On Thu, Sep 18, 2025 at 06:37:38PM -0300, Bento Borges Schirmer wrote: > Hey, > > I don't really know how m4 works. That's just an idea that occurred to > me. I think m4 could keep expanding macros and processing text while a > syscmd() is in flight, potentially having several syscmd() executing > at once. The user would have to guarantee that the syscmd() execution > is "pure", that is, that one command does not depend on side effects > of previous executions. All that could be enabled by some flag, like > -j which reminisces Makefile.
You are welcome to try and write such a patch. But currently m4 is single-threaded; what you are proposing would be a massive redesign, in order to handle parallel threads and possible speculative execution followed by rollback if the syscmd was not pure after all. -- Eric Blake, Principal Software Engineer Red Hat, Inc. Virtualization: qemu.org | libguestfs.org
