1 //===-- Materializer.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/Expression/Materializer.h"
10 #include "lldb/Core/DumpDataExtractor.h"
11 #include "lldb/Core/ValueObjectConstResult.h"
12 #include "lldb/Core/ValueObjectVariable.h"
13 #include "lldb/Expression/ExpressionVariable.h"
14 #include "lldb/Symbol/ClangASTContext.h"
15 #include "lldb/Symbol/Symbol.h"
16 #include "lldb/Symbol/Type.h"
17 #include "lldb/Symbol/Variable.h"
18 #include "lldb/Target/ExecutionContext.h"
19 #include "lldb/Target/RegisterContext.h"
20 #include "lldb/Target/StackFrame.h"
21 #include "lldb/Target/Target.h"
22 #include "lldb/Target/Thread.h"
23 #include "lldb/Utility/Log.h"
24 #include "lldb/Utility/RegisterValue.h"
25 
26 using namespace lldb_private;
27 
28 uint32_t Materializer::AddStructMember(Entity &entity) {
29   uint32_t size = entity.GetSize();
30   uint32_t alignment = entity.GetAlignment();
31 
32   uint32_t ret;
33 
34   if (m_current_offset == 0)
35     m_struct_alignment = alignment;
36 
37   if (m_current_offset % alignment)
38     m_current_offset += (alignment - (m_current_offset % alignment));
39 
40   ret = m_current_offset;
41 
42   m_current_offset += size;
43 
44   return ret;
45 }
46 
47 void Materializer::Entity::SetSizeAndAlignmentFromType(CompilerType &type) {
48   if (llvm::Optional<uint64_t> size = type.GetByteSize(nullptr))
49     m_size = *size;
50 
51   uint32_t bit_alignment = type.GetTypeBitAlign();
52 
53   if (bit_alignment % 8) {
54     bit_alignment += 8;
55     bit_alignment &= ~((uint32_t)0x111u);
56   }
57 
58   m_alignment = bit_alignment / 8;
59 }
60 
61 class EntityPersistentVariable : public Materializer::Entity {
62 public:
63   EntityPersistentVariable(lldb::ExpressionVariableSP &persistent_variable_sp,
64                            Materializer::PersistentVariableDelegate *delegate)
65       : Entity(), m_persistent_variable_sp(persistent_variable_sp),
66         m_delegate(delegate) {
67     // Hard-coding to maximum size of a pointer since persistent variables are
68     // materialized by reference
69     m_size = 8;
70     m_alignment = 8;
71   }
72 
73   void MakeAllocation(IRMemoryMap &map, Status &err) {
74     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
75 
76     // Allocate a spare memory area to store the persistent variable's
77     // contents.
78 
79     Status allocate_error;
80     const bool zero_memory = false;
81 
82     lldb::addr_t mem = map.Malloc(
83         m_persistent_variable_sp->GetByteSize(), 8,
84         lldb::ePermissionsReadable | lldb::ePermissionsWritable,
85         IRMemoryMap::eAllocationPolicyMirror, zero_memory, allocate_error);
86 
87     if (!allocate_error.Success()) {
88       err.SetErrorStringWithFormat(
89           "couldn't allocate a memory area to store %s: %s",
90           m_persistent_variable_sp->GetName().GetCString(),
91           allocate_error.AsCString());
92       return;
93     }
94 
95     if (log)
96       log->Printf("Allocated %s (0x%" PRIx64 ") successfully",
97                   m_persistent_variable_sp->GetName().GetCString(), mem);
98 
99     // Put the location of the spare memory into the live data of the
100     // ValueObject.
101 
102     m_persistent_variable_sp->m_live_sp = ValueObjectConstResult::Create(
103         map.GetBestExecutionContextScope(),
104         m_persistent_variable_sp->GetCompilerType(),
105         m_persistent_variable_sp->GetName(), mem, eAddressTypeLoad,
106         map.GetAddressByteSize());
107 
108     // Clear the flag if the variable will never be deallocated.
109 
110     if (m_persistent_variable_sp->m_flags &
111         ExpressionVariable::EVKeepInTarget) {
112       Status leak_error;
113       map.Leak(mem, leak_error);
114       m_persistent_variable_sp->m_flags &=
115           ~ExpressionVariable::EVNeedsAllocation;
116     }
117 
118     // Write the contents of the variable to the area.
119 
120     Status write_error;
121 
122     map.WriteMemory(mem, m_persistent_variable_sp->GetValueBytes(),
123                     m_persistent_variable_sp->GetByteSize(), write_error);
124 
125     if (!write_error.Success()) {
126       err.SetErrorStringWithFormat(
127           "couldn't write %s to the target: %s",
128           m_persistent_variable_sp->GetName().AsCString(),
129           write_error.AsCString());
130       return;
131     }
132   }
133 
134   void DestroyAllocation(IRMemoryMap &map, Status &err) {
135     Status deallocate_error;
136 
137     map.Free((lldb::addr_t)m_persistent_variable_sp->m_live_sp->GetValue()
138                  .GetScalar()
139                  .ULongLong(),
140              deallocate_error);
141 
142     m_persistent_variable_sp->m_live_sp.reset();
143 
144     if (!deallocate_error.Success()) {
145       err.SetErrorStringWithFormat(
146           "couldn't deallocate memory for %s: %s",
147           m_persistent_variable_sp->GetName().GetCString(),
148           deallocate_error.AsCString());
149     }
150   }
151 
152   void Materialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
153                    lldb::addr_t process_address, Status &err) override {
154     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
155 
156     const lldb::addr_t load_addr = process_address + m_offset;
157 
158     if (log) {
159       log->Printf("EntityPersistentVariable::Materialize [address = 0x%" PRIx64
160                   ", m_name = %s, m_flags = 0x%hx]",
161                   (uint64_t)load_addr,
162                   m_persistent_variable_sp->GetName().AsCString(),
163                   m_persistent_variable_sp->m_flags);
164     }
165 
166     if (m_persistent_variable_sp->m_flags &
167         ExpressionVariable::EVNeedsAllocation) {
168       MakeAllocation(map, err);
169       m_persistent_variable_sp->m_flags |=
170           ExpressionVariable::EVIsLLDBAllocated;
171 
172       if (!err.Success())
173         return;
174     }
175 
176     if ((m_persistent_variable_sp->m_flags &
177              ExpressionVariable::EVIsProgramReference &&
178          m_persistent_variable_sp->m_live_sp) ||
179         m_persistent_variable_sp->m_flags &
180             ExpressionVariable::EVIsLLDBAllocated) {
181       Status write_error;
182 
183       map.WriteScalarToMemory(
184           load_addr,
185           m_persistent_variable_sp->m_live_sp->GetValue().GetScalar(),
186           map.GetAddressByteSize(), write_error);
187 
188       if (!write_error.Success()) {
189         err.SetErrorStringWithFormat(
190             "couldn't write the location of %s to memory: %s",
191             m_persistent_variable_sp->GetName().AsCString(),
192             write_error.AsCString());
193       }
194     } else {
195       err.SetErrorStringWithFormat(
196           "no materialization happened for persistent variable %s",
197           m_persistent_variable_sp->GetName().AsCString());
198       return;
199     }
200   }
201 
202   void Dematerialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
203                      lldb::addr_t process_address, lldb::addr_t frame_top,
204                      lldb::addr_t frame_bottom, Status &err) override {
205     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
206 
207     const lldb::addr_t load_addr = process_address + m_offset;
208 
209     if (log) {
210       log->Printf(
211           "EntityPersistentVariable::Dematerialize [address = 0x%" PRIx64
212           ", m_name = %s, m_flags = 0x%hx]",
213           (uint64_t)process_address + m_offset,
214           m_persistent_variable_sp->GetName().AsCString(),
215           m_persistent_variable_sp->m_flags);
216     }
217 
218     if (m_delegate) {
219       m_delegate->DidDematerialize(m_persistent_variable_sp);
220     }
221 
222     if ((m_persistent_variable_sp->m_flags &
223          ExpressionVariable::EVIsLLDBAllocated) ||
224         (m_persistent_variable_sp->m_flags &
225          ExpressionVariable::EVIsProgramReference)) {
226       if (m_persistent_variable_sp->m_flags &
227               ExpressionVariable::EVIsProgramReference &&
228           !m_persistent_variable_sp->m_live_sp) {
229         // If the reference comes from the program, then the
230         // ClangExpressionVariable's live variable data hasn't been set up yet.
