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[/] [openrisc/] [trunk/] [gnu-old/] [gdb-7.1/] [gdb/] [rx-tdep.c] - Blame information for rev 853

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1 227 jeremybenn
/* Target-dependent code for the Renesas RX for GDB, the GNU debugger.
2
 
3
   Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
4
 
5
   Contributed by Red Hat, 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 "arch-utils.h"
24
#include "prologue-value.h"
25
#include "target.h"
26
#include "regcache.h"
27
#include "opcode/rx.h"
28
#include "dis-asm.h"
29
#include "gdbtypes.h"
30
#include "frame.h"
31
#include "frame-unwind.h"
32
#include "frame-base.h"
33
#include "value.h"
34
#include "gdbcore.h"
35
#include "dwarf2-frame.h"
36
 
37
#include "elf/rx.h"
38
#include "elf-bfd.h"
39
 
40
/* Certain important register numbers.  */
41
enum
42
{
43
  RX_SP_REGNUM = 0,
44
  RX_R1_REGNUM = 1,
45
  RX_R4_REGNUM = 4,
46
  RX_FP_REGNUM = 6,
47
  RX_R15_REGNUM = 15,
48
  RX_PC_REGNUM = 19,
49
  RX_NUM_REGS = 25
50
};
51
 
52
/* Architecture specific data.  */
53
struct gdbarch_tdep
54
{
55
  /* The ELF header flags specify the multilib used.  */
56
  int elf_flags;
57
};
58
 
59
/* This structure holds the results of a prologue analysis.  */
60
struct rx_prologue
61
{
62
  /* The offset from the frame base to the stack pointer --- always
63
     zero or negative.
64
 
65
     Calling this a "size" is a bit misleading, but given that the
66
     stack grows downwards, using offsets for everything keeps one
67
     from going completely sign-crazy: you never change anything's
68
     sign for an ADD instruction; always change the second operand's
69
     sign for a SUB instruction; and everything takes care of
70
     itself.  */
71
  int frame_size;
72
 
73
  /* Non-zero if this function has initialized the frame pointer from
74
     the stack pointer, zero otherwise.  */
75
  int has_frame_ptr;
76
 
77
  /* If has_frame_ptr is non-zero, this is the offset from the frame
78
     base to where the frame pointer points.  This is always zero or
79
     negative.  */
80
  int frame_ptr_offset;
81
 
82
  /* The address of the first instruction at which the frame has been
83
     set up and the arguments are where the debug info says they are
84
     --- as best as we can tell.  */
85
  CORE_ADDR prologue_end;
86
 
87
  /* reg_offset[R] is the offset from the CFA at which register R is
88
     saved, or 1 if register R has not been saved.  (Real values are
89
     always zero or negative.)  */
90
  int reg_offset[RX_NUM_REGS];
91
};
92
 
93
/* Implement the "register_name" gdbarch method.  */
94
static const char *
95
rx_register_name (struct gdbarch *gdbarch, int regnr)
96
{
97
  static const char *const reg_names[] = {
98
    "r0",
99
    "r1",
100
    "r2",
101
    "r3",
102
    "r4",
103
    "r5",
104
    "r6",
105
    "r7",
106
    "r8",
107
    "r9",
108
    "r10",
109
    "r11",
110
    "r12",
111
    "r13",
112
    "r14",
113
    "r15",
114
    "isp",
115
    "usp",
116
    "intb",
117
    "pc",
118
    "psw",
119
    "bpc",
120
    "bpsw",
121
    "vct",
122
    "fpsw"
123
  };
124
 
125
  return reg_names[regnr];
126
}
127
 
128
/* Implement the "register_type" gdbarch method.  */
129
static struct type *
130
rx_register_type (struct gdbarch *gdbarch, int reg_nr)
131
{
132
  if (reg_nr == RX_PC_REGNUM)
133
    return builtin_type (gdbarch)->builtin_func_ptr;
134
  else
135
    return builtin_type (gdbarch)->builtin_unsigned_long;
136
}
137
 
138
 
139
/* Function for finding saved registers in a 'struct pv_area'; this
140
   function is passed to pv_area_scan.
141
 
