From 929a64fd4c1ba210f47be6e10e28c43cf440f9fe Mon Sep 17 00:00:00 2001
From: Mara Bos <m-ou.se@m-ou.se>
Date: Thu, 31 Dec 2020 13:52:39 +0100
Subject: [PATCH 1/7] Improve library tracking issue template

---
 .../ISSUE_TEMPLATE/library_tracking_issue.md  | 32 +++++++++++++++----
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/.github/ISSUE_TEMPLATE/library_tracking_issue.md b/.github/ISSUE_TEMPLATE/library_tracking_issue.md
index 3e42594c8280d..cbc4465fcfe38 100644
--- a/.github/ISSUE_TEMPLATE/library_tracking_issue.md
+++ b/.github/ISSUE_TEMPLATE/library_tracking_issue.md
@@ -33,21 +33,41 @@ For most library features, it'd be useful to include a summarized version of the
 -->
 
 ```rust
-...
+// core::magic
+
+pub struct Magic;
+
+impl Magic {
+    pub fn magic(self);
+}
 ```
 
 ### Steps / History
 
 <!--
-In the simplest case, this is a PR implementing the feature followed by a PR
-that stabilises the feature. However it's not uncommon for the feature to be
-changed before stabilization. For larger features, the implementation could be
-split up in multiple steps.
+For larger features, more steps might be involved.
+If the feature is changed later, please add those PRs here as well.
 -->
 
-- [ ] Implementation: ...
+- [ ] Implementation: #...
+- [ ] Final commenting period (FCP)
 - [ ] Stabilization PR
 
+<!--
+Once the feature has gone through a few release cycles and there are no
+unresolved questions left, the feature might be ready for stabilization.
+
+If this feature didn't go through the RFC process, a final commenting period
+(FCP) is always needed before stabilization. This works as follows:
+
+A library team member can kick off the stabilization process, at which point
+the rfcbot will ask all the team members to verify they agree with
+stabilization. Once enough members agree and there are no concerns, the final
+commenting period begins: this issue will be marked as such and will be listed
+in the next This Week in Rust newsletter. If no blocking concerns are raised in
+that period of 10 days, a stabilzation PR can be opened by anyone.
+-->
+
 ### Unresolved Questions
 
 <!--

From 139ef750eee7ce1bc7cd7ee94e0f0d93a0d9a04b Mon Sep 17 00:00:00 2001
From: Joshua Nelson <jyn514@gmail.com>
Date: Fri, 1 Jan 2021 00:02:54 -0500
Subject: [PATCH 2/7] Clean bootstrap artifacts on `x.py clean`

---
 src/bootstrap/clean.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/bootstrap/clean.rs b/src/bootstrap/clean.rs
index f83dfe8e635e3..9b9df36e7dc0e 100644
--- a/src/bootstrap/clean.rs
+++ b/src/bootstrap/clean.rs
@@ -21,6 +21,7 @@ pub fn clean(build: &Build, all: bool) {
     } else {
         rm_rf(&build.out.join("tmp"));
         rm_rf(&build.out.join("dist"));
+        rm_rf(&build.out.join("bootstrap"));
 
         for host in &build.hosts {
             let entries = match build.out.join(host.triple).read_dir() {

From b31400a226aa494c4b245a0cfc4234a4edcd02a3 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Fri, 1 Jan 2021 14:44:19 +0100
Subject: [PATCH 3/7] improve unconditional_panic description

---
 compiler/rustc_lint_defs/src/builtin.rs | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index 1c692d4f20762..f90fc7fc9ab3c 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -221,14 +221,10 @@ declare_lint! {
     ///
     /// ### Explanation
     ///
-    /// This lint detects code that is very likely incorrect. When possible,
-    /// the compiler will attempt to detect situations where code can be
-    /// evaluated at compile-time to generate more efficient code. While
-    /// evaluating such code, if it detects that the code will unconditionally
-    /// panic, this usually indicates that it is doing something incorrectly.
-    /// If this lint is allowed, then the code will not be evaluated at
-    /// compile-time, and instead continue to generate code to evaluate at
-    /// runtime, which may panic during runtime.
+    /// This lint detects code that is very likely incorrect because it will
+    /// always panic, such as division by zero and out-of-bounds array
+    /// accesses. Consider adjusting your code if this is a bug, or using the
+    /// `panic!` or `unreachable!` macro instead in case the panic is intended.
     pub UNCONDITIONAL_PANIC,
     Deny,
     "operation will cause a panic at runtime"

