libguile/__scm.h

   1 /* classes: h_files */
   2
   3 #ifndef __SCMH
   4 #define __SCMH
   5 /*      Copyright (C) 1995, 1996, 1998, 1999, 2000 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 /* {Supported Options}
  47  *
  48  * These may be defined or undefined.
  49  */
  50
  51 /* #define GUILE_DEBUG_FREELIST */
  52
  53 /* If the compile FLAG `SCM_CAUTIOUS' is #defined then the number of
  54  * arguments is always checked for application of closures.  If the
  55  * compile FLAG `SCM_RECKLESS' is #defined then they are not checked.
  56  * Otherwise, number of argument checks for closures are made only when
  57  * the function position (whose value is the closure) of a combination is
  58  * not an ILOC or GLOC.  When the function position of a combination is a
  59  * symbol it will be checked only the first time it is evaluated because
  60  * it will then be replaced with an ILOC or GLOC.
  61  */
  62 #undef SCM_RECKLESS
  63 #define SCM_CAUTIOUS
  64
  65 /* After looking up a local for the first time, rewrite the
  66  * code graph, caching its position.
  67  */
  68 #define MEMOIZE_LOCALS
  69
  70 /* All the number support there is.
  71  */
  72 #define BIGNUMS
  73
  74 /* GC should relinquish empty cons-pair arenas.
  75  */
  76 #define GC_FREE_SEGMENTS
  77
  78 /* Provide a scheme-accessible count-down timer that
  79  * generates a pseudo-interrupt.
  80  */
  81 #define TICKS
  82
  83
  84 /* Use engineering notation when converting numbers strings?
  85  */
  86 #undef ENGNOT
  87
  88 #undef SCM_CAREFUL_INTS
  89 \f
  90 /* {Unsupported Options}
  91  *
  92  * These must be defined as given here.
  93  */
  94
  95
  96 #define CCLO
  97
  98 /* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
  99    have horrible plans for their unification.  */
 100 #undef SICP
 101
 102 \f
 103
 104 /* Random options (not yet supported or in final form). */
 105
 106 #define STACK_CHECKING
 107 #undef NO_CEVAL_STACK_CHECKING
 108
 109 \f
 110 /* What did the configure script discover about the outside world?  */
 111 #include "libguile/scmconfig.h"
 112
 113 #ifdef HAVE_LONG_LONGS
 114
 115 /* Some auto-generated .h files contain unused prototypes
 116  * that need these typedefs.
 117  */
 118 typedef long long long_long;
 119 typedef unsigned long long ulong_long;
 120
 121 #endif /* HAVE_LONG_LONGS */
 122
 123 \f
 124
 125 /* Define
 126  *
 127  * SCM_CHAR_CODE_LIMIT          == UCHAR_MAX + 1
 128  * SCM_MOST_POSITIVE_FIXNUM     (LONG_MAX>>2)
 129  * SCM_MOST_NEGATIVE_FIXNUM     == SCM_SRS((long)LONG_MIN, 2)
 130  */
 131
 132 #ifdef HAVE_LIMITS_H
 133 # include <limits.h>
 134 # ifdef UCHAR_MAX
 135 #  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
 136 # else
 137 #  define SCM_CHAR_CODE_LIMIT 256L
 138 # endif /* def UCHAR_MAX */
 139 # define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
 140 # ifdef _UNICOS                 /* Stupid cray bug */
 141 #  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
 142 # else
 143 #  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
 144 # endif                         /* UNICOS */
 145 #else
 146 # define SCM_CHAR_CODE_LIMIT 256L
 147 # define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
 148 # if (0 != ~0)
 149 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
