xref: /vim-8.2.3635/src/json.c (revision 8ee2d36e)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * json.c: Encoding and decoding JSON.
12  *
13  * Follows this standard: https://tools.ietf.org/html/rfc7159.html
14  */
15 #define USING_FLOAT_STUFF
16 
17 #include "vim.h"
18 
19 #if defined(FEAT_EVAL) || defined(PROTO)
20 
21 static int json_encode_item(garray_T *gap, typval_T *val, int copyID, int options);
22 static int json_decode_item(js_read_T *reader, typval_T *res, int options);
23 
24 /*
25  * Encode "val" into a JSON format string.
26  * The result is added to "gap"
27  * Returns FAIL on failure and makes gap->ga_data empty.
28  */
29     static int
30 json_encode_gap(garray_T *gap, typval_T *val, int options)
31 {
32     if (json_encode_item(gap, val, get_copyID(), options) == FAIL)
33     {
34 	ga_clear(gap);
35 	gap->ga_data = vim_strsave((char_u *)"");
36 	return FAIL;
37     }
38     return OK;
39 }
40 
41 /*
42  * Encode "val" into a JSON format string.
43  * The result is in allocated memory.
44  * The result is empty when encoding fails.
45  * "options" can contain JSON_JS, JSON_NO_NONE and JSON_NL.
46  */
47     char_u *
48 json_encode(typval_T *val, int options)
49 {
50     garray_T ga;
51 
52     /* Store bytes in the growarray. */
53     ga_init2(&ga, 1, 4000);
54     json_encode_gap(&ga, val, options);
55     return ga.ga_data;
56 }
57 
58 /*
59  * Encode ["nr", "val"] into a JSON format string in allocated memory.
60  * "options" can contain JSON_JS, JSON_NO_NONE and JSON_NL.
61  * Returns NULL when out of memory.
62  */
63     char_u *
64 json_encode_nr_expr(int nr, typval_T *val, int options)
65 {
66     typval_T	listtv;
67     typval_T	nrtv;
68     garray_T	ga;
69 
70     nrtv.v_type = VAR_NUMBER;
71     nrtv.vval.v_number = nr;
72     if (rettv_list_alloc(&listtv) == FAIL)
73 	return NULL;
74     if (list_append_tv(listtv.vval.v_list, &nrtv) == FAIL
75 	    || list_append_tv(listtv.vval.v_list, val) == FAIL)
76     {
77 	list_unref(listtv.vval.v_list);
78 	return NULL;
79     }
80 
81     ga_init2(&ga, 1, 4000);
82     if (json_encode_gap(&ga, &listtv, options) == OK && (options & JSON_NL))
83 	ga_append(&ga, '\n');
84     list_unref(listtv.vval.v_list);
85     return ga.ga_data;
86 }
87 
88     static void
89 write_string(garray_T *gap, char_u *str)
90 {
91     char_u	*res = str;
92     char_u	numbuf[NUMBUFLEN];
93 
94     if (res == NULL)
95 	ga_concat(gap, (char_u *)"\"\"");
96     else
97     {
98 #if defined(FEAT_MBYTE) && defined(USE_ICONV)
99 	vimconv_T   conv;
100 	char_u	    *converted = NULL;
101 
102 	if (!enc_utf8)
103 	{
104 	    /* Convert the text from 'encoding' to utf-8, the JSON string is
105 	     * always utf-8. */
106 	    conv.vc_type = CONV_NONE;
107 	    convert_setup(&conv, p_enc, (char_u*)"utf-8");
108 	    if (conv.vc_type != CONV_NONE)
109 		converted = res = string_convert(&conv, res, NULL);
110 	    convert_setup(&conv, NULL, NULL);
111 	}
112 #endif
113 	ga_append(gap, '"');
114 	while (*res != NUL)
115 	{
116 	    int c;
117 #ifdef FEAT_MBYTE
118 	    /* always use utf-8 encoding, ignore 'encoding' */
119 	    c = utf_ptr2char(res);
120 #else
121 	    c = *res;
122 #endif
123 
124 	    switch (c)
125 	    {
126 		case 0x08:
127 		    ga_append(gap, '\\'); ga_append(gap, 'b'); break;
128 		case 0x09:
129 		    ga_append(gap, '\\'); ga_append(gap, 't'); break;
130 		case 0x0a:
131 		    ga_append(gap, '\\'); ga_append(gap, 'n'); break;
132 		case 0x0c:
133 		    ga_append(gap, '\\'); ga_append(gap, 'f'); break;
134 		case 0x0d:
135 		    ga_append(gap, '\\'); ga_append(gap, 'r'); break;
136 		case 0x22: /* " */
137 		case 0x5c: /* \ */
138 		    ga_append(gap, '\\');
139 		    ga_append(gap, c);
140 		    break;
141 		default:
142 		    if (c >= 0x20)
143 		    {
144 #ifdef FEAT_MBYTE
145 			numbuf[utf_char2bytes(c, numbuf)] = NUL;
146 #else
147 			numbuf[0] = c;
148 			numbuf[1] = NUL;
149 #endif
150 			ga_concat(gap, numbuf);
151 		    }
152 		    else
153 		    {
154 			vim_snprintf((char *)numbuf, NUMBUFLEN,
155 							 "\\u%04lx", (long)c);
156 			ga_concat(gap, numbuf);
157 		    }
158 	    }
159 #ifdef FEAT_MBYTE
160 	    res += utf_ptr2len(res);
161 #else
162 	    ++res;
163 #endif
164 	}
165 	ga_append(gap, '"');
166 #if defined(FEAT_MBYTE) && defined(USE_ICONV)
167 	vim_free(converted);
168 #endif
169     }
170 }
171 
172 /*
173  * Return TRUE if "key" can be used without quotes.
