libguile/__scm.h

   1 /* classes: h_files */
   2
   3 #ifndef SCM___SCM_H
   4 #define SCM___SCM_H
   5
   6 /* Copyright (C) 1995,1996,1998,1999,2000,2001,2002,2003 Free Software Foundation, Inc.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this software; see the file COPYING.  If not, write to
  20  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  21  * Boston, MA 02111-1307 USA
  22  *
  23  * As a special exception, the Free Software Foundation gives permission
  24  * for additional uses of the text contained in its release of GUILE.
  25  *
  26  * The exception is that, if you link the GUILE library with other files
  27  * to produce an executable, this does not by itself cause the
  28  * resulting executable to be covered by the GNU General Public License.
  29  * Your use of that executable is in no way restricted on account of
  30  * linking the GUILE library code into it.
  31  *
  32  * This exception does not however invalidate any other reasons why
  33  * the executable file might be covered by the GNU General Public License.
  34  *
  35  * This exception applies only to the code released by the
  36  * Free Software Foundation under the name GUILE.  If you copy
  37  * code from other Free Software Foundation releases into a copy of
  38  * GUILE, as the General Public License permits, the exception does
  39  * not apply to the code that you add in this way.  To avoid misleading
  40  * anyone as to the status of such modified files, you must delete
  41  * this exception notice from them.
  42  *
  43  * If you write modifications of your own for GUILE, it is your choice
  44  * whether to permit this exception to apply to your modifications.
  45  * If you do not wish that, delete this exception notice.  */
  46
  47 \f
  48
  49 /**********************************************************************
  50  This file is Guile's central public header.
  51
  52  When included by other files, this file should preceed any include
  53  other than __scm.h.
  54
  55  Under *NO* circumstances should new items be added to the global
  56  namespace (via adding #define, typedef, or similar to this file) with
  57  generic names.  This usually means that any new names should be
  58  prefixed by either SCM_ or GUILE_.  i.e. do *not* #define HAVE_FOO or
  59  SIZEOF_BAR.  See configure.in, gen-scmconfig.h.in, and
  60  gen-scmconfig.c for examples of how to properly handle this issue.
  61  The main documentation is in gen-scmconfig.c.
  62
  63  "What's the difference between _scm.h and __scm.h?"
  64
  65    _scm.h is not installed; it's only visible to the libguile sources
  66    themselves, and it includes config.h, the private config header.
  67
  68    __scm.h is installed, and is #included by <libguile.h>.  If both
  69    the client and libguile need some piece of information, and it
  70    doesn't fit well into the header file for any particular module, it
  71    should go in __scm.h.  __scm.h includes scmconfig.h, the public
  72    config header.
  73  **********************************************************************/
  74
  75 /* What did the configure script discover about the outside world?  */
  76 #include "libguile/scmconfig.h"
  77
  78 \f
  79
  80 /* {Compiler hints}
  81  *
  82  * The following macros are used to provide additional information for the
  83  * compiler, which may help to do better error checking and code
  84  * optimization.  A second benefit of these macros is, that they also provide
  85  * additional information to the developers.
  86  */
  87
  88 /* The macro SCM_NORETURN indicates that a function will never return.
  89  * Examples:
  90  *   1) int foo (char arg) SCM_NORETURN;
  91  */
  92 #ifdef __GNUC__
  93 #define SCM_NORETURN __attribute__ ((noreturn))
  94 #else
  95 #define SCM_NORETURN
  96 #endif
  97
  98 /* The macro SCM_UNUSED indicates that a function, function argument or
  99  * variable may potentially be unused.
 100  * Examples:
 101  *   1) static int unused_function (char arg) SCM_UNUSED;
 102  *   2) int foo (char unused_argument SCM_UNUSED);
 103  *   3) int unused_variable SCM_UNUSED;
 104  */
 105 #ifdef __GNUC__
 106 #define SCM_UNUSED __attribute__ ((unused))
 107 #else
 108 #define SCM_UNUSED
 109 #endif
 110
 111
 112 /* {Supported Options}
 113  *
 114  * These may be defined or undefined.
 115  */
 116
 117 /* #define GUILE_DEBUG_FREELIST */
 118
 119 /* All the number support there is.
 120  */
 121 #define BIGNUMS
 122
 123 /* GC should relinquish empty cons-pair arenas. */
 124 /* cmm:FIXME look at this after done mangling the GC */
 125 /* #define GC_FREE_SEGMENTS */
 126
 127 /* Provide a scheme-accessible count-down timer that
 128  * generates a pseudo-interrupt.
