1//===- DWARFDataExtractor.cpp ---------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
10#include "llvm/BinaryFormat/Dwarf.h"
11#include "llvm/DebugInfo/DWARF/DWARFContext.h"
12
13using namespace llvm;
14
15uint64_t DWARFDataExtractor::getRelocatedValue(uint32_t Size, uint64_t *Off,
16                                               uint64_t *SecNdx,
17                                               Error *Err) const {
18  if (SecNdx)
19    *SecNdx = object::SectionedAddress::UndefSection;
20  if (!Section)
21    return getUnsigned(Off, Size, Err);
22  Optional<RelocAddrEntry> E = Obj->find(*Section, *Off);
23  uint64_t A = getUnsigned(Off, Size, Err);
24  if (!E)
25    return A;
26  if (SecNdx)
27    *SecNdx = E->SectionIndex;
28  uint64_t R = E->Resolver(E->Reloc, E->SymbolValue, A);
29  if (E->Reloc2)
30    R = E->Resolver(*E->Reloc2, E->SymbolValue2, R);
31  return R;
32}
33
34Optional<uint64_t>
35DWARFDataExtractor::getEncodedPointer(uint64_t *Offset, uint8_t Encoding,
36                                      uint64_t PCRelOffset) const {
37  if (Encoding == dwarf::DW_EH_PE_omit)
38    return None;
39
40  uint64_t Result = 0;
41  uint64_t OldOffset = *Offset;
42  // First get value
43  switch (Encoding & 0x0F) {
44  case dwarf::DW_EH_PE_absptr:
45    switch (getAddressSize()) {
46    case 2:
47    case 4:
48    case 8:
49      Result = getUnsigned(Offset, getAddressSize());
50      break;
51    default:
52      return None;
53    }
54    break;
55  case dwarf::DW_EH_PE_uleb128:
56    Result = getULEB128(Offset);
57    break;
58  case dwarf::DW_EH_PE_sleb128:
59    Result = getSLEB128(Offset);
60    break;
61  case dwarf::DW_EH_PE_udata2:
62    Result = getUnsigned(Offset, 2);
63    break;
64  case dwarf::DW_EH_PE_udata4:
65    Result = getUnsigned(Offset, 4);
66    break;
67  case dwarf::DW_EH_PE_udata8:
68    Result = getUnsigned(Offset, 8);
69    break;
70  case dwarf::DW_EH_PE_sdata2:
71    Result = getSigned(Offset, 2);
72    break;
73  case dwarf::DW_EH_PE_sdata4:
74    Result = getSigned(Offset, 4);
75    break;
76  case dwarf::DW_EH_PE_sdata8:
77    Result = getSigned(Offset, 8);
78    break;
79  default:
80    return None;
81  }
82  // Then add relative offset, if required
83  switch (Encoding & 0x70) {
84  case dwarf::DW_EH_PE_absptr:
85    // do nothing
86    break;
87  case dwarf::DW_EH_PE_pcrel:
88    Result += PCRelOffset;
89    break;
90  case dwarf::DW_EH_PE_datarel:
91  case dwarf::DW_EH_PE_textrel:
92  case dwarf::DW_EH_PE_funcrel:
93  case dwarf::DW_EH_PE_aligned:
94  default:
95    *Offset = OldOffset;
96    return None;
97  }
98
99  return Result;
100}
101