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0f2d19dd JB |
1 | /* classes: h_files */ |
2 | ||
22a52da1 DH |
3 | #ifndef SCM_TAGS_H |
4 | #define SCM_TAGS_H | |
8c494e99 | 5 | |
2fb924f6 | 6 | /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2008,2009 |
5065b40d | 7 | * Free Software Foundation, Inc. |
8ce94504 | 8 | * |
73be1d9e | 9 | * This library is free software; you can redistribute it and/or |
53befeb7 NJ |
10 | * modify it under the terms of the GNU Lesser General Public License |
11 | * as published by the Free Software Foundation; either version 3 of | |
12 | * the License, or (at your option) any later version. | |
8ce94504 | 13 | * |
53befeb7 NJ |
14 | * This library is distributed in the hope that it will be useful, but |
15 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
73be1d9e MV |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
17 | * Lesser General Public License for more details. | |
8ce94504 | 18 | * |
73be1d9e MV |
19 | * You should have received a copy of the GNU Lesser General Public |
20 | * License along with this library; if not, write to the Free Software | |
53befeb7 NJ |
21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
22 | * 02110-1301 USA | |
73be1d9e | 23 | */ |
1bbd0b84 | 24 | |
0f2d19dd JB |
25 | \f |
26 | ||
8ce94504 | 27 | /** This file defines the format of SCM values and cons pairs. |
0f2d19dd JB |
28 | ** It is here that tag bits are assigned for various purposes. |
29 | **/ | |
30 | ||
353d4770 RB |
31 | /* picks up scmconfig.h too */ |
32 | #include "libguile/__scm.h" | |
0f2d19dd | 33 | |
ee89863b KR |
34 | #if HAVE_INTTYPES_H |
35 | # include <inttypes.h> /* for INTPTR_MAX and friends */ | |
36 | #else | |
37 | # if HAVE_STDINT_H | |
38 | # include <stdint.h> /* for INTPTR_MAX and friends */ | |
39 | # endif | |
40 | #endif | |
41 | ||
7e3b25bf DH |
42 | \f |
43 | ||
0f2d19dd | 44 | /* In the beginning was the Word: |
7e3b25bf DH |
45 | * |
46 | * For the representation of scheme objects and their handling, Guile provides | |
47 | * two types: scm_t_bits and SCM. | |
48 | * | |
49 | * - scm_t_bits values can hold bit patterns of non-objects and objects: | |
50 | * | |
51 | * Non-objects -- in this case the value may not be changed into a SCM value | |
52 | * in any way. | |
53 | * | |
54 | * Objects -- in this case the value may be changed into a SCM value using | |
55 | * the SCM_PACK macro. | |
56 | * | |
57 | * - SCM values can hold proper scheme objects only. They can be changed into | |
58 | * a scm_t_bits value using the SCM_UNPACK macro. | |
59 | * | |
60 | * When working in the domain of scm_t_bits values, programmers must keep | |
61 | * track of any scm_t_bits value they create that is not a proper scheme | |
62 | * object. This makes sure that in the domain of SCM values developers can | |
63 | * rely on the fact that they are dealing with proper scheme objects only. | |
64 | * Thus, the distinction between scm_t_bits and SCM values helps to identify | |
65 | * those parts of the code where special care has to be taken not to create | |
66 | * bad SCM values. | |
67 | */ | |
68 | ||
69 | /* For dealing with the bit level representation of scheme objects we define | |
70 | * scm_t_bits: | |
0f2d19dd | 71 | */ |
23c96d9b KR |
72 | /* On Solaris 7 and 8, /usr/include/sys/int_limits.h defines |
73 | INTPTR_MAX and UINTPTR_MAX to empty, INTPTR_MIN is not defined. | |
74 | To avoid uintptr_t and intptr_t in this case we require | |
75 | UINTPTR_MAX-0 != 0 etc. */ | |
76 | #if SCM_SIZEOF_INTPTR_T != 0 && defined(INTPTR_MAX) && defined(INTPTR_MIN) \ | |
77 | && INTPTR_MAX-0 != 0 && INTPTR_MIN-0 != 0 \ | |
78 | && SCM_SIZEOF_UINTPTR_T != 0 && defined(UINTPTR_MAX) && UINTPTR_MAX-0 != 0 | |
79 | ||
f59195a1 | 80 | typedef intptr_t scm_t_signed_bits; |
004c0902 MV |
81 | #define SCM_T_SIGNED_BITS_MAX INTPTR_MAX |
82 | #define SCM_T_SIGNED_BITS_MIN INTPTR_MIN | |
353d4770 RB |
83 | typedef uintptr_t scm_t_bits; |
84 | #define SIZEOF_SCM_T_BITS SCM_SIZEOF_UINTPTR_T | |
85 | #define SCM_T_BITS_MAX UINTPTR_MAX | |
23c96d9b | 86 | |
353d4770 | 87 | #else |
23c96d9b KR |
88 | |
89 | typedef signed long scm_t_signed_bits; | |
90 | #define SCM_T_SIGNED_BITS_MAX LONG_MAX | |
91 | #define SCM_T_SIGNED_BITS_MIN LONG_MIN | |
353d4770 RB |
92 | typedef unsigned long scm_t_bits; |
93 | #define SIZEOF_SCM_T_BITS SCM_SIZEOF_UNSIGNED_LONG | |
94 | #define SCM_T_BITS_MAX ULONG_MAX | |
23c96d9b | 95 | |
