Rollup of 6 pull requests

compiler/rustc_ast/src/attr/mod.rs

@@ -230,7 +230,7 @@ impl AttrItem {
     }
 
     pub fn meta_kind(&self) -> Option<MetaItemKind> {
-        Some(MetaItemKind::from_mac_args(&self.args)?)
+        MetaItemKind::from_mac_args(&self.args)
     }
 }
 

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -823,7 +823,7 @@ fn maybe_stage_features(sess: &Session, krate: &ast::Crate) {
             );
             let mut all_stable = true;
             for ident in
-                attr.meta_item_list().into_iter().flatten().map(|nested| nested.ident()).flatten()
+                attr.meta_item_list().into_iter().flatten().flat_map(|nested| nested.ident())
             {
                 let name = ident.name;
                 let stable_since = lang_features

compiler/rustc_builtin_macros/src/proc_macro_harness.rs

@@ -56,7 +56,6 @@ pub fn inject(
     is_proc_macro_crate: bool,
     has_proc_macro_decls: bool,
     is_test_crate: bool,
-    num_crate_types: usize,
     handler: &rustc_errors::Handler,
 ) -> ast::Crate {
     let ecfg = ExpansionConfig::default("proc_macro".to_string());
@@ -81,10 +80,6 @@ pub fn inject(
         return krate;
     }
 
-    if num_crate_types > 1 {
-        handler.err("cannot mix `proc-macro` crate type with others");
-    }
-
     if is_test_crate {
         return krate;
     }

compiler/rustc_builtin_macros/src/test.rs

@@ -6,6 +6,7 @@ use rustc_ast as ast;
 use rustc_ast::attr;
 use rustc_ast::ptr::P;
 use rustc_ast_pretty::pprust;
+use rustc_errors::Applicability;
 use rustc_expand::base::*;
 use rustc_session::Session;
 use rustc_span::symbol::{sym, Ident, Symbol};
@@ -102,11 +103,20 @@ pub fn expand_test_or_bench(
         }
     };
 
-    if let ast::ItemKind::MacCall(_) = item.kind {
-        cx.sess.parse_sess.span_diagnostic.span_warn(
-            item.span,
-            "`#[test]` attribute should not be used on macros. Use `#[cfg(test)]` instead.",
-        );
+    // Note: non-associated fn items are already handled by `expand_test_or_bench`
+    if !matches!(item.kind, ast::ItemKind::Fn(_)) {
+        cx.sess
+            .parse_sess
+            .span_diagnostic
+            .struct_span_err(
+                attr_sp,
+                "the `#[test]` attribute may only be used on a non-associated function",
+            )
+            .note("the `#[test]` macro causes a a function to be run on a test and has no effect on non-functions")
+            .span_label(item.span, format!("expected a non-associated function, found {} {}", item.kind.article(), item.kind.descr()))
+            .span_suggestion(attr_sp, "replace with conditional compilation to make the item only exist when tests are being run", String::from("#[cfg(test)]"), Applicability::MaybeIncorrect)
+            .emit();
+
         return vec![Annotatable::Item(item)];
     }
 
@@ -466,7 +476,7 @@ fn has_test_signature(cx: &ExtCtxt<'_>, i: &ast::Item) -> bool {
             (false, _) => true,
         }
     } else {
-        sd.span_err(i.span, "only functions may be used as tests");
+        // should be unreachable because `is_test_fn_item` should catch all non-fn items
         false
     }
 }

compiler/rustc_codegen_llvm/src/context.rs

@@ -292,7 +292,7 @@ pub unsafe fn create_module<'ll>(
             "sign-return-address-all\0".as_ptr().cast(),
             pac_opts.leaf.into(),
         );
-        let is_bkey = if pac_opts.key == PAuthKey::A { false } else { true };
+        let is_bkey: bool = pac_opts.key != PAuthKey::A;
         llvm::LLVMRustAddModuleFlag(
             llmod,
             llvm::LLVMModFlagBehavior::Error,

compiler/rustc_codegen_ssa/src/mir/place.rs

@@ -476,7 +476,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 mir::ProjectionElem::Subslice { from, to, from_end } => {
                     let mut subslice = cg_base.project_index(bx, bx.cx().const_usize(from as u64));
                     let projected_ty =
-                        PlaceTy::from_ty(cg_base.layout.ty).projection_ty(tcx, elem.clone()).ty;
+                        PlaceTy::from_ty(cg_base.layout.ty).projection_ty(tcx, *elem).ty;
                     subslice.layout = bx.cx().layout_of(self.monomorphize(projected_ty));
 
                     if subslice.layout.is_unsized() {

compiler/rustc_expand/src/mbe/macro_rules.rs

@@ -1039,7 +1039,7 @@ fn check_matcher_core(
                                 ));
                                 err.span_suggestion(
                                     span,
-                                    &format!("try a `pat_param` fragment specifier instead"),
+                                    "try a `pat_param` fragment specifier instead",
                                     suggestion,
                                     Applicability::MaybeIncorrect,
                                 );

