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1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
2/*
3 * string function definitions for NOLIBC
4 * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
5 */
6
7#ifndef _NOLIBC_STRING_H
8#define _NOLIBC_STRING_H
9
10#include "std.h"
11
12static void *malloc(size_t len);
13
14/*
15 * As much as possible, please keep functions alphabetically sorted.
16 */
17
18static __attribute__((unused))
19int memcmp(const void *s1, const void *s2, size_t n)
20{
21 size_t ofs = 0;
22 int c1 = 0;
23
24 while (ofs < n && !(c1 = ((unsigned char *)s1)[ofs] - ((unsigned char *)s2)[ofs])) {
25 ofs++;
26 }
27 return c1;
28}
29
30static __attribute__((unused))
31void *_nolibc_memcpy_up(void *dst, const void *src, size_t len)
32{
33 size_t pos = 0;
34
35 while (pos < len) {
36 ((char *)dst)[pos] = ((const char *)src)[pos];
37 pos++;
38 }
39 return dst;
40}
41
42static __attribute__((unused))
43void *_nolibc_memcpy_down(void *dst, const void *src, size_t len)
44{
45 while (len) {
46 len--;
47 ((char *)dst)[len] = ((const char *)src)[len];
48 }
49 return dst;
50}
51
52/* might be ignored by the compiler without -ffreestanding, then found as
53 * missing.
54 */
55__attribute__((weak,unused,section(".text.nolibc_memmove")))
56void *memmove(void *dst, const void *src, size_t len)
57{
58 size_t dir, pos;
59
60 pos = len;
61 dir = -1;
62
63 if (dst < src) {
64 pos = -1;
65 dir = 1;
66 }
67
68 while (len) {
69 pos += dir;
70 ((char *)dst)[pos] = ((const char *)src)[pos];
71 len--;
72 }
73 return dst;
74}
75
76/* must be exported, as it's used by libgcc on ARM */
77__attribute__((weak,unused,section(".text.nolibc_memcpy")))
78void *memcpy(void *dst, const void *src, size_t len)
79{
80 return _nolibc_memcpy_up(dst, src, len);
81}
82
83/* might be ignored by the compiler without -ffreestanding, then found as
84 * missing.
85 */
86__attribute__((weak,unused,section(".text.nolibc_memset")))
87void *memset(void *dst, int b, size_t len)
88{
89 char *p = dst;
90
91 while (len--) {
92 /* prevent gcc from recognizing memset() here */
93 asm volatile("");
94 *(p++) = b;
95 }
96 return dst;
97}
98
99static __attribute__((unused))
100char *strchr(const char *s, int c)
101{
102 while (*s) {
103 if (*s == (char)c)
104 return (char *)s;
105 s++;
106 }
107 return NULL;
108}
109
110static __attribute__((unused))
111int strcmp(const char *a, const char *b)
112{
113 unsigned int c;
114 int diff;
115
116 while (!(diff = (unsigned char)*a++ - (c = (unsigned char)*b++)) && c)
117 ;
118 return diff;
119}
120
121static __attribute__((unused))
122char *strcpy(char *dst, const char *src)
123{
124 char *ret = dst;
125
126 while ((*dst++ = *src++));
127 return ret;
128}
129
130/* this function is only used with arguments that are not constants or when
131 * it's not known because optimizations are disabled. Note that gcc 12
132 * recognizes an strlen() pattern and replaces it with a jump to strlen(),
133 * thus itself, hence the asm() statement below that's meant to disable this
134 * confusing practice.
135 */
136static __attribute__((unused))
137size_t strlen(const char *str)
138{
139 size_t len;
140
141 for (len = 0; str[len]; len++)
142 asm("");
143 return len;
144}
145
146/* do not trust __builtin_constant_p() at -O0, as clang will emit a test and
147 * the two branches, then will rely on an external definition of strlen().
