gdb/hppa-tdep.c

   1 /* Machine-dependent code which would otherwise be in inflow.c and core.c,
   2    for GDB, the GNU debugger.  This code is for the HP PA-RISC cpu.
   3    Copyright 1986, 1987, 1989, 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
   4
   5    Contributed by the Center for Software Science at the
   6    University of Utah (pa-gdb-bugs@cs.utah.edu).
   7
   8 This file is part of GDB.
   9
  10 This program is free software; you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation; either version 2 of the License, or
  13 (at your option) any later version.
  14
  15 This program is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with this program; if not, write to the Free Software
  22 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  23
  24 #include "defs.h"
  25 #include "frame.h"
  26 #include "inferior.h"
  27 #include "value.h"
  28
  29 /* For argument passing to the inferior */
  30 #include "symtab.h"
  31
  32 #ifdef USG
  33 #include <sys/types.h>
  34 #endif
  35
  36 #include <sys/param.h>
  37 #include <sys/dir.h>
  38 #include <signal.h>
  39 #include <sys/ioctl.h>
  40
  41 #ifdef COFF_ENCAPSULATE
  42 #include "a.out.encap.h"
  43 #else
  44 #include <a.out.h>
  45 #endif
  46 #ifndef N_SET_MAGIC
  47 #define N_SET_MAGIC(exec, val) ((exec).a_magic = (val))
  48 #endif
  49
  50 /*#include <sys/user.h>         After a.out.h  */
  51 #include <sys/file.h>
  52 #include <sys/stat.h>
  53 #include <machine/psl.h>
  54 #include "wait.h"
  55
  56 #include "gdbcore.h"
  57 #include "gdbcmd.h"
  58 #include "target.h"
  59 #include "symfile.h"
  60 #include "objfiles.h"
  61
  62 static int restore_pc_queue PARAMS ((struct frame_saved_regs *fsr));
  63 static int hppa_alignof PARAMS ((struct type *arg));
  64 CORE_ADDR frame_saved_pc PARAMS ((FRAME frame));
  65
  66 \f
  67 /* Routines to extract various sized constants out of hppa
  68    instructions. */
  69
  70 /* This assumes that no garbage lies outside of the lower bits of
  71    value. */
  72
  73 int
  74 sign_extend (val, bits)
  75      unsigned val, bits;
  76 {
  77   return (int)(val >> bits - 1 ? (-1 << bits) | val : val);
  78 }
  79
  80 /* For many immediate values the sign bit is the low bit! */
  81
  82 int
  83 low_sign_extend (val, bits)
  84      unsigned val, bits;
  85 {
  86   return (int)((val & 0x1 ? (-1 << (bits - 1)) : 0) | val >> 1);
  87 }
  88 /* extract the immediate field from a ld{bhw}s instruction */
  89
  90 unsigned
  91 get_field (val, from, to)
  92      unsigned val, from, to;
  93 {
  94   val = val >> 31 - to;
  95   return val & ((1 << 32 - from) - 1);
  96 }
  97
  98 unsigned
  99 set_field (val, from, to, new_val)
 100      unsigned *val, from, to;
 101 {
 102   unsigned mask = ~((1 << (to - from + 1)) << (31 - from));
 103   return *val = *val & mask | (new_val << (31 - from));
 104 }
 105
 106 /* extract a 3-bit space register number from a be, ble, mtsp or mfsp */
 107
 108 extract_3 (word)
 109      unsigned word;
 110 {
 111   return GET_FIELD (word, 18, 18) << 2 | GET_FIELD (word, 16, 17);
 112 }
 113
 114 extract_5_load (word)
 115      unsigned word;
 116 {
 117   return low_sign_extend (word >> 16 & MASK_5, 5);
 118 }
 119
 120 /* extract the immediate field from a st{bhw}s instruction */
 121
 122 int
 123 extract_5_store (word)
 124      unsigned word;
 125 {
 126   return low_sign_extend (word & MASK_5, 5);
 127 }
 128
 129 /* extract the immediate field from a break instruction */
 130
 131 unsigned
 132 extract_5r_store (word)
 133      unsigned word;
 134 {
 135   return (word & MASK_5);
 136 }
 137
 138 /* extract the immediate field from a {sr}sm instruction */
 139
 140 unsigned
 141 extract_5R_store (word)
 142      unsigned word;
 143 {
 144   return (word >> 16 & MASK_5);
 145 }
 146
 147 /* extract an 11 bit immediate field */
 148
 149 int
 150 extract_11 (word)
 151      unsigned word;
 152 {
 153   return low_sign_extend (word & MASK_11, 11);
 154 }
 155
 156 /* extract a 14 bit immediate field */
 157
 158 int
 159 extract_14 (word)
 160      unsigned word;
 161 {
 162   return low_sign_extend (word & MASK_14, 14);
 163 }
 164
 165 /* deposit a 14 bit constant in a word */
 166
 167 unsigned
 168 deposit_14 (opnd, word)
 169      int opnd;
 170      unsigned word;
 171 {
 172   unsigned sign = (opnd < 0 ? 1 : 0);
 173
 174   return word | ((unsigned)opnd << 1 & MASK_14)  | sign;
 175 }
 176
 177 /* extract a 21 bit constant */
 178
 179 int
 180 extract_21 (word)
 181      unsigned word;
 182 {
 183   int val;
