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
  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 /* New scheme for garbage collection */
  64 #define GUILE_NEW_GC_SCHEME
  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  */
  91 #ifndef GUILE_NEW_GC_SCHEME
  92 #define GC_FREE_SEGMENTS
  93 #endif
  94
  95 /* Provide a scheme-accessible count-down timer that
  96  * generates a pseudo-interrupt.
  97  */
  98 #define TICKS
  99
 100
 101 /* Use engineering notation when converting numbers strings?
 102  */
 103 #undef ENGNOT
 104
 105 #undef SCM_CAREFUL_INTS
 106 \f
 107 /* {Unsupported Options}
 108  *
 109  * These must be defined as given here.
 110  */
 111
 112
 113 #define CCLO
 114
 115 /* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
 116    have horrible plans for their unification.  */
 117 #undef SICP
 118
 119 \f
 120
 121 /* Random options (not yet supported or in final form). */
 122
 123 #define STACK_CHECKING
 124 #undef NO_CEVAL_STACK_CHECKING
 125
 126 \f
 127 /* What did the configure script discover about the outside world?  */
 128 #include "libguile/scmconfig.h"
 129
 130 #ifdef HAVE_LONG_LONGS
 131
 132 /* Some auto-generated .h files contain unused prototypes
 133  * that need these typedefs.
 134  */
 135 typedef long long long_long;
 136 typedef unsigned long long ulong_long;
 137
 138 #endif /* HAVE_LONG_LONGS */
 139
 140 \f
 141
 142 /* Define
 143  *
 144  * SCM_CHAR_CODE_LIMIT          == UCHAR_MAX + 1
 145  * SCM_MOST_POSITIVE_FIXNUM     (LONG_MAX>>2)
 146  * SCM_MOST_NEGATIVE_FIXNUM     == SCM_SRS((long)LONG_MIN, 2)
 147  */
 148
 149 #ifdef HAVE_LIMITS_H
 150 # include <limits.h>
 151 # ifdef UCHAR_MAX
 152 #  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
 153 # else
 154 #  define SCM_CHAR_CODE_LIMIT 256L
 155 # endif /* def UCHAR_MAX */
 156 # define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
 157 # ifdef _UNICOS                 /* Stupid cray bug */
 158 #  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
 159 # else
 160 #  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
 161 # endif                         /* UNICOS */
 162 #else
 163 # define SCM_CHAR_CODE_LIMIT 256L
 164 # define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
 165 # if (0 != ~0)
 166 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
 167 # else
 168 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
 169 # endif /*  (0 != ~0) */
 170 #endif /* def HAVE_LIMITS_H */
 171 \f
 172
 173 #ifdef STDC_HEADERS
 174 # include <stdlib.h>
 175 # ifdef AMIGA
 176 #  include <stddef.h>
 177 # endif /* def AMIGA */
 178 # define scm_sizet size_t
 179 #else
 180 # ifdef _SIZE_T
 181 #  define scm_sizet size_t
 182 # else
 183 #  define scm_sizet unsigned int
 184 # endif /* def _SIZE_T */
 185 #endif /* def STDC_HEADERS */
 186
 187 \f
 188
 189 #include "libguile/tags.h"
 190
 191 \f
 192 #ifdef vms
 193 # ifndef CHEAP_CONTINUATIONS
 194    typedef int jmp_buf[17];
 195    extern int setjump(jmp_buf env);
 196    extern int longjump(jmp_buf env, int ret);
 197 #  define setjmp setjump
 198 #  define longjmp longjump
 199 # else
 200 #  include <setjmp.h>
 201 # endif
 202 #else                           /* ndef vms */
 203 # ifdef _CRAY1
 204     typedef int jmp_buf[112];
 205     extern int setjump(jmp_buf env);
 206     extern int longjump(jmp_buf env, int ret);
 207 #  define setjmp setjump
 208 #  define longjmp longjump
 209 # else                          /* ndef _CRAY1 */
 210 #  include <setjmp.h>
 211 # endif                         /* ndef _CRAY1 */
 212 #endif                          /* ndef vms */
 213
 214 /* James Clark came up with this neat one instruction fix for
 215  * continuations on the SPARC.  It flushes the register windows so
 216  * that all the state of the process is contained in the stack.
