1 files changed, 557 insertions, 0 deletions
diff --git a/engines/sword25/script/luascript.cpp b/engines/sword25/script/luascript.cpp
new file mode 100644
index 0000000000..aa2bdb9e06
--- /dev/null
+++ b/engines/sword25/script/luascript.cpp
@@ -0,0 +1,557 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+/*
+ * This code is based on Broken Sword 2.5 engine
+ *
+ * Copyright (c) Malte Thiesen, Daniel Queteschiner and Michael Elsdoerfer
+ *
+ * Licensed under GNU GPL v2
+ *
+ */
+
+#define BS_LOG_PREFIX "LUA"
+
+#include "common/array.h"
+#include "common/debug-channels.h"
+
+#include "sword25/sword25.h"
+#include "sword25/package/packagemanager.h"
+#include "sword25/script/luascript.h"
+#include "sword25/script/luabindhelper.h"
+
+#include "sword25/kernel/outputpersistenceblock.h"
+#include "sword25/kernel/inputpersistenceblock.h"
+
+#include "sword25/util/lua/lua.h"
+#include "sword25/util/lua/lualib.h"
+#include "sword25/util/lua/lauxlib.h"
+#include "sword25/util/pluto/pluto.h"
+
+namespace Sword25 {
+
+LuaScriptEngine::LuaScriptEngine(Kernel *KernelPtr) :
+	ScriptEngine(KernelPtr),
+	_state(0),
+	_pcallErrorhandlerRegistryIndex(0) {
+}
+
+LuaScriptEngine::~LuaScriptEngine() {
+	// Lua de-initialisation
+	if (_state)
+		lua_close(_state);
+}
+
+namespace {
+int panicCB(lua_State *L) {
+	BS_LOG_ERRORLN("Lua panic. Error message: %s", lua_isnil(L, -1) ? "" : lua_tostring(L, -1));
+	return 0;
+}
+
+void debugHook(lua_State *L, lua_Debug *ar) {
+	if (!lua_getinfo(L, "Sn", ar))
+		return;
+
+	debug("LUA: %s %s: %s %d", ar->namewhat, ar->name, ar->short_src, ar->currentline);
+}
+}
+
+bool LuaScriptEngine::init() {
+	// Lua-State initialisation, as well as standard libaries initialisation
+	_state = luaL_newstate();
+	if (!_state || ! registerStandardLibs() || !registerStandardLibExtensions()) {
+		BS_LOG_ERRORLN("Lua could not be initialized.");
+		return false;
+	}
+
+	// Register panic callback function
+	lua_atpanic(_state, panicCB);
+
+	// Error handler for lua_pcall calls
+	// The code below contains a local error handler function
+	const char errorHandlerCode[] =
+	    "local function ErrorHandler(message) "
+	    "	return message .. '\\n' .. debug.traceback('', 2) "
+	    "end "
+	    "return ErrorHandler";
+
+	// Compile the code
+	if (luaL_loadbuffer(_state, errorHandlerCode, strlen(errorHandlerCode), "PCALL ERRORHANDLER") != 0) {
+		// An error occurred, so dislay the reason and exit
+		BS_LOG_ERRORLN("Couldn't compile luaL_pcall errorhandler:\n%s", lua_tostring(_state, -1));
+		lua_pop(_state, 1);
+
+		return false;
+	}
+	// Running the code, the error handler function sets the top of the stack
+	if (lua_pcall(_state, 0, 1, 0) != 0) {
+		// An error occurred, so dislay the reason and exit
+		BS_LOG_ERRORLN("Couldn't prepare luaL_pcall errorhandler:\n%s", lua_tostring(_state, -1));
+		lua_pop(_state, 1);
+
+		return false;
+	}
+
+	// Place the error handler function in the Lua registry, and remember the index
+	_pcallErrorhandlerRegistryIndex = luaL_ref(_state, LUA_REGISTRYINDEX);
+
+	// Initialise the Pluto-Persistence library
+	luaopen_pluto(_state);
+	lua_pop(_state, 1);
+
+	// Initialize debugging callback
+	if (DebugMan.isDebugChannelEnabled(kDebugScript)) {
+		int mask = 0;
+		if ((gDebugLevel & 1) != 0)
+			mask |= LUA_MASKCALL;
+		if ((gDebugLevel & 2) != 0)
+			mask |= LUA_MASKRET;
+		if ((gDebugLevel & 4) != 0)
+			mask |= LUA_MASKLINE;
+
+		if (mask != 0)
+			lua_sethook(_state, debugHook, mask, 0);
+	}
+
+	BS_LOGLN("Lua initialized.");
+
