LLVM-SYMBOLIZER(1)

💖 NAME 💖

Okay bestie, welcome to the LLVM manual page for llvm-symbolizer — the tool whose whole job is: convert addresses into source code locations. That’s it. That’s the vibe. Iconic.

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✨ SYNOPSIS ✨

llvm-symbolizer [options] [addresses...]

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🌸 DESCRIPTION 🌸

So 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 Symbolizer Markup via --filter-markup. Slay.

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, or if at any time an input value is not recognized, the input is simply echoed to the output. No cap.

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.

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 llvm-symbolizer is invoked by another program or runtime.

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🦋 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 --demangle).

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

// 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:

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

💅 Example 1 — addresses and object on command-line

$ 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

$ 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

$ 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

$ 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

$ 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.

$ 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

✨ OPTIONS ✨

okay bestie, this is the big one — every single flag, no skips, no cap 💅

• --adjust-vma <offset> — adds that <offset> to object file addresses before doing lookups. basically it lets you do lookups as if the object had been relocated by the offset, cute right? 🦋
• --basenames, -s — prints just the file's name with zero directories attached, instead of the absolute path. so main.cpp instead of the whole dramatic saga 🌸
• --build-id — looks up the object using the given build ID, specified as a hexadecimal string. mutually exclusive with --obj — pick one, bestie, you cannot have both 🤭
• --color [=<always|auto|never>] — says whether to use color in --filter-markup mode. defaults to auto, which detects whether standard output supports color. and if you just write --color all by itself? that's the same as --color=always 💖
• --debuginfod, --no-debuginfod — whether or not to try debuginfod lookups for debug binaries. unless you specify otherwise, 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 ✨
• --demangle, -C — prints demangled function names, if the names are mangled (like, the mangled name _Z3bazv becomes baz(), whilst the non-mangled name foz is printed as is). defaults to true 🫶
• --dwp <path> — use the specified DWP file at <path> for any CUs that have split DWARF debug data 👑
• --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 🔍
• --filter-markup — reads from standard input, converts contained Symbolizer Markup into human-readable form, and prints the results to standard output. the following markup elements are not yet supported (yes, we're waiting on those, don't @ me 😭):
  • {{{hexdict}}}
  • {{{dumpfile}}}

the {{{bt}}} backtrace element reports frames using this syntax, lowkey iconic:

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

<inline> gives you frame numbers for calls inlined into the caller coresponding 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. heads up: the address may not be the start of the instruction. and <relative address> is the corresponding virtual offset in the <module> loaded at that address 💀

• --functions [=<none|short|linkage>], -f — specifies the way function names are printed: omit function name, print short function name, or print full linkage name, respectively. defaults to linkage ⭐
• --help, -h — shows help and usage for this command. the classic 🎀
• --inlining, --inlines, -i — if a source code location is in an inlined function, prints all the inlined frames. this is the default, so it's already doing the most ✨
• --no-inlines — don't print inlined frames. simple as 🙈
• --no-demangle — don't print demangled function names 🦋
• --obj <path>, --exe, -e — path to the object file to be symbolized. if - is specified, read the object directly from the standard input stream. mutually exclusive with --build-id 👑
• --output-style <LLVM|GNU|JSON> — specifies 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.

$ 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
      }
    ]
  }
]

• --pretty-print, -p — prints human readable output. if --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 📦

$ 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

• --print-address, --addresses, -a — prints the address before the source code location. defaults to false 💅

$ 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

• --print-source-context-lines <N> — prints N lines of source context for each symbolized address. it's giving "show me the receipts" 📖

$ 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  : }

• --relativenames — prints 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 🌈
• --verbose — prints verbose address, line and column information. every last crumb 🔥

$ 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

• --version, -v — prints version information for the tool 🎀
• @<FILE> — reads command-line options from response file <FILE>. yes, a whole file of options, she's organized 🗂️

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🪟 WINDOWS/PDB SPECIFIC OPTIONS 🪟

• --dia — use the Windows DIA SDK for symbolization. if the DIA SDK is not found, llvm-symbolizer will fall back to the native implementation. no drama, it just adapts 💜

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🍎 MACH-O SPECIFIC OPTIONS 🍎

• --default-arch <arch> — if a binary contains object files for multiple architectures (e.g. it is a Mach-O universal binary), 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). if the architecture is not specified in either way, the address will not be symbolized. defaults to empty string 😬

$ cat addr.txt
/tmp/mach_universal_binary:i386 0x1f84
/tmp/mach_universal_binary:x86_64 0x100000f24

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

_main
/tmp/source_x86_64.cc:8

• --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, stack 'em 🧚

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🚦 EXIT STATUS 🚦

llvm-symbolizer returns 0. any other exit codes imply an internal program error. so like, if you see anything that isn't 0, something went genuinely wrong bestie, no cap 💀

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👀 SEE ALSO 👀

llvm-addr2line(1) — go give her a read, they're literally cousins 🫶

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🌟 AUTHOR 🌟

maintained by the LLVM Team (https://llvm.org/). shoutout the whole squad 👑

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📜 COPYRIGHT 📜

2003-2023, LLVM Project — respect the legacy, periodt 🎀

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aaaand that's the whole page, bestie!! this was LLVM-SYMBOLIZER(1), source/version 15, dated 2023-01-14 — go symbolize something iconic 💖✨🦋🌸💅