1 //===-- NSArray.cpp ---------------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // C Includes
11 // C++ Includes
12 // Other libraries and framework includes
13 #include "clang/AST/ASTContext.h"
14 
15 // Project includes
16 #include "Cocoa.h"
17 
18 #include "lldb/Core/DataBufferHeap.h"
19 #include "lldb/Core/Error.h"
20 #include "lldb/Core/Stream.h"
21 #include "lldb/Core/ValueObject.h"
22 #include "lldb/Core/ValueObjectConstResult.h"
23 #include "lldb/DataFormatters/FormattersHelpers.h"
24 #include "lldb/Expression/FunctionCaller.h"
25 #include "lldb/Host/Endian.h"
26 #include "lldb/Symbol/ClangASTContext.h"
27 #include "lldb/Target/Language.h"
28 #include "lldb/Target/ObjCLanguageRuntime.h"
29 #include "Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.h"
30 #include "lldb/Target/Target.h"
31 
32 using namespace lldb;
33 using namespace lldb_private;
34 using namespace lldb_private::formatters;
35 
36 namespace  lldb_private {
37     namespace formatters {
38         class NSArrayMSyntheticFrontEnd : public SyntheticChildrenFrontEnd
39         {
40         public:
41             NSArrayMSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp);
42 
43             ~NSArrayMSyntheticFrontEnd() override = default;
44 
45             size_t
46             CalculateNumChildren() override;
47 
48             lldb::ValueObjectSP
49             GetChildAtIndex(size_t idx) override;
50 
51             bool
52             Update() override = 0;
53 
54             bool
55             MightHaveChildren() override;
56 
57             size_t
58             GetIndexOfChildWithName(const ConstString &name) override;
59 
60         protected:
61             virtual lldb::addr_t
62             GetDataAddress () = 0;
63 
64             virtual uint64_t
65             GetUsedCount () = 0;
66 
67             virtual uint64_t
68             GetOffset () = 0;
69 
70             virtual uint64_t
71             GetSize () = 0;
72 
73             ExecutionContextRef m_exe_ctx_ref;
74             uint8_t m_ptr_size;
75             CompilerType m_id_type;
76             std::vector<lldb::ValueObjectSP> m_children;
77         };
78 
79         class NSArrayMSyntheticFrontEnd_109 : public NSArrayMSyntheticFrontEnd
80         {
81         public:
82             NSArrayMSyntheticFrontEnd_109 (lldb::ValueObjectSP valobj_sp);
83 
84             ~NSArrayMSyntheticFrontEnd_109() override;
85 
86             bool
87             Update() override;
88 
89         protected:
90             lldb::addr_t
91             GetDataAddress() override;
92 
93             uint64_t
94             GetUsedCount() override;
95 
96             uint64_t
97             GetOffset() override;
98 
99             uint64_t
100             GetSize() override;
101 
102         private:
103             struct DataDescriptor_32
104             {
105                 uint32_t _used;
106                 uint32_t _priv1 : 2;
107                 uint32_t _size : 30;
108                 uint32_t _priv2 : 2;
109                 uint32_t _offset : 30;
110                 uint32_t _priv3;
111                 uint32_t _data;
112             };
113 
114             struct DataDescriptor_64
115             {
116                 uint64_t _used;
117                 uint64_t _priv1 : 2;
118                 uint64_t _size : 62;
119                 uint64_t _priv2 : 2;
120                 uint64_t _offset : 62;
121                 uint32_t _priv3;
122                 uint64_t _data;
123             };
124 
125             DataDescriptor_32 *m_data_32;
126             DataDescriptor_64 *m_data_64;
127         };
128 
