libguile/__scm.h

   1 /* classes: h_files */
   2
   3 #ifndef __SCMH
   4 #define __SCMH
   5 /* Copyright (C) 1995,1996,1998,1999,2000,2001 Free Software Foundation, Inc.
   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, or (at your option)
  10  * 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 software; see the file COPYING.  If not, write to
  19  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20  * Boston, MA 02111-1307 USA
  21  *
  22  * As a special exception, the Free Software Foundation gives permission
  23  * for additional uses of the text contained in its release of GUILE.
  24  *
  25  * The exception is that, if you link the GUILE library with other files
  26  * to produce an executable, this does not by itself cause the
  27  * resulting executable to be covered by the GNU General Public License.
  28  * Your use of that executable is in no way restricted on account of
  29  * linking the GUILE library code into it.
  30  *
  31  * This exception does not however invalidate any other reasons why
  32  * the executable file might be covered by the GNU General Public License.
  33  *
  34  * This exception applies only to the code released by the
  35  * Free Software Foundation under the name GUILE.  If you copy
  36  * code from other Free Software Foundation releases into a copy of
  37  * GUILE, as the General Public License permits, the exception does
  38  * not apply to the code that you add in this way.  To avoid misleading
  39  * anyone as to the status of such modified files, you must delete
  40  * this exception notice from them.
  41  *
  42  * If you write modifications of your own for GUILE, it is your choice
  43  * whether to permit this exception to apply to your modifications.
  44  * If you do not wish that, delete this exception notice.  */
  45 \f
  46
  47 /* "What's the difference between _scm.h and __scm.h?"
  48
  49    _scm.h is not installed; it's only visible to the libguile sources
  50    themselves.
  51
  52    __scm.h is installed, and is #included by <libguile.h>.  If both
  53    the client and libguile need some piece of information, and it
  54    doesn't fit well into the header file for any particular module, it
  55    should go in __scm.h.  */
  56
  57
  58 /* {Supported Options}
  59  *
  60  * These may be defined or undefined.
  61  */
  62
  63 /* Old async mechanism */
  64 /* #define GUILE_OLD_ASYNC_CLICK */
  65
  66 /* #define GUILE_DEBUG_FREELIST */
  67
  68 /* If the compile FLAG `SCM_CAUTIOUS' is #defined then the number of
  69  * arguments is always checked for application of closures.  If the
  70  * compile FLAG `SCM_RECKLESS' is #defined then they are not checked.
  71  * Otherwise, number of argument checks for closures are made only when
  72  * the function position (whose value is the closure) of a combination is
  73  * not an ILOC or GLOC.  When the function position of a combination is a
  74  * symbol it will be checked only the first time it is evaluated because
  75  * it will then be replaced with an ILOC or GLOC.
  76  */
  77 #undef SCM_RECKLESS
  78 #define SCM_CAUTIOUS
  79
  80 /* After looking up a local for the first time, rewrite the
  81  * code graph, caching its position.
  82  */
  83 #define MEMOIZE_LOCALS
  84
  85 /* All the number support there is.
  86  */
  87 #define BIGNUMS
  88
  89 /* GC should relinquish empty cons-pair arenas. */
  90 /* cmm:FIXME look at this after done mangling the GC */
  91 /* #define GC_FREE_SEGMENTS */
  92
  93 /* Provide a scheme-accessible count-down timer that
  94  * generates a pseudo-interrupt.
  95  */
  96 #define TICKS
  97
  98
  99 /* Use engineering notation when converting numbers strings?
 100  */
 101 #undef ENGNOT
 102
 103 \f
 104 /* {Unsupported Options}
 105  *
 106  * These must be defined as given here.
