Fix missing common BSS symbols

Resolves #128

Cargo.lock

@@ -2861,7 +2861,7 @@ dependencies = [
 
 [[package]]
 name = "objdiff-cli"
-version = "2.3.3"
+version = "2.3.4"
 dependencies = [
  "anyhow",
  "argp",
@@ -2883,7 +2883,7 @@ dependencies = [
 
 [[package]]
 name = "objdiff-core"
-version = "2.3.3"
+version = "2.3.4"
 dependencies = [
  "anyhow",
  "arm-attr",
@@ -2923,7 +2923,7 @@ dependencies = [
 
 [[package]]
 name = "objdiff-gui"
-version = "2.3.3"
+version = "2.3.4"
 dependencies = [
  "anyhow",
  "bytes",

Cargo.toml

@@ -13,7 +13,7 @@ strip = "debuginfo"
 codegen-units = 1
 
 [workspace.package]
-version = "2.3.3"
+version = "2.3.4"
 authors = ["Luke Street <luke@street.dev>"]
 edition = "2021"
 license = "MIT OR Apache-2.0"

objdiff-core/src/diff/mod.rs

@@ -11,7 +11,7 @@ use crate::{
             diff_generic_section, no_diff_symbol,
         },
     },
-    obj::{ObjInfo, ObjIns, ObjSection, ObjSectionKind, ObjSymbol, SymbolRef},
+    obj::{ObjInfo, ObjIns, ObjSection, ObjSectionKind, ObjSymbol, SymbolRef, SECTION_COMMON},
 };
 
 pub mod code;
@@ -340,7 +340,7 @@ impl ObjDiff {
         }
         for (symbol_idx, _) in obj.common.iter().enumerate() {
             result.common.push(ObjSymbolDiff {
-                symbol_ref: SymbolRef { section_idx: obj.sections.len(), symbol_idx },
+                symbol_ref: SymbolRef { section_idx: SECTION_COMMON, symbol_idx },
                 target_symbol: None,
                 instructions: vec![],
                 match_percent: None,
@@ -361,7 +361,7 @@ impl ObjDiff {
 
     #[inline]
     pub fn symbol_diff(&self, symbol_ref: SymbolRef) -> &ObjSymbolDiff {
-        if symbol_ref.section_idx == self.sections.len() {
+        if symbol_ref.section_idx == SECTION_COMMON {
             &self.common[symbol_ref.symbol_idx]
         } else {
             &self.section_diff(symbol_ref.section_idx).symbols[symbol_ref.symbol_idx]
@@ -370,7 +370,7 @@ impl ObjDiff {
 
     #[inline]
     pub fn symbol_diff_mut(&mut self, symbol_ref: SymbolRef) -> &mut ObjSymbolDiff {
-        if symbol_ref.section_idx == self.sections.len() {
+        if symbol_ref.section_idx == SECTION_COMMON {
             &mut self.common[symbol_ref.symbol_idx]
         } else {
             &mut self.section_diff_mut(symbol_ref.section_idx).symbols[symbol_ref.symbol_idx]
@@ -758,7 +758,7 @@ fn matching_symbols(
             }
         }
         for (symbol_idx, symbol) in left.common.iter().enumerate() {
-            let symbol_ref = SymbolRef { section_idx: left.sections.len(), symbol_idx };
+            let symbol_ref = SymbolRef { section_idx: SECTION_COMMON, symbol_idx };
             if left_used.contains(&symbol_ref) {
                 continue;
             }
@@ -790,7 +790,7 @@ fn matching_symbols(
             }
         }
         for (symbol_idx, symbol) in right.common.iter().enumerate() {
-            let symbol_ref = SymbolRef { section_idx: right.sections.len(), symbol_idx };
+            let symbol_ref = SymbolRef { section_idx: SECTION_COMMON, symbol_idx };
             if right_used.contains(&symbol_ref) {
                 continue;
             }
@@ -883,7 +883,7 @@ fn find_common_symbol(obj: Option<&ObjInfo>, in_symbol: &ObjSymbol) -> Option<Sy
     let obj = obj?;
     for (symbol_idx, symbol) in obj.common.iter().enumerate() {
         if symbol.name == in_symbol.name {
-            return Some(SymbolRef { section_idx: obj.sections.len(), symbol_idx });
+            return Some(SymbolRef { section_idx: SECTION_COMMON, symbol_idx });
         }
     }
     None

objdiff-core/src/obj/mod.rs

@@ -164,9 +164,11 @@ pub struct SymbolRef {
     pub symbol_idx: usize,
 }
 
+pub const SECTION_COMMON: usize = usize::MAX - 1;
+
 impl ObjInfo {
     pub fn section_symbol(&self, symbol_ref: SymbolRef) -> (Option<&ObjSection>, &ObjSymbol) {
-        if symbol_ref.section_idx == self.sections.len() {
+        if symbol_ref.section_idx == SECTION_COMMON {
             let symbol = &self.common[symbol_ref.symbol_idx];
             return (None, symbol);
         }

objdiff-gui/src/views/symbol_diff.rs

@@ -7,7 +7,9 @@ use egui::{
 use objdiff_core::{
     arch::ObjArch,
     diff::{display::HighlightKind, ObjDiff, ObjSymbolDiff},
-    obj::{ObjInfo, ObjSection, ObjSectionKind, ObjSymbol, ObjSymbolFlags, SymbolRef},
+    obj::{
+        ObjInfo, ObjSection, ObjSectionKind, ObjSymbol, ObjSymbolFlags, SymbolRef, SECTION_COMMON,
+    },
 };
 use regex::{Regex, RegexBuilder};
 
@@ -651,11 +653,11 @@ pub fn symbol_list_ui(
             ui.style_mut().wrap_mode = Some(egui::TextWrapMode::Extend);
 
             // Skip sections with all symbols filtered out
-            if mapping.keys().any(|symbol_ref| symbol_ref.section_idx == usize::MAX) {
+            if mapping.keys().any(|symbol_ref| symbol_ref.section_idx == SECTION_COMMON) {
                 CollapsingHeader::new(".comm").default_open(true).show(ui, |ui| {
                     for (symbol_ref, symbol_diff) in mapping
                         .iter()
-                        .filter(|(symbol_ref, _)| symbol_ref.section_idx == usize::MAX)
+                        .filter(|(symbol_ref, _)| symbol_ref.section_idx == SECTION_COMMON)
                     {
                         let symbol = ctx.obj.section_symbol(*symbol_ref).1;
                         if let Some(result) = symbol_ui(