lua: drop compatibility to 5.1 to allow for luajit

Part-of: <https://gitlab.freedesktop.org/libinput/libinput/-/merge_requests/1192>

.gitlab-ci.yml

@@ -98,11 +98,11 @@ variables:
   # See the documentation here:                                                 #
   # https://wayland.freedesktop.org/libinput/doc/latest/building.html           #
   ###############################################################################
-  FEDORA_PACKAGES:  'git-core gcc gcc-c++ pkgconf-pkg-config meson check-devel libudev-devel libevdev-devel doxygen graphviz python3-sphinx python3-recommonmark python3-sphinx_rtd_theme python3-pytest-xdist libwacom-devel cairo-devel gtk4-devel glib2-devel mtdev-devel diffutils wayland-protocols-devel black clang clang-tools-extra jq rpmdevtools valgrind systemd-udev qemu-img qemu-system-x86-core qemu-system-aarch64-core jq python3-click python3-rich virtme-ng lua-devel'
+  FEDORA_PACKAGES:  'git-core gcc gcc-c++ pkgconf-pkg-config meson check-devel libudev-devel libevdev-devel doxygen graphviz python3-sphinx python3-recommonmark python3-sphinx_rtd_theme python3-pytest-xdist libwacom-devel cairo-devel gtk4-devel glib2-devel mtdev-devel diffutils wayland-protocols-devel black clang clang-tools-extra jq rpmdevtools valgrind systemd-udev qemu-img qemu-system-x86-core qemu-system-aarch64-core jq python3-click python3-rich virtme-ng luajit-devel'
-  DEBIAN_PACKAGES:  'git gcc g++ pkg-config meson check libudev-dev libevdev-dev doxygen graphviz python3-sphinx python3-recommonmark python3-sphinx-rtd-theme python3-pytest-xdist libwacom-dev libcairo2-dev libgtk-3-dev libglib2.0-dev libmtdev-dev curl lua5.4-dev'
+  DEBIAN_PACKAGES:  'git gcc g++ pkg-config meson check libudev-dev libevdev-dev doxygen graphviz python3-sphinx python3-recommonmark python3-sphinx-rtd-theme python3-pytest-xdist libwacom-dev libcairo2-dev libgtk-3-dev libglib2.0-dev libmtdev-dev curl libluajit-5.1-dev'
-  UBUNTU_PACKAGES:  'git gcc g++ pkg-config meson check libudev-dev libevdev-dev doxygen graphviz python3-sphinx python3-recommonmark python3-sphinx-rtd-theme python3-pytest-xdist libwacom-dev libcairo2-dev libgtk-3-dev libglib2.0-dev libmtdev-dev lua5.4-dev'
+  UBUNTU_PACKAGES:  'git gcc g++ pkg-config meson check libudev-dev libevdev-dev doxygen graphviz python3-sphinx python3-recommonmark python3-sphinx-rtd-theme python3-pytest-xdist libwacom-dev libcairo2-dev libgtk-3-dev libglib2.0-dev libmtdev-dev libluajit-5.1-dev'
-  ARCH_PACKAGES:    'git gcc pkgconfig meson check libsystemd libevdev python-pytest-xdist libwacom gtk4 mtdev diffutils lua'
+  ARCH_PACKAGES:    'git gcc pkgconfig meson check libsystemd libevdev python-pytest-xdist libwacom gtk4 mtdev diffutils luajit'
-  ALPINE_PACKAGES:  'git gcc build-base pkgconfig meson check-dev eudev-dev libevdev-dev libwacom-dev cairo-dev gtk4.0-dev mtdev-dev bash lua5.4-dev'
+  ALPINE_PACKAGES:  'git gcc build-base pkgconfig meson check-dev eudev-dev libevdev-dev libwacom-dev cairo-dev gtk4.0-dev mtdev-dev bash luajit-dev'
   FREEBSD_PACKAGES: 'git pkgconf meson libepoll-shim libudev-devd libevdev libwacom gtk3 libmtdev bash wayland'
   ############################ end of package lists #############################
 
@@ -110,12 +110,12 @@ variables:
   # changing these will force rebuilding the associated image
   # Note: these tags have no meaning and are not tied to a particular
   # libinput version
-  FEDORA_TAG:  '2025-05-20.0'
+  FEDORA_TAG:  '2025-08-01.0'
-  DEBIAN_TAG:  '2025-05-20.0'
+  DEBIAN_TAG:  '2025-08-01.0'
-  UBUNTU_TAG:  '2025-05-20.0'
+  UBUNTU_TAG:  '2025-08-01.0'
-  ARCH_TAG:    '2025-05-20.0'
+  ARCH_TAG:    '2025-08-01.0'
-  ALPINE_TAG:  '2025-05-20.0'
+  ALPINE_TAG:  '2025-08-01.0'
-  FREEBSD_TAG: '2025-05-20.0'
+  FREEBSD_TAG: '2025-08-01.0'
 
