Parse ELF symbol version files

[pombredanne]

It could be useful to parse specific file formats such as "version.lds" files and other files to collect ELF versioning information.

For instance, some project such as libfdt use version.lds, while OpenSSL uses .num files (in https://github.com/openssl/openssl/blob/master/util/libssl.num ) and tensorflow uses the .lds extensions but with a different name pattern.

[armijnhemel]

glibc uses Versions, for example:

$ find |grep Versions| sort
./argp/Versions
./assert/Versions
./catgets/Versions
./csu/Versions
./ctype/Versions
./debug/Versions
./dirent/Versions
./dlfcn/Versions
./elf/Versions
./gmon/Versions
./hesiod/Versions
./htl/Versions
./hurd/Versions
./iconv/Versions

[armijnhemel]

In ELF files i have been able to find the following versions:

• various GCC related ones, such as @GCC_3.3.1
• libreport, such as @LIBREPORT_2.13.1
• abrt, such as @LIBRABRT_2.14.5
• xz, such as @XZ_5.0
• json, such as @JSONC_0.14
• systemd, such as @LIBSYSTEMD_209
• alsa ( @ALSA_0.9 )
• fdisk
• elfutils
• fuse
• gpg
• and a whole bunch more

A few quick and dirty commands to find these:

$ cd /usr/bin
$ readelf -Wa * | grep @ | grep UND > /tmp/symbols
$ cut -f 2- -d @ symbols2 | sort | cut -f 1 -d '(' | uniq

[armijnhemel]

Different projects use different conventions. Take elfutils: https://github.com/sourceware-org/elfutils

This project uses .map as the extension, for example:

https://github.com/sourceware-org/elfutils/blob/master/libelf/libelf.map

libxmlb also uses .map as the extension.

There isn't a standard file name. You either have to already "know" it, or add some extra information to your search process, such as the name + version that you are looking for (this is something you can extract from binary files, see above). Probably it is best to just keep a mapping of version files per project somewhere and just use that.