gdb/tm-rs6000.h

   1 /* Parameters for target execution on an RS6000, for GDB, the GNU debugger.
   2    Copyright (C) 1986, 1987, 1989, 1991 Free Software Foundation, Inc.
   3    Contributed by IBM Corporation.
   4
   5 This file is part of GDB.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21
  22 /* A successful ptrace(continue) might return errno != 0 in this particular port
  23    of rs6000. I am not sure why. We will use this kludge and ignore it until
  24    we figure out the real problem. */
  25
  26 #define AIX_BUGGY_PTRACE_CONTINUE       \
  27 { \
  28   int ret = ptrace (PT_CONTINUE, inferior_pid, (int *)1, signal, 0); \
  29   if (errno) { \
  30 /*    printf ("ret: %d, errno: %d, signal: %d\n", ret, errno, signal); */ \
  31     errno = 0; } \
  32 }
  33
  34 extern int      symtab_relocated;
  35
  36 /* Minimum possible text address in AIX */
  37
  38 #define TEXT_SEGMENT_BASE       0x10000000
  39
  40
  41 /* text addresses in a core file does not necessarily match to symbol table,
  42    if symbol table relocation wasn't done yet. */
  43
  44 #define CORE_NEEDS_RELOCATION(PC)       \
  45   if (!symtab_relocated && !inferior_pid && (PC) >  TEXT_SEGMENT_BASE)  \
  46     (PC) -= ( TEXT_SEGMENT_BASE + text_adjustment (exec_bfd));
  47
  48 /* Load segment of a given pc value. */
  49
  50 #define PC_LOAD_SEGMENT(PC)     pc_load_segment_name(PC)
  51
  52
  53 /* Conversion between a register number in stab string to actual register num. */
  54
  55 #define STAB_REG_TO_REGNUM(value)       (value)
  56
  57 /* return true if a given `pc' value is in `call dummy' function. */
  58
  59 #define PC_IN_CALL_DUMMY(STOP_PC, STOP_SP, STOP_FRAME_ADDR)     \
  60         (STOP_SP < STOP_PC && STOP_PC < STACK_END_ADDR)
  61
  62 /* For each symtab, we keep track of which BFD it came from.  */
  63 #define EXTRA_SYMTAB_INFO       \
  64         unsigned    nonreloc:1;         /* TRUE if non relocatable */
  65
  66 #define INIT_EXTRA_SYMTAB_INFO(symtab)  \
  67         symtab->nonreloc = 0;           \
  68
  69 extern unsigned int text_start, data_start;
  70 extern int inferior_pid;
  71 extern char *corefile;
  72
  73 /* setpgrp() messes up controling terminal. The other version of it
  74    requires libbsd.a. */
  75 #define setpgrp(XX,YY)          setpgid (XX, YY)
  76
  77 /* We are missing register descriptions in the system header files. Sigh! */
  78
  79 struct regs {
  80         int     gregs [32];             /* general purpose registers */
  81         int     pc;                     /* program conter       */
  82         int     ps;                     /* processor status, or machine state */
  83 };
  84
  85 struct fp_status {
  86         double  fpregs [32];            /* floating GP registers */
  87 };
  88
  89
  90 /* To be used by function_frame_info. */
  91
  92 struct aix_framedata {
  93   int   offset;                         /* # of bytes in gpr's and fpr's are saved */
  94   int   saved_gpr;                      /* smallest # of saved gpr */
  95   int   saved_fpr;                      /* smallest # of saved fpr */
  96   int   alloca_reg;                     /* alloca register number (frame ptr) */
  97   char  frameless;                      /* true if frameless functions. */
  98 };
  99
 100
 101 /* Define the byte order of the machine.  */
 102
 103 #define TARGET_BYTE_ORDER       BIG_ENDIAN
 104
 105 /* Define this if the C compiler puts an underscore at the front
 106    of external names before giving them to the linker.  */
 107
 108 #undef NAMES_HAVE_UNDERSCORE
 109
 110 /* Offset from address of function to start of its code.
