1 /* Perform non-arithmetic operations on values, for GDB.
2 Copyright 1986, 1987, 1989, 1991, 1992 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
33 /* Local functions. */
36 typecmp PARAMS ((int staticp, struct type *t1[], value t2[]));
39 find_function_addr PARAMS ((value, struct type **));
42 value_push PARAMS ((CORE_ADDR, value));
45 value_arg_push PARAMS ((CORE_ADDR, value));
48 search_struct_field PARAMS ((char *, value, int, struct type *, int));
51 search_struct_method PARAMS ((char *, value *, value *, int, int *,
55 check_field_in PARAMS ((struct type *, const char *));
58 allocate_space_in_inferior PARAMS ((int));
61 /* Allocate NBYTES of space in the inferior using the inferior's malloc
62 and return a value that is a pointer to the allocated space. */
65 allocate_space_in_inferior (len)
69 register struct symbol *sym;
70 struct minimal_symbol *msymbol;
75 /* Find the address of malloc in the inferior. */
77 sym = lookup_symbol ("malloc", 0, VAR_NAMESPACE, 0, NULL);
80 if (SYMBOL_CLASS (sym) != LOC_BLOCK)
82 error ("\"malloc\" exists in this program but is not a function.");
84 val = value_of_variable (sym);
88 msymbol = lookup_minimal_symbol ("malloc", (struct objfile *) NULL);
91 type = lookup_pointer_type (builtin_type_char);
92 type = lookup_function_type (type);
93 type = lookup_pointer_type (type);
94 maddr = (LONGEST) SYMBOL_VALUE_ADDRESS (msymbol);
95 val = value_from_longest (type, maddr);
99 error ("evaluation of this expression requires the program to have a function \"malloc\".");
103 blocklen = value_from_longest (builtin_type_int, (LONGEST) len);
104 val = call_function_by_hand (val, 1, &blocklen);
105 if (value_logical_not (val))
107 error ("No memory available to program.");
109 return (value_as_long (val));
112 /* Cast value ARG2 to type TYPE and return as a value.
113 More general than a C cast: accepts any two types of the same length,
114 and if ARG2 is an lvalue it can be cast into anything at all. */
115 /* In C++, casts may change pointer or object representations. */
118 value_cast (type, arg2)
122 register enum type_code code1;
123 register enum type_code code2;
126 /* Coerce arrays but not enums. Enums will work as-is
127 and coercing them would cause an infinite recursion. */
128 if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_ENUM)
131 code1 = TYPE_CODE (type);
132 code2 = TYPE_CODE (VALUE_TYPE (arg2));
133 scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
134 || code2 == TYPE_CODE_ENUM);
136 if ( code1 == TYPE_CODE_STRUCT
137 && code2 == TYPE_CODE_STRUCT
138 && TYPE_NAME (type) != 0)
140 /* Look in the type of the source to see if it contains the
141 type of the target as a superclass. If so, we'll need to
142 offset the object in addition to changing its type. */
143 value v = search_struct_field (type_name_no_tag (type),
144 arg2, 0, VALUE_TYPE (arg2), 1);
147 VALUE_TYPE (v) = type;
151 if (code1 == TYPE_CODE_FLT && scalar)
152 return value_from_double (type, value_as_double (arg2));
153 else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM)
154 && (scalar || code2 == TYPE_CODE_PTR))
155 return value_from_longest (type, value_as_long (arg2));
156 else if (TYPE_LENGTH (type) == TYPE_LENGTH (VALUE_TYPE (arg2)))
158 if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR)
160 /* Look in the type of the source to see if it contains the
161 type of the target as a superclass. If so, we'll need to
162 offset the pointer rather than just change its type. */
163 struct type *t1 = TYPE_TARGET_TYPE (type);
164 struct type *t2 = TYPE_TARGET_TYPE (VALUE_TYPE (arg2));
165 if ( TYPE_CODE (t1) == TYPE_CODE_STRUCT
166 && TYPE_CODE (t2) == TYPE_CODE_STRUCT
167 && TYPE_NAME (t1) != 0) /* if name unknown, can't have supercl */
169 value v = search_struct_field (type_name_no_tag (t1),
170 value_ind (arg2), 0, t2, 1);
174 VALUE_TYPE (v) = type;
178 /* No superclass found, just fall through to change ptr type. */
180 VALUE_TYPE (arg2) = type;
183 else if (VALUE_LVAL (arg2) == lval_memory)
185 return value_at_lazy (type, VALUE_ADDRESS (arg2) + VALUE_OFFSET (arg2));
187 else if (code1 == TYPE_CODE_VOID)
189 return value_zero (builtin_type_void, not_lval);
193 error ("Invalid cast.");
198 /* Create a value of type TYPE that is zero, and return it. */
201 value_zero (type, lv)
205 register value val = allocate_value (type);
207 memset (VALUE_CONTENTS (val), 0, TYPE_LENGTH (type));
208 VALUE_LVAL (val) = lv;
213 /* Return a value with type TYPE located at ADDR.
215 Call value_at only if the data needs to be fetched immediately;
216 if we can be 'lazy' and defer the fetch, perhaps indefinately, call
217 value_at_lazy instead. value_at_lazy simply records the address of
218 the data and sets the lazy-evaluation-required flag. The lazy flag
219 is tested in the VALUE_CONTENTS macro, which is used if and when
220 the contents are actually required. */
223 value_at (type, addr)
227 register value val = allocate_value (type);
229 read_memory (addr, VALUE_CONTENTS_RAW (val), TYPE_LENGTH (type));
231 VALUE_LVAL (val) = lval_memory;
232 VALUE_ADDRESS (val) = addr;
237 /* Return a lazy value with type TYPE located at ADDR (cf. value_at). */
240 value_at_lazy (type, addr)
244 register value val = allocate_value (type);
246 VALUE_LVAL (val) = lval_memory;
247 VALUE_ADDRESS (val) = addr;
248 VALUE_LAZY (val) = 1;
253 /* Called only from the VALUE_CONTENTS macro, if the current data for
254 a variable needs to be loaded into VALUE_CONTENTS(VAL). Fetches the
255 data from the user's process, and clears the lazy flag to indicate
256 that the data in the buffer is valid.