 129  */
 130 #define TICKS
 131
 132
 133 /* Use engineering notation when converting numbers strings?
 134  */
 135 #undef ENGNOT
 136
 137 \f
 138 /* {Unsupported Options}
 139  *
 140  * These must be defined as given here.
 141  */
 142
 143
 144 #define CCLO
 145
 146 /* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
 147    have horrible plans for their unification.  */
 148 #undef SICP
 149
 150 \f
 151
 152 /* Random options (not yet supported or in final form). */
 153
 154 #define STACK_CHECKING
 155 #undef NO_CEVAL_STACK_CHECKING
 156
 157 \f
 158
 159 /* SCM_API is a macro prepended to all function and data definitions
 160    which should be exported or imported in the resulting dynamic link
 161    library (DLL) in the Win32 port. */
 162
 163 #if defined (SCM_IMPORT)
 164 # define SCM_API __declspec (dllimport) extern
 165 #elif defined (SCM_EXPORT) || defined (DLL_EXPORT)
 166 # define SCM_API __declspec (dllexport) extern
 167 #else
 168 # define SCM_API extern
 169 #endif
 170
 171 \f
 172
 173 /* {Debugging Options}
 174  *
 175  * These compile time options determine whether to include code that is only
 176  * useful for debugging guile itself or C level extensions to guile.  The
 177  * common prefix for all option macros of this kind is "SCM_DEBUG_".  It is
 178  * guaranteed that a macro named SCM_DEBUG_XXX is always defined (typically to
 179  * either 0 or 1), i. e. there is no need to test for the undefined case.
 180  * This allows to use these definitions comfortably within code, as in the
 181  * following example:
 182  *   #define FOO do { if (SCM_DEBUG_XXX) bar(); else baz(); } while (0)
 183  * Any sane compiler will remove the unused branch without any performance
 184  * penalty for the resulting code.
 185  *
 186  * Note:  Some SCM_DEBUG_XXX options are not settable at configure time.
 187  * To change the value of such options you will have to edit this header
 188  * file or give suitable options to make, like:
 189  *   make all CFLAGS="-DSCM_DEBUG_XXX=1 ..."
 190  */
 191
 192
 193 /* The value of SCM_DEBUG determines the default for most of the not yet
 194  * defined debugging options.  This allows, for example, to enable most of the
 195  * debugging options by simply defining SCM_DEBUG as 1.
 196  */
 197 #ifndef SCM_DEBUG
 198 #define SCM_DEBUG 0
 199 #endif
 200
 201 /* If SCM_DEBUG_CELL_ACCESSES is set to 1, cell accesses will perform
 202  * exhaustive parameter checking:  It will be verified that cell parameters
 203  * actually point to a valid heap cell.  Note:  If this option is enabled,
 204  * guile will run about ten times slower than normally.
 205  */
 206 #ifndef SCM_DEBUG_CELL_ACCESSES
 207 #define SCM_DEBUG_CELL_ACCESSES SCM_DEBUG
 208 #endif
 209
 210 /* If SCM_DEBUG_INTERRUPTS is set to 1, with every deferring and allowing of
 211  * interrupts a consistency check will be performed.
 212  */
 213 #ifndef SCM_DEBUG_INTERRUPTS
 214 #define SCM_DEBUG_INTERRUPTS SCM_DEBUG
 215 #endif
 216
 217 /* If SCM_DEBUG_PAIR_ACCESSES is set to 1, accesses to cons cells will be
 218  * exhaustively checked.  Note:  If this option is enabled, guile will run
 219  * slower than normally.
 220  */
 221 #ifndef SCM_DEBUG_PAIR_ACCESSES
 222 #define SCM_DEBUG_PAIR_ACCESSES SCM_DEBUG
 223 #endif
 224
 225 /* If SCM_DEBUG_REST_ARGUMENT is set to 1, functions that take rest arguments
 226  * will check whether the rest arguments are actually passed as a proper list.
 227  * Otherwise, if SCM_DEBUG_REST_ARGUMENT is 0, functions that take rest
 228  * arguments will take it for granted that these are passed as a proper list.
 229  */
 230 #ifndef SCM_DEBUG_REST_ARGUMENT
 231 #define SCM_DEBUG_REST_ARGUMENT SCM_DEBUG
 232 #endif
 233
 234 /* The macro SCM_DEBUG_TYPING_STRICTNESS indicates what level of type checking
 235  * shall be performed with respect to the use of the SCM datatype.  The macro
 236  * may be defined to one of the values 0, 1 and 2.