 111    Zero on most machines.  */
 112
 113 #define FUNCTION_START_OFFSET 0
 114
 115 /* Advance PC across any function entry prologue instructions
 116    to reach some "real" code.  */
 117
 118 #define SKIP_PROLOGUE(pc)       pc = skip_prologue (pc)
 119
 120 /* If PC is in some function-call trampoline code, return the PC
 121    where the function itself actually starts.  If not, return NULL.  */
 122
 123 #define SKIP_TRAMPOLINE_CODE(pc)        skip_trampoline_code (pc)
 124
 125 /* When a child process is just starting, we sneak in and relocate
 126    the symbol table (and other stuff) after the dynamic linker has
 127    figured out where they go. But we want to do this relocation just
 128    once. */
 129
 130 extern int aix_loadInfoTextIndex;
 131
 132 #define SOLIB_CREATE_INFERIOR_HOOK(PID) \
 133   do {                                  \
 134     if (aix_loadInfoTextIndex == 0)     \
 135         aixcoff_relocate_symtab (PID);  \
 136   } while (0)
 137
 138
 139 #if 0
 140    The following comment is not correct anymore. AIX has a trap signal
 141    that might be sent with a "stopped after a load" status. This might
 142    show up when the inferior is just started, or anytime inferior
 143    loads something else. It is incorrect to try to skip over it *only* in
 144    startup-time. It always has to be ignored and should not be mixed up
 145    with breakpoint traps. See the macro SIGTRAP_STOP_AFTER_LOAD and its
 146    usage in infrun.c.
 147
 148 /* In aix, number of the trap signals we need to skip over once the
 149    inferior process starts running is different in version 3.1 and 3.2.
 150    This will be 2 for version 3.1x, 3 for version 3.2x. */
 151
 152 #define START_INFERIOR_TRAPS_EXPECTED   aix_starting_inferior_traps ()
 153 #endif /* 0 */
 154
 155 #define START_INFERIOR_TRAPS_EXPECTED   2
 156
 157 /* AIX might return a sigtrap, with a "stop after load" status. It should
 158    be ignored by gdb, shouldn't be mixed up with breakpoint traps. */
 159
 160 #define SIGTRAP_STOP_AFTER_LOAD(W)      \
 161  if ( (W) == 0x57c ) {                  \
 162    if (breakpoints_inserted) {          \
 163      mark_breakpoints_out ();           \
 164      insert_breakpoints ();             \
 165      insert_step_breakpoint ();         \
 166    }                                    \
 167    resume (0, 0);                       \
 168    continue;                            \
 169  }
 170
 171 /* In aixcoff, we cannot process line numbers when we see them. This is
 172    mainly because we don't know the boundaries of the include files. So,
 173    we postpone that, and then enter and sort(?) the whole line table at
 174    once, when we are closing the current symbol table in end_symtab(). */
 175
 176 #define PROCESS_LINENUMBER_HOOK()       aix_process_linenos ()
 177
 178
 179 /* When a target process or core-file has been attached, we sneak in
 180    and figure out where the shared libraries have got to. In case there
 181    is no inferior_process exists (e.g. bringing up a core file), we can't
 182    attemtp to relocate symbol table, since we don't have information about
 183    load segments. */
 184
 185 #define SOLIB_ADD(a, b, c)      \
 186    if (inferior_pid)    aixcoff_relocate_symtab (inferior_pid)
 187
 188 /* Immediately after a function call, return the saved pc.