258 If the value is zero-length, we avoid calling read_memory, which would
259 abort. We mark the value as fetched anyway -- all 0 bytes of it.
261 This function returns a value because it is used in the VALUE_CONTENTS
262 macro as part of an expression, where a void would not work. The
266 value_fetch_lazy (val)
269 CORE_ADDR addr = VALUE_ADDRESS (val) + VALUE_OFFSET (val);
271 if (TYPE_LENGTH (VALUE_TYPE (val)))
272 read_memory (addr, VALUE_CONTENTS_RAW (val),
273 TYPE_LENGTH (VALUE_TYPE (val)));
274 VALUE_LAZY (val) = 0;
279 /* Store the contents of FROMVAL into the location of TOVAL.
280 Return a new value with the location of TOVAL and contents of FROMVAL. */
283 value_assign (toval, fromval)
284 register value toval, fromval;
286 register struct type *type = VALUE_TYPE (toval);
288 char raw_buffer[MAX_REGISTER_RAW_SIZE];
289 char virtual_buffer[MAX_REGISTER_VIRTUAL_SIZE];
292 COERCE_ARRAY (fromval);
295 if (VALUE_LVAL (toval) != lval_internalvar)
296 fromval = value_cast (type, fromval);
298 /* If TOVAL is a special machine register requiring conversion
299 of program values to a special raw format,
300 convert FROMVAL's contents now, with result in `raw_buffer',
301 and set USE_BUFFER to the number of bytes to write. */
303 if (VALUE_REGNO (toval) >= 0
304 && REGISTER_CONVERTIBLE (VALUE_REGNO (toval)))
306 int regno = VALUE_REGNO (toval);
307 if (VALUE_TYPE (fromval) != REGISTER_VIRTUAL_TYPE (regno))
308 fromval = value_cast (REGISTER_VIRTUAL_TYPE (regno), fromval);
309 memcpy (virtual_buffer, VALUE_CONTENTS (fromval),
310 REGISTER_VIRTUAL_SIZE (regno));
311 REGISTER_CONVERT_TO_RAW (regno, virtual_buffer, raw_buffer);
312 use_buffer = REGISTER_RAW_SIZE (regno);
315 switch (VALUE_LVAL (toval))
317 case lval_internalvar:
318 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
321 case lval_internalvar_component:
322 set_internalvar_component (VALUE_INTERNALVAR (toval),
323 VALUE_OFFSET (toval),
324 VALUE_BITPOS (toval),
325 VALUE_BITSIZE (toval),
330 if (VALUE_BITSIZE (toval))
332 int v; /* FIXME, this won't work for large bitfields */
333 read_memory (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
334 (char *) &v, sizeof v);
335 modify_field ((char *) &v, (int) value_as_long (fromval),
336 VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
337 write_memory (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
338 (char *)&v, sizeof v);
341 write_memory (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
342 raw_buffer, use_buffer);
344 write_memory (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
345 VALUE_CONTENTS (fromval), TYPE_LENGTH (type));
349 if (VALUE_BITSIZE (toval))
353 read_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
354 (char *) &v, sizeof v);
355 modify_field ((char *) &v, (int) value_as_long (fromval),
356 VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
357 write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
358 (char *) &v, sizeof v);
361 write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
362 raw_buffer, use_buffer);
365 /* Do any conversion necessary when storing this type to more
366 than one register. */
367 #ifdef REGISTER_CONVERT_FROM_TYPE
368 memcpy (raw_buffer, VALUE_CONTENTS (fromval), TYPE_LENGTH (type));
369 REGISTER_CONVERT_FROM_TYPE(VALUE_REGNO (toval), type, raw_buffer);
370 write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
371 raw_buffer, TYPE_LENGTH (type));
373 write_register_bytes (VALUE_ADDRESS (toval) + VALUE_OFFSET (toval),
374 VALUE_CONTENTS (fromval), TYPE_LENGTH (type));
379 case lval_reg_frame_relative:
381 /* value is stored in a series of registers in the frame
382 specified by the structure. Copy that value out, modify
383 it, and copy it back in. */
384 int amount_to_copy = (VALUE_BITSIZE (toval) ? 1 : TYPE_LENGTH (type));
385 int reg_size = REGISTER_RAW_SIZE (VALUE_FRAME_REGNUM (toval));
386 int byte_offset = VALUE_OFFSET (toval) % reg_size;
387 int reg_offset = VALUE_OFFSET (toval) / reg_size;
389 char *buffer = (char *) alloca (amount_to_copy);
393 /* Figure out which frame this is in currently. */
394 for (frame = get_current_frame ();
395 frame && FRAME_FP (frame) != VALUE_FRAME (toval);
396 frame = get_prev_frame (frame))
400 error ("Value being assigned to is no longer active.");
402 amount_to_copy += (reg_size - amount_to_copy % reg_size);
405 for ((regno = VALUE_FRAME_REGNUM (toval) + reg_offset,
407 amount_copied < amount_to_copy;
408 amount_copied += reg_size, regno++)
410 get_saved_register (buffer + amount_copied,
411 (int *)NULL, (CORE_ADDR *)NULL,
412 frame, regno, (enum lval_type *)NULL);
415 /* Modify what needs to be modified. */
416 if (VALUE_BITSIZE (toval))
417 modify_field (buffer + byte_offset,
418 (int) value_as_long (fromval),
419 VALUE_BITPOS (toval), VALUE_BITSIZE (toval));
421 memcpy (buffer + byte_offset, raw_buffer, use_buffer);
423 memcpy (buffer + byte_offset, VALUE_CONTENTS (fromval),
427 for ((regno = VALUE_FRAME_REGNUM (toval) + reg_offset,
