1 ///////////////////////////////////////////////////////////////////////////////
2 // \author (c) Marco Paland (info@paland.com)
3 // 2014-2019, PALANDesign Hannover, Germany
4 //
5 // \license The MIT License (MIT)
6 //
7 // Permission is hereby granted, free of charge, to any person obtaining a copy
8 // of this software and associated documentation files (the "Software"), to deal
9 // in the Software without restriction, including without limitation the rights
10 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 // copies of the Software, and to permit persons to whom the Software is
12 // furnished to do so, subject to the following conditions:
13 //
14 // The above copyright notice and this permission notice shall be included in
15 // all copies or substantial portions of the Software.
16 //
17 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 // THE SOFTWARE.
24 //
25 // \brief Tiny printf, sprintf and (v)snprintf implementation, optimized for speed on
26 // embedded systems with a very limited resources. These routines are thread
27 // safe and reentrant!
28 // Use this instead of the bloated standard/newlib printf cause these use
29 // malloc for printf (and may not be thread safe).
30 //
31 ///////////////////////////////////////////////////////////////////////////////
32
33 #include "lv_printf.h"
34
35 #if LV_SPRINTF_CUSTOM == 0
36
37 #include <stdbool.h>
38 #include <stdint.h>
39
40
41 #define PRINTF_DISABLE_SUPPORT_FLOAT LV_SPRINTF_DISABLE_FLOAT
42
43 // 'ntoa' conversion buffer size, this must be big enough to hold one converted
44 // numeric number including padded zeros (dynamically created on stack)
45 // default: 32 byte
46 #ifndef PRINTF_NTOA_BUFFER_SIZE
47 #define PRINTF_NTOA_BUFFER_SIZE 32U
48 #endif
49
50 // 'ftoa' conversion buffer size, this must be big enough to hold one converted
51 // float number including padded zeros (dynamically created on stack)
52 // default: 32 byte
53 #ifndef PRINTF_FTOA_BUFFER_SIZE
54 #define PRINTF_FTOA_BUFFER_SIZE 32U
55 #endif
56
57 // support for the floating point type (%f)
58 // default: activated
59 #if !PRINTF_DISABLE_SUPPORT_FLOAT
60 #define PRINTF_SUPPORT_FLOAT
61 #endif
62
63 // support for exponential floating point notation (%e/%g)
64 // default: activated
65 #ifndef PRINTF_DISABLE_SUPPORT_EXPONENTIAL
66 #define PRINTF_SUPPORT_EXPONENTIAL
67 #endif
68
69 // define the default floating point precision
70 // default: 6 digits
71 #ifndef PRINTF_DEFAULT_FLOAT_PRECISION
72 #define PRINTF_DEFAULT_FLOAT_PRECISION 6U
73 #endif
74
75 // define the largest float suitable to print with %f
76 // default: 1e9
77 #ifndef PRINTF_MAX_FLOAT
78 #define PRINTF_MAX_FLOAT 1e9
79 #endif
80
81 // support for the long long types (%llu or %p)
82 // default: activated
83 #ifndef PRINTF_DISABLE_SUPPORT_LONG_LONG
84 #define PRINTF_SUPPORT_LONG_LONG
85 #endif
86
87 // support for the ptrdiff_t type (%t)
88 // ptrdiff_t is normally defined in <stddef.h> as long or long long type
89 // default: activated
90 #ifndef PRINTF_DISABLE_SUPPORT_PTRDIFF_T
91 #define PRINTF_SUPPORT_PTRDIFF_T
92 #endif
93
94 ///////////////////////////////////////////////////////////////////////////////
95
96 // internal flag definitions
97 #define FLAGS_ZEROPAD (1U << 0U)
98 #define FLAGS_LEFT (1U << 1U)
99 #define FLAGS_PLUS (1U << 2U)
100 #define FLAGS_SPACE (1U << 3U)
101 #define FLAGS_HASH (1U << 4U)
102 #define FLAGS_UPPERCASE (1U << 5U)
