Repository navigation
Expand file tree
/
Copy pathlibc.c
More file actions
432 lines (390 loc) · 12.6 KB
/
Copy pathlibc.c
File metadata and controls
432 lines (390 loc) · 12.6 KB
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
/* ----------------------------------------------------------------------------
Copyright (c) 2018-2024, Microsoft Research, Daan Leijen
This is free software; you can redistribute it and/or modify it under the
terms of the MIT license. A copy of the license can be found in the file
"LICENSE" at the root of this distribution.
-----------------------------------------------------------------------------*/
// --------------------------------------------------------
// This module defines various std libc functions to reduce
// the dependency on libc, and also prevent errors caused
// by some libc implementations when called before `main`
// executes (due to malloc redirection)
// --------------------------------------------------------
#include "mimalloc.h"
#include "mimalloc/internal.h"
#include "mimalloc/prim.h" // mi_prim_getenv
char _mi_toupper(char c) {
if (c >= 'a' && c <= 'z') return (c - 'a' + 'A');
else return c;
}
int _mi_strnicmp(const char* s, const char* t, size_t n) {
if (n == 0) return 0;
for (; *s != 0 && *t != 0 && n > 0; s++, t++, n--) {
if (_mi_toupper(*s) != _mi_toupper(*t)) break;
}
return (n == 0 ? 0 : *s - *t);
}
void _mi_strlcpy(char* dest, const char* src, size_t dest_size) {
if (dest==NULL || src==NULL || dest_size == 0) return;
// copy until end of src, or when dest is (almost) full
while (*src != 0 && dest_size > 1) {
*dest++ = *src++;
dest_size--;
}
// always zero terminate
*dest = 0;
}
void _mi_strlcat(char* dest, const char* src, size_t dest_size) {
if (dest==NULL || src==NULL || dest_size == 0) return;
// find end of string in the dest buffer
while (*dest != 0 && dest_size > 1) {
dest++;
dest_size--;
}
// and catenate
_mi_strlcpy(dest, src, dest_size);
}
size_t _mi_strlen(const char* s) {
if (s==NULL) return 0;
size_t len = 0;
while(s[len] != 0) { len++; }
return len;
}
size_t _mi_strnlen(const char* s, size_t max_len) {
if (s==NULL) return 0;
size_t len = 0;
while(s[len] != 0 && len < max_len) { len++; }
return len;
}
char* _mi_strnstr(char* s, size_t max_len, const char* pat) {
if (s==NULL) return NULL;
if (pat==NULL) return s;
const size_t m = _mi_strnlen(s, max_len);
const size_t n = _mi_strlen(pat);
for (size_t start = 0; start + n <= m; start++) {
size_t i = 0;
while (i<n && pat[i]==s[start+i]) {
i++;
}
if (i==n) return &s[start];
}
return NULL;
}
#ifdef MI_NO_GETENV
bool _mi_getenv(const char* name, char* result, size_t result_size) {
MI_UNUSED(name);
MI_UNUSED(result);
MI_UNUSED(result_size);
return false;
}
#else
bool _mi_getenv(const char* name, char* result, size_t result_size) {
if (name==NULL || result == NULL || result_size < 64) return false;
return _mi_prim_getenv(name,result,result_size);
}
#endif
// --------------------------------------------------------
// Define our own limited `_mi_vsnprintf` and `_mi_snprintf`
// This is mostly to avoid calling these when libc is not yet
// initialized (and to reduce dependencies)
//
// format: d i, p x u, s
// prec: z l ll L
// width: 10
// align-left: -
// fill: 0
// plus: +
// --------------------------------------------------------
static void mi_outc(char c, char** out, char* end) {
char* p = *out;
if (p >= end) return;
*p = c;
*out = p + 1;
}
static void mi_outs(const char* s, char** out, char* end) {
if (s == NULL) return;
char* p = *out;
while (*s != 0 && p < end) {
*p++ = *s++;
}
*out = p;
}
static void mi_out_fill(char fill, size_t len, char** out, char* end) {
char* p = *out;
for (size_t i = 0; i < len && p < end; i++) {
*p++ = fill;
}
*out = p;
}
static void mi_out_alignright(char fill, char* start, size_t len, size_t extra, char* end) {
if (len == 0 || extra == 0) return;
