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[/] [openrisc/] [trunk/] [gnu-src/] [gdb-7.2/] [gdb/] [infcall.c] - Blame information for rev 476

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1 330 jeremybenn
/* Perform an inferior function call, for GDB, the GNU debugger.
2
 
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, 2010 Free Software Foundation, Inc.
6
 
7
   This file is part of GDB.
8
 
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.
13
 
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.
18
 
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/>.  */
21
 
22
#include "defs.h"
23
#include "breakpoint.h"
24
#include "tracepoint.h"
25
#include "target.h"
26
#include "regcache.h"
27
#include "inferior.h"
28
#include "gdb_assert.h"
29
#include "block.h"
30
#include "gdbcore.h"
31
#include "language.h"
32
#include "objfiles.h"
33
#include "gdbcmd.h"
34
#include "command.h"
35
#include "gdb_string.h"
36
#include "infcall.h"
37
#include "dummy-frame.h"
38
#include "ada-lang.h"
39
#include "gdbthread.h"
40
#include "exceptions.h"
41
 
42
/* If we can't find a function's name from its address,
43
   we print this instead.  */
44
#define RAW_FUNCTION_ADDRESS_FORMAT "at 0x%s"
45
#define RAW_FUNCTION_ADDRESS_SIZE (sizeof (RAW_FUNCTION_ADDRESS_FORMAT) \
46
                                   + 2 * sizeof (CORE_ADDR))
47
 
48
/* NOTE: cagney/2003-04-16: What's the future of this code?
49
 
50
   GDB needs an asynchronous expression evaluator, that means an
51
   asynchronous inferior function call implementation, and that in
52
   turn means restructuring the code so that it is event driven.  */
53
 
54
/* How you should pass arguments to a function depends on whether it
55
   was defined in K&R style or prototype style.  If you define a
56
   function using the K&R syntax that takes a `float' argument, then
57
   callers must pass that argument as a `double'.  If you define the
58
   function using the prototype syntax, then you must pass the
59
   argument as a `float', with no promotion.
60
 
61
   Unfortunately, on certain older platforms, the debug info doesn't
62
   indicate reliably how each function was defined.  A function type's
63
   TYPE_FLAG_PROTOTYPED flag may be clear, even if the function was
64
   defined in prototype style.  When calling a function whose
65
   TYPE_FLAG_PROTOTYPED flag is clear, GDB consults this flag to
66
   decide what to do.
67
 
68
   For modern targets, it is proper to assume that, if the prototype
69
   flag is clear, that can be trusted: `float' arguments should be
70
   promoted to `double'.  For some older targets, if the prototype
71
   flag is clear, that doesn't tell us anything.  The default is to
72
   trust the debug information; the user can override this behavior
73
   with "set coerce-float-to-double 0".  */
74
 
75
static int coerce_float_to_double_p = 1;
76
static void
77
show_coerce_float_to_double_p (struct ui_file *file, int from_tty,
78
                               struct cmd_list_element *c, const char *value)
79
{
80
  fprintf_filtered (file, _("\
81
Coercion of floats to doubles when calling functions is %s.\n"),
82
                    value);
83
}
84
 
85
/* This boolean tells what gdb should do if a signal is received while
86
   in a function called from gdb (call dummy).  If set, gdb unwinds
87
   the stack and restore the context to what as it was before the
88
   call.
89
 
90
   The default is to stop in the frame where the signal was received. */
91
 
92
int unwind_on_signal_p = 0;
93
static void
94
show_unwind_on_signal_p (struct ui_file *file, int from_tty,
95
                         struct cmd_list_element *c, const char *value)
96
{
97
  fprintf_filtered (file, _("\
98
Unwinding of stack if a signal is received while in a call dummy is %s.\n"),
99
                    value);
100
}
101
 
102
/* This boolean tells what gdb should do if a std::terminate call is
103
   made while in a function called from gdb (call dummy).
104
   As the confines of a single dummy stack prohibit out-of-frame
105
   handlers from handling a raised exception, and as out-of-frame
106
   handlers are common in C++, this can lead to no handler being found
107
   by the unwinder, and a std::terminate call.  This is a false positive.
108
   If set, gdb unwinds the stack and restores the context to what it
109
   was before the call.
110
 
111
   The default is to unwind the frame if a std::terminate call is
112
   made.  */
113
 
114
static int unwind_on_terminating_exception_p = 1;
115
 
116
static void
117
show_unwind_on_terminating_exception_p (struct ui_file *file, int from_tty,
118
                                        struct cmd_list_element *c,
119
                                        const char *value)
120
 
121
{
122
  fprintf_filtered (file, _("\
123
Unwind stack if a C++ exception is unhandled while in a call dummy is %s.\n"),
124
                    value);
125
}
126
 
127
/* Perform the standard coercions that are specified
128
   for arguments to be passed to C or Ada functions.
129
 
130
   If PARAM_TYPE is non-NULL, it is the expected parameter type.
131
   IS_PROTOTYPED is non-zero if the function declaration is prototyped.
132
   SP is the stack pointer were additional data can be pushed (updating
133
   its value as needed).  */
134
 
135
static struct value *
136
value_arg_coerce (struct gdbarch *gdbarch, struct value *arg,
137
                  struct type *param_type, int is_prototyped, CORE_ADDR *sp)
138
{
139
  const struct builtin_type *builtin = builtin_type (gdbarch);
140
  struct type *arg_type = check_typedef (value_type (arg));
141
  struct type *type
142
    = param_type ? check_typedef (param_type) : arg_type;
143
 