 189    Can't go through the frames for this because on some machines
 190    the new frame is not set up until the new function executes
 191    some instructions.  */
 192
 193 extern char registers[];
 194 extern char register_valid [];
 195
 196 #define SAVED_PC_AFTER_CALL(frame)      \
 197         (register_valid [LR_REGNUM] ?   \
 198           (*(int*)&registers[REGISTER_BYTE (LR_REGNUM)]) :      \
 199           read_register (LR_REGNUM))
 200
 201 /*#define SAVED_PC_AFTER_CALL(frame)    saved_pc_after_call(frame) */
 202
 203
 204 /* Address of end of stack space.  */
 205
 206 #define STACK_END_ADDR 0x2ff80000
 207
 208 /* Stack grows downward.  */
 209
 210 #define INNER_THAN <
 211
 212 #if 0
 213 /* No, we shouldn't use this. push_arguments() should leave stack in a
 214    proper alignment! */
 215 /* Stack has strict alignment. */
 216
 217 #define STACK_ALIGN(ADDR)       (((ADDR)+7)&-8)
 218 #endif
 219
 220 /* This is how argumets pushed onto stack or passed in registers. */
 221
 222 #define PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \
 223   sp = push_arguments(nargs, args, sp, struct_return, struct_addr)
 224
 225 /* Sequence of bytes for breakpoint instruction.  */
 226
 227 #define BREAKPOINT {0x7d, 0x82, 0x10, 0x08}
 228
 229 /* Amount PC must be decremented by after a breakpoint.
 230    This is often the number of bytes in BREAKPOINT
 231    but not always.  */
 232
 233 #define DECR_PC_AFTER_BREAK 0
 234
 235 /* Nonzero if instruction at PC is a return instruction.  */
 236 /* Allow any of the return instructions, including a trapv and a return
 237    from interrupt.  */
 238
 239 #define ABOUT_TO_RETURN(pc)  \
 240    ((read_memory_integer (pc, 4) & 0xfe8007ff) == 0x4e800020)
 241
 242 /* Return 1 if P points to an invalid floating point value.  */
 243
 244 #define INVALID_FLOAT(p, len) 0   /* Just a first guess; not checked */
 245
 246 /* Largest integer type */
 247
 248 #define LONGEST long
 249
 250 /* Name of the builtin type for the LONGEST type above. */
 251
 252 #define BUILTIN_TYPE_LONGEST builtin_type_long
 253
 254 /* Say how long (ordinary) registers are.  */
 255
 256 #define REGISTER_TYPE long
 257
 258 /* Number of machine registers */
 259
 260 #define NUM_REGS 71
 261
 262 /* Initializer for an array of names of registers.
 263    There should be NUM_REGS strings in this initializer.  */
 264
 265 #define REGISTER_NAMES  \
 266  {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",  \
 267   "r8", "r9", "r10","r11","r12","r13","r14","r15", \
 268   "r16","r17","r18","r19","r20","r21","r22","r23", \
 269   "r24","r25","r26","r27","r28","r29","r30","r31", \
 270   "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",  \
 271   "f8", "f9", "f10","f11","f12","f13","f14","f15", \
 272   "f16","f17","f18","f19","f20","f21","f22","f23", \
 273   "f24","f25","f26","f27","f28","f29","f30","f31", \
 274   "pc", "ps", "cnd", "lr", "cnt", "xer", "mq" }
 275
 276 /* Register numbers of various important registers.
 277    Note that some of these values are "real" register numbers,
 278    and correspond to the general registers of the machine,
 279    and some are "phony" register numbers which are too large
 280    to be actual register numbers as far as the user is concerned
 281    but do serve to get the desired values when passed to read_register.  */
 282
 283 #define FP_REGNUM 1             /* Contains address of executing stack frame */
 284 #define SP_REGNUM 1             /* Contains address of top of stack */
 285 #define TOC_REGNUM 2            /* TOC register */
 286 #define FP0_REGNUM 32           /* Floating point register 0 */
 287 #define GP0_REGNUM 0            /* GPR register 0 */
 288 #define FP0_REGNUM 32           /* FPR (Floating point) register 0 */
 289 #define FPLAST_REGNUM 63        /* Last floating point register */
 290
 291 /* Special purpose registers... */
 292 /* P.S. keep these in the same order as in /usr/mstsave.h `mstsave' structure, for
 293    easier processing */
 294
 295 #define PC_REGNUM 64            /* Program counter (instruction address %iar) */
 296 #define PS_REGNUM 65            /* Processor (or machine) status (%msr) */
 297 #define CR_REGNUM 66            /* Condition register */
 298 #define LR_REGNUM 67            /* Link register */
 299 #define CTR_REGNUM 68           /* Count register */
 300 #define XER_REGNUM 69           /* Fixed point exception registers */
 301 #define MQ_REGNUM 70            /* Multiply/quotient register */
 302
 303 #define FIRST_SP_REGNUM 64      /* first special register number */
 304 #define LAST_SP_REGNUM  70      /* last special register number */
 305
 306 /* Total amount of space needed to store our copies of the machine's
 307    register state, the array `registers'.
