Auto merge of #105378 - matthiaskrgr:rollup-fjeorw5, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - #104898 (Put all cached values into a central struct instead of just the stable hash)
 - #105004 (Fix `emit_unused_delims_expr` ICE)
 - #105174 (Suggest removing struct field from destructive binding only in shorthand scenario)
 - #105250 (Replace usage of `ResumeTy` in async lowering with `Context`)
 - #105286 (Add -Z maximal-hir-to-mir-coverage flag)
 - #105320 (rustdoc: simplify CSS selectors on top-doc and non-exhaustive toggles)
 - #105349 (Point at args in associated const fn pointers)
 - #105362 (Cleanup macro-expanded code in `rustc_type_ir`)
 - #105370 (Remove outdated syntax from trait alias pretty printing)

Failed merges:

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

compiler/rustc_ast_lowering/src/expr.rs

@@ -16,7 +16,7 @@ use rustc_hir::def::Res;
 use rustc_hir::definitions::DefPathData;
 use rustc_session::errors::report_lit_error;
 use rustc_span::source_map::{respan, DesugaringKind, Span, Spanned};
-use rustc_span::symbol::{sym, Ident};
+use rustc_span::symbol::{kw, sym, Ident};
 use rustc_span::DUMMY_SP;
 use thin_vec::thin_vec;
 
@@ -594,14 +594,38 @@ impl<'hir> LoweringContext<'_, 'hir> {
     ) -> hir::ExprKind<'hir> {
         let output = ret_ty.unwrap_or_else(|| hir::FnRetTy::DefaultReturn(self.lower_span(span)));
 
-        // Resume argument type: `ResumeTy`
-        let unstable_span =
-            self.mark_span_with_reason(DesugaringKind::Async, span, self.allow_gen_future.clone());
-        let resume_ty = hir::QPath::LangItem(hir::LangItem::ResumeTy, unstable_span, None);
+        // Resume argument type, which should be `&mut Context<'_>`.
+        // NOTE: Using the `'static` lifetime here is technically cheating.
+        // The `Future::poll` argument really is `&'a mut Context<'b>`, but we cannot
+        // express the fact that we are not storing it across yield-points yet,
+        // and we would thus run into lifetime errors.
+        // See <https://github.com/rust-lang/rust/issues/68923>.
+        // Our lowering makes sure we are not mis-using the `_task_context` input type
+        // in the sense that we are indeed not using it across yield points. We
+        // get a fresh `&mut Context` for each resume / call of `Future::poll`.
+        // This "cheating" was previously done with a `ResumeTy` that contained a raw
+        // pointer, and a `get_context` accessor that pulled the `Context` lifetimes
+        // out of thin air.
+        let context_lifetime_ident = Ident::with_dummy_span(kw::StaticLifetime);
+        let context_lifetime = self.arena.alloc(hir::Lifetime {
+            hir_id: self.next_id(),
+            ident: context_lifetime_ident,
+            res: hir::LifetimeName::Static,
+        });
+        let context_path =
+            hir::QPath::LangItem(hir::LangItem::Context, self.lower_span(span), None);
+        let context_ty = hir::MutTy {
+            ty: self.arena.alloc(hir::Ty {
+                hir_id: self.next_id(),
+                kind: hir::TyKind::Path(context_path),
+                span: self.lower_span(span),
+            }),
+            mutbl: hir::Mutability::Mut,
+        };
         let input_ty = hir::Ty {
             hir_id: self.next_id(),
-            kind: hir::TyKind::Path(resume_ty),
-            span: unstable_span,
+            kind: hir::TyKind::Rptr(context_lifetime, context_ty),
+            span: self.lower_span(span),
         };
 
         // The closure/generator `FnDecl` takes a single (resume) argument of type `input_ty`.
@@ -659,12 +683,9 @@ impl<'hir> LoweringContext<'_, 'hir> {
             .map_or(false, |attrs| attrs.into_iter().any(|attr| attr.has_name(sym::track_caller)));
 
