diff --git a/compiler/rustc_borrowck/src/diagnostics/region_name.rs b/compiler/rustc_borrowck/src/diagnostics/region_name.rs
index 6c1eaa809c905..05b19fcfb999a 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_name.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_name.rs
@@ -187,6 +187,12 @@ impl Display for RegionName {
     }
 }
 
+impl rustc_errors::IntoDiagnosticArg for RegionName {
+    fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> {
+        self.to_string().into_diagnostic_arg()
+    }
+}
+
 impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
     pub(crate) fn mir_def_id(&self) -> hir::def_id::LocalDefId {
         self.body.source.def_id().expect_local()
diff --git a/compiler/rustc_borrowck/src/session_diagnostics.rs b/compiler/rustc_borrowck/src/session_diagnostics.rs
index 9f19453a1a658..24f672de97bc6 100644
--- a/compiler/rustc_borrowck/src/session_diagnostics.rs
+++ b/compiler/rustc_borrowck/src/session_diagnostics.rs
@@ -1,4 +1,4 @@
-use rustc_errors::{IntoDiagnosticArg, MultiSpan};
+use rustc_errors::MultiSpan;
 use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
 use rustc_middle::ty::Ty;
 use rustc_span::Span;
@@ -137,18 +137,6 @@ pub(crate) enum LifetimeReturnCategoryErr<'a> {
     },
 }
 
-impl IntoDiagnosticArg for &RegionName {
-    fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> {
-        format!("{}", self).into_diagnostic_arg()
-    }
-}
-
-impl IntoDiagnosticArg for RegionName {
-    fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> {
-        format!("{}", self).into_diagnostic_arg()
-    }
-}
-
 #[derive(Subdiagnostic)]
 pub(crate) enum RequireStaticErr {
     #[note(borrowck::used_impl_require_static)]
diff --git a/compiler/rustc_driver/src/lib.rs b/compiler/rustc_driver/src/lib.rs
index c768935eb6238..e1872243a4a68 100644
--- a/compiler/rustc_driver/src/lib.rs
+++ b/compiler/rustc_driver/src/lib.rs
@@ -1210,6 +1210,9 @@ static DEFAULT_HOOK: LazyLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send +
 ///
 /// When `install_ice_hook` is called, this function will be called as the panic
 /// hook.
+// FIXME(translation): need struct diagnostics implemented on `Handler`
+#[allow(rustc::untranslatable_diagnostic)]
+#[allow(rustc::diagnostic_outside_of_impl)]
 pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
     let fallback_bundle =
         rustc_errors::fallback_fluent_bundle(rustc_errors::DEFAULT_LOCALE_RESOURCES, false);
diff --git a/compiler/rustc_error_messages/locales/en-US/incremental.ftl b/compiler/rustc_error_messages/locales/en-US/incremental.ftl
new file mode 100644
index 0000000000000..ed9a22c02d181
--- /dev/null
+++ b/compiler/rustc_error_messages/locales/en-US/incremental.ftl
@@ -0,0 +1,106 @@
+incremental_unrecognized_depnode = unrecognized `DepNode` variant: {$name}
+
+incremental_missing_depnode = missing `DepNode` variant
+
+incremental_missing_if_this_changed = no `#[rustc_if_this_changed]` annotation detected
+
+incremental_no_path = no path from `{$source}` to `{$target}`
+
+incremental_ok = OK
+
+incremental_unknown_reuse_kind = unknown cgu-reuse-kind `{$kind}` specified
+
+incremental_missing_query_depgraph = found CGU-reuse attribute but `-Zquery-dep-graph` was not specified
+
+incremental_malformed_cgu_name =
+    found malformed codegen unit name `{$user_path}`. codegen units names must always start with the name of the crate (`{$crate_name}` in this case).
+
+incremental_no_module_named = no module named `{$user_path}` (mangled: {$cgu_name}). available modules: {$cgu_names}
+
+incremental_field_associated_value_expected = associated value expected for `{$name}`
+
+incremental_no_field = no field `{$name}`
+
+incremental_assertion_auto = `except` specified DepNodes that can not be affected for \"{$name}\": \"{$e}\"
+
+incremental_undefined_clean_dirty_assertions_item = clean/dirty auto-assertions not yet defined for Node::Item.node={$kind}
+
+incremental_undefined_clean_dirty_assertions = clean/dirty auto-assertions not yet defined for {$kind}
+
+incremental_repeated_depnode_label = dep-node label `{$label}` is repeated
+
+incremental_unrecognized_depnode_label = dep-node label `{$label}` not recognized
+
+incremental_not_dirty = `{$dep_node_str}` should be dirty but is not
+
+incremental_not_clean = `{$dep_node_str}` should be clean but is not
+
+incremental_not_loaded = `{$dep_node_str}` should have been loaded from disk but it was not
+
+incremental_unknown_item = unknown item `{$name}`
+
+incremental_no_cfg = no cfg attribute
+
+incremental_associated_value_expected_for = associated value expected for `{$ident}`
+
+incremental_associated_value_expected = expected an associated value
+
+incremental_unchecked_clean = found unchecked `#[rustc_clean]` attribute
+
+incremental_delete_old = unable to delete old {$name} at `{$path}`: {$err}
+
+incremental_create_new = failed to create {$name} at `{$path}`: {$err}
+
+incremental_write_new = failed to write {$name} to `{$path}`: {$err}
+
+incremental_canonicalize_path = incremental compilation: error canonicalizing path `{$path}`: {$err}
+
+incremental_create_incr_comp_dir = could not create incremental compilation {$tag} directory `{$path}`: {$err}
+
+incremental_create_lock = incremental compilation: could not create session directory lock file: {$lock_err}
+    .lock_unsupported = the filesystem for the incremental path at {$session_dir} does not appear to support locking, consider changing the incremental path to a filesystem that supports locking or disable incremental compilation
+    .cargo_help_1 = incremental compilation can be disabled by setting the environment variable CARGO_INCREMENTAL=0 (see https://doc.rust-lang.org/cargo/reference/profiles.html#incremental)
+    .cargo_help_2 = the entire build directory can be changed to a different filesystem by setting the environment variable CARGO_TARGET_DIR to a different path (see https://doc.rust-lang.org/cargo/reference/config.html#buildtarget-dir)
+
+incremental_delete_lock = error deleting lock file for incremental compilation session directory `{$path}`: {$err}
+
+incremental_hard_link_failed =
+    hard linking files in the incremental compilation cache failed. copying files instead. consider moving the cache directory to a file system which supports hard linking in session dir `{$path}`
+
+incremental_delete_partial = failed to delete partly initialized session dir `{$path}`: {$err}
+
+incremental_delete_full = error deleting incremental compilation session directory `{$path}`: {$err}
+
+incremental_finalize = error finalizing incremental compilation session directory `{$path}`: {$err}
+
+incremental_invalid_gc_failed =
+    failed to garbage collect invalid incremental compilation session directory `{$path}`: {$err}
+
+incremental_finalized_gc_failed =
+    failed to garbage collect finalized incremental compilation session directory `{$path}`: {$err}
+
+incremental_session_gc_failed =
+    failed to garbage collect incremental compilation session directory `{$path}`: {$err}
+
+incremental_assert_not_loaded =
+    we asserted that the incremental cache should not be loaded, but it was loaded
+
+incremental_assert_loaded =
+    we asserted that an existing incremental cache directory should be successfully loaded, but it was not
+
+incremental_delete_incompatible =
+    failed to delete invalidated or incompatible incremental compilation session directory contents `{$path}`: {$err}
+
+incremental_load_dep_graph = could not load dep-graph from `{$path}`: {$err}
+
+incremental_decode_incr_cache = could not decode incremental cache: {$err}
+
+incremental_write_dep_graph = failed to write dependency graph to `{$path}`: {$err}
+
+incremental_move_dep_graph = failed to move dependency graph from `{$from}` to `{$to}`: {$err}
+
+incremental_create_dep_graph = failed to create dependency graph at `{$path}`: {$err}
+
+incremental_copy_workproduct_to_cache = error copying object file `{$from}` to incremental directory as `{$to}`: {$err}
+
+incremental_delete_workproduct = file-system error deleting outdated file `{$path}`: {$err}
diff --git a/compiler/rustc_error_messages/locales/en-US/interface.ftl b/compiler/rustc_error_messages/locales/en-US/interface.ftl
index bbcb8fc28cffa..c7ebb920ec84f 100644
--- a/compiler/rustc_error_messages/locales/en-US/interface.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/interface.ftl
@@ -41,3 +41,13 @@ interface_rustc_error_unexpected_annotation =
 
 interface_failed_writing_file =
     failed to write file {$path}: {$error}"
+
+interface_unsupported_crate_type_for_target =
+    dropping unsupported crate type `{$crate_type}` for target `{$target_triple}`
+
+interface_multiple_output_types_adaption =
+    due to multiple output types requested, the explicitly specified output file name will be adapted for each output type
+
+interface_ignoring_extra_filename = ignoring -C extra-filename flag due to -o flag
+
+interface_ignoring_out_dir = ignoring --out-dir flag due to -o flag
diff --git a/compiler/rustc_error_messages/locales/en-US/monomorphize.ftl b/compiler/rustc_error_messages/locales/en-US/monomorphize.ftl
index 42c84fdd2d14b..5839a47fb6708 100644
--- a/compiler/rustc_error_messages/locales/en-US/monomorphize.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/monomorphize.ftl
@@ -24,3 +24,9 @@ monomorphize_large_assignments =
 
 monomorphize_requires_lang_item =
     requires `{$lang_item}` lang_item
+
+monomorphize_encountered_error_while_instantiating =
+    the above error was encountered while instantiating `{$formatted_item}`
+
+monomorphize_unknown_cgu_collection_mode =
+    unknown codegen-item collection mode '{$mode}', falling back to 'lazy' mode
diff --git a/compiler/rustc_error_messages/locales/en-US/session.ftl b/compiler/rustc_error_messages/locales/en-US/session.ftl
index 76cae3c81e451..bffd720b39d0c 100644
--- a/compiler/rustc_error_messages/locales/en-US/session.ftl
+++ b/compiler/rustc_error_messages/locales/en-US/session.ftl
@@ -66,3 +66,5 @@ session_crate_name_invalid = crate names cannot start with a `-`, but `{$s}` has
 session_crate_name_empty = crate name must not be empty
 
 session_invalid_character_in_create_name = invalid character `{$character}` in crate name: `{$crate_name}`
+
+session_optimization_fuel_exhausted = optimization-fuel-exhausted: {$msg}
diff --git a/compiler/rustc_error_messages/src/lib.rs b/compiler/rustc_error_messages/src/lib.rs
index ff33ae7e8f224..05479d78a3d52 100644
--- a/compiler/rustc_error_messages/src/lib.rs
+++ b/compiler/rustc_error_messages/src/lib.rs
@@ -43,24 +43,25 @@ fluent_messages! {
     const_eval => "../locales/en-US/const_eval.ftl",
     driver => "../locales/en-US/driver.ftl",
     expand => "../locales/en-US/expand.ftl",
-    session => "../locales/en-US/session.ftl",
-    interface => "../locales/en-US/interface.ftl",
+    incremental => "../locales/en-US/incremental.ftl",
     infer => "../locales/en-US/infer.ftl",
+    interface => "../locales/en-US/interface.ftl",
     lint => "../locales/en-US/lint.ftl",
+    metadata => "../locales/en-US/metadata.ftl",
     middle => "../locales/en-US/middle.ftl",
+    mir_dataflow => "../locales/en-US/mir_dataflow.ftl",
     monomorphize => "../locales/en-US/monomorphize.ftl",
-    metadata => "../locales/en-US/metadata.ftl",
     parser => "../locales/en-US/parser.ftl",
     passes => "../locales/en-US/passes.ftl",
     plugin_impl => "../locales/en-US/plugin_impl.ftl",
     privacy => "../locales/en-US/privacy.ftl",
     query_system => "../locales/en-US/query_system.ftl",
-    trait_selection => "../locales/en-US/trait_selection.ftl",
     save_analysis => "../locales/en-US/save_analysis.ftl",
+    session => "../locales/en-US/session.ftl",
+    symbol_mangling => "../locales/en-US/symbol_mangling.ftl",
+    trait_selection => "../locales/en-US/trait_selection.ftl",
     ty_utils => "../locales/en-US/ty_utils.ftl",
     typeck => "../locales/en-US/typeck.ftl",
-    mir_dataflow => "../locales/en-US/mir_dataflow.ftl",
-    symbol_mangling => "../locales/en-US/symbol_mangling.ftl",
 }
 
 pub use fluent_generated::{self as fluent, DEFAULT_LOCALE_RESOURCES};
diff --git a/compiler/rustc_errors/Cargo.toml b/compiler/rustc_errors/Cargo.toml
index c36ca11fad6f2..dd96348153959 100644
--- a/compiler/rustc_errors/Cargo.toml
+++ b/compiler/rustc_errors/Cargo.toml
@@ -7,22 +7,22 @@ edition = "2021"
 doctest = false
 
