Auto merge of rust-lang#126093 - cuviper:beta-next, r=cuviper

[beta] backports

- Fix insufficient logic when searching for the underlying allocation rust-lang#124761
- Handle field projections like slice indexing in invalid_reference_casting rust-lang#124908
- Handle Deref expressions in invalid_reference_casting rust-lang#124978
- Fix ICE in non-operand `aggregate_raw_ptr` instrinsic codegen rust-lang#125184
- Wrap Context.ext in AssertUnwindSafe rust-lang#125392
- Revert problematic opaque type change rust-lang#125489
- ast: Revert a breaking attribute visiting order change rust-lang#125734
- Update to LLVM 18.1.7 rust-lang#126061
- Revert "Disallow ambiguous attributes on expressions" on beta rust-lang#126102 / rust-lang#126101
- Silence double-symlink errors while building solaris toolchain rust-lang#126011

r? cuviper

Author: bors

compiler/rustc_ast/src/visit.rs

@@ -826,10 +826,10 @@ pub fn walk_assoc_item<'a, V: Visitor<'a>>(
     ctxt: AssocCtxt,
 ) -> V::Result {
     let &Item { id: _, span: _, ident, ref vis, ref attrs, ref kind, tokens: _ } = item;
-    walk_list!(visitor, visit_attribute, attrs);
     try_visit!(visitor.visit_vis(vis));
     try_visit!(visitor.visit_ident(ident));
     try_visit!(kind.walk(item, ctxt, visitor));
+    walk_list!(visitor, visit_attribute, attrs);
     V::Result::output()
 }
 

compiler/rustc_codegen_ssa/src/mir/rvalue.rs

@@ -120,7 +120,11 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 bx.write_operand_repeatedly(cg_elem, count, dest);
             }
 
-            mir::Rvalue::Aggregate(ref kind, ref operands) => {
+            // This implementation does field projection, so never use it for `RawPtr`,
+            // which will always be fine with the `codegen_rvalue_operand` path below.
+            mir::Rvalue::Aggregate(ref kind, ref operands)
+                if !matches!(**kind, mir::AggregateKind::RawPtr(..)) =>
+            {
                 let (variant_index, variant_dest, active_field_index) = match **kind {
                     mir::AggregateKind::Adt(_, variant_index, _, _, active_field_index) => {
                         let variant_dest = dest.project_downcast(bx, variant_index);

compiler/rustc_infer/src/infer/mod.rs

@@ -945,27 +945,14 @@ impl<'tcx> InferCtxt<'tcx> {
             (&ty::Infer(ty::TyVar(a_vid)), &ty::Infer(ty::TyVar(b_vid))) => {
                 return Err((a_vid, b_vid));
             }
-            // We don't silently want to constrain hidden types here, so we assert that either one side is
-            // an infer var, so it'll get constrained to whatever the other side is, or there are no opaque
-            // types involved.
-            // We don't expect this to actually get hit, but if it does, we now at least know how to write
-            // a test for it.
-            (_, ty::Infer(ty::TyVar(_))) => {}
-            (ty::Infer(ty::TyVar(_)), _) => {}
-            _ if r_a != r_b && (r_a, r_b).has_opaque_types() => {
-                span_bug!(
-                    cause.span(),
-                    "opaque types got hidden types registered from within subtype predicate: {r_a:?} vs {r_b:?}"
-                )
-            }
             _ => {}
         }
 
         self.enter_forall(predicate, |ty::SubtypePredicate { a_is_expected, a, b }| {
             if a_is_expected {
-                Ok(self.at(cause, param_env).sub(DefineOpaqueTypes::Yes, a, b))
+                Ok(self.at(cause, param_env).sub(DefineOpaqueTypes::No, a, b))
             } else {
-                Ok(self.at(cause, param_env).sup(DefineOpaqueTypes::Yes, b, a))
+                Ok(self.at(cause, param_env).sup(DefineOpaqueTypes::No, b, a))
             }
         })
     }

