fix(ir): 规范ir实现

doc/Lab1-语法树构建.md

@@ -69,3 +69,8 @@ java -jar third_party/antlr-4.13.2-complete.jar \
 # 仅输出语法树
 ./build/bin/compiler --emit-parse-tree test/test_case/simple_add.sy
 ```
+
+## 7. 关于 AST 的建议
+
+同学们也可以自行设计一层抽象语法树（AST），将 ANTLR 语法树先转换为 AST，再进入后续阶段。  
+这样可以减少对具体文法细节的依赖，使语义分析、IR 生成和后续扩展更清晰。这里不做具体要求。

doc/Lab2-中间表示生成.md

@@ -57,6 +57,9 @@ Lab2 的目标是在该示例基础上扩展语义覆盖范围，逐步把更多
 
 说明：当前阶段变量统一采用内存模型：先 `alloca` 分配栈槽，再通过 `store/load` 读写。即使变量由常量初始化（如 `int a = 1;`），也会先 `store` 到栈槽，而不是直接把变量替换成 SSA 值。后续实验中，同学可按需求再重构。
 
+此外，当前 IR 还维护了最基本的 use-def 关系：每个 `Value` 会记录哪些 `Instruction` 使用了它。  
+这对后续做数据流分析、死代码删除、常量传播等优化会很有帮助；但目前相关实现，接口仍不完整，后续实验中还需要同学继续补充和完善。
+
 ## 6. 构建与运行
 
 ```bash

src/ir/Function.cpp

@@ -6,7 +6,18 @@
 namespace ir {
 
 Function::Function(std::string name, std::shared_ptr<Type> ret_type)
-    : Value(std::move(ret_type), std::move(name)),
+    : Value(std::move(ret_type), std::move(name)) {
-      entry_(std::make_unique<BasicBlock>("entry")) {}
+  entry_ = CreateBlock("entry");
+}
+
+BasicBlock* Function::CreateBlock(const std::string& name) {
+  auto block = std::make_unique<BasicBlock>(name);
+  auto* ptr = block.get();
+  blocks_.push_back(std::move(block));
+  if (!entry_) {
+    entry_ = ptr;
+  }
+  return ptr;
+}
 
 }  // namespace ir

src/ir/IR.h

@@ -3,6 +3,7 @@
 #pragma once
 
 #include <memory>
+#include <stdexcept>
 #include <string>
 #include <unordered_map>
 #include <utility>
@@ -13,6 +14,7 @@ namespace ir {
 class Type;
 class ConstantInt;
 class Instruction;
+class BasicBlock;
 
 // IR 上下文：集中管理类型、常量等共享资源，便于复用与扩展。
 class Context {
@@ -82,9 +84,13 @@ class Instruction : public Value {
   Instruction(Opcode op, std::shared_ptr<Type> ty, std::string name = "")
       : Value(std::move(ty), std::move(name)), opcode_(op) {}
   Opcode opcode() const { return opcode_; }
+  bool IsTerminator() const { return opcode_ == Opcode::Ret; }
+  BasicBlock* parent() const { return parent_; }
+  void set_parent(BasicBlock* parent) { parent_ = parent; }
 
  private:
   Opcode opcode_;
+  BasicBlock* parent_ = nullptr;
 };
 
 class BinaryInst : public Instruction {
@@ -137,13 +143,21 @@ class BasicBlock {
  public:
   explicit BasicBlock(std::string name) : name_(std::move(name)) {}
   const std::string& name() const { return name_; }
+  bool HasTerminator() const {
+    return !instructions_.empty() && instructions_.back()->IsTerminator();
+  }
   const std::vector<std::unique_ptr<Instruction>>& instructions() const {
     return instructions_;
   }
   template <typename T, typename... Args>
   T* Append(Args&&... args) {
+    if (HasTerminator()) {
+      throw std::runtime_error("BasicBlock 已有 terminator，不能继续追加指令: " +
+                               name_);
+    }
     auto inst = std::make_unique<T>(std::forward<Args>(args)...);
     auto* ptr = inst.get();
+    ptr->set_parent(this);
     instructions_.push_back(std::move(inst));
     return ptr;
   }
@@ -157,11 +171,16 @@ class Function : public Value {
  public:
   // 允许显式指定返回类型，便于后续扩展多种函数签名。
   Function(std::string name, std::shared_ptr<Type> ret_type);
-  BasicBlock* entry() { return entry_.get(); }
+  BasicBlock* CreateBlock(const std::string& name);
-  const BasicBlock* entry() const { return entry_.get(); }
+  BasicBlock* entry() { return entry_; }
+  const BasicBlock* entry() const { return entry_; }
+  const std::vector<std::unique_ptr<BasicBlock>>& blocks() const {
+    return blocks_;
+  }
 
  private:
-  std::unique_ptr<BasicBlock> entry_;
+  BasicBlock* entry_ = nullptr;
+  std::vector<std::unique_ptr<BasicBlock>> blocks_;
 };
 
 class Module {

src/ir/IRBuilder.cpp

@@ -12,6 +12,10 @@ bool IsArithmeticType(const std::shared_ptr<Type>& ty) {
   return ty && ty->kind() == Type::Kind::Int32;
 }
 
