Version v2.0.0-alpha.5

* Initial ARM support

* Disassemble const pool reloc

* Disasm ARM/Thumb/data based on mapping symbols

* Fallback to mapping symbol `$a`

* Support multiple DWARF sequences

* Update line info

* Rework DWARF line info parsing

- Properly handles multiple sections
  in DWARF 1
- line_info moved into ObjSection
- DWARF 2 parser no longer errors with
  no .text section
- Both parsers properly skip empty
  sections

* Simplify line_info (no Option)

* Get line info from section; output formatted ins string

* Unwrap code section in `arm.rs`

* Handle reloc `R_ARM_SBREL32`

* Update ARM disassembler

* Update README.md

* Format

* Revert "Update README.md"

This reverts commit 8bbfcc6f45.

* Update README.md

* Detect ARM version; support ARMv4T and v6K

* Combobox to force ARM version

* Clear LSB in ARM symbol addresses

* Support big-endian ARM ELF files

* Bump `unarm`, `arm-attr`

* Handle ARM implicit addends

* Update README.md

* Explicitly handle all ARM argument types

* Format

* Display more ARM relocs

* Mask LSB on ARM code symbols only

* Read ARM implicit addends

* Format

---------

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

Cargo.toml

@@ -8,7 +8,5 @@ resolver = "2"
 
 [profile.release-lto]
 inherits = "release"
-# Temporarily disabled to fix notify crash
-# See https://github.com/encounter/objdiff/issues/66
-#lto = "thin"
+lto = "thin"
 strip = "debuginfo"

README.md

@@ -17,7 +17,7 @@ Supports:
 - PowerPC 750CL (GameCube, Wii)
 - MIPS (N64, PS1, PS2, PSP)
 - x86 (COFF only at the moment)
-- ARMv5 (DS)
+- ARM (GBA, DS, 3DS)
 
 See [Usage](#usage) for more information.
 

objdiff-cli/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "objdiff-cli"
-version = "2.0.0-alpha.3"
+version = "2.0.0-alpha.5"
 edition = "2021"
 rust-version = "1.70"
 authors = ["Luke Street <luke@street.dev>"]

objdiff-cli/src/cmd/diff.rs

@@ -809,23 +809,29 @@ impl FunctionDiffUi {
 
     fn reload(&mut self) -> Result<()> {
         let prev = self.right_obj.take();
+        let config = diff::DiffObjConfig {
+            relax_reloc_diffs: self.relax_reloc_diffs,
+            space_between_args: true,                // TODO
+            combine_data_sections: false,            // TODO
+            x86_formatter: Default::default(),       // TODO
+            mips_abi: Default::default(),            // TODO
+            mips_instr_category: Default::default(), // TODO
+            arm_arch_version: Default::default(),    // TODO
+        };
         let target = self
             .target_path
             .as_deref()
-            .map(|p| obj::read::read(p).with_context(|| format!("Loading {}", p.display())))
+            .map(|p| {
+                obj::read::read(p, &config).with_context(|| format!("Loading {}", p.display()))
+            })
             .transpose()?;
         let base = self
             .base_path
             .as_deref()
-            .map(|p| obj::read::read(p).with_context(|| format!("Loading {}", p.display())))
+            .map(|p| {
+                obj::read::read(p, &config).with_context(|| format!("Loading {}", p.display()))
+            })
             .transpose()?;
-        let config = diff::DiffObjConfig {
-            relax_reloc_diffs: self.relax_reloc_diffs,
-            space_between_args: true,                // TODO
-            x86_formatter: Default::default(),       // TODO
-            mips_abi: Default::default(),            // TODO
-            mips_instr_category: Default::default(), // TODO
-        };
         let result = diff::diff_objs(&config, target.as_ref(), base.as_ref(), prev.as_ref())?;
 
         let left_sym = target.as_ref().and_then(|o| find_function(o, &self.symbol_name));

objdiff-cli/src/cmd/report.rs

@@ -230,17 +230,21 @@ fn report_object(
         }
         _ => {}
     }
+    let config = diff::DiffObjConfig { relax_reloc_diffs: true, ..Default::default() };
     let target = object
         .target_path
         .as_ref()
-        .map(|p| obj::read::read(p).with_context(|| format!("Failed to open {}", p.display())))
+        .map(|p| {
+            obj::read::read(p, &config).with_context(|| format!("Failed to open {}", p.display()))
+        })
         .transpose()?;
     let base = object
         .base_path
         .as_ref()
-        .map(|p| obj::read::read(p).with_context(|| format!("Failed to open {}", p.display())))
+        .map(|p| {
+            obj::read::read(p, &config).with_context(|| format!("Failed to open {}", p.display()))
+        })
         .transpose()?;
-    let config = diff::DiffObjConfig { relax_reloc_diffs: true, ..Default::default() };
     let result = diff::diff_objs(&config, target.as_ref(), base.as_ref(), None)?;
     let mut unit = ReportUnit {
         name: object.name().to_string(),

objdiff-core/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "objdiff-core"
-version = "2.0.0-alpha.3"
+version = "2.0.0-alpha.5"
 edition = "2021"
 rust-version = "1.70"
 authors = ["Luke Street <luke@street.dev>"]
@@ -19,7 +19,7 @@ dwarf = ["gimli"]
 mips = ["any-arch", "rabbitizer"]
 ppc = ["any-arch", "cwdemangle", "ppc750cl"]
 x86 = ["any-arch", "cpp_demangle", "iced-x86", "msvc-demangler"]
-arm = ["any-arch", "cpp_demangle", "unarm"]
+arm = ["any-arch", "cpp_demangle", "unarm", "arm-attr"]
 
 [dependencies]
 anyhow = "1.0.82"
@@ -56,4 +56,5 @@ iced-x86 = { version = "1.21.0", default-features = false, features = ["std", "d
 msvc-demangler = { version = "0.10.0", optional = true }
 
