Add rebar_pre_script courtesy of Geoff Cant

THANKS

@@ -21,4 +21,5 @@ Vagabond
 Russell Brown
 Chris Chew
 Klas Johansson
+Geoff Cant
 

ebin/rebar.app

@@ -25,6 +25,7 @@
               rebar_neotoma_compiler,
               rebar_port_compiler,
               rebar_post_script,
+              rebar_pre_script,
               rebar_rel_utils,
               rebar_reltool,
               rebar_require_vsn,
@@ -71,7 +72,8 @@
                                rebar_escripter,
                                rebar_edoc,
                                rebar_xref,
-                               rebar_post_script
+                               rebar_post_script,
+                               rebar_pre_script
                               ]},
 
                     {rel_dir, [

src/rebar_pre_script.erl

@@ -0,0 +1,55 @@
+%% -*- tab-width: 4;erlang-indent-level: 4;indent-tabs-mode: nil -*-
+%% ex: ts=4 sw=4 et
+%% -------------------------------------------------------------------
+%%
+%% rebar: Erlang Build Tools
+%%
+%% Copyright (c) 2009, 2010 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_pre_script).
+
+-export([compile/2,
+         clean/2]).
+
+-include("rebar.hrl").
+
+%% ===================================================================
+%% Public API
+%% ===================================================================
+
+compile(Config, _) ->
+    execute_pre_script(Config, compile_pre_script).
+
+clean(Config, _) ->
+    execute_pre_script(Config, clean_pre_script).
+
+
+%% ===================================================================
+%% Internal functions
+%% ===================================================================
+
+execute_pre_script(Config, Key) ->
+    case rebar_config:get(Config, Key, undefined) of
+        undefined ->
+            ok;
+        Script ->
+            rebar_utils:sh(Script, [])
+    end.