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, 2009 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);
273 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
274 function returns to. */
277 push_dummy_code (struct gdbarch *gdbarch,
278 CORE_ADDR sp, CORE_ADDR funaddr,
279 struct value **args, int nargs,
280 struct type *value_type,
281 CORE_ADDR *real_pc, CORE_ADDR *bp_addr,
282 struct regcache *regcache)
284 gdb_assert (gdbarch_push_dummy_code_p (gdbarch));
286 return gdbarch_push_dummy_code (gdbarch, sp, funaddr,
287 args, nargs, value_type, real_pc, bp_addr,
291 /* All this stuff with a dummy frame may seem unnecessarily complicated
292 (why not just save registers in GDB?). The purpose of pushing a dummy
293 frame which looks just like a real frame is so that if you call a
294 function and then hit a breakpoint (get a signal, etc), "backtrace"
295 will look right. Whether the backtrace needs to actually show the
296 stack at the time the inferior function was called is debatable, but
297 it certainly needs to not display garbage. So if you are contemplating
298 making dummy frames be different from normal frames, consider that. */
300 /* Perform a function call in the inferior.
301 ARGS is a vector of values of arguments (NARGS of them).
302 FUNCTION is a value, the function to be called.
303 Returns a value representing what the function returned.
304 May fail to return, if a breakpoint or signal is hit
305 during the execution of the function.
307 ARGS is modified to contain coerced values. */
310 call_function_by_hand (struct value *function, int nargs, struct value **args)
313 struct type *values_type, *target_values_type;
314 unsigned char struct_return = 0, lang_struct_return = 0;
315 CORE_ADDR struct_addr = 0;
316 struct regcache *retbuf;
317 struct cleanup *retbuf_cleanup;
318 struct inferior_status *inf_status;
319 struct cleanup *inf_status_cleanup;
322 struct type *ftype = check_typedef (value_type (function));
324 struct regcache *caller_regcache;
325 struct cleanup *caller_regcache_cleanup;
326 struct frame_id dummy_id;
327 struct cleanup *args_cleanup;
328 struct frame_info *frame;
329 struct gdbarch *gdbarch;
331 if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
332 ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
334 if (!target_has_execution)
337 frame = get_current_frame ();
338 gdbarch = get_frame_arch (frame);
340 if (!gdbarch_push_dummy_call_p (gdbarch))
341 error (_("This target does not support function calls."));
343 /* Create a cleanup chain that contains the retbuf (buffer
344 containing the register values). This chain is create BEFORE the
345 inf_status chain so that the inferior status can cleaned up
346 (restored or discarded) without having the retbuf freed. */
347 retbuf = regcache_xmalloc (gdbarch);
348 retbuf_cleanup = make_cleanup_regcache_xfree (retbuf);
350 /* A cleanup for the inferior status. Create this AFTER the retbuf
351 so that this can be discarded or applied without interfering with
353 inf_status = save_inferior_status (1);
354 inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status);
356 /* Save the caller's registers so that they can be restored once the
357 callee returns. To allow nested calls the registers are (further
358 down) pushed onto a dummy frame stack. Include a cleanup (which
359 is tossed once the regcache has been pushed). */
360 caller_regcache = frame_save_as_regcache (frame);
361 caller_regcache_cleanup = make_cleanup_regcache_xfree (caller_regcache);
363 /* Ensure that the initial SP is correctly aligned. */
365 CORE_ADDR old_sp = get_frame_sp (frame);
366 if (gdbarch_frame_align_p (gdbarch))
368 sp = gdbarch_frame_align (gdbarch, old_sp);
369 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
370 ABIs, a function can use memory beyond the inner most stack
371 address. AMD64 called that region the "red zone". Skip at
372 least the "red zone" size before allocating any space on
374 if (gdbarch_inner_than (gdbarch, 1, 2))
375 sp -= gdbarch_frame_red_zone_size (gdbarch);
377 sp += gdbarch_frame_red_zone_size (gdbarch);
379 gdb_assert (sp == gdbarch_frame_align (gdbarch, sp));
380 /* NOTE: cagney/2002-09-18:
382 On a RISC architecture, a void parameterless generic dummy
383 frame (i.e., no parameters, no result) typically does not
384 need to push anything the stack and hence can leave SP and
385 FP. Similarly, a frameless (possibly leaf) function does
386 not push anything on the stack and, hence, that too can
387 leave FP and SP unchanged. As a consequence, a sequence of
388 void parameterless generic dummy frame calls to frameless
389 functions will create a sequence of effectively identical
390 frames (SP, FP and TOS and PC the same). This, not
391 suprisingly, results in what appears to be a stack in an
392 infinite loop --- when GDB tries to find a generic dummy
393 frame on the internal dummy frame stack, it will always
396 To avoid this problem, the code below always grows the
397 stack. That way, two dummy frames can never be identical.
