boehm-gc/config.h

   1 /*
   2  * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
   3  * Copyright (c) 1991-1994 by Xerox Corporation.  All rights reserved.
   4  * Copyright (c) 1996 by Silicon Graphics.  All rights reserved.
   5  *
   6  * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
   7  * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
   8  *
   9  * Permission is hereby granted to use or copy this program
  10  * for any purpose,  provided the above notices are retained on all copies.
  11  * Permission to modify the code and to distribute modified code is granted,
  12  * provided the above notices are retained, and a notice that the code was
  13  * modified is included with the above copyright notice.
  14  */
  15
  16 #ifndef CONFIG_H
  17
  18 # define CONFIG_H
  19
  20 /* Machine dependent parameters.  Some tuning parameters can be found   */
  21 /* near the top of gc_private.h.                                        */
  22
  23 /* Machine specific parts contributed by various people.  See README file. */
  24
  25 /* Determine the machine type: */
  26 # if defined(sun) && defined(mc68000)
  27 #    define M68K
  28 #    define SUNOS4
  29 #    define mach_type_known
  30 # endif
  31 # if defined(hp9000s300)
  32 #    define M68K
  33 #    define HP
  34 #    define mach_type_known
  35 # endif
  36 # if defined(__NetBSD__) && defined(m68k)
  37 #    define M68K
  38 #    define NETBSD
  39 #    define mach_type_known
  40 # endif
  41 # if defined(vax)
  42 #    define VAX
  43 #    ifdef ultrix
  44 #       define ULTRIX
  45 #    else
  46 #       define BSD
  47 #    endif
  48 #    define mach_type_known
  49 # endif
  50 # if defined(mips) || defined(__mips)
  51 #    define MIPS
  52 #    if defined(ultrix) || defined(__ultrix) || defined(__NetBSD__)
  53 #       define ULTRIX
  54 #    else
  55 #       if defined(_SYSTYPE_SVR4) || defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4__)
  56 #         define IRIX5   /* or IRIX 6.X */
  57 #       else
  58 #         define RISCOS  /* or IRIX 4.X */
  59 #       endif
  60 #    endif
  61 #    define mach_type_known
  62 # endif
  63 # if defined(sequent) && defined(i386)
  64 #    define I386
  65 #    define SEQUENT
  66 #    define mach_type_known
  67 # endif
  68 # if defined(sun) && defined(i386)
  69 #    define I386
  70 #    define SUNOS5
  71 #    define mach_type_known
  72 # endif
  73 # if (defined(__OS2__) || defined(__EMX__)) && defined(__32BIT__)
  74 #    define I386
  75 #    define OS2
  76 #    define mach_type_known
  77 # endif
  78 # if defined(ibm032)
  79 #   define RT
  80 #   define mach_type_known
  81 # endif
  82 # if defined(sun) && (defined(sparc) || defined(__sparc))
  83 #   define SPARC
  84     /* Test for SunOS 5.x */
  85 #     include <errno.h>
  86 #     ifdef ECHRNG
  87 #       define SUNOS5
  88 #     else
  89 #       define SUNOS4
  90 #     endif
  91 #   define mach_type_known
  92 # endif
  93 # if defined(sparc) && defined(unix) && !defined(sun)
  94 #   define SPARC
  95 #   define DRSNX
  96 #   define mach_type_known
  97 # endif
  98 # if defined(_IBMR2)
  99 #   define RS6000
 100 #   define mach_type_known
 101 # endif
 102 # if defined(_M_XENIX) && defined(_M_SYSV) && defined(_M_I386)
 103         /* The above test may need refinement   */
 104 #   define I386
 105 #   if defined(_SCO_ELF)
 106 #     define SCO_ELF
 107 #   else
 108 #     define SCO
 109 #   endif
 110 #   define mach_type_known
 111 # endif
 112 # if defined(_AUX_SOURCE)
 113 #   define M68K
 114 #   define SYSV
 115 #   define mach_type_known
 116 # endif
 117 # if defined(_PA_RISC1_0) || defined(_PA_RISC1_1)
 118 #   define HP_PA
 119 #   define mach_type_known
 120 # endif
 121 # if defined(linux) && defined(i386)
 122 #    define I386
 123 #    define LINUX
 124 #    define mach_type_known
 125 # endif
 126 # if defined(linux) && defined(powerpc)
 127 #    define POWERPC
 128 #    define LINUX
 129 #    define mach_type_known
 130 # endif
 131 # if defined(__alpha) || defined(__alpha__)
 132 #   define ALPHA
 133 #   if defined(linux) || defined(__linux__)
 134 #     define LINUX
 135 #   else
 136 #     define OSF1       /* a.k.a Digital Unix */
 137 #   endif
 138 #   define mach_type_known
 139 # endif
 140 # if defined(_AMIGA)
 141 #   define M68K
 142 #   define AMIGA
 143 #   define mach_type_known
 144 # endif
 145 # if defined(THINK_C) || defined(__MWERKS__) && !defined(__powerc)
 146 #   define M68K
 147 #   define MACOS
 148 #   define mach_type_known
 149 # endif
 150 # if defined(__MWERKS__) && defined(__powerc)
 151 #   define POWERPC
 152 #   define MACOS
 153 #   define mach_type_known
 154 # endif
 155 # if defined(NeXT) && defined(mc68000)
 156 #   define M68K
 157 #   define NEXT
 158 #   define mach_type_known
 159 # endif
 160 # if defined(NeXT) && defined(i386)
 161 #   define I386
 162 #   define NEXT
 163 #   define mach_type_known
 164 # endif
 165 # if defined(__FreeBSD__) && defined(i386)