353d4770 RB |
96 | #endif |
97 | ||
7e3b25bf DH |
98 | /* But as external interface, we define SCM, which may, according to the |
99 | * desired level of type checking, be defined in several ways: | |
8d3356e7 | 100 | */ |
729dbac3 | 101 | #if (SCM_DEBUG_TYPING_STRICTNESS == 2) |
92c2555f MV |
102 | typedef union { struct { scm_t_bits n; } n; } SCM; |
103 | static SCM scm_pack(scm_t_bits b) { SCM s; s.n.n = b; return s; } | |
076d6063 | 104 | # define SCM_UNPACK(x) ((x).n.n) |
92c2555f | 105 | # define SCM_PACK(x) (scm_pack ((scm_t_bits) (x))) |
729dbac3 | 106 | #elif (SCM_DEBUG_TYPING_STRICTNESS == 1) |
8d3356e7 DH |
107 | /* This is the default, which provides an intermediate level of compile time |
108 | * type checking while still resulting in very efficient code. | |
c209c88e | 109 | */ |
729dbac3 | 110 | typedef struct scm_unused_struct * SCM; |
702551e6 HWN |
111 | |
112 | /* | |
113 | The 0?: constructions makes sure that the code is never executed, | |
114 | and that there is no performance hit. However, the alternative is | |
115 | compiled, and does generate a warning when used with the wrong | |
116 | pointer type. | |
95c6523b LC |
117 | |
118 | The Tru64 and ia64-hp-hpux11.23 compilers fail on `case (0?0=0:x)' | |
119 | statements, so for them type-checking is disabled. */ | |
120 | #if defined __DECC || defined __HP_cc | |
121 | # define SCM_UNPACK(x) ((scm_t_bits) (x)) | |
122 | #else | |
702551e6 | 123 | # define SCM_UNPACK(x) ((scm_t_bits) (0? (*(SCM*)0=(x)): x)) |
95c6523b | 124 | #endif |
702551e6 HWN |
125 | |
126 | /* | |
127 | There is no typechecking on SCM_PACK, since all kinds of types | |
128 | (unsigned long, void*) go in SCM_PACK | |
129 | */ | |
076d6063 | 130 | # define SCM_PACK(x) ((SCM) (x)) |
702551e6 | 131 | |
c209c88e | 132 | #else |
8d3356e7 DH |
133 | /* This should be used as a fall back solution for machines on which casting |
134 | * to a pointer may lead to loss of bit information, e. g. in the three least | |
135 | * significant bits. | |
136 | */ | |
92c2555f | 137 | typedef scm_t_bits SCM; |
076d6063 | 138 | # define SCM_UNPACK(x) (x) |
702551e6 | 139 | # define SCM_PACK(x) ((SCM) (x)) |
c209c88e | 140 | #endif |
0f2d19dd | 141 | |
8d3356e7 DH |
142 | |
143 | /* SCM values can not be compared by using the operator ==. Use the following | |
144 | * macro instead, which is the equivalent of the scheme predicate 'eq?'. | |
145 | */ | |
9c293a3d | 146 | #define scm_is_eq(x, y) (SCM_UNPACK (x) == SCM_UNPACK (y)) |
8d3356e7 | 147 | |
0f2d19dd | 148 | \f |
2549a709 | 149 | |
7e3b25bf DH |
150 | /* Representation of scheme objects: |
151 | * | |
152 | * Guile's type system is designed to work on systems where scm_t_bits and SCM | |
153 | * variables consist of at least 32 bits. The objects that a SCM variable can | |
154 | * represent belong to one of the following two major categories: | |
155 | * | |
156 | * - Immediates -- meaning that the SCM variable contains an entire Scheme | |
157 | * object. That means, all the object's data (including the type tagging | |
158 | * information that is required to identify the object's type) must fit into | |
159 | * 32 bits. | |
160 | * | |
161 | * - Non-immediates -- meaning that the SCM variable holds a pointer into the | |
162 | * heap of cells (see below). On systems where a pointer needs more than 32 | |
163 | * bits this means that scm_t_bits and SCM variables need to be large enough | |
164 | * to hold such pointers. In contrast to immediates, the object's data of | |
165 | * a non-immediate can consume arbitrary amounts of memory: The heap cell | |
166 | * being pointed to consists of at least two scm_t_bits variables and thus | |
167 | * can be used to hold pointers to malloc'ed memory of any size. | |
168 | * | |
169 | * The 'heap' is the memory area that is under control of Guile's garbage | |
170 | * collector. It holds 'single-cells' or 'double-cells', which consist of | |
171 | * either two or four scm_t_bits variables, respectively. It is guaranteed | |
172 | * that the address of a cell on the heap is 8-byte aligned. That is, since | |
173 | * non-immediates hold a cell address, the three least significant bits of a | |
174 | * non-immediate can be used to store additional information. The bits are | |
175 | * used to store information about the object's type and thus are called | |
176 | * tc3-bits, where tc stands for type-code. | |
177 | * | |
