Auto merge of rust-lang#93173 - matthiaskrgr:rollup-49bj7ta, r=matthiaskrgr

Rollup of 10 pull requests

Successful merges:

 - rust-lang#91965 (Add more granular `--exclude` in `x.py`)
 - rust-lang#92467 (Ensure that early-bound function lifetimes are always 'local')
 - rust-lang#92586 (Set the allocation MIN_ALIGN for espidf to 4.)
 - rust-lang#92835 (Improve error message for key="value" cfg arguments.)
 - rust-lang#92843 (Improve string concatenation suggestion)
 - rust-lang#92963 (Implement tuple array diagnostic)
 - rust-lang#93046 (Use let_else in even more places)
 - rust-lang#93109 (Improve `Arc` and `Rc` documentation)
 - rust-lang#93134 (delete `Stdin::split` forwarder)
 - rust-lang#93139 (rustdoc: fix overflow-wrap for table layouts)

Failed merges:

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

Author: bors

compiler/rustc_borrowck/src/universal_regions.rs

@@ -180,8 +180,9 @@ pub enum RegionClassification {
     /// anywhere. There is only one, `'static`.
     Global,
 
-    /// An **external** region is only relevant for closures. In that
-    /// case, it refers to regions that are free in the closure type
+    /// An **external** region is only relevant for
+    /// closures, generators, and inline consts. In that
+    /// case, it refers to regions that are free in the type
     /// -- basically, something bound in the surrounding context.
     ///
     /// Consider this example:
@@ -198,8 +199,8 @@ pub enum RegionClassification {
     /// Here, the lifetimes `'a` and `'b` would be **external** to the
     /// closure.
     ///
-    /// If we are not analyzing a closure, there are no external
-    /// lifetimes.
+    /// If we are not analyzing a closure/generator/inline-const,
+    /// there are no external lifetimes.
     External,
 
     /// A **local** lifetime is one about which we know the full set
@@ -424,22 +425,30 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
 
         let typeck_root_def_id = self.infcx.tcx.typeck_root_def_id(self.mir_def.did.to_def_id());
 
-        // If this is a closure or generator, then the late-bound regions from the enclosing
-        // function are actually external regions to us. For example, here, 'a is not local
-        // to the closure c (although it is local to the fn foo):
-        // fn foo<'a>() {
-        //     let c = || { let x: &'a u32 = ...; }
-        // }
-        if self.mir_def.did.to_def_id() != typeck_root_def_id {
+        // If this is is a 'root' body (not a closure/generator/inline const), then
+        // there are no extern regions, so the local regions start at the same
+        // position as the (empty) sub-list of extern regions
+        let first_local_index = if self.mir_def.did.to_def_id() == typeck_root_def_id {
+            first_extern_index
+        } else {
+            // If this is a closure, generator, or inline-const, then the late-bound regions from the enclosing
+            // function are actually external regions to us. For example, here, 'a is not local
+            // to the closure c (although it is local to the fn foo):
+            // fn foo<'a>() {
+            //     let c = || { let x: &'a u32 = ...; }
+            // }
             self.infcx
-                .replace_late_bound_regions_with_nll_infer_vars(self.mir_def.did, &mut indices)
-        }
-
-        let bound_inputs_and_output = self.compute_inputs_and_output(&indices, defining_ty);
+                .replace_late_bound_regions_with_nll_infer_vars(self.mir_def.did, &mut indices);
+            // Any regions created during the execution of `defining_ty` or during the above
+            // late-bound region replacement are all considered 'extern' regions
+            self.infcx.num_region_vars()
+        };
 
         // "Liberate" the late-bound regions. These correspond to
         // "local" free regions.
-        let first_local_index = self.infcx.num_region_vars();
+
+        let bound_inputs_and_output = self.compute_inputs_and_output(&indices, defining_ty);
+
         let inputs_and_output = self.infcx.replace_bound_regions_with_nll_infer_vars(
             FR,
             self.mir_def.did,

