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 /* #define GUILE_DEBUG_FREELIST */
  67
  68 /* If the compile FLAG `SCM_CAUTIOUS' is #defined then the number of
  69  * arguments is always checked for application of closures.  If the
  70  * compile FLAG `SCM_RECKLESS' is #defined then they are not checked.
  71  * Otherwise, number of argument checks for closures are made only when
  72  * the function position (whose value is the closure) of a combination is
  73  * not an ILOC or GLOC.  When the function position of a combination is a
  74  * symbol it will be checked only the first time it is evaluated because
  75  * it will then be replaced with an ILOC or GLOC.
  76  */
  77 #undef SCM_RECKLESS
  78 #define SCM_CAUTIOUS
  79
  80 /* After looking up a local for the first time, rewrite the
  81  * code graph, caching its position.
  82  */
  83 #define MEMOIZE_LOCALS
  84
  85 /* All the number support there is.
  86  */
  87 #define BIGNUMS
  88
  89 /* GC should relinquish empty cons-pair arenas. */
  90 /* cmm:FIXME look at this after done mangling the GC */
  91 /* #define GC_FREE_SEGMENTS */
  92
  93 /* Provide a scheme-accessible count-down timer that
  94  * generates a pseudo-interrupt.
  95  */
  96 #define TICKS
  97
  98
  99 /* Use engineering notation when converting numbers strings?
 100  */
 101 #undef ENGNOT
 102
 103 #undef SCM_CAREFUL_INTS
 104 \f
 105 /* {Unsupported Options}
 106  *
 107  * These must be defined as given here.
 108  */
 109
 110
 111 #define CCLO
 112
 113 /* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
 114    have horrible plans for their unification.  */
 115 #undef SICP
 116
 117 \f
 118
 119 /* Random options (not yet supported or in final form). */
 120
 121 #define STACK_CHECKING
 122 #undef NO_CEVAL_STACK_CHECKING
 123
 124 \f
 125
 126 /* What did the configure script discover about the outside world?  */
 127 #include "libguile/scmconfig.h"
 128
 129 \f
 130
 131 /* {Debugging Options}
 132  *
 133  * These compile time options determine whether to include code that is only
 134  * useful for debugging guile itself or C level extensions to guile.  The
 135  * common prefix for all option macros of this kind is "SCM_DEBUG_".  It is
 136  * guaranteed that a macro named SCM_DEBUG_XXX is defined to be either 0 or 1,
 137  * i. e. there is no need to test for the undefined case.  This allows to use
 138  * these definitions comfortably in macro code, as in the following example:
 139  *   #define FOO do { if (SCM_DEBUG_XXX) bar(); else baz(); } while (0)
 140  * Any sane compiler will remove the unused branch without any performance
 141  * penalty for the resulting code.
 142  *
 143  * Note:  Some SCM_DEBUG_XXX options are not settable at configure time.
 144  * To change the value of such options you will have to edit this header
 145  * file or give suitable options to make, like:
 146  *   make all CFLAGS="-DSCM_DEBUG_XXX=1 ..."
 147  */
 148
 149
 150 /* The value of SCM_DEBUG determines the default for most of the not yet
 151  * defined debugging options.  This allows, for example, to enable most of the
 152  * debugging options by simply defining SCM_DEBUG as 1.
 153  */
 154 #ifndef SCM_DEBUG
 155 #define SCM_DEBUG 0
 156 #endif
 157
 158 /* If SCM_DEBUG_CELL_ACCESSES is set to 1, cell accesses will perform
 159  * exhaustive parameter checking:  It will be verified that cell parameters
 160  * actually point to a valid heap cell.  Note:  If this option is enabled,
 161  * guile will run about ten times slower than normally.
 162  */
 163 #ifndef SCM_DEBUG_CELL_ACCESSES
 164 #define SCM_DEBUG_CELL_ACCESSES SCM_DEBUG
 165 #endif
 166
 167 /* If SCM_DEBUG_DEPRECATED is set to 1, deprecated code is not compiled.  This
 168  * can be used by developers to get rid of references to deprecated code.