129         class NSArrayMSyntheticFrontEnd_1010 : public NSArrayMSyntheticFrontEnd
130         {
131         public:
132             NSArrayMSyntheticFrontEnd_1010 (lldb::ValueObjectSP valobj_sp);
133 
134             ~NSArrayMSyntheticFrontEnd_1010() override;
135 
136             bool
137             Update() override;
138 
139         protected:
140             lldb::addr_t
141             GetDataAddress() override;
142 
143             uint64_t
144             GetUsedCount() override;
145 
146             uint64_t
147             GetOffset() override;
148 
149             uint64_t
150             GetSize() override;
151 
152         private:
153             struct DataDescriptor_32
154             {
155                 uint32_t _used;
156                 uint32_t _offset;
157                 uint32_t _size : 28;
158                 uint64_t _priv1 : 4;
159                 uint32_t _priv2;
160                 uint32_t _data;
161             };
162 
163             struct DataDescriptor_64
164             {
165                 uint64_t _used;
166                 uint64_t _offset;
167                 uint64_t _size : 60;
168                 uint64_t _priv1 : 4;
169                 uint32_t _priv2;
170                 uint64_t _data;
171             };
172 
173             DataDescriptor_32 *m_data_32;
174             DataDescriptor_64 *m_data_64;
175         };
176 
177         class NSArrayISyntheticFrontEnd : public SyntheticChildrenFrontEnd
178         {
179         public:
180             NSArrayISyntheticFrontEnd (lldb::ValueObjectSP valobj_sp);
181 
182             ~NSArrayISyntheticFrontEnd() override = default;
183 
184             size_t
185             CalculateNumChildren() override;
186 
187             lldb::ValueObjectSP
188             GetChildAtIndex(size_t idx) override;
189 
190             bool
191             Update() override;
192 
193             bool
194             MightHaveChildren() override;
195 
196             size_t
197             GetIndexOfChildWithName(const ConstString &name) override;
198 
199         private:
200             ExecutionContextRef m_exe_ctx_ref;
201             uint8_t m_ptr_size;
202             uint64_t m_items;
203             lldb::addr_t m_data_ptr;
204             CompilerType m_id_type;
205             std::vector<lldb::ValueObjectSP> m_children;
206         };
207 
208         class NSArray0SyntheticFrontEnd : public SyntheticChildrenFrontEnd
209         {
210         public:
211             NSArray0SyntheticFrontEnd (lldb::ValueObjectSP valobj_sp);
212 
213             ~NSArray0SyntheticFrontEnd() override = default;
214 
215             size_t
216             CalculateNumChildren() override;
217 
218             lldb::ValueObjectSP
219             GetChildAtIndex(size_t idx) override;
220 
221             bool
222             Update() override;
223 
224             bool
225             MightHaveChildren() override;
226 
227             size_t
228             GetIndexOfChildWithName(const ConstString &name) override;
229         };
230 
231         class NSArray1SyntheticFrontEnd : public SyntheticChildrenFrontEnd
232         {
233         public:
234             NSArray1SyntheticFrontEnd (lldb::ValueObjectSP valobj_sp);
235 
236             ~NSArray1SyntheticFrontEnd() override = default;
237 
238             size_t
239             CalculateNumChildren() override;
240 
241             lldb::ValueObjectSP
242             GetChildAtIndex(size_t idx) override;
243 
244             bool
245             Update() override;
246 
247             bool
248             MightHaveChildren() override;
249 