 184
 185   word &= MASK_21;
 186   word <<= 11;
 187   val = GET_FIELD (word, 20, 20);
 188   val <<= 11;
 189   val |= GET_FIELD (word, 9, 19);
 190   val <<= 2;
 191   val |= GET_FIELD (word, 5, 6);
 192   val <<= 5;
 193   val |= GET_FIELD (word, 0, 4);
 194   val <<= 2;
 195   val |= GET_FIELD (word, 7, 8);
 196   return sign_extend (val, 21) << 11;
 197 }
 198
 199 /* deposit a 21 bit constant in a word. Although 21 bit constants are
 200    usually the top 21 bits of a 32 bit constant, we assume that only
 201    the low 21 bits of opnd are relevant */
 202
 203 unsigned
 204 deposit_21 (opnd, word)
 205      unsigned opnd, word;
 206 {
 207   unsigned val = 0;
 208
 209   val |= GET_FIELD (opnd, 11 + 14, 11 + 18);
 210   val <<= 2;
 211   val |= GET_FIELD (opnd, 11 + 12, 11 + 13);
 212   val <<= 2;
 213   val |= GET_FIELD (opnd, 11 + 19, 11 + 20);
 214   val <<= 11;
 215   val |= GET_FIELD (opnd, 11 + 1, 11 + 11);
 216   val <<= 1;
 217   val |= GET_FIELD (opnd, 11 + 0, 11 + 0);
 218   return word | val;
 219 }
 220
 221 /* extract a 12 bit constant from branch instructions */
 222
 223 int
 224 extract_12 (word)
 225      unsigned word;
 226 {
 227   return sign_extend (GET_FIELD (word, 19, 28) |
 228                       GET_FIELD (word, 29, 29) << 10 |
 229                       (word & 0x1) << 11, 12) << 2;
 230 }
 231
 232 /* extract a 17 bit constant from branch instructions, returning the
 233    19 bit signed value. */
 234
 235 int
 236 extract_17 (word)
 237      unsigned word;
 238 {
 239   return sign_extend (GET_FIELD (word, 19, 28) |
 240                       GET_FIELD (word, 29, 29) << 10 |
 241                       GET_FIELD (word, 11, 15) << 11 |
 242                       (word & 0x1) << 16, 17) << 2;
 243 }
 244 \f
 245 static int use_unwind = 0;
 246
 247 /* Lookup the unwind (stack backtrace) info for the given PC.  We search all
 248    of the objfiles seeking the unwind table entry for this PC.  Each objfile
 249    contains a sorted list of struct unwind_table_entry.  Since we do a binary
 250    search of the unwind tables, we depend upon them to be sorted.  */
 251
 252 static struct unwind_table_entry *
 253 find_unwind_entry(pc)
 254      CORE_ADDR pc;
 255 {
 256   int first, middle, last;
 257   struct objfile *objfile;
 258
 259   ALL_OBJFILES (objfile)
 260     {
 261       struct obj_unwind_info *ui;
 262
 263       ui = OBJ_UNWIND_INFO (objfile);
 264
 265       if (!ui)
 266         continue;
 267
 268       /* First, check the cache */
 269
 270       if (ui->cache
 271           && pc >= ui->cache->region_start
 272           && pc <= ui->cache->region_end)
 273         return ui->cache;
 274
 275       /* Not in the cache, do a binary search */
 276
 277       first = 0;
 278       last = ui->last;
 279
 280       while (first <= last)
 281         {
 282           middle = (first + last) / 2;
 283           if (pc >= ui->table[middle].region_start
 284               && pc <= ui->table[middle].region_end)
 285             {
 286               ui->cache = &ui->table[middle];
 287               return &ui->table[middle];
 288             }
 289
 290           if (pc < ui->table[middle].region_start)
 291             last = middle - 1;
 292           else
 293             first = middle + 1;
 294         }
 295     }                           /* ALL_OBJFILES() */
 296   return NULL;
 297 }
 298
 299 /* Called when no unwind descriptor was found for PC.  Returns 1 if it
 300    appears that PC is in a linker stub.  */
 301 static int pc_in_linker_stub PARAMS ((CORE_ADDR));
 302
 303 static int
 304 pc_in_linker_stub (pc)
 305      CORE_ADDR pc;
 306 {
 307   int found_magic_instruction = 0;
 308   int i;
 309   char buf[4];
 310
 311   /* If unable to read memory, assume pc is not in a linker stub.  */
 312   if (target_read_memory (pc, buf, 4) != 0)
 313     return 0;
 314
 315   /* We are looking for something like
 316
 317      ; $$dyncall jams RP into this special spot in the frame (RP')
 318      ; before calling the "call stub"
 319      ldw     -18(sp),rp
 320
 321      ldsid   (rp),r1         ; Get space associated with RP into r1
 322      mtsp    r1,sp           ; Move it into space register 0
 323      be,n    0(sr0),rp)      ; back to your regularly scheduled program
 324      */
 325
 326   /* Maximum known linker stub size is 4 instructions.  Search forward
 327      from the given PC, then backward.  */
 328   for (i = 0; i < 4; i++)
 329     {
 330       /* If we hit something with an unwind, stop searching this direction.
