libguile/__scm.h

   1 /* classes: h_files */
   2
   3 #ifndef __SCMH
   4 #define __SCMH
   5 /*      Copyright (C) 1995, 1996, 1998, 1999 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 SCM_FLOATS
  73 #define BIGNUMS
  74
  75 /* GC should relinquish empty cons-pair arenas.
  76  */
  77 #define GC_FREE_SEGMENTS
  78
  79 /* Provide a scheme-accessible count-down timer that
  80  * generates a pseudo-interrupt.
  81  */
  82 #define TICKS
  83
  84
  85 /* Use engineering notation when converting numbers strings?
  86  */
  87 #undef ENGNOT
  88
  89 #undef SCM_CAREFUL_INTS
  90 \f
  91 /* {Unsupported Options}
  92  *
  93  * These must be defined as given here.
  94  */
  95
  96
  97 #define CCLO
  98
  99 /* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
 100    have horrible plans for their unification.  */
 101 #undef SICP
 102
 103 \f
 104
 105 /* Random options (not yet supported or in final form). */
 106
 107 #define STACK_CHECKING
 108 #undef NO_CEVAL_STACK_CHECKING
 109
 110 \f
 111 /* What did the configure script discover about the outside world?  */
 112 #include "libguile/scmconfig.h"
 113
 114 #ifdef HAVE_LONG_LONGS
 115
 116 /* Some auto-generated .h files contain unused prototypes
 117  * that need these typedefs.
 118  */
 119 typedef long long long_long;
 120 typedef unsigned long long ulong_long;
 121
 122 #endif /* HAVE_LONG_LONGS */
 123
 124 \f
 125
 126 /* Define
 127  *
 128  * SCM_CHAR_CODE_LIMIT          == UCHAR_MAX + 1
 129  * SCM_MOST_POSITIVE_FIXNUM     (LONG_MAX>>2)
 130  * SCM_MOST_NEGATIVE_FIXNUM     == SCM_SRS((long)LONG_MIN, 2)
 131  */
 132
 133 #ifdef HAVE_LIMITS_H
 134 # include <limits.h>
 135 # ifdef UCHAR_MAX
 136 #  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
 137 # else
 138 #  define SCM_CHAR_CODE_LIMIT 256L
 139 # endif /* def UCHAR_MAX */
 140 # define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
 141 # ifdef _UNICOS                 /* Stupid cray bug */
 142 #  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
 143 # else
 144 #  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
 145 # endif                         /* UNICOS */
 146 #else
 147 # define SCM_CHAR_CODE_LIMIT 256L
 148 # define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
 149 # if (0 != ~0)
 150 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
 151 # else
 152 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
 153 # endif /*  (0 != ~0) */
 154 #endif /* def HAVE_LIMITS_H */
 155 \f
 156
 157 #ifdef STDC_HEADERS
 158 # include <stdlib.h>
 159 # ifdef AMIGA
 160 #  include <stddef.h>
 161 # endif /* def AMIGA */
 162 # define scm_sizet size_t
 163 #else
 164 # ifdef _SIZE_T
 165 #  define scm_sizet size_t
 166 # else
 167 #  define scm_sizet unsigned int
 168 # endif /* def _SIZE_T */
 169 #endif /* def STDC_HEADERS */
 170
 171 \f
 172
 173 #include "libguile/tags.h"
 174
 175 \f
 176 #ifdef vms
 177 # ifndef CHEAP_CONTINUATIONS
 178    typedef int jmp_buf[17];
 179    extern int setjump(jmp_buf env);
 180    extern int longjump(jmp_buf env, int ret);
 181 #  define setjmp setjump
 182 #  define longjmp longjump
 183 # else
 184 #  include <setjmp.h>
 185 # endif
 186 #else                           /* ndef vms */
 187 # ifdef _CRAY1
 188     typedef int jmp_buf[112];
 189     extern int setjump(jmp_buf env);
 190     extern int longjump(jmp_buf env, int ret);
 191 #  define setjmp setjump
 192 #  define longjmp longjump
 193 # else                          /* ndef _CRAY1 */
 194 #  include <setjmp.h>
 195 # endif                         /* ndef _CRAY1 */
 196 #endif                          /* ndef vms */
 197
 198 /* James Clark came up with this neat one instruction fix for
 199  * continuations on the SPARC.  It flushes the register windows so
 200  * that all the state of the process is contained in the stack.
