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[John Criswell <criswell AT illinois.edu>]

On 4/13/11 1:08 AM, Matthew Wala wrote:
> Hi everyone:
> I've been trying to move code that uses DSA from the StringTransform
> module into the CompleteChecks pass (I discussed doing this with John
> on Thursday). The StringTransform module currently uses DSA to
> determine the completeness of the string arguments before passing them
> into transformed function calls. When DSA says nodes are complete when
> computed in StringTransform, after the string function calls are
> transformed I try to compute the same information in CompleteChecks
> and get that the nodes are marked external. Is this because DSA treats
> the transformed functions as external functions? I'm not sure, but if
> it is, how do I fix this?

Yes, it is most likely the case that DSA considers the pool_str* 
functions as external functions.  You need to modify lib/DSA/StdLib.cpp 
so that it recognizes them as "intrinsic" functions.  For now, just 
implement the code in CompleteChecks and then tackle the external 
problem in DSA.

> (On a side note: To get what I wanted to do above, I had to reorder
> the execution of StringTransform so that it comes before
> CompleteChecks. Would that break anything?)

No.  In fact, this is as it should be in the new design: all of the 
SAFECode transforms run first, then CompleteChecks and APA run to mark 
checks complete and to fill in pool handles.

So, to step up a level, you can divide the work into 4 steps:

1) Implement the CStdLib run-time checks.  This by itself should make 
the checks work without APA.
2) Modify APA to fill in the pools in the run-time checks.  Now your new 
checks work with APA.
3) Modify CompleteChecks to modify the completeness flag as appropriate.
4) Modify DSA to recognize the new run-time check.
5) Repeat steps 1-4 for each batch of run-time checks that you implement.

Each step can be committed to SVN separately to avoid large complicated 
changes.

-- John T.

> Matt
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