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 /* New scheme for garbage collection */
  52 /* #define GUILE_NEW_GC_SCHEME */
  53
  54 /* #define GUILE_DEBUG_FREELIST */
  55
  56 /* If the compile FLAG `SCM_CAUTIOUS' is #defined then the number of
  57  * arguments is always checked for application of closures.  If the
  58  * compile FLAG `SCM_RECKLESS' is #defined then they are not checked.
  59  * Otherwise, number of argument checks for closures are made only when
  60  * the function position (whose value is the closure) of a combination is
  61  * not an ILOC or GLOC.  When the function position of a combination is a
  62  * symbol it will be checked only the first time it is evaluated because
  63  * it will then be replaced with an ILOC or GLOC.
  64  */
  65 #undef SCM_RECKLESS
  66 #define SCM_CAUTIOUS
  67
  68 /* After looking up a local for the first time, rewrite the
  69  * code graph, caching its position.
  70  */
  71 #define MEMOIZE_LOCALS
  72
  73 /* All the number support there is.
  74  */
  75 #define BIGNUMS
  76
  77 /* GC should relinquish empty cons-pair arenas.
  78  */
  79 #define GC_FREE_SEGMENTS
  80
  81 /* Provide a scheme-accessible count-down timer that
  82  * generates a pseudo-interrupt.
  83  */
  84 #define TICKS
  85
  86
  87 /* Use engineering notation when converting numbers strings?
  88  */
  89 #undef ENGNOT
  90
  91 #undef SCM_CAREFUL_INTS
  92 \f
  93 /* {Unsupported Options}
  94  *
  95  * These must be defined as given here.
  96  */
  97
  98
  99 #define CCLO
 100
 101 /* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
 102    have horrible plans for their unification.  */
 103 #undef SICP
 104
 105 \f
 106
 107 /* Random options (not yet supported or in final form). */
 108
 109 #define STACK_CHECKING
 110 #undef NO_CEVAL_STACK_CHECKING
 111
 112 \f
 113 /* What did the configure script discover about the outside world?  */
 114 #include "libguile/scmconfig.h"
 115
 116 #ifdef HAVE_LONG_LONGS
 117
 118 /* Some auto-generated .h files contain unused prototypes
 119  * that need these typedefs.
 120  */
 121 typedef long long long_long;
 122 typedef unsigned long long ulong_long;
 123
 124 #endif /* HAVE_LONG_LONGS */
 125
 126 \f
 127
 128 /* Define
 129  *
 130  * SCM_CHAR_CODE_LIMIT          == UCHAR_MAX + 1
 131  * SCM_MOST_POSITIVE_FIXNUM     (LONG_MAX>>2)
 132  * SCM_MOST_NEGATIVE_FIXNUM     == SCM_SRS((long)LONG_MIN, 2)
 133  */
 134
 135 #ifdef HAVE_LIMITS_H
 136 # include <limits.h>
 137 # ifdef UCHAR_MAX
 138 #  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
 139 # else
 140 #  define SCM_CHAR_CODE_LIMIT 256L
 141 # endif /* def UCHAR_MAX */
 142 # define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
 143 # ifdef _UNICOS                 /* Stupid cray bug */
 144 #  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
 145 # else
 146 #  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
 147 # endif                         /* UNICOS */
 148 #else
 149 # define SCM_CHAR_CODE_LIMIT 256L
 150 # define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
 151 # if (0 != ~0)
 152 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
 153 # else
 154 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
 155 # endif /*  (0 != ~0) */
 156 #endif /* def HAVE_LIMITS_H */
 157 \f
 158
 159 #ifdef STDC_HEADERS
 160 # include <stdlib.h>
 161 # ifdef AMIGA
 162 #  include <stddef.h>
 163 # endif /* def AMIGA */
 164 # define scm_sizet size_t
 165 #else
 166 # ifdef _SIZE_T
 167 #  define scm_sizet size_t
 168 # else
 169 #  define scm_sizet unsigned int
 170 # endif /* def _SIZE_T */
 171 #endif /* def STDC_HEADERS */
 172
 173 \f
 174
 175 #include "libguile/tags.h"
 176
 177 \f
 178 #ifdef vms
 179 # ifndef CHEAP_CONTINUATIONS
 180    typedef int jmp_buf[17];
 181    extern int setjump(jmp_buf env);
 182    extern int longjump(jmp_buf env, int ret);
 183 #  define setjmp setjump
 184 #  define longjmp longjump
 185 # else
 186 #  include <setjmp.h>
 187 # endif
 188 #else                           /* ndef vms */
 189 # ifdef _CRAY1
 190     typedef int jmp_buf[112];
 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                          /* ndef _CRAY1 */
 196 #  include <setjmp.h>
 197 # endif                         /* ndef _CRAY1 */
 198 #endif                          /* ndef vms */
 199
 200 /* James Clark came up with this neat one instruction fix for
 201  * continuations on the SPARC.  It flushes the register windows so
 202  * that all the state of the process is contained in the stack.