429 amount_copied < amount_to_copy;
430 amount_copied += reg_size, regno++)
436 /* Just find out where to put it. */
437 get_saved_register ((char *)NULL,
438 &optim, &addr, frame, regno, &lval);
441 error ("Attempt to assign to a value that was optimized out.");
442 if (lval == lval_memory)
443 write_memory (addr, buffer + amount_copied, reg_size);
444 else if (lval == lval_register)
445 write_register_bytes (addr, buffer + amount_copied, reg_size);
447 error ("Attempt to assign to an unmodifiable value.");
454 error ("Left side of = operation is not an lvalue.");
457 /* Return a value just like TOVAL except with the contents of FROMVAL
458 (except in the case of the type if TOVAL is an internalvar). */
460 if (VALUE_LVAL (toval) == lval_internalvar
461 || VALUE_LVAL (toval) == lval_internalvar_component)
463 type = VALUE_TYPE (fromval);
466 val = allocate_value (type);
467 memcpy (val, toval, VALUE_CONTENTS_RAW (val) - (char *) val);
468 memcpy (VALUE_CONTENTS_RAW (val), VALUE_CONTENTS (fromval),
470 VALUE_TYPE (val) = type;
475 /* Extend a value VAL to COUNT repetitions of its type. */
478 value_repeat (arg1, count)
484 if (VALUE_LVAL (arg1) != lval_memory)
485 error ("Only values in memory can be extended with '@'.");
487 error ("Invalid number %d of repetitions.", count);
489 val = allocate_repeat_value (VALUE_TYPE (arg1), count);
491 read_memory (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1),
492 VALUE_CONTENTS_RAW (val),
493 TYPE_LENGTH (VALUE_TYPE (val)) * count);
494 VALUE_LVAL (val) = lval_memory;
495 VALUE_ADDRESS (val) = VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1);
501 value_of_variable (var)
506 val = read_var_value (var, (FRAME) 0);
508 error ("Address of symbol \"%s\" is unknown.", SYMBOL_SOURCE_NAME (var));
512 /* Given a value which is an array, return a value which is a pointer to its
513 first element, regardless of whether or not the array has a nonzero lower
516 FIXME: A previous comment here indicated that this routine should be
517 substracting the array's lower bound. It's not clear to me that this
518 is correct. Given an array subscripting operation, it would certainly
519 work to do the adjustment here, essentially computing:
521 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
523 However I believe a more appropriate and logical place to account for
524 the lower bound is to do so in value_subscript, essentially computing:
526 (&array[0] + ((index - lowerbound) * sizeof array[0]))
528 As further evidence consider what would happen with operations other
529 than array subscripting, where the caller would get back a value that
530 had an address somewhere before the actual first element of the array,
531 and the information about the lower bound would be lost because of
532 the coercion to pointer type.
536 value_coerce_array (arg1)
539 register struct type *type;
541 if (VALUE_LVAL (arg1) != lval_memory)
542 error ("Attempt to take address of value not located in memory.");
544 /* Get type of elements. */
545 if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_ARRAY)
546 type = TYPE_TARGET_TYPE (VALUE_TYPE (arg1));
548 /* A phony array made by value_repeat.
549 Its type is the type of the elements, not an array type. */
550 type = VALUE_TYPE (arg1);
552 return value_from_longest (lookup_pointer_type (type),
553 (LONGEST) (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1)));
556 /* Given a value which is a function, return a value which is a pointer
560 value_coerce_function (arg1)
564 if (VALUE_LVAL (arg1) != lval_memory)
565 error ("Attempt to take address of value not located in memory.");
567 return value_from_longest (lookup_pointer_type (VALUE_TYPE (arg1)),
568 (LONGEST) (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1)));
571 /* Return a pointer value for the object for which ARG1 is the contents. */
577 struct type *type = VALUE_TYPE (arg1);
578 if (TYPE_CODE (type) == TYPE_CODE_REF)
580 /* Copy the value, but change the type from (T&) to (T*).
581 We keep the same location information, which is efficient,
582 and allows &(&X) to get the location containing the reference. */
583 value arg2 = value_copy (arg1);
584 VALUE_TYPE (arg2) = lookup_pointer_type (TYPE_TARGET_TYPE (type));
587 if (VALUE_REPEATED (arg1)
588 || TYPE_CODE (type) == TYPE_CODE_ARRAY)
589 return value_coerce_array (arg1);
590 if (TYPE_CODE (type) == TYPE_CODE_FUNC)
591 return value_coerce_function (arg1);
593 if (VALUE_LVAL (arg1) != lval_memory)
594 error ("Attempt to take address of value not located in memory.");
596 return value_from_longest (lookup_pointer_type (type),
597 (LONGEST) (VALUE_ADDRESS (arg1) + VALUE_OFFSET (arg1)));
600 /* Given a value of a pointer type, apply the C unary * operator to it. */
608 if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_MEMBER)
609 error ("not implemented: member types in value_ind");
611 /* Allow * on an integer so we can cast it to whatever we want.
