1 /* Perform an inferior function call, for GDB, the GNU debugger.
3 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
5 2008 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 3 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, see <http://www.gnu.org/licenses/>. */
23 #include "breakpoint.h"
27 #include "gdb_assert.h"
34 #include "gdb_string.h"
36 #include "dummy-frame.h"
38 #include "gdbthread.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 or Ada 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.
100 SP is the stack pointer were additional data can be pushed (updating
101 its value as needed). */
103 static struct value
*
104 value_arg_coerce (struct gdbarch
*gdbarch
, struct value
*arg
,
105 struct type
*param_type
, int is_prototyped
, CORE_ADDR
*sp
)
107 const struct builtin_type
*builtin
= builtin_type (gdbarch
);
108 struct type
*arg_type
= check_typedef (value_type (arg
));
110 = param_type
? check_typedef (param_type
) : arg_type
;
112 /* Perform any Ada-specific coercion first. */
113 if (current_language
->la_language
== language_ada
)
114 arg
= ada_convert_actual (arg
, type
, sp
);
116 /* Force the value to the target if we will need its address. At
117 this point, we could allocate arguments on the stack instead of
118 calling malloc if we knew that their addresses would not be
119 saved by the called function. */
120 arg
= value_coerce_to_target (arg
);
122 switch (TYPE_CODE (type
))
126 struct value
*new_value
;
128 if (TYPE_CODE (arg_type
) == TYPE_CODE_REF
)
129 return value_cast_pointers (type
, arg
);
131 /* Cast the value to the reference's target type, and then
132 convert it back to a reference. This will issue an error
133 if the value was not previously in memory - in some cases
134 we should clearly be allowing this, but how? */
135 new_value
= value_cast (TYPE_TARGET_TYPE (type
), arg
);
136 new_value
= value_ref (new_value
);
143 /* If we don't have a prototype, coerce to integer type if necessary. */
146 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin
->builtin_int
))
147 type
= builtin
->builtin_int
;
149 /* Currently all target ABIs require at least the width of an integer
150 type for an argument. We may have to conditionalize the following
151 type coercion for future targets. */
152 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin
->builtin_int
))
153 type
= builtin
->builtin_int
;
156 if (!is_prototyped
&& coerce_float_to_double_p
)
158 if (TYPE_LENGTH (type
) < TYPE_LENGTH (builtin
->builtin_double
))
159 type
= builtin
->builtin_double
;
160 else if (TYPE_LENGTH (type
) > TYPE_LENGTH (builtin
->builtin_double
))
161 type
= builtin
->builtin_long_double
;
165 type
= lookup_pointer_type (type
);
167 case TYPE_CODE_ARRAY
:
168 /* Arrays are coerced to pointers to their first element, unless
169 they are vectors, in which case we want to leave them alone,
170 because they are passed by value. */
171 if (current_language
->c_style_arrays
)
172 if (!TYPE_VECTOR (type
))
173 type
= lookup_pointer_type (TYPE_TARGET_TYPE (type
));
175 case TYPE_CODE_UNDEF
:
177 case TYPE_CODE_STRUCT
:
178 case TYPE_CODE_UNION
:
181 case TYPE_CODE_RANGE
:
182 case TYPE_CODE_STRING
:
183 case TYPE_CODE_BITSTRING
:
184 case TYPE_CODE_ERROR
:
185 case TYPE_CODE_MEMBERPTR
:
186 case TYPE_CODE_METHODPTR
:
187 case TYPE_CODE_METHOD
:
188 case TYPE_CODE_COMPLEX
:
193 return value_cast (type
, arg
);
196 /* Determine a function's address and its return type from its value.
197 Calls error() if the function is not valid for calling. */
200 find_function_addr (struct value
*function
, struct type
**retval_type
)
202 struct type
*ftype
= check_typedef (value_type (function
));
203 enum type_code code
= TYPE_CODE (ftype
);
204 struct type
*value_type
= NULL
;
207 /* If it's a member function, just look at the function
210 /* Determine address to call. */
211 if (code
== TYPE_CODE_FUNC
|| code
== TYPE_CODE_METHOD
)
213 funaddr
= VALUE_ADDRESS (function
);
214 value_type
= TYPE_TARGET_TYPE (ftype
);
216 else if (code
== TYPE_CODE_PTR
)
218 funaddr
= value_as_address (function
);
219 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
220 if (TYPE_CODE (ftype
) == TYPE_CODE_FUNC
221 || TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
223 funaddr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
226 value_type
= TYPE_TARGET_TYPE (ftype
);
229 else if (code
== TYPE_CODE_INT
)
231 /* Handle the case of functions lacking debugging info.
