Auto merge of #136658 - matthiaskrgr:rollup-tg1vmex, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #133925 (disallow `repr()` on invalid items)
 - #136069 (Simplify slice indexing in next trait solver)
 - #136152 (Stabilize `map_many_mut` feature)
 - #136219 (Misc. `rustc_hir` cleanups 🧹)
 - #136580 (Couple of changes to run rustc in miri)
 - #136636 (Couple of minor cleanups to the diagnostic infrastructure)
 - #136645 (Clippy subtree update)

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

15 files changed, 119 insertions, 116 deletions

diff --git a/compiler/rustc_data_structures/src/memmap.rs b/compiler/rustc_data_structures/src/memmap.rs
index c7f66b2fee8..d64a5862f4e 100644
--- a/compiler/rustc_data_structures/src/memmap.rs
+++ b/compiler/rustc_data_structures/src/memmap.rs
@@ -3,13 +3,13 @@ use std::io;
 use std::ops::{Deref, DerefMut};
 
 /// A trivial wrapper for [`memmap2::Mmap`] (or `Vec<u8>` on WASM).
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(not(any(miri, target_arch = "wasm32")))]
 pub struct Mmap(memmap2::Mmap);
 
-#[cfg(target_arch = "wasm32")]
+#[cfg(any(miri, target_arch = "wasm32"))]
 pub struct Mmap(Vec<u8>);
 
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(not(any(miri, target_arch = "wasm32")))]
 impl Mmap {
     /// # Safety
     ///
@@ -29,7 +29,7 @@ impl Mmap {
     }
 }
 
-#[cfg(target_arch = "wasm32")]
+#[cfg(any(miri, target_arch = "wasm32"))]
 impl Mmap {
     #[inline]
     pub unsafe fn map(mut file: File) -> io::Result<Self> {
@@ -56,13 +56,13 @@ impl AsRef<[u8]> for Mmap {
     }
 }
 
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(not(any(miri, target_arch = "wasm32")))]
 pub struct MmapMut(memmap2::MmapMut);
 
-#[cfg(target_arch = "wasm32")]
+#[cfg(any(miri, target_arch = "wasm32"))]
 pub struct MmapMut(Vec<u8>);
 
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(not(any(miri, target_arch = "wasm32")))]
 impl MmapMut {
     #[inline]
     pub fn map_anon(len: usize) -> io::Result<Self> {
@@ -82,7 +82,7 @@ impl MmapMut {
     }
 }
 
-#[cfg(target_arch = "wasm32")]
+#[cfg(any(miri, target_arch = "wasm32"))]
 impl MmapMut {
     #[inline]
     pub fn map_anon(len: usize) -> io::Result<Self> {
diff --git a/compiler/rustc_data_structures/src/stack.rs b/compiler/rustc_data_structures/src/stack.rs
index 3d6d0003483..102b3640911 100644
--- a/compiler/rustc_data_structures/src/stack.rs
+++ b/compiler/rustc_data_structures/src/stack.rs
@@ -17,6 +17,18 @@ const STACK_PER_RECURSION: usize = 16 * 1024 * 1024; // 16MB
 ///
 /// Should not be sprinkled around carelessly, as it causes a little bit of overhead.
 #[inline]
+#[cfg(not(miri))]
 pub fn ensure_sufficient_stack<R>(f: impl FnOnce() -> R) -> R {
     stacker::maybe_grow(RED_ZONE, STACK_PER_RECURSION, f)
 }
+
+/// Grows the stack on demand to prevent stack overflow. Call this in strategic locations
+/// to "break up" recursive calls. E.g. almost any call to `visit_expr` or equivalent can benefit
+/// from this.
+///
+/// Should not be sprinkled around carelessly, as it causes a little bit of overhead.
+#[cfg(miri)]
+#[inline]
+pub fn ensure_sufficient_stack<R>(f: impl FnOnce() -> R) -> R {
+    f()
+}
diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index 6ea14d15c14..4c47ce93dd5 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -89,10 +89,10 @@ pub mod pretty;
 #[macro_use]
 mod print;
 mod session_diagnostics;
-#[cfg(all(unix, any(target_env = "gnu", target_os = "macos")))]
+#[cfg(all(not(miri), unix, any(target_env = "gnu", target_os = "macos")))]
 mod signal_handler;
 
