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ARM: Fix trailing relocations being ignored when inferring function sizes (#360)

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* ARM: Fix relocations being ignored when inferring function sizes

* ARM: Add test for trailing relocations

* ARM: Fix trailing relocations being cut in half
This commit is contained in:
LagoLunatic
2026-07-10 01:29:51 -04:00
committed by GitHub
parent 2fdba8842e
commit dbabdbff11
6 changed files with 202 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files
objdiff-core/src/arch/arm.rs
+5 -1
View File
@@ -481,9 +481,13 @@ impl Arch for ArchArm {
while next_address >= symbol.address + 2
&& let Some(data) = section.data_range(next_address - 2, 2)
&& data == [0u8; 2]
&& section.relocation_at(next_address - 2, 2).is_none()
{
next_address -= 2;
if let Some(relocation) = section.relocation_at(next_address, 2) {
// Avoid cutting trailing relocations in half.
next_address += self.data_reloc_size(relocation.flags) as u64;
break;
}
}
Ok(next_address.saturating_sub(symbol.address))
}
objdiff-core/src/obj/read.rs
+5 -13
View File
@@ -183,7 +183,6 @@ fn map_symbol(
fn map_symbols(
arch: &dyn Arch,
obj_file: &object::File,
sections: &[Section],
section_indices: &[usize],
split_meta: Option<&SplitMeta>,
config: &DiffObjConfig,
@@ -225,9 +224,6 @@ fn map_symbols(
symbols.push(symbol);
}
// Infer symbol sizes for 0-size symbols
infer_symbol_sizes(arch, &mut symbols, sections)?;
Ok((symbols, symbol_indices))
}
@@ -288,7 +284,7 @@ fn is_local_label(symbol: &Symbol) -> bool {
}
fn infer_symbol_sizes(arch: &dyn Arch, symbols: &mut [Symbol], sections: &[Section]) -> Result<()> {
// Above, we've sorted the symbols by section and then by address.
// Above, we've sorted the symbols by section and then by address, and also mapped section relocations.
// Set symbol sizes based on the next symbol's address
let mut iter_idx = 0;
@@ -1077,15 +1073,11 @@ pub fn parse(data: &[u8], config: &DiffObjConfig, diff_side: DiffSide) -> Result
let split_meta = parse_split_meta(&obj_file)?;
let (mut sections, section_indices) =
map_sections(arch.as_ref(), &obj_file, split_meta.as_ref())?;
let (mut symbols, symbol_indices) = map_symbols(
arch.as_ref(),
&obj_file,
&sections,
&section_indices,
split_meta.as_ref(),
config,
)?;
let (mut symbols, symbol_indices) =
map_symbols(arch.as_ref(), &obj_file, &section_indices, split_meta.as_ref(), config)?;
map_relocations(arch.as_ref(), &obj_file, &mut sections, &section_indices, &symbol_indices)?;
// Infer symbol sizes for 0-size symbols (must be done after map_relocations is called)
infer_symbol_sizes(arch.as_ref(), &mut symbols, &sections)?;
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)?;
objdiff-core/tests/arch_arm.rs
+17
View File
@@ -114,3 +114,20 @@ fn trim_trailing_hword() {
let output = common::display_diff(&obj, &diff, symbol_idx, &diff_config);
insta::assert_snapshot!(output);
}
#[test]
#[cfg(feature = "arm")]
fn do_not_trim_trailing_relocations() {
let diff_config = diff::DiffObjConfig::default();
let obj = obj::read::parse(
include_object!("data/arm/fake_tank.o"),
&diff_config,
diff::DiffSide::Base,
)
.unwrap();
let symbol_idx = obj.symbols.iter().position(|s| s.name == "FakeTankIdleInit").unwrap();
let diff = diff::code::no_diff_code(&obj, symbol_idx, &diff_config).unwrap();
insta::assert_debug_snapshot!(diff.instruction_rows);
let output = common::display_diff(&obj, &diff, symbol_idx, &diff_config);
insta::assert_snapshot!(output);
}
objdiff-core/tests/data/arm/fake_tank.o
BIN
View File
Binary file not shown.
objdiff-core/tests/snapshots/arch_arm__do_not_trim_trailing_relocations-2.snap
+15
View File
@@ -0,0 +1,15 @@
---
source: objdiff-core/tests/arch_arm.rs
expression: output
---
[(Address(0), Dim, 5), (Spacing(4), Normal, 0), (Opcode("ldr", 24), Normal, 10), (Argument(Opaque("r1")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("pc")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(16)), Normal, 0), (Basic("]"), Normal, 0), (Basic(" (->"), Normal, 0), (BranchDest(20), Normal, 0), (Basic(")"), Normal, 0), (Eol, Normal, 0)]
[(Address(2), Dim, 5), (Spacing(4), Normal, 0), (Opcode("mov", 43), Normal, 10), (Argument(Opaque("r3")), Normal, 0), (Basic(", "), Normal, 0), (Argument(Opaque("r1")), Normal, 0), (Eol, Normal, 0)]
