785 lines
19 KiB
C
785 lines
19 KiB
C
/*
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Basic UTF-8 manipulation routines
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by Jeff Bezanson
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placed in the public domain Fall 2005
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This code is designed to provide the utilities you need to manipulate
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UTF-8 as an internal string encoding. These functions do not perform the
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error checking normally needed when handling UTF-8 data, so if you happen
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to be from the Unicode Consortium you will want to flay me alive.
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I do this because error checking can be performed at the boundaries (I/O),
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with these routines reserved for higher performance on data known to be
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valid.
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A UTF-8 validation routine is included.
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*/
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#include <assert.h>
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#include <math.h>
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#include <setjmp.h>
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#include <stdarg.h>
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#include <stddef.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <wchar.h>
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#include <wctype.h>
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#ifdef _WIN32
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#include <malloc.h>
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#define snprintf _snprintf
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#endif
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#include "scheme.h"
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static const uint32_t offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL,
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0x000E2080UL, 0x03C82080UL,
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0xFA082080UL, 0x82082080UL };
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static const char trailingBytesForUTF8[256] = {
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
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1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
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1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
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3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5
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};
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/* returns length of next utf-8 sequence */
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size_t u8_seqlen(const char *s)
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{
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return trailingBytesForUTF8[(unsigned int)(unsigned char)s[0]] + 1;
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}
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/* returns the # of bytes needed to encode a certain character
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0 means the character cannot (or should not) be encoded. */
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size_t u8_charlen(uint32_t ch)
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{
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if (ch < 0x80)
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return 1;
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else if (ch < 0x800)
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return 2;
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else if (ch < 0x10000)
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return 3;
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else if (ch < 0x110000)
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return 4;
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return 0;
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}
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size_t u8_codingsize(uint32_t *wcstr, size_t n)
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{
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size_t i, c = 0;
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for (i = 0; i < n; i++)
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c += u8_charlen(wcstr[i]);
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return c;
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}
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/* conversions without error checking
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only works for valid UTF-8, i.e. no 5- or 6-byte sequences
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srcsz = source size in bytes
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sz = dest size in # of wide characters
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returns # characters converted
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if sz == srcsz+1 (i.e. 4*srcsz+4 bytes), there will always be enough space.
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*/
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size_t u8_toucs(uint32_t *dest, size_t sz, const char *src, size_t srcsz)
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{
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uint32_t ch;
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const char *src_end = src + srcsz;
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size_t nb;
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size_t i = 0;
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if (sz == 0 || srcsz == 0)
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return 0;
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while (i < sz) {
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if (!isutf(*src)) { // invalid sequence
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dest[i++] = 0xFFFD;
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src++;
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if (src >= src_end)
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break;
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continue;
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}
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nb = trailingBytesForUTF8[(unsigned char)*src];
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if (src + nb >= src_end)
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break;
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ch = 0;
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switch (nb) {
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case 5:
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ch += (unsigned char)*src++;
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ch <<= 6;
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// fallthrough
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case 4:
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ch += (unsigned char)*src++;
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ch <<= 6;
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// fallthrough
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case 3:
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ch += (unsigned char)*src++;
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ch <<= 6;
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// fallthrough
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case 2:
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ch += (unsigned char)*src++;
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ch <<= 6;
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// fallthrough
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case 1:
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ch += (unsigned char)*src++;
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ch <<= 6;
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// fallthrough
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case 0:
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ch += (unsigned char)*src++;
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}
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ch -= offsetsFromUTF8[nb];
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dest[i++] = ch;
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}
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return i;
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}
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/* srcsz = number of source characters
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sz = size of dest buffer in bytes
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returns # bytes stored in dest
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the destination string will never be bigger than the source string.