 # arm
-unarm = { version = "1.0.0", optional = true }
+unarm = { version = "1.3.0", optional = true }
+arm-attr = { version = "0.1.1", optional = true }

objdiff-core/src/arch/arm.rs

@@ -4,9 +4,11 @@ use std::{
 };
 
 use anyhow::{bail, Result};
+use arm_attr::{enums::CpuArch, tag::Tag, BuildAttrs};
 use object::{
-    elf, File, Object, ObjectSection, ObjectSymbol, Relocation, RelocationFlags, SectionIndex,
-    SectionKind, Symbol,
+    elf::{self, SHT_ARM_ATTRIBUTES},
+    Endian, File, Object, ObjectSection, ObjectSymbol, Relocation, RelocationFlags, SectionIndex,
+    SectionKind, Symbol, SymbolKind,
 };
 use unarm::{
     args::{Argument, OffsetImm, OffsetReg, Register},
@@ -16,41 +18,93 @@ use unarm::{
 
 use crate::{
     arch::{ObjArch, ProcessCodeResult},
-    diff::DiffObjConfig,
+    diff::{ArmArchVersion, DiffObjConfig},
     obj::{ObjIns, ObjInsArg, ObjInsArgValue, ObjReloc, ObjSection},
 };
 
 pub struct ObjArchArm {
     /// Maps section index, to list of disasm modes (arm, thumb or data) sorted by address
     disasm_modes: HashMap<SectionIndex, Vec<DisasmMode>>,
+    detected_version: Option<ArmVersion>,
+    endianness: object::Endianness,
 }
 
 impl ObjArchArm {
     pub fn new(file: &File) -> Result<Self> {
+        let endianness = file.endianness();
         match file {
             File::Elf32(_) => {
-                let disasm_modes: HashMap<_, _> = file
-                    .sections()
-                    .filter(|s| s.kind() == SectionKind::Text)
-                    .map(|s| {
-                        let index = s.index();
-                        let mut mapping_symbols: Vec<_> = file
-                            .symbols()
-                            .filter(|s| s.section_index().map(|i| i == index).unwrap_or(false))
-                            .filter_map(|s| DisasmMode::from_symbol(&s))
-                            .collect();
-                        mapping_symbols.sort_unstable_by_key(|x| x.address);
-                        (s.index(), mapping_symbols)
-                    })
-                    .collect();
-                Ok(Self { disasm_modes })
+                let disasm_modes = Self::elf_get_mapping_symbols(file);
+                let detected_version = Self::elf_detect_arm_version(file)?;
+                Ok(Self { disasm_modes, detected_version, endianness })
             }
             _ => bail!("Unsupported file format {:?}", file.format()),
         }
     }
+
+    fn elf_detect_arm_version(file: &File) -> Result<Option<ArmVersion>> {
+        // Check ARM attributes
+        if let Some(arm_attrs) = file.sections().find(|s| {
+            s.kind() == SectionKind::Elf(SHT_ARM_ATTRIBUTES) && s.name() == Ok(".ARM.attributes")
+        }) {
+            let attr_data = arm_attrs.uncompressed_data()?;
+            let build_attrs = BuildAttrs::new(&attr_data, match file.endianness() {
+                object::Endianness::Little => arm_attr::Endian::Little,
+                object::Endianness::Big => arm_attr::Endian::Big,
+            })?;
+            for subsection in build_attrs.subsections() {
+                let subsection = subsection?;
+                if !subsection.is_aeabi() {
+                    continue;
+                }
+                // Only checking first CpuArch tag. Others may exist, but that's very unlikely.
+                let cpu_arch = subsection.into_public_tag_iter()?.find_map(|(_, tag)| {
+                    if let Tag::CpuArch(cpu_arch) = tag {
+                        Some(cpu_arch)
+                    } else {
+                        None
+                    }
+                });
+                match cpu_arch {
+                    Some(CpuArch::V4T) => return Ok(Some(ArmVersion::V4T)),
+                    Some(CpuArch::V5TE) => return Ok(Some(ArmVersion::V5Te)),
+                    Some(CpuArch::V6K) => return Ok(Some(ArmVersion::V6K)),
+                    Some(arch) => bail!("ARM arch {} not supported", arch),
+                    None => {}
+                };
+            }
+        }
+
+        Ok(None)
+    }
+
+    fn elf_get_mapping_symbols(file: &File) -> HashMap<SectionIndex, Vec<DisasmMode>> {
+        file.sections()
+            .filter(|s| s.kind() == SectionKind::Text)
+            .map(|s| {
+                let index = s.index();
+                let mut mapping_symbols: Vec<_> = file
+                    .symbols()
+                    .filter(|s| s.section_index().map(|i| i == index).unwrap_or(false))
+                    .filter_map(|s| DisasmMode::from_symbol(&s))
+                    .collect();
+                mapping_symbols.sort_unstable_by_key(|x| x.address);
+                (s.index(), mapping_symbols)
+            })
+            .collect()
+    }
 }
 
 impl ObjArch for ObjArchArm {
+    fn symbol_address(&self, symbol: &Symbol) -> u64 {
+        let address = symbol.address();
+        if symbol.kind() == SymbolKind::Text {
+            address & !1
+        } else {
+            address
+        }
+    }
+
     fn process_code(
         &self,
         address: u64,
@@ -81,10 +135,21 @@ impl ObjArch for ObjArchArm {
             mapping_symbols.iter().skip(first_mapping_idx + 1).take_while(|x| x.address < end_addr);
         let mut next_mapping = mappings_iter.next();
 
