Rollup of 7 pull requests

Cargo.lock

@@ -3595,6 +3595,7 @@ dependencies = [
  "rustc_index",
  "rustc_infer",
  "rustc_lexer",
+ "rustc_macros",
  "rustc_middle",
  "rustc_mir_dataflow",
  "rustc_serialize",

compiler/rustc_borrowck/Cargo.toml

@@ -19,6 +19,7 @@ rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
 rustc_infer = { path = "../rustc_infer" }
 rustc_lexer = { path = "../rustc_lexer" }
+rustc_macros = { path = "../rustc_macros" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_const_eval = { path = "../rustc_const_eval" }
 rustc_mir_dataflow = { path = "../rustc_mir_dataflow" }

compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs

@@ -19,6 +19,9 @@ use std::fmt;
 use std::rc::Rc;
 
 use crate::region_infer::values::RegionElement;
+use crate::session_diagnostics::HigherRankedErrorCause;
+use crate::session_diagnostics::HigherRankedLifetimeError;
+use crate::session_diagnostics::HigherRankedSubtypeError;
 use crate::MirBorrowckCtxt;
 
 #[derive(Clone)]
@@ -69,7 +72,7 @@ impl<'tcx> UniverseInfo<'tcx> {
                 // up in the existing UI tests. Consider investigating this
                 // some more.
                 mbcx.buffer_error(
-                    mbcx.infcx.tcx.sess.struct_span_err(cause.span, "higher-ranked subtype error"),
+                    mbcx.infcx.tcx.sess.create_err(HigherRankedSubtypeError { span: cause.span }),
                 );
             }
         }
@@ -216,9 +219,12 @@ impl<'tcx> TypeOpInfo<'tcx> for PredicateQuery<'tcx> {
         tcx: TyCtxt<'tcx>,
         span: Span,
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
-        let mut err = tcx.sess.struct_span_err(span, "higher-ranked lifetime error");
-        err.note(&format!("could not prove {}", self.canonical_query.value.value.predicate));
-        err
+        tcx.sess.create_err(HigherRankedLifetimeError {
+            cause: Some(HigherRankedErrorCause::CouldNotProve {
+                predicate: self.canonical_query.value.value.predicate.to_string(),
+            }),
+            span,
+        })
     }
 
     fn base_universe(&self) -> ty::UniverseIndex {
@@ -263,9 +269,12 @@ where
         tcx: TyCtxt<'tcx>,
         span: Span,
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
-        let mut err = tcx.sess.struct_span_err(span, "higher-ranked lifetime error");
-        err.note(&format!("could not normalize `{}`", self.canonical_query.value.value.value));
-        err
+        tcx.sess.create_err(HigherRankedLifetimeError {
+            cause: Some(HigherRankedErrorCause::CouldNotNormalize {
+                value: self.canonical_query.value.value.value.to_string(),
+            }),
+            span,
+        })
     }
 
     fn base_universe(&self) -> ty::UniverseIndex {
@@ -326,7 +335,7 @@ impl<'tcx> TypeOpInfo<'tcx> for AscribeUserTypeQuery<'tcx> {
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
         // FIXME: This error message isn't great, but it doesn't show up in the existing UI tests,
         // and is only the fallback when the nice error fails. Consider improving this some more.
-        tcx.sess.struct_span_err(span, "higher-ranked lifetime error")
+        tcx.sess.create_err(HigherRankedLifetimeError { cause: None, span })
     }
 
     fn base_universe(&self) -> ty::UniverseIndex {
@@ -366,7 +375,7 @@ impl<'tcx> TypeOpInfo<'tcx> for crate::type_check::InstantiateOpaqueType<'tcx> {
     ) -> DiagnosticBuilder<'tcx, ErrorGuaranteed> {
         // FIXME: This error message isn't great, but it doesn't show up in the existing UI tests,
         // and is only the fallback when the nice error fails. Consider improving this some more.
-        tcx.sess.struct_span_err(span, "higher-ranked lifetime error for opaque type!")
+        tcx.sess.create_err(HigherRankedLifetimeError { cause: None, span })
     }
 