compiler/rustc_lint/src/reference_casting.rs

@@ -198,6 +198,16 @@ fn is_cast_to_bigger_memory_layout<'tcx>(
     let e_alloc = cx.expr_or_init(e);
     let e_alloc =
         if let ExprKind::AddrOf(_, _, inner_expr) = e_alloc.kind { inner_expr } else { e_alloc };
+
+    // if the current expr looks like this `&mut expr[index]` then just looking
+    // at `expr[index]` won't give us the underlying allocation, so we just skip it
+    // the same logic applies field access `&mut expr.field` and reborrows `&mut *expr`.
+    if let ExprKind::Index(..) | ExprKind::Field(..) | ExprKind::Unary(UnOp::Deref, ..) =
+        e_alloc.kind
+    {
+        return None;
+    }
+
     let alloc_ty = cx.typeck_results().node_type(e_alloc.hir_id);
 
     // if we do not find it we bail out, as this may not be UB

compiler/rustc_parse/messages.ftl

@@ -624,8 +624,6 @@ parse_or_pattern_not_allowed_in_let_binding = top-level or-patterns are not allo
 parse_out_of_range_hex_escape = out of range hex escape
     .label = must be a character in the range [\x00-\x7f]
 
-parse_outer_attr_ambiguous = ambiguous outer attributes
-
 parse_outer_attr_explanation = outer attributes, like `#[test]`, annotate the item following them
 
 parse_outer_attribute_not_allowed_on_if_else = outer attributes are not allowed on `if` and `else` branches

compiler/rustc_parse/src/errors.rs

@@ -495,15 +495,6 @@ pub(crate) struct OuterAttributeNotAllowedOnIfElse {
     pub attributes: Span,
 }
 
-#[derive(Diagnostic)]
-#[diag(parse_outer_attr_ambiguous)]
-pub(crate) struct AmbiguousOuterAttributes {
-    #[primary_span]
-    pub span: Span,
-    #[subdiagnostic]
-    pub sugg: WrapInParentheses,
-}
-
 #[derive(Diagnostic)]
 #[diag(parse_missing_in_in_for_loop)]
 pub(crate) struct MissingInInForLoop {

compiler/rustc_parse/src/parser/expr.rs

@@ -327,9 +327,7 @@ impl<'a> Parser<'a> {
                 this.parse_expr_assoc_with(prec + prec_adjustment, LhsExpr::NotYetParsed)
             })?;
 
-            self.error_ambiguous_outer_attrs(&lhs, lhs_span, rhs.span);
-            let span = lhs_span.to(rhs.span);
-
+            let span = self.mk_expr_sp(&lhs, lhs_span, rhs.span);
             lhs = match op {
                 AssocOp::Add
                 | AssocOp::Subtract
@@ -428,18 +426,6 @@ impl<'a> Parser<'a> {
         });
     }
 
-    fn error_ambiguous_outer_attrs(&self, lhs: &P<Expr>, lhs_span: Span, rhs_span: Span) {
-        if let Some(attr) = lhs.attrs.iter().find(|a| a.style == AttrStyle::Outer) {
-            self.dcx().emit_err(errors::AmbiguousOuterAttributes {
-                span: attr.span.to(rhs_span),
-                sugg: errors::WrapInParentheses::Expression {
-                    left: attr.span.shrink_to_lo(),
-                    right: lhs_span.shrink_to_hi(),
-                },
-            });
-        }
-    }
-
     /// Possibly translate the current token to an associative operator.
     /// The method does not advance the current token.
     ///
@@ -520,8 +506,7 @@ impl<'a> Parser<'a> {
             None
         };
         let rhs_span = rhs.as_ref().map_or(cur_op_span, |x| x.span);
-        self.error_ambiguous_outer_attrs(&lhs, lhs.span, rhs_span);
-        let span = lhs.span.to(rhs_span);
+        let span = self.mk_expr_sp(&lhs, lhs.span, rhs_span);
         let limits =
             if op == AssocOp::DotDot { RangeLimits::HalfOpen } else { RangeLimits::Closed };
         let range = self.mk_range(Some(lhs), rhs, limits);
@@ -737,8 +722,7 @@ impl<'a> Parser<'a> {
         expr_kind: fn(P<Expr>, P<Ty>) -> ExprKind,
     ) -> PResult<'a, P<Expr>> {
         let mk_expr = |this: &mut Self, lhs: P<Expr>, rhs: P<Ty>| {
-            this.error_ambiguous_outer_attrs(&lhs, lhs_span, rhs.span);
-            this.mk_expr(lhs_span.to(rhs.span), expr_kind(lhs, rhs))
+            this.mk_expr(this.mk_expr_sp(&lhs, lhs_span, rhs.span), expr_kind(lhs, rhs))
         };
 