398 It does burn a few bytes of stack but that is a small price
402 if (gdbarch_inner_than (gdbarch, 1, 2))
403 /* Stack grows down. */
404 sp = gdbarch_frame_align (gdbarch, old_sp - 1);
406 /* Stack grows up. */
407 sp = gdbarch_frame_align (gdbarch, old_sp + 1);
409 gdb_assert ((gdbarch_inner_than (gdbarch, 1, 2)
411 || (gdbarch_inner_than (gdbarch, 2, 1)
415 /* FIXME: cagney/2002-09-18: Hey, you loose!
417 Who knows how badly aligned the SP is!
419 If the generic dummy frame ends up empty (because nothing is
420 pushed) GDB won't be able to correctly perform back traces.
421 If a target is having trouble with backtraces, first thing to
422 do is add FRAME_ALIGN() to the architecture vector. If that
423 fails, try dummy_id().
425 If the ABI specifies a "Red Zone" (see the doco) the code
426 below will quietly trash it. */
430 funaddr = find_function_addr (function, &values_type);
432 values_type = builtin_type (gdbarch)->builtin_int;
434 CHECK_TYPEDEF (values_type);
436 /* Are we returning a value using a structure return (passing a
437 hidden argument pointing to storage) or a normal value return?
438 There are two cases: language-mandated structure return and
439 target ABI structure return. The variable STRUCT_RETURN only
440 describes the latter. The language version is handled by passing
441 the return location as the first parameter to the function,
442 even preceding "this". This is different from the target
443 ABI version, which is target-specific; for instance, on ia64
444 the first argument is passed in out0 but the hidden structure
445 return pointer would normally be passed in r8. */
447 if (language_pass_by_reference (values_type))
449 lang_struct_return = 1;
451 /* Tell the target specific argument pushing routine not to
453 target_values_type = builtin_type_void;
457 struct_return = using_struct_return (value_type (function), values_type);
458 target_values_type = values_type;
461 /* Determine the location of the breakpoint (and possibly other
462 stuff) that the called function will return to. The SPARC, for a
463 function returning a structure or union, needs to make space for
464 not just the breakpoint but also an extra word containing the
465 size (?) of the structure being passed. */
467 /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
468 is no need to write that out. */
470 switch (gdbarch_call_dummy_location (gdbarch))
473 sp = push_dummy_code (gdbarch, sp, funaddr,
474 args, nargs, target_values_type,
475 &real_pc, &bp_addr, get_current_regcache ());
479 CORE_ADDR dummy_addr;
482 dummy_addr = entry_point_address ();
483 /* Make certain that the address points at real code, and not a
484 function descriptor. */
485 dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch,
488 /* A call dummy always consists of just a single breakpoint, so
489 its address is the same as the address of the dummy. */
490 bp_addr = dummy_addr;
494 /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
495 address is the location where the breakpoint should be
496 placed. Once all targets are using the overhauled frame code
497 this can be deleted - ON_STACK is a better option. */
499 struct minimal_symbol *sym;
500 CORE_ADDR dummy_addr;
502 sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL, NULL);
505 dummy_addr = SYMBOL_VALUE_ADDRESS (sym);
507 dummy_addr = entry_point_address ();
508 /* Make certain that the address points at real code, and not
509 a function descriptor. */
510 dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch,
513 /* A call dummy always consists of just a single breakpoint,
514 so it's address is the same as the address of the dummy. */
515 bp_addr = dummy_addr;
519 internal_error (__FILE__, __LINE__, _("bad switch"));