232 Their values are characters since their addresses are char */
233 if (TYPE_LENGTH (ftype
) == 1)
234 funaddr
= value_as_address (value_addr (function
));
237 /* Handle function descriptors lacking debug info. */
238 int found_descriptor
= 0;
239 if (VALUE_LVAL (function
) == lval_memory
)
242 funaddr
= value_as_address (value_addr (function
));
244 funaddr
= gdbarch_convert_from_func_ptr_addr (current_gdbarch
,
247 if (funaddr
!= nfunaddr
)
248 found_descriptor
= 1;
250 if (!found_descriptor
)
251 /* Handle integer used as address of a function. */
252 funaddr
= (CORE_ADDR
) value_as_long (function
);
256 error (_("Invalid data type for function to be called."));
258 if (retval_type
!= NULL
)
259 *retval_type
= value_type
;
260 return funaddr
+ gdbarch_deprecated_function_start_offset (current_gdbarch
);
263 /* Call breakpoint_auto_delete on the current contents of the bpstat
264 of the current thread. */
267 breakpoint_auto_delete_contents (void *arg
)
269 if (!ptid_equal (inferior_ptid
, null_ptid
))
270 breakpoint_auto_delete (inferior_thread ()->stop_bpstat
);
274 generic_push_dummy_code (struct gdbarch
*gdbarch
,
275 CORE_ADDR sp
, CORE_ADDR funaddr
,
276 struct value
**args
, int nargs
,
277 struct type
*value_type
,
278 CORE_ADDR
*real_pc
, CORE_ADDR
*bp_addr
,
279 struct regcache
*regcache
)
281 /* Something here to findout the size of a breakpoint and then
282 allocate space for it on the stack. */
284 /* This code assumes frame align. */
285 gdb_assert (gdbarch_frame_align_p (gdbarch
));
286 /* Force the stack's alignment. The intent is to ensure that the SP
287 is aligned to at least a breakpoint instruction's boundary. */
288 sp
= gdbarch_frame_align (gdbarch
, sp
);
289 /* Allocate space for, and then position the breakpoint on the
291 if (gdbarch_inner_than (gdbarch
, 1, 2))
294 gdbarch_breakpoint_from_pc (gdbarch
, &bppc
, &bplen
);
295 sp
= gdbarch_frame_align (gdbarch
, sp
- bplen
);
297 /* Should the breakpoint size/location be re-computed here? */
302 gdbarch_breakpoint_from_pc (gdbarch
, bp_addr
, &bplen
);
303 sp
= gdbarch_frame_align (gdbarch
, sp
+ bplen
);
305 /* Inferior resumes at the function entry point. */
306 (*real_pc
) = funaddr
;
310 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
311 function returns to. */
314 push_dummy_code (struct gdbarch
*gdbarch
,
315 CORE_ADDR sp
, CORE_ADDR funaddr
,
316 struct value
**args
, int nargs
,
317 struct type
*value_type
,
318 CORE_ADDR
*real_pc
, CORE_ADDR
*bp_addr
,
319 struct regcache
*regcache
)
321 if (gdbarch_push_dummy_code_p (gdbarch
))
322 return gdbarch_push_dummy_code (gdbarch
, sp
, funaddr
,
323 args
, nargs
, value_type
, real_pc
, bp_addr
,
326 return generic_push_dummy_code (gdbarch
, sp
, funaddr
,
327 args
, nargs
, value_type
, real_pc
, bp_addr
,
331 /* All this stuff with a dummy frame may seem unnecessarily complicated
332 (why not just save registers in GDB?). The purpose of pushing a dummy
333 frame which looks just like a real frame is so that if you call a
334 function and then hit a breakpoint (get a signal, etc), "backtrace"
335 will look right. Whether the backtrace needs to actually show the
336 stack at the time the inferior function was called is debatable, but
337 it certainly needs to not display garbage. So if you are contemplating
338 making dummy frames be different from normal frames, consider that. */
340 /* Perform a function call in the inferior.
