1 /* Parse expressions for GDB.
2 Copyright 1986, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
4 Modified from expread.y by the Department of Computer Science at the
5 State University of New York at Buffalo, 1991.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
24 /* Parse an expression from text in a string,
25 and return the result as a struct expression pointer.
26 That structure contains arithmetic operations in reverse polish,
27 with constants represented by operations that are followed by special data.
28 See expression.h for the details of the format.
29 What is important here is that it can be built up sequentially
30 during the process of parsing; the lower levels of the tree always
31 come first in the result. */
36 #include "gdb_string.h"
40 #include "expression.h"
44 #include "parser-defs.h"
46 #include "symfile.h" /* for overlay functions */
47 #include "inferior.h" /* for NUM_PSEUDO_REGS. NOTE: replace
48 with "gdbarch.h" when appropriate. */
50 #include "gdb_assert.h"
53 /* Standard set of definitions for printing, dumping, prefixifying,
54 * and evaluating expressions. */
56 const struct exp_descriptor exp_descriptor_standard
=
58 print_subexp_standard
,
59 operator_length_standard
,
61 dump_subexp_body_standard
,
62 evaluate_subexp_standard
65 /* Symbols which architectures can redefine. */
67 /* Some systems have routines whose names start with `$'. Giving this
68 macro a non-zero value tells GDB's expression parser to check for
69 such routines when parsing tokens that begin with `$'.
71 On HP-UX, certain system routines (millicode) have names beginning
72 with `$' or `$$'. For example, `$$dyncall' is a millicode routine
73 that handles inter-space procedure calls on PA-RISC. */
74 #ifndef SYMBOLS_CAN_START_WITH_DOLLAR
75 #define SYMBOLS_CAN_START_WITH_DOLLAR (0)
80 /* Global variables declared in parser-defs.h (and commented there). */
81 struct expression
*expout
;
84 struct block
*expression_context_block
;
85 CORE_ADDR expression_context_pc
;
86 struct block
*innermost_block
;
88 union type_stack_elt
*type_stack
;
89 int type_stack_depth
, type_stack_size
;
96 static int expressiondebug
= 0;
98 static void free_funcalls (void *ignore
);
100 static void prefixify_expression (struct expression
*);
102 static void prefixify_subexp (struct expression
*, struct expression
*, int,
105 static struct expression
*parse_exp_in_context (char **, struct block
*, int,
108 void _initialize_parse (void);
110 /* Data structure for saving values of arglist_len for function calls whose
111 arguments contain other function calls. */
115 struct funcall
*next
;
119 static struct funcall
*funcall_chain
;
121 /* Begin counting arguments for a function call,
122 saving the data about any containing call. */
129 new = (struct funcall
*) xmalloc (sizeof (struct funcall
));
130 new->next
= funcall_chain
;
131 new->arglist_len
= arglist_len
;
136 /* Return the number of arguments in a function call just terminated,
137 and restore the data for the containing function call. */
142 int val
= arglist_len
;
143 struct funcall
*call
= funcall_chain
;
144 funcall_chain
= call
->next
;
145 arglist_len
= call
->arglist_len
;
150 /* Free everything in the funcall chain.
151 Used when there is an error inside parsing. */
154 free_funcalls (void *ignore
)
156 struct funcall
*call
, *next
;
158 for (call
= funcall_chain
; call
; call
= next
)
165 /* This page contains the functions for adding data to the struct expression
166 being constructed. */
168 /* Add one element to the end of the expression. */
170 /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into
171 a register through here */
174 write_exp_elt (union exp_element expelt
)
176 if (expout_ptr
>= expout_size
)
179 expout
= (struct expression
*)
180 xrealloc ((char *) expout
, sizeof (struct expression
)
181 + EXP_ELEM_TO_BYTES (expout_size
));
183 expout
->elts
[expout_ptr
++] = expelt
;
187 write_exp_elt_opcode (enum exp_opcode expelt
)
189 union exp_element tmp
;
197 write_exp_elt_sym (struct symbol
*expelt
)
199 union exp_element tmp
;
207 write_exp_elt_block (struct block
*b
)
209 union exp_element tmp
;
215 write_exp_elt_longcst (LONGEST expelt
)
217 union exp_element tmp
;
219 tmp
.longconst
= expelt
;
225 write_exp_elt_dblcst (DOUBLEST expelt
)
227 union exp_element tmp
;
229 tmp
.doubleconst
= expelt
;
235 write_exp_elt_type (struct type
*expelt
)
237 union exp_element tmp
;
245 write_exp_elt_intern (struct internalvar
*expelt
)
247 union exp_element tmp
;
249 tmp
.internalvar
= expelt
;
254 /* Add a string constant to the end of the expression.
