Rollup of 10 pull requests

compiler/rustc_ast_lowering/src/item.rs

@@ -26,44 +26,43 @@ pub(super) struct ItemLowerer<'a, 'lowering, 'hir> {
 }
 
 impl ItemLowerer<'_, '_, '_> {
-    fn with_trait_impl_ref(&mut self, impl_ref: &Option<TraitRef>, f: impl FnOnce(&mut Self)) {
+    fn with_trait_impl_ref<T>(
+        &mut self,
+        impl_ref: &Option<TraitRef>,
+        f: impl FnOnce(&mut Self) -> T,
+    ) -> T {
         let old = self.lctx.is_in_trait_impl;
         self.lctx.is_in_trait_impl = impl_ref.is_some();
-        f(self);
+        let ret = f(self);
         self.lctx.is_in_trait_impl = old;
+        ret
     }
 }
 
 impl<'a> Visitor<'a> for ItemLowerer<'a, '_, '_> {
     fn visit_item(&mut self, item: &'a Item) {
-        let mut item_hir_id = None;
-        self.lctx.with_hir_id_owner(item.id, |lctx| {
+        let hir_id = self.lctx.with_hir_id_owner(item.id, |lctx| {
             lctx.without_in_scope_lifetime_defs(|lctx| {
-                if let Some(hir_item) = lctx.lower_item(item) {
-                    let id = lctx.insert_item(hir_item);
-                    item_hir_id = Some(id);
-                }
+                let hir_item = lctx.lower_item(item);
+                lctx.insert_item(hir_item)
             })
         });
 
-        if let Some(hir_id) = item_hir_id {
-            self.lctx.with_parent_item_lifetime_defs(hir_id, |this| {
-                let this = &mut ItemLowerer { lctx: this };
-                match item.kind {
-                    ItemKind::Mod(..) => {
-                        let def_id = this.lctx.lower_node_id(item.id).expect_owner();
-                        let old_current_module =
-                            mem::replace(&mut this.lctx.current_module, def_id);
-                        visit::walk_item(this, item);
-                        this.lctx.current_module = old_current_module;
-                    }
-                    ItemKind::Impl(box ImplKind { ref of_trait, .. }) => {
-                        this.with_trait_impl_ref(of_trait, |this| visit::walk_item(this, item));
-                    }
-                    _ => visit::walk_item(this, item),
+        self.lctx.with_parent_item_lifetime_defs(hir_id, |this| {
+            let this = &mut ItemLowerer { lctx: this };
+            match item.kind {
+                ItemKind::Mod(..) => {
+                    let def_id = this.lctx.lower_node_id(item.id).expect_owner();
+                    let old_current_module = mem::replace(&mut this.lctx.current_module, def_id);
+                    visit::walk_item(this, item);
+                    this.lctx.current_module = old_current_module;
                 }
-            });
-        }
+                ItemKind::Impl(box ImplKind { ref of_trait, .. }) => {
+                    this.with_trait_impl_ref(of_trait, |this| visit::walk_item(this, item));
+                }
+                _ => visit::walk_item(this, item),
+            }
+        });
     }
 
     fn visit_fn(&mut self, fk: FnKind<'a>, sp: Span, _: NodeId) {
@@ -113,7 +112,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     fn with_parent_item_lifetime_defs<T>(
         &mut self,
         parent_hir_id: hir::ItemId,
-        f: impl FnOnce(&mut LoweringContext<'_, '_>) -> T,
+        f: impl FnOnce(&mut Self) -> T,
     ) -> T {
         let old_len = self.in_scope_lifetimes.len();
 
@@ -137,10 +136,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     // Clears (and restores) the `in_scope_lifetimes` field. Used when
     // visiting nested items, which never inherit in-scope lifetimes
     // from their surrounding environment.
-    fn without_in_scope_lifetime_defs<T>(
-        &mut self,
-        f: impl FnOnce(&mut LoweringContext<'_, '_>) -> T,
-    ) -> T {
+    fn without_in_scope_lifetime_defs<T>(&mut self, f: impl FnOnce(&mut Self) -> T) -> T {
         let old_in_scope_lifetimes = mem::replace(&mut self.in_scope_lifetimes, vec![]);
 
