summaryrefslogtreecommitdiffstats
path: root/libc/bionic/debug_format.cpp
blob: e8d6a45cdcef15e674d4d8d366236aa812c82ee9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
/*
 * Copyright (C) 2010 The Android Open Source Project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

// Temporarily disable _FORTIFY_SOURCE to get this code to
// compile under GCC 4.7
#undef _FORTIFY_SOURCE

#include "debug_format.h"

#include <assert.h>
#include <errno.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>

/* define UNIT_TESTS to build this file as a single executable that runs
 * the formatter's unit tests
 */
#define xxUNIT_TESTS

/*** Generic output sink
 ***/

struct Out {
  void *opaque;
  void (*send)(void *opaque, const char *data, int len);
};

static void out_send(Out *o, const char *data, size_t len) {
    o->send(o->opaque, data, (int)len);
}

static void
out_send_repeat(Out *o, char ch, int count)
{
    char pad[8];
    const int padSize = (int)sizeof(pad);

    memset(pad, ch, sizeof(pad));
    while (count > 0) {
        int avail = count;
        if (avail > padSize) {
            avail = padSize;
        }
        o->send(o->opaque, pad, avail);
        count -= avail;
    }
}

/* forward declaration */
static void out_vformat(Out* o, const char* format, va_list args);

/*** Bounded buffer output
 ***/

struct BufOut {
  Out out[1];
  char *buffer;
  char *pos;
  char *end;
  int total;
};

static void buf_out_send(void *opaque, const char *data, int len) {
    BufOut *bo = reinterpret_cast<BufOut*>(opaque);

    if (len < 0) {
        len = strlen(data);
    }

    bo->total += len;

    while (len > 0) {
        int avail = bo->end - bo->pos;
        if (avail == 0)
            break;
        if (avail > len)
            avail = len;
        memcpy(bo->pos, data, avail);
        bo->pos += avail;
        bo->pos[0] = '\0';
        len -= avail;
    }
}

static Out*
buf_out_init(BufOut *bo, char *buffer, size_t size)
{
    if (size == 0)
        return NULL;

    bo->out->opaque = bo;
    bo->out->send   = buf_out_send;
    bo->buffer      = buffer;
    bo->end         = buffer + size - 1;
    bo->pos         = bo->buffer;
    bo->pos[0]      = '\0';
    bo->total       = 0;

    return bo->out;
}

static int
buf_out_length(BufOut *bo)
{
    return bo->total;
}

static int
vformat_buffer(char *buff, size_t buffsize, const char *format, va_list args)
{
    BufOut bo;
    Out *out;

    out = buf_out_init(&bo, buff, buffsize);
    if (out == NULL)
        return 0;

    out_vformat(out, format, args);

    return buf_out_length(&bo);
}

int __libc_format_buffer(char* buffer, size_t buffer_size, const char* format, ...) {
  va_list args;
  va_start(args, format);
  int result = vformat_buffer(buffer, buffer_size, format, args);
  va_end(args);
  return result;
}


/*** File descriptor output
 ***/

struct FdOut {
  Out out[1];
  int fd;
  int total;
};

static void
fd_out_send(void *opaque, const char *data, int len)
{
    FdOut *fdo = reinterpret_cast<FdOut*>(opaque);

    if (len < 0)
        len = strlen(data);

    while (len > 0) {
        int ret = write(fdo->fd, data, len);
        if (ret < 0) {
            if (errno == EINTR)
                continue;
            break;
        }
        data += ret;
        len -= ret;
        fdo->total += ret;
    }
}

static Out*
fd_out_init(FdOut *fdo, int  fd)
{
    fdo->out->opaque = fdo;
    fdo->out->send = fd_out_send;
    fdo->fd = fd;
    fdo->total = 0;

    return fdo->out;
}

static int
fd_out_length(FdOut *fdo)
{
    return fdo->total;
}


int __libc_format_fd(int fd, const char* format, ...) {
  FdOut fdo;
  Out* out = fd_out_init(&fdo, fd);
  if (out == NULL) {
    return 0;
  }