256 String constants are stored by first writing an expression element
257 that contains the length of the string, then stuffing the string
258 constant itself into however many expression elements are needed
259 to hold it, and then writing another expression element that contains
260 the length of the string. I.E. an expression element at each end of
261 the string records the string length, so you can skip over the
262 expression elements containing the actual string bytes from either
263 end of the string. Note that this also allows gdb to handle
264 strings with embedded null bytes, as is required for some languages.
266 Don't be fooled by the fact that the string is null byte terminated,
267 this is strictly for the convenience of debugging gdb itself. Gdb
268 Gdb does not depend up the string being null terminated, since the
269 actual length is recorded in expression elements at each end of the
270 string. The null byte is taken into consideration when computing how
271 many expression elements are required to hold the string constant, of
276 write_exp_string (struct stoken str
)
278 int len
= str
.length
;
282 /* Compute the number of expression elements required to hold the string
283 (including a null byte terminator), along with one expression element
284 at each end to record the actual string length (not including the
285 null byte terminator). */
287 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
+ 1);
289 /* Ensure that we have enough available expression elements to store
292 if ((expout_ptr
+ lenelt
) >= expout_size
)
294 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
295 expout
= (struct expression
*)
296 xrealloc ((char *) expout
, (sizeof (struct expression
)
297 + EXP_ELEM_TO_BYTES (expout_size
)));
300 /* Write the leading length expression element (which advances the current
301 expression element index), then write the string constant followed by a
302 terminating null byte, and then write the trailing length expression
305 write_exp_elt_longcst ((LONGEST
) len
);
306 strdata
= (char *) &expout
->elts
[expout_ptr
];
307 memcpy (strdata
, str
.ptr
, len
);
308 *(strdata
+ len
) = '\0';
309 expout_ptr
+= lenelt
- 2;
310 write_exp_elt_longcst ((LONGEST
) len
);
313 /* Add a bitstring constant to the end of the expression.
315 Bitstring constants are stored by first writing an expression element
316 that contains the length of the bitstring (in bits), then stuffing the
317 bitstring constant itself into however many expression elements are
318 needed to hold it, and then writing another expression element that
319 contains the length of the bitstring. I.E. an expression element at
320 each end of the bitstring records the bitstring length, so you can skip
321 over the expression elements containing the actual bitstring bytes from
322 either end of the bitstring. */
325 write_exp_bitstring (struct stoken str
)
327 int bits
= str
.length
; /* length in bits */
328 int len
= (bits
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
332 /* Compute the number of expression elements required to hold the bitstring,
333 along with one expression element at each end to record the actual
334 bitstring length in bits. */
336 lenelt
= 2 + BYTES_TO_EXP_ELEM (len
);
338 /* Ensure that we have enough available expression elements to store
341 if ((expout_ptr
+ lenelt
) >= expout_size
)
343 expout_size
= max (expout_size
* 2, expout_ptr
+ lenelt
+ 10);
344 expout
= (struct expression
*)
345 xrealloc ((char *) expout
, (sizeof (struct expression
)
346 + EXP_ELEM_TO_BYTES (expout_size
)));
349 /* Write the leading length expression element (which advances the current
350 expression element index), then write the bitstring constant, and then
