llvm dev - Oct 2010 - [LLVMdev] MAJOR API CHANGE: Pass initialization without static constructors

John,

On Oct 8, 2010, at 1:05 PM, John Criswell wrote:
>>   These initialization routines must be invoked before the PassManager
will be able to resolve pipelines involving your pass.  For convenience, LLVM
now exposes per-library batch initialization routines, i.e.
initializeScalarOpts(), which initialize all the passes within a given library
in a single go.
> 
> From an ease of programming perspective, this solution is not ideal as what
we had before.  Each time I link in a new library into my program, I have to go
find the method that initializes all of the passes and remember to call it from
my tool.  Could you devise something better?  For example, could you extend
PassManager with a method that calls all of the passes's initialization
methods?  In other words, could you easily support something like:
> 
> PassManager.add (Pass1);
> PassManager.add (Pass2);
> ...
> PassManager.add (PassN);
> PassManager.initializeAllPasses ();
> PassManager.run();
> 
> 
> ... or could the PassManager::add() method automatically initialize the
pass?  Other possibilities may exists which are better as well; these are just
the first two I've thought of.
 Chris and I had a discussion about this offline, and he pointed out to me that
we could make this API work if we had statically declared pass dependency
information (that must be guaranteed to be a superset of the true dynamic
dependencies).  If we have that information, then the createPass() methods can
be made to call the initializePass(), which can in turn recursively initialize
its potential dependencies.

I'm putting my current patch (implementing the old version of this proposal)
on hold to evaluate the possibility of going this route instead.

--Owen
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20101011/bf73cfe1/attachment.html>