         let hir_id = self.lower_node_id(closure_node_id);
+        let unstable_span =
+            self.mark_span_with_reason(DesugaringKind::Async, span, self.allow_gen_future.clone());
         if track_caller {
-            let unstable_span = self.mark_span_with_reason(
-                DesugaringKind::Async,
-                span,
-                self.allow_gen_future.clone(),
-            );
             self.lower_attrs(
                 hir_id,
                 &[Attribute {
@@ -711,7 +732,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
     ///     mut __awaitee => loop {
     ///         match unsafe { ::std::future::Future::poll(
     ///             <::std::pin::Pin>::new_unchecked(&mut __awaitee),
-    ///             ::std::future::get_context(task_context),
+    ///             task_context,
     ///         ) } {
     ///             ::std::task::Poll::Ready(result) => break result,
     ///             ::std::task::Poll::Pending => {}
@@ -752,7 +773,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         // unsafe {
         //     ::std::future::Future::poll(
         //         ::std::pin::Pin::new_unchecked(&mut __awaitee),
-        //         ::std::future::get_context(task_context),
+        //         task_context,
         //     )
         // }
         let poll_expr = {
@@ -770,16 +791,10 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 arena_vec![self; ref_mut_awaitee],
                 Some(expr_hir_id),
             );
-            let get_context = self.expr_call_lang_item_fn_mut(
-                gen_future_span,
-                hir::LangItem::GetContext,
-                arena_vec![self; task_context],
-                Some(expr_hir_id),
-            );
             let call = self.expr_call_lang_item_fn(
                 span,
                 hir::LangItem::FuturePoll,
-                arena_vec![self; new_unchecked, get_context],
+                arena_vec![self; new_unchecked, task_context],
                 Some(expr_hir_id),
             );
             self.arena.alloc(self.expr_unsafe(call))

compiler/rustc_ast_pretty/src/pprust/state/item.rs

@@ -348,21 +348,10 @@ impl<'a> State<'a> {
                 self.head(visibility_qualified(&item.vis, "trait"));
                 self.print_ident(item.ident);
                 self.print_generic_params(&generics.params);
-                let mut real_bounds = Vec::with_capacity(bounds.len());
-                // FIXME(durka) this seems to be some quite outdated syntax
-                for b in bounds.iter() {
-                    if let GenericBound::Trait(ptr, ast::TraitBoundModifier::Maybe) = b {
-                        self.space();
-                        self.word_space("for ?");
-                        self.print_trait_ref(&ptr.trait_ref);
-                    } else {
-                        real_bounds.push(b.clone());
-                    }
-                }
                 self.nbsp();
-                if !real_bounds.is_empty() {
+                if !bounds.is_empty() {
                     self.word_nbsp("=");
-                    self.print_type_bounds(&real_bounds);
+                    self.print_type_bounds(&bounds);
                 }
                 self.print_where_clause(&generics.where_clause);
                 self.word(";");

compiler/rustc_data_structures/src/intern.rs

@@ -4,8 +4,6 @@ use std::hash::{Hash, Hasher};
 use std::ops::Deref;
 use std::ptr;
 
-use crate::fingerprint::Fingerprint;
-
 mod private {
     #[derive(Clone, Copy, Debug)]
     pub struct PrivateZst;
@@ -110,86 +108,5 @@ where
     }
 }
 