612 This returns an int, which seems like the most C-like thing
613 to do. "long long" variables are rare enough that
614 BUILTIN_TYPE_LONGEST would seem to be a mistake. */
615 if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_INT)
616 return value_at (builtin_type_int,
617 (CORE_ADDR) value_as_long (arg1));
618 else if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_PTR)
619 return value_at_lazy (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)),
620 value_as_pointer (arg1));
621 error ("Attempt to take contents of a non-pointer value.");
622 return 0; /* For lint -- never reached */
625 /* Pushing small parts of stack frames. */
627 /* Push one word (the size of object that a register holds). */
630 push_word (sp, buffer)
632 REGISTER_TYPE buffer;
634 register int len = sizeof (REGISTER_TYPE);
636 SWAP_TARGET_AND_HOST (&buffer, len);
639 write_memory (sp, (char *)&buffer, len);
640 #else /* stack grows upward */
641 write_memory (sp, (char *)&buffer, len);
643 #endif /* stack grows upward */
648 /* Push LEN bytes with data at BUFFER. */
651 push_bytes (sp, buffer, len)
658 write_memory (sp, buffer, len);
659 #else /* stack grows upward */
660 write_memory (sp, buffer, len);
662 #endif /* stack grows upward */
667 /* Push onto the stack the specified value VALUE. */
671 register CORE_ADDR sp;
674 register int len = TYPE_LENGTH (VALUE_TYPE (arg));
678 write_memory (sp, VALUE_CONTENTS (arg), len);
679 #else /* stack grows upward */
680 write_memory (sp, VALUE_CONTENTS (arg), len);
682 #endif /* stack grows upward */
687 /* Perform the standard coercions that are specified
688 for arguments to be passed to C functions. */
691 value_arg_coerce (arg)
694 register struct type *type;
697 #if 1 /* FIXME: This is only a temporary patch. -fnf */
698 if (VALUE_REPEATED (arg)
699 || TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_ARRAY)
700 arg = value_coerce_array (arg);
701 if (TYPE_CODE (VALUE_TYPE (arg)) == TYPE_CODE_FUNC)
702 arg = value_coerce_function (arg);
705 type = VALUE_TYPE (arg);
707 if (TYPE_CODE (type) == TYPE_CODE_INT
708 && TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
709 return value_cast (builtin_type_int, arg);
711 if (TYPE_CODE (type) == TYPE_CODE_FLT
712 && TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_double))
713 return value_cast (builtin_type_double, arg);
718 /* Push the value ARG, first coercing it as an argument
722 value_arg_push (sp, arg)
723 register CORE_ADDR sp;
726 return value_push (sp, value_arg_coerce (arg));
729 /* Determine a function's address and its return type from its value.
730 Calls error() if the function is not valid for calling. */
733 find_function_addr (function, retval_type)
735 struct type **retval_type;
737 register struct type *ftype = VALUE_TYPE (function);
738 register enum type_code code = TYPE_CODE (ftype);
739 struct type *value_type;
742 /* If it's a member function, just look at the function
745 /* Determine address to call. */
746 if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
748 funaddr = VALUE_ADDRESS (function);
749 value_type = TYPE_TARGET_TYPE (ftype);
751 else if (code == TYPE_CODE_PTR)
753 funaddr = value_as_pointer (function);
754 if (TYPE_CODE (TYPE_TARGET_TYPE (ftype)) == TYPE_CODE_FUNC
755 || TYPE_CODE (TYPE_TARGET_TYPE (ftype)) == TYPE_CODE_METHOD)
756 value_type = TYPE_TARGET_TYPE (TYPE_TARGET_TYPE (ftype));
758 value_type = builtin_type_int;
760 else if (code == TYPE_CODE_INT)
762 /* Handle the case of functions lacking debugging info.
763 Their values are characters since their addresses are char */
764 if (TYPE_LENGTH (ftype) == 1)
765 funaddr = value_as_pointer (value_addr (function));
767 /* Handle integer used as address of a function. */
768 funaddr = (CORE_ADDR) value_as_long (function);
770 value_type = builtin_type_int;
773 error ("Invalid data type for function to be called.");
775 *retval_type = value_type;
779 #if defined (CALL_DUMMY)
780 /* All this stuff with a dummy frame may seem unnecessarily complicated
781 (why not just save registers in GDB?). The purpose of pushing a dummy
782 frame which looks just like a real frame is so that if you call a
783 function and then hit a breakpoint (get a signal, etc), "backtrace"
784 will look right. Whether the backtrace needs to actually show the
785 stack at the time the inferior function was called is debatable, but
786 it certainly needs to not display garbage. So if you are contemplating
787 making dummy frames be different from normal frames, consider that. */
789 /* Perform a function call in the inferior.
