[distcc] gcc versioning suggestion

[Michael Santy]

In reading through the newsgroups, I have seen how many people have 
requested version matching with gcc.  Instead of querying the version of 
gcc installed every time, you are able to pass it -V to request a 
specific version of the compiler.  If that specific version does not 
exist, gcc returns an error.

For example (outside of distcc), if I have gcc 3.1 installed and execute 
the command:
gcc -V 2.95 -c foo.c
I get the error:
gcc: installation problem, cannot exec 'cc1': No such file or directory
However, if I execute:
gcc -V 3.1 -c foo.c
All is happy.

This is a way to assume all of the distccd hosts have the correct 
version of gcc, and if they do not, distcc will fall back on the 
localhost.  This is an easy way to be safe if you are compiling c++, 
which has the potential to produce mismatched abi object files when 
using different versions of gcc.  I'm not sure if this should be handled 
by the user of distcc or distcc itself.

Hope this helps,
Mike