Scripting: Add root scope function for engines

include/mgba/script/context.h

@@ -55,6 +55,7 @@ struct mScriptEngineContext {
 
 	bool (*setGlobal)(struct mScriptEngineContext*, const char* name, struct mScriptValue*);
 	struct mScriptValue* (*getGlobal)(struct mScriptEngineContext*, const char* name);
+	struct mScriptValue* (*rootScope)(struct mScriptEngineContext*);
 
 	bool (*load)(struct mScriptEngineContext*, const char* filename, struct VFile*);
 	bool (*run)(struct mScriptEngineContext*);

src/script/engines/lua.c

@@ -25,6 +25,7 @@ static void _luaDestroy(struct mScriptEngineContext*);
 static bool _luaIsScript(struct mScriptEngineContext*, const char*, struct VFile*);
 static struct mScriptValue* _luaGetGlobal(struct mScriptEngineContext*, const char* name);
 static bool _luaSetGlobal(struct mScriptEngineContext*, const char* name, struct mScriptValue*);
+static struct mScriptValue* _luaRootScope(struct mScriptEngineContext*);
 static bool _luaLoad(struct mScriptEngineContext*, const char*, struct VFile*);
 static bool _luaRun(struct mScriptEngineContext*);
 static const char* _luaGetError(struct mScriptEngineContext*);
@@ -214,6 +215,7 @@ static const int _mScriptSocketNumErrors = sizeof(_mScriptSocketErrors) / sizeof
 
 #if LUA_VERSION_NUM < 502
 #define luaL_traceback(L, M, S, level) lua_pushstring(L, S)
+#define lua_pushglobaltable(L) lua_pushvalue(L, LUA_GLOBALSINDEX)
 #endif
 
 const struct mScriptType mSTLuaFunc = {
@@ -294,6 +296,7 @@ struct mScriptEngineContext* _luaCreate(struct mScriptEngine2* engine, struct mS
 		.isScript = _luaIsScript,
 		.getGlobal = _luaGetGlobal,
 		.setGlobal = _luaSetGlobal,
+		.rootScope = _luaRootScope,
 		.load = _luaLoad,
 		.run = _luaRun,
 		.getError = _luaGetError
@@ -395,6 +398,24 @@ bool _luaSetGlobal(struct mScriptEngineContext* ctx, const char* name, struct mS
 	return true;
 }
 
+struct mScriptValue* _luaRootScope(struct mScriptEngineContext* ctx) {
+	struct mScriptEngineContextLua* luaContext = (struct mScriptEngineContextLua*) ctx;
+
+	struct mScriptValue* list = mScriptValueAlloc(mSCRIPT_TYPE_MS_LIST);
+	lua_pushglobaltable(luaContext->lua);
+	lua_pushnil(luaContext->lua);
+	while (lua_next(luaContext->lua, -2) != 0) {
+		struct mScriptValue* key;
+
+		lua_pop(luaContext->lua, 1);
+		key = _luaCoerce(luaContext, false);
+		mScriptValueWrap(key, mScriptListAppend(list->value.list));
+	}
+	lua_pop(luaContext->lua, 1);
+
+	return list;
+}
+
 struct mScriptValue* _luaCoerceFunction(struct mScriptEngineContextLua* luaContext) {
 	struct mScriptValue* value = mScriptValueAlloc(&mSTLuaFunc);
 	struct mScriptFunction* fn = calloc(1, sizeof(*fn));

src/script/test/lua.c

@@ -259,6 +259,63 @@ M_TEST_DEFINE(setGlobal) {
 	mScriptContextDeinit(&context);
 }
 
+M_TEST_DEFINE(rootScope) {
+	SETUP_LUA;
+
+	struct mScriptValue* baseline = mScriptValueAlloc(mSCRIPT_TYPE_MS_TABLE);
+
+	struct mScriptValue* val;
+	val = lua->rootScope(lua);
+	assert_non_null(val);
+	assert_int_equal(val->type->base, mSCRIPT_TYPE_LIST);
+
+	struct mScriptValue one = mSCRIPT_MAKE_S32(1);
+	size_t i;
+	for (i = 0; i < mScriptListSize(val->value.list); ++i) {
+		struct mScriptValue* key = mScriptListGetPointer(val->value.list, i);
+		if (key->type->base == mSCRIPT_TYPE_WRAPPER) {
+			key = mScriptValueUnwrap(key);
+		}
+		mScriptTableInsert(baseline, key, &one);
+	}
+	mScriptValueDeref(val);
+
+	TEST_PROGRAM("foo = 1; bar = 2;");
+
+	bool fooFound = false;
+	bool barFound = false;
+
+	val = lua->rootScope(lua);
+	assert_non_null(val);
+	assert_int_equal(val->type->base, mSCRIPT_TYPE_LIST);
+	assert_int_equal(mScriptListSize(val->value.list), mScriptTableSize(baseline) + 2);
+
+	for (i = 0; i < mScriptListSize(val->value.list); ++i) {
+		struct mScriptValue* key = mScriptListGetPointer(val->value.list, i);
+		if (key->type->base == mSCRIPT_TYPE_WRAPPER) {
+			key = mScriptValueUnwrap(key);
+		}
+		if (mScriptTableLookup(baseline, key)) {
+			continue;
+		}
+		assert_int_equal(key->type->base, mSCRIPT_TYPE_STRING);
+
+		if (strncmp(key->value.string->buffer, "foo", key->value.string->size) == 0) {
+			fooFound = true;
+		}
+		if (strncmp(key->value.string->buffer, "bar", key->value.string->size) == 0) {
+			barFound = true;
+		}
+	}
+	mScriptValueDeref(val);
+
+	assert_true(fooFound);
+	assert_true(barFound);
+
+	mScriptValueDeref(baseline);
+	mScriptContextDeinit(&context);
+}
+
 M_TEST_DEFINE(callLuaFunc) {
 	SETUP_LUA;
 
@@ -658,6 +715,7 @@ M_TEST_SUITE_DEFINE_SETUP_TEARDOWN(mScriptLua,
 	cmocka_unit_test(runNop),
 	cmocka_unit_test(getGlobal),
 	cmocka_unit_test(setGlobal),
+	cmocka_unit_test(rootScope),
 	cmocka_unit_test(callLuaFunc),
 	cmocka_unit_test(callCFunc),
 	cmocka_unit_test(globalStructFieldGet),