diff --git a/src/SysYIRGenerator.cpp b/src/SysYIRGenerator.cpp
index 3eccc14..94e7640 100644
--- a/src/SysYIRGenerator.cpp
+++ b/src/SysYIRGenerator.cpp
@@ -6,18 +6,346 @@ using namespace std;
 
 namespace sysy {
 
-any SysYIRGenerator::visitCompUnit(SysYParser::CompUnitContext *ctx) {
+/*
+ * @brief: visit compUnit
+ * @details:
+ *      compUnit: (decl | 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);
+
+  // 待添加运行时库函数getint等
   // generates globals and functions
+  
   visitChildren(ctx);
   // return the IR module
   return pModule;
 }
-std::any
-SysYIRGenerator::visitFuncRParams(SysYParser::FuncRParamsContext *ctx) {
+
+/*
+ * @brief: visit decl
+ * @details:
+ *      decl: constDecl | varDecl;
+ *      constDecl: CONST bType constDef (COMMA constDef)* SEMI;
+ *      varDecl: bType varDef (COMMA varDef)* SEMI;
+ * constDecl and varDecl shares similar syntax structure
+ * we consider them together? not sure
+ */
+std::any SysYIRGenerator::visitDecl(SysYParser::DeclContext *ctx) {
+  if(ctx->constDecl()){
+    return visitConstDecl(ctx->constDecl());
+  }else if(ctx->varDecl()){
+    return visitVarDecl(ctx->varDecl());
+  }
+  return nullptr;
+}
+
+/*
+ * @brief: visit constdecl
+ * @details:
+ *      constDecl: CONST bType constDef (COMMA constDef)* SEMI;
+ */
+std::any SysYIRGenerator::visitConstDecl(SysYParser::ConstDeclContext *ctx) {
+  auto type = Type::getPointerType(any_cast<Type *>(ctx->bType()->accept(this)));
+  if(symbols_table.isModuleScope())
+    visitConstGlobalDecl(ctx, type);
+  else
+    visitConstLocalDecl(ctx, type);
+  return std::any();
+}
+
+/*
+ * @brief: visit btype
+ * @details:
+ *      bType: INT | FLOAT;
+ */
+std::any SysYIRGenerator::visitBType(SysYParser::BTypeContext *ctx) {
+  return ctx->INT() ? Type::getIntType() : Type::getFloatType();
+}
+
+// std::any visitConstDef(SysYParser::ConstDefContext *ctx);
+
+std::any SysYIRGenerator::visitConstGlobalDecl(SysYParser::ConstDeclContext *ctx, Type* type) {
+  std::vector<Value *> values;
+  for (auto constDef : ctx->constDef()) {
+
+    auto name = constDef->Ident()->getText();
+    // get its dimensions
+    vector<Value *> dims;
+    for (auto dim : constDef->constExp())
+      dims.push_back(any_cast<Value *>(dim->accept(this)));
+    
+    if (dims.size() == 0) {
+      auto init = constDef->ASSIGN() ? any_cast<Value *>((constDef->constInitVal()->constExp()->accept(this)))
+                                     : nullptr;
+      if (init && isa<ConstantValue>(init)){
+        Type *btype = type->as<PointerType>()->getBaseType();
+        if (btype->isInt() && init->getType()->isFloat())
+          init = ConstantValue::get((int)dynamic_cast<ConstantValue *>(init)->getFloat());
+        else if (btype->isFloat() && init->getType()->isInt())
+          init = ConstantValue::get((float)dynamic_cast<ConstantValue *>(init)->getInt());
+      }
+
+      auto global_value = module->createGlobalValue(name, type, dims, init);
+      
+      symbols_table.insert(name, global_value);
+      values.push_back(global_value);
+    }
+    else{
+      auto init = constDef->ASSIGN() ? any_cast<Value *>(dims[0])
+                                     : nullptr;
+      auto global_value = module->createGlobalValue(name, type, dims, init);
+      if (constDef->ASSIGN()) {
+        d = 0;
+        n = 0;
+        path.clear();
+        path = vector<int>(dims.size(), 0);
+        isalloca = false;
+        current_type = global_value->getType()->as<PointerType>()->getBaseType();
+        current_global = global_value;
+        numdims = global_value->getNumDims();
+        for (auto init : constDef->constInitVal()->constInitVal())
+          init->accept(this);  
+        // visitConstInitValue(init);
+      }
+      symbols_table.insert(name, global_value);
+      values.push_back(global_value);
+    }
+  }
+  return values;
+}
+
+std::any SysYIRGenerator::visitVarGlobalDecl(SysYParser::VarDeclContext *ctx, Type* type){
+  std::vector<Value *> values;
+  for (auto varDef : ctx->varDef()) {
+
+    auto name = varDef->Ident()->getText();
+    // get its dimensions
+    vector<Value *> dims;
