Version v3.0.0-beta.10

* 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

.cargo/config.toml

@@ -1,5 +1,4 @@
-[target.x86_64-pc-windows-msvc]
-linker = "rust-lld"
-
-[target.aarch64-pc-windows-msvc]
-linker = "rust-lld"
+# statically link the C runtime so the executable does not depend on
+# that shared/dynamic library.
+[target.'cfg(all(target_env = "msvc", target_os = "windows"))']
+rustflags = ["-C", "target-feature=+crt-static"]

Cargo.lock

@@ -3373,7 +3373,7 @@ dependencies = [
 
 [[package]]
 name = "objdiff-cli"
-version = "3.0.0-beta.7"
+version = "3.0.0-beta.10"
 dependencies = [
  "anyhow",
  "argp",
@@ -3396,7 +3396,7 @@ dependencies = [
 
 [[package]]
 name = "objdiff-core"
-version = "3.0.0-beta.7"
+version = "3.0.0-beta.10"
 dependencies = [
  "anyhow",
  "arm-attr",
@@ -3450,7 +3450,7 @@ dependencies = [
 
 [[package]]
 name = "objdiff-gui"
-version = "3.0.0-beta.7"
+version = "3.0.0-beta.10"
 dependencies = [
  "anyhow",
  "cfg-if",
@@ -3486,7 +3486,7 @@ dependencies = [
 
 [[package]]
 name = "objdiff-wasm"
-version = "3.0.0-beta.7"
+version = "3.0.0-beta.10"
 dependencies = [
  "log",
  "objdiff-core",

Cargo.toml

@@ -14,7 +14,7 @@ strip = "debuginfo"
 codegen-units = 1
 
 [workspace.package]
-version = "3.0.0-beta.7"
+version = "3.0.0-beta.10"
 authors = ["Luke Street <luke@street.dev>"]
 edition = "2024"
 license = "MIT OR Apache-2.0"

README.md

@@ -21,7 +21,7 @@ Supports:
 - MIPS (N64, PS1, PS2, PSP)
 - PowerPC (GameCube, Wii)
 - SuperH (Saturn, Dreamcast)
-- x86 (COFF only)
+- x86, x86_64 (PC)
 
 See [Usage](#usage) for more information.
 

config.schema.json

@@ -175,6 +175,10 @@
           "type": "boolean",
           "description": "If true, objdiff will run the build command with the context file as an argument to generate it.",
           "default": false
+        },
+        "preset_id": {
+          "type": "number",
+          "description": "The decomp.me preset ID to use for the scratch.\nCompiler and flags in the config will take precedence over the preset, but the preset is useful for organizational purposes."
         }
       },
       "required": [

objdiff-cli/src/cmd/report.rs

@@ -245,12 +245,14 @@ fn report_object(
         for (symbol, symbol_diff) in obj.symbols.iter().zip(&obj_diff.symbols) {
             if symbol.section != Some(section_idx)
                 || symbol.size == 0
-                || symbol.flags.contains(SymbolFlag::Hidden | SymbolFlag::Ignored)
+                || symbol.flags.contains(SymbolFlag::Hidden)
+                || symbol.flags.contains(SymbolFlag::Ignored)
             {
                 continue;
             }
             if let Some(existing_functions) = &mut existing_functions {
-                if symbol.flags.contains(SymbolFlag::Global | SymbolFlag::Weak)
+                if (symbol.flags.contains(SymbolFlag::Global)
+                    || symbol.flags.contains(SymbolFlag::Weak))
                     && !existing_functions.insert(symbol.name.clone())
                 {
                     continue;

objdiff-cli/src/views/function_diff.rs

@@ -450,11 +450,11 @@ impl UiView for FunctionDiffUi {
 
     fn reload(&mut self, state: &AppState) -> Result<()> {
         let left_sym =
-            state.left_obj.as_ref().and_then(|(o, _)| find_function(o, &self.symbol_name));
+            state.left_obj.as_ref().and_then(|(o, _)| o.symbol_by_name(&self.symbol_name));
         let right_sym =
-            state.right_obj.as_ref().and_then(|(o, _)| find_function(o, &self.symbol_name));
+            state.right_obj.as_ref().and_then(|(o, _)| o.symbol_by_name(&self.symbol_name));
         let prev_sym =
-            state.prev_obj.as_ref().and_then(|(o, _)| find_function(o, &self.symbol_name));
+            state.prev_obj.as_ref().and_then(|(o, _)| o.symbol_by_name(&self.symbol_name));
         self.num_rows = match (
             get_symbol(state.left_obj.as_ref(), left_sym),
             get_symbol(state.right_obj.as_ref(), right_sym),
@@ -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,
@@ -650,12 +651,3 @@ fn get_symbol(
     let sym = sym?;
     Some((obj, sym, &diff.symbols[sym]))
 }
-
-fn find_function(obj: &Object, name: &str) -> Option<usize> {
-    for (symbol_idx, symbol) in obj.symbols.iter().enumerate() {
-        if symbol.name == name {
-            return Some(symbol_idx);
-        }
-    }
-    None
-}

