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[/] [openrisc/] [trunk/] [gnu-old/] [gdb-6.8/] [gdb/] [m32r-tdep.c] - Blame information for rev 853

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1 24 jeremybenn
/* Target-dependent code for Renesas M32R, for GDB.
2
 
3
   Copyright (C) 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007,
4
   2008 Free Software Foundation, Inc.
5
 
6
   This file is part of GDB.
7
 
8
   This program is free software; you can redistribute it and/or modify
9
   it under the terms of the GNU General Public License as published by
10
   the Free Software Foundation; either version 3 of the License, or
11
   (at your option) any later version.
12
 
13
   This program is distributed in the hope that it will be useful,
14
   but WITHOUT ANY WARRANTY; without even the implied warranty of
15
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16
   GNU General Public License for more details.
17
 
18
   You should have received a copy of the GNU General Public License
19
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
20
 
21
#include "defs.h"
22
#include "frame.h"
23
#include "frame-unwind.h"
24
#include "frame-base.h"
25
#include "symtab.h"
26
#include "gdbtypes.h"
27
#include "gdbcmd.h"
28
#include "gdbcore.h"
29
#include "gdb_string.h"
30
#include "value.h"
31
#include "inferior.h"
32
#include "symfile.h"
33
#include "objfiles.h"
34
#include "osabi.h"
35
#include "language.h"
36
#include "arch-utils.h"
37
#include "regcache.h"
38
#include "trad-frame.h"
39
#include "dis-asm.h"
40
 
41
#include "gdb_assert.h"
42
 
43
#include "m32r-tdep.h"
44
 
45
/* Local functions */
46
 
47
extern void _initialize_m32r_tdep (void);
48
 
49
static CORE_ADDR
50
m32r_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
51
{
52
  /* Align to the size of an instruction (so that they can safely be
53
     pushed onto the stack.  */
54
  return sp & ~3;
55
}
56
 
57
 
58
/* Breakpoints
59
 
60
   The little endian mode of M32R is unique. In most of architectures,
61
   two 16-bit instructions, A and B, are placed as the following:
62
 
63
   Big endian:
64
   A0 A1 B0 B1
65
 
66
   Little endian:
67
   A1 A0 B1 B0
68
 
69
   In M32R, they are placed like this:
70
 
71
   Big endian:
72
   A0 A1 B0 B1
73
 
74
   Little endian:
75
   B1 B0 A1 A0
76
 
77
   This is because M32R always fetches instructions in 32-bit.
78
 
79
   The following functions take care of this behavior. */
80
 
81
static int
82
m32r_memory_insert_breakpoint (struct gdbarch *gdbarch,
83
                               struct bp_target_info *bp_tgt)
84
{
85
  CORE_ADDR addr = bp_tgt->placed_address;
86
  int val;
87
  gdb_byte buf[4];
88
  gdb_byte *contents_cache = bp_tgt->shadow_contents;
89
  gdb_byte bp_entry[] = { 0x10, 0xf1 }; /* dpt */
90
 
91
  /* Save the memory contents.  */
92
  val = target_read_memory (addr & 0xfffffffc, contents_cache, 4);
93
  if (val != 0)
94
    return val;                 /* return error */
95
 
96
  bp_tgt->placed_size = bp_tgt->shadow_len = 4;
97
 
98
  /* Determine appropriate breakpoint contents and size for this address.  */
99
  if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
100
    {
101
      if ((addr & 3) == 0)
102
        {
103
          buf[0] = bp_entry[0];
104
          buf[1] = bp_entry[1];
105
          buf[2] = contents_cache[2] & 0x7f;
106
          buf[3] = contents_cache[3];
107
        }
108
      else
109
        {
110
          buf[0] = contents_cache[0];
111
          buf[1] = contents_cache[1];
112
          buf[2] = bp_entry[0];
113
          buf[3] = bp_entry[1];
114
        }
115
    }
116
  else                          /* little-endian */
117
    {
118
      if ((addr & 3) == 0)
119
        {
120
          buf[0] = contents_cache[0];
121
          buf[1] = contents_cache[1] & 0x7f;
122
          buf[2] = bp_entry[1];
123
          buf[3] = bp_entry[0];
124
        }
125
      else
126
        {
127
          buf[0] = bp_entry[1];
128
          buf[1] = bp_entry[0];
129
          buf[2] = contents_cache[2];
130
          buf[3] = contents_cache[3];
131
        }
132
    }
133
 
