4 files changed, 46 insertions, 8 deletions

diff --git a/crates/ide/src/syntax_highlighting/inject.rs b/crates/ide/src/syntax_highlighting/inject.rs
index 04fafd244..855c7fba8 100644
--- a/crates/ide/src/syntax_highlighting/inject.rs
+++ b/crates/ide/src/syntax_highlighting/inject.rs
@@ -90,6 +90,13 @@ const RUSTDOC_FENCE_TOKENS: &[&'static str] = &[
     "edition2021",
 ];
 
+fn is_rustdoc_fence_token(token: &str) -> bool {
+    if RUSTDOC_FENCE_TOKENS.contains(&token) {
+        return true;
+    }
+    token.starts_with('E') && token.len() == 5 && token[1..].parse::<u32>().is_ok()
+}
+
 /// Injection of syntax highlighting of doctests.
 pub(super) fn doc_comment(
     hl: &mut Highlights,
@@ -174,8 +181,7 @@ pub(super) fn doc_comment(
                     is_codeblock = !is_codeblock;
                     // Check whether code is rust by inspecting fence guards
                     let guards = &line[idx + RUSTDOC_FENCE.len()..];
-                    let is_rust =
-                        guards.split(',').all(|sub| RUSTDOC_FENCE_TOKENS.contains(&sub.trim()));
+                    let is_rust = guards.split(',').all(|sub| is_rustdoc_fence_token(sub.trim()));
                     is_doctest = is_codeblock && is_rust;
                     continue;
                 }
diff --git a/crates/mbe/src/syntax_bridge.rs b/crates/mbe/src/syntax_bridge.rs
index 9ba98f7fb..a7c8c13c6 100644
--- a/crates/mbe/src/syntax_bridge.rs
+++ b/crates/mbe/src/syntax_bridge.rs
@@ -213,7 +213,7 @@ fn doc_comment_text(comment: &ast::Comment) -> SmolStr {
 
     // Quote the string
     // Note that `tt::Literal` expect an escaped string
-    let text = format!("{:?}", text.escape_debug().to_string());
+    let text = format!("\"{}\"", text.escape_debug());
     text.into()
 }
 
diff --git a/crates/mbe/src/tests/expand.rs b/crates/mbe/src/tests/expand.rs
index 146b236e2..3a1d840ea 100644
--- a/crates/mbe/src/tests/expand.rs
+++ b/crates/mbe/src/tests/expand.rs
@@ -936,7 +936,7 @@ fn test_meta_doc_comments() {
                 MultiLines Doc
             */
         }"#,
-        "# [doc = \" Single Line Doc 1\"] # [doc = \"\\\\n                MultiLines Doc\\\\n            \"] fn bar () {}",
+        "# [doc = \" Single Line Doc 1\"] # [doc = \"\\n                MultiLines Doc\\n            \"] fn bar () {}",
     );
 }
 
@@ -977,7 +977,27 @@ fn test_meta_doc_comments_non_latin() {
                 莊生曉夢迷蝴蝶，望帝春心託杜鵑。
             */
         }"#,
-        "# [doc = \" 錦瑟無端五十弦，一弦一柱思華年。\"] # [doc = \"\\\\n                莊生曉夢迷蝴蝶，望帝春心託杜鵑。\\\\n            \"] fn bar () {}",
+        "# [doc = \" 錦瑟無端五十弦，一弦一柱思華年。\"] # [doc = \"\\n                莊生曉夢迷蝴蝶，望帝春心託杜鵑。\\n            \"] fn bar () {}",
+    );
+}
+
+#[test]
+fn test_meta_doc_comments_escaped_characters() {
+    parse_macro(
+        r#"
+        macro_rules! foo {
+            ($(#[$ i:meta])+) => (
+                $(#[$ i])+
+                fn bar() {}
+            )
+        }
+"#,
+    )
+    .assert_expand_items(
+        r#"foo! {
+            /// \ " '
+        }"#,
+        r#"# [doc = " \\ \" \'"] fn bar () {}"#,
     );
 }
 
diff --git a/crates/rust-analyzer/src/markdown.rs b/crates/rust-analyzer/src/markdown.rs
index 865eaae9b..a51ff89e4 100644
--- a/crates/rust-analyzer/src/markdown.rs
+++ b/crates/rust-analyzer/src/markdown.rs
@@ -27,9 +27,8 @@ pub(crate) fn format_docs(src: &str) -> String {
             in_code_block ^= true;
 
             if in_code_block {
-                is_rust = header
-                    .split(',')
-                    .all(|sub| RUSTDOC_CODE_BLOCK_ATTRIBUTES_RUST_SPECIFIC.contains(&sub.trim()));
+                is_rust =
+                    header.split(',').all(|sub| is_rust_specific_code_block_attribute(sub.trim()));
 
                 if is_rust {
                     line = "```rust";
@@ -42,6 +41,13 @@ pub(crate) fn format_docs(src: &str) -> String {
     processed_lines.join("\n")
 }
 
+fn is_rust_specific_code_block_attribute(attr: &str) -> bool {
+    if RUSTDOC_CODE_BLOCK_ATTRIBUTES_RUST_SPECIFIC.contains(&attr) {
+        return true;
+    }
+    attr.starts_with('E') && attr.len() == 5 && attr[1..].parse::<u32>().is_ok()
+}
+
 fn code_line_ignored_by_rustdoc(line: &str) -> bool {
     let trimmed = line.trim();
     trimmed == "#" || trimmed.starts_with("# ") || trimmed.starts_with("#\t")
@@ -82,6 +88,12 @@ mod tests {
     }
 
     #[test]
+    fn test_format_docs_handles_error_codes() {
+        let comment = "```compile_fail,E0641\nlet b = 0 as *const _;\n```";
+        assert_eq!(format_docs(comment), "```rust\nlet b = 0 as *const _;\n```");
+    }
+
+    #[test]
     fn test_format_docs_skips_comments_in_rust_block() {
         let comment =
             "```rust\n # skip1\n# skip2\n#stay1\nstay2\n#\n #\n   #    \n #\tskip3\n\t#\t\n```";