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|
/* 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);
_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) {
// In SCI11, 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");
}
}
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) {
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_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 {
_exportTable = (const uint16 *)findBlock(SCI_OBJ_EXPORTS);
if (_exportTable) {
_numExports = READ_SCI11ENDIAN_UINT16(_exportTable + 1);
_exportTable += 3; // skip header plus 2 bytes (_exportTable is a uint16 pointer)
}
_synonyms = findBlock(SCI_OBJ_SYNONYMS);
if (_synonyms) {
_numSynonyms = READ_SCI11ENDIAN_UINT16(_synonyms + 2) / 4;
_synonyms += 4; // skip header
}
const byte* localsBlock = findBlock(SCI_OBJ_LOCALVARS);
if (localsBlock) {
_localsOffset = localsBlock - _buf + 4;
_localsCount = (READ_LE_UINT16(_buf + _localsOffset - 2) - 4) >> 1; // half block size
}
}
if (getSciVersion() > SCI_VERSION_0_EARLY) {
// 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;
}
} else {
// 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
}
}
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;
}
void Script::scriptObjRemove(reg_t obj_pos) {
if (getSciVersion() < SCI_VERSION_1_1)
obj_pos.offset += 8;
_objects.erase(obj_pos.toUint16());
}
// This helper function is used by Script::relocateLocal and Object::relocate
// Duplicate in segment.cpp and script.cpp
static bool relocateBlock(Common::Array<reg_t> &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)
block[idx].offset += scriptSize;
return true;
}
bool Script::relocateLocal(SegmentId segment, int location) {
if (_localsBlock)
return relocateBlock(_localsBlock->_locals, _localsOffset, segment, location, _scriptSize);
else
return false;
}
void Script::relocate(reg_t block) {
const byte *heap = _buf;
uint16 heapSize = (uint16)_bufSize;
uint16 heapOffset = 0;
if (getSciVersion() >= SCI_VERSION_1_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.relocate(block.segment, pos, _scriptSize))
break;
}
exportIndex++;
}
}
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 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 = READ_SCI11ENDIAN_UINT16(_exportTable + pubfunct);
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 findBlock() won't work.
// Fixes bugs #3039785 and #3037595.
if (offset < 10 && getSciVersion() <= SCI_VERSION_1_LATE) {
const uint16 *secondExportTable = (const uint16 *)findBlock(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::findBlock(int type, int skipBlockIndex) {
byte *buf = _buf;
bool oldScriptHeader = (getSciVersion() == SCI_VERSION_0_EARLY);
int blockIndex = 0;
if (oldScriptHeader)
buf += 2;
do {
int seekerType = READ_LE_UINT16(buf);
if (seekerType == 0)
break;
if (seekerType == type && blockIndex != skipBlockIndex)
return buf;
int seekerSize = READ_LE_UINT16(buf + 2);
assert(seekerSize > 0);
buf += seekerSize;
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_1) {
seeker = _heapStart + 4 + READ_SCI11ENDIAN_UINT16(_heapStart + 2) * 2;
mult = 2;
} else {
seeker = findBlock(SCI_OBJ_CLASS);
mult = 1;
}
if (!seeker)
return;
uint16 marker;
bool isClass;
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 (!marker)
break;
if (getSciVersion() >= SCI_VERSION_1_1) {
isClass = (READ_SCI11ENDIAN_UINT16(seeker + 14) & kInfoFlagClass); // -info- selector
species = READ_SCI11ENDIAN_UINT16(seeker + 10);
} else {
isClass = (marker == SCI_OBJ_CLASS);
if (isClass)
species = READ_SCI11ENDIAN_UINT16(seeker + 12);
classpos += 12;
}
if (isClass) {
// WORKAROUNDs for off-by-one script errors
if (g_sci->getGameId() == GID_LSL2 && g_sci->isDemo() && species == (int)segMan->classTableSize())
segMan->resizeClassTable(segMan->classTableSize() + 1);
if (g_sci->getGameId() == GID_LSL3 && !g_sci->isDemo() && _nr == 500 && species == (int)segMan->classTableSize())
segMan->resizeClassTable(segMan->classTableSize() + 1);
if (g_sci->getGameId() == GID_SQ3 && !g_sci->isDemo() && _nr == 93 && species == (int)segMan->classTableSize())
segMan->resizeClassTable(segMan->classTableSize() + 1);
if (g_sci->getGameId() == GID_SQ3 && !g_sci->isDemo() && _nr == 99 && species == (int)segMan->classTableSize())
segMan->resizeClassTable(segMan->classTableSize() + 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);
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 (!obj->initBaseObject(segMan, addr)) {
if (_nr == 202 && g_sci->getGameId() == GID_KQ5) {
// WORKAROUND: Script 202 of KQ5 French and German
// (perhaps Spanish too?) has an invalid object.
// This is non-fatal. Refer to bug #3035396.
} else {
error("Failed to locate base object for object at %04X:%04X; skipping", PRINT_REG(addr));
}
scriptObjRemove(addr);
}
}
break;
default:
break;
}
seeker += READ_SCI11ENDIAN_UINT16(seeker + 2);
} while ((uint32)(seeker - _buf) < getScriptSize() - 2);
byte *relocationBlock = findBlock(SCI_OBJ_POINTERS);
if (relocationBlock)
relocate(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 testcase - 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;
}
relocate(make_reg(segmentId, READ_SCI11ENDIAN_UINT16(_heapStart)));
}
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<reg_t> Script::listAllDeallocatable(SegmentId segId) const {
const reg_t r = make_reg(segId, 0);
return Common::Array<reg_t>(&r, 1);
}
Common::Array<reg_t> Script::listAllOutgoingReferences(reg_t addr) const {
Common::Array<reg_t> 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<reg_t> Script::listObjectReferences() const {
Common::Array<reg_t> 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
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