351 write the trailing length expression element. */
353 write_exp_elt_longcst ((LONGEST
) bits
);
354 strdata
= (char *) &expout
->elts
[expout_ptr
];
355 memcpy (strdata
, str
.ptr
, len
);
356 expout_ptr
+= lenelt
- 2;
357 write_exp_elt_longcst ((LONGEST
) bits
);
360 /* Add the appropriate elements for a minimal symbol to the end of
361 the expression. The rationale behind passing in text_symbol_type and
362 data_symbol_type was so that Modula-2 could pass in WORD for
363 data_symbol_type. Perhaps it still is useful to have those types vary
364 based on the language, but they no longer have names like "int", so
365 the initial rationale is gone. */
367 static struct type
*msym_text_symbol_type
;
368 static struct type
*msym_data_symbol_type
;
369 static struct type
*msym_unknown_symbol_type
;
372 write_exp_msymbol (struct minimal_symbol
*msymbol
,
373 struct type
*text_symbol_type
,
374 struct type
*data_symbol_type
)
378 write_exp_elt_opcode (OP_LONG
);
379 /* Let's make the type big enough to hold a 64-bit address. */
380 write_exp_elt_type (builtin_type_CORE_ADDR
);
382 addr
= SYMBOL_VALUE_ADDRESS (msymbol
);
383 if (overlay_debugging
)
384 addr
= symbol_overlayed_address (addr
, SYMBOL_BFD_SECTION (msymbol
));
385 write_exp_elt_longcst ((LONGEST
) addr
);
387 write_exp_elt_opcode (OP_LONG
);
389 write_exp_elt_opcode (UNOP_MEMVAL
);
390 switch (msymbol
->type
)
394 case mst_solib_trampoline
:
395 write_exp_elt_type (msym_text_symbol_type
);
402 write_exp_elt_type (msym_data_symbol_type
);
406 write_exp_elt_type (msym_unknown_symbol_type
);
409 write_exp_elt_opcode (UNOP_MEMVAL
);
412 /* Recognize tokens that start with '$'. These include:
414 $regname A native register name or a "standard
417 $variable A convenience variable with a name chosen
420 $digits Value history with index <digits>, starting
421 from the first value which has index 1.
423 $$digits Value history with index <digits> relative
424 to the last value. I.E. $$0 is the last
425 value, $$1 is the one previous to that, $$2
426 is the one previous to $$1, etc.
428 $ | $0 | $$0 The last value in the value history.
430 $$ An abbreviation for the second to the last
431 value in the value history, I.E. $$1
436 write_dollar_variable (struct stoken str
)
438 /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1)
439 and $$digits (equivalent to $<-digits> if you could type that). */
443 /* Double dollar means negate the number and add -1 as well.
444 Thus $$ alone means -1. */
445 if (str
.length
>= 2 && str
.ptr
[1] == '$')
452 /* Just dollars (one or two) */
456 /* Is the rest of the token digits? */
457 for (; i
< str
.length
; i
++)
458 if (!(str
.ptr
[i
] >= '0' && str
.ptr
[i
] <= '9'))
462 i
= atoi (str
.ptr
+ 1 + negate
);
468 /* Handle tokens that refer to machine registers:
469 $ followed by a register name. */
470 i
= frame_map_name_to_regnum (deprecated_selected_frame
,
471 str
.ptr
+ 1, str
.length
- 1);
473 goto handle_register
;
475 if (SYMBOLS_CAN_START_WITH_DOLLAR
)
477 struct symbol
*sym
= NULL
;
478 struct minimal_symbol
*msym
= NULL
;
480 /* On HP-UX, certain system routines (millicode) have names beginning
481 with $ or $$, e.g. $$dyncall, which handles inter-space procedure
482 calls on PA-RISC. Check for those, first. */
484 /* This code is not enabled on non HP-UX systems, since worst case
485 symbol table lookup performance is awful, to put it mildly. */
487 sym
= lookup_symbol (copy_name (str
), (struct block
*) NULL
,
488 VAR_DOMAIN
, (int *) NULL
, (struct symtab
**) NULL
);
491 write_exp_elt_opcode (OP_VAR_VALUE
);
492 write_exp_elt_block (block_found
); /* set by lookup_symbol */
493 write_exp_elt_sym (sym
