| 1 | /* classes: h_files */ |
| 2 | |
| 3 | #ifndef SCM_TAGS_H |
| 4 | #define SCM_TAGS_H |
| 5 | |
| 6 | /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2, or (at your option) |
| 11 | * any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this software; see the file COPYING. If not, write to |
| 20 | * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
| 21 | * Boston, MA 02111-1307 USA |
| 22 | * |
| 23 | * As a special exception, the Free Software Foundation gives permission |
| 24 | * for additional uses of the text contained in its release of GUILE. |
| 25 | * |
| 26 | * The exception is that, if you link the GUILE library with other files |
| 27 | * to produce an executable, this does not by itself cause the |
| 28 | * resulting executable to be covered by the GNU General Public License. |
| 29 | * Your use of that executable is in no way restricted on account of |
| 30 | * linking the GUILE library code into it. |
| 31 | * |
| 32 | * This exception does not however invalidate any other reasons why |
| 33 | * the executable file might be covered by the GNU General Public License. |
| 34 | * |
| 35 | * This exception applies only to the code released by the |
| 36 | * Free Software Foundation under the name GUILE. If you copy |
| 37 | * code from other Free Software Foundation releases into a copy of |
| 38 | * GUILE, as the General Public License permits, the exception does |
| 39 | * not apply to the code that you add in this way. To avoid misleading |
| 40 | * anyone as to the status of such modified files, you must delete |
| 41 | * this exception notice from them. |
| 42 | * |
| 43 | * If you write modifications of your own for GUILE, it is your choice |
| 44 | * whether to permit this exception to apply to your modifications. |
| 45 | * If you do not wish that, delete this exception notice. */ |
| 46 | |
| 47 | \f |
| 48 | |
| 49 | /** This file defines the format of SCM values and cons pairs. |
| 50 | ** It is here that tag bits are assigned for various purposes. |
| 51 | **/ |
| 52 | |
| 53 | #ifdef HAVE_STDINT_H |
| 54 | #include <stdint.h> |
| 55 | #endif |
| 56 | |
| 57 | #ifdef HAVE_INTTYPES_H |
| 58 | #include <inttypes.h> |
| 59 | #endif |
| 60 | |
| 61 | \f |
| 62 | |
| 63 | /* In the beginning was the Word: |
| 64 | */ |
| 65 | #ifdef HAVE_UINTPTR_T |
| 66 | typedef uintptr_t scm_t_bits; |
| 67 | typedef intptr_t scm_t_signed_bits; |
| 68 | #define SIZEOF_SCM_T_BITS SIZEOF_UINTPTR_T |
| 69 | #define SCM_T_BITS_MAX UINTPTR_MAX |
| 70 | #define SCM_T_SIGNED_BITS_MAX INTPTR_MAX |
| 71 | #define SCM_T_SIGNED_BITS_MIN INTPTR_MIN |
| 72 | #else |
| 73 | typedef unsigned long scm_t_bits; |
| 74 | typedef signed long scm_t_signed_bits; |
| 75 | #define SIZEOF_SCM_T_BITS SIZEOF_LONG |
| 76 | #define SCM_T_BITS_MAX ULONG_MAX |
| 77 | #define SCM_T_SIGNED_BITS_MAX LONG_MAX |
| 78 | #define SCM_T_SIGNED_BITS_MIN LONG_MIN |
| 79 | #endif |
| 80 | |
| 81 | /* But as external interface, we use SCM, which may, according to the desired |
| 82 | * level of type checking, be defined in several ways: |
| 83 | */ |
| 84 | #if (SCM_DEBUG_TYPING_STRICTNESS == 2) |