From a5807ac61c82ca8c6768da0af04d76ceaf760c0a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Matthias=20Kr=C3=BCger?= <matthias.krueger@famsik.de>
Date: Thu, 31 Dec 2020 02:49:44 +0100
Subject: [PATCH 4/7] clippy fixes for librustdoc

fixes clippy warnings of type:
match_like_matches_macro
or_fun_call
op_ref
needless_return
let_and_return
single_char_add_str
useless_format
unnecessary_sort_by
match_ref_pats
redundant_field_names
---
 src/librustdoc/clean/auto_trait.rs            | 10 +++----
 src/librustdoc/clean/cfg.rs                   | 16 +++--------
 src/librustdoc/clean/mod.rs                   | 10 +++----
 src/librustdoc/clean/types.rs                 | 27 ++++++-------------
 src/librustdoc/config.rs                      |  5 +---
 src/librustdoc/doctest.rs                     |  6 ++---
 src/librustdoc/fold.rs                        |  2 +-
 src/librustdoc/html/format.rs                 | 18 ++++++-------
 src/librustdoc/html/markdown.rs               | 13 +++------
 src/librustdoc/html/render/mod.rs             | 16 ++++++-----
 src/librustdoc/html/toc.rs                    |  2 +-
 .../passes/collect_intra_doc_links.rs         |  8 +++---
 src/librustdoc/passes/html_tags.rs            |  2 +-
 src/librustdoc/passes/strip_hidden.rs         |  4 +--
 src/librustdoc/theme.rs                       |  7 ++---
 15 files changed, 58 insertions(+), 88 deletions(-)

diff --git a/src/librustdoc/clean/auto_trait.rs b/src/librustdoc/clean/auto_trait.rs
index 2a8b6a321f1c6..8b63ddddc1fa1 100644
--- a/src/librustdoc/clean/auto_trait.rs
+++ b/src/librustdoc/clean/auto_trait.rs
@@ -738,11 +738,11 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
     }
 
     fn is_fn_ty(&self, tcx: TyCtxt<'_>, ty: &Type) -> bool {
-        match &ty {
-            &&Type::ResolvedPath { ref did, .. } => {
-                *did == tcx.require_lang_item(LangItem::Fn, None)
-                    || *did == tcx.require_lang_item(LangItem::FnMut, None)
-                    || *did == tcx.require_lang_item(LangItem::FnOnce, None)
+        match ty {
+            &Type::ResolvedPath { did, .. } => {
+                did == tcx.require_lang_item(LangItem::Fn, None)
+                    || did == tcx.require_lang_item(LangItem::FnMut, None)
+                    || did == tcx.require_lang_item(LangItem::FnOnce, None)
             }
             _ => false,
         }
diff --git a/src/librustdoc/clean/cfg.rs b/src/librustdoc/clean/cfg.rs
index 2f169d1d3f3a5..444b73246da4b 100644
--- a/src/librustdoc/clean/cfg.rs
+++ b/src/librustdoc/clean/cfg.rs
@@ -177,10 +177,7 @@ impl Cfg {
             Cfg::Any(ref sub_cfgs) | Cfg::All(ref sub_cfgs) => {
                 sub_cfgs.first().map(Cfg::should_capitalize_first_letter).unwrap_or(false)
             }
-            Cfg::Cfg(name, _) => match name {
-                sym::debug_assertions | sym::target_endian => true,
-                _ => false,
-            },
+            Cfg::Cfg(name, _) => name == sym::debug_assertions || name == sym::target_endian,
         }
     }
 
@@ -188,18 +185,13 @@ impl Cfg {
         match *self {
             Cfg::False | Cfg::True => false,
             Cfg::Any(..) | Cfg::All(..) | Cfg::Cfg(..) => true,
-            Cfg::Not(ref child) => match **child {
-                Cfg::Cfg(..) => true,
-                _ => false,
-            },
+            Cfg::Not(box Cfg::Cfg(..)) => true,
+            Cfg::Not(..) => false,
         }
     }
 
     fn should_use_with_in_description(&self) -> bool {
-        match *self {
-            Cfg::Cfg(name, _) if name == sym::target_feature => true,
-            _ => false,
-        }
+        matches!(self, Cfg::Cfg(sym::target_feature, _))
     }
 
