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 #undef SCM_CAREFUL_INTS
  88 \f
  89 /* {Unsupported Options}
  90  *
  91  * These must be defined as given here.
  92  */
  93
  94
  95 #define CCLO
  96
  97 /* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
  98    have horrible plans for their unification.  */
  99 #undef SICP
 100
 101 \f
 102
 103 /* Random options (not yet supported or in final form). */
 104
 105 #define STACK_CHECKING
 106 #undef NO_CEVAL_STACK_CHECKING
 107
 108 /* Some auto-generated .h files contain unused prototypes
 109  * that need these typedefs.
 110  */
 111 typedef long long long_long;
 112 typedef unsigned long long ulong_long;
 113
 114
 115 \f
 116 /* What did the configure script discover about the outside world?  */
 117 #include "libguile/scmconfig.h"
 118
 119 \f
 120 /* Write prototype declarations like this:
 121      int foo SCM_P ((int a, int b));
 122    At definitions, use K&R style declarations, but make sure there's a
 123    declarative prototype (as above) in scope.  This will give you
 124    argument type checking, when available, and be harmless otherwise.  */
 125 #ifdef __STDC__
 126 #  define SCM_P(x) x
 127 #else
 128 #  define SCM_P(x) ()
 129 #endif
 130
 131 \f
 132
 133 /* Define
 134  *
 135  * SCM_CHAR_CODE_LIMIT          == UCHAR_MAX + 1
 136  * SCM_MOST_POSITIVE_FIXNUM     (LONG_MAX>>2)
 137  * SCM_MOST_NEGATIVE_FIXNUM     == SCM_SRS((long)LONG_MIN, 2)
 138  */
 139
 140 #ifdef HAVE_LIMITS_H
 141 # include <limits.h>
 142 # ifdef UCHAR_MAX
 143 #  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
 144 # else
 145 #  define SCM_CHAR_CODE_LIMIT 256L
 146 # endif /* def UCHAR_MAX */
 147 # define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
 148 # ifdef _UNICOS                 /* Stupid cray bug */
 149 #  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
 150 # else
 151 #  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
 152 # endif                         /* UNICOS */
 153 #else
 154 # define SCM_CHAR_CODE_LIMIT 256L
 155 # define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
 156 # if (0 != ~0)
 157 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
 158 # else
 159 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
 160 # endif /*  (0 != ~0) */
 161 #endif /* def HAVE_LIMITS_H */
 162 \f
 163
 164 #ifdef STDC_HEADERS
 165 # include <stdlib.h>
 166 # ifdef AMIGA
 167 #  include <stddef.h>
 168 # endif /* def AMIGA */
 169 # define scm_sizet size_t
 170 #else
 171 # ifdef _SIZE_T
 172 #  define scm_sizet size_t
 173 # else
 174 #  define scm_sizet unsigned int
 175 # endif /* def _SIZE_T */
 176 #endif /* def STDC_HEADERS */
 177
 178 \f
 179
 180 #include "libguile/tags.h"
 181
 182 \f
 183 #ifdef vms
 184 # ifndef CHEAP_CONTINUATIONS
 185    typedef int jmp_buf[17];
 186    extern int setjump(jmp_buf env);
 187    extern int longjump(jmp_buf env, int ret);
 188 #  define setjmp setjump
 189 #  define longjmp longjump
 190 # else
 191 #  include <setjmp.h>
 192 # endif
 193 #else                           /* ndef vms */
 194 # ifdef _CRAY1
 195     typedef int jmp_buf[112];
 196     extern int setjump(jmp_buf env);
 197     extern int longjump(jmp_buf env, int ret);
 198 #  define setjmp setjump
 199 #  define longjmp longjump
 200 # else                          /* ndef _CRAY1 */
 201 #  include <setjmp.h>
 202 # endif                         /* ndef _CRAY1 */
 203 #endif                          /* ndef vms */
 204
 205 /* James Clark came up with this neat one instruction fix for
 206  * continuations on the SPARC.  It flushes the register windows so
 207  * that all the state of the process is contained in the stack.
 208  */
 209
 210 #ifdef sparc
 211 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 212 #else
 213 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 214 #endif
 215
 216 /* If stack is not longword aligned then
 217  */
 218
 219 /* #define SHORT_ALIGN */
 220 #ifdef THINK_C
 221 # define SHORT_ALIGN
 222 #endif
 223 #ifdef MSDOS
 224 # define SHORT_ALIGN
 225 #endif
 226 #ifdef atarist
 227 # define SHORT_ALIGN
 228 #endif
 229
 230 #ifdef SHORT_ALIGN
 231 typedef short SCM_STACKITEM;
 232 #else
 233 typedef long SCM_STACKITEM;
 234 #endif
 235 \f
 236
 237 #ifndef USE_THREADS
 238 #define SCM_THREAD_DEFER
 239 #define SCM_THREAD_ALLOW
 240 #define SCM_THREAD_REDEFER
 241 #define SCM_THREAD_REALLOW_1
 242 #define SCM_THREAD_REALLOW_2
 243 #define SCM_THREAD_SWITCHING_CODE
 244 #endif
 245
 246 extern unsigned int scm_async_clock;
 247
 248 #define SCM_ASYNC_TICK \
 249 do { \
 250   if (0 == --scm_async_clock) \
 251     scm_async_click (); \
 252 } while(0)
 253
 254 #ifdef SCM_CAREFUL_INTS
 255 #define SCM_CHECK_NOT_DISABLED \
 256   if (scm_ints_disabled) \
 257     fputs("ints already disabled\n", stderr); \
 258
 259 #define SCM_CHECK_NOT_ENABLED \
 260   if (!scm_ints_disabled) \
 261     fputs("ints already enabled\n", stderr); \
 262
 263 #else
 264 #define SCM_CHECK_NOT_DISABLED
 265 #define SCM_CHECK_NOT_ENABLED
 266 #endif
 267
 268
 269 /* Anthony Green writes:
 270    When the compiler sees...
 271            DEFER_INTS;
 272            [critical code here]
 273            ALLOW_INTS;
 274    ...it doesn't actually promise to keep the critical code within the
 275    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 276    schedule it outside of the magic defined in those macros.
 277
 278    However, GCC's volatile asm feature forms a barrier over which code is
 279    never moved. So if you add...
 280            asm ("");
 281    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 282    code will always remain in place.  asm's without inputs or outputs
 283    are implicitly volatile. */
 284 #ifdef __GNUC__
 285 #define SCM_FENCE asm /* volatile */ ("")
 286 #else
 287 #define SCM_FENCE
 288 #endif
 289
 290 #define SCM_DEFER_INTS \
 291 do { \
 292   SCM_FENCE; \
 293   SCM_CHECK_NOT_DISABLED; \
 294   SCM_THREAD_DEFER; \
 295   SCM_FENCE; \
 296   scm_ints_disabled = 1; \
 297   SCM_FENCE; \
 298 } while (0)
 299
 300
 301 #define SCM_ALLOW_INTS_ONLY \
 302 do { \
 303   SCM_THREAD_ALLOW; \
 304   scm_ints_disabled = 0; \
 305 } while (0)
 306
 307
 308 #define SCM_ALLOW_INTS \
 309 do { \
 310   SCM_FENCE; \
 311   SCM_CHECK_NOT_ENABLED; \
 312   SCM_THREAD_SWITCHING_CODE; \
 313   SCM_FENCE; \
 314   scm_ints_disabled = 0; \
 315   SCM_FENCE; \
 316   SCM_THREAD_ALLOW; \
 317   SCM_ASYNC_TICK; \
 318   SCM_FENCE; \
 319 } while (0)
 320
 321
 322 #define SCM_REDEFER_INTS  \
 323 do { \
 324   SCM_FENCE; \
 325   SCM_THREAD_REDEFER; \
 326   ++scm_ints_disabled; \
 327   SCM_FENCE; \
 328 } while (0)
 329
 330
 331 #define SCM_REALLOW_INTS \
 332 do { \
 333   SCM_FENCE; \
 334   SCM_THREAD_REALLOW_1; \
 335   SCM_THREAD_SWITCHING_CODE; \
 336   SCM_FENCE; \
 337   --scm_ints_disabled; \
 338   if (!scm_ints_disabled) \
 339     { \
 340       SCM_THREAD_REALLOW_2; \
 341       SCM_ASYNC_TICK; \
 342     } \
 343   SCM_FENCE; \
 344 } while (0)
 345
 346
 347 #define SCM_TICK \
 348 do { \
 349   SCM_DEFER_INTS; \
 350   SCM_ALLOW_INTS; \
 351 } while (0)
 352
 353 \f
 354
 355 /* Classification of critical sections
 356  *
 357  * When Guile moves to POSIX threads, it won't be possible to prevent
 358  * context switching.  In fact, the whole idea of context switching is
 359  * bogus if threads are run by different processors.  Therefore, we
 360  * must ultimately eliminate all critical sections or enforce them by
 361  * use of mutecis.
 362  *
 363  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 364  * be classified and replaced by one of the delimiters below.  If you
 365  * understand what this is all about, I'd like to encourage you to
 366  * help with this task.  The set of classes below must of course be
 367  * incrementally augmented.
 368  *
 369  * MDJ 980419 <djurfeldt@nada.kth.se>
 370  */
 371
 372 /* A sections
 373  *
 374  * Allocation of a cell with type tag in the CAR.
 375  *
 376  * With POSIX threads, each thread will have a private pool of free
 377  * cells.  Therefore, this type of section can be removed.  But!  It
 378  * is important that the CDR is initialized first (with the CAR still
 379  * indicating a free cell) so that we can guarantee a consistent heap
 380  * at all times.
