1 files changed, 27 insertions, 0 deletions

diff --git a/win32/lazyload.h b/win32/lazyload.h
new file mode 100644
index 000000000..034bc7e45
--- /dev/null
+++ b/win32/lazyload.h
@@ -0,0 +1,27 @@
+#ifndef LAZYLOAD_H
+#define LAZYLOAD_H
+
+/* simplify loading of DLL functions */
+
+struct proc_addr {
+        FARPROC pfunction;
+        unsigned initialized;
+};
+
+/* Declares a function to be loaded dynamically from a DLL. */
+#define DECLARE_PROC_ADDR(rettype, function, ...) \
+        static struct proc_addr proc_addr_##function = { NULL, 0 }; \
+        rettype (WINAPI *function)(__VA_ARGS__)
+
+/*
+ * Loads a function from a DLL (once-only).
+ * Returns non-NULL function pointer on success.
+ * Returns NULL and sets errno == ENOSYS on failure.
+ */
+#define INIT_PROC_ADDR(dll, function) \
+        (function = get_proc_addr(#dll, #function, &proc_addr_##function))
+
+void *get_proc_addr(const char *dll, const char *function,
+                                        struct proc_addr *proc);
+
+#endif