Auto merge of #81271 - m-ou-se:rollup-xv7gq3w, r=m-ou-se

Rollup of 10 pull requests

Successful merges:

 - #80573 (Deny rustc::internal lints for rustdoc and clippy)
 - #81173 (Expand docs on Iterator::intersperse)
 - #81194 (Stabilize std::panic::panic_any.)
 - #81202 (Don't prefix 0x for each segments in `dbg!(Ipv6)`)
 - #81225 (Make 'docs' nullable in rustdoc-json output)
 - #81227 (Remove doctree::StructType)
 - #81233 (Document why not use concat! in dbg! macro)
 - #81236 (Gracefully handle loop labels missing leading `'` in different positions)
 - #81241 (Turn alloc's force_expr macro into a regular macro_rules.)
 - #81242 (Enforce statically that `MIN_NON_ZERO_CAP` is calculated at compile time)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

34 files changed, 416 insertions, 163 deletions

diff --git a/src/bootstrap/check.rs b/src/bootstrap/check.rs
index c19bb536ce8..6626fead774 100644
--- a/src/bootstrap/check.rs
+++ b/src/bootstrap/check.rs
@@ -320,6 +320,13 @@ macro_rules! tool_check_step {
                     cargo.arg("--all-targets");
                 }
 
+                // Enable internal lints for clippy and rustdoc
+                // NOTE: this intentionally doesn't enable lints for any other tools,
+                // see https://github.com/rust-lang/rust/pull/80573#issuecomment-754010776
+                if $path == "src/tools/rustdoc" || $path == "src/tools/clippy" {
+                    cargo.rustflag("-Zunstable-options");
+                }
+
                 builder.info(&format!(
                     "Checking stage{} {} artifacts ({} -> {})",
                     builder.top_stage,
diff --git a/src/librustdoc/clean/inline.rs b/src/librustdoc/clean/inline.rs
index 916684baf85..1f9e7f8ae5c 100644
--- a/src/librustdoc/clean/inline.rs
+++ b/src/librustdoc/clean/inline.rs
@@ -5,7 +5,7 @@ use std::iter::once;
 use rustc_ast as ast;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
-use rustc_hir::def::{CtorKind, DefKind, Res};
+use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX};
 use rustc_hir::Mutability;
 use rustc_metadata::creader::LoadedMacro;
@@ -17,7 +17,6 @@ use rustc_span::Span;
 
 use crate::clean::{self, Attributes, GetDefId, ToSource, TypeKind};
 use crate::core::DocContext;
-use crate::doctree;
 
 use super::Clean;
 
@@ -246,11 +245,7 @@ fn build_struct(cx: &DocContext<'_>, did: DefId) -> clean::Struct {
     let variant = cx.tcx.adt_def(did).non_enum_variant();
 
     clean::Struct {
-        struct_type: match variant.ctor_kind {
-            CtorKind::Fictive => doctree::Plain,
-            CtorKind::Fn => doctree::Tuple,
-            CtorKind::Const => doctree::Unit,
-        },
+        struct_type: variant.ctor_kind,
         generics: (cx.tcx.generics_of(did), predicates).clean(cx),
         fields: variant.fields.clean(cx),
         fields_stripped: false,
@@ -262,7 +257,6 @@ fn build_union(cx: &DocContext<'_>, did: DefId) -> clean::Union {
     let variant = cx.tcx.adt_def(did).non_enum_variant();
 
     clean::Union {
-        struct_type: doctree::Plain,
         generics: (cx.tcx.generics_of(did), predicates).clean(cx),
         fields: variant.fields.clean(cx),
         fields_stripped: false,
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 3ddb2adbf0a..8fa60fa7178 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1827,7 +1827,7 @@ impl Clean<Visibility> for ty::Visibility {
 impl Clean<VariantStruct> for rustc_hir::VariantData<'_> {
     fn clean(&self, cx: &DocContext<'_>) -> VariantStruct {
         VariantStruct {
-            struct_type: doctree::struct_type_from_def(self),
+            struct_type: CtorKind::from_hir(self),
             fields: self.fields().iter().map(|x| x.clean(cx)).collect(),
             fields_stripped: false,
         }
@@ -1842,7 +1842,7 @@ impl Clean<Item> for ty::VariantDef {
                 self.fields.iter().map(|f| cx.tcx.type_of(f.did).clean(cx)).collect(),
             ),
             CtorKind::Fictive => Variant::Struct(VariantStruct {
-                struct_type: doctree::Plain,
+                struct_type: CtorKind::Fictive,
                 fields_stripped: false,
                 fields: self
                     .fields
@@ -1996,13 +1996,12 @@ impl Clean<Vec<Item>> for (&hir::Item<'_>, Option<Symbol>) {
                     bounds: bounds.clean(cx),
                 }),
                 ItemKind::Union(ref variant_data, ref generics) => UnionItem(Union {
-                    struct_type: doctree::struct_type_from_def(&variant_data),
                     generics: generics.clean(cx),
                     fields: variant_data.fields().clean(cx),
                     fields_stripped: false,
                 }),
                 ItemKind::Struct(ref variant_data, ref generics) => StructItem(Struct {
-                    struct_type: doctree::struct_type_from_def(&variant_data),
+                    struct_type: CtorKind::from_hir(variant_data),
                     generics: generics.clean(cx),
                     fields: variant_data.fields().clean(cx),
                     fields_stripped: false,
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 666b11b5f80..c767b9dd85b 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -16,7 +16,7 @@ use rustc_attr::{ConstStability, Deprecation, Stability, StabilityLevel};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_feature::UnstableFeatures;
 use rustc_hir as hir;
-use rustc_hir::def::Res;
+use rustc_hir::def::{CtorKind, Res};
 use rustc_hir::def_id::{CrateNum, DefId};
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::Mutability;
@@ -37,7 +37,6 @@ use crate::clean::inline;
 use crate::clean::types::Type::{QPath, ResolvedPath};
 use crate::clean::Clean;
 use crate::core::DocContext;
-use crate::doctree;
 use crate::formats::cache::cache;
 use crate::formats::item_type::ItemType;
 use crate::html::render::cache::ExternalLocation;
@@ -1685,7 +1684,7 @@ impl Visibility {
 
 #[derive(Clone, Debug)]
 crate struct Struct {
-    crate struct_type: doctree::StructType,
+    crate struct_type: CtorKind,
     crate generics: Generics,
     crate fields: Vec<Item>,
     crate fields_stripped: bool,
@@ -1693,7 +1692,6 @@ crate struct Struct {
 
