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
  47 /* "What's the difference between _scm.h and __scm.h?"
  48
  49    _scm.h is not installed; it's only visible to the libguile sources
  50    themselves.
  51
  52    __scm.h is installed, and is #included by <libguile.h>.  If both
  53    the client and libguile need some piece of information, and it
  54    doesn't fit well into the header file for any particular module, it
  55    should go in __scm.h.  */
  56
  57
  58 /* {Supported Options}
  59  *
  60  * These may be defined or undefined.
  61  */
  62
  63 /* Old async mechanism */
  64 /* #define GUILE_OLD_ASYNC_CLICK */
  65
  66 /* New scheme for garbage collection */
  67 #define GUILE_NEW_GC_SCHEME
  68
  69 /* #define GUILE_DEBUG_FREELIST */
  70
  71 /* If the compile FLAG `SCM_CAUTIOUS' is #defined then the number of
  72  * arguments is always checked for application of closures.  If the
  73  * compile FLAG `SCM_RECKLESS' is #defined then they are not checked.
  74  * Otherwise, number of argument checks for closures are made only when
  75  * the function position (whose value is the closure) of a combination is
  76  * not an ILOC or GLOC.  When the function position of a combination is a
  77  * symbol it will be checked only the first time it is evaluated because
  78  * it will then be replaced with an ILOC or GLOC.
  79  */
  80 #undef SCM_RECKLESS
  81 #define SCM_CAUTIOUS
  82
  83 /* After looking up a local for the first time, rewrite the
  84  * code graph, caching its position.
  85  */
  86 #define MEMOIZE_LOCALS
  87
  88 /* All the number support there is.
  89  */
  90 #define BIGNUMS
  91
  92 /* GC should relinquish empty cons-pair arenas.
  93  */
  94 #ifndef GUILE_NEW_GC_SCHEME
  95 #define GC_FREE_SEGMENTS
  96 #endif
  97
  98 /* Provide a scheme-accessible count-down timer that
  99  * generates a pseudo-interrupt.
 100  */
 101 #define TICKS
 102
 103
 104 /* Use engineering notation when converting numbers strings?
 105  */
 106 #undef ENGNOT
 107
 108 #undef SCM_CAREFUL_INTS
 109 \f
 110 /* {Unsupported Options}
 111  *
 112  * These must be defined as given here.
 113  */
 114
 115
 116 #define CCLO
 117
 118 /* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
 119    have horrible plans for their unification.  */
 120 #undef SICP
 121
 122 \f
 123
 124 /* Random options (not yet supported or in final form). */
 125
 126 #define STACK_CHECKING
 127 #undef NO_CEVAL_STACK_CHECKING
 128
 129 \f
 130
 131 /* What did the configure script discover about the outside world?  */
 132 #include "libguile/scmconfig.h"
 133
 134 \f
 135
 136 /* {Debugging Options}
 137  *
 138  * These compile time options determine whether to include code that is only
 139  * useful for debugging guile itself or C level extensions to guile.  The
 140  * common prefix for all option macros of this kind is "SCM_DEBUG_".  It is
 141  * guaranteed that a macro named SCM_DEBUG_XXX is defined to be either 0 or 1,
 142  * i. e. there is no need to test for the undefined case.  This allows to use
 143  * these definitions comfortably in macro code, as in the following example:
 144  *   #define FOO do { if (SCM_DEBUG_XXX) bar(); else baz(); } while (0)
 145  * Any sane compiler will remove the unused branch without any performance
 146  * penalty for the resulting code.
 147  *
 148  * Note:  Some SCM_DEBUG_XXX options are not settable at configure time.
 149  * To change the value of such options you will have to edit this header
 150  * file or give -DSCM_DEBUG_XXX options to make.
 151  */
 152
 153
 154 /* If SCM_DEBUG_DEPRECATED is set to 1, deprecated code is not compiled.  This
 155  * can be used by developers to get rid of references to deprecated code.
 156  */
 157 #ifndef SCM_DEBUG_DEPRECATED
 158 #define SCM_DEBUG_DEPRECATED 0
 159 #endif
 160
 161 \f
 162
 163 #ifdef HAVE_LONG_LONGS
 164
 165 /* Some auto-generated .h files contain unused prototypes
 166  * that need these typedefs.
