Rollup of 9 pull requests

Cargo.lock

@@ -1821,9 +1821,9 @@ checksum = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
 
 [[package]]
 name = "libc"
-version = "0.2.64"
+version = "0.2.66"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "74dfca3d9957906e8d1e6a0b641dc9a59848e793f1da2165889fd4f62d10d79c"
+checksum = "d515b1f41455adea1313a4a2ac8a8a477634fbae63cc6100e3aebb207ce61558"
 dependencies = [
  "rustc-std-workspace-core",
 ]

src/libcore/cmp.rs

@@ -534,7 +534,6 @@ impl<T: Ord> Ord for Reverse<T> {
 ///     }
 /// }
 /// ```
-#[lang = "ord"]
 #[doc(alias = "<")]
 #[doc(alias = ">")]
 #[doc(alias = "<=")]

src/libcore/ops/try.rs

@@ -5,19 +5,20 @@
 /// extracting those success or failure values from an existing instance and
 /// creating a new instance from a success or failure value.
 #[unstable(feature = "try_trait", issue = "42327")]
-#[rustc_on_unimplemented(
+#[cfg_attr(not(bootstrap), rustc_on_unimplemented(
 on(all(
 any(from_method="from_error", from_method="from_ok"),
 from_desugaring="QuestionMark"),
 message="the `?` operator can only be used in {ItemContext} \
                that returns `Result` or `Option` \
                (or another type that implements `{Try}`)",
-label="cannot use the `?` operator in {ItemContext} that returns `{Self}`"),
+label="cannot use the `?` operator in {ItemContext} that returns `{Self}`",
+enclosing_scope="this function should return `Result` or `Option` to accept `?`"),
 on(all(from_method="into_result", from_desugaring="QuestionMark"),
 message="the `?` operator can only be applied to values \
                that implement `{Try}`",
 label="the `?` operator cannot be applied to type `{Self}`")
-)]
+))]
 #[doc(alias = "?")]
 pub trait Try {
     /// The type of this value when viewed as successful.

src/libpanic_unwind/gcc.rs

@@ -129,6 +129,9 @@ const UNWIND_DATA_REG: (i32, i32) = (24, 25); // I0, I1
 #[cfg(target_arch = "hexagon")]
 const UNWIND_DATA_REG: (i32, i32) = (0, 1); // R0, R1
 
+#[cfg(target_arch = "riscv64")]
+const UNWIND_DATA_REG: (i32, i32) = (10, 11); // x10, x11
+
 // The following code is based on GCC's C and C++ personality routines.  For reference, see:
 // https://github.com/gcc-mirror/gcc/blob/master/libstdc++-v3/libsupc++/eh_personality.cc
 // https://github.com/gcc-mirror/gcc/blob/trunk/libgcc/unwind-c.c

src/librustc/hir/lowering.rs

@@ -1003,7 +1003,7 @@ impl<'a> LoweringContext<'a> {
             AttrKind::Normal(ref item) => {
                 AttrKind::Normal(AttrItem {
                     path: item.path.clone(),
-                    tokens: self.lower_token_stream(item.tokens.clone()),
+                    args: self.lower_mac_args(&item.args),
                 })
             }
             AttrKind::DocComment(comment) => AttrKind::DocComment(comment)
@@ -1017,6 +1017,16 @@ impl<'a> LoweringContext<'a> {
         }
     }
 
+    fn lower_mac_args(&mut self, args: &MacArgs) -> MacArgs {
+        match *args {
+            MacArgs::Empty => MacArgs::Empty,
+            MacArgs::Delimited(dspan, delim, ref tokens) =>
+                MacArgs::Delimited(dspan, delim, self.lower_token_stream(tokens.clone())),
+            MacArgs::Eq(eq_span, ref tokens) =>
+                MacArgs::Eq(eq_span, self.lower_token_stream(tokens.clone())),
+        }
+    }
+
     fn lower_token_stream(&mut self, tokens: TokenStream) -> TokenStream {
         tokens
             .into_trees()

src/librustc/hir/lowering/item.rs

@@ -233,7 +233,7 @@ impl LoweringContext<'_> {
 
         if let ItemKind::MacroDef(ref def) = i.kind {
             if !def.legacy || attr::contains_name(&i.attrs, sym::macro_export) {
-                let body = self.lower_token_stream(def.stream());
+                let body = self.lower_token_stream(def.body.inner_tokens());
                 let hir_id = self.lower_node_id(i.id);
                 self.exported_macros.push(hir::MacroDef {
                     name: ident.name,

src/librustc/middle/lang_items.rs

@@ -358,7 +358,6 @@ language_item_table! {
     // Don't be fooled by the naming here: this lang item denotes `PartialEq`, not `Eq`.
     EqTraitLangItem,             "eq",                 eq_trait,                Target::Trait;
     PartialOrdTraitLangItem,     "partial_ord",        partial_ord_trait,       Target::Trait;
-    OrdTraitLangItem,            "ord",                ord_trait,               Target::Trait;
 