-        let ins_count = code.len() / first_mapping.instruction_size();
+        let ins_count = code.len() / first_mapping.instruction_size(start_addr);
         let mut ops = Vec::<u16>::with_capacity(ins_count);
         let mut insts = Vec::<ObjIns>::with_capacity(ins_count);
-        let mut parser = Parser::new(ArmVersion::V5Te, first_mapping, start_addr, code);
+
+        let version = match config.arm_arch_version {
+            ArmArchVersion::Auto => self.detected_version.unwrap_or(ArmVersion::V5Te),
+            ArmArchVersion::V4T => ArmVersion::V4T,
+            ArmArchVersion::V5TE => ArmVersion::V5Te,
+            ArmArchVersion::V6K => ArmVersion::V6K,
+        };
+        let endian = match self.endianness {
+            object::Endianness::Little => unarm::Endian::Little,
+            object::Endianness::Big => unarm::Endian::Big,
+        };
+        let mut parser = Parser::new(version, first_mapping, start_addr, endian, code);
 
         while let Some((address, op, ins)) = parser.next() {
             if let Some(next) = next_mapping {
@@ -95,7 +160,6 @@ impl ObjArch for ObjArchArm {
                     next_mapping = mappings_iter.next();
                 }
             }
-
             let line = line_info.range(..=address as u64).last().map(|(_, &b)| b);
 
             let reloc = relocations.iter().find(|r| (r.address as u32 & !1) == address).cloned();
@@ -103,11 +167,19 @@ impl ObjArch for ObjArchArm {
             let mut reloc_arg = None;
             if let Some(reloc) = &reloc {
                 match reloc.flags {
+                    // Calls
                     RelocationFlags::Elf { r_type: elf::R_ARM_THM_XPC22 }
-                    | RelocationFlags::Elf { r_type: elf::R_ARM_PC24 } => {
+                    | RelocationFlags::Elf { r_type: elf::R_ARM_THM_PC22 }
+                    | RelocationFlags::Elf { r_type: elf::R_ARM_PC24 }
+                    | RelocationFlags::Elf { r_type: elf::R_ARM_XPC25 }
+                    | RelocationFlags::Elf { r_type: elf::R_ARM_CALL } => {
                         reloc_arg =
                             ins.args.iter().rposition(|a| matches!(a, Argument::BranchDest(_)));
                     }
+                    // Data
+                    RelocationFlags::Elf { r_type: elf::R_ARM_ABS32 } => {
+                        reloc_arg = ins.args.iter().rposition(|a| matches!(a, Argument::UImm(_)));
+                    }
                     _ => (),
                 }
             };
@@ -138,11 +210,42 @@ impl ObjArch for ObjArchArm {
 
     fn implcit_addend(
         &self,
-        _section: &ObjSection,
+        section: &ObjSection,
         address: u64,
         reloc: &Relocation,
     ) -> anyhow::Result<i64> {
-        bail!("Unsupported ARM implicit relocation {:#x}{:?}", address, reloc.flags())
+        let address = address as usize;
+        Ok(match reloc.flags() {
+            // ARM calls
+            RelocationFlags::Elf { r_type: elf::R_ARM_PC24 }
+            | RelocationFlags::Elf { r_type: elf::R_ARM_XPC25 }
+            | RelocationFlags::Elf { r_type: elf::R_ARM_CALL } => {
+                let data = section.data[address..address + 4].try_into()?;
+                let addend = self.endianness.read_i32_bytes(data);
+                let imm24 = addend & 0xffffff;
+                (imm24 << 2) << 8 >> 8
+            }
+
+            // Thumb calls
+            RelocationFlags::Elf { r_type: elf::R_ARM_THM_PC22 }
+            | RelocationFlags::Elf { r_type: elf::R_ARM_THM_XPC22 } => {
+                let data = section.data[address..address + 2].try_into()?;
+                let high = self.endianness.read_i16_bytes(data) as i32;
+                let data = section.data[address + 2..address + 4].try_into()?;
+                let low = self.endianness.read_i16_bytes(data) as i32;
+
+                let imm22 = ((high & 0x7ff) << 11) | (low & 0x7ff);
+                (imm22 << 1) << 9 >> 9
+            }
+
+            // Data
+            RelocationFlags::Elf { r_type: elf::R_ARM_ABS32 } => {
+                let data = section.data[address..address + 4].try_into()?;
+                self.endianness.read_i32_bytes(data)
+            }
+
+            flags => bail!("Unsupported ARM implicit relocation {flags:?}"),
+        } as i64)
     }
 
     fn demangle(&self, name: &str) -> Option<String> {
@@ -209,6 +312,7 @@ fn push_args(
             args.push(ObjInsArg::Reloc);
         } else {
             match arg {
+                Argument::None => {}
                 Argument::Reg(reg) => {
                     if reg.deref {
                         deref = true;
@@ -242,7 +346,7 @@ fn push_args(
                         args.push(ObjInsArg::Arg(ObjInsArgValue::Opaque("^".to_string().into())));
                     }
                 }
-                Argument::UImm(value) | Argument::CoOpcode(value) => {
+                Argument::UImm(value) | Argument::CoOpcode(value) | Argument::SatImm(value) => {
                     args.push(ObjInsArg::PlainText("#".into()));
                     args.push(ObjInsArg::Arg(ObjInsArgValue::Unsigned(*value as u64)));
                 }
@@ -282,7 +386,21 @@ fn push_args(
                         offset.reg.to_string().into(),
                     )));
                 }
-                _ => args.push(ObjInsArg::Arg(ObjInsArgValue::Opaque(arg.to_string().into()))),
+                Argument::CpsrMode(mode) => {
+                    args.push(ObjInsArg::PlainText("#".into()));
+                    args.push(ObjInsArg::Arg(ObjInsArgValue::Unsigned(mode.mode as u64)));
+                    if mode.writeback {
+                        args.push(ObjInsArg::Arg(ObjInsArgValue::Opaque("!".into())));
+                    }
+                }
+                Argument::CoReg(_)
+                | Argument::StatusReg(_)
+                | Argument::StatusMask(_)
+                | Argument::Shift(_)
+                | Argument::CpsrFlags(_)
+                | Argument::Endian(_) => {
+                    args.push(ObjInsArg::Arg(ObjInsArgValue::Opaque(arg.to_string().into())))
+                }
             }
         }
     }

objdiff-core/src/arch/mips.rs

@@ -27,8 +27,8 @@ pub struct ObjArchMips {
 const EF_MIPS_ABI: u32 = 0x0000F000;
 const EF_MIPS_MACH: u32 = 0x00FF0000;
 
