Auto merge of #158498 - JonathanBrouwer:rollup-3xKakOD, r=JonathanBrouwer

Rollup of 6 pull requests

Successful merges:

 - #158194 (Adds RmetaLinkCache a per-link cache that uses path as the key of dec…)
 - #137858 (Add new `unused_footnote_definition` rustdoc lint)
 - #158163 (Fix too-short variance slice in `variances_of` cycle recovery)
 - #158233 (Allow the unstable attribute on foreign type)
 - #158470 (Upgrade `jsonsocck` and `jsondoclint` to edition 2024.)
 - #158488 (Upgrade `rustdoc-json-types` to 2024 edition.)

Author: bors

compiler/rustc_attr_parsing/src/attributes/stability.rs

@@ -40,6 +40,7 @@ const ALLOWED_TARGETS: AllowedTargets<'_> = AllowedTargets::AllowList(&[
     Allow(Target::Static),
     Allow(Target::ForeignFn),
     Allow(Target::ForeignStatic),
+    Allow(Target::ForeignTy),
     Allow(Target::ExternCrate),
 ]);
 

compiler/rustc_codegen_ssa/src/back/archive.rs

@@ -22,7 +22,7 @@ use rustc_target::spec::Arch;
 use tracing::trace;
 
 use super::metadata::{create_compressed_metadata_file, search_for_section};
-use super::rmeta_link;
+use super::rmeta_link::{self, RmetaLinkCache};
 use super::symbol_edit::{apply_edits, collect_internal_names};
 use crate::common;
 // Public for ArchiveBuilderBuilder::extract_bundled_libs
@@ -311,7 +311,7 @@ fn find_binutils_dlltool(sess: &Session) -> OsString {
 }
 
 pub enum AddArchiveKind<'a> {
-    Rlib(/*skip*/ &'a dyn Fn(&str, ArchiveEntryKind) -> bool),
+    Rlib(&'a mut RmetaLinkCache, /*skip*/ &'a dyn Fn(&str, ArchiveEntryKind) -> bool),
     Other,
 }
 
@@ -466,7 +466,11 @@ pub fn try_extract_macho_fat_archive(
 }
 
 impl<'a> ArchiveBuilder for ArArchiveBuilder<'a> {
-    fn add_archive(&mut self, archive_path: &Path, ar_kind: AddArchiveKind<'_>) -> io::Result<()> {
+    fn add_archive(
+        &mut self,
+        archive_path: &Path,
+        mut ar_kind: AddArchiveKind<'_>,
+    ) -> io::Result<()> {
         let mut archive_path = archive_path.to_path_buf();
         if self.sess.target.llvm_target.contains("-apple-macosx")
             && let Some(new_archive_path) = try_extract_macho_fat_archive(self.sess, &archive_path)?
@@ -481,8 +485,14 @@ impl<'a> ArchiveBuilder for ArArchiveBuilder<'a> {
         let archive_map = unsafe { Mmap::map(File::open(&archive_path)?)? };
         let archive = ArchiveFile::parse(&*archive_map)
             .map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
-        let metadata_link = match ar_kind {
-            AddArchiveKind::Rlib(..) => rmeta_link::read(&archive, &archive_map, &archive_path),
+        let skip = match &ar_kind {
+            AddArchiveKind::Rlib(_, skip) => Some(*skip),
+            AddArchiveKind::Other => None,
+        };
+        let metadata_link = match &mut ar_kind {
+            AddArchiveKind::Rlib(cache, _) => cache.get_or_insert_with(&archive_path, || {
+                rmeta_link::read(&archive, &archive_map, &archive_path)
+            }),
             AddArchiveKind::Other => None,
         };
         let archive_index = self.src_archives.len();
@@ -512,9 +522,9 @@ impl<'a> ArchiveBuilder for ArArchiveBuilder<'a> {
             } else {
                 ArchiveEntryKind::Other
             };
-            let drop = match ar_kind {
-                AddArchiveKind::Rlib(skip) => skip(&file_name, kind),
-                AddArchiveKind::Other => false,
+            let drop = match skip {
+                Some(skip) => skip(&file_name, kind),
+                None => false,
             };
             if !drop {
                 let source = if entry.is_thin() {

