Auto merge of #98440 - ehuss:update-beta-cargo, r=ehuss

[beta] Beta backports

* Remove the unused-#[doc(hidden)] logic from the unused_attributes lint #98336
* debuginfo: Fix NatVis for Rc and Arc with unsized pointees. #98137
* Revert "remove num_cpus dependency" in rustc and update cargo #97911
* Update LLVM submodule #97690
* Revert #96682. #97636
* don't do Sized and other return type checks on RPIT's real type #97431
* Temporarily disable submodule archive downloads. #98423

Author: bors

Cargo.lock

@@ -218,6 +218,7 @@ dependencies = [
  "getopts",
  "ignore",
  "libc",
+ "num_cpus",
  "once_cell",
  "opener",
  "pretty_assertions",
@@ -247,6 +248,7 @@ dependencies = [
  "anyhow",
  "flate2",
  "hex 0.4.2",
+ "num_cpus",
  "rayon",
  "serde",
  "serde_json",
@@ -346,6 +348,7 @@ dependencies = [
  "libgit2-sys",
  "log",
  "memchr",
+ "num_cpus",
  "opener",
  "openssl",
  "os_info",
@@ -4338,6 +4341,7 @@ name = "rustc_session"
 version = "0.0.0"
 dependencies = [
  "getopts",
+ "num_cpus",
  "rustc_ast",
  "rustc_data_structures",
  "rustc_errors",

compiler/rustc_ast/src/token.rs

@@ -50,12 +50,11 @@ pub enum Delimiter {
     Brace,
     /// `[ ... ]`
     Bracket,
-    /// `/*«*/ ... /*»*/`
+    /// `Ø ... Ø`
     /// An invisible delimiter, that may, for example, appear around tokens coming from a
     /// "macro variable" `$var`. It is important to preserve operator priorities in cases like
     /// `$var * 3` where `$var` is `1 + 2`.
-    /// Invisible delimiters are not directly writable in normal Rust code except as comments.
-    /// Therefore, they might not survive a roundtrip of a token stream through a string.
+    /// Invisible delimiters might not survive roundtrip of a token stream through a string.
     Invisible,
 }
 

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -590,28 +590,14 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
                     self.nbsp();
                 }
                 self.word("{");
-                let empty = tts.is_empty();
-                if !empty {
+                if !tts.is_empty() {
                     self.space();
                 }
                 self.ibox(0);
                 self.print_tts(tts, convert_dollar_crate);
                 self.end();
-                self.bclose(span, empty);
-            }
-            Some(Delimiter::Invisible) => {
-                self.word("/*«*/");
                 let empty = tts.is_empty();
-                if !empty {
-                    self.space();
-                }
-                self.ibox(0);
-                self.print_tts(tts, convert_dollar_crate);
-                self.end();
-                if !empty {
-                    self.space();
-                }
-                self.word("/*»*/");
+                self.bclose(span, empty);
             }
             Some(delim) => {
                 let token_str = self.token_kind_to_string(&token::OpenDelim(delim));
@@ -786,8 +772,9 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
             token::CloseDelim(Delimiter::Bracket) => "]".into(),
             token::OpenDelim(Delimiter::Brace) => "{".into(),
             token::CloseDelim(Delimiter::Brace) => "}".into(),
-            token::OpenDelim(Delimiter::Invisible) => "/*«*/".into(),
-            token::CloseDelim(Delimiter::Invisible) => "/*»*/".into(),
+            token::OpenDelim(Delimiter::Invisible) | token::CloseDelim(Delimiter::Invisible) => {
+                "".into()
+            }
             token::Pound => "#".into(),
             token::Dollar => "$".into(),
             token::Question => "?".into(),

compiler/rustc_passes/src/check_attr.rs

@@ -4,8 +4,7 @@
 //! conflicts between multiple such attributes attached to the same
 //! item.
 