);
494 write_exp_elt_opcode (OP_VAR_VALUE
);
497 msym
= lookup_minimal_symbol (copy_name (str
), NULL
, NULL
);
500 write_exp_msymbol (msym
,
501 lookup_function_type (builtin_type_int
),
507 /* Any other names starting in $ are debugger internal variables. */
509 write_exp_elt_opcode (OP_INTERNALVAR
);
510 write_exp_elt_intern (lookup_internalvar (copy_name (str
) + 1));
511 write_exp_elt_opcode (OP_INTERNALVAR
);
514 write_exp_elt_opcode (OP_LAST
);
515 write_exp_elt_longcst ((LONGEST
) i
);
516 write_exp_elt_opcode (OP_LAST
);
519 write_exp_elt_opcode (OP_REGISTER
);
520 write_exp_elt_longcst (i
);
521 write_exp_elt_opcode (OP_REGISTER
);
526 /* Parse a string that is possibly a namespace / nested class
527 specification, i.e., something of the form A::B::C::x. Input
528 (NAME) is the entire string; LEN is the current valid length; the
529 output is a string, TOKEN, which points to the largest recognized
530 prefix which is a series of namespaces or classes. CLASS_PREFIX is
531 another output, which records whether a nested class spec was
532 recognized (= 1) or a fully qualified variable name was found (=
533 0). ARGPTR is side-effected (if non-NULL) to point to beyond the
534 string recognized and consumed by this routine.
536 The return value is a pointer to the symbol for the base class or
537 variable if found, or NULL if not found. Callers must check this
538 first -- if NULL, the outputs may not be correct.
540 This function is used c-exp.y. This is used specifically to get
541 around HP aCC (and possibly other compilers), which insists on
542 generating names with embedded colons for namespace or nested class
545 (Argument LEN is currently unused. 1997-08-27)
547 Callers must free memory allocated for the output string TOKEN. */
549 static const char coloncolon
[2] =
553 parse_nested_classes_for_hpacc (char *name
, int len
, char **token
,
554 int *class_prefix
, char **argptr
)
556 /* Comment below comes from decode_line_1 which has very similar
557 code, which is called for "break" command parsing. */
559 /* We have what looks like a class or namespace
560 scope specification (A::B), possibly with many
561 levels of namespaces or classes (A::B::C::D).
563 Some versions of the HP ANSI C++ compiler (as also possibly
564 other compilers) generate class/function/member names with
565 embedded double-colons if they are inside namespaces. To
566 handle this, we loop a few times, considering larger and
567 larger prefixes of the string as though they were single
568 symbols. So, if the initially supplied string is
569 A::B::C::D::foo, we have to look up "A", then "A::B",
570 then "A::B::C", then "A::B::C::D", and finally
571 "A::B::C::D::foo" as single, monolithic symbols, because
572 A, B, C or D may be namespaces.
574 Note that namespaces can nest only inside other
575 namespaces, and not inside classes. So we need only
576 consider *prefixes* of the string; there is no need to look up
577 "B::C" separately as a symbol in the previous example. */
583 struct symbol
*sym_class
= NULL
;
584 struct symbol
*sym_var
= NULL
;
590 /* Check for HP-compiled executable -- in other cases
591 return NULL, and caller must default to standard GDB
594 if (!deprecated_hp_som_som_object_present
)
595 return (struct symbol
*) NULL
;
599 /* Skip over whitespace and possible global "::" */
600 while (*p
&& (*p
== ' ' || *p
== '\t'))
602 if (p
[0] == ':' && p
[1] == ':')
604 while (*p
&& (*p
== ' ' || *p
== '\t'))
609 /* Get to the end of the next namespace or class spec. */
610 /* If we're looking at some non-token, fail immediately */
612 if (!(isalpha (*p
) || *p
== '$' || *p
== '_'))
613 return (struct symbol
*) NULL
;
