1 //===-- ObjectFileJIT.cpp ---------------------------------------*- C++ -*-===//
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/ADT/StringRef.h"
10 
11 #include "ObjectFileJIT.h"
12 #include "lldb/Core/Debugger.h"
13 #include "lldb/Core/FileSpecList.h"
14 #include "lldb/Core/Module.h"
15 #include "lldb/Core/ModuleSpec.h"
16 #include "lldb/Core/PluginManager.h"
17 #include "lldb/Core/Section.h"
18 #include "lldb/Core/StreamFile.h"
19 #include "lldb/Host/Host.h"
20 #include "lldb/Symbol/ObjectFile.h"
21 #include "lldb/Target/Platform.h"
22 #include "lldb/Target/Process.h"
23 #include "lldb/Target/SectionLoadList.h"
24 #include "lldb/Target/Target.h"
25 #include "lldb/Utility/ArchSpec.h"
26 #include "lldb/Utility/DataBuffer.h"
27 #include "lldb/Utility/DataBufferHeap.h"
28 #include "lldb/Utility/FileSpec.h"
29 #include "lldb/Utility/Log.h"
30 #include "lldb/Utility/RangeMap.h"
31 #include "lldb/Utility/StreamString.h"
32 #include "lldb/Utility/Timer.h"
33 #include "lldb/Utility/UUID.h"
34 
35 #ifndef __APPLE__
36 #include "Utility/UuidCompatibility.h"
37 #endif
38 
39 using namespace lldb;
40 using namespace lldb_private;
41 
42 char ObjectFileJIT::ID;
43 
44 void ObjectFileJIT::Initialize() {
45   PluginManager::RegisterPlugin(GetPluginNameStatic(),
46                                 GetPluginDescriptionStatic(), CreateInstance,
47                                 CreateMemoryInstance, GetModuleSpecifications);
48 }
49 
50 void ObjectFileJIT::Terminate() {
51   PluginManager::UnregisterPlugin(CreateInstance);
52 }
53 
54 lldb_private::ConstString ObjectFileJIT::GetPluginNameStatic() {
55   static ConstString g_name("jit");
56   return g_name;
57 }
58 
59 const char *ObjectFileJIT::GetPluginDescriptionStatic() {
60   return "JIT code object file";
61 }
62 
63 ObjectFile *ObjectFileJIT::CreateInstance(const lldb::ModuleSP &module_sp,
64                                           DataBufferSP &data_sp,
65                                           lldb::offset_t data_offset,
66                                           const FileSpec *file,
67                                           lldb::offset_t file_offset,
68                                           lldb::offset_t length) {
69   // JIT'ed object file is backed by the ObjectFileJITDelegate, never read from
70   // a file
71   return nullptr;
72 }
73 
74 ObjectFile *ObjectFileJIT::CreateMemoryInstance(const lldb::ModuleSP &module_sp,
75                                                 DataBufferSP &data_sp,
76                                                 const ProcessSP &process_sp,
77                                                 lldb::addr_t header_addr) {
78   // JIT'ed object file is backed by the ObjectFileJITDelegate, never read from
79   // memory
80   return nullptr;
81 }
82 
83 size_t ObjectFileJIT::GetModuleSpecifications(
84     const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp,
85     lldb::offset_t data_offset, lldb::offset_t file_offset,
86     lldb::offset_t length, lldb_private::ModuleSpecList &specs) {
87   // JIT'ed object file can't be read from a file on disk
88   return 0;
89 }
90 
91 ObjectFileJIT::ObjectFileJIT(const lldb::ModuleSP &module_sp,
92                              const ObjectFileJITDelegateSP &delegate_sp)
93     : ObjectFile(module_sp, nullptr, 0, 0, DataBufferSP(), 0), m_delegate_wp() {
94   if (delegate_sp) {
95     m_delegate_wp = delegate_sp;
96     m_data.SetByteOrder(delegate_sp->GetByteOrder());
97     m_data.SetAddressByteSize(delegate_sp->GetAddressByteSize());
98   }
99 }
100 
101 ObjectFileJIT::~ObjectFileJIT() {}
102 
103 bool ObjectFileJIT::ParseHeader() {
104   // JIT code is never in a file, nor is it required to have any header
105   return false;
106 }
107 
108 ByteOrder ObjectFileJIT::GetByteOrder() const { return m_data.GetByteOrder(); }
109 
110 bool ObjectFileJIT::IsExecutable() const { return false; }
111 
112 uint32_t ObjectFileJIT::GetAddressByteSize() const {
113   return m_data.GetAddressByteSize();
114 }
115 
116 Symtab *ObjectFileJIT::GetSymtab() {
117   ModuleSP module_sp(GetModule());
118   if (module_sp) {
119     std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
120     if (m_symtab_up == nullptr) {
121       m_symtab_up.reset(new Symtab(this));
122       std::lock_guard<std::recursive_mutex> symtab_guard(
123           m_symtab_up->GetMutex());
124       ObjectFileJITDelegateSP delegate_sp(m_delegate_wp.lock());
125       if (delegate_sp)
126         delegate_sp->PopulateSymtab(this, *m_symtab_up);
127       // TODO: get symbols from delegate
128       m_symtab_up->Finalize();
129     }
130   }
131   return m_symtab_up.get();