 [dependencies]
-tracing = "0.1"
+annotate-snippets = "0.9"
+atty = "0.2"
+rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_error_messages = { path = "../rustc_error_messages" }
+rustc_hir = { path = "../rustc_hir" }
+rustc_lint_defs = { path = "../rustc_lint_defs" }
+rustc_macros = { path = "../rustc_macros" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_span = { path = "../rustc_span" }
-rustc_macros = { path = "../rustc_macros" }
-rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_target = { path = "../rustc_target" }
-rustc_hir = { path = "../rustc_hir" }
-rustc_lint_defs = { path = "../rustc_lint_defs" }
-unicode-width = "0.1.4"
-atty = "0.2"
-termcolor = "1.0"
-annotate-snippets = "0.9"
-termize = "0.1.1"
 serde = { version = "1.0.125", features = [ "derive" ] }
 serde_json = "1.0.59"
+termcolor = "1.0"
+termize = "0.1.1"
+tracing = "0.1"
+unicode-width = "0.1.4"
 
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3", features = [ "handleapi", "synchapi", "winbase" ] }
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index a52e95e92d55c..1de0f0e774267 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -43,6 +43,12 @@ pub trait IntoDiagnosticArg {
     fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static>;
 }
 
+impl<'a, T: Clone + IntoDiagnosticArg> IntoDiagnosticArg for &'a T {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        self.clone().into_diagnostic_arg()
+    }
+}
+
 pub struct DiagnosticArgFromDisplay<'a>(pub &'a dyn fmt::Display);
 
 impl IntoDiagnosticArg for DiagnosticArgFromDisplay<'_> {
@@ -94,7 +100,7 @@ into_diagnostic_arg_using_display!(
     MacroRulesNormalizedIdent,
     ParseIntError,
     StackProtector,
-    &TargetTriple,
+    TargetTriple,
     SplitDebuginfo
 );
 
diff --git a/compiler/rustc_errors/src/diagnostic_builder.rs b/compiler/rustc_errors/src/diagnostic_builder.rs
index b4ba65ca96d3b..ed4095fd354ae 100644
--- a/compiler/rustc_errors/src/diagnostic_builder.rs
+++ b/compiler/rustc_errors/src/diagnostic_builder.rs
@@ -242,6 +242,56 @@ impl EmissionGuarantee for () {
     }
 }
 
+/// Marker type which enables implementation of `create_note` and `emit_note` functions for
+/// note-without-error struct diagnostics.
+#[derive(Copy, Clone)]
+pub struct Noted;
+
+impl<'a> DiagnosticBuilder<'a, Noted> {
+    /// Convenience function for internal use, clients should use one of the
+    /// `struct_*` methods on [`Handler`].
+    pub(crate) fn new_note(handler: &'a Handler, message: impl Into<DiagnosticMessage>) -> Self {
+        let diagnostic = Diagnostic::new_with_code(Level::Note, None, message);
+        Self::new_diagnostic_note(handler, diagnostic)
+    }
+
+    /// Creates a new `DiagnosticBuilder` with an already constructed
+    /// diagnostic.
+    pub(crate) fn new_diagnostic_note(handler: &'a Handler, diagnostic: Diagnostic) -> Self {
+        debug!("Created new diagnostic");
+        Self {
+            inner: DiagnosticBuilderInner {
+                state: DiagnosticBuilderState::Emittable(handler),
+                diagnostic: Box::new(diagnostic),
+            },
+            _marker: PhantomData,
+        }
+    }
+}
+
+impl EmissionGuarantee for Noted {
+    fn diagnostic_builder_emit_producing_guarantee(db: &mut DiagnosticBuilder<'_, Self>) -> Self {
+        match db.inner.state {
+            // First `.emit()` call, the `&Handler` is still available.
+            DiagnosticBuilderState::Emittable(handler) => {
+                db.inner.state = DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation;
+                handler.emit_diagnostic(&mut db.inner.diagnostic);
+            }
+            // `.emit()` was previously called, disallowed from repeating it.
+            DiagnosticBuilderState::AlreadyEmittedOrDuringCancellation => {}
+        }
+
+        Noted
+    }
+
+    fn make_diagnostic_builder(
+        handler: &Handler,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, Self> {
+        DiagnosticBuilder::new_note(handler, msg)
+    }
+}
+
 impl<'a> DiagnosticBuilder<'a, !> {
     /// Convenience function for internal use, clients should use one of the
     /// `struct_*` methods on [`Handler`].
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 68971cebc3527..d4be147a99d06 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -374,7 +374,7 @@ pub use diagnostic::{
     AddToDiagnostic, DecorateLint, Diagnostic, DiagnosticArg, DiagnosticArgFromDisplay,
     DiagnosticArgValue, DiagnosticId, DiagnosticStyledString, IntoDiagnosticArg, SubDiagnostic,
 };
-pub use diagnostic_builder::{DiagnosticBuilder, EmissionGuarantee, LintDiagnosticBuilder};
+pub use diagnostic_builder::{DiagnosticBuilder, EmissionGuarantee, LintDiagnosticBuilder, Noted};
 use std::backtrace::Backtrace;
 
 /// A handler deals with errors and other compiler output.
@@ -941,6 +941,7 @@ impl Handler {
         self.emit_diag_at_span(Diagnostic::new(Bug, msg), span);
     }
 
+    #[rustc_lint_diagnostics]
     pub fn span_note_without_error(
         &self,
         span: impl Into<MultiSpan>,
@@ -949,6 +950,7 @@ impl Handler {
         self.emit_diag_at_span(Diagnostic::new(Note, msg), span);
     }
 
+    #[rustc_lint_diagnostics]
     pub fn span_note_diag(
         &self,
         span: Span,
@@ -960,19 +962,23 @@ impl Handler {
     }
 
     // NOTE: intentionally doesn't raise an error so rustc_codegen_ssa only reports fatal errors in the main thread
+    #[rustc_lint_diagnostics]
     pub fn fatal(&self, msg: impl Into<DiagnosticMessage>) -> FatalError {
         self.inner.borrow_mut().fatal(msg)
     }
 
+    #[rustc_lint_diagnostics]
     pub fn err(&self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed {
         self.inner.borrow_mut().err(msg)
     }
 
+    #[rustc_lint_diagnostics]
     pub fn warn(&self, msg: impl Into<DiagnosticMessage>) {
         let mut db = DiagnosticBuilder::new(self, Warning(None), msg);
         db.emit();
     }
 
+    #[rustc_lint_diagnostics]
     pub fn note_without_error(&self, msg: impl Into<DiagnosticMessage>) {
         DiagnosticBuilder::new(self, Note, msg).emit();
     }
diff --git a/compiler/rustc_incremental/src/assert_dep_graph.rs b/compiler/rustc_incremental/src/assert_dep_graph.rs
index 69e482ce854c0..95b48c38218d0 100644
--- a/compiler/rustc_incremental/src/assert_dep_graph.rs
+++ b/compiler/rustc_incremental/src/assert_dep_graph.rs
@@ -33,6 +33,7 @@
 //! fn baz() { foo(); }
 //! ```
 
+use crate::errors;
 use rustc_ast as ast;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::graph::implementation::{Direction, NodeIndex, INCOMING, OUTGOING};
@@ -133,12 +134,10 @@ impl<'tcx> IfThisChanged<'tcx> {
                     Some(n) => {
                         match DepNode::from_label_string(self.tcx, n.as_str(), def_path_hash) {
                             Ok(n) => n,
-                            Err(()) => {
-                                self.tcx.sess.span_fatal(
-                                    attr.span,
-                                    &format!("unrecognized DepNode variant {:?}", n),
-                                );
-                            }
+                            Err(()) => self.tcx.sess.emit_fatal(errors::UnrecognizedDepNode {
+                                span: attr.span,
+                                name: n,
+                            }),
                         }
                     }
                 };
@@ -149,16 +148,14 @@ impl<'tcx> IfThisChanged<'tcx> {
                     Some(n) => {
                         match DepNode::from_label_string(self.tcx, n.as_str(), def_path_hash) {
                             Ok(n) => n,
-                            Err(()) => {
-                                self.tcx.sess.span_fatal(
-                                    attr.span,
-                                    &format!("unrecognized DepNode variant {:?}", n),
-                                );
-                            }
+                            Err(()) => self.tcx.sess.emit_fatal(errors::UnrecognizedDepNode {
+                                span: attr.span,
+                                name: n,
+                            }),
                         }
                     }
                     None => {
-                        self.tcx.sess.span_fatal(attr.span, "missing DepNode variant");
+                        self.tcx.sess.emit_fatal(errors::MissingDepNode { span: attr.span });
                     }
                 };
                 self.then_this_would_need.push((
@@ -204,7 +201,7 @@ fn check_paths<'tcx>(tcx: TyCtxt<'tcx>, if_this_changed: &Sources, then_this_wou
     // Return early here so as not to construct the query, which is not cheap.
     if if_this_changed.is_empty() {
         for &(target_span, _, _, _) in then_this_would_need {
-            tcx.sess.span_err(target_span, "no `#[rustc_if_this_changed]` annotation detected");
+            tcx.sess.emit_err(errors::MissingIfThisChanged { span: target_span });
         }
         return;
     }
@@ -213,16 +210,13 @@ fn check_paths<'tcx>(tcx: TyCtxt<'tcx>, if_this_changed: &Sources, then_this_wou
             let dependents = query.transitive_predecessors(source_dep_node);
             for &(target_span, ref target_pass, _, ref target_dep_node) in then_this_would_need {
                 if !dependents.contains(&target_dep_node) {
-                    tcx.sess.span_err(
-                        target_span,
-                        &format!(
-                            "no path from `{}` to `{}`",
-                            tcx.def_path_str(source_def_id),
-                            target_pass
-                        ),
-                    );
+                    tcx.sess.emit_err(errors::NoPath {
+                        span: target_span,
+                        source: tcx.def_path_str(source_def_id),
+                        target: *target_pass,
+                    });
                 } else {
-                    tcx.sess.span_err(target_span, "OK");
+                    tcx.sess.emit_err(errors::Ok { span: target_span });
                 }
             }
         }
diff --git a/compiler/rustc_incremental/src/assert_module_sources.rs b/compiler/rustc_incremental/src/assert_module_sources.rs
index 89d419bc8e90f..2968a0e1203a9 100644
--- a/compiler/rustc_incremental/src/assert_module_sources.rs
+++ b/compiler/rustc_incremental/src/assert_module_sources.rs
@@ -22,6 +22,7 @@
 //! allows for doing a more fine-grained check to see if pre- or post-lto data
 //! was re-used.
 
+use crate::errors;
 use rustc_ast as ast;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir::def_id::LOCAL_CRATE;
@@ -66,10 +67,9 @@ impl<'tcx> AssertModuleSource<'tcx> {
                 sym::post_dash_lto => (CguReuse::PostLto, ComparisonKind::Exact),
                 sym::any => (CguReuse::PreLto, ComparisonKind::AtLeast),
                 other => {
-                    self.tcx.sess.span_fatal(
-                        attr.span,
-                        &format!("unknown cgu-reuse-kind `{}` specified", other),
-                    );
+                    self.tcx
+                        .sess
+                        .emit_fatal(errors::UnknownReuseKind { span: attr.span, kind: other });
                 }
             }
         } else {
@@ -77,10 +77,7 @@ impl<'tcx> AssertModuleSource<'tcx> {
         };
 
         if !self.tcx.sess.opts.unstable_opts.query_dep_graph {
-            self.tcx.sess.span_fatal(
-                attr.span,
-                "found CGU-reuse attribute but `-Zquery-dep-graph` was not specified",
-            );
+            self.tcx.sess.emit_fatal(errors::MissingQueryDepGraph { span: attr.span });
         }
 
         if !self.check_config(attr) {
@@ -92,13 +89,11 @@ impl<'tcx> AssertModuleSource<'tcx> {
         let crate_name = self.tcx.crate_name(LOCAL_CRATE).to_string();
 
         if !user_path.starts_with(&crate_name) {
-            let msg = format!(
-                "Found malformed codegen unit name `{}`. \
-                Codegen units names must always start with the name of the \
-                crate (`{}` in this case).",
-                user_path, crate_name
-            );
-            self.tcx.sess.span_fatal(attr.span, &msg);
+            self.tcx.sess.emit_fatal(errors::MalformedCguName {
+                span: attr.span,
+                user_path,
+                crate_name,
+            });
         }
 
         // Split of the "special suffix" if there is one.
@@ -125,15 +120,12 @@ impl<'tcx> AssertModuleSource<'tcx> {
             let mut cgu_names: Vec<&str> =
                 self.available_cgus.iter().map(|cgu| cgu.as_str()).collect();
             cgu_names.sort();
-            self.tcx.sess.span_err(
-                attr.span,
-                &format!(
-                    "no module named `{}` (mangled: {}). Available modules: {}",
-                    user_path,
-                    cgu_name,
-                    cgu_names.join(", ")
-                ),
-            );
+            self.tcx.sess.emit_err(errors::NoModuleNamed {
+                span: attr.span,
+                user_path,
+                cgu_name,
+                cgu_names: cgu_names.join(", "),
+            });
         }
 
         self.tcx.sess.cgu_reuse_tracker.set_expectation(
@@ -151,15 +143,15 @@ impl<'tcx> AssertModuleSource<'tcx> {
                 if let Some(value) = item.value_str() {
                     return value;
                 } else {
-                    self.tcx.sess.span_fatal(
-                        item.span(),
-                        &format!("associated value expected for `{}`", name),
-                    );
+                    self.tcx.sess.emit_fatal(errors::FieldAssociatedValueExpected {
+                        span: item.span(),
+                        name,
+                    });
                 }
             }
         }
 
-        self.tcx.sess.span_fatal(attr.span, &format!("no field `{}`", name));
+        self.tcx.sess.emit_fatal(errors::NoField { span: attr.span, name });
     }
 