522 if (nargs < TYPE_NFIELDS (ftype))
523 error (_("Too few arguments in function call."));
527 for (i = nargs - 1; i >= 0; i--)
530 struct type *param_type;
532 /* FIXME drow/2002-05-31: Should just always mark methods as
533 prototyped. Can we respect TYPE_VARARGS? Probably not. */
534 if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
536 else if (i < TYPE_NFIELDS (ftype))
537 prototyped = TYPE_PROTOTYPED (ftype);
541 if (i < TYPE_NFIELDS (ftype))
542 param_type = TYPE_FIELD_TYPE (ftype, i);
546 args[i] = value_arg_coerce (gdbarch, args[i],
547 param_type, prototyped, &sp);
549 if (param_type != NULL && language_pass_by_reference (param_type))
550 args[i] = value_addr (args[i]);
554 /* Reserve space for the return structure to be written on the
555 stack, if necessary. Make certain that the value is correctly
558 if (struct_return || lang_struct_return)
560 int len = TYPE_LENGTH (values_type);
561 if (gdbarch_inner_than (gdbarch, 1, 2))
563 /* Stack grows downward. Align STRUCT_ADDR and SP after
564 making space for the return value. */
566 if (gdbarch_frame_align_p (gdbarch))
567 sp = gdbarch_frame_align (gdbarch, sp);
572 /* Stack grows upward. Align the frame, allocate space, and
573 then again, re-align the frame??? */
574 if (gdbarch_frame_align_p (gdbarch))
575 sp = gdbarch_frame_align (gdbarch, sp);
578 if (gdbarch_frame_align_p (gdbarch))
579 sp = gdbarch_frame_align (gdbarch, sp);
583 if (lang_struct_return)
585 struct value **new_args;
587 /* Add the new argument to the front of the argument list. */
588 new_args = xmalloc (sizeof (struct value *) * (nargs + 1));
589 new_args[0] = value_from_pointer (lookup_pointer_type (values_type),
591 memcpy (&new_args[1], &args[0], sizeof (struct value *) * nargs);
594 args_cleanup = make_cleanup (xfree, args);
597 args_cleanup = make_cleanup (null_cleanup, NULL);
599 /* Create the dummy stack frame. Pass in the call dummy address as,
600 presumably, the ABI code knows where, in the call dummy, the
601 return address should be pointed. */
602 sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (),
603 bp_addr, nargs, args,
604 sp, struct_return, struct_addr);
606 do_cleanups (args_cleanup);
608 /* Set up a frame ID for the dummy frame so we can pass it to
609 set_momentary_breakpoint. We need to give the breakpoint a frame
610 ID so that the breakpoint code can correctly re-identify the
612 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
613 saved as the dummy-frame TOS, and used by dummy_id to form
614 the frame ID's stack address. */
615 dummy_id = frame_id_build (sp, bp_addr);
617 /* Create a momentary breakpoint at the return address of the
618 inferior. That way it breaks when it returns. */
621 struct breakpoint *bpt;
622 struct symtab_and_line sal;
623 init_sal (&sal); /* initialize to zeroes */
625 sal.section = find_pc_overlay (sal.pc);
626 /* Sanity. The exact same SP value is returned by
627 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
628 dummy_id to form the frame ID's stack address. */
629 bpt = set_momentary_breakpoint (sal, dummy_id, bp_call_dummy);
630 bpt->disposition = disp_del;
633 /* Everything's ready, push all the info needed to restore the
634 caller (and identify the dummy-frame) onto the dummy-frame
636 dummy_frame_push (caller_regcache, &dummy_id);
637 discard_cleanups (caller_regcache_cleanup);
639 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
640 If you're looking to implement asynchronous dummy-frames, then
641 just below is the place to chop this function in two.. */
643 /* Now proceed, having reached the desired place. */
644 clear_proceed_status ();
646 /* Execute a "stack dummy", a piece of code stored in the stack by
647 the debugger to be executed in the inferior.
