DWARFDebugAbbrev.cpp revision 360784 
1//===- DWARFDebugAbbrev.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/DWARFDebugAbbrev.h"
10#include "llvm/Support/Format.h"
11#include "llvm/Support/raw_ostream.h"
12#include <algorithm>
13#include <cinttypes>
14#include <cstdint>
15
16using namespace llvm;
17
18DWARFAbbreviationDeclarationSet::DWARFAbbreviationDeclarationSet() {
19  clear();
20}
21
22void DWARFAbbreviationDeclarationSet::clear() {
23  Offset = 0;
24  FirstAbbrCode = 0;
25  Decls.clear();
26}
27
28bool DWARFAbbreviationDeclarationSet::extract(DataExtractor Data,
29                                              uint64_t *OffsetPtr) {
30  clear();
31  const uint64_t BeginOffset = *OffsetPtr;
32  Offset = BeginOffset;
33  DWARFAbbreviationDeclaration AbbrDecl;
34  uint32_t PrevAbbrCode = 0;
35  while (AbbrDecl.extract(Data, OffsetPtr)) {
36    if (FirstAbbrCode == 0) {
37      FirstAbbrCode = AbbrDecl.getCode();
38    } else {
39      if (PrevAbbrCode + 1 != AbbrDecl.getCode()) {
40        // Codes are not consecutive, can't do O(1) lookups.
41        FirstAbbrCode = UINT32_MAX;
42      }
43    }
44    PrevAbbrCode = AbbrDecl.getCode();
45    Decls.push_back(std::move(AbbrDecl));
46  }
47  return BeginOffset != *OffsetPtr;
48}
49
50void DWARFAbbreviationDeclarationSet::dump(raw_ostream &OS) const {
51  for (const auto &Decl : Decls)
52    Decl.dump(OS);
53}
54
55const DWARFAbbreviationDeclaration *
56DWARFAbbreviationDeclarationSet::getAbbreviationDeclaration(
57    uint32_t AbbrCode) const {
58  if (FirstAbbrCode == UINT32_MAX) {
59    for (const auto &Decl : Decls) {
60      if (Decl.getCode() == AbbrCode)
61        return &Decl;
62    }
63    return nullptr;
64  }
65  if (AbbrCode < FirstAbbrCode || AbbrCode >= FirstAbbrCode + Decls.size())
66    return nullptr;
67  return &Decls[AbbrCode - FirstAbbrCode];
68}
69
70DWARFDebugAbbrev::DWARFDebugAbbrev() { clear(); }
71
72void DWARFDebugAbbrev::clear() {
73  AbbrDeclSets.clear();
74  PrevAbbrOffsetPos = AbbrDeclSets.end();
75}
76
77void DWARFDebugAbbrev::extract(DataExtractor Data) {
78  clear();
79  this->Data = Data;
80}
81
82void DWARFDebugAbbrev::parse() const {
83  if (!Data)
84    return;
85  uint64_t Offset = 0;
86  auto I = AbbrDeclSets.begin();
87  while (Data->isValidOffset(Offset)) {
88    while (I != AbbrDeclSets.end() && I->first < Offset)
89      ++I;
90    uint64_t CUAbbrOffset = Offset;
91    DWARFAbbreviationDeclarationSet AbbrDecls;
92    if (!AbbrDecls.extract(*Data, &Offset))
93      break;
94    AbbrDeclSets.insert(I, std::make_pair(CUAbbrOffset, std::move(AbbrDecls)));
95  }
96  Data = None;
97}
98
99void DWARFDebugAbbrev::dump(raw_ostream &OS) const {
100  parse();
101
102  if (AbbrDeclSets.empty()) {
103    OS << "< EMPTY >\n";
104    return;
105  }
106
107  for (const auto &I : AbbrDeclSets) {
108    OS << format("Abbrev table for offset: 0x%8.8" PRIx64 "\n", I.first);
109    I.second.dump(OS);
110  }
111}
112
113const DWARFAbbreviationDeclarationSet*
114DWARFDebugAbbrev::getAbbreviationDeclarationSet(uint64_t CUAbbrOffset) const {
115  const auto End = AbbrDeclSets.end();
116  if (PrevAbbrOffsetPos != End && PrevAbbrOffsetPos->first == CUAbbrOffset) {
117    return &(PrevAbbrOffsetPos->second);
118  }
119
120  const auto Pos = AbbrDeclSets.find(CUAbbrOffset);
121  if (Pos != End) {
122    PrevAbbrOffsetPos = Pos;
123    return &(Pos->second);
124  }
125
126  if (Data && CUAbbrOffset < Data->getData().size()) {
127    uint64_t Offset = CUAbbrOffset;
128    DWARFAbbreviationDeclarationSet AbbrDecls;
129    if (!AbbrDecls.extract(*Data, &Offset))
130      return nullptr;
131    PrevAbbrOffsetPos =
132        AbbrDeclSets.insert(std::make_pair(CUAbbrOffset, std::move(AbbrDecls)))
133            .first;
134    return &PrevAbbrOffsetPos->second;
135  }
136
137  return nullptr;
138}
139