[LLVMdev] [llvm-commits] CVS: llvm/lib/Transforms/Hello/Makefile

[Reid Spencer]

Chris,

On Fri, 2007-04-13 at 12:39 -0700, Chris Lattner wrote:
> On Fri, 13 Apr 2007, Devang Patel wrote:
> >> I think libhello should drop its use of SlowOperationInformer.
> >
> > That'll fix Hello example. However, anyone trying to load their custom
> > pass will likely to run into this again.
> 
> It is a long-standing issue.  The deal is that libsupport (and many 
> others) are .a files.  If one of the .o files in the .a file is used by a 
> plugin, but not by the tool, they will get link errors.  There isn't a 
> good solution to this, I'd rather keep libhello as a santity test rather 
> than a test for a complete solution.  :)
> 
> For any specific client, they can do things to link the needed .o files 
> in.  For example, we could make opt reference a symbol in 
> slowoperationinformer.  I don't think it's important enough to do this 
> though.

I actually disagree with this. For those tools that offer a "-load"
option (and only those tools), the tool should guarantee its clients a
reasonably trouble free linkage by ensuring that all the symbols from
VMCore, System and Support are available. The writer of the loadable
module should never link against these libraries so the symbol
references are left undefined in the module.  This will solve 99% of the
loading issues we have.

> 
> -Chris
>