103 #define FLAGS_CHAR (1U << 6U)
104 #define FLAGS_SHORT (1U << 7U)
105 #define FLAGS_LONG (1U << 8U)
106 #define FLAGS_LONG_LONG (1U << 9U)
107 #define FLAGS_PRECISION (1U << 10U)
108 #define FLAGS_ADAPT_EXP (1U << 11U)
109
110
111 // import float.h for DBL_MAX
112 #if defined(PRINTF_SUPPORT_FLOAT)
113 #include <float.h>
114 #endif
115
116
117 // output function type
118 typedef void (*out_fct_type)(char character, void * buffer, size_t idx, size_t maxlen);
119
120
121 // wrapper (used as buffer) for output function type
122 typedef struct {
123 void (*fct)(char character, void * arg);
124 void * arg;
125 } out_fct_wrap_type;
126
127
128 // internal buffer output
_out_buffer(char character,void * buffer,size_t idx,size_t maxlen)129 static inline void _out_buffer(char character, void * buffer, size_t idx, size_t maxlen)
130 {
131 if(idx < maxlen) {
132 ((char *)buffer)[idx] = character;
133 }
134 }
135
136
137 // internal null output
_out_null(char character,void * buffer,size_t idx,size_t maxlen)138 static inline void _out_null(char character, void * buffer, size_t idx, size_t maxlen)
139 {
140 (void)character;
141 (void)buffer;
142 (void)idx;
143 (void)maxlen;
144 }
145
146
147
148 // internal secure strlen
149 // \return The length of the string (excluding the terminating 0) limited by 'maxsize'
_strnlen_s(const char * str,size_t maxsize)150 static inline unsigned int _strnlen_s(const char * str, size_t maxsize)
151 {
152 const char * s;
153 for(s = str; *s && maxsize--; ++s);
154 return (unsigned int)(s - str);
155 }
156
157
158 // internal test if char is a digit (0-9)
159 // \return true if char is a digit
_is_digit(char ch)160 static inline bool _is_digit(char ch)
161 {
162 return (ch >= '0') && (ch <= '9');
163 }
164
165
166 // internal ASCII string to unsigned int conversion
_atoi(const char ** str)167 static unsigned int _atoi(const char ** str)
168 {
169 unsigned int i = 0U;
170 while(_is_digit(**str)) {
171 i = i * 10U + (unsigned int)(*((*str)++) - '0');
172 }
173 return i;
174 }
175
176
177 // output the specified string in reverse, taking care of any zero-padding
_out_rev(out_fct_type out,char * buffer,size_t idx,size_t maxlen,const char * buf,size_t len,unsigned int width,unsigned int flags)178 static size_t _out_rev(out_fct_type out, char * buffer, size_t idx, size_t maxlen, const char * buf, size_t len,
179 unsigned int width, unsigned int flags)
180 {
181 const size_t start_idx = idx;
182
183 // pad spaces up to given width
184 if(!(flags & FLAGS_LEFT) && !(flags & FLAGS_ZEROPAD)) {
185 size_t i;
186 for(i = len; i < width; i++) {
187 out(' ', buffer, idx++, maxlen);
188 }
189 }
190
191 // reverse string
192 while(len) {
193 out(buf[--len], buffer, idx++, maxlen);
194 }
195
196 // append pad spaces up to given width
197 if(flags & FLAGS_LEFT) {
198 while(idx - start_idx < width) {
199 out(' ', buffer, idx++, maxlen);
200 }
201 }
202
203 return idx;
204 }
205
206
207 // internal itoa format
_ntoa_format(out_fct_type out,char * buffer,size_t idx,size_t maxlen,char * buf,size_t len,bool negative,unsigned int base,unsigned int prec,unsigned int width,unsigned int flags)208 static size_t _ntoa_format(out_fct_type out, char * buffer, size_t idx, size_t maxlen, char * buf, size_t len,
209 bool negative, unsigned int base, unsigned int prec, unsigned int width, unsigned int flags)
210 {
211 // pad leading zeros
212 if(!(flags & FLAGS_LEFT)) {
