Scripting: Start bringing up Lua bindings

CMakeLists.txt

@@ -57,6 +57,7 @@ if(NOT LIBMGBA_ONLY)
 	set(USE_LIBZIP ON CACHE BOOL "Whether or not to enable LIBZIP support")
 	set(USE_SQLITE3 ON CACHE BOOL "Whether or not to enable SQLite3 support")
 	set(USE_ELF ON CACHE BOOL "Whether or not to enable ELF support")
+	set(USE_LUA ON CACHE BOOL "Whether or not to enable Lua scripting support")
 	set(M_CORE_GBA ON CACHE BOOL "Build Game Boy Advance core")
 	set(M_CORE_GB ON CACHE BOOL "Build Game Boy core")
 	set(USE_LZMA ON CACHE BOOL "Whether or not to enable 7-Zip support")
@@ -735,6 +736,17 @@ endif()
 if(ENABLE_SCRIPTING)
 	add_subdirectory(src/script)
 	list(APPEND ENABLES SCRIPTING)
+	if(NOT USE_LUA VERSION_LESS 5.1)
+		find_feature(USE_LUA "Lua" ${USE_LUA})
+	else()
+		find_feature(USE_LUA "Lua")
+	endif()
+	if(USE_LUA)
+		list(APPEND FEATURE_DEFINES USE_LUA)
+		include_directories(AFTER ${LUA_INCLUDE_DIR})
+		list(APPEND FEATURE_DEFINES LUA_VERSION_ONLY=\"${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}\")
+		list(APPEND DEPENDENCY_LIB ${LUA_LIBRARY})
+	endif()
 
 	if(BUILD_PYTHON)
 		find_package(PythonLibs ${USE_PYTHON_VERSION})
@@ -1226,6 +1238,14 @@ if(NOT QUIET AND NOT LIBMGBA_ONLY)
 	message(STATUS "	ELF loading support: ${USE_ELF}")
 	message(STATUS "	Discord Rich Presence support: ${USE_DISCORD_RPC}")
 	message(STATUS "	OpenGL support: ${SUMMARY_GL}")
+	message(STATUS "Scripting support: ${ENABLE_SCRIPTING}")
+	if(ENABLE_SCRIPTING)
+		if(LUA_VERSION_STRING)
+			message(STATUS "	Lua: ${LUA_VERSION_STRING}")
+		else()
+			message(STATUS "	Lua: ${USE_LUA}")
+		endif()
+	endif()
 	message(STATUS "Frontends:")
 	message(STATUS "	Qt: ${BUILD_QT}")
 	message(STATUS "	SDL (${SDL_VERSION}): ${BUILD_SDL}")

include/mgba/internal/script/lua.h

@@ -0,0 +1,12 @@
+/* Copyright (c) 2013-2022 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef M_SCRIPT_LUA_H
+#define M_SCRIPT_LUA_H
+#include <mgba/script/context.h>
+
+extern struct mScriptEngine2* const mSCRIPT_ENGINE_LUA;
+
+#endif

src/script/CMakeLists.txt

@@ -6,6 +6,11 @@ set(SOURCE_FILES
 set(TEST_FILES
 	test/types.c)
 
+if(USE_LUA)
+	list(APPEND SOURCE_FILES engines/lua.c)
+	list(APPEND TEST_FILES test/lua.c)
+endif()
+
 source_group("Scripting" FILES ${SOURCE_FILES})
 source_group("Scripting tests" FILES ${TEST_FILES})
 