+bool IsPtrInt32Type(const std::shared_ptr<Type>& ty) {
+  return ty && ty->kind() == Type::Kind::PtrInt32;
+}
+
 }  // namespace
 
 ConstantInt* IRBuilder::CreateConstInt(int v) {
@@ -54,6 +58,12 @@ LoadInst* IRBuilder::CreateLoad(Value* ptr, const std::string& name) {
   if (!insertBlock_) {
     throw std::runtime_error("IRBuilder 未设置插入点");
   }
+  if (!ptr) {
+    throw std::runtime_error("IRBuilder::CreateLoad 缺少 ptr");
+  }
+  if (!IsPtrInt32Type(ptr->type())) {
+    throw std::runtime_error("IRBuilder::CreateLoad 当前只支持从 i32* 加载");
+  }
   return insertBlock_->Append<LoadInst>(ptr, name);
 }
 
@@ -61,6 +71,18 @@ StoreInst* IRBuilder::CreateStore(Value* val, Value* ptr) {
   if (!insertBlock_) {
     throw std::runtime_error("IRBuilder 未设置插入点");
   }
+  if (!val) {
+    throw std::runtime_error("IRBuilder::CreateStore 缺少 val");
+  }
+  if (!ptr) {
+    throw std::runtime_error("IRBuilder::CreateStore 缺少 ptr");
+  }
+  if (!IsArithmeticType(val->type())) {
+    throw std::runtime_error("IRBuilder::CreateStore 当前只支持存储 i32");
+  }
+  if (!IsPtrInt32Type(ptr->type())) {
+    throw std::runtime_error("IRBuilder::CreateStore 当前只支持写入 i32*");
+  }
   return insertBlock_->Append<StoreInst>(val, ptr);
 }
 
@@ -68,6 +90,9 @@ ReturnInst* IRBuilder::CreateRet(Value* v) {
   if (!insertBlock_) {
     throw std::runtime_error("IRBuilder 未设置插入点");
   }
+  if (!v) {
+    throw std::runtime_error("IRBuilder::CreateRet 缺少返回值");
+  }
   return insertBlock_->Append<ReturnInst>(v);
 }
 

src/ir/IRPrinter.cpp

@@ -5,6 +5,7 @@
 #include "ir/IR.h"
 
 #include <iostream>
+#include <string>
 #include <stdexcept>
 
 namespace ir {
@@ -41,6 +42,13 @@ static const char* OpcodeToString(Opcode op) {
   return "?";
 }
 
+static std::string ValueToString(const Value* v) {
+  if (auto* ci = dynamic_cast<const ConstantInt*>(v)) {
+    return std::to_string(ci->value());
+  }
+  return v ? v->name() : "<null>";
+}
+
 void IRPrinter::Print(const Module& module) {
   for (const auto& func : module.functions()) {
     std::cout << "define " << TypeToString(*func->type()) << " @"
@@ -60,7 +68,8 @@ void IRPrinter::Print(const Module& module) {
           auto* bin = static_cast<const BinaryInst*>(inst);
           std::cout << "  " << bin->name() << " = " << OpcodeToString(bin->opcode())
                     << " " << TypeToString(*bin->lhs()->type()) << " "
-                    << bin->lhs()->name() << ", " << bin->rhs()->name() << "\n";
+                    << ValueToString(bin->lhs()) << ", "
+                    << ValueToString(bin->rhs()) << "\n";
           break;
         }
         case Opcode::Alloca: {
@@ -71,19 +80,19 @@ void IRPrinter::Print(const Module& module) {
         case Opcode::Load: {
           auto* load = static_cast<const LoadInst*>(inst);
           std::cout << "  " << load->name() << " = load i32, i32* "
-                    << load->ptr()->name() << "\n";
+                    << ValueToString(load->ptr()) << "\n";
           break;
         }
         case Opcode::Store: {
           auto* store = static_cast<const StoreInst*>(inst);
-          std::cout << "  store i32 " << store->value()->name() << ", i32* "
+          std::cout << "  store i32 " << ValueToString(store->value()) << ", i32* "
-                    << store->ptr()->name() << "\n";
+                    << ValueToString(store->ptr()) << "\n";
           break;
         }
         case Opcode::Ret: {
           auto* ret = static_cast<const ReturnInst*>(inst);
           std::cout << "  ret " << TypeToString(*ret->value()->type()) << " "
-                    << ret->value()->name() << "\n";
+                    << ValueToString(ret->value()) << "\n";
           break;
         }
       }

src/ir/Instruction.cpp

@@ -3,11 +3,40 @@
 // - 指令操作数与结果类型管理，支持打印与优化
 #include "ir/IR.h"
 
