Auto merge of #127133 - matthiaskrgr:rollup-jxkp3yf, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - #123237 (Various rustc_codegen_ssa cleanups)
 - #126960 (Improve error message in tidy)
 - #127002 (Implement `x perf` as a separate tool)
 - #127081 (Add a run-make test that LLD is not being used by default on the x64 beta/stable channel)
 - #127106 (Improve unsafe extern blocks diagnostics)
 - #127110 (Fix a error suggestion for E0121 when using placeholder _ as return types on function signature.)
 - #127114 (fix: prefer `(*p).clone` to `p.clone` if the `p` is a raw pointer)
 - #127118 (Show `used attribute`'s kind for user when find it isn't applied to a `static` variable.)
 - #127122 (Remove uneccessary condition in `div_ceil`)

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

57 files changed, 632 insertions, 272 deletions

diff --git a/Cargo.lock b/Cargo.lock
index f6293f9626e..c7d2857b463 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3462,6 +3462,13 @@ dependencies = [
 ]
 
 [[package]]
+name = "rustc-perf-wrapper"
+version = "0.1.0"
+dependencies = [
+ "clap",
+]
+
+[[package]]
 name = "rustc-rayon"
 version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/Cargo.toml b/Cargo.toml
index c17ea99d037..93c520b0d68 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,6 +44,7 @@ members = [
   "src/tools/rustdoc-gui-test",
   "src/tools/opt-dist",
   "src/tools/coverage-dump",
+  "src/tools/rustc-perf-wrapper",
 ]
 
 exclude = [
diff --git a/compiler/rustc_ast_passes/src/ast_validation.rs b/compiler/rustc_ast_passes/src/ast_validation.rs
index 79ee5c0e8e2..022f953c6e7 100644
--- a/compiler/rustc_ast_passes/src/ast_validation.rs
+++ b/compiler/rustc_ast_passes/src/ast_validation.rs
@@ -469,13 +469,18 @@ impl<'a> AstValidator<'a> {
     fn check_item_safety(&self, span: Span, safety: Safety) {
         match self.extern_mod_safety {
             Some(extern_safety) => {
-                if matches!(safety, Safety::Unsafe(_) | Safety::Safe(_))
-                    && (extern_safety == Safety::Default || !self.features.unsafe_extern_blocks)
-                {
-                    self.dcx().emit_err(errors::InvalidSafetyOnExtern {
-                        item_span: span,
-                        block: self.current_extern_span().shrink_to_lo(),
-                    });
+                if matches!(safety, Safety::Unsafe(_) | Safety::Safe(_)) {
+                    if extern_safety == Safety::Default {
+                        self.dcx().emit_err(errors::InvalidSafetyOnExtern {
+                            item_span: span,
+                            block: Some(self.current_extern_span().shrink_to_lo()),
+                        });
+                    } else if !self.features.unsafe_extern_blocks {
+                        self.dcx().emit_err(errors::InvalidSafetyOnExtern {
+                            item_span: span,
+                            block: None,
+                        });
+                    }
                 }
             }
             None => {
@@ -1098,7 +1103,15 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
                             }
                         }
                     } else if let &Safety::Unsafe(span) = safety {
-                        this.dcx().emit_err(errors::UnsafeItem { span, kind: "extern block" });
+                        let mut diag = this
+                            .dcx()
+                            .create_err(errors::UnsafeItem { span, kind: "extern block" });
+                        rustc_session::parse::add_feature_diagnostics(
+                            &mut diag,
+                            self.session,
+                            sym::unsafe_extern_blocks,
+                        );
+                        diag.emit();
                     }
 
                     if abi.is_none() {
diff --git a/compiler/rustc_ast_passes/src/errors.rs b/compiler/rustc_ast_passes/src/errors.rs
index 965d8fac712..bfb90476450 100644
--- a/compiler/rustc_ast_passes/src/errors.rs
+++ b/compiler/rustc_ast_passes/src/errors.rs
@@ -222,7 +222,7 @@ pub struct InvalidSafetyOnExtern {
     #[primary_span]
     pub item_span: Span,
     #[suggestion(code = "unsafe ", applicability = "machine-applicable", style = "verbose")]
-    pub block: Span,
+    pub block: Option<Span>,
 }
 
 #[derive(Diagnostic)]
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 1cc7fee718e..c26bbb926ea 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -1288,7 +1288,7 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, '_, 'tcx> {
             return false;
         }
         // Try to find predicates on *generic params* that would allow copying `ty`
-        let suggestion =
+        let mut suggestion =
             if let Some(symbol) = tcx.hir().maybe_get_struct_pattern_shorthand_field(expr) {
                 format!(": {symbol}.clone()")
             } else {
@@ -1296,6 +1296,8 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, '_, 'tcx> {
             };
         let mut sugg = Vec::with_capacity(2);
         let mut inner_expr = expr;
+        let mut is_raw_ptr = false;
+        let typeck_result = self.infcx.tcx.typeck(self.mir_def_id());
         // Remove uses of `&` and `*` when suggesting `.clone()`.
         while let hir::ExprKind::AddrOf(.., inner) | hir::ExprKind::Unary(hir::UnOp::Deref, inner) =
             &inner_expr.kind
@@ -1306,14 +1308,32 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, '_, 'tcx> {
                 return false;
             }
             inner_expr = inner;
+            if let Some(inner_type) = typeck_result.node_type_opt(inner.hir_id) {
+                if matches!(inner_type.kind(), ty::RawPtr(..)) {
+                    is_raw_ptr = true;
+                    break;
+                }
+            }
         }
-        if inner_expr.span.lo() != expr.span.lo() {
+        // Cloning the raw pointer doesn't make sense in some cases and would cause a type mismatch error. (see #126863)
+        if inner_expr.span.lo() != expr.span.lo() && !is_raw_ptr {
+            // Remove "(*" or "(&"
             sugg.push((expr.span.with_hi(inner_expr.span.lo()), String::new()));
         }
+        // Check whether `expr` is surrounded by parentheses or not.
         let span = if inner_expr.span.hi() != expr.span.hi() {
             // Account for `(*x)` to suggest `x.clone()`.
-            expr.span.with_lo(inner_expr.span.hi())
+            if is_raw_ptr {
+                expr.span.shrink_to_hi()
+            } else {
+                // Remove the close parenthesis ")"
+                expr.span.with_lo(inner_expr.span.hi())
+            }
         } else {
+            if is_raw_ptr {
+                sugg.push((expr.span.shrink_to_lo(), "(".to_string()));
+                suggestion = ").clone()".to_string();
+            }
             expr.span.shrink_to_hi()
         };
         sugg.push((span, suggestion));
diff --git a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
index 12fa4c4f5ee..407b83d4977 100644
--- a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
@@ -639,12 +639,27 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, '_, 'tcx> {
     fn add_borrow_suggestions(&self, err: &mut Diag<'_>, span: Span) {
         match self.infcx.tcx.sess.source_map().span_to_snippet(span) {
             Ok(snippet) if snippet.starts_with('*') => {
-                err.span_suggestion_verbose(
-                    span.with_hi(span.lo() + BytePos(1)),
-                    "consider removing the dereference here",
-                    String::new(),
-                    Applicability::MaybeIncorrect,
-                );
+                let sp = span.with_lo(span.lo() + BytePos(1));
+                let inner = self.find_expr(sp);
+                let mut is_raw_ptr = false;
+                if let Some(inner) = inner {
+                    let typck_result = self.infcx.tcx.typeck(self.mir_def_id());
+                    if let Some(inner_type) = typck_result.node_type_opt(inner.hir_id) {
+                        if matches!(inner_type.kind(), ty::RawPtr(..)) {
+                            is_raw_ptr = true;
+                        }
+                    }
+                }
+                // If the `inner` is a raw pointer, do not suggest removing the "*", see #126863
+                // FIXME: need to check whether the assigned object can be a raw pointer, see `tests/ui/borrowck/issue-20801.rs`.
+                if !is_raw_ptr {
+                    err.span_suggestion_verbose(
+                        span.with_hi(span.lo() + BytePos(1)),
+                        "consider removing the dereference here",
+                        String::new(),
+                        Applicability::MaybeIncorrect,
+                    );
+                }
             }
             _ => {
                 err.span_suggestion_verbose(
diff --git a/compiler/rustc_codegen_gcc/src/common.rs b/compiler/rustc_codegen_gcc/src/common.rs
index 548c23cc794..230fe4f5871 100644
--- a/compiler/rustc_codegen_gcc/src/common.rs
+++ b/compiler/rustc_codegen_gcc/src/common.rs
@@ -28,6 +28,19 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         global
         // TODO(antoyo): set linkage.
     }
+
+    pub fn const_bitcast(&self, value: RValue<'gcc>, typ: Type<'gcc>) -> RValue<'gcc> {
+        if value.get_type() == self.bool_type.make_pointer() {
+            if let Some(pointee) = typ.get_pointee() {
+                if pointee.dyncast_vector().is_some() {
+                    panic!()
+                }
+            }
+        }
+        // NOTE: since bitcast makes a value non-constant, don't bitcast if not necessary as some
+        // SIMD builtins require a constant value.
+        self.bitcast_if_needed(value, typ)
+    }
 }
 
 pub fn bytes_in_context<'gcc, 'tcx>(cx: &CodegenCx<'gcc, 'tcx>, bytes: &[u8]) -> RValue<'gcc> {
@@ -239,19 +252,6 @@ impl<'gcc, 'tcx> ConstMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         const_alloc_to_gcc(self, alloc)
     }
 
