Auto merge of #125824 - matthiaskrgr:rollup-eam7i0p, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #125652 (Revert propagation of drop-live information from Polonius)
 - #125730 (Apply `x clippy --fix` and `x fmt` on Rustc)
 - #125756 (coverage: Optionally instrument the RHS of lazy logical operators)
 - #125776 (Stop using `translate_args` in the new solver)
 - #125796 (Also InstSimplify `&raw*`)
 - #125807 (Also resolve the type of constants, even if we already turned it into an error constant)
 - #125816 (Don't build the `rust-demangler` binary for coverage tests)

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

compiler/rustc_borrowck/src/type_check/liveness/mod.rs

@@ -14,7 +14,6 @@ use std::rc::Rc;
 use crate::{
     constraints::OutlivesConstraintSet,
     facts::{AllFacts, AllFactsExt},
-    location::LocationTable,
     region_infer::values::LivenessValues,
     universal_regions::UniversalRegions,
 };
@@ -39,7 +38,6 @@ pub(super) fn generate<'mir, 'tcx>(
     elements: &Rc<DenseLocationMap>,
     flow_inits: &mut ResultsCursor<'mir, 'tcx, MaybeInitializedPlaces<'mir, 'tcx>>,
     move_data: &MoveData<'tcx>,
-    location_table: &LocationTable,
     use_polonius: bool,
 ) {
     debug!("liveness::generate");
@@ -53,11 +51,9 @@ pub(super) fn generate<'mir, 'tcx>(
         compute_relevant_live_locals(typeck.tcx(), &free_regions, body);
     let facts_enabled = use_polonius || AllFacts::enabled(typeck.tcx());
 
-    let polonius_drop_used = facts_enabled.then(|| {
+    if facts_enabled {
-        let mut drop_used = Vec::new();
+        polonius::populate_access_facts(typeck, body, move_data);
-        polonius::populate_access_facts(typeck, body, location_table, move_data, &mut drop_used);
+    };
-        drop_used
-    });
 
     trace::trace(
         typeck,
@@ -67,7 +63,6 @@ pub(super) fn generate<'mir, 'tcx>(
         move_data,
         relevant_live_locals,
         boring_locals,
-        polonius_drop_used,
     );
 
     // Mark regions that should be live where they appear within rvalues or within a call: like

compiler/rustc_borrowck/src/type_check/liveness/polonius.rs

@@ -85,13 +85,10 @@ impl<'a, 'tcx> Visitor<'tcx> for UseFactsExtractor<'a, 'tcx> {
 pub(super) fn populate_access_facts<'a, 'tcx>(
     typeck: &mut TypeChecker<'a, 'tcx>,
     body: &Body<'tcx>,
-    location_table: &LocationTable,
     move_data: &MoveData<'tcx>,
-    //FIXME: this is not mutated, but expected to be modified as
-    // out param, bug?
-    dropped_at: &mut Vec<(Local, Location)>,
 ) {
     debug!("populate_access_facts()");
+    let location_table = typeck.borrowck_context.location_table;
 
     if let Some(facts) = typeck.borrowck_context.all_facts.as_mut() {
         let mut extractor = UseFactsExtractor {
@@ -104,10 +101,6 @@ pub(super) fn populate_access_facts<'a, 'tcx>(
         };
         extractor.visit_body(body);
 
-        facts.var_dropped_at.extend(
-            dropped_at.iter().map(|&(local, location)| (local, location_table.mid_index(location))),
-        );
-
         for (local, local_decl) in body.local_decls.iter_enumerated() {
             debug!(
                 "add use_of_var_derefs_origin facts - local={:?}, type={:?}",

compiler/rustc_borrowck/src/type_check/liveness/trace.rs

@@ -16,6 +16,7 @@ use rustc_mir_dataflow::impls::MaybeInitializedPlaces;
 use rustc_mir_dataflow::move_paths::{HasMoveData, MoveData, MovePathIndex};
 use rustc_mir_dataflow::ResultsCursor;
 
+use crate::location::RichLocation;
 use crate::{
     region_infer::values::{self, LiveLoans},
     type_check::liveness::local_use_map::LocalUseMap,
@@ -46,7 +47,6 @@ pub(super) fn trace<'mir, 'tcx>(
     move_data: &MoveData<'tcx>,
     relevant_live_locals: Vec<Local>,
     boring_locals: Vec<Local>,
-    polonius_drop_used: Option<Vec<(Local, Location)>>,
 ) {
     let local_use_map = &LocalUseMap::build(&relevant_live_locals, elements, body);
 
@@ -93,9 +93,7 @@ pub(super) fn trace<'mir, 'tcx>(
 
     let mut results = LivenessResults::new(cx);
 
-    if let Some(drop_used) = polonius_drop_used {
+    results.add_extra_drop_facts(&relevant_live_locals);
-        results.add_extra_drop_facts(drop_used, relevant_live_locals.iter().copied().collect())
-    }
 
     results.compute_for_all_locals(relevant_live_locals);
 
@@ -218,21 +216,38 @@ impl<'me, 'typeck, 'flow, 'tcx> LivenessResults<'me, 'typeck, 'flow, 'tcx> {
     ///
     /// Add facts for all locals with free regions, since regions may outlive
     /// the function body only at certain nodes in the CFG.
-    fn add_extra_drop_facts(
+    fn add_extra_drop_facts(&mut self, relevant_live_locals: &[Local]) -> Option<()> {
-        &mut self,
+        let drop_used = self
-        drop_used: Vec<(Local, Location)>,
+            .cx
-        relevant_live_locals: FxIndexSet<Local>,
+            .typeck
-    ) {
+            .borrowck_context
+            .all_facts
+            .as_ref()
+            .map(|facts| facts.var_dropped_at.clone())?;
+
+        let relevant_live_locals: FxIndexSet<_> = relevant_live_locals.iter().copied().collect();
+
         let locations = IntervalSet::new(self.cx.elements.num_points());
 
-        for (local, location) in drop_used {
+        for (local, location_index) in drop_used {
             if !relevant_live_locals.contains(&local) {
                 let local_ty = self.cx.body.local_decls[local].ty;
                 if local_ty.has_free_regions() {
+                    let location = match self
+                        .cx
+                        .typeck
+                        .borrowck_context
+                        .location_table
+                        .to_location(location_index)
+                    {
+                        RichLocation::Start(l) => l,
+                        RichLocation::Mid(l) => l,
+                    };
                     self.cx.add_drop_live_facts_for(local, local_ty, &[location], &locations);
                 }
             }
         }
+        Some(())
     }
 
     /// Clear the value of fields that are "per local variable".

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -188,15 +188,7 @@ pub(crate) fn type_check<'mir, 'tcx>(
     checker.equate_inputs_and_outputs(body, universal_regions, &normalized_inputs_and_output);
     checker.check_signature_annotation(body);
 
-    liveness::generate(
+    liveness::generate(&mut checker, body, elements, flow_inits, move_data, use_polonius);
-        &mut checker,
-        body,
-        elements,
-        flow_inits,
-        move_data,
-        location_table,
-        use_polonius,
-    );
 
     translate_outlives_facts(&mut checker);
     let opaque_type_values = infcx.take_opaque_types();

compiler/rustc_data_structures/src/graph/dominators/mod.rs

@@ -93,7 +93,7 @@ fn dominators_impl<G: ControlFlowGraph>(graph: &G) -> Inner<G::Node> {
     // These are all done here rather than through one of the 'standard'
     // graph traversals to help make this fast.
     'recurse: while let Some(frame) = stack.last_mut() {
-        while let Some(successor) = frame.iter.next() {
+        for successor in frame.iter.by_ref() {
             if real_to_pre_order[successor].is_none() {
                 let pre_order_idx = pre_order_to_real.push(successor);
                 real_to_pre_order[successor] = Some(pre_order_idx);

compiler/rustc_data_structures/src/graph/iterate/mod.rs

@@ -48,7 +48,7 @@ fn post_order_walk<G: DirectedGraph + Successors>(
         let node = frame.node;
         visited[node] = true;
 
-        while let Some(successor) = frame.iter.next() {
+        for successor in frame.iter.by_ref() {
             if !visited[successor] {
                 stack.push(PostOrderFrame { node: successor, iter: graph.successors(successor) });
                 continue 'recurse;
@@ -112,7 +112,7 @@ where
     /// This is equivalent to just invoke `next` repeatedly until
     /// you get a `None` result.
     pub fn complete_search(&mut self) {
-        while let Some(_) = self.next() {}
+        for _ in self.by_ref() {}
     }
 
