[midend-mem2reg]修复assignstmt对lvalue的错误解析（lvaue会被exp解释为值，而被assign解释为地址）

src/SysYIRGenerator.cpp

@@ -450,44 +450,79 @@ std::any SysYIRGenerator::visitBlockStmt(SysYParser::BlockStmtContext *ctx) {
 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)));
+  Value* LValue = nullptr;
+  Value* variable = module->getVariable(name); // 左值
+
+  vector<Value *> indices;
+  if (lVal->exp().size() > 0) {
+    // 如果有下标，访问表达式获取下标值
+    for (const auto &exp : lVal->exp()) {
+      Value* indexValue = std::any_cast<Value *>(visitExp(exp));
+      indices.push_back(indexValue);
+    }
+  }
+  if (indices.empty()) {
+    // 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)) {
+        LValue = variable;
+    }
+  }
+  else {
+    // 对于数组或多维数组的左值处理
+    // 需要获取 GEP 地址
+    Value* gepBasePointer = nullptr;
+    std::vector<Value*> gepIndices; 
+    if (AllocaInst *alloc = dynamic_cast<AllocaInst *>(variable)) {
+      Type* allocatedType = alloc->getType()->as<PointerType>()->getBaseType(); 
+      if (allocatedType->isPointer()) {
+        gepBasePointer = builder.createLoadInst(alloc); 
+        gepIndices = indices; 
+      } else {
+        gepBasePointer = alloc;
+        gepIndices.push_back(ConstantInteger::get(0));
+        gepIndices.insert(gepIndices.end(), indices.begin(), indices.end());
+      }
+    } else if (GlobalValue *glob = dynamic_cast<GlobalValue *>(variable)) {
+      // 情况 B: 全局变量 (GlobalValue)
+      gepBasePointer = glob; 
+      gepIndices.push_back(ConstantInteger::get(0));
+      gepIndices.insert(gepIndices.end(), indices.begin(), indices.end());
+    } else if (ConstantVariable *constV = dynamic_cast<ConstantVariable *>(variable)) {
+      gepBasePointer = constV;
+      gepIndices.push_back(ConstantInteger::get(0));
+      gepIndices.insert(gepIndices.end(), indices.begin(), indices.end());
+    } 
+    // 左值为地址
+    LValue = getGEPAddressInst(gepBasePointer, gepIndices);
   }
-  
-  auto variable = module->getVariable(name); // 获取 AllocaInst 或 GlobalValue
-  Value* value = std::any_cast<Value *>(visitExp(ctx->exp())); // 右值
 
-  Type* targetElementType = variable->getType(); // 从基指针指向的类型开始
+  Value* RValue = std::any_cast<Value *>(visitExp(ctx->exp())); // 右值
 
-  //根据 dims 确定最终元素的类型
-  targetElementType = builder.getIndexedType(targetElementType, dims);
+  // 先推断 LValue 的类型
+  // 如果 LValue 是指向数组的指针，则需要根据 indices 获取正确的类型
+  // 如果 LValue 是标量，则直接使用其类型
+  // 注意：LValue 的类型可能是指向数组的指针 (e.g., int(*)[3]) 或者指向标量的指针 (e.g., int*) 也能推断
+  Type* LType = builder.getIndexedType(variable->getType(), indices);
+  Type* RType = RValue->getType();
 
-  // 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 (LType != RType) {
+    ConstantValue * constValue = dynamic_cast<ConstantValue *>(RValue);
     if (constValue != nullptr) {
-      if (targetElementType == Type::getFloatType()) {
-        value = ConstantFloating::get(static_cast<float>(constValue->getFloat()));
+      if (LType == Type::getFloatType()) {
+        RValue = ConstantFloating::get(static_cast<float>(constValue->getFloat()));
       } else { // 假设如果不是浮点型，就是整型
-        value = ConstantInteger::get(static_cast<int>(constValue->getInt()));
+        RValue = ConstantInteger::get(static_cast<int>(constValue->getInt()));
       }
     } else {
-      if (targetElementType == Type::getFloatType()) {
-        value = builder.createIToFInst(value);
+      if (LType == Type::getFloatType()) {
+        RValue = builder.createIToFInst(RValue);
       } else { // 假设如果不是浮点型，就是整型
-        value = builder.createFtoIInst(value);
+        RValue = builder.createFtoIInst(RValue);
       }
     }
   }
 
-  // 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);
+  builder.createStoreInst(RValue, LValue);
 
   return std::any();
 }
@@ -711,7 +746,7 @@ unsigned SysYIRGenerator::countArrayDimensions(Type* type) {
 
 std::any SysYIRGenerator::visitLValue(SysYParser::LValueContext *ctx) {
   std::string name = ctx->Ident()->getText();
-  User* variable = module->getVariable(name);
+  Value* variable = module->getVariable(name);
 
   Value* value = nullptr;