Add abnfc support

abnfc is an ABNF parser generator.
Options are:
	- doc_root (defaults to "src")
	- out_dir (defaults to "src")
	- source_ext (defaults to ".abnf")
	- module_ext (defaults to "")

ebin/rebar.app

@@ -2,6 +2,7 @@
  [{description, "Rebar: Erlang Build Tool"},
   {vsn, "2"},
   {modules, [ rebar,
+              rebar_abnfc_compiler,
               rebar_app_utils,
               rebar_base_compiler,
               rebar_config,
@@ -59,6 +60,7 @@
          {modules, [
                     {app_dir, [
                                rebar_pre_script,
+                               rebar_abnfc_compiler,
                                rebar_protobuffs_compiler,
                                rebar_neotoma_compiler,
                                rebar_asn1_compiler,

src/rebar_abnfc_compiler.erl

@@ -0,0 +1,109 @@
+%% -*- tab-width: 4;erlang-indent-level: 4;indent-tabs-mode: nil -*-
+%% ex: ts=4 sw=4 et
+%% -------------------------------------------------------------------
+%%
+%% rebar: Erlang Build Tools
+%%
+%% Copyright (c) 2010 Anthony Ramine (nox@dev-extend.eu),
+%%
+%% 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.
+%% -------------------------------------------------------------------
+
+%% The rebar_abnfc_compiler module is a plugin for rebar that compiles
+%% ABNF grammars into parsers.  By default, it compiles all src/*.abnf
+%% to src/*.erl.
+%%
+%% Configuration options should be placed in rebar.config under
+%% 'abnfc_opts'.  Available options include:
+%%
+%%  doc_root: where to find the ABNF grammars to compile
+%%            "src" by default
+%%
+%%  out_dir: where to put the generated files.
+%%           "src" by default
+%%
+%%  source_ext: the file extension the ABNF grammars have.
+%%              ".abnf" by default
+%%
+%%  module_ext: characters to append to the parser's module name
+%%              "" by default
+-module(rebar_abnfc_compiler).
+
+-export([compile/2]).
+
+-include("rebar.hrl").
+
+%% ===================================================================
+%% Public API
+%% ===================================================================
+
+compile(Config, _AppFile) ->
+    DtlOpts = abnfc_opts(Config),
+    rebar_base_compiler:run(Config, [],
+                            option(doc_root, DtlOpts),
+                            option(source_ext, DtlOpts),
+                            option(out_dir, DtlOpts),
+                            option(module_ext, DtlOpts) ++ ".erl",
+                            fun compile_abnfc/3).
+
+
+%% ===================================================================
+%% Internal functions
+%% ===================================================================
+
+abnfc_opts(Config) ->
+    rebar_config:get(Config, abnfc_opts, []).
+
+option(Opt, DtlOpts) ->
+    proplists:get_value(Opt, DtlOpts, default(Opt)).
+
+default(doc_root) -> "src";
+default(out_dir)  -> "src";
+default(source_ext) -> ".abnf";
+default(module_ext) -> "".
+
+abnfc_is_present() ->
+    code:which(abnfc) =/= non_existing.
+
+compile_abnfc(Source, _Target, Config) ->
+    case abnfc_is_present() of
+        false ->
+            ?CONSOLE(
+               "~n===============================================~n"
+               " You need to install abnfc to compile ABNF grammars~n"
+               " Download the latest tarball release from github~n"
+               "    https://github.com/nygge/abnfc~n"
+               " and install it into your erlang library dir~n"
+               "===============================================~n~n", []),
+            ?FAIL;
+        true ->
+            AbnfcOpts = abnfc_opts(Config),
+            SourceExt = option(source_ext, AbnfcOpts),
+            Opts = [noobj,
+                    {o, option(out_dir, AbnfcOpts)},
+                    {mod, filename:basename(Source, SourceExt) ++
+                          option(module_ext, AbnfcOpts)}],
+            case abnfc:file(Source, Opts) of
+                ok -> ok;
+                Error ->
+                    ?CONSOLE("Compiling grammar ~s failed:~n  ~p~n",
+                             [Source, Error]),
+                    ?FAIL
+            end
+    end.