Merge pull request #3189 from eddyb/rextern

Reintroduce `extern crate` for non-Cargo dependencies.

Author: oli-obk

Cargo.toml

@@ -1,3 +1,5 @@
+cargo-features = ["edition"]
+
 [package]
 name = "clippy"
 version = "0.0.212"

clippy_lints/Cargo.toml

@@ -1,3 +1,5 @@
+cargo-features = ["edition"]
+
 [package]
 name = "clippy_lints"
 # begin automatic update

clippy_lints/src/approx_const.rs

@@ -1,10 +1,10 @@
 use crate::utils::span_lint;
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
+use crate::rustc::hir::*;
+use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use crate::rustc::{declare_tool_lint, lint_array};
 use std::f64::consts as f64;
-use syntax::ast::{FloatTy, Lit, LitKind};
-use syntax::symbol;
+use crate::syntax::ast::{FloatTy, Lit, LitKind};
+use crate::syntax::symbol;
 
 /// **What it does:** Checks for floating point literals that approximate
 /// constants which are defined in

clippy_lints/src/arithmetic.rs

@@ -1,8 +1,8 @@
 use crate::utils::span_lint;
-use rustc::hir;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
-use syntax::source_map::Span;
+use crate::rustc::hir;
+use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use crate::rustc::{declare_tool_lint, lint_array};
+use crate::syntax::source_map::Span;
 
 /// **What it does:** Checks for plain integer arithmetic.
 ///

clippy_lints/src/assign_ops.rs

@@ -1,11 +1,11 @@
 use crate::utils::{get_trait_def_id, implements_trait, snippet_opt, span_lint_and_then, SpanlessEq};
 use crate::utils::{higher, sugg};
-use rustc::hir;
-use rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
+use crate::rustc::hir;
+use crate::rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
+use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use crate::rustc::{declare_tool_lint, lint_array};
 use if_chain::if_chain;
-use syntax::ast;
+use crate::syntax::ast;
 
 /// **What it does:** Checks for `a = a op b` or `a = b commutative_op a`
 /// patterns.
@@ -220,7 +220,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssignOps {
 }
 
 fn is_commutative(op: hir::BinOpKind) -> bool {
-    use rustc::hir::BinOpKind::*;
+    use crate::rustc::hir::BinOpKind::*;
     match op {
         Add | Mul | And | Or | BitXor | BitAnd | BitOr | Eq | Ne => true,
         Sub | Div | Rem | Shl | Shr | Lt | Le | Ge | Gt => false,

clippy_lints/src/attrs.rs

@@ -5,14 +5,14 @@ use crate::utils::{
     in_macro, last_line_of_span, match_def_path, opt_def_id, paths, snippet_opt, span_lint, span_lint_and_then,
     without_block_comments,
 };
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
+use crate::rustc::hir::*;
+use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use crate::rustc::{declare_tool_lint, lint_array};
 use if_chain::if_chain;
-use rustc::ty::{self, TyCtxt};
+use crate::rustc::ty::{self, TyCtxt};
 use semver::Version;
-use syntax::ast::{AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem, NestedMetaItemKind};
-use syntax::source_map::Span;
+use crate::syntax::ast::{AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem, NestedMetaItemKind};
+use crate::syntax::source_map::Span;
 
 /// **What it does:** Checks for items annotated with `#[inline(always)]`,
 /// unless the annotated function is empty or simply panics.
@@ -180,10 +180,15 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AttrPass {
                                                                 || is_word(lint, "deprecated") {
                                                 return
                                         },
-                                        ItemKind::ExternCrate(..) => if is_word(lint, "unused_imports")
-                                                                        && skip_unused_imports {
+                                        ItemKind::ExternCrate(..) => {
+                                            if is_word(lint, "unused_imports")
+                                                && skip_unused_imports {
+                                                    return
+                                            }
+                                            if is_word(lint, "unused_extern_crates") {
                                                 return
-                                        },
+                                            }
+                                        }
                                         _ => {},
                                     }
                                 }

clippy_lints/src/bit_mask.rs

@@ -1,9 +1,9 @@
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
+use crate::rustc::hir::*;
+use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use crate::rustc::{declare_tool_lint, lint_array};
 use if_chain::if_chain;
-use syntax::ast::LitKind;
-use syntax::source_map::Span;
+use crate::syntax::ast::LitKind;
+use crate::syntax::source_map::Span;
 use crate::utils::{span_lint, span_lint_and_then};
 use crate::utils::sugg::Sugg;
 use crate::consts::{constant, Constant};

clippy_lints/src/blacklisted_name.rs

@@ -1,6 +1,6 @@
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
-use rustc::hir::*;
+use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use crate::rustc::{declare_tool_lint, lint_array};
+use crate::rustc::hir::*;
 use crate::utils::span_lint;
 
 /// **What it does:** Checks for usage of blacklisted names for variables, such

clippy_lints/src/block_in_if_condition.rs

@@ -1,8 +1,8 @@
 use matches::matches;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
-use rustc::hir::*;
-use rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
+use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use crate::rustc::{declare_tool_lint, lint_array};
+use crate::rustc::hir::*;
+use crate::rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
 use crate::utils::*;
 
 /// **What it does:** Checks for `if` conditions that use blocks to contain an

clippy_lints/src/booleans.rs

@@ -1,10 +1,10 @@
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
-use rustc::hir::*;
-use rustc::hir::intravisit::*;
-use syntax::ast::{LitKind, NodeId, DUMMY_NODE_ID};
-use syntax::source_map::{dummy_spanned, Span, DUMMY_SP};
-use rustc_data_structures::thin_vec::ThinVec;
+use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use crate::rustc::{declare_tool_lint, lint_array};
+use crate::rustc::hir::*;
+use crate::rustc::hir::intravisit::*;
+use crate::syntax::ast::{LitKind, NodeId, DUMMY_NODE_ID};
+use crate::syntax::source_map::{dummy_spanned, Span, DUMMY_SP};
+use crate::rustc_data_structures::thin_vec::ThinVec;
 use crate::utils::{in_macro, paths, match_type, snippet_opt, span_lint_and_then, SpanlessEq, get_trait_def_id, implements_trait};
 
 /// **What it does:** Checks for boolean expressions that can be written more