231         // Do this now.
232 
233         lldb::addr_t location;
234         Status read_error;
235 
236         map.ReadPointerFromMemory(&location, load_addr, read_error);
237 
238         if (!read_error.Success()) {
239           err.SetErrorStringWithFormat(
240               "couldn't read the address of program-allocated variable %s: %s",
241               m_persistent_variable_sp->GetName().GetCString(),
242               read_error.AsCString());
243           return;
244         }
245 
246         m_persistent_variable_sp->m_live_sp = ValueObjectConstResult::Create(
247             map.GetBestExecutionContextScope(),
248             m_persistent_variable_sp.get()->GetCompilerType(),
249             m_persistent_variable_sp->GetName(), location, eAddressTypeLoad,
250             m_persistent_variable_sp->GetByteSize());
251 
252         if (frame_top != LLDB_INVALID_ADDRESS &&
253             frame_bottom != LLDB_INVALID_ADDRESS && location >= frame_bottom &&
254             location <= frame_top) {
255           // If the variable is resident in the stack frame created by the
256           // expression, then it cannot be relied upon to stay around.  We
257           // treat it as needing reallocation.
258           m_persistent_variable_sp->m_flags |=
259               ExpressionVariable::EVIsLLDBAllocated;
260           m_persistent_variable_sp->m_flags |=
261               ExpressionVariable::EVNeedsAllocation;
262           m_persistent_variable_sp->m_flags |=
263               ExpressionVariable::EVNeedsFreezeDry;
264           m_persistent_variable_sp->m_flags &=
265               ~ExpressionVariable::EVIsProgramReference;
266         }
267       }
268 
269       lldb::addr_t mem = m_persistent_variable_sp->m_live_sp->GetValue()
270                              .GetScalar()
271                              .ULongLong();
272 
273       if (!m_persistent_variable_sp->m_live_sp) {
274         err.SetErrorStringWithFormat(
275             "couldn't find the memory area used to store %s",
276             m_persistent_variable_sp->GetName().GetCString());
277         return;
278       }
279 
280       if (m_persistent_variable_sp->m_live_sp->GetValue()
281               .GetValueAddressType() != eAddressTypeLoad) {
282         err.SetErrorStringWithFormat(
283             "the address of the memory area for %s is in an incorrect format",
284             m_persistent_variable_sp->GetName().GetCString());
285         return;
286       }
287 
288       if (m_persistent_variable_sp->m_flags &
289               ExpressionVariable::EVNeedsFreezeDry ||
290           m_persistent_variable_sp->m_flags &
291               ExpressionVariable::EVKeepInTarget) {
292         if (log)
293           log->Printf(
294               "Dematerializing %s from 0x%" PRIx64 " (size = %llu)",
295               m_persistent_variable_sp->GetName().GetCString(), (uint64_t)mem,
296               (unsigned long long)m_persistent_variable_sp->GetByteSize());
297 
298         // Read the contents of the spare memory area
299 
300         m_persistent_variable_sp->ValueUpdated();
301 
302         Status read_error;
303 
304         map.ReadMemory(m_persistent_variable_sp->GetValueBytes(), mem,
305                        m_persistent_variable_sp->GetByteSize(), read_error);
306 
307         if (!read_error.Success()) {
308           err.SetErrorStringWithFormat(
309               "couldn't read the contents of %s from memory: %s",
310               m_persistent_variable_sp->GetName().GetCString(),
311               read_error.AsCString());
312           return;
313         }
314 
315         m_persistent_variable_sp->m_flags &=
316             ~ExpressionVariable::EVNeedsFreezeDry;
317       }
318     } else {
319       err.SetErrorStringWithFormat(
320           "no dematerialization happened for persistent variable %s",
321           m_persistent_variable_sp->GetName().AsCString());
322       return;
323     }
324 
325     lldb::ProcessSP process_sp =
326         map.GetBestExecutionContextScope()->CalculateProcess();
327     if (!process_sp || !process_sp->CanJIT()) {
328       // Allocations are not persistent so persistent variables cannot stay
329       // materialized.