 203  */
 204
 205 #ifdef sparc
 206 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 207 #else
 208 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 209 #endif
 210
 211 /* If stack is not longword aligned then
 212  */
 213
 214 /* #define SHORT_ALIGN */
 215 #ifdef THINK_C
 216 # define SHORT_ALIGN
 217 #endif
 218 #ifdef MSDOS
 219 # define SHORT_ALIGN
 220 #endif
 221 #ifdef atarist
 222 # define SHORT_ALIGN
 223 #endif
 224
 225 #ifdef SHORT_ALIGN
 226 typedef short SCM_STACKITEM;
 227 #else
 228 typedef long SCM_STACKITEM;
 229 #endif
 230 \f
 231
 232 #ifndef USE_THREADS
 233 #define SCM_THREAD_DEFER
 234 #define SCM_THREAD_ALLOW
 235 #define SCM_THREAD_REDEFER
 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_FENCE; \
 311 } while (0)
 312
 313
 314 #define SCM_REDEFER_INTS  \
 315 do { \
 316   SCM_FENCE; \
 317   SCM_THREAD_REDEFER; \
 318   ++scm_ints_disabled; \
 319   SCM_FENCE; \
 320 } while (0)
 321
 322
 323 #define SCM_REALLOW_INTS \
 324 do { \
 325   SCM_FENCE; \
 326   SCM_THREAD_SWITCHING_CODE; \
 327   SCM_FENCE; \
 328   --scm_ints_disabled; \
 329   SCM_FENCE; \
 330 } while (0)
 331
 332
 333 #define SCM_TICK \
 334 do { \
 335   SCM_DEFER_INTS; \
 336   SCM_ALLOW_INTS; \
 337   SCM_ASYNC_TICK; \
 338 } while (0)
 339
 340 \f
 341
 342 /* Classification of critical sections
 343  *
 344  * When Guile moves to POSIX threads, it won't be possible to prevent
 345  * context switching.  In fact, the whole idea of context switching is
 346  * bogus if threads are run by different processors.  Therefore, we
 347  * must ultimately eliminate all critical sections or enforce them by
 348  * use of mutecis.
 349  *
 350  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 351  * be classified and replaced by one of the delimiters below.  If you
 352  * understand what this is all about, I'd like to encourage you to
 353  * help with this task.  The set of classes below must of course be
 354  * incrementally augmented.
 355  *
 356  * MDJ 980419 <djurfeldt@nada.kth.se>
 357  */
 358
 359 /* A sections
 360  *
 361  * Allocation of a cell with type tag in the CAR.
 362  *
 363  * With POSIX threads, each thread will have a private pool of free
 364  * cells.  Therefore, this type of section can be removed.  But!  It
 365  * is important that the CDR is initialized first (with the CAR still
 366  * indicating a free cell) so that we can guarantee a consistent heap
 367  * at all times.