-#[cfg(not(all(unix, any(target_env = "gnu", target_os = "macos"))))]
+#[cfg(not(all(not(miri), unix, any(target_env = "gnu", target_os = "macos"))))]
 mod signal_handler {
     /// On platforms which don't support our signal handler's requirements,
     /// simply use the default signal handler provided by std.
@@ -1024,7 +1024,7 @@ pub fn describe_flag_categories(early_dcx: &EarlyDiagCtxt, matches: &Matches) ->
     let wall = matches.opt_strs("W");
     if wall.iter().any(|x| *x == "all") {
         print_wall_help();
-        rustc_errors::FatalError.raise();
+        return true;
     }
 
     // Don't handle -W help here, because we might first load additional lints.
@@ -1474,7 +1474,7 @@ pub fn init_logger(early_dcx: &EarlyDiagCtxt, cfg: rustc_log::LoggerConfig) {
 /// Install our usual `ctrlc` handler, which sets [`rustc_const_eval::CTRL_C_RECEIVED`].
 /// Making this handler optional lets tools can install a different handler, if they wish.
 pub fn install_ctrlc_handler() {
-    #[cfg(not(target_family = "wasm"))]
+    #[cfg(all(not(miri), not(target_family = "wasm")))]
     ctrlc::set_handler(move || {
         // Indicate that we have been signaled to stop, then give the rest of the compiler a bit of
         // time to check CTRL_C_RECEIVED and run its own shutdown logic, but after a short amount
diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 8aa30db6d5a..15cf285e7ff 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -1765,7 +1765,7 @@ impl HumanEmitter {
 
                 let column_width = if let Some(width) = self.diagnostic_width {
                     width.saturating_sub(code_offset)
-                } else if self.ui_testing {
+                } else if self.ui_testing || cfg!(miri) {
                     DEFAULT_COLUMN_WIDTH
                 } else {
                     termize::dimensions()
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 7a02e0dd2f0..9af17db9a6e 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -1048,8 +1048,8 @@ impl<'a> DiagCtxtHandle<'a> {
     /// bad results, such as spurious/uninteresting additional errors -- when
     /// returning an error `Result` is difficult.
     pub fn abort_if_errors(&self) {
-        if self.has_errors().is_some() {
-            FatalError.raise();
+        if let Some(guar) = self.has_errors() {
+            guar.raise_fatal();
         }
     }
 
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 1c87a0eb1a7..e7b6a97c9d9 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -206,7 +206,7 @@ pub type UsePath<'hir> = Path<'hir, SmallVec<[Res; 3]>>;
 
 impl Path<'_> {
     pub fn is_global(&self) -> bool {
-        !self.segments.is_empty() && self.segments[0].ident.name == kw::PathRoot
+        self.segments.first().is_some_and(|segment| segment.ident.name == kw::PathRoot)
     }
 }
 
@@ -1061,10 +1061,7 @@ impl Attribute {
 
     pub fn value_lit(&self) -> Option<&MetaItemLit> {
         match &self.kind {
-            AttrKind::Normal(n) => match n.as_ref() {
-                AttrItem { args: AttrArgs::Eq { expr, .. }, .. } => Some(expr),
-                _ => None,
-            },
+            AttrKind::Normal(box AttrItem { args: AttrArgs::Eq { expr, .. }, .. }) => Some(expr),
             _ => None,
         }
     }
@@ -1077,12 +1074,9 @@ impl AttributeExt for Attribute {
 