 107  */
 108
 109
 110 #define CCLO
 111
 112 /* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
 113    have horrible plans for their unification.  */
 114 #undef SICP
 115
 116 \f
 117
 118 /* Random options (not yet supported or in final form). */
 119
 120 #define STACK_CHECKING
 121 #undef NO_CEVAL_STACK_CHECKING
 122
 123 \f
 124
 125 /* What did the configure script discover about the outside world?  */
 126 #include "libguile/scmconfig.h"
 127
 128 \f
 129
 130 /* {Debugging Options}
 131  *
 132  * These compile time options determine whether to include code that is only
 133  * useful for debugging guile itself or C level extensions to guile.  The
 134  * common prefix for all option macros of this kind is "SCM_DEBUG_".  It is
 135  * guaranteed that a macro named SCM_DEBUG_XXX is defined to be either 0 or 1,
 136  * i. e. there is no need to test for the undefined case.  This allows to use
 137  * these definitions comfortably in macro code, as in the following example:
 138  *   #define FOO do { if (SCM_DEBUG_XXX) bar(); else baz(); } while (0)
 139  * Any sane compiler will remove the unused branch without any performance
 140  * penalty for the resulting code.
 141  *
 142  * Note:  Some SCM_DEBUG_XXX options are not settable at configure time.
 143  * To change the value of such options you will have to edit this header
 144  * file or give suitable options to make, like:
 145  *   make all CFLAGS="-DSCM_DEBUG_XXX=1 ..."
 146  */
 147
 148
 149 /* The value of SCM_DEBUG determines the default for most of the not yet
 150  * defined debugging options.  This allows, for example, to enable most of the
 151  * debugging options by simply defining SCM_DEBUG as 1.
 152  */
 153 #ifndef SCM_DEBUG
 154 #define SCM_DEBUG 0
 155 #endif
 156
 157 /* If SCM_DEBUG_CELL_ACCESSES is set to 1, cell accesses will perform
 158  * exhaustive parameter checking:  It will be verified that cell parameters
 159  * actually point to a valid heap cell.  Note:  If this option is enabled,
 160  * guile will run about ten times slower than normally.
 161  */
 162 #ifndef SCM_DEBUG_CELL_ACCESSES
 163 #define SCM_DEBUG_CELL_ACCESSES SCM_DEBUG
 164 #endif
 165
 166 /* If SCM_DEBUG_DEPRECATED is set to 1, deprecated code is not compiled.  This
 167  * can be used by developers to get rid of references to deprecated code.
 168  */
 169 #ifndef SCM_DEBUG_DEPRECATED
 170 #define SCM_DEBUG_DEPRECATED SCM_DEBUG
 171 #endif
 172
 173 /* If SCM_DEBUG_INTERRUPTS is set to 1, with every deferring and allowing of
 174  * interrupts a consistency check will be performed.
 175  */
 176 #ifndef SCM_DEBUG_INTERRUPTS
 177 #define SCM_DEBUG_INTERRUPTS SCM_DEBUG
 178 #endif
 179
 180 /* If SCM_DEBUG_REST_ARGUMENT is set to 1, functions that take rest arguments
 181  * will check whether the rest arguments are actually passed as a proper list.
 182  * Otherwise, if SCM_DEBUG_REST_ARGUMENT is 0, functions that take rest
 183  * arguments will take it for granted that these are passed as a proper list.
 184  */
 185 #ifndef SCM_DEBUG_REST_ARGUMENT
 186 #define SCM_DEBUG_REST_ARGUMENT SCM_DEBUG
 187 #endif
 188
 189 /* Use this for _compile time_ type checking only, since the compiled result
 190  * will be quite inefficient.  The right way to make use of this option is to
 191  * do a 'make clean; make CFLAGS=-DSCM_DEBUG_TYPING_STRICTNESS=1', fix your
 192  * errors, and then do 'make clean; make'.
 193  */
 194 #ifndef SCM_DEBUG_TYPING_STRICTNESS
 195 #define SCM_DEBUG_TYPING_STRICTNESS 0
 196 #endif
 197
 198 /* If SCM_ENABLE_VCELLS is set to 1, a couple of functions that deal
 199  * with vcells are defined for compatability reasons.  Supporting
 200  * vcells reduces performance however.
 201  *
 202  * We use a dedicated macro instead of just SCM_DEBUG_DEPRECATED so
 203  * that code the belongs to the `vcell' feature is easier to find.