 #[derive(Clone, Debug)]
 crate struct Union {
-    crate struct_type: doctree::StructType,
     crate generics: Generics,
     crate fields: Vec<Item>,
     crate fields_stripped: bool,
@@ -1704,7 +1702,7 @@ crate struct Union {
 /// only as a variant in an enum.
 #[derive(Clone, Debug)]
 crate struct VariantStruct {
-    crate struct_type: doctree::StructType,
+    crate struct_type: CtorKind,
     crate fields: Vec<Item>,
     crate fields_stripped: bool,
 }
diff --git a/src/librustdoc/config.rs b/src/librustdoc/config.rs
index e43ea965c04..8006c3d2771 100644
--- a/src/librustdoc/config.rs
+++ b/src/librustdoc/config.rs
@@ -1,4 +1,4 @@
-use std::collections::{BTreeMap, HashMap};
+use std::collections::BTreeMap;
 use std::convert::TryFrom;
 use std::ffi::OsStr;
 use std::fmt;
@@ -219,7 +219,7 @@ crate struct RenderOptions {
     crate extern_html_root_urls: BTreeMap<String, String>,
     /// A map of the default settings (values are as for DOM storage API). Keys should lack the
     /// `rustdoc-` prefix.
-    crate default_settings: HashMap<String, String>,
+    crate default_settings: FxHashMap<String, String>,
     /// If present, suffix added to CSS/JavaScript files when referencing them in generated pages.
     crate resource_suffix: String,
     /// Whether to run the static CSS/JavaScript through a minifier when outputting them. `true` by
diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index c87ab833f7a..bbf4de5cdc9 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -1,4 +1,5 @@
 use rustc_ast as ast;
+use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{ColorConfig, ErrorReported};
 use rustc_hir as hir;
@@ -16,7 +17,6 @@ use rustc_span::{BytePos, FileName, Pos, Span, DUMMY_SP};
 use rustc_target::spec::TargetTriple;
 use tempfile::Builder as TempFileBuilder;
 
-use std::collections::HashMap;
 use std::env;
 use std::io::{self, Write};
 use std::panic;
@@ -704,7 +704,7 @@ crate struct Collector {
     position: Span,
     source_map: Option<Lrc<SourceMap>>,
     filename: Option<PathBuf>,
-    visited_tests: HashMap<(String, usize), usize>,
+    visited_tests: FxHashMap<(String, usize), usize>,
 }
 
 impl Collector {
@@ -728,7 +728,7 @@ impl Collector {
             position: DUMMY_SP,
             source_map,
             filename,
-            visited_tests: HashMap::new(),
+            visited_tests: FxHashMap::default(),
         }
     }
 
@@ -1010,7 +1010,7 @@ impl<'a, 'hir, 'tcx> HirCollector<'a, 'hir, 'tcx> {
                 self.codes,
                 self.collector.enable_per_target_ignores,
                 Some(&crate::html::markdown::ExtraInfo::new(
-                    &self.tcx,
+                    self.tcx,
                     hir_id,
                     span_of_attrs(&attrs).unwrap_or(sp),
                 )),
diff --git a/src/librustdoc/doctree.rs b/src/librustdoc/doctree.rs
index f90623c0311..645b2bb193e 100644
--- a/src/librustdoc/doctree.rs
+++ b/src/librustdoc/doctree.rs
@@ -1,7 +1,5 @@
 //! This module is used to store stuff from Rust's AST in a more convenient
 //! manner (and with prettier names) before cleaning.
-crate use self::StructType::*;
-
 use rustc_span::{self, Span, Symbol};
 
 use rustc_hir as hir;
@@ -34,21 +32,3 @@ impl Module<'hir> {
         }
     }
 }
-
-#[derive(Debug, Clone, Copy)]
-crate enum StructType {
-    /// A braced struct
-    Plain,
-    /// A tuple struct
-    Tuple,
-    /// A unit struct
-    Unit,
-}
-
-crate fn struct_type_from_def(vdata: &hir::VariantData<'_>) -> StructType {
-    match *vdata {
-        hir::VariantData::Struct(..) => Plain,
-        hir::VariantData::Tuple(..) => Tuple,
-        hir::VariantData::Unit(..) => Unit,
-    }
-}
diff --git a/src/librustdoc/formats/renderer.rs b/src/librustdoc/formats/renderer.rs
index c91d6decc0b..5c0f5e50c9e 100644
--- a/src/librustdoc/formats/renderer.rs
+++ b/src/librustdoc/formats/renderer.rs
@@ -1,6 +1,6 @@
 use std::sync::Arc;
 
-use rustc_middle::ty;
+use rustc_middle::ty::TyCtxt;
 use rustc_span::edition::Edition;
 
 use crate::clean;
@@ -20,7 +20,7 @@ crate trait FormatRenderer<'tcx>: Clone {
         render_info: RenderInfo,
         edition: Edition,
         cache: &mut Cache,
-        tcx: ty::TyCtxt<'tcx>,
+        tcx: TyCtxt<'tcx>,
     ) -> Result<(Self, clean::Crate), Error>;
 
     /// Renders a single non-module item. This means no recursive sub-item rendering is required.
@@ -55,7 +55,7 @@ crate fn run_format<'tcx, T: FormatRenderer<'tcx>>(
     render_info: RenderInfo,
     diag: &rustc_errors::Handler,
     edition: Edition,
-    tcx: ty::TyCtxt<'tcx>,
+    tcx: TyCtxt<'tcx>,
 ) -> Result<(), Error> {
     let (krate, mut cache) = Cache::from_krate(
         render_info.clone(),
diff --git a/src/librustdoc/html/layout.rs b/src/librustdoc/html/layout.rs
index 4458eea95f3..c6ff4b57a6e 100644
--- a/src/librustdoc/html/layout.rs
+++ b/src/librustdoc/html/layout.rs
@@ -1,6 +1,7 @@
-use std::collections::HashMap;
 use std::path::PathBuf;
 
+use rustc_data_structures::fx::FxHashMap;
+
 use crate::externalfiles::ExternalHtml;
 use crate::html::escape::Escape;
 use crate::html::format::{Buffer, Print};
@@ -11,7 +12,7 @@ crate struct Layout {
     crate logo: String,
     crate favicon: String,
     crate external_html: ExternalHtml,
-    crate default_settings: HashMap<String, String>,
+    crate default_settings: FxHashMap<String, String>,
     crate krate: String,
     /// The given user css file which allow to customize the generated
     /// documentation theme.
diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index cfa6cd96595..7c8b76be374 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -620,7 +620,7 @@ crate fn find_testable_code<T: doctest::Tester>(
     tests: &mut T,
     error_codes: ErrorCodes,
     enable_per_target_ignores: bool,
-    extra_info: Option<&ExtraInfo<'_, '_>>,
+    extra_info: Option<&ExtraInfo<'_>>,
 ) {
     let mut parser = Parser::new(doc).into_offset_iter();
     let mut prev_offset = 0;
@@ -681,19 +681,19 @@ crate fn find_testable_code<T: doctest::Tester>(
     }
 }
 
-crate struct ExtraInfo<'a, 'b> {
+crate struct ExtraInfo<'tcx> {
     hir_id: Option<HirId>,
     item_did: Option<DefId>,
     sp: Span,
-    tcx: &'a TyCtxt<'b>,
+    tcx: TyCtxt<'tcx>,
 }
 
-impl<'a, 'b> ExtraInfo<'a, 'b> {
-    crate fn new(tcx: &'a TyCtxt<'b>, hir_id: HirId, sp: Span) -> ExtraInfo<'a, 'b> {
+impl<'tcx> ExtraInfo<'tcx> {
+    crate fn new(tcx: TyCtxt<'tcx>, hir_id: HirId, sp: Span) -> ExtraInfo<'tcx> {
         ExtraInfo { hir_id: Some(hir_id), item_did: None, sp, tcx }
     }
 
-    crate fn new_did(tcx: &'a TyCtxt<'b>, did: DefId, sp: Span) -> ExtraInfo<'a, 'b> {
+    crate fn new_did(tcx: TyCtxt<'tcx>, did: DefId, sp: Span) -> ExtraInfo<'tcx> {
         ExtraInfo { hir_id: None, item_did: Some(did), sp, tcx }
     }
 
