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 /* Write prototype declarations like this:
 126      int foo SCM_P ((int a, int b));
 127    At definitions, use K&R style declarations, but make sure there's a
 128    declarative prototype (as above) in scope.  This will give you
 129    argument type checking, when available, and be harmless otherwise.  */
 130 #ifdef __STDC__
 131 #  define SCM_P(x) x
 132 #else
 133 #  define SCM_P(x) ()
 134 #endif
 135
 136 \f
 137
 138 /* Define
 139  *
 140  * SCM_CHAR_CODE_LIMIT          == UCHAR_MAX + 1
 141  * SCM_MOST_POSITIVE_FIXNUM     (LONG_MAX>>2)
 142  * SCM_MOST_NEGATIVE_FIXNUM     == SCM_SRS((long)LONG_MIN, 2)
 143  */
 144
 145 #ifdef HAVE_LIMITS_H
 146 # include <limits.h>
 147 # ifdef UCHAR_MAX
 148 #  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
 149 # else
 150 #  define SCM_CHAR_CODE_LIMIT 256L
 151 # endif /* def UCHAR_MAX */
 152 # define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
 153 # ifdef _UNICOS                 /* Stupid cray bug */
 154 #  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
 155 # else
 156 #  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
 157 # endif                         /* UNICOS */
 158 #else
 159 # define SCM_CHAR_CODE_LIMIT 256L
 160 # define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
 161 # if (0 != ~0)
 162 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
 163 # else
 164 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
 165 # endif /*  (0 != ~0) */
 166 #endif /* def HAVE_LIMITS_H */
 167 \f
 168
 169 #ifdef STDC_HEADERS
 170 # include <stdlib.h>
 171 # ifdef AMIGA
 172 #  include <stddef.h>
 173 # endif /* def AMIGA */
 174 # define scm_sizet size_t
 175 #else
 176 # ifdef _SIZE_T
 177 #  define scm_sizet size_t
 178 # else
 179 #  define scm_sizet unsigned int
 180 # endif /* def _SIZE_T */
 181 #endif /* def STDC_HEADERS */
 182
 183 \f
 184
 185 #include "libguile/tags.h"
 186
 187 \f
 188 #ifdef vms
 189 # ifndef CHEAP_CONTINUATIONS
 190    typedef int jmp_buf[17];
 191    extern int setjump(jmp_buf env);
 192    extern int longjump(jmp_buf env, int ret);
 193 #  define setjmp setjump
 194 #  define longjmp longjump
 195 # else
 196 #  include <setjmp.h>
 197 # endif
 198 #else                           /* ndef vms */
 199 # ifdef _CRAY1
 200     typedef int jmp_buf[112];
 201     extern int setjump(jmp_buf env);
 202     extern int longjump(jmp_buf env, int ret);
 203 #  define setjmp setjump
 204 #  define longjmp longjump
 205 # else                          /* ndef _CRAY1 */
 206 #  include <setjmp.h>
 207 # endif                         /* ndef _CRAY1 */
 208 #endif                          /* ndef vms */
 209
 210 /* James Clark came up with this neat one instruction fix for
 211  * continuations on the SPARC.  It flushes the register windows so
 212  * that all the state of the process is contained in the stack.
 213  */
 214
 215 #ifdef sparc
 216 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 217 #else
 218 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 219 #endif
 220
 221 /* If stack is not longword aligned then
 222  */
 223
 224 /* #define SHORT_ALIGN */
 225 #ifdef THINK_C
 226 # define SHORT_ALIGN
 227 #endif
 228 #ifdef MSDOS
 229 # define SHORT_ALIGN
 230 #endif
 231 #ifdef atarist
 232 # define SHORT_ALIGN
 233 #endif
 234
 235 #ifdef SHORT_ALIGN
 236 typedef short SCM_STACKITEM;
 237 #else
 238 typedef long SCM_STACKITEM;
 239 #endif
 240 \f
 241
 242 #ifndef USE_THREADS
 243 #define SCM_THREAD_DEFER
 244 #define SCM_THREAD_ALLOW
 245 #define SCM_THREAD_REDEFER
 246 #define SCM_THREAD_REALLOW_1
 247 #define SCM_THREAD_REALLOW_2
 248 #define SCM_THREAD_SWITCHING_CODE
 249 #endif
 250
 251 extern unsigned int scm_async_clock;
 252
 253 #define SCM_ASYNC_TICK \
 254 do { \
 255   if (0 == --scm_async_clock) \
 256     scm_async_click (); \
 257 } while(0)
 258
 259 #ifdef SCM_CAREFUL_INTS
 260 #define SCM_CHECK_NOT_DISABLED \
 261   if (scm_ints_disabled) \
 262     fputs("ints already disabled\n", stderr); \
 263
 264 #define SCM_CHECK_NOT_ENABLED \
 265   if (!scm_ints_disabled) \
 266     fputs("ints already enabled\n", stderr); \
 267
 268 #else
 269 #define SCM_CHECK_NOT_DISABLED
 270 #define SCM_CHECK_NOT_ENABLED
 271 #endif
 272
 273
 274 /* Anthony Green writes:
 275    When the compiler sees...
 276            DEFER_INTS;
 277            [critical code here]
 278            ALLOW_INTS;
 279    ...it doesn't actually promise to keep the critical code within the
 280    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 281    schedule it outside of the magic defined in those macros.