134
  /* Write the breakpoint.  */
135
  val = target_write_memory (addr & 0xfffffffc, buf, 4);
136
  return val;
137
}
138
 
139
static int
140
m32r_memory_remove_breakpoint (struct gdbarch *gdbarch,
141
                               struct bp_target_info *bp_tgt)
142
{
143
  CORE_ADDR addr = bp_tgt->placed_address;
144
  int val;
145
  gdb_byte buf[4];
146
  gdb_byte *contents_cache = bp_tgt->shadow_contents;
147
 
148
  buf[0] = contents_cache[0];
149
  buf[1] = contents_cache[1];
150
  buf[2] = contents_cache[2];
151
  buf[3] = contents_cache[3];
152
 
153
  /* Remove parallel bit.  */
154
  if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
155
    {
156
      if ((buf[0] & 0x80) == 0 && (buf[2] & 0x80) != 0)
157
        buf[2] &= 0x7f;
158
    }
159
  else                          /* little-endian */
160
    {
161
      if ((buf[3] & 0x80) == 0 && (buf[1] & 0x80) != 0)
162
        buf[1] &= 0x7f;
163
    }
164
 
165
  /* Write contents.  */
166
  val = target_write_memory (addr & 0xfffffffc, buf, 4);
167
  return val;
168
}
169
 
170
static const gdb_byte *
171
m32r_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr, int *lenptr)
172
{
173
  static gdb_byte be_bp_entry[] = { 0x10, 0xf1, 0x70, 0x00 };   /* dpt -> nop */
174
  static gdb_byte le_bp_entry[] = { 0x00, 0x70, 0xf1, 0x10 };   /* dpt -> nop */
175
  gdb_byte *bp;
176
 
177
  /* Determine appropriate breakpoint.  */
178
  if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
179
    {
180
      if ((*pcptr & 3) == 0)
181
        {
182
          bp = be_bp_entry;
183
          *lenptr = 4;
184
        }
185
      else
186
        {
187
          bp = be_bp_entry;
188
          *lenptr = 2;
189
        }
190
    }
191
  else
192
    {
193
      if ((*pcptr & 3) == 0)
194
        {
195
          bp = le_bp_entry;
196
          *lenptr = 4;
197
        }
198
      else
199
        {
200
          bp = le_bp_entry + 2;
201
          *lenptr = 2;
202
        }
203
    }
204
 
205
  return bp;
206
}
207
 
208
 
209
char *m32r_register_names[] = {
210
  "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
211
  "r8", "r9", "r10", "r11", "r12", "fp", "lr", "sp",
212
  "psw", "cbr", "spi", "spu", "bpc", "pc", "accl", "acch",
213
  "evb"
214
};
215
 
216
static const char *
217
m32r_register_name (struct gdbarch *gdbarch, int reg_nr)
218
{
219
  if (reg_nr < 0)
220
    return NULL;
221
  if (reg_nr >= M32R_NUM_REGS)
222
    return NULL;
223
  return m32r_register_names[reg_nr];
224
}
225
 
226
 
227
/* Return the GDB type object for the "standard" data type
228
   of data in register N.  */
229
 
230
static struct type *
231
m32r_register_type (struct gdbarch *gdbarch, int reg_nr)
232
{
233
  if (reg_nr == M32R_PC_REGNUM)
234
    return builtin_type_void_func_ptr;
235
  else if (reg_nr == M32R_SP_REGNUM || reg_nr == M32R_FP_REGNUM)
236
    return builtin_type_void_data_ptr;
237
  else
238
    return builtin_type_int32;
239
}
240
 
241
 
242
/* Write into appropriate registers a function return value
243
   of type TYPE, given in virtual format.
244
 
245
   Things always get returned in RET1_REGNUM, RET2_REGNUM. */
246
 
247
static void
248
m32r_store_return_value (struct type *type, struct regcache *regcache,
249
                         const void *valbuf)
250
{
251
  CORE_ADDR regval;
252
  int len = TYPE_LENGTH (type);
253
 
254
  regval = extract_unsigned_integer (valbuf, len > 4 ? 4 : len);
255
  regcache_cooked_write_unsigned (regcache, RET1_REGNUM, regval);
256
 
257
  if (len > 4)
258
    {
259
      regval = extract_unsigned_integer ((gdb_byte *) valbuf + 4, len - 4);
260
      regcache_cooked_write_unsigned (regcache, RET1_REGNUM + 1, regval);
261
    }
262
}
263
 
264
/* This is required by skip_prologue. The results of decoding a prologue
265
   should be cached because this thrashing is getting nuts.  */
266
 
