Auto merge of #99707 - JohnTitor:rollup-74rb8vq, r=JohnTitor

Rollup of 7 pull requests

Successful merges:

 - #95040 (protect `std::io::Take::limit` from overflow in `read`)
 - #95916 (kmc-solid: Use `libc::abort` to abort a program)
 - #99494 (Use non-relocatable code in nofile-limit.rs test)
 - #99581 (Improve error messages involving `derive` and `packed`.)
 - #99643 (Add `sign-ext` target feature to the WASM target)
 - #99659 (Use `VecMap::get` in `ConstraintLocator::check`)
 - #99690 (add miri-track-caller to more intrinsic-exposing methods)

Failed merges:

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

compiler/rustc_codegen_ssa/src/target_features.rs

@@ -249,6 +249,7 @@ const WASM_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[
     ("bulk-memory", Some(sym::wasm_target_feature)),
     ("mutable-globals", Some(sym::wasm_target_feature)),
     ("reference-types", Some(sym::wasm_target_feature)),
+    ("sign-ext", Some(sym::wasm_target_feature)),
 ];
 
 const BPF_ALLOWED_FEATURES: &[(&str, Option<Symbol>)] = &[("alu32", Some(sym::bpf_target_feature))];

compiler/rustc_mir_transform/src/check_packed_ref.rs

@@ -36,13 +36,16 @@ fn unsafe_derive_on_repr_packed(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     tcx.struct_span_lint_hir(UNALIGNED_REFERENCES, lint_hir_id, tcx.def_span(def_id), |lint| {
         // FIXME: when we make this a hard error, this should have its
         // own error code.
-        let message = if tcx.generics_of(def_id).own_requires_monomorphization() {
+        let extra = if tcx.generics_of(def_id).own_requires_monomorphization() {
-            "`#[derive]` can't be used on a `#[repr(packed)]` struct with \
+            "with type or const parameters"
-             type or const parameters (error E0133)"
         } else {
-            "`#[derive]` can't be used on a `#[repr(packed)]` struct that \
+            "that does not derive `Copy`"
-             does not derive Copy (error E0133)"
         };
+        let message = format!(
+            "`{}` can't be derived on this `#[repr(packed)]` struct {} (error E0133)",
+            tcx.item_name(tcx.trait_id_of_impl(def_id.to_def_id()).expect("derived trait name")),
+            extra
+        );
         lint.build(message).emit();
     });
 }

compiler/rustc_typeck/src/collect/type_of.rs

@@ -538,9 +538,9 @@ fn find_opaque_ty_constraints(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Ty<'_> {
 
     impl ConstraintLocator<'_> {
         #[instrument(skip(self), level = "debug")]
-        fn check(&mut self, def_id: LocalDefId) {
+        fn check(&mut self, item_def_id: LocalDefId) {
             // Don't try to check items that cannot possibly constrain the type.
-            if !self.tcx.has_typeck_results(def_id) {
+            if !self.tcx.has_typeck_results(item_def_id) {
                 debug!("no constraint: no typeck results");
                 return;
             }
@@ -555,26 +555,20 @@ fn find_opaque_ty_constraints(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Ty<'_> {
             // // because we again need to reveal `Foo` so we can check whether the
             // // constant does not contain interior mutability.
             // ```
-            let tables = self.tcx.typeck(def_id);
+            let tables = self.tcx.typeck(item_def_id);
             if let Some(_) = tables.tainted_by_errors {
                 self.found = Some(ty::OpaqueHiddenType { span: DUMMY_SP, ty: self.tcx.ty_error() });
                 return;
             }
-            if tables.concrete_opaque_types.get(&self.def_id).is_none() {
+            if !tables.concrete_opaque_types.contains_key(&self.def_id) {
                 debug!("no constraints in typeck results");
                 return;
             }
             // Use borrowck to get the type with unerased regions.
-            let concrete_opaque_types = &self.tcx.mir_borrowck(def_id).concrete_opaque_types;
+            let concrete_opaque_types = &self.tcx.mir_borrowck(item_def_id).concrete_opaque_types;
             debug!(?concrete_opaque_types);
-            for &(def_id, concrete_type) in concrete_opaque_types {
+            if let Some(&concrete_type) = concrete_opaque_types.get(&self.def_id) {
-                if def_id != self.def_id {
-                    // Ignore constraints for other opaque types.
-                    continue;
-                }
-
                 debug!(?concrete_type, "found constraint");
-
                 if let Some(prev) = self.found {
                     if concrete_type.ty != prev.ty && !(concrete_type, prev).references_error() {
                         prev.report_mismatch(&concrete_type, self.tcx);

