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

Author: stravant

objdiff-cli/src/views/function_diff.rs

@@ -570,6 +570,7 @@ impl FunctionDiffUi {
                     DiffTextColor::Normal => Color::Gray,
                     DiffTextColor::Dim => Color::DarkGray,
                     DiffTextColor::Bright => Color::White,
+                    DiffTextColor::DataFlow => Color::LightCyan,
                     DiffTextColor::Replace => Color::Cyan,
                     DiffTextColor::Delete => Color::Red,
                     DiffTextColor::Insert => Color::Green,

objdiff-core/Cargo.toml

@@ -175,7 +175,7 @@ time = { version = "0.3", optional = true }
 encoding_rs = { version = "0.8.35", optional = true }
 
 [target.'cfg(windows)'.dependencies]
-winapi = { version = "0.3", optional = true }
+winapi = { version = "0.3", optional = true, features = ["winbase"] }
 
 # For Linux static binaries, use rustls
 [target.'cfg(target_os = "linux")'.dependencies]

objdiff-core/config-schema.json

@@ -25,6 +25,20 @@
         }
       ]
     },
+    {
+      "id": "analyzeDataFlow",
+      "type": "boolean",
+      "default": false,
+      "name": "(Experimental) Perform data flow analysis",
+      "description": "Use data flow analysis to display known information about register contents where possible"
+    },
+    {
+      "id": "showDataFlow",
+      "type": "boolean",
+      "default": true,
+      "name": "Show data flow",
+      "description": "Show data flow analysis results in place of register name where present"
+    },
     {
       "id": "spaceBetweenArgs",
       "type": "boolean",
@@ -264,7 +278,8 @@
       "id": "ppc",
       "name": "PowerPC",
       "properties": [
-        "ppc.calculatePoolRelocations"
+        "ppc.calculatePoolRelocations",
+        "analyzeDataFlow"
       ]
     },
     {

objdiff-core/src/arch/mod.rs

@@ -1,5 +1,8 @@
 use alloc::{borrow::Cow, boxed::Box, format, string::String, vec::Vec};
-use core::{ffi::CStr, fmt, fmt::Debug};
+use core::{
+    ffi::CStr,
+    fmt::{self, Debug},
+};
 
 use anyhow::{Result, bail};
 use encoding_rs::SHIFT_JIS;
@@ -11,8 +14,9 @@ use crate::{
         display::{ContextItem, HoverItem, InstructionPart},
     },
     obj::{
-        InstructionArg, InstructionRef, Object, ParsedInstruction, Relocation, RelocationFlags,
-        ResolvedInstructionRef, ResolvedSymbol, Section, Symbol, SymbolFlagSet, SymbolKind,
+        FlowAnalysisResult, InstructionArg, InstructionRef, Object, ParsedInstruction, Relocation,
+        RelocationFlags, ResolvedInstructionRef, ResolvedSymbol, Section, Symbol, SymbolFlagSet,
+        SymbolKind,
     },
     util::ReallySigned,
 };
@@ -31,6 +35,7 @@ pub mod superh;
 pub mod x86;
 
 /// Represents the type of data associated with an instruction
+#[derive(PartialEq)]
 pub enum DataType {
     Int8,
     Int16,
@@ -335,6 +340,17 @@ pub trait Arch: Send + Sync + Debug {
         Vec::new()
     }
 
+    // Perform detailed data flow analysis
+    fn data_flow_analysis(
+        &self,
+        _obj: &Object,
+        _symbol: &Symbol,
+        _code: &[u8],
+        _relocations: &[Relocation],
+    ) -> Option<Box<dyn FlowAnalysisResult>> {
+        None
+    }
+
     fn implcit_addend(
         &self,
         file: &object::File<'_>,