142
   If VALUE is a saved register, ADDR says it was saved at a constant
143
   offset from the frame base, and SIZE indicates that the whole
144
   register was saved, record its offset.  */
145
static void
146
check_for_saved (void *result_untyped, pv_t addr, CORE_ADDR size, pv_t value)
147
{
148
  struct rx_prologue *result = (struct rx_prologue *) result_untyped;
149
 
150
  if (value.kind == pvk_register
151
      && value.k == 0
152
      && pv_is_register (addr, RX_SP_REGNUM)
153
      && size == register_size (target_gdbarch, value.reg))
154
    result->reg_offset[value.reg] = addr.k;
155
}
156
 
157
/* Define a "handle" struct for fetching the next opcode.  */
158
struct rx_get_opcode_byte_handle
159
{
160
  CORE_ADDR pc;
161
};
162
 
163
/* Fetch a byte on behalf of the opcode decoder.  HANDLE contains
164
   the memory address of the next byte to fetch.  If successful,
165
   the address in the handle is updated and the byte fetched is
166
   returned as the value of the function.  If not successful, -1
167
   is returned.  */
168
static int
169
rx_get_opcode_byte (void *handle)
170
{
171
  struct rx_get_opcode_byte_handle *opcdata = handle;
172
  int status;
173
  gdb_byte byte;
174
 
175
  status = target_read_memory (opcdata->pc, &byte, 1);
176
  if (status == 0)
177
    {
178
      opcdata->pc += 1;
179
      return byte;
180
    }
181
  else
182
    return -1;
183
}
184
 
185
/* Analyze a prologue starting at START_PC, going no further than
186
   LIMIT_PC.  Fill in RESULT as appropriate.  */
187
static void
188
rx_analyze_prologue (CORE_ADDR start_pc,
189
                     CORE_ADDR limit_pc, struct rx_prologue *result)
190
{
191
  CORE_ADDR pc, next_pc;
192
  int rn;
193
  pv_t reg[RX_NUM_REGS];
194
  struct pv_area *stack;
195
  struct cleanup *back_to;
196
  CORE_ADDR after_last_frame_setup_insn = start_pc;
197
 
198
  memset (result, 0, sizeof (*result));
199
 
200
  for (rn = 0; rn < RX_NUM_REGS; rn++)
201
    {
202
      reg[rn] = pv_register (rn, 0);
203
      result->reg_offset[rn] = 1;
204
    }
205
 
206
  stack = make_pv_area (RX_SP_REGNUM, gdbarch_addr_bit (target_gdbarch));
207
  back_to = make_cleanup_free_pv_area (stack);
208
 
209
  /* The call instruction has saved the return address on the stack.  */
210
  reg[RX_SP_REGNUM] = pv_add_constant (reg[RX_SP_REGNUM], -4);
211
  pv_area_store (stack, reg[RX_SP_REGNUM], 4, reg[RX_PC_REGNUM]);
212
 
213
  pc = start_pc;
214
  while (pc < limit_pc)
215
    {
216
      int bytes_read;
217
      struct rx_get_opcode_byte_handle opcode_handle;
218
      RX_Opcode_Decoded opc;
219
 
220
      opcode_handle.pc = pc;
221
      bytes_read = rx_decode_opcode (pc, &opc, rx_get_opcode_byte,
222
                                     &opcode_handle);
223
      next_pc = pc + bytes_read;
224
 
225
      if (opc.id == RXO_pushm   /* pushm r1, r2 */
226
          && opc.op[1].type == RX_Operand_Register
227
          && opc.op[2].type == RX_Operand_Register)
228
        {
229
          int r1, r2;
230
          int r;
231
 
232
          r1 = opc.op[1].reg;
233
          r2 = opc.op[2].reg;
234
          for (r = r2; r >= r1; r--)
235
            {
236
              reg[RX_SP_REGNUM] = pv_add_constant (reg[RX_SP_REGNUM], -4);
237
              pv_area_store (stack, reg[RX_SP_REGNUM], 4, reg[r]);
238
            }
239
          after_last_frame_setup_insn = next_pc;
240
        }
241
      else if (opc.id == RXO_mov        /* mov.l rdst, rsrc */
242
               && opc.op[0].type == RX_Operand_Register
243
               && opc.op[1].type == RX_Operand_Register
244
               && opc.size == RX_Long)
245
        {
246
          int rdst, rsrc;
247
 
