/*!
* Whether a location set is a pointer type or not
*/
bool ObjTypeInfo::isNonPtrFieldObj(const LocationSet& ls)
{
if (isHeap() || isStaticObj())
return false;
llvm::Type* ety = getLLVMType();
while (const ArrayType *AT= dyn_cast<ArrayType>(ety)) {
ety = AT->getElementType();
}
if (isa<StructType>(ety) || isa<ArrayType>(ety)) {
bool hasIntersection = false;
const vector<FieldInfo> &infovec = SymbolTableInfo::Symbolnfo()->getFlattenFieldInfoVec(ety);
vector<FieldInfo>::const_iterator it = infovec.begin();
vector<FieldInfo>::const_iterator eit = infovec.end();
for (; it != eit; ++it) {
const FieldInfo& fieldLS = *it;
if (ls.intersects(LocationSet(fieldLS))) {
hasIntersection = true;
if (fieldLS.getFlattenElemTy()->isPointerTy())
return false;
}
}
assert(hasIntersection && "cannot find field of specified offset");
return true;
}
else {
if (isStaticObj() || isHeap()) {
// TODO: Objects which cannot find proper field for a certain offset including
// arguments in main(), static objects allocated before main and heap
// objects. Right now they're considered to have infinite fields and we
// treat each field as pointers conservatively.
// Try to model static and heap objects more accurately in the future.
return false;
}
else {
// TODO: Using new memory model (locMM) may create objects with spurious offset
// as we simply return new offset by mod operation without checking its
// correctness in LocSymTableInfo::getModulusOffset(). So the following
// assertion may fail. Try to refine the new memory model.
assert(ls.getOffset() == 0 && "cannot get a field from a non-struct type");
return (hasPtrObj() == false);
}
}
}
/*!
* Get modulus offset given the type information
*/
LocationSet SymbolTableInfo::getModulusOffset(ObjTypeInfo* tyInfo, const LocationSet& ls) {
/// if the offset is negative, it's possible that we're looking for an obj node out of range
/// of current struct. Make the offset positive so we can still get a node within current
/// struct to represent this obj.
Size_t offset = ls.getOffset();
if(offset < 0) {
wrnMsg("try to create a gep node with negative offset.");
offset = abs(offset);
}
u32_t maxOffset = tyInfo->getMaxFieldOffsetLimit();
if (maxOffset != 0)
offset = offset % maxOffset;
else
offset = 0;
return LocationSet(offset);
}
