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 /* Some auto-generated .h files contain unused prototypes
 111  * that need these typedefs.
 112  */
 113 typedef long long long_long;
 114 typedef unsigned long long ulong_long;
 115
 116
 117 \f
 118 /* What did the configure script discover about the outside world?  */
 119 #include "libguile/scmconfig.h"
 120
 121 \f
 122 /* Write prototype declarations like this:
 123      int foo SCM_P ((int a, int b));
 124    At definitions, use K&R style declarations, but make sure there's a
 125    declarative prototype (as above) in scope.  This will give you
 126    argument type checking, when available, and be harmless otherwise.  */
 127 #ifdef __STDC__
 128 #  define SCM_P(x) x
 129 #else
 130 #  define SCM_P(x) ()
 131 #endif
 132
 133 \f
 134
 135 /* Define
 136  *
 137  * SCM_CHAR_CODE_LIMIT          == UCHAR_MAX + 1
 138  * SCM_MOST_POSITIVE_FIXNUM     (LONG_MAX>>2)
 139  * SCM_MOST_NEGATIVE_FIXNUM     == SCM_SRS((long)LONG_MIN, 2)
 140  */
 141
 142 #ifdef HAVE_LIMITS_H
 143 # include <limits.h>
 144 # ifdef UCHAR_MAX
 145 #  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
 146 # else
 147 #  define SCM_CHAR_CODE_LIMIT 256L
 148 # endif /* def UCHAR_MAX */
 149 # define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
 150 # ifdef _UNICOS                 /* Stupid cray bug */
 151 #  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
 152 # else
 153 #  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
 154 # endif                         /* UNICOS */
 155 #else
 156 # define SCM_CHAR_CODE_LIMIT 256L
 157 # define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
 158 # if (0 != ~0)
 159 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
 160 # else
 161 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
 162 # endif /*  (0 != ~0) */
 163 #endif /* def HAVE_LIMITS_H */
 164 \f
 165
 166 #ifdef STDC_HEADERS
 167 # include <stdlib.h>
 168 # ifdef AMIGA
 169 #  include <stddef.h>
 170 # endif /* def AMIGA */
 171 # define scm_sizet size_t
 172 #else
 173 # ifdef _SIZE_T
 174 #  define scm_sizet size_t
 175 # else
 176 #  define scm_sizet unsigned int
 177 # endif /* def _SIZE_T */
 178 #endif /* def STDC_HEADERS */
 179
 180 \f
 181
 182 #include "libguile/tags.h"
 183
 184 \f
 185 #ifdef vms
 186 # ifndef CHEAP_CONTINUATIONS
 187    typedef int jmp_buf[17];
 188    extern int setjump(jmp_buf env);
 189    extern int longjump(jmp_buf env, int ret);
 190 #  define setjmp setjump
 191 #  define longjmp longjump
 192 # else
 193 #  include <setjmp.h>
 194 # endif
 195 #else                           /* ndef vms */
 196 # ifdef _CRAY1
 197     typedef int jmp_buf[112];
 198     extern int setjump(jmp_buf env);
 199     extern int longjump(jmp_buf env, int ret);
 200 #  define setjmp setjump
 201 #  define longjmp longjump
 202 # else                          /* ndef _CRAY1 */
 203 #  include <setjmp.h>
 204 # endif                         /* ndef _CRAY1 */
 205 #endif                          /* ndef vms */
 206
 207 /* James Clark came up with this neat one instruction fix for
 208  * continuations on the SPARC.  It flushes the register windows so
 209  * that all the state of the process is contained in the stack.
 210  */
 211
 212 #ifdef sparc
 213 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 214 #else
 215 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 216 #endif
 217
 218 /* If stack is not longword aligned then
 219  */
 220
 221 /* #define SHORT_ALIGN */
 222 #ifdef THINK_C
 223 # define SHORT_ALIGN
 224 #endif
 225 #ifdef MSDOS
 226 # define SHORT_ALIGN
 227 #endif
 228 #ifdef atarist
 229 # define SHORT_ALIGN
 230 #endif
 231
 232 #ifdef SHORT_ALIGN
 233 typedef short SCM_STACKITEM;
 234 #else
 235 typedef long SCM_STACKITEM;
 236 #endif
 237 \f
 238
 239 #ifndef USE_THREADS
 240 #define SCM_THREAD_DEFER
 241 #define SCM_THREAD_ALLOW
 242 #define SCM_THREAD_REDEFER
 243 #define SCM_THREAD_REALLOW_1
 244 #define SCM_THREAD_REALLOW_2
 245 #define SCM_THREAD_SWITCHING_CODE
 246 #endif
 247
 248 extern unsigned int scm_async_clock;
 249
 250 #define SCM_ASYNC_TICK \
 251 do { \
 252   if (0 == --scm_async_clock) \
 253     scm_async_click (); \
 254 } while(0)
 255
 256 #ifdef SCM_CAREFUL_INTS
 257 #define SCM_CHECK_NOT_DISABLED \
 258   if (scm_ints_disabled) \
 259     fputs("ints already disabled\n", stderr); \
 260
 261 #define SCM_CHECK_NOT_ENABLED \
 262   if (!scm_ints_disabled) \
 263     fputs("ints already enabled\n", stderr); \
 264
 265 #else
 266 #define SCM_CHECK_NOT_DISABLED
 267 #define SCM_CHECK_NOT_ENABLED
 268 #endif
 269
 270
 271 /* Anthony Green writes:
 272    When the compiler sees...
 273            DEFER_INTS;
 274            [critical code here]
 275            ALLOW_INTS;
 276    ...it doesn't actually promise to keep the critical code within the
 277    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 278    schedule it outside of the magic defined in those macros.
 279
 280    However, GCC's volatile asm feature forms a barrier over which code is
 281    never moved. So if you add...
 282            asm ("");
 283    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 284    code will always remain in place.  asm's without inputs or outputs
 285    are implicitly volatile. */
 286 #ifdef __GNUC__
 287 #define SCM_FENCE asm /* volatile */ ("")
 288 #else
 289 #define SCM_FENCE
 290 #endif
 291
 292 #define SCM_DEFER_INTS \
 293 do { \
 294   SCM_FENCE; \
 295   SCM_CHECK_NOT_DISABLED; \
 296   SCM_THREAD_DEFER; \
 297   SCM_FENCE; \
 298   scm_ints_disabled = 1; \
 299   SCM_FENCE; \
 300 } while (0)
 301
 302
 303 #define SCM_ALLOW_INTS_ONLY \
 304 do { \
 305   SCM_THREAD_ALLOW; \
 306   scm_ints_disabled = 0; \
 307 } while (0)
 308
 309
 310 #define SCM_ALLOW_INTS \
 311 do { \
 312   SCM_FENCE; \
 313   SCM_CHECK_NOT_ENABLED; \
 314   SCM_THREAD_SWITCHING_CODE; \
 315   SCM_FENCE; \
 316   scm_ints_disabled = 0; \
 317   SCM_FENCE; \
 318   SCM_THREAD_ALLOW; \
 319   SCM_ASYNC_TICK; \
 320   SCM_FENCE; \
 321 } while (0)
 322
 323
 324 #define SCM_REDEFER_INTS  \
 325 do { \
 326   SCM_FENCE; \
 327   SCM_THREAD_REDEFER; \
 328   ++scm_ints_disabled; \
 329   SCM_FENCE; \
 330 } while (0)
 331
 332
 333 #define SCM_REALLOW_INTS \
 334 do { \
 335   SCM_FENCE; \
 336   SCM_THREAD_REALLOW_1; \
 337   SCM_THREAD_SWITCHING_CODE; \
 338   SCM_FENCE; \
 339   --scm_ints_disabled; \
 340   if (!scm_ints_disabled) \
 341     { \
 342       SCM_THREAD_REALLOW_2; \
 343       SCM_ASYNC_TICK; \
 344     } \
 345   SCM_FENCE; \
 346 } while (0)
 347
 348
 349 #define SCM_TICK \
 350 do { \
 351   SCM_DEFER_INTS; \
 352   SCM_ALLOW_INTS; \
 353 } while (0)
 354
 355 \f
 356
 357 /* Classification of critical sections
 358  *
 359  * When Guile moves to POSIX threads, it won't be possible to prevent
 360  * context switching.  In fact, the whole idea of context switching is
 361  * bogus if threads are run by different processors.  Therefore, we
 362  * must ultimately eliminate all critical sections or enforce them by
 363  * use of mutecis.
 364  *
 365  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 366  * be classified and replaced by one of the delimiters below.  If you
 367  * understand what this is all about, I'd like to encourage you to
 368  * help with this task.  The set of classes below must of course be
 369  * incrementally augmented.
 370  *
 371  * MDJ 980419 <djurfeldt@nada.kth.se>
 372  */
 373
 374 /* A sections
 375  *
 376  * Allocation of a cell with type tag in the CAR.
 377  *
 378  * With POSIX threads, each thread will have a private pool of free
 379  * cells.  Therefore, this type of section can be removed.  But!  It
 380  * is important that the CDR is initialized first (with the CAR still
 381  * indicating a free cell) so that we can guarantee a consistent heap
 382  * at all times.
