add compile type for dynamic project compilation

src/rebar_app_discover.erl

@@ -427,7 +427,7 @@ try_handle_app_src_file(AppInfo, _, _AppDir, [], _Validate) ->
     %% a .app after this step
     case filelib:is_file(filename:join(rebar_app_info:dir(AppInfo), "mix.exs")) of
         true ->
-            {true, AppInfo};
+            {true, rebar_app_info:compile_type(AppInfo, mix)};
         false ->
             false
     end;

src/rebar_app_info.erl

@@ -47,6 +47,8 @@
          set/3,
          source/1,
          source/2,
+         compile_type/1,
+         compile_type/2,
          is_lock/1,
          is_lock/2,
          is_checkout/1,
@@ -89,6 +91,7 @@
                      is_lock=false      :: boolean(),
                      is_checkout=false  :: boolean(),
                      valid              :: boolean() | undefined,
+                     compile_type       :: rebar3 | mix | undefined,
                      is_available=false :: boolean()}).
 
 %%============================================================================
@@ -500,6 +503,17 @@ is_available(#app_info_t{is_available=IsAvailable}) ->
 is_available(AppInfo=#app_info_t{}, IsAvailable) ->
     AppInfo#app_info_t{is_available=IsAvailable}.
 
+%% @doc
+-spec compile_type(t()) -> atom().
+compile_type(#app_info_t{compile_type=CompileType}) ->
+    CompileType.
+
+%% @doc
+-spec compile_type(t(), atom()) -> t().
+compile_type(AppInfo=#app_info_t{}, CompileType) ->
+    AppInfo#app_info_t{compile_type=CompileType}.
+
+
 %% @doc returns whether the app is valid (built) or not
 -spec valid(t()) -> boolean().
 valid(AppInfo=#app_info_t{valid=undefined}) ->

src/rebar_prv_compile.erl

@@ -150,7 +150,19 @@ compile(State, Providers, AppInfo) ->
     AppInfo1 = rebar_hooks:run_all_hooks(AppDir, pre, ?PROVIDER,  Providers, AppInfo, State),
 
     AppInfo2 = rebar_hooks:run_all_hooks(AppDir, pre, ?ERLC_HOOK, Providers, AppInfo1, State),
-    rebar_erlc_compiler:compile(AppInfo2),
+
+    case rebar_app_info:compile_type(AppInfo) of
+        mix ->
+            rebar_utils:sh("mix compile --no-deps-check --no-protocol-consolidation",
+                           [{cd, AppDir},
+                            {return_on_error, true},
+                            {use_stdout, true},
+                            {env, [{"MIX_BUILD_PATH", filename:join(AppDir, "../../")},
+                                   {"MIX_ENV", "prod"}]}]);
+        _ ->
+            rebar_erlc_compiler:compile(AppInfo2)
+    end,
+
     AppInfo3 = rebar_hooks:run_all_hooks(AppDir, post, ?ERLC_HOOK, Providers, AppInfo2, State),
 
     AppInfo4 = rebar_hooks:run_all_hooks(AppDir, pre, ?APP_HOOK, Providers, AppInfo3, State),