[LLVMdev] How to use a FunctionPass in a ModulePass?

[gauss]

Hi, all:

 

I wanted to use a FunctionPass (e.g. MemoryDependenceAnalysis) in a ModulePass, and then I used the method  "getAnalysis<MemoryDependenceAnalysis>(llvm::Function *)"  described at http://llvm.org/docs/WritingAnLLVMPass.html#ModulePass to get the FunctionPass. But , it still crashed when I invoked this pass in tool 'opt'.

 

However, if I change my pass to inherit from FunctionPass, then everything goes well. But I must use the ModulePass to solve my problem. What can I do now?

 

Following is the project file and crash infomation.

 

--------------------------------------part of my project file--------------------------------------------------------

  struct pFuncName : public ModulePass {
    ......

    virtual bool runOnModule(Module &M)

    {
       for(Module::iterator mib=M.begin(), mie=M.end(); mib!=mie; ++mib)
       {
            MemoryDependenceAnalysis &mda = getAnalysis<MemoryDependenceAnalysis>(*f);                  // I have noticed

            ......
       }
       return false;
    }

 

    void getAnalysisUsage(AnalysisUsage &AU) const

    {
        AU.addRequired<MemoryDependenceAnalysis>();
    }
 };

 

 

-----------------------------------------------crash infomation----------------------------------------------------

 

$ opt -load /home/****/llvm-2.5/Debug/lib/g_pFuncName.so -g_pFuncName < test.bc > /dev/null
opt: /home/****/llvm-2.5/include/llvm/Target/TargetData.h:114: llvm::TargetData::TargetData(): Assertion `0 && "ERROR: Bad TargetData ctor used.  " "Tool did not specify a TargetData to use?"' failed.
0   opt       0x08604986
1   opt       0x08604cc8
2             0x003ba400 __kernel_sigreturn + 0
3   libc.so.6 0x009cce28 abort + 392
4   libc.so.6 0x009c440e __assert_fail + 238
5   opt       0x08507bc5 llvm::Pass* llvm::callDefaultCtor<llvm::TargetData>() + 0
6   opt       0x08507be2 llvm::Pass* llvm::callDefaultCtor<llvm::TargetData>() + 29
7   opt       0x08596996 llvm::PassInfo::createPass() const + 126
8   opt       0x0859156a llvm::PMTopLevelManager::schedulePass(llvm::Pass*) + 284
9   opt       0x085915f1 llvm::PMTopLevelManager::schedulePass(llvm::Pass*) + 419
10  opt       0x0859b9ec llvm::FunctionPassManagerImpl::add(llvm::Pass*) + 30
11  opt       0x085917ab llvm::MPPassManager::addLowerLevelRequiredPass(llvm::Pass*, llvm::Pass*) + 315
12  opt       0x08592636 llvm::PMDataManager::add(llvm::Pass*, bool) + 816
13  opt       0x08592a81 llvm::ModulePass::assignPassManager(llvm::PMStack&, llvm::PassManagerType) + 137
14  opt       0x0859b8a9 llvm::PassManagerImpl::addTopLevelPass(llvm::Pass*) + 237
15  opt       0x08591642 llvm::PMTopLevelManager::schedulePass(llvm::Pass*) + 500
16  opt       0x0859b9cc llvm::PassManagerImpl::add(llvm::Pass*) + 30
17  opt       0x08591667 llvm::PassManager::add(llvm::Pass*) + 27
18  opt       0x082d10c2
19  opt       0x082d2f03 main + 3181
20  libc.so.6 0x009b66e5 __libc_start_main + 229
21  opt       0x082c4641
Aborted (core dumped)
---------------------------------------------------------------------------------------------------------------

 

Thanks a lot.

 

gauss

[Devang Patel]

On Mon, Aug 10, 2009 at 3:35 AM, gauss<gaus...@gmail.com> wrote:
> Hi, all:
>
> I wanted to use a FunctionPass (e.g. MemoryDependenceAnalysis) in a
> ModulePass, and then I used the method
> "getAnalysis<MemoryDependenceAnalysis>(llvm::Function *)"  described at
> http://llvm.org/docs/WritingAnLLVMPass.html#ModulePass to get the
> FunctionPass. But , it still crashed when I invoked this pass in tool 'opt'.
>
> However, if I change my pass to inherit from FunctionPass, then everything
> goes well. But I must use the ModulePass to solve my problem. What can I do
> now?

As the docs say, the function pass must not require any other module
pass (or immutable pass) here. This is a limitation of current
implementation. I'll update docs to list "immutable pass" explicitly.

-
Devang

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[gauss]

Hi, Devang. Thank you for your reply.

But in my case, my ModulePass requires another FunctionPass (e.g.
MemoryDependenceAnalysis) rather than the opposite direction. Is it also
limited?

-
gauss

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[Devang Patel]

On Mon, Aug 10, 2009 at 6:48 PM, gauss<gaus...@gmail.com> wrote:
>
> Hi, Devang. Thank you for your reply.
>
> But in my case, my ModulePass requires another FunctionPass (e.g.
> MemoryDependenceAnalysis) rather than the opposite direction. Is it also
> limited?

Yes, this limitation applies when a ModulePass requires a FunctionPass.