178 | * For a given SCM value, the distinction whether it holds an immediate or | |
179 | * non-immediate object is based on the tc3-bits (see above) of its scm_t_bits | |
180 | * equivalent: If the tc3-bits equal #b000, then the SCM value holds a | |
181 | * non-immediate, and the scm_t_bits variable's value is just the pointer to | |
182 | * the heap cell. | |
183 | * | |
184 | * Summarized, the data of a scheme object that is represented by a SCM | |
185 | * variable consists of a) the SCM variable itself, b) in case of | |
186 | * non-immediates the data of the single-cell or double-cell the SCM object | |
187 | * points to, c) in case of non-immediates potentially additional data outside | |
188 | * of the heap (like for example malloc'ed data), and d) in case of | |
189 | * non-immediates potentially additional data inside of the heap, since data | |
190 | * stored in b) and c) may hold references to other cells. | |
191 | * | |
192 | * | |
193 | * Immediates | |
194 | * | |
195 | * Operations on immediate objects can typically be processed faster than on | |
196 | * non-immediates. The reason is that the object's data can be extracted | |
197 | * directly from the SCM variable (or rather a corresponding scm_t_bits | |
198 | * variable), instead of having to perform additional memory accesses to | |
199 | * obtain the object's data from the heap. In order to get the best possible | |
200 | * performance frequently used data types should be realized as immediates. | |
201 | * This is, as has been mentioned above, only possible if the objects can be | |
202 | * represented with 32 bits (including type tagging). | |
203 | * | |
204 | * In Guile, the following data types and special objects are realized as | |
205 | * immediates: booleans, characters, small integers (see below), the empty | |
206 | * list, the end of file object, the 'unspecified' object (which is delivered | |
207 | * as a return value by functions for which the return value is unspecified), | |
208 | * a 'nil' object used in the elisp-compatibility mode and certain other | |
209 | * 'special' objects which are only used internally in Guile. | |
210 | * | |
211 | * Integers in Guile can be arbitrarily large. On the other hand, integers | |
212 | * are one of the most frequently used data types. Especially integers with | |
213 | * less than 32 bits are commonly used. Thus, internally and transparently | |
214 | * for application code guile distinguishes between small and large integers. | |
215 | * Whether an integer is a large or a small integer depends on the number of | |
216 | * bits needed to represent its value. Small integers are those which can be | |
217 | * represented as immediates. Since they don't require more than a fixed | |
218 | * number of bits for their representation, they are also known as 'fixnums'. | |
219 | * | |
220 | * The tc3-combinations #b010 and #b110 are used to represent small integers, | |
221 | * which allows to use the most significant bit of the tc3-bits to be part of | |
222 | * the integer value being represented. This means that all integers with up | |
223 | * to 30 bits (including one bit for the sign) can be represented as | |
224 | * immediates. On systems where SCM and scm_t_bits variables hold more than | |
225 | * 32 bits, the amount of bits usable for small integers will even be larger. | |
226 | * The tc3-code #b100 is shared among booleans, characters and the other | |
227 | * special objects listed above. | |
228 | * | |
229 | * | |
230 | * Non-Immediates | |
231 | * | |
232 | * All object types not mentioned above in the list of immedate objects are | |
233 | * represented as non-immediates. Whether a non-immediate scheme object is | |
234 | * represented by a single-cell or a double-cell depends on the object's type, | |
235 | * namely on the set of attributes that have to be stored with objects of that | |
236 | * type. Every non-immediate type is allowed to define its own layout and | |
237 | * interpretation of the data stored in its cell (with some restrictions, see | |
238 | * below). | |
239 | * | |
240 | * One of the design goals of guile's type system is to make it possible to | |
241 | * store a scheme pair with as little memory usage as possible. The minimum | |
242 | * amount of memory that is required to store two scheme objects (car and cdr | |
243 | * of a pair) is the amount of memory required by two scm_t_bits or SCM | |