         // Save the state of the parser before parsing type normally, in case there is a
@@ -3829,6 +3813,16 @@ impl<'a> Parser<'a> {
         self.mk_expr(span, ExprKind::Err(guar))
     }
 
+    /// Create expression span ensuring the span of the parent node
+    /// is larger than the span of lhs and rhs, including the attributes.
+    fn mk_expr_sp(&self, lhs: &P<Expr>, lhs_span: Span, rhs_span: Span) -> Span {
+        lhs.attrs
+            .iter()
+            .find(|a| a.style == AttrStyle::Outer)
+            .map_or(lhs_span, |a| a.span)
+            .to(rhs_span)
+    }
+
     fn collect_tokens_for_expr(
         &mut self,
         attrs: AttrWrapper,

library/core/src/task/wake.rs

@@ -5,6 +5,7 @@ use crate::mem::transmute;
 use crate::any::Any;
 use crate::fmt;
 use crate::marker::PhantomData;
+use crate::panic::AssertUnwindSafe;
 use crate::ptr;
 
 /// A `RawWaker` allows the implementor of a task executor to create a [`Waker`]
@@ -236,7 +237,7 @@ enum ExtData<'a> {
 pub struct Context<'a> {
     waker: &'a Waker,
     local_waker: &'a LocalWaker,
-    ext: ExtData<'a>,
+    ext: AssertUnwindSafe<ExtData<'a>>,
     // Ensure we future-proof against variance changes by forcing
     // the lifetime to be invariant (argument-position lifetimes
     // are contravariant while return-position lifetimes are
@@ -279,7 +280,9 @@ impl<'a> Context<'a> {
     #[unstable(feature = "context_ext", issue = "123392")]
     #[rustc_const_unstable(feature = "const_waker", issue = "102012")]
     pub const fn ext(&mut self) -> &mut dyn Any {
-        match &mut self.ext {
+        // FIXME: this field makes Context extra-weird about unwind safety
+        // can we justify AssertUnwindSafe if we stabilize this? do we care?
+        match &mut *self.ext {
             ExtData::Some(data) => *data,
             ExtData::None(unit) => unit,
         }
@@ -353,7 +356,7 @@ impl<'a> ContextBuilder<'a> {
     #[rustc_const_unstable(feature = "const_waker", issue = "102012")]
     #[unstable(feature = "context_ext", issue = "123392")]
     pub const fn from(cx: &'a mut Context<'_>) -> Self {
-        let ext = match &mut cx.ext {
+        let ext = match &mut *cx.ext {
             ExtData::Some(ext) => ExtData::Some(*ext),
             ExtData::None(()) => ExtData::None(()),
         };
@@ -396,7 +399,7 @@ impl<'a> ContextBuilder<'a> {
     #[rustc_const_unstable(feature = "const_waker", issue = "102012")]
     pub const fn build(self) -> Context<'a> {
         let ContextBuilder { waker, local_waker, ext, _marker, _marker2 } = self;
-        Context { waker, local_waker, ext, _marker, _marker2 }
+        Context { waker, local_waker, ext: AssertUnwindSafe(ext), _marker, _marker2 }
     }
 }
 

src/ci/docker/host-x86_64/dist-various-2/build-solaris-toolchain.sh

@@ -54,7 +54,7 @@ apt-get clean
 # This makes all those symlinks.
 for lib in $(find -name '*.so.*'); do
   target=${lib%.so.*}.so
-  [ -e $target ] || ln -s ${lib##*/} $target
+  ln -s ${lib##*/} $target || echo "warning: silenced error symlinking $lib"
 done
 
 # Remove Solaris 11 functions that are optionally used by libbacktrace.