1 /* Perform an inferior function call, for GDB, the GNU debugger.
3 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
4 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
5 Free Software Foundation, Inc.
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., 51 Franklin Street, Fifth Floor,
22 Boston, MA 02110-1301, USA. */
25 #include "breakpoint.h"
29 #include "gdb_assert.h"
36 #include "gdb_string.h"
38 #include "dummy-frame.h"
40 /* NOTE: cagney/2003-04-16: What's the future of this code?
42 GDB needs an asynchronous expression evaluator, that means an
43 asynchronous inferior function call implementation, and that in
44 turn means restructuring the code so that it is event driven. */
46 /* How you should pass arguments to a function depends on whether it
47 was defined in K&R style or prototype style. If you define a
48 function using the K&R syntax that takes a `float' argument, then
49 callers must pass that argument as a `double'. If you define the
50 function using the prototype syntax, then you must pass the
51 argument as a `float', with no promotion.
53 Unfortunately, on certain older platforms, the debug info doesn't
54 indicate reliably how each function was defined. A function type's
55 TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
56 defined in prototype style. When calling a function whose
57 TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to
60 For modern targets, it is proper to assume that, if the prototype
61 flag is clear, that can be trusted: `float' arguments should be
62 promoted to `double'. For some older targets, if the prototype
63 flag is clear, that doesn't tell us anything. The default is to
64 trust the debug information; the user can override this behavior
65 with "set coerce-float-to-double 0". */
67 static int coerce_float_to_double_p
= 1;
69 show_coerce_float_to_double_p (struct ui_file
*file
, int from_tty
,
70 struct cmd_list_element
*c
, const char *value
)
72 fprintf_filtered (file
, _("\
73 Coercion of floats to doubles when calling functions is %s.\n"),
77 /* This boolean tells what gdb should do if a signal is received while
78 in a function called from gdb (call dummy). If set, gdb unwinds
79 the stack and restore the context to what as it was before the
82 The default is to stop in the frame where the signal was received. */
84 int unwind_on_signal_p
= 0;
86 show_unwind_on_signal_p (struct ui_file
*file
, int from_tty
,
87 struct cmd_list_element
*c
, const char *value
)
89 fprintf_filtered (file
, _("\
90 Unwinding of stack if a signal is received while in a call dummy is %s.\n"),
95 /* Perform the standard coercions that are specified
96 for arguments to be passed to C functions.
98 If PARAM_TYPE is non-NULL, it is the expected parameter type.
99 IS_PROTOTYPED is non-zero if the function declaration is prototyped. */
101 static struct value
*
102 value_arg_coerce (struct value
*arg
, struct type
*param_type
,
105 struct type
*arg_type
= check_typedef (value_type (arg
));
107 = param_type
? check_typedef (param_type
) : arg_type
;
109 switch (TYPE_CODE (type
))
113 struct value
*new_value
;
115 if (TYPE_CODE (arg_type
) == TYPE_CODE_REF
)
116 return value_cast_pointers (type
, arg
);
118 /* Cast the value to the reference's target type, and then
119 convert it back to a reference. This will issue an error
120 if the value was not previously in memory - in some cases
121 we should clearly be allowing this, but how? */
122 new_value
= value_cast (TYPE_TARGET_TYPE (type
), arg
);
123 new_value
= value_ref (new_value
);
130 /* If we don't have a prototype, coerce to integer type if necessary. */
133 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin_type_int
))
134 type
= builtin_type_int
;
136 /* Currently all target ABIs require at least the width of an integer
137 type for an argument. We may have to conditionalize the following
138 type coercion for future targets. */
139 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin_type_int
))
140 type
= builtin_type_int
;
143 if (!is_prototyped
&& coerce_float_to_double_p
)
145 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin_type_double
))
146 type
= builtin_type_double
;
147 else if (TYPE_LENGTH (type
) > TYPE_LENGTH (builtin_type_double
))
148 type
= builtin_type_long_double
;
152 type
= lookup_pointer_type (type
);
154 case TYPE_CODE_ARRAY
:
155 /* Arrays are coerced to pointers to their first element, unless
156 they are vectors, in which case we want to leave them alone,
157 because they are passed by value. */
158 if (current_language
->c_style_arrays
)
159 if (!TYPE_VECTOR (type
))
160 type
= lookup_pointer_type (TYPE_TARGET_TYPE (type
));
162 case TYPE_CODE_UNDEF
:
164 case TYPE_CODE_STRUCT
:
165 case TYPE_CODE_UNION
:
168 case TYPE_CODE_RANGE
:
169 case TYPE_CODE_STRING
:
170 case TYPE_CODE_BITSTRING
:
171 case TYPE_CODE_ERROR
:
172 case TYPE_CODE_MEMBER
:
173 case TYPE_CODE_METHOD
:
174 case TYPE_CODE_COMPLEX
:
179 return value_cast (type
, arg
);
182 /* Determine a function's address and its return type from its value.