objdiff-core/Cargo.toml

@@ -41,6 +41,7 @@ any-arch = [
     "dep:regex",
     "dep:similar",
     "dep:syn",
+    "dep:encoding_rs"
 ]
 bindings = [
     "dep:prost",
@@ -171,10 +172,10 @@ notify-debouncer-full = { version = "0.5.0", optional = true }
 shell-escape = { version = "0.1", optional = true }
 tempfile = { version = "3.19", optional = true }
 time = { version = "0.3", optional = true }
-encoding_rs = "0.8.35"
+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/arm.rs

@@ -225,7 +225,7 @@ impl Arch for ArchArm {
 
         let mut address = start_addr;
         while address < end_addr {
-            while let Some(next) = next_mapping.take_if(|x| address >= x.address) {
+            while let Some(next) = next_mapping.filter(|x| address >= x.address) {
                 // Change mapping
                 mode = next.mapping;
                 next_mapping = mappings_iter.next();

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<'_>,

objdiff-core/src/arch/ppc/mod.rs

@@ -1,4 +1,5 @@
 use alloc::{
+    boxed::Box,
     collections::{BTreeMap, BTreeSet},
     string::{String, ToString},
     vec,
@@ -18,11 +19,13 @@ use crate::{
         display::{ContextItem, HoverItem, HoverItemColor, InstructionPart, SymbolNavigationKind},
     },
     obj::{
-        InstructionRef, Object, Relocation, RelocationFlags, ResolvedInstructionRef,
-        ResolvedRelocation, Symbol, SymbolFlag, SymbolFlagSet,
+        FlowAnalysisResult, InstructionRef, Object, Relocation, RelocationFlags,
+        ResolvedInstructionRef, ResolvedRelocation, Symbol, SymbolFlag, SymbolFlagSet,
     },
 };
 
+mod flow_analysis;
+
 // Relative relocation, can be Simm, Offset or BranchDest
 fn is_relative_arg(arg: &ppc750cl::Argument) -> bool {
     matches!(
@@ -157,6 +160,7 @@ impl Arch for ArchPpc {
         Ok(())
     }
 
+    // Could be replaced by data_flow_analysis once that feature stabilizes
     fn generate_pooled_relocations(
         &self,
         address: u64,
@@ -167,6 +171,16 @@ impl Arch for ArchPpc {
         generate_fake_pool_relocations_for_function(address, code, relocations, symbols)
     }
 
+    fn data_flow_analysis(
+        &self,
+        obj: &Object,
+        symbol: &Symbol,
+        code: &[u8],
+        relocations: &[Relocation],
+    ) -> Option<Box<dyn FlowAnalysisResult>> {
+        Some(flow_analysis::ppc_data_flow_analysis(obj, symbol, code, relocations))
+    }
+
     fn implcit_addend(
         &self,
         _file: &object::File<'_>,
@@ -225,7 +239,7 @@ impl Arch for ArchPpc {
             return Some(DataType::String);
         }
         let opcode = ppc750cl::Opcode::from(resolved.ins_ref.opcode as u8);
-        if let Some(ty) = guess_data_type_from_load_store_inst_op(opcode) {
+        if let Some(ty) = flow_analysis::guess_data_type_from_load_store_inst_op(opcode) {
             // Numeric type.
             return Some(ty);
         }
@@ -501,25 +515,6 @@ fn make_symbol_ref(symbol: &object::Symbol) -> Result<ExtabSymbolRef> {
     Ok(ExtabSymbolRef { original_index: symbol.index().0 - 1, name, demangled_name })
 }
 
