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 value *arg, struct type *param_type,
105 int is_prototyped, CORE_ADDR *sp)
107 struct type *arg_type = check_typedef (value_type (arg));
109 = param_type ? check_typedef (param_type) : arg_type;
111 /* Perform any Ada-specific coercion first. */
112 if (current_language->la_language == language_ada)
113 arg = ada_convert_actual (arg, type, sp);
115 /* Force the value to the target if we will need its address. At
116 this point, we could allocate arguments on the stack instead of
117 calling malloc if we knew that their addresses would not be
118 saved by the called function. */
119 arg = value_coerce_to_target (arg);
121 switch (TYPE_CODE (type))
125 struct value *new_value;
127 if (TYPE_CODE (arg_type) == TYPE_CODE_REF)
128 return value_cast_pointers (type, arg);
130 /* Cast the value to the reference's target type, and then
131 convert it back to a reference. This will issue an error
132 if the value was not previously in memory - in some cases
133 we should clearly be allowing this, but how? */
134 new_value = value_cast (TYPE_TARGET_TYPE (type), arg);
135 new_value = value_ref (new_value);
142 /* If we don't have a prototype, coerce to integer type if necessary. */
145 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
146 type = builtin_type_int;
148 /* Currently all target ABIs require at least the width of an integer
149 type for an argument. We may have to conditionalize the following
150 type coercion for future targets. */
151 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
152 type = builtin_type_int;
155 if (!is_prototyped && coerce_float_to_double_p)
157 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_double))
158 type = builtin_type_double;
159 else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin_type_double))
160 type = builtin_type_long_double;
164 type = lookup_pointer_type (type);
166 case TYPE_CODE_ARRAY:
167 /* Arrays are coerced to pointers to their first element, unless
168 they are vectors, in which case we want to leave them alone,
169 because they are passed by value. */
170 if (current_language->c_style_arrays)
171 if (!TYPE_VECTOR (type))
172 type = lookup_pointer_type (TYPE_TARGET_TYPE (type));
174 case TYPE_CODE_UNDEF:
176 case TYPE_CODE_STRUCT:
177 case TYPE_CODE_UNION:
180 case TYPE_CODE_RANGE:
181 case TYPE_CODE_STRING:
182 case TYPE_CODE_BITSTRING:
183 case TYPE_CODE_ERROR:
184 case TYPE_CODE_MEMBERPTR:
185 case TYPE_CODE_METHODPTR:
186 case TYPE_CODE_METHOD:
187 case TYPE_CODE_COMPLEX:
192 return value_cast (type, arg);
195 /* Determine a function's address and its return type from its value.
196 Calls error() if the function is not valid for calling. */
199 find_function_addr (struct value *function, struct type **retval_type)
201 struct type *ftype = check_typedef (value_type (function));
202 enum type_code code = TYPE_CODE (ftype);
203 struct type *value_type;
206 /* If it's a member function, just look at the function
209 /* Determine address to call. */
210 if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
212 funaddr = VALUE_ADDRESS (function);
213 value_type = TYPE_TARGET_TYPE (ftype);
215 else if (code == TYPE_CODE_PTR)
217 funaddr = value_as_address (function);
218 ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
219 if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
220 || TYPE_CODE (ftype) == TYPE_CODE_METHOD)
222 funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
225 value_type = TYPE_TARGET_TYPE (ftype);
228 value_type = builtin_type_int;
230 else if (code == TYPE_CODE_INT)
232 /* Handle the case of functions lacking debugging info.
