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().getValueOr(0),
541                 data.GetByteSize());
542           }
543           return;
544         }
545 
546         size_t bit_align =
547             m_variable_sp->GetType()->GetLayoutCompilerType().GetTypeBitAlign();
548         size_t byte_align = (bit_align + 7) / 8;
549 
550         if (!byte_align)
551           byte_align = 1;
552 
553         Status alloc_error;
554         const bool zero_memory = false;
555 
556         m_temporary_allocation = map.Malloc(
557             data.GetByteSize(), byte_align,
558             lldb::ePermissionsReadable | lldb::ePermissionsWritable,
559             IRMemoryMap::eAllocationPolicyMirror, zero_memory, alloc_error);
560 
561         m_temporary_allocation_size = data.GetByteSize();
562 
563         m_original_data.reset(
564             new DataBufferHeap(data.GetDataStart(), data.GetByteSize()));
565 
566         if (!alloc_error.Success()) {
567           err.SetErrorStringWithFormat(
568               "couldn't allocate a temporary region for %s: %s",
569               m_variable_sp->GetName().AsCString(), alloc_error.AsCString());
570           return;
571         }
572 
573         Status write_error;
574 
575         map.WriteMemory(m_temporary_allocation, data.GetDataStart(),
576                         data.GetByteSize(), write_error);
577 
578         if (!write_error.Success()) {
579           err.SetErrorStringWithFormat(
580               "couldn't write to the temporary region for %s: %s",
581               m_variable_sp->GetName().AsCString(), write_error.AsCString());
582           return;
583         }
584 
585         Status pointer_write_error;
586 
587         map.WritePointerToMemory(load_addr, m_temporary_allocation,
588                                  pointer_write_error);
589 
590         if (!pointer_write_error.Success()) {
591           err.SetErrorStringWithFormat(
592               "couldn't write the address of the temporary region for %s: %s",
593               m_variable_sp->GetName().AsCString(),
594               pointer_write_error.AsCString());
595         }
596       }
597     }
598   }
599 
600   void Dematerialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
601                      lldb::addr_t process_address, lldb::addr_t frame_top,
602                      lldb::addr_t frame_bottom, Status &err) override {
603     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
604 
605     const lldb::addr_t load_addr = process_address + m_offset;
606     if (log) {
607       log->Printf("EntityVariable::Dematerialize [address = 0x%" PRIx64
608                   ", m_variable_sp = %s]",
609                   (uint64_t)load_addr, m_variable_sp->GetName().AsCString());
610     }
611 
612     if (m_temporary_allocation != LLDB_INVALID_ADDRESS) {
613       ExecutionContextScope *scope = frame_sp.get();
614 
615       if (!scope)
616         scope = map.GetBestExecutionContextScope();
617 
618       lldb::ValueObjectSP valobj_sp =
619           ValueObjectVariable::Create(scope, m_variable_sp);
620 
621       if (!valobj_sp) {
622         err.SetErrorStringWithFormat(
623             "couldn't get a value object for variable %s",
624             m_variable_sp->GetName().AsCString());
625         return;
626       }
627 
628       lldb_private::DataExtractor data;
629 
630       Status extract_error;
631 
632       map.GetMemoryData(data, m_temporary_allocation, valobj_sp->GetByteSize(),
633                         extract_error);
634 
635       if (!extract_error.Success()) {
636         err.SetErrorStringWithFormat("couldn't get the data for variable %s",
637                                      m_variable_sp->GetName().AsCString());
638         return;
639       }
640 
641       bool actually_write = true;
642 
643       if (m_original_data) {
644         if ((data.GetByteSize() == m_original_data->GetByteSize()) &&
645             !memcmp(m_original_data->GetBytes(), data.GetDataStart(),
646                     data.GetByteSize())) {
647           actually_write = false;
