Auto merge of #75609 - tmandry:rollup-yrcmgke, r=tmandry

Rollup of 10 pull requests

Successful merges:

 - #74204 (Don't visit foreign function bodies when lowering ast to hir)
 - #74314 (rustc_typeck: construct {Closure,Generator}Substs more directly.)
 - #74346 (Use LocalDefId instead of HirId for reachable_set elements.)
 - #74399 (Move DelaySpanBugEmitted to ty::context)
 - #75177 (Add regression test for issue-66768)
 - #75223 (Add #[track_caller] to `Session::delay_span_bug`)
 - #75423 (Move to intra-doc links for /library/core/src/hint.rs)
 - #75485 (pin docs: add some forward references)
 - #75569 (Bump minor version of emsdk to 1.38.47)
 - #75596 (Switch to intra-doc links in /sys/windows/ext/{ffi,fs,process}.rs)

Failed merges:

r? @ghost

library/core/src/hint.rs

@@ -24,7 +24,6 @@ use crate::intrinsics;
 /// Otherwise, consider using the [`unreachable!`] macro, which does not allow
 /// optimizations but will panic when executed.
 ///
-/// [`unreachable!`]: ../macro.unreachable.html
 ///
 /// # Example
 ///
@@ -61,7 +60,7 @@ pub const unsafe fn unreachable_unchecked() -> ! {
 /// **Note**: On platforms that do not support receiving spin-loop hints this function does not
 /// do anything at all.
 ///
-/// [`core::sync::atomic::spin_loop_hint`]: ../sync/atomic/fn.spin_loop_hint.html
+/// [`core::sync::atomic::spin_loop_hint`]: crate::sync::atomic::spin_loop_hint
 #[inline]
 #[unstable(feature = "renamed_spin_loop", issue = "55002")]
 pub fn spin_loop() {

library/core/src/pin.rs

@@ -6,9 +6,12 @@
 //! as moving an object with pointers to itself will invalidate them, which could cause undefined
 //! behavior.
 //!
-//! A [`Pin<P>`] ensures that the pointee of any pointer type `P` has a stable location in memory,
-//! meaning it cannot be moved elsewhere and its memory cannot be deallocated
-//! until it gets dropped. We say that the pointee is "pinned".
+//! At a high level, a [`Pin<P>`] ensures that the pointee of any pointer type
+//! `P` has a stable location in memory, meaning it cannot be moved elsewhere
+//! and its memory cannot be deallocated until it gets dropped. We say that the
+//! pointee is "pinned". Things get more subtle when discussing types that
+//! combine pinned with non-pinned data; [see below](#projections-and-structural-pinning)
+//! for more details.
 //!
 //! By default, all types in Rust are movable. Rust allows passing all types by-value,
 //! and common smart-pointer types such as [`Box<T>`] and `&mut T` allow replacing and
@@ -61,6 +64,10 @@
 //!
 //! # Example: self-referential struct
 //!
+//! Before we go into more details to explain the guarantees and choices
+//! associated with `Pin<T>`, we discuss some examples for how it might be used.
+//! Feel free to [skip to where the theoretical discussion continues](#drop-guarantee).
+//!
 //! ```rust
 //! use std::pin::Pin;
 //! use std::marker::PhantomPinned;

