Isn't there a possibility to cache the results of the system checks
inside incdir.sh?
The cost of getting 'os' is fork + new shell + uname
The cost of gcc is fork + new shell + grep
The cost of exfile if for + new shell + basename
Yes, so that does have to fork a lot of additional shell instances.
Perhaps you could use environment variables to cache results. I
think that Bash can access environment variables without forking.
For example, I think that you replace the line:
os=`uname -o 2>/dev/null || echo "Other"`
with
|if[-z ${os+x}];then|
export os=`uname -o 2>/dev/null || echo "Other"`
fi
See discussion of syntax at
https://stackoverflow.com/questions/3601515/how-to-check-if-a-variable-is-set-in-bash
We could probably greatly improve build performance if this were done
throughout the OS. An alternative might be to set a large set of
environment variables as part of the 'make context' phase.
In either case, we would also have to unset the environment variables
on distclean as well.
Another, probably better solution, would be to re-write incdir.sh in C.
Then it would not require a fork to bet to uname() or basename(). Host
C is supported on all platforms and would not require additional build
tools (as would, say, Python or other scripting language). C is also
portable and can work in all POSIX environments and Windows native
environments.
There are C versions of several .sh files under tools now, so it is not
a radical idea.
And actually it would not be too difficult to do. I could even do that
if you agree to that solution.