213 if(width && (flags & FLAGS_ZEROPAD) && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) {
214 width--;
215 }
216 while((len < prec) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
217 buf[len++] = '0';
218 }
219 while((flags & FLAGS_ZEROPAD) && (len < width) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
220 buf[len++] = '0';
221 }
222 }
223
224 // handle hash
225 if(flags & FLAGS_HASH) {
226 if(!(flags & FLAGS_PRECISION) && len && ((len == prec) || (len == width))) {
227 len--;
228 if(len && (base == 16U)) {
229 len--;
230 }
231 }
232 if((base == 16U) && !(flags & FLAGS_UPPERCASE) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
233 buf[len++] = 'x';
234 }
235 else if((base == 16U) && (flags & FLAGS_UPPERCASE) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
236 buf[len++] = 'X';
237 }
238 else if((base == 2U) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
239 buf[len++] = 'b';
240 }
241 if(len < PRINTF_NTOA_BUFFER_SIZE) {
242 buf[len++] = '0';
243 }
244 }
245
246 if(len < PRINTF_NTOA_BUFFER_SIZE) {
247 if(negative) {
248 buf[len++] = '-';
249 }
250 else if(flags & FLAGS_PLUS) {
251 buf[len++] = '+'; // ignore the space if the '+' exists
252 }
253 else if(flags & FLAGS_SPACE) {
254 buf[len++] = ' ';
255 }
256 }
257
258 return _out_rev(out, buffer, idx, maxlen, buf, len, width, flags);
259 }
260
261
262 // internal itoa for 'long' type
_ntoa_long(out_fct_type out,char * buffer,size_t idx,size_t maxlen,unsigned long value,bool negative,unsigned long base,unsigned int prec,unsigned int width,unsigned int flags)263 static size_t _ntoa_long(out_fct_type out, char * buffer, size_t idx, size_t maxlen, unsigned long value, bool negative,
264 unsigned long base, unsigned int prec, unsigned int width, unsigned int flags)
265 {
266 char buf[PRINTF_NTOA_BUFFER_SIZE];
267 size_t len = 0U;
268
269 // no hash for 0 values
270 if(!value) {
271 flags &= ~FLAGS_HASH;
272 }
273
274 // write if precision != 0 and value is != 0
275 if(!(flags & FLAGS_PRECISION) || value) {
276 do {
277 const char digit = (char)(value % base);
278 buf[len++] = digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10;
279 value /= base;
280 } while(value && (len < PRINTF_NTOA_BUFFER_SIZE));
281 }
282
283 return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, prec, width, flags);
284 }
285
286
287 // internal itoa for 'long long' type
288 #if defined(PRINTF_SUPPORT_LONG_LONG)
_ntoa_long_long(out_fct_type out,char * buffer,size_t idx,size_t maxlen,unsigned long long value,bool negative,unsigned long long base,unsigned int prec,unsigned int width,unsigned int flags)289 static size_t _ntoa_long_long(out_fct_type out, char * buffer, size_t idx, size_t maxlen, unsigned long long value,
290 bool negative, unsigned long long base, unsigned int prec, unsigned int width, unsigned int flags)
291 {
292 char buf[PRINTF_NTOA_BUFFER_SIZE];
293 size_t len = 0U;
294
295 // no hash for 0 values
296 if(!value) {
297 flags &= ~FLAGS_HASH;
298 }
299
300 // write if precision != 0 and value is != 0
301 if(!(flags & FLAGS_PRECISION) || value) {
302 do {
303 const char digit = (char)(value % base);
304 buf[len++] = digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10;
305 value /= base;
306 } while(value && (len < PRINTF_NTOA_BUFFER_SIZE));
307 }
308
309 return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, prec, width, flags);
310 }
311 #endif // PRINTF_SUPPORT_LONG_LONG
312
313
314 #if defined(PRINTF_SUPPORT_FLOAT)
315