+	return true;
+}
+
+bool LuaScriptEngine::executeFile(const Common::String &fileName) {
+#ifdef DEBUG
+	int __startStackDepth = lua_gettop(_state);
+#endif
+	debug(2, "LuaScriptEngine::executeFile(%s)", fileName.c_str());
+
+	// Get a pointer to the package manager
+	PackageManager *pPackage = Kernel::getInstance()->getPackage();
+	BS_ASSERT(pPackage);
+
+	// File read
+	uint fileSize;
+	byte *fileData = pPackage->getFile(fileName, &fileSize);
+	if (!fileData) {
+		BS_LOG_ERRORLN("Couldn't read \"%s\".", fileName.c_str());
+#ifdef DEBUG
+		BS_ASSERT(__startStackDepth == lua_gettop(_state));
+#endif
+		return false;
+	}
+
+	// Run the file content
+	if (!executeBuffer(fileData, fileSize, "@" + pPackage->getAbsolutePath(fileName))) {
+		// Release file buffer
+		delete[] fileData;
+#ifdef DEBUG
+		BS_ASSERT(__startStackDepth == lua_gettop(_state));
+#endif
+		return false;
+	}
+
+	// Release file buffer
+	delete[] fileData;
+
+#ifdef DEBUG
+	BS_ASSERT(__startStackDepth == lua_gettop(_state));
+#endif
+
+	return true;
+}
+
+bool LuaScriptEngine::executeString(const Common::String &code) {
+	return executeBuffer((byte *)code.c_str(), code.size(), "???");
+}
+
+namespace {
+
+void removeForbiddenFunctions(lua_State *L) {
+	static const char *FORBIDDEN_FUNCTIONS[] = {
+		"dofile",
+		0
+	};
+
+	const char **iterator = FORBIDDEN_FUNCTIONS;
+	while (*iterator) {
+		lua_pushnil(L);
+		lua_setfield(L, LUA_GLOBALSINDEX, *iterator);
+		++iterator;
+	}
+}
+}
+
+bool LuaScriptEngine::registerStandardLibs() {
+	luaL_openlibs(_state);
+	removeForbiddenFunctions(_state);
+	return true;
+}
+
+bool LuaScriptEngine::executeBuffer(const byte *data, uint size, const Common::String &name) const {
+	// Compile buffer
+	if (luaL_loadbuffer(_state, (const char *)data, size, name.c_str()) != 0) {
+		BS_LOG_ERRORLN("Couldn't compile \"%s\":\n%s", name.c_str(), lua_tostring(_state, -1));
+		lua_pop(_state, 1);
+
+		return false;
+	}
+
+	// Error handling function to be executed after the function is put on the stack
+	lua_rawgeti(_state, LUA_REGISTRYINDEX, _pcallErrorhandlerRegistryIndex);
+	lua_insert(_state, -2);
+
+	// Run buffer contents
+	if (lua_pcall(_state, 0, 0, -2) != 0) {
+		BS_LOG_ERRORLN("An error occured while executing \"%s\":\n%s.",
+		               name.c_str(),
+		               lua_tostring(_state, -1));
+		lua_pop(_state, 2);
+
+		return false;
+	}
+
+	// Remove the error handler function from the stack
+	lua_pop(_state, 1);
+
+	return true;
+}
+
+void LuaScriptEngine::setCommandLine(const Common::StringArray &commandLineParameters) {
+	lua_newtable(_state);
+
+	for (size_t i = 0; i < commandLineParameters.size(); ++i) {
+		lua_pushnumber(_state, i + 1);
+		lua_pushstring(_state, commandLineParameters[i].c_str());
+		lua_settable(_state, -3);
+	}
+
+	lua_setglobal(_state, "CommandLine");
+}
+
+namespace {
+const char *PERMANENTS_TABLE_NAME = "Permanents";
+
+// This array contains the name of global Lua objects that should not be persisted
+const char *STANDARD_PERMANENTS[] = {
+	"string",
+	"xpcall",
+	"package",
+	"tostring",
+	"print",
+	"os",
+	"unpack",
+	"require",
+	"getfenv",
+	"setmetatable",
+	"next",
+	"assert",
+	"tonumber",
+	"io",
+	"rawequal",
+	"collectgarbage",
+	"getmetatable",
+	"module",
+	"rawset",
+	"warning",
+	"math",
+	"debug",
+	"pcall",
+	"table",
+	"newproxy",
+	"type",
+	"coroutine",
+	"select",
+	"gcinfo",
+	"pairs",
+	"rawget",
+	"loadstring",
+	"ipairs",
+	"_VERSION",
+	"setfenv",
+	"load",
+	"error",
+	"loadfile",
+
+	"pairs_next",