 167  */
 168 typedef long long long_long;
 169 typedef unsigned long long ulong_long;
 170
 171 #endif /* HAVE_LONG_LONGS */
 172
 173 \f
 174
 175 /* Define
 176  *
 177  * SCM_CHAR_CODE_LIMIT          == UCHAR_MAX + 1
 178  * SCM_MOST_POSITIVE_FIXNUM     (LONG_MAX>>2)
 179  * SCM_MOST_NEGATIVE_FIXNUM     == SCM_SRS((long)LONG_MIN, 2)
 180  */
 181
 182 #ifdef HAVE_LIMITS_H
 183 # include <limits.h>
 184 # ifdef UCHAR_MAX
 185 #  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
 186 # else
 187 #  define SCM_CHAR_CODE_LIMIT 256L
 188 # endif /* def UCHAR_MAX */
 189 # define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
 190 # ifdef _UNICOS                 /* Stupid cray bug */
 191 #  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
 192 # else
 193 #  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
 194 # endif                         /* UNICOS */
 195 #else
 196 # define SCM_CHAR_CODE_LIMIT 256L
 197 # define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
 198 # if (0 != ~0)
 199 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
 200 # else
 201 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
 202 # endif /*  (0 != ~0) */
 203 #endif /* def HAVE_LIMITS_H */
 204 \f
 205
 206 #ifdef STDC_HEADERS
 207 # include <stdlib.h>
 208 # ifdef AMIGA
 209 #  include <stddef.h>
 210 # endif /* def AMIGA */
 211 # define scm_sizet size_t
 212 #else
 213 # ifdef _SIZE_T
 214 #  define scm_sizet size_t
 215 # else
 216 #  define scm_sizet unsigned int
 217 # endif /* def _SIZE_T */
 218 #endif /* def STDC_HEADERS */
 219
 220 \f
 221
 222 #include "libguile/tags.h"
 223
 224 \f
 225 #ifdef vms
 226 # ifndef CHEAP_CONTINUATIONS
 227    typedef int jmp_buf[17];
 228    extern int setjump(jmp_buf env);
 229    extern int longjump(jmp_buf env, int ret);
 230 #  define setjmp setjump
 231 #  define longjmp longjump
 232 # else
 233 #  include <setjmp.h>
 234 # endif
 235 #else                           /* ndef vms */
 236 # ifdef _CRAY1
 237     typedef int jmp_buf[112];
 238     extern int setjump(jmp_buf env);
 239     extern int longjump(jmp_buf env, int ret);
 240 #  define setjmp setjump
 241 #  define longjmp longjump
 242 # else                          /* ndef _CRAY1 */
 243 #  include <setjmp.h>
 244 # endif                         /* ndef _CRAY1 */
 245 #endif                          /* ndef vms */
 246
 247 /* James Clark came up with this neat one instruction fix for
 248  * continuations on the SPARC.  It flushes the register windows so
 249  * that all the state of the process is contained in the stack.
 250  */
 251
 252 #ifdef sparc
 253 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 254 #else
 255 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 256 #endif
 257
 258 /* If stack is not longword aligned then
 259  */
 260
 261 /* #define SHORT_ALIGN */
 262 #ifdef THINK_C
 263 # define SHORT_ALIGN
 264 #endif
 265 #ifdef MSDOS
 266 # define SHORT_ALIGN
 267 #endif
 268 #ifdef atarist
 269 # define SHORT_ALIGN
 270 #endif
 271
 272 #ifdef SHORT_ALIGN
 273 typedef short SCM_STACKITEM;
 274 #else
 275 typedef long SCM_STACKITEM;
 276 #endif
 277 \f
 278
 279 #ifndef USE_THREADS
 280 #define SCM_THREAD_DEFER
 281 #define SCM_THREAD_ALLOW
 282 #define SCM_THREAD_REDEFER
 283 #define SCM_THREAD_SWITCHING_CODE
 284 #endif
 285
 286 #ifdef GUILE_OLD_ASYNC_CLICK
 287 extern unsigned int scm_async_clock;
 288
 289 #define SCM_ASYNC_TICK \
 290 do { \
 291   if (0 == --scm_async_clock) \
 292     scm_async_click (); \
 293 } while(0)
 294 #else
 295 extern int scm_asyncs_pending_p;
 296
 297 #define SCM_ASYNC_TICK /*fixme* should change names */ \
 298 do { \
 299   if (scm_asyncs_pending_p) \
 300     scm_async_click (); \
 301 } while (0)
 302 #endif
 303
 304 #ifdef SCM_CAREFUL_INTS
 305 #define SCM_CHECK_NOT_DISABLED \
 306   if (scm_ints_disabled) \
 307     fputs("ints already disabled\n", stderr); \
 308
 309 #define SCM_CHECK_NOT_ENABLED \
 310   if (!scm_ints_disabled) \
 311     fputs("ints already enabled\n", stderr); \
 312
 313 #else
 314 #define SCM_CHECK_NOT_DISABLED
 315 #define SCM_CHECK_NOT_ENABLED
 316 #endif
 317
 318
 319 /* Anthony Green writes:
 320    When the compiler sees...
 321            DEFER_INTS;
 322            [critical code here]
 323            ALLOW_INTS;
 324    ...it doesn't actually promise to keep the critical code within the
 325    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 326    schedule it outside of the magic defined in those macros.
