Ignore PlainText segments when diffing

Author: encounter

objdiff-core/src/diff/code.rs

@@ -299,15 +299,10 @@ fn compare_ins(
 ) -> Result<InsDiffResult> {
     let mut result = InsDiffResult::default();
     if let (Some(left_ins), Some(right_ins)) = (&left.ins, &right.ins) {
-        if left_ins.args.len() != right_ins.args.len()
-            || left_ins.op != right_ins.op
-            // Check if any PlainText segments differ (punctuation and spacing)
-            // This indicates a more significant difference than a simple arg mismatch
-            || !left_ins.args.iter().zip(&right_ins.args).all(|(a, b)| match (a, b) {
-                (ObjInsArg::PlainText(l), ObjInsArg::PlainText(r)) => l == r,
-                _ => true,
-            })
-        {
+        // Count only non-PlainText args
+        let left_args_count = left_ins.iter_args().count();
+        let right_args_count = right_ins.iter_args().count();
+        if left_args_count != right_args_count || left_ins.op != right_ins.op {
             // Totally different op
             result.kind = ObjInsDiffKind::Replace;
             state.diff_count += 1;
@@ -318,7 +313,7 @@ fn compare_ins(
             result.kind = ObjInsDiffKind::OpMismatch;
             state.diff_count += 1;
         }
-        for (a, b) in left_ins.args.iter().zip(&right_ins.args) {
+        for (a, b) in left_ins.iter_args().zip(right_ins.iter_args()) {
             if arg_eq(config, left_obj, right_obj, a, b, left, right) {
                 result.left_args_diff.push(None);
                 result.right_args_diff.push(None);

objdiff-core/src/diff/display.rs

@@ -58,27 +58,31 @@ pub fn display_diff<E>(
         cb(DiffText::Spacing(4))?;
     }
     cb(DiffText::Opcode(&ins.mnemonic, ins.op))?;
+    let mut arg_diff_idx = 0; // non-PlainText index
     for (i, arg) in ins.args.iter().enumerate() {
         if i == 0 {
             cb(DiffText::Spacing(1))?;
         }
-        let diff = ins_diff.arg_diff.get(i).and_then(|o| o.as_ref());
+        let diff = ins_diff.arg_diff.get(arg_diff_idx).and_then(|o| o.as_ref());
         match arg {
             ObjInsArg::PlainText(s) => {
                 cb(DiffText::Basic(s))?;
             }
             ObjInsArg::Arg(v) => {
                 cb(DiffText::Argument(v, diff))?;
+                arg_diff_idx += 1;
             }
             ObjInsArg::Reloc => {
                 display_reloc_name(ins.reloc.as_ref().unwrap(), &mut cb, diff)?;
+                arg_diff_idx += 1;
             }
             ObjInsArg::BranchDest(dest) => {
                 if let Some(dest) = dest.checked_sub(base_addr) {
                     cb(DiffText::BranchDest(dest, diff))?;
                 } else {
                     cb(DiffText::Basic("<unknown>"))?;
                 }
+                arg_diff_idx += 1;
             }
         }
     }

objdiff-core/src/diff/mod.rs

@@ -245,7 +245,7 @@ pub struct ObjInsDiff {
     pub branch_from: Option<ObjInsBranchFrom>,
     /// Branches to instruction
     pub branch_to: Option<ObjInsBranchTo>,
-    /// Arg diffs
+    /// Arg diffs (only contains non-PlainText args)
     pub arg_diff: Vec<Option<ObjInsArgDiff>>,
 }
 

objdiff-core/src/obj/mod.rs

@@ -85,6 +85,9 @@ pub enum ObjInsArg {
 }
 
 impl ObjInsArg {
+    #[inline]
+    pub fn is_plain_text(&self) -> bool { matches!(self, ObjInsArg::PlainText(_)) }
+
     pub fn loose_eq(&self, other: &ObjInsArg) -> bool {
         match (self, other) {
             (ObjInsArg::Arg(a), ObjInsArg::Arg(b)) => a.loose_eq(b),
@@ -112,6 +115,14 @@ pub struct ObjIns {
     pub orig: Option<String>,
 }
 
+impl ObjIns {
+    /// Iterate over non-PlainText arguments.
+    #[inline]
+    pub fn iter_args(&self) -> impl DoubleEndedIterator<Item = &ObjInsArg> {
+        self.args.iter().filter(|a| !a.is_plain_text())
+    }
+}
+
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Default)]
 pub enum ObjSymbolKind {
     #[default]