790 ARGS is a vector of values of arguments (NARGS of them).
791 FUNCTION is a value, the function to be called.
792 Returns a value representing what the function returned.
793 May fail to return, if a breakpoint or signal is hit
794 during the execution of the function. */
797 call_function_by_hand (function, nargs, args)
802 register CORE_ADDR sp;
805 /* CALL_DUMMY is an array of words (REGISTER_TYPE), but each word
806 is in host byte order. It is switched to target byte order before calling
808 static REGISTER_TYPE dummy[] = CALL_DUMMY;
809 REGISTER_TYPE dummy1[sizeof dummy / sizeof (REGISTER_TYPE)];
811 struct type *value_type;
812 unsigned char struct_return;
813 CORE_ADDR struct_addr;
814 struct inferior_status inf_status;
815 struct cleanup *old_chain;
820 if (!target_has_execution)
823 save_inferior_status (&inf_status, 1);
824 old_chain = make_cleanup (restore_inferior_status, &inf_status);
826 /* PUSH_DUMMY_FRAME is responsible for saving the inferior registers
827 (and POP_FRAME for restoring them). (At least on most machines)
828 they are saved on the stack in the inferior. */
831 old_sp = sp = read_sp ();
833 #if 1 INNER_THAN 2 /* Stack grows down */
836 #else /* Stack grows up */
841 funaddr = find_function_addr (function, &value_type);
844 struct block *b = block_for_pc (funaddr);
845 /* If compiled without -g, assume GCC. */
846 using_gcc = b == NULL || BLOCK_GCC_COMPILED (b);
849 /* Are we returning a value using a structure return or a normal
852 struct_return = using_struct_return (function, funaddr, value_type,
855 /* Create a call sequence customized for this function
856 and the number of arguments for it. */
857 memcpy (dummy1, dummy, sizeof dummy);
858 for (i = 0; i < sizeof dummy / sizeof (REGISTER_TYPE); i++)
859 SWAP_TARGET_AND_HOST (&dummy1[i], sizeof (REGISTER_TYPE));
861 #ifdef GDB_TARGET_IS_HPPA
862 real_pc = FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
863 value_type, using_gcc);
865 FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
866 value_type, using_gcc);
870 #if CALL_DUMMY_LOCATION == ON_STACK
871 write_memory (start_sp, (char *)dummy1, sizeof dummy);
873 #else /* Not on stack. */
874 #if CALL_DUMMY_LOCATION == BEFORE_TEXT_END
875 /* Convex Unix prohibits executing in the stack segment. */
876 /* Hope there is empty room at the top of the text segment. */
878 extern CORE_ADDR text_end;
881 for (start_sp = text_end - sizeof dummy; start_sp < text_end; ++start_sp)
882 if (read_memory_integer (start_sp, 1) != 0)
883 error ("text segment full -- no place to put call");
886 start_sp = text_end - sizeof dummy;
887 write_memory (start_sp, (char *)dummy1, sizeof dummy);
889 #else /* After text_end. */
891 extern CORE_ADDR text_end;
895 errcode = target_write_memory (start_sp, (char *)dummy1, sizeof dummy);
897 error ("Cannot write text segment -- call_function failed");
899 #endif /* After text_end. */
900 #endif /* Not on stack. */
903 sp = old_sp; /* It really is used, for some ifdef's... */
907 /* If stack grows down, we must leave a hole at the top. */
911 /* Reserve space for the return structure to be written on the
912 stack, if necessary */
915 len += TYPE_LENGTH (value_type);
917 for (i = nargs - 1; i >= 0; i--)
918 len += TYPE_LENGTH (VALUE_TYPE (value_arg_coerce (args[i])));
919 #ifdef CALL_DUMMY_STACK_ADJUST
920 len += CALL_DUMMY_STACK_ADJUST;
923 sp -= STACK_ALIGN (len) - len;
925 sp += STACK_ALIGN (len) - len;
928 #endif /* STACK_ALIGN */
930 /* Reserve space for the return structure to be written on the
931 stack, if necessary */
936 sp -= TYPE_LENGTH (value_type);
940 sp += TYPE_LENGTH (value_type);
944 #if defined (REG_STRUCT_HAS_ADDR)
946 /* This is a machine like the sparc, where we need to pass a pointer
947 to the structure, not the structure itself. */
948 if (REG_STRUCT_HAS_ADDR (using_gcc))
949 for (i = nargs - 1; i >= 0; i--)
950 if (TYPE_CODE (VALUE_TYPE (args[i])) == TYPE_CODE_STRUCT)
953 #if !(1 INNER_THAN 2)
954 /* The stack grows up, so the address of the thing we push
955 is the stack pointer before we push it. */
958 /* Push the structure. */
959 sp = value_push (sp, args[i]);
961 /* The stack grows down, so the address of the thing we push
962 is the stack pointer after we push it. */
965 /* The value we're going to pass is the address of the thing
967 args[i] = value_from_longest (lookup_pointer_type (value_type),
971 #endif /* REG_STRUCT_HAS_ADDR. */
973 #ifdef PUSH_ARGUMENTS
974 PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr);
975 #else /* !PUSH_ARGUMENTS */
976 for (i = nargs - 1; i >= 0; i--)
977 sp = value_arg_push (sp, args[i]);
978 #endif /* !PUSH_ARGUMENTS */
980 #ifdef CALL_DUMMY_STACK_ADJUST
982 sp -= CALL_DUMMY_STACK_ADJUST;
984 sp += CALL_DUMMY_STACK_ADJUST;
986 #endif /* CALL_DUMMY_STACK_ADJUST */
988 /* Store the address at which the structure is supposed to be
989 written. Note that this (and the code which reserved the space
990 above) assumes that gcc was used to compile this function. Since
991 it doesn't cost us anything but space and if the function is pcc
992 it will ignore this value, we will make that assumption.
994 Also note that on some machines (like the sparc) pcc uses a
995 convention like gcc's. */
998 STORE_STRUCT_RETURN (struct_addr, sp);
1000 /* Write the stack pointer. This is here because the statements above
1001 might fool with it. On SPARC, this write also stores the register
1002 window into the right place in the new stack frame, which otherwise
1003 wouldn't happen. (See store_inferior_registers in sparc-nat.c.) */
1006 /* Figure out the value returned by the function. */
1008 char retbuf[REGISTER_BYTES];
1010 struct symbol *symbol;
1013 symbol = find_pc_function (funaddr);
1016 name = SYMBOL_SOURCE_NAME (symbol);
1020 /* Try the minimal symbols. */
1021 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
1025 name = SYMBOL_SOURCE_NAME (msymbol);
1031 sprintf (format, "at %s", local_hex_format ());
1033 sprintf (name, format, funaddr);
1036 /* Execute the stack dummy routine, calling FUNCTION.
1037 When it is done, discard the empty frame
1038 after storing the contents of all regs into retbuf. */
1039 run_stack_dummy (name, real_pc + CALL_DUMMY_START_OFFSET, retbuf);
1041 do_cleanups (old_chain);
1043 return value_being_returned (value_type, retbuf, struct_return);
1046 #else /* no CALL_DUMMY. */
1048 call_function_by_hand (function, nargs, args)
1053 error ("Cannot invoke functions on this machine.");
1055 #endif /* no CALL_DUMMY. */
1058 /* Create a value for an array by allocating space in the inferior, copying
1059 the data into that space, and then setting up an array value.
