xref: /llvm-project/lldb/source/Plugins/ObjectFile/JSON/ObjectFileJSON.cpp (revision cf3524a5746f9498280b3a9180b75575c0065d1a)
1 //===-- ObjectFileJSON.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 "Plugins/ObjectFile/JSON/ObjectFileJSON.h"
10 #include "lldb/Core/Module.h"
11 #include "lldb/Core/ModuleSpec.h"
12 #include "lldb/Core/PluginManager.h"
13 #include "lldb/Core/Section.h"
14 #include "lldb/Symbol/Symbol.h"
15 #include "lldb/Utility/LLDBLog.h"
16 #include "lldb/Utility/Log.h"
17 #include "llvm/ADT/DenseSet.h"
18 #include <optional>
19 
20 using namespace llvm;
21 using namespace lldb;
22 using namespace lldb_private;
23 
24 LLDB_PLUGIN_DEFINE(ObjectFileJSON)
25 
26 char ObjectFileJSON::ID;
27 
28 void ObjectFileJSON::Initialize() {
29   PluginManager::RegisterPlugin(GetPluginNameStatic(),
30                                 GetPluginDescriptionStatic(), CreateInstance,
31                                 CreateMemoryInstance, GetModuleSpecifications);
32 }
33 
34 void ObjectFileJSON::Terminate() {
35   PluginManager::UnregisterPlugin(CreateInstance);
36 }
37 
38 ObjectFile *
39 ObjectFileJSON::CreateInstance(const ModuleSP &module_sp, DataBufferSP data_sp,
40                                offset_t data_offset, const FileSpec *file,
41                                offset_t file_offset, offset_t length) {
42   if (!data_sp) {
43     data_sp = MapFileData(*file, length, file_offset);
44     if (!data_sp)
45       return nullptr;
46     data_offset = 0;
47   }
48 
49   if (!MagicBytesMatch(data_sp, 0, data_sp->GetByteSize()))
50     return nullptr;
51 
52   if (data_sp->GetByteSize() < length) {
53     data_sp = MapFileData(*file, length, file_offset);
54     if (!data_sp)
55       return nullptr;
56     data_offset = 0;
57   }
58 
59   auto text =
60       llvm::StringRef(reinterpret_cast<const char *>(data_sp->GetBytes()));
61 
62   Expected<json::Value> json = json::parse(text);
63   if (!json) {
64     llvm::consumeError(json.takeError());
65     return nullptr;
66   }
67 
68   json::Path::Root root;
69   Header header;
70   if (!fromJSON(*json, header, root))
71     return nullptr;
72 
73   ArchSpec arch(header.triple);
74   UUID uuid;
75   uuid.SetFromStringRef(header.uuid);
76 
77   Body body;
78   fromJSON(*json, body, root);
79 
80   return new ObjectFileJSON(module_sp, data_sp, data_offset, file, file_offset,
81                             length, std::move(arch), std::move(uuid),
82                             std::move(body.symbols));
83 }
84 
85 ObjectFile *ObjectFileJSON::CreateMemoryInstance(const ModuleSP &module_sp,
86                                                  WritableDataBufferSP data_sp,
87                                                  const ProcessSP &process_sp,
88                                                  addr_t header_addr) {
89   return nullptr;
90 }
91 
92 size_t ObjectFileJSON::GetModuleSpecifications(
93     const FileSpec &file, DataBufferSP &data_sp, offset_t data_offset,
94     offset_t file_offset, offset_t length, ModuleSpecList &specs) {
95 
96   if (!MagicBytesMatch(data_sp, data_offset, data_sp->GetByteSize()))
97     return 0;
98 
99   auto text =
100       llvm::StringRef(reinterpret_cast<const char *>(data_sp->GetBytes()));
101 
102   Expected<json::Value> json = json::parse(text);
103   if (!json) {
104     llvm::consumeError(json.takeError());
105     return 0;
106   }
107 
108   json::Path::Root root;
109   Header header;
110   if (!fromJSON(*json, header, root))
111     return 0;
112 
113   ArchSpec arch(header.triple);
114   UUID uuid;
115   uuid.SetFromStringRef(header.uuid);
116 
117   ModuleSpec spec(file, std::move(arch));
118   spec.GetUUID() = std::move(uuid);
119   specs.Append(spec);
120   return 1;
121 }
122 
123 ObjectFileJSON::ObjectFileJSON(const ModuleSP &module_sp, DataBufferSP &data_sp,
124                                offset_t data_offset, const FileSpec *file,
125                                offset_t offset, offset_t length, ArchSpec arch,
126                                UUID uuid, std::vector<JSONSymbol> symbols)
127     : ObjectFile(module_sp, file, offset, length, data_sp, data_offset),
128       m_arch(std::move(arch)), m_uuid(std::move(uuid)),
129       m_symbols(std::move(symbols)) {}
130 
131 bool ObjectFileJSON::ParseHeader() {
132   // We already parsed the header during initialization.
133   return true;
134 }
135 
136 void ObjectFileJSON::ParseSymtab(Symtab &symtab) {
137   Log *log = GetLog(LLDBLog::Symbols);
138   SectionList *section_list = GetModule()->GetSectionList();
139   for (JSONSymbol json_symbol : m_symbols) {
140     llvm::Expected<Symbol> symbol = Symbol::FromJSON(json_symbol, section_list);
141     if (!symbol) {
142       LLDB_LOG_ERROR(log, symbol.takeError(), "invalid symbol");
143       continue;
144     }
145     symtab.AddSymbol(*symbol);
146   }
147   symtab.Finalize();
148 }
149 
150 void ObjectFileJSON::CreateSections(SectionList &unified_section_list) {}
151 
152 bool ObjectFileJSON::MagicBytesMatch(DataBufferSP data_sp,
153                                      lldb::addr_t data_offset,
154                                      lldb::addr_t data_length) {
155   DataExtractor data;
156   data.SetData(data_sp, data_offset, data_length);
157   lldb::offset_t offset = 0;
158   uint32_t magic = data.GetU8(&offset);
159   return magic == '{';
160 }
161 
162 namespace lldb_private {
163 
164 bool fromJSON(const json::Value &value, ObjectFileJSON::Header &header,
165               json::Path path) {
166   json::ObjectMapper o(value, path);
167   return o && o.map("triple", header.triple) && o.map("uuid", header.uuid);
168 }
169 
170 bool fromJSON(const json::Value &value, ObjectFileJSON::Body &body,
171               json::Path path) {
172   json::ObjectMapper o(value, path);
173   return o && o.map("symbols", body.symbols);
174 }
175 
176 } // namespace lldb_private
177