gdb/mn10300-tdep.c

   1 /* Target-dependent code for the Matsushita MN10300 for GDB, the GNU debugger.
   2
   3    Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free
   4    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 2 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, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 /* MVS Notes:
  24
  25    To get from 1.1 to 1.2, add:
  26    use_struct_convention
  27    store_return_value
  28    extract_return_value
  29    extract_struct_value_address
  30
  31    Make sure to use regcache.  */
  32
  33 /* MVS Notes:
  34
  35    Apparently cannot run without a stub placeholder for unwind_dummy_id.
  36 */
  37
  38 /* MVS Notes:
  39
  40    To get from 1.2 to 1.3, add:
  41    read_pc, write_pc
  42    frame_unwind_init
  43    struct mn10300_unwind_cache
  44    unwind_pc
  45    unwind_dummy_id
  46    frame_this_id
  47    frame_prev_register
  48    frame_sniffer (struct mn10300_frame_unwind)
  49 */
  50
  51 #include "defs.h"
  52 #include "arch-utils.h"
  53 #include "dis-asm.h"
  54 #include "gdbtypes.h"
  55 #include "regcache.h"
  56 #include "gdb_string.h"
  57 #include "gdb_assert.h"
  58 #include "gdbcore.h"    /* for write_memory_unsigned_integer */
  59 #include "value.h"
  60 #include "gdbtypes.h"
  61 #include "frame.h"
  62 #include "frame-unwind.h"
  63 #include "frame-base.h"
  64 #include "trad-frame.h"
  65 #include "symtab.h"
  66 #include "dwarf2-frame.h"
  67 #include "regcache.h"
  68
  69 #include "mn10300-tdep.h"
  70
  71
  72 /* Compute the alignment required by a type.  */
  73
  74 static int
  75 mn10300_type_align (struct type *type)
  76 {
  77   int i, align = 1;
  78
  79   switch (TYPE_CODE (type))
  80     {
  81     case TYPE_CODE_INT:
  82     case TYPE_CODE_ENUM:
  83     case TYPE_CODE_SET:
  84     case TYPE_CODE_RANGE:
  85     case TYPE_CODE_CHAR:
  86     case TYPE_CODE_BOOL:
  87     case TYPE_CODE_FLT:
  88     case TYPE_CODE_PTR:
  89     case TYPE_CODE_REF:
  90       return TYPE_LENGTH (type);
  91
  92     case TYPE_CODE_COMPLEX:
  93       return TYPE_LENGTH (type) / 2;
  94
  95     case TYPE_CODE_STRUCT:
  96     case TYPE_CODE_UNION:
  97       for (i = 0; i < TYPE_NFIELDS (type); i++)
  98         {
  99           int falign = mn10300_type_align (TYPE_FIELD_TYPE (type, i));
 100           while (align < falign)
 101             align <<= 1;
 102         }
 103       return align;
 104
 105     case TYPE_CODE_ARRAY:
 106       /* HACK!  Structures containing arrays, even small ones, are not
 107          elligible for returning in registers.  */
 108       return 256;
 109
 110     case TYPE_CODE_TYPEDEF:
 111       return mn10300_type_align (check_typedef (type));
 112
 113     default:
 114       internal_error (__FILE__, __LINE__, _("bad switch"));
 115     }
 116 }
 117
 118 /* MVS note this is deprecated.  */
 119 /* Should call_function allocate stack space for a struct return?  */
 120 /* gcc_p unused */
 121 static int
 122 mn10300_use_struct_convention (int gcc_p, struct type *type)
 123 {
 124   /* Structures bigger than a pair of words can't be returned in
 125      registers.  */
 126   if (TYPE_LENGTH (type) > 8)
 127     return 1;
 128
 129   switch (TYPE_CODE (type))
 130     {
 131     case TYPE_CODE_STRUCT:
 132     case TYPE_CODE_UNION:
 133       /* Structures with a single field are handled as the field
 134          itself.  */
 135       if (TYPE_NFIELDS (type) == 1)
 136         return mn10300_use_struct_convention (gcc_p,
 137                                               TYPE_FIELD_TYPE (type, 0));
 138
 139       /* Structures with word or double-word size are passed in memory, as
 140          long as they require at least word alignment.  */
 141       if (mn10300_type_align (type) >= 4)
 142         return 0;
 143
 144       return 1;
 145
 146       /* Arrays are addressable, so they're never returned in
 147          registers.  This condition can only hold when the array is
