Llvm 识别IR中的数组类型

我一直试图通过使用以下代码在IR中识别阵列访问：

  for (BasicBlock::iterator ii = BB->begin(), ii2; ii != BB->end(); ii++) {
     Instruction *I=ii;             
    if(GetElementPtrInst *getElePntr = dyn_cast<GetElementPtrInst>(&*I))
    {                   

        Value *valAlloc = (getElePntr->getOperand(0));

        if(getElePntr->getOperand(0)->getType()->isArrayTy())
            {
                errs()<<"\tarray found";
            }
    }  
 }  

for（基本块：：迭代器ii=BB->begin（），ii2；ii！=BB->end（）；ii++）{
指令*I=ii；
if（GetElementPtrInst*getElePntr=dyn_cast（&*I））
{                   
值*valAlloc=（getElePntr->getOperand（0））；
if（getElePntr->getOperator（0）->getType（）->isArray（））
{
errs（）GEP（
getelementptr
指令）的第一个操作数是指针，而不是数组。该指针可能指向数组，也可能不指向数组（请参见下文）。因此，您需要查看该指针指向的对象

  for (BasicBlock::iterator ii = BB->begin(), ii2; ii != BB->end(); ii++) {
     Instruction *I=ii;             
    if(GetElementPtrInst *getElePntr = dyn_cast<GetElementPtrInst>(&*I))
    {                   

        Value *valAlloc = (getElePntr->getOperand(0));

        if(getElePntr->getOperand(0)->getType()->isArrayTy())
            {
                errs()<<"\tarray found";
            }
    }  
 }  

下面是一个示例
BasicBlockPass
访客：

  for (BasicBlock::iterator ii = BB->begin(), ii2; ii != BB->end(); ii++) {
     Instruction *I=ii;             
    if(GetElementPtrInst *getElePntr = dyn_cast<GetElementPtrInst>(&*I))
    {                   

        Value *valAlloc = (getElePntr->getOperand(0));

        if(getElePntr->getOperand(0)->getType()->isArrayTy())
            {
                errs()<<"\tarray found";
            }
    }  
 }  

virtual bool runOnBasicBlock(BasicBlock &BB) {
    for (BasicBlock::iterator ii = BB.begin(), ii_e = BB.end(); ii != ii_e; ++ii) {
        if (GetElementPtrInst *gep = dyn_cast<GetElementPtrInst>(&*ii)) {
            // Dump the GEP instruction
            gep->dump();
            Value* firstOperand = gep->getOperand(0);
            Type* type = firstOperand->getType();

            // Figure out whether the first operand points to an array
            if (PointerType *pointerType = dyn_cast<PointerType>(type)) {
                Type* elementType = pointerType->getElementType();
                errs() << "The element type is: " << *elementType << "\n";

                if (elementType->isArrayTy()) {
                    errs() << "  .. points to an array!\n";
                }
            }
        }
    }

    return false;
}

你得到了IR：

  for (BasicBlock::iterator ii = BB->begin(), ii2; ii != BB->end(); ii++) {
     Instruction *I=ii;             
    if(GetElementPtrInst *getElePntr = dyn_cast<GetElementPtrInst>(&*I))
    {                   

        Value *valAlloc = (getElePntr->getOperand(0));

        if(getElePntr->getOperand(0)->getType()->isArrayTy())
            {
                errs()<<"\tarray found";
            }
    }  
 }  

define i32 @main(i32 %argc, i8** %argv) nounwind uwtable {
  %1 = alloca i32, align 4
  %2 = alloca i32, align 4
  %3 = alloca i8**, align 8
  store i32 0, i32* %1
  store i32 %argc, i32* %2, align 4
  store i8** %argv, i8*** %3, align 8
  %4 = load i8*** %3, align 8
  %5 = getelementptr inbounds i8** %4, i64 1
  %6 = load i8** %5
  %7 = getelementptr inbounds i8* %6, i64 8
  %8 = load i8* %7
  %9 = sext i8 %8 to i32
  ret i32 %9
}

虽然
argv
被视为数组，但编译器将其视为指针，因此看不到数组类型。我在上面粘贴的过程无法识别这里的数组，因为GEP的第一个操作数是指向指针的指针

  for (BasicBlock::iterator ii = BB->begin(), ii2; ii != BB->end(); ii++) {
     Instruction *I=ii;             
    if(GetElementPtrInst *getElePntr = dyn_cast<GetElementPtrInst>(&*I))
    {                   

        Value *valAlloc = (getElePntr->getOperand(0));

        if(getElePntr->getOperand(0)->getType()->isArrayTy())
            {
                errs()<<"\tarray found";
            }
    }  
 }