library/core/src/hint.rs

@@ -96,6 +96,7 @@ use crate::intrinsics;
 #[inline]
 #[stable(feature = "unreachable", since = "1.27.0")]
 #[rustc_const_stable(feature = "const_unreachable_unchecked", since = "1.57.0")]
+#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub const unsafe fn unreachable_unchecked() -> ! {
     // SAFETY: the safety contract for `intrinsics::unreachable` must
     // be upheld by the caller.

library/core/src/intrinsics.rs

@@ -2449,6 +2449,7 @@ pub(crate) fn is_nonoverlapping<T>(src: *const T, dst: *const T, count: usize) -
 #[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)]
 #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")]
 #[inline]
+#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub const unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize) {
     extern "rust-intrinsic" {
         #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")]
@@ -2535,6 +2536,7 @@ pub const unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: us
 #[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)]
 #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")]
 #[inline]
+#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) {
     extern "rust-intrinsic" {
         #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")]

library/core/src/mem/mod.rs

@@ -1124,6 +1124,7 @@ impl<T> fmt::Debug for Discriminant<T> {
 #[stable(feature = "discriminant_value", since = "1.21.0")]
 #[rustc_const_unstable(feature = "const_discriminant", issue = "69821")]
 #[cfg_attr(not(test), rustc_diagnostic_item = "mem_discriminant")]
+#[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
 pub const fn discriminant<T>(v: &T) -> Discriminant<T> {
     Discriminant(intrinsics::discriminant_value(v))
 }

library/core/src/num/int_macros.rs

@@ -449,6 +449,7 @@ macro_rules! int_impl {
                       without modifying the original"]
         #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
         #[inline(always)]
+        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
         pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
             // SAFETY: the caller must uphold the safety contract for
             // `unchecked_add`.
@@ -517,6 +518,7 @@ macro_rules! int_impl {
                       without modifying the original"]
         #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
         #[inline(always)]
+        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
         pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
             // SAFETY: the caller must uphold the safety contract for
             // `unchecked_sub`.
@@ -585,6 +587,7 @@ macro_rules! int_impl {
                       without modifying the original"]
         #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
         #[inline(always)]
+        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
         pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
             // SAFETY: the caller must uphold the safety contract for
             // `unchecked_mul`.
@@ -757,6 +760,7 @@ macro_rules! int_impl {
                       without modifying the original"]
         #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
         #[inline(always)]
+        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
         pub const unsafe fn unchecked_shl(self, rhs: Self) -> Self {
             // SAFETY: the caller must uphold the safety contract for
             // `unchecked_shl`.
@@ -803,6 +807,7 @@ macro_rules! int_impl {
                       without modifying the original"]
         #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
         #[inline(always)]
+        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
         pub const unsafe fn unchecked_shr(self, rhs: Self) -> Self {
             // SAFETY: the caller must uphold the safety contract for
             // `unchecked_shr`.

