Check relocation addends when diffing functions

Author: LagoLunatic

objdiff-core/src/diff/code.rs

@@ -192,8 +192,18 @@ fn resolve_branches(vec: &mut [ObjInsDiff]) {
     }
 }
 
-fn address_eq(left: &ObjReloc, right: &ObjReloc) -> bool {
-    left.target.address as i64 + left.addend == right.target.address as i64 + right.addend
+pub fn address_eq(left: &ObjReloc, right: &ObjReloc) -> bool {
+    if right.target.size == 0 && left.target.size != 0 {
+        // The base relocation is against a pool but the target relocation isn't.
+        // This can happen in rare cases where the compiler will generate a pool+addend relocation
+        // in the base's data, but the one detected in the target is direct with no addend.
+        // Just check that the final address is the same so these count as a match.
+        left.target.address as i64 + left.addend == right.target.address as i64 + right.addend
+    } else {
+        // But otherwise, if the compiler isn't using a pool, we're more strict and check that the
+        // target symbol address and relocation addend both match exactly.
+        left.target.address == right.target.address && left.addend == right.addend
+    }
 }
 
 pub fn section_name_eq(
@@ -235,13 +245,14 @@ fn reloc_eq(
         return true;
     }
 
-    let symbol_name_matches = left.target.name == right.target.name;
+    let symbol_name_addend_matches =
+        left.target.name == right.target.name && left.addend == right.addend;
     match (&left.target.orig_section_index, &right.target.orig_section_index) {
         (Some(sl), Some(sr)) => {
-            // Match if section and name or address match
+            // Match if section and name+addend or address match
             section_name_eq(left_obj, right_obj, *sl, *sr)
                 && (config.function_reloc_diffs == FunctionRelocDiffs::DataValue
-                    || symbol_name_matches
+                    || symbol_name_addend_matches
                     || address_eq(left, right))
                 && (config.function_reloc_diffs == FunctionRelocDiffs::NameAddress
                     || left.target.kind != ObjSymbolKind::Object
@@ -251,9 +262,9 @@ fn reloc_eq(
         (Some(_), None) => false,
         (None, Some(_)) => {
             // Match if possibly stripped weak symbol
-            symbol_name_matches && right.target.flags.0.contains(ObjSymbolFlags::Weak)
+            symbol_name_addend_matches && right.target.flags.0.contains(ObjSymbolFlags::Weak)
         }
-        (None, None) => symbol_name_matches,
+        (None, None) => symbol_name_addend_matches,
     }
 }
 

objdiff-core/src/diff/data.rs

@@ -6,7 +6,7 @@ use std::{
 use anyhow::{anyhow, Result};
 use similar::{capture_diff_slices_deadline, get_diff_ratio, Algorithm};
 
-use super::code::section_name_eq;
+use super::code::{address_eq, section_name_eq};
 use crate::{
     diff::{ObjDataDiff, ObjDataDiffKind, ObjDataRelocDiff, ObjSectionDiff, ObjSymbolDiff},
     obj::{ObjInfo, ObjReloc, ObjSection, ObjSymbolFlags, SymbolRef},
@@ -41,39 +41,25 @@ pub fn no_diff_symbol(_obj: &ObjInfo, symbol_ref: SymbolRef) -> ObjSymbolDiff {
     ObjSymbolDiff { symbol_ref, target_symbol: None, instructions: vec![], match_percent: None }
 }
 
-fn address_eq(left: &ObjReloc, right: &ObjReloc) -> bool {
-    if right.target.size == 0 && left.target.size != 0 {
-        // The base relocation is against a pool but the target relocation isn't.
-        // This can happen in rare cases where the compiler will generate a pool+addend relocation
-        // in the base, but the one detected in the target is direct with no addend.
-        // Just check that the final address is the same so these count as a match.
-        left.target.address as i64 + left.addend == right.target.address as i64 + right.addend
-    } else {
-        // But otherwise, if the compiler isn't using a pool, we're more strict and check that the
-        // target symbol address and relocation addend both match exactly.
-        left.target.address == right.target.address && left.addend == right.addend
-    }
-}
-
 fn reloc_eq(left_obj: &ObjInfo, right_obj: &ObjInfo, left: &ObjReloc, right: &ObjReloc) -> bool {
     if left.flags != right.flags {
         return false;
     }
 
-    let symbol_name_matches = left.target.name == right.target.name;
+    let symbol_name_addend_matches =
+        left.target.name == right.target.name && left.addend == right.addend;
     match (&left.target.orig_section_index, &right.target.orig_section_index) {
         (Some(sl), Some(sr)) => {
             // Match if section and name+addend or address match
             section_name_eq(left_obj, right_obj, *sl, *sr)
-                && ((symbol_name_matches && left.addend == right.addend) || address_eq(left, right))
+                && (symbol_name_addend_matches || address_eq(left, right))
         }
         (Some(_), None) => false,
         (None, Some(_)) => {
             // Match if possibly stripped weak symbol
-            (symbol_name_matches && left.addend == right.addend)
-                && right.target.flags.0.contains(ObjSymbolFlags::Weak)
+            symbol_name_addend_matches && right.target.flags.0.contains(ObjSymbolFlags::Weak)
         }
-        (None, None) => symbol_name_matches,
+        (None, None) => symbol_name_addend_matches,
     }
 }