148 */
149#if defined(__OPTIMIZE__)
150#define nolibc_strlen(x) strlen(x)
151#define strlen(str) ({ \
152 __builtin_constant_p((str)) ? \
153 __builtin_strlen((str)) : \
154 nolibc_strlen((str)); \
155})
156#endif
157
158static __attribute__((unused))
159size_t strnlen(const char *str, size_t maxlen)
160{
161 size_t len;
162
163 for (len = 0; (len < maxlen) && str[len]; len++);
164 return len;
165}
166
167static __attribute__((unused))
168char *strdup(const char *str)
169{
170 size_t len;
171 char *ret;
172
173 len = strlen(str);
174 ret = malloc(len + 1);
175 if (__builtin_expect(ret != NULL, 1))
176 memcpy(ret, str, len + 1);
177
178 return ret;
179}
180
181static __attribute__((unused))
182char *strndup(const char *str, size_t maxlen)
183{
184 size_t len;
185 char *ret;
186
187 len = strnlen(str, maxlen);
188 ret = malloc(len + 1);
189 if (__builtin_expect(ret != NULL, 1)) {
190 memcpy(ret, str, len);
191 ret[len] = '\0';
192 }
193
194 return ret;
195}
196
197static __attribute__((unused))
198size_t strlcat(char *dst, const char *src, size_t size)
199{
200 size_t len;
201 char c;
202
203 for (len = 0; dst[len]; len++)
204 ;
205
206 for (;;) {
207 c = *src;
208 if (len < size)
209 dst[len] = c;
210 if (!c)
211 break;
212 len++;
213 src++;
214 }
215
216 return len;
217}
218
219static __attribute__((unused))
220size_t strlcpy(char *dst, const char *src, size_t size)
221{
222 size_t len;
223 char c;
224
225 for (len = 0;;) {
226 c = src[len];
227 if (len < size)
228 dst[len] = c;
229 if (!c)
230 break;
231 len++;
232 }
233 return len;
234}
235
236static __attribute__((unused))
237char *strncat(char *dst, const char *src, size_t size)
238{
239 char *orig = dst;
240
241 while (*dst)
242 dst++;
243
244 while (size && (*dst = *src)) {
245 src++;
246 dst++;
247 size--;
248 }
249
250 *dst = 0;
251 return orig;
252}
253
254static __attribute__((unused))
255int strncmp(const char *a, const char *b, size_t size)
256{
257 unsigned int c;
258 int diff = 0;
259
260 while (size-- &&
261 !(diff = (unsigned char)*a++ - (c = (unsigned char)*b++)) && c)
262 ;
263
264 return diff;
265}
266
267static __attribute__((unused))
268char *strncpy(char *dst, const char *src, size_t size)
269{
270 size_t len;
271
272 for (len = 0; len < size; len++)
273 if ((dst[len] = *src))
274 src++;
275 return dst;
276}
277
278static __attribute__((unused))
279char *strrchr(const char *s, int c)
280{
281 const char *ret = NULL;
282
283 while (*s) {
284 if (*s == (char)c)
285 ret = s;
286 s++;
287 }
288 return (char *)ret;
289}
290
291/* make sure to include all global symbols */
292#include "nolibc.h"
293
294#endif /* _NOLIBC_STRING_H */
1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
2/*
3 * string function definitions for NOLIBC
4 * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
5 */
6
7#ifndef _NOLIBC_STRING_H
8#define _NOLIBC_STRING_H
9
10#include "arch.h"
11#include "std.h"
12
13static void *malloc(size_t len);
14
15/*
16 * As much as possible, please keep functions alphabetically sorted.
17 */
18
19static __attribute__((unused))
20int memcmp(const void *s1, const void *s2, size_t n)
21{
22 size_t ofs = 0;
23 int c1 = 0;
24
25 while (ofs < n && !(c1 = ((unsigned char *)s1)[ofs] - ((unsigned char *)s2)[ofs])) {
26 ofs++;
27 }
28 return c1;
29}
30
31#ifndef NOLIBC_ARCH_HAS_MEMMOVE
32/* might be ignored by the compiler without -ffreestanding, then found as
33 * missing.
34 */
35__attribute__((weak,unused,section(".text.nolibc_memmove")))
36void *memmove(void *dst, const void *src, size_t len)
37{
38 size_t dir, pos;
39
40 pos = len;
41 dir = -1;
42
43 if (dst < src) {
44 pos = -1;
45 dir = 1;
46 }
47
48 while (len) {
49 pos += dir;
50 ((char *)dst)[pos] = ((const char *)src)[pos];
51 len--;
52 }
53 return dst;
54}
55#endif /* #ifndef NOLIBC_ARCH_HAS_MEMMOVE */
56
57#ifndef NOLIBC_ARCH_HAS_MEMCPY
58/* must be exported, as it's used by libgcc on ARM */
59__attribute__((weak,unused,section(".text.nolibc_memcpy")))
60void *memcpy(void *dst, const void *src, size_t len)
61{
62 size_t pos = 0;
63
64 while (pos < len) {
65 ((char *)dst)[pos] = ((const char *)src)[pos];
66 pos++;
67 }
68 return dst;
69}
70#endif /* #ifndef NOLIBC_ARCH_HAS_MEMCPY */
71
72#ifndef NOLIBC_ARCH_HAS_MEMSET
73/* might be ignored by the compiler without -ffreestanding, then found as
74 * missing.
