1 //===-- NameToDIE.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 "NameToDIE.h"
10 #include "DWARFUnit.h"
11 #include "lldb/Core/DataFileCache.h"
12 #include "lldb/Symbol/ObjectFile.h"
13 #include "lldb/Utility/ConstString.h"
14 #include "lldb/Utility/DataEncoder.h"
15 #include "lldb/Utility/DataExtractor.h"
16 #include "lldb/Utility/RegularExpression.h"
17 #include "lldb/Utility/Stream.h"
18 #include "lldb/Utility/StreamString.h"
19 #include <optional>
20 
21 using namespace lldb;
22 using namespace lldb_private;
23 
24 void NameToDIE::Finalize() {
25   m_map.Sort(std::less<DIERef>());
26   m_map.SizeToFit();
27 }
28 
29 void NameToDIE::Insert(ConstString name, const DIERef &die_ref) {
30   m_map.Append(name, die_ref);
31 }
32 
33 bool NameToDIE::Find(ConstString name,
34                      llvm::function_ref<bool(DIERef ref)> callback) const {
35   for (const auto &entry : m_map.equal_range(name))
36     if (!callback(entry.value))
37       return false;
38   return true;
39 }
40 
41 bool NameToDIE::Find(const RegularExpression &regex,
42                      llvm::function_ref<bool(DIERef ref)> callback) const {
43   for (const auto &entry : m_map)
44     if (regex.Execute(entry.cstring.GetCString())) {
45       if (!callback(entry.value))
46         return false;
47     }
48   return true;
49 }
50 
51 void NameToDIE::FindAllEntriesForUnit(
52     DWARFUnit &s_unit, llvm::function_ref<bool(DIERef ref)> callback) const {
53   const DWARFUnit &ns_unit = s_unit.GetNonSkeletonUnit();
54   const uint32_t size = m_map.GetSize();
55   for (uint32_t i = 0; i < size; ++i) {
56     const DIERef &die_ref = m_map.GetValueAtIndexUnchecked(i);
57     if (ns_unit.GetSymbolFileDWARF().GetFileIndex() == die_ref.file_index() &&
58         ns_unit.GetDebugSection() == die_ref.section() &&
59         ns_unit.GetOffset() <= die_ref.die_offset() &&
60         die_ref.die_offset() < ns_unit.GetNextUnitOffset()) {
61       if (!callback(die_ref))
62         return;
63     }
64   }
65 }
66 
67 void NameToDIE::Dump(Stream *s) {
68   const uint32_t size = m_map.GetSize();
69   for (uint32_t i = 0; i < size; ++i) {
70     s->Format("{0} \"{1}\"\n", m_map.GetValueAtIndexUnchecked(i),
71               m_map.GetCStringAtIndexUnchecked(i));
72   }
73 }
74 
75 void NameToDIE::ForEach(
76     std::function<bool(ConstString name, const DIERef &die_ref)> const
77         &callback) const {
78   const uint32_t size = m_map.GetSize();
79   for (uint32_t i = 0; i < size; ++i) {
80     if (!callback(m_map.GetCStringAtIndexUnchecked(i),
81                   m_map.GetValueAtIndexUnchecked(i)))
82       break;
83   }
84 }
85 
86 void NameToDIE::Append(const NameToDIE &other) {
87   const uint32_t size = other.m_map.GetSize();
88   for (uint32_t i = 0; i < size; ++i) {
89     m_map.Append(other.m_map.GetCStringAtIndexUnchecked(i),
90                  other.m_map.GetValueAtIndexUnchecked(i));
91   }
92 }
93 
94 constexpr llvm::StringLiteral kIdentifierNameToDIE("N2DI");
95 
96 bool NameToDIE::Decode(const DataExtractor &data, lldb::offset_t *offset_ptr,
97                        const StringTableReader &strtab) {
98   m_map.Clear();
99   llvm::StringRef identifier((const char *)data.GetData(offset_ptr, 4), 4);
100   if (identifier != kIdentifierNameToDIE)
101     return false;
102   const uint32_t count = data.GetU32(offset_ptr);
103   m_map.Reserve(count);
104   for (uint32_t i = 0; i < count; ++i) {
105     llvm::StringRef str(strtab.Get(data.GetU32(offset_ptr)));
106     // No empty strings allowed in the name to DIE maps.
107     if (str.empty())
108       return false;
109     if (std::optional<DIERef> die_ref = DIERef::Decode(data, offset_ptr))
110       m_map.Append(ConstString(str), *die_ref);
111     else
112       return false;
113   }
114   // We must sort the UniqueCStringMap after decoding it since it is a vector
115   // of UniqueCStringMap::Entry objects which contain a ConstString and type T.
116   // ConstString objects are sorted by "const char *" and then type T and
117   // the "const char *" are point values that will depend on the order in which
118   // ConstString objects are created and in which of the 256 string pools they
119   // are created in. So after we decode all of the entries, we must sort the
120   // name map to ensure name lookups succeed. If we encode and decode within
121   // the same process we wouldn't need to sort, so unit testing didn't catch
122   // this issue when first checked in.
123   m_map.Sort(std::less<DIERef>());
124   return true;
125 }
126 
127 void NameToDIE::Encode(DataEncoder &encoder, ConstStringTable &strtab) const {
128   encoder.AppendData(kIdentifierNameToDIE);
129   encoder.AppendU32(m_map.GetSize());
130   for (const auto &entry : m_map) {
131     // Make sure there are no empty strings.
132     assert((bool)entry.cstring);
133     encoder.AppendU32(strtab.Add(entry.cstring));
134     entry.value.Encode(encoder);
135   }
136 }
137 
138 bool NameToDIE::operator==(const NameToDIE &rhs) const {
139   const size_t size = m_map.GetSize();
140   if (size != rhs.m_map.GetSize())
141     return false;
142   for (size_t i = 0; i < size; ++i) {
143     if (m_map.GetCStringAtIndex(i) != rhs.m_map.GetCStringAtIndex(i))
144       return false;
145     if (m_map.GetValueRefAtIndexUnchecked(i) !=
146         rhs.m_map.GetValueRefAtIndexUnchecked(i))
147       return false;
148   }
149   return true;
150 }
151