244 | * variables. Therefore pairs in guile are stored in single-cells. | |
245 | * | |
246 | * Another design goal for the type system is to store procedure objects | |
247 | * created by lambda expresssions (closures) and class instances (goops | |
248 | * objects) with as little memory usage as possible. Closures are represented | |
249 | * by a reference to the function code and a reference to the closure's | |
250 | * environment. Class instances are represented by a reference to the | |
251 | * instance's class definition and a reference to the instance's data. Thus, | |
252 | * closures as well as class instances also can be stored in single-cells. | |
253 | * | |
254 | * Certain other non-immediate types also store their data in single-cells. | |
255 | * By design decision, the heap is split into areas for single-cells and | |
256 | * double-cells, but not into areas for single-cells-holding-pairs and areas | |
257 | * for single-cells-holding-non-pairs. Any single-cell on the heap therefore | |
258 | * can hold pairs (consisting of two scm_t_bits variables representing two | |
259 | * scheme objects - the car and cdr of the pair) and non-pairs (consisting of | |
260 | * two scm_t_bits variables that hold bit patterns as defined by the layout of | |
261 | * the corresponding object's type). | |
262 | * | |
263 | * | |
264 | * Garbage collection | |
265 | * | |
266 | * During garbage collection, unreachable cells on the heap will be freed. | |
267 | * That is, the garbage collector will detect cells which have no SCM variable | |
268 | * pointing towards them. In order to properly release all memory belonging | |
269 | * to the object to which a cell belongs, the gc needs to be able to interpret | |
270 | * the cell contents in the correct way. That means that the gc needs to be | |
271 | * able to determine the object type associated with a cell only from the cell | |
272 | * itself. | |
273 | * | |
274 | * Consequently, if the gc detects an unreachable single-cell, those two | |
275 | * scm_t_bits variables must provide enough information to determine whether | |
276 | * they belong to a pair (i. e. both scm_t_bits variables represent valid | |
277 | * scheme objects), to a closure, a class instance or if they belong to any | |
278 | * other non-immediate. Guile's type system is designed to make it possible | |
279 | * to determine a the type to which a cell belongs in the majority of cases | |
280 | * from the cell's first scm_t_bits variable. (Given a SCM variable X holding | |
281 | * a non-immediate object, the macro SCM_CELL_TYPE(X) will deliver the | |
282 | * corresponding cell's first scm_t_bits variable.) | |
283 | * | |
284 | * If the cell holds a scheme pair, then we already know that the first | |
285 | * scm_t_bits variable of the cell will hold a scheme object with one of the | |
286 | * following tc3-codes: #b000 (non-immediate), #b010 (small integer), #b100 | |
287 | * (small integer), #b110 (non-integer immediate). All these tc3-codes have | |
288 | * in common, that their least significant bit is #b0. This fact is used by | |
289 | * the garbage collector to identify cells that hold pairs. The remaining | |
290 | * tc3-codes are assigned as follows: #b001 (class instance or, more | |
291 | * precisely, a struct, of which a class instance is a special case), #b011 | |
292 | * (closure), #b101/#b111 (all remaining non-immediate types). | |
293 | * | |
294 | * | |
295 | * Summary of type codes of scheme objects (SCM variables) | |
296 | * | |
297 | * Here is a summary of tagging bits as they might occur in a scheme object. | |
298 | * The notation is as follows: tc stands for type code as before, tc<n> with n | |
299 | * being a number indicates a type code formed by the n least significant bits | |
300 | * of the SCM variables corresponding scm_t_bits value. | |
301 | * | |
302 | * Note that (as has been explained above) tc1==1 can only occur in the first | |
303 | * scm_t_bits variable of a cell belonging to a non-immediate object that is | |
304 | * not a pair. For an explanation of the tc tags with tc1==1, see the next | |
305 | * section with the summary of the type codes on the heap. | |
306 | * | |
307 | * tc1: | |
308 | * 0: For scheme objects, tc1==0 must be fulfilled. | |
309 | * (1: This can never be the case for a scheme object.) | |
310 | * | |
311 | * tc2: | |
312 | * 00: Either a non-immediate or some non-integer immediate | |
