Auto merge of #86920 - JohnTitor:rollup-buvzpkr, r=JohnTitor

Rollup of 8 pull requests

Successful merges:

 - #80918 (Add Integer::log variants)
 - #86717 (Rename some Rust 2021 lints to better names )
 - #86819 (Clean up rustdoc IDs)
 - #86880 (Test ManuallyDrop::clone_from.)
 - #86906 (Replace deprecated compare_and_swap and fix typo in core::sync::atomic::{fence, compiler_fence} docs)
 - #86907 (Migrate `cpu-usage-over-time.py` to Python 3)
 - #86916 (rewrote documentation for thread::yield_now())
 - #86919 (Update books)

Failed merges:

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

compiler/rustc_expand/src/mbe/macro_rules.rs

@@ -18,7 +18,9 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_feature::Features;
-use rustc_lint_defs::builtin::{OR_PATTERNS_BACK_COMPAT, SEMICOLON_IN_EXPRESSIONS_FROM_MACROS};
+use rustc_lint_defs::builtin::{
+    RUST_2021_INCOMPATIBLE_OR_PATTERNS, SEMICOLON_IN_EXPRESSIONS_FROM_MACROS,
+};
 use rustc_lint_defs::BuiltinLintDiagnostics;
 use rustc_parse::parser::Parser;
 use rustc_session::parse::ParseSess;
@@ -975,7 +977,7 @@ fn check_matcher_core(
                             Some(NonterminalKind::PatParam { inferred: false }),
                         ));
                         sess.buffer_lint_with_diagnostic(
-                            &OR_PATTERNS_BACK_COMPAT,
+                            &RUST_2021_INCOMPATIBLE_OR_PATTERNS,
                             span,
                             ast::CRATE_NODE_ID,
                             "the meaning of the `pat` fragment specifier is changing in Rust 2021, which may affect this macro",

compiler/rustc_lint/src/lib.rs

@@ -325,6 +325,9 @@ fn register_builtins(store: &mut LintStore, no_interleave_lints: bool) {
     store.register_renamed("redundant_semicolon", "redundant_semicolons");
     store.register_renamed("overlapping_patterns", "overlapping_range_endpoints");
     store.register_renamed("safe_packed_borrows", "unaligned_references");
+    store.register_renamed("disjoint_capture_migration", "rust_2021_incompatible_closure_captures");
+    store.register_renamed("or_patterns_back_compat", "rust_2021_incompatible_or_patterns");
+    store.register_renamed("non_fmt_panic", "non_fmt_panics");
 
     // These were moved to tool lints, but rustc still sees them when compiling normally, before
     // tool lints are registered, so `check_tool_name_for_backwards_compat` doesn't work. Use

compiler/rustc_lint/src/non_fmt_panic.rs

@@ -9,7 +9,7 @@ use rustc_span::edition::Edition;
 use rustc_span::{hygiene, sym, symbol::kw, symbol::SymbolStr, InnerSpan, Span, Symbol};
 
 declare_lint! {
-    /// The `non_fmt_panic` lint detects `panic!(..)` invocations where the first
+    /// The `non_fmt_panics` lint detects `panic!(..)` invocations where the first
     /// argument is not a formatting string.
     ///
     /// ### Example
@@ -29,7 +29,7 @@ declare_lint! {
     /// an `i32` as message.
     ///
     /// Rust 2021 always interprets the first argument as format string.
-    NON_FMT_PANIC,
+    NON_FMT_PANICS,
     Warn,
     "detect single-argument panic!() invocations in which the argument is not a format string",
     @future_incompatible = FutureIncompatibleInfo {
@@ -39,7 +39,7 @@ declare_lint! {
     report_in_external_macro
 }
 
-declare_lint_pass!(NonPanicFmt => [NON_FMT_PANIC]);
+declare_lint_pass!(NonPanicFmt => [NON_FMT_PANICS]);
 
 impl<'tcx> LateLintPass<'tcx> for NonPanicFmt {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'tcx>) {
@@ -91,7 +91,7 @@ fn check_panic<'tcx>(cx: &LateContext<'tcx>, f: &'tcx hir::Expr<'tcx>, arg: &'tc
         arg_span = expn.call_site;
     }
 
-    cx.struct_span_lint(NON_FMT_PANIC, arg_span, |lint| {
+    cx.struct_span_lint(NON_FMT_PANICS, arg_span, |lint| {
         let mut l = lint.build("panic message is not a string literal");
         l.note("this usage of panic!() is deprecated; it will be a hard error in Rust 2021");
         l.note("for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/panic-macro-consistency.html>");
@@ -174,7 +174,7 @@ fn check_panic_str<'tcx>(
             [] => vec![fmt_span],
             v => v.iter().map(|span| fmt_span.from_inner(*span)).collect(),
         };
-        cx.struct_span_lint(NON_FMT_PANIC, arg_spans, |lint| {
+        cx.struct_span_lint(NON_FMT_PANICS, arg_spans, |lint| {
             let mut l = lint.build(match n_arguments {
                 1 => "panic message contains an unused formatting placeholder",
                 _ => "panic message contains unused formatting placeholders",
@@ -208,7 +208,7 @@ fn check_panic_str<'tcx>(
             Some(v) if v.len() == 1 => "panic message contains a brace",
             _ => "panic message contains braces",
         };
-        cx.struct_span_lint(NON_FMT_PANIC, brace_spans.unwrap_or_else(|| vec![span]), |lint| {
+        cx.struct_span_lint(NON_FMT_PANICS, brace_spans.unwrap_or_else(|| vec![span]), |lint| {
             let mut l = lint.build(msg);
             l.note("this message is not used as a format string, but will be in Rust 2021");
             if span.contains(arg.span) {

compiler/rustc_lint_defs/src/builtin.rs

@@ -2967,13 +2967,13 @@ declare_lint_pass! {
         MISSING_ABI,
         INVALID_DOC_ATTRIBUTES,
         SEMICOLON_IN_EXPRESSIONS_FROM_MACROS,
-        DISJOINT_CAPTURE_MIGRATION,
+        RUST_2021_INCOMPATIBLE_CLOSURE_CAPTURES,
         LEGACY_DERIVE_HELPERS,
         PROC_MACRO_BACK_COMPAT,
-        OR_PATTERNS_BACK_COMPAT,
+        RUST_2021_INCOMPATIBLE_OR_PATTERNS,
         LARGE_ASSIGNMENTS,
-        FUTURE_PRELUDE_COLLISION,
+        RUST_2021_PRELUDE_COLLISIONS,
-        RESERVED_PREFIX,
+        RUST_2021_PREFIXES_INCOMPATIBLE_SYNTAX,
         UNSUPPORTED_CALLING_CONVENTIONS,
     ]
 }
@@ -3002,7 +3002,7 @@ declare_lint! {
 }
 
 declare_lint! {
-    /// The `disjoint_capture_migration` lint detects variables that aren't completely
+    /// The `rust_2021_incompatible_closure_captures` lint detects variables that aren't completely
     /// captured in Rust 2021 and affect the Drop order of at least one path starting at this variable.
     /// It can also detect when a variable implements a trait, but one of its field does not and
     /// the field is captured by a closure and used with the assumption that said field implements
@@ -3011,7 +3011,7 @@ declare_lint! {
     /// ### Example of drop reorder
     ///
     /// ```rust,compile_fail
-    /// # #![deny(disjoint_capture_migration)]
+    /// # #![deny(rust_2021_incompatible_closure_captures)]
     /// # #![allow(unused)]
     /// struct FancyInteger(i32);
     ///
@@ -3046,7 +3046,7 @@ declare_lint! {
     /// ### Example of auto-trait
     ///
     /// ```rust,compile_fail
-    /// #![deny(disjoint_capture_migration)]
+    /// #![deny(rust_2021_incompatible_closure_captures)]
     /// use std::thread;
     ///
     /// struct Pointer(*mut i32);
@@ -3068,7 +3068,7 @@ declare_lint! {
     /// In the above example, only `fptr.0` is captured in Rust 2021.
     /// The field is of type *mut i32 which doesn't implement Send, making the code invalid as the
     /// field cannot be sent between thread safely.
-    pub DISJOINT_CAPTURE_MIGRATION,
+    pub RUST_2021_INCOMPATIBLE_CLOSURE_CAPTURES,
     Allow,
     "detects closures affected by Rust 2021 changes",
     @future_incompatible = FutureIncompatibleInfo {
@@ -3183,12 +3183,12 @@ declare_lint! {
 }
 
 declare_lint! {
-    /// The `or_patterns_back_compat` lint detects usage of old versions of or-patterns.
+    /// The `rust_2021_incompatible_or_patterns` lint detects usage of old versions of or-patterns.
     ///
     /// ### Example
     ///
     /// ```rust,compile_fail
-    /// #![deny(or_patterns_back_compat)]
+    /// #![deny(rust_2021_incompatible_or_patterns)]
     /// macro_rules! match_any {
     ///     ( $expr:expr , $( $( $pat:pat )|+ => $expr_arm:expr ),+ ) => {
     ///         match $expr {
@@ -3211,7 +3211,7 @@ declare_lint! {
     /// ### Explanation
     ///
     /// In Rust 2021, the pat matcher will match new patterns, which include the | character.
-    pub OR_PATTERNS_BACK_COMPAT,
+    pub RUST_2021_INCOMPATIBLE_OR_PATTERNS,
     Allow,
     "detects usage of old versions of or-patterns",
     @future_incompatible = FutureIncompatibleInfo {
@@ -3221,13 +3221,13 @@ declare_lint! {
 }
 