 166 #   define I386
 167 #   define FREEBSD
 168 #   define mach_type_known
 169 # endif
 170 # if defined(__NetBSD__) && defined(i386)
 171 #   define I386
 172 #   define NETBSD
 173 #   define mach_type_known
 174 # endif
 175 # if defined(bsdi) && defined(i386)
 176 #    define I386
 177 #    define BSDI
 178 #    define mach_type_known
 179 # endif
 180 # if !defined(mach_type_known) && defined(__386BSD__)
 181 #   define I386
 182 #   define THREE86BSD
 183 #   define mach_type_known
 184 # endif
 185 # if defined(_CX_UX) && defined(_M88K)
 186 #   define M88K
 187 #   define CX_UX
 188 #   define mach_type_known
 189 # endif
 190 # if defined(DGUX)
 191 #   define M88K
 192     /* DGUX defined */
 193 #   define mach_type_known
 194 # endif
 195 # if (defined(_MSDOS) || defined(_MSC_VER)) && (_M_IX86 >= 300)
 196 #   define I386
 197 #   define MSWIN32      /* or Win32s */
 198 #   define mach_type_known
 199 # endif
 200 # if defined(__DJGPP__)
 201 #   define I386
 202 #   ifndef DJGPP
 203 #     define DJGPP  /* MSDOS running the DJGPP port of GCC */
 204 #   endif
 205 #   define mach_type_known
 206 # endif
 207 # if defined(__CYGWIN32__)
 208 #   define I386
 209 #   define CYGWIN32
 210 #   define mach_type_known
 211 # endif
 212 # if defined(__BORLANDC__)
 213 #   define I386
 214 #   define MSWIN32
 215 #   define mach_type_known
 216 # endif
 217 # if defined(_UTS) && !defined(mach_type_known)
 218 #   define S370
 219 #   define UTS4
 220 #   define mach_type_known
 221 # endif
 222 /* Ivan Demakov */
 223 # if defined(__WATCOMC__) && defined(__386__)
 224 #   define I386
 225 #   if !defined(OS2) && !defined(MSWIN32) && !defined(DOS4GW)
 226 #     if defined(__OS2__)
 227 #       define OS2
 228 #     else
 229 #       if defined(__WINDOWS_386__) || defined(__NT__)
 230 #         define MSWIN32
 231 #       else
 232 #         define DOS4GW
 233 #       endif
 234 #     endif
 235 #   endif
 236 #   define mach_type_known
 237 # endif
 238
 239 /* Feel free to add more clauses here */
 240
 241 /* Or manually define the machine type here.  A machine type is         */
 242 /* characterized by the architecture.  Some                             */
 243 /* machine types are further subdivided by OS.                          */
 244 /* the macros ULTRIX, RISCOS, and BSD to distinguish.                   */
 245 /* Note that SGI IRIX is treated identically to RISCOS.                 */
 246 /* SYSV on an M68K actually means A/UX.                                 */
 247 /* The distinction in these cases is usually the stack starting address */
 248 # ifndef mach_type_known
 249         --> unknown machine type
 250 # endif
 251                     /* Mapping is: M68K       ==> Motorola 680X0        */
 252                     /*             (SUNOS4,HP,NEXT, and SYSV (A/UX),    */
 253                     /*             MACOS and AMIGA variants)            */
 254                     /*             I386       ==> Intel 386             */
 255                     /*              (SEQUENT, OS2, SCO, LINUX, NETBSD,  */
 256                     /*               FREEBSD, THREE86BSD, MSWIN32,      */
 257                     /*               BSDI, SUNOS5, NEXT variants)       */
 258                     /*             NS32K      ==> Encore Multimax       */
 259                     /*             MIPS       ==> R2000 or R3000        */
 260                     /*                  (RISCOS, ULTRIX variants)       */
 261                     /*             VAX        ==> DEC VAX               */
 262                     /*                  (BSD, ULTRIX variants)          */
 263                     /*             RS6000     ==> IBM RS/6000 AIX3.X    */
 264                     /*             RT         ==> IBM PC/RT             */
 265                     /*             HP_PA      ==> HP9000/700 & /800     */
 266                     /*                            HP/UX                 */
 267                     /*             SPARC      ==> SPARC under SunOS     */
 268                     /*                  (SUNOS4, SUNOS5,                */
 269                     /*                   DRSNX variants)                */
 270                     /*             ALPHA      ==> DEC Alpha             */
 271                     /*                  (OSF1 and LINUX variants)       */
 272                     /*             M88K       ==> Motorola 88XX0        */
 273                     /*                  (CX_UX and DGUX)                */
 274                     /*             S370       ==> 370-like machine      */
 275                     /*                  running Amdahl UTS4             */
 276
 277
 278 /*
 279  * For each architecture and OS, the following need to be defined:
 280  *
 281  * CPP_WORD_SZ is a simple integer constant representing the word size.
 282  * in bits.  We assume byte addressibility, where a byte has 8 bits.
 283  * We also assume CPP_WORD_SZ is either 32 or 64.