 282
 283    However, GCC's volatile asm feature forms a barrier over which code is
 284    never moved. So if you add...
 285            asm ("");
 286    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 287    code will always remain in place.  asm's without inputs or outputs
 288    are implicitly volatile. */
 289 #ifdef __GNUC__
 290 #define SCM_FENCE asm /* volatile */ ("")
 291 #else
 292 #define SCM_FENCE
 293 #endif
 294
 295 #define SCM_DEFER_INTS \
 296 do { \
 297   SCM_FENCE; \
 298   SCM_CHECK_NOT_DISABLED; \
 299   SCM_THREAD_DEFER; \
 300   SCM_FENCE; \
 301   scm_ints_disabled = 1; \
 302   SCM_FENCE; \
 303 } while (0)
 304
 305
 306 #define SCM_ALLOW_INTS_ONLY \
 307 do { \
 308   SCM_THREAD_ALLOW; \
 309   scm_ints_disabled = 0; \
 310 } while (0)
 311
 312
 313 #define SCM_ALLOW_INTS \
 314 do { \
 315   SCM_FENCE; \
 316   SCM_CHECK_NOT_ENABLED; \
 317   SCM_THREAD_SWITCHING_CODE; \
 318   SCM_FENCE; \
 319   scm_ints_disabled = 0; \
 320   SCM_FENCE; \
 321   SCM_THREAD_ALLOW; \
 322   SCM_ASYNC_TICK; \
 323   SCM_FENCE; \
 324 } while (0)
 325
 326
 327 #define SCM_REDEFER_INTS  \
 328 do { \
 329   SCM_FENCE; \
 330   SCM_THREAD_REDEFER; \
 331   ++scm_ints_disabled; \
 332   SCM_FENCE; \
 333 } while (0)
 334
 335
 336 #define SCM_REALLOW_INTS \
 337 do { \
 338   SCM_FENCE; \
 339   SCM_THREAD_REALLOW_1; \
 340   SCM_THREAD_SWITCHING_CODE; \
 341   SCM_FENCE; \
 342   --scm_ints_disabled; \
 343   if (!scm_ints_disabled) \
 344     { \
 345       SCM_THREAD_REALLOW_2; \
 346       SCM_ASYNC_TICK; \
 347     } \
 348   SCM_FENCE; \
 349 } while (0)
 350
 351
 352 #define SCM_TICK \
 353 do { \
 354   SCM_DEFER_INTS; \
 355   SCM_ALLOW_INTS; \
 356 } while (0)
 357
 358 \f
 359
 360 /* Classification of critical sections
 361  *
 362  * When Guile moves to POSIX threads, it won't be possible to prevent
 363  * context switching.  In fact, the whole idea of context switching is
 364  * bogus if threads are run by different processors.  Therefore, we
 365  * must ultimately eliminate all critical sections or enforce them by
 366  * use of mutecis.
 367  *
 368  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 369  * be classified and replaced by one of the delimiters below.  If you
 370  * understand what this is all about, I'd like to encourage you to
 371  * help with this task.  The set of classes below must of course be
 372  * incrementally augmented.
 373  *
 374  * MDJ 980419 <djurfeldt@nada.kth.se>
 375  */
 376
 377 /* A sections
 378  *
 379  * Allocation of a cell with type tag in the CAR.
 380  *
 381  * With POSIX threads, each thread will have a private pool of free
 382  * cells.  Therefore, this type of section can be removed.  But!  It
 383  * is important that the CDR is initialized first (with the CAR still
 384  * indicating a free cell) so that we can guarantee a consistent heap
 385  * at all times.
 386  */
 387
 388 #ifdef SCM_POSIX_THREADS
 389 #define SCM_ENTER_A_SECTION
 390 #define SCM_EXIT_A_SECTION
 391 #else
 392 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 393 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 394 #endif
 395
 396 \f
 397
 398 /** SCM_ASSERT
 399  **
 400  **/
 401
 402
 403 #ifdef SCM_RECKLESS
 404 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 405 #define SCM_ASRTGO(_cond, _label)
 406 #else
 407 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 408         if (!(_cond)) \
 409           scm_wta(_arg, (char *)(_pos), _subr)
 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 */