 217  */
 218
 219 #ifdef sparc
 220 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 221 #else
 222 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 223 #endif
 224
 225 /* If stack is not longword aligned then
 226  */
 227
 228 /* #define SHORT_ALIGN */
 229 #ifdef THINK_C
 230 # define SHORT_ALIGN
 231 #endif
 232 #ifdef MSDOS
 233 # define SHORT_ALIGN
 234 #endif
 235 #ifdef atarist
 236 # define SHORT_ALIGN
 237 #endif
 238
 239 #ifdef SHORT_ALIGN
 240 typedef short SCM_STACKITEM;
 241 #else
 242 typedef long SCM_STACKITEM;
 243 #endif
 244 \f
 245
 246 #ifndef USE_THREADS
 247 #define SCM_THREAD_DEFER
 248 #define SCM_THREAD_ALLOW
 249 #define SCM_THREAD_REDEFER
 250 #define SCM_THREAD_SWITCHING_CODE
 251 #endif
 252
 253 extern unsigned int scm_async_clock;
 254
 255 #define SCM_ASYNC_TICK \
 256 do { \
 257   if (0 == --scm_async_clock) \
 258     scm_async_click (); \
 259 } while(0)
 260
 261 #ifdef SCM_CAREFUL_INTS
 262 #define SCM_CHECK_NOT_DISABLED \
 263   if (scm_ints_disabled) \
 264     fputs("ints already disabled\n", stderr); \
 265
 266 #define SCM_CHECK_NOT_ENABLED \
 267   if (!scm_ints_disabled) \
 268     fputs("ints already enabled\n", stderr); \
 269
 270 #else
 271 #define SCM_CHECK_NOT_DISABLED
 272 #define SCM_CHECK_NOT_ENABLED
 273 #endif
 274
 275
 276 /* Anthony Green writes:
 277    When the compiler sees...
 278            DEFER_INTS;
 279            [critical code here]
 280            ALLOW_INTS;
 281    ...it doesn't actually promise to keep the critical code within the
 282    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 283    schedule it outside of the magic defined in those macros.
 284
 285    However, GCC's volatile asm feature forms a barrier over which code is
 286    never moved. So if you add...
 287            asm ("");
 288    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 289    code will always remain in place.  asm's without inputs or outputs
 290    are implicitly volatile. */
 291 #ifdef __GNUC__
 292 #define SCM_FENCE asm /* volatile */ ("")
 293 #else
 294 #define SCM_FENCE
 295 #endif
 296
 297 #define SCM_DEFER_INTS \
 298 do { \
 299   SCM_FENCE; \
 300   SCM_CHECK_NOT_DISABLED; \
 301   SCM_THREAD_DEFER; \
 302   SCM_FENCE; \
 303   scm_ints_disabled = 1; \
 304   SCM_FENCE; \
 305 } while (0)
 306
 307
 308 #define SCM_ALLOW_INTS_ONLY \
 309 do { \
 310   SCM_THREAD_ALLOW; \
 311   scm_ints_disabled = 0; \
 312 } while (0)
 313
 314
 315 #define SCM_ALLOW_INTS \
 316 do { \
 317   SCM_FENCE; \
 318   SCM_CHECK_NOT_ENABLED; \
 319   SCM_THREAD_SWITCHING_CODE; \
 320   SCM_FENCE; \
 321   scm_ints_disabled = 0; \
 322   SCM_FENCE; \
 323   SCM_THREAD_ALLOW; \
 324   SCM_FENCE; \
 325 } while (0)
 326
 327
 328 #define SCM_REDEFER_INTS  \
 329 do { \
 330   SCM_FENCE; \
 331   SCM_THREAD_REDEFER; \
 332   ++scm_ints_disabled; \
 333   SCM_FENCE; \
 334 } while (0)
 335
 336
 337 #define SCM_REALLOW_INTS \
 338 do { \
 339   SCM_FENCE; \
 340   SCM_THREAD_SWITCHING_CODE; \
 341   SCM_FENCE; \
 342   --scm_ints_disabled; \
 343   SCM_FENCE; \
 344 } while (0)
 345
 346
 347 #define SCM_TICK \
 348 do { \
 349   SCM_DEFER_INTS; \
 350   SCM_ALLOW_INTS; \
 351   SCM_ASYNC_TICK; \
 352 } while (0)
 353
 354 \f
 355
 356 /* Classification of critical sections
 357  *
 358  * When Guile moves to POSIX threads, it won't be possible to prevent
 359  * context switching.  In fact, the whole idea of context switching is
 360  * bogus if threads are run by different processors.  Therefore, we
 361  * must ultimately eliminate all critical sections or enforce them by
 362  * use of mutecis.
 363  *
 364  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 365  * be classified and replaced by one of the delimiters below.  If you
 366  * understand what this is all about, I'd like to encourage you to
 367  * help with this task.  The set of classes below must of course be
 368  * incrementally augmented.
 369  *
 370  * MDJ 980419 <djurfeldt@nada.kth.se>
 371  */
 372
 373 /* A sections
 374  *
 375  * Allocation of a cell with type tag in the CAR.
 376  *
 377  * With POSIX threads, each thread will have a private pool of free
 378  * cells.  Therefore, this type of section can be removed.  But!  It
 379  * is important that the CDR is initialized first (with the CAR still
 380  * indicating a free cell) so that we can guarantee a consistent heap
 381  * at all times.