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -59,6 +59,7 @@ use super::archive::{
 use super::command::Command;
 use super::linker::{self, Linker};
 use super::metadata::{MetadataPosition, create_wrapper_file};
+use super::rmeta_link::RmetaLinkCache;
 use super::rpath::{self, RPathConfig};
 use super::{apple, rmeta_link, versioned_llvm_target};
 use crate::base::needs_allocator_shim_for_linking;
@@ -86,6 +87,7 @@ pub fn link_binary(
     let _timer = sess.timer("link_binary");
     let output_metadata = sess.opts.output_types.contains_key(&OutputType::Metadata);
     let mut tempfiles_for_stdout_output: Vec<PathBuf> = Vec::new();
+    let mut rmeta_link_cache = RmetaLinkCache::default();
     for &crate_type in &crate_info.crate_types {
         // Ignore executable crates if we have -Z no-codegen, as they will error.
         if (sess.opts.unstable_opts.no_codegen || !sess.opts.output_types.should_codegen())
@@ -139,6 +141,7 @@ pub fn link_binary(
                     link_staticlib(
                         sess,
                         archive_builder_builder,
+                        &mut rmeta_link_cache,
                         &compiled_modules,
                         &crate_info,
                         &metadata,
@@ -150,6 +153,7 @@ pub fn link_binary(
                     link_natively(
                         sess,
                         archive_builder_builder,
+                        &mut rmeta_link_cache,
                         crate_type,
                         &out_filename,
                         &compiled_modules,
@@ -502,6 +506,7 @@ fn link_rlib<'a>(
 fn link_staticlib(
     sess: &Session,
     archive_builder_builder: &dyn ArchiveBuilderBuilder,
+    rmeta_link_cache: &mut RmetaLinkCache,
     compiled_modules: &CompiledModules,
     crate_info: &CrateInfo,
     metadata: &EncodedMetadata,
@@ -531,7 +536,7 @@ fn link_staticlib(
         let bundled_libs: FxIndexSet<_> = native_libs.filter_map(|lib| lib.filename).collect();
         ab.add_archive(
             path,
-            AddArchiveKind::Rlib(&|fname: &str, entry_kind| {
+            AddArchiveKind::Rlib(rmeta_link_cache, &|fname: &str, entry_kind| {
                 // Ignore metadata and rmeta-link files.
                 if fname == METADATA_FILENAME || fname == rmeta_link::FILENAME {
                     return true;
@@ -939,6 +944,7 @@ fn report_linker_output(
 fn link_natively(
     sess: &Session,
     archive_builder_builder: &dyn ArchiveBuilderBuilder,
+    rmeta_link_cache: &mut RmetaLinkCache,
     crate_type: CrateType,
     out_filename: &Path,
     compiled_modules: &CompiledModules,
@@ -965,6 +971,7 @@ fn link_natively(
         flavor,
         sess,
         archive_builder_builder,
+        rmeta_link_cache,
         crate_type,
         tmpdir,
         temp_filename,
@@ -2562,6 +2569,7 @@ fn linker_with_args(
     flavor: LinkerFlavor,
     sess: &Session,
     archive_builder_builder: &dyn ArchiveBuilderBuilder,
+    rmeta_link_cache: &mut RmetaLinkCache,
     crate_type: CrateType,
     tmpdir: &Path,
     out_filename: &Path,
@@ -2690,6 +2698,7 @@ fn linker_with_args(
         cmd,
         sess,
         archive_builder_builder,
+        rmeta_link_cache,
         crate_info,
         crate_type,
         tmpdir,
@@ -3126,6 +3135,7 @@ fn add_upstream_rust_crates(
     cmd: &mut dyn Linker,
     sess: &Session,
     archive_builder_builder: &dyn ArchiveBuilderBuilder,
+    rmeta_link_cache: &mut RmetaLinkCache,
     crate_info: &CrateInfo,
     crate_type: CrateType,
     tmpdir: &Path,
@@ -3178,6 +3188,7 @@ fn add_upstream_rust_crates(
                         cmd,
                         sess,
                         archive_builder_builder,
+                        rmeta_link_cache,
                         crate_info,
                         tmpdir,
                         cnum,
@@ -3309,6 +3320,7 @@ fn add_static_crate(
     cmd: &mut dyn Linker,
     sess: &Session,
     archive_builder_builder: &dyn ArchiveBuilderBuilder,
+    rmeta_link_cache: &mut RmetaLinkCache,
     crate_info: &CrateInfo,
     tmpdir: &Path,
     cnum: CrateNum,
@@ -3339,7 +3351,7 @@ fn add_static_crate(
         let mut archive = archive_builder_builder.new_archive_builder(sess);
         if let Err(error) = archive.add_archive(
             cratepath,
-            AddArchiveKind::Rlib(&|f, entry_kind| {
+            AddArchiveKind::Rlib(rmeta_link_cache, &|f, entry_kind| {
                 if f == METADATA_FILENAME || f == rmeta_link::FILENAME {
                     return true;
                 }