 declare_lint! {
-    /// The `future_prelude_collision` lint detects the usage of trait methods which are ambiguous
+    /// The `rust_2021_prelude_collisions` lint detects the usage of trait methods which are ambiguous
     /// with traits added to the prelude in future editions.
     ///
     /// ### Example
     ///
     /// ```rust,compile_fail
-    /// #![deny(future_prelude_collision)]
+    /// #![deny(rust_2021_prelude_collisions)]
     ///
     /// trait Foo {
     ///     fn try_into(self) -> Result<String, !>;
@@ -3259,7 +3259,7 @@ declare_lint! {
     ///  is called directly on a type.
     ///
     /// [prelude changes]: https://blog.rust-lang.org/inside-rust/2021/03/04/planning-rust-2021.html#prelude-changes
-    pub FUTURE_PRELUDE_COLLISION,
+    pub RUST_2021_PRELUDE_COLLISIONS,
     Allow,
     "detects the usage of trait methods which are ambiguous with traits added to the \
         prelude in future editions",
@@ -3270,13 +3270,13 @@ declare_lint! {
 }
 
 declare_lint! {
-    /// The `reserved_prefix` lint detects identifiers that will be parsed as a
+    /// The `rust_2021_prefixes_incompatible_syntax` lint detects identifiers that will be parsed as a
     /// prefix instead in Rust 2021.
     ///
     /// ### Example
     ///
     /// ```rust,compile_fail
-    /// #![deny(reserved_prefix)]
+    /// #![deny(rust_2021_prefixes_incompatible_syntax)]
     ///
     /// macro_rules! m {
     ///     (z $x:expr) => ();
@@ -3295,7 +3295,7 @@ declare_lint! {
     ///
     /// This lint suggests to add whitespace between the `z` and `"hey"` tokens
     /// to keep them separated in Rust 2021.
-    pub RESERVED_PREFIX,
+    pub RUST_2021_PREFIXES_INCOMPATIBLE_SYNTAX,
     Allow,
     "identifiers that will be parsed as a prefix in Rust 2021",
     @future_incompatible = FutureIncompatibleInfo {

compiler/rustc_parse/src/lexer/mod.rs

@@ -4,7 +4,7 @@ use rustc_ast::tokenstream::{Spacing, TokenStream};
 use rustc_errors::{error_code, Applicability, DiagnosticBuilder, FatalError, PResult};
 use rustc_lexer::unescape::{self, Mode};
 use rustc_lexer::{Base, DocStyle, RawStrError};
-use rustc_session::lint::builtin::RESERVED_PREFIX;
+use rustc_session::lint::builtin::RUST_2021_PREFIXES_INCOMPATIBLE_SYNTAX;
 use rustc_session::lint::BuiltinLintDiagnostics;
 use rustc_session::parse::ParseSess;
 use rustc_span::symbol::{sym, Symbol};
@@ -526,7 +526,7 @@ impl<'a> StringReader<'a> {
         } else {
             // Before Rust 2021, only emit a lint for migration.
             self.sess.buffer_lint_with_diagnostic(
-                &RESERVED_PREFIX,
+                &RUST_2021_PREFIXES_INCOMPATIBLE_SYNTAX,
                 prefix_span,
                 ast::CRATE_NODE_ID,
                 &msg,

compiler/rustc_typeck/src/check/method/prelude2021.rs

@@ -5,7 +5,7 @@ use rustc_ast::Mutability;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_middle::ty::{Ref, Ty};
-use rustc_session::lint::builtin::FUTURE_PRELUDE_COLLISION;
+use rustc_session::lint::builtin::RUST_2021_PRELUDE_COLLISIONS;
 use rustc_span::symbol::kw::Underscore;
 use rustc_span::symbol::{sym, Ident};
 use rustc_span::Span;
@@ -67,7 +67,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // Inherent impls only require not relying on autoref and autoderef in order to
             // ensure that the trait implementation won't be used
             self.tcx.struct_span_lint_hir(
-                FUTURE_PRELUDE_COLLISION,
+                RUST_2021_PRELUDE_COLLISIONS,
                 self_expr.hir_id,
                 self_expr.span,
                 |lint| {
@@ -128,7 +128,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // trait implementations require full disambiguation to not clash with the new prelude
             // additions (i.e. convert from dot-call to fully-qualified call)
             self.tcx.struct_span_lint_hir(
-                FUTURE_PRELUDE_COLLISION,
+                RUST_2021_PRELUDE_COLLISIONS,
                 call_expr.hir_id,
                 call_expr.span,
                 |lint| {
@@ -212,7 +212,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             return;
         }
 
-        self.tcx.struct_span_lint_hir(FUTURE_PRELUDE_COLLISION, expr_id, span, |lint| {
+        self.tcx.struct_span_lint_hir(RUST_2021_PRELUDE_COLLISIONS, expr_id, span, |lint| {
             // "type" refers to either a type or, more likely, a trait from which
             // the associated function or method is from.
             let trait_path = self.trait_path_or_bare_name(span, expr_id, pick.item.container.id());

compiler/rustc_typeck/src/check/upvar.rs

@@ -171,7 +171,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         let closure_hir_id = self.tcx.hir().local_def_id_to_hir_id(local_def_id);
 
-        if should_do_disjoint_capture_migration_analysis(self.tcx, closure_hir_id) {
+        if should_do_rust_2021_incompatible_closure_captures_analysis(self.tcx, closure_hir_id) {
             self.perform_2229_migration_anaysis(closure_def_id, body_id, capture_clause, span);
         }
 
@@ -503,7 +503,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let local_def_id = closure_def_id.expect_local();
             let closure_hir_id = self.tcx.hir().local_def_id_to_hir_id(local_def_id);
             self.tcx.struct_span_lint_hir(
-                lint::builtin::DISJOINT_CAPTURE_MIGRATION,
+                lint::builtin::RUST_2021_INCOMPATIBLE_CLOSURE_CAPTURES,
                 closure_hir_id,
                 span,
                 |lint| {
@@ -1820,8 +1820,12 @@ fn var_name(tcx: TyCtxt<'_>, var_hir_id: hir::HirId) -> Symbol {
     tcx.hir().name(var_hir_id)
 }
 
-fn should_do_disjoint_capture_migration_analysis(tcx: TyCtxt<'_>, closure_id: hir::HirId) -> bool {
+fn should_do_rust_2021_incompatible_closure_captures_analysis(
-    let (level, _) = tcx.lint_level_at_node(lint::builtin::DISJOINT_CAPTURE_MIGRATION, closure_id);
+    tcx: TyCtxt<'_>,
+    closure_id: hir::HirId,
+) -> bool {
+    let (level, _) =
+        tcx.lint_level_at_node(lint::builtin::RUST_2021_INCOMPATIBLE_CLOSURE_CAPTURES, closure_id);
 
     !matches!(level, lint::Level::Allow)
 }

library/core/src/lib.rs

@@ -164,7 +164,8 @@
 #![feature(no_niche)] // rust-lang/rust#68303
 #![feature(no_coverage)] // rust-lang/rust#84605
 #![deny(unsafe_op_in_unsafe_fn)]
-#![deny(or_patterns_back_compat)]
+#![cfg_attr(bootstrap, deny(or_patterns_back_compat))]
+#![cfg_attr(not(bootstrap), deny(rust_2021_incompatible_or_patterns))]
 
 // allow using `core::` in intra-doc links
 #[allow(unused_extern_crates)]