183 Calls error() if the function is not valid for calling. */
186 find_function_addr (struct value
*function
, struct type
**retval_type
)
188 struct type
*ftype
= check_typedef (value_type (function
));
189 enum type_code code
= TYPE_CODE (ftype
);
190 struct type
*value_type
;
193 /* If it's a member function, just look at the function
196 /* Determine address to call. */
197 if (code
== TYPE_CODE_FUNC
|| code
== TYPE_CODE_METHOD
)
199 funaddr
= VALUE_ADDRESS (function
);
200 value_type
= TYPE_TARGET_TYPE (ftype
);
202 else if (code
== TYPE_CODE_PTR
)
204 funaddr
= value_as_address (function
);
205 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
206 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
207 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
209 funaddr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
212 value_type
= TYPE_TARGET_TYPE (ftype
);
215 value_type
= builtin_type_int
;
217 else if (code
== TYPE_CODE_INT
)
219 /* Handle the case of functions lacking debugging info.
220 Their values are characters since their addresses are char */
221 if (TYPE_LENGTH (ftype
) == 1)
222 funaddr
= value_as_address (value_addr (function
));
224 /* Handle integer used as address of a function. */
225 funaddr
= (CORE_ADDR
) value_as_long (function
);
227 value_type
= builtin_type_int
;
230 error (_("Invalid data type for function to be called."));
232 if (retval_type
!= NULL
)
233 *retval_type
= value_type
;
234 return funaddr
+ DEPRECATED_FUNCTION_START_OFFSET
;
237 /* Call breakpoint_auto_delete on the current contents of the bpstat
238 pointed to by arg (which is really a bpstat *). */
241 breakpoint_auto_delete_contents (void *arg
)
243 breakpoint_auto_delete (*(bpstat
*) arg
);
247 generic_push_dummy_code (struct gdbarch
*gdbarch
,
248 CORE_ADDR sp
, CORE_ADDR funaddr
, int using_gcc
,
249 struct value
**args
, int nargs
,
250 struct type
*value_type
,
251 CORE_ADDR
*real_pc
, CORE_ADDR
*bp_addr
)
253 /* Something here to findout the size of a breakpoint and then
254 allocate space for it on the stack. */
256 /* This code assumes frame align. */
257 gdb_assert (gdbarch_frame_align_p (gdbarch
));
258 /* Force the stack's alignment. The intent is to ensure that the SP
259 is aligned to at least a breakpoint instruction's boundary. */
260 sp
= gdbarch_frame_align (gdbarch
, sp
);
261 /* Allocate space for, and then position the breakpoint on the
263 if (gdbarch_inner_than (gdbarch
, 1, 2))
266 gdbarch_breakpoint_from_pc (gdbarch
, &bppc
, &bplen
);
267 sp
= gdbarch_frame_align (gdbarch
, sp
- bplen
);
269 /* Should the breakpoint size/location be re-computed here? */
274 gdbarch_breakpoint_from_pc (gdbarch
, bp_addr
, &bplen
);
275 sp
= gdbarch_frame_align (gdbarch
, sp
+ bplen
);
277 /* Inferior resumes at the function entry point. */
278 (*real_pc
) = funaddr
;
282 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
283 function returns to. */
286 push_dummy_code (struct gdbarch
*gdbarch
,
287 CORE_ADDR sp
, CORE_ADDR funaddr
, int using_gcc
,
288 struct value
**args
, int nargs
,
289 struct type
*value_type
,
290 CORE_ADDR
*real_pc
, CORE_ADDR
*bp_addr
)
292 if (gdbarch_push_dummy_code_p (gdbarch
))
293 return gdbarch_push_dummy_code (gdbarch
, sp
, funaddr
, using_gcc
,
294 args
, nargs
, value_type
, real_pc
, bp_addr
);
296 return generic_push_dummy_code (gdbarch
, sp
, funaddr
, using_gcc
,
297 args
, nargs
, value_type
, real_pc
, bp_addr
);
300 /* All this stuff with a dummy frame may seem unnecessarily complicated
301 (why not just save registers in GDB?). The purpose of pushing a dummy
302 frame which looks just like a real frame is so that if you call a
303 function and then hit a breakpoint (get a signal, etc), "backtrace"
304 will look right. Whether the backtrace needs to actually show the
305 stack at the time the inferior function was called is debatable, but
306 it certainly needs to not display garbage. So if you are contemplating
307 making dummy frames be different from normal frames, consider that. */
309 /* Perform a function call in the inferior.
