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 /* If the compile FLAG `SCM_CAUTIOUS' is #defined then the number of
  52  * arguments is always checked for application of closures.  If the
  53  * compile FLAG `SCM_RECKLESS' is #defined then they are not checked.
  54  * Otherwise, number of argument checks for closures are made only when
  55  * the function position (whose value is the closure) of a combination is
  56  * not an ILOC or GLOC.  When the function position of a combination is a
  57  * symbol it will be checked only the first time it is evaluated because
  58  * it will then be replaced with an ILOC or GLOC.
  59  */
  60 #undef SCM_RECKLESS
  61 #define SCM_CAUTIOUS
  62
  63 /* After looking up a local for the first time, rewrite the
  64  * code graph, caching its position.
  65  */
  66 #define MEMOIZE_LOCALS
  67
  68 /* All the number support there is.
  69  */
  70 #define SCM_FLOATS
  71 #define BIGNUMS
  72
  73 /* GC should relinquish empty cons-pair arenas.
  74  */
  75 #define GC_FREE_SEGMENTS
  76
  77 /* Provide a scheme-accessible count-down timer that
  78  * generates a pseudo-interrupt.
  79  */
  80 #define TICKS
  81
  82
  83 /* Use engineering notation when converting numbers strings?
  84  */
  85 #undef ENGNOT
  86
  87 /* Include support for uniform arrays?
  88  *
  89  * Possibly some of the initialization code depends on this
  90  * being defined, but that is a bug and should be fixed.
  91  */
  92 #define ARRAYS
  93
  94 #undef SCM_CAREFUL_INTS
  95 \f
  96 /* {Unsupported Options}
  97  *
  98  * These must be defined as given here.
  99  */
 100
 101
 102 #define CCLO
 103
 104 /* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
 105    have horrible plans for their unification.  */
 106 #undef SICP
 107
 108 \f
 109
 110 /* Random options (not yet supported or in final form). */
 111
 112 #define STACK_CHECKING
 113 #undef NO_CEVAL_STACK_CHECKING
 114 #undef LONGLONGS
 115
 116 /* Some auto-generated .h files contain unused prototypes
 117  * that need these typedefs.
 118  */
 119 typedef long long_long;
 120 typedef unsigned long ulong_long;
 121
 122
 123 \f
 124 /* What did the configure script discover about the outside world?  */
 125 #include "libguile/scmconfig.h"
 126
 127 \f
 128 /* Write prototype declarations like this:
 129      int foo SCM_P ((int a, int b));
 130    At definitions, use K&R style declarations, but make sure there's a
 131    declarative prototype (as above) in scope.  This will give you
 132    argument type checking, when available, and be harmless otherwise.  */
 133 #ifdef __STDC__
 134 #  define SCM_P(x) x
 135 #else
 136 #  define SCM_P(x) ()
 137 #endif
 138
 139 \f
 140
 141 /* Define
 142  *
 143  * SCM_CHAR_CODE_LIMIT          == UCHAR_MAX + 1
 144  * SCM_MOST_POSITIVE_FIXNUM     (LONG_MAX>>2)
 145  * SCM_MOST_NEGATIVE_FIXNUM     == SCM_SRS((long)LONG_MIN, 2)
 146  */
 147
 148 #ifdef HAVE_LIMITS_H
 149 # include <limits.h>
 150 # ifdef UCHAR_MAX
 151 #  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
 152 # else
 153 #  define SCM_CHAR_CODE_LIMIT 256L
 154 # endif /* def UCHAR_MAX */
 155 # define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
 156 # ifdef _UNICOS                 /* Stupid cray bug */
 157 #  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
 158 # else
 159 #  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
 160 # endif                         /* UNICOS */
 161 #else
 162 # define SCM_CHAR_CODE_LIMIT 256L