     /// Attempt to simplify this cfg by assuming that `assume` is already known to be true, will
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 2f430842f9d8e..14902c318c91d 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -640,10 +640,10 @@ impl Clean<Generics> for hir::Generics<'_> {
         ///
         /// [`lifetime_to_generic_param`]: rustc_ast_lowering::LoweringContext::lifetime_to_generic_param
         fn is_elided_lifetime(param: &hir::GenericParam<'_>) -> bool {
-            match param.kind {
-                hir::GenericParamKind::Lifetime { kind: hir::LifetimeParamKind::Elided } => true,
-                _ => false,
-            }
+            matches!(
+                param.kind,
+                hir::GenericParamKind::Lifetime { kind: hir::LifetimeParamKind::Elided }
+            )
         }
 
         let impl_trait_params = self
@@ -801,7 +801,7 @@ impl<'a, 'tcx> Clean<Generics> for (&'a ty::Generics, ty::GenericPredicates<'tcx
 
         for (param, mut bounds) in impl_trait {
             // Move trait bounds to the front.
-            bounds.sort_by_key(|b| if let GenericBound::TraitBound(..) = b { false } else { true });
+            bounds.sort_by_key(|b| !matches!(b, GenericBound::TraitBound(..)));
 
             if let crate::core::ImplTraitParam::ParamIndex(idx) = param {
                 if let Some(proj) = impl_trait_proj.remove(&idx) {
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 0d33bc9afd5ec..d0d37046e5905 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -175,11 +175,9 @@ impl Item {
     }
 
     crate fn is_crate(&self) -> bool {
-        match *self.kind {
+        matches!(*self.kind,
             StrippedItem(box ModuleItem(Module { is_crate: true, .. }))
-            | ModuleItem(Module { is_crate: true, .. }) => true,
-            _ => false,
-        }
+            | ModuleItem(Module { is_crate: true, .. }))
     }
     crate fn is_mod(&self) -> bool {
         self.type_() == ItemType::Module
@@ -378,10 +376,7 @@ impl ItemKind {
     }
 
     crate fn is_type_alias(&self) -> bool {
-        match *self {
-            ItemKind::TypedefItem(_, _) | ItemKind::AssocTypeItem(_, _) => true,
-            _ => false,
-        }
+        matches!(self, ItemKind::TypedefItem(..) | ItemKind::AssocTypeItem(..))
     }
 }
 
@@ -674,7 +669,7 @@ impl Attributes {
                                 span: attr.span,
                                 doc: contents,
                                 kind: DocFragmentKind::Include { filename },
-                                parent_module: parent_module,
+                                parent_module,
                             });
                         }
                     }
@@ -750,7 +745,7 @@ impl Attributes {
                     Some(did) => {
                         if let Some((mut href, ..)) = href(did) {
                             if let Some(ref fragment) = *fragment {
-                                href.push_str("#");
+                                href.push('#');
                                 href.push_str(fragment);
                             }
                             Some(RenderedLink {
@@ -945,10 +940,7 @@ crate enum GenericParamDefKind {
 
 impl GenericParamDefKind {
     crate fn is_type(&self) -> bool {
-        match *self {
-            GenericParamDefKind::Type { .. } => true,
-            _ => false,
-        }
+        matches!(self, GenericParamDefKind::Type { .. })
     }
 