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -1493,7 +1493,7 @@ fn generator_layout_and_saved_local_names<'tcx>(
 
     let state_arg = mir::Local::new(1);
     for var in &body.var_debug_info {
-        let place = if let mir::VarDebugInfoContents::Place(p) = var.value { p } else { continue };
+        let mir::VarDebugInfoContents::Place(place) = &var.value else { continue };
         if place.local != state_arg {
             continue;
         }

compiler/rustc_codegen_llvm/src/lib.rs

@@ -7,6 +7,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(bool_to_option)]
 #![feature(crate_visibility_modifier)]
+#![feature(let_else)]
 #![feature(extern_types)]
 #![feature(nll)]
 #![recursion_limit = "256"]

compiler/rustc_interface/src/interface.rs

@@ -124,7 +124,16 @@ pub fn parse_cfgspecs(cfgspecs: Vec<String>) -> FxHashSet<(String, Option<String
                     Err(errs) => errs.into_iter().for_each(|mut err| err.cancel()),
                 }
 
-                error!(r#"expected `key` or `key="value"`"#);
+                // If the user tried to use a key="value" flag, but is missing the quotes, provide
+                // a hint about how to resolve this.
+                if s.contains("=") && !s.contains("=\"") && !s.ends_with("\"") {
+                    error!(concat!(
+                        r#"expected `key` or `key="value"`, ensure escaping is appropriate"#,
+                        r#" for your shell, try 'key="value"' or key=\"value\""#
+                    ));
+                } else {
+                    error!(r#"expected `key` or `key="value"`"#);
+                }
             })
             .collect::<CrateConfig>();
         cfg.into_iter().map(|(a, b)| (a.to_string(), b.map(|b| b.to_string()))).collect()

compiler/rustc_interface/src/lib.rs

@@ -1,5 +1,6 @@
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
+#![feature(let_else)]
 #![feature(internal_output_capture)]
 #![feature(thread_spawn_unchecked)]
 #![feature(nll)]

compiler/rustc_interface/src/util.rs

@@ -717,57 +717,57 @@ impl<'a, 'b> ReplaceBodyWithLoop<'a, 'b> {
     }
 
     fn should_ignore_fn(ret_ty: &ast::FnRetTy) -> bool {
-        if let ast::FnRetTy::Ty(ref ty) = ret_ty {
-            fn involves_impl_trait(ty: &ast::Ty) -> bool {
-                match ty.kind {
-                    ast::TyKind::ImplTrait(..) => true,
-                    ast::TyKind::Slice(ref subty)
-                    | ast::TyKind::Array(ref subty, _)
-                    | ast::TyKind::Ptr(ast::MutTy { ty: ref subty, .. })
-                    | ast::TyKind::Rptr(_, ast::MutTy { ty: ref subty, .. })
-                    | ast::TyKind::Paren(ref subty) => involves_impl_trait(subty),
-                    ast::TyKind::Tup(ref tys) => any_involves_impl_trait(tys.iter()),
-                    ast::TyKind::Path(_, ref path) => {
-                        path.segments.iter().any(|seg| match seg.args.as_deref() {
-                            None => false,
-                            Some(&ast::GenericArgs::AngleBracketed(ref data)) => {
-                                data.args.iter().any(|arg| match arg {
-                                    ast::AngleBracketedArg::Arg(arg) => match arg {
-                                        ast::GenericArg::Type(ty) => involves_impl_trait(ty),
-                                        ast::GenericArg::Lifetime(_)
-                                        | ast::GenericArg::Const(_) => false,
-                                    },
-                                    ast::AngleBracketedArg::Constraint(c) => match c.kind {
-                                        ast::AssocConstraintKind::Bound { .. } => true,
-                                        ast::AssocConstraintKind::Equality { ref term } => {
-                                            match term {
-                                                Term::Ty(ty) => involves_impl_trait(ty),
-                                                // FIXME(...): This should check if the constant
-                                                // involves a trait impl, but for now ignore.
-                                                Term::Const(_) => false,
-                                            }
+        let ast::FnRetTy::Ty(ref ty) = ret_ty else {
+            return false;
+        };
+        fn involves_impl_trait(ty: &ast::Ty) -> bool {
+            match ty.kind {
+                ast::TyKind::ImplTrait(..) => true,
+                ast::TyKind::Slice(ref subty)
+                | ast::TyKind::Array(ref subty, _)
+                | ast::TyKind::Ptr(ast::MutTy { ty: ref subty, .. })
+                | ast::TyKind::Rptr(_, ast::MutTy { ty: ref subty, .. })
+                | ast::TyKind::Paren(ref subty) => involves_impl_trait(subty),
+                ast::TyKind::Tup(ref tys) => any_involves_impl_trait(tys.iter()),
+                ast::TyKind::Path(_, ref path) => {
+                    path.segments.iter().any(|seg| match seg.args.as_deref() {
+                        None => false,
+                        Some(&ast::GenericArgs::AngleBracketed(ref data)) => {
+                            data.args.iter().any(|arg| match arg {
+                                ast::AngleBracketedArg::Arg(arg) => match arg {
+                                    ast::GenericArg::Type(ty) => involves_impl_trait(ty),
+                                    ast::GenericArg::Lifetime(_) | ast::GenericArg::Const(_) => {
+                                        false
+                                    }
+                                },
+                                ast::AngleBracketedArg::Constraint(c) => match c.kind {
+                                    ast::AssocConstraintKind::Bound { .. } => true,
+                                    ast::AssocConstraintKind::Equality { ref term } => {
+                                        match term {
+                                            Term::Ty(ty) => involves_impl_trait(ty),
+                                            // FIXME(...): This should check if the constant
+                                            // involves a trait impl, but for now ignore.
+                                            Term::Const(_) => false,
                                         }
-                                    },
-                                })
-                            }
-                            Some(&ast::GenericArgs::Parenthesized(ref data)) => {
-                                any_involves_impl_trait(data.inputs.iter())
-                                    || ReplaceBodyWithLoop::should_ignore_fn(&data.output)
-                            }
-                        })
-                    }
-                    _ => false,
+                                    }
+                                },
+                            })
+                        }
+                        Some(&ast::GenericArgs::Parenthesized(ref data)) => {
+                            any_involves_impl_trait(data.inputs.iter())
+                                || ReplaceBodyWithLoop::should_ignore_fn(&data.output)
+                        }
+                    })
                 }
+                _ => false,
             }
+        }
 