248
          rdst = opc.op[0].reg;
249
          rsrc = opc.op[1].reg;
250
          reg[rdst] = reg[rsrc];
251
          if (rdst == RX_FP_REGNUM && rsrc == RX_SP_REGNUM)
252
            after_last_frame_setup_insn = next_pc;
253
        }
254
      else if (opc.id == RXO_mov        /* mov.l rsrc, [-SP] */
255
               && opc.op[0].type == RX_Operand_Predec
256
               && opc.op[0].reg == RX_SP_REGNUM
257
               && opc.op[1].type == RX_Operand_Register
258
               && opc.size == RX_Long)
259
        {
260
          int rsrc;
261
 
262
          rsrc = opc.op[1].reg;
263
          reg[RX_SP_REGNUM] = pv_add_constant (reg[RX_SP_REGNUM], -4);
264
          pv_area_store (stack, reg[RX_SP_REGNUM], 4, reg[rsrc]);
265
          after_last_frame_setup_insn = next_pc;
266
        }
267
      else if (opc.id == RXO_add        /* add #const, rsrc, rdst */
268
               && opc.op[0].type == RX_Operand_Register
269
               && opc.op[1].type == RX_Operand_Immediate
270
               && opc.op[2].type == RX_Operand_Register)
271
        {
272
          int rdst = opc.op[0].reg;
273
          int addend = opc.op[1].addend;
274
          int rsrc = opc.op[2].reg;
275
          reg[rdst] = pv_add_constant (reg[rsrc], addend);
276
          /* Negative adjustments to the stack pointer or frame pointer
277
             are (most likely) part of the prologue.  */
278
          if ((rdst == RX_SP_REGNUM || rdst == RX_FP_REGNUM) && addend < 0)
279
            after_last_frame_setup_insn = next_pc;
280
        }
281
      else if (opc.id == RXO_mov
282
               && opc.op[0].type == RX_Operand_Indirect
283
               && opc.op[1].type == RX_Operand_Register
284
               && opc.size == RX_Long
285
               && (opc.op[0].reg == RX_SP_REGNUM
286
                   || opc.op[0].reg == RX_FP_REGNUM)
287
               && (RX_R1_REGNUM <= opc.op[1].reg
288
                   && opc.op[1].reg <= RX_R4_REGNUM))
289
        {
290
          /* This moves an argument register to the stack.  Don't
291
             record it, but allow it to be a part of the prologue.  */
292
        }
293
      else if (opc.id == RXO_branch
294
               && opc.op[0].type == RX_Operand_Immediate
295
               && opc.op[1].type == RX_Operand_Condition
296
               && next_pc < opc.op[0].addend)
297
        {
298
          /* When a loop appears as the first statement of a function
299
             body, gcc 4.x will use a BRA instruction to branch to the
300
             loop condition checking code.  This BRA instruction is
301
             marked as part of the prologue.  We therefore set next_pc
302
             to this branch target and also stop the prologue scan.
303
             The instructions at and beyond the branch target should
304
             no longer be associated with the prologue.
305
 
306
             Note that we only consider forward branches here.  We
307
             presume that a forward branch is being used to skip over
308
             a loop body.
309
 
310
             A backwards branch is covered by the default case below.
311
             If we were to encounter a backwards branch, that would
312
             most likely mean that we've scanned through a loop body.
313
             We definitely want to stop the prologue scan when this
314
             happens and that is precisely what is done by the default
315
             case below.  */
316
 
317
          after_last_frame_setup_insn = opc.op[0].addend;
318
          break;                /* Scan no further if we hit this case.  */
319
        }
320
      else
321
        {
322
          /* Terminate the prologue scan.  */
323
          break;
324
        }
325
 
326
      pc = next_pc;
327
    }
328
 
329
  /* Is the frame size (offset, really) a known constant?  */
330
  if (pv_is_register (reg[RX_SP_REGNUM], RX_SP_REGNUM))
331
    result->frame_size = reg[RX_SP_REGNUM].k;
332
 