 148          the only field of a struct or union.  */
 149     case TYPE_CODE_ARRAY:
 150       return 1;
 151
 152     case TYPE_CODE_TYPEDEF:
 153       return mn10300_use_struct_convention (gcc_p, check_typedef (type));
 154
 155     default:
 156       return 0;
 157     }
 158 }
 159
 160 /* MVS note this is deprecated.  */
 161 static void
 162 mn10300_store_return_value (struct type *type,
 163                             struct regcache *regcache, const void *valbuf)
 164 {
 165   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 166   int len = TYPE_LENGTH (type);
 167   int reg, regsz;
 168
 169   if (TYPE_CODE (type) == TYPE_CODE_PTR)
 170     reg = 4;
 171   else
 172     reg = 0;
 173
 174   regsz = register_size (gdbarch, reg);
 175
 176   if (len <= regsz)
 177     regcache_raw_write_part (regcache, reg, 0, len, valbuf);
 178   else if (len <= 2 * regsz)
 179     {
 180       regcache_raw_write (regcache, reg, valbuf);
 181       gdb_assert (regsz == register_size (gdbarch, reg + 1));
 182       regcache_raw_write_part (regcache, reg+1, 0,
 183                                len - regsz, (char *) valbuf + regsz);
 184     }
 185   else
 186     internal_error (__FILE__, __LINE__,
 187                     _("Cannot store return value %d bytes long."), len);
 188 }
 189
 190 /* MVS note deprecated.  */
 191 static void
 192 mn10300_extract_return_value (struct type *type,
 193                               struct regcache *regcache, void *valbuf)
 194 {
 195   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 196   char buf[MAX_REGISTER_SIZE];
 197   int len = TYPE_LENGTH (type);
 198   int reg, regsz;
 199
 200   if (TYPE_CODE (type) == TYPE_CODE_PTR)
 201     reg = 4;
 202   else
 203     reg = 0;
 204
 205   regsz = register_size (gdbarch, reg);
 206   if (len <= regsz)
 207     {
 208       regcache_raw_read (regcache, reg, buf);
 209       memcpy (valbuf, buf, len);
 210     }
 211   else if (len <= 2 * regsz)
 212     {
 213       regcache_raw_read (regcache, reg, buf);
 214       memcpy (valbuf, buf, regsz);
 215       gdb_assert (regsz == register_size (gdbarch, reg + 1));
 216       regcache_raw_read (regcache, reg + 1, buf);
 217       memcpy ((char *) valbuf + regsz, buf, len - regsz);
 218     }
 219   else
 220     internal_error (__FILE__, __LINE__,
 221                     _("Cannot extract return value %d bytes long."), len);
 222 }
 223
 224 static char *
 225 register_name (int reg, char **regs, long sizeof_regs)
 226 {
 227   if (reg < 0 || reg >= sizeof_regs / sizeof (regs[0]))
 228     return NULL;
 229   else
 230     return regs[reg];
 231 }
 232
 233 static const char *
 234 mn10300_generic_register_name (int reg)
 235 {
 236   static char *regs[] =
 237   { "d0", "d1", "d2", "d3", "a0", "a1", "a2", "a3",
 238     "sp", "pc", "mdr", "psw", "lir", "lar", "", "",
 239     "", "", "", "", "", "", "", "",
 240     "", "", "", "", "", "", "", "fp"
 241   };
 242   return register_name (reg, regs, sizeof regs);
 243 }
 244
 245
 246 static const char *
 247 am33_register_name (int reg)
 248 {
 249   static char *regs[] =
 250   { "d0", "d1", "d2", "d3", "a0", "a1", "a2", "a3",
 251     "sp", "pc", "mdr", "psw", "lir", "lar", "",
 252     "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
 253     "ssp", "msp", "usp", "mcrh", "mcrl", "mcvf", "", "", ""
 254   };
 255   return register_name (reg, regs, sizeof regs);
 256 }
 257
 258
 259 static struct type *
 260 mn10300_register_type (struct gdbarch *gdbarch, int reg)
 261 {
 262   return builtin_type_int;
 263 }
 264
 265 static CORE_ADDR
 266 mn10300_read_pc (ptid_t ptid)
 267 {
 268   return read_register_pid (E_PC_REGNUM, ptid);
 269 }
 270
 271 static void
 272 mn10300_write_pc (CORE_ADDR val, ptid_t ptid)
 273 {
 274   return write_register_pid (E_PC_REGNUM, val, ptid);
 275 }
 276
 277 /* The breakpoint instruction must be the same size as the smallest
 278    instruction in the instruction set.