341 ARGS is a vector of values of arguments (NARGS of them).
342 FUNCTION is a value, the function to be called.
343 Returns a value representing what the function returned.
344 May fail to return, if a breakpoint or signal is hit
345 during the execution of the function.
347 ARGS is modified to contain coerced values. */
350 call_function_by_hand (struct value
*function
, int nargs
, struct value
**args
)
353 CORE_ADDR dummy_addr
;
354 struct type
*values_type
, *target_values_type
;
355 unsigned char struct_return
= 0, lang_struct_return
= 0;
356 CORE_ADDR struct_addr
= 0;
357 struct regcache
*retbuf
;
358 struct cleanup
*retbuf_cleanup
;
359 struct inferior_status
*inf_status
;
360 struct cleanup
*inf_status_cleanup
;
363 struct type
*ftype
= check_typedef (value_type (function
));
365 struct regcache
*caller_regcache
;
366 struct cleanup
*caller_regcache_cleanup
;
367 struct frame_id dummy_id
;
368 struct cleanup
*args_cleanup
;
369 struct frame_info
*frame
;
370 struct gdbarch
*gdbarch
;
372 if (TYPE_CODE (ftype
) == TYPE_CODE_PTR
)
373 ftype
= check_typedef (TYPE_TARGET_TYPE (ftype
));
375 if (!target_has_execution
)
378 frame
= get_current_frame ();
379 gdbarch
= get_frame_arch (frame
);
381 if (!gdbarch_push_dummy_call_p (gdbarch
))
382 error (_("This target does not support function calls"));
384 /* Create a cleanup chain that contains the retbuf (buffer
385 containing the register values). This chain is create BEFORE the
386 inf_status chain so that the inferior status can cleaned up
387 (restored or discarded) without having the retbuf freed. */
388 retbuf
= regcache_xmalloc (gdbarch
);
389 retbuf_cleanup
= make_cleanup_regcache_xfree (retbuf
);
391 /* A cleanup for the inferior status. Create this AFTER the retbuf
392 so that this can be discarded or applied without interfering with
394 inf_status
= save_inferior_status (1);
395 inf_status_cleanup
= make_cleanup_restore_inferior_status (inf_status
);
397 /* Save the caller's registers so that they can be restored once the
398 callee returns. To allow nested calls the registers are (further
399 down) pushed onto a dummy frame stack. Include a cleanup (which
400 is tossed once the regcache has been pushed). */
401 caller_regcache
= frame_save_as_regcache (frame
);
402 caller_regcache_cleanup
= make_cleanup_regcache_xfree (caller_regcache
);
404 /* Ensure that the initial SP is correctly aligned. */
406 CORE_ADDR old_sp
= get_frame_sp (frame
);
407 if (gdbarch_frame_align_p (gdbarch
))
409 sp
= gdbarch_frame_align (gdbarch
, old_sp
);
410 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
411 ABIs, a function can use memory beyond the inner most stack
412 address. AMD64 called that region the "red zone". Skip at
413 least the "red zone" size before allocating any space on
415 if (gdbarch_inner_than (gdbarch
, 1, 2))
416 sp
-= gdbarch_frame_red_zone_size (gdbarch
);
418 sp
+= gdbarch_frame_red_zone_size (gdbarch
);
420 gdb_assert (sp
== gdbarch_frame_align (gdbarch
, sp
));
421 /* NOTE: cagney/2002-09-18:
423 On a RISC architecture, a void parameterless generic dummy
424 frame (i.e., no parameters, no result) typically does not
425 need to push anything the stack and hence can leave SP and
426 FP. Similarly, a frameless (possibly leaf) function does
427 not push anything on the stack and, hence, that too can
428 leave FP and SP unchanged. As a consequence, a sequence of
429 void parameterless generic dummy frame calls to frameless
430 functions will create a sequence of effectively identical
431 frames (SP, FP and TOS and PC the same). This, not
432 suprisingly, results in what appears to be a stack in an
433 infinite loop --- when GDB tries to find a generic dummy
434 frame on the internal dummy frame stack, it will always
437 To avoid this problem, the code below always grows the
438 stack. That way, two dummy frames can never be identical.