library/core/src/num/int_macros.rs

@@ -1744,6 +1744,194 @@ macro_rules! int_impl {
             }
         }
 
+        /// Returns the logarithm of the number with respect to an arbitrary base.
+        ///
+        /// This method may not be optimized owing to implementation details;
+        /// `log2` can produce results more efficiently for base 2, and `log10`
+        /// can produce results more efficiently for base 10.
+        ///
+        /// # Panics
+        ///
+        /// When the number is zero, or if the base is not at least 2; it
+        /// panics in debug mode and the return value is wrapped to 0 in release
+        /// mode (the only situation in which the method can return 0).
+        ///
+        /// # Examples
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".log(5), 1);")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        #[track_caller]
+        #[rustc_inherit_overflow_checks]
+        #[allow(arithmetic_overflow)]
+        pub const fn log(self, base: Self) -> Self {
+            match self.checked_log(base) {
+                Some(n) => n,
+                None => {
+                    // In debug builds, trigger a panic on None.
+                    // This should optimize completely out in release builds.
+                    let _ = Self::MAX + 1;
+
+                    0
+                },
+            }
+        }
+
+        /// Returns the base 2 logarithm of the number.
+        ///
+        /// # Panics
+        ///
+        /// When the number is zero it panics in debug mode and the return value
+        /// is wrapped to 0 in release mode (the only situation in which the
+        /// method can return 0).
+        ///
+        /// # Examples
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".log2(), 1);")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        #[track_caller]
+        #[rustc_inherit_overflow_checks]
+        #[allow(arithmetic_overflow)]
+        pub const fn log2(self) -> Self {
+            match self.checked_log2() {
+                Some(n) => n,
+                None => {
+                    // In debug builds, trigger a panic on None.
+                    // This should optimize completely out in release builds.
+                    let _ = Self::MAX + 1;
+
+                    0
+                },
+            }
+        }
+
+        /// Returns the base 10 logarithm of the number.
+        ///
+        /// # Panics
+        ///
+        /// When the number is zero it panics in debug mode and the return value
+        /// is wrapped to 0 in release mode (the only situation in which the
+        /// method can return 0).
+        ///
+        /// # Example
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".log10(), 1);")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        #[track_caller]
+        #[rustc_inherit_overflow_checks]
+        #[allow(arithmetic_overflow)]
+        pub const fn log10(self) -> Self {
+            match self.checked_log10() {
+                Some(n) => n,
+                None => {
+                    // In debug builds, trigger a panic on None.
+                    // This should optimize completely out in release builds.
+                    let _ = Self::MAX + 1;
+
+                    0
+                },
+            }
+        }
+
+        /// Returns the logarithm of the number with respect to an arbitrary base.
+        ///
+        /// Returns `None` if the number is negative or zero, or if the base is not at least 2.
+        ///
+        /// This method may not be optimized owing to implementation details;
+        /// `checked_log2` can produce results more efficiently for base 2, and
+        /// `checked_log10` can produce results more efficiently for base 10.
+        ///
+        /// # Examples
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_log(5), Some(1));")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        pub const fn checked_log(self, base: Self) -> Option<Self> {
+            if self <= 0 || base <= 1 {
+                None
+            } else {
+                let mut n = 0;
+                let mut r = self;
+
+                // Optimization for 128 bit wide integers.
+                if Self::BITS == 128 {
+                    let b = Self::log2(self) / (Self::log2(base) + 1);
+                    n += b;
+                    r /= base.pow(b as u32);
+                }
+
+                while r >= base {
+                    r /= base;
+                    n += 1;
+                }
+                Some(n)
+            }
+        }
+
+        /// Returns the base 2 logarithm of the number.
+        ///
+        /// Returns `None` if the number is negative or zero.
+        ///
+        /// # Examples
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_log2(), Some(1));")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        pub const fn checked_log2(self) -> Option<Self> {
+            if self <= 0 {
+                None
+            } else {
+                // SAFETY: We just checked that this number is positive
+                let log = (Self::BITS - 1) as Self - unsafe { intrinsics::ctlz_nonzero(self) };
+                Some(log)
+            }
+        }
+
+        /// Returns the base 10 logarithm of the number.
+        ///
+        /// Returns `None` if the number is negative or zero.
+        ///
+        /// # Example
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_log10(), Some(1));")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        pub const fn checked_log10(self) -> Option<Self> {
+            self.checked_log(10)
+        }
+
         /// Computes the absolute value of `self`.
         ///
         /// # Overflow behavior

library/core/src/num/uint_macros.rs

@@ -634,6 +634,194 @@ macro_rules! uint_impl {
             }
         }
 
+        /// Returns the logarithm of the number with respect to an arbitrary base.
+        ///
+        /// This method may not be optimized owing to implementation details;
+        /// `log2` can produce results more efficiently for base 2, and `log10`
+        /// can produce results more efficiently for base 10.
+        ///
+        /// # Panics
+        ///
+        /// When the number is negative, zero, or if the base is not at least 2;
+        /// it panics in debug mode and the return value is wrapped to 0 in
+        /// release mode (the only situation in which the method can return 0).
+        ///
+        /// # Examples
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".log(5), 1);")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        #[track_caller]
+        #[rustc_inherit_overflow_checks]
+        #[allow(arithmetic_overflow)]
+        pub const fn log(self, base: Self) -> Self {
+            match self.checked_log(base) {
+                Some(n) => n,
+                None => {
+                    // In debug builds, trigger a panic on None.
+                    // This should optimize completely out in release builds.
+                    let _ = Self::MAX + 1;
+
+                    0
+                },
+            }
+        }
+
+        /// Returns the base 2 logarithm of the number.
+        ///
+        /// # Panics
+        ///
+        /// When the number is negative or zero it panics in debug mode and
+        /// the return value is wrapped to 0 in release mode (the only situation in
+        /// which the method can return 0).
+        ///
+        /// # Examples
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".log2(), 1);")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        #[track_caller]
+        #[rustc_inherit_overflow_checks]
+        #[allow(arithmetic_overflow)]
+        pub const fn log2(self) -> Self {
+            match self.checked_log2() {
+                Some(n) => n,
+                None => {
+                    // In debug builds, trigger a panic on None.
+                    // This should optimize completely out in release builds.
+                    let _ = Self::MAX + 1;
+
+                    0
+                },
+            }
+        }
+
+        /// Returns the base 10 logarithm of the number.
+        ///
+        /// # Panics
+        ///
+        /// When the number is negative or zero it panics in debug mode and the
+        /// return value is wrapped to 0 in release mode (the only situation in
+        /// which the method can return 0).
+        ///
+        /// # Example
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".log10(), 1);")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        #[track_caller]
+        #[rustc_inherit_overflow_checks]
+        #[allow(arithmetic_overflow)]
+        pub const fn log10(self) -> Self {
+            match self.checked_log10() {
+                Some(n) => n,
+                None => {
+                    // In debug builds, trigger a panic on None.
+                    // This should optimize completely out in release builds.
+                    let _ = Self::MAX + 1;
+
+                    0
+                },
+            }
+        }
+
+        /// Returns the logarithm of the number with respect to an arbitrary base.
+        ///
+        /// Returns `None` if the number is zero, or if the base is not at least 2.
+        ///
+        /// This method may not be optimized owing to implementation details;
+        /// `checked_log2` can produce results more efficiently for base 2, and
+        /// `checked_log10` can produce results more efficiently for base 10.
+        ///
+        /// # Examples
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".checked_log(5), Some(1));")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        pub const fn checked_log(self, base: Self) -> Option<Self> {
+            if self <= 0 || base <= 1 {
+                None
+            } else {
+                let mut n = 0;
+                let mut r = self;
+
+                // Optimization for 128 bit wide integers.
+                if Self::BITS == 128 {
+                    let b = Self::log2(self) / (Self::log2(base) + 1);
+                    n += b;
+                    r /= base.pow(b as u32);
+                }
+
+                while r >= base {
+                    r /= base;
+                    n += 1;
+                }
+                Some(n)
+            }
+        }
+
+        /// Returns the base 2 logarithm of the number.
+        ///
+        /// Returns `None` if the number is zero.
+        ///
+        /// # Examples
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(2", stringify!($SelfT), ".checked_log2(), Some(1));")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        pub const fn checked_log2(self) -> Option<Self> {
+            if self <= 0 {
+                None
+            } else {
+                // SAFETY: We just checked that this number is positive
+                let log = (Self::BITS - 1) as Self - unsafe { intrinsics::ctlz_nonzero(self) };
+                Some(log)
+            }
+        }
+
+        /// Returns the base 10 logarithm of the number.
+        ///
+        /// Returns `None` if the number is zero.
+        ///
+        /// # Examples
+        ///
+        /// ```
+        /// #![feature(int_log)]
+        #[doc = concat!("assert_eq!(10", stringify!($SelfT), ".checked_log10(), Some(1));")]
+        /// ```
+        #[unstable(feature = "int_log", issue = "70887")]
+        #[must_use = "this returns the result of the operation, \
+                        without modifying the original"]
+        #[inline]
+        pub const fn checked_log10(self) -> Option<Self> {
+            self.checked_log(10)
+        }
+
         /// Checked negation. Computes `-self`, returning `None` unless `self ==
         /// 0`.
         ///

library/core/src/sync/atomic.rs

@@ -2648,7 +2648,11 @@ unsafe fn atomic_umin<T: Copy>(dst: *mut T, val: T, order: Ordering) -> T {
 ///
 ///     pub fn lock(&self) {
 ///         // Wait until the old value is `false`.
-///         while self.flag.compare_and_swap(false, true, Ordering::Relaxed) != false {}
+///         while self
+///             .flag
+///             .compare_exchange_weak(false, true, Ordering::Relaxed, Ordering::Relaxed)
+///             .is_err()
+///         {}
 ///         // This fence synchronizes-with store in `unlock`.
 ///         fence(Ordering::Acquire);
 ///     }
@@ -2710,7 +2714,7 @@ pub fn fence(order: Ordering) {
 /// Without `compiler_fence`, the `assert_eq!` in following code
 /// is *not* guaranteed to succeed, despite everything happening in a single thread.
 /// To see why, remember that the compiler is free to swap the stores to
-/// `IMPORTANT_VARIABLE` and `IS_READ` since they are both
+/// `IMPORTANT_VARIABLE` and `IS_READY` since they are both
 /// `Ordering::Relaxed`. If it does, and the signal handler is invoked right
 /// after `IS_READY` is updated, then the signal handler will see
 /// `IS_READY=1`, but `IMPORTANT_VARIABLE=0`.

library/core/tests/lib.rs

@@ -44,6 +44,7 @@
 #![feature(try_trait_v2)]
 #![feature(slice_internals)]
 #![feature(slice_partition_dedup)]
+#![feature(int_log)]
 #![feature(iter_advance_by)]
 #![feature(iter_partition_in_place)]
 #![feature(iter_intersperse)]

library/core/tests/manually_drop.rs

@@ -2,6 +2,7 @@ use core::mem::ManuallyDrop;
 