 169  */
 170 #ifndef SCM_DEBUG_DEPRECATED
 171 #define SCM_DEBUG_DEPRECATED SCM_DEBUG
 172 #endif
 173
 174 /* If SCM_DEBUG_REST_ARGUMENT is set to 1, functions that take rest arguments
 175  * will check whether the rest arguments are actually passed as a proper list.
 176  * Otherwise, if SCM_DEBUG_REST_ARGUMENT is 0, functions that take rest
 177  * arguments will take it for granted that these are passed as a proper list.
 178  */
 179 #ifndef SCM_DEBUG_REST_ARGUMENT
 180 #define SCM_DEBUG_REST_ARGUMENT SCM_DEBUG
 181 #endif
 182
 183 /* Use this for _compile time_ type checking only, since the compiled result
 184  * will be quite inefficient.  The right way to make use of this option is to
 185  * do a 'make clean; make CFLAGS=-DSCM_DEBUG_TYPING_STRICTNESS=1', fix your
 186  * errors, and then do 'make clean; make'.
 187  */
 188 #ifndef SCM_DEBUG_TYPING_STRICTNESS
 189 #define SCM_DEBUG_TYPING_STRICTNESS 0
 190 #endif
 191
 192 \f
 193
 194 #ifdef HAVE_LONG_LONGS
 195
 196 /* Some auto-generated .h files contain unused prototypes
 197  * that need these typedefs.
 198  */
 199 typedef long long long_long;
 200 typedef unsigned long long ulong_long;
 201
 202 #endif /* HAVE_LONG_LONGS */
 203
 204 \f
 205
 206 /* Define
 207  *
 208  * SCM_CHAR_CODE_LIMIT          == UCHAR_MAX + 1
 209  * SCM_MOST_POSITIVE_FIXNUM     (LONG_MAX>>2)
 210  * SCM_MOST_NEGATIVE_FIXNUM     == SCM_SRS((long)LONG_MIN, 2)
 211  */
 212
 213 #ifdef HAVE_LIMITS_H
 214 # include <limits.h>
 215 # ifdef UCHAR_MAX
 216 #  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
 217 # else
 218 #  define SCM_CHAR_CODE_LIMIT 256L
 219 # endif /* def UCHAR_MAX */
 220 # define SCM_FIXNUM_BIT (LONG_BIT - 2)
 221 # define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
 222 # ifdef _UNICOS                 /* Stupid cray bug */
 223 #  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
 224 # else
 225 #  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
 226 # endif                         /* UNICOS */
 227 #else
 228 # define SCM_CHAR_CODE_LIMIT 256L
 229 # define SCM_FIXNUM_BIT 30
 230 # define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
 231 # if (0 != ~0)
 232 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
 233 # else
 234 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
 235 # endif /*  (0 != ~0) */
 236 #endif /* def HAVE_LIMITS_H */
 237 \f
 238
 239 #ifdef STDC_HEADERS
 240 # include <stdlib.h>
 241 # ifdef AMIGA
 242 #  include <stddef.h>
 243 # endif /* def AMIGA */
 244 # define scm_sizet size_t
 245 #else
 246 # ifdef _SIZE_T
 247 #  define scm_sizet size_t
 248 # else
 249 #  define scm_sizet unsigned int
 250 # endif /* def _SIZE_T */
 251 #endif /* def STDC_HEADERS */
 252
 253 \f
 254
 255 #include "libguile/tags.h"
 256
 257 \f
 258 #ifdef vms
 259 # ifndef CHEAP_CONTINUATIONS
 260    typedef int jmp_buf[17];
 261    extern int setjump(jmp_buf env);
 262    extern int longjump(jmp_buf env, int ret);
 263 #  define setjmp setjump
 264 #  define longjmp longjump
 265 # else
 266 #  include <setjmp.h>
 267 # endif
 268 #else                           /* ndef vms */
 269 # ifdef _CRAY1
 270     typedef int jmp_buf[112];
 271     extern int setjump(jmp_buf env);
 272     extern int longjump(jmp_buf env, int ret);
 273 #  define setjmp setjump
 274 #  define longjmp longjump
 275 # else                          /* ndef _CRAY1 */
 276 #  include <setjmp.h>
 277 # endif                         /* ndef _CRAY1 */
 278 #endif                          /* ndef vms */
 279
 280 /* James Clark came up with this neat one instruction fix for
 281  * continuations on the SPARC.  It flushes the register windows so
 282  * that all the state of the process is contained in the stack.
