Merge from rustc

Author: saethlin

compiler/rustc_abi/src/lib.rs

@@ -1,7 +1,7 @@
 #![cfg_attr(feature = "nightly", feature(step_trait))]
 #![cfg_attr(feature = "nightly", allow(internal_features))]
-#![cfg_attr(all(not(bootstrap), feature = "nightly"), doc(rust_logo))]
-#![cfg_attr(all(not(bootstrap), feature = "nightly"), feature(rustdoc_internals))]
+#![cfg_attr(feature = "nightly", doc(rust_logo))]
+#![cfg_attr(feature = "nightly", feature(rustdoc_internals))]
 
 use std::fmt;
 use std::num::{NonZeroUsize, ParseIntError};

compiler/rustc_arena/src/lib.rs

@@ -11,8 +11,8 @@
     html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",
     test(no_crate_inject, attr(deny(warnings)))
 )]
-#![cfg_attr(not(bootstrap), doc(rust_logo))]
-#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
+#![doc(rust_logo)]
+#![feature(rustdoc_internals)]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(new_uninit)]

compiler/rustc_ast/src/lib.rs

@@ -8,9 +8,9 @@
     html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/",
     test(attr(deny(warnings)))
 )]
-#![cfg_attr(not(bootstrap), doc(rust_logo))]
-#![cfg_attr(not(bootstrap), allow(internal_features))]
-#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
+#![doc(rust_logo)]
+#![allow(internal_features)]
+#![feature(rustdoc_internals)]
 #![feature(associated_type_bounds)]
 #![feature(box_patterns)]
 #![feature(const_trait_impl)]

compiler/rustc_ast_lowering/src/lib.rs

@@ -30,9 +30,9 @@
 //! get confused if the spans from leaf AST nodes occur in multiple places
 //! in the HIR, especially for multiple identifiers.
 
-#![cfg_attr(not(bootstrap), allow(internal_features))]
-#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
-#![cfg_attr(not(bootstrap), doc(rust_logo))]
+#![allow(internal_features)]
+#![feature(rustdoc_internals)]
+#![doc(rust_logo)]
 #![feature(box_patterns)]
 #![feature(let_chains)]
 #![feature(never_type)]

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -1213,8 +1213,12 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                         DisallowTildeConstContext::Fn(FnKind::Fn(_, ident, ..)) => {
                             errors::TildeConstReason::Function { ident: ident.span }
                         }
-                        &DisallowTildeConstContext::Trait(span) => errors::TildeConstReason::Trait { span },
-                        &DisallowTildeConstContext::Impl(span) => errors::TildeConstReason::Impl { span },
+                        &DisallowTildeConstContext::Trait(span) => {
+                            errors::TildeConstReason::Trait { span }
+                        }
+                        &DisallowTildeConstContext::Impl(span) => {
+                            errors::TildeConstReason::Impl { span }
+                        }
                         DisallowTildeConstContext::TraitObject => {
                             errors::TildeConstReason::TraitObject
                         }
@@ -1446,9 +1450,7 @@ fn deny_equality_constraints(
                     id: rustc_ast::node_id::DUMMY_NODE_ID,
                     ident: *ident,
                     gen_args,
-                    kind: AssocConstraintKind::Equality {
-                        term: predicate.rhs_ty.clone().into(),
-                    },
+                    kind: AssocConstraintKind::Equality { term: predicate.rhs_ty.clone().into() },
                     span: ident.span,
                 });
                 // Add `<Bar = RhsTy>` to `Foo`.
@@ -1461,11 +1463,7 @@ fn deny_equality_constraints(
                     },
                     empty_args => {
                         *empty_args = Some(
-                            AngleBracketedArgs {
-                                span: ident.span,
-                                args: thin_vec![arg],
-                            }
-                            .into(),
+                            AngleBracketedArgs { span: ident.span, args: thin_vec![arg] }.into(),
                         );
                     }
                 }

compiler/rustc_ast_passes/src/lib.rs

@@ -4,9 +4,9 @@
 //!
 //! The crate also contains other misc AST visitors, e.g. `node_count` and `show_span`.
 
-#![cfg_attr(not(bootstrap), allow(internal_features))]
-#![cfg_attr(not(bootstrap), doc(rust_logo))]
-#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
+#![allow(internal_features)]
+#![doc(rust_logo)]
+#![feature(rustdoc_internals)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(iter_is_partitioned)]

compiler/rustc_ast_pretty/src/lib.rs

@@ -1,6 +1,6 @@
-#![cfg_attr(not(bootstrap), allow(internal_features))]
-#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
-#![cfg_attr(not(bootstrap), doc(rust_logo))]
+#![allow(internal_features)]
+#![feature(rustdoc_internals)]
+#![doc(rust_logo)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]
 #![feature(associated_type_bounds)]

compiler/rustc_attr/src/lib.rs

@@ -4,9 +4,9 @@
 //! The goal is to move the definition of `MetaItem` and things that don't need to be in `syntax`
 //! to this crate.
 