     /// Returns true if node has been visited thus far.

compiler/rustc_data_structures/src/graph/scc/mod.rs

@@ -40,7 +40,7 @@ pub struct SccData<S: Idx> {
 }
 
 impl<N: Idx, S: Idx + Ord> Sccs<N, S> {
-    pub fn new(graph: &(impl DirectedGraph<Node = N> + Successors)) -> Self {
+    pub fn new(graph: &impl Successors<Node = N>) -> Self {
         SccsConstruction::construct(graph)
     }
 

compiler/rustc_data_structures/src/profiling.rs

@@ -562,7 +562,7 @@ impl SelfProfiler {
         // ASLR is disabled and the heap is otherwise deterministic.
         let pid: u32 = process::id();
         let filename = format!("{crate_name}-{pid:07}.rustc_profile");
-        let path = output_directory.join(&filename);
+        let path = output_directory.join(filename);
         let profiler =
             Profiler::with_counter(&path, measureme::counters::Counter::by_name(counter_name)?)?;
 

compiler/rustc_data_structures/src/sorted_map.rs

@@ -125,13 +125,13 @@ impl<K: Ord, V> SortedMap<K, V> {
 
     /// Iterate over the keys, sorted
     #[inline]
-    pub fn keys(&self) -> impl Iterator<Item = &K> + ExactSizeIterator + DoubleEndedIterator {
+    pub fn keys(&self) -> impl ExactSizeIterator<Item = &K> + DoubleEndedIterator {
         self.data.iter().map(|(k, _)| k)
     }
 
     /// Iterate over values, sorted by key
     #[inline]
-    pub fn values(&self) -> impl Iterator<Item = &V> + ExactSizeIterator + DoubleEndedIterator {
+    pub fn values(&self) -> impl ExactSizeIterator<Item = &V> + DoubleEndedIterator {
         self.data.iter().map(|(_, v)| v)
     }
 

compiler/rustc_data_structures/src/sync/lock.rs

@@ -69,7 +69,7 @@ mod maybe_sync {
             match self.mode {
                 Mode::NoSync => {
                     let cell = unsafe { &self.lock.mode_union.no_sync };
-                    debug_assert_eq!(cell.get(), true);
+                    debug_assert!(cell.get());
                     cell.set(false);
                 }
                 // SAFETY (unlock): We know that the lock is locked as this type is a proof of that.

compiler/rustc_hir_typeck/src/writeback.rs

@@ -865,6 +865,7 @@ impl<'cx, 'tcx> TypeFolder<TyCtxt<'tcx>> for Resolver<'cx, 'tcx> {
         self.handle_term(ct, ty::Const::outer_exclusive_binder, |tcx, guar| {
             ty::Const::new_error(tcx, guar, ct.ty())
         })
+        .super_fold_with(self)
     }
 
     fn fold_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> ty::Predicate<'tcx> {

compiler/rustc_mir_build/src/build/coverageinfo.rs

@@ -157,6 +157,63 @@ impl BranchInfoBuilder {
 }
 
 impl<'tcx> Builder<'_, 'tcx> {
+    /// If condition coverage is enabled, inject extra blocks and marker statements
+    /// that will let us track the value of the condition in `place`.
+    pub(crate) fn visit_coverage_standalone_condition(
+        &mut self,
+        mut expr_id: ExprId,     // Expression giving the span of the condition
+        place: mir::Place<'tcx>, // Already holds the boolean condition value
+        block: &mut BasicBlock,
+    ) {
+        // Bail out if condition coverage is not enabled for this function.
+        let Some(branch_info) = self.coverage_branch_info.as_mut() else { return };
+        if !self.tcx.sess.instrument_coverage_condition() {
+            return;
+        };
+
+        // Remove any wrappers, so that we can inspect the real underlying expression.
+        while let ExprKind::Use { source: inner } | ExprKind::Scope { value: inner, .. } =
+            self.thir[expr_id].kind
+        {
+            expr_id = inner;
+        }
+        // If the expression is a lazy logical op, it will naturally get branch
+        // coverage as part of its normal lowering, so we can disregard it here.
+        if let ExprKind::LogicalOp { .. } = self.thir[expr_id].kind {
+            return;
+        }
+
+        let source_info = SourceInfo { span: self.thir[expr_id].span, scope: self.source_scope };
+
+        // Using the boolean value that has already been stored in `place`, set up
+        // control flow in the shape of a diamond, so that we can place separate
+        // marker statements in the true and false blocks. The coverage MIR pass
+        // will use those markers to inject coverage counters as appropriate.
+        //
+        //          block
+        //         /     \
+        // true_block   false_block
+        //  (marker)     (marker)
+        //         \     /
+        //        join_block
+
+        let true_block = self.cfg.start_new_block();
+        let false_block = self.cfg.start_new_block();
+        self.cfg.terminate(
+            *block,
+            source_info,
+            mir::TerminatorKind::if_(mir::Operand::Copy(place), true_block, false_block),
+        );
+
+        branch_info.add_two_way_branch(&mut self.cfg, source_info, true_block, false_block);
+
+        let join_block = self.cfg.start_new_block();
+        self.cfg.goto(true_block, source_info, join_block);
+        self.cfg.goto(false_block, source_info, join_block);
+        // Any subsequent codegen in the caller should use the new join block.
+        *block = join_block;
+    }
+
     /// If branch coverage is enabled, inject marker statements into `then_block`
     /// and `else_block`, and record their IDs in the table of branch spans.
     pub(crate) fn visit_coverage_branch_condition(

compiler/rustc_mir_build/src/build/expr/into.rs

@@ -183,9 +183,13 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                         const_: Const::from_bool(this.tcx, constant),
                     },
                 );
-                let rhs = unpack!(this.expr_into_dest(destination, continuation, rhs));
+                let mut rhs_block = unpack!(this.expr_into_dest(destination, continuation, rhs));
+                // Instrument the lowered RHS's value for condition coverage.
+                // (Does nothing if condition coverage is not enabled.)
+                this.visit_coverage_standalone_condition(rhs, destination, &mut rhs_block);
+
                 let target = this.cfg.start_new_block();
-                this.cfg.goto(rhs, source_info, target);
+                this.cfg.goto(rhs_block, source_info, target);
                 this.cfg.goto(short_circuit, source_info, target);
                 target.unit()
             }

compiler/rustc_mir_transform/src/instsimplify.rs

@@ -123,7 +123,7 @@ impl<'tcx> InstSimplifyContext<'tcx, '_> {
 
     /// Transform `&(*a)` ==> `a`.
     fn simplify_ref_deref(&self, source_info: &SourceInfo, rvalue: &mut Rvalue<'tcx>) {
-        if let Rvalue::Ref(_, _, place) = rvalue {
+        if let Rvalue::Ref(_, _, place) | Rvalue::AddressOf(_, place) = rvalue {
             if let Some((base, ProjectionElem::Deref)) = place.as_ref().last_projection() {
                 if rvalue.ty(self.local_decls, self.tcx) != base.ty(self.local_decls, self.tcx).ty {
                     return;

compiler/rustc_parse_format/src/lib.rs

@@ -286,13 +286,11 @@ impl<'a> Iterator for Parser<'a> {
                                     lbrace_byte_pos.to(InnerOffset(rbrace_byte_pos.0 + width)),
                                 );
                             }
-                        } else {
+                        } else if let Some(&(_, maybe)) = self.cur.peek() {
-                            if let Some(&(_, maybe)) = self.cur.peek() {
+                            match maybe {
-                                match maybe {
+                                '?' => self.suggest_format_debug(),
-                                    '?' => self.suggest_format_debug(),
+                                '<' | '^' | '>' => self.suggest_format_align(maybe),
-                                    '<' | '^' | '>' => self.suggest_format_align(maybe),
+                                _ => self.suggest_positional_arg_instead_of_captured_arg(arg),
-                                    _ => self.suggest_positional_arg_instead_of_captured_arg(arg),
-                                }
                             }
                         }
                         Some(NextArgument(Box::new(arg)))
@@ -1028,7 +1026,7 @@ fn find_width_map_from_snippet(
                     if next_c == '{' {
                         // consume up to 6 hexanumeric chars
                         let digits_len =
-                            s.clone().take(6).take_while(|(_, c)| c.is_digit(16)).count();
+                            s.clone().take(6).take_while(|(_, c)| c.is_ascii_hexdigit()).count();
 
                         let len_utf8 = s
                             .as_str()
@@ -1047,14 +1045,14 @@ fn find_width_map_from_snippet(
                         width += required_skips + 2;
 