 284  * (We care about the length of pointers, not hardware
 285  * bus widths.  Thus a 64 bit processor with a C compiler that uses
 286  * 32 bit pointers should use CPP_WORD_SZ of 32, not 64. Default is 32.)
 287  *
 288  * MACH_TYPE is a string representation of the machine type.
 289  * OS_TYPE is analogous for the OS.
 290  *
 291  * ALIGNMENT is the largest N, such that
 292  * all pointer are guaranteed to be aligned on N byte boundaries.
 293  * defining it to be 1 will always work, but perform poorly.
 294  *
 295  * DATASTART is the beginning of the data segment.
 296  * On UNIX systems, the collector will scan the area between DATASTART
 297  * and DATAEND for root pointers.
 298  *
 299  * DATAEND, if not &end.
 300  *
 301  * ALIGN_DOUBLE of GC_malloc should return blocks aligned to twice
 302  * the pointer size.
 303  *
 304  * STACKBOTTOM is the cool end of the stack, which is usually the
 305  * highest address in the stack.
 306  * Under PCR or OS/2, we have other ways of finding thread stacks.
 307  * For each machine, the following should:
 308  * 1) define STACK_GROWS_UP if the stack grows toward higher addresses, and
 309  * 2) define exactly one of
 310  *      STACKBOTTOM (should be defined to be an expression)
 311  *      HEURISTIC1
 312  *      HEURISTIC2
 313  * If either of the last two macros are defined, then STACKBOTTOM is computed
 314  * during collector startup using one of the following two heuristics:
 315  * HEURISTIC1:  Take an address inside GC_init's frame, and round it up to
 316  *              the next multiple of STACK_GRAN.
 317  * HEURISTIC2:  Take an address inside GC_init's frame, increment it repeatedly
 318  *              in small steps (decrement if STACK_GROWS_UP), and read the value
 319  *              at each location.  Remember the value when the first
 320  *              Segmentation violation or Bus error is signalled.  Round that
 321  *              to the nearest plausible page boundary, and use that instead
 322  *              of STACKBOTTOM.
 323  *
 324  * If no expression for STACKBOTTOM can be found, and neither of the above
 325  * heuristics are usable, the collector can still be used with all of the above
 326  * undefined, provided one of the following is done:
 327  * 1) GC_mark_roots can be changed to somehow mark from the correct stack(s)
 328  *    without reference to STACKBOTTOM.  This is appropriate for use in
 329  *    conjunction with thread packages, since there will be multiple stacks.
 330  *    (Allocating thread stacks in the heap, and treating them as ordinary
 331  *    heap data objects is also possible as a last resort.  However, this is
 332  *    likely to introduce significant amounts of excess storage retention
 333  *    unless the dead parts of the thread stacks are periodically cleared.)
 334  * 2) Client code may set GC_stackbottom before calling any GC_ routines.
 335  *    If the author of the client code controls the main program, this is
 336  *    easily accomplished by introducing a new main program, setting
 337  *    GC_stackbottom to the address of a local variable, and then calling
 338  *    the original main program.  The new main program would read something
 339  *    like:
 340  *
 341  *              # include "gc_private.h"
 342  *
 343  *              main(argc, argv, envp)
 344  *              int argc;
 345  *              char **argv, **envp;
 346  *              {
 347  *                  int dummy;
 348  *
 349  *                  GC_stackbottom = (ptr_t)(&dummy);
 350  *                  return(real_main(argc, argv, envp));
 351  *              }
 352  *
 353  *
 354  * Each architecture may also define the style of virtual dirty bit
 355  * implementation to be used:
 356  *   MPROTECT_VDB: Write protect the heap and catch faults.
 357  *   PROC_VDB: Use the SVR4 /proc primitives to read dirty bits.
 358  *
 359  * An architecture may define DYNAMIC_LOADING if dynamic_load.c
 360  * defined GC_register_dynamic_libraries() for the architecture.
 361  */
 362
 363
 364 # define STACK_GRAN 0x1000000
 365 # ifdef M68K
 366 #   define MACH_TYPE "M68K"
 367 #   define ALIGNMENT 2
 368 #   ifdef NETBSD
 369 #       define OS_TYPE "NETBSD"
 370 #       define HEURISTIC2
 371         extern char etext;
 372 #       define DATASTART ((ptr_t)(&etext))
 373 #   endif
 374 #   ifdef SUNOS4
 375 #       define OS_TYPE "SUNOS4"
 376         extern char etext;
 377 #       define DATASTART ((ptr_t)((((word) (&etext)) + 0x1ffff) & ~0x1ffff))
 378 #       define HEURISTIC1       /* differs      */
 379 #       define DYNAMIC_LOADING
 380 #   endif
 381 #   ifdef HP
 382 #       define OS_TYPE "HP"
 383         extern char etext;
 384 #       define DATASTART ((ptr_t)((((word) (&etext)) + 0xfff) & ~0xfff))
 385 #       define STACKBOTTOM ((ptr_t) 0xffeffffc)
 386                               /* empirically determined.  seems to work. */
 387 #       include <unistd.h>
 388 #       define GETPAGESIZE() sysconf(_SC_PAGE_SIZE)
 389 #   endif
 390 #   ifdef SYSV
 391 #       define OS_TYPE "SYSV"
 392         extern etext;
 393 #       define DATASTART ((ptr_t)((((word) (&etext)) + 0x3fffff) \
 394                                    & ~0x3fffff) \
 395                                   +((word)&etext & 0x1fff))
 396         /* This only works for shared-text binaries with magic number 0413.