+    for (auto dim : varDef->constExp())
+      dims.push_back(any_cast<Value *>(dim->accept(this)));
+    
+    if (dims.size() == 0) {
+      auto init = varDef->ASSIGN() ? any_cast<Value *>((varDef->initVal()->exp()->accept(this)))
+                                     : nullptr;
+      if (init && isa<ConstantValue>(init)){
+        Type *btype = type->as<PointerType>()->getBaseType();
+        if (btype->isInt() && init->getType()->isFloat())
+          init = ConstantValue::get((int)dynamic_cast<ConstantValue *>(init)->getFloat());
+        else if (btype->isFloat() && init->getType()->isInt())
+          init = ConstantValue::get((float)dynamic_cast<ConstantValue *>(init)->getInt());
+      }
+
+      auto global_value = module->createGlobalValue(name, type, dims, init);
+      
+      symbols_table.insert(name, global_value);
+      values.push_back(global_value);
+    }
+    else{
+      auto init = varDef->ASSIGN() ? any_cast<Value *>(dims[0])
+                                     : nullptr;
+      auto global_value = module->createGlobalValue(name, type, dims, init);
+      if (varDef->ASSIGN()) {
+        d = 0;
+        n = 0;
+        path.clear();
+        path = vector<int>(dims.size(), 0);
+        isalloca = false;
+        current_type = global_value->getType()->as<PointerType>()->getBaseType();
+        current_global = global_value;
+        numdims = global_value->getNumDims();
+        for (auto init : varDef->initVal()->initVal())
+          init->accept(this);  
+        // visitInitValue(init);
+      }
+      symbols_table.insert(name, global_value);
+      values.push_back(global_value);
+    }
+  }
+  return values;
+}
+
+std::any SysYIRGenerator::visitConstLocalDecl(SysYParser::ConstDeclContext *ctx, Type* type){
+  std::vector<Value *> values;
+    // handle variables
+  for (auto constDef : ctx->constDef()) {
+    
+    auto name = constDef->Ident()->getText();
+    vector<Value *> dims;
+    for (auto dim : constDef->constExp())
+      dims.push_back(any_cast<Value *>(dim->accept(this)));
+    auto alloca = builder.createAllocaInst(type, dims, name);
+    symbols_table.insert(name, alloca);
+
+    if (constDef->ASSIGN()) {
+      if (alloca->getNumDims() == 0) {
+
+        auto value = any_cast<Value *>(constDef->constInitVal()->constExp()->accept(this));
+        
+        if (isa<ConstantValue>(value)) {
+          if (ctx->bType()->INT() && dynamic_cast<ConstantValue *>(value)->isFloat())
+            value = ConstantValue::get((int)dynamic_cast<ConstantValue *>(value)->getFloat());
+          else if (ctx->bType()->FLOAT() && dynamic_cast<ConstantValue *>(value)->isInt())
+            value = ConstantValue::get((float)dynamic_cast<ConstantValue *>(value)->getInt());
+        }
+        else if (alloca->getType()->as<PointerType>()->getBaseType()->isInt() && value->getType()->isFloat())
+          value = builder.createFtoIInst(value);
+        else if (alloca->getType()->as<PointerType>()->getBaseType()->isFloat() && value->getType()->isInt())
+          value = builder.createIToFInst(value);
+        
+        auto store = builder.createStoreInst(value, alloca);
+      }
+      else{
+        d = 0;
+        n = 0;
+        path.clear();
+        path = vector<int>(alloca->getNumDims(), 0);
+        isalloca = true;
+        current_alloca = alloca;
+        current_type = alloca->getType()->as<PointerType>()->getBaseType();
+        numdims = alloca->getNumDims();
+        for (auto init : constDef->constInitVal()->constInitVal())
+          init->accept(this);
+      }
+    }
+
+    values.push_back(alloca);
+  }
+  return values;
+}
+
+std::any SysYIRGenerator::visitVarLocalDecl(SysYParser::VarDeclContext *ctx, Type* type){
+  std::vector<Value *> values;
+  for (auto varDef : ctx->varDef()) {
+    
+    auto name = varDef->Ident()->getText();
+    vector<Value *> dims;
+    for (auto dim : varDef->constExp())
+      dims.push_back(any_cast<Value *>(dim->accept(this)));
+    auto alloca = builder.createAllocaInst(type, dims, name);
+    symbols_table.insert(name, alloca);
+
+    if (varDef->ASSIGN()) {