648         }
649       }
650 
651       Status set_error;
652 
653       if (actually_write) {
654         valobj_sp->SetData(data, set_error);
655 
656         if (!set_error.Success()) {
657           err.SetErrorStringWithFormat(
658               "couldn't write the new contents of %s back into the variable",
659               m_variable_sp->GetName().AsCString());
660           return;
661         }
662       }
663 
664       Status free_error;
665 
666       map.Free(m_temporary_allocation, free_error);
667 
668       if (!free_error.Success()) {
669         err.SetErrorStringWithFormat(
670             "couldn't free the temporary region for %s: %s",
671             m_variable_sp->GetName().AsCString(), free_error.AsCString());
672         return;
673       }
674 
675       m_original_data.reset();
676       m_temporary_allocation = LLDB_INVALID_ADDRESS;
677       m_temporary_allocation_size = 0;
678     }
679   }
680 
681   void DumpToLog(IRMemoryMap &map, lldb::addr_t process_address,
682                  Log *log) override {
683     StreamString dump_stream;
684 
685     const lldb::addr_t load_addr = process_address + m_offset;
686     dump_stream.Printf("0x%" PRIx64 ": EntityVariable\n", load_addr);
687 
688     Status err;
689 
690     lldb::addr_t ptr = LLDB_INVALID_ADDRESS;
691 
692     {
693       dump_stream.Printf("Pointer:\n");
694 
695       DataBufferHeap data(m_size, 0);
696 
697       map.ReadMemory(data.GetBytes(), load_addr, m_size, err);
698 
699       if (!err.Success()) {
700         dump_stream.Printf("  <could not be read>\n");
701       } else {
702         DataExtractor extractor(data.GetBytes(), data.GetByteSize(),
703                                 map.GetByteOrder(), map.GetAddressByteSize());
704 
705         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
706                      load_addr);
707 
708         lldb::offset_t offset;
709 
710         ptr = extractor.GetPointer(&offset);
711 
712         dump_stream.PutChar('\n');
713       }
714     }
715 
716     if (m_temporary_allocation == LLDB_INVALID_ADDRESS) {
717       dump_stream.Printf("Points to process memory:\n");
718     } else {
719       dump_stream.Printf("Temporary allocation:\n");
720     }
721 
722     if (ptr == LLDB_INVALID_ADDRESS) {
723       dump_stream.Printf("  <could not be be found>\n");
724     } else {
725       DataBufferHeap data(m_temporary_allocation_size, 0);
726 
727       map.ReadMemory(data.GetBytes(), m_temporary_allocation,
728                      m_temporary_allocation_size, err);
729 
730       if (!err.Success()) {
731         dump_stream.Printf("  <could not be read>\n");
732       } else {
733         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
734                      load_addr);
735 
736         dump_stream.PutChar('\n');
737       }
738     }
739 
740     log->PutString(dump_stream.GetString());
741   }
742 
743   void Wipe(IRMemoryMap &map, lldb::addr_t process_address) override {
744     if (m_temporary_allocation != LLDB_INVALID_ADDRESS) {
745       Status free_error;
746 
747       map.Free(m_temporary_allocation, free_error);
748 
749       m_temporary_allocation = LLDB_INVALID_ADDRESS;
750       m_temporary_allocation_size = 0;
751     }
752   }
753 
754 private:
755   lldb::VariableSP m_variable_sp;
756   bool m_is_reference;
757   lldb::addr_t m_temporary_allocation;
758   size_t m_temporary_allocation_size;
759   lldb::DataBufferSP m_original_data;
760 };
761 
762 uint32_t Materializer::AddVariable(lldb::VariableSP &variable_sp, Status &err) {
763   EntityVector::iterator iter = m_entities.insert(m_entities.end(), EntityUP());
764   iter->reset(new EntityVariable(variable_sp));
765   uint32_t ret = AddStructMember(**iter);
766   (*iter)->SetOffset(ret);
767   return ret;
768 }
769 
770 class EntityResultVariable : public Materializer::Entity {
771 public:
772   EntityResultVariable(const CompilerType &type, bool is_program_reference,
773                        bool keep_in_memory,
774                        Materializer::PersistentVariableDelegate *delegate)