-const E_MIPS_MACH_ALLEGREX: u32 = 0x00840000;
-const E_MIPS_MACH_5900: u32 = 0x00920000;
+const EF_MIPS_MACH_ALLEGREX: u32 = 0x00840000;
+const EF_MIPS_MACH_5900: u32 = 0x00920000;
 
 impl ObjArchMips {
     pub fn new(object: &File) -> Result<Self> {
@@ -38,13 +38,19 @@ impl ObjArchMips {
             FileFlags::None => {}
             FileFlags::Elf { e_flags, .. } => {
                 abi = match e_flags & EF_MIPS_ABI {
-                    elf::EF_MIPS_ABI_O32 => Abi::O32,
+                    elf::EF_MIPS_ABI_O32 | elf::EF_MIPS_ABI_O64 => Abi::O32,
                     elf::EF_MIPS_ABI_EABI32 | elf::EF_MIPS_ABI_EABI64 => Abi::N32,
-                    _ => Abi::NUMERIC,
+                    _ => {
+                        if e_flags & elf::EF_MIPS_ABI2 != 0 {
+                            Abi::N32
+                        } else {
+                            Abi::NUMERIC
+                        }
+                    }
                 };
                 instr_category = match e_flags & EF_MIPS_MACH {
-                    E_MIPS_MACH_ALLEGREX => InstrCategory::R4000ALLEGREX,
-                    E_MIPS_MACH_5900 => InstrCategory::R5900,
+                    EF_MIPS_MACH_ALLEGREX => InstrCategory::R4000ALLEGREX,
+                    EF_MIPS_MACH_5900 => InstrCategory::R5900,
                     _ => InstrCategory::CPU,
                 };
             }

objdiff-core/src/arch/mod.rs

@@ -1,7 +1,7 @@
 use std::{borrow::Cow, collections::BTreeMap};
 
 use anyhow::{bail, Result};
-use object::{Architecture, Object, Relocation, RelocationFlags};
+use object::{Architecture, Object, ObjectSymbol, Relocation, RelocationFlags, Symbol};
 
 use crate::{
     diff::DiffObjConfig,
@@ -34,6 +34,8 @@ pub trait ObjArch: Send + Sync {
     fn demangle(&self, _name: &str) -> Option<String> { None }
 
     fn display_reloc(&self, flags: RelocationFlags) -> Cow<'static, str>;
+
+    fn symbol_address(&self, symbol: &Symbol) -> u64 { symbol.address() }
 }
 
 pub struct ProcessCodeResult {

objdiff-core/src/diff/mod.rs

@@ -93,6 +93,30 @@ pub enum MipsInstrCategory {
     R5900,
 }
 
+#[derive(
+    Debug,
+    Copy,
+    Clone,
+    Default,
+    Eq,
+    PartialEq,
+    serde::Deserialize,
+    serde::Serialize,
+    strum::VariantArray,
+    strum::EnumMessage,
+)]
+pub enum ArmArchVersion {
+    #[default]
+    #[strum(message = "Auto (default)")]
+    Auto,
+    #[strum(message = "ARMv4T (GBA)")]
+    V4T,
+    #[strum(message = "ARMv5TE (DS)")]
+    V5TE,
+    #[strum(message = "ARMv6K (3DS)")]
+    V6K,
+}
+
 #[inline]
 const fn default_true() -> bool { true }
 
@@ -102,11 +126,14 @@ pub struct DiffObjConfig {
     pub relax_reloc_diffs: bool,
     #[serde(default = "default_true")]
     pub space_between_args: bool,
+    pub combine_data_sections: bool,
     // x86
     pub x86_formatter: X86Formatter,
     // MIPS
     pub mips_abi: MipsAbi,
     pub mips_instr_category: MipsInstrCategory,
+    // ARM
+    pub arm_arch_version: ArmArchVersion,
 }
 
 impl Default for DiffObjConfig {
@@ -114,9 +141,11 @@ impl Default for DiffObjConfig {
         Self {
             relax_reloc_diffs: false,
             space_between_args: true,
+            combine_data_sections: false,
             x86_formatter: Default::default(),
             mips_abi: Default::default(),
             mips_instr_category: Default::default(),
+            arm_arch_version: Default::default(),
         }
     }
 }

objdiff-core/src/obj/read.rs

@@ -1,4 +1,4 @@
-use std::{fs, io::Cursor, path::Path};
+use std::{collections::HashSet, fs, io::Cursor, path::Path};
 
 use anyhow::{anyhow, bail, ensure, Context, Result};
 use byteorder::{BigEndian, ReadBytesExt};
@@ -11,6 +11,7 @@ use object::{
 
 use crate::{
     arch::{new_arch, ObjArch},
+    diff::DiffObjConfig,
     obj::{
         split_meta::{SplitMeta, SPLITMETA_SECTION},
         ObjInfo, ObjReloc, ObjSection, ObjSectionKind, ObjSymbol, ObjSymbolFlagSet, ObjSymbolFlags,
@@ -54,12 +55,13 @@ fn to_obj_symbol(
     if obj_file.format() == BinaryFormat::Elf && symbol.scope() == SymbolScope::Linkage {
         flags = ObjSymbolFlagSet(flags.0 | ObjSymbolFlags::Hidden);
     }
+    let address = arch.symbol_address(symbol);
     let section_address = if let Some(section) =
         symbol.section_index().and_then(|idx| obj_file.section_by_index(idx).ok())
     {
-        symbol.address() - section.address()
+        address - section.address()
     } else {
-        symbol.address()
+        address
     };
     let demangled_name = arch.demangle(name);
     // Find the virtual address for the symbol if available
@@ -69,7 +71,7 @@ fn to_obj_symbol(
     Ok(ObjSymbol {
         name: name.to_string(),
         demangled_name,
-        address: symbol.address(),
+        address,
         section_address,
         size: symbol.size(),
         size_known: symbol.size() != 0,
@@ -361,7 +363,105 @@ fn line_info(obj_file: &File<'_>, sections: &mut [ObjSection]) -> Result<()> {
     Ok(())
 }
 