                         s.nth(digits_len);
-                    } else if next_c.is_digit(16) {
+                    } else if next_c.is_ascii_hexdigit() {
                         width += 1;
 
                         // We suggest adding `{` and `}` when appropriate, accept it here as if
                         // it were correct
                         let mut i = 0; // consume up to 6 hexanumeric chars
                         while let (Some((_, c)), _) = (s.next(), i < 6) {
-                            if c.is_digit(16) {
+                            if c.is_ascii_hexdigit() {
                                 width += 1;
                             } else {
                                 break;

compiler/rustc_serialize/src/serialize.rs

@@ -252,7 +252,7 @@ impl<S: Encoder> Encodable<S> for () {
 }
 
 impl<D: Decoder> Decodable<D> for () {
-    fn decode(_: &mut D) -> () {}
+    fn decode(_: &mut D) {}
 }
 
 impl<S: Encoder, T> Encodable<S> for PhantomData<T> {

compiler/rustc_session/src/config.rs

@@ -159,7 +159,23 @@ pub enum CoverageLevel {
     Block,
     /// Also instrument branch points (includes block coverage).
     Branch,
-    /// Instrument for MC/DC. Mostly a superset of branch coverage, but might
+    /// Same as branch coverage, but also adds branch instrumentation for
+    /// certain boolean expressions that are not directly used for branching.
+    ///
+    /// For example, in the following code, `b` does not directly participate
+    /// in a branch, but condition coverage will instrument it as its own
+    /// artificial branch:
+    /// ```
+    /// # let (a, b) = (false, true);
+    /// let x = a && b;
+    /// //           ^ last operand
+    /// ```
+    ///
+    /// This level is mainly intended to be a stepping-stone towards full MC/DC
+    /// instrumentation, so it might be removed in the future when MC/DC is
+    /// sufficiently complete, or if it is making MC/DC changes difficult.
+    Condition,
+    /// Instrument for MC/DC. Mostly a superset of condition coverage, but might
     /// differ in some corner cases.
     Mcdc,
 }

compiler/rustc_session/src/options.rs

@@ -395,7 +395,7 @@ mod desc {
     pub const parse_optimization_fuel: &str = "crate=integer";
     pub const parse_dump_mono_stats: &str = "`markdown` (default) or `json`";
     pub const parse_instrument_coverage: &str = parse_bool;
-    pub const parse_coverage_options: &str = "`block` | `branch` | `mcdc`";
+    pub const parse_coverage_options: &str = "`block` | `branch` | `condition` | `mcdc`";
     pub const parse_instrument_xray: &str = "either a boolean (`yes`, `no`, `on`, `off`, etc), or a comma separated list of settings: `always` or `never` (mutually exclusive), `ignore-loops`, `instruction-threshold=N`, `skip-entry`, `skip-exit`";
     pub const parse_unpretty: &str = "`string` or `string=string`";
     pub const parse_treat_err_as_bug: &str = "either no value or a non-negative number";
@@ -961,6 +961,7 @@ mod parse {
             match option {
                 "block" => slot.level = CoverageLevel::Block,
                 "branch" => slot.level = CoverageLevel::Branch,
+                "condition" => slot.level = CoverageLevel::Condition,
                 "mcdc" => slot.level = CoverageLevel::Mcdc,
                 _ => return false,
             }

compiler/rustc_session/src/session.rs

@@ -353,6 +353,11 @@ impl Session {
             && self.opts.unstable_opts.coverage_options.level >= CoverageLevel::Branch
     }
 
+    pub fn instrument_coverage_condition(&self) -> bool {
+        self.instrument_coverage()
+            && self.opts.unstable_opts.coverage_options.level >= CoverageLevel::Condition
+    }
+
     pub fn instrument_coverage_mcdc(&self) -> bool {
         self.instrument_coverage()
             && self.opts.unstable_opts.coverage_options.level >= CoverageLevel::Mcdc

compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs

@@ -12,7 +12,6 @@ use rustc_middle::bug;
 use rustc_middle::traits::solve::{
     inspect, CanonicalInput, CanonicalResponse, Certainty, PredefinedOpaquesData, QueryResult,
 };
-use rustc_middle::traits::specialization_graph;
 use rustc_middle::ty::AliasRelationDirection;
 use rustc_middle::ty::TypeFolder;
 use rustc_middle::ty::{
@@ -900,16 +899,6 @@ impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
         args
     }
 
-    pub(super) fn translate_args(
-        &self,
-        param_env: ty::ParamEnv<'tcx>,
-        source_impl: DefId,
-        source_args: ty::GenericArgsRef<'tcx>,
-        target_node: specialization_graph::Node,
-    ) -> ty::GenericArgsRef<'tcx> {
-        crate::traits::translate_args(self.infcx, param_env, source_impl, source_args, target_node)
-    }
-
     pub(super) fn register_ty_outlives(&self, ty: Ty<'tcx>, lt: ty::Region<'tcx>) {
         self.infcx.register_region_obligation_with_cause(ty, lt, &ObligationCause::dummy());
     }

compiler/rustc_trait_selection/src/solve/normalizes_to/mod.rs

@@ -1,4 +1,4 @@
-use crate::traits::specialization_graph;
+use crate::traits::specialization_graph::{self, LeafDef, Node};
 
 use super::assembly::structural_traits::AsyncCallableRelevantTypes;
 use super::assembly::{self, structural_traits, Candidate};
@@ -9,7 +9,6 @@ use rustc_infer::infer::InferCtxt;
 use rustc_infer::traits::query::NoSolution;
 use rustc_infer::traits::solve::inspect::ProbeKind;
 use rustc_infer::traits::solve::MaybeCause;
-use rustc_infer::traits::specialization_graph::LeafDef;
 use rustc_infer::traits::Reveal;
 use rustc_middle::traits::solve::{CandidateSource, Certainty, Goal, QueryResult};
 use rustc_middle::traits::BuiltinImplSource;
@@ -189,8 +188,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
             // In case the associated item is hidden due to specialization, we have to
             // return ambiguity this would otherwise be incomplete, resulting in
             // unsoundness during coherence (#105782).
-            let Some(assoc_def) = fetch_eligible_assoc_item_def(
+            let Some(assoc_def) = ecx.fetch_eligible_assoc_item_def(
-                ecx,
                 goal.param_env,
                 goal_trait_ref,
                 goal.predicate.def_id(),
@@ -235,16 +233,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
             //
             // And then map these args to the args of the defining impl of `Assoc`, going
             // from `[u32, u64]` to `[u32, i32, u64]`.
-            let impl_args_with_gat =
+            let associated_item_args =
-                goal.predicate.alias.args.rebase_onto(tcx, goal_trait_ref.def_id, impl_args);
+                ecx.translate_args(&assoc_def, goal, impl_def_id, impl_args, impl_trait_ref)?;
-            let args = ecx.translate_args(
-                goal.param_env,
-                impl_def_id,
-                impl_args_with_gat,
-                assoc_def.defining_node,
-            );
 
-            if !tcx.check_args_compatible(assoc_def.item.def_id, args) {
+            if !tcx.check_args_compatible(assoc_def.item.def_id, associated_item_args) {
                 return error_response(
                     ecx,
                     "associated item has mismatched generic item arguments",
@@ -272,7 +264,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
                 ty::AssocKind::Fn => unreachable!("we should never project to a fn"),
             };
 
-            ecx.instantiate_normalizes_to_term(goal, term.instantiate(tcx, args));
+            ecx.instantiate_normalizes_to_term(goal, term.instantiate(tcx, associated_item_args));
             ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
         })
     }
@@ -889,38 +881,79 @@ impl<'tcx> assembly::GoalKind<'tcx> for NormalizesTo<'tcx> {
     }
 }
 