     // FIXME(eddyb) this either returns the default of a type parameter, or the
@@ -1292,15 +1284,12 @@ impl Type {
     }
 
     crate fn is_full_generic(&self) -> bool {
-        match *self {
-            Type::Generic(_) => true,
-            _ => false,
-        }
+        matches!(self, Type::Generic(_))
     }
 
     crate fn projection(&self) -> Option<(&Type, DefId, Symbol)> {
         let (self_, trait_, name) = match self {
-            QPath { ref self_type, ref trait_, name } => (self_type, trait_, name),
+            QPath { self_type, trait_, name } => (self_type, trait_, name),
             _ => return None,
         };
         let trait_did = match **trait_ {
diff --git a/src/librustdoc/config.rs b/src/librustdoc/config.rs
index 2d58614b1397e..e43ea965c0423 100644
--- a/src/librustdoc/config.rs
+++ b/src/librustdoc/config.rs
@@ -37,10 +37,7 @@ crate enum OutputFormat {
 
 impl OutputFormat {
     crate fn is_json(&self) -> bool {
-        match self {
-            OutputFormat::Json => true,
-            _ => false,
-        }
+        matches!(self, OutputFormat::Json)
     }
 }
 
diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index 02dd42ce0c14d..0edb9babef46c 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -636,15 +636,15 @@ fn partition_source(s: &str) -> (String, String, String) {
         match state {
             PartitionState::Attrs => {
                 before.push_str(line);
-                before.push_str("\n");
+                before.push('\n');
             }
             PartitionState::Crates => {
                 crates.push_str(line);
-                crates.push_str("\n");
+                crates.push('\n');
             }
             PartitionState::Other => {
                 after.push_str(line);
-                after.push_str("\n");
+                after.push('\n');
             }
         }
     }
diff --git a/src/librustdoc/fold.rs b/src/librustdoc/fold.rs
index c39cc3ca39771..4d45c8866a793 100644
--- a/src/librustdoc/fold.rs
+++ b/src/librustdoc/fold.rs
@@ -61,7 +61,7 @@ crate trait DocFolder: Sized {
                         j.fields = j.fields.into_iter().filter_map(|x| self.fold_item(x)).collect();
                         j.fields_stripped |= num_fields != j.fields.len()
                             || j.fields.iter().any(|f| f.is_stripped());
-                        VariantItem(Variant { kind: VariantKind::Struct(j), ..i2 })
+                        VariantItem(Variant { kind: VariantKind::Struct(j) })
                     }
                     _ => VariantItem(i2),
                 }
diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index 9b2fb8582f54f..6eeb7ad82c0ac 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -245,7 +245,7 @@ impl<'a> fmt::Display for WhereClause<'a> {
             }
 
             match pred {
-                &clean::WherePredicate::BoundPredicate { ref ty, ref bounds } => {
+                clean::WherePredicate::BoundPredicate { ty, bounds } => {
                     let bounds = bounds;
                     if f.alternate() {
                         clause.push_str(&format!(
@@ -261,7 +261,7 @@ impl<'a> fmt::Display for WhereClause<'a> {
                         ));
                     }
                 }
-                &clean::WherePredicate::RegionPredicate { ref lifetime, ref bounds } => {
+                clean::WherePredicate::RegionPredicate { lifetime, bounds } => {
                     clause.push_str(&format!(
                         "{}: {}",
                         lifetime.print(),
@@ -272,7 +272,7 @@ impl<'a> fmt::Display for WhereClause<'a> {
                             .join(" + ")
                     ));
                 }
-                &clean::WherePredicate::EqPredicate { ref lhs, ref rhs } => {
+                clean::WherePredicate::EqPredicate { lhs, rhs } => {
                     if f.alternate() {
                         clause.push_str(&format!("{:#} == {:#}", lhs.print(), rhs.print()));
                     } else {
@@ -376,8 +376,8 @@ impl clean::GenericBound {
 impl clean::GenericArgs {
     fn print(&self) -> impl fmt::Display + '_ {
         display_fn(move |f| {
-            match *self {
-                clean::GenericArgs::AngleBracketed { ref args, ref bindings } => {
+            match self {
+                clean::GenericArgs::AngleBracketed { args, bindings } => {
                     if !args.is_empty() || !bindings.is_empty() {
                         if f.alternate() {
                             f.write_str("<")?;
@@ -414,7 +414,7 @@ impl clean::GenericArgs {
                         }
                     }
                 }
-                clean::GenericArgs::Parenthesized { ref inputs, ref output } => {
+                clean::GenericArgs::Parenthesized { inputs, output } => {
                     f.write_str("(")?;
                     let mut comma = false;
                     for ty in inputs {
@@ -501,7 +501,7 @@ crate fn href(did: DefId) -> Option<(String, ItemType, Vec<String>)> {
     };
     for component in &fqp[..fqp.len() - 1] {
         url.push_str(component);
-        url.push_str("/");
+        url.push('/');
     }
     match shortty {
         ItemType::Module => {
@@ -510,7 +510,7 @@ crate fn href(did: DefId) -> Option<(String, ItemType, Vec<String>)> {
         }
         _ => {
             url.push_str(shortty.as_str());
-            url.push_str(".");
+            url.push('.');
             url.push_str(fqp.last().unwrap());
             url.push_str(".html");
         }
@@ -1021,7 +1021,7 @@ impl Function<'_> {
                 } else {
                     if i > 0 {
                         args.push_str(" <br>");
-                        args_plain.push_str(" ");
+                        args_plain.push(' ');
                     }
                     if !input.name.is_empty() {
                         args.push_str(&format!("{}: ", input.name));
diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index 20cf48915c3c8..e519c6ee983f0 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -489,15 +489,10 @@ impl<'a, I: Iterator<Item = Event<'a>>> SummaryLine<'a, I> {
 }
 
