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 /* What did the configure script discover about the outside world?  */
 131 #include "libguile/scmconfig.h"
 132
 133 #ifdef HAVE_LONG_LONGS
 134
 135 /* Some auto-generated .h files contain unused prototypes
 136  * that need these typedefs.
 137  */
 138 typedef long long long_long;
 139 typedef unsigned long long ulong_long;
 140
 141 #endif /* HAVE_LONG_LONGS */
 142
 143 \f
 144
 145 /* Define
 146  *
 147  * SCM_CHAR_CODE_LIMIT          == UCHAR_MAX + 1
 148  * SCM_MOST_POSITIVE_FIXNUM     (LONG_MAX>>2)
 149  * SCM_MOST_NEGATIVE_FIXNUM     == SCM_SRS((long)LONG_MIN, 2)
 150  */
 151
 152 #ifdef HAVE_LIMITS_H
 153 # include <limits.h>
 154 # ifdef UCHAR_MAX
 155 #  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
 156 # else
 157 #  define SCM_CHAR_CODE_LIMIT 256L
 158 # endif /* def UCHAR_MAX */
 159 # define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
 160 # ifdef _UNICOS                 /* Stupid cray bug */
 161 #  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
 162 # else
 163 #  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
 164 # endif                         /* UNICOS */
 165 #else
 166 # define SCM_CHAR_CODE_LIMIT 256L
 167 # define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
 168 # if (0 != ~0)
 169 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
 170 # else
 171 #  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
 172 # endif /*  (0 != ~0) */
 173 #endif /* def HAVE_LIMITS_H */
 174 \f
 175
 176 #ifdef STDC_HEADERS
 177 # include <stdlib.h>
 178 # ifdef AMIGA
 179 #  include <stddef.h>
 180 # endif /* def AMIGA */
 181 # define scm_sizet size_t
 182 #else
 183 # ifdef _SIZE_T
 184 #  define scm_sizet size_t
 185 # else
 186 #  define scm_sizet unsigned int
 187 # endif /* def _SIZE_T */
 188 #endif /* def STDC_HEADERS */
 189
 190 \f
 191
 192 #include "libguile/tags.h"
 193
 194 \f
 195 #ifdef vms
 196 # ifndef CHEAP_CONTINUATIONS
 197    typedef int jmp_buf[17];
 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
 203 #  include <setjmp.h>
 204 # endif
 205 #else                           /* ndef vms */
 206 # ifdef _CRAY1
 207     typedef int jmp_buf[112];
 208     extern int setjump(jmp_buf env);
 209     extern int longjump(jmp_buf env, int ret);
 210 #  define setjmp setjump
 211 #  define longjmp longjump
 212 # else                          /* ndef _CRAY1 */
 213 #  include <setjmp.h>
 214 # endif                         /* ndef _CRAY1 */
 215 #endif                          /* ndef vms */
 216
 217 /* James Clark came up with this neat one instruction fix for
 218  * continuations on the SPARC.  It flushes the register windows so
 219  * that all the state of the process is contained in the stack.