+	"ipairs_next",
+	"pluto",
+	"Cfg",
+	"Translator",
+	"Persistence",
+	"CommandLine",
+	0
+};
+
+enum PERMANENT_TABLE_TYPE {
+	PTT_PERSIST,
+	PTT_UNPERSIST
+};
+
+bool pushPermanentsTable(lua_State *L, PERMANENT_TABLE_TYPE tableType) {
+	// Permanents-Table
+	lua_newtable(L);
+
+	// All standard permanents are inserted into this table
+	uint Index = 0;
+	while (STANDARD_PERMANENTS[Index]) {
+		// Permanents are placed onto the stack; if it does not exist, it is simply ignored
+		lua_getglobal(L, STANDARD_PERMANENTS[Index]);
+		if (!lua_isnil(L, -1)) {
+			// Name of the element as a unique value on the stack
+			lua_pushstring(L, STANDARD_PERMANENTS[Index]);
+
+			// If it is loaded, then it can be used
+			// In this case, the position of name and object are reversed on the stack
+			if (tableType == PTT_UNPERSIST)
+				lua_insert(L, -2);
+
+			// Make an entry in the table
+			lua_settable(L, -3);
+		} else {
+			// Pop nil value from stack
+			lua_pop(L, 1);
+		}
+
+		++Index;
+	}
+
+	// All registered C functions to be inserted into the table
+	// BS_LuaBindhelper places in the register a table in which all registered C functions
+	// are stored
+
+	// Table is put on the stack
+	lua_getfield(L, LUA_REGISTRYINDEX, PERMANENTS_TABLE_NAME);
+
+	if (!lua_isnil(L, -1)) {
+		// Iterate over all elements of the table
+		lua_pushnil(L);
+		while (lua_next(L, -2) != 0) {
+			// Value and index duplicated on the stack and changed in the sequence
+			lua_pushvalue(L, -1);
+			lua_pushvalue(L, -3);
+
+			// If it is loaded, then it can be used
+			// In this case, the position of name and object are reversed on the stack
+			if (tableType == PTT_UNPERSIST)
+				lua_insert(L, -2);
+
+			// Make an entry in the results table
+			lua_settable(L, -6);
+
+			// Pop value from the stack. The index is then ready for the next call to lua_next()
+			lua_pop(L, 1);
+		}
+	}
+
+	// Pop the C-Permanents table from the stack
+	lua_pop(L, 1);
+
+	// coroutine.yield must be registered in the extra-Permanents table because they
+	// are inactive coroutine C functions on the stack
+
+	// Function coroutine.yield placed on the stack
+	lua_getglobal(L, "coroutine");
+	lua_pushstring(L, "yield");
+	lua_gettable(L, -2);
+
+	// Store coroutine.yield with it's own unique value in the Permanents table
+	lua_pushstring(L, "coroutine.yield");
+
+	if (tableType == PTT_UNPERSIST)
+		lua_insert(L, -2);
+
+	lua_settable(L, -4);
+
+	// Coroutine table is popped from the stack
+	lua_pop(L, 1);
+
+	return true;
+}
+}
+
+namespace {
+int chunkwriter(lua_State *L, const void *p, size_t sz, void *ud) {
+	Common::Array<byte> & chunkData = *reinterpret_cast<Common::Array<byte> * >(ud);
+	const byte *buffer = reinterpret_cast<const byte *>(p);
+
+	while (sz--)
+		chunkData.push_back(*buffer++);
+
+	return 1;
+}
+}
+
+bool LuaScriptEngine::persist(OutputPersistenceBlock &writer) {
+	// Empty the Lua stack. pluto_persist() xepects that the stack is empty except for its parameters
+	lua_settop(_state, 0);
+
+	// Garbage Collection erzwingen.
+	lua_gc(_state, LUA_GCCOLLECT, 0);
+
+	// Permanents-Table is set on the stack
+	// pluto_persist expects these two items on the Lua stack
+	pushPermanentsTable(_state, PTT_PERSIST);
+	lua_getglobal(_state, "_G");
+
+	// Lua persists and stores the data in a Common::Array
+	Common::Array<byte> chunkData;
+	pluto_persist(_state, chunkwriter, &chunkData);
+
+	// Persistenzdaten in den Writer schreiben.
+	writer.writeByteArray(chunkData);
+
+	// Die beiden Tabellen vom Stack nehmen.