 331
 332       if (find_unwind_entry (pc + i * 4) != 0)
 333         break;
 334
 335       /* Check for ldsid (rp),r1 which is the magic instruction for a
 336          return from a cross-space function call.  */
 337       if (read_memory_integer (pc + i * 4, 4) == 0x004010a1)
 338         {
 339           found_magic_instruction = 1;
 340           break;
 341         }
 342       /* Add code to handle long call/branch and argument relocation stubs
 343          here.  */
 344     }
 345
 346   if (found_magic_instruction != 0)
 347     return 1;
 348
 349   /* Now look backward.  */
 350   for (i = 0; i < 4; i++)
 351     {
 352       /* If we hit something with an unwind, stop searching this direction.
 353
 354       if (find_unwind_entry (pc - i * 4) != 0)
 355         break;
 356
 357       /* Check for ldsid (rp),r1 which is the magic instruction for a
 358          return from a cross-space function call.  */
 359       if (read_memory_integer (pc - i * 4, 4) == 0x004010a1)
 360         {
 361           found_magic_instruction = 1;
 362           break;
 363         }
 364       /* Add code to handle long call/branch and argument relocation stubs
 365          here.  */
 366     }
 367   return found_magic_instruction;
 368 }
 369
 370 static int
 371 find_return_regnum(pc)
 372      CORE_ADDR pc;
 373 {
 374   struct unwind_table_entry *u;
 375
 376   u = find_unwind_entry (pc);
 377
 378   if (!u)
 379     return RP_REGNUM;
 380
 381   if (u->Millicode)
 382     return 31;
 383
 384   return RP_REGNUM;
 385 }
 386
 387 /* Return size of frame, or -1 if we should use a frame pointer.  */
 388 int
 389 find_proc_framesize(pc)
 390      CORE_ADDR pc;
 391 {
 392   struct unwind_table_entry *u;
 393
 394   if (!use_unwind)
 395     return -1;
 396
 397   u = find_unwind_entry (pc);
 398
 399   if (!u)
 400     {
 401       if (pc_in_linker_stub (pc))
 402         /* Linker stubs have a zero size frame.  */
 403         return 0;
 404       else
 405         return -1;
 406     }
 407
 408   if (u->Save_SP)
 409     /* If this bit is set, it means there is a frame pointer and we should
 410        use it.  */
 411     return -1;
 412
 413   return u->Total_frame_size << 3;
 414 }
 415
 416 /* Return offset from sp at which rp is saved, or 0 if not saved.  */
 417 static int rp_saved PARAMS ((CORE_ADDR));
 418
 419 static int
 420 rp_saved (pc)
 421      CORE_ADDR pc;
 422 {
 423   struct unwind_table_entry *u;
 424
 425   u = find_unwind_entry (pc);
 426
 427   if (!u)
 428     {
 429       if (pc_in_linker_stub (pc))
 430         /* This is the so-called RP'.  */
 431         return -24;
 432       else
 433         return 0;
 434     }
 435
 436   if (u->Save_RP)
 437     return -20;
 438   else
 439     return 0;
 440 }
 441 \f
 442 int
 443 frameless_function_invocation (frame)
 444      FRAME frame;
 445 {
 446
 447   if (use_unwind)
 448     {
 449       struct unwind_table_entry *u;
 450
 451       u = find_unwind_entry (frame->pc);
 452
 453       if (u == 0)
 454         return 0;
 455
 456       return (u->Total_frame_size == 0);
 457     }
 458   else
 459     return frameless_look_for_prologue (frame);
 460 }
 461
 462 CORE_ADDR
 463 saved_pc_after_call (frame)
 464      FRAME frame;
 465 {
 466   int ret_regnum;
 467
 468   ret_regnum = find_return_regnum (get_frame_pc (frame));
 469
 470   return read_register (ret_regnum) & ~0x3;
 471 }
 472 \f
 473 CORE_ADDR
 474 frame_saved_pc (frame)
