lua: Expose a minimal set of errno values

modules/lua/Makefile.am

@@ -29,7 +29,8 @@ liblua_plugin_la_SOURCES = \
 	lua/libs/vlm.c \
 	lua/libs/volume.c \
 	lua/libs/xml.c \
-	lua/libs/io.c
+	lua/libs/io.c \
+	lua/libs/errno.c
 
 if HAVE_WIN32
 liblua_plugin_la_SOURCES += lua/libs/win.c

modules/lua/extension.c

@@ -853,6 +853,7 @@ static lua_State* GetLuaState( extensions_manager_t *p_mgr,
         luaopen_volume( L );
         luaopen_xml( L );
         luaopen_vlcio( L );
+        luaopen_errno( L );
 #if defined(_WIN32) && !VLC_WINSTORE_APP
         luaopen_win( L );
 #endif

modules/lua/intf.c

@@ -278,6 +278,7 @@ static int Start_LuaIntf( vlc_object_t *p_this, const char *name )
     luaopen_xml( L );
     luaopen_equalizer( L );
     luaopen_vlcio( L );
+    luaopen_errno( L );
 #if defined(_WIN32) && !VLC_WINSTORE_APP
     luaopen_win( L );
 #endif

modules/lua/libs.h

@@ -46,6 +46,7 @@ void luaopen_input_item( lua_State *L, input_item_t *item );
 void luaopen_xml( lua_State *L );
 void luaopen_equalizer( lua_State *L );
 void luaopen_vlcio( lua_State *L );
+void luaopen_errno( lua_State *L );
 #ifdef _WIN32
 void luaopen_win( lua_State *L );
 #endif

modules/lua/libs/errno.c

@@ -0,0 +1,48 @@
+/*****************************************************************************
+ * errno.c
+ *****************************************************************************
+ * Copyright (C) 2007-2018 the VideoLAN team
+ *
+ * Authors: Hugo Beauzée-Luyssen <hugo@beauzee.fr>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <errno.h>
+
+#include "../vlc.h"
+#include "../libs.h"
+
+void luaopen_errno( lua_State *L )
+{
+    lua_newtable( L );
+
+#define ADD_ERRNO_VALUE( value )  \
+    lua_pushinteger( L, value );  \
+    lua_setfield( L, -2, #value );
+
+    ADD_ERRNO_VALUE( ENOENT );
+    ADD_ERRNO_VALUE( EEXIST );
+    ADD_ERRNO_VALUE( EACCES );
+    ADD_ERRNO_VALUE( EINVAL );
+
+#undef ADD_ERRNO_VALUE
+
+    lua_setfield( L, -2, "errno" );
+}