 fn check_if_allowed_tag(t: &Tag<'_>) -> bool {
-    match *t {
-        Tag::Paragraph
-        | Tag::Item
-        | Tag::Emphasis
-        | Tag::Strong
-        | Tag::Link(..)
-        | Tag::BlockQuote => true,
-        _ => false,
-    }
+    matches!(
+        t,
+        Tag::Paragraph | Tag::Item | Tag::Emphasis | Tag::Strong | Tag::Link(..) | Tag::BlockQuote
+    )
 }
 
 impl<'a, I: Iterator<Item = Event<'a>>> Iterator for SummaryLine<'a, I> {
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index c19262b72cf72..2f5ee4f238d68 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -979,7 +979,7 @@ themePicker.onblur = handleThemeButtonsBlur;
                 .iter()
                 .map(|s| format!("\"{}\"", s.to_str().expect("invalid osstring conversion")))
                 .collect::<Vec<_>>();
-            files.sort_unstable_by(|a, b| a.cmp(b));
+            files.sort_unstable();
             let subs = subs.iter().map(|s| s.to_json_string()).collect::<Vec<_>>().join(",");
             let dirs =
                 if subs.is_empty() { String::new() } else { format!(",\"dirs\":[{}]", subs) };
@@ -1428,7 +1428,7 @@ impl Setting {
                     .map(|opt| format!(
                         "<option value=\"{}\" {}>{}</option>",
                         opt.0,
-                        if &opt.0 == default_value { "selected" } else { "" },
+                        if opt.0 == default_value { "selected" } else { "" },
                         opt.1,
                     ))
                     .collect::<String>(),
@@ -1595,7 +1595,7 @@ impl Context<'_> {
             if let Some(&(ref names, ty)) = cache.paths.get(&it.def_id) {
                 for name in &names[..names.len() - 1] {
                     url.push_str(name);
-                    url.push_str("/");
+                    url.push('/');
                 }
                 url.push_str(&item_path(ty, names.last().unwrap()));
                 layout::redirect(&url)
@@ -2308,7 +2308,7 @@ fn short_item_info(
             let since = &since.as_str();
             if !stability::deprecation_in_effect(is_since_rustc_version, Some(since)) {
                 if *since == "TBD" {
-                    format!("Deprecating in a future Rust version")
+                    String::from("Deprecating in a future Rust version")
                 } else {
                     format!("Deprecating in {}", Escape(since))
                 }
@@ -4323,9 +4323,11 @@ fn sidebar_assoc_items(it: &clean::Item) -> String {
                         .any(|i| i.inner_impl().trait_.def_id() == c.deref_mut_trait_did);
                     let inner_impl = target
                         .def_id()
-                        .or(target
-                            .primitive_type()
-                            .and_then(|prim| c.primitive_locations.get(&prim).cloned()))
+                        .or_else(|| {
+                            target
+                                .primitive_type()
+                                .and_then(|prim| c.primitive_locations.get(&prim).cloned())
+                        })
                         .and_then(|did| c.impls.get(&did));
                     if let Some(impls) = inner_impl {
                         out.push_str("<a class=\"sidebar-title\" href=\"#deref-methods\">");
diff --git a/src/librustdoc/html/toc.rs b/src/librustdoc/html/toc.rs
index b39a4e179cd16..c55f2459a9ce2 100644
--- a/src/librustdoc/html/toc.rs
+++ b/src/librustdoc/html/toc.rs
@@ -132,7 +132,7 @@ impl TocBuilder {
                 }
                 Some(entry) => {
                     sec_number = entry.sec_number.clone();
-                    sec_number.push_str(".");
+                    sec_number.push('.');
                     (entry.level, &entry.children)