 204  */
 205 #define SCM_ENABLE_VCELLS !SCM_DEBUG_DEPRECATED
 206
 207 \f
 208
 209 #ifdef HAVE_LONG_LONGS
 210
 211 /* Some auto-generated .h files contain unused prototypes
 212  * that need these typedefs.
 213  */
 214
 215 #if (SCM_DEBUG_DEPRECATED == 0)
 216 typedef long long long_long;
 217 typedef unsigned long long ulong_long;
 218 #endif
 219
 220 #endif /* HAVE_LONG_LONGS */
 221
 222 \f
 223
 224 /* {Architecture and compiler properties}
 225  *
 226  * Guile as of today can only work on systems which fulfill at least the
 227  * following requirements:
 228  * - long ints have at least 32 bits.
 229  *   Guile's type system is based on this assumption.
 230  * - long ints consist of at least four characters.
 231  *   It is assumed that cells, i. e. pairs of long ints, are eight character
 232  *   aligned, because three bits of a cell pointer are used for type data.
 233  * - sizeof (void*) == sizeof (long int)
 234  *   Pointers are stored in SCM objects, and sometimes SCM objects are passed
 235  *   as void*.  Thus, there has to be a one-to-one correspondence.
 236  * - numbers are encoded using two's complement.
 237  *   The implementation of the bitwise scheme level operations is based on
 238  *   this assumption.
 239  * - ... add more
 240  */
 241
 242 #ifdef HAVE_LIMITS_H
 243 # include <limits.h>
 244 #endif
 245
 246 #ifdef CHAR_BIT
 247 # define SCM_CHAR_BIT CHAR_BIT
 248 #else
 249 # define SCM_CHAR_BIT 8
 250 #endif
 251
 252 #ifdef LONG_BIT
 253 # define SCM_LONG_BIT LONG_BIT
 254 #else
 255 # define SCM_LONG_BIT (SCM_CHAR_BIT * sizeof (long) / sizeof (char))
 256 #endif
 257
 258 #define SCM_BITS_LENGTH (SCM_CHAR_BIT * SCM_SIZEOF_BITS_T)
 259
 260 #ifdef UCHAR_MAX
 261 # define SCM_CHAR_CODE_LIMIT (UCHAR_MAX + 1L)
 262 #else
 263 # define SCM_CHAR_CODE_LIMIT 256L
 264 #endif
 265
 266 \f
 267
 268 #ifdef STDC_HEADERS
 269 # include <stdlib.h>
 270 # if HAVE_SYS_TYPES_H
 271 #  include <sys/types.h>
 272 # endif
 273 # if HAVE_SYS_STDTYPES_H
 274 #  include <sys/stdtypes.h>
 275 # endif
 276 #  include <stddef.h>
 277 #endif /* def STDC_HEADERS */
 278
 279 #if (SCM_DEBUG_DEPRECATED == 0)
 280 # define scm_sizet size_t
 281 #endif
 282
 283 \f
 284
 285 #include "libguile/tags.h"
 286
 287 \f
 288 #ifdef vms
 289 # ifndef CHEAP_CONTINUATIONS
 290    typedef int jmp_buf[17];
 291    extern int setjump(jmp_buf env);
 292    extern int longjump(jmp_buf env, int ret);
 293 #  define setjmp setjump
 294 #  define longjmp longjump
 295 # else
 296 #  include <setjmp.h>
 297 # endif
 298 #else                           /* ndef vms */
 299 # ifdef _CRAY1
 300     typedef int jmp_buf[112];
 301     extern int setjump(jmp_buf env);
 302     extern int longjump(jmp_buf env, int ret);
 303 #  define setjmp setjump
 304 #  define longjmp longjump
 305 # else                          /* ndef _CRAY1 */
 306 #  include <setjmp.h>
 307 # endif                         /* ndef _CRAY1 */
 308 #endif                          /* ndef vms */
 309
 310 /* James Clark came up with this neat one instruction fix for
 311  * continuations on the SPARC.  It flushes the register windows so
 312  * that all the state of the process is contained in the stack.