313 | * (01: This can never be the case for a scheme object.) | |
314 | * 10: Small integer | |
315 | * (11: This can never be the case for a scheme object.) | |
316 | * | |
317 | * tc3: | |
318 | * 000: a non-immediate object (pair, closure, class instance etc.) | |
319 | * (001: This can never be the case for a scheme object.) | |
320 | * 010: an even small integer (least significant bit is 0). | |
321 | * (011: This can never be the case for a scheme object.) | |
322 | * 100: Non-integer immediate | |
323 | * (101: This can never be the case for a scheme object.) | |
324 | * 110: an odd small integer (least significant bit is 1). | |
325 | * (111: This can never be the case for a scheme object.) | |
326 | * | |
327 | * The remaining bits of the non-immediate objects form the pointer to the | |
328 | * heap cell. The remaining bits of the small integers form the integer's | |
329 | * value and sign. Thus, the only scheme objects for which a further | |
330 | * subdivision is of interest are the ones with tc3==100. | |
331 | * | |
5065b40d DH |
332 | * tc8 (for objects with tc3==100): |
333 | * 00000-100: special objects ('flags') | |
334 | * 00001-100: characters | |
36245b66 DH |
335 | * 00010-100: evaluator byte codes ('isyms') |
336 | * 00011-100: evaluator byte codes ('ilocs') | |
7e3b25bf DH |
337 | * |
338 | * | |
339 | * Summary of type codes on the heap | |
340 | * | |
341 | * Here is a summary of tagging in scm_t_bits values as they might occur in | |
342 | * the first scm_t_bits variable of a heap cell. | |
343 | * | |
344 | * tc1: | |
345 | * 0: the cell belongs to a pair. | |
346 | * 1: the cell belongs to a non-pair. | |
347 | * | |
348 | * tc2: | |
349 | * 00: the cell belongs to a pair with no short integer in its car. | |
350 | * 01: the cell belongs to a non-pair (struct or some other non-immediate). | |
351 | * 10: the cell belongs to a pair with a short integer in its car. | |
352 | * 11: the cell belongs to a non-pair (closure or some other non-immediate). | |
353 | * | |
354 | * tc3: | |
355 | * 000: the cell belongs to a pair with a non-immediate in its car. | |
356 | * 001: the cell belongs to a struct | |
357 | * 010: the cell belongs to a pair with an even short integer in its car. | |
358 | * 011: the cell belongs to a closure | |
359 | * 100: the cell belongs to a pair with a non-integer immediate in its car. | |
360 | * 101: the cell belongs to some other non-immediate. | |
361 | * 110: the cell belongs to a pair with an odd short integer in its car. | |
362 | * 111: the cell belongs to some other non-immediate. | |
363 | * | |
364 | * tc7 (for tc3==1x1): | |
365 | * See below for the list of types. Note the special case of scm_tc7_vector | |
366 | * and scm_tc7_wvect: vectors and weak vectors are treated the same in many | |
367 | * cases. Thus, their tc7-codes are chosen to only differ in one bit. This | |
368 | * makes it possible to check an object at the same time for being a vector | |
369 | * or a weak vector by comparing its tc7 code with that bit masked (using | |
534c55a9 DH |
370 | * the TYP7S macro). Three more special tc7-codes are of interest: |
371 | * numbers, ports and smobs in fact each represent collections of types, | |
372 | * which are subdivided using tc16-codes. | |
7e3b25bf DH |
373 | * |
374 | * tc16 (for tc7==scm_tc7_smob): | |
375 | * The largest part of the space of smob types is not subdivided in a | |
376 | * predefined way, since smobs can be added arbitrarily by user C code. | |
377 | * However, while Guile also defines a number of smob types throughout, | |
534c55a9 DH |
378 | * there is one smob type, namely scm_tc_free_cell, for which Guile assumes |
379 | * that it is declared first and thus gets a known-in-advance tc16-code. | |
380 | * The reason of requiring a fixed tc16-code for this type is performance. | |
7e3b25bf | 381 | */ |
0f2d19dd | 382 | |
7e3b25bf DH |
383 | \f |
384 | ||
385 | /* Checking if a SCM variable holds an immediate or a non-immediate object: | |
386 | * This check can either be performed by checking for tc3==000 or tc3==00x, | |
387 | * since for a SCM variable it is known that tc1==0. */ | |
f1267706 | 388 | #define SCM_IMP(x) (6 & SCM_UNPACK (x)) |
76189127 | 389 | #define SCM_NIMP(x) (!SCM_IMP (x)) |
0f2d19dd | 390 | |
7e3b25bf DH |
391 | /* Checking if a SCM variable holds an immediate integer: See numbers.h for |
392 | * the definition of the following macros: SCM_I_FIXNUM_BIT, | |