 475      FRAME frame;
 476 {
 477   CORE_ADDR pc = get_frame_pc (frame);
 478
 479   if (frameless_function_invocation (frame))
 480     {
 481       int ret_regnum;
 482
 483       ret_regnum = find_return_regnum (pc);
 484
 485       return read_register (ret_regnum) & ~0x3;
 486     }
 487   else
 488     {
 489       int rp_offset = rp_saved (pc);
 490
 491       if (rp_offset == 0)
 492         return read_register (RP_REGNUM) & ~0x3;
 493       else
 494         return read_memory_integer (frame->frame + rp_offset, 4) & ~0x3;
 495     }
 496 }
 497 \f
 498 /* We need to correct the PC and the FP for the outermost frame when we are
 499    in a system call.  */
 500
 501 void
 502 init_extra_frame_info (fromleaf, frame)
 503      int fromleaf;
 504      struct frame_info *frame;
 505 {
 506   int flags;
 507   int framesize;
 508
 509   if (frame->next)              /* Only do this for outermost frame */
 510     return;
 511
 512   flags = read_register (FLAGS_REGNUM);
 513   if (flags & 2)        /* In system call? */
 514     frame->pc = read_register (31) & ~0x3;
 515
 516   /* The outermost frame is always derived from PC-framesize */
 517   framesize = find_proc_framesize(frame->pc);
 518   if (framesize == -1)
 519     frame->frame = read_register (FP_REGNUM);
 520   else
 521     frame->frame = read_register (SP_REGNUM) - framesize;
 522
 523   if (!frameless_function_invocation (frame)) /* Frameless? */
 524     return;                                 /* No, quit now */
 525
 526   /* For frameless functions, we need to look at the caller's frame */
 527   framesize = find_proc_framesize(FRAME_SAVED_PC(frame));
 528   if (framesize != -1)
 529     frame->frame -= framesize;
 530 }
 531 \f
 532 FRAME_ADDR
 533 frame_chain (frame)
 534      struct frame_info *frame;
 535 {
 536   int framesize;
 537
 538   framesize = find_proc_framesize(FRAME_SAVED_PC(frame));
 539
 540   if (framesize != -1)
 541     return frame->frame - framesize;
 542
 543   return read_memory_integer (frame->frame, 4);
 544 }
 545 \f
 546 /* To see if a frame chain is valid, see if the caller looks like it
 547    was compiled with gcc. */
 548
 549 int
 550 frame_chain_valid (chain, thisframe)
 551      FRAME_ADDR chain;
 552      FRAME thisframe;
 553 {
 554   struct minimal_symbol *msym;
 555
 556   if (!chain)
 557     return 0;
 558
 559   if (use_unwind)
 560     {
 561
 562       struct unwind_table_entry *u;
 563
 564       u = find_unwind_entry (thisframe->pc);
 565
 566       if (u == NULL)
 567         /* FIXME, we should probably fall back to some other technique,
 568            if we want to deal gracefully with stripped executables or others
 569            without unwind info.  */
 570         return 0;
 571
 572       if (u->Save_SP || u->Total_frame_size)
 573         return 1;
 574
 575       if (pc_in_linker_stub (thisframe->pc))
 576         return 1;
 577
 578       return 0;
 579     }
 580   else
 581     {
 582       msym = lookup_minimal_symbol_by_pc (FRAME_SAVED_PC (thisframe));
 583
 584       if (msym
 585           && (strcmp (SYMBOL_NAME (msym), "_start") == 0))
 586         return 0;
 587       else
 588         return 1;
 589     }
 590 }
 591
 592 /*
 593  * These functions deal with saving and restoring register state
 594  * around a function call in the inferior. They keep the stack
 595  * double-word aligned; eventually, on an hp700, the stack will have
 596  * to be aligned to a 64-byte boundary.