@@ -775,7 +775,7 @@ impl LangString {
         string: &str,
         allow_error_code_check: ErrorCodes,
         enable_per_target_ignores: bool,
-        extra: Option<&ExtraInfo<'_, '_>>,
+        extra: Option<&ExtraInfo<'_>>,
     ) -> LangString {
         let allow_error_code_check = allow_error_code_check.as_bool();
         let mut seen_rust_tags = false;
@@ -1208,7 +1208,7 @@ crate struct RustCodeBlock {
 
 /// Returns a range of bytes for each code block in the markdown that is tagged as `rust` or
 /// untagged (and assumed to be rust).
-crate fn rust_code_blocks(md: &str, extra_info: &ExtraInfo<'_, '_>) -> Vec<RustCodeBlock> {
+crate fn rust_code_blocks(md: &str, extra_info: &ExtraInfo<'_>) -> Vec<RustCodeBlock> {
     let mut code_blocks = vec![];
 
     if md.is_empty() {
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 26afd705740..6167b75ee50 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -52,10 +52,10 @@ use rustc_attr::{Deprecation, StabilityLevel};
 use rustc_data_structures::flock;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir as hir;
+use rustc_hir::def::CtorKind;
 use rustc_hir::def_id::{DefId, LOCAL_CRATE};
 use rustc_hir::Mutability;
 use rustc_middle::middle::stability;
-use rustc_middle::ty;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
 use rustc_span::edition::Edition;
@@ -68,7 +68,6 @@ use serde::{Serialize, Serializer};
 use crate::clean::{self, AttributesExt, GetDefId, RenderedLink, SelfTy, TypeKind};
 use crate::config::{RenderInfo, RenderOptions};
 use crate::docfs::{DocFS, PathError};
-use crate::doctree;
 use crate::error::Error;
 use crate::formats::cache::{cache, Cache};
 use crate::formats::item_type::ItemType;
@@ -390,7 +389,7 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
         _render_info: RenderInfo,
         edition: Edition,
         cache: &mut Cache,
-        tcx: ty::TyCtxt<'tcx>,
+        tcx: TyCtxt<'tcx>,
     ) -> Result<(Self, clean::Crate), Error> {
         // need to save a copy of the options for rendering the index page
         let md_opts = options.clone();
@@ -3104,7 +3103,7 @@ fn item_struct(
             _ => None,
         })
         .peekable();
-    if let doctree::Plain = s.struct_type {
+    if let CtorKind::Fictive = s.struct_type {
         if fields.peek().is_some() {
             write!(
                 w,
@@ -3354,7 +3353,7 @@ fn render_struct(
     w: &mut Buffer,
     it: &clean::Item,
     g: Option<&clean::Generics>,
-    ty: doctree::StructType,
+    ty: CtorKind,
     fields: &[clean::Item],
     tab: &str,
     structhead: bool,
@@ -3371,7 +3370,7 @@ fn render_struct(
         write!(w, "{}", g.print())
     }
     match ty {
-        doctree::Plain => {
+        CtorKind::Fictive => {
             if let Some(g) = g {
                 write!(w, "{}", WhereClause { gens: g, indent: 0, end_newline: true })
             }
@@ -3403,7 +3402,7 @@ fn render_struct(
             }
             write!(w, "}}");
         }
-        doctree::Tuple => {
+        CtorKind::Fn => {
             write!(w, "(");
             for (i, field) in fields.iter().enumerate() {
                 if i > 0 {
@@ -3428,7 +3427,7 @@ fn render_struct(
             }
             write!(w, ";");
         }
-        doctree::Unit => {
+        CtorKind::Const => {
             // Needed for PhantomData.
             if let Some(g) = g {
                 write!(w, "{}", WhereClause { gens: g, indent: 0, end_newline: false })
@@ -4463,7 +4462,7 @@ fn sidebar_struct(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, s: &clea
     let fields = get_struct_fields_name(&s.fields);
 
     if !fields.is_empty() {
-        if let doctree::Plain = s.struct_type {
+        if let CtorKind::Fictive = s.struct_type {
             sidebar.push_str(&format!(
                 "<a class=\"sidebar-title\" href=\"#fields\">Fields</a>\
                  <div class=\"sidebar-links\">{}</div>",
diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index 7d05cb016b6..bfd2141d9a1 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -5,11 +5,11 @@
 use std::convert::From;
 
 use rustc_ast::ast;
+use rustc_hir::def::CtorKind;
 use rustc_span::def_id::{DefId, CRATE_DEF_INDEX};
 use rustc_span::Pos;
 
 use crate::clean;
-use crate::doctree;
 use crate::formats::item_type::ItemType;
 use crate::json::types::*;
 use crate::json::JsonRenderer;
@@ -27,7 +27,7 @@ impl JsonRenderer<'_> {
                 name: name.map(|sym| sym.to_string()),
                 source: self.convert_span(source),
                 visibility: self.convert_visibility(visibility),
-                docs: attrs.collapsed_doc_value().unwrap_or_default(),
+                docs: attrs.collapsed_doc_value(),
                 links: attrs
                     .links
                     .into_iter()
@@ -210,9 +210,9 @@ impl From<clean::Struct> for Struct {
 
 impl From<clean::Union> for Struct {
     fn from(struct_: clean::Union) -> Self {
-        let clean::Union { struct_type, generics, fields, fields_stripped } = struct_;
+        let clean::Union { generics, fields, fields_stripped } = struct_;
         Struct {
-            struct_type: struct_type.into(),
+            struct_type: StructType::Union,
             generics: generics.into(),
             fields_stripped,
             fields: ids(fields),
@@ -221,13 +221,12 @@ impl From<clean::Union> for Struct {
     }
 }
 
-impl From<doctree::StructType> for StructType {
-    fn from(struct_type: doctree::StructType) -> Self {
-        use doctree::StructType::*;
+impl From<CtorKind> for StructType {
+    fn from(struct_type: CtorKind) -> Self {
         match struct_type {
-            Plain => StructType::Plain,
-            Tuple => StructType::Tuple,
-            Unit => StructType::Unit,
+            CtorKind::Fictive => StructType::Plain,
+            CtorKind::Fn => StructType::Tuple,
+            CtorKind::Const => StructType::Unit,
         }
     }
 }
diff --git a/src/librustdoc/json/mod.rs b/src/librustdoc/json/mod.rs
index 64500c1d911..dc50c8a76b2 100644
--- a/src/librustdoc/json/mod.rs
+++ b/src/librustdoc/json/mod.rs
@@ -13,7 +13,7 @@ use std::path::PathBuf;
 use std::rc::Rc;
 
 use rustc_data_structures::fx::FxHashMap;
-use rustc_middle::ty;
+use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
 use rustc_span::edition::Edition;
 
@@ -26,7 +26,7 @@ use crate::html::render::cache::ExternalLocation;
 
