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, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; either version 3 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  21  * 02110-1301 USA
  22  */
  23
  24 \f
  25
  26 /**********************************************************************
  27  This file is Guile's central public header.
  28
  29  When included by other files, this file should preceed any include
  30  other than __scm.h.
  31
  32  Under *NO* circumstances should new items be added to the global
  33  namespace (via adding #define, typedef, or similar to this file) with
  34  generic names.  This usually means that any new names should be
  35  prefixed by either SCM_ or GUILE_.  i.e. do *not* #define HAVE_FOO or
  36  SIZEOF_BAR.  See configure.in, gen-scmconfig.h.in, and
  37  gen-scmconfig.c for examples of how to properly handle this issue.
  38  The main documentation is in gen-scmconfig.c.
  39
  40  "What's the difference between _scm.h and __scm.h?"
  41
  42    _scm.h is not installed; it's only visible to the libguile sources
  43    themselves, and it includes config.h, the private config header.
  44
  45    __scm.h is installed, and is #included by <libguile.h>.  If both
  46    the client and libguile need some piece of information, and it
  47    doesn't fit well into the header file for any particular module, it
  48    should go in __scm.h.  __scm.h includes scmconfig.h, the public
  49    config header.
  50  **********************************************************************/
  51
  52 /* What did the configure script discover about the outside world?  */
  53 #include "libguile/scmconfig.h"
  54
  55 \f
  56
  57 /* {Compiler hints}
  58  *
  59  * The following macros are used to provide additional information for the
  60  * compiler, which may help to do better error checking and code
  61  * optimization.  A second benefit of these macros is, that they also provide
  62  * additional information to the developers.
  63  */
  64
  65 /* The macro SCM_NORETURN indicates that a function will never return.
  66  * Examples:
  67  *   1) int foo (char arg) SCM_NORETURN;
  68  */
  69 #ifdef __GNUC__
  70 #define SCM_NORETURN __attribute__ ((noreturn))
  71 #else
  72 #define SCM_NORETURN
  73 #endif
  74
  75 /* The macro SCM_UNUSED indicates that a function, function argument or
  76  * variable may potentially be unused.
  77  * Examples:
  78  *   1) static int unused_function (char arg) SCM_UNUSED;
  79  *   2) int foo (char unused_argument SCM_UNUSED);
  80  *   3) int unused_variable SCM_UNUSED;
  81  */
  82 #ifdef __GNUC__
  83 #define SCM_UNUSED __attribute__ ((unused))
  84 #else
  85 #define SCM_UNUSED
  86 #endif
  87
  88
  89 /* The SCM_EXPECT macros provide branch prediction hints to the compiler.  To
  90  * use only in places where the result of the expression under "normal"
  91  * circumstances is known.  */
  92 #if defined(__GNUC__) && (__GNUC__ >= 3)
  93 # define SCM_EXPECT    __builtin_expect
  94 #else
  95 # define SCM_EXPECT(_expr, _value) (_expr)
  96 #endif
  97
  98 #define SCM_LIKELY(_expr)    SCM_EXPECT ((_expr), 1)
  99 #define SCM_UNLIKELY(_expr)  SCM_EXPECT ((_expr), 0)
 100
 101 /* The SCM_INTERNAL macro makes it possible to explicitly declare a function
 102  * as having "internal" linkage.  However our current tack on this problem is
 103  * to use GCC 4's -fvisibility=hidden, making functions internal by default,
 104  * and then SCM_API marks them for export. */
 105 #define SCM_INTERNAL  extern
 106
 107
 108 \f
 109 /* {Supported Options}
 110  *
 111  * These may be defined or undefined.
 112  */
 113
 114 /* #define GUILE_DEBUG_FREELIST */
 115
 116 /* All the number support there is.
 117  */
 118 #define BIGNUMS
 119
 120 /* GC should relinquish empty cons-pair arenas. */
 121 /* cmm:FIXME look at this after done mangling the GC */
 122 /* #define GC_FREE_SEGMENTS */
 123
 124 /* Provide a scheme-accessible count-down timer that
 125  * generates a pseudo-interrupt.
 126  */
 127 #define TICKS
 128
 129
 130 /* Use engineering notation when converting numbers strings?
