Rollup of 4 pull requests

compiler/rustc_expand/src/config.rs

@@ -7,10 +7,7 @@ use rustc_ast::token::{Delimiter, Token, TokenKind};
 use rustc_ast::tokenstream::{
     AttrTokenStream, AttrTokenTree, LazyAttrTokenStream, Spacing, TokenTree, WithTokens,
 };
-use rustc_ast::{
-    self as ast, AttrStyle, Attribute, HasAttrs, HasTokens, MetaItem, MetaItemInner, NodeId,
-    SyntheticAttr,
-};
+use rustc_ast::{self as ast, AttrStyle, Attribute, HasAttrs, HasTokens, NodeId, SyntheticAttr};
 use rustc_attr_ir::target::Target;
 use rustc_attr_ir::{self as attrs, AttributeKind};
 use rustc_attr_parsing::parser::AllowExprMetavar;
@@ -32,7 +29,7 @@ use tracing::instrument;
 
 use crate::diagnostics::{
     CrateNameInCfgAttr, CrateTypeInCfgAttr, FeatureNotAllowed, FeatureRemoved,
-    FeatureRemovedReason, InvalidCfg, RemoveExprNotSupported,
+    FeatureRemovedReason, RemoveExprNotSupported,
 };
 
 /// A folder that strips out items that do not belong in the current configuration.
@@ -442,32 +439,6 @@ impl<'a> StripUnconfigured<'a> {
     }
 }
 
-/// FIXME: Still used by Rustdoc, should be removed after
-pub fn parse_cfg_old<'a>(meta_item: &'a MetaItem, sess: &Session) -> Option<&'a MetaItemInner> {
-    let span = meta_item.span;
-    match meta_item.meta_item_list() {
-        None => {
-            sess.dcx().emit_err(InvalidCfg::NotFollowedByParens { span });
-            None
-        }
-        Some([]) => {
-            sess.dcx().emit_err(InvalidCfg::NoPredicate { span });
-            None
-        }
-        Some([_, .., l]) => {
-            sess.dcx().emit_err(InvalidCfg::MultiplePredicates { span: l.span() });
-            None
-        }
-        Some([single]) => match single.meta_item_or_bool() {
-            Some(meta_item) => Some(meta_item),
-            None => {
-                sess.dcx().emit_err(InvalidCfg::PredicateLiteral { span: single.span() });
-                None
-            }
-        },
-    }
-}
-
 fn is_cfg(attr: &Attribute) -> bool {
     attr.has_name(sym::cfg)
 }

compiler/rustc_expand/src/diagnostics.rs

@@ -189,40 +189,6 @@ pub(crate) struct RemoveExprNotSupported {
     pub span: Span,
 }
 
-#[derive(Diagnostic)]
-pub(crate) enum InvalidCfg {
-    #[diag("`cfg` is not followed by parentheses")]
-    NotFollowedByParens {
-        #[primary_span]
-        #[suggestion(
-            "expected syntax is",
-            code = "cfg(/* predicate */)",
-            applicability = "has-placeholders"
-        )]
-        span: Span,
-    },
-    #[diag("`cfg` predicate is not specified")]
-    NoPredicate {
-        #[primary_span]
-        #[suggestion(
-            "expected syntax is",
-            code = "cfg(/* predicate */)",
-            applicability = "has-placeholders"
-        )]
-        span: Span,
-    },
-    #[diag("multiple `cfg` predicates are specified")]
-    MultiplePredicates {
-        #[primary_span]
-        span: Span,
-    },
-    #[diag("`cfg` predicate key cannot be a literal")]
-    PredicateLiteral {
-        #[primary_span]
-        span: Span,
-    },
-}
-
 #[derive(Diagnostic)]
 #[diag("non-{$kind} macro in {$kind} position: {$name}")]
 pub(crate) struct WrongFragmentKind<'a> {

compiler/rustc_metadata/src/locator.rs

@@ -970,17 +970,19 @@ fn get_flavor_from_path(path: &Path) -> CrateFlavor {
     }
 }
 
-/// A function to fetch about all macros inside a proc-macro crate.
+/// A function to fetch all macros inside a proc-macro crate.
 ///
 /// Used by rust-analyzer-proc-macro-srv.
 pub fn get_proc_macros(
-    target: &Target,
     path: &Path,
     metadata_loader: &dyn MetadataLoader,
     cfg_version: &'static str,
 ) -> IoResult<Vec<(ProcMacroClient, ProcMacroKind)>> {
+    let host_tuple = TargetTuple::from_tuple(config::host_tuple());
+    let (host, _) = Target::search(&host_tuple, Path::new(""), false).unwrap();
+
     let metadata =
-        get_metadata_section(target, CrateFlavor::Dylib, path, metadata_loader, cfg_version, None)
+        get_metadata_section(&host, CrateFlavor::Dylib, path, metadata_loader, cfg_version, None)
             .map_err(|err| io::Error::other(err.to_string()))?;
     let stable_crate_id = metadata.get_root().stable_crate_id();
 

compiler/rustc_parse/src/parser/expr.rs

@@ -2777,6 +2777,17 @@ impl<'a> Parser<'a> {
                                 "you likely meant to continue parsing the let-chain starting here",
                             );
                         } else {
+                            if self.prev_token == token::Semi
+                                && (self.token == token::OpenBrace || AssocOp::from_token(&self.token).is_some())
+                            {
+                                err.span_suggestion_verbose(
+                                    self.prev_token.span,
+                                    "remove this semicolon",
+                                    "",
+                                    Applicability::MaybeIncorrect,
+                                );
+                            }
+
                             // Look for usages of '=>' where '>=' might be intended
                             if maybe_fatarrow == token::FatArrow {
                                 err.span_suggestion_verbose(

