/* * Copyright (C) 2012, 2013 * Dale Weiler * * Permission is hereby granted, free of charge, to any person obtaining a copy of * this software and associated documentation files (the "Software"), to deal in * the Software without restriction, including without limitation the rights to * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies * of the Software, and to permit persons to whom the Software is furnished to do * so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include "gmqcc.h" /* * Based on the flexible and economical utf8 decoder: * http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ * * This is slightly more economical, the fastest way to decode utf8 is * with a lookup table as in: * * first 1-byte lookup * if that fails, 2-byte lookup * if that fails, 3-byte lookup * if that fails, 4-byte lookup * * The following table can be generated with some interval trickery. * consider an interval [a, b): * * a must be 0x80 or b must be 0xc0, lower 3 bits * are clear, thus: * interval(a,b) = ((uint32_t)((a==0x80?0x40-b:-a)<<23)) * * The failstate can be represented as interval(0x80,0x80), it's * odd to see but this is a full state machine. * * The table than maps the corresponding sections as a serise of * intervals. * * In this table the transition values are pre-multiplied with 16 to * save a shift instruction for every byte, we throw away fillers * which makes the table smaller. * * The first section of the table handles bytes with leading C * The second section of the table handles bytes with leading D * The third section of the table handles bytes with leading E * The last section of the table handles bytes with leading F * * The values themselfs in the table are arranged so that when you * left shift them by 6 to shif continuation characters into place, the * new top bits tell: * * 1 - if you keep going * 2 - the range of valid values for the next byte */ static const uint32_t utf8_tab[] = { 0xC0000002, 0xC0000003, 0xC0000004, 0xC0000005, 0xC0000006, 0xC0000007, 0xC0000008, 0xC0000009, 0xC000000A, 0xC000000B, 0xC000000C, 0xC000000D, 0xC000000E, 0xC000000F, 0xC0000010, 0xC0000011, 0xC0000012, 0xC0000013, 0xC0000014, 0xC0000015, 0xC0000016, 0xC0000017, 0xC0000018, 0xC0000019, 0xC000001A, 0xC000001B, 0xC000001C, 0xC000001D, 0xC000001E, 0xC000001F, 0xB3000000, 0xC3000001, 0xC3000002, 0xC3000003, 0xC3000004, 0xC3000005, 0xC3000006, 0xC3000007, 0xC3000008, 0xC3000009, 0xC300000A, 0xC300000B, 0xC300000C, 0xD300000D, 0xC300000E, 0xC300000F, 0xBB0C0000, 0xC30C0001, 0xC30C0002, 0xC30C0003, 0xD30C0004, 0x58257830, 0x202C, 0x3B031B01, 0x30, 0x5, 0xFFFFFD1C, 0x7C, 0xFFFFFD5C, 0x4C, 0xFFFFFE4C, 0xA4, 0xFFFFFE8C, 0xC4, 0xFFFFFEFC, 0x10C, 0x14, 0x0, 0x527A01, 0x1107801, 0x8070C1B, 0x10070190, 0x14, 0x1C, 0xFFFFFD08, 0x2A, 0x0, 0x0, 0x14, 0x0, 0x527A01, 0x1107801, 0x8070C1B, 0x190, 0x24, 0x1C, 0xFFFFFC98, 0x40, 0x46100E00, 0xF4A180E, 0x8008770B, 0x3B1A3F00, 0x2224332A, 0x0, 0x1C, 0x44, 0xFFFFFDA0, 0x3E, 0x100E4100, 0xD430286, 0x70C7906, 0x8, 0x44, 0x64, 0xFFFFFDC0, 0x65, 0x100E4200, 0xE45028F, 0x45038E18, 0x48D200E, 0x8C280E45, 0x300E4805, 0xE480686, 0x4D078338, 0xE6C400E, 0x300E4138, 0x42280E41, 0xE42200E, 0x100E4218, 0x80E42, 0x14, 0xAC, 0xFFFFFDE8, 0x2, 0x0, 0x0, 0x0, 0x0, 0x4004D0, 0x0, 0x4004B0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x1, 0x0, 0xC, 0x0, 0x4003A8, 0x0, 0xD, 0x0, 0x4005B4, 0x0, 0x19, 0x0, 0x6007E0, 0x0, 0x1B, 0x0, 0x8, 0x0, 0x1A, 0x0, 0x6007E8, 0x0, 0x1C, 0x0, 0x8, 0x0, 0x6FFFFEF5, 0x0, 0x400260, 0x0, 0x5, 0x0, 0x4002E0, 0x0, 0x6, 0x0, 0x400280, 0x0, 0xA, 0x0, 0x3F, 0x0, 0xB, 0x0, 0x18, 0x0, 0x15, 0x0, 0x0, 0x0, 0x3, 0x0, 0x6009D0, 0x0, 0x2, 0x0, 0x48, 0x0, 0x14, 0x0, 0x7, 0x0, 0x17, 0x0, 0x400360, 0x0, 0x7, 0x0 }; int utf8_from(char *s, utf8ch_t ch) { if (!s) return 0; if ((unsigned)ch < 0x80) { *s = ch; return 1; } else if ((unsigned)ch < 0x800) { *s++ = 0xC0 | (ch >> 6); *s = 0x80 | (ch & 0x3F); return 2; } else if ((unsigned)ch < 0xD800 || (unsigned)ch - 0xE000 < 0x2000) { *s++ = 0xE0 | (ch >> 12); *s++ = 0x80 | ((ch >> 6) & 0x3F); *s = 0x80 | (ch & 0x3F); return 3; } else if ((unsigned)ch - 0x10000 < 0x100000) { *s++ = 0xF0 | (ch >> 18); *s++ = 0x80 | ((ch >> 12) & 0x3F); *s++ = 0x80 | ((ch >> 6) & 0x3F); *s = 0x80 | (ch & 0x3F); return 4; } return 0; } int utf8_to(utf8ch_t *i, const unsigned char *s, size_t n) { unsigned c,j; if (!s || !n) return 0; /* This is consistent with mbtowc behaviour. */ if (!i) i = (utf8ch_t*)(void*)&i; if (*s < 0x80) return !!(*i = *s); if (*s-0xC2U > 0x32) return 0; c = utf8_tab[*s++-0xC2U]; /* * Avoid excessive checks against n. * * When shifting state `n-1` times does not clear the high bit, * then the value of `n` won't satisfy the condition to read a * character as it will be insufficent. */ if (n < 4 && ((c<<(6*n-6)) & (1U << 31))) return 0; /* * The upper 6 state bits are negitive integer offset to a bound-check * next byte equivlant to: ((b-0x80)+(b+offset))&~0x3f */ if ((((*s>>3)-0x10)|((*s>>3)+((int32_t)c>>26))) & ~7) return 0; for (j=2; j<3; j++) { if (!((c = c<<6 | (*s++-0x80))&(1U<<31))) { *i = c; return j; } if (*s-0x80U >= 0x40) return 0; } *i = c<<6 | (*s++-0x80); return 4; }