775       : Entity(), m_type(type), m_is_program_reference(is_program_reference),
776         m_keep_in_memory(keep_in_memory),
777         m_temporary_allocation(LLDB_INVALID_ADDRESS),
778         m_temporary_allocation_size(0), m_delegate(delegate) {
779     // Hard-coding to maximum size of a pointer since all results are
780     // materialized by reference
781     m_size = 8;
782     m_alignment = 8;
783   }
784 
785   void Materialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
786                    lldb::addr_t process_address, Status &err) override {
787     if (!m_is_program_reference) {
788       if (m_temporary_allocation != LLDB_INVALID_ADDRESS) {
789         err.SetErrorString("Trying to create a temporary region for the result "
790                            "but one exists");
791         return;
792       }
793 
794       const lldb::addr_t load_addr = process_address + m_offset;
795 
796       ExecutionContextScope *exe_scope = map.GetBestExecutionContextScope();
797 
798       llvm::Optional<uint64_t> byte_size = m_type.GetByteSize(exe_scope);
799       if (!byte_size) {
800         err.SetErrorString("can't get size of type");
801         return;
802       }
803       size_t bit_align = m_type.GetTypeBitAlign();
804       size_t byte_align = (bit_align + 7) / 8;
805 
806       if (!byte_align)
807         byte_align = 1;
808 
809       Status alloc_error;
810       const bool zero_memory = true;
811 
812       m_temporary_allocation = map.Malloc(
813           *byte_size, byte_align,
814           lldb::ePermissionsReadable | lldb::ePermissionsWritable,
815           IRMemoryMap::eAllocationPolicyMirror, zero_memory, alloc_error);
816       m_temporary_allocation_size = *byte_size;
817 
818       if (!alloc_error.Success()) {
819         err.SetErrorStringWithFormat(
820             "couldn't allocate a temporary region for the result: %s",
821             alloc_error.AsCString());
822         return;
823       }
824 
825       Status pointer_write_error;
826 
827       map.WritePointerToMemory(load_addr, m_temporary_allocation,
828                                pointer_write_error);
829 
830       if (!pointer_write_error.Success()) {
831         err.SetErrorStringWithFormat("couldn't write the address of the "
832                                      "temporary region for the result: %s",
833                                      pointer_write_error.AsCString());
834       }
835     }
836   }
837 
838   void Dematerialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
839                      lldb::addr_t process_address, lldb::addr_t frame_top,
840                      lldb::addr_t frame_bottom, Status &err) override {
841     err.Clear();
842 
843     ExecutionContextScope *exe_scope = map.GetBestExecutionContextScope();
844 
845     if (!exe_scope) {
846       err.SetErrorString("Couldn't dematerialize a result variable: invalid "
847                          "execution context scope");
848       return;
849     }
850 
851     lldb::addr_t address;
852     Status read_error;
853     const lldb::addr_t load_addr = process_address + m_offset;
854 
855     map.ReadPointerFromMemory(&address, load_addr, read_error);
856 
857     if (!read_error.Success()) {
858       err.SetErrorString("Couldn't dematerialize a result variable: couldn't "
859                          "read its address");
860       return;
861     }
862 
863     lldb::TargetSP target_sp = exe_scope->CalculateTarget();
864 
865     if (!target_sp) {
866       err.SetErrorString("Couldn't dematerialize a result variable: no target");
867       return;
868     }
869 
870     Status type_system_error;
871     TypeSystem *type_system = target_sp->GetScratchTypeSystemForLanguage(
872         &type_system_error, m_type.GetMinimumLanguage());
873 
874     if (!type_system) {
875       err.SetErrorStringWithFormat("Couldn't dematerialize a result variable: "
876                                    "couldn't get the corresponding type "
877                                    "system: %s",
878                                    type_system_error.AsCString());
