Merging master

7 files changed, 47 insertions, 56 deletions

diff --git a/src/librustc_errors/Cargo.toml b/src/librustc_errors/Cargo.toml
index b24f8ddf4d9..02c011857bd 100644
--- a/src/librustc_errors/Cargo.toml
+++ b/src/librustc_errors/Cargo.toml
@@ -2,6 +2,7 @@
 authors = ["The Rust Project Developers"]
 name = "rustc_errors"
 version = "0.0.0"
+edition = "2018"
 
 [lib]
 name = "rustc_errors"
diff --git a/src/librustc_errors/diagnostic.rs b/src/librustc_errors/diagnostic.rs
index 06a1761a1e7..2c410f69bfc 100644
--- a/src/librustc_errors/diagnostic.rs
+++ b/src/librustc_errors/diagnostic.rs
@@ -1,11 +1,11 @@
-use CodeSuggestion;
-use SubstitutionPart;
-use Substitution;
-use Applicability;
-use Level;
+use crate::CodeSuggestion;
+use crate::SubstitutionPart;
+use crate::Substitution;
+use crate::Applicability;
+use crate::Level;
+use crate::snippet::Style;
 use std::fmt;
 use syntax_pos::{MultiSpan, Span};
-use snippet::Style;
 
 #[must_use]
 #[derive(Clone, Debug, PartialEq, Hash, RustcEncodable, RustcDecodable)]
@@ -118,7 +118,7 @@ impl Diagnostic {
         self.level == Level::Cancelled
     }
 
-    /// Add a span/label to be included in the resulting snippet.
+    /// Adds a span/label to be included in the resulting snippet.
     /// This is pushed onto the `MultiSpan` that was created when the
     /// diagnostic was first built. If you don't call this function at
     /// all, and you just supplied a `Span` to create the diagnostic,
diff --git a/src/librustc_errors/diagnostic_builder.rs b/src/librustc_errors/diagnostic_builder.rs
index f423a4cd1a7..9d5e8d10b17 100644
--- a/src/librustc_errors/diagnostic_builder.rs
+++ b/src/librustc_errors/diagnostic_builder.rs
@@ -1,14 +1,15 @@
-use Diagnostic;
-use DiagnosticId;
-use DiagnosticStyledString;
-use Applicability;
+use crate::Diagnostic;
+use crate::DiagnosticId;
+use crate::DiagnosticStyledString;
+use crate::Applicability;
 
-use Level;
-use Handler;
+use crate::Level;
+use crate::Handler;
 use std::fmt::{self, Debug};
 use std::ops::{Deref, DerefMut};
 use std::thread::panicking;
 use syntax_pos::{MultiSpan, Span};
+use log::debug;
 
 /// Used for emitting structured error messages and other diagnostic information.
 ///
@@ -25,7 +26,7 @@ pub struct DiagnosticBuilder<'a> {
 
 /// In general, the `DiagnosticBuilder` uses deref to allow access to
 /// the fields and methods of the embedded `diagnostic` in a
-/// transparent way.  *However,* many of the methods are intended to
+/// transparent way. *However,* many of the methods are intended to
 /// be used in a chained way, and hence ought to return `self`. In
 /// that case, we can't just naively forward to the method on the
 /// `diagnostic`, because the return type would be a `&Diagnostic`
@@ -111,8 +112,8 @@ impl<'a> DiagnosticBuilder<'a> {
         // implements `Drop`.
         let diagnostic;
         unsafe {
-            diagnostic = ::std::ptr::read(&self.diagnostic);
-            ::std::mem::forget(self);
+            diagnostic = std::ptr::read(&self.diagnostic);
+            std::mem::forget(self);
         };
         // Logging here is useful to help track down where in logs an error was
         // actually emitted.
@@ -149,7 +150,7 @@ impl<'a> DiagnosticBuilder<'a> {
         self.cancel();
     }
 