-            fn any_involves_impl_trait<'a, I: Iterator<Item = &'a P<ast::Ty>>>(mut it: I) -> bool {
-                it.any(|subty| involves_impl_trait(subty))
-            }
-
-            involves_impl_trait(ty)
-        } else {
-            false
+        fn any_involves_impl_trait<'a, I: Iterator<Item = &'a P<ast::Ty>>>(mut it: I) -> bool {
+            it.any(|subty| involves_impl_trait(subty))
         }
+
+        involves_impl_trait(ty)
     }
 
     fn is_sig_const(sig: &ast::FnSig) -> bool {

compiler/rustc_mir_build/src/build/matches/mod.rs

@@ -1347,23 +1347,22 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
 
         let mut otherwise = None;
         for match_pair in match_pairs {
-            if let PatKind::Or { ref pats } = *match_pair.pattern.kind {
-                let or_span = match_pair.pattern.span;
-                let place = match_pair.place;
-
-                first_candidate.visit_leaves(|leaf_candidate| {
-                    self.test_or_pattern(
-                        leaf_candidate,
-                        &mut otherwise,
-                        pats,
-                        or_span,
-                        place.clone(),
-                        fake_borrows,
-                    );
-                });
-            } else {
+            let PatKind::Or { ref pats } = &*match_pair.pattern.kind else {
                 bug!("Or-patterns should have been sorted to the end");
-            }
+            };
+            let or_span = match_pair.pattern.span;
+            let place = match_pair.place;
+
+            first_candidate.visit_leaves(|leaf_candidate| {
+                self.test_or_pattern(
+                    leaf_candidate,
+                    &mut otherwise,
+                    pats,
+                    or_span,
+                    place.clone(),
+                    fake_borrows,
+                );
+            });
         }
 
         let remainder_start = otherwise.unwrap_or_else(|| self.cfg.start_new_block());

compiler/rustc_mir_build/src/build/matches/test.rs

@@ -88,11 +88,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         switch_ty: Ty<'tcx>,
         options: &mut FxIndexMap<&'tcx ty::Const<'tcx>, u128>,
     ) -> bool {
-        let match_pair = match candidate.match_pairs.iter().find(|mp| mp.place == *test_place) {
-            Some(match_pair) => match_pair,
-            _ => {
-                return false;
-            }
+        let Some(match_pair) = candidate.match_pairs.iter().find(|mp| mp.place == *test_place) else {
+            return false;
         };
 