[(Address(4), Dim, 5), (Spacing(4), Normal, 0), (Opcode("add", 1), Normal, 10), (Argument(Opaque("r3")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Unsigned(36)), Normal, 0), (Eol, Normal, 0)]
[(Address(6), Dim, 5), (Spacing(4), Normal, 0), (Opcode("mov", 43), Normal, 10), (Argument(Opaque("r2")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Unsigned(0)), Normal, 0), (Eol, Normal, 0)]
[(Address(8), Dim, 5), (Spacing(4), Normal, 0), (Opcode("mov", 43), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Unsigned(2)), Normal, 0), (Eol, Normal, 0)]
[(Address(10), Dim, 5), (Spacing(4), Normal, 0), (Opcode("strb", 117), Normal, 10), (Argument(Opaque("r0")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("r3")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(0)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
[(Address(12), Dim, 5), (Spacing(4), Normal, 0), (Opcode("strb", 117), Normal, 10), (Argument(Opaque("r2")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("r1")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(28)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
[(Address(14), Dim, 5), (Spacing(4), Normal, 0), (Opcode("strh", 124), Normal, 10), (Argument(Opaque("r2")), Normal, 0), (Basic(", "), Normal, 0), (Basic("["), Normal, 0), (Argument(Opaque("r1")), Normal, 0), (Basic(", "), Normal, 0), (Basic("#"), Normal, 0), (Argument(Signed(22)), Normal, 0), (Basic("]"), Normal, 0), (Eol, Normal, 0)]
[(Address(16), Dim, 5), (Spacing(4), Normal, 0), (Opcode("bx", 9), Normal, 10), (Argument(Opaque("lr")), Normal, 0), (Eol, Normal, 0)]
[(Address(18), Dim, 5), (Spacing(4), Normal, 0), (Opcode(".hword", 65534), Normal, 10), (Argument(Unsigned(0)), Normal, 0), (Eol, Normal, 0)]
[(Address(20), Dim, 5), (Spacing(4), Normal, 0), (Opcode(".word", 65534), Normal, 10), (Symbol(Symbol { name: "gCurrentSprite", demangled_name: None, normalized_name: None, address: 0, size: 0, kind: Unknown, section: None, flags: FlagSet(Global), align: None, virtual_address: None }), Bright, 0), (Eol, Normal, 0)]
objdiff-core/tests/snapshots/arch_arm__do_not_trim_trailing_relocations.snap
+160
View File
@@ -0,0 +1,160 @@
---
source: objdiff-core/tests/arch_arm.rs
expression: diff.instruction_rows
---
[
InstructionDiffRow {
ins_ref: Some(
InstructionRef {
address: 176,
size: 2,
opcode: 24,
branch_dest: None,
},
),
kind: None,
branch_from: None,
branch_to: None,
arg_diff: [],
},
InstructionDiffRow {
ins_ref: Some(
InstructionRef {
address: 178,
size: 2,
opcode: 43,
branch_dest: None,
},
),
kind: None,
branch_from: None,
branch_to: None,
arg_diff: [],
},
InstructionDiffRow {
ins_ref: Some(
InstructionRef {
address: 180,
size: 2,
opcode: 1,
branch_dest: None,
},
),
kind: None,
branch_from: None,
branch_to: None,
arg_diff: [],
},
InstructionDiffRow {
ins_ref: Some(
InstructionRef {
address: 182,
size: 2,
opcode: 43,
branch_dest: None,
},
),
kind: None,
branch_from: None,
branch_to: None,
arg_diff: [],
},
InstructionDiffRow {
ins_ref: Some(
InstructionRef {
address: 184,
size: 2,
opcode: 43,
branch_dest: None,
},
),
kind: None,
branch_from: None,
branch_to: None,
arg_diff: [],
},
InstructionDiffRow {
ins_ref: Some(
InstructionRef {
address: 186,
size: 2,
opcode: 117,
branch_dest: None,
},
),
kind: None,
branch_from: None,
branch_to: None,
arg_diff: [],
},
InstructionDiffRow {
ins_ref: Some(
InstructionRef {
address: 188,
size: 2,
opcode: 117,
branch_dest: None,
},
),
kind: None,
branch_from: None,
branch_to: None,
arg_diff: [],
},
InstructionDiffRow {
ins_ref: Some(
InstructionRef {
address: 190,
size: 2,
opcode: 124,
branch_dest: None,
},
),
kind: None,
branch_from: None,
branch_to: None,
arg_diff: [],
},
InstructionDiffRow {
ins_ref: Some(
InstructionRef {
address: 192,
size: 2,
opcode: 9,
branch_dest: None,
},
),
kind: None,
branch_from: None,
branch_to: None,
arg_diff: [],
},
InstructionDiffRow {
ins_ref: Some(
InstructionRef {
address: 194,
size: 2,
opcode: 65534,
branch_dest: None,
},
),
kind: None,
branch_from: None,
branch_to: None,
arg_diff: [],
},
InstructionDiffRow {
ins_ref: Some(
InstructionRef {
address: 196,
size: 4,
opcode: 65534,
branch_dest: None,
},
),
kind: None,
branch_from: None,
branch_to: None,
arg_diff: [],
},
]