xref: /llvm-project/llvm/docs/CommandGuide/llvm-dwarfutil.rst (revision 4539b44148918c332ff966a2a955aca0ab93dde4)
1llvm-dwarfutil - A tool to copy and manipulate debug info
2=========================================================
3
4.. program:: llvm-dwarfutil
5
6SYNOPSIS
7--------
8
9:program:`llvm-dwarfutil` [*options*] *input* *output*
10
11DESCRIPTION
12-----------
13
14:program:`llvm-dwarfutil` is a tool to copy and manipulate debug info.
15
16In basic usage, it makes a semantic copy of the input to the output. If any
17options are specified, the output may be modified along the way, e.g.
18by removing unused debug info.
19
20If "-" is specified for the input file, the input is read from the program's
21standard input stream. If "-" is specified for the output file, the output
22is written to the standard output stream of the program.
23
24The tool is still in active development.
25
26COMMAND-LINE OPTIONS
27--------------------
28
29.. option:: --garbage-collection
30
31 Removes pieces of debug information related to discarded sections.
32 When the linker does section garbage collection the abandoned debug info
33 is left behind. Such abandoned debug info references address ranges using
34 tombstone values. Thus, when this option is specified, the tool removes
35 debug info which is marked with the tombstone value.
36
37 That option is enabled by default.
38
39.. option:: --odr-deduplication
40
41 Remove duplicated types (if "One Definition Rule" is supported by source
42 language). Keeps first type definition and removes other definitions,
43 potentially significantly reducing the size of output debug info.
44
45 That option is enabled by default.
46
47.. option:: --help, -h
48
49 Print a summary of command line options.
50
51.. option:: --no-garbage-collection
52
53 Disable :option:`--garbage-collection`.
54
55.. option:: --no-odr-deduplication
56
57 Disable :option:`--odr-deduplication`.
58
59.. option:: --no-separate-debug-file
60
61 Disable :option:`--separate-debug-file`.
62
63.. option:: --num-threads=<n>, -j
64
65 Specifies the maximum number (`n`) of simultaneous threads to use
66 for processing.
67
68.. option:: --separate-debug-file
69
70 Generate separate file containing output debug info. Using
71 :program:`llvm-dwarfutil` with that option equals to the
72 following set of commands:
73
74.. code-block:: console
75
76 :program:`llvm-objcopy` --only-keep-debug in-file out-file.debug
77 :program:`llvm-objcopy` --strip-debug in-file out-file
78 :program:`llvm-objcopy` --add-gnu-debuglink=out-file.debug out-file
79
80.. option:: --tombstone=<value>
81
82 <value> can be one of the following values:
83
84   - `bfd`: zero for all addresses and [1,1] for DWARF v4 (or less) address ranges and exec.
85
86   - `maxpc`: -1 for all addresses and -2 for DWARF v4 (or less) address ranges.
87
88   - `universal`: both `bfd` and `maxpc`.
89
90   - `exec`: match with address ranges of executable sections.
91
92   The value `universal` is used by default.
93
94.. option:: --verbose
95
96 Enable verbose logging. This option disables multi-thread mode.
97
98.. option:: --verify
99
100 Run the DWARF verifier on the output DWARF debug info.
101
102.. option:: --version
103
104 Print the version of this program.
105
106SUPPORTED FORMATS
107-----------------
108
109The following formats are currently supported by :program:`llvm-dwarfutil`:
110
111ELF
112
113EXIT STATUS
114-----------
115
116:program:`llvm-dwarfutil` exits with a non-zero exit code if there is an error.
117Otherwise, it exits with code 0.
118
119BUGS
120----
121
122To report bugs, please visit <https://github.com/llvm/llvm-project/labels/tools:llvm-dwarfutil/>.
123