615 while (*p
&& (isalnum (*p
) || *p
== '$' || *p
== '_'))
620 /* If we have the start of a template specification,
621 scan right ahead to its end */
622 q
= find_template_name_end (p
);
629 /* Skip over "::" and whitespace for next time around */
630 while (*p
&& (*p
== ' ' || *p
== '\t'))
632 if (p
[0] == ':' && p
[1] == ':')
634 while (*p
&& (*p
== ' ' || *p
== '\t'))
637 /* Done with tokens? */
638 if (!*p
|| !(isalpha (*p
) || *p
== '$' || *p
== '_'))
641 tmp
= (char *) alloca (prefix_len
+ end
- start
+ 3);
644 memcpy (tmp
, prefix
, prefix_len
);
645 memcpy (tmp
+ prefix_len
, coloncolon
, 2);
646 memcpy (tmp
+ prefix_len
+ 2, start
, end
- start
);
647 tmp
[prefix_len
+ 2 + end
- start
] = '\000';
651 memcpy (tmp
, start
, end
- start
);
652 tmp
[end
- start
] = '\000';
656 prefix_len
= strlen (prefix
);
658 /* See if the prefix we have now is something we know about */
662 /* More tokens to process, so this must be a class/namespace */
663 sym_class
= lookup_symbol (prefix
, 0, STRUCT_DOMAIN
,
664 0, (struct symtab
**) NULL
);
668 /* No more tokens, so try as a variable first */
669 sym_var
= lookup_symbol (prefix
, 0, VAR_DOMAIN
,
670 0, (struct symtab
**) NULL
);
671 /* If failed, try as class/namespace */
673 sym_class
= lookup_symbol (prefix
, 0, STRUCT_DOMAIN
,
674 0, (struct symtab
**) NULL
);
679 (t
= check_typedef (SYMBOL_TYPE (sym_class
)),
680 (TYPE_CODE (t
) == TYPE_CODE_STRUCT
681 || TYPE_CODE (t
) == TYPE_CODE_UNION
))))
683 /* We found a valid token */
684 *token
= (char *) xmalloc (prefix_len
+ 1);
685 memcpy (*token
, prefix
, prefix_len
);
686 (*token
)[prefix_len
] = '\000';
690 /* No variable or class/namespace found, no more tokens */
692 return (struct symbol
*) NULL
;
695 /* Out of loop, so we must have found a valid token */
702 *argptr
= done
? p
: end
;
704 return sym_var
? sym_var
: sym_class
; /* found */
708 find_template_name_end (char *p
)
711 int just_seen_right
= 0;
712 int just_seen_colon
= 0;
713 int just_seen_space
= 0;
715 if (!p
|| (*p
!= '<'))
726 /* In future, may want to allow these?? */
729 depth
++; /* start nested template */
730 if (just_seen_colon
|| just_seen_right
|| just_seen_space
)
731 return 0; /* but not after : or :: or > or space */
734 if (just_seen_colon
|| just_seen_right
)
735 return 0; /* end a (nested?) template */
736 just_seen_right
= 1; /* but not after : or :: */
737 if (--depth
== 0) /* also disallow >>, insist on > > */
738 return ++p
; /* if outermost ended, return */
741 if (just_seen_space
|| (just_seen_colon
> 1))
742 return 0; /* nested class spec coming up */
743 just_seen_colon
++; /* we allow :: but not :::: */
748 if (!((*p
>= 'a' && *p
<= 'z') || /* allow token chars */
749 (*p
>= 'A' && *p
<= 'Z') ||
750 (*p
>= '0' && *p
<= '9') ||
751 (*p
== '_') || (*p
== ',') || /* commas for template args */
752 (*p
== '&') || (*p
== '*') || /* pointer and ref types */
753 (*p
== '(') || (*p
== ')') || /* function types */
754 (*p
== '[') || (*p
== ']'))) /* array types */
769 /* Return a null-terminated temporary copy of the name
770 of a string token. */
773 copy_name (struct stoken token
)
775 memcpy (namecopy
, token
.ptr
, token
.length
);
776 namecopy
[token
.length
] = 0;
780 /* Reverse an expression from suffix form (in which it is constructed)
781 to prefix form (in which we can conveniently print or execute it). */
784 prefixify_expression (struct expression
*expr
)
787 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expr
->nelts
);
788 struct expression
*temp
;
789 int inpos
= expr
->nelts
, outpos
= 0;
791 temp
= (struct expression
*) alloca (len
);
793 /* Copy the original expression into temp. */
794 memcpy (temp
, expr
, len
);