439 It does burn a few bytes of stack but that is a small price
443 if (gdbarch_inner_than (gdbarch
, 1, 2))
444 /* Stack grows down. */
445 sp
= gdbarch_frame_align (gdbarch
, old_sp
- 1);
447 /* Stack grows up. */
448 sp
= gdbarch_frame_align (gdbarch
, old_sp
+ 1);
450 gdb_assert ((gdbarch_inner_than (gdbarch
, 1, 2)
452 || (gdbarch_inner_than (gdbarch
, 2, 1)
456 /* FIXME: cagney/2002-09-18: Hey, you loose!
458 Who knows how badly aligned the SP is!
460 If the generic dummy frame ends up empty (because nothing is
461 pushed) GDB won't be able to correctly perform back traces.
462 If a target is having trouble with backtraces, first thing to
463 do is add FRAME_ALIGN() to the architecture vector. If that
464 fails, try dummy_id().
466 If the ABI specifies a "Red Zone" (see the doco) the code
467 below will quietly trash it. */
471 funaddr
= find_function_addr (function
, &values_type
);
473 values_type
= builtin_type (gdbarch
)->builtin_int
;
475 CHECK_TYPEDEF (values_type
);
477 /* Are we returning a value using a structure return (passing a
478 hidden argument pointing to storage) or a normal value return?
479 There are two cases: language-mandated structure return and
480 target ABI structure return. The variable STRUCT_RETURN only
481 describes the latter. The language version is handled by passing
482 the return location as the first parameter to the function,
483 even preceding "this". This is different from the target
484 ABI version, which is target-specific; for instance, on ia64
485 the first argument is passed in out0 but the hidden structure
486 return pointer would normally be passed in r8. */
488 if (language_pass_by_reference (values_type
))
490 lang_struct_return
= 1;
492 /* Tell the target specific argument pushing routine not to
494 target_values_type
= builtin_type_void
;
498 struct_return
= using_struct_return (value_type (function
), values_type
);
499 target_values_type
= values_type
;
502 /* Determine the location of the breakpoint (and possibly other
503 stuff) that the called function will return to. The SPARC, for a
504 function returning a structure or union, needs to make space for
505 not just the breakpoint but also an extra word containing the
506 size (?) of the structure being passed. */
508 /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
509 is no need to write that out. */
511 switch (gdbarch_call_dummy_location (gdbarch
))
514 /* "dummy_addr" is here just to keep old targets happy. New
515 targets return that same information via "sp" and "bp_addr". */
516 if (gdbarch_inner_than (gdbarch
, 1, 2))
518 sp
= push_dummy_code (gdbarch
, sp
, funaddr
,
519 args
, nargs
, target_values_type
,
520 &real_pc
, &bp_addr
, get_current_regcache ());
526 sp
= push_dummy_code (gdbarch
, sp
, funaddr
,
527 args
, nargs
, target_values_type
,
528 &real_pc
, &bp_addr
, get_current_regcache ());
533 dummy_addr
= entry_point_address ();
534 /* Make certain that the address points at real code, and not a
535 function descriptor. */
536 dummy_addr
= gdbarch_convert_from_func_ptr_addr (gdbarch
,
539 /* A call dummy always consists of just a single breakpoint, so
540 it's address is the same as the address of the dummy. */
541 bp_addr
= dummy_addr
;
544 /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
545 address is the location where the breakpoint should be
546 placed. Once all targets are using the overhauled frame code
547 this can be deleted - ON_STACK is a better option. */
549 struct minimal_symbol
*sym
;
551 sym
= lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL
, NULL
);
554 dummy_addr
= SYMBOL_VALUE_ADDRESS (sym
);
556 dummy_addr
= entry_point_address ();
557 /* Make certain that the address points at real code, and not
558 a function descriptor. */
559 dummy_addr
= gdbarch_convert_from_func_ptr_addr (gdbarch
,
562 /* A call dummy always consists of just a single breakpoint,
563 so it's address is the same as the address of the dummy. */