1061 The array bounds are set from LOWBOUND and HIGHBOUND, and the array is
1062 populated from the values passed in ELEMVEC.
1064 The element type of the array is inherited from the type of the
1065 first element, and all elements must have the same size (though we
1066 don't currently enforce any restriction on their types). */
1069 value_array (lowbound, highbound, elemvec)
1078 struct type *rangetype;
1079 struct type *arraytype;
1082 /* Validate that the bounds are reasonable and that each of the elements
1083 have the same size. */
1085 nelem = highbound - lowbound + 1;
1088 error ("bad array bounds (%d, %d)", lowbound, highbound);
1090 typelength = TYPE_LENGTH (VALUE_TYPE (elemvec[0]));
1091 for (idx = 0; idx < nelem; idx++)
1093 if (TYPE_LENGTH (VALUE_TYPE (elemvec[idx])) != typelength)
1095 error ("array elements must all be the same size");
1099 /* Allocate space to store the array in the inferior, and then initialize
1100 it by copying in each element. FIXME: Is it worth it to create a
1101 local buffer in which to collect each value and then write all the
1102 bytes in one operation? */
1104 addr = allocate_space_in_inferior (nelem * typelength);
1105 for (idx = 0; idx < nelem; idx++)
1107 write_memory (addr + (idx * typelength), VALUE_CONTENTS (elemvec[idx]),
1111 /* Create the array type and set up an array value to be evaluated lazily. */
1113 rangetype = create_range_type ((struct type *) NULL, builtin_type_int,
1114 lowbound, highbound);
1115 arraytype = create_array_type ((struct type *) NULL,
1116 VALUE_TYPE (elemvec[0]), rangetype);
1117 val = value_at_lazy (arraytype, addr);
1121 /* Create a value for a string constant by allocating space in the inferior,
1122 copying the data into that space, and returning the address with type
1123 TYPE_CODE_STRING. PTR points to the string constant data; LEN is number
1125 Note that string types are like array of char types with a lower bound of
1126 zero and an upper bound of LEN - 1. Also note that the string may contain
1127 embedded null bytes. */
1130 value_string (ptr, len)
1135 struct type *rangetype;
1136 struct type *stringtype;
1139 /* Allocate space to store the string in the inferior, and then
1140 copy LEN bytes from PTR in gdb to that address in the inferior. */
1142 addr = allocate_space_in_inferior (len);
1143 write_memory (addr, ptr, len);
1145 /* Create the string type and set up a string value to be evaluated
1148 rangetype = create_range_type ((struct type *) NULL, builtin_type_int,
1150 stringtype = create_string_type ((struct type *) NULL, rangetype);
1151 val = value_at_lazy (stringtype, addr);
1155 /* Compare two argument lists and return the position in which they differ,
1158 STATICP is nonzero if the T1 argument list came from a
1159 static member function.
1161 For non-static member functions, we ignore the first argument,
1162 which is the type of the instance variable. This is because we want
1163 to handle calls with objects from derived classes. This is not
1164 entirely correct: we should actually check to make sure that a
1165 requested operation is type secure, shouldn't we? FIXME. */
1168 typecmp (staticp, t1, t2)
1177 if (staticp && t1 == 0)
1181 if (TYPE_CODE (t1[0]) == TYPE_CODE_VOID) return 0;
1182 if (t1[!staticp] == 0) return 0;
1183 for (i = !staticp; t1[i] && TYPE_CODE (t1[i]) != TYPE_CODE_VOID; i++)
1187 if (TYPE_CODE (t1[i]) == TYPE_CODE_REF
1188 && TYPE_TARGET_TYPE (t1[i]) == VALUE_TYPE (t2[i]))
1190 if (TYPE_CODE (t1[i]) != TYPE_CODE (VALUE_TYPE (t2[i])))
1193 if (!t1[i]) return 0;
1194 return t2[i] ? i+1 : 0;
1197 /* Helper function used by value_struct_elt to recurse through baseclasses.
1198 Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
1199 and search in it assuming it has (class) type TYPE.
1200 If found, return value, else return NULL.
1202 If LOOKING_FOR_BASECLASS, then instead of looking for struct fields,
1203 look for a baseclass named NAME. */
1206 search_struct_field (name, arg1, offset, type, looking_for_baseclass)
1208 register value arg1;
1210 register struct type *type;
1211 int looking_for_baseclass;
1215 check_stub_type (type);
1217 if (! looking_for_baseclass)
1218 for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
1220 char *t_field_name = TYPE_FIELD_NAME (type, i);
1222 if (t_field_name && STREQ (t_field_name, name))
1225 if (TYPE_FIELD_STATIC (type, i))
1227 char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (type, i);
1228 struct symbol *sym =
1229 lookup_symbol (phys_name, 0, VAR_NAMESPACE, 0, NULL);
1231 error ("Internal error: could not find physical static variable named %s",
1233 v = value_at (TYPE_FIELD_TYPE (type, i),
1234 (CORE_ADDR)SYMBOL_BLOCK_VALUE (sym));
1237 v = value_primitive_field (arg1, offset, i, type);
1239 error("there is no field named %s", name);
1244 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
1247 /* If we are looking for baseclasses, this is what we get when we
1248 hit them. But it could happen that the base part's member name
1249 is not yet filled in. */
1250 int found_baseclass = (looking_for_baseclass
1251 && TYPE_BASECLASS_NAME (type, i) != NULL
1252 && STREQ (name, TYPE_BASECLASS_NAME (type, i)));
1254 if (BASETYPE_VIA_VIRTUAL (type, i))
1257 /* Fix to use baseclass_offset instead. FIXME */
1258 baseclass_addr (type, i, VALUE_CONTENTS (arg1) + offset,
1261 error ("virtual baseclass botch");
1262 if (found_baseclass)
1264 v = search_struct_field (name, v2, 0, TYPE_BASECLASS (type, i),
1265 looking_for_baseclass);
1267 else if (found_baseclass)
1268 v = value_primitive_field (arg1, offset, i, type);
1270 v = search_struct_field (name, arg1,
1271 offset + TYPE_BASECLASS_BITPOS (type, i) / 8,
1272 TYPE_BASECLASS (type, i),
1273 looking_for_baseclass);
1279 /* Helper function used by value_struct_elt to recurse through baseclasses.