 163 # define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
 164 # if (0 != ~0)
 165 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
 166 # else
 167 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
 168 # endif /*  (0 != ~0) */
 169 #endif /* def HAVE_LIMITS_H */
 170 \f
 171
 172 #ifdef STDC_HEADERS
 173 # include <stdlib.h>
 174 # ifdef AMIGA
 175 #  include <stddef.h>
 176 # endif /* def AMIGA */
 177 # define scm_sizet size_t
 178 #else
 179 # ifdef _SIZE_T
 180 #  define scm_sizet size_t
 181 # else
 182 #  define scm_sizet unsigned int
 183 # endif /* def _SIZE_T */
 184 #endif /* def STDC_HEADERS */
 185
 186 \f
 187
 188 #include "libguile/tags.h"
 189
 190 \f
 191 #ifdef vms
 192 # ifndef CHEAP_CONTINUATIONS
 193    typedef int jmp_buf[17];
 194    extern int setjump(jmp_buf env);
 195    extern int longjump(jmp_buf env, int ret);
 196 #  define setjmp setjump
 197 #  define longjmp longjump
 198 # else
 199 #  include <setjmp.h>
 200 # endif
 201 #else                           /* ndef vms */
 202 # ifdef _CRAY1
 203     typedef int jmp_buf[112];
 204     extern int setjump(jmp_buf env);
 205     extern int longjump(jmp_buf env, int ret);
 206 #  define setjmp setjump
 207 #  define longjmp longjump
 208 # else                          /* ndef _CRAY1 */
 209 #  include <setjmp.h>
 210 # endif                         /* ndef _CRAY1 */
 211 #endif                          /* ndef vms */
 212
 213 /* James Clark came up with this neat one instruction fix for
 214  * continuations on the SPARC.  It flushes the register windows so
 215  * that all the state of the process is contained in the stack.
 216  */
 217
 218 #ifdef sparc
 219 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 220 #else
 221 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 222 #endif
 223
 224 /* If stack is not longword aligned then
 225  */
 226
 227 /* #define SHORT_ALIGN */
 228 #ifdef THINK_C
 229 # define SHORT_ALIGN
 230 #endif
 231 #ifdef MSDOS
 232 # define SHORT_ALIGN
 233 #endif
 234 #ifdef atarist
 235 # define SHORT_ALIGN
 236 #endif
 237
 238 #ifdef SHORT_ALIGN
 239 typedef short SCM_STACKITEM;
 240 #else
 241 typedef long SCM_STACKITEM;
 242 #endif
 243 \f
 244
 245 #ifndef USE_THREADS
 246 #define SCM_THREAD_DEFER
 247 #define SCM_THREAD_ALLOW
 248 #define SCM_THREAD_REDEFER
 249 #define SCM_THREAD_REALLOW_1
 250 #define SCM_THREAD_REALLOW_2
 251 #define SCM_THREAD_SWITCHING_CODE
 252 #endif
 253
 254 extern unsigned int scm_async_clock;
 255
 256 #define SCM_ASYNC_TICK \
 257 { \
 258   if (0 == --scm_async_clock) \
 259     scm_async_click (); \
 260 } \
 261
 262 #ifdef SCM_CAREFUL_INTS
 263 #define SCM_CHECK_NOT_DISABLED \
 264   if (scm_ints_disabled) \
 265     fputs("ints already disabled\n", stderr); \
 266
 267 #define SCM_CHECK_NOT_ENABLED \
 268   if (!scm_ints_disabled) \
 269     fputs("ints already enabled\n", stderr); \
 270
 271 #else
 272 #define SCM_CHECK_NOT_DISABLED
 273 #define SCM_CHECK_NOT_ENABLED
 274 #endif
 275
 276
 277 /* Anthony Green writes:
 278    When the compiler sees...
 279            DEFER_INTS;
 280            [critical code here]
 281            ALLOW_INTS;
 282    ...it doesn't actually promise to keep the critical code within the
 283    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 284    schedule it outside of the magic defined in those macros.
 285
 286    However, GCC's volatile asm feature forms a barrier over which code is
 287    never moved. So if you add...