333
  /* Was the frame pointer initialized?  */
334
  if (pv_is_register (reg[RX_FP_REGNUM], RX_SP_REGNUM))
335
    {
336
      result->has_frame_ptr = 1;
337
      result->frame_ptr_offset = reg[RX_FP_REGNUM].k;
338
    }
339
 
340
  /* Record where all the registers were saved.  */
341
  pv_area_scan (stack, check_for_saved, (void *) result);
342
 
343
  result->prologue_end = after_last_frame_setup_insn;
344
 
345
  do_cleanups (back_to);
346
}
347
 
348
 
349
/* Implement the "skip_prologue" gdbarch method.  */
350
static CORE_ADDR
351
rx_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
352
{
353
  char *name;
354
  CORE_ADDR func_addr, func_end;
355
  struct rx_prologue p;
356
 
357
  /* Try to find the extent of the function that contains PC.  */
358
  if (!find_pc_partial_function (pc, &name, &func_addr, &func_end))
359
    return pc;
360
 
361
  rx_analyze_prologue (pc, func_end, &p);
362
  return p.prologue_end;
363
}
364
 
365
/* Given a frame described by THIS_FRAME, decode the prologue of its
366
   associated function if there is not cache entry as specified by
367
   THIS_PROLOGUE_CACHE.  Save the decoded prologue in the cache and
368
   return that struct as the value of this function.  */
369
static struct rx_prologue *
370
rx_analyze_frame_prologue (struct frame_info *this_frame,
371
                           void **this_prologue_cache)
372
{
373
  if (!*this_prologue_cache)
374
    {
375
      CORE_ADDR func_start, stop_addr;
376
 
377
      *this_prologue_cache = FRAME_OBSTACK_ZALLOC (struct rx_prologue);
378
 
379
      func_start = get_frame_func (this_frame);
380
      stop_addr = get_frame_pc (this_frame);
381
 
382
      /* If we couldn't find any function containing the PC, then
383
         just initialize the prologue cache, but don't do anything.  */
384
      if (!func_start)
385
        stop_addr = func_start;
386
 
387
      rx_analyze_prologue (func_start, stop_addr, *this_prologue_cache);
388
    }
389
 
390
  return *this_prologue_cache;
391
}
392
 
393
/* Given the next frame and a prologue cache, return this frame's
394
   base.  */
395
static CORE_ADDR
396
rx_frame_base (struct frame_info *this_frame, void **this_prologue_cache)
397
{
398
  struct rx_prologue *p
399
    = rx_analyze_frame_prologue (this_frame, this_prologue_cache);
400
 
401
  /* In functions that use alloca, the distance between the stack
402
     pointer and the frame base varies dynamically, so we can't use
403
     the SP plus static information like prologue analysis to find the
404
     frame base.  However, such functions must have a frame pointer,
405
     to be able to restore the SP on exit.  So whenever we do have a
406
     frame pointer, use that to find the base.  */
407
  if (p->has_frame_ptr)
408
    {
409
      CORE_ADDR fp = get_frame_register_unsigned (this_frame, RX_FP_REGNUM);
410
      return fp - p->frame_ptr_offset;
411
    }
412
  else
413
    {
414
      CORE_ADDR sp = get_frame_register_unsigned (this_frame, RX_SP_REGNUM);
415
      return sp - p->frame_size;
416
    }
417
}
418
 
419
/* Implement the "frame_this_id" method for unwinding frames.  */
420
static void
421
rx_frame_this_id (struct frame_info *this_frame,
422
                  void **this_prologue_cache, struct frame_id *this_id)
423
{
424
  *this_id = frame_id_build (rx_frame_base (this_frame, this_prologue_cache),
425
                             get_frame_func (this_frame));
426
}
427
 
428
/* Implement the "frame_prev_register" method for unwinding frames.  */
429
static struct value *
430
rx_frame_prev_register (struct frame_info *this_frame,
431
                        void **this_prologue_cache, int regnum)
432
{
433
  struct rx_prologue *p
434
    = rx_analyze_frame_prologue (this_frame, this_prologue_cache);
435
  CORE_ADDR frame_base = rx_frame_base (this_frame, this_prologue_cache);
436
  int reg_size = register_size (get_frame_arch (this_frame), regnum);
437
 
438
  if (regnum == RX_SP_REGNUM)
439
    return frame_unwind_got_constant (this_frame, regnum, frame_base);
440
 