 397            The other sorts of SysV binaries put the data at the end of the text,
 398            in which case the default of &etext would work.  Unfortunately,
 399            handling both would require having the magic-number available.
 400                                 -- Parag
 401            */
 402 #       define STACKBOTTOM ((ptr_t)0xFFFFFFFE)
 403                         /* The stack starts at the top of memory, but   */
 404                         /* 0x0 cannot be used as setjump_test complains */
 405                         /* that the stack direction is incorrect.  Two  */
 406                         /* bytes down from 0x0 should be safe enough.   */
 407                         /*              --Parag                         */
 408 #       include <sys/mmu.h>
 409 #       define GETPAGESIZE() PAGESIZE   /* Is this still right? */
 410 #   endif
 411 #   ifdef AMIGA
 412 #       define OS_TYPE "AMIGA"
 413                 /* STACKBOTTOM and DATASTART handled specially  */
 414                 /* in os_dep.c                                  */
 415 #       define DATAEND  /* not needed */
 416 #       define GETPAGESIZE() 4096
 417 #   endif
 418 #   ifdef MACOS
 419 #     ifndef __LOWMEM__
 420 #     include <LowMem.h>
 421 #     endif
 422 #     define OS_TYPE "MACOS"
 423                         /* see os_dep.c for details of global data segments. */
 424 #     define STACKBOTTOM ((ptr_t) LMGetCurStackBase())
 425 #     define DATAEND    /* not needed */
 426 #     define GETPAGESIZE() 4096
 427 #   endif
 428 #   ifdef NEXT
 429 #       define OS_TYPE "NEXT"
 430 #       define DATASTART ((ptr_t) get_etext())
 431 #       define STACKBOTTOM ((ptr_t) 0x4000000)
 432 #       define DATAEND  /* not needed */
 433 #   endif
 434 # endif
 435
 436 # ifdef POWERPC
 437 #   define MACH_TYPE "POWERPC"
 438 #   define ALIGNMENT 2
 439 #   ifdef MACOS
 440 #     ifndef __LOWMEM__
 441 #     include <LowMem.h>
 442 #     endif
 443 #     define OS_TYPE "MACOS"
 444                         /* see os_dep.c for details of global data segments. */
 445 #     define STACKBOTTOM ((ptr_t) LMGetCurStackBase())
 446 #     define DATAEND  /* not needed */
 447 #   endif
 448 #   ifdef LINUX
 449 #     define OS_TYPE "LINUX"
 450 #     define STACKBOTTOM ((ptr_t)0x80000000)
 451 #     define DATASTART GC_data_start
 452       extern int _end;
 453 #     define DATAEND (&_end)
 454 #   endif
 455 # endif
 456
 457 # ifdef VAX
 458 #   define MACH_TYPE "VAX"
 459 #   define ALIGNMENT 4  /* Pointers are longword aligned by 4.2 C compiler */
 460     extern char etext;
 461 #   define DATASTART ((ptr_t)(&etext))
 462 #   ifdef BSD
 463 #       define OS_TYPE "BSD"
 464 #       define HEURISTIC1
 465                         /* HEURISTIC2 may be OK, but it's hard to test. */
 466 #   endif
 467 #   ifdef ULTRIX
 468 #       define OS_TYPE "ULTRIX"
 469 #       define STACKBOTTOM ((ptr_t) 0x7fffc800)
 470 #   endif
 471 # endif
 472
 473 # ifdef RT
 474 #   define MACH_TYPE "RT"
 475 #   define ALIGNMENT 4
 476 #   define DATASTART ((ptr_t) 0x10000000)
 477 #   define STACKBOTTOM ((ptr_t) 0x1fffd800)
 478 # endif
 479
 480 # ifdef SPARC
 481 #   define MACH_TYPE "SPARC"
 482 #   define ALIGNMENT 4  /* Required by hardware */
 483 #   define ALIGN_DOUBLE
 484     extern int etext;
 485 #   ifdef SUNOS5
 486 #       define OS_TYPE "SUNOS5"
 487         extern int _etext;
 488         extern int _end;
 489         extern char * GC_SysVGetDataStart();
 490 #       define DATASTART (ptr_t)GC_SysVGetDataStart(0x10000, &_etext)
 491 #       define DATAEND (&_end)
 492 #       ifndef USE_MMAP
 493 #           define USE_MMAP
 494 #       endif
 495 #       ifdef USE_MMAP
 496 #         define HEAP_START (ptr_t)0x40000000
 497 #       else
 498 #         define HEAP_START DATAEND
 499 #       endif
 500 #       define PROC_VDB
 501 #       define HEURISTIC1
 502 #       include <unistd.h>
 503 #       define GETPAGESIZE()  sysconf(_SC_PAGESIZE)
 504                 /* getpagesize() appeared to be missing from at least one */
 505                 /* Solaris 5.4 installation.  Weird.                      */
 506 #   endif
 507 #   ifdef SUNOS4
 508 #       define OS_TYPE "SUNOS4"
 509         /* [If you have a weak stomach, don't read this.]               */
 510         /* We would like to use:                                        */
 511 /* #       define DATASTART ((ptr_t)((((word) (&etext)) + 0x1fff) & ~0x1fff)) */
 512         /* This fails occasionally, due to an ancient, but very         */
 513         /* persistent ld bug.  &etext is set 32 bytes too high.         */
