1 /* Perform an inferior function call, for GDB, the GNU debugger.
3 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
4 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
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., 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
25 #include "breakpoint.h"
29 #include "gdb_assert.h"
36 #include "gdb_string.h"
39 /* NOTE: cagney/2003-04-16: What's the future of this code?
41 GDB needs an asynchronous expression evaluator, that means an
42 asynchronous inferior function call implementation, and that in
43 turn means restructuring the code so that it is event driven. */
45 /* How you should pass arguments to a function depends on whether it
46 was defined in K&R style or prototype style. If you define a
47 function using the K&R syntax that takes a `float' argument, then
48 callers must pass that argument as a `double'. If you define the
49 function using the prototype syntax, then you must pass the
50 argument as a `float', with no promotion.
52 Unfortunately, on certain older platforms, the debug info doesn't
53 indicate reliably how each function was defined. A function type's
54 TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
55 defined in prototype style. When calling a function whose
56 TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to
59 For modern targets, it is proper to assume that, if the prototype
60 flag is clear, that can be trusted: `float' arguments should be
61 promoted to `double'. For some older targets, if the prototype
62 flag is clear, that doesn't tell us anything. The default is to
63 trust the debug information; the user can override this behavior
64 with "set coerce-float-to-double 0". */
66 static int coerce_float_to_double_p = 1;
68 /* This boolean tells what gdb should do if a signal is received while
69 in a function called from gdb (call dummy). If set, gdb unwinds
70 the stack and restore the context to what as it was before the
73 The default is to stop in the frame where the signal was received. */
75 int unwind_on_signal_p = 0;
77 /* Perform the standard coercions that are specified
78 for arguments to be passed to C functions.
80 If PARAM_TYPE is non-NULL, it is the expected parameter type.
81 IS_PROTOTYPED is non-zero if the function declaration is prototyped. */
84 value_arg_coerce (struct value *arg, struct type *param_type,
87 struct type *arg_type = check_typedef (VALUE_TYPE (arg));
89 = param_type ? check_typedef (param_type) : arg_type;
91 switch (TYPE_CODE (type))
94 if (TYPE_CODE (arg_type) != TYPE_CODE_REF
95 && TYPE_CODE (arg_type) != TYPE_CODE_PTR)
97 arg = value_addr (arg);
98 VALUE_TYPE (arg) = param_type;
106 /* If we don't have a prototype, coerce to integer type if necessary. */
109 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
110 type = builtin_type_int;
112 /* Currently all target ABIs require at least the width of an integer
113 type for an argument. We may have to conditionalize the following
114 type coercion for future targets. */
115 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_int))
116 type = builtin_type_int;
119 if (!is_prototyped && coerce_float_to_double_p)
121 if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin_type_double))
122 type = builtin_type_double;
123 else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin_type_double))
124 type = builtin_type_long_double;
128 type = lookup_pointer_type (type);
130 case TYPE_CODE_ARRAY:
131 /* Arrays are coerced to pointers to their first element, unless
132 they are vectors, in which case we want to leave them alone,
133 because they are passed by value. */
134 if (current_language->c_style_arrays)
135 if (!TYPE_VECTOR (type))
136 type = lookup_pointer_type (TYPE_TARGET_TYPE (type));
138 case TYPE_CODE_UNDEF:
140 case TYPE_CODE_STRUCT:
141 case TYPE_CODE_UNION:
144 case TYPE_CODE_RANGE:
145 case TYPE_CODE_STRING:
146 case TYPE_CODE_BITSTRING:
147 case TYPE_CODE_ERROR:
148 case TYPE_CODE_MEMBER:
149 case TYPE_CODE_METHOD:
150 case TYPE_CODE_COMPLEX:
155 return value_cast (type, arg);
158 /* Determine a function's address and its return type from its value.
159 Calls error() if the function is not valid for calling. */
162 find_function_addr (struct value *function, struct type **retval_type)
164 struct type *ftype = check_typedef (VALUE_TYPE (function));
165 enum type_code code = TYPE_CODE (ftype);
166 struct type *value_type;
169 /* If it's a member function, just look at the function
172 /* Determine address to call. */
173 if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
175 funaddr = VALUE_ADDRESS (function);
176 value_type = TYPE_TARGET_TYPE (ftype);
178 else if (code == TYPE_CODE_PTR)
180 funaddr = value_as_address (function);
181 ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
182 if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
183 || TYPE_CODE (ftype) == TYPE_CODE_METHOD)
185 funaddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
188 value_type = TYPE_TARGET_TYPE (ftype);
191 value_type = builtin_type_int;
193 else if (code == TYPE_CODE_INT)
195 /* Handle the case of functions lacking debugging info.