     /// Scan for a `cfg="foo"` attribute and check whether we have a
diff --git a/compiler/rustc_incremental/src/errors.rs b/compiler/rustc_incremental/src/errors.rs
new file mode 100644
index 0000000000000..842bb4809251e
--- /dev/null
+++ b/compiler/rustc_incremental/src/errors.rs
@@ -0,0 +1,364 @@
+use rustc_macros::Diagnostic;
+use rustc_span::{symbol::Ident, Span, Symbol};
+use std::path::{Path, PathBuf};
+
+#[derive(Diagnostic)]
+#[diag(incremental::unrecognized_depnode)]
+pub struct UnrecognizedDepNode {
+    #[primary_span]
+    pub span: Span,
+    pub name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::missing_depnode)]
+pub struct MissingDepNode {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::missing_if_this_changed)]
+pub struct MissingIfThisChanged {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::ok)]
+pub struct Ok {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::no_path)]
+pub struct NoPath {
+    #[primary_span]
+    pub span: Span,
+    pub target: Symbol,
+    pub source: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::unknown_reuse_kind)]
+pub struct UnknownReuseKind {
+    #[primary_span]
+    pub span: Span,
+    pub kind: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::missing_query_depgraph)]
+pub struct MissingQueryDepGraph {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::malformed_cgu_name)]
+pub struct MalformedCguName {
+    #[primary_span]
+    pub span: Span,
+    pub user_path: String,
+    pub crate_name: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::no_module_named)]
+pub struct NoModuleNamed<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub user_path: &'a str,
+    pub cgu_name: Symbol,
+    pub cgu_names: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::field_associated_value_expected)]
+pub struct FieldAssociatedValueExpected {
+    #[primary_span]
+    pub span: Span,
+    pub name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::no_field)]
+pub struct NoField {
+    #[primary_span]
+    pub span: Span,
+    pub name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::assertion_auto)]
+pub struct AssertionAuto<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub name: &'a str,
+    pub e: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::undefined_clean_dirty_assertions_item)]
+pub struct UndefinedCleanDirtyItem {
+    #[primary_span]
+    pub span: Span,
+    pub kind: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::undefined_clean_dirty_assertions)]
+pub struct UndefinedCleanDirty {
+    #[primary_span]
+    pub span: Span,
+    pub kind: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::repeated_depnode_label)]
+pub struct RepeatedDepNodeLabel<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub label: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::unrecognized_depnode_label)]
+pub struct UnrecognizedDepNodeLabel<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub label: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::not_dirty)]
+pub struct NotDirty<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub dep_node_str: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::not_clean)]
+pub struct NotClean<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub dep_node_str: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::not_loaded)]
+pub struct NotLoaded<'a> {
+    #[primary_span]
+    pub span: Span,
+    pub dep_node_str: &'a str,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::unknown_item)]
+pub struct UnknownItem {
+    #[primary_span]
+    pub span: Span,
+    pub name: Symbol,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::no_cfg)]
+pub struct NoCfg {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::associated_value_expected_for)]
+pub struct AssociatedValueExpectedFor {
+    #[primary_span]
+    pub span: Span,
+    pub ident: Ident,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::associated_value_expected)]
+pub struct AssociatedValueExpected {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::unchecked_clean)]
+pub struct UncheckedClean {
+    #[primary_span]
+    pub span: Span,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::delete_old)]
+pub struct DeleteOld<'a> {
+    pub name: &'a str,
+    pub path: PathBuf,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::create_new)]
+pub struct CreateNew<'a> {
+    pub name: &'a str,
+    pub path: PathBuf,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::write_new)]
+pub struct WriteNew<'a> {
+    pub name: &'a str,
+    pub path: PathBuf,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::canonicalize_path)]
+pub struct CanonicalizePath {
+    pub path: PathBuf,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::create_incr_comp_dir)]
+pub struct CreateIncrCompDir<'a> {
+    pub tag: &'a str,
+    pub path: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::create_lock)]
+pub struct CreateLock<'a> {
+    pub lock_err: std::io::Error,
+    pub session_dir: &'a Path,
+    #[note(incremental::lock_unsupported)]
+    pub is_unsupported_lock: Option<()>,
+    #[help(incremental::cargo_help_1)]
+    #[help(incremental::cargo_help_2)]
+    pub is_cargo: Option<()>,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::delete_lock)]
+pub struct DeleteLock<'a> {
+    pub path: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::hard_link_failed)]
+pub struct HardLinkFailed<'a> {
+    pub path: &'a Path,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::delete_partial)]
+pub struct DeletePartial<'a> {
+    pub path: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::delete_full)]
+pub struct DeleteFull<'a> {
+    pub path: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::finalize)]
+pub struct Finalize<'a> {
+    pub path: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::invalid_gc_failed)]
+pub struct InvalidGcFailed<'a> {
+    pub path: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::finalized_gc_failed)]
+pub struct FinalizedGcFailed<'a> {
+    pub path: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::session_gc_failed)]
+pub struct SessionGcFailed<'a> {
+    pub path: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::assert_not_loaded)]
+pub struct AssertNotLoaded;
+
+#[derive(Diagnostic)]
+#[diag(incremental::assert_loaded)]
+pub struct AssertLoaded;
+
+#[derive(Diagnostic)]
+#[diag(incremental::delete_incompatible)]
+pub struct DeleteIncompatible {
+    pub path: PathBuf,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::load_dep_graph)]
+pub struct LoadDepGraph {
+    pub path: PathBuf,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::decode_incr_cache)]
+pub struct DecodeIncrCache {
+    pub err: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::write_dep_graph)]
+pub struct WriteDepGraph<'a> {
+    pub path: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::move_dep_graph)]
+pub struct MoveDepGraph<'a> {
+    pub from: &'a Path,
+    pub to: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::create_dep_graph)]
+pub struct CreateDepGraph<'a> {
+    pub path: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::copy_workproduct_to_cache)]
+pub struct CopyWorkProductToCache<'a> {
+    pub from: &'a Path,
+    pub to: &'a Path,
+    pub err: std::io::Error,
+}
+
+#[derive(Diagnostic)]
+#[diag(incremental::delete_workproduct)]
+pub struct DeleteWorkProduct<'a> {
+    pub path: &'a Path,
+    pub err: std::io::Error,
+}
diff --git a/compiler/rustc_incremental/src/lib.rs b/compiler/rustc_incremental/src/lib.rs
index 2c9e21f769fb1..51d5030562d12 100644
--- a/compiler/rustc_incremental/src/lib.rs
+++ b/compiler/rustc_incremental/src/lib.rs
@@ -3,8 +3,11 @@
 #![deny(missing_docs)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![cfg_attr(bootstrap, feature(let_else))]
+#![feature(never_type)]
 #![recursion_limit = "256"]
 #![allow(rustc::potential_query_instability)]
+#![deny(rustc::untranslatable_diagnostic)]
+#![deny(rustc::diagnostic_outside_of_impl)]
 
 #[macro_use]
 extern crate rustc_middle;
@@ -13,6 +16,7 @@ extern crate tracing;
 
 mod assert_dep_graph;
 pub mod assert_module_sources;
+mod errors;
 mod persist;
 
 use assert_dep_graph::assert_dep_graph;
diff --git a/compiler/rustc_incremental/src/persist/dirty_clean.rs b/compiler/rustc_incremental/src/persist/dirty_clean.rs
index 710c4a01b244f..4c815d69ff395 100644
--- a/compiler/rustc_incremental/src/persist/dirty_clean.rs
+++ b/compiler/rustc_incremental/src/persist/dirty_clean.rs
@@ -19,6 +19,7 @@
 //! Errors are reported if we are in the suitable configuration but
 //! the required condition is not met.
 
+use crate::errors;
 use rustc_ast::{self as ast, Attribute, NestedMetaItem};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir::def_id::LocalDefId;
@@ -198,11 +199,7 @@ impl<'tcx> DirtyCleanVisitor<'tcx> {
         let loaded_from_disk = self.loaded_from_disk(attr);
         for e in except.iter() {
             if !auto.remove(e) {
-                let msg = format!(
-                    "`except` specified DepNodes that can not be affected for \"{}\": \"{}\"",
-                    name, e
-                );
-                self.tcx.sess.span_fatal(attr.span, &msg);
+                self.tcx.sess.emit_fatal(errors::AssertionAuto { span: attr.span, name, e });
             }
         }
         Assertion { clean: auto, dirty: except, loaded_from_disk }
@@ -284,14 +281,10 @@ impl<'tcx> DirtyCleanVisitor<'tcx> {
                     // An implementation, eg `impl<A> Trait for Foo { .. }`
                     HirItem::Impl { .. } => ("ItemKind::Impl", LABELS_IMPL),
 
-                    _ => self.tcx.sess.span_fatal(
-                        attr.span,
-                        &format!(
-                            "clean/dirty auto-assertions not yet defined \
-                             for Node::Item.node={:?}",
-                            item.kind
-                        ),
-                    ),
+                    _ => self.tcx.sess.emit_fatal(errors::UndefinedCleanDirtyItem {
+                        span: attr.span,
+                        kind: format!("{:?}", item.kind),
+                    }),
                 }
             }
             HirNode::TraitItem(item) => match item.kind {
@@ -304,10 +297,10 @@ impl<'tcx> DirtyCleanVisitor<'tcx> {
                 ImplItemKind::Const(..) => ("NodeImplConst", LABELS_CONST_IN_IMPL),
                 ImplItemKind::TyAlias(..) => ("NodeImplType", LABELS_CONST_IN_IMPL),
             },
-            _ => self.tcx.sess.span_fatal(
-                attr.span,
-                &format!("clean/dirty auto-assertions not yet defined for {:?}", node),
-            ),
+            _ => self.tcx.sess.emit_fatal(errors::UndefinedCleanDirty {
+                span: attr.span,
+                kind: format!("{:?}", node),
+            }),
         };
         let labels =
             Labels::from_iter(labels.iter().flat_map(|s| s.iter().map(|l| (*l).to_string())));
@@ -320,16 +313,15 @@ impl<'tcx> DirtyCleanVisitor<'tcx> {
             let label = label.trim();
             if DepNode::has_label_string(label) {
                 if out.contains(label) {
-                    self.tcx.sess.span_fatal(
-                        item.span(),
-                        &format!("dep-node label `{}` is repeated", label),
-                    );
+                    self.tcx
+                        .sess
+                        .emit_fatal(errors::RepeatedDepNodeLabel { span: item.span(), label });
                 }
                 out.insert(label.to_string());
             } else {
                 self.tcx
                     .sess
-                    .span_fatal(item.span(), &format!("dep-node label `{}` not recognized", label));
+                    .emit_fatal(errors::UnrecognizedDepNodeLabel { span: item.span(), label });
             }
         }
         out
@@ -350,7 +342,7 @@ impl<'tcx> DirtyCleanVisitor<'tcx> {
             let dep_node_str = self.dep_node_str(&dep_node);
             self.tcx
                 .sess
-                .span_err(item_span, &format!("`{}` should be dirty but is not", dep_node_str));
+                .emit_err(errors::NotDirty { span: item_span, dep_node_str: &dep_node_str });
         }
     }
 
@@ -361,7 +353,7 @@ impl<'tcx> DirtyCleanVisitor<'tcx> {
             let dep_node_str = self.dep_node_str(&dep_node);
             self.tcx
                 .sess
-                .span_err(item_span, &format!("`{}` should be clean but is not", dep_node_str));
+                .emit_err(errors::NotClean { span: item_span, dep_node_str: &dep_node_str });
         }
     }
 
@@ -370,10 +362,9 @@ impl<'tcx> DirtyCleanVisitor<'tcx> {
 
         if !self.tcx.dep_graph.debug_was_loaded_from_disk(dep_node) {
             let dep_node_str = self.dep_node_str(&dep_node);
-            self.tcx.sess.span_err(
-                item_span,
-                &format!("`{}` should have been loaded from disk but it was not", dep_node_str),
-            );
+            self.tcx
+                .sess
+                .emit_err(errors::NotLoaded { span: item_span, dep_node_str: &dep_node_str });
         }
     }
 
@@ -414,12 +405,12 @@ fn check_config(tcx: TyCtxt<'_>, attr: &Attribute) -> bool {
             debug!("check_config: searching for cfg {:?}", value);
             cfg = Some(config.contains(&(value, None)));
         } else if !(item.has_name(EXCEPT) || item.has_name(LOADED_FROM_DISK)) {
-            tcx.sess.span_err(attr.span, &format!("unknown item `{}`", item.name_or_empty()));
+            tcx.sess.emit_err(errors::UnknownItem { span: attr.span, name: item.name_or_empty() });
         }
     }
 
     match cfg {
-        None => tcx.sess.span_fatal(attr.span, "no cfg attribute"),
+        None => tcx.sess.emit_fatal(errors::NoCfg { span: attr.span }),
         Some(c) => c,
     }
 }
@@ -428,13 +419,11 @@ fn expect_associated_value(tcx: TyCtxt<'_>, item: &NestedMetaItem) -> Symbol {
     if let Some(value) = item.value_str() {
         value
     } else {
-        let msg = if let Some(ident) = item.ident() {
-            format!("associated value expected for `{}`", ident)
+        if let Some(ident) = item.ident() {
+            tcx.sess.emit_fatal(errors::AssociatedValueExpectedFor { span: item.span(), ident });
         } else {
-            "expected an associated value".to_string()
-        };
-
-        tcx.sess.span_fatal(item.span(), &msg);
+            tcx.sess.emit_fatal(errors::AssociatedValueExpected { span: item.span() });
+        }
     }
 }
 
@@ -458,7 +447,7 @@ impl<'tcx> FindAllAttrs<'tcx> {
     fn report_unchecked_attrs(&self, mut checked_attrs: FxHashSet<ast::AttrId>) {
         for attr in &self.found_attrs {
             if !checked_attrs.contains(&attr.id) {
-                self.tcx.sess.span_err(attr.span, "found unchecked `#[rustc_clean]` attribute");
+                self.tcx.sess.emit_err(errors::UncheckedClean { span: attr.span });
                 checked_attrs.insert(attr.id);
             }
         }
diff --git a/compiler/rustc_incremental/src/persist/file_format.rs b/compiler/rustc_incremental/src/persist/file_format.rs
index 2dbd4b6bce85a..dc981c6179eeb 100644
--- a/compiler/rustc_incremental/src/persist/file_format.rs
+++ b/compiler/rustc_incremental/src/persist/file_format.rs
@@ -9,15 +9,15 @@
 //! compiler versions don't change frequently for the typical user, being
 //! conservative here practically has no downside.
 