649 The dummy's frame is automatically popped whenever that break is
650 hit. If that is the first time the program stops,
651 call_function_by_hand returns to its caller with that frame
652 already gone and sets RC to 0.
654 Otherwise, set RC to a non-zero value. If the called function
655 receives a random signal, we do not allow the user to continue
656 executing it as this may not work. The dummy frame is poped and
657 we return 1. If we hit a breakpoint, we leave the frame in place
658 and return 2 (the frame will eventually be popped when we do hit
659 the dummy end breakpoint). */
662 struct cleanup *old_cleanups = make_cleanup (null_cleanup, 0);
663 struct cleanup *old_cleanups2;
665 struct thread_info *tp = inferior_thread ();
667 /* If all error()s out of proceed ended up calling normal_stop
668 (and perhaps they should; it already does in the special case
669 of error out of resume()), then we wouldn't need this. */
670 make_cleanup (breakpoint_auto_delete_contents, NULL);
672 disable_watchpoints_before_interactive_call_start ();
673 tp->proceed_to_finish = 1; /* We want stop_registers, please... */
675 if (target_can_async_p ())
676 saved_async = target_async_mask (0);
678 old_cleanups2 = make_cleanup_restore_integer (&suppress_resume_observer);
679 suppress_resume_observer = 1;
680 make_cleanup_restore_integer (&suppress_stop_observer);
681 suppress_stop_observer = 1;
682 proceed (real_pc, TARGET_SIGNAL_0, 0);
683 do_cleanups (old_cleanups2);
686 target_async_mask (saved_async);
688 enable_watchpoints_after_interactive_call_stop ();
690 discard_cleanups (old_cleanups);
693 if (! target_has_execution)
695 /* If we try to restore the inferior status (via the cleanup),
696 we'll crash as the inferior is no longer running. */
697 discard_cleanups (inf_status_cleanup);
698 discard_inferior_status (inf_status);
700 The program being debugged exited while in a function called from GDB."));
703 if (stopped_by_random_signal || !stop_stack_dummy)
705 /* Find the name of the function we're about to complain about. */
706 const char *name = NULL;
708 struct symbol *symbol = find_pc_function (funaddr);
710 name = SYMBOL_PRINT_NAME (symbol);
713 /* Try the minimal symbols. */
714 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
716 name = SYMBOL_PRINT_NAME (msymbol);
720 /* Can't use a cleanup here. It is discarded, instead use
722 char *tmp = xstrprintf ("at %s", hex_string (funaddr));
723 char *a = alloca (strlen (tmp) + 1);
729 if (stopped_by_random_signal)
731 /* We stopped inside the FUNCTION because of a random
732 signal. Further execution of the FUNCTION is not
735 if (unwind_on_signal_p)
737 /* The user wants the context restored. */
739 /* We must get back to the frame we were before the
741 frame_pop (get_current_frame ());
743 /* FIXME: Insert a bunch of wrap_here; name can be very
744 long if it's a C++ name with arguments and stuff. */
746 The program being debugged was signaled while in a function called from GDB.\n\
747 GDB has restored the context to what it was before the call.\n\
748 To change this behavior use \"set unwindonsignal off\".\n\
749 Evaluation of the expression containing the function (%s) will be abandoned."),
754 /* The user wants to stay in the frame where we stopped
756 /* If we restored the inferior status (via the cleanup),
757 we would print a spurious error message (Unable to
758 restore previously selected frame), would write the
759 registers from the inf_status (which is wrong), and
760 would do other wrong things. */
761 discard_cleanups (inf_status_cleanup);
762 discard_inferior_status (inf_status);
763 /* FIXME: Insert a bunch of wrap_here; name can be very
764 long if it's a C++ name with arguments and stuff. */
766 The program being debugged was signaled while in a function called from GDB.\n\
767 GDB remains in the frame where the signal was received.\n\
768 To change this behavior use \"set unwindonsignal on\".\n\
769 Evaluation of the expression containing the function (%s) will be abandoned."),
774 if (!stop_stack_dummy)
776 /* We hit a breakpoint inside the FUNCTION. */
777 /* If we restored the inferior status (via the cleanup), we
778 would print a spurious error message (Unable to restore
779 previously selected frame), would write the registers
780 from the inf_status (which is wrong), and would do other
782 discard_cleanups (inf_status_cleanup);
783 discard_inferior_status (inf_status);
784 /* The following error message used to say "The expression
785 which contained the function call has been discarded."