 514         /* We instead read the text segment size from the a.out         */
 515         /* header, which happens to be mapped into our address space    */
 516         /* at the start of the text segment.  The detective work here   */
 517         /* was done by Robert Ehrlich, Manuel Serrano, and Bernard      */
 518         /* Serpette of INRIA.                                           */
 519         /* This assumes ZMAGIC, i.e. demand-loadable executables.       */
 520 #       define TEXTSTART 0x2000
 521 #       define DATASTART ((ptr_t)(*(int *)(TEXTSTART+0x4)+TEXTSTART))
 522 #       define MPROTECT_VDB
 523 #       define HEURISTIC1
 524 #   endif
 525 #   ifdef DRSNX
 526 #       define CPP_WORDSZ 32
 527 #       define OS_TYPE "DRSNX"
 528         extern char * GC_SysVGetDataStart();
 529         extern int etext;
 530 #       define DATASTART (ptr_t)GC_SysVGetDataStart(0x10000, &etext)
 531 #       define MPROTECT_VDB
 532 #       define STACKBOTTOM ((ptr_t) 0xdfff0000)
 533 #   endif
 534 #   define DYNAMIC_LOADING
 535 # endif
 536
 537 # ifdef I386
 538 #   define MACH_TYPE "I386"
 539 #   define ALIGNMENT 4  /* Appears to hold for all "32 bit" compilers   */
 540                         /* except Borland.  The -a4 option fixes        */
 541                         /* Borland.                                     */
 542                         /* Ivan Demakov: For Watcom the option is -zp4. */
 543 #   ifndef SMALL_CONFIG
 544 #     define ALIGN_DOUBLE /* Not strictly necessary, but may give speed   */
 545                           /* improvement on Pentiums.                     */
 546 #   endif
 547 #   ifdef SEQUENT
 548 #       define OS_TYPE "SEQUENT"
 549         extern int etext;
 550 #       define DATASTART ((ptr_t)((((word) (&etext)) + 0xfff) & ~0xfff))
 551 #       define STACKBOTTOM ((ptr_t) 0x3ffff000)
 552 #   endif
 553 #   ifdef SUNOS5
 554 #       define OS_TYPE "SUNOS5"
 555         extern int etext, _start;
 556         extern char * GC_SysVGetDataStart();
 557 #       define DATASTART GC_SysVGetDataStart(0x1000, &etext)
 558 #       define STACKBOTTOM ((ptr_t)(&_start))
 559 /** At least in Solaris 2.5, PROC_VDB gives wrong values for dirty bits. */
 560 /*#     define PROC_VDB*/
 561 #       define DYNAMIC_LOADING
 562 #       ifndef USE_MMAP
 563 #           define USE_MMAP
 564 #       endif
 565 #       ifdef USE_MMAP
 566 #         define HEAP_START (ptr_t)0x40000000
 567 #       else
 568 #         define HEAP_START DATAEND
 569 #       endif
 570 #   endif
 571 #   ifdef SCO
 572 #       define OS_TYPE "SCO"
 573         extern int etext;
 574 #       define DATASTART ((ptr_t)((((word) (&etext)) + 0x3fffff) \
 575                                   & ~0x3fffff) \
 576                                  +((word)&etext & 0xfff))
 577 #       define STACKBOTTOM ((ptr_t) 0x7ffffffc)
 578 #   endif
 579 #   ifdef SCO_ELF
 580 #       define OS_TYPE "SCO_ELF"
 581         extern int etext;
 582 #       define DATASTART ((ptr_t)(&etext))
 583 #       define STACKBOTTOM ((ptr_t) 0x08048000)
 584 #       define DYNAMIC_LOADING
 585 #       define ELF_CLASS ELFCLASS32
 586 #   endif
 587 #   ifdef LINUX
 588 #       define OS_TYPE "LINUX"
 589 #       define STACKBOTTOM ((ptr_t)0xc0000000)
 590         /* Appears to be 0xe0000000 for at least one 2.1.91 kernel.     */
 591         /* Probably needs to be more flexible, but I don't yet          */
 592         /* fully understand how flexible.                               */
 593 #       define MPROTECT_VDB
 594 #       ifdef __ELF__
 595 #            define DYNAMIC_LOADING
 596 #            ifdef UNDEFINED    /* includes ro data */
 597                extern int _etext;
 598 #              define DATASTART ((ptr_t)((((word) (&_etext)) + 0xfff) & ~0xfff))
 599 #            endif
 600 #            include <linux/version.h>
 601 #            include <features.h>
 602 #            if LINUX_VERSION_CODE >= 0x20000 && defined(__GLIBC__) && __GLIBC__ >= 2
 603                  extern int __data_start;
 604 #                define DATASTART ((ptr_t)(&__data_start))
 605 #            else
 606                  extern char **__environ;
 607 #                define DATASTART ((ptr_t)(&__environ))
 608                               /* hideous kludge: __environ is the first */
 609                               /* word in crt0.o, and delimits the start */
 610                               /* of the data segment, no matter which   */
 611                               /* ld options were passed through.        */
