Merge branch 'master' into search-core

rust-lang · Jun 10, 2024 · 5e52943 · 5e52943
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diff --git a/Cargo.lock b/Cargo.lock
diff --git a/RELEASES.md b/RELEASES.md
@@ -1,3 +1,131 @@
+Version 1.79.0 (2024-06-13)
+==========================
+
+<a id="1.79.0-Language"></a>
+
+Language
+--------
+- [Stabilize inline `const {}` expressions.](https://github.com/rust-lang/rust/pull/104087/)
+- [Prevent opaque types being instantiated twice with different regions within the same function.](https://github.com/rust-lang/rust/pull/116935/)
+- [Stabilize WebAssembly target features that are in phase 4 and 5.](https://github.com/rust-lang/rust/pull/117457/)
+- [Add the `redundant_lifetimes` lint to detect lifetimes which are semantically redundant.](https://github.com/rust-lang/rust/pull/118391/)
+- [Stabilize the `unnameable_types` lint for public types that can't be named.](https://github.com/rust-lang/rust/pull/120144/)
+- [Enable debuginfo in macros, and stabilize `-C collapse-macro-debuginfo` and `#[collapse_debuginfo]`.](https://github.com/rust-lang/rust/pull/120845/)
+- [Propagate temporary lifetime extension into `if` and `match` expressions.](https://github.com/rust-lang/rust/pull/121346/)
+- [Restrict promotion of `const fn` calls.](https://github.com/rust-lang/rust/pull/121557/)
+- [Warn against refining impls of crate-private traits with `refining_impl_trait` lint.](https://github.com/rust-lang/rust/pull/121720/)
+- [Stabilize associated type bounds (RFC 2289).](https://github.com/rust-lang/rust/pull/122055/)
+- [Stabilize importing `main` from other modules or crates.](https://github.com/rust-lang/rust/pull/122060/)
+- [Check return types of function types for well-formedness](https://github.com/rust-lang/rust/pull/115538)
+- [Rework `impl Trait` lifetime inference](https://github.com/rust-lang/rust/pull/116891/)
+- [Change inductive trait solver cycles to be ambiguous](https://github.com/rust-lang/rust/pull/122791)
+
+<a id="1.79.0-Compiler"></a>
+
+Compiler
+--------
+- [Define `-C strip` to only affect binaries, not artifacts like `.pdb`.](https://github.com/rust-lang/rust/pull/115120/)
+- [Stabilize `-Crelro-level` for controlling runtime link hardening.](https://github.com/rust-lang/rust/pull/121694/)
+- [Stabilize checking of `cfg` names and values at compile-time with `--check-cfg`.](https://github.com/rust-lang/rust/pull/123501/)
+  *Note that this only stabilizes the compiler part, the Cargo part is still unstable in this release.*
+- [Add `aarch64-apple-visionos` and `aarch64-apple-visionos-sim` tier 3 targets.](https://github.com/rust-lang/rust/pull/121419/)
+- [Add `riscv32ima-unknown-none-elf` tier 3 target.](https://github.com/rust-lang/rust/pull/122696/)
+- [Promote several Windows targets to tier 2](https://github.com/rust-lang/rust/pull/121712): `aarch64-pc-windows-gnullvm`, `i686-pc-windows-gnullvm`, and `x86_64-pc-windows-gnullvm`.
+
+Refer to Rust's [platform support page][platform-support-doc]