-/// This behavior is also implemented in `rustc_ty_utils` and in the old `project` code.
+impl<'tcx> EvalCtxt<'_, InferCtxt<'tcx>> {
-///
+    fn translate_args(
-/// FIXME: We should merge these 3 implementations as it's likely that they otherwise
+        &mut self,
-/// diverge.
+        assoc_def: &LeafDef,
-#[instrument(level = "trace", skip(ecx, param_env), ret)]
+        goal: Goal<'tcx, ty::NormalizesTo<'tcx>>,
-fn fetch_eligible_assoc_item_def<'tcx>(
+        impl_def_id: DefId,
-    ecx: &EvalCtxt<'_, InferCtxt<'tcx>>,
+        impl_args: ty::GenericArgsRef<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+        impl_trait_ref: rustc_type_ir::TraitRef<TyCtxt<'tcx>>,
-    goal_trait_ref: ty::TraitRef<'tcx>,
+    ) -> Result<ty::GenericArgsRef<'tcx>, NoSolution> {
-    trait_assoc_def_id: DefId,
+        let tcx = self.interner();
-    impl_def_id: DefId,
+        Ok(match assoc_def.defining_node {
-) -> Result<Option<LeafDef>, NoSolution> {
+            Node::Trait(_) => goal.predicate.alias.args,
-    let node_item =
+            Node::Impl(target_impl_def_id) => {
-        specialization_graph::assoc_def(ecx.interner(), impl_def_id, trait_assoc_def_id)
+                if target_impl_def_id == impl_def_id {
-            .map_err(|ErrorGuaranteed { .. }| NoSolution)?;
+                    // Same impl, no need to fully translate, just a rebase from
+                    // the trait is sufficient.
+                    goal.predicate.alias.args.rebase_onto(tcx, impl_trait_ref.def_id, impl_args)
+                } else {
+                    let target_args = self.fresh_args_for_item(target_impl_def_id);
+                    let target_trait_ref = tcx
+                        .impl_trait_ref(target_impl_def_id)
+                        .unwrap()
+                        .instantiate(tcx, target_args);
+                    // Relate source impl to target impl by equating trait refs.
+                    self.eq(goal.param_env, impl_trait_ref, target_trait_ref)?;
+                    // Also add predicates since they may be needed to constrain the
+                    // target impl's params.
+                    self.add_goals(
+                        GoalSource::Misc,
+                        tcx.predicates_of(target_impl_def_id)
+                            .instantiate(tcx, target_args)
+                            .into_iter()
+                            .map(|(pred, _)| goal.with(tcx, pred)),
+                    );
+                    goal.predicate.alias.args.rebase_onto(tcx, impl_trait_ref.def_id, target_args)
+                }
+            }
+        })
+    }
 
-    let eligible = if node_item.is_final() {
+    /// This behavior is also implemented in `rustc_ty_utils` and in the old `project` code.
-        // Non-specializable items are always projectable.
+    ///
-        true
+    /// FIXME: We should merge these 3 implementations as it's likely that they otherwise
-    } else {
+    /// diverge.
-        // Only reveal a specializable default if we're past type-checking
+    #[instrument(level = "trace", skip(self, param_env), ret)]
-        // and the obligation is monomorphic, otherwise passes such as
+    fn fetch_eligible_assoc_item_def(
-        // transmute checking and polymorphic MIR optimizations could
+        &self,
-        // get a result which isn't correct for all monomorphizations.
+        param_env: ty::ParamEnv<'tcx>,
-        if param_env.reveal() == Reveal::All {
+        goal_trait_ref: ty::TraitRef<'tcx>,
-            let poly_trait_ref = ecx.resolve_vars_if_possible(goal_trait_ref);
+        trait_assoc_def_id: DefId,
-            !poly_trait_ref.still_further_specializable()
+        impl_def_id: DefId,
+    ) -> Result<Option<LeafDef>, NoSolution> {
+        let node_item =
+            specialization_graph::assoc_def(self.interner(), impl_def_id, trait_assoc_def_id)
+                .map_err(|ErrorGuaranteed { .. }| NoSolution)?;
+
+        let eligible = if node_item.is_final() {
+            // Non-specializable items are always projectable.
+            true
         } else {
-            trace!(?node_item.item.def_id, "not eligible due to default");
+            // Only reveal a specializable default if we're past type-checking
-            false
+            // and the obligation is monomorphic, otherwise passes such as
-        }
+            // transmute checking and polymorphic MIR optimizations could
-    };
+            // get a result which isn't correct for all monomorphizations.
+            if param_env.reveal() == Reveal::All {
+                let poly_trait_ref = self.resolve_vars_if_possible(goal_trait_ref);
+                !poly_trait_ref.still_further_specializable()
+            } else {
+                trace!(?node_item.item.def_id, "not eligible due to default");
+                false
+            }
+        };
 
-    if eligible { Ok(Some(node_item)) } else { Ok(None) }
+        if eligible { Ok(Some(node_item)) } else { Ok(None) }
+    }
 }

compiler/stable_mir/src/mir/pretty.rs

@@ -156,7 +156,7 @@ fn pretty_terminator<W: Write>(writer: &mut W, terminator: &TerminatorKind) -> i
 
 fn pretty_terminator_head<W: Write>(writer: &mut W, terminator: &TerminatorKind) -> io::Result<()> {
     use self::TerminatorKind::*;
-    const INDENT: &'static str = "        ";
+    const INDENT: &str = "        ";
     match terminator {
         Goto { .. } => write!(writer, "{INDENT}goto"),
         SwitchInt { discr, .. } => {
@@ -315,7 +315,7 @@ fn pretty_operand(operand: &Operand) -> String {
 }
 
 fn pretty_const(literal: &Const) -> String {
-    with(|cx| cx.const_pretty(&literal))
+    with(|cx| cx.const_pretty(literal))
 }
 
 fn pretty_rvalue<W: Write>(writer: &mut W, rval: &Rvalue) -> io::Result<()> {

compiler/stable_mir/src/ty.rs

@@ -526,7 +526,7 @@ pub enum IntTy {
 impl IntTy {
     pub fn num_bytes(self) -> usize {
         match self {
-            IntTy::Isize => crate::target::MachineInfo::target_pointer_width().bytes().into(),
+            IntTy::Isize => crate::target::MachineInfo::target_pointer_width().bytes(),
             IntTy::I8 => 1,
             IntTy::I16 => 2,
             IntTy::I32 => 4,
@@ -549,7 +549,7 @@ pub enum UintTy {
 impl UintTy {
     pub fn num_bytes(self) -> usize {
         match self {
-            UintTy::Usize => crate::target::MachineInfo::target_pointer_width().bytes().into(),
+            UintTy::Usize => crate::target::MachineInfo::target_pointer_width().bytes(),
             UintTy::U8 => 1,
             UintTy::U16 => 2,
             UintTy::U32 => 4,
@@ -1185,7 +1185,7 @@ impl Allocation {
         match self.read_int()? {
             0 => Ok(false),
             1 => Ok(true),
-            val @ _ => Err(error!("Unexpected value for bool: `{val}`")),
+            val => Err(error!("Unexpected value for bool: `{val}`")),
         }
     }
 

library/proc_macro/src/bridge/fxhash.rs

@@ -69,7 +69,7 @@ impl Hasher for FxHasher {
             hash.add_to_hash(u16::from_ne_bytes(bytes[..2].try_into().unwrap()) as usize);
             bytes = &bytes[2..];
         }
-        if (size_of::<usize>() > 1) && bytes.len() >= 1 {
+        if (size_of::<usize>() > 1) && !bytes.is_empty() {
             hash.add_to_hash(bytes[0] as usize);
         }
         self.hash = hash.hash;

library/proc_macro/src/bridge/rpc.rs

@@ -264,9 +264,9 @@ impl From<Box<dyn Any + Send>> for PanicMessage {
     }
 }
 
-impl Into<Box<dyn Any + Send>> for PanicMessage {
+impl From<PanicMessage> for Box<dyn Any + Send> {
-    fn into(self) -> Box<dyn Any + Send> {
+    fn from(val: PanicMessage) -> Self {
-        match self {
+        match val {
             PanicMessage::StaticStr(s) => Box::new(s),
             PanicMessage::String(s) => Box::new(s),
             PanicMessage::Unknown => {

library/test/src/cli.rs

@@ -200,7 +200,7 @@ Test Attributes:
 pub fn parse_opts(args: &[String]) -> Option<OptRes> {
     // Parse matches.
     let opts = optgroups();
-    let binary = args.get(0).map(|c| &**c).unwrap_or("...");
+    let binary = args.first().map(|c| &**c).unwrap_or("...");
     let args = args.get(1..).unwrap_or(args);
     let matches = match opts.parse(args) {
         Ok(m) => m,

library/test/src/term/terminfo/parm.rs

@@ -524,7 +524,7 @@ fn format(val: Param, op: FormatOp, flags: Flags) -> Result<Vec<u8>, String> {
         } else {
             let mut s_ = Vec::with_capacity(flags.width);
             s_.extend(repeat(b' ').take(n));
-            s_.extend(s.into_iter());
+            s_.extend(s);
             s = s_;
         }
     }

src/bootstrap/src/core/build_steps/test.rs

@@ -1781,25 +1781,11 @@ NOTE: if you're sure you want to do this, please open an issue as to why. In the
                 .arg(builder.ensure(tool::JsonDocLint { compiler: json_compiler, target }));
         }
 