-use rustc_ast::tokenstream::DelimSpan;
-use rustc_ast::{ast, AttrStyle, Attribute, Lit, LitKind, MacArgs, MetaItemKind, NestedMetaItem};
+use rustc_ast::{ast, AttrStyle, Attribute, Lit, LitKind, MetaItemKind, NestedMetaItem};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{pluralize, struct_span_err, Applicability, MultiSpan};
 use rustc_feature::{AttributeDuplicates, AttributeType, BuiltinAttribute, BUILTIN_ATTRIBUTE_MAP};
@@ -815,68 +814,6 @@ impl CheckAttrVisitor<'_> {
         }
     }
 
-    /// Checks `#[doc(hidden)]` attributes. Returns `true` if valid.
-    fn check_doc_hidden(
-        &self,
-        attr: &Attribute,
-        meta_index: usize,
-        meta: &NestedMetaItem,
-        hir_id: HirId,
-        target: Target,
-    ) -> bool {
-        if let Target::AssocConst
-        | Target::AssocTy
-        | Target::Method(MethodKind::Trait { body: true }) = target
-        {
-            let parent_hir_id = self.tcx.hir().get_parent_item(hir_id);
-            let containing_item = self.tcx.hir().expect_item(parent_hir_id);
-
-            if Target::from_item(containing_item) == Target::Impl {
-                let meta_items = attr.meta_item_list().unwrap();
-
-                let (span, replacement_span) = if meta_items.len() == 1 {
-                    (attr.span, attr.span)
-                } else {
-                    let meta_span = meta.span();
-                    (
-                        meta_span,
-                        meta_span.until(match meta_items.get(meta_index + 1) {
-                            Some(next_item) => next_item.span(),
-                            None => match attr.get_normal_item().args {
-                                MacArgs::Delimited(DelimSpan { close, .. }, ..) => close,
-                                _ => unreachable!(),
-                            },
-                        }),
-                    )
-                };
-
-                // FIXME: #[doc(hidden)] was previously erroneously allowed on trait impl items,
-                // so for backward compatibility only emit a warning and do not mark it as invalid.
-                self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, span, |lint| {
-                    lint.build("`#[doc(hidden)]` is ignored on trait impl items")
-                        .warn(
-                            "this was previously accepted by the compiler but is \
-                             being phased out; it will become a hard error in \
-                             a future release!",
-                        )
-                        .note(
-                            "whether the impl item is `doc(hidden)` or not \
-                             entirely depends on the corresponding trait item",
-                        )
-                        .span_suggestion(
-                            replacement_span,
-                            "remove this attribute",
-                            String::new(),
-                            Applicability::MachineApplicable,
-                        )
-                        .emit();
-                });
-            }
-        }
-
-        true
-    }
-
     /// Checks that an attribute is *not* used at the crate level. Returns `true` if valid.
     fn check_attr_not_crate_level(
         &self,
@@ -995,7 +932,7 @@ impl CheckAttrVisitor<'_> {
         let mut is_valid = true;
 
         if let Some(mi) = attr.meta() && let Some(list) = mi.meta_item_list() {
-            for (meta_index, meta) in list.into_iter().enumerate() {
+            for meta in list {
                 if let Some(i_meta) = meta.meta_item() {
                     match i_meta.name_or_empty() {
                         sym::alias
@@ -1036,15 +973,6 @@ impl CheckAttrVisitor<'_> {
                             is_valid = false;
                         }
 