-#![cfg_attr(not(bootstrap), allow(internal_features))]
-#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
-#![cfg_attr(not(bootstrap), doc(rust_logo))]
+#![allow(internal_features)]
+#![feature(rustdoc_internals)]
+#![doc(rust_logo)]
 #![feature(let_chains)]
 #![deny(rustc::untranslatable_diagnostic)]
 #![deny(rustc::diagnostic_outside_of_impl)]

compiler/rustc_baked_icu_data/src/lib.rs

@@ -20,9 +20,9 @@
 //! --cldr-tag latest --icuexport-tag latest -o src/data
 //! ```
 
-#![cfg_attr(not(bootstrap), allow(internal_features))]
-#![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
-#![cfg_attr(not(bootstrap), doc(rust_logo))]
+#![allow(internal_features)]
+#![feature(rustdoc_internals)]
+#![doc(rust_logo)]
 #![allow(elided_lifetimes_in_paths)]
 
 mod data {

compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs

@@ -10,6 +10,8 @@ use rustc_infer::infer::RegionVariableOrigin;
 use rustc_infer::infer::{InferCtxt, RegionResolutionError, SubregionOrigin, TyCtxtInferExt as _};
 use rustc_infer::traits::ObligationCause;
 use rustc_middle::ty::error::TypeError;
+use rustc_middle::ty::RePlaceholder;
+use rustc_middle::ty::Region;
 use rustc_middle::ty::RegionVid;
 use rustc_middle::ty::UniverseIndex;
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
@@ -205,6 +207,8 @@ trait TypeOpInfo<'tcx> {
         let span = cause.span;
         let nice_error = self.nice_error(mbcx, cause, placeholder_region, error_region);
 
+        debug!(?nice_error);
+
         if let Some(nice_error) = nice_error {
             mbcx.buffer_error(nice_error);
         } else {
@@ -404,19 +408,41 @@ fn try_extract_error_from_region_constraints<'tcx>(
     mut region_var_origin: impl FnMut(RegionVid) -> RegionVariableOrigin,
     mut universe_of_region: impl FnMut(RegionVid) -> UniverseIndex,
 ) -> Option<DiagnosticBuilder<'tcx, ErrorGuaranteed>> {
-    let (sub_region, cause) =
-        region_constraints.constraints.iter().find_map(|(constraint, cause)| {
-            match *constraint {
-                Constraint::RegSubReg(sub, sup) if sup == placeholder_region && sup != sub => {
-                    Some((sub, cause.clone()))
-                }
-                // FIXME: Should this check the universe of the var?
-                Constraint::VarSubReg(vid, sup) if sup == placeholder_region => {
-                    Some((ty::Region::new_var(infcx.tcx, vid), cause.clone()))
-                }
-                _ => None,
+    let matches =
+        |a_region: Region<'tcx>, b_region: Region<'tcx>| match (a_region.kind(), b_region.kind()) {
+            (RePlaceholder(a_p), RePlaceholder(b_p)) => a_p.bound == b_p.bound,
+            _ => a_region == b_region,
+        };
+    let check = |constraint: &Constraint<'tcx>, cause: &SubregionOrigin<'tcx>, exact| {
+        match *constraint {
+            Constraint::RegSubReg(sub, sup)
+                if ((exact && sup == placeholder_region)
+                    || (!exact && matches(sup, placeholder_region)))
+                    && sup != sub =>
+            {
+                Some((sub, cause.clone()))
+            }
+            // FIXME: Should this check the universe of the var?
+            Constraint::VarSubReg(vid, sup)
+                if ((exact && sup == placeholder_region)
+                    || (!exact && matches(sup, placeholder_region))) =>
+            {
+                Some((ty::Region::new_var(infcx.tcx, vid), cause.clone()))
             }
-        })?;
+            _ => None,
+        }
+    };
+    let mut info = region_constraints
+        .constraints
+        .iter()
+        .find_map(|(constraint, cause)| check(constraint, cause, true));
+    if info.is_none() {
+        info = region_constraints
+            .constraints
+            .iter()
+            .find_map(|(constraint, cause)| check(constraint, cause, false));
+    }
+    let (sub_region, cause) = info?;
 
     debug!(?sub_region, "cause = {:#?}", cause);
     let error = match (error_region, *sub_region) {