Fix data flow analysis for multiple text sections (#220)

* Fix data flow analysis for multiple text sections

* Data flow analysis results were only keyed by the symbol (function)
  address. That doen't work if there are multiple text sections, the
  result from the first function in one section will stomp the result
  from the first function in another because both have address zero.

* Remove the ambiguity by keying off of the section address as well.

* Formatting

* Satisfy wasm build

* Clippy

* Formatting again

* Thought that section was the section address not the section number.

---------

Co-authored-by: Luke Street <[email protected]>

Author: stravant

objdiff-core/src/diff/display.rs

@@ -189,7 +189,7 @@ pub fn display_row(
     let mut arg_idx = 0;
     let mut displayed_relocation = false;
     let analysis_result = if diff_config.show_data_flow {
-        obj.flow_analysis_results.get(&resolved.symbol.address)
+        obj.get_flow_analysis_result(resolved.symbol)
     } else {
         None
     };
@@ -217,7 +217,7 @@ pub fn display_row(
             }
             let data_flow_value =
             analysis_result.and_then(|result|
-                result.as_ref().get_argument_value_at_address(
+                result.get_argument_value_at_address(
                     ins_ref.address, (arg_idx - 1) as u8));
             match (arg, data_flow_value, resolved.ins_ref.branch_dest) {
                 // If we have a flow analysis result, always use that over anything else.

objdiff-core/src/obj/mod.rs

@@ -338,6 +338,20 @@ impl Object {
         self.symbols.iter().position(|symbol| symbol.section.is_some() && symbol.name == name)
     }
 
+    pub fn get_flow_analysis_result(&self, symbol: &Symbol) -> Option<&dyn FlowAnalysisResult> {
+        let key = symbol.section.unwrap_or_default() as u64 * 1024 * 1024 * 1024 + symbol.address;
+        self.flow_analysis_results.get(&key).map(|result| result.as_ref())
+    }
+
+    pub fn add_flow_analysis_result(
+        &mut self,
+        symbol: &Symbol,
+        result: Box<dyn FlowAnalysisResult>,
+    ) {
+        let key = symbol.section.unwrap_or_default() as u64 * 1024 * 1024 * 1024 + symbol.address;
+        self.flow_analysis_results.insert(key, result);
+    }
+
     pub fn has_flow_analysis_result(&self) -> bool { !self.flow_analysis_results.is_empty() }
 }
 

objdiff-core/src/obj/read.rs

@@ -1,4 +1,5 @@
 use alloc::{
+    boxed::Box,
     collections::BTreeMap,
     format,
     string::{String, ToString},
@@ -13,8 +14,8 @@ use crate::{
     arch::{Arch, new_arch},
     diff::DiffObjConfig,
     obj::{
-        Object, Relocation, RelocationFlags, Section, SectionData, SectionFlag, SectionKind,
-        Symbol, SymbolFlag, SymbolKind,
+        FlowAnalysisResult, Object, Relocation, RelocationFlags, Section, SectionData, SectionFlag,
+        SectionKind, Symbol, SymbolFlag, SymbolKind,
         split_meta::{SPLITMETA_SECTION, SplitMeta},
     },
     util::{align_data_slice_to, align_u64_to, read_u16, read_u32},
@@ -439,6 +440,7 @@ fn perform_data_flow_analysis(obj: &mut Object, config: &DiffObjConfig) -> Resul
     }
 
     let mut generated_relocations = Vec::<(usize, Vec<Relocation>)>::new();
+    let mut generated_flow_results = Vec::<(Symbol, Box<dyn FlowAnalysisResult>)>::new();
     for (section_index, section) in obj.sections.iter().enumerate() {
         if section.kind != SectionKind::Code {
             continue;
@@ -474,12 +476,17 @@ fn perform_data_flow_analysis(obj: &mut Object, config: &DiffObjConfig) -> Resul
 
             // Optional full data flow analysis
             if config.analyze_data_flow {
-                obj.arch.data_flow_analysis(obj, symbol, code, &section.relocations).and_then(
-                    |flow_result| obj.flow_analysis_results.insert(symbol.address, flow_result),
-                );
+                if let Some(flow_result) =
+                    obj.arch.data_flow_analysis(obj, symbol, code, &section.relocations)
+                {
+                    generated_flow_results.push((symbol.clone(), flow_result));
+                }
             }
         }
     }
+    for (symbol, flow_result) in generated_flow_results {
+        obj.add_flow_analysis_result(&symbol, flow_result);
+    }
     for (section_index, mut relocations) in generated_relocations {
         obj.sections[section_index].relocations.append(&mut relocations);
     }