// SysYIRGenerator.cpp
// TODO：类型转换及其检查
// TODO：sysy库函数处理
// TODO：数组处理
// TODO：对while、continue、break的测试
#include "IR.h"
#include <any>
#include <memory>
#include <iterator>
#include <sstream>
#include <string>
#include <vector>
#include "SysYIRGenerator.h"

using namespace std;
namespace sysy {


Type* SysYIRGenerator::buildArrayType(Type* baseType, const std::vector<Value*>& dims){
  Type* currentType = baseType;
    // 从最内层维度开始构建 ArrayType
    // 例如对于 int arr[2][3]，先处理 [3]，再处理 [2]
    // 注意：SysY 的 dims 是从最外层到最内层，所以我们需要反向迭代
    // 或者调整逻辑，使得从内到外构建 ArrayType
    // 假设 dims 列表是 [dim1, dim2, dim3...] (例如 [2, 3] for int[2][3])
    // 我们需要从最内层维度开始向外构建 ArrayType
    for (int i = dims.size() - 1; i >= 0; --i) {
        // 维度大小必须是常量，否则无法构建 ArrayType
        ConstantInteger* constDim = dynamic_cast<ConstantInteger*>(dims[i]);
        if (constDim == nullptr) {
            // 如果维度不是常量，可能需要特殊处理，例如将其视为指针
            // 对于函数参数 int arr[] 这种，第一个维度可以为未知
            // 在这里，我们假设所有声明的数组维度都是常量
            assert(false && "Array dimension must be a constant integer!");
            return nullptr;
        }
        unsigned dimSize = constDim->getInt();
        currentType = Type::getArrayType(currentType, dimSize);
    }
    return currentType;
}

Value* SysYIRGenerator::getGEPAddressInst(Value* basePointer, const std::vector<Value*>& indices) {
    // 检查 basePointer 是否为指针类型
    if (!basePointer->getType()->isPointer()) {
      assert(false && "GEP base pointer must be a pointer type!");
    }

    // 获取基指针所指向的实际类型 (例如 int* 指向 int, int[2][3]* 指向 int[2][3])
    Type* currentElementType = basePointer->getType()->as<PointerType>()->getBaseType();

    std::vector<Value*> actualGEPIndices;
    // GEP 指令的第一个索引通常是0，用于“跳过”基指针指向的聚合类型本身，直接指向其第一个元素。
    // 例如，对于 AllocaInst 返回的 `int[2][3]*`，第一个 `0` 索引表示从数组的开始而不是指针本身开始索引。
    actualGEPIndices.push_back(ConstantInteger::get(0));

    // 将用户提供的索引添加到 GEP 操作数中
    for (Value* index : indices) {
        actualGEPIndices.push_back(index);
    }

    // 根据索引链计算最终的元素类型
    Type* finalTargetType = currentElementType;

    // 遍历用户提供的索引（不包括我们添加的第一个0），逐步确定 GEP 的最终结果类型
    // 每个索引都“深入”一个维度
    for (int i = 0; i < indices.size(); ++i) { // 这里遍历的是用户提供的索引
        if (finalTargetType && finalTargetType->isArray()) {
            finalTargetType = finalTargetType->as<ArrayType>()->getElementType();
        } else {
            // 如果索引链还在继续，但当前类型已经不是数组或聚合类型，这通常是一个错误
            // 或者表示访问的是标量，后续索引无效。此时，finalTargetType 已经是最终的标量类型，不能再深入。
            // 例如，对 int arr[5]; 访问 arr[i][j] (j 是多余的)，这里会停止类型推断。
            break;
        }
    }

    // GEP 的结果总是指针类型，指向最终计算出的元素
    Type* gepResultType = Type::getPointerType(finalTargetType);

    // 创建 GEP 指令。假设 builder.createGetElementPtrInst 的签名为
    // (Type* resultType, Value* basePointer, const std::vector<Value*>& indices)
    return builder.createGetElementPtrInst(basePointer, actualGEPIndices);
}
/*
 * @brief: visit compUnit
 * @details:
 *      compUnit: (globalDecl | funcDef)+;
 */
std::any SysYIRGenerator::visitCompUnit(SysYParser::CompUnitContext *ctx) {
  // create the IR module
  auto pModule = new Module();
  assert(pModule);
  module.reset(pModule);

  // SymbolTable::ModuleScope scope(symbols_table);

  Utils::initExternalFunction(pModule, &builder);

  pModule->enterNewScope();
  visitChildren(ctx);
  pModule->leaveScope();
  return pModule;
}

std::any SysYIRGenerator::visitGlobalConstDecl(SysYParser::GlobalConstDeclContext *ctx){
  auto constDecl = ctx->constDecl();
  Type* type = std::any_cast<Type *>(visitBType(constDecl->bType()));
  for (const auto &constDef : constDecl->constDef()) {
    std::vector<Value *> dims = {};
    std::string name = constDef->Ident()->getText();
    auto constExps = constDef->constExp();
    if (!constExps.empty()) {
      for (const auto &constExp : constExps) {
        dims.push_back(std::any_cast<Value *>(visitConstExp(constExp)));
      }
    }

    ArrayValueTree* root = std::any_cast<ArrayValueTree *>(constDef->constInitVal()->accept(this));
    ValueCounter values;
    Utils::tree2Array(type, root, dims, dims.size(), values, &builder);
    delete root;
    // 创建全局常量变量，并更新符号表
    module->createConstVar(name, Type::getPointerType(type), values, dims);
  }
  return std::any();
}

std::any SysYIRGenerator::visitGlobalVarDecl(SysYParser::GlobalVarDeclContext *ctx) {
  auto varDecl = ctx->varDecl();
  Type* type = std::any_cast<Type *>(visitBType(varDecl->bType()));
  for (const auto &varDef : varDecl->varDef()) {
    std::vector<Value *> dims = {};
    std::string name = varDef->Ident()->getText();
    auto constExps = varDef->constExp();
    if (!constExps.empty()) {
      for (const auto &constExp : constExps) {
        dims.push_back(std::any_cast<Value *>(visitConstExp(constExp)));
      }
    }

    ValueCounter values = {};
    if (varDef->initVal() != nullptr) {
      ArrayValueTree* root = std::any_cast<ArrayValueTree *>(varDef->initVal()->accept(this));
      Utils::tree2Array(type, root, dims, dims.size(), values, &builder);
      delete root;
    }
    // 创建全局变量，并更新符号表
    module->createGlobalValue(name, Type::getPointerType(type), dims, values);
  }
  return std::any();
}

std::any SysYIRGenerator::visitConstDecl(SysYParser::ConstDeclContext *ctx){
  Type* type = std::any_cast<Type *>(visitBType(ctx->bType()));
  for (const auto constDef : ctx->constDef()) {
    std::vector<Value *> dims = {};
    std::string name = constDef->Ident()->getText();
    auto constExps = constDef->constExp();
    if (!constExps.empty()) {
      for (const auto constExp : constExps) {
        dims.push_back(std::any_cast<Value *>(visitConstExp(constExp)));
      }
    }

