/* 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. * * $URL$ * $Id$ * */ #include "sci/sci.h" #include "sci/resource.h" #include "sci/util.h" #include "sci/engine/features.h" #include "sci/engine/state.h" #include "sci/engine/kernel.h" #include "sci/engine/script.h" #include "common/util.h" namespace Sci { Script::Script() : SegmentObj(SEG_TYPE_SCRIPT) { _nr = 0; _buf = NULL; _bufSize = 0; _scriptSize = 0; _heapSize = 0; _synonyms = NULL; _heapStart = NULL; _exportTable = NULL; _localsOffset = 0; _localsSegment = 0; _localsBlock = NULL; _localsCount = 0; _markedAsDeleted = false; } Script::~Script() { freeScript(); } void Script::freeScript() { free(_buf); _buf = NULL; _bufSize = 0; _objects.clear(); } void Script::init(int script_nr, ResourceManager *resMan) { Resource *script = resMan->findResource(ResourceId(kResourceTypeScript, script_nr), 0); if (!script) error("Script %d not found\n", script_nr); _localsOffset = 0; _localsBlock = NULL; _localsCount = 0; _markedAsDeleted = false; _nr = script_nr; _buf = 0; _heapStart = 0; _scriptSize = script->size; _bufSize = script->size; _heapSize = 0; _lockers = 1; if (getSciVersion() == SCI_VERSION_0_EARLY) { _bufSize += READ_LE_UINT16(script->data) * 2; } else if (getSciVersion() >= SCI_VERSION_1_1 && getSciVersion() <= SCI_VERSION_2_1) { // In SCI1.1 - SCI2.1, the heap was in a separate space from the script. We append // it to the end of the script, and adjust addressing accordingly. // However, since we address the heap with a 16-bit pointer, the // combined size of the stack and the heap must be 64KB. So far this has // worked for SCI11, SCI2 and SCI21 games. SCI3 games use a different // script format, and theoretically they can exceed the 64KB boundary // using relocation. Resource *heap = resMan->findResource(ResourceId(kResourceTypeHeap, script_nr), 0); _bufSize += heap->size; _heapSize = heap->size; // Ensure that the start of the heap resource can be word-aligned. if (script->size & 2) { _bufSize++; _scriptSize++; } // As mentioned above, the script and the heap together should not exceed 64KB if (script->size + heap->size > 65535) error("Script and heap sizes combined exceed 64K. This means a fundamental " "design bug was made regarding SCI1.1 and newer games.\n" "Please report this error to the ScummVM team"); } else if (getSciVersion() == SCI_VERSION_3) { // Check for scripts over 64KB. These won't work with the current 16-bit address // scheme. We need an overlaying mechanism, or a mechanism to split script parts // in different segments to handle these. For now, simply stop when such a script // is found. // TODO: Remove this once such a mechanism is in place if (script->size > 65535) error("TODO: SCI script %d is over 64KB - it's %d bytes long. This can't " "be handled at the moment, thus stopping", script_nr, script->size); } } void Script::load(ResourceManager *resMan) { Resource *script = resMan->findResource(ResourceId(kResourceTypeScript, _nr), 0); assert(script != 0); _buf = (byte *)malloc(_bufSize); assert(_buf); assert(_bufSize >= script->size); memcpy(_buf, script->data, script->size); // Check scripts for matching signatures and patch those, if found matchSignatureAndPatch(_nr, _buf, script->size); if (getSciVersion() >= SCI_VERSION_1_1 && getSciVersion() <= SCI_VERSION_2_1) { Resource *heap = resMan->findResource(ResourceId(kResourceTypeHeap, _nr), 0); assert(heap != 0); _heapStart = _buf + _scriptSize; assert(_bufSize - _scriptSize <= heap->size); memcpy(_heapStart, heap->data, heap->size); } _exportTable = 0; _numExports = 0; _synonyms = 0; _numSynonyms = 0; if (getSciVersion() <= SCI_VERSION_1_LATE) { _exportTable = (const uint16 *)findBlockSCI0(SCI_OBJ_EXPORTS); if (_exportTable) { _numExports = READ_SCI11ENDIAN_UINT16(_exportTable + 1); _exportTable += 3; // skip header plus 2 bytes (_exportTable is a uint16 pointer) } _synonyms = findBlockSCI0(SCI_OBJ_SYNONYMS); if (_synonyms) { _numSynonyms = READ_SCI11ENDIAN_UINT16(_synonyms + 2) / 4; _synonyms += 4; // skip header } const byte* localsBlock = findBlockSCI0(SCI_OBJ_LOCALVARS); if (localsBlock) { _localsOffset = localsBlock - _buf + 4; _localsCount = (READ_LE_UINT16(_buf + _localsOffset - 2) - 4) >> 1; // half block size } } else if (getSciVersion() >= SCI_VERSION_1_1 && getSciVersion() <= SCI_VERSION_2_1) { if (READ_LE_UINT16(_buf + 1 + 5) > 0) { // does the script have an export table? _exportTable = (const uint16 *)(_buf + 1 + 5 + 2); _numExports = READ_SCI11ENDIAN_UINT16(_exportTable - 1); } _localsOffset = _scriptSize + 4; _localsCount = READ_SCI11ENDIAN_UINT16(_buf + _localsOffset - 2); } else if (getSciVersion() == SCI_VERSION_3) { _localsCount = READ_LE_UINT16(_buf + 12); _exportTable = (const uint16 *)(_buf + 22); _numExports = READ_LE_UINT16(_buf + 20); // SCI3 local variables always start dword-aligned if (_numExports % 2) _localsOffset = 22 + _numExports * 2; else _localsOffset = 24 + _numExports * 2; } if (getSciVersion() == SCI_VERSION_0_EARLY) { // SCI0 early // Old script block. There won't be a localvar block in this case. // Instead, the script starts with a 16 bit int specifying the // number of locals we need; these are then allocated and zeroed. _localsCount = READ_LE_UINT16(_buf); _localsOffset = -_localsCount * 2; // Make sure it's invalid } else { // SCI0 late and newer // Does the script actually have locals? If not, set the locals offset to 0 if (!_localsCount) _localsOffset = 0; if (_localsOffset + _localsCount * 2 + 1 >= (int)_bufSize) { error("Locals extend beyond end of script: offset %04x, count %d vs size %d", _localsOffset, _localsCount, _bufSize); _localsCount = (_bufSize - _localsOffset) >> 1; } } } const byte *Script::getSci3ObjectsPointer() { const byte *ptr = 0; // SCI3 local variables always start dword-aligned if (_numExports % 2) ptr = _buf + 22 + _numExports * 2; else ptr = _buf + 24 + _numExports * 2; // SCI3 object structures always start dword-aligned if (_localsCount % 2) ptr += 2 + _localsCount * 2; else ptr += _localsCount * 2; return ptr; } Object *Script::getObject(uint16 offset) { if (_objects.contains(offset)) return &_objects[offset]; else return 0; } const Object *Script::getObject(uint16 offset) const { if (_objects.contains(offset)) return &_objects[offset]; else return 0; } Object *Script::scriptObjInit(reg_t obj_pos, bool fullObjectInit) { if (getSciVersion() < SCI_VERSION_1_1 && fullObjectInit) obj_pos.offset += 8; // magic offset (SCRIPT_OBJECT_MAGIC_OFFSET) VERIFY(obj_pos.offset < _bufSize, "Attempt to initialize object beyond end of script\n"); VERIFY(obj_pos.offset + kOffsetFunctionArea < (int)_bufSize, "Function area pointer stored beyond end of script\n"); // Get the object at the specified position and init it. This will // automatically "allocate" space for it in the _objects map if necessary. Object *obj = &_objects[obj_pos.offset]; obj->init(_buf, obj_pos, fullObjectInit); return obj; } // This helper function is used by Script::relocateLocal and Object::relocate // Duplicate in segment.cpp and script.cpp static bool