void EHSection::loadFDE(BufReader& reader, uint64_t endPos, CIE* cie)
{
FDE* fde = new FDE;
fde->startAddress = reader.readDwarfPointer(cie->ptrEncoding);
fde->length = reader.readDwarfPointer(cie->ptrEncoding); // if ptrEncoding is relative, then in context of length, it is still just a plain number
if (*cie->augmentationString == 'z')
fde->augmentationDataLength = reader.readLEB128();
else
fde->augmentationDataLength = 0;
if (strchr(cie->augmentationString, 'L') && cie->lsdaEncoding != 0xff) // DW_EH_PE_omit
fde->lsdaPointer = reader.readDwarfPointer(cie->lsdaEncoding);
uint64_t instructionsLength = endPos - reader.pos();
const uint8_t* data = reinterpret_cast<const uint8_t*>(reader.readBlock(instructionsLength));
fde->instructions.assign(data, data+instructionsLength);
cie->fdes.push_back(fde);
}
void EHSection::loadCIE(BufReader& reader, uint64_t endPos, uintptr_t location)
{
CIE* cie = new CIE;
cie->start = reader.pos();
cie->version = reader.read();
cie->augmentationString = reader.readString();
cie->codeAlign = reader.readLEB128();
cie->dataAlign = reader.readLEB128();
if (cie->codeAlign != 1)
{
std::stringstream ss;
ss << "Invalid code alignment: " << int(cie->codeAlign) << std::endl;
delete cie;
throw std::runtime_error(ss.str());
}
if (cie->version == 1)
cie->returnRegister = reader.read();
else if (cie->version == 3)
cie->returnRegister = reader.readLEB128();
else
{
std::stringstream ss;
ss << "Invalid CIE version: " << int(cie->version) << std::endl;
delete cie;
throw std::runtime_error(ss.str());
}
cie->augmentationDataPresent = false;
uint64_t augmentationDataLength, augmentationDataEnd;
cie->lsdaEncoding = cie->ptrEncoding = 0xff;
for (const char* augP = cie->augmentationString; *augP; augP++)
{
switch (*augP)
{
case 'z':
cie->augmentationDataPresent = true;
augmentationDataLength = reader.readULEB128();
augmentationDataEnd = reader.pos() + augmentationDataLength;
break;
case 'L':
cie->lsdaEncoding = reader.read();
break;
case 'R':
cie->ptrEncoding = reader.read();
break;
case 'P':
{
uint8_t persEncoding = reader.read();
cie->personality = reader.readDwarfPointer(persEncoding);
break;
}
case 'S':
break;
default:
{
std::stringstream ss;
ss << "Unsupported character in CIE augmentation string: " << *augP;
delete cie;
throw std::runtime_error(ss.str());
}
}
}
reader.moveTo(augmentationDataEnd);
uint64_t instructionsLength = endPos - reader.pos();
const uint8_t* data = reinterpret_cast<const uint8_t*>(reader.readBlock(instructionsLength));
cie->instructions.assign(data, data+instructionsLength);
m_cies.push_back(cie);
m_ciePositions[location] = cie;
LOG << "Loaded a CIE at " << std::hex << location << std::dec << std::endl;
}