    ArrayValueTree* root = std::any_cast<ArrayValueTree *>(constDef->constInitVal()->accept(this));
    ValueCounter values;
    Utils::tree2Array(type, root, dims, dims.size(), values, &builder);
    delete root;

    module->createConstVar(name, Type::getPointerType(type), values, dims);
  }
  return 0;
}

std::any SysYIRGenerator::visitVarDecl(SysYParser::VarDeclContext *ctx) {
  Type* type = std::any_cast<Type *>(visitBType(ctx->bType()));
  for (const auto varDef : ctx->varDef()) {
    std::vector<Value *> dims = {};
    std::string name = varDef->Ident()->getText();
    auto constExps = varDef->constExp();
    if (!constExps.empty()) {
      for (const auto &constExp : constExps) {
        dims.push_back(std::any_cast<Value *>(visitConstExp(constExp)));
      }
    }

    Type* variableType = type;
    if (!dims.empty()) { // 如果有维度，说明是数组
        variableType = buildArrayType(type, dims); // 构建完整的 ArrayType
    }

    // 对于数组，alloca 的类型将是指针指向数组类型，例如 `int[2][3]*`
    // 对于标量，alloca 的类型将是指针指向标量类型，例如 `int*`
    AllocaInst* alloca =
        builder.createAllocaInst(Type::getPointerType(type), dims, name);

    if (varDef->initVal() != nullptr) {
      ValueCounter values;
      ArrayValueTree* root = std::any_cast<ArrayValueTree *>(varDef->initVal()->accept(this));
      Utils::tree2Array(type, root, dims, dims.size(), values, &builder);
      delete root;

      if (dims.empty()) { // 标量变量初始化
        builder.createStoreInst(values.getValue(0), alloca);
      } else { // 数组变量初始化
        const std::vector<sysy::Value *> &counterValues = values.getValues();

        int numElements = 1;
        std::vector<int> dimSizes;
        for (Value *dimVal : dims) {
          if (ConstantInteger *constInt = dynamic_cast<ConstantInteger *>(dimVal)) {
            int dimSize = constInt->getInt();
            numElements *= dimSize;
            dimSizes.push_back(dimSize);
          }
          // TODO else 错误处理：数组维度必须是常量（对于静态分配）
        }
        unsigned int elementSizeInBytes = type->getSize();
        unsigned int totalSizeInBytes = numElements * elementSizeInBytes;

        bool allValuesAreZero = false;
        if (counterValues.empty()) {
          allValuesAreZero = true;
        }
        else {
          allValuesAreZero = true;
          for (Value *val : counterValues){
            if (ConstantInteger *constInt = dynamic_cast<ConstantInteger *>(val)){
              if (constInt->getInt() != 0){
                allValuesAreZero = false;
                break;
              }
            }
            else{
              allValuesAreZero = false;
              break;
            }
          }
        }

        if (allValuesAreZero) {
          builder.createMemsetInst(
              alloca,
              ConstantInteger::get(0),
              ConstantInteger::get(totalSizeInBytes),
              ConstantInteger::get(0));
        }
        else {
          for (int k = 0; k < counterValues.size(); ++k) {
            std::vector<Value *> currentIndices;
            int tempLinearIndex = k;

            // 将线性索引转换为多维索引
            for (int dimIdx = dimSizes.size() - 1; dimIdx >= 0; --dimIdx)
            {
              currentIndices.insert(currentIndices.begin(),
                                    ConstantInteger::get(static_cast<int>(tempLinearIndex % dimSizes[dimIdx])));
              tempLinearIndex /= dimSizes[dimIdx];
            }

            // 计算元素的地址
            Value* elementAddress = getGEPAddressInst(alloca, currentIndices);
            // 生成 store 指令 (假设 createStoreInst 接受 Value* value, Value* pointer)
            builder.createStoreInst(counterValues[k], elementAddress);
          }
        }
      }
    }
    else { // 如果没有显式初始化值，默认对数组进行零初始化
      if (!dims.empty()) { // 只有数组才需要默认的零初始化
        int numElements = 1;
        for (Value *dimVal : dims) {
          if (ConstantInteger *constInt = dynamic_cast<ConstantInteger *>(dimVal)) {
            numElements *= constInt->getInt();
          }
        }
        unsigned int elementSizeInBytes = type->getSize();
        unsigned int totalSizeInBytes = numElements * elementSizeInBytes;

        builder.createMemsetInst(
            alloca,
            ConstantInteger::get(0),
            ConstantInteger::get(totalSizeInBytes),
            ConstantInteger::get(0)
          );
      }
    }

    module->addVariable(name, alloca);
  }

  return std::any();
}

std::any SysYIRGenerator::visitBType(SysYParser::BTypeContext *ctx) {
  return ctx->INT() != nullptr ? Type::getIntType() : Type::getFloatType();
}

std::any SysYIRGenerator::visitScalarInitValue(SysYParser::ScalarInitValueContext *ctx) {
  Value* value = std::any_cast<Value *>(visitExp(ctx->exp()));
  ArrayValueTree* result = new ArrayValueTree();
  result->setValue(value);
  return result;
}

std::any SysYIRGenerator::visitArrayInitValue(SysYParser::ArrayInitValueContext *ctx) {
  std::vector<ArrayValueTree *> children;
  for (const auto &initVal : ctx->initVal()) 
    children.push_back(std::any_cast<ArrayValueTree *>(initVal->accept(this)));
  ArrayValueTree* result = new ArrayValueTree();
  result->addChildren(children);
  return result;
}

std::any  SysYIRGenerator::visitConstScalarInitValue(SysYParser::ConstScalarInitValueContext *ctx) {
  Value* value = std::any_cast<Value *>(visitConstExp(ctx->constExp()));
  ArrayValueTree* result = new ArrayValueTree();
  result->setValue(value);
  return result;
}

std::any  SysYIRGenerator::visitConstArrayInitValue(SysYParser::ConstArrayInitValueContext *ctx) {
  std::vector<ArrayValueTree *> children;
  for (const auto &constInitVal : ctx->constInitVal()) 
    children.push_back(std::any_cast<ArrayValueTree *>(constInitVal->accept(this)));
  ArrayValueTree* result = new ArrayValueTree();
  result->addChildren(children);
  return result;
}

std::any SysYIRGenerator::visitFuncType(SysYParser::FuncTypeContext *ctx) {
  if (ctx->INT() != nullptr) 
    return Type::getIntType();
  if (ctx->FLOAT() != nullptr) 
    return Type::getFloatType();
  return Type::getVoidType();
}

std::any SysYIRGenerator::visitFuncDef(SysYParser::FuncDefContext *ctx){
  // 更新作用域
  module->enterNewScope();

  auto name = ctx->Ident()->getText();
  std::vector<Type *> paramTypes;
  std::vector<std::string> paramNames;
  std::vector<std::vector<Value *>> paramDims;

  if (ctx->funcFParams() != nullptr) {
    auto params = ctx->funcFParams()->funcFParam();
    for (const auto &param : params) {
      paramTypes.push_back(std::any_cast<Type *>(visitBType(param->bType())));
      paramNames.push_back(param->Ident()->getText());
      std::vector<Value *> dims = {};
      if (!param->LBRACK().empty()) {
        dims.push_back(ConstantInteger::get(-1)); // 第一个维度不确定
        for (const auto &exp : param->exp()) {
          dims.push_back(std::any_cast<Value *>(visitExp(exp)));
        }
      }
      paramDims.emplace_back(dims);
    }
  }

