dlls/jscript/json.c

   1 /*
   2  * Copyright 2016 Jacek Caban for CodeWeavers
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  17  */
  18
  19 #include <math.h>
  20 #include <assert.h>
  21
  22 #include "jscript.h"
  23 #include "parser.h"
  24
  25 #include "wine/debug.h"
  26 #include "wine/unicode.h"
  27
  28 WINE_DEFAULT_DEBUG_CHANNEL(jscript);
  29
  30 static const WCHAR parseW[] = {'p','a','r','s','e',0};
  31 static const WCHAR stringifyW[] = {'s','t','r','i','n','g','i','f','y',0};
  32
  33 static const WCHAR nullW[] = {'n','u','l','l',0};
  34 static const WCHAR trueW[] = {'t','r','u','e',0};
  35 static const WCHAR falseW[] = {'f','a','l','s','e',0};
  36
  37 static const WCHAR toJSONW[] = {'t','o','J','S','O','N',0};
  38
  39 typedef struct {
  40     const WCHAR *ptr;
  41     const WCHAR *end;
  42     script_ctx_t *ctx;
  43 } json_parse_ctx_t;
  44
  45 static BOOL is_json_space(WCHAR c)
  46 {
  47     return c == ' ' || c == '\t' || c == '\n' || c == '\r';
  48 }
  49
  50 static WCHAR skip_spaces(json_parse_ctx_t *ctx)
  51 {
  52     while(is_json_space(*ctx->ptr))
  53         ctx->ptr++;
  54     return *ctx->ptr;
  55 }
  56
  57 static BOOL is_keyword(json_parse_ctx_t *ctx, const WCHAR *keyword)
  58 {
  59     unsigned i;
  60     for(i=0; keyword[i]; i++) {
  61         if(!ctx->ptr[i] || keyword[i] != ctx->ptr[i])
  62             return FALSE;
  63     }
  64     if(is_identifier_char(ctx->ptr[i]))
  65         return FALSE;
  66     ctx->ptr += i;
  67     return TRUE;
  68 }
  69
  70 /* ECMA-262 5.1 Edition    15.12.1.1 */
  71 static HRESULT parse_json_string(json_parse_ctx_t *ctx, WCHAR **r)
  72 {
  73     const WCHAR *ptr = ++ctx->ptr;
  74     size_t len;
  75     WCHAR *buf;
  76
  77     while(*ctx->ptr && *ctx->ptr != '"') {
  78         if(*ctx->ptr++ == '\\')
  79             ctx->ptr++;
  80     }
  81     if(!*ctx->ptr) {
  82         FIXME("unterminated string\n");
  83         return E_FAIL;
  84     }
  85
  86     len = ctx->ptr-ptr;
  87     buf = heap_alloc((len+1)*sizeof(WCHAR));
  88     if(!buf)
  89         return E_OUTOFMEMORY;
  90     if(len)
  91         memcpy(buf, ptr, len*sizeof(WCHAR));
  92     buf[len] = 0;
  93
  94     if(!unescape(buf)) {
  95         FIXME("unescape failed\n");
  96         heap_free(buf);
  97         return E_FAIL;
  98     }
  99
 100     ctx->ptr++;
 101     *r = buf;
 102     return S_OK;
 103 }
 104
 105 /* ECMA-262 5.1 Edition    15.12.1.2 */
 106 static HRESULT parse_json_value(json_parse_ctx_t *ctx, jsval_t *r)
 107 {
 108     HRESULT hres;
 109
 110     switch(skip_spaces(ctx)) {
 111
 112     /* JSONNullLiteral */
 113     case 'n':
 114         if(!is_keyword(ctx, nullW))
 115             break;
 116         *r = jsval_null();
 117         return S_OK;
 118
 119     /* JSONBooleanLiteral */
 120     case 't':
 121         if(!is_keyword(ctx, trueW))
 122             break;
 123         *r = jsval_bool(TRUE);
 124         return S_OK;
 125     case 'f':
 126         if(!is_keyword(ctx, falseW))
 127             break;
 128         *r = jsval_bool(FALSE);
 129         return S_OK;
 130
 131     /* JSONObject */
 132     case '{': {
 133         WCHAR *prop_name;
 134         jsdisp_t *obj;
 135         jsval_t val;
 136
 137         hres = create_object(ctx->ctx, NULL, &obj);
 138         if(FAILED(hres))
 139             return hres;
 140
 141         ctx->ptr++;
 142         if(skip_spaces(ctx) == '}') {
 143             ctx->ptr++;