 237  *
 238  * A value of 0 means that there will be no compile time type checking, since
 239  * the SCM datatype will be declared as an integral type.  This setting should
 240  * only be used on systems, where casting from integral types to pointers may
 241  * lead to loss of bit information.
 242  *
 243  * A value of 1 means that there will an intermediate level of compile time
 244  * type checking, since the SCM datatype will be declared as a pointer to an
 245  * undefined struct.  This setting is the default, since it does not cost
 246  * anything in terms of performance or code size.
 247  *
 248  * A value of 2 provides a maximum level of compile time type checking since
 249  * the SCM datatype will be declared as a struct.  This setting should be used
 250  * for _compile time_ type checking only, since the compiled result is likely
 251  * to be quite inefficient.  The right way to make use of this option is to do
 252  * a 'make clean; make CFLAGS=-DSCM_DEBUG_TYPING_STRICTNESS=2', fix your
 253  * errors, and then do 'make clean; make'.
 254  */
 255 #ifndef SCM_DEBUG_TYPING_STRICTNESS
 256 #define SCM_DEBUG_TYPING_STRICTNESS 1
 257 #endif
 258
 259 /* If SCM_DEBUG_DEBUGGING_SUPPORT is set to 1, guile will provide a set of
 260  * special functions that support debugging with a debugger like gdb or
 261  * debugging of guile internals on the scheme level.  The behaviour of guile
 262  * is not changed by this macro, only the set of functions that are available
 263  * will differ.  All functions that are introduced this way have the prefix
 264  * 'scm_dbg_' on the C level and the prefix 'dbg-' on the scheme level.  This
 265  * allows to easily determine the set of support functions, given that your
 266  * debugger or repl provide automatic name completion.  Note that these
 267  * functions are intended to be used during interactive debugging sessions
 268  * only.  They are not considered part of guile's official API.  They may
 269  * change or disappear without notice or deprecation phase.
 270  */
 271 #ifndef SCM_DEBUG_DEBUGGING_SUPPORT
 272 #define SCM_DEBUG_DEBUGGING_SUPPORT SCM_DEBUG
 273 #endif
 274
 275 \f
 276
 277 /* {Feature Options}
 278  *
 279  * These compile time options determine whether code for certain features
 280  * should be compiled into guile.  The common prefix for all option macros
 281  * of this kind is "SCM_ENABLE_".  It is guaranteed that a macro named
 282  * SCM_ENABLE_XXX is defined to be either 0 or 1, i. e. there is no need to
 283  * test for the undefined case.  This allows to use these definitions
 284  * comfortably within code, as in the following example:
 285  *   #define FOO do { if (SCM_ENABLE_XXX) bar(); else baz(); } while (0)
 286  * Any sane compiler will remove the unused branch without any performance
 287  * penalty for the resulting code.
 288  *
 289  * Note:  Some SCM_ENABLE_XXX options are not settable at configure time.
 290  * To change the value of such options you will have to edit this header
 291  * file or give suitable options to make, like:
 292  *   make all CFLAGS="-DSCM_ENABLE_XXX=1 ..."
 293  */
 294
 295 /* If SCM_ENABLE_DEPRECATED is set to 1, deprecated code will be included in
 296  * guile, as well as some functions to issue run-time warnings about uses of
 297  * deprecated functions.
 298  */
 299 #ifndef SCM_ENABLE_DEPRECATED
 300 #define SCM_ENABLE_DEPRECATED 0
 301 #endif
 302
 303 \f
 304
 305 /* {Architecture and compiler properties}
 306  *
 307  * Guile as of today can only work on systems which fulfill at least the
 308  * following requirements:
 309  *
 310  * - scm_t_bits and SCM variables have at least 32 bits.
 311  *   Guile's type system is based on this assumption.
 312  *
 313  * - sizeof (scm_t_bits) >= sizeof (void*) and sizeof (SCM) >= sizeof (void*)
 314  *   Guile's type system is based on this assumption, since it must be
 315  *   possible to store pointers to cells on the heap in scm_t_bits and SCM
 316  *   variables.
 317  *
 318  * - sizeof (scm_t_bits) >= 4 and sizeof (scm_t_bits) is a power of 2.