     fn base_universe(&self) -> ty::UniverseIndex {

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -24,6 +24,7 @@ use rustc_span::symbol::Ident;
 use rustc_span::Span;
 
 use crate::borrowck_errors;
+use crate::session_diagnostics::GenericDoesNotLiveLongEnough;
 
 use super::{OutlivesSuggestionBuilder, RegionName};
 use crate::region_infer::BlameConstraint;
@@ -196,9 +197,11 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                         // to report it; we could probably handle it by
                         // iterating over the universal regions and reporting
                         // an error that multiple bounds are required.
-                        self.buffer_error(self.infcx.tcx.sess.struct_span_err(
-                            type_test_span,
-                            &format!("`{}` does not live long enough", type_test.generic_kind),
+                        self.buffer_error(self.infcx.tcx.sess.create_err(
+                            GenericDoesNotLiveLongEnough {
+                                kind: type_test.generic_kind.to_string(),
+                                span: type_test_span,
+                            },
                         ));
                     }
                 }

compiler/rustc_borrowck/src/lib.rs

@@ -76,6 +76,7 @@ mod places_conflict;
 mod prefixes;
 mod region_infer;
 mod renumber;
+mod session_diagnostics;
 mod type_check;
 mod universal_regions;
 mod used_muts;

compiler/rustc_borrowck/src/session_diagnostics.rs

@@ -0,0 +1,44 @@
+use rustc_macros::{SessionDiagnostic, SessionSubdiagnostic};
+use rustc_middle::ty::Ty;
+use rustc_span::Span;
+
+#[derive(SessionDiagnostic)]
+#[error(borrowck::move_unsized, code = "E0161")]
+pub(crate) struct MoveUnsized<'tcx> {
+    pub ty: Ty<'tcx>,
+    #[primary_span]
+    #[label]
+    pub span: Span,
+}
+
+#[derive(SessionDiagnostic)]
+#[error(borrowck::higher_ranked_lifetime_error)]
+pub(crate) struct HigherRankedLifetimeError {
+    #[subdiagnostic]
+    pub cause: Option<HigherRankedErrorCause>,
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(SessionSubdiagnostic)]
+pub(crate) enum HigherRankedErrorCause {
+    #[note(borrowck::could_not_prove)]
+    CouldNotProve { predicate: String },
+    #[note(borrowck::could_not_normalize)]
+    CouldNotNormalize { value: String },
+}
+
+#[derive(SessionDiagnostic)]
+#[error(borrowck::higher_ranked_subtype_error)]
+pub(crate) struct HigherRankedSubtypeError {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(SessionDiagnostic)]
+#[error(borrowck::generic_does_not_live_long_enough)]
+pub(crate) struct GenericDoesNotLiveLongEnough {
+    pub kind: String,
+    #[primary_span]
+    pub span: Span,
+}

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -9,7 +9,6 @@ use hir::OpaqueTyOrigin;
 use rustc_data_structures::frozen::Frozen;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::vec_map::VecMap;
-use rustc_errors::struct_span_err;
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
@@ -48,6 +47,7 @@ use rustc_mir_dataflow::impls::MaybeInitializedPlaces;
 use rustc_mir_dataflow::move_paths::MoveData;
 use rustc_mir_dataflow::ResultsCursor;
 