233 Their values are characters since their addresses are char */
234 if (TYPE_LENGTH (ftype) == 1)
235 funaddr = value_as_address (value_addr (function));
238 /* Handle function descriptors lacking debug info. */
239 int found_descriptor = 0;
240 if (VALUE_LVAL (function) == lval_memory)
243 funaddr = value_as_address (value_addr (function));
245 funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
248 if (funaddr != nfunaddr)
249 found_descriptor = 1;
251 if (!found_descriptor)
252 /* Handle integer used as address of a function. */
253 funaddr = (CORE_ADDR) value_as_long (function);
256 value_type = builtin_type_int;
259 error (_("Invalid data type for function to be called."));
261 if (retval_type != NULL)
262 *retval_type = value_type;
263 return funaddr + gdbarch_deprecated_function_start_offset (current_gdbarch);
266 /* Call breakpoint_auto_delete on the current contents of the bpstat
267 of the current thread. */
270 breakpoint_auto_delete_contents (void *arg)
272 if (!ptid_equal (inferior_ptid, null_ptid))
273 breakpoint_auto_delete (inferior_thread ()->stop_bpstat);
277 generic_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 /* Something here to findout the size of a breakpoint and then
285 allocate space for it on the stack. */
287 /* This code assumes frame align. */
288 gdb_assert (gdbarch_frame_align_p (gdbarch));
289 /* Force the stack's alignment. The intent is to ensure that the SP
290 is aligned to at least a breakpoint instruction's boundary. */
291 sp = gdbarch_frame_align (gdbarch, sp);
292 /* Allocate space for, and then position the breakpoint on the
294 if (gdbarch_inner_than (gdbarch, 1, 2))
297 gdbarch_breakpoint_from_pc (gdbarch, &bppc, &bplen);
298 sp = gdbarch_frame_align (gdbarch, sp - bplen);
300 /* Should the breakpoint size/location be re-computed here? */
305 gdbarch_breakpoint_from_pc (gdbarch, bp_addr, &bplen);
306 sp = gdbarch_frame_align (gdbarch, sp + bplen);
308 /* Inferior resumes at the function entry point. */
309 (*real_pc) = funaddr;
313 /* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
314 function returns to. */
317 push_dummy_code (struct gdbarch *gdbarch,
318 CORE_ADDR sp, CORE_ADDR funaddr,
319 struct value **args, int nargs,
320 struct type *value_type,
321 CORE_ADDR *real_pc, CORE_ADDR *bp_addr,
322 struct regcache *regcache)
324 if (gdbarch_push_dummy_code_p (gdbarch))
325 return gdbarch_push_dummy_code (gdbarch, sp, funaddr,
326 args, nargs, value_type, real_pc, bp_addr,
329 return generic_push_dummy_code (gdbarch, sp, funaddr,
330 args, nargs, value_type, real_pc, bp_addr,
334 /* All this stuff with a dummy frame may seem unnecessarily complicated
335 (why not just save registers in GDB?). The purpose of pushing a dummy
336 frame which looks just like a real frame is so that if you call a
337 function and then hit a breakpoint (get a signal, etc), "backtrace"
338 will look right. Whether the backtrace needs to actually show the
339 stack at the time the inferior function was called is debatable, but
340 it certainly needs to not display garbage. So if you are contemplating
341 making dummy frames be different from normal frames, consider that. */
343 /* Perform a function call in the inferior.
344 ARGS is a vector of values of arguments (NARGS of them).
345 FUNCTION is a value, the function to be called.
346 Returns a value representing what the function returned.
347 May fail to return, if a breakpoint or signal is hit
348 during the execution of the function.
350 ARGS is modified to contain coerced values. */
353 call_function_by_hand (struct value *function, int nargs, struct value **args)
356 CORE_ADDR dummy_addr;
357 struct type *values_type, *target_values_type;
358 unsigned char struct_return = 0, lang_struct_return = 0;
359 CORE_ADDR struct_addr = 0;
360 struct regcache *retbuf;
361 struct cleanup *retbuf_cleanup;
362 struct inferior_status *inf_status;
363 struct cleanup *inf_status_cleanup;
366 struct type *ftype = check_typedef (value_type (function));
368 struct regcache *caller_regcache;
369 struct cleanup *caller_regcache_cleanup;
370 struct frame_id dummy_id;
371 struct cleanup *args_cleanup;
372 struct frame_info *frame;
373 struct gdbarch *gdbarch;
375 if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
376 ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
378 if (!target_has_execution)
381 frame = get_current_frame ();
382 gdbarch = get_frame_arch (frame);
384 if (!gdbarch_push_dummy_call_p (gdbarch))
385 error (_("This target does not support function calls"));
387 /* Create a cleanup chain that contains the retbuf (buffer
388 containing the register values). This chain is create BEFORE the
389 inf_status chain so that the inferior status can cleaned up
390 (restored or discarded) without having the retbuf freed. */
391 retbuf = regcache_xmalloc (gdbarch);
392 retbuf_cleanup = make_cleanup_regcache_xfree (retbuf);
394 /* A cleanup for the inferior status. Create this AFTER the retbuf
395 so that this can be discarded or applied without interfering with
397 inf_status = save_inferior_status (1);
398 inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status);