 131  */
 132 #undef ENGNOT
 133
 134 \f
 135 /* {Unsupported Options}
 136  *
 137  * These must be defined as given here.
 138  */
 139
 140
 141 /* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
 142    have horrible plans for their unification.  */
 143 #undef SICP
 144
 145 \f
 146
 147 /* Random options (not yet supported or in final form). */
 148
 149 #define STACK_CHECKING
 150 #undef NO_CEVAL_STACK_CHECKING
 151
 152 \f
 153
 154 /* SCM_API is a macro prepended to all function and data definitions
 155    which should be exported from libguile. */
 156
 157 #if BUILDING_LIBGUILE && HAVE_VISIBILITY
 158 # define SCM_API extern __attribute__((__visibility__("default")))
 159 #elif BUILDING_LIBGUILE && defined _MSC_VER
 160 # define SCM_API __declspec(dllexport) extern
 161 #elif defined _MSC_VER
 162 # define SCM_API __declspec(dllimport) extern
 163 #else
 164 # define SCM_API extern
 165 #endif
 166
 167 \f
 168
 169 /* {Debugging Options}
 170  *
 171  * These compile time options determine whether to include code that is only
 172  * useful for debugging guile itself or C level extensions to guile.  The
 173  * common prefix for all option macros of this kind is "SCM_DEBUG_".  It is
 174  * guaranteed that a macro named SCM_DEBUG_XXX is always defined (typically to
 175  * either 0 or 1), i. e. there is no need to test for the undefined case.
 176  * This allows to use these definitions comfortably within code, as in the
 177  * following example:
 178  *   #define FOO do { if (SCM_DEBUG_XXX) bar(); else baz(); } while (0)
 179  * Any sane compiler will remove the unused branch without any performance
 180  * penalty for the resulting code.
 181  *
 182  * Note:  Some SCM_DEBUG_XXX options are not settable at configure time.
 183  * To change the value of such options you will have to edit this header
 184  * file or give suitable options to make, like:
 185  *   make all CFLAGS="-DSCM_DEBUG_XXX=1 ..."
 186  */
 187
 188
 189 /* The value of SCM_DEBUG determines the default for most of the not yet
 190  * defined debugging options.  This allows, for example, to enable most of the
 191  * debugging options by simply defining SCM_DEBUG as 1.
 192  */
 193 #ifndef SCM_DEBUG
 194 #define SCM_DEBUG 0
 195 #endif
 196
 197 /* For debugging purposes: define this is to ensure nobody is using
 198  * the mark bits outside of the marking phase.  This is meant for
 199  * debugging purposes only.
 200  */
 201 #ifndef SCM_DEBUG_MARKING_API
 202 #define SCM_DEBUG_MARKING_API 0
 203 #endif
 204
 205 /* If SCM_DEBUG_CELL_ACCESSES is set to 1, cell accesses will perform
 206  * exhaustive parameter checking:  It will be verified that cell parameters
 207  * actually point to a valid heap cell.  Note:  If this option is enabled,
 208  * guile will run about ten times slower than normally.
 209  */
 210 #ifndef SCM_DEBUG_CELL_ACCESSES
 211 #define SCM_DEBUG_CELL_ACCESSES SCM_DEBUG
 212 #endif
 213
 214 /* If SCM_DEBUG_INTERRUPTS is set to 1, with every deferring and allowing of
 215  * interrupts a consistency check will be performed.
 216  */
 217 #ifndef SCM_DEBUG_INTERRUPTS
 218 #define SCM_DEBUG_INTERRUPTS SCM_DEBUG
 219 #endif
 220
 221 /* If SCM_DEBUG_PAIR_ACCESSES is set to 1, accesses to cons cells will be
 222  * exhaustively checked.  Note:  If this option is enabled, guile will run
 223  * slower than normally.
 224  */
 225 #ifndef SCM_DEBUG_PAIR_ACCESSES
 226 #define SCM_DEBUG_PAIR_ACCESSES SCM_DEBUG
 227 #endif
 228
 229 /* If SCM_DEBUG_REST_ARGUMENT is set to 1, functions that take rest arguments
 230  * will check whether the rest arguments are actually passed as a proper list.