-fn guess_data_type_from_load_store_inst_op(inst_op: ppc750cl::Opcode) -> Option<DataType> {
-    use ppc750cl::Opcode;
-    match inst_op {
-        Opcode::Lbz | Opcode::Lbzu | Opcode::Lbzux | Opcode::Lbzx => Some(DataType::Int8),
-        Opcode::Lhz | Opcode::Lhzu | Opcode::Lhzux | Opcode::Lhzx => Some(DataType::Int16),
-        Opcode::Lha | Opcode::Lhau | Opcode::Lhaux | Opcode::Lhax => Some(DataType::Int16),
-        Opcode::Lwz | Opcode::Lwzu | Opcode::Lwzux | Opcode::Lwzx => Some(DataType::Int32),
-        Opcode::Lfs | Opcode::Lfsu | Opcode::Lfsux | Opcode::Lfsx => Some(DataType::Float),
-        Opcode::Lfd | Opcode::Lfdu | Opcode::Lfdux | Opcode::Lfdx => Some(DataType::Double),
-
-        Opcode::Stb | Opcode::Stbu | Opcode::Stbux | Opcode::Stbx => Some(DataType::Int8),
-        Opcode::Sth | Opcode::Sthu | Opcode::Sthux | Opcode::Sthx => Some(DataType::Int16),
-        Opcode::Stw | Opcode::Stwu | Opcode::Stwux | Opcode::Stwx => Some(DataType::Int32),
-        Opcode::Stfs | Opcode::Stfsu | Opcode::Stfsux | Opcode::Stfsx => Some(DataType::Float),
-        Opcode::Stfd | Opcode::Stfdu | Opcode::Stfdux | Opcode::Stfdx => Some(DataType::Double),
-        _ => None,
-    }
-}
-
 #[derive(Debug)]
 struct PoolReference {
     addr_src_gpr: ppc750cl::GPR,
@@ -536,7 +531,7 @@ fn get_pool_reference_for_inst(
 ) -> Option<PoolReference> {
     use ppc750cl::{Argument, Opcode};
     let args = &simplified.args;
-    if guess_data_type_from_load_store_inst_op(opcode).is_some() {
+    if flow_analysis::guess_data_type_from_load_store_inst_op(opcode).is_some() {
         match (args[1], args[2]) {
             (Argument::Offset(offset), Argument::GPR(addr_src_gpr)) => {
                 // e.g. lwz. Immediate offset.
@@ -668,7 +663,7 @@ fn make_fake_pool_reloc(
 // and returns a Vec of "fake pool relocations" that simulate what a relocation for that instruction
 // would look like if data hadn't been pooled.
 // This method tries to follow the function's proper control flow. It keeps track of a queue of
-// states it hasn't traversed yet, where each state holds an instruction address and a HashMap of
+// states it hasn't traversed yet, where each state holds an instruction address and a map of
 // which registers hold which pool relocations at that point.
 // When a conditional or unconditional branch is encountered, the destination of the branch is added
 // to the queue. Conditional branches will traverse both the path where the branch is taken and the

objdiff-core/src/arch/x86.rs

@@ -6,7 +6,7 @@ use iced_x86::{
     Decoder, DecoderOptions, DecoratorKind, FormatterOutput, FormatterTextKind, GasFormatter,
     Instruction, IntelFormatter, MasmFormatter, NasmFormatter, NumberKind, OpKind, Register,
 };
-use object::{Endian as _, Object as _, ObjectSection as _, pe};
+use object::{Endian as _, Object as _, ObjectSection as _, elf, pe};
 
 use crate::{
     arch::Arch,
@@ -67,7 +67,11 @@ impl ArchX86 {
                     pe::IMAGE_REL_I386_DIR32 | pe::IMAGE_REL_I386_REL32 => Some(4),
                     _ => None,
                 },
-                _ => None,
+                RelocationFlags::Elf(typ) => match typ {
+                    elf::R_386_32 | elf::R_386_PC32 => Some(4),
+                    elf::R_386_16 => Some(2),
+                    _ => None,
+                },
             },
             Architecture::X86_64 => match flags {
                 RelocationFlags::Coff(typ) => match typ {
@@ -75,7 +79,11 @@ impl ArchX86 {
                     pe::IMAGE_REL_AMD64_ADDR64 => Some(8),
                     _ => None,
                 },
-                _ => None,
+                RelocationFlags::Elf(typ) => match typ {
+                    elf::R_X86_64_PC32 => Some(4),
+                    elf::R_X86_64_64 => Some(8),
+                    _ => None,
+                },
             },
         }
     }
@@ -227,7 +235,8 @@ impl Arch for ArchX86 {
     ) -> Result<i64> {
         match self.arch {
             Architecture::X86 => match flags {
-                RelocationFlags::Coff(pe::IMAGE_REL_I386_DIR32 | pe::IMAGE_REL_I386_REL32) => {
+                RelocationFlags::Coff(pe::IMAGE_REL_I386_DIR32 | pe::IMAGE_REL_I386_REL32)
+                | RelocationFlags::Elf(elf::R_386_32 | elf::R_386_PC32) => {
                     let data =
                         section.data()?[address as usize..address as usize + 4].try_into()?;
                     Ok(self.endianness.read_i32_bytes(data) as i64)
@@ -235,12 +244,14 @@ impl Arch for ArchX86 {
                 flags => bail!("Unsupported x86 implicit relocation {flags:?}"),
             },
             Architecture::X86_64 => match flags {
-                RelocationFlags::Coff(pe::IMAGE_REL_AMD64_ADDR32NB | pe::IMAGE_REL_AMD64_REL32) => {
+                RelocationFlags::Coff(pe::IMAGE_REL_AMD64_ADDR32NB | pe::IMAGE_REL_AMD64_REL32)
+                | RelocationFlags::Elf(elf::R_X86_64_32 | elf::R_X86_64_PC32) => {
                     let data =
                         section.data()?[address as usize..address as usize + 4].try_into()?;
                     Ok(self.endianness.read_i32_bytes(data) as i64)
                 }
-                RelocationFlags::Coff(pe::IMAGE_REL_AMD64_ADDR64) => {
+                RelocationFlags::Coff(pe::IMAGE_REL_AMD64_ADDR64)
+                | RelocationFlags::Elf(elf::R_X86_64_64) => {
                     let data =
                         section.data()?[address as usize..address as usize + 8].try_into()?;
                     Ok(self.endianness.read_i64_bytes(data))

