aboutsummaryrefslogtreecommitdiff
path: root/src/lobject.js
blob: fe04f23c70a22f3baa8dc2776835e6163f10a09b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
 /*jshint esversion: 6 */
"use strict";

const assert = require('assert');

const defs    = require('./defs.js');
const ljstype = require('./ljstype.js');
const luaconf = require('./luaconf.js');
const llimit  = require('./llimit.js');
const CT      = defs.constant_types;
const char    = defs.char;


class TValue {

    constructor(type, value) {
        this.type = type;
        this.value = value;
    }

    /* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */
    ttype() {
        return this.type & 0x3F;
    }

    /* type tag of a TValue with no variants (bits 0-3) */
    ttnov() {
        return this.type & 0x0F;
    }

    checktag(t) {
        return this.type === t;
    }

    checktype(t) {
        return this.ttnov() === t;
    }

    ttisnumber() {
        return this.checktype(CT.LUA_TNUMBER);
    }

    ttisfloat() {
        return this.checktag(CT.LUA_TNUMFLT);
    }

    ttisinteger() {
        return this.checktag(CT.LUA_TNUMINT);
    }

    ttisnil() {
        return this.checktag(CT.LUA_TNIL);
    }

    ttisboolean() {
        return this.checktag(CT.LUA_TBOOLEAN);
    }

    ttislightuserdata() {
        return this.checktag(CT.LUA_TLIGHTUSERDATA);
    }

    ttisstring() {
        return this.checktype(CT.LUA_TSTRING);
    }

    ttisshrstring() {
        return this.checktag(CT.LUA_TSHRSTR);
    }

    ttislngstring() {
        return this.checktag(CT.LUA_TLNGSTR);
    }

    ttistable() {
        return this.checktag(CT.LUA_TTABLE);
    }

    ttisfunction() {
        return this.checktype(CT.LUA_TFUNCTION);
    }

    ttisclosure() {
        return (this.type & 0x1F) === CT.LUA_TFUNCTION;
    }

    ttisCclosure() {
        return this.checktag(CT.LUA_TCCL);
    }

    ttisLclosure() {
        return this.checktag(CT.LUA_TLCL);
    }

    ttislcf() {
        return this.checktag(CT.LUA_TLCF);
    }

    ttisfulluserdata() {
        return this.checktag(CT.LUA_TUSERDATA);
    }

    ttisthread() {
        return this.checktag(CT.LUA_TTHREAD);
    }

    ttisdeadkey() {
        return this.checktag(CT.LUA_TDEADKEY);
    }

    l_isfalse() {
        return this.ttisnil() || (this.ttisboolean() && this.value === false);
    }

    setfltvalue(x) {
        this.type = CT.LUA_TNUMFLT;
        this.value = x;
    }

    setivalue(x) {
        this.type = CT.LUA_TNUMINT;
        this.value = x;
    }

    setnilvalue() {
        this.type = CT.LUA_TNIL;
        this.value = void 0;
    }

    setfvalue(x) {
        this.type = CT.LUA_TLCF;
        this.value = x;
    }

    setpvalue(x) {
        this.type = CT.LUA_TLIGHTUSERDATA;
        this.value = x;
    }

    setbvalue(x) {
        this.type = CT.LUA_TBOOLEAN;
        this.value = x;
    }

    sethvalue(x) {
        this.type = CT.LUA_TTABLE;
        this.value = x;
    }

    setfrom(tv) { /* in lua C source setobj2t is often used for this */
        this.type = tv.type;
        this.value = tv.value;
    }

    jsstring(from, to) {
        return defs.to_jsstring(this.value, from, to);
    }

}

const luaO_nilobject = new TValue(CT.LUA_TNIL, null);
module.exports.luaO_nilobject = luaO_nilobject;

class LClosure {

    constructor(L, n) {
        this.id = L.l_G.id_counter++;

        this.p = null;
        this.nupvalues = n;
        this.upvals = Array(n);
    }

}

class CClosure {

    constructor(L, f, n) {
        this.id = L.l_G.id_counter++;

        this.f = f;
        this.nupvalues = n;
        this.upvalue = new Array(n);
    }