         // this vector is only used when walking over impl headers,
@@ -208,19 +204,19 @@ impl<'hir> LoweringContext<'_, 'hir> {
         }
     }
 
-    pub fn lower_item(&mut self, i: &Item) -> Option<hir::Item<'hir>> {
+    pub fn lower_item(&mut self, i: &Item) -> hir::Item<'hir> {
         let mut ident = i.ident;
         let mut vis = self.lower_visibility(&i.vis, None);
         let hir_id = self.lower_node_id(i.id);
         let attrs = self.lower_attrs(hir_id, &i.attrs);
         let kind = self.lower_item_kind(i.span, i.id, hir_id, &mut ident, attrs, &mut vis, &i.kind);
-        Some(hir::Item {
+        hir::Item {
             def_id: hir_id.expect_owner(),
             ident: self.lower_ident(ident),
             kind,
             vis,
             span: self.lower_span(i.span),
-        })
+        }
     }
 
     fn lower_item_kind(

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -1442,7 +1442,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                 if !self.is_tilde_const_allowed {
                     self.err_handler()
                         .struct_span_err(bound.span(), "`~const` is not allowed here")
-                        .note("only allowed on bounds on traits' associated types, const fns, const impls and its associated functions")
+                        .note("only allowed on bounds on traits' associated types and functions, const fns, const impls and its associated functions")
                         .emit();
                 }
             }
@@ -1616,7 +1616,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                 walk_list!(self, visit_ty, ty);
             }
             AssocItemKind::Fn(box FnKind(_, ref sig, ref generics, ref body))
-                if self.in_const_trait_impl =>
+                if self.in_const_trait_impl || ctxt == AssocCtxt::Trait =>
             {
                 self.visit_vis(&item.vis);
                 self.visit_ident(item.ident);

compiler/rustc_middle/src/mir/mod.rs

@@ -426,6 +426,11 @@ impl<'tcx> Body<'tcx> {
         (arg_count + 1..local_count).map(Local::new)
     }
 
+    #[inline]
+    pub fn drain_vars_and_temps<'a>(&'a mut self) -> impl Iterator<Item = LocalDecl<'tcx>> + 'a {
+        self.local_decls.drain(self.arg_count + 1..)
+    }
+
     /// Changes a statement to a nop. This is both faster than deleting instructions and avoids
     /// invalidating statement indices in `Location`s.
     pub fn make_statement_nop(&mut self, location: Location) {

compiler/rustc_mir/src/transform/inline.rs

@@ -607,13 +607,7 @@ impl Inliner<'tcx> {
                 }
 
                 // Insert all of the (mapped) parts of the callee body into the caller.
-                caller_body.local_decls.extend(
-                    // FIXME(eddyb) make `Range<Local>` iterable so that we can use
-                    // `callee_body.local_decls.drain(callee_body.vars_and_temps())`
-                    callee_body
-                        .vars_and_temps_iter()
-                        .map(|local| callee_body.local_decls[local].clone()),
-                );
+                caller_body.local_decls.extend(callee_body.drain_vars_and_temps());
                 caller_body.source_scopes.extend(&mut callee_body.source_scopes.drain(..));
                 caller_body.var_debug_info.append(&mut callee_body.var_debug_info);
                 caller_body.basic_blocks_mut().extend(callee_body.basic_blocks_mut().drain(..));

compiler/rustc_span/src/lib.rs

@@ -597,6 +597,14 @@ impl Span {
         if !expn_data.is_root() { Some(expn_data.call_site) } else { None }
     }
 
+    /// Walk down the expansion ancestors to find a span that's contained within `outer`.
+    pub fn find_ancestor_inside(mut self, outer: Span) -> Option<Span> {
+        while !outer.contains(self) {
+            self = self.parent()?;
+        }
+        Some(self)
+    }
+
     /// Edition of the crate from which this span came.
     pub fn edition(self) -> edition::Edition {
         self.ctxt().edition()

compiler/rustc_target/src/spec/mod.rs

@@ -1501,7 +1501,8 @@ impl Target {
             | Cdecl
             | EfiApi => true,
             X86Interrupt => ["x86", "x86_64"].contains(&&self.arch[..]),
-            Aapcs | CCmseNonSecureCall => ["arm", "aarch64"].contains(&&self.arch[..]),
+            Aapcs => "arm" == self.arch,
+            CCmseNonSecureCall => ["arm", "aarch64"].contains(&&self.arch[..]),
             Win64 | SysV64 => self.arch == "x86_64",
             PtxKernel => self.arch == "nvptx64",
             Msp430Interrupt => self.arch == "msp430",