174  * That is when it starts with a letter and only contains letters, digits and
175  * underscore.
176  */
177     static int
178 is_simple_key(char_u *key)
179 {
180     char_u *p;
181 
182     if (!ASCII_ISALPHA(*key))
183 	return FALSE;
184     for (p = key + 1; *p != NUL; ++p)
185 	if (!ASCII_ISALPHA(*p) && *p != '_' && !vim_isdigit(*p))
186 	    return FALSE;
187     return TRUE;
188 }
189 
190 /*
191  * Encode "val" into "gap".
192  * Return FAIL or OK.
193  */
194     static int
195 json_encode_item(garray_T *gap, typval_T *val, int copyID, int options)
196 {
197     char_u	numbuf[NUMBUFLEN];
198     char_u	*res;
199     list_T	*l;
200     dict_T	*d;
201 
202     switch (val->v_type)
203     {
204 	case VAR_SPECIAL:
205 	    switch (val->vval.v_number)
206 	    {
207 		case VVAL_FALSE: ga_concat(gap, (char_u *)"false"); break;
208 		case VVAL_TRUE: ga_concat(gap, (char_u *)"true"); break;
209 		case VVAL_NONE: if ((options & JSON_JS) != 0
210 					     && (options & JSON_NO_NONE) == 0)
211 				    /* empty item */
212 				    break;
213 				/* FALLTHROUGH */
214 		case VVAL_NULL: ga_concat(gap, (char_u *)"null"); break;
215 	    }
216 	    break;
217 
218 	case VAR_NUMBER:
219 	    vim_snprintf((char *)numbuf, NUMBUFLEN, "%lld",
220 						    val->vval.v_number);
221 	    ga_concat(gap, numbuf);
222 	    break;
223 
224 	case VAR_STRING:
225 	    res = val->vval.v_string;
226 	    write_string(gap, res);
227 	    break;
228 
229 	case VAR_FUNC:
230 	case VAR_PARTIAL:
231 	case VAR_JOB:
232 	case VAR_CHANNEL:
233 	    /* no JSON equivalent TODO: better error */
234 	    EMSG(_(e_invarg));
235 	    return FAIL;
236 
237 	case VAR_LIST:
238 	    l = val->vval.v_list;
239 	    if (l == NULL)
240 		ga_concat(gap, (char_u *)"[]");
241 	    else
242 	    {
243 		if (l->lv_copyID == copyID)
244 		    ga_concat(gap, (char_u *)"[]");
245 		else
246 		{
247 		    listitem_T	*li;
248 
249 		    l->lv_copyID = copyID;
250 		    ga_append(gap, '[');
251 		    for (li = l->lv_first; li != NULL && !got_int; )
252 		    {
253 			if (json_encode_item(gap, &li->li_tv, copyID,
254 						   options & JSON_JS) == FAIL)
255 			    return FAIL;
256 			if ((options & JSON_JS)
257 				&& li->li_next == NULL
258 				&& li->li_tv.v_type == VAR_SPECIAL
259 				&& li->li_tv.vval.v_number == VVAL_NONE)
260 			    /* add an extra comma if the last item is v:none */
261 			    ga_append(gap, ',');
262 			li = li->li_next;
263 			if (li != NULL)
264 			    ga_append(gap, ',');
265 		    }
266 		    ga_append(gap, ']');
267 		    l->lv_copyID = 0;
268 		}
269 	    }
270 	    break;
271 
272 	case VAR_DICT:
273 	    d = val->vval.v_dict;
274 	    if (d == NULL)
275 		ga_concat(gap, (char_u *)"{}");
276 	    else
277 	    {
278 		if (d->dv_copyID == copyID)
279 		    ga_concat(gap, (char_u *)"{}");
280 		else
281 		{
282 		    int		first = TRUE;
283 		    int		todo = (int)d->dv_hashtab.ht_used;
284 		    hashitem_T	*hi;
285 
286 		    d->dv_copyID = copyID;
287 		    ga_append(gap, '{');
288 
289 		    for (hi = d->dv_hashtab.ht_array; todo > 0 && !got_int;
290 									 ++hi)
291 			if (!HASHITEM_EMPTY(hi))
292 			{
293 			    --todo;
294 			    if (first)
295 				first = FALSE;
296 			    else
297 				ga_append(gap, ',');
298 			    if ((options & JSON_JS)
299 						 && is_simple_key(hi->hi_key))
300 				ga_concat(gap, hi->hi_key);