     // A number of panic-related lang items. The `panic` item corresponds to
     // divide-by-zero and various panic cases with `match`. The

src/librustc/mir/interpret/error.rs

@@ -370,6 +370,14 @@ pub enum UndefinedBehaviorInfo {
     Unreachable,
     /// An enum discriminant was set to a value which was outside the range of valid values.
     InvalidDiscriminant(ScalarMaybeUndef),
+    /// A slice/array index projection went out-of-bounds.
+    BoundsCheckFailed { len: u64, index: u64 },
+    /// Something was divided by 0 (x / 0).
+    DivisionByZero,
+    /// Something was "remainded" by 0 (x % 0).
+    RemainderByZero,
+    /// Overflowing inbounds pointer arithmetic.
+    PointerArithOverflow,
 }
 
 impl fmt::Debug for UndefinedBehaviorInfo {
@@ -379,9 +387,18 @@ impl fmt::Debug for UndefinedBehaviorInfo {
             Ub(msg) | UbExperimental(msg) =>
                 write!(f, "{}", msg),
             Unreachable =>
-                write!(f, "entered unreachable code"),
+                write!(f, "entering unreachable code"),
             InvalidDiscriminant(val) =>
-                write!(f, "encountered invalid enum discriminant {}", val),
+                write!(f, "encountering invalid enum discriminant {}", val),
+            BoundsCheckFailed { ref len, ref index } =>
+                write!(f, "indexing out of bounds: the len is {:?} but the index is {:?}",
+                    len, index),
+            DivisionByZero =>
+                write!(f, "dividing by zero"),
+            RemainderByZero =>
+                write!(f, "calculating the remainder with a divisor of zero"),
+            PointerArithOverflow =>
+                write!(f, "overflowing in-bounds pointer arithmetic"),
         }
     }
 }

src/librustc/mir/interpret/pointer.rs

@@ -1,6 +1,5 @@
 use super::{AllocId, InterpResult};
 
-use crate::mir;
 use crate::ty::layout::{self, HasDataLayout, Size};
 
 use rustc_macros::HashStable;
@@ -88,13 +87,13 @@ pub trait PointerArithmetic: layout::HasDataLayout {
     #[inline]
     fn offset<'tcx>(&self, val: u64, i: u64) -> InterpResult<'tcx, u64> {
         let (res, over) = self.overflowing_offset(val, i);
-        if over { throw_panic!(Overflow(mir::BinOp::Add)) } else { Ok(res) }
+        if over { throw_ub!(PointerArithOverflow) } else { Ok(res) }
     }
 
     #[inline]
     fn signed_offset<'tcx>(&self, val: u64, i: i64) -> InterpResult<'tcx, u64> {
         let (res, over) = self.overflowing_signed_offset(val, i128::from(i));
-        if over { throw_panic!(Overflow(mir::BinOp::Add)) } else { Ok(res) }
+        if over { throw_ub!(PointerArithOverflow) } else { Ok(res) }
     }
 }
 

src/librustc/traits/error_reporting.rs

@@ -521,7 +521,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         ) {
             command.evaluate(self.tcx, trait_ref, &flags[..])
         } else {
-            OnUnimplementedNote::empty()
+            OnUnimplementedNote::default()
         }
     }
 
@@ -697,6 +697,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         fallback_has_occurred: bool,
         points_at_arg: bool,
     ) {
+        let tcx = self.tcx;
         let span = obligation.cause.span;
 
         let mut err = match *error {
@@ -732,6 +733,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                             message,
                             label,
                             note,
+                            enclosing_scope,
                         } = self.on_unimplemented_note(trait_ref, obligation);
                         let have_alt_message = message.is_some() || label.is_some();
                         let is_try = self.tcx.sess.source_map().span_to_snippet(span)
@@ -798,6 +800,19 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                             // If it has a custom `#[rustc_on_unimplemented]` note, let's display it
                             err.note(s.as_str());
                         }
+                        if let Some(ref s) = enclosing_scope {
+                            let enclosing_scope_span = tcx.def_span(
+                                tcx.hir()
+                                    .opt_local_def_id(obligation.cause.body_id)
+                                    .unwrap_or_else(|| {
+                                        tcx.hir().body_owner_def_id(hir::BodyId {
+                                            hir_id: obligation.cause.body_id,
+                                        })
+                                    }),
+                            );
+
+                            err.span_label(enclosing_scope_span, s.as_str());
+                        }
 
