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 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_SWITCHING_CODE
 235 #endif
 236
 237 extern unsigned int scm_async_clock;
 238
 239 #define SCM_ASYNC_TICK \
 240 do { \
 241   if (0 == --scm_async_clock) \
 242     scm_async_click (); \
 243 } while(0)
 244
 245 #ifdef SCM_CAREFUL_INTS
 246 #define SCM_CHECK_NOT_DISABLED \
 247   if (scm_ints_disabled) \
 248     fputs("ints already disabled\n", stderr); \
 249
 250 #define SCM_CHECK_NOT_ENABLED \
 251   if (!scm_ints_disabled) \
 252     fputs("ints already enabled\n", stderr); \
 253
 254 #else
 255 #define SCM_CHECK_NOT_DISABLED
 256 #define SCM_CHECK_NOT_ENABLED
 257 #endif
 258
 259
 260 /* Anthony Green writes:
 261    When the compiler sees...
 262            DEFER_INTS;
 263            [critical code here]
 264            ALLOW_INTS;
 265    ...it doesn't actually promise to keep the critical code within the
 266    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 267    schedule it outside of the magic defined in those macros.
 268
 269    However, GCC's volatile asm feature forms a barrier over which code is
 270    never moved. So if you add...
 271            asm ("");
 272    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 273    code will always remain in place.  asm's without inputs or outputs
 274    are implicitly volatile. */
 275 #ifdef __GNUC__
 276 #define SCM_FENCE asm /* volatile */ ("")
 277 #else
 278 #define SCM_FENCE
 279 #endif
 280
 281 #define SCM_DEFER_INTS \
 282 do { \
 283   SCM_FENCE; \
 284   SCM_CHECK_NOT_DISABLED; \
 285   SCM_THREAD_DEFER; \
 286   SCM_FENCE; \
 287   scm_ints_disabled = 1; \
 288   SCM_FENCE; \
 289 } while (0)
 290
 291
 292 #define SCM_ALLOW_INTS_ONLY \
 293 do { \
 294   SCM_THREAD_ALLOW; \
 295   scm_ints_disabled = 0; \
 296 } while (0)
 297
 298
 299 #define SCM_ALLOW_INTS \
 300 do { \
 301   SCM_FENCE; \
 302   SCM_CHECK_NOT_ENABLED; \
 303   SCM_THREAD_SWITCHING_CODE; \
 304   SCM_FENCE; \
 305   scm_ints_disabled = 0; \
 306   SCM_FENCE; \
 307   SCM_THREAD_ALLOW; \
 308   SCM_FENCE; \
 309 } while (0)
 310
 311
 312 #define SCM_REDEFER_INTS  \
 313 do { \
 314   SCM_FENCE; \
 315   SCM_THREAD_REDEFER; \
 316   ++scm_ints_disabled; \
 317   SCM_FENCE; \
 318 } while (0)
 319
 320
 321 #define SCM_REALLOW_INTS \
 322 do { \
 323   SCM_FENCE; \
 324   SCM_THREAD_SWITCHING_CODE; \
 325   SCM_FENCE; \
 326   --scm_ints_disabled; \
 327   SCM_FENCE; \
 328 } while (0)
 329
 330
 331 #define SCM_TICK \
 332 do { \
 333   SCM_DEFER_INTS; \
 334   SCM_ALLOW_INTS; \
 335   SCM_ASYNC_TICK; \
 336 } while (0)
 337
 338 \f
 339
 340 /* Classification of critical sections
 341  *
 342  * When Guile moves to POSIX threads, it won't be possible to prevent
 343  * context switching.  In fact, the whole idea of context switching is
 344  * bogus if threads are run by different processors.  Therefore, we
 345  * must ultimately eliminate all critical sections or enforce them by
 346  * use of mutecis.
 347  *
 348  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 349  * be classified and replaced by one of the delimiters below.  If you
 350  * understand what this is all about, I'd like to encourage you to
 351  * help with this task.  The set of classes below must of course be
 352  * incrementally augmented.
 353  *
 354  * MDJ 980419 <djurfeldt@nada.kth.se>
 355  */
 356
 357 /* A sections
 358  *
 359  * Allocation of a cell with type tag in the CAR.
 360  *
 361  * With POSIX threads, each thread will have a private pool of free
 362  * cells.  Therefore, this type of section can be removed.  But!  It
 363  * is important that the CDR is initialized first (with the CAR still
 364  * indicating a free cell) so that we can guarantee a consistent heap
 365  * at all times.