library/core/src/num/uint_macros.rs

@@ -459,6 +459,7 @@ macro_rules! uint_impl {
                       without modifying the original"]
         #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
         #[inline(always)]
+        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
         pub const unsafe fn unchecked_add(self, rhs: Self) -> Self {
             // SAFETY: the caller must uphold the safety contract for
             // `unchecked_add`.
@@ -528,6 +529,7 @@ macro_rules! uint_impl {
                       without modifying the original"]
         #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
         #[inline(always)]
+        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
         pub const unsafe fn unchecked_sub(self, rhs: Self) -> Self {
             // SAFETY: the caller must uphold the safety contract for
             // `unchecked_sub`.
@@ -574,6 +576,7 @@ macro_rules! uint_impl {
                       without modifying the original"]
         #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
         #[inline(always)]
+        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
         pub const unsafe fn unchecked_mul(self, rhs: Self) -> Self {
             // SAFETY: the caller must uphold the safety contract for
             // `unchecked_mul`.
@@ -933,6 +936,7 @@ macro_rules! uint_impl {
                       without modifying the original"]
         #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
         #[inline(always)]
+        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
         pub const unsafe fn unchecked_shl(self, rhs: Self) -> Self {
             // SAFETY: the caller must uphold the safety contract for
             // `unchecked_shl`.
@@ -979,6 +983,7 @@ macro_rules! uint_impl {
                       without modifying the original"]
         #[rustc_const_unstable(feature = "const_inherent_unchecked_arith", issue = "85122")]
         #[inline(always)]
+        #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
         pub const unsafe fn unchecked_shr(self, rhs: Self) -> Self {
             // SAFETY: the caller must uphold the safety contract for
             // `unchecked_shr`.

library/core/src/ptr/const_ptr.rs

@@ -449,6 +449,7 @@ impl<T: ?Sized> *const T {
     #[must_use = "returns a new pointer rather than modifying its argument"]
     #[rustc_const_stable(feature = "const_ptr_offset", since = "1.61.0")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn offset(self, count: isize) -> *const T
     where
         T: Sized,
@@ -471,6 +472,7 @@ impl<T: ?Sized> *const T {
     #[inline(always)]
     #[unstable(feature = "pointer_byte_offsets", issue = "96283")]
     #[rustc_const_unstable(feature = "const_pointer_byte_offsets", issue = "96283")]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn byte_offset(self, count: isize) -> Self {
         // SAFETY: the caller must uphold the safety contract for `offset`.
         let this = unsafe { self.cast::<u8>().offset(count).cast::<()>() };
@@ -641,6 +643,7 @@ impl<T: ?Sized> *const T {
     #[stable(feature = "ptr_offset_from", since = "1.47.0")]
     #[rustc_const_unstable(feature = "const_ptr_offset_from", issue = "92980")]
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn offset_from(self, origin: *const T) -> isize
     where
         T: Sized,
@@ -663,6 +666,7 @@ impl<T: ?Sized> *const T {
     #[inline(always)]
     #[unstable(feature = "pointer_byte_offsets", issue = "96283")]
     #[rustc_const_unstable(feature = "const_pointer_byte_offsets", issue = "96283")]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn byte_offset_from(self, origin: *const T) -> isize {
         // SAFETY: the caller must uphold the safety contract for `offset_from`.
         unsafe { self.cast::<u8>().offset_from(origin.cast::<u8>()) }
@@ -731,6 +735,7 @@ impl<T: ?Sized> *const T {
     #[unstable(feature = "ptr_sub_ptr", issue = "95892")]
     #[rustc_const_unstable(feature = "const_ptr_sub_ptr", issue = "95892")]
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn sub_ptr(self, origin: *const T) -> usize
     where
         T: Sized,
@@ -862,6 +867,7 @@ impl<T: ?Sized> *const T {
     #[must_use = "returns a new pointer rather than modifying its argument"]
     #[rustc_const_stable(feature = "const_ptr_offset", since = "1.61.0")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn add(self, count: usize) -> Self
     where
         T: Sized,
@@ -884,6 +890,7 @@ impl<T: ?Sized> *const T {
     #[inline(always)]
     #[unstable(feature = "pointer_byte_offsets", issue = "96283")]
     #[rustc_const_unstable(feature = "const_pointer_byte_offsets", issue = "96283")]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn byte_add(self, count: usize) -> Self {
         // SAFETY: the caller must uphold the safety contract for `add`.
         let this = unsafe { self.cast::<u8>().add(count).cast::<()>() };
@@ -946,6 +953,7 @@ impl<T: ?Sized> *const T {
     #[must_use = "returns a new pointer rather than modifying its argument"]
     #[rustc_const_stable(feature = "const_ptr_offset", since = "1.61.0")]
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn sub(self, count: usize) -> Self
     where
         T: Sized,
@@ -969,6 +977,7 @@ impl<T: ?Sized> *const T {
     #[inline(always)]
     #[unstable(feature = "pointer_byte_offsets", issue = "96283")]
     #[rustc_const_unstable(feature = "const_pointer_byte_offsets", issue = "96283")]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn byte_sub(self, count: usize) -> Self {
         // SAFETY: the caller must uphold the safety contract for `sub`.
         let this = unsafe { self.cast::<u8>().sub(count).cast::<()>() };
@@ -1205,6 +1214,7 @@ impl<T: ?Sized> *const T {
     #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")]
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn copy_to(self, dest: *mut T, count: usize)
     where
         T: Sized,
@@ -1224,6 +1234,7 @@ impl<T: ?Sized> *const T {
     #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")]
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn copy_to_nonoverlapping(self, dest: *mut T, count: usize)
     where
         T: Sized,

