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 #include "SBReproducerPrivate.h"
11 
12 #include "lldb/API/SBAddress.h"
13 #include "lldb/API/SBFrame.h"
14 
15 #include "lldb/API/SBInstruction.h"
16 #include "lldb/API/SBStream.h"
17 #include "lldb/API/SBTarget.h"
18 #include "lldb/Core/Disassembler.h"
19 #include "lldb/Core/EmulateInstruction.h"
20 #include "lldb/Core/Module.h"
21 #include "lldb/Core/StreamFile.h"
22 #include "lldb/Host/HostInfo.h"
23 #include "lldb/Target/ExecutionContext.h"
24 #include "lldb/Target/StackFrame.h"
25 #include "lldb/Target/Target.h"
26 #include "lldb/Utility/ArchSpec.h"
27 #include "lldb/Utility/DataBufferHeap.h"
28 #include "lldb/Utility/DataExtractor.h"
29 
30 #include <memory>
31 
32 // We recently fixed a leak in one of the Instruction subclasses where the
33 // instruction will only hold a weak reference to the disassembler to avoid a
34 // cycle that was keeping both objects alive (leak) and we need the
35 // InstructionImpl class to make sure our public API behaves as users would
36 // expect. Calls in our public API allow clients to do things like:
37 //
38 // 1  lldb::SBInstruction inst;
39 // 2  inst = target.ReadInstructions(pc, 1).GetInstructionAtIndex(0)
40 // 3  if (inst.DoesBranch())
41 // 4  ...
42 //
43 // There was a temporary lldb::DisassemblerSP object created in the
44 // SBInstructionList that was returned by lldb.target.ReadInstructions() that
45 // will go away after line 2 but the "inst" object should be able to still
46 // answer questions about itself. So we make sure that any SBInstruction
47 // objects that are given out have a strong reference to the disassembler and
48 // the instruction so that the object can live and successfully respond to all
49 // queries.
50 class InstructionImpl {
51 public:
52   InstructionImpl(const lldb::DisassemblerSP &disasm_sp,
53                   const lldb::InstructionSP &inst_sp)
54       : m_disasm_sp(disasm_sp), m_inst_sp(inst_sp) {}
55 
56   lldb::InstructionSP GetSP() const { return m_inst_sp; }
57 
58   bool IsValid() const { return (bool)m_inst_sp; }
59 
60 protected:
61   lldb::DisassemblerSP m_disasm_sp; // Can be empty/invalid
62   lldb::InstructionSP m_inst_sp;
63 };
64 
65 using namespace lldb;
66 using namespace lldb_private;
67 
68 SBInstruction::SBInstruction() : m_opaque_sp() {
69   LLDB_RECORD_CONSTRUCTOR_NO_ARGS(SBInstruction);
70 }
71 
72 SBInstruction::SBInstruction(const lldb::DisassemblerSP &disasm_sp,
73                              const lldb::InstructionSP &inst_sp)
74     : m_opaque_sp(new InstructionImpl(disasm_sp, inst_sp)) {}
75 
76 SBInstruction::SBInstruction(const SBInstruction &rhs)
77     : m_opaque_sp(rhs.m_opaque_sp) {
78   LLDB_RECORD_CONSTRUCTOR(SBInstruction, (const lldb::SBInstruction &), rhs);
79 }
80 
81 const SBInstruction &SBInstruction::operator=(const SBInstruction &rhs) {
82   LLDB_RECORD_METHOD(const lldb::SBInstruction &,
83                      SBInstruction, operator=,(const lldb::SBInstruction &),
84                      rhs);
85 
86   if (this != &rhs)
87     m_opaque_sp = rhs.m_opaque_sp;
88   return LLDB_RECORD_RESULT(*this);
89 }
90 
91 SBInstruction::~SBInstruction() {}
92 
93 bool SBInstruction::IsValid() {
94   LLDB_RECORD_METHOD_NO_ARGS(bool, SBInstruction, IsValid);
95   return this->operator bool();
96 }
97 SBInstruction::operator bool() const {
