LLVM-READOBJ(1)

📦
version 20.1.8 · 8 versions
, in fedora 43, fedora 44

💖 LLVM-READOBJ 💖

okay bestie, welcome to the llvm-readobj page, section 1 of the LLVM manual 🫶 this is the tool that spills ALL the tea about what's actually inside your object files, at the lowest, nerdiest, most format-specific level. no cap.

✨ NAME ✨

llvm-readobj — LLVM Object Reader. she reads objects. that's it. that's the job. 👑

✨ SYNOPSIS ✨

llvm-readobj [options] [input...]

✨ DESCRIPTION ✨

The llvm-readobj tool displays low-level format-specific information about one or more object files. like, the guts guts. 💅

If input is -, llvm-readobj reads from standard input. Otherwise, it will read from the specified filenames.

✨ DIFFERENCES TO LLVM-READELF ✨

so llvm-readelf is literally just an alias for the llvm-readobj tool, but with a slightly different command-line interface and output that is GNU compatible. here's the rundown of how the two sisters differ, bestie:

  • llvm-readelf uses GNU for the --elf-output-style option by default. llvm-readobj uses LLVM.
  • llvm-readelf allows single-letter grouped flags (e.g. llvm-readelf -SW is the same as llvm-readelf -S -W). llvm-readobj does not allow grouping. grouping is a readelf-only slay, sorry.
  • llvm-readelf provides -s as an alias for --symbols, for GNU readelf compatibility, whereas it is an alias for --section-headers in llvm-readobj. yeah. the same letter means two different things. iconic but also chaotic 😭
  • llvm-readobj provides -t as an alias for --symbols. llvm-readelf does not.
  • llvm-readobj provides --sr, --sd, --st and --dt as aliases for --section-relocations, --section-data, --section-symbols and --dyn-symbols respectively. llvm-readelf does not provide these aliases, to avoid conflicting with grouped flags. makes sense honestly.

✨ GENERAL AND MULTI-FORMAT OPTIONS ✨

These options are applicable to more than one file format, or are unrelated to file formats. the universal besties. 🌈

  • --all — Equivalent to specifying all the main display options relevant to the file format. go big or go home.
  • --addrsig — Display the address-significance table.
  • --decompress, -z — Dump decompressed section content when used with -x or -p. If the section(s) are not compressed, they are displayed as is. no unzipping required, they're already serving.
  • --demangle, -C — Display demangled symbol names in the output. This option is only for ELF and XCOFF file formats.
  • --expand-relocs — When used with --relocs, display each relocation in an expanded multi-line format. room to breathe ✨
  • --file-header, -h — Display file headers.
  • --headers, -e — Equivalent to setting: --file-header, --program-headers, and --sections. the combo meal.
  • --help — Display a summary of command line options.
  • --hex-dump=<section[,section,...]>, -x — Display the specified section(s) as hexadecimal bytes. section may be a section index or section name.
  • --memtag — Display information about memory tagging present in the binary. This includes various memtag-specific dynamic entries, decoded global descriptor sections, and decoded Android-specific ELF notes.
  • --needed-libs — Display the needed libraries.
  • --no-demangle — Do not demangle symbol names in the output. This option is only for ELF and XCOFF file formats. The option is enabled by default.
  • --relocations, --relocs, -r — Display the relocation entries in the file.
  • --sections, --section-headers, -S — Display all sections.
  • --section-data, --sd — When used with --sections, display section data for each section shown. This option has no effect for GNU style output.
  • --section-relocations, --sr — When used with --sections, display relocations for each section shown. This option has no effect for GNU style output.
  • --section-symbols, --st — When used with --sections, display symbols for each section shown. This option has no effect for GNU style output.
  • --sort-symbols=<sort_key[,sort_key]> — Specify the keys to sort symbols before displaying symtab. Valid values for sort_key are name and type.
  • --stackmap — Display contents of the stackmap section.
  • --string-dump=<section[,section,...]>, -p — Display the specified section(s) as a list of strings. section may be a section index or section name.
  • --string-table — Display contents of the string table.
  • --symbols, --syms, -s — Display the symbol table.
  • --unwind, -u — Display unwind information.
  • --version — Display the version of the llvm-readobj executable.
  • @<FILE> — Read command-line options from response file <FILE>.

