Refactoring core logic in preparation for dependency mgmt; breaking out sub_dir determination into dedicated module

ebin/rebar.app

@@ -3,9 +3,10 @@
   {vsn, "2"},
   {modules, [ rebar,
               rebar_app_utils,
-              rebar_config,
+              rebar_config,              
               rebar_core,
               rebar_ct,
+              rebar_deps,
               rebar_erlc_compiler,
               rebar_escripter,
               rebar_eunit,
@@ -19,6 +20,7 @@
               rebar_port_compiler,
               rebar_rel_utils,
               rebar_reltool,
+              rebar_subdirs,
               rebar_utils ]},
   {registered, []},
   {applications, [kernel, 
@@ -28,18 +30,29 @@
          %% Default log level
          {log_level, error},
 
-         %% Processing modules
+         %% any_dir processing modules
+         {any_dir_modules, [
+                            rebar_subdirs,
+                            rebar_deps
+                           ]},
+
+         %% Dir specific processing modules
          {modules, [
-                    {app_dir, [ rebar_protobuffs_compiler,
-                                rebar_erlc_compiler,
-                                rebar_lfe_compiler,
-                                rebar_erlydtl_compiler,
-                                rebar_port_compiler,
-                                rebar_otp_app,
-                                rebar_ct,
-                                rebar_eunit,
-                                rebar_escripter]},
-                    {rel_dir, [ rebar_reltool ]}
+                    {app_dir, [
+                               rebar_protobuffs_compiler,
+                               rebar_erlc_compiler,
+                               rebar_lfe_compiler,
+                               rebar_erlydtl_compiler,
+                               rebar_port_compiler,
+                               rebar_otp_app,
+                               rebar_ct,
+                               rebar_eunit,
+                               rebar_escripter
+                              ]},
+                    
+                    {rel_dir, [
+                               rebar_reltool
+                              ]}
                    ]}
         ]}
 ]}.

src/rebar_core.erl

@@ -30,6 +30,7 @@
 
 -include("rebar.hrl").
 
+
 -ifndef(BUILD_TIME).
 -define(BUILD_TIME, "undefined").
 -endif.
@@ -92,35 +93,33 @@ filter_flags([Item | Rest], Commands) ->
 process_dir(Dir, ParentConfig, Commands) ->
     ok = file:set_cwd(Dir),
     Config = rebar_config:new(ParentConfig),
-
+    
     %% Save the current code path and then update it with
     %% lib_dirs. Children inherit parents code path, but we
     %% also want to ensure that we restore everything to pristine
     %% condition after processing this child
     CurrentCodePath = update_code_path(Config),
 
-    %% If there are any subdirs specified, process those first...
-    case rebar_config:get(Config, sub_dirs, []) of
-        [] ->
-            ok;
-        Subdirs ->
-            %% Edge case: config is inherited, EXCEPT for sub_dir directives -- filter those out
-            FilteredConfig = rebar_config:delete(Config, sub_dirs),
-            [process_dir(filename:join(Dir, Subdir), FilteredConfig, Commands) ||
-                Subdir <- Subdirs],
-            ok = file:set_cwd(Dir)
-    end,
-
     %% Get the list of processing modules and check each one against
     %% CWD to see if it's a fit -- if it is, use that set of modules
     %% to process this dir.
     {ok, AvailModuleSets} = application:get_env(rebar, modules),
-    case choose_module_set(AvailModuleSets, Dir) of
-        {ok, Modules, ModuleSetFile} ->
-            apply_commands(Commands, Modules, Config, ModuleSetFile);
-        none ->
-            ok
-    end,
+    {DirModules, ModuleSetFile} = choose_module_set(AvailModuleSets, Dir),
+
+    %% Get the list of modules for "any dir". This is a catch-all list of modules
+    %% that are processed in addion to modules associated with this directory
+    %5 type. These any_dir modules are processed FIRST.
+    {ok, AnyDirModules} = application:get_env(rebar, any_dir_modules),
+    Modules = AnyDirModules ++ DirModules,
+
+    %% Give the modules a chance to tweak config and indicate if there
+    %% are any other dirs that might need processing first.
+    {UpdatedConfig, Dirs} = acc_modules(select_modules(Modules, preprocess, []),
+                                        preprocess, Config, ModuleSetFile, []),
+    [process_dir(D, UpdatedConfig, Commands) || D <- Dirs],
+
+    %% Finally, process the current working directory
+    apply_commands(Commands, Modules, UpdatedConfig, ModuleSetFile),
 
     %% Once we're all done processing, reset the code path to whatever
     %% the parent initialized it to
@@ -128,15 +127,15 @@ process_dir(Dir, ParentConfig, Commands) ->
     ok.
 
 %%
-%% Give a list of module sets from rebar.app and a directory, find
+%% Given a list of module sets from rebar.app and a directory, find
 %% the appropriate subset of modules for this directory
 %%
 choose_module_set([], _Dir) ->
-    none;
+    {[], undefined};
 choose_module_set([{Fn, Modules} | Rest], Dir) ->
     case ?MODULE:Fn(Dir) of
         {true, File} ->
-            {ok, Modules, File};
+            {Modules, File};
         false ->
             choose_module_set(Rest, Dir)
     end.
@@ -228,4 +227,13 @@ run_modules([Module | Rest], Command, Config, File) ->
             {error, Reason}
     end.
 
-
+acc_modules([], _Command, Config, _File, Acc) ->
+    {Config, Acc};
+acc_modules([Module | Rest], Command, Config, File, Acc) ->
+    case Module:Command(Config, File) of
+        {ok, NewConfig, Result} when is_list(Result) ->
+            List = Result;
+        {ok, NewConfig, Result} ->
+            List = [Result]
+    end,
+    acc_modules(Rest, Command, NewConfig, File, List ++ Acc).

src/rebar_subdirs.erl

@@ -0,0 +1,44 @@
+%% -------------------------------------------------------------------
+%%
+%% rebar: Erlang Build Tools
+%%
+%% Copyright (c) 2009 Dave Smith (dizzyd@dizzyd.com)
+%%
+%% Permission is hereby granted, free of charge, to any person obtaining a copy
+%% of this software and associated documentation files (the "Software"), to deal
+%% in the Software without restriction, including without limitation the rights
+%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+%% copies of the Software, and to permit persons to whom the Software is
+%% furnished to do so, subject to the following conditions:
+%%
+%% The above copyright notice and this permission notice shall be included in
+%% all copies or substantial portions of the Software.
+%%
+%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+%% THE SOFTWARE.
+%% -------------------------------------------------------------------
+-module(rebar_subdirs).
+
+-include("rebar.hrl").
+
+-export([preprocess/2]).
+
+%% ===================================================================
+%% Public API
+%% ===================================================================
+
+preprocess(Config, _) ->
+    %% Get the list of subdirs specified in the config (if any).
+    Cwd = rebar_utils:get_cwd(),
+    Subdirs = [filename:join(Cwd, Dir) || Dir <- rebar_config:get(Config, sub_dirs, [])],
+
+    %% Filter out the subdirs from the config so that processing in the
+    %% subdirs doesn't try to reprocess
+    Config2 = rebar_config:delete(Config, sub_dirs),
+    {ok, Config2, Subdirs}.
+