 231  * Otherwise, if SCM_DEBUG_REST_ARGUMENT is 0, functions that take rest
 232  * arguments will take it for granted that these are passed as a proper list.
 233  */
 234 #ifndef SCM_DEBUG_REST_ARGUMENT
 235 #define SCM_DEBUG_REST_ARGUMENT SCM_DEBUG
 236 #endif
 237
 238 /* The macro SCM_DEBUG_TYPING_STRICTNESS indicates what level of type checking
 239  * shall be performed with respect to the use of the SCM datatype.  The macro
 240  * may be defined to one of the values 0, 1 and 2.
 241  *
 242  * A value of 0 means that there will be no compile time type checking, since
 243  * the SCM datatype will be declared as an integral type.  This setting should
 244  * only be used on systems, where casting from integral types to pointers may
 245  * lead to loss of bit information.
 246  *
 247  * A value of 1 means that there will an intermediate level of compile time
 248  * type checking, since the SCM datatype will be declared as a pointer to an
 249  * undefined struct.  This setting is the default, since it does not cost
 250  * anything in terms of performance or code size.
 251  *
 252  * A value of 2 provides a maximum level of compile time type checking since
 253  * the SCM datatype will be declared as a struct.  This setting should be used
 254  * for _compile time_ type checking only, since the compiled result is likely
 255  * to be quite inefficient.  The right way to make use of this option is to do
 256  * a 'make clean; make CFLAGS=-DSCM_DEBUG_TYPING_STRICTNESS=2', fix your
 257  * errors, and then do 'make clean; make'.
 258  */
 259 #ifndef SCM_DEBUG_TYPING_STRICTNESS
 260 #define SCM_DEBUG_TYPING_STRICTNESS 1
 261 #endif
 262
 263 /* If SCM_DEBUG_DEBUGGING_SUPPORT is set to 1, guile will provide a set of
 264  * special functions that support debugging with a debugger like gdb or
 265  * debugging of guile internals on the scheme level.  The behaviour of guile
 266  * is not changed by this macro, only the set of functions that are available
 267  * will differ.  All functions that are introduced this way have the prefix
 268  * 'scm_dbg_' on the C level and the prefix 'dbg-' on the scheme level.  This
 269  * allows to easily determine the set of support functions, given that your
 270  * debugger or repl provide automatic name completion.  Note that these
 271  * functions are intended to be used during interactive debugging sessions
 272  * only.  They are not considered part of guile's official API.  They may
 273  * change or disappear without notice or deprecation phase.
 274  */
 275 #ifndef SCM_DEBUG_DEBUGGING_SUPPORT
 276 #define SCM_DEBUG_DEBUGGING_SUPPORT SCM_DEBUG
 277 #endif
 278
 279 \f
 280
 281 /* {Feature Options}
 282  *
 283  * These compile time options determine whether code for certain features
 284  * should be compiled into guile.  The common prefix for all option macros
 285  * of this kind is "SCM_ENABLE_".  It is guaranteed that a macro named
 286  * SCM_ENABLE_XXX is defined to be either 0 or 1, i. e. there is no need to
 287  * test for the undefined case.  This allows to use these definitions
 288  * comfortably within code, as in the following example:
 289  *   #define FOO do { if (SCM_ENABLE_XXX) bar(); else baz(); } while (0)
 290  * Any sane compiler will remove the unused branch without any performance
 291  * penalty for the resulting code.
 292  *
 293  * Note:  Some SCM_ENABLE_XXX options are not settable at configure time.
 294  * To change the value of such options you will have to edit this header
 295  * file or give suitable options to make, like:
 296  *   make all CFLAGS="-DSCM_ENABLE_XXX=1 ..."
 297  */
 298
 299 /* If SCM_ENABLE_DEPRECATED is set to 1, deprecated code will be included in
 300  * guile, as well as some functions to issue run-time warnings about uses of
 301  * deprecated functions.
 302  */
 303 #ifndef SCM_ENABLE_DEPRECATED
 304 #define SCM_ENABLE_DEPRECATED 0
 305 #endif
 306
 307 \f
 308
 309 /* {Architecture and compiler properties}
 310  *
 311  * Guile as of today can only work on systems which fulfill at least the
 312  * following requirements:
 313  *
 314  * - scm_t_bits and SCM variables have at least 32 bits.
