From 5a24eaabb25fc45ce7b60c991c19139d947f300c Mon Sep 17 00:00:00 2001 From: Přemysl Janouch Date: Thu, 28 Oct 2010 00:31:20 +0200 Subject: Made Lua symbol registration more robust. --- src/ld-lua-symbol.c | 7 ++- src/ld-lua.c | 120 ++++++++++++++++++++++++++++++++++++---------------- 2 files changed, 89 insertions(+), 38 deletions(-) diff --git a/src/ld-lua-symbol.c b/src/ld-lua-symbol.c index cdc512f..363c5cd 100644 --- a/src/ld-lua-symbol.c +++ b/src/ld-lua-symbol.c @@ -70,8 +70,11 @@ ld_lua_symbol_finalize (GObject *gobject) self = LD_LUA_SYMBOL (gobject); - ld_lua_private_unregister (self->priv->lua, self); - g_object_unref (self->priv->lua); + if (self->priv->lua) + { + ld_lua_private_unregister (self->priv->lua, self); + g_object_unref (self->priv->lua); + } if (self->priv->name) g_free (self->priv->name); diff --git a/src/ld-lua.c b/src/ld-lua.c index de30a6d..8fadf20 100644 --- a/src/ld-lua.c +++ b/src/ld-lua.c @@ -91,8 +91,10 @@ static int ld_lua_private_unregister_cb (lua_State *L); static int ld_lua_logdiag_register (lua_State *L); + +static int process_registration (lua_State *L); static gchar *get_translation (lua_State *L, int index); -static void read_symbol_area (lua_State *L, int index, LdSymbolArea *area); +static gboolean read_symbol_area (lua_State *L, int index, LdSymbolArea *area); static luaL_Reg ld_lua_logdiag_lib[] = { @@ -230,6 +232,7 @@ ld_lua_check_file (LdLua *self, const gchar *filename) * @self: An #LdLua object. * @filename: The file to be loaded. * @callback: A callback for newly registered symbols. + * The callee is responsible for referencing the symbol. * @user_data: User data to be passed to the callback. * * Loads a file and creates #LdLuaSymbol objects for contained symbols. @@ -301,7 +304,7 @@ ld_lua_private_draw (LdLua *self, LdLuaSymbol *symbol, cairo_t *cr) if (lua_cpcall (self->priv->L, ld_lua_private_draw_cb, &data)) { g_warning ("Lua error: %s", lua_tostring (self->priv->L, -1)); - lua_remove (self->priv->L, -1); + lua_pop (self->priv->L, 1); } } @@ -342,7 +345,7 @@ ld_lua_private_unregister (LdLua *self, LdLuaSymbol *symbol) if (lua_cpcall (self->priv->L, ld_lua_private_unregister_cb, symbol)) { g_warning ("Lua error: %s", lua_tostring (self->priv->L, -1)); - lua_remove (self->priv->L, -1); + lua_pop (self->priv->L, 1); } } @@ -359,53 +362,91 @@ ld_lua_private_unregister_cb (lua_State *L) /* ===== Application library =============================================== */ -/* XXX: This function is damn too long. */ static int ld_lua_logdiag_register (lua_State *L) { LdLuaData *ud; LdLuaSymbol *symbol; - const gchar *name; - gchar *human_name; lua_getfield (L, LUA_REGISTRYINDEX, LD_LUA_DATA_INDEX); ud = lua_touserdata (L, -1); lua_pop (L, 1); g_return_val_if_fail (ud != NULL, 0); - /* Check and retrieve arguments. */ - name = lua_tostring (L, 1); - if (!name) - luaL_error (L, "register: bad or missing argument #%d", 1); - if (!lua_istable (L, 2)) - luaL_error (L, "register: bad or missing argument #%d", 2); - if (!lua_istable (L, 3)) - luaL_error (L, "register: bad or missing argument #%d", 3); - if (!lua_istable (L, 4)) - luaL_error (L, "register: bad or missing argument #%d", 4); - if (!lua_isfunction (L, 5)) - luaL_error (L, "register: bad or missing argument #%d", 5); - - /* Create a symbol using the given parameters. */ - /* XXX: If an error occurs, this object will not be freed. */ symbol = g_object_new (LD_TYPE_LUA_SYMBOL, NULL); - symbol->priv->lua = ud->self; - g_object_ref (ud->self); - symbol->priv->name = g_strdup (name); + /* Use a protected environment, so script errors won't cause leaking + * of the symbol object. Only the failure of one of the following three + * function calls may cause the symbol to leak. + */ + lua_pushlightuserdata (L, symbol); + lua_pushcclosure (L, process_registration, 1); + lua_insert (L, 1); + + /* On the stack, there are function arguments plus the function itself. */ + if (lua_pcall (L, lua_gettop (L) - 1, 0, 0)) + { + luaL_where (L, 1); + lua_insert (L, -2); + lua_concat (L, 2); + + g_warning ("Lua symbol registration failed: %s", + lua_tostring (L, -1)); + lua_pushboolean (L, FALSE); + } + else + { + /* We don't want an extra LdLua reference either. */ + symbol->priv->lua = ud->self; + g_object_ref (ud->self); + + ud->load_callback (LD_SYMBOL (symbol), ud->load_user_data); + lua_pushboolean (L, TRUE); + } + g_object_unref (symbol); + + return 1; +} + +/* + * process_registration: + * @L: A Lua state. + * + * Parse arguments, write them to a symbol object and register the object. + */ +static int +process_registration (lua_State *L) +{ + LdLuaSymbol *symbol; + const gchar *name; + gchar *human_name; + + int i, type, types[] = + {LUA_TSTRING, LUA_TTABLE, LUA_TTABLE, LUA_TTABLE, LUA_TFUNCTION}; + int n_args_needed = sizeof (types) / sizeof (int); + + if (lua_gettop (L) < n_args_needed) + return luaL_error (L, "Too few arguments."); + + for (i = 0; i < n_args_needed; i++) + if ((type = lua_type (L, i + 1)) != types[i]) + return luaL_error (L, "Bad type of argument #%d." + " Expected %s, got %s.", i + 1, + lua_typename (L, types[i]), lua_typename (L, type)); + + symbol = LD_LUA_SYMBOL (lua_touserdata (L, lua_upvalueindex (1))); + symbol->priv->name = g_strdup (lua_tostring (L, 1)); human_name = get_translation (L, 2); if (!human_name) human_name = g_strdup (name); symbol->priv->human_name = human_name; - /* TODO: Check the values. */ - read_symbol_area (L, 3, &symbol->priv->area); + if (!read_symbol_area (L, 3, &symbol->priv->area)) + return luaL_error (L, "Malformed symbol area array."); - /* TODO: Read and set the terminals (they're in a table). */ - lua_pushvalue (L, 4); + /* TODO: Read and set the terminals. */ - /* Create an entry in the symbol table. */ lua_getfield (L, LUA_REGISTRYINDEX, LD_LUA_SYMBOLS_INDEX); lua_pushlightuserdata (L, symbol); @@ -414,11 +455,6 @@ ld_lua_logdiag_register (lua_State *L) lua_setfield (L, -2, "render"); lua_settable (L, -3); - - /* The caller is responsible for referencing the symbol. */ - ud->load_callback (LD_SYMBOL (symbol), ud->load_user_data); - g_object_unref (symbol); - return 0; } @@ -459,24 +495,36 @@ get_translation (lua_State *L, int index) * @area: Where the area will be returned. * * Read a symbol area from a Lua table. + * + * Return value: TRUE on success, FALSE on failure. */ -static void +static gboolean read_symbol_area (lua_State *L, int index, LdSymbolArea *area) { if (lua_objlen (L, index) != 4) - return; + return FALSE; lua_rawgeti (L, index, 1); + if (!lua_isnumber (L, -1)) + return FALSE; area->x1 = lua_tonumber (L, -1); lua_rawgeti (L, index, 2); + if (!lua_isnumber (L, -1)) + return FALSE; area->y1 = lua_tonumber (L, -1); lua_rawgeti (L, index, 3); + if (!lua_isnumber (L, -1)) + return FALSE; area->x2 = lua_tonumber (L, -1); lua_rawgeti (L, index, 4); + if (!lua_isnumber (L, -1)) + return FALSE; area->y2 = lua_tonumber (L, -1); + + return TRUE; } /* ===== Cairo ============================================================= */ -- cgit v1.2.3-70-g09d2