[LLVMdev] Pass Ordering

[John Criswell]

aparna kotha wrote:
> I am using opt , so i cm confused if i need to do this. On the other 
> hand I modified my functionPass not to call TargetData , and I still 
> get this error. My functionPass still calls Alias Analysis though.

You're correct; you shouldn't need to do that in opt, so I'm confused as 
to why it didn't work before.

In your function pass with the use of TargetData removed, what does your 
getAnalysisUsage() method look like?  Did you remove the 
getAnalysis<TargetData>() call in the other methods of your function 
pass?  Both must be removed for your FunctionPass to be totally free of 
TargetData.

Did you remove TargetData from you ModulePass as well?

-- John T.

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> Aparna 
>
> On Fri, Aug 13, 2010 at 2:15 PM, John Criswell <criswell at illinois.edu 
> <mailto:criswell at illinois.edu>> wrote:
>
>     aparna kotha wrote:
>
>         All,
>         I have a ModulePass (A) calling a FunctionPass that inturn
>         calls TargetData (a ModulePass). For reasons of code
>         correctness and modularity I cannot reorganize my passes in
>         any other way .
>         When I use opt to load and run A , it gives the following error.
>         LLVM ERROR: Bad TargetData ctor used.  Tool did not specify a
>         TargetData to use?
>
>
>         I gather from some previous emails that this was not
>         supported. Is it still not supported? and is there any way I
>         can avoid this.
>
>
>     For some reason, the TargetData pass must use a special
>     constructor method that gives it a reference to the module to be
>     analyzed.  This means that declaring it as a dependency in your
>     getAnalysisUsage() methods isn't enough; whatever program is
>     adding your passes to the PassManager must add TargetData
>     explicitly as one of the passes to run.
>
>     The opt program does this automatically, so I'm assuming you're
>     writing your own tool that creates a PassManager and tells it to
>     run some passes.  You want to add code like the following to your
>     tool:
>
>     PassManager Passes;   // This line probably exists in your code
>     already
>
>     // Explicitly schedule the TargetData pass as the first pass to
>     run; note that M.get() gets a pointer or reference
>     // to the module to analyze
>     Passes.add(new TargetData(M.get()));
>
>     -- John T.
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>      
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>
>         Thanks and Regards
>
>
>         Aparna Kotha
>         Graduate Student University of Maryland, College Park
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