 220  */
 221
 222 #ifdef sparc
 223 # define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
 224 #else
 225 # define SCM_FLUSH_REGISTER_WINDOWS /* empty */
 226 #endif
 227
 228 /* If stack is not longword aligned then
 229  */
 230
 231 /* #define SHORT_ALIGN */
 232 #ifdef THINK_C
 233 # define SHORT_ALIGN
 234 #endif
 235 #ifdef MSDOS
 236 # define SHORT_ALIGN
 237 #endif
 238 #ifdef atarist
 239 # define SHORT_ALIGN
 240 #endif
 241
 242 #ifdef SHORT_ALIGN
 243 typedef short SCM_STACKITEM;
 244 #else
 245 typedef long SCM_STACKITEM;
 246 #endif
 247 \f
 248
 249 #ifndef USE_THREADS
 250 #define SCM_THREAD_DEFER
 251 #define SCM_THREAD_ALLOW
 252 #define SCM_THREAD_REDEFER
 253 #define SCM_THREAD_SWITCHING_CODE
 254 #endif
 255
 256 #ifdef GUILE_OLD_ASYNC_CLICK
 257 extern unsigned int scm_async_clock;
 258
 259 #define SCM_ASYNC_TICK \
 260 do { \
 261   if (0 == --scm_async_clock) \
 262     scm_async_click (); \
 263 } while(0)
 264 #else
 265 extern int scm_asyncs_pending_p;
 266
 267 #define SCM_ASYNC_TICK /*fixme* should change names */ \
 268 do { \
 269   if (scm_asyncs_pending_p) \
 270     scm_async_click (); \
 271 } while (0)
 272 #endif
 273
 274 #ifdef SCM_CAREFUL_INTS
 275 #define SCM_CHECK_NOT_DISABLED \
 276   if (scm_ints_disabled) \
 277     fputs("ints already disabled\n", stderr); \
 278
 279 #define SCM_CHECK_NOT_ENABLED \
 280   if (!scm_ints_disabled) \
 281     fputs("ints already enabled\n", stderr); \
 282
 283 #else
 284 #define SCM_CHECK_NOT_DISABLED
 285 #define SCM_CHECK_NOT_ENABLED
 286 #endif
 287
 288
 289 /* Anthony Green writes:
 290    When the compiler sees...
 291            DEFER_INTS;
 292            [critical code here]
 293            ALLOW_INTS;
 294    ...it doesn't actually promise to keep the critical code within the
 295    boundries of the DEFER/ALLOW_INTS instructions. It may very well
 296    schedule it outside of the magic defined in those macros.
 297
 298    However, GCC's volatile asm feature forms a barrier over which code is
 299    never moved. So if you add...
 300            asm ("");
 301    ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
 302    code will always remain in place.  asm's without inputs or outputs
 303    are implicitly volatile. */
 304 #ifdef __GNUC__
 305 #define SCM_FENCE asm /* volatile */ ("")
 306 #else
 307 #define SCM_FENCE
 308 #endif
 309
 310 #define SCM_DEFER_INTS \
 311 do { \
 312   SCM_FENCE; \
 313   SCM_CHECK_NOT_DISABLED; \
 314   SCM_THREAD_DEFER; \
 315   SCM_FENCE; \
 316   scm_ints_disabled = 1; \
 317   SCM_FENCE; \
 318 } while (0)
 319
 320
 321 #define SCM_ALLOW_INTS_ONLY \
 322 do { \
 323   SCM_THREAD_ALLOW; \
 324   scm_ints_disabled = 0; \
 325 } while (0)
 326
 327
 328 #define SCM_ALLOW_INTS \
 329 do { \
 330   SCM_FENCE; \
 331   SCM_CHECK_NOT_ENABLED; \
 332   SCM_THREAD_SWITCHING_CODE; \
 333   SCM_FENCE; \
 334   scm_ints_disabled = 0; \
 335   SCM_FENCE; \
 336   SCM_THREAD_ALLOW; \
 337   SCM_FENCE; \
 338 } while (0)
 339
 340
 341 #define SCM_REDEFER_INTS  \
 342 do { \
 343   SCM_FENCE; \
 344   SCM_THREAD_REDEFER; \
 345   ++scm_ints_disabled; \
 346   SCM_FENCE; \
 347 } while (0)
 348
 349
 350 #define SCM_REALLOW_INTS \
 351 do { \
 352   SCM_FENCE; \
 353   SCM_THREAD_SWITCHING_CODE; \
 354   SCM_FENCE; \
 355   --scm_ints_disabled; \
 356   SCM_FENCE; \
 357 } while (0)
 358
 359
 360 #define SCM_TICK \
 361 do { \
 362   SCM_DEFER_INTS; \
 363   SCM_ALLOW_INTS; \
 364   SCM_ASYNC_TICK; \
 365 } while (0)
 366
 367 \f
 368
 369 /* Classification of critical sections
 370  *
 371  * When Guile moves to POSIX threads, it won't be possible to prevent
 372  * context switching.  In fact, the whole idea of context switching is
 373  * bogus if threads are run by different processors.  Therefore, we
 374  * must ultimately eliminate all critical sections or enforce them by
 375  * use of mutecis.