+for more information on Rust's tiered platform support.
+
+<a id="1.79.0-Libraries"></a>
+
+Libraries
+---------
+
+- [Implement `FromIterator` for `(impl Default + Extend, impl Default + Extend)`.](https://github.com/rust-lang/rust/pull/107462/)
+- [Implement `{Div,Rem}Assign<NonZero<X>>` on `X`.](https://github.com/rust-lang/rust/pull/121952/)
+- [Document overrides of `clone_from()` in core/std.](https://github.com/rust-lang/rust/pull/122201/)
+- [Link MSVC default lib in core.](https://github.com/rust-lang/rust/pull/122268/)
+- [Caution against using `transmute` between pointers and integers.](https://github.com/rust-lang/rust/pull/122379/)
+- [Enable frame pointers for the standard library.](https://github.com/rust-lang/rust/pull/122646/)
+
+<a id="1.79.0-Stabilized-APIs"></a>
+
+Stabilized APIs
+---------------
+
+- [`{integer}::unchecked_add`](https://doc.rust-lang.org/stable/core/primitive.i32.html#method.unchecked_add)
+- [`{integer}::unchecked_mul`](https://doc.rust-lang.org/stable/core/primitive.i32.html#method.unchecked_mul)
+- [`{integer}::unchecked_sub`](https://doc.rust-lang.org/stable/core/primitive.i32.html#method.unchecked_sub)
+- [`<[T]>::split_at_unchecked`](https://doc.rust-lang.org/stable/core/primitive.slice.html#method.split_at_unchecked)
+- [`<[T]>::split_at_mut_unchecked`](https://doc.rust-lang.org/stable/core/primitive.slice.html#method.split_at_mut_unchecked)
+- [`<[u8]>::utf8_chunks`](https://doc.rust-lang.org/stable/core/primitive.slice.html#method.utf8_chunks)
+- [`str::Utf8Chunks`](https://doc.rust-lang.org/stable/core/str/struct.Utf8Chunks.html)
+- [`str::Utf8Chunk`](https://doc.rust-lang.org/stable/core/str/struct.Utf8Chunk.html)
+- [`<*const T>::is_aligned`](https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.is_aligned)
+- [`<*mut T>::is_aligned`](https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.is_aligned-1)
+- [`NonNull::is_aligned`](https://doc.rust-lang.org/stable/core/ptr/struct.NonNull.html#method.is_aligned)
+- [`<*const [T]>::len`](https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.len)
+- [`<*mut [T]>::len`](https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.len-1)
+- [`<*const [T]>::is_empty`](https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.is_empty)
+- [`<*mut [T]>::is_empty`](https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.is_empty-1)
+- [`NonNull::<[T]>::is_empty`](https://doc.rust-lang.org/stable/core/ptr/struct.NonNull.html#method.is_empty)
+- [`CStr::count_bytes`](https://doc.rust-lang.org/stable/core/ffi/c_str/struct.CStr.html#method.count_bytes)
+- [`io::Error::downcast`](https://doc.rust-lang.org/stable/std/io/struct.Error.html#method.downcast)
+- [`num::NonZero<T>`](https://doc.rust-lang.org/stable/core/num/struct.NonZero.html)
+- [`path::absolute`](https://doc.rust-lang.org/stable/std/path/fn.absolute.html)
+- [`proc_macro::Literal::byte_character`](https://doc.rust-lang.org/stable/proc_macro/struct.Literal.html#method.byte_character)
