Run rustc separately for each target

Author: evnu

rustler_mix/lib/rustler/compiler.ex

@@ -15,25 +15,26 @@ defmodule Rustler.Compiler do
 
       Mix.shell().info("Compiling crate #{config.crate} in #{config.mode} mode (#{config.path})")
 
-      [cmd | args] =
+      cmd_line =
         make_base_command(config.cargo)
         |> make_no_default_features_flag(config.default_features)
         |> make_features_flag(config.features)
         |> make_target_flag(config.target)
         |> make_build_mode_flag(config.mode)
-        |> make_platform_hacks(crate_full_path, :os.type())
-
-      compile_result =
-        System.cmd(cmd, args,
-          cd: crate_full_path,
-          stderr_to_stdout: true,
-          env: [{"CARGO_TARGET_DIR", config.target_dir} | config.env],
-          into: IO.stream(:stdio, :line)
-        )
-
-      case compile_result do
-        {_, 0} -> :ok
-        {_, code} -> raise "Rust NIF compile error (rustc exit code #{code})"
+
+      for [cmd | args] <- make_platform_hacks(cmd_line, crate_full_path, :os.type()) do
+        compile_result =
+          System.cmd(cmd, args,
+            cd: crate_full_path,
+            stderr_to_stdout: true,
+            env: [{"CARGO_TARGET_DIR", config.target_dir} | config.env],
+            into: IO.stream(:stdio, :line)
+          )
+
+        case compile_result do
+          {_, 0} -> :ok
+          {_, code} -> raise "Rust NIF compile error (rustc exit code #{code})"
+        end
       end
 
       handle_artifacts(crate_full_path, config)
@@ -61,12 +62,12 @@ defmodule Rustler.Compiler do
     ["rustup", "run", version, "cargo", "rustc"]
   end
 
-  defp make_platform_hacks(args, crate_path, {:unix, :darwin}) do
+  defp make_platform_hacks(cmd_line, crate_path, {:unix, :darwin}) do
     root = Path.join([".cargo", "config"])
     path = Path.join([crate_path, ".cargo", "config"])
 
     if File.exists?(root) || File.exists?(path) do
-      args
+      [cmd_line]
     else
       IO.write([
         "\n",
@@ -96,11 +97,21 @@ defmodule Rustler.Compiler do
         "\n"
       ])
 
-      args ++ ["--", "-C", "link-arg=-undefined", "-C", "link-arg=dynamic_lookup"]
+      for {name, type} <- names(crate_path) do
+        type_switch =
+          if type == :lib do
+            ["--lib"]
+          else
+            ["--bin", name]
+          end
+
+        cmd_line ++
+          type_switch ++ ["--", "-C", "link-arg=-undefined", "-C", "link-arg=dynamic_lookup"]
+      end
     end
   end
 
-  defp make_platform_hacks(args, _, _), do: args
+  defp make_platform_hacks(cmd_line, _, _), do: [cmd_line]
 
   defp make_no_default_features_flag(args, true), do: args
   defp make_no_default_features_flag(args, false), do: args ++ ["--no-default-features"]
@@ -115,10 +126,7 @@ defmodule Rustler.Compiler do
   defp make_build_mode_flag(args, :debug), do: args
 
   defp handle_artifacts(path, config) do
-    toml = toml_data(path)
-    names = get_name(toml, :lib) ++ get_name(toml, :bin)
-
-    Enum.each(names, fn {name, type} ->
+    Enum.each(names(path), fn {name, type} ->
       {src_file, dst_file} = make_file_names(name, type)
       compiled_lib = Path.join([config.target_dir, Atom.to_string(config.mode), src_file])
       destination_lib = Path.join(priv_dir(), dst_file)
@@ -132,6 +140,11 @@ defmodule Rustler.Compiler do
     end)
   end
 
+  defp names(path) do
+    toml = toml_data(path)
+    get_name(toml, :lib) ++ get_name(toml, :bin)
+  end
+
   defp get_name(toml, section) do
     case toml[to_string(section)] do
       nil -> []