1280 Look for a field NAME in ARG1. Adjust the address of ARG1 by OFFSET bytes,
1281 and search in it assuming it has (class) type TYPE.
1282 If found, return value, else return NULL. */
1285 search_struct_method (name, arg1p, args, offset, static_memfuncp, type)
1287 register value *arg1p, *args;
1288 int offset, *static_memfuncp;
1289 register struct type *type;
1293 check_stub_type (type);
1294 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1296 char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1297 if (t_field_name && STREQ (t_field_name, name))
1299 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
1300 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
1302 if (j > 0 && args == 0)
1303 error ("cannot resolve overloaded method `%s'", name);
1306 if (TYPE_FN_FIELD_STUB (f, j))
1307 check_stub_method (type, i, j);
1308 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
1309 TYPE_FN_FIELD_ARGS (f, j), args))
1311 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
1312 return (value)value_virtual_fn_field (arg1p, f, j, type, offset);
1313 if (TYPE_FN_FIELD_STATIC_P (f, j) && static_memfuncp)
1314 *static_memfuncp = 1;
1315 return (value)value_fn_field (arg1p, f, j, type, offset);
1322 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
1327 if (BASETYPE_VIA_VIRTUAL (type, i))
1329 base_offset = baseclass_offset (type, i, *arg1p, offset);
1330 if (base_offset == -1)
1331 error ("virtual baseclass botch");
1335 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
1337 v = search_struct_method (name, arg1p, args, base_offset + offset,
1338 static_memfuncp, TYPE_BASECLASS (type, i));
1341 /* FIXME-bothner: Why is this commented out? Why is it here? */
1342 /* *arg1p = arg1_tmp;*/
1349 /* Given *ARGP, a value of type (pointer to a)* structure/union,
1350 extract the component named NAME from the ultimate target structure/union
1351 and return it as a value with its appropriate type.
1352 ERR is used in the error message if *ARGP's type is wrong.
1354 C++: ARGS is a list of argument types to aid in the selection of
1355 an appropriate method. Also, handle derived types.
1357 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
1358 where the truthvalue of whether the function that was resolved was
1359 a static member function or not is stored.
1361 ERR is an error message to be printed in case the field is not found. */
1364 value_struct_elt (argp, args, name, static_memfuncp, err)
1365 register value *argp, *args;
1367 int *static_memfuncp;
1370 register struct type *t;
1373 COERCE_ARRAY (*argp);
1375 t = VALUE_TYPE (*argp);
1377 /* Follow pointers until we get to a non-pointer. */
1379 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
1381 *argp = value_ind (*argp);
1382 /* Don't coerce fn pointer to fn and then back again! */
1383 if (TYPE_CODE (VALUE_TYPE (*argp)) != TYPE_CODE_FUNC)
1384 COERCE_ARRAY (*argp);
1385 t = VALUE_TYPE (*argp);
1388 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
1389 error ("not implemented: member type in value_struct_elt");
1391 if ( TYPE_CODE (t) != TYPE_CODE_STRUCT
1392 && TYPE_CODE (t) != TYPE_CODE_UNION)
1393 error ("Attempt to extract a component of a value that is not a %s.", err);
1395 /* Assume it's not, unless we see that it is. */
1396 if (static_memfuncp)
1397 *static_memfuncp =0;
1401 /* if there are no arguments ...do this... */
1403 /* Try as a field first, because if we succeed, there
1404 is less work to be done. */
1405 v = search_struct_field (name, *argp, 0, t, 0);
1409 /* C++: If it was not found as a data field, then try to
1410 return it as a pointer to a method. */
1412 if (destructor_name_p (name, t))
1413 error ("Cannot get value of destructor");
1415 v = search_struct_method (name, argp, args, 0, static_memfuncp, t);
1419 if (TYPE_NFN_FIELDS (t))
1420 error ("There is no member or method named %s.", name);
1422 error ("There is no member named %s.", name);
1427 if (destructor_name_p (name, t))
1431 /* destructors are a special case. */
1432 return (value)value_fn_field (NULL, TYPE_FN_FIELDLIST1 (t, 0),
1433 TYPE_FN_FIELDLIST_LENGTH (t, 0),
1438 error ("destructor should not have any argument");
1442 v = search_struct_method (name, argp, args, 0, static_memfuncp, t);
1446 /* See if user tried to invoke data as function. If so,
1447 hand it back. If it's not callable (i.e., a pointer to function),
1448 gdb should give an error. */
1449 v = search_struct_field (name, *argp, 0, t, 0);
1453 error ("Structure has no component named %s.", name);
1457 /* C++: return 1 is NAME is a legitimate name for the destructor
1458 of type TYPE. If TYPE does not have a destructor, or
1459 if NAME is inappropriate for TYPE, an error is signaled. */
1461 destructor_name_p (name, type)
1463 const struct type *type;
1465 /* destructors are a special case. */
1469 char *dname = type_name_no_tag (type);
1470 if (!STREQ (dname, name+1))
1471 error ("name of destructor must equal name of class");
1478 /* Helper function for check_field: Given TYPE, a structure/union,
1479 return 1 if the component named NAME from the ultimate
1480 target structure/union is defined, otherwise, return 0. */
1483 check_field_in (type, name)
1484 register struct type *type;
1489 for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
1491 char *t_field_name = TYPE_FIELD_NAME (type, i);