250             size_t
251             GetIndexOfChildWithName(const ConstString &name) override;
252         };
253     } // namespace formatters
254 } // namespace lldb_private
255 
256 bool
257 lldb_private::formatters::NSArraySummaryProvider (ValueObject& valobj, Stream& stream, const TypeSummaryOptions& options)
258 {
259     static ConstString g_TypeHint("NSArray");
260 
261     ProcessSP process_sp = valobj.GetProcessSP();
262     if (!process_sp)
263         return false;
264 
265     ObjCLanguageRuntime* runtime = (ObjCLanguageRuntime*)process_sp->GetLanguageRuntime(lldb::eLanguageTypeObjC);
266 
267     if (!runtime)
268         return false;
269 
270     ObjCLanguageRuntime::ClassDescriptorSP descriptor(runtime->GetClassDescriptor(valobj));
271 
272     if (!descriptor || !descriptor->IsValid())
273         return false;
274 
275     uint32_t ptr_size = process_sp->GetAddressByteSize();
276 
277     lldb::addr_t valobj_addr = valobj.GetValueAsUnsigned(0);
278 
279     if (!valobj_addr)
280         return false;
281 
282     uint64_t value = 0;
283 
284     ConstString class_name(descriptor->GetClassName());
285 
286     static const ConstString g_NSArrayI("__NSArrayI");
287     static const ConstString g_NSArrayM("__NSArrayM");
288     static const ConstString g_NSArray0("__NSArray0");
289     static const ConstString g_NSArray1("__NSSingleObjectArrayI");
290     static const ConstString g_NSArrayCF("__NSCFArray");
291 
292     if (class_name.IsEmpty())
293         return false;
294 
295     if (class_name == g_NSArrayI)
296     {
297         Error error;
298         value = process_sp->ReadUnsignedIntegerFromMemory(valobj_addr + ptr_size, ptr_size, 0, error);
299         if (error.Fail())
300             return false;
301     }
302     else if (class_name == g_NSArrayM)
303     {
304         Error error;
305         value = process_sp->ReadUnsignedIntegerFromMemory(valobj_addr + ptr_size, ptr_size, 0, error);
306         if (error.Fail())
307             return false;
308     }
309     else if (class_name == g_NSArray0)
310     {
311         value = 0;
312     }
313     else if (class_name == g_NSArray1)
314     {
315         value = 1;
316     }
317     else if (class_name == g_NSArrayCF)
318     {
319         Error error;
320         value = process_sp->ReadUnsignedIntegerFromMemory(valobj_addr + 2 * ptr_size, ptr_size, 0, error);
321         if (error.Fail())
322             return false;
323     }
324     else
325         return false;
326 
327     std::string prefix,suffix;
328     if (Language* language = Language::FindPlugin(options.GetLanguage()))
329     {
330         if (!language->GetFormatterPrefixSuffix(valobj, g_TypeHint, prefix, suffix))
331         {
332             prefix.clear();
333             suffix.clear();
334         }
335     }
336 
337     stream.Printf("%s%" PRIu64 " %s%s%s",
338                   prefix.c_str(),
339                   value,
340                   "element",
341                   value == 1 ? "" : "s",
342                   suffix.c_str());
343     return true;
344 }
345 
346 lldb_private::formatters::NSArrayMSyntheticFrontEnd::NSArrayMSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp) :
347 SyntheticChildrenFrontEnd(*valobj_sp),
348 m_exe_ctx_ref(),
349 m_ptr_size(8),
350 m_id_type(),
351 m_children()
352 {
353     if (valobj_sp)
354     {
355         clang::ASTContext *ast = valobj_sp->GetExecutionContextRef().GetTargetSP()->GetScratchClangASTContext()->getASTContext();
356         if (ast)
357             m_id_type = CompilerType(ast, ast->ObjCBuiltinIdTy);
358         if (valobj_sp->GetProcessSP())