relocateBlock(Common::Array &block, int block_location, SegmentId segment, int location, size_t scriptSize) { int rel = location - block_location; if (rel < 0) return false; uint idx = rel >> 1; if (idx >= block.size()) return false; if (rel & 1) { error("Attempt to relocate odd variable #%d.5e (relative to %04x)\n", idx, block_location); return false; } block[idx].segment = segment; // Perform relocation if (getSciVersion() >= SCI_VERSION_1_1 && getSciVersion() <= SCI_VERSION_2_1) block[idx].offset += scriptSize; return true; } int Script::relocateOffsetSci3(uint32 offset) { int relocStart = READ_LE_UINT32(_buf + 8); int relocCount = READ_LE_UINT16(_buf + 18); const byte *seeker = _buf + relocStart; for (int i = 0; i < relocCount; ++i) { if (READ_SCI11ENDIAN_UINT32(seeker) == offset) { // TODO: Find out what UINT16 at (seeker + 8) means return READ_SCI11ENDIAN_UINT16(_buf + offset) + READ_SCI11ENDIAN_UINT32(seeker + 4); } seeker += 10; } return -1; } bool Script::relocateLocal(SegmentId segment, int location) { if (_localsBlock) return relocateBlock(_localsBlock->_locals, _localsOffset, segment, location, _scriptSize); else return false; } void Script::relocateSci0Sci21(reg_t block) { const byte *heap = _buf; uint16 heapSize = (uint16)_bufSize; uint16 heapOffset = 0; if (getSciVersion() >= SCI_VERSION_1_1 && getSciVersion() <= SCI_VERSION_2_1) { heap = _heapStart; heapSize = (uint16)_heapSize; heapOffset = _scriptSize; } VERIFY(block.offset < (uint16)heapSize && READ_SCI11ENDIAN_UINT16(heap + block.offset) * 2 + block.offset < (uint16)heapSize, "Relocation block outside of script\n"); int count = READ_SCI11ENDIAN_UINT16(heap + block.offset); int exportIndex = 0; int pos = 0; for (int i = 0; i < count; i++) { pos = READ_SCI11ENDIAN_UINT16(heap + block.offset + 2 + (exportIndex * 2)) + heapOffset; // This occurs in SCI01/SCI1 games where usually one export value is // zero. It seems that in this situation, we should skip the export and // move to the next one, though the total count of valid exports remains // the same if (!pos) { exportIndex++; pos = READ_SCI11ENDIAN_UINT16(heap + block.offset + 2 + (exportIndex * 2)) + heapOffset; if (!pos) error("Script::relocate(): Consecutive zero exports found"); } // In SCI0-SCI1, script local variables, objects and code are relocated. // We only relocate locals and objects here, and ignore relocation of // code blocks. In SCI1.1 and newer versions, only locals and objects // are relocated. if (!relocateLocal(block.segment, pos)) { // Not a local? It's probably an object or code block. If it's an // object, relocate it. const ObjMap::iterator end = _objects.end(); for (ObjMap::iterator it = _objects.begin(); it != end; ++it) if (it->_value.relocateSci0Sci21(block.segment, pos, _scriptSize)) break; } exportIndex++; } } void Script::relocateSci3(reg_t block) { const byte *relocStart = _buf + READ_SCI11ENDIAN_UINT32(_buf + 8); //int count = _bufSize - READ_SCI11ENDIAN_UINT32(_buf + 8); ObjMap::iterator it; for (it = _objects.begin(); it != _objects.end(); ++it) { unsigned int ofs = it->_value.getPos().offset; unsigned int size = READ_SCI11ENDIAN_UINT16(_buf + ofs + 2); const byte *seeker = relocStart; while (READ_SCI11ENDIAN_UINT32(seeker) < ofs + size && seeker < _buf + _bufSize) { while (READ_SCI11ENDIAN_UINT32(seeker) < ofs) seeker += 10; // TODO: Find out what UINT16 at (seeker + 8) means it->_value.relocateSci3(block.segment, READ_SCI11ENDIAN_UINT32(seeker), READ_SCI11ENDIAN_UINT32(seeker + 4), _scriptSize); seeker += 