From 8297700496bcd894f8454637e909ba98cb867e63 Mon Sep 17 00:00:00 2001
From: lc <18783417278@163.com>
Date: Mon, 30 Mar 2026 20:36:21 +0800
Subject: [PATCH] =?UTF-8?q?IRGen=E9=83=A8=E5=88=86=E5=AE=9E=E7=8E=B0?=
 =?UTF-8?q?=EF=BC=9A=E6=94=AF=E6=8C=81=E8=B5=8B=E5=80=BC=E8=A1=A8=E8=BE=BE?=
 =?UTF-8?q?=E5=BC=8F?=
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---
 src/irgen/IRGenStmt.cpp | 39 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/src/irgen/IRGenStmt.cpp b/src/irgen/IRGenStmt.cpp
index 8f7a2a5..de6a857 100644
--- a/src/irgen/IRGenStmt.cpp
+++ b/src/irgen/IRGenStmt.cpp
@@ -9,9 +9,9 @@
 // 语句生成当前只实现了最小子集。
 // 目前支持：
 // - return <exp>;
+// - 赋值语句：lVal = exp;
 //
 // 还未支持：
-// - 赋值语句
 // - if / while 等控制流
 // - 空语句、块语句嵌套分发之外的更多语句形态
 
@@ -19,6 +19,42 @@ std::any IRGenImpl::visitStmt(SysYParser::StmtContext* ctx) {
   if (!ctx) {
     throw std::runtime_error(FormatError("irgen", "缺少语句"));
   }
+  
+  // 检查是否是赋值语句：lVal ASSIGN exp SEMICOLON
+  if (ctx->lVal() && ctx->ASSIGN()) {
+    if (!ctx->exp()) {
+      throw std::runtime_error(FormatError("irgen", "赋值语句缺少表达式"));
+    }
+    
+    // 1. 计算右值表达式的值
+    ir::Value* rhs = EvalExpr(*ctx->exp());
+    
+    // 2. 找到左值变量对应的存储槽位
+    auto* lval_ctx = ctx->lVal();
+    if (!lval_ctx || !lval_ctx->ID()) {
+      throw std::runtime_error(FormatError("irgen", "当前仅支持普通整型变量赋值"));
+    }
+    
+    const auto* decl = sema_.ResolveObjectUse(lval_ctx);
+    if (!decl) {
+      throw std::runtime_error(
+          FormatError("irgen",
+                      "变量使用缺少语义绑定：" + lval_ctx->ID()->getText()));
+    }
+    
+    std::string var_name = lval_ctx->ID()->getText();
+    auto it = storage_map_.find(var_name);
+    if (it == storage_map_.end()) {
+      throw std::runtime_error(
+          FormatError("irgen",
+                      "变量声明缺少存储槽位：" + var_name));
+    }
+    
+    // 3. 生成 store 指令
+    builder_.CreateStore(rhs, it->second);
+    return BlockFlow::Continue;
+  }
+  
   // 检查是否是 return 语句：RETURN exp? SEMICOLON
   if (ctx->RETURN()) {
     if (!ctx->exp()) {
@@ -28,5 +64,6 @@ std::any IRGenImpl::visitStmt(SysYParser::StmtContext* ctx) {
     builder_.CreateRet(v);
     return BlockFlow::Terminated;
   }
+  
   throw std::runtime_error(FormatError("irgen", "暂不支持的语句类型"));
 }