rustdoc: unify the short-circuit on all lints

This is a bit of an experiment to see if it improves perf.

Author: notriddle

src/librustdoc/passes/lint.rs

@@ -27,12 +27,33 @@ pub(crate) fn run_lints(krate: Crate, cx: &mut DocContext<'_>) -> Crate {
 
 impl<'a, 'tcx> DocVisitor for Linter<'a, 'tcx> {
     fn visit_item(&mut self, item: &Item) {
-        bare_urls::visit_item(self.cx, item);
-        check_code_block_syntax::visit_item(self.cx, item);
-        html_tags::visit_item(self.cx, item);
-        unescaped_backticks::visit_item(self.cx, item);
-        redundant_explicit_links::visit_item(self.cx, item);
-        unportable_markdown::visit_item(self.cx, item);
+        let Some(hir_id) = DocContext::as_local_hir_id(self.cx.tcx, item.item_id) else {
+            // If non-local, no need to check anything.
+            return;
+        };
+        let dox = item.doc_value();
+        if !dox.is_empty() {
+            let may_have_link = dox.contains(&[':', '['][..]);
+            let may_have_block_comment_or_html = dox.contains(&['<', '>']);
+            // ~~~rust
+            // // This is a real, supported commonmark syntax for block code
+            // ~~~
+            let may_have_code = dox.contains(&['~', '`', '\t'][..]) || dox.contains("    ");
+            if may_have_link {
+                bare_urls::visit_item(self.cx, item, hir_id, &dox);
+                redundant_explicit_links::visit_item(self.cx, item, hir_id);
+            }
+            if may_have_code {
+                check_code_block_syntax::visit_item(self.cx, item, &dox);
+                unescaped_backticks::visit_item(self.cx, item, hir_id, &dox);
+            }
+            if may_have_block_comment_or_html {
+                html_tags::visit_item(self.cx, item, hir_id, &dox);
+                unportable_markdown::visit_item(self.cx, item, hir_id, &dox);
+            } else if may_have_link {
+                unportable_markdown::visit_item(self.cx, item, hir_id, &dox);
+            }
+        }
 
         self.visit_item_recur(item)
     }

src/librustdoc/passes/lint/bare_urls.rs

@@ -8,57 +8,51 @@ use std::sync::LazyLock;
 use pulldown_cmark::{Event, Parser, Tag};
 use regex::Regex;
 use rustc_errors::Applicability;
+use rustc_hir::HirId;
 use rustc_resolve::rustdoc::source_span_for_markdown_range;
 use tracing::trace;
 
 use crate::clean::*;
 use crate::core::DocContext;
 use crate::html::markdown::main_body_opts;
 
-pub(super) fn visit_item(cx: &DocContext<'_>, item: &Item) {
-    let Some(hir_id) = DocContext::as_local_hir_id(cx.tcx, item.item_id) else {
-        // If non-local, no need to check anything.
-        return;
+pub(super) fn visit_item(cx: &DocContext<'_>, item: &Item, hir_id: HirId, dox: &str) {
+    let report_diag = |cx: &DocContext<'_>, msg: &'static str, range: Range<usize>| {
+        let sp = source_span_for_markdown_range(cx.tcx, &dox, &range, &item.attrs.doc_strings)
+            .unwrap_or_else(|| item.attr_span(cx.tcx));
+        cx.tcx.node_span_lint(crate::lint::BARE_URLS, hir_id, sp, |lint| {
+            lint.primary_message(msg)
+                .note("bare URLs are not automatically turned into clickable links")
+                .multipart_suggestion(
+                    "use an automatic link instead",
+                    vec![
+                        (sp.shrink_to_lo(), "<".to_string()),
+                        (sp.shrink_to_hi(), ">".to_string()),
+                    ],
+                    Applicability::MachineApplicable,
+                );
+        });
     };
-    let dox = item.doc_value();
-    if !dox.is_empty() {
-        let report_diag = |cx: &DocContext<'_>, msg: &'static str, range: Range<usize>| {
-            let sp = source_span_for_markdown_range(cx.tcx, &dox, &range, &item.attrs.doc_strings)
-                .unwrap_or_else(|| item.attr_span(cx.tcx));
-            cx.tcx.node_span_lint(crate::lint::BARE_URLS, hir_id, sp, |lint| {
-                lint.primary_message(msg)
-                    .note("bare URLs are not automatically turned into clickable links")
-                    .multipart_suggestion(
-                        "use an automatic link instead",
-                        vec![
-                            (sp.shrink_to_lo(), "<".to_string()),
-                            (sp.shrink_to_hi(), ">".to_string()),
-                        ],
-                        Applicability::MachineApplicable,
-                    );
-            });
-        };
 
-        let mut p = Parser::new_ext(&dox, main_body_opts()).into_offset_iter();
+    let mut p = Parser::new_ext(&dox, main_body_opts()).into_offset_iter();
 
-        while let Some((event, range)) = p.next() {
-            match event {
-                Event::Text(s) => find_raw_urls(cx, &s, range, &report_diag),
-                // We don't want to check the text inside code blocks or links.
-                Event::Start(tag @ (Tag::CodeBlock(_) | Tag::Link { .. })) => {
-                    while let Some((event, _)) = p.next() {
-                        match event {
-                            Event::End(end)
-                                if mem::discriminant(&end) == mem::discriminant(&tag.to_end()) =>
-                            {
-                                break;
-                            }
-                            _ => {}
+    while let Some((event, range)) = p.next() {
+        match event {
+            Event::Text(s) => find_raw_urls(cx, &s, range, &report_diag),
+            // We don't want to check the text inside code blocks or links.
+            Event::Start(tag @ (Tag::CodeBlock(_) | Tag::Link { .. })) => {
+                while let Some((event, _)) = p.next() {
+                    match event {
+                        Event::End(end)
+                            if mem::discriminant(&end) == mem::discriminant(&tag.to_end()) =>
+                        {
+                            break;
                         }
+                        _ => {}
                     }
                 }
-                _ => {}
             }
+            _ => {}
         }
     }
 }

src/librustdoc/passes/lint/check_code_block_syntax.rs

@@ -15,10 +15,8 @@ use crate::clean;
 use crate::core::DocContext;
 use crate::html::markdown::{self, RustCodeBlock};
 
-pub(crate) fn visit_item(cx: &DocContext<'_>, item: &clean::Item) {
-    if let Some(def_id) = item.item_id.as_local_def_id()
-        && let Some(dox) = &item.opt_doc_value()
-    {
+pub(crate) fn visit_item(cx: &DocContext<'_>, item: &clean::Item, dox: &str) {
+    if let Some(def_id) = item.item_id.as_local_def_id() {
         let sp = item.attr_span(cx.tcx);
         let extra = crate::html::markdown::ExtraInfo::new(cx.tcx, def_id, sp);
         for code_block in markdown::rust_code_blocks(dox, &extra) {