144
  /* Perform any Ada-specific coercion first.  */
145
  if (current_language->la_language == language_ada)
146
    arg = ada_convert_actual (arg, type, gdbarch, sp);
147
 
148
  /* Force the value to the target if we will need its address.  At
149
     this point, we could allocate arguments on the stack instead of
150
     calling malloc if we knew that their addresses would not be
151
     saved by the called function.  */
152
  arg = value_coerce_to_target (arg);
153
 
154
  switch (TYPE_CODE (type))
155
    {
156
    case TYPE_CODE_REF:
157
      {
158
        struct value *new_value;
159
 
160
        if (TYPE_CODE (arg_type) == TYPE_CODE_REF)
161
          return value_cast_pointers (type, arg);
162
 
163
        /* Cast the value to the reference's target type, and then
164
           convert it back to a reference.  This will issue an error
165
           if the value was not previously in memory - in some cases
166
           we should clearly be allowing this, but how?  */
167
        new_value = value_cast (TYPE_TARGET_TYPE (type), arg);
168
        new_value = value_ref (new_value);
169
        return new_value;
170
      }
171
    case TYPE_CODE_INT:
172
    case TYPE_CODE_CHAR:
173
    case TYPE_CODE_BOOL:
174
    case TYPE_CODE_ENUM:
175
      /* If we don't have a prototype, coerce to integer type if necessary.  */
176
      if (!is_prototyped)
177
        {
178
          if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int))
179
            type = builtin->builtin_int;
180
        }
181
      /* Currently all target ABIs require at least the width of an integer
182
         type for an argument.  We may have to conditionalize the following
183
         type coercion for future targets.  */
184
      if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_int))
185
        type = builtin->builtin_int;
186
      break;
187
    case TYPE_CODE_FLT:
188
      if (!is_prototyped && coerce_float_to_double_p)
189
        {
190
          if (TYPE_LENGTH (type) < TYPE_LENGTH (builtin->builtin_double))
191
            type = builtin->builtin_double;
192
          else if (TYPE_LENGTH (type) > TYPE_LENGTH (builtin->builtin_double))
193
            type = builtin->builtin_long_double;
194
        }
195
      break;
196
    case TYPE_CODE_FUNC:
197
      type = lookup_pointer_type (type);
198
      break;
199
    case TYPE_CODE_ARRAY:
200
      /* Arrays are coerced to pointers to their first element, unless
201
         they are vectors, in which case we want to leave them alone,
202
         because they are passed by value.  */
203
      if (current_language->c_style_arrays)
204
        if (!TYPE_VECTOR (type))
205
          type = lookup_pointer_type (TYPE_TARGET_TYPE (type));
206
      break;
207
    case TYPE_CODE_UNDEF:
208
    case TYPE_CODE_PTR:
209
    case TYPE_CODE_STRUCT:
210
    case TYPE_CODE_UNION:
211
    case TYPE_CODE_VOID:
212
    case TYPE_CODE_SET:
213
    case TYPE_CODE_RANGE:
214
    case TYPE_CODE_STRING:
215
    case TYPE_CODE_BITSTRING:
216
    case TYPE_CODE_ERROR:
217
    case TYPE_CODE_MEMBERPTR:
218
    case TYPE_CODE_METHODPTR:
219
    case TYPE_CODE_METHOD:
220
    case TYPE_CODE_COMPLEX:
221
    default:
222
      break;
223
    }
224
 
225
  return value_cast (type, arg);
226
}
227
 
228
/* Determine a function's address and its return type from its value.
229
   Calls error() if the function is not valid for calling.  */
230
 
231
CORE_ADDR
232
find_function_addr (struct value *function, struct type **retval_type)
233
{
234
  struct type *ftype = check_typedef (value_type (function));
235
  struct gdbarch *gdbarch = get_type_arch (ftype);
236
  enum type_code code = TYPE_CODE (ftype);
237
  struct type *value_type = NULL;
238
  CORE_ADDR funaddr;
239
 
240
  /* If it's a member function, just look at the function
241
     part of it.  */
242
 
243
  /* Determine address to call.  */
244
  if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
245
    {
246
      funaddr = value_address (function);
247
      value_type = TYPE_TARGET_TYPE (ftype);
248
    }
249
  else if (code == TYPE_CODE_PTR)
250
    {
251
      funaddr = value_as_address (function);
252
      ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
253
      if (TYPE_CODE (ftype) == TYPE_CODE_FUNC
254
          || TYPE_CODE (ftype) == TYPE_CODE_METHOD)
255
        {
256
          funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
257
                                                        &current_target);
258
          value_type = TYPE_TARGET_TYPE (ftype);
259
        }
260
    }
261
  else if (code == TYPE_CODE_INT)
262
    {
263
      /* Handle the case of functions lacking debugging info.
264
         Their values are characters since their addresses are char */
265
      if (TYPE_LENGTH (ftype) == 1)
266
        funaddr = value_as_address (value_addr (function));
267
      else
268
        {
269
          /* Handle function descriptors lacking debug info.  */
270
          int found_descriptor = 0;
271
 
272
          funaddr = 0;   /* pacify "gcc -Werror" */
273
          if (VALUE_LVAL (function) == lval_memory)
274
            {
275
              CORE_ADDR nfunaddr;
276
 
277
              funaddr = value_as_address (value_addr (function));
278
              nfunaddr = funaddr;
279
              funaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funaddr,
280
                                                            &current_target);
281
              if (funaddr != nfunaddr)
282
                found_descriptor = 1;
283
            }
284
          if (!found_descriptor)
285
            /* Handle integer used as address of a function.  */
286
            funaddr = (CORE_ADDR) value_as_long (function);
287
        }
288
    }
289
  else
290
    error (_("Invalid data type for function to be called."));
291
 
