use macports-legacy-support for OS X

disabled for macOS onwards
modified version without APSL licensed files

extern/macports-legacy-support/include/string.h

@@ -0,0 +1,56 @@
+
+/*
+ * Copyright (c) 2018 Chris Jones <jonesc@macports.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _MACPORTS_STRING_H_
+#define _MACPORTS_STRING_H_
+
+/* MP support header */
+#include "MacportsLegacySupport.h"
+
+/* Include the primary system string.h */
+#include_next <string.h>
+
+/* stpncpy */
+#if __MP_LEGACY_SUPPORT_STPNCPY__
+__MP__BEGIN_DECLS
+extern char *stpncpy(char *dst, const char *src, size_t n);
+__MP__END_DECLS
+#endif
+
+/* strnlen */
+#if __MP_LEGACY_SUPPORT_STRNLEN__
+__MP__BEGIN_DECLS
+extern size_t strnlen(const char *s, size_t maxlen);
+__MP__END_DECLS
+#endif
+
+/* strndup */
+#if __MP_LEGACY_SUPPORT_STRNDUP__
+__MP__BEGIN_DECLS
+extern char *strndup(const char *s, size_t n);
+__MP__END_DECLS
+#endif
+
+/* memmem */
+#if __MP_LEGACY_SUPPORT_MEMMEM__
+__MP__BEGIN_DECLS
+extern void *
+memmem(const void *l, size_t l_len, const void *s, size_t s_len);
+__MP__END_DECLS
+#endif
+
+#endif /* _MACPORTS_STRING_H_ */