 315  *   Guile's type system is based on this assumption.
 316  *
 317  * - sizeof (scm_t_bits) >= sizeof (void*) and sizeof (SCM) >= sizeof (void*)
 318  *   Guile's type system is based on this assumption, since it must be
 319  *   possible to store pointers to cells on the heap in scm_t_bits and SCM
 320  *   variables.
 321  *
 322  * - sizeof (scm_t_bits) >= 4 and sizeof (scm_t_bits) is a power of 2.
 323  *   Guile's type system is based on this assumption.  In particular, it is
 324  *   assumed that cells, i. e. pairs of scm_t_bits variables, are eight
 325  *   character aligned.  This is because three bits of a scm_t_bits variable
 326  *   that is holding a pointer to a cell on the heap must be available for
 327  *   storing type data.
 328  *
 329  * - sizeof (scm_t_bits) <= sizeof (void*) and sizeof (SCM) <= sizeof (void*)
 330  *   In some parts of guile, scm_t_bits and SCM variables are passed to
 331  *   functions as void* arguments.  Together with the requirement above, this
 332  *   requires a one-to-one correspondence between the size of a void* and the
 333  *   sizes of scm_t_bits and SCM variables.
 334  *
 335  * - numbers are encoded using two's complement.
 336  *   The implementation of the bitwise scheme level operations is based on
 337  *   this assumption.
 338  *
 339  * - ... add more
 340  */
 341
 342 #ifdef CHAR_BIT
 343 # define SCM_CHAR_BIT CHAR_BIT
 344 #else
 345 # define SCM_CHAR_BIT 8
 346 #endif
 347
 348 #ifdef LONG_BIT
 349 # define SCM_LONG_BIT LONG_BIT
 350 #else
 351 # define SCM_LONG_BIT (SCM_CHAR_BIT * sizeof (long) / sizeof (char))
 352 #endif
 353
 354 #ifdef UCHAR_MAX
 355 # define SCM_CHAR_CODE_LIMIT (UCHAR_MAX + 1L)
 356 #else
 357 # define SCM_CHAR_CODE_LIMIT 256L
 358 #endif
 359
 360 #define SCM_I_UTYPE_MAX(type)      ((type)-1)
 361 #define SCM_I_TYPE_MAX(type,umax)  ((type)((umax)/2))
 362 #define SCM_I_TYPE_MIN(type,umax)  (-((type)((umax)/2))-1)
 363
 364 #define SCM_T_UINT8_MAX   SCM_I_UTYPE_MAX(scm_t_uint8)
 365 #define SCM_T_INT8_MIN    SCM_I_TYPE_MIN(scm_t_int8,SCM_T_UINT8_MAX)
 366 #define SCM_T_INT8_MAX    SCM_I_TYPE_MAX(scm_t_int8,SCM_T_UINT8_MAX)
 367
 368 #define SCM_T_UINT16_MAX  SCM_I_UTYPE_MAX(scm_t_uint16)
 369 #define SCM_T_INT16_MIN   SCM_I_TYPE_MIN(scm_t_int16,SCM_T_UINT16_MAX)
 370 #define SCM_T_INT16_MAX   SCM_I_TYPE_MAX(scm_t_int16,SCM_T_UINT16_MAX)
 371
 372 #define SCM_T_UINT32_MAX  SCM_I_UTYPE_MAX(scm_t_uint32)
 373 #define SCM_T_INT32_MIN   SCM_I_TYPE_MIN(scm_t_int32,SCM_T_UINT32_MAX)
 374 #define SCM_T_INT32_MAX   SCM_I_TYPE_MAX(scm_t_int32,SCM_T_UINT32_MAX)
 375
 376 #if SCM_HAVE_T_INT64
 377 #define SCM_T_UINT64_MAX  SCM_I_UTYPE_MAX(scm_t_uint64)
 378 #define SCM_T_INT64_MIN   SCM_I_TYPE_MIN(scm_t_int64,SCM_T_UINT64_MAX)
 379 #define SCM_T_INT64_MAX   SCM_I_TYPE_MAX(scm_t_int64,SCM_T_UINT64_MAX)