 368  */
 369
 370 #ifdef SCM_POSIX_THREADS
 371 #define SCM_ENTER_A_SECTION
 372 #define SCM_EXIT_A_SECTION
 373 #else
 374 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 375 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 376 #endif
 377
 378 \f
 379
 380 /** SCM_ASSERT
 381  **
 382  **/
 383
 384
 385 #ifdef SCM_RECKLESS
 386 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 387 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr)
 388 #define SCM_ASRTGO(_cond, _label)
 389 #else
 390 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 391         if (!(_cond)) \
 392           scm_wta(_arg, (char *)(_pos), _subr)
 393 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg) \
 394         if (!(_cond)) \
 395           scm_wrong_type_arg_msg(_subr, _pos, _arg, _msg)
 396 #define SCM_ASRTGO(_cond, _label) \
 397         if (!(_cond)) \
 398           goto _label
 399 #endif
 400
 401 /*
 402  * SCM_WTA_DISPATCH
 403  */
 404
 405 extern SCM scm_call_generic_0 (SCM gf);
 406
 407 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 408   return ((gf) \
 409           ? scm_call_generic_0 ((gf)) \
 410           : scm_wta ((arg), (char *) (pos), (subr)))
 411 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 412   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (arg), (pos), (subr))
 413
 414 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 415
 416 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 417   return ((gf) \
 418           ? scm_call_generic_1 ((gf), (a1)) \
 419           : scm_wta ((a1), (char *) (pos), (subr)))
 420 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 421   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 422
 423 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 424
 425 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 426   return ((gf) \
 427           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 428           : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
 429 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 430   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 431
 432 extern SCM scm_apply_generic (SCM gf, SCM args);
 433
 434 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 435   return ((gf) \
 436           ? scm_apply_generic ((gf), (args)) \
 437           : scm_wta (scm_list_ref ((args), SCM_MAKINUM ((pos) - 1)), \
 438                      (char *) (pos), \
 439                      (subr)))
 440 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 441   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 442
 443 #ifndef SCM_MAGIC_SNARFER
 444 /* Let these macros pass through if
 445    we are snarfing;  thus we can tell the
 446    difference between the use of an actual
 447    number vs. the use of one of these macros --
 448    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 449    constructs must match the formal argument name,
 450    but using SCM_ARG* avoids the test */
 451
 452 #define SCM_ARGn                0
 453 #define SCM_ARG1                1
 454 #define SCM_ARG2                2
 455 #define SCM_ARG3                3
 456 #define SCM_ARG4                4
 457 #define SCM_ARG5                5
 458 #define SCM_ARG6                6
 459 #define SCM_ARG7                7
 460      /* #define SCM_ARGERR(X)           ((X) < SCM_WNA \
 461                                  ? (char *)(X) \
 462                                  : "wrong type argument")
 463                                  */
 464
 465 /* Following must match entry indexes in scm_errmsgs[].
 466  * Also, SCM_WNA must follow the last SCM_ARGn in sequence.
 467  */
 468 #define SCM_WNA                 8
 469      /* #define SCM_OVSCM_FLOW          9 */
 470 #define SCM_OUTOFRANGE          10
 471 #define SCM_NALLOC              11
 472      /* #define SCM_STACK_OVFLOW        12 */
 473      /* #define SCM_EXIT                13 */
 474
 475 #endif /* SCM_MAGIC_SNARFER */
 476
 477 /* (...still matching scm_errmsgs)  These
 478  * are signals.  Signals may become errors
 479  * but are distinguished because they first
 480  * try to invoke a handler that can resume
 481  * the interrupted routine.
 482  */
 483 #define SCM_HUP_SIGNAL          14
 484 #define SCM_INT_SIGNAL          15
 485 #define SCM_FPE_SIGNAL          16
 486 #define SCM_BUS_SIGNAL          17
 487 #define SCM_SEGV_SIGNAL         18
 488 #define SCM_ALRM_SIGNAL         19
 489 #define SCM_GC_SIGNAL           20
 490 #define SCM_TICK_SIGNAL         21
 491
 492 #define SCM_SIG_ORD(X)          ((X) - SCM_HUP_SIGNAL)
 493 #define SCM_ORD_SIG(X)          ((X) + SCM_HUP_SIGNAL)
 494 #define SCM_NUM_SIGS            (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 495
 496 #if 0
 497 struct errdesc
 498 {
 499   char *msg;
 500   char *s_response;
 501   short parent_err;
 502 };
 503
 504
 505 extern struct errdesc scm_errmsgs[];
 506 #endif
 507
 508 \f
 509
 510 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 511  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 512  * SCM if errors were encountered.  The return code can be explicitly
 513  * specified in a SCM program with (scm_quit <n>).
 514  */
 515
 516 #ifndef SCM_EXIT_SUCCESS
 517 #ifdef vms
 518 #define SCM_EXIT_SUCCESS 1
 519 #else
 520 #define SCM_EXIT_SUCCESS 0
 521 #endif /* def vms */
 522 #endif /* ndef SCM_EXIT_SUCCESS */
 523 #ifndef SCM_EXIT_FAILURE
 524 #ifdef vms
 525 #define SCM_EXIT_FAILURE 2
 526 #else
 527 #define SCM_EXIT_FAILURE 1
 528 #endif /* def vms */
 529 #endif /* ndef SCM_EXIT_FAILURE */
 530
 531
 532
 533 \f
 534
 535 #endif  /* __SCMH */