From Lua 5.2: debug.getupvalue() returns "" for C function upvalues.
tree7d73f74cf335332c57a6f900bda62157df78c851
-rw-r--r-- 71 .gitignore
-rw-r--r-- 2932 COPYRIGHT
-rw-r--r-- 5668 Makefile
-rw-r--r-- 455 README
drwxr-xr-x - doc
drwxr-xr-x - dynasm
drwxr-xr-x - etc
drwxr-xr-x - src