  va_list args;
  va_start(args, format);
  out_vformat(out, format, args);
  va_end(args);

  return fd_out_length(&fdo);
}

/*** Log output
 ***/

#include <unistd.h>
#include <fcntl.h>
#include <sys/uio.h>

int __libc_format_log_va_list(int priority, const char* tag, const char* fmt, va_list args) {
  char buf[1024];
  int result = vformat_buffer(buf, sizeof buf, fmt, args);

  static int log_fd = -1;
  if (log_fd == -1) {
    log_fd = open("/dev/log/main", O_WRONLY);
    if (log_fd == -1) {
      return result;
    }
  }

  struct iovec vec[3];
  vec[0].iov_base = (unsigned char *) &priority;
  vec[0].iov_len = 1;
  vec[1].iov_base = (void *) tag;
  vec[1].iov_len = strlen(tag) + 1;
  vec[2].iov_base = (void *) buf;
  vec[2].iov_len = strlen(buf) + 1;

  TEMP_FAILURE_RETRY(writev(log_fd, vec, 3));

  return result;
}

int __libc_format_log(int priority, const char* tag, const char* format, ...) {
  va_list args;
  va_start(args, format);
  int result = __libc_format_log_va_list(priority, tag, format, args);
  va_end(args);
  return result;
}

/*** formatted output implementation
 ***/

/* Parse a decimal string from 'format + *ppos',
 * return the value, and writes the new position past
 * the decimal string in '*ppos' on exit.
 *
 * NOTE: Does *not* handle a sign prefix.
 */
static unsigned
parse_decimal(const char *format, int *ppos)
{
    const char* p = format + *ppos;
    unsigned result = 0;

    for (;;) {
        int ch = *p;
        unsigned d = (unsigned)(ch - '0');

        if (d >= 10U)
            break;

        result = result*10 + d;
        p++;
    }
    *ppos = p - format;
    return result;
}

// Writes number 'value' in base 'base' into buffer 'buf' of size 'buf_size' bytes.
// Assumes that buf_size > 0.
static void format_number(char* buf, size_t buf_size, uint64_t value, int base, bool caps) {
  char* p = buf;
  char* end = buf + buf_size - 1;

  // Generate digit string in reverse order.
  while (value) {
    unsigned d = value % base;
    value /= base;
    if (p != end) {
      char ch;
      if (d < 10) {
        ch = '0' + d;
      } else {
        ch = (caps ? 'A' : 'a') + (d - 10);
      }
      *p++ = ch;
    }
  }

  // Special case for 0.
  if (p == buf) {
    if (p != end) {
      *p++ = '0';
    }
  }
  *p = '\0';

  // Reverse digit string in-place.
  size_t length = p - buf;
  for (size_t i = 0, j = length - 1; i < j; ++i, --j) {
    char ch = buf[i];
    buf[i] = buf[j];
    buf[j] = ch;
  }
}

/* Write an integer (octal or decimal) into a buffer, assumes buffsize > 2 */
static void
format_integer(char *buffer, size_t buffsize, uint64_t value, int base, int isSigned)
{
    // TODO: this is incorrect for MIN_INT.
    if (isSigned && (int64_t)value < 0) {
        buffer[0] = '-';
        buffer += 1;
        buffsize -= 1;
        value = (uint64_t)(-(int64_t)value);
    }

    format_number(buffer, buffsize, value, base, false);
}

// Assumes buf_size > 2.
static void format_hex(char* buf, size_t buf_size, uint64_t value, bool caps) {
  format_number(buf, buf_size, value, 16, caps);
}


/* Perform formatted output to an output target 'o' */
static void
out_vformat(Out *o, const char *format, va_list args)
{
    int nn = 0;

    for (;;) {
        int mm;
        int padZero = 0;
        int padLeft = 0;
        char sign = '\0';
        int width = -1;
        int prec  = -1;
        size_t bytelen = sizeof(int);
        const char*  str;
        int slen;
        char buffer[32];  /* temporary buffer used to format numbers */

        char  c;