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*/
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size_t u8_toutf8(char *dest, size_t sz, const uint32_t *src, size_t srcsz)
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{
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uint32_t ch;
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size_t i = 0;
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char *dest0 = dest;
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char *dest_end = dest + sz;
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while (i < srcsz) {
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ch = src[i];
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if (ch < 0x80) {
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if (dest >= dest_end)
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break;
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*dest++ = (char)ch;
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} else if (ch < 0x800) {
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if (dest >= dest_end - 1)
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break;
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*dest++ = (ch >> 6) | 0xC0;
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*dest++ = (ch & 0x3F) | 0x80;
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} else if (ch < 0x10000) {
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if (dest >= dest_end - 2)
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break;
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*dest++ = (ch >> 12) | 0xE0;
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*dest++ = ((ch >> 6) & 0x3F) | 0x80;
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*dest++ = (ch & 0x3F) | 0x80;
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} else if (ch < 0x110000) {
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if (dest >= dest_end - 3)
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break;
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*dest++ = (ch >> 18) | 0xF0;
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*dest++ = ((ch >> 12) & 0x3F) | 0x80;
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*dest++ = ((ch >> 6) & 0x3F) | 0x80;
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*dest++ = (ch & 0x3F) | 0x80;
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}
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i++;
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}
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return (dest - dest0);
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}
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size_t u8_wc_toutf8(char *dest, uint32_t ch)
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{
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if (ch < 0x80) {
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dest[0] = (char)ch;
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return 1;
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}
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if (ch < 0x800) {
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dest[0] = (ch >> 6) | 0xC0;
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dest[1] = (ch & 0x3F) | 0x80;
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return 2;
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}
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if (ch < 0x10000) {
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dest[0] = (ch >> 12) | 0xE0;
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dest[1] = ((ch >> 6) & 0x3F) | 0x80;
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dest[2] = (ch & 0x3F) | 0x80;
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return 3;
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}
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if (ch < 0x110000) {
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dest[0] = (ch >> 18) | 0xF0;
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dest[1] = ((ch >> 12) & 0x3F) | 0x80;
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dest[2] = ((ch >> 6) & 0x3F) | 0x80;
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dest[3] = (ch & 0x3F) | 0x80;
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return 4;
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}
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return 0;
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}
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/* charnum => byte offset */
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size_t u8_offset(const char *s, size_t charnum)
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{
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size_t i = 0;
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while (charnum > 0) {
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if (s[i++] & 0x80) {
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(void)(isutf(s[++i]) || isutf(s[++i]) || ++i);
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}
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charnum--;
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}
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return i;
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}
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/* byte offset => charnum */
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size_t u8_charnum(const char *s, size_t offset)
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{
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size_t charnum = 0, i = 0;
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while (i < offset) {
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if (s[i++] & 0x80) {
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(void)(isutf(s[++i]) || isutf(s[++i]) || ++i);
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}
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charnum++;
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}
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return charnum;
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}
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/* number of characters in NUL-terminated string */
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size_t u8_strlen(const char *s)
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{
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size_t count = 0;
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size_t i = 0, lasti;
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while (1) {
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lasti = i;
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while (s[i] > 0)
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i++;
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count += (i - lasti);
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if (s[i++] == 0)
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break;
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(void)(isutf(s[++i]) || isutf(s[++i]) || ++i);
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count++;
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}
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return count;
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}
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#ifdef _WIN32
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#include "wcwidth.h"
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#endif
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size_t u8_strwidth(const char *s)
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{
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uint32_t ch;
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size_t nb, tot = 0;
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int w;
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signed char sc;
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while ((sc = (signed char)*s) != 0) {
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if (sc >= 0) {
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s++;
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if (sc)
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tot++;
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} else {
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if (!isutf(sc)) {
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tot++;
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s++;
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continue;
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}
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nb = trailingBytesForUTF8[(unsigned char)sc];
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ch = 0;
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switch (nb) {
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case 5:
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ch += (unsigned char)*s++;
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ch <<= 6;