-use std::env;
-use std::fs;
-use std::io::{self, Read};
-use std::path::{Path, PathBuf};
-
+use crate::errors;
 use rustc_data_structures::memmap::Mmap;
 use rustc_serialize::opaque::{FileEncodeResult, FileEncoder};
 use rustc_serialize::Encoder;
 use rustc_session::Session;
+use std::env;
+use std::fs;
+use std::io::{self, Read};
+use std::path::{Path, PathBuf};
 
 /// The first few bytes of files generated by incremental compilation.
 const FILE_MAGIC: &[u8] = b"RSIC";
@@ -60,12 +60,7 @@ where
         }
         Err(err) if err.kind() == io::ErrorKind::NotFound => (),
         Err(err) => {
-            sess.err(&format!(
-                "unable to delete old {} at `{}`: {}",
-                name,
-                path_buf.display(),
-                err
-            ));
+            sess.emit_err(errors::DeleteOld { name, path: path_buf, err });
             return;
         }
     }
@@ -73,7 +68,7 @@ where
     let mut encoder = match FileEncoder::new(&path_buf) {
         Ok(encoder) => encoder,
         Err(err) => {
-            sess.err(&format!("failed to create {} at `{}`: {}", name, path_buf.display(), err));
+            sess.emit_err(errors::CreateNew { name, path: path_buf, err });
             return;
         }
     };
@@ -90,7 +85,7 @@ where
             debug!("save: data written to disk successfully");
         }
         Err(err) => {
-            sess.err(&format!("failed to write {} to `{}`: {}", name, path_buf.display(), err));
+            sess.emit_err(errors::WriteNew { name, path: path_buf, err });
         }
     }
 }
diff --git a/compiler/rustc_incremental/src/persist/fs.rs b/compiler/rustc_incremental/src/persist/fs.rs
index 25c1b2e1c4387..b7fe3263adc9f 100644
--- a/compiler/rustc_incremental/src/persist/fs.rs
+++ b/compiler/rustc_incremental/src/persist/fs.rs
@@ -103,6 +103,7 @@
 //! unsupported file system and emit a warning in that case. This is not yet
 //! implemented.
 
+use crate::errors;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::svh::Svh;
 use rustc_data_structures::{base_n, flock};
@@ -225,12 +226,7 @@ pub fn prepare_session_directory(
     let crate_dir = match crate_dir.canonicalize() {
         Ok(v) => v,
         Err(err) => {
-            let reported = sess.err(&format!(
-                "incremental compilation: error canonicalizing path `{}`: {}",
-                crate_dir.display(),
-                err
-            ));
-            return Err(reported);
+            return Err(sess.emit_err(errors::CanonicalizePath { path: crate_dir, err }));
         }
     };
 
@@ -273,14 +269,7 @@ pub fn prepare_session_directory(
             debug!("successfully copied data from: {}", source_directory.display());
 
             if !allows_links {
-                sess.warn(&format!(
-                    "Hard linking files in the incremental \
-                                        compilation cache failed. Copying files \
-                                        instead. Consider moving the cache \
-                                        directory to a file system which supports \
-                                        hard linking in session dir `{}`",
-                    session_dir.display()
-                ));
+                sess.emit_warning(errors::HardLinkFailed { path: &session_dir });
             }
 
             sess.init_incr_comp_session(session_dir, directory_lock, true);
@@ -295,12 +284,7 @@ pub fn prepare_session_directory(
             // Try to remove the session directory we just allocated. We don't
             // know if there's any garbage in it from the failed copy action.
             if let Err(err) = safe_remove_dir_all(&session_dir) {
-                sess.warn(&format!(
-                    "Failed to delete partly initialized \
-                                    session dir `{}`: {}",
-                    session_dir.display(),
-                    err
-                ));
+                sess.emit_warning(errors::DeletePartial { path: &session_dir, err });
             }
 
             delete_session_dir_lock_file(sess, &lock_file_path);
@@ -332,12 +316,7 @@ pub fn finalize_session_directory(sess: &Session, svh: Svh) {
         );
 
         if let Err(err) = safe_remove_dir_all(&*incr_comp_session_dir) {
-            sess.warn(&format!(
-                "Error deleting incremental compilation \
-                                session directory `{}`: {}",
-                incr_comp_session_dir.display(),
-                err
-            ));
+            sess.emit_warning(errors::DeleteFull { path: &incr_comp_session_dir, err });
         }
 
         let lock_file_path = lock_file_path(&*incr_comp_session_dir);
@@ -380,12 +359,7 @@ pub fn finalize_session_directory(sess: &Session, svh: Svh) {
         }
         Err(e) => {
             // Warn about the error. However, no need to abort compilation now.
-            sess.warn(&format!(
-                "Error finalizing incremental compilation \
-                               session directory `{}`: {}",
-                incr_comp_session_dir.display(),
-                e
-            ));
+            sess.emit_warning(errors::Finalize { path: &incr_comp_session_dir, err: e });
 
             debug!("finalize_session_directory() - error, marking as invalid");
             // Drop the file lock, so we can garage collect
@@ -488,16 +462,7 @@ fn create_dir(sess: &Session, path: &Path, dir_tag: &str) -> Result<(), ErrorGua
             debug!("{} directory created successfully", dir_tag);
             Ok(())
         }
-        Err(err) => {
-            let reported = sess.err(&format!(
-                "Could not create incremental compilation {} \
-                               directory `{}`: {}",
-                dir_tag,
-                path.display(),
-                err
-            ));
-            Err(reported)
-        }
+        Err(err) => Err(sess.emit_err(errors::CreateIncrCompDir { tag: dir_tag, path, err })),
     }
 }
 
@@ -518,46 +483,20 @@ fn lock_directory(
         // the lock should be exclusive
         Ok(lock) => Ok((lock, lock_file_path)),
         Err(lock_err) => {
-            let mut err = sess.struct_err(&format!(
-                "incremental compilation: could not create \
-                 session directory lock file: {}",
-                lock_err
-            ));
-            if flock::Lock::error_unsupported(&lock_err) {
-                err.note(&format!(
-                    "the filesystem for the incremental path at {} \
-                     does not appear to support locking, consider changing the \
-                     incremental path to a filesystem that supports locking \
-                     or disable incremental compilation",
-                    session_dir.display()
-                ));
-                if std::env::var_os("CARGO").is_some() {
-                    err.help(
-                        "incremental compilation can be disabled by setting the \
-                         environment variable CARGO_INCREMENTAL=0 (see \
-                         https://doc.rust-lang.org/cargo/reference/profiles.html#incremental)",
-                    );
-                    err.help(
-                        "the entire build directory can be changed to a different \
-                        filesystem by setting the environment variable CARGO_TARGET_DIR \
-                        to a different path (see \
-                        https://doc.rust-lang.org/cargo/reference/config.html#buildtarget-dir)",
-                    );
-                }
-            }
-            Err(err.emit())
+            let is_unsupported_lock = flock::Lock::error_unsupported(&lock_err).then_some(());
+            Err(sess.emit_err(errors::CreateLock {
+                lock_err,
+                session_dir,
+                is_unsupported_lock,
+                is_cargo: std::env::var_os("CARGO").map(|_| ()),
+            }))
         }
     }
 }
 
 fn delete_session_dir_lock_file(sess: &Session, lock_file_path: &Path) {
     if let Err(err) = safe_remove_file(&lock_file_path) {
-        sess.warn(&format!(
-            "Error deleting lock file for incremental \
-                            compilation session directory `{}`: {}",
-            lock_file_path.display(),
-            err
-        ));
+        sess.emit_warning(errors::DeleteLock { path: lock_file_path, err });
     }
 }
 
@@ -774,12 +713,7 @@ pub fn garbage_collect_session_directories(sess: &Session) -> io::Result<()> {
         if !lock_file_to_session_dir.values().any(|dir| *dir == directory_name) {
             let path = crate_directory.join(directory_name);
             if let Err(err) = safe_remove_dir_all(&path) {
-                sess.warn(&format!(
-                    "Failed to garbage collect invalid incremental \
-                                    compilation session directory `{}`: {}",
-                    path.display(),
-                    err
-                ));
+                sess.emit_warning(errors::InvalidGcFailed { path: &path, err });
             }
         }
     }
@@ -885,12 +819,7 @@ pub fn garbage_collect_session_directories(sess: &Session) -> io::Result<()> {
         debug!("garbage_collect_session_directories() - deleting `{}`", path.display());
 
         if let Err(err) = safe_remove_dir_all(&path) {
-            sess.warn(&format!(
-                "Failed to garbage collect finalized incremental \
-                                compilation session directory `{}`: {}",
-                path.display(),
-                err
-            ));
+            sess.emit_warning(errors::FinalizedGcFailed { path: &path, err });
         } else {
             delete_session_dir_lock_file(sess, &lock_file_path(&path));
         }
@@ -907,11 +836,7 @@ fn delete_old(sess: &Session, path: &Path) {
     debug!("garbage_collect_session_directories() - deleting `{}`", path.display());
 
     if let Err(err) = safe_remove_dir_all(&path) {
-        sess.warn(&format!(
-            "Failed to garbage collect incremental compilation session directory `{}`: {}",
-            path.display(),
-            err
-        ));
+        sess.emit_warning(errors::SessionGcFailed { path: &path, err });
     } else {
         delete_session_dir_lock_file(sess, &lock_file_path(&path));
     }
diff --git a/compiler/rustc_incremental/src/persist/load.rs b/compiler/rustc_incremental/src/persist/load.rs
index 1c5fd91690230..d5097065dda2e 100644
--- a/compiler/rustc_incremental/src/persist/load.rs
+++ b/compiler/rustc_incremental/src/persist/load.rs
@@ -1,5 +1,6 @@
 //! Code to save/load the dep-graph from files.
 
+use crate::errors;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::memmap::Mmap;
 use rustc_middle::dep_graph::{SerializedDepGraph, WorkProduct, WorkProductId};
@@ -8,7 +9,7 @@ use rustc_serialize::opaque::MemDecoder;
 use rustc_serialize::Decodable;
 use rustc_session::config::IncrementalStateAssertion;
 use rustc_session::Session;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 
 use super::data::*;
 use super::file_format;
@@ -27,11 +28,10 @@ pub enum LoadResult<T> {
     },
     /// The file either didn't exist or was produced by an incompatible compiler version.
     DataOutOfDate,
-    /// An error occurred.
-    Error {
-        #[allow(missing_docs)]
-        message: String,
-    },
+    /// Loading the dep graph failed.
+    LoadDepGraph(PathBuf, std::io::Error),
+    /// Decoding loaded incremental cache failed.
+    DecodeIncrCache(Box<dyn std::any::Any + Send>),
 }
 
 impl<T: Default> LoadResult<T> {
@@ -40,36 +40,31 @@ impl<T: Default> LoadResult<T> {
         // Check for errors when using `-Zassert-incremental-state`
         match (sess.opts.assert_incr_state, &self) {
             (Some(IncrementalStateAssertion::NotLoaded), LoadResult::Ok { .. }) => {
-                sess.fatal(
-                    "We asserted that the incremental cache should not be loaded, \
-                         but it was loaded.",
-                );
+                sess.emit_fatal(errors::AssertNotLoaded);
             }
             (
                 Some(IncrementalStateAssertion::Loaded),
-                LoadResult::Error { .. } | LoadResult::DataOutOfDate,
+                LoadResult::LoadDepGraph(..)
+                | LoadResult::DecodeIncrCache(..)
+                | LoadResult::DataOutOfDate,
             ) => {
-                sess.fatal(
-                    "We asserted that an existing incremental cache directory should \
-                         be successfully loaded, but it was not.",
-                );
+                sess.emit_fatal(errors::AssertLoaded);
             }
             _ => {}
         };
 
         match self {
-            LoadResult::Error { message } => {
-                sess.warn(&message);
+            LoadResult::LoadDepGraph(path, err) => {
+                sess.emit_warning(errors::LoadDepGraph { path, err });
+                Default::default()
+            }
+            LoadResult::DecodeIncrCache(err) => {
+                sess.emit_warning(errors::DecodeIncrCache { err: format!("{err:?}") });
                 Default::default()
             }
             LoadResult::DataOutOfDate => {
                 if let Err(err) = delete_all_session_dir_contents(sess) {
-                    sess.err(&format!(
-                        "Failed to delete invalidated or incompatible \
-                         incremental compilation session directory contents `{}`: {}.",
-                        dep_graph_path(sess).display(),
-                        err
-                    ));
+                    sess.emit_err(errors::DeleteIncompatible { path: dep_graph_path(sess), err });
                 }
                 Default::default()
             }
@@ -90,9 +85,7 @@ fn load_data(
             // compiler version. Neither is an error.
             LoadResult::DataOutOfDate
         }
-        Err(err) => LoadResult::Error {
-            message: format!("could not load dep-graph from `{}`: {}", path.display(), err),
-        },
+        Err(err) => LoadResult::LoadDepGraph(path.to_path_buf(), err),
     }
 }
 