301 			    else
302 				write_string(gap, hi->hi_key);
303 			    ga_append(gap, ':');
304 			    if (json_encode_item(gap, &dict_lookup(hi)->di_tv,
305 				      copyID, options | JSON_NO_NONE) == FAIL)
306 				return FAIL;
307 			}
308 		    ga_append(gap, '}');
309 		    d->dv_copyID = 0;
310 		}
311 	    }
312 	    break;
313 
314 	case VAR_FLOAT:
315 #ifdef FEAT_FLOAT
316 # if defined(HAVE_MATH_H)
317 	    if (isnan(val->vval.v_float))
318 		ga_concat(gap, (char_u *)"NaN");
319 	    else if (isinf(val->vval.v_float))
320 		ga_concat(gap, (char_u *)"Infinity");
321 	    else
322 # endif
323 	    {
324 		vim_snprintf((char *)numbuf, NUMBUFLEN, "%g",
325 							   val->vval.v_float);
326 		ga_concat(gap, numbuf);
327 	    }
328 	    break;
329 #endif
330 	case VAR_UNKNOWN:
331 	    internal_error("json_encode_item()");
332 	    return FAIL;
333     }
334     return OK;
335 }
336 
337 /*
338  * When "reader" has less than NUMBUFLEN bytes available, call the fill
339  * callback to get more.
340  */
341     static void
342 fill_numbuflen(js_read_T *reader)
343 {
344     if (reader->js_fill != NULL && (int)(reader->js_end - reader->js_buf)
345 						- reader->js_used < NUMBUFLEN)
346     {
347 	if (reader->js_fill(reader))
348 	    reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
349     }
350 }
351 
352 /*
353  * Skip white space in "reader".  All characters <= space are considered white
354  * space.
355  * Also tops up readahead when needed.
356  */
357     static void
358 json_skip_white(js_read_T *reader)
359 {
360     int c;
361 
362     for (;;)
363     {
364 	c = reader->js_buf[reader->js_used];
365 	if (reader->js_fill != NULL && c == NUL)
366 	{
367 	    if (reader->js_fill(reader))
368 	    {
369 		reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
370 		continue;
371 	    }
372 	}
373 	if (c == NUL || c > ' ')
374 	    break;
375 	++reader->js_used;
376     }
377     fill_numbuflen(reader);
378 }
379 
380     static int
381 json_decode_string(js_read_T *reader, typval_T *res, int quote)
382 {
383     garray_T    ga;
384     int		len;
385     char_u	*p;
386     int		c;
387     varnumber_T	nr;
388 
389     if (res != NULL)
390 	ga_init2(&ga, 1, 200);
391 
392     p = reader->js_buf + reader->js_used + 1; /* skip over " or ' */
393     while (*p != quote)
394     {
395 	/* The JSON is always expected to be utf-8, thus use utf functions
396 	 * here. The string is converted below if needed. */
397 	if (*p == NUL || p[1] == NUL
398 #ifdef FEAT_MBYTE
399 		|| utf_ptr2len(p) < utf_byte2len(*p)
400 #endif
401 		)
402 	{
403 	    /* Not enough bytes to make a character or end of the string. Get
404 	     * more if possible. */
405 	    if (reader->js_fill == NULL)
406 		break;
407 	    len = (int)(reader->js_end - p);
408 	    reader->js_used = (int)(p - reader->js_buf);
409 	    if (!reader->js_fill(reader))
410 		break; /* didn't get more */
411 	    p = reader->js_buf + reader->js_used;
412 	    reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
413 	    continue;
414 	}
415 
416 	if (*p == '\\')
417 	{
418 	    c = -1;
419 	    switch (p[1])
420 	    {
421 		case '\\': c = '\\'; break;
422 		case '"': c = '"'; break;
423 		case 'b': c = BS; break;
424 		case 't': c = TAB; break;
425 		case 'n': c = NL; break;
426 		case 'f': c = FF; break;
427 		case 'r': c = CAR; break;