        /* first, find all characters that are not 0 or '%' */
        /* then send them to the output directly */
        mm = nn;
        do {
            c = format[mm];
            if (c == '\0' || c == '%')
                break;
            mm++;
        } while (1);

        if (mm > nn) {
            out_send(o, format+nn, mm-nn);
            nn = mm;
        }

        /* is this it ? then exit */
        if (c == '\0')
            break;

        /* nope, we are at a '%' modifier */
        nn++;  // skip it

        /* parse flags */
        for (;;) {
            c = format[nn++];
            if (c == '\0') {  /* single trailing '%' ? */
                c = '%';
                out_send(o, &c, 1);
                return;
            }
            else if (c == '0') {
                padZero = 1;
                continue;
            }
            else if (c == '-') {
                padLeft = 1;
                continue;
            }
            else if (c == ' ' || c == '+') {
                sign = c;
                continue;
            }
            break;
        }

        /* parse field width */
        if ((c >= '0' && c <= '9')) {
            nn --;
            width = (int)parse_decimal(format, &nn);
            c = format[nn++];
        }

        /* parse precision */
        if (c == '.') {
            prec = (int)parse_decimal(format, &nn);
            c = format[nn++];
        }

        /* length modifier */
        switch (c) {
        case 'h':
            bytelen = sizeof(short);
            if (format[nn] == 'h') {
                bytelen = sizeof(char);
                nn += 1;
            }
            c = format[nn++];
            break;
        case 'l':
            bytelen = sizeof(long);
            if (format[nn] == 'l') {
                bytelen = sizeof(long long);
                nn += 1;
            }
            c = format[nn++];
            break;
        case 'z':
            bytelen = sizeof(size_t);
            c = format[nn++];
            break;
        case 't':
            bytelen = sizeof(ptrdiff_t);
            c = format[nn++];
            break;
        default:
            ;
        }

        /* conversion specifier */
        if (c == 's') {
            /* string */
            str = va_arg(args, const char*);
        } else if (c == 'c') {
            /* character */
            /* NOTE: char is promoted to int when passed through the stack */
            buffer[0] = (char) va_arg(args, int);
            buffer[1] = '\0';
            str = buffer;
        } else if (c == 'p') {
            uint64_t  value = (uintptr_t) va_arg(args, void*);
            buffer[0] = '0';
            buffer[1] = 'x';
            format_hex(buffer + 2, sizeof buffer-2, value, false);
            str = buffer;
        } else {
            /* integers - first read value from stack */
            uint64_t value;
            int isSigned = (c == 'd' || c == 'i' || c == 'o');

            /* NOTE: int8_t and int16_t are promoted to int when passed
             *       through the stack
             */
            switch (bytelen) {
            case 1: value = (uint8_t)  va_arg(args, int); break;
            case 2: value = (uint16_t) va_arg(args, int); break;
            case 4: value = va_arg(args, uint32_t); break;
            case 8: value = va_arg(args, uint64_t); break;
            default: return;  /* should not happen */
            }

            /* sign extension, if needed */
            if (isSigned) {
                int shift = 64 - 8*bytelen;
                value = (uint64_t)(((int64_t)(value << shift)) >> shift);
            }

            /* format the number properly into our buffer */
            switch (c) {
            case 'i': case 'd':
                format_integer(buffer, sizeof buffer, value, 10, isSigned);
                break;
            case 'o':
                format_integer(buffer, sizeof buffer, value, 8, isSigned);
                break;
            case 'x': case 'X':
                format_hex(buffer, sizeof buffer, value, (c == 'X'));
                break;
            default:
                buffer[0] = '\0';
            }
            /* then point to it */
            str = buffer;
        }

        /* if we are here, 'str' points to the content that must be
         * outputted. handle padding and alignment now */

        slen = strlen(str);

        if (sign != '\0' || prec != -1) {
            __assert(__FILE__, __LINE__, "sign/precision unsupported");
        }

        if (slen < width && !padLeft) {
            char padChar = padZero ? '0' : ' ';
            out_send_repeat(o, padChar, width - slen);
        }

        out_send(o, str, slen);

        if (slen < width && padLeft) {
            char padChar = padZero ? '0' : ' ';
            out_send_repeat(o, padChar, width - slen);
        }
    }
}