 597  */
 598
 599 int
 600 push_dummy_frame ()
 601 {
 602   register CORE_ADDR sp;
 603   register int regnum;
 604   int int_buffer;
 605   double freg_buffer;
 606
 607   /* Space for "arguments"; the RP goes in here. */
 608   sp = read_register (SP_REGNUM) + 48;
 609   int_buffer = read_register (RP_REGNUM) | 0x3;
 610   write_memory (sp - 20, (char *)&int_buffer, 4);
 611
 612   int_buffer = read_register (FP_REGNUM);
 613   write_memory (sp, (char *)&int_buffer, 4);
 614
 615   write_register (FP_REGNUM, sp);
 616
 617   sp += 8;
 618
 619   for (regnum = 1; regnum < 32; regnum++)
 620     if (regnum != RP_REGNUM && regnum != FP_REGNUM)
 621       sp = push_word (sp, read_register (regnum));
 622
 623   sp += 4;
 624
 625   for (regnum = FP0_REGNUM; regnum < NUM_REGS; regnum++)
 626     {
 627       read_register_bytes (REGISTER_BYTE (regnum), (char *)&freg_buffer, 8);
 628       sp = push_bytes (sp, (char *)&freg_buffer, 8);
 629     }
 630   sp = push_word (sp, read_register (IPSW_REGNUM));
 631   sp = push_word (sp, read_register (SAR_REGNUM));
 632   sp = push_word (sp, read_register (PCOQ_HEAD_REGNUM));
 633   sp = push_word (sp, read_register (PCSQ_HEAD_REGNUM));
 634   sp = push_word (sp, read_register (PCOQ_TAIL_REGNUM));
 635   sp = push_word (sp, read_register (PCSQ_TAIL_REGNUM));
 636   write_register (SP_REGNUM, sp);
 637 }
 638
 639 find_dummy_frame_regs (frame, frame_saved_regs)
 640      struct frame_info *frame;
 641      struct frame_saved_regs *frame_saved_regs;
 642 {
 643   CORE_ADDR fp = frame->frame;
 644   int i;
 645
 646   frame_saved_regs->regs[RP_REGNUM] = fp - 20 & ~0x3;
 647   frame_saved_regs->regs[FP_REGNUM] = fp;
 648   frame_saved_regs->regs[1] = fp + 8;
 649
 650   for (fp += 12, i = 3; i < 32; i++)
 651     {
 652       if (i != FP_REGNUM)
 653         {
 654           frame_saved_regs->regs[i] = fp;
 655           fp += 4;
 656         }
 657     }
 658
 659   fp += 4;
 660   for (i = FP0_REGNUM; i < NUM_REGS; i++, fp += 8)
 661     frame_saved_regs->regs[i] = fp;
 662
 663   frame_saved_regs->regs[IPSW_REGNUM] = fp;
 664   frame_saved_regs->regs[SAR_REGNUM] = fp + 4;
 665   frame_saved_regs->regs[PCOQ_HEAD_REGNUM] = fp + 8;
 666   frame_saved_regs->regs[PCSQ_HEAD_REGNUM] = fp + 12;
 667   frame_saved_regs->regs[PCOQ_TAIL_REGNUM] = fp + 16;
 668   frame_saved_regs->regs[PCSQ_TAIL_REGNUM] = fp + 20;
 669 }
 670
 671 int
 672 hppa_pop_frame ()
 673 {
 674   register FRAME frame = get_current_frame ();
 675   register CORE_ADDR fp;
 676   register int regnum;
 677   struct frame_saved_regs fsr;
 678   struct frame_info *fi;
 679   double freg_buffer;
 680
 681   fi = get_frame_info (frame);
 682   fp = fi->frame;
 683   get_frame_saved_regs (fi, &fsr);
 684
 685   if (fsr.regs[IPSW_REGNUM])    /* Restoring a call dummy frame */
 686     restore_pc_queue (&fsr);
 687
 688   for (regnum = 31; regnum > 0; regnum--)
 689     if (fsr.regs[regnum])
 690       write_register (regnum, read_memory_integer (fsr.regs[regnum], 4));
 691
 692   for (regnum = NUM_REGS - 1; regnum >= FP0_REGNUM ; regnum--)
 693     if (fsr.regs[regnum])
 694       {
 695         read_memory (fsr.regs[regnum], (char *)&freg_buffer, 8);
 696         write_register_bytes (REGISTER_BYTE (regnum), (char *)&freg_buffer, 8);
 697       }
 698
 699   if (fsr.regs[IPSW_REGNUM])
 700     write_register (IPSW_REGNUM,
 701                     read_memory_integer (fsr.regs[IPSW_REGNUM], 4));
 702
 703   if (fsr.regs[SAR_REGNUM])
 704     write_register (SAR_REGNUM,
 705                     read_memory_integer (fsr.regs[SAR_REGNUM], 4));
 706
 707   if (fsr.regs[PCOQ_TAIL_REGNUM])
 708     write_register (PCOQ_TAIL_REGNUM,
 709                     read_memory_integer (fsr.regs[PCOQ_TAIL_REGNUM], 4));
 710
 711   write_register (FP_REGNUM, read_memory_integer (fp, 4));
 712
 713   if (fsr.regs[IPSW_REGNUM])    /* call dummy */
 714     write_register (SP_REGNUM, fp - 48);
 715   else
 716     write_register (SP_REGNUM, fp);
 717
 718   flush_cached_frames ();
 719   set_current_frame (create_new_frame (read_register (FP_REGNUM),
 720                                        read_pc ()));
 721 }
 722
 723 /*
 724  * After returning to a dummy on the stack, restore the instruction
 725  * queue space registers. */
 726
 727 static int
 728 restore_pc_queue (fsr)
 729      struct frame_saved_regs *fsr;
 730 {
 731   CORE_ADDR pc = read_pc ();
 732   CORE_ADDR new_pc = read_memory_integer (fsr->regs[PCOQ_HEAD_REGNUM], 4);
 733   int pid;
 734   WAITTYPE w;
 735   int insn_count;
 736
 737   /* Advance past break instruction in the call dummy. */
 738   write_register (PCOQ_HEAD_REGNUM, pc + 4);
 739   write_register (PCOQ_TAIL_REGNUM, pc + 8);
 740
 741   /*
 742    * HPUX doesn't let us set the space registers or the space
 743    * registers of the PC queue through ptrace. Boo, hiss.