-    fn const_bitcast(&self, value: RValue<'gcc>, typ: Type<'gcc>) -> RValue<'gcc> {
-        if value.get_type() == self.bool_type.make_pointer() {
-            if let Some(pointee) = typ.get_pointee() {
-                if pointee.dyncast_vector().is_some() {
-                    panic!()
-                }
-            }
-        }
-        // NOTE: since bitcast makes a value non-constant, don't bitcast if not necessary as some
-        // SIMD builtins require a constant value.
-        self.bitcast_if_needed(value, typ)
-    }
-
     fn const_ptr_byte_offset(&self, base_addr: Self::Value, offset: abi::Size) -> Self::Value {
         self.context
             .new_array_access(None, base_addr, self.const_usize(offset.bytes()))
diff --git a/compiler/rustc_codegen_gcc/src/context.rs b/compiler/rustc_codegen_gcc/src/context.rs
index 4a1f5188a80..6231b09552c 100644
--- a/compiler/rustc_codegen_gcc/src/context.rs
+++ b/compiler/rustc_codegen_gcc/src/context.rs
@@ -27,7 +27,6 @@ use crate::callee::get_fn;
 use crate::common::SignType;
 
 pub struct CodegenCx<'gcc, 'tcx> {
-    pub check_overflow: bool,
     pub codegen_unit: &'tcx CodegenUnit<'tcx>,
     pub context: &'gcc Context<'gcc>,
 
@@ -134,8 +133,6 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         tcx: TyCtxt<'tcx>,
         supports_128bit_integers: bool,
     ) -> Self {
-        let check_overflow = tcx.sess.overflow_checks();
-
         let create_type = |ctype, rust_type| {
             let layout = tcx.layout_of(ParamEnv::reveal_all().and(rust_type)).unwrap();
             let align = layout.align.abi.bytes();
@@ -271,7 +268,6 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         }
 
         let mut cx = Self {
-            check_overflow,
             codegen_unit,
             context,
             current_func: RefCell::new(None),
@@ -511,10 +507,6 @@ impl<'gcc, 'tcx> MiscMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         &self.tcx.sess
     }
 
-    fn check_overflow(&self) -> bool {
-        self.check_overflow
-    }
-
     fn codegen_unit(&self) -> &'tcx CodegenUnit<'tcx> {
         self.codegen_unit
     }
diff --git a/compiler/rustc_codegen_gcc/src/type_.rs b/compiler/rustc_codegen_gcc/src/type_.rs
index 68471b028be..4caff2e6310 100644
--- a/compiler/rustc_codegen_gcc/src/type_.rs
+++ b/compiler/rustc_codegen_gcc/src/type_.rs
@@ -89,13 +89,34 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
             ty::FloatTy::F128 => self.type_f128(),
         }
     }
-}
 
-impl<'gcc, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
-    fn type_i1(&self) -> Type<'gcc> {
+    pub fn type_i1(&self) -> Type<'gcc> {
         self.bool_type
     }
 
+    pub fn type_struct(&self, fields: &[Type<'gcc>], packed: bool) -> Type<'gcc> {
+        let types = fields.to_vec();
+        if let Some(typ) = self.struct_types.borrow().get(fields) {
+            return *typ;
+        }
+        let fields: Vec<_> = fields
+            .iter()
+            .enumerate()
+            .map(|(index, field)| {
+                self.context.new_field(None, *field, format!("field{}_TODO", index))
+            })
+            .collect();
+        let typ = self.context.new_struct_type(None, "struct", &fields).as_type();
+        if packed {
+            #[cfg(feature = "master")]
+            typ.set_packed();
+        }
+        self.struct_types.borrow_mut().insert(types, typ);
+        typ
+    }
+}
+
+impl<'gcc, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
     fn type_i8(&self) -> Type<'gcc> {
         self.i8_type
     }
@@ -131,7 +152,7 @@ impl<'gcc, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
     fn type_f64(&self) -> Type<'gcc> {
         self.double_type
     }
-    
+
     fn type_f128(&self) -> Type<'gcc> {
         unimplemented!("f16_f128")
     }
@@ -140,27 +161,6 @@ impl<'gcc, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         self.context.new_function_pointer_type(None, return_type, params, false)
     }
 
-    fn type_struct(&self, fields: &[Type<'gcc>], packed: bool) -> Type<'gcc> {
-        let types = fields.to_vec();
-        if let Some(typ) = self.struct_types.borrow().get(fields) {
-            return *typ;
-        }
-        let fields: Vec<_> = fields
-            .iter()
-            .enumerate()
-            .map(|(index, field)| {
-                self.context.new_field(None, *field, format!("field{}_TODO", index))
-            })
-            .collect();
-        let typ = self.context.new_struct_type(None, "struct", &fields).as_type();
-        if packed {
-            #[cfg(feature = "master")]
-            typ.set_packed();
-        }
-        self.struct_types.borrow_mut().insert(types, typ);
-        typ
-    }
-
     fn type_kind(&self, typ: Type<'gcc>) -> TypeKind {
         if self.is_int_type_or_bool(typ) {
             TypeKind::Integer
diff --git a/compiler/rustc_codegen_llvm/src/common.rs b/compiler/rustc_codegen_llvm/src/common.rs
index 4ffc92eb633..d42c6ed827a 100644
--- a/compiler/rustc_codegen_llvm/src/common.rs
+++ b/compiler/rustc_codegen_llvm/src/common.rs
@@ -329,10 +329,6 @@ impl<'ll, 'tcx> ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         const_alloc_to_llvm(self, alloc, /*static*/ false)
     }
 
-    fn const_bitcast(&self, val: &'ll Value, ty: &'ll Type) -> &'ll Value {
-        self.const_bitcast(val, ty)
-    }
-
     fn const_ptr_byte_offset(&self, base_addr: Self::Value, offset: abi::Size) -> Self::Value {
         unsafe {
             llvm::LLVMConstInBoundsGEP2(
diff --git a/compiler/rustc_codegen_llvm/src/context.rs b/compiler/rustc_codegen_llvm/src/context.rs
index 7d92888feee..1a8e8efdae5 100644
--- a/compiler/rustc_codegen_llvm/src/context.rs
+++ b/compiler/rustc_codegen_llvm/src/context.rs
@@ -3,6 +3,7 @@ use crate::back::write::to_llvm_code_model;
 use crate::callee::get_fn;
 use crate::coverageinfo;
 use crate::debuginfo;
+use crate::debuginfo::metadata::apply_vcall_visibility_metadata;
 use crate::llvm;
 use crate::llvm_util;
 use crate::type_::Type;
@@ -43,7 +44,6 @@ use std::str;
 /// All other LLVM data structures in the `CodegenCx` are tied to that `llvm::Context`.
 pub struct CodegenCx<'ll, 'tcx> {
     pub tcx: TyCtxt<'tcx>,
-    pub check_overflow: bool,
     pub use_dll_storage_attrs: bool,
     pub tls_model: llvm::ThreadLocalMode,
 
@@ -441,8 +441,6 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
         // start) and then strongly recommending static linkage on Windows!
         let use_dll_storage_attrs = tcx.sess.target.is_like_windows;
 
-        let check_overflow = tcx.sess.overflow_checks();
-
         let tls_model = to_llvm_tls_model(tcx.sess.tls_model());
 
         let (llcx, llmod) = (&*llvm_module.llcx, llvm_module.llmod());
@@ -466,7 +464,6 @@ impl<'ll, 'tcx> CodegenCx<'ll, 'tcx> {
 
         CodegenCx {
             tcx,
-            check_overflow,
             use_dll_storage_attrs,
             tls_model,
             llmod,
@@ -522,6 +519,15 @@ impl<'ll, 'tcx> MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         &self.vtables
     }
 
+    fn apply_vcall_visibility_metadata(
+        &self,
+        ty: Ty<'tcx>,
+        poly_trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
+        vtable: &'ll Value,
+    ) {
+        apply_vcall_visibility_metadata(self, ty, poly_trait_ref, vtable);
+    }
+
     fn get_fn(&self, instance: Instance<'tcx>) -> &'ll Value {
         get_fn(self, instance)
     }
@@ -596,10 +602,6 @@ impl<'ll, 'tcx> MiscMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         self.tcx.sess
     }
 
-    fn check_overflow(&self) -> bool {
-        self.check_overflow
-    }
-
     fn codegen_unit(&self) -> &'tcx CodegenUnit<'tcx> {
         self.codegen_unit
     }
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
index 8de4e0effad..742bfd76590 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
@@ -1449,12 +1449,18 @@ fn build_vtable_type_di_node<'ll, 'tcx>(
     .di_node
 }
 
-fn vcall_visibility_metadata<'ll, 'tcx>(
+pub(crate) fn apply_vcall_visibility_metadata<'ll, 'tcx>(
     cx: &CodegenCx<'ll, 'tcx>,
     ty: Ty<'tcx>,
     trait_ref: Option<PolyExistentialTraitRef<'tcx>>,
     vtable: &'ll Value,
 ) {
+    // FIXME(flip1995): The virtual function elimination optimization only works with full LTO in
+    // LLVM at the moment.
+    if !cx.sess().opts.unstable_opts.virtual_function_elimination || cx.sess().lto() != Lto::Fat {
+        return;
+    }
+
     enum VCallVisibility {
         Public = 0,
         LinkageUnit = 1,
@@ -1531,12 +1537,6 @@ pub fn create_vtable_di_node<'ll, 'tcx>(
     poly_trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
     vtable: &'ll Value,
 ) {
-    // FIXME(flip1995): The virtual function elimination optimization only works with full LTO in
-    // LLVM at the moment.
-    if cx.sess().opts.unstable_opts.virtual_function_elimination && cx.sess().lto() == Lto::Fat {
-        vcall_visibility_metadata(cx, ty, poly_trait_ref, vtable);
-    }
-
     if cx.dbg_cx.is_none() {
         return;
     }
diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs
index 4b7a2643007..ed0989a0ba4 100644
--- a/compiler/rustc_codegen_llvm/src/lib.rs
+++ b/compiler/rustc_codegen_llvm/src/lib.rs
@@ -274,10 +274,11 @@ impl CodegenBackend for LlvmCodegenBackend {
             |tcx, ()| llvm_util::global_llvm_features(tcx.sess, true)
     }
 
