DWARFDebugAbbrev.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
1//===-- DWARFDebugAbbrev.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 "DWARFDebugAbbrev.h"
11#include "llvm/Support/Format.h"
12#include "llvm/Support/raw_ostream.h"
13using namespace llvm;
14
15DWARFAbbreviationDeclarationSet::DWARFAbbreviationDeclarationSet() {
16  clear();
17}
18
19void DWARFAbbreviationDeclarationSet::clear() {
20  Offset = 0;
21  FirstAbbrCode = 0;
22  Decls.clear();
23}
24
25bool DWARFAbbreviationDeclarationSet::extract(DataExtractor Data,
26                                              uint32_t *OffsetPtr) {
27  clear();
28  const uint32_t BeginOffset = *OffsetPtr;
29  Offset = BeginOffset;
30  DWARFAbbreviationDeclaration AbbrDecl;
31  uint32_t PrevAbbrCode = 0;
32  while (AbbrDecl.extract(Data, OffsetPtr)) {
33    Decls.push_back(AbbrDecl);
34    if (FirstAbbrCode == 0) {
35      FirstAbbrCode = AbbrDecl.getCode();
36    } else {
37      if (PrevAbbrCode + 1 != AbbrDecl.getCode()) {
38        // Codes are not consecutive, can't do O(1) lookups.
39        FirstAbbrCode = UINT32_MAX;
40      }
41    }
42    PrevAbbrCode = AbbrDecl.getCode();
43  }
44  return BeginOffset != *OffsetPtr;
45}
46
47void DWARFAbbreviationDeclarationSet::dump(raw_ostream &OS) const {
48  for (const auto &Decl : Decls)
49    Decl.dump(OS);
50}
51
52const DWARFAbbreviationDeclaration *
53DWARFAbbreviationDeclarationSet::getAbbreviationDeclaration(
54    uint32_t AbbrCode) const {
55  if (FirstAbbrCode == UINT32_MAX) {
56    for (const auto &Decl : Decls) {
57      if (Decl.getCode() == AbbrCode)
58        return &Decl;
59    }
60    return nullptr;
61  }
62  if (AbbrCode < FirstAbbrCode || AbbrCode >= FirstAbbrCode + Decls.size())
63    return nullptr;
64  return &Decls[AbbrCode - FirstAbbrCode];
65}
66
67DWARFDebugAbbrev::DWARFDebugAbbrev() {
68  clear();
69}
70
71void DWARFDebugAbbrev::clear() {
72  AbbrDeclSets.clear();
73  PrevAbbrOffsetPos = AbbrDeclSets.end();
74}
75
76void DWARFDebugAbbrev::extract(DataExtractor Data) {
77  clear();
78
79  uint32_t Offset = 0;
80  DWARFAbbreviationDeclarationSet AbbrDecls;
81  while (Data.isValidOffset(Offset)) {
82    uint32_t CUAbbrOffset = Offset;
83    if (!AbbrDecls.extract(Data, &Offset))
84      break;
85    AbbrDeclSets[CUAbbrOffset] = AbbrDecls;
86  }
87}
88
89void DWARFDebugAbbrev::dump(raw_ostream &OS) const {
90  if (AbbrDeclSets.empty()) {
91    OS << "< EMPTY >\n";
92    return;
93  }
94
95  for (const auto &I : AbbrDeclSets) {
96    OS << format("Abbrev table for offset: 0x%8.8" PRIx64 "\n", I.first);
97    I.second.dump(OS);
98  }
99}
100
101const DWARFAbbreviationDeclarationSet*
102DWARFDebugAbbrev::getAbbreviationDeclarationSet(uint64_t CUAbbrOffset) const {
103  const auto End = AbbrDeclSets.end();
104  if (PrevAbbrOffsetPos != End && PrevAbbrOffsetPos->first == CUAbbrOffset) {
105    return &(PrevAbbrOffsetPos->second);
106  }
107
108  const auto Pos = AbbrDeclSets.find(CUAbbrOffset);
109  if (Pos != End) {
110    PrevAbbrOffsetPos = Pos;
111    return &(Pos->second);
112  }
113
114  return nullptr;
115}
116