Merging debian version 1.65.0+dfsg1-2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 219 insertions, 117 deletions

diff --git a/compiler/rustc_monomorphize/Cargo.toml b/compiler/rustc_monomorphize/Cargo.toml
index 41ba4d4b6..59ca04ec8 100644
--- a/compiler/rustc_monomorphize/Cargo.toml
+++ b/compiler/rustc_monomorphize/Cargo.toml
@@ -7,11 +7,13 @@ edition = "2021"
 doctest = false
 
 [dependencies]
-smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
+smallvec = { version = "1.8.1", features = [ "union", "may_dangle" ] }
 tracing = "0.1"
 rustc_data_structures = { path = "../rustc_data_structures" }
+rustc_errors = { path = "../rustc_errors" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
+rustc_macros = { path = "../rustc_macros" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index 68b65658c..f1a25a60d 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -112,12 +112,6 @@
 //! method in operand position, we treat it as a neighbor of the current
 //! mono item. Calls are just a special case of that.
 //!
-//! #### Closures
-//! In a way, closures are a simple case. Since every closure object needs to be
-//! constructed somewhere, we can reliably discover them by observing
-//! `RValue::Aggregate` expressions with `AggregateKind::Closure`. This is also
-//! true for closures inlined from other crates.
-//!
 //! #### Drop glue
 //! Drop glue mono items are introduced by MIR drop-statements. The
 //! generated mono item will again have drop-glue item neighbors if the
@@ -128,7 +122,7 @@
 //! #### Unsizing Casts
 //! A subtle way of introducing neighbor edges is by casting to a trait object.
 //! Since the resulting fat-pointer contains a reference to a vtable, we need to
-//! instantiate all object-save methods of the trait, as we need to store
+//! instantiate all object-safe methods of the trait, as we need to store
 //! pointers to these functions even if they never get called anywhere. This can
 //! be seen as a special case of taking a function reference.
 //!
@@ -207,6 +201,8 @@ use std::iter;
 use std::ops::Range;
 use std::path::PathBuf;
 
+use crate::errors::{LargeAssignmentsLint, RecursionLimit, RequiresLangItem, TypeLengthLimit};
+
 #[derive(PartialEq)]
 pub enum MonoItemCollectionMode {
     Eager,
@@ -417,7 +413,6 @@ fn collect_items_rec<'tcx>(
         // We've been here already, no need to search again.
         return;
     }
-    debug!("BEGIN collect_items_rec({})", starting_point.node);
 
     let mut neighbors = MonoItems { compute_inlining: true, tcx, items: Vec::new() };
     let recursion_depth_reset;
@@ -461,7 +456,7 @@ fn collect_items_rec<'tcx>(
             recursion_depth_reset = None;
 
             if let Ok(alloc) = tcx.eval_static_initializer(def_id) {
-                for &id in alloc.inner().relocations().values() {
+                for &id in alloc.inner().provenance().values() {
                     collect_miri(tcx, id, &mut neighbors);
                 }
             }
@@ -543,8 +538,6 @@ fn collect_items_rec<'tcx>(
     if let Some((def_id, depth)) = recursion_depth_reset {
         recursion_depths.insert(def_id, depth);
     }
-
-    debug!("END collect_items_rec({})", starting_point.node);
 }
 
 /// Format instance name that is already known to be too long for rustc.
@@ -604,17 +597,24 @@ fn check_recursion_limit<'tcx>(
     // more than the recursion limit is assumed to be causing an
     // infinite expansion.
     if !recursion_limit.value_within_limit(adjusted_recursion_depth) {
+        let def_span = tcx.def_span(def_id);
+        let def_path_str = tcx.def_path_str(def_id);
         let (shrunk, written_to_path) = shrunk_instance_name(tcx, &instance, 32, 32);
-        let error = format!("reached the recursion limit while instantiating `{}`", shrunk);
-        let mut err = tcx.sess.struct_span_fatal(span, &error);
-        err.span_note(
-            tcx.def_span(def_id),
-            &format!("`{}` defined here", tcx.def_path_str(def_id)),
-        );
-        if let Some(path) = written_to_path {
-            err.note(&format!("the full type name has been written to '{}'", path.display()));
-        }
-        err.emit()
+        let mut path = PathBuf::new();
+        let was_written = if written_to_path.is_some() {
+            path = written_to_path.unwrap();
+            Some(())
+        } else {
+            None
+        };
+        tcx.sess.emit_fatal(RecursionLimit {
+            span,
+            shrunk,
+            def_span,
+            def_path_str,
+            was_written,
+            path,
+        });
     }
 