564 bp_addr
= dummy_addr
;
568 internal_error (__FILE__
, __LINE__
, _("bad switch"));
571 if (nargs
< TYPE_NFIELDS (ftype
))
572 error (_("too few arguments in function call"));
576 for (i
= nargs
- 1; i
>= 0; i
--)
579 struct type
*param_type
;
581 /* FIXME drow/2002-05-31: Should just always mark methods as
582 prototyped. Can we respect TYPE_VARARGS? Probably not. */
583 if (TYPE_CODE (ftype
) == TYPE_CODE_METHOD
)
585 else if (i
< TYPE_NFIELDS (ftype
))
586 prototyped
= TYPE_PROTOTYPED (ftype
);
590 if (i
< TYPE_NFIELDS (ftype
))
591 param_type
= TYPE_FIELD_TYPE (ftype
, i
);
595 args
[i
] = value_arg_coerce (gdbarch
, args
[i
],
596 param_type
, prototyped
, &sp
);
598 if (param_type
!= NULL
&& language_pass_by_reference (param_type
))
599 args
[i
] = value_addr (args
[i
]);
603 /* Reserve space for the return structure to be written on the
604 stack, if necessary. Make certain that the value is correctly
607 if (struct_return
|| lang_struct_return
)
609 int len
= TYPE_LENGTH (values_type
);
610 if (gdbarch_inner_than (gdbarch
, 1, 2))
612 /* Stack grows downward. Align STRUCT_ADDR and SP after
613 making space for the return value. */
615 if (gdbarch_frame_align_p (gdbarch
))
616 sp
= gdbarch_frame_align (gdbarch
, sp
);
621 /* Stack grows upward. Align the frame, allocate space, and
622 then again, re-align the frame??? */
623 if (gdbarch_frame_align_p (gdbarch
))
624 sp
= gdbarch_frame_align (gdbarch
, sp
);
627 if (gdbarch_frame_align_p (gdbarch
))
628 sp
= gdbarch_frame_align (gdbarch
, sp
);
632 if (lang_struct_return
)
634 struct value
**new_args
;
636 /* Add the new argument to the front of the argument list. */
637 new_args
= xmalloc (sizeof (struct value
*) * (nargs
+ 1));
638 new_args
[0] = value_from_pointer (lookup_pointer_type (values_type
),
640 memcpy (&new_args
[1], &args
[0], sizeof (struct value
*) * nargs
);
643 args_cleanup
= make_cleanup (xfree
, args
);
646 args_cleanup
= make_cleanup (null_cleanup
, NULL
);
648 /* Create the dummy stack frame. Pass in the call dummy address as,
649 presumably, the ABI code knows where, in the call dummy, the
650 return address should be pointed. */
651 sp
= gdbarch_push_dummy_call (gdbarch
, function
, get_current_regcache (),
652 bp_addr
, nargs
, args
,
653 sp
, struct_return
, struct_addr
);
655 do_cleanups (args_cleanup
);
657 /* Set up a frame ID for the dummy frame so we can pass it to
658 set_momentary_breakpoint. We need to give the breakpoint a frame
659 ID so that the breakpoint code can correctly re-identify the
661 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
662 saved as the dummy-frame TOS, and used by dummy_id to form
663 the frame ID's stack address. */
664 dummy_id
= frame_id_build (sp
, bp_addr
);
666 /* Create a momentary breakpoint at the return address of the
667 inferior. That way it breaks when it returns. */
670 struct breakpoint
*bpt
;
671 struct symtab_and_line sal
;
672 init_sal (&sal
); /* initialize to zeroes */
674 sal
.section
= find_pc_overlay (sal
.pc
);
675 /* Sanity. The exact same SP value is returned by
676 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
677 dummy_id to form the frame ID's stack address. */
678 bpt
= set_momentary_breakpoint (sal
, dummy_id
, bp_call_dummy
);
679 bpt
->disposition
= disp_del
;
682 /* Everything's ready, push all the info needed to restore the
683 caller (and identify the dummy-frame) onto the dummy-frame
685 dummy_frame_push (caller_regcache
, &dummy_id
);
686 discard_cleanups (caller_regcache_cleanup
);
688 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
689 If you're looking to implement asynchronous dummy-frames, then
690 just below is the place to chop this function in two.. */
692 /* Now proceed, having reached the desired place. */
693 clear_proceed_status ();
695 /* Execute a "stack dummy", a piece of code stored in the stack by
696 the debugger to be executed in the inferior.