879       return;
880     }
881 
882     PersistentExpressionState *persistent_state =
883         type_system->GetPersistentExpressionState();
884 
885     if (!persistent_state) {
886       err.SetErrorString("Couldn't dematerialize a result variable: "
887                          "corresponding type system doesn't handle persistent "
888                          "variables");
889       return;
890     }
891 
892     ConstString name =
893         m_delegate
894             ? m_delegate->GetName()
895             : persistent_state->GetNextPersistentVariableName(
896                   *target_sp, persistent_state->GetPersistentVariablePrefix());
897 
898     lldb::ExpressionVariableSP ret = persistent_state->CreatePersistentVariable(
899         exe_scope, name, m_type, map.GetByteOrder(), map.GetAddressByteSize());
900 
901     if (!ret) {
902       err.SetErrorStringWithFormat("couldn't dematerialize a result variable: "
903                                    "failed to make persistent variable %s",
904                                    name.AsCString());
905       return;
906     }
907 
908     lldb::ProcessSP process_sp =
909         map.GetBestExecutionContextScope()->CalculateProcess();
910 
911     if (m_delegate) {
912       m_delegate->DidDematerialize(ret);
913     }
914 
915     bool can_persist =
916         (m_is_program_reference && process_sp && process_sp->CanJIT() &&
917          !(address >= frame_bottom && address < frame_top));
918 
919     if (can_persist && m_keep_in_memory) {
920       ret->m_live_sp = ValueObjectConstResult::Create(exe_scope, m_type, name,
921                                                       address, eAddressTypeLoad,
922                                                       map.GetAddressByteSize());
923     }
924 
925     ret->ValueUpdated();
926 
927     const size_t pvar_byte_size = ret->GetByteSize();
928     uint8_t *pvar_data = ret->GetValueBytes();
929 
930     map.ReadMemory(pvar_data, address, pvar_byte_size, read_error);
931 
932     if (!read_error.Success()) {
933       err.SetErrorString(
934           "Couldn't dematerialize a result variable: couldn't read its memory");
935       return;
936     }
937 
938     if (!can_persist || !m_keep_in_memory) {
939       ret->m_flags |= ExpressionVariable::EVNeedsAllocation;
940 
941       if (m_temporary_allocation != LLDB_INVALID_ADDRESS) {
942         Status free_error;
943         map.Free(m_temporary_allocation, free_error);
944       }
945     } else {
946       ret->m_flags |= ExpressionVariable::EVIsLLDBAllocated;
947     }
948 
949     m_temporary_allocation = LLDB_INVALID_ADDRESS;
950     m_temporary_allocation_size = 0;
951   }
952 
953   void DumpToLog(IRMemoryMap &map, lldb::addr_t process_address,
954                  Log *log) override {
955     StreamString dump_stream;
956 
957     const lldb::addr_t load_addr = process_address + m_offset;
958 
959     dump_stream.Printf("0x%" PRIx64 ": EntityResultVariable\n", load_addr);
960 
961     Status err;
962 
963     lldb::addr_t ptr = LLDB_INVALID_ADDRESS;
964 
965     {
966       dump_stream.Printf("Pointer:\n");
967 
968       DataBufferHeap data(m_size, 0);
969 
970       map.ReadMemory(data.GetBytes(), load_addr, m_size, err);
971 
972       if (!err.Success()) {
973         dump_stream.Printf("  <could not be read>\n");
974       } else {
975         DataExtractor extractor(data.GetBytes(), data.GetByteSize(),
976                                 map.GetByteOrder(), map.GetAddressByteSize());
977 
978         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
979                      load_addr);
980 
981         lldb::offset_t offset;
982 
983         ptr = extractor.GetPointer(&offset);
984 
985         dump_stream.PutChar('\n');
986       }
987     }
988 
989     if (m_temporary_allocation == LLDB_INVALID_ADDRESS) {
990       dump_stream.Printf("Points to process memory:\n");
991     } else {
992       dump_stream.Printf("Temporary allocation:\n");
993     }
994 
995     if (ptr == LLDB_INVALID_ADDRESS) {
996       dump_stream.Printf("  <could not be be found>\n");