-/// A helper type that you can wrap round your own type in order to automatically
-/// cache the stable hash on creation and not recompute it whenever the stable hash
-/// of the type is computed.
-/// This is only done in incremental mode. You can also opt out of caching by using
-/// StableHash::ZERO for the hash, in which case the hash gets computed each time.
-/// This is useful if you have values that you intern but never (can?) use for stable
-/// hashing.
-#[derive(Copy, Clone)]
-pub struct WithStableHash<T> {
-    pub internee: T,
-    pub stable_hash: Fingerprint,
-}
-
-impl<T: PartialEq> PartialEq for WithStableHash<T> {
-    #[inline]
-    fn eq(&self, other: &Self) -> bool {
-        self.internee.eq(&other.internee)
-    }
-}
-
-impl<T: Eq> Eq for WithStableHash<T> {}
-
-impl<T: Ord> PartialOrd for WithStableHash<T> {
-    fn partial_cmp(&self, other: &WithStableHash<T>) -> Option<Ordering> {
-        Some(self.internee.cmp(&other.internee))
-    }
-}
-
-impl<T: Ord> Ord for WithStableHash<T> {
-    fn cmp(&self, other: &WithStableHash<T>) -> Ordering {
-        self.internee.cmp(&other.internee)
-    }
-}
-
-impl<T> Deref for WithStableHash<T> {
-    type Target = T;
-
-    #[inline]
-    fn deref(&self) -> &T {
-        &self.internee
-    }
-}
-
-impl<T: Hash> Hash for WithStableHash<T> {
-    #[inline]
-    fn hash<H: Hasher>(&self, s: &mut H) {
-        if self.stable_hash != Fingerprint::ZERO {
-            self.stable_hash.hash(s)
-        } else {
-            self.internee.hash(s)
-        }
-    }
-}
-
-impl<T: HashStable<CTX>, CTX> HashStable<CTX> for WithStableHash<T> {
-    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
-        if self.stable_hash == Fingerprint::ZERO || cfg!(debug_assertions) {
-            // No cached hash available. This can only mean that incremental is disabled.
-            // We don't cache stable hashes in non-incremental mode, because they are used
-            // so rarely that the performance actually suffers.
-
-            // We need to build the hash as if we cached it and then hash that hash, as
-            // otherwise the hashes will differ between cached and non-cached mode.
-            let stable_hash: Fingerprint = {
-                let mut hasher = StableHasher::new();
-                self.internee.hash_stable(hcx, &mut hasher);
-                hasher.finish()
-            };
-            if cfg!(debug_assertions) && self.stable_hash != Fingerprint::ZERO {
-                assert_eq!(
-                    stable_hash, self.stable_hash,
-                    "cached stable hash does not match freshly computed stable hash"
-                );
-            }
-            stable_hash.hash_stable(hcx, hasher);
-        } else {
-            self.stable_hash.hash_stable(hcx, hasher);
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests;

compiler/rustc_hir/src/lang_items.rs

@@ -286,10 +286,9 @@ language_item_table! {
 
     // FIXME(swatinem): the following lang items are used for async lowering and
     // should become obsolete eventually.
-    ResumeTy,                sym::ResumeTy,            resume_ty,                  Target::Struct,         GenericRequirement::None;
     IdentityFuture,          sym::identity_future,     identity_future_fn,         Target::Fn,             GenericRequirement::None;
-    GetContext,              sym::get_context,         get_context_fn,             Target::Fn,             GenericRequirement::None;
 
+    Context,                 sym::Context,             context,                    Target::Struct,         GenericRequirement::None;
     FuturePoll,              sym::poll,                future_poll_fn,             Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
 
     FromFrom,                sym::from,                from_fn,                    Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;

compiler/rustc_hir_pretty/src/lib.rs

@@ -695,19 +695,8 @@ impl<'a> State<'a> {
                 self.head("trait");
                 self.print_ident(item.ident);
                 self.print_generic_params(generics.params);
-                let mut real_bounds = Vec::with_capacity(bounds.len());
-                // FIXME(durka) this seems to be some quite outdated syntax
-                for b in bounds {
-                    if let GenericBound::Trait(ptr, hir::TraitBoundModifier::Maybe) = b {
-                        self.space();
-                        self.word_space("for ?");
-                        self.print_trait_ref(&ptr.trait_ref);
-                    } else {
-                        real_bounds.push(b);
-                    }
-                }
                 self.nbsp();
-                self.print_bounds("=", real_bounds);
+                self.print_bounds("=", bounds);
                 self.print_where_clause(generics);
                 self.word(";");
                 self.end(); // end inner head-block

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -1918,15 +1918,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         receiver: Option<&'tcx hir::Expr<'tcx>>,
         args: &'tcx [hir::Expr<'tcx>],
     ) -> bool {
-        // Do not call `fn_sig` on non-functions.
-        if !matches!(
-            self.tcx.def_kind(def_id),
-            DefKind::Fn | DefKind::AssocFn | DefKind::Variant | DefKind::Ctor(..)
-        ) {
+        let ty = self.tcx.type_of(def_id);
+        if !ty.is_fn() {
             return false;
         }
-
-        let sig = self.tcx.fn_sig(def_id).skip_binder();
+        let sig = ty.fn_sig(self.tcx).skip_binder();
         let args_referencing_param: Vec<_> = sig
             .inputs()
             .iter()

compiler/rustc_interface/src/tests.rs

@@ -747,6 +747,7 @@ fn test_unstable_options_tracking_hash() {
     tracked!(link_only, true);
     tracked!(llvm_plugins, vec![String::from("plugin_name")]);
     tracked!(location_detail, LocationDetail { file: true, line: false, column: false });
+    tracked!(maximal_hir_to_mir_coverage, true);
     tracked!(merge_functions, Some(MergeFunctions::Disabled));
     tracked!(mir_emit_retag, true);
     tracked!(mir_enable_passes, vec![("DestProp".to_string(), false)]);