     fn meta_item_list(&self) -> Option<ThinVec<ast::MetaItemInner>> {
         match &self.kind {
-            AttrKind::Normal(n) => match n.as_ref() {
-                AttrItem { args: AttrArgs::Delimited(d), .. } => {
-                    ast::MetaItemKind::list_from_tokens(d.tokens.clone())
-                }
-                _ => None,
-            },
+            AttrKind::Normal(box AttrItem { args: AttrArgs::Delimited(d), .. }) => {
+                ast::MetaItemKind::list_from_tokens(d.tokens.clone())
+            }
             _ => None,
         }
     }
@@ -1098,23 +1092,16 @@ impl AttributeExt for Attribute {
     /// For a single-segment attribute, returns its name; otherwise, returns `None`.
     fn ident(&self) -> Option<Ident> {
         match &self.kind {
-            AttrKind::Normal(n) => {
-                if let [ident] = n.path.segments.as_ref() {
-                    Some(*ident)
-                } else {
-                    None
-                }
-            }
-            AttrKind::DocComment(..) => None,
+            AttrKind::Normal(box AttrItem {
+                path: AttrPath { segments: box [ident], .. }, ..
+            }) => Some(*ident),
+            _ => None,
         }
     }
 
     fn path_matches(&self, name: &[Symbol]) -> bool {
         match &self.kind {
-            AttrKind::Normal(n) => {
-                n.path.segments.len() == name.len()
-                    && n.path.segments.iter().zip(name).all(|(s, n)| s.name == *n)
-            }
+            AttrKind::Normal(n) => n.path.segments.iter().map(|segment| &segment.name).eq(name),
             AttrKind::DocComment(..) => false,
         }
     }
@@ -1128,12 +1115,7 @@ impl AttributeExt for Attribute {
     }
 
     fn is_word(&self) -> bool {
-        match &self.kind {
-            AttrKind::Normal(n) => {
-                matches!(n.args, AttrArgs::Empty)
-            }
-            AttrKind::DocComment(..) => false,
-        }
+        matches!(self.kind, AttrKind::Normal(box AttrItem { args: AttrArgs::Empty, .. }))
     }
 
     fn ident_path(&self) -> Option<SmallVec<[Ident; 1]>> {
@@ -1990,7 +1972,7 @@ impl fmt::Display for ConstContext {
 }
 
 // NOTE: `IntoDiagArg` impl for `ConstContext` lives in `rustc_errors`
-// due to a cyclical dependency between hir that crate.
+// due to a cyclical dependency between hir and that crate.
 
 /// A literal.
 pub type Lit = Spanned<LitKind>;
@@ -3604,10 +3586,10 @@ impl<'hir> FnRetTy<'hir> {
     }
 
     pub fn is_suggestable_infer_ty(&self) -> Option<&'hir Ty<'hir>> {
-        if let Self::Return(ty) = self {
-            if ty.is_suggestable_infer_ty() {
-                return Some(*ty);
-            }
+        if let Self::Return(ty) = self
+            && ty.is_suggestable_infer_ty()
+        {
+            return Some(*ty);
         }
         None
     }
@@ -3976,11 +3958,11 @@ pub struct FnHeader {
 
 impl FnHeader {
     pub fn is_async(&self) -> bool {
-        matches!(&self.asyncness, IsAsync::Async(_))
+        matches!(self.asyncness, IsAsync::Async(_))
     }
 
     pub fn is_const(&self) -> bool {
-        matches!(&self.constness, Constness::Const)
+        matches!(self.constness, Constness::Const)
     }
 
     pub fn is_unsafe(&self) -> bool {
@@ -4076,16 +4058,16 @@ pub struct Impl<'hir> {
 
