Auto merge of rust-lang#136697 - matthiaskrgr:rollup-eww4vl9, r=matth…

…iaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#134367 (Stabilize `feature(trait_upcasting)`)
 - rust-lang#135940 (Update toolstate maintainers)
 - rust-lang#135945 (Remove some unnecessary parens in `assert!` conditions)
 - rust-lang#136577 (Pattern Migration 2024: try to suggest eliding redundant binding modifiers)
 - rust-lang#136598 (Fix suggestion for `dependency_on_unit_never_type_fallback` involving closures + format args expansions)
 - rust-lang#136653 (Remove dead code from rustc_codegen_llvm and the LLVM wrapper)
 - rust-lang#136664 (replace one `.map_or(true, ...)` with `.is_none_or(...)`)

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

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -69,19 +69,6 @@ pub enum LLVMRustResult {
     Failure,
 }
 
-/// Translation of LLVM's MachineTypes enum, defined in llvm\include\llvm\BinaryFormat\COFF.h.
-///
-/// We include only architectures supported on Windows.
-#[derive(Copy, Clone, PartialEq)]
-#[repr(C)]
-pub enum LLVMMachineType {
-    AMD64 = 0x8664,
-    I386 = 0x14c,
-    ARM64 = 0xaa64,
-    ARM64EC = 0xa641,
-    ARM = 0x01c0,
-}
-
 /// Must match the layout of `LLVMRustModuleFlagMergeBehavior`.
 ///
 /// When merging modules (e.g. during LTO), their metadata flags are combined. Conflicts are
@@ -645,16 +632,6 @@ pub enum ThreadLocalMode {
     LocalExec,
 }
 
-/// LLVMRustTailCallKind
-#[derive(Copy, Clone)]
-#[repr(C)]
-pub enum TailCallKind {
-    None,
-    Tail,
-    MustTail,
-    NoTail,
-}
-
 /// LLVMRustChecksumKind
 #[derive(Copy, Clone)]
 #[repr(C)]
@@ -773,7 +750,6 @@ pub struct Builder<'a>(InvariantOpaque<'a>);
 #[repr(C)]
 pub struct PassManager<'a>(InvariantOpaque<'a>);
 unsafe extern "C" {
-    pub type Pass;
     pub type TargetMachine;
     pub type Archive;
 }
@@ -799,7 +775,6 @@ unsafe extern "C" {
 }
 
 pub type DiagnosticHandlerTy = unsafe extern "C" fn(&DiagnosticInfo, *mut c_void);
-pub type InlineAsmDiagHandlerTy = unsafe extern "C" fn(&SMDiagnostic, *const c_void, c_uint);
 
 pub mod debuginfo {
     use std::ptr;
@@ -853,7 +828,6 @@ pub mod debuginfo {
     pub type DIFile = DIScope;
     pub type DILexicalBlock = DIScope;
     pub type DISubprogram = DIScope;
-    pub type DINameSpace = DIScope;
     pub type DIType = DIDescriptor;
     pub type DIBasicType = DIType;
     pub type DIDerivedType = DIType;
@@ -1809,7 +1783,6 @@ unsafe extern "C" {
         Name: *const c_char,
         NameLen: size_t,
     ) -> Option<&Value>;
-    pub fn LLVMRustSetTailCallKind(CallInst: &Value, TKC: TailCallKind);
 
     // Operations on attributes
     pub fn LLVMRustCreateAttrNoValue(C: &Context, attr: AttributeKind) -> &Attribute;
@@ -2586,8 +2559,6 @@ unsafe extern "C" {
 
     pub fn LLVMRustGetElementTypeArgIndex(CallSite: &Value) -> i32;
 