10; } } } void Script::incrementLockers() { _lockers++; } void Script::decrementLockers() { if (_lockers > 0) _lockers--; } int Script::getLockers() const { return _lockers; } void Script::setLockers(int lockers) { _lockers = lockers; } uint16 Script::validateExportFunc(int pubfunct, bool relocate) { bool exportsAreWide = (g_sci->_features->detectLofsType() == SCI_VERSION_1_MIDDLE); if (_numExports <= pubfunct) { error("validateExportFunc(): pubfunct is invalid"); return 0; } if (exportsAreWide) pubfunct *= 2; uint16 offset; if (getSciVersion() != SCI_VERSION_3 || !relocate) { offset = READ_SCI11ENDIAN_UINT16(_exportTable + pubfunct); } else { offset = relocateOffsetSci3(pubfunct * 2 + 22); } VERIFY(offset < _bufSize, "invalid export function pointer"); // Check if the offset found points to a second export table (e.g. script 912 // in Camelot and script 306 in KQ4). Such offsets are usually small (i.e. < 10), // thus easily distinguished from actual code offsets. // This only makes sense for SCI0-SCI1, as the export table in SCI1.1+ games // is located at a specific address, thus findBlockSCI0() won't work. // Fixes bugs #3039785 and #3037595. if (offset < 10 && getSciVersion() <= SCI_VERSION_1_LATE) { const uint16 *secondExportTable = (const uint16 *)findBlockSCI0(SCI_OBJ_EXPORTS, 0); if (secondExportTable) { secondExportTable += 3; // skip header plus 2 bytes (secondExportTable is a uint16 pointer) offset = READ_SCI11ENDIAN_UINT16(secondExportTable + pubfunct); VERIFY(offset < _bufSize, "invalid export function pointer"); } } return offset; } byte *Script::findBlockSCI0(int type, int startBlockIndex) { byte *buf = _buf; bool oldScriptHeader = (getSciVersion() == SCI_VERSION_0_EARLY); int blockIndex = 0; if (oldScriptHeader) buf += 2; do { int blockType = READ_LE_UINT16(buf); if (blockType == 0) break; if (blockType == type && blockIndex > startBlockIndex) return buf; int blockSize = READ_LE_UINT16(buf + 2); assert(blockSize > 0); buf += blockSize; blockIndex++; } while (1); return NULL; } // memory operations void Script::mcpyInOut(int dst, const void *src, size_t n) { if (_buf) { assert(dst + n <= _bufSize); memcpy(_buf + dst, src, n); } } bool Script::isValidOffset(uint16 offset) const { return offset < _bufSize; } SegmentRef Script::dereference(reg_t pointer) { if (pointer.offset > _bufSize) { error("Script::dereference(): Attempt to dereference invalid pointer %04x:%04x into script segment (script size=%d)", PRINT_REG(pointer), (uint)_bufSize); return SegmentRef(); } SegmentRef ret; ret.isRaw = true; ret.maxSize = _bufSize - pointer.offset; ret.raw = _buf + pointer.offset; return ret; } void Script::initialiseLocals(SegManager *segMan) { LocalVariables *locals = segMan->allocLocalsSegment(this); if (locals) { if (getSciVersion() > SCI_VERSION_0_EARLY) { const byte *base = (const byte *)(_buf + getLocalsOffset()); for (uint16 i = 0; i < getLocalsCount(); i++) locals->_locals[i] = make_reg(0, READ_SCI11ENDIAN_UINT16(base + i * 2)); } else { // In SCI0 early, locals are set at run time, thus zero them all here for (uint16 i = 0; i < getLocalsCount(); i++) locals->_locals[i] = NULL_REG; } } } void Script::initialiseClasses(SegManager *segMan) { const byte *seeker = 0; uint16 mult = 0; if (getSciVersion() <= SCI_VERSION_1_LATE) { seeker = findBlockSCI0(SCI_OBJ_CLASS); mult = 1; } else if (getSciVersion() >= SCI_VERSION_1_1 && getSciVersion() <= SCI_VERSION_2_1) { seeker = _heapStart + 4 + READ_SCI11ENDIAN_UINT16(_heapStart + 2) * 2; mult = 2; } else if (getSciVersion() == SCI_VERSION_3) { seeker = getSci3ObjectsPointer(); mult = 1; } if (!seeker) return; uint16 marker; bool isClass = false; uint16 classpos; int16 species = 0; while (true) { // In SCI0-SCI1, this is the segment type. In SCI11, it's a marker (0x1234) marker = READ_SCI11ENDIAN_UINT16(seeker); classpos = seeker - _buf; if (getSciVersion() <= SCI_VERSION_1_LATE && !marker) break; if (getSciVersion() >= SCI_VERSION_1_1 && marker != 0x1234) break; if (getSciVersion() <= SCI_VERSION_1_LATE) { isClass = (marker == SCI_OBJ_CLASS); if (isClass) species = READ_SCI11ENDIAN_UINT16(seeker + 12); classpos += 12; } else if (getSciVersion() >= SCI_VERSION_1_1 && getSciVersion() <= SCI_VERSION_2_1) { isClass = (READ_SCI11ENDIAN_UINT16(seeker + 14) & kInfoFlagClass); // -info- selector species = READ_SCI11ENDIAN_UINT16(seeker + 10); } else if (getSciVersion() == SCI_VERSION_3) { isClass = (READ_SCI11ENDIAN_UINT16(seeker + 10) & kInfoFlagClass); species = READ_SCI11ENDIAN_UINT16(seeker + 4); } if (isClass) { // WORKAROUNDs for off-by-one script errors if (species == (int)segMan->classTableSize()) { if (g_sci->getGameId() == GID_LSL2 && g_sci->isDemo()) segMan->resizeClassTable(species + 1); else if (g_sci->getGameId() == GID_LSL3 && !g_sci->isDemo() && _nr == 500) segMan->resizeClassTable(species + 1); else if (g_sci->getGameId() == GID_SQ3 && !g_sci->isDemo() && _nr == 93) segMan->resizeClassTable(species + 1); else if (g_sci->getGameId() == GID_SQ3 && !g_sci->isDemo() && _nr == 99) segMan->resizeClassTable(species + 1); } if (species < 0 || species >= (int)segMan->classTableSize()) error("Invalid species %d(0x%x) unknown max %d(0x%x) while instantiating script %d\n", species, species, segMan->classTableSize(), segMan->classTableSize(), _nr); SegmentId segmentId = segMan->getScriptSegment(_nr); segMan->setClassOffset(species, make_reg(segmentId, classpos)); } seeker += READ_SCI11ENDIAN_UINT16(seeker + 2) * mult; } } void Script::initialiseObjectsSci0(SegManager *segMan, SegmentId segmentId) { bool oldScriptHeader = (getSciVersion() == SCI_VERSION_0_EARLY); // We need to make two passes, as the objects in the script might be in the // wrong order (e.g. in the demo of Iceman) - refer to bug #3034713 for (int pass = 1; pass <= 2; pass++) { const byte *seeker = _buf + (oldScriptHeader ? 2 : 0); do { uint16 objType = READ_SCI11ENDIAN_UINT16(seeker); if (!objType) break; switch (objType) { case SCI_OBJ_OBJECT: case SCI_OBJ_CLASS: { reg_t addr = make_reg(segmentId, seeker - _buf + 4); Object *obj = scriptObjInit(addr); obj->initSpecies(segMan, addr); if (pass == 2) { if (!obj->initBaseObject(segMan, addr)) { error("Failed to locate base object for object at %04X:%04X", PRINT_REG(addr)); //scriptObjRemove(addr); } } } break; default: break; } seeker += READ_SCI11ENDIAN_UINT16(seeker + 2); } while ((uint32)(seeker - _buf) < getScriptSize() - 2); } byte *relocationBlock = findBlockSCI0(SCI_OBJ_POINTERS); if (relocationBlock) relocateSci0Sci21(make_reg(segmentId, relocationBlock - getBuf() + 4)); } void Script::initialiseObjectsSci11(SegManager *segMan, SegmentId segmentId) { const byte *seeker = _heapStart + 4 + READ_SCI11ENDIAN_UINT16(_heapStart + 2) * 2; while (READ_SCI11ENDIAN_UINT16(seeker) == SCRIPT_OBJECT_MAGIC_NUMBER) { reg_t reg = make_reg(segmentId, seeker - _buf); Object *obj = scriptObjInit(reg); // Copy base from species class, as we need its selector IDs obj->setSuperClassSelector( segMan->getClassAddress(obj->getSuperClassSelector().offset, SCRIPT_GET_LOCK, NULL_REG)); // If