 impl ItemKind<'_> {
     pub fn generics(&self) -> Option<&Generics<'_>> {
-        Some(match *self {
-            ItemKind::Fn { ref generics, .. }
-            | ItemKind::TyAlias(_, ref generics)
-            | ItemKind::Const(_, ref generics, _)
-            | ItemKind::Enum(_, ref generics)
-            | ItemKind::Struct(_, ref generics)
-            | ItemKind::Union(_, ref generics)
-            | ItemKind::Trait(_, _, ref generics, _, _)
-            | ItemKind::TraitAlias(ref generics, _)
-            | ItemKind::Impl(Impl { ref generics, .. }) => generics,
+        Some(match self {
+            ItemKind::Fn { generics, .. }
+            | ItemKind::TyAlias(_, generics)
+            | ItemKind::Const(_, generics, _)
+            | ItemKind::Enum(_, generics)
+            | ItemKind::Struct(_, generics)
+            | ItemKind::Union(_, generics)
+            | ItemKind::Trait(_, _, generics, _, _)
+            | ItemKind::TraitAlias(generics, _)
+            | ItemKind::Impl(Impl { generics, .. }) => generics,
             _ => return None,
         })
     }
@@ -4484,16 +4466,14 @@ impl<'hir> Node<'hir> {
 
     /// Get a `hir::Impl` if the node is an impl block for the given `trait_def_id`.
     pub fn impl_block_of_trait(self, trait_def_id: DefId) -> Option<&'hir Impl<'hir>> {
-        match self {
-            Node::Item(Item { kind: ItemKind::Impl(impl_block), .. })
-                if impl_block
-                    .of_trait
-                    .and_then(|trait_ref| trait_ref.trait_def_id())
-                    .is_some_and(|trait_id| trait_id == trait_def_id) =>
-            {
-                Some(impl_block)
-            }
-            _ => None,
+        if let Node::Item(Item { kind: ItemKind::Impl(impl_block), .. }) = self
+            && let Some(trait_ref) = impl_block.of_trait
+            && let Some(trait_id) = trait_ref.trait_def_id()
+            && trait_id == trait_def_id
+        {
+            Some(impl_block)
+        } else {
+            None
         }
     }
 
diff --git a/compiler/rustc_hir/src/lib.rs b/compiler/rustc_hir/src/lib.rs
index 705c167e258..270d4fbec30 100644
--- a/compiler/rustc_hir/src/lib.rs
+++ b/compiler/rustc_hir/src/lib.rs
@@ -5,6 +5,7 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![feature(associated_type_defaults)]
+#![feature(box_patterns)]
 #![feature(closure_track_caller)]
 #![feature(debug_closure_helpers)]
 #![feature(exhaustive_patterns)]
diff --git a/compiler/rustc_interface/src/interface.rs b/compiler/rustc_interface/src/interface.rs
index 97fc542910c..b35703d8e73 100644
--- a/compiler/rustc_interface/src/interface.rs
+++ b/compiler/rustc_interface/src/interface.rs
@@ -442,7 +442,6 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
             locale_resources.push(codegen_backend.locale_resource());
 
             let mut sess = rustc_session::build_session(
-                early_dcx,
                 config.opts,
                 CompilerIO {
                     input: config.input,
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index fb69dd54811..46d6f37a91c 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -65,7 +65,6 @@ where
         static USING_INTERNAL_FEATURES: AtomicBool = AtomicBool::new(false);
 
         let sess = build_session(
-            early_dcx,
             sessopts,
             io,
             None,
diff --git a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
index 39e365806cb..a0d41110d96 100644
--- a/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/eval_ctxt/canonical.rs
@@ -453,13 +453,11 @@ where
 {
     // In case any fresh inference variables have been created between `state`
     // and the previous instantiation, extend `orig_values` for it.
-    assert!(orig_values.len() <= state.value.var_values.len());
-    for &arg in &state.value.var_values.var_values.as_slice()
-        [orig_values.len()..state.value.var_values.len()]
-    {
-        let unconstrained = delegate.fresh_var_for_kind_with_span(arg, span);
-        orig_values.push(unconstrained);
-    }
+    orig_values.extend(
+        state.value.var_values.var_values.as_slice()[orig_values.len()..]
+            .iter()
+            .map(|&arg| delegate.fresh_var_for_kind_with_span(arg, span)),
+    );
 