-                        sym::hidden if !self.check_doc_hidden(attr,
-                            meta_index,
-                            meta,
-                            hir_id,
-                            target,
-                            ) => {
-                            is_valid = false;
-                        }
-
                         // no_default_passes: deprecated
                         // passes: deprecated
                         // plugins: removed, but rustdoc warns about it itself

compiler/rustc_session/Cargo.toml

@@ -15,5 +15,6 @@ rustc_serialize = { path = "../rustc_serialize" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_span = { path = "../rustc_span" }
 rustc_fs_util = { path = "../rustc_fs_util" }
+num_cpus = "1.0"
 rustc_ast = { path = "../rustc_ast" }
 rustc_lint_defs = { path = "../rustc_lint_defs" }

compiler/rustc_session/src/options.rs

@@ -578,7 +578,7 @@ mod parse {
     crate fn parse_threads(slot: &mut usize, v: Option<&str>) -> bool {
         match v.and_then(|s| s.parse().ok()) {
             Some(0) => {
-                *slot = std::thread::available_parallelism().map_or(1, std::num::NonZeroUsize::get);
+                *slot = ::num_cpus::get();
                 true
             }
             Some(i) => {

compiler/rustc_typeck/src/check/check.rs

@@ -103,12 +103,6 @@ pub(super) fn check_fn<'a, 'tcx>(
             DUMMY_SP,
             param_env,
         ));
-    // HACK(oli-obk): we rewrite the declared return type, too, so that we don't end up inferring all
-    // unconstrained RPIT to have `()` as their hidden type. This would happen because further down we
-    // compare the ret_coercion with declared_ret_ty, and anything uninferred would be inferred to the
-    // opaque type itself. That again would cause writeback to assume we have a recursive call site
-    // and do the sadly stabilized fallback to `()`.
-    let declared_ret_ty = ret_ty;
     fcx.ret_coercion = Some(RefCell::new(CoerceMany::new(ret_ty)));
     fcx.ret_type_span = Some(decl.output.span());
 
@@ -252,7 +246,12 @@ pub(super) fn check_fn<'a, 'tcx>(
             fcx.next_ty_var(TypeVariableOrigin { kind: TypeVariableOriginKind::DynReturnFn, span });
         debug!("actual_return_ty replaced with {:?}", actual_return_ty);
     }
-    fcx.demand_suptype(span, declared_ret_ty, actual_return_ty);
+
+    // HACK(oli-obk, compiler-errors): We should be comparing this against
+    // `declared_ret_ty`, but then anything uninferred would be inferred to
+    // the opaque type itself. That again would cause writeback to assume
+    // we have a recursive call site and do the sadly stabilized fallback to `()`.
+    fcx.demand_suptype(span, ret_ty, actual_return_ty);
 
     // Check that a function marked as `#[panic_handler]` has signature `fn(&PanicInfo) -> !`
     if let Some(panic_impl_did) = tcx.lang_items().panic_impl()

library/proc_macro/src/lib.rs

@@ -703,12 +703,11 @@ pub enum Delimiter {
     /// `[ ... ]`
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     Bracket,
-    /// `/*«*/ ... /*»*/`
+    /// `Ø ... Ø`
     /// An invisible delimiter, that may, for example, appear around tokens coming from a
     /// "macro variable" `$var`. It is important to preserve operator priorities in cases like
     /// `$var * 3` where `$var` is `1 + 2`.
-    /// Invisible delimiters are not directly writable in normal Rust code except as comments.
-    /// Therefore, they might not survive a roundtrip of a token stream through a string.
+    /// Invisible delimiters might not survive roundtrip of a token stream through a string.
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     None,
 }

src/bootstrap/Cargo.toml

@@ -37,6 +37,7 @@ test = false
 [dependencies]
 cmake = "0.1.38"
 filetime = "0.2"
+num_cpus = "1.0"
 getopts = "0.2.19"
 cc = "1.0.69"
 libc = "0.2"

src/bootstrap/config.rs

@@ -1345,7 +1345,7 @@ fn set<T>(field: &mut T, val: Option<T>) {
 
 fn threads_from_config(v: u32) -> u32 {
     match v {
-        0 => std::thread::available_parallelism().map_or(1, std::num::NonZeroUsize::get) as u32,
+        0 => num_cpus::get() as u32,
         n => n,
     }
 }