object is instance, get -propDict- from class and set it for this // object. This is needed for ::isMemberOf() to work. // Example test case - room 381 of sq4cd - if isMemberOf() doesn't work, // talk-clicks on the robot will act like clicking on ego if (!obj->isClass()) { reg_t classObject = obj->getSuperClassSelector(); const Object *classObj = segMan->getObject(classObject); obj->setPropDictSelector(classObj->getPropDictSelector()); } // Set the -classScript- selector to the script number. // FIXME: As this selector is filled in at run-time, it is likely // that it is supposed to hold a pointer. The Obj::isKindOf method // uses this selector together with -propDict- to compare classes. // For the purpose of Obj::isKindOf, using the script number appears // to be sufficient. obj->setClassScriptSelector(make_reg(0, _nr)); seeker += READ_SCI11ENDIAN_UINT16(seeker + 2) * 2; } relocateSci0Sci21(make_reg(segmentId, READ_SCI11ENDIAN_UINT16(_heapStart))); } void Script::initialiseObjectsSci3(SegManager *segMan, SegmentId segmentId) { const byte *seeker = getSci3ObjectsPointer(); while (READ_SCI11ENDIAN_UINT16(seeker) == SCRIPT_OBJECT_MAGIC_NUMBER) { reg_t reg = make_reg(segmentId, seeker - _buf); Object *obj = scriptObjInit(reg); obj->setSuperClassSelector(segMan->getClassAddress(obj->getSuperClassSelector().offset, SCRIPT_GET_LOCK, NULL_REG)); seeker += READ_SCI11ENDIAN_UINT16(seeker + 2); } relocateSci3(make_reg(segmentId, 0)); } void Script::initialiseObjects(SegManager *segMan, SegmentId segmentId) { if (getSciVersion() <= SCI_VERSION_1_LATE) initialiseObjectsSci0(segMan, segmentId); else if (getSciVersion() >= SCI_VERSION_1_1 && getSciVersion() <= SCI_VERSION_2_1) initialiseObjectsSci11(segMan, segmentId); else if (getSciVersion() == SCI_VERSION_3) initialiseObjectsSci3(segMan, segmentId); } reg_t Script::findCanonicAddress(SegManager *segMan, reg_t addr) const { addr.offset = 0; return addr; } void Script::freeAtAddress(SegManager *segMan, reg_t addr) { /* debugC(2, kDebugLevelGC, "[GC] Freeing script %04x:%04x", PRINT_REG(addr)); if (_localsSegment) debugC(2, kDebugLevelGC, "[GC] Freeing locals %04x:0000", _localsSegment); */ if (_markedAsDeleted) segMan->deallocateScript(_nr); } Common::Array Script::listAllDeallocatable(SegmentId segId) const { const reg_t r = make_reg(segId, 0); return Common::Array(&r, 1); } Common::Array Script::listAllOutgoingReferences(reg_t addr) const { Common::Array tmp; if (addr.offset <= _bufSize && addr.offset >= -SCRIPT_OBJECT_MAGIC_OFFSET && RAW_IS_OBJECT(_buf + addr.offset)) { const Object *obj = getObject(addr.offset); if (obj) { // Note all local variables, if we have a local variable environment if (_localsSegment) tmp.push_back(make_reg(_localsSegment, 0)); for (uint i = 0; i < obj->getVarCount(); i++) tmp.push_back(obj->getVariable(i)); } else { error("Request for outgoing script-object reference at %04x:%04x failed", PRINT_REG(addr)); } } else { /* warning("Unexpected request for outgoing script-object references at %04x:%04x", PRINT_REG(addr));*/ /* Happens e.g. when we're looking into strings */ } return tmp; } Common::Array Script::listObjectReferences() const { Common::Array tmp; // Locals, if present if (_localsSegment) tmp.push_back(make_reg(_localsSegment, 0)); // All objects (may be classes, may be indirectly reachable) ObjMap::iterator it; const ObjMap::iterator end = _objects.end(); for (it = _objects.begin(); it != end; ++it) { tmp.push_back(it->_value.getPos()); } return tmp; } } // End of namespace Sci