use relative path on non-windows and copy if link fails

src/rebar_dir.erl

@@ -15,7 +15,8 @@
          template_globals/1,
          template_dir/1,
          processing_base_dir/1,
-         processing_base_dir/2]).
+         processing_base_dir/2,
+         make_relative_path/2]).
 
 -include("rebar.hrl").
 
@@ -86,3 +87,12 @@ processing_base_dir(State) ->
 processing_base_dir(State, Dir) ->
     AbsDir = filename:absname(Dir),
     AbsDir =:= rebar_state:get(State, base_dir).
+
+make_relative_path(Source, Target) ->
+    do_make_relative_path(filename:split(Source), filename:split(Target)).
+
+do_make_relative_path([H|T1], [H|T2]) ->
+    do_make_relative_path(T1, T2);
+do_make_relative_path(Source, Target) ->
+    Base = lists:duplicate(max(length(Target) - 1, 0), ".."),
+    filename:join(Base ++ Source).

src/rebar_file_utils.erl

@@ -26,7 +26,8 @@
 %% -------------------------------------------------------------------
 -module(rebar_file_utils).
 
--export([rm_rf/1,
+-export([symlink_or_copy/2,
+         rm_rf/1,
          cp_r/2,
          mv/2,
          delete_each/1,
@@ -41,6 +42,22 @@
 %% Public API
 %% ===================================================================
 
+symlink_or_copy(Source, Target) ->
+    Link = case os:type() of
+               {win32, _} ->
+                   Source;
+               _ ->
+                   rebar_dir:make_relative_path(Source, Target)
+           end,
+    case file:make_symlink(Link, Target) of
+        ok ->
+            ok;
+        {error, eexist} ->
+            ok;
+        {error, _} ->
+            cp_r([Source], Target)
+    end.
+
 %% @doc Remove files and directories.
 %% Target is a single filename, directoryname or wildcard expression.
 -spec rm_rf(string()) -> 'ok'.
@@ -127,7 +144,7 @@ write_file_if_contents_differ(Filename, Bytes) ->
     end.
 
 %% returns an os appropriate tmpdir given a path
--spec system_tmpdir() -> file:filename(). 
+-spec system_tmpdir() -> file:filename().
 -spec system_tmpdir(PathComponents) -> file:filename() when
       PathComponents :: [file:name()].
 

src/rebar_prv_compile.erl

@@ -123,8 +123,12 @@ copy_app_dirs(AppName, OldAppDir, AppDir) ->
             end,
             filelib:ensure_dir(filename:join(AppDir, "dummy")),
             %% link to src to be adjacent to ebin is needed for R15 use of cover/xref
-            [file:make_symlink(filename:join(OldAppDir, Dir), filename:join(AppDir, Dir))
-            || Dir <- ["priv", "include", "src"]];
+            [symlink_or_copy(OldAppDir, AppDir, Dir) || Dir <- ["priv", "include", "src"]];
         false ->
             ok
     end.
+
+symlink_or_copy(OldAppDir, AppDir, Dir) ->
+    Source = filename:join(OldAppDir, Dir),
+    Target = filename:join(AppDir, Dir),
+    rebar_file_utils:symlink_or_copy(Source, Target).