llvm/docs/CommandGuide/llvm-symbolizer.md

# llvm-symbolizer - convert addresses into source code locations

:::{program} llvm-symbolizer
:::

## SYNOPSIS

{program}`llvm-symbolizer` \[*options*\] \[*addresses...*\]

## DESCRIPTION

{program}`llvm-symbolizer` reads input names and addresses from the command-line
and prints corresponding source code locations to standard output. It can also
symbolize logs containing {doc}`Symbolizer Markup </SymbolizerMarkupFormat>` via
{option}`--filter-markup`. Addresses may be specified as numbers or symbol names.

If no address is specified on the command-line, it reads the addresses from
standard input. If no input name is specified on the command-line, but addresses
are, the first address value is treated as an input name. If an input value is not
recognized, it reports that source information is not found.

Input names can be specified together with the addresses either on standard
input or as positional arguments on the command-line. By default, input names
are interpreted as object file paths. However, prefixing a name with
`BUILDID:` states that it is a hex build ID rather than a path. This will look
up the corresponding debug binary. For consistency, prefixing a name with
`FILE:` explicitly states that it is an object file path (the default).

A positional argument or standard input value can be preceded by "DATA" or
"CODE" to indicate that the address should be symbolized as data or executable
code respectively. If neither is specified, "CODE" is assumed. DATA is
symbolized as address and symbol size rather than line number.

{program}`llvm-symbolizer` parses options from the environment variable
`LLVM_SYMBOLIZER_OPTS` after parsing options from the command line.
`LLVM_SYMBOLIZER_OPTS` is primarily useful for supplementing the command-line
options when {program}`llvm-symbolizer` is invoked by another program or
runtime.

## EXAMPLES

All of the following examples use the following two source files as input. They
use a mixture of C-style and C++-style linkage to illustrate how these names are
printed differently (see {option}`--demangle`).

```c
// test.h
extern "C" inline int foz() {
  return 1234;
}
```

```c
// test.cpp
#include "test.h"
int bar=42;

int foo() {
  return bar;
}

int baz() {
  volatile int k = 42;
  return foz() + k;
}

int main() {
  return foo() + baz();
}
```

These files are built as follows:

```console
$ clang -g test.cpp -o test.elf
$ clang -g -O2 test.cpp -o inlined.elf
```

Example 1 - addresses and object on command-line:

```console
$ llvm-symbolizer --obj=test.elf 0x4004d0 0x400490
foz
/tmp/test.h:1:0

baz()
/tmp/test.cpp:11:0
```

Example 2 - addresses on standard input:

```console
$ cat addr.txt
0x4004a0
0x400490
0x4004d0
$ llvm-symbolizer --obj=test.elf < addr.txt
main
/tmp/test.cpp:15:0

baz()
/tmp/test.cpp:11:0

foz
/tmp/./test.h:1:0
```

Example 3 - object specified with address:

```console
$ llvm-symbolizer "test.elf 0x400490" "FILE:inlined.elf 0x400480"
baz()
/tmp/test.cpp:11:0

foo()
/tmp/test.cpp:8:10

$ cat addr2.txt
FILE:test.elf 0x4004a0
inlined.elf 0x400480

$ llvm-symbolizer < addr2.txt
main
/tmp/test.cpp:15:0

foo()
/tmp/test.cpp:8:10
```

Example 4 - BUILDID and FILE prefixes:

```console
$ llvm-symbolizer "FILE:test.elf 0x400490" "DATA BUILDID:123456789abcdef 0x601028"
baz()
/tmp/test.cpp:11:0

bar
6295592 4

$ cat addr3.txt
FILE:test.elf 0x400490
DATA BUILDID:123456789abcdef 0x601028

$ llvm-symbolizer < addr3.txt
baz()
/tmp/test.cpp:11:0

bar
6295592 4
```

Example 5 - CODE and DATA prefixes:

```console
$ llvm-symbolizer --obj=test.elf "CODE 0x400490" "DATA 0x601028"
baz()
/tmp/test.cpp:11:0

bar
6295592 4

$ cat addr4.txt
CODE test.elf 0x4004a0
DATA inlined.elf 0x601028

$ llvm-symbolizer < addr4.txt
main
/tmp/test.cpp:15:0

bar
6295592 4
```