267
static int
268
decode_prologue (CORE_ADDR start_pc, CORE_ADDR scan_limit,
269
                 CORE_ADDR *pl_endptr, unsigned long *framelength)
270
{
271
  unsigned long framesize;
272
  int insn;
273
  int op1;
274
  CORE_ADDR after_prologue = 0;
275
  CORE_ADDR after_push = 0;
276
  CORE_ADDR after_stack_adjust = 0;
277
  CORE_ADDR current_pc;
278
  LONGEST return_value;
279
 
280
  framesize = 0;
281
  after_prologue = 0;
282
 
283
  for (current_pc = start_pc; current_pc < scan_limit; current_pc += 2)
284
    {
285
      /* Check if current pc's location is readable. */
286
      if (!safe_read_memory_integer (current_pc, 2, &return_value))
287
        return -1;
288
 
289
      insn = read_memory_unsigned_integer (current_pc, 2);
290
 
291
      if (insn == 0x0000)
292
        break;
293
 
294
      /* If this is a 32 bit instruction, we dont want to examine its
295
         immediate data as though it were an instruction */
296
      if (current_pc & 0x02)
297
        {
298
          /* decode this instruction further */
299
          insn &= 0x7fff;
300
        }
301
      else
302
        {
303
          if (insn & 0x8000)
304
            {
305
              if (current_pc == scan_limit)
306
                scan_limit += 2;        /* extend the search */
307
 
308
              current_pc += 2;  /* skip the immediate data */
309
 
310
              /* Check if current pc's location is readable. */
311
              if (!safe_read_memory_integer (current_pc, 2, &return_value))
312
                return -1;
313
 
314
              if (insn == 0x8faf)       /* add3 sp, sp, xxxx */
315
                /* add 16 bit sign-extended offset */
316
                {
317
                  framesize +=
318
                    -((short) read_memory_unsigned_integer (current_pc, 2));
319
                }
320
              else
321
                {
322
                  if (((insn >> 8) == 0xe4)     /* ld24 r4, xxxxxx; sub sp, r4 */
323
                      && safe_read_memory_integer (current_pc + 2, 2,
324
                                                   &return_value)
325
                      && read_memory_unsigned_integer (current_pc + 2,
326
                                                       2) == 0x0f24)
327
                    /* subtract 24 bit sign-extended negative-offset */
328
                    {
329
                      insn = read_memory_unsigned_integer (current_pc - 2, 4);
330
                      if (insn & 0x00800000)    /* sign extend */
331
                        insn |= 0xff000000;     /* negative */
332
                      else
333
                        insn &= 0x00ffffff;     /* positive */
334
                      framesize += insn;
335
                    }
336
                }
337
              after_push = current_pc + 2;
338
              continue;
339
            }
340
        }
341
      op1 = insn & 0xf000;      /* isolate just the first nibble */
342
 
343
      if ((insn & 0xf0ff) == 0x207f)
344
        {                       /* st reg, @-sp */
345
          int regno;
346
          framesize += 4;
347
          regno = ((insn >> 8) & 0xf);
348
          after_prologue = 0;
349
          continue;
350
        }
351
      if ((insn >> 8) == 0x4f)  /* addi sp, xx */
352
        /* add 8 bit sign-extended offset */
353
        {
354
          int stack_adjust = (signed char) (insn & 0xff);
355
 
356
          /* there are probably two of these stack adjustments:
357
             1) A negative one in the prologue, and
358
             2) A positive one in the epilogue.
359
             We are only interested in the first one.  */
360
 
361
          if (stack_adjust < 0)
362
            {
363
              framesize -= stack_adjust;
364
              after_prologue = 0;
365
              /* A frameless function may have no "mv fp, sp".
366
                 In that case, this is the end of the prologue.  */
367
              after_stack_adjust = current_pc + 2;
368
            }
369
          continue;
370
        }
371
      if (insn == 0x1d8f)
372
        {                       /* mv fp, sp */
373
          after_prologue = current_pc + 2;
374
          break;                /* end of stack adjustments */
375
        }
376
 
