Auto merge of rust-lang#3077 - rust-lang:rustup-2023-09-23, r=saethlin

Automatic sync from rustc

Author: bors

compiler/rustc_error_codes/src/error_codes/E0647.md

@@ -7,7 +7,7 @@ Erroneous code example:
 
 #[start]
 fn start(_: isize, _: *const *const u8) -> isize where (): Copy {
-    //^ error: start function is not allowed to have a where clause
+    //^ error: `#[start]` function is not allowed to have a where clause
     0
 }
 ```

compiler/rustc_errors/src/diagnostic.rs

@@ -151,7 +151,12 @@ impl fmt::Display for DiagnosticLocation {
 #[derive(Clone, Debug, PartialEq, Eq, Hash, Encodable, Decodable)]
 pub enum DiagnosticId {
     Error(String),
-    Lint { name: String, has_future_breakage: bool, is_force_warn: bool },
+    Lint {
+        name: String,
+        /// Indicates whether this lint should show up in cargo's future breakage report.
+        has_future_breakage: bool,
+        is_force_warn: bool,
+    },
 }
 
 /// A "sub"-diagnostic attached to a parent diagnostic.
@@ -301,6 +306,7 @@ impl Diagnostic {
         }
     }
 
+    /// Indicates whether this diagnostic should show up in cargo's future breakage report.
     pub fn has_future_breakage(&self) -> bool {
         match self.code {
             Some(DiagnosticId::Lint { has_future_breakage, .. }) => has_future_breakage,

compiler/rustc_errors/src/lib.rs

@@ -519,7 +519,7 @@ pub struct HandlerFlags {
     /// If false, warning-level lints are suppressed.
     /// (rustc: see `--allow warnings` and `--cap-lints`)
     pub can_emit_warnings: bool,
-    /// If true, error-level diagnostics are upgraded to bug-level.
+    /// If Some, the Nth error-level diagnostic is upgraded to bug-level.
     /// (rustc: see `-Z treat-err-as-bug`)
     pub treat_err_as_bug: Option<NonZeroUsize>,
     /// If true, immediately emit diagnostics that would otherwise be buffered.
@@ -1719,19 +1719,17 @@ impl HandlerInner {
             match (
                 self.err_count() + self.lint_err_count,
                 self.delayed_bug_count(),
-                self.flags.treat_err_as_bug.map(|c| c.get()).unwrap_or(0),
+                self.flags.treat_err_as_bug.map(|c| c.get()).unwrap(),
             ) {
                 (1, 0, 1) => panic!("aborting due to `-Z treat-err-as-bug=1`"),
                 (0, 1, 1) => panic!("aborting due delayed bug with `-Z treat-err-as-bug=1`"),
-                (count, delayed_count, as_bug) => {
+                (count, delayed_count, val) => {
                     if delayed_count > 0 {
                         panic!(
-                            "aborting after {count} errors and {delayed_count} delayed bugs due to `-Z treat-err-as-bug={as_bug}`",
+                            "aborting after {count} errors and {delayed_count} delayed bugs due to `-Z treat-err-as-bug={val}`",
                         )
                     } else {
-                        panic!(
-                            "aborting after {count} errors due to `-Z treat-err-as-bug={as_bug}`",
-                        )
+                        panic!("aborting after {count} errors due to `-Z treat-err-as-bug={val}`")
                     }
                 }
             }

compiler/rustc_hir_analysis/messages.ftl

@@ -270,20 +270,20 @@ hir_analysis_simd_ffi_highly_experimental = use of SIMD type{$snip} in FFI is hi
 hir_analysis_specialization_trait = implementing `rustc_specialization_trait` traits is unstable
     .help = add `#![feature(min_specialization)]` to the crate attributes to enable
 
-hir_analysis_start_function_parameters = start function is not allowed to have type parameters
-    .label = start function cannot have type parameters
+hir_analysis_start_function_parameters = `#[start]` function is not allowed to have type parameters
+    .label = `#[start]` function cannot have type parameters
 
