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/* See LICENSE file for copyright and license details. */
#include "common.h"
#ifndef TEST
int
libsimple_memisutf8(const char *string, size_t n, int allow_modified_nul)
{
static long BYTES_TO_MIN_BITS[] = {0, 0, 8, 12, 17, 22, 27};
static long BYTES_TO_MAX_BITS[] = {0, 7, 11, 16, 21, 26, 31};
long int bytes = 0, read_bytes = 0, bits = 0, c, character;
size_t i;
character = 0; /* silence false warning from compiler; `character` is set in `if (!read_bytes)` before `else` */
/* min bits max bits
0....... 0 7
110..... 10...... 8 11
1110.... 10...... 10...... 12 16
11110... 10...... 10...... 10...... 17 21
111110.. 10...... 10...... 10...... 10...... 22 26
1111110. 10...... 10...... 10...... 10...... 10...... 27 31
*/
for (i = 0; i < n; i++) {
c = (long int)string[i];
if (!read_bytes) {
/* First byte of the character. */
if (!(c & 0x80))
/* Single-byte character. */
continue;
if ((c & 0xC0) == 0x80)
/* Single-byte character marked as multibyte, or
a non-first byte in a multibyte character. */
return 0;
/* Multibyte character. */
while ((c & 0x80)) {
bytes++;
c <<= 1;
}
read_bytes = 1;
character = (c & 0xFF) >> bytes;
if (bytes > 6)
/* 31-bit characters can be encoded with 6-bytes,
and UTF-8 does not cover higher code points. */
return 0;
} else {
/* Not first byte of the character. */
if ((c & 0xC0) != 0x80)
/* Beginning of new character before a
multibyte character has ended. */
return 0;
character = (character << 6) | (c & 0x7F);
if (++read_bytes < bytes)
/* Not at last byte yet. */
continue;
/* Check that the character is not unnecessarily long. */
while (character) {
character >>= 1;
bits++;
}
bits = (!bits && bytes == 2 && allow_modified_nul) ? 8 : bits;
if (bits < BYTES_TO_MIN_BITS[bytes] || BYTES_TO_MAX_BITS[bytes] < bits)
return 0;
read_bytes = bytes = bits = 0;
}
}
/* Make sure we did not stop at the middle of a multibyte character. */
return !read_bytes;
}
#else
#include "test.h"
int
main(void)
{
#define ASSERT(STRING, GOOD)\
do {\
assert(libsimple_memisutf8(STRING, sizeof(STRING) - 1, i) == (GOOD));\
assert(libsimple_memisutf8(STRING "\xFF", sizeof(STRING) - 1, i) == (GOOD));\
assert(libsimple_memisutf8(STRING "\x00", sizeof(STRING) - 1, i) == (GOOD));\
} while (0)
int i;
for (i = 0; i < 2; i++) {
ASSERT("", 1);
ASSERT("a", 1);
ASSERT("abc", 1);
ASSERT("123", 1);
ASSERT("åäö", 1);
ASSERT("𝖆𝖇𝖈", 1);
ASSERT("\x1b", 1);
ASSERT("\n\r\t\f", 1);
ASSERT("\xFF", 0);
ASSERT("\x01", 1);
ASSERT("\x7F", 1);
ASSERT("\x80", 0);
ASSERT("\xC0", 0);
ASSERT("\xC0\x80", i);
ASSERT("\xC0\x81", 0);
ASSERT("\xCF", 0);
ASSERT("\xEF", 0);
ASSERT("\xEF\x8F", 0);
ASSERT("\xF7", 0);
ASSERT("\xF7\x8F", 0);
ASSERT("\xF7\x8F\x8F", 0);
ASSERT("\xFA", 0);
ASSERT("\xFA\x8F", 0);
ASSERT("\xFA\x8F\x8F", 0);
ASSERT("\xFA\x8F\x8F\x8F", 0);
ASSERT("\xFD", 0);
ASSERT("\xFD\x8F", 0);
ASSERT("\xFD\x8F\x8F", 0);
ASSERT("\xFD\x8F\x8F\x8F", 0);
ASSERT("\xFD\x8F\x8F\x8F\x8F", 0);
ASSERT("\xFE", 0);
ASSERT("\xFE\x8F", 0);
ASSERT("\xFE\x8F\x8F", 0);
ASSERT("\xFE\x8F\x8F\x8F", 0);
ASSERT("\xFE\x8F\x8F\x8F\x8F", 0);
ASSERT("\xFE\x8F\x8F\x8F\x8F\x8F", 0);
ASSERT("\xFF", 0);
ASSERT("\xFF\x8F", 0);
ASSERT("\xFF\x8F\x8F", 0);
ASSERT("\xFF\x8F\x8F\x8F", 0);
ASSERT("\xFF\x8F\x8F\x8F\x8F", 0);
ASSERT("\xFF\x8F\x8F\x8F\x8F\x8F", 0);
ASSERT("\xFF\x8F\x8F\x8F\x8F\x8F\x8F", 0);
ASSERT("\xC1\x80", 0);
ASSERT("\xC2\x80", 1);
ASSERT("\xE1\x80\x80\x80", 0);
ASSERT("\xE1\x80\xC0\x80", 0);
ASSERT("\xE1\x80\x00\x80", 0);
ASSERT("\xF1\x80\x80\x80", 1);
ASSERT("\xFF\x80\x80\x80\x80\x80\x80\x80", 0);
assert(libsimple_memisutf8("\0abc", sizeof("\0abc") - 1, i) == 1);
assert(libsimple_memisutf8("\0abc\x80", sizeof("\0abc\x80") - 1, i) == 0);
}
return 0;
}
#endif
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