 201  */
 202
 203 #ifdef sparc
 204 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 205 #else
 206 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 207 #endif
 208
 209 /* If stack is not longword aligned then
 210  */
 211
 212 /* #define SHORT_ALIGN */
 213 #ifdef THINK_C
 214 # define SHORT_ALIGN
 215 #endif
 216 #ifdef MSDOS
 217 # define SHORT_ALIGN
 218 #endif
 219 #ifdef atarist
 220 # define SHORT_ALIGN
 221 #endif
 222
 223 #ifdef SHORT_ALIGN
 224 typedef short SCM_STACKITEM;
 225 #else
 226 typedef long SCM_STACKITEM;
 227 #endif
 228 \f
 229
 230 #ifndef USE_THREADS
 231 #define SCM_THREAD_DEFER
 232 #define SCM_THREAD_ALLOW
 233 #define SCM_THREAD_REDEFER
 234 #define SCM_THREAD_REALLOW_1
 235 #define SCM_THREAD_REALLOW_2
 236 #define SCM_THREAD_SWITCHING_CODE
 237 #endif
 238
 239 extern unsigned int scm_async_clock;
 240
 241 #define SCM_ASYNC_TICK \
 242 do { \
 243   if (0 == --scm_async_clock) \
 244     scm_async_click (); \
 245 } while(0)
 246
 247 #ifdef SCM_CAREFUL_INTS
 248 #define SCM_CHECK_NOT_DISABLED \
 249   if (scm_ints_disabled) \
 250     fputs("ints already disabled\n", stderr); \
 251
 252 #define SCM_CHECK_NOT_ENABLED \
 253   if (!scm_ints_disabled) \
 254     fputs("ints already enabled\n", stderr); \
 255
 256 #else
 257 #define SCM_CHECK_NOT_DISABLED
 258 #define SCM_CHECK_NOT_ENABLED
 259 #endif
 260
 261
 262 /* Anthony Green writes:
 263    When the compiler sees...
 264            DEFER_INTS;
 265            [critical code here]
 266            ALLOW_INTS;
 267    ...it doesn't actually promise to keep the critical code within the
 268    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 269    schedule it outside of the magic defined in those macros.
 270
 271    However, GCC's volatile asm feature forms a barrier over which code is
 272    never moved. So if you add...
 273            asm ("");
 274    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 275    code will always remain in place.  asm's without inputs or outputs
 276    are implicitly volatile. */
 277 #ifdef __GNUC__
 278 #define SCM_FENCE asm /* volatile */ ("")
 279 #else
 280 #define SCM_FENCE
 281 #endif
 282
 283 #define SCM_DEFER_INTS \
 284 do { \
 285   SCM_FENCE; \
 286   SCM_CHECK_NOT_DISABLED; \
 287   SCM_THREAD_DEFER; \
 288   SCM_FENCE; \
 289   scm_ints_disabled = 1; \
 290   SCM_FENCE; \
 291 } while (0)
 292
 293
 294 #define SCM_ALLOW_INTS_ONLY \
 295 do { \
 296   SCM_THREAD_ALLOW; \
 297   scm_ints_disabled = 0; \
 298 } while (0)
 299
 300
 301 #define SCM_ALLOW_INTS \
 302 do { \
 303   SCM_FENCE; \
 304   SCM_CHECK_NOT_ENABLED; \
 305   SCM_THREAD_SWITCHING_CODE; \
 306   SCM_FENCE; \
 307   scm_ints_disabled = 0; \
 308   SCM_FENCE; \
 309   SCM_THREAD_ALLOW; \
 310   SCM_ASYNC_TICK; \
 311   SCM_FENCE; \
 312 } while (0)
 313
 314
 315 #define SCM_REDEFER_INTS  \
 316 do { \
 317   SCM_FENCE; \
 318   SCM_THREAD_REDEFER; \
 319   ++scm_ints_disabled; \
 320   SCM_FENCE; \
 321 } while (0)
 322
 323
 324 #define SCM_REALLOW_INTS \
 325 do { \
 326   SCM_FENCE; \
 327   SCM_THREAD_REALLOW_1; \
 328   SCM_THREAD_SWITCHING_CODE; \
 329   SCM_FENCE; \
 330   --scm_ints_disabled; \
 331   if (!scm_ints_disabled) \
 332     { \
 333       SCM_THREAD_REALLOW_2; \
 334       SCM_ASYNC_TICK; \
 335     } \
 336   SCM_FENCE; \
 337 } while (0)
 338
 339
 340 #define SCM_TICK \
 341 do { \
 342   SCM_DEFER_INTS; \
 343   SCM_ALLOW_INTS; \
 344 } while (0)
 345
 346 \f
 347
 348 /* Classification of critical sections
 349  *
 350  * When Guile moves to POSIX threads, it won't be possible to prevent
 351  * context switching.  In fact, the whole idea of context switching is
 352  * bogus if threads are run by different processors.  Therefore, we
 353  * must ultimately eliminate all critical sections or enforce them by
 354  * use of mutecis.
 355  *
 356  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 357  * be classified and replaced by one of the delimiters below.  If you
 358  * understand what this is all about, I'd like to encourage you to
 359  * help with this task.  The set of classes below must of course be
 360  * incrementally augmented.
 361  *
 362  * MDJ 980419 <djurfeldt@nada.kth.se>
 363  */
 364
 365 /* A sections
 366  *
 367  * Allocation of a cell with type tag in the CAR.
 368  *
 369  * With POSIX threads, each thread will have a private pool of free
 370  * cells.  Therefore, this type of section can be removed.  But!  It
 371  * is important that the CDR is initialized first (with the CAR still
 372  * indicating a free cell) so that we can guarantee a consistent heap
 373  * at all times.
