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