Auto merge of #68201 - JohnTitor:rollup-26e39gu, r=JohnTitor

Rollup of 10 pull requests

Successful merges:

 - #67854 (Use `report_in_external_macro` for internal lints)
 - #67989 (rustdoc: Don't allow `#![feature(...)]` on stable or beta)
 - #68036 (libterm: parse extended terminfo format)
 - #68127 (Clarify the relationship between `extended` and `tools` in `config.toml`)
 - #68143 (Forbid elided lifetimes within const generic parameter types)
 - #68150 (Document behavior of set_nonblocking on UnixListener)
 - #68166 (rustdoc: HTML escape arrows on help popup)
 - #68176 (Clean up err codes)
 - #68179 (Remove unneeded scope)
 - #68188 (Tweak assertion note in format check)

Failed merges:

r? @ghost

17 files changed, 183 insertions, 76 deletions

diff --git a/config.toml.example b/config.toml.example
index bfd9e18cdd4..c9e17337ee2 100644
--- a/config.toml.example
+++ b/config.toml.example
@@ -181,21 +181,23 @@
 # Indicate whether the vendored sources are used for Rust dependencies or not
 #vendor = false
 
-# Typically the build system will build the rust compiler twice. The second
+# Typically the build system will build the Rust compiler twice. The second
 # compiler, however, will simply use its own libraries to link against. If you
 # would rather to perform a full bootstrap, compiling the compiler three times,
 # then you can set this option to true. You shouldn't ever need to set this
 # option to true.
 #full-bootstrap = false
 
-# Enable a build of the extended rust tool set which is not only the compiler
+# Enable a build of the extended Rust tool set which is not only the compiler
 # but also tools such as Cargo. This will also produce "combined installers"
 # which are used to install Rust and Cargo together. This is disabled by
-# default.
+# default. The `tools` option (immediately below) specifies which tools should
+# be built if `extended = true`.
 #extended = false
 
-# Installs chosen set of extended tools if enabled. By default builds all.
-# If chosen tool failed to build the installation fails.
+# Installs chosen set of extended tools if `extended = true`. By default builds all.
+# If chosen tool failed to build the installation fails. If `extended = false`, this
+# option is ignored.
 #tools = ["cargo", "rls", "clippy", "rustfmt", "analysis", "src"]
 
 # Verbosity level: 0 == not verbose, 1 == verbose, 2 == very verbose
diff --git a/src/bootstrap/format.rs b/src/bootstrap/format.rs
index 65b654fb519..6e5e3fe07e7 100644
--- a/src/bootstrap/format.rs
+++ b/src/bootstrap/format.rs
@@ -20,7 +20,15 @@ fn rustfmt(src: &Path, rustfmt: &Path, path: &Path, check: bool) {
     cmd.arg(&path);
     let cmd_debug = format!("{:?}", cmd);
     let status = cmd.status().expect("executing rustfmt");
-    assert!(status.success(), "running {} successful", cmd_debug);
+    if !status.success() {
+        eprintln!(
+            "Running `{}` failed.\nIf you're running `tidy`, \
+            try again with `--bless` flag. Or, you just want to format \
+            code, run `./x.py fmt` instead.",
+            cmd_debug,
+        );
+        std::process::exit(1);
+    }
 }
 
 #[derive(serde::Deserialize)]
diff --git a/src/librustc_ast_lowering/lib.rs b/src/librustc_ast_lowering/lib.rs
index d30d0bd8345..76a0889c376 100644
--- a/src/librustc_ast_lowering/lib.rs
+++ b/src/librustc_ast_lowering/lib.rs
@@ -2120,12 +2120,14 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
 
                 (hir::ParamName::Plain(param.ident), kind)
             }
-            GenericParamKind::Const { ref ty } => (
-                hir::ParamName::Plain(param.ident),
-                hir::GenericParamKind::Const {
-                    ty: self.lower_ty(&ty, ImplTraitContext::disallowed()),
-                },
-            ),
+            GenericParamKind::Const { ref ty } => {
+                let ty = self
+                    .with_anonymous_lifetime_mode(AnonymousLifetimeMode::ReportError, |this| {
+                        this.lower_ty(&ty, ImplTraitContext::disallowed())
+                    });
+
+                (hir::ParamName::Plain(param.ident), hir::GenericParamKind::Const { ty })
+            }
         };
 
         hir::GenericParam {
diff --git a/src/librustc_error_codes/error_codes/E0191.md b/src/librustc_error_codes/error_codes/E0191.md
index b79196f6cec..46b773bdc50 100644
--- a/src/librustc_error_codes/error_codes/E0191.md
+++ b/src/librustc_error_codes/error_codes/E0191.md
@@ -1,5 +1,6 @@
-Trait objects need to have all associated types specified. Erroneous code
-example:
+An associated type wasn't specified for a trait object.
+
+Erroneous code example:
 
 ```compile_fail,E0191
 trait Trait {
@@ -10,8 +11,9 @@ type Foo = Trait; // error: the value of the associated type `Bar` (from
                   //        the trait `Trait`) must be specified
 ```
 
