Rollup of 6 pull requests

compiler/rustc_middle/src/mir/mod.rs

@@ -494,6 +494,8 @@ impl<'tcx> Body<'tcx> {
 #[derive(Copy, Clone, PartialEq, Eq, Debug, TyEncodable, TyDecodable, HashStable)]
 pub enum Safety {
     Safe,
+    /// Unsafe because of compiler-generated unsafe code, like `await` desugaring
+    BuiltinUnsafe,
     /// Unsafe because of an unsafe fn
     FnUnsafe,
     /// Unsafe because of an `unsafe` block

compiler/rustc_middle/src/thir.rs

@@ -114,6 +114,7 @@ pub struct Adt<'tcx> {
 #[derive(Copy, Clone, Debug, HashStable)]
 pub enum BlockSafety {
     Safe,
+    BuiltinUnsafe,
     ExplicitUnsafe(hir::HirId),
 }
 

compiler/rustc_mir/src/transform/check_unsafety.rs

@@ -321,6 +321,7 @@ impl<'a, 'tcx> UnsafetyChecker<'a, 'tcx> {
                 }
                 false
             }
+            Safety::BuiltinUnsafe => true,
             Safety::ExplicitUnsafe(hir_id) => {
                 // mark unsafe block as used if there are any unsafe operations inside
                 if !violations.is_empty() {

compiler/rustc_mir_build/src/build/block.rs

@@ -214,6 +214,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         debug!("update_source_scope_for({:?}, {:?})", span, safety_mode);
         let new_unsafety = match safety_mode {
             BlockSafety::Safe => None,
+            BlockSafety::BuiltinUnsafe => Some(Safety::BuiltinUnsafe),
             BlockSafety::ExplicitUnsafe(hir_id) => {
                 match self.in_scope_unsafe {
                     Safety::Safe => {}

compiler/rustc_mir_build/src/check_unsafety.rs

@@ -29,11 +29,7 @@ struct UnsafetyVisitor<'a, 'tcx> {
 }
 
 impl<'tcx> UnsafetyVisitor<'_, 'tcx> {
-    fn in_safety_context<R>(
-        &mut self,
-        safety_context: SafetyContext,
-        f: impl FnOnce(&mut Self) -> R,
-    ) {
+    fn in_safety_context(&mut self, safety_context: SafetyContext, f: impl FnOnce(&mut Self)) {
         if let (
             SafetyContext::UnsafeBlock { span: enclosing_span, .. },
             SafetyContext::UnsafeBlock { span: block_span, hir_id, .. },
@@ -63,14 +59,14 @@ impl<'tcx> UnsafetyVisitor<'_, 'tcx> {
                 );
             }
             self.safety_context = prev_context;
-            return;
         }
     }
 
     fn requires_unsafe(&mut self, span: Span, kind: UnsafeOpKind) {
         let (description, note) = kind.description_and_note();
         let unsafe_op_in_unsafe_fn_allowed = self.unsafe_op_in_unsafe_fn_allowed();
         match self.safety_context {
+            SafetyContext::BuiltinUnsafeBlock => {}
             SafetyContext::UnsafeBlock { ref mut used, .. } => {
                 if !self.body_unsafety.is_unsafe() || !unsafe_op_in_unsafe_fn_allowed {
                     // Mark this block as useful
@@ -142,13 +138,23 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
     }
 
     fn visit_block(&mut self, block: &Block) {
-        if let BlockSafety::ExplicitUnsafe(hir_id) = block.safety_mode {
-            self.in_safety_context(
-                SafetyContext::UnsafeBlock { span: block.span, hir_id, used: false },
-                |this| visit::walk_block(this, block),
-            );
-        } else {
-            visit::walk_block(self, block);
+        match block.safety_mode {
+            // compiler-generated unsafe code should not count towards the usefulness of
+            // an outer unsafe block
+            BlockSafety::BuiltinUnsafe => {
+                self.in_safety_context(SafetyContext::BuiltinUnsafeBlock, |this| {
+                    visit::walk_block(this, block)
+                });
+            }
+            BlockSafety::ExplicitUnsafe(hir_id) => {
+                self.in_safety_context(
+                    SafetyContext::UnsafeBlock { span: block.span, hir_id, used: false },
+                    |this| visit::walk_block(this, block),
+                );
+            }
+            BlockSafety::Safe => {
+                visit::walk_block(self, block);
+            }
         }
     }
 