196 Their values are characters since their addresses are char */
197 if (TYPE_LENGTH (ftype) == 1)
198 funaddr = value_as_address (value_addr (function));
200 /* Handle integer used as address of a function. */
201 funaddr = (CORE_ADDR) value_as_long (function);
203 value_type = builtin_type_int;
206 error ("Invalid data type for function to be called.");
208 *retval_type = value_type;
209 return funaddr + FUNCTION_START_OFFSET;
212 /* Call breakpoint_auto_delete on the current contents of the bpstat
213 pointed to by arg (which is really a bpstat *). */
216 breakpoint_auto_delete_contents (void *arg)
218 breakpoint_auto_delete (*(bpstat *) arg);
222 legacy_push_dummy_code (struct gdbarch *gdbarch,
223 CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc,
224 struct value **args, int nargs,
225 struct type *value_type,
226 CORE_ADDR *real_pc, CORE_ADDR *bp_addr)
228 /* CALL_DUMMY is an array of words (DEPRECATED_REGISTER_SIZE), but
229 each word is in host byte order. Before calling
230 DEPRECATED_FIX_CALL_DUMMY, we byteswap it and remove any extra
231 bytes which might exist because ULONGEST is bigger than
232 DEPRECATED_REGISTER_SIZE. */
233 /* NOTE: This is pretty wierd, as the call dummy is actually a
234 sequence of instructions. But CISC machines will have to pack
235 the instructions into DEPRECATED_REGISTER_SIZE units (and so will
236 RISC machines for which INSTRUCTION_SIZE is not
237 DEPRECATED_REGISTER_SIZE). */
238 /* NOTE: This is pretty stupid. CALL_DUMMY should be in strict
239 target byte order. */
241 ULONGEST *dummy = alloca (DEPRECATED_SIZEOF_CALL_DUMMY_WORDS);
242 int sizeof_dummy1 = (DEPRECATED_REGISTER_SIZE
243 * DEPRECATED_SIZEOF_CALL_DUMMY_WORDS
244 / sizeof (ULONGEST));
245 char *dummy1 = alloca (sizeof_dummy1);
246 memcpy (dummy, DEPRECATED_CALL_DUMMY_WORDS,
247 DEPRECATED_SIZEOF_CALL_DUMMY_WORDS);
248 if (INNER_THAN (1, 2))
250 /* Stack grows down */
260 /* NOTE: cagney/2002-09-10: Don't bother re-adjusting the stack
261 after allocating space for the call dummy. A target can specify
262 a SIZEOF_DUMMY1 (via DEPRECATED_SIZEOF_CALL_DUMMY_WORDS) such
263 that all local alignment requirements are met. */
264 /* Create a call sequence customized for this function and the
265 number of arguments for it. */
268 for (i = 0; i < (int) (DEPRECATED_SIZEOF_CALL_DUMMY_WORDS / sizeof (dummy[0]));
270 store_unsigned_integer (&dummy1[i * DEPRECATED_REGISTER_SIZE],
271 DEPRECATED_REGISTER_SIZE,
272 (ULONGEST) dummy[i]);
274 /* NOTE: cagney/2003-04-22: This computation of REAL_PC, BP_ADDR and
275 DUMMY_ADDR is pretty messed up. It comes from constant tinkering
276 with the values. Instead a DEPRECATED_FIX_CALL_DUMMY replacement
277 (PUSH_DUMMY_BREAKPOINT?) should just do everything. */
278 if (!gdbarch_push_dummy_call_p (current_gdbarch))
280 if (DEPRECATED_FIX_CALL_DUMMY_P ())
282 /* gdb_assert (CALL_DUMMY_LOCATION == ON_STACK) true? */
283 DEPRECATED_FIX_CALL_DUMMY (dummy1, start_sp, funaddr, nargs, args,
284 value_type, using_gcc);
286 (*real_pc) = start_sp;
288 /* Yes, the offset is applied to the real_pc and not the dummy addr.