330 
331       m_persistent_variable_sp->m_flags |=
332           ExpressionVariable::EVNeedsAllocation;
333 
334       DestroyAllocation(map, err);
335       if (!err.Success())
336         return;
337     } else if (m_persistent_variable_sp->m_flags &
338                    ExpressionVariable::EVNeedsAllocation &&
339                !(m_persistent_variable_sp->m_flags &
340                  ExpressionVariable::EVKeepInTarget)) {
341       DestroyAllocation(map, err);
342       if (!err.Success())
343         return;
344     }
345   }
346 
347   void DumpToLog(IRMemoryMap &map, lldb::addr_t process_address,
348                  Log *log) override {
349     StreamString dump_stream;
350 
351     Status err;
352 
353     const lldb::addr_t load_addr = process_address + m_offset;
354 
355     dump_stream.Printf("0x%" PRIx64 ": EntityPersistentVariable (%s)\n",
356                        load_addr,
357                        m_persistent_variable_sp->GetName().AsCString());
358 
359     {
360       dump_stream.Printf("Pointer:\n");
361 
362       DataBufferHeap data(m_size, 0);
363 
364       map.ReadMemory(data.GetBytes(), load_addr, m_size, err);
365 
366       if (!err.Success()) {
367         dump_stream.Printf("  <could not be read>\n");
368       } else {
369         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
370                      load_addr);
371 
372         dump_stream.PutChar('\n');
373       }
374     }
375 
376     {
377       dump_stream.Printf("Target:\n");
378 
379       lldb::addr_t target_address;
380 
381       map.ReadPointerFromMemory(&target_address, load_addr, err);
382 
383       if (!err.Success()) {
384         dump_stream.Printf("  <could not be read>\n");
385       } else {
386         DataBufferHeap data(m_persistent_variable_sp->GetByteSize(), 0);
387 
388         map.ReadMemory(data.GetBytes(), target_address,
389                        m_persistent_variable_sp->GetByteSize(), err);
390 
391         if (!err.Success()) {
392           dump_stream.Printf("  <could not be read>\n");
393         } else {
394           DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
395                        target_address);
396 
397           dump_stream.PutChar('\n');
398         }
399       }
400     }
401 
402     log->PutString(dump_stream.GetString());
403   }
404 
405   void Wipe(IRMemoryMap &map, lldb::addr_t process_address) override {}
406 
407 private:
408   lldb::ExpressionVariableSP m_persistent_variable_sp;
409   Materializer::PersistentVariableDelegate *m_delegate;
410 };
411 
412 uint32_t Materializer::AddPersistentVariable(
413     lldb::ExpressionVariableSP &persistent_variable_sp,
414     PersistentVariableDelegate *delegate, Status &err) {
415   EntityVector::iterator iter = m_entities.insert(m_entities.end(), EntityUP());
416   iter->reset(new EntityPersistentVariable(persistent_variable_sp, delegate));
417   uint32_t ret = AddStructMember(**iter);
418   (*iter)->SetOffset(ret);
419   return ret;
420 }
421 
422 class EntityVariable : public Materializer::Entity {
423 public:
424   EntityVariable(lldb::VariableSP &variable_sp)
425       : Entity(), m_variable_sp(variable_sp), m_is_reference(false),
426         m_temporary_allocation(LLDB_INVALID_ADDRESS),
427         m_temporary_allocation_size(0) {
428     // Hard-coding to maximum size of a pointer since all variables are
429     // materialized by reference
430     m_size = 8;
431     m_alignment = 8;
432     m_is_reference =
433         m_variable_sp->GetType()->GetForwardCompilerType().IsReferenceType();
434   }
435 
436   void Materialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
437                    lldb::addr_t process_address, Status &err) override {
438     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
439 
440     const lldb::addr_t load_addr = process_address + m_offset;
441     if (log) {
442       log->Printf("EntityVariable::Materialize [address = 0x%" PRIx64
443                   ", m_variable_sp = %s]",
444                   (uint64_t)load_addr, m_variable_sp->GetName().AsCString());
445     }
446 
447     ExecutionContextScope *scope = frame_sp.get();
448 
449     if (!scope)
450       scope = map.GetBestExecutionContextScope();
451 
452     lldb::ValueObjectSP valobj_sp =
453         ValueObjectVariable::Create(scope, m_variable_sp);
454 
455     if (!valobj_sp) {
456       err.SetErrorStringWithFormat(
457           "couldn't get a value object for variable %s",
458           m_variable_sp->GetName().AsCString());
459       return;
460     }
461 
462     Status valobj_error = valobj_sp->GetError();
463 
464     if (valobj_error.Fail()) {
465       err.SetErrorStringWithFormat("couldn't get the value of variable %s: %s",
466                                    m_variable_sp->GetName().AsCString(),
467                                    valobj_error.AsCString());
468       return;
469     }
470 
471     if (m_is_reference) {
472       DataExtractor valobj_extractor;
473       Status extract_error;
474       valobj_sp->GetData(valobj_extractor, extract_error);
475 
476       if (!extract_error.Success()) {
477         err.SetErrorStringWithFormat(
478             "couldn't read contents of reference variable %s: %s",
479             m_variable_sp->GetName().AsCString(), extract_error.AsCString());
480         return;
481       }
482 
483       lldb::offset_t offset = 0;
484       lldb::addr_t reference_addr = valobj_extractor.GetAddress(&offset);
485 
486       Status write_error;
487       map.WritePointerToMemory(load_addr, reference_addr, write_error);
488 
489       if (!write_error.Success()) {
490         err.SetErrorStringWithFormat("couldn't write the contents of reference "
491                                      "variable %s to memory: %s",
492                                      m_variable_sp->GetName().AsCString(),
493                                      write_error.AsCString());
494         return;
495       }
496     } else {
497       AddressType address_type = eAddressTypeInvalid;
498       const bool scalar_is_load_address = false;
499       lldb::addr_t addr_of_valobj =
500           valobj_sp->GetAddressOf(scalar_is_load_address, &address_type);
501       if (addr_of_valobj != LLDB_INVALID_ADDRESS) {
502         Status write_error;
503         map.WritePointerToMemory(load_addr, addr_of_valobj, write_error);
504 
505         if (!write_error.Success()) {
506           err.SetErrorStringWithFormat(
507               "couldn't write the address of variable %s to memory: %s",
508               m_variable_sp->GetName().AsCString(), write_error.AsCString());
509           return;
510         }
511       } else {
512         DataExtractor data;
513         Status extract_error;
514         valobj_sp->GetData(data, extract_error);