library/std/src/sys/windows/ext/ffi.rs

@@ -30,13 +30,13 @@
 //! [`OsString`] is the Rust wrapper for owned strings in the
 //! preferred representation of the operating system. On Windows,
 //! this struct gets augmented with an implementation of the
-//! [`OsStringExt`] trait, which has a [`from_wide`] method. This
+//! [`OsStringExt`] trait, which has a [`OsStringExt::from_wide`] method. This
 //! lets you create an [`OsString`] from a `&[u16]` slice; presumably
 //! you get such a slice out of a `WCHAR` Windows API.
 //!
 //! Similarly, [`OsStr`] is the Rust wrapper for borrowed strings from
 //! preferred representation of the operating system. On Windows, the
-//! [`OsStrExt`] trait provides the [`encode_wide`] method, which
+//! [`OsStrExt`] trait provides the [`OsStrExt::encode_wide`] method, which
 //! outputs an [`EncodeWide`] iterator. You can [`collect`] this
 //! iterator, for example, to obtain a `Vec<u16>`; you can later get a
 //! pointer to this vector's contents and feed it to Windows APIs.
@@ -47,15 +47,8 @@
 //! ill-formed UTF-16.
 //!
 //! [ill-formed-utf-16]: https://simonsapin.github.io/wtf-8/#ill-formed-utf-16
-//! [`OsString`]: ../../../ffi/struct.OsString.html
-//! [`OsStr`]: ../../../ffi/struct.OsStr.html
-//! [`OsStringExt`]: trait.OsStringExt.html
-//! [`OsStrExt`]: trait.OsStrExt.html
-//! [`EncodeWide`]: struct.EncodeWide.html
-//! [`from_wide`]: trait.OsStringExt.html#tymethod.from_wide
-//! [`encode_wide`]: trait.OsStrExt.html#tymethod.encode_wide
-//! [`collect`]: ../../../iter/trait.Iterator.html#method.collect
-//! [U+FFFD]: ../../../char/constant.REPLACEMENT_CHARACTER.html
+//! [`collect`]: crate::iter::Iterator::collect
+//! [U+FFFD]: crate::char::REPLACEMENT_CHARACTER
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
@@ -68,14 +61,12 @@ use crate::sys_common::{AsInner, FromInner};
 pub use crate::sys_common::wtf8::EncodeWide;
 
 /// Windows-specific extensions to [`OsString`].
-///
-/// [`OsString`]: ../../../../std/ffi/struct.OsString.html
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait OsStringExt {
     /// Creates an `OsString` from a potentially ill-formed UTF-16 slice of
     /// 16-bit code units.
     ///
-    /// This is lossless: calling [`encode_wide`] on the resulting string
+    /// This is lossless: calling [`OsStrExt::encode_wide`] on the resulting string
     /// will always return the original code units.
     ///
     /// # Examples
@@ -89,8 +80,6 @@ pub trait OsStringExt {
     ///
     /// let string = OsString::from_wide(&source[..]);
     /// ```
-    ///
-    /// [`encode_wide`]: ./trait.OsStrExt.html#tymethod.encode_wide
     #[stable(feature = "rust1", since = "1.0.0")]
     fn from_wide(wide: &[u16]) -> Self;
 }
@@ -103,14 +92,12 @@ impl OsStringExt for OsString {
 }
 
 /// Windows-specific extensions to [`OsStr`].
-///
-/// [`OsStr`]: ../../../../std/ffi/struct.OsStr.html
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait OsStrExt {
     /// Re-encodes an `OsStr` as a wide character sequence, i.e., potentially
     /// ill-formed UTF-16.
     ///
-    /// This is lossless: calling [`OsString::from_wide`] and then
+    /// This is lossless: calling [`OsStringExt::from_wide`] and then
     /// `encode_wide` on the result will yield the original code units.
     /// Note that the encoding does not add a final null terminator.
     ///
@@ -128,8 +115,6 @@ pub trait OsStrExt {
     /// let result: Vec<u16> = string.encode_wide().collect();
     /// assert_eq!(&source[..], &result[..]);
     /// ```
-    ///
-    /// [`OsString::from_wide`]: ./trait.OsStringExt.html#tymethod.from_wide
     #[stable(feature = "rust1", since = "1.0.0")]
     fn encode_wide(&self) -> EncodeWide<'_>;
 }

library/std/src/sys/windows/ext/fs.rs

@@ -8,9 +8,7 @@ use crate::path::Path;
 use crate::sys;
 use crate::sys_common::{AsInner, AsInnerMut};
 