359             m_ptr_size = valobj_sp->GetProcessSP()->GetAddressByteSize();
360     }
361 }
362 
363 lldb_private::formatters::NSArrayMSyntheticFrontEnd_109::NSArrayMSyntheticFrontEnd_109 (lldb::ValueObjectSP valobj_sp) :
364     NSArrayMSyntheticFrontEnd(valobj_sp),
365     m_data_32(nullptr),
366     m_data_64(nullptr)
367 {
368 }
369 
370 lldb_private::formatters::NSArrayMSyntheticFrontEnd_1010::NSArrayMSyntheticFrontEnd_1010 (lldb::ValueObjectSP valobj_sp) :
371     NSArrayMSyntheticFrontEnd(valobj_sp),
372     m_data_32(nullptr),
373     m_data_64(nullptr)
374 {
375 }
376 
377 size_t
378 lldb_private::formatters::NSArrayMSyntheticFrontEnd::CalculateNumChildren ()
379 {
380     return GetUsedCount();
381 }
382 
383 lldb::ValueObjectSP
384 lldb_private::formatters::NSArrayMSyntheticFrontEnd::GetChildAtIndex (size_t idx)
385 {
386     if (idx >= CalculateNumChildren())
387         return lldb::ValueObjectSP();
388     lldb::addr_t object_at_idx = GetDataAddress();
389     size_t pyhs_idx = idx;
390     pyhs_idx += GetOffset();
391     if (GetSize() <= pyhs_idx)
392         pyhs_idx -= GetSize();
393     object_at_idx += (pyhs_idx * m_ptr_size);
394     StreamString idx_name;
395     idx_name.Printf("[%" PRIu64 "]", (uint64_t)idx);
396     lldb::ValueObjectSP retval_sp = CreateValueObjectFromAddress(idx_name.GetData(),
397                                                                  object_at_idx,
398                                                                  m_exe_ctx_ref,
399                                                                  m_id_type);
400     m_children.push_back(retval_sp);
401     return retval_sp;
402 }
403 
404 bool
405 lldb_private::formatters::NSArrayMSyntheticFrontEnd_109::Update()
406 {
407     m_children.clear();
408     ValueObjectSP valobj_sp = m_backend.GetSP();
409     m_ptr_size = 0;
410     delete m_data_32;
411     m_data_32 = nullptr;
412     delete m_data_64;
413     m_data_64 = nullptr;
414     if (!valobj_sp)
415         return false;
416     m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
417     Error error;
418     error.Clear();
419     lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
420     if (!process_sp)
421         return false;
422     m_ptr_size = process_sp->GetAddressByteSize();
423     uint64_t data_location = valobj_sp->GetValueAsUnsigned(0) + m_ptr_size;
424     if (m_ptr_size == 4)
425     {
426         m_data_32 = new DataDescriptor_32();
427         process_sp->ReadMemory (data_location, m_data_32, sizeof(DataDescriptor_32), error);
428     }
429     else
430     {
431         m_data_64 = new DataDescriptor_64();
432         process_sp->ReadMemory (data_location, m_data_64, sizeof(DataDescriptor_64), error);
433     }
434     if (error.Fail())
435         return false;
436     return false;
437 }
438 
439 bool
440 lldb_private::formatters::NSArrayMSyntheticFrontEnd_1010::Update()
441 {
442     m_children.clear();
443     ValueObjectSP valobj_sp = m_backend.GetSP();
444     m_ptr_size = 0;
445     delete m_data_32;
446     m_data_32 = nullptr;
447     delete m_data_64;
448     m_data_64 = nullptr;
449     if (!valobj_sp)
450         return false;
451     m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
452     Error error;
453     error.Clear();
454     lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
455     if (!process_sp)
456         return false;
457     m_ptr_size = process_sp->GetAddressByteSize();
458     uint64_t data_location = valobj_sp->GetValueAsUnsigned(0) + m_ptr_size;
459     if (m_ptr_size == 4)
460     {
461         m_data_32 = new DataDescriptor_32();