 376  *
 377  * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 378  * be classified and replaced by one of the delimiters below.  If you
 379  * understand what this is all about, I'd like to encourage you to
 380  * help with this task.  The set of classes below must of course be
 381  * incrementally augmented.
 382  *
 383  * MDJ 980419 <djurfeldt@nada.kth.se>
 384  */
 385
 386 /* A sections
 387  *
 388  * Allocation of a cell with type tag in the CAR.
 389  *
 390  * With POSIX threads, each thread will have a private pool of free
 391  * cells.  Therefore, this type of section can be removed.  But!  It
 392  * is important that the CDR is initialized first (with the CAR still
 393  * indicating a free cell) so that we can guarantee a consistent heap
 394  * at all times.
 395  */
 396
 397 #ifdef SCM_POSIX_THREADS
 398 #define SCM_ENTER_A_SECTION
 399 #define SCM_EXIT_A_SECTION
 400 #else
 401 #define SCM_ENTER_A_SECTION SCM_DEFER_INTS
 402 #define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
 403 #endif
 404
 405 \f
 406
 407 /** SCM_ASSERT
 408  **
 409  **/
 410
 411
 412 #ifdef SCM_RECKLESS
 413 #define SCM_ASSERT(_cond, _arg, _pos, _subr)
 414 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr)
 415 #define SCM_ASRTGO(_cond, _label)
 416 #else
 417 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 418         if (!(_cond)) \
 419           scm_wta(_arg, (char *)(_pos), _subr)
 420 #define SCM_ASSERT_TYPE(_cond, _arg, _pos, _subr, _msg) \
 421         if (!(_cond)) \
 422           scm_wrong_type_arg_msg(_subr, _pos, _arg, _msg)
 423 #define SCM_ASRTGO(_cond, _label) \
 424         if (!(_cond)) \
 425           goto _label
 426 #endif
 427
 428 /*
 429  * SCM_WTA_DISPATCH
 430  */
 431
 432 extern SCM scm_call_generic_0 (SCM gf);
 433
 434 #define SCM_WTA_DISPATCH_0(gf, arg, pos, subr) \
 435   return ((gf) \
 436           ? scm_call_generic_0 ((gf)) \
 437           : scm_wta ((arg), (char *) (pos), (subr)))
 438 #define SCM_GASSERT0(cond, gf, arg, pos, subr) \
 439   if (!(cond)) SCM_WTA_DISPATCH_0((gf), (arg), (pos), (subr))
 440
 441 extern SCM scm_call_generic_1 (SCM gf, SCM a1);
 442
 443 #define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
 444   return ((gf) \
 445           ? scm_call_generic_1 ((gf), (a1)) \
 446           : scm_wta ((a1), (char *) (pos), (subr)))
 447 #define SCM_GASSERT1(cond, gf, a1, pos, subr) \
 448   if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
 449
 450 extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
 451
 452 #define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
 453   return ((gf) \
 454           ? scm_call_generic_2 ((gf), (a1), (a2)) \
 455           : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
 456 #define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
 457   if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
 458
 459 extern SCM scm_apply_generic (SCM gf, SCM args);
 460
 461 #define SCM_WTA_DISPATCH_n(gf, args, pos, subr) \
 462   return ((gf) \
 463           ? scm_apply_generic ((gf), (args)) \
 464           : scm_wta (scm_list_ref ((args), SCM_MAKINUM ((pos) - 1)), \
 465                      (char *) (pos), \
 466                      (subr)))