-pub fn read(obj_path: &Path) -> Result<ObjInfo> {
+fn update_combined_symbol(symbol: ObjSymbol, address_change: i64) -> Result<ObjSymbol> {
+    Ok(ObjSymbol {
+        name: symbol.name,
+        demangled_name: symbol.demangled_name,
+        address: (symbol.address as i64 + address_change).try_into()?,
+        section_address: (symbol.section_address as i64 + address_change).try_into()?,
+        size: symbol.size,
+        size_known: symbol.size_known,
+        flags: symbol.flags,
+        addend: symbol.addend,
+        virtual_address: if let Some(virtual_address) = symbol.virtual_address {
+            Some((virtual_address as i64 + address_change).try_into()?)
+        } else {
+            None
+        },
+    })
+}
+
+fn combine_sections(section: ObjSection, combine: ObjSection) -> Result<ObjSection> {
+    let mut data = section.data;
+    data.extend(combine.data);
+
+    let address_change: i64 = (section.address + section.size) as i64 - combine.address as i64;
+    let mut symbols = section.symbols;
+    for symbol in combine.symbols {
+        symbols.push(update_combined_symbol(symbol, address_change)?);
+    }
+
+    let mut relocations = section.relocations;
+    for reloc in combine.relocations {
+        relocations.push(ObjReloc {
+            flags: reloc.flags,
+            address: (reloc.address as i64 + address_change).try_into()?,
+            target: reloc.target,                 // TODO: Should be updated?
+            target_section: reloc.target_section, // TODO: Same as above
+        });
+    }
+
+    let mut line_info = section.line_info;
+    for (addr, line) in combine.line_info {
+        let key = (addr as i64 + address_change).try_into()?;
+        line_info.insert(key, line);
+    }
+
+    Ok(ObjSection {
+        name: section.name,
+        kind: section.kind,
+        address: section.address,
+        size: section.size + combine.size,
+        data,
+        orig_index: section.orig_index,
+        symbols,
+        relocations,
+        virtual_address: section.virtual_address,
+        line_info,
+    })
+}
+
+fn combine_data_sections(sections: &mut Vec<ObjSection>) -> Result<()> {
+    let names_to_combine: HashSet<_> = sections
+        .iter()
+        .filter(|s| s.kind == ObjSectionKind::Data)
+        .map(|s| s.name.clone())
+        .collect();
+
+    for name in names_to_combine {
+        // Take section with lowest index
+        let (mut section_index, _) = sections
+            .iter()
+            .enumerate()
+            .filter(|(_, s)| s.name == name)
+            .min_by_key(|(_, s)| s.orig_index)
+            // Should not happen
+            .context("No combine section found with name")?;
+        let mut section = sections.remove(section_index);
+
+        // Remove equally named sections
+        let mut combines = vec![];
+        for i in (0..sections.len()).rev() {
+            if sections[i].name != name || sections[i].orig_index == section.orig_index {
+                continue;
+            }
+            combines.push(sections.remove(i));
+            if i < section_index {
+                section_index -= 1;
+            }
+        }
+
+        // Combine sections ordered by index
+        combines.sort_unstable_by_key(|c| c.orig_index);
+        for combine in combines {
+            section = combine_sections(section, combine)?;
+        }
+        sections.insert(section_index, section);
+    }
+    Ok(())
+}
+
+pub fn read(obj_path: &Path, config: &DiffObjConfig) -> Result<ObjInfo> {
     let (data, timestamp) = {
         let file = fs::File::open(obj_path)?;
         let timestamp = FileTime::from_last_modification_time(&file.metadata()?);
@@ -377,6 +477,9 @@ pub fn read(obj_path: &Path) -> Result<ObjInfo> {
         section.relocations =
             relocations_by_section(arch.as_ref(), &obj_file, section, split_meta.as_ref())?;
     }
+    if config.combine_data_sections {
+        combine_data_sections(&mut sections)?;
+    }
     line_info(&obj_file, &mut sections)?;
     let common = common_symbols(arch.as_ref(), &obj_file, split_meta.as_ref())?;
     Ok(ObjInfo { arch, path: obj_path.to_owned(), timestamp, sections, common, split_meta })

objdiff-gui/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "objdiff-gui"
-version = "2.0.0-alpha.3"
+version = "2.0.0-alpha.5"
 edition = "2021"
 rust-version = "1.70"
 authors = ["Luke Street <luke@street.dev>"]
@@ -19,7 +19,8 @@ path = "src/main.rs"
 
 [features]
 default = ["wgpu", "wsl"]
-wgpu = ["eframe/wgpu"]
+glow = ["eframe/glow"]
+wgpu = ["eframe/wgpu", "dep:wgpu"]
 wsl = []
 
 [dependencies]
@@ -29,7 +30,6 @@ cfg-if = "1.0.0"
 const_format = "0.2.32"
 cwdemangle = "1.0.0"
 dirs = "5.0.1"
-eframe = { version = "0.27.2", features = ["persistence"] }
 egui = "0.27.2"
 egui_extras = "0.27.2"
 filetime = "0.2.23"
@@ -37,7 +37,7 @@ float-ord = "0.3.2"
 font-kit = "0.13.0"
 globset = { version = "0.4.14", features = ["serde1"] }
 log = "0.4.21"
-notify = "6.1.1"
+notify = { git = "https://github.com/encounter/notify", rev = "4c1783e8e041b5f69d4cf1750b9f07e335a0771e" }
 objdiff-core = { path = "../objdiff-core", features = ["all"] }
 png = "0.17.13"
 pollster = "0.3.0"
@@ -50,6 +50,28 @@ strum = { version = "0.26.2", features = ["derive"] }
 tempfile = "3.10.1"
 time = { version = "0.3.36", features = ["formatting", "local-offset"] }
 
+# Keep version in sync with egui
+[dependencies.eframe]
+version = "0.27.2"
+features = [
+    "default_fonts",
+    "persistence",
+    "wayland",
+    "x11",
+]
+default-features = false
+
+# Keep version in sync with eframe
+[dependencies.wgpu]
+version = "0.19.1"
+features = [
+    "dx12",
+    "metal",
+    "webgpu",
+]
+optional = true
+default-features = false
+
 # For Linux static binaries, use rustls
 [target.'cfg(target_os = "linux")'.dependencies]
 reqwest = { version = "0.12.4", default-features = false, features = ["blocking", "json", "multipart", "rustls-tls"] }

objdiff-gui/src/app.rs

@@ -37,6 +37,7 @@ use crate::{
         demangle::{demangle_window, DemangleViewState},
         frame_history::FrameHistory,
         function_diff::function_diff_ui,
+        graphics::{graphics_window, GraphicsConfig, GraphicsViewState},
         jobs::jobs_ui,
         symbol_diff::{symbol_diff_ui, DiffViewState, View},
     },
@@ -48,12 +49,14 @@ pub struct ViewState {
     pub config_state: ConfigViewState,
     pub demangle_state: DemangleViewState,
     pub diff_state: DiffViewState,
+    pub graphics_state: GraphicsViewState,
     pub frame_history: FrameHistory,
     pub show_appearance_config: bool,
     pub show_demangle: bool,
     pub show_project_config: bool,
     pub show_arch_config: bool,
     pub show_debug: bool,
+    pub show_graphics: bool,
 }
 