316 #if defined(PRINTF_SUPPORT_EXPONENTIAL)
317 // forward declaration so that _ftoa can switch to exp notation for values > PRINTF_MAX_FLOAT
318 static size_t _etoa(out_fct_type out, char * buffer, size_t idx, size_t maxlen, double value, unsigned int prec,
319 unsigned int width, unsigned int flags);
320 #endif
321
322
323 // internal ftoa for fixed decimal floating point
_ftoa(out_fct_type out,char * buffer,size_t idx,size_t maxlen,double value,unsigned int prec,unsigned int width,unsigned int flags)324 static size_t _ftoa(out_fct_type out, char * buffer, size_t idx, size_t maxlen, double value, unsigned int prec,
325 unsigned int width, unsigned int flags)
326 {
327 char buf[PRINTF_FTOA_BUFFER_SIZE];
328 size_t len = 0U;
329 double diff = 0.0;
330
331 // powers of 10
332 static const double pow10[] = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 };
333
334 // test for special values
335 if(value != value)
336 return _out_rev(out, buffer, idx, maxlen, "nan", 3, width, flags);
337 if(value < -DBL_MAX)
338 return _out_rev(out, buffer, idx, maxlen, "fni-", 4, width, flags);
339 if(value > DBL_MAX)
340 return _out_rev(out, buffer, idx, maxlen, (flags & FLAGS_PLUS) ? "fni+" : "fni", (flags & FLAGS_PLUS) ? 4U : 3U, width,
341 flags);
342
343 // test for very large values
344 // standard printf behavior is to print EVERY whole number digit -- which could be 100s of characters overflowing your buffers == bad
345 if((value > PRINTF_MAX_FLOAT) || (value < -PRINTF_MAX_FLOAT)) {
346 #if defined(PRINTF_SUPPORT_EXPONENTIAL)
347 return _etoa(out, buffer, idx, maxlen, value, prec, width, flags);
348 #else
349 return 0U;
350 #endif
351 }
352
353 // test for negative
354 bool negative = false;
355 if(value < 0) {
356 negative = true;
357 value = 0 - value;
358 }
359
360 // set default precision, if not set explicitly
361 if(!(flags & FLAGS_PRECISION)) {
362 prec = PRINTF_DEFAULT_FLOAT_PRECISION;
363 }
364 // limit precision to 9, cause a prec >= 10 can lead to overflow errors
365 while((len < PRINTF_FTOA_BUFFER_SIZE) && (prec > 9U)) {
366 buf[len++] = '0';
367 prec--;
368 }
369
370 int whole = (int)value;
371 double tmp = (value - whole) * pow10[prec];
372 unsigned long frac = (unsigned long)tmp;
373 diff = tmp - frac;
374
375 if(diff > 0.5) {
376 ++frac;
377 // handle rollover, e.g. case 0.99 with prec 1 is 1.0
378 if(frac >= pow10[prec]) {
379 frac = 0;
380 ++whole;
381 }
382 }
383 else if(diff < 0.5) {
384 }
385 else if((frac == 0U) || (frac & 1U)) {
386 // if halfway, round up if odd OR if last digit is 0
387 ++frac;
388 }
389
390 if(prec == 0U) {
391 diff = value - (double)whole;
392 if((!(diff < 0.5) || (diff > 0.5)) && (whole & 1)) {
393 // exactly 0.5 and ODD, then round up
394 // 1.5 -> 2, but 2.5 -> 2
395 ++whole;
396 }
397 }
398 else {
399 unsigned int count = prec;
400 // now do fractional part, as an unsigned number
401 while(len < PRINTF_FTOA_BUFFER_SIZE) {
402 --count;
403 buf[len++] = (char)(48U + (frac % 10U));
404 if(!(frac /= 10U)) {
405 break;
406 }
407 }
408 // add extra 0s
409 while((len < PRINTF_FTOA_BUFFER_SIZE) && (count-- > 0U)) {
410 buf[len++] = '0';
411 }
412 if(len < PRINTF_FTOA_BUFFER_SIZE) {
413 // add decimal
414 buf[len++] = '.';
415 }
416 }
417
418 // do whole part, number is reversed
419 while(len < PRINTF_FTOA_BUFFER_SIZE) {
420 buf[len++] = (char)(48 + (whole % 10));
421 if(!(whole /= 10)) {
422 break;
423 }
424 }
425
426 // pad leading zeros
