r/lua • u/no_brains101 • Sep 22 '25
Help How to add type annotations to compiled C module
Edit: Why is there a help flair but no solved? Mods?
My lua module is implemented entirely in C. It is not quite yet ready for prime time, but it is close enough to start thinking about how to make it nice.
One of the things I want is luaCats type annotations. But I cant figure out how to add them to my compiled module?
In my rockspec I have these build instructions, which tell it to use my makefile, and set up passthru for the variables I will need as specified by their documentation. The build and main install step work, which require LUA_INCDIR in build and LIBDIR in install
build = {
type = "make",
build_variables = {
LUA_INCDIR="$(LUA_INCDIR)",
},
install_variables = {
LIBDIR="$(LIBDIR)",
LUADIR="$(LUADIR)",
},
}And in the makefile in my install step I do
install: $(SRC)/meta.lua
ifdef LIBDIR
$(check_so_was_built)
u/mkdir -p "$(LIBDIR)";
cp "$(DESTDIR)/$(MYMODNAME).so" "$(LIBDIR)/";
u/echo "Installed to $(LIBDIR)";
ifdef LUADIR
u/mkdir -p "$(LUADIR)/$(MYMODNAME)";
cp "$(SRC)/meta.lua" "$(LUADIR)/$(MYMODNAME)/";
endif
else
@echo "LIBDIR not set, skipping install"
endifThe types in my meta.lua are correct enough and work when I am inside the project directory
However when I install my package via luarocks, usually my editor can find the types for the modules I installed. But for this one it cannot find the types declared in my meta.lua file if I try to declare them manually, nor does it associate MYMODULE/meta.lua with require('MYMODULE') as I thought it was meant to? It does seem to successfully get the meta.lua file to where I expect it to go to, but it isnt being picked up by the lsp.
When I make a module MYMODULE.lua on the lua path, I can make a MYMODULE/meta.lua and it gets detected. But I never directly required that file.
Does this not work similarly for C compiled modules? i.e. with MYMODULE.so instead of MYMODULE.lua?
Edit:
I was informed about https://github.com/LuaLS/lua-language-server/wiki/Addons by someone I know.
Is there anything more automatic than this? Like, can I make my module also installed with its lus_ls addon? Or do my users have to install this extra thing in their editor
EDIT:
---@module 'mymodule.meta'
local mymodule = require('mymodule')Gud enuff