library/core/src/ptr/mut_ptr.rs

@@ -461,6 +461,7 @@ impl<T: ?Sized> *mut T {
     #[must_use = "returns a new pointer rather than modifying its argument"]
     #[rustc_const_stable(feature = "const_ptr_offset", since = "1.61.0")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn offset(self, count: isize) -> *mut T
     where
         T: Sized,
@@ -485,6 +486,7 @@ impl<T: ?Sized> *mut T {
     #[inline(always)]
     #[unstable(feature = "pointer_byte_offsets", issue = "96283")]
     #[rustc_const_unstable(feature = "const_pointer_byte_offsets", issue = "96283")]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn byte_offset(self, count: isize) -> Self {
         // SAFETY: the caller must uphold the safety contract for `offset`.
         let this = unsafe { self.cast::<u8>().offset(count).cast::<()>() };
@@ -824,6 +826,7 @@ impl<T: ?Sized> *mut T {
     #[stable(feature = "ptr_offset_from", since = "1.47.0")]
     #[rustc_const_unstable(feature = "const_ptr_offset_from", issue = "92980")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn offset_from(self, origin: *const T) -> isize
     where
         T: Sized,
@@ -844,6 +847,7 @@ impl<T: ?Sized> *mut T {
     #[inline(always)]
     #[unstable(feature = "pointer_byte_offsets", issue = "96283")]
     #[rustc_const_unstable(feature = "const_pointer_byte_offsets", issue = "96283")]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn byte_offset_from(self, origin: *const T) -> isize {
         // SAFETY: the caller must uphold the safety contract for `offset_from`.
         unsafe { self.cast::<u8>().offset_from(origin.cast::<u8>()) }
@@ -913,6 +917,7 @@ impl<T: ?Sized> *mut T {
     #[unstable(feature = "ptr_sub_ptr", issue = "95892")]
     #[rustc_const_unstable(feature = "const_ptr_sub_ptr", issue = "95892")]
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn sub_ptr(self, origin: *const T) -> usize
     where
         T: Sized,
@@ -976,6 +981,7 @@ impl<T: ?Sized> *mut T {
     #[must_use = "returns a new pointer rather than modifying its argument"]
     #[rustc_const_stable(feature = "const_ptr_offset", since = "1.61.0")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn add(self, count: usize) -> Self
     where
         T: Sized,
@@ -998,6 +1004,7 @@ impl<T: ?Sized> *mut T {
     #[inline(always)]
     #[unstable(feature = "pointer_byte_offsets", issue = "96283")]
     #[rustc_const_unstable(feature = "const_pointer_byte_offsets", issue = "96283")]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn byte_add(self, count: usize) -> Self {
         // SAFETY: the caller must uphold the safety contract for `add`.
         let this = unsafe { self.cast::<u8>().add(count).cast::<()>() };
@@ -1060,6 +1067,7 @@ impl<T: ?Sized> *mut T {
     #[must_use = "returns a new pointer rather than modifying its argument"]
     #[rustc_const_stable(feature = "const_ptr_offset", since = "1.61.0")]
     #[inline]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn sub(self, count: usize) -> Self
     where
         T: Sized,
@@ -1083,6 +1091,7 @@ impl<T: ?Sized> *mut T {
     #[inline(always)]
     #[unstable(feature = "pointer_byte_offsets", issue = "96283")]
     #[rustc_const_unstable(feature = "const_pointer_byte_offsets", issue = "96283")]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn byte_sub(self, count: usize) -> Self {
         // SAFETY: the caller must uphold the safety contract for `sub`.
         let this = unsafe { self.cast::<u8>().sub(count).cast::<()>() };
@@ -1319,6 +1328,7 @@ impl<T: ?Sized> *mut T {
     #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")]
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn copy_to(self, dest: *mut T, count: usize)
     where
         T: Sized,
@@ -1338,6 +1348,7 @@ impl<T: ?Sized> *mut T {
     #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")]
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn copy_to_nonoverlapping(self, dest: *mut T, count: usize)
     where
         T: Sized,
@@ -1357,6 +1368,7 @@ impl<T: ?Sized> *mut T {
     #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")]
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn copy_from(self, src: *const T, count: usize)
     where
         T: Sized,
@@ -1376,6 +1388,7 @@ impl<T: ?Sized> *mut T {
     #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.63.0")]
     #[stable(feature = "pointer_methods", since = "1.26.0")]
     #[inline(always)]
+    #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
     pub const unsafe fn copy_from_nonoverlapping(self, src: *const T, count: usize)
     where
         T: Sized,