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

@@ -64,7 +64,7 @@ impl<'cx, 'tcx> NiceRegionError<'cx, 'tcx> {
             .or_else(|| self.try_report_mismatched_static_lifetime())
     }
 
-    pub fn regions(&self) -> Option<(Span, ty::Region<'tcx>, ty::Region<'tcx>)> {
+    pub(super) fn regions(&self) -> Option<(Span, ty::Region<'tcx>, ty::Region<'tcx>)> {
         match (&self.error, self.regions) {
             (Some(ConcreteFailure(origin, sub, sup)), None) => Some((origin.span(), *sub, *sup)),
             (Some(SubSupConflict(_, _, origin, sub, _, sup, _)), None) => {

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

@@ -102,6 +102,9 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     "...so that the definition in impl matches the definition from the trait",
                 );
             }
+            infer::CheckAssociatedTypeBounds { ref parent, .. } => {
+                self.note_region_origin(err, &parent);
+            }
         }
     }
 
@@ -345,6 +348,55 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                     trait_item_def_id,
                     &format!("`{}: {}`", sup, sub),
                 ),
+            infer::CheckAssociatedTypeBounds { impl_item_def_id, trait_item_def_id, parent } => {
+                let mut err = self.report_concrete_failure(*parent, sub, sup);
+
+                let trait_item_span = self.tcx.def_span(trait_item_def_id);
+                let item_name = self.tcx.item_name(impl_item_def_id);
+                err.span_label(
+                    trait_item_span,
+                    format!("definition of `{}` from trait", item_name),
+                );
+
+                let trait_predicates = self.tcx.explicit_predicates_of(trait_item_def_id);
+                let impl_predicates = self.tcx.explicit_predicates_of(impl_item_def_id);
+
+                let impl_predicates: rustc_data_structures::stable_set::FxHashSet<_> =
+                    impl_predicates.predicates.into_iter().map(|(pred, _)| pred).collect();
+                let clauses: Vec<_> = trait_predicates
+                    .predicates
+                    .into_iter()
+                    .filter(|&(pred, _)| !impl_predicates.contains(pred))
+                    .map(|(pred, _)| format!("{}", pred))
+                    .collect();
+
+                if !clauses.is_empty() {
+                    let where_clause_span = self
+                        .tcx
+                        .hir()
+                        .get_generics(impl_item_def_id.expect_local())
+                        .unwrap()
+                        .where_clause
+                        .tail_span_for_suggestion();
+
+                    let suggestion = format!(
+                        "{} {}",
+                        if !impl_predicates.is_empty() { "," } else { " where" },
+                        clauses.join(", "),
+                    );
+                    err.span_suggestion(
+                        where_clause_span,
+                        &format!(
+                            "try copying {} from the trait",
+                            if clauses.len() > 1 { "these clauses" } else { "this clause" }
+                        ),
+                        suggestion,
+                        rustc_errors::Applicability::MaybeIncorrect,
+                    );
+                }
+
+                err
+            }
         }
     }
 

compiler/rustc_infer/src/infer/mod.rs

@@ -438,6 +438,13 @@ pub enum SubregionOrigin<'tcx> {
     /// Comparing the signature and requirements of an impl associated type
     /// against the containing trait
     CompareImplTypeObligation { span: Span, impl_item_def_id: DefId, trait_item_def_id: DefId },
+
+    /// Checking that the bounds of a trait's associated type hold for a given impl
+    CheckAssociatedTypeBounds {
+        parent: Box<SubregionOrigin<'tcx>>,
+        impl_item_def_id: DefId,
+        trait_item_def_id: DefId,
+    },
 }
 