e11e83f3 | 393 | * SCM_MOST_POSITIVE_FIXNUM, SCM_I_INUMP, SCM_I_MAKINUM, SCM_I_INUM. */ |
0f2d19dd | 394 | |
7e3b25bf DH |
395 | /* Checking if a SCM variable holds a pair (for historical reasons, in Guile |
396 | * also known as a cons-cell): This is done by first checking that the SCM | |
397 | * variable holds a non-immediate, and second, by checking that tc1==0 holds | |
6fcc7d48 MV |
398 | * for the SCM_CELL_TYPE of the SCM variable. |
399 | */ | |
400 | ||
401 | #define SCM_I_CONSP(x) (!SCM_IMP (x) && ((1 & SCM_CELL_TYPE (x)) == 0)) | |
0f2d19dd | 402 | |
0f2d19dd JB |
403 | \f |
404 | ||
7e3b25bf | 405 | /* Definitions for tc2: */ |
0f2d19dd | 406 | |
6375e040 DH |
407 | #define scm_tc2_int 2 |
408 | ||
7e3b25bf DH |
409 | |
410 | /* Definitions for tc3: */ | |
411 | ||
904a077d MV |
412 | #define SCM_ITAG3(x) (7 & SCM_UNPACK (x)) |
413 | #define SCM_TYP3(x) (7 & SCM_CELL_TYPE (x)) | |
7e3b25bf | 414 | |
904a077d MV |
415 | #define scm_tc3_cons 0 |
416 | #define scm_tc3_struct 1 | |
6375e040 | 417 | #define scm_tc3_int_1 (scm_tc2_int + 0) |
c209c88e GB |
418 | #define scm_tc3_closure 3 |
419 | #define scm_tc3_imm24 4 | |
420 | #define scm_tc3_tc7_1 5 | |
6375e040 | 421 | #define scm_tc3_int_2 (scm_tc2_int + 4) |
c209c88e | 422 | #define scm_tc3_tc7_2 7 |
0f2d19dd JB |
423 | |
424 | ||
7e3b25bf | 425 | /* Definitions for tc7: */ |
0f2d19dd | 426 | |
d1ca2c64 | 427 | #define SCM_ITAG7(x) (127 & SCM_UNPACK (x)) |
445f675c DH |
428 | #define SCM_TYP7(x) (0x7f & SCM_CELL_TYPE (x)) |
429 | #define SCM_TYP7S(x) ((0x7f & ~2) & SCM_CELL_TYPE (x)) | |
0f2d19dd | 430 | |
28b06554 | 431 | #define scm_tc7_symbol 5 |
e5aca4b5 | 432 | #define scm_tc7_variable 7 |
0f2d19dd JB |
433 | |
434 | /* couple */ | |
435 | #define scm_tc7_vector 13 | |
436 | #define scm_tc7_wvect 15 | |
437 | ||
0f2d19dd | 438 | #define scm_tc7_string 21 |
534c55a9 | 439 | #define scm_tc7_number 23 |
fddf6000 | 440 | #define scm_tc7_stringbuf 39 |
0f2d19dd JB |
441 | |
442 | /* Many of the following should be turned | |
443 | * into structs or smobs. We need back some | |
7e3b25bf DH |
444 | * of these 7 bit tags! */ |
445 | ||
37581b11 | 446 | #define scm_tc7_pws 31 |
afe5177e | 447 | |
067f0922 MV |
448 | #define scm_tc7_unused_1 29 |
449 | #define scm_tc7_unused_2 37 | |
450 | #define scm_tc7_unused_3 45 | |
451 | #define scm_tc7_unused_4 47 | |
452 | #define scm_tc7_unused_5 53 | |
453 | #define scm_tc7_unused_6 55 | |
6cf0f51d MV |
454 | #define scm_tc7_unused_7 71 |
455 | #define scm_tc7_unused_8 77 | |
afe5177e | 456 | |
14b18ed6 | 457 | #define scm_tc7_dsubr 61 |
e20d7001 | 458 | #define scm_tc7_gsubr 63 |
afe5177e | 459 | #define scm_tc7_rpsubr 69 |
2fb924f6 | 460 | #define scm_tc7_program 79 |
0f2d19dd JB |
461 | #define scm_tc7_subr_0 85 |
462 | #define scm_tc7_subr_1 87 | |
463 | #define scm_tc7_cxr 93 | |
464 | #define scm_tc7_subr_3 95 | |
465 | #define scm_tc7_subr_2 101 | |
466 | #define scm_tc7_asubr 103 | |
467 | #define scm_tc7_subr_1o 109 | |
468 | #define scm_tc7_subr_2o 111 | |
469 | #define scm_tc7_lsubr_2 117 | |
470 | #define scm_tc7_lsubr 119 | |
471 | ||
7e3b25bf | 472 | /* There are 256 port subtypes. */ |
0f2d19dd JB |
473 | #define scm_tc7_port 125 |
474 | ||
6375e040 DH |
475 | /* There are 256 smob subtypes. [**] If you change scm_tc7_smob, you must |
476 | * also change the places it is hard coded in this file and possibly others. | |
477 | * Dirk:FIXME:: Any hard coded reference to scm_tc7_smob must be replaced by a | |
7e3b25bf | 478 | * symbolic reference. */ |
0f2d19dd JB |
479 | #define scm_tc7_smob 127 /* DO NOT CHANGE [**] */ |
480 | ||
0f2d19dd | 481 | |
7e3b25bf DH |
482 | /* Definitions for tc16: */ |
483 | #define SCM_TYP16(x) (0xffff & SCM_CELL_TYPE (x)) | |
7e3b25bf DH |
484 | #define SCM_TYP16_PREDICATE(tag, x) (!SCM_IMP (x) && SCM_TYP16 (x) == (tag)) |
485 | ||
f03314f9 | 486 | |
534c55a9 | 487 | /* Here is the first smob subtype. */ |
0f2d19dd | 488 | |
6375e040 | 489 | /* scm_tc_free_cell is the 0th smob type. We place this in free cells to tell |
7e3b25bf | 490 | * the conservative marker not to trace it. */ |
8c921d5c | 491 | #define scm_tc_free_cell (scm_tc7_smob + 0 * 256L) |
0f2d19dd | 492 | |
0f2d19dd | 493 | \f |
5065b40d | 494 | |
8ce94504 | 495 | /* {Immediate Values} |
0f2d19dd JB |
496 | */ |
497 | ||
5065b40d | 498 | enum scm_tc8_tags |
0f2d19dd | 499 | { |
5065b40d DH |