+use crate::session_diagnostics::MoveUnsized;
 use crate::{
     borrow_set::BorrowSet,
     constraints::{OutlivesConstraint, OutlivesConstraintSet},
@@ -1780,19 +1780,10 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             // slot or local, so to find all unsized rvalues it is enough
             // to check all temps, return slots and locals.
             if self.reported_errors.replace((ty, span)).is_none() {
-                let mut diag = struct_span_err!(
-                    self.tcx().sess,
-                    span,
-                    E0161,
-                    "cannot move a value of type {0}: the size of {0} \
-                     cannot be statically determined",
-                    ty
-                );
-
                 // While this is located in `nll::typeck` this error is not
                 // an NLL error, it's a required check to prevent creation
                 // of unsized rvalues in a call expression.
-                diag.emit();
+                self.tcx().sess.emit_err(MoveUnsized { ty, span });
             }
         }
     }

compiler/rustc_const_eval/src/interpret/cast.rs

@@ -366,22 +366,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             }
             (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {
                 assert_eq!(def_a, def_b);
-                if def_a.is_box() || def_b.is_box() {
-                    if !def_a.is_box() || !def_b.is_box() {
-                        span_bug!(
-                            self.cur_span(),
-                            "invalid unsizing between {:?} -> {:?}",
-                            src.layout.ty,
-                            cast_ty.ty
-                        );
-                    }
-                    return self.unsize_into_ptr(
-                        src,
-                        dest,
-                        src.layout.ty.boxed_ty(),
-                        cast_ty.ty.boxed_ty(),
-                    );
-                }
 
                 // unsizing of generic struct with pointer fields
                 // Example: `Arc<T>` -> `Arc<Trait>`

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -594,7 +594,13 @@ impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, '
                 Ok(true)
             }
             ty::Adt(def, ..) if def.is_box() => {
-                self.check_safe_pointer(value, "box")?;
+                let unique = self.ecx.operand_field(value, 0)?;
+                let nonnull = self.ecx.operand_field(&unique, 0)?;
+                let ptr = self.ecx.operand_field(&nonnull, 0)?;
+                self.check_safe_pointer(&ptr, "box")?;
+
+                // Check other fields of Box
+                self.walk_value(value)?;
                 Ok(true)
             }
             ty::FnPtr(_sig) => {

compiler/rustc_error_messages/locales/en-US/borrowck.ftl

@@ -0,0 +1,18 @@
+borrowck-move-unsized =
+    cannot move a value of type `{$ty}`
+    .label = the size of `{$ty}` cannot be statically determined
+
+borrowck-higher-ranked-lifetime-error =
+    higher-ranked lifetime error
+
+borrowck-could-not-prove =
+    could not prove `{$predicate}`
+
+borrowck-could-not-normalize =
+    could not normalize `{$value}`
+
+borrowck-higher-ranked-subtype-error =
+    higher-ranked subtype error
+
+generic-does-not-live-long-enough =
+    `{$kind}` does not live long enough

compiler/rustc_error_messages/src/lib.rs

@@ -35,6 +35,7 @@ fluent_messages! {
     privacy => "../locales/en-US/privacy.ftl",
     typeck => "../locales/en-US/typeck.ftl",
     builtin_macros => "../locales/en-US/builtin_macros.ftl",
+    borrowck => "../locales/en-US/borrowck.ftl",
 }
 
 pub use fluent_generated::{self as fluent, DEFAULT_LOCALE_RESOURCES};

compiler/rustc_errors/src/emitter.rs

@@ -281,9 +281,19 @@ pub trait Emitter {
         let message = bundle.get_message(&identifier).expect("missing diagnostic in fluent bundle");
         let value = match attr {
             Some(attr) => {
-                message.get_attribute(attr).expect("missing attribute in fluent message").value()
+                if let Some(attr) = message.get_attribute(attr) {
+                    attr.value()
+                } else {
+                    panic!("missing attribute `{attr}` in fluent message `{identifier}`")
+                }
+            }
+            None => {
+                if let Some(value) = message.value() {
+                    value
+                } else {
+                    panic!("missing value in fluent message `{identifier}`")
+                }
             }
-            None => message.value().expect("missing value in fluent message"),
         };
 
         let mut err = vec![];