997     } else {
998       DataBufferHeap data(m_temporary_allocation_size, 0);
999 
1000       map.ReadMemory(data.GetBytes(), m_temporary_allocation,
1001                      m_temporary_allocation_size, err);
1002 
1003       if (!err.Success()) {
1004         dump_stream.Printf("  <could not be read>\n");
1005       } else {
1006         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
1007                      load_addr);
1008 
1009         dump_stream.PutChar('\n');
1010       }
1011     }
1012 
1013     log->PutString(dump_stream.GetString());
1014   }
1015 
1016   void Wipe(IRMemoryMap &map, lldb::addr_t process_address) override {
1017     if (!m_keep_in_memory && m_temporary_allocation != LLDB_INVALID_ADDRESS) {
1018       Status free_error;
1019 
1020       map.Free(m_temporary_allocation, free_error);
1021     }
1022 
1023     m_temporary_allocation = LLDB_INVALID_ADDRESS;
1024     m_temporary_allocation_size = 0;
1025   }
1026 
1027 private:
1028   CompilerType m_type;
1029   bool m_is_program_reference;
1030   bool m_keep_in_memory;
1031 
1032   lldb::addr_t m_temporary_allocation;
1033   size_t m_temporary_allocation_size;
1034   Materializer::PersistentVariableDelegate *m_delegate;
1035 };
1036 
1037 uint32_t Materializer::AddResultVariable(const CompilerType &type,
1038                                          bool is_program_reference,
1039                                          bool keep_in_memory,
1040                                          PersistentVariableDelegate *delegate,
1041                                          Status &err) {
1042   EntityVector::iterator iter = m_entities.insert(m_entities.end(), EntityUP());
1043   iter->reset(new EntityResultVariable(type, is_program_reference,
1044                                        keep_in_memory, delegate));
1045   uint32_t ret = AddStructMember(**iter);
1046   (*iter)->SetOffset(ret);
1047   return ret;
1048 }
1049 
1050 class EntitySymbol : public Materializer::Entity {
1051 public:
1052   EntitySymbol(const Symbol &symbol) : Entity(), m_symbol(symbol) {
1053     // Hard-coding to maximum size of a symbol
1054     m_size = 8;
1055     m_alignment = 8;
1056   }
1057 
1058   void Materialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
1059                    lldb::addr_t process_address, Status &err) override {
1060     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1061 
1062     const lldb::addr_t load_addr = process_address + m_offset;
1063 
1064     if (log) {
1065       log->Printf("EntitySymbol::Materialize [address = 0x%" PRIx64
1066                   ", m_symbol = %s]",
1067                   (uint64_t)load_addr, m_symbol.GetName().AsCString());
1068     }
1069 
1070     const Address sym_address = m_symbol.GetAddress();
1071 
1072     ExecutionContextScope *exe_scope = map.GetBestExecutionContextScope();
1073 
1074     lldb::TargetSP target_sp;
1075 
1076     if (exe_scope)
1077       target_sp = map.GetBestExecutionContextScope()->CalculateTarget();
1078 
1079     if (!target_sp) {
1080       err.SetErrorStringWithFormat(
1081           "couldn't resolve symbol %s because there is no target",
1082           m_symbol.GetName().AsCString());
1083       return;
1084     }
1085 
1086     lldb::addr_t resolved_address = sym_address.GetLoadAddress(target_sp.get());
1087 
1088     if (resolved_address == LLDB_INVALID_ADDRESS)
1089       resolved_address = sym_address.GetFileAddress();
1090 
1091     Status pointer_write_error;
1092 
1093     map.WritePointerToMemory(load_addr, resolved_address, pointer_write_error);
1094 
1095     if (!pointer_write_error.Success()) {
1096       err.SetErrorStringWithFormat(
1097           "couldn't write the address of symbol %s: %s",
1098           m_symbol.GetName().AsCString(), pointer_write_error.AsCString());
1099       return;
1100     }
1101   }
1102 
1103   void Dematerialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
1104                      lldb::addr_t process_address, lldb::addr_t frame_top,
1105                      lldb::addr_t frame_bottom, Status &err) override {