427 if(!(flags & FLAGS_LEFT) && (flags & FLAGS_ZEROPAD)) {
428 if(width && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) {
429 width--;
430 }
431 while((len < width) && (len < PRINTF_FTOA_BUFFER_SIZE)) {
432 buf[len++] = '0';
433 }
434 }
435
436 if(len < PRINTF_FTOA_BUFFER_SIZE) {
437 if(negative) {
438 buf[len++] = '-';
439 }
440 else if(flags & FLAGS_PLUS) {
441 buf[len++] = '+'; // ignore the space if the '+' exists
442 }
443 else if(flags & FLAGS_SPACE) {
444 buf[len++] = ' ';
445 }
446 }
447
448 return _out_rev(out, buffer, idx, maxlen, buf, len, width, flags);
449 }
450
451
452 #if defined(PRINTF_SUPPORT_EXPONENTIAL)
453 // internal ftoa variant for exponential floating-point type, contributed by Martijn Jasperse <m.jasperse@gmail.com>
_etoa(out_fct_type out,char * buffer,size_t idx,size_t maxlen,double value,unsigned int prec,unsigned int width,unsigned int flags)454 static size_t _etoa(out_fct_type out, char * buffer, size_t idx, size_t maxlen, double value, unsigned int prec,
455 unsigned int width, unsigned int flags)
456 {
457 // check for NaN and special values
458 if((value != value) || (value > DBL_MAX) || (value < -DBL_MAX)) {
459 return _ftoa(out, buffer, idx, maxlen, value, prec, width, flags);
460 }
461
462 // determine the sign
463 const bool negative = value < 0;
464 if(negative) {
465 value = -value;
466 }
467
468 // default precision
469 if(!(flags & FLAGS_PRECISION)) {
470 prec = PRINTF_DEFAULT_FLOAT_PRECISION;
471 }
472
473 // determine the decimal exponent
474 // based on the algorithm by David Gay (https://www.ampl.com/netlib/fp/dtoa.c)
475 union {
476 uint64_t U;
477 double F;
478 } conv;
479
480 conv.F = value;
481 int exp2 = (int)((conv.U >> 52U) & 0x07FFU) - 1023; // effectively log2
482 conv.U = (conv.U & ((1ULL << 52U) - 1U)) | (1023ULL << 52U); // drop the exponent so conv.F is now in [1,2)
483 // now approximate log10 from the log2 integer part and an expansion of ln around 1.5
484 int expval = (int)(0.1760912590558 + exp2 * 0.301029995663981 + (conv.F - 1.5) * 0.289529654602168);
485 // now we want to compute 10^expval but we want to be sure it won't overflow
486 exp2 = (int)(expval * 3.321928094887362 + 0.5);
487 const double z = expval * 2.302585092994046 - exp2 * 0.6931471805599453;
488 const double z2 = z * z;
489 conv.U = (uint64_t)(exp2 + 1023) << 52U;
490 // compute exp(z) using continued fractions, see https://en.wikipedia.org/wiki/Exponential_function#Continued_fractions_for_ex
491 conv.F *= 1 + 2 * z / (2 - z + (z2 / (6 + (z2 / (10 + z2 / 14)))));
492 // correct for rounding errors
493 if(value < conv.F) {
494 expval--;
495 conv.F /= 10;
496 }
497
498 // the exponent format is "%+03d" and largest value is "307", so set aside 4-5 characters
499 unsigned int minwidth = ((expval < 100) && (expval > -100)) ? 4U : 5U;
500
501 // in "%g" mode, "prec" is the number of *significant figures* not decimals
502 if(flags & FLAGS_ADAPT_EXP) {
503 // do we want to fall-back to "%f" mode?
504 if((value >= 1e-4) && (value < 1e6)) {
505 if((int)prec > expval) {
506 prec = (unsigned)((int)prec - expval - 1);
507 }
508 else {
509 prec = 0;
510 }
511 flags |= FLAGS_PRECISION; // make sure _ftoa respects precision
512 // no characters in exponent
513 minwidth = 0U;
514 expval = 0;
515 }
516 else {
517 // we use one sigfig for the whole part
518 if((prec > 0) && (flags & FLAGS_PRECISION)) {
519 --prec;
520 }
521 }
522 }
523
524 // will everything fit?
