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
16 using namespace llvm;
17
DWARFAbbreviationDeclarationSet()18 DWARFAbbreviationDeclarationSet::DWARFAbbreviationDeclarationSet() {
19 clear();
20 }
21
clear()22 void DWARFAbbreviationDeclarationSet::clear() {
23 Offset = 0;
24 FirstAbbrCode = 0;
25 Decls.clear();
26 }
27
extract(DataExtractor Data,uint64_t * OffsetPtr)28 bool 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
dump(raw_ostream & OS) const50 void DWARFAbbreviationDeclarationSet::dump(raw_ostream &OS) const {
51 for (const auto &Decl : Decls)
52 Decl.dump(OS);
53 }
54
55 const DWARFAbbreviationDeclaration *
getAbbreviationDeclaration(uint32_t AbbrCode) const56 DWARFAbbreviationDeclarationSet::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
getCodeRange() const70 std::string DWARFAbbreviationDeclarationSet::getCodeRange() const {
71 // Create a sorted list of all abbrev codes.
72 std::vector<uint32_t> Codes;
73 Codes.reserve(Decls.size());
74 for (const auto &Decl : Decls)
75 Codes.push_back(Decl.getCode());
76
77 std::string Buffer;
78 raw_string_ostream Stream(Buffer);
79 // Each iteration through this loop represents a single contiguous range in
80 // the set of codes.
81 for (auto Current = Codes.begin(), End = Codes.end(); Current != End;) {
82 uint32_t RangeStart = *Current;
83 // Add the current range start.
84 Stream << *Current;
85 uint32_t RangeEnd = RangeStart;
86 // Find the end of the current range.
87 while (++Current != End && *Current == RangeEnd + 1)
88 ++RangeEnd;
89 // If there is more than one value in the range, add the range end too.
90 if (RangeStart != RangeEnd)
91 Stream << "-" << RangeEnd;
92 // If there is at least one more range, add a separator.
93 if (Current != End)
94 Stream << ", ";
95 }
96 return Buffer;
97 }
98
DWARFDebugAbbrev()99 DWARFDebugAbbrev::DWARFDebugAbbrev() { clear(); }
100
clear()101 void DWARFDebugAbbrev::clear() {
102 AbbrDeclSets.clear();
103 PrevAbbrOffsetPos = AbbrDeclSets.end();
104 }
105
extract(DataExtractor Data)106 void DWARFDebugAbbrev::extract(DataExtractor Data) {
107 clear();
108 this->Data = Data;
109 }
110
parse() const111 void DWARFDebugAbbrev::parse() const {
112 if (!Data)
113 return;
114 uint64_t Offset = 0;
115 auto I = AbbrDeclSets.begin();
116 while (Data->isValidOffset(Offset)) {
117 while (I != AbbrDeclSets.end() && I->first < Offset)
118 ++I;
119 uint64_t CUAbbrOffset = Offset;
120 DWARFAbbreviationDeclarationSet AbbrDecls;
121 if (!AbbrDecls.extract(*Data, &Offset))
122 break;
123 AbbrDeclSets.insert(I, std::make_pair(CUAbbrOffset, std::move(AbbrDecls)));
124 }
125 Data = std::nullopt;
126 }
127
dump(raw_ostream & OS) const128 void DWARFDebugAbbrev::dump(raw_ostream &OS) const {
129 parse();
130
131 if (AbbrDeclSets.empty()) {
132 OS << "< EMPTY >\n";
133 return;
134 }
135
136 for (const auto &I : AbbrDeclSets) {
137 OS << format("Abbrev table for offset: 0x%8.8" PRIx64 "\n", I.first);
138 I.second.dump(OS);
139 }
140 }
141
142 const DWARFAbbreviationDeclarationSet*
getAbbreviationDeclarationSet(uint64_t CUAbbrOffset) const143 DWARFDebugAbbrev::getAbbreviationDeclarationSet(uint64_t CUAbbrOffset) const {
144 const auto End = AbbrDeclSets.end();
145 if (PrevAbbrOffsetPos != End && PrevAbbrOffsetPos->first == CUAbbrOffset) {
146 return &(PrevAbbrOffsetPos->second);
147 }
148
149 const auto Pos = AbbrDeclSets.find(CUAbbrOffset);
150 if (Pos != End) {
151 PrevAbbrOffsetPos = Pos;
152 return &(Pos->second);
153 }
154
155 if (Data && CUAbbrOffset < Data->getData().size()) {
156 uint64_t Offset = CUAbbrOffset;
157 DWARFAbbreviationDeclarationSet AbbrDecls;
158 if (!AbbrDecls.extract(*Data, &Offset))
159 return nullptr;
160 PrevAbbrOffsetPos =
161 AbbrDeclSets.insert(std::make_pair(CUAbbrOffset, std::move(AbbrDecls)))
162 .first;
163 return &PrevAbbrOffsetPos->second;
164 }
165
166 return nullptr;
167 }
168