Auto merge of #99892 - JohnTitor:rollup-qi4fem8, r=JohnTitor

Rollup of 8 pull requests

Successful merges:

 - #99686 (add suggestion when there is a impl of external trait on pointer with wrong coherence rules)
 - #99760 (doc/rustc: describe the uefi target platforms)
 - #99766 (Htmldocck: Substitute the doc channel when blessing)
 - #99781 (Use String::from_utf8_lossy in CStr demo)
 - #99803 (Update mentions to `rustc_metadata::rmeta::Lazy`)
 - #99845 (Remove `$` prefix for bash scripts in doc)
 - #99850 (rustdoc: Remove more Clean trait implementations)
 - #99872 (Clone the `src/llvm-project` submodule if profiling is enabled)

Failed merges:

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

compiler/rustc_metadata/src/rmeta/decoder.rs

@@ -83,7 +83,7 @@ pub(crate) struct CrateMetadata {
 
     // --- Some data pre-decoded from the metadata blob, usually for performance ---
     /// NOTE(eddyb) we pass `'static` to a `'tcx` parameter because this
-    /// lifetime is only used behind `Lazy`, and therefore acts like a
+    /// lifetime is only used behind `LazyValue`, `LazyArray`, or `LazyTable`, and therefore acts like a
     /// universal (`for<'tcx>`), that is paired up with whichever `TyCtxt`
     /// is being used to decode those values.
     root: CrateRoot,

compiler/rustc_metadata/src/rmeta/mod.rs

@@ -66,13 +66,13 @@ pub const METADATA_HEADER: &[u8] = &[b'r', b'u', b's', b't', 0, 0, 0, METADATA_V
 ///
 /// Metadata is effective a tree, encoded in post-order,
 /// and with the root's position written next to the header.
-/// That means every single `Lazy` points to some previous
+/// That means every single `LazyValue` points to some previous
 /// location in the metadata and is part of a larger node.
 ///
-/// The first `Lazy` in a node is encoded as the backwards
+/// The first `LazyValue` in a node is encoded as the backwards
 /// distance from the position where the containing node
-/// starts and where the `Lazy` points to, while the rest
-/// use the forward distance from the previous `Lazy`.
+/// starts and where the `LazyValue` points to, while the rest
+/// use the forward distance from the previous `LazyValue`.
 /// Distances start at 1, as 0-byte nodes are invalid.
 /// Also invalid are nodes being referred in a different
 /// order than they were encoded in.
@@ -94,12 +94,12 @@ impl<T> LazyValue<T> {
 
 /// A list of lazily-decoded values.
 ///
-/// Unlike `Lazy<Vec<T>>`, the length is encoded next to the
+/// Unlike `LazyValue<Vec<T>>`, the length is encoded next to the
 /// position, not at the position, which means that the length
 /// doesn't need to be known before encoding all the elements.
 ///
 /// If the length is 0, no position is encoded, but otherwise,
-/// the encoding is that of `Lazy`, with the distinction that
+/// the encoding is that of `LazyArray`, with the distinction that
 /// the minimal distance the length of the sequence, i.e.
 /// it's assumed there's no 0-byte element in the sequence.
 struct LazyArray<T> {
@@ -167,17 +167,17 @@ impl<I, T> Clone for LazyTable<I, T> {
     }
 }
 
-/// Encoding / decoding state for `Lazy`.
+/// Encoding / decoding state for `Lazy`s (`LazyValue`, `LazyArray`, and `LazyTable`).
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 enum LazyState {
     /// Outside of a metadata node.
     NoNode,
 
-    /// Inside a metadata node, and before any `Lazy`.
+    /// Inside a metadata node, and before any `Lazy`s.
     /// The position is that of the node itself.
     NodeStart(NonZeroUsize),
 
-    /// Inside a metadata node, with a previous `Lazy`.
+    /// Inside a metadata node, with a previous `Lazy`s.
     /// The position is where that previous `Lazy` would start.
     Previous(NonZeroUsize),
 }

compiler/rustc_metadata/src/rmeta/table.rs

@@ -141,7 +141,7 @@ fixed_size_enum! {
     }
 }
 
-// We directly encode `DefPathHash` because a `Lazy` would encur a 25% cost.
+// We directly encode `DefPathHash` because a `LazyValue` would incur a 25% cost.
 impl FixedSizeEncoding for Option<DefPathHash> {
     type ByteArray = [u8; 16];
 