                         self.suggest_borrow_on_unsized_slice(&obligation.cause.code, &mut err);
                         self.suggest_fn_call(&obligation, &mut err, &trait_ref, points_at_arg);

src/librustc/traits/on_unimplemented.rs

@@ -22,18 +22,15 @@ pub struct OnUnimplementedDirective {
     pub message: Option<OnUnimplementedFormatString>,
     pub label: Option<OnUnimplementedFormatString>,
     pub note: Option<OnUnimplementedFormatString>,
+    pub enclosing_scope: Option<OnUnimplementedFormatString>,
 }
 
+#[derive(Default)]
 pub struct OnUnimplementedNote {
     pub message: Option<String>,
     pub label: Option<String>,
     pub note: Option<String>,
-}
-
-impl OnUnimplementedNote {
-    pub fn empty() -> Self {
-        OnUnimplementedNote { message: None, label: None, note: None }
-    }
+    pub enclosing_scope: Option<String>,
 }
 
 fn parse_error(
@@ -85,24 +82,33 @@ impl<'tcx> OnUnimplementedDirective {
         let mut message = None;
         let mut label = None;
         let mut note = None;
+        let mut enclosing_scope = None;
         let mut subcommands = vec![];
+
+        let parse_value = |value_str| {
+                OnUnimplementedFormatString::try_parse(tcx, trait_def_id, value_str, span)
+                    .map(Some)
+            };
+
         for item in item_iter {
             if item.check_name(sym::message) && message.is_none() {
                 if let Some(message_) = item.value_str() {
-                    message = Some(OnUnimplementedFormatString::try_parse(
-                        tcx, trait_def_id, message_, span)?);
+                    message = parse_value(message_)?;
                     continue;
                 }
             } else if item.check_name(sym::label) && label.is_none() {
                 if let Some(label_) = item.value_str() {
-                    label = Some(OnUnimplementedFormatString::try_parse(
-                        tcx, trait_def_id, label_, span)?);
+                    label = parse_value(label_)?;
                     continue;
                 }
             } else if item.check_name(sym::note) && note.is_none() {
                 if let Some(note_) = item.value_str() {
-                    note = Some(OnUnimplementedFormatString::try_parse(
-                        tcx, trait_def_id, note_, span)?);
+                    note = parse_value(note_)?;
+                    continue;
+                }
+            } else if item.check_name(sym::enclosing_scope) && enclosing_scope.is_none() {
+                if let Some(enclosing_scope_) = item.value_str() {
+                    enclosing_scope = parse_value(enclosing_scope_)?;
                     continue;
                 }
             } else if item.check_name(sym::on) && is_root &&
@@ -130,7 +136,14 @@ impl<'tcx> OnUnimplementedDirective {
         if errored {
             Err(ErrorReported)
         } else {
-            Ok(OnUnimplementedDirective { condition, message, label, subcommands, note })
+            Ok(OnUnimplementedDirective {
+                condition,
+                subcommands,
+                message,
+                label,
+                note,
+                enclosing_scope
+            })
         }
     }
 
@@ -157,6 +170,7 @@ impl<'tcx> OnUnimplementedDirective {
                 label: Some(OnUnimplementedFormatString::try_parse(
                     tcx, trait_def_id, value, attr.span)?),
                 note: None,
+                enclosing_scope: None,
             }))
         } else {
             return Err(ErrorReported);
@@ -174,6 +188,7 @@ impl<'tcx> OnUnimplementedDirective {
         let mut message = None;
         let mut label = None;
         let mut note = None;
+        let mut enclosing_scope = None;
         info!("evaluate({:?}, trait_ref={:?}, options={:?})", self, trait_ref, options);
 
         for command in self.subcommands.iter().chain(Some(self)).rev() {
@@ -202,6 +217,10 @@ impl<'tcx> OnUnimplementedDirective {
             if let Some(ref note_) = command.note {
                 note = Some(note_.clone());
             }
+
+            if let Some(ref enclosing_scope_) = command.enclosing_scope {
+                enclosing_scope = Some(enclosing_scope_.clone());
+            }
         }
 
         let options: FxHashMap<Symbol, String> = options.into_iter()
@@ -211,6 +230,7 @@ impl<'tcx> OnUnimplementedDirective {
             label: label.map(|l| l.format(tcx, trait_ref, &options)),
             message: message.map(|m| m.format(tcx, trait_ref, &options)),
             note: note.map(|n| n.format(tcx, trait_ref, &options)),
+            enclosing_scope: enclosing_scope.map(|e_s| e_s.format(tcx, trait_ref, &options)),
         }
     }
 }