Rollup of 4 pull requests

compiler/rustc_mir_transform/src/coverage/spans.rs

@@ -2,7 +2,7 @@ use std::cell::OnceCell;
 
 use rustc_data_structures::graph::WithNumNodes;
 use rustc_index::IndexVec;
-use rustc_middle::mir::{self, AggregateKind, Rvalue, Statement, StatementKind};
+use rustc_middle::mir;
 use rustc_span::{BytePos, ExpnKind, MacroKind, Span, Symbol, DUMMY_SP};
 
 use super::graph::{BasicCoverageBlock, CoverageGraph, START_BCB};
@@ -75,29 +75,15 @@ struct CoverageSpan {
 
 impl CoverageSpan {
     pub fn for_fn_sig(fn_sig_span: Span) -> Self {
-        Self {
-            span: fn_sig_span,
-            expn_span: fn_sig_span,
-            current_macro_or_none: Default::default(),
-            bcb: START_BCB,
-            merged_spans: vec![],
-            is_closure: false,
-        }
+        Self::new(fn_sig_span, fn_sig_span, START_BCB, false)
     }
 
-    pub fn for_statement(
-        statement: &Statement<'_>,
+    pub(super) fn new(
         span: Span,
         expn_span: Span,
         bcb: BasicCoverageBlock,
+        is_closure: bool,
     ) -> Self {
-        let is_closure = match statement.kind {
-            StatementKind::Assign(box (_, Rvalue::Aggregate(box ref kind, _))) => {
-                matches!(kind, AggregateKind::Closure(_, _) | AggregateKind::Generator(_, _, _))
-            }
-            _ => false,
-        };
-
         Self {
             span,
             expn_span,
@@ -108,17 +94,6 @@ impl CoverageSpan {
         }
     }
 
-    pub fn for_terminator(span: Span, expn_span: Span, bcb: BasicCoverageBlock) -> Self {
-        Self {
-            span,
-            expn_span,
-            current_macro_or_none: Default::default(),
-            bcb,
-            merged_spans: vec![span],
-            is_closure: false,
-        }
-    }
-
     pub fn merge_from(&mut self, mut other: CoverageSpan) {
         debug_assert!(self.is_mergeable(&other));
         self.span = self.span.to(other.span);

compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs

@@ -1,5 +1,7 @@
+use rustc_data_structures::captures::Captures;
 use rustc_middle::mir::{
-    self, FakeReadCause, Statement, StatementKind, Terminator, TerminatorKind,
+    self, AggregateKind, FakeReadCause, Rvalue, Statement, StatementKind, Terminator,
+    TerminatorKind,
 };
 use rustc_span::Span;
 