428 		case 'u':
429 		    if (reader->js_fill != NULL
430 				     && (int)(reader->js_end - p) < NUMBUFLEN)
431 		    {
432 			reader->js_used = (int)(p - reader->js_buf);
433 			if (reader->js_fill(reader))
434 			{
435 			    p = reader->js_buf + reader->js_used;
436 			    reader->js_end = reader->js_buf
437 						     + STRLEN(reader->js_buf);
438 			}
439 		    }
440 		    nr = 0;
441 		    len = 0;
442 		    vim_str2nr(p + 2, NULL, &len,
443 				     STR2NR_HEX + STR2NR_FORCE, &nr, NULL, 4);
444 		    p += len + 2;
445 		    if (0xd800 <= nr && nr <= 0xdfff
446 			    && (int)(reader->js_end - p) >= 6
447 			    && *p == '\\' && *(p+1) == 'u')
448 		    {
449 			varnumber_T	nr2 = 0;
450 
451 			/* decode surrogate pair: \ud812\u3456 */
452 			len = 0;
453 			vim_str2nr(p + 2, NULL, &len,
454 				     STR2NR_HEX + STR2NR_FORCE, &nr2, NULL, 4);
455 			if (0xdc00 <= nr2 && nr2 <= 0xdfff)
456 			{
457 			    p += len + 2;
458 			    nr = (((nr - 0xd800) << 10) |
459 				((nr2 - 0xdc00) & 0x3ff)) + 0x10000;
460 			}
461 		    }
462 		    if (res != NULL)
463 		    {
464 #ifdef FEAT_MBYTE
465 			char_u	buf[NUMBUFLEN];
466 			buf[utf_char2bytes((int)nr, buf)] = NUL;
467 			ga_concat(&ga, buf);
468 #else
469 			ga_append(&ga, (int)nr);
470 #endif
471 		    }
472 		    break;
473 		default:
474 		    /* not a special char, skip over \ */
475 		    ++p;
476 		    continue;
477 	    }
478 	    if (c > 0)
479 	    {
480 		p += 2;
481 		if (res != NULL)
482 		    ga_append(&ga, c);
483 	    }
484 	}
485 	else
486 	{
487 #ifdef FEAT_MBYTE
488 	    len = utf_ptr2len(p);
489 #else
490 	    len = 1;
491 #endif
492 	    if (res != NULL)
493 	    {
494 		if (ga_grow(&ga, len) == FAIL)
495 		{
496 		    ga_clear(&ga);
497 		    return FAIL;
498 		}
499 		mch_memmove((char *)ga.ga_data + ga.ga_len, p, (size_t)len);
500 		ga.ga_len += len;
501 	    }
502 	    p += len;
503 	}
504     }
505 
506     reader->js_used = (int)(p - reader->js_buf);
507     if (*p == quote)
508     {
509 	++reader->js_used;
510 	if (res != NULL)
511 	{
512 	    ga_append(&ga, NUL);
513 	    res->v_type = VAR_STRING;
514 #if defined(FEAT_MBYTE) && defined(USE_ICONV)
515 	    if (!enc_utf8)
516 	    {
517 		vimconv_T   conv;
518 
519 		/* Convert the utf-8 string to 'encoding'. */
520 		conv.vc_type = CONV_NONE;
521 		convert_setup(&conv, (char_u*)"utf-8", p_enc);
522 		if (conv.vc_type != CONV_NONE)
523 		{
524 		    res->vval.v_string =
525 				      string_convert(&conv, ga.ga_data, NULL);
526 		    vim_free(ga.ga_data);
527 		}
528 		convert_setup(&conv, NULL, NULL);
529 	    }
530 	    else
531 #endif
532 		res->vval.v_string = ga.ga_data;
533 	}
534 	return OK;
535     }
536     if (res != NULL)
537     {
538 	res->v_type = VAR_SPECIAL;
539 	res->vval.v_number = VVAL_NONE;
540 	ga_clear(&ga);
541     }
542     return MAYBE;
543 }
544 
545 typedef enum {
546     JSON_ARRAY,		/* parsing items in an array */
547     JSON_OBJECT_KEY,	/* parsing key of an object */
548     JSON_OBJECT		/* parsing item in an object, after the key */
549 } json_decode_T;
550 
551 typedef struct {
552     json_decode_T jd_type;
553     typval_T	  jd_tv;	/* the list or dict */
554     typval_T	  jd_key_tv;
555     char_u	  *jd_key;
556 } json_dec_item_T;
557 
558 /*
559  * Decode one item and put it in "res".  If "res" is NULL only advance.