-    pub fn LLVMRustIsBitcode(ptr: *const u8, len: usize) -> bool;
-
     pub fn LLVMRustLLVMHasZlibCompressionForDebugSymbols() -> bool;
 
     pub fn LLVMRustLLVMHasZstdCompressionForDebugSymbols() -> bool;

compiler/rustc_feature/src/accepted.rs

@@ -400,6 +400,9 @@ declare_features! (
     /// Allows `#[track_caller]` to be used which provides
     /// accurate caller location reporting during panic (RFC 2091).
     (accepted, track_caller, "1.46.0", Some(47809)),
+    /// Allows dyn upcasting trait objects via supertraits.
+    /// Dyn upcasting is casting, e.g., `dyn Foo -> dyn Bar` where `Foo: Bar`.
+    (accepted, trait_upcasting, "CURRENT_RUSTC_VERSION", Some(65991)),
     /// Allows #[repr(transparent)] on univariant enums (RFC 2645).
     (accepted, transparent_enums, "1.42.0", Some(60405)),
     /// Allows indexing tuples.

compiler/rustc_feature/src/unstable.rs

@@ -634,9 +634,6 @@ declare_features! (
     (unstable, thread_local, "1.0.0", Some(29594)),
     /// Allows defining `trait X = A + B;` alias items.
     (unstable, trait_alias, "1.24.0", Some(41517)),
-    /// Allows dyn upcasting trait objects via supertraits.
-    /// Dyn upcasting is casting, e.g., `dyn Foo -> dyn Bar` where `Foo: Bar`.
-    (unstable, trait_upcasting, "1.56.0", Some(65991)),
     /// Allows for transmuting between arrays with sizes that contain generic consts.
     (unstable, transmute_generic_consts, "1.70.0", Some(109929)),
     /// Allows #[repr(transparent)] on unions (RFC 2645).

compiler/rustc_hir_typeck/src/coercion.rs

@@ -605,7 +605,6 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         )];
 
         let mut has_unsized_tuple_coercion = false;
-        let mut has_trait_upcasting_coercion = None;
 
         // Keep resolving `CoerceUnsized` and `Unsize` predicates to avoid
         // emitting a coercion in cases like `Foo<$1>` -> `Foo<$2>`, where
@@ -690,13 +689,6 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
                     // these here and emit a feature error if coercion doesn't fail
                     // due to another reason.
                     match impl_source {
-                        traits::ImplSource::Builtin(
-                            BuiltinImplSource::TraitUpcasting { .. },
-                            _,
-                        ) => {
-                            has_trait_upcasting_coercion =
-                                Some((trait_pred.self_ty(), trait_pred.trait_ref.args.type_at(1)));
-                        }
                         traits::ImplSource::Builtin(BuiltinImplSource::TupleUnsizing, _) => {
                             has_unsized_tuple_coercion = true;
                         }
@@ -707,21 +699,6 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
             }
         }
 
-        if let Some((sub, sup)) = has_trait_upcasting_coercion
-            && !self.tcx().features().trait_upcasting()
-        {
-            // Renders better when we erase regions, since they're not really the point here.
-            let (sub, sup) = self.tcx.erase_regions((sub, sup));
-            let mut err = feature_err(
-                &self.tcx.sess,
-                sym::trait_upcasting,
-                self.cause.span,
-                format!("cannot cast `{sub}` to `{sup}`, trait upcasting coercion is experimental"),
-            );
-            err.note(format!("required when coercing `{source}` into `{target}`"));
-            err.emit();
-        }
-
         if has_unsized_tuple_coercion && !self.tcx.features().unsized_tuple_coercion() {
             feature_err(
                 &self.tcx.sess,

