The Compact C Type Format in the GNU toolchain [LWN.net]

The Compact C Type Format in the GNU toolchain

Posted Aug 7, 2019 21:48 UTC (Wed) by nix (subscriber, #2304)
In reply to: The Compact C Type Format in the GNU toolchain by mjw
Parent article: The Compact C Type Format in the GNU toolchain

In general any non-allocated section can be stripped away (or put into a separate .debug file). Because that simply means that the section isn't needed at runtime.

Well, it means it isn't needed by the executable loader. I was *forced* to make libctf non-loadable by internal constraints in ld (roughly, that you cannot simultaneously have an allocated section whose size is not known before bfd_elf_final_link() and that the symtab and strtab are not laid out until halfway through that function and that CTF needs to know the offsets of all strings in the strtab and the order of symbols, *and* it's compressed so its content affects its size: so by extension the section may not be allocated). That doesn't mean it's not going to be used by programs at runtime. It is. (Well, assuming anyone uses it at all. :) ). They load it out of the binary as needed using BFD.