441
  /* If prologue analysis says we saved this register somewhere,
442
     return a description of the stack slot holding it.  */
443
  else if (p->reg_offset[regnum] != 1)
444
    return frame_unwind_got_memory (this_frame, regnum,
445
                                    frame_base + p->reg_offset[regnum]);
446
 
447
  /* Otherwise, presume we haven't changed the value of this
448
     register, and get it from the next frame.  */
449
  else
450
    return frame_unwind_got_register (this_frame, regnum, regnum);
451
}
452
 
453
static const struct frame_unwind rx_frame_unwind = {
454
  NORMAL_FRAME,
455
  rx_frame_this_id,
456
  rx_frame_prev_register,
457
  NULL,
458
  default_frame_sniffer
459
};
460
 
461
/* Implement the "unwind_pc" gdbarch method.  */
462
static CORE_ADDR
463
rx_unwind_pc (struct gdbarch *gdbarch, struct frame_info *this_frame)
464
{
465
  ULONGEST pc;
466
 
467
  pc = frame_unwind_register_unsigned (this_frame, RX_PC_REGNUM);
468
  return pc;
469
}
470
 
471
/* Implement the "unwind_sp" gdbarch method.  */
472
static CORE_ADDR
473
rx_unwind_sp (struct gdbarch *gdbarch, struct frame_info *this_frame)
474
{
475
  ULONGEST sp;
476
 
477
  sp = frame_unwind_register_unsigned (this_frame, RX_SP_REGNUM);
478
  return sp;
479
}
480
 
481
/* Implement the "dummy_id" gdbarch method.  */
482
static struct frame_id
483
rx_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
484
{
485
  return
486
    frame_id_build (get_frame_register_unsigned (this_frame, RX_SP_REGNUM),
487
                    get_frame_pc (this_frame));
488
}
489
 
490
/* Implement the "push_dummy_call" gdbarch method.  */
491
static CORE_ADDR
492
rx_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
493
                    struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
494
                    struct value **args, CORE_ADDR sp, int struct_return,
495
                    CORE_ADDR struct_addr)
496
{
497
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
498
  int write_pass;
499
  int sp_off = 0;
500
  CORE_ADDR cfa;
501
  int num_register_candidate_args;
502
 
503
  struct type *func_type = value_type (function);
504
 
505
  /* Dereference function pointer types.  */
506
  while (TYPE_CODE (func_type) == TYPE_CODE_PTR)
507
    func_type = TYPE_TARGET_TYPE (func_type);
508
 
509
  /* The end result had better be a function or a method.  */
510
  gdb_assert (TYPE_CODE (func_type) == TYPE_CODE_FUNC
511
              || TYPE_CODE (func_type) == TYPE_CODE_METHOD);
512
 
513
  /* Functions with a variable number of arguments have all of their
514
     variable arguments and the last non-variable argument passed
515
     on the stack.
516
 
517
     Otherwise, we can pass up to four arguments on the stack.
518
 
519
     Once computed, we leave this value alone.  I.e. we don't update
520
     it in case of a struct return going in a register or an argument
521
     requiring multiple registers, etc.  We rely instead on the value
522
     of the ``arg_reg'' variable to get these other details correct.  */
523
 
524
  if (TYPE_VARARGS (func_type))
525
    num_register_candidate_args = TYPE_NFIELDS (func_type) - 1;
526
  else
527
    num_register_candidate_args = 4;
528
 
529
  /* We make two passes; the first does the stack allocation,
530
     the second actually stores the arguments.  */
531
  for (write_pass = 0; write_pass <= 1; write_pass++)
532
    {
533
      int i;
534
      int arg_reg = RX_R1_REGNUM;
535
 
536
      if (write_pass)
537
        sp = align_down (sp - sp_off, 4);
538
      sp_off = 0;
539
 
540
      if (struct_return)
541
        {
542
          struct type *return_type = TYPE_TARGET_TYPE (func_type);
543
 
544
          gdb_assert (TYPE_CODE (return_type) == TYPE_CODE_STRUCT
545
                      || TYPE_CODE (func_type) == TYPE_CODE_UNION);
546
 