✨ ELF SPECIFIC OPTIONS ✨

The following options are implemented only for the ELF file format. ELF girlies, this is your moment 🧚

  • --arch-specific, -A — Display architecture-specific information, e.g. the ARM attributes section on ARM.
  • --bb-addr-map — Display the contents of the basic block address map section(s), which contain the address of each function, along with the relative offset of each basic block. When pgo analysis maps are present, all analyses are printed as their raw value.
  • --pretty-pgo-analysis-map — When pgo analysis maps are present in the basic block address map section(s), analyses with special formats (i.e. BlockFrequency, BranchProbability, etc) are printed using the same format as their respective analysis pass. Requires --bb-addr-map to have an effect. no --bb-addr-map, no glamour. 💅
  • --dependent-libraries — Display the dependent libraries section.
  • --dyn-relocations — Display the dynamic relocation entries.
  • --dyn-symbols, --dyn-syms, --dt — Display the dynamic symbol table.
  • --dynamic-table, --dynamic, -d — Display the dynamic table.
  • --cg-profile — Display the callgraph profile section.
  • --histogram, -I — Display a bucket list histogram for dynamic symbol hash tables.
  • --elf-linker-options — Display the linker options section.
  • --elf-output-style=<value> — Format ELF information in the specified style. Valid options are LLVM, GNU, and JSON. LLVM output (the default) is an expanded and structured format. GNU output mimics the equivalent GNU readelf output. JSON is JSON formatted output intended for machine consumption.
  • --section-groups, -g — Display section groups.
  • --gnu-hash-table — Display the GNU hash table for dynamic symbols.
  • --hash-symbols — Display the expanded hash table with dynamic symbol data.
  • --hash-table — Display the hash table for dynamic symbols.
  • --memtag — Display information about memory tagging present in the binary. This includes various dynamic entries, decoded global descriptor sections, and decoded Android-specific ELF notes.
  • --notes, -n — Display all notes.
  • --pretty-print — When used with --elf-output-style, JSON output will be formatted in a more readable format.
  • --program-headers, --segments, -l — Display the program headers.
  • --section-mapping — Display the section to segment mapping.
  • --stack-sizes — Display the contents of the stack sizes section(s), i.e. pairs of function names and the size of their stack frames. Currently only implemented for GNU style output.
  • --version-info, -V — Display version sections.

✨ MACH-O SPECIFIC OPTIONS ✨

The following options are implemented only for the Mach-O file format. apple hive rise up 🍓

  • --macho-data-in-code — Display the Data in Code command.
  • --macho-dsymtab — Display the Dsymtab command.
  • --macho-indirect-symbols — Display indirect symbols.
  • --macho-linker-options — Display the Mach-O-specific linker options.
  • --macho-segment — Display the Segment command.
  • --macho-version-min — Display the version min command.

✨ PE/COFF SPECIFIC OPTIONS ✨

The following options are implemented only for the PE/COFF file format. windows besties, this one's for you 💜

  • --codeview — Display CodeView debug information.
  • --codeview-ghash — Enable global hashing for CodeView type stream de-duplication.
  • --codeview-merged-types — Display the merged CodeView type stream.
  • --codeview-subsection-bytes — Dump raw contents of CodeView debug sections and records.
  • --coff-basereloc — Display the .reloc section.
  • --coff-debug-directory — Display the debug directory.
  • --coff-tls-directory — Display the TLS directory.
  • --coff-directives — Display the .drectve section.
  • --coff-exports — Display the export table.
  • --coff-imports — Display the import table.
  • --coff-load-config — Display the load config.
  • --coff-resources — Display the .rsrc section.

✨ XCOFF SPECIFIC OPTIONS ✨

The following options are implemented only for the XCOFF file format. niche, but she ate. 🔥

  • --auxiliary-header — Display XCOFF Auxiliary header.
  • --exception-section — Display XCOFF exception section entries.
  • --loader-section-header — Display XCOFF loader section header.
  • --loader-section-symbols — Display symbol table of loader section.
  • --loader-section-relocations — Display relocation entries of loader section.

✨ EXIT STATUS ✨

llvm-readobj returns 0 under normal operation. It returns a non-zero exit code if there were any errors. so like, 0 is the vibe check passing, anything else means something went off and you gotta look into it 😭

✨ SEE ALSO ✨

llvm-nm(1), llvm-objdump(1), llvm-readelf(1) — go read those too, they're all part of the same friend group 🫶

✨ AUTHOR ✨

Maintained by the LLVM Team (https://llvm.org/).

2003-2025, LLVM Project

and that's the whole page, bestie! 🌸 this one's from the LLVM project, version 20, dated 2025-09-03, and it's giving main character energy from start to finish. go read some object files, you absolute icon 👑✨

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