Show relocation diffs in function view when the data's content differs (#153)

* Show reloc diff in func view when data content differs

* Add "Relax shifted data diffs" option

* Display fake pool relocations at end of line

* Diff reloc data by display string instead of raw bytes

This is to handle data symbols that contain multiple values in them at once, such as stringBase. If you compare the target symbol's bytes directly, then any part of the symbol having different bytes will cause *all* relocations to that symbol to show as a diff, even if the specific string being accessed is the same.

* Fix weak stripped symbols showing as a false diff

Fixed this by showing extern symbols correctly instead of skipping them.

* Add "Relax shifted data diffs" option to objdiff-cli

Includes both a command line argument and a keyboard shortcut (S).

* Remove addi string data hack and ... pool name hack

* Clippy fix

* PPC: Clear relocs from GPRs when overwritten

* PPC: Follow branches to improve pool detection accuracy

* PPC: Handle following bctr jump table control flow

* Clippy fixes

* PPC: Fix extern relocations not having their addend copied

* Add option to disable func data value diffing

* PPC: Handle lmw when clearing GPRs

* PPC: Handle moving reloc address with `add` inst

* Combine "relax reloc diffs" with other reloc diff options

* Add v3 config and migrate from v2

---------

Co-authored-by: Luke Street <luke@street.dev>

Author: LagoLunatic

objdiff-cli/src/cmd/report.rs

@@ -169,7 +169,10 @@ fn report_object(
         }
         _ => {}
     }
-    let diff_config = diff::DiffObjConfig { relax_reloc_diffs: true, ..Default::default() };
+    let diff_config = diff::DiffObjConfig {
+        function_reloc_diffs: diff::FunctionRelocDiffs::None,
+        ..Default::default()
+    };
     let mapping_config = diff::MappingConfig::default();
     let target = object
         .target_path

objdiff-cli/src/views/function_diff.rs

@@ -3,7 +3,7 @@ use crossterm::event::{Event, KeyCode, KeyEventKind, KeyModifiers, MouseButton,
 use objdiff_core::{
     diff::{
         display::{display_diff, DiffText, HighlightKind},
-        ObjDiff, ObjInsDiffKind, ObjSymbolDiff,
+        FunctionRelocDiffs, ObjDiff, ObjInsDiffKind, ObjSymbolDiff,
     },
     obj::{ObjInfo, ObjSectionKind, ObjSymbol, SymbolRef},
 };
@@ -368,10 +368,15 @@ impl UiView for FunctionDiffUi {
                         self.scroll_x = self.scroll_x.saturating_sub(1);
                         result.redraw = true;
                     }
-                    // Toggle relax relocation diffs
+                    // Cycle through function relocation diff mode
                     KeyCode::Char('x') => {
-                        state.diff_obj_config.relax_reloc_diffs =
-                            !state.diff_obj_config.relax_reloc_diffs;
+                        state.diff_obj_config.function_reloc_diffs =
+                            match state.diff_obj_config.function_reloc_diffs {
+                                FunctionRelocDiffs::None => FunctionRelocDiffs::NameAddress,
+                                FunctionRelocDiffs::NameAddress => FunctionRelocDiffs::DataValue,
+                                FunctionRelocDiffs::DataValue => FunctionRelocDiffs::All,
+                                FunctionRelocDiffs::All => FunctionRelocDiffs::None,
+                            };
                         result.redraw = true;
                         return EventControlFlow::Reload;
                     }

objdiff-core/config-schema.json

@@ -1,11 +1,29 @@
 {
   "properties": [
     {
-      "id": "relaxRelocDiffs",
-      "type": "boolean",
-      "default": false,
-      "name": "Relax relocation diffs",
-      "description": "Ignores differences in relocation targets. (Address, name, etc)"
+      "id": "functionRelocDiffs",
+      "type": "choice",
+      "default": "name_address",
+      "name": "Function relocation diffs",
+      "description": "How relocation targets will be diffed in the function view.",
+      "items": [
+        {
+          "value": "none",
+          "name": "None"
+        },
+        {
+          "value": "name_address",
+          "name": "Name or address"
+        },
+        {
+          "value": "data_value",
+          "name": "Data value"
+        },
+        {
+          "value": "all",
+          "name": "Name or address, data value"
+        }
+      ]
     },
     {
       "id": "spaceBetweenArgs",
@@ -193,7 +211,7 @@
       "id": "general",
       "name": "General",
       "properties": [
-        "relaxRelocDiffs",
+        "functionRelocDiffs",
         "spaceBetweenArgs",
         "combineDataSections"
       ]

objdiff-core/src/arch/mod.rs

@@ -156,6 +156,17 @@ pub trait ObjArch: Send + Sync {
         Some(format!("Bytes: {:#x?}", bytes))
     }
 
+    fn display_ins_data(&self, ins: &ObjIns) -> Option<String> {
+        let reloc = ins.reloc.as_ref()?;
+        if reloc.addend >= 0 && reloc.target.bytes.len() > reloc.addend as usize {
+            self.guess_data_type(ins).and_then(|ty| {
+                self.display_data_type(ty, &reloc.target.bytes[reloc.addend as usize..])
+            })
+        } else {
+            None
+        }
+    }
+
     // Downcast methods
     #[cfg(feature = "ppc")]
     fn ppc(&self) -> Option<&ppc::ObjArchPpc> { None }