1 //===-- SBInstruction.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 "lldb/API/SBInstruction.h"
10 
11 #include "lldb/API/SBAddress.h"
12 #include "lldb/API/SBFrame.h"
13 #include "lldb/API/SBInstruction.h"
14 #include "lldb/API/SBStream.h"
15 #include "lldb/API/SBTarget.h"
16 #include "lldb/Core/Disassembler.h"
17 #include "lldb/Core/EmulateInstruction.h"
18 #include "lldb/Core/Module.h"
19 #include "lldb/Core/StreamFile.h"
20 #include "lldb/Host/HostInfo.h"
21 #include "lldb/Target/ExecutionContext.h"
22 #include "lldb/Target/StackFrame.h"
23 #include "lldb/Target/Target.h"
24 #include "lldb/Utility/ArchSpec.h"
25 #include "lldb/Utility/DataBufferHeap.h"
26 #include "lldb/Utility/DataExtractor.h"
27 
28 //----------------------------------------------------------------------
29 // We recently fixed a leak in one of the Instruction subclasses where the
30 // instruction will only hold a weak reference to the disassembler to avoid a
31 // cycle that was keeping both objects alive (leak) and we need the
32 // InstructionImpl class to make sure our public API behaves as users would
33 // expect. Calls in our public API allow clients to do things like:
34 //
35 // 1  lldb::SBInstruction inst;
36 // 2  inst = target.ReadInstructions(pc, 1).GetInstructionAtIndex(0)
37 // 3  if (inst.DoesBranch())
38 // 4  ...
39 //
40 // There was a temporary lldb::DisassemblerSP object created in the
41 // SBInstructionList that was returned by lldb.target.ReadInstructions() that
42 // will go away after line 2 but the "inst" object should be able to still
43 // answer questions about itself. So we make sure that any SBInstruction
44 // objects that are given out have a strong reference to the disassembler and
45 // the instruction so that the object can live and successfully respond to all
46 // queries.
47 //----------------------------------------------------------------------
48 class InstructionImpl {
49 public:
50   InstructionImpl(const lldb::DisassemblerSP &disasm_sp,
51                   const lldb::InstructionSP &inst_sp)
52       : m_disasm_sp(disasm_sp), m_inst_sp(inst_sp) {}
53 
54   lldb::InstructionSP GetSP() const { return m_inst_sp; }
55 
56   bool IsValid() const { return (bool)m_inst_sp; }
57 
58 protected:
59   lldb::DisassemblerSP m_disasm_sp; // Can be empty/invalid
60   lldb::InstructionSP m_inst_sp;
61 };
62 
63 using namespace lldb;
64 using namespace lldb_private;
65 
66 SBInstruction::SBInstruction() : m_opaque_sp() {}
67 
68 SBInstruction::SBInstruction(const lldb::DisassemblerSP &disasm_sp,
69                              const lldb::InstructionSP &inst_sp)
70     : m_opaque_sp(new InstructionImpl(disasm_sp, inst_sp)) {}
71 
72 SBInstruction::SBInstruction(const SBInstruction &rhs)
73     : m_opaque_sp(rhs.m_opaque_sp) {}
74 
75 const SBInstruction &SBInstruction::operator=(const SBInstruction &rhs) {
76   if (this != &rhs)
77     m_opaque_sp = rhs.m_opaque_sp;
78   return *this;
79 }
80 
81 SBInstruction::~SBInstruction() {}
82 
83 bool SBInstruction::IsValid() { return m_opaque_sp && m_opaque_sp->IsValid(); }
84 
85 SBAddress SBInstruction::GetAddress() {
86   SBAddress sb_addr;
87   lldb::InstructionSP inst_sp(GetOpaque());
88   if (inst_sp && inst_sp->GetAddress().IsValid())
89     sb_addr.SetAddress(&inst_sp->GetAddress());
90   return sb_addr;
91 }
92 
93 const char *SBInstruction::GetMnemonic(SBTarget target) {
94   lldb::InstructionSP inst_sp(GetOpaque());
95   if (inst_sp) {
96     ExecutionContext exe_ctx;
97     TargetSP target_sp(target.GetSP());
98     std::unique_lock<std::recursive_mutex> lock;
99     if (target_sp) {
100       lock = std::unique_lock<std::recursive_mutex>(target_sp->GetAPIMutex());
101 
102       target_sp->CalculateExecutionContext(exe_ctx);
103       exe_ctx.SetProcessSP(target_sp->GetProcessSP());
104     }
105     return inst_sp->GetMnemonic(&exe_ctx);
106   }
107   return NULL;
108 }
109 
110 const char *SBInstruction::GetOperands(SBTarget target) {
111   lldb::InstructionSP inst_sp(GetOpaque());
112   if (inst_sp) {
113     ExecutionContext exe_ctx;
114     TargetSP target_sp(target.GetSP());
115     std::unique_lock<std::recursive_mutex> lock;
116     if (target_sp) {
117       lock = std::unique_lock<std::recursive_mutex>(target_sp->GetAPIMutex());
118 
119       target_sp->CalculateExecutionContext(exe_ctx);
120       exe_ctx.SetProcessSP(target_sp->GetProcessSP());
121     }
122     return inst_sp->GetOperands(&exe_ctx);
123   }
124   return NULL;
125 }
126 
127 const char *SBInstruction::GetComment(SBTarget target) {
128   lldb::InstructionSP inst_sp(GetOpaque());
129   if (inst_sp) {
130     ExecutionContext exe_ctx;
131     TargetSP target_sp(target.GetSP());
132     std::unique_lock<std::recursive_mutex> lock;
133     if (target_sp) {
134       lock = std::unique_lock<std::recursive_mutex>(target_sp->GetAPIMutex());