289 Ulgh! Blame the HP/UX target. */
290 (*bp_addr) = (*real_pc) + DEPRECATED_CALL_DUMMY_BREAKPOINT_OFFSET;
291 /* Yes, the offset is applied to the real_pc and not the
292 dummy_addr. Ulgh! Blame the HP/UX target. */
293 (*real_pc) += DEPRECATED_CALL_DUMMY_START_OFFSET;
294 write_memory (start_sp, (char *) dummy1, sizeof_dummy1);
295 generic_save_call_dummy_addr (start_sp, start_sp + sizeof_dummy1);
300 generic_push_dummy_code (struct gdbarch *gdbarch,
301 CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc,
302 struct value **args, int nargs,
303 struct type *value_type,
304 CORE_ADDR *real_pc, CORE_ADDR *bp_addr)
306 /* Something here to findout the size of a breakpoint and then
307 allocate space for it on the stack. */
309 /* This code assumes frame align. */
310 gdb_assert (gdbarch_frame_align_p (gdbarch));
311 /* Force the stack's alignment. The intent is to ensure that the SP
312 is aligned to at least a breakpoint instruction's boundary. */
313 sp = gdbarch_frame_align (gdbarch, sp);
314 /* Allocate space for, and then position the breakpoint on the
316 if (gdbarch_inner_than (gdbarch, 1, 2))
319 gdbarch_breakpoint_from_pc (gdbarch, &bppc, &bplen);
320 sp = gdbarch_frame_align (gdbarch, sp - bplen);
322 /* Should the breakpoint size/location be re-computed here? */
327 gdbarch_breakpoint_from_pc (gdbarch, bp_addr, &bplen);
328 sp = gdbarch_frame_align (gdbarch, sp + bplen);
330 /* Inferior resumes at the function entry point. */
331 (*real_pc) = funaddr;
335 /* Provide backward compatibility. Once DEPRECATED_FIX_CALL_DUMMY is
336 eliminated, this can be simplified. */
339 push_dummy_code (struct gdbarch *gdbarch,
340 CORE_ADDR sp, CORE_ADDR funaddr, int using_gcc,
341 struct value **args, int nargs,
342 struct type *value_type,
343 CORE_ADDR *real_pc, CORE_ADDR *bp_addr)
345 if (gdbarch_push_dummy_code_p (gdbarch))
346 return gdbarch_push_dummy_code (gdbarch, sp, funaddr, using_gcc,
347 args, nargs, value_type, real_pc, bp_addr);
348 else if (DEPRECATED_FIX_CALL_DUMMY_P ()
349 && !gdbarch_push_dummy_call_p (gdbarch))
350 return legacy_push_dummy_code (gdbarch, sp, funaddr, using_gcc,
351 args, nargs, value_type, real_pc, bp_addr);
353 return generic_push_dummy_code (gdbarch, sp, funaddr, using_gcc,
354 args, nargs, value_type, real_pc, bp_addr);
357 /* All this stuff with a dummy frame may seem unnecessarily complicated
358 (why not just save registers in GDB?). The purpose of pushing a dummy
359 frame which looks just like a real frame is so that if you call a
360 function and then hit a breakpoint (get a signal, etc), "backtrace"
361 will look right. Whether the backtrace needs to actually show the
362 stack at the time the inferior function was called is debatable, but
363 it certainly needs to not display garbage. So if you are contemplating
364 making dummy frames be different from normal frames, consider that. */
366 /* Perform a function call in the inferior.
367 ARGS is a vector of values of arguments (NARGS of them).
368 FUNCTION is a value, the function to be called.
369 Returns a value representing what the function returned.
370 May fail to return, if a breakpoint or signal is hit
371 during the execution of the function.
373 ARGS is modified to contain coerced values. */
376 call_function_by_hand (struct value *function, int nargs, struct value **args)
379 CORE_ADDR dummy_addr;
380 struct type *value_type;
381 unsigned char struct_return;
382 CORE_ADDR struct_addr = 0;
383 struct regcache *retbuf;
384 struct cleanup *retbuf_cleanup;
385 struct inferior_status *inf_status;
386 struct cleanup *inf_status_cleanup;
388 int using_gcc; /* Set to version of gcc in use, or zero if not gcc */
390 struct type *ftype = check_typedef (SYMBOL_TYPE (function));
393 if (!target_has_execution)
396 /* Create a cleanup chain that contains the retbuf (buffer
397 containing the register values). This chain is create BEFORE the
398 inf_status chain so that the inferior status can cleaned up
399 (restored or discarded) without having the retbuf freed. */
400 retbuf = regcache_xmalloc (current_gdbarch);
401 retbuf_cleanup = make_cleanup_regcache_xfree (retbuf);
403 /* A cleanup for the inferior status. Create this AFTER the retbuf
404 so that this can be discarded or applied without interfering with
406 inf_status = save_inferior_status (1);
407 inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status);
409 if (DEPRECATED_PUSH_DUMMY_FRAME_P ())
411 /* DEPRECATED_PUSH_DUMMY_FRAME is responsible for saving the
412 inferior registers (and frame_pop() for restoring them). (At
413 least on most machines) they are saved on the stack in the
415 DEPRECATED_PUSH_DUMMY_FRAME;
419 /* FIXME: cagney/2003-02-26: Step zero of this little tinker is
420 to extract the generic dummy frame code from the architecture
421 vector. Hence this direct call.
423 A follow-on change is to modify this interface so that it takes
424 thread OR frame OR ptid as a parameter, and returns a dummy
425 frame handle. The handle can then be used further down as a
426 parameter to generic_save_dummy_frame_tos(). Hmm, thinking
427 about it, since everything is ment to be using generic dummy
428 frames, why not even use some of the dummy frame code to here -
429 do a regcache dup and then pass the duped regcache, along with
430 all the other stuff, at one single point.