 #[derive(Clone)]
 crate struct JsonRenderer<'tcx> {
-    tcx: ty::TyCtxt<'tcx>,
+    tcx: TyCtxt<'tcx>,
     /// A mapping of IDs that contains all local items for this crate which gets output as a top
     /// level field of the JSON blob.
     index: Rc<RefCell<FxHashMap<types::Id, types::Item>>>,
@@ -131,7 +131,7 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
         _render_info: RenderInfo,
         _edition: Edition,
         _cache: &mut Cache,
-        tcx: ty::TyCtxt<'tcx>,
+        tcx: TyCtxt<'tcx>,
     ) -> Result<(Self, clean::Crate), Error> {
         debug!("Initializing json renderer");
         Ok((
@@ -241,7 +241,7 @@ impl<'tcx> FormatRenderer<'tcx> for JsonRenderer<'tcx> {
                     )
                 })
                 .collect(),
-            format_version: 1,
+            format_version: 2,
         };
         let mut p = self.out_path.clone();
         p.push(output.index.get(&output.root).unwrap().name.clone().unwrap());
diff --git a/src/librustdoc/json/types.rs b/src/librustdoc/json/types.rs
index 9335fe9be1a..66cf12954dd 100644
--- a/src/librustdoc/json/types.rs
+++ b/src/librustdoc/json/types.rs
@@ -68,8 +68,9 @@ pub struct Item {
     /// By default all documented items are public, but you can tell rustdoc to output private items
     /// so this field is needed to differentiate.
     pub visibility: Visibility,
-    /// The full markdown docstring of this item.
-    pub docs: String,
+    /// The full markdown docstring of this item. Absent if there is no documentation at all,
+    /// Some("") if there is some documentation but it is empty (EG `#[doc = ""]`).
+    pub docs: Option<String>,
     /// This mapping resolves [intra-doc links](https://github.com/rust-lang/rfcs/blob/master/text/1946-intra-rustdoc-links.md) from the docstring to their IDs
     pub links: FxHashMap<String, Id>,
     /// Stringified versions of the attributes on this item (e.g. `"#[inline]"`)
@@ -269,6 +270,7 @@ pub enum StructType {
     Plain,
     Tuple,
     Unit,
+    Union,
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index 719aca612f5..d17189b416d 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -18,6 +18,7 @@
 #![feature(str_split_once)]
 #![feature(iter_intersperse)]
 #![recursion_limit = "256"]
+#![deny(rustc::internal)]
 
 #[macro_use]
 extern crate lazy_static;
@@ -65,7 +66,7 @@ use std::process;
 use rustc_driver::abort_on_err;
 use rustc_errors::ErrorReported;
 use rustc_interface::interface;
-use rustc_middle::ty;
+use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{make_crate_type_option, ErrorOutputType, RustcOptGroup};
 use rustc_session::getopts;
 use rustc_session::{early_error, early_warn};
@@ -471,7 +472,7 @@ fn run_renderer<'tcx, T: formats::FormatRenderer<'tcx>>(
     render_info: config::RenderInfo,
     diag: &rustc_errors::Handler,
     edition: rustc_span::edition::Edition,
-    tcx: ty::TyCtxt<'tcx>,
+    tcx: TyCtxt<'tcx>,
 ) -> MainResult {
     match formats::run_format::<T>(krate, renderopts, render_info, &diag, edition, tcx) {
         Ok(_) => Ok(()),
diff --git a/src/librustdoc/passes/check_code_block_syntax.rs b/src/librustdoc/passes/check_code_block_syntax.rs
index 554392c213e..9516130034b 100644
--- a/src/librustdoc/passes/check_code_block_syntax.rs
+++ b/src/librustdoc/passes/check_code_block_syntax.rs
@@ -108,7 +108,7 @@ impl<'a, 'tcx> DocFolder for SyntaxChecker<'a, 'tcx> {
     fn fold_item(&mut self, item: clean::Item) -> Option<clean::Item> {
         if let Some(dox) = &item.attrs.collapsed_doc_value() {
             let sp = span_of_attrs(&item.attrs).unwrap_or(item.source.span());
-            let extra = crate::html::markdown::ExtraInfo::new_did(&self.cx.tcx, item.def_id, sp);
+            let extra = crate::html::markdown::ExtraInfo::new_did(self.cx.tcx, item.def_id, sp);
             for code_block in markdown::rust_code_blocks(&dox, &extra) {
                 self.check_rust_syntax(&item, &dox, code_block);
             }
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 2694450a520..002d8938f69 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -13,6 +13,7 @@ use rustc_hir::def::{
     PerNS,
 };
 use rustc_hir::def_id::{CrateNum, DefId};
+use rustc_middle::ty::TyCtxt;
 use rustc_middle::{bug, ty};
 use rustc_resolve::ParentScope;
 use rustc_session::lint::{
@@ -85,7 +86,7 @@ impl Res {
         }
     }
 
-    fn name(self, tcx: ty::TyCtxt<'_>) -> String {
+    fn name(self, tcx: TyCtxt<'_>) -> String {
         match self {
             Res::Def(_, id) => tcx.item_name(id).to_string(),
             Res::Primitive(prim) => prim.as_str().to_string(),
@@ -865,12 +866,11 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
 
         // FIXME(jynelson): this shouldn't go through stringification, rustdoc should just use the DefId directly
         let self_name = self_id.and_then(|self_id| {
-            use ty::TyKind;
             if matches!(self.cx.tcx.def_kind(self_id), DefKind::Impl) {
                 // using `ty.to_string()` (or any variant) has issues with raw idents
                 let ty = self.cx.tcx.type_of(self_id);
                 let name = match ty.kind() {
-                    TyKind::Adt(def, _) => Some(self.cx.tcx.item_name(def.did).to_string()),
+                    ty::Adt(def, _) => Some(self.cx.tcx.item_name(def.did).to_string()),
                     other if other.is_primitive() => Some(ty.to_string()),
                     _ => None,
                 };
diff --git a/src/test/ui/issues/issue-1962.fixed b/src/test/ui/issues/issue-1962.fixed
index b810a90ef37..897fd172b29 100644
--- a/src/test/ui/issues/issue-1962.fixed
+++ b/src/test/ui/issues/issue-1962.fixed
@@ -3,8 +3,8 @@
 
 fn main() {
     let mut i = 0;
-    loop { //~ ERROR denote infinite loops with `loop
+    'a: loop { //~ ERROR denote infinite loops with `loop
         i += 1;
-        if i == 5 { break; }
+        if i == 5 { break 'a; }
     }
 }
diff --git a/src/test/ui/issues/issue-1962.rs b/src/test/ui/issues/issue-1962.rs
index 00d2bbd2850..71e87410087 100644
--- a/src/test/ui/issues/issue-1962.rs
+++ b/src/test/ui/issues/issue-1962.rs
@@ -3,8 +3,8 @@
 
 fn main() {
     let mut i = 0;
-    while true { //~ ERROR denote infinite loops with `loop
+    'a: while true { //~ ERROR denote infinite loops with `loop
         i += 1;
-        if i == 5 { break; }
+        if i == 5 { break 'a; }
     }
 }
diff --git a/src/test/ui/issues/issue-1962.stderr b/src/test/ui/issues/issue-1962.stderr
index 17142912696..4c32a4cf3dd 100644
--- a/src/test/ui/issues/issue-1962.stderr
+++ b/src/test/ui/issues/issue-1962.stderr
@@ -1,8 +1,8 @@
 error: denote infinite loops with `loop { ... }`
   --> $DIR/issue-1962.rs:6:5
    |
-LL |     while true {
-   |     ^^^^^^^^^^ help: use `loop`
+LL |     'a: while true {
+   |     ^^^^^^^^^^^^^^ help: use `loop`
    |
    = note: requested on the command line with `-D while-true`
 
diff --git a/src/test/ui/issues/issue-27042.stderr b/src/test/ui/issues/issue-27042.stderr
index 7dee1a6a5f0..59ef28481d0 100644
--- a/src/test/ui/issues/issue-27042.stderr
+++ b/src/test/ui/issues/issue-27042.stderr
@@ -4,7 +4,7 @@ warning: denote infinite loops with `loop { ... }`
 LL | /         'b:
 LL | |
 LL | |         while true { break }; // but here we cite the whole loop
-   | |____________________________^ help: use `loop`
+   | |__________________^ help: use `loop`
    |
    = note: `#[warn(while_true)]` on by default
 