515         if (!extract_error.Success()) {
516           err.SetErrorStringWithFormat("couldn't get the value of %s: %s",
517                                        m_variable_sp->GetName().AsCString(),
518                                        extract_error.AsCString());
519           return;
520         }
521 
522         if (m_temporary_allocation != LLDB_INVALID_ADDRESS) {
523           err.SetErrorStringWithFormat(
524               "trying to create a temporary region for %s but one exists",
525               m_variable_sp->GetName().AsCString());
526           return;
527         }
528 
529         if (data.GetByteSize() < m_variable_sp->GetType()->GetByteSize()) {
530           if (data.GetByteSize() == 0 &&
531               !m_variable_sp->LocationExpression().IsValid()) {
532             err.SetErrorStringWithFormat("the variable '%s' has no location, "
533                                          "it may have been optimized out",
534                                          m_variable_sp->GetName().AsCString());
535           } else {
536             err.SetErrorStringWithFormat(
537                 "size of variable %s (%" PRIu64
538                 ") is larger than the ValueObject's size (%" PRIu64 ")",
539                 m_variable_sp->GetName().AsCString(),
540                 m_variable_sp->GetType()->GetByteSize(), data.GetByteSize());
541           }
542           return;
543         }
544 
545         size_t bit_align =
546             m_variable_sp->GetType()->GetLayoutCompilerType().GetTypeBitAlign();
547         size_t byte_align = (bit_align + 7) / 8;
548 
549         if (!byte_align)
550           byte_align = 1;
551 
552         Status alloc_error;
553         const bool zero_memory = false;
554 
555         m_temporary_allocation = map.Malloc(
556             data.GetByteSize(), byte_align,
557             lldb::ePermissionsReadable | lldb::ePermissionsWritable,
558             IRMemoryMap::eAllocationPolicyMirror, zero_memory, alloc_error);
559 
560         m_temporary_allocation_size = data.GetByteSize();
561 
562         m_original_data.reset(
563             new DataBufferHeap(data.GetDataStart(), data.GetByteSize()));
564 
565         if (!alloc_error.Success()) {
566           err.SetErrorStringWithFormat(
567               "couldn't allocate a temporary region for %s: %s",
568               m_variable_sp->GetName().AsCString(), alloc_error.AsCString());
569           return;
570         }
571 
572         Status write_error;
573 
574         map.WriteMemory(m_temporary_allocation, data.GetDataStart(),
575                         data.GetByteSize(), write_error);
576 
577         if (!write_error.Success()) {
578           err.SetErrorStringWithFormat(
579               "couldn't write to the temporary region for %s: %s",
580               m_variable_sp->GetName().AsCString(), write_error.AsCString());
581           return;
582         }
583 
584         Status pointer_write_error;
585 
586         map.WritePointerToMemory(load_addr, m_temporary_allocation,
587                                  pointer_write_error);
588 
589         if (!pointer_write_error.Success()) {
590           err.SetErrorStringWithFormat(
591               "couldn't write the address of the temporary region for %s: %s",
592               m_variable_sp->GetName().AsCString(),
593               pointer_write_error.AsCString());
594         }
595       }
596     }
597   }
598 
599   void Dematerialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
600                      lldb::addr_t process_address, lldb::addr_t frame_top,
601                      lldb::addr_t frame_bottom, Status &err) override {
602     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
603 
604     const lldb::addr_t load_addr = process_address + m_offset;
605     if (log) {
606       log->Printf("EntityVariable::Dematerialize [address = 0x%" PRIx64
607                   ", m_variable_sp = %s]",
608                   (uint64_t)load_addr, m_variable_sp->GetName().AsCString());
609     }
610 
611     if (m_temporary_allocation != LLDB_INVALID_ADDRESS) {
612       ExecutionContextScope *scope = frame_sp.get();
613 
614       if (!scope)
615         scope = map.GetBestExecutionContextScope();
616 
617       lldb::ValueObjectSP valobj_sp =
618           ValueObjectVariable::Create(scope, m_variable_sp);
619 
620       if (!valobj_sp) {
621         err.SetErrorStringWithFormat(
622             "couldn't get a value object for variable %s",
623             m_variable_sp->GetName().AsCString());
624         return;
625       }
626 
627       lldb_private::DataExtractor data;
628 
629       Status extract_error;
630 
631       map.GetMemoryData(data, m_temporary_allocation, valobj_sp->GetByteSize(),
632                         extract_error);
633 
634       if (!extract_error.Success()) {
635         err.SetErrorStringWithFormat("couldn't get the data for variable %s",
636                                      m_variable_sp->GetName().AsCString());
637         return;
638       }
639 
640       bool actually_write = true;
641 
642       if (m_original_data) {
643         if ((data.GetByteSize() == m_original_data->GetByteSize()) &&
644             !memcmp(m_original_data->GetBytes(), data.GetDataStart(),
645                     data.GetByteSize())) {
646           actually_write = false;
647         }
648       }
649 
650       Status set_error;
651 
652       if (actually_write) {
653         valobj_sp->SetData(data, set_error);
654 
655         if (!set_error.Success()) {
656           err.SetErrorStringWithFormat(
657               "couldn't write the new contents of %s back into the variable",
658               m_variable_sp->GetName().AsCString());
659           return;
660         }
661       }
662 
663       Status free_error;
664 
665       map.Free(m_temporary_allocation, free_error);
666 
667       if (!free_error.Success()) {
668         err.SetErrorStringWithFormat(
669             "couldn't free the temporary region for %s: %s",
670             m_variable_sp->GetName().AsCString(), free_error.AsCString());
671         return;
672       }
673 
674       m_original_data.reset();
675       m_temporary_allocation = LLDB_INVALID_ADDRESS;
676       m_temporary_allocation_size = 0;
677     }
678   }
679 
680   void DumpToLog(IRMemoryMap &map, lldb::addr_t process_address,
681                  Log *log) override {
682     StreamString dump_stream;
683 
684     const lldb::addr_t load_addr = process_address + m_offset;
685     dump_stream.Printf("0x%" PRIx64 ": EntityVariable\n", load_addr);
686 
687     Status err;
688 
689     lldb::addr_t ptr = LLDB_INVALID_ADDRESS;
690 
691     {
692       dump_stream.Printf("Pointer:\n");
693 
694       DataBufferHeap data(m_size, 0);
695 