547
          if (TYPE_LENGTH (return_type) > 16
548
              || TYPE_LENGTH (return_type) % 4 != 0)
549
            {
550
              if (write_pass)
551
                regcache_cooked_write_unsigned (regcache, RX_R15_REGNUM,
552
                                                struct_addr);
553
            }
554
        }
555
 
556
      /* Push the arguments.  */
557
      for (i = 0; i < nargs; i++)
558
        {
559
          struct value *arg = args[i];
560
          const gdb_byte *arg_bits = value_contents_all (arg);
561
          struct type *arg_type = check_typedef (value_type (arg));
562
          ULONGEST arg_size = TYPE_LENGTH (arg_type);
563
 
564
          if (i == 0 && struct_addr != 0 && !struct_return
565
              && TYPE_CODE (arg_type) == TYPE_CODE_PTR
566
              && extract_unsigned_integer (arg_bits, 4,
567
                                           byte_order) == struct_addr)
568
            {
569
              /* This argument represents the address at which C++ (and
570
                 possibly other languages) store their return value.
571
                 Put this value in R15.  */
572
              if (write_pass)
573
                regcache_cooked_write_unsigned (regcache, RX_R15_REGNUM,
574
                                                struct_addr);
575
            }
576
          else if (TYPE_CODE (arg_type) != TYPE_CODE_STRUCT
577
                   && TYPE_CODE (arg_type) != TYPE_CODE_UNION)
578
            {
579
              /* Argument is a scalar.  */
580
              if (arg_size == 8)
581
                {
582
                  if (i < num_register_candidate_args
583
                      && arg_reg <= RX_R4_REGNUM - 1)
584
                    {
585
                      /* If argument registers are going to be used to pass
586
                         an 8 byte scalar, the ABI specifies that two registers
587
                         must be available.  */
588
                      if (write_pass)
589
                        {
590
                          regcache_cooked_write_unsigned (regcache, arg_reg,
591
                                                          extract_unsigned_integer
592
                                                          (arg_bits, 4,
593
                                                           byte_order));
594
                          regcache_cooked_write_unsigned (regcache,
595
                                                          arg_reg + 1,
596
                                                          extract_unsigned_integer
597
                                                          (arg_bits + 4, 4,
598
                                                           byte_order));
599
                        }
600
                      arg_reg += 2;
601
                    }
602
                  else
603
                    {
604
                      sp_off = align_up (sp_off, 4);
605
                      /* Otherwise, pass the 8 byte scalar on the stack.  */
606
                      if (write_pass)
607
                        write_memory (sp + sp_off, arg_bits, 8);
608
                      sp_off += 8;
609
                    }
610
                }
611
              else
612
                {
613
                  ULONGEST u;
614
 
615
                  gdb_assert (arg_size <= 4);
616
 
617
                  u =
618
                    extract_unsigned_integer (arg_bits, arg_size, byte_order);
619
 
620
                  if (i < num_register_candidate_args
621
                      && arg_reg <= RX_R4_REGNUM)
622
                    {
623
                      if (write_pass)
624
                        regcache_cooked_write_unsigned (regcache, arg_reg, u);
625
                      arg_reg += 1;
626
                    }
627
                  else
628
                    {
629
                      int p_arg_size = 4;
630
 
631
                      if (TYPE_PROTOTYPED (func_type)
632
                          && i < TYPE_NFIELDS (func_type))
633
                        {
634
                          struct type *p_arg_type =
635
                            TYPE_FIELD_TYPE (func_type, i);
636
                          p_arg_size = TYPE_LENGTH (p_arg_type);
637
                        }
638
 
639
                      sp_off = align_up (sp_off, p_arg_size);
640
 
641
                      if (write_pass)
642
                        write_memory_unsigned_integer (sp + sp_off,
643
                                                       p_arg_size, byte_order,
644
                                                       u);
645
                      sp_off += p_arg_size;
646
                    }
647
                }
648
            }
649
          else
650
            {
651
              /* Argument is a struct or union.  Pass as much of the struct
652
                 in registers, if possible.  Pass the rest on the stack.  */
653
              while (arg_size > 0)
654
                {
655
                  if (i < num_register_candidate_args
656
                      && arg_reg <= RX_R4_REGNUM
657
                      && arg_size <= 4 * (RX_R4_REGNUM - arg_reg + 1)
658
                      && arg_size % 4 == 0)
659
                    {
660
                      int len = min (arg_size, 4);
661
 
