runtime: Add atexit callbacks

Author: gf712

src/executable/bytecode/BytecodeProgram.cpp

@@ -144,6 +144,11 @@ int BytecodeProgram::execute(VirtualMachine *vm)
 		std::cout << exception->format_traceback() << std::endl;
 	}
 
+	{
+		[[maybe_unused]] auto push_result = vm->push_frame(1, 0, 0);
+		[[maybe_unused]] auto final_result = interpreter.finalise();
+	}
+
 	return result.is_ok() ? EXIT_SUCCESS : EXIT_FAILURE;
 }
 

src/interpreter/Interpreter.cpp

@@ -27,6 +27,7 @@
 
 #include <cstdio>
 #include <filesystem>
+#include <ranges>
 #include <unistd.h>
 
 namespace fs = std::filesystem;
@@ -495,4 +496,32 @@ void Interpreter::visit_graph(::Cell::Visitor &visitor)
 	if (m_codec_error_registry) visitor.visit(*m_codec_error_registry);
 	if (m_codec_search_path) visitor.visit(*m_codec_search_path);
 	if (m_codec_search_path_cache) visitor.visit(*m_codec_search_path_cache);
+
+	for (auto [callback, args] : m_callbacks) {
+		if (callback) visitor.visit(*callback);
+		if (args) visitor.visit(*args);
+	}
+}
+
+void Interpreter::register_callback(PyObject *callback, PyTuple *args)
+{
+	m_callbacks.emplace_back(callback, args);
+}
+
+void Interpreter::unregister_callback(PyObject *callback)
+{
+	m_callbacks.erase(
+		std::ranges::remove(m_callbacks, callback, [](const auto &el) { return std::get<0>(el); })
+			.begin(),
+		m_callbacks.end());
+}
+
+PyResult<std::monostate> Interpreter::finalise()
+{
+	// TODO: capture exceptions, and raise last one
+	for (auto [callback, args] : m_callbacks) {
+		[[maybe_unused]] auto result = callback->call(args, nullptr);
+	}
+
+	return Ok(std::monostate{});
 }

src/interpreter/Interpreter.hpp

@@ -6,6 +6,7 @@
 
 #include <string>
 #include <string_view>
+#include <variant>
 
 class BytecodeProgram;
 
@@ -34,6 +35,7 @@ class Interpreter
 	py::PyDict *m_codec_search_path_cache{ nullptr };
 	std::string m_entry_script;
 	std::vector<std::string> m_argv;
+	std::vector<std::tuple<py::PyObject *, py::PyTuple *>> m_callbacks;
 
   public:
 	struct Config
@@ -89,6 +91,8 @@ class Interpreter
 	void setup(std::shared_ptr<BytecodeProgram> &&program);
 	void setup_main_interpreter(std::shared_ptr<BytecodeProgram> &&program);
 
+	py::PyResult<std::monostate> finalise();
+
 	const std::string &entry_script() const { return m_entry_script; }
 	const std::vector<std::string> &argv() const { return m_argv; }
 
@@ -107,6 +111,10 @@ class Interpreter
 		py::PyTuple *args,
 		py::PyDict *kwargs);
 
+
+	void register_callback(py::PyObject *callback, py::PyTuple *args);
+	void unregister_callback(py::PyObject *callback);
+
 	void visit_graph(::Cell::Visitor &);
 
   private:

src/repl/repl.cpp

@@ -230,4 +230,4 @@ int main(int argc, char **argv)
 	// }
 
 	return EXIT_SUCCESS;
-}
+}