 144             *r = jsval_obj(obj);
 145             return S_OK;
 146         }
 147
 148         while(1) {
 149             if(*ctx->ptr != '"')
 150                 break;
 151             hres = parse_json_string(ctx, &prop_name);
 152             if(FAILED(hres))
 153                 break;
 154
 155             if(skip_spaces(ctx) != ':') {
 156                 FIXME("missing ':'\n");
 157                 heap_free(prop_name);
 158                 break;
 159             }
 160
 161             ctx->ptr++;
 162             hres = parse_json_value(ctx, &val);
 163             if(SUCCEEDED(hres)) {
 164                 hres = jsdisp_propput_name(obj, prop_name, val);
 165                 jsval_release(val);
 166             }
 167             heap_free(prop_name);
 168             if(FAILED(hres))
 169                 break;
 170
 171             if(skip_spaces(ctx) == '}') {
 172                 ctx->ptr++;
 173                 *r = jsval_obj(obj);
 174                 return S_OK;
 175             }
 176
 177             if(*ctx->ptr++ != ',') {
 178                 FIXME("expected ','\n");
 179                 break;
 180             }
 181             skip_spaces(ctx);
 182         }
 183
 184         jsdisp_release(obj);
 185         break;
 186     }
 187
 188     /* JSONString */
 189     case '"': {
 190         WCHAR *string;
 191         jsstr_t *str;
 192
 193         hres = parse_json_string(ctx, &string);
 194         if(FAILED(hres))
 195             return hres;
 196
 197         /* FIXME: avoid reallocation */
 198         str = jsstr_alloc(string);
 199         heap_free(string);
 200         if(!str)
 201             return E_OUTOFMEMORY;
 202
 203         *r = jsval_string(str);
 204         return S_OK;
 205     }
 206
 207     /* JSONArray */
 208     case '[': {
 209         jsdisp_t *array;
 210         unsigned i = 0;
 211         jsval_t val;
 212
 213         hres = create_array(ctx->ctx, 0, &array);
 214         if(FAILED(hres))
 215             return hres;
 216
 217         ctx->ptr++;
 218         if(skip_spaces(ctx) == ']') {
 219             ctx->ptr++;
 220             *r = jsval_obj(array);
 221             return S_OK;
 222         }
 223
 224         while(1) {
 225             hres = parse_json_value(ctx, &val);
 226             if(FAILED(hres))
 227                 break;
 228
 229             hres = jsdisp_propput_idx(array, i, val);
 230             jsval_release(val);
 231             if(FAILED(hres))
 232                 break;
 233
 234             if(skip_spaces(ctx) == ']') {
 235                 ctx->ptr++;
 236                 *r = jsval_obj(array);
 237                 return S_OK;
 238             }
 239
 240             if(*ctx->ptr != ',') {
 241                 FIXME("expected ','\n");
 242                 break;
 243             }
 244
 245             ctx->ptr++;
 246             i++;
 247         }
 248
 249         jsdisp_release(array);
 250         break;
 251     }
 252
 253     /* JSONNumber */
 254     default: {
 255         int sign = 1;
 256         double n;
 257
 258         if(*ctx->ptr == '-') {
 259             sign = -1;
 260             ctx->ptr++;
 261             skip_spaces(ctx);
 262         }
 263
 264         if(!isdigitW(*ctx->ptr))
 265             break;
 266
 267         if(*ctx->ptr == '0') {
 268             ctx->ptr++;
 269             n = 0;
 270             if(is_identifier_char(*ctx->ptr))
 271                 break;
 272         }else {
