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
28Error 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 (true) {
36 Expected<DWARFAbbreviationDeclaration::ExtractState> ES =
37 AbbrDecl.extract(Data, OffsetPtr);
38 if (!ES)
39 return ES.takeError();
40
41 if (*ES == DWARFAbbreviationDeclaration::ExtractState::Complete)
42 break;
43
44 if (FirstAbbrCode == 0) {
45 FirstAbbrCode = AbbrDecl.getCode();
46 } else if (PrevAbbrCode + 1 != AbbrDecl.getCode()) {
47 // Codes are not consecutive, can't do O(1) lookups.
48 FirstAbbrCode = UINT32_MAX;
49 }
50 PrevAbbrCode = AbbrDecl.getCode();
51 Decls.push_back(x: std::move(AbbrDecl));
52 }
53 return Error::success();
54}
55
56void DWARFAbbreviationDeclarationSet::dump(raw_ostream &OS) const {
57 for (const auto &Decl : Decls)
58 Decl.dump(OS);
59}
60
61const DWARFAbbreviationDeclaration *
62DWARFAbbreviationDeclarationSet::getAbbreviationDeclaration(
63 uint32_t AbbrCode) const {
64 if (FirstAbbrCode == UINT32_MAX) {
65 for (const auto &Decl : Decls) {
66 if (Decl.getCode() == AbbrCode)
67 return &Decl;
68 }
69 return nullptr;
70 }
71 if (AbbrCode < FirstAbbrCode || AbbrCode >= FirstAbbrCode + Decls.size())
72 return nullptr;
73 return &Decls[AbbrCode - FirstAbbrCode];
74}
75
76std::string DWARFAbbreviationDeclarationSet::getCodeRange() const {
77 // Create a sorted list of all abbrev codes.
78 std::vector<uint32_t> Codes;
79 Codes.reserve(n: Decls.size());
80 for (const auto &Decl : Decls)
81 Codes.push_back(x: Decl.getCode());
82
83 std::string Buffer;
84 raw_string_ostream Stream(Buffer);
85 // Each iteration through this loop represents a single contiguous range in
86 // the set of codes.
87 for (auto Current = Codes.begin(), End = Codes.end(); Current != End;) {
88 uint32_t RangeStart = *Current;
89 // Add the current range start.
90 Stream << *Current;
91 uint32_t RangeEnd = RangeStart;
92 // Find the end of the current range.
93 while (++Current != End && *Current == RangeEnd + 1)
94 ++RangeEnd;
95 // If there is more than one value in the range, add the range end too.
96 if (RangeStart != RangeEnd)
97 Stream << "-" << RangeEnd;
98 // If there is at least one more range, add a separator.
99 if (Current != End)
100 Stream << ", ";
101 }
102 return Buffer;
103}
104
105DWARFDebugAbbrev::DWARFDebugAbbrev(DataExtractor Data)
106 : AbbrDeclSets(), PrevAbbrOffsetPos(AbbrDeclSets.end()), Data(Data) {}
107
108Error DWARFDebugAbbrev::parse() const {
109 if (!Data)
110 return Error::success();
111 uint64_t Offset = 0;
112 auto I = AbbrDeclSets.begin();
113 while (Data->isValidOffset(offset: Offset)) {
114 while (I != AbbrDeclSets.end() && I->first < Offset)
115 ++I;
116 uint64_t CUAbbrOffset = Offset;
117 DWARFAbbreviationDeclarationSet AbbrDecls;
118 if (Error Err = AbbrDecls.extract(Data: *Data, OffsetPtr: &Offset)) {
119 Data = std::nullopt;
120 return Err;
121 }
122 AbbrDeclSets.insert(position: I, x: std::make_pair(x&: CUAbbrOffset, y: std::move(AbbrDecls)));
123 }
124 Data = std::nullopt;
125 return Error::success();
126}
127
128void DWARFDebugAbbrev::dump(raw_ostream &OS) const {
129 if (Error Err = parse())
130 // FIXME: We should propagate this error or otherwise display it.
131 llvm::consumeError(Err: std::move(Err));
132
133 if (AbbrDeclSets.empty()) {
134 OS << "< EMPTY >\n";
135 return;
136 }
137
138 for (const auto &I : AbbrDeclSets) {
139 OS << format(Fmt: "Abbrev table for offset: 0x%8.8" PRIx64 "\n", Vals: I.first);
140 I.second.dump(OS);
141 }
142}
143
144Expected<const DWARFAbbreviationDeclarationSet *>
145DWARFDebugAbbrev::getAbbreviationDeclarationSet(uint64_t CUAbbrOffset) const {
146 const auto End = AbbrDeclSets.end();
147 if (PrevAbbrOffsetPos != End && PrevAbbrOffsetPos->first == CUAbbrOffset) {
148 return &PrevAbbrOffsetPos->second;
149 }
150
151 const auto Pos = AbbrDeclSets.find(x: CUAbbrOffset);
152 if (Pos != End) {
153 PrevAbbrOffsetPos = Pos;
154 return &Pos->second;
155 }
156
157 if (!Data || CUAbbrOffset >= Data->getData().size())
158 return make_error<llvm::object::GenericBinaryError>(
159 Args: "the abbreviation offset into the .debug_abbrev section is not valid");
160
161 uint64_t Offset = CUAbbrOffset;
162 DWARFAbbreviationDeclarationSet AbbrDecls;
163 if (Error Err = AbbrDecls.extract(Data: *Data, OffsetPtr: &Offset))
164 return std::move(Err);
165
166 PrevAbbrOffsetPos =
167 AbbrDeclSets.insert(x: std::make_pair(x&: CUAbbrOffset, y: std::move(AbbrDecls)))
168 .first;
169 return &PrevAbbrOffsetPos->second;
170}
171