     recursion_depths.insert(def_id, recursion_depth + 1);
@@ -642,16 +642,15 @@ fn check_type_length_limit<'tcx>(tcx: TyCtxt<'tcx>, instance: Instance<'tcx>) {
     // Bail out in these cases to avoid that bad user experience.
     if !tcx.type_length_limit().value_within_limit(type_length) {
         let (shrunk, written_to_path) = shrunk_instance_name(tcx, &instance, 32, 32);
-        let msg = format!("reached the type-length limit while instantiating `{}`", shrunk);
-        let mut diag = tcx.sess.struct_span_fatal(tcx.def_span(instance.def_id()), &msg);
-        if let Some(path) = written_to_path {
-            diag.note(&format!("the full type name has been written to '{}'", path.display()));
-        }
-        diag.help(&format!(
-            "consider adding a `#![type_length_limit=\"{}\"]` attribute to your crate",
-            type_length
-        ));
-        diag.emit()
+        let span = tcx.def_span(instance.def_id());
+        let mut path = PathBuf::new();
+        let was_written = if written_to_path.is_some() {
+            path = written_to_path.unwrap();
+            Some(())
+        } else {
+            None
+        };
+        tcx.sess.emit_fatal(TypeLengthLimit { span, shrunk, was_written, path, type_length });
     }
 }
 
@@ -690,7 +689,8 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
                 mir::CastKind::Pointer(PointerCast::Unsize),
                 ref operand,
                 target_ty,
-            ) => {
+            )
+            | mir::Rvalue::Cast(mir::CastKind::DynStar, ref operand, target_ty) => {
                 let target_ty = self.monomorphize(target_ty);
                 let source_ty = operand.ty(self.body, self.tcx);
                 let source_ty = self.monomorphize(source_ty);
@@ -699,7 +699,9 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
                 // This could also be a different Unsize instruction, like
                 // from a fixed sized array to a slice. But we are only
                 // interested in things that produce a vtable.
-                if target_ty.is_trait() && !source_ty.is_trait() {
+                if (target_ty.is_trait() && !source_ty.is_trait())
+                    || (target_ty.is_dyn_star() && !source_ty.is_dyn_star())
+                {
                     create_mono_items_for_vtable_methods(
                         self.tcx,
                         target_ty,
@@ -768,7 +770,7 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
                 ty::ConstKind::Unevaluated(ct) => {
                     debug!(?ct);
                     let param_env = ty::ParamEnv::reveal_all();
-                    match self.tcx.const_eval_resolve(param_env, ct, None) {
+                    match self.tcx.const_eval_resolve(param_env, ct.expand(), None) {
                         // The `monomorphize` call should have evaluated that constant already.
                         Ok(val) => val,
                         Err(ErrorHandled::Reported(_) | ErrorHandled::Linted) => return,
@@ -781,44 +783,22 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
                 }
                 _ => return,
             },
-        };
-        collect_const_value(self.tcx, val, self.output);
-        self.visit_ty(literal.ty(), TyContext::Location(location));
-    }
-
-    #[instrument(skip(self), level = "debug")]
-    fn visit_const(&mut self, constant: ty::Const<'tcx>, location: Location) {
-        debug!("visiting const {:?} @ {:?}", constant, location);
-
-        let substituted_constant = self.monomorphize(constant);
-        let param_env = ty::ParamEnv::reveal_all();
-
-        match substituted_constant.kind() {
-            ty::ConstKind::Value(val) => {
-                let const_val = self.tcx.valtree_to_const_val((constant.ty(), val));
-                collect_const_value(self.tcx, const_val, self.output)
-            }
-            ty::ConstKind::Unevaluated(unevaluated) => {
-                match self.tcx.const_eval_resolve(param_env, unevaluated, None) {
+            mir::ConstantKind::Unevaluated(uv, _) => {
+                let param_env = ty::ParamEnv::reveal_all();
+                match self.tcx.const_eval_resolve(param_env, uv, None) {
                     // The `monomorphize` call should have evaluated that constant already.
-                    Ok(val) => span_bug!(
-                        self.body.source_info(location).span,
-                        "collection encountered the unevaluated constant {} which evaluated to {:?}",
-                        substituted_constant,
-                        val
-                    ),
-                    Err(ErrorHandled::Reported(_) | ErrorHandled::Linted) => {}
+                    Ok(val) => val,
+                    Err(ErrorHandled::Reported(_) | ErrorHandled::Linted) => return,
                     Err(ErrorHandled::TooGeneric) => span_bug!(
                         self.body.source_info(location).span,
-                        "collection encountered polymorphic constant: {}",
-                        substituted_constant
+                        "collection encountered polymorphic constant: {:?}",
+                        literal
                     ),
                 }
             }
-            _ => {}
-        }
-
-        self.super_const(constant);
+        };
+        collect_const_value(self.tcx, val, self.output);
+        MirVisitor::visit_ty(self, literal.ty(), TyContext::Location(location));
     }
 
