-/// The compiler code necessary to support the cfg! extension, which expands to
-/// a literal `true` or `false` based on whether the given cfg matches the
-/// current compilation environment.
-use errors::DiagnosticBuilder;
+//! The compiler code necessary to support the cfg! extension, which expands to
+//! a literal `true` or `false` based on whether the given cfg matches the
+//! current compilation environment.
+use rustc_errors::DiagnosticBuilder;
use rustc_expand::base::{self, *};
use rustc_span::Span;
use syntax::ast;