 319  *   Guile's type system is based on this assumption.  In particular, it is
 320  *   assumed that cells, i. e. pairs of scm_t_bits variables, are eight
 321  *   character aligned.  This is because three bits of a scm_t_bits variable
 322  *   that is holding a pointer to a cell on the heap must be available for
 323  *   storing type data.
 324  *
 325  * - sizeof (scm_t_bits) <= sizeof (void*) and sizeof (SCM) <= sizeof (void*)
 326  *   In some parts of guile, scm_t_bits and SCM variables are passed to
 327  *   functions as void* arguments.  Together with the requirement above, this
 328  *   requires a one-to-one correspondence between the size of a void* and the
 329  *   sizes of scm_t_bits and SCM variables.
 330  *
 331  * - numbers are encoded using two's complement.
 332  *   The implementation of the bitwise scheme level operations is based on
 333  *   this assumption.
 334  *
 335  * - ... add more
 336  */
 337
 338 #ifdef CHAR_BIT
 339 # define SCM_CHAR_BIT CHAR_BIT
 340 #else
 341 # define SCM_CHAR_BIT 8
 342 #endif
 343
 344 #ifdef LONG_BIT
 345 # define SCM_LONG_BIT LONG_BIT
 346 #else
 347 # define SCM_LONG_BIT (SCM_CHAR_BIT * sizeof (long) / sizeof (char))
 348 #endif
 349
 350 #ifdef UCHAR_MAX
 351 # define SCM_CHAR_CODE_LIMIT (UCHAR_MAX + 1L)
 352 #else
 353 # define SCM_CHAR_CODE_LIMIT 256L
 354 #endif
 355
 356 #define SCM_I_UTYPE_MAX(type)      ((type)-1)
 357 #define SCM_I_TYPE_MAX(type,umax)  ((type)((umax)/2))
 358 #define SCM_I_TYPE_MIN(type,umax)  (-((type)((umax)/2))-1)
 359
 360 #define SCM_T_UINT8_MAX   SCM_I_UTYPE_MAX(scm_t_uint8)
 361 #define SCM_T_INT8_MIN    SCM_I_TYPE_MIN(scm_t_int8,SCM_T_UINT8_MAX)
 362 #define SCM_T_INT8_MAX    SCM_I_TYPE_MAX(scm_t_int8,SCM_T_UINT8_MAX)
 363
 364 #define SCM_T_UINT16_MAX  SCM_I_UTYPE_MAX(scm_t_uint16)
 365 #define SCM_T_INT16_MIN   SCM_I_TYPE_MIN(scm_t_int16,SCM_T_UINT16_MAX)
 366 #define SCM_T_INT16_MAX   SCM_I_TYPE_MAX(scm_t_int16,SCM_T_UINT16_MAX)
 367
 368 #define SCM_T_UINT32_MAX  SCM_I_UTYPE_MAX(scm_t_uint32)
 369 #define SCM_T_INT32_MIN   SCM_I_TYPE_MIN(scm_t_int32,SCM_T_UINT32_MAX)
 370 #define SCM_T_INT32_MAX   SCM_I_TYPE_MAX(scm_t_int32,SCM_T_UINT32_MAX)
 371
 372 #if SCM_HAVE_T_INT64
 373 #define SCM_T_UINT64_MAX  SCM_I_UTYPE_MAX(scm_t_uint64)
 374 #define SCM_T_INT64_MIN   SCM_I_TYPE_MIN(scm_t_int64,SCM_T_UINT64_MAX)
 375 #define SCM_T_INT64_MAX   SCM_I_TYPE_MAX(scm_t_int64,SCM_T_UINT64_MAX)
 376 #endif
 377
 378 #if SCM_SIZEOF_LONG_LONG
 379 #define SCM_I_ULLONG_MAX  SCM_I_UTYPE_MAX(unsigned long long)
 380 #define SCM_I_LLONG_MIN   SCM_I_TYPE_MIN(long long,SCM_I_ULLONG_MAX)
 381 #define SCM_I_LLONG_MAX   SCM_I_TYPE_MAX(long long,SCM_I_ULLONG_MAX)
 382 #endif
 383
 384 #define SCM_T_UINTMAX_MAX SCM_I_UTYPE_MAX(scm_t_uintmax)
 385 #define SCM_T_INTMAX_MIN  SCM_I_TYPE_MIN(scm_t_intmax,SCM_T_UINTMAX_MAX)
 386 #define SCM_T_INTMAX_MAX  SCM_I_TYPE_MAX(scm_t_intmax,SCM_T_UINTMAX_MAX)
 387
 388 #define SCM_I_SIZE_MAX    SCM_I_UTYPE_MAX(size_t)
 389 #define SCM_I_SSIZE_MIN   SCM_I_TYPE_MIN(ssize_t,SCM_I_SIZE_MAX)
 390 #define SCM_I_SSIZE_MAX   SCM_I_TYPE_MAX(ssize_t,SCM_I_SIZE_MAX)
 391
 392 \f
 393
 394 #include "libguile/tags.h"
 395
 396 \f
 397 #ifdef vms
 398 # ifndef CHEAP_CONTINUATIONS
 399    typedef int jmp_buf[17];
 400    extern int setjump(jmp_buf env);
 401    extern int longjump(jmp_buf env, int ret);
 402 #  define setjmp setjump
 403 #  define longjmp longjump
 404 # else
 405 #  include <setjmp.h>
 406 # endif
 407 #else                           /* ndef vms */
 408 # ifdef _CRAY1
 409     typedef int jmp_buf[112];