library/panic_abort/src/lib.rs

@@ -37,12 +37,11 @@ pub unsafe fn __rust_start_panic(_payload: *mut &mut dyn BoxMeUp) -> u32 {
     abort();
 
     cfg_if::cfg_if! {
-        if #[cfg(unix)] {
+        if #[cfg(any(unix, target_os = "solid_asp3"))] {
             unsafe fn abort() -> ! {
                 libc::abort();
             }
         } else if #[cfg(any(target_os = "hermit",
-                            target_os = "solid_asp3",
                             all(target_vendor = "fortanix", target_env = "sgx")
         ))] {
             unsafe fn abort() -> ! {

library/std/src/io/mod.rs

@@ -2577,6 +2577,7 @@ impl<T: Read> Read for Take<T> {
 
         let max = cmp::min(buf.len() as u64, self.limit) as usize;
         let n = self.inner.read(&mut buf[..max])?;
+        assert!(n as u64 <= self.limit, "number of read bytes exceeds limit");
         self.limit -= n as u64;
         Ok(n)
     }

library/std/src/io/tests.rs

@@ -583,6 +583,25 @@ fn test_write_all_vectored() {
     }
 }
 
+// Issue 94981
+#[test]
+#[should_panic = "number of read bytes exceeds limit"]
+fn test_take_wrong_length() {
+    struct LieAboutSize(bool);
+
+    impl Read for LieAboutSize {
+        fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+            // Lie about the read size at first time of read.
+            if core::mem::take(&mut self.0) { Ok(buf.len() + 1) } else { Ok(buf.len()) }
+        }
+    }
+
+    let mut buffer = vec![0; 4];
+    let mut reader = LieAboutSize(true).take(4);
+    // Primed the `Limit` by lying about the read size.
+    let _ = reader.read(&mut buffer[..]);
+}
+
 #[bench]
 fn bench_take_read(b: &mut test::Bencher) {
     b.iter(|| {

library/std/src/sys/solid/abi/mod.rs

@@ -4,32 +4,6 @@ mod fs;
 pub mod sockets;
 pub use self::fs::*;
 
