| /*============================================================================ |
| CMake - Cross Platform Makefile Generator |
| Copyright 2000-2009 Kitware, Inc., Insight Software Consortium |
| |
| Distributed under the OSI-approved BSD License (the "License"); |
| see accompanying file Copyright.txt for details. |
| |
| This software is distributed WITHOUT ANY WARRANTY; without even the |
| implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| See the License for more information. |
| ============================================================================*/ |
| #include "cm_utf8.h" |
| |
| /* |
| RFC 3629 |
| 07-bit: 0xxxxxxx |
| 11-bit: 110xxxxx 10xxxxxx |
| 16-bit: 1110xxxx 10xxxxxx 10xxxxxx |
| 21-bit: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx |
| |
| Pre-RFC Compatibility |
| 26-bit: 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx |
| 31-bit: 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx |
| */ |
| |
| /* Number of leading ones before a zero in the byte. */ |
| static unsigned char const cm_utf8_ones[256] = { |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, |
| 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, |
| 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, |
| 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,6,6,7,8 |
| }; |
| |
| /* Mask away control bits from bytes with n leading ones. */ |
| static unsigned char const cm_utf8_mask[7] = { |
| 0xEF, 0x3F, 0x1F, 0x0F, 0x07, 0x03, 0x01 |
| }; |
| |
| /* Minimum allowed value when first byte has n leading ones. */ |
| static unsigned int const cm_utf8_min[7] = { |
| 0, 0, 1u<<7, 1u<<11, 1u<<16, 1u<<21, 1u<<26 /*, 1u<<31 */ |
| }; |
| |
| /*--------------------------------------------------------------------------*/ |
| const char* cm_utf8_decode_character(const char* first, const char* last, |
| unsigned int* pc) |
| { |
| /* Count leading ones in the first byte. */ |
| unsigned char c = (unsigned char)*first++; |
| unsigned char const ones = cm_utf8_ones[c]; |
| switch(ones) |
| { |
| case 0: *pc = c; return first; /* One-byte character. */ |
| case 1: case 7: case 8: return 0; /* Invalid leading byte. */ |
| default: break; |
| } |
| |
| /* Extract bits from this multi-byte character. */ |
| { |
| unsigned int uc = c & cm_utf8_mask[ones]; |
| int left; |
| for(left = ones-1; left && first != last; --left) |
| { |
| c = (unsigned char)*first++; |
| if(cm_utf8_ones[c] != 1) |
| { |
| return 0; |
| } |
| uc = (uc << 6) | (c & cm_utf8_mask[1]); |
| } |
| |
| if(left > 0 || uc < cm_utf8_min[ones]) |
| { |
| return 0; |
| } |
| |
| *pc = uc; |
| return first; |
| } |
| } |