786 It is a hard concept to explain in a few words. Ideally,
787 GDB would be able to resume evaluation of the expression
788 when the function finally is done executing. Perhaps
789 someday this will be implemented (it would not be easy). */
790 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
791 a C++ name with arguments and stuff. */
793 The program being debugged stopped while in a function called from GDB.\n\
794 When the function (%s) is done executing, GDB will silently\n\
795 stop (instead of continuing to evaluate the expression containing\n\
796 the function call)."), name);
799 /* The above code errors out, so ... */
800 internal_error (__FILE__, __LINE__, _("... should not be here"));
803 /* If we get here the called FUNCTION run to completion. */
805 /* On normal return, the stack dummy has been popped already. */
806 regcache_cpy_no_passthrough (retbuf, stop_registers);
808 /* Restore the inferior status, via its cleanup. At this stage,
809 leave the RETBUF alone. */
810 do_cleanups (inf_status_cleanup);
812 /* Figure out the value returned by the function. */
814 struct value *retval = NULL;
816 if (lang_struct_return)
817 retval = value_at (values_type, struct_addr);
818 else if (TYPE_CODE (target_values_type) == TYPE_CODE_VOID)
820 /* If the function returns void, don't bother fetching the
822 retval = allocate_value (values_type);
826 switch (gdbarch_return_value (gdbarch, value_type (function),
827 target_values_type, NULL, NULL, NULL))
829 case RETURN_VALUE_REGISTER_CONVENTION:
830 case RETURN_VALUE_ABI_RETURNS_ADDRESS:
831 case RETURN_VALUE_ABI_PRESERVES_ADDRESS:
832 retval = allocate_value (values_type);
833 gdbarch_return_value (gdbarch, value_type (function), values_type,
834 retbuf, value_contents_raw (retval), NULL);
836 case RETURN_VALUE_STRUCT_CONVENTION:
837 retval = value_at (values_type, struct_addr);
842 do_cleanups (retbuf_cleanup);
850 /* Provide a prototype to silence -Wmissing-prototypes. */
851 void _initialize_infcall (void);
854 _initialize_infcall (void)
856 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure,
857 &coerce_float_to_double_p, _("\
858 Set coercion of floats to doubles when calling functions."), _("\
859 Show coercion of floats to doubles when calling functions"), _("\
860 Variables of type float should generally be converted to doubles before\n\
861 calling an unprototyped function, and left alone when calling a prototyped\n\
862 function. However, some older debug info formats do not provide enough\n\
863 information to determine that a function is prototyped. If this flag is\n\
864 set, GDB will perform the conversion for a function it considers\n\
866 The default is to perform the conversion.\n"),
868 show_coerce_float_to_double_p,
869 &setlist, &showlist);
871 add_setshow_boolean_cmd ("unwindonsignal", no_class,
872 &unwind_on_signal_p, _("\
873 Set unwinding of stack if a signal is received while in a call dummy."), _("\
874 Show unwinding of stack if a signal is received while in a call dummy."), _("\
875 The unwindonsignal lets the user determine what gdb should do if a signal\n\
876 is received while in a function called from gdb (call dummy). If set, gdb\n\
877 unwinds the stack and restore the context to what as it was before the call.\n\
878 The default is to stop in the frame where the signal was received."),
880 show_unwind_on_signal_p,
881 &setlist, &showlist);