| 85 | typedef union { struct { scm_t_bits n; } n; } SCM; |
| 86 | static SCM scm_pack(scm_t_bits b) { SCM s; s.n.n = b; return s; } |
| 87 | # define SCM_UNPACK(x) ((x).n.n) |
| 88 | # define SCM_PACK(x) (scm_pack ((scm_t_bits) (x))) |
| 89 | #elif (SCM_DEBUG_TYPING_STRICTNESS == 1) |
| 90 | /* This is the default, which provides an intermediate level of compile time |
| 91 | * type checking while still resulting in very efficient code. |
| 92 | */ |
| 93 | typedef struct scm_unused_struct * SCM; |
| 94 | # define SCM_UNPACK(x) ((scm_t_bits) (x)) |
| 95 | # define SCM_PACK(x) ((SCM) (x)) |
| 96 | #else |
| 97 | /* This should be used as a fall back solution for machines on which casting |
| 98 | * to a pointer may lead to loss of bit information, e. g. in the three least |
| 99 | * significant bits. |
| 100 | */ |
| 101 | typedef scm_t_bits SCM; |
| 102 | # define SCM_UNPACK(x) (x) |
| 103 | # define SCM_PACK(x) ((scm_t_bits) (x)) |
| 104 | #endif |
| 105 | |
| 106 | |
| 107 | /* SCM values can not be compared by using the operator ==. Use the following |
| 108 | * macro instead, which is the equivalent of the scheme predicate 'eq?'. |
| 109 | */ |
| 110 | #define SCM_EQ_P(x, y) (SCM_UNPACK (x) == SCM_UNPACK (y)) |
| 111 | |
| 112 | \f |
| 113 | |
| 114 | /* SCM variables can contain: |
| 115 | * |
| 116 | * Non-objects -- meaning that the tag-related macros don't apply to them |
| 117 | * in the usual way. |
| 118 | * |
| 119 | * Immediates -- meaning that the variable contains an entire Scheme object. |
| 120 | * |
| 121 | * Non-immediates -- meaning that the variable holds a (possibly |
| 122 | * tagged) pointer into the cons pair heap. |
| 123 | * |
| 124 | * Non-objects are distinguished from other values by careful coding |
| 125 | * only (i.e., programmers must keep track of any SCM variables they |
| 126 | * create that don't contain ordinary scheme values). |
| 127 | * |
| 128 | * All immediates and pointers to cells of non-immediates have a 0 in |
| 129 | * bit 0. All non-immediates that are not pairs have a 1 in bit 0 of |
| 130 | * the first word of their cell. This is how pairs are distinguished |
| 131 | * from other non-immediates; a pair can have a immediate in its car |
| 132 | * (thus a 0 in bit 0), or a pointer to the cell of a non-immediate |
| 133 | * (again, this pointer has a 0 in bit 0). |
| 134 | * |
| 135 | * Immediates and non-immediates are distinguished by bits 1 and 2. |
| 136 | * Immediate values must have a 1 in at least one of those bits. |
| 137 | * Consequently, a pointer to a cell of a non-immediate must have |
| 138 | * zeros in bits 1 and 2. Together with the requirement from above |
| 139 | * that bit 0 must also be zero, this means that pointers to cells of |
| 140 | * non-immediates must have their three low bits all zero. This in |
| 141 | * turn means that cells must be aligned on a 8 byte boundary, which |
| 142 | * is just right for two 32bit numbers (surprise, surprise). Does |
| 143 | * this (or any other detail of tagging) seem arbitrary? Try changing |
| 144 | * it! (Not always impossible but it is fair to say that many details |
| 145 | * of tags are mutually dependent). */ |