  Type* returnType = std::any_cast<Type *>(visitFuncType(ctx->funcType()));
  Type* funcType = Type::getFunctionType(returnType, paramTypes);
  Function* function = module->createFunction(name, funcType);
  BasicBlock* entry = function->getEntryBlock();
  builder.setPosition(entry, entry->end());

  for (int i = 0; i < paramTypes.size(); ++i) {
    AllocaInst* alloca = builder.createAllocaInst(Type::getPointerType(paramTypes[i]),
                                           paramDims[i], paramNames[i]);
    entry->insertArgument(alloca);
    module->addVariable(paramNames[i], alloca);
  }

  // 在处理函数体之前，创建一个新的基本块作为函数体的实际入口
  // 这样 entryBB 就可以在完成初始化后跳转到这里
  BasicBlock* funcBodyEntry = function->addBasicBlock("funcBodyEntry");
  
  // 从 entryBB 无条件跳转到 funcBodyEntry
  builder.createUncondBrInst(funcBodyEntry, {});
  builder.setPosition(funcBodyEntry,funcBodyEntry->end()); // 将插入点设置到 funcBodyEntry

  for (auto item : ctx->blockStmt()->blockItem()) {
    visitBlockItem(item);
  }

  // 如果函数没有显式的返回语句，且返回类型不是 void，则需要添加一个默认的返回值
  ReturnInst* retinst = nullptr;
  retinst = dynamic_cast<ReturnInst*>(builder.getBasicBlock()->terminator()->get());

  if (!retinst) {
    if (returnType->isVoid()) {
        builder.createReturnInst();
    } else if (returnType->isInt()) {
        builder.createReturnInst(ConstantInteger::get(0)); // 默认返回 0
    } else if (returnType->isFloat()) {
        builder.createReturnInst(ConstantFloating::get(0.0f)); // 默认返回 0.0f
    } else {
        assert(false && "Function with no explicit return and non-void type should return a value.");
    }
  }

  module->leaveScope();

  return std::any();
}

std::any SysYIRGenerator::visitBlockStmt(SysYParser::BlockStmtContext *ctx) {
  module->enterNewScope();
  for (auto item : ctx->blockItem()) 
    visitBlockItem(item);
  module->leaveScope();
  return 0;
}

std::any SysYIRGenerator::visitAssignStmt(SysYParser::AssignStmtContext *ctx) {
  auto lVal = ctx->lValue();
  std::string name = lVal->Ident()->getText();
  std::vector<Value *> dims;
  for (const auto &exp : lVal->exp()) {
    dims.push_back(std::any_cast<Value *>(visitExp(exp)));
  }
  
  auto variable = module->getVariable(name); // 获取 AllocaInst 或 GlobalValue
  Value* value = std::any_cast<Value *>(visitExp(ctx->exp())); // 右值

  if (variable == nullptr) {
      throw std::runtime_error("Variable " + name + " not found in assignment.");
  }

  // 计算最终赋值目标元素的类型
  // variable 本身应该是一个指针类型 (例如 int* 或 int[2][3]*)
  if (!variable->getType()->isPointer()) {
      assert(false && "Variable to be assigned must be a pointer type!");
      return std::any();
  }
  Type* targetElementType = variable->getType()->as<PointerType>()->getBaseType(); // 从基指针指向的类型开始

  // 模拟 GEP 路径，根据 dims 确定最终元素的类型
  for (int i = 0; i < dims.size(); ++i) {
      if (targetElementType && targetElementType->isArray()) {
          targetElementType = targetElementType->as<ArrayType>()->getElementType();
      } else {
          break; // 如果不是数组类型但还有索引，或者索引超出维度，则停止推断
      }
  }

  // 左值右值类型不同处理：根据最终元素类型进行转换
  if (targetElementType != value->getType()) {
    ConstantValue * constValue = dynamic_cast<ConstantValue *>(value);
    if (constValue != nullptr) {
      if (targetElementType == Type::getFloatType()) {
        value = ConstantFloating::get(static_cast<float>(constValue->getInt()));
      } else { // 假设如果不是浮点型，就是整型
        value = ConstantInteger::get(static_cast<int>(constValue->getFloat()));
      }
    } else {
      if (targetElementType == Type::getFloatType()) {
        value = builder.createIToFInst(value);
      } else { // 假设如果不是浮点型，就是整型
        value = builder.createFtoIInst(value);
      }
    }
  }

  // 计算目标地址：如果 dims 为空，就是变量本身地址；否则通过 GEP 计算
  Value* targetAddress = variable;
  if (!dims.empty()) {
    targetAddress = getGEPAddressInst(variable, dims);
  }

  builder.createStoreInst(value, targetAddress);

  return std::any();
}


std::any SysYIRGenerator::visitIfStmt(SysYParser::IfStmtContext *ctx) {
  // labels string stream

  std::stringstream labelstring;
  Function * function = builder.getBasicBlock()->getParent();

  BasicBlock* thenBlock = new BasicBlock(function);
  BasicBlock* exitBlock = new BasicBlock(function);

  if (ctx->stmt().size() > 1) {
    BasicBlock* elseBlock = new BasicBlock(function);

    builder.pushTrueBlock(thenBlock);
    builder.pushFalseBlock(elseBlock);
    // 访问条件表达式
    visitCond(ctx->cond());
    builder.popTrueBlock();
    builder.popFalseBlock();

    labelstring << "if_then.L" << builder.getLabelIndex();
    thenBlock->setName(labelstring.str());
    labelstring.str("");
    function->addBasicBlock(thenBlock);
    builder.setPosition(thenBlock, thenBlock->end());

    auto block = dynamic_cast<SysYParser::BlockStmtContext *>(ctx->stmt(0));
    // 如果是块语句，直接访问
    // 否则访问语句
    if (block != nullptr) {
      visitBlockStmt(block);
    } else {
      module->enterNewScope();
      ctx->stmt(0)->accept(this);
      module->leaveScope();
    }
    builder.createUncondBrInst(exitBlock, {});
    BasicBlock::conectBlocks(builder.getBasicBlock(), exitBlock);

    labelstring << "if_else.L" << builder.getLabelIndex();
    elseBlock->setName(labelstring.str());
    labelstring.str("");
    function->addBasicBlock(elseBlock);
    builder.setPosition(elseBlock, elseBlock->end());

    block = dynamic_cast<SysYParser::BlockStmtContext *>(ctx->stmt(1));
    if (block != nullptr) {
      visitBlockStmt(block);
    } else {
      module->enterNewScope();
      ctx->stmt(1)->accept(this);
      module->leaveScope();
    }
    builder.createUncondBrInst(exitBlock, {});
    BasicBlock::conectBlocks(builder.getBasicBlock(), exitBlock);

    labelstring << "if_exit.L" << builder.getLabelIndex();
    exitBlock->setName(labelstring.str());
    labelstring.str("");
    function->addBasicBlock(exitBlock);
    builder.setPosition(exitBlock, exitBlock->end());