-#[inline(always)]
-pub fn breakpoint_program_exited(tid: usize) {
-    unsafe {
-        match () {
-            // SOLID_BP_PROGRAM_EXITED = 15
-            #[cfg(target_arch = "arm")]
-            () => core::arch::asm!("bkpt #15", in("r0") tid),
-            #[cfg(target_arch = "aarch64")]
-            () => core::arch::asm!("hlt #15", in("x0") tid),
-        }
-    }
-}
-
-#[inline(always)]
-pub fn breakpoint_abort() {
-    unsafe {
-        match () {
-            // SOLID_BP_CSABORT = 16
-            #[cfg(target_arch = "arm")]
-            () => core::arch::asm!("bkpt #16"),
-            #[cfg(target_arch = "aarch64")]
-            () => core::arch::asm!("hlt #16"),
-        }
-    }
-}
-
 // `solid_types.h`
 pub use super::itron::abi::{ER, ER_ID, E_TMOUT, ID};
 

library/std/src/sys/solid/mod.rs

@@ -76,20 +76,9 @@ pub fn decode_error_kind(code: i32) -> crate::io::ErrorKind {
     error::decode_error_kind(code)
 }
 
-#[inline(always)]
+#[inline]
 pub fn abort_internal() -> ! {
-    loop {
+    unsafe { libc::abort() }
-        abi::breakpoint_abort();
-    }
-}
-
-// This function is needed by the panic runtime. The symbol is named in
-// pre-link args for the target specification, so keep that in sync.
-#[cfg(not(test))]
-#[no_mangle]
-// NB. used by both libunwind and libpanic_abort
-pub extern "C" fn __rust_abort() {
-    abort_internal();
 }
 
 pub fn hashmap_random_keys() -> (u64, u64) {

library/std/src/sys/solid/os.rs

@@ -11,7 +11,7 @@ use crate::path::{self, PathBuf};
 use crate::sys_common::rwlock::StaticRwLock;
 use crate::vec;
 
-use super::{abi, error, itron, memchr};
+use super::{error, itron, memchr};
 
 // `solid` directly maps `errno`s to μITRON error codes.
 impl itron::error::ItronError {
@@ -184,11 +184,8 @@ pub fn home_dir() -> Option<PathBuf> {
     None
 }
 
-pub fn exit(_code: i32) -> ! {
+pub fn exit(code: i32) -> ! {
-    let tid = itron::task::try_current_task_id().unwrap_or(0);
+    rtabort!("exit({}) called", code);
-    loop {
-        abi::breakpoint_program_exited(tid as usize);
-    }
 }
 
 pub fn getpid() -> u32 {

src/test/ui/derives/deriving-with-repr-packed.rs

@@ -1,29 +1,43 @@
 #![deny(unaligned_references)]
 
-// check that derive on a packed struct with non-Copy fields
+// Check that deriving certain builtin traits on certain packed structs cause
-// correctly. This can't be made to work perfectly because
+// errors. This happens when the derived trait would need to use a potentially
-// we can't just use the field from the struct as it might
+// misaligned reference. But there are two cases that are allowed:
-// not be aligned.
+// - If all the fields within the struct meet the required alignment: 1 for
+//   `repr(packed)`, or `N` for `repr(packed(N))`.
+// - If `Default` is the only trait derived, because it doesn't involve any
+//   references.
 
