Fix escape char

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
+- Fix special character escaping in generated documentation so that `&`, `<`
+  and `>` do not break the generated Rust docs while preserving HTML tags.
 - Add `#[used]` to the generated interrupt vector table statics so they are not
   dropped by the linker with lto
 - Improve documentation for RISC-V settings file

src/util.rs

@@ -15,6 +15,10 @@ use syn::{
     punctuated::Punctuated, token::PathSep, Lit, LitInt, PathArguments, PathSegment, Type, TypePath,
 };
 
+use regex::Regex;
+use std::sync::OnceLock;
+
+
 use anyhow::{anyhow, Result};
 
 pub const BITS_PER_BYTE: u32 = 8;
@@ -177,13 +181,35 @@ pub fn escape_brackets(s: &str) -> String {
         })
 }
 
+static TAG_RE: OnceLock<Regex> = OnceLock::new();
+
 /// Escape basic html tags and brackets
 pub fn escape_special_chars(s: &str) -> Cow<'_, str> {
-    if s.contains('[') {
-        escape_brackets(s).into()
+    let tag_re= TAG_RE.get_or_init(|| Regex::new(r"<[^>]+>|&[a-zA-Z0-9#]+;").unwrap());
+
+    if !s.contains('[') && !s.contains('&') && !s.contains('<') && !s.contains('>') {
+        return s.into();
+    }
+
+    let mut last_end = 0;
+    let mut escaped = String::new();
+
+    for mat in tag_re.find_iter(s) {
+        let part = &s[last_end..mat.start()];
+        escaped.push_str(&part.replace('&', "&amp;").replace('<', "&lt;").replace('>', "&gt;"));
+        escaped.push_str(mat.as_str());
+        last_end = mat.end();
+    }
+    let remaining = &s[last_end..];
+
+    escaped.push_str(&remaining.replace('&', "&amp;").replace('<', "&lt;").replace('>', "&gt;"));
+
+    if escaped.contains('[') {
+        escape_brackets(&escaped).into()
     } else {
-        s.into()
+        escaped.into()
     }
+
 }
 
 pub fn name_of<T: FullName>(maybe_array: &MaybeArray<T>, ignore_group: bool) -> String {
@@ -513,3 +539,15 @@ fn pascalcase() {
     assert_eq!(to_pascal_case("FOO_BAR_1_2"), "FooBar1_2");
     assert_eq!(to_pascal_case("FOO_BAR_1_2_"), "FooBar1_2_");
 }
+
+#[test]
+fn test_escape_special_chars() {
+
+    assert_eq!(escape_special_chars("Enable & disable"), "Enable &amp; disable");
+    assert_eq!(escape_special_chars("Wait < 10"), "Wait &lt; 10");
+    assert_eq!(escape_special_chars("This is <b>bold</b>"), "This is <b>bold</b>");
+    assert_eq!(escape_special_chars("Use <div class=\"foo\">"), "Use <div class=\"foo\">");
+    assert_eq!(escape_special_chars("A &amp; B"), "A &amp; B");
+    assert_eq!(escape_special_chars("Array[0]"), "Array\\[0\\]");
+}
+