 150 # else
 151 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
 152 # endif /*  (0 != ~0) */
 153 #endif /* def HAVE_LIMITS_H */
 154 \f
 155
 156 #ifdef STDC_HEADERS
 157 # include <stdlib.h>
 158 # ifdef AMIGA
 159 #  include <stddef.h>
 160 # endif /* def AMIGA */
 161 # define scm_sizet size_t
 162 #else
 163 # ifdef _SIZE_T
 164 #  define scm_sizet size_t
 165 # else
 166 #  define scm_sizet unsigned int
 167 # endif /* def _SIZE_T */
 168 #endif /* def STDC_HEADERS */
 169
 170 \f
 171
 172 #include "libguile/tags.h"
 173
 174 \f
 175 #ifdef vms
 176 # ifndef CHEAP_CONTINUATIONS
 177    typedef int jmp_buf[17];
 178    extern int setjump(jmp_buf env);
 179    extern int longjump(jmp_buf env, int ret);
 180 #  define setjmp setjump
 181 #  define longjmp longjump
 182 # else
 183 #  include <setjmp.h>
 184 # endif
 185 #else                           /* ndef vms */
 186 # ifdef _CRAY1
 187     typedef int jmp_buf[112];
 188     extern int setjump(jmp_buf env);
 189     extern int longjump(jmp_buf env, int ret);
 190 #  define setjmp setjump
 191 #  define longjmp longjump
 192 # else                          /* ndef _CRAY1 */
 193 #  include <setjmp.h>
 194 # endif                         /* ndef _CRAY1 */
 195 #endif                          /* ndef vms */
 196
 197 /* James Clark came up with this neat one instruction fix for
 198  * continuations on the SPARC.  It flushes the register windows so
 199  * that all the state of the process is contained in the stack.
 200  */
 201
 202 #ifdef sparc
 203 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 204 #else
 205 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 206 #endif
 207
 208 /* If stack is not longword aligned then
 209  */
 210
 211 /* #define SHORT_ALIGN */
 212 #ifdef THINK_C
 213 # define SHORT_ALIGN
 214 #endif
 215 #ifdef MSDOS
 216 # define SHORT_ALIGN
 217 #endif
 218 #ifdef atarist
 219 # define SHORT_ALIGN
 220 #endif
 221
 222 #ifdef SHORT_ALIGN
 223 typedef short SCM_STACKITEM;
 224 #else
 225 typedef long SCM_STACKITEM;
 226 #endif
 227 \f
 228
 229 #ifndef USE_THREADS
 230 #define SCM_THREAD_DEFER
 231 #define SCM_THREAD_ALLOW
 232 #define SCM_THREAD_REDEFER
 233 #define SCM_THREAD_SWITCHING_CODE
 234 #endif
 235
 236 extern unsigned int scm_async_clock;
 237
 238 #define SCM_ASYNC_TICK \
 239 do { \
 240   if (0 == --scm_async_clock) \
 241     scm_async_click (); \
 242 } while(0)
 243
 244 #ifdef SCM_CAREFUL_INTS
 245 #define SCM_CHECK_NOT_DISABLED \
 246   if (scm_ints_disabled) \
 247     fputs("ints already disabled\n", stderr); \
 248
 249 #define SCM_CHECK_NOT_ENABLED \
 250   if (!scm_ints_disabled) \
 251     fputs("ints already enabled\n", stderr); \
 252
 253 #else
 254 #define SCM_CHECK_NOT_DISABLED
 255 #define SCM_CHECK_NOT_ENABLED
 256 #endif
 257
 258
 259 /* Anthony Green writes:
 260    When the compiler sees...
 261            DEFER_INTS;
 262            [critical code here]
 263            ALLOW_INTS;
 264    ...it doesn't actually promise to keep the critical code within the
 265    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 266    schedule it outside of the magic defined in those macros.
 267
 268    However, GCC's volatile asm feature forms a barrier over which code is
 269    never moved. So if you add...