 382  */
 383
 384 #ifdef SCM_POSIX_THREADS
 385 #define SCM_ENTER_A_SECTION
 386 #define SCM_EXIT_A_SECTION
 387 #else
 388 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 389 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 390 #endif
 391
 392 \f
 393
 394 /** SCM_ASSERT
 395  **
 396  **/
 397
 398
 399 #ifdef SCM_RECKLESS
 400 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 401 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr)
 402 #define SCM_ASRTGO(_cond, _label)
 403 #else
 404 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 405         if (!(_cond)) \
 406           scm_wta(_arg, (char *)(_pos), _subr)
 407 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg) \
 408         if (!(_cond)) \
 409           scm_wrong_type_arg_msg(_subr, _pos, _arg, _msg)
 410 #define SCM_ASRTGO(_cond, _label) \
 411         if (!(_cond)) \
 412           goto _label
 413 #endif
 414
 415 /*
 416  * SCM_WTA_DISPATCH
 417  */
 418
 419 extern SCM scm_call_generic_0 (SCM gf);
 420
 421 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 422   return ((gf) \
 423           ? scm_call_generic_0 ((gf)) \
 424           : scm_wta ((arg), (char *) (pos), (subr)))
 425 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 426   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (arg), (pos), (subr))
 427
 428 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 429
 430 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 431   return ((gf) \
 432           ? scm_call_generic_1 ((gf), (a1)) \
 433           : scm_wta ((a1), (char *) (pos), (subr)))
 434 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 435   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 436
 437 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 438
 439 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 440   return ((gf) \
 441           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 442           : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
 443 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 444   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 445
 446 extern SCM scm_apply_generic (SCM gf, SCM args);
 447
 448 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 449   return ((gf) \
 450           ? scm_apply_generic ((gf), (args)) \
 451           : scm_wta (scm_list_ref ((args), SCM_MAKINUM ((pos) - 1)), \
 452                      (char *) (pos), \
 453                      (subr)))
 454 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 455   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 456
 457 #ifndef SCM_MAGIC_SNARFER
 458 /* Let these macros pass through if
 459    we are snarfing;  thus we can tell the
 460    difference between the use of an actual
 461    number vs. the use of one of these macros --
 462    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 463    constructs must match the formal argument name,
 464    but using SCM_ARG* avoids the test */
 465
 466 #define SCM_ARGn                0
 467 #define SCM_ARG1                1
 468 #define SCM_ARG2                2
 469 #define SCM_ARG3                3
 470 #define SCM_ARG4                4
 471 #define SCM_ARG5                5
 472 #define SCM_ARG6                6
 473 #define SCM_ARG7                7
 474      /* #define SCM_ARGERR(X)           ((X) < SCM_WNA \
 475                                  ? (char *)(X) \
 476                                  : "wrong type argument")
 477                                  */
 478
 479 /* Following must match entry indexes in scm_errmsgs[].
 480  * Also, SCM_WNA must follow the last SCM_ARGn in sequence.
 481  */
 482 #define SCM_WNA                 8
 483      /* #define SCM_OVSCM_FLOW          9 */
 484 #define SCM_OUTOFRANGE          10
 485 #define SCM_NALLOC              11
 486      /* #define SCM_STACK_OVFLOW        12 */
 487      /* #define SCM_EXIT                13 */
 488
 489 #endif /* SCM_MAGIC_SNARFER */
 490
 491 /* (...still matching scm_errmsgs)  These
 492  * are signals.  Signals may become errors
 493  * but are distinguished because they first
 494  * try to invoke a handler that can resume
 495  * the interrupted routine.
 496  */
 497 #define SCM_HUP_SIGNAL          14
 498 #define SCM_INT_SIGNAL          15
 499 #define SCM_FPE_SIGNAL          16
 500 #define SCM_BUS_SIGNAL          17
 501 #define SCM_SEGV_SIGNAL         18
 502 #define SCM_ALRM_SIGNAL         19
 503 #define SCM_GC_SIGNAL           20
 504 #define SCM_TICK_SIGNAL         21
 505
 506 #define SCM_SIG_ORD(X)          ((X) - SCM_HUP_SIGNAL)
 507 #define SCM_ORD_SIG(X)          ((X) + SCM_HUP_SIGNAL)
 508 #define SCM_NUM_SIGS            (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 509
 510 #if 0
 511 struct errdesc
 512 {
 513   char *msg;
 514   char *s_response;
 515   short parent_err;
 516 };
 517
 518
 519 extern struct errdesc scm_errmsgs[];
 520 #endif
 521
 522 \f
 523
 524 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 525  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 526  * SCM if errors were encountered.  The return code can be explicitly
 527  * specified in a SCM program with (scm_quit <n>).
 528  */
 529
 530 #ifndef SCM_EXIT_SUCCESS
 531 #ifdef vms
 532 #define SCM_EXIT_SUCCESS 1
 533 #else
 534 #define SCM_EXIT_SUCCESS 0
 535 #endif /* def vms */
 536 #endif /* ndef SCM_EXIT_SUCCESS */
 537 #ifndef SCM_EXIT_FAILURE
 538 #ifdef vms
 539 #define SCM_EXIT_FAILURE 2
 540 #else
 541 #define SCM_EXIT_FAILURE 1
 542 #endif /* def vms */
 543 #endif /* ndef SCM_EXIT_FAILURE */
 544
 545
 546
 547 \f
 548
 549 #endif  /* __SCMH */