 313  */
 314
 315 #ifdef sparc
 316 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 317 #else
 318 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 319 #endif
 320
 321 /* If stack is not longword aligned then
 322  */
 323
 324 /* #define SHORT_ALIGN */
 325 #ifdef THINK_C
 326 # define SHORT_ALIGN
 327 #endif
 328 #ifdef MSDOS
 329 # define SHORT_ALIGN
 330 #endif
 331 #ifdef atarist
 332 # define SHORT_ALIGN
 333 #endif
 334
 335 #ifdef SHORT_ALIGN
 336 typedef short SCM_STACKITEM;
 337 #else
 338 typedef long SCM_STACKITEM;
 339 #endif
 340 \f
 341
 342 #ifndef USE_THREADS
 343 #define SCM_CRITICAL_SECTION_START
 344 #define SCM_CRITICAL_SECTION_END
 345 #define SCM_THREAD_SWITCHING_CODE
 346 #endif
 347
 348 #ifdef GUILE_OLD_ASYNC_CLICK
 349 extern unsigned int scm_async_clock;
 350
 351 #define SCM_ASYNC_TICK \
 352 do { \
 353   if (0 == --scm_async_clock) \
 354     scm_async_click (); \
 355 } while(0)
 356 #else
 357 extern int scm_asyncs_pending_p;
 358
 359 #define SCM_ASYNC_TICK /*fixme* should change names */ \
 360 do { \
 361   if (scm_asyncs_pending_p) \
 362     scm_async_click (); \
 363 } while (0)
 364 #endif
 365
 366 #if (SCM_DEBUG_INTERRUPTS == 1)
 367 #include <stdio.h>
 368 #define SCM_CHECK_NOT_DISABLED \
 369   do { \
 370     if (scm_ints_disabled) \
 371       fprintf(stderr, "ints already disabled (at %s:%d)\n", \
 372               __FILE__, __LINE__); \
 373   } while (0)
 374
 375 #define SCM_CHECK_NOT_ENABLED \
 376   do { \
 377     if (!scm_ints_disabled) \
 378       fprintf(stderr, "ints already enabled (at %s:%d)\n", \
 379               __FILE__, __LINE__); \
 380   } while (0)
 381
 382 #else
 383 #define SCM_CHECK_NOT_DISABLED
 384 #define SCM_CHECK_NOT_ENABLED
 385 #endif
 386
 387
 388 /* Anthony Green writes:
 389    When the compiler sees...
 390            DEFER_INTS;
 391            [critical code here]
 392            ALLOW_INTS;
 393    ...it doesn't actually promise to keep the critical code within the
 394    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 395    schedule it outside of the magic defined in those macros.
 396
 397    However, GCC's volatile asm feature forms a barrier over which code is
 398    never moved. So if you add...
