Optional<DWARFDebugLoc::LocationList>
DWARFDebugLoc::parseOneLocationList(DWARFDataExtractor Data, unsigned *Offset) {
LocationList LL;
LL.Offset = *Offset;
// 2.6.2 Location Lists
// A location list entry consists of:
while (true) {
Entry E;
if (!Data.isValidOffsetForDataOfSize(*Offset, 2 * Data.getAddressSize())) {
llvm::errs() << "Location list overflows the debug_loc section.\n";
return None;
}
// 1. A beginning address offset. ...
E.Begin = Data.getRelocatedAddress(Offset);
// 2. An ending address offset. ...
E.End = Data.getRelocatedAddress(Offset);
// The end of any given location list is marked by an end of list entry,
// which consists of a 0 for the beginning address offset and a 0 for the
// ending address offset.
if (E.Begin == 0 && E.End == 0)
return LL;
if (!Data.isValidOffsetForDataOfSize(*Offset, 2)) {
llvm::errs() << "Location list overflows the debug_loc section.\n";
return None;
}
unsigned Bytes = Data.getU16(Offset);
if (!Data.isValidOffsetForDataOfSize(*Offset, Bytes)) {
llvm::errs() << "Location list overflows the debug_loc section.\n";
return None;
}
// A single location description describing the location of the object...
StringRef str = Data.getData().substr(*Offset, Bytes);
*Offset += Bytes;
E.Loc.reserve(str.size());
std::copy(str.begin(), str.end(), std::back_inserter(E.Loc));
LL.Entries.push_back(std::move(E));
}
}
bool DWARFFormValue::extractValue(const DWARFDataExtractor &Data,
uint32_t *OffsetPtr, DWARFFormParams FP,
const DWARFUnit *CU) {
U = CU;
bool Indirect = false;
bool IsBlock = false;
Value.data = nullptr;
// Read the value for the form into value and follow and DW_FORM_indirect
// instances we run into
do {
Indirect = false;
switch (Form) {
case DW_FORM_addr:
case DW_FORM_ref_addr: {
uint16_t Size =
(Form == DW_FORM_addr) ? FP.AddrSize : FP.getRefAddrByteSize();
Value.uval = Data.getRelocatedValue(Size, OffsetPtr, &Value.SectionIndex);
break;
}
case DW_FORM_exprloc:
case DW_FORM_block:
Value.uval = Data.getULEB128(OffsetPtr);
IsBlock = true;
break;
case DW_FORM_block1:
Value.uval = Data.getU8(OffsetPtr);
IsBlock = true;
break;
case DW_FORM_block2:
Value.uval = Data.getU16(OffsetPtr);
IsBlock = true;
break;
case DW_FORM_block4:
Value.uval = Data.getU32(OffsetPtr);
IsBlock = true;
break;
case DW_FORM_data1:
case DW_FORM_ref1:
case DW_FORM_flag:
case DW_FORM_strx1:
case DW_FORM_addrx1:
Value.uval = Data.getU8(OffsetPtr);
break;
case DW_FORM_data2:
case DW_FORM_ref2:
case DW_FORM_strx2:
case DW_FORM_addrx2:
Value.uval = Data.getU16(OffsetPtr);
break;
case DW_FORM_strx3:
Value.uval = Data.getU24(OffsetPtr);
break;
case DW_FORM_data4:
case DW_FORM_ref4:
case DW_FORM_ref_sup4:
case DW_FORM_strx4:
case DW_FORM_addrx4:
Value.uval = Data.getRelocatedValue(4, OffsetPtr);
break;
case DW_FORM_data8:
case DW_FORM_ref8:
case DW_FORM_ref_sup8:
Value.uval = Data.getU64(OffsetPtr);
break;
case DW_FORM_data16:
// Treat this like a 16-byte block.
Value.uval = 16;
IsBlock = true;
break;
case DW_FORM_sdata:
Value.sval = Data.getSLEB128(OffsetPtr);
break;
case DW_FORM_udata:
case DW_FORM_ref_udata:
Value.uval = Data.getULEB128(OffsetPtr);
break;
case DW_FORM_string:
Value.cstr = Data.getCStr(OffsetPtr);
break;
case DW_FORM_indirect:
Form = static_cast<dwarf::Form>(Data.getULEB128(OffsetPtr));
Indirect = true;
break;
case DW_FORM_strp:
case DW_FORM_sec_offset:
case DW_FORM_GNU_ref_alt:
case DW_FORM_GNU_strp_alt:
case DW_FORM_line_strp:
case DW_FORM_strp_sup: {
Value.uval =
Data.getRelocatedValue(FP.getDwarfOffsetByteSize(), OffsetPtr);
break;
}
case DW_FORM_flag_present:
Value.uval = 1;
break;
case DW_FORM_ref_sig8:
Value.uval = Data.getU64(OffsetPtr);
break;
case DW_FORM_GNU_addr_index:
case DW_FORM_GNU_str_index:
case DW_FORM_strx:
Value.uval = Data.getULEB128(OffsetPtr);
break;
default:
// DWARFFormValue::skipValue() will have caught this and caused all
// DWARF DIEs to fail to be parsed, so this code is not be reachable.
llvm_unreachable("unsupported form");
}
} while (Indirect);
if (IsBlock) {
StringRef Str = Data.getData().substr(*OffsetPtr, Value.uval);
Value.data = nullptr;
if (!Str.empty()) {
Value.data = reinterpret_cast<const uint8_t *>(Str.data());
*OffsetPtr += Value.uval;
}
}
return true;
}