-    fn print(&self, req: &PrintRequest, out: &mut dyn PrintBackendInfo, sess: &Session) {
+    fn print(&self, req: &PrintRequest, out: &mut String, sess: &Session) {
+        use std::fmt::Write;
         match req.kind {
             PrintKind::RelocationModels => {
-                writeln!(out, "Available relocation models:");
+                writeln!(out, "Available relocation models:").unwrap();
                 for name in &[
                     "static",
                     "pic",
@@ -288,25 +289,25 @@ impl CodegenBackend for LlvmCodegenBackend {
                     "ropi-rwpi",
                     "default",
                 ] {
-                    writeln!(out, "    {name}");
+                    writeln!(out, "    {name}").unwrap();
                 }
-                writeln!(out);
+                writeln!(out).unwrap();
             }
             PrintKind::CodeModels => {
-                writeln!(out, "Available code models:");
+                writeln!(out, "Available code models:").unwrap();
                 for name in &["tiny", "small", "kernel", "medium", "large"] {
-                    writeln!(out, "    {name}");
+                    writeln!(out, "    {name}").unwrap();
                 }
-                writeln!(out);
+                writeln!(out).unwrap();
             }
             PrintKind::TlsModels => {
-                writeln!(out, "Available TLS models:");
+                writeln!(out, "Available TLS models:").unwrap();
                 for name in
                     &["global-dynamic", "local-dynamic", "initial-exec", "local-exec", "emulated"]
                 {
-                    writeln!(out, "    {name}");
+                    writeln!(out, "    {name}").unwrap();
                 }
-                writeln!(out);
+                writeln!(out).unwrap();
             }
             PrintKind::StackProtectorStrategies => {
                 writeln!(
@@ -332,7 +333,8 @@ impl CodegenBackend for LlvmCodegenBackend {
     none
         Do not generate stack canaries.
 "#
-                );
+                )
+                .unwrap();
             }
             _other => llvm_util::print(req, out, sess),
         }
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index 7e0f264a4ae..0e89e66be49 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -6,7 +6,6 @@ use crate::errors::{
 use crate::llvm;
 use libc::c_int;
 use rustc_codegen_ssa::base::wants_wasm_eh;
-use rustc_codegen_ssa::traits::PrintBackendInfo;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_fs_util::path_to_c_string;
@@ -18,6 +17,7 @@ use rustc_target::spec::{MergeFunctions, PanicStrategy};
 use rustc_target::target_features::RUSTC_SPECIFIC_FEATURES;
 
 use std::ffi::{c_char, c_void, CStr, CString};
+use std::fmt::Write;
 use std::path::Path;
 use std::ptr;
 use std::slice;
@@ -372,7 +372,7 @@ fn llvm_target_features(tm: &llvm::TargetMachine) -> Vec<(&str, &str)> {
     ret
 }
 
-fn print_target_features(out: &mut dyn PrintBackendInfo, sess: &Session, tm: &llvm::TargetMachine) {
+fn print_target_features(out: &mut String, sess: &Session, tm: &llvm::TargetMachine) {
     let mut llvm_target_features = llvm_target_features(tm);
     let mut known_llvm_target_features = FxHashSet::<&'static str>::default();
     let mut rustc_target_features = sess
@@ -412,24 +412,26 @@ fn print_target_features(out: &mut dyn PrintBackendInfo, sess: &Session, tm: &ll
         .max()
         .unwrap_or(0);
 
-    writeln!(out, "Features supported by rustc for this target:");
+    writeln!(out, "Features supported by rustc for this target:").unwrap();
     for (feature, desc) in &rustc_target_features {
-        writeln!(out, "    {feature:max_feature_len$} - {desc}.");
+        writeln!(out, "    {feature:max_feature_len$} - {desc}.").unwrap();
     }
-    writeln!(out, "\nCode-generation features supported by LLVM for this target:");
+    writeln!(out, "\nCode-generation features supported by LLVM for this target:").unwrap();
     for (feature, desc) in &llvm_target_features {
-        writeln!(out, "    {feature:max_feature_len$} - {desc}.");
+        writeln!(out, "    {feature:max_feature_len$} - {desc}.").unwrap();
     }
     if llvm_target_features.is_empty() {
-        writeln!(out, "    Target features listing is not supported by this LLVM version.");
+        writeln!(out, "    Target features listing is not supported by this LLVM version.")
+            .unwrap();
     }
-    writeln!(out, "\nUse +feature to enable a feature, or -feature to disable it.");
-    writeln!(out, "For example, rustc -C target-cpu=mycpu -C target-feature=+feature1,-feature2\n");
-    writeln!(out, "Code-generation features cannot be used in cfg or #[target_feature],");
-    writeln!(out, "and may be renamed or removed in a future version of LLVM or rustc.\n");
+    writeln!(out, "\nUse +feature to enable a feature, or -feature to disable it.").unwrap();
+    writeln!(out, "For example, rustc -C target-cpu=mycpu -C target-feature=+feature1,-feature2\n")
+        .unwrap();
+    writeln!(out, "Code-generation features cannot be used in cfg or #[target_feature],").unwrap();
+    writeln!(out, "and may be renamed or removed in a future version of LLVM or rustc.\n").unwrap();
 }
 
-pub(crate) fn print(req: &PrintRequest, mut out: &mut dyn PrintBackendInfo, sess: &Session) {
+pub(crate) fn print(req: &PrintRequest, mut out: &mut String, sess: &Session) {
     require_inited();
     let tm = create_informational_target_machine(sess);
     match req.kind {
@@ -440,9 +442,9 @@ pub(crate) fn print(req: &PrintRequest, mut out: &mut dyn PrintBackendInfo, sess
             let cpu_cstring = CString::new(handle_native(sess.target.cpu.as_ref()))
                 .unwrap_or_else(|e| bug!("failed to convert to cstring: {}", e));
             unsafe extern "C" fn callback(out: *mut c_void, string: *const c_char, len: usize) {
-                let out = &mut *(out as *mut &mut dyn PrintBackendInfo);
+                let out = &mut *(out as *mut &mut String);
                 let bytes = slice::from_raw_parts(string as *const u8, len);
-                write!(out, "{}", String::from_utf8_lossy(bytes));
+                write!(out, "{}", String::from_utf8_lossy(bytes)).unwrap();
             }
             unsafe {
                 llvm::LLVMRustPrintTargetCPUs(
diff --git a/compiler/rustc_codegen_llvm/src/type_.rs b/compiler/rustc_codegen_llvm/src/type_.rs
index a00f09dc40d..f1141c57ced 100644
--- a/compiler/rustc_codegen_llvm/src/type_.rs
+++ b/compiler/rustc_codegen_llvm/src/type_.rs
@@ -127,13 +127,24 @@ impl<'ll> CodegenCx<'ll, '_> {
     pub(crate) fn type_variadic_func(&self, args: &[&'ll Type], ret: &'ll Type) -> &'ll Type {
         unsafe { llvm::LLVMFunctionType(ret, args.as_ptr(), args.len() as c_uint, True) }
     }
-}
 
-impl<'ll, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'ll, 'tcx> {
-    fn type_i1(&self) -> &'ll Type {
+    pub(crate) fn type_i1(&self) -> &'ll Type {
         unsafe { llvm::LLVMInt1TypeInContext(self.llcx) }
     }
 
+    pub(crate) fn type_struct(&self, els: &[&'ll Type], packed: bool) -> &'ll Type {
+        unsafe {
+            llvm::LLVMStructTypeInContext(
+                self.llcx,
+                els.as_ptr(),
+                els.len() as c_uint,
+                packed as Bool,
+            )
+        }
+    }
+}
+
+impl<'ll, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'ll, 'tcx> {
     fn type_i8(&self) -> &'ll Type {
         unsafe { llvm::LLVMInt8TypeInContext(self.llcx) }
     }
@@ -178,17 +189,6 @@ impl<'ll, 'tcx> BaseTypeMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         unsafe { llvm::LLVMFunctionType(ret, args.as_ptr(), args.len() as c_uint, False) }
     }
 
-    fn type_struct(&self, els: &[&'ll Type], packed: bool) -> &'ll Type {
-        unsafe {
-            llvm::LLVMStructTypeInContext(
-                self.llcx,
-                els.as_ptr(),
-                els.len() as c_uint,
-                packed as Bool,
-            )
-        }
-    }
-
     fn type_kind(&self, ty: &'ll Type) -> TypeKind {
         unsafe { llvm::LLVMRustGetTypeKind(ty).to_generic() }
     }
diff --git a/compiler/rustc_codegen_ssa/src/meth.rs b/compiler/rustc_codegen_ssa/src/meth.rs
index ddc6797388e..febc8ee2be2 100644
--- a/compiler/rustc_codegen_ssa/src/meth.rs
+++ b/compiler/rustc_codegen_ssa/src/meth.rs
@@ -133,6 +133,7 @@ pub fn get_vtable<'tcx, Cx: CodegenMethods<'tcx>>(
     let align = cx.data_layout().pointer_align.abi;
     let vtable = cx.static_addr_of(vtable_const, align, Some("vtable"));
 
+    cx.apply_vcall_visibility_metadata(ty, trait_ref, vtable);
     cx.create_vtable_debuginfo(ty, trait_ref, vtable);
     cx.vtables().borrow_mut().insert((ty, trait_ref), vtable);
     vtable
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index 57138d3b9db..b1c22faf1ae 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -658,7 +658,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         // with #[rustc_inherit_overflow_checks] and inlined from
         // another crate (mostly core::num generic/#[inline] fns),
         // while the current crate doesn't use overflow checks.
-        if !bx.cx().check_overflow() && msg.is_optional_overflow_check() {
+        if !bx.sess().overflow_checks() && msg.is_optional_overflow_check() {
             const_cond = Some(expected);
         }
 