696       map.ReadMemory(data.GetBytes(), load_addr, m_size, err);
697 
698       if (!err.Success()) {
699         dump_stream.Printf("  <could not be read>\n");
700       } else {
701         DataExtractor extractor(data.GetBytes(), data.GetByteSize(),
702                                 map.GetByteOrder(), map.GetAddressByteSize());
703 
704         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
705                      load_addr);
706 
707         lldb::offset_t offset;
708 
709         ptr = extractor.GetPointer(&offset);
710 
711         dump_stream.PutChar('\n');
712       }
713     }
714 
715     if (m_temporary_allocation == LLDB_INVALID_ADDRESS) {
716       dump_stream.Printf("Points to process memory:\n");
717     } else {
718       dump_stream.Printf("Temporary allocation:\n");
719     }
720 
721     if (ptr == LLDB_INVALID_ADDRESS) {
722       dump_stream.Printf("  <could not be be found>\n");
723     } else {
724       DataBufferHeap data(m_temporary_allocation_size, 0);
725 
726       map.ReadMemory(data.GetBytes(), m_temporary_allocation,
727                      m_temporary_allocation_size, err);
728 
729       if (!err.Success()) {
730         dump_stream.Printf("  <could not be read>\n");
731       } else {
732         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
733                      load_addr);
734 
735         dump_stream.PutChar('\n');
736       }
737     }
738 
739     log->PutString(dump_stream.GetString());
740   }
741 
742   void Wipe(IRMemoryMap &map, lldb::addr_t process_address) override {
743     if (m_temporary_allocation != LLDB_INVALID_ADDRESS) {
744       Status free_error;
745 
746       map.Free(m_temporary_allocation, free_error);
747 
748       m_temporary_allocation = LLDB_INVALID_ADDRESS;
749       m_temporary_allocation_size = 0;
750     }
751   }
752 
753 private:
754   lldb::VariableSP m_variable_sp;
755   bool m_is_reference;
756   lldb::addr_t m_temporary_allocation;
757   size_t m_temporary_allocation_size;
758   lldb::DataBufferSP m_original_data;
759 };
760 
761 uint32_t Materializer::AddVariable(lldb::VariableSP &variable_sp, Status &err) {
762   EntityVector::iterator iter = m_entities.insert(m_entities.end(), EntityUP());
763   iter->reset(new EntityVariable(variable_sp));
764   uint32_t ret = AddStructMember(**iter);
765   (*iter)->SetOffset(ret);
766   return ret;
767 }
768 
769 class EntityResultVariable : public Materializer::Entity {
770 public:
771   EntityResultVariable(const CompilerType &type, bool is_program_reference,
772                        bool keep_in_memory,
773                        Materializer::PersistentVariableDelegate *delegate)
774       : Entity(), m_type(type), m_is_program_reference(is_program_reference),
775         m_keep_in_memory(keep_in_memory),
776         m_temporary_allocation(LLDB_INVALID_ADDRESS),
777         m_temporary_allocation_size(0), m_delegate(delegate) {
778     // Hard-coding to maximum size of a pointer since all results are
779     // materialized by reference
780     m_size = 8;
781     m_alignment = 8;
782   }
783 
784   void Materialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
785                    lldb::addr_t process_address, Status &err) override {
786     if (!m_is_program_reference) {
787       if (m_temporary_allocation != LLDB_INVALID_ADDRESS) {
788         err.SetErrorString("Trying to create a temporary region for the result "
789                            "but one exists");
790         return;
791       }
792 
793       const lldb::addr_t load_addr = process_address + m_offset;
794 
795       ExecutionContextScope *exe_scope = map.GetBestExecutionContextScope();
796 
797       llvm::Optional<uint64_t> byte_size = m_type.GetByteSize(exe_scope);
798       if (!byte_size) {
799         err.SetErrorString("can't get size of type");
800         return;
801       }
802       size_t bit_align = m_type.GetTypeBitAlign();
803       size_t byte_align = (bit_align + 7) / 8;
804 
805       if (!byte_align)
806         byte_align = 1;
807 
808       Status alloc_error;
809       const bool zero_memory = true;
810 
811       m_temporary_allocation = map.Malloc(
812           *byte_size, byte_align,
813           lldb::ePermissionsReadable | lldb::ePermissionsWritable,
814           IRMemoryMap::eAllocationPolicyMirror, zero_memory, alloc_error);
815       m_temporary_allocation_size = *byte_size;
816 
817       if (!alloc_error.Success()) {
818         err.SetErrorStringWithFormat(
819             "couldn't allocate a temporary region for the result: %s",
820             alloc_error.AsCString());
821         return;
822       }
823 
824       Status pointer_write_error;
825 
826       map.WritePointerToMemory(load_addr, m_temporary_allocation,
827                                pointer_write_error);
828 
829       if (!pointer_write_error.Success()) {
830         err.SetErrorStringWithFormat("couldn't write the address of the "
831                                      "temporary region for the result: %s",
832                                      pointer_write_error.AsCString());
833       }
834     }
835   }
836 
837   void Dematerialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
838                      lldb::addr_t process_address, lldb::addr_t frame_top,
839                      lldb::addr_t frame_bottom, Status &err) override {
840     err.Clear();
841 
842     ExecutionContextScope *exe_scope = map.GetBestExecutionContextScope();
843 
844     if (!exe_scope) {
845       err.SetErrorString("Couldn't dematerialize a result variable: invalid "
846                          "execution context scope");
847       return;
848     }
849 
850     lldb::addr_t address;
851     Status read_error;
852     const lldb::addr_t load_addr = process_address + m_offset;
853 
854     map.ReadPointerFromMemory(&address, load_addr, read_error);
855 
856     if (!read_error.Success()) {
857       err.SetErrorString("Couldn't dematerialize a result variable: couldn't "
858                          "read its address");
859       return;
860     }
861 
862     lldb::TargetSP target_sp = exe_scope->CalculateTarget();
863 
864     if (!target_sp) {
865       err.SetErrorString("Couldn't dematerialize a result variable: no target");
866       return;
867     }
868 
869     Status type_system_error;
870     TypeSystem *type_system = target_sp->GetScratchTypeSystemForLanguage(
871         &type_system_error, m_type.GetMinimumLanguage());
872 
873     if (!type_system) {
874       err.SetErrorStringWithFormat("Couldn't dematerialize a result variable: "
875                                    "couldn't get the corresponding type "
876                                    "system: %s",
877                                    type_system_error.AsCString());
878       return;
879     }
880 