-        if mode == "coverage-map" {
+        if matches!(mode, "coverage-map" | "coverage-run") {
-            let coverage_dump = builder.ensure(tool::CoverageDump {
+            let coverage_dump = builder.tool_exe(Tool::CoverageDump);
-                compiler: compiler.with_stage(0),
-                target: compiler.host,
-            });
             cmd.arg("--coverage-dump-path").arg(coverage_dump);
         }
 
-        if mode == "coverage-run" {
-            // The demangler doesn't need the current compiler, so we can avoid
-            // unnecessary rebuilds by using the bootstrap compiler instead.
-            let rust_demangler = builder.ensure(tool::RustDemangler {
-                compiler: compiler.with_stage(0),
-                target: compiler.host,
-                extra_features: Vec::new(),
-            });
-            cmd.arg("--rust-demangler-path").arg(rust_demangler);
-        }
-
         cmd.arg("--src-base").arg(builder.src.join("tests").join(suite));
         cmd.arg("--build-base").arg(testdir(builder, compiler.host).join(suite));
 

src/doc/unstable-book/src/compiler-flags/coverage-options.md

@@ -5,13 +5,16 @@ This option controls details of the coverage instrumentation performed by
 
 Multiple options can be passed, separated by commas. Valid options are:
 
-- `block`, `branch`, `mcdc`:
+- `block`, `branch`, `condition`, `mcdc`:
   Sets the level of coverage instrumentation.
   Setting the level will override any previously-specified level.
   - `block` (default):
     Blocks in the control-flow graph will be instrumented for coverage.
   - `branch`:
     In addition to block coverage, also enables branch coverage instrumentation.
+  - `condition`:
+    In addition to branch coverage, also instruments some boolean expressions
+    as branches, even if they are not directly used as branch conditions.
   - `mcdc`:
-    In addition to block and branch coverage, also enables MC/DC instrumentation.
+    In addition to condition coverage, also enables MC/DC instrumentation.
     (Branch coverage instrumentation may differ in some cases.)

src/tools/compiletest/src/common.rs

@@ -187,9 +187,6 @@ pub struct Config {
     /// The rustdoc executable.
     pub rustdoc_path: Option<PathBuf>,
 
-    /// The rust-demangler executable.
-    pub rust_demangler_path: Option<PathBuf>,
-
     /// The coverage-dump executable.
     pub coverage_dump_path: Option<PathBuf>,
 

src/tools/compiletest/src/lib.rs

@@ -46,7 +46,6 @@ pub fn parse_config(args: Vec<String>) -> Config {
         .reqopt("", "run-lib-path", "path to target shared libraries", "PATH")
         .reqopt("", "rustc-path", "path to rustc to use for compiling", "PATH")
         .optopt("", "rustdoc-path", "path to rustdoc to use for compiling", "PATH")
-        .optopt("", "rust-demangler-path", "path to rust-demangler to use in tests", "PATH")
         .optopt("", "coverage-dump-path", "path to coverage-dump to use in tests", "PATH")
         .reqopt("", "python", "path to python to use for doc tests", "PATH")
         .optopt("", "jsondocck-path", "path to jsondocck to use for doc tests", "PATH")
@@ -232,7 +231,6 @@ pub fn parse_config(args: Vec<String>) -> Config {
         run_lib_path: make_absolute(opt_path(matches, "run-lib-path")),
         rustc_path: opt_path(matches, "rustc-path"),
         rustdoc_path: matches.opt_str("rustdoc-path").map(PathBuf::from),
-        rust_demangler_path: matches.opt_str("rust-demangler-path").map(PathBuf::from),
         coverage_dump_path: matches.opt_str("coverage-dump-path").map(PathBuf::from),
         python: matches.opt_str("python").unwrap(),
         jsondocck_path: matches.opt_str("jsondocck-path"),
@@ -337,7 +335,6 @@ pub fn log_config(config: &Config) {
     logv(c, format!("run_lib_path: {:?}", config.run_lib_path));
     logv(c, format!("rustc_path: {:?}", config.rustc_path.display()));
     logv(c, format!("rustdoc_path: {:?}", config.rustdoc_path));
-    logv(c, format!("rust_demangler_path: {:?}", config.rust_demangler_path));
     logv(c, format!("src_base: {:?}", config.src_base.display()));
     logv(c, format!("build_base: {:?}", config.build_base.display()));
     logv(c, format!("stage_id: {}", config.stage_id));

src/tools/compiletest/src/runtest.rs

@@ -3561,10 +3561,6 @@ impl<'test> TestCx<'test> {
             cmd.env("RUSTDOC", cwd.join(rustdoc));
         }
 
-        if let Some(ref rust_demangler) = self.config.rust_demangler_path {
-            cmd.env("RUST_DEMANGLER", cwd.join(rust_demangler));
-        }
-
         if let Some(ref node) = self.config.nodejs {
             cmd.env("NODE", node);
         }

src/tools/compiletest/src/runtest/coverage.rs

@@ -10,10 +10,15 @@ use crate::common::{UI_COVERAGE, UI_COVERAGE_MAP};
 use crate::runtest::{static_regex, Emit, ProcRes, TestCx, WillExecute};
 
 impl<'test> TestCx<'test> {
+    fn coverage_dump_path(&self) -> &Path {
+        self.config
+            .coverage_dump_path
+            .as_deref()
+            .unwrap_or_else(|| self.fatal("missing --coverage-dump"))
+    }
+
     pub(crate) fn run_coverage_map_test(&self) {
-        let Some(coverage_dump_path) = &self.config.coverage_dump_path else {
+        let coverage_dump_path = self.coverage_dump_path();
-            self.fatal("missing --coverage-dump");
-        };
 
         let (proc_res, llvm_ir_path) = self.compile_test_and_save_ir();
         if !proc_res.status.success() {
@@ -102,8 +107,10 @@ impl<'test> TestCx<'test> {
         let proc_res = self.run_llvm_tool("llvm-cov", |cmd| {
             cmd.args(["show", "--format=text", "--show-line-counts-or-regions"]);
 
-            cmd.arg("--Xdemangler");
+            // Specify the demangler binary and its arguments.
-            cmd.arg(self.config.rust_demangler_path.as_ref().unwrap());
+            let coverage_dump_path = self.coverage_dump_path();
+            cmd.arg("--Xdemangler").arg(coverage_dump_path);
+            cmd.arg("--Xdemangler").arg("--demangle");
 
             cmd.arg("--instr-profile");
             cmd.arg(&profdata_path);

src/tools/coverage-dump/README.md

@@ -6,3 +6,8 @@ The output format is mostly arbitrary, so it's OK to change the output as long
 as any affected tests are also re-blessed. However, the output should be
 consistent across different executions on different platforms, so avoid
 printing any information that is platform-specific or non-deterministic.
+
+## Demangle mode
+
+When run as `coverage-dump --demangle`, this tool instead functions as a
+command-line demangler that can be invoked by `llvm-cov`.

src/tools/coverage-dump/src/main.rs

@@ -7,6 +7,13 @@ fn main() -> anyhow::Result<()> {
 
     let args = std::env::args().collect::<Vec<_>>();
 
+    // The coverage-dump tool already needs `rustc_demangle` in order to read
+    // coverage metadata, so it's very easy to also have a separate mode that
+    // turns it into a command-line demangler for use by coverage-run tests.
+    if &args[1..] == &["--demangle"] {
+        return demangle();
+    }
+
     let llvm_ir_path = args.get(1).context("LLVM IR file not specified")?;
     let llvm_ir = std::fs::read_to_string(llvm_ir_path).context("couldn't read LLVM IR file")?;
 