-Please verify you specified all associated types of the trait and that you
-used the right trait. Example:
+Trait objects need to have all associated types specified. Please verify that
+all associated types of the trait were specified and the correct trait was used.
+Example:
 
 ```
 trait Trait {
diff --git a/src/librustc_error_codes/error_codes/E0192.md b/src/librustc_error_codes/error_codes/E0192.md
index 33308868cb2..5fd951b2e86 100644
--- a/src/librustc_error_codes/error_codes/E0192.md
+++ b/src/librustc_error_codes/error_codes/E0192.md
@@ -1,3 +1,19 @@
+A negative impl was added on a trait implementation.
+
+Erroneous code example:
+
+```compile_fail,E0192
+trait Trait {
+    type Bar;
+}
+
+struct Foo;
+
+impl !Trait for Foo { } //~ ERROR E0192
+
+fn main() {}
+```
+
 Negative impls are only allowed for auto traits. For more
 information see the [opt-in builtin traits RFC][RFC 19].
 
diff --git a/src/librustc_lint/internal.rs b/src/librustc_lint/internal.rs
index 2f8393bd906..5a5aedc2e97 100644
--- a/src/librustc_lint/internal.rs
+++ b/src/librustc_lint/internal.rs
@@ -12,7 +12,8 @@ use syntax::ast::{Ident, Item, ItemKind};
 declare_tool_lint! {
     pub rustc::DEFAULT_HASH_TYPES,
     Allow,
-    "forbid HashMap and HashSet and suggest the FxHash* variants"
+    "forbid HashMap and HashSet and suggest the FxHash* variants",
+    report_in_external_macro: true
 }
 
 pub struct DefaultHashTypes {
@@ -52,19 +53,22 @@ impl EarlyLintPass for DefaultHashTypes {
 declare_tool_lint! {
     pub rustc::USAGE_OF_TY_TYKIND,
     Allow,
-    "usage of `ty::TyKind` outside of the `ty::sty` module"
+    "usage of `ty::TyKind` outside of the `ty::sty` module",
+    report_in_external_macro: true
 }
 
 declare_tool_lint! {
     pub rustc::TY_PASS_BY_REFERENCE,
     Allow,
-    "passing `Ty` or `TyCtxt` by reference"
+    "passing `Ty` or `TyCtxt` by reference",
+    report_in_external_macro: true
 }
 
 declare_tool_lint! {
     pub rustc::USAGE_OF_QUALIFIED_TY,
     Allow,
-    "using `ty::{Ty,TyCtxt}` instead of importing it"
+    "using `ty::{Ty,TyCtxt}` instead of importing it",
+    report_in_external_macro: true
 }
 
 declare_lint_pass!(TyTyKind => [
diff --git a/src/librustc_span/symbol.rs b/src/librustc_span/symbol.rs
index a8b2db300a4..889f6099070 100644
--- a/src/librustc_span/symbol.rs
+++ b/src/librustc_span/symbol.rs
@@ -1049,6 +1049,7 @@ pub mod kw {
 }
 
 // This module has a very short name because it's used a lot.
+#[allow(rustc::default_hash_types)]
 pub mod sym {
     use super::Symbol;
     use std::convert::TryInto;
diff --git a/src/librustdoc/clean/auto_trait.rs b/src/librustdoc/clean/auto_trait.rs
index c8b63ed5c80..56013ee3a81 100644
--- a/src/librustdoc/clean/auto_trait.rs
+++ b/src/librustdoc/clean/auto_trait.rs
@@ -560,8 +560,8 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
                     lifetime_to_bounds.entry(lifetime).or_default().extend(bounds);
                 }
                 WherePredicate::EqPredicate { lhs, rhs } => {
-                    match &lhs {
-                        &Type::QPath { name: ref left_name, ref self_type, ref trait_ } => {
+                    match lhs {
+                        Type::QPath { name: ref left_name, ref self_type, ref trait_ } => {
                             let ty = &*self_type;
                             match **trait_ {
                                 Type::ResolvedPath {
@@ -580,36 +580,30 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
                                         continue;
                                     }
 
-                                    // FIXME: Remove this scope when NLL lands
-                                    {
-                                        let args = &mut new_trait_path
-                                            .segments
-                                            .last_mut()
-                                            .expect("segments were empty")
-                                            .args;
-
-                                        match args {
-                                            // Convert somethiung like '<T as Iterator::Item> = u8'
-                                            // to 'T: Iterator<Item=u8>'
-                                            &mut GenericArgs::AngleBracketed {