 273             hres = parse_decimal(&ctx->ptr, ctx->end, &n);
 274             if(FAILED(hres))
 275                 return hres;
 276         }
 277
 278         *r = jsval_number(sign*n);
 279         return S_OK;
 280     }
 281     }
 282
 283     FIXME("Syntax error at %s\n", debugstr_w(ctx->ptr));
 284     return E_FAIL;
 285 }
 286
 287 /* ECMA-262 5.1 Edition    15.12.2 */
 288 static HRESULT JSON_parse(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, jsval_t *argv, jsval_t *r)
 289 {
 290     json_parse_ctx_t parse_ctx;
 291     const WCHAR *buf;
 292     jsstr_t *str;
 293     jsval_t ret;
 294     HRESULT hres;
 295
 296     if(argc != 1) {
 297         FIXME("Unsupported args\n");
 298         return E_INVALIDARG;
 299     }
 300
 301     hres = to_flat_string(ctx, argv[0], &str, &buf);
 302     if(FAILED(hres))
 303         return hres;
 304
 305     TRACE("%s\n", debugstr_w(buf));
 306
 307     parse_ctx.ptr = buf;
 308     parse_ctx.end = buf + jsstr_length(str);
 309     parse_ctx.ctx = ctx;
 310     hres = parse_json_value(&parse_ctx, &ret);
 311     jsstr_release(str);
 312     if(FAILED(hres))
 313         return hres;
 314
 315     if(skip_spaces(&parse_ctx)) {
 316         FIXME("syntax error\n");
 317         jsval_release(ret);
 318         return E_FAIL;
 319     }
 320
 321     if(r)
 322         *r = ret;
 323     else
 324         jsval_release(ret);
 325     return S_OK;
 326 }
 327
 328 typedef struct {
 329     script_ctx_t *ctx;
 330
 331     WCHAR *buf;
 332     size_t buf_size;
 333     size_t buf_len;
 334
 335     jsdisp_t **stack;
 336     size_t stack_top;
 337     size_t stack_size;
 338
 339     WCHAR gap[11]; /* according to the spec, it's no longer than 10 chars */
 340 } stringify_ctx_t;
 341
 342 static BOOL stringify_push_obj(stringify_ctx_t *ctx, jsdisp_t *obj)
 343 {
 344     if(!ctx->stack_size) {
 345         ctx->stack = heap_alloc(4*sizeof(*ctx->stack));
 346         if(!ctx->stack)
 347             return FALSE;
 348         ctx->stack_size = 4;
 349     }else if(ctx->stack_top == ctx->stack_size) {
 350         jsdisp_t **new_stack;
 351
 352         new_stack = heap_realloc(ctx->stack, ctx->stack_size*2*sizeof(*ctx->stack));
 353         if(!new_stack)
 354             return FALSE;
 355         ctx->stack = new_stack;
 356         ctx->stack_size *= 2;
 357     }
 358
 359     ctx->stack[ctx->stack_top++] = obj;
 360     return TRUE;
 361 }
 362
 363 static void stringify_pop_obj(stringify_ctx_t *ctx)
 364 {
 365     ctx->stack_top--;
 366 }
 367
 368 static BOOL is_on_stack(stringify_ctx_t *ctx, jsdisp_t *obj)
 369 {
 370     size_t i = ctx->stack_top;
 371     while(i--) {
 372         if(ctx->stack[i] == obj)
 373             return TRUE;
 374     }
 375     return FALSE;
 376 }
 377
 378 static BOOL append_string_len(stringify_ctx_t *ctx, const WCHAR *str, size_t len)
 379 {
 380     if(!ctx->buf_size) {
 381         ctx->buf = heap_alloc(len*2*sizeof(WCHAR));
 382         if(!ctx->buf)
 383             return FALSE;
 384         ctx->buf_size = len*2;
 385     }else if(ctx->buf_len + len > ctx->buf_size) {
 386         WCHAR *new_buf;
 387         size_t new_size;
 388
 389         new_size = ctx->buf_size * 2 + len;
 390         new_buf = heap_realloc(ctx->buf, new_size*sizeof(WCHAR));
 391         if(!new_buf)
 392             return FALSE;
 393         ctx->buf = new_buf;
 394         ctx->buf_size = new_size;
 395     }
 396
 397     if(len)
 398         memcpy(ctx->buf + ctx->buf_len, str, len*sizeof(WCHAR));