@@ -15,3 +22,15 @@ fn main() -> anyhow::Result<()> {
 
     Ok(())
 }
+
+fn demangle() -> anyhow::Result<()> {
+    use std::fmt::Write as _;
+
+    let stdin = std::io::read_to_string(std::io::stdin())?;
+    let mut output = String::with_capacity(stdin.len());
+    for line in stdin.lines() {
+        writeln!(output, "{:#}", rustc_demangle::demangle(line))?;
+    }
+    print!("{output}");
+    Ok(())
+}

tests/coverage/condition/conditions.cov-map

@@ -0,0 +1,152 @@
+Function name: conditions::assign_3_and_or
+Raw bytes (69): 0x[01, 01, 07, 07, 11, 09, 0d, 01, 05, 05, 09, 16, 1a, 05, 09, 01, 05, 09, 01, 1c, 01, 00, 2f, 03, 01, 09, 00, 0a, 01, 00, 0d, 00, 0e, 20, 05, 1a, 00, 0d, 00, 0e, 05, 00, 12, 00, 13, 20, 09, 16, 00, 12, 00, 13, 13, 00, 17, 00, 18, 20, 0d, 11, 00, 17, 00, 18, 03, 01, 05, 01, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 7
+- expression 0 operands: lhs = Expression(1, Add), rhs = Counter(4)
+- expression 1 operands: lhs = Counter(2), rhs = Counter(3)
+- expression 2 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 3 operands: lhs = Counter(1), rhs = Counter(2)
+- expression 4 operands: lhs = Expression(5, Sub), rhs = Expression(6, Sub)
+- expression 5 operands: lhs = Counter(1), rhs = Counter(2)
+- expression 6 operands: lhs = Counter(0), rhs = Counter(1)
+Number of file 0 mappings: 9
+- Code(Counter(0)) at (prev + 28, 1) to (start + 0, 47)
+- Code(Expression(0, Add)) at (prev + 1, 9) to (start + 0, 10)
+    = ((c2 + c3) + c4)
+- Code(Counter(0)) at (prev + 0, 13) to (start + 0, 14)
+- Branch { true: Counter(1), false: Expression(6, Sub) } at (prev + 0, 13) to (start + 0, 14)
+    true  = c1
+    false = (c0 - c1)
+- Code(Counter(1)) at (prev + 0, 18) to (start + 0, 19)
+- Branch { true: Counter(2), false: Expression(5, Sub) } at (prev + 0, 18) to (start + 0, 19)
+    true  = c2
+    false = (c1 - c2)
+- Code(Expression(4, Add)) at (prev + 0, 23) to (start + 0, 24)
+    = ((c1 - c2) + (c0 - c1))
+- Branch { true: Counter(3), false: Counter(4) } at (prev + 0, 23) to (start + 0, 24)
+    true  = c3
+    false = c4
+- Code(Expression(0, Add)) at (prev + 1, 5) to (start + 1, 2)
+    = ((c2 + c3) + c4)
+
+Function name: conditions::assign_3_or_and
+Raw bytes (73): 0x[01, 01, 09, 05, 07, 0b, 11, 09, 0d, 01, 05, 01, 05, 22, 11, 01, 05, 22, 11, 01, 05, 09, 01, 17, 01, 00, 2f, 03, 01, 09, 00, 0a, 01, 00, 0d, 00, 0e, 20, 05, 22, 00, 0d, 00, 0e, 22, 00, 12, 00, 13, 20, 1e, 11, 00, 12, 00, 13, 1e, 00, 17, 00, 18, 20, 09, 0d, 00, 17, 00, 18, 03, 01, 05, 01, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 9
+- expression 0 operands: lhs = Counter(1), rhs = Expression(1, Add)
+- expression 1 operands: lhs = Expression(2, Add), rhs = Counter(4)
+- expression 2 operands: lhs = Counter(2), rhs = Counter(3)
+- expression 3 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 4 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 5 operands: lhs = Expression(8, Sub), rhs = Counter(4)
+- expression 6 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 7 operands: lhs = Expression(8, Sub), rhs = Counter(4)
+- expression 8 operands: lhs = Counter(0), rhs = Counter(1)
+Number of file 0 mappings: 9
+- Code(Counter(0)) at (prev + 23, 1) to (start + 0, 47)
+- Code(Expression(0, Add)) at (prev + 1, 9) to (start + 0, 10)
+    = (c1 + ((c2 + c3) + c4))
+- Code(Counter(0)) at (prev + 0, 13) to (start + 0, 14)
+- Branch { true: Counter(1), false: Expression(8, Sub) } at (prev + 0, 13) to (start + 0, 14)
+    true  = c1
+    false = (c0 - c1)
+- Code(Expression(8, Sub)) at (prev + 0, 18) to (start + 0, 19)
+    = (c0 - c1)
+- Branch { true: Expression(7, Sub), false: Counter(4) } at (prev + 0, 18) to (start + 0, 19)
+    true  = ((c0 - c1) - c4)
+    false = c4
+- Code(Expression(7, Sub)) at (prev + 0, 23) to (start + 0, 24)
+    = ((c0 - c1) - c4)
+- Branch { true: Counter(2), false: Counter(3) } at (prev + 0, 23) to (start + 0, 24)
+    true  = c2
+    false = c3
+- Code(Expression(0, Add)) at (prev + 1, 5) to (start + 1, 2)
+    = (c1 + ((c2 + c3) + c4))
+
+Function name: conditions::assign_and
+Raw bytes (51): 0x[01, 01, 04, 07, 0e, 09, 0d, 01, 05, 01, 05, 07, 01, 0d, 01, 00, 21, 03, 01, 09, 00, 0a, 01, 00, 0d, 00, 0e, 20, 05, 0e, 00, 0d, 00, 0e, 05, 00, 12, 00, 13, 20, 09, 0d, 00, 12, 00, 13, 03, 01, 05, 01, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 4
+- expression 0 operands: lhs = Expression(1, Add), rhs = Expression(3, Sub)
+- expression 1 operands: lhs = Counter(2), rhs = Counter(3)
+- expression 2 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 3 operands: lhs = Counter(0), rhs = Counter(1)
+Number of file 0 mappings: 7
+- Code(Counter(0)) at (prev + 13, 1) to (start + 0, 33)
+- Code(Expression(0, Add)) at (prev + 1, 9) to (start + 0, 10)
+    = ((c2 + c3) + (c0 - c1))
+- Code(Counter(0)) at (prev + 0, 13) to (start + 0, 14)
+- Branch { true: Counter(1), false: Expression(3, Sub) } at (prev + 0, 13) to (start + 0, 14)
+    true  = c1
+    false = (c0 - c1)
+- Code(Counter(1)) at (prev + 0, 18) to (start + 0, 19)
+- Branch { true: Counter(2), false: Counter(3) } at (prev + 0, 18) to (start + 0, 19)
+    true  = c2
+    false = c3
+- Code(Expression(0, Add)) at (prev + 1, 5) to (start + 1, 2)
+    = ((c2 + c3) + (c0 - c1))
+
+Function name: conditions::assign_or
+Raw bytes (51): 0x[01, 01, 04, 07, 0d, 05, 09, 01, 05, 01, 05, 07, 01, 12, 01, 00, 20, 03, 01, 09, 00, 0a, 01, 00, 0d, 00, 0e, 20, 05, 0e, 00, 0d, 00, 0e, 0e, 00, 12, 00, 13, 20, 09, 0d, 00, 12, 00, 13, 03, 01, 05, 01, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 4
+- expression 0 operands: lhs = Expression(1, Add), rhs = Counter(3)
+- expression 1 operands: lhs = Counter(1), rhs = Counter(2)
+- expression 2 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 3 operands: lhs = Counter(0), rhs = Counter(1)
+Number of file 0 mappings: 7
+- Code(Counter(0)) at (prev + 18, 1) to (start + 0, 32)
+- Code(Expression(0, Add)) at (prev + 1, 9) to (start + 0, 10)
+    = ((c1 + c2) + c3)
+- Code(Counter(0)) at (prev + 0, 13) to (start + 0, 14)
+- Branch { true: Counter(1), false: Expression(3, Sub) } at (prev + 0, 13) to (start + 0, 14)
+    true  = c1
+    false = (c0 - c1)
+- Code(Expression(3, Sub)) at (prev + 0, 18) to (start + 0, 19)
+    = (c0 - c1)
+- Branch { true: Counter(2), false: Counter(3) } at (prev + 0, 18) to (start + 0, 19)
+    true  = c2
+    false = c3
+- Code(Expression(0, Add)) at (prev + 1, 5) to (start + 1, 2)
+    = ((c1 + c2) + c3)
+
+Function name: conditions::foo
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 21, 01, 02, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 0
+Number of file 0 mappings: 1
+- Code(Counter(0)) at (prev + 33, 1) to (start + 2, 2)
+
+Function name: conditions::func_call
+Raw bytes (39): 0x[01, 01, 03, 01, 05, 0b, 02, 09, 0d, 05, 01, 25, 01, 01, 0a, 20, 05, 02, 01, 09, 00, 0a, 05, 00, 0e, 00, 0f, 20, 09, 0d, 00, 0e, 00, 0f, 07, 01, 01, 00, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 3
+- expression 0 operands: lhs = Counter(0), rhs = Counter(1)
+- expression 1 operands: lhs = Expression(2, Add), rhs = Expression(0, Sub)
+- expression 2 operands: lhs = Counter(2), rhs = Counter(3)
+Number of file 0 mappings: 5
+- Code(Counter(0)) at (prev + 37, 1) to (start + 1, 10)
+- Branch { true: Counter(1), false: Expression(0, Sub) } at (prev + 1, 9) to (start + 0, 10)
+    true  = c1
+    false = (c0 - c1)
+- Code(Counter(1)) at (prev + 0, 14) to (start + 0, 15)
+- Branch { true: Counter(2), false: Counter(3) } at (prev + 0, 14) to (start + 0, 15)
+    true  = c2
+    false = c3
+- Code(Expression(1, Add)) at (prev + 1, 1) to (start + 0, 2)
+    = ((c2 + c3) + (c0 - c1))
+
+Function name: conditions::simple_assign
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 08, 01, 03, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 0
+Number of file 0 mappings: 1
+- Code(Counter(0)) at (prev + 8, 1) to (start + 3, 2)
+