 283  */
 284
 285 #ifdef sparc
 286 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 287 #else
 288 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 289 #endif
 290
 291 /* If stack is not longword aligned then
 292  */
 293
 294 /* #define SHORT_ALIGN */
 295 #ifdef THINK_C
 296 # define SHORT_ALIGN
 297 #endif
 298 #ifdef MSDOS
 299 # define SHORT_ALIGN
 300 #endif
 301 #ifdef atarist
 302 # define SHORT_ALIGN
 303 #endif
 304
 305 #ifdef SHORT_ALIGN
 306 typedef short SCM_STACKITEM;
 307 #else
 308 typedef long SCM_STACKITEM;
 309 #endif
 310 \f
 311
 312 #ifndef USE_THREADS
 313 #define SCM_THREAD_DEFER
 314 #define SCM_THREAD_ALLOW
 315 #define SCM_THREAD_REDEFER
 316 #define SCM_THREAD_SWITCHING_CODE
 317 #endif
 318
 319 #ifdef GUILE_OLD_ASYNC_CLICK
 320 extern unsigned int scm_async_clock;
 321
 322 #define SCM_ASYNC_TICK \
 323 do { \
 324   if (0 == --scm_async_clock) \
 325     scm_async_click (); \
 326 } while(0)
 327 #else
 328 extern int scm_asyncs_pending_p;
 329
 330 #define SCM_ASYNC_TICK /*fixme* should change names */ \
 331 do { \
 332   if (scm_asyncs_pending_p) \
 333     scm_async_click (); \
 334 } while (0)
 335 #endif
 336
 337 #ifdef SCM_CAREFUL_INTS
 338 #define SCM_CHECK_NOT_DISABLED \
 339   if (scm_ints_disabled) \
 340     fputs("ints already disabled\n", stderr); \
 341
 342 #define SCM_CHECK_NOT_ENABLED \
 343   if (!scm_ints_disabled) \
 344     fputs("ints already enabled\n", stderr); \
 345
 346 #else
 347 #define SCM_CHECK_NOT_DISABLED
 348 #define SCM_CHECK_NOT_ENABLED
 349 #endif
 350
 351
 352 /* Anthony Green writes:
 353    When the compiler sees...
 354            DEFER_INTS;
 355            [critical code here]
 356            ALLOW_INTS;
 357    ...it doesn't actually promise to keep the critical code within the
 358    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 359    schedule it outside of the magic defined in those macros.
 360
 361    However, GCC's volatile asm feature forms a barrier over which code is
 362    never moved. So if you add...