377
      /* Nop looks like a branch, continue explicitly */
378
      if (insn == 0x7000)
379
        {
380
          after_prologue = current_pc + 2;
381
          continue;             /* nop occurs between pushes */
382
        }
383
      /* End of prolog if any of these are trap instructions */
384
      if ((insn & 0xfff0) == 0x10f0)
385
        {
386
          after_prologue = current_pc;
387
          break;
388
        }
389
      /* End of prolog if any of these are branch instructions */
390
      if ((op1 == 0x7000) || (op1 == 0xb000) || (op1 == 0xf000))
391
        {
392
          after_prologue = current_pc;
393
          continue;
394
        }
395
      /* Some of the branch instructions are mixed with other types */
396
      if (op1 == 0x1000)
397
        {
398
          int subop = insn & 0x0ff0;
399
          if ((subop == 0x0ec0) || (subop == 0x0fc0))
400
            {
401
              after_prologue = current_pc;
402
              continue;         /* jmp , jl */
403
            }
404
        }
405
    }
406
 
407
  if (framelength)
408
    *framelength = framesize;
409
 
410
  if (current_pc >= scan_limit)
411
    {
412
      if (pl_endptr)
413
        {
414
          if (after_stack_adjust != 0)
415
            /* We did not find a "mv fp,sp", but we DID find
416
               a stack_adjust.  Is it safe to use that as the
417
               end of the prologue?  I just don't know. */
418
            {
419
              *pl_endptr = after_stack_adjust;
420
            }
421
          else if (after_push != 0)
422
            /* We did not find a "mv fp,sp", but we DID find
423
               a push.  Is it safe to use that as the
424
               end of the prologue?  I just don't know. */
425
            {
426
              *pl_endptr = after_push;
427
            }
428
          else
429
            /* We reached the end of the loop without finding the end
430
               of the prologue.  No way to win -- we should report failure.
431
               The way we do that is to return the original start_pc.
432
               GDB will set a breakpoint at the start of the function (etc.) */
433
            *pl_endptr = start_pc;
434
        }
435
      return 0;
436
    }
437
 
438
  if (after_prologue == 0)
439
    after_prologue = current_pc;
440
 
441
  if (pl_endptr)
442
    *pl_endptr = after_prologue;
443
 
444
  return 0;
445
}                               /*  decode_prologue */
446
 
447
/* Function: skip_prologue
448
   Find end of function prologue */
449
 
450
#define DEFAULT_SEARCH_LIMIT 128
451
 
452
CORE_ADDR
453
m32r_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
454
{
455
  CORE_ADDR func_addr, func_end;
456
  struct symtab_and_line sal;
457
  LONGEST return_value;
458
 
459
  /* See what the symbol table says */
460
 
461
  if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
462
    {
463
      sal = find_pc_line (func_addr, 0);
464
 
465
      if (sal.line != 0 && sal.end <= func_end)
466
        {
467
          func_end = sal.end;
468
        }
469
      else
470
        /* Either there's no line info, or the line after the prologue is after
471
           the end of the function.  In this case, there probably isn't a
472
           prologue.  */
473
        {
474
          func_end = min (func_end, func_addr + DEFAULT_SEARCH_LIMIT);
475
        }
476
    }
477
  else
478
    func_end = pc + DEFAULT_SEARCH_LIMIT;
479
 
480
  /* If pc's location is not readable, just quit. */
481
  if (!safe_read_memory_integer (pc, 4, &return_value))
482
    return pc;
483
 
484
  /* Find the end of prologue.  */
485
  if (decode_prologue (pc, func_end, &sal.end, NULL) < 0)
486
    return pc;
487
 
488
  return sal.end;
489
}
490
 
491
struct m32r_unwind_cache
492
{
493
  /* The previous frame's inner most stack address.  Used as this
494
     frame ID's stack_addr.  */
495
  CORE_ADDR prev_sp;
496
  /* The frame's base, optionally used by the high-level debug info.  */
497
  CORE_ADDR base;
498
  int size;
499
  /* How far the SP and r13 (FP) have been offset from the start of
500
     the stack frame (as defined by the previous frame's stack
501
     pointer).  */
502
  LONGEST sp_offset;
503
  LONGEST r13_offset;
504
  int uses_frame;
505
  /* Table indicating the location of each and every register.  */
506
  struct trad_frame_saved_reg *saved_regs;
507
};
508
 
509
/* Put here the code to store, into fi->saved_regs, the addresses of
510
   the saved registers of frame described by FRAME_INFO.  This
511
   includes special registers such as pc and fp saved in special ways
512
   in the stack frame.  sp is even more special: the address we return
513
   for it IS the sp for the next frame. */
514
 
515
static struct m32r_unwind_cache *
516
m32r_frame_unwind_cache (struct frame_info *next_frame,
517
                         void **this_prologue_cache)
518
{
519
  CORE_ADDR pc, scan_limit;
520
  ULONGEST prev_sp;
521
  ULONGEST this_base;
522
  unsigned long op, op2;
523
  int i;
524
  struct m32r_unwind_cache *info;
525
 