 399            asm ("");
 400    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 401    code will always remain in place.  asm's without inputs or outputs
 402    are implicitly volatile. */
 403 #ifdef __GNUC__
 404 #define SCM_FENCE asm /* volatile */ ("")
 405 #else
 406 #define SCM_FENCE
 407 #endif
 408
 409 #define SCM_DEFER_INTS \
 410 do { \
 411   SCM_FENCE; \
 412   SCM_CHECK_NOT_DISABLED; \
 413   SCM_CRITICAL_SECTION_START; \
 414   SCM_FENCE; \
 415   scm_ints_disabled = 1; \
 416   SCM_FENCE; \
 417 } while (0)
 418
 419
 420 #define SCM_ALLOW_INTS_ONLY \
 421 do { \
 422   SCM_CRITICAL_SECTION_END; \
 423   scm_ints_disabled = 0; \
 424 } while (0)
 425
 426
 427 #define SCM_ALLOW_INTS \
 428 do { \
 429   SCM_FENCE; \
 430   SCM_CHECK_NOT_ENABLED; \
 431   SCM_CRITICAL_SECTION_END; \
 432   SCM_FENCE; \
 433   scm_ints_disabled = 0; \
 434   SCM_FENCE; \
 435   SCM_THREAD_SWITCHING_CODE; \
 436   SCM_FENCE; \
 437 } while (0)
 438
 439
 440 #define SCM_REDEFER_INTS  \
 441 do { \
 442   SCM_FENCE; \
 443   SCM_CRITICAL_SECTION_START; \
 444   ++scm_ints_disabled; \
 445   SCM_FENCE; \
 446 } while (0)
 447
 448
 449 #define SCM_REALLOW_INTS \
 450 do { \
 451   SCM_FENCE; \
 452   SCM_CRITICAL_SECTION_END; \
 453   SCM_FENCE; \
 454   --scm_ints_disabled; \
 455   SCM_FENCE; \
 456 } while (0)
 457
 458
 459 #define SCM_TICK \
 460 do { \
 461   SCM_ASYNC_TICK; \
 462   SCM_THREAD_SWITCHING_CODE; \
 463 } while (0)
 464
 465 \f
 466
 467 /* Classification of critical sections
 468  *
 469  * When Guile moves to POSIX threads, it won't be possible to prevent
 470  * context switching.  In fact, the whole idea of context switching is
 471  * bogus if threads are run by different processors.  Therefore, we
 472  * must ultimately eliminate all critical sections or enforce them by
 473  * use of mutecis.
 474  *
 475  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 476  * be classified and replaced by one of the delimiters below.  If you
 477  * understand what this is all about, I'd like to encourage you to
 478  * help with this task.  The set of classes below must of course be
 479  * incrementally augmented.
 480  *
 481  * MDJ 980419 <djurfeldt@nada.kth.se>
 482  */
 483
 484 /* A sections
 485  *
 486  * Allocation of a cell with type tag in the CAR.
 487  *
 488  * With POSIX threads, each thread will have a private pool of free
 489  * cells.  Therefore, this type of section can be removed.  But!  It
 490  * is important that the CDR is initialized first (with the CAR still
 491  * indicating a free cell) so that we can guarantee a consistent heap
 492  * at all times.
 493  */
 494
 495 #define SCM_ENTER_A_SECTION SCM_CRITICAL_SECTION_START
 496 #define SCM_EXIT_A_SECTION SCM_CRITICAL_SECTION_END
 497
 498 \f
 499
 500 /** SCM_ASSERT
 501  **
 502  **/
 503
 504
 505 #ifdef SCM_RECKLESS
 506 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 507 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg)
 508 #define SCM_ASRTGO(_cond, _label)
 509 #else
 510 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 511         if (!(_cond)) \
 512           scm_wrong_type_arg (_subr, _pos, _arg)
 513 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg) \
 514         if (!(_cond)) \
 515           scm_wrong_type_arg_msg(_subr, _pos, _arg, _msg)
 516 #define SCM_ASRTGO(_cond, _label) \
 517         if (!(_cond)) \
 518           goto _label
 519 #endif
 520
 521 /*
 522  * SCM_WTA_DISPATCH
 523  */
 524
 525 /* Dirk:FIXME:: In all of the SCM_WTA_DISPATCH_* macros it is assumed that
 526  * 'gf' is zero if uninitialized.  It would be cleaner if some valid SCM value
 527  * like SCM_BOOL_F or SCM_UNDEFINED was chosen.