compiler/rustc_hir_typeck/src/fallback.rs

@@ -651,6 +651,7 @@ impl<'tcx> Visitor<'tcx> for AnnotateUnitFallbackVisitor<'_, 'tcx> {
         if let Some(ty) = self.fcx.typeck_results.borrow().node_type_opt(inf_id)
             && let Some(vid) = self.fcx.root_vid(ty)
             && self.reachable_vids.contains(&vid)
+            && inf_span.can_be_used_for_suggestions()
         {
             return ControlFlow::Break(errors::SuggestAnnotation::Unit(inf_span));
         }
@@ -662,7 +663,7 @@ impl<'tcx> Visitor<'tcx> for AnnotateUnitFallbackVisitor<'_, 'tcx> {
         &mut self,
         qpath: &'tcx rustc_hir::QPath<'tcx>,
         id: HirId,
-        _span: Span,
+        span: Span,
     ) -> Self::Result {
         let arg_segment = match qpath {
             hir::QPath::Resolved(_, path) => {
@@ -674,13 +675,21 @@ impl<'tcx> Visitor<'tcx> for AnnotateUnitFallbackVisitor<'_, 'tcx> {
             }
         };
         // Alternatively, try to turbofish `::<_, (), _>`.
-        if let Some(def_id) = self.fcx.typeck_results.borrow().qpath_res(qpath, id).opt_def_id() {
+        if let Some(def_id) = self.fcx.typeck_results.borrow().qpath_res(qpath, id).opt_def_id()
+            && span.can_be_used_for_suggestions()
+        {
             self.suggest_for_segment(arg_segment, def_id, id)?;
         }
         hir::intravisit::walk_qpath(self, qpath, id)
     }
 
     fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) -> Self::Result {
+        if let hir::ExprKind::Closure(&hir::Closure { body, .. })
+        | hir::ExprKind::ConstBlock(hir::ConstBlock { body, .. }) = expr.kind
+        {
+            self.visit_body(self.fcx.tcx.hir().body(body))?;
+        }
+
         // Try to suggest adding an explicit qself `()` to a trait method path.
         // i.e. changing `Default::default()` to `<() as Default>::default()`.
         if let hir::ExprKind::Path(hir::QPath::Resolved(None, path)) = expr.kind
@@ -691,17 +700,21 @@ impl<'tcx> Visitor<'tcx> for AnnotateUnitFallbackVisitor<'_, 'tcx> {
             && let Some(vid) = self.fcx.root_vid(self_ty)
             && self.reachable_vids.contains(&vid)
             && let [.., trait_segment, _method_segment] = path.segments
+            && expr.span.can_be_used_for_suggestions()
         {
             let span = path.span.shrink_to_lo().to(trait_segment.ident.span);
             return ControlFlow::Break(errors::SuggestAnnotation::Path(span));
         }
+
         // Or else, try suggesting turbofishing the method args.
         if let hir::ExprKind::MethodCall(segment, ..) = expr.kind
             && let Some(def_id) =
                 self.fcx.typeck_results.borrow().type_dependent_def_id(expr.hir_id)
+            && expr.span.can_be_used_for_suggestions()
         {
             self.suggest_for_segment(segment, def_id, expr.hir_id)?;
         }
+
         hir::intravisit::walk_expr(self, expr)
     }
 
@@ -712,6 +725,7 @@ impl<'tcx> Visitor<'tcx> for AnnotateUnitFallbackVisitor<'_, 'tcx> {
             && let Some(ty) = self.fcx.typeck_results.borrow().node_type_opt(local.hir_id)
             && let Some(vid) = self.fcx.root_vid(ty)
             && self.reachable_vids.contains(&vid)
+            && local.span.can_be_used_for_suggestions()
         {
             return ControlFlow::Break(errors::SuggestAnnotation::Local(
                 local.pat.span.shrink_to_hi(),