526
 
527
  if ((*this_prologue_cache))
528
    return (*this_prologue_cache);
529
 
530
  info = FRAME_OBSTACK_ZALLOC (struct m32r_unwind_cache);
531
  (*this_prologue_cache) = info;
532
  info->saved_regs = trad_frame_alloc_saved_regs (next_frame);
533
 
534
  info->size = 0;
535
  info->sp_offset = 0;
536
  info->uses_frame = 0;
537
 
538
  scan_limit = frame_pc_unwind (next_frame);
539
  for (pc = frame_func_unwind (next_frame, NORMAL_FRAME);
540
       pc > 0 && pc < scan_limit; pc += 2)
541
    {
542
      if ((pc & 2) == 0)
543
        {
544
          op = get_frame_memory_unsigned (next_frame, pc, 4);
545
          if ((op & 0x80000000) == 0x80000000)
546
            {
547
              /* 32-bit instruction */
548
              if ((op & 0xffff0000) == 0x8faf0000)
549
                {
550
                  /* add3 sp,sp,xxxx */
551
                  short n = op & 0xffff;
552
                  info->sp_offset += n;
553
                }
554
              else if (((op >> 8) == 0xe4)
555
                       && get_frame_memory_unsigned (next_frame, pc + 2,
556
                                                     2) == 0x0f24)
557
                {
558
                  /* ld24 r4, xxxxxx; sub sp, r4 */
559
                  unsigned long n = op & 0xffffff;
560
                  info->sp_offset += n;
561
                  pc += 2;      /* skip sub instruction */
562
                }
563
 
564
              if (pc == scan_limit)
565
                scan_limit += 2;        /* extend the search */
566
              pc += 2;          /* skip the immediate data */
567
              continue;
568
            }
569
        }
570
 
571
      /* 16-bit instructions */
572
      op = get_frame_memory_unsigned (next_frame, pc, 2) & 0x7fff;
573
      if ((op & 0xf0ff) == 0x207f)
574
        {
575
          /* st rn, @-sp */
576
          int regno = ((op >> 8) & 0xf);
577
          info->sp_offset -= 4;
578
          info->saved_regs[regno].addr = info->sp_offset;
579
        }
580
      else if ((op & 0xff00) == 0x4f00)
581
        {
582
          /* addi sp, xx */
583
          int n = (signed char) (op & 0xff);
584
          info->sp_offset += n;
585
        }
586
      else if (op == 0x1d8f)
587
        {
588
          /* mv fp, sp */
589
          info->uses_frame = 1;
590
          info->r13_offset = info->sp_offset;
591
          break;                /* end of stack adjustments */
592
        }
593
      else if ((op & 0xfff0) == 0x10f0)
594
        {
595
          /* end of prologue if this is a trap instruction */
596
          break;                /* end of stack adjustments */
597
        }
598
    }
599
 
600
  info->size = -info->sp_offset;
601
 
602
  /* Compute the previous frame's stack pointer (which is also the
603
     frame's ID's stack address), and this frame's base pointer.  */
604
  if (info->uses_frame)
605
    {
606
      /* The SP was moved to the FP.  This indicates that a new frame
607
         was created.  Get THIS frame's FP value by unwinding it from
608
         the next frame.  */
609
      this_base = frame_unwind_register_unsigned (next_frame, M32R_FP_REGNUM);
610
      /* The FP points at the last saved register.  Adjust the FP back
611
         to before the first saved register giving the SP.  */
612
      prev_sp = this_base + info->size;
613
    }
614
  else
615
    {
616
      /* Assume that the FP is this frame's SP but with that pushed
617
         stack space added back.  */
618
      this_base = frame_unwind_register_unsigned (next_frame, M32R_SP_REGNUM);
619
      prev_sp = this_base + info->size;
620
    }
621
 
622
  /* Convert that SP/BASE into real addresses.  */
623
  info->prev_sp = prev_sp;
624
  info->base = this_base;
625
 
626
  /* Adjust all the saved registers so that they contain addresses and
627
     not offsets.  */
628
  for (i = 0; i < gdbarch_num_regs (get_frame_arch (next_frame)) - 1; i++)
629
    if (trad_frame_addr_p (info->saved_regs, i))
630
      info->saved_regs[i].addr = (info->prev_sp + info->saved_regs[i].addr);
631
 