 /// The configuration for a single object file.
@@ -209,6 +212,7 @@ pub struct App {
     config: AppConfigRef,
     modified: Arc<AtomicBool>,
     watcher: Option<notify::RecommendedWatcher>,
+    app_path: Option<PathBuf>,
     relaunch_path: Rc<Mutex<Option<PathBuf>>>,
     should_relaunch: bool,
 }
@@ -222,6 +226,9 @@ impl App {
         cc: &eframe::CreationContext<'_>,
         utc_offset: UtcOffset,
         relaunch_path: Rc<Mutex<Option<PathBuf>>>,
+        app_path: Option<PathBuf>,
+        graphics_config: GraphicsConfig,
+        graphics_config_path: Option<PathBuf>,
     ) -> Self {
         // Load previous app state (if any).
         // Note that you must enable the `persistence` feature for this to work.
@@ -244,7 +251,32 @@ impl App {
         }
         app.appearance.init_fonts(&cc.egui_ctx);
         app.appearance.utc_offset = utc_offset;
+        app.app_path = app_path;
         app.relaunch_path = relaunch_path;
+        #[cfg(feature = "wgpu")]
+        if let Some(wgpu_render_state) = &cc.wgpu_render_state {
+            use eframe::egui_wgpu::wgpu::Backend;
+            let info = wgpu_render_state.adapter.get_info();
+            app.view_state.graphics_state.active_backend = match info.backend {
+                Backend::Empty => "Unknown",
+                Backend::Vulkan => "Vulkan",
+                Backend::Metal => "Metal",
+                Backend::Dx12 => "DirectX 12",
+                Backend::Gl => "OpenGL",
+                Backend::BrowserWebGpu => "WebGPU",
+            }
+            .to_string();
+            app.view_state.graphics_state.active_device.clone_from(&info.name);
+        }
+        #[cfg(feature = "glow")]
+        if let Some(gl) = &cc.gl {
+            use eframe::glow::HasContext;
+            app.view_state.graphics_state.active_backend = "OpenGL".to_string();
+            app.view_state.graphics_state.active_device =
+                unsafe { gl.get_parameter_string(0x1F01) }; // GL_RENDERER
+        }
+        app.view_state.graphics_state.graphics_config = graphics_config;
+        app.view_state.graphics_state.graphics_config_path = graphics_config_path;
         app
     }
 
@@ -267,8 +299,8 @@ impl App {
                         JobResult::Update(state) => {
                             if let Ok(mut guard) = self.relaunch_path.lock() {
                                 *guard = Some(state.exe_path);
+                                self.should_relaunch = true;
                             }
-                            self.should_relaunch = true;
                         }
                         _ => results.push(result),
                     }
@@ -308,7 +340,7 @@ impl App {
     fn post_update(&mut self, ctx: &egui::Context) {
         self.appearance.post_update(ctx);
 
-        let ViewState { jobs, diff_state, config_state, .. } = &mut self.view_state;
+        let ViewState { jobs, diff_state, config_state, graphics_state, .. } = &mut self.view_state;
         config_state.post_update(ctx, jobs, &self.config);
         diff_state.post_update(ctx, jobs, &self.config);
 
@@ -390,6 +422,15 @@ impl App {
             jobs.push(start_build(ctx, diff_config));
             config.queue_reload = false;
         }
+
+        if graphics_state.should_relaunch {
+            if let Some(app_path) = &self.app_path {
+                if let Ok(mut guard) = self.relaunch_path.lock() {
+                    *guard = Some(app_path.clone());
+                    self.should_relaunch = true;
+                }
+            }
+        }
     }
 }
 
@@ -410,12 +451,14 @@ impl eframe::App for App {
             config_state,
             demangle_state,
             diff_state,
+            graphics_state,
             frame_history,
             show_appearance_config,
             show_demangle,
             show_project_config,
             show_arch_config,
             show_debug,
+            show_graphics,
         } = view_state;
 
         frame_history.on_new_frame(ctx.input(|i| i.time), frame.info().cpu_usage);
@@ -457,6 +500,10 @@ impl eframe::App for App {
                         *show_appearance_config = !*show_appearance_config;
                         ui.close_menu();
                     }
+                    if ui.button("Graphics…").clicked() {
+                        *show_graphics = !*show_graphics;
+                        ui.close_menu();
+                    }
                     if ui.button("Quit").clicked() {
                         ctx.send_viewport_cmd(egui::ViewportCommand::Close);
                     }
@@ -512,6 +559,16 @@ impl eframe::App for App {
                     {
                         config.queue_reload = true;
                     }
+                    if ui
+                        .checkbox(
+                            &mut config.diff_obj_config.combine_data_sections,
+                            "Combine data sections",
+                        )
+                        .on_hover_text("Combines data sections with equal names.")
+                        .changed()
+                    {
+                        config.queue_reload = true;
+                    }
                 });
             });
         });
@@ -543,6 +600,7 @@ impl eframe::App for App {
         demangle_window(ctx, show_demangle, demangle_state, appearance);
         arch_config_window(ctx, config, show_arch_config, appearance);
         debug_window(ctx, show_debug, frame_history, appearance);
+        graphics_window(ctx, show_graphics, frame_history, graphics_state, appearance);
 
         self.post_update(ctx);
     }

objdiff-gui/src/jobs/objdiff.rs

@@ -40,6 +40,7 @@ pub struct BuildConfig {
     pub project_dir: Option<PathBuf>,
     pub custom_make: Option<String>,
     pub custom_args: Option<Vec<String>>,
+    #[allow(unused)]
     pub selected_wsl_distro: Option<String>,
 }
 