525 unsigned int fwidth = width;
526 if(width > minwidth) {
527 // we didn't fall-back so subtract the characters required for the exponent
528 fwidth -= minwidth;
529 }
530 else {
531 // not enough characters, so go back to default sizing
532 fwidth = 0U;
533 }
534 if((flags & FLAGS_LEFT) && minwidth) {
535 // if we're padding on the right, DON'T pad the floating part
536 fwidth = 0U;
537 }
538
539 // rescale the float value
540 if(expval) {
541 value /= conv.F;
542 }
543
544 // output the floating part
545 const size_t start_idx = idx;
546 idx = _ftoa(out, buffer, idx, maxlen, negative ? -value : value, prec, fwidth, flags & ~FLAGS_ADAPT_EXP);
547
548 // output the exponent part
549 if(minwidth) {
550 // output the exponential symbol
551 out((flags & FLAGS_UPPERCASE) ? 'E' : 'e', buffer, idx++, maxlen);
552 // output the exponent value
553 idx = _ntoa_long(out, buffer, idx, maxlen, (expval < 0) ? -expval : expval, expval < 0, 10, 0, minwidth - 1,
554 FLAGS_ZEROPAD | FLAGS_PLUS);
555 // might need to right-pad spaces
556 if(flags & FLAGS_LEFT) {
557 while(idx - start_idx < width) out(' ', buffer, idx++, maxlen);
558 }
559 }
560 return idx;
561 }
562 #endif // PRINTF_SUPPORT_EXPONENTIAL
563 #endif // PRINTF_SUPPORT_FLOAT
564
565
566 // internal vsnprintf
_vsnprintf(out_fct_type out,char * buffer,const size_t maxlen,const char * format,va_list va)567 static int _vsnprintf(out_fct_type out, char * buffer, const size_t maxlen, const char * format, va_list va)
568 {
569 unsigned int flags, width, precision, n;
570 size_t idx = 0U;
571
572 if(!buffer) {
573 // use null output function
574 out = _out_null;
575 }
576
577 while(*format) {
578 // format specifier? %[flags][width][.precision][length]
579 if(*format != '%') {
580 // no
581 out(*format, buffer, idx++, maxlen);
582 format++;
583 continue;
584 }
585 else {
586 // yes, evaluate it
587 format++;
588 }
589
590 // evaluate flags
591 flags = 0U;
592 do {
593 switch(*format) {
594 case '0':
595 flags |= FLAGS_ZEROPAD;
596 format++;
597 n = 1U;
598 break;
599 case '-':
600 flags |= FLAGS_LEFT;
601 format++;
602 n = 1U;
603 break;
604 case '+':
605 flags |= FLAGS_PLUS;
606 format++;
607 n = 1U;
608 break;
609 case ' ':
610 flags |= FLAGS_SPACE;
611 format++;
612 n = 1U;
613 break;
614 case '#':
615 flags |= FLAGS_HASH;
616 format++;
617 n = 1U;
618 break;
619 default :
620 n = 0U;
621 break;
622 }
623 } while(n);
624
625 // evaluate width field
626 width = 0U;
627 if(_is_digit(*format)) {
628 width = _atoi(&format);
629 }
630 else if(*format == '*') {
631 const int w = va_arg(va, int);
632 if(w < 0) {
633 flags |= FLAGS_LEFT; // reverse padding
634 width = (unsigned int) - w;
635 }
636 else {
637 width = (unsigned int)w;
638 }
639 format++;
640 }
641
642 // evaluate precision field
643 precision = 0U;
644 if(*format == '.') {
645 flags |= FLAGS_PRECISION;
646 format++;
647 if(_is_digit(*format)) {
648 precision = _atoi(&format);
649 }
650 else if(*format == '*') {
651 const int prec = (int)va_arg(va, int);
652 precision = prec > 0 ? (unsigned int)prec : 0U;
653 format++;
654 }
655 }
656
657 // evaluate length field
658 switch(*format) {
659 case 'l' :
660 flags |= FLAGS_LONG;
661 format++;