432 In fact, you can even save the structure's return address in the
433 dummy frame and fix one of those nasty lost struct return edge
435 generic_push_dummy_frame ();
438 /* Ensure that the initial SP is correctly aligned. */
440 CORE_ADDR old_sp = read_sp ();
441 if (gdbarch_frame_align_p (current_gdbarch))
443 sp = gdbarch_frame_align (current_gdbarch, old_sp);
444 /* NOTE: cagney/2003-08-13: Skip the "red zone". For some
445 ABIs, a function can use memory beyond the inner most stack
446 address. AMD64 called that region the "red zone". Skip at
447 least the "red zone" size before allocating any space on
449 if (INNER_THAN (1, 2))
450 sp -= gdbarch_frame_red_zone_size (current_gdbarch);
452 sp += gdbarch_frame_red_zone_size (current_gdbarch);
454 gdb_assert (sp == gdbarch_frame_align (current_gdbarch, sp));
455 /* NOTE: cagney/2002-09-18:
457 On a RISC architecture, a void parameterless generic dummy
458 frame (i.e., no parameters, no result) typically does not
459 need to push anything the stack and hence can leave SP and
460 FP. Similarly, a frameless (possibly leaf) function does
461 not push anything on the stack and, hence, that too can
462 leave FP and SP unchanged. As a consequence, a sequence of
463 void parameterless generic dummy frame calls to frameless
464 functions will create a sequence of effectively identical
465 frames (SP, FP and TOS and PC the same). This, not
466 suprisingly, results in what appears to be a stack in an
467 infinite loop --- when GDB tries to find a generic dummy
468 frame on the internal dummy frame stack, it will always
471 To avoid this problem, the code below always grows the
472 stack. That way, two dummy frames can never be identical.
473 It does burn a few bytes of stack but that is a small price
477 if (INNER_THAN (1, 2))
478 /* Stack grows down. */
479 sp = gdbarch_frame_align (current_gdbarch, old_sp - 1);
481 /* Stack grows up. */
482 sp = gdbarch_frame_align (current_gdbarch, old_sp + 1);
484 gdb_assert ((INNER_THAN (1, 2) && sp <= old_sp)
485 || (INNER_THAN (2, 1) && sp >= old_sp));
488 /* FIXME: cagney/2002-09-18: Hey, you loose!
490 Who knows how badly aligned the SP is!
492 If the generic dummy frame ends up empty (because nothing is
493 pushed) GDB won't be able to correctly perform back traces.
494 If a target is having trouble with backtraces, first thing to
495 do is add FRAME_ALIGN() to the architecture vector. If that
496 fails, try unwind_dummy_id().
498 If the ABI specifies a "Red Zone" (see the doco) the code
499 below will quietly trash it. */
503 funaddr = find_function_addr (function, &value_type);
504 CHECK_TYPEDEF (value_type);
507 struct block *b = block_for_pc (funaddr);
508 /* If compiled without -g, assume GCC 2. */
509 using_gcc = (b == NULL ? 2 : BLOCK_GCC_COMPILED (b));
512 /* Are we returning a value using a structure return or a normal
515 struct_return = using_struct_return (value_type, using_gcc);
517 /* Determine the location of the breakpoint (and possibly other
518 stuff) that the called function will return to. The SPARC, for a
519 function returning a structure or union, needs to make space for
520 not just the breakpoint but also an extra word containing the
521 size (?) of the structure being passed. */
523 /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
524 is no need to write that out. */
526 switch (CALL_DUMMY_LOCATION)
529 /* "dummy_addr" is here just to keep old targets happy. New
530 targets return that same information via "sp" and "bp_addr". */
531 if (INNER_THAN (1, 2))
533 sp = push_dummy_code (current_gdbarch, sp, funaddr,
534 using_gcc, args, nargs, value_type,
541 sp = push_dummy_code (current_gdbarch, sp, funaddr,
542 using_gcc, args, nargs, value_type,
547 if (DEPRECATED_FIX_CALL_DUMMY_P ()
548 && !gdbarch_push_dummy_call_p (current_gdbarch))
550 /* Sigh. Some targets use DEPRECATED_FIX_CALL_DUMMY to
551 shove extra stuff onto the stack or into registers. That
552 code should be in PUSH_DUMMY_CALL, however, in the mean
554 /* If the target is manipulating DUMMY1, it looses big time. */
556 DEPRECATED_FIX_CALL_DUMMY (dummy1, sp, funaddr, nargs, args,
557 value_type, using_gcc);
560 dummy_addr = entry_point_address ();
561 /* Make certain that the address points at real code, and not a
562 function descriptor. */
563 dummy_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
566 /* A call dummy always consists of just a single breakpoint, so
567 it's address is the same as the address of the dummy. */
568 bp_addr = dummy_addr;
571 /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
572 address is the location where the breakpoint should be
573 placed. Once all targets are using the overhauled frame code
574 this can be deleted - ON_STACK is a better option. */
576 struct minimal_symbol *sym;