diff --git a/src/test/ui/label/label_misspelled.rs b/src/test/ui/label/label_misspelled.rs
index ebfd5642c9f..e3180b06ecb 100644
--- a/src/test/ui/label/label_misspelled.rs
+++ b/src/test/ui/label/label_misspelled.rs
@@ -1,18 +1,62 @@
+#![warn(unused_labels)]
+
 fn main() {
+    'while_loop: while true { //~ WARN denote infinite loops with
+        //~^ WARN unused label
+        while_loop;
+        //~^ ERROR cannot find value `while_loop` in this scope
+    };
+    'while_let: while let Some(_) = Some(()) {
+        //~^ WARN unused label
+        while_let;
+        //~^ ERROR cannot find value `while_let` in this scope
+    }
+    'for_loop: for _ in 0..3 {
+        //~^ WARN unused label
+        for_loop;
+        //~^ ERROR cannot find value `for_loop` in this scope
+    };
     'LOOP: loop {
+        //~^ WARN unused label
         LOOP;
         //~^ ERROR cannot find value `LOOP` in this scope
     };
+}
+
+fn foo() {
+    'LOOP: loop {
+        break LOOP;
+        //~^ ERROR cannot find value `LOOP` in this scope
+    };
     'while_loop: while true { //~ WARN denote infinite loops with
-        while_loop;
+        break while_loop;
         //~^ ERROR cannot find value `while_loop` in this scope
     };
     'while_let: while let Some(_) = Some(()) {
-        while_let;
+        break while_let;
         //~^ ERROR cannot find value `while_let` in this scope
     }
     'for_loop: for _ in 0..3 {
-        for_loop;
+        break for_loop;
         //~^ ERROR cannot find value `for_loop` in this scope
     };
 }
+
+fn bar() {
+    let foo = ();
+    'while_loop: while true { //~ WARN denote infinite loops with
+        //~^ WARN unused label
+        break foo;
+        //~^ ERROR `break` with value from a `while` loop
+    };
+    'while_let: while let Some(_) = Some(()) {
+        //~^ WARN unused label
+        break foo;
+        //~^ ERROR `break` with value from a `while` loop
+    }
+    'for_loop: for _ in 0..3 {
+        //~^ WARN unused label
+        break foo;
+        //~^ ERROR `break` with value from a `for` loop
+    };
+}
diff --git a/src/test/ui/label/label_misspelled.stderr b/src/test/ui/label/label_misspelled.stderr
index 1368ca4126c..b09695787a4 100644
--- a/src/test/ui/label/label_misspelled.stderr
+++ b/src/test/ui/label/label_misspelled.stderr
@@ -1,47 +1,206 @@
-error[E0425]: cannot find value `LOOP` in this scope
-  --> $DIR/label_misspelled.rs:3:9
-   |
-LL |         LOOP;
-   |         ^^^^
-   |         |
-   |         not found in this scope
-   |         help: a label with a similar name exists: `'LOOP`
-
 error[E0425]: cannot find value `while_loop` in this scope
-  --> $DIR/label_misspelled.rs:7:9
+  --> $DIR/label_misspelled.rs:6:9
    |
+LL |     'while_loop: while true {
+   |     ----------- a label with a similar name exists
+LL |
 LL |         while_loop;
-   |         ^^^^^^^^^^
-   |         |
-   |         not found in this scope
-   |         help: a label with a similar name exists: `'while_loop`
+   |         ^^^^^^^^^^ not found in this scope
 
 error[E0425]: cannot find value `while_let` in this scope
   --> $DIR/label_misspelled.rs:11:9
    |
+LL |     'while_let: while let Some(_) = Some(()) {
+   |     ---------- a label with a similar name exists
+LL |
 LL |         while_let;
-   |         ^^^^^^^^^
-   |         |
-   |         not found in this scope
-   |         help: a label with a similar name exists: `'while_let`
+   |         ^^^^^^^^^ not found in this scope
 
 error[E0425]: cannot find value `for_loop` in this scope
-  --> $DIR/label_misspelled.rs:15:9
+  --> $DIR/label_misspelled.rs:16:9
    |
+LL |     'for_loop: for _ in 0..3 {
+   |     --------- a label with a similar name exists
+LL |
 LL |         for_loop;
-   |         ^^^^^^^^
-   |         |
-   |         not found in this scope
-   |         help: a label with a similar name exists: `'for_loop`
+   |         ^^^^^^^^ not found in this scope
+
+error[E0425]: cannot find value `LOOP` in this scope
+  --> $DIR/label_misspelled.rs:21:9
+   |
+LL |     'LOOP: loop {
+   |     ----- a label with a similar name exists
+LL |
+LL |         LOOP;
+   |         ^^^^ not found in this scope
+
+error[E0425]: cannot find value `LOOP` in this scope
+  --> $DIR/label_misspelled.rs:28:15
+   |
+LL |     'LOOP: loop {
+   |     ----- a label with a similar name exists
+LL |         break LOOP;
+   |               ^^^^
+   |               |
+   |               not found in this scope
+   |               help: use the similarly named label: `'LOOP`
+
+error[E0425]: cannot find value `while_loop` in this scope
+  --> $DIR/label_misspelled.rs:32:15
+   |
+LL |     'while_loop: while true {
+   |     ----------- a label with a similar name exists
+LL |         break while_loop;
+   |               ^^^^^^^^^^
+   |               |
+   |               not found in this scope
+   |               help: use the similarly named label: `'while_loop`
+
+error[E0425]: cannot find value `while_let` in this scope
+  --> $DIR/label_misspelled.rs:36:15
+   |
+LL |     'while_let: while let Some(_) = Some(()) {
+   |     ---------- a label with a similar name exists
+LL |         break while_let;
+   |               ^^^^^^^^^
+   |               |
+   |               not found in this scope
+   |               help: use the similarly named label: `'while_let`
+
+error[E0425]: cannot find value `for_loop` in this scope
+  --> $DIR/label_misspelled.rs:40:15
+   |
+LL |     'for_loop: for _ in 0..3 {
+   |     --------- a label with a similar name exists
+LL |         break for_loop;
+   |               ^^^^^^^^
+   |               |
+   |               not found in this scope
+   |               help: use the similarly named label: `'for_loop`
+
+warning: unused label
+  --> $DIR/label_misspelled.rs:4:5
+   |
+LL |     'while_loop: while true {
+   |     ^^^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/label_misspelled.rs:1:9
+   |
+LL | #![warn(unused_labels)]
+   |         ^^^^^^^^^^^^^
 
 warning: denote infinite loops with `loop { ... }`
-  --> $DIR/label_misspelled.rs:6:5
+  --> $DIR/label_misspelled.rs:4:5
    |
 LL |     'while_loop: while true {
    |     ^^^^^^^^^^^^^^^^^^^^^^^ help: use `loop`
    |
    = note: `#[warn(while_true)]` on by default
 