  } else {
    builder.pushTrueBlock(thenBlock);
    builder.pushFalseBlock(exitBlock);
    visitCond(ctx->cond());
    builder.popTrueBlock();
    builder.popFalseBlock();

    labelstring << "if_then.L" << builder.getLabelIndex();
    thenBlock->setName(labelstring.str());
    labelstring.str("");
    function->addBasicBlock(thenBlock);
    builder.setPosition(thenBlock, thenBlock->end());

    auto block = dynamic_cast<SysYParser::BlockStmtContext *>(ctx->stmt(0));
    if (block != nullptr) {
      visitBlockStmt(block);
    } else {
      module->enterNewScope();
      ctx->stmt(0)->accept(this);
      module->leaveScope();
    }
    builder.createUncondBrInst(exitBlock, {});
    BasicBlock::conectBlocks(builder.getBasicBlock(), exitBlock);

    labelstring << "if_exit.L" << builder.getLabelIndex();
    exitBlock->setName(labelstring.str());
    labelstring.str("");
    function->addBasicBlock(exitBlock);
    builder.setPosition(exitBlock, exitBlock->end());
  }
  return std::any();
}

std::any SysYIRGenerator::visitWhileStmt(SysYParser::WhileStmtContext *ctx) {
  // while structure:
  // curblock -> headBlock -> bodyBlock -> exitBlock
  BasicBlock* curBlock = builder.getBasicBlock();
  Function* function = builder.getBasicBlock()->getParent();

  std::stringstream labelstring;
  labelstring << "while_head.L" << builder.getLabelIndex();
  BasicBlock *headBlock = function->addBasicBlock(labelstring.str());
  labelstring.str("");
  builder.createUncondBrInst(headBlock, {});
  BasicBlock::conectBlocks(curBlock, headBlock);
  builder.setPosition(headBlock, headBlock->end());

  BasicBlock* bodyBlock = new BasicBlock(function);
  BasicBlock* exitBlock = new BasicBlock(function);

  builder.pushTrueBlock(bodyBlock);
  builder.pushFalseBlock(exitBlock);
  // 访问条件表达式
  visitCond(ctx->cond());
  builder.popTrueBlock();
  builder.popFalseBlock();

  labelstring << "while_body.L" << builder.getLabelIndex();
  bodyBlock->setName(labelstring.str());
  labelstring.str("");
  function->addBasicBlock(bodyBlock);
  builder.setPosition(bodyBlock, bodyBlock->end());

  builder.pushBreakBlock(exitBlock);
  builder.pushContinueBlock(headBlock);
  
  auto block = dynamic_cast<SysYParser::BlockStmtContext *>(ctx->stmt());

  if( block != nullptr) {
    visitBlockStmt(block);
  } else {
    module->enterNewScope();
    ctx->stmt()->accept(this);
    module->leaveScope();
  }

  builder.createUncondBrInst(headBlock, {});
  BasicBlock::conectBlocks(builder.getBasicBlock(), exitBlock);
  builder.popBreakBlock();
  builder.popContinueBlock();

  labelstring << "while_exit.L" << builder.getLabelIndex();
  exitBlock->setName(labelstring.str());
  labelstring.str("");
  function->addBasicBlock(exitBlock);
  builder.setPosition(exitBlock, exitBlock->end());
  
  return std::any();
}

std::any SysYIRGenerator::visitBreakStmt(SysYParser::BreakStmtContext *ctx) {
  BasicBlock* breakBlock = builder.getBreakBlock();
  builder.createUncondBrInst(breakBlock, {});
  BasicBlock::conectBlocks(builder.getBasicBlock(), breakBlock);
  return std::any();
}

std::any SysYIRGenerator::visitContinueStmt(SysYParser::ContinueStmtContext *ctx) {
  BasicBlock* continueBlock = builder.getContinueBlock();
  builder.createUncondBrInst(continueBlock, {});
  BasicBlock::conectBlocks(builder.getBasicBlock(), continueBlock);
  return std::any();
}

std::any SysYIRGenerator::visitReturnStmt(SysYParser::ReturnStmtContext *ctx) {
  Value* returnValue = nullptr;
  if (ctx->exp() != nullptr) {
    returnValue = std::any_cast<Value *>(visitExp(ctx->exp()));
  }

  Type* funcType = builder.getBasicBlock()->getParent()->getReturnType();
    if (funcType!= returnValue->getType() && returnValue != nullptr) {
      ConstantValue * constValue = dynamic_cast<ConstantValue *>(returnValue);
      if (constValue != nullptr) {
        if (funcType == Type::getFloatType()) {
          returnValue = ConstantInteger::get(static_cast<float>(constValue->getInt()));
        } else {
          returnValue = ConstantFloating::get(static_cast<int>(constValue->getFloat()));
        }
      } else {
        if (funcType == Type::getFloatType()) {
          returnValue = builder.createIToFInst(returnValue);
        } else {
          returnValue = builder.createFtoIInst(returnValue);
        }
      }
    }
  builder.createReturnInst(returnValue);

  return std::any();
}


// SysYIRGenerator.cpp (修改部分)

std::any SysYIRGenerator::visitLValue(SysYParser::LValueContext *ctx) {
  std::string name = ctx->Ident()->getText();
  User* variable = module->getVariable(name);

  Value* value = nullptr;
  if (variable == nullptr) {
    throw std::runtime_error("Variable " + name + " not found.");
  }
  std::vector<Value *> dims;
  for (const auto &exp : ctx->exp()) {
    dims.push_back(std::any_cast<Value *>(visitExp(exp)));
  }

  // 1. 获取变量的声明维度数量
  unsigned declaredNumDims = 0;
  if (AllocaInst* alloc = dynamic_cast<AllocaInst*>(variable)) {
    declaredNumDims = alloc->getNumDims();
  } else if (GlobalValue* glob = dynamic_cast<GlobalValue*>(variable)) {
    declaredNumDims = glob->getNumDims();
  } else if (ConstantVariable* constV = dynamic_cast<ConstantVariable*>(variable)) {
    declaredNumDims = constV->getNumDims();
  }