292
  if (retval_type != NULL)
293
    *retval_type = value_type;
294
  return funaddr + gdbarch_deprecated_function_start_offset (gdbarch);
295
}
296
 
297
/* For CALL_DUMMY_ON_STACK, push a breakpoint sequence that the called
298
   function returns to.  */
299
 
300
static CORE_ADDR
301
push_dummy_code (struct gdbarch *gdbarch,
302
                 CORE_ADDR sp, CORE_ADDR funaddr,
303
                 struct value **args, int nargs,
304
                 struct type *value_type,
305
                 CORE_ADDR *real_pc, CORE_ADDR *bp_addr,
306
                 struct regcache *regcache)
307
{
308
  gdb_assert (gdbarch_push_dummy_code_p (gdbarch));
309
 
310
  return gdbarch_push_dummy_code (gdbarch, sp, funaddr,
311
                                  args, nargs, value_type, real_pc, bp_addr,
312
                                  regcache);
313
}
314
 
315
/* Fetch the name of the function at FUNADDR.
316
   This is used in printing an error message for call_function_by_hand.
317
   BUF is used to print FUNADDR in hex if the function name cannot be
318
   determined.  It must be large enough to hold formatted result of
319
   RAW_FUNCTION_ADDRESS_FORMAT.  */
320
 
321
static const char *
322
get_function_name (CORE_ADDR funaddr, char *buf, int buf_size)
323
{
324
  {
325
    struct symbol *symbol = find_pc_function (funaddr);
326
 
327
    if (symbol)
328
      return SYMBOL_PRINT_NAME (symbol);
329
  }
330
 
331
  {
332
    /* Try the minimal symbols.  */
333
    struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (funaddr);
334
 
335
    if (msymbol)
336
      return SYMBOL_PRINT_NAME (msymbol);
337
  }
338
 
339
  {
340
    char *tmp = xstrprintf (_(RAW_FUNCTION_ADDRESS_FORMAT),
341
                            hex_string (funaddr));
342
 
343
    gdb_assert (strlen (tmp) + 1 <= buf_size);
344
    strcpy (buf, tmp);
345
    xfree (tmp);
346
    return buf;
347
  }
348
}
349
 
350
/* Subroutine of call_function_by_hand to simplify it.
351
   Start up the inferior and wait for it to stop.
352
   Return the exception if there's an error, or an exception with
353
   reason >= 0 if there's no error.
354
 
355
   This is done inside a TRY_CATCH so the caller needn't worry about
356
   thrown errors.  The caller should rethrow if there's an error.  */
357
 
358
static struct gdb_exception
359
run_inferior_call (struct thread_info *call_thread, CORE_ADDR real_pc)
360
{
361
  volatile struct gdb_exception e;
362
  int saved_async = 0;
363
  int saved_in_infcall = call_thread->in_infcall;
364
  ptid_t call_thread_ptid = call_thread->ptid;
365
  char *saved_target_shortname = xstrdup (target_shortname);
366
 
367
  call_thread->in_infcall = 1;
368
 
369
  clear_proceed_status ();
370
 
371
  disable_watchpoints_before_interactive_call_start ();
372
  call_thread->proceed_to_finish = 1; /* We want stop_registers, please... */
373
 
374
  if (target_can_async_p ())
375
    saved_async = target_async_mask (0);
376
 
377
  TRY_CATCH (e, RETURN_MASK_ALL)
378
    proceed (real_pc, TARGET_SIGNAL_0, 0);
379
 
380
  /* At this point the current thread may have changed.  Refresh
381
     CALL_THREAD as it could be invalid if its thread has exited.  */
382
  call_thread = find_thread_ptid (call_thread_ptid);
383
 
384
  /* Don't restore the async mask if the target has changed,
385
     saved_async is for the original target.  */
386
  if (saved_async
387
      && strcmp (saved_target_shortname, target_shortname) == 0)
388
    target_async_mask (saved_async);
389
 
390
  enable_watchpoints_after_interactive_call_stop ();
391
 
392
  /* Call breakpoint_auto_delete on the current contents of the bpstat
393
     of inferior call thread.
394
     If all error()s out of proceed ended up calling normal_stop
395
     (and perhaps they should; it already does in the special case
396
     of error out of resume()), then we wouldn't need this.  */
397
  if (e.reason < 0)
398
    {
399
      if (call_thread != NULL)
400
        breakpoint_auto_delete (call_thread->stop_bpstat);
401
    }
402
 
403
  if (call_thread != NULL)
404
    call_thread->in_infcall = saved_in_infcall;
405
 
406
  xfree (saved_target_shortname);
407
 
408
  return e;
409
}
410
 
411
/* A cleanup function that calls delete_std_terminate_breakpoint.  */
412
static void
413
cleanup_delete_std_terminate_breakpoint (void *ignore)
414
{
415
  delete_std_terminate_breakpoint ();
416
}
417
 
418
/* All this stuff with a dummy frame may seem unnecessarily complicated
419
   (why not just save registers in GDB?).  The purpose of pushing a dummy
420
   frame which looks just like a real frame is so that if you call a
421
   function and then hit a breakpoint (get a signal, etc), "backtrace"
422
   will look right.  Whether the backtrace needs to actually show the
423
   stack at the time the inferior function was called is debatable, but
424
   it certainly needs to not display garbage.  So if you are contemplating
425
   making dummy frames be different from normal frames, consider that.  */
426
 
