Rollup of 15 pull requests

Cargo.lock

@@ -4349,6 +4349,7 @@ dependencies = [
  "rustc_ast_lowering",
  "rustc_ast_pretty",
  "rustc_attr_data_structures",
+ "rustc_attr_parsing",
  "rustc_data_structures",
  "rustc_errors",
  "rustc_expand",
@@ -5230,9 +5231,9 @@ dependencies = [
 
 [[package]]
 name = "sysinfo"
-version = "0.35.2"
+version = "0.36.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3c3ffa3e4ff2b324a57f7aeb3c349656c7b127c3c189520251a648102a92496e"
+checksum = "aab138f5c1bb35231de19049060a87977ad23e04f2303e953bc5c2947ac7dec4"
 dependencies = [
  "libc",
  "objc2-core-foundation",

compiler/rustc_attr_parsing/src/context.rs

@@ -735,6 +735,11 @@ impl<'sess, S: Stage> AttributeParser<'sess, S> {
         attributes
     }
 
+    /// Returns whether there is a parser for an attribute with this name
+    pub fn is_parsed_attribute(path: &[Symbol]) -> bool {
+        Late::parsers().0.contains_key(path)
+    }
+
     fn lower_attr_args(&self, args: &ast::AttrArgs, lower_span: impl Fn(Span) -> Span) -> AttrArgs {
         match args {
             ast::AttrArgs::Empty => AttrArgs::Empty,

compiler/rustc_const_eval/src/interpret/memory.rs

@@ -1498,7 +1498,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             dest_alloc
                 .write_uninit(&tcx, dest_range)
                 .map_err(|e| e.to_interp_error(dest_alloc_id))?;
-            // We can forget about the provenance, this is all not initialized anyway.
+            // `write_uninit` also resets the provenance, so we are done.
             return interp_ok(());
         }
 

compiler/rustc_middle/src/mir/interpret/allocation.rs

@@ -101,6 +101,8 @@ pub struct Allocation<Prov: Provenance = CtfeProvenance, Extra = (), Bytes = Box
     /// at the given offset.
     provenance: ProvenanceMap<Prov>,
     /// Denotes which part of this allocation is initialized.
+    ///
+    /// Invariant: the uninitialized parts have no provenance.
     init_mask: InitMask,
     /// The alignment of the allocation to detect unaligned reads.
     /// (`Align` guarantees that this is a power of two.)
@@ -796,24 +798,19 @@ impl<Prov: Provenance, Extra, Bytes: AllocBytes> Allocation<Prov, Extra, Bytes>
         Ok(())
     }
 
-    /// Initialize all previously uninitialized bytes in the entire allocation, and set
-    /// provenance of everything to `Wildcard`. Before calling this, make sure all
-    /// provenance in this allocation is exposed!
-    pub fn prepare_for_native_access(&mut self) {
-        let full_range = AllocRange { start: Size::ZERO, size: Size::from_bytes(self.len()) };
-        // Overwrite uninitialized bytes with 0, to ensure we don't leak whatever their value happens to be.
-        for chunk in self.init_mask.range_as_init_chunks(full_range) {
-            if !chunk.is_init() {
-                let uninit_bytes = &mut self.bytes
-                    [chunk.range().start.bytes_usize()..chunk.range().end.bytes_usize()];
-                uninit_bytes.fill(0);
-            }
-        }
-        // Mark everything as initialized now.
-        self.mark_init(full_range, true);
-
-        // Set provenance of all bytes to wildcard.
-        self.provenance.write_wildcards(self.len());
+    /// Mark all bytes in the given range as initialised and reset the provenance
+    /// to wildcards. This entirely breaks the normal mechanisms for tracking
+    /// initialisation and is only provided for Miri operating in native-lib
+    /// mode. UB will be missed if the underlying bytes were not actually written to.
+    ///
+    /// If `range` is `None`, defaults to performing this on the whole allocation.
+    pub fn process_native_write(&mut self, cx: &impl HasDataLayout, range: Option<AllocRange>) {
+        let range = range.unwrap_or_else(|| AllocRange {
+            start: Size::ZERO,
+            size: Size::from_bytes(self.len()),
+        });
+        self.mark_init(range, true);
+        self.provenance.write_wildcards(cx, range);
     }
 
     /// Remove all provenance in the given memory range.

compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs

@@ -212,21 +212,37 @@ impl<Prov: Provenance> ProvenanceMap<Prov> {
         Ok(())
     }
 