@@ -235,7 +236,7 @@ fn run_build(
                     total,
                     &cancel,
                 )?;
-                Some(read::read(target_path).with_context(|| {
+                Some(read::read(target_path, &config.diff_obj_config).with_context(|| {
                     format!("Failed to read object '{}'", target_path.display())
                 })?)
             }
@@ -252,7 +253,7 @@ fn run_build(
                 &cancel,
             )?;
             Some(
-                read::read(base_path)
+                read::read(base_path, &config.diff_obj_config)
                     .with_context(|| format!("Failed to read object '{}'", base_path.display()))?,
             )
         }

objdiff-gui/src/main.rs

@@ -19,6 +19,8 @@ use anyhow::{ensure, Result};
 use cfg_if::cfg_if;
 use time::UtcOffset;
 
+use crate::views::graphics::{load_graphics_config, GraphicsBackend, GraphicsConfig};
+
 fn load_icon() -> Result<egui::IconData> {
     use bytes::Buf;
     let decoder = png::Decoder::new(include_bytes!("../assets/icon_64.png").reader());
@@ -31,6 +33,8 @@ fn load_icon() -> Result<egui::IconData> {
     Ok(egui::IconData { rgba: buf, width: info.width, height: info.height })
 }
 
+const APP_NAME: &str = "objdiff";
+
 // When compiling natively:
 #[cfg(not(target_arch = "wasm32"))]
 fn main() {
@@ -42,6 +46,7 @@ fn main() {
     // https://github.com/time-rs/time/issues/293
     let utc_offset = UtcOffset::current_local_offset().unwrap_or(UtcOffset::UTC);
 
+    let app_path = std::env::current_exe().ok();
     let exec_path: Rc<Mutex<Option<PathBuf>>> = Rc::new(Mutex::new(None));
     let exec_path_clone = exec_path.clone();
     let mut native_options =
@@ -54,14 +59,47 @@ fn main() {
             log::warn!("Failed to load application icon: {}", e);
         }
     }
+    let mut graphics_config = GraphicsConfig::default();
+    let mut graphics_config_path = None;
+    if let Some(storage_dir) = eframe::storage_dir(APP_NAME) {
+        let config_path = storage_dir.join("graphics.ron");
+        match load_graphics_config(&config_path) {
+            Ok(Some(config)) => {
+                graphics_config = config;
+            }
+            Ok(None) => {}
+            Err(e) => {
+                log::error!("Failed to load native config: {:?}", e);
+            }
+        }
+        graphics_config_path = Some(config_path);
+    }
     #[cfg(feature = "wgpu")]
     {
-        native_options.renderer = eframe::Renderer::Wgpu;
+        use eframe::egui_wgpu::wgpu::Backends;
+        if graphics_config.desired_backend.is_supported() {
+            native_options.wgpu_options.supported_backends = match graphics_config.desired_backend {
+                GraphicsBackend::Auto => native_options.wgpu_options.supported_backends,
+                GraphicsBackend::Dx12 => Backends::DX12,
+                GraphicsBackend::Metal => Backends::METAL,
+                GraphicsBackend::Vulkan => Backends::VULKAN,
+                GraphicsBackend::OpenGL => Backends::GL,
+            };
+        }
     }
     eframe::run_native(
-        "objdiff",
+        APP_NAME,
         native_options,
-        Box::new(move |cc| Box::new(app::App::new(cc, utc_offset, exec_path_clone))),
+        Box::new(move |cc| {
+            Box::new(app::App::new(
+                cc,
+                utc_offset,
+                exec_path_clone,
+                app_path,
+                graphics_config,
+                graphics_config_path,
+            ))
+        }),
     )
     .expect("Failed to run eframe application");
 
@@ -77,9 +115,7 @@ fn main() {
                 } else {
                     let result = std::process::Command::new(path)
                         .args(std::env::args())
-                        .spawn()
-                        .unwrap()
-                        .wait();
+                        .spawn();
                     if let Err(e) = result {
                         log::error!("Failed to relaunch: {:?}", e);
                     }

objdiff-gui/src/views/config.rs

@@ -16,7 +16,7 @@ use egui::{
 use globset::Glob;
 use objdiff_core::{
     config::{ProjectObject, DEFAULT_WATCH_PATTERNS},
-    diff::{MipsAbi, MipsInstrCategory, X86Formatter},
+    diff::{ArmArchVersion, MipsAbi, MipsInstrCategory, X86Formatter},
 };
 use self_update::cargo_crate_version;
 use strum::{EnumMessage, VariantArray};
@@ -242,7 +242,7 @@ pub fn config_ui(
                     || {
                         Box::pin(
                             rfd::AsyncFileDialog::new()
-                                .set_directory(&target_dir)
+                                .set_directory(target_dir)
                                 .add_filter("Object file", &["o", "elf", "obj"])
                                 .pick_file(),
                         )
@@ -907,4 +907,22 @@ fn arch_config_ui(ui: &mut egui::Ui, config: &mut AppConfig, _appearance: &Appea
                 }
             }
         });
+    ui.separator();
+    ui.heading("ARM");
+    egui::ComboBox::new("arm_arch_version", "Architecture Version")
+        .selected_text(config.diff_obj_config.arm_arch_version.get_message().unwrap())
+        .show_ui(ui, |ui| {
+            for &version in ArmArchVersion::VARIANTS {
+                if ui
+                    .selectable_label(
+                        config.diff_obj_config.arm_arch_version == version,
+                        version.get_message().unwrap(),
+                    )
+                    .clicked()
+                {
+                    config.diff_obj_config.arm_arch_version = version;
+                    config.queue_reload = true;
+                }
+            }
+        });
 }

objdiff-gui/src/views/debug.rs

@@ -12,6 +12,9 @@ pub fn debug_window(
 }
 
 fn debug_ui(ui: &mut egui::Ui, frame_history: &mut FrameHistory, _appearance: &Appearance) {
+    if ui.button("Clear memory").clicked() {
+        ui.memory_mut(|m| *m = Default::default());
+    }
     ui.label(format!("Repainting the UI each frame. FPS: {:.1}", frame_history.fps()));
     frame_history.ui(ui);
 }