@@ -114,9 +107,9 @@ impl<T> MaybeAsync<LoadResult<T>> {
     pub fn open(self) -> LoadResult<T> {
         match self {
             MaybeAsync::Sync(result) => result,
-            MaybeAsync::Async(handle) => handle.join().unwrap_or_else(|e| LoadResult::Error {
-                message: format!("could not decode incremental cache: {:?}", e),
-            }),
+            MaybeAsync::Async(handle) => {
+                handle.join().unwrap_or_else(|e| LoadResult::DecodeIncrCache(e))
+            }
         }
     }
 }
@@ -185,7 +178,8 @@ pub fn load_dep_graph(sess: &Session) -> DepGraphFuture {
 
         match load_data(report_incremental_info, &path, nightly_build) {
             LoadResult::DataOutOfDate => LoadResult::DataOutOfDate,
-            LoadResult::Error { message } => LoadResult::Error { message },
+            LoadResult::LoadDepGraph(path, err) => LoadResult::LoadDepGraph(path, err),
+            LoadResult::DecodeIncrCache(err) => LoadResult::DecodeIncrCache(err),
             LoadResult::Ok { data: (bytes, start_pos) } => {
                 let mut decoder = MemDecoder::new(&bytes, start_pos);
                 let prev_commandline_args_hash = u64::decode(&mut decoder);
diff --git a/compiler/rustc_incremental/src/persist/save.rs b/compiler/rustc_incremental/src/persist/save.rs
index 710350314975c..7731351a80b7c 100644
--- a/compiler/rustc_incremental/src/persist/save.rs
+++ b/compiler/rustc_incremental/src/persist/save.rs
@@ -1,3 +1,4 @@
+use crate::errors;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::join;
 use rustc_middle::dep_graph::{DepGraph, SerializedDepGraph, WorkProduct, WorkProductId};
@@ -59,19 +60,14 @@ pub fn save_dep_graph(tcx: TyCtxt<'_>) {
             move || {
                 sess.time("incr_comp_persist_dep_graph", || {
                     if let Err(err) = tcx.dep_graph.encode(&tcx.sess.prof) {
-                        sess.err(&format!(
-                            "failed to write dependency graph to `{}`: {}",
-                            staging_dep_graph_path.display(),
-                            err
-                        ));
+                        sess.emit_err(errors::WriteDepGraph { path: &staging_dep_graph_path, err });
                     }
                     if let Err(err) = fs::rename(&staging_dep_graph_path, &dep_graph_path) {
-                        sess.err(&format!(
-                            "failed to move dependency graph from `{}` to `{}`: {}",
-                            staging_dep_graph_path.display(),
-                            dep_graph_path.display(),
-                            err
-                        ));
+                        sess.emit_err(errors::MoveDepGraph {
+                            from: &staging_dep_graph_path,
+                            to: &dep_graph_path,
+                            err,
+                        });
                     }
                 });
             },
@@ -163,11 +159,7 @@ pub fn build_dep_graph(
     let mut encoder = match FileEncoder::new(&path_buf) {
         Ok(encoder) => encoder,
         Err(err) => {
-            sess.err(&format!(
-                "failed to create dependency graph at `{}`: {}",
-                path_buf.display(),
-                err
-            ));
+            sess.emit_err(errors::CreateDepGraph { path: &path_buf, err });
             return None;
         }
     };
diff --git a/compiler/rustc_incremental/src/persist/work_product.rs b/compiler/rustc_incremental/src/persist/work_product.rs
index 2f1853c441eee..dc98fbeb0d166 100644
--- a/compiler/rustc_incremental/src/persist/work_product.rs
+++ b/compiler/rustc_incremental/src/persist/work_product.rs
@@ -2,6 +2,7 @@
 //!
 //! [work products]: WorkProduct
 
+use crate::errors;
 use crate::persist::fs::*;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_fs_util::link_or_copy;
@@ -28,12 +29,11 @@ pub fn copy_cgu_workproduct_to_incr_comp_cache_dir(
                 let _ = saved_files.insert(ext.to_string(), file_name);
             }
             Err(err) => {
-                sess.warn(&format!(
-                    "error copying object file `{}` to incremental directory as `{}`: {}",
-                    path.display(),
-                    path_in_incr_dir.display(),
-                    err
-                ));
+                sess.emit_warning(errors::CopyWorkProductToCache {
+                    from: &path,
+                    to: &path_in_incr_dir,
+                    err,
+                });
             }
         }
     }
@@ -49,11 +49,7 @@ pub fn delete_workproduct_files(sess: &Session, work_product: &WorkProduct) {
     for (_, path) in &work_product.saved_files {
         let path = in_incr_comp_dir_sess(sess, path);
         if let Err(err) = std_fs::remove_file(&path) {
-            sess.warn(&format!(
-                "file-system error deleting outdated file `{}`: {}",
-                path.display(),
-                err
-            ));
+            sess.emit_warning(errors::DeleteWorkProduct { path: &path, err });
         }
     }
 }
diff --git a/compiler/rustc_interface/Cargo.toml b/compiler/rustc_interface/Cargo.toml
index da4002d09ad02..39fad22635d8e 100644
--- a/compiler/rustc_interface/Cargo.toml
+++ b/compiler/rustc_interface/Cargo.toml
@@ -45,6 +45,7 @@ rustc_plugin_impl = { path = "../rustc_plugin_impl" }
 rustc_privacy = { path = "../rustc_privacy" }
 rustc_query_impl = { path = "../rustc_query_impl" }
 rustc_resolve = { path = "../rustc_resolve" }
+rustc_target = { path = "../rustc_target" }
 rustc_trait_selection = { path = "../rustc_trait_selection" }
 rustc_ty_utils = { path = "../rustc_ty_utils" }
 
@@ -54,9 +55,6 @@ libc = "0.2"
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3", features = ["libloaderapi"] }
 
-[dev-dependencies]
-rustc_target = { path = "../rustc_target" }
-
 [features]
 llvm = ['rustc_codegen_llvm']
 rustc_use_parallel_compiler = ['rayon', 'rustc-rayon-core', 'rustc_query_impl/rustc_use_parallel_compiler']
diff --git a/compiler/rustc_interface/src/errors.rs b/compiler/rustc_interface/src/errors.rs
index 097640f26c154..18f03735f34e1 100644
--- a/compiler/rustc_interface/src/errors.rs
+++ b/compiler/rustc_interface/src/errors.rs
@@ -1,5 +1,7 @@
 use rustc_macros::Diagnostic;
+use rustc_session::config::CrateType;
 use rustc_span::{Span, Symbol};
+use rustc_target::spec::TargetTriple;
 
 use std::io;
 use std::path::Path;
@@ -87,3 +89,22 @@ pub struct FailedWritingFile<'a> {
     pub path: &'a Path,
     pub error: io::Error,
 }
+
+#[derive(Diagnostic)]
+#[diag(interface::unsupported_crate_type_for_target)]
+pub struct UnsupportedCrateTypeForTarget<'a> {
+    pub crate_type: CrateType,
+    pub target_triple: &'a TargetTriple,
+}
+
+#[derive(Diagnostic)]
+#[diag(interface::multiple_output_types_adaption)]
+pub struct MultipleOutputTypesAdaption;
+
+#[derive(Diagnostic)]
+#[diag(interface::ignoring_extra_filename)]
+pub struct IgnoringExtraFilename;
+
+#[derive(Diagnostic)]
+#[diag(interface::ignoring_out_dir)]
+pub struct IgnoringOutDir;
diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs
index f7e70d355cf86..033a59ae8effd 100644
--- a/compiler/rustc_interface/src/util.rs
+++ b/compiler/rustc_interface/src/util.rs
@@ -1,3 +1,4 @@
+use crate::errors;
 use info;
 use libloading::Library;
 use rustc_ast as ast;
@@ -572,16 +573,15 @@ pub fn collect_crate_types(session: &Session, attrs: &[ast::Attribute]) -> Vec<C
     }
 
     base.retain(|crate_type| {
-        let res = !output::invalid_output_for_target(session, *crate_type);
-
-        if !res {
-            session.warn(&format!(
-                "dropping unsupported crate type `{}` for target `{}`",
-                *crate_type, session.opts.target_triple
-            ));
+        if output::invalid_output_for_target(session, *crate_type) {
+            session.emit_warning(errors::UnsupportedCrateTypeForTarget {
+                crate_type: *crate_type,
+                target_triple: &session.opts.target_triple,
+            });
+            false
+        } else {
+            true
         }
-
-        res
     });
 
     base
@@ -624,19 +624,16 @@ pub fn build_output_filenames(
             let unnamed_output_types =
                 sess.opts.output_types.values().filter(|a| a.is_none()).count();
             let ofile = if unnamed_output_types > 1 {
-                sess.warn(
-                    "due to multiple output types requested, the explicitly specified \
-                     output file name will be adapted for each output type",
-                );
+                sess.emit_warning(errors::MultipleOutputTypesAdaption);
                 None
             } else {
                 if !sess.opts.cg.extra_filename.is_empty() {
-                    sess.warn("ignoring -C extra-filename flag due to -o flag");
+                    sess.emit_warning(errors::IgnoringExtraFilename);
                 }
                 Some(out_file.clone())
             };
             if *odir != None {
-                sess.warn("ignoring --out-dir flag due to -o flag");
+                sess.emit_warning(errors::IgnoringOutDir);
             }
 
             OutputFilenames::new(
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index e773b3032aab8..258fb2e2f9f11 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -1133,9 +1133,13 @@ pub struct ProjectionTy<'tcx> {
 
 impl<'tcx> ProjectionTy<'tcx> {
     pub fn trait_def_id(&self, tcx: TyCtxt<'tcx>) -> DefId {
-        let parent = tcx.parent(self.item_def_id);
-        assert_eq!(tcx.def_kind(parent), DefKind::Trait);
-        parent
+        match tcx.def_kind(self.item_def_id) {
+            DefKind::AssocTy | DefKind::AssocConst => tcx.parent(self.item_def_id),
+            DefKind::ImplTraitPlaceholder => {
+                tcx.parent(tcx.impl_trait_in_trait_parent(self.item_def_id))
+            }
+            kind => bug!("unexpected DefKind in ProjectionTy: {kind:?}"),
+        }
     }
 
     /// Extracts the underlying trait reference and own substs from this projection.
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index f1a25a60d5292..d19b19212f767 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -201,7 +201,10 @@ use std::iter;
 use std::ops::Range;
 use std::path::PathBuf;
 
-use crate::errors::{LargeAssignmentsLint, RecursionLimit, RequiresLangItem, TypeLengthLimit};
+use crate::errors::{
+    EncounteredErrorWhileInstantiating, LargeAssignmentsLint, RecursionLimit, RequiresLangItem,
+    TypeLengthLimit,
+};
 
 #[derive(PartialEq)]
 pub enum MonoItemCollectionMode {
@@ -524,10 +527,10 @@ fn collect_items_rec<'tcx>(
         && starting_point.node.is_user_defined()
     {
         let formatted_item = with_no_trimmed_paths!(starting_point.node.to_string());
-        tcx.sess.span_note_without_error(
-            starting_point.span,
-            &format!("the above error was encountered while instantiating `{}`", formatted_item),
-        );
+        tcx.sess.emit_note(EncounteredErrorWhileInstantiating {
+            span: starting_point.span,
+            formatted_item,
+        });
     }
     inlining_map.lock_mut().record_accesses(starting_point.node, &neighbors.items);
 
diff --git a/compiler/rustc_monomorphize/src/errors.rs b/compiler/rustc_monomorphize/src/errors.rs
index cf6e18c013be8..b26345399b202 100644
--- a/compiler/rustc_monomorphize/src/errors.rs
+++ b/compiler/rustc_monomorphize/src/errors.rs
@@ -83,3 +83,17 @@ pub struct SymbolAlreadyDefined {
     pub span: Option<Span>,
     pub symbol: String,
 }
+
+#[derive(Diagnostic)]
+#[diag(monomorphize::encountered_error_while_instantiating)]
+pub struct EncounteredErrorWhileInstantiating {
+    #[primary_span]
+    pub span: Span,
+    pub formatted_item: String,
+}
+
+#[derive(Diagnostic)]
+#[diag(monomorphize::unknown_cgu_collection_mode)]
+pub struct UnknownCguCollectionMode<'a> {
+    pub mode: &'a str,
+}
diff --git a/compiler/rustc_monomorphize/src/partitioning/mod.rs b/compiler/rustc_monomorphize/src/partitioning/mod.rs
index 932edc6675f59..c124d5635900b 100644
--- a/compiler/rustc_monomorphize/src/partitioning/mod.rs
+++ b/compiler/rustc_monomorphize/src/partitioning/mod.rs
@@ -108,7 +108,7 @@ use rustc_span::symbol::Symbol;
 
 use crate::collector::InliningMap;
 use crate::collector::{self, MonoItemCollectionMode};
-use crate::errors::{SymbolAlreadyDefined, UnknownPartitionStrategy};
+use crate::errors::{SymbolAlreadyDefined, UnknownCguCollectionMode, UnknownPartitionStrategy};
 
 pub struct PartitioningCx<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
@@ -345,18 +345,13 @@ fn collect_and_partition_mono_items<'tcx>(
 ) -> (&'tcx DefIdSet, &'tcx [CodegenUnit<'tcx>]) {
     let collection_mode = match tcx.sess.opts.unstable_opts.print_mono_items {
         Some(ref s) => {
-            let mode_string = s.to_lowercase();
-            let mode_string = mode_string.trim();
-            if mode_string == "eager" {
+            let mode = s.to_lowercase();
+            let mode = mode.trim();
+            if mode == "eager" {
                 MonoItemCollectionMode::Eager
             } else {
-                if mode_string != "lazy" {
-                    let message = format!(
-                        "Unknown codegen-item collection mode '{}'. \
-                                           Falling back to 'lazy' mode.",
-                        mode_string
-                    );
-                    tcx.sess.warn(&message);
+                if mode != "lazy" {
+                    tcx.sess.emit_warning(UnknownCguCollectionMode { mode });
                 }
 