  // 2. 处理常量变量 (ConstantVariable) 且所有索引都是常量的情况
  ConstantVariable* constVar = dynamic_cast<ConstantVariable *>(variable);
  if (constVar != nullptr) {
    bool allIndicesConstant = true;
    for (const auto &dim : dims) {
      if (dynamic_cast<ConstantValue *>(dim) == nullptr) {
        allIndicesConstant = false;
        break;
      }
    }
    if (allIndicesConstant) {
      // 如果是常量变量且所有索引都是常量，直接通过 getByIndices 获取编译时值
      // 这个方法会根据索引深度返回最终的标量值或指向子数组的指针 (作为 ConstantValue/Variable)
      return constVar->getByIndices(dims);
    }
  }

  // 3. 处理可变变量 (AllocaInst/GlobalValue) 或带非常量索引的常量变量
  // 这里区分标量访问和数组元素/子数组访问

  // 检查是否是访问标量变量本身（没有索引，且声明维度为0）
  if (dims.empty() && declaredNumDims == 0) {
    // 对于标量变量，直接加载其值。
    // variable 本身就是指向标量的指针 (e.g., int* %a)
    if (dynamic_cast<AllocaInst*>(variable) || dynamic_cast<GlobalValue*>(variable)) {
        value = builder.createLoadInst(variable);
    } else {
        // 如果走到这里且不是AllocaInst/GlobalValue，但dims为空且declaredNumDims为0，
        // 且又不是ConstantVariable (前面已处理)，则可能是错误情况。
        assert(false && "Unhandled scalar variable type in LValue access.");
        return static_cast<Value*>(nullptr);
    }
  } else {
    // 访问数组元素或子数组（有索引，或变量本身是数组/多维指针）
    Value* targetAddress = nullptr;

    // GEP 的基指针就是变量本身（它是一个指向内存的指针）
    if (dynamic_cast<AllocaInst*>(variable) || dynamic_cast<GlobalValue*>(variable) || (constVar != nullptr)) {
        // 允许对 ConstantVariable (如果它代表全局数组常量) 进行 GEP
        targetAddress = getGEPAddressInst(variable, dims);
    } else {
        // 其他情况（例如尝试对非指针类型或不支持的 LValue 进行 GEP）应报错
        assert(false && "LValue variable type not supported for GEP or dynamic load.");
        return static_cast<Value*>(nullptr);
    }

    // 现在 targetAddress 持有元素或子数组的地址。
    // 需要判断是加载值，还是返回子数组的地址。

    // 如果提供的索引数量少于声明的维度数量，则表示访问的是子数组，返回其地址
    if (dims.size() < declaredNumDims) {
        value = targetAddress;
    } else {
        // 否则，表示访问的是最终的标量元素，加载其值
        // 假设 createLoadInst 接受 Value* pointer
        value = builder.createLoadInst(targetAddress);
    }
  }
  return value;
}

std::any SysYIRGenerator::visitPrimaryExp(SysYParser::PrimaryExpContext *ctx) {
  if (ctx->exp() != nullptr) 
    return visitExp(ctx->exp());
  if (ctx->lValue() != nullptr) 
    return visitLValue(ctx->lValue());
  if (ctx->number() != nullptr) 
    return visitNumber(ctx->number());
  if (ctx->string() != nullptr) {
    cout << "String literal not supported in SysYIRGenerator." << endl;
  }
  return visitNumber(ctx->number());
}

std::any SysYIRGenerator::visitNumber(SysYParser::NumberContext *ctx) {
  if (ctx->ILITERAL() != nullptr) {
    int value = std::stol(ctx->ILITERAL()->getText(), nullptr, 0);
    return static_cast<Value *>(ConstantInteger::get(value));
  } else if (ctx->FLITERAL() != nullptr) {
    float value = std::stof(ctx->FLITERAL()->getText());
    return static_cast<Value *>(ConstantFloating::get(value));
  }
  throw std::runtime_error("Unknown number type.");
  return std::any(); // 不会到达这里
}

std::any SysYIRGenerator::visitCall(SysYParser::CallContext *ctx) {
  std::string funcName = ctx->Ident()->getText();
  Function *function = module->getFunction(funcName);
  if (function == nullptr) {
    function = module->getExternalFunction(funcName);
    if (function == nullptr) {
      std::cout << "The function " << funcName << " no defined." << std::endl;
      assert(function);
    }
  }

  std::vector<Value *> args = {};
  if (funcName == "starttime" || funcName == "stoptime") {
    // 如果是starttime或stoptime函数
    // TODO: 这里需要处理starttime和stoptime函数的参数
    // args.emplace_back()
  } else {
    if (ctx->funcRParams() != nullptr) {
      args = std::any_cast<std::vector<Value *>>(visitFuncRParams(ctx->funcRParams()));
    }

    auto params = function->getEntryBlock()->getArguments();
    for (int i = 0; i < args.size(); i++) {
      // 参数类型转换
      if (params[i]->getType() != args[i]->getType() &&
          (params[i]->getNumDims() != 0 ||
           params[i]->getType()->as<PointerType>()->getBaseType() != args[i]->getType())) {
        ConstantValue * constValue = dynamic_cast<ConstantValue *>(args[i]);
        if (constValue != nullptr) {
          if (params[i]->getType() == Type::getPointerType(Type::getFloatType())) {
            args[i] = ConstantInteger::get(static_cast<float>(constValue->getInt()));
          } else {
            args[i] = ConstantFloating::get(static_cast<int>(constValue->getFloat()));
          }
        } else {
          if (params[i]->getType() == Type::getPointerType(Type::getFloatType())) {
            args[i] = builder.createIToFInst(args[i]);
          } else {
            args[i] = builder.createFtoIInst(args[i]);
          }
        }
      }
    }
  }

  return static_cast<Value *>(builder.createCallInst(function, args));
}

std::any SysYIRGenerator::visitUnaryExp(SysYParser::UnaryExpContext *ctx) {
  if (ctx->primaryExp() != nullptr) 
    return visitPrimaryExp(ctx->primaryExp());
  if (ctx->call() != nullptr) 
    return visitCall(ctx->call());
  