 279
 280    The Matsushita mn10x00 processors have single byte instructions
 281    so we need a single byte breakpoint.  Matsushita hasn't defined
 282    one, so we defined it ourselves.  */
 283
 284 const static unsigned char *
 285 mn10300_breakpoint_from_pc (CORE_ADDR *bp_addr, int *bp_size)
 286 {
 287   static char breakpoint[] = {0xff};
 288   *bp_size = 1;
 289   return breakpoint;
 290 }
 291
 292 /* Function: skip_prologue
 293    Return the address of the first inst past the prologue of the function.  */
 294
 295 static CORE_ADDR
 296 mn10300_skip_prologue (CORE_ADDR pc)
 297 {
 298 #if 0
 299   CORE_ADDR ret;
 300   /* FIXME: not implemented.  */
 301   /* First approximation, try simply using skip_prologue_using_sal.  */
 302   ret = skip_prologue_using_sal (pc);
 303   return ret ? ret : pc;
 304 #else
 305   return mn10300_analyze_prologue (NULL, NULL, pc);
 306 #endif
 307 }
 308
 309 /* Simple frame_unwind_cache.
 310    This finds the "extra info" for the frame.  */
 311 struct trad_frame_cache *
 312 mn10300_frame_unwind_cache (struct frame_info *next_frame,
 313                             void **this_prologue_cache)
 314 {
 315   struct trad_frame_cache *cache;
 316   CORE_ADDR pc, start, end;
 317
 318   if (*this_prologue_cache)
 319     return (*this_prologue_cache);
 320
 321   cache = trad_frame_cache_zalloc (next_frame);
 322   pc = gdbarch_unwind_pc (current_gdbarch, next_frame);
 323   mn10300_analyze_prologue (next_frame, (void **) &cache, pc);
 324   if (find_pc_partial_function (pc, NULL, &start, &end))
 325     trad_frame_set_id (cache,
 326                        frame_id_build (trad_frame_get_this_base (cache),
 327                                        start));
 328   else
 329     trad_frame_set_id (cache,
 330                        frame_id_build (trad_frame_get_this_base (cache),
 331                                        frame_func_unwind (next_frame)));
 332
 333   (*this_prologue_cache) = cache;
 334   return cache;
 335 }
 336
 337 /* Here is a dummy implementation.  */
 338 static struct frame_id
 339 mn10300_unwind_dummy_id (struct gdbarch *gdbarch,
 340                          struct frame_info *next_frame)
 341 {
 342   return frame_id_build (frame_sp_unwind (next_frame),
 343                          frame_pc_unwind (next_frame));
 344 }
 345
 346 /* Trad frame implementation.  */
 347 static void
 348 mn10300_frame_this_id (struct frame_info *next_frame,
 349                        void **this_prologue_cache,
 350                        struct frame_id *this_id)
 351 {
 352   struct trad_frame_cache *cache =
 353     mn10300_frame_unwind_cache (next_frame, this_prologue_cache);
 354
 355   trad_frame_get_id (cache, this_id);
 356 }
 357
 358 static void
 359 mn10300_frame_prev_register (struct frame_info *next_frame,
 360                              void **this_prologue_cache,
 361                              int regnum, int *optimizedp,
 362                              enum lval_type *lvalp, CORE_ADDR *addrp,
 363                              int *realnump, void *bufferp)
 364 {
 365   struct trad_frame_cache *cache =
 366     mn10300_frame_unwind_cache (next_frame, this_prologue_cache);
 367
 368   trad_frame_get_register (cache, next_frame, regnum, optimizedp,
 369                            lvalp, addrp, realnump, bufferp);
 370   /* Or...