578 sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL, NULL);
581 dummy_addr = SYMBOL_VALUE_ADDRESS (sym);
583 dummy_addr = entry_point_address ();
584 /* Make certain that the address points at real code, and not
585 a function descriptor. */
586 dummy_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
589 /* A call dummy always consists of just a single breakpoint,
590 so it's address is the same as the address of the dummy. */
591 bp_addr = dummy_addr;
595 internal_error (__FILE__, __LINE__, "bad switch");
598 /* Save where the breakpoint is going to be inserted so that the
599 dummy-frame code is later able to re-identify it. */
600 generic_save_call_dummy_addr (bp_addr, bp_addr + 1);
602 if (nargs < TYPE_NFIELDS (ftype))
603 error ("too few arguments in function call");
607 for (i = nargs - 1; i >= 0; i--)
610 struct type *param_type;
612 /* FIXME drow/2002-05-31: Should just always mark methods as
613 prototyped. Can we respect TYPE_VARARGS? Probably not. */
614 if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
616 else if (i < TYPE_NFIELDS (ftype))
617 prototyped = TYPE_PROTOTYPED (ftype);
621 if (i < TYPE_NFIELDS (ftype))
622 param_type = TYPE_FIELD_TYPE (ftype, i);
626 args[i] = value_arg_coerce (args[i], param_type, prototyped);
628 /* elz: this code is to handle the case in which the function
629 to be called has a pointer to function as parameter and the
630 corresponding actual argument is the address of a function
631 and not a pointer to function variable. In aCC compiled
632 code, the calls through pointers to functions (in the body
633 of the function called by hand) are made via
634 $$dyncall_external which requires some registers setting,
635 this is taken care of if we call via a function pointer
636 variable, but not via a function address. In cc this is
641 if (param_type != NULL && TYPE_CODE (ftype) != TYPE_CODE_METHOD)
643 /* if this parameter is a pointer to function. */
644 if (TYPE_CODE (param_type) == TYPE_CODE_PTR)
645 if (TYPE_CODE (TYPE_TARGET_TYPE (param_type)) == TYPE_CODE_FUNC)
646 /* elz: FIXME here should go the test about the
647 compiler used to compile the target. We want to
648 issue the error message only if the compiler
649 used was HP's aCC. If we used HP's cc, then
650 there is no problem and no need to return at
652 /* Go see if the actual parameter is a variable of
653 type pointer to function or just a function. */
654 if (args[i]->lval == not_lval)
657 if (find_pc_partial_function ((CORE_ADDR) args[i]->aligner.contents[0], &arg_name, NULL, NULL))
659 You cannot use function <%s> as argument. \n\
660 You must use a pointer to function type variable. Command ignored.", arg_name);
667 if (DEPRECATED_REG_STRUCT_HAS_ADDR_P ())
670 /* This is a machine like the sparc, where we may need to pass a
671 pointer to the structure, not the structure itself. */
672 for (i = nargs - 1; i >= 0; i--)
674 struct type *arg_type = check_typedef (VALUE_TYPE (args[i]));
675 if ((TYPE_CODE (arg_type) == TYPE_CODE_STRUCT
676 || TYPE_CODE (arg_type) == TYPE_CODE_UNION
677 || TYPE_CODE (arg_type) == TYPE_CODE_ARRAY
678 || TYPE_CODE (arg_type) == TYPE_CODE_STRING
679 || TYPE_CODE (arg_type) == TYPE_CODE_BITSTRING
680 || TYPE_CODE (arg_type) == TYPE_CODE_SET
681 || (TYPE_CODE (arg_type) == TYPE_CODE_FLT
682 && TYPE_LENGTH (arg_type) > 8)
684 && DEPRECATED_REG_STRUCT_HAS_ADDR (using_gcc, arg_type))
687 int len; /* = TYPE_LENGTH (arg_type); */
689 arg_type = check_typedef (VALUE_ENCLOSING_TYPE (args[i]));
690 len = TYPE_LENGTH (arg_type);
692 if (DEPRECATED_STACK_ALIGN_P ())
693 /* MVS 11/22/96: I think at least some of this
694 stack_align code is really broken. Better to let
695 PUSH_ARGUMENTS adjust the stack in a target-defined
697 aligned_len = DEPRECATED_STACK_ALIGN (len);
700 if (INNER_THAN (1, 2))
702 /* stack grows downward */
704 /* ... so the address of the thing we push is the
705 stack pointer after we push it. */
710 /* The stack grows up, so the address of the thing
711 we push is the stack pointer before we push it. */
715 /* Push the structure. */
716 write_memory (addr, VALUE_CONTENTS_ALL (args[i]), len);
717 /* The value we're going to pass is the address of the
718 thing we just pushed. */
719 /*args[i] = value_from_longest (lookup_pointer_type (value_type),
721 args[i] = value_from_pointer (lookup_pointer_type (arg_type),
728 /* Reserve space for the return structure to be written on the
729 stack, if necessary. Make certain that the value is correctly
734 int len = TYPE_LENGTH (value_type);
735 if (DEPRECATED_STACK_ALIGN_P ())
736 /* NOTE: cagney/2003-03-22: Should rely on frame align, rather
737 than stack align to force the alignment of the stack. */
738 len = DEPRECATED_STACK_ALIGN (len);
739 if (INNER_THAN (1, 2))
741 /* Stack grows downward. Align STRUCT_ADDR and SP after
742 making space for the return value. */