 467 #define SCM_GASSERTn(cond, gf, args, pos, subr) \
 468   if (!(cond)) SCM_WTA_DISPATCH_n((gf), (args), (pos), (subr))
 469
 470 #ifndef SCM_MAGIC_SNARFER
 471 /* Let these macros pass through if
 472    we are snarfing;  thus we can tell the
 473    difference between the use of an actual
 474    number vs. the use of one of these macros --
 475    actual numbers in SCM_VALIDATE_* and SCM_ASSERT
 476    constructs must match the formal argument name,
 477    but using SCM_ARG* avoids the test */
 478
 479 #define SCM_ARGn                0
 480 #define SCM_ARG1                1
 481 #define SCM_ARG2                2
 482 #define SCM_ARG3                3
 483 #define SCM_ARG4                4
 484 #define SCM_ARG5                5
 485 #define SCM_ARG6                6
 486 #define SCM_ARG7                7
 487      /* #define SCM_ARGERR(X)           ((X) < SCM_WNA \
 488                                  ? (char *)(X) \
 489                                  : "wrong type argument")
 490                                  */
 491
 492 /* Following must match entry indexes in scm_errmsgs[].
 493  * Also, SCM_WNA must follow the last SCM_ARGn in sequence.
 494  */
 495 #define SCM_WNA                 8
 496      /* #define SCM_OVSCM_FLOW          9 */
 497 #define SCM_OUTOFRANGE          10
 498 #define SCM_NALLOC              11
 499      /* #define SCM_STACK_OVFLOW        12 */
 500      /* #define SCM_EXIT                13 */
 501
 502 #endif /* SCM_MAGIC_SNARFER */
 503
 504 /* (...still matching scm_errmsgs)  These
 505  * are signals.  Signals may become errors
 506  * but are distinguished because they first
 507  * try to invoke a handler that can resume
 508  * the interrupted routine.
 509  */
 510 #define SCM_HUP_SIGNAL          14
 511 #define SCM_INT_SIGNAL          15
 512 #define SCM_FPE_SIGNAL          16
 513 #define SCM_BUS_SIGNAL          17
 514 #define SCM_SEGV_SIGNAL         18
 515 #define SCM_ALRM_SIGNAL         19
 516 #define SCM_GC_SIGNAL           20
 517 #define SCM_TICK_SIGNAL         21
 518
 519 #define SCM_SIG_ORD(X)          ((X) - SCM_HUP_SIGNAL)
 520 #define SCM_ORD_SIG(X)          ((X) + SCM_HUP_SIGNAL)
 521 #define SCM_NUM_SIGS            (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
 522
 523 #if 0
 524 struct errdesc
 525 {
 526   char *msg;
 527   char *s_response;
 528   short parent_err;
 529 };
 530
 531
 532 extern struct errdesc scm_errmsgs[];
 533 #endif
 534
 535 \f
 536
 537 /* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 538  * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 539  * SCM if errors were encountered.  The return code can be explicitly
 540  * specified in a SCM program with (scm_quit <n>).
 541  */
 542
 543 #ifndef SCM_EXIT_SUCCESS
 544 #ifdef vms
 545 #define SCM_EXIT_SUCCESS 1
 546 #else
 547 #define SCM_EXIT_SUCCESS 0
 548 #endif /* def vms */
 549 #endif /* ndef SCM_EXIT_SUCCESS */
 550 #ifndef SCM_EXIT_FAILURE
 551 #ifdef vms
 552 #define SCM_EXIT_FAILURE 2
 553 #else
 554 #define SCM_EXIT_FAILURE 1
 555 #endif /* def vms */
 556 #endif /* ndef SCM_EXIT_FAILURE */
 557
 558
 559
 560 \f
 561
 562 #endif  /* __SCMH */
 563
 564 /*
 565   Local Variables:
 566   c-file-style: "gnu"
 567   End:
 568 */