libguile/__scm.h

   1 /* classes: h_files */
   2
   3 #ifndef __SCMH
   4 #define __SCMH
   5 /* Copyright (C) 1995,1996,1998,1999,2000,2001 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 /* {Architecture and compiler properties}
 207  *
 208  * Guile as of today can only work on systems which fulfill at least the
 209  * following requirements:
 210  * - long ints have at least 32 bits.
 211  *   Guile's type system is based on this assumption.
 212  * - long ints consist of at least four characters.
 213  *   It is assumed that cells, i. e. pairs of long ints, are eight character
 214  *   aligned, because three bits of a cell pointer are used for type data.
 215  * - sizeof (void*) == sizeof (long int)
 216  *   Pointers are stored in SCM objects, and sometimes SCM objects are passed
 217  *   as void*.  Thus, there has to be a one-to-one correspondence.
 218  * - numbers are encoded using two's complement.
 219  *   The implementation of the bitwise scheme level operations is based on
 220  *   this assumption.
 221  * - ... add more
 222  */
 223
 224 #ifdef HAVE_LIMITS_H
 225 # include <limits.h>
 226 #endif
 227
 228 #ifdef CHAR_BIT
 229 # define SCM_CHAR_BIT CHAR_BIT
 230 #else
 231 # define SCM_CHAR_BIT 8
 232 #endif
 233
 234 #ifdef LONG_BIT
 235 # define SCM_LONG_BIT LONG_BIT
 236 #else
 237 # define SCM_LONG_BIT (SCM_CHAR_BIT * sizeof (long) / sizeof (char))
 238 #endif
 239
 240 #ifdef UCHAR_MAX
 241 # define SCM_CHAR_CODE_LIMIT (UCHAR_MAX + 1L)
 242 #else
 243 # define SCM_CHAR_CODE_LIMIT 256L
 244 #endif
 245
 246 \f
 247
 248 #ifdef STDC_HEADERS
 249 # include <stdlib.h>
 250 # ifdef AMIGA
 251 #  include <stddef.h>
 252 # endif /* def AMIGA */
 253 # define scm_sizet size_t
 254 #else
 255 # ifdef _SIZE_T
 256 #  define scm_sizet size_t
 257 # else
 258 #  define scm_sizet unsigned int
 259 # endif /* def _SIZE_T */
 260 #endif /* def STDC_HEADERS */
 261
 262 \f
 263
 264 #include "libguile/tags.h"
 265
 266 \f
 267 #ifdef vms
 268 # ifndef CHEAP_CONTINUATIONS
 269    typedef int jmp_buf[17];
 270    extern int setjump(jmp_buf env);
 271    extern int longjump(jmp_buf env, int ret);
 272 #  define setjmp setjump
 273 #  define longjmp longjump
 274 # else
 275 #  include <setjmp.h>
 276 # endif
 277 #else                           /* ndef vms */
 278 # ifdef _CRAY1
 279     typedef int jmp_buf[112];
 280     extern int setjump(jmp_buf env);
 281     extern int longjump(jmp_buf env, int ret);
 282 #  define setjmp setjump
 283 #  define longjmp longjump
 284 # else                          /* ndef _CRAY1 */
 285 #  include <setjmp.h>
 286 # endif                         /* ndef _CRAY1 */
 287 #endif                          /* ndef vms */
 288
 289 /* James Clark came up with this neat one instruction fix for
 290  * continuations on the SPARC.  It flushes the register windows so
 291  * that all the state of the process is contained in the stack.
 292  */
 293
 294 #ifdef sparc
 295 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 296 #else
 297 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 298 #endif
 299
 300 /* If stack is not longword aligned then
 301  */
 302
 303 /* #define SHORT_ALIGN */
 304 #ifdef THINK_C
 305 # define SHORT_ALIGN
 306 #endif
 307 #ifdef MSDOS
 308 # define SHORT_ALIGN
 309 #endif
 310 #ifdef atarist
 311 # define SHORT_ALIGN
 312 #endif
 313
 314 #ifdef SHORT_ALIGN
 315 typedef short SCM_STACKITEM;
 316 #else
 317 typedef long SCM_STACKITEM;
 318 #endif
 319 \f
 320
 321 #ifndef USE_THREADS
 322 #define SCM_THREAD_DEFER
 323 #define SCM_THREAD_ALLOW
 324 #define SCM_THREAD_REDEFER
 325 #define SCM_THREAD_SWITCHING_CODE
 326 #endif
 327
 328 #ifdef GUILE_OLD_ASYNC_CLICK
 329 extern unsigned int scm_async_clock;
 330
 331 #define SCM_ASYNC_TICK \
 332 do { \
 333   if (0 == --scm_async_clock) \
 334     scm_async_click (); \
 335 } while(0)
 336 #else
 337 extern int scm_asyncs_pending_p;
 338
 339 #define SCM_ASYNC_TICK /*fixme* should change names */ \
 340 do { \
 341   if (scm_asyncs_pending_p) \
 342     scm_async_click (); \
 343 } while (0)
 344 #endif
 345
 346 #ifdef SCM_CAREFUL_INTS
 347 #define SCM_CHECK_NOT_DISABLED \
 348   if (scm_ints_disabled) \
 349     fputs("ints already disabled\n", stderr); \
 350
 351 #define SCM_CHECK_NOT_ENABLED \
 352   if (!scm_ints_disabled) \
 353     fputs("ints already enabled\n", stderr); \
 354
 355 #else
 356 #define SCM_CHECK_NOT_DISABLED
 357 #define SCM_CHECK_NOT_ENABLED
 358 #endif
 359
 360
 361 /* Anthony Green writes:
 362    When the compiler sees...
 363            DEFER_INTS;
 364            [critical code here]
 365            ALLOW_INTS;
 366    ...it doesn't actually promise to keep the critical code within the
 367    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 368    schedule it outside of the magic defined in those macros.
 369
 370    However, GCC's volatile asm feature forms a barrier over which code is
 371    never moved. So if you add...
 372            asm ("");
 373    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 374    code will always remain in place.  asm's without inputs or outputs
 375    are implicitly volatile. */
 376 #ifdef __GNUC__
 377 #define SCM_FENCE asm /* volatile */ ("")
 378 #else
 379 #define SCM_FENCE
 380 #endif
 381
 382 #define SCM_DEFER_INTS \
 383 do { \
 384   SCM_FENCE; \
 385   SCM_CHECK_NOT_DISABLED; \
 386   SCM_THREAD_DEFER; \
 387   SCM_FENCE; \
 388   scm_ints_disabled = 1; \
 389   SCM_FENCE; \
 390 } while (0)
 391
 392
 393 #define SCM_ALLOW_INTS_ONLY \
 394 do { \
 395   SCM_THREAD_ALLOW; \
 396   scm_ints_disabled = 0; \
 397 } while (0)
 398
 399
 400 #define SCM_ALLOW_INTS \
 401 do { \
 402   SCM_FENCE; \
 403   SCM_CHECK_NOT_ENABLED; \
 404   SCM_THREAD_SWITCHING_CODE; \
 405   SCM_FENCE; \
 406   scm_ints_disabled = 0; \
 407   SCM_FENCE; \
 408   SCM_THREAD_ALLOW; \
 409   SCM_FENCE; \
 410 } while (0)
 411
 412
 413 #define SCM_REDEFER_INTS  \
 414 do { \
 415   SCM_FENCE; \
 416   SCM_THREAD_REDEFER; \
 417   ++scm_ints_disabled; \
 418   SCM_FENCE; \
 419 } while (0)
 420
 421
 422 #define SCM_REALLOW_INTS \
 423 do { \
 424   SCM_FENCE; \
 425   SCM_THREAD_SWITCHING_CODE; \
 426   SCM_FENCE; \
 427   --scm_ints_disabled; \
 428   SCM_FENCE; \
 429 } while (0)
 430
 431
 432 #define SCM_TICK \
 433 do { \
 434   SCM_DEFER_INTS; \
 435   SCM_ALLOW_INTS; \
 436   SCM_ASYNC_TICK; \
 437 } while (0)
 438
 439 \f
 440
 441 /* Classification of critical sections
 442  *
 443  * When Guile moves to POSIX threads, it won't be possible to prevent
 444  * context switching.  In fact, the whole idea of context switching is
 445  * bogus if threads are run by different processors.  Therefore, we
 446  * must ultimately eliminate all critical sections or enforce them by
 447  * use of mutecis.
 448  *
 449  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 450  * be classified and replaced by one of the delimiters below.  If you
 451  * understand what this is all about, I'd like to encourage you to
 452  * help with this task.  The set of classes below must of course be
 453  * incrementally augmented.
 454  *
 455  * MDJ 980419 <djurfeldt@nada.kth.se>
 456  */
 457
 458 /* A sections
 459  *
 460  * Allocation of a cell with type tag in the CAR.
 461  *
 462  * With POSIX threads, each thread will have a private pool of free
 463  * cells.  Therefore, this type of section can be removed.  But!  It
 464  * is important that the CDR is initialized first (with the CAR still
 465  * indicating a free cell) so that we can guarantee a consistent heap
 466  * at all times.