881     PersistentExpressionState *persistent_state =
882         type_system->GetPersistentExpressionState();
883 
884     if (!persistent_state) {
885       err.SetErrorString("Couldn't dematerialize a result variable: "
886                          "corresponding type system doesn't handle persistent "
887                          "variables");
888       return;
889     }
890 
891     ConstString name =
892         m_delegate
893             ? m_delegate->GetName()
894             : persistent_state->GetNextPersistentVariableName(
895                   *target_sp, persistent_state->GetPersistentVariablePrefix());
896 
897     lldb::ExpressionVariableSP ret = persistent_state->CreatePersistentVariable(
898         exe_scope, name, m_type, map.GetByteOrder(), map.GetAddressByteSize());
899 
900     if (!ret) {
901       err.SetErrorStringWithFormat("couldn't dematerialize a result variable: "
902                                    "failed to make persistent variable %s",
903                                    name.AsCString());
904       return;
905     }
906 
907     lldb::ProcessSP process_sp =
908         map.GetBestExecutionContextScope()->CalculateProcess();
909 
910     if (m_delegate) {
911       m_delegate->DidDematerialize(ret);
912     }
913 
914     bool can_persist =
915         (m_is_program_reference && process_sp && process_sp->CanJIT() &&
916          !(address >= frame_bottom && address < frame_top));
917 
918     if (can_persist && m_keep_in_memory) {
919       ret->m_live_sp = ValueObjectConstResult::Create(exe_scope, m_type, name,
920                                                       address, eAddressTypeLoad,
921                                                       map.GetAddressByteSize());
922     }
923 
924     ret->ValueUpdated();
925 
926     const size_t pvar_byte_size = ret->GetByteSize();
927     uint8_t *pvar_data = ret->GetValueBytes();
928 
929     map.ReadMemory(pvar_data, address, pvar_byte_size, read_error);
930 
931     if (!read_error.Success()) {
932       err.SetErrorString(
933           "Couldn't dematerialize a result variable: couldn't read its memory");
934       return;
935     }
936 
937     if (!can_persist || !m_keep_in_memory) {
938       ret->m_flags |= ExpressionVariable::EVNeedsAllocation;
939 
940       if (m_temporary_allocation != LLDB_INVALID_ADDRESS) {
941         Status free_error;
942         map.Free(m_temporary_allocation, free_error);
943       }
944     } else {
945       ret->m_flags |= ExpressionVariable::EVIsLLDBAllocated;
946     }
947 
948     m_temporary_allocation = LLDB_INVALID_ADDRESS;
949     m_temporary_allocation_size = 0;
950   }
951 
952   void DumpToLog(IRMemoryMap &map, lldb::addr_t process_address,
953                  Log *log) override {
954     StreamString dump_stream;
955 
956     const lldb::addr_t load_addr = process_address + m_offset;
957 
958     dump_stream.Printf("0x%" PRIx64 ": EntityResultVariable\n", load_addr);
959 
960     Status err;
961 
962     lldb::addr_t ptr = LLDB_INVALID_ADDRESS;
963 
964     {
965       dump_stream.Printf("Pointer:\n");
966 
967       DataBufferHeap data(m_size, 0);
968 
969       map.ReadMemory(data.GetBytes(), load_addr, m_size, err);
970 
971       if (!err.Success()) {
972         dump_stream.Printf("  <could not be read>\n");
973       } else {
974         DataExtractor extractor(data.GetBytes(), data.GetByteSize(),
975                                 map.GetByteOrder(), map.GetAddressByteSize());
976 
977         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
978                      load_addr);
979 
980         lldb::offset_t offset;
981 
982         ptr = extractor.GetPointer(&offset);
983 
984         dump_stream.PutChar('\n');
985       }
986     }
987 
988     if (m_temporary_allocation == LLDB_INVALID_ADDRESS) {
989       dump_stream.Printf("Points to process memory:\n");
990     } else {
991       dump_stream.Printf("Temporary allocation:\n");
992     }
993 
994     if (ptr == LLDB_INVALID_ADDRESS) {
995       dump_stream.Printf("  <could not be be found>\n");
996     } else {
997       DataBufferHeap data(m_temporary_allocation_size, 0);
998 
999       map.ReadMemory(data.GetBytes(), m_temporary_allocation,
1000                      m_temporary_allocation_size, err);
1001 
1002       if (!err.Success()) {
1003         dump_stream.Printf("  <could not be read>\n");
1004       } else {
1005         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
1006                      load_addr);
1007 
1008         dump_stream.PutChar('\n');
1009       }
1010     }
1011 
1012     log->PutString(dump_stream.GetString());
1013   }
1014 
1015   void Wipe(IRMemoryMap &map, lldb::addr_t process_address) override {
1016     if (!m_keep_in_memory && m_temporary_allocation != LLDB_INVALID_ADDRESS) {
1017       Status free_error;
1018 
1019       map.Free(m_temporary_allocation, free_error);
1020     }
1021 
1022     m_temporary_allocation = LLDB_INVALID_ADDRESS;
1023     m_temporary_allocation_size = 0;
1024   }
1025 
1026 private:
1027   CompilerType m_type;
1028   bool m_is_program_reference;
1029   bool m_keep_in_memory;
1030 
1031   lldb::addr_t m_temporary_allocation;
1032   size_t m_temporary_allocation_size;
1033   Materializer::PersistentVariableDelegate *m_delegate;
1034 };
1035 
1036 uint32_t Materializer::AddResultVariable(const CompilerType &type,
1037                                          bool is_program_reference,
1038                                          bool keep_in_memory,
1039                                          PersistentVariableDelegate *delegate,
1040                                          Status &err) {
1041   EntityVector::iterator iter = m_entities.insert(m_entities.end(), EntityUP());
1042   iter->reset(new EntityResultVariable(type, is_program_reference,
1043                                        keep_in_memory, delegate));
1044   uint32_t ret = AddStructMember(**iter);
1045   (*iter)->SetOffset(ret);
1046   return ret;
1047 }
1048 
1049 class EntitySymbol : public Materializer::Entity {
1050 public:
1051   EntitySymbol(const Symbol &symbol) : Entity(), m_symbol(symbol) {
1052     // Hard-coding to maximum size of a symbol
1053     m_size = 8;
1054     m_alignment = 8;
1055   }
1056 
1057   void Materialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
1058                    lldb::addr_t process_address, Status &err) override {
1059     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1060 
1061     const lldb::addr_t load_addr = process_address + m_offset;
1062 
1063     if (log) {
1064       log->Printf("EntitySymbol::Materialize [address = 0x%" PRIx64
1065                   ", m_symbol = %s]",
1066                   (uint64_t)load_addr, m_symbol.GetName().AsCString());
1067     }
1068 