                 MonoItemCollectionMode::Lazy
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 70b470f3811d5..8591535845e71 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -25,7 +25,7 @@ use rustc_span::RealFileName;
 use rustc_span::SourceFileHashAlgorithm;
 
 use rustc_errors::emitter::HumanReadableErrorType;
-use rustc_errors::{ColorConfig, HandlerFlags};
+use rustc_errors::{ColorConfig, DiagnosticArgValue, HandlerFlags, IntoDiagnosticArg};
 
 use std::collections::btree_map::{
     Iter as BTreeMapIter, Keys as BTreeMapKeysIter, Values as BTreeMapValuesIter,
@@ -2640,6 +2640,12 @@ impl fmt::Display for CrateType {
     }
 }
 
+impl IntoDiagnosticArg for CrateType {
+    fn into_diagnostic_arg(self) -> DiagnosticArgValue<'static> {
+        self.to_string().into_diagnostic_arg()
+    }
+}
+
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub enum PpSourceMode {
     /// `-Zunpretty=normal`
diff --git a/compiler/rustc_session/src/errors.rs b/compiler/rustc_session/src/errors.rs
index e01dafe2102b8..38289aa58e18b 100644
--- a/compiler/rustc_session/src/errors.rs
+++ b/compiler/rustc_session/src/errors.rs
@@ -219,3 +219,9 @@ impl IntoDiagnostic<'_> for InvalidCharacterInCrateName<'_> {
         diag
     }
 }
+
+#[derive(Diagnostic)]
+#[diag(session::optimization_fuel_exhausted)]
+pub struct OptimisationFuelExhausted {
+    pub msg: String,
+}
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index b9202af2a6765..420189f67604f 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -12,7 +12,8 @@ use rustc_data_structures::sync::{Lock, Lrc};
 use rustc_errors::{emitter::SilentEmitter, ColorConfig, Handler};
 use rustc_errors::{
     fallback_fluent_bundle, Applicability, Diagnostic, DiagnosticBuilder, DiagnosticId,
-    DiagnosticMessage, EmissionGuarantee, ErrorGuaranteed, IntoDiagnostic, MultiSpan, StashKey,
+    DiagnosticMessage, EmissionGuarantee, ErrorGuaranteed, IntoDiagnostic, MultiSpan, Noted,
+    StashKey,
 };
 use rustc_feature::{find_feature_issue, GateIssue, UnstableFeatures};
 use rustc_span::edition::Edition;
@@ -364,6 +365,17 @@ impl ParseSess {
         self.create_warning(warning).emit()
     }
 
+    pub fn create_note<'a>(
+        &'a self,
+        note: impl IntoDiagnostic<'a, Noted>,
+    ) -> DiagnosticBuilder<'a, Noted> {
+        note.into_diagnostic(&self.span_diagnostic)
+    }
+
+    pub fn emit_note<'a>(&'a self, note: impl IntoDiagnostic<'a, Noted>) -> Noted {
+        self.create_note(note).emit()
+    }
+
     pub fn create_fatal<'a>(
         &'a self,
         fatal: impl IntoDiagnostic<'a, !>,
diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index 0142e98176633..0dca4516783c0 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/compiler/rustc_session/src/session.rs
@@ -4,8 +4,8 @@ pub use crate::code_stats::{DataTypeKind, FieldInfo, SizeKind, VariantInfo};
 use crate::config::{self, CrateType, InstrumentCoverage, OptLevel, OutputType, SwitchWithOptPath};
 use crate::errors::{
     CannotEnableCrtStaticLinux, CannotMixAndMatchSanitizers, LinkerPluginToWindowsNotSupported,
-    NotCircumventFeature, ProfileSampleUseFileDoesNotExist, ProfileUseFileDoesNotExist,
-    SanitizerCfiEnabled, SanitizerNotSupported, SanitizersNotSupported,
+    NotCircumventFeature, OptimisationFuelExhausted, ProfileSampleUseFileDoesNotExist,
+    ProfileUseFileDoesNotExist, SanitizerCfiEnabled, SanitizerNotSupported, SanitizersNotSupported,
     SplitDebugInfoUnstablePlatform, StackProtectorNotSupportedForTarget,
     TargetRequiresUnwindTables, UnstableVirtualFunctionElimination, UnsupportedDwarfVersion,
 };
@@ -28,7 +28,7 @@ use rustc_errors::json::JsonEmitter;
 use rustc_errors::registry::Registry;
 use rustc_errors::{
     error_code, fallback_fluent_bundle, DiagnosticBuilder, DiagnosticId, DiagnosticMessage,
-    ErrorGuaranteed, FluentBundle, IntoDiagnostic, LazyFallbackBundle, MultiSpan,
+    ErrorGuaranteed, FluentBundle, IntoDiagnostic, LazyFallbackBundle, MultiSpan, Noted,
 };
 use rustc_macros::HashStable_Generic;
 pub use rustc_span::def_id::StableCrateId;
@@ -500,6 +500,8 @@ impl Session {
         self.diagnostic().span_err_with_code(sp, msg, code)
     }
     #[rustc_lint_diagnostics]
+    #[allow(rustc::untranslatable_diagnostic)]
+    #[allow(rustc::diagnostic_outside_of_impl)]
     pub fn err(&self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed {
         self.diagnostic().err(msg)
     }
@@ -533,6 +535,15 @@ impl Session {
     pub fn emit_warning<'a>(&'a self, warning: impl IntoDiagnostic<'a, ()>) {
         self.parse_sess.emit_warning(warning)
     }
+    pub fn create_note<'a>(
+        &'a self,
+        note: impl IntoDiagnostic<'a, Noted>,
+    ) -> DiagnosticBuilder<'a, Noted> {
+        self.parse_sess.create_note(note)
+    }
+    pub fn emit_note<'a>(&'a self, note: impl IntoDiagnostic<'a, Noted>) -> Noted {
+        self.parse_sess.emit_note(note)
+    }
     pub fn create_fatal<'a>(
         &'a self,
         fatal: impl IntoDiagnostic<'a, !>,
@@ -576,11 +587,15 @@ impl Session {
             Err(ErrorGuaranteed::unchecked_claim_error_was_emitted())
         }
     }
+
+    #[rustc_lint_diagnostics]
     #[allow(rustc::untranslatable_diagnostic)]
     #[allow(rustc::diagnostic_outside_of_impl)]
     pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: impl Into<DiagnosticMessage>) {
         self.diagnostic().span_warn(sp, msg)
     }
+
+    #[rustc_lint_diagnostics]
     #[allow(rustc::untranslatable_diagnostic)]
     #[allow(rustc::diagnostic_outside_of_impl)]
     pub fn span_warn_with_code<S: Into<MultiSpan>>(
@@ -591,6 +606,10 @@ impl Session {
     ) {
         self.diagnostic().span_warn_with_code(sp, msg, code)
     }
+
+    #[rustc_lint_diagnostics]
+    #[allow(rustc::untranslatable_diagnostic)]
+    #[allow(rustc::diagnostic_outside_of_impl)]
     pub fn warn(&self, msg: impl Into<DiagnosticMessage>) {
         self.diagnostic().warn(msg)
     }
@@ -621,9 +640,15 @@ impl Session {
         self.diagnostic().delay_good_path_bug(msg)
     }
 
+    #[rustc_lint_diagnostics]
+    #[allow(rustc::untranslatable_diagnostic)]
+    #[allow(rustc::diagnostic_outside_of_impl)]
     pub fn note_without_error(&self, msg: impl Into<DiagnosticMessage>) {
         self.diagnostic().note_without_error(msg)
     }
+    #[rustc_lint_diagnostics]
+    #[allow(rustc::untranslatable_diagnostic)]
+    #[allow(rustc::diagnostic_outside_of_impl)]
     pub fn span_note_without_error<S: Into<MultiSpan>>(
         &self,
         sp: S,
@@ -631,6 +656,8 @@ impl Session {
     ) {
         self.diagnostic().span_note_without_error(sp, msg)
     }
+
+    #[rustc_lint_diagnostics]
     #[allow(rustc::untranslatable_diagnostic)]
     #[allow(rustc::diagnostic_outside_of_impl)]
     pub fn struct_note_without_error(
@@ -860,7 +887,7 @@ impl Session {
                         // We only call `msg` in case we can actually emit warnings.
                         // Otherwise, this could cause a `delay_good_path_bug` to
                         // trigger (issue #79546).
-                        self.warn(&format!("optimization-fuel-exhausted: {}", msg()));
+                        self.emit_warning(OptimisationFuelExhausted { msg: msg() });
                     }
                     fuel.out_of_fuel = true;
                 } else if fuel.remaining > 0 {
diff --git a/library/std/src/panicking.rs b/library/std/src/panicking.rs
index 38dcf6cbf7db7..4b07b393a2f5a 100644
--- a/library/std/src/panicking.rs
+++ b/library/std/src/panicking.rs
@@ -300,7 +300,7 @@ pub mod panic_count {
     thread_local! { static LOCAL_PANIC_COUNT: Cell<usize> = const { Cell::new(0) } }
 
     // Sum of panic counts from all threads. The purpose of this is to have
-    // a fast path in `is_zero` (which is used by `panicking`). In any particular
+    // a fast path in `count_is_zero` (which is used by `panicking`). In any particular
     // thread, if that thread currently views `GLOBAL_PANIC_COUNT` as being zero,
     // then `LOCAL_PANIC_COUNT` in that thread is zero. This invariant holds before
     // and after increase and decrease, but not necessarily during their execution.
@@ -369,7 +369,7 @@ pub mod panic_count {
     }
 
     // Slow path is in a separate function to reduce the amount of code
-    // inlined from `is_zero`.
+    // inlined from `count_is_zero`.
     #[inline(never)]
     #[cold]
     fn is_zero_slow_path() -> bool {
diff --git a/library/std/src/sys/windows/c.rs b/library/std/src/sys/windows/c.rs
index 89d0ab59be89f..c61a7e7d1e4ab 100644
--- a/library/std/src/sys/windows/c.rs
+++ b/library/std/src/sys/windows/c.rs
@@ -279,7 +279,6 @@ pub const STATUS_INVALID_PARAMETER: NTSTATUS = 0xc000000d_u32 as _;
 pub const STATUS_PENDING: NTSTATUS = 0x103 as _;
 pub const STATUS_END_OF_FILE: NTSTATUS = 0xC0000011_u32 as _;
 pub const STATUS_NOT_IMPLEMENTED: NTSTATUS = 0xC0000002_u32 as _;
-pub const STATUS_NOT_SUPPORTED: NTSTATUS = 0xC00000BB_u32 as _;
 
 // Equivalent to the `NT_SUCCESS` C preprocessor macro.
 // See: https://docs.microsoft.com/en-us/windows-hardware/drivers/kernel/using-ntstatus-values
@@ -289,6 +288,7 @@ pub fn nt_success(status: NTSTATUS) -> bool {
 
 // "RNG\0"
 pub const BCRYPT_RNG_ALGORITHM: &[u16] = &[b'R' as u16, b'N' as u16, b'G' as u16, 0];
+pub const BCRYPT_USE_SYSTEM_PREFERRED_RNG: DWORD = 0x00000002;
 
 #[repr(C)]
 pub struct UNICODE_STRING {
@@ -817,10 +817,6 @@ if #[cfg(not(target_vendor = "uwp"))] {
 