 288            asm ("");
 289    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 290    code will always remain in place.  asm's without inputs or outputs
 291    are implicitly volatile. */
 292 #ifdef __GNUC__
 293 #define SCM_FENCE asm /* volatile */ ("")
 294 #else
 295 #define SCM_FENCE
 296 #endif
 297
 298 #define SCM_DEFER_INTS \
 299 { \
 300   SCM_FENCE; \
 301   SCM_CHECK_NOT_DISABLED; \
 302   SCM_THREAD_DEFER; \
 303   SCM_FENCE; \
 304   scm_ints_disabled = 1; \
 305   SCM_FENCE; \
 306 } \
 307
 308
 309 #define SCM_ALLOW_INTS_ONLY \
 310 { \
 311   SCM_THREAD_ALLOW; \
 312   scm_ints_disabled = 0; \
 313 } \
 314
 315
 316 #define SCM_ALLOW_INTS \
 317 { \
 318   SCM_FENCE; \
 319   SCM_CHECK_NOT_ENABLED; \
 320   SCM_THREAD_SWITCHING_CODE; \
 321   SCM_FENCE; \
 322   scm_ints_disabled = 0; \
 323   SCM_FENCE; \
 324   SCM_THREAD_ALLOW; \
 325   SCM_ASYNC_TICK; \
 326   SCM_FENCE; \
 327 } \
 328
 329
 330 #define SCM_REDEFER_INTS  \
 331 { \
 332   SCM_FENCE; \
 333   SCM_THREAD_REDEFER; \
 334   ++scm_ints_disabled; \
 335   SCM_FENCE; \
 336 } \
 337
 338
 339 #define SCM_REALLOW_INTS \
 340 { \
 341   SCM_FENCE; \
 342   SCM_THREAD_REALLOW_1; \
 343   SCM_THREAD_SWITCHING_CODE; \
 344   SCM_FENCE; \
 345   --scm_ints_disabled; \
 346   if (!scm_ints_disabled) \
 347     { \
 348       SCM_THREAD_REALLOW_2; \
 349       SCM_ASYNC_TICK; \
 350     } \
 351   SCM_FENCE; \
 352 } \
 353
 354
 355 #define SCM_TICK \
 356 { \
 357   SCM_DEFER_INTS; \
 358   SCM_ALLOW_INTS; \
 359 } \
 360
 361 \f
 362
 363 /* Classification of critical sections
 364  *
 365  * When Guile moves to POSIX threads, it won't be possible to prevent
 366  * context switching.  In fact, the whole idea of context switching is
 367  * bogus if threads are run by different processors.  Therefore, we
 368  * must ultimately eliminate all critical sections or enforce them by
 369  * use of mutecis.
 370  *
 371  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 372  * be classified and replaced by one of the delimiters below.  If you
 373  * understand what this is all about, I'd like to encourage you to
 374  * help with this task.  The set of classes below must of course be
 375  * incrementally augmented.
 376  *
 377  * MDJ 980419 <djurfeldt@nada.kth.se>
 378  */
 379
 380 /* A sections
 381  *
 382  * Allocation of a cell with type tag in the CAR.
 383  *
 384  * With POSIX threads, each thread will have a private pool of free
 385  * cells.  Therefore, this type of section can be removed.  But!  It
 386  * is important that the CDR is initialized first (with the CAR still
 387  * indicating a free cell) so that we can guarantee a consistent heap
 388  * at all times.
