Use runtime: false for rustler dependency (#559)

When using `runtime: false`, we do not have access to the `Rustler`
module. Thus, we also cannot call `Rustler.construct_load_data/2` when
loading the NIF module. In order to allow `runtime: false` and also
construct `load_data` at load time, we need to add
`construct_load_data/2` to the target module.

CHANGELOG.md

@@ -17,6 +17,7 @@ See [`UPGRADE.md`](./UPGRADE.md) for additional help when upgrading to newer ver
 * Deprecated `:rustler_crates` project configuration
 * Mark `use Rustler` module configuration as compile-time
 * Bump Rust edition to 2021
+* Make `:rustler` a compile-time-only dependency (#516, #559)
 
 ## [0.29.1] - 2023-06-30
 

prepare_release.sh

@@ -41,7 +41,7 @@ sed -i "s/^version = \"[^\"]*\" # rustler_codegen version$/version = \"$VERSION\
 sed -i "s/^rustler.*$/rustler = {path = \"..\/rustler\", version = \"$VERSION\"}/" rustler_bigint/Cargo.toml
 sed -i "s/def rustler_version, do: \"[^\"]*\"$/def rustler_version, do: \"$VERSION\"/" rustler_mix/mix.exs rustler_mix/lib/rustler.ex
 sed -i "s/@version .*$/@version \"$VERSION\"/" rustler_mix/mix.exs
-sed -i "s/{:rustler, \".*\"}/{:rustler, \"~> $VERSION\"}/" rustler_mix/README.md
+sed -i "s/{:rustler, \".*\"/{:rustler, \"~> $VERSION\"/" rustler_mix/README.md
 
 echo "Committing version.."
 git commit -m "(release) $VERSION" \

rustler_benchmarks/mix.exs

@@ -22,7 +22,7 @@ defmodule RustlerBenchmarks.MixProject do
   defp deps do
     [
       {:benchee, "~> 1.0"},
-      {:rustler, path: "../rustler_mix"}
+      {:rustler, path: "../rustler_mix", runtime: false}
     ]
   end
 end

rustler_mix/README.md

@@ -15,7 +15,7 @@ This package is available on [Hex.pm](https://hex.pm/packages/rustler). To insta
 ```elixir
 def deps do
   [
-    {:rustler, "~> 0.29.1"}
+    {:rustler, "~> 0.29.1", runtime: false}
   ]
 end
 ```

rustler_mix/lib/rustler.ex

@@ -114,6 +114,9 @@ defmodule Rustler do
   end
 
   defmacro __before_compile__(_env) do
+    default_load_data_value = %Rustler.Compiler.Config{}.load_data
+    default_fun_value = %Rustler.Compiler.Config{}.load_data_fun
+
     quote do
       @on_load :rustler_init
 
@@ -130,37 +133,37 @@ defmodule Rustler do
           |> Application.app_dir(path)
           |> to_charlist()
 
-        load_data = Rustler.construct_load_data(@load_data, @load_data_fun)
+        load_data = _construct_load_data(@load_data, @load_data_fun)
 
         :erlang.load_nif(load_path, load_data)
       end
-    end
-  end
 
-  def construct_load_data(load_data, load_data_fun) do
-    default_load_data_value = %Rustler.Compiler.Config{}.load_data
-    default_fun_value = %Rustler.Compiler.Config{}.load_data_fun
-
-    case {load_data, load_data_fun} do
-      {load_data, ^default_fun_value} ->
-        load_data
-
-      {^default_load_data_value, {module, function}}
-      when is_atom(module) and is_atom(function) ->
-        apply(module, function, [])
-
-      {^default_load_data_value, provided_value} ->
-        raise """
-        `load_data` has to be `{Module, :function}`.
-        Instead received: #{inspect(provided_value)}
-        """
-
-      {load_data, load_data_fun} ->
-        raise """
-        Only `load_data` or `load_data_fun` can be provided. Instead received:
-        >>> load_data: #{inspect(load_data)}
-        >>> load_data_fun: #{inspect(load_data_fun)}
-        """
+      defp _construct_load_data(load_data, load_data_fun) do
+        default_load_data_value = unquote(default_load_data_value)
+        default_fun_value = unquote(default_fun_value)
+
+        case {load_data, load_data_fun} do
+          {load_data, ^default_fun_value} ->
+            load_data
+
+          {^default_load_data_value, {module, function}}
+          when is_atom(module) and is_atom(function) ->
+            apply(module, function, [])
+
+          {^default_load_data_value, provided_value} ->
+            raise """
+            `load_data` has to be `{Module, :function}`.
+            Instead received: #{inspect(provided_value)}
+            """
+
+          {load_data, load_data_fun} ->
+            raise """
+            Only `load_data` or `load_data_fun` can be provided. Instead received:
+            >>> load_data: #{inspect(load_data)}
+            >>> load_data_fun: #{inspect(load_data_fun)}
+            """
+        end
+      end
     end
   end
 

rustler_mix/test.sh

@@ -47,7 +47,7 @@ defmodule TestRustlerMix.MixProject do
 
   def application, do: [ ]
 
-  defp deps, do: [ {:rustler, path: "$rustler_mix"} ]
+  defp deps, do: [ {:rustler, path: "$rustler_mix", runtime: false} ]
 end
 EOF
 
@@ -90,5 +90,10 @@ EOF
 
 mix test
 
+# See https://github.com/rusterlium/rustler/issues/516, we also need to verify that everything
+# we need is part of a release.
+mix release
+_build/dev/rel/test_rustler_mix/bin/test_rustler_mix eval 'RustlerMixTest.add(1, 2)'
+
 echo "Done; cleaning up"
 rm -r $tmp