LLVMCodeBuilder: Sync variables before calling functions

Author: adazem009

src/engine/internal/llvm/llvmcodebuilder.cpp

@@ -161,6 +161,9 @@ std::shared_ptr<ExecutableCode> LLVMCodeBuilder::finalize()
                 std::vector<llvm::Type *> types;
                 std::vector<llvm::Value *> args;
 
+                // Variables must be synchronized because the function can read them
+                syncVariables(targetVariables);
+
                 // Add execution context arg
                 if (step.functionCtxArg) {
                     types.push_back(llvm::PointerType::get(llvm::Type::getInt8Ty(m_llvmCtx), 0));

test/llvm/llvmcodebuilder_test.cpp

@@ -2106,6 +2106,39 @@ TEST_F(LLVMCodeBuilderTest, ReadVariable)
     ASSERT_EQ(testing::internal::GetCapturedStdout(), expected);
 }
 
+TEST_F(LLVMCodeBuilderTest, SyncVariablesBeforeCallingFunction)
+{
+    Sprite sprite;
+    sprite.setEngine(&m_engine);
+
+    auto var = std::make_shared<Variable>("", "");
+    sprite.addVariable(var);
+
+    createBuilder(&sprite, true);
+
+    CompilerValue *v = m_builder->addConstValue("abc");
+    m_builder->createVariableWrite(var.get(), v);
+
+    v = m_builder->addConstValue(123);
+    m_builder->createVariableWrite(var.get(), v);
+
+    m_builder->addTargetFunctionCall("test_print_first_local_variable", Compiler::StaticType::Void, {}, {});
+
+    v = m_builder->addConstValue(456);
+    m_builder->createVariableWrite(var.get(), v);
+
+    auto code = m_builder->finalize();
+    Script script(&sprite, nullptr, nullptr);
+    script.setCode(code);
+
+    Thread thread(&sprite, nullptr, &script);
+    auto ctx = code->createExecutionContext(&thread);
+    testing::internal::CaptureStdout();
+    code->run(ctx.get());
+
+    ASSERT_EQ(testing::internal::GetCapturedStdout(), "123\n");
+}
+
 TEST_F(LLVMCodeBuilderTest, CastNonRawValueToUnknownType)
 {
     Stage stage;

test/llvm/testfunctions.cpp

@@ -2,6 +2,7 @@
 #include <scratchcpp/string_functions.h>
 #include <scratchcpp/stringptr.h>
 #include <scratchcpp/string_pool.h>
+#include <scratchcpp/variable.h>
 #include <utf8.h>
 #include <iostream>
 #include <targetmock.h>
@@ -189,4 +190,9 @@ extern "C"
         value_toString(v, &str);
         std::cout << str << std::endl;
     }
+
+    void test_print_first_local_variable(Target *target)
+    {
+        std::cout << target->variableAt(0)->value().toString() << std::endl;
+    }
 }

test/llvm/testfunctions.h

@@ -48,6 +48,8 @@ extern "C"
     void test_print_string(const StringPtr *v);
     void test_print_pointer(const void *v);
     void test_print_unknown(const ValueData *v);
+
+    void test_print_first_local_variable(Target *target);
 }
 
 } // namespace libscratchcpp