560  * Must already have skipped white space.
561  *
562  * Return FAIL for a decoding error (and give an error).
563  * Return MAYBE for an incomplete message.
564  */
565     static int
566 json_decode_item(js_read_T *reader, typval_T *res, int options)
567 {
568     char_u	*p;
569     int		len;
570     int		retval;
571     garray_T	stack;
572     typval_T	item;
573     typval_T	*cur_item;
574     json_dec_item_T *top_item;
575     char_u	key_buf[NUMBUFLEN];
576 
577     ga_init2(&stack, sizeof(json_dec_item_T), 100);
578     cur_item = res;
579     init_tv(&item);
580     if (res != NULL)
581     init_tv(res);
582 
583     fill_numbuflen(reader);
584     p = reader->js_buf + reader->js_used;
585     for (;;)
586     {
587 	top_item = NULL;
588 	if (stack.ga_len > 0)
589 	{
590 	    top_item = ((json_dec_item_T *)stack.ga_data) + stack.ga_len - 1;
591 	    json_skip_white(reader);
592 	    p = reader->js_buf + reader->js_used;
593 	    if (*p == NUL)
594 	    {
595 		retval = MAYBE;
596 		if (top_item->jd_type == JSON_OBJECT)
597 		    /* did get the key, clear it */
598 		    clear_tv(&top_item->jd_key_tv);
599 		goto theend;
600 	    }
601 	    if (top_item->jd_type == JSON_OBJECT_KEY
602 					    || top_item->jd_type == JSON_ARRAY)
603 	    {
604 		/* Check for end of object or array. */
605 		if (*p == (top_item->jd_type == JSON_ARRAY ? ']' : '}'))
606 		{
607 		    ++reader->js_used; /* consume the ']' or '}' */
608 		    --stack.ga_len;
609 		    if (stack.ga_len == 0)
610 		    {
611 			retval = OK;
612 			goto theend;
613 		    }
614 		    if (cur_item != NULL)
615 			cur_item = &top_item->jd_tv;
616 		    goto item_end;
617 		}
618 	    }
619 	}
620 
621 	if (top_item != NULL && top_item->jd_type == JSON_OBJECT_KEY
622 		&& (options & JSON_JS)
623 		&& reader->js_buf[reader->js_used] != '"'
624 		&& reader->js_buf[reader->js_used] != '\'')
625 	{
626 	    char_u *key;
627 
628 	    /* accept an object key that is not in quotes */
629 	    key = p = reader->js_buf + reader->js_used;
630 	    while (*p != NUL && *p != ':' && *p > ' ')
631 		++p;
632 	    if (cur_item != NULL)
633 	    {
634 		cur_item->v_type = VAR_STRING;
635 		cur_item->vval.v_string = vim_strnsave(key, (int)(p - key));
636 		top_item->jd_key = cur_item->vval.v_string;
637 	    }
638 	    reader->js_used += (int)(p - key);
639 	}
640 	else
641 	{
642 	    switch (*p)
643 	    {
644 		case '[': /* start of array */
645 		    if (ga_grow(&stack, 1) == FAIL)
646 		    {
647 			retval = FAIL;
648 			break;
649 		    }
650 		    if (cur_item != NULL && rettv_list_alloc(cur_item) == FAIL)
651 		    {
652 			cur_item->v_type = VAR_SPECIAL;
653 			cur_item->vval.v_number = VVAL_NONE;
654 			retval = FAIL;
655 			break;
656 		    }
657 
658 		    ++reader->js_used; /* consume the '[' */
659 		    top_item = ((json_dec_item_T *)stack.ga_data)
660 								+ stack.ga_len;
661 		    top_item->jd_type = JSON_ARRAY;
662 		    ++stack.ga_len;
663 		    if (cur_item != NULL)
664 		    {
665 			top_item->jd_tv = *cur_item;
666 			cur_item = &item;
667 		    }
668 		    continue;
669 
670 		case '{': /* start of object */
671 		    if (ga_grow(&stack, 1) == FAIL)
672 		    {
673 			retval = FAIL;
674 			break;
675 		    }
676 		    if (cur_item != NULL && rettv_dict_alloc(cur_item) == FAIL)
677 		    {
678 			cur_item->v_type = VAR_SPECIAL;
679 			cur_item->vval.v_number = VVAL_NONE;
680 			retval = FAIL;