@@ -751,7 +751,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         &mut self,
         helper: &TerminatorCodegenHelper<'tcx>,
         bx: &mut Bx,
-        intrinsic: Option<ty::IntrinsicDef>,
+        intrinsic: ty::IntrinsicDef,
         instance: Option<Instance<'tcx>>,
         source_info: mir::SourceInfo,
         target: Option<mir::BasicBlock>,
@@ -761,8 +761,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         // Emit a panic or a no-op for `assert_*` intrinsics.
         // These are intrinsics that compile to panics so that we can get a message
         // which mentions the offending type, even from a const context.
-        let panic_intrinsic = intrinsic.and_then(|i| ValidityRequirement::from_intrinsic(i.name));
-        if let Some(requirement) = panic_intrinsic {
+        if let Some(requirement) = ValidityRequirement::from_intrinsic(intrinsic.name) {
             let ty = instance.unwrap().args.type_at(0);
 
             let do_panic = !bx
@@ -869,12 +868,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         let sig = callee.layout.ty.fn_sig(bx.tcx());
         let abi = sig.abi();
 
-        // Handle intrinsics old codegen wants Expr's for, ourselves.
-        let intrinsic = match def {
-            Some(ty::InstanceKind::Intrinsic(def_id)) => Some(bx.tcx().intrinsic(def_id).unwrap()),
-            _ => None,
-        };
-
         let extra_args = &args[sig.inputs().skip_binder().len()..];
         let extra_args = bx.tcx().mk_type_list_from_iter(extra_args.iter().map(|op_arg| {
             let op_ty = op_arg.node.ty(self.mir, bx.tcx());
@@ -886,50 +879,25 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             None => bx.fn_abi_of_fn_ptr(sig, extra_args),
         };
 
-        if let Some(merging_succ) = self.codegen_panic_intrinsic(
-            &helper,
-            bx,
-            intrinsic,
-            instance,
-            source_info,
-            target,
-            unwind,
-            mergeable_succ,
-        ) {
-            return merging_succ;
-        }
-
         // The arguments we'll be passing. Plus one to account for outptr, if used.
         let arg_count = fn_abi.args.len() + fn_abi.ret.is_indirect() as usize;
 
-        if matches!(intrinsic, Some(ty::IntrinsicDef { name: sym::caller_location, .. })) {
-            return if let Some(target) = target {
-                let location =
-                    self.get_caller_location(bx, mir::SourceInfo { span: fn_span, ..source_info });
-
-                let mut llargs = Vec::with_capacity(arg_count);
-                let ret_dest = self.make_return_dest(
+        let instance = match def {
+            Some(ty::InstanceKind::Intrinsic(def_id)) => {
+                let intrinsic = bx.tcx().intrinsic(def_id).unwrap();
+                if let Some(merging_succ) = self.codegen_panic_intrinsic(
+                    &helper,
                     bx,
-                    destination,
-                    &fn_abi.ret,
-                    &mut llargs,
                     intrinsic,
-                    Some(target),
-                );
-                assert_eq!(llargs, []);
-                if let ReturnDest::IndirectOperand(tmp, _) = ret_dest {
-                    location.val.store(bx, tmp);
+                    instance,
+                    source_info,
+                    target,
+                    unwind,
+                    mergeable_succ,
+                ) {
+                    return merging_succ;
                 }
-                self.store_return(bx, ret_dest, &fn_abi.ret, location.immediate());
-                helper.funclet_br(self, bx, target, mergeable_succ)
-            } else {
-                MergingSucc::False
-            };
-        }
 
-        let instance = match intrinsic {
-            None => instance,
-            Some(intrinsic) => {
                 let mut llargs = Vec::with_capacity(1);
                 let ret_dest = self.make_return_dest(
                     bx,
@@ -971,6 +939,18 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     })
                     .collect();
 
+                if matches!(intrinsic, ty::IntrinsicDef { name: sym::caller_location, .. }) {
+                    let location = self
+                        .get_caller_location(bx, mir::SourceInfo { span: fn_span, ..source_info });
+
+                    assert_eq!(llargs, []);
+                    if let ReturnDest::IndirectOperand(tmp, _) = ret_dest {
+                        location.val.store(bx, tmp);
+                    }
+                    self.store_return(bx, ret_dest, &fn_abi.ret, location.immediate());
+                    return helper.funclet_br(self, bx, target.unwrap(), mergeable_succ);
+                }
+
                 let instance = *instance.as_ref().unwrap();
                 match Self::codegen_intrinsic_call(bx, instance, fn_abi, &args, dest, span) {
                     Ok(()) => {
@@ -997,6 +977,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     }
                 }
             }
+            _ => instance,
         };
 
         let mut llargs = Vec::with_capacity(arg_count);
diff --git a/compiler/rustc_codegen_ssa/src/traits/backend.rs b/compiler/rustc_codegen_ssa/src/traits/backend.rs
index e8b9490d401..3770bd11cf9 100644
--- a/compiler/rustc_codegen_ssa/src/traits/backend.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/backend.rs
@@ -22,8 +22,6 @@ use rustc_session::{
 use rustc_span::symbol::Symbol;
 use rustc_target::abi::call::FnAbi;
 
-use std::fmt;
-
 pub trait BackendTypes {
     type Value: CodegenObject;
     type Function: CodegenObject;
@@ -62,7 +60,7 @@ pub trait CodegenBackend {
     fn locale_resource(&self) -> &'static str;
 
     fn init(&self, _sess: &Session) {}
-    fn print(&self, _req: &PrintRequest, _out: &mut dyn PrintBackendInfo, _sess: &Session) {}
+    fn print(&self, _req: &PrintRequest, _out: &mut String, _sess: &Session) {}
     fn target_features(&self, _sess: &Session, _allow_unstable: bool) -> Vec<Symbol> {
         vec![]
     }
@@ -150,19 +148,3 @@ pub trait ExtraBackendMethods:
         std::thread::Builder::new().name(name).spawn(f)
     }
 }
-
-pub trait PrintBackendInfo {
-    fn infallible_write_fmt(&mut self, args: fmt::Arguments<'_>);
-}
-
-impl PrintBackendInfo for String {
-    fn infallible_write_fmt(&mut self, args: fmt::Arguments<'_>) {
-        fmt::Write::write_fmt(self, args).unwrap();
-    }
-}
-
-impl dyn PrintBackendInfo + '_ {
-    pub fn write_fmt(&mut self, args: fmt::Arguments<'_>) {
-        self.infallible_write_fmt(args);
-    }
-}
diff --git a/compiler/rustc_codegen_ssa/src/traits/consts.rs b/compiler/rustc_codegen_ssa/src/traits/consts.rs
index 8cb17a5b37a..3da732602c5 100644
--- a/compiler/rustc_codegen_ssa/src/traits/consts.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/consts.rs
@@ -37,6 +37,5 @@ pub trait ConstMethods<'tcx>: BackendTypes {
 
     fn scalar_to_backend(&self, cv: Scalar, layout: abi::Scalar, llty: Self::Type) -> Self::Value;
 
-    fn const_bitcast(&self, val: Self::Value, ty: Self::Type) -> Self::Value;
     fn const_ptr_byte_offset(&self, val: Self::Value, offset: abi::Size) -> Self::Value;
 }
diff --git a/compiler/rustc_codegen_ssa/src/traits/misc.rs b/compiler/rustc_codegen_ssa/src/traits/misc.rs
index 04e2b8796c4..0ace28ed3ba 100644
--- a/compiler/rustc_codegen_ssa/src/traits/misc.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/misc.rs
@@ -9,7 +9,13 @@ pub trait MiscMethods<'tcx>: BackendTypes {
     fn vtables(
         &self,
     ) -> &RefCell<FxHashMap<(Ty<'tcx>, Option<ty::PolyExistentialTraitRef<'tcx>>), Self::Value>>;
-    fn check_overflow(&self) -> bool;
+    fn apply_vcall_visibility_metadata(
+        &self,
+        _ty: Ty<'tcx>,
+        _poly_trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
+        _vtable: Self::Value,
+    ) {
+    }
     fn get_fn(&self, instance: Instance<'tcx>) -> Self::Function;
     fn get_fn_addr(&self, instance: Instance<'tcx>) -> Self::Value;
     fn eh_personality(&self) -> Self::Value;
diff --git a/compiler/rustc_codegen_ssa/src/traits/mod.rs b/compiler/rustc_codegen_ssa/src/traits/mod.rs
index 728c2bc8c49..8cb58bd4c70 100644
--- a/compiler/rustc_codegen_ssa/src/traits/mod.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/mod.rs
@@ -30,9 +30,7 @@ mod write;
 
 pub use self::abi::AbiBuilderMethods;
 pub use self::asm::{AsmBuilderMethods, AsmMethods, GlobalAsmOperandRef, InlineAsmOperandRef};
-pub use self::backend::{
-    Backend, BackendTypes, CodegenBackend, ExtraBackendMethods, PrintBackendInfo,
-};
+pub use self::backend::{Backend, BackendTypes, CodegenBackend, ExtraBackendMethods};
 pub use self::builder::{BuilderMethods, OverflowOp};
 pub use self::consts::ConstMethods;
 pub use self::coverageinfo::CoverageInfoBuilderMethods;
diff --git a/compiler/rustc_codegen_ssa/src/traits/type_.rs b/compiler/rustc_codegen_ssa/src/traits/type_.rs
index 403f6a73277..b1bad6cfa6f 100644
--- a/compiler/rustc_codegen_ssa/src/traits/type_.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/type_.rs
@@ -12,7 +12,6 @@ use rustc_target::abi::{AddressSpace, Float, Integer};
 // This depends on `Backend` and not `BackendTypes`, because consumers will probably want to use
 // `LayoutOf` or `HasTyCtxt`. This way, they don't have to add a constraint on it themselves.
 pub trait BaseTypeMethods<'tcx>: Backend<'tcx> {
-    fn type_i1(&self) -> Self::Type;
     fn type_i8(&self) -> Self::Type;
     fn type_i16(&self) -> Self::Type;
     fn type_i32(&self) -> Self::Type;
@@ -27,7 +26,6 @@ pub trait BaseTypeMethods<'tcx>: Backend<'tcx> {
 