Example 6 - path-style options:

This example uses the same source file as above, but the source file's
full path is /tmp/foo/test.cpp and is compiled as follows. The first case
shows the default absolute path, the second --basenames, and the third
shows --relativenames.

```console
$ pwd
/tmp
$ clang -g foo/test.cpp -o test.elf
$ llvm-symbolizer --obj=test.elf 0x4004a0
main
/tmp/foo/test.cpp:15:0
$ llvm-symbolizer --obj=test.elf 0x4004a0 --basenames
main
test.cpp:15:0
$ llvm-symbolizer --obj=test.elf 0x4004a0 --relativenames
main
foo/test.cpp:15:0
```

Example 7 - Addresses as symbol names:

```console
$ llvm-symbolizer --obj=test.elf main
main
/tmp/test.cpp:14:0
$ llvm-symbolizer --obj=test.elf "CODE foz"
foz
/tmp/test.h:1:0
```

Example 8 - {option}`--skip-line-zero` output for an address with no line correspondence (an address associated with line zero):

```c
// test.c
int foo = 0;
int x = 1234;
int main() {
  if (x)
    return foo;
  else
    return x;
}
```

These files are built as follows:

```console
$ clang -g -O2 -S test.c -o test.s
$ llvm-mc -filetype=obj -triple=x86_64-unknown-linux  test.s -o test.o
```

```console
$ llvm-symbolizer --obj=test.o --skip-line-zero 0xa
main
/tmp/test.c:5:7 (approximate)
```

## OPTIONS

:::{option} --adjust-vma <offset>
Add the specified offset to object file addresses when performing lookups.
This can be used to perform lookups as if the object were relocated by the
offset.
:::

:::{option} --skip-line-zero
If an address does not have an associated line number, use the last line
number from the current sequence in the line-table. Such lines are labeled
as "approximate" in the output as they may be misleading.
:::

:::{option} --basenames, -s
Print just the file's name without any directories, instead of the
absolute path.
:::

:::{option} --build-id
Look up the object using the given build ID, specified as a hexadecimal
string. Mutually exclusive with {option}`--obj`.
:::

:::{option} --color [=<always|auto|never>]
Specify whether to use color in {option}`--filter-markup` mode. Defaults to
`auto`, which detects whether standard output supports color. Specifying
`--color` alone is equivalent to `--color=always`.
:::

:::{option} --debug-file-directory <path>
Provide a path to a directory with a `.build-id` subdirectory to search for
debug information for stripped binaries. Multiple instances of this argument
are searched in the order given.
:::

:::{option} --debuginfod, --no-debuginfod
Whether or not to try debuginfod lookups for debug binaries. Unless specified,
debuginfod is only enabled if libcurl was compiled in (`LLVM_ENABLE_CURL`)
and at least one server URL was provided by the environment variable
`DEBUGINFOD_URLS`.
:::

(llvm-symbolizer-opt-c)=

:::{option} --demangle, -C
Print demangled function names, if the names are mangled (e.g. the mangled
name `_Z3bazv` becomes `baz()`, whilst the non-mangled name `foz` is printed
as is). Defaults to true.
:::

:::{option} --dwp <path>
Use the specified DWP file at `<path>` for any CUs that have split DWARF
debug data.
:::

:::{option} --fallback-debug-path <path>
When a separate file contains debug data, and is referenced by a GNU debug
link section, use the specified path as a basis for locating the debug data if
it cannot be found relative to the object.
:::

:::{option} --filter-markup
Reads from standard input, converts contained
{doc}`Symbolizer Markup </SymbolizerMarkupFormat>` into human-readable form,
and prints the results to standard output. The following markup elements are
not yet supported:

- `{{{hexdict}}}`
- `{{{dumpfile}}}`

The `{{{bt}}}` backtrace element reports frames using the following syntax:

`#<number>[.<inline>] <address> <function> <file>:<line>:<col> (<module>+<relative address>)`

`<inline>` provides frame numbers for calls inlined into the caller
corresponding to `<number>`. The inlined call numbers start at 1 and increase
from callee to caller.