     fn visit_terminator(&mut self, terminator: &mir::Terminator<'tcx>, location: Location) {
@@ -830,7 +810,7 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
             mir::TerminatorKind::Call { ref func, .. } => {
                 let callee_ty = func.ty(self.body, tcx);
                 let callee_ty = self.monomorphize(callee_ty);
-                visit_fn_use(self.tcx, callee_ty, true, source, &mut self.output);
+                visit_fn_use(self.tcx, callee_ty, true, source, &mut self.output)
             }
             mir::TerminatorKind::Drop { ref place, .. }
             | mir::TerminatorKind::DropAndReplace { ref place, .. } => {
@@ -914,17 +894,16 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> {
                     // but correct span? This would make the lint at least accept crate-level lint attributes.
                     return;
                 };
-                self.tcx.struct_span_lint_hir(
+                self.tcx.emit_spanned_lint(
                     LARGE_ASSIGNMENTS,
                     lint_root,
                     source_info.span,
-                    |lint| {
-                        let mut err = lint.build(&format!("moving {} bytes", layout.size.bytes()));
-                        err.span_label(source_info.span, "value moved from here");
-                        err.note(&format!(r#"The current maximum size is {}, but it can be customized with the move_size_limit attribute: `#![move_size_limit = "..."]`"#, limit.bytes()));
-                        err.emit();
+                    LargeAssignmentsLint {
+                        span: source_info.span,
+                        size: layout.size.bytes(),
+                        limit: limit.bytes(),
                     },
-                );
+                )
             }
         }
     }
@@ -1027,6 +1006,11 @@ fn should_codegen_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx>) ->
         return false;
     }
 
+    if let DefKind::Static(_) = tcx.def_kind(def_id) {
+        // We cannot monomorphize statics from upstream crates.
+        return false;
+    }
+
     if !tcx.is_mir_available(def_id) {
         bug!("no MIR available for {:?}", def_id);
     }
@@ -1039,10 +1023,12 @@ fn should_codegen_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx>) ->
 /// them.
 ///
 /// For example, the source type might be `&SomeStruct` and the target type
-/// might be `&SomeTrait` in a cast like:
+/// might be `&dyn SomeTrait` in a cast like:
 ///
+/// ```rust,ignore (not real code)
 /// let src: &SomeStruct = ...;
-/// let target = src as &SomeTrait;
+/// let target = src as &dyn SomeTrait;
+/// ```
 ///
 /// Then the output of this function would be (SomeStruct, SomeTrait) since for
 /// constructing the `target` fat-pointer we need the vtable for that pair.
@@ -1063,8 +1049,10 @@ fn should_codegen_locally<'tcx>(tcx: TyCtxt<'tcx>, instance: &Instance<'tcx>) ->
 /// for the pair of `T` (which is a trait) and the concrete type that `T` was
 /// originally coerced from:
 ///
+/// ```rust,ignore (not real code)
 /// let src: &ComplexStruct<SomeStruct> = ...;
-/// let target = src as &ComplexStruct<SomeTrait>;
+/// let target = src as &ComplexStruct<dyn SomeTrait>;
+/// ```
 ///
 /// Again, we want this `find_vtable_types_for_unsizing()` to provide the pair
 /// `(SomeStruct, SomeTrait)`.
@@ -1105,6 +1093,9 @@ fn find_vtable_types_for_unsizing<'tcx>(
             ptr_vtable(source_ty.boxed_ty(), target_ty.boxed_ty())
         }
 
