llvm dev - Nov 2002 - [LLVMdev] getAnalysis()

I'm having trouble with using getAnalysis() to access the results of one
pass from within another.  I require the pass to be previously executed
as follows:

void MyPass::getAnalysisUsage(AnalysisUsage &Info) const {
        Info.addRequired<TDDataStructures>();
}

Then I try to use it as follows:

bool MyPass::doInitialization(Module &M) {
        TDDataStructures &dsgraph = getAnalysis<TDDataStructures>();
        return false;
}

When I run my pass via opt, I get the following assertion error:

Assertion failed: i != AnalysisImpls.size() && "getAnalysis*()
called on
an analysis that we not " "'required' by pass!", file
../../include/llvm/Pass.h, line 170

Any idea what I am doing wrong?  Thanks,
Scott Mikula

On Sun, 3 Nov 2002, Scott Mikula wrote:
> I'm having trouble with using getAnalysis() to access the results of
one
> pass from within another.  I require the pass to be previously executed
> as follows:
>
> void MyPass::getAnalysisUsage(AnalysisUsage &Info) const {
>         Info.addRequired<TDDataStructures>();
> }
Is that the only line you have?  There may be some trouble if you also
include a pass that invalidates TDDS before your pass can get to it.
Unfortunately we don't have good diagnostics for this case yet.
> Then I try to use it as follows:
> bool MyPass::doInitialization(Module &M) {
>         TDDataStructures &dsgraph =
getAnalysis<TDDataStructures>();
>         return false;
> }
Hrm, with these two lines I don't see anything that could be wrong.  If
you're using doInitialization, I assume that you're using a
FunctionPass.
Although FunctionPass's should be able to require interprocedural
Pass's,
maybe it's causing a problem here.  Try changing your pass to subclass
Pass directly (and use run), and see if you can still reproduce it.
> Any idea what I am doing wrong?  Thanks,
As far as I can tell, you aren't doing anything wrong.  If the above
doesn't help, please email me (privately) your pass code (whatever state
it is in) so I can debug the situation.

Thanks!

-Chris

-- 
http://llvm.cs.uiuc.edu/
http://www.nondot.org/~sabre/Projects/

Chris Lattner wrote:
> On Sun, 3 Nov 2002, Scott Mikula wrote:
> > I'm having trouble with using getAnalysis() to access the results
of one
> > pass from within another.  I require the pass to be previously
executed
> > as follows:
> >
> > void MyPass::getAnalysisUsage(AnalysisUsage &Info) const {
> >         Info.addRequired<TDDataStructures>();
> > }
>
> Is that the only line you have?  There may be some trouble if you also
> include a pass that invalidates TDDS before your pass can get to it.
> Unfortunately we don't have good diagnostics for this case yet.
>
> > Then I try to use it as follows:
> > bool MyPass::doInitialization(Module &M) {
> >         TDDataStructures &dsgraph =
getAnalysis<TDDataStructures>();
> >         return false;
> > }
>
> Hrm, with these two lines I don't see anything that could be wrong.  If
> you're using doInitialization, I assume that you're using a
FunctionPass.
> Although FunctionPass's should be able to require interprocedural
Pass's,
> maybe it's causing a problem here.  Try changing your pass to subclass
> Pass directly (and use run), and see if you can still reproduce it.
Using a normal Pass instead of a FunctionPass seems to solve the problem.
Should I just go ahead and implement my pass that way, or is there likely to
be a solution to make it work with a FunctionPass?

Scott Mikula