-/// Windows-specific extensions to [`File`].
-///
-/// [`File`]: ../../../fs/struct.File.html
+/// Windows-specific extensions to [`fs::File`].
 #[stable(feature = "file_offset", since = "1.15.0")]
 pub trait FileExt {
     /// Seeks to a given position and reads a number of bytes.
@@ -94,8 +92,6 @@ impl FileExt for fs::File {
 }
 
 /// Windows-specific extensions to [`fs::OpenOptions`].
-///
-/// [`fs::OpenOptions`]: ../../../../std/fs/struct.OpenOptions.html
 #[stable(feature = "open_options_ext", since = "1.10.0")]
 pub trait OpenOptionsExt {
     /// Overrides the `dwDesiredAccess` argument to the call to [`CreateFile`]
@@ -295,7 +291,6 @@ impl OpenOptionsExt for OpenOptions {
 /// The data members that this trait exposes correspond to the members
 /// of the [`BY_HANDLE_FILE_INFORMATION`] structure.
 ///
-/// [`fs::Metadata`]: ../../../../std/fs/struct.Metadata.html
 /// [`BY_HANDLE_FILE_INFORMATION`]:
 ///     https://docs.microsoft.com/en-us/windows/win32/api/fileapi/ns-fileapi-by_handle_file_information
 #[stable(feature = "metadata_ext", since = "1.1.0")]
@@ -499,11 +494,9 @@ impl MetadataExt for Metadata {
     }
 }
 
-/// Windows-specific extensions to [`FileType`].
+/// Windows-specific extensions to [`fs::FileType`].
 ///
 /// On Windows, a symbolic link knows whether it is a file or directory.
-///
-/// [`FileType`]: ../../../../std/fs/struct.FileType.html
 #[unstable(feature = "windows_file_type_ext", issue = "none")]
 pub trait FileTypeExt {
     /// Returns `true` if this file type is a symbolic link that is also a directory.

library/std/src/sys/windows/ext/process.rs

@@ -73,8 +73,6 @@ impl IntoRawHandle for process::ChildStderr {
 }
 
 /// Windows-specific extensions to [`process::ExitStatus`].
-///
-/// [`process::ExitStatus`]: ../../../../std/process/struct.ExitStatus.html
 #[stable(feature = "exit_status_from", since = "1.12.0")]
 pub trait ExitStatusExt {
     /// Creates a new `ExitStatus` from the raw underlying `u32` return value of
@@ -91,8 +89,6 @@ impl ExitStatusExt for process::ExitStatus {
 }
 
 /// Windows-specific extensions to the [`process::Command`] builder.
-///
-/// [`process::Command`]: ../../../../std/process/struct.Command.html
 #[stable(feature = "windows_process_extensions", since = "1.16.0")]
 pub trait CommandExt {
     /// Sets the [process creation flags][1] to be passed to `CreateProcess`.

src/ci/docker/scripts/emscripten.sh

@@ -19,5 +19,5 @@ exit 1
 
 git clone https://github.com/emscripten-core/emsdk.git /emsdk-portable
 cd /emsdk-portable
-hide_output ./emsdk install 1.38.46-upstream
-./emsdk activate 1.38.46-upstream
+hide_output ./emsdk install 1.38.47-upstream
+./emsdk activate 1.38.47-upstream

src/librustc_ast_lowering/item.rs

@@ -5,7 +5,7 @@ use crate::Arena;
 use rustc_ast::ast::*;
 use rustc_ast::node_id::NodeMap;
 use rustc_ast::ptr::P;
-use rustc_ast::visit::{self, AssocCtxt, Visitor};
+use rustc_ast::visit::{self, AssocCtxt, FnCtxt, FnKind, Visitor};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::struct_span_err;
 use rustc_hir as hir;
@@ -75,6 +75,18 @@ impl<'a> Visitor<'a> for ItemLowerer<'a, '_, '_> {
         }
     }
 