#ifdef UNIT_TESTS

#include <stdio.h>

static int   gFails = 0;

#define  MARGIN  40

#define  UTEST_CHECK(condition,message) \
    printf("Checking %-*s: ", MARGIN, message); fflush(stdout); \
    if (!(condition)) { \
        printf("KO\n"); \
        gFails += 1; \
    } else { \
        printf("ok\n"); \
    }

static void
utest_BufOut(void)
{
    char buffer[16];
    BufOut bo[1];
    Out* out;
    int ret;

    buffer[0] = '1';
    out = buf_out_init(bo, buffer, sizeof buffer);
    UTEST_CHECK(buffer[0] == '\0', "buf_out_init clears initial byte");
    out_send(out, "abc", 3);
    UTEST_CHECK(!memcmp(buffer, "abc", 4), "out_send() works with BufOut");
    out_send_repeat(out, 'X', 4);
    UTEST_CHECK(!memcmp(buffer, "abcXXXX", 8), "out_send_repeat() works with BufOut");
    buffer[sizeof buffer-1] = 'x';
    out_send_repeat(out, 'Y', 2*sizeof(buffer));
    UTEST_CHECK(buffer[sizeof buffer-1] == '\0', "overflows always zero-terminates");

    out = buf_out_init(bo, buffer, sizeof buffer);
    out_send_repeat(out, 'X', 2*sizeof(buffer));
    ret = buf_out_length(bo);
    UTEST_CHECK(ret == 2*sizeof(buffer), "correct size returned on overflow");
}

static void
utest_expect(const char*  result, const char*  format, ...)
{
    va_list args;
    BufOut bo[1];
    char buffer[256];
    Out* out = buf_out_init(bo, buffer, sizeof buffer);

    printf("Checking %-*s: ", MARGIN, format); fflush(stdout);
    va_start(args, format);
    out_vformat(out, format, args);
    va_end(args);

    if (strcmp(result, buffer)) {
        printf("KO. got '%s' expecting '%s'\n", buffer, result);
        gFails += 1;
    } else {
        printf("ok. got '%s'\n", result);
    }
}

int  main(void)
{
    utest_BufOut();
    utest_expect("", "");
    utest_expect("a", "a");
    utest_expect("01234", "01234", "");
    utest_expect("01234", "%s", "01234");
    utest_expect("aabbcc", "aa%scc", "bb");
    utest_expect("a", "%c", 'a');
    utest_expect("1234", "%d", 1234);
    utest_expect("-8123", "%d", -8123);
    utest_expect("16", "%hd", 0x7fff0010);
    utest_expect("16", "%hhd", 0x7fffff10);
    utest_expect("68719476736", "%lld", 0x1000000000LL);
    utest_expect("70000", "%ld", 70000);
    utest_expect("0xb0001234", "%p", (void*)0xb0001234);
    utest_expect("12ab", "%x", 0x12ab);
    utest_expect("12AB", "%X", 0x12ab);
    utest_expect("00123456", "%08x", 0x123456);
    utest_expect("01234", "0%d", 1234);
    utest_expect(" 1234", "%5d", 1234);
    utest_expect("01234", "%05d", 1234);
    utest_expect("    1234", "%8d", 1234);
    utest_expect("1234    ", "%-8d", 1234);
    utest_expect("abcdef     ", "%-11s", "abcdef");
    utest_expect("something:1234", "%s:%d", "something", 1234);
    utest_expect("005:5:05", "%03d:%d:%02d", 5, 5, 5);
    utest_expect("5,0x0", "%d,%p", 5, NULL);
    utest_expect("68719476736,6,7,8", "%lld,%d,%d,%d", 0x1000000000LL, 6, 7, 8);
    return gFails != 0;
}

#endif /* UNIT_TESTS */