src/script/engines/lua.c

@@ -0,0 +1,91 @@
+/* Copyright (c) 2013-2022 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include <mgba/internal/script/lua.h>
+#include <lauxlib.h>
+
+static struct mScriptEngineContext* _luaCreate(struct mScriptEngine2*, struct mScriptContext*);
+
+static void _luaDestroy(struct mScriptEngineContext*);
+static bool _luaLoad(struct mScriptEngineContext*, struct VFile*, const char** error);
+
+struct mScriptEngineContextLua {
+	struct mScriptEngineContext d;
+	lua_State* lua;
+};
+
+static struct mScriptEngineLua {
+	struct mScriptEngine2 d;
+} _engineLua = {
+	.d = {
+		.name = "lua-" LUA_VERSION_ONLY,
+		.init = NULL,
+		.deinit = NULL,
+		.create = _luaCreate
+	}
+};
+
+struct mScriptEngine2* const mSCRIPT_ENGINE_LUA = &_engineLua.d;
+
+struct mScriptEngineContext* _luaCreate(struct mScriptEngine2* engine, struct mScriptContext* context) {
+	UNUSED(engine);
+	struct mScriptEngineContextLua* luaContext = calloc(1, sizeof(*luaContext));
+	luaContext->d = (struct mScriptEngineContext) {
+		.context = context,
+		.destroy = _luaDestroy,
+		.load = _luaLoad,
+	};
+	luaContext->lua = luaL_newstate();
+	return &luaContext->d;
+}
+
+void _luaDestroy(struct mScriptEngineContext* ctx) {
+	struct mScriptEngineContextLua* luaContext = (struct mScriptEngineContextLua*) ctx;
+	lua_close(luaContext->lua);
+	free(luaContext);
+}
+
+#define LUA_BLOCKSIZE 0x1000
+struct mScriptEngineLuaReader {
+	struct VFile* vf;
+	char block[LUA_BLOCKSIZE];
+};
+
+static const char* _reader(lua_State* lua, void* context, size_t* size) {
+	UNUSED(lua);
+	struct mScriptEngineLuaReader* reader = context;
+	ssize_t s = reader->vf->read(reader->vf, reader->block, sizeof(reader->block));
+	if (s < 0) {
+		return NULL;
+	}
+	*size = s;
+	return reader->block;
+}
+
+bool _luaLoad(struct mScriptEngineContext* ctx, struct VFile* vf, const char** error) {
+	struct mScriptEngineContextLua* luaContext = (struct mScriptEngineContextLua*) ctx;
+	struct mScriptEngineLuaReader data = {
+		.vf = vf
+	};
+	int ret = lua_load(luaContext->lua, _reader, &data, NULL, "t");
+	switch (ret) {
+	case LUA_OK:
+		if (error) {
+			*error = NULL;
+		}
+		return true;
+	case LUA_ERRSYNTAX:
+		if (error) {
+			*error = "Syntax error";
+		}
+		break;
+	default:
+		if (error) {
+			*error = "Unknown error";
+		}
+		break;
+	}
+	return false;
+}

src/script/test/lua.c

@@ -0,0 +1,65 @@
+/* Copyright (c) 2013-2022 Jeffrey Pfau
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "util/test/suite.h"
+
+#include <mgba/internal/script/lua.h>
+
+M_TEST_SUITE_SETUP(mScriptLua) {
+	if (mSCRIPT_ENGINE_LUA->init) {
+		mSCRIPT_ENGINE_LUA->init(mSCRIPT_ENGINE_LUA);
+	}
+	return 0;
+}
+
+M_TEST_SUITE_TEARDOWN(mScriptLua) {
+	if (mSCRIPT_ENGINE_LUA->deinit) {
+		mSCRIPT_ENGINE_LUA->deinit(mSCRIPT_ENGINE_LUA);
+	}
+	return 0;
+}
+
+M_TEST_DEFINE(create) {
+	struct mScriptContext context;
+	mScriptContextInit(&context);
+	struct mScriptEngineContext* lua = mSCRIPT_ENGINE_LUA->create(mSCRIPT_ENGINE_LUA, &context);
+	lua->destroy(lua);
+	mScriptContextDeinit(&context);
+}
+
+M_TEST_DEFINE(loadGood) {
+	struct mScriptContext context;
+	mScriptContextInit(&context);
+	struct mScriptEngineContext* lua = mSCRIPT_ENGINE_LUA->create(mSCRIPT_ENGINE_LUA, &context);
+
+	const char* program = "-- test\n";
+	struct VFile* vf = VFileFromConstMemory(program, strlen(program));
+	const char* error = NULL;
+	assert_true(lua->load(lua, vf, &error));
+	assert_null(error);
+
+	lua->destroy(lua);
+	mScriptContextDeinit(&context);
+}
+
+M_TEST_DEFINE(loadSyntax) {
+	struct mScriptContext context;
+	mScriptContextInit(&context);
+	struct mScriptEngineContext* lua = mSCRIPT_ENGINE_LUA->create(mSCRIPT_ENGINE_LUA, &context);
+
+	const char* program = "Invalid syntax! )\n";
+	struct VFile* vf = VFileFromConstMemory(program, strlen(program));
+	const char* error = NULL;
+	assert_false(lua->load(lua, vf, &error));
+	assert_non_null(error);
+
+	lua->destroy(lua);
+	mScriptContextDeinit(&context);
+}
+
+M_TEST_SUITE_DEFINE_SETUP_TEARDOWN(mScriptLua,
+	cmocka_unit_test(create),
+	cmocka_unit_test(loadGood),
+	cmocka_unit_test(loadSyntax))