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   lldbassert(!s_unit.GetSymbolFileDWARF().GetDwoNum());
54   const DWARFUnit &ns_unit = s_unit.GetNonSkeletonUnit();
55   const uint32_t size = m_map.GetSize();
56   for (uint32_t i = 0; i < size; ++i) {
57     const DIERef &die_ref = m_map.GetValueAtIndexUnchecked(i);
58     if (ns_unit.GetSymbolFileDWARF().GetDwoNum() == die_ref.dwo_num() &&
59         ns_unit.GetDebugSection() == die_ref.section() &&
60         ns_unit.GetOffset() <= die_ref.die_offset() &&
61         die_ref.die_offset() < ns_unit.GetNextUnitOffset()) {
62       if (!callback(die_ref))
63         return;
64     }
65   }
66 }
67 
68 void NameToDIE::Dump(Stream *s) {
69   const uint32_t size = m_map.GetSize();
70   for (uint32_t i = 0; i < size; ++i) {
71     s->Format("{0} \"{1}\"\n", m_map.GetValueAtIndexUnchecked(i),
72               m_map.GetCStringAtIndexUnchecked(i));
73   }
74 }
75 
76 void NameToDIE::ForEach(
77     std::function<bool(ConstString name, const DIERef &die_ref)> const
78         &callback) const {
79   const uint32_t size = m_map.GetSize();
80   for (uint32_t i = 0; i < size; ++i) {
81     if (!callback(m_map.GetCStringAtIndexUnchecked(i),
82                   m_map.GetValueAtIndexUnchecked(i)))
83       break;
84   }
85 }
86 
87 void NameToDIE::Append(const NameToDIE &other) {
88   const uint32_t size = other.m_map.GetSize();
89   for (uint32_t i = 0; i < size; ++i) {
90     m_map.Append(other.m_map.GetCStringAtIndexUnchecked(i),
91                  other.m_map.GetValueAtIndexUnchecked(i));
92   }
93 }
94 
95 constexpr llvm::StringLiteral kIdentifierNameToDIE("N2DI");
96 
97 bool NameToDIE::Decode(const DataExtractor &data, lldb::offset_t *offset_ptr,
98                        const StringTableReader &strtab) {
99   m_map.Clear();
100   llvm::StringRef identifier((const char *)data.GetData(offset_ptr, 4), 4);
101   if (identifier != kIdentifierNameToDIE)
102     return false;
103   const uint32_t count = data.GetU32(offset_ptr);
104   m_map.Reserve(count);
105   for (uint32_t i = 0; i < count; ++i) {
106     llvm::StringRef str(strtab.Get(data.GetU32(offset_ptr)));
107     // No empty strings allowed in the name to DIE maps.
108     if (str.empty())
109       return false;
110     if (std::optional<DIERef> die_ref = DIERef::Decode(data, offset_ptr))
111       m_map.Append(ConstString(str), *die_ref);
112     else
113       return false;
114   }
115   // We must sort the UniqueCStringMap after decoding it since it is a vector
116   // of UniqueCStringMap::Entry objects which contain a ConstString and type T.
117   // ConstString objects are sorted by "const char *" and then type T and
118   // the "const char *" are point values that will depend on the order in which
119   // ConstString objects are created and in which of the 256 string pools they
120   // are created in. So after we decode all of the entries, we must sort the
121   // name map to ensure name lookups succeed. If we encode and decode within
122   // the same process we wouldn't need to sort, so unit testing didn't catch
123   // this issue when first checked in.
124   m_map.Sort(std::less<DIERef>());
125   return true;
126 }
127 
128 void NameToDIE::Encode(DataEncoder &encoder, ConstStringTable &strtab) const {
129   encoder.AppendData(kIdentifierNameToDIE);
130   encoder.AppendU32(m_map.GetSize());
131   for (const auto &entry : m_map) {
132     // Make sure there are no empty strings.
133     assert((bool)entry.cstring);
134     encoder.AppendU32(strtab.Add(entry.cstring));
135     entry.value.Encode(encoder);
136   }
137 }
138 
139 bool NameToDIE::operator==(const NameToDIE &rhs) const {
140   const size_t size = m_map.GetSize();
141   if (size != rhs.m_map.GetSize())
142     return false;
143   for (size_t i = 0; i < size; ++i) {
144     if (m_map.GetCStringAtIndex(i) != rhs.m_map.GetCStringAtIndex(i))
145       return false;
146     if (m_map.GetValueRefAtIndexUnchecked(i) !=
147         rhs.m_map.GetValueRefAtIndexUnchecked(i))
148       return false;
149   }
150   return true;
151 }
152