662
                      if (write_pass)
663
                        regcache_cooked_write_unsigned (regcache, arg_reg,
664
                                                        extract_unsigned_integer
665
                                                        (arg_bits, len,
666
                                                         byte_order));
667
                      arg_bits += len;
668
                      arg_size -= len;
669
                      arg_reg++;
670
                    }
671
                  else
672
                    {
673
                      sp_off = align_up (sp_off, 4);
674
                      if (write_pass)
675
                        write_memory (sp + sp_off, arg_bits, arg_size);
676
                      sp_off += align_up (arg_size, 4);
677
                      arg_size = 0;
678
                    }
679
                }
680
            }
681
        }
682
    }
683
 
684
  /* Keep track of the stack address prior to pushing the return address.
685
     This is the value that we'll return.  */
686
  cfa = sp;
687
 
688
  /* Push the return address.  */
689
  sp = sp - 4;
690
  write_memory_unsigned_integer (sp, 4, byte_order, bp_addr);
691
 
692
  /* Update the stack pointer.  */
693
  regcache_cooked_write_unsigned (regcache, RX_SP_REGNUM, sp);
694
 
695
  return cfa;
696
}
697
 
698
/* Implement the "return_value" gdbarch method.  */
699
static enum return_value_convention
700
rx_return_value (struct gdbarch *gdbarch,
701
                 struct type *func_type,
702
                 struct type *valtype,
703
                 struct regcache *regcache,
704
                 gdb_byte *readbuf, const gdb_byte *writebuf)
705
{
706
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
707
  ULONGEST valtype_len = TYPE_LENGTH (valtype);
708
 
709
  if (TYPE_LENGTH (valtype) > 16
710
      || ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
711
           || TYPE_CODE (valtype) == TYPE_CODE_UNION)
712
          && TYPE_LENGTH (valtype) % 4 != 0))
713
    return RETURN_VALUE_STRUCT_CONVENTION;
714
 
715
  if (readbuf)
716
    {
717
      ULONGEST u;
718
      int argreg = RX_R1_REGNUM;
719
      int offset = 0;
720
 
721
      while (valtype_len > 0)
722
        {
723
          int len = min (valtype_len, 4);
724
 
725
          regcache_cooked_read_unsigned (regcache, argreg, &u);
726
          store_unsigned_integer (readbuf + offset, len, byte_order, u);
727
          valtype_len -= len;
728
          offset += len;
729
          argreg++;
730
        }
731
    }
732
 
733
  if (writebuf)
734
    {
735
      ULONGEST u;
736
      int argreg = RX_R1_REGNUM;
737
      int offset = 0;
738
 
739
      while (valtype_len > 0)
740
        {
741
          int len = min (valtype_len, 4);
742
 
743
          u = extract_unsigned_integer (writebuf + offset, len, byte_order);
744
          regcache_cooked_write_unsigned (regcache, argreg, u);
745
          valtype_len -= len;
746
          offset += len;
747
          argreg++;
748
        }
749
    }
750
 
751
  return RETURN_VALUE_REGISTER_CONVENTION;
752
}
753
 
754
/* Implement the "breakpoint_from_pc" gdbarch method.  */
755
const gdb_byte *
756
rx_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr, int *lenptr)
757
{
758
  static gdb_byte breakpoint[] = { 0x00 };
759
  *lenptr = sizeof breakpoint;
760
  return breakpoint;
761
}
762
 
763
/* Allocate and initialize a gdbarch object.  */
764
static struct gdbarch *
765
rx_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
766
{
767
  struct gdbarch *gdbarch;
768
  struct gdbarch_tdep *tdep;
769
  int elf_flags;
770
 
771
  /* Extract the elf_flags if available.  */
772
  if (info.abfd != NULL
773
      && bfd_get_flavour (info.abfd) == bfd_target_elf_flavour)
774
    elf_flags = elf_elfheader (info.abfd)->e_flags;
775
  else
776
    elf_flags = 0;
777
 