objdiff-core/src/diff/code.rs

@@ -325,12 +325,11 @@ fn reloc_eq(
                     || display_ins_data_literals(left_obj, left_ins)
                         == display_ins_data_literals(right_obj, right_ins))
         }
-        (Some(_), None) => false,
         (None, Some(_)) => {
             // Match if possibly stripped weak symbol
             symbol_name_addend_matches && right_reloc.symbol.flags.contains(SymbolFlag::Weak)
         }
-        (None, None) => symbol_name_addend_matches,
+        (Some(_), None) | (None, None) => symbol_name_addend_matches,
     }
 }
 

objdiff-core/src/diff/data.rs

@@ -53,12 +53,11 @@ fn reloc_eq(
             section_name_eq(left_obj, right_obj, sl, sr)
                 && (symbol_name_addend_matches || address_eq(left, right))
         }
-        (Some(_), None) => false,
         (None, Some(_)) => {
             // Match if possibly stripped weak symbol
             symbol_name_addend_matches && right.symbol.flags.contains(SymbolFlag::Weak)
         }
-        (None, None) => symbol_name_addend_matches,
+        (Some(_), None) | (None, None) => symbol_name_addend_matches,
     }
 }
 

objdiff-core/src/diff/display.rs

@@ -14,8 +14,9 @@ use regex::Regex;
 use crate::{
     diff::{DiffObjConfig, InstructionDiffKind, InstructionDiffRow, ObjectDiff, SymbolDiff},
     obj::{
-        InstructionArg, InstructionArgValue, Object, ParsedInstruction, ResolvedInstructionRef,
-        ResolvedRelocation, SectionFlag, SectionKind, Symbol, SymbolFlag, SymbolKind,
+        FlowAnalysisValue, InstructionArg, InstructionArgValue, Object, ParsedInstruction,
+        ResolvedInstructionRef, ResolvedRelocation, SectionFlag, SectionKind, Symbol, SymbolFlag,
+        SymbolKind,
     },
 };
 
@@ -47,11 +48,12 @@ pub enum DiffText<'a> {
 pub enum DiffTextColor {
     #[default]
     Normal, // Grey
-    Dim,     // Dark grey
-    Bright,  // White
-    Replace, // Blue
-    Delete,  // Red
-    Insert,  // Green
+    Dim,      // Dark grey
+    Bright,   // White
+    DataFlow, // Light blue
+    Replace,  // Blue
+    Delete,   // Red
+    Insert,   // Green
     Rotating(u8),
 }
 
@@ -77,7 +79,7 @@ impl<'a> DiffTextSegment<'a> {
 const EOL_SEGMENT: DiffTextSegment<'static> =
     DiffTextSegment { text: DiffText::Eol, color: DiffTextColor::Normal, pad_to: 0 };
 
