Author: royitaqi Date: 2025-06-04T17:07:07-07:00 New Revision: d4d2f069dec4fb8b13447f52752d4ecd08d976d6
URL: https://github.com/llvm/llvm-project/commit/d4d2f069dec4fb8b13447f52752d4ecd08d976d6 DIFF: https://github.com/llvm/llvm-project/commit/d4d2f069dec4fb8b13447f52752d4ecd08d976d6.diff LOG: [lldb] Set default object format to `MachO` in `ObjectFileMachO` (#142704) # The Change This patch sets the **default** object format of `ObjectFileMachO` to be `MachO` (instead of what currently ends up to be `ELF`, see below). This should be **the correct thing to do**, because the code before the line of change has already verified the Mach-O header. The existing logic: * In `ObjectFileMachO`, the object format is unassigned by default. So it's `UnknownObjectFormat` (see [code](https://github.com/llvm/llvm-project/blob/54d544b83141dc0b20727673f68793728ed54793/llvm/lib/TargetParser/Triple.cpp#L1024)). * The code then looks at load commands like `LC_VERSION_MIN_*` ([code](https://github.com/llvm/llvm-project/blob/54d544b83141dc0b20727673f68793728ed54793/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp#L5180-L5217)) and `LC_BUILD_VERSION` ([code](https://github.com/llvm/llvm-project/blob/54d544b83141dc0b20727673f68793728ed54793/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp#L5231-L5252)) and assign the Triple's OS and Environment if they exist. * If the above sets the Triple's OS to macOS, then the object format defaults to `MachO`; otherwise it is `ELF` ([code](https://github.com/llvm/llvm-project/blob/54d544b83141dc0b20727673f68793728ed54793/llvm/lib/TargetParser/Triple.cpp#L936-L937)) # Impact For **production usage** where Mach-O files have the said load commands (which is [expected](https://www.google.com/search?q=Are+mach-o+files+expected+to+have+the+LC_BUILD_VERSION+load+command%3F)), this patch won't change anything. * **Important note**: It's not clear if there are legitimate production use cases where the Mach-O files don't have said load commands. If there is, the exiting code think they are `ELF`. This patch changes it to `MachO`. This is considered a fix for such files. For **unit tests**, this patch will simplify the yaml data by not requiring the said load commands. # Test See PR. Added: Modified: lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp lldb/unittests/ObjectFile/MachO/TestObjectFileMachO.cpp Removed: ################################################################################ diff --git a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp index 3950454b7c90e..0079672c5cbd0 100644 --- a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp +++ b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.cpp @@ -5148,6 +5148,7 @@ void ObjectFileMachO::GetAllArchSpecs(const llvm::MachO::mach_header &header, llvm::Triple base_triple = base_arch.GetTriple(); base_triple.setOS(llvm::Triple::UnknownOS); base_triple.setOSName(llvm::StringRef()); + base_triple.setObjectFormat(llvm::Triple::MachO); if (header.filetype == MH_PRELOAD) { if (header.cputype == CPU_TYPE_ARM) { diff --git a/lldb/unittests/ObjectFile/MachO/TestObjectFileMachO.cpp b/lldb/unittests/ObjectFile/MachO/TestObjectFileMachO.cpp index 0ef2d0b85fd36..71ff866abb352 100644 --- a/lldb/unittests/ObjectFile/MachO/TestObjectFileMachO.cpp +++ b/lldb/unittests/ObjectFile/MachO/TestObjectFileMachO.cpp @@ -94,4 +94,59 @@ TEST_F(ObjectFileMachOTest, IndirectSymbolsInTheSharedCache) { for (size_t i = 0; i < 10; i++) OF->ParseSymtab(symtab); } + +TEST_F(ObjectFileMachOTest, ObjectFormatWithoutVersionLoadCommand) { + // A Mach-O file without the load command LC_BUILD_VERSION. + const char *yamldata = R"( +--- !mach-o +FileHeader: + magic: 0xFEEDFACF + cputype: 0x0100000C + cpusubtype: 0x00000000 + filetype: 0x00000001 + ncmds: 1 + sizeofcmds: 152 + flags: 0x00002000 + reserved: 0x00000000 +LoadCommands: + - cmd: LC_SEGMENT_64 + cmdsize: 152 + segname: __TEXT + vmaddr: 0 + vmsize: 4 + fileoff: 184 + filesize: 4 + maxprot: 7 + initprot: 7 + nsects: 1 + flags: 0 + Sections: + - sectname: __text + segname: __TEXT + addr: 0x0000000000000000 + content: 'AABBCCDD' + size: 4 + offset: 184 + align: 0 + reloff: 0x00000000 + nreloc: 0 + flags: 0x80000400 + reserved1: 0x00000000 + reserved2: 0x00000000 + reserved3: 0x00000000 +... +)"; + + // Perform setup. + llvm::Expected<TestFile> file = TestFile::fromYaml(yamldata); + EXPECT_THAT_EXPECTED(file, llvm::Succeeded()); + auto module_sp = std::make_shared<Module>(file->moduleSpec()); + ASSERT_NE(module_sp, nullptr); + auto object_file = module_sp->GetObjectFile(); + ASSERT_NE(object_file, nullptr); + + // Verify that the object file is recognized as Mach-O. + ASSERT_EQ(object_file->GetArchitecture().GetTriple().getObjectFormat(), + llvm::Triple::MachO); +} #endif _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