 399     ctx->buf_len += len;
 400     return TRUE;
 401 }
 402
 403 static inline BOOL append_string(stringify_ctx_t *ctx, const WCHAR *str)
 404 {
 405     return append_string_len(ctx, str, strlenW(str));
 406 }
 407
 408 static inline BOOL append_char(stringify_ctx_t *ctx, WCHAR c)
 409 {
 410     return append_string_len(ctx, &c, 1);
 411 }
 412
 413 static inline BOOL append_simple_quote(stringify_ctx_t *ctx, WCHAR c)
 414 {
 415     WCHAR str[] = {'\\',c};
 416     return append_string_len(ctx, str, 2);
 417 }
 418
 419 static HRESULT maybe_to_primitive(script_ctx_t *ctx, jsval_t val, jsval_t *r)
 420 {
 421     jsdisp_t *obj;
 422     HRESULT hres;
 423
 424     if(!is_object_instance(val) || !get_object(val) || !(obj = iface_to_jsdisp(get_object(val))))
 425         return jsval_copy(val, r);
 426
 427     if(is_class(obj, JSCLASS_NUMBER)) {
 428         double n;
 429         hres = to_number(ctx, val, &n);
 430         jsdisp_release(obj);
 431         if(SUCCEEDED(hres))
 432             *r = jsval_number(n);
 433         return hres;
 434     }
 435
 436     if(is_class(obj, JSCLASS_STRING)) {
 437         jsstr_t *str;
 438         hres = to_string(ctx, val, &str);
 439         jsdisp_release(obj);
 440         if(SUCCEEDED(hres))
 441             *r = jsval_string(str);
 442         return hres;
 443     }
 444
 445     if(is_class(obj, JSCLASS_BOOLEAN)) {
 446         *r = jsval_bool(bool_obj_value(obj));
 447         jsdisp_release(obj);
 448         return S_OK;
 449     }
 450
 451     *r = jsval_obj(obj);
 452     return S_OK;
 453 }
 454
 455 /* ECMA-262 5.1 Edition    15.12.3 (abstract operation Quote) */
 456 static HRESULT json_quote(stringify_ctx_t *ctx, const WCHAR *ptr, size_t len)
 457 {
 458     if(!ptr || !append_char(ctx, '"'))
 459         return E_OUTOFMEMORY;
 460
 461     while(len--) {
 462         switch(*ptr) {
 463         case '"':
 464         case '\\':
 465             if(!append_simple_quote(ctx, *ptr))
 466                 return E_OUTOFMEMORY;
 467             break;
 468         case '\b':
 469             if(!append_simple_quote(ctx, 'b'))
 470                 return E_OUTOFMEMORY;
 471             break;
 472         case '\f':
 473             if(!append_simple_quote(ctx, 'f'))
 474                 return E_OUTOFMEMORY;
 475             break;
 476         case '\n':
 477             if(!append_simple_quote(ctx, 'n'))
 478                 return E_OUTOFMEMORY;
 479             break;
 480         case '\r':
 481             if(!append_simple_quote(ctx, 'r'))
 482                 return E_OUTOFMEMORY;
 483             break;
 484         case '\t':
 485             if(!append_simple_quote(ctx, 't'))
 486                 return E_OUTOFMEMORY;
 487             break;
 488         default:
 489             if(*ptr < ' ') {
 490                 const WCHAR formatW[] = {'\\','u','%','0','4','x',0};
 491                 WCHAR buf[7];
 492                 sprintfW(buf, formatW, *ptr);
 493                 if(!append_string(ctx, buf))
 494                     return E_OUTOFMEMORY;
 495             }else {
 496                 if(!append_char(ctx, *ptr))
 497                     return E_OUTOFMEMORY;
 498             }
 499         }
 500         ptr++;
 501     }
 502
 503     return append_char(ctx, '"') ? S_OK : E_OUTOFMEMORY;
 504 }
 505
 506 static inline BOOL is_callable(jsdisp_t *obj)
 507 {
 508     return is_class(obj, JSCLASS_FUNCTION);
 509 }
 510
 511 static HRESULT stringify(stringify_ctx_t *ctx, jsval_t val);
