DWARFAbbreviationDeclaration.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338 
1//===-- DWARFAbbreviationDeclaration.cpp ----------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "DWARFAbbreviationDeclaration.h"
11#include "llvm/Support/Dwarf.h"
12#include "llvm/Support/Format.h"
13#include "llvm/Support/raw_ostream.h"
14using namespace llvm;
15using namespace dwarf;
16
17void DWARFAbbreviationDeclaration::clear() {
18  Code = 0;
19  Tag = 0;
20  HasChildren = false;
21  AttributeSpecs.clear();
22}
23
24DWARFAbbreviationDeclaration::DWARFAbbreviationDeclaration() {
25  clear();
26}
27
28bool
29DWARFAbbreviationDeclaration::extract(DataExtractor Data, uint32_t* OffsetPtr) {
30  clear();
31  Code = Data.getULEB128(OffsetPtr);
32  if (Code == 0) {
33    return false;
34  }
35  Tag = Data.getULEB128(OffsetPtr);
36  uint8_t ChildrenByte = Data.getU8(OffsetPtr);
37  HasChildren = (ChildrenByte == DW_CHILDREN_yes);
38
39  while (true) {
40    uint32_t CurOffset = *OffsetPtr;
41    uint16_t Attr = Data.getULEB128(OffsetPtr);
42    if (CurOffset == *OffsetPtr) {
43      clear();
44      return false;
45    }
46    CurOffset = *OffsetPtr;
47    uint16_t Form = Data.getULEB128(OffsetPtr);
48    if (CurOffset == *OffsetPtr) {
49      clear();
50      return false;
51    }
52    if (Attr == 0 && Form == 0)
53      break;
54    AttributeSpecs.push_back(AttributeSpec(Attr, Form));
55  }
56
57  if (Tag == 0) {
58    clear();
59    return false;
60  }
61  return true;
62}
63
64void DWARFAbbreviationDeclaration::dump(raw_ostream &OS) const {
65  const char *tagString = TagString(getTag());
66  OS << '[' << getCode() << "] ";
67  if (tagString)
68    OS << tagString;
69  else
70    OS << format("DW_TAG_Unknown_%x", getTag());
71  OS << "\tDW_CHILDREN_" << (hasChildren() ? "yes" : "no") << '\n';
72  for (const AttributeSpec &Spec : AttributeSpecs) {
73    OS << '\t';
74    const char *attrString = AttributeString(Spec.Attr);
75    if (attrString)
76      OS << attrString;
77    else
78      OS << format("DW_AT_Unknown_%x", Spec.Attr);
79    OS << '\t';
80    const char *formString = FormEncodingString(Spec.Form);
81    if (formString)
82      OS << formString;
83    else
84      OS << format("DW_FORM_Unknown_%x", Spec.Form);
85    OS << '\n';
86  }
87  OS << '\n';
88}
89
90uint32_t
91DWARFAbbreviationDeclaration::findAttributeIndex(uint16_t attr) const {
92  for (uint32_t i = 0, e = AttributeSpecs.size(); i != e; ++i) {
93    if (AttributeSpecs[i].Attr == attr)
94      return i;
95  }
96  return -1U;
97}
98