 327
 328    However, GCC's volatile asm feature forms a barrier over which code is
 329    never moved. So if you add...
 330            asm ("");
 331    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 332    code will always remain in place.  asm's without inputs or outputs
 333    are implicitly volatile. */
 334 #ifdef __GNUC__
 335 #define SCM_FENCE asm /* volatile */ ("")
 336 #else
 337 #define SCM_FENCE
 338 #endif
 339
 340 #define SCM_DEFER_INTS \
 341 do { \
 342   SCM_FENCE; \
 343   SCM_CHECK_NOT_DISABLED; \
 344   SCM_THREAD_DEFER; \
 345   SCM_FENCE; \
 346   scm_ints_disabled = 1; \
 347   SCM_FENCE; \
 348 } while (0)
 349
 350
 351 #define SCM_ALLOW_INTS_ONLY \
 352 do { \
 353   SCM_THREAD_ALLOW; \
 354   scm_ints_disabled = 0; \
 355 } while (0)
 356
 357
 358 #define SCM_ALLOW_INTS \
 359 do { \
 360   SCM_FENCE; \
 361   SCM_CHECK_NOT_ENABLED; \
 362   SCM_THREAD_SWITCHING_CODE; \
 363   SCM_FENCE; \
 364   scm_ints_disabled = 0; \
 365   SCM_FENCE; \
 366   SCM_THREAD_ALLOW; \
 367   SCM_FENCE; \
 368 } while (0)
 369
 370
 371 #define SCM_REDEFER_INTS  \
 372 do { \
 373   SCM_FENCE; \
 374   SCM_THREAD_REDEFER; \
 375   ++scm_ints_disabled; \
 376   SCM_FENCE; \
 377 } while (0)
 378
 379
 380 #define SCM_REALLOW_INTS \
 381 do { \
 382   SCM_FENCE; \
 383   SCM_THREAD_SWITCHING_CODE; \
 384   SCM_FENCE; \
 385   --scm_ints_disabled; \
 386   SCM_FENCE; \
 387 } while (0)
 388
 389
 390 #define SCM_TICK \
 391 do { \
 392   SCM_DEFER_INTS; \
 393   SCM_ALLOW_INTS; \
 394   SCM_ASYNC_TICK; \
 395 } while (0)
 396
 397 \f
 398
 399 /* Classification of critical sections
 400  *
 401  * When Guile moves to POSIX threads, it won't be possible to prevent
 402  * context switching.  In fact, the whole idea of context switching is
 403  * bogus if threads are run by different processors.  Therefore, we
 404  * must ultimately eliminate all critical sections or enforce them by
 405  * use of mutecis.
 406  *
 407  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 408  * be classified and replaced by one of the delimiters below.  If you
 409  * understand what this is all about, I'd like to encourage you to
 410  * help with this task.  The set of classes below must of course be
 411  * incrementally augmented.
 412  *
 413  * MDJ 980419 <djurfeldt@nada.kth.se>
 414  */
 415
 416 /* A sections
 417  *
 418  * Allocation of a cell with type tag in the CAR.
 419  *
 420  * With POSIX threads, each thread will have a private pool of free
 421  * cells.  Therefore, this type of section can be removed.  But!  It
 422  * is important that the CDR is initialized first (with the CAR still
 423  * indicating a free cell) so that we can guarantee a consistent heap
 424  * at all times.
 425  */
 426
 427 #ifdef SCM_POSIX_THREADS
 428 #define SCM_ENTER_A_SECTION
 429 #define SCM_EXIT_A_SECTION
 430 #else
 431 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 432 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 433 #endif
 434
 435 \f
 436
 437 /** SCM_ASSERT
 438  **
 439  **/
 440
 441
 442 #ifdef SCM_RECKLESS
 443 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 444 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr)
 445 #define SCM_ASRTGO(_cond, _label)
 446 #else
 447 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 448         if (!(_cond)) \
 449           scm_wta(_arg, (char *)(_pos), _subr)
 450 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg) \
 451         if (!(_cond)) \
 452           scm_wrong_type_arg_msg(_subr, _pos, _arg, _msg)
 453 #define SCM_ASRTGO(_cond, _label) \
 454         if (!(_cond)) \
 455           goto _label
 456 #endif
 457
 458 /*
 459  * SCM_WTA_DISPATCH
 460  */
 461
 462 /* Dirk:FIXME:: In all of the SCM_WTA_DISPATCH_* macros it is assumed that
 463  * 'gf' is zero if uninitialized.  It would be cleaner if some valid SCM value
 464  * like SCM_BOOL_F or SCM_UNDEFINED was chosen.