-error: aborting due to 4 previous errors; 1 warning emitted
+warning: unused label
+  --> $DIR/label_misspelled.rs:9:5
+   |
+LL |     'while_let: while let Some(_) = Some(()) {
+   |     ^^^^^^^^^^
+
+warning: unused label
+  --> $DIR/label_misspelled.rs:14:5
+   |
+LL |     'for_loop: for _ in 0..3 {
+   |     ^^^^^^^^^
+
+warning: unused label
+  --> $DIR/label_misspelled.rs:19:5
+   |
+LL |     'LOOP: loop {
+   |     ^^^^^
+
+warning: denote infinite loops with `loop { ... }`
+  --> $DIR/label_misspelled.rs:31:5
+   |
+LL |     'while_loop: while true {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^ help: use `loop`
+
+warning: unused label
+  --> $DIR/label_misspelled.rs:47:5
+   |
+LL |     'while_loop: while true {
+   |     ^^^^^^^^^^^
+
+warning: denote infinite loops with `loop { ... }`
+  --> $DIR/label_misspelled.rs:47:5
+   |
+LL |     'while_loop: while true {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^ help: use `loop`
+
+warning: unused label
+  --> $DIR/label_misspelled.rs:52:5
+   |
+LL |     'while_let: while let Some(_) = Some(()) {
+   |     ^^^^^^^^^^
+
+warning: unused label
+  --> $DIR/label_misspelled.rs:57:5
+   |
+LL |     'for_loop: for _ in 0..3 {
+   |     ^^^^^^^^^
+
+error[E0571]: `break` with value from a `while` loop
+  --> $DIR/label_misspelled.rs:49:9
+   |
+LL |     'while_loop: while true {
+   |     ----------------------- you can't `break` with a value in a `while` loop
+LL |
+LL |         break foo;
+   |         ^^^^^^^^^ can only break with a value inside `loop` or breakable block
+   |
+help: use `break` on its own without a value inside this `while` loop
+   |
+LL |         break;
+   |         ^^^^^
+help: alternatively, you might have meant to use the available loop label
+   |
+LL |         break 'while_loop;
+   |               ^^^^^^^^^^^
+
+error[E0571]: `break` with value from a `while` loop
+  --> $DIR/label_misspelled.rs:54:9
+   |
+LL |     'while_let: while let Some(_) = Some(()) {
+   |     ---------------------------------------- you can't `break` with a value in a `while` loop
+LL |
+LL |         break foo;
+   |         ^^^^^^^^^ can only break with a value inside `loop` or breakable block
+   |
+help: use `break` on its own without a value inside this `while` loop
+   |
+LL |         break;
+   |         ^^^^^
+help: alternatively, you might have meant to use the available loop label
+   |
+LL |         break 'while_let;
+   |               ^^^^^^^^^^
+
+error[E0571]: `break` with value from a `for` loop
+  --> $DIR/label_misspelled.rs:59:9
+   |
+LL |     'for_loop: for _ in 0..3 {
+   |     ------------------------ you can't `break` with a value in a `for` loop
+LL |
+LL |         break foo;
+   |         ^^^^^^^^^ can only break with a value inside `loop` or breakable block
+   |
+help: use `break` on its own without a value inside this `for` loop
+   |
+LL |         break;
+   |         ^^^^^
+help: alternatively, you might have meant to use the available loop label
+   |
+LL |         break 'for_loop;
+   |               ^^^^^^^^^
+
+error: aborting due to 11 previous errors; 10 warnings emitted
 
-For more information about this error, try `rustc --explain E0425`.
+Some errors have detailed explanations: E0425, E0571.
+For more information about an error, try `rustc --explain E0425`.
diff --git a/src/test/ui/label/label_misspelled_2.rs b/src/test/ui/label/label_misspelled_2.rs
new file mode 100644
index 00000000000..55bbe6b30a5
--- /dev/null
+++ b/src/test/ui/label/label_misspelled_2.rs
@@ -0,0 +1,16 @@
+#![warn(unused_labels)]
+
+fn main() {
+    'a: for _ in 0..1 {
+        break 'a;
+    }
+    'b: for _ in 0..1 {
+        break b; //~ ERROR cannot find value `b` in this scope
+    }
+    c: for _ in 0..1 { //~ ERROR malformed loop label
+        break 'c;
+    }
+    d: for _ in 0..1 { //~ ERROR malformed loop label
+        break d; //~ ERROR cannot find value `d` in this scope
+    }
+}
diff --git a/src/test/ui/label/label_misspelled_2.stderr b/src/test/ui/label/label_misspelled_2.stderr
new file mode 100644
index 00000000000..960646d9894
--- /dev/null
+++ b/src/test/ui/label/label_misspelled_2.stderr
@@ -0,0 +1,37 @@
+error: malformed loop label
+  --> $DIR/label_misspelled_2.rs:10:5
+   |
+LL |     c: for _ in 0..1 {
+   |     ^ help: use the correct loop label format: `'c`
+
+error: malformed loop label
+  --> $DIR/label_misspelled_2.rs:13:5
+   |
+LL |     d: for _ in 0..1 {
+   |     ^ help: use the correct loop label format: `'d`
+
+error[E0425]: cannot find value `b` in this scope
+  --> $DIR/label_misspelled_2.rs:8:15
+   |
+LL |     'b: for _ in 0..1 {
+   |     -- a label with a similar name exists
+LL |         break b;
+   |               ^
+   |               |
+   |               not found in this scope
+   |               help: use the similarly named label: `'b`
+
+error[E0425]: cannot find value `d` in this scope
+  --> $DIR/label_misspelled_2.rs:14:15
+   |
+LL |     d: for _ in 0..1 {
+   |     - a label with a similar name exists
+LL |         break d;
+   |               ^
+   |               |
+   |               not found in this scope
+   |               help: use the similarly named label: `'d`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0425`.
diff --git a/src/test/ui/loops/loop-break-value-no-repeat.stderr b/src/test/ui/loops/loop-break-value-no-repeat.stderr
index ff93e9220e9..1c0d39a6e5a 100644
--- a/src/test/ui/loops/loop-break-value-no-repeat.stderr
+++ b/src/test/ui/loops/loop-break-value-no-repeat.stderr
@@ -1,10 +1,12 @@
 error[E0571]: `break` with value from a `for` loop
   --> $DIR/loop-break-value-no-repeat.rs:12:9
    |
+LL |     for _ in &[1,2,3] {
+   |     ----------------- you can't `break` with a value in a `for` loop
 LL |         break 22
    |         ^^^^^^^^ can only break with a value inside `loop` or breakable block
    |
-help: instead, use `break` on its own without a value inside this `for` loop
+help: use `break` on its own without a value inside this `for` loop
    |
 LL |         break
    |         ^^^^^
diff --git a/src/test/ui/loops/loop-break-value.rs b/src/test/ui/loops/loop-break-value.rs
index 8a080cfdf49..51c9a36a039 100644
--- a/src/test/ui/loops/loop-break-value.rs
+++ b/src/test/ui/loops/loop-break-value.rs
@@ -94,6 +94,5 @@ fn main() {
     'LOOP: for _ in 0 .. 9 {
         break LOOP;
         //~^ ERROR cannot find value `LOOP` in this scope
-        //~| ERROR `break` with value from a `for` loop
     }
 }
diff --git a/src/test/ui/loops/loop-break-value.stderr b/src/test/ui/loops/loop-break-value.stderr
index 0237435c8b4..adb099f9b17 100644
--- a/src/test/ui/loops/loop-break-value.stderr
+++ b/src/test/ui/loops/loop-break-value.stderr
@@ -1,11 +1,13 @@
 error[E0425]: cannot find value `LOOP` in this scope
   --> $DIR/loop-break-value.rs:95:15
    |
+LL |     'LOOP: for _ in 0 .. 9 {
+   |     ----- a label with a similar name exists
 LL |         break LOOP;
    |               ^^^^
    |               |
    |               not found in this scope
-   |               help: a label with a similar name exists: `'LOOP`
+   |               help: use the similarly named label: `'LOOP`
 