-#[derive(Debug, Default, Clone, PartialEq, Eq)]
+#[derive(Debug, Default, Clone)]
 pub enum HighlightKind {
     #[default]
     None,
@@ -186,6 +188,11 @@ 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)
+    } else {
+        None
+    };
     obj.arch.display_instruction(resolved, diff_config, &mut |part| match part {
         InstructionPart::Basic(text) => {
             if text.chars().all(|c| c == ' ') {
@@ -208,15 +215,30 @@ pub fn display_row(
             if arg == InstructionArg::Reloc {
                 displayed_relocation = true;
             }
-            match (arg, resolved.ins_ref.branch_dest) {
-                (InstructionArg::Value(value), _) => cb(DiffTextSegment {
-                    text: DiffText::Argument(value),
-                    color: diff_index
+            let data_flow_value =
+            analysis_result.and_then(|result|
+                result.as_ref().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.
+                (InstructionArg::Value(_) | InstructionArg::Reloc, Some(FlowAnalysisValue::Text(text)), _) => {
+                    cb(DiffTextSegment {
+                        text: DiffText::Argument(InstructionArgValue::Opaque(Cow::Borrowed(text))),
+                        color: DiffTextColor::DataFlow,
+                        pad_to: 0,
+                    })
+                },
+                (InstructionArg::Value(value), None, _) => {
+                    let color = diff_index
                         .get()
-                        .map_or(base_color, |i| DiffTextColor::Rotating(i as u8)),
-                    pad_to: 0,
-                }),
-                (InstructionArg::Reloc, None) => {
+                        .map_or(base_color, |i| DiffTextColor::Rotating(i as u8));
+                    cb(DiffTextSegment {
+                        text: DiffText::Argument(value),
+                        color,
+                        pad_to: 0,
+                    })
+                },
+                (InstructionArg::Reloc, _, None) => {
                     let resolved = resolved.relocation.unwrap();
                     let color = diff_index
                         .get()
@@ -235,9 +257,9 @@ pub fn display_row(
                     }
                     Ok(())
                 }
-                (InstructionArg::BranchDest(dest), _) |
+                (InstructionArg::BranchDest(dest), _, _) |
                 // If the relocation was resolved to a branch destination, emit that instead.
-                (InstructionArg::Reloc, Some(dest))  => {
+                (InstructionArg::Reloc, _, Some(dest))  => {
                     if let Some(addr) = dest.checked_sub(resolved.symbol.address) {
                         cb(DiffTextSegment {
                             text: DiffText::BranchDest(addr),
@@ -288,6 +310,18 @@ pub fn display_row(
     Ok(())
 }
 
+impl PartialEq<HighlightKind> for HighlightKind {
+    fn eq(&self, other: &HighlightKind) -> bool {
+        match (self, other) {
+            (HighlightKind::Opcode(a), HighlightKind::Opcode(b)) => a == b,
+            (HighlightKind::Argument(a), HighlightKind::Argument(b)) => a.loose_eq(b),
+            (HighlightKind::Symbol(a), HighlightKind::Symbol(b)) => a == b,
+            (HighlightKind::Address(a), HighlightKind::Address(b)) => a == b,
+            _ => false,
+        }
+    }
+}
+
 impl PartialEq<DiffText<'_>> for HighlightKind {
     fn eq(&self, other: &DiffText) -> bool {
         match (self, other) {
@@ -604,7 +638,9 @@ fn symbol_matches_filter(
         return false;
     }
     if !show_hidden_symbols
-        && (symbol.size == 0 || symbol.flags.contains(SymbolFlag::Hidden | SymbolFlag::Ignored))
+        && (symbol.size == 0
+            || symbol.flags.contains(SymbolFlag::Hidden)
+            || symbol.flags.contains(SymbolFlag::Ignored))
     {
         return false;
     }

objdiff-core/src/diff/mod.rs

@@ -341,11 +341,25 @@ pub fn diff_objs(
     if let (Some((right_obj, right_out)), Some((left_obj, left_out))) =
         (right.as_mut(), left.as_mut())
     {
-        if let Some(right_name) = &mapping_config.selecting_left {
-            generate_mapping_symbols(right_obj, right_name, left_obj, left_out, diff_config)?;
+        if let Some(right_name) = mapping_config.selecting_left.as_deref() {
+            generate_mapping_symbols(
+                left_obj,
+                left_out,
+                right_obj,
+                right_out,
+                MappingSymbol::Right(right_name),
+                diff_config,
+            )?;
         }
-        if let Some(left_name) = &mapping_config.selecting_right {
-            generate_mapping_symbols(left_obj, left_name, right_obj, right_out, diff_config)?;
+        if let Some(left_name) = mapping_config.selecting_right.as_deref() {
+            generate_mapping_symbols(
+                left_obj,
+                left_out,
+                right_obj,
+                right_out,
+                MappingSymbol::Left(left_name),
+                diff_config,
+            )?;
         }
     }
 