+- [`proc_macro::Literal::c_string`](https://doc.rust-lang.org/stable/proc_macro/struct.Literal.html#method.c_string)
+
+These APIs are now stable in const contexts:
+
+- [`Atomic*::into_inner`](https://doc.rust-lang.org/stable/core/sync/atomic/struct.AtomicUsize.html#method.into_inner)
+- [`io::Cursor::new`](https://doc.rust-lang.org/stable/std/io/struct.Cursor.html#method.new)
+- [`io::Cursor::get_ref`](https://doc.rust-lang.org/stable/std/io/struct.Cursor.html#method.get_ref)
+- [`io::Cursor::position`](https://doc.rust-lang.org/stable/std/io/struct.Cursor.html#method.position)
+- [`io::empty`](https://doc.rust-lang.org/stable/std/io/fn.empty.html)
+- [`io::repeat`](https://doc.rust-lang.org/stable/std/io/fn.repeat.html)
+- [`io::sink`](https://doc.rust-lang.org/stable/std/io/fn.sink.html)
+- [`panic::Location::caller`](https://doc.rust-lang.org/stable/std/panic/struct.Location.html#method.caller)
+- [`panic::Location::file`](https://doc.rust-lang.org/stable/std/panic/struct.Location.html#method.file)
+- [`panic::Location::line`](https://doc.rust-lang.org/stable/std/panic/struct.Location.html#method.line)
+- [`panic::Location::column`](https://doc.rust-lang.org/stable/std/panic/struct.Location.html#method.column)
+
+<a id="1.79.0-Cargo"></a>
+
+Cargo
+-----
+
+- [Prevent dashes in `lib.name`, always normalizing to `_`.](https://github.com/rust-lang/cargo/pull/12783/)
+- [Stabilize MSRV-aware version requirement selection in `cargo add`.](https://github.com/rust-lang/cargo/pull/13608/)
+- [Switch to using `gitoxide` by default for listing files.](https://github.com/rust-lang/cargo/pull/13696/)
+- [Error on `[project]` in Edition 2024; `cargo fix --edition` will change it to `[package]`.](https://github.com/rust-lang/cargo/pull/13747/)
+
+<a id="1.79.0-Rustdoc"></a>
+
+Rustdoc
+-----
+
+- [Always display stability version even if it's the same as the containing item.](https://github.com/rust-lang/rust/pull/118441/)
+- [Show a single search result for items with multiple paths.](https://github.com/rust-lang/rust/pull/119912/)
+- [Support typing `/` in docs to begin a search.](https://github.com/rust-lang/rust/pull/123355/)
+
+<a id="1.79.0-Misc"></a>
+
+Misc
+----
+
+<a id="1.79.0-Compatibility-Notes"></a>
+
+Compatibility Notes
+-------------------
+
+- [Update the minimum external LLVM to 17.](https://github.com/rust-lang/rust/pull/122649/)
+- [`RustcEncodable` and `RustcDecodable` are soft-destabilized, to be removed
+  from the prelude in next edition.](https://github.com/rust-lang/rust/pull/116016/)
+- [The `wasm_c_abi` future-incompatibility lint will warn about use of the
+  non-spec-compliant C ABI.](https://github.com/rust-lang/rust/pull/117918/)
+  Use `wasm-bindgen v0.2.88` to generate forward-compatible bindings.
+- [Check return types of function types for well-formedness](https://github.com/rust-lang/rust/pull/115538)
+
 Version 1.78.0 (2024-05-02)
 ==========================
 