98   LLDB_RECORD_METHOD_CONST_NO_ARGS(bool, SBInstruction, operator bool);
99 
100   return m_opaque_sp && m_opaque_sp->IsValid();
101 }
102 
103 SBAddress SBInstruction::GetAddress() {
104   LLDB_RECORD_METHOD_NO_ARGS(lldb::SBAddress, SBInstruction, GetAddress);
105 
106   SBAddress sb_addr;
107   lldb::InstructionSP inst_sp(GetOpaque());
108   if (inst_sp && inst_sp->GetAddress().IsValid())
109     sb_addr.SetAddress(&inst_sp->GetAddress());
110   return LLDB_RECORD_RESULT(sb_addr);
111 }
112 
113 const char *SBInstruction::GetMnemonic(SBTarget target) {
114   LLDB_RECORD_METHOD(const char *, SBInstruction, GetMnemonic, (lldb::SBTarget),
115                      target);
116 
117   lldb::InstructionSP inst_sp(GetOpaque());
118   if (inst_sp) {
119     ExecutionContext exe_ctx;
120     TargetSP target_sp(target.GetSP());
121     std::unique_lock<std::recursive_mutex> lock;
122     if (target_sp) {
123       lock = std::unique_lock<std::recursive_mutex>(target_sp->GetAPIMutex());
124 
125       target_sp->CalculateExecutionContext(exe_ctx);
126       exe_ctx.SetProcessSP(target_sp->GetProcessSP());
127     }
128     return inst_sp->GetMnemonic(&exe_ctx);
129   }
130   return nullptr;
131 }
132 
133 const char *SBInstruction::GetOperands(SBTarget target) {
134   LLDB_RECORD_METHOD(const char *, SBInstruction, GetOperands, (lldb::SBTarget),
135                      target);
136 
137   lldb::InstructionSP inst_sp(GetOpaque());
138   if (inst_sp) {
139     ExecutionContext exe_ctx;
140     TargetSP target_sp(target.GetSP());
141     std::unique_lock<std::recursive_mutex> lock;
142     if (target_sp) {
143       lock = std::unique_lock<std::recursive_mutex>(target_sp->GetAPIMutex());
144 
145       target_sp->CalculateExecutionContext(exe_ctx);
146       exe_ctx.SetProcessSP(target_sp->GetProcessSP());
147     }
148     return inst_sp->GetOperands(&exe_ctx);
149   }
150   return nullptr;
151 }
152 
153 const char *SBInstruction::GetComment(SBTarget target) {
154   LLDB_RECORD_METHOD(const char *, SBInstruction, GetComment, (lldb::SBTarget),
155                      target);
156 
157   lldb::InstructionSP inst_sp(GetOpaque());
158   if (inst_sp) {
159     ExecutionContext exe_ctx;
160     TargetSP target_sp(target.GetSP());
161     std::unique_lock<std::recursive_mutex> lock;
162     if (target_sp) {
163       lock = std::unique_lock<std::recursive_mutex>(target_sp->GetAPIMutex());
164 
165       target_sp->CalculateExecutionContext(exe_ctx);
166       exe_ctx.SetProcessSP(target_sp->GetProcessSP());
167     }
168     return inst_sp->GetComment(&exe_ctx);
169   }
170   return nullptr;
171 }
172 
173 size_t SBInstruction::GetByteSize() {
174   LLDB_RECORD_METHOD_NO_ARGS(size_t, SBInstruction, GetByteSize);
175 
176   lldb::InstructionSP inst_sp(GetOpaque());
177   if (inst_sp)
178     return inst_sp->GetOpcode().GetByteSize();
179   return 0;
180 }
181 
182 SBData SBInstruction::GetData(SBTarget target) {
183   LLDB_RECORD_METHOD(lldb::SBData, SBInstruction, GetData, (lldb::SBTarget),
184                      target);
185 
186   lldb::SBData sb_data;
187   lldb::InstructionSP inst_sp(GetOpaque());
188   if (inst_sp) {
189     DataExtractorSP data_extractor_sp(new DataExtractor());
190     if (inst_sp->GetData(*data_extractor_sp)) {
191       sb_data.SetOpaque(data_extractor_sp);
192     }
193   }
194   return LLDB_RECORD_RESULT(sb_data);
195 }
196 