tests/coverage/condition/conditions.coverage

@@ -0,0 +1,95 @@
+   LL|       |#![feature(coverage_attribute)]
+   LL|       |//@ edition: 2021
+   LL|       |//@ compile-flags: -Zcoverage-options=condition
+   LL|       |//@ llvm-cov-flags: --show-branches=count
+   LL|       |
+   LL|       |use core::hint::black_box;
+   LL|       |
+   LL|      2|fn simple_assign(a: bool) {
+   LL|      2|    let x = a;
+   LL|      2|    black_box(x);
+   LL|      2|}
+   LL|       |
+   LL|      3|fn assign_and(a: bool, b: bool) {
+   LL|      3|    let x = a && b;
+                               ^2
+  ------------------
+  |  Branch (LL:13): [True: 2, False: 1]
+  |  Branch (LL:18): [True: 1, False: 1]
+  ------------------
+   LL|      3|    black_box(x);
+   LL|      3|}
+   LL|       |
+   LL|      3|fn assign_or(a: bool, b: bool) {
+   LL|      3|    let x = a || b;
+                               ^1
+  ------------------
+  |  Branch (LL:13): [True: 2, False: 1]
+  |  Branch (LL:18): [True: 0, False: 1]
+  ------------------
+   LL|      3|    black_box(x);
+   LL|      3|}
+   LL|       |
+   LL|      4|fn assign_3_or_and(a: bool, b: bool, c: bool) {
+   LL|      4|    let x = a || b && c;
+                               ^2   ^1
+  ------------------
+  |  Branch (LL:13): [True: 2, False: 2]
+  |  Branch (LL:18): [True: 1, False: 1]
+  |  Branch (LL:23): [True: 1, False: 0]
+  ------------------
+   LL|      4|    black_box(x);
+   LL|      4|}
+   LL|       |
+   LL|      4|fn assign_3_and_or(a: bool, b: bool, c: bool) {
+   LL|      4|    let x = a && b || c;
+                               ^2   ^3
+  ------------------
+  |  Branch (LL:13): [True: 2, False: 2]
+  |  Branch (LL:18): [True: 1, False: 1]
+  |  Branch (LL:23): [True: 2, False: 1]
+  ------------------
+   LL|      4|    black_box(x);
+   LL|      4|}
+   LL|       |
+   LL|      3|fn foo(a: bool) -> bool {
+   LL|      3|    black_box(a)
+   LL|      3|}
+   LL|       |
+   LL|      3|fn func_call(a: bool, b: bool) {
+   LL|      3|    foo(a && b);
+                           ^2
+  ------------------
+  |  Branch (LL:9): [True: 2, False: 1]
+  |  Branch (LL:14): [True: 1, False: 1]
+  ------------------
+   LL|      3|}
+   LL|       |
+   LL|       |#[coverage(off)]
+   LL|       |fn main() {
+   LL|       |    simple_assign(true);
+   LL|       |    simple_assign(false);
+   LL|       |
+   LL|       |    assign_and(true, false);
+   LL|       |    assign_and(true, true);
+   LL|       |    assign_and(false, false);
+   LL|       |
+   LL|       |    assign_or(true, false);
+   LL|       |    assign_or(true, true);
+   LL|       |    assign_or(false, false);
+   LL|       |
+   LL|       |    assign_3_or_and(true, false, false);
+   LL|       |    assign_3_or_and(true, true, false);
+   LL|       |    assign_3_or_and(false, false, true);
+   LL|       |    assign_3_or_and(false, true, true);
+   LL|       |
+   LL|       |    assign_3_and_or(true, false, false);
+   LL|       |    assign_3_and_or(true, true, false);
+   LL|       |    assign_3_and_or(false, false, true);
+   LL|       |    assign_3_and_or(false, true, true);
+   LL|       |
+   LL|       |    func_call(true, false);
+   LL|       |    func_call(true, true);
+   LL|       |    func_call(false, false);
+   LL|       |}
+

tests/coverage/condition/conditions.rs

@@ -0,0 +1,67 @@
+#![feature(coverage_attribute)]
+//@ edition: 2021
+//@ compile-flags: -Zcoverage-options=condition
+//@ llvm-cov-flags: --show-branches=count
+
+use core::hint::black_box;
+
+fn simple_assign(a: bool) {
+    let x = a;
+    black_box(x);
+}
+
+fn assign_and(a: bool, b: bool) {
+    let x = a && b;
+    black_box(x);
+}
+
+fn assign_or(a: bool, b: bool) {
+    let x = a || b;
+    black_box(x);
+}
+
+fn assign_3_or_and(a: bool, b: bool, c: bool) {
+    let x = a || b && c;
+    black_box(x);
+}
+
+fn assign_3_and_or(a: bool, b: bool, c: bool) {
+    let x = a && b || c;
+    black_box(x);
+}
+
+fn foo(a: bool) -> bool {
+    black_box(a)
+}
+
+fn func_call(a: bool, b: bool) {
+    foo(a && b);
+}
+
+#[coverage(off)]
+fn main() {
+    simple_assign(true);
+    simple_assign(false);
+
+    assign_and(true, false);
+    assign_and(true, true);
+    assign_and(false, false);
+
+    assign_or(true, false);
+    assign_or(true, true);
+    assign_or(false, false);
+
+    assign_3_or_and(true, false, false);
+    assign_3_or_and(true, true, false);
+    assign_3_or_and(false, false, true);
+    assign_3_or_and(false, true, true);
+
+    assign_3_and_or(true, false, false);
+    assign_3_and_or(true, true, false);
+    assign_3_and_or(false, false, true);
+    assign_3_and_or(false, true, true);
+
+    func_call(true, false);
+    func_call(true, true);
+    func_call(false, false);
+}

tests/mir-opt/instsimplify/ref_of_deref.pointers.InstSimplify.diff

@@ -0,0 +1,58 @@
+- // MIR for `pointers` before InstSimplify
++ // MIR for `pointers` after InstSimplify
+  
+  fn pointers(_1: *const [i32], _2: *mut i32) -> () {
+      debug const_ptr => _1;
+      debug mut_ptr => _2;
+      let mut _0: ();
+      let _3: &[i32];
+      scope 1 {
+          debug _a => _3;
+          let _4: &i32;
+          scope 2 {
+              debug _b => _4;
+              let _5: &mut i32;
+              scope 3 {
+                  debug _c => _5;
+                  let _6: *const [i32];
+                  scope 4 {
+                      debug _d => _6;
+                      let _7: *const i32;
+                      scope 5 {
+                          debug _e => _7;
+                          let _8: *mut i32;
+                          scope 6 {
+                              debug _f => _8;
+                          }
+                      }
+                  }
+              }
+          }
+      }
+  
+      bb0: {
+          StorageLive(_3);
+          _3 = &(*_1);
+          StorageLive(_4);
+          _4 = &(*_2);
+          StorageLive(_5);
+          _5 = &mut (*_2);
+          StorageLive(_6);
+-         _6 = &raw const (*_1);
++         _6 = _1;
+          StorageLive(_7);
+          _7 = &raw const (*_2);
+          StorageLive(_8);
+-         _8 = &raw mut (*_2);
++         _8 = _2;
+          _0 = const ();
+          StorageDead(_8);
+          StorageDead(_7);
+          StorageDead(_6);
+          StorageDead(_5);
+          StorageDead(_4);
+          StorageDead(_3);
+          return;
+      }
+  }
+  