 612                               /* We could use _etext instead, but that  */
 613                               /* would include .rodata, which may       */
 614                               /* contain large read-only data tables    */
 615                               /* that we'd rather not scan.             */
 616 #            endif
 617              extern int _end;
 618 #            define DATAEND (&_end)
 619 #       else
 620              extern int etext;
 621 #            define DATASTART ((ptr_t)((((word) (&etext)) + 0xfff) & ~0xfff))
 622 #       endif
 623 #   endif
 624 #   ifdef CYGWIN32
 625           extern int _data_start__;
 626           extern int _data_end__;
 627           extern int _bss_start__;
 628           extern int _bss_end__;
 629         /* For binutils 2.9.1, we have                  */
 630         /*      DATASTART   = _data_start__             */
 631         /*      DATAEND     = _bss_end__                */
 632         /* whereas for some earlier versions it was     */
 633         /*      DATASTART   = _bss_start__              */
 634         /*      DATAEND     = _data_end__               */
 635         /* To get it right for both, we take the        */
 636         /* minumum/maximum of the two.                  */
 637 #       define MAX(x,y) ((x) > (y) ? (x) : (y))
 638 #       define MIN(x,y) ((x) < (y) ? (x) : (y))
 639 #       define DATASTART ((ptr_t) MIN(_data_start__, _bss_start__))
 640 #       define DATAEND   ((ptr_t) MAX(_data_end__, _bss_end__))
 641 #       undef STACK_GRAN
 642 #       define STACK_GRAN 0x10000
 643 #       define HEURISTIC1
 644 #   endif
 645 #   ifdef OS2
 646 #       define OS_TYPE "OS2"
 647                 /* STACKBOTTOM and DATASTART are handled specially in   */
 648                 /* os_dep.c. OS2 actually has the right                 */
 649                 /* system call!                                         */
 650 #       define DATAEND  /* not needed */
 651 #   endif
 652 #   ifdef MSWIN32
 653 #       define OS_TYPE "MSWIN32"
 654                 /* STACKBOTTOM and DATASTART are handled specially in   */
 655                 /* os_dep.c.                                            */
 656 #       ifndef __WATCOMC__
 657 #         define MPROTECT_VDB
 658 #       endif
 659 #       define DATAEND  /* not needed */
 660 #   endif
 661 #   ifdef DJGPP
 662 #       define OS_TYPE "DJGPP"
 663 #       include "stubinfo.h"
 664         extern int etext;
 665         extern int _stklen;
 666 #       define DATASTART ((ptr_t)((((word) (&etext)) + 0x1ff) & ~0x1ff))
 667 #       define STACKBOTTOM ((ptr_t)((word) _stubinfo + _stubinfo->size \
 668                                                      + _stklen))
 669                 /* This may not be right.  */
 670 #   endif
 671 #   ifdef FREEBSD
 672 #       define OS_TYPE "FREEBSD"
 673 #       define MPROTECT_VDB
 674 #   endif
 675 #   ifdef NETBSD
 676 #       define OS_TYPE "NETBSD"
 677 #   endif
 678 #   ifdef THREE86BSD
 679 #       define OS_TYPE "THREE86BSD"
 680 #   endif
 681 #   ifdef BSDI
 682 #       define OS_TYPE "BSDI"
 683 #   endif
 684 #   if defined(FREEBSD) || defined(NETBSD) \
 685         || defined(THREE86BSD) || defined(BSDI)
 686 #       define HEURISTIC2
 687         extern char etext;
 688 #       define DATASTART ((ptr_t)(&etext))
 689 #   endif
 690 #   ifdef NEXT
 691 #       define OS_TYPE "NEXT"
 692 #       define DATASTART ((ptr_t) get_etext())
 693 #       define STACKBOTTOM ((ptr_t)0xc0000000)
 694 #       define DATAEND  /* not needed */
 695 #   endif
 696 #   ifdef DOS4GW
 697 #     define OS_TYPE "DOS4GW"
 698       /* Get_DATASTART, Get_DATAEND, Get_STACKBOTTOM
 699        *      Defined in gc-watcom.asm
 700        */
 701       extern char* Get_DATASTART (void);
 702       extern char* Get_DATAEND (void);
 703       extern char* Get_STACKBOTTOM (void);
 704 #     pragma aux Get_DATASTART "*" value [eax];
 705 #     pragma aux Get_DATAEND "*" value [eax];
 706 #     pragma aux Get_STACKBOTTOM "*" value [eax];
 707 #     define DATASTART ((ptr_t) Get_DATASTART())
 708 #     define STACKBOTTOM ((ptr_t) Get_STACKBOTTOM())
 709 #     define DATAEND ((ptr_t) Get_DATAEND())
 710 #   endif
 711 # endif
 712
 713 # ifdef NS32K
 714 #   define MACH_TYPE "NS32K"
 715 #   define ALIGNMENT 4
 716     extern char **environ;
 717 #   define DATASTART ((ptr_t)(&environ))
 718                               /* hideous kludge: environ is the first   */
 719                               /* word in crt0.o, and delimits the start */
 720                               /* of the data segment, no matter which   */
