We have a system where, when bootstrapping, gcc is used to output assembly on the host, and the assembly files are copied to another system, where they are assembled and linked.
Whether we use GNU as and ld or native/vendor is flexible, depending on what works and what I care to build. e.g. AIX is going to require all native/vendor, Irix will require GNU as and vendor ld (until/unless I debug assertion failure in GNU ld). Solaris can probably go either way on as/ld, but currently I'm using Sun for both. I ran into a problem on sparc64-solaris where the .register psuedo op was missing. That's basically the entire problem -- .register is completely absent and the assembler gives lots of errors saying exactly that. No big mystery, no runtime errors, etc. I fixed by hand patching auto-host.h. Next run I'll set gcc_cv_as_sparc_register_op=yes. I think I can phrase this in a more mainstream way. What if build != host, without in-tree binutils/gas? You can't probe the assembler behavior, eh? Maybe gas is ok without .register? ok, if I'm going to use Sun native as? Are there actually old GNU as that target sparc64, but allow omitting .register? I have not looked at the history. More generally, all the business of probing the assembler.. Changing the assembler out from under gcc requires reconfigure/rebuild? Sometimes. In this instance, it looks like it could easily be made a runtime switch. Granted, still not turnkey -- still have to decide a default, and then leave the user to possibly fix it. Unless there is a cheap way to probe at runtime, though that's kind of exactly one of the points -- configure isn't cheap, nor even validation of it. Maybe a "first run" or "configure on host" phase would be nice. I know, it smacks of "setup" instead of just "copy". Any case where gcc needs to know the assembler's behavior..would be fixed by integrating gcc and gas... I guess this is just the general problem of non-native builds, configure done at build-time, but often wants to probe the host environment, not the build environment, and you just muddle along somehow for build != host? Having to set the cv variables isn't deemed so bad? - Jay