 #[test]
 fn smoke() {
+    #[derive(Clone)]
     struct TypeWithDrop;
     impl Drop for TypeWithDrop {
         fn drop(&mut self) {
@@ -16,4 +17,11 @@ fn smoke() {
     let x: Box<ManuallyDrop<[TypeWithDrop]>> =
         Box::new(ManuallyDrop::new([TypeWithDrop, TypeWithDrop]));
     drop(x);
+
+    // test clone and clone_from implementations
+    let mut x = ManuallyDrop::new(TypeWithDrop);
+    let y = x.clone();
+    x.clone_from(&y);
+    drop(x);
+    drop(y);
 }

library/core/tests/num/int_log.rs

@@ -0,0 +1,99 @@
+//! This tests the `Integer::{log,log2,log10}` methods. These tests are in a
+//! separate file because there's both a large number of them, and not all tests
+//! can be run on Android. This is because in Android `log2` uses an imprecise
+//! approximation:https://github.com/rust-lang/rust/blob/4825e12fc9c79954aa0fe18f5521efa6c19c7539/src/libstd/sys/unix/android.rs#L27-L53
+
+#[test]
+fn checked_log() {
+    assert_eq!(999u32.checked_log(10), Some(2));
+    assert_eq!(1000u32.checked_log(10), Some(3));
+    assert_eq!(555u32.checked_log(13), Some(2));
+    assert_eq!(63u32.checked_log(4), Some(2));
+    assert_eq!(64u32.checked_log(4), Some(3));
+    assert_eq!(10460353203u64.checked_log(3), Some(21));
+    assert_eq!(10460353202u64.checked_log(3), Some(20));
+    assert_eq!(147808829414345923316083210206383297601u128.checked_log(3), Some(80));
+    assert_eq!(147808829414345923316083210206383297600u128.checked_log(3), Some(79));
+    assert_eq!(22528399544939174411840147874772641u128.checked_log(19683), Some(8));
+    assert_eq!(22528399544939174411840147874772631i128.checked_log(19683), Some(7));
+
+    assert_eq!(0u8.checked_log(4), None);
+    assert_eq!(0u16.checked_log(4), None);
+    assert_eq!(0i8.checked_log(4), None);
+    assert_eq!(0i16.checked_log(4), None);
+
+    for i in i16::MIN..=0 {
+        assert_eq!(i.checked_log(4), None);
+    }
+    for i in 1..=i16::MAX {
+        assert_eq!(i.checked_log(13), Some((i as f32).log(13.0) as i16));
+    }
+    for i in 1..=u16::MAX {
+        assert_eq!(i.checked_log(13), Some((i as f32).log(13.0) as u16));
+    }
+}
+
+#[test]
+fn checked_log2() {
+    assert_eq!(5u32.checked_log2(), Some(2));
+    assert_eq!(0u64.checked_log2(), None);
+    assert_eq!(128i32.checked_log2(), Some(7));
+    assert_eq!((-55i16).checked_log2(), None);
+
+    assert_eq!(0u8.checked_log2(), None);
+    assert_eq!(0u16.checked_log2(), None);
+    assert_eq!(0i8.checked_log2(), None);
+    assert_eq!(0i16.checked_log2(), None);
+
+    for i in 1..=u8::MAX {
+        assert_eq!(i.checked_log2(), Some((i as f32).log2() as u8));
+    }
+    for i in 1..=u16::MAX {
+        // Guard against Android's imprecise f32::log2 implementation.
+        if i != 8192 && i != 32768 {
+            assert_eq!(i.checked_log2(), Some((i as f32).log2() as u16));
+        }
+    }
+    for i in i8::MIN..=0 {
+        assert_eq!(i.checked_log2(), None);
+    }
+    for i in 1..=i8::MAX {
+        assert_eq!(i.checked_log2(), Some((i as f32).log2() as i8));
+    }
+    for i in i16::MIN..=0 {
+        assert_eq!(i.checked_log2(), None);
+    }
+    for i in 1..=i16::MAX {
+        // Guard against Android's imprecise f32::log2 implementation.
+        if i != 8192 {
+            assert_eq!(i.checked_log2(), Some((i as f32).log2() as i16));
+        }
+    }
+}
+
+// Validate cases that fail on Android's imprecise float log2 implementation.
+#[test]
+#[cfg(not(target_os = "android"))]
+fn checked_log2_not_android() {
+    assert_eq!(8192u16.checked_log2(), Some((8192f32).log2() as u16));
+    assert_eq!(32768u16.checked_log2(), Some((32768f32).log2() as u16));
+    assert_eq!(8192i16.checked_log2(), Some((8192f32).log2() as i16));
+}
+
+#[test]
+fn checked_log10() {
+    assert_eq!(0u8.checked_log10(), None);
+    assert_eq!(0u16.checked_log10(), None);
+    assert_eq!(0i8.checked_log10(), None);
+    assert_eq!(0i16.checked_log10(), None);
+
+    for i in i16::MIN..=0 {
+        assert_eq!(i.checked_log10(), None);
+    }
+    for i in 1..=i16::MAX {
+        assert_eq!(i.checked_log10(), Some((i as f32).log10() as i16));
+    }
+    for i in 1..=u16::MAX {
+        assert_eq!(i.checked_log10(), Some((i as f32).log10() as u16));
+    }
+}

library/core/tests/num/mod.rs

@@ -29,6 +29,7 @@ mod u8;
 mod bignum;
 mod dec2flt;
 mod flt2dec;
+mod int_log;
 mod ops;
 mod wrapping;
 

library/std/src/lib.rs

@@ -278,6 +278,7 @@
 #![feature(hashmap_internals)]
 #![feature(int_error_internals)]
 #![feature(integer_atomics)]
+#![feature(int_log)]
 #![feature(into_future)]
 #![feature(intra_doc_pointers)]
 #![feature(iter_zip)]

library/std/src/thread/mod.rs

@@ -651,22 +651,23 @@ pub fn current() -> Thread {
 
 /// Cooperatively gives up a timeslice to the OS scheduler.
 ///
-/// This is used when the programmer knows that the thread will have nothing
+/// This calls the underlying OS scheduler's yield primitive, signaling
-/// to do for some time, and thus avoid wasting computing time.
+/// that the calling thread is willing to give up its remaining timeslice
+/// so that the OS may schedule other threads on the CPU.
 ///
-/// For example when polling on a resource, it is common to check that it is
+/// A drawback of yielding in a loop is that if the OS does not have any
-/// available, and if not to yield in order to avoid busy waiting.
+/// other ready threads to run on the current CPU, the thread will effectively
+/// busy-wait, which wastes CPU time and energy.
 ///
-/// Thus the pattern of `yield`ing after a failed poll is rather common when
+/// Therefore, when waiting for events of interest, a programmer's first
-/// implementing low-level shared resources or synchronization primitives.
+/// choice should be to use synchronization devices such as [`channel`]s,
+/// [`Condvar`]s, [`Mutex`]es or [`join`] since these primitives are
+/// implemented in a blocking manner, giving up the CPU until the event
+/// of interest has occurred which avoids repeated yielding.
 ///
-/// However programmers will usually prefer to use [`channel`]s, [`Condvar`]s,
+/// `yield_now` should thus be used only rarely, mostly in situations where
-/// [`Mutex`]es or [`join`] for their synchronization routines, as they avoid
+/// repeated polling is required because there is no other suitable way to
-/// thinking about thread scheduling.
+/// learn when an event of interest has occurred.
-///
-/// Note that [`channel`]s for example are implemented using this primitive.
-/// Indeed when you call `send` or `recv`, which are blocking, they will yield
-/// if the channel is not available.
 ///
 /// # Examples
 ///

src/ci/cpu-usage-over-time.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # ignore-tidy-linelength
 
 # This is a small script that we use on CI to collect CPU usage statistics of
@@ -37,7 +37,10 @@ import datetime
 import sys
 import time
 
-if sys.platform == 'linux2':
+# Python 3.3 changed the value of `sys.platform` on Linux from "linux2" to just
+# "linux". We check here with `.startswith` to keep compatibility with older
+# Python versions (especially Python 2.7).
+if sys.platform.startswith('linux'):
     class State:
         def __init__(self):
             with open('/proc/stat', 'r') as file:

src/ci/scripts/collect-cpu-stats.sh

@@ -6,4 +6,4 @@
 set -euo pipefail
 IFS=$'\n\t'
 
