Added a compiler plugin for neotoma grammars

1 files changed, 139 insertions, 0 deletions

diff --git a/src/rebar_neotoma_compiler.erl b/src/rebar_neotoma_compiler.erl
new file mode 100644
index 0000000..9b50bf4
--- /dev/null
+++ b/src/rebar_neotoma_compiler.erl
@@ -0,0 +1,139 @@
+%% -*- tab-width: 4;erlang-indent-level: 4;indent-tabs-mode: nil -*-
+%% ex: ts=4 sw=4 et
+%% -------------------------------------------------------------------
+%%
+%% rebar: Erlang Build Tools
+%%
+%% Copyright (c) 2010 Cliff Moon (cliff@moonpolysoft.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.
+%% -------------------------------------------------------------------
+
+%% The rebar_neotoma module is a plugin for rebar that compiles
+%% neotoma peg files.  By default, it compiles all src/*.peg to src/*.erl
+%% 
+%% Configuration options should be placed in rebar.config under
+%% neotoma_opts.  Available options include:
+%%
+%% doc_root: where to find the peg files to compile.
+%%           "src" by default
+%% out_dir: where to put the generated erl files.
+%%          "src" by defualt
+%% module_ext: characters to append to the module's name.
+%%             "" by default
+-module(rebar_neotoma_compiler).
+
+-export([compile/2]).
+
+-include("rebar.hrl").
+
+%% ============================================================================
+%% Public API
+%% ============================================================================
+
+compile(Config, _AppFile) ->
+  NeoOpts = neotoma_opts(Config),
+  rebar_base_compiler:run(Config, [],
+                          option(doc_root, NeoOpts), ".peg",
+                          option(out_dir, NeoOpts), option(module_ext, NeoOpts) ++ ".beam",
+                          fun compile_neo/3, [{check_last_mod,false}]).
+                            
+%% ============================================================================
+%% Public API
+%% ============================================================================
+
+neotoma_opts(Config) ->
+  rebar_config:get(Config, neotoma_opts, []).
+
+option(Opt, Options) ->
+  proplists:get_value(Opt, Options, default(Opt)).
+
+default(doc_root) -> "src";
+default(out_dir) -> "src";
+default(module_ext) -> "".
+
+compile_neo(Source, Target, Config) ->
+  case code:which(neotoma) of
+    non_existing ->
+      ?CONSOLE(
+         "~n===============================================~n"
+         " You need to install neotoma to compile PEG grammars~n"
+         " Download the latest tarball release from github~n"
+         "    http://github.com/seancribbs/neotoma~n"
+         " and install it into your erlang library dir~n"
+         "===============================================~n~n", []),
+      ?FAIL;
+    _ ->
+        case needs_compile(Source, Target, Config) of
+            true ->
+                do_compile(Source, Target, Config);
+            false ->
+                skipped
+        end
+  end.
+  
+do_compile(Source, _Target, Config) ->
+    %% TODO: Check last mod on target and referenced DTLs here..
+    NeoOpts = neotoma_opts(Config),
+    %% ensure that doc_root and out_dir are defined,
+    %% using defaults if necessary
+    Opts = [{output, option(out_dir, NeoOpts)},
+            {module, list_to_atom(filename:basename(Source, ".peg") ++ option(module_ext, NeoOpts))}],
+    case neotoma:file(Source, Opts ++ NeoOpts) of
+        ok -> 
+          ok;
+        Reason ->
+            ?CONSOLE("Compiling peg ~s failed:~n  ~p~n",
+                     [Source, Reason]),
+            ?FAIL
+    end.
+  
+needs_compile(Source, Target, Config) ->
+    LM = filelib:last_modified(Target),
+    case LM < filelib:last_modified(Source) of
+        true  -> true;
+        false ->
+            lists:any(fun(D) -> LM < filelib:last_modified(D) end,
+                      referenced_pegs(Source, Config))
+    end.
+    
+referenced_pegs(Source, Config) ->
+    Set = referenced_pegs1([Source], Config,
+                          sets:add_element(Source, sets:new())),
+    Final = sets:to_list(sets:del_element(Source, Set)),
+    Final.
+
+referenced_pegs1(Step, Config, Seen) ->
+    NeoOpts = neotoma_opts(Config),
+    ExtMatch = re:replace(option(source_ext, NeoOpts), "\.", "\\\\\\\\.",
+                          [{return, list}]),
+    AllRefs = lists:append(
+                [ string:tokens(
+                    os:cmd(["grep -o [^\\\"]*",ExtMatch," ",F]),
+                    "\n")
+                  || F <- Step]),
+    DocRoot = option(doc_root, NeoOpts),
+    WithPaths = [ filename:join([DocRoot, F]) || F <- AllRefs ],
+    Existing = lists:filter(fun filelib:is_file/1, WithPaths),
+    New = sets:subtract(sets:from_list(Existing), Seen),
+    case sets:size(New) of
+        0 -> Seen;
+        _ -> referenced_pegs1(sets:to_list(New), Config,
+                              sets:union(New, Seen))
+    end.
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