1106     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1107 
1108     const lldb::addr_t load_addr = process_address + m_offset;
1109 
1110     if (log) {
1111       log->Printf("EntitySymbol::Dematerialize [address = 0x%" PRIx64
1112                   ", m_symbol = %s]",
1113                   (uint64_t)load_addr, m_symbol.GetName().AsCString());
1114     }
1115 
1116     // no work needs to be done
1117   }
1118 
1119   void DumpToLog(IRMemoryMap &map, lldb::addr_t process_address,
1120                  Log *log) override {
1121     StreamString dump_stream;
1122 
1123     Status err;
1124 
1125     const lldb::addr_t load_addr = process_address + m_offset;
1126 
1127     dump_stream.Printf("0x%" PRIx64 ": EntitySymbol (%s)\n", load_addr,
1128                        m_symbol.GetName().AsCString());
1129 
1130     {
1131       dump_stream.Printf("Pointer:\n");
1132 
1133       DataBufferHeap data(m_size, 0);
1134 
1135       map.ReadMemory(data.GetBytes(), load_addr, m_size, err);
1136 
1137       if (!err.Success()) {
1138         dump_stream.Printf("  <could not be read>\n");
1139       } else {
1140         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
1141                      load_addr);
1142 
1143         dump_stream.PutChar('\n');
1144       }
1145     }
1146 
1147     log->PutString(dump_stream.GetString());
1148   }
1149 
1150   void Wipe(IRMemoryMap &map, lldb::addr_t process_address) override {}
1151 
1152 private:
1153   Symbol m_symbol;
1154 };
1155 
1156 uint32_t Materializer::AddSymbol(const Symbol &symbol_sp, Status &err) {
1157   EntityVector::iterator iter = m_entities.insert(m_entities.end(), EntityUP());
1158   iter->reset(new EntitySymbol(symbol_sp));
1159   uint32_t ret = AddStructMember(**iter);
1160   (*iter)->SetOffset(ret);
1161   return ret;
1162 }
1163 
1164 class EntityRegister : public Materializer::Entity {
1165 public:
1166   EntityRegister(const RegisterInfo &register_info)
1167       : Entity(), m_register_info(register_info) {
1168     // Hard-coding alignment conservatively
1169     m_size = m_register_info.byte_size;
1170     m_alignment = m_register_info.byte_size;
1171   }
1172 
1173   void Materialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
1174                    lldb::addr_t process_address, Status &err) override {
1175     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1176 
1177     const lldb::addr_t load_addr = process_address + m_offset;
1178 
1179     if (log) {
1180       log->Printf("EntityRegister::Materialize [address = 0x%" PRIx64
1181                   ", m_register_info = %s]",
1182                   (uint64_t)load_addr, m_register_info.name);
1183     }
1184 
1185     RegisterValue reg_value;
1186 
1187     if (!frame_sp.get()) {
1188       err.SetErrorStringWithFormat(
1189           "couldn't materialize register %s without a stack frame",
1190           m_register_info.name);
1191       return;
1192     }
1193 
1194     lldb::RegisterContextSP reg_context_sp = frame_sp->GetRegisterContext();
1195 
1196     if (!reg_context_sp->ReadRegister(&m_register_info, reg_value)) {
1197       err.SetErrorStringWithFormat("couldn't read the value of register %s",
1198                                    m_register_info.name);
1199       return;
1200     }
1201 
1202     DataExtractor register_data;
1203 
1204     if (!reg_value.GetData(register_data)) {
1205       err.SetErrorStringWithFormat("couldn't get the data for register %s",
1206                                    m_register_info.name);
1207       return;
1208     }
1209 
1210     if (register_data.GetByteSize() != m_register_info.byte_size) {
1211       err.SetErrorStringWithFormat(
1212           "data for register %s had size %llu but we expected %llu",
1213           m_register_info.name, (unsigned long long)register_data.GetByteSize(),
1214           (unsigned long long)m_register_info.byte_size);
1215       return;
1216     }
1217 
1218     m_register_contents.reset(new DataBufferHeap(register_data.GetDataStart(),
1219                                                  register_data.GetByteSize()));