 308
 309         32 4-byte gpr's
 310         32 8-byte fpr's
 311         7  4-byte special purpose registers,
 312
 313    total 416 bytes. Keep some extra space for now, in case to add more. */
 314
 315 #define REGISTER_BYTES 420
 316
 317
 318 /* Index within `registers' of the first byte of the space for
 319    register N.  */
 320
 321 #define REGISTER_BYTE(N)  \
 322  (                                                              \
 323   ((N) > FPLAST_REGNUM) ? ((((N) - FPLAST_REGNUM -1) * 4) + 384)\
 324   :((N) >= FP0_REGNUM) ? ((((N) - FP0_REGNUM) * 8) + 128)       \
 325   :((N) * 4) )
 326
 327 /* Number of bytes of storage in the actual machine representation
 328    for register N. */
 329 /* Note that the unsigned cast here forces the result of the
 330    subtractiion to very high positive values if N < FP0_REGNUM */
 331
 332 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
 333
 334 /* Number of bytes of storage in the program's representation
 335    for register N.  On the RS6000, all regs are 4 bytes
 336    except the floating point regs which are 8-byte doubles.  */
 337
 338 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
 339
 340 /* Largest value REGISTER_RAW_SIZE can have.  */
 341
 342 #define MAX_REGISTER_RAW_SIZE 8
 343
 344 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 345
 346 #define MAX_REGISTER_VIRTUAL_SIZE 8
 347
 348 /* convert a dbx stab register number (from `r' declaration) to a gdb REGNUM */
 349
 350 #define STAB_REG_TO_REGNUM(value)       (value)
 351
 352 /* Nonzero if register N requires conversion
 353    from raw format to virtual format.  */
 354
 355 #define REGISTER_CONVERTIBLE(N) ((N) >= FP0_REGNUM && (N) <= FPLAST_REGNUM)
 356
 357 /* Convert data from raw format for register REGNUM
 358    to virtual format for register REGNUM.  */
 359
 360 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO)     \
 361    bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM))
 362
 363 /* Convert data from virtual format for register REGNUM
 364    to raw format for register REGNUM.  */
 365
 366 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
 367    bcopy ((FROM), (TO), REGISTER_RAW_SIZE (REGNUM))
 368
 369 /* Return the GDB type object for the "standard" data type
 370    of data in register N.  */
 371
 372 #define REGISTER_VIRTUAL_TYPE(N) \
 373  (((unsigned)(N) - FP0_REGNUM) < 32 ? builtin_type_double : builtin_type_int)
 374
 375 /* Store the address of the place in which to copy the structure the
 376    subroutine will return.  This is called from call_function. */
 377 /* in RS6000, struct return addresses are passed as an extra parameter in r3.