 744    * Conveniently, the call dummy has this sequence of instructions
 745    * after the break:
 746    *    mtsp r21, sr0
 747    *    ble,n 0(sr0, r22)
 748    *
 749    * So, load up the registers and single step until we are in the
 750    * right place.
 751    */
 752
 753   write_register (21, read_memory_integer (fsr->regs[PCSQ_HEAD_REGNUM], 4));
 754   write_register (22, new_pc);
 755
 756   for (insn_count = 0; insn_count < 3; insn_count++)
 757     {
 758       resume (1, 0);
 759       target_wait(&w);
 760
 761       if (!WIFSTOPPED (w))
 762         {
 763           stop_signal = WTERMSIG (w);
 764           terminal_ours_for_output ();
 765           printf ("\nProgram terminated with signal %d, %s\n",
 766                   stop_signal, safe_strsignal (stop_signal));
 767           fflush (stdout);
 768           return 0;
 769         }
 770     }
 771   fetch_inferior_registers (-1);
 772   return 1;
 773 }
 774
 775 CORE_ADDR
 776 hppa_push_arguments (nargs, args, sp, struct_return, struct_addr)
 777      int nargs;
 778      value *args;
 779      CORE_ADDR sp;
 780      int struct_return;
 781      CORE_ADDR struct_addr;
 782 {
 783   /* array of arguments' offsets */
 784   int *offset = (int *)alloca(nargs * sizeof (int));
 785   int cum = 0;
 786   int i, alignment;
 787
 788   for (i = 0; i < nargs; i++)
 789     {
 790       /* Coerce chars to int & float to double if necessary */
 791       args[i] = value_arg_coerce (args[i]);
 792
 793       cum += TYPE_LENGTH (VALUE_TYPE (args[i]));
 794
 795     /* value must go at proper alignment. Assume alignment is a
 796          power of two.*/
 797       alignment = hppa_alignof (VALUE_TYPE (args[i]));
 798       if (cum % alignment)
 799         cum = (cum + alignment) & -alignment;
 800       offset[i] = -cum;
 801     }
 802   sp += max ((cum + 7) & -8, 16);
 803
 804   for (i = 0; i < nargs; i++)
 805     write_memory (sp + offset[i], VALUE_CONTENTS (args[i]),
 806                   TYPE_LENGTH (VALUE_TYPE (args[i])));
 807
 808   if (struct_return)
 809     write_register (28, struct_addr);
 810   return sp + 32;
 811 }
 812
 813 /*
 814  * Insert the specified number of args and function address
 815  * into a call sequence of the above form stored at DUMMYNAME.
 816  *
 817  * On the hppa we need to call the stack dummy through $$dyncall.
 818  * Therefore our version of FIX_CALL_DUMMY takes an extra argument,
 819  * real_pc, which is the location where gdb should start up the
 820  * inferior to do the function call.