+      if (alloca->getNumDims() == 0) {
+
+        auto value = any_cast<Value *>(varDef->initVal()->exp()->accept(this));
+        
+        if (isa<ConstantValue>(value)) {
+          if (ctx->bType()->INT() && dynamic_cast<ConstantValue *>(value)->isFloat())
+            value = ConstantValue::get((int)dynamic_cast<ConstantValue *>(value)->getFloat());
+          else if (ctx->bType()->FLOAT() && dynamic_cast<ConstantValue *>(value)->isInt())
+            value = ConstantValue::get((float)dynamic_cast<ConstantValue *>(value)->getInt());
+        }
+        else if (alloca->getType()->as<PointerType>()->getBaseType()->isInt() && value->getType()->isFloat())
+          value = builder.createFtoIInst(value);
+        else if (alloca->getType()->as<PointerType>()->getBaseType()->isFloat() && value->getType()->isInt())
+          value = builder.createIToFInst(value);
+        
+        auto store = builder.createStoreInst(value, alloca);
+      }
+      else{
+        d = 0;
+        n = 0;
+        path.clear();
+        path = vector<int>(alloca->getNumDims(), 0);
+        isalloca = true;
+        current_alloca = alloca;
+        current_type = alloca->getType()->as<PointerType>()->getBaseType();
+        numdims = alloca->getNumDims();
+        for (auto init : varDef->initVal()->initVal())
+          init->accept(this);
+      }
+    }
+    
+    values.push_back(alloca);
+  }
+  return values;
+}
+
+
+
+/*
+ * @brief: visit constInitVal
+ * @details:
+ *      constInitVal: constExp
+ *		              | LBRACE (constInitVal (COMMA constInitVal)*)? RBRACE;
+ */
+std::any visitConstInitVal(SysYParser::ConstInitValContext *ctx){
+  
+}
+
+
+/*
+ * @brief: visit function type
+ * @details:
+ *      funcType: VOID | INT | FLOAT;
+ */
+std::any SysYIRGenerator::visitFuncType(SysYParser::FuncTypeContext* ctx){
+  return ctx->INT() ? Type::getIntType() : (ctx->FLOAT() ? Type::getFloatType() : Type::getVoidType());
+}
+
+/*
+ * @brief: visit function define
+ * @details:
+ *      funcDef: funcType Ident LPAREN funcFParams? RPAREN blockStmt;
+ *      funcFParams: funcFParam (COMMA funcFParam)*;
+ *      funcFParam: bType Ident (LBRACK RBRACK (LBRACK exp RBRACK)*)?;
+ * entry -> next -> others -> exit
+ * entry: allocas, br
+ * next: retval, params, br
+ * other: blockStmt init block
+ * exit: load retval, ret
+ */
+std::any SysYIRGenerator::visitFuncDef(SysYParser::FuncDefContext* ctx){
+  auto funcName = ctx->Ident()->getText();
+  auto funcParams = ctx->funcFParams()->funcFParam();
+  Type* returnType = any_cast<Type*>(ctx->funcType()->accept(this));
+
+  vector<Type*> paramTypes;
+  vector<string> paramNames;
+
+  for(auto funcParam:funcParams){
+    Type* paramType = any_cast<Type*>(funcParam->bType()->accept(this));
+    paramTypes.push_back(paramType);
+    paramNames.push_back(funcParam->Ident()->getText());
+  }
+  
+  auto funcType = FunctionType::get(returnType, paramTypes);
+  auto function = module->createFunction(funcName, funcType);
+  
+  auto entry = function->getEntryBlock();
+  for(size_t i = 0; i < paramTypes.size(); i++)
+    entry->createArgument(paramTypes[i], paramNames[i]);
+  builder.setPosition(entry, entry->end());
+  ctx->blockStmt()->accept(this);
+
+  return function;
+}
+
+/*
+ * @brief: visit blockStmt
+ * @details:
+ *      blockStmt: LBRACE blockItem* RBRACE;
+ *      blockItem: decl | stmt;
+ */
+std::any SysYIRGenerator::visitBlockStmt(SysYParser::BlockStmtContext* ctx){
+
+  SymbolTable::BlockScope scope(symbols_table);
+  
+  for (auto item : ctx->blockItem())
+    item->accept(this);
+
+  builder.getBasicBlock();
+  return std::any();
+}
+
+
+std::any SysYIRGenerator::visitFuncRParams(SysYParser::FuncRParamsContext *ctx) {
   return visitChildren(ctx);
 }
 std::any SysYIRGenerator::visitNumber(SysYParser::NumberContext *ctx) {
diff --git a/src/SysYIRGenerator.h b/src/SysYIRGenerator.h
index bfc1865..b0419a6 100644
--- a/src/SysYIRGenerator.h
+++ b/src/SysYIRGenerator.h
@@ -5,13 +5,86 @@
 #include "SysYBaseVisitor.h"
 #include "SysYParser.h"
 #include <memory>
+#include <unordered_map>
+#include <forward_list>
 
