You can implement this without compiler support in 2.10.0 with a macro.
scala> import language.experimental.macros, reflect.macros.Context
scala> def __FILE__impl(c: Context) = c.literal(c.macroApplication.pos.source.toString)
__FILE__impl: (c: scala.reflect.macros.Context)c.Expr[String]
scala> def __FILE__ = macro __FILE__impl
res1: String = <console>
scala> def __LINE__impl(c: Context) = c.literal(c.macroApplication.pos.line)
__LINE__impl: (c: scala.reflect.macros.Context)c.Expr[Int]
scala> def __LINE__ = macro __LINE__impl
res2: Int = 17
There has been a proposal to standardize an extension of this, Source Locations, which would allow you to implicitly pass the source location from a call site to some method.
That effort was put on hold as it was shows that even this can now be done as a macro. But we haven't moved that out of a prototype.