   FDO_UPSTREAM_REPO: libinput/libinput
 

.gitlab-ci/config.yml

@@ -3,7 +3,7 @@
 #
 
 # We're happy to rebuild all containers when one changes.
-.default_tag: &default_tag '2025-05-20.0'
+.default_tag: &default_tag '2025-08-01.0'
 
 distributions:
   - name: fedora
@@ -50,7 +50,7 @@ distributions:
       - python3-click
       - python3-rich
       - virtme-ng
-      - lua-devel
+      - luajit-devel
   - name: debian
     tag: *default_tag
     versions:
@@ -76,7 +76,7 @@ distributions:
       - libglib2.0-dev
       - libmtdev-dev
       - curl            # for the coverity job
-      - lua5.4-dev
+      - libluajit-5.1-dev
   - name: ubuntu
     tag: *default_tag
     versions:
@@ -101,7 +101,7 @@ distributions:
       - libgtk-3-dev
       - libglib2.0-dev
       - libmtdev-dev
-      - lua5.4-dev
+      - libluajit-5.1-dev
   - name: arch
     tag: *default_tag
     versions:
@@ -119,7 +119,7 @@ distributions:
       - gtk4
       - mtdev
       - diffutils
-      - lua
+      - luajit
     build:
       extra_variables:
         - "MESON_ARGS: '-Ddocumentation=false'" # python-recommonmark is no longer in the repos
@@ -140,7 +140,7 @@ distributions:
       - gtk4.0-dev
       - mtdev-dev
       - bash
-      - lua5.4-dev
+      - luajit-dev
     build:
       extra_variables:
         - "MESON_ARGS: '-Ddocumentation=false' # alpine does not have python-recommonmark"

doc/user/lua-plugins.rst

@@ -9,7 +9,7 @@ of devices. For example, a plugin may add or remove axes and/or buttons on a
 device and/or modify the event stream seen by this device before it is passed
 to libinput.
 
-Plugins are implemented in `Lua <https://www.lua.org/>`_ (version 5.4 or later)
+Plugins are implemented in `Lua <https://www.lua.org/>`_ (version 5.1)
 and are typically loaded from ``/usr/lib{64}/libinput/plugins`` and
 ``/etc/libinput/plugins``. Plugins are loaded in alphabetical order and where
 multiple plugins share the same file name, the one in the highest precedence
@@ -20,7 +20,7 @@ Plugins are run sequentially in ascending sort-order (i.e. ``00-foo.lua`` runs
 before ``10-bar.lua``) and each plugin sees the state left by any previous
 plugins.
 
-See the `Lua Reference manual <https://www.lua.org/manual/5.4/manual.html>`_ for
+See the `Lua Reference manual <https://www.lua.org/manual/5.1/manual.html>`_ for
 details on the Lua language.
 
 .. note:: Plugins are **not** loaded by default, it is up to the compositor

meson.build

@@ -168,8 +168,7 @@ dep_libevdev = dependency('libevdev', version: '>= 1.10.0')
 dep_lm = cc.find_library('m', required : false)
 dep_rt = cc.find_library('rt', required : false)
 
-dep_lua = dependency('lua-5.4', 'lua5.4', 'lua',
+dep_lua = dependency(get_option('lua-interpreter'),
-		     version : '>= 5.4',
 		     required : get_option('lua-plugins'))
 have_lua = dep_lua.found()
 config_h.set10('HAVE_LUA', have_lua)
@@ -184,6 +183,11 @@ summary({
 	section : 'Plugins',
 	bool_yn : true)
 
+if have_lua
+	summary({'Lua Interpreter' : get_option('lua-interpreter')},
+		section : 'Plugins')
+endif
+
 # Include directories
 includes_include = include_directories('include')
 includes_src = include_directories('src')

meson_options.txt

@@ -46,3 +46,7 @@ option('lua-plugins',
 	type: 'feature',
 	value: 'auto',
 	description: 'Enable support for Lua plugins')
+option('lua-interpreter',
+	type: 'string',
+	value: 'luajit',
+	description: 'The Lua interpreter to use (pkgconfig name)')

src/libinput-plugin-lua.c

@@ -284,7 +284,18 @@ libinput_lua_pcall(struct libinput_lua_plugin *plugin, int narg, int nres)
 {
 	lua_State *L = plugin->L;
 