+        // T as dyn* Trait
+        (_, &ty::Dynamic(_, _, ty::DynStar)) => ptr_vtable(source_ty, target_ty),
+
         (&ty::Adt(source_adt_def, source_substs), &ty::Adt(target_adt_def, target_substs)) => {
             assert_eq!(source_adt_def, target_adt_def);
 
@@ -1132,23 +1123,18 @@ fn find_vtable_types_for_unsizing<'tcx>(
     }
 }
 
-#[instrument(skip(tcx), level = "debug")]
+#[instrument(skip(tcx), level = "debug", ret)]
 fn create_fn_mono_item<'tcx>(
     tcx: TyCtxt<'tcx>,
     instance: Instance<'tcx>,
     source: Span,
 ) -> Spanned<MonoItem<'tcx>> {
-    debug!("create_fn_mono_item(instance={})", instance);
-
     let def_id = instance.def_id();
     if tcx.sess.opts.unstable_opts.profile_closures && def_id.is_local() && tcx.is_closure(def_id) {
         crate::util::dump_closure_profile(tcx, instance);
     }
 
-    let respanned = respan(source, MonoItem::Fn(instance.polymorphize(tcx)));
-    debug!(?respanned);
-
-    respanned
+    respan(source, MonoItem::Fn(instance.polymorphize(tcx)))
 }
 
 /// Creates a `MonoItem` for each method that is referenced by the vtable for
@@ -1293,7 +1279,7 @@ impl<'v> RootCollector<'_, 'v> {
     #[instrument(skip(self), level = "debug")]
     fn push_if_root(&mut self, def_id: LocalDefId) {
         if self.is_root(def_id) {
-            debug!("RootCollector::push_if_root: found root def_id={:?}", def_id);
+            debug!("found root");
 
             let instance = Instance::mono(self.tcx, def_id.to_def_id());
             self.output.push(create_fn_mono_item(self.tcx, instance, DUMMY_SP));
@@ -1306,13 +1292,17 @@ impl<'v> RootCollector<'_, 'v> {
     /// the return type of `main`. This is not needed when
     /// the user writes their own `start` manually.
     fn push_extra_entry_roots(&mut self) {
-        let Some((main_def_id, EntryFnType::Main)) = self.entry_fn else {
+        let Some((main_def_id, EntryFnType::Main { .. })) = self.entry_fn else {
             return;
         };
 
         let start_def_id = match self.tcx.lang_items().require(LangItem::Start) {
             Ok(s) => s,
-            Err(err) => self.tcx.sess.fatal(&err),
+            Err(lang_item_err) => {
+                self.tcx
+                    .sess
+                    .emit_fatal(RequiresLangItem { lang_item: lang_item_err.0.name().to_string() });
+            }
         };
         let main_ret_ty = self.tcx.fn_sig(main_def_id).output();
 
