Re: A little more progress today with clang/LLVM

[Richard Pennington <rich@pennware.com>]

On Friday, May 25, 2012 07:09:38 PM Rich Felker wrote:
> On Fri, May 25, 2012 at 01:56:56PM -0500, Richard Pennington wrote:
> > I've done a little hacking on alltypes.h.sh which I'm in the process of
> > 
> > testing. I have two goals:
> > 	1. Make it work with clang's headers.
> 
> Can you explain what the issue is? Are you talking about issues
> building clang itself, or building programs against musl using clang?
> In the latter case, musl does not use or support using
> compiler-provided headers. All of the standard headers are provided
> fully by musl.

This is good to know. I'll stop using the compiler supplied headers.

[snip]
> One thing that _would_ work for these __typeof__ cases is to put it
> under __GNUC__, which encompasses ALL compilers that have "GNU C"
> extensions like typeof. That would definitely be an acceptable change,
> but unless there are any compilers where it's necessary, I'd rather
> just leave the types explicit for the arch's ABI. One of the most
> frustrating things with glibc headers is never being able to figure
> out the actual underlying definition of a type, and I'd like not to
> recreate that frustration.

You've convinced me. ;-)

> 
> A couple things I'm _NOT_ happy about in my current system are that
> the whole alltypes.h gets parsed again and again even (for each header
> that includes it) even if only a few types are needed each time. One
> thing I'm considering (but not yet decided on) is dropping it and
> instead having the build system generate all the headers from
> templates when musl is built, and put the expanded TYPEDEF templates
> right in the headers that use them.
> 
> In any case, for now don't worry about the potential
> ugliness/duplication in alltypes.h.sh for new archs. It's not a large
> file (the bits/*.h headers are much worse when it comes to
> duplication) and I'm happy to take responsibility for cleaning them
> all up later if a better system is devised.
> 

OK, and thanks for being patient. I'm still trying to absorb the musl 
philosophy.

-Rich