400 /* Save the caller's registers so that they can be restored once the
401 callee returns. To allow nested calls the registers are (further
402 down) pushed onto a dummy frame stack. Include a cleanup (which
403 is tossed once the regcache has been pushed). */
404 caller_regcache = frame_save_as_regcache (frame);
405 caller_regcache_cleanup = make_cleanup_regcache_xfree (caller_regcache);
407 /* Ensure that the initial SP is correctly aligned. */
409 CORE_ADDR old_sp = get_frame_sp (frame);
410 if (gdbarch_frame_align_p (gdbarch))
412 sp = gdbarch_frame_align (gdbarch, old_sp);
413 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
414 ABIs, a function can use memory beyond the inner most stack
415 address. AMD64 called that region the "red zone". Skip at
416 least the "red zone" size before allocating any space on
418 if (gdbarch_inner_than (gdbarch, 1, 2))
419 sp -= gdbarch_frame_red_zone_size (gdbarch);
421 sp += gdbarch_frame_red_zone_size (gdbarch);
423 gdb_assert (sp == gdbarch_frame_align (gdbarch, sp));
424 /* NOTE: cagney/2002-09-18:
426 On a RISC architecture, a void parameterless generic dummy
427 frame (i.e., no parameters, no result) typically does not
428 need to push anything the stack and hence can leave SP and
429 FP. Similarly, a frameless (possibly leaf) function does
430 not push anything on the stack and, hence, that too can
431 leave FP and SP unchanged. As a consequence, a sequence of
432 void parameterless generic dummy frame calls to frameless
433 functions will create a sequence of effectively identical
434 frames (SP, FP and TOS and PC the same). This, not
435 suprisingly, results in what appears to be a stack in an
436 infinite loop --- when GDB tries to find a generic dummy
437 frame on the internal dummy frame stack, it will always
440 To avoid this problem, the code below always grows the
441 stack. That way, two dummy frames can never be identical.
442 It does burn a few bytes of stack but that is a small price
446 if (gdbarch_inner_than (gdbarch, 1, 2))
447 /* Stack grows down. */
448 sp = gdbarch_frame_align (gdbarch, old_sp - 1);
450 /* Stack grows up. */
451 sp = gdbarch_frame_align (gdbarch, old_sp + 1);
453 gdb_assert ((gdbarch_inner_than (gdbarch, 1, 2)
455 || (gdbarch_inner_than (gdbarch, 2, 1)
459 /* FIXME: cagney/2002-09-18: Hey, you loose!
461 Who knows how badly aligned the SP is!
463 If the generic dummy frame ends up empty (because nothing is
464 pushed) GDB won't be able to correctly perform back traces.
465 If a target is having trouble with backtraces, first thing to
466 do is add FRAME_ALIGN() to the architecture vector. If that
467 fails, try dummy_id().
469 If the ABI specifies a "Red Zone" (see the doco) the code
470 below will quietly trash it. */
474 funaddr = find_function_addr (function, &values_type);
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 (args[i], param_type, prototyped, &sp);
597 if (param_type != NULL && language_pass_by_reference (param_type))
598 args[i] = value_addr (args[i]);
602 /* Reserve space for the return structure to be written on the
603 stack, if necessary. Make certain that the value is correctly
606 if (struct_return || lang_struct_return)
608 int len = TYPE_LENGTH (values_type);
609 if (gdbarch_inner_than (gdbarch, 1, 2))
611 /* Stack grows downward. Align STRUCT_ADDR and SP after
612 making space for the return value. */
614 if (gdbarch_frame_align_p (gdbarch))
615 sp = gdbarch_frame_align (gdbarch, sp);
620 /* Stack grows upward. Align the frame, allocate space, and
621 then again, re-align the frame??? */
622 if (gdbarch_frame_align_p (gdbarch))
623 sp = gdbarch_frame_align (gdbarch, sp);
626 if (gdbarch_frame_align_p (gdbarch))
627 sp = gdbarch_frame_align (gdbarch, sp);
631 if (lang_struct_return)
633 struct value **new_args;
635 /* Add the new argument to the front of the argument list. */
636 new_args = xmalloc (sizeof (struct value *) * (nargs + 1));
637 new_args[0] = value_from_pointer (lookup_pointer_type (values_type),
639 memcpy (&new_args[1], &args[0], sizeof (struct value *) * nargs);
642 args_cleanup = make_cleanup (xfree, args);
645 args_cleanup = make_cleanup (null_cleanup, NULL);
647 /* Create the dummy stack frame. Pass in the call dummy address as,
648 presumably, the ABI code knows where, in the call dummy, the
649 return address should be pointed. */
650 sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (),
651 bp_addr, nargs, args,
652 sp, struct_return, struct_addr);
654 do_cleanups (args_cleanup);
656 /* Set up a frame ID for the dummy frame so we can pass it to
657 set_momentary_breakpoint. We need to give the breakpoint a frame
658 ID so that the breakpoint code can correctly re-identify the
660 /* Sanity. The exact same SP value is returned by PUSH_DUMMY_CALL,
661 saved as the dummy-frame TOS, and used by dummy_id to form
662 the frame ID's stack address. */
663 dummy_id = frame_id_build (sp, bp_addr);
665 /* Create a momentary breakpoint at the return address of the
666 inferior. That way it breaks when it returns. */
669 struct breakpoint *bpt;
670 struct symtab_and_line sal;
671 init_sal (&sal); /* initialize to zeroes */