 270            asm ("");
 271    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 272    code will always remain in place.  asm's without inputs or outputs
 273    are implicitly volatile. */
 274 #ifdef __GNUC__
 275 #define SCM_FENCE asm /* volatile */ ("")
 276 #else
 277 #define SCM_FENCE
 278 #endif
 279
 280 #define SCM_DEFER_INTS \
 281 do { \
 282   SCM_FENCE; \
 283   SCM_CHECK_NOT_DISABLED; \
 284   SCM_THREAD_DEFER; \
 285   SCM_FENCE; \
 286   scm_ints_disabled = 1; \
 287   SCM_FENCE; \
 288 } while (0)
 289
 290
 291 #define SCM_ALLOW_INTS_ONLY \
 292 do { \
 293   SCM_THREAD_ALLOW; \
 294   scm_ints_disabled = 0; \
 295 } while (0)
 296
 297
 298 #define SCM_ALLOW_INTS \
 299 do { \
 300   SCM_FENCE; \
 301   SCM_CHECK_NOT_ENABLED; \
 302   SCM_THREAD_SWITCHING_CODE; \
 303   SCM_FENCE; \
 304   scm_ints_disabled = 0; \
 305   SCM_FENCE; \
 306   SCM_THREAD_ALLOW; \
 307   SCM_FENCE; \
 308 } while (0)
 309
 310
 311 #define SCM_REDEFER_INTS  \
 312 do { \
 313   SCM_FENCE; \
 314   SCM_THREAD_REDEFER; \
 315   ++scm_ints_disabled; \
 316   SCM_FENCE; \
 317 } while (0)
 318
 319
 320 #define SCM_REALLOW_INTS \
 321 do { \
 322   SCM_FENCE; \
 323   SCM_THREAD_SWITCHING_CODE; \
 324   SCM_FENCE; \
 325   --scm_ints_disabled; \
 326   SCM_FENCE; \
 327 } while (0)
 328
 329
 330 #define SCM_TICK \
 331 do { \
 332   SCM_DEFER_INTS; \
 333   SCM_ALLOW_INTS; \
 334   SCM_ASYNC_TICK; \
 335 } while (0)
 336
 337 \f
 338
 339 /* Classification of critical sections
 340  *
 341  * When Guile moves to POSIX threads, it won't be possible to prevent
 342  * context switching.  In fact, the whole idea of context switching is
 343  * bogus if threads are run by different processors.  Therefore, we
 344  * must ultimately eliminate all critical sections or enforce them by
 345  * use of mutecis.
 346  *
 347  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 348  * be classified and replaced by one of the delimiters below.  If you
 349  * understand what this is all about, I'd like to encourage you to
 350  * help with this task.  The set of classes below must of course be
 351  * incrementally augmented.
 352  *
 353  * MDJ 980419 <djurfeldt@nada.kth.se>
 354  */
 355
 356 /* A sections
 357  *
 358  * Allocation of a cell with type tag in the CAR.
 359  *
 360  * With POSIX threads, each thread will have a private pool of free
 361  * cells.  Therefore, this type of section can be removed.  But!  It
 362  * is important that the CDR is initialized first (with the CAR still
 363  * indicating a free cell) so that we can guarantee a consistent heap
 364  * at all times.
 365  */
 366
 367 #ifdef SCM_POSIX_THREADS
 368 #define SCM_ENTER_A_SECTION
 369 #define SCM_EXIT_A_SECTION
 370 #else
 371 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 372 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 373 #endif
 374
 375 \f
 376
 377 /** SCM_ASSERT
 378  **
 379  **/
 380
 381
 382 #ifdef SCM_RECKLESS
 383 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 384 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr)
 385 #define SCM_ASRTGO(_cond, _label)
 386 #else
 387 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 388         if (!(_cond)) \
 389           scm_wta(_arg, (char *)(_pos), _subr)
 390 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg) \
 391         if (!(_cond)) \
 392           scm_wrong_type_arg_msg(_subr, _pos, _arg, _msg)
 393 #define SCM_ASRTGO(_cond, _label) \
 394         if (!(_cond)) \
 395           goto _label
 396 #endif
 397
 398 /*
 399  * SCM_WTA_DISPATCH
 400  */
 401
 402 extern SCM scm_call_generic_0 (SCM gf);
 403
 404 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 405   return ((gf) \
 406           ? scm_call_generic_0 ((gf)) \
 407           : scm_wta ((arg), (char *) (pos), (subr)))
 408 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 409   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (arg), (pos), (subr))
 410
 411 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 412
 413 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 414   return ((gf) \