1220 
1221     Status write_error;
1222 
1223     map.WriteMemory(load_addr, register_data.GetDataStart(),
1224                     register_data.GetByteSize(), write_error);
1225 
1226     if (!write_error.Success()) {
1227       err.SetErrorStringWithFormat(
1228           "couldn't write the contents of register %s: %s",
1229           m_register_info.name, write_error.AsCString());
1230       return;
1231     }
1232   }
1233 
1234   void Dematerialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
1235                      lldb::addr_t process_address, lldb::addr_t frame_top,
1236                      lldb::addr_t frame_bottom, Status &err) override {
1237     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
1238 
1239     const lldb::addr_t load_addr = process_address + m_offset;
1240 
1241     if (log) {
1242       log->Printf("EntityRegister::Dematerialize [address = 0x%" PRIx64
1243                   ", m_register_info = %s]",
1244                   (uint64_t)load_addr, m_register_info.name);
1245     }
1246 
1247     Status extract_error;
1248 
1249     DataExtractor register_data;
1250 
1251     if (!frame_sp.get()) {
1252       err.SetErrorStringWithFormat(
1253           "couldn't dematerialize register %s without a stack frame",
1254           m_register_info.name);
1255       return;
1256     }
1257 
1258     lldb::RegisterContextSP reg_context_sp = frame_sp->GetRegisterContext();
1259 
1260     map.GetMemoryData(register_data, load_addr, m_register_info.byte_size,
1261                       extract_error);
1262 
1263     if (!extract_error.Success()) {
1264       err.SetErrorStringWithFormat("couldn't get the data for register %s: %s",
1265                                    m_register_info.name,
1266                                    extract_error.AsCString());
1267       return;
1268     }
1269 
1270     if (!memcmp(register_data.GetDataStart(), m_register_contents->GetBytes(),
1271                 register_data.GetByteSize())) {
1272       // No write required, and in particular we avoid errors if the register
1273       // wasn't writable
1274 
1275       m_register_contents.reset();
1276       return;
1277     }
1278 
1279     m_register_contents.reset();
1280 
1281     RegisterValue register_value(
1282         const_cast<uint8_t *>(register_data.GetDataStart()),
1283         register_data.GetByteSize(), register_data.GetByteOrder());
1284 
1285     if (!reg_context_sp->WriteRegister(&m_register_info, register_value)) {
1286       err.SetErrorStringWithFormat("couldn't write the value of register %s",
1287                                    m_register_info.name);
1288       return;
1289     }
1290   }
1291 
1292   void DumpToLog(IRMemoryMap &map, lldb::addr_t process_address,
1293                  Log *log) override {
1294     StreamString dump_stream;
1295 
1296     Status err;
1297 
1298     const lldb::addr_t load_addr = process_address + m_offset;
1299 
1300     dump_stream.Printf("0x%" PRIx64 ": EntityRegister (%s)\n", load_addr,
1301                        m_register_info.name);
1302 
1303     {
1304       dump_stream.Printf("Value:\n");
1305 
1306       DataBufferHeap data(m_size, 0);
1307 
1308       map.ReadMemory(data.GetBytes(), load_addr, m_size, err);
1309 
1310       if (!err.Success()) {
1311         dump_stream.Printf("  <could not be read>\n");
1312       } else {
1313         DumpHexBytes(&dump_stream, data.GetBytes(), data.GetByteSize(), 16,
1314                      load_addr);
1315 
1316         dump_stream.PutChar('\n');
1317       }
1318     }
1319 
1320     log->PutString(dump_stream.GetString());
1321   }
1322 
1323   void Wipe(IRMemoryMap &map, lldb::addr_t process_address) override {}
1324 
1325 private:
1326   RegisterInfo m_register_info;
1327   lldb::DataBufferSP m_register_contents;
1328 };
1329 
1330 uint32_t Materializer::AddRegister(const RegisterInfo &register_info,
1331                                    Status &err) {
1332   EntityVector::iterator iter = m_entities.insert(m_entities.end(), EntityUP());