  Value* value = std::any_cast<Value *>(visitUnaryExp(ctx->unaryExp()));
  Value* result = value;
  if (ctx->unaryOp()->SUB() != nullptr) {
    ConstantValue * constValue = dynamic_cast<ConstantValue *>(value);
    if (constValue != nullptr) {
      if (constValue->isFloat()) {
        result = ConstantFloating::get(-constValue->getFloat());
      } else {
        result = ConstantInteger::get(-constValue->getInt());
      }
    } else if (value != nullptr) {
      if (value->getType() == Type::getIntType()) {
        result = builder.createNegInst(value);
      } else {
        result = builder.createFNegInst(value);
      }
    } else {
      std::cout << "UnExp: value is nullptr." << std::endl;
      assert(false);
    }
  } else if (ctx->unaryOp()->NOT() != nullptr) {
    auto constValue = dynamic_cast<ConstantValue *>(value);
    if (constValue != nullptr) {
      if (constValue->isFloat()) {
        result =
            ConstantFloating::get(1 - (constValue->getFloat() != 0.0F ? 1 : 0));
      } else {
        result = ConstantInteger::get(1 - (constValue->getInt() != 0 ? 1 : 0));
      }
    } else if (value != nullptr) {
      if (value->getType() == Type::getIntType()) {
        result = builder.createNotInst(value);
      } else {
        result = builder.createFNotInst(value);
      }
    } else {
      std::cout << "UnExp: value is nullptr." << std::endl;
      assert(false);
    }
  }
  return result;
}

std::any SysYIRGenerator::visitFuncRParams(SysYParser::FuncRParamsContext *ctx) {
  std::vector<Value *> params;
  for (const auto &exp : ctx->exp()) 
    params.push_back(std::any_cast<Value *>(visitExp(exp)));
  return params;
}


std::any SysYIRGenerator::visitMulExp(SysYParser::MulExpContext *ctx) {
  Value * result = std::any_cast<Value *>(visitUnaryExp(ctx->unaryExp(0)));
 
  for (int i = 1; i < ctx->unaryExp().size(); i++) {
    auto opNode = dynamic_cast<antlr4::tree::TerminalNode*>(ctx->children[2*i-1]);
    int opType = opNode->getSymbol()->getType();

    Value* operand = std::any_cast<Value *>(visitUnaryExp(ctx->unaryExp(i)));

    Type* resultType = result->getType();
    Type* operandType = operand->getType();
    Type* floatType = Type::getFloatType();

    if (resultType == floatType || operandType == floatType) {
      // 如果有一个操作数是浮点数，则将两个操作数都转换为浮点数
      if (operandType != floatType) {
        ConstantValue * constValue = dynamic_cast<ConstantValue *>(operand);
        if (constValue != nullptr) 
          operand = ConstantFloating::get(static_cast<float>(constValue->getInt()));
        else 
          operand = builder.createIToFInst(operand);
      } else if (resultType != floatType) {
        ConstantValue* constResult = dynamic_cast<ConstantValue *>(result);
        if (constResult != nullptr) 
          result = ConstantFloating::get(static_cast<float>(constResult->getInt()));
         else 
          result = builder.createIToFInst(result);
      }

      ConstantValue* constResult = dynamic_cast<ConstantValue *>(result);
      ConstantValue* constOperand = dynamic_cast<ConstantValue *>(operand);
      if (opType == SysYParser::MUL) {
        if ((constOperand != nullptr) && (constResult != nullptr)) {
          result = ConstantFloating::get(constResult->getFloat() *
                                      constOperand->getFloat());
        } else {
          result = builder.createFMulInst(result, operand);
        }
      } else if (opType == SysYParser::DIV) {
        if ((constOperand != nullptr) && (constResult != nullptr)) {
          result = ConstantFloating::get(constResult->getFloat() /
                                      constOperand->getFloat());
        } else {
          result = builder.createFDivInst(result, operand);
        }
      } else {
        // float类型的取模操作不允许
        std::cout << "MulExp: float type mod operation is not allowed." << std::endl;
        assert(false);
      }
    } else {
      ConstantValue * constResult = dynamic_cast<ConstantValue *>(result);
      ConstantValue * constOperand = dynamic_cast<ConstantValue *>(operand);
      if (opType == SysYParser::MUL) {
        if ((constOperand != nullptr) && (constResult != nullptr)) 
          result = ConstantInteger::get(constResult->getInt() * constOperand->getInt());
        else 
          result = builder.createMulInst(result, operand);
      } else if (opType == SysYParser::DIV) {
        if ((constOperand != nullptr) && (constResult != nullptr)) 
          result = ConstantInteger::get(constResult->getInt() / constOperand->getInt());
         else 
          result = builder.createDivInst(result, operand);
      } else {
        if ((constOperand != nullptr) && (constResult != nullptr)) 
          result = ConstantInteger::get(constResult->getInt() % constOperand->getInt());
         else 
          result = builder.createRemInst(result, operand);
      }
    }
  }

  return result;
}


std::any SysYIRGenerator::visitAddExp(SysYParser::AddExpContext *ctx) {
  Value* result = std::any_cast<Value *>(visitMulExp(ctx->mulExp(0)));

  for (int i = 1; i < ctx->mulExp().size(); i++) {
    auto opNode = dynamic_cast<antlr4::tree::TerminalNode*>(ctx->children[2*i-1]);
    int opType = opNode->getSymbol()->getType();

    Value* operand = std::any_cast<Value *>(visitMulExp(ctx->mulExp(i)));
    Type* resultType = result->getType();
    Type* operandType = operand->getType();
    Type* floatType = Type::getFloatType();

    if (resultType == floatType || operandType == floatType) {
      // 类型转换
      if (operandType != floatType) {
        ConstantValue * constOperand = dynamic_cast<ConstantValue *>(operand);
        if (constOperand != nullptr) 
          operand = ConstantFloating::get(static_cast<float>(constOperand->getInt()));
        else 
          operand = builder.createIToFInst(operand);
      } else if (resultType != floatType) {
        ConstantValue * constResult = dynamic_cast<ConstantValue *>(result);
        if (constResult != nullptr) 
          result = ConstantFloating::get(static_cast<float>(constResult->getInt()));
        else 
          result = builder.createIToFInst(result);
      }

      ConstantValue *  constResult = dynamic_cast<ConstantValue *>(result);
      ConstantValue *  constOperand = dynamic_cast<ConstantValue *>(operand);
      if (opType == SysYParser::ADD) {
        if ((constResult != nullptr) && (constOperand != nullptr))
          result = ConstantFloating::get(constResult->getFloat() + constOperand->getFloat());
        else 
          result = builder.createFAddInst(result, operand);
      } else {
        if ((constResult != nullptr) && (constOperand != nullptr)) 
          result = ConstantFloating::get(constResult->getFloat() - constOperand->getFloat());
        else
          result = builder.createFSubInst(result, operand);
      }
    } else {
      ConstantValue *  constResult = dynamic_cast<ConstantValue *>(result);
      ConstantValue *  constOperand = dynamic_cast<ConstantValue *>(operand);
      if (opType == SysYParser::ADD) {
        if ((constResult != nullptr) && (constOperand != nullptr))
          result = ConstantInteger::get(constResult->getInt() + constOperand->getInt());
        else 
          result = builder.createAddInst(result, operand);
      } else {
        if ((constResult != nullptr) && (constOperand != nullptr))
          result = ConstantInteger::get(constResult->getInt() - constOperand->getInt());
        else 
          result = builder.createSubInst(result, operand);
      }
    }
  }

  return result;
}

std::any SysYIRGenerator::visitRelExp(SysYParser::RelExpContext *ctx) {
  Value* result = std::any_cast<Value *>(visitAddExp(ctx->addExp(0)));

  for (int i = 1; i < ctx->addExp().size(); i++) {
    auto opNode = dynamic_cast<antlr4::tree::TerminalNode*>(ctx->children[2*i-1]);
    int opType = opNode->getSymbol()->getType();