427
/* Perform a function call in the inferior.
428
   ARGS is a vector of values of arguments (NARGS of them).
429
   FUNCTION is a value, the function to be called.
430
   Returns a value representing what the function returned.
431
   May fail to return, if a breakpoint or signal is hit
432
   during the execution of the function.
433
 
434
   ARGS is modified to contain coerced values. */
435
 
436
struct value *
437
call_function_by_hand (struct value *function, int nargs, struct value **args)
438
{
439
  CORE_ADDR sp;
440
  struct type *values_type, *target_values_type;
441
  unsigned char struct_return = 0, lang_struct_return = 0;
442
  CORE_ADDR struct_addr = 0;
443
  struct inferior_status *inf_status;
444
  struct cleanup *inf_status_cleanup;
445
  struct inferior_thread_state *caller_state;
446
  struct cleanup *caller_state_cleanup;
447
  CORE_ADDR funaddr;
448
  CORE_ADDR real_pc;
449
  struct type *ftype = check_typedef (value_type (function));
450
  CORE_ADDR bp_addr;
451
  struct frame_id dummy_id;
452
  struct cleanup *args_cleanup;
453
  struct frame_info *frame;
454
  struct gdbarch *gdbarch;
455
  struct cleanup *terminate_bp_cleanup;
456
  ptid_t call_thread_ptid;
457
  struct gdb_exception e;
458
  char name_buf[RAW_FUNCTION_ADDRESS_SIZE];
459
 
460
  if (TYPE_CODE (ftype) == TYPE_CODE_PTR)
461
    ftype = check_typedef (TYPE_TARGET_TYPE (ftype));
462
 
463
  if (!target_has_execution)
464
    noprocess ();
465
 
466
  if (get_traceframe_number () >= 0)
467
    error (_("May not call functions while looking at trace frames."));
468
 
469
  frame = get_current_frame ();
470
  gdbarch = get_frame_arch (frame);
471
 
472
  if (!gdbarch_push_dummy_call_p (gdbarch))
473
    error (_("This target does not support function calls."));
474
 
475
  /* A cleanup for the inferior status.
476
     This is only needed while we're preparing the inferior function call.  */
477
  inf_status = save_inferior_status ();
478
  inf_status_cleanup = make_cleanup_restore_inferior_status (inf_status);
479
 
480
  /* Save the caller's registers and other state associated with the
481
     inferior itself so that they can be restored once the
482
     callee returns.  To allow nested calls the registers are (further
483
     down) pushed onto a dummy frame stack.  Include a cleanup (which
484
     is tossed once the regcache has been pushed).  */
485
  caller_state = save_inferior_thread_state ();
486
  caller_state_cleanup = make_cleanup_restore_inferior_thread_state (caller_state);
487
 
488
  /* Ensure that the initial SP is correctly aligned.  */
489
  {
490
    CORE_ADDR old_sp = get_frame_sp (frame);
491
 
492
    if (gdbarch_frame_align_p (gdbarch))
493
      {
494
        sp = gdbarch_frame_align (gdbarch, old_sp);
495
        /* NOTE: cagney/2003-08-13: Skip the "red zone".  For some
496
           ABIs, a function can use memory beyond the inner most stack
497
           address.  AMD64 called that region the "red zone".  Skip at
498
           least the "red zone" size before allocating any space on
499
           the stack.  */
500
        if (gdbarch_inner_than (gdbarch, 1, 2))
501
          sp -= gdbarch_frame_red_zone_size (gdbarch);
502
        else
503
          sp += gdbarch_frame_red_zone_size (gdbarch);
504
        /* Still aligned?  */
505
        gdb_assert (sp == gdbarch_frame_align (gdbarch, sp));
506
        /* NOTE: cagney/2002-09-18:
507
 
508
           On a RISC architecture, a void parameterless generic dummy
509
           frame (i.e., no parameters, no result) typically does not
510
           need to push anything the stack and hence can leave SP and
511
           FP.  Similarly, a frameless (possibly leaf) function does
512
           not push anything on the stack and, hence, that too can
513
           leave FP and SP unchanged.  As a consequence, a sequence of
514
           void parameterless generic dummy frame calls to frameless
515
           functions will create a sequence of effectively identical
516
           frames (SP, FP and TOS and PC the same).  This, not
517
           suprisingly, results in what appears to be a stack in an
518
           infinite loop --- when GDB tries to find a generic dummy
519
           frame on the internal dummy frame stack, it will always
520
           find the first one.
521
 
522
           To avoid this problem, the code below always grows the
523
           stack.  That way, two dummy frames can never be identical.
524
           It does burn a few bytes of stack but that is a small price
525
           to pay :-).  */
526
        if (sp == old_sp)
527
          {
528
            if (gdbarch_inner_than (gdbarch, 1, 2))
529
              /* Stack grows down.  */
530
              sp = gdbarch_frame_align (gdbarch, old_sp - 1);
531
            else
532
              /* Stack grows up.  */
533
              sp = gdbarch_frame_align (gdbarch, old_sp + 1);
534
          }
535
        /* SP may have underflown address zero here from OLD_SP.  Memory access
536
           functions will probably fail in such case but that is a target's
537
           problem.  */
538
      }
539
    else
540
      /* FIXME: cagney/2002-09-18: Hey, you loose!
541
 