681 			break;
682 		    }
683 
684 		    ++reader->js_used; /* consume the '{' */
685 		    top_item = ((json_dec_item_T *)stack.ga_data)
686 								+ stack.ga_len;
687 		    top_item->jd_type = JSON_OBJECT_KEY;
688 		    ++stack.ga_len;
689 		    if (cur_item != NULL)
690 		    {
691 			top_item->jd_tv = *cur_item;
692 			cur_item = &top_item->jd_key_tv;
693 		    }
694 		    continue;
695 
696 		case '"': /* string */
697 		    retval = json_decode_string(reader, cur_item, *p);
698 		    break;
699 
700 		case '\'':
701 		    if (options & JSON_JS)
702 			retval = json_decode_string(reader, cur_item, *p);
703 		    else
704 		    {
705 			EMSG(_(e_invarg));
706 			retval = FAIL;
707 		    }
708 		    break;
709 
710 		case ',': /* comma: empty item */
711 		    if ((options & JSON_JS) == 0)
712 		    {
713 			EMSG(_(e_invarg));
714 			retval = FAIL;
715 			break;
716 		    }
717 		    /* FALLTHROUGH */
718 		case NUL: /* empty */
719 		    if (cur_item != NULL)
720 		    {
721 			cur_item->v_type = VAR_SPECIAL;
722 			cur_item->vval.v_number = VVAL_NONE;
723 		    }
724 		    retval = OK;
725 		    break;
726 
727 		default:
728 		    if (VIM_ISDIGIT(*p) || *p == '-')
729 		    {
730 #ifdef FEAT_FLOAT
731 			char_u  *sp = p;
732 
733 			if (*sp == '-')
734 			{
735 			    ++sp;
736 			    if (*sp == NUL)
737 			    {
738 				retval = MAYBE;
739 				break;
740 			    }
741 			    if (!VIM_ISDIGIT(*sp))
742 			    {
743 				EMSG(_(e_invarg));
744 				retval = FAIL;
745 				break;
746 			    }
747 			}
748 			sp = skipdigits(sp);
749 			if (*sp == '.' || *sp == 'e' || *sp == 'E')
750 			{
751 			    if (cur_item == NULL)
752 			    {
753 				float_T f;
754 
755 				len = string2float(p, &f);
756 			    }
757 			    else
758 			    {
759 				cur_item->v_type = VAR_FLOAT;
760 				len = string2float(p, &cur_item->vval.v_float);
761 			    }
762 			}
763 			else
764 #endif
765 			{
766 			    varnumber_T nr;
767 
768 			    vim_str2nr(reader->js_buf + reader->js_used,
769 				    NULL, &len, 0, /* what */
770 				    &nr, NULL, 0);
771 			    if (cur_item != NULL)
772 			    {
773 				cur_item->v_type = VAR_NUMBER;
774 				cur_item->vval.v_number = nr;
775 			    }
776 			}
777 			reader->js_used += len;
778 			retval = OK;
779 			break;
780 		    }
781 		    if (STRNICMP((char *)p, "false", 5) == 0)
782 		    {
783 			reader->js_used += 5;
784 			if (cur_item != NULL)
785 			{
786 			    cur_item->v_type = VAR_SPECIAL;
787 			    cur_item->vval.v_number = VVAL_FALSE;
788 			}
789 			retval = OK;
790 			break;
791 		    }
792 		    if (STRNICMP((char *)p, "true", 4) == 0)
793 		    {
794 			reader->js_used += 4;
795 			if (cur_item != NULL)
796 			{
797 			    cur_item->v_type = VAR_SPECIAL;
798 			    cur_item->vval.v_number = VVAL_TRUE;
799 			}
800 			retval = OK;
801 			break;
802 		    }
803 		    if (STRNICMP((char *)p, "null", 4) == 0)
804 		    {
805 			reader->js_used += 4;
806 			if (cur_item != NULL)
807 			{
808 			    cur_item->v_type = VAR_SPECIAL;
809 			    cur_item->vval.v_number = VVAL_NULL;
810 			}
811 			retval = OK;
812 			break;
813 		    }
814 #ifdef FEAT_FLOAT
815 		    if (STRNICMP((char *)p, "NaN", 3) == 0)
816 		    {
817 			reader->js_used += 3;
818 			if (cur_item != NULL)
819 			{
820 			    cur_item->v_type = VAR_FLOAT;
821 			    cur_item->vval.v_float = NAN;
822 			}
823 			retval = OK;
824 			break;
825 		    }
826 		    if (STRNICMP((char *)p, "Infinity", 8) == 0)