673 sal.section = find_pc_overlay (sal.pc);
674 /* Sanity. The exact same SP value is returned by
675 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
676 dummy_id to form the frame ID's stack address. */
677 bpt = set_momentary_breakpoint (sal, dummy_id, bp_call_dummy);
678 bpt->disposition = disp_del;
681 /* Everything's ready, push all the info needed to restore the
682 caller (and identify the dummy-frame) onto the dummy-frame
684 dummy_frame_push (caller_regcache, &dummy_id);
685 discard_cleanups (caller_regcache_cleanup);
687 /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
688 If you're looking to implement asynchronous dummy-frames, then
689 just below is the place to chop this function in two.. */
691 /* Now proceed, having reached the desired place. */
692 clear_proceed_status ();
694 /* Execute a "stack dummy", a piece of code stored in the stack by
695 the debugger to be executed in the inferior.
697 The dummy's frame is automatically popped whenever that break is
698 hit. If that is the first time the program stops,
699 call_function_by_hand returns to its caller with that frame
700 already gone and sets RC to 0.
702 Otherwise, set RC to a non-zero value. If the called function
703 receives a random signal, we do not allow the user to continue
704 executing it as this may not work. The dummy frame is poped and
705 we return 1. If we hit a breakpoint, we leave the frame in place
706 and return 2 (the frame will eventually be popped when we do hit
707 the dummy end breakpoint). */
710 struct cleanup *old_cleanups = make_cleanup (null_cleanup, 0);
711 struct cleanup *old_cleanups2;
713 struct thread_info *tp = inferior_thread ();
715 /* If all error()s out of proceed ended up calling normal_stop
716 (and perhaps they should; it already does in the special case
717 of error out of resume()), then we wouldn't need this. */
718 make_cleanup (breakpoint_auto_delete_contents, NULL);
720 disable_watchpoints_before_interactive_call_start ();
721 tp->proceed_to_finish = 1; /* We want stop_registers, please... */
723 if (target_can_async_p ())
724 saved_async = target_async_mask (0);
726 old_cleanups2 = make_cleanup_restore_integer (&suppress_resume_observer);
727 suppress_resume_observer = 1;
728 make_cleanup_restore_integer (&suppress_stop_observer);
729 suppress_stop_observer = 1;
730 proceed (real_pc, TARGET_SIGNAL_0, 0);
731 do_cleanups (old_cleanups2);
734 target_async_mask (saved_async);
736 enable_watchpoints_after_interactive_call_stop ();
738 discard_cleanups (old_cleanups);
741 if (stopped_by_random_signal || !stop_stack_dummy)
743 /* Find the name of the function we're about to complain about. */
744 const char *name = NULL;
746 struct symbol *symbol = find_pc_function (funaddr);
748 name = SYMBOL_PRINT_NAME (symbol);
751 /* Try the minimal symbols. */
752 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
754 name = SYMBOL_PRINT_NAME (msymbol);
758 /* Can't use a cleanup here. It is discarded, instead use
760 char *tmp = xstrprintf ("at %s", hex_string (funaddr));
761 char *a = alloca (strlen (tmp) + 1);
767 if (stopped_by_random_signal)
769 /* We stopped inside the FUNCTION because of a random
770 signal. Further execution of the FUNCTION is not
773 if (unwind_on_signal_p)
775 /* The user wants the context restored. */
777 /* We must get back to the frame we were before the
779 frame_pop (get_current_frame ());
781 /* FIXME: Insert a bunch of wrap_here; name can be very
782 long if it's a C++ name with arguments and stuff. */
784 The program being debugged was signaled while in a function called from GDB.\n\
785 GDB has restored the context to what it was before the call.\n\
786 To change this behavior use \"set unwindonsignal off\"\n\
787 Evaluation of the expression containing the function (%s) will be abandoned."),
792 /* The user wants to stay in the frame where we stopped
794 /* If we restored the inferior status (via the cleanup),
795 we would print a spurious error message (Unable to
796 restore previously selected frame), would write the
797 registers from the inf_status (which is wrong), and
798 would do other wrong things. */
799 discard_cleanups (inf_status_cleanup);
800 discard_inferior_status (inf_status);
801 /* FIXME: Insert a bunch of wrap_here; name can be very
802 long if it's a C++ name with arguments and stuff. */
804 The program being debugged was signaled while in a function called from GDB.\n\
805 GDB remains in the frame where the signal was received.\n\
806 To change this behavior use \"set unwindonsignal on\"\n\
807 Evaluation of the expression containing the function (%s) will be abandoned."),
812 if (!stop_stack_dummy)
814 /* We hit a breakpoint inside the FUNCTION. */
815 /* If we restored the inferior status (via the cleanup), we
816 would print a spurious error message (Unable to restore
817 previously selected frame), would write the registers
818 from the inf_status (which is wrong), and would do other
820 discard_cleanups (inf_status_cleanup);
821 discard_inferior_status (inf_status);
822 /* The following error message used to say "The expression
823 which contained the function call has been discarded."