796 prefixify_subexp (temp
, expr
, inpos
, outpos
);
799 /* Return the number of exp_elements in the postfix subexpression
800 of EXPR whose operator is at index ENDPOS - 1 in EXPR. */
803 length_of_subexp (struct expression
*expr
, int endpos
)
807 operator_length (expr
, endpos
, &oplen
, &args
);
811 oplen
+= length_of_subexp (expr
, endpos
- oplen
);
818 /* Sets *OPLENP to the length of the operator whose (last) index is
819 ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that
823 operator_length (struct expression
*expr
, int endpos
, int *oplenp
, int *argsp
)
825 expr
->language_defn
->la_exp_desc
->operator_length (expr
, endpos
,
829 /* Default value for operator_length in exp_descriptor vectors. */
832 operator_length_standard (struct expression
*expr
, int endpos
,
833 int *oplenp
, int *argsp
)
840 error ("?error in operator_length_standard");
842 i
= (int) expr
->elts
[endpos
- 1].opcode
;
848 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
849 oplen
= 5 + BYTES_TO_EXP_ELEM (oplen
+ 1);
872 case OP_F77_UNDETERMINED_ARGLIST
:
874 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
877 case OP_OBJC_MSGCALL
: /* Objective C message (method) call */
879 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
907 case STRUCTOP_STRUCT
:
913 case OP_OBJC_NSSTRING
: /* Objective C Foundation Class NSString constant */
914 case OP_OBJC_SELECTOR
: /* Objective C "@selector" pseudo-op */
917 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
918 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
+ 1);
922 oplen
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
923 oplen
= (oplen
+ HOST_CHAR_BIT
- 1) / HOST_CHAR_BIT
;
924 oplen
= 4 + BYTES_TO_EXP_ELEM (oplen
);
929 args
= longest_to_int (expr
->elts
[endpos
- 2].longconst
);
930 args
-= longest_to_int (expr
->elts
[endpos
- 3].longconst
);
936 case TERNOP_SLICE_COUNT
:
941 case MULTI_SUBSCRIPT
:
943 args
= 1 + longest_to_int (expr
->elts
[endpos
- 2].longconst
);
946 case BINOP_ASSIGN_MODIFY
:
958 args
= 1 + (i
< (int) BINOP_END
);
965 /* Copy the subexpression ending just before index INEND in INEXPR
966 into OUTEXPR, starting at index OUTBEG.
967 In the process, convert it from suffix to prefix form. */
970 prefixify_subexp (struct expression
*inexpr
,
971 struct expression
*outexpr
, int inend
, int outbeg
)
977 enum exp_opcode opcode
;
979 operator_length (inexpr
, inend
, &oplen
, &args
);
981 /* Copy the final operator itself, from the end of the input
982 to the beginning of the output. */
984 memcpy (&outexpr
->elts
[outbeg
], &inexpr
->elts
[inend
],
985 EXP_ELEM_TO_BYTES (oplen
));
988 /* Find the lengths of the arg subexpressions. */
989 arglens
= (int *) alloca (args
* sizeof (int));
990 for (i
= args
- 1; i
>= 0; i
--)
992 oplen
= length_of_subexp (inexpr
, inend
);
997 /* Now copy each subexpression, preserving the order of
998 the subexpressions, but prefixifying each one.
999 In this loop, inend starts at the beginning of
1000 the expression this level is working on
1001 and marches forward over the arguments.
1002 outbeg does similarly in the output. */
1003 for (i
= 0; i
< args
; i
++)
1007 prefixify_subexp (inexpr
, outexpr
, inend
, outbeg
);
1012 /* This page contains the two entry points to this file. */
1014 /* Read an expression from the string *STRINGPTR points to,
1015 parse it, and return a pointer to a struct expression that we malloc.
1016 Use block BLOCK as the lexical context for variable names;
1017 if BLOCK is zero, use the block of the selected stack frame.
1018 Meanwhile, advance *STRINGPTR to point after the expression,
1019 at the first nonwhite character that is not part of the expression
1020 (possibly a null character).
