Rollup of 2 pull requests

compiler/rustc_attr_parsing/src/attributes/rustc_internal.rs

@@ -778,6 +778,30 @@ impl<S: Stage> NoArgsAttributeParser<S> for RustcEffectiveVisibilityParser {
     const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcEffectiveVisibility;
 }
 
+pub(crate) struct RustcDoNotConstCheckParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for RustcDoNotConstCheckParser {
+    const PATH: &[Symbol] = &[sym::rustc_do_not_const_check];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[
+        Allow(Target::Fn),
+        Allow(Target::Method(MethodKind::Inherent)),
+        Allow(Target::Method(MethodKind::TraitImpl)),
+        Allow(Target::Method(MethodKind::Trait { body: false })),
+        Allow(Target::Method(MethodKind::Trait { body: true })),
+    ]);
+    const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcDoNotConstCheck;
+}
+
+pub(crate) struct RustcNonnullOptimizationGuaranteedParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for RustcNonnullOptimizationGuaranteedParser {
+    const PATH: &[Symbol] = &[sym::rustc_nonnull_optimization_guaranteed];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[Allow(Target::Struct)]);
+    const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcNonnullOptimizationGuaranteed;
+}
+
 pub(crate) struct RustcSymbolName;
 
 impl<S: Stage> SingleAttributeParser<S> for RustcSymbolName {

compiler/rustc_attr_parsing/src/context.rs

@@ -263,6 +263,7 @@ attribute_parsers!(
         Single<WithoutArgs<RustcCoherenceIsCoreParser>>,
         Single<WithoutArgs<RustcDeallocatorParser>>,
         Single<WithoutArgs<RustcDelayedBugFromInsideQueryParser>>,
+        Single<WithoutArgs<RustcDoNotConstCheckParser>>,
         Single<WithoutArgs<RustcDumpDefParentsParser>>,
         Single<WithoutArgs<RustcDumpItemBoundsParser>>,
         Single<WithoutArgs<RustcDumpPredicatesParser>>,
@@ -281,6 +282,7 @@ attribute_parsers!(
         Single<WithoutArgs<RustcNeverReturnsNullPointerParser>>,
         Single<WithoutArgs<RustcNoImplicitAutorefsParser>>,
         Single<WithoutArgs<RustcNonConstTraitMethodParser>>,
+        Single<WithoutArgs<RustcNonnullOptimizationGuaranteedParser>>,
         Single<WithoutArgs<RustcNounwindParser>>,
         Single<WithoutArgs<RustcOffloadKernelParser>>,
         Single<WithoutArgs<RustcOutlivesParser>>,

compiler/rustc_const_eval/src/check_consts/check.rs

@@ -7,9 +7,10 @@ use std::ops::Deref;
 
 use rustc_data_structures::assert_matches;
 use rustc_errors::{Diag, ErrorGuaranteed};
+use rustc_hir::attrs::AttributeKind;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
-use rustc_hir::{self as hir, LangItem};
+use rustc_hir::{self as hir, LangItem, find_attr};
 use rustc_index::bit_set::DenseBitSet;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::mir::visit::Visitor;
@@ -215,7 +216,7 @@ impl<'mir, 'tcx> Checker<'mir, 'tcx> {
             return;
         }
 
-        if !tcx.has_attr(def_id, sym::rustc_do_not_const_check) {
+        if !find_attr!(tcx.get_all_attrs(def_id), AttributeKind::RustcDoNotConstCheck) {
             self.visit_body(body);
         }
 

compiler/rustc_const_eval/src/check_consts/post_drop_elaboration.rs

@@ -1,3 +1,5 @@
+use rustc_hir::attrs::AttributeKind;
+use rustc_hir::find_attr;
 use rustc_middle::mir::visit::Visitor;
 use rustc_middle::mir::{self, BasicBlock, Location};
 use rustc_middle::ty::TyCtxt;
@@ -34,7 +36,7 @@ pub fn check_live_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mir::Body<'tcx>) {
         return;
     }
 
-    if tcx.has_attr(body.source.def_id(), sym::rustc_do_not_const_check) {
+    if find_attr!(tcx.get_all_attrs(body.source.def_id()), AttributeKind::RustcDoNotConstCheck) {
         return;
     }
 