 821  */
 822
 823 CORE_ADDR
 824 hppa_fix_call_dummy (dummy, pc, fun, nargs, args, type, gcc_p)
 825      REGISTER_TYPE *dummy;
 826      CORE_ADDR pc;
 827      CORE_ADDR fun;
 828      int nargs;
 829      value *args;
 830      struct type *type;
 831      int gcc_p;
 832 {
 833   CORE_ADDR dyncall_addr, sr4export_addr;
 834   struct minimal_symbol *msymbol;
 835
 836   msymbol = lookup_minimal_symbol ("$$dyncall", (struct objfile *) NULL);
 837   if (msymbol == NULL)
 838     error ("Can't find an address for $$dyncall trampoline");
 839
 840   dyncall_addr = SYMBOL_VALUE_ADDRESS (msymbol);
 841
 842   msymbol = lookup_minimal_symbol ("_sr4export", (struct objfile *) NULL);
 843   if (msymbol == NULL)
 844     error ("Can't find an address for _sr4export trampoline");
 845
 846   sr4export_addr = SYMBOL_VALUE_ADDRESS (msymbol);
 847
 848   dummy[9] = deposit_21 (fun >> 11, dummy[9]);
 849   dummy[10] = deposit_14 (fun & MASK_11, dummy[10]);
 850   dummy[12] = deposit_21 (sr4export_addr >> 11, dummy[12]);
 851   dummy[13] = deposit_14 (sr4export_addr & MASK_11, dummy[13]);
 852
 853   write_register (22, pc);
 854
 855   return dyncall_addr;
 856 }
 857
 858 /* return the alignment of a type in bytes. Structures have the maximum
 859    alignment required by their fields. */
 860
 861 static int
 862 hppa_alignof (arg)
 863      struct type *arg;
 864 {
 865   int max_align, align, i;
 866   switch (TYPE_CODE (arg))
 867     {
 868     case TYPE_CODE_PTR:
 869     case TYPE_CODE_INT:
 870     case TYPE_CODE_FLT:
 871       return TYPE_LENGTH (arg);
 872     case TYPE_CODE_ARRAY:
 873       return hppa_alignof (TYPE_FIELD_TYPE (arg, 0));
 874     case TYPE_CODE_STRUCT:
 875     case TYPE_CODE_UNION:
 876       max_align = 2;
 877       for (i = 0; i < TYPE_NFIELDS (arg); i++)
 878         {
 879           /* Bit fields have no real alignment. */
 880           if (!TYPE_FIELD_BITPOS (arg, i))
 881             {
 882               align = hppa_alignof (TYPE_FIELD_TYPE (arg, i));
 883               max_align = max (max_align, align);
 884             }
 885         }
 886       return max_align;
 887     default:
 888       return 4;
 889     }
 890 }
 891
 892 /* Print the register regnum, or all registers if regnum is -1 */
 893
 894 pa_do_registers_info (regnum, fpregs)
 895      int regnum;
 896      int fpregs;
 897 {
 898   char raw_regs [REGISTER_BYTES];
 899   int i;
 900
 901   for (i = 0; i < NUM_REGS; i++)
 902     read_relative_register_raw_bytes (i, raw_regs + REGISTER_BYTE (i));
 903   if (regnum == -1)
 904     pa_print_registers (raw_regs, regnum, fpregs);
 905   else if (regnum < FP0_REGNUM)
 906     printf ("%s %x\n", reg_names[regnum], *(long *)(raw_regs +
 907                                                     REGISTER_BYTE (regnum)));
 908   else
 909     pa_print_fp_reg (regnum);
 910 }
 911
 912 pa_print_registers (raw_regs, regnum, fpregs)
 913      char *raw_regs;
 914      int regnum;
 915      int fpregs;
 916 {
 917   int i;
 918
 919   for (i = 0; i < 18; i++)
 920     printf ("%8.8s: %8x  %8.8s: %8x  %8.8s: %8x  %8.8s: %8x\n",
 921             reg_names[i],
 922             *(int *)(raw_regs + REGISTER_BYTE (i)),
 923             reg_names[i + 18],
 924             *(int *)(raw_regs + REGISTER_BYTE (i + 18)),
 925             reg_names[i + 36],
 926             *(int *)(raw_regs + REGISTER_BYTE (i + 36)),
 927             reg_names[i + 54],
 928             *(int *)(raw_regs + REGISTER_BYTE (i + 54)));
 929
 930   if (fpregs)
 931     for (i = 72; i < NUM_REGS; i++)
 932       pa_print_fp_reg (i);
 933 }
 934
 935 pa_print_fp_reg (i)
 936      int i;
 937 {
 938   unsigned char raw_buffer[MAX_REGISTER_RAW_SIZE];
 939   unsigned char virtual_buffer[MAX_REGISTER_VIRTUAL_SIZE];
 940   REGISTER_TYPE val;
 941
 942   /* Get the data in raw format, then convert also to virtual format.  */
 943   read_relative_register_raw_bytes (i, raw_buffer);
 944   REGISTER_CONVERT_TO_VIRTUAL (i, raw_buffer, virtual_buffer);
 945
 946   fputs_filtered (reg_names[i], stdout);
 947   print_spaces_filtered (15 - strlen (reg_names[i]), stdout);
 948
 949   val_print (REGISTER_VIRTUAL_TYPE (i), virtual_buffer, 0, stdout, 0,
 950              1, 0, Val_pretty_default);
 951   printf_filtered ("\n");
 952 }
 953
 954 /* Function calls that pass into a new compilation unit must pass through a
 955    small piece of code that does long format (`external' in HPPA parlance)
 956    jumps.  We figure out where the trampoline is going to end up, and return
 957    the PC of the final destination.  If we aren't in a trampoline, we just
 958    return NULL.