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

@@ -156,15 +156,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         segment.ident.name
                     ));
 
-                    let (self_adjusted, precise) = self.adjust_expr(pick, self_expr);
+                    let (self_adjusted, precise) = self.adjust_expr(pick, self_expr, sp);
                     if precise {
                         let args = args
                             .iter()
                             .skip(1)
                             .map(|arg| {
+                                let span = arg.span.find_ancestor_inside(sp).unwrap_or_default();
                                 format!(
                                     ", {}",
-                                    self.sess().source_map().span_to_snippet(arg.span).unwrap()
+                                    self.sess().source_map().span_to_snippet(span).unwrap()
                                 )
                             })
                             .collect::<String>();
@@ -173,8 +174,22 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             sp,
                             "disambiguate the associated function",
                             format!(
-                                "{}::{}({}{})",
-                                trait_name, segment.ident.name, self_adjusted, args
+                                "{}::{}{}({}{})",
+                                trait_name,
+                                segment.ident.name,
+                                if let Some(args) = segment.args.as_ref().and_then(|args| self
+                                    .sess()
+                                    .source_map()
+                                    .span_to_snippet(args.span_ext)
+                                    .ok())
+                                {
+                                    // Keep turbofish.
+                                    format!("::{}", args)
+                                } else {
+                                    String::new()
+                                },
+                                self_adjusted,
+                                args,
                             ),
                             Applicability::MachineApplicable,
                         );
@@ -272,11 +287,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 method_name.name
             ));
 
-            let mut self_ty_name = self
-                .sess()
-                .source_map()
-                .span_to_snippet(self_ty_span)
-                .unwrap_or_else(|_| self_ty.to_string());
+            let mut self_ty_name = self_ty_span
+                .find_ancestor_inside(span)
+                .and_then(|span| self.sess().source_map().span_to_snippet(span).ok())
+                .unwrap_or_else(|| self_ty.to_string());
 
             // Get the number of generics the self type has (if an Adt) unless we can determine that
             // the user has written the self type with generics already which we (naively) do by looking
@@ -370,7 +384,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     /// Creates a string version of the `expr` that includes explicit adjustments.
     /// Returns the string and also a bool indicating whther this is a *precise*
     /// suggestion.
-    fn adjust_expr(&self, pick: &Pick<'tcx>, expr: &hir::Expr<'tcx>) -> (String, bool) {
+    fn adjust_expr(
+        &self,
+        pick: &Pick<'tcx>,
+        expr: &hir::Expr<'tcx>,
+        outer: Span,
+    ) -> (String, bool) {
         let derefs = "*".repeat(pick.autoderefs);
 
         let autoref = match pick.autoref_or_ptr_adjustment {
@@ -379,12 +398,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             Some(probe::AutorefOrPtrAdjustment::ToConstPtr) | None => "",
         };
 
-        let (expr_text, precise) =
-            if let Ok(expr_text) = self.sess().source_map().span_to_snippet(expr.span) {
-                (expr_text, true)
-            } else {
-                ("(..)".to_string(), false)
-            };
+        let (expr_text, precise) = if let Some(expr_text) = expr
+            .span
+            .find_ancestor_inside(outer)
+            .and_then(|span| self.sess().source_map().span_to_snippet(span).ok())
+        {
+            (expr_text, true)
+        } else {
+            ("(..)".to_string(), false)
+        };
 
         let adjusted_text = if let Some(probe::AutorefOrPtrAdjustment::ToConstPtr) =
             pick.autoref_or_ptr_adjustment

compiler/rustc_typeck/src/check/upvar.rs

@@ -680,15 +680,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         migrated_variables_concat
                     );
 