}

/*
** Description of a local variable for function prototypes
** (used for debug information)
*/
class LocVar {
    constructor() {
        this.varname = null;
        this.startpc = NaN;  /* first point where variable is active */
        this.endpc = NaN;    /* first point where variable is dead */
    }
}

const RETS = defs.to_luastring("...", true);
const PRE  = defs.to_luastring("[string \"");
const POS  = defs.to_luastring("\"]");

const luaO_chunkid = function(source, bufflen) {
    source = source instanceof TValue ? source.value : source;
    bufflen = bufflen instanceof TValue ? bufflen.value : bufflen;
    let l = source.length;
    let out = [];
    if (source[0] === char['=']) {  /* 'literal' source */
        if (l < bufflen)  /* small enough? */
            out = source.slice(1);
        else {  /* truncate it */
            out = out.concat(source.slice(1, bufflen));
        }
    } else if (source[0] === char['@']) {  /* file name */
        if (l <= bufflen)  /* small enough? */
            out = source.slice(1);
        else {  /* add '...' before rest of name */
            bufflen -= RETS.length;
            out = RETS.concat(source.slice(1, l - bufflen));
        }
    } else {  /* string; format as [string "source"] */
        let nli = source.indexOf(char['\n']);  /* find first new line (if any) */
        let nl = nli > -1 ? source.slice(nli) : null;
        out = PRE;  /* add prefix */
        bufflen -= PRE.length + RETS.length + POS.length + 1;  /* save space for prefix+suffix+'\0' */
        if (l < bufflen && nl === null) {  /* small one-line source? */
            out = out.concat(source);  /* keep it */
        } else {
            if (nl !== null) l = nl.length - source.length;  /* stop at first newline */
            if (l > bufflen) l = bufflen;
            out = out.concat(source).concat(RETS);
        }
        out = out.concat(POS);
    }

    return out;
};

const luaO_hexavalue = function(c) {
    if (ljstype.lisdigit(c)) return c - char['0'];
    else return (String.fromCharCode(c).toLowerCase().charCodeAt(0) - char['a']) + 10;
};

const UTF8BUFFSZ = 8;

const luaO_utf8desc = function(buff, x) {
    let n = 1;  /* number of bytes put in buffer (backwards) */
    assert(x <= 0x10FFFF);
    if (x < 0x80)  /* ascii? */
        buff[UTF8BUFFSZ - 1] = x;
    else {  /* need continuation bytes */
        let mfb = 0x3f;  /* maximum that fits in first byte */
        do {
            buff[UTF8BUFFSZ - (n++)] = 0x80 | (x & 0x3f);
            x >>= 6;  /* remove added bits */
            mfb >>= 1;  /* now there is one less bit available in first byte */
        } while (x > mfb);  /* still needs continuation byte? */
        buff[UTF8BUFFSZ - n] = (~mfb << 1) | x;  /* add first byte */
    }
    return n;
};

/* maximum number of significant digits to read (to avoid overflows
   even with single floats) */
const MAXSIGDIG = 30;

/*
** convert an hexadecimal numeric string to a number, following
** C99 specification for 'strtod'
*/
const lua_strx2number = function(s) {
    let dot = char[luaconf.lua_getlocaledecpoint()];
    let r = 0.0;  /* result (accumulator) */
    let sigdig = 0;  /* number of significant digits */
    let nosigdig = 0;  /* number of non-significant digits */
    let e = 0;  /* exponent correction */
    let neg;  /* 1 if number is negative */
    let hasdot = false;  /* true after seen a dot */

    while (ljstype.lisspace(s[0])) s = s.slice(1);  /* skip initial spaces */

    neg = s[0] === char['-'];  /* check signal */
    s = neg || s[0] === char['+'] ? s.slice(1) : s;  /* skip sign if one */
    if (!(s[0] === char['0'] && (s[1] === char['x'] || s[1] === char['X'])))  /* check '0x' */
        return 0.0;  /* invalid format (no '0x') */

