llvm/docs/CommandGuide/llvm-dwarfutil.md

# llvm-dwarfutil - A tool to copy and manipulate debug info

```{program} llvm-dwarfutil
```

## SYNOPSIS

{program}`llvm-dwarfutil` \[*options*\] *input* *output*

## DESCRIPTION

{program}`llvm-dwarfutil` is a tool to copy and manipulate debug info.

In basic usage, it makes a semantic copy of the input to the output. If any
options are specified, the output may be modified along the way, e.g.
by removing unused debug info.

If "-" is specified for the input file, the input is read from the program's
standard input stream. If "-" is specified for the output file, the output
is written to the standard output stream of the program.

The tool is still in active development.

## COMMAND-LINE OPTIONS

:::{option} --garbage-collection
Removes pieces of debug information related to discarded sections.
When the linker does section garbage collection the abandoned debug info
is left behind. Such abandoned debug info references address ranges using
tombstone values. Thus, when this option is specified, the tool removes
debug info which is marked with the tombstone value.

That option is enabled by default.
:::

:::{option} --odr-deduplication
Remove duplicated types (if "One Definition Rule" is supported by source
language). Keeps first type definition and removes other definitions,
potentially significantly reducing the size of output debug info.

That option is enabled by default.
:::

:::{option} --help, -h
Print a summary of command line options.
:::

:::{option} --no-garbage-collection
Disable {option}`--garbage-collection`.
:::

:::{option} --no-odr-deduplication
Disable {option}`--odr-deduplication`.
:::

:::{option} --no-separate-debug-file
Disable {option}`--separate-debug-file`.
:::

:::{option} --num-threads=<n>, -j
Specifies the maximum number (`n`) of simultaneous threads to use
for processing.
:::

:::{option} --separate-debug-file
Generate separate file containing output debug info. Using
{program}`llvm-dwarfutil` with that option equals to the
following set of commands:
:::

```console
:program:`llvm-objcopy` --only-keep-debug in-file out-file.debug
:program:`llvm-objcopy` --strip-debug in-file out-file
:program:`llvm-objcopy` --add-gnu-debuglink=out-file.debug out-file
```

:::{option} --tombstone=<value>
\<value> can be one of the following values:

- `bfd`: zero for all addresses and [1,1] for DWARF v4 (or less) address ranges and exec.
- `maxpc`: -1 for all addresses and -2 for DWARF v4 (or less) address ranges.
- `universal`: both `bfd` and `maxpc`.
- `exec`: match with address ranges of executable sections.

The value `universal` is used by default.
:::

:::{option} --verbose
Enable verbose logging. This option disables multi-thread mode.
:::

:::{option} --verify
Run the DWARF verifier on the output DWARF debug info.
:::

:::{option} --version
Print the version of this program.
:::

## SUPPORTED FORMATS

The following formats are currently supported by {program}`llvm-dwarfutil`:

ELF

## EXIT STATUS

{program}`llvm-dwarfutil` exits with a non-zero exit code if there is an error.
Otherwise, it exits with code 0.

## BUGS

To report bugs, please visit \<<https://github.com/llvm/llvm-project/labels/tools:llvm-dwarfutil/>>.