 721                               /* ld options were passed through.        */
 722 #   define STACKBOTTOM ((ptr_t) 0xfffff000) /* for Encore */
 723 # endif
 724
 725 # ifdef MIPS
 726 # ifndef ECOS
 727 #   define MACH_TYPE "MIPS"
 728         /* CYGNUS LOCAL: respect predefined DATASTART_IS_ETEXT.  */
 729 #   ifdef DATASTART_IS_ETEXT
 730         extern int _etext;
 731 #     define DATASTART ((ptr_t)(&_etext))
 732 #   else
 733 #     ifndef IRIX5
 734 #       define DATASTART (ptr_t)0x10000000
 735                               /* Could probably be slightly higher since */
 736                               /* startup code allocates lots of stuff.   */
 737 #     else
 738         extern int _fdata;
 739 #       define DATASTART ((ptr_t)(&_fdata))
 740 #       ifdef USE_MMAP
 741 #           define HEAP_START (ptr_t)0x30000000
 742 #       else
 743 #           define HEAP_START DATASTART
 744 #       endif
 745                               /* Lowest plausible heap address.         */
 746                               /* In the MMAP case, we map there.        */
 747                               /* In either case it is used to identify  */
 748                               /* heap sections so they're not           */
 749                               /* considered as roots.                   */
 750 #     endif /* IRIX5 */
 751 #   endif /* DATASTART_IS_ETEXT */
 752 #   define HEURISTIC2
 753 /* #   define STACKBOTTOM ((ptr_t)0x7fff8000)  sometimes also works.  */
 754 #   ifdef ULTRIX
 755 #       define OS_TYPE "ULTRIX"
 756 #       define ALIGNMENT 4
 757 #   endif
 758 #   ifdef RISCOS
 759 #       define OS_TYPE "RISCOS"
 760 #       define ALIGNMENT 4  /* Required by hardware */
 761 #   endif
 762 #   ifdef IRIX5
 763 #       define OS_TYPE "IRIX5"
 764 #       define MPROTECT_VDB
 765 #       ifdef _MIPS_SZPTR
 766 #         define CPP_WORDSZ _MIPS_SZPTR
 767 #         define ALIGNMENT (_MIPS_SZPTR/8)
 768 #         if CPP_WORDSZ != 64
 769 #           define ALIGN_DOUBLE
 770 #         endif
 771 #       else
 772 #         define ALIGNMENT 4
 773 #         define ALIGN_DOUBLE
 774 #       endif
 775 #       define DYNAMIC_LOADING
 776 #   endif
 777 #   endif /* ECOS */
 778 # ifdef ECOS
 779     extern char __ram_data_start;
 780     extern char __ram_data_end;
 781 #   define MACH_TYPE "MIPS"
 782 #   define DATASTART (ptr_t)(&__ram_data_start)
 783 #   define DATAEND (ptr_t)(&__ram_data_end)
 784
 785 #   define HEURISTIC2
 786 #   define ALIGNMENT 4
 787 #   define ALIGN_DOUBLE
 788 #   endif /* ECOS */
 789 # endif
 790
 791 # ifdef RS6000
 792 #   define MACH_TYPE "RS6000"
 793 #   define ALIGNMENT 4
 794 #   define DATASTART ((ptr_t)0x20000000)
 795     extern int errno;
 796 #   define STACKBOTTOM ((ptr_t)((ulong)&errno))
 797 #   define DYNAMIC_LOADING
 798         /* For really old versions of AIX, this may have to be removed. */
 799 # endif
 800
 801 # ifdef HP_PA
 802 #   define MACH_TYPE "HP_PA"
 803 #   define ALIGNMENT 4
 804 #   define ALIGN_DOUBLE
 805     extern int __data_start;
 806 #   define DATASTART ((ptr_t)(&__data_start))
 807 #   if 0
 808         /* The following appears to work for 7xx systems running HP/UX  */
 809         /* 9.xx Furthermore, it might result in much faster             */
 810         /* collections than HEURISTIC2, which may involve scanning      */
 811         /* segments that directly precede the stack.  It is not the     */
 812         /* default, since it may not work on older machine/OS           */
 813         /* combinations. (Thanks to Raymond X.T. Nijssen for uncovering */
 814         /* this.)                                                       */
 815 #       define STACKBOTTOM ((ptr_t) 0x7b033000)  /* from /etc/conf/h/param.h */
 816 #   else
 817 #       define HEURISTIC2
 818 #   endif
 819 #   define STACK_GROWS_UP
 820 #   define DYNAMIC_LOADING
 821 #   include <unistd.h>
 822 #   define GETPAGESIZE() sysconf(_SC_PAGE_SIZE)
 823         /* They misspelled the Posix macro?     */
 824 # endif
 825
 826 # ifdef ALPHA
 827 #   define MACH_TYPE "ALPHA"
 828 #   define ALIGNMENT 8
 829 #   ifdef OSF1
 830 #       define OS_TYPE "OSF1"
 831 #       define DATASTART ((ptr_t) 0x140000000)
 832 #       define HEURISTIC2
 833         /* Normally HEURISTIC2 is too conervative, since                */
 834         /* the text segment immediately follows the stack.              */
 835         /* Hence we give an upper pound.                                */
 836         extern int __start;
