llvm-project/llvm/lib/DebugInfo/DWARF/DWARFDataExtractor.cpp

97 lines
2.5 KiB
C++

//===- DWARFDataExtractor.cpp ---------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
using namespace llvm;
uint64_t DWARFDataExtractor::getRelocatedValue(uint32_t Size, uint32_t *Off,
uint64_t *SecNdx) const {
if (SecNdx)
*SecNdx = -1ULL;
if (!Section)
return getUnsigned(Off, Size);
Optional<RelocAddrEntry> Rel = Obj->find(*Section, *Off);
if (!Rel)
return getUnsigned(Off, Size);
if (SecNdx)
*SecNdx = Rel->SectionIndex;
return getUnsigned(Off, Size) + Rel->Value;
}
Optional<uint64_t>
DWARFDataExtractor::getEncodedPointer(uint32_t *Offset, uint8_t Encoding,
uint64_t PCRelOffset) const {
if (Encoding == dwarf::DW_EH_PE_omit)
return None;
uint64_t Result = 0;
uint32_t OldOffset = *Offset;
// First get value
switch (Encoding & 0x0F) {
case dwarf::DW_EH_PE_absptr:
switch (getAddressSize()) {
case 2:
case 4:
case 8:
Result = getUnsigned(Offset, getAddressSize());
break;
default:
return None;
}
break;
case dwarf::DW_EH_PE_uleb128:
Result = getULEB128(Offset);
break;
case dwarf::DW_EH_PE_sleb128:
Result = getSLEB128(Offset);
break;
case dwarf::DW_EH_PE_udata2:
Result = getUnsigned(Offset, 2);
break;
case dwarf::DW_EH_PE_udata4:
Result = getUnsigned(Offset, 4);
break;
case dwarf::DW_EH_PE_udata8:
Result = getUnsigned(Offset, 8);
break;
case dwarf::DW_EH_PE_sdata2:
Result = getSigned(Offset, 2);
break;
case dwarf::DW_EH_PE_sdata4:
Result = getSigned(Offset, 4);
break;
case dwarf::DW_EH_PE_sdata8:
Result = getSigned(Offset, 8);
break;
default:
return None;
}
// Then add relative offset, if required
switch (Encoding & 0x70) {
case dwarf::DW_EH_PE_absptr:
// do nothing
break;
case dwarf::DW_EH_PE_pcrel:
Result += PCRelOffset;
break;
case dwarf::DW_EH_PE_datarel:
case dwarf::DW_EH_PE_textrel:
case dwarf::DW_EH_PE_funcrel:
case dwarf::DW_EH_PE_aligned:
default:
*Offset = OldOffset;
return None;
}
return Result;
}