@@ -12,7 +14,7 @@ pub(super) fn mir_to_initial_sorted_coverage_spans(
     body_span: Span,
     basic_coverage_blocks: &CoverageGraph,
 ) -> Vec<CoverageSpan> {
-    let mut initial_spans = Vec::<CoverageSpan>::with_capacity(mir_body.basic_blocks.len() * 2);
+    let mut initial_spans = Vec::with_capacity(mir_body.basic_blocks.len() * 2);
     for (bcb, bcb_data) in basic_coverage_blocks.iter_enumerated() {
         initial_spans.extend(bcb_to_initial_coverage_spans(mir_body, body_span, bcb, bcb_data));
     }
@@ -50,34 +52,41 @@ pub(super) fn mir_to_initial_sorted_coverage_spans(
 // for each `Statement` and `Terminator`. (Note that subsequent stages of coverage analysis will
 // merge some `CoverageSpan`s, at which point a `CoverageSpan` may represent multiple
 // `Statement`s and/or `Terminator`s.)
-fn bcb_to_initial_coverage_spans(
-    mir_body: &mir::Body<'_>,
+fn bcb_to_initial_coverage_spans<'a, 'tcx>(
+    mir_body: &'a mir::Body<'tcx>,
     body_span: Span,
     bcb: BasicCoverageBlock,
-    bcb_data: &BasicCoverageBlockData,
-) -> Vec<CoverageSpan> {
-    bcb_data
-        .basic_blocks
-        .iter()
-        .flat_map(|&bb| {
-            let data = &mir_body[bb];
-            data.statements
-                .iter()
-                .filter_map(move |statement| {
-                    filtered_statement_span(statement).map(|span| {
-                        CoverageSpan::for_statement(
-                            statement,
-                            function_source_span(span, body_span),
-                            span,
-                            bcb,
-                        )
-                    })
-                })
-                .chain(filtered_terminator_span(data.terminator()).map(|span| {
-                    CoverageSpan::for_terminator(function_source_span(span, body_span), span, bcb)
-                }))
-        })
-        .collect()
+    bcb_data: &'a BasicCoverageBlockData,
+) -> impl Iterator<Item = CoverageSpan> + Captures<'a> + Captures<'tcx> {
+    bcb_data.basic_blocks.iter().flat_map(move |&bb| {
+        let data = &mir_body[bb];
+
+        let statement_spans = data.statements.iter().filter_map(move |statement| {
+            let expn_span = filtered_statement_span(statement)?;
+            let span = function_source_span(expn_span, body_span);
+
+            Some(CoverageSpan::new(span, expn_span, bcb, is_closure(statement)))
+        });
+
+        let terminator_span = Some(data.terminator()).into_iter().filter_map(move |terminator| {
+            let expn_span = filtered_terminator_span(terminator)?;
+            let span = function_source_span(expn_span, body_span);
+
+            Some(CoverageSpan::new(span, expn_span, bcb, false))
+        });
+
+        statement_spans.chain(terminator_span)
+    })
+}
+
+fn is_closure(statement: &Statement<'_>) -> bool {
+    match statement.kind {
+        StatementKind::Assign(box (_, Rvalue::Aggregate(box ref agg_kind, _))) => match agg_kind {
+            AggregateKind::Closure(_, _) | AggregateKind::Generator(_, _, _) => true,
+            _ => false,
+        },
+        _ => false,
+    }
 }
 
 /// If the MIR `Statement` has a span contributive to computing coverage spans,

compiler/rustc_resolve/src/diagnostics.rs

@@ -1511,17 +1511,30 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 ),
             );
         }
+
+        let (span, sugg, post) = if let SuggestionTarget::SimilarlyNamed = suggestion.target
+            && let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span)
+            && let Some(span) = suggestion.span
+            && let Some(candidate) = suggestion.candidate.as_str().strip_prefix("_")
+            && snippet == candidate
+        {
+            // When the suggested binding change would be from `x` to `_x`, suggest changing the
+            // original binding definition instead. (#60164)
+            (span, snippet, ", consider changing it")
+        } else {
+            (span, suggestion.candidate.to_string(), "")
+        };
         let msg = match suggestion.target {
             SuggestionTarget::SimilarlyNamed => format!(
-                "{} {} with a similar name exists",
+                "{} {} with a similar name exists{post}",
                 suggestion.res.article(),
                 suggestion.res.descr()
             ),
             SuggestionTarget::SingleItem => {
                 format!("maybe you meant this {}", suggestion.res.descr())
             }
         };
-        err.span_suggestion(span, msg, suggestion.candidate, Applicability::MaybeIncorrect);
+        err.span_suggestion(span, msg, sugg, Applicability::MaybeIncorrect);
         true
     }
 