 837 #       define HEURISTIC2_LIMIT ((ptr_t)((word)(&__start) & ~(getpagesize()-1)))
 838 #       define CPP_WORDSZ 64
 839 #       define MPROTECT_VDB
 840 #       define DYNAMIC_LOADING
 841 #   endif
 842 #   ifdef LINUX
 843 #       define OS_TYPE "LINUX"
 844 #       define CPP_WORDSZ 64
 845 #       define STACKBOTTOM ((ptr_t) 0x120000000)
 846 #       ifdef __ELF__
 847             extern int __data_start;
 848 #           define DATASTART &__data_start
 849 #           define DYNAMIC_LOADING
 850 #       else
 851 #           define DATASTART ((ptr_t) 0x140000000)
 852 #       endif
 853         extern int _end;
 854 #       define DATAEND (&_end)
 855         /* As of 1.3.90, I couldn't find a way to retrieve the correct  */
 856         /* fault address from a signal handler.                         */
 857         /* Hence MPROTECT_VDB is broken.                                */
 858 #   endif
 859 # endif
 860
 861 # ifdef M88K
 862 #   define MACH_TYPE "M88K"
 863 #   define ALIGNMENT 4
 864 #   define ALIGN_DOUBLE
 865     extern int etext;
 866 #   ifdef CX_UX
 867 #       define OS_TYPE "CX_UX"
 868 #       define DATASTART ((((word)&etext + 0x3fffff) & ~0x3fffff) + 0x10000)
 869 #   endif
 870 #   ifdef  DGUX
 871 #       define OS_TYPE "DGUX"
 872         extern char * GC_SysVGetDataStart();
 873 #       define DATASTART (ptr_t)GC_SysVGetDataStart(0x10000, &etext)
 874 #   endif
 875 #   define STACKBOTTOM ((char*)0xf0000000) /* determined empirically */
 876 # endif
 877
 878 # ifdef S370
 879 #   define MACH_TYPE "S370"
 880 #   define OS_TYPE "UTS4"
 881 #   define ALIGNMENT 4  /* Required by hardware */
 882     extern int etext;
 883         extern int _etext;
 884         extern int _end;
 885         extern char * GC_SysVGetDataStart();
 886 #       define DATASTART (ptr_t)GC_SysVGetDataStart(0x10000, &_etext)
 887 #       define DATAEND (&_end)
 888 #       define HEURISTIC2
 889 # endif
 890
 891 # ifndef STACK_GROWS_UP
 892 #   define STACK_GROWS_DOWN
 893 # endif
 894
 895 # ifndef CPP_WORDSZ
 896 #   define CPP_WORDSZ 32
 897 # endif
 898
 899 # ifndef OS_TYPE
 900 #   define OS_TYPE ""
 901 # endif
 902
 903 # ifndef DATAEND
 904     extern int end;
 905 #   define DATAEND (&end)
 906 # endif
 907
 908 # if defined(SVR4) && !defined(GETPAGESIZE)
 909 #    include <unistd.h>
 910 #    define GETPAGESIZE()  sysconf(_SC_PAGESIZE)
 911 # endif
 912
 913 # ifndef GETPAGESIZE
 914 #   if defined(SUNOS5) || defined(IRIX5)
 915 #       include <unistd.h>
 916 #   endif
 917 #   define GETPAGESIZE() getpagesize()
 918 # endif
 919
 920 # if defined(SUNOS5) || defined(DRSNX) || defined(UTS4)
 921     /* OS has SVR4 generic features.  Probably others also qualify.     */
 922 #   define SVR4
 923 # endif
 924
 925 # if defined(SUNOS5) || defined(DRSNX)
 926     /* OS has SUNOS5 style semi-undocumented interface to dynamic       */
 927     /* loader.                                                          */
 928 #   define SUNOS5DL
 929     /* OS has SUNOS5 style signal handlers.                             */
 930 #   define SUNOS5SIGS
 931 # endif
 932
 933 # if CPP_WORDSZ != 32 && CPP_WORDSZ != 64
 934    -> bad word size
 935 # endif
 936
 937 # ifdef PCR
 938 #   undef DYNAMIC_LOADING
 939 #   undef STACKBOTTOM
 940 #   undef HEURISTIC1
 941 #   undef HEURISTIC2
 942 #   undef PROC_VDB
 943 #   undef MPROTECT_VDB
 944 #   define PCR_VDB
 945 # endif
 946
 947 # ifdef SRC_M3
 948 /* Postponed for now. */
 949 #   undef PROC_VDB
 950 #   undef MPROTECT_VDB
 951 # endif
 952
 953 # ifdef SMALL_CONFIG
 954 /* Presumably not worth the space it takes. */
 955 #   undef PROC_VDB
 956 #   undef MPROTECT_VDB
 957 # endif
 958
 959 # if !defined(PCR_VDB) && !defined(PROC_VDB) && !defined(MPROTECT_VDB)
 960 #   define DEFAULT_VDB
 961 # endif
 962
 963 # if defined(IRIX_THREADS) && !defined(IRIX5)
 964 --> inconsistent configuration
 965 # endif
 966 # if defined(LINUX_THREADS) && !defined(LINUX)
 967 --> inconsistent configuration
 968 # endif
 969 # if defined(SOLARIS_THREADS) && !defined(SUNOS5)
 970 --> inconsistent configuration
 971 # endif
 972 # if defined(PCR) || defined(SRC_M3) || \
 973         defined(SOLARIS_THREADS) || defined(WIN32_THREADS) || \
 974         defined(IRIX_THREADS) || defined(LINUX_THREADS) || \
 975         defined(QUICK_THREADS)
 976 #   define THREADS
 977 # endif
 978
 979 # if defined(SPARC)
 980 #   define SAVE_CALL_CHAIN
 981 #   define ASM_CLEAR_CODE       /* Stack clearing is crucial, and we    */
 982                                 /* include assembly code to do it well. */
 983 # endif
 984
 985 # endif