-#[derive(Copy, Clone, PartialEq, Eq)]
+#[derive(Copy, Clone, Default, PartialEq, Eq)]
-//~^ ERROR `#[derive]` can't be used
+//~^ ERROR `Clone` can't be derived on this `#[repr(packed)]` struct with type or const parameters
 //~| hard error
-//~^^^ ERROR `#[derive]` can't be used
+//~^^^ ERROR `PartialEq` can't be derived on this `#[repr(packed)]` struct with type or const parameters
 //~| hard error
 #[repr(packed)]
 pub struct Foo<T>(T, T, T);
 
-#[derive(PartialEq, Eq)]
+#[derive(Default, Hash)]
-//~^ ERROR `#[derive]` can't be used
+//~^ ERROR `Hash` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy`
 //~| hard error
 #[repr(packed)]
 pub struct Bar(u32, u32, u32);
 
-#[derive(PartialEq)]
+// This one is fine because the field alignment is 1.
+#[derive(Default, Hash)]
+#[repr(packed)]
+pub struct Bar2(u8, i8, bool);
+
+// This one is fine because the field alignment is 2, matching `packed(2)`.
+#[derive(Default, Hash)]
+#[repr(packed(2))]
+pub struct Bar3(u16, i16, bool);
+
+// This one is fine because it's not packed.
+#[derive(Debug, Default)]
 struct Y(usize);
 
-#[derive(PartialEq)]
+#[derive(Debug, Default)]
-//~^ ERROR `#[derive]` can't be used
+//~^ ERROR `Debug` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy`
 //~| hard error
 #[repr(packed)]
 struct X(Y);

src/test/ui/derives/deriving-with-repr-packed.stderr

@@ -1,7 +1,7 @@
-error: `#[derive]` can't be used on a `#[repr(packed)]` struct with type or const parameters (error E0133)
+error: `Clone` can't be derived on this `#[repr(packed)]` struct with type or const parameters (error E0133)
-  --> $DIR/deriving-with-repr-packed.rs:8:16
+  --> $DIR/deriving-with-repr-packed.rs:11:16
    |
-LL | #[derive(Copy, Clone, PartialEq, Eq)]
+LL | #[derive(Copy, Clone, Default, PartialEq, Eq)]
    |                ^^^^^
    |
 note: the lint level is defined here
@@ -13,43 +13,43 @@ LL | #![deny(unaligned_references)]
    = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
    = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: `#[derive]` can't be used on a `#[repr(packed)]` struct with type or const parameters (error E0133)
+error: `PartialEq` can't be derived on this `#[repr(packed)]` struct with type or const parameters (error E0133)
-  --> $DIR/deriving-with-repr-packed.rs:8:23
+  --> $DIR/deriving-with-repr-packed.rs:11:32
    |
-LL | #[derive(Copy, Clone, PartialEq, Eq)]
+LL | #[derive(Copy, Clone, Default, PartialEq, Eq)]
-   |                       ^^^^^^^^^
+   |                                ^^^^^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
    = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: `#[derive]` can't be used on a `#[repr(packed)]` struct that does not derive Copy (error E0133)
+error: `Hash` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy` (error E0133)
-  --> $DIR/deriving-with-repr-packed.rs:16:10
+  --> $DIR/deriving-with-repr-packed.rs:19:19
    |
-LL | #[derive(PartialEq, Eq)]
+LL | #[derive(Default, Hash)]
-   |          ^^^^^^^^^
+   |                   ^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
-   = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: `#[derive]` can't be used on a `#[repr(packed)]` struct that does not derive Copy (error E0133)
+error: `Debug` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy` (error E0133)
-  --> $DIR/deriving-with-repr-packed.rs:25:10
+  --> $DIR/deriving-with-repr-packed.rs:39:10
    |
-LL | #[derive(PartialEq)]
+LL | #[derive(Debug, Default)]
-   |          ^^^^^^^^^
+   |          ^^^^^
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
-   = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 error: aborting due to 4 previous errors
 