@@ -250,6 +256,7 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for UnsafetyVisitor<'a, 'tcx> {
 #[derive(Clone, Copy)]
 enum SafetyContext {
     Safe,
+    BuiltinUnsafeBlock,
     UnsafeFn,
     UnsafeBlock { span: Span, hir_id: hir::HirId, used: bool },
 }

compiler/rustc_mir_build/src/thir/cx/block.rs

@@ -26,7 +26,12 @@ impl<'tcx> Cx<'tcx> {
             expr: block.expr.map(|expr| self.mirror_expr(expr)),
             safety_mode: match block.rules {
                 hir::BlockCheckMode::DefaultBlock => BlockSafety::Safe,
-                hir::BlockCheckMode::UnsafeBlock(..) => BlockSafety::ExplicitUnsafe(block.hir_id),
+                hir::BlockCheckMode::UnsafeBlock(hir::UnsafeSource::CompilerGenerated) => {
+                    BlockSafety::BuiltinUnsafe
+                }
+                hir::BlockCheckMode::UnsafeBlock(hir::UnsafeSource::UserProvided) => {
+                    BlockSafety::ExplicitUnsafe(block.hir_id)
+                }
             },
         }
     }

src/librustdoc/clean/types.rs

@@ -523,6 +523,33 @@ impl Item {
             .collect()
     }
 
+    /// Find a list of all link names, without finding their href.
+    ///
+    /// This is used for generating summary text, which does not include
+    /// the link text, but does need to know which `[]`-bracketed names
+    /// are actually links.
+    crate fn link_names(&self, cache: &Cache) -> Vec<RenderedLink> {
+        cache
+            .intra_doc_links
+            .get(&self.def_id)
+            .map_or(&[][..], |v| v.as_slice())
+            .iter()
+            .filter_map(|ItemLink { link: s, link_text, did, fragment }| {
+                // FIXME(83083): using fragments as a side-channel for
+                // primitive names is very unfortunate
+                if did.is_some() || fragment.is_some() {
+                    Some(RenderedLink {
+                        original_text: s.clone(),
+                        new_text: link_text.clone(),
+                        href: String::new(),
+                    })
+                } else {
+                    None
+                }
+            })
+            .collect()
+    }
+
     crate fn is_crate(&self) -> bool {
         self.is_mod() && self.def_id.as_real().map_or(false, |did| did.index == CRATE_DEF_INDEX)
     }

src/librustdoc/doctest.rs

@@ -3,6 +3,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{ColorConfig, ErrorReported};
 use rustc_hir as hir;
+use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_hir::intravisit;
 use rustc_hir::{HirId, CRATE_HIR_ID};
 use rustc_interface::interface;
@@ -13,6 +14,7 @@ use rustc_session::{lint, DiagnosticOutput, Session};
 use rustc_span::edition::Edition;
 use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::sym;
+use rustc_span::Symbol;
 use rustc_span::{BytePos, FileName, Pos, Span, DUMMY_SP};
 use rustc_target::spec::TargetTriple;
 use tempfile::Builder as TempFileBuilder;
@@ -111,8 +113,6 @@ crate fn run(options: Options) -> Result<(), ErrorReported> {
     let res = interface::run_compiler(config, |compiler| {
         compiler.enter(|queries| {
             let _lower_to_hir = queries.lower_to_hir()?;
-
-            let crate_name = queries.crate_name()?.peek().to_string();
             let mut global_ctxt = queries.global_ctxt()?.take();
 
             let collector = global_ctxt.enter(|tcx| {
@@ -123,7 +123,7 @@ crate fn run(options: Options) -> Result<(), ErrorReported> {
                 opts.display_warnings |= options.display_warnings;
                 let enable_per_target_ignores = options.enable_per_target_ignores;
                 let mut collector = Collector::new(
-                    crate_name,
+                    tcx.crate_name(LOCAL_CRATE),
                     options,
                     false,
                     opts,
@@ -293,7 +293,7 @@ struct UnusedExterns {
 
 fn run_test(
     test: &str,
-    cratename: &str,
+    crate_name: &str,
     line: usize,
     options: Options,
     should_panic: bool,
@@ -312,7 +312,7 @@ fn run_test(
     report_unused_externs: impl Fn(UnusedExterns),
 ) -> Result<(), TestFailure> {
     let (test, line_offset, supports_color) =
-        make_test(test, Some(cratename), as_test_harness, opts, edition, Some(test_id));
+        make_test(test, Some(crate_name), as_test_harness, opts, edition, Some(test_id));
 
     let output_file = outdir.path().join("rust_out");
 