310 ARGS is a vector of values of arguments (NARGS of them).
311 FUNCTION is a value, the function to be called.
312 Returns a value representing what the function returned.
313 May fail to return, if a breakpoint or signal is hit
314 during the execution of the function.
316 ARGS is modified to contain coerced values. */
319 call_function_by_hand (struct value
*function
, int nargs
, struct value
**args
)
322 CORE_ADDR dummy_addr
;
323 struct type
*values_type
;
324 unsigned char struct_return
;
325 CORE_ADDR struct_addr
= 0;
326 struct regcache
*retbuf
;
327 struct cleanup
*retbuf_cleanup
;
328 struct inferior_status
*inf_status
;
329 struct cleanup
*inf_status_cleanup
;
331 int using_gcc
; /* Set to version of gcc in use, or zero if not gcc */
333 struct type
*ftype
= check_typedef (value_type (function
));
335 struct regcache
*caller_regcache
;
336 struct cleanup
*caller_regcache_cleanup
;
337 struct frame_id dummy_id
;
339 if (TYPE_CODE (ftype
) == TYPE_CODE_PTR
)
340 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
342 if (!target_has_execution
)
345 if (!gdbarch_push_dummy_call_p (current_gdbarch
))
346 error (_("This target does not support function calls"));
348 /* Create a cleanup chain that contains the retbuf (buffer
349 containing the register values). This chain is create BEFORE the
350 inf_status chain so that the inferior status can cleaned up
351 (restored or discarded) without having the retbuf freed. */
352 retbuf
= regcache_xmalloc (current_gdbarch
);
353 retbuf_cleanup
= make_cleanup_regcache_xfree (retbuf
);
355 /* A cleanup for the inferior status. Create this AFTER the retbuf
356 so that this can be discarded or applied without interfering with
358 inf_status
= save_inferior_status (1);
359 inf_status_cleanup
= make_cleanup_restore_inferior_status (inf_status
);
361 /* Save the caller's registers so that they can be restored once the
362 callee returns. To allow nested calls the registers are (further
363 down) pushed onto a dummy frame stack. Include a cleanup (which
364 is tossed once the regcache has been pushed). */
365 caller_regcache
= frame_save_as_regcache (get_current_frame ());
366 caller_regcache_cleanup
= make_cleanup_regcache_xfree (caller_regcache
);
368 /* Ensure that the initial SP is correctly aligned. */
370 CORE_ADDR old_sp
= read_sp ();
371 if (gdbarch_frame_align_p (current_gdbarch
))
373 sp
= gdbarch_frame_align (current_gdbarch
, old_sp
);
374 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
375 ABIs, a function can use memory beyond the inner most stack
376 address. AMD64 called that region the "red zone". Skip at
377 least the "red zone" size before allocating any space on
379 if (INNER_THAN (1, 2))
380 sp
-= gdbarch_frame_red_zone_size (current_gdbarch
);
382 sp
+= gdbarch_frame_red_zone_size (current_gdbarch
);
384 gdb_assert (sp
== gdbarch_frame_align (current_gdbarch
, sp
));
385 /* NOTE: cagney/2002-09-18:
387 On a RISC architecture, a void parameterless generic dummy
388 frame (i.e., no parameters, no result) typically does not
389 need to push anything the stack and hence can leave SP and
390 FP. Similarly, a frameless (possibly leaf) function does
391 not push anything on the stack and, hence, that too can
392 leave FP and SP unchanged. As a consequence, a sequence of
393 void parameterless generic dummy frame calls to frameless
394 functions will create a sequence of effectively identical
395 frames (SP, FP and TOS and PC the same). This, not
396 suprisingly, results in what appears to be a stack in an
397 infinite loop --- when GDB tries to find a generic dummy
398 frame on the internal dummy frame stack, it will always
401 To avoid this problem, the code below always grows the
402 stack. That way, two dummy frames can never be identical.
