import from github

tools/preproc/utf8.cpp

@@ -0,0 +1,92 @@
+// Copyright (c) 2008-2009 Bjoern Hoehrmann <bjoern@hoehrmann.de>
+// See http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ for details.
+//
+// Copyright(c) 2016 YamaArashi
+//
+// 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 <cstdint>
+#include "utf8.h"
+
+static const unsigned char s_byteTypeTable[] =
+{
+    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, // 00..1f
+    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, // 20..3f
+    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, // 40..5f
+    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, // 60..7f
+    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, // 80..9f
+    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, // a0..bf
+    8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, // c0..df
+    0xa,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x3,0x4,0x3,0x3, // e0..ef
+    0xb,0x6,0x6,0x6,0x5,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8,0x8, // f0..ff
+};
+
+const unsigned char s0 = 0 * 12;
+const unsigned char s1 = 1 * 12;
+const unsigned char s2 = 2 * 12;
+const unsigned char s3 = 3 * 12;
+const unsigned char s4 = 4 * 12;
+const unsigned char s5 = 5 * 12;
+const unsigned char s6 = 6 * 12;
+const unsigned char s7 = 7 * 12;
+const unsigned char s8 = 8 * 12;
+
+static const unsigned char s_transitionTable[] =
+{
+    s0,s1,s2,s3,s5,s8,s7,s1,s1,s1,s4,s6, // s0
+    s1,s1,s1,s1,s1,s1,s1,s1,s1,s1,s1,s1, // s1
+    s1,s0,s1,s1,s1,s1,s1,s0,s1,s0,s1,s1, // s2
+    s1,s2,s1,s1,s1,s1,s1,s2,s1,s2,s1,s1, // s3
+    s1,s1,s1,s1,s1,s1,s1,s2,s1,s1,s1,s1, // s4
+    s1,s2,s1,s1,s1,s1,s1,s1,s1,s2,s1,s1, // s5
+    s1,s1,s1,s1,s1,s1,s1,s3,s1,s3,s1,s1, // s6
+    s1,s3,s1,s1,s1,s1,s1,s3,s1,s3,s1,s1, // s7
+    s1,s3,s1,s1,s1,s1,s1,s1,s1,s1,s1,s1, // s8
+};
+
+// Decodes UTF-8 encoded Unicode code point at "s".
+UnicodeChar DecodeUtf8(const char* s)
+{
+    UnicodeChar unicodeChar;
+    int state = s0;
+    auto start = s;
+
+    do
+    {
+        unsigned char byte = *s++;
+        int type = s_byteTypeTable[byte];
+
+        if (state == s0)
+            unicodeChar.code = (0xFF >> type) & byte;
+        else
+            unicodeChar.code = (unicodeChar.code << 6) | (byte & 0x3F);
+
+        state = s_transitionTable[state + type];
+
+        if (state == s1)
+        {
+            unicodeChar.code = -1;
+            return unicodeChar;
+        }
+    } while (state != s0);
+
+    unicodeChar.encodingLength = s - start;
+
+    return unicodeChar;
+}