-hir_analysis_start_function_where = start function is not allowed to have a `where` clause
-    .label = start function cannot have a `where` clause
+hir_analysis_start_function_where = `#[start]` function is not allowed to have a `where` clause
+    .label = `#[start]` function cannot have a `where` clause
 
-hir_analysis_start_not_async = `start` is not allowed to be `async`
-    .label = `start` is not allowed to be `async`
+hir_analysis_start_not_async = `#[start]` function is not allowed to be `async`
+    .label = `#[start]` is not allowed to be `async`
 
-hir_analysis_start_not_target_feature = `start` is not allowed to have `#[target_feature]`
-    .label = `start` is not allowed to have `#[target_feature]`
+hir_analysis_start_not_target_feature = `#[start]` function is not allowed to have `#[target_feature]`
+    .label = `#[start]` function is not allowed to have `#[target_feature]`
 
-hir_analysis_start_not_track_caller = `start` is not allowed to be `#[track_caller]`
-    .label = `start` is not allowed to be `#[track_caller]`
+hir_analysis_start_not_track_caller = `#[start]` function is not allowed to be `#[track_caller]`
+    .label = `#[start]` function is not allowed to be `#[track_caller]`
 
 hir_analysis_static_specialize = cannot specialize on `'static` lifetime
 

compiler/rustc_hir_analysis/src/check/check.rs

@@ -18,7 +18,7 @@ use rustc_infer::traits::{Obligation, TraitEngineExt as _};
 use rustc_lint_defs::builtin::REPR_TRANSPARENT_EXTERNAL_PRIVATE_FIELDS;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::middle::stability::EvalResult;
-use rustc_middle::traits::DefiningAnchor;
+use rustc_middle::traits::{DefiningAnchor, ObligationCauseCode};
 use rustc_middle::ty::fold::BottomUpFolder;
 use rustc_middle::ty::layout::{LayoutError, MAX_SIMD_LANES};
 use rustc_middle::ty::util::{Discr, IntTypeExt};
@@ -1626,6 +1626,25 @@ pub(super) fn check_generator_obligations(tcx: TyCtxt<'_>, def_id: LocalDefId) {
         let obligation = Obligation::new(tcx, cause.clone(), param_env, *predicate);
         fulfillment_cx.register_predicate_obligation(&infcx, obligation);
     }
+
+    if (tcx.features().unsized_locals || tcx.features().unsized_fn_params)
+        && let Some(generator) = tcx.mir_generator_witnesses(def_id)
+    {
+        for field_ty in generator.field_tys.iter() {
+            fulfillment_cx.register_bound(
+                &infcx,
+                param_env,
+                field_ty.ty,
+                tcx.require_lang_item(hir::LangItem::Sized, Some(field_ty.source_info.span)),
+                ObligationCause::new(
+                    field_ty.source_info.span,
+                    def_id,
+                    ObligationCauseCode::SizedGeneratorInterior(def_id),
+                ),
+            );
+        }
+    }
+
     let errors = fulfillment_cx.select_all_or_error(&infcx);
     debug!(?errors);
     if !errors.is_empty() {

compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs

@@ -1,7 +1,7 @@
 use rustc_errors::StashKey;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{self, Visitor};
-use rustc_hir::{self as hir, Expr, ImplItem, Item, Node, TraitItem};
+use rustc_hir::{self as hir, def, Expr, ImplItem, Item, Node, TraitItem};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
 use rustc_span::DUMMY_SP;
@@ -74,9 +74,14 @@ pub(super) fn find_opaque_ty_constraints_for_tait(tcx: TyCtxt<'_>, def_id: Local
 
         hidden.ty
     } else {
+        let mut parent_def_id = def_id;
+        while tcx.def_kind(parent_def_id) == def::DefKind::OpaqueTy {
+            // Account for `type Alias = impl Trait<Foo = impl Trait>;` (#116031)
+            parent_def_id = tcx.local_parent(parent_def_id);
+        }
         let reported = tcx.sess.emit_err(UnconstrainedOpaqueType {
             span: tcx.def_span(def_id),
-            name: tcx.item_name(tcx.local_parent(def_id).to_def_id()),