827 		    {
828 			reader->js_used += 8;
829 			if (cur_item != NULL)
830 			{
831 			    cur_item->v_type = VAR_FLOAT;
832 			    cur_item->vval.v_float = INFINITY;
833 			}
834 			retval = OK;
835 			break;
836 		    }
837 #endif
838 		    /* check for truncated name */
839 		    len = (int)(reader->js_end - (reader->js_buf + reader->js_used));
840 		    if (
841 			    (len < 5 && STRNICMP((char *)p, "false", len) == 0)
842 #ifdef FEAT_FLOAT
843 			    || (len < 8 && STRNICMP((char *)p, "Infinity", len) == 0)
844 			    || (len < 3 && STRNICMP((char *)p, "NaN", len) == 0)
845 #endif
846 			    || (len < 4 && (STRNICMP((char *)p, "true", len) == 0
847 				       ||  STRNICMP((char *)p, "null", len) == 0)))
848 
849 			retval = MAYBE;
850 		    else
851 			retval = FAIL;
852 		    break;
853 	    }
854 
855 	    /* We are finished when retval is FAIL or MAYBE and when at the
856 	     * toplevel. */
857 	    if (retval == FAIL)
858 		break;
859 	    if (retval == MAYBE || stack.ga_len == 0)
860 		goto theend;
861 
862 	    if (top_item != NULL && top_item->jd_type == JSON_OBJECT_KEY
863 		    && cur_item != NULL)
864 	    {
865 		top_item->jd_key = get_tv_string_buf_chk(cur_item, key_buf);
866 		if (top_item->jd_key == NULL)
867 		{
868 		    clear_tv(cur_item);
869 		    EMSG(_(e_invarg));
870 		    retval = FAIL;
871 		    goto theend;
872 		}
873 	    }
874 	}
875 
876 item_end:
877 	top_item = ((json_dec_item_T *)stack.ga_data) + stack.ga_len - 1;
878 	switch (top_item->jd_type)
879 	{
880 	    case JSON_ARRAY:
881 		if (res != NULL)
882 		{
883 		    listitem_T	*li = listitem_alloc();
884 
885 		    if (li == NULL)
886 		    {
887 			clear_tv(cur_item);
888 			retval = FAIL;
889 			goto theend;
890 		    }
891 		    li->li_tv = *cur_item;
892 		    list_append(top_item->jd_tv.vval.v_list, li);
893 		}
894 		if (cur_item != NULL)
895 		    cur_item = &item;
896 
897 		json_skip_white(reader);
898 		p = reader->js_buf + reader->js_used;
899 		if (*p == ',')
900 		    ++reader->js_used;
901 		else if (*p != ']')
902 		{
903 		    if (*p == NUL)
904 			retval = MAYBE;
905 		    else
906 		    {
907 			EMSG(_(e_invarg));
908 			retval = FAIL;
909 		    }
910 		    goto theend;
911 		}
912 		break;
913 
914 	    case JSON_OBJECT_KEY:
915 		json_skip_white(reader);
916 		p = reader->js_buf + reader->js_used;
917 		if (*p != ':')
918 		{
919 		    if (cur_item != NULL)
920 			clear_tv(cur_item);
921 		    if (*p == NUL)
922 			retval = MAYBE;
923 		    else
924 		    {
925 			EMSG(_(e_invarg));
926 			retval = FAIL;
927 		    }
928 		    goto theend;
929 		}
930 		++reader->js_used;
931 		json_skip_white(reader);
932 		top_item->jd_type = JSON_OBJECT;
933 		if (cur_item != NULL)
934 		    cur_item = &item;
935 		break;
936 
937 	    case JSON_OBJECT:
938 		if (cur_item != NULL
939 			&& dict_find(top_item->jd_tv.vval.v_dict,
940 						 top_item->jd_key, -1) != NULL)
941 		{
942 		    EMSG2(_("E938: Duplicate key in JSON: \"%s\""),
943 							     top_item->jd_key);
944 		    clear_tv(&top_item->jd_key_tv);
945 		    clear_tv(cur_item);
946 		    retval = FAIL;
947 		    goto theend;
948 		}
949 
950 		if (cur_item != NULL)
951 		{
952 		    dictitem_T *di = dictitem_alloc(top_item->jd_key);
953 
954 		    clear_tv(&top_item->jd_key_tv);
955 		    if (di == NULL)
956 		    {
957 			clear_tv(cur_item);
958 			retval = FAIL;
959 			goto theend;