197 bool SBInstruction::DoesBranch() {
198   LLDB_RECORD_METHOD_NO_ARGS(bool, SBInstruction, DoesBranch);
199 
200   lldb::InstructionSP inst_sp(GetOpaque());
201   if (inst_sp)
202     return inst_sp->DoesBranch();
203   return false;
204 }
205 
206 bool SBInstruction::HasDelaySlot() {
207   LLDB_RECORD_METHOD_NO_ARGS(bool, SBInstruction, HasDelaySlot);
208 
209   lldb::InstructionSP inst_sp(GetOpaque());
210   if (inst_sp)
211     return inst_sp->HasDelaySlot();
212   return false;
213 }
214 
215 bool SBInstruction::CanSetBreakpoint() {
216   LLDB_RECORD_METHOD_NO_ARGS(bool, SBInstruction, CanSetBreakpoint);
217 
218   lldb::InstructionSP inst_sp(GetOpaque());
219   if (inst_sp)
220     return inst_sp->CanSetBreakpoint();
221   return false;
222 }
223 
224 lldb::InstructionSP SBInstruction::GetOpaque() {
225   if (m_opaque_sp)
226     return m_opaque_sp->GetSP();
227   else
228     return lldb::InstructionSP();
229 }
230 
231 void SBInstruction::SetOpaque(const lldb::DisassemblerSP &disasm_sp,
232                               const lldb::InstructionSP &inst_sp) {
233   m_opaque_sp = std::make_shared<InstructionImpl>(disasm_sp, inst_sp);
234 }
235 
236 bool SBInstruction::GetDescription(lldb::SBStream &s) {
237   LLDB_RECORD_METHOD(bool, SBInstruction, GetDescription, (lldb::SBStream &),
238                      s);
239 
240   lldb::InstructionSP inst_sp(GetOpaque());
241   if (inst_sp) {
242     SymbolContext sc;
243     const Address &addr = inst_sp->GetAddress();
244     ModuleSP module_sp(addr.GetModule());
245     if (module_sp)
246       module_sp->ResolveSymbolContextForAddress(addr, eSymbolContextEverything,
247                                                 sc);
248     // Use the "ref()" instead of the "get()" accessor in case the SBStream
249     // didn't have a stream already created, one will get created...
250     FormatEntity::Entry format;
251     FormatEntity::Parse("${addr}: ", format);
252     inst_sp->Dump(&s.ref(), 0, true, false, nullptr, &sc, nullptr, &format, 0);
253     return true;
254   }
255   return false;
256 }
257 
258 void SBInstruction::Print(FILE *out) {
259   LLDB_RECORD_METHOD(void, SBInstruction, Print, (FILE *), out);
260 
261   if (out == nullptr)
262     return;
263 
264   lldb::InstructionSP inst_sp(GetOpaque());
265   if (inst_sp) {
266     SymbolContext sc;
267     const Address &addr = inst_sp->GetAddress();
268     ModuleSP module_sp(addr.GetModule());
269     if (module_sp)
270       module_sp->ResolveSymbolContextForAddress(addr, eSymbolContextEverything,
271                                                 sc);
272     StreamFile out_stream(out, false);
273     FormatEntity::Entry format;
274     FormatEntity::Parse("${addr}: ", format);
275     inst_sp->Dump(&out_stream, 0, true, false, nullptr, &sc, nullptr, &format,
276                   0);
277   }
278 }
279 
280 bool SBInstruction::EmulateWithFrame(lldb::SBFrame &frame,
281                                      uint32_t evaluate_options) {
282   LLDB_RECORD_METHOD(bool, SBInstruction, EmulateWithFrame,
283                      (lldb::SBFrame &, uint32_t), frame, evaluate_options);
284 
285   lldb::InstructionSP inst_sp(GetOpaque());
286   if (inst_sp) {
287     lldb::StackFrameSP frame_sp(frame.GetFrameSP());
288 
289     if (frame_sp) {
290       lldb_private::ExecutionContext exe_ctx;
291       frame_sp->CalculateExecutionContext(exe_ctx);