632
  /* The call instruction moves the caller's PC in the callee's LR.
633
     Since this is an unwind, do the reverse.  Copy the location of LR
634
     into PC (the address / regnum) so that a request for PC will be
635
     converted into a request for the LR.  */
636
  info->saved_regs[M32R_PC_REGNUM] = info->saved_regs[LR_REGNUM];
637
 
638
  /* The previous frame's SP needed to be computed.  Save the computed
639
     value.  */
640
  trad_frame_set_value (info->saved_regs, M32R_SP_REGNUM, prev_sp);
641
 
642
  return info;
643
}
644
 
645
static CORE_ADDR
646
m32r_read_pc (struct regcache *regcache)
647
{
648
  ULONGEST pc;
649
  regcache_cooked_read_unsigned (regcache, M32R_PC_REGNUM, &pc);
650
  return pc;
651
}
652
 
653
static void
654
m32r_write_pc (struct regcache *regcache, CORE_ADDR val)
655
{
656
  regcache_cooked_write_unsigned (regcache, M32R_PC_REGNUM, val);
657
}
658
 
659
static CORE_ADDR
660
m32r_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame)
661
{
662
  return frame_unwind_register_unsigned (next_frame, M32R_SP_REGNUM);
663
}
664
 
665
 
666
static CORE_ADDR
667
m32r_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
668
                      struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
669
                      struct value **args, CORE_ADDR sp, int struct_return,
670
                      CORE_ADDR struct_addr)
671
{
672
  int stack_offset, stack_alloc;
673
  int argreg = ARG1_REGNUM;
674
  int argnum;
675
  struct type *type;
676
  enum type_code typecode;
677
  CORE_ADDR regval;
678
  gdb_byte *val;
679
  gdb_byte valbuf[MAX_REGISTER_SIZE];
680
  int len;
681
  int odd_sized_struct;
682
 
683
  /* first force sp to a 4-byte alignment */
684
  sp = sp & ~3;
685
 
686
  /* Set the return address.  For the m32r, the return breakpoint is
687
     always at BP_ADDR.  */
688
  regcache_cooked_write_unsigned (regcache, LR_REGNUM, bp_addr);
689
 
690
  /* If STRUCT_RETURN is true, then the struct return address (in
691
     STRUCT_ADDR) will consume the first argument-passing register.
692
     Both adjust the register count and store that value.  */
693
  if (struct_return)
694
    {
695
      regcache_cooked_write_unsigned (regcache, argreg, struct_addr);
696
      argreg++;
697
    }
698
 
699
  /* Now make sure there's space on the stack */
700
  for (argnum = 0, stack_alloc = 0; argnum < nargs; argnum++)
701
    stack_alloc += ((TYPE_LENGTH (value_type (args[argnum])) + 3) & ~3);
702
  sp -= stack_alloc;            /* make room on stack for args */
703
 
704
  for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++)
705
    {
706
      type = value_type (args[argnum]);
707
      typecode = TYPE_CODE (type);
708
      len = TYPE_LENGTH (type);
709
 
710
      memset (valbuf, 0, sizeof (valbuf));
711
 
712
      /* Passes structures that do not fit in 2 registers by reference.  */
713
      if (len > 8
714
          && (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION))
715
        {
716
          store_unsigned_integer (valbuf, 4, VALUE_ADDRESS (args[argnum]));
717
          typecode = TYPE_CODE_PTR;
718
          len = 4;
719
          val = valbuf;
720
        }
721
      else if (len < 4)
722
        {
723
          /* value gets right-justified in the register or stack word */
724
          memcpy (valbuf + (register_size (gdbarch, argreg) - len),
725
                  (gdb_byte *) value_contents (args[argnum]), len);
726
          val = valbuf;
727
        }
728
      else
729
        val = (gdb_byte *) value_contents (args[argnum]);
730
 
731
      while (len > 0)
732
        {
733
          if (argreg > ARGN_REGNUM)
734
            {
735
              /* must go on the stack */
736
              write_memory (sp + stack_offset, val, 4);
737
              stack_offset += 4;
738
            }
739
          else if (argreg <= ARGN_REGNUM)
740
            {
741
              /* there's room in a register */
742
              regval =
743
                extract_unsigned_integer (val,
744
                                          register_size (gdbarch, argreg));
745
              regcache_cooked_write_unsigned (regcache, argreg++, regval);
746
            }
747
 