 371   trad_frame_get_prev_register (next_frame, cache->prev_regs, regnum,
 372                            optimizedp, lvalp, addrp, realnump, bufferp);
 373   */
 374 }
 375
 376 static const struct frame_unwind mn10300_frame_unwind = {
 377   NORMAL_FRAME,
 378   mn10300_frame_this_id,
 379   mn10300_frame_prev_register
 380 };
 381
 382 static CORE_ADDR
 383 mn10300_frame_base_address (struct frame_info *next_frame,
 384                             void **this_prologue_cache)
 385 {
 386   struct trad_frame_cache *cache =
 387     mn10300_frame_unwind_cache (next_frame, this_prologue_cache);
 388
 389   return trad_frame_get_this_base (cache);
 390 }
 391
 392 static const struct frame_unwind *
 393 mn10300_frame_sniffer (struct frame_info *next_frame)
 394 {
 395   return &mn10300_frame_unwind;
 396 }
 397
 398 static const struct frame_base mn10300_frame_base = {
 399   &mn10300_frame_unwind,
 400   mn10300_frame_base_address,
 401   mn10300_frame_base_address,
 402   mn10300_frame_base_address
 403 };
 404
 405 static CORE_ADDR
 406 mn10300_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
 407 {
 408   ULONGEST pc;
 409
 410   frame_unwind_unsigned_register (next_frame, E_PC_REGNUM, &pc);
 411   return pc;
 412 }
 413
 414 static CORE_ADDR
 415 mn10300_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame)
 416 {
 417   ULONGEST sp;
 418
 419   frame_unwind_unsigned_register (next_frame, E_SP_REGNUM, &sp);
 420   return sp;
 421 }
 422
 423 static void
 424 mn10300_frame_unwind_init (struct gdbarch *gdbarch)
 425 {
 426   frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer);
 427   frame_unwind_append_sniffer (gdbarch, mn10300_frame_sniffer);
 428   frame_base_set_default (gdbarch, &mn10300_frame_base);
 429   set_gdbarch_unwind_dummy_id (gdbarch, mn10300_unwind_dummy_id);
 430   set_gdbarch_unwind_pc (gdbarch, mn10300_unwind_pc);
 431   set_gdbarch_unwind_sp (gdbarch, mn10300_unwind_sp);
 432 }
 433
 434 /* Function: push_dummy_call
 435  *
 436  * Set up machine state for a target call, including
 437  * function arguments, stack, return address, etc.
 438  *
 439  */
 440
 441 static CORE_ADDR
 442 mn10300_push_dummy_call (struct gdbarch *gdbarch,
 443                          struct value *target_func,
 444                          struct regcache *regcache,
 445                          CORE_ADDR bp_addr,
 446                          int nargs, struct value **args,
 447                          CORE_ADDR sp,
 448                          int struct_return,
 449                          CORE_ADDR struct_addr)
 450 {
 451   const int push_size = register_size (gdbarch, E_PC_REGNUM);
 452   int regs_used;
 453   int len, arg_len;
 454   int stack_offset = 0;
 455   int argnum;
 456   char *val, valbuf[MAX_REGISTER_SIZE];
 457
 458 #if 0
 459   /* FIXME temp, don't handle struct args at all.  */
 460   if (struct_return)
 461     error ("Target doesn't handle struct return");
 462 #endif
 463
 464   /* This should be a nop, but align the stack just in case something
 465      went wrong.  Stacks are four byte aligned on the mn10300.  */
 466   sp &= ~3;
 467
 468   /* Now make space on the stack for the args.
 469
 470      XXX This doesn't appear to handle pass-by-invisible reference
 471      arguments.  */
 472   regs_used = struct_return ? 1 : 0;
 473   for (len = 0, argnum = 0; argnum < nargs; argnum++)
 474     {
 475       arg_len = (TYPE_LENGTH (value_type (args[argnum])) + 3) & ~3;
 476 #if 0
 477       if (TYPE_CODE (value_type (args[argnum])) == TYPE_CODE_STRUCT)
 478         error ("Target does not handle struct args");
 479 #endif
 480       while (regs_used < 2 && arg_len > 0)
 481         {
 482           regs_used++;
 483           arg_len -= push_size;
 484         }
 485       len += arg_len;
 486     }
 487
 488   /* Allocate stack space.  */
 489   sp -= len;
 490
 491   if (struct_return)
 492     {
 493       regs_used = 1;
 494       write_register (E_D0_REGNUM, struct_addr);
 495     }
 496   else
 497     regs_used = 0;
 498
 499   /* Push all arguments onto the stack. */
 500   for (argnum = 0; argnum < nargs; argnum++)
 501     {
 502       /* FIXME what about structs?  Unions?  */
 503       if (TYPE_CODE (value_type (*args)) == TYPE_CODE_STRUCT
 504           && TYPE_LENGTH (value_type (*args)) > 8)