+#include <stdexcept>
+
 namespace ir {
+namespace {
+
+bool IsArithmeticType(const std::shared_ptr<Type>& ty) {
+  return ty && ty->kind() == Type::Kind::Int32;
+}
+
+bool IsPtrInt32Type(const std::shared_ptr<Type>& ty) {
+  return ty && ty->kind() == Type::Kind::PtrInt32;
+}
+
+}  // namespace
 
 BinaryInst::BinaryInst(Opcode op, std::shared_ptr<Type> ty, Value* lhs,
                        Value* rhs, std::string name)
     : Instruction(op, std::move(ty), std::move(name)), lhs_(lhs), rhs_(rhs) {
+  if (op != Opcode::Add) {
+    throw std::runtime_error("BinaryInst 当前只支持 Add");
+  }
+  if (!lhs_ || !rhs_) {
+    throw std::runtime_error("BinaryInst 缺少操作数");
+  }
+  if (!type_ || !lhs_->type() || !rhs_->type()) {
+    throw std::runtime_error("BinaryInst 缺少类型信息");
+  }
+  if (lhs_->type()->kind() != rhs_->type()->kind() ||
+      type_->kind() != lhs_->type()->kind()) {
+    throw std::runtime_error("BinaryInst 类型不匹配");
+  }
+  if (!IsArithmeticType(type_)) {
+    throw std::runtime_error("BinaryInst 当前只支持 i32");
+  }
   if (lhs_) {
     lhs_->AddUser(this);
   }
@@ -18,9 +47,10 @@ BinaryInst::BinaryInst(Opcode op, std::shared_ptr<Type> ty, Value* lhs,
 
 ReturnInst::ReturnInst(Value* val)
     : Instruction(Opcode::Ret, Type::Void(), ""), value_(val) {
-  if (value_) {
+  if (!value_) {
-    value_->AddUser(this);
+    throw std::runtime_error("ReturnInst 缺少返回值");
   }
+  value_->AddUser(this);
 }
 
 AllocaInst::AllocaInst(std::string name)
@@ -28,19 +58,31 @@ AllocaInst::AllocaInst(std::string name)
 
 LoadInst::LoadInst(Value* ptr, std::string name)
     : Instruction(Opcode::Load, Type::Int32(), std::move(name)), ptr_(ptr) {
-  if (ptr_) {
+  if (!ptr_) {
-    ptr_->AddUser(this);
+    throw std::runtime_error("LoadInst 缺少 ptr");
   }
+  if (!IsPtrInt32Type(ptr_->type())) {
+    throw std::runtime_error("LoadInst 当前只支持从 i32* 加载");
+  }
+  ptr_->AddUser(this);
 }
 
 StoreInst::StoreInst(Value* val, Value* ptr)
     : Instruction(Opcode::Store, Type::Void(), ""), value_(val), ptr_(ptr) {
-  if (value_) {
+  if (!value_) {
+    throw std::runtime_error("StoreInst 缺少 value");
+  }
+  if (!ptr_) {
+    throw std::runtime_error("StoreInst 缺少 ptr");
+  }
+  if (!IsArithmeticType(value_->type())) {
+    throw std::runtime_error("StoreInst 当前只支持存储 i32");
+  }
+  if (!IsPtrInt32Type(ptr_->type())) {
+    throw std::runtime_error("StoreInst 当前只支持写入 i32*");
+  }
   value_->AddUser(this);
-  }
-  if (ptr_) {
   ptr_->AddUser(this);
-  }
 }
 
 }  // namespace ir

src/irgen/IRGenStmt.cpp

@@ -6,10 +6,6 @@
 #include "ir/IR.h"
 
 bool IRGenImpl::GenStmt(SysYParser::StmtContext& stmt) {
-  if (stmt.varDecl()) {
-    GenVarDecl(*stmt.varDecl());
-    return false;
-  }
   if (stmt.returnStmt()) {
     GenReturnStmt(*stmt.returnStmt());
     return true;