132 }
133 
134 bool ObjectFileJIT::IsStripped() {
135   return false; // JIT code that is in a module is never stripped
136 }
137 
138 void ObjectFileJIT::CreateSections(SectionList &unified_section_list) {
139   if (!m_sections_up) {
140     m_sections_up.reset(new SectionList());
141     ObjectFileJITDelegateSP delegate_sp(m_delegate_wp.lock());
142     if (delegate_sp) {
143       delegate_sp->PopulateSectionList(this, *m_sections_up);
144       unified_section_list = *m_sections_up;
145     }
146   }
147 }
148 
149 void ObjectFileJIT::Dump(Stream *s) {
150   ModuleSP module_sp(GetModule());
151   if (module_sp) {
152     std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
153     s->Printf("%p: ", static_cast<void *>(this));
154     s->Indent();
155     s->PutCString("ObjectFileJIT");
156 
157     if (ArchSpec arch = GetArchitecture())
158       *s << ", arch = " << arch.GetArchitectureName();
159 
160     s->EOL();
161 
162     SectionList *sections = GetSectionList();
163     if (sections)
164       sections->Dump(s, nullptr, true, UINT32_MAX);
165 
166     if (m_symtab_up)
167       m_symtab_up->Dump(s, nullptr, eSortOrderNone);
168   }
169 }
170 
171 UUID ObjectFileJIT::GetUUID() {
172   // TODO: maybe get from delegate, not needed for first pass
173   return UUID();
174 }
175 
176 uint32_t ObjectFileJIT::GetDependentModules(FileSpecList &files) {
177   // JIT modules don't have dependencies, but they could
178   // if external functions are called and we know where they are
179   files.Clear();
180   return 0;
181 }
182 
183 lldb_private::Address ObjectFileJIT::GetEntryPointAddress() {
184   return Address();
185 }
186 
187 lldb_private::Address ObjectFileJIT::GetBaseAddress() { return Address(); }
188 
189 ObjectFile::Type ObjectFileJIT::CalculateType() { return eTypeJIT; }
190 
191 ObjectFile::Strata ObjectFileJIT::CalculateStrata() { return eStrataJIT; }
192 
193 ArchSpec ObjectFileJIT::GetArchitecture() {
194   if (ObjectFileJITDelegateSP delegate_sp = m_delegate_wp.lock())
195     return delegate_sp->GetArchitecture();
196   return ArchSpec();
197 }
198 
199 // PluginInterface protocol
200 lldb_private::ConstString ObjectFileJIT::GetPluginName() {
201   return GetPluginNameStatic();
202 }
203 
204 uint32_t ObjectFileJIT::GetPluginVersion() { return 1; }
205 
206 bool ObjectFileJIT::SetLoadAddress(Target &target, lldb::addr_t value,
207                                    bool value_is_offset) {
208   size_t num_loaded_sections = 0;
209   SectionList *section_list = GetSectionList();
210   if (section_list) {
211     const size_t num_sections = section_list->GetSize();
212     // "value" is an offset to apply to each top level segment
213     for (size_t sect_idx = 0; sect_idx < num_sections; ++sect_idx) {
214       // Iterate through the object file sections to find all of the sections
215       // that size on disk (to avoid __PAGEZERO) and load them
216       SectionSP section_sp(section_list->GetSectionAtIndex(sect_idx));
217       if (section_sp && section_sp->GetFileSize() > 0 &&
218           !section_sp->IsThreadSpecific()) {
219         if (target.GetSectionLoadList().SetSectionLoadAddress(
220                 section_sp, section_sp->GetFileAddress() + value))
221           ++num_loaded_sections;
222       }
223     }
224   }
225   return num_loaded_sections > 0;
226 }
227 
228 size_t ObjectFileJIT::ReadSectionData(lldb_private::Section *section,
229                                       lldb::offset_t section_offset, void *dst,
230                                       size_t dst_len) {
231   lldb::offset_t file_size = section->GetFileSize();
232   if (section_offset < file_size) {
233     size_t src_len = file_size - section_offset;
234     if (src_len > dst_len)
235       src_len = dst_len;
236     const uint8_t *src =
237         ((uint8_t *)(uintptr_t)section->GetFileOffset()) + section_offset;
238 
239     memcpy(dst, src, src_len);
240     return src_len;
241   }
242   return 0;
243 }
244 
245 size_t ObjectFileJIT::ReadSectionData(
246     lldb_private::Section *section,
247     lldb_private::DataExtractor &section_data) {
248   if (section->GetFileSize()) {
249     const void *src = (void *)(uintptr_t)section->GetFileOffset();
250 
251     DataBufferSP data_sp =
252         std::make_shared<DataBufferHeap>(src, section->GetFileSize());
253     section_data.SetData(data_sp, 0, data_sp->GetByteSize());
254     section_data.SetByteOrder(GetByteOrder());
255     section_data.SetAddressByteSize(GetAddressByteSize());
256     return section_data.GetByteSize();
257   }
258   section_data.Clear();
259   return 0;
260 }
261