-    /// Overwrites all provenance in the allocation with wildcard provenance.
+    /// Overwrites all provenance in the given range with wildcard provenance.
+    /// Pointers partially overwritten will have their provenances preserved
+    /// bytewise on their remaining bytes.
     ///
     /// Provided for usage in Miri and panics otherwise.
-    pub fn write_wildcards(&mut self, alloc_size: usize) {
+    pub fn write_wildcards(&mut self, cx: &impl HasDataLayout, range: AllocRange) {
         assert!(
             Prov::OFFSET_IS_ADDR,
             "writing wildcard provenance is not supported when `OFFSET_IS_ADDR` is false"
         );
         let wildcard = Prov::WILDCARD.unwrap();
 
-        // Remove all pointer provenances, then write wildcards into the whole byte range.
-        self.ptrs.clear();
-        let last = Size::from_bytes(alloc_size);
         let bytes = self.bytes.get_or_insert_with(Box::default);
-        for offset in Size::ZERO..last {
+
+        // Remove pointer provenances that overlap with the range, then readd the edge ones bytewise.
+        let ptr_range = Self::adjusted_range_ptrs(range, cx);
+        let ptrs = self.ptrs.range(ptr_range.clone());
+        if let Some((offset, prov)) = ptrs.first() {
+            for byte_ofs in *offset..range.start {
+                bytes.insert(byte_ofs, *prov);
+            }
+        }
+        if let Some((offset, prov)) = ptrs.last() {
+            for byte_ofs in range.end()..*offset + cx.data_layout().pointer_size() {
+                bytes.insert(byte_ofs, *prov);
+            }
+        }
+        self.ptrs.remove_range(ptr_range);
+
+        // Overwrite bytewise provenance.
+        for offset in range.start..range.end() {
             bytes.insert(offset, wildcard);
         }
     }

compiler/rustc_passes/Cargo.toml

@@ -10,6 +10,7 @@ rustc_ast = { path = "../rustc_ast" }
 rustc_ast_lowering = { path = "../rustc_ast_lowering" }
 rustc_ast_pretty = { path = "../rustc_ast_pretty" }
 rustc_attr_data_structures = { path = "../rustc_attr_data_structures" }
+rustc_attr_parsing = { path = "../rustc_attr_parsing" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_expand = { path = "../rustc_expand" }

compiler/rustc_passes/src/check_attr.rs

@@ -7,10 +7,12 @@
 
 use std::cell::Cell;
 use std::collections::hash_map::Entry;
+use std::slice;
 
 use rustc_abi::{Align, ExternAbi, Size};
 use rustc_ast::{AttrStyle, LitKind, MetaItemInner, MetaItemKind, ast};
 use rustc_attr_data_structures::{AttributeKind, InlineAttr, ReprAttr, find_attr};
+use rustc_attr_parsing::{AttributeParser, Late};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{Applicability, DiagCtxtHandle, IntoDiagArg, MultiSpan, StashKey};
 use rustc_feature::{AttributeDuplicates, AttributeType, BUILTIN_ATTRIBUTE_MAP, BuiltinAttribute};
@@ -384,11 +386,18 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             | sym::custom_mir,
                             ..
                         ] => {}
-                        [name, ..] => {
+                        [name, rest@..] => {
                             match BUILTIN_ATTRIBUTE_MAP.get(name) {
                                 // checked below
                                 Some(BuiltinAttribute { type_: AttributeType::CrateLevel, .. }) => {}
                                 Some(_) => {
+                                    if rest.len() > 0 && AttributeParser::<Late>::is_parsed_attribute(slice::from_ref(name)) {
+                                        // Check if we tried to use a builtin attribute as an attribute namespace, like `#[must_use::skip]`.
+                                        // This check is here to solve https://github.com/rust-lang/rust/issues/137590
+                                        // An error is already produced for this case elsewhere
+                                        continue
+                                    }
+
                                     // FIXME: differentiate between unstable and internal attributes just
                                     // like we do with features instead of just accepting `rustc_`
                                     // attributes by name. That should allow trimming the above list, too.

library/core/src/cmp.rs

@@ -248,7 +248,7 @@ use crate::ops::ControlFlow;
 )]
 #[rustc_diagnostic_item = "PartialEq"]
 #[const_trait]
-#[rustc_const_unstable(feature = "const_trait_impl", issue = "67792")]
+#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
 pub trait PartialEq<Rhs: PointeeSized = Self>: PointeeSized {
     /// Tests for `self` and `other` values to be equal, and is used by `==`.
     #[must_use]
@@ -1809,7 +1809,7 @@ mod impls {
     macro_rules! partial_eq_impl {
         ($($t:ty)*) => ($(
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
+            #[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
             impl const PartialEq for $t {
                 #[inline]
                 fn eq(&self, other: &Self) -> bool { *self == *other }
@@ -2017,7 +2017,7 @@ mod impls {
     // & pointers
 
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
+    #[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
     impl<A: PointeeSized, B: PointeeSized> const PartialEq<&B> for &A
     where
         A: ~const PartialEq<B>,
@@ -2089,7 +2089,7 @@ mod impls {
     // &mut pointers
 