292       lldb_private::Target *target = exe_ctx.GetTargetPtr();
293       lldb_private::ArchSpec arch = target->GetArchitecture();
294 
295       return inst_sp->Emulate(
296           arch, evaluate_options, (void *)frame_sp.get(),
297           &lldb_private::EmulateInstruction::ReadMemoryFrame,
298           &lldb_private::EmulateInstruction::WriteMemoryFrame,
299           &lldb_private::EmulateInstruction::ReadRegisterFrame,
300           &lldb_private::EmulateInstruction::WriteRegisterFrame);
301     }
302   }
303   return false;
304 }
305 
306 bool SBInstruction::DumpEmulation(const char *triple) {
307   LLDB_RECORD_METHOD(bool, SBInstruction, DumpEmulation, (const char *),
308                      triple);
309 
310   lldb::InstructionSP inst_sp(GetOpaque());
311   if (inst_sp && triple) {
312     return inst_sp->DumpEmulation(HostInfo::GetAugmentedArchSpec(triple));
313   }
314   return false;
315 }
316 
317 bool SBInstruction::TestEmulation(lldb::SBStream &output_stream,
318                                   const char *test_file) {
319   LLDB_RECORD_METHOD(bool, SBInstruction, TestEmulation,
320                      (lldb::SBStream &, const char *), output_stream,
321                      test_file);
322 
323   if (!m_opaque_sp)
324     SetOpaque(lldb::DisassemblerSP(),
325               lldb::InstructionSP(new PseudoInstruction()));
326 
327   lldb::InstructionSP inst_sp(GetOpaque());
328   if (inst_sp)
329     return inst_sp->TestEmulation(output_stream.get(), test_file);
330   return false;
331 }
332 
333 namespace lldb_private {
334 namespace repro {
335 
336 template <>
337 void RegisterMethods<SBInstruction>(Registry &R) {
338   LLDB_REGISTER_CONSTRUCTOR(SBInstruction, ());
339   LLDB_REGISTER_CONSTRUCTOR(SBInstruction, (const lldb::SBInstruction &));
340   LLDB_REGISTER_METHOD(
341       const lldb::SBInstruction &,
342       SBInstruction, operator=,(const lldb::SBInstruction &));
343   LLDB_REGISTER_METHOD(bool, SBInstruction, IsValid, ());
344   LLDB_REGISTER_METHOD_CONST(bool, SBInstruction, operator bool, ());
345   LLDB_REGISTER_METHOD(lldb::SBAddress, SBInstruction, GetAddress, ());
346   LLDB_REGISTER_METHOD(const char *, SBInstruction, GetMnemonic,
347                        (lldb::SBTarget));
348   LLDB_REGISTER_METHOD(const char *, SBInstruction, GetOperands,
349                        (lldb::SBTarget));
350   LLDB_REGISTER_METHOD(const char *, SBInstruction, GetComment,
351                        (lldb::SBTarget));
352   LLDB_REGISTER_METHOD(size_t, SBInstruction, GetByteSize, ());
353   LLDB_REGISTER_METHOD(lldb::SBData, SBInstruction, GetData,
354                        (lldb::SBTarget));
355   LLDB_REGISTER_METHOD(bool, SBInstruction, DoesBranch, ());
356   LLDB_REGISTER_METHOD(bool, SBInstruction, HasDelaySlot, ());
357   LLDB_REGISTER_METHOD(bool, SBInstruction, CanSetBreakpoint, ());
358   LLDB_REGISTER_METHOD(bool, SBInstruction, GetDescription,
359                        (lldb::SBStream &));
360   LLDB_REGISTER_METHOD(void, SBInstruction, Print, (FILE *));
361   LLDB_REGISTER_METHOD(bool, SBInstruction, EmulateWithFrame,
362                        (lldb::SBFrame &, uint32_t));
363   LLDB_REGISTER_METHOD(bool, SBInstruction, DumpEmulation, (const char *));
364   LLDB_REGISTER_METHOD(bool, SBInstruction, TestEmulation,
365                        (lldb::SBStream &, const char *));
366 }
367 
368 }
369 }
370