     #[link(name = "advapi32")]
     extern "system" {
-        // Forbidden when targeting UWP
-        #[link_name = "SystemFunction036"]
-        pub fn RtlGenRandom(RandomBuffer: *mut u8, RandomBufferLength: ULONG) -> BOOLEAN;
-
         // Allowed but unused by UWP
         pub fn OpenProcessToken(
             ProcessHandle: HANDLE,
diff --git a/library/std/src/sys/windows/rand.rs b/library/std/src/sys/windows/rand.rs
index d6cd8f8027162..b5a49489d3fb8 100644
--- a/library/std/src/sys/windows/rand.rs
+++ b/library/std/src/sys/windows/rand.rs
@@ -13,15 +13,12 @@
 //! but significant number of users to experience panics caused by a failure of
 //! this function. See [#94098].
 //!
-//! The current version changes this to use the `BCRYPT_RNG_ALG_HANDLE`
-//! [Pseudo-handle], which gets the default RNG algorithm without querying the
-//! system preference thus hopefully avoiding the previous issue.
-//! This is only supported on Windows 10+ so a fallback is used for older versions.
+//! The current version falls back to using `BCryptOpenAlgorithmProvider` if
+//! `BCRYPT_USE_SYSTEM_PREFERRED_RNG` fails for any reason.
 //!
 //! [#94098]: https://github.com/rust-lang/rust/issues/94098
 //! [`RtlGenRandom`]: https://docs.microsoft.com/en-us/windows/win32/api/ntsecapi/nf-ntsecapi-rtlgenrandom
 //! [`BCryptGenRandom`]: https://docs.microsoft.com/en-us/windows/win32/api/bcrypt/nf-bcrypt-bcryptgenrandom
-//! [Pseudo-handle]: https://docs.microsoft.com/en-us/windows/win32/seccng/cng-algorithm-pseudo-handles
 use crate::mem;
 use crate::ptr;
 use crate::sys::c;
@@ -33,37 +30,35 @@ use crate::sys::c;
 /// [`HashMap`]: crate::collections::HashMap
 /// [`RandomState`]: crate::collections::hash_map::RandomState
 pub fn hashmap_random_keys() -> (u64, u64) {
-    Rng::open().and_then(|rng| rng.gen_random_keys()).unwrap_or_else(fallback_rng)
+    Rng::SYSTEM.gen_random_keys().unwrap_or_else(fallback_rng)
 }
 
-struct Rng(c::BCRYPT_ALG_HANDLE);
+struct Rng {
+    algorithm: c::BCRYPT_ALG_HANDLE,
+    flags: u32,
+}
 impl Rng {
-    #[cfg(miri)]
-    fn open() -> Result<Self, c::NTSTATUS> {
-        const BCRYPT_RNG_ALG_HANDLE: c::BCRYPT_ALG_HANDLE = ptr::invalid_mut(0x81);
-        let _ = (
-            c::BCryptOpenAlgorithmProvider,
-            c::BCryptCloseAlgorithmProvider,
-            c::BCRYPT_RNG_ALGORITHM,
-            c::STATUS_NOT_SUPPORTED,
-        );
-        Ok(Self(BCRYPT_RNG_ALG_HANDLE))
+    const SYSTEM: Self = unsafe { Self::new(ptr::null_mut(), c::BCRYPT_USE_SYSTEM_PREFERRED_RNG) };
+
+    /// Create the RNG from an existing algorithm handle.
+    ///
+    /// # Safety
+    ///
+    /// The handle must either be null or a valid algorithm handle.
+    const unsafe fn new(algorithm: c::BCRYPT_ALG_HANDLE, flags: u32) -> Self {
+        Self { algorithm, flags }
     }
-    #[cfg(not(miri))]
-    // Open a handle to the RNG algorithm.
+
+    /// Open a handle to the RNG algorithm.
     fn open() -> Result<Self, c::NTSTATUS> {
         use crate::sync::atomic::AtomicPtr;
         use crate::sync::atomic::Ordering::{Acquire, Release};
-        const ERROR_VALUE: c::LPVOID = ptr::invalid_mut(usize::MAX);
 
         // An atomic is used so we don't need to reopen the handle every time.
         static HANDLE: AtomicPtr<crate::ffi::c_void> = AtomicPtr::new(ptr::null_mut());
 
         let mut handle = HANDLE.load(Acquire);
-        // We use a sentinel value to designate an error occurred last time.
-        if handle == ERROR_VALUE {
-            Err(c::STATUS_NOT_SUPPORTED)
-        } else if handle.is_null() {
+        if handle.is_null() {
             let status = unsafe {
                 c::BCryptOpenAlgorithmProvider(
                     &mut handle,
@@ -80,13 +75,12 @@ impl Rng {
                     unsafe { c::BCryptCloseAlgorithmProvider(handle, 0) };
                     handle = previous_handle;
                 }
-                Ok(Self(handle))
+                Ok(unsafe { Self::new(handle, 0) })
             } else {
-                HANDLE.store(ERROR_VALUE, Release);
                 Err(status)
             }
         } else {
-            Ok(Self(handle))
+            Ok(unsafe { Self::new(handle, 0) })
         }
     }
 
@@ -94,33 +88,19 @@ impl Rng {
         let mut v = (0, 0);
         let status = unsafe {
             let size = mem::size_of_val(&v).try_into().unwrap();
-            c::BCryptGenRandom(self.0, ptr::addr_of_mut!(v).cast(), size, 0)
+            c::BCryptGenRandom(self.algorithm, ptr::addr_of_mut!(v).cast(), size, self.flags)
         };
         if c::nt_success(status) { Ok(v) } else { Err(status) }
     }
 }
 
-/// Generate random numbers using the fallback RNG function (RtlGenRandom)
-#[cfg(not(target_vendor = "uwp"))]
+/// Generate random numbers using the fallback RNG function
 #[inline(never)]
 fn fallback_rng(rng_status: c::NTSTATUS) -> (u64, u64) {
-    let mut v = (0, 0);
-    let ret =
-        unsafe { c::RtlGenRandom(&mut v as *mut _ as *mut u8, mem::size_of_val(&v) as c::ULONG) };
-
-    if ret != 0 {
-        v
-    } else {
-        panic!(
-            "RNG broken: {rng_status:#x}, fallback RNG broken: {}",
-            crate::io::Error::last_os_error()
-        )
+    match Rng::open().and_then(|rng| rng.gen_random_keys()) {
+        Ok(keys) => keys,
+        Err(status) => {
+            panic!("RNG broken: {rng_status:#x}, fallback RNG broken: {status:#x}")
+        }
     }
 }
-
-/// We can't use RtlGenRandom with UWP, so there is no fallback
-#[cfg(target_vendor = "uwp")]
-#[inline(never)]
-fn fallback_rng(rng_status: c::NTSTATUS) -> (u64, u64) {
-    panic!("RNG broken: {rng_status:#x} fallback RNG broken: RtlGenRandom() not supported on UWP");
-}
diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs
index b7bc96cc86dac..563e67a326f19 100644
--- a/src/bootstrap/dist.rs
+++ b/src/bootstrap/dist.rs
@@ -1424,7 +1424,7 @@ impl Step for Extended {
 
         let xform = |p: &Path| {
             let mut contents = t!(fs::read_to_string(p));
-            for tool in &["rust-demangler", "rust-analyzer", "rustfmt"] {
+            for tool in &["rust-demangler"] {
                 if !built_tools.contains(tool) {
                     contents = filter(&contents, tool);
                 }
@@ -1465,7 +1465,8 @@ impl Step for Extended {
             prepare("rust-analysis");
             prepare("clippy");
             prepare("miri");
-            for tool in &["rust-docs", "rust-demangler", "rust-analyzer"] {
+            prepare("rust-analyzer");
+            for tool in &["rust-docs", "rust-demangler"] {
                 if built_tools.contains(tool) {
                     prepare(tool);
                 }
@@ -1525,7 +1526,8 @@ impl Step for Extended {
             prepare("rust-std");
             prepare("clippy");
             prepare("miri");
-            for tool in &["rust-demangler", "rust-analyzer"] {
+            prepare("rust-analyzer");
+            for tool in &["rust-demangler"] {
                 if built_tools.contains(tool) {
                     prepare(tool);
                 }
@@ -1609,25 +1611,23 @@ impl Step for Extended {
                     .arg("-out")
                     .arg(exe.join("StdGroup.wxs")),
             );
-            if built_tools.contains("rust-analyzer") {
-                builder.run(
-                    Command::new(&heat)
-                        .current_dir(&exe)
-                        .arg("dir")
-                        .arg("rust-analyzer")
-                        .args(&heat_flags)
-                        .arg("-cg")
-                        .arg("RustAnalyzerGroup")
-                        .arg("-dr")
-                        .arg("RustAnalyzer")
-                        .arg("-var")
-                        .arg("var.RustAnalyzerDir")
-                        .arg("-out")
-                        .arg(exe.join("RustAnalyzerGroup.wxs"))
-                        .arg("-t")
-                        .arg(etc.join("msi/remove-duplicates.xsl")),
-                );
-            }
+            builder.run(
+                Command::new(&heat)
+                    .current_dir(&exe)
+                    .arg("dir")
+                    .arg("rust-analyzer")
+                    .args(&heat_flags)
+                    .arg("-cg")
+                    .arg("RustAnalyzerGroup")
+                    .arg("-dr")
+                    .arg("RustAnalyzer")
+                    .arg("-var")
+                    .arg("var.RustAnalyzerDir")
+                    .arg("-out")
+                    .arg(exe.join("RustAnalyzerGroup.wxs"))
+                    .arg("-t")
+                    .arg(etc.join("msi/remove-duplicates.xsl")),
+            );
             builder.run(
                 Command::new(&heat)
                     .current_dir(&exe)
@@ -2026,6 +2026,7 @@ impl Step for RustDev {
             "llvm-dwp",
             "llvm-nm",
             "llvm-dwarfdump",
+            "llvm-dis",
         ] {
             tarball.add_file(src_bindir.join(exe(bin, target)), "bin", 0o755);
         }
diff --git a/src/bootstrap/download-ci-llvm-stamp b/src/bootstrap/download-ci-llvm-stamp
index 19504a51a584b..2e11cf19c3f6a 100644
--- a/src/bootstrap/download-ci-llvm-stamp
+++ b/src/bootstrap/download-ci-llvm-stamp
@@ -1,4 +1,4 @@
 Change this file to make users of the `download-ci-llvm` configuration download
 a new version of LLVM from CI, even if the LLVM submodule hasn’t changed.
 
-Last change is for: https://github.com/rust-lang/rust/pull/96867
+Last change is for: https://github.com/rust-lang/rust/pull/97550
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version b/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version
index 2774f8587f40e..142464bf22b42 100644
--- a/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version
@@ -1 +1 @@
-0.10.0
\ No newline at end of file
+0.11.0
\ No newline at end of file
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index e17165440d109..593c1c436b861 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -411,7 +411,7 @@ img {
 
 .sidebar {
 	font-size: 0.875rem;
-	width: 250px;
+	width: 200px;
 	min-width: 200px;
 	overflow-y: scroll;
 	position: sticky;
diff --git a/src/test/run-make/incremental-session-fail/Makefile b/src/test/run-make/incremental-session-fail/Makefile
index 0461bb926e76e..6ce1370927bc1 100644
--- a/src/test/run-make/incremental-session-fail/Makefile
+++ b/src/test/run-make/incremental-session-fail/Makefile
@@ -9,6 +9,6 @@ all:
 	touch $(SESSION_DIR)
 	# Check exit code is 1 for an error, and not 101 for ICE.
 	$(RUSTC) foo.rs --crate-type=rlib -C incremental=$(SESSION_DIR) > $(OUTPUT_FILE) 2>&1; [ $$? -eq 1 ]
-	$(CGREP) "Could not create incremental compilation crate directory" < $(OUTPUT_FILE)
+	$(CGREP) "could not create incremental compilation crate directory" < $(OUTPUT_FILE)
 	# -v tests are fragile, hopefully this text won't change
 	$(CGREP) -v "internal compiler error" < $(OUTPUT_FILE)
diff --git a/src/test/rustdoc-gui/check-stab-in-docblock.goml b/src/test/rustdoc-gui/check-stab-in-docblock.goml
index 7f965ada594d8..afe25195100c5 100644
--- a/src/test/rustdoc-gui/check-stab-in-docblock.goml
+++ b/src/test/rustdoc-gui/check-stab-in-docblock.goml
@@ -7,15 +7,21 @@ size: (786, 600)
 // Confirms that there 3 paragraphs.
 assert-count: (".top-doc .docblock p", 3)
 // Checking that there is no scrollable content.
+store-property: (clientHeight, ".top-doc .docblock p:nth-of-type(1)", "clientHeight")
+store-property: (clientWidth, ".top-doc .docblock p:nth-of-type(1)", "clientWidth")
 assert-property: (
     ".top-doc .docblock p:nth-of-type(1)",
-    {"scrollHeight": "120", "clientHeight": "120", "scrollWidth": "502", "clientWidth": "502"},
+    {"scrollHeight": |clientHeight|, "scrollWidth": |clientWidth|},
 )
+store-property: (clientHeight, ".top-doc .docblock p:nth-of-type(2)", "clientHeight")
+store-property: (clientWidth, ".top-doc .docblock p:nth-of-type(2)", "clientWidth")
 assert-property: (
     ".top-doc .docblock p:nth-of-type(2)",
-    {"scrollHeight": "48", "clientHeight": "48", "scrollWidth": "502", "clientWidth": "502"},
+    {"scrollHeight": |clientHeight|, "scrollWidth": |clientWidth|},
 )
+store-property: (clientHeight, ".top-doc .docblock p:nth-of-type(3)", "clientHeight")
+store-property: (clientWidth, ".top-doc .docblock p:nth-of-type(3)", "clientWidth")
 assert-property: (
     ".top-doc .docblock p:nth-of-type(3)",
-    {"scrollHeight": "48", "clientHeight": "48", "scrollWidth": "502", "clientWidth": "502"},
+    {"scrollHeight": |clientHeight|, "scrollWidth": |clientWidth|},
 )
diff --git a/src/test/rustdoc-gui/code-blocks-overflow.goml b/src/test/rustdoc-gui/code-blocks-overflow.goml
index f93f3f0aefc51..ee4dad444e932 100644
--- a/src/test/rustdoc-gui/code-blocks-overflow.goml
+++ b/src/test/rustdoc-gui/code-blocks-overflow.goml
@@ -5,4 +5,4 @@ size: (1080, 600)
 assert-count: (".docblock > .example-wrap", 2)
 assert: ".docblock > .example-wrap > .language-txt"
 assert: ".docblock > .example-wrap > .rust-example-rendered"
-assert-css: (".docblock > .example-wrap > pre", {"width": "785.25px", "overflow-x": "auto"}, ALL)
+assert-css: (".docblock > .example-wrap > pre", {"width": "796px", "overflow-x": "auto"}, ALL)
diff --git a/src/test/rustdoc-gui/docblock-table-overflow.goml b/src/test/rustdoc-gui/docblock-table-overflow.goml
index 7f97cf220cc55..ef0d37c902e09 100644
--- a/src/test/rustdoc-gui/docblock-table-overflow.goml
+++ b/src/test/rustdoc-gui/docblock-table-overflow.goml
@@ -4,7 +4,7 @@ goto: file://|DOC_PATH|/lib2/long_table/struct.Foo.html
 size: (1100, 800)
 // Logically, the ".docblock" and the "<p>" should have the same scroll width.
 compare-elements-property: (".top-doc .docblock", ".top-doc .docblock > p", ["scrollWidth"])
-assert-property: (".top-doc .docblock", {"scrollWidth": "801"})
+assert-property: (".top-doc .docblock", {"scrollWidth": "816"})
 // However, since there is overflow in the <table>, its scroll width is bigger.
 assert-property: (".top-doc .docblock table", {"scrollWidth": "1572"})
 