                 }
             };
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index 9f15038a353b5..1719b35a3629d 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -1276,7 +1276,7 @@ impl LinkCollector<'_, '_> {
                         // This could just be a normal link or a broken link
                         // we could potentially check if something is
                         // "intra-doc-link-like" and warn in that case.
-                        return None;
+                        None
                     }
                     Err(ErrorKind::AnchorFailure(msg)) => {
                         anchor_failure(
@@ -1287,7 +1287,7 @@ impl LinkCollector<'_, '_> {
                             diag.link_range,
                             msg,
                         );
-                        return None;
+                        None
                     }
                 }
             }
@@ -1383,7 +1383,7 @@ impl LinkCollector<'_, '_> {
                         diag.link_range,
                         candidates.present_items().collect(),
                     );
-                    return None;
+                    None
                 }
             }
             Some(MacroNS) => {
@@ -1408,7 +1408,7 @@ impl LinkCollector<'_, '_> {
                             diag.link_range,
                             smallvec![kind],
                         );
-                        return None;
+                        None
                     }
                 }
             }
diff --git a/src/librustdoc/passes/html_tags.rs b/src/librustdoc/passes/html_tags.rs
index a7a1ba1118d1f..38ec2bef0adeb 100644
--- a/src/librustdoc/passes/html_tags.rs
+++ b/src/librustdoc/passes/html_tags.rs
@@ -59,7 +59,7 @@ fn drop_tag(
                 continue;
             }
             let last_tag_name_low = last_tag_name.to_lowercase();
-            if ALLOWED_UNCLOSED.iter().any(|&at| at == &last_tag_name_low) {
+            if ALLOWED_UNCLOSED.iter().any(|&at| at == last_tag_name_low) {
                 continue;
             }
             // `tags` is used as a queue, meaning that everything after `pos` is included inside it.
diff --git a/src/librustdoc/passes/strip_hidden.rs b/src/librustdoc/passes/strip_hidden.rs
index 01e3d0acaa855..a276b7a63371b 100644
--- a/src/librustdoc/passes/strip_hidden.rs
+++ b/src/librustdoc/passes/strip_hidden.rs
@@ -26,9 +26,7 @@ crate fn strip_hidden(krate: clean::Crate, _: &DocContext<'_>) -> clean::Crate {
 
     // strip all impls referencing stripped items
     let mut stripper = ImplStripper { retained: &retained };
-    let krate = stripper.fold_crate(krate);
-
-    krate
+    stripper.fold_crate(krate)
 }
 
 struct Stripper<'a> {
diff --git a/src/librustdoc/theme.rs b/src/librustdoc/theme.rs
index 3bcf64f91c9a6..2e14a8a977ed7 100644
--- a/src/librustdoc/theme.rs
+++ b/src/librustdoc/theme.rs
@@ -70,15 +70,12 @@ impl Events {
     }
 
     fn is_comment(&self) -> bool {
-        match *self {
-            Events::StartLineComment(_) | Events::StartComment(_) | Events::EndComment(_) => true,
-            _ => false,
-        }
+        matches!(self, Events::StartLineComment(_) | Events::StartComment(_) | Events::EndComment(_))
     }
 }
 
 fn previous_is_line_comment(events: &[Events]) -> bool {
-    if let Some(&Events::StartLineComment(_)) = events.last() { true } else { false }
+    matches!(events.last(), Some(&Events::StartLineComment(_)))
 }
 
 fn is_line_comment(pos: usize, v: &[u8], events: &[Events]) -> bool {

From ea0f6396aa25cadb84bfa37b098b1fb6916bc38f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9my=20Rakic?= <remy.rakic+github@gmail.com>
Date: Fri, 1 Jan 2021 22:35:56 +0100
Subject: [PATCH 5/7] const_generics_defaults: don't use todo