698 The dummy's frame is automatically popped whenever that break is
699 hit. If that is the first time the program stops,
700 call_function_by_hand returns to its caller with that frame
701 already gone and sets RC to 0.
703 Otherwise, set RC to a non-zero value. If the called function
704 receives a random signal, we do not allow the user to continue
705 executing it as this may not work. The dummy frame is poped and
706 we return 1. If we hit a breakpoint, we leave the frame in place
707 and return 2 (the frame will eventually be popped when we do hit
708 the dummy end breakpoint). */
711 struct cleanup
*old_cleanups
= make_cleanup (null_cleanup
, 0);
712 struct cleanup
*old_cleanups2
;
714 struct thread_info
*tp
= inferior_thread ();
716 /* If all error()s out of proceed ended up calling normal_stop
717 (and perhaps they should; it already does in the special case
718 of error out of resume()), then we wouldn't need this. */
719 make_cleanup (breakpoint_auto_delete_contents
, NULL
);
721 disable_watchpoints_before_interactive_call_start ();
722 tp
->proceed_to_finish
= 1; /* We want stop_registers, please... */
724 if (target_can_async_p ())
725 saved_async
= target_async_mask (0);
727 old_cleanups2
= make_cleanup_restore_integer (&suppress_resume_observer
);
728 suppress_resume_observer
= 1;
729 make_cleanup_restore_integer (&suppress_stop_observer
);
730 suppress_stop_observer
= 1;
731 proceed (real_pc
, TARGET_SIGNAL_0
, 0);
732 do_cleanups (old_cleanups2
);
735 target_async_mask (saved_async
);
737 enable_watchpoints_after_interactive_call_stop ();
739 discard_cleanups (old_cleanups
);
742 if (stopped_by_random_signal
|| !stop_stack_dummy
)
744 /* Find the name of the function we're about to complain about. */
745 const char *name
= NULL
;
747 struct symbol
*symbol
= find_pc_function (funaddr
);
749 name
= SYMBOL_PRINT_NAME (symbol
);
752 /* Try the minimal symbols. */
753 struct minimal_symbol
*msymbol
= lookup_minimal_symbol_by_pc (funaddr
);
755 name
= SYMBOL_PRINT_NAME (msymbol
);
759 /* Can't use a cleanup here. It is discarded, instead use
761 char *tmp
= xstrprintf ("at %s", hex_string (funaddr
));
762 char *a
= alloca (strlen (tmp
) + 1);
768 if (stopped_by_random_signal
)
770 /* We stopped inside the FUNCTION because of a random
771 signal. Further execution of the FUNCTION is not
774 if (unwind_on_signal_p
)
776 /* The user wants the context restored. */
778 /* We must get back to the frame we were before the
780 frame_pop (get_current_frame ());
782 /* FIXME: Insert a bunch of wrap_here; name can be very
783 long if it's a C++ name with arguments and stuff. */
785 The program being debugged was signaled while in a function called from GDB.\n\
786 GDB has restored the context to what it was before the call.\n\
787 To change this behavior use \"set unwindonsignal off\"\n\
788 Evaluation of the expression containing the function (%s) will be abandoned."),
793 /* The user wants to stay in the frame where we stopped
795 /* If we restored the inferior status (via the cleanup),
796 we would print a spurious error message (Unable to
797 restore previously selected frame), would write the
798 registers from the inf_status (which is wrong), and
799 would do other wrong things. */
800 discard_cleanups (inf_status_cleanup
);
801 discard_inferior_status (inf_status
);
802 /* FIXME: Insert a bunch of wrap_here; name can be very
803 long if it's a C++ name with arguments and stuff. */
805 The program being debugged was signaled while in a function called from GDB.\n\
806 GDB remains in the frame where the signal was received.\n\
807 To change this behavior use \"set unwindonsignal on\"\n\
808 Evaluation of the expression containing the function (%s) will be abandoned."),
813 if (!stop_stack_dummy
)
815 /* We hit a breakpoint inside the FUNCTION. */
816 /* If we restored the inferior status (via the cleanup), we
817 would print a spurious error message (Unable to restore
818 previously selected frame), would write the registers
819 from the inf_status (which is wrong), and would do other
821 discard_cleanups (inf_status_cleanup
);
822 discard_inferior_status (inf_status
);
823 /* The following error message used to say "The expression
824 which contained the function call has been discarded."
