BYTES (oplen
));
1116 /* Find the lengths of the arg subexpressions. */
1117 arglens
= (int *) alloca (args
* sizeof (int));
1118 for (i
= args
- 1; i
>= 0; i
--)
1120 oplen
= length_of_subexp (inexpr
, inend
);
1125 /* Now copy each subexpression, preserving the order of
1126 the subexpressions, but prefixifying each one.
1127 In this loop, inend starts at the beginning of
1128 the expression this level is working on
1129 and marches forward over the arguments.
1130 outbeg does similarly in the output. */
1131 for (i
= 0; i
< args
; i
++)
1135 prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
);
1140 /* This page contains the two entry points to this file. */
1142 /* Read an expression from the string *STRINGPTR points to,
1143 parse it, and return a pointer to a struct expression that we malloc.
1144 Use block BLOCK as the lexical context for variable names;
1145 if BLOCK is zero, use the block of the selected stack frame.
1146 Meanwhile, advance *STRINGPTR to point after the expression,
1147 at the first nonwhite character that is not part of the expression
1148 (possibly a null character).
1150 If COMMA is nonzero, stop if a comma is reached. */
1153 parse_exp_1 (stringptr
, block
, comma
)
1155 struct block
*block
;
1158 struct cleanup
*old_chain
;
1160 lexptr
= *stringptr
;
1163 type_stack_depth
= 0;
1165 comma_terminates
= comma
;
1167 if (lexptr
== 0 || *lexptr
== 0)
1168 error_no_arg ("expression to compute");
1170 old_chain
= make_cleanup ((make_cleanup_func
) free_funcalls
, 0);
1173 expression_context_block
= block
? block
: get_selected_block ();
1175 namecopy
= (char *) alloca (strlen (lexptr
) + 1);
1178 expout
= (struct expression
*)
1179 xmalloc (sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_size
));
1180 expout
->language_defn
= current_language
;
1181 make_cleanup ((make_cleanup_func
) free_current_contents
, &expout
);
1183 if (current_language
->la_parser ())
1184 current_language
->la_error (NULL
);
1186 discard_cleanups (old_chain
);
1188 /* Record the actual number of expression elements, and then
1189 reallocate the expression memory so that we free up any
1192 expout
->nelts
= expout_ptr
;
1193 expout
= (struct expression
*)
1194 xrealloc ((char *) expout
,
1195 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_ptr
));;
1197 /* Convert expression from postfix form as generated by yacc
1198 parser, to a prefix form. */
1200 if (expressiondebug
)
1201 dump_prefix_expression (expout
, gdb_stdout
,
1202 "before conversion to prefix form");
1204 prefixify_expression (expout
);
1206 if (expressiondebug
)
1207 dump_postfix_expression (expout
, gdb_stdout
,
1208 "after conversion to prefix form");
1210 *stringptr
= lexptr
;
1214 /* Parse STRING as an expression, and complain if this fails
1215 to use up all of the contents of STRING. */
1218 parse_expression (string
)
1221 register struct expression
*exp
;
1222 exp
= parse_exp_1 (&string
, 0, 0);
1224 error ("Junk after end of expression.");
1228 /* Stuff for maintaining a stack of types. Currently just used by C, but
1229 probably useful for any language which declares its types "backwards". */
1233 enum type_pieces tp
;
1235 if (type_stack_depth
== type_stack_size
)
1237 type_stack_size
*= 2;
1238 type_stack
= (union type_stack_elt
*)
1239 xrealloc ((char *) type_stack
, type_stack_size
* sizeof (*type_stack
));
1241 type_stack
[type_stack_depth
++].piece
= tp
;
1248 if (type_stack_depth
== type_stack_size
)
1250 type_stack_size
*= 2;
1251 type_stack
= (union type_stack_elt
*)
1252 xrealloc ((char *) type_stack
, type_stack_size
* sizeof (*type_stack
));
1254 type_stack
[type_stack_depth
++].int_val
= n
;
1260 if (type_stack_depth
)
1261 return type_stack
[--type_stack_depth
].piece
;
1268 if (type_stack_depth
)
1269 return type_stack
[--type_stack_depth
].int_val
;
1270 /* "Can't happen". */
1274 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1275 as modified by all the stuff on the stack. */
1277 follow_types (follow_type
)
1278 struct type
*follow_type
;
1282 struct type
*range_type
;
1285 switch (pop_type ())
1291 follow_type
= lookup_pointer_type (follow_type
);
1294 follow_type
= lookup_reference_type (follow_type
);
1297 array_size
= pop_type_int ();
1298 /* FIXME-type-allocation: need a way to free this type when we are
1301 create_range_type ((struct type
*) NULL
,
1302 builtin_type_int
, 0,
1303 array_size
>= 0 ? array_size
- 1 : 0);
1305 create_array_type ((struct type
*) NULL
,
1306 follow_type
, range_type
);
1308 TYPE_ARRAY_UPPER_BOUND_TYPE(follow_type
)
1309 = BOUND_CANNOT_BE_DETERMINED
;
1312 /* FIXME-type-allocation: need a way to free this type when we are
1314 follow_type
= lookup_function_type (follow_type
);
1321 _initialize_parse ()
1323 type_stack_size
= 80;
1324 type_stack_depth
= 0;
1325 type_stack
= (union type_stack_elt
*)
1326 xmalloc (type_stack_size
* sizeof (*type_stack
));
1328 msym_text_symbol_type
=
1329 init_type (TYPE_CODE_FUNC
, 1, 0, "<text variable, no debug info>", NULL
);
1330 TYPE_TARGET_TYPE (msym_text_symbol_type
) = builtin_type_int
;
1331 msym_data_symbol_type
=
1332 init_type (TYPE_CODE_INT
, TARGET_INT_BIT
/ HOST_CHAR_BIT
, 0,
1333 "<data variable, no debug info>", NULL
);
1334 msym_unknown_symbol_type
=
1335 init_type (TYPE_CODE_INT
, 1, 0,
1336 "<variable (not text or data), no debug info>",
1340 add_set_cmd ("expressiondebug", class_maintenance
, var_zinteger
,
1341 (char *)&expressiondebug
,
1342 "Set expression debugging.\n\
1343 When non-zero, the internal representation of expressions will be printed.",