Restructure the library layers

src/os/mem/posix/mem_os_posix.c

@@ -0,0 +1,36 @@
+// vim:fileencoding=utf-8:foldmethod=marker
+
+#include "../../../common/aliases/aliases.h"
+#include "../../../common/platform/platform.h"
+
+#ifdef WAPP_PLATFORM_POSIX
+
+#include "mem_os_posix.h"
+#include "../mem_os_ops.h"
+#include <sys/mman.h>
+
+wapp_intern const i32 access_types[] = {
+    [WAPP_MEM_ACCESS_NONE]            = PROT_NONE,
+    [WAPP_MEM_ACCESS_READ_ONLY]       = PROT_READ,
+    [WAPP_MEM_ACCESS_EXEC_ONLY]       = PROT_EXEC,
+    [WAPP_MEM_ACCESS_READ_WRITE]      = PROT_READ | PROT_WRITE,
+    [WAPP_MEM_ACCESS_READ_EXEC]       = PROT_READ | PROT_EXEC,
+    [WAPP_MEM_ACCESS_READ_WRITE_EXEC] = PROT_READ | PROT_WRITE | PROT_EXEC,
+};
+
+void *mem_util_allocate(void *addr, u64 size, MemAccess access, MemAllocFlags flags, MemInitType type) {
+  (void)type;
+  i32 alloc_flags = flags | MAP_ANON | MAP_PRIVATE;
+
+#if defined(WAPP_PLATFORM_LINUX) || defined(WAPP_PLATFORM_GNU) || defined(WAPP_PLATFORM_NET_BSD)
+  alloc_flags |= MAP_NORESERVE;
+#endif
+
+  return mmap(addr, size, access_types[access], alloc_flags, -1, 0);
+}
+
+void mem_util_free(void *ptr, u64 size) {
+  munmap(ptr, size);
+}
+
+#endif // !WAPP_PLATFORM_POSIX