compiler/rustc_hir_typeck/src/pat.rs

@@ -812,7 +812,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         // Determine the binding mode...
         let bm = match user_bind_annot {
-            BindingMode(ByRef::No, Mutability::Mut) if matches!(def_br, ByRef::Yes(_)) => {
+            BindingMode(ByRef::No, Mutability::Mut) if let ByRef::Yes(def_br_mutbl) = def_br => {
                 // Only mention the experimental `mut_ref` feature if if we're in edition 2024 and
                 // using other experimental matching features compatible with it.
                 if pat.span.at_least_rust_2024()
@@ -834,22 +834,22 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     // `mut` resets the binding mode on edition <= 2021
                     self.add_rust_2024_migration_desugared_pat(
                         pat_info.top_info.hir_id,
-                        pat.span,
+                        pat,
                         ident.span,
-                        "requires binding by-value, but the implicit default is by-reference",
+                        def_br_mutbl,
                     );
                     BindingMode(ByRef::No, Mutability::Mut)
                 }
             }
             BindingMode(ByRef::No, mutbl) => BindingMode(def_br, mutbl),
             BindingMode(ByRef::Yes(_), _) => {
-                if matches!(def_br, ByRef::Yes(_)) {
+                if let ByRef::Yes(def_br_mutbl) = def_br {
                     // `ref`/`ref mut` overrides the binding mode on edition <= 2021
                     self.add_rust_2024_migration_desugared_pat(
                         pat_info.top_info.hir_id,
-                        pat.span,
+                        pat,
                         ident.span,
-                        "cannot override to bind by-reference when that is the implicit default",
+                        def_br_mutbl,
                     );
                 }
                 user_bind_annot
@@ -2386,9 +2386,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     pat_info.binding_mode = ByRef::No;
                     self.add_rust_2024_migration_desugared_pat(
                         pat_info.top_info.hir_id,
-                        pat.span,
+                        pat,
                         inner.span,
-                        "cannot implicitly match against multiple layers of reference",
+                        inh_mut,
                     )
                 }
             }
@@ -2778,33 +2778,65 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     fn add_rust_2024_migration_desugared_pat(
         &self,
         pat_id: HirId,
-        subpat_span: Span,
+        subpat: &'tcx Pat<'tcx>,
         cutoff_span: Span,
-        detailed_label: &str,
+        def_br_mutbl: Mutability,
     ) {
         // Try to trim the span we're labeling to just the `&` or binding mode that's an issue.
         // If the subpattern's span is is from an expansion, the emitted label will not be trimmed.
         let source_map = self.tcx.sess.source_map();
         let cutoff_span = source_map
-            .span_extend_prev_while(cutoff_span, char::is_whitespace)
+            .span_extend_prev_while(cutoff_span, |c| c.is_whitespace() || c == '(')
             .unwrap_or(cutoff_span);
-        // Ensure we use the syntax context and thus edition of `subpat_span`; this will be a hard
+        // Ensure we use the syntax context and thus edition of `subpat.span`; this will be a hard
         // error if the subpattern is of edition >= 2024.
-        let trimmed_span = subpat_span.until(cutoff_span).with_ctxt(subpat_span.ctxt());
+        let trimmed_span = subpat.span.until(cutoff_span).with_ctxt(subpat.span.ctxt());
+
+        let mut typeck_results = self.typeck_results.borrow_mut();
+        let mut table = typeck_results.rust_2024_migration_desugared_pats_mut();
+        // FIXME(ref_pat_eat_one_layer_2024): The migration diagnostic doesn't know how to track the
+        // default binding mode in the presence of Rule 3 or Rule 5. As a consequence, the labels it
+        // gives for default binding modes are wrong, as well as suggestions based on the default
+        // binding mode. This keeps it from making those suggestions, as doing so could panic.
+        let info = table.entry(pat_id).or_insert_with(|| ty::Rust2024IncompatiblePatInfo {
+            primary_labels: Vec::new(),
+            bad_modifiers: false,
+            bad_ref_pats: false,
+            suggest_eliding_modes: !self.tcx.features().ref_pat_eat_one_layer_2024()
+                && !self.tcx.features().ref_pat_eat_one_layer_2024_structural(),
+        });
 
