diff options
Diffstat (limited to 'memisutf8.c')
| -rw-r--r-- | memisutf8.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/memisutf8.c b/memisutf8.c new file mode 100644 index 0000000..96a8b6b --- /dev/null +++ b/memisutf8.c @@ -0,0 +1,152 @@ +/* See LICENSE file for copyright and license details. */ +#include "libsimple.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; + + /* 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));\ + assert(libsimple_strisutf8(STRING, i) == (GOOD));\ + assert(libsimple_strnisutf8(STRING, sizeof(STRING) - 1, i) == (GOOD));\ + assert(libsimple_strnisutf8(STRING "\xFF", sizeof(STRING) - 1, i) == (GOOD));\ + assert(libsimple_strnisutf8(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 |