-    /// Add a span/label to be included in the resulting snippet.
+    /// Adds a span/label to be included in the resulting snippet.
     /// This is pushed onto the `MultiSpan` that was created when the
     /// diagnostic was first built. If you don't call this function at
     /// all, and you just supplied a `Span` to create the diagnostic,
@@ -298,7 +299,7 @@ impl<'a> DiagnosticBuilder<'a> {
 }
 
 impl<'a> Debug for DiagnosticBuilder<'a> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         self.diagnostic.fmt(f)
     }
 }
diff --git a/src/librustc_errors/emitter.rs b/src/librustc_errors/emitter.rs
index 25d09a33c15..1c0c9d137e4 100644
--- a/src/librustc_errors/emitter.rs
+++ b/src/librustc_errors/emitter.rs
@@ -1,37 +1,35 @@
-use self::Destination::*;
+use Destination::*;
 
 use syntax_pos::{SourceFile, Span, MultiSpan};
 
-use {Level, CodeSuggestion, DiagnosticBuilder, SubDiagnostic, SourceMapperDyn, DiagnosticId};
-use snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, StyledString, Style};
-use styled_buffer::StyledBuffer;
+use crate::{Level, CodeSuggestion, DiagnosticBuilder, SubDiagnostic, SourceMapperDyn, DiagnosticId};
+use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, StyledString, Style};
+use crate::styled_buffer::StyledBuffer;
 
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lrc;
-use atty;
 use std::borrow::Cow;
 use std::io::prelude::*;
 use std::io;
 use std::cmp::{min, Reverse};
 use termcolor::{StandardStream, ColorChoice, ColorSpec, BufferWriter};
 use termcolor::{WriteColor, Color, Buffer};
-use unicode_width;
 
 const ANONYMIZED_LINE_NUM: &str = "LL";
 
 /// Emitter trait for emitting errors.
 pub trait Emitter {
     /// Emit a structured diagnostic.
-    fn emit(&mut self, db: &DiagnosticBuilder);
+    fn emit(&mut self, db: &DiagnosticBuilder<'_>);
 
-    /// Check if should show explanations about "rustc --explain"
+    /// Checks if should show explanations about "rustc --explain"
     fn should_show_explain(&self) -> bool {
         true
     }
 }
 
 impl Emitter for EmitterWriter {
-    fn emit(&mut self, db: &DiagnosticBuilder) {
+    fn emit(&mut self, db: &DiagnosticBuilder<'_>) {
         let mut primary_span = db.span.clone();
         let mut children = db.children.clone();
         let mut suggestions: &[_] = &[];
@@ -674,8 +672,8 @@ impl EmitterWriter {
         //   | |  something about `foo`
         //   | something about `fn foo()`
         annotations_position.sort_by(|a, b| {
-            // Decreasing order
-            a.1.len().cmp(&b.1.len()).reverse()
+            // Decreasing order. When `a` and `b` are the same length, prefer `Primary`.
+            (a.1.len(), !a.1.is_primary).cmp(&(b.1.len(), !b.1.is_primary)).reverse()
         });
 
         // Write the underlines.
@@ -870,7 +868,7 @@ impl EmitterWriter {
         }
     }
 
-    /// Add a left margin to every line but the first, given a padding length and the label being
+    /// Adds a left margin to every line but the first, given a padding length and the label being
     /// displayed, keeping the provided highlighting.
     fn msg_to_buffer(&self,
                      buffer: &mut StyledBuffer,
@@ -897,7 +895,7 @@ impl EmitterWriter {
         //    `max_line_num_len`
         let padding = " ".repeat(padding + label.len() + 5);
 
-        /// Return whether `style`, or the override if present and the style is `NoStyle`.
+        /// Returns `true` if `style`, or the override if present and the style is `NoStyle`.
         fn style_or_override(style: Style, override_style: Option<Style>) -> Style {
             if let Some(o) = override_style {
                 if style == Style::NoStyle {
@@ -1431,7 +1429,7 @@ fn emit_to_destination(rendered_buffer: &[Vec<StyledString>],
                        dst: &mut Destination,
                        short_message: bool)
                        -> io::Result<()> {
-    use lock;
+    use crate::lock;
 
     let mut dst = dst.writable();
 
diff --git a/src/librustc_errors/lib.rs b/src/librustc_errors/lib.rs
index 64d5ca0c2a7..93d33d99361 100644
--- a/src/librustc_errors/lib.rs
+++ b/src/librustc_errors/lib.rs
@@ -1,6 +1,4 @@
-#![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
-      html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
-      html_root_url = "https://doc.rust-lang.org/nightly/")]
+#![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
 