compiler/rustc_codegen_ssa/src/back/rmeta_link.rs

@@ -2,9 +2,10 @@
 //! and potentially other data collected and used when building or linking a rlib.
 //! See <https://github.com/rust-lang/rust/issues/138243>.
 
-use std::path::Path;
+use std::path::{Path, PathBuf};
 
 use object::read::archive::ArchiveFile;
+use rustc_data_structures::fx::FxHashMap;
 use rustc_serialize::opaque::mem_encoder::MemEncoder;
 use rustc_serialize::opaque::{MAGIC_END_BYTES, MemDecoder};
 use rustc_serialize::{Decodable, Encodable};
@@ -54,3 +55,18 @@ pub fn read_from_data(archive_data: &[u8], rlib_path: &Path) -> Option<RmetaLink
     let archive = ArchiveFile::parse(archive_data).ok()?;
     read(&archive, archive_data, rlib_path)
 }
+
+#[derive(Default)]
+pub struct RmetaLinkCache {
+    cache: FxHashMap<PathBuf, Option<RmetaLink>>,
+}
+
+impl RmetaLinkCache {
+    pub fn get_or_insert_with(
+        &mut self,
+        rlib_path: &Path,
+        load: impl FnOnce() -> Option<RmetaLink>,
+    ) -> Option<&RmetaLink> {
+        self.cache.entry(rlib_path.to_path_buf()).or_insert_with(load).as_ref()
+    }
+}

compiler/rustc_query_impl/src/handle_cycle_error.rs

@@ -105,7 +105,7 @@ pub(crate) fn variances_of<'tcx>(
     err: Diag<'_>,
 ) -> &'tcx [ty::Variance] {
     let _guar = err.delay_as_bug();
-    let n = tcx.generics_of(def_id).own_params.len();
+    let n = tcx.generics_of(def_id).count();
     tcx.arena.alloc_from_iter(iter::repeat_n(ty::Bivariant, n))
 }
 

src/librustdoc/lint.rs

@@ -196,6 +196,20 @@ declare_rustdoc_lint! {
     "detects redundant explicit links in doc comments"
 }
 
+declare_rustdoc_lint! {
+    /// This lint checks for uses of footnote references without definition.
+    BROKEN_FOOTNOTE,
+    Warn,
+    "detects footnote references with no associated definition"
+}
+
+declare_rustdoc_lint! {
+    /// This lint checks if all footnote definitions are used.
+    UNUSED_FOOTNOTE_DEFINITION,
+    Warn,
+    "detects unused footnote definitions"
+}
+
 pub(crate) static RUSTDOC_LINTS: Lazy<Vec<&'static Lint>> = Lazy::new(|| {
     vec![
         BROKEN_INTRA_DOC_LINKS,
@@ -209,6 +223,8 @@ pub(crate) static RUSTDOC_LINTS: Lazy<Vec<&'static Lint>> = Lazy::new(|| {
         MISSING_CRATE_LEVEL_DOCS,
         UNESCAPED_BACKTICKS,
         REDUNDANT_EXPLICIT_LINKS,
+        BROKEN_FOOTNOTE,
+        UNUSED_FOOTNOTE_DEFINITION,
     ]
 });
 

src/librustdoc/passes/lint.rs

@@ -3,6 +3,7 @@
 
 mod bare_urls;
 mod check_code_block_syntax;
+mod footnotes;
 mod html_tags;
 mod redundant_explicit_links;
 mod unescaped_backticks;
@@ -41,6 +42,7 @@ impl DocVisitor<'_> for Linter<'_, '_> {
             if may_have_link {
                 bare_urls::visit_item(self.cx, item, hir_id, &dox);
                 redundant_explicit_links::visit_item(self.cx, item, hir_id);
+                footnotes::visit_item(self.cx, item, hir_id, &dox);
             }
             if may_have_code {
                 check_code_block_syntax::visit_item(self.cx, item, &dox);