+    fn visit_fn(&mut self, fk: FnKind<'a>, sp: Span, _: NodeId) {
+        match fk {
+            FnKind::Fn(FnCtxt::Foreign, _, sig, _, _) => {
+                self.visit_fn_header(&sig.header);
+                visit::walk_fn_decl(self, &sig.decl);
+                // Don't visit the foreign function body even if it has one, since lowering the
+                // body would have no meaning and will have already been caught as a parse error.
+            }
+            _ => visit::walk_fn(self, fk, sp),
+        }
+    }
+
     fn visit_assoc_item(&mut self, item: &'a AssocItem, ctxt: AssocCtxt) {
         self.lctx.with_hir_id_owner(item.id, |lctx| match ctxt {
             AssocCtxt::Trait => {

src/librustc_codegen_ssa/back/symbol_export.rs

@@ -61,7 +61,7 @@ fn reachable_non_generics_provider(tcx: TyCtxt<'_>, cnum: CrateNum) -> DefIdMap<
     let mut reachable_non_generics: DefIdMap<_> = tcx
         .reachable_set(LOCAL_CRATE)
         .iter()
-        .filter_map(|&hir_id| {
+        .filter_map(|&def_id| {
             // We want to ignore some FFI functions that are not exposed from
             // this crate. Reachable FFI functions can be lumped into two
             // categories:
@@ -75,9 +75,8 @@ fn reachable_non_generics_provider(tcx: TyCtxt<'_>, cnum: CrateNum) -> DefIdMap<
             //
             // As a result, if this id is an FFI item (foreign item) then we only
             // let it through if it's included statically.
-            match tcx.hir().get(hir_id) {
+            match tcx.hir().get(tcx.hir().local_def_id_to_hir_id(def_id)) {
                 Node::ForeignItem(..) => {
-                    let def_id = tcx.hir().local_def_id(hir_id);
                     tcx.is_statically_included_foreign_item(def_id).then_some(def_id)
                 }
 
@@ -87,7 +86,6 @@ fn reachable_non_generics_provider(tcx: TyCtxt<'_>, cnum: CrateNum) -> DefIdMap<
                     ..
                 })
                 | Node::ImplItem(&hir::ImplItem { kind: hir::ImplItemKind::Fn(..), .. }) => {
-                    let def_id = tcx.hir().local_def_id(hir_id);
                     let generics = tcx.generics_of(def_id);
                     if !generics.requires_monomorphization(tcx)
                         // Functions marked with #[inline] are codegened with "internal"
@@ -361,7 +359,7 @@ fn upstream_drop_glue_for_provider<'tcx>(
 
 fn is_unreachable_local_definition_provider(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
     if let Some(def_id) = def_id.as_local() {
-        !tcx.reachable_set(LOCAL_CRATE).contains(&tcx.hir().local_def_id_to_hir_id(def_id))
+        !tcx.reachable_set(LOCAL_CRATE).contains(&def_id)
     } else {
         bug!("is_unreachable_local_definition called with non-local DefId: {:?}", def_id)
     }

src/librustc_middle/query/mod.rs

@@ -740,7 +740,8 @@ rustc_queries! {
     }
 
     Other {
-        query reachable_set(_: CrateNum) -> &'tcx HirIdSet {
+        query reachable_set(_: CrateNum) -> FxHashSet<LocalDefId> {
+            storage(ArenaCacheSelector<'tcx>)
             desc { "reachability" }
         }
 

src/librustc_middle/ty/consts/kind.rs

@@ -34,7 +34,7 @@ pub enum ConstKind<'tcx> {
 
     /// A placeholder for a const which could not be computed; this is
     /// propagated to avoid useless error messages.
-    Error(ty::sty::DelaySpanBugEmitted),
+    Error(ty::DelaySpanBugEmitted),
 }
 