1333   iter->reset(new EntityRegister(register_info));
1334   uint32_t ret = AddStructMember(**iter);
1335   (*iter)->SetOffset(ret);
1336   return ret;
1337 }
1338 
1339 Materializer::Materializer()
1340     : m_dematerializer_wp(), m_current_offset(0), m_struct_alignment(8) {}
1341 
1342 Materializer::~Materializer() {
1343   DematerializerSP dematerializer_sp = m_dematerializer_wp.lock();
1344 
1345   if (dematerializer_sp)
1346     dematerializer_sp->Wipe();
1347 }
1348 
1349 Materializer::DematerializerSP
1350 Materializer::Materialize(lldb::StackFrameSP &frame_sp, IRMemoryMap &map,
1351                           lldb::addr_t process_address, Status &error) {
1352   ExecutionContextScope *exe_scope = frame_sp.get();
1353 
1354   if (!exe_scope)
1355     exe_scope = map.GetBestExecutionContextScope();
1356 
1357   DematerializerSP dematerializer_sp = m_dematerializer_wp.lock();
1358 
1359   if (dematerializer_sp) {
1360     error.SetErrorToGenericError();
1361     error.SetErrorString("Couldn't materialize: already materialized");
1362   }
1363 
1364   DematerializerSP ret(
1365       new Dematerializer(*this, frame_sp, map, process_address));
1366 
1367   if (!exe_scope) {
1368     error.SetErrorToGenericError();
1369     error.SetErrorString("Couldn't materialize: target doesn't exist");
1370   }
1371 
1372   for (EntityUP &entity_up : m_entities) {
1373     entity_up->Materialize(frame_sp, map, process_address, error);
1374 
1375     if (!error.Success())
1376       return DematerializerSP();
1377   }
1378 
1379   if (Log *log =
1380           lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS)) {
1381     log->Printf(
1382         "Materializer::Materialize (frame_sp = %p, process_address = 0x%" PRIx64
1383         ") materialized:",
1384         static_cast<void *>(frame_sp.get()), process_address);
1385     for (EntityUP &entity_up : m_entities)
1386       entity_up->DumpToLog(map, process_address, log);
1387   }
1388 
1389   m_dematerializer_wp = ret;
1390 
1391   return ret;
1392 }
1393 
1394 void Materializer::Dematerializer::Dematerialize(Status &error,
1395                                                  lldb::addr_t frame_bottom,
1396                                                  lldb::addr_t frame_top) {
1397   lldb::StackFrameSP frame_sp;
1398 
1399   lldb::ThreadSP thread_sp = m_thread_wp.lock();
1400   if (thread_sp)
1401     frame_sp = thread_sp->GetFrameWithStackID(m_stack_id);
1402 
1403   ExecutionContextScope *exe_scope = m_map->GetBestExecutionContextScope();
1404 
1405   if (!IsValid()) {
1406     error.SetErrorToGenericError();
1407     error.SetErrorString("Couldn't dematerialize: invalid dematerializer");
1408   }
1409 
1410   if (!exe_scope) {
1411     error.SetErrorToGenericError();
1412     error.SetErrorString("Couldn't dematerialize: target is gone");
1413   } else {
1414     if (Log *log =
1415             lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS)) {
1416       log->Printf("Materializer::Dematerialize (frame_sp = %p, process_address "
1417                   "= 0x%" PRIx64 ") about to dematerialize:",
1418                   static_cast<void *>(frame_sp.get()), m_process_address);
1419       for (EntityUP &entity_up : m_materializer->m_entities)
1420         entity_up->DumpToLog(*m_map, m_process_address, log);
1421     }
1422 
1423     for (EntityUP &entity_up : m_materializer->m_entities) {
1424       entity_up->Dematerialize(frame_sp, *m_map, m_process_address, frame_top,
1425                                frame_bottom, error);
1426 
1427       if (!error.Success())
1428         break;
1429     }
1430   }
1431 
1432   Wipe();
1433 }
1434 
1435 void Materializer::Dematerializer::Wipe() {
1436   if (!IsValid())
1437     return;
1438 
1439   for (EntityUP &entity_up : m_materializer->m_entities) {
1440     entity_up->Wipe(*m_map, m_process_address);
1441   }
1442 
1443   m_materializer = nullptr;
1444   m_map = nullptr;
1445   m_process_address = LLDB_INVALID_ADDRESS;
1446 }
1447 
1448 Materializer::PersistentVariableDelegate::~PersistentVariableDelegate() =
1449     default;
1450