 512
 513 /* ECMA-262 5.1 Edition    15.12.3 (abstract operation JA) */
 514 static HRESULT stringify_array(stringify_ctx_t *ctx, jsdisp_t *obj)
 515 {
 516     unsigned length, i, j;
 517     jsval_t val;
 518     HRESULT hres;
 519
 520     if(is_on_stack(ctx, obj)) {
 521         FIXME("Found a cycle\n");
 522         return E_FAIL;
 523     }
 524
 525     if(!stringify_push_obj(ctx, obj))
 526         return E_OUTOFMEMORY;
 527
 528     if(!append_char(ctx, '['))
 529         return E_OUTOFMEMORY;
 530
 531     length = array_get_length(obj);
 532
 533     for(i=0; i < length; i++) {
 534         if(i && !append_char(ctx, ','))
 535             return E_OUTOFMEMORY;
 536
 537         if(*ctx->gap) {
 538             if(!append_char(ctx, '\n'))
 539                 return E_OUTOFMEMORY;
 540
 541             for(j=0; j < ctx->stack_top; j++) {
 542                 if(!append_string(ctx, ctx->gap))
 543                     return E_OUTOFMEMORY;
 544             }
 545         }
 546
 547         hres = jsdisp_get_idx(obj, i, &val);
 548         if(SUCCEEDED(hres)) {
 549             hres = stringify(ctx, val);
 550             if(FAILED(hres))
 551                 return hres;
 552             if(hres == S_FALSE && !append_string(ctx, nullW))
 553                 return E_OUTOFMEMORY;
 554         }else if(hres == DISP_E_UNKNOWNNAME) {
 555             if(!append_string(ctx, nullW))
 556                 return E_OUTOFMEMORY;
 557         }else {
 558             return hres;
 559         }
 560     }
 561
 562     if((length && *ctx->gap && !append_char(ctx, '\n')) || !append_char(ctx, ']'))
 563         return E_OUTOFMEMORY;
 564
 565     stringify_pop_obj(ctx);
 566     return S_OK;
 567 }
 568
 569 /* ECMA-262 5.1 Edition    15.12.3 (abstract operation JO) */
 570 static HRESULT stringify_object(stringify_ctx_t *ctx, jsdisp_t *obj)
 571 {
 572     DISPID dispid = DISPID_STARTENUM;
 573     jsval_t val = jsval_undefined();
 574     unsigned prop_cnt = 0, i;
 575     size_t stepback;
 576     BSTR prop_name;
 577     HRESULT hres;
 578
 579     if(is_on_stack(ctx, obj)) {
 580         FIXME("Found a cycle\n");
 581         return E_FAIL;
 582     }
 583
 584     if(!stringify_push_obj(ctx, obj))
 585         return E_OUTOFMEMORY;
 586
 587     if(!append_char(ctx, '{'))
 588         return E_OUTOFMEMORY;
 589
 590     while((hres = IDispatchEx_GetNextDispID(&obj->IDispatchEx_iface, fdexEnumDefault, dispid, &dispid)) == S_OK) {
 591         jsval_release(val);
 592         hres = jsdisp_propget(obj, dispid, &val);
 593         if(FAILED(hres))
 594             return hres;
 595
 596         if(is_undefined(val))
 597             continue;
 598
 599         stepback = ctx->buf_len;
 600
 601         if(prop_cnt && !append_char(ctx, ',')) {
 602             hres = E_OUTOFMEMORY;
 603             break;
 604         }
 605
 606         if(*ctx->gap) {
 607             if(!append_char(ctx, '\n')) {
 608                 hres = E_OUTOFMEMORY;
 609                 break;
 610             }
 611
 612             for(i=0; i < ctx->stack_top; i++) {
 613                 if(!append_string(ctx, ctx->gap)) {
 614                     hres = E_OUTOFMEMORY;
 615                     break;
 616                 }
 617             }
 618         }
 619
 620         hres = IDispatchEx_GetMemberName(&obj->IDispatchEx_iface, dispid, &prop_name);
 621         if(FAILED(hres))
 622             break;
 623
 624         hres = json_quote(ctx, prop_name, SysStringLen(prop_name));