| 146 | |
| 147 | #define SCM_IMP(x) (6 & SCM_UNPACK (x)) |
| 148 | #define SCM_NIMP(x) (!SCM_IMP (x)) |
| 149 | |
| 150 | /* Here is a summary of tagging in SCM values as they might occur in |
| 151 | * SCM variables or in the heap. |
| 152 | * |
| 153 | * low bits meaning |
| 154 | * |
| 155 | * |
| 156 | * 0 Most objects except... |
| 157 | * 1 ... structs (this tag is valid only in the header |
| 158 | * of a struct's data, as with all odd tags). |
| 159 | * |
| 160 | * 00 heap addresses and many immediates (not integers) |
| 161 | * 01 structs, some tc7_ codes |
| 162 | * 10 immediate integers |
| 163 | * 11 various tc7_ codes including, tc16_ codes. |
| 164 | * |
| 165 | * |
| 166 | * 000 heap address |
| 167 | * 001 structs |
| 168 | * 010 integer |
| 169 | * 011 closure |
| 170 | * 100 immediates |
| 171 | * 101 tc7_ |
| 172 | * 110 integer |
| 173 | * 111 tc7_ |
| 174 | * |
| 175 | * |
| 176 | * 100 --- IMMEDIATES |
| 177 | * |
| 178 | * Looking at the seven final bits of an immediate: |
| 179 | * |
| 180 | * 0000-100 short instruction |
| 181 | * 0001-100 short instruction |
| 182 | * 0010-100 short instruction |
| 183 | * 0011-100 short instruction |
| 184 | * 0100-100 short instruction |
| 185 | * 0101-100 short instruction |
| 186 | * 0110-100 various immediates and long instructions |
| 187 | * 0111-100 short instruction |
| 188 | * 1000-100 short instruction |
| 189 | * 1001-100 short instruction |
| 190 | * 1010-100 short instruction |
| 191 | * 1011-100 short instruction |
| 192 | * 1100-100 short instruction |
| 193 | * 1101-100 short instruction |
| 194 | * 1110-100 immediate characters |
| 195 | * 1111-100 ilocs |
| 196 | * |
| 197 | * Some of the 0110100 immediates are long instructions (they dispatch |
| 198 | * in two steps compared to one step for a short instruction). |
| 199 | * The two steps are, (1) dispatch on 7 bits to the long instruction |
| 200 | * handler, (2) dispatch on 7 additional bits. |
| 201 | * |
| 202 | * One way to think of it is that there are 128 short instructions, |
| 203 | * with the 13 immediates above being some of the most interesting. |
| 204 | * |
| 205 | * Also noteworthy are the groups of 16 7-bit instructions implied by |
| 206 | * some of the 3-bit tags. For example, closure references consist of |
| 207 | * an 8-byte aligned address tagged with 011. There are 16 identical |
| 208 | * 7-bit instructions, all ending 011, which are invoked by evaluating |
| 209 | * closures. |
| 210 | * |
| 211 | * In other words, if you hand the evaluator a closure, the evaluator |
| 212 | * treats the closure as a graph of virtual machine instructions. A |
| 213 | * closure is a pair with a pointer to the body of the procedure in |
| 214 | * the CDR and a pointer to the environment of the closure in the CAR. |
| 215 | * The environment pointer is tagged 011 which implies that the least |
| 216 | * significant 7 bits of the environment pointer also happen to be a |
| 217 | * virtual machine instruction we could call "SELF" (for |
| 218 | * self-evaluating object). |
| 219 | * |
| 220 | * A less trivial example are the 16 instructions ending 000. If |
