Implementation of basic data flow analysis for PowerPC (#212)

* WIP implementation

* * Move flow analysis to dedicated file
* Show string constants inline
* Handle calls to MWCC "sled" helpers which otherwise disrupt flow analysis

* Run cargo insta review

* Apply clippy feedback

* Update more tests.

* Remove std use from ppc flow analysis

* Try to make wasm build work again

* More test changes

* Probably last wasm fix

* Formatting

* Fix WASM

* One more clippy thing

* Fixed display of float constants in a LFS or LFD instruction in case where there is a branch to the subsequent instruction with a different register value.

* On lines with a reloc, only hide Symbol type data flow values rather than all data flow values.

* Formatting

objdiff-gui/src/views/appearance.rs

@@ -23,6 +23,8 @@ pub struct Appearance {
     #[serde(skip)]
     pub highlight_color: Color32, // WHITE
     #[serde(skip)]
+    pub dataflow_color: Color32, //
+    #[serde(skip)]
     pub replace_color: Color32, // LIGHT_BLUE
     #[serde(skip)]
     pub insert_color: Color32, // GREEN
@@ -61,6 +63,7 @@ impl Default for Appearance {
             emphasized_text_color: Color32::LIGHT_GRAY,
             deemphasized_text_color: Color32::DARK_GRAY,
             highlight_color: Color32::WHITE,
+            dataflow_color: Color32::from_rgb(0, 128, 128),
             replace_color: Color32::LIGHT_BLUE,
             insert_color: Color32::GREEN,
             delete_color: Color32::from_rgb(200, 40, 41),
@@ -104,6 +107,7 @@ impl Appearance {
                 self.emphasized_text_color = Color32::LIGHT_GRAY;
                 self.deemphasized_text_color = Color32::DARK_GRAY;
                 self.highlight_color = Color32::WHITE;
+                self.dataflow_color = Color32::from_rgb(0, 128, 128);
                 self.replace_color = Color32::LIGHT_BLUE;
                 self.insert_color = Color32::GREEN;
                 self.delete_color = Color32::from_rgb(200, 40, 41);
@@ -114,6 +118,7 @@ impl Appearance {
                 self.emphasized_text_color = Color32::DARK_GRAY;
                 self.deemphasized_text_color = Color32::LIGHT_GRAY;
                 self.highlight_color = Color32::BLACK;
+                self.dataflow_color = Color32::from_rgb(0, 128, 128);
                 self.replace_color = Color32::DARK_BLUE;
                 self.insert_color = Color32::DARK_GREEN;
                 self.delete_color = Color32::from_rgb(200, 40, 41);

objdiff-gui/src/views/diff.rs

@@ -281,6 +281,24 @@ pub fn diff_view_ui(
                     })
                 });
             }
+
+            // Only need to check the first Object. Technically the first could not have a flow analysis
+            // result while the second does but we don't want to waste space on two separate checkboxes.
+            if state.current_view == View::FunctionDiff
+                && result
+                    .first_obj
+                    .as_ref()
+                    .is_some_and(|(first, _)| first.has_flow_analysis_result())
+            {
+                let mut value = diff_config.show_data_flow;
+                if ui
+                    .checkbox(&mut value, "Show data flow")
+                    .on_hover_text("Show data flow analysis results in place of register names")
+                    .clicked()
+                {
+                    ret = Some(DiffViewAction::SetShowDataFlow(value));
+                }
+            }
         } else if column == 1 {
             // Right column
 

objdiff-gui/src/views/function_diff.rs

@@ -174,6 +174,7 @@ fn diff_text_ui(
         DiffTextColor::Normal => appearance.text_color,
         DiffTextColor::Dim => appearance.deemphasized_text_color,
         DiffTextColor::Bright => appearance.emphasized_text_color,
+        DiffTextColor::DataFlow => appearance.dataflow_color,
         DiffTextColor::Replace => appearance.replace_color,
         DiffTextColor::Delete => appearance.delete_color,
         DiffTextColor::Insert => appearance.insert_color,

objdiff-gui/src/views/symbol_diff.rs

@@ -79,6 +79,8 @@ pub enum DiffViewAction {
     SetMapping(usize, usize),
     /// Set the show_mapped_symbols flag
     SetShowMappedSymbols(bool),
+    /// Set the show_data_flow flag
+    SetShowDataFlow(bool),
 }
 
 #[derive(Debug, Clone, Default, Eq, PartialEq)]
@@ -350,6 +352,12 @@ impl DiffViewState {
             DiffViewAction::SetShowMappedSymbols(value) => {
                 self.symbol_state.show_mapped_symbols = value;
             }
+            DiffViewAction::SetShowDataFlow(value) => {
+                let Ok(mut state) = state.write() else {
+                    return;
+                };
+                state.config.diff_obj_config.show_data_flow = value;
+            }
         }
     }