check last modified time on erl files for xrl and yrl files before compiling

5 files changed, 25 insertions, 12 deletions

diff --git a/src/rebar_compiler.erl b/src/rebar_compiler.erl
index 6e94cb2..256794a 100644
--- a/src/rebar_compiler.erl
+++ b/src/rebar_compiler.erl
@@ -3,6 +3,7 @@
 -export([compile_all/2,
          clean/2,
 
+         needs_compile/3,
          ok_tuple/2,
          error_tuple/4,
          maybe_report/1,
@@ -18,7 +19,7 @@
                                            include_dirs => [file:dirname()],
                                            src_ext      => extension(),
                                            out_mappings => out_mappings()}.
--callback needed_files(digraph:graph(), [file:filename()], rebar_app_info:t()) -> [file:filename()].
+-callback needed_files(digraph:graph(), [file:filename()], list(), rebar_app_info:t()) -> [file:filename()].
 -callback dependencies(file:filename(), file:dirname(), [file:dirname()]) -> [file:filename()].
 -callback compile(file:filename(), out_mappings(), rebar_dict(), list()) ->
     ok | {ok, [string()]} | {ok, [string()], [string()]}.
@@ -66,7 +67,8 @@ run(CompilerMod, AppInfo) ->
     OutDir = rebar_app_info:out_dir(AppInfo),
     AbsSrcDirs = [filename:join(BaseDir, SrcDir) || SrcDir <- SrcDirs],
     G = init_dag(CompilerMod, AbsInclDirs, AbsSrcDirs, FoundFiles, OutDir, EbinDir),
-    {{FirstFiles, FirstFileOpts}, {RestFiles, Opts}} = CompilerMod:needed_files(G, FoundFiles, AppInfo),
+    {{FirstFiles, FirstFileOpts}, {RestFiles, Opts}} = CompilerMod:needed_files(G, FoundFiles,
+                                                                                Mappings, AppInfo),
     true = digraph:delete(G),
 
     compile_each(FirstFiles, FirstFileOpts, BaseOpts, Mappings, CompilerMod),
@@ -111,6 +113,13 @@ clean_(CompilerMod, AppInfo) ->
     CompilerMod:clean(FoundFiles, AppInfo),
     rebar_file_utils:rm_rf(dag_file(CompilerMod, EbinDir)).
 
+-spec needs_compile(filename:all(), extension(), [{extension(), file:dirname()}]) -> boolean().
+needs_compile(Source, OutExt, Mappings) ->
+    Ext = filename:extension(Source),
+    BaseName = filename:basename(Source, Ext),
+    {_, OutDir} = lists:keyfind(OutExt, 1, Mappings),
+    Target = filename:join(OutDir, BaseName++OutExt),
+    filelib:last_modified(Source) > filelib:last_modified(Target).
 
 run_on_extra_src_dirs(CompilerMod, AppInfo, Fun) ->
     ExtraDirs = rebar_dir:extra_src_dirs(rebar_app_info:opts(AppInfo), []),
diff --git a/src/rebar_compiler_erl.erl b/src/rebar_compiler_erl.erl
index d9bc69b..f0ae6f4 100644
--- a/src/rebar_compiler_erl.erl
+++ b/src/rebar_compiler_erl.erl
@@ -3,7 +3,7 @@
 -behaviour(rebar_compiler).
 
 -export([context/1,
-         needed_files/3,
+         needed_files/4,
          dependencies/3,
          compile/4,
          clean/2]).
@@ -31,7 +31,7 @@ context(AppInfo) ->
       out_mappings => Mappings}.
 
 
-needed_files(Graph, FoundFiles, AppInfo) ->
+needed_files(Graph, FoundFiles, _, AppInfo) ->
     OutDir = rebar_app_info:out_dir(AppInfo),
     Dir = rebar_app_info:dir(AppInfo),
     EbinDir = rebar_app_info:ebin_dir(AppInfo),
diff --git a/src/rebar_compiler_mib.erl b/src/rebar_compiler_mib.erl
index 32516bf..c731c27 100644
--- a/src/rebar_compiler_mib.erl
+++ b/src/rebar_compiler_mib.erl
@@ -3,7 +3,7 @@
 -behaviour(rebar_compiler).
 
 -export([context/1,
-         needed_files/3,
+         needed_files/4,
          dependencies/3,
          compile/4,
          clean/2]).
@@ -21,7 +21,7 @@ context(AppInfo) ->
       src_ext => ".mib",
       out_mappings => Mappings}.
 
-needed_files(_, FoundFiles, AppInfo) ->
+needed_files(_, FoundFiles, _, AppInfo) ->
     FirstFiles = [],
 
     %% Remove first files from found files
diff --git a/src/rebar_compiler_xrl.erl b/src/rebar_compiler_xrl.erl
index 5c023f0..23ed1eb 100644
--- a/src/rebar_compiler_xrl.erl
+++ b/src/rebar_compiler_xrl.erl
@@ -3,7 +3,7 @@
 -behaviour(rebar_compiler).
 
 -export([context/1,
-         needed_files/3,
+         needed_files/4,
          dependencies/3,
          compile/4,
          clean/2]).
@@ -16,11 +16,13 @@ context(AppInfo) ->
       src_ext => ".xrl",
       out_mappings => Mappings}.
 
-needed_files(_, FoundFiles, AppInfo) ->
+needed_files(_, FoundFiles, Mappings, AppInfo) ->
     FirstFiles = [],
 
     %% Remove first files from found files
-    RestFiles = [Source || Source <- FoundFiles, not lists:member(Source, FirstFiles)],
+    RestFiles = [Source || Source <- FoundFiles,
+                           not lists:member(Source, FirstFiles),
+                           rebar_compiler:needs_compile(Source, ".erl", Mappings)],
 
     Opts = rebar_opts:get(rebar_app_info:opts(AppInfo), xrl_opts, []),
 
diff --git a/src/rebar_compiler_yrl.erl b/src/rebar_compiler_yrl.erl
index 41d93b1..9c1767e 100644
--- a/src/rebar_compiler_yrl.erl
+++ b/src/rebar_compiler_yrl.erl
@@ -3,7 +3,7 @@
 -behaviour(rebar_compiler).
 
 -export([context/1,
-         needed_files/3,
+         needed_files/4,
          dependencies/3,
          compile/4,
          clean/2]).
@@ -16,11 +16,13 @@ context(AppInfo) ->
       src_ext => ".yrl",
       out_mappings => Mappings}.
 
-needed_files(_, FoundFiles, AppInfo) ->
+needed_files(_, FoundFiles, Mappings, AppInfo) ->
     FirstFiles = [],
 
     %% Remove first files from found files
-    RestFiles = [Source || Source <- FoundFiles, not lists:member(Source, FirstFiles)],
+    RestFiles = [Source || Source <- FoundFiles,
+                           not lists:member(Source, FirstFiles),
+                           rebar_compiler:needs_compile(Source, ".erl", Mappings)],
 
     Opts = rebar_opts:get(rebar_app_info:opts(AppInfo), yrl_opts, []),
     {{FirstFiles, Opts}, {RestFiles, Opts}}.