@@ -16,6 +16,6 @@ compare-elements-property: (
     "#implementations-list > details .docblock > p",
     ["scrollWidth"],
 )
-assert-property: ("#implementations-list > details .docblock", {"scrollWidth": "801"})
+assert-property: ("#implementations-list > details .docblock", {"scrollWidth": "816"})
 // However, since there is overflow in the <table>, its scroll width is bigger.
 assert-property: ("#implementations-list > details .docblock table", {"scrollWidth": "1572"})
diff --git a/src/test/rustdoc-gui/item-info-overflow.goml b/src/test/rustdoc-gui/item-info-overflow.goml
index 17478da4fea29..bc3addd33dd38 100644
--- a/src/test/rustdoc-gui/item-info-overflow.goml
+++ b/src/test/rustdoc-gui/item-info-overflow.goml
@@ -4,7 +4,7 @@ goto: file://|DOC_PATH|/lib2/struct.LongItemInfo.html
 size: (1200, 870)
 // Logically, the "item-decl" and the "item-info" should have the same scroll width.
 compare-elements-property: (".item-decl", ".item-info", ["scrollWidth"])
-assert-property: (".item-info", {"scrollWidth": "890"})
+assert-property: (".item-info", {"scrollWidth": "940"})
 // Just to be sure we're comparing the correct "item-info":
 assert-text: (
     ".item-info",
@@ -21,7 +21,7 @@ compare-elements-property: (
 )
 assert-property: (
     "#impl-SimpleTrait-for-LongItemInfo2 .item-info",
-    {"scrollWidth": "866"},
+    {"scrollWidth": "916"},
 )
 // Just to be sure we're comparing the correct "item-info":
 assert-text: (
diff --git a/src/test/rustdoc-gui/item-info.goml b/src/test/rustdoc-gui/item-info.goml
index 50c45b76bd630..8750d5c53606f 100644
--- a/src/test/rustdoc-gui/item-info.goml
+++ b/src/test/rustdoc-gui/item-info.goml
@@ -4,9 +4,9 @@ goto: file://|DOC_PATH|/lib2/struct.Foo.html
 // We set a fixed size so there is no chance of "random" resize.
 size: (1100, 800)
 // We check that ".item-info" is bigger than its content.
-assert-css: (".item-info", {"width": "790px"})
+assert-css: (".item-info", {"width": "840px"})
 assert-css: (".item-info .stab", {"width": "289px"})
-assert-position: (".item-info .stab", {"x": 295})
+assert-position: (".item-info .stab", {"x": 245})
 
 // Now we ensure that they're not rendered on the same line.
 goto: file://|DOC_PATH|/lib2/trait.Trait.html
diff --git a/src/test/rustdoc-gui/notable-trait.goml b/src/test/rustdoc-gui/notable-trait.goml
index 7eb00d825a5c3..20a129f9d9da6 100644
--- a/src/test/rustdoc-gui/notable-trait.goml
+++ b/src/test/rustdoc-gui/notable-trait.goml
@@ -18,11 +18,11 @@ compare-elements-position-false: (
 // The `i` should be *after* the type.
 assert-position: (
     "//*[@id='method.create_an_iterator_from_read']//a[text()='NotableStructWithLongName']",
-    {"x": 692},
+    {"x": 677},
 )
 assert-position: (
     "//*[@id='method.create_an_iterator_from_read']//*[@class='notable-traits']",
-    {"x": 966},
+    {"x": 951},
 )
 
 
diff --git a/src/test/rustdoc-gui/search-result-display.goml b/src/test/rustdoc-gui/search-result-display.goml
index efbbfb925bd3b..e33693e27eaf6 100644
--- a/src/test/rustdoc-gui/search-result-display.goml
+++ b/src/test/rustdoc-gui/search-result-display.goml
@@ -7,7 +7,7 @@ press-key: 'Enter'
 wait-for: "#crate-search"
 // The width is returned by "getComputedStyle" which returns the exact number instead of the
 // CSS rule which is "50%"...
-assert-css: (".search-results div.desc", {"width": "293px"})
+assert-css: (".search-results div.desc", {"width": "318px"})
 size: (600, 100)
 // As counter-intuitive as it may seem, in this width, the width is "100%", which is why
 // when computed it's larger.
diff --git a/src/test/rustdoc-gui/sidebar.goml b/src/test/rustdoc-gui/sidebar.goml
index 32fe3334f3644..ea7bcc669945a 100644
--- a/src/test/rustdoc-gui/sidebar.goml
+++ b/src/test/rustdoc-gui/sidebar.goml
@@ -1,5 +1,6 @@
 // Checks multiple things on the sidebar display (width of its elements, colors, etc).
 goto: file://|DOC_PATH|/test_docs/index.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 show-text: true
 local-storage: {"rustdoc-theme": "light"}
 // We reload the page so the local storage settings are being used.
@@ -39,11 +40,13 @@ assert-property: ("html", {"scrollTop": "0"})
 
 // We now go back to the crate page to click on the "lib2" crate link.
 goto: file://|DOC_PATH|/test_docs/index.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 assert-css: (".sidebar-elems .crate > ul > li:first-child > a", {"color": "rgb(53, 109, 164)"})
 click: ".sidebar-elems .crate > ul > li:first-child > a"
 
 // PAGE: lib2/index.html
 goto: file://|DOC_PATH|/lib2/index.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 assert-text: (".sidebar > .location", "Crate lib2")
 // We check that we have the crates list and that the "current" on is now "lib2".
 assert-text: (".sidebar-elems .crate > ul > li > a.current", "lib2")
@@ -65,11 +68,13 @@ assert-text: (".sidebar .sidebar-elems .location", "In lib2")
 assert-false: ".sidebar-elems > .crate"
 
 goto: ./module/index.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 assert-text: (".sidebar > .location", "Module module")
 // We check that we don't have the crate list.
 assert-false: ".sidebar-elems > .crate"
 
 goto: ./sub_module/sub_sub_module/index.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 assert-text: (".sidebar > .location", "Module sub_sub_module")
 // We check that we don't have the crate list.
 assert-false: ".sidebar-elems .crate"
@@ -78,11 +83,21 @@ assert-text: ("#functions + .item-table .item-left > a", "foo")
 
 // Links to trait implementations in the sidebar should not wrap even if they are long.
 goto: file://|DOC_PATH|/lib2/struct.HasALongTraitWithParams.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 assert-property: (".sidebar-elems section .block li > a", {"offsetHeight": 29})
 
 // Test that clicking on of the "In <module>" headings in the sidebar links to the
 // appropriate anchor in index.html.
 goto: file://|DOC_PATH|/test_docs/struct.Foo.html
+assert-property: (".sidebar", {"clientWidth": "200"})
 click: ".block.mod h3 a"
 // PAGE: index.html
 assert-css: ("#modules", {"background-color": "rgb(253, 255, 211)"})
+
+// Finally, assert that the `[+]/[−]` toggle doesn't affect sidebar width.
+click: "#toggle-all-docs"
+assert-text: ("#toggle-all-docs", "[+]")
+assert-property: (".sidebar", {"clientWidth": "200"})
+click: "#toggle-all-docs"
+assert-text: ("#toggle-all-docs", "[−]")
+assert-property: (".sidebar", {"clientWidth": "200"})
\ No newline at end of file
diff --git a/src/test/rustdoc-gui/type-declation-overflow.goml b/src/test/rustdoc-gui/type-declation-overflow.goml
index 9a46908f9333b..505874fa01070 100644
--- a/src/test/rustdoc-gui/type-declation-overflow.goml
+++ b/src/test/rustdoc-gui/type-declation-overflow.goml
@@ -15,7 +15,7 @@ assert-property: (".item-table .struct", {"offsetWidth": "684"})
 goto: file://|DOC_PATH|/lib2/too_long/type.ReallyLongTypeNameLongLongLong.html
 assert-property: ("body", {"scrollWidth": "1100"})
 // We now check that the section width hasn't grown because of it.
-assert-property: ("#main-content", {"scrollWidth": "825"})
+assert-property: ("#main-content", {"scrollWidth": "840"})
 // And now checking that it has scrollable content.
 assert-property: (".item-decl pre", {"scrollWidth": "1103"})
 
@@ -24,7 +24,7 @@ assert-property: (".item-decl pre", {"scrollWidth": "1103"})
 goto: file://|DOC_PATH|/lib2/too_long/constant.ReallyLongTypeNameLongLongLongConstBecauseWhyNotAConstRightGigaGigaSupraLong.html
 assert-property: ("body", {"scrollWidth": "1100"})
 // We now check that the section width hasn't grown because of it.
-assert-property: ("#main-content", {"scrollWidth": "825"})
+assert-property: ("#main-content", {"scrollWidth": "840"})
 // And now checking that it has scrollable content.
 assert-property: (".item-decl pre", {"scrollWidth": "950"})
 
@@ -32,6 +32,6 @@ assert-property: (".item-decl pre", {"scrollWidth": "950"})
 size: (600, 600)
 goto: file://|DOC_PATH|/lib2/too_long/struct.SuperIncrediblyLongLongLongLongLongLongLongGigaGigaGigaMegaLongLongLongStructName.html
 // It shouldn't have an overflow in the topbar either.
-assert-property: (".mobile-topbar .location", {"scrollWidth": "500"})
-assert-property: (".mobile-topbar .location", {"clientWidth": "500"})
+store-property: (scrollWidth, ".mobile-topbar .location", "scrollWidth")
+assert-property: (".mobile-topbar .location", {"clientWidth": |scrollWidth|})
 assert-css: (".mobile-topbar .location", {"overflow-x": "hidden"})
diff --git a/src/test/ui/impl-trait/in-trait/issue-102140.rs b/src/test/ui/impl-trait/in-trait/issue-102140.rs
new file mode 100644
index 0000000000000..be1e012acb185
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/issue-102140.rs
@@ -0,0 +1,30 @@
+#![feature(return_position_impl_trait_in_trait)]
+#![allow(incomplete_features)]
+
+trait Marker {}
+impl Marker for u32 {}
+
+trait MyTrait {
+    fn foo(&self) -> impl Marker
+    where
+        Self: Sized;
+}
+
+struct Outer;
+
+impl MyTrait for Outer {
+    fn foo(&self) -> impl Marker {
+        42
+    }
+}
+
+impl dyn MyTrait {
+    fn other(&self) -> impl Marker {
+        MyTrait::foo(&self)
+        //~^ ERROR the trait bound `&dyn MyTrait: MyTrait` is not satisfied
+        //~| ERROR the trait bound `&dyn MyTrait: MyTrait` is not satisfied
+        //~| ERROR the trait bound `&dyn MyTrait: MyTrait` is not satisfied
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/impl-trait/in-trait/issue-102140.stderr b/src/test/ui/impl-trait/in-trait/issue-102140.stderr
new file mode 100644
index 0000000000000..08602185f50ca
--- /dev/null
+++ b/src/test/ui/impl-trait/in-trait/issue-102140.stderr
@@ -0,0 +1,29 @@
+error[E0277]: the trait bound `&dyn MyTrait: MyTrait` is not satisfied
+  --> $DIR/issue-102140.rs:23:22
+   |
+LL |         MyTrait::foo(&self)
+   |         ------------ -^^^^
+   |         |            |
+   |         |            the trait `MyTrait` is not implemented for `&dyn MyTrait`
+   |         |            help: consider removing the leading `&`-reference
+   |         required by a bound introduced by this call
+
+error[E0277]: the trait bound `&dyn MyTrait: MyTrait` is not satisfied
+  --> $DIR/issue-102140.rs:23:9
+   |
+LL |         MyTrait::foo(&self)
+   |         ^^^^^^^^^^^^^^^^^^^ the trait `MyTrait` is not implemented for `&dyn MyTrait`
+   |
+   = help: the trait `MyTrait` is implemented for `Outer`
+
+error[E0277]: the trait bound `&dyn MyTrait: MyTrait` is not satisfied
+  --> $DIR/issue-102140.rs:23:9
+   |
+LL |         MyTrait::foo(&self)
+   |         ^^^^^^^^^^^^ the trait `MyTrait` is not implemented for `&dyn MyTrait`
+   |
+   = help: the trait `MyTrait` is implemented for `Outer`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0277`.