662 if(*format == 'l') {
663 flags |= FLAGS_LONG_LONG;
664 format++;
665 }
666 break;
667 case 'h' :
668 flags |= FLAGS_SHORT;
669 format++;
670 if(*format == 'h') {
671 flags |= FLAGS_CHAR;
672 format++;
673 }
674 break;
675 #if defined(PRINTF_SUPPORT_PTRDIFF_T)
676 case 't' :
677 flags |= (sizeof(ptrdiff_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
678 format++;
679 break;
680 #endif
681 case 'j' :
682 flags |= (sizeof(intmax_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
683 format++;
684 break;
685 case 'z' :
686 flags |= (sizeof(size_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
687 format++;
688 break;
689 default :
690 break;
691 }
692
693 // evaluate specifier
694 switch(*format) {
695 case 'd' :
696 case 'i' :
697 case 'u' :
698 case 'x' :
699 case 'X' :
700 case 'o' :
701 case 'b' : {
702 // set the base
703 unsigned int base;
704 if(*format == 'x' || *format == 'X') {
705 base = 16U;
706 }
707 else if(*format == 'o') {
708 base = 8U;
709 }
710 else if(*format == 'b') {
711 base = 2U;
712 }
713 else {
714 base = 10U;
715 flags &= ~FLAGS_HASH; // no hash for dec format
716 }
717 // uppercase
718 if(*format == 'X') {
719 flags |= FLAGS_UPPERCASE;
720 }
721
722 // no plus or space flag for u, x, X, o, b
723 if((*format != 'i') && (*format != 'd')) {
724 flags &= ~(FLAGS_PLUS | FLAGS_SPACE);
725 }
726
727 // ignore '0' flag when precision is given
728 if(flags & FLAGS_PRECISION) {
729 flags &= ~FLAGS_ZEROPAD;
730 }
731
732 // convert the integer
733 if((*format == 'i') || (*format == 'd')) {
734 // signed
735 if(flags & FLAGS_LONG_LONG) {
736 #if defined(PRINTF_SUPPORT_LONG_LONG)
737 const long long value = va_arg(va, long long);
738 idx = _ntoa_long_long(out, buffer, idx, maxlen, (unsigned long long)(value > 0 ? value : 0 - value), value < 0, base,
739 precision, width, flags);
740 #endif
741 }
742 else if(flags & FLAGS_LONG) {
743 const long value = va_arg(va, long);
744 idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)(value > 0 ? value : 0 - value), value < 0, base, precision,
745 width, flags);
746 }
747 else {
748 const int value = (flags & FLAGS_CHAR) ? (char)va_arg(va, int) : (flags & FLAGS_SHORT) ? (short int)va_arg(va,
749 int) : va_arg(va, int);
750 idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned int)(value > 0 ? value : 0 - value), value < 0, base, precision,
751 width, flags);
752 }
753 }
754 else {
755 // unsigned
756 if(flags & FLAGS_LONG_LONG) {
757 #if defined(PRINTF_SUPPORT_LONG_LONG)
758 idx = _ntoa_long_long(out, buffer, idx, maxlen, va_arg(va, unsigned long long), false, base, precision, width, flags);
759 #endif
760 }
761 else if(flags & FLAGS_LONG) {
762 idx = _ntoa_long(out, buffer, idx, maxlen, va_arg(va, unsigned long), false, base, precision, width, flags);
763 }
764 else {
765 const unsigned int value = (flags & FLAGS_CHAR) ? (unsigned char)va_arg(va,
766 unsigned int) : (flags & FLAGS_SHORT) ? (unsigned short int)va_arg(va, unsigned int) : va_arg(va, unsigned int);
767 idx = _ntoa_long(out, buffer, idx, maxlen, value, false, base, precision, width, flags);
768 }
769 }
770 format++;
771 break;
772 }
773 #if defined(PRINTF_SUPPORT_FLOAT)
774 case 'f' :
775 case 'F' :