542
         Who knows how badly aligned the SP is!
543
 
544
         If the generic dummy frame ends up empty (because nothing is
545
         pushed) GDB won't be able to correctly perform back traces.
546
         If a target is having trouble with backtraces, first thing to
547
         do is add FRAME_ALIGN() to the architecture vector. If that
548
         fails, try dummy_id().
549
 
550
         If the ABI specifies a "Red Zone" (see the doco) the code
551
         below will quietly trash it.  */
552
      sp = old_sp;
553
  }
554
 
555
  funaddr = find_function_addr (function, &values_type);
556
  if (!values_type)
557
    values_type = builtin_type (gdbarch)->builtin_int;
558
 
559
  CHECK_TYPEDEF (values_type);
560
 
561
  /* Are we returning a value using a structure return (passing a
562
     hidden argument pointing to storage) or a normal value return?
563
     There are two cases: language-mandated structure return and
564
     target ABI structure return.  The variable STRUCT_RETURN only
565
     describes the latter.  The language version is handled by passing
566
     the return location as the first parameter to the function,
567
     even preceding "this".  This is different from the target
568
     ABI version, which is target-specific; for instance, on ia64
569
     the first argument is passed in out0 but the hidden structure
570
     return pointer would normally be passed in r8.  */
571
 
572
  if (language_pass_by_reference (values_type))
573
    {
574
      lang_struct_return = 1;
575
 
576
      /* Tell the target specific argument pushing routine not to
577
         expect a value.  */
578
      target_values_type = builtin_type (gdbarch)->builtin_void;
579
    }
580
  else
581
    {
582
      struct_return = using_struct_return (gdbarch,
583
                                           value_type (function), values_type);
584
      target_values_type = values_type;
585
    }
586
 
587
  /* Determine the location of the breakpoint (and possibly other
588
     stuff) that the called function will return to.  The SPARC, for a
589
     function returning a structure or union, needs to make space for
590
     not just the breakpoint but also an extra word containing the
591
     size (?) of the structure being passed.  */
592
 
593
  /* The actual breakpoint (at BP_ADDR) is inserted separatly so there
594
     is no need to write that out.  */
595
 
596
  switch (gdbarch_call_dummy_location (gdbarch))
597
    {
598
    case ON_STACK:
599
      sp = push_dummy_code (gdbarch, sp, funaddr,
600
                                args, nargs, target_values_type,
601
                                &real_pc, &bp_addr, get_current_regcache ());
602
      break;
603
    case AT_ENTRY_POINT:
604
      {
605
        CORE_ADDR dummy_addr;
606
 
607
        real_pc = funaddr;
608
        dummy_addr = entry_point_address ();
609
        /* A call dummy always consists of just a single breakpoint, so
610
           its address is the same as the address of the dummy.  */
611
        bp_addr = dummy_addr;
612
        break;
613
      }
614
    case AT_SYMBOL:
615
      /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose
616
         address is the location where the breakpoint should be
617
         placed.  Once all targets are using the overhauled frame code
618
         this can be deleted - ON_STACK is a better option.  */
619
      {
620
        struct minimal_symbol *sym;
621
        CORE_ADDR dummy_addr;
622
 
623
        sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL, NULL);
624
        real_pc = funaddr;
625
        if (sym)
626
          {
627
            dummy_addr = SYMBOL_VALUE_ADDRESS (sym);
628
            /* Make certain that the address points at real code, and not
629
               a function descriptor.  */
630
            dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch,
631
                                                             dummy_addr,
632
                                                             &current_target);
633
          }
634
        else
635
          dummy_addr = entry_point_address ();
636
        /* A call dummy always consists of just a single breakpoint,
637
           so it's address is the same as the address of the dummy.  */
638
        bp_addr = dummy_addr;
639
        break;
640
      }
641
    default:
642
      internal_error (__FILE__, __LINE__, _("bad switch"));
643
    }
644
 
645
  if (nargs < TYPE_NFIELDS (ftype))
646
    error (_("Too few arguments in function call."));
647
 
648
  {
649
    int i;
650
 
651
    for (i = nargs - 1; i >= 0; i--)
652
      {
653
        int prototyped;
654
        struct type *param_type;
655
 
656
        /* FIXME drow/2002-05-31: Should just always mark methods as
657
           prototyped.  Can we respect TYPE_VARARGS?  Probably not.  */
658
        if (TYPE_CODE (ftype) == TYPE_CODE_METHOD)
659
          prototyped = 1;
660
        else if (i < TYPE_NFIELDS (ftype))
661
          prototyped = TYPE_PROTOTYPED (ftype);
662
        else
663
          prototyped = 0;
664
 
665
        if (i < TYPE_NFIELDS (ftype))
666
          param_type = TYPE_FIELD_TYPE (ftype, i);
667
        else
668
          param_type = NULL;
669
 
670
        args[i] = value_arg_coerce (gdbarch, args[i],
671
                                    param_type, prototyped, &sp);
672
 
673
        if (param_type != NULL && language_pass_by_reference (param_type))
674
          args[i] = value_addr (args[i]);
675
      }
676
  }
677
 
678
  /* Reserve space for the return structure to be written on the
679
     stack, if necessary.  Make certain that the value is correctly
680
     aligned. */
681
 
682
  if (struct_return || lang_struct_return)
683
    {
684
      int len = TYPE_LENGTH (values_type);
685
 
