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-rw-r--r--lib/unistr/u8-check.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/lib/unistr/u8-check.c b/lib/unistr/u8-check.c
new file mode 100644
index 0000000..53897fc
--- /dev/null
+++ b/lib/unistr/u8-check.c
@@ -0,0 +1,105 @@
+/* Check UTF-8 string.
+ Copyright (C) 2002, 2006-2007 Free Software Foundation, Inc.
+ Written by Bruno Haible <bruno@clisp.org>, 2002.
+
+ This program is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published
+ by the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include "unistr.h"
+
+const uint8_t *
+u8_check (const uint8_t *s, size_t n)
+{
+ const uint8_t *s_end = s + n;
+
+ while (s < s_end)
+ {
+ /* Keep in sync with unistr.h and utf8-ucs4.c. */
+ uint8_t c = *s;
+
+ if (c < 0x80)
+ {
+ s++;
+ continue;
+ }
+ if (c >= 0xc2)
+ {
+ if (c < 0xe0)
+ {
+ if (s + 2 <= s_end
+ && (s[1] ^ 0x80) < 0x40)
+ {
+ s += 2;
+ continue;
+ }
+ }
+ else if (c < 0xf0)
+ {
+ if (s + 3 <= s_end
+ && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
+ && (c >= 0xe1 || s[1] >= 0xa0)
+ && (c != 0xed || s[1] < 0xa0))
+ {
+ s += 3;
+ continue;
+ }
+ }
+ else if (c < 0xf8)
+ {
+ if (s + 4 <= s_end
+ && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
+ && (s[3] ^ 0x80) < 0x40
+ && (c >= 0xf1 || s[1] >= 0x90)
+#if 1
+ && (c < 0xf4 || (c == 0xf4 && s[1] < 0x90))
+#endif
+ )
+ {
+ s += 4;
+ continue;
+ }
+ }
+#if 0
+ else if (c < 0xfc)
+ {
+ if (s + 5 <= s_end
+ && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
+ && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
+ && (c >= 0xf9 || s[1] >= 0x88))
+ {
+ s += 5;
+ continue;
+ }
+ }
+ else if (c < 0xfe)
+ {
+ if (s + 6 <= s_end
+ && (s[1] ^ 0x80) < 0x40 && (s[2] ^ 0x80) < 0x40
+ && (s[3] ^ 0x80) < 0x40 && (s[4] ^ 0x80) < 0x40
+ && (s[5] ^ 0x80) < 0x40
+ && (c >= 0xfd || s[1] >= 0x84))
+ {
+ s += 6;
+ continue;
+ }
+ }
+#endif
+ }
+ /* invalid or incomplete multibyte character */
+ return s;
+ }
+ return NULL;
+}