diff --git a/compiler/rustc_codegen_cranelift/src/base.rs b/compiler/rustc_codegen_cranelift/src/base.rs
@@ -832,9 +832,10 @@ fn codegen_stmt<'tcx>(
                     let val = match null_op {
                         NullOp::SizeOf => layout.size.bytes(),
                         NullOp::AlignOf => layout.align.abi.bytes(),
-                        NullOp::OffsetOf(fields) => {
-                            layout.offset_of_subfield(fx, fields.iter()).bytes()
-                        }
+                        NullOp::OffsetOf(fields) => fx
+                            .tcx
+                            .offset_of_subfield(ParamEnv::reveal_all(), layout, fields.iter())
+                            .bytes(),
                         NullOp::UbChecks => {
                             let val = fx.tcx.sess.ub_checks();
                             let val = CValue::by_val(

diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
@@ -1109,10 +1109,12 @@ fn generic_simd_intrinsic<'ll, 'tcx>(
         tcx.normalize_erasing_late_bound_regions(ty::ParamEnv::reveal_all(), callee_ty.fn_sig(tcx));
     let arg_tys = sig.inputs();
 
-    // Vectors must be immediates (non-power-of-2 #[repr(packed)] are not)
-    for (ty, arg) in arg_tys.iter().zip(args) {
-        if ty.is_simd() && !matches!(arg.val, OperandValue::Immediate(_)) {
-            return_error!(InvalidMonomorphization::SimdArgument { span, name, ty: *ty });
+    // Sanity-check: all vector arguments must be immediates.
+    if cfg!(debug_assertions) {
+        for (ty, arg) in arg_tys.iter().zip(args) {
+            if ty.is_simd() {
+                assert!(matches!(arg.val, OperandValue::Immediate(_)));
+            }
         }
     }
 

diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
@@ -680,7 +680,10 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         bx.cx().const_usize(val)
                     }
                     mir::NullOp::OffsetOf(fields) => {
-                        let val = layout.offset_of_subfield(bx.cx(), fields.iter()).bytes();
+                        let val = bx
+                            .tcx()
+                            .offset_of_subfield(bx.param_env(), layout, fields.iter())
+                            .bytes();
                         bx.cx().const_usize(val)
                     }
                     mir::NullOp::UbChecks => {

diff --git a/compiler/rustc_const_eval/src/interpret/step.rs b/compiler/rustc_const_eval/src/interpret/step.rs
@@ -253,7 +253,10 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                         Scalar::from_target_usize(val, self)
                     }
                     mir::NullOp::OffsetOf(fields) => {
-                        let val = layout.offset_of_subfield(self, fields.iter()).bytes();
+                        let val = self
+                            .tcx
+                            .offset_of_subfield(self.param_env, layout, fields.iter())
+                            .bytes();
                         Scalar::from_target_usize(val, self)
                     }
                     mir::NullOp::UbChecks => Scalar::from_bool(self.tcx.sess.ub_checks()),

diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
@@ -559,6 +559,8 @@ declare_features! (
     (unstable, offset_of_enum, "1.75.0", Some(120141)),
     /// Allows using multiple nested field accesses in offset_of!
     (unstable, offset_of_nested, "1.77.0", Some(120140)),
+    /// Allows using fields with slice type in offset_of!
+    (unstable, offset_of_slice, "CURRENT_RUSTC_VERSION", Some(126151)),
     /// Allows using `#[optimize(X)]`.
     (unstable, optimize_attribute, "1.34.0", Some(54882)),
     /// Allows postfix match `expr.match { ... }`

diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
@@ -3363,7 +3363,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                     let field_ty = self.field_ty(expr.span, field, args);
 
-                    // FIXME: DSTs with static alignment should be allowed
+                    // Enums are anyway always sized. But just to safeguard against future
+                    // language extensions, let's double-check.
                     self.require_type_is_sized(field_ty, expr.span, ObligationCauseCode::Misc);
 
                     if field.vis.is_accessible_from(sub_def_scope, self.tcx) {
@@ -3391,8 +3392,19 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     {
                         let field_ty = self.field_ty(expr.span, field, args);
 
-                        // FIXME: DSTs with static alignment should be allowed
-                        self.require_type_is_sized(field_ty, expr.span, ObligationCauseCode::Misc);
+                        if self.tcx.features().offset_of_slice {
+                            self.require_type_has_static_alignment(
+                                field_ty,
+                                expr.span,
+                                ObligationCauseCode::Misc,
+                            );
+                        } else {
+                            self.require_type_is_sized(
+                                field_ty,
+                                expr.span,
+                                ObligationCauseCode::Misc,
+                            );
+                        }
 
                         if field.vis.is_accessible_from(def_scope, self.tcx) {
                             self.tcx.check_stability(field.did, Some(expr.hir_id), expr.span, None);
@@ -3412,10 +3424,21 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     if let Ok(index) = field.as_str().parse::<usize>()
                         && field.name == sym::integer(index)
                     {
-                        for ty in tys.iter().take(index + 1) {
-                            self.require_type_is_sized(ty, expr.span, ObligationCauseCode::Misc);
-                        }
                         if let Some(&field_ty) = tys.get(index) {
+                            if self.tcx.features().offset_of_slice {
+                                self.require_type_has_static_alignment(
+                                    field_ty,
+                                    expr.span,
+                                    ObligationCauseCode::Misc,
+                                );
+                            } else {
+                                self.require_type_is_sized(
+                                    field_ty,
+                                    expr.span,
+                                    ObligationCauseCode::Misc,
+                                );
+                            }
+
                             field_indices.push((FIRST_VARIANT, index.into()));
                             current_container = field_ty;
 

diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -386,6 +386,26 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
+    pub fn require_type_has_static_alignment(
+        &self,
+        ty: Ty<'tcx>,
+        span: Span,
+        code: traits::ObligationCauseCode<'tcx>,
+    ) {
+        if !ty.references_error() {
+            let tail =
+                self.tcx.struct_tail_with_normalize(ty, |ty| self.normalize(span, ty), || {});
+            // Sized types have static alignment, and so do slices.
+            if tail.is_trivially_sized(self.tcx) || matches!(tail.kind(), ty::Slice(..)) {
+                // Nothing else is required here.
+            } else {
+                // We can't be sure, let's required full `Sized`.
+                let lang_item = self.tcx.require_lang_item(LangItem::Sized, None);
+                self.require_type_meets(ty, span, code, lang_item);
+            }
+        }
+    }
+
     pub fn register_bound(
         &self,
         ty: Ty<'tcx>,

diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
@@ -1351,3 +1351,37 @@ pub trait FnAbiOf<'tcx>: FnAbiOfHelpers<'tcx> {
 }
 
 impl<'tcx, C: FnAbiOfHelpers<'tcx>> FnAbiOf<'tcx> for C {}
+
+impl<'tcx> TyCtxt<'tcx> {
+    pub fn offset_of_subfield<I>(
+        self,
+        param_env: ty::ParamEnv<'tcx>,
+        mut layout: TyAndLayout<'tcx>,
+        indices: I,
+    ) -> Size
+    where
+        I: Iterator<Item = (VariantIdx, FieldIdx)>,
+    {
+        let cx = LayoutCx { tcx: self, param_env };
+        let mut offset = Size::ZERO;
+
+        for (variant, field) in indices {
+            layout = layout.for_variant(&cx, variant);
+            let index = field.index();
+            offset += layout.fields.offset(index);
+            layout = layout.field(&cx, index);
+            if !layout.is_sized() {
+                // If it is not sized, then the tail must still have at least a known static alignment.
+                let tail = self.struct_tail_erasing_lifetimes(layout.ty, param_env);
+                if !matches!(tail.kind(), ty::Slice(..)) {
+                    bug!(
+                        "offset of not-statically-aligned field (type {:?}) cannot be computed statically",
+                        layout.ty
+                    );
+                }
+            }
+        }
+
+        offset
+    }
+}
diff --git a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
@@ -10,7 +10,7 @@ use rustc_middle::bug;
 use rustc_middle::mir::interpret::{InterpResult, Scalar};
 use rustc_middle::mir::visit::{MutVisitor, PlaceContext, Visitor};
 use rustc_middle::mir::*;
-use rustc_middle::ty::layout::LayoutOf;
+use rustc_middle::ty::layout::{HasParamEnv, LayoutOf};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_mir_dataflow::value_analysis::{
     Map, PlaceIndex, State, TrackElem, ValueAnalysis, ValueAnalysisWrapper, ValueOrPlace,
@@ -285,9 +285,11 @@ impl<'tcx> ValueAnalysis<'tcx> for ConstAnalysis<'_, 'tcx> {
                 let val = match null_op {
                     NullOp::SizeOf if layout.is_sized() => layout.size.bytes(),
                     NullOp::AlignOf if layout.is_sized() => layout.align.abi.bytes(),
-                    NullOp::OffsetOf(fields) => {
-                        layout.offset_of_subfield(&self.ecx, fields.iter()).bytes()
-                    }
+                    NullOp::OffsetOf(fields) => self
+                        .ecx
+                        .tcx
+                        .offset_of_subfield(self.ecx.param_env(), layout, fields.iter())
+                        .bytes(),
                     _ => return ValueOrPlace::Value(FlatSet::Top),
                 };
                 FlatSet::Elem(Scalar::from_target_usize(val, &self.tcx))