 380 #endif
 381
 382 #if SCM_SIZEOF_LONG_LONG
 383 #define SCM_I_ULLONG_MAX  SCM_I_UTYPE_MAX(unsigned long long)
 384 #define SCM_I_LLONG_MIN   SCM_I_TYPE_MIN(long long,SCM_I_ULLONG_MAX)
 385 #define SCM_I_LLONG_MAX   SCM_I_TYPE_MAX(long long,SCM_I_ULLONG_MAX)
 386 #endif
 387
 388 #define SCM_T_UINTMAX_MAX SCM_I_UTYPE_MAX(scm_t_uintmax)
 389 #define SCM_T_INTMAX_MIN  SCM_I_TYPE_MIN(scm_t_intmax,SCM_T_UINTMAX_MAX)
 390 #define SCM_T_INTMAX_MAX  SCM_I_TYPE_MAX(scm_t_intmax,SCM_T_UINTMAX_MAX)
 391
 392 #define SCM_I_SIZE_MAX    SCM_I_UTYPE_MAX(size_t)
 393 #define SCM_I_SSIZE_MIN   SCM_I_TYPE_MIN(ssize_t,SCM_I_SIZE_MAX)
 394 #define SCM_I_SSIZE_MAX   SCM_I_TYPE_MAX(ssize_t,SCM_I_SIZE_MAX)
 395
 396 \f
 397
 398 #include "libguile/tags.h"
 399
 400 \f
 401 #ifdef vms
 402 # ifndef CHEAP_CONTINUATIONS
 403    typedef int jmp_buf[17];
 404    extern int setjump(jmp_buf env);
 405    extern int longjump(jmp_buf env, int ret);
 406 #  define setjmp setjump
 407 #  define longjmp longjump
 408 # else
 409 #  include <setjmp.h>
 410 # endif
 411 #else                           /* ndef vms */
 412 # ifdef _CRAY1
 413     typedef int jmp_buf[112];
 414     extern int setjump(jmp_buf env);
 415     extern int longjump(jmp_buf env, int ret);
 416 #  define setjmp setjump
 417 #  define longjmp longjump
 418 # else                          /* ndef _CRAY1 */
 419 #  if defined (__ia64__)
 420 /* For IA64, emulate the setjmp API using getcontext. */
 421 #   include <signal.h>
 422 #   include <ucontext.h>
 423     typedef struct {
 424       ucontext_t ctx;
 425       int fresh;
 426     } scm_i_jmp_buf;
 427 #   define SCM_I_SETJMP(JB)                             \
 428       ( (JB).fresh = 1,                                 \
 429         getcontext (&((JB).ctx)),                       \
 430         ((JB).fresh ? ((JB).fresh = 0, 0) : 1) )
 431 #   define SCM_I_LONGJMP(JB,VAL) scm_ia64_longjmp (&(JB), VAL)
 432     void scm_ia64_longjmp (scm_i_jmp_buf *, int);
 433 #  else                         /* ndef __ia64__ */
 434 #   include <setjmp.h>
 435 #  endif                        /* ndef __ia64__ */
 436 # endif                         /* ndef _CRAY1 */
 437 #endif                          /* ndef vms */
 438
 439 /* For any platform where SCM_I_SETJMP hasn't been defined in some
 440    special way above, map SCM_I_SETJMP, SCM_I_LONGJMP and
 441    scm_i_jmp_buf to setjmp, longjmp and jmp_buf. */
 442 #ifndef SCM_I_SETJMP
 443 #define scm_i_jmp_buf jmp_buf
 444 #define SCM_I_SETJMP setjmp
 445 #define SCM_I_LONGJMP longjmp
 446 #endif
 447
 448 /* James Clark came up with this neat one instruction fix for
 449  * continuations on the SPARC.  It flushes the register windows so
 450  * that all the state of the process is contained in the stack.