960 		    }
961 		    di->di_tv = *cur_item;
962 		    di->di_tv.v_lock = 0;
963 		    if (dict_add(top_item->jd_tv.vval.v_dict, di) == FAIL)
964 		    {
965 			dictitem_free(di);
966 			retval = FAIL;
967 			goto theend;
968 		    }
969 		}
970 
971 		json_skip_white(reader);
972 		p = reader->js_buf + reader->js_used;
973 		if (*p == ',')
974 		    ++reader->js_used;
975 		else if (*p != '}')
976 		{
977 		    if (*p == NUL)
978 			retval = MAYBE;
979 		    else
980 		    {
981 			EMSG(_(e_invarg));
982 			retval = FAIL;
983 		    }
984 		    goto theend;
985 		}
986 		top_item->jd_type = JSON_OBJECT_KEY;
987 		if (cur_item != NULL)
988 		    cur_item = &top_item->jd_key_tv;
989 		break;
990 	}
991     }
992 
993     /* Get here when parsing failed. */
994     if (res != NULL)
995     {
996 	clear_tv(res);
997 	res->v_type = VAR_SPECIAL;
998 	res->vval.v_number = VVAL_NONE;
999     }
1000     EMSG(_(e_invarg));
1001 
1002 theend:
1003     ga_clear(&stack);
1004     return retval;
1005 }
1006 
1007 /*
1008  * Decode the JSON from "reader" and store the result in "res".
1009  * "options" can be JSON_JS or zero;
1010  * Return FAIL if not the whole message was consumed.
1011  */
1012     int
1013 json_decode_all(js_read_T *reader, typval_T *res, int options)
1014 {
1015     int ret;
1016 
1017     /* We find the end once, to avoid calling strlen() many times. */
1018     reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
1019     json_skip_white(reader);
1020     ret = json_decode_item(reader, res, options);
1021     if (ret != OK)
1022     {
1023 	if (ret == MAYBE)
1024 	    EMSG(_(e_invarg));
1025 	return FAIL;
1026     }
1027     json_skip_white(reader);
1028     if (reader->js_buf[reader->js_used] != NUL)
1029     {
1030 	EMSG(_(e_trailing));
1031 	return FAIL;
1032     }
1033     return OK;
1034 }
1035 
1036 /*
1037  * Decode the JSON from "reader" and store the result in "res".
1038  * "options" can be JSON_JS or zero;
1039  * Return FAIL for a decoding error.
1040  * Return MAYBE for an incomplete message.
1041  * Consumes the message anyway.
1042  */
1043     int
1044 json_decode(js_read_T *reader, typval_T *res, int options)
1045 {
1046     int ret;
1047 
1048     /* We find the end once, to avoid calling strlen() many times. */
1049     reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
1050     json_skip_white(reader);
1051     ret = json_decode_item(reader, res, options);
1052     json_skip_white(reader);
1053 
1054     return ret;
1055 }
1056 
1057 /*
1058  * Decode the JSON from "reader" to find the end of the message.
1059  * "options" can be JSON_JS or zero.
1060  * This is only used for testing.
1061  * Return FAIL if the message has a decoding error.
1062  * Return MAYBE if the message is truncated, need to read more.
1063  * This only works reliable if the message contains an object, array or
1064  * string.  A number might be trucated without knowing.
1065  * Does not advance the reader.
1066  */
1067     int
1068 json_find_end(js_read_T *reader, int options)
1069 {
1070     int used_save = reader->js_used;
1071     int ret;
1072 
1073     /* We find the end once, to avoid calling strlen() many times. */
1074     reader->js_end = reader->js_buf + STRLEN(reader->js_buf);
1075     json_skip_white(reader);
1076     ret = json_decode_item(reader, NULL, options);
1077     reader->js_used = used_save;
1078     return ret;
1079 }
1080 #endif
1081