| 221 | * those bits tag the CAR of a pair, then evidently the pair is an |
| 222 | * ordinary cons pair and should be evaluated as a procedure |
| 223 | * application. The sixteen, 7-bit 000 instructions are all |
| 224 | * "NORMAL-APPLY" (Things get trickier. For example, if the CAR of a |
| 225 | * procedure application is a symbol, the NORMAL-APPLY instruction |
| 226 | * will, as a side effect, overwrite that CAR with a new instruction |
| 227 | * that contains a cached address for the variable named by the |
| 228 | * symbol.) |
| 229 | * |
| 230 | * Here is a summary of tags in the CAR of a non-immediate: |
| 231 | * |
| 232 | * HEAP CELL: G=gc_mark; 1 during mark, 0 other times. |
| 233 | * |
| 234 | * cons ..........SCM car..............0 ...........SCM cdr.............G |
| 235 | * struct ..........void * type........001 ...........void * data.........G |
| 236 | * closure ..........SCM code...........011 ...........SCM env.............G |
| 237 | * tc7 ......24.bits of data...Gxxxx1S1 ..........void *data............ |
| 238 | * |
| 239 | * |
| 240 | * |
| 241 | * 101 & 111 --- tc7_ types |
| 242 | * |
| 243 | * tc7_tags are 7 bit tags ending in 1x1. These tags |
| 244 | * occur only in the CAR of heap cells, and have the |
| 245 | * handy property that all bits of the CAR above the |
| 246 | * bottom eight can be used to store some data, thus |
| 247 | * saving a word in the body itself. Thus, we use them |
| 248 | * for strings and vectors (among other things). |
| 249 | * |
| 250 | * TYP7(X) returns bits 0...6 of CELL_TYPE (X) |
| 251 | * |
| 252 | * Sometimes we choose the bottom seven bits carefully, |
| 253 | * so that the 2-valued bit (called S bit) can be masked |
| 254 | * off to reveal a common type. |
| 255 | * |
| 256 | * TYP7S(X) returns TYP7, but masking out the option bit S. |
| 257 | * |
| 258 | * Some TC7 types are subdivided into 256 subtypes giving |
| 259 | * rise to the macros: |
| 260 | * |
| 261 | * TYP16 |
| 262 | * TYP16S |
| 263 | * |
| 264 | * TYP16S functions similarly wrt to TYP16 as TYP7S to TYP7, |
| 265 | * but a different option bit is used (bit 2 for TYP7S, |
| 266 | * bit 8 for TYP16S). |
| 267 | * */ |
| 268 | |
| 269 | |
| 270 | |
| 271 | \f |
| 272 | /* {Non-immediate values.} |
| 273 | * |
| 274 | * If X is non-immediate, it is necessary to look at SCM_CAR (X) to |
| 275 | * figure out Xs type. X may be a cons pair, in which case the value |
| 276 | * SCM_CAR (x) will be either an immediate or non-immediate value. X |
| 277 | * may be something other than a cons pair, in which case the value |
| 278 | * SCM_CAR (x) will be a non-object value. |
| 279 | * |
| 280 | * All immediates and non-immediates have a 0 in bit 0. We |
| 281 | * additionally preserve the invariant that all non-object values |
| 282 | * stored in the SCM_CAR of a non-immediate object have a 1 in bit 1: |
| 283 | */ |
| 284 | |
| 285 | #define SCM_CONSP(x) (!SCM_IMP (x) && ((1 & SCM_CELL_TYPE (x)) == 0)) |
| 286 | #define SCM_NCONSP(x) (!SCM_CONSP (x)) |
| 287 | |
| 288 | \f |
| 289 | |
| 290 | /* See numbers.h for macros relating to immediate integers. |
| 291 | */ |
| 292 | |