@@ -159,7 +159,7 @@ impl FixedSizeEncoding for Option<DefPathHash> {
     }
 }
 
-// We directly encode RawDefId because using a `Lazy` would incur a 50% overhead in the worst case.
+// We directly encode RawDefId because using a `LazyValue` would incur a 50% overhead in the worst case.
 impl FixedSizeEncoding for Option<RawDefId> {
     type ByteArray = [u8; 8];
 

compiler/rustc_typeck/src/coherence/orphan.rs

@@ -3,7 +3,7 @@
 
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::struct_span_err;
-use rustc_errors::ErrorGuaranteed;
+use rustc_errors::{Diagnostic, ErrorGuaranteed};
 use rustc_hir as hir;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::ty::subst::GenericArgKind;
@@ -107,6 +107,7 @@ fn do_orphan_check_impl<'tcx>(
         Err(err) => emit_orphan_check_error(
             tcx,
             sp,
+            item.span,
             tr.path.span,
             trait_ref.self_ty(),
             impl_.self_ty.span,
@@ -207,6 +208,7 @@ fn do_orphan_check_impl<'tcx>(
 fn emit_orphan_check_error<'tcx>(
     tcx: TyCtxt<'tcx>,
     sp: Span,
+    full_impl_span: Span,
     trait_span: Span,
     self_ty: Ty<'tcx>,
     self_ty_span: Span,
@@ -247,8 +249,20 @@ fn emit_orphan_check_error<'tcx>(
                     ty::Slice(_) => (this, " because slices are always foreign"),
                     ty::Array(..) => (this, " because arrays are always foreign"),
                     ty::Tuple(..) => (this, " because tuples are always foreign"),
+                    ty::RawPtr(ptr_ty) => {
+                        emit_newtype_suggestion_for_raw_ptr(
+                            full_impl_span,
+                            self_ty,
+                            self_ty_span,
+                            ptr_ty,
+                            &mut err,
+                        );
+
+                        (format!("`{}`", ty), " because raw pointers are always foreign")
+                    }
                     _ => (format!("`{}`", ty), ""),
                 };
+
                 let msg = format!("{} is not defined in the current crate{}", ty, postfix);
                 if *is_target_ty {
                     // Point at `D<A>` in `impl<A, B> for C<B> in D<A>`
@@ -330,6 +344,27 @@ fn emit_orphan_check_error<'tcx>(
     })
 }
 
+fn emit_newtype_suggestion_for_raw_ptr(
+    full_impl_span: Span,
+    self_ty: Ty<'_>,
+    self_ty_span: Span,
+    ptr_ty: &ty::TypeAndMut<'_>,
+    diag: &mut Diagnostic,
+) {
+    if !self_ty.needs_subst() {
+        let mut_key = if ptr_ty.mutbl == rustc_middle::mir::Mutability::Mut { "mut " } else { "" };
+        let msg_sugg = "consider introducing a new wrapper type".to_owned();
+        let sugg = vec![
+            (
+                full_impl_span.shrink_to_lo(),
+                format!("struct WrapperType(*{}{});\n\n", mut_key, ptr_ty.ty),
+            ),
+            (self_ty_span, "WrapperType".to_owned()),
+        ];
+        diag.multipart_suggestion(msg_sugg, sugg, rustc_errors::Applicability::MaybeIncorrect);
+    }
+}
+
 /// Lint impls of auto traits if they are likely to have
 /// unsound or surprising effects on auto impls.
 fn lint_auto_trait_impl<'tcx>(

library/core/src/ffi/c_str.rs

@@ -65,9 +65,9 @@ use crate::str;
 /// extern "C" { fn my_string() -> *const c_char; }
 ///
 /// fn my_string_safe() -> String {
-///     unsafe {
-///         CStr::from_ptr(my_string()).to_string_lossy().into_owned()
-///     }
+///     let cstr = unsafe { CStr::from_ptr(my_string()) };
+///     // Get copy-on-write Cow<'_, str>, then guarantee a freshly-owned String allocation
+///     String::from_utf8_lossy(cstr.to_bytes()).to_string()
 /// }
 ///
 /// println!("string: {}", my_string_safe());

src/bootstrap/compile.rs

@@ -111,6 +111,11 @@ impl Step for Std {
 
         builder.update_submodule(&Path::new("library").join("stdarch"));
 
+        // Profiler information requires LLVM's compiler-rt
+        if builder.config.profiler {
+            builder.update_submodule(&Path::new("src/llvm-project"));
+        }
+
         let mut target_deps = builder.ensure(StartupObjects { compiler, target });
 
         let compiler_to_use = builder.compiler_for(compiler.stage, compiler.host, target);

src/doc/rustc/src/SUMMARY.md

@@ -28,6 +28,7 @@
     - [riscv32imac-unknown-xous-elf](platform-support/riscv32imac-unknown-xous-elf.md)
     - [*-pc-windows-gnullvm](platform-support/pc-windows-gnullvm.md)
     - [*-unknown-openbsd](platform-support/openbsd.md)
+    - [\*-unknown-uefi](platform-support/unknown-uefi.md)
     - [wasm64-unknown-unknown](platform-support/wasm64-unknown-unknown.md)
     - [x86_64-unknown-none](platform-support/x86_64-unknown-none.md)
 - [Targets](targets/index.md)