75 */
76__attribute__((weak,unused,section(".text.nolibc_memset")))
77void *memset(void *dst, int b, size_t len)
78{
79 char *p = dst;
80
81 while (len--) {
82 /* prevent gcc from recognizing memset() here */
83 __asm__ volatile("");
84 *(p++) = b;
85 }
86 return dst;
87}
88#endif /* #ifndef NOLIBC_ARCH_HAS_MEMSET */
89
90static __attribute__((unused))
91char *strchr(const char *s, int c)
92{
93 while (*s) {
94 if (*s == (char)c)
95 return (char *)s;
96 s++;
97 }
98 return NULL;
99}
100
101static __attribute__((unused))
102int strcmp(const char *a, const char *b)
103{
104 unsigned int c;
105 int diff;
106
107 while (!(diff = (unsigned char)*a++ - (c = (unsigned char)*b++)) && c)
108 ;
109 return diff;
110}
111
112static __attribute__((unused))
113char *strcpy(char *dst, const char *src)
114{
115 char *ret = dst;
116
117 while ((*dst++ = *src++));
118 return ret;
119}
120
121/* this function is only used with arguments that are not constants or when
122 * it's not known because optimizations are disabled. Note that gcc 12
123 * recognizes an strlen() pattern and replaces it with a jump to strlen(),
124 * thus itself, hence the asm() statement below that's meant to disable this
125 * confusing practice.
126 */
127__attribute__((weak,unused,section(".text.nolibc_strlen")))
128size_t strlen(const char *str)
129{
130 size_t len;
131
132 for (len = 0; str[len]; len++)
133 __asm__("");
134 return len;
135}
136
137/* do not trust __builtin_constant_p() at -O0, as clang will emit a test and
138 * the two branches, then will rely on an external definition of strlen().
139 */
140#if defined(__OPTIMIZE__)
141#define nolibc_strlen(x) strlen(x)
142#define strlen(str) ({ \
143 __builtin_constant_p((str)) ? \
144 __builtin_strlen((str)) : \
145 nolibc_strlen((str)); \
146})
147#endif
148
149static __attribute__((unused))
150size_t strnlen(const char *str, size_t maxlen)
151{
152 size_t len;
153
154 for (len = 0; (len < maxlen) && str[len]; len++);
155 return len;
156}
157
158static __attribute__((unused))
159char *strdup(const char *str)
160{
161 size_t len;
162 char *ret;
163
164 len = strlen(str);
165 ret = malloc(len + 1);
166 if (__builtin_expect(ret != NULL, 1))
167 memcpy(ret, str, len + 1);
168
169 return ret;
170}
171
172static __attribute__((unused))
173char *strndup(const char *str, size_t maxlen)
174{
175 size_t len;
176 char *ret;
177
178 len = strnlen(str, maxlen);
179 ret = malloc(len + 1);
180 if (__builtin_expect(ret != NULL, 1)) {
181 memcpy(ret, str, len);
182 ret[len] = '\0';
183 }
184
185 return ret;
186}
187
188static __attribute__((unused))
189size_t strlcat(char *dst, const char *src, size_t size)
190{
191 size_t len = strnlen(dst, size);
192
193 /*
194 * We want len < size-1. But as size is unsigned and can wrap
195 * around, we use len + 1 instead.
196 */
197 while (len + 1 < size) {
198 dst[len] = *src;
199 if (*src == '\0')
200 break;
201 len++;
202 src++;
203 }
204
205 if (len < size)
206 dst[len] = '\0';
207
208 while (*src++)
209 len++;
210
211 return len;
212}
213
214static __attribute__((unused))
215size_t strlcpy(char *dst, const char *src, size_t size)
216{
217 size_t len;
218
219 for (len = 0; len < size; len++) {
220 dst[len] = src[len];
221 if (!dst[len])
222 return len;
223 }
224 if (size)
225 dst[size-1] = '\0';
226
227 while (src[len])
228 len++;
229
230 return len;
231}
232
233static __attribute__((unused))
234char *strncat(char *dst, const char *src, size_t size)
235{
236 char *orig = dst;
237
238 while (*dst)
239 dst++;
240
241 while (size && (*dst = *src)) {
242 src++;
243 dst++;
244 size--;
245 }
246
247 *dst = 0;
248 return orig;
249}
250
251static __attribute__((unused))
252int strncmp(const char *a, const char *b, size_t size)
253{
254 unsigned int c;
255 int diff = 0;
256
257 while (size-- &&
258 !(diff = (unsigned char)*a++ - (c = (unsigned char)*b++)) && c)
259 ;
260
261 return diff;
262}
263
264static __attribute__((unused))
265char *strncpy(char *dst, const char *src, size_t size)
266{
267 size_t len;
268
269 for (len = 0; len < size; len++)
270 if ((dst[len] = *src))
271 src++;
272 return dst;
273}
274
275static __attribute__((unused))
276char *strrchr(const char *s, int c)
277{
278 const char *ret = NULL;
279
280 while (*s) {
281 if (*s == (char)c)
282 ret = s;
283 s++;
284 }
285 return (char *)ret;
286}
287
288/* make sure to include all global symbols */
289#include "nolibc.h"
290
291#endif /* _NOLIBC_STRING_H */