1069     const Address sym_address = m_symbol.GetAddress();
1070 
1071     ExecutionContextScope *exe_scope = map.GetBestExecutionContextScope();
1072 
1073     lldb::TargetSP target_sp;
1074 
1075     if (exe_scope)
1076       target_sp = map.GetBestExecutionContextScope()->CalculateTarget();
1077 
1078     if (!target_sp) {
1079       err.SetErrorStringWithFormat(
1080           "couldn't resolve symbol %s because there is no target",
1081           m_symbol.GetName().AsCString());
1082       return;
1083     }
1084 
1085     lldb::addr_t resolved_address = sym_address.GetLoadAddress(target_sp.get());
1086 
1087     if (resolved_address == LLDB_INVALID_ADDRESS)
1088       resolved_address = sym_address.GetFileAddress();
1089 
1090     Status pointer_write_error;
1091 
1092     map.WritePointerToMemory(load_addr, resolved_address, pointer_write_error);
1093 
1094     if (!pointer_write_error.Success()) {
1095       err.SetErrorStringWithFormat(
1096           "couldn't write the address of symbol %s: %s",
1097           m_symbol.GetName().AsCString(), pointer_write_error.AsCString());
1098       return;
1099     }
1100   }
1101 
1102   void Dematerialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
1103                      lldb::addr_t process_address, lldb::addr_t frame_top,
1104                      lldb::addr_t frame_bottom, Status &err) override {
1105     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1106 
1107     const lldb::addr_t load_addr = process_address + m_offset;
1108 
1109     if (log) {
1110       log->Printf("EntitySymbol::Dematerialize [address = 0x%" PRIx64
1111                   ", m_symbol = %s]",
1112                   (uint64_t)load_addr, m_symbol.GetName().AsCString());
1113     }
1114 
1115     // no work needs to be done
1116   }
1117 
1118   void DumpToLog(IRMemoryMap &map, lldb::addr_t process_address,
1119                  Log *log) override {
1120     StreamString dump_stream;
1121 
1122     Status err;
1123 
1124     const lldb::addr_t load_addr = process_address + m_offset;
1125 
1126     dump_stream.Printf("0x%" PRIx64 ": EntitySymbol (%s)\n", load_addr,
1127                        m_symbol.GetName().AsCString());
1128 
1129     {
1130       dump_stream.Printf("Pointer:\n");
1131 
1132       DataBufferHeap data(m_size, 0);
1133 
1134       map.ReadMemory(data.GetBytes(), load_addr, m_size, err);
1135 
1136       if (!err.Success()) {
1137         dump_stream.Printf("  <could not be read>\n");
1138       } else {
1139         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
1140                      load_addr);
1141 
1142         dump_stream.PutChar('\n');
1143       }
1144     }
1145 
1146     log->PutString(dump_stream.GetString());
1147   }
1148 
1149   void Wipe(IRMemoryMap &map, lldb::addr_t process_address) override {}
1150 
1151 private:
1152   Symbol m_symbol;
1153 };
1154 
1155 uint32_t Materializer::AddSymbol(const Symbol &symbol_sp, Status &err) {
1156   EntityVector::iterator iter = m_entities.insert(m_entities.end(), EntityUP());
1157   iter->reset(new EntitySymbol(symbol_sp));
1158   uint32_t ret = AddStructMember(**iter);
1159   (*iter)->SetOffset(ret);
1160   return ret;
1161 }
1162 
1163 class EntityRegister : public Materializer::Entity {
1164 public:
1165   EntityRegister(const RegisterInfo &register_info)
1166       : Entity(), m_register_info(register_info) {
1167     // Hard-coding alignment conservatively
1168     m_size = m_register_info.byte_size;
1169     m_alignment = m_register_info.byte_size;
1170   }
1171 
1172   void Materialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
1173                    lldb::addr_t process_address, Status &err) override {
1174     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1175 
1176     const lldb::addr_t load_addr = process_address + m_offset;
1177 
1178     if (log) {
1179       log->Printf("EntityRegister::Materialize [address = 0x%" PRIx64
1180                   ", m_register_info = %s]",
1181                   (uint64_t)load_addr, m_register_info.name);
1182     }
1183 
1184     RegisterValue reg_value;
1185 
1186     if (!frame_sp.get()) {
1187       err.SetErrorStringWithFormat(
1188           "couldn't materialize register %s without a stack frame",
1189           m_register_info.name);
1190       return;
1191     }
1192 
1193     lldb::RegisterContextSP reg_context_sp = frame_sp->GetRegisterContext();
1194 
1195     if (!reg_context_sp->ReadRegister(&m_register_info, reg_value)) {
1196       err.SetErrorStringWithFormat("couldn't read the value of register %s",
1197                                    m_register_info.name);
1198       return;
1199     }
1200 
1201     DataExtractor register_data;
1202 
1203     if (!reg_value.GetData(register_data)) {
1204       err.SetErrorStringWithFormat("couldn't get the data for register %s",
1205                                    m_register_info.name);
1206       return;
1207     }
1208 
1209     if (register_data.GetByteSize() != m_register_info.byte_size) {
1210       err.SetErrorStringWithFormat(
1211           "data for register %s had size %llu but we expected %llu",
1212           m_register_info.name, (unsigned long long)register_data.GetByteSize(),
1213           (unsigned long long)m_register_info.byte_size);
1214       return;
1215     }
1216 
1217     m_register_contents.reset(new DataBufferHeap(register_data.GetDataStart(),
1218                                                  register_data.GetByteSize()));
1219 
1220     Status write_error;
1221 
1222     map.WriteMemory(load_addr, register_data.GetDataStart(),
1223                     register_data.GetByteSize(), write_error);
1224 
1225     if (!write_error.Success()) {
1226       err.SetErrorStringWithFormat(
1227           "couldn't write the contents of register %s: %s",
1228           m_register_info.name, write_error.AsCString());
1229       return;
1230     }
1231   }
1232 
1233   void Dematerialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
1234                      lldb::addr_t process_address, lldb::addr_t frame_top,
1235                      lldb::addr_t frame_bottom, Status &err) override {
1236     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1237 
1238     const lldb::addr_t load_addr = process_address + m_offset;
1239 
1240     if (log) {
1241       log->Printf("EntityRegister::Dematerialize [address = 0x%" PRIx64
1242                   ", m_register_info = %s]",
1243                   (uint64_t)load_addr, m_register_info.name);
1244     }
1245 
1246     Status extract_error;
1247 
1248     DataExtractor register_data;
1249 
1250     if (!frame_sp.get()) {
1251       err.SetErrorStringWithFormat(
1252           "couldn't dematerialize register %s without a stack frame",
1253           m_register_info.name);
1254       return;
1255     }