 warning: denote infinite loops with `loop { ... }`
   --> $DIR/loop-break-value.rs:26:5
@@ -18,32 +20,44 @@ LL |     'while_loop: while true {
 error[E0571]: `break` with value from a `while` loop
   --> $DIR/loop-break-value.rs:28:9
    |
+LL |     'while_loop: while true {
+   |     ----------------------- you can't `break` with a value in a `while` loop
+LL |         break;
 LL |         break ();
    |         ^^^^^^^^ can only break with a value inside `loop` or breakable block
    |
-help: instead, use `break` on its own without a value inside this `while` loop
+help: use `break` on its own without a value inside this `while` loop
    |
 LL |         break;
    |         ^^^^^
+help: alternatively, you might have meant to use the available loop label
+   |
+LL |         break 'while_loop;
+   |               ^^^^^^^^^^^
 
 error[E0571]: `break` with value from a `while` loop
   --> $DIR/loop-break-value.rs:30:13
    |
+LL |     'while_loop: while true {
+   |     ----------------------- you can't `break` with a value in a `while` loop
+...
 LL |             break 'while_loop 123;
    |             ^^^^^^^^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block
    |
-help: instead, use `break` on its own without a value inside this `while` loop
+help: use `break` on its own without a value inside this `while` loop
    |
-LL |             break;
-   |             ^^^^^
+LL |             break 'while_loop;
+   |             ^^^^^^^^^^^^^^^^^
 
 error[E0571]: `break` with value from a `while` loop
   --> $DIR/loop-break-value.rs:38:12
    |
+LL |     while let Some(_) = Some(()) {
+   |     ---------------------------- you can't `break` with a value in a `while` loop
 LL |         if break () {
    |            ^^^^^^^^ can only break with a value inside `loop` or breakable block
    |
-help: instead, use `break` on its own without a value inside this `while` loop
+help: use `break` on its own without a value inside this `while` loop
    |
 LL |         if break {
    |            ^^^^^
@@ -51,10 +65,12 @@ LL |         if break {
 error[E0571]: `break` with value from a `while` loop
   --> $DIR/loop-break-value.rs:43:9
    |
+LL |     while let Some(_) = Some(()) {
+   |     ---------------------------- you can't `break` with a value in a `while` loop
 LL |         break None;
    |         ^^^^^^^^^^ can only break with a value inside `loop` or breakable block
    |
-help: instead, use `break` on its own without a value inside this `while` loop
+help: use `break` on its own without a value inside this `while` loop
    |
 LL |         break;
    |         ^^^^^
@@ -62,21 +78,26 @@ LL |         break;
 error[E0571]: `break` with value from a `while` loop
   --> $DIR/loop-break-value.rs:49:13
    |
+LL |     'while_let_loop: while let Some(_) = Some(()) {
+   |     --------------------------------------------- you can't `break` with a value in a `while` loop
+LL |         loop {
 LL |             break 'while_let_loop "nope";
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block
    |
-help: instead, use `break` on its own without a value inside this `while` loop
+help: use `break` on its own without a value inside this `while` loop
    |
-LL |             break;
-   |             ^^^^^
+LL |             break 'while_let_loop;
+   |             ^^^^^^^^^^^^^^^^^^^^^
 
 error[E0571]: `break` with value from a `for` loop
   --> $DIR/loop-break-value.rs:56:9
    |
+LL |     for _ in &[1,2,3] {
+   |     ----------------- you can't `break` with a value in a `for` loop
 LL |         break ();
    |         ^^^^^^^^ can only break with a value inside `loop` or breakable block
    |
-help: instead, use `break` on its own without a value inside this `for` loop
+help: use `break` on its own without a value inside this `for` loop
    |
 LL |         break;
    |         ^^^^^
@@ -84,10 +105,13 @@ LL |         break;
 error[E0571]: `break` with value from a `for` loop
   --> $DIR/loop-break-value.rs:57:9
    |
+LL |     for _ in &[1,2,3] {
+   |     ----------------- you can't `break` with a value in a `for` loop
+LL |         break ();
 LL |         break [()];
    |         ^^^^^^^^^^ can only break with a value inside `loop` or breakable block
    |
-help: instead, use `break` on its own without a value inside this `for` loop
+help: use `break` on its own without a value inside this `for` loop
    |
 LL |         break;
    |         ^^^^^
@@ -95,24 +119,16 @@ LL |         break;
 error[E0571]: `break` with value from a `for` loop
   --> $DIR/loop-break-value.rs:64:13
    |
+LL |     'for_loop: for _ in &[1,2,3] {
+   |     ---------------------------- you can't `break` with a value in a `for` loop
+...
 LL |             break 'for_loop Some(17);
    |             ^^^^^^^^^^^^^^^^^^^^^^^^ can only break with a value inside `loop` or breakable block
    |
-help: instead, use `break` on its own without a value inside this `for` loop
-   |
-LL |             break;
-   |             ^^^^^
-
-error[E0571]: `break` with value from a `for` loop
-  --> $DIR/loop-break-value.rs:95:9
-   |
-LL |         break LOOP;
-   |         ^^^^^^^^^^ can only break with a value inside `loop` or breakable block
+help: use `break` on its own without a value inside this `for` loop
    |
-help: instead, use `break` on its own without a value inside this `for` loop
-   |
-LL |         break;
-   |         ^^^^^
+LL |             break 'for_loop;
+   |             ^^^^^^^^^^^^^^^
 
 error[E0308]: mismatched types
   --> $DIR/loop-break-value.rs:4:31
@@ -171,7 +187,7 @@ LL |         break;
    |         expected integer, found `()`
    |         help: give it a value of the expected type: `break value`
 
-error: aborting due to 18 previous errors; 1 warning emitted
+error: aborting due to 17 previous errors; 1 warning emitted
 
 Some errors have detailed explanations: E0308, E0425, E0571.
 For more information about an error, try `rustc --explain E0308`.
diff --git a/src/tools/clippy/clippy_lints/src/loops.rs b/src/tools/clippy/clippy_lints/src/loops.rs
index 1c5ab2874b0..bbcea387de2 100644
--- a/src/tools/clippy/clippy_lints/src/loops.rs
+++ b/src/tools/clippy/clippy_lints/src/loops.rs
@@ -533,7 +533,7 @@ impl<'tcx> LateLintPass<'tcx> for Loops {
         }
 