@@ -479,7 +479,7 @@ fn run_test(
 /// lines before the test code begins as well as if the output stream supports colors or not.
 crate fn make_test(
     s: &str,
-    cratename: Option<&str>,
+    crate_name: Option<&str>,
     dont_insert_main: bool,
     opts: &TestOptions,
     edition: Edition,
@@ -540,7 +540,7 @@ crate fn make_test(
             let sess = ParseSess::with_span_handler(handler, sm);
 
             let mut found_main = false;
-            let mut found_extern_crate = cratename.is_none();
+            let mut found_extern_crate = crate_name.is_none();
             let mut found_macro = false;
 
             let mut parser = match maybe_new_parser_from_source_str(&sess, filename, source) {
@@ -567,13 +567,13 @@ crate fn make_test(
 
                         if !found_extern_crate {
                             if let ast::ItemKind::ExternCrate(original) = item.kind {
-                                // This code will never be reached if `cratename` is none because
+                                // This code will never be reached if `crate_name` is none because
                                 // `found_extern_crate` is initialized to `true` if it is none.
-                                let cratename = cratename.unwrap();
+                                let crate_name = crate_name.unwrap();
 
                                 match original {
-                                    Some(name) => found_extern_crate = name.as_str() == cratename,
-                                    None => found_extern_crate = item.ident.as_str() == cratename,
+                                    Some(name) => found_extern_crate = name.as_str() == crate_name,
+                                    None => found_extern_crate = item.ident.as_str() == crate_name,
                                 }
                             }
                         }
@@ -631,14 +631,14 @@ crate fn make_test(
 
     // Don't inject `extern crate std` because it's already injected by the
     // compiler.
-    if !already_has_extern_crate && !opts.no_crate_inject && cratename != Some("std") {
-        if let Some(cratename) = cratename {
+    if !already_has_extern_crate && !opts.no_crate_inject && crate_name != Some("std") {
+        if let Some(crate_name) = crate_name {
             // Don't inject `extern crate` if the crate is never used.
             // NOTE: this is terribly inaccurate because it doesn't actually
             // parse the source, but only has false positives, not false
             // negatives.
-            if s.contains(cratename) {
-                prog.push_str(&format!("extern crate r#{};\n", cratename));
+            if s.contains(crate_name) {
+                prog.push_str(&format!("extern crate r#{};\n", crate_name));
                 line_offset += 1;
             }
         }
@@ -797,7 +797,7 @@ crate struct Collector {
     options: Options,
     use_headers: bool,
     enable_per_target_ignores: bool,
-    cratename: String,
+    crate_name: Symbol,
     opts: TestOptions,
     position: Span,
     source_map: Option<Lrc<SourceMap>>,
@@ -809,7 +809,7 @@ crate struct Collector {
 
 impl Collector {
     crate fn new(
-        cratename: String,
+        crate_name: Symbol,
         options: Options,
         use_headers: bool,
         opts: TestOptions,
@@ -823,7 +823,7 @@ impl Collector {
             options,
             use_headers,
             enable_per_target_ignores,
-            cratename,
+            crate_name,
             opts,
             position: DUMMY_SP,
             source_map,
@@ -871,7 +871,7 @@ impl Tester for Collector {
     fn add_test(&mut self, test: String, config: LangString, line: usize) {
         let filename = self.get_filename();
         let name = self.generate_name(line, &filename);
-        let cratename = self.cratename.to_string();
+        let crate_name = self.crate_name.to_string();
         let opts = self.opts.clone();
         let edition = config.edition.unwrap_or(self.options.edition);
         let options = self.options.clone();
@@ -954,7 +954,7 @@ impl Tester for Collector {
                 };
                 let res = run_test(
                     &test,
-                    &cratename,
+                    &crate_name,
                     line,
                     options,
                     config.should_panic,