 451  */
 452
 453 #if defined (sparc) || defined (__sparc__) || defined (__sparc)
 454 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 455 #else
 456 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 457 #endif
 458
 459 /* If stack is not longword aligned then
 460  */
 461
 462 /* #define SHORT_ALIGN */
 463 #ifdef THINK_C
 464 # define SHORT_ALIGN
 465 #endif
 466 #ifdef MSDOS
 467 # define SHORT_ALIGN
 468 #endif
 469 #ifdef atarist
 470 # define SHORT_ALIGN
 471 #endif
 472
 473 #ifdef SHORT_ALIGN
 474 typedef short SCM_STACKITEM;
 475 #else
 476 typedef long SCM_STACKITEM;
 477 #endif
 478
 479 /* Cast pointer through (void *) in order to avoid compiler warnings
 480    when strict aliasing is enabled */
 481 #define SCM_STACK_PTR(ptr) ((SCM_STACKITEM *) (void *) (ptr))
 482 \f
 483
 484 #define SCM_ASYNC_TICK /*fixme* should change names */ \
 485 do { \
 486   if (SCM_I_CURRENT_THREAD->pending_asyncs) \
 487     scm_async_click (); \
 488 } while (0)
 489
 490
 491 /* Anthony Green writes:
 492    When the compiler sees...
 493            DEFER_INTS;
 494            [critical code here]
 495            ALLOW_INTS;
 496    ...it doesn't actually promise to keep the critical code within the
 497    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 498    schedule it outside of the magic defined in those macros.
 499
 500    However, GCC's volatile asm feature forms a barrier over which code is
 501    never moved. So if you add...
 502            asm ("");
 503    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 504    code will always remain in place.  asm's without inputs or outputs
 505    are implicitly volatile. */
 506 #ifdef __GNUC__
 507 #define SCM_FENCE asm /* volatile */ ("")
 508 #elif defined (__INTEL_COMPILER) && defined (__ia64)
 509 #define SCM_FENCE __memory_barrier()
 510 #else
 511 #define SCM_FENCE
 512 #endif
 513
 514 #define SCM_TICK \
 515 do { \
 516   SCM_ASYNC_TICK; \
 517   SCM_THREAD_SWITCHING_CODE; \
 518 } while (0)
 519
 520 \f
 521
 522 /** SCM_ASSERT
 523  **
 524  **/
 525
 526
 527 #ifdef SCM_RECKLESS
 528 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 529 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg)
 530 #define SCM_ASRTGO(_cond, _label)
 531 #else
 532 #define SCM_ASSERT(_cond, _arg, _pos, _subr)                    \
 533         do { if (SCM_UNLIKELY (!(_cond)))                       \
 534           scm_wrong_type_arg (_subr, _pos, _arg); } while (0)
 535 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg)                 \
 536         do { if (SCM_UNLIKELY (!(_cond)))                               \
 537           scm_wrong_type_arg_msg(_subr, _pos, _arg, _msg);  } while (0)
 538 #define SCM_ASRTGO(_cond, _label)               \
 539         do {  if (SCM_UNLIKELY (!(_cond)))      \
 540           goto _label; } while (0)
 541 #endif
 542
 543 /*
 544  * SCM_WTA_DISPATCH
 545  */
 546
 547 /* Dirk:FIXME:: In all of the SCM_WTA_DISPATCH_* macros it is assumed that
 548  * 'gf' is zero if uninitialized.  It would be cleaner if some valid SCM value
 549  * like SCM_BOOL_F or SCM_UNDEFINED was chosen.