748
          /* Store the value 4 bytes at a time.  This means that things
749
             larger than 4 bytes may go partly in registers and partly
750
             on the stack.  */
751
          len -= register_size (gdbarch, argreg);
752
          val += register_size (gdbarch, argreg);
753
        }
754
    }
755
 
756
  /* Finally, update the SP register.  */
757
  regcache_cooked_write_unsigned (regcache, M32R_SP_REGNUM, sp);
758
 
759
  return sp;
760
}
761
 
762
 
763
/* Given a return value in `regbuf' with a type `valtype',
764
   extract and copy its value into `valbuf'.  */
765
 
766
static void
767
m32r_extract_return_value (struct type *type, struct regcache *regcache,
768
                           void *dst)
769
{
770
  bfd_byte *valbuf = dst;
771
  int len = TYPE_LENGTH (type);
772
  ULONGEST tmp;
773
 
774
  /* By using store_unsigned_integer we avoid having to do
775
     anything special for small big-endian values.  */
776
  regcache_cooked_read_unsigned (regcache, RET1_REGNUM, &tmp);
777
  store_unsigned_integer (valbuf, (len > 4 ? len - 4 : len), tmp);
778
 
779
  /* Ignore return values more than 8 bytes in size because the m32r
780
     returns anything more than 8 bytes in the stack. */
781
  if (len > 4)
782
    {
783
      regcache_cooked_read_unsigned (regcache, RET1_REGNUM + 1, &tmp);
784
      store_unsigned_integer (valbuf + len - 4, 4, tmp);
785
    }
786
}
787
 
788
enum return_value_convention
789
m32r_return_value (struct gdbarch *gdbarch, struct type *valtype,
790
                   struct regcache *regcache, gdb_byte *readbuf,
791
                   const gdb_byte *writebuf)
792
{
793
  if (TYPE_LENGTH (valtype) > 8)
794
    return RETURN_VALUE_STRUCT_CONVENTION;
795
  else
796
    {
797
      if (readbuf != NULL)
798
        m32r_extract_return_value (valtype, regcache, readbuf);
799
      if (writebuf != NULL)
800
        m32r_store_return_value (valtype, regcache, writebuf);
801
      return RETURN_VALUE_REGISTER_CONVENTION;
802
    }
803
}
804
 
805
 
806
 
807
static CORE_ADDR
808
m32r_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
809
{
810
  return frame_unwind_register_unsigned (next_frame, M32R_PC_REGNUM);
811
}
812
 
813
/* Given a GDB frame, determine the address of the calling function's
814
   frame.  This will be used to create a new GDB frame struct.  */
815
 
816
static void
817
m32r_frame_this_id (struct frame_info *next_frame,
818
                    void **this_prologue_cache, struct frame_id *this_id)
819
{
820
  struct m32r_unwind_cache *info
821
    = m32r_frame_unwind_cache (next_frame, this_prologue_cache);
822
  CORE_ADDR base;
823
  CORE_ADDR func;
824
  struct minimal_symbol *msym_stack;
825
  struct frame_id id;
826
 
827
  /* The FUNC is easy.  */
828
  func = frame_func_unwind (next_frame, NORMAL_FRAME);
829
 
830
  /* Check if the stack is empty.  */
831
  msym_stack = lookup_minimal_symbol ("_stack", NULL, NULL);
832
  if (msym_stack && info->base == SYMBOL_VALUE_ADDRESS (msym_stack))
833
    return;
834
 
835
  /* Hopefully the prologue analysis either correctly determined the
836
     frame's base (which is the SP from the previous frame), or set
837
     that base to "NULL".  */
838
  base = info->prev_sp;
839
  if (base == 0)
840
    return;
841
 
842
  id = frame_id_build (base, func);
843
  (*this_id) = id;
844
}
845
 
846
static void
847
m32r_frame_prev_register (struct frame_info *next_frame,
848
                          void **this_prologue_cache,
849
                          int regnum, int *optimizedp,
850
                          enum lval_type *lvalp, CORE_ADDR *addrp,
851
                          int *realnump, gdb_byte *bufferp)
852
{
853
  struct m32r_unwind_cache *info
854
    = m32r_frame_unwind_cache (next_frame, this_prologue_cache);
855
  trad_frame_get_prev_register (next_frame, info->saved_regs, regnum,
856
                                optimizedp, lvalp, addrp, realnump, bufferp);
857
}
858
 
859
static const struct frame_unwind m32r_frame_unwind = {
860
  NORMAL_FRAME,
861
  m32r_frame_this_id,
862
  m32r_frame_prev_register
863
};
864
 