-python src/ci/cpu-usage-over-time.py &> cpu-usage.csv &
+python3 src/ci/cpu-usage-over-time.py &> cpu-usage.csv &

src/doc/book

@@ -1 +1 @@
-Subproject commit 55a26488ddefc8433e73a2e8352d70f7a5c7fc2b
+Subproject commit a90f07f1e9a7fc75dc9105a6c6f16d5c13edceb0

src/doc/edition-guide

@@ -1 +1 @@
-Subproject commit c74b2a0d6bf55774cf15d69f05dfe05408b8f81a
+Subproject commit 5d57b3832f8d308a9f478ce0a69799548f27ad4d

src/doc/embedded-book

@@ -1 +1 @@
-Subproject commit cbec77fbd8eea0c13e390dd9eded1ae200e811d1
+Subproject commit 506840eb73b0749336e1d5274e16d6393892ee82

src/doc/nomicon

@@ -1 +1 @@
-Subproject commit b9ca313e687c991223e23e5520529815dc281205
+Subproject commit 7a13537f96af4b9b8e3ea296d6e5c3c7ab72ce9f

src/doc/reference

@@ -1 +1 @@
-Subproject commit d9699fa8f3186440fdaadd703d63d8d42322c176
+Subproject commit ab60513a3a5a0591e237fddff5d027a982648392

src/doc/rust-by-example

@@ -1 +1 @@
-Subproject commit 805e016c5792ad2adabb66e348233067d5ea9f10
+Subproject commit 028f93a61500fe8f746ee7cc6b204ea6c9f42935

src/doc/rustc-dev-guide

@@ -1 +1 @@
-Subproject commit fe34beddb41dea5cb891032512a8d5b842b99696
+Subproject commit 60e282559104035985331645907c3d9f842312c5

src/librustdoc/html/markdown.rs

@@ -1358,7 +1358,10 @@ pub struct IdMap {
 
 fn init_id_map() -> FxHashMap<String, usize> {
     let mut map = FxHashMap::default();
-    // This is the list of IDs used by rustdoc templates.
+    // This is the list of IDs used in Javascript.
+    map.insert("help".to_owned(), 1);
+    // This is the list of IDs used in HTML generated in Rust (including the ones
+    // used in tera template files).
     map.insert("mainThemeStyle".to_owned(), 1);
     map.insert("themeStyle".to_owned(), 1);
     map.insert("theme-picker".to_owned(), 1);
@@ -1375,14 +1378,14 @@ fn init_id_map() -> FxHashMap<String, usize> {
     map.insert("rustdoc-vars".to_owned(), 1);
     map.insert("sidebar-vars".to_owned(), 1);
     map.insert("copy-path".to_owned(), 1);
-    map.insert("help".to_owned(), 1);
     map.insert("TOC".to_owned(), 1);
-    map.insert("render-detail".to_owned(), 1);
+    // This is the list of IDs used by rustdoc sections (but still generated by
-    // This is the list of IDs used by rustdoc sections.
+    // rustdoc).
     map.insert("fields".to_owned(), 1);
     map.insert("variants".to_owned(), 1);
     map.insert("implementors-list".to_owned(), 1);
     map.insert("synthetic-implementors-list".to_owned(), 1);
+    map.insert("foreign-impls".to_owned(), 1);
     map.insert("implementations".to_owned(), 1);
     map.insert("trait-implementations".to_owned(), 1);
     map.insert("synthetic-implementations".to_owned(), 1);
@@ -1393,6 +1396,10 @@ fn init_id_map() -> FxHashMap<String, usize> {
     map.insert("provided-methods".to_owned(), 1);
     map.insert("implementors".to_owned(), 1);
     map.insert("synthetic-implementors".to_owned(), 1);
+    map.insert("trait-implementations-list".to_owned(), 1);
+    map.insert("synthetic-implementations-list".to_owned(), 1);
+    map.insert("blanket-implementations-list".to_owned(), 1);
+    map.insert("deref-methods".to_owned(), 1);
     map
 }
 

src/test/ui/closures/2229_closure_analysis/migrations/auto_traits.fixed

@@ -1,10 +1,10 @@
 // run-rustfix
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 
 use std::thread;
 
 /* Test Send Trait Migration */
-struct SendPointer (*mut i32);
+struct SendPointer(*mut i32);
 unsafe impl Send for SendPointer {}
 
 fn test_send_trait() {
@@ -18,8 +18,8 @@ fn test_send_trait() {
 }
 
 /* Test Sync Trait Migration */
-struct CustomInt (*mut i32);
+struct CustomInt(*mut i32);
-struct SyncPointer (CustomInt);
+struct SyncPointer(CustomInt);
 unsafe impl Sync for SyncPointer {}
 unsafe impl Send for CustomInt {}
 
@@ -38,7 +38,7 @@ fn test_sync_trait() {
 struct S(String);
 struct T(i32);
 
-struct U(S,T);
+struct U(S, T);
 
 impl Clone for U {
     fn clone(&self) -> Self {

src/test/ui/closures/2229_closure_analysis/migrations/auto_traits.rs

@@ -1,10 +1,10 @@
 // run-rustfix
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 
 use std::thread;
 
 /* Test Send Trait Migration */
-struct SendPointer (*mut i32);
+struct SendPointer(*mut i32);
 unsafe impl Send for SendPointer {}
 
 fn test_send_trait() {
@@ -18,8 +18,8 @@ fn test_send_trait() {
 }
 
 /* Test Sync Trait Migration */
-struct CustomInt (*mut i32);
+struct CustomInt(*mut i32);
-struct SyncPointer (CustomInt);
+struct SyncPointer(CustomInt);
 unsafe impl Sync for SyncPointer {}
 unsafe impl Send for CustomInt {}
 
@@ -38,7 +38,7 @@ fn test_sync_trait() {
 struct S(String);
 struct T(i32);
 
-struct U(S,T);
+struct U(S, T);
 
 impl Clone for U {
     fn clone(&self) -> Self {

src/test/ui/closures/2229_closure_analysis/migrations/auto_traits.stderr

@@ -12,8 +12,8 @@ LL | |     });
 note: the lint level is defined here
   --> $DIR/auto_traits.rs:2:9
    |
-LL | #![deny(disjoint_capture_migration)]
+LL | #![deny(rust_2021_incompatible_closure_captures)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/disjoint-capture-in-closures.html>
 help: add a dummy let to cause `fptr` to be fully captured
    |

src/test/ui/closures/2229_closure_analysis/migrations/insignificant_drop.fixed

@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 //~^ NOTE: the lint level is defined here
 
 // Test cases for types that implement a insignificant drop (stlib defined)

src/test/ui/closures/2229_closure_analysis/migrations/insignificant_drop.rs

@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 //~^ NOTE: the lint level is defined here
 
 // Test cases for types that implement a insignificant drop (stlib defined)

src/test/ui/closures/2229_closure_analysis/migrations/insignificant_drop.stderr

@@ -14,8 +14,8 @@ LL | |     };
 note: the lint level is defined here
   --> $DIR/insignificant_drop.rs:3:9
    |
-LL | #![deny(disjoint_capture_migration)]
+LL | #![deny(rust_2021_incompatible_closure_captures)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/disjoint-capture-in-closures.html>
 help: add a dummy let to cause `t`, `t1`, `t2` to be fully captured
    |

src/test/ui/closures/2229_closure_analysis/migrations/insignificant_drop_attr_migrations.fixed

@@ -1,8 +1,7 @@
 // run-rustfix
 
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 //~^ NOTE: the lint level is defined here
-
 #![feature(rustc_attrs)]
 #![allow(unused)]
 

src/test/ui/closures/2229_closure_analysis/migrations/insignificant_drop_attr_migrations.rs

@@ -1,8 +1,7 @@
 // run-rustfix
 
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 //~^ NOTE: the lint level is defined here
-
 #![feature(rustc_attrs)]
 #![allow(unused)]
 

src/test/ui/closures/2229_closure_analysis/migrations/insignificant_drop_attr_migrations.stderr

@@ -1,5 +1,5 @@
 error: drop order will change in Rust 2021
-  --> $DIR/insignificant_drop_attr_migrations.rs:38:13
+  --> $DIR/insignificant_drop_attr_migrations.rs:37:13
    |
 LL |       let c = || {
    |  _____________^
@@ -13,8 +13,8 @@ LL | |     };
 note: the lint level is defined here
   --> $DIR/insignificant_drop_attr_migrations.rs:3:9
    |
-LL | #![deny(disjoint_capture_migration)]
+LL | #![deny(rust_2021_incompatible_closure_captures)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/disjoint-capture-in-closures.html>
 help: add a dummy let to cause `t` to be fully captured
    |
@@ -27,7 +27,7 @@ LL |     };
    |
 
 error: drop order will change in Rust 2021
-  --> $DIR/insignificant_drop_attr_migrations.rs:56:13
+  --> $DIR/insignificant_drop_attr_migrations.rs:55:13
    |
 LL |       let c = move || {
    |  _____________^

src/test/ui/closures/2229_closure_analysis/migrations/insignificant_drop_attr_no_migrations.rs

@@ -1,6 +1,6 @@
 // run-pass
 
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 #![feature(rustc_attrs)]
 #![allow(unused)]
 

src/test/ui/closures/2229_closure_analysis/migrations/issue-78720.rs

@@ -1,6 +1,6 @@
 // run-pass
 
-#![warn(disjoint_capture_migration)]
+#![warn(rust_2021_incompatible_closure_captures)]
 
 fn main() {
     if let a = "" {

src/test/ui/closures/2229_closure_analysis/migrations/migrations_rustfix.fixed

@@ -1,5 +1,5 @@
 // run-rustfix
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 //~^ NOTE: the lint level is defined here
 
 // Test the two possible cases for automated migartion using rustfix

src/test/ui/closures/2229_closure_analysis/migrations/migrations_rustfix.rs

@@ -1,5 +1,5 @@
 // run-rustfix
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 //~^ NOTE: the lint level is defined here
 