 366  */
 367
 368 #ifdef SCM_POSIX_THREADS
 369 #define SCM_ENTER_A_SECTION
 370 #define SCM_EXIT_A_SECTION
 371 #else
 372 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 373 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 374 #endif
 375
 376 \f
 377
 378 /** SCM_ASSERT
 379  **
 380  **/
 381
 382
 383 #ifdef SCM_RECKLESS
 384 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 385 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr)
 386 #define SCM_ASRTGO(_cond, _label)
 387 #else
 388 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 389         if (!(_cond)) \
 390           scm_wta(_arg, (char *)(_pos), _subr)
 391 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg) \
 392         if (!(_cond)) \
 393           scm_wrong_type_arg_msg(_subr, _pos, _arg, _msg)
 394 #define SCM_ASRTGO(_cond, _label) \
 395         if (!(_cond)) \
 396           goto _label
 397 #endif
 398
 399 /*
 400  * SCM_WTA_DISPATCH
 401  */
 402
 403 extern SCM scm_call_generic_0 (SCM gf);
 404
 405 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 406   return ((gf) \
 407           ? scm_call_generic_0 ((gf)) \
 408           : scm_wta ((arg), (char *) (pos), (subr)))
 409 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 410   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (arg), (pos), (subr))
 411
 412 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 413
 414 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 415   return ((gf) \
 416           ? scm_call_generic_1 ((gf), (a1)) \
 417           : scm_wta ((a1), (char *) (pos), (subr)))
 418 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 419   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 420
 421 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 422
 423 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 424   return ((gf) \
 425           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 426           : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
 427 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 428   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 429
 430 extern SCM scm_apply_generic (SCM gf, SCM args);
 431
 432 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 433   return ((gf) \
 434           ? scm_apply_generic ((gf), (args)) \
 435           : scm_wta (scm_list_ref ((args), SCM_MAKINUM ((pos) - 1)), \
 436                      (char *) (pos), \
 437                      (subr)))
 438 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 439   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 440
 441 #ifndef SCM_MAGIC_SNARFER
 442 /* Let these macros pass through if
 443    we are snarfing;  thus we can tell the
 444    difference between the use of an actual
 445    number vs. the use of one of these macros --
 446    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 447    constructs must match the formal argument name,
 448    but using SCM_ARG* avoids the test */
 449
 450 #define SCM_ARGn                0
 451 #define SCM_ARG1                1
 452 #define SCM_ARG2                2
 453 #define SCM_ARG3                3
 454 #define SCM_ARG4                4
 455 #define SCM_ARG5                5
 456 #define SCM_ARG6                6
 457 #define SCM_ARG7                7
 458      /* #define SCM_ARGERR(X)           ((X) < SCM_WNA \
 459                                  ? (char *)(X) \
 460                                  : "wrong type argument")
 461                                  */
 462
 463 /* Following must match entry indexes in scm_errmsgs[].
 464  * Also, SCM_WNA must follow the last SCM_ARGn in sequence.
 465  */
 466 #define SCM_WNA                 8
 467      /* #define SCM_OVSCM_FLOW          9 */
 468 #define SCM_OUTOFRANGE          10
 469 #define SCM_NALLOC              11
 470      /* #define SCM_STACK_OVFLOW        12 */
 471      /* #define SCM_EXIT                13 */
 472
 473 #endif /* SCM_MAGIC_SNARFER */
 474
 475 /* (...still matching scm_errmsgs)  These
 476  * are signals.  Signals may become errors
 477  * but are distinguished because they first
 478  * try to invoke a handler that can resume
 479  * the interrupted routine.
 480  */
 481 #define SCM_HUP_SIGNAL          14
 482 #define SCM_INT_SIGNAL          15
 483 #define SCM_FPE_SIGNAL          16
 484 #define SCM_BUS_SIGNAL          17
 485 #define SCM_SEGV_SIGNAL         18
 486 #define SCM_ALRM_SIGNAL         19
 487 #define SCM_GC_SIGNAL           20
 488 #define SCM_TICK_SIGNAL         21
 489
 490 #define SCM_SIG_ORD(X)          ((X) - SCM_HUP_SIGNAL)
 491 #define SCM_ORD_SIG(X)          ((X) + SCM_HUP_SIGNAL)
 492 #define SCM_NUM_SIGS            (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 493
 494 #if 0
 495 struct errdesc
 496 {
 497   char *msg;
 498   char *s_response;
 499   short parent_err;
 500 };
 501
 502
 503 extern struct errdesc scm_errmsgs[];
 504 #endif
 505
 506 \f
 507
 508 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 509  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 510  * SCM if errors were encountered.  The return code can be explicitly
 511  * specified in a SCM program with (scm_quit <n>).
 512  */
 513
 514 #ifndef SCM_EXIT_SUCCESS
 515 #ifdef vms
 516 #define SCM_EXIT_SUCCESS 1
 517 #else
 518 #define SCM_EXIT_SUCCESS 0
 519 #endif /* def vms */
 520 #endif /* ndef SCM_EXIT_SUCCESS */
 521 #ifndef SCM_EXIT_FAILURE
 522 #ifdef vms
 523 #define SCM_EXIT_FAILURE 2
 524 #else
 525 #define SCM_EXIT_FAILURE 1
 526 #endif /* def vms */
 527 #endif /* ndef SCM_EXIT_FAILURE */
 528
 529
 530
 531 \f
 532
 533 #endif  /* __SCMH */