LLVM错误访问函数传递中的loopinfo

问题描述

我正在尝试通过编写函数传递从IR获取循环信息.因此，我遵循了一些示例，并编写如下.我对编写通行证和通行证管理者不是很熟悉.

I'm trying to get loop information from IR by writing a function pass. So I followed some examples and wrote like following. I'm not very familiar with writing passes and pass managers.

#include <iostream>
#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Function.h"
#include "llvm/BasicBlock.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Support/IRReader.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Pass.h"
#include "llvm/PassManager.h"

using namespace llvm;

namespace {
    class DetectLoop: public FunctionPass {
    public:
        DetectLoop() : FunctionPass(ID) {}

        static char ID;

        virtual void getAnalysisUsage(AnalysisUsage &AU) const {
            AU.addRequired<LoopInfo>();//I'm not sure if it's correct here *****1*****
        }

        virtual bool runOnFunction(Function &F) {
            if (!F.isDeclaration())
                LoopInfo &li = getAnalysis<LoopInfo>(F);//*****2*****
            for (Function::iterator I = F.begin(); I != F.end(); I++) {
                BasicBlock *BB = I;
                for (BasicBlock::iterator BI = BB->begin(), BE = BB->end(); BI != BE;) {
                    Instruction &I = *BI++;
                    //did noting inside
                }
            }
            return false;
        }
    };
}

char DetectLoop::ID = 0;

int main(int argc, char** argv)
{
    if (argc < 2) {
        errs() << "Expected an argument - IR file name\n";
        exit(1);
    }

    SMDiagnostic Err;
    std::cout<<argv[1]<<std::endl;
    Module *Mod = ParseIRFile(argv[1], Err, getGlobalContext());
    Err.Print(argv[0], errs());


    if (Mod) {
        PassManager PM;
        PM.add(new DetectLoop());
        PM.add(new LoopInfo());//*****3*****
        PM.run(*Mod);
    }
    else {
        std::cout << "Mod is null" << std::endl;
    }

    return 0;
}

当我运行此程序时，它只是向我显示了segmentation error(core dumped)，

While I was running this program, it just showed me segmentation error(core dumped),

但是当我注释掉 addRequired 时，我得到的错误消息是

but when I commented out addRequired the error msg I got was

IRparser: PassManager.cpp:1200: virtual llvm::Pass* llvm::PMDataManager::getOnTheFlyPass
(llvm::Pass*, llvm::AnalysisID, llvm::Function&): Assertion `0 && "Unable to find on the fly pass"' failed.
Stack dump:
0.  Running pass 'Function Pass Manager' on module '../../testcase/forloop1.ll'.
1.  Running pass 'Unnamed pass: implement Pass::getPassName()' on function '@main'
Aborted (core dumped)

我已经标记了3个不确定的地方.有人可以帮我吗?

I have marked 3 places I'm not sure which is correct or not. Can anyone help me with that?

推荐答案

如果在模块中使用它:

LoopInfo &li = getAnalysis<LoopInfo>(F)

如果在函数中使用它:

LoopInfo &li = getAnalysis<LoopInfo>()

这篇关于LLVM错误访问函数传递中的loopinfo的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！