 550  */
 551
 552 SCM_API SCM scm_call_generic_0 (SCM gf);
 553
 554 #define SCM_WTA_DISPATCH_0(gf, subr)                            \
 555   return (SCM_UNPACK (gf)                                       \
 556           ? scm_call_generic_0 ((gf))                           \
 557           : (scm_error_num_args_subr ((subr)), SCM_UNSPECIFIED))
 558 #define SCM_GASSERT0(cond, gf, subr)            \
 559   if (SCM_UNLIKELY(!(cond)))            \
 560     SCM_WTA_DISPATCH_0((gf), (subr))
 561
 562 SCM_API SCM scm_call_generic_1 (SCM gf, SCM a1);
 563
 564 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr)                   \
 565   return (SCM_UNPACK (gf)                                       \
 566           ? scm_call_generic_1 ((gf), (a1))                     \
 567           : (scm_wrong_type_arg ((subr), (pos), (a1)), SCM_UNSPECIFIED))
 568
 569 /* This form is for dispatching a subroutine.  */
 570 #define SCM_WTA_DISPATCH_1_SUBR(subr, a1, pos)                          \
 571   return (SCM_UNPACK ((*SCM_SUBR_GENERIC (subr)))                       \
 572           ? scm_call_generic_1 ((*SCM_SUBR_GENERIC (subr)), (a1))       \
 573           : (scm_i_wrong_type_arg_symbol (SCM_SUBR_NAME (subr), (pos), (a1)), SCM_UNSPECIFIED))
 574
 575 #define SCM_GASSERT1(cond, gf, a1, pos, subr)           \
 576   if (SCM_UNLIKELY (!(cond)))                   \
 577     SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 578
 579 SCM_API SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 580
 581 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr)                       \
 582   return (SCM_UNPACK (gf)                                               \
 583           ? scm_call_generic_2 ((gf), (a1), (a2))                       \
 584           : (scm_wrong_type_arg ((subr), (pos),                         \
 585                                  (pos) == SCM_ARG1 ? (a1) : (a2)),      \
 586              SCM_UNSPECIFIED))
 587 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr)       \
 588   if (SCM_UNLIKELY (!(cond)))                   \
 589     SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 590
 591 SCM_API SCM scm_apply_generic (SCM gf, SCM args);
 592
 593 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr)                           \
 594   return (SCM_UNPACK (gf)                                                 \
 595           ? scm_apply_generic ((gf), (args))                              \
 596           : (scm_wrong_type_arg ((subr), (pos),                           \
 597                                  scm_list_ref ((args),                    \
 598                                                scm_from_int ((pos) - 1))), \
 599              SCM_UNSPECIFIED))
 600 #define SCM_GASSERTn(cond, gf, args, pos, subr)         \
 601   if (SCM_UNLIKELY (!(cond)))                   \
 602     SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 603
 604 #ifndef SCM_MAGIC_SNARFER
 605 /* Let these macros pass through if
 606    we are snarfing;  thus we can tell the
 607    difference between the use of an actual
 608    number vs. the use of one of these macros --
 609    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 610    constructs must match the formal argument name,
 611    but using SCM_ARG* avoids the test */
 612
 613 #define SCM_ARGn                0
 614 #define SCM_ARG1                1
 615 #define SCM_ARG2                2
 616 #define SCM_ARG3                3
 617 #define SCM_ARG4                4
 618 #define SCM_ARG5                5
 619 #define SCM_ARG6                6
 620 #define SCM_ARG7                7
 621
 622 #endif /* SCM_MAGIC_SNARFER */
 623
 624 \f
 625
 626 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 627  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 628  * SCM if errors were encountered.  The return code can be explicitly
 629  * specified in a SCM program with (scm_quit <n>).
 630  */
 631
 632 #ifndef SCM_EXIT_SUCCESS
 633 #ifdef vms
 634 #define SCM_EXIT_SUCCESS 1
 635 #else
 636 #define SCM_EXIT_SUCCESS 0
 637 #endif /* def vms */
 638 #endif /* ndef SCM_EXIT_SUCCESS */
 639 #ifndef SCM_EXIT_FAILURE
 640 #ifdef vms
 641 #define SCM_EXIT_FAILURE 2
 642 #else
 643 #define SCM_EXIT_FAILURE 1
 644 #endif /* def vms */
 645 #endif /* ndef SCM_EXIT_FAILURE */
 646
 647 /* Define SCM_C_INLINE_KEYWORD so that it can be used as a replacement
 648    for the "inline" keyword, expanding to nothing when "inline" is not
 649    available.
 650 */
 651
 652 #ifdef SCM_C_INLINE
 653 #define SCM_C_INLINE_KEYWORD SCM_C_INLINE
 654 #else
 655 #define SCM_C_INLINE_KEYWORD
 656 #endif
 657
 658 #endif  /* SCM___SCM_H */
 659
 660 /*
 661   Local Variables:
 662   c-file-style: "gnu"
 663   End:
 664 */