 363            asm ("");
 364    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 365    code will always remain in place.  asm's without inputs or outputs
 366    are implicitly volatile. */
 367 #ifdef __GNUC__
 368 #define SCM_FENCE asm /* volatile */ ("")
 369 #else
 370 #define SCM_FENCE
 371 #endif
 372
 373 #define SCM_DEFER_INTS \
 374 do { \
 375   SCM_FENCE; \
 376   SCM_CHECK_NOT_DISABLED; \
 377   SCM_THREAD_DEFER; \
 378   SCM_FENCE; \
 379   scm_ints_disabled = 1; \
 380   SCM_FENCE; \
 381 } while (0)
 382
 383
 384 #define SCM_ALLOW_INTS_ONLY \
 385 do { \
 386   SCM_THREAD_ALLOW; \
 387   scm_ints_disabled = 0; \
 388 } while (0)
 389
 390
 391 #define SCM_ALLOW_INTS \
 392 do { \
 393   SCM_FENCE; \
 394   SCM_CHECK_NOT_ENABLED; \
 395   SCM_THREAD_SWITCHING_CODE; \
 396   SCM_FENCE; \
 397   scm_ints_disabled = 0; \
 398   SCM_FENCE; \
 399   SCM_THREAD_ALLOW; \
 400   SCM_FENCE; \
 401 } while (0)
 402
 403
 404 #define SCM_REDEFER_INTS  \
 405 do { \
 406   SCM_FENCE; \
 407   SCM_THREAD_REDEFER; \
 408   ++scm_ints_disabled; \
 409   SCM_FENCE; \
 410 } while (0)
 411
 412
 413 #define SCM_REALLOW_INTS \
 414 do { \
 415   SCM_FENCE; \
 416   SCM_THREAD_SWITCHING_CODE; \
 417   SCM_FENCE; \
 418   --scm_ints_disabled; \
 419   SCM_FENCE; \
 420 } while (0)
 421
 422
 423 #define SCM_TICK \
 424 do { \
 425   SCM_DEFER_INTS; \
 426   SCM_ALLOW_INTS; \
 427   SCM_ASYNC_TICK; \
 428 } while (0)
 429
 430 \f
 431
 432 /* Classification of critical sections
 433  *
 434  * When Guile moves to POSIX threads, it won't be possible to prevent
 435  * context switching.  In fact, the whole idea of context switching is
 436  * bogus if threads are run by different processors.  Therefore, we
 437  * must ultimately eliminate all critical sections or enforce them by
 438  * use of mutecis.
 439  *
 440  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 441  * be classified and replaced by one of the delimiters below.  If you
 442  * understand what this is all about, I'd like to encourage you to
 443  * help with this task.  The set of classes below must of course be
 444  * incrementally augmented.
 445  *
 446  * MDJ 980419 <djurfeldt@nada.kth.se>
 447  */
 448
 449 /* A sections
 450  *
 451  * Allocation of a cell with type tag in the CAR.
 452  *
 453  * With POSIX threads, each thread will have a private pool of free
 454  * cells.  Therefore, this type of section can be removed.  But!  It
 455  * is important that the CDR is initialized first (with the CAR still
 456  * indicating a free cell) so that we can guarantee a consistent heap
 457  * at all times.
 458  */
 459
 460 #ifdef SCM_POSIX_THREADS
 461 #define SCM_ENTER_A_SECTION
 462 #define SCM_EXIT_A_SECTION
 463 #else
 464 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 465 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 466 #endif
 467
 468 \f
 469
 470 /** SCM_ASSERT
 471  **
 472  **/
 473
 474
 475 #ifdef SCM_RECKLESS
 476 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 477 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr)
 478 #define SCM_ASRTGO(_cond, _label)
 479 #else
 480 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 481         if (!(_cond)) \
 482           scm_wta(_arg, (char *)(_pos), _subr)
 483 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg) \
 484         if (!(_cond)) \
 485           scm_wrong_type_arg_msg(_subr, _pos, _arg, _msg)
 486 #define SCM_ASRTGO(_cond, _label) \
 487         if (!(_cond)) \
 488           goto _label
 489 #endif
 490
 491 /*
 492  * SCM_WTA_DISPATCH
 493  */
 494
 495 /* Dirk:FIXME:: In all of the SCM_WTA_DISPATCH_* macros it is assumed that
 496  * 'gf' is zero if uninitialized.  It would be cleaner if some valid SCM value
 497  * like SCM_BOOL_F or SCM_UNDEFINED was chosen.