 #[cfg(target_arch = "x86_64")]

src/librustc_middle/ty/context.rs

@@ -65,6 +65,12 @@ use std::mem;
 use std::ops::{Bound, Deref};
 use std::sync::Arc;
 
+/// A type that is not publicly constructable. This prevents people from making `TyKind::Error`
+/// except through `tcx.err*()`, which are in this module.
+#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
+#[derive(TyEncodable, TyDecodable, HashStable)]
+pub struct DelaySpanBugEmitted(());
+
 type InternedSet<'tcx, T> = ShardedHashMap<Interned<'tcx, T>, ()>;
 
 pub struct CtxtInterners<'tcx> {
@@ -1171,18 +1177,15 @@ impl<'tcx> TyCtxt<'tcx> {
     #[track_caller]
     pub fn ty_error_with_message<S: Into<MultiSpan>>(self, span: S, msg: &str) -> Ty<'tcx> {
         self.sess.delay_span_bug(span, msg);
-        self.mk_ty(Error(super::sty::DelaySpanBugEmitted(())))
+        self.mk_ty(Error(DelaySpanBugEmitted(())))
     }
 
     /// Like `err` but for constants.
     #[track_caller]
     pub fn const_error(self, ty: Ty<'tcx>) -> &'tcx Const<'tcx> {
         self.sess
             .delay_span_bug(DUMMY_SP, "ty::ConstKind::Error constructed but no error reported.");
-        self.mk_const(ty::Const {
-            val: ty::ConstKind::Error(super::sty::DelaySpanBugEmitted(())),
-            ty,
-        })
+        self.mk_const(ty::Const { val: ty::ConstKind::Error(DelaySpanBugEmitted(())), ty })
     }
 
     pub fn consider_optimizing<T: Fn() -> String>(&self, msg: T) -> bool {

src/librustc_middle/ty/mod.rs

@@ -60,6 +60,7 @@ pub use self::sty::{Binder, BoundTy, BoundTyKind, BoundVar, DebruijnIndex, INNER
 pub use self::sty::{BoundRegion, EarlyBoundRegion, FreeRegion, Region};
 pub use self::sty::{CanonicalPolyFnSig, FnSig, GenSig, PolyFnSig, PolyGenSig};
 pub use self::sty::{ClosureSubsts, GeneratorSubsts, TypeAndMut, UpvarSubsts};
+pub use self::sty::{ClosureSubstsParts, GeneratorSubstsParts};
 pub use self::sty::{ConstVid, FloatVid, IntVid, RegionVid, TyVid};
 pub use self::sty::{ExistentialPredicate, InferTy, ParamConst, ParamTy, ProjectionTy};
 pub use self::sty::{ExistentialProjection, PolyExistentialProjection};
@@ -72,8 +73,8 @@ pub use self::binding::BindingMode::*;
 
 pub use self::context::{tls, FreeRegionInfo, TyCtxt};
 pub use self::context::{
-    CanonicalUserType, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, ResolvedOpaqueTy,
-    UserType, UserTypeAnnotationIndex,
+    CanonicalUserType, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations,
+    DelaySpanBugEmitted, ResolvedOpaqueTy, UserType, UserTypeAnnotationIndex,
 };
 pub use self::context::{
     CtxtInterners, GeneratorInteriorTypeCause, GlobalCtxt, Lift, TypeckResults,

src/librustc_middle/ty/query/mod.rs

@@ -43,7 +43,7 @@ use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId};
 use rustc_hir::lang_items::{LangItem, LanguageItems};
-use rustc_hir::{Crate, HirIdSet, ItemLocalId, TraitCandidate};
+use rustc_hir::{Crate, ItemLocalId, TraitCandidate};
 use rustc_index::{bit_set::FiniteBitSet, vec::IndexVec};
 use rustc_session::config::{EntryFnType, OptLevel, OutputFilenames, SymbolManglingVersion};
 use rustc_session::utils::NativeLibKind;