     fn type_array(&self, ty: Self::Type, len: u64) -> Self::Type;
     fn type_func(&self, args: &[Self::Type], ret: Self::Type) -> Self::Type;
-    fn type_struct(&self, els: &[Self::Type], packed: bool) -> Self::Type;
     fn type_kind(&self, ty: Self::Type) -> TypeKind;
     fn type_ptr(&self) -> Self::Type;
     fn type_ptr_ext(&self, address_space: AddressSpace) -> Self::Type;
@@ -115,8 +113,8 @@ pub trait LayoutTypeMethods<'tcx>: Backend<'tcx> {
     /// The backend type used for a rust type when it's in an SSA register.
     ///
     /// For nearly all types this is the same as the [`Self::backend_type`], however
-    /// `bool` (and other `0`-or-`1` values) are kept as [`BaseTypeMethods::type_i1`]
-    /// in registers but as [`BaseTypeMethods::type_i8`] in memory.
+    /// `bool` (and other `0`-or-`1` values) are kept as `i1` in registers but as
+    /// [`BaseTypeMethods::type_i8`] in memory.
     ///
     /// Converting values between the two different backend types is done using
     /// [`from_immediate`](super::BuilderMethods::from_immediate) and
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index 3461ed7e326..41fbef48940 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -1459,8 +1459,25 @@ fn infer_return_ty_for_fn_sig<'tcx>(
         Some(ty) => {
             let fn_sig = tcx.typeck(def_id).liberated_fn_sigs()[hir_id];
             // Typeck doesn't expect erased regions to be returned from `type_of`.
+            // This is a heuristic approach. If the scope has region paramters,
+            // we should change fn_sig's lifetime from `ReErased` to `ReError`,
+            // otherwise to `ReStatic`.
+            let has_region_params = generics.params.iter().any(|param| match param.kind {
+                GenericParamKind::Lifetime { .. } => true,
+                _ => false,
+            });
             let fn_sig = tcx.fold_regions(fn_sig, |r, _| match *r {
-                ty::ReErased => tcx.lifetimes.re_static,
+                ty::ReErased => {
+                    if has_region_params {
+                        ty::Region::new_error_with_message(
+                            tcx,
+                            DUMMY_SP,
+                            "erased region is not allowed here in return type",
+                        )
+                    } else {
+                        tcx.lifetimes.re_static
+                    }
+                }
                 _ => r,
             });
 
diff --git a/compiler/rustc_passes/messages.ftl b/compiler/rustc_passes/messages.ftl
index 5a560325ab9..d7513fbad63 100644
--- a/compiler/rustc_passes/messages.ftl
+++ b/compiler/rustc_passes/messages.ftl
@@ -782,6 +782,7 @@ passes_used_compiler_linker =
 
 passes_used_static =
     attribute must be applied to a `static` variable
+    .label = but this is a {$target}
 
 passes_useless_assignment =
     useless assignment of {$is_field_assign ->
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 5f8e4a8b7a7..0eb9d1ce59f 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -274,7 +274,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         }
 
         self.check_repr(attrs, span, target, item, hir_id);
-        self.check_used(attrs, target);
+        self.check_used(attrs, target, span);
     }
 
     fn inline_attr_str_error_with_macro_def(&self, hir_id: HirId, attr: &Attribute, sym: &str) {
@@ -1930,12 +1930,16 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         }
     }
 
-    fn check_used(&self, attrs: &[Attribute], target: Target) {
+    fn check_used(&self, attrs: &[Attribute], target: Target, target_span: Span) {
         let mut used_linker_span = None;
         let mut used_compiler_span = None;
         for attr in attrs.iter().filter(|attr| attr.has_name(sym::used)) {
             if target != Target::Static {
-                self.dcx().emit_err(errors::UsedStatic { span: attr.span });
+                self.dcx().emit_err(errors::UsedStatic {
+                    attr_span: attr.span,
+                    span: target_span,
+                    target: target.name(),
+                });
             }
             let inner = attr.meta_item_list();
             match inner.as_deref() {
diff --git a/compiler/rustc_passes/src/errors.rs b/compiler/rustc_passes/src/errors.rs
index 7734dba3670..a026ff3b13b 100644
--- a/compiler/rustc_passes/src/errors.rs
+++ b/compiler/rustc_passes/src/errors.rs
@@ -551,7 +551,10 @@ pub struct ReprConflictingLint;
 #[diag(passes_used_static)]
 pub struct UsedStatic {
     #[primary_span]
+    pub attr_span: Span,
+    #[label]
     pub span: Span,
+    pub target: &'static str,
 }
 
 #[derive(Diagnostic)]
diff --git a/library/core/src/num/uint_macros.rs b/library/core/src/num/uint_macros.rs
index cd74cece0d1..ad72c29758b 100644
--- a/library/core/src/num/uint_macros.rs
+++ b/library/core/src/num/uint_macros.rs
@@ -2726,7 +2726,7 @@ macro_rules! uint_impl {
         pub const fn div_ceil(self, rhs: Self) -> Self {
             let d = self / rhs;
             let r = self % rhs;
-            if r > 0 && rhs > 0 {
+            if r > 0 {
                 d + 1
             } else {
                 d
diff --git a/src/bootstrap/src/core/build_steps/perf.rs b/src/bootstrap/src/core/build_steps/perf.rs
index 9d70ca6bd71..f41b5fe10f1 100644
--- a/src/bootstrap/src/core/build_steps/perf.rs
+++ b/src/bootstrap/src/core/build_steps/perf.rs
@@ -1,7 +1,5 @@
-use std::process::Command;
-
 use crate::core::build_steps::compile::{Std, Sysroot};
-use crate::core::build_steps::tool::RustcPerf;
+use crate::core::build_steps::tool::{RustcPerf, Tool};
 use crate::core::builder::Builder;
 use crate::core::config::DebuginfoLevel;
 
@@ -22,24 +20,16 @@ Consider setting `rust.debuginfo-level = 1` in `config.toml`."#);
     let sysroot = builder.ensure(Sysroot::new(compiler));
     let rustc = sysroot.join("bin/rustc");
 
-    let results_dir = builder.build.tempdir().join("rustc-perf");
-
-    let mut cmd = Command::new(collector);
-    let cmd = cmd
-        .arg("profile_local")
-        .arg("eprintln")
-        .arg("--out-dir")
-        .arg(&results_dir)
-        .arg("--include")
-        .arg("helloworld")
-        .arg(&rustc);
-
-    builder.info(&format!("Running `rustc-perf` using `{}`", rustc.display()));
+    let rustc_perf_dir = builder.build.tempdir().join("rustc-perf");
+    let profile_results_dir = rustc_perf_dir.join("results");
 
-    // We need to set the working directory to `src/tools/perf`, so that it can find the directory
-    // with compile-time benchmarks.
-    let cmd = cmd.current_dir(builder.src.join("src/tools/rustc-perf"));
-    builder.build.run(cmd);
+    // We need to take args passed after `--` and pass them to `rustc-perf-wrapper`
+    let args = std::env::args().skip_while(|a| a != "--").skip(1);
 
-    builder.info(&format!("You can find the results at `{}`", results_dir.display()));
+    let mut cmd = builder.tool_cmd(Tool::RustcPerfWrapper);
+    cmd.env("RUSTC_REAL", rustc)
+        .env("PERF_COLLECTOR", collector)
+        .env("PERF_RESULT_DIR", profile_results_dir)
+        .args(args);
+    builder.run(&mut cmd);
 }
diff --git a/src/bootstrap/src/core/build_steps/tool.rs b/src/bootstrap/src/core/build_steps/tool.rs
index f6258121c50..b3464043912 100644
--- a/src/bootstrap/src/core/build_steps/tool.rs
+++ b/src/bootstrap/src/core/build_steps/tool.rs
@@ -337,6 +337,7 @@ bootstrap_tool!(
     GenerateWindowsSys, "src/tools/generate-windows-sys", "generate-windows-sys";
     RustdocGUITest, "src/tools/rustdoc-gui-test", "rustdoc-gui-test", is_unstable_tool = true, allow_features = "test";
     CoverageDump, "src/tools/coverage-dump", "coverage-dump";
+    RustcPerfWrapper, "src/tools/rustc-perf-wrapper", "rustc-perf-wrapper";
 );
 
