yetangitu/ghidra
1
0
Fork 0
mirror of https://github.com/NationalSecurityAgency/ghidra.git synced 2025-10-03 17:59:46 +02:00
Code Issues Releases Wiki Activity

GP-1922 Integer size suffix

Browse source
This commit is contained in:
caheckman 2022-04-13 19:02:24 -04:00
parent d7f9cdfe5c
commit fb3366a4e2
15 changed files with 178 additions and 66 deletions
Download patch file Download diff file Expand all files Collapse all files

74
Ghidra/Features/Decompiler/src/decompile/cpp/cast.cc
View file

@ -25,6 +25,80 @@ void CastStrategy::setTypeFactory(TypeFactory *t)
promoteSize = tlst->getSizeOfInt();
}
/// Many languages can mark an integer constant as explicitly \e unsigned. When
/// the decompiler is deciding on \e cast operations, this is one of the checks
/// it performs. This method checks if the indicated input is an
/// integer constant that needs to be coerced (as a source token) into being unsigned.
/// If this is \b true, the input Varnode is marked for printing as explicitly \e unsigned.
/// \param op is the PcodeOp taking the value as input
/// \param slot is the input slot of the value
/// \return \b true if the Varnode gets marked for printing
bool CastStrategy::markExplicitUnsigned(PcodeOp *op,int4 slot) const
{
TypeOp *opcode = op->getOpcode();
if (!opcode->inheritsSign()) return false;
bool inheritsFirstParamOnly = opcode->inheritsSignFirstParamOnly();
if ((slot==1) && inheritsFirstParamOnly) return false;
Varnode *vn = op->getIn(slot);
if (!vn->isConstant()) return false;
Datatype *dt = vn->getHighTypeReadFacing(op);
type_metatype meta = dt->getMetatype();
if ((meta != TYPE_UINT)&&(meta != TYPE_UNKNOWN)) return false;
if (dt->isCharPrint()) return false;
if (dt->isEnumType()) return false;
if ((op->numInput() == 2) && !inheritsFirstParamOnly) {
Varnode *firstvn = op->getIn(1-slot);
meta = firstvn->getHighTypeReadFacing(op)->getMetatype();
if ((meta == TYPE_UINT)||(meta == TYPE_UNKNOWN))
return false; // Other side of the operation will force the unsigned
}
// Check if type is going to get forced anyway
Varnode *outvn = op->getOut();
if (outvn != (Varnode *)0) {
if (outvn->isExplicit()) return false;
PcodeOp *lone = outvn->loneDescend();
if (lone != (PcodeOp *)0) {
if (!lone->getOpcode()->inheritsSign()) return false;
}
}
vn->setUnsignedPrint();
return true;
}
/// This method checks if the indicated input is an integer constant that needs to be coerced
/// (as a source token) into a data-type that is larger than the base integer. If this is \b true,
/// the input Varnode is marked for printing as explicitly a larger integer (typically \e long).
/// \param op is the PcodeOp taking the value as input
/// \param slot is the input slot of the value
/// \return \b true if the Varnode gets marked for printing
bool CastStrategy::markExplicitLongSize(PcodeOp *op,int4 slot) const
{
if (!op->getOpcode()->isShiftOp()) return false;
if (slot != 0) return false;
Varnode *vn = op->getIn(slot);
if (!vn->isConstant()) return false;
if (vn->getSize() <= promoteSize) return false;
Datatype *dt = vn->getHigh()->getType();
type_metatype meta = dt->getMetatype();
if ((meta != TYPE_UINT)&&(meta != TYPE_INT)&&(meta != TYPE_UNKNOWN)) return false;
uintb off = vn->getOffset();
if (meta == TYPE_INT && signbit_negative(off, vn->getSize())) {
off = uintb_negate(off, vn->getSize());
int4 bit = mostsigbit_set(off);
if (bit >= promoteSize * 8 - 1) return false;
}
else {
int4 bit = mostsigbit_set(off);
if (bit >= promoteSize * 8) return false; // If integer is big enough, it naturally becomes a long
}
vn->setLongPrint();
return true;
}
bool CastStrategyC::checkIntPromotionForCompare(const PcodeOp *op,int4 slot) const
{