 415           ? scm_call_generic_1 ((gf), (a1)) \
 416           : scm_wta ((a1), (char *) (pos), (subr)))
 417 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 418   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 419
 420 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 421
 422 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 423   return ((gf) \
 424           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 425           : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
 426 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 427   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 428
 429 extern SCM scm_apply_generic (SCM gf, SCM args);
 430
 431 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 432   return ((gf) \
 433           ? scm_apply_generic ((gf), (args)) \
 434           : scm_wta (scm_list_ref ((args), SCM_MAKINUM ((pos) - 1)), \
 435                      (char *) (pos), \
 436                      (subr)))
 437 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 438   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 439
 440 #ifndef SCM_MAGIC_SNARFER
 441 /* Let these macros pass through if
 442    we are snarfing;  thus we can tell the
 443    difference between the use of an actual
 444    number vs. the use of one of these macros --
 445    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 446    constructs must match the formal argument name,
 447    but using SCM_ARG* avoids the test */
 448
 449 #define SCM_ARGn                0
 450 #define SCM_ARG1                1
 451 #define SCM_ARG2                2
 452 #define SCM_ARG3                3
 453 #define SCM_ARG4                4
 454 #define SCM_ARG5                5
 455 #define SCM_ARG6                6
 456 #define SCM_ARG7                7
 457      /* #define SCM_ARGERR(X)           ((X) < SCM_WNA \
 458                                  ? (char *)(X) \
 459                                  : "wrong type argument")
 460                                  */
 461
 462 /* Following must match entry indexes in scm_errmsgs[].
 463  * Also, SCM_WNA must follow the last SCM_ARGn in sequence.
 464  */
 465 #define SCM_WNA                 8
 466      /* #define SCM_OVSCM_FLOW          9 */
 467 #define SCM_OUTOFRANGE          10
 468 #define SCM_NALLOC              11
 469      /* #define SCM_STACK_OVFLOW        12 */
 470      /* #define SCM_EXIT                13 */
 471
 472 #endif /* SCM_MAGIC_SNARFER */
 473
 474 /* (...still matching scm_errmsgs)  These
 475  * are signals.  Signals may become errors
 476  * but are distinguished because they first
 477  * try to invoke a handler that can resume
 478  * the interrupted routine.
 479  */
 480 #define SCM_HUP_SIGNAL          14
 481 #define SCM_INT_SIGNAL          15
 482 #define SCM_FPE_SIGNAL          16
 483 #define SCM_BUS_SIGNAL          17
 484 #define SCM_SEGV_SIGNAL         18
 485 #define SCM_ALRM_SIGNAL         19
 486 #define SCM_GC_SIGNAL           20
 487 #define SCM_TICK_SIGNAL         21
 488
 489 #define SCM_SIG_ORD(X)          ((X) - SCM_HUP_SIGNAL)
 490 #define SCM_ORD_SIG(X)          ((X) + SCM_HUP_SIGNAL)
 491 #define SCM_NUM_SIGS            (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 492
 493 #if 0
 494 struct errdesc
 495 {
 496   char *msg;
 497   char *s_response;
 498   short parent_err;
 499 };
 500
 501
 502 extern struct errdesc scm_errmsgs[];
 503 #endif
 504
 505 \f
 506
 507 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 508  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 509  * SCM if errors were encountered.  The return code can be explicitly
 510  * specified in a SCM program with (scm_quit <n>).
 511  */
 512
 513 #ifndef SCM_EXIT_SUCCESS
 514 #ifdef vms
 515 #define SCM_EXIT_SUCCESS 1
 516 #else
 517 #define SCM_EXIT_SUCCESS 0
 518 #endif /* def vms */
 519 #endif /* ndef SCM_EXIT_SUCCESS */
 520 #ifndef SCM_EXIT_FAILURE
 521 #ifdef vms
 522 #define SCM_EXIT_FAILURE 2
 523 #else
 524 #define SCM_EXIT_FAILURE 1
 525 #endif /* def vms */
 526 #endif /* ndef SCM_EXIT_FAILURE */
 527
 528
 529
 530 \f
 531
 532 #endif  /* __SCMH */