865
static const struct frame_unwind *
866
m32r_frame_sniffer (struct frame_info *next_frame)
867
{
868
  return &m32r_frame_unwind;
869
}
870
 
871
static CORE_ADDR
872
m32r_frame_base_address (struct frame_info *next_frame, void **this_cache)
873
{
874
  struct m32r_unwind_cache *info
875
    = m32r_frame_unwind_cache (next_frame, this_cache);
876
  return info->base;
877
}
878
 
879
static const struct frame_base m32r_frame_base = {
880
  &m32r_frame_unwind,
881
  m32r_frame_base_address,
882
  m32r_frame_base_address,
883
  m32r_frame_base_address
884
};
885
 
886
/* Assuming NEXT_FRAME->prev is a dummy, return the frame ID of that
887
   dummy frame.  The frame ID's base needs to match the TOS value
888
   saved by save_dummy_frame_tos(), and the PC match the dummy frame's
889
   breakpoint.  */
890
 
891
static struct frame_id
892
m32r_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame)
893
{
894
  return frame_id_build (m32r_unwind_sp (gdbarch, next_frame),
895
                         frame_pc_unwind (next_frame));
896
}
897
 
898
 
899
static gdbarch_init_ftype m32r_gdbarch_init;
900
 
901
static struct gdbarch *
902
m32r_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
903
{
904
  struct gdbarch *gdbarch;
905
  struct gdbarch_tdep *tdep;
906
 
907
  /* If there is already a candidate, use it.  */
908
  arches = gdbarch_list_lookup_by_info (arches, &info);
909
  if (arches != NULL)
910
    return arches->gdbarch;
911
 
912
  /* Allocate space for the new architecture.  */
913
  tdep = XMALLOC (struct gdbarch_tdep);
914
  gdbarch = gdbarch_alloc (&info, tdep);
915
 
916
  set_gdbarch_read_pc (gdbarch, m32r_read_pc);
917
  set_gdbarch_write_pc (gdbarch, m32r_write_pc);
918
  set_gdbarch_unwind_sp (gdbarch, m32r_unwind_sp);
919
 
920
  set_gdbarch_num_regs (gdbarch, M32R_NUM_REGS);
921
  set_gdbarch_sp_regnum (gdbarch, M32R_SP_REGNUM);
922
  set_gdbarch_register_name (gdbarch, m32r_register_name);
923
  set_gdbarch_register_type (gdbarch, m32r_register_type);
924
 
925
  set_gdbarch_push_dummy_call (gdbarch, m32r_push_dummy_call);
926
  set_gdbarch_return_value (gdbarch, m32r_return_value);
927
 
928
  set_gdbarch_skip_prologue (gdbarch, m32r_skip_prologue);
929
  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
930
  set_gdbarch_breakpoint_from_pc (gdbarch, m32r_breakpoint_from_pc);
931
  set_gdbarch_memory_insert_breakpoint (gdbarch,
932
                                        m32r_memory_insert_breakpoint);
933
  set_gdbarch_memory_remove_breakpoint (gdbarch,
934
                                        m32r_memory_remove_breakpoint);
935
 
936
  set_gdbarch_frame_align (gdbarch, m32r_frame_align);
937
 
938
  frame_base_set_default (gdbarch, &m32r_frame_base);
939
 
940
  /* Methods for saving / extracting a dummy frame's ID.  The ID's
941
     stack address must match the SP value returned by
942
     PUSH_DUMMY_CALL, and saved by generic_save_dummy_frame_tos.  */
943
  set_gdbarch_unwind_dummy_id (gdbarch, m32r_unwind_dummy_id);
944
 
945
  /* Return the unwound PC value.  */
946
  set_gdbarch_unwind_pc (gdbarch, m32r_unwind_pc);
947
 
948
  set_gdbarch_print_insn (gdbarch, print_insn_m32r);
949
 
950
  /* Hook in ABI-specific overrides, if they have been registered.  */
951
  gdbarch_init_osabi (info, gdbarch);
952
 
953
  /* Hook in the default unwinders.  */
954
  frame_unwind_append_sniffer (gdbarch, m32r_frame_sniffer);
955
 
956
  /* Support simple overlay manager.  */
957
  set_gdbarch_overlay_update (gdbarch, simple_overlay_update);
958
 
959
  return gdbarch;
960
}
961
 
962
void
963
_initialize_m32r_tdep (void)
964
{
965
  register_gdbarch_init (bfd_arch_m32r, m32r_gdbarch_init);
966
}

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