So that at least it won't ICE for users whether or not they enable the gate. For developers the FIXMEs are enough.
---
 compiler/rustc_ast_pretty/src/pprust/state.rs | 1 -
 compiler/rustc_hir_pretty/src/lib.rs          | 1 -
 compiler/rustc_save_analysis/src/sig.rs       | 1 -
 3 files changed, 3 deletions(-)

diff --git a/compiler/rustc_ast_pretty/src/pprust/state.rs b/compiler/rustc_ast_pretty/src/pprust/state.rs
index bdd378b34e144..0e4f2798bd313 100644
--- a/compiler/rustc_ast_pretty/src/pprust/state.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/state.rs
@@ -2677,7 +2677,6 @@ impl<'a> State<'a> {
                     s.print_type_bounds(":", &param.bounds);
                     if let Some(ref _default) = default {
                         // FIXME(const_generics_defaults): print the `default` value here
-                        todo!();
                     }
                 }
             }
diff --git a/compiler/rustc_hir_pretty/src/lib.rs b/compiler/rustc_hir_pretty/src/lib.rs
index 85bc38daa3d28..eb6c65fcd8c81 100644
--- a/compiler/rustc_hir_pretty/src/lib.rs
+++ b/compiler/rustc_hir_pretty/src/lib.rs
@@ -2210,7 +2210,6 @@ impl<'a> State<'a> {
                 self.print_type(ty);
                 if let Some(ref _default) = default {
                     // FIXME(const_generics_defaults): print the `default` value here
-                    todo!();
                 }
             }
         }
diff --git a/compiler/rustc_save_analysis/src/sig.rs b/compiler/rustc_save_analysis/src/sig.rs
index e7d1c9d3bbe58..ab3da270fe66f 100644
--- a/compiler/rustc_save_analysis/src/sig.rs
+++ b/compiler/rustc_save_analysis/src/sig.rs
@@ -619,7 +619,6 @@ impl<'hir> Sig for hir::Generics<'hir> {
                 param_text.push_str(&ty_to_string(&ty));
                 if let Some(ref _default) = default {
                     // FIXME(const_generics_defaults): push the `default` value here
-                    todo!();
                 }
             }
             if !param.bounds.is_empty() {

From eb0d5be441239ac5c401b5fe4f9cbb188b35595e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?D=C3=A1niel=20Buga?= <bugadani@gmail.com>
Date: Sat, 2 Jan 2021 10:58:50 +0100
Subject: [PATCH 6/7] Add test for #80607 with undesired output

---
 src/test/ui/issues/issue-80607.rs     | 10 ++++++++++
 src/test/ui/issues/issue-80607.stderr | 14 ++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 src/test/ui/issues/issue-80607.rs
 create mode 100644 src/test/ui/issues/issue-80607.stderr

diff --git a/src/test/ui/issues/issue-80607.rs b/src/test/ui/issues/issue-80607.rs
new file mode 100644
index 0000000000000..8bfda9a5c54b2
--- /dev/null
+++ b/src/test/ui/issues/issue-80607.rs
@@ -0,0 +1,10 @@
+// This tests makes sure the diagnostics print the offending enum variant, not just the type.
+pub enum Enum {
+    V1(i32),
+}
+
+pub fn foo(x: i32) -> Enum {
+    Enum::V1 { x } //~ ERROR field does not exist
+}
+
+fn main() {}
diff --git a/src/test/ui/issues/issue-80607.stderr b/src/test/ui/issues/issue-80607.stderr
new file mode 100644
index 0000000000000..cd405815c70df
--- /dev/null
+++ b/src/test/ui/issues/issue-80607.stderr
@@ -0,0 +1,14 @@
+error[E0559]: variant `Enum::V1` has no field named `x`
+  --> $DIR/issue-80607.rs:7:16
+   |
+LL |     V1(i32),
+   |     -- `Enum` defined here
+...
+LL |     Enum::V1 { x }
+   |     --------   ^ field does not exist
+   |     |
+   |     `Enum` is a tuple variant, use the appropriate syntax: `Enum(/* fields */)`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0559`.

