shylie/llvm-project
1
0
Fork 0
Code Issues Pull Requests Actions 6 Packages Projects Releases Wiki Activity

[lldb] Fix section offset of synthesized entry point symbol (#190348)

Browse Source 
In the non-ARM case, the offset was left unset, so the symbol
synthesized for the entry point pointed to the start of the containing
section.
As a drive-by change, simplify offset adjustment in ARM case.
This commit is contained in:
Sergei Barannikov 2026-04-05 21:39:24 +03:00 committed by GitHub
parent 353ab41001
commit f8e394b6f8
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
2 changed files with 40 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
lldb/source/Plugins/ObjectFile/ELF/ObjectFileELF.cpp
View File

@ -3331,7 +3331,7 @@ void ObjectFileELF::ParseSymtab(Symtab &lldb_symtab) {
/*is_trampoline=*/false,
/*is_artificial=*/true,
/*section_sp=*/section_sp,
/*offset=*/0,
/*offset=*/entry_point_addr.GetOffset(),
/*size=*/0, // FDE can span multiple symbols so don't use its size.
/*size_is_valid=*/false,
/*contains_linker_annotations=*/false,
@ -3342,8 +3342,8 @@ void ObjectFileELF::ParseSymtab(Symtab &lldb_symtab) {
// address.
if (arch.GetMachine() == llvm::Triple::arm &&
(entry_point_file_addr & 1)) {
symbol.GetAddressRef().SetOffset(entry_point_addr.GetOffset() ^ 1);
m_address_class_map[entry_point_file_addr ^ 1] =
symbol.GetAddressRef().Slide(-1);
m_address_class_map[entry_point_file_addr - 1] =
AddressClass::eCodeAlternateISA;
} else {
m_address_class_map[entry_point_file_addr] = AddressClass::eCode;

37
lldb/unittests/ObjectFile/ELF/TestObjectFileELF.cpp
View File

@ -191,6 +191,43 @@ TEST_F(ObjectFileELFTest, GetModuleSpecifications_OffsetSizeWithOffsetFile) {
EXPECT_EQ(FileSystem::Instance().GetByteSize(FileSpec(SO)), 4640UL);
}
TEST_F(ObjectFileELFTest, GetSymtab_SynthesizedEntryPointSymbol) {
auto ExpectedFile = TestFile::fromYaml(R"(
--- !ELF
FileHeader:
Class: ELFCLASS32
Data: ELFDATA2LSB
Type: ET_EXEC
Machine: EM_SPARC
Entry: 0x0000000000000042
Sections:
- Name: .text
Type: SHT_PROGBITS
Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
Address: 0x0000000000000020
Size: 0x0000000000000040
...
)");
ASSERT_THAT_EXPECTED(ExpectedFile, llvm::Succeeded());
auto module_sp = std::make_shared<Module>(ExpectedFile->moduleSpec());
Symtab *symtab = module_sp->GetSymtab();
ASSERT_NE(symtab, nullptr);
// Check that the entry point symbol was synthesized.
Symbol *entry_sym = symtab->FindSymbolAtFileAddress(0x42);
ASSERT_TRUE(entry_sym);
EXPECT_TRUE(entry_sym->IsSyntheticWithAutoGeneratedName());
// Check that the symbol has the correct section+offset address.
ASSERT_TRUE(entry_sym->ValueIsAddress());
Address entry_sym_addr = entry_sym->GetAddress();
ASSERT_TRUE(entry_sym_addr.IsSectionOffset());
EXPECT_EQ(entry_sym_addr.GetSection()->GetName(), ".text");
EXPECT_EQ(entry_sym_addr.GetOffset(), 0x42U - 0x20U);
}
TEST_F(ObjectFileELFTest, GetSymtab_NoSymEntryPointArmThumbAddressClass) {
/*
// nosym-entrypoint-arm-thumb.s