| /* |
| * Copyright © 2012 Intel Corporation |
| * Copyright © 2014 Ran Benita <ran234@gmail.com> |
| * |
| * 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 (including the next |
| * paragraph) 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. |
| * |
| * Author: Rob Bradford <rob@linux.intel.com> |
| */ |
| |
| #include "config.h" |
| |
| #include <stddef.h> |
| #include <stdbool.h> |
| #include <inttypes.h> |
| |
| #include "utf8.h" |
| |
| int |
| utf32_to_utf8(uint32_t unichar, char *buffer) |
| { |
| int count, shift, length; |
| uint8_t head; |
| |
| if (unichar <= 0x007f) { |
| buffer[0] = unichar; |
| buffer[1] = '\0'; |
| return 2; |
| } |
| else if (unichar <= 0x07FF) { |
| length = 2; |
| head = 0xc0; |
| } |
| else if (unichar <= 0xffff) { |
| length = 3; |
| head = 0xe0; |
| } |
| else if (unichar <= 0x10ffff) { |
| length = 4; |
| head = 0xf0; |
| } |
| else { |
| buffer[0] = '\0'; |
| return 0; |
| } |
| |
| for (count = length - 1, shift = 0; count > 0; count--, shift += 6) |
| buffer[count] = 0x80 | ((unichar >> shift) & 0x3f); |
| |
| buffer[0] = head | ((unichar >> shift) & 0x3f); |
| buffer[length] = '\0'; |
| |
| return length + 1; |
| } |
| |
| bool |
| is_valid_utf8(const char *ss, size_t len) |
| { |
| size_t i = 0; |
| size_t tail_bytes = 0; |
| const uint8_t *s = (const uint8_t *) ss; |
| |
| /* This beauty is from: |
| * The Unicode Standard Version 6.2 - Core Specification, Table 3.7 |
| * https://www.unicode.org/versions/Unicode6.2.0/ch03.pdf#G7404 |
| * We can optimize if needed. */ |
| while (i < len) |
| { |
| if (s[i] <= 0x7F) { |
| tail_bytes = 0; |
| } |
| else if (s[i] >= 0xC2 && s[i] <= 0xDF) { |
| tail_bytes = 1; |
| } |
| else if (s[i] == 0xE0) { |
| i++; |
| if (i >= len || !(s[i] >= 0xA0 && s[i] <= 0xBF)) |
| return false; |
| tail_bytes = 1; |
| } |
| else if (s[i] >= 0xE1 && s[i] <= 0xEC) { |
| tail_bytes = 2; |
| } |
| else if (s[i] == 0xED) { |
| i++; |
| if (i >= len || !(s[i] >= 0x80 && s[i] <= 0x9F)) |
| return false; |
| tail_bytes = 1; |
| } |
| else if (s[i] >= 0xEE && s[i] <= 0xEF) { |
| tail_bytes = 2; |
| } |
| else if (s[i] == 0xF0) { |
| i++; |
| if (i >= len || !(s[i] >= 0x90 && s[i] <= 0xBF)) |
| return false; |
| tail_bytes = 2; |
| } |
| else if (s[i] >= 0xF1 && s[i] <= 0xF3) { |
| tail_bytes = 3; |
| } |
| else if (s[i] == 0xF4) { |
| i++; |
| if (i >= len || !(s[i] >= 0x80 && s[i] <= 0x8F)) |
| return false; |
| tail_bytes = 2; |
| } |
| else { |
| return false; |
| } |
| |
| i++; |
| |
| while (i < len && tail_bytes > 0 && s[i] >= 0x80 && s[i] <= 0xBF) { |
| i++; |
| tail_bytes--; |
| } |
| |
| if (tail_bytes != 0) |
| return false; |
| } |
| |
| return true; |
| } |