tweak logic for detecting anonymous MSVC symbols

Author: rjkiv

objdiff-core/src/obj/read.rs

@@ -60,16 +60,16 @@ fn get_normalized_symbol_name(name: &str) -> Option<String> {
     {
         // Match GCC symbol.1234 against symbol.2345
         Some(format!("{prefix}.{DUMMY_UNIQUE_ID}"))
-    } else if name.starts_with('?') {
-        // We're likely working with an MSVC symbol, so check for anonymous namespaces and zero out the hashes
-        Some(
-            Regex::new(r"\?A0x[0-9A-Fa-f]{8}@@")
-                .unwrap()
-                .replace_all(name, format!("?Ax{DUMMY_UNIQUE_MSVC_ID}@@"))
-                .to_string(),
-        )
     } else {
-        None
+        let re = Regex::new(r"\?A0x[0-9A-Fa-f]{8}@@").unwrap();
+        // Match MSVC anonymous class symbol names, ignoring the unique ID.
+        // e.g. ?CheckContextOr@?A0x24773155@@YA_NPBVDataArray@@@Z
+        // and: ?CheckContextOr@?A0xddf6240c@@YA_NPBVDataArray@@@Z
+        if name.starts_with('?') && re.is_match(name) {
+            Some(re.replace_all(name, format!("?Ax{DUMMY_UNIQUE_MSVC_ID}@@")).to_string())
+        } else {
+            None
+        }
     }
 }