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -6,8 +6,9 @@ use rustc_abi::{Align, Size};
 use rustc_ast::Mutability;
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap, IndexEntry};
 use rustc_errors::inline_fluent;
+use rustc_hir::attrs::AttributeKind;
 use rustc_hir::def_id::{DefId, LocalDefId};
-use rustc_hir::{self as hir, CRATE_HIR_ID, LangItem};
+use rustc_hir::{self as hir, CRATE_HIR_ID, LangItem, find_attr};
 use rustc_middle::mir::AssertMessage;
 use rustc_middle::mir::interpret::{Pointer, ReportedErrorInfo};
 use rustc_middle::query::TyCtxtAt;
@@ -440,7 +441,9 @@ impl<'tcx> interpret::Machine<'tcx> for CompileTimeMachine<'tcx> {
             // sensitive check here. But we can at least rule out functions that are not const at
             // all. That said, we have to allow calling functions inside a `const trait`. These
             // *are* const-checked!
-            if !ecx.tcx.is_const_fn(def) || ecx.tcx.has_attr(def, sym::rustc_do_not_const_check) {
+            if !ecx.tcx.is_const_fn(def)
+                || find_attr!(ecx.tcx.get_all_attrs(def), AttributeKind::RustcDoNotConstCheck)
+            {
                 // We certainly do *not* want to actually call the fn
                 // though, so be sure we return here.
                 throw_unsup_format!("calling non-const function `{}`", instance)

compiler/rustc_const_eval/src/interpret/call.rs

@@ -7,11 +7,12 @@ use either::{Left, Right};
 use rustc_abi::{self as abi, ExternAbi, FieldIdx, Integer, VariantIdx};
 use rustc_data_structures::assert_matches;
 use rustc_errors::inline_fluent;
+use rustc_hir::attrs::AttributeKind;
 use rustc_hir::def_id::DefId;
+use rustc_hir::find_attr;
 use rustc_middle::ty::layout::{IntegerExt, TyAndLayout};
 use rustc_middle::ty::{self, AdtDef, Instance, Ty, VariantDef};
 use rustc_middle::{bug, mir, span_bug};
-use rustc_span::sym;
 use rustc_target::callconv::{ArgAbi, FnAbi, PassMode};
 use tracing::field::Empty;
 use tracing::{info, instrument, trace};
@@ -142,7 +143,10 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         // Check if the inner type is one of the NPO-guaranteed ones.
         // For that we first unpeel transparent *structs* (but not unions).
         let is_npo = |def: AdtDef<'tcx>| {
-            self.tcx.has_attr(def.did(), sym::rustc_nonnull_optimization_guaranteed)
+            find_attr!(
+                self.tcx.get_all_attrs(def.did()),
+                AttributeKind::RustcNonnullOptimizationGuaranteed
+            )
         };
         let inner = self.unfold_transparent(inner, /* may_unfold */ |def| {
             // Stop at NPO types so that we don't miss that attribute in the check below!

compiler/rustc_hir/src/attrs/data_structures.rs

@@ -1090,6 +1090,9 @@ pub enum AttributeKind {
     /// Represents `#[rustc_deny_explicit_impl]`.
     RustcDenyExplicitImpl(Span),
 
+    /// Represents `#[rustc_do_not_const_check]`
+    RustcDoNotConstCheck,
+
     /// Represents `#[rustc_dummy]`.
     RustcDummy,
 
@@ -1177,6 +1180,9 @@ pub enum AttributeKind {
     /// Represents `#[rustc_non_const_trait_method]`.
     RustcNonConstTraitMethod,
 
+    /// Represents `#[rustc_nonnull_optimization_guaranteed]`.
+    RustcNonnullOptimizationGuaranteed,
+
     /// Represents `#[rustc_nounwind]`
     RustcNounwind,
 

compiler/rustc_hir/src/attrs/encode_cross_crate.rs

@@ -108,6 +108,7 @@ impl AttributeKind {
             RustcDefPath(..) => No,
             RustcDelayedBugFromInsideQuery => No,
             RustcDenyExplicitImpl(..) => No,
+            RustcDoNotConstCheck => Yes,
             RustcDummy => No,
             RustcDumpDefParents => No,
             RustcDumpItemBounds => No,
@@ -137,6 +138,7 @@ impl AttributeKind {
             RustcNeverReturnsNullPointer => Yes,
             RustcNoImplicitAutorefs => Yes,
             RustcNonConstTraitMethod => No, // should be reported via other queries like `constness`
+            RustcNonnullOptimizationGuaranteed => Yes,
             RustcNounwind => No,
             RustcObjcClass { .. } => No,
             RustcObjcSelector { .. } => No,