744 if (gdbarch_frame_align_p (current_gdbarch))
745 sp = gdbarch_frame_align (current_gdbarch, sp);
750 /* Stack grows upward. Align the frame, allocate space, and
751 then again, re-align the frame??? */
752 if (gdbarch_frame_align_p (current_gdbarch))
753 sp = gdbarch_frame_align (current_gdbarch, sp);
756 if (gdbarch_frame_align_p (current_gdbarch))
757 sp = gdbarch_frame_align (current_gdbarch, sp);
761 /* Create the dummy stack frame. Pass in the call dummy address as,
762 presumably, the ABI code knows where, in the call dummy, the
763 return address should be pointed. */
764 if (gdbarch_push_dummy_call_p (current_gdbarch))
765 /* When there is no push_dummy_call method, should this code
766 simply error out. That would the implementation of this method
767 for all ABIs (which is probably a good thing). */
768 sp = gdbarch_push_dummy_call (current_gdbarch, funaddr, current_regcache,
769 bp_addr, nargs, args, sp, struct_return,
771 else if (DEPRECATED_PUSH_ARGUMENTS_P ())
772 /* Keep old targets working. */
773 sp = DEPRECATED_PUSH_ARGUMENTS (nargs, args, sp, struct_return,
776 sp = legacy_push_arguments (nargs, args, sp, struct_return, struct_addr);
778 if (DEPRECATED_PUSH_RETURN_ADDRESS_P ())
779 /* for targets that use no CALL_DUMMY */
780 /* There are a number of targets now which actually don't write
781 any CALL_DUMMY instructions into the target, but instead just
782 save the machine state, push the arguments, and jump directly
783 to the callee function. Since this doesn't actually involve
784 executing a JSR/BSR instruction, the return address must be set
785 up by hand, either by pushing onto the stack or copying into a
786 return-address register as appropriate. Formerly this has been
787 done in PUSH_ARGUMENTS, but that's overloading its
788 functionality a bit, so I'm making it explicit to do it here. */
789 /* NOTE: cagney/2003-04-22: The first parameter ("real_pc") has
790 been replaced with zero, it turns out that no implementation
791 used that parameter. This occured because the value being
792 supplied - the address of the called function's entry point
793 instead of the address of the breakpoint that the called
794 function should return to - wasn't useful. */
795 sp = DEPRECATED_PUSH_RETURN_ADDRESS (0, sp);
797 /* NOTE: cagney/2003-03-23: Diable this code when there is a
798 push_dummy_call() method. Since that method will have already
799 handled any alignment issues, the code below is entirely
801 if (!gdbarch_push_dummy_call_p (current_gdbarch)
802 && DEPRECATED_STACK_ALIGN_P () && !INNER_THAN (1, 2))
804 /* If stack grows up, we must leave a hole at the bottom, note
805 that sp already has been advanced for the arguments! */
806 sp = DEPRECATED_STACK_ALIGN (sp);
809 /* Store the address at which the structure is supposed to be
811 /* NOTE: 2003-03-24: Since PUSH_ARGUMENTS can (and typically does)
812 store the struct return address, this call is entirely redundant. */
813 if (struct_return && DEPRECATED_STORE_STRUCT_RETURN_P ())
814 DEPRECATED_STORE_STRUCT_RETURN (struct_addr, sp);
816 /* Write the stack pointer. This is here because the statements
817 above might fool with it. On SPARC, this write also stores the
818 register window into the right place in the new stack frame,
819 which otherwise wouldn't happen (see store_inferior_registers in
821 /* NOTE: cagney/2003-03-23: Since the architecture method
822 push_dummy_call() should have already stored the stack pointer
823 (as part of creating the fake call frame), and none of the code
824 following that call adjusts the stack-pointer value, the below
825 call is entirely redundant. */
826 if (DEPRECATED_DUMMY_WRITE_SP_P ())
827 DEPRECATED_DUMMY_WRITE_SP (sp);
829 if (gdbarch_unwind_dummy_id_p (current_gdbarch))
831 /* Sanity. The exact same SP value is returned by
832 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
833 unwind_dummy_id to form the frame ID's stack address. */
834 generic_save_dummy_frame_tos (sp);
836 else if (DEPRECATED_SAVE_DUMMY_FRAME_TOS_P ())
837 DEPRECATED_SAVE_DUMMY_FRAME_TOS (sp);
839 /* Now proceed, having reached the desired place. */
840 clear_proceed_status ();
842 /* Create a momentary breakpoint at the return address of the
843 inferior. That way it breaks when it returns. */
846 struct breakpoint *bpt;
847 struct symtab_and_line sal;
848 struct frame_id frame;
849 init_sal (&sal); /* initialize to zeroes */
851 sal.section = find_pc_overlay (sal.pc);
852 /* Set up a frame ID for the dummy frame so we can pass it to
853 set_momentary_breakpoint. We need to give the breakpoint a
854 frame ID so that the breakpoint code can correctly re-identify
855 the dummy breakpoint. */
856 if (gdbarch_unwind_dummy_id_p (current_gdbarch))
858 /* Sanity. The exact same SP value is returned by
859 PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