+            name: tcx.item_name(parent_def_id.to_def_id()),
             what: match tcx.hir().get(scope) {
                 _ if scope == hir::CRATE_HIR_ID => "module",
                 Node::Item(hir::Item { kind: hir::ItemKind::Mod(_), .. }) => "module",

compiler/rustc_hir_typeck/src/cast.rs

@@ -725,6 +725,9 @@ impl<'a, 'tcx> CastCheck<'tcx> {
                             },
                             // array-ptr-cast
                             Ptr(mt) => {
+                                if !fcx.type_is_sized_modulo_regions(fcx.param_env, mt.ty) {
+                                    return Err(CastError::IllegalCast);
+                                }
                                 self.check_ref_cast(fcx, TypeAndMut { mutbl, ty: inner_ty }, mt)
                             }
                             _ => Err(CastError::NonScalar),
@@ -735,15 +738,13 @@ impl<'a, 'tcx> CastCheck<'tcx> {
             }
             _ => return Err(CastError::NonScalar),
         };
-
         if let ty::Adt(adt_def, _) = *self.expr_ty.kind() {
             if adt_def.did().krate != LOCAL_CRATE {
                 if adt_def.variants().iter().any(VariantDef::is_field_list_non_exhaustive) {
                     return Err(CastError::ForeignNonExhaustiveAdt);
                 }
             }
         }
-
         match (t_from, t_cast) {
             // These types have invariants! can't cast into them.
             (_, Int(CEnum) | FnPtr) => Err(CastError::NonScalar),

compiler/rustc_hir_typeck/src/expr.rs

@@ -525,8 +525,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             _ => self.instantiate_value_path(segs, opt_ty, res, expr.span, expr.hir_id).0,
         };
 
-        if let ty::FnDef(did, ..) = *ty.kind() {
+        if let ty::FnDef(did, callee_args) = *ty.kind() {
             let fn_sig = ty.fn_sig(tcx);
+
+            // HACK: whenever we get a FnDef in a non-const context, enforce effects to get the
+            // default `host = true` to avoid inference errors later.
+            if tcx.hir().body_const_context(self.body_id).is_none() {
+                self.enforce_context_effects(expr.hir_id, qpath.span(), did, callee_args);
+            }
             if tcx.fn_sig(did).skip_binder().abi() == RustIntrinsic
                 && tcx.item_name(did) == sym::transmute
             {

compiler/rustc_hir_typeck/src/expr_use_visitor.rs

@@ -664,10 +664,12 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
         );
         self.walk_pat(discr_place, arm.pat, arm.guard.is_some());
 
-        if let Some(hir::Guard::If(e)) = arm.guard {
-            self.consume_expr(e)
-        } else if let Some(hir::Guard::IfLet(ref l)) = arm.guard {
-            self.consume_expr(l.init)
+        match arm.guard {
+            Some(hir::Guard::If(ref e)) => self.consume_expr(e),
+            Some(hir::Guard::IfLet(ref l)) => {
+                self.walk_local(l.init, l.pat, None, |t| t.borrow_expr(l.init, ty::ImmBorrow))
+            }
+            None => {}
         }
 
         self.consume_expr(arm.body);

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -518,8 +518,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.select_obligations_where_possible(|_| {});
 
         let mut generators = self.deferred_generator_interiors.borrow_mut();
-        for (_, body_id, interior, kind) in generators.drain(..) {
-            crate::generator_interior::resolve_interior(self, def_id, body_id, interior, kind);
+        for (generator_def_id, body_id, interior, kind) in generators.drain(..) {
+            crate::generator_interior::resolve_interior(
+                self,
+                def_id,
+                generator_def_id,
+                body_id,
+                interior,
+                kind,
+            );
             self.select_obligations_where_possible(|_| {});
         }
     }