 528  */
 529
 530 extern SCM scm_call_generic_0 (SCM gf);
 531
 532 #define SCM_WTA_DISPATCH_0(gf, subr)                            \
 533   return (SCM_UNPACK (gf)                                       \
 534           ? scm_call_generic_0 ((gf))                           \
 535           : (scm_error_num_args_subr ((subr)), SCM_UNSPECIFIED))
 536 #define SCM_GASSERT0(cond, gf, subr) \
 537   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (subr))
 538
 539 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 540
 541 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr)                   \
 542   return (SCM_UNPACK (gf)                                       \
 543           ? scm_call_generic_1 ((gf), (a1))                     \
 544           : (scm_wrong_type_arg ((subr), (pos), (a1)), SCM_UNSPECIFIED))
 545 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 546   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 547
 548 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 549
 550 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr)                       \
 551   return (SCM_UNPACK (gf)                                               \
 552           ? scm_call_generic_2 ((gf), (a1), (a2))                       \
 553           : (scm_wrong_type_arg ((subr), (pos),                         \
 554                                  (pos) == SCM_ARG1 ? (a1) : (a2)),      \
 555              SCM_UNSPECIFIED))
 556 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 557   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 558
 559 extern SCM scm_apply_generic (SCM gf, SCM args);
 560
 561 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr)                           \
 562   return (SCM_UNPACK (gf)                                                 \
 563           ? scm_apply_generic ((gf), (args))                              \
 564           : (scm_wrong_type_arg ((subr), (pos),                           \
 565                                  scm_list_ref ((args),                    \
 566                                                SCM_MAKINUM ((pos) - 1))), \
 567              SCM_UNSPECIFIED))
 568 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 569   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 570
 571 #ifndef SCM_MAGIC_SNARFER
 572 /* Let these macros pass through if
 573    we are snarfing;  thus we can tell the
 574    difference between the use of an actual
 575    number vs. the use of one of these macros --
 576    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 577    constructs must match the formal argument name,
 578    but using SCM_ARG* avoids the test */
 579
 580 #define SCM_ARGn                0
 581 #define SCM_ARG1                1
 582 #define SCM_ARG2                2
 583 #define SCM_ARG3                3
 584 #define SCM_ARG4                4
 585 #define SCM_ARG5                5
 586 #define SCM_ARG6                6
 587 #define SCM_ARG7                7
 588
 589 #if (SCM_DEBUG_DEPRECATED == 0)
 590
 591 /* Use SCM_WRONG_NUM_ARGS instead of: */
 592 #define SCM_WNA                 8
 593
 594 /* Use SCM_ASSERT_RANGE or SCM_VALIDATE_XXX_RANGE instead of: */
 595 #define SCM_OUTOFRANGE         10
 596
 597 /* Use scm_memory_error instead of: */
 598 #define SCM_NALLOC             11
 599
 600 #define SCM_HUP_SIGNAL         14
 601 #define SCM_INT_SIGNAL         15
 602 #define SCM_FPE_SIGNAL         16
 603 #define SCM_BUS_SIGNAL         17
 604 #define SCM_SEGV_SIGNAL        18
 605 #define SCM_ALRM_SIGNAL        19
 606 #define SCM_GC_SIGNAL          20
 607 #define SCM_TICK_SIGNAL        21
 608 #define SCM_SIG_ORD(X)         ((X) - SCM_HUP_SIGNAL)
 609 #define SCM_ORD_SIG(X)         ((X) + SCM_HUP_SIGNAL)
 610 #define SCM_NUM_SIGS           (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 611
 612 #endif  /* SCM_DEBUG_DEPRECATED == 0 */
 613
 614 #endif /* SCM_MAGIC_SNARFER */
 615
 616 \f
 617
 618 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 619  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 620  * SCM if errors were encountered.  The return code can be explicitly
 621  * specified in a SCM program with (scm_quit <n>).
 622  */
 623
 624 #ifndef SCM_EXIT_SUCCESS
 625 #ifdef vms
 626 #define SCM_EXIT_SUCCESS 1
 627 #else
 628 #define SCM_EXIT_SUCCESS 0
 629 #endif /* def vms */
 630 #endif /* ndef SCM_EXIT_SUCCESS */
 631 #ifndef SCM_EXIT_FAILURE
 632 #ifdef vms
 633 #define SCM_EXIT_FAILURE 2
 634 #else
 635 #define SCM_EXIT_FAILURE 1
 636 #endif /* def vms */
 637 #endif /* ndef SCM_EXIT_FAILURE */
 638
 639 \f
 640
 641 #endif  /* __SCMH */
 642
 643 /*
 644   Local Variables:
 645   c-file-style: "gnu"
 646   End:
 647 */