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 <cinttypes>
13#include <cstdint>
14
15using namespace llvm;
16
17DWARFAbbreviationDeclarationSet::DWARFAbbreviationDeclarationSet() {
18 clear();
19}
20
21void DWARFAbbreviationDeclarationSet::clear() {
22 Offset = 0;
23 FirstAbbrCode = 0;
24 Decls.clear();
25}
26
27Error DWARFAbbreviationDeclarationSet::extract(DataExtractor Data,
28 uint64_t *OffsetPtr) {
29 clear();
30 const uint64_t BeginOffset = *OffsetPtr;
31 Offset = BeginOffset;
32 DWARFAbbreviationDeclaration AbbrDecl;
33 uint32_t PrevAbbrCode = 0;
34 while (true) {
35 Expected<DWARFAbbreviationDeclaration::ExtractState> ES =
36 AbbrDecl.extract(Data, OffsetPtr);
37 if (!ES)
38 return ES.takeError();
39
40 if (*ES == DWARFAbbreviationDeclaration::ExtractState::Complete)
41 break;
42
43 if (FirstAbbrCode == 0) {
44 FirstAbbrCode = AbbrDecl.getCode();
45 } else if (PrevAbbrCode + 1 != AbbrDecl.getCode()) {
46 // Codes are not consecutive, can't do O(1) lookups.
47 FirstAbbrCode = UINT32_MAX;
48 }
49 PrevAbbrCode = AbbrDecl.getCode();
50 Decls.push_back(x: std::move(AbbrDecl));
51 }
52 return Error::success();
53}
54
55void DWARFAbbreviationDeclarationSet::dump(raw_ostream &OS) const {
56 for (const auto &Decl : Decls)
57 Decl.dump(OS);
58}
59
60const DWARFAbbreviationDeclaration *
61DWARFAbbreviationDeclarationSet::getAbbreviationDeclaration(
62 uint32_t AbbrCode) const {
63 if (FirstAbbrCode == UINT32_MAX) {
64 for (const auto &Decl : Decls) {
65 if (Decl.getCode() == AbbrCode)
66 return &Decl;
67 }
68 return nullptr;
69 }
70 if (AbbrCode < FirstAbbrCode || AbbrCode >= FirstAbbrCode + Decls.size())
71 return nullptr;
72 return &Decls[AbbrCode - FirstAbbrCode];
73}
74
75std::string DWARFAbbreviationDeclarationSet::getCodeRange() const {
76 // Create a sorted list of all abbrev codes.
77 std::vector<uint32_t> Codes;
78 Codes.reserve(n: Decls.size());
79 for (const auto &Decl : Decls)
80 Codes.push_back(x: Decl.getCode());
81
82 std::string Buffer;
83 raw_string_ostream Stream(Buffer);
84 // Each iteration through this loop represents a single contiguous range in
85 // the set of codes.
86 for (auto Current = Codes.begin(), End = Codes.end(); Current != End;) {
87 uint32_t RangeStart = *Current;
88 // Add the current range start.
89 Stream << *Current;
90 uint32_t RangeEnd = RangeStart;
91 // Find the end of the current range.
92 while (++Current != End && *Current == RangeEnd + 1)
93 ++RangeEnd;
94 // If there is more than one value in the range, add the range end too.
95 if (RangeStart != RangeEnd)
96 Stream << "-" << RangeEnd;
97 // If there is at least one more range, add a separator.
98 if (Current != End)
99 Stream << ", ";
100 }
101 return Buffer;
102}
103
104DWARFDebugAbbrev::DWARFDebugAbbrev(DataExtractor Data)
105 : AbbrDeclSets(), PrevAbbrOffsetPos(AbbrDeclSets.end()), Data(Data) {}
106
107Error DWARFDebugAbbrev::parse() const {
108 if (!Data)
109 return Error::success();
110 uint64_t Offset = 0;
111 auto I = AbbrDeclSets.begin();
112 while (Data->isValidOffset(offset: Offset)) {
113 while (I != AbbrDeclSets.end() && I->first < Offset)
114 ++I;
115 uint64_t CUAbbrOffset = Offset;
116 DWARFAbbreviationDeclarationSet AbbrDecls;
117 if (Error Err = AbbrDecls.extract(Data: *Data, OffsetPtr: &Offset)) {
118 Data = std::nullopt;
119 return Err;
120 }
121 AbbrDeclSets.insert(position: I, x: std::make_pair(x&: CUAbbrOffset, y: std::move(AbbrDecls)));
122 }
123 Data = std::nullopt;
124 return Error::success();
125}
126
127void DWARFDebugAbbrev::dump(raw_ostream &OS) const {
128 if (Error Err = parse())
129 // FIXME: We should propagate this error or otherwise display it.
130 llvm::consumeError(Err: std::move(Err));
131
132 if (AbbrDeclSets.empty()) {
133 OS << "< EMPTY >\n";
134 return;
135 }
136
137 for (const auto &I : AbbrDeclSets) {
138 OS << format(Fmt: "Abbrev table for offset: 0x%8.8" PRIx64 "\n", Vals: I.first);
139 I.second.dump(OS);
140 }
141}
142
143Expected<const DWARFAbbreviationDeclarationSet *>
144DWARFDebugAbbrev::getAbbreviationDeclarationSet(uint64_t CUAbbrOffset) const {
145 const auto End = AbbrDeclSets.end();
146 if (PrevAbbrOffsetPos != End && PrevAbbrOffsetPos->first == CUAbbrOffset) {
147 return &PrevAbbrOffsetPos->second;
148 }
149
150 const auto Pos = AbbrDeclSets.find(x: CUAbbrOffset);
151 if (Pos != End) {
152 PrevAbbrOffsetPos = Pos;
153 return &Pos->second;
154 }
155
156 if (!Data || CUAbbrOffset >= Data->getData().size())
157 return make_error<llvm::object::GenericBinaryError>(
158 Args: "the abbreviation offset into the .debug_abbrev section is not valid");
159
160 uint64_t Offset = CUAbbrOffset;
161 DWARFAbbreviationDeclarationSet AbbrDecls;
162 if (Error Err = AbbrDecls.extract(Data: *Data, OffsetPtr: &Offset))
163 return std::move(Err);
164
165 PrevAbbrOffsetPos =
166 AbbrDeclSets.insert(x: std::make_pair(x&: CUAbbrOffset, y: std::move(AbbrDecls)))
167 .first;
168 return &PrevAbbrOffsetPos->second;
169}
170