Handles multiple crates per project

Author: sdwolfz

README.md

@@ -1,6 +1,6 @@
 # rebar3_rust
 
-Compile rust NIFs for erlang projects.
+Compile rust crates for erlang projects.
 
 ## Use
 
@@ -34,6 +34,15 @@ Add the plugin and hooks to your `rebar.config`
 }.
 ```
 
+Add the following to your `.gitignore`
+
+```
+crates/*/target
+priv/*
+!priv/.keep
+```
+
+
 You can find an example usage [here](https://github.com/sdwolf/rustfromerl).
 
 ## Upgrade

src/rebar3_prv_rust_compile.erl

@@ -28,7 +28,7 @@ init(State) ->
 
 -spec do(rebar_state:t()) -> {ok, rebar_state:t()} | {error, string()}.
 do(State) ->
-  NewState = rebar3_rust_utils:compile_nifs(State),
+  NewState = rebar3_rust_utils:compile_crates(State),
 
   {ok, NewState}.
 

src/rebar3_rust_utils.erl

@@ -1,46 +1,62 @@
 -module(rebar3_rust_utils).
 
 -export([
-  compile_nifs/1
+  compile_crates/1
 ]).
 
 %% ===================================================================
 %% Public API
 %% ===================================================================
 
-compile_nifs(State) ->
-  App        = rebar_state:current_app(State),
-  AppDir     = rebar_app_info:dir(App),
-  RustNifDir = filename:join(AppDir, "rust_nif"),
+compile_crates(State) ->
+  App     = rebar_state:current_app(State),
+  AppName = binary_to_list(rebar_app_info:name(App)),
+  AppDir  = rebar_app_info:dir(App),
+  PrivDir = code:priv_dir(AppName),
 
+  CratesDir  = filename:join(AppDir, "crates"),
+  CratesGlob = filename:join(CratesDir, "*"),
+  Crates     = filelib:wildcard(CratesGlob),
+
+  lists:foreach(
+    fun(CrateDir) -> compile_crate(CrateDir, PrivDir) end,
+    Crates
+  ),
+
+  State.
+
+%% ===================================================================
+%% Internal functions
+%% ===================================================================
+
+compile_crate(CrateDir, PrivDir) ->
   Command = "cargo build --release -j$(nproc)",
-  {ok, _} = rebar_utils:sh(Command, [{cd, rust_nif}, {use_stdout, true}]),
 
-  SOGlob  = filename:join([RustNifDir, "target", "release", "*.so"]),
+  {ok, _} = rebar_utils:sh(Command, [{cd, CrateDir}, {use_stdout, true}]),
+
+  SOGlob  = filename:join([CrateDir, "target", "release", "*.so"]),
   SOFiles = filelib:wildcard(SOGlob),
 
-  AppName      = binary_to_list(rebar_app_info:name(App)),
-  PrivDir      = code:priv_dir(AppName),
-  Destination  = filename:join(PrivDir, "rust_nif"),
-  OldFilesGlob = filename:join(Destination, "*.so"),
-  OldFiles     = filelib:wildcard(OldFilesGlob),
+  CratesPrivDir = filename:join(PrivDir, "crates"),
+
+  file:make_dir(CratesPrivDir),
+
+  CrateName     = filename:basename(CrateDir),
+  Destination   = filename:join(CratesPrivDir, CrateName),
+  OldFilesGlob  = filename:join(Destination, "*.so"),
+  OldFiles      = filelib:wildcard(OldFilesGlob),
 
   file:make_dir(Destination),
 
   lists:foreach(
     fun(File) -> remove_file(File) end,
     OldFiles
   ),
+
   lists:foreach(
     fun(File) -> copy_file(File, Destination) end,
     SOFiles
-  ),
-
-  State.
-
-%% ===================================================================
-%% Internal functions
-%% ===================================================================
+  ).
 
 copy_file(SourceFile, DestinationDir) ->
   Extension = filename:extension(SourceFile),