403 It does burn a few bytes of stack but that is a small price
407 if (INNER_THAN (1, 2))
408 /* Stack grows down. */
409 sp
= gdbarch_frame_align (current_gdbarch
, old_sp
- 1);
411 /* Stack grows up. */
412 sp
= gdbarch_frame_align (current_gdbarch
, old_sp
+ 1);
414 gdb_assert ((INNER_THAN (1, 2) && sp
<= old_sp
)
415 || (INNER_THAN (2, 1) && sp
>= old_sp
));
418 /* FIXME: cagney/2002-09-18: Hey, you loose!
420 Who knows how badly aligned the SP is!
422 If the generic dummy frame ends up empty (because nothing is
423 pushed) GDB won't be able to correctly perform back traces.
424 If a target is having trouble with backtraces, first thing to
425 do is add FRAME_ALIGN() to the architecture vector. If that
426 fails, try unwind_dummy_id().
428 If the ABI specifies a "Red Zone" (see the doco) the code
429 below will quietly trash it. */
433 funaddr
= find_function_addr (function
, &values_type
);
434 CHECK_TYPEDEF (values_type
);
437 struct block
*b
= block_for_pc (funaddr
);
438 /* If compiled without -g, assume GCC 2. */
439 using_gcc
= (b
== NULL
? 2 : BLOCK_GCC_COMPILED (b
));
442 /* Are we returning a value using a structure return or a normal
445 struct_return
= using_struct_return (values_type
, using_gcc
);
447 /* Determine the location of the breakpoint (and possibly other
448 stuff) that the called function will return to. The SPARC, for a
449 function returning a structure or union, needs to make space for
450 not just the breakpoint but also an extra word containing the
451 size (?) of the structure being passed. */
453 /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
454 is no need to write that out. */
456 switch (CALL_DUMMY_LOCATION
)
459 /* "dummy_addr" is here just to keep old targets happy. New
460 targets return that same information via "sp" and "bp_addr". */
461 if (INNER_THAN (1, 2))
463 sp
= push_dummy_code (current_gdbarch
, sp
, funaddr
,
464 using_gcc
, args
, nargs
, values_type
,
471 sp
= push_dummy_code (current_gdbarch
, sp
, funaddr
,
472 using_gcc
, args
, nargs
, values_type
,
478 dummy_addr
= entry_point_address ();
479 /* Make certain that the address points at real code, and not a
480 function descriptor. */
481 dummy_addr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
484 /* A call dummy always consists of just a single breakpoint, so
485 it's address is the same as the address of the dummy. */
486 bp_addr
= dummy_addr
;
489 /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
490 address is the location where the breakpoint should be
491 placed. Once all targets are using the overhauled frame code
492 this can be deleted - ON_STACK is a better option. */
494 struct minimal_symbol
*sym
;
496 sym
= lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL
, NULL
);
499 dummy_addr
= SYMBOL_VALUE_ADDRESS (sym
);
501 dummy_addr
= entry_point_address ();
502 /* Make certain that the address points at real code, and not
503 a function descriptor. */
504 dummy_addr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
507 /* A call dummy always consists of just a single breakpoint,
508 so it's address is the same as the address of the dummy. */
509 bp_addr
= dummy_addr
;
513 internal_error (__FILE__
, __LINE__
, _("bad switch"));
516 if (nargs
< TYPE_NFIELDS (ftype
))
517 error (_("too few arguments in function call"));
521 for (i
= nargs
- 1; i
>= 0; i
--)
524 struct type
*param_type
;
526 /* FIXME drow/2002-05-31: Should just always mark methods as
527 prototyped. Can we respect TYPE_VARARGS? Probably not. */
528 if (TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
530 else if (i
< TYPE_NFIELDS (ftype
))
531 prototyped
= TYPE_PROTOTYPED (ftype
);
535 if (i
< TYPE_NFIELDS (ftype
))
536 param_type
= TYPE_FIELD_TYPE (ftype
, i
);
540 args
[i
] = value_arg_coerce (args
[i
], param_type
, prototyped
);
542 /* elz: this code is to handle the case in which the function
543 to be called has a pointer to function as parameter and the
544 corresponding actual argument is the address of a function
545 and not a pointer to function variable. In aCC compiled
546 code, the calls through pointers to functions (in the body
547 of the function called by hand) are made via
548 $$dyncall_external which requires some registers setting,
549 this is taken care of if we call via a function pointer
550 variable, but not via a function address. In cc this is
555 if (param_type
!= NULL
&& TYPE_CODE (ftype
) != TYPE_CODE_METHOD
)