| 293 | #define SCM_ITAG3(x) (7 & SCM_UNPACK (x)) |
| 294 | #define SCM_TYP3(x) (7 & SCM_CELL_TYPE (x)) |
| 295 | #define scm_tc3_cons 0 |
| 296 | #define scm_tc3_struct 1 |
| 297 | #define scm_tc3_int_1 2 |
| 298 | #define scm_tc3_closure 3 |
| 299 | #define scm_tc3_imm24 4 |
| 300 | #define scm_tc3_tc7_1 5 |
| 301 | #define scm_tc3_int_2 6 |
| 302 | #define scm_tc3_tc7_2 7 |
| 303 | |
| 304 | |
| 305 | /* |
| 306 | * Do not change the three bit tags. |
| 307 | */ |
| 308 | |
| 309 | |
| 310 | #define SCM_ITAG7(x) (127 & SCM_UNPACK (x)) |
| 311 | #define SCM_TYP7(x) (0x7f & SCM_CELL_TYPE (x)) |
| 312 | #define SCM_TYP7S(x) ((0x7f & ~2) & SCM_CELL_TYPE (x)) |
| 313 | |
| 314 | |
| 315 | #define SCM_TYP16(x) (0xffff & SCM_CELL_TYPE (x)) |
| 316 | #define SCM_TYP16S(x) (0xfeff & SCM_CELL_TYPE (x)) |
| 317 | |
| 318 | #define SCM_TYP16_PREDICATE(tag,x) (!SCM_IMP (x) && SCM_TYP16 (x) == (tag)) |
| 319 | |
| 320 | \f |
| 321 | |
| 322 | #define scm_tc7_symbol 5 |
| 323 | #define scm_tc7_variable 7 |
| 324 | |
| 325 | /* couple */ |
| 326 | #define scm_tc7_vector 13 |
| 327 | #define scm_tc7_wvect 15 |
| 328 | |
| 329 | #define scm_tc7_string 21 |
| 330 | /* free 23 */ |
| 331 | |
| 332 | /* Many of the following should be turned |
| 333 | * into structs or smobs. We need back some |
| 334 | * of these 7 bit tags! |
| 335 | */ |
| 336 | #define scm_tc7_pws 31 |
| 337 | |
| 338 | #ifdef HAVE_ARRAYS |
| 339 | #define scm_tc7_llvect 29 |
| 340 | #define scm_tc7_uvect 37 |
| 341 | /* free 39 */ |
| 342 | #define scm_tc7_fvect 45 |
| 343 | #define scm_tc7_dvect 47 |
| 344 | #define scm_tc7_cvect 53 |
| 345 | #define scm_tc7_svect 55 |
| 346 | #define scm_tc7_bvect 71 |
| 347 | #define scm_tc7_byvect 77 |
| 348 | #define scm_tc7_ivect 79 |
| 349 | #endif |
| 350 | |
| 351 | /* free 61 */ |
| 352 | #define scm_tc7_cclo 63 |
| 353 | #define scm_tc7_rpsubr 69 |
| 354 | #define scm_tc7_subr_0 85 |
| 355 | #define scm_tc7_subr_1 87 |
| 356 | #define scm_tc7_cxr 93 |
| 357 | #define scm_tc7_subr_3 95 |
| 358 | #define scm_tc7_subr_2 101 |
| 359 | #define scm_tc7_asubr 103 |
| 360 | #define scm_tc7_subr_1o 109 |
| 361 | #define scm_tc7_subr_2o 111 |
| 362 | #define scm_tc7_lsubr_2 117 |
| 363 | #define scm_tc7_lsubr 119 |
| 364 | |
| 365 | |
| 366 | /* There are 256 port subtypes. |
| 367 | */ |
| 368 | #define scm_tc7_port 125 |
| 369 | |
| 370 | |
| 371 | /* There are 256 smob subtypes. Here are the first four. |
| 372 | */ |
| 373 | |
| 374 | #define scm_tc7_smob 127 /* DO NOT CHANGE [**] */ |
| 375 | |
| 376 | /* [**] If you change scm_tc7_smob, you must also change |
| 377 | * the places it is hard coded in this file and possibly others. |
| 378 | */ |
| 379 | |
| 380 | |
| 381 | /* scm_tc_free_cell is also the 0th smob type. We place this |
| 382 | * in free cells to tell the conservative marker not to trace it. |
| 383 | */ |
| 384 | #define scm_tc_free_cell (scm_tc7_smob + 0 * 256L) |
| 385 | |
| 386 | /* Smob type 1 to 3 (note the dependency on the predicate SCM_NUMP) |
| 387 | */ |
| 388 | #define scm_tc16_big (scm_tc7_smob + 1 * 256L) |
| 389 | #define scm_tc16_real (scm_tc7_smob + 2 * 256L) |