 374  */
 375
 376 #ifdef SCM_POSIX_THREADS
 377 #define SCM_ENTER_A_SECTION
 378 #define SCM_EXIT_A_SECTION
 379 #else
 380 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 381 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 382 #endif
 383
 384 \f
 385
 386 /** SCM_ASSERT
 387  **
 388  **/
 389
 390
 391 #ifdef SCM_RECKLESS
 392 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 393 #define SCM_ASRTGO(_cond, _label)
 394 #else
 395 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 396         if (!(_cond)) \
 397           scm_wta(_arg, (char *)(_pos), _subr)
 398 #define SCM_ASRTGO(_cond, _label) \
 399         if (!(_cond)) \
 400           goto _label
 401 #endif
 402
 403 /*
 404  * SCM_WTA_DISPATCH
 405  */
 406
 407 extern SCM scm_call_generic_0 (SCM gf);
 408
 409 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 410   return ((gf) \
 411           ? scm_call_generic_0 ((gf)) \
 412           : scm_wta ((arg), (char *) (pos), (subr)))
 413 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 414   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (arg), (pos), (subr))
 415
 416 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 417
 418 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 419   return ((gf) \
 420           ? scm_call_generic_1 ((gf), (a1)) \
 421           : scm_wta ((a1), (char *) (pos), (subr)))
 422 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 423   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 424
 425 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 426
 427 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 428   return ((gf) \
 429           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 430           : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
 431 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 432   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 433
 434 extern SCM scm_apply_generic (SCM gf, SCM args);
 435
 436 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 437   return ((gf) \
 438           ? scm_apply_generic ((gf), (args)) \
 439           : scm_wta (scm_list_ref ((args), SCM_MAKINUM ((pos) - 1)), \
 440                      (char *) (pos), \
 441                      (subr)))
 442 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 443   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 444
 445 #ifndef SCM_MAGIC_SNARFER
 446 /* Let these macros pass through if
 447    we are snarfing;  thus we can tell the
 448    difference between the use of an actual
 449    number vs. the use of one of these macros --
 450    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 451    constructs must match the formal argument name,
 452    but using SCM_ARG* avoids the test */
 453
 454 #define SCM_ARGn                0
 455 #define SCM_ARG1                1
 456 #define SCM_ARG2                2
 457 #define SCM_ARG3                3
 458 #define SCM_ARG4                4
 459 #define SCM_ARG5                5
 460 #define SCM_ARG6                6
 461 #define SCM_ARG7                7
 462      /* #define SCM_ARGERR(X)           ((X) < SCM_WNA \
 463                                  ? (char *)(X) \
 464                                  : "wrong type argument")
 465                                  */
 466
 467 /* Following must match entry indexes in scm_errmsgs[].
 468  * Also, SCM_WNA must follow the last SCM_ARGn in sequence.
 469  */
 470 #define SCM_WNA                 8
 471      /* #define SCM_OVSCM_FLOW          9 */
 472 #define SCM_OUTOFRANGE          10
 473 #define SCM_NALLOC              11
 474      /* #define SCM_STACK_OVFLOW        12 */
 475      /* #define SCM_EXIT                13 */
 476
 477 #endif /* SCM_MAGIC_SNARFER */
 478
 479 /* (...still matching scm_errmsgs)  These
 480  * are signals.  Signals may become errors
 481  * but are distinguished because they first
 482  * try to invoke a handler that can resume
 483  * the interrupted routine.
 484  */
 485 #define SCM_HUP_SIGNAL          14
 486 #define SCM_INT_SIGNAL          15
 487 #define SCM_FPE_SIGNAL          16
 488 #define SCM_BUS_SIGNAL          17
 489 #define SCM_SEGV_SIGNAL         18
 490 #define SCM_ALRM_SIGNAL         19
 491 #define SCM_GC_SIGNAL           20
 492 #define SCM_TICK_SIGNAL         21
 493
 494 #define SCM_SIG_ORD(X)          ((X) - SCM_HUP_SIGNAL)
 495 #define SCM_ORD_SIG(X)          ((X) + SCM_HUP_SIGNAL)
 496 #define SCM_NUM_SIGS            (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 497
 498 #if 0
 499 struct errdesc
 500 {
 501   char *msg;
 502   char *s_response;
 503   short parent_err;
 504 };
 505
 506
 507 extern struct errdesc scm_errmsgs[];
 508 #endif
 509
 510 \f
 511
 512 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 513  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 514  * SCM if errors were encountered.  The return code can be explicitly
 515  * specified in a SCM program with (scm_quit <n>).
 516  */
 517
 518 #ifndef SCM_EXIT_SUCCESS
 519 #ifdef vms
 520 #define SCM_EXIT_SUCCESS 1
 521 #else
 522 #define SCM_EXIT_SUCCESS 0
 523 #endif /* def vms */
 524 #endif /* ndef SCM_EXIT_SUCCESS */
 525 #ifndef SCM_EXIT_FAILURE
 526 #ifdef vms
 527 #define SCM_EXIT_FAILURE 2
 528 #else
 529 #define SCM_EXIT_FAILURE 1
 530 #endif /* def vms */
 531 #endif /* ndef SCM_EXIT_FAILURE */
 532
 533
 534
 535 \f
 536
 537 #endif  /* __SCMH */