 465  */
 466
 467 extern SCM scm_call_generic_0 (SCM gf);
 468
 469 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 470   return (SCM_UNPACK (gf) \
 471           ? scm_call_generic_0 ((gf)) \
 472           : scm_wta ((arg), (char *) (pos), (subr)))
 473 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 474   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (arg), (pos), (subr))
 475
 476 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 477
 478 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 479   return (SCM_UNPACK (gf) \
 480           ? scm_call_generic_1 ((gf), (a1)) \
 481           : scm_wta ((a1), (char *) (pos), (subr)))
 482 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 483   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 484
 485 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 486
 487 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 488   return (SCM_UNPACK (gf) \
 489           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 490           : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
 491 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 492   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 493
 494 extern SCM scm_apply_generic (SCM gf, SCM args);
 495
 496 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 497   return (SCM_UNPACK (gf) \
 498           ? scm_apply_generic ((gf), (args)) \
 499           : scm_wta (scm_list_ref ((args), SCM_MAKINUM ((pos) - 1)), \
 500                      (char *) (pos), \
 501                      (subr)))
 502 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 503   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 504
 505 #ifndef SCM_MAGIC_SNARFER
 506 /* Let these macros pass through if
 507    we are snarfing;  thus we can tell the
 508    difference between the use of an actual
 509    number vs. the use of one of these macros --
 510    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 511    constructs must match the formal argument name,
 512    but using SCM_ARG* avoids the test */
 513
 514 #define SCM_ARGn                0
 515 #define SCM_ARG1                1
 516 #define SCM_ARG2                2
 517 #define SCM_ARG3                3
 518 #define SCM_ARG4                4
 519 #define SCM_ARG5                5
 520 #define SCM_ARG6                6
 521 #define SCM_ARG7                7
 522      /* #define SCM_ARGERR(X)           ((X) < SCM_WNA \
 523                                  ? (char *)(X) \
 524                                  : "wrong type argument")
 525                                  */
 526
 527 /* Following must match entry indexes in scm_errmsgs[].
 528  * Also, SCM_WNA must follow the last SCM_ARGn in sequence.
 529  */
 530 #define SCM_WNA                 8
 531      /* #define SCM_OVSCM_FLOW          9 */
 532 #define SCM_OUTOFRANGE          10
 533 #define SCM_NALLOC              11
 534      /* #define SCM_STACK_OVFLOW        12 */
 535      /* #define SCM_EXIT                13 */
 536
 537 #endif /* SCM_MAGIC_SNARFER */
 538
 539 /* (...still matching scm_errmsgs)  These
 540  * are signals.  Signals may become errors
 541  * but are distinguished because they first
 542  * try to invoke a handler that can resume
 543  * the interrupted routine.
 544  */
 545 #define SCM_HUP_SIGNAL          14
 546 #define SCM_INT_SIGNAL          15
 547 #define SCM_FPE_SIGNAL          16
 548 #define SCM_BUS_SIGNAL          17
 549 #define SCM_SEGV_SIGNAL         18
 550 #define SCM_ALRM_SIGNAL         19
 551 #define SCM_GC_SIGNAL           20
 552 #define SCM_TICK_SIGNAL         21
 553
 554 #define SCM_SIG_ORD(X)          ((X) - SCM_HUP_SIGNAL)
 555 #define SCM_ORD_SIG(X)          ((X) + SCM_HUP_SIGNAL)
 556 #define SCM_NUM_SIGS            (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 557
 558 #if 0
 559 struct errdesc
 560 {
 561   char *msg;
 562   char *s_response;
 563   short parent_err;
 564 };
 565
 566
 567 extern struct errdesc scm_errmsgs[];
 568 #endif
 569
 570 \f
 571
 572 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 573  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 574  * SCM if errors were encountered.  The return code can be explicitly
 575  * specified in a SCM program with (scm_quit <n>).
 576  */
 577
 578 #ifndef SCM_EXIT_SUCCESS
 579 #ifdef vms
 580 #define SCM_EXIT_SUCCESS 1
 581 #else
 582 #define SCM_EXIT_SUCCESS 0
 583 #endif /* def vms */
 584 #endif /* ndef SCM_EXIT_SUCCESS */
 585 #ifndef SCM_EXIT_FAILURE
 586 #ifdef vms
 587 #define SCM_EXIT_FAILURE 2
 588 #else
 589 #define SCM_EXIT_FAILURE 1
 590 #endif /* def vms */
 591 #endif /* ndef SCM_EXIT_FAILURE */
 592
 593
 594
 595 \f
 596
 597 #endif  /* __SCMH */
 598
 599 /*
 600   Local Variables:
 601   c-file-style: "gnu"
 602   End:
 603 */