compiler/rustc_smir/src/rustc_internal/internal.rs

@@ -0,0 +1,61 @@
+//! Module containing the translation from stable mir constructs to the rustc counterpart.
+//!
+//! This module will only include a few constructs to allow users to invoke internal rustc APIs
+//! due to incomplete stable coverage.
+
+// Prefer importing stable_mir over internal rustc constructs to make this file more readable.
+use crate::rustc_smir::{MaybeStable, Tables};
+use rustc_middle::ty::{self as rustc_ty, Ty as InternalTy};
+use stable_mir::ty::{Const, GenericArgKind, GenericArgs, Region, Ty};
+use stable_mir::DefId;
+
+use super::RustcInternal;
+
+impl<'tcx> RustcInternal<'tcx> for DefId {
+    type T = rustc_span::def_id::DefId;
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        tables.def_ids[*self]
+    }
+}
+
+impl<'tcx> RustcInternal<'tcx> for GenericArgs {
+    type T = rustc_ty::GenericArgsRef<'tcx>;
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        tables.tcx.mk_args_from_iter(self.0.iter().map(|arg| arg.internal(tables)))
+    }
+}
+
+impl<'tcx> RustcInternal<'tcx> for GenericArgKind {
+    type T = rustc_ty::GenericArg<'tcx>;
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        match self {
+            GenericArgKind::Lifetime(reg) => reg.internal(tables).into(),
+            GenericArgKind::Type(ty) => ty.internal(tables).into(),
+            GenericArgKind::Const(cnst) => cnst.internal(tables).into(),
+        }
+    }
+}
+
+impl<'tcx> RustcInternal<'tcx> for Region {
+    type T = rustc_ty::Region<'tcx>;
+    fn internal(&self, _tables: &mut Tables<'tcx>) -> Self::T {
+        todo!()
+    }
+}
+
+impl<'tcx> RustcInternal<'tcx> for Ty {
+    type T = InternalTy<'tcx>;
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T {
+        match tables.types[self.0] {
+            MaybeStable::Stable(_) => todo!(),
+            MaybeStable::Rustc(ty) => ty,
+        }
+    }
+}
+
+impl<'tcx> RustcInternal<'tcx> for Const {
+    type T = rustc_ty::Const<'tcx>;
+    fn internal(&self, _tables: &mut Tables<'tcx>) -> Self::T {
+        todo!()
+    }
+}

compiler/rustc_smir/src/rustc_internal/mod.rs

@@ -20,6 +20,8 @@ use std::fmt::Debug;
 use std::hash::Hash;
 use std::ops::{ControlFlow, Index};
 
+mod internal;
+
 impl<'tcx> Index<stable_mir::DefId> for Tables<'tcx> {
     type Output = DefId;
 
@@ -231,3 +233,11 @@ impl<K: PartialEq + Hash + Eq, V: Copy + Debug + PartialEq + IndexedVal> Index<V
         k
     }
 }
+
+/// Trait used to translate a stable construct to its rustc counterpart.
+///
+/// This is basically a mirror of [crate::rustc_smir::Stable].
+pub(crate) trait RustcInternal<'tcx> {
+    type T;
+    fn internal(&self, tables: &mut Tables<'tcx>) -> Self::T;
+}

compiler/rustc_smir/src/rustc_smir/builder.rs

@@ -0,0 +1,55 @@
+//! Logic required to produce a monomorphic stable body.
+//!
+//! We first retrieve and monomorphize the rustc body representation, i.e., we generate a
+//! monomorphic body using internal representation.
+//! After that, we convert the internal representation into a stable one.
+use crate::rustc_smir::{Stable, Tables};
+use rustc_middle::mir;
+use rustc_middle::mir::visit::MutVisitor;
+use rustc_middle::ty::{self, Ty, TyCtxt};
+
+/// Builds a monomorphic body for a given instance.
+pub struct BodyBuilder<'tcx> {
+    tcx: TyCtxt<'tcx>,
+    instance: ty::Instance<'tcx>,
+}
+
+impl<'tcx> BodyBuilder<'tcx> {
+    pub fn new(tcx: TyCtxt<'tcx>, instance: ty::Instance<'tcx>) -> Self {
+        BodyBuilder { tcx, instance }
+    }
+
+    pub fn build(mut self, tables: &mut Tables<'tcx>) -> stable_mir::mir::Body {
+        let mut body = self.tcx.instance_mir(self.instance.def).clone();
+        let generics = self.tcx.generics_of(self.instance.def_id());
+        if generics.requires_monomorphization(self.tcx) {
+            self.visit_body(&mut body);
+        }
+        body.stable(tables)
+    }
+
+    fn monomorphize<T>(&self, value: T) -> T
+    where
+        T: ty::TypeFoldable<TyCtxt<'tcx>>,
+    {
+        self.instance.instantiate_mir_and_normalize_erasing_regions(
+            self.tcx,
+            ty::ParamEnv::reveal_all(),
+            ty::EarlyBinder::bind(value),
+        )
+    }
+}
+
+impl<'tcx> MutVisitor<'tcx> for BodyBuilder<'tcx> {
+    fn visit_ty_const(&mut self, ct: &mut ty::Const<'tcx>, _location: mir::Location) {
+        *ct = self.monomorphize(*ct);
+    }
+
+    fn visit_ty(&mut self, ty: &mut Ty<'tcx>, _: mir::visit::TyContext) {
+        *ty = self.monomorphize(*ty);
+    }
+
+    fn tcx(&self) -> TyCtxt<'tcx> {
+        self.tcx
+    }
+}