-                                                ref mut bindings,
-                                                ..
-                                            } => {
-                                                bindings.push(TypeBinding {
-                                                    name: left_name.clone(),
-                                                    kind: TypeBindingKind::Equality { ty: rhs },
-                                                });
-                                            }
-                                            &mut GenericArgs::Parenthesized { .. } => {
-                                                existing_predicates.push(
-                                                    WherePredicate::EqPredicate {
-                                                        lhs: lhs.clone(),
-                                                        rhs,
-                                                    },
-                                                );
-                                                continue; // If something other than a Fn ends up
-                                                // with parenthesis, leave it alone
-                                            }
+                                    let args = &mut new_trait_path
+                                        .segments
+                                        .last_mut()
+                                        .expect("segments were empty")
+                                        .args;
+
+                                    match args {
+                                        // Convert somethiung like '<T as Iterator::Item> = u8'
+                                        // to 'T: Iterator<Item=u8>'
+                                        GenericArgs::AngleBracketed {
+                                            ref mut bindings, ..
+                                        } => {
+                                            bindings.push(TypeBinding {
+                                                name: left_name.clone(),
+                                                kind: TypeBindingKind::Equality { ty: rhs },
+                                            });
+                                        }
+                                        GenericArgs::Parenthesized { .. } => {
+                                            existing_predicates.push(WherePredicate::EqPredicate {
+                                                lhs: lhs.clone(),
+                                                rhs,
+                                            });
+                                            continue; // If something other than a Fn ends up
+                                            // with parenthesis, leave it alone
                                         }
                                     }
 
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index 61a7bc765bc..4c8b8112fa8 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -307,8 +307,7 @@ pub fn run_core(options: RustdocOptions) -> (clean::Crate, RenderInfo, RenderOpt
         cg: codegen_options,
         externs,
         target_triple: target,
-        // Ensure that rustdoc works even if rustc is feature-staged
-        unstable_features: UnstableFeatures::Allow,
+        unstable_features: UnstableFeatures::from_environment(),
         actually_rustdoc: true,
         debugging_opts: debugging_options,
         error_format,
diff --git a/src/librustdoc/html/static/main.js b/src/librustdoc/html/static/main.js
index 8ccb74d6f15..809d38a7ead 100644
--- a/src/librustdoc/html/static/main.js
+++ b/src/librustdoc/html/static/main.js
@@ -2663,8 +2663,8 @@ function getSearchElement() {
             "Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, \
              <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, \
              and <code>const</code>.",
-            "Search functions by type signature (e.g., <code>vec -> usize</code> or \
-             <code>* -> vec</code>)",
+            "Search functions by type signature (e.g., <code>vec -&gt; usize</code> or \
+             <code>* -&gt; vec</code>)",
             "Search multiple things at once by splitting your query with comma (e.g., \
              <code>str,u8</code> or <code>String,struct:Vec,test</code>)",