 410     extern int setjump(jmp_buf env);
 411     extern int longjump(jmp_buf env, int ret);
 412 #  define setjmp setjump
 413 #  define longjmp longjump
 414 # else                          /* ndef _CRAY1 */
 415 #  include <setjmp.h>
 416 # endif                         /* ndef _CRAY1 */
 417 #endif                          /* ndef vms */
 418
 419 /* James Clark came up with this neat one instruction fix for
 420  * continuations on the SPARC.  It flushes the register windows so
 421  * that all the state of the process is contained in the stack.
 422  */
 423
 424 #if defined (sparc) || defined (__sparc__) || defined (__sparc)
 425 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 426 #else
 427 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 428 #endif
 429
 430 /* If stack is not longword aligned then
 431  */
 432
 433 /* #define SHORT_ALIGN */
 434 #ifdef THINK_C
 435 # define SHORT_ALIGN
 436 #endif
 437 #ifdef MSDOS
 438 # define SHORT_ALIGN
 439 #endif
 440 #ifdef atarist
 441 # define SHORT_ALIGN
 442 #endif
 443
 444 #ifdef SHORT_ALIGN
 445 typedef short SCM_STACKITEM;
 446 #else
 447 typedef long SCM_STACKITEM;
 448 #endif
 449
 450 /* Cast pointer through (void *) in order to avoid compiler warnings
 451    when strict aliasing is enabled */
 452 #define SCM_STACK_PTR(ptr) ((SCM_STACKITEM *) (void *) (ptr))
 453 \f
 454
 455 #define SCM_ASYNC_TICK /*fixme* should change names */ \
 456 do { \
 457   if (SCM_I_CURRENT_THREAD->pending_asyncs) \
 458     scm_async_click (); \
 459 } while (0)
 460
 461
 462 /* Anthony Green writes:
 463    When the compiler sees...
 464            DEFER_INTS;
 465            [critical code here]
 466            ALLOW_INTS;
 467    ...it doesn't actually promise to keep the critical code within the
 468    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 469    schedule it outside of the magic defined in those macros.
 470
 471    However, GCC's volatile asm feature forms a barrier over which code is
 472    never moved. So if you add...
 473            asm ("");
 474    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 475    code will always remain in place.  asm's without inputs or outputs
 476    are implicitly volatile. */
 477 #ifdef __GNUC__
 478 #define SCM_FENCE asm /* volatile */ ("")
 479 #elif defined (__INTEL_COMPILER) && defined (__ia64)
 480 #define SCM_FENCE __memory_barrier()
 481 #else
 482 #define SCM_FENCE
 483 #endif
 484
 485 #define SCM_TICK \
 486 do { \
 487   SCM_ASYNC_TICK; \
 488   SCM_THREAD_SWITCHING_CODE; \
 489 } while (0)
 490
 491 \f
 492
 493 /** SCM_ASSERT
 494  **
 495  **/
 496
 497
 498 #ifdef SCM_RECKLESS
 499 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 500 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg)
 501 #define SCM_ASRTGO(_cond, _label)
 502 #else
 503 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 504         do { if (!(_cond)) \
 505           scm_wrong_type_arg (_subr, _pos, _arg); } while (0)
 506 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg) \
 507         do { if (!(_cond)) \
 508           scm_wrong_type_arg_msg(_subr, _pos, _arg, _msg);  } while (0)
 509 #define SCM_ASRTGO(_cond, _label) \
 510         do {  if (!(_cond)) \
 511           goto _label; } while (0)
 512 #endif
 513
 514 /*
 515  * SCM_WTA_DISPATCH
 516  */
 517
 518 /* Dirk:FIXME:: In all of the SCM_WTA_DISPATCH_* macros it is assumed that
 519  * 'gf' is zero if uninitialized.  It would be cleaner if some valid SCM value
 520  * like SCM_BOOL_F or SCM_UNDEFINED was chosen.