824 It is a hard concept to explain in a few words. Ideally,
825 GDB would be able to resume evaluation of the expression
826 when the function finally is done executing. Perhaps
827 someday this will be implemented (it would not be easy). */
828 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
829 a C++ name with arguments and stuff. */
831 The program being debugged stopped while in a function called from GDB.\n\
832 When the function (%s) is done executing, GDB will silently\n\
833 stop (instead of continuing to evaluate the expression containing\n\
834 the function call)."), name);
837 /* The above code errors out, so ... */
838 internal_error (__FILE__, __LINE__, _("... should not be here"));
841 /* If we get here the called FUNCTION run to completion. */
843 /* On normal return, the stack dummy has been popped already. */
844 regcache_cpy_no_passthrough (retbuf, stop_registers);
846 /* Restore the inferior status, via its cleanup. At this stage,
847 leave the RETBUF alone. */
848 do_cleanups (inf_status_cleanup);
850 /* Figure out the value returned by the function. */
852 struct value *retval = NULL;
854 if (lang_struct_return)
855 retval = value_at (values_type, struct_addr);
856 else if (TYPE_CODE (target_values_type) == TYPE_CODE_VOID)
858 /* If the function returns void, don't bother fetching the
860 retval = allocate_value (values_type);
864 switch (gdbarch_return_value (gdbarch, value_type (function),
865 target_values_type, NULL, NULL, NULL))
867 case RETURN_VALUE_REGISTER_CONVENTION:
868 case RETURN_VALUE_ABI_RETURNS_ADDRESS:
869 case RETURN_VALUE_ABI_PRESERVES_ADDRESS:
870 retval = allocate_value (values_type);
871 gdbarch_return_value (gdbarch, value_type (function), values_type,
872 retbuf, value_contents_raw (retval), NULL);
874 case RETURN_VALUE_STRUCT_CONVENTION:
875 retval = value_at (values_type, struct_addr);
880 do_cleanups (retbuf_cleanup);
888 /* Provide a prototype to silence -Wmissing-prototypes. */
889 void _initialize_infcall (void);
892 _initialize_infcall (void)
894 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure,
895 &coerce_float_to_double_p, _("\
896 Set coercion of floats to doubles when calling functions."), _("\
897 Show coercion of floats to doubles when calling functions"), _("\
898 Variables of type float should generally be converted to doubles before\n\
899 calling an unprototyped function, and left alone when calling a prototyped\n\
900 function. However, some older debug info formats do not provide enough\n\
901 information to determine that a function is prototyped. If this flag is\n\
902 set, GDB will perform the conversion for a function it considers\n\
904 The default is to perform the conversion.\n"),
906 show_coerce_float_to_double_p,
907 &setlist, &showlist);
909 add_setshow_boolean_cmd ("unwindonsignal", no_class,
910 &unwind_on_signal_p, _("\
911 Set unwinding of stack if a signal is received while in a call dummy."), _("\
912 Show unwinding of stack if a signal is received while in a call dummy."), _("\
913 The unwindonsignal lets the user determine what gdb should do if a signal\n\
914 is received while in a function called from gdb (call dummy). If set, gdb\n\
915 unwinds the stack and restore the context to what as it was before the call.\n\
916 The default is to stop in the frame where the signal was received."),
918 show_unwind_on_signal_p,
919 &setlist, &showlist);