`<address>` is an address inside the call instruction to the function. The
address may not be the start of the instruction. `<relative address>` is
the corresponding virtual offset in the `<module>` loaded at that address.
:::

(llvm-symbolizer-opt-f)=

:::{option} --functions [=<none|short|linkage>], -f
Specify the way function names are printed (omit function name, print short
function name, or print full linkage name, respectively). Defaults to
`linkage`.
:::

:::{option} --help, -h
Show help and usage for this command.
:::

(llvm-symbolizer-opt-i)=

:::{option} --inlining, --inlines, -i
If a source code location is in an inlined function, prints all the inlined
frames. This is the default.
:::

:::{option} --no-inlines
Don't print inlined frames.
:::

:::{option} --no-demangle
Don't print demangled function names.
:::

:::{option} --obj <path>, --exe, -e
Path to object file to be symbolized. If `-` is specified, read the object
directly from the standard input stream. Mutually exclusive with
{option}`--build-id`.
:::

(llvm-symbolizer-opt-output-style)=

:::{option} --output-style <LLVM|GNU|JSON>
Specify the preferred output style. Defaults to `LLVM`. When the output
style is set to `GNU`, the tool follows the style of GNU's **addr2line**.
The differences from the `LLVM` style are:

- Does not print the column of a source code location.
- Does not add an empty line after the report for an address.
- Does not replace the name of an inlined function with the name of the
  topmost caller when inlined frames are not shown.
- Prints an address's debug-data discriminator when it is non-zero. One way to
  produce discriminators is to compile with clang's -fdebug-info-for-profiling.

`JSON` style provides a machine-readable output in JSON. If addresses are

: supplied via stdin, the output JSON will be a series of individual objects.
  Otherwise, all results will be contained in a single array.

```console
$ llvm-symbolizer --obj=inlined.elf 0x4004be 0x400486 -p
baz() at /tmp/test.cpp:11:18
 (inlined by) main at /tmp/test.cpp:15:0

foo() at /tmp/test.cpp:6:3

$ llvm-symbolizer --output-style=LLVM --obj=inlined.elf 0x4004be 0x400486 -p --no-inlines
main at /tmp/test.cpp:11:18

foo() at /tmp/test.cpp:6:3

$ llvm-symbolizer --output-style=GNU --obj=inlined.elf 0x4004be 0x400486 -p --no-inlines
baz() at /tmp/test.cpp:11
foo() at /tmp/test.cpp:6

$ clang -g -fdebug-info-for-profiling test.cpp -o profiling.elf
$ llvm-symbolizer --output-style=GNU --obj=profiling.elf 0x401167 -p --no-inlines
main at /tmp/test.cpp:15 (discriminator 2)

$ llvm-symbolizer --output-style=JSON --obj=inlined.elf 0x4004be 0x400486 -p
[
  {
    "Address": "0x4004be",
    "ModuleName": "inlined.elf",
    "Symbol": [
      {
        "Column": 18,
        "Discriminator": 0,
        "FileName": "/tmp/test.cpp",
        "FunctionName": "baz()",
        "Line": 11,
        "StartAddress": "0x4004be",
        "StartFileName": "/tmp/test.cpp",
        "StartLine": 9
      },
      {
        "Column": 0,
        "Discriminator": 0,
        "FileName": "/tmp/test.cpp",
        "FunctionName": "main",
        "Line": 15,
        "StartAddress": "0x4004be",
        "StartFileName": "/tmp/test.cpp",
        "StartLine": 14
      }
    ]
  },
  {
    "Address": "0x400486",
    "ModuleName": "inlined.elf",
    "Symbol": [
      {
        "Column": 3,
        "Discriminator": 0,
        "FileName": "/tmp/test.cpp",
        "FunctionName": "foo()",
        "Line": 6,
        "StartAddress": "0x400486",
        "StartFileName": "/tmp/test.cpp",
        "StartLine": 5
      }
    ]
  }
]
```
:::