686
      if (gdbarch_inner_than (gdbarch, 1, 2))
687
        {
688
          /* Stack grows downward.  Align STRUCT_ADDR and SP after
689
             making space for the return value.  */
690
          sp -= len;
691
          if (gdbarch_frame_align_p (gdbarch))
692
            sp = gdbarch_frame_align (gdbarch, sp);
693
          struct_addr = sp;
694
        }
695
      else
696
        {
697
          /* Stack grows upward.  Align the frame, allocate space, and
698
             then again, re-align the frame??? */
699
          if (gdbarch_frame_align_p (gdbarch))
700
            sp = gdbarch_frame_align (gdbarch, sp);
701
          struct_addr = sp;
702
          sp += len;
703
          if (gdbarch_frame_align_p (gdbarch))
704
            sp = gdbarch_frame_align (gdbarch, sp);
705
        }
706
    }
707
 
708
  if (lang_struct_return)
709
    {
710
      struct value **new_args;
711
 
712
      /* Add the new argument to the front of the argument list.  */
713
      new_args = xmalloc (sizeof (struct value *) * (nargs + 1));
714
      new_args[0] = value_from_pointer (lookup_pointer_type (values_type),
715
                                        struct_addr);
716
      memcpy (&new_args[1], &args[0], sizeof (struct value *) * nargs);
717
      args = new_args;
718
      nargs++;
719
      args_cleanup = make_cleanup (xfree, args);
720
    }
721
  else
722
    args_cleanup = make_cleanup (null_cleanup, NULL);
723
 
724
  /* Create the dummy stack frame.  Pass in the call dummy address as,
725
     presumably, the ABI code knows where, in the call dummy, the
726
     return address should be pointed.  */
727
  sp = gdbarch_push_dummy_call (gdbarch, function, get_current_regcache (),
728
                                bp_addr, nargs, args,
729
                                sp, struct_return, struct_addr);
730
 
731
  do_cleanups (args_cleanup);
732
 
733
  /* Set up a frame ID for the dummy frame so we can pass it to
734
     set_momentary_breakpoint.  We need to give the breakpoint a frame
735
     ID so that the breakpoint code can correctly re-identify the
736
     dummy breakpoint.  */
737
  /* Sanity.  The exact same SP value is returned by PUSH_DUMMY_CALL,
738
     saved as the dummy-frame TOS, and used by dummy_id to form
739
     the frame ID's stack address.  */
740
  dummy_id = frame_id_build (sp, bp_addr);
741
 
742
  /* Create a momentary breakpoint at the return address of the
743
     inferior.  That way it breaks when it returns.  */
744
 
745
  {
746
    struct breakpoint *bpt;
747
    struct symtab_and_line sal;
748
 
749
    init_sal (&sal);            /* initialize to zeroes */
750
    sal.pspace = current_program_space;
751
    sal.pc = bp_addr;
752
    sal.section = find_pc_overlay (sal.pc);
753
    /* Sanity.  The exact same SP value is returned by
754
       PUSH_DUMMY_CALL, saved as the dummy-frame TOS, and used by
755
       dummy_id to form the frame ID's stack address.  */
756
    bpt = set_momentary_breakpoint (gdbarch, sal, dummy_id, bp_call_dummy);
757
    bpt->disposition = disp_del;
758
  }
759
 
760
  /* Create a breakpoint in std::terminate.
761
     If a C++ exception is raised in the dummy-frame, and the
762
     exception handler is (normally, and expected to be) out-of-frame,
763
     the default C++ handler will (wrongly) be called in an inferior
764
     function call.  This is wrong, as an exception can be  normally
765
     and legally handled out-of-frame.  The confines of the dummy frame
766
     prevent the unwinder from finding the correct handler (or any
767
     handler, unless it is in-frame).  The default handler calls
768
     std::terminate.  This will kill the inferior.  Assert that
769
     terminate should never be called in an inferior function
770
     call.  Place a momentary breakpoint in the std::terminate function
771
     and if triggered in the call, rewind.  */
772
  if (unwind_on_terminating_exception_p)
773
    set_std_terminate_breakpoint ();
774
 
775
  /* Everything's ready, push all the info needed to restore the
776
     caller (and identify the dummy-frame) onto the dummy-frame
777
     stack.  */
778
  dummy_frame_push (caller_state, &dummy_id);
779
 
780
  /* Discard both inf_status and caller_state cleanups.
781
     From this point on we explicitly restore the associated state
782
     or discard it.  */
783
  discard_cleanups (inf_status_cleanup);
784
 
785
  /* Register a clean-up for unwind_on_terminating_exception_breakpoint.  */
786
  terminate_bp_cleanup = make_cleanup (cleanup_delete_std_terminate_breakpoint,
787
                                       NULL);
788
 
789
  /* - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP - SNIP -
790
     If you're looking to implement asynchronous dummy-frames, then
791
     just below is the place to chop this function in two..  */
792
 
793
  /* TP is invalid after run_inferior_call returns, so enclose this
794
     in a block so that it's only in scope during the time it's valid.  */
795
  {
796
    struct thread_info *tp = inferior_thread ();
797
 
798
    /* Save this thread's ptid, we need it later but the thread
799
       may have exited.  */
800
    call_thread_ptid = tp->ptid;
801
 
802
    /* Run the inferior until it stops.  */
803
 
804
    e = run_inferior_call (tp, real_pc);
805
  }
806
 
807
  /* Rethrow an error if we got one trying to run the inferior.  */
808
 
809
  if (e.reason < 0)
810
    {
811
      const char *name = get_function_name (funaddr,
812
                                            name_buf, sizeof (name_buf));
813
 
814
      discard_inferior_status (inf_status);
815
 
816
      /* We could discard the dummy frame here if the program exited,
817
         but it will get garbage collected the next time the program is
818
         run anyway.  */
819
 