 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
diff --git a/src/bootstrap/src/core/config/flags.rs b/src/bootstrap/src/core/config/flags.rs
index eb5152a3831..aeb608a9ea2 100644
--- a/src/bootstrap/src/core/config/flags.rs
+++ b/src/bootstrap/src/core/config/flags.rs
@@ -470,7 +470,9 @@ Arguments:
         versioned_dirs: bool,
     },
     /// Perform profiling and benchmarking of the compiler using the
-    /// `rustc-perf` benchmark suite.
+    /// `rustc-perf-wrapper` tool.
+    ///
+    /// You need to pass arguments after `--`, e.g.`x perf -- cachegrind`.
     Perf {},
 }
 
diff --git a/src/etc/completions/x.py.fish b/src/etc/completions/x.py.fish
index 2072f76a481..805fc8aa8cc 100644
--- a/src/etc/completions/x.py.fish
+++ b/src/etc/completions/x.py.fish
@@ -48,7 +48,7 @@ complete -c x.py -n "__fish_use_subcommand" -f -a "run" -d 'Run tools contained
 complete -c x.py -n "__fish_use_subcommand" -f -a "setup" -d 'Set up the environment for development'
 complete -c x.py -n "__fish_use_subcommand" -f -a "suggest" -d 'Suggest a subset of tests to run, based on modified files'
 complete -c x.py -n "__fish_use_subcommand" -f -a "vendor" -d 'Vendor dependencies'
-complete -c x.py -n "__fish_use_subcommand" -f -a "perf" -d 'Perform profiling and benchmarking of the compiler using the `rustc-perf` benchmark suite'
+complete -c x.py -n "__fish_use_subcommand" -f -a "perf" -d 'Perform profiling and benchmarking of the compiler using the `rustc-perf-wrapper` tool'
 complete -c x.py -n "__fish_seen_subcommand_from build" -l config -d 'TOML configuration file for build' -r -F
 complete -c x.py -n "__fish_seen_subcommand_from build" -l build-dir -d 'Build directory, overrides `build.build-dir` in `config.toml`' -r -f -a "(__fish_complete_directories)"
 complete -c x.py -n "__fish_seen_subcommand_from build" -l build -d 'build target of the stage0 compiler' -r -f
diff --git a/src/etc/completions/x.py.ps1 b/src/etc/completions/x.py.ps1
index 919382d441f..ce590d2fa48 100644
--- a/src/etc/completions/x.py.ps1
+++ b/src/etc/completions/x.py.ps1
@@ -75,7 +75,7 @@ Register-ArgumentCompleter -Native -CommandName 'x.py' -ScriptBlock {
             [CompletionResult]::new('setup', 'setup', [CompletionResultType]::ParameterValue, 'Set up the environment for development')
             [CompletionResult]::new('suggest', 'suggest', [CompletionResultType]::ParameterValue, 'Suggest a subset of tests to run, based on modified files')
             [CompletionResult]::new('vendor', 'vendor', [CompletionResultType]::ParameterValue, 'Vendor dependencies')
-            [CompletionResult]::new('perf', 'perf', [CompletionResultType]::ParameterValue, 'Perform profiling and benchmarking of the compiler using the `rustc-perf` benchmark suite')
+            [CompletionResult]::new('perf', 'perf', [CompletionResultType]::ParameterValue, 'Perform profiling and benchmarking of the compiler using the `rustc-perf-wrapper` tool')
             break
         }
         'x.py;build' {
diff --git a/src/etc/completions/x.py.zsh b/src/etc/completions/x.py.zsh
index bbebf8b892d..fc8be4f7881 100644
--- a/src/etc/completions/x.py.zsh
+++ b/src/etc/completions/x.py.zsh
@@ -856,7 +856,7 @@ _x.py_commands() {
 'setup:Set up the environment for development' \
 'suggest:Suggest a subset of tests to run, based on modified files' \
 'vendor:Vendor dependencies' \
-'perf:Perform profiling and benchmarking of the compiler using the \`rustc-perf\` benchmark suite' \
+'perf:Perform profiling and benchmarking of the compiler using the \`rustc-perf-wrapper\` tool' \
     )
     _describe -t commands 'x.py commands' commands "$@"
 }
diff --git a/src/tools/rustc-perf-wrapper/Cargo.toml b/src/tools/rustc-perf-wrapper/Cargo.toml
new file mode 100644
index 00000000000..416bfef41d7
--- /dev/null
+++ b/src/tools/rustc-perf-wrapper/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "rustc-perf-wrapper"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+clap = { version = "4.5.7", features = ["derive", "env"] }
diff --git a/src/tools/rustc-perf-wrapper/README.md b/src/tools/rustc-perf-wrapper/README.md
new file mode 100644
index 00000000000..d7655459a2f
--- /dev/null
+++ b/src/tools/rustc-perf-wrapper/README.md
@@ -0,0 +1,3 @@
+# rustc-perf wrapper
+Utility tool for invoking [`rustc-perf`](https://github.com/rust-lang/rustc-perf) for benchmarking/profiling
+a stage1/2 compiler built by bootstrap using `x perf -- <command>`.
diff --git a/src/tools/rustc-perf-wrapper/src/config.rs b/src/tools/rustc-perf-wrapper/src/config.rs
new file mode 100644
index 00000000000..a88abfe4723
--- /dev/null
+++ b/src/tools/rustc-perf-wrapper/src/config.rs
@@ -0,0 +1,45 @@
+use std::fmt::{Display, Formatter};
+
+#[derive(Clone, Copy, Debug, clap::ValueEnum)]
+#[value(rename_all = "PascalCase")]
+pub enum Profile {
+    Check,
+    Debug,
+    Doc,
+    Opt,
+    Clippy,
+}
+
+impl Display for Profile {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        let name = match self {
+            Profile::Check => "Check",
+            Profile::Debug => "Debug",
+            Profile::Doc => "Doc",
+            Profile::Opt => "Opt",
+            Profile::Clippy => "Clippy",
+        };
+        f.write_str(name)
+    }
+}
+
+#[derive(Clone, Copy, Debug, clap::ValueEnum)]
+#[value(rename_all = "PascalCase")]
+pub enum Scenario {
+    Full,
+    IncrFull,
+    IncrUnchanged,
+    IncrPatched,
+}
+
+impl Display for Scenario {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        let name = match self {
+            Scenario::Full => "Full",
+            Scenario::IncrFull => "IncrFull",
+            Scenario::IncrUnchanged => "IncrUnchanged",
+            Scenario::IncrPatched => "IncrPatched",
+        };
+        f.write_str(name)
+    }
+}
diff --git a/src/tools/rustc-perf-wrapper/src/main.rs b/src/tools/rustc-perf-wrapper/src/main.rs
new file mode 100644
index 00000000000..1c0d1745f3d
--- /dev/null
+++ b/src/tools/rustc-perf-wrapper/src/main.rs
@@ -0,0 +1,130 @@
+use crate::config::{Profile, Scenario};
+use clap::Parser;
+use std::path::PathBuf;
+use std::process::Command;
+
+mod config;
+
+/// Performs profiling or benchmarking with [`rustc-perf`](https://github.com/rust-lang/rustc-perf)
+/// using a locally built compiler.
+#[derive(Debug, clap::Parser)]
+// Hide arguments from BuildContext in the default usage string.
+// Clap does not seem to have a way of disabling the usage of these arguments.
+#[clap(override_usage = "rustc-perf-wrapper [OPTIONS] <COMMAND>")]
+pub struct Args {
+    #[clap(subcommand)]
+    cmd: PerfCommand,
+
+    #[clap(flatten)]
+    opts: SharedOpts,
+
+    #[clap(flatten)]
+    ctx: BuildContext,
+}
+
+#[derive(Debug, clap::Parser)]
+enum PerfCommand {
+    /// Run `profile_local eprintln`.
+    /// This executes the compiler on the given benchmarks and stores its stderr output.
+    Eprintln,
+    /// Run `profile_local samply`
+    /// This executes the compiler on the given benchmarks and profiles it with `samply`.
+    /// You need to install `samply`, e.g. using `cargo install samply`.
+    Samply,
+    /// Run `profile_local cachegrind`.
+    /// This executes the compiler on the given benchmarks under `Cachegrind`.
+    Cachegrind,
+}
+
+impl PerfCommand {
+    fn is_profiling(&self) -> bool {
+        match self {
+            PerfCommand::Eprintln | PerfCommand::Samply | PerfCommand::Cachegrind => true,
+        }
+    }
+}
+
+#[derive(Debug, clap::Parser)]
+struct SharedOpts {
+    /// Select the benchmarks that you want to run (separated by commas).
+    /// If unspecified, all benchmarks will be executed.
+    #[clap(long, global = true, value_delimiter = ',')]
+    include: Vec<String>,
+    /// Select the scenarios that should be benchmarked.
+    #[clap(
+        long,
+        global = true,
+        value_delimiter = ',',
+        default_value = "Full,IncrFull,IncrUnchanged,IncrPatched"
+    )]
+    scenarios: Vec<Scenario>,
+    /// Select the profiles that should be benchmarked.
+    #[clap(long, global = true, value_delimiter = ',', default_value = "Check,Debug,Opt")]
+    profiles: Vec<Profile>,
+}
+
+/// These arguments are mostly designed to be passed from bootstrap, not by users
+/// directly.
+#[derive(Debug, clap::Parser)]
+struct BuildContext {
+    /// Compiler binary that will be benchmarked/profiled.
+    #[clap(long, hide = true, env = "RUSTC_REAL")]
+    compiler: PathBuf,
+    /// rustc-perf collector binary that will be used for running benchmarks/profilers.
+    #[clap(long, hide = true, env = "PERF_COLLECTOR")]
+    collector: PathBuf,
+    /// Directory where to store results.
+    #[clap(long, hide = true, env = "PERF_RESULT_DIR")]
+    results_dir: PathBuf,
+}
+
+fn main() {
+    let args = Args::parse();
+    run(args);
+}
+
+fn run(args: Args) {
+    let mut cmd = Command::new(args.ctx.collector);
+    match &args.cmd {
+        PerfCommand::Eprintln => {
+            cmd.arg("profile_local").arg("eprintln");
+        }
+        PerfCommand::Samply => {
+            cmd.arg("profile_local").arg("samply");
+        }
+        PerfCommand::Cachegrind => {
+            cmd.arg("profile_local").arg("cachegrind");
+        }
+    }
+    if args.cmd.is_profiling() {
+        cmd.arg("--out-dir").arg(&args.ctx.results_dir);
+    }
+
+    if !args.opts.include.is_empty() {
+        cmd.arg("--include").arg(args.opts.include.join(","));
+    }
+    if !args.opts.profiles.is_empty() {
+        cmd.arg("--profiles")
+            .arg(args.opts.profiles.iter().map(|p| p.to_string()).collect::<Vec<_>>().join(","));
+    }
+    if !args.opts.scenarios.is_empty() {
+        cmd.arg("--scenarios")
+            .arg(args.opts.scenarios.iter().map(|p| p.to_string()).collect::<Vec<_>>().join(","));
+    }
+    cmd.arg(&args.ctx.compiler);
+
+    println!("Running `rustc-perf` using `{}`", args.ctx.compiler.display());
+
+    const MANIFEST_DIR: &str = env!("CARGO_MANIFEST_DIR");
+
+    let rustc_perf_dir = PathBuf::from(MANIFEST_DIR).join("../rustc-perf");
+
+    // We need to set the working directory to `src/tools/perf`, so that it can find the directory
+    // with compile-time benchmarks.
+    let cmd = cmd.current_dir(rustc_perf_dir);
+    cmd.status().expect("error while running rustc-perf collector");
+
+    if args.cmd.is_profiling() {
+        println!("You can find the results at `{}`", args.ctx.results_dir.display());
+    }
+}
diff --git a/src/tools/tidy/src/ext_tool_checks.rs b/src/tools/tidy/src/ext_tool_checks.rs
index 1df4921ef86..8ce44115ef3 100644
--- a/src/tools/tidy/src/ext_tool_checks.rs
+++ b/src/tools/tidy/src/ext_tool_checks.rs
@@ -364,11 +364,10 @@ fn create_venv_at_path(path: &Path) -> Result<(), Error> {
 