    Value* operand = std::any_cast<Value *>(visitAddExp(ctx->addExp(i)));

    Type* resultType = result->getType();
    Type* operandType = operand->getType();

    ConstantValue* constResult = dynamic_cast<ConstantValue *>(result);
    ConstantValue* constOperand = dynamic_cast<ConstantValue *>(operand);

    // 常量比较
    if ((constResult != nullptr) && (constOperand != nullptr)) {
      auto operand1 = constResult->isFloat() ? constResult->getFloat()
                                             : constResult->getInt();
      auto operand2 = constOperand->isFloat() ? constOperand->getFloat()
                                              : constOperand->getInt();

      if (opType == SysYParser::LT)      result = ConstantInteger::get(operand1 < operand2 ? 1 : 0);
      else if (opType == SysYParser::GT) result = ConstantInteger::get(operand1 > operand2 ? 1 : 0);
      else if (opType == SysYParser::LE) result = ConstantInteger::get(operand1 <= operand2 ? 1 : 0);
      else if (opType == SysYParser::GE) result = ConstantInteger::get(operand1 >= operand2 ? 1 : 0);
      else                          assert(false);

    } else {
      Type* resultType = result->getType();
      Type* operandType = operand->getType();
      Type* floatType = Type::getFloatType();

      // 浮点数处理
      if (resultType == floatType || operandType == floatType) {
        if (resultType != floatType) {
          if (constResult != nullptr)
            result = ConstantFloating::get(static_cast<float>(constResult->getInt()));
          else 
            result = builder.createIToFInst(result);
          
        }
        if (operandType != floatType) {
          if (constOperand != nullptr) 
            operand = ConstantFloating::get(static_cast<float>(constOperand->getInt()));
          else 
            operand = builder.createIToFInst(operand);
          
        }

        if (opType == SysYParser::LT)      result = builder.createFCmpLTInst(result, operand);
        else if (opType == SysYParser::GT) result = builder.createFCmpGTInst(result, operand);
        else if (opType == SysYParser::LE) result = builder.createFCmpLEInst(result, operand);
        else if (opType == SysYParser::GE) result = builder.createFCmpGEInst(result, operand);
        else                          assert(false);

      } else {
        // 整数处理
        if (opType == SysYParser::LT)      result = builder.createICmpLTInst(result, operand);
        else if (opType == SysYParser::GT) result = builder.createICmpGTInst(result, operand);
        else if (opType == SysYParser::LE) result = builder.createICmpLEInst(result, operand);
        else if (opType == SysYParser::GE) result = builder.createICmpGEInst(result, operand);
        else                          assert(false);

      }
    }
  }

  return result;
}


std::any SysYIRGenerator::visitEqExp(SysYParser::EqExpContext *ctx) {
  Value * result = std::any_cast<Value *>(visitRelExp(ctx->relExp(0)));

  for (int i = 1; i < ctx->relExp().size(); i++) {
    auto opNode = dynamic_cast<antlr4::tree::TerminalNode*>(ctx->children[2*i-1]);
    int opType = opNode->getSymbol()->getType();

    Value * operand = std::any_cast<Value *>(visitRelExp(ctx->relExp(i)));

    ConstantValue* constResult = dynamic_cast<ConstantValue *>(result);
    ConstantValue* constOperand = dynamic_cast<ConstantValue *>(operand);

    if ((constResult != nullptr) && (constOperand != nullptr)) {
      auto operand1 = constResult->isFloat() ? constResult->getFloat()
                                             : constResult->getInt();
      auto operand2 = constOperand->isFloat() ? constOperand->getFloat()
                                              : constOperand->getInt();

      if (opType == SysYParser::EQ)      result = ConstantInteger::get(operand1 == operand2 ? 1 : 0);
      else if (opType == SysYParser::NE) result = ConstantInteger::get(operand1 != operand2 ? 1 : 0);
      else                          assert(false);
      
    } else {
      Type* resultType = result->getType();
      Type* operandType = operand->getType();
      Type* floatType = Type::getFloatType();

      if (resultType == floatType || operandType == floatType) {
        if (resultType != floatType) {
          if (constResult != nullptr)
            result = ConstantFloating::get(static_cast<float>(constResult->getInt()));
          else 
            result = builder.createIToFInst(result);
        }
        if (operandType != floatType) {
          if (constOperand != nullptr) 
            operand = ConstantFloating::get(static_cast<float>(constOperand->getInt()));
          else
            operand = builder.createIToFInst(operand);
        }

        if (opType == SysYParser::EQ)      result = builder.createFCmpEQInst(result, operand);
        else if (opType == SysYParser::NE) result = builder.createFCmpNEInst(result, operand);
        else                          assert(false);

      } else {

        if (opType == SysYParser::EQ)      result = builder.createICmpEQInst(result, operand);
        else if (opType == SysYParser::NE) result = builder.createICmpNEInst(result, operand);
        else                          assert(false);

      }
    }
  }

  if (ctx->relExp().size() == 1) {
    ConstantValue * constResult = dynamic_cast<ConstantValue *>(result);
    // 如果只有一个关系表达式，则将结果转换为0或1
    if (constResult != nullptr) {
      if (constResult->isFloat()) 
        result = ConstantInteger::get(constResult->getFloat() != 0.0F ? 1 : 0);
      else
        result = ConstantInteger::get(constResult->getInt() != 0 ? 1 : 0);
    }
  }

  return result;
}

std::any SysYIRGenerator::visitLAndExp(SysYParser::LAndExpContext *ctx){
  std::stringstream labelstring;
  BasicBlock *curBlock = builder.getBasicBlock();
  Function *function = builder.getBasicBlock()->getParent();
  BasicBlock *trueBlock = builder.getTrueBlock();
  BasicBlock *falseBlock = builder.getFalseBlock();
  auto conds = ctx->eqExp();

  for (int i = 0; i < conds.size() - 1; i++) {

    labelstring << "AND.L" << builder.getLabelIndex();
    BasicBlock *newtrueBlock = function->addBasicBlock(labelstring.str());
    labelstring.str("");

    auto cond = std::any_cast<Value *>(visitEqExp(ctx->eqExp(i)));
    builder.createCondBrInst(cond, newtrueBlock, falseBlock, {}, {});