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// fallthrough
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case 4:
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ch += (unsigned char)*s++;
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ch <<= 6;
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// fallthrough
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case 3:
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ch += (unsigned char)*s++;
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ch <<= 6;
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// fallthrough
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case 2:
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ch += (unsigned char)*s++;
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ch <<= 6;
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// fallthrough
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case 1:
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ch += (unsigned char)*s++;
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ch <<= 6;
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// fallthrough
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case 0:
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ch += (unsigned char)*s++;
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}
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ch -= offsetsFromUTF8[nb];
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w = wcwidth(ch); // might return -1
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if (w > 0)
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tot += w;
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}
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}
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return tot;
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}
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/* reads the next utf-8 sequence out of a string, updating an index */
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uint32_t u8_nextchar(const char *s, size_t *i)
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{
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uint32_t ch = 0;
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size_t sz = 0;
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do {
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ch <<= 6;
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ch += (unsigned char)s[(*i)];
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sz++;
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} while (s[*i] && (++(*i)) && !isutf(s[*i]));
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ch -= offsetsFromUTF8[sz - 1];
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return ch;
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}
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/* next character without NUL character terminator */
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uint32_t u8_nextmemchar(const char *s, size_t *i)
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{
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uint32_t ch = 0;
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size_t sz = 0;
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do {
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ch <<= 6;
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ch += (unsigned char)s[(*i)++];
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sz++;
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} while (!isutf(s[*i]));
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ch -= offsetsFromUTF8[sz - 1];
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return ch;
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}
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void u8_inc(const char *s, size_t *i)
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{
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(void)(isutf(s[++(*i)]) || isutf(s[++(*i)]) || isutf(s[++(*i)]) ||
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++(*i));
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}
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void u8_dec(const char *s, size_t *i)
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{
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(void)(isutf(s[--(*i)]) || isutf(s[--(*i)]) || isutf(s[--(*i)]) ||
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--(*i));
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}
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int octal_digit(char c) { return (c >= '0' && c <= '7'); }
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int hex_digit(char c)
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{
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return ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F') ||
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(c >= 'a' && c <= 'f'));
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}
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char read_escape_control_char(char c)
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{
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if (c == 'n')
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return '\n';
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else if (c == 't')
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return '\t';
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else if (c == 'r')
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return '\r';
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else if (c == 'e')
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return '\e';
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else if (c == 'b')
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return '\b';
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else if (c == 'f')
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return '\f';
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else if (c == 'v')
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return '\v';
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else if (c == 'a')
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return '\a';
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return c;
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}
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/* assumes that src points to the character after a backslash
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returns number of input characters processed, 0 if error */
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size_t u8_read_escape_sequence(const char *str, size_t ssz, uint32_t *dest)
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{
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uint32_t ch;
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char digs[10];
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int dno, ndig;
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size_t i;
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char c0;
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assert(ssz > 0);
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dno = 0;
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i = 1;
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c0 = str[0];
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if (octal_digit(c0)) {
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i = 0;
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do {
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digs[dno++] = str[i++];
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} while (i < ssz && octal_digit(str[i]) && dno < 3);
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digs[dno] = '\0';
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ch = strtol(digs, NULL, 8);
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*dest = ch;
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return i;
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}
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if (c0 == 'x') {
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ndig = 2;
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} else if (c0 == 'u') {
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ndig = 4;
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} else if (c0 == 'U') {
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ndig = 8;
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} else {
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ndig = 0;
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}
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if (ndig) {
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while (i < ssz && hex_digit(str[i]) && dno < ndig) {
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digs[dno++] = str[i++];
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}
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if (dno == 0)
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return 0;
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digs[dno] = '\0';