| 390 | #define scm_tc16_complex (scm_tc7_smob + 3 * 256L) |
| 391 | |
| 392 | \f |
| 393 | /* {Immediate Values} |
| 394 | */ |
| 395 | |
| 396 | enum scm_tags |
| 397 | { |
| 398 | scm_tc8_char = 0xf4, |
| 399 | scm_tc8_iloc = 0xfc |
| 400 | }; |
| 401 | |
| 402 | #define SCM_ITAG8(X) (SCM_UNPACK (X) & 0xff) |
| 403 | #define SCM_MAKE_ITAG8(X, TAG) SCM_PACK (((X) << 8) + TAG) |
| 404 | #define SCM_ITAG8_DATA(X) (SCM_UNPACK (X) >> 8) |
| 405 | |
| 406 | |
| 407 | \f |
| 408 | /* Immediate Symbols, Special Symbols, Flags (various constants). |
| 409 | */ |
| 410 | |
| 411 | /* SCM_ISYMP tests for ISPCSYM and ISYM */ |
| 412 | #define SCM_ISYMP(n) ((0x187 & SCM_UNPACK (n)) == 4) |
| 413 | |
| 414 | /* SCM_IFLAGP tests for ISPCSYM, ISYM and IFLAG */ |
| 415 | #define SCM_IFLAGP(n) ((0x87 & SCM_UNPACK (n)) == 4) |
| 416 | #define SCM_ISYMNUM(n) (SCM_UNPACK (n) >> 9) |
| 417 | #define SCM_ISYMCHARS(n) (scm_isymnames[SCM_ISYMNUM (n)]) |
| 418 | #define SCM_MAKSPCSYM(n) SCM_PACK (((n) << 9) + ((n) << 3) + 4L) |
| 419 | #define SCM_MAKISYM(n) SCM_PACK (((n) << 9) + 0x74L) |
| 420 | #define SCM_MAKIFLAG(n) SCM_PACK (((n) << 9) + 0x174L) |
| 421 | |
| 422 | SCM_API char *scm_isymnames[]; /* defined in print.c */ |
| 423 | |
| 424 | /* This table must agree with the declarations |
| 425 | * in repl.c: {Names of immediate symbols}. |
| 426 | * |
| 427 | * These are used only in eval but their values |
| 428 | * have to be allocated here. |
| 429 | * |
| 430 | */ |
| 431 | |
| 432 | #define SCM_IM_AND SCM_MAKSPCSYM (0) |
| 433 | #define SCM_IM_BEGIN SCM_MAKSPCSYM (1) |
| 434 | #define SCM_IM_CASE SCM_MAKSPCSYM (2) |
| 435 | #define SCM_IM_COND SCM_MAKSPCSYM (3) |
| 436 | #define SCM_IM_DO SCM_MAKSPCSYM (4) |
| 437 | #define SCM_IM_IF SCM_MAKSPCSYM (5) |
| 438 | #define SCM_IM_LAMBDA SCM_MAKSPCSYM (6) |
| 439 | #define SCM_IM_LET SCM_MAKSPCSYM (7) |
| 440 | #define SCM_IM_LETSTAR SCM_MAKSPCSYM (8) |
| 441 | #define SCM_IM_LETREC SCM_MAKSPCSYM (9) |
| 442 | #define SCM_IM_OR SCM_MAKSPCSYM (10) |
| 443 | #define SCM_IM_QUOTE SCM_MAKSPCSYM (11) |
| 444 | #define SCM_IM_SET_X SCM_MAKSPCSYM (12) |
| 445 | #define SCM_IM_DEFINE SCM_MAKSPCSYM (13) |
| 446 | #define SCM_IM_APPLY SCM_MAKISYM (14) |
| 447 | #define SCM_IM_CONT SCM_MAKISYM (15) |
| 448 | #define SCM_BOOL_F SCM_MAKIFLAG (16) |
| 449 | #define SCM_BOOL_T SCM_MAKIFLAG (17) |
| 450 | #define SCM_UNDEFINED SCM_MAKIFLAG (18) |
| 451 | #define SCM_EOF_VAL SCM_MAKIFLAG (19) |
| 452 | #define SCM_EOL SCM_MAKIFLAG (20) |
| 453 | #define SCM_UNSPECIFIED SCM_MAKIFLAG (21) |
| 454 | #define SCM_IM_DISPATCH SCM_MAKISYM (22) |
| 455 | #define SCM_IM_SLOT_REF SCM_MAKISYM (23) |
| 456 | #define SCM_IM_SLOT_SET_X SCM_MAKISYM (24) |
| 457 | |
| 458 | /* Multi-language support */ |
| 459 | |
| 460 | #define SCM_IM_NIL_COND SCM_MAKISYM (25) |
| 461 | #define SCM_IM_NIL_IFY SCM_MAKISYM (26) |
| 462 | #define SCM_IM_T_IFY SCM_MAKISYM (27) |
| 463 | #define SCM_IM_0_COND SCM_MAKISYM (28) |
| 464 | #define SCM_IM_0_IFY SCM_MAKISYM (29) |
| 465 | #define SCM_IM_1_IFY SCM_MAKISYM (30) |
| 466 | #define SCM_IM_BIND SCM_MAKISYM (31) |
| 467 | |
| 468 | #define SCM_IM_DELAY SCM_MAKISYM (32) |