1256 
1257     lldb::RegisterContextSP reg_context_sp = frame_sp->GetRegisterContext();
1258 
1259     map.GetMemoryData(register_data, load_addr, m_register_info.byte_size,
1260                       extract_error);
1261 
1262     if (!extract_error.Success()) {
1263       err.SetErrorStringWithFormat("couldn't get the data for register %s: %s",
1264                                    m_register_info.name,
1265                                    extract_error.AsCString());
1266       return;
1267     }
1268 
1269     if (!memcmp(register_data.GetDataStart(), m_register_contents->GetBytes(),
1270                 register_data.GetByteSize())) {
1271       // No write required, and in particular we avoid errors if the register
1272       // wasn't writable
1273 
1274       m_register_contents.reset();
1275       return;
1276     }
1277 
1278     m_register_contents.reset();
1279 
1280     RegisterValue register_value(
1281         const_cast<uint8_t *>(register_data.GetDataStart()),
1282         register_data.GetByteSize(), register_data.GetByteOrder());
1283 
1284     if (!reg_context_sp->WriteRegister(&m_register_info, register_value)) {
1285       err.SetErrorStringWithFormat("couldn't write the value of register %s",
1286                                    m_register_info.name);
1287       return;
1288     }
1289   }
1290 
1291   void DumpToLog(IRMemoryMap &map, lldb::addr_t process_address,
1292                  Log *log) override {
1293     StreamString dump_stream;
1294 
1295     Status err;
1296 
1297     const lldb::addr_t load_addr = process_address + m_offset;
1298 
1299     dump_stream.Printf("0x%" PRIx64 ": EntityRegister (%s)\n", load_addr,
1300                        m_register_info.name);
1301 
1302     {
1303       dump_stream.Printf("Value:\n");
1304 
1305       DataBufferHeap data(m_size, 0);
1306 
1307       map.ReadMemory(data.GetBytes(), load_addr, m_size, err);
1308 
1309       if (!err.Success()) {
1310         dump_stream.Printf("  <could not be read>\n");
1311       } else {
1312         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
1313                      load_addr);
1314 
1315         dump_stream.PutChar('\n');
1316       }
1317     }
1318 
1319     log->PutString(dump_stream.GetString());
1320   }
1321 
1322   void Wipe(IRMemoryMap &map, lldb::addr_t process_address) override {}
1323 
1324 private:
1325   RegisterInfo m_register_info;
1326   lldb::DataBufferSP m_register_contents;
1327 };
1328 
1329 uint32_t Materializer::AddRegister(const RegisterInfo &register_info,
1330                                    Status &err) {
1331   EntityVector::iterator iter = m_entities.insert(m_entities.end(), EntityUP());
1332   iter->reset(new EntityRegister(register_info));
1333   uint32_t ret = AddStructMember(**iter);
1334   (*iter)->SetOffset(ret);
1335   return ret;
1336 }
1337 
1338 Materializer::Materializer()
1339     : m_dematerializer_wp(), m_current_offset(0), m_struct_alignment(8) {}
1340 
1341 Materializer::~Materializer() {
1342   DematerializerSP dematerializer_sp = m_dematerializer_wp.lock();
1343 
1344   if (dematerializer_sp)
1345     dematerializer_sp->Wipe();
1346 }
1347 
1348 Materializer::DematerializerSP
1349 Materializer::Materialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
1350                           lldb::addr_t process_address, Status &error) {
1351   ExecutionContextScope *exe_scope = frame_sp.get();
1352 
1353   if (!exe_scope)
1354     exe_scope = map.GetBestExecutionContextScope();
1355 
1356   DematerializerSP dematerializer_sp = m_dematerializer_wp.lock();
1357 
1358   if (dematerializer_sp) {
1359     error.SetErrorToGenericError();
1360     error.SetErrorString("Couldn't materialize: already materialized");
1361   }
1362 
1363   DematerializerSP ret(
1364       new Dematerializer(*this, frame_sp, map, process_address));
1365 
1366   if (!exe_scope) {
1367     error.SetErrorToGenericError();
1368     error.SetErrorString("Couldn't materialize: target doesn't exist");
1369   }
1370 
1371   for (EntityUP &entity_up : m_entities) {
1372     entity_up->Materialize(frame_sp, map, process_address, error);
1373 
1374     if (!error.Success())
1375       return DematerializerSP();
1376   }
1377 
1378   if (Log *log =
1379           lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS)) {
1380     log->Printf(
1381         "Materializer::Materialize (frame_sp = %p, process_address = 0x%" PRIx64
1382         ") materialized:",
1383         static_cast<void *>(frame_sp.get()), process_address);
1384     for (EntityUP &entity_up : m_entities)
1385       entity_up->DumpToLog(map, process_address, log);
1386   }
1387 
1388   m_dematerializer_wp = ret;
1389 
1390   return ret;
1391 }
1392 
1393 void Materializer::Dematerializer::Dematerialize(Status &error,
1394                                                  lldb::addr_t frame_bottom,
1395                                                  lldb::addr_t frame_top) {
1396   lldb::StackFrameSP frame_sp;
1397 
1398   lldb::ThreadSP thread_sp = m_thread_wp.lock();
1399   if (thread_sp)
1400     frame_sp = thread_sp->GetFrameWithStackID(m_stack_id);
1401 
1402   ExecutionContextScope *exe_scope = m_map->GetBestExecutionContextScope();
1403 
1404   if (!IsValid()) {
1405     error.SetErrorToGenericError();
1406     error.SetErrorString("Couldn't dematerialize: invalid dematerializer");
1407   }
1408 
1409   if (!exe_scope) {
1410     error.SetErrorToGenericError();
1411     error.SetErrorString("Couldn't dematerialize: target is gone");
1412   } else {
1413     if (Log *log =
1414             lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS)) {
1415       log->Printf("Materializer::Dematerialize (frame_sp = %p, process_address "
1416                   "= 0x%" PRIx64 ") about to dematerialize:",
1417                   static_cast<void *>(frame_sp.get()), m_process_address);
1418       for (EntityUP &entity_up : m_materializer->m_entities)
1419         entity_up->DumpToLog(*m_map, m_process_address, log);
1420     }
1421 
1422     for (EntityUP &entity_up : m_materializer->m_entities) {
1423       entity_up->Dematerialize(frame_sp, *m_map, m_process_address, frame_top,
1424                                frame_bottom, error);
1425 
1426       if (!error.Success())
1427         break;
1428     }
1429   }
1430 
1431   Wipe();
1432 }
1433 
1434 void Materializer::Dematerializer::Wipe() {
1435   if (!IsValid())
1436     return;
1437 
1438   for (EntityUP &entity_up : m_materializer->m_entities) {
1439     entity_up->Wipe(*m_map, m_process_address);
1440   }
1441 
1442   m_materializer = nullptr;
1443   m_map = nullptr;
1444   m_process_address = LLDB_INVALID_ADDRESS;
1445 }
1446 
1447 Materializer::PersistentVariableDelegate::~PersistentVariableDelegate() =
1448     default;
1449