-	int rc = lua_pcall(L, narg, nres, 0);
+	lua_pushvalue(L, -(narg + 1)); /* Copy the function */
+	lua_pushvalue(L, plugin->sandbox_table_idx);
+	/* Now set the sandbox environment for the function we're about to call */
+	int rc = lua_setfenv(L, -2) == 1 ? LUA_OK : LUA_ERRRUN;
+	if (rc == LUA_OK) {
+		/* Replace original function with sandboxed one */
+		lua_replace(L, -(narg + 2));
+		/* Now call the function */
+		rc = lua_pcall(L, narg, nres, 0);
+	} else {
+		lua_pushstring(L, "Failed to set up sandbox");
+	}
 	if (rc != LUA_OK) {
 		auto libinput_plugin = plugin->parent;
 		const char *errormsg = lua_tostring(L, -1);
@@ -1114,20 +1125,6 @@ libinput_lua_plugin_run(struct libinput_plugin *libinput_plugin)
 {
 	struct libinput_lua_plugin *plugin =
 		libinput_plugin_get_user_data(libinput_plugin);
-	struct lua_State *L = plugin->L;
-
-	/* Main entry point into the plugin, so we need to push our sandbox
-	 * as _ENV. This only needs to be done here because all other entry
-	 * points into the Lua script are callbacks that are set up during
-	 * this run (and thus share the _ENV)
-	 */
-	lua_pushvalue(L, plugin->sandbox_table_idx);
-	const char *upval = lua_setupvalue(L, -2, 1);
-	if (!upval || !streq(upval, "_ENV")) {
-		plugin_log_bug_libinput(libinput_plugin, "Failed to set up sandbox\n");
-		libinput_plugin_unregister(libinput_plugin);
-		return;
-	}
 
 	if (libinput_lua_pcall(plugin, 0, 0) && !plugin->register_called) {
 		plugin_log_bug(libinput_plugin,
@@ -1214,7 +1211,7 @@ libinput_lua_plugin_init_lua(struct libinput *libinput,
 	if (!L)
 		return NULL;
 
-	/* This will be our _ENV later, see libinput_lua_pcall */
+	/* This will be our our global env later, see libinput_lua_pcall() */
 	lua_newtable(L);
 	int sandbox_table_idx = lua_gettop(L);
 	plugin->sandbox_table_idx = sandbox_table_idx;
@@ -1227,32 +1224,36 @@ libinput_lua_plugin_init_lua(struct libinput *libinput,
 	 * all have their own individual sandbox.
 	 */
 
-	luaL_requiref(L, LUA_GNAME, luaopen_base, 0);
+	luaopen_base(L);
 	static const char *allowed_funcs[] = {
-		"assert", "error", "ipairs",   "next",     "pcall", "pairs",  "pairs",
+		"assert", "error",    "ipairs",   "next", "pcall",  "pairs",
-		"print",  "warn",  "tonumber", "tostring", "type",  "xpcall",
+		"print",  "tonumber", "tostring", "type", "unpack", "xpcall",
 	};
 	ARRAY_FOR_EACH(allowed_funcs, func) {
-		lua_getfield(L, -1, *func);
+		lua_getglobal(L, *func);
 		lua_setfield(L, sandbox_table_idx, *func);
 	}
 
 	/* Math is fine as a whole */
-	luaL_requiref(L, LUA_MATHLIBNAME, luaopen_math, 0);
+	luaopen_math(L);
+	lua_getglobal(L, "math");
 	lua_setfield(L, sandbox_table_idx, "math");
 
 	/* Table is fine as a whole */
-	luaL_requiref(L, LUA_TABLIBNAME, luaopen_table, 0);
+	luaopen_table(L);
+	lua_getglobal(L, "table");
 	lua_setfield(L, sandbox_table_idx, "table");
 
-	/* Table is fine as a whole */
+	/* String is fine as a whole */
-	luaL_requiref(L, LUA_STRLIBNAME, luaopen_table, 0);
+	luaopen_string(L);
+	lua_getglobal(L, "string");
 	lua_setfield(L, sandbox_table_idx, "string");
 
 	/* Override metatable to prevent access to unregistered globals */
-	lua_pushvalue(L, sandbox_table_idx);
 	lua_newtable(L);
-	lua_setfield(L, -2, "__index");
+	lua_pushstring(L, "__index");
+	lua_pushnil(L);
+	lua_settable(L, -3);
 	lua_setmetatable(L, sandbox_table_idx);
 
 	/* Our objects */
@@ -1260,7 +1261,8 @@ libinput_lua_plugin_init_lua(struct libinput *libinput,
 	evdevdevice_init(L);
 
 	/* Our globals */
-	luaL_newlib(L, log_funcs);
+	lua_newtable(L);
+	luaL_register(L, "log", log_funcs);
 	lua_setfield(L, sandbox_table_idx, "log");
 	libinput_lua_init_evdev_global(L, sandbox_table_idx);