135 
136       target_sp->CalculateExecutionContext(exe_ctx);
137       exe_ctx.SetProcessSP(target_sp->GetProcessSP());
138     }
139     return inst_sp->GetComment(&exe_ctx);
140   }
141   return NULL;
142 }
143 
144 size_t SBInstruction::GetByteSize() {
145   lldb::InstructionSP inst_sp(GetOpaque());
146   if (inst_sp)
147     return inst_sp->GetOpcode().GetByteSize();
148   return 0;
149 }
150 
151 SBData SBInstruction::GetData(SBTarget target) {
152   lldb::SBData sb_data;
153   lldb::InstructionSP inst_sp(GetOpaque());
154   if (inst_sp) {
155     DataExtractorSP data_extractor_sp(new DataExtractor());
156     if (inst_sp->GetData(*data_extractor_sp)) {
157       sb_data.SetOpaque(data_extractor_sp);
158     }
159   }
160   return sb_data;
161 }
162 
163 bool SBInstruction::DoesBranch() {
164   lldb::InstructionSP inst_sp(GetOpaque());
165   if (inst_sp)
166     return inst_sp->DoesBranch();
167   return false;
168 }
169 
170 bool SBInstruction::HasDelaySlot() {
171   lldb::InstructionSP inst_sp(GetOpaque());
172   if (inst_sp)
173     return inst_sp->HasDelaySlot();
174   return false;
175 }
176 
177 bool SBInstruction::CanSetBreakpoint () {
178   lldb::InstructionSP inst_sp(GetOpaque());
179   if (inst_sp)
180     return inst_sp->CanSetBreakpoint();
181   return false;
182 }
183 
184 lldb::InstructionSP SBInstruction::GetOpaque() {
185   if (m_opaque_sp)
186     return m_opaque_sp->GetSP();
187   else
188     return lldb::InstructionSP();
189 }
190 
191 void SBInstruction::SetOpaque(const lldb::DisassemblerSP &disasm_sp,
192                               const lldb::InstructionSP &inst_sp) {
193   m_opaque_sp.reset(new InstructionImpl(disasm_sp, inst_sp));
194 }
195 
196 bool SBInstruction::GetDescription(lldb::SBStream &s) {
197   lldb::InstructionSP inst_sp(GetOpaque());
198   if (inst_sp) {
199     SymbolContext sc;
200     const Address &addr = inst_sp->GetAddress();
201     ModuleSP module_sp(addr.GetModule());
202     if (module_sp)
203       module_sp->ResolveSymbolContextForAddress(addr, eSymbolContextEverything,
204                                                 sc);
205     // Use the "ref()" instead of the "get()" accessor in case the SBStream
206     // didn't have a stream already created, one will get created...
207     FormatEntity::Entry format;
208     FormatEntity::Parse("${addr}: ", format);
209     inst_sp->Dump(&s.ref(), 0, true, false, NULL, &sc, NULL, &format, 0);
210     return true;
211   }
212   return false;
213 }
214 
215 void SBInstruction::Print(FILE *out) {
216   if (out == NULL)
217     return;
218 
219   lldb::InstructionSP inst_sp(GetOpaque());
220   if (inst_sp) {
221     SymbolContext sc;
222     const Address &addr = inst_sp->GetAddress();
223     ModuleSP module_sp(addr.GetModule());
224     if (module_sp)
225       module_sp->ResolveSymbolContextForAddress(addr, eSymbolContextEverything,
226                                                 sc);
227     StreamFile out_stream(out, false);
228     FormatEntity::Entry format;
229     FormatEntity::Parse("${addr}: ", format);
230     inst_sp->Dump(&out_stream, 0, true, false, NULL, &sc, NULL, &format, 0);
231   }
232 }
233 
234 bool SBInstruction::EmulateWithFrame(lldb::SBFrame &frame,
235                                      uint32_t evaluate_options) {
236   lldb::InstructionSP inst_sp(GetOpaque());
237   if (inst_sp) {
238     lldb::StackFrameSP frame_sp(frame.GetFrameSP());
239 
240     if (frame_sp) {
241       lldb_private::ExecutionContext exe_ctx;
242       frame_sp->CalculateExecutionContext(exe_ctx);
243       lldb_private::Target *target = exe_ctx.GetTargetPtr();
244       lldb_private::ArchSpec arch = target->GetArchitecture();
245 
246       return inst_sp->Emulate(
247           arch, evaluate_options, (void *)frame_sp.get(),
248           &lldb_private::EmulateInstruction::ReadMemoryFrame,
249           &lldb_private::EmulateInstruction::WriteMemoryFrame,
250           &lldb_private::EmulateInstruction::ReadRegisterFrame,
251           &lldb_private::EmulateInstruction::WriteRegisterFrame);
252     }
253   }
254   return false;
255 }
256 
257 bool SBInstruction::DumpEmulation(const char *triple) {
258   lldb::InstructionSP inst_sp(GetOpaque());
259   if (inst_sp && triple) {
260     return inst_sp->DumpEmulation(HostInfo::GetAugmentedArchSpec(triple));
261   }
262   return false;
263 }
264 
265 bool SBInstruction::TestEmulation(lldb::SBStream &output_stream,
266                                   const char *test_file) {
267   if (!m_opaque_sp)
268     SetOpaque(lldb::DisassemblerSP(),
269               lldb::InstructionSP(new PseudoInstruction()));
270 
271   lldb::InstructionSP inst_sp(GetOpaque());
272   if (inst_sp)
273     return inst_sp->TestEmulation(output_stream.get(), test_file);
274   return false;
275 }
276