Improve automatic symbol pairing for functions with compiler-generated names

objdiff-core/src/diff/data.rs

@@ -36,12 +36,25 @@ pub fn diff_bss_symbol(
 }
 
 pub fn symbol_name_matches(left_name: &str, right_name: &str) -> bool {
-    // Match Metrowerks symbol$1234 against symbol$2345
-    // and GCC symbol.1234 against symbol.2345
-    if let Some((prefix, suffix)) = left_name.split_once(['$', '.']) {
-        if !suffix.chars().all(char::is_numeric) {
-            return false;
+    if let Some((left_prefix, left_suffix)) = left_name.split_once("@class$")
+        && let Some((right_prefix, right_suffix)) = right_name.split_once("@class$")
+    {
+        // Match Metrowerks anonymous class symbol names, ignoring the unique ID.
+        // e.g. __dt__Q29dCamera_c23@class$3665d_camera_cppFv
+        if left_prefix == right_prefix
+            && let Some(left_idx) = left_suffix.chars().position(|c| !c.is_numeric())
+            && let Some(right_idx) = right_suffix.chars().position(|c| !c.is_numeric())
+        {
+            // e.g. d_camera_cppFv (after the unique ID)
+            left_suffix[left_idx..] == right_suffix[right_idx..]
+        } else {
+            false
         }
+    } else if let Some((prefix, suffix)) = left_name.split_once(['$', '.'])
+        && suffix.chars().all(char::is_numeric)
+    {
+        // Match Metrowerks symbol$1234 against symbol$2345
+        // and GCC symbol.1234 against symbol.2345
         right_name
             .split_once(['$', '.'])
             .is_some_and(|(p, s)| p == prefix && s.chars().all(char::is_numeric))

objdiff-core/src/diff/mod.rs

@@ -7,6 +7,7 @@ use alloc::{
 use core::{num::NonZeroU32, ops::Range};
 
 use anyhow::Result;
+use itertools::Itertools;
 
 use crate::{
     diff::{
@@ -759,18 +760,16 @@ fn find_symbol(
         return closest_match_symbol_idx;
     }
 
-    // Try to find an exact name match
-    if let Some((symbol_idx, _)) = unmatched_symbols(obj, used).find(|(_, symbol)| {
-        symbol.name == in_symbol.name && symbol_section_kind(obj, symbol) == section_kind
-    }) {
-        return Some(symbol_idx);
-    }
-
-    if let Some((symbol_idx, _)) = unmatched_symbols(obj, used).find(|&(_, symbol)| {
-        symbol_name_matches(&in_symbol.name, &symbol.name)
-            && symbol_section_kind(obj, symbol) == section_kind
-            && symbol_section(obj, symbol).is_some_and(|(name, _)| name == section_name)
-    }) {
+    // Try to find a symbol with a matching name
+    if let Some((symbol_idx, _)) = unmatched_symbols(obj, used)
+        .filter(|&(_, symbol)| {
+            symbol_name_matches(&in_symbol.name, &symbol.name)
+                && symbol_section_kind(obj, symbol) == section_kind
+                && symbol_section(obj, symbol).is_some_and(|(name, _)| name == section_name)
+        })
+        .sorted_unstable_by_key(|&(_, symbol)| (symbol.section, symbol.address))
+        .next()
+    {
         return Some(symbol_idx);
     }