compiler/rustc_lint/src/pass_by_value.rs

@@ -10,7 +10,7 @@ declare_tool_lint! {
     /// The `rustc_pass_by_value` lint marks a type with `#[rustc_pass_by_value]` requiring it to
     /// always be passed by value. This is usually used for types that are thin wrappers around
     /// references, so there is no benefit to an extra layer of indirection. (Example: `Ty` which
-    /// is a reference to an `Interned<TyS>`)
+    /// is a reference to an `Interned<TyKind>`)
     pub rustc::PASS_BY_VALUE,
     Warn,
     "pass by reference of a type flagged as `#[rustc_pass_by_value]`",

compiler/rustc_lint/src/unused.rs

@@ -633,13 +633,34 @@ trait UnusedDelimLint {
         left_pos: Option<BytePos>,
         right_pos: Option<BytePos>,
     ) {
+        // If `value` has `ExprKind::Err`, unused delim lint can be broken.
+        // For example, the following code caused ICE.
+        // This is because the `ExprKind::Call` in `value` has `ExprKind::Err` as its argument
+        // and this leads to wrong spans. #104897
+        //
+        // ```
+        // fn f(){(print!(á
+        // ```
+        use rustc_ast::visit::{walk_expr, Visitor};
+        struct ErrExprVisitor {
+            has_error: bool,
+        }
+        impl<'ast> Visitor<'ast> for ErrExprVisitor {
+            fn visit_expr(&mut self, expr: &'ast ast::Expr) {
+                if let ExprKind::Err = expr.kind {
+                    self.has_error = true;
+                    return;
+                }
+                walk_expr(self, expr)
+            }
+        }
+        let mut visitor = ErrExprVisitor { has_error: false };
+        visitor.visit_expr(value);
+        if visitor.has_error {
+            return;
+        }
         let spans = match value.kind {
             ast::ExprKind::Block(ref block, None) if block.stmts.len() == 1 => {
-                if let StmtKind::Expr(expr) = &block.stmts[0].kind
-                    && let ExprKind::Err = expr.kind
-                {
-                    return
-                }
                 if let Some(span) = block.stmts[0].span.find_ancestor_inside(value.span) {
                     Some((value.span.with_hi(span.lo()), value.span.with_lo(span.hi())))
                 } else {

compiler/rustc_middle/src/arena.rs

@@ -1,3 +1,5 @@
+#![allow(rustc::usage_of_ty_tykind)]
+
 /// This higher-order macro declares a list of types which can be allocated by `Arena`.
 ///
 /// Specifying the `decode` modifier will add decode impls for `&T` and `&[T]` where `T` is the type
@@ -89,8 +91,8 @@ macro_rules! arena_types {
             [] hir_id_set: rustc_hir::HirIdSet,
 
             // Interned types
-            [] tys: rustc_data_structures::intern::WithStableHash<rustc_middle::ty::TyS<'tcx>>,
-            [] predicates: rustc_data_structures::intern::WithStableHash<rustc_middle::ty::PredicateS<'tcx>>,
+            [] tys: rustc_type_ir::WithCachedTypeInfo<rustc_middle::ty::TyKind<'tcx>>,
+            [] predicates: rustc_type_ir::WithCachedTypeInfo<rustc_middle::ty::PredicateKind<'tcx>>,
             [] consts: rustc_middle::ty::ConstS<'tcx>,
 
             // Note that this deliberately duplicates items in the `rustc_hir::arena`,

compiler/rustc_middle/src/mir/interpret/allocation.rs

@@ -103,7 +103,7 @@ impl hash::Hash for Allocation {
 /// Interned types generally have an `Outer` type and an `Inner` type, where
 /// `Outer` is a newtype around `Interned<Inner>`, and all the operations are
 /// done on `Outer`, because all occurrences are interned. E.g. `Ty` is an
-/// outer type and `TyS` is its inner type.
+/// outer type and `TyKind` is its inner type.
 ///
 /// Here things are different because only const allocations are interned. This
 /// means that both the inner type (`Allocation`) and the outer type