     let instantiation =
         EvalCtxt::compute_query_response_instantiation_values(delegate, orig_values, &state, span);
diff --git a/compiler/rustc_parse/src/parser/tests.rs b/compiler/rustc_parse/src/parser/tests.rs
index 76b7dc0e48a..8b8c81a77a0 100644
--- a/compiler/rustc_parse/src/parser/tests.rs
+++ b/compiler/rustc_parse/src/parser/tests.rs
@@ -26,7 +26,7 @@ use crate::parser::{ForceCollect, Parser};
 use crate::{new_parser_from_source_str, source_str_to_stream, unwrap_or_emit_fatal};
 
 fn psess() -> ParseSess {
-    ParseSess::new(vec![crate::DEFAULT_LOCALE_RESOURCE, crate::DEFAULT_LOCALE_RESOURCE])
+    ParseSess::new(vec![crate::DEFAULT_LOCALE_RESOURCE])
 }
 
 /// Map string to parser (via tts).
@@ -41,10 +41,8 @@ fn string_to_parser(psess: &ParseSess, source_str: String) -> Parser<'_> {
 fn create_test_handler(theme: OutputTheme) -> (DiagCtxt, Arc<SourceMap>, Arc<Mutex<Vec<u8>>>) {
     let output = Arc::new(Mutex::new(Vec::new()));
     let source_map = Arc::new(SourceMap::new(FilePathMapping::empty()));
-    let fallback_bundle = rustc_errors::fallback_fluent_bundle(
-        vec![crate::DEFAULT_LOCALE_RESOURCE, crate::DEFAULT_LOCALE_RESOURCE],
-        false,
-    );
+    let fallback_bundle =
+        rustc_errors::fallback_fluent_bundle(vec![crate::DEFAULT_LOCALE_RESOURCE], false);
     let mut emitter = HumanEmitter::new(Box::new(Shared { data: output.clone() }), fallback_bundle)
         .sm(Some(source_map.clone()))
         .diagnostic_width(Some(140));
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 837da6e7724..4c683c82b6c 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -1851,6 +1851,34 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         let mut is_simd = false;
         let mut is_transparent = false;
 