860 unwind_dummy_id to form the frame ID's stack address. */
861 frame = frame_id_build (sp, sal.pc);
865 /* The assumption here is that push_dummy_call() returned the
866 stack part of the frame ID. Unfortunately, many older
867 architectures were, via a convoluted mess, relying on the
868 poorly defined and greatly overloaded
869 DEPRECATED_TARGET_READ_FP or DEPRECATED_FP_REGNUM to supply
871 if (DEPRECATED_TARGET_READ_FP_P ())
872 frame = frame_id_build (DEPRECATED_TARGET_READ_FP (), sal.pc);
873 else if (DEPRECATED_FP_REGNUM >= 0)
874 frame = frame_id_build (read_register (DEPRECATED_FP_REGNUM), sal.pc);
876 frame = frame_id_build (sp, sal.pc);
878 bpt = set_momentary_breakpoint (sal, frame, bp_call_dummy);
879 bpt->disposition = disp_del;
882 /* Execute a "stack dummy", a piece of code stored in the stack by
883 the debugger to be executed in the inferior.
885 The dummy's frame is automatically popped whenever that break is
886 hit. If that is the first time the program stops,
887 call_function_by_hand returns to its caller with that frame
888 already gone and sets RC to 0.
890 Otherwise, set RC to a non-zero value. If the called function
891 receives a random signal, we do not allow the user to continue
892 executing it as this may not work. The dummy frame is poped and
893 we return 1. If we hit a breakpoint, we leave the frame in place
894 and return 2 (the frame will eventually be popped when we do hit
895 the dummy end breakpoint). */
898 struct cleanup *old_cleanups = make_cleanup (null_cleanup, 0);
901 /* If all error()s out of proceed ended up calling normal_stop
902 (and perhaps they should; it already does in the special case
903 of error out of resume()), then we wouldn't need this. */
904 make_cleanup (breakpoint_auto_delete_contents, &stop_bpstat);
906 disable_watchpoints_before_interactive_call_start ();
907 proceed_to_finish = 1; /* We want stop_registers, please... */
909 if (target_can_async_p ())
910 saved_async = target_async_mask (0);
912 proceed (real_pc, TARGET_SIGNAL_0, 0);
915 target_async_mask (saved_async);
917 enable_watchpoints_after_interactive_call_stop ();
919 discard_cleanups (old_cleanups);
922 if (stopped_by_random_signal || !stop_stack_dummy)
924 /* Find the name of the function we're about to complain about. */
925 const char *name = NULL;
927 struct symbol *symbol = find_pc_function (funaddr);
929 name = SYMBOL_PRINT_NAME (symbol);
932 /* Try the minimal symbols. */
933 struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
935 name = SYMBOL_PRINT_NAME (msymbol);
939 /* Can't use a cleanup here. It is discarded, instead use
941 char *tmp = xstrprintf ("at %s", local_hex_string (funaddr));
942 char *a = alloca (strlen (tmp) + 1);
948 if (stopped_by_random_signal)
950 /* We stopped inside the FUNCTION because of a random
951 signal. Further execution of the FUNCTION is not
954 if (unwind_on_signal_p)
956 /* The user wants the context restored. */
958 /* We must get back to the frame we were before the
960 frame_pop (get_current_frame ());
962 /* FIXME: Insert a bunch of wrap_here; name can be very
963 long if it's a C++ name with arguments and stuff. */
965 The program being debugged was signaled while in a function called from GDB.\n\
966 GDB has restored the context to what it was before the call.\n\
967 To change this behavior use \"set unwindonsignal off\"\n\
968 Evaluation of the expression containing the function (%s) will be abandoned.",
973 /* The user wants to stay in the frame where we stopped
975 /* If we restored the inferior status (via the cleanup),
976 we would print a spurious error message (Unable to
977 restore previously selected frame), would write the
978 registers from the inf_status (which is wrong), and
979 would do other wrong things. */
980 discard_cleanups (inf_status_cleanup);
981 discard_inferior_status (inf_status);
982 /* FIXME: Insert a bunch of wrap_here; name can be very
983 long if it's a C++ name with arguments and stuff. */
985 The program being debugged was signaled while in a function called from GDB.\n\
986 GDB remains in the frame where the signal was received.\n\
987 To change this behavior use \"set unwindonsignal on\"\n\
988 Evaluation of the expression containing the function (%s) will be abandoned.",
993 if (!stop_stack_dummy)
995 /* We hit a breakpoint inside the FUNCTION. */
996 /* If we restored the inferior status (via the cleanup), we
997 would print a spurious error message (Unable to restore
998 previously selected frame), would write the registers
999 from the inf_status (which is wrong), and would do other
1001 discard_cleanups (inf_status_cleanup);
1002 discard_inferior_status (inf_status);
1003 /* The following error message used to say "The expression
1004 which contained the function call has been discarded."