 namespace sysy {
 
+class SymbolTable{
+private:
+  enum Kind
+  {
+    kModule,
+    kFunction,
+    kBlock,
+  };
+
+  std::forward_list<std::pair<Kind, std::unordered_map<std::string, Value*>>> Scopes;
+
+public:
+  struct ModuleScope {
+    SymbolTable& tables_ref;
+    ModuleScope(SymbolTable& tables) : tables_ref(tables) {
+      tables.enter(kModule);
+    }
+    ~ModuleScope() { tables_ref.exit(); }
+  };
+  struct FunctionScope {
+    SymbolTable& tables_ref;
+    FunctionScope(SymbolTable& tables) : tables_ref(tables) {
+      tables.enter(kFunction);
+    }
+    ~FunctionScope() { tables_ref.exit(); }
+  };
+  struct BlockScope {
+    SymbolTable& tables_ref;
+    BlockScope(SymbolTable& tables) : tables_ref(tables) {
+      tables.enter(kBlock);
+    }
+    ~BlockScope() { tables_ref.exit(); }
+  };
+
+  SymbolTable() = default;
+
+  bool isModuleScope() const { return Scopes.front().first == kModule; }
+  bool isFunctionScope() const { return Scopes.front().first == kFunction; }
+  bool isBlockScope() const { return Scopes.front().first == kBlock; }
+  Value *lookup(const std::string &name) const {
+    for (auto &scope : Scopes) {
+      auto iter = scope.second.find(name);
+      if (iter != scope.second.end())
+        return iter->second;
+    }
+    return nullptr;
+  }
+  auto insert(const std::string &name, Value *value) {
+    assert(not Scopes.empty());
+    return Scopes.front().second.emplace(name, value);
+  }
+private:
+  void enter(Kind kind) {
+    Scopes.emplace_front();
+    Scopes.front().first = kind;
+  }
+  void exit() {
+    Scopes.pop_front(); 
+  }
+  
+};
+
 class SysYIRGenerator : public SysYBaseVisitor {
 private:
   std::unique_ptr<Module> module;
   IRBuilder builder;
+  SymbolTable symbols_table;
+  //array init use variables
+  int d = 0, n = 0;
+  vector<int> path;
+  bool isalloca;
+  AllocaInst *current_alloca;
+  GlobalValue *current_global;
+  Type *current_type;
+  int numdims = 0;
 
 public:
   SysYIRGenerator() = default;
@@ -21,9 +94,50 @@ public:
 
 public:
   std::any visitCompUnit(SysYParser::CompUnitContext *ctx) override;
+
+  std::any visitDecl(SysYParser::DeclContext *ctx) override;
+
+  std::any visitConstDecl(SysYParser::ConstDeclContext *ctx) override;
+
+  std::any visitBType(SysYParser::BTypeContext *ctx) override;
+  
+  std::any visitConstDef(SysYParser::ConstDefContext *ctx) override;
+
+  std::any visitConstInitVal(SysYParser::ConstInitValContext *ctx) override;
+
+  std::any visitFuncType(SysYParser::FuncTypeContext* ctx) override;
+
+  std::any visitFuncDef(SysYParser::FuncDefContext* ctx) override;
+
+
+  std::any visitVarDecl(SysYParser::VarDeclContext *ctx) override;
+
+  std::any visitVarDef(SysYParser::VarDefContext *ctx, Type* btype);
+
+  std::any visitFuncFParam(SysYParser::FuncFParamContext *ctx) override;
+
+  std::any visitFuncFParams(SysYParser::FuncFParamsContext *ctx) override;
+
+  std::any visitBlockStmt(SysYParser::BlockStmtContext* ctx) override;
+
+  std::any visitStmt(SysYParser::StmtContext *ctx) override;
+  
   std::any visitFuncRParams(SysYParser::FuncRParamsContext *ctx) override;
+
   std::any visitNumber(SysYParser::NumberContext *ctx) override;
+
   std::any visitString(SysYParser::StringContext *ctx) override;
+
+private:
+  std::any visitConstGlobalDecl(SysYParser::ConstDeclContext *ctx, Type* type);
+  std::any visitVarGlobalDecl(SysYParser::VarDeclContext *ctx, Type* type);
+  std::any visitConstLocalDecl(SysYParser::ConstDeclContext *ctx, Type* type);
+  std::any visitVarLocalDecl(SysYParser::VarDeclContext *ctx, Type* type);
+  Type *getArithmeticResultType(Type *lhs, Type *rhs) {
+    assert(lhs->isIntOrFloat() and rhs->isIntOrFloat());
+    return lhs == rhs ? lhs : Type::getFloatType();
+  }
+
 }; // class SysYIRGenerator
 
 } // namespace sysy
\ No newline at end of file