 959
 960    For computed calls, we just extract the new PC from r22.  */
 961
 962 CORE_ADDR
 963 skip_trampoline_code (pc, name)
 964      CORE_ADDR pc;
 965      char *name;
 966 {
 967   long inst0, inst1;
 968   static CORE_ADDR dyncall = 0;
 969   struct minimal_symbol *msym;
 970
 971 /* FIXME XXX - dyncall must be initialized whenever we get a new exec file */
 972
 973   if (!dyncall)
 974     {
 975       msym = lookup_minimal_symbol ("$$dyncall", NULL);
 976       if (msym)
 977         dyncall = SYMBOL_VALUE_ADDRESS (msym);
 978       else
 979         dyncall = -1;
 980     }
 981
 982   if (pc == dyncall)
 983     return (CORE_ADDR)(read_register (22) & ~0x3);
 984
 985   inst0 = read_memory_integer (pc, 4);
 986   inst1 = read_memory_integer (pc+4, 4);
 987
 988   if (   (inst0 & 0xffe00000) == 0x20200000 /* ldil xxx, r1 */
 989       && (inst1 & 0xffe0e002) == 0xe0202002) /* be,n yyy(sr4, r1) */
 990     pc = extract_21 (inst0) + extract_17 (inst1);
 991   else
 992     pc = (CORE_ADDR)NULL;
 993
 994   return pc;
 995 }
 996
 997 /* Advance PC across any function entry prologue instructions
 998    to reach some "real" code.  */
 999
1000 /* skip (stw rp, -20(0,sp)); copy 4,1; copy sp, 4; stwm 1,framesize(sp)
1001    for gcc, or (stw rp, -20(0,sp); stwm 1, framesize(sp) for hcc */
1002
1003 CORE_ADDR
1004 skip_prologue(pc)
1005      CORE_ADDR pc;
1006 {
1007   char buf[4];
1008   unsigned long inst;
1009   int status;
1010
1011   status = target_read_memory (pc, buf, 4);
1012   inst = extract_unsigned_integer (buf, 4);
1013   if (status != 0)
1014     return pc;
1015
1016   if (inst == 0x6BC23FD9)       /* stw rp,-20(sp) */
1017     {
1018       if (read_memory_integer (pc + 4, 4) == 0x8040241) /* copy r4,r1 */
1019         pc += 16;
1020       else if ((read_memory_integer (pc + 4, 4) & ~MASK_14) == 0x68810000) /* stw r1,(r4) */
1021         pc += 8;
1022     }
1023   else if (read_memory_integer (pc, 4) == 0x8040241) /* copy r4,r1 */
1024     pc += 12;
1025   else if ((read_memory_integer (pc, 4) & ~MASK_14) == 0x68810000) /* stw r1,(r4) */
1026     pc += 4;
1027
1028   return pc;
1029 }
1030
1031 static void
1032 unwind_command (exp, from_tty)
1033      char *exp;
1034      int from_tty;
1035 {
1036   CORE_ADDR address;
1037   union
1038     {
1039       int *foo;
1040       struct unwind_table_entry *u;
1041     } xxx;
1042
1043   /* If we have an expression, evaluate it and use it as the address.  */
1044
1045   if (exp != 0 && *exp != 0)
1046     address = parse_and_eval_address (exp);
1047   else
1048     return;
1049
1050   xxx.u = find_unwind_entry (address);
1051
1052   if (!xxx.u)
1053     {
1054       printf ("Can't find unwind table entry for PC 0x%x\n", address);
1055       return;
1056     }
1057
1058   printf ("%08x\n%08X\n%08X\n%08X\n", xxx.foo[0], xxx.foo[1], xxx.foo[2],
1059           xxx.foo[3]);
1060 }
1061
1062 void
1063 _initialize_hppa_tdep ()
1064 {
1065   add_com ("unwind", class_obscure, unwind_command, "Print unwind info\n");
1066   add_show_from_set
1067     (add_set_cmd ("use_unwind", class_obscure, var_boolean,
1068                   (char *)&use_unwind,
1069                   "Set the usage of unwind info", &setlist),
1070      &showlist);
1071 }