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -342,8 +342,8 @@ pub fn same_type_modulo_infer<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
         )
         | (&ty::Infer(ty::InferTy::TyVar(_)), _)
         | (_, &ty::Infer(ty::InferTy::TyVar(_))) => true,
-        (&ty::Ref(reg_a, ty_a, mut_a), &ty::Ref(reg_b, ty_b, mut_b)) => {
-            reg_a == reg_b && mut_a == mut_b && same_type_modulo_infer(*ty_a, *ty_b)
+        (&ty::Ref(_, ty_a, mut_a), &ty::Ref(_, ty_b, mut_b)) => {
+            mut_a == mut_b && same_type_modulo_infer(*ty_a, *ty_b)
         }
         _ => a == b,
     }

compiler/rustc_mir_transform/src/add_retag.rs

@@ -33,8 +33,9 @@ fn is_stable(place: PlaceRef<'_>) -> bool {
     })
 }
 
-/// Determine whether this type may be a reference (or box), and thus needs retagging.
-fn may_be_reference(ty: Ty<'_>) -> bool {
+/// Determine whether this type may contain a reference (or box), and thus needs retagging.
+/// We will only recurse `depth` times into Tuples/ADTs to bound the cost of this.
+fn may_contain_reference<'tcx>(ty: Ty<'tcx>, depth: u32, tcx: TyCtxt<'tcx>) -> bool {
     match ty.kind() {
         // Primitive types that are not references
         ty::Bool
@@ -50,8 +51,20 @@ fn may_be_reference(ty: Ty<'_>) -> bool {
         // References
         ty::Ref(..) => true,
         ty::Adt(..) if ty.is_box() => true,
-        // Compound types are not references
-        ty::Array(..) | ty::Slice(..) | ty::Tuple(..) | ty::Adt(..) => false,
+        // Compound types: recurse
+        ty::Array(ty, _) | ty::Slice(ty) => {
+            // This does not branch so we keep the depth the same.
+            may_contain_reference(*ty, depth, tcx)
+        }
+        ty::Tuple(tys) => {
+            depth == 0 || tys.iter().any(|ty| may_contain_reference(ty, depth - 1, tcx))
+        }
+        ty::Adt(adt, subst) => {
+            depth == 0
+                || adt.variants().iter().any(|v| {
+                    v.fields.iter().any(|f| may_contain_reference(f.ty(tcx, subst), depth - 1, tcx))
+                })
+        }
         // Conservative fallback
         _ => true,
     }
@@ -83,7 +96,7 @@ impl<'tcx> MirPass<'tcx> for AddRetag {
             // FIXME: Instead of giving up for unstable places, we should introduce
             // a temporary and retag on that.
             is_stable(place.as_ref())
-                && may_be_reference(place.ty(&*local_decls, tcx).ty)
+                && may_contain_reference(place.ty(&*local_decls, tcx).ty, /*depth*/ 3, tcx)
                 && is_not_temp(&local_decls[place.local])
         };
         let place_base_raw = |place: &Place<'tcx>| {

compiler/rustc_trait_selection/src/traits/const_evaluatable.rs

@@ -236,7 +236,7 @@ impl<'tcx> AbstractConst<'tcx> {
     ) -> Result<Option<AbstractConst<'tcx>>, ErrorGuaranteed> {
         let inner = tcx.thir_abstract_const_opt_const_arg(uv.def)?;
         debug!("AbstractConst::new({:?}) = {:?}", uv, inner);
-        Ok(inner.map(|inner| AbstractConst { inner, substs: uv.substs }))
+        Ok(inner.map(|inner| AbstractConst { inner, substs: tcx.erase_regions(uv.substs) }))
     }
 
     pub fn from_const(
@@ -416,6 +416,7 @@ impl<'a, 'tcx> AbstractConstBuilder<'a, 'tcx> {
                     // `AbstractConst`s should not contain any promoteds as they require references which
                     // are not allowed.
                     assert_eq!(ct.promoted, None);
+                    assert_eq!(ct, self.tcx.erase_regions(ct));
                 }
             }
         }