:::{option} --pdb <path>
Use the specified PDB file at `<path>`, overriding the PDB info
contained in the COFF object.
:::

:::{option} --pretty-print, -p
Print human-readable output. If {option}`--inlining` is specified, the
enclosing scope is prefixed by (inlined by).
For JSON output, the option will cause JSON to be indented and split over
new lines. Otherwise, the JSON output will be printed in a compact form.

```console
$ llvm-symbolizer --obj=inlined.elf 0x4004be --inlining --pretty-print
baz() at /tmp/test.cpp:11:18
 (inlined by) main at /tmp/test.cpp:15:0
```
:::

:::{option} --print-address, --addresses, -a
Print address before the source code location. Defaults to false.

```console
$ llvm-symbolizer --obj=inlined.elf --print-address 0x4004be
0x4004be
baz()
/tmp/test.cpp:11:18
main
/tmp/test.cpp:15:0

$ llvm-symbolizer --obj=inlined.elf 0x4004be --pretty-print --print-address
0x4004be: baz() at /tmp/test.cpp:11:18
 (inlined by) main at /tmp/test.cpp:15:0
```
:::

:::{option} --print-source-context-lines <N>
Print `N` lines of source context for each symbolized address.

```console
$ llvm-symbolizer --obj=test.elf 0x400490 --print-source-context-lines=3
baz()
/tmp/test.cpp:11:0
10  :   volatile int k = 42;
11 >:   return foz() + k;
12  : }
```
:::

:::{option} --relativenames
Print the file's path relative to the compilation directory, instead
of the absolute path. If the command-line to the compiler included
the full path, this will be the same as the default.
:::

:::{option} --verbose
Print verbose address, line and column information.

```console
$ llvm-symbolizer --obj=inlined.elf --verbose 0x4004be
baz()
  Filename: /tmp/test.cpp
  Function start filename: /tmp/test.cpp
  Function start line: 9
  Function start address: 0x4004b6
  Line: 11
  Column: 18
main
  Filename: /tmp/test.cpp
  Function start filename: /tmp/test.cpp
  Function start line: 14
  Function start address: 0x4004b0
  Line: 15
  Column: 18
```
:::

:::{option} --version, -v
Print version information for the tool.
:::

:::{option} @<FILE>
Read command-line options from response file `<FILE>`.
:::

## WINDOWS/PDB SPECIFIC OPTIONS

:::{option} --dia
Use the Windows DIA SDK for symbolization. If the DIA SDK is not found,
llvm-symbolizer will fall back to the native implementation.
:::

## MACH-O SPECIFIC OPTIONS

:::{option} --default-arch <arch>
If a binary contains object files for multiple architectures (e.g. it is a
Mach-O universal binary or an archive with architecture variants),
symbolize the object file for a given architecture. You can also specify
the architecture by writing `binary_name:arch_name` in the input (see
example below). For archives, the format `archive.a(member.o):arch`
is also supported. If the architecture is not specified,
the address will not be symbolized. Defaults to empty string.

```console
$ cat addr.txt
/tmp/mach_universal_binary:i386 0x1f84
/tmp/mach_universal_binary:x86_64 0x100000f24
/tmp/archive.a(member.o):ppc 0x1000
/tmp/archive.a(member.o):ppc64 0x2000

$ llvm-symbolizer < addr.txt
_main
/tmp/source_i386.cc:8

_main
/tmp/source_x86_64.cc:8

_foo
/tmp/source_ppc.cc:12

_foo
/tmp/source_ppc64.cc:12
```
:::

:::{option} --dsym-hint <path/to/file.dSYM>
If the debug info for a binary isn't present in the default location, look for
the debug info at the .dSYM path provided via this option. This flag can be
used multiple times.
:::

## EXIT STATUS

{program}`llvm-symbolizer` returns 0. Other exit codes imply an internal program
error.

## SEE ALSO

{manpage}`llvm-addr2line(1)`