825 It is a hard concept to explain in a few words. Ideally,
826 GDB would be able to resume evaluation of the expression
827 when the function finally is done executing. Perhaps
828 someday this will be implemented (it would not be easy). */
829 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
830 a C++ name with arguments and stuff. */
832 The program being debugged stopped while in a function called from GDB.\n\
833 When the function (%s) is done executing, GDB will silently\n\
834 stop (instead of continuing to evaluate the expression containing\n\
835 the function call)."), name
);
838 /* The above code errors out, so ... */
839 internal_error (__FILE__
, __LINE__
, _("... should not be here"));
842 /* If we get here the called FUNCTION run to completion. */
844 /* On normal return, the stack dummy has been popped already. */
845 regcache_cpy_no_passthrough (retbuf
, stop_registers
);
847 /* Restore the inferior status, via its cleanup. At this stage,
848 leave the RETBUF alone. */
849 do_cleanups (inf_status_cleanup
);
851 /* Figure out the value returned by the function. */
853 struct value
*retval
= NULL
;
855 if (lang_struct_return
)
856 retval
= value_at (values_type
, struct_addr
);
857 else if (TYPE_CODE (target_values_type
) == TYPE_CODE_VOID
)
859 /* If the function returns void, don't bother fetching the
861 retval
= allocate_value (values_type
);
865 switch (gdbarch_return_value (gdbarch
, value_type (function
),
866 target_values_type
, NULL
, NULL
, NULL
))
868 case RETURN_VALUE_REGISTER_CONVENTION
:
869 case RETURN_VALUE_ABI_RETURNS_ADDRESS
:
870 case RETURN_VALUE_ABI_PRESERVES_ADDRESS
:
871 retval
= allocate_value (values_type
);
872 gdbarch_return_value (gdbarch
, value_type (function
), values_type
,
873 retbuf
, value_contents_raw (retval
), NULL
);
875 case RETURN_VALUE_STRUCT_CONVENTION
:
876 retval
= value_at (values_type
, struct_addr
);
881 do_cleanups (retbuf_cleanup
);
889 /* Provide a prototype to silence -Wmissing-prototypes. */
890 void _initialize_infcall (void);
893 _initialize_infcall (void)
895 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure
,
896 &coerce_float_to_double_p
, _("\
897 Set coercion of floats to doubles when calling functions."), _("\
898 Show coercion of floats to doubles when calling functions"), _("\
899 Variables of type float should generally be converted to doubles before\n\
900 calling an unprototyped function, and left alone when calling a prototyped\n\
901 function. However, some older debug info formats do not provide enough\n\
902 information to determine that a function is prototyped. If this flag is\n\
903 set, GDB will perform the conversion for a function it considers\n\
905 The default is to perform the conversion.\n"),
907 show_coerce_float_to_double_p
,
908 &setlist
, &showlist
);
910 add_setshow_boolean_cmd ("unwindonsignal", no_class
,
911 &unwind_on_signal_p
, _("\
912 Set unwinding of stack if a signal is received while in a call dummy."), _("\
913 Show unwinding of stack if a signal is received while in a call dummy."), _("\
914 The unwindonsignal lets the user determine what gdb should do if a signal\n\
915 is received while in a function called from gdb (call dummy). If set, gdb\n\
916 unwinds the stack and restore the context to what as it was before the call.\n\
917 The default is to stop in the frame where the signal was received."),
919 show_unwind_on_signal_p
,
920 &setlist
, &showlist
);