Move os layer to be part of the core

src/core/os/cpath/cpath.h

@@ -0,0 +1,38 @@
+#ifndef CPATH_H
+#define CPATH_H
+
+#include "aliases.h"
+#include "mem_allocator.h"
+#include "platform.h"
+#include "str8.h"
+
+#ifdef __cplusplus
+BEGIN_C_LINKAGE
+#endif // __cplusplus
+
+#ifdef WAPP_PLATFORM_POSIX
+#define PATH_SEP '/'
+#elif defined(WAPP_PLATFORM_WINDOWS)
+#define PATH_SEP '\\'
+#else
+#error "Unrecognised platform"
+#endif
+
+#define wapp_cpath_dirname(ALLOCATOR, PATH) dirup(ALLOCATOR, PATH, 1)
+#define wapp_cpath_dirup(ALLOCATOR, PATH, COUNT) dirup(ALLOCATOR, PATH, COUNT)
+
+enum {
+  CPATH_JOIN_SUCCESS = 0,
+  CPATH_JOIN_INVALID_ARGS,
+  CPATH_JOIN_EMPTY_PARTS,
+  CPATH_JOIN_INSUFFICIENT_DST_CAPACITY,
+};
+
+u32  wapp_cpath_join_path(Str8 *dst, const Str8List *parts);
+Str8 *dirup(const Allocator *allocator, Str8RO *path, u64 levels);
+
+#ifdef __cplusplus
+END_C_LINKAGE
+#endif // __cplusplus
+
+#endif // !CPATH_H