             "You can look for items with an exact name by putting double quotes around \
diff --git a/src/libstd/sys/unix/ext/net.rs b/src/libstd/sys/unix/ext/net.rs
index e0e6e02a443..4c3cb67c9ee 100644
--- a/src/libstd/sys/unix/ext/net.rs
+++ b/src/libstd/sys/unix/ext/net.rs
@@ -902,6 +902,12 @@ impl UnixListener {
 
     /// Moves the socket into or out of nonblocking mode.
     ///
+    /// This will result in the `accept` operation becoming nonblocking,
+    /// i.e., immediately returning from their calls. If the IO operation is
+    /// successful, `Ok` is returned and no further action is required. If the
+    /// IO operation could not be completed and needs to be retried, an error
+    /// with kind [`io::ErrorKind::WouldBlock`] is returned.
+    ///
     /// # Examples
     ///
     /// ```no_run
@@ -913,6 +919,8 @@ impl UnixListener {
     ///     Ok(())
     /// }
     /// ```
+    ///
+    /// [`io::ErrorKind::WouldBlock`]: ../../../io/enum.ErrorKind.html#variant.WouldBlock
     #[stable(feature = "unix_socket", since = "1.10.0")]
     pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
         self.0.set_nonblocking(nonblocking)
diff --git a/src/libterm/lib.rs b/src/libterm/lib.rs
index d2e3b07ab85..2116b433fce 100644
--- a/src/libterm/lib.rs
+++ b/src/libterm/lib.rs
@@ -91,7 +91,7 @@ pub fn stderr() -> Option<Box<StderrTerminal>> {
 #[allow(missing_docs)]
 pub mod color {
     /// Number for a terminal color
-    pub type Color = u16;
+    pub type Color = u32;
 
     pub const BLACK: Color = 0;
     pub const RED: Color = 1;
diff --git a/src/libterm/terminfo/mod.rs b/src/libterm/terminfo/mod.rs
index f1adc536a3d..918875e792a 100644
--- a/src/libterm/terminfo/mod.rs
+++ b/src/libterm/terminfo/mod.rs
@@ -24,7 +24,7 @@ pub struct TermInfo {
     /// Map of capability name to boolean value
     pub bools: HashMap<String, bool>,
     /// Map of capability name to numeric value
-    pub numbers: HashMap<String, u16>,
+    pub numbers: HashMap<String, u32>,
     /// Map of capability name to raw (unexpanded) string
     pub strings: HashMap<String, Vec<u8>>,
 }
@@ -129,7 +129,7 @@ fn cap_for_attr(attr: Attr) -> &'static str {
 /// A Terminal that knows how many colors it supports, with a reference to its
 /// parsed Terminfo database record.
 pub struct TerminfoTerminal<T> {
-    num_colors: u16,
+    num_colors: u32,
     out: T,
     ti: TermInfo,
 }
diff --git a/src/libterm/terminfo/parser/compiled.rs b/src/libterm/terminfo/parser/compiled.rs
index d36adb72c8e..fbc5aebdb2c 100644
--- a/src/libterm/terminfo/parser/compiled.rs
+++ b/src/libterm/terminfo/parser/compiled.rs
@@ -159,16 +159,16 @@ pub static stringnames: &[&str] = &[ "cbt", "_", "cr", "csr", "tbc", "clear",
 
 fn read_le_u16(r: &mut dyn io::Read) -> io::Result<u16> {
     let mut b = [0; 2];
-    let mut amt = 0;
-    while amt < b.len() {
-        match r.read(&mut b[amt..])? {
-            0 => return Err(io::Error::new(io::ErrorKind::Other, "end of file")),
-            n => amt += n,
-        }
-    }
+    r.read_exact(&mut b)?;
     Ok((b[0] as u16) | ((b[1] as u16) << 8))
 }
 
+fn read_le_u32(r: &mut dyn io::Read) -> io::Result<u32> {
+    let mut b = [0; 4];
+    r.read_exact(&mut b)?;
+    Ok((b[0] as u32) | ((b[1] as u32) << 8) | ((b[2] as u32) << 16) | ((b[3] as u32) << 24))
+}
+
 fn read_byte(r: &mut dyn io::Read) -> io::Result<u8> {
     match r.bytes().next() {
         Some(s) => s,
@@ -194,9 +194,12 @@ pub fn parse(file: &mut dyn io::Read, longnames: bool) -> Result<TermInfo, Strin
 
     // Check magic number
     let magic = t!(read_le_u16(file));
-    if magic != 0x011A {
-        return Err(format!("invalid magic number: expected {:x}, found {:x}", 0x011A, magic));
-    }
+
+    let extended = match magic {
+        0o0432 => false,
+        0o01036 => true,
+        _ => return Err(format!("invalid magic number, found {:o}", magic)),
+    };
 
     // According to the spec, these fields must be >= -1 where -1 means that the feature is not
     // supported. Using 0 instead of -1 works because we skip sections with length 0.
@@ -258,11 +261,15 @@ pub fn parse(file: &mut dyn io::Read, longnames: bool) -> Result<TermInfo, Strin
         t!(read_byte(file)); // compensate for padding
     }
 
-    let numbers_map: HashMap<String, u16> = t! {
-        (0..numbers_count).filter_map(|i| match read_le_u16(file) {