 // Test the two possible cases for automated migartion using rustfix

src/test/ui/closures/2229_closure_analysis/migrations/migrations_rustfix.stderr

@@ -13,8 +13,8 @@ LL | |     };
 note: the lint level is defined here
   --> $DIR/migrations_rustfix.rs:2:9
    |
-LL | #![deny(disjoint_capture_migration)]
+LL | #![deny(rust_2021_incompatible_closure_captures)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/disjoint-capture-in-closures.html>
 help: add a dummy let to cause `t` to be fully captured
    |

src/test/ui/closures/2229_closure_analysis/migrations/mir_calls_to_shims.fixed

@@ -1,16 +1,20 @@
 // run-rustfix
 
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 // ignore-wasm32-bare compiled with panic=abort by default
-
 #![feature(fn_traits)]
 #![feature(never_type)]
 
 use std::panic;
 
-fn foo_diverges() -> ! { panic!() }
+fn foo_diverges() -> ! {
+    panic!()
+}
 
-fn assert_panics<F>(f: F) where F: FnOnce() {
+fn assert_panics<F>(f: F)
+where
+    F: FnOnce(),
+{
     let f = panic::AssertUnwindSafe(f);
     let result = panic::catch_unwind(move || { let _ = &f; 
         //~^ ERROR: `UnwindSafe`, `RefUnwindSafe` trait implementation
@@ -23,7 +27,8 @@ fn assert_panics<F>(f: F) where F: FnOnce() {
 }
 
 fn test_fn_ptr_panic<T>(mut t: T)
-    where T: Fn() -> !
+where
+    T: Fn() -> !,
 {
     let as_fn = <T as Fn<()>>::call;
     assert_panics(|| as_fn(&t, ()));

src/test/ui/closures/2229_closure_analysis/migrations/mir_calls_to_shims.rs

@@ -1,16 +1,20 @@
 // run-rustfix
 
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 // ignore-wasm32-bare compiled with panic=abort by default
-
 #![feature(fn_traits)]
 #![feature(never_type)]
 
 use std::panic;
 
-fn foo_diverges() -> ! { panic!() }
+fn foo_diverges() -> ! {
+    panic!()
+}
 
-fn assert_panics<F>(f: F) where F: FnOnce() {
+fn assert_panics<F>(f: F)
+where
+    F: FnOnce(),
+{
     let f = panic::AssertUnwindSafe(f);
     let result = panic::catch_unwind(move || {
         //~^ ERROR: `UnwindSafe`, `RefUnwindSafe` trait implementation
@@ -23,7 +27,8 @@ fn assert_panics<F>(f: F) where F: FnOnce() {
 }
 
 fn test_fn_ptr_panic<T>(mut t: T)
-    where T: Fn() -> !
+where
+    T: Fn() -> !,
 {
     let as_fn = <T as Fn<()>>::call;
     assert_panics(|| as_fn(&t, ()));

src/test/ui/closures/2229_closure_analysis/migrations/mir_calls_to_shims.stderr

@@ -1,5 +1,5 @@
 error: `UnwindSafe`, `RefUnwindSafe` trait implementation will change in Rust 2021
-  --> $DIR/mir_calls_to_shims.rs:15:38
+  --> $DIR/mir_calls_to_shims.rs:19:38
    |
 LL |       let result = panic::catch_unwind(move || {
    |  ______________________________________^
@@ -12,8 +12,8 @@ LL | |     });
 note: the lint level is defined here
   --> $DIR/mir_calls_to_shims.rs:3:9
    |
-LL | #![deny(disjoint_capture_migration)]
+LL | #![deny(rust_2021_incompatible_closure_captures)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/disjoint-capture-in-closures.html>
 help: add a dummy let to cause `f` to be fully captured
    |

src/test/ui/closures/2229_closure_analysis/migrations/no_migrations.rs

@@ -2,8 +2,7 @@
 
 // Set of test cases that don't need migrations
 
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
-
 
 // Copy types as copied by the closure instead of being moved into the closure
 // Therefore their drop order isn't tied to the closure and won't be requiring any
@@ -53,7 +52,6 @@ fn test4_insignificant_drop_non_drop_aggregate() {
     c();
 }
 
-
 struct Foo(i32);
 impl Drop for Foo {
     fn drop(&mut self) {
@@ -80,5 +78,4 @@ fn main() {
     test3_only_copy_types_move_closure();
     test4_insignificant_drop_non_drop_aggregate();
     test5_significant_drop_non_drop_aggregate();
-
 }

src/test/ui/closures/2229_closure_analysis/migrations/old_name.rs

@@ -0,0 +1,9 @@
+// check-pass
+
+// Ensure that the old name for `rust_2021_incompatible_closure_captures` is still
+// accepted by the compiler
+
+#![allow(disjoint_capture_migration)]
+//~^ WARN lint `disjoint_capture_migration` has been renamed
+
+fn main() {}

src/test/ui/closures/2229_closure_analysis/migrations/old_name.stderr

@@ -0,0 +1,10 @@
+warning: lint `disjoint_capture_migration` has been renamed to `rust_2021_incompatible_closure_captures`
+  --> $DIR/old_name.rs:6:10
+   |
+LL | #![allow(disjoint_capture_migration)]
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `rust_2021_incompatible_closure_captures`
+   |
+   = note: `#[warn(renamed_and_removed_lints)]` on by default
+
+warning: 1 warning emitted
+

src/test/ui/closures/2229_closure_analysis/migrations/precise.fixed

@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 
 #[derive(Debug)]
 struct Foo(i32);
@@ -28,8 +28,7 @@ fn test_precise_analysis_drop_paths_not_captured_by_move() {
 
 struct S;
 impl Drop for S {
-    fn drop(&mut self) {
+    fn drop(&mut self) {}
-    }
 }
 
 struct T(S, S);

src/test/ui/closures/2229_closure_analysis/migrations/precise.rs

@@ -1,6 +1,6 @@
 // run-rustfix
 
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 
 #[derive(Debug)]
 struct Foo(i32);
@@ -28,8 +28,7 @@ fn test_precise_analysis_drop_paths_not_captured_by_move() {
 
 struct S;
 impl Drop for S {
-    fn drop(&mut self) {
+    fn drop(&mut self) {}
-    }
 }
 
 struct T(S, S);

src/test/ui/closures/2229_closure_analysis/migrations/precise.stderr

@@ -13,8 +13,8 @@ LL | |     };
 note: the lint level is defined here
   --> $DIR/precise.rs:3:9
    |
-LL | #![deny(disjoint_capture_migration)]
+LL | #![deny(rust_2021_incompatible_closure_captures)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/disjoint-capture-in-closures.html>
 help: add a dummy let to cause `t` to be fully captured
    |
@@ -27,7 +27,7 @@ LL |     };
    |
 
 error: drop order will change in Rust 2021
-  --> $DIR/precise.rs:42:13
+  --> $DIR/precise.rs:41:13
    |
 LL |       let c = || {
    |  _____________^

src/test/ui/closures/2229_closure_analysis/migrations/precise_no_migrations.rs

@@ -1,6 +1,6 @@
 // run-pass
 
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 
 #[derive(Debug)]
 struct Foo(i32);
@@ -73,8 +73,7 @@ fn test_precise_analysis_parent_captured_2() {
 
 struct S;
 impl Drop for S {
-    fn drop(&mut self) {
+    fn drop(&mut self) {}
-    }
 }
 
 struct T(S, S);

src/test/ui/closures/2229_closure_analysis/migrations/significant_drop.fixed

@@ -1,5 +1,5 @@
 // run-rustfix
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 //~^ NOTE: the lint level is defined here
 
 // Test cases for types that implement a significant drop (user defined)

src/test/ui/closures/2229_closure_analysis/migrations/significant_drop.rs

@@ -1,5 +1,5 @@
 // run-rustfix
-#![deny(disjoint_capture_migration)]
+#![deny(rust_2021_incompatible_closure_captures)]
 //~^ NOTE: the lint level is defined here
 
 // Test cases for types that implement a significant drop (user defined)

src/test/ui/closures/2229_closure_analysis/migrations/significant_drop.stderr

@@ -14,8 +14,8 @@ LL | |     };
 note: the lint level is defined here
   --> $DIR/significant_drop.rs:2:9
    |
-LL | #![deny(disjoint_capture_migration)]
+LL | #![deny(rust_2021_incompatible_closure_captures)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/disjoint-capture-in-closures.html>
 help: add a dummy let to cause `t`, `t1`, `t2` to be fully captured
    |

src/test/ui/consts/const-eval/const_panic.rs

@@ -1,5 +1,5 @@
 #![feature(const_panic)]
-#![allow(non_fmt_panic)]
+#![allow(non_fmt_panics)]
 #![crate_type = "lib"]
 
 const MSG: &str = "hello";

src/test/ui/fmt/format-args-capture.rs

@@ -16,13 +16,13 @@ fn main() {
 
 fn named_argument_takes_precedence_to_captured() {
     let foo = "captured";
-    let s = format!("{foo}", foo="named");
+    let s = format!("{foo}", foo = "named");
     assert_eq!(&s, "named");
 
-    let s = format!("{foo}-{foo}-{foo}", foo="named");
+    let s = format!("{foo}-{foo}-{foo}", foo = "named");
     assert_eq!(&s, "named-named-named");
 
-    let s = format!("{}-{bar}-{foo}", "positional", bar="named");
+    let s = format!("{}-{bar}-{foo}", "positional", bar = "named");
     assert_eq!(&s, "positional-named-captured");
 }
 
@@ -42,10 +42,11 @@ fn panic_with_single_argument_does_not_get_formatted() {
     // RFC #2795 suggests that this may need to change so that captured arguments are formatted.
     // For stability reasons this will need to part of an edition change.
 
