Remove unused extern crate directives

Author: Xanewok

src/bin/cargo_semver.rs

@@ -2,18 +2,15 @@
 #![feature(set_stdio)]
 #![allow(clippy::too_many_lines)]
 
-extern crate curl;
-#[macro_use]
-extern crate serde;
 extern crate rustc_session;
-extern crate serde_json;
 
 use cargo::core::{Package, PackageId, Source, SourceId, Workspace};
 use cargo::sources::RegistrySource;
 use curl::easy::Easy;
 use log::debug;
 use rand::Rng;
 use rustc_session::getopts;
+use serde::Deserialize;
 use std::collections::HashSet;
 use std::{
     env,

src/bin/rust_semver_public.rs

@@ -2,7 +2,6 @@
 
 extern crate rustc_driver;
 extern crate rustc_interface;
-extern crate rustc_middle;
 extern crate rustc_span;
 
 use log::debug;

src/bin/rust_semverver.rs

@@ -1,10 +1,7 @@
 #![feature(rustc_private)]
 
 extern crate rustc_driver;
-extern crate rustc_errors;
 extern crate rustc_interface;
-extern crate rustc_metadata;
-extern crate rustc_middle;
 extern crate rustc_span;
 
 use log::debug;

src/changes.rs

@@ -1222,7 +1222,6 @@ impl<'a, 'tcx> Serialize for RChangeSet<'a, 'tcx> {
 #[cfg(test)]
 pub mod tests {
     pub use super::*;
-    extern crate quickcheck;
     use quickcheck::*;
 
     use rustc_hir::def_id::DefId;

src/lib.rs

@@ -4,15 +4,13 @@
 #![allow(clippy::too_many_lines)]
 #![deny(warnings)]
 
-extern crate rustc_ast;
 extern crate rustc_hir;
 extern crate rustc_infer;
 extern crate rustc_middle;
 extern crate rustc_mir;
 extern crate rustc_session;
 extern crate rustc_span;
 extern crate rustc_trait_selection;
-extern crate rustc_traits;
 
 mod changes;
 mod mapping;