Port rebar_file_utils to Windows

Modify rm_rf and cp_r to work when {win32,_} = os:type().
Simplify rm_rf to only accept one filename, directoryname or wildcard.
Add unit tests to ensure a similar behaviour on windows and unix.

Thanks to tuncer for guidance and feedback.

3 files changed, 76 insertions, 10 deletions

diff --git a/src/rebar_erlc_compiler.erl b/src/rebar_erlc_compiler.erl
index 50e890c..e872e2b 100644
--- a/src/rebar_erlc_compiler.erl
+++ b/src/rebar_erlc_compiler.erl
@@ -71,10 +71,8 @@ compile(Config, _AppFile) ->
 
 -spec clean(Config::#config{}, AppFile::string()) -> 'ok'.
 clean(_Config, _AppFile) ->
-    %% TODO: This would be more portable if it used Erlang to traverse
-    %%       the dir structure and delete each file; however it would also
-    %%       much slower.
-    ok = rebar_file_utils:rm_rf("ebin/*.beam priv/mibs/*.bin"),
+    lists:foreach(fun(F) -> ok = rebar_file_utils:rm_rf(F) end,
+                  ["ebin/*.beam", "priv/mibs/*.bin"]),
 
     YrlFiles = rebar_utils:find_files("src", "^.*\\.[x|y]rl\$"),
     rebar_file_utils:delete_each(
diff --git a/src/rebar_file_utils.erl b/src/rebar_file_utils.erl
index 429f478..1538fa8 100644
--- a/src/rebar_file_utils.erl
+++ b/src/rebar_file_utils.erl
@@ -36,14 +36,30 @@
 %% Public API
 %% ===================================================================
 
+%% @doc Remove files and directories.
+%% Target is a single filename, directoryname or wildcard expression.
+%% @spec rm_rf(string()) -> ok
+-spec rm_rf(Target::string()) -> ok.
 rm_rf(Target) ->
-    [] = os:cmd(?FMT("rm -rf ~s", [Target])),
-    ok.
+    case os:type() of
+        {unix,_} ->
+            [] = os:cmd(?FMT("rm -rf ~s", [Target])),
+            ok;
+        {win32,_} ->
+            ok = rm_rf_win32(Target)
+    end.
 
+-spec cp_r(Sources::list(string()), Dest::string()) -> ok.
 cp_r(Sources, Dest) ->
-    SourceStr = string:join(Sources, " "),
-    [] = os:cmd(?FMT("cp -R ~s ~s", [SourceStr, Dest])),
-    ok.
+    case os:type() of
+        {unix,_} ->
+            SourceStr = string:join(Sources, " "),
+            [] = os:cmd(?FMT("cp -R ~s ~s", [SourceStr, Dest])),
+            ok;
+        {win32,_} ->
+            lists:foreach(fun(Src) -> ok = cp_r_win32(Src,Dest) end, Sources),
+            ok
+    end.
 
 delete_each([]) ->
     ok;
@@ -58,3 +74,55 @@ delete_each([File | Rest]) ->
             ?FAIL
     end.
 
+%% ===================================================================
+%% Internal functions
+%% ===================================================================
+
+rm_rf_win32(Target) ->
+    Filelist = filelib:wildcard(Target),
+    Dirs = lists:filter(fun filelib:is_dir/1,Filelist),
+    Files = lists:subtract(Filelist,Dirs),
+    ok = delete_each(Files),
+    ok = delete_each_dir_win32(Dirs),
+    ok.
+
+delete_each_dir_win32([]) -> ok;
+delete_each_dir_win32([Dir | Rest]) ->
+    [] = os:cmd(?FMT("rd /q /s ~s", [filename:nativename(Dir)])),
+    delete_each_dir_win32(Rest).
+
+xcopy_win32(Source,Dest)->
+    R = os:cmd(?FMT("xcopy ~s ~s /q /y /e 2> nul",
+                    [filename:nativename(Source), filename:nativename(Dest)])),
+    case string:str(R,"\r\n") > 0 of
+        %% when xcopy fails, stdout is empty and and error message is printed
+        %% to stderr (which is redirected to nul)
+        true -> ok;
+        false ->
+            {error, lists:flatten(
+                      io_lib:format("Failed to xcopy from ~s to ~s\n",
+                                     [Source, Dest]))}
+    end.
+
+cp_r_win32({true,SourceDir},{true,DestDir}) ->
+    % from directory to directory
+    SourceBase = filename:basename(SourceDir),
+    ok = case file:make_dir(filename:join(DestDir,SourceBase)) of
+             {error,eexist} -> ok;
+             Other -> Other
+         end,
+    ok = xcopy_win32(SourceDir,filename:join(DestDir,SourceBase));
+cp_r_win32({false,Source},{true,DestDir}) ->
+    % from file to directory
+    cp_r_win32({false,Source},
+               {false,filename:join(DestDir,filename:basename(Source))});
+cp_r_win32({false,Source},{false,Dest}) ->
+    % from file to file
+    {ok,_} = file:copy(Source,Dest),
+    ok;
+cp_r_win32(Source,Dest) ->
+    Dst = {filelib:is_dir(Dest),Dest},
+    lists:foreach(fun(Src) ->
+                          ok = cp_r_win32({filelib:is_dir(Src),Src},Dst)
+                  end, filelib:wildcard(Source)),
+    ok.
diff --git a/src/rebar_reltool.erl b/src/rebar_reltool.erl
index 024870e..b8e1095 100644
--- a/src/rebar_reltool.erl
+++ b/src/rebar_reltool.erl
@@ -281,7 +281,7 @@ execute_overlay([{copy, In, Out} | Rest], Vars, BaseDir, TargetDir) ->
         false ->
             ok = filelib:ensure_dir(OutFile)
     end,
-    rebar_utils:sh(?FMT("cp -R ~p ~p", [InFile, OutFile]), []),
+    rebar_file_utils:cp_r([InFile], OutFile),
     execute_overlay(Rest, Vars, BaseDir, TargetDir);
 execute_overlay([{template, In, Out} | Rest], Vars, BaseDir, TargetDir) ->
     InFile = render(filename:join(BaseDir, In), Vars),