diff options
Diffstat (limited to 'engines/sword25/util/lua_unpersist.cpp')
| -rw-r--r-- | engines/sword25/util/lua_unpersist.cpp | 722 |
1 files changed, 722 insertions, 0 deletions
diff --git a/engines/sword25/util/lua_unpersist.cpp b/engines/sword25/util/lua_unpersist.cpp new file mode 100644 index 0000000000..ef0ef31041 --- /dev/null +++ b/engines/sword25/util/lua_unpersist.cpp @@ -0,0 +1,722 @@ +/* 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. + * + */ + +/** + * This code is heavily based on the Pluto code base. Copyright below + */ + +/* Tamed Pluto - Heavy-duty persistence for Lua + * Copyright (C) 2004 by Ben Sunshine-Hill, and released into the public + * domain. People making use of this software as part of an application + * are politely requested to email the author at sneftel@gmail.com + * with a brief description of the application, primarily to satisfy his + * curiosity. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY + * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, + * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE + * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + * + * Instrumented by Stefan Reich (info@luaos.net) + * for Mobile Lua (http://luaos.net/pages/mobile-lua.php) + */ + + +#include "sword25/util/lua_persistence.h" + +#include "sword25/util/double_serialization.h" +#include "sword25/util/lua_persistence_util.h" + +#include "common/stream.h" + +#include "lua/lobject.h" +#include "lua/lstate.h" +#include "lua/lgc.h" +#include "lua/lopcodes.h" + + +namespace Lua { + +struct UnSerializationInfo { + lua_State *luaState; + Common::ReadStream *readStream; +}; + +static void unpersist(UnSerializationInfo *info); + +static void unpersistBoolean(UnSerializationInfo *info); +static void unpersistNumber(UnSerializationInfo *info); +static void unpersistString(UnSerializationInfo *info); +static void unpersistTable(UnSerializationInfo *info, int index); +static void unpersistFunction(UnSerializationInfo *info, int index); +static void unpersistThread(UnSerializationInfo *info, int index); +static void unpersistProto(UnSerializationInfo *info, int index); +static void unpersistUpValue(UnSerializationInfo *info, int index); +static void unpersistUserData(UnSerializationInfo *info, int index); +static void unpersistPermanent(UnSerializationInfo *info, int index); + + +void unpersistLua(lua_State *luaState, Common::ReadStream *readStream) { + UnSerializationInfo info; + info.luaState = luaState; + info.readStream = readStream; + + // The process starts with the lua stack as follows: + // >>>>> permTbl + // That's the table of permanents + + // Make sure there is enough room on the stack + lua_checkstack(luaState, 3); + + // Create a table to hold indexes of everything thats already been read + lua_newtable(luaState); + // >>>>> permTbl indexTbl + + // Prevent garbage collection while we unserialize + lua_gc(luaState, LUA_GCSTOP, 0); + + // Unserialize the root object + unpersist(&info); + // >>>>> permTbl indexTbl rootObj + + // Re-start garbage collection + lua_gc(luaState, LUA_GCRESTART, 0); + + // Remove the indexTbl + lua_replace(luaState, 2); + // >>>>> permTbl rootObj +} + +/* The object is left on the stack. This is primarily used by unserialize, but + * may be used by GCed objects that may incur cycles in order to preregister + * the object. */ +static void registerObjectInIndexTable(UnSerializationInfo *info, int index) { + // >>>>> permTbl indexTbl ...... obj + + // Make sure there is enough room on the stack + lua_checkstack(info->luaState, 2); + + lua_pushlightuserdata(info->luaState, (void *)index); + // >>>>> permTbl indexTbl ...... obj index + + lua_pushvalue(info->luaState, -2); + // >>>>> permTbl indexTbl ...... obj index obj + + // Push the k/v pair into the indexTbl + lua_settable(info->luaState, 2); + // >>>>> permTbl indexTbl ...... obj +} + +static void unpersist(UnSerializationInfo *info) { + // >>>>> permTbl indexTbl ...... + + // Make sure there is enough room on the stack + lua_checkstack(info->luaState, 2); + + byte isARealValue = info->readStream->readByte(); + if (isARealValue) { + int index = info->readStream->readSint32LE(); + int type = info->readStream->readSint32LE(); + + switch (type) { + case LUA_TBOOLEAN: + unpersistBoolean(info); + break; + case LUA_TLIGHTUSERDATA: + // You can't serialize a pointer + // It would be meaningless on the next run + assert(0); + break; + case LUA_TNUMBER: + unpersistNumber(info); + break; + case LUA_TSTRING: + unpersistString(info); + break; + case LUA_TTABLE: + unpersistTable(info, index); + break; + case LUA_TFUNCTION: + unpersistFunction(info, index); + break; + case LUA_TTHREAD: + unpersistThread(info, index); + break; + case LUA_TPROTO: + unpersistProto(info, index); + break; + case LUA_TUPVAL: + unpersistUpValue(info, index); + break; + case LUA_TUSERDATA: + unpersistUserData(info, index); + break; + case PERMANENT_TYPE: + unpersistPermanent(info, index); + break; + default: + assert(0); + } + + + // >>>>> permTbl indexTbl ...... obj + assert(lua_type(info->luaState, -1) == type || + type == PERMANENT_TYPE || + // Remember, upvalues get a special dispensation, as described in boxUpValue + (lua_type(info->luaState, -1) == LUA_TFUNCTION && type == LUA_TUPVAL)); + + registerObjectInIndexTable(info, index); + // >>>>> permTbl indexTbl ...... obj + } else { + int index = info->readStream->readSint32LE(); + + if (index == 0) { + lua_pushnil(info->luaState); + // >>>>> permTbl indexTbl ...... nil + } else { + // Fetch the object from the indexTbl + + lua_pushlightuserdata(info->luaState, (void *)index); + // >>>>> permTbl indexTbl ...... index + + lua_gettable(info->luaState, 2); + // >>>>> permTbl indexTbl ...... ?obj? + + assert(!lua_isnil(info->luaState, -1)); + } + // >>>>> permTbl indexTbl ...... obj/nil + } + + // >>>>> permTbl indexTbl ...... obj/nil +} + +static void unpersistBoolean(UnSerializationInfo *info) { + // >>>>> permTbl indexTbl ...... + + // Make sure there is enough room on the stack + lua_checkstack(info->luaState, 1); + + int value = info->readStream->readSint32LE(); + + lua_pushboolean(info->luaState, value); + // >>>>> permTbl indexTbl ...... bool +} + +static void unpersistNumber(UnSerializationInfo *info) { + // >>>>> permTbl indexTbl ...... + + // Make sure there is enough room on the stack + lua_checkstack(info->luaState, 1); + + // Read the serialized double + Util::SerializedDouble serializedValue; + serializedValue.significandOne = info->readStream->readUint32LE(); + serializedValue.signAndSignificandTwo = info->readStream->readUint32LE(); + serializedValue.exponent = info->readStream->readSint16LE(); + + lua_Number value = Util::decodeDouble(serializedValue); + + lua_pushnumber(info->luaState, value); + // >>>>> permTbl indexTbl ...... num +} + +static void unpersistString(UnSerializationInfo *info) { + // >>>>> permTbl indexTbl ...... + + // Make sure there is enough room on the stack + lua_checkstack(info->luaState, 1); + + uint32 length = info->readStream->readUint32LE(); + char *string = new char[length]; + + info->readStream->read(string, length); + lua_pushlstring(info->luaState, string, length); + + // >>>>> permTbl indexTbl ...... string + + delete[] string; +} + +static void unserializeSpecialTable(UnSerializationInfo *info, int index) { + // >>>>> permTbl indexTbl ...... + + // Make sure there is enough room on the stack + lua_checkstack(info->luaState, 1); + + unpersist(info); + + // >>>>> permTbl indexTbl ...... spfunc + lua_call(info->luaState, 0, 1); + // >>>>> permTbl indexTbl ...... tbl +} + +static void unserializeLiteralTable(UnSerializationInfo *info, int index) { + // >>>>> permTbl indexTbl ...... + + // Make sure there is enough room on the stack + lua_checkstack(info->luaState, 3); + + // Preregister table for handling of cycles + lua_newtable(info->luaState); + + // >>>>> permTbl indexTbl ...... tbl + registerObjectInIndexTable(info, index); + // >>>>> permTbl indexTbl ...... tbl + + // Unserialize metatable + unpersist(info); + // >>>>> permTbl indexTbl ...... tbl ?metaTbl/nil? + + if (lua_istable(info->luaState, -1)) { + // >>>>> permTbl indexTbl ...... tbl metaTbl + lua_setmetatable(info->luaState, -2); + // >>>>> permTbl indexTbl ...... tbl + } else { + // >>>>> permTbl indexTbl ...... tbl nil + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... tbl + } + // >>>>> permTbl indexTbl ...... tbl + + + while (1) { + // >>>>> permTbl indexTbl ...... tbl + unpersist(info); + // >>>>> permTbl indexTbl ...... tbl key/nil + + // The table serialization is nil terminated + if (lua_isnil(info->luaState, -1)) { + // >>>>> permTbl indexTbl ...... tbl nil + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... tbl + + break; + } + + // >>>>> permTbl indexTbl ...... tbl key + unpersist(info); + // >>>>> permTbl indexTbl ...... tbl value + + lua_rawset(info->luaState, -3); + // >>>>> permTbl indexTbl ...... tbl + } +} + +void unpersistTable(UnSerializationInfo *info, int index) { + // >>>>> permTbl indexTbl ...... + + // Make sure there is enough room on the stack + lua_checkstack(info->luaState, 1); + + int isSpecial = info->readStream->readSint32LE(); + + if (isSpecial) { + unserializeSpecialTable(info, index); + // >>>>> permTbl indexTbl ...... tbl + } else { + unserializeLiteralTable(info, index); + // >>>>> permTbl indexTbl ...... tbl + } +} + +void unpersistFunction(UnSerializationInfo *info, int index) { + // >>>>> permTbl indexTbl ...... + + // Make sure there is enough room on the stack + lua_checkstack(info->luaState, 2); + + byte numUpValues = info->readStream->readByte(); + + LClosure *lclosure = (LClosure *)lua_newLclosure(info->luaState, numUpValues, hvalue(&info->luaState->l_gt)); + pushClosure(info->luaState, (Closure *)lclosure); + // >>>>> permTbl indexTbl ...... func + + // Put *some* proto in the closure, before the GC can find it + lclosure->p = makeFakeProto(info->luaState, numUpValues); + + //Also, we need to temporarily fill the upvalues + lua_pushnil(info->luaState); + // >>>>> permTbl indexTbl ...... func nil + + for (byte i = 0; i < numUpValues; ++i) { + lclosure->upvals[i] = createUpValue(info->luaState, -1); + } + + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... func + + // I can't see offhand how a function would ever get to be self- + // referential, but just in case let's register it early + registerObjectInIndexTable(info, index); + + // Now that it's safe, we can get the real proto + unpersist(info); + // >>>>> permTbl indexTbl ...... func proto + + lclosure->p = gco2p(getObject(info->luaState, -1)->value.gc); + + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... func + + for (byte i = 0; i < numUpValues; ++i) { + // >>>>> permTbl indexTbl ...... func + unpersist(info); + // >>>>> permTbl indexTbl ...... func func2 + + unboxUpValue(info->luaState); + // >>>>> permTbl indexTbl ...... func upValue + lclosure->upvals[i] = gco2uv(getObject(info->luaState, -1)->value.gc); + + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... func + } + + // Finally, the fenv + unpersist(info); + + // >>>>> permTbl indexTbl ...... func ?fenv/nil? + if (!lua_isnil(info->luaState, -1)) { + // >>>>> permTbl indexTbl ...... func fenv + lua_setfenv(info->luaState, -2); + // >>>>> permTbl indexTbl ...... func + } else { + // >>>>> permTbl indexTbl ...... func nil + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... func + } + + // >>>>> permTbl indexTbl ...... func +} + +void unpersistThread(UnSerializationInfo *info, int index) { + // >>>>> permTbl indexTbl ...... + + lua_State *L2; + uint32 stacklimit = 0; + + L2 = lua_newthread(info->luaState); + lua_checkstack(info->luaState, 3); + + // L1: permTbl indexTbl ...... thread + // L2: (empty) + registerObjectInIndexTable(info, index); + + // First, deserialize the object stack + uint32 stackSize = info->readStream->readUint32LE(); + lua_growstack(info->luaState, (int)stackSize); + + // Make sure that the first stack element (a nil, representing + // the imaginary top-level C function) is written to the very, + // very bottom of the stack + L2->top--; + for (uint32 i = 0; i < stackSize; ++i) { + unpersist(info); + // L1: permTbl indexTbl ...... thread obj* + } + + lua_xmove(info->luaState, L2, stackSize); + // L1: permTbl indexTbl ...... thread + // L2: obj* + + // Hereafter, stacks refer to L1 + + + // Now, deserialize the CallInfo stack + + uint32 numFrames = info->readStream->readUint32LE(); + + lua_reallocCallInfo(L2, numFrames * 2); + for (uint32 i = 0; i < numFrames; ++i) { + CallInfo *ci = L2->base_ci + i; + uint32 stackbase = info->readStream->readUint32LE(); + uint32 stackfunc = info->readStream->readUint32LE(); + uint32 stacktop = info->readStream->readUint32LE(); + + ci->nresults = info->readStream->readSint32LE(); + + uint32 savedpc = info->readStream->readUint32LE(); + + if (stacklimit < stacktop) { + stacklimit = stacktop; + } + + ci->base = L2->stack + stackbase; + ci->func = L2->stack + stackfunc; + ci->top = L2->stack + stacktop; + ci->savedpc = (ci != L2->base_ci) ? ci_func(ci)->l.p->code + savedpc : 0; + ci->tailcalls = 0; + + // Update the pointer each time, to keep the GC happy + L2->ci = ci; + } + + // >>>>> permTbl indexTbl ...... thread + // Deserialize the state's other parameters, with the exception of upval stuff + + L2->savedpc = L2->ci->savedpc; + L2->status = info->readStream->readByte(); + uint32 stackbase = info->readStream->readUint32LE(); + uint32 stacktop = info->readStream->readUint32LE(); + + + L2->errfunc = info->readStream->readUint32LE(); + + L2->base = L2->stack + stackbase; + L2->top = L2->stack + stacktop; + + // Finally, "reopen" upvalues. See serializeUpVal() for why we do this + UpVal *uv; + GCObject **nextslot = &L2->openupval; + global_State *g = G(L2); + + while (true) { + unpersist(info); + // >>>>> permTbl indexTbl ...... thread upVal/nil + + // The list is terminated by a nil + if (lua_isnil(info->luaState, -1)) { + // >>>>> permTbl indexTbl ...... thread nil + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... thread + break; + } + + // >>>>> permTbl indexTbl ...... thread boxedUpVal + unboxUpValue(info->luaState); + // >>>>> permTbl indexTbl ...... thread boxedUpVal + + uv = &(getObject(info->luaState, -1)->value.gc->uv); + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... thread + + uint32 stackpos = info->readStream->readUint32LE(); + uv->v = L2->stack + stackpos; + + GCUnlink(info->luaState, (GCObject *)uv); + + uv->marked = luaC_white(g); + *nextslot = (GCObject *)uv; + nextslot = &uv->next; + uv->u.l.prev = &G(L2)->uvhead; + uv->u.l.next = G(L2)->uvhead.u.l.next; + uv->u.l.next->u.l.prev = uv; + G(L2)->uvhead.u.l.next = uv; + lua_assert(uv->u.l.next->u.l.prev == uv && uv->u.l.prev->u.l.next == uv); + } + *nextslot = NULL; + + // The stack must be valid at least to the highest value among the CallInfos + // 'top' and the values up to there must be filled with 'nil' + lua_checkstack(L2, (int)stacklimit); + for (StkId o = L2->top; o <= L2->top + stacklimit; ++o) { + setnilvalue(o); + } +} + +void unpersistProto(UnSerializationInfo *info, int index) { + // >>>>> permTbl indexTbl ...... + + // We have to be careful. The GC expects a lot out of protos. In particular, we need + // to give the function a valid string for its source, and valid code, even before we + // actually read in the real code. + TString *source = lua_newlstr(info->luaState, "", 0); + Proto *p = lua_newproto(info->luaState); + p->source = source; + p->sizecode = 1; + p->code = (Instruction *)lua_reallocv(info->luaState, NULL, 0, 1, sizeof(Instruction)); + p->code[0] = CREATE_ABC(OP_RETURN, 0, 1, 0); + p->maxstacksize = 2; + p->sizek = 0; + p->sizep = 0; + + lua_checkstack(info->luaState, 2); + + pushProto(info->luaState, p); + // >>>>> permTbl indexTbl ...... proto + + // We don't need to register early, since protos can never ever be + // involved in cyclic references + + // Read in constant references + int sizek = info->readStream->readSint32LE(); + lua_reallocvector(info->luaState, p->k, 0, sizek, TValue); + for (int i = 0; i < sizek; ++i) { + // >>>>> permTbl indexTbl ...... proto + unpersist(info); + // >>>>> permTbl indexTbl ...... proto k + + setobj2s(info->luaState, &p->k[i], getObject(info->luaState, -1)); + p->sizek++; + + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... proto + } + // >>>>> permTbl indexTbl ...... proto + + // Read in sub-proto references + + int sizep = info->readStream->readSint32LE(); + lua_reallocvector(info->luaState, p->p, 0, sizep, Proto *); + for (int i = 0; i < sizep; ++i) { + // >>>>> permTbl indexTbl ...... proto + unpersist(info); + // >>>>> permTbl indexTbl ...... proto subproto + + p->p[i] = (Proto *)getObject(info->luaState, -1)->value.gc; + p->sizep++; + + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... proto + } + // >>>>> permTbl indexTbl ...... proto + + + // Read in code + p->sizecode = info->readStream->readSint32LE(); + lua_reallocvector(info->luaState, p->code, 1, p->sizecode, Instruction); + info->readStream->read(p->code, sizeof(Instruction) * p->sizecode); + + + /* Read in upvalue names */ + p->sizeupvalues = info->readStream->readSint32LE(); + if (p->sizeupvalues) { + lua_reallocvector(info->luaState, p->upvalues, 0, p->sizeupvalues, TString *); + for (int i = 0; i < p->sizeupvalues; ++i) { + // >>>>> permTbl indexTbl ...... proto + unpersist(info); + // >>>>> permTbl indexTbl ...... proto str + + p->upvalues[i] = lua_newlstr(info->luaState, lua_tostring(info->luaState, -1), strlen(lua_tostring(info->luaState, -1))); + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... proto + } + } + // >>>>> permTbl indexTbl ...... proto + + // Read in local variable infos + p->sizelocvars = info->readStream->readSint32LE(); + if (p->sizelocvars) { + lua_reallocvector(info->luaState, p->locvars, 0, p->sizelocvars, LocVar); + for (int i = 0; i < p->sizelocvars; ++i) { + // >>>>> permTbl indexTbl ...... proto + unpersist(info); + // >>>>> permTbl indexTbl ...... proto str + + p->locvars[i].varname = lua_newlstr(info->luaState, lua_tostring(info->luaState, -1), strlen(lua_tostring(info->luaState, -1))); + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... proto + + p->locvars[i].startpc = info->readStream->readSint32LE(); + p->locvars[i].endpc = info->readStream->readSint32LE(); + } + } + // >>>>> permTbl indexTbl ...... proto + + // Read in source string + unpersist(info); + // >>>>> permTbl indexTbl ...... proto sourceStr + + p->source = lua_newlstr(info->luaState, lua_tostring(info->luaState, -1), strlen(lua_tostring(info->luaState, -1))); + lua_pop(info->luaState, 1); + // >>>>> permTbl indexTbl ...... proto + + // Read in line numbers + p->sizelineinfo = info->readStream->readSint32LE(); + if (p->sizelineinfo) { + lua_reallocvector(info->luaState, p->lineinfo, 0, p->sizelineinfo, int); + info->readStream->read(p->lineinfo, sizeof(int) * p->sizelineinfo); + } + + + /* Read in linedefined and lastlinedefined */ + p->linedefined = info->readStream->readSint32LE(); + p->lastlinedefined = info->readStream->readSint32LE(); + + // Read in misc values + p->nups = info->readStream->readByte(); + p->numparams = info->readStream->readByte(); + p->is_vararg = info->readStream->readByte(); + p->maxstacksize = info->readStream->readByte(); +} + +void unpersistUpValue(UnSerializationInfo *info, int index) { + // >>>>> permTbl indexTbl ...... + lua_checkstack(info->luaState, 2); + + boxUpValue_start(info->luaState); + // >>>>> permTbl indexTbl ...... func + registerObjectInIndexTable(info, index); + + unpersist(info); + // >>>>> permTbl indexTbl ...... func obj + + boxUpValue_finish(info->luaState); + // >>>>> permTbl indexTbl ...... func +} + +void unpersistUserData(UnSerializationInfo *info, int index) { + // >>>>> permTbl indexTbl ...... + + // Make sure there is enough room on the stack + lua_checkstack(info->luaState, 2); + + int isspecial = info->readStream->readSint32LE(); + if (isspecial) { + unpersist(info); + // >>>>> permTbl indexTbl ...... specialFunc + + lua_call(info->luaState, 0, 1); + // >>>>> permTbl indexTbl ...... udata + } else { + uint32 length = info->readStream->readUint32LE(); + lua_newuserdata(info->luaState, length); + // >>>>> permTbl indexTbl ...... udata + registerObjectInIndexTable(info, index); + + info->readStream->read(lua_touserdata(info->luaState, -1), length); + + unpersist(info); + // >>>>> permTbl indexTbl ...... udata metaTable/nil + + lua_setmetatable(info->luaState, -2); + // >>>>> permTbl indexTbl ...... udata + } + // >>>>> permTbl indexTbl ...... udata +} + +void unpersistPermanent(UnSerializationInfo *info, int index) { + // >>>>> permTbl indexTbl ...... + + // Make sure there is enough room on the stack + lua_checkstack(info->luaState, 2); + + unpersist(info); + // >>>>> permTbl indexTbl ...... permKey + + lua_gettable(info->luaState, 1); + // >>>>> permTbl indexTbl ...... perm +} + +} // End of namespace Lua |