820
      switch (e.reason)
821
        {
822
        case RETURN_ERROR:
823
          throw_error (e.error, _("\
824
%s\n\
825
An error occurred while in a function called from GDB.\n\
826
Evaluation of the expression containing the function\n\
827
(%s) will be abandoned.\n\
828
When the function is done executing, GDB will silently stop."),
829
                       e.message, name);
830
        case RETURN_QUIT:
831
        default:
832
          throw_exception (e);
833
        }
834
    }
835
 
836
  /* If the program has exited, or we stopped at a different thread,
837
     exit and inform the user.  */
838
 
839
  if (! target_has_execution)
840
    {
841
      const char *name = get_function_name (funaddr,
842
                                            name_buf, sizeof (name_buf));
843
 
844
      /* If we try to restore the inferior status,
845
         we'll crash as the inferior is no longer running.  */
846
      discard_inferior_status (inf_status);
847
 
848
      /* We could discard the dummy frame here given that the program exited,
849
         but it will get garbage collected the next time the program is
850
         run anyway.  */
851
 
852
      error (_("\
853
The program being debugged exited while in a function called from GDB.\n\
854
Evaluation of the expression containing the function\n\
855
(%s) will be abandoned."),
856
             name);
857
    }
858
 
859
  if (! ptid_equal (call_thread_ptid, inferior_ptid))
860
    {
861
      const char *name = get_function_name (funaddr,
862
                                            name_buf, sizeof (name_buf));
863
 
864
      /* We've switched threads.  This can happen if another thread gets a
865
         signal or breakpoint while our thread was running.
866
         There's no point in restoring the inferior status,
867
         we're in a different thread.  */
868
      discard_inferior_status (inf_status);
869
      /* Keep the dummy frame record, if the user switches back to the
870
         thread with the hand-call, we'll need it.  */
871
      if (stopped_by_random_signal)
872
        error (_("\
873
The program received a signal in another thread while\n\
874
making a function call from GDB.\n\
875
Evaluation of the expression containing the function\n\
876
(%s) will be abandoned.\n\
877
When the function is done executing, GDB will silently stop."),
878
               name);
879
      else
880
        error (_("\
881
The program stopped in another thread while making a function call from GDB.\n\
882
Evaluation of the expression containing the function\n\
883
(%s) will be abandoned.\n\
884
When the function is done executing, GDB will silently stop."),
885
               name);
886
    }
887
 
888
  if (stopped_by_random_signal || stop_stack_dummy != STOP_STACK_DUMMY)
889
    {
890
      const char *name = get_function_name (funaddr,
891
                                            name_buf, sizeof (name_buf));
892
 
893
      if (stopped_by_random_signal)
894
        {
895
          /* We stopped inside the FUNCTION because of a random
896
             signal.  Further execution of the FUNCTION is not
897
             allowed. */
898
 
899
          if (unwind_on_signal_p)
900
            {
901
              /* The user wants the context restored. */
902
 
903
              /* We must get back to the frame we were before the
904
                 dummy call.  */
905
              dummy_frame_pop (dummy_id);
906
 
907
              /* We also need to restore inferior status to that before the
908
                 dummy call.  */
909
              restore_inferior_status (inf_status);
910
 
911
              /* FIXME: Insert a bunch of wrap_here; name can be very
912
                 long if it's a C++ name with arguments and stuff.  */
913
              error (_("\
914
The program being debugged was signaled while in a function called from GDB.\n\
915
GDB has restored the context to what it was before the call.\n\
916
To change this behavior use \"set unwindonsignal off\".\n\
917
Evaluation of the expression containing the function\n\
918
(%s) will be abandoned."),
919
                     name);
920
            }
921
          else
922
            {
923
              /* The user wants to stay in the frame where we stopped
924
                 (default).
925
                 Discard inferior status, we're not at the same point
926
                 we started at.  */
927
              discard_inferior_status (inf_status);
928
 
929
              /* FIXME: Insert a bunch of wrap_here; name can be very
930
                 long if it's a C++ name with arguments and stuff.  */
931
              error (_("\
932
The program being debugged was signaled while in a function called from GDB.\n\
933
GDB remains in the frame where the signal was received.\n\
934
To change this behavior use \"set unwindonsignal on\".\n\
935
Evaluation of the expression containing the function\n\
936
(%s) will be abandoned.\n\
937
When the function is done executing, GDB will silently stop."),
938
                     name);
939
            }
940
        }
941
 
942
      if (stop_stack_dummy == STOP_STD_TERMINATE)
943
        {
944
          /* We must get back to the frame we were before the dummy
945
             call.  */
946
          dummy_frame_pop (dummy_id);
947
 
948
          /* We also need to restore inferior status to that before
949
             the dummy call.  */
950
          restore_inferior_status (inf_status);
951
 
952
          error (_("\
953
The program being debugged entered a std::terminate call, most likely\n\
954
caused by an unhandled C++ exception.  GDB blocked this call in order\n\
955
to prevent the program from being terminated, and has restored the\n\
956
context to its original state before the call.\n\
957
To change this behaviour use \"set unwind-on-terminating-exception off\".\n\
958
Evaluation of the expression containing the function (%s)\n\
959
will be abandoned."),
960
                 name);
961
        }
962
      else if (stop_stack_dummy == STOP_NONE)
963
        {
964
 
965
          /* We hit a breakpoint inside the FUNCTION.
966
             Keep the dummy frame, the user may want to examine its state.
967
             Discard inferior status, we're not at the same point
968
             we started at.  */
969
          discard_inferior_status (inf_status);
970
 