@@ -356,17 +370,28 @@ pub fn diff_objs(
     })
 }
 
+#[derive(Clone, Copy)]
+enum MappingSymbol<'a> {
+    Left(&'a str),
+    Right(&'a str),
+}
+
 /// When we're selecting a symbol to use as a comparison, we'll create comparisons for all
 /// symbols in the other object that match the selected symbol's section and kind. This allows
 /// us to display match percentages for all symbols in the other object that could be selected.
 fn generate_mapping_symbols(
-    base_obj: &Object,
-    base_name: &str,
-    target_obj: &Object,
-    target_out: &mut ObjectDiff,
+    left_obj: &Object,
+    left_out: &mut ObjectDiff,
+    right_obj: &Object,
+    right_out: &mut ObjectDiff,
+    mapping_symbol: MappingSymbol,
     config: &DiffObjConfig,
 ) -> Result<()> {
-    let Some(base_symbol_ref) = symbol_ref_by_name(base_obj, base_name) else {
+    let (base_obj, base_name, target_obj) = match mapping_symbol {
+        MappingSymbol::Left(name) => (left_obj, name, right_obj),
+        MappingSymbol::Right(name) => (right_obj, name, left_obj),
+    };
+    let Some(base_symbol_ref) = base_obj.symbol_by_name(base_name) else {
         return Ok(());
     };
     let base_section_kind = symbol_section_kind(base_obj, &base_obj.symbols[base_symbol_ref]);
@@ -377,32 +402,30 @@ fn generate_mapping_symbols(
         {
             continue;
         }
-        match base_section_kind {
+        let (left_symbol_idx, right_symbol_idx) = match mapping_symbol {
+            MappingSymbol::Left(_) => (base_symbol_ref, target_symbol_index),
+            MappingSymbol::Right(_) => (target_symbol_index, base_symbol_ref),
+        };
+        let (left_diff, right_diff) = match base_section_kind {
             SectionKind::Code => {
-                let (left_diff, _right_diff) =
-                    diff_code(target_obj, base_obj, target_symbol_index, base_symbol_ref, config)?;
-                target_out.mapping_symbols.push(MappingSymbolDiff {
-                    symbol_index: target_symbol_index,
-                    symbol_diff: left_diff,
-                });
+                diff_code(left_obj, right_obj, left_symbol_idx, right_symbol_idx, config)
             }
             SectionKind::Data => {
-                let (left_diff, _right_diff) =
-                    diff_data_symbol(target_obj, base_obj, target_symbol_index, base_symbol_ref)?;
-                target_out.mapping_symbols.push(MappingSymbolDiff {
-                    symbol_index: target_symbol_index,
-                    symbol_diff: left_diff,
-                });
+                diff_data_symbol(left_obj, right_obj, left_symbol_idx, right_symbol_idx)
             }
             SectionKind::Bss | SectionKind::Common => {
-                let (left_diff, _right_diff) =
-                    diff_bss_symbol(target_obj, base_obj, target_symbol_index, base_symbol_ref)?;
-                target_out.mapping_symbols.push(MappingSymbolDiff {
-                    symbol_index: target_symbol_index,
-                    symbol_diff: left_diff,
-                });
+                diff_bss_symbol(left_obj, right_obj, left_symbol_idx, right_symbol_idx)
             }
-            SectionKind::Unknown => {}
+            SectionKind::Unknown => continue,
+        }?;
+        match mapping_symbol {
+            MappingSymbol::Left(_) => right_out.mapping_symbols.push(MappingSymbolDiff {
+                symbol_index: right_symbol_idx,
+                symbol_diff: right_diff,
+            }),
+            MappingSymbol::Right(_) => left_out
+                .mapping_symbols
+                .push(MappingSymbolDiff { symbol_index: left_symbol_idx, symbol_diff: left_diff }),
         }
     }
     Ok(())
@@ -434,10 +457,6 @@ pub struct MappingConfig {
     pub selecting_right: Option<String>,
 }
 
-fn symbol_ref_by_name(obj: &Object, name: &str) -> Option<usize> {
-    obj.symbols.iter().position(|s| s.name == name)
-}
-
 fn apply_symbol_mappings(
     left: &Object,
     right: &Object,
@@ -449,25 +468,25 @@ fn apply_symbol_mappings(
     // If we're selecting a symbol to use as a comparison, mark it as used
     // This ensures that we don't match it to another symbol at any point
     if let Some(left_name) = &mapping_config.selecting_left {
-        if let Some(left_symbol) = symbol_ref_by_name(left, left_name) {
+        if let Some(left_symbol) = left.symbol_by_name(left_name) {
             left_used.insert(left_symbol);
         }
     }
     if let Some(right_name) = &mapping_config.selecting_right {
-        if let Some(right_symbol) = symbol_ref_by_name(right, right_name) {
+        if let Some(right_symbol) = right.symbol_by_name(right_name) {
             right_used.insert(right_symbol);
         }
     }
 