    for (s = s.slice(2); ; s = s.slice(1)) {  /* skip '0x' and read numeral */
        if (s[0] === dot) {
            if (hasdot) break;  /* second dot? stop loop */
            else hasdot = true;
        } else if (ljstype.lisxdigit(s[0])) {
            if (sigdig === 0 && s[0] === char['0'])  /* non-significant digit (zero)? */
                nosigdig++;
            else if (++sigdig <= MAXSIGDIG)  /* can read it without overflow? */
                r = (r * 16) + luaO_hexavalue(s[0]);
            else e++; /* too many digits; ignore, but still count for exponent */
            if (hasdot) e--;  /* decimal digit? correct exponent */
        } else break;  /* neither a dot nor a digit */
    }

    if (nosigdig + sigdig === 0)  /* no digits? */
        return 0.0;  /* invalid format */
    e *= 4;  /* each digit multiplies/divides value by 2^4 */
    if (s[0] === char['p'] || s[0] === char['P']) {  /* exponent part? */
        let exp1 = 0;  /* exponent value */
        let neg1;  /* exponent signal */
        s = s.slice(1);  /* skip 'p' */
        neg1 = s[0] === char['-'];  /* check signal */
        s = neg1 || s[0] === char['+'] ? s.slice(1) : s;  /* skip sign if one */
        if (!ljstype.lisdigit(s[0]))
            return 0.0;  /* invalid; must have at least one digit */
        while (ljstype.lisdigit(s[0])) {  /* read exponent */
            exp1 = exp1 * 10 + s[0] - char['0'];
            s = s.slice(1);
        }
        if (neg1) exp1 = -exp1;
        e += exp1;
    }
    if (neg) r = -r;
    return defs.to_jsstring(s).trim().search(/s/) < 0 ? luaconf.ldexp(r, e) : null;  /* Only valid if nothing left is s*/
};

const l_str2dloc = function(s, mode) {
    let flt = mode === 'x' ? lua_strx2number(s) : parseFloat(defs.to_jsstring(s));
    return !isNaN(flt) ? flt : null;  /* OK if no trailing characters */
};

const l_str2d = function(s) {
    let pidx = /[.xXnN]/g.exec(String.fromCharCode(...s));
    pidx = pidx ? pidx.index : null;
    let pmode = pidx ? s[pidx] : null;
    let mode = pmode ? String.fromCharCode(pmode).toLowerCase() : 0;
    if (mode === 'n')  /* reject 'inf' and 'nan' */
        return null;
    let end = l_str2dloc(s, mode);  /* try to convert */
    if (end === null) {   /* failed? may be a different locale */
        // throw new Error("Locale not available to handle number"); // TODO
    }
    return end;
};

const MAXBY10  = llimit.MAX_INT / 10;
const MAXLASTD = llimit.MAX_INT % 10;

const l_str2int = function(s) {
    let a = 0;
    let empty = true;
    let neg;

    while (ljstype.lisspace(s[0])) s = s.slice(1);  /* skip initial spaces */
    neg = s[0] === char['-'];

    if (neg || s[0] === char['+'])
        s = s.slice(1);

    if (s[0] === char['0'] && (s[1] === char['x'] || s[1] === char['X'])) {  /* hex? */
        s = s.slice(2);  /* skip '0x' */

        for (; ljstype.lisxdigit(s[0]); s = s.slice(1)) {
            a = a * 16 + luaO_hexavalue(s[0]);
            empty = false;
        }
    } else {  /* decimal */
        for (; ljstype.lisdigit(s[0]); s = s.slice(1)) {
            let d = s[0] - char['0'];
            if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg))  /* overflow? */
                return null;  /* do not accept it (as integer) */
            a = a * 10 + d;
            empty = false;
        }
    }

    while (ljstype.lisspace(s[0])) s = s.slice(1);  /* skip trailing spaces */

    if (empty || (s.length > 0 && s[0] !== 0)) return null;  /* something wrong in the numeral */
    else {
        return (neg ? -a : a)|0;
    }
};

const luaO_str2num = function(s) {
    let s2i = l_str2int(s);