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
+    #[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
     impl<A: PointeeSized, B: PointeeSized> const PartialEq<&mut B> for &mut A
     where
         A: ~const PartialEq<B>,
@@ -2159,7 +2159,7 @@ mod impls {
     impl<A: PointeeSized> Eq for &mut A where A: Eq {}
 
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
+    #[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
     impl<A: PointeeSized, B: PointeeSized> const PartialEq<&mut B> for &A
     where
         A: ~const PartialEq<B>,
@@ -2175,7 +2175,7 @@ mod impls {
     }
 
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_cmp", issue = "92391")]
+    #[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
     impl<A: PointeeSized, B: PointeeSized> const PartialEq<&B> for &mut A
     where
         A: ~const PartialEq<B>,

library/core/src/convert/mod.rs

@@ -445,6 +445,8 @@ pub trait AsMut<T: PointeeSized>: PointeeSized {
 #[rustc_diagnostic_item = "Into"]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(search_unbox)]
+#[rustc_const_unstable(feature = "const_from", issue = "143773")]
+#[const_trait]
 pub trait Into<T>: Sized {
     /// Converts this type into the (usually inferred) input type.
     #[must_use]
@@ -580,6 +582,8 @@ pub trait Into<T>: Sized {
     note = "to coerce a `{T}` into a `{Self}`, use `&*` as a prefix",
 ))]
 #[doc(search_unbox)]
+#[rustc_const_unstable(feature = "const_from", issue = "143773")]
+#[const_trait]
 pub trait From<T>: Sized {
     /// Converts to this type from the input type.
     #[rustc_diagnostic_item = "from_fn"]
@@ -607,6 +611,8 @@ pub trait From<T>: Sized {
 /// [`Into`], see there for details.
 #[rustc_diagnostic_item = "TryInto"]
 #[stable(feature = "try_from", since = "1.34.0")]
+#[rustc_const_unstable(feature = "const_from", issue = "143773")]
+#[const_trait]
 pub trait TryInto<T>: Sized {
     /// The type returned in the event of a conversion error.
     #[stable(feature = "try_from", since = "1.34.0")]
@@ -685,6 +691,8 @@ pub trait TryInto<T>: Sized {
 /// [`try_from`]: TryFrom::try_from
 #[rustc_diagnostic_item = "TryFrom"]
 #[stable(feature = "try_from", since = "1.34.0")]
+#[rustc_const_unstable(feature = "const_from", issue = "143773")]
+#[const_trait]
 pub trait TryFrom<T>: Sized {
     /// The type returned in the event of a conversion error.
     #[stable(feature = "try_from", since = "1.34.0")]
@@ -754,9 +762,10 @@ where
 
 // From implies Into
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T, U> Into<U> for T
+#[rustc_const_unstable(feature = "const_from", issue = "143773")]
+impl<T, U> const Into<U> for T
 where
-    U: From<T>,
+    U: ~const From<T>,
 {
     /// Calls `U::from(self)`.
     ///
@@ -771,7 +780,8 @@ where
 
 // From (and thus Into) is reflexive
 #[stable(feature = "rust1", since = "1.0.0")]
-impl<T> From<T> for T {
+#[rustc_const_unstable(feature = "const_from", issue = "143773")]
+impl<T> const From<T> for T {
     /// Returns the argument unchanged.
     #[inline(always)]
     fn from(t: T) -> T {
@@ -787,17 +797,19 @@ impl<T> From<T> for T {
 #[stable(feature = "convert_infallible", since = "1.34.0")]
 #[rustc_reservation_impl = "permitting this impl would forbid us from adding \
                             `impl<T> From<!> for T` later; see rust-lang/rust#64715 for details"]
-impl<T> From<!> for T {
+#[rustc_const_unstable(feature = "const_from", issue = "143773")]
+impl<T> const From<!> for T {
     fn from(t: !) -> T {
         t
     }
 }
 
 // TryFrom implies TryInto
 #[stable(feature = "try_from", since = "1.34.0")]
-impl<T, U> TryInto<U> for T
+#[rustc_const_unstable(feature = "const_from", issue = "143773")]
+impl<T, U> const TryInto<U> for T
 where
-    U: TryFrom<T>,
+    U: ~const TryFrom<T>,
 {
     type Error = U::Error;
 
@@ -810,9 +822,10 @@ where
 // Infallible conversions are semantically equivalent to fallible conversions
 // with an uninhabited error type.
 #[stable(feature = "try_from", since = "1.34.0")]
-impl<T, U> TryFrom<U> for T
+#[rustc_const_unstable(feature = "const_from", issue = "143773")]
+impl<T, U> const TryFrom<U> for T
 where
-    U: Into<T>,
+    U: ~const Into<T>,
 {
     type Error = Infallible;