     let stderr = String::from_utf8_lossy(&out.stderr);
     let err = if stderr.contains("No module named virtualenv") {
-        Error::Generic(
+        Error::Generic(format!(
             "virtualenv not found: you may need to install it \
-                               (`python3 -m pip install venv`)"
-                .to_owned(),
-        )
+                               (`{sys_py} -m pip install virtualenv`)"
+        ))
     } else {
         Error::Generic(format!(
             "failed to create venv at '{}' using {sys_py}: {stderr}",
diff --git a/tests/run-make/rust-lld-by-default-beta-stable/main.rs b/tests/run-make/rust-lld-by-default-beta-stable/main.rs
new file mode 100644
index 00000000000..f328e4d9d04
--- /dev/null
+++ b/tests/run-make/rust-lld-by-default-beta-stable/main.rs
@@ -0,0 +1 @@
+fn main() {}
diff --git a/tests/run-make/rust-lld-by-default-beta-stable/rmake.rs b/tests/run-make/rust-lld-by-default-beta-stable/rmake.rs
new file mode 100644
index 00000000000..fc3dffdbaf4
--- /dev/null
+++ b/tests/run-make/rust-lld-by-default-beta-stable/rmake.rs
@@ -0,0 +1,29 @@
+// Ensure that rust-lld is *not* used as the default linker on `x86_64-unknown-linux-gnu` on stable
+// or beta.
+
+//@ ignore-nightly
+//@ only-x86_64-unknown-linux-gnu
+
+use run_make_support::regex::Regex;
+use run_make_support::rustc;
+use std::process::Output;
+
+fn main() {
+    // A regular compilation should not use rust-lld by default. We'll check that by asking the
+    // linker to display its version number with a link-arg.
+    let output = rustc()
+        .env("RUSTC_LOG", "rustc_codegen_ssa::back::link=info")
+        .link_arg("-Wl,-v")
+        .input("main.rs")
+        .run();
+    assert!(
+        !find_lld_version_in_logs(output.stderr_utf8()),
+        "the LLD version string should not be present in the output logs:\n{}",
+        output.stderr_utf8()
+    );
+}
+
+fn find_lld_version_in_logs(stderr: String) -> bool {
+    let lld_version_re = Regex::new(r"^LLD [0-9]+\.[0-9]+\.[0-9]+").unwrap();
+    stderr.lines().any(|line| lld_version_re.is_match(line.trim()))
+}
diff --git a/tests/run-make/rust-lld-by-default/main.rs b/tests/run-make/rust-lld-by-default-nightly/main.rs
index e9f655fc09e..e9f655fc09e 100644
--- a/tests/run-make/rust-lld-by-default/main.rs
+++ b/tests/run-make/rust-lld-by-default-nightly/main.rs
diff --git a/tests/run-make/rust-lld-by-default/rmake.rs b/tests/run-make/rust-lld-by-default-nightly/rmake.rs
index 94857a57dfb..f3ce9ada157 100644
--- a/tests/run-make/rust-lld-by-default/rmake.rs
+++ b/tests/run-make/rust-lld-by-default-nightly/rmake.rs
@@ -1,5 +1,5 @@
-// Ensure that rust-lld is used as the default linker on `x86_64-unknown-linux-gnu`, and that it can
-// also be turned off with a CLI flag.
+// Ensure that rust-lld is used as the default linker on `x86_64-unknown-linux-gnu` on the nightly
+// channel, and that it can also be turned off with a CLI flag.
 
 //@ needs-rust-lld
 //@ ignore-beta
diff --git a/tests/ui/attributes/used-issue-126789.rs b/tests/ui/attributes/used-issue-126789.rs
new file mode 100644
index 00000000000..90a1aa8d5cc
--- /dev/null
+++ b/tests/ui/attributes/used-issue-126789.rs
@@ -0,0 +1,6 @@
+extern "C" {
+    #[used] //~ ERROR attribute must be applied to a `static` variable
+    static FOO: i32;
+}
+
+fn main() {}
diff --git a/tests/ui/attributes/used-issue-126789.stderr b/tests/ui/attributes/used-issue-126789.stderr
new file mode 100644
index 00000000000..6014f7af95c
--- /dev/null
+++ b/tests/ui/attributes/used-issue-126789.stderr
@@ -0,0 +1,10 @@
+error: attribute must be applied to a `static` variable
+  --> $DIR/used-issue-126789.rs:2:5
+   |
+LL |     #[used]
+   |     ^^^^^^^
+LL |     static FOO: i32;
+   |     ---------------- but this is a foreign static item
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui/borrowck/borrowck-move-from-unsafe-ptr.stderr b/tests/ui/borrowck/borrowck-move-from-unsafe-ptr.stderr
index ebc3b6ebcac..79f18624c61 100644
--- a/tests/ui/borrowck/borrowck-move-from-unsafe-ptr.stderr
+++ b/tests/ui/borrowck/borrowck-move-from-unsafe-ptr.stderr
@@ -4,16 +4,10 @@ error[E0507]: cannot move out of `*x` which is behind a raw pointer
 LL |     let y = *x;
    |             ^^ move occurs because `*x` has type `Box<isize>`, which does not implement the `Copy` trait
    |
-help: consider removing the dereference here
-   |
-LL -     let y = *x;
-LL +     let y = x;
-   |
 help: consider cloning the value if the performance cost is acceptable
    |
-LL -     let y = *x;
-LL +     let y = x.clone();
-   |
+LL |     let y = (*x).clone();
+   |             +  +++++++++
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/borrowck/issue-20801.stderr b/tests/ui/borrowck/issue-20801.stderr
index 20a4bd4e423..c1d06ac3e21 100644
--- a/tests/ui/borrowck/issue-20801.stderr
+++ b/tests/ui/borrowck/issue-20801.stderr
@@ -67,11 +67,6 @@ LL | struct T(u8);
 ...
 LL |     let c = unsafe { *mut_ptr() };
    |                      ---------- you could clone this value
-help: consider removing the dereference here
-   |
-LL -     let c = unsafe { *mut_ptr() };
-LL +     let c = unsafe { mut_ptr() };
-   |
 
 error[E0507]: cannot move out of a raw pointer
   --> $DIR/issue-20801.rs:36:22
@@ -87,11 +82,6 @@ LL | struct T(u8);
 ...
 LL |     let d = unsafe { *const_ptr() };
    |                      ------------ you could clone this value
-help: consider removing the dereference here
-   |
-LL -     let d = unsafe { *const_ptr() };
-LL +     let d = unsafe { const_ptr() };
-   |
 
 error: aborting due to 4 previous errors; 1 warning emitted
 
diff --git a/tests/ui/borrowck/move-from-union-field-issue-66500.stderr b/tests/ui/borrowck/move-from-union-field-issue-66500.stderr
index c951ce8e3cd..7f4593eefca 100644
--- a/tests/ui/borrowck/move-from-union-field-issue-66500.stderr
+++ b/tests/ui/borrowck/move-from-union-field-issue-66500.stderr
@@ -30,9 +30,8 @@ LL |     *u.c
    |
 help: consider cloning the value if the performance cost is acceptable
    |
-LL -     *u.c
-LL +     u.c.clone()
-   |
+LL |     (*u.c).clone()
+   |     +    +++++++++
 
 error[E0507]: cannot move out of `*u.d` which is behind a raw pointer
   --> $DIR/move-from-union-field-issue-66500.rs:24:5
@@ -42,9 +41,8 @@ LL |     *u.d
    |
 help: consider cloning the value if the performance cost is acceptable
    |
-LL -     *u.d
-LL +     u.d.clone()
-   |
+LL |     (*u.d).clone()
+   |     +    +++++++++
 