1492 if (t_field_name && STREQ (t_field_name, name))
1496 /* C++: If it was not found as a data field, then try to
1497 return it as a pointer to a method. */
1499 /* Destructors are a special case. */
1500 if (destructor_name_p (name, type))
1503 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
1505 if (STREQ (TYPE_FN_FIELDLIST_NAME (type, i), name))
1509 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
1510 if (check_field_in (TYPE_BASECLASS (type, i), name))
1517 /* C++: Given ARG1, a value of type (pointer to a)* structure/union,
1518 return 1 if the component named NAME from the ultimate
1519 target structure/union is defined, otherwise, return 0. */
1522 check_field (arg1, name)
1523 register value arg1;
1526 register struct type *t;
1528 COERCE_ARRAY (arg1);
1530 t = VALUE_TYPE (arg1);
1532 /* Follow pointers until we get to a non-pointer. */
1534 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
1535 t = TYPE_TARGET_TYPE (t);
1537 if (TYPE_CODE (t) == TYPE_CODE_MEMBER)
1538 error ("not implemented: member type in check_field");
1540 if ( TYPE_CODE (t) != TYPE_CODE_STRUCT
1541 && TYPE_CODE (t) != TYPE_CODE_UNION)
1542 error ("Internal error: `this' is not an aggregate");
1544 return check_field_in (t, name);
1547 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
1548 return the address of this member as a "pointer to member"
1549 type. If INTYPE is non-null, then it will be the type
1550 of the member we are looking for. This will help us resolve
1551 "pointers to member functions". This function is used
1552 to resolve user expressions of the form "DOMAIN::NAME". */
1555 value_struct_elt_for_reference (domain, offset, curtype, name, intype)
1556 struct type *domain, *curtype, *intype;
1560 register struct type *t = curtype;
1564 if ( TYPE_CODE (t) != TYPE_CODE_STRUCT
1565 && TYPE_CODE (t) != TYPE_CODE_UNION)
1566 error ("Internal error: non-aggregate type to value_struct_elt_for_reference");
1568 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
1570 char *t_field_name = TYPE_FIELD_NAME (t, i);
1572 if (t_field_name && STREQ (t_field_name, name))
1574 if (TYPE_FIELD_STATIC (t, i))
1576 char *phys_name = TYPE_FIELD_STATIC_PHYSNAME (t, i);
1577 struct symbol *sym =
1578 lookup_symbol (phys_name, 0, VAR_NAMESPACE, 0, NULL);
1580 error ("Internal error: could not find physical static variable named %s",
1582 return value_at (SYMBOL_TYPE (sym),
1583 (CORE_ADDR)SYMBOL_BLOCK_VALUE (sym));
1585 if (TYPE_FIELD_PACKED (t, i))
1586 error ("pointers to bitfield members not allowed");
1588 return value_from_longest
1589 (lookup_reference_type (lookup_member_type (TYPE_FIELD_TYPE (t, i),
1591 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
1595 /* C++: If it was not found as a data field, then try to
1596 return it as a pointer to a method. */
1598 /* Destructors are a special case. */
1599 if (destructor_name_p (name, t))
1601 error ("member pointers to destructors not implemented yet");
1604 /* Perform all necessary dereferencing. */
1605 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
1606 intype = TYPE_TARGET_TYPE (intype);
1608 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
1610 if (STREQ (TYPE_FN_FIELDLIST_NAME (t, i), name))
1612 int j = TYPE_FN_FIELDLIST_LENGTH (t, i);
1613 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
1615 if (intype == 0 && j > 1)
1616 error ("non-unique member `%s' requires type instantiation", name);
1620 if (TYPE_FN_FIELD_TYPE (f, j) == intype)
1623 error ("no member function matches that type instantiation");
1628 if (TYPE_FN_FIELD_STUB (f, j))
1629 check_stub_method (t, i, j);
1630 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
1632 return value_from_longest
1633 (lookup_reference_type
1634 (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
1636 (LONGEST) METHOD_PTR_FROM_VOFFSET
1637 (TYPE_FN_FIELD_VOFFSET (f, j)));
1641 struct symbol *s = lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
1642 0, VAR_NAMESPACE, 0, NULL);
1649 v = read_var_value (s, 0);
1651 VALUE_TYPE (v) = lookup_reference_type
1652 (lookup_member_type (TYPE_FN_FIELD_TYPE (f, j),
1660 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
1665 if (BASETYPE_VIA_VIRTUAL (t, i))
1668 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
1669 v = value_struct_elt_for_reference (domain,
1670 offset + base_offset,
1671 TYPE_BASECLASS (t, i),
1680 /* C++: return the value of the class instance variable, if one exists.
1681 Flag COMPLAIN signals an error if the request is made in an
1682 inappropriate context. */
1684 value_of_this (complain)
1687 extern FRAME selected_frame;
1688 struct symbol *func, *sym;
1691 static const char funny_this[] = "this";
1694 if (selected_frame == 0)
1696 error ("no frame selected");
1699 func = get_frame_function (selected_frame);
1703 error ("no `this' in nameless context");
1707 b = SYMBOL_BLOCK_VALUE (func);
1708 i = BLOCK_NSYMS (b);
1711 error ("no args, no `this'");
1714 /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
1715 symbol instead of the LOC_ARG one (if both exist). */
1716 sym = lookup_block_symbol (b, funny_this, VAR_NAMESPACE);
1720 error ("current stack frame not in method");
1725 this = read_var_value (sym, selected_frame);
1726 if (this == 0 && complain)
1727 error ("`this' argument at unknown address");