objdiff-gui/src/views/graphics.rs

@@ -0,0 +1,158 @@
+use std::{
+    fs::File,
+    path::{Path, PathBuf},
+};
+
+use anyhow::Result;
+use egui::{text::LayoutJob, Context, FontId, RichText, TextFormat, TextStyle, Window};
+use serde::{Deserialize, Serialize};
+use strum::{EnumIter, EnumMessage, IntoEnumIterator};
+
+use crate::views::{appearance::Appearance, frame_history::FrameHistory};
+
+#[derive(Default)]
+pub struct GraphicsViewState {
+    pub active_backend: String,
+    pub active_device: String,
+    pub graphics_config: GraphicsConfig,
+    pub graphics_config_path: Option<PathBuf>,
+    pub should_relaunch: bool,
+}
+
+#[derive(
+    Copy, Clone, Debug, Default, PartialEq, Eq, EnumIter, EnumMessage, Serialize, Deserialize,
+)]
+pub enum GraphicsBackend {
+    #[default]
+    #[strum(message = "Auto")]
+    Auto,
+    #[strum(message = "Vulkan")]
+    Vulkan,
+    #[strum(message = "Metal")]
+    Metal,
+    #[strum(message = "DirectX 12")]
+    Dx12,
+    #[strum(message = "OpenGL")]
+    OpenGL,
+}
+
+#[derive(Debug, Default, serde::Deserialize, serde::Serialize)]
+pub struct GraphicsConfig {
+    #[serde(default)]
+    pub desired_backend: GraphicsBackend,
+}
+
+pub fn load_graphics_config(path: &Path) -> Result<Option<GraphicsConfig>> {
+    if !path.exists() {
+        return Ok(None);
+    }
+    let file = File::open(path)?;
+    let config: GraphicsConfig = ron::de::from_reader(file)?;
+    Ok(Some(config))
+}
+
+pub fn save_graphics_config(path: &Path, config: &GraphicsConfig) -> Result<()> {
+    let file = File::create(path)?;
+    ron::ser::to_writer(file, config)?;
+    Ok(())
+}
+
+impl GraphicsBackend {
+    pub fn is_supported(&self) -> bool {
+        match self {
+            GraphicsBackend::Auto => true,
+            GraphicsBackend::Vulkan => {
+                cfg!(all(feature = "wgpu", any(target_os = "windows", target_os = "linux")))
+            }
+            GraphicsBackend::Metal => cfg!(all(feature = "wgpu", target_os = "macos")),
+            GraphicsBackend::Dx12 => cfg!(all(feature = "wgpu", target_os = "windows")),
+            GraphicsBackend::OpenGL => true,
+        }
+    }
+}
+
+pub fn graphics_window(
+    ctx: &Context,
+    show: &mut bool,
+    frame_history: &mut FrameHistory,
+    state: &mut GraphicsViewState,
+    appearance: &Appearance,
+) {
+    Window::new("Graphics").open(show).show(ctx, |ui| {
+        ui.label("Graphics backend:");
+        ui.label(
+            RichText::new(&state.active_backend)
+                .color(appearance.emphasized_text_color)
+                .text_style(TextStyle::Monospace),
+        );
+        ui.label("Graphics device:");
+        ui.label(
+            RichText::new(&state.active_device)
+                .color(appearance.emphasized_text_color)
+                .text_style(TextStyle::Monospace),
+        );
+        ui.label(format!("FPS: {:.1}", frame_history.fps()));
+
+        ui.separator();
+        let mut job = LayoutJob::default();
+        job.append(
+            "WARNING: ",
+            0.0,
+            TextFormat::simple(appearance.ui_font.clone(), appearance.delete_color),
+        );
+        job.append(
+            "Changing the graphics backend may cause the application\nto no longer start or display correctly. Use with caution!",
+            0.0,
+            TextFormat::simple(appearance.ui_font.clone(), appearance.emphasized_text_color),
+        );
+        if let Some(config_path) = &state.graphics_config_path {
+            job.append(
+                "\n\nDelete the following file to reset:\n",
+                0.0,
+                TextFormat::simple(appearance.ui_font.clone(), appearance.emphasized_text_color),
+            );
+            job.append(
+                config_path.to_string_lossy().as_ref(),
+                0.0,
+                TextFormat::simple(
+                    FontId {
+                        family: appearance.code_font.family.clone(),
+                        size: appearance.ui_font.size,
+                    },
+                    appearance.emphasized_text_color,
+                ),
+            );
+        }
+        job.append(
+            "\n\nChanging the graphics backend will restart the application.",
+            0.0,
+            TextFormat::simple(appearance.ui_font.clone(), appearance.replace_color),
+        );
+        ui.label(job);
+
+        ui.add_enabled_ui(state.graphics_config_path.is_some(), |ui| {
+            ui.horizontal(|ui| {
+                ui.label("Desired backend:");
+                for backend in GraphicsBackend::iter().filter(GraphicsBackend::is_supported) {
+                    let selected = state.graphics_config.desired_backend == backend;
+                    if ui.selectable_label(selected, backend.get_message().unwrap()).clicked() {
+                        let prev_backend = state.graphics_config.desired_backend;
+                        state.graphics_config.desired_backend = backend;
+                        match save_graphics_config(
+                            state.graphics_config_path.as_ref().unwrap(),
+                            &state.graphics_config,
+                        ) {
+                            Ok(()) => {
+                                state.should_relaunch = true;
+                            }
+                            Err(e) => {
+                                log::error!("Failed to save graphics config: {:?}", e);
+                                state.graphics_config.desired_backend = prev_backend;
+                            }
+                        }
+                    }
+                }
+            });
+        });
+    });
+}

objdiff-gui/src/views/mod.rs

@@ -8,6 +8,7 @@ pub(crate) mod demangle;
 pub(crate) mod file;
 pub(crate) mod frame_history;
 pub(crate) mod function_diff;
+pub(crate) mod graphics;
 pub(crate) mod jobs;
 pub(crate) mod symbol_diff;