557 /* if this parameter is a pointer to function. */
558 if (TYPE_CODE (param_type
) == TYPE_CODE_PTR
)
559 if (TYPE_CODE (TYPE_TARGET_TYPE (param_type
)) == TYPE_CODE_FUNC
)
560 /* elz: FIXME here should go the test about the
561 compiler used to compile the target. We want to
562 issue the error message only if the compiler
563 used was HP's aCC. If we used HP's cc, then
564 there is no problem and no need to return at
566 /* Go see if the actual parameter is a variable of
567 type pointer to function or just a function. */
568 if (VALUE_LVAL (args
[i
]) == not_lval
)
571 /* NOTE: cagney/2005-01-02: THIS IS BOGUS. */
572 if (find_pc_partial_function ((CORE_ADDR
) value_contents (args
[i
])[0], &arg_name
, NULL
, NULL
))
574 You cannot use function <%s> as argument. \n\
575 You must use a pointer to function type variable. Command ignored."), arg_name
);
582 if (DEPRECATED_REG_STRUCT_HAS_ADDR_P ())
585 /* This is a machine like the sparc, where we may need to pass a
586 pointer to the structure, not the structure itself. */
587 for (i
= nargs
- 1; i
>= 0; i
--)
589 struct type
*arg_type
= check_typedef (value_type (args
[i
]));
590 if ((TYPE_CODE (arg_type
) == TYPE_CODE_STRUCT
591 || TYPE_CODE (arg_type
) == TYPE_CODE_UNION
592 || TYPE_CODE (arg_type
) == TYPE_CODE_ARRAY
593 || TYPE_CODE (arg_type
) == TYPE_CODE_STRING
594 || TYPE_CODE (arg_type
) == TYPE_CODE_BITSTRING
595 || TYPE_CODE (arg_type
) == TYPE_CODE_SET
596 || (TYPE_CODE (arg_type
) == TYPE_CODE_FLT
597 && TYPE_LENGTH (arg_type
) > 8)
599 && DEPRECATED_REG_STRUCT_HAS_ADDR (using_gcc
, arg_type
))
602 int len
; /* = TYPE_LENGTH (arg_type); */
604 arg_type
= check_typedef (value_enclosing_type (args
[i
]));
605 len
= TYPE_LENGTH (arg_type
);
608 if (INNER_THAN (1, 2))
610 /* stack grows downward */
612 /* ... so the address of the thing we push is the
613 stack pointer after we push it. */
618 /* The stack grows up, so the address of the thing
619 we push is the stack pointer before we push it. */
623 /* Push the structure. */
624 write_memory (addr
, value_contents_all (args
[i
]), len
);
625 /* The value we're going to pass is the address of the
626 thing we just pushed. */
627 /*args[i] = value_from_longest (lookup_pointer_type (values_type),
629 args
[i
] = value_from_pointer (lookup_pointer_type (arg_type
),
636 /* Reserve space for the return structure to be written on the
637 stack, if necessary. Make certain that the value is correctly
642 int len
= TYPE_LENGTH (values_type
);
643 if (INNER_THAN (1, 2))
645 /* Stack grows downward. Align STRUCT_ADDR and SP after
646 making space for the return value. */
648 if (gdbarch_frame_align_p (current_gdbarch
))
649 sp
= gdbarch_frame_align (current_gdbarch
, sp
);
654 /* Stack grows upward. Align the frame, allocate space, and
655 then again, re-align the frame??? */
656 if (gdbarch_frame_align_p (current_gdbarch
))
657 sp
= gdbarch_frame_align (current_gdbarch
, sp
);
660 if (gdbarch_frame_align_p (current_gdbarch
))
661 sp
= gdbarch_frame_align (current_gdbarch
, sp
);
665 /* Create the dummy stack frame. Pass in the call dummy address as,
666 presumably, the ABI code knows where, in the call dummy, the
667 return address should be pointed. */
668 sp
= gdbarch_push_dummy_call (current_gdbarch
, function
, current_regcache
,
669 bp_addr
, nargs
, args
, sp
, struct_return
,
672 /* Set up a frame ID for the dummy frame so we can pass it to
673 set_momentary_breakpoint. We need to give the breakpoint a frame
674 ID so that the breakpoint code can correctly re-identify the
676 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
677 saved as the dummy-frame TOS, and used by unwind_dummy_id to form
678 the frame ID's stack address. */
679 dummy_id
= frame_id_build (sp
, bp_addr
);
681 /* Create a momentary breakpoint at the return address of the
682 inferior. That way it breaks when it returns. */
685 struct breakpoint
*bpt
;
686 struct symtab_and_line sal
;
687 init_sal (&sal
); /* initialize to zeroes */
689 sal
.section
= find_pc_overlay (sal
.pc
);
690 /* Sanity. The exact same SP value is returned by
691 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
692 unwind_dummy_id to form the frame ID's stack address. */
693 bpt
= set_momentary_breakpoint (sal
, dummy_id
, bp_call_dummy
);
694 bpt
->disposition
= disp_del
;
697 /* Everything's ready, push all the info needed to restore the
698 caller (and identify the dummy-frame) onto the dummy-frame