 378    In function return, callee is not responsible of returning this address back.
 379    Since gdb needs to find it, we will store in a designated variable
 380    `rs6000_struct_return_address'. */
 381
 382 extern unsigned int rs6000_struct_return_address;
 383
 384 #define STORE_STRUCT_RETURN(ADDR, SP)   \
 385   { write_register (3, (ADDR));         \
 386     rs6000_struct_return_address = (unsigned int)(ADDR); }
 387
 388 /* Extract from an array REGBUF containing the (raw) register state
 389    a function return value of type TYPE, and copy that, in virtual format,
 390    into VALBUF.  */
 391
 392 /* #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 393   bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE)) */
 394
 395 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 396   extract_return_value(TYPE,REGBUF,VALBUF)
 397
 398 /* Write into appropriate registers a function return value
 399    of type TYPE, given in virtual format.  */
 400
 401 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 402   {                                                                     \
 403     if (TYPE_CODE (TYPE) == TYPE_CODE_FLT)                              \
 404                                                                         \
 405      /* Floating point values are returned starting from FPR1 and up.   \
 406         Say a double_double_double type could be returned in            \
 407         FPR1/FPR2/FPR3 triple. */                                       \
 408                                                                         \
 409       write_register_bytes (REGISTER_BYTE (FP0_REGNUM+1), (VALBUF),     \
 410                                                 TYPE_LENGTH (TYPE));    \
 411     else                                                                \
 412       /* Everything else is returned in GPR3 and up. */                 \
 413       write_register_bytes (REGISTER_BYTE (GP0_REGNUM+3), (VALBUF),     \
 414                                                 TYPE_LENGTH (TYPE));    \
 415   }
 416
 417
 418 /* Extract from an array REGBUF containing the (raw) register state
 419    the address in which a function should return its structure value,
 420    as a CORE_ADDR (or an expression that can be used as one).  */
 421
 422 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF)    rs6000_struct_return_address
 423
 424
 425 /* Do implement the attach and detach commands.  */
 426
 427 #define ATTACH_DETACH
 428
 429 /* infptrace.c requires those. */
 430
 431 #define PTRACE_ATTACH 30
 432 #define PTRACE_DETACH 31
 433
 434 \f
 435 /* Describe the pointer in each stack frame to the previous stack frame
 436    (its caller).  */
 437
 438 /* FRAME_CHAIN takes a frame's nominal address
 439    and produces the frame's chain-pointer. */
 440
 441 /* In the case of the RS6000, the frame's nominal address
 442    is the address of a 4-byte word containing the calling frame's address.  */
 443
 444 #define FRAME_CHAIN(thisframe)  \
 445   (!inside_entry_file ((thisframe)->pc) ?       \
 446    read_memory_integer ((thisframe)->frame, 4) :\
 447    0)
 448
 449 /* Define other aspects of the stack frame.  */
 450
 451 /* A macro that tells us whether the function invocation represented
 452    by FI does not have a frame on the stack associated with it.  If it
 453    does not, FRAMELESS is set to 1, else 0.  */
 454
 455 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 456         FRAMELESS = frameless_function_invocation (FI)
 457
 458 /* Functions calling alloca() change the value of the stack pointer. We
 459    need to use initial stack pointer (which is saved in r31 by gcc) in
 460    such cases. If a compiler emits traceback table, then we should use the
 461    alloca register specified in traceback table. FIXME. */
 462 /* Also, it is a good idea to cache information about frame's saved registers
 463    in the frame structure to speed things up. See tm-m88k.h. FIXME. */
 464
 465 #define EXTRA_FRAME_INFO        \
 466         CORE_ADDR initial_sp;                   /* initial stack pointer. */ \
 467         struct frame_saved_regs *cache_fsr;     /* saved registers        */
 468
 469 /* Frameless function invocation in IBM RS/6000 is half-done. It perfectly
 470    sets up a new frame, e.g. a new frame (in fact stack) pointer, etc, but it
 471    doesn't save the %pc. In the following, even though it is considered a
 472    frameless invocation, we still need to walk one frame up. */
 473
 474 #define INIT_EXTRA_FRAME_INFO(fromleaf, fi)     \
 475         fi->initial_sp = 0;             \
 476         fi->cache_fsr = 0;
 477
 478 #define FRAME_SAVED_PC(FRAME)           \
 479         read_memory_integer (read_memory_integer ((FRAME)->frame, 4)+8, 4)
 480
 481 #define FRAME_ARGS_ADDRESS(FI)  \
 482   (((struct frame_info*)(FI))->initial_sp ?             \
 483         ((struct frame_info*)(FI))->initial_sp :        \
 484         frame_initial_stack_address (FI))
 485
 486 #define FRAME_LOCALS_ADDRESS(FI)        FRAME_ARGS_ADDRESS(FI)
 487
 488
 489 /* Set VAL to the number of args passed to frame described by FI.