 625         SysFreeString(prop_name);
 626         if(FAILED(hres))
 627             break;
 628
 629         if(!append_char(ctx, ':') || (*ctx->gap && !append_char(ctx, ' '))) {
 630             hres = E_OUTOFMEMORY;
 631             break;
 632         }
 633
 634         hres = stringify(ctx, val);
 635         if(FAILED(hres))
 636             break;
 637
 638         if(hres == S_FALSE) {
 639             ctx->buf_len = stepback;
 640             continue;
 641         }
 642
 643         prop_cnt++;
 644     }
 645     jsval_release(val);
 646     if(FAILED(hres))
 647         return hres;
 648
 649     if(prop_cnt && *ctx->gap) {
 650         if(!append_char(ctx, '\n'))
 651             return E_OUTOFMEMORY;
 652
 653         for(i=1; i < ctx->stack_top; i++) {
 654             if(!append_string(ctx, ctx->gap)) {
 655                 hres = E_OUTOFMEMORY;
 656                 break;
 657             }
 658         }
 659     }
 660
 661     if(!append_char(ctx, '}'))
 662         return E_OUTOFMEMORY;
 663
 664     stringify_pop_obj(ctx);
 665     return S_OK;
 666 }
 667
 668 /* ECMA-262 5.1 Edition    15.12.3 (abstract operation Str) */
 669 static HRESULT stringify(stringify_ctx_t *ctx, jsval_t val)
 670 {
 671     jsval_t value;
 672     HRESULT hres;
 673
 674     if(is_object_instance(val) && get_object(val)) {
 675         jsdisp_t *obj;
 676         DISPID id;
 677
 678         obj = iface_to_jsdisp(get_object(val));
 679         if(!obj)
 680             return S_FALSE;
 681
 682         hres = jsdisp_get_id(obj, toJSONW, 0, &id);
 683         jsdisp_release(obj);
 684         if(hres == S_OK)
 685             FIXME("Use toJSON.\n");
 686     }
 687
 688     /* FIXME: Support replacer replacer. */
 689
 690     hres = maybe_to_primitive(ctx->ctx, val, &value);
 691     if(FAILED(hres))
 692         return hres;
 693
 694     switch(jsval_type(value)) {
 695     case JSV_NULL:
 696         if(!append_string(ctx, nullW))
 697             hres = E_OUTOFMEMORY;
 698         break;
 699     case JSV_BOOL:
 700         if(!append_string(ctx, get_bool(value) ? trueW : falseW))
 701             hres = E_OUTOFMEMORY;
 702         break;
 703     case JSV_STRING: {
 704         jsstr_t *str = get_string(value);
 705         const WCHAR *ptr = jsstr_flatten(str);
 706         if(ptr)
 707             hres = json_quote(ctx, ptr, jsstr_length(str));
 708         else
 709             hres = E_OUTOFMEMORY;
 710         break;
 711     }
 712     case JSV_NUMBER: {
 713         double n = get_number(value);
 714         if(is_finite(n)) {
 715             const WCHAR *ptr;
 716             jsstr_t *str;
 717
 718             /* FIXME: Optimize. There is no need for jsstr_t here. */
 719             hres = double_to_string(n, &str);
 720             if(FAILED(hres))
 721                 break;
 722
 723             ptr = jsstr_flatten(str);
 724             assert(ptr != NULL);
 725             hres = ptr && !append_string_len(ctx, ptr, jsstr_length(str)) ? E_OUTOFMEMORY : S_OK;
 726             jsstr_release(str);
 727         }else {
 728             if(!append_string(ctx, nullW))
 729                 hres = E_OUTOFMEMORY;
 730         }
 731         break;
 732     }
 733     case JSV_OBJECT: {
 734         jsdisp_t *obj;
 735
 736         obj = iface_to_jsdisp(get_object(value));
 737         if(!obj) {
 738             hres = S_FALSE;
 739             break;
 740         }
 741
 742         if(!is_callable(obj))