 // `SubregionOrigin` is used a lot. Make sure it doesn't unintentionally get bigger.
@@ -1832,6 +1839,7 @@ impl<'tcx> SubregionOrigin<'tcx> {
             ReferenceOutlivesReferent(_, a) => a,
             CompareImplMethodObligation { span, .. } => span,
             CompareImplTypeObligation { span, .. } => span,
+            CheckAssociatedTypeBounds { ref parent, .. } => parent.span(),
         }
     }
 
@@ -1862,6 +1870,15 @@ impl<'tcx> SubregionOrigin<'tcx> {
                 trait_item_def_id,
             },
 
+            traits::ObligationCauseCode::CheckAssociatedTypeBounds {
+                impl_item_def_id,
+                trait_item_def_id,
+            } => SubregionOrigin::CheckAssociatedTypeBounds {
+                impl_item_def_id,
+                trait_item_def_id,
+                parent: Box::new(default()),
+            },
+
             _ => default(),
         }
     }

compiler/rustc_interface/src/passes.rs

@@ -393,8 +393,18 @@ pub fn configure_and_expand(
     });
 
     let crate_types = sess.crate_types();
+    let is_executable_crate = crate_types.contains(&CrateType::Executable);
     let is_proc_macro_crate = crate_types.contains(&CrateType::ProcMacro);
 
+    if crate_types.len() > 1 {
+        if is_executable_crate {
+            sess.err("cannot mix `bin` crate type with others");
+        }
+        if is_proc_macro_crate {
+            sess.err("cannot mix `proc-macro` crate type with others");
+        }
+    }
+
     // For backwards compatibility, we don't try to run proc macro injection
     // if rustdoc is run on a proc macro crate without '--crate-type proc-macro' being
     // specified. This should only affect users who manually invoke 'rustdoc', as
@@ -411,7 +421,6 @@ pub fn configure_and_expand(
         msg.emit()
     } else {
         krate = sess.time("maybe_create_a_macro_crate", || {
-            let num_crate_types = crate_types.len();
             let is_test_crate = sess.opts.test;
             rustc_builtin_macros::proc_macro_harness::inject(
                 sess,
@@ -420,7 +429,6 @@ pub fn configure_and_expand(
                 is_proc_macro_crate,
                 has_proc_macro_decls,
                 is_test_crate,
-                num_crate_types,
                 sess.diagnostic(),
             )
         });

compiler/rustc_middle/src/middle/stability.rs

@@ -198,7 +198,7 @@ fn deprecation_message(
     } else {
         let since = since.as_ref().map(Symbol::as_str);
 
-        if since.as_deref() == Some("TBD") {
+        if since == Some("TBD") {
             format!("use of {} `{}` that will be deprecated in a future Rust version", kind, path)
         } else {
             format!(

compiler/rustc_middle/src/traits/mod.rs

@@ -285,6 +285,12 @@ pub enum ObligationCauseCode<'tcx> {
         trait_item_def_id: DefId,
     },
 
+    /// Checking that the bounds of a trait's associated type hold for a given impl
+    CheckAssociatedTypeBounds {
+        impl_item_def_id: DefId,
+        trait_item_def_id: DefId,
+    },
+
     /// Checking that this expression can be assigned where it needs to be
     // FIXME(eddyb) #11161 is the original Expr required?
     ExprAssignable,

compiler/rustc_middle/src/ty/relate.rs

@@ -855,7 +855,7 @@ impl<'tcx> Relate<'tcx> for ty::ProjectionPredicate<'tcx> {
     ) -> RelateResult<'tcx, ty::ProjectionPredicate<'tcx>> {
         Ok(ty::ProjectionPredicate {
             projection_ty: relation.relate(a.projection_ty, b.projection_ty)?,
-            term: relation.relate(a.term, b.term)?.into(),
+            term: relation.relate(a.term, b.term)?,
         })
     }
 }

compiler/rustc_middle/src/ty/trait_def.rs

@@ -210,7 +210,7 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn all_impls(self, def_id: DefId) -> impl Iterator<Item = DefId> + 'tcx {
         let TraitImpls { blanket_impls, non_blanket_impls } = self.trait_impls_of(def_id);
 