-                    let mut closure_body_span = self.tcx.hir().span(body_id.hir_id);
-
                     // If the body was entirely expanded from a macro
                     // invocation, i.e. the body is not contained inside the
                     // closure span, then we walk up the expansion until we
                     // find the span before the expansion.
-                    while !closure_body_span.is_dummy() && !closure_span.contains(closure_body_span) {
-                        closure_body_span = closure_body_span.parent().unwrap_or(DUMMY_SP);
-                    }
+                    let closure_body_span = self.tcx.hir().span(body_id.hir_id)
+                        .find_ancestor_inside(closure_span)
+                        .unwrap_or(DUMMY_SP);
 
                     if let Ok(s) = self.tcx.sess.source_map().span_to_snippet(closure_body_span) {
                         let mut lines = s.lines();

library/core/src/lib.rs

@@ -76,6 +76,7 @@
 #![feature(const_alloc_layout)]
 #![feature(const_arguments_as_str)]
 #![feature(const_assert_type)]
+#![feature(const_bigint_helper_methods)]
 #![feature(const_caller_location)]
 #![feature(const_cell_into_inner)]
 #![feature(const_discriminant)]

library/core/src/num/int_macros.rs

@@ -1341,6 +1341,33 @@ macro_rules! int_impl {
             (a as Self, b)
         }
 
+        /// Calculates `self + rhs + carry` without the ability to overflow.
+        ///
+        /// Performs "ternary addition" which takes in an extra bit to add, and may return an
+        /// additional bit of overflow. This allows for chaining together multiple additions
+        /// to create "big integers" which represent larger values.
+        ///
+        /// # Examples
+        ///
+        /// Basic usage
+        ///
+        /// ```
+        /// #![feature(bigint_helper_methods)]
+        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".carrying_add(2, false), (7, false));")]
+        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".carrying_add(2, true), (8, false));")]
+        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, false), (", stringify!($SelfT), "::MIN, false));")]
+        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MAX.carrying_add(1, true), (", stringify!($SelfT), "::MIN + 1, false));")]
+        /// ```
+        #[unstable(feature = "bigint_helper_methods", issue = "85532")]
+        #[rustc_const_unstable(feature = "const_bigint_helper_methods", issue = "85532")]
+        #[must_use = "this returns the result of the operation, \
+                      without modifying the original"]
+        #[inline]
+        pub const fn carrying_add(self, rhs: Self, carry: bool) -> (Self, bool) {
+            let (sum, carry) = (self as $UnsignedT).carrying_add(rhs as $UnsignedT, carry);
+            (sum as $SelfT, carry)
+        }
+
         /// Calculates `self` - `rhs`
         ///
         /// Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic overflow
@@ -1365,6 +1392,33 @@ macro_rules! int_impl {
             (a as Self, b)
         }
 
+        /// Calculates `self - rhs - borrow` without the ability to overflow.
+        ///
+        /// Performs "ternary subtraction" which takes in an extra bit to subtract, and may return
+        /// an additional bit of overflow. This allows for chaining together multiple subtractions
+        /// to create "big integers" which represent larger values.
+        ///
+        /// # Examples
+        ///
+        /// Basic usage
+        ///
+        /// ```
+        /// #![feature(bigint_helper_methods)]
+        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".borrowing_sub(2, false), (3, false));")]
+        #[doc = concat!("assert_eq!(5", stringify!($SelfT), ".borrowing_sub(2, true), (2, false));")]
+        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.borrowing_sub(1, false), (", stringify!($SelfT), "::MAX, false));")]
+        #[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN.borrowing_sub(1, true), (", stringify!($SelfT), "::MAX - 1, false));")]
+        /// ```
+        #[unstable(feature = "bigint_helper_methods", issue = "85532")]
+        #[rustc_const_unstable(feature = "const_bigint_helper_methods", issue = "85532")]
+        #[must_use = "this returns the result of the operation, \
+                      without modifying the original"]
+        #[inline]
+        pub const fn borrowing_sub(self, rhs: Self, borrow: bool) -> (Self, bool) {
+            let (sum, borrow) = (self as $UnsignedT).borrowing_sub(rhs as $UnsignedT, borrow);
+            (sum as $SelfT, borrow)
+        }
+
         /// Calculates the multiplication of `self` and `rhs`.
         ///
         /// Returns a tuple of the multiplication along with a boolean indicating whether an arithmetic overflow