 467  */
 468
 469 #ifdef SCM_POSIX_THREADS
 470 #define SCM_ENTER_A_SECTION
 471 #define SCM_EXIT_A_SECTION
 472 #else
 473 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 474 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 475 #endif
 476
 477 \f
 478
 479 /** SCM_ASSERT
 480  **
 481  **/
 482
 483
 484 #ifdef SCM_RECKLESS
 485 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 486 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg)
 487 #define SCM_ASRTGO(_cond, _label)
 488 #else
 489 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 490         if (!(_cond)) \
 491           scm_wrong_type_arg (_subr, _pos, _arg)
 492 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg) \
 493         if (!(_cond)) \
 494           scm_wrong_type_arg_msg(_subr, _pos, _arg, _msg)
 495 #define SCM_ASRTGO(_cond, _label) \
 496         if (!(_cond)) \
 497           goto _label
 498 #endif
 499
 500 /*
 501  * SCM_WTA_DISPATCH
 502  */
 503
 504 /* Dirk:FIXME:: In all of the SCM_WTA_DISPATCH_* macros it is assumed that
 505  * 'gf' is zero if uninitialized.  It would be cleaner if some valid SCM value
 506  * like SCM_BOOL_F or SCM_UNDEFINED was chosen.
 507  */
 508
 509 extern SCM scm_call_generic_0 (SCM gf);
 510
 511 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 512   return (SCM_UNPACK (gf) \
 513           ? scm_call_generic_0 ((gf)) \
 514           : scm_wrong_type_arg ((subr), (pos), (arg)), 0)
 515 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 516   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (arg), (pos), (subr))
 517
 518 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 519
 520 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 521   return (SCM_UNPACK (gf) \
 522           ? scm_call_generic_1 ((gf), (a1)) \
 523           : scm_wrong_type_arg ((subr), (pos), (a1)), 0)
 524 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 525   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 526
 527 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 528
 529 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 530   return (SCM_UNPACK (gf) \
 531           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 532           : scm_wrong_type_arg ((subr), (pos), \
 533                                 (pos) == SCM_ARG1 ? (a1) : (a2)), 0)
 534 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 535   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 536
 537 extern SCM scm_apply_generic (SCM gf, SCM args);
 538
 539 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 540   return (SCM_UNPACK (gf) \
 541           ? scm_apply_generic ((gf), (args)) \
 542           : scm_wrong_type_arg ((subr), (pos), \
 543                                 scm_list_ref ((args), \
 544                                               SCM_MAKINUM ((pos) - 1))), 0)
 545 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 546   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 547
 548 #ifndef SCM_MAGIC_SNARFER
 549 /* Let these macros pass through if
 550    we are snarfing;  thus we can tell the
 551    difference between the use of an actual
 552    number vs. the use of one of these macros --
 553    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 554    constructs must match the formal argument name,
 555    but using SCM_ARG* avoids the test */
 556
 557 #define SCM_ARGn                0
 558 #define SCM_ARG1                1
 559 #define SCM_ARG2                2
 560 #define SCM_ARG3                3
 561 #define SCM_ARG4                4
 562 #define SCM_ARG5                5
 563 #define SCM_ARG6                6
 564 #define SCM_ARG7                7
 565
 566 #if (SCM_DEBUG_DEPRECATED == 0)
 567
 568 /* Use SCM_WRONG_NUM_ARGS instead of: */
 569 #define SCM_WNA                 8
 570
 571 /* Use SCM_ASSERT_RANGE or SCM_VALIDATE_XXX_RANGE instead of: */
 572 #define SCM_OUTOFRANGE         10
 573
 574 /* Use scm_memory_error instead of: */
 575 #define SCM_NALLOC             11
 576
 577 #define SCM_HUP_SIGNAL         14
 578 #define SCM_INT_SIGNAL         15
 579 #define SCM_FPE_SIGNAL         16
 580 #define SCM_BUS_SIGNAL         17
 581 #define SCM_SEGV_SIGNAL        18
 582 #define SCM_ALRM_SIGNAL        19
 583 #define SCM_GC_SIGNAL          20
 584 #define SCM_TICK_SIGNAL        21
 585 #define SCM_SIG_ORD(X)         ((X) - SCM_HUP_SIGNAL)
 586 #define SCM_ORD_SIG(X)         ((X) + SCM_HUP_SIGNAL)
 587 #define SCM_NUM_SIGS           (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 588
 589 #endif  /* SCM_DEBUG_DEPRECATED == 0 */
 590
 591 #endif /* SCM_MAGIC_SNARFER */
 592
 593 \f
 594
 595 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 596  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 597  * SCM if errors were encountered.  The return code can be explicitly
 598  * specified in a SCM program with (scm_quit <n>).
 599  */
 600
 601 #ifndef SCM_EXIT_SUCCESS
 602 #ifdef vms
 603 #define SCM_EXIT_SUCCESS 1
 604 #else
 605 #define SCM_EXIT_SUCCESS 0
 606 #endif /* def vms */
 607 #endif /* ndef SCM_EXIT_SUCCESS */
 608 #ifndef SCM_EXIT_FAILURE
 609 #ifdef vms
 610 #define SCM_EXIT_FAILURE 2
 611 #else
 612 #define SCM_EXIT_FAILURE 1
 613 #endif /* def vms */
 614 #endif /* ndef SCM_EXIT_FAILURE */
 615
 616 \f
 617
 618 #endif  /* __SCMH */
 619
 620 /*
 621   Local Variables:
 622   c-file-style: "gnu"
 623   End:
 624 */