 505         {
 506           /* Change to pointer-to-type.  */
 507           arg_len = push_size;
 508           store_unsigned_integer (valbuf, push_size,
 509                                   VALUE_ADDRESS (*args));
 510           val = &valbuf[0];
 511         }
 512       else
 513         {
 514           arg_len = TYPE_LENGTH (value_type (*args));
 515           val = (char *) value_contents (*args);
 516         }
 517
 518       while (regs_used < 2 && arg_len > 0)
 519         {
 520           write_register (regs_used,
 521                           extract_unsigned_integer (val, push_size));
 522           val += push_size;
 523           arg_len -= push_size;
 524           regs_used++;
 525         }
 526
 527       while (arg_len > 0)
 528         {
 529           write_memory (sp + stack_offset, val, push_size);
 530           arg_len -= push_size;
 531           val += push_size;
 532           stack_offset += push_size;
 533         }
 534
 535       args++;
 536     }
 537
 538   /* Make space for the flushback area.  */
 539   sp -= 8;
 540
 541   /* Push the return address that contains the magic breakpoint.  */
 542   sp -= 4;
 543   write_memory_unsigned_integer (sp, push_size, bp_addr);
 544   /* Update $sp.  */
 545   regcache_cooked_write_unsigned (regcache, E_SP_REGNUM, sp);
 546   return sp;
 547 }
 548
 549
 550 static struct gdbarch *
 551 mn10300_gdbarch_init (struct gdbarch_info info,
 552                       struct gdbarch_list *arches)
 553 {
 554   struct gdbarch *gdbarch;
 555   struct gdbarch_tdep *tdep;
 556
 557   arches = gdbarch_list_lookup_by_info (arches, &info);
 558   if (arches != NULL)
 559     return arches->gdbarch;
 560
 561   tdep = xmalloc (sizeof (struct gdbarch_tdep));
 562   gdbarch = gdbarch_alloc (&info, tdep);
 563
 564   switch (info.bfd_arch_info->mach)
 565     {
 566     case 0:
 567     case bfd_mach_mn10300:
 568       set_gdbarch_register_name (gdbarch, mn10300_generic_register_name);
 569       tdep->am33_mode = 0;
 570       break;
 571     case bfd_mach_am33:
 572       set_gdbarch_register_name (gdbarch, am33_register_name);
 573       tdep->am33_mode = 1;
 574       break;
 575     default:
 576       internal_error (__FILE__, __LINE__,
 577                       _("mn10300_gdbarch_init: Unknown mn10300 variant"));
 578       break;
 579     }
 580
 581   /* Registers.  */
 582   set_gdbarch_num_regs (gdbarch, E_NUM_REGS);
 583   set_gdbarch_register_type (gdbarch, mn10300_register_type);
 584   set_gdbarch_skip_prologue (gdbarch, mn10300_skip_prologue);
 585   set_gdbarch_read_pc (gdbarch, mn10300_read_pc);
 586   set_gdbarch_write_pc (gdbarch, mn10300_write_pc);
 587   set_gdbarch_pc_regnum (gdbarch, E_PC_REGNUM);
 588   set_gdbarch_sp_regnum (gdbarch, E_SP_REGNUM);
 589
 590   /* Stack unwinding.  */
 591   set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
 592   /* Breakpoints.  */
 593   set_gdbarch_breakpoint_from_pc (gdbarch, mn10300_breakpoint_from_pc);
 594   /* decr_pc_after_break? */
 595   /* Disassembly.  */
 596   set_gdbarch_print_insn (gdbarch, print_insn_mn10300);
 597
 598   /* Stage 2 */
 599   /* MVS Note: at least the first one is deprecated!  */
 600   set_gdbarch_deprecated_use_struct_convention (gdbarch,
 601                                                 mn10300_use_struct_convention);
 602   set_gdbarch_store_return_value (gdbarch, mn10300_store_return_value);
 603   set_gdbarch_extract_return_value (gdbarch, mn10300_extract_return_value);
 604
 605   /* Stage 3 -- get target calls working.  */
 606   set_gdbarch_push_dummy_call (gdbarch, mn10300_push_dummy_call);
 607   /* set_gdbarch_return_value (store, extract) */
 608
 609
 610   mn10300_frame_unwind_init (gdbarch);
 611
 612   return gdbarch;
 613 }
 614
 615 /* Dump out the mn10300 specific architecture information. */
 616
 617 static void
 618 mn10300_dump_tdep (struct gdbarch *current_gdbarch, struct ui_file *file)
 619 {
 620   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
 621   fprintf_unfiltered (file, "mn10300_dump_tdep: am33_mode = %d\n",
 622                       tdep->am33_mode);
 623 }
 624
 625 void
 626 _initialize_mn10300_tdep (void)
 627 {
 628   gdbarch_register (bfd_arch_mn10300, mn10300_gdbarch_init, mn10300_dump_tdep);
 629 }
 630