@@ -1415,7 +1405,7 @@ fn collect_miri<'tcx>(tcx: TyCtxt<'tcx>, alloc_id: AllocId, output: &mut MonoIte
         }
         GlobalAlloc::Memory(alloc) => {
             trace!("collecting {:?} with {:#?}", alloc_id, alloc);
-            for &inner in alloc.inner().relocations().values() {
+            for &inner in alloc.inner().provenance().values() {
                 rustc_data_structures::stack::ensure_sufficient_stack(|| {
                     collect_miri(tcx, inner, output);
                 });
@@ -1454,7 +1444,7 @@ fn collect_const_value<'tcx>(
     match value {
         ConstValue::Scalar(Scalar::Ptr(ptr, _size)) => collect_miri(tcx, ptr.provenance, output),
         ConstValue::Slice { data: alloc, start: _, end: _ } | ConstValue::ByRef { alloc, .. } => {
-            for &id in alloc.inner().relocations().values() {
+            for &id in alloc.inner().provenance().values() {
                 collect_miri(tcx, id, output);
             }
         }
diff --git a/compiler/rustc_monomorphize/src/errors.rs b/compiler/rustc_monomorphize/src/errors.rs
new file mode 100644
index 000000000..d5f05e790
--- /dev/null
+++ b/compiler/rustc_monomorphize/src/errors.rs
@@ -0,0 +1,85 @@
+use std::path::PathBuf;
+
+use rustc_errors::ErrorGuaranteed;
+use rustc_macros::{LintDiagnostic, SessionDiagnostic};
+use rustc_session::SessionDiagnostic;
+use rustc_span::Span;
+
+#[derive(SessionDiagnostic)]
+#[diag(monomorphize::recursion_limit)]
+pub struct RecursionLimit {
+    #[primary_span]
+    pub span: Span,
+    pub shrunk: String,
+    #[note]
+    pub def_span: Span,
+    pub def_path_str: String,
+    #[note(monomorphize::written_to_path)]
+    pub was_written: Option<()>,
+    pub path: PathBuf,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(monomorphize::type_length_limit)]
+#[help(monomorphize::consider_type_length_limit)]
+pub struct TypeLengthLimit {
+    #[primary_span]
+    pub span: Span,
+    pub shrunk: String,
+    #[note(monomorphize::written_to_path)]
+    pub was_written: Option<()>,
+    pub path: PathBuf,
+    pub type_length: usize,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(monomorphize::requires_lang_item)]
+pub struct RequiresLangItem {
+    pub lang_item: String,
+}
+
+pub struct UnusedGenericParams {
+    pub span: Span,
+    pub param_spans: Vec<Span>,
+    pub param_names: Vec<String>,
+}
+
+impl SessionDiagnostic<'_> for UnusedGenericParams {
+    fn into_diagnostic(
+        self,
+        handler: &'_ rustc_errors::Handler,
+    ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> {
+        let mut diag =
+            handler.struct_err(rustc_errors::fluent::monomorphize::unused_generic_params);
+        diag.set_span(self.span);
+        for (span, name) in self.param_spans.into_iter().zip(self.param_names) {
+            // FIXME: I can figure out how to do a label with a fluent string with a fixed message,
+            // or a label with a dynamic value in a hard-coded string, but I haven't figured out
+            // how to combine the two. 😢
+            diag.span_label(span, format!("generic parameter `{}` is unused", name));
+        }
+        diag
+    }
+}
+
+#[derive(LintDiagnostic)]
+#[diag(monomorphize::large_assignments)]
+#[note]
+pub struct LargeAssignmentsLint {
+    #[label]
+    pub span: Span,
+    pub size: u64,
+    pub limit: u64,
+}
+
+#[derive(SessionDiagnostic)]
+#[diag(monomorphize::unknown_partition_strategy)]
+pub struct UnknownPartitionStrategy;
+
+#[derive(SessionDiagnostic)]
+#[diag(monomorphize::symbol_already_defined)]
+pub struct SymbolAlreadyDefined {
+    #[primary_span]
+    pub span: Option<Span>,
+    pub symbol: String,
+}
diff --git a/compiler/rustc_monomorphize/src/lib.rs b/compiler/rustc_monomorphize/src/lib.rs
index ef4560b5e..ba6ce9fd4 100644
--- a/compiler/rustc_monomorphize/src/lib.rs
+++ b/compiler/rustc_monomorphize/src/lib.rs
@@ -1,8 +1,10 @@
 #![feature(array_windows)]
 #![feature(control_flow_enum)]
-#![feature(let_else)]
+#![cfg_attr(bootstrap, feature(let_else))]
 #![recursion_limit = "256"]
 #![allow(rustc::potential_query_instability)]
+#![deny(rustc::untranslatable_diagnostic)]
+#![deny(rustc::diagnostic_outside_of_impl)]
 
 #[macro_use]
 extern crate tracing;
@@ -16,6 +18,7 @@ use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, Ty, TyCtxt};
 
 mod collector;
+mod errors;
 mod partitioning;
 mod polymorphize;
 mod util;
@@ -32,7 +35,7 @@ fn custom_coerce_unsize_info<'tcx>(
         substs: tcx.mk_substs_trait(source_ty, &[target_ty.into()]),
     });
 