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ch = strtol(digs, NULL, 16);
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} else {
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ch = (uint32_t)read_escape_control_char(c0);
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}
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*dest = ch;
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return i;
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}
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/* convert a string with literal \uxxxx or \Uxxxxxxxx characters to UTF-8
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example: u8_unescape(mybuf, 256, "hello\\u220e")
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note the double backslash is needed if called on a C string literal */
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size_t u8_unescape(char *buf, size_t sz, const char *src)
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{
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size_t c = 0, amt;
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uint32_t ch;
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char temp[4];
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while (*src && c < sz) {
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if (*src == '\\') {
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src++;
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amt = u8_read_escape_sequence(src, 1000, &ch);
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} else {
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ch = (uint32_t)*src;
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amt = 1;
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}
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src += amt;
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amt = u8_wc_toutf8(temp, ch);
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if (amt > sz - c)
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break;
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memcpy(&buf[c], temp, amt);
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c += amt;
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}
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if (c < sz)
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buf[c] = '\0';
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return c;
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}
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static int buf_put2c(char *buf, const char *src)
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{
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buf[0] = src[0];
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buf[1] = src[1];
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buf[2] = '\0';
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return 2;
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}
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int u8_escape_wchar(char *buf, size_t sz, uint32_t ch)
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{
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assert(sz > 2);
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if (ch == L'\n')
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return buf_put2c(buf, "\\n");
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else if (ch == L'\t')
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return buf_put2c(buf, "\\t");
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else if (ch == L'\r')
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return buf_put2c(buf, "\\r");
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else if (ch == L'\e')
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return buf_put2c(buf, "\\e");
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else if (ch == L'\b')
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return buf_put2c(buf, "\\b");
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else if (ch == L'\f')
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return buf_put2c(buf, "\\f");
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else if (ch == L'\v')
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return buf_put2c(buf, "\\v");
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else if (ch == L'\a')
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return buf_put2c(buf, "\\a");
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else if (ch == L'\\')
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return buf_put2c(buf, "\\\\");
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else if (ch < 32 || ch == 0x7f)
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return snprintf(buf, sz, "\\x%.2hhx", (unsigned char)ch);
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else if (ch > 0xFFFF)
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return snprintf(buf, sz, "\\U%.8x", (uint32_t)ch);
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else if (ch >= 0x80)
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return snprintf(buf, sz, "\\u%.4hx", (unsigned short)ch);
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buf[0] = (char)ch;
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buf[1] = '\0';
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return 1;
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}
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size_t u8_escape(char *buf, size_t sz, const char *src, size_t *pi,
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size_t end, int escape_quotes, int ascii)
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{
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size_t i = *pi, i0;
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uint32_t ch;
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char *start = buf;
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char *blim = start + sz - 11;
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assert(sz > 11);
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while (i < end && buf < blim) {
|
|
// sz-11: leaves room for longest escape sequence
|
|
if (escape_quotes && src[i] == '"') {
|
|
buf += buf_put2c(buf, "\\\"");
|
|
i++;
|
|
} else if (src[i] == '\\') {
|
|
buf += buf_put2c(buf, "\\\\");
|
|
i++;
|
|
} else {
|
|
i0 = i;
|
|
ch = u8_nextmemchar(src, &i);
|
|
if (ascii || !iswprint((wint_t)ch)) {
|
|
buf += u8_escape_wchar(buf, sz - (buf - start), ch);
|
|
} else {
|
|
i = i0;
|
|
do {
|
|
*buf++ = src[i++];
|
|
} while (!isutf(src[i]));
|
|
}
|
|
}
|
|
}
|
|
*buf++ = '\0';
|
|
*pi = i;
|
|
return (buf - start);
|
|
}
|
|
|
|
char *u8_strchr(const char *s, uint32_t ch, size_t *charn)
|
|
{
|
|
size_t i = 0, lasti = 0;
|
|
uint32_t c;
|
|
|
|
*charn = 0;
|
|
while (s[i]) {
|
|
c = u8_nextchar(s, &i);
|
|
if (c == ch) {
|
|
/* it's const for us, but not necessarily the caller */
|
|
return (char *)&s[lasti];
|
|
}
|
|
lasti = i;
|
|
(*charn)++;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
char *u8_memchr(const char *s, uint32_t ch, size_t sz, size_t *charn)
|
|
{
|
|
size_t i = 0, lasti = 0;
|
|
uint32_t c;
|
|
int csz;
|
|
|
|
*charn = 0;
|
|
while (i < sz) {
|
|
c = csz = 0;
|
|
do {
|
|
c <<= 6;
|
|
c += (unsigned char)s[i++];
|
|
csz++;
|
|
} while (i < sz && !isutf(s[i]));
|
|
c -= offsetsFromUTF8[csz - 1];
|
|
|
|
if (c == ch) {
|
|
return (char *)&s[lasti];
|
|
}
|
|
lasti = i;
|
|
(*charn)++;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
char *u8_memrchr(const char *s, uint32_t ch, size_t sz)
|
|
{
|
|
size_t i = sz - 1, tempi = 0;
|
|
uint32_t c;
|
|
|
|
if (sz == 0)
|
|
return NULL;
|
|
|
|
while (i && !isutf(s[i]))
|
|
i--;
|
|
|
|
while (1) {
|
|
tempi = i;
|
|
c = u8_nextmemchar(s, &tempi);
|
|
if (c == ch) {
|
|
return (char *)&s[i];
|
|
}
|
|
if (i == 0)
|
|
break;
|
|
tempi = i;
|
|
u8_dec(s, &i);
|
|
if (i > tempi)
|
|
break;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
int u8_is_locale_utf8(const char *locale)
|
|
{
|
|
const char *cp;
|
|
|
|
if (locale == NULL)
|
|
return 0;
|
|
|
|
/* this code based on libutf8 */
|
|
cp = locale;
|
|
|
|
for (; *cp != '\0' && *cp != '@' && *cp != '+' && *cp != ','; cp++) {
|
|
if (*cp == '.') {
|
|
const char *encoding = ++cp;
|
|
for (; *cp != '\0' && *cp != '@' && *cp != '+' && *cp != ',';
|
|
cp++)
|
|
;
|
|
if ((cp - encoding == 5 && !strncmp(encoding, "UTF-8", 5)) ||
|
|
(cp - encoding == 4 && !strncmp(encoding, "utf8", 4)))
|
|
return 1; /* it's UTF-8 */
|
|
break;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
size_t u8_vprintf(const char *fmt, va_list ap)
|
|
{
|
|
size_t nc;
|
|
char *buf;
|
|
uint32_t *wcs;
|
|
int cnt;
|
|
|
|
if ((cnt = vsnprintf(0, 0, fmt, ap)) < 0) {
|
|
return 0;
|
|
}
|
|
if (!(buf = calloc(cnt + 1, 1))) {
|
|
return 0;
|
|
}
|
|
vsnprintf(buf, cnt + 1, fmt, ap);
|
|
if (!(wcs = calloc(cnt + 1, sizeof(uint32_t)))) {
|
|
free(buf);
|
|
return 0;
|
|
}
|
|
nc = u8_toucs(wcs, cnt + 1, buf, cnt);
|
|
wcs[nc] = 0;
|
|
printf("%ls", (wchar_t *)wcs);
|
|
free(wcs);
|
|
free(buf);
|
|
return nc;
|
|
}
|
|
|
|
size_t u8_printf(const char *fmt, ...)