src/librustdoc/passes/lint/footnotes.rs

@@ -0,0 +1,117 @@
+use std::ops::Range;
+
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_errors::DiagDecorator;
+use rustc_hir::HirId;
+use rustc_lint_defs::Applicability;
+use rustc_resolve::rustdoc::pulldown_cmark::{Event, Options, Parser, Tag};
+use rustc_resolve::rustdoc::source_span_for_markdown_range;
+
+use crate::clean::Item;
+use crate::core::DocContext;
+
+pub(crate) fn visit_item(cx: &DocContext<'_>, item: &Item, hir_id: HirId, dox: &str) {
+    let tcx = cx.tcx;
+
+    let mut missing_footnote_references = FxHashSet::default();
+    let mut footnote_references = FxHashSet::default();
+    let mut footnote_definitions = FxHashMap::default();
+
+    let options = Options::ENABLE_FOOTNOTES;
+    let mut parser = Parser::new_ext(dox, options).into_offset_iter().peekable();
+    while let Some((event, span)) = parser.next() {
+        match event {
+            Event::Text(text)
+                if &*text == "["
+                    && (span.start == 0 || dox.as_bytes().get(span.start - 1) != Some(&b'\\'))
+                    && let Some(len) = scan_footnote_ref(&dox[span.start..]) =>
+            {
+                missing_footnote_references
+                    .insert(Range { start: span.start, end: span.start + len });
+            }
+            Event::FootnoteReference(label) => {
+                footnote_references.insert(label);
+            }
+            Event::Start(Tag::FootnoteDefinition(label)) => {
+                footnote_definitions.insert(label, span.start + 1);
+            }
+            _ => {}
+        }
+    }
+
+    #[allow(rustc::potential_query_instability)]
+    for (footnote, span) in footnote_definitions {
+        if !footnote_references.contains(&footnote) {
+            let (span, _) = source_span_for_markdown_range(
+                tcx,
+                dox,
+                &(span..span + 1),
+                &item.attrs.doc_strings,
+            )
+            .unwrap_or_else(|| (item.attr_span(tcx), false));
+
+            tcx.emit_node_span_lint(
+                crate::lint::UNUSED_FOOTNOTE_DEFINITION,
+                hir_id,
+                span,
+                DiagDecorator(|lint| {
+                    lint.primary_message("unused footnote definition");
+                }),
+            );
+        }
+    }
+
+    #[allow(rustc::potential_query_instability)]
+    for span in missing_footnote_references {
+        let ref_span = source_span_for_markdown_range(tcx, dox, &span, &item.attrs.doc_strings)
+            .map(|(span, _)| span)
+            .unwrap_or_else(|| item.attr_span(tcx));
+
+        tcx.emit_node_span_lint(
+            crate::lint::BROKEN_FOOTNOTE,
+            hir_id,
+            ref_span,
+            DiagDecorator(|lint| {
+                lint.primary_message("no footnote definition matching this footnote");
+                lint.span_suggestion(
+                    ref_span.shrink_to_lo(),
+                    "if it should not be a footnote, escape it",
+                    "\\",
+                    Applicability::MaybeIncorrect,
+                );
+            }),
+        );
+    }
+}
+
+fn scan_footnote_ref(dox: &str) -> Option<usize> {
+    let dox = dox.as_bytes();
+    let mut i = 0;
+    if dox.get(i) != Some(&b'[') {
+        return None;
+    }
+    i += 1;
+    if dox.get(i) != Some(&b'^') {
+        return None;
+    }
+    i += 1;
+    while let Some(&c) = dox.get(i) {
+        if c == b']' {
+            i += 1;
+            return Some(i);
+        }
+        if c == b'\r' || c == b'\n' || c == b'[' {
+            // Can't nest things like this.
+            break;
+        }
+        if c == b'\\' {
+            i += 1;
+        }
+        if dox.get(i) == Some(&b'\r') || dox.get(i) == Some(&b'\n') {
+            // Can't have line breaks in footnote refs
+            break;
+        }
+        i += 1;
+    }
+    None
+}

src/rustdoc-json-types/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "rustdoc-json-types"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [lib]
 path = "lib.rs"