 498  */
 499
 500 extern SCM scm_call_generic_0 (SCM gf);
 501
 502 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 503   return (SCM_UNPACK (gf) \
 504           ? scm_call_generic_0 ((gf)) \
 505           : scm_wta ((arg), (char *) (pos), (subr)))
 506 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 507   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (arg), (pos), (subr))
 508
 509 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 510
 511 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 512   return (SCM_UNPACK (gf) \
 513           ? scm_call_generic_1 ((gf), (a1)) \
 514           : scm_wta ((a1), (char *) (pos), (subr)))
 515 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 516   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 517
 518 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 519
 520 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 521   return (SCM_UNPACK (gf) \
 522           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 523           : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
 524 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 525   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 526
 527 extern SCM scm_apply_generic (SCM gf, SCM args);
 528
 529 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 530   return (SCM_UNPACK (gf) \
 531           ? scm_apply_generic ((gf), (args)) \
 532           : scm_wta (scm_list_ref ((args), SCM_MAKINUM ((pos) - 1)), \
 533                      (char *) (pos), \
 534                      (subr)))
 535 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 536   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 537
 538 #ifndef SCM_MAGIC_SNARFER
 539 /* Let these macros pass through if
 540    we are snarfing;  thus we can tell the
 541    difference between the use of an actual
 542    number vs. the use of one of these macros --
 543    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 544    constructs must match the formal argument name,
 545    but using SCM_ARG* avoids the test */
 546
 547 #define SCM_ARGn                0
 548 #define SCM_ARG1                1
 549 #define SCM_ARG2                2
 550 #define SCM_ARG3                3
 551 #define SCM_ARG4                4
 552 #define SCM_ARG5                5
 553 #define SCM_ARG6                6
 554 #define SCM_ARG7                7
 555
 556 /* SCM_WNA must follow the last SCM_ARGn in sequence.
 557  */
 558 #define SCM_WNA                 8
 559
 560 #if (SCM_DEBUG_DEPRECATED == 0)
 561
 562 /* Use SCM_ASSERT_RANGE or SCM_VALIDATE_XXX_RANGE instead of: */
 563 #define SCM_OUTOFRANGE         10
 564
 565 /* Use scm_memory_error instead of: */
 566 #define SCM_NALLOC             11
 567
 568 #define SCM_HUP_SIGNAL         14
 569 #define SCM_INT_SIGNAL         15
 570 #define SCM_FPE_SIGNAL         16
 571 #define SCM_BUS_SIGNAL         17
 572 #define SCM_SEGV_SIGNAL        18
 573 #define SCM_ALRM_SIGNAL        19
 574 #define SCM_GC_SIGNAL          20
 575 #define SCM_TICK_SIGNAL        21
 576 #define SCM_SIG_ORD(X)         ((X) - SCM_HUP_SIGNAL)
 577 #define SCM_ORD_SIG(X)         ((X) + SCM_HUP_SIGNAL)
 578 #define SCM_NUM_SIGS           (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 579
 580 #endif  /* SCM_DEBUG_DEPRECATED == 0 */
 581
 582 #endif /* SCM_MAGIC_SNARFER */
 583
 584 \f
 585
 586 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 587  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 588  * SCM if errors were encountered.  The return code can be explicitly
 589  * specified in a SCM program with (scm_quit <n>).
 590  */
 591
 592 #ifndef SCM_EXIT_SUCCESS
 593 #ifdef vms
 594 #define SCM_EXIT_SUCCESS 1
 595 #else
 596 #define SCM_EXIT_SUCCESS 0
 597 #endif /* def vms */
 598 #endif /* ndef SCM_EXIT_SUCCESS */
 599 #ifndef SCM_EXIT_FAILURE
 600 #ifdef vms
 601 #define SCM_EXIT_FAILURE 2
 602 #else
 603 #define SCM_EXIT_FAILURE 1
 604 #endif /* def vms */
 605 #endif /* ndef SCM_EXIT_FAILURE */
 606
 607 \f
 608
 609 #endif  /* __SCMH */
 610
 611 /*
 612   Local Variables:
 613   c-file-style: "gnu"
 614   End:
 615 */