build-sys: split internal basic/ library from shared/

basic/      can be used by everything
            cannot use anything outside of basic/

libsystemd/ can use basic/
            cannot use shared/

shared/     can use libsystemd/

src/basic/utf8.h

@@ -0,0 +1,57 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2012 Lennart Poettering
+
+  systemd 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 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdbool.h>
+
+#include "macro.h"
+
+#define UTF8_REPLACEMENT_CHARACTER "\xef\xbf\xbd"
+
+bool unichar_is_valid(uint32_t c);
+
+const char *utf8_is_valid(const char *s) _pure_;
+char *ascii_is_valid(const char *s) _pure_;
+
+bool utf8_is_printable_newline(const char* str, size_t length, bool newline) _pure_;
+#define utf8_is_printable(str, length) utf8_is_printable_newline(str, length, true)
+
+char *utf8_escape_invalid(const char *s);
+char *utf8_escape_non_printable(const char *str);
+
+size_t utf8_encode_unichar(char *out_utf8, uint32_t g);
+char *utf16_to_utf8(const void *s, size_t length);
+
+int utf8_encoded_valid_unichar(const char *str);
+int utf8_encoded_to_unichar(const char *str);
+
+static inline bool utf16_is_surrogate(uint16_t c) {
+        return (0xd800 <= c && c <= 0xdfff);
+}
+
+static inline bool utf16_is_trailing_surrogate(uint16_t c) {
+        return (0xdc00 <= c && c <= 0xdfff);
+}
+
+static inline uint32_t utf16_surrogate_pair_to_unichar(uint16_t lead, uint16_t trail) {
+                return ((lead - 0xd800) << 10) + (trail - 0xdc00) + 0x10000;
+}