500 | scm_tc8_flag = scm_tc3_imm24 + 0x00, /* special objects ('flags') */ |
501 | scm_tc8_char = scm_tc3_imm24 + 0x08, /* characters */ | |
502 | scm_tc8_isym = scm_tc3_imm24 + 0x10, /* evaluator byte codes ('isyms') */ | |
503 | scm_tc8_iloc = scm_tc3_imm24 + 0x18 /* evaluator byte codes ('ilocs') */ | |
0f2d19dd JB |
504 | }; |
505 | ||
f1267706 MD |
506 | #define SCM_ITAG8(X) (SCM_UNPACK (X) & 0xff) |
507 | #define SCM_MAKE_ITAG8(X, TAG) SCM_PACK (((X) << 8) + TAG) | |
508 | #define SCM_ITAG8_DATA(X) (SCM_UNPACK (X) >> 8) | |
0f2d19dd | 509 | |
0f2d19dd | 510 | \f |
0f2d19dd | 511 | |
5065b40d DH |
512 | /* Flags (special objects). The indices of the flags must agree with the |
513 | * declarations in print.c: iflagnames. */ | |
514 | ||
515 | #define SCM_IFLAGP(n) (SCM_ITAG8 (n) == scm_tc8_flag) | |
516 | #define SCM_MAKIFLAG(n) SCM_MAKE_ITAG8 ((n), scm_tc8_flag) | |
517 | #define SCM_IFLAGNUM(n) (SCM_ITAG8_DATA (n)) | |
e17d318f DH |
518 | |
519 | #define SCM_BOOL_F SCM_MAKIFLAG (0) | |
520 | #define SCM_BOOL_T SCM_MAKIFLAG (1) | |
521 | #define SCM_UNDEFINED SCM_MAKIFLAG (2) | |
522 | #define SCM_EOF_VAL SCM_MAKIFLAG (3) | |
523 | #define SCM_EOL SCM_MAKIFLAG (4) | |
524 | #define SCM_UNSPECIFIED SCM_MAKIFLAG (5) | |
525 | ||
526 | /* When a variable is unbound this is marked by the SCM_UNDEFINED | |
527 | * value. The following is an unbound value which can be handled on | |
528 | * the Scheme level, i.e., it can be stored in and retrieved from a | |
529 | * Scheme variable. This value is only intended to mark an unbound | |
530 | * slot in GOOPS. It is needed now, but we should probably rewrite | |
531 | * the code which handles this value in C so that SCM_UNDEFINED can be | |
532 | * used instead. It is not ideal to let this kind of unique and | |
533 | * strange values loose on the Scheme level. */ | |
534 | #define SCM_UNBOUND SCM_MAKIFLAG (6) | |
535 | ||
536 | /* The Elisp nil value. */ | |
537 | #define SCM_ELISP_NIL SCM_MAKIFLAG (7) | |
538 | ||
539 | ||
68fb32d2 | 540 | #define SCM_UNBNDP(x) (scm_is_eq ((x), SCM_UNDEFINED)) |
e17d318f | 541 | |
5065b40d | 542 | \f |
e17d318f | 543 | |
5065b40d DH |
544 | /* Evaluator byte codes ('immediate symbols'). These constants are used only |
545 | * in eval but their values have to be allocated here. The indices of the | |
546 | * SCM_IM_ symbols must agree with the declarations in print.c: | |
547 | * scm_isymnames. */ | |
0f2d19dd | 548 | |
5065b40d DH |
549 | #define SCM_ISYMP(n) (SCM_ITAG8 (n) == scm_tc8_isym) |
550 | #define SCM_MAKISYM(n) SCM_MAKE_ITAG8 ((n), scm_tc8_isym) | |
0f2d19dd | 551 | |
5065b40d DH |
552 | #define SCM_IM_AND SCM_MAKISYM (0) |
553 | #define SCM_IM_BEGIN SCM_MAKISYM (1) | |
554 | #define SCM_IM_CASE SCM_MAKISYM (2) | |
555 | #define SCM_IM_COND SCM_MAKISYM (3) | |
556 | #define SCM_IM_DO SCM_MAKISYM (4) | |
557 | #define SCM_IM_IF SCM_MAKISYM (5) | |
558 | #define SCM_IM_LAMBDA SCM_MAKISYM (6) | |
559 | #define SCM_IM_LET SCM_MAKISYM (7) | |
560 | #define SCM_IM_LETSTAR SCM_MAKISYM (8) | |
561 | #define SCM_IM_LETREC SCM_MAKISYM (9) | |
562 | #define SCM_IM_OR SCM_MAKISYM (10) | |
563 | #define SCM_IM_QUOTE SCM_MAKISYM (11) | |
564 | #define SCM_IM_SET_X SCM_MAKISYM (12) | |
22f2cf2d | 565 | #define SCM_IM_DEFINE SCM_MAKISYM (13) |
76189127 MD |
566 | #define SCM_IM_APPLY SCM_MAKISYM (14) |
567 | #define SCM_IM_CONT SCM_MAKISYM (15) | |
e17d318f DH |
568 | #define SCM_IM_DISPATCH SCM_MAKISYM (16) |
569 | #define SCM_IM_SLOT_REF SCM_MAKISYM (17) | |
570 | #define SCM_IM_SLOT_SET_X SCM_MAKISYM (18) | |
571 | #define SCM_IM_DELAY SCM_MAKISYM (19) | |
572 | #define SCM_IM_FUTURE SCM_MAKISYM (20) | |
573 | #define SCM_IM_CALL_WITH_VALUES SCM_MAKISYM (21) | |
2a6f7afe DH |
574 | #define SCM_IM_ELSE SCM_MAKISYM (22) |
575 | #define SCM_IM_ARROW SCM_MAKISYM (23) | |
5065b40d DH |
576 | #define SCM_IM_NIL_COND SCM_MAKISYM (24) /* Multi-language support */ |
577 | #define SCM_IM_BIND SCM_MAKISYM (25) /* Multi-language support */ | |
c96d76b8 | 578 | |
0f2d19dd JB |
579 | \f |
580 | ||
904a077d | 581 | /* Dispatching aids: |
0f2d19dd | 582 | |
904a077d MV |
583 | When switching on SCM_TYP7 of a SCM value, use these fake case |
584 | labels to catch types that use fewer than 7 bits for tagging. */ | |
0f2d19dd | 585 | |
8ce94504 | 586 | /* For cons pairs with immediate values in the CAR |
0f2d19dd JB |
587 | */ |
588 | ||
6375e040 DH |
589 | #define scm_tcs_cons_imcar \ |
590 | scm_tc2_int + 0: case scm_tc2_int + 4: case scm_tc3_imm24 + 0:\ | |
