def source_to_dep(src, source_dir, dep_dir)
      exts = '\\' + @tc.source_extensions.join('|\\')
      src.sub(/(#{exts})$/, '.d').gsub(source_dir, dep_dir)
    end
def source_to_dep(src, source_dir, dep_dir)
      exts = '\\' + @tc.source_extensions.join('|\\')
      src.sub(/(#{exts})$/, '.d').gsub(source_dir, dep_dir)
    end
Transforms a source file name in to its dependency file name by replacing
 file name extension and the source directory base with the build directory base

 @param [String] src         Source filename
 @param [String] source_dir  Project source base directory
 @param [String] dep_dir     Project dependency base directory
 @return [String]            Mapped filename