1022 If COMMA is nonzero, stop if a comma is reached. */
1025 parse_exp_1 (char **stringptr
, struct block
*block
, int comma
)
1027 return parse_exp_in_context (stringptr
, block
, comma
, 0);
1030 /* As for parse_exp_1, except that if VOID_CONTEXT_P, then
1031 no value is expected from the expression. */
1033 static struct expression
*
1034 parse_exp_in_context (char **stringptr
, struct block
*block
, int comma
,
1037 struct cleanup
*old_chain
;
1039 lexptr
= *stringptr
;
1043 type_stack_depth
= 0;
1045 comma_terminates
= comma
;
1047 if (lexptr
== 0 || *lexptr
== 0)
1048 error_no_arg ("expression to compute");
1050 old_chain
= make_cleanup (free_funcalls
, 0 /*ignore*/);
1055 expression_context_block
= block
;
1056 expression_context_pc
= BLOCK_START (block
);
1059 expression_context_block
= get_selected_block (&expression_context_pc
);
1061 namecopy
= (char *) alloca (strlen (lexptr
) + 1);
1064 expout
= (struct expression
*)
1065 xmalloc (sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_size
));
1066 expout
->language_defn
= current_language
;
1067 make_cleanup (free_current_contents
, &expout
);
1069 if (current_language
->la_parser ())
1070 current_language
->la_error (NULL
);
1072 discard_cleanups (old_chain
);
1074 /* Record the actual number of expression elements, and then
1075 reallocate the expression memory so that we free up any
1078 expout
->nelts
= expout_ptr
;
1079 expout
= (struct expression
*)
1080 xrealloc ((char *) expout
,
1081 sizeof (struct expression
) + EXP_ELEM_TO_BYTES (expout_ptr
));;
1083 /* Convert expression from postfix form as generated by yacc
1084 parser, to a prefix form. */
1086 if (expressiondebug
)
1087 dump_raw_expression (expout
, gdb_stdlog
,
1088 "before conversion to prefix form");
1090 prefixify_expression (expout
);
1092 current_language
->la_post_parser (&expout
, void_context_p
);
1094 if (expressiondebug
)
1095 dump_prefix_expression (expout
, gdb_stdlog
);
1097 *stringptr
= lexptr
;
1101 /* Parse STRING as an expression, and complain if this fails
1102 to use up all of the contents of STRING. */
1105 parse_expression (char *string
)
1107 struct expression
*exp
;
1108 exp
= parse_exp_1 (&string
, 0, 0);
1110 error ("Junk after end of expression.");
1115 /* As for parse_expression, except that if VOID_CONTEXT_P, then
1116 no value is expected from the expression. */
1119 parse_expression_in_context (char *string
, int void_context_p
)
1121 struct expression
*exp
;
1122 exp
= parse_exp_in_context (&string
, 0, 0, void_context_p
);
1123 if (*string
!= '\000')
1124 error ("Junk after end of expression.");
1128 /* A post-parser that does nothing */
1132 null_post_parser (struct expression
**exp
, int void_context_p
)
1136 /* Stuff for maintaining a stack of types. Currently just used by C, but
1137 probably useful for any language which declares its types "backwards". */
1140 check_type_stack_depth (void)
1142 if (type_stack_depth
== type_stack_size
)
1144 type_stack_size
*= 2;
1145 type_stack
= (union type_stack_elt
*)
1146 xrealloc ((char *) type_stack
, type_stack_size
* sizeof (*type_stack
));
1151 push_type (enum type_pieces tp
)
1153 check_type_stack_depth ();
1154 type_stack
[type_stack_depth
++].piece
= tp
;
1158 push_type_int (int n
)
1160 check_type_stack_depth ();
1161 type_stack
[type_stack_depth
++].int_val
= n
;
1165 push_type_address_space (char *string
)
1167 push_type_int (address_space_name_to_int (string
));
1173 if (type_stack_depth
)
1174 return type_stack
[--type_stack_depth
].piece
;
1181 if (type_stack_depth
)