compiler/rustc_hir_typeck/src/callee.rs

@@ -914,7 +914,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         // If we have `rustc_do_not_const_check`, do not check `[const]` bounds.
-        if self.has_rustc_attrs && self.tcx.has_attr(self.body_id, sym::rustc_do_not_const_check) {
+        if self.has_rustc_attrs
+            && find_attr!(self.tcx.get_all_attrs(self.body_id), AttributeKind::RustcDoNotConstCheck)
+        {
             return;
         }
 

compiler/rustc_lint/src/types.rs

@@ -1,7 +1,8 @@
 use std::iter;
 
 use rustc_abi::{BackendRepr, TagEncoding, Variants, WrappingRange};
-use rustc_hir::{Expr, ExprKind, HirId, LangItem};
+use rustc_hir::attrs::AttributeKind;
+use rustc_hir::{Expr, ExprKind, HirId, LangItem, find_attr};
 use rustc_middle::bug;
 use rustc_middle::ty::layout::{LayoutOf, SizeSkeleton};
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt};
@@ -686,7 +687,7 @@ pub(crate) fn nonnull_optimization_guaranteed<'tcx>(
     tcx: TyCtxt<'tcx>,
     def: ty::AdtDef<'tcx>,
 ) -> bool {
-    tcx.has_attr(def.did(), sym::rustc_nonnull_optimization_guaranteed)
+    find_attr!(tcx.get_all_attrs(def.did()), AttributeKind::RustcNonnullOptimizationGuaranteed)
 }
 
 /// `repr(transparent)` structs can have a single non-1-ZST field, this function returns that

compiler/rustc_middle/src/ty/context/tls.rs

@@ -16,8 +16,7 @@ pub struct ImplicitCtxt<'a, 'tcx> {
     /// The current `TyCtxt`.
     pub tcx: TyCtxt<'tcx>,
 
-    /// The current query job, if any. This is updated by `JobOwner::start` in
-    /// `ty::query::plumbing` when executing a query.
+    /// The current query job, if any.
     pub query: Option<QueryJobId>,
 
     /// Used to prevent queries from calling too deeply.

compiler/rustc_passes/src/check_attr.rs

@@ -303,6 +303,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::RustcDefPath(..)
                     | AttributeKind::RustcDelayedBugFromInsideQuery
                     | AttributeKind::RustcDenyExplicitImpl(..)
+                    | AttributeKind::RustcDoNotConstCheck
                     | AttributeKind::RustcDummy
                     | AttributeKind::RustcDumpDefParents
                     | AttributeKind::RustcDumpItemBounds
@@ -330,6 +331,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::RustcNeverReturnsNullPointer
                     | AttributeKind::RustcNoImplicitAutorefs
                     | AttributeKind::RustcNonConstTraitMethod
+                    | AttributeKind::RustcNonnullOptimizationGuaranteed
                     | AttributeKind::RustcNounwind
                     | AttributeKind::RustcObjcClass { .. }
                     | AttributeKind::RustcObjcSelector { .. }
@@ -390,11 +392,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             | sym::rustc_diagnostic_item
                             | sym::rustc_no_mir_inline
                             | sym::rustc_insignificant_dtor
-                            | sym::rustc_nonnull_optimization_guaranteed
                             | sym::rustc_inherit_overflow_checks
                             | sym::rustc_trivial_field_reads
                             | sym::rustc_on_unimplemented
-                            | sym::rustc_do_not_const_check
                             | sym::rustc_reservation_impl
                             | sym::rustc_doc_primitive
                             | sym::rustc_conversion_suggestion

compiler/rustc_query_impl/src/execution.rs

@@ -83,14 +83,18 @@ pub(crate) fn gather_active_jobs_inner<'tcx, K: Copy>(
     Some(())
 }
 
-/// A type representing the responsibility to execute the job in the `job` field.
-/// This will poison the relevant query if dropped.
-struct JobOwner<'tcx, K>
+/// Guard object representing the responsibility to execute a query job and
+/// mark it as completed.
+///
+/// This will poison the relevant query key if it is dropped without calling
+/// [`Self::complete`].
+struct ActiveJobGuard<'tcx, K>
 where
     K: Eq + Hash + Copy,
 {
     state: &'tcx QueryState<'tcx, K>,
     key: K,
+    key_hash: u64,
 }
 