-    match tcx.codegen_fulfill_obligation((ty::ParamEnv::reveal_all(), trait_ref)) {
+    match tcx.codegen_select_candidate((ty::ParamEnv::reveal_all(), trait_ref)) {
         Ok(traits::ImplSource::UserDefined(traits::ImplSourceUserDefinedData {
             impl_def_id,
             ..
diff --git a/compiler/rustc_monomorphize/src/partitioning/mod.rs b/compiler/rustc_monomorphize/src/partitioning/mod.rs
index ff2d38693..932edc667 100644
--- a/compiler/rustc_monomorphize/src/partitioning/mod.rs
+++ b/compiler/rustc_monomorphize/src/partitioning/mod.rs
@@ -108,6 +108,7 @@ use rustc_span::symbol::Symbol;
 
 use crate::collector::InliningMap;
 use crate::collector::{self, MonoItemCollectionMode};
+use crate::errors::{SymbolAlreadyDefined, UnknownPartitionStrategy};
 
 pub struct PartitioningCx<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
@@ -149,7 +150,9 @@ fn get_partitioner<'tcx>(tcx: TyCtxt<'tcx>) -> Box<dyn Partitioner<'tcx>> {
 
     match strategy {
         "default" => Box::new(default::DefaultPartitioning),
-        _ => tcx.sess.fatal("unknown partitioning strategy"),
+        _ => {
+            tcx.sess.emit_fatal(UnknownPartitionStrategy);
+        }
     }
 }
 
@@ -331,13 +334,7 @@ where
                 (span1, span2) => span1.or(span2),
             };
 
-            let error_message = format!("symbol `{}` is already defined", sym1);
-
-            if let Some(span) = span {
-                tcx.sess.span_fatal(span, &error_message)
-            } else {
-                tcx.sess.fatal(&error_message)
-            }
+            tcx.sess.emit_fatal(SymbolAlreadyDefined { span, symbol: sym1.to_string() });
         }
     }
 }
@@ -481,7 +478,7 @@ fn codegened_and_inlined_items<'tcx>(tcx: TyCtxt<'tcx>, (): ()) -> &'tcx DefIdSe
                     continue;
                 }
                 let body = tcx.instance_mir(instance.def);
-                for block in body.basic_blocks() {
+                for block in body.basic_blocks.iter() {
                     for statement in &block.statements {
                         let mir::StatementKind::Coverage(_) = statement.kind else { continue };
                         let scope = statement.source_info.scope;
diff --git a/compiler/rustc_monomorphize/src/polymorphize.rs b/compiler/rustc_monomorphize/src/polymorphize.rs
index 394843e51..71cab0232 100644
--- a/compiler/rustc_monomorphize/src/polymorphize.rs
+++ b/compiler/rustc_monomorphize/src/polymorphize.rs
@@ -9,7 +9,7 @@ use rustc_hir::{def::DefKind, def_id::DefId, ConstContext};
 use rustc_index::bit_set::FiniteBitSet;
 use rustc_middle::mir::{
     visit::{TyContext, Visitor},
-    Local, LocalDecl, Location,
+    Constant, ConstantKind, Local, LocalDecl, Location,
 };
 use rustc_middle::ty::{
     self,
@@ -22,6 +22,8 @@ use rustc_span::symbol::sym;
 use std::convert::TryInto;
 use std::ops::ControlFlow;
 
+use crate::errors::UnusedGenericParams;
+
 /// Provide implementations of queries relating to polymorphization analysis.
 pub fn provide(providers: &mut Providers) {
     providers.unused_generic_params = unused_generic_params;
@@ -31,7 +33,6 @@ pub fn provide(providers: &mut Providers) {
 ///
 /// Returns a bitset where bits representing unused parameters are set (`is_empty` indicates all
 /// parameters are used).
-#[instrument(level = "debug", skip(tcx))]
 fn unused_generic_params<'tcx>(
     tcx: TyCtxt<'tcx>,
     instance: ty::InstanceDef<'tcx>,
@@ -169,6 +170,7 @@ fn mark_used_by_default_parameters<'tcx>(
         | DefKind::AnonConst
         | DefKind::InlineConst
         | DefKind::OpaqueTy
+        | DefKind::ImplTraitPlaceholder
         | DefKind::Field
         | DefKind::LifetimeParam
         | DefKind::GlobalAsm
@@ -206,22 +208,23 @@ fn emit_unused_generic_params_error<'tcx>(
         _ => tcx.def_span(def_id),
     };
 