700 dummy_frame_push (caller_regcache
, &dummy_id
);
701 discard_cleanups (caller_regcache_cleanup
);
703 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
704 If you're looking to implement asynchronous dummy-frames, then
705 just below is the place to chop this function in two.. */
707 /* Now proceed, having reached the desired place. */
708 clear_proceed_status ();
710 /* Execute a "stack dummy", a piece of code stored in the stack by
711 the debugger to be executed in the inferior.
713 The dummy's frame is automatically popped whenever that break is
714 hit. If that is the first time the program stops,
715 call_function_by_hand returns to its caller with that frame
716 already gone and sets RC to 0.
718 Otherwise, set RC to a non-zero value. If the called function
719 receives a random signal, we do not allow the user to continue
720 executing it as this may not work. The dummy frame is poped and
721 we return 1. If we hit a breakpoint, we leave the frame in place
722 and return 2 (the frame will eventually be popped when we do hit
723 the dummy end breakpoint). */
726 struct cleanup
*old_cleanups
= make_cleanup (null_cleanup
, 0);
729 /* If all error()s out of proceed ended up calling normal_stop
730 (and perhaps they should; it already does in the special case
731 of error out of resume()), then we wouldn't need this. */
732 make_cleanup (breakpoint_auto_delete_contents
, &stop_bpstat
);
734 disable_watchpoints_before_interactive_call_start ();
735 proceed_to_finish
= 1; /* We want stop_registers, please... */
737 if (target_can_async_p ())
738 saved_async
= target_async_mask (0);
740 proceed (real_pc
, TARGET_SIGNAL_0
, 0);
743 target_async_mask (saved_async
);
745 enable_watchpoints_after_interactive_call_stop ();
747 discard_cleanups (old_cleanups
);
750 if (stopped_by_random_signal
|| !stop_stack_dummy
)
752 /* Find the name of the function we're about to complain about. */
753 const char *name
= NULL
;
755 struct symbol
*symbol
= find_pc_function (funaddr
);
757 name
= SYMBOL_PRINT_NAME (symbol
);
760 /* Try the minimal symbols. */
761 struct minimal_symbol
*msymbol
= lookup_minimal_symbol_by_pc (funaddr
);
763 name
= SYMBOL_PRINT_NAME (msymbol
);
767 /* Can't use a cleanup here. It is discarded, instead use
769 char *tmp
= xstrprintf ("at %s", hex_string (funaddr
));
770 char *a
= alloca (strlen (tmp
) + 1);
776 if (stopped_by_random_signal
)
778 /* We stopped inside the FUNCTION because of a random
779 signal. Further execution of the FUNCTION is not
782 if (unwind_on_signal_p
)
784 /* The user wants the context restored. */
786 /* We must get back to the frame we were before the
788 frame_pop (get_current_frame ());
790 /* FIXME: Insert a bunch of wrap_here; name can be very
791 long if it's a C++ name with arguments and stuff. */
793 The program being debugged was signaled while in a function called from GDB.\n\
794 GDB has restored the context to what it was before the call.\n\
795 To change this behavior use \"set unwindonsignal off\"\n\
796 Evaluation of the expression containing the function (%s) will be abandoned."),
801 /* The user wants to stay in the frame where we stopped
803 /* If we restored the inferior status (via the cleanup),
804 we would print a spurious error message (Unable to
805 restore previously selected frame), would write the
806 registers from the inf_status (which is wrong), and
807 would do other wrong things. */
808 discard_cleanups (inf_status_cleanup
);
809 discard_inferior_status (inf_status
);
810 /* FIXME: Insert a bunch of wrap_here; name can be very
811 long if it's a C++ name with arguments and stuff. */
813 The program being debugged was signaled while in a function called from GDB.\n\
814 GDB remains in the frame where the signal was received.\n\
815 To change this behavior use \"set unwindonsignal on\"\n\
816 Evaluation of the expression containing the function (%s) will be abandoned."),
821 if (!stop_stack_dummy
)
823 /* We hit a breakpoint inside the FUNCTION. */
824 /* If we restored the inferior status (via the cleanup), we
825 would print a spurious error message (Unable to restore
826 previously selected frame), would write the registers
827 from the inf_status (which is wrong), and would do other
829 discard_cleanups (inf_status_cleanup
);
830 discard_inferior_status (inf_status
);
831 /* The following error message used to say "The expression
832 which contained the function call has been discarded."