971
          /* The following error message used to say "The expression
972
             which contained the function call has been discarded."
973
             It is a hard concept to explain in a few words.  Ideally,
974
             GDB would be able to resume evaluation of the expression
975
             when the function finally is done executing.  Perhaps
976
             someday this will be implemented (it would not be easy).  */
977
          /* FIXME: Insert a bunch of wrap_here; name can be very long if it's
978
             a C++ name with arguments and stuff.  */
979
          error (_("\
980
The program being debugged stopped while in a function called from GDB.\n\
981
Evaluation of the expression containing the function\n\
982
(%s) will be abandoned.\n\
983
When the function is done executing, GDB will silently stop."),
984
                 name);
985
        }
986
 
987
      /* The above code errors out, so ...  */
988
      internal_error (__FILE__, __LINE__, _("... should not be here"));
989
    }
990
 
991
  do_cleanups (terminate_bp_cleanup);
992
 
993
  /* If we get here the called FUNCTION ran to completion,
994
     and the dummy frame has already been popped.  */
995
 
996
  {
997
    struct address_space *aspace = get_regcache_aspace (stop_registers);
998
    struct regcache *retbuf = regcache_xmalloc (gdbarch, aspace);
999
    struct cleanup *retbuf_cleanup = make_cleanup_regcache_xfree (retbuf);
1000
    struct value *retval = NULL;
1001
 
1002
    regcache_cpy_no_passthrough (retbuf, stop_registers);
1003
 
1004
    /* Inferior call is successful.  Restore the inferior status.
1005
       At this stage, leave the RETBUF alone.  */
1006
    restore_inferior_status (inf_status);
1007
 
1008
    /* Figure out the value returned by the function.  */
1009
 
1010
    if (lang_struct_return)
1011
      retval = value_at (values_type, struct_addr);
1012
    else if (TYPE_CODE (target_values_type) == TYPE_CODE_VOID)
1013
      {
1014
        /* If the function returns void, don't bother fetching the
1015
           return value.  */
1016
        retval = allocate_value (values_type);
1017
      }
1018
    else
1019
      {
1020
        switch (gdbarch_return_value (gdbarch, value_type (function),
1021
                                      target_values_type, NULL, NULL, NULL))
1022
          {
1023
          case RETURN_VALUE_REGISTER_CONVENTION:
1024
          case RETURN_VALUE_ABI_RETURNS_ADDRESS:
1025
          case RETURN_VALUE_ABI_PRESERVES_ADDRESS:
1026
            retval = allocate_value (values_type);
1027
            gdbarch_return_value (gdbarch, value_type (function), values_type,
1028
                                  retbuf, value_contents_raw (retval), NULL);
1029
            break;
1030
          case RETURN_VALUE_STRUCT_CONVENTION:
1031
            retval = value_at (values_type, struct_addr);
1032
            break;
1033
          }
1034
      }
1035
 
1036
    do_cleanups (retbuf_cleanup);
1037
 
1038
    gdb_assert (retval);
1039
    return retval;
1040
  }
1041
}
1042
 
1043
 
1044
/* Provide a prototype to silence -Wmissing-prototypes.  */
1045
void _initialize_infcall (void);
1046
 
1047
void
1048
_initialize_infcall (void)
1049
{
1050
  add_setshow_boolean_cmd ("coerce-float-to-double", class_obscure,
1051
                           &coerce_float_to_double_p, _("\
1052
Set coercion of floats to doubles when calling functions."), _("\
1053
Show coercion of floats to doubles when calling functions"), _("\
1054
Variables of type float should generally be converted to doubles before\n\
1055
calling an unprototyped function, and left alone when calling a prototyped\n\
1056
function.  However, some older debug info formats do not provide enough\n\
1057
information to determine that a function is prototyped.  If this flag is\n\
1058
set, GDB will perform the conversion for a function it considers\n\
1059
unprototyped.\n\
1060
The default is to perform the conversion.\n"),
1061
                           NULL,
1062
                           show_coerce_float_to_double_p,
1063
                           &setlist, &showlist);
1064
 
1065
  add_setshow_boolean_cmd ("unwindonsignal", no_class,
1066
                           &unwind_on_signal_p, _("\
1067
Set unwinding of stack if a signal is received while in a call dummy."), _("\
1068
Show unwinding of stack if a signal is received while in a call dummy."), _("\
1069
The unwindonsignal lets the user determine what gdb should do if a signal\n\
1070
is received while in a function called from gdb (call dummy).  If set, gdb\n\
1071
unwinds the stack and restore the context to what as it was before the call.\n\
1072
The default is to stop in the frame where the signal was received."),
1073
                           NULL,
1074
                           show_unwind_on_signal_p,
1075
                           &setlist, &showlist);
1076
 
1077
  add_setshow_boolean_cmd ("unwind-on-terminating-exception", no_class,
1078
                           &unwind_on_terminating_exception_p, _("\
1079
Set unwinding of stack if std::terminate is called while in call dummy."), _("\
1080
Show unwinding of stack if std::terminate() is called while in a call dummy."), _("\
1081
The unwind on terminating exception flag lets the user determine\n\
1082
what gdb should do if a std::terminate() call is made from the\n\
1083
default exception handler.  If set, gdb unwinds the stack and restores\n\
1084
the context to what it was before the call.  If unset, gdb allows the\n\
1085
std::terminate call to proceed.\n\
1086
The default is to unwind the frame."),
1087
                           NULL,
1088
                           show_unwind_on_terminating_exception_p,
1089
                           &setlist, &showlist);
1090
 
1091
}

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