+        // catch `repr()` with no arguments, applied to an item (i.e. not `#![repr()]`)
+        if hints.is_empty() && item.is_some() {
+            for attr in attrs.iter().filter(|attr| attr.has_name(sym::repr)) {
+                match target {
+                    Target::Struct | Target::Union | Target::Enum => {}
+                    Target::Fn | Target::Method(_) => {
+                        feature_err(
+                            &self.tcx.sess,
+                            sym::fn_align,
+                            attr.span,
+                            fluent::passes_repr_align_function,
+                        )
+                        .emit();
+                    }
+                    _ => {
+                        self.dcx().emit_err(
+                            errors::AttrApplication::StructEnumFunctionMethodUnion {
+                                hint_span: attr.span,
+                                span,
+                            },
+                        );
+                    }
+                }
+            }
+
+            return;
+        }
+
         for hint in &hints {
             if !hint.is_meta_item() {
                 self.dcx().emit_err(errors::ReprIdent { span: hint.span() });
@@ -1883,24 +1911,19 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     }
                 }
                 sym::align => {
-                    if let (Target::Fn | Target::Method(MethodKind::Inherent), false) =
-                        (target, self.tcx.features().fn_align())
-                    {
-                        feature_err(
-                            &self.tcx.sess,
-                            sym::fn_align,
-                            hint.span(),
-                            fluent::passes_repr_align_function,
-                        )
-                        .emit();
-                    }
-
                     match target {
-                        Target::Struct
-                        | Target::Union
-                        | Target::Enum
-                        | Target::Fn
-                        | Target::Method(_) => {}
+                        Target::Struct | Target::Union | Target::Enum => {}
+                        Target::Fn | Target::Method(_) => {
+                            if !self.tcx.features().fn_align() {
+                                feature_err(
+                                    &self.tcx.sess,
+                                    sym::fn_align,
+                                    hint.span(),
+                                    fluent::passes_repr_align_function,
+                                )
+                                .emit();
+                            }
+                        }
                         _ => {
                             self.dcx().emit_err(
                                 errors::AttrApplication::StructEnumFunctionMethodUnion {
diff --git a/compiler/rustc_session/src/config/cfg.rs b/compiler/rustc_session/src/config/cfg.rs
index 52920e0372e..4762281c329 100644
--- a/compiler/rustc_session/src/config/cfg.rs
+++ b/compiler/rustc_session/src/config/cfg.rs
@@ -427,7 +427,7 @@ impl CheckCfg {
                     Some(values_target_os),
                     Some(values_target_pointer_width),
                     Some(values_target_vendor),
-                ] = self.expecteds.get_many_mut(VALUES)
+                ] = self.expecteds.get_disjoint_mut(VALUES)
                 else {
                     panic!("unable to get all the check-cfg values buckets");
                 };
diff --git a/compiler/rustc_session/src/lib.rs b/compiler/rustc_session/src/lib.rs
index 924350b8cbc..112adde3740 100644
--- a/compiler/rustc_session/src/lib.rs
+++ b/compiler/rustc_session/src/lib.rs
@@ -2,7 +2,6 @@
 #![allow(internal_features)]
 #![feature(iter_intersperse)]
 #![feature(let_chains)]
-#![feature(map_many_mut)]
 #![feature(rustc_attrs)]
 // To generate CodegenOptionsTargetModifiers and UnstableOptionsTargetModifiers enums
 // with macro_rules, it is necessary to use recursive mechanic ("Incremental TT Munchers").
diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index 1a3e80d6659..0851e859a0f 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/compiler/rustc_session/src/session.rs
@@ -965,7 +965,6 @@ fn default_emitter(
 #[allow(rustc::bad_opt_access)]
 #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub fn build_session(
-    early_dcx: EarlyDiagCtxt,
     sopts: config::Options,
     io: CompilerIO,
     bundle: Option<Arc<rustc_errors::FluentBundle>>,
@@ -990,14 +989,6 @@ pub fn build_session(
     let cap_lints_allow = sopts.lint_cap.is_some_and(|cap| cap == lint::Allow);
     let can_emit_warnings = !(warnings_allow || cap_lints_allow);
 
-    let host_triple = TargetTuple::from_tuple(config::host_tuple());
-    let (host, target_warnings) = Target::search(&host_triple, &sysroot).unwrap_or_else(|e| {
-        early_dcx.early_fatal(format!("Error loading host specification: {e}"))
-    });
-    for warning in target_warnings.warning_messages() {
-        early_dcx.early_warn(warning)
-    }
-
     let fallback_bundle = fallback_fluent_bundle(
         fluent_resources,
         sopts.unstable_opts.translate_directionality_markers,
@@ -1012,9 +1003,12 @@ pub fn build_session(
         dcx = dcx.with_ice_file(ice_file);
     }
 
-    // Now that the proper handler has been constructed, drop early_dcx to
-    // prevent accidental use.
-    drop(early_dcx);
+    let host_triple = TargetTuple::from_tuple(config::host_tuple());
+    let (host, target_warnings) = Target::search(&host_triple, &sysroot)
+        .unwrap_or_else(|e| dcx.handle().fatal(format!("Error loading host specification: {e}")));
+    for warning in target_warnings.warning_messages() {
+        dcx.handle().warn(warning)
+    }
 
     let self_profiler = if let SwitchWithOptPath::Enabled(ref d) = sopts.unstable_opts.self_profile
     {