如何使用LLVM正确插入函数调用

Question

我试图设置一个传递，将插入一对全局变量以及一对在main开头的函数调用。然而，我相信我有正确设置功能描述的问题。我的代码可以编译，但是当我尝试运行pass时，我得到了这个错误:

void llvm::CallInst::init(llvm::Value*, llvm::ArrayRef<llvm::Value*>, const llvm::Twine&):         
Assertion `(Args.size() == FTy->getNumParams() || (FTy->isVarArg() && Args.size() > FTy- 
>getNumParams())) && "Calling a function with bad signature!"' failed. 

下面是我目前为止写的代码:

#include "llvm/IR/Instructions.h"
#include "llvm/Pass.h"
#include "llvm/Support/InstIterator.h"
#include "llvm/IR/Function.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Value.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Module.h"
using namespace llvm;
namespace{
struct fun_insert : public FunctionPass{
  static char ID;
  fun_insert():FunctionPass(ID){}
  virtual bool runOnFunction(Function &F){
    if (F.getName() == "main"){
      for (inst_iterator I = inst_begin(F), E= inst_end(F); I != E; ++I){               
        Instruction *inst = &*I;
        if(dyn_cast<AllocaInst> (inst)){
          errs() << "test" << "n";
          GlobalVariable *virtAddr = new GlobalVariable(*F.getParent(),
              Type::getInt8PtrTy(F.getContext()), false,
              GlobalValue::ExternalLinkage, 0, "virt_addr");
          virtAddr->setAlignment(4);                    
          Module *M = F.getParent();
          Constant *c = M->getOrInsertFunction("open",
              IntegerType::get(F.getContext(),32),
              PointerType::get(Type::getInt8PtrTy(F.getContext(), 8),8),
              IntegerType::get(F.getContext(),32), NULL);
          Function *open = cast<Function>(c);
          //ConstantInt *a = ConstantInt::get(M->getContext(), APInt(32, 9437184));
          IRBuilder<> builder(inst);
          Value *strPtr = builder.CreateGlobalStringPtr("/dev/mem", ".str");
          ConstantInt *a = builder.getInt32(9437184);
          //CallInst *openRet = builder.CreateCall2(open, strPtr, a, "open");
          builder.CreateCall2(open, strPtr, a, "open");
        }
        errs() << *inst <<"n"; 
      }
    }   
    return false;
  }
};
}

char fun_insert::ID=0;
static RegisterPass<fun_insert> 
X("fun_insert", "Insert Function Test", false, false);

谢谢你的帮助!

Answer 1

我相信我已经解决了这个问题。问题确实在于函数的声明和调用。我将代码调整如下:

Constant *c = M->getOrInsertFunction("open", 
    FunctionType::getInt32Ty(F.getContext()), 
    Type::getInt8PtrTy(F.getContext()), 
    Type::getInt32Ty(F.getContext()), 
    NULL);
Function *open = cast<Function>(c);
IRBuilder<> builder(inst);
Value *strPtr = builder.CreateGlobalStringPtr("/dev/mem", ".str");
ConstantInt *a = builder.getInt32(9437184);
builder.CreateCall2(open,strPtr,a);