         // Only provide a detailed label if the problematic subpattern isn't from an expansion.
         // In the case that it's from a macro, we'll add a more detailed note in the emitter.
-        let desc = if subpat_span.from_expansion() {
-            "default binding mode is reset within expansion"
+        let from_expansion = subpat.span.from_expansion();
+        let primary_label = if from_expansion {
+            // NB: This wording assumes the only expansions that can produce problematic reference
+            // patterns and bindings are macros. If a desugaring or AST pass is added that can do
+            // so, we may want to inspect the span's source callee or macro backtrace.
+            "occurs within macro expansion".to_owned()
         } else {
-            detailed_label
+            let pat_kind = if let PatKind::Binding(user_bind_annot, _, _, _) = subpat.kind {
+                info.bad_modifiers |= true;
+                // If the user-provided binding modifier doesn't match the default binding mode, we'll
+                // need to suggest reference patterns, which can affect other bindings.
+                // For simplicity, we opt to suggest making the pattern fully explicit.
+                info.suggest_eliding_modes &=
+                    user_bind_annot == BindingMode(ByRef::Yes(def_br_mutbl), Mutability::Not);
+                "binding modifier"
+            } else {
+                info.bad_ref_pats |= true;
+                // For simplicity, we don't try to suggest eliding reference patterns. Thus, we'll
+                // suggest adding them instead, which can affect the types assigned to bindings.
+                // As such, we opt to suggest making the pattern fully explicit.
+                info.suggest_eliding_modes = false;
+                "reference pattern"
+            };
+            let dbm_str = match def_br_mutbl {
+                Mutability::Not => "ref",
+                Mutability::Mut => "ref mut",
+            };
+            format!("{pat_kind} not allowed under `{dbm_str}` default binding mode")
         };
-
-        self.typeck_results
-            .borrow_mut()
-            .rust_2024_migration_desugared_pats_mut()
-            .entry(pat_id)
-            .or_default()
-            .push((trimmed_span, desc.to_owned()));
+        info.primary_labels.push((trimmed_span, primary_label));
     }
 }

compiler/rustc_lint/src/deref_into_dyn_supertrait.rs

@@ -1,6 +1,5 @@
 use rustc_hir::{self as hir, LangItem};
 use rustc_middle::ty;
-use rustc_session::lint::FutureIncompatibilityReason;
 use rustc_session::{declare_lint, declare_lint_pass};
 use rustc_span::sym;
 use rustc_trait_selection::traits::supertraits;
@@ -9,11 +8,12 @@ use crate::lints::{SupertraitAsDerefTarget, SupertraitAsDerefTargetLabel};
 use crate::{LateContext, LateLintPass, LintContext};
 
 declare_lint! {
-    /// The `deref_into_dyn_supertrait` lint is output whenever there is a use of the
-    /// `Deref` implementation with a `dyn SuperTrait` type as `Output`.
+    /// The `deref_into_dyn_supertrait` lint is emitted whenever there is a `Deref` implementation
+    /// for `dyn SubTrait` with a `dyn SuperTrait` type as the `Output` type.
     ///
-    /// These implementations will become shadowed when the `trait_upcasting` feature is stabilized.
-    /// The `deref` functions will no longer be called implicitly, so there might be behavior change.
+    /// These implementations are "shadowed" by trait upcasting (stabilized since
+    /// CURRENT_RUSTC_VERSION). The `deref` functions is no longer called implicitly, which might
+    /// change behavior compared to previous rustc versions.
     ///
     /// ### Example
     ///
@@ -43,15 +43,14 @@ declare_lint! {
     ///
     /// ### Explanation
     ///
-    /// The dyn upcasting coercion feature adds new coercion rules, taking priority
-    /// over certain other coercion rules, which will cause some behavior change.
+    /// The trait upcasting coercion added a new coercion rule, taking priority over certain other
+    /// coercion rules, which causes some behavior change compared to older `rustc` versions.
+    ///
+    /// `deref` can be still called explicitly, it just isn't called as part of a deref coercion
+    /// (since trait upcasting coercion takes priority).
     pub DEREF_INTO_DYN_SUPERTRAIT,
-    Warn,
-    "`Deref` implementation usage with a supertrait trait object for output might be shadowed in the future",
-    @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseSemanticsChange,
-        reference: "issue #89460 <https://github.com/rust-lang/rust/issues/89460>",
-    };
+    Allow,
+    "`Deref` implementation with a supertrait trait object for output is shadowed by trait upcasting",
 }
 
 declare_lint_pass!(DerefIntoDynSupertrait => [DEREF_INTO_DYN_SUPERTRAIT]);