 490    Can set VAL to -1, meaning no way to tell.  */
 491
 492 /* We can't tell how many args there are
 493    now that the C compiler delays popping them.  */
 494
 495 #define FRAME_NUM_ARGS(val,fi) (val = -1)
 496
 497 /* Return number of bytes at start of arglist that are not really args.  */
 498
 499 #define FRAME_ARGS_SKIP 8       /* Not sure on this. FIXMEmgo */
 500
 501 /* Put here the code to store, into a struct frame_saved_regs,
 502    the addresses of the saved registers of frame described by FRAME_INFO.
 503    This includes special registers such as pc and fp saved in special
 504    ways in the stack frame.  sp is even more special:
 505    the address we return for it IS the sp for the next frame.  */
 506 /* In the following implementation for RS6000, we did *not* save sp. I am
 507    not sure if it will be needed. The following macro takes care of gpr's
 508    and fpr's only. */
 509
 510 #define FRAME_FIND_SAVED_REGS(FRAME_INFO, FRAME_SAVED_REGS)             \
 511 {                                                                       \
 512   int ii, frame_addr, func_start;                                       \
 513   struct aix_framedata fdata;                                                   \
 514                                                                                 \
 515   /* find the start of the function and collect info about its frame. */        \
 516                                                                                 \
 517   func_start = get_pc_function_start ((FRAME_INFO)->pc) + FUNCTION_START_OFFSET;\
 518   function_frame_info (func_start, &fdata);                                     \
 519   bzero (&(FRAME_SAVED_REGS), sizeof (FRAME_SAVED_REGS));                       \
 520                                                                                 \
 521   /* if there were any saved registers, figure out parent's stack pointer. */   \
 522   frame_addr = 0;                                                               \
 523   /* the following is true only if the frame doesn't have a call to alloca(),   \
 524       FIXME. */                                                                 \
 525   if (fdata.saved_fpr >= 0 || fdata.saved_gpr >= 0) {                           \
 526     if ((FRAME_INFO)->prev && (FRAME_INFO)->prev->frame)                        \
 527       frame_addr = (FRAME_INFO)->prev->frame;                                   \
 528     else                                                                        \
 529       frame_addr = read_memory_integer ((FRAME_INFO)->frame, 4);                \
 530   }                                                                             \
 531                                                                                 \
 532   /* if != -1, fdata.saved_fpr is the smallest number of saved_fpr. All fpr's   \
 533      from saved_fpr to fp31 are saved right underneath caller stack pointer,    \
 534      starting from fp31 first. */                                               \
 535                                                                                 \
 536   if (fdata.saved_fpr >= 0) {                                                   \
 537     for (ii=31; ii >= fdata.saved_fpr; --ii)                                    \
 538       (FRAME_SAVED_REGS).regs [FP0_REGNUM + ii] = frame_addr - ((32 - ii) * 8); \
 539     frame_addr -= (32 - fdata.saved_fpr) * 8;                                   \
 540   }                                                                             \
 541                                                                                 \
 542   /* if != -1, fdata.saved_gpr is the smallest number of saved_gpr. All gpr's   \
 543      from saved_gpr to gpr31 are saved right under saved fprs, starting         \
 544      from r31 first. */                                                         \
 545                                                                                 \
 546   if (fdata.saved_gpr >= 0)                                                     \
 547     for (ii=31; ii >= fdata.saved_gpr; --ii)                                    \
 548       (FRAME_SAVED_REGS).regs [ii] = frame_addr - ((32 - ii) * 4);              \
 549 }
 550
 551 \f
 552 /* Things needed for making the inferior call functions.  */
 553
 554 /* Push an empty stack frame, to record the current PC, etc.  */
 555 /* Change these names into rs6k_{push, pop}_frame(). FIXMEmgo. */
 556
 557 #define PUSH_DUMMY_FRAME        push_dummy_frame ()
 558
 559 /* Discard from the stack the innermost frame,
 560    restoring all saved registers.  */
 561
 562 #define POP_FRAME       pop_frame ()
 563
 564 /* This sequence of words is the instructions:
 565
 566         mflr    r0              // 0x7c0802a6
 567                                 // save fpr's
 568         stfd    r?, num(r1)     // 0xd8010000 there should be 32 of this??