tests/mir-opt/instsimplify/ref_of_deref.references.InstSimplify.diff

@@ -0,0 +1,58 @@
+- // MIR for `references` before InstSimplify
++ // MIR for `references` after InstSimplify
+  
+  fn references(_1: &i32, _2: &mut [i32]) -> () {
+      debug const_ref => _1;
+      debug mut_ref => _2;
+      let mut _0: ();
+      let _3: &i32;
+      scope 1 {
+          debug _a => _3;
+          let _4: &[i32];
+          scope 2 {
+              debug _b => _4;
+              let _5: &mut [i32];
+              scope 3 {
+                  debug _c => _5;
+                  let _6: *const i32;
+                  scope 4 {
+                      debug _d => _6;
+                      let _7: *const [i32];
+                      scope 5 {
+                          debug _e => _7;
+                          let _8: *mut [i32];
+                          scope 6 {
+                              debug _f => _8;
+                          }
+                      }
+                  }
+              }
+          }
+      }
+  
+      bb0: {
+          StorageLive(_3);
+-         _3 = &(*_1);
++         _3 = _1;
+          StorageLive(_4);
+          _4 = &(*_2);
+          StorageLive(_5);
+-         _5 = &mut (*_2);
++         _5 = _2;
+          StorageLive(_6);
+          _6 = &raw const (*_1);
+          StorageLive(_7);
+          _7 = &raw const (*_2);
+          StorageLive(_8);
+          _8 = &raw mut (*_2);
+          _0 = const ();
+          StorageDead(_8);
+          StorageDead(_7);
+          StorageDead(_6);
+          StorageDead(_5);
+          StorageDead(_4);
+          StorageDead(_3);
+          return;
+      }
+  }
+  

tests/mir-opt/instsimplify/ref_of_deref.rs

@@ -0,0 +1,40 @@
+//@ test-mir-pass: InstSimplify
+#![crate_type = "lib"]
+#![feature(raw_ref_op)]
+
+// For each of these, only 2 of the 6 should simplify,
+// as the others have the wrong types.
+
+// EMIT_MIR ref_of_deref.references.InstSimplify.diff
+// CHECK-LABEL: references
+pub fn references(const_ref: &i32, mut_ref: &mut [i32]) {
+    // CHECK: _3 = _1;
+    let _a = &*const_ref;
+    // CHECK: _4 = &(*_2);
+    let _b = &*mut_ref;
+    // CHECK: _5 = _2;
+    let _c = &mut *mut_ref;
+    // CHECK: _6 = &raw const (*_1);
+    let _d = &raw const *const_ref;
+    // CHECK: _7 = &raw const (*_2);
+    let _e = &raw const *mut_ref;
+    // CHECK: _8 = &raw mut (*_2);
+    let _f = &raw mut *mut_ref;
+}
+
+// EMIT_MIR ref_of_deref.pointers.InstSimplify.diff
+// CHECK-LABEL: pointers
+pub unsafe fn pointers(const_ptr: *const [i32], mut_ptr: *mut i32) {
+    // CHECK: _3 = &(*_1);
+    let _a = &*const_ptr;
+    // CHECK: _4 = &(*_2);
+    let _b = &*mut_ptr;
+    // CHECK: _5 = &mut (*_2);
+    let _c = &mut *mut_ptr;
+    // CHECK: _6 = _1;
+    let _d = &raw const *const_ptr;
+    // CHECK: _7 = &raw const (*_2);
+    let _e = &raw const *mut_ptr;
+    // CHECK: _8 = _2;
+    let _f = &raw mut *mut_ptr;
+}

tests/ui/instrument-coverage/coverage-options.bad.stderr

@@ -1,2 +1,2 @@
-error: incorrect value `bad` for unstable option `coverage-options` - `block` | `branch` | `mcdc` was expected
+error: incorrect value `bad` for unstable option `coverage-options` - `block` | `branch` | `condition` | `mcdc` was expected
 

tests/ui/instrument-coverage/coverage-options.rs

@@ -1,5 +1,5 @@
 //@ needs-profiler-support
-//@ revisions: block branch mcdc bad
+//@ revisions: block branch condition mcdc bad
 //@ compile-flags -Cinstrument-coverage
 
 //@ [block] check-pass
@@ -8,6 +8,9 @@
 //@ [branch] check-pass
 //@ [branch] compile-flags: -Zcoverage-options=branch
 
+//@ [condition] check-pass
+//@ [condition] compile-flags: -Zcoverage-options=condition
+
 //@ [mcdc] check-pass
 //@ [mcdc] compile-flags: -Zcoverage-options=mcdc
 

tests/ui/specialization/source-impl-requires-constraining-predicates-ambig.next.stderr

@@ -0,0 +1,12 @@
+warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/source-impl-requires-constraining-predicates-ambig.rs:14:12
+   |
+LL | #![feature(specialization)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
+   = help: consider using `min_specialization` instead, which is more stable and complete
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+

tests/ui/specialization/source-impl-requires-constraining-predicates-ambig.rs

@@ -0,0 +1,29 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+//@[next] check-pass
+//@[current] known-bug: unknown
+//@[current] failure-status: 101
+//@[current] dont-check-compiler-stderr
+
+// Tests that rebasing from the concrete impl to the default impl also processes the
+// `[u32; 0]: IntoIterator<Item = ?U>` predicate to constrain the `?U` impl arg.
+// This test also makes sure that we don't do anything weird when rebasing the args
+// is ambiguous.
+
+#![feature(specialization)]
+//[next]~^ WARN the feature `specialization` is incomplete
+
+trait Spec {
+    type Assoc;
+}
+
+default impl<T, U> Spec for T where T: IntoIterator<Item = U> {
+    type Assoc = U;
+}
+
+impl<T> Spec for [T; 0] {}
+
+fn main() {
+    let x: <[_; 0] as Spec>::Assoc = 1;
+}

tests/ui/specialization/source-impl-requires-constraining-predicates.current.stderr

@@ -0,0 +1,12 @@
+warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/source-impl-requires-constraining-predicates.rs:9:12
+   |
+LL | #![feature(specialization)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
+   = help: consider using `min_specialization` instead, which is more stable and complete
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+

tests/ui/specialization/source-impl-requires-constraining-predicates.next.stderr

@@ -0,0 +1,12 @@
+warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/source-impl-requires-constraining-predicates.rs:9:12
+   |
+LL | #![feature(specialization)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
+   = help: consider using `min_specialization` instead, which is more stable and complete
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+

tests/ui/specialization/source-impl-requires-constraining-predicates.rs

@@ -0,0 +1,24 @@
+//@ check-pass
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+
+// Tests that rebasing from the concrete impl to the default impl also processes the
+// `[u32; 0]: IntoIterator<Item = ?U>` predicate to constrain the `?U` impl arg.
+
+#![feature(specialization)]
+//~^ WARN the feature `specialization` is incomplete
+
+trait Spec {
+    type Assoc;
+}
+
+default impl<T, U> Spec for T where T: IntoIterator<Item = U> {
+    type Assoc = U;
+}
+
+impl<T> Spec for [T; 0] {}
+
+fn main() {
+    let x: <[u32; 0] as Spec>::Assoc = 1;
+}

tests/ui/type-alias-impl-trait/const_generic_type.infer.stderr

@@ -0,0 +1,10 @@
+error: `Bar` is forbidden as the type of a const generic parameter
+  --> $DIR/const_generic_type.rs:7:24
+   |
+LL | async fn test<const N: crate::Bar>() {
+   |                        ^^^^^^^^^^
+   |
+   = note: the only supported types are integers, `bool` and `char`
+
+error: aborting due to 1 previous error
+

tests/ui/type-alias-impl-trait/const_generic_type.no_infer.stderr

@@ -0,0 +1,19 @@
+error[E0283]: type annotations needed
+  --> $DIR/const_generic_type.rs:7:1
+   |
+LL | async fn test<const N: crate::Bar>() {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type
+   |
+   = note: cannot satisfy `_: std::fmt::Display`
+
+error: `Bar` is forbidden as the type of a const generic parameter
+  --> $DIR/const_generic_type.rs:7:24
+   |
+LL | async fn test<const N: crate::Bar>() {
+   |                        ^^^^^^^^^^
+   |
+   = note: the only supported types are integers, `bool` and `char`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0283`.

tests/ui/type-alias-impl-trait/const_generic_type.rs

@@ -0,0 +1,14 @@
+//@edition: 2021
+//@revisions: infer no_infer
+
+#![feature(type_alias_impl_trait)]
+type Bar = impl std::fmt::Display;
+
+async fn test<const N: crate::Bar>() {
+    //[no_infer]~^ ERROR: type annotations needed
+    //~^^ ERROR: `Bar` is forbidden as the type of a const generic parameter
+    #[cfg(infer)]
+    let x: u32 = N;
+}
+
+fn main() {}