833 It is a hard concept to explain in a few words. Ideally,
834 GDB would be able to resume evaluation of the expression
835 when the function finally is done executing. Perhaps
836 someday this will be implemented (it would not be easy). */
837 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
838 a C++ name with arguments and stuff. */
840 The program being debugged stopped while in a function called from GDB.\n\
841 When the function (%s) is done executing, GDB will silently\n\
842 stop (instead of continuing to evaluate the expression containing\n\
843 the function call)."), name
);
846 /* The above code errors out, so ... */
847 internal_error (__FILE__
, __LINE__
, _("... should not be here"));
850 /* If we get here the called FUNCTION run to completion. */
852 /* On normal return, the stack dummy has been popped already. */
853 regcache_cpy_no_passthrough (retbuf
, stop_registers
);
855 /* Restore the inferior status, via its cleanup. At this stage,
856 leave the RETBUF alone. */
857 do_cleanups (inf_status_cleanup
);
859 /* Figure out the value returned by the function. */
861 struct value
*retval
= NULL
;
863 if (TYPE_CODE (values_type
) == TYPE_CODE_VOID
)
865 /* If the function returns void, don't bother fetching the
867 retval
= allocate_value (values_type
);
871 struct gdbarch
*arch
= current_gdbarch
;
873 switch (gdbarch_return_value (arch
, values_type
, NULL
, NULL
, NULL
))
875 case RETURN_VALUE_REGISTER_CONVENTION
:
876 case RETURN_VALUE_ABI_RETURNS_ADDRESS
:
877 case RETURN_VALUE_ABI_PRESERVES_ADDRESS
:
878 retval
= allocate_value (values_type
);
879 gdbarch_return_value (current_gdbarch
, values_type
, retbuf
,
880 value_contents_raw (retval
), NULL
);
882 case RETURN_VALUE_STRUCT_CONVENTION
:
883 retval
= value_at (values_type
, struct_addr
);
888 do_cleanups (retbuf_cleanup
);
896 /* Provide a prototype to silence -Wmissing-prototypes. */
897 void _initialize_infcall (void);
900 _initialize_infcall (void)
902 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure
,
903 &coerce_float_to_double_p
, _("\
904 Set coercion of floats to doubles when calling functions."), _("\
905 Show coercion of floats to doubles when calling functions"), _("\
906 Variables of type float should generally be converted to doubles before\n\
907 calling an unprototyped function, and left alone when calling a prototyped\n\
908 function. However, some older debug info formats do not provide enough\n\
909 information to determine that a function is prototyped. If this flag is\n\
910 set, GDB will perform the conversion for a function it considers\n\
912 The default is to perform the conversion.\n"),
914 show_coerce_float_to_double_p
,
915 &setlist
, &showlist
);
917 add_setshow_boolean_cmd ("unwindonsignal", no_class
,
918 &unwind_on_signal_p
, _("\
919 Set unwinding of stack if a signal is received while in a call dummy."), _("\
920 Show unwinding of stack if a signal is received while in a call dummy."), _("\
921 The unwindonsignal lets the user determine what gdb should do if a signal\n\
922 is received while in a function called from gdb (call dummy). If set, gdb\n\
923 unwinds the stack and restore the context to what as it was before the call.\n\
924 The default is to stop in the frame where the signal was received."),
926 show_unwind_on_signal_p
,
927 &setlist
, &showlist
);