 569                                 // save gpr's
 570         stm     r0, num(r1)     // 0xbc010000
 571         stu     r1, num(r1)     // 0x94210000
 572
 573         // the function we want to branch might be in a different load
 574         // segment. reset the toc register. Note that the actual toc address
 575         // will be fix by fix_call_dummy () along with function address.
 576
 577         st      r2, 0x14(r1)    // 0x90410014 save toc register
 578         liu     r2, 0x1234      // 0x3c401234 reset a new toc value 0x12345678
 579         oril    r2, r2,0x5678   // 0x60425678
 580
 581                                 // load absolute address 0x12345678 to r0
 582         liu     r0, 0x1234      // 0x3c001234
 583         oril    r0, r0,0x5678   // 0x60005678
 584         mtctr   r0              // 0x7c0903a6 ctr <- r0
 585         bctrl                   // 0x4e800421 jump subroutine 0x12345678 (%ctr)
 586         cror    0xf, 0xf, 0xf   // 0x4def7b82
 587         brpt                    // 0x7d821008, breakpoint
 588         cror    0xf, 0xf, 0xf   // 0x4def7b82 (for 8 byte alignment)
 589
 590
 591   We actually start executing by saving the toc register first, since the pushing
 592   of the registers is done by PUSH_DUMMY_FRAME.  If this were real code,
 593   the arguments for the function called by the `bctrl' would be pushed
 594   between the `stu' and the `bctrl', and we could allow it to execute through.
 595   But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
 596   and we cannot allow to push the registers again.
 597 */
 598
 599 #define CALL_DUMMY {0x7c0802a6, 0xd8010000, 0xbc010000, 0x94210000, \
 600                     0x90410014, 0x3c401234, 0x60425678,             \
 601                     0x3c001234, 0x60005678, 0x7c0903a6, 0x4e800421, \
 602                     0x4def7b82, 0x7d821008, 0x4def7b82 }
 603
 604
 605 /* keep this as multiple of 8 (%sp requires 8 byte alignment) */
 606 #define CALL_DUMMY_LENGTH 56
 607
 608 #define CALL_DUMMY_START_OFFSET 16
 609
 610 /* Insert the specified number of args and function address
 611    into a call sequence of the above form stored at DUMMYNAME.  */
 612
 613 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, using_gcc) \
 614         fix_call_dummy(dummyname, pc, fun, nargs, type)
 615
 616
 617 /* Signal handler for SIGWINCH `window size changed'. */
 618
 619 #define SIGWINCH_HANDLER  aix_resizewindow
 620 extern  void    aix_resizewindow ();
 621
 622 /* `lines_per_page' and `chars_per_line' are local to utils.c. Rectify this. */
 623
 624 #define SIGWINCH_HANDLER_BODY   \
 625                                                                         \
 626 /* Respond to SIGWINCH `window size changed' signal, and reset GDB's    \
 627    window settings approproatelt. */                                    \
 628                                                                         \
 629 void                                            \
 630 aix_resizewindow ()                             \
 631 {                                               \
 632   int fd = fileno (stdout);                     \
 633   if (isatty (fd)) {                            \
 634     int val;                                    \
 635                                                 \
 636     val = atoi (termdef (fd, 'l'));             \
 637     if (val > 0)                                \
 638       lines_per_page = val;                     \
 639     val = atoi (termdef (fd, 'c'));             \
 640     if (val > 0)                                \
 641       chars_per_line = val;                     \
 642   }                                             \
 643 }
 644
 645
 646 /* Flag for machine-specific stuff in shared files.  FIXME */
 647 #define IBM6000_TARGET