-            Ok(0xFFFF) => None,
-            Ok(n) => Some(Ok((nnames[i].to_string(), n))),
-            Err(e) => Some(Err(e))
+    let numbers_map: HashMap<String, u32> = t! {
+        (0..numbers_count).filter_map(|i| {
+            let number = if extended { read_le_u32(file) } else { read_le_u16(file).map(Into::into) };
+
+            match number {
+                Ok(0xFFFF) => None,
+                Ok(n) => Some(Ok((nnames[i].to_string(), n))),
+                Err(e) => Some(Err(e))
+            }
         }).collect()
     };
 
@@ -318,7 +325,7 @@ pub fn msys_terminfo() -> TermInfo {
     strings.insert("setab".to_string(), b"\x1B[4%p1%dm".to_vec());
 
     let mut numbers = HashMap::new();
-    numbers.insert("colors".to_string(), 8u16);
+    numbers.insert("colors".to_string(), 8);
 
     TermInfo {
         names: vec!["cygwin".to_string()], // msys is a fork of an older cygwin version
diff --git a/src/libterm/win.rs b/src/libterm/win.rs
index b6c607a3081..c24cf9518aa 100644
--- a/src/libterm/win.rs
+++ b/src/libterm/win.rs
@@ -89,7 +89,7 @@ fn bits_to_color(bits: u16) -> color::Color {
         _ => unreachable!(),
     };
 
-    color | (bits & 0x8) // copy the hi-intensity bit
+    color | (u32::from(bits) & 0x8) // copy the hi-intensity bit
 }
 
 impl<T: Write + Send + 'static> WinConsole<T> {
diff --git a/src/test/ui/const-generics/const-param-elided-lifetime.rs b/src/test/ui/const-generics/const-param-elided-lifetime.rs
new file mode 100644
index 00000000000..5679dd35c30
--- /dev/null
+++ b/src/test/ui/const-generics/const-param-elided-lifetime.rs
@@ -0,0 +1,24 @@
+// Elided lifetimes within the type of a const generic parameters is disallowed. This matches the
+// behaviour of trait bounds where `fn foo<T: Ord<&u8>>() {}` is illegal. Though we could change
+// elided lifetimes within the type of a const generic parameters to be 'static, like elided
+// lifetimes within const/static items.
+
+#![feature(const_generics)]
+//~^ WARN the feature `const_generics` is incomplete and may cause the compiler to crash
+
+struct A<const N: &u8>;
+//~^ ERROR `&` without an explicit lifetime name cannot be used here
+trait B {}
+
+impl<const N: &u8> A<N> { //~ ERROR `&` without an explicit lifetime name cannot be used here
+    fn foo<const M: &u8>(&self) {}
+    //~^ ERROR `&` without an explicit lifetime name cannot be used here
+}
+
+impl<const N: &u8> B for A<N> {}
+//~^ ERROR `&` without an explicit lifetime name cannot be used here
+
+fn bar<const N: &u8>() {}
+//~^ ERROR `&` without an explicit lifetime name cannot be used here
+
+fn main() {}
diff --git a/src/test/ui/const-generics/const-param-elided-lifetime.stderr b/src/test/ui/const-generics/const-param-elided-lifetime.stderr
new file mode 100644
index 00000000000..93133c507fe
--- /dev/null
+++ b/src/test/ui/const-generics/const-param-elided-lifetime.stderr
@@ -0,0 +1,40 @@
+error[E0637]: `&` without an explicit lifetime name cannot be used here
+  --> $DIR/const-param-elided-lifetime.rs:9:19
+   |
+LL | struct A<const N: &u8>;
+   |                   ^ explicit lifetime name needed here
+
+error[E0637]: `&` without an explicit lifetime name cannot be used here
+  --> $DIR/const-param-elided-lifetime.rs:13:15
+   |
+LL | impl<const N: &u8> A<N> {
+   |               ^ explicit lifetime name needed here
+
+error[E0637]: `&` without an explicit lifetime name cannot be used here
+  --> $DIR/const-param-elided-lifetime.rs:14:21
+   |
+LL |     fn foo<const M: &u8>(&self) {}
+   |                     ^ explicit lifetime name needed here
+
+error[E0637]: `&` without an explicit lifetime name cannot be used here
+  --> $DIR/const-param-elided-lifetime.rs:18:15
+   |
+LL | impl<const N: &u8> B for A<N> {}
+   |               ^ explicit lifetime name needed here
+
+error[E0637]: `&` without an explicit lifetime name cannot be used here
+  --> $DIR/const-param-elided-lifetime.rs:21:17
+   |
+LL | fn bar<const N: &u8>() {}
+   |                 ^ explicit lifetime name needed here
+
+warning: the feature `const_generics` is incomplete and may cause the compiler to crash
+  --> $DIR/const-param-elided-lifetime.rs:6:12
+   |
+LL | #![feature(const_generics)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: `#[warn(incomplete_features)]` on by default
+
+error: aborting due to 5 previous errors
+