         // check for never_loop
-        if let ExprKind::Loop(ref block, _, _) = expr.kind {
+        if let ExprKind::Loop(ref block, _, _, _) = expr.kind {
             match never_loop_block(block, expr.hir_id) {
                 NeverLoopResult::AlwaysBreak => span_lint(cx, NEVER_LOOP, expr.span, "this loop never actually loops"),
                 NeverLoopResult::MayContinueMainLoop | NeverLoopResult::Otherwise => (),
@@ -543,7 +543,7 @@ impl<'tcx> LateLintPass<'tcx> for Loops {
         // check for `loop { if let {} else break }` that could be `while let`
         // (also matches an explicit "match" instead of "if let")
         // (even if the "match" or "if let" is used for declaration)
-        if let ExprKind::Loop(ref block, _, LoopSource::Loop) = expr.kind {
+        if let ExprKind::Loop(ref block, _, LoopSource::Loop, _) = expr.kind {
             // also check for empty `loop {}` statements, skipping those in #[panic_handler]
             if block.stmts.is_empty() && block.expr.is_none() && !is_in_panic_handler(cx, expr) {
                 let msg = "empty `loop {}` wastes CPU cycles";
@@ -738,7 +738,7 @@ fn never_loop_expr(expr: &Expr<'_>, main_loop_id: HirId) -> NeverLoopResult {
         | ExprKind::Assign(ref e1, ref e2, _)
         | ExprKind::AssignOp(_, ref e1, ref e2)
         | ExprKind::Index(ref e1, ref e2) => never_loop_expr_all(&mut [&**e1, &**e2].iter().cloned(), main_loop_id),
-        ExprKind::Loop(ref b, _, _) => {
+        ExprKind::Loop(ref b, _, _, _) => {
             // Break can come from the inner loop so remove them.
             absorb_break(&never_loop_block(b, main_loop_id))
         },
@@ -1314,7 +1314,7 @@ impl<'a, 'tcx> Visitor<'tcx> for SameItemPushVisitor<'a, 'tcx> {
     fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
         match &expr.kind {
             // Non-determinism may occur ... don't give a lint
-            ExprKind::Loop(_, _, _) | ExprKind::Match(_, _, _) => self.should_lint = false,
+            ExprKind::Loop(..) | ExprKind::Match(..) => self.should_lint = false,
             ExprKind::Block(block, _) => self.visit_block(block),
             _ => {},
         }
diff --git a/src/tools/clippy/clippy_lints/src/needless_continue.rs b/src/tools/clippy/clippy_lints/src/needless_continue.rs
index a971d041ca6..603071a5f4a 100644
--- a/src/tools/clippy/clippy_lints/src/needless_continue.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_continue.rs
@@ -221,7 +221,7 @@ where
 {
     if let ast::ExprKind::While(_, loop_block, label)
     | ast::ExprKind::ForLoop(_, _, loop_block, label)
-    | ast::ExprKind::Loop(loop_block, label) = &expr.kind
+    | ast::ExprKind::Loop(loop_block, label, ..) = &expr.kind
     {
         func(loop_block, label.as_ref());
     }
diff --git a/src/tools/clippy/clippy_lints/src/shadow.rs b/src/tools/clippy/clippy_lints/src/shadow.rs
index 24da056770c..d5b1767e945 100644
--- a/src/tools/clippy/clippy_lints/src/shadow.rs
+++ b/src/tools/clippy/clippy_lints/src/shadow.rs
@@ -325,7 +325,7 @@ fn check_expr<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, bindings: &mut
         | ExprKind::Field(ref e, _)
         | ExprKind::AddrOf(_, _, ref e)
         | ExprKind::Box(ref e) => check_expr(cx, e, bindings),
-        ExprKind::Block(ref block, _) | ExprKind::Loop(ref block, _, _) => check_block(cx, block, bindings),
+        ExprKind::Block(ref block, _) | ExprKind::Loop(ref block, ..) => check_block(cx, block, bindings),
         // ExprKind::Call
         // ExprKind::MethodCall
         ExprKind::Array(v) | ExprKind::Tup(v) => {
diff --git a/src/tools/clippy/clippy_lints/src/utils/author.rs b/src/tools/clippy/clippy_lints/src/utils/author.rs
index 43afa65de3e..ca60d335262 100644
--- a/src/tools/clippy/clippy_lints/src/utils/author.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/author.rs
@@ -317,7 +317,7 @@ impl<'tcx> Visitor<'tcx> for PrintVisitor {
                 self.current = cast_pat;
                 self.visit_expr(expr);
             },
-            ExprKind::Loop(ref body, _, desugaring) => {
+            ExprKind::Loop(ref body, _, desugaring, _) => {
                 let body_pat = self.next("body");
                 let des = loop_desugaring_name(desugaring);
                 let label_pat = self.next("label");
diff --git a/src/tools/clippy/clippy_lints/src/utils/higher.rs b/src/tools/clippy/clippy_lints/src/utils/higher.rs
index 9b3585865da..42ab9a1e7d2 100644
--- a/src/tools/clippy/clippy_lints/src/utils/higher.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/higher.rs
@@ -142,7 +142,7 @@ pub fn for_loop<'tcx>(
         if let hir::ExprKind::Match(ref iterexpr, ref arms, hir::MatchSource::ForLoopDesugar) = expr.kind;
         if let hir::ExprKind::Call(_, ref iterargs) = iterexpr.kind;
         if iterargs.len() == 1 && arms.len() == 1 && arms[0].guard.is_none();
-        if let hir::ExprKind::Loop(ref block, _, _) = arms[0].body.kind;
+        if let hir::ExprKind::Loop(ref block, ..) = arms[0].body.kind;
         if block.expr.is_none();
         if let [ _, _, ref let_stmt, ref body ] = *block.stmts;
         if let hir::StmtKind::Local(ref local) = let_stmt.kind;
@@ -158,7 +158,7 @@ pub fn for_loop<'tcx>(
 /// `while cond { body }` becomes `(cond, body)`.
 pub fn while_loop<'tcx>(expr: &'tcx hir::Expr<'tcx>) -> Option<(&'tcx hir::Expr<'tcx>, &'tcx hir::Expr<'tcx>)> {
     if_chain! {
-        if let hir::ExprKind::Loop(block, _, hir::LoopSource::While) = &expr.kind;
+        if let hir::ExprKind::Loop(block, _, hir::LoopSource::While, _) = &expr.kind;
         if let hir::Block { expr: Some(expr), .. } = &**block;
         if let hir::ExprKind::Match(cond, arms, hir::MatchSource::WhileDesugar) = &expr.kind;
         if let hir::ExprKind::DropTemps(cond) = &cond.kind;
diff --git a/src/tools/clippy/clippy_lints/src/utils/hir_utils.rs b/src/tools/clippy/clippy_lints/src/utils/hir_utils.rs
index 10120a8805d..6066383f2ef 100644
--- a/src/tools/clippy/clippy_lints/src/utils/hir_utils.rs
+++ b/src/tools/clippy/clippy_lints/src/utils/hir_utils.rs
@@ -123,7 +123,7 @@ impl<'a, 'tcx> SpanlessEq<'a, 'tcx> {
                 self.eq_expr(lc, rc) && self.eq_expr(&**lt, &**rt) && both(le, re, |l, r| self.eq_expr(l, r))
             },
             (&ExprKind::Lit(ref l), &ExprKind::Lit(ref r)) => l.node == r.node,
-            (&ExprKind::Loop(ref lb, ref ll, ref lls), &ExprKind::Loop(ref rb, ref rl, ref rls)) => {
+            (&ExprKind::Loop(ref lb, ref ll, ref lls, _), &ExprKind::Loop(ref rb, ref rl, ref rls, _)) => {
                 lls == rls && self.eq_block(lb, rb) && both(ll, rl, |l, r| l.ident.name == r.ident.name)
             },
             (&ExprKind::Match(ref le, ref la, ref ls), &ExprKind::Match(ref re, ref ra, ref rs)) => {
@@ -560,7 +560,7 @@ impl<'a, 'tcx> SpanlessHash<'a, 'tcx> {
             ExprKind::Lit(ref l) => {
                 l.node.hash(&mut self.s);
             },
-            ExprKind::Loop(ref b, ref i, _) => {
+            ExprKind::Loop(ref b, ref i, ..) => {
                 self.hash_block(b);
                 if let Some(i) = *i {
                     self.hash_name(i.ident.name);