LLVM  10.0.0svn
DWARFVisitor.cpp
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1 //===--- DWARFVisitor.cpp ---------------------------------------*- C++ -*-===//
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 //===----------------------------------------------------------------------===//
10 
11 #include "DWARFVisitor.h"
12 #include "llvm/ObjectYAML/DWARFYAML.h"
13 
14 using namespace llvm;
15 
16 template <typename T>
17 void DWARFYAML::VisitorImpl<T>::onVariableSizeValue(uint64_t U, unsigned Size) {
18  switch (Size) {
19  case 8:
20  onValue((uint64_t)U);
21  break;
22  case 4:
23  onValue((uint32_t)U);
24  break;
25  case 2:
26  onValue((uint16_t)U);
27  break;
28  case 1:
29  onValue((uint8_t)U);
30  break;
31  default:
32  llvm_unreachable("Invalid integer write size.");
33  }
34 }
35 
36 static unsigned getOffsetSize(const DWARFYAML::Unit &Unit) {
37  return Unit.Length.isDWARF64() ? 8 : 4;
38 }
39 
40 static unsigned getRefSize(const DWARFYAML::Unit &Unit) {
41  if (Unit.Version == 2)
42  return Unit.AddrSize;
43  return getOffsetSize(Unit);
44 }
45 
46 template <typename T> void DWARFYAML::VisitorImpl<T>::traverseDebugInfo() {
47  for (auto &Unit : DebugInfo.CompileUnits) {
48  onStartCompileUnit(Unit);
49  auto FirstAbbrevCode = Unit.Entries[0].AbbrCode;
50 
51  for (auto &Entry : Unit.Entries) {
52  onStartDIE(Unit, Entry);
53  if (Entry.AbbrCode == 0u)
54  continue;
55  auto &Abbrev = DebugInfo.AbbrevDecls[Entry.AbbrCode - FirstAbbrevCode];
56  auto FormVal = Entry.Values.begin();
57  auto AbbrForm = Abbrev.Attributes.begin();
58  for (;
59  FormVal != Entry.Values.end() && AbbrForm != Abbrev.Attributes.end();
60  ++FormVal, ++AbbrForm) {
61  onForm(*AbbrForm, *FormVal);
62  dwarf::Form Form = AbbrForm->Form;
63  bool Indirect;
64  do {
65  Indirect = false;
66  switch (Form) {
67  case dwarf::DW_FORM_addr:
68  onVariableSizeValue(FormVal->Value, Unit.AddrSize);
69  break;
70  case dwarf::DW_FORM_ref_addr:
71  onVariableSizeValue(FormVal->Value, getRefSize(Unit));
72  break;
73  case dwarf::DW_FORM_exprloc:
74  case dwarf::DW_FORM_block:
75  onValue((uint64_t)FormVal->BlockData.size(), true);
76  onValue(
77  MemoryBufferRef(StringRef((const char *)&FormVal->BlockData[0],
78  FormVal->BlockData.size()),
79  ""));
80  break;
81  case dwarf::DW_FORM_block1: {
82  auto writeSize = FormVal->BlockData.size();
83  onValue((uint8_t)writeSize);
84  onValue(
85  MemoryBufferRef(StringRef((const char *)&FormVal->BlockData[0],
86  FormVal->BlockData.size()),
87  ""));
88  break;
89  }
90  case dwarf::DW_FORM_block2: {
91  auto writeSize = FormVal->BlockData.size();
92  onValue((uint16_t)writeSize);
93  onValue(
94  MemoryBufferRef(StringRef((const char *)&FormVal->BlockData[0],
95  FormVal->BlockData.size()),
96  ""));
97  break;
98  }
99  case dwarf::DW_FORM_block4: {
100  auto writeSize = FormVal->BlockData.size();
101  onValue((uint32_t)writeSize);
102  onValue(
103  MemoryBufferRef(StringRef((const char *)&FormVal->BlockData[0],
104  FormVal->BlockData.size()),
105  ""));
106  break;
107  }
108  case dwarf::DW_FORM_data1:
109  case dwarf::DW_FORM_ref1:
110  case dwarf::DW_FORM_flag:
111  case dwarf::DW_FORM_strx1:
112  case dwarf::DW_FORM_addrx1:
113  onValue((uint8_t)FormVal->Value);
114  break;
115  case dwarf::DW_FORM_data2:
116  case dwarf::DW_FORM_ref2:
117  case dwarf::DW_FORM_strx2:
118  case dwarf::DW_FORM_addrx2:
119  onValue((uint16_t)FormVal->Value);
120  break;
121  case dwarf::DW_FORM_data4:
122  case dwarf::DW_FORM_ref4:
123  case dwarf::DW_FORM_ref_sup4:
124  case dwarf::DW_FORM_strx4:
125  case dwarf::DW_FORM_addrx4:
126  onValue((uint32_t)FormVal->Value);
127  break;
128  case dwarf::DW_FORM_data8:
129  case dwarf::DW_FORM_ref8:
130  case dwarf::DW_FORM_ref_sup8:
131  onValue((uint64_t)FormVal->Value);
132  break;
133  case dwarf::DW_FORM_sdata:
134  onValue((int64_t)FormVal->Value, true);
135  break;
136  case dwarf::DW_FORM_udata:
137  case dwarf::DW_FORM_ref_udata:
138  onValue((uint64_t)FormVal->Value, true);
139  break;
140  case dwarf::DW_FORM_string:
141  onValue(FormVal->CStr);
142  break;
143  case dwarf::DW_FORM_indirect:
144  onValue((uint64_t)FormVal->Value, true);
145  Indirect = true;
146  Form = static_cast<dwarf::Form>((uint64_t)FormVal->Value);
147  ++FormVal;
148  break;
149  case dwarf::DW_FORM_strp:
150  case dwarf::DW_FORM_sec_offset:
151  case dwarf::DW_FORM_GNU_ref_alt:
152  case dwarf::DW_FORM_GNU_strp_alt:
153  case dwarf::DW_FORM_line_strp:
154  case dwarf::DW_FORM_strp_sup:
155  onVariableSizeValue(FormVal->Value, getOffsetSize(Unit));
156  break;
157  case dwarf::DW_FORM_ref_sig8:
158  onValue((uint64_t)FormVal->Value);
159  break;
160  case dwarf::DW_FORM_GNU_addr_index:
161  case dwarf::DW_FORM_GNU_str_index:
162  onValue((uint64_t)FormVal->Value, true);
163  break;
164  default:
165  break;
166  }
167  } while (Indirect);
168  }
169  onEndDIE(Unit, Entry);
170  }
171  onEndCompileUnit(Unit);
172  }
173 }
174 
175 // Explicitly instantiate the two template expansions.
176 template class DWARFYAML::VisitorImpl<DWARFYAML::Data>;
177 template class DWARFYAML::VisitorImpl<const DWARFYAML::Data>;
llvm::DWARFYAML::Abbrev::Attributes
std::vector< AttributeAbbrev > Attributes
Definition: DWARFYAML.h:57
llvm
This class represents lattice values for constants.
Definition: AllocatorList.h:23
getRefSize
static unsigned getRefSize(const DWARFYAML::Unit &Unit)
Definition: DWARFVisitor.cpp:40
llvm::DWARFYAML::Unit::Length
InitialLength Length
Definition: DWARFYAML.h:101
llvm::DWARFYAML::Unit::Entries
std::vector< Entry > Entries
Definition: DWARFYAML.h:106
llvm::DWARFYAML::Entry::Values
std::vector< FormValue > Values
Definition: DWARFYAML.h:97
llvm_unreachable
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Definition: ErrorHandling.h:135
uint32_t
llvm::DWARFYAML::VisitorImpl
A class to visits DWARFYAML Compile Units and DIEs in preorder.
Definition: DWARFVisitor.h:32
llvm::DWARFYAML::Entry::AbbrCode
llvm::yaml::Hex32 AbbrCode
Definition: DWARFYAML.h:96
DWARFYAML.h
This file declares classes for handling the YAML representation of DWARF Debug Info.
Size
uint32_t Size
Definition: Profile.cpp:46
llvm::StringRef
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48
getOffsetSize
static unsigned getOffsetSize(const DWARFYAML::Unit &Unit)
Definition: DWARFVisitor.cpp:36
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