 #![feature(custom_attribute)]
 #![allow(unused_attributes)]
@@ -8,21 +6,14 @@
 #![cfg_attr(unix, feature(libc))]
 #![feature(nll)]
 #![feature(optin_builtin_traits)]
+#![deny(rust_2018_idioms)]
 
-extern crate atty;
-extern crate termcolor;
-#[cfg(unix)]
-extern crate libc;
-#[macro_use]
-extern crate log;
-extern crate rustc_data_structures;
-extern crate serialize as rustc_serialize;
-extern crate syntax_pos;
-extern crate unicode_width;
+#[allow(unused_extern_crates)]
+extern crate serialize as rustc_serialize; // used by deriving
 
 pub use emitter::ColorConfig;
 
-use self::Level::*;
+use Level::*;
 
 use emitter::{Emitter, EmitterWriter};
 
@@ -144,7 +135,7 @@ impl CodeSuggestion {
         use syntax_pos::{CharPos, Loc, Pos};
 
         fn push_trailing(buf: &mut String,
-                         line_opt: Option<&Cow<str>>,
+                         line_opt: Option<&Cow<'_, str>>,
                          lo: &Loc,
                          hi_opt: Option<&Loc>) {
             let (lo, hi_opt) = (lo.col.to_usize(), hi_opt.map(|hi| hi.col.to_usize()));
@@ -247,7 +238,7 @@ impl FatalError {
 }
 
 impl fmt::Display for FatalError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "parser fatal error")
     }
 }
@@ -264,7 +255,7 @@ impl error::Error for FatalError {
 pub struct ExplicitBug;
 
 impl fmt::Display for ExplicitBug {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "parser internal bug")
     }
 }
@@ -399,7 +390,7 @@ impl Handler {
 
     /// Resets the diagnostic error count as well as the cached emitted diagnostics.
     ///
-    /// NOTE: DO NOT call this function from rustc. It is only meant to be called from external
+    /// NOTE: *do not* call this function from rustc. It is only meant to be called from external
     /// tools that want to reuse a `Parser` cleaning the previously emitted diagnostics as well as
     /// the overall count of emitted error diagnostics.
     pub fn reset_err_count(&self) {
@@ -496,7 +487,7 @@ impl Handler {
         DiagnosticBuilder::new(self, Level::Fatal, msg)
     }
 
-    pub fn cancel(&self, err: &mut DiagnosticBuilder) {
+    pub fn cancel(&self, err: &mut DiagnosticBuilder<'_>) {
         err.cancel();
     }
 
@@ -698,12 +689,12 @@ impl Handler {
         self.taught_diagnostics.borrow_mut().insert(code.clone())
     }
 
-    pub fn force_print_db(&self, mut db: DiagnosticBuilder) {
+    pub fn force_print_db(&self, mut db: DiagnosticBuilder<'_>) {
         self.emitter.borrow_mut().emit(&db);
         db.cancel();
     }
 
-    fn emit_db(&self, db: &DiagnosticBuilder) {
+    fn emit_db(&self, db: &DiagnosticBuilder<'_>) {
         let diagnostic = &**db;
 
         TRACK_DIAGNOSTICS.with(|track_diagnostics| {
@@ -749,7 +740,7 @@ pub enum Level {
 }
 
 impl fmt::Display for Level {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         self.to_str().fmt(f)
     }
 }
diff --git a/src/librustc_errors/snippet.rs b/src/librustc_errors/snippet.rs
index da1da77f398..0c62ff0ff89 100644
--- a/src/librustc_errors/snippet.rs
+++ b/src/librustc_errors/snippet.rs
@@ -1,6 +1,6 @@
 // Code for annotating snippets.
 
-use Level;
+use crate::Level;
 
 #[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)]
 pub struct Line {
diff --git a/src/librustc_errors/styled_buffer.rs b/src/librustc_errors/styled_buffer.rs
index 880f09e75e3..6e03618d2b0 100644
--- a/src/librustc_errors/styled_buffer.rs
+++ b/src/librustc_errors/styled_buffer.rs
@@ -1,6 +1,6 @@
 // Code for creating styled buffers
 
-use snippet::{Style, StyledString};
+use crate::snippet::{Style, StyledString};
 
 #[derive(Debug)]
 pub struct StyledBuffer {