src/librustdoc/formats/cache.rs

@@ -292,13 +292,14 @@ impl<'a, 'tcx> DocFolder for CacheBuilder<'a, 'tcx> {
                     // which should not be indexed. The crate-item itself is
                     // inserted later on when serializing the search-index.
                     if item.def_id.index().map_or(false, |idx| idx != CRATE_DEF_INDEX) {
+                        let desc = item.doc_value().map_or_else(String::new, |x| {
+                            short_markdown_summary(&x.as_str(), &item.link_names(&self.cache))
+                        });
                         self.cache.search_index.push(IndexItem {
                             ty: item.type_(),
                             name: s.to_string(),
                             path: path.join("::"),
-                            desc: item
-                                .doc_value()
-                                .map_or_else(String::new, |x| short_markdown_summary(&x.as_str())),
+                            desc,
                             parent,
                             parent_idx: None,
                             search_type: get_index_search_type(&item, &self.empty_cache, self.tcx),

src/librustdoc/html/markdown.rs

@@ -1051,7 +1051,11 @@ impl MarkdownSummaryLine<'_> {
 ///
 /// Returns a tuple of the rendered HTML string and whether the output was shortened
 /// due to the provided `length_limit`.
-fn markdown_summary_with_limit(md: &str, length_limit: usize) -> (String, bool) {
+fn markdown_summary_with_limit(
+    md: &str,
+    link_names: &[RenderedLink],
+    length_limit: usize,
+) -> (String, bool) {
     if md.is_empty() {
         return (String::new(), false);
     }
@@ -1065,7 +1069,20 @@ fn markdown_summary_with_limit(md: &str, length_limit: usize) -> (String, bool)
         *text_length += text.len();
     }
 
-    'outer: for event in Parser::new_ext(md, summary_opts()) {
+    let mut replacer = |broken_link: BrokenLink<'_>| {
+        if let Some(link) =
+            link_names.iter().find(|link| &*link.original_text == broken_link.reference)
+        {
+            Some((link.href.as_str().into(), link.new_text.as_str().into()))
+        } else {
+            None
+        }
+    };
+
+    let p = Parser::new_with_broken_link_callback(md, opts(), Some(&mut replacer));
+    let p = LinkReplacer::new(p, link_names);
+
+    'outer: for event in p {
         match &event {
             Event::Text(text) => {
                 for word in text.split_inclusive(char::is_whitespace) {
@@ -1121,8 +1138,8 @@ fn markdown_summary_with_limit(md: &str, length_limit: usize) -> (String, bool)
 /// Will shorten to 59 or 60 characters, including an ellipsis (…) if it was shortened.
 ///
 /// See [`markdown_summary_with_limit`] for details about what is rendered and what is not.
-crate fn short_markdown_summary(markdown: &str) -> String {
-    let (mut s, was_shortened) = markdown_summary_with_limit(markdown, 59);
+crate fn short_markdown_summary(markdown: &str, link_names: &[RenderedLink]) -> String {
+    let (mut s, was_shortened) = markdown_summary_with_limit(markdown, link_names, 59);
 
     if was_shortened {
         s.push('…');

src/librustdoc/html/markdown/tests.rs

@@ -221,7 +221,7 @@ fn test_header_ids_multiple_blocks() {
 #[test]
 fn test_short_markdown_summary() {
     fn t(input: &str, expect: &str) {
-        let output = short_markdown_summary(input);
+        let output = short_markdown_summary(input, &[][..]);
         assert_eq!(output, expect, "original: {}", input);
     }
 
@@ -232,6 +232,7 @@ fn test_short_markdown_summary() {
     t("Hard-break  \nsummary", "Hard-break summary");
     t("hello [Rust] :)\n\n[Rust]: https://www.rust-lang.org", "hello Rust :)");
     t("hello [Rust](https://www.rust-lang.org \"Rust\") :)", "hello Rust :)");
+    t("dud [link]", "dud [link]");
     t("code `let x = i32;` ...", "code <code>let x = i32;</code> …");
     t("type `Type<'static>` ...", "type <code>Type<'static></code> …");
     t("# top header", "top header");
@@ -259,6 +260,7 @@ fn test_plain_text_summary() {
     t("Hard-break  \nsummary", "Hard-break summary");
     t("hello [Rust] :)\n\n[Rust]: https://www.rust-lang.org", "hello Rust :)");
     t("hello [Rust](https://www.rust-lang.org \"Rust\") :)", "hello Rust :)");
+    t("dud [link]", "dud [link]");
     t("code `let x = i32;` ...", "code `let x = i32;` …");
     t("type `Type<'static>` ...", "type `Type<'static>` …");
     t("# top header", "top header");