 743             hres = is_class(obj, JSCLASS_ARRAY) ? stringify_array(ctx, obj) : stringify_object(ctx, obj);
 744         else
 745             hres = S_FALSE;
 746
 747         jsdisp_release(obj);
 748         break;
 749     }
 750     case JSV_UNDEFINED:
 751         hres = S_FALSE;
 752         break;
 753     case JSV_VARIANT:
 754         FIXME("VARIANT\n");
 755         hres = E_NOTIMPL;
 756         break;
 757     }
 758
 759     jsval_release(value);
 760     return hres;
 761 }
 762
 763 /* ECMA-262 5.1 Edition    15.12.3 */
 764 static HRESULT JSON_stringify(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, unsigned argc, jsval_t *argv, jsval_t *r)
 765 {
 766     stringify_ctx_t stringify_ctx = {ctx, NULL,0,0, NULL,0,0, {0}};
 767     HRESULT hres;
 768
 769     TRACE("\n");
 770
 771     if(!argc) {
 772         if(r)
 773             *r = jsval_undefined();
 774         return S_OK;
 775     }
 776
 777     if(argc >= 2 && is_object_instance(argv[1])) {
 778         FIXME("Replacer %s not yet supported\n", debugstr_jsval(argv[1]));
 779         return E_NOTIMPL;
 780     }
 781
 782     if(argc >= 3) {
 783         jsval_t space_val;
 784
 785         hres = maybe_to_primitive(ctx, argv[2], &space_val);
 786         if(FAILED(hres))
 787             return hres;
 788
 789         if(is_number(space_val)) {
 790             double n = get_number(space_val);
 791             if(n >= 1) {
 792                 int i, len;
 793                 if(n > 10)
 794                     n = 10;
 795                 len = floor(n);
 796                 for(i=0; i < len; i++)
 797                     stringify_ctx.gap[i] = ' ';
 798                 stringify_ctx.gap[len] = 0;
 799             }
 800         }else if(is_string(space_val)) {
 801             jsstr_t *space_str = get_string(space_val);
 802             size_t len = jsstr_length(space_str);
 803             if(len > 10)
 804                 len = 10;
 805             jsstr_extract(space_str, 0, len, stringify_ctx.gap);
 806         }
 807
 808         jsval_release(space_val);
 809     }
 810
 811     hres = stringify(&stringify_ctx, argv[0]);
 812     if(SUCCEEDED(hres) && r) {
 813         assert(!stringify_ctx.stack_top);
 814
 815         if(hres == S_OK) {
 816             jsstr_t *ret = jsstr_alloc_len(stringify_ctx.buf, stringify_ctx.buf_len);
 817             if(ret)
 818                 *r = jsval_string(ret);
 819             else
 820                 hres = E_OUTOFMEMORY;
 821         }else {
 822             *r = jsval_undefined();
 823         }
 824     }
 825
 826     heap_free(stringify_ctx.buf);
 827     heap_free(stringify_ctx.stack);
 828     return hres;
 829 }
 830
 831 static const builtin_prop_t JSON_props[] = {
 832     {parseW,     JSON_parse,     PROPF_METHOD|2},
 833     {stringifyW, JSON_stringify, PROPF_METHOD|3}
 834 };
 835
 836 static const builtin_info_t JSON_info = {
 837     JSCLASS_JSON,
 838     {NULL, NULL, 0},
 839     ARRAY_SIZE(JSON_props),
 840     JSON_props,
 841     NULL,
 842     NULL
 843 };
 844
 845 HRESULT create_json(script_ctx_t *ctx, jsdisp_t **ret)
 846 {
 847     jsdisp_t *json;
 848     HRESULT hres;
 849
 850     json = heap_alloc_zero(sizeof(*json));
 851     if(!json)
 852         return E_OUTOFMEMORY;
 853
 854     hres = init_dispex_from_constr(json, ctx, &JSON_info, ctx->object_constr);
 855     if(FAILED(hres)) {
 856         heap_free(json);
 857         return hres;
 858     }
 859
 860     *ret = json;
 861     return S_OK;
 862 }