     // Apply manual symbol mappings
     for (left_name, right_name) in &mapping_config.mappings {
-        let Some(left_symbol_index) = symbol_ref_by_name(left, left_name) else {
+        let Some(left_symbol_index) = left.symbol_by_name(left_name) else {
             continue;
         };
         if left_used.contains(&left_symbol_index) {
             continue;
         }
-        let Some(right_symbol_index) = symbol_ref_by_name(right, right_name) else {
+        let Some(right_symbol_index) = right.symbol_by_name(right_name) else {
             continue;
         };
         if right_used.contains(&right_symbol_index) {

objdiff-core/src/obj/mod.rs

@@ -118,7 +118,7 @@ impl Section {
             Err(i) => self
                 .relocations
                 .get(i)
-                .take_if(|r| r.address < ins_ref.address + ins_ref.size as u64),
+                .filter(|r| r.address < ins_ref.address + ins_ref.size as u64),
         }
         .and_then(|relocation| {
             let symbol = obj.symbols.get(relocation.target_symbol)?;
@@ -233,6 +233,19 @@ pub enum SymbolKind {
     Section,
 }
 
+#[derive(Debug)]
+pub enum FlowAnalysisValue {
+    Text(String),
+}
+
+pub trait FlowAnalysisResult: core::fmt::Debug + Send {
+    fn get_argument_value_at_address(
+        &self,
+        address: u64,
+        argument: u8,
+    ) -> Option<&FlowAnalysisValue>;
+}
+
 #[derive(Debug, Clone, Eq, PartialEq, Hash, Default)]
 pub struct Symbol {
     pub name: String,
@@ -260,6 +273,7 @@ pub struct Object {
     pub path: Option<std::path::PathBuf>,
     #[cfg(feature = "std")]
     pub timestamp: Option<filetime::FileTime>,
+    pub flow_analysis_results: BTreeMap<u64, Box<dyn FlowAnalysisResult>>,
 }
 
 impl Default for Object {
@@ -274,6 +288,7 @@ impl Default for Object {
             path: None,
             #[cfg(feature = "std")]
             timestamp: None,
+            flow_analysis_results: BTreeMap::<u64, Box<dyn FlowAnalysisResult>>::new(),
         }
     }
 }
@@ -308,6 +323,12 @@ impl Object {
         let offset = symbol.address.checked_sub(section.address)?;
         section.data.get(offset as usize..offset as usize + symbol.size as usize)
     }
+
+    pub fn symbol_by_name(&self, name: &str) -> Option<usize> {
+        self.symbols.iter().position(|symbol| symbol.section.is_some() && symbol.name == name)
+    }
+
+    pub fn has_flow_analysis_result(&self) -> bool { !self.flow_analysis_results.is_empty() }
 }
 
 #[derive(Debug, Clone, Eq, PartialEq, Hash)]

objdiff-core/src/obj/read.rs

@@ -121,6 +121,15 @@ fn map_symbols(
     Ok((symbols, symbol_indices))
 }
 
+/// When inferring a symbol's size, we ignore symbols that start with specific prefixes. They are
+/// usually emitted as branch targets and do not represent the start of a function or object.
+fn is_local_label(symbol: &Symbol) -> bool {
+    const LABEL_PREFIXES: &[&str] = &[".L", "LAB_"];
+    symbol.size == 0
+        && symbol.flags.contains(SymbolFlag::Local)
+        && LABEL_PREFIXES.iter().any(|p| symbol.name.starts_with(p))
+}
+
 fn infer_symbol_sizes(symbols: &mut [Symbol], sections: &[Section]) {
     // Create a sorted list of symbol indices by section
     let mut symbols_with_section = Vec::<usize>::with_capacity(symbols.len());
@@ -167,27 +176,28 @@ fn infer_symbol_sizes(symbols: &mut [Symbol], sections: &[Section]) {
         if last_end.0 == section_idx && last_end.1 > symbol.address {
             continue;
         }
-        let next_symbol = match symbol.kind {
-            // For function/object symbols, find the next function/object symbol (in other words:
-            // skip over labels)
-            SymbolKind::Function | SymbolKind::Object => loop {
-                if iter_idx >= symbols_with_section.len() {
-                    break None;
+        let next_symbol = loop {
+            if iter_idx >= symbols_with_section.len() {
+                break None;
+            }
+            let next_symbol = &symbols[symbols_with_section[iter_idx]];
+            if next_symbol.section != Some(section_idx) {
+                break None;
+            }
+            if match symbol.kind {
+                SymbolKind::Function | SymbolKind::Object => {
+                    // For function/object symbols, find the next function/object
+                    matches!(next_symbol.kind, SymbolKind::Function | SymbolKind::Object)
                 }
-                let next_symbol = &symbols[symbols_with_section[iter_idx]];
-                if next_symbol.section != Some(section_idx) {
-                    break None;
+                SymbolKind::Unknown | SymbolKind::Section => {
+                    // For labels (or anything else), stop at any symbol
+                    true
                 }
-                if let SymbolKind::Function | SymbolKind::Object = next_symbol.kind {
-                    break Some(next_symbol);
-                }
-                iter_idx += 1;
-            },
-            // For labels (or anything else), simply use the next symbol's address
-            SymbolKind::Unknown | SymbolKind::Section => symbols_with_section
-                .get(iter_idx)
-                .map(|&i| &symbols[i])
-                .take_if(|s| s.section == Some(section_idx)),
+            } && !is_local_label(next_symbol)
+            {
+                break Some(next_symbol);
+            }
+            iter_idx += 1;
         };
         let next_address = next_symbol.map(|s| s.address).unwrap_or_else(|| {
             let section = &sections[section_idx];
@@ -341,7 +351,7 @@ fn map_section_relocations(
                 let idx = if let Some(section_symbol) = obj_file
                     .symbol_by_index(idx)
                     .ok()
-                    .take_if(|s| s.kind() == object::SymbolKind::Section)
+                    .filter(|s| s.kind() == object::SymbolKind::Section)
                 {
                     let section_index =
                         section_symbol.section_index().context("Section symbol without section")?;
@@ -422,17 +432,18 @@ fn map_relocations(
     Ok(())
 }
 