 389  */
 390
 391 #ifdef SCM_POSIX_THREADS
 392 #define SCM_ENTER_A_SECTION
 393 #define SCM_EXIT_A_SECTION
 394 #else
 395 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 396 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 397 #endif
 398
 399 \f
 400
 401 /** SCM_ASSERT
 402  **
 403  **/
 404
 405
 406 #ifdef SCM_RECKLESS
 407 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 408 #define SCM_ASRTGO(_cond, _label)
 409 #else
 410 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 411         if (!(_cond)) \
 412           scm_wta(_arg, (char *)(_pos), _subr)
 413 #define SCM_ASRTGO(_cond, _label) \
 414         if (!(_cond)) \
 415           goto _label
 416 #endif
 417
 418 /*
 419  * SCM_WTA_DISPATCH
 420  */
 421
 422 extern SCM scm_call_generic_0 (SCM gf);
 423
 424 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 425   return ((gf) \
 426           ? scm_call_generic_0 ((gf)) \
 427           : scm_wta ((arg), (char *) (pos), (subr)))
 428 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 429   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (arg), (pos), (subr))
 430
 431 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 432
 433 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 434   return ((gf) \
 435           ? scm_call_generic_1 ((gf), (a1)) \
 436           : scm_wta ((a1), (char *) (pos), (subr)))
 437 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 438   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 439
 440 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 441
 442 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 443   return ((gf) \
 444           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 445           : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
 446 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 447   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 448
 449 extern SCM scm_apply_generic (SCM gf, SCM args);
 450
 451 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 452   return ((gf) \
 453           ? scm_apply_generic ((gf), (args)) \
 454           : scm_wta (scm_list_ref ((args), SCM_MAKINUM ((pos) - 1)), \
 455                      (char *) (pos), \
 456                      (subr)))
 457 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 458   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 459
 460 #define SCM_ARGn                0
 461 #define SCM_ARG1                1
 462 #define SCM_ARG2                2
 463 #define SCM_ARG3                3
 464 #define SCM_ARG4                4
 465 #define SCM_ARG5                5
 466 #define SCM_ARG6                6
 467 #define SCM_ARG7                7
 468      /* #define SCM_ARGERR(X)           ((X) < SCM_WNA \
 469                                  ? (char *)(X) \
 470                                  : "wrong type argument")
 471                                  */
 472
 473 /* Following must match entry indexes in scm_errmsgs[].
 474  * Also, SCM_WNA must follow the last SCM_ARGn in sequence.
 475  */
 476 #define SCM_WNA                 8
 477      /* #define SCM_OVSCM_FLOW          9 */
 478 #define SCM_OUTOFRANGE          10
 479 #define SCM_NALLOC              11
 480      /* #define SCM_STACK_OVFLOW        12 */
 481      /* #define SCM_EXIT                13 */
 482
 483
 484 /* (...still matching scm_errmsgs)  These
 485  * are signals.  Signals may become errors
 486  * but are distinguished because they first
 487  * try to invoke a handler that can resume
 488  * the interrupted routine.
 489  */
 490 #define SCM_HUP_SIGNAL          14
 491 #define SCM_INT_SIGNAL          15
 492 #define SCM_FPE_SIGNAL          16
 493 #define SCM_BUS_SIGNAL          17
 494 #define SCM_SEGV_SIGNAL         18
 495 #define SCM_ALRM_SIGNAL         19
 496 #define SCM_GC_SIGNAL           20
 497 #define SCM_TICK_SIGNAL         21
 498
 499 #define SCM_SIG_ORD(X)          ((X) - SCM_HUP_SIGNAL)
 500 #define SCM_ORD_SIG(X)          ((X) + SCM_HUP_SIGNAL)
 501 #define SCM_NUM_SIGS            (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 502
 503 #if 0
 504 struct errdesc
 505 {
 506   char *msg;
 507   char *s_response;
 508   short parent_err;
 509 };
 510
 511
 512 extern struct errdesc scm_errmsgs[];
 513 #endif
 514
 515 \f
 516
 517 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 518  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 519  * SCM if errors were encountered.  The return code can be explicitly
 520  * specified in a SCM program with (scm_quit <n>).
 521  */
 522
 523 #ifndef SCM_EXIT_SUCCESS
 524 #ifdef vms
 525 #define SCM_EXIT_SUCCESS 1
 526 #else
 527 #define SCM_EXIT_SUCCESS 0
 528 #endif /* def vms */
 529 #endif /* ndef SCM_EXIT_SUCCESS */
 530 #ifndef SCM_EXIT_FAILURE
 531 #ifdef vms
 532 #define SCM_EXIT_FAILURE 2
 533 #else
 534 #define SCM_EXIT_FAILURE 1
 535 #endif /* def vms */
 536 #endif /* ndef SCM_EXIT_FAILURE */
 537
 538
 539
 540 \f
 541
 542 #endif  /* __SCMH */