 521  */
 522
 523 SCM_API SCM scm_call_generic_0 (SCM gf);
 524
 525 #define SCM_WTA_DISPATCH_0(gf, subr)                            \
 526   return (SCM_UNPACK (gf)                                       \
 527           ? scm_call_generic_0 ((gf))                           \
 528           : (scm_error_num_args_subr ((subr)), SCM_UNSPECIFIED))
 529 #define SCM_GASSERT0(cond, gf, subr) \
 530   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (subr))
 531
 532 SCM_API SCM scm_call_generic_1 (SCM gf, SCM a1);
 533
 534 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr)                   \
 535   return (SCM_UNPACK (gf)                                       \
 536           ? scm_call_generic_1 ((gf), (a1))                     \
 537           : (scm_wrong_type_arg ((subr), (pos), (a1)), SCM_UNSPECIFIED))
 538 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 539   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 540
 541 SCM_API SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 542
 543 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr)                       \
 544   return (SCM_UNPACK (gf)                                               \
 545           ? scm_call_generic_2 ((gf), (a1), (a2))                       \
 546           : (scm_wrong_type_arg ((subr), (pos),                         \
 547                                  (pos) == SCM_ARG1 ? (a1) : (a2)),      \
 548              SCM_UNSPECIFIED))
 549 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 550   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 551
 552 SCM_API SCM scm_apply_generic (SCM gf, SCM args);
 553
 554 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr)                           \
 555   return (SCM_UNPACK (gf)                                                 \
 556           ? scm_apply_generic ((gf), (args))                              \
 557           : (scm_wrong_type_arg ((subr), (pos),                           \
 558                                  scm_list_ref ((args),                    \
 559                                                scm_from_int ((pos) - 1))), \
 560              SCM_UNSPECIFIED))
 561 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 562   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 563
 564 #ifndef SCM_MAGIC_SNARFER
 565 /* Let these macros pass through if
 566    we are snarfing;  thus we can tell the
 567    difference between the use of an actual
 568    number vs. the use of one of these macros --
 569    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 570    constructs must match the formal argument name,
 571    but using SCM_ARG* avoids the test */
 572
 573 #define SCM_ARGn                0
 574 #define SCM_ARG1                1
 575 #define SCM_ARG2                2
 576 #define SCM_ARG3                3
 577 #define SCM_ARG4                4
 578 #define SCM_ARG5                5
 579 #define SCM_ARG6                6
 580 #define SCM_ARG7                7
 581
 582 #endif /* SCM_MAGIC_SNARFER */
 583
 584 \f
 585
 586 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 587  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 588  * SCM if errors were encountered.  The return code can be explicitly
 589  * specified in a SCM program with (scm_quit <n>).
 590  */
 591
 592 #ifndef SCM_EXIT_SUCCESS
 593 #ifdef vms
 594 #define SCM_EXIT_SUCCESS 1
 595 #else
 596 #define SCM_EXIT_SUCCESS 0
 597 #endif /* def vms */
 598 #endif /* ndef SCM_EXIT_SUCCESS */
 599 #ifndef SCM_EXIT_FAILURE
 600 #ifdef vms
 601 #define SCM_EXIT_FAILURE 2
 602 #else
 603 #define SCM_EXIT_FAILURE 1
 604 #endif /* def vms */
 605 #endif /* ndef SCM_EXIT_FAILURE */
 606
 607 /* Define SCM_C_INLINE_KEYWORD so that it can be used as a replacement
 608    for the "inline" keyword, expanding to nothing when "inline" is not
 609    available.
 610 */
 611
 612 #ifdef SCM_C_INLINE
 613 #define SCM_C_INLINE_KEYWORD SCM_C_INLINE
 614 #else
 615 #define SCM_C_INLINE_KEYWORD
 616 #endif
 617
 618 #endif  /* SCM___SCM_H */
 619
 620 /*
 621   Local Variables:
 622   c-file-style: "gnu"
 623   End:
 624 */