 error: aborting due to 4 previous errors
 
diff --git a/tests/ui/feature-gates/feature-gate-unsafe-extern-blocks.stderr b/tests/ui/feature-gates/feature-gate-unsafe-extern-blocks.stderr
index 84f00827c60..56534946308 100644
--- a/tests/ui/feature-gates/feature-gate-unsafe-extern-blocks.stderr
+++ b/tests/ui/feature-gates/feature-gate-unsafe-extern-blocks.stderr
@@ -3,6 +3,10 @@ error: extern block cannot be declared unsafe
    |
 LL | unsafe extern "C" {
    | ^^^^^^
+   |
+   = note: see issue #123743 <https://github.com/rust-lang/rust/issues/123743> for more information
+   = help: add `#![feature(unsafe_extern_blocks)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0658]: `unsafe extern {}` blocks and `safe` keyword are experimental
   --> $DIR/feature-gate-unsafe-extern-blocks.rs:9:5
diff --git a/tests/ui/parser/unsafe-foreign-mod-2.stderr b/tests/ui/parser/unsafe-foreign-mod-2.stderr
index 77a383d5efa..8bd592b5d43 100644
--- a/tests/ui/parser/unsafe-foreign-mod-2.stderr
+++ b/tests/ui/parser/unsafe-foreign-mod-2.stderr
@@ -9,17 +9,16 @@ error: extern block cannot be declared unsafe
    |
 LL | extern "C" unsafe {
    |            ^^^^^^
+   |
+   = note: see issue #123743 <https://github.com/rust-lang/rust/issues/123743> for more information
+   = help: add `#![feature(unsafe_extern_blocks)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error: items in unadorned `extern` blocks cannot have safety qualifiers
   --> $DIR/unsafe-foreign-mod-2.rs:4:5
    |
 LL |     unsafe fn foo();
    |     ^^^^^^^^^^^^^^^^
-   |
-help: add unsafe to this `extern` block
-   |
-LL | unsafe extern "C" unsafe {
-   | ++++++
 
 error: aborting due to 3 previous errors
 
diff --git a/tests/ui/parser/unsafe-foreign-mod.stderr b/tests/ui/parser/unsafe-foreign-mod.stderr
index 77f6e93be10..60b918a89b3 100644
--- a/tests/ui/parser/unsafe-foreign-mod.stderr
+++ b/tests/ui/parser/unsafe-foreign-mod.stderr
@@ -3,6 +3,10 @@ error: extern block cannot be declared unsafe
    |
 LL | unsafe extern "C" {
    | ^^^^^^
+   |
+   = note: see issue #123743 <https://github.com/rust-lang/rust/issues/123743> for more information
+   = help: add `#![feature(unsafe_extern_blocks)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/return/infer-return-ty-for-fn-sig-issue-125488.fixed b/tests/ui/return/infer-return-ty-for-fn-sig-issue-125488.fixed
new file mode 100644
index 00000000000..442ade6abf1
--- /dev/null
+++ b/tests/ui/return/infer-return-ty-for-fn-sig-issue-125488.fixed
@@ -0,0 +1,33 @@
+//@ run-rustfix
+
+#[allow(dead_code)]
+
+fn main() {
+    struct S<'a>(&'a ());
+
+    fn f1(s: S<'_>) -> S<'_> {
+        //~^ ERROR the placeholder `_` is not allowed
+        s
+    }
+
+    fn f2(s: S<'_>) -> S<'_> {
+        //~^ ERROR the placeholder `_` is not allowed
+        let x = true;
+        if x {
+            s
+        } else {
+            s
+        }
+    }
+
+    fn f3(s: S<'_>) -> S<'_> {
+        //~^ ERROR the placeholder `_` is not allowed
+        return s;
+    }
+
+    fn f4(s: S<'_>) -> S<'_> {
+        //~^ ERROR the placeholder `_` is not allowed
+        let _x = 1;
+        return s;
+    }
+}
diff --git a/tests/ui/return/infer-return-ty-for-fn-sig-issue-125488.rs b/tests/ui/return/infer-return-ty-for-fn-sig-issue-125488.rs
new file mode 100644
index 00000000000..04ea3a28add
--- /dev/null
+++ b/tests/ui/return/infer-return-ty-for-fn-sig-issue-125488.rs
@@ -0,0 +1,33 @@
+//@ run-rustfix
+
+#[allow(dead_code)]
+
+fn main() {
+    struct S<'a>(&'a ());
+
+    fn f1(s: S<'_>) -> _ {
+        //~^ ERROR the placeholder `_` is not allowed
+        s
+    }
+
+    fn f2(s: S<'_>) -> _ {
+        //~^ ERROR the placeholder `_` is not allowed
+        let x = true;
+        if x {
+            s
+        } else {
+            s
+        }
+    }
+
+    fn f3(s: S<'_>) -> _ {
+        //~^ ERROR the placeholder `_` is not allowed
+        return s;
+    }
+
+    fn f4(s: S<'_>) -> _ {
+        //~^ ERROR the placeholder `_` is not allowed
+        let _x = 1;
+        return s;
+    }
+}
diff --git a/tests/ui/return/infer-return-ty-for-fn-sig-issue-125488.stderr b/tests/ui/return/infer-return-ty-for-fn-sig-issue-125488.stderr
new file mode 100644
index 00000000000..8b7c5e1681a
--- /dev/null
+++ b/tests/ui/return/infer-return-ty-for-fn-sig-issue-125488.stderr
@@ -0,0 +1,39 @@
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
+  --> $DIR/infer-return-ty-for-fn-sig-issue-125488.rs:8:24
+   |
+LL |     fn f1(s: S<'_>) -> _ {
+   |                        ^
+   |                        |
+   |                        not allowed in type signatures
+   |                        help: replace with the correct return type: `S<'_>`
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
+  --> $DIR/infer-return-ty-for-fn-sig-issue-125488.rs:13:24
+   |
+LL |     fn f2(s: S<'_>) -> _ {
+   |                        ^
+   |                        |
+   |                        not allowed in type signatures
+   |                        help: replace with the correct return type: `S<'_>`
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
+  --> $DIR/infer-return-ty-for-fn-sig-issue-125488.rs:23:24
+   |
+LL |     fn f3(s: S<'_>) -> _ {
+   |                        ^
+   |                        |
+   |                        not allowed in type signatures
+   |                        help: replace with the correct return type: `S<'_>`
+
+error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
+  --> $DIR/infer-return-ty-for-fn-sig-issue-125488.rs:28:24
+   |
+LL |     fn f4(s: S<'_>) -> _ {
+   |                        ^
+   |                        |
+   |                        not allowed in type signatures
+   |                        help: replace with the correct return type: `S<'_>`
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0121`.
diff --git a/tests/ui/typeck/typeck_type_placeholder_item.rs b/tests/ui/typeck/typeck_type_placeholder_item.rs
index a95b44e807c..29a21a1f45f 100644
--- a/tests/ui/typeck/typeck_type_placeholder_item.rs
+++ b/tests/ui/typeck/typeck_type_placeholder_item.rs
@@ -47,7 +47,7 @@ impl Test9 {
 
 fn test11(x: &usize) -> &_ {
 //~^ ERROR the placeholder `_` is not allowed within types on item signatures for return types
-    &x //~ ERROR cannot return reference to function parameter
+    &x
 }
 
 unsafe fn test12(x: *const usize) -> *const *const _ {
diff --git a/tests/ui/typeck/typeck_type_placeholder_item.stderr b/tests/ui/typeck/typeck_type_placeholder_item.stderr
index 7977504dae1..9d295f88da5 100644
--- a/tests/ui/typeck/typeck_type_placeholder_item.stderr
+++ b/tests/ui/typeck/typeck_type_placeholder_item.stderr
@@ -158,7 +158,7 @@ LL | fn test11(x: &usize) -> &_ {
    |                         -^
    |                         ||
    |                         |not allowed in type signatures
-   |                         help: replace with the correct return type: `&'static &'static usize`
+   |                         help: replace with the correct return type: `&&usize`
 
 error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
   --> $DIR/typeck_type_placeholder_item.rs:53:52
@@ -687,13 +687,7 @@ help: add `#![feature(const_trait_impl)]` to the crate attributes to enable
 LL + #![feature(const_trait_impl)]
    |
 
-error[E0515]: cannot return reference to function parameter `x`
-  --> $DIR/typeck_type_placeholder_item.rs:50:5
-   |
-LL |     &x
-   |     ^^ returns a reference to data owned by the current function
-
-error: aborting due to 75 previous errors
+error: aborting due to 74 previous errors
 
-Some errors have detailed explanations: E0015, E0046, E0121, E0282, E0403, E0515.
+Some errors have detailed explanations: E0015, E0046, E0121, E0282, E0403.
 For more information about an error, try `rustc --explain E0015`.
diff --git a/tests/ui/used.stderr b/tests/ui/used.stderr
index ea77f129d8e..c586dc72293 100644
--- a/tests/ui/used.stderr
+++ b/tests/ui/used.stderr
@@ -3,24 +3,32 @@ error: attribute must be applied to a `static` variable
    |
 LL | #[used]
    | ^^^^^^^
+LL | fn foo() {}
+   | ----------- but this is a function
 
 error: attribute must be applied to a `static` variable
   --> $DIR/used.rs:7:1
    |
 LL | #[used]
    | ^^^^^^^
+LL | struct Foo {}
+   | ------------- but this is a struct
 
 error: attribute must be applied to a `static` variable
   --> $DIR/used.rs:10:1
    |
 LL | #[used]
    | ^^^^^^^
+LL | trait Bar {}
+   | ------------ but this is a trait
 
 error: attribute must be applied to a `static` variable
   --> $DIR/used.rs:13:1
    |
 LL | #[used]
    | ^^^^^^^
+LL | impl Bar for Foo {}
+   | ------------------- but this is a implementation block
 
 error: aborting due to 4 previous errors
 
diff --git a/triagebot.toml b/triagebot.toml
index 62e0917efab..8ae454d412a 100644
--- a/triagebot.toml
+++ b/triagebot.toml
@@ -331,6 +331,7 @@ trigger_files = [
     "src/tools/tidy",
     "src/tools/rustdoc-gui-test",
     "src/tools/libcxx-version",
+    "src/tools/rustc-perf-wrapper",
 ]
 
 [autolabel."T-infra"]