|
|
{
|
|
size_t cnt;
|
|
va_list args;
|
|
|
|
va_start(args, fmt);
|
|
|
|
cnt = u8_vprintf(fmt, args);
|
|
|
|
va_end(args);
|
|
return cnt;
|
|
}
|
|
|
|
/* based on the valid_utf8 routine from the PCRE library by Philip Hazel
|
|
|
|
length is in bytes, since without knowing whether the string is valid
|
|
it's hard to know how many characters there are! */
|
|
int u8_isvalid(const char *str, int length)
|
|
{
|
|
const unsigned char *p, *pend = (unsigned char *)str + length;
|
|
unsigned char c;
|
|
int ab;
|
|
|
|
for (p = (unsigned char *)str; p < pend; p++) {
|
|
c = *p;
|
|
if (c < 128)
|
|
continue;
|
|
if ((c & 0xc0) != 0xc0)
|
|
return 0;
|
|
ab = trailingBytesForUTF8[c];
|
|
if (length < ab)
|
|
return 0;
|
|
length -= ab;
|
|
|
|
p++;
|
|
/* Check top bits in the second byte */
|
|
if ((*p & 0xc0) != 0x80)
|
|
return 0;
|
|
|
|
/* Check for overlong sequences for each different length */
|
|
switch (ab) {
|
|
/* Check for xx00 000x */
|
|
case 1:
|
|
if ((c & 0x3e) == 0)
|
|
return 0;
|
|
continue; /* We know there aren't any more bytes to check */
|
|
|
|
/* Check for 1110 0000, xx0x xxxx */
|
|
case 2:
|
|
if (c == 0xe0 && (*p & 0x20) == 0)
|
|
return 0;
|
|
break;
|
|
|
|
/* Check for 1111 0000, xx00 xxxx */
|
|
case 3:
|
|
if (c == 0xf0 && (*p & 0x30) == 0)
|
|
return 0;
|
|
break;
|
|
|
|
/* Check for 1111 1000, xx00 0xxx */
|
|
case 4:
|
|
if (c == 0xf8 && (*p & 0x38) == 0)
|
|
return 0;
|
|
break;
|
|
|
|
/* Check for leading 0xfe or 0xff,
|
|
and then for 1111 1100, xx00 00xx */
|
|
case 5:
|
|
if (c == 0xfe || c == 0xff || (c == 0xfc && (*p & 0x3c) == 0))
|
|
return 0;
|
|
break;
|
|
}
|
|
|
|
/* Check for valid bytes after the 2nd, if any; all must start 10 */
|
|
while (--ab > 0) {
|
|
if ((*(++p) & 0xc0) != 0x80)
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
int u8_reverse(char *dest, char *src, size_t len)
|
|
{
|
|
size_t si = 0, di = len;
|
|
unsigned char c;
|
|
|
|
dest[di] = '\0';
|
|
while (si < len) {
|
|
c = (unsigned char)src[si];
|
|
if ((~c) & 0x80) {
|
|
di--;
|
|
dest[di] = c;
|
|
si++;
|
|
} else {
|
|
switch (c >> 4) {
|
|
case 0xC:
|
|
case 0xD:
|
|
di -= 2;
|
|
*((int16_t *)&dest[di]) = *((int16_t *)&src[si]);
|
|
si += 2;
|
|
break;
|
|
case 0xE:
|
|
di -= 3;
|
|
dest[di] = src[si];
|
|
*((int16_t *)&dest[di + 1]) = *((int16_t *)&src[si + 1]);
|
|
si += 3;
|
|
break;
|
|
case 0xF:
|
|
di -= 4;
|
|
*((int32_t *)&dest[di]) = *((int32_t *)&src[si]);
|
|
si += 4;
|
|
break;
|
|
default:
|
|
return 1;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|