What's the “discriminator” in addr2line?

Question

When running addr2line in some programs, I get a "discriminator N" comment at the end of the line:

main at /tmp/nsievebits.c:56 (discriminator 3)

The man page doesn't mention it, and a quick Google search seems to indicate mostly source code files, with no clear explanation. Is it some intentionally undocumented feature? More importantly, should I worry about it at all?

Answer 1

As far as I understand, discriminator can be useful when there are more than one code path on a single line, see more there . You can safely ignore those, but if one knows how to read them, they can give you very precise information about where exactly the stack points to.