776 if(*format == 'F') flags |= FLAGS_UPPERCASE;
777 idx = _ftoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags);
778 format++;
779 break;
780 #if defined(PRINTF_SUPPORT_EXPONENTIAL)
781 case 'e':
782 case 'E':
783 case 'g':
784 case 'G':
785 if((*format == 'g') || (*format == 'G')) flags |= FLAGS_ADAPT_EXP;
786 if((*format == 'E') || (*format == 'G')) flags |= FLAGS_UPPERCASE;
787 idx = _etoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags);
788 format++;
789 break;
790 #endif // PRINTF_SUPPORT_EXPONENTIAL
791 #endif // PRINTF_SUPPORT_FLOAT
792 case 'c' : {
793 unsigned int l = 1U;
794 // pre padding
795 if(!(flags & FLAGS_LEFT)) {
796 while(l++ < width) {
797 out(' ', buffer, idx++, maxlen);
798 }
799 }
800 // char output
801 out((char)va_arg(va, int), buffer, idx++, maxlen);
802 // post padding
803 if(flags & FLAGS_LEFT) {
804 while(l++ < width) {
805 out(' ', buffer, idx++, maxlen);
806 }
807 }
808 format++;
809 break;
810 }
811
812 case 's' : {
813 const char * p = va_arg(va, char *);
814 unsigned int l = _strnlen_s(p, precision ? precision : (size_t) -1);
815 // pre padding
816 if(flags & FLAGS_PRECISION) {
817 l = (l < precision ? l : precision);
818 }
819 if(!(flags & FLAGS_LEFT)) {
820 while(l++ < width) {
821 out(' ', buffer, idx++, maxlen);
822 }
823 }
824 // string output
825 while((*p != 0) && (!(flags & FLAGS_PRECISION) || precision--)) {
826 out(*(p++), buffer, idx++, maxlen);
827 }
828 // post padding
829 if(flags & FLAGS_LEFT) {
830 while(l++ < width) {
831 out(' ', buffer, idx++, maxlen);
832 }
833 }
834 format++;
835 break;
836 }
837
838 case 'p' : {
839 width = sizeof(void *) * 2U;
840 flags |= FLAGS_ZEROPAD | FLAGS_UPPERCASE;
841 #if defined(PRINTF_SUPPORT_LONG_LONG)
842 const bool is_ll = sizeof(uintptr_t) == sizeof(long long);
843 if(is_ll) {
844 idx = _ntoa_long_long(out, buffer, idx, maxlen, (uintptr_t)va_arg(va, void *), false, 16U, precision, width, flags);
845 }
846 else {
847 #endif
848 idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)((uintptr_t)va_arg(va, void *)), false, 16U, precision, width,
849 flags);
850 #if defined(PRINTF_SUPPORT_LONG_LONG)
851 }
852 #endif
853 format++;
854 break;
855 }
856
857 case '%' :
858 out('%', buffer, idx++, maxlen);
859 format++;
860 break;
861
862 default :
863 out(*format, buffer, idx++, maxlen);
864 format++;
865 break;
866 }
867 }
868
869 // termination
870 out((char)0, buffer, idx < maxlen ? idx : maxlen - 1U, maxlen);
871
872 // return written chars without terminating \0
873 return (int)idx;
874 }
875
876
877 ///////////////////////////////////////////////////////////////////////////////
878
lv_snprintf(char * buffer,size_t count,const char * format,...)879 int lv_snprintf(char * buffer, size_t count, const char * format, ...)
880 {
881 va_list va;
882 va_start(va, format);
883 const int ret = _vsnprintf(_out_buffer, buffer, count, format, va);
884 va_end(va);
885 return ret;
886 }
887
lv_vsnprintf(char * buffer,size_t count,const char * format,va_list va)888 int lv_vsnprintf(char * buffer, size_t count, const char * format, va_list va)
889 {
890 return _vsnprintf(_out_buffer, buffer, count, format, va);
891 }
892
893 #endif /*LV_SPRINTF_CUSTOM*/
894
895
