1 files changed, 15 insertions, 1 deletions
diff --git a/dmyext.c b/dmyext.c
index 4120d493c3..66be95ab4e 100644
--- a/dmyext.c
+++ b/dmyext.c
@@ -1,4 +1,18 @@
+// This file is used by dynamically-linked ruby, which has no
+// statically-linked extension libraries.
+//
+// - miniruby does not use this Init_ext. Instead, "miniinit.c"
+//   provides Init_enc, which does nothing too. It does not support
+//   require'ing extension libraries.
+//
+// - Dynamically-linked ruby uses this Init_ext, which does
+//   nothing. It loads extension libraries by dlopen, etc.
+//
+// - Statically-linked ruby does not use this Init_ext. Instead,
+//   "ext/extinit.c" (which is a generated file) defines Init_ext,
+//   which activates the (statically-linked) extension libraries.
+
 void
-Init_ext()
+Init_ext(void)
 {
 }