From e0300716efc88a0b11f7121f8a15f5f385265b5d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?D=C3=A1niel=20Buga?= <bugadani@gmail.com>
Date: Sat, 2 Jan 2021 11:06:30 +0100
Subject: [PATCH 7/7] Print actual enum variant

---
 compiler/rustc_typeck/src/check/expr.rs | 49 ++++++++++++++++++-------
 src/test/ui/issues/issue-80607.rs       |  2 +-
 src/test/ui/issues/issue-80607.stderr   |  4 +-
 3 files changed, 39 insertions(+), 16 deletions(-)

diff --git a/compiler/rustc_typeck/src/check/expr.rs b/compiler/rustc_typeck/src/check/expr.rs
index 8197d02ec594b..e84d813ffbcc0 100644
--- a/compiler/rustc_typeck/src/check/expr.rs
+++ b/compiler/rustc_typeck/src/check/expr.rs
@@ -1381,19 +1381,42 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ty,
         );
         match variant.ctor_kind {
-            CtorKind::Fn => {
-                err.span_label(variant.ident.span, format!("`{adt}` defined here", adt = ty));
-                err.span_label(field.ident.span, "field does not exist");
-                err.span_label(
-                    ty_span,
-                    format!(
-                        "`{adt}` is a tuple {kind_name}, \
-                         use the appropriate syntax: `{adt}(/* fields */)`",
-                        adt = ty,
-                        kind_name = kind_name
-                    ),
-                );
-            }
+            CtorKind::Fn => match ty.kind() {
+                ty::Adt(adt, ..) if adt.is_enum() => {
+                    err.span_label(
+                        variant.ident.span,
+                        format!(
+                            "`{adt}::{variant}` defined here",
+                            adt = ty,
+                            variant = variant.ident,
+                        ),
+                    );
+                    err.span_label(field.ident.span, "field does not exist");
+                    err.span_label(
+                        ty_span,
+                        format!(
+                            "`{adt}::{variant}` is a tuple {kind_name}, \
+                             use the appropriate syntax: `{adt}::{variant}(/* fields */)`",
+                            adt = ty,
+                            variant = variant.ident,
+                            kind_name = kind_name
+                        ),
+                    );
+                }
+                _ => {
+                    err.span_label(variant.ident.span, format!("`{adt}` defined here", adt = ty));
+                    err.span_label(field.ident.span, "field does not exist");
+                    err.span_label(
+                        ty_span,
+                        format!(
+                            "`{adt}` is a tuple {kind_name}, \
+                                 use the appropriate syntax: `{adt}(/* fields */)`",
+                            adt = ty,
+                            kind_name = kind_name
+                        ),
+                    );
+                }
+            },
             _ => {
                 // prevent all specified fields from being suggested
                 let skip_fields = skip_fields.iter().map(|ref x| x.ident.name);
diff --git a/src/test/ui/issues/issue-80607.rs b/src/test/ui/issues/issue-80607.rs
index 8bfda9a5c54b2..63f4df359b831 100644
--- a/src/test/ui/issues/issue-80607.rs
+++ b/src/test/ui/issues/issue-80607.rs
@@ -4,7 +4,7 @@ pub enum Enum {
 }
 
 pub fn foo(x: i32) -> Enum {
-    Enum::V1 { x } //~ ERROR field does not exist
+    Enum::V1 { x } //~ ERROR `Enum::V1` has no field named `x`
 }
 
 fn main() {}
diff --git a/src/test/ui/issues/issue-80607.stderr b/src/test/ui/issues/issue-80607.stderr
index cd405815c70df..5375478942b18 100644
--- a/src/test/ui/issues/issue-80607.stderr
+++ b/src/test/ui/issues/issue-80607.stderr
@@ -2,12 +2,12 @@ error[E0559]: variant `Enum::V1` has no field named `x`
   --> $DIR/issue-80607.rs:7:16
    |
 LL |     V1(i32),
-   |     -- `Enum` defined here
+   |     -- `Enum::V1` defined here
 ...
 LL |     Enum::V1 { x }
    |     --------   ^ field does not exist
    |     |
-   |     `Enum` is a tuple variant, use the appropriate syntax: `Enum(/* fields */)`
+   |     `Enum::V1` is a tuple variant, use the appropriate syntax: `Enum::V1(/* fields */)`
 
 error: aborting due to previous error