 381  */
 382
 383 #ifdef SCM_POSIX_THREADS
 384 #define SCM_ENTER_A_SECTION
 385 #define SCM_EXIT_A_SECTION
 386 #else
 387 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 388 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 389 #endif
 390
 391 \f
 392
 393 /** SCM_ASSERT
 394  **
 395  **/
 396
 397
 398 #ifdef SCM_RECKLESS
 399 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 400 #define SCM_ASRTGO(_cond, _label)
 401 #else
 402 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 403         if (!(_cond)) \
 404           scm_wta(_arg, (char *)(_pos), _subr)
 405 #define SCM_ASRTGO(_cond, _label) \
 406         if (!(_cond)) \
 407           goto _label
 408 #endif
 409
 410 /*
 411  * SCM_WTA_DISPATCH
 412  */
 413
 414 extern SCM scm_call_generic_0 (SCM gf);
 415
 416 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 417   return ((gf) \
 418           ? scm_call_generic_0 ((gf)) \
 419           : scm_wta ((arg), (char *) (pos), (subr)))
 420 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 421   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (arg), (pos), (subr))
 422
 423 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 424
 425 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 426   return ((gf) \
 427           ? scm_call_generic_1 ((gf), (a1)) \
 428           : scm_wta ((a1), (char *) (pos), (subr)))
 429 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 430   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 431
 432 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 433
 434 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 435   return ((gf) \
 436           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 437           : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
 438 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 439   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 440
 441 extern SCM scm_apply_generic (SCM gf, SCM args);
 442
 443 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 444   return ((gf) \
 445           ? scm_apply_generic ((gf), (args)) \
 446           : scm_wta (scm_list_ref ((args), SCM_MAKINUM ((pos) - 1)), \
 447                      (char *) (pos), \
 448                      (subr)))
 449 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 450   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 451
 452 #ifndef SCM_MAGIC_SNARFER
 453 /* Let these macros pass through if
 454    we are snarfing;  thus we can tell the
 455    difference between the use of an actual
 456    number vs. the use of one of these macros --
 457    actual numbers in SCM_VALIDATE_*/SCM_ASSERT
 458    constructs must match the formal argument name,
 459    but using SCM_ARG* avoids the test */
 460
 461 #define SCM_ARGn                0
 462 #define SCM_ARG1                1
 463 #define SCM_ARG2                2
 464 #define SCM_ARG3                3
 465 #define SCM_ARG4                4
 466 #define SCM_ARG5                5
 467 #define SCM_ARG6                6
 468 #define SCM_ARG7                7
 469      /* #define SCM_ARGERR(X)           ((X) < SCM_WNA \
 470                                  ? (char *)(X) \
 471                                  : "wrong type argument")
 472                                  */
 473
 474 /* Following must match entry indexes in scm_errmsgs[].
 475  * Also, SCM_WNA must follow the last SCM_ARGn in sequence.
 476  */
 477 #define SCM_WNA                 8
 478      /* #define SCM_OVSCM_FLOW          9 */
 479 #define SCM_OUTOFRANGE          10
 480 #define SCM_NALLOC              11
 481      /* #define SCM_STACK_OVFLOW        12 */
 482      /* #define SCM_EXIT                13 */
 483
 484 #endif /* SCM_MAGIC_SNARFER */
 485
 486 /* (...still matching scm_errmsgs)  These
 487  * are signals.  Signals may become errors
 488  * but are distinguished because they first
 489  * try to invoke a handler that can resume
 490  * the interrupted routine.
 491  */
 492 #define SCM_HUP_SIGNAL          14
 493 #define SCM_INT_SIGNAL          15
 494 #define SCM_FPE_SIGNAL          16
 495 #define SCM_BUS_SIGNAL          17
 496 #define SCM_SEGV_SIGNAL         18
 497 #define SCM_ALRM_SIGNAL         19
 498 #define SCM_GC_SIGNAL           20
 499 #define SCM_TICK_SIGNAL         21
 500
 501 #define SCM_SIG_ORD(X)          ((X) - SCM_HUP_SIGNAL)
 502 #define SCM_ORD_SIG(X)          ((X) + SCM_HUP_SIGNAL)
 503 #define SCM_NUM_SIGS            (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 504
 505 #if 0
 506 struct errdesc
 507 {
 508   char *msg;
 509   char *s_response;
 510   short parent_err;
 511 };
 512
 513
 514 extern struct errdesc scm_errmsgs[];
 515 #endif
 516
 517 \f
 518
 519 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 520  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 521  * SCM if errors were encountered.  The return code can be explicitly
 522  * specified in a SCM program with (scm_quit <n>).
 523  */
 524
 525 #ifndef SCM_EXIT_SUCCESS
 526 #ifdef vms
 527 #define SCM_EXIT_SUCCESS 1
 528 #else
 529 #define SCM_EXIT_SUCCESS 0
 530 #endif /* def vms */
 531 #endif /* ndef SCM_EXIT_SUCCESS */
 532 #ifndef SCM_EXIT_FAILURE
 533 #ifdef vms
 534 #define SCM_EXIT_FAILURE 2
 535 #else
 536 #define SCM_EXIT_FAILURE 1
 537 #endif /* def vms */
 538 #endif /* ndef SCM_EXIT_FAILURE */
 539
 540
 541
 542 \f
 543
 544 #endif  /* __SCMH */