1182 return type_stack
[--type_stack_depth
].int_val
;
1183 /* "Can't happen". */
1187 /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE
1188 as modified by all the stuff on the stack. */
1190 follow_types (struct type
*follow_type
)
1194 int make_volatile
= 0;
1195 int make_addr_space
= 0;
1197 struct type
*range_type
;
1200 switch (pop_type ())
1205 follow_type
= make_cv_type (make_const
,
1206 TYPE_VOLATILE (follow_type
),
1209 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1212 if (make_addr_space
)
1213 follow_type
= make_type_with_address_space (follow_type
,
1215 make_const
= make_volatile
= 0;
1216 make_addr_space
= 0;
1224 case tp_space_identifier
:
1225 make_addr_space
= pop_type_int ();
1228 follow_type
= lookup_pointer_type (follow_type
);
1230 follow_type
= make_cv_type (make_const
,
1231 TYPE_VOLATILE (follow_type
),
1234 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1237 if (make_addr_space
)
1238 follow_type
= make_type_with_address_space (follow_type
,
1240 make_const
= make_volatile
= 0;
1241 make_addr_space
= 0;
1244 follow_type
= lookup_reference_type (follow_type
);
1246 follow_type
= make_cv_type (make_const
,
1247 TYPE_VOLATILE (follow_type
),
1250 follow_type
= make_cv_type (TYPE_CONST (follow_type
),
1253 if (make_addr_space
)
1254 follow_type
= make_type_with_address_space (follow_type
,
1256 make_const
= make_volatile
= 0;
1257 make_addr_space
= 0;
1260 array_size
= pop_type_int ();
1261 /* FIXME-type-allocation: need a way to free this type when we are
1264 create_range_type ((struct type
*) NULL
,
1265 builtin_type_int
, 0,
1266 array_size
>= 0 ? array_size
- 1 : 0);
1268 create_array_type ((struct type
*) NULL
,
1269 follow_type
, range_type
);
1271 TYPE_ARRAY_UPPER_BOUND_TYPE (follow_type
)
1272 = BOUND_CANNOT_BE_DETERMINED
;
1275 /* FIXME-type-allocation: need a way to free this type when we are
1277 follow_type
= lookup_function_type (follow_type
);
1283 static void build_parse (void);
1289 msym_text_symbol_type
=
1290 init_type (TYPE_CODE_FUNC
, 1, 0, "<text variable, no debug info>", NULL
);
1291 TYPE_TARGET_TYPE (msym_text_symbol_type
) = builtin_type_int
;
1292 msym_data_symbol_type
=
1293 init_type (TYPE_CODE_INT
, TARGET_INT_BIT
/ HOST_CHAR_BIT
, 0,
1294 "<data variable, no debug info>", NULL
);
1295 msym_unknown_symbol_type
=
1296 init_type (TYPE_CODE_INT
, 1, 0,
1297 "<variable (not text or data), no debug info>",
1301 /* This function avoids direct calls to fprintf
1302 in the parser generated debug code. */
1304 parser_fprintf (FILE *x
, const char *y
, ...)
1309 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1312 fprintf_unfiltered (gdb_stderr
, " Unknown FILE used.\n");
1313 vfprintf_unfiltered (gdb_stderr
, y
, args
);
1319 _initialize_parse (void)
1321 type_stack_size
= 80;
1322 type_stack_depth
= 0;
1323 type_stack
= (union type_stack_elt
*)
1324 xmalloc (type_stack_size
* sizeof (*type_stack
));
1328 /* FIXME - For the moment, handle types by swapping them in and out.
1329 Should be using the per-architecture data-pointer and a large
1331 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_text_symbol_type
);
1332 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_data_symbol_type
);
1333 DEPRECATED_REGISTER_GDBARCH_SWAP (msym_unknown_symbol_type
);
1334 deprecated_register_gdbarch_swap (NULL
, 0, build_parse
);
1337 add_set_cmd ("expression", class_maintenance
, var_zinteger
,
1338 (char *) &expressiondebug
,
1339 "Set expression debugging.\n\
1340 When non-zero, the internal representation of expressions will be printed.",