-fn calculate_pooled_relocations(
-    arch: &dyn Arch,
-    sections: &mut [Section],
-    symbols: &[Symbol],
-) -> Result<()> {
-    for (section_index, section) in sections.iter_mut().enumerate() {
+fn perform_data_flow_analysis(obj: &mut Object, config: &DiffObjConfig) -> Result<()> {
+    // If neither of these settings are on, no flow analysis to perform
+    if !config.analyze_data_flow && !config.ppc_calculate_pool_relocations {
+        return Ok(());
+    }
+
+    let mut generated_relocations = Vec::<(usize, Vec<Relocation>)>::new();
+    for (section_index, section) in obj.sections.iter().enumerate() {
         if section.kind != SectionKind::Code {
             continue;
         }
-        let mut fake_pool_relocs = Vec::new();
-        for symbol in symbols {
+        for symbol in obj.symbols.iter() {
             if symbol.section != Some(section_index) {
                 continue;
             }
@@ -447,14 +458,32 @@ fn calculate_pooled_relocations(
                         symbol.address + symbol.size
                     )
                 })?;
-            fake_pool_relocs.append(&mut arch.generate_pooled_relocations(
-                symbol.address,
-                code,
-                &section.relocations,
-                symbols,
-            ));
+
+            // Optional pooled relocation computation
+            // Long view: This could be replaced by the full data flow analysis
+            // once that feature has stabilized.
+            if config.ppc_calculate_pool_relocations {
+                let relocations = obj.arch.generate_pooled_relocations(
+                    symbol.address,
+                    code,
+                    &section.relocations,
+                    &obj.symbols,
+                );
+                generated_relocations.push((section_index, relocations));
+            }
+
+            // 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),
+                );
+            }
         }
-        section.relocations.append(&mut fake_pool_relocs);
+    }
+    for (section_index, mut relocations) in generated_relocations {
+        obj.sections[section_index].relocations.append(&mut relocations);
+    }
+    for section in obj.sections.iter_mut() {
         section.relocations.sort_by_key(|r| r.address);
     }
     Ok(())
@@ -855,15 +884,12 @@ pub fn parse(data: &[u8], config: &DiffObjConfig) -> Result<Object> {
     let (mut symbols, symbol_indices) =
         map_symbols(arch.as_ref(), &obj_file, &sections, &section_indices, split_meta.as_ref())?;
     map_relocations(arch.as_ref(), &obj_file, &mut sections, &section_indices, &symbol_indices)?;
-    if config.ppc_calculate_pool_relocations {
-        calculate_pooled_relocations(arch.as_ref(), &mut sections, &symbols)?;
-    }
     parse_line_info(&obj_file, &mut sections, &section_indices, data)?;
     if config.combine_data_sections || config.combine_text_sections {
         combine_sections(&mut sections, &mut symbols, config)?;
     }
     arch.post_init(&sections, &symbols);
-    Ok(Object {
+    let mut obj = Object {
         arch,
         endianness: obj_file.endianness(),
         symbols,
@@ -873,7 +899,14 @@ pub fn parse(data: &[u8], config: &DiffObjConfig) -> Result<Object> {
         path: None,
         #[cfg(feature = "std")]
         timestamp: None,
-    })
+        flow_analysis_results: Default::default(),
+    };
+
+    // Need to construct the obj first so that we have a convinient package to
+    // pass to flow analysis. Then the flow analysis will mutate obj adding
+    // additional data to it.
+    perform_data_flow_analysis(&mut obj, config)?;
+    Ok(obj)
 }
 
 #[cfg(feature = "std")]