-    #[allow(non_fmt_panic)]
+    #[allow(non_fmt_panics)]
     let msg = std::panic::catch_unwind(|| {
         panic!("{foo}");
-    }).unwrap_err();
+    })
+    .unwrap_err();
 
     assert_eq!(msg.downcast_ref::<&str>(), Some(&"{foo}"))
 }
@@ -55,8 +56,9 @@ fn panic_with_multiple_arguments_is_formatted() {
     let foo = "captured";
 
     let msg = std::panic::catch_unwind(|| {
-        panic!("{}-{bar}-{foo}", "positional", bar="named");
+        panic!("{}-{bar}-{foo}", "positional", bar = "named");
-    }).unwrap_err();
+    })
+    .unwrap_err();
 
     assert_eq!(msg.downcast_ref::<String>(), Some(&"positional-named-captured".to_string()))
 }

src/test/ui/macros/assert-macro-owned.rs

@@ -2,7 +2,7 @@
 // error-pattern:panicked at 'test-assert-owned'
 // ignore-emscripten no processes
 
-#![allow(non_fmt_panic)]
+#![allow(non_fmt_panics)]
 
 fn main() {
     assert!(false, "test-assert-owned".to_string());

src/test/ui/macros/macro-comma-behavior-rpass.rs

@@ -14,11 +14,12 @@
 // revisions: std core
 
 // ignore-wasm32-bare compiled with panic=abort by default
-
 #![cfg_attr(core, no_std)]
 
-#[cfg(std)] use std::fmt;
+#[cfg(core)]
-#[cfg(core)] use core::fmt;
+use core::fmt;
+#[cfg(std)]
+use std::fmt;
 
 // an easy mistake in the implementation of 'assert!'
 // would cause this to say "explicit panic"
@@ -57,7 +58,7 @@ fn writeln_1arg() {
 //
 // (Example: Issue #48042)
 #[test]
-#[allow(non_fmt_panic)]
+#[allow(non_fmt_panics)]
 fn to_format_or_not_to_format() {
     // ("{}" is the easiest string to test because if this gets
     // sent to format_args!, it'll simply fail to compile.
@@ -80,13 +81,17 @@ fn to_format_or_not_to_format() {
     // format!("{}",); // see check-fail
     // format_args!("{}",); // see check-fail
 
-    if falsum() { panic!("{}",); }
+    if falsum() {
+        panic!("{}",);
+    }
 
     // print!("{}",); // see check-fail
     // println!("{}",); // see check-fail
     // unimplemented!("{}",); // see check-fail
 
-    if falsum() { unreachable!("{}",); }
+    if falsum() {
+        unreachable!("{}",);
+    }
 
     // write!(&mut stdout, "{}",); // see check-fail
     // writeln!(&mut stdout, "{}",); // see check-fail

src/test/ui/macros/macro-or-patterns-back-compat.fixed

@@ -1,7 +1,7 @@
 // run-rustfix
 // aux-build:or-pattern.rs
 
-#![deny(or_patterns_back_compat)]
+#![deny(rust_2021_incompatible_or_patterns)]
 #![allow(unused_macros)]
 
 #[macro_use]

src/test/ui/macros/macro-or-patterns-back-compat.rs

@@ -1,7 +1,7 @@
 // run-rustfix
 // aux-build:or-pattern.rs
 
-#![deny(or_patterns_back_compat)]
+#![deny(rust_2021_incompatible_or_patterns)]
 #![allow(unused_macros)]
 
 #[macro_use]

src/test/ui/macros/macro-or-patterns-back-compat.stderr

@@ -7,8 +7,8 @@ LL | macro_rules! foo { ($x:pat | $y:pat) => {} }
 note: the lint level is defined here
   --> $DIR/macro-or-patterns-back-compat.rs:4:9
    |
-LL | #![deny(or_patterns_back_compat)]
+LL | #![deny(rust_2021_incompatible_or_patterns)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see issue #84869 <https://github.com/rust-lang/rust/issues/84869>
 

src/test/ui/non-fmt-panic.stderr

@@ -4,7 +4,7 @@ warning: panic message contains a brace
 LL |     panic!("here's a brace: {");
    |                             ^
    |
-   = note: `#[warn(non_fmt_panic)]` on by default
+   = note: `#[warn(non_fmt_panics)]` on by default
    = note: this message is not used as a format string, but will be in Rust 2021
 help: add a "{}" format string to use the message literally
    |

src/test/ui/panics/explicit-panic-msg.rs

@@ -1,6 +1,6 @@
 #![allow(unused_assignments)]
 #![allow(unused_variables)]
-#![allow(non_fmt_panic)]
+#![allow(non_fmt_panics)]
 
 // run-fail
 // error-pattern:wooooo

src/test/ui/panics/panic-macro-any-wrapped.rs

@@ -2,7 +2,7 @@
 // error-pattern:panicked at 'Box<dyn Any>'
 // ignore-emscripten no processes
 
-#![allow(non_fmt_panic)]
+#![allow(non_fmt_panics)]
 
 fn main() {
     panic!(Box::new(612_i64));

src/test/ui/panics/panic-macro-any.rs

@@ -3,7 +3,7 @@
 // ignore-emscripten no processes
 
 #![feature(box_syntax)]
-#![allow(non_fmt_panic)]
+#![allow(non_fmt_panics)]
 
 fn main() {
     panic!(box 413 as Box<dyn std::any::Any + Send>);

src/test/ui/rust-2021/future-prelude-collision-imported.fixed

@@ -1,7 +1,7 @@
 // run-rustfix
 // edition:2018
 // check-pass
-#![warn(future_prelude_collision)]
+#![warn(rust_2021_prelude_collisions)]
 #![allow(dead_code)]
 #![allow(unused_imports)]
 

src/test/ui/rust-2021/future-prelude-collision-imported.rs

@@ -1,7 +1,7 @@
 // run-rustfix
 // edition:2018
 // check-pass
-#![warn(future_prelude_collision)]
+#![warn(rust_2021_prelude_collisions)]
 #![allow(dead_code)]
 #![allow(unused_imports)]
 

src/test/ui/rust-2021/future-prelude-collision-imported.stderr

@@ -7,8 +7,8 @@ LL |         let _: u32 = 3u8.try_into().unwrap();
 note: the lint level is defined here
   --> $DIR/future-prelude-collision-imported.rs:4:9
    |
-LL | #![warn(future_prelude_collision)]
+LL | #![warn(rust_2021_prelude_collisions)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
    = note: for more information, see issue #85684 <https://github.com/rust-lang/rust/issues/85684>
 

src/test/ui/rust-2021/future-prelude-collision-shadow.rs

@@ -1,5 +1,5 @@
 // edition:2018
-#![warn(future_prelude_collision)]
+#![warn(rust_2021_prelude_collisions)]
 #![allow(dead_code)]
 #![allow(unused_imports)]
 

src/test/ui/rust-2021/future-prelude-collision-unneeded.rs

@@ -1,12 +1,14 @@
 // edition:2018
 // check-pass
 #![allow(unused)]
-#![deny(future_prelude_collision)]
+#![deny(rust_2021_prelude_collisions)]
 
 struct S;
 
 impl S {
-    fn try_into(self) -> S { S }
+    fn try_into(self) -> S {
+        S
+    }
 }
 
 // See https://github.com/rust-lang/rust/issues/86633

src/test/ui/rust-2021/future-prelude-collision.fixed

@@ -1,7 +1,7 @@
 // run-rustfix
 // edition:2018
 // check-pass
-#![warn(future_prelude_collision)]
+#![warn(rust_2021_prelude_collisions)]
 
 trait TryIntoU32 {
     fn try_into(self) -> Result<u32, ()>;

src/test/ui/rust-2021/future-prelude-collision.rs

@@ -1,7 +1,7 @@
 // run-rustfix
 // edition:2018
 // check-pass
-#![warn(future_prelude_collision)]
+#![warn(rust_2021_prelude_collisions)]
 
 trait TryIntoU32 {
     fn try_into(self) -> Result<u32, ()>;

src/test/ui/rust-2021/future-prelude-collision.stderr

@@ -7,8 +7,8 @@ LL |     let _: u32 = 3u8.try_into().unwrap();
 note: the lint level is defined here
   --> $DIR/future-prelude-collision.rs:4:9
    |
-LL | #![warn(future_prelude_collision)]
+LL | #![warn(rust_2021_prelude_collisions)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
    = note: for more information, see issue #85684 <https://github.com/rust-lang/rust/issues/85684>
 

src/test/ui/rust-2021/generic-type-collision.fixed

@@ -1,7 +1,7 @@
 // check-pass
 // run-rustfix
 // edition 2018
-#![warn(future_prelude_collision)]
+#![warn(rust_2021_prelude_collisions)]
 
 trait MyTrait<A> {
     fn from_iter(x: Option<A>);

src/test/ui/rust-2021/generic-type-collision.rs

@@ -1,7 +1,7 @@
 // check-pass
 // run-rustfix
 // edition 2018
-#![warn(future_prelude_collision)]
+#![warn(rust_2021_prelude_collisions)]
 
 trait MyTrait<A> {
     fn from_iter(x: Option<A>);