 383  */
 384
 385 #ifdef SCM_POSIX_THREADS
 386 #define SCM_ENTER_A_SECTION
 387 #define SCM_EXIT_A_SECTION
 388 #else
 389 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 390 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 391 #endif
 392
 393 \f
 394
 395 /** SCM_ASSERT
 396  **
 397  **/
 398
 399
 400 #ifdef SCM_RECKLESS
 401 #define SCM_ASSERT(_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_ASRTGO(_cond, _label) \
 408         if (!(_cond)) \
 409           goto _label
 410 #endif
 411
 412 /*
 413  * SCM_WTA_DISPATCH
 414  */
 415
 416 extern SCM scm_call_generic_0 (SCM gf);
 417
 418 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 419   return ((gf) \
 420           ? scm_call_generic_0 ((gf)) \
 421           : scm_wta ((arg), (char *) (pos), (subr)))
 422 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 423   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (arg), (pos), (subr))
 424
 425 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 426
 427 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 428   return ((gf) \
 429           ? scm_call_generic_1 ((gf), (a1)) \
 430           : scm_wta ((a1), (char *) (pos), (subr)))
 431 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 432   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 433
 434 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 435
 436 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 437   return ((gf) \
 438           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 439           : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
 440 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 441   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 442
 443 extern SCM scm_apply_generic (SCM gf, SCM args);
 444
 445 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 446   return ((gf) \
 447           ? scm_apply_generic ((gf), (args)) \
 448           : scm_wta (scm_list_ref ((args), SCM_MAKINUM ((pos) - 1)), \
 449                      (char *) (pos), \
 450                      (subr)))
 451 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 452   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 453
 454 #ifndef SCM_MAGIC_SNARFER
 455 /* Let these macros pass through if
 456    we are snarfing;  thus we can tell the
 457    difference between the use of an actual
 458    number vs. the use of one of these macros --
 459    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 460    constructs must match the formal argument name,
 461    but using SCM_ARG* avoids the test */
 462
 463 #define SCM_ARGn                0
 464 #define SCM_ARG1                1
 465 #define SCM_ARG2                2
 466 #define SCM_ARG3                3
 467 #define SCM_ARG4                4
 468 #define SCM_ARG5                5
 469 #define SCM_ARG6                6
 470 #define SCM_ARG7                7
 471      /* #define SCM_ARGERR(X)           ((X) < SCM_WNA \
 472                                  ? (char *)(X) \
 473                                  : "wrong type argument")
 474                                  */
 475
 476 /* Following must match entry indexes in scm_errmsgs[].
 477  * Also, SCM_WNA must follow the last SCM_ARGn in sequence.
 478  */
 479 #define SCM_WNA                 8
 480      /* #define SCM_OVSCM_FLOW          9 */
 481 #define SCM_OUTOFRANGE          10
 482 #define SCM_NALLOC              11
 483      /* #define SCM_STACK_OVFLOW        12 */
 484      /* #define SCM_EXIT                13 */
 485
 486 #endif /* SCM_MAGIC_SNARFER */
 487
 488 /* (...still matching scm_errmsgs)  These
 489  * are signals.  Signals may become errors
 490  * but are distinguished because they first
 491  * try to invoke a handler that can resume
 492  * the interrupted routine.
 493  */
 494 #define SCM_HUP_SIGNAL          14
 495 #define SCM_INT_SIGNAL          15
 496 #define SCM_FPE_SIGNAL          16
 497 #define SCM_BUS_SIGNAL          17
 498 #define SCM_SEGV_SIGNAL         18
 499 #define SCM_ALRM_SIGNAL         19
 500 #define SCM_GC_SIGNAL           20
 501 #define SCM_TICK_SIGNAL         21
 502
 503 #define SCM_SIG_ORD(X)          ((X) - SCM_HUP_SIGNAL)
 504 #define SCM_ORD_SIG(X)          ((X) + SCM_HUP_SIGNAL)
 505 #define SCM_NUM_SIGS            (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 506
 507 #if 0
 508 struct errdesc
 509 {
 510   char *msg;
 511   char *s_response;
 512   short parent_err;
 513 };
 514
 515
 516 extern struct errdesc scm_errmsgs[];
 517 #endif
 518
 519 \f
 520
 521 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 522  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 523  * SCM if errors were encountered.  The return code can be explicitly
 524  * specified in a SCM program with (scm_quit <n>).
 525  */
 526
 527 #ifndef SCM_EXIT_SUCCESS
 528 #ifdef vms
 529 #define SCM_EXIT_SUCCESS 1
 530 #else
 531 #define SCM_EXIT_SUCCESS 0
 532 #endif /* def vms */
 533 #endif /* ndef SCM_EXIT_SUCCESS */
 534 #ifndef SCM_EXIT_FAILURE
 535 #ifdef vms
 536 #define SCM_EXIT_FAILURE 2
 537 #else
 538 #define SCM_EXIT_FAILURE 1
 539 #endif /* def vms */
 540 #endif /* ndef SCM_EXIT_FAILURE */
 541
 542
 543
 544 \f
 545
 546 #endif  /* __SCMH */