462         process_sp->ReadMemory (data_location, m_data_32, sizeof(DataDescriptor_32), error);
463     }
464     else
465     {
466         m_data_64 = new DataDescriptor_64();
467         process_sp->ReadMemory (data_location, m_data_64, sizeof(DataDescriptor_64), error);
468     }
469     if (error.Fail())
470         return false;
471     return false;
472 }
473 
474 bool
475 lldb_private::formatters::NSArrayMSyntheticFrontEnd::MightHaveChildren ()
476 {
477     return true;
478 }
479 
480 size_t
481 lldb_private::formatters::NSArrayMSyntheticFrontEnd::GetIndexOfChildWithName (const ConstString &name)
482 {
483     const char* item_name = name.GetCString();
484     uint32_t idx = ExtractIndexFromString(item_name);
485     if (idx < UINT32_MAX && idx >= CalculateNumChildren())
486         return UINT32_MAX;
487     return idx;
488 }
489 
490 lldb_private::formatters::NSArrayMSyntheticFrontEnd_109::~NSArrayMSyntheticFrontEnd_109()
491 {
492     delete m_data_32;
493     m_data_32 = nullptr;
494     delete m_data_64;
495     m_data_64 = nullptr;
496 }
497 
498 lldb::addr_t
499 lldb_private::formatters::NSArrayMSyntheticFrontEnd_109::GetDataAddress ()
500 {
501     if (!m_data_32 && !m_data_64)
502         return LLDB_INVALID_ADDRESS;
503     return m_data_32 ? m_data_32->_data :
504     m_data_64->_data;
505 }
506 
507 uint64_t
508 lldb_private::formatters::NSArrayMSyntheticFrontEnd_109::GetUsedCount ()
509 {
510     if (!m_data_32 && !m_data_64)
511         return 0;
512     return m_data_32 ? m_data_32->_used :
513     m_data_64->_used;
514 }
515 
516 uint64_t
517 lldb_private::formatters::NSArrayMSyntheticFrontEnd_109::GetOffset ()
518 {
519     if (!m_data_32 && !m_data_64)
520         return 0;
521     return m_data_32 ? m_data_32->_offset :
522     m_data_64->_offset;
523 }
524 
525 uint64_t
526 lldb_private::formatters::NSArrayMSyntheticFrontEnd_109::GetSize ()
527 {
528     if (!m_data_32 && !m_data_64)
529         return 0;
530     return m_data_32 ? m_data_32->_size :
531     m_data_64->_size;
532 }
533 
534 lldb_private::formatters::NSArrayMSyntheticFrontEnd_1010::~NSArrayMSyntheticFrontEnd_1010()
535 {
536     delete m_data_32;
537     m_data_32 = nullptr;
538     delete m_data_64;
539     m_data_64 = nullptr;
540 }
541 
542 lldb::addr_t
543 lldb_private::formatters::NSArrayMSyntheticFrontEnd_1010::GetDataAddress ()
544 {
545     if (!m_data_32 && !m_data_64)
546         return LLDB_INVALID_ADDRESS;
547     return m_data_32 ? m_data_32->_data :
548     m_data_64->_data;
549 }
550 
551 uint64_t
552 lldb_private::formatters::NSArrayMSyntheticFrontEnd_1010::GetUsedCount ()
553 {
554     if (!m_data_32 && !m_data_64)
555         return 0;
556     return m_data_32 ? m_data_32->_used :
557     m_data_64->_used;
558 }
559 
560 uint64_t
561 lldb_private::formatters::NSArrayMSyntheticFrontEnd_1010::GetOffset ()
562 {
563     if (!m_data_32 && !m_data_64)
564         return 0;
565     return m_data_32 ? m_data_32->_offset :
566     m_data_64->_offset;
567 }
568 
569 uint64_t
570 lldb_private::formatters::NSArrayMSyntheticFrontEnd_1010::GetSize ()
571 {
572     if (!m_data_32 && !m_data_64)
573         return 0;
574     return m_data_32 ? m_data_32->_size :
575     m_data_64->_size;
576 }
577 
578 lldb_private::formatters::NSArrayISyntheticFrontEnd::NSArrayISyntheticFrontEnd (lldb::ValueObjectSP valobj_sp) :
579     SyntheticChildrenFrontEnd(*valobj_sp),
580     m_exe_ctx_ref(),
581     m_ptr_size(8),
582     m_items(0),
583     m_data_ptr(0)
584 {
585     if (valobj_sp)
586     {
587         CompilerType type = valobj_sp->GetCompilerType();