-    let mut err = tcx.sess.struct_span_err(fn_span, "item has unused generic parameters");
-
+    let mut param_spans = Vec::new();
+    let mut param_names = Vec::new();
     let mut next_generics = Some(generics);
     while let Some(generics) = next_generics {
         for param in &generics.params {
             if unused_parameters.contains(param.index).unwrap_or(false) {
                 debug!(?param);
                 let def_span = tcx.def_span(param.def_id);
-                err.span_label(def_span, &format!("generic parameter `{}` is unused", param.name));
+                param_spans.push(def_span);
+                param_names.push(param.name.to_string());
             }
         }
 
         next_generics = generics.parent.map(|did| tcx.generics_of(did));
     }
 
-    err.emit();
+    tcx.sess.emit_err(UnusedGenericParams { span: fn_span, param_spans, param_names });
 }
 
 /// Visitor used to aggregate generic parameter uses.
@@ -267,8 +270,15 @@ impl<'a, 'tcx> Visitor<'tcx> for MarkUsedGenericParams<'a, 'tcx> {
         self.super_local_decl(local, local_decl);
     }
 
-    fn visit_const(&mut self, c: Const<'tcx>, _: Location) {
-        c.visit_with(self);
+    fn visit_constant(&mut self, ct: &Constant<'tcx>, location: Location) {
+        match ct.literal {
+            ConstantKind::Ty(c) => {
+                c.visit_with(self);
+            }
+            ConstantKind::Val(_, ty) | ConstantKind::Unevaluated(_, ty) => {
+                Visitor::visit_ty(self, ty, TyContext::Location(location))
+            }
+        }
     }
 
     fn visit_ty(&mut self, ty: Ty<'tcx>, _: TyContext) {
@@ -289,7 +299,26 @@ impl<'a, 'tcx> TypeVisitor<'tcx> for MarkUsedGenericParams<'a, 'tcx> {
                 self.unused_parameters.clear(param.index);
                 ControlFlow::CONTINUE
             }
-            ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs: _, promoted: Some(p)})
+            ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs, promoted })
+                if matches!(self.tcx.def_kind(def.did), DefKind::AnonConst) =>
+            {
+                assert_eq!(promoted, ());
+
+                self.visit_child_body(def.did, substs);
+                ControlFlow::CONTINUE
+            }
+            _ => c.super_visit_with(self),
+        }
+    }
+
+    fn visit_mir_const(&mut self, constant: ConstantKind<'tcx>) -> ControlFlow<Self::BreakTy> {
+        if !constant.has_param_types_or_consts() {
+            return ControlFlow::CONTINUE;
+        }
+
+        match constant {
+            ConstantKind::Ty(ct) => ct.visit_with(self),
+            ConstantKind::Unevaluated(ty::Unevaluated { def, substs: _, promoted: Some(p) }, _)
                 // Avoid considering `T` unused when constants are of the form:
                 //   `<Self as Foo<T>>::foo::promoted[p]`
                 if self.def_id == def.did && !self.tcx.generics_of(def.did).has_self =>
@@ -300,13 +329,9 @@ impl<'a, 'tcx> TypeVisitor<'tcx> for MarkUsedGenericParams<'a, 'tcx> {
                 self.visit_body(&promoted[p]);
                 ControlFlow::CONTINUE
             }
-            ty::ConstKind::Unevaluated(uv)
-                if matches!(self.tcx.def_kind(uv.def.did), DefKind::AnonConst | DefKind::InlineConst) =>
-            {
-                self.visit_child_body(uv.def.did, uv.substs);
-                ControlFlow::CONTINUE
+            ConstantKind::Val(..) | ConstantKind::Unevaluated(..) => {
+                constant.super_visit_with(self)
             }
-            _ => c.super_visit_with(self),
         }
     }
 
diff --git a/compiler/rustc_monomorphize/src/util.rs b/compiler/rustc_monomorphize/src/util.rs
index 847e64dc2..6a4d2df1e 100644
--- a/compiler/rustc_monomorphize/src/util.rs
+++ b/compiler/rustc_monomorphize/src/util.rs
@@ -13,7 +13,7 @@ pub(crate) fn dump_closure_profile<'tcx>(tcx: TyCtxt<'tcx>, closure_instance: In
         .append(true)
         .open(&format!("closure_profile_{}.csv", std::process::id()))
     else {
-        eprintln!("Cound't open file for writing closure profile");
+        eprintln!("Couldn't open file for writing closure profile");
         return;
     };