778
 
779
  /* Try to find the architecture in the list of already defined
780
     architectures.  */
781
  for (arches = gdbarch_list_lookup_by_info (arches, &info);
782
       arches != NULL;
783
       arches = gdbarch_list_lookup_by_info (arches->next, &info))
784
    {
785
      if (gdbarch_tdep (arches->gdbarch)->elf_flags != elf_flags)
786
        continue;
787
 
788
      return arches->gdbarch;
789
    }
790
 
791
  /* None found, create a new architecture from the information
792
     provided.  */
793
  tdep = (struct gdbarch_tdep *) xmalloc (sizeof (struct gdbarch_tdep));
794
  gdbarch = gdbarch_alloc (&info, tdep);
795
  tdep->elf_flags = elf_flags;
796
 
797
  set_gdbarch_num_regs (gdbarch, RX_NUM_REGS);
798
  set_gdbarch_num_pseudo_regs (gdbarch, 0);
799
  set_gdbarch_register_name (gdbarch, rx_register_name);
800
  set_gdbarch_register_type (gdbarch, rx_register_type);
801
  set_gdbarch_pc_regnum (gdbarch, RX_PC_REGNUM);
802
  set_gdbarch_sp_regnum (gdbarch, RX_SP_REGNUM);
803
  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
804
  set_gdbarch_decr_pc_after_break (gdbarch, 1);
805
  set_gdbarch_breakpoint_from_pc (gdbarch, rx_breakpoint_from_pc);
806
  set_gdbarch_skip_prologue (gdbarch, rx_skip_prologue);
807
 
808
  set_gdbarch_print_insn (gdbarch, print_insn_rx);
809
 
810
  set_gdbarch_unwind_pc (gdbarch, rx_unwind_pc);
811
  set_gdbarch_unwind_sp (gdbarch, rx_unwind_sp);
812
 
813
  /* Target builtin data types.  */
814
  set_gdbarch_char_signed (gdbarch, 0);
815
  set_gdbarch_short_bit (gdbarch, 16);
816
  set_gdbarch_int_bit (gdbarch, 32);
817
  set_gdbarch_long_bit (gdbarch, 32);
818
  set_gdbarch_long_long_bit (gdbarch, 64);
819
  set_gdbarch_ptr_bit (gdbarch, 32);
820
  set_gdbarch_float_bit (gdbarch, 32);
821
  set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
822
  if (elf_flags & E_FLAG_RX_64BIT_DOUBLES)
823
    {
824
      set_gdbarch_double_bit (gdbarch, 64);
825
      set_gdbarch_long_double_bit (gdbarch, 64);
826
      set_gdbarch_double_format (gdbarch, floatformats_ieee_double);
827
      set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
828
    }
829
  else
830
    {
831
      set_gdbarch_double_bit (gdbarch, 32);
832
      set_gdbarch_long_double_bit (gdbarch, 32);
833
      set_gdbarch_double_format (gdbarch, floatformats_ieee_single);
834
      set_gdbarch_long_double_format (gdbarch, floatformats_ieee_single);
835
    }
836
 
837
  /* Frame unwinding.  */
838
#if 0
839
  /* Note: The test results are better with the dwarf2 unwinder disabled,
840
     so it's turned off for now.  */
841
  dwarf2_append_unwinders (gdbarch);
842
#endif
843
  frame_unwind_append_unwinder (gdbarch, &rx_frame_unwind);
844
 
845
  /* Methods for saving / extracting a dummy frame's ID.
846
     The ID's stack address must match the SP value returned by
847
     PUSH_DUMMY_CALL, and saved by generic_save_dummy_frame_tos.  */
848
  set_gdbarch_dummy_id (gdbarch, rx_dummy_id);
849
  set_gdbarch_push_dummy_call (gdbarch, rx_push_dummy_call);
850
  set_gdbarch_return_value (gdbarch, rx_return_value);
851
 
852
  /* Virtual tables.  */
853
  set_gdbarch_vbit_in_delta (gdbarch, 1);
854
 
855
  return gdbarch;
856
}
857
 
858
/* Register the above initialization routine.  */
859
void
860
_initialize_rx_tdep (void)
861
{
862
  register_gdbarch_init (bfd_arch_rx, rx_gdbarch_init);
863
}

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