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
DWARFDebugAbbrev()70 DWARFDebugAbbrev::DWARFDebugAbbrev() { clear(); }
71
clear()72 void DWARFDebugAbbrev::clear() {
73 AbbrDeclSets.clear();
74 PrevAbbrOffsetPos = AbbrDeclSets.end();
75 }
76
extract(DataExtractor Data)77 void DWARFDebugAbbrev::extract(DataExtractor Data) {
78 clear();
79 this->Data = Data;
80 }
81
parse() const82 void 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
dump(raw_ostream & OS) const99 void 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
113 const DWARFAbbreviationDeclarationSet*
getAbbreviationDeclarationSet(uint64_t CUAbbrOffset) const114 DWARFDebugAbbrev::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