src/test/ui/rust-2021/generic-type-collision.stderr

@@ -7,8 +7,8 @@ LL |     <Vec<i32>>::from_iter(None);
 note: the lint level is defined here
   --> $DIR/generic-type-collision.rs:4:9
    |
-LL | #![warn(future_prelude_collision)]
+LL | #![warn(rust_2021_prelude_collisions)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
    = note: for more information, see issue #85684 <https://github.com/rust-lang/rust/issues/85684>
 

src/test/ui/rust-2021/inherent-dyn-collision.fixed

@@ -5,7 +5,7 @@
 // run-rustfix
 // edition:2018
 
-#![warn(future_prelude_collision)]
+#![warn(rust_2021_prelude_collisions)]
 
 trait TryIntoU32 {
     fn try_into(&self) -> Result<u32, ()>;

src/test/ui/rust-2021/inherent-dyn-collision.rs

@@ -5,7 +5,7 @@
 // run-rustfix
 // edition:2018
 
-#![warn(future_prelude_collision)]
+#![warn(rust_2021_prelude_collisions)]
 
 trait TryIntoU32 {
     fn try_into(&self) -> Result<u32, ()>;

src/test/ui/rust-2021/inherent-dyn-collision.stderr

@@ -7,8 +7,8 @@ LL |         get_dyn_trait().try_into().unwrap()
 note: the lint level is defined here
   --> $DIR/inherent-dyn-collision.rs:8:9
    |
-LL | #![warn(future_prelude_collision)]
+LL | #![warn(rust_2021_prelude_collisions)]
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
    = note: for more information, see issue #85684 <https://github.com/rust-lang/rust/issues/85684>
 

src/test/ui/rust-2021/inherent-method-collision.rs

@@ -2,7 +2,7 @@
 //
 // check-pass
 
-#![deny(future_prelude_collision)]
+#![deny(rust_2021_prelude_collisions)]
 
 pub struct MySeq {}
 

src/test/ui/rust-2021/reserved-prefixes-migration.fixed

@@ -2,7 +2,7 @@
 // run-rustfix
 // compile-flags: -Z unstable-options --edition 2018
 
-#![warn(reserved_prefix)]
+#![warn(rust_2021_prefixes_incompatible_syntax)]
 
 macro_rules! m2 {
     ($a:tt $b:tt) => {};
@@ -14,16 +14,16 @@ macro_rules! m3 {
 
 fn main() {
     m2!(z "hey");
-    //~^ WARNING prefix `z` is unknown [reserved_prefix]
+    //~^ WARNING prefix `z` is unknown [rust_2021_prefixes_incompatible_syntax]
     //~| WARNING hard error in Rust 2021
     m2!(prefix "hey");
-    //~^ WARNING prefix `prefix` is unknown [reserved_prefix]
+    //~^ WARNING prefix `prefix` is unknown [rust_2021_prefixes_incompatible_syntax]
     //~| WARNING hard error in Rust 2021
     m3!(hey #123);
-    //~^ WARNING prefix `hey` is unknown [reserved_prefix]
+    //~^ WARNING prefix `hey` is unknown [rust_2021_prefixes_incompatible_syntax]
     //~| WARNING hard error in Rust 2021
     m3!(hey #hey);
-    //~^ WARNING prefix `hey` is unknown [reserved_prefix]
+    //~^ WARNING prefix `hey` is unknown [rust_2021_prefixes_incompatible_syntax]
     //~| WARNING hard error in Rust 2021
 }
 
@@ -33,6 +33,6 @@ macro_rules! quote {
 
 quote! {
     #name = #kind #value
-    //~^ WARNING prefix `kind` is unknown [reserved_prefix]
+    //~^ WARNING prefix `kind` is unknown [rust_2021_prefixes_incompatible_syntax]
     //~| WARNING hard error in Rust 2021
 }

src/test/ui/rust-2021/reserved-prefixes-migration.rs

@@ -2,7 +2,7 @@
 // run-rustfix
 // compile-flags: -Z unstable-options --edition 2018
 
-#![warn(reserved_prefix)]
+#![warn(rust_2021_prefixes_incompatible_syntax)]
 
 macro_rules! m2 {
     ($a:tt $b:tt) => {};
@@ -14,16 +14,16 @@ macro_rules! m3 {
 
 fn main() {
     m2!(z"hey");
-    //~^ WARNING prefix `z` is unknown [reserved_prefix]
+    //~^ WARNING prefix `z` is unknown [rust_2021_prefixes_incompatible_syntax]
     //~| WARNING hard error in Rust 2021
     m2!(prefix"hey");
-    //~^ WARNING prefix `prefix` is unknown [reserved_prefix]
+    //~^ WARNING prefix `prefix` is unknown [rust_2021_prefixes_incompatible_syntax]
     //~| WARNING hard error in Rust 2021
     m3!(hey#123);
-    //~^ WARNING prefix `hey` is unknown [reserved_prefix]
+    //~^ WARNING prefix `hey` is unknown [rust_2021_prefixes_incompatible_syntax]
     //~| WARNING hard error in Rust 2021
     m3!(hey#hey);
-    //~^ WARNING prefix `hey` is unknown [reserved_prefix]
+    //~^ WARNING prefix `hey` is unknown [rust_2021_prefixes_incompatible_syntax]
     //~| WARNING hard error in Rust 2021
 }
 
@@ -33,6 +33,6 @@ macro_rules! quote {
 
 quote! {
     #name = #kind#value
-    //~^ WARNING prefix `kind` is unknown [reserved_prefix]
+    //~^ WARNING prefix `kind` is unknown [rust_2021_prefixes_incompatible_syntax]
     //~| WARNING hard error in Rust 2021
 }

src/test/ui/rust-2021/reserved-prefixes-migration.stderr

@@ -7,8 +7,8 @@ LL |     m2!(z"hey");
 note: the lint level is defined here
   --> $DIR/reserved-prefixes-migration.rs:5:9
    |
-LL | #![warn(reserved_prefix)]
+LL | #![warn(rust_2021_prefixes_incompatible_syntax)]
-   |         ^^^^^^^^^^^^^^^
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
    = note: for more information, see issue #84978 <https://github.com/rust-lang/rust/issues/84978>
 help: insert whitespace here to avoid this being parsed as a prefix in Rust 2021

src/tools/clippy/CHANGELOG.md

@@ -592,7 +592,7 @@ Released 2021-02-11
 
 * Previously deprecated [`str_to_string`] and [`string_to_string`] have been un-deprecated
   as `restriction` lints [#6333](https://github.com/rust-lang/rust-clippy/pull/6333)
-* Deprecate `panic_params` lint. This is now available in rustc as `non_fmt_panic`
+* Deprecate `panic_params` lint. This is now available in rustc as `non_fmt_panics`
   [#6351](https://github.com/rust-lang/rust-clippy/pull/6351)
 * Move [`map_err_ignore`] to `restriction`
   [#6416](https://github.com/rust-lang/rust-clippy/pull/6416)

src/tools/clippy/clippy_lints/src/lib.rs

@@ -2171,7 +2171,7 @@ pub fn register_renamed(ls: &mut rustc_lint::LintStore) {
     ls.register_renamed("clippy::unused_label", "unused_labels");
     ls.register_renamed("clippy::drop_bounds", "drop_bounds");
     ls.register_renamed("clippy::temporary_cstring_as_ptr", "temporary_cstring_as_ptr");
-    ls.register_renamed("clippy::panic_params", "non_fmt_panic");
+    ls.register_renamed("clippy::panic_params", "non_fmt_panics");
     ls.register_renamed("clippy::unknown_clippy_lints", "unknown_lints");
 }
 

src/tools/clippy/tests/ui/assertions_on_constants.rs

@@ -1,4 +1,4 @@
-#![allow(non_fmt_panic)]
+#![allow(non_fmt_panics)]
 
 macro_rules! assert_const {
     ($len:expr) => {

src/tools/clippy/tests/ui/deprecated.stderr

@@ -60,11 +60,11 @@ error: lint `clippy::temporary_cstring_as_ptr` has been renamed to `temporary_cs
 LL | #[warn(clippy::temporary_cstring_as_ptr)]
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the new name: `temporary_cstring_as_ptr`
 
-error: lint `clippy::panic_params` has been renamed to `non_fmt_panic`
+error: lint `clippy::panic_params` has been renamed to `non_fmt_panics`
   --> $DIR/deprecated.rs:11:8
    |
 LL | #[warn(clippy::panic_params)]
-   |        ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `non_fmt_panic`
+   |        ^^^^^^^^^^^^^^^^^^^^ help: use the new name: `non_fmt_panics`
 
 error: lint `clippy::unknown_clippy_lints` has been renamed to `unknown_lints`
   --> $DIR/deprecated.rs:12:8

src/tools/lint-docs/src/lib.rs

@@ -467,7 +467,9 @@ fn lint_name(line: &str) -> Result<String, &'static str> {
                 return Err("lint name should end with comma");
             }
             let name = &name[..name.len() - 1];
-            if !name.chars().all(|ch| ch.is_uppercase() || ch == '_') || name.is_empty() {
+            if !name.chars().all(|ch| ch.is_uppercase() || ch.is_ascii_digit() || ch == '_')
+                || name.is_empty()
+            {
                 return Err("lint name did not have expected format");
             }
             Ok(name.to_lowercase().to_string())