 Future incompatibility report: Future breakage diagnostic:
-error: `#[derive]` can't be used on a `#[repr(packed)]` struct with type or const parameters (error E0133)
+error: `Clone` can't be derived on this `#[repr(packed)]` struct with type or const parameters (error E0133)
-  --> $DIR/deriving-with-repr-packed.rs:8:16
+  --> $DIR/deriving-with-repr-packed.rs:11:16
    |
-LL | #[derive(Copy, Clone, PartialEq, Eq)]
+LL | #[derive(Copy, Clone, Default, PartialEq, Eq)]
    |                ^^^^^
    |
 note: the lint level is defined here
@@ -62,11 +62,11 @@ LL | #![deny(unaligned_references)]
    = note: this error originates in the derive macro `Clone` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 Future breakage diagnostic:
-error: `#[derive]` can't be used on a `#[repr(packed)]` struct with type or const parameters (error E0133)
+error: `PartialEq` can't be derived on this `#[repr(packed)]` struct with type or const parameters (error E0133)
-  --> $DIR/deriving-with-repr-packed.rs:8:23
+  --> $DIR/deriving-with-repr-packed.rs:11:32
    |
-LL | #[derive(Copy, Clone, PartialEq, Eq)]
+LL | #[derive(Copy, Clone, Default, PartialEq, Eq)]
-   |                       ^^^^^^^^^
+   |                                ^^^^^^^^^
    |
 note: the lint level is defined here
   --> $DIR/deriving-with-repr-packed.rs:1:9
@@ -78,11 +78,11 @@ LL | #![deny(unaligned_references)]
    = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 Future breakage diagnostic:
-error: `#[derive]` can't be used on a `#[repr(packed)]` struct that does not derive Copy (error E0133)
+error: `Hash` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy` (error E0133)
-  --> $DIR/deriving-with-repr-packed.rs:16:10
+  --> $DIR/deriving-with-repr-packed.rs:19:19
    |
-LL | #[derive(PartialEq, Eq)]
+LL | #[derive(Default, Hash)]
-   |          ^^^^^^^^^
+   |                   ^^^^
    |
 note: the lint level is defined here
   --> $DIR/deriving-with-repr-packed.rs:1:9
@@ -91,14 +91,14 @@ LL | #![deny(unaligned_references)]
    |         ^^^^^^^^^^^^^^^^^^^^
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
-   = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `Hash` (in Nightly builds, run with -Z macro-backtrace for more info)
 
 Future breakage diagnostic:
-error: `#[derive]` can't be used on a `#[repr(packed)]` struct that does not derive Copy (error E0133)
+error: `Debug` can't be derived on this `#[repr(packed)]` struct that does not derive `Copy` (error E0133)
-  --> $DIR/deriving-with-repr-packed.rs:25:10
+  --> $DIR/deriving-with-repr-packed.rs:39:10
    |
-LL | #[derive(PartialEq)]
+LL | #[derive(Debug, Default)]
-   |          ^^^^^^^^^
+   |          ^^^^^
    |
 note: the lint level is defined here
   --> $DIR/deriving-with-repr-packed.rs:1:9
@@ -107,5 +107,5 @@ LL | #![deny(unaligned_references)]
    |         ^^^^^^^^^^^^^^^^^^^^
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #82523 <https://github.com/rust-lang/rust/issues/82523>
-   = note: this error originates in the derive macro `PartialEq` (in Nightly builds, run with -Z macro-backtrace for more info)
+   = note: this error originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)
 

src/test/ui/process/nofile-limit.rs

@@ -6,7 +6,7 @@
 // dont-check-compiler-stderr
 // only-linux
 // no-prefer-dynamic
-// compile-flags: -Ctarget-feature=+crt-static -Crpath=no
+// compile-flags: -Ctarget-feature=+crt-static -Crpath=no -Crelocation-model=static
 #![feature(exit_status_error)]
 #![feature(rustc_private)]
 extern crate libc;