    if (s2i !== null) {   /* try as an integer */
        return new TValue(CT.LUA_TNUMINT, s2i);
    } else {   /* else try as a float */
        s2i = l_str2d(s);

        if (s2i !== null) {
            return new TValue(CT.LUA_TNUMFLT, s2i);
        } else
            return false;  /* conversion failed */
    }
};

const luaO_utf8esc = function(x) {
    let buff = [];
    let n = 1;  /* number of bytes put in buffer (backwards) */
    assert(x <= 0x10ffff);
    if (x < 0x80)  /* ascii? */
        buff[UTF8BUFFSZ - 1] = x;
    else {  /* need continuation bytes */
        let mfb = 0x3f;  /* maximum that fits in first byte */
        do {  /* add continuation bytes */
            buff[UTF8BUFFSZ - (n++)] = 0x80 | (x & 0x3f);
            x >>= 6;  /* remove added bits */
            mfb >>= 1;  /* now there is one less bit available in first byte */
        } while (x > mfb);  /* still needs continuation byte? */
        buff[UTF8BUFFSZ - n] = (~mfb << 1) | x;  /* add first byte */
    }
    return {
        buff: buff,
        n: n
    };
};

/*
** converts an integer to a "floating point byte", represented as
** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
** eeeee !== 0 and (xxx) otherwise.
*/
const luaO_int2fb = function(x) {
    let e = 0;  /* exponent */
    if (x < 8) return x;
    while (x >= (8 << 4)) {  /* coarse steps */
        x = (x + 0xf) >> 4;  /* x = ceil(x / 16) */
        e += 4;
    }
    while (x >= (8 << 1)) {  /* fine steps */
        x = (x + 1) >> 1;  /* x = ceil(x / 2) */
        e++;
    }
    return ((e+1) << 3) | (x - 8);
};

const intarith = function(L, op, v1, v2) {
    switch (op) {
        case defs.LUA_OPADD:  return (v1 + v2)|0;
        case defs.LUA_OPSUB:  return (v1 - v2)|0;
        case defs.LUA_OPMUL:  return (v1 * v2)|0;
        case defs.LUA_OPMOD:  return (v1 - Math.floor(v1 / v2) * v2)|0; // % semantic on negative numbers is different in js
        case defs.LUA_OPIDIV: return (v1 / v2)|0;
        case defs.LUA_OPBAND: return (v1 & v2);
        case defs.LUA_OPBOR:  return (v1 | v2);
        case defs.LUA_OPBXOR: return (v1 ^ v2);
        case defs.LUA_OPSHL:  return (v1 << v2);
        case defs.LUA_OPSHR:  return (v1 >> v2);
        case defs.LUA_OPUNM:  return (0 - v1)|0;
        case defs.LUA_OPBNOT: return (~0 ^ v1);
    }
};


const numarith = function(L, op, v1, v2) {
    switch (op) {
        case defs.LUA_OPADD:  return v1 + v2;
        case defs.LUA_OPSUB:  return v1 - v2;
        case defs.LUA_OPMUL:  return v1 * v2;
        case defs.LUA_OPDIV:  return v1 / v2;
        case defs.LUA_OPPOW:  return Math.pow(v1, v2);
        case defs.LUA_OPIDIV: return (v1 / v2);
        case defs.LUA_OPUNM:  return -v1;
        case defs.LUA_OPMOD:  return v1 % v2;
    }
};

module.exports.CClosure       = CClosure;
module.exports.LClosure       = LClosure;
module.exports.LocVar         = LocVar;
module.exports.TValue         = TValue;
module.exports.UTF8BUFFSZ     = UTF8BUFFSZ;
module.exports.intarith       = intarith;
module.exports.luaO_chunkid   = luaO_chunkid;
module.exports.luaO_hexavalue = luaO_hexavalue;
module.exports.luaO_int2fb    = luaO_int2fb;
module.exports.luaO_str2num   = luaO_str2num;
module.exports.luaO_utf8desc  = luaO_utf8desc;
module.exports.luaO_utf8esc   = luaO_utf8esc;
module.exports.numarith       = numarith;