if (start + len + extra >= end) return;
// move `len` characters to the right (in reverse since it can overlap)
for (size_t i = 1; i <= len; i++) {
start[len + extra - i] = start[len - i];
}
// and fill the start
for (size_t i = 0; i < extra; i++) {
start[i] = fill;
}
}
static void mi_out_num(uintmax_t x, size_t base, char prefix, char** out, char* end)
{
if (x == 0 || base == 0 || base > 16) {
if (prefix != 0) { mi_outc(prefix, out, end); }
mi_outc('0',out,end);
}
else {
// output digits in reverse
char* start = *out;
while (x > 0) {
char digit = (char)(x % base);
mi_outc((digit <= 9 ? '0' + digit : 'A' + digit - 10),out,end);
x = x / base;
}
if (prefix != 0) {
mi_outc(prefix, out, end);
}
size_t len = *out - start;
// and reverse in-place
for (size_t i = 0; i < (len / 2); i++) {
char c = start[len - i - 1];
start[len - i - 1] = start[i];
start[i] = c;
}
}
}
#define MI_NEXTC() c = *in; if (c==0) break; in++;
int _mi_vsnprintf(char* buf, size_t bufsize, const char* fmt, va_list args) {
if (buf == NULL || bufsize == 0 || fmt == NULL) return 0;
buf[bufsize - 1] = 0;
char* const end = buf + (bufsize - 1);
const char* in = fmt;
char* out = buf;
while (true) {
if (out >= end) break;
char c;
MI_NEXTC();
if (c != '%') {
if (c == '\\') {
MI_NEXTC();
switch (c) {
case 'e': mi_outc('\x1B', &out, end); break;
case 't': mi_outc('\t', &out, end); break;
case 'n': mi_outc('\n', &out, end); break;
case 'r': mi_outc('\r', &out, end); break;
case '\\': mi_outc('\\', &out, end); break;
default: /* ignore */ break;
}
}
else if ((c >= ' ' && c <= '~') || c=='\n' || c=='\r' || c=='\t' || c=='\x1b') { // output visible ascii or standard control only
mi_outc(c, &out, end);
}
}
else {
MI_NEXTC();
char fill = ' ';
size_t width = 0;
char numtype = 'd';
char numplus = 0;
bool alignright = true;
if (c == '+' || c == ' ') { numplus = c; MI_NEXTC(); }
if (c == '-') { alignright = false; MI_NEXTC(); }
if (c == '0') { fill = '0'; MI_NEXTC(); }
if (c >= '1' && c <= '9') {
width = (c - '0'); MI_NEXTC();
while (c >= '0' && c <= '9') {
width = (10 * width) + (c - '0'); MI_NEXTC();
}
if (c == 0) break; // extra check due to while
}
if (c == 'z' || c == 't' || c == 'L') { numtype = c; MI_NEXTC(); }
else if (c == 'l') {
numtype = c; MI_NEXTC();
if (c == 'l') { numtype = 'L'; MI_NEXTC(); }
}
char* start = out;
if (c == '%') {
mi_outc('%', &out, end);
}
else if (c == 's') {
// string
const char* s = va_arg(args, const char*);
mi_outs(s, &out, end);
}
else if (c == 'p' || c == 'x' || c == 'u') {
// unsigned
uintmax_t x = 0;
if (c == 'x' || c == 'u') {
if (numtype == 'z') x = va_arg(args, size_t);
else if (numtype == 't') x = va_arg(args, uintptr_t); // unsigned ptrdiff_t
else if (numtype == 'L') x = va_arg(args, unsigned long long);
else if (numtype == 'l') x = va_arg(args, unsigned long);
else x = va_arg(args, unsigned int);
}
else if (c == 'p') {
x = va_arg(args, uintptr_t);
mi_outs("0x", &out, end);
start = out;
width = (width >= 2 ? width - 2 : 0);
}
if (width == 0 && (c == 'x' || c == 'p')) {
if (c == 'p') { width = 2 * (x <= UINT32_MAX ? 4 : ((x >> 16) <= UINT32_MAX ? 6 : sizeof(void*))); }
if (width == 0) { width = 2; }
fill = '0';
}
mi_out_num(x, (c == 'x' || c == 'p' ? 16 : 10), numplus, &out, end);
}
else if (c == 'i' || c == 'd') {
// signed
intmax_t x = 0;
if (numtype == 'z') x = va_arg(args, intptr_t );
else if (numtype == 't') x = va_arg(args, ptrdiff_t);
else if (numtype == 'L') x = va_arg(args, long long);
else if (numtype == 'l') x = va_arg(args, long);
else x = va_arg(args, int);
char pre = 0;
if (x < 0) {
pre = '-';
if (x > INTMAX_MIN) { x = -x; }
}
else if (numplus != 0) {
pre = numplus;
}
mi_out_num((uintmax_t)x, 10, pre, &out, end);
}
else if (c >= ' ' && c <= '~') {
// unknown format
mi_outc('%', &out, end);
mi_outc(c, &out, end);
}
// fill & align
mi_assert_internal(out <= end);
mi_assert_internal(out >= start);