591 | case scm_tc2_int + 8: case scm_tc2_int + 12: case scm_tc3_imm24 + 8:\ | |
592 | case scm_tc2_int + 16: case scm_tc2_int + 20: case scm_tc3_imm24 + 16:\ | |
593 | case scm_tc2_int + 24: case scm_tc2_int + 28: case scm_tc3_imm24 + 24:\ | |
594 | case scm_tc2_int + 32: case scm_tc2_int + 36: case scm_tc3_imm24 + 32:\ | |
595 | case scm_tc2_int + 40: case scm_tc2_int + 44: case scm_tc3_imm24 + 40:\ | |
596 | case scm_tc2_int + 48: case scm_tc2_int + 52: case scm_tc3_imm24 + 48:\ | |
597 | case scm_tc2_int + 56: case scm_tc2_int + 60: case scm_tc3_imm24 + 56:\ | |
598 | case scm_tc2_int + 64: case scm_tc2_int + 68: case scm_tc3_imm24 + 64:\ | |
599 | case scm_tc2_int + 72: case scm_tc2_int + 76: case scm_tc3_imm24 + 72:\ | |
600 | case scm_tc2_int + 80: case scm_tc2_int + 84: case scm_tc3_imm24 + 80:\ | |
601 | case scm_tc2_int + 88: case scm_tc2_int + 92: case scm_tc3_imm24 + 88:\ | |
602 | case scm_tc2_int + 96: case scm_tc2_int + 100: case scm_tc3_imm24 + 96:\ | |
603 | case scm_tc2_int + 104: case scm_tc2_int + 108: case scm_tc3_imm24 + 104:\ | |
604 | case scm_tc2_int + 112: case scm_tc2_int + 116: case scm_tc3_imm24 + 112:\ | |
605 | case scm_tc2_int + 120: case scm_tc2_int + 124: case scm_tc3_imm24 + 120 | |
0f2d19dd JB |
606 | |
607 | /* For cons pairs with non-immediate values in the SCM_CAR | |
608 | */ | |
6375e040 DH |
609 | #define scm_tcs_cons_nimcar \ |
610 | scm_tc3_cons + 0:\ | |
611 | case scm_tc3_cons + 8:\ | |
612 | case scm_tc3_cons + 16:\ | |
613 | case scm_tc3_cons + 24:\ | |
614 | case scm_tc3_cons + 32:\ | |
615 | case scm_tc3_cons + 40:\ | |
616 | case scm_tc3_cons + 48:\ | |
617 | case scm_tc3_cons + 56:\ | |
618 | case scm_tc3_cons + 64:\ | |
619 | case scm_tc3_cons + 72:\ | |
620 | case scm_tc3_cons + 80:\ | |
621 | case scm_tc3_cons + 88:\ | |
622 | case scm_tc3_cons + 96:\ | |
623 | case scm_tc3_cons + 104:\ | |
624 | case scm_tc3_cons + 112:\ | |
625 | case scm_tc3_cons + 120 | |
0f2d19dd | 626 | |
904a077d | 627 | /* For structs |
0f2d19dd | 628 | */ |
6375e040 DH |
629 | #define scm_tcs_struct \ |
630 | scm_tc3_struct + 0:\ | |
631 | case scm_tc3_struct + 8:\ | |
632 | case scm_tc3_struct + 16:\ | |
633 | case scm_tc3_struct + 24:\ | |
634 | case scm_tc3_struct + 32:\ | |
635 | case scm_tc3_struct + 40:\ | |
636 | case scm_tc3_struct + 48:\ | |
637 | case scm_tc3_struct + 56:\ | |
638 | case scm_tc3_struct + 64:\ | |
639 | case scm_tc3_struct + 72:\ | |
640 | case scm_tc3_struct + 80:\ | |
641 | case scm_tc3_struct + 88:\ | |
642 | case scm_tc3_struct + 96:\ | |
643 | case scm_tc3_struct + 104:\ | |
644 | case scm_tc3_struct + 112:\ | |
645 | case scm_tc3_struct + 120 | |
0f2d19dd | 646 | |
904a077d MV |
647 | /* For closures |
648 | */ | |
6375e040 DH |
649 | #define scm_tcs_closures \ |
650 | scm_tc3_closure + 0:\ | |
651 | case scm_tc3_closure + 8:\ | |
652 | case scm_tc3_closure + 16:\ | |
653 | case scm_tc3_closure + 24:\ | |
654 | case scm_tc3_closure + 32:\ | |
655 | case scm_tc3_closure + 40:\ | |
656 | case scm_tc3_closure + 48:\ | |
657 | case scm_tc3_closure + 56:\ | |
658 | case scm_tc3_closure + 64:\ | |
659 | case scm_tc3_closure + 72:\ | |
660 | case scm_tc3_closure + 80:\ | |
661 | case scm_tc3_closure + 88:\ | |
662 | case scm_tc3_closure + 96:\ | |
663 | case scm_tc3_closure + 104:\ | |
664 | case scm_tc3_closure + 112:\ | |
665 | case scm_tc3_closure + 120 | |
0f2d19dd | 666 | |
904a077d MV |
667 | /* For subrs |
668 | */ | |
14b18ed6 DH |
669 | #define scm_tcs_subrs \ |
670 | scm_tc7_asubr:\ | |
671 | case scm_tc7_subr_0:\ | |
672 | case scm_tc7_subr_1:\ | |
673 | case scm_tc7_dsubr:\ | |
674 | case scm_tc7_cxr:\ | |
675 | case scm_tc7_subr_3:\ | |
676 | case scm_tc7_subr_2:\ | |
677 | case scm_tc7_rpsubr:\ | |
678 | case scm_tc7_subr_1o:\ | |
679 | case scm_tc7_subr_2o:\ | |
680 | case scm_tc7_lsubr_2:\ | |
e20d7001 LC |
681 | case scm_tc7_lsubr: \ |
682 | case scm_tc7_gsubr | |
0f2d19dd | 683 | |
f5f2dcff DH |
684 | \f |
685 | ||
8c494e99 | 686 | #if (SCM_ENABLE_DEPRECATED == 1) |
22a52da1 | 687 | |
228a24ef | 688 | #define SCM_CELLP(x) (((sizeof (scm_t_cell) - 1) & SCM_UNPACK (x)) == 0) |
8c494e99 | 689 | #define SCM_NCELLP(x) (!SCM_CELLP (x)) |
28b06554 | 690 | |
8c494e99 | 691 | #endif |
f5f2dcff | 692 | |
22a52da1 | 693 | #endif /* SCM_TAGS_H */ |
89e00824 ML |
694 | |
695 | /* | |
696 | Local Variables: | |
697 | c-file-style: "gnu" | |
698 | End: | |
699 | */ |