-        blanket_impls.iter().chain(non_blanket_impls.iter().map(|(_, v)| v).flatten()).cloned()
+        blanket_impls.iter().chain(non_blanket_impls.iter().flat_map(|(_, v)| v)).cloned()
     }
 }
 

compiler/rustc_mir_transform/src/coverage/query.rs

@@ -140,7 +140,7 @@ fn covered_code_regions<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Vec<&'tcx Cod
     let body = mir_body(tcx, def_id);
     body.basic_blocks()
         .iter()
-        .map(|data| {
+        .flat_map(|data| {
             data.statements.iter().filter_map(|statement| match statement.kind {
                 StatementKind::Coverage(box ref coverage) => {
                     if is_inlined(body, statement) {
@@ -152,7 +152,6 @@ fn covered_code_regions<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Vec<&'tcx Cod
                 _ => None,
             })
         })
-        .flatten()
         .collect()
 }
 

compiler/rustc_mir_transform/src/inline.rs

@@ -7,6 +7,7 @@ use rustc_index::vec::Idx;
 use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs};
 use rustc_middle::mir::visit::*;
 use rustc_middle::mir::*;
+use rustc_middle::traits::ObligationCause;
 use rustc_middle::ty::subst::Subst;
 use rustc_middle::ty::{self, ConstKind, Instance, InstanceDef, ParamEnv, Ty, TyCtxt};
 use rustc_span::{hygiene::ExpnKind, ExpnData, Span};
@@ -75,10 +76,18 @@ fn inline<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) -> bool {
         return false;
     }
 
+    let param_env = tcx.param_env_reveal_all_normalized(def_id);
+    let param_env = rustc_trait_selection::traits::normalize_param_env_or_error(
+        tcx,
+        def_id,
+        param_env,
+        ObligationCause::misc(body.span, hir_id),
+    );
+
     let mut this = Inliner {
         tcx,
-        param_env: tcx.param_env_reveal_all_normalized(body.source.def_id()),
-        codegen_fn_attrs: tcx.codegen_fn_attrs(body.source.def_id()),
+        param_env,
+        codegen_fn_attrs: tcx.codegen_fn_attrs(def_id),
         hir_id,
         history: Vec::new(),
         changed: false,

compiler/rustc_monomorphize/src/partitioning/mod.rs

@@ -220,18 +220,16 @@ pub fn partition<'tcx>(
         let mut cgus: Vec<_> = post_inlining.codegen_units.iter_mut().collect();
         cgus.sort_by_key(|cgu| cgu.size_estimate());
 
-        let dead_code_cgu = if let Some(cgu) = cgus
-            .into_iter()
-            .rev()
-            .filter(|cgu| cgu.items().iter().any(|(_, (linkage, _))| *linkage == Linkage::External))
-            .next()
-        {
-            cgu
-        } else {
-            // If there are no CGUs that have externally linked items,
-            // then we just pick the first CGU as a fallback.
-            &mut post_inlining.codegen_units[0]
-        };
+        let dead_code_cgu =
+            if let Some(cgu) = cgus.into_iter().rev().find(|cgu| {
+                cgu.items().iter().any(|(_, (linkage, _))| *linkage == Linkage::External)
+            }) {
+                cgu
+            } else {
+                // If there are no CGUs that have externally linked items,
+                // then we just pick the first CGU as a fallback.
+                &mut post_inlining.codegen_units[0]
+            };
         dead_code_cgu.make_code_coverage_dead_code_cgu();
     }
 

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -2156,7 +2156,7 @@ impl<'a> Parser<'a> {
                             | PatKind::TupleStruct(qself @ None, path, _)
                             | PatKind::Path(qself @ None, path) => match &first_pat.kind {
                                 PatKind::Ident(_, ident, _) => {
-                                    path.segments.insert(0, PathSegment::from_ident(ident.clone()));
+                                    path.segments.insert(0, PathSegment::from_ident(*ident));
                                     path.span = new_span;
                                     show_sugg = true;
                                     first_pat = pat;
@@ -2183,8 +2183,8 @@ impl<'a> Parser<'a> {
                                             Path {
                                                 span: new_span,
                                                 segments: vec![
-                                                    PathSegment::from_ident(old_ident.clone()),
-                                                    PathSegment::from_ident(ident.clone()),
+                                                    PathSegment::from_ident(*old_ident),
+                                                    PathSegment::from_ident(*ident),
                                                 ],
                                                 tokens: None,
                                             },
@@ -2194,7 +2194,7 @@ impl<'a> Parser<'a> {
                                     }
                                     PatKind::Path(old_qself, old_path) => {
                                         let mut segments = old_path.segments.clone();
-                                        segments.push(PathSegment::from_ident(ident.clone()));
+                                        segments.push(PathSegment::from_ident(*ident));
                                         let path = PatKind::Path(
                                             old_qself.clone(),
                                             Path { span: new_span, segments, tokens: None },