compiler/rustc_smir/src/rustc_smir/mod.rs

@@ -7,7 +7,7 @@
 //!
 //! For now, we are developing everything inside `rustc`, thus, we keep this module private.
 
-use crate::rustc_internal::IndexMap;
+use crate::rustc_internal::{IndexMap, RustcInternal};
 use crate::rustc_smir::hir::def::DefKind;
 use crate::rustc_smir::stable_mir::ty::{BoundRegion, EarlyBoundRegion, Region};
 use rustc_hir as hir;
@@ -26,6 +26,7 @@ use stable_mir::{self, opaque, Context, Filename};
 use tracing::debug;
 
 mod alloc;
+mod builder;
 
 impl<'tcx> Context for Tables<'tcx> {
     fn local_crate(&self) -> stable_mir::Crate {
@@ -171,8 +172,9 @@ impl<'tcx> Context for Tables<'tcx> {
         }
     }
 
-    fn instance_body(&mut self, _def: InstanceDef) -> Body {
-        todo!("Monomorphize the body")
+    fn instance_body(&mut self, def: InstanceDef) -> Body {
+        let instance = self.instances[def];
+        builder::BodyBuilder::new(self.tcx, instance).build(self)
     }
 
     fn instance_ty(&mut self, def: InstanceDef) -> stable_mir::ty::Ty {
@@ -195,9 +197,21 @@ impl<'tcx> Context for Tables<'tcx> {
         let def_id = self[def_id];
         let generics = self.tcx.generics_of(def_id);
         let result = generics.requires_monomorphization(self.tcx);
-        println!("req {result}: {def_id:?}");
         result
     }
+
+    fn resolve_instance(
+        &mut self,
+        def: stable_mir::ty::FnDef,
+        args: &stable_mir::ty::GenericArgs,
+    ) -> Option<stable_mir::mir::mono::Instance> {
+        let def_id = def.0.internal(self);
+        let args_ref = args.internal(self);
+        match Instance::resolve(self.tcx, ParamEnv::reveal_all(), def_id, args_ref) {
+            Ok(Some(instance)) => Some(instance.stable(self)),
+            Ok(None) | Err(_) => None,
+        }
+    }
 }
 
 #[derive(Clone)]

compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -2665,6 +2665,29 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                             // Check for foreign traits being reachable.
                             self.tcx.visible_parent_map(()).get(&def_id).is_some()
                         };
+                        if Some(def_id) == self.tcx.lang_items().sized_trait()
+                            && let Some(hir::Node::TraitItem(hir::TraitItem {
+                                ident,
+                                kind: hir::TraitItemKind::Type(bounds, None),
+                                ..
+                            })) = tcx.hir().get_if_local(item_def_id)
+                            // Do not suggest relaxing if there is an explicit `Sized` obligation.
+                            && !bounds.iter()
+                                .filter_map(|bound| bound.trait_ref())
+                                .any(|tr| tr.trait_def_id() == self.tcx.lang_items().sized_trait())
+                        {
+                            let (span, separator) = if let [.., last] = bounds {
+                                (last.span().shrink_to_hi(), " +")
+                            } else {
+                                (ident.span.shrink_to_hi(), ":")
+                            };
+                            err.span_suggestion_verbose(
+                                span,
+                                "consider relaxing the implicit `Sized` restriction",
+                                format!("{separator} ?Sized"),
+                                Applicability::MachineApplicable,
+                            );
+                        }
                         if let DefKind::Trait = tcx.def_kind(item_def_id)
                             && !visible_item
                         {