client: Allow loading module's module.lua via require("buildat/module/<name>")

client/extensions.lua

@@ -6,6 +6,7 @@ local log = buildat.Logger("__client/extensions")
 -- Extension interfaces, indexed by extension name
 local loaded_extensions = {}
 
+-- Called by this file and client/sandbox.lua
 function __buildat_require_extension(name)
 	log:debug("__buildat_require_extension(\""..name.."\")")
 	if loaded_extensions[name] then
@@ -28,6 +29,8 @@ end
 
 -- Don't use package.loaders because for whatever reason it doesn't work in the
 -- Windows version at least in Wine
+-- TODO: Was that due to the table indexing bug which was fixed by using LuaJIT
+--       instead of Lua?
 local old_require = require
 
 function require(name)

client/init.lua

@@ -82,6 +82,7 @@ dofile(__buildat_get_path("share").."/client/packet.lua")
 dofile(__buildat_get_path("share").."/client/extensions.lua")
 dofile(__buildat_get_path("share").."/client/sandbox.lua")
 dofile(__buildat_get_path("share").."/client/replication.lua")
+dofile(__buildat_get_path("share").."/client/modules.lua")
 
 local test = require("buildat/extension/test")
 test.f()

client/modules.lua

@@ -0,0 +1,25 @@
+-- Buildat: client/modules.lua
+-- http://www.apache.org/licenses/LICENSE-2.0
+-- Copyright 2014 Perttu Ahola <celeron55@gmail.com>
+local log = buildat.Logger("__client/modules")
+
+-- Module interfaces, indexed by module name
+local loaded_modules = {}
+
+-- Called by client/sandbox.lua
+function __buildat_require_module(name)
+	log:debug("__buildat_require_module(\""..name.."\")")
+	if loaded_modules[name] then
+		return loaded_modules[name]
+	end
+	local status, err, interface = buildat.run_script_file(name.."/module.lua")
+	if not status then
+		log:error("Module could not be loaded: "..name..": "..err)
+		return nil
+	end
+	loaded_modules[name] = interface
+	return interface
+end
+
+-- vim: set noet ts=4 sw=4:
+

client/sandbox.lua

@@ -69,6 +69,16 @@ __buildat_sandbox_environment.require = function(name)
 		log:verbose("Loaded extension \""..name.."\"")
 		return unsafe.safe
 	end
+	-- Allow loading the client-side parts of modules
+	local m = string.match(name, '^buildat/module/([a-zA-Z0-9_]+)$')
+	if m then
+		local interface = __buildat_require_module(m)
+		if interface == nil then
+			error("require: Cannot load module: \""..m.."\"")
+		end
+		log:verbose("Loaded module \""..name.."\"")
+		return interface
+	end
 	-- Disallow loading anything else
 	error("require: \""..name.."\" not found in sandbox")
 end
@@ -151,32 +161,40 @@ end
 local function run_function_in_sandbox(untrusted_function, sandbox)
 	sandbox = wrap_globals(sandbox)
 	setfenv(untrusted_function, sandbox)
-	return __buildat_pcall(untrusted_function)
+	local retval = nil
+	local status, err = __buildat_pcall(function()
+		retval = untrusted_function()
+	end)
+	return status, err, retval
 end
 
 function __buildat_run_function_in_sandbox(untrusted_function)
-	local status, err = run_function_in_sandbox(untrusted_function, __buildat_sandbox_environment)
+	local status, err, retval = run_function_in_sandbox(
+			untrusted_function, __buildat_sandbox_environment)
 	if status == false then
 		log:error("Failed to run function:\n"..err)
-		return false
 	end
-	return true
+	return status, err, retval
 end
 
 local function run_code_in_sandbox(untrusted_code, sandbox, chunkname)
-	if untrusted_code:byte(1) == 27 then return false, "binary bytecode prohibited" end
+	if untrusted_code:byte(1) == 27 then
+		return false, "binary bytecode prohibited", nil
+	end
 	local untrusted_function, message = loadstring(untrusted_code, chunkname)
-	if not untrusted_function then return false, message end
+	if not untrusted_function then
+		return false, message, nil
+	end
 	return run_function_in_sandbox(untrusted_function, sandbox)
 end
 
 function __buildat_run_code_in_sandbox(untrusted_code, chunkname)
-	local status, err = run_code_in_sandbox(untrusted_code, __buildat_sandbox_environment, chunkname)
+	local status, err, retval = run_code_in_sandbox(
+			untrusted_code, __buildat_sandbox_environment, chunkname)
 	if status == false then
 		log:error("Failed to run script:\n"..err)
-		return false
 	end
-	return true
+	return status, err, retval
 end
 
 function buildat.run_script_file(name)

doc/todo.txt

@@ -32,4 +32,4 @@ Buildat TODO
 - Precompiled mode
 - Singleplayer UI
 - Modules with no C++ code (eg. just a client-side library)
-- Show exceptions and errors on client using ui_utils.show_message_dialog
+- Show all exceptions and errors on client using ui_utils.show_message_dialog