    BasicBlock::conectBlocks(curBlock, newtrueBlock);
    BasicBlock::conectBlocks(curBlock, falseBlock);

    curBlock = newtrueBlock;
    builder.setPosition(curBlock, curBlock->end());
  }

  auto cond = std::any_cast<Value *>(visitEqExp(conds.back()));
  builder.createCondBrInst(cond, trueBlock, falseBlock, {}, {});

  BasicBlock::conectBlocks(curBlock, trueBlock);
  BasicBlock::conectBlocks(curBlock, falseBlock);

  return std::any();
}

auto SysYIRGenerator::visitLOrExp(SysYParser::LOrExpContext *ctx) -> std::any {
  std::stringstream labelstring;
  BasicBlock *curBlock = builder.getBasicBlock();
  Function *function = curBlock->getParent();
  auto conds = ctx->lAndExp();

  for (int i = 0; i < conds.size() - 1; i++) {
    labelstring << "OR.L" << builder.getLabelIndex();
    BasicBlock *newFalseBlock = function->addBasicBlock(labelstring.str());
    labelstring.str("");

    builder.pushFalseBlock(newFalseBlock);
    visitLAndExp(ctx->lAndExp(i));
    builder.popFalseBlock();

    builder.setPosition(newFalseBlock, newFalseBlock->end());
  }

  visitLAndExp(conds.back());

  return std::any();
}

void Utils::tree2Array(Type *type, ArrayValueTree *root,
                        const std::vector<Value *> &dims, unsigned numDims,
                        ValueCounter &result, IRBuilder *builder) {
  Value* value = root->getValue();
  auto &children = root->getChildren();
  // 类型转换
  if (value != nullptr) {
    if (type == value->getType()) {
      result.push_back(value);
    } else {
      if (type == Type::getFloatType()) {
        ConstantValue* constValue = dynamic_cast<ConstantValue *>(value);
        if (constValue != nullptr)
          result.push_back(ConstantFloating::get(static_cast<float>(constValue->getInt())));
        else 
          result.push_back(builder->createIToFInst(value));
        
      } else {
        ConstantValue* constValue = dynamic_cast<ConstantValue *>(value);
        if (constValue != nullptr)
          result.push_back(ConstantInteger::get(static_cast<int>(constValue->getFloat())));
        else 
          result.push_back(builder->createFtoIInst(value));
        
      }
    }
    return;
  }

  auto beforeSize = result.size();
  for (const auto &child : children) {
    int begin = result.size();
    int newNumDims = 0;
    for (unsigned i = 0; i < numDims - 1; i++) {
      auto dim = dynamic_cast<ConstantValue *>(*(dims.rbegin() + i))->getInt();
      if (begin % dim == 0) {
        newNumDims += 1;
        begin /= dim;
      } else {
        break;
      }
    }
    tree2Array(type, child.get(), dims, newNumDims, result, builder);
  }
  auto afterSize = result.size();

  int blockSize = 1;
  for (unsigned i = 0; i < numDims; i++) {
    blockSize *= dynamic_cast<ConstantValue *>(*(dims.rbegin() + i))->getInt();
  }

  int num = blockSize - afterSize + beforeSize;
  if (num > 0) {
    if (type == Type::getFloatType())
      result.push_back(ConstantFloating::get(0.0F), num);
    else 
      result.push_back(ConstantInteger::get(0), num);
  }
}

void Utils::createExternalFunction(
    const std::vector<Type *> &paramTypes,
    const std::vector<std::string> &paramNames,
    const std::vector<std::vector<Value *>> &paramDims, Type *returnType,
    const std::string &funcName, Module *pModule, IRBuilder *pBuilder) {
  auto funcType = Type::getFunctionType(returnType, paramTypes);
  auto function = pModule->createExternalFunction(funcName, funcType);
  auto entry = function->getEntryBlock();
  pBuilder->setPosition(entry, entry->end());

  for (int i = 0; i < paramTypes.size(); ++i) {
    auto alloca = pBuilder->createAllocaInst(
        Type::getPointerType(paramTypes[i]), paramDims[i], paramNames[i]);
    entry->insertArgument(alloca);
    // pModule->addVariable(paramNames[i], alloca);
  }
}

void Utils::initExternalFunction(Module *pModule, IRBuilder *pBuilder) {
  std::vector<Type *> paramTypes;
  std::vector<std::string> paramNames;
  std::vector<std::vector<Value *>> paramDims;
  Type *returnType;
  std::string funcName;

  returnType = Type::getIntType();
  funcName = "getint";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);
  funcName = "getch";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);
  paramTypes.push_back(Type::getIntType());
  paramNames.emplace_back("x");
  paramDims.push_back(std::vector<Value *>{ConstantInteger::get(-1)});
  funcName = "getarray";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);

  returnType = Type::getFloatType();
  paramTypes.clear();
  paramNames.clear();
  paramDims.clear();
  funcName = "getfloat";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);

  returnType = Type::getIntType();
  paramTypes.push_back(Type::getFloatType());
  paramNames.emplace_back("x");
  paramDims.push_back(std::vector<Value *>{ConstantInteger::get(-1)});
  funcName = "getfarray";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);

  returnType = Type::getVoidType();

  paramTypes.clear();
  paramTypes.push_back(Type::getIntType());
  paramDims.clear();
  paramDims.emplace_back();
  funcName = "putint";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);

  funcName = "putch";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);

  paramTypes.clear();
  paramTypes.push_back(Type::getIntType());
  paramTypes.push_back(Type::getIntType());
  paramDims.clear();
  paramDims.emplace_back();
  paramDims.push_back(std::vector<Value *>{ConstantInteger::get(-1)});
  paramNames.clear();
  paramNames.emplace_back("n");
  paramNames.emplace_back("a");
  funcName = "putarray";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);

  paramTypes.clear();
  paramTypes.push_back(Type::getFloatType());
  paramDims.clear();
  paramDims.emplace_back();
  paramNames.clear();
  paramNames.emplace_back("a");
  funcName = "putfloat";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);

  paramTypes.clear();
  paramTypes.push_back(Type::getIntType());
  paramTypes.push_back(Type::getFloatType());
  paramDims.clear();
  paramDims.emplace_back();
  paramDims.push_back(std::vector<Value *>{ConstantInteger::get(-1)});
  paramNames.clear();
  paramNames.emplace_back("n");
  paramNames.emplace_back("a");
  funcName = "putfarray";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);

  paramTypes.clear();
  paramTypes.push_back(Type::getIntType());
  paramDims.clear();
  paramDims.emplace_back();
  paramNames.clear();
  paramNames.emplace_back("__LINE__");
  funcName = "starttime";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);

  paramTypes.clear();
  paramTypes.push_back(Type::getIntType());
  paramDims.clear();
  paramDims.emplace_back();
  paramNames.clear();
  paramNames.emplace_back("__LINE__");
  funcName = "stoptime";
  Utils::createExternalFunction(paramTypes, paramNames, paramDims, returnType,
                                 funcName, pModule, pBuilder);

}

} // namespace sysy