+	lua_pop(_state, 2);
+
+	return true;
+}
+
+namespace {
+
+struct ChunkreaderData {
+	void   *BufferPtr;
+	size_t  Size;
+	bool    BufferReturned;
+};
+
+const char *chunkreader(lua_State *L, void *ud, size_t *sz) {
+	ChunkreaderData &cd = *reinterpret_cast<ChunkreaderData *>(ud);
+
+	if (!cd.BufferReturned) {
+		cd.BufferReturned = true;
+		*sz = cd.Size;
+		return reinterpret_cast<const char *>(cd.BufferPtr);
+	} else {
+		return 0;
+	}
+}
+
+void clearGlobalTable(lua_State *L, const char **exceptions) {
+	// Iterate over all elements of the global table
+	lua_pushvalue(L, LUA_GLOBALSINDEX);
+	lua_pushnil(L);
+	while (lua_next(L, -2) != 0) {
+		// Now the value and the index of the current element is on the stack
+		// This value does not interest us, so it is popped from the stack
+		lua_pop(L, 1);
+
+		// Determine whether the item is set to nil, so you want to remove from the global table.
+		// For this will determine whether the element name is a string and is present in
+		// the list of exceptions
+		bool setElementToNil = true;
+		if (lua_isstring(L, -1)) {
+			const char *indexString = lua_tostring(L, -1);
+			const char **exceptionsWalker = exceptions;
+			while (*exceptionsWalker) {
+				if (strcmp(indexString, *exceptionsWalker) == 0)
+					setElementToNil = false;
+				++exceptionsWalker;
+			}
+		}
+
+		// If the above test showed that the item should be removed, it is removed by setting the value to nil.
+		if (setElementToNil) {
+			lua_pushvalue(L, -1);
+			lua_pushnil(L);
+			lua_settable(L, LUA_GLOBALSINDEX);
+		}
+	}
+
+	// Pop the Global table from the stack
+	lua_pop(L, 1);
+
+	// Perform garbage collection, so that all removed elements are deleted
+	lua_gc(L, LUA_GCCOLLECT, 0);
+}
+}
+
+bool LuaScriptEngine::unpersist(InputPersistenceBlock &reader) {
+	// Empty the Lua stack. pluto_persist() xepects that the stack is empty except for its parameters
+	lua_settop(_state, 0);
+
+	// Permanents table is placed on the stack. This has already happened at this point, because
+	// to create the table all permanents must be accessible. This is the case only for the
+	// beginning of the function, because the global table is emptied below
+	pushPermanentsTable(_state, PTT_UNPERSIST);
+
+	// All items from global table of _G and __METATABLES are removed.
+	// After a garbage collection is performed, and thus all managed objects deleted
+
+	// __METATABLES is not immediately removed becausen the Metatables are needed
+	// for the finalisers of objects.
+	static const char *clearExceptionsFirstPass[] = {
+		"_G",
+		"__METATABLES",
+		0
+	};
+	clearGlobalTable(_state, clearExceptionsFirstPass);
+
+	// In the second pass, the Metatables are removed
+	static const char *clearExceptionsSecondPass[] = {
+		"_G",
+		0
+	};
+	clearGlobalTable(_state, clearExceptionsSecondPass);
+
+	// Persisted Lua data
+	Common::Array<byte> chunkData;
+	reader.readByteArray(chunkData);
+
+	// Chunk-Reader initialisation. It is used with pluto_unpersist to restore read data
+	ChunkreaderData cd;
+	cd.BufferPtr = &chunkData[0];
+	cd.Size = chunkData.size();
+	cd.BufferReturned = false;
+
+	pluto_unpersist(_state, chunkreader, &cd);
+
+	// Permanents-Table is removed from stack
+	lua_remove(_state, -2);
+
+	// The read elements in the global table about
+	lua_pushnil(_state);
+	while (lua_next(_state, -2) != 0) {
+		// The referenec to the global table (_G) must not be overwritten, or ticks from Lua total
+		bool isGlobalReference = lua_isstring(_state, -2) && strcmp(lua_tostring(_state, -2), "_G") == 0;
+		if (!isGlobalReference) {
+			lua_pushvalue(_state, -2);
+			lua_pushvalue(_state, -2);
+
+			lua_settable(_state, LUA_GLOBALSINDEX);
+		}
+
+		// Pop value from the stack. The index is then ready for the next call to lua_next()
+		lua_pop(_state, 1);
+	}
+
+	// The table with the loaded data is popped from the stack
+	lua_pop(_state, 1);
+
+	// Force garbage collection
+	lua_gc(_state, LUA_GCCOLLECT, 0);
+
+	return true;
+}
+
+} // End of namespace Sword25