Hi Alex,

Thanks for taking a look at the patch!

On 9/9/21 6:52 PM, Alex Xu (Hello71) wrote:

This patch seems awfully complicated, especially considering it still
uses relatively slow stdio instead of direct library calls.

It is comparable in speed to the libbfd variant, apparently: in 
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=911815#38, Steinar 
Gunderson reports that the bfd and patched non-bfd versions have similar 
run-times.

The complication is a bit of a shame, but I think it's reasonable given 
that it is essentially reimplementing a variant of popen(3) with 
bidirectional communication.

Did you look
into calling elfutils instead of libbfd if the latter is not available?

No, I didn't; I don't know the domain very well, so I adapted the 
existing solution to run more efficiently.

On the patch specifically, why was popen changed to socketpair? It looks
like it adds significant complexity, and the advanced features of
socketpair are not being used (SOCK_DGRAM/SOCK_SEQPACKET, SCM_RIGHTS).

Because popen is unidirectional, and with a long-running process we need 
bidirectional communication. I could have used two pipes, but I figured 
socketpair was just sitting there and why spend the extra two fds if I 
didn't have to?

Regards,
   Tony