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 +1,152 @@
+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, TagEnd};
+use rustc_resolve::rustdoc::source_span_for_markdown_range;
+
+use crate::clean::Item;
+use crate::core::DocContext;
+
+// based on
+// https://github.com/pulldown-cmark/pulldown-cmark/blob/fc8fe713f58d7f4495038b48fe76c1f101fb3af1/pulldown-cmark/src/linklabel.rs#L65
+
+fn scan_ch(ch: u8, dox: &[u8], i: &mut usize) -> Option<()> {
+    if dox.get(*i) == Some(&ch) {
+        *i += 1;
+        Some(())
+    } else {
+        None
+    }
+}
+
+fn scan_footnote_ref(dox: &[u8], in_table: bool) -> Option<usize> {
+    let mut i = 0;
+    scan_ch(b'[', dox, &mut i)?;
+    scan_ch(b'^', dox, &mut i)?;
+    if dox.get(i) == Some(&b']') {
+        return None;
+    }
+    while let Some(&ch) = dox.get(i) {
+        if ch == b']'
+            || ch == b'['
+            || ch == b'\r'
+            || ch == b'\n'
+            || (in_table && ch == b'|')
+            // these two cause false negatives in obscure corner cases,
+            // but there's another warning from the unescaped_backticks
+            // and invalid_html_tags lints when they do
+            || ch == b'`'
+            || ch == b'<'
+        {
+            break;
+        } else if in_table
+            && ch == b'\\'
+            && dox.get(i + 1) == Some(&b'\\')
+            && dox.get(i + 2) == Some(&b'|')
+        {
+            i += 3;
+        } else if ch == b'\\' && dox.get(i + 1).copied().map_or(false, is_ascii_punctuation) {
+            i += 2;
+        } else {
+            i += 1;
+        }
+    }
+    scan_ch(b']', dox, &mut i)?;
+    Some(i)
+}
+
+fn is_ascii_punctuation(c: u8) -> bool {
+    c < 128 && (PUNCT_MASKS_ASCII[(c / 16) as usize] & (1 << (c & 15))) != 0
+}
+
+const PUNCT_MASKS_ASCII: [u16; 8] = [
+    0x0000, // U+0000...U+000F
+    0x0000, // U+0010...U+001F
+    0xfffe, // U+0020...U+002F
+    0xfc00, // U+0030...U+003F
+    0x0001, // U+0040...U+004F
+    0xf800, // U+0050...U+005F
+    0x0001, // U+0060...U+006F
+    0x7800, // U+0070...U+007F
+];
+
+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 mut in_table = false;
+
+    let options = Options::ENABLE_FOOTNOTES | Options::ENABLE_TABLES;
+    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.starts_with("[")
+                    && (span.start == 0 || dox.as_bytes()[span.start - 1] != b'\\')
+                    && let Some(len) =
+                        scan_footnote_ref(&dox.as_bytes()[span.start..], in_table) =>
+            {
+                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);
+            }
+            Event::Start(Tag::Table(_)) => in_table = true,
+            Event::End(TagEnd::Table) => in_table = false,
+            _ => {}
+        }
+    }
+
+    #[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",
+                    format!("\\{}", &dox[span]),
+                    Applicability::MaybeIncorrect,
+                );
+            }),
+        );
+    }
+}

src/tools/rust-analyzer/crates/proc-macro-srv/src/dylib.rs

@@ -5,9 +5,6 @@ mod proc_macros;
 use rustc_codegen_ssa::back::metadata::DefaultMetadataLoader;
 use rustc_interface::util::rustc_version_str;
 use rustc_proc_macro::bridge;
-use rustc_session::config::host_tuple;
-use rustc_target::spec::{Target, TargetTuple};
-use std::path::Path;
 use std::{fs, io, time::SystemTime};
 use temp_dir::TempDir;
 
@@ -78,11 +75,7 @@ struct ProcMacroLibrary {
 impl ProcMacroLibrary {
     fn open(path: &Utf8Path) -> io::Result<Self> {
         let proc_macros = rustc_span::create_default_session_globals_then(|| {
-            let (target, _) =
-                Target::search(&TargetTuple::from_tuple(host_tuple()), Path::new(""), false)
-                    .unwrap();
             rustc_metadata::locator::get_proc_macros(
-                &target,
                 path.as_ref(),
                 &DefaultMetadataLoader,
                 rustc_version_str().unwrap_or("unknown"),

src/tools/rust-analyzer/crates/proc-macro-srv/src/lib.rs

@@ -21,9 +21,7 @@ extern crate rustc_interface;
 extern crate rustc_lexer;
 extern crate rustc_metadata;
 extern crate rustc_proc_macro;
-extern crate rustc_session;
 extern crate rustc_span;
-extern crate rustc_target;
 
 mod bridge;
 mod dylib;