const size_t len = out - start;
if (len < width) {
mi_out_fill(fill, width - len, &out, end);
if (alignright && out <= end) {
mi_out_alignright(fill, start, len, width - len, end);
}
}
}
}
mi_assert_internal(out <= end);
*out = 0;
return (int)(out - buf);
}
int _mi_snprintf(char* buf, size_t buflen, const char* fmt, ...) {
va_list args;
va_start(args, fmt);
const int written = _mi_vsnprintf(buf, buflen, fmt, args);
va_end(args);
return written;
}
// --------------------------------------------------------
// generic trailing and leading zero count, and popcount
// --------------------------------------------------------
#if !MI_HAS_FAST_BITSCAN
static size_t mi_ctz_generic32(uint32_t x) {
// de Bruijn multiplication, see <http://keithandkatie.com/keith/papers/debruijn.html>
static const uint8_t debruijn[32] = {
0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
};
if (x==0) return 32;
return debruijn[(uint32_t)((x & -(int32_t)x) * (uint32_t)(0x077CB531U)) >> 27];
}
static size_t mi_clz_generic32(uint32_t x) {
// de Bruijn multiplication, see <http://keithandkatie.com/keith/papers/debruijn.html>
static const uint8_t debruijn[32] = {
31, 22, 30, 21, 18, 10, 29, 2, 20, 17, 15, 13, 9, 6, 28, 1,
23, 19, 11, 3, 16, 14, 7, 24, 12, 4, 8, 25, 5, 26, 27, 0
};
if (x==0) return 32;
x |= x >> 1;
x |= x >> 2;
x |= x >> 4;
x |= x >> 8;
x |= x >> 16;
return debruijn[(uint32_t)(x * (uint32_t)(0x07C4ACDDU)) >> 27];
}
size_t _mi_ctz_generic(size_t x) {
if (x==0) return MI_SIZE_BITS;
#if (MI_SIZE_BITS <= 32)
return mi_ctz_generic32((uint32_t)x);
#else
const uint32_t lo = (uint32_t)x;
if (lo != 0) {
return mi_ctz_generic32(lo);
}
else {
return (32 + mi_ctz_generic32((uint32_t)(x>>32)));
}
#endif
}
size_t _mi_clz_generic(size_t x) {
if (x==0) return MI_SIZE_BITS;
#if (MI_SIZE_BITS <= 32)
return mi_clz_generic32((uint32_t)x);
#else
const uint32_t hi = (uint32_t)(x>>32);
if (hi != 0) {
return mi_clz_generic32(hi);
}
else {
return 32 + mi_clz_generic32((uint32_t)x);
}
#endif
}
#endif // bit scan
#if MI_SIZE_SIZE == 4
#define mi_mask_even_bits32 (0x55555555)
#define mi_mask_even_pairs32 (0x33333333)
#define mi_mask_even_nibbles32 (0x0F0F0F0F)
// sum of all the bytes in `x` if it is guaranteed that the sum < 256!
static size_t mi_byte_sum32(uint32_t x) {
// perform `x * 0x01010101`: the highest byte contains the sum of all bytes.
x += (x << 8);
x += (x << 16);
return (size_t)(x >> 24);
}
static size_t mi_popcount_generic32(uint32_t x) {
// first count each 2-bit group `a`, where: a==0b00 -> 00, a==0b01 -> 01, a==0b10 -> 01, a==0b11 -> 10
// in other words, `a - (a>>1)`; to do this in parallel, we need to mask to prevent spilling a bit pair
// into the lower bit-pair:
x = x - ((x >> 1) & mi_mask_even_bits32);
// add the 2-bit pair results
x = (x & mi_mask_even_pairs32) + ((x >> 2) & mi_mask_even_pairs32);
// add the 4-bit nibble results
x = (x + (x >> 4)) & mi_mask_even_nibbles32;
// each byte now has a count of its bits, we can sum them now:
return mi_byte_sum32(x);
}
mi_decl_noinline size_t _mi_popcount_generic(size_t x) {
if (x<=1) return x;
if (~x==0) return MI_SIZE_BITS;
return mi_popcount_generic32(x);
}
#else
#define mi_mask_even_bits64 (0x5555555555555555)
#define mi_mask_even_pairs64 (0x3333333333333333)
#define mi_mask_even_nibbles64 (0x0F0F0F0F0F0F0F0F)
// sum of all the bytes in `x` if it is guaranteed that the sum < 256!
static size_t mi_byte_sum64(uint64_t x) {
x += (x << 8);
x += (x << 16);
x += (x << 32);
return (size_t)(x >> 56);
}
static size_t mi_popcount_generic64(uint64_t x) {
x = x - ((x >> 1) & mi_mask_even_bits64);
x = (x & mi_mask_even_pairs64) + ((x >> 2) & mi_mask_even_pairs64);
x = (x + (x >> 4)) & mi_mask_even_nibbles64;
return mi_byte_sum64(x);
}
mi_decl_noinline size_t _mi_popcount_generic(size_t x) {
if (x<=1) return x;
if (~x==0) return MI_SIZE_BITS;
return mi_popcount_generic64(x);
}
#endif