| 469 | #define SCM_IM_CALL_WITH_VALUES SCM_MAKISYM (33) |
| 470 | |
| 471 | /* When a variable is unbound this is marked by the SCM_UNDEFINED |
| 472 | * value. The following is an unbound value which can be handled on |
| 473 | * the Scheme level, i.e., it can be stored in and retrieved from a |
| 474 | * Scheme variable. This value is only intended to mark an unbound |
| 475 | * slot in GOOPS. It is needed now, but we should probably rewrite |
| 476 | * the code which handles this value in C so that SCM_UNDEFINED can be |
| 477 | * used instead. It is not ideal to let this kind of unique and |
| 478 | * strange values loose on the Scheme level. |
| 479 | */ |
| 480 | #define SCM_UNBOUND SCM_MAKIFLAG (34) |
| 481 | |
| 482 | #define SCM_UNBNDP(x) (SCM_EQ_P ((x), SCM_UNDEFINED)) |
| 483 | |
| 484 | \f |
| 485 | |
| 486 | /* Dispatching aids: |
| 487 | |
| 488 | When switching on SCM_TYP7 of a SCM value, use these fake case |
| 489 | labels to catch types that use fewer than 7 bits for tagging. */ |
| 490 | |
| 491 | /* For cons pairs with immediate values in the CAR |
| 492 | */ |
| 493 | |
| 494 | #define scm_tcs_cons_imcar 2:case 4:case 6:case 10:\ |
| 495 | case 12:case 14:case 18:case 20:\ |
| 496 | case 22:case 26:case 28:case 30:\ |
| 497 | case 34:case 36:case 38:case 42:\ |
| 498 | case 44:case 46:case 50:case 52:\ |
| 499 | case 54:case 58:case 60:case 62:\ |
| 500 | case 66:case 68:case 70:case 74:\ |
| 501 | case 76:case 78:case 82:case 84:\ |
| 502 | case 86:case 90:case 92:case 94:\ |
| 503 | case 98:case 100:case 102:case 106:\ |
| 504 | case 108:case 110:case 114:case 116:\ |
| 505 | case 118:case 122:case 124:case 126 |
| 506 | |
| 507 | /* For cons pairs with non-immediate values in the SCM_CAR |
| 508 | */ |
| 509 | #define scm_tcs_cons_nimcar 0:case 8:case 16:case 24:\ |
| 510 | case 32:case 40:case 48:case 56:\ |
| 511 | case 64:case 72:case 80:case 88:\ |
| 512 | case 96:case 104:case 112:case 120 |
| 513 | |
| 514 | /* For structs |
| 515 | */ |
| 516 | #define scm_tcs_struct 1:case 9:case 17:case 25:\ |
| 517 | case 33:case 41:case 49:case 57:\ |
| 518 | case 65:case 73:case 81:case 89:\ |
| 519 | case 97:case 105:case 113:case 121 |
| 520 | |
| 521 | /* For closures |
| 522 | */ |
| 523 | #define scm_tcs_closures 3:case 11:case 19:case 27:\ |
| 524 | case 35:case 43:case 51:case 59:\ |
| 525 | case 67:case 75:case 83:case 91:\ |
| 526 | case 99:case 107:case 115:case 123 |
| 527 | |
| 528 | /* For subrs |
| 529 | */ |
| 530 | #define scm_tcs_subrs scm_tc7_asubr:case scm_tc7_subr_0:case scm_tc7_subr_1:case scm_tc7_cxr:\ |
| 531 | case scm_tc7_subr_3:case scm_tc7_subr_2:case scm_tc7_rpsubr:case scm_tc7_subr_1o:\ |
| 532 | case scm_tc7_subr_2o:case scm_tc7_lsubr_2:case scm_tc7_lsubr |
| 533 | |
| 534 | \f |
| 535 | |
| 536 | #if (SCM_ENABLE_DEPRECATED == 1) |
| 537 | |
| 538 | #define SCM_CELLP(x) (((sizeof (scm_cell) - 1) & SCM_UNPACK (x)) == 0) |
| 539 | #define SCM_NCELLP(x) (!SCM_CELLP (x)) |
| 540 | |
| 541 | #endif |
| 542 | |
| 543 | #endif /* SCM_TAGS_H */ |
| 544 | |
| 545 | /* |
| 546 | Local Variables: |
| 547 | c-file-style: "gnu" |
| 548 | End: |
| 549 | */ |