 #[cold]
@@ -139,20 +143,19 @@ where
     }
 }
 
-impl<'tcx, K> JobOwner<'tcx, K>
+impl<'tcx, K> ActiveJobGuard<'tcx, K>
 where
     K: Eq + Hash + Copy,
 {
     /// Completes the query by updating the query cache with the `result`,
-    /// signals the waiter and forgets the JobOwner, so it won't poison the query
-    fn complete<C>(self, cache: &C, key_hash: u64, result: C::Value, dep_node_index: DepNodeIndex)
+    /// signals the waiter, and forgets the guard so it won't poison the query.
+    fn complete<C>(self, cache: &C, result: C::Value, dep_node_index: DepNodeIndex)
     where
         C: QueryCache<Key = K>,
     {
-        let key = self.key;
-        let state = self.state;
-
-        // Forget ourself so our destructor won't poison the query
+        // Forget ourself so our destructor won't poison the query.
+        // (Extract fields by value first to make sure we don't leak anything.)
+        let Self { state, key, key_hash }: Self = self;
         mem::forget(self);
 
         // Mark as complete before we remove the job from the active state
@@ -176,19 +179,18 @@ where
     }
 }
 
-impl<'tcx, K> Drop for JobOwner<'tcx, K>
+impl<'tcx, K> Drop for ActiveJobGuard<'tcx, K>
 where
     K: Eq + Hash + Copy,
 {
     #[inline(never)]
     #[cold]
     fn drop(&mut self) {
         // Poison the query so jobs waiting on it panic.
-        let state = self.state;
+        let Self { state, key, key_hash } = *self;
         let job = {
-            let key_hash = sharded::make_hash(&self.key);
             let mut shard = state.active.lock_shard_by_hash(key_hash);
-            match shard.find_entry(key_hash, equivalent_key(&self.key)) {
+            match shard.find_entry(key_hash, equivalent_key(&key)) {
                 Err(_) => panic!(),
                 Ok(occupied) => {
                     let ((key, value), vacant) = occupied.remove();
@@ -356,11 +358,13 @@ fn execute_job<'tcx, Q, const INCR: bool>(
 where
     Q: QueryDispatcher<'tcx, Qcx = QueryCtxt<'tcx>>,
 {
-    // Use `JobOwner` so the query will be poisoned if executing it panics.
-    let job_owner = JobOwner { state, key };
+    // Set up a guard object that will automatically poison the query if a
+    // panic occurs while executing the query (or any intermediate plumbing).
+    let job_guard = ActiveJobGuard { state, key, key_hash };
 
     debug_assert_eq!(qcx.tcx.dep_graph.is_fully_enabled(), INCR);
 
+    // Delegate to another function to actually execute the query job.
     let (result, dep_node_index) = if INCR {
         execute_job_incr(query, qcx, qcx.tcx.dep_graph.data().unwrap(), key, dep_node, id)
     } else {
@@ -402,7 +406,9 @@ where
             }
         }
     }
-    job_owner.complete(cache, key_hash, result, dep_node_index);
+
+    // Tell the guard to perform completion bookkeeping, and also to not poison the query.
+    job_guard.complete(cache, result, dep_node_index);
 
     (result, Some(dep_node_index))
 }

tests/ui/feature-gates/feature-gate-rustc-attrs-1.rs

@@ -5,10 +5,12 @@
 //~| NOTE the `#[rustc_nonnull_optimization_guaranteed]` attribute is an internal implementation detail that will never be stable
 //~| NOTE  the `#[rustc_nonnull_optimization_guaranteed]` attribute is just used to document guaranteed niche optimizations in the standard library
 //~| NOTE the compiler does not even check whether the type indeed is being non-null-optimized; it is your responsibility to ensure that the attribute is only used on types that are optimized
-fn main() {}
+struct Foo {}
 
 #[rustc_variance]
 //~^ ERROR use of an internal attribute [E0658]
 //~| NOTE the `#[rustc_variance]` attribute is an internal implementation detail that will never be stable
 //~| NOTE the `#[rustc_variance]` attribute is used for rustc unit tests
 enum E {}
+
+fn main() {}