Add compiling of lvalues differently

src/codegen.cpp

@@ -6,6 +6,12 @@
 #include <memory>
 #include <iostream>
 
+namespace codegen {
+    Scope Scope::with_lvalue() {
+        return Scope{ this->values, true };
+    }
+}
+
 namespace AST {
     llvm::Value* IntLiteralExpression::codegen(codegen::Builder& builder, codegen::Scope& scope) {
         auto ty = builder.builder->getInt32Ty();
@@ -15,7 +21,12 @@ namespace AST {
     llvm::Value* ValueReferenceExpression::codegen(codegen::Builder& builder, codegen::Scope& scope) {
         auto value = scope.values.find(this->m_name);
         if (value != scope.values.end()) {
-            return builder.builder->CreateLoad(value->second.ty, value->second.value);
+            if (scope.is_lvalue) {
+                return value->second.value;
+            }
+            else {
+                return builder.builder->CreateLoad(value->second.ty, value->second.value);
+            }
         }
         else {
             throw new std::runtime_error("Value " + this->m_name + " not found");
@@ -23,12 +34,18 @@ namespace AST {
     }
 
     llvm::Value* BinaryOperationExpression::codegen(codegen::Builder& builder, codegen::Scope& scope) {
-        auto lhs = this->m_lhs->codegen(builder, scope);
+        auto lvalued = scope.with_lvalue();
+        auto lhs = this->m_lhs->codegen(builder, lvalued);
         auto rhs = this->m_rhs->codegen(builder, scope);
         switch (this->m_binop) {
         case BinOp::Assignment:
             builder.builder->CreateStore(rhs, lhs, false);
-            return lhs;
+            if (scope.is_lvalue) {
+                return lhs;
+            }
+            else {
+                return rhs;
+            }
         default:
             throw std::runtime_error("invalid binop");
         }

src/codegen.h

@@ -21,6 +21,9 @@ namespace codegen {
 
     struct Scope {
         std::map<std::string, StackValue> values;
+        bool is_lvalue;
+
+        Scope with_lvalue();
     };
 }