1005 It is a hard concept to explain in a few words. Ideally,
1006 GDB would be able to resume evaluation of the expression
1007 when the function finally is done executing. Perhaps
1008 someday this will be implemented (it would not be easy). */
1009 /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
1010 a C++ name with arguments and stuff. */
1012 The program being debugged stopped while in a function called from GDB.\n\
1013 When the function (%s) is done executing, GDB will silently\n\
1014 stop (instead of continuing to evaluate the expression containing\n\
1015 the function call).", name);
1018 /* The above code errors out, so ... */
1019 internal_error (__FILE__, __LINE__, "... should not be here");
1022 /* If we get here the called FUNCTION run to completion. */
1024 /* On normal return, the stack dummy has been popped already. */
1025 regcache_cpy_no_passthrough (retbuf, stop_registers);
1027 /* Restore the inferior status, via its cleanup. At this stage,
1028 leave the RETBUF alone. */
1029 do_cleanups (inf_status_cleanup);
1031 /* Figure out the value returned by the function. */
1034 /* NOTE: cagney/2003-09-27: This assumes that PUSH_DUMMY_CALL
1035 has correctly stored STRUCT_ADDR in the target. In the past
1036 that hasn't been the case, the old MIPS PUSH_ARGUMENTS
1037 (PUSH_DUMMY_CALL precursor) would silently move the location
1038 of the struct return value making STRUCT_ADDR bogus. If
1039 you're seeing problems with values being returned using the
1040 "struct return convention", check that PUSH_DUMMY_CALL isn't
1042 struct value *retval = value_at (value_type, struct_addr, NULL);
1043 do_cleanups (retbuf_cleanup);
1048 /* The non-register case was handled above. */
1049 struct value *retval = register_value_being_returned (value_type,
1051 do_cleanups (retbuf_cleanup);
1056 void _initialize_infcall (void);
1059 _initialize_infcall (void)
1061 add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure,
1062 &coerce_float_to_double_p, "\
1063 Set coercion of floats to doubles when calling functions\n\
1064 Variables of type float should generally be converted to doubles before\n\
1065 calling an unprototyped function, and left alone when calling a prototyped\n\
1066 function. However, some older debug info formats do not provide enough\n\
1067 information to determine that a function is prototyped. If this flag is\n\
1068 set, GDB will perform the conversion for a function it considers\n\
1070 The default is to perform the conversion.\n", "\
1071 Show coercion of floats to doubles when calling functions\n\
1072 Variables of type float should generally be converted to doubles before\n\
1073 calling an unprototyped function, and left alone when calling a prototyped\n\
1074 function. However, some older debug info formats do not provide enough\n\
1075 information to determine that a function is prototyped. If this flag is\n\
1076 set, GDB will perform the conversion for a function it considers\n\
1078 The default is to perform the conversion.\n",
1079 NULL, NULL, &setlist, &showlist);
1081 add_setshow_boolean_cmd ("unwindonsignal", no_class,
1082 &unwind_on_signal_p, "\
1083 Set unwinding of stack if a signal is received while in a call dummy.\n\
1084 The unwindonsignal lets the user determine what gdb should do if a signal\n\
1085 is received while in a function called from gdb (call dummy). If set, gdb\n\
1086 unwinds the stack and restore the context to what as it was before the call.\n\
1087 The default is to stop in the frame where the signal was received.", "\
1088 Show unwinding of stack if a signal is received while in a call dummy.\n\
1089 The unwindonsignal lets the user determine what gdb should do if a signal\n\
1090 is received while in a function called from gdb (call dummy). If set, gdb\n\
1091 unwinds the stack and restore the context to what as it was before the call.\n\
1092 The default is to stop in the frame where the signal was received.",
1093 NULL, NULL, &setlist, &showlist);