         match *match_pair.pattern.kind {

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -1171,9 +1171,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
         ident: Symbol,
         kind: &AssocItemKind,
     ) -> Option<Symbol> {
-        let module = if let Some((module, _)) = self.current_trait_ref {
-            module
-        } else {
+        let Some((module, _)) = &self.current_trait_ref else {
             return None;
         };
         if ident == kw::Underscore {

compiler/rustc_resolve/src/late/lifetimes.rs

@@ -1000,46 +1000,45 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                 // `fn foo<'a>() -> MyAnonTy<'a> { ... }`
                 //          ^                 ^this gets resolved in the current scope
                 for lifetime in lifetimes {
-                    if let hir::GenericArg::Lifetime(lifetime) = lifetime {
-                        self.visit_lifetime(lifetime);
+                    let hir::GenericArg::Lifetime(lifetime) = lifetime else {
+                        continue
+                    };
+                    self.visit_lifetime(lifetime);
+
+                    // Check for predicates like `impl for<'a> Trait<impl OtherTrait<'a>>`
+                    // and ban them. Type variables instantiated inside binders aren't
+                    // well-supported at the moment, so this doesn't work.
+                    // In the future, this should be fixed and this error should be removed.
+                    let def = self.map.defs.get(&lifetime.hir_id).cloned();
+                    let Some(Region::LateBound(_, _, def_id, _)) = def else {
+                        continue
+                    };
+                    let Some(def_id) = def_id.as_local() else {
+                        continue
+                    };
+                    let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
+                    // Ensure that the parent of the def is an item, not HRTB
+                    let parent_id = self.tcx.hir().get_parent_node(hir_id);
+                    // FIXME(cjgillot) Can this check be replaced by
+                    // `let parent_is_item = parent_id.is_owner();`?
+                    let parent_is_item = if let Some(parent_def_id) = parent_id.as_owner() {
+                        matches!(self.tcx.hir().krate().owners.get(parent_def_id), Some(Some(_)),)
+                    } else {
+                        false
+                    };
 
-                        // Check for predicates like `impl for<'a> Trait<impl OtherTrait<'a>>`
-                        // and ban them. Type variables instantiated inside binders aren't
-                        // well-supported at the moment, so this doesn't work.
-                        // In the future, this should be fixed and this error should be removed.
-                        let def = self.map.defs.get(&lifetime.hir_id).cloned();
-                        if let Some(Region::LateBound(_, _, def_id, _)) = def {
-                            if let Some(def_id) = def_id.as_local() {
-                                let hir_id = self.tcx.hir().local_def_id_to_hir_id(def_id);
-                                // Ensure that the parent of the def is an item, not HRTB
-                                let parent_id = self.tcx.hir().get_parent_node(hir_id);
-                                // FIXME(cjgillot) Can this check be replaced by
-                                // `let parent_is_item = parent_id.is_owner();`?
-                                let parent_is_item =
-                                    if let Some(parent_def_id) = parent_id.as_owner() {
-                                        matches!(
-                                            self.tcx.hir().krate().owners.get(parent_def_id),
-                                            Some(Some(_)),
-                                        )
-                                    } else {
-                                        false
-                                    };
-
-                                if !parent_is_item {
-                                    if !self.trait_definition_only {
-                                        struct_span_err!(
-                                            self.tcx.sess,
-                                            lifetime.span,
-                                            E0657,
-                                            "`impl Trait` can only capture lifetimes \
-                                                bound at the fn or impl level"
-                                        )
-                                        .emit();
-                                    }
-                                    self.uninsert_lifetime_on_error(lifetime, def.unwrap());
-                                }
-                            }
+                    if !parent_is_item {
+                        if !self.trait_definition_only {
+                            struct_span_err!(
+                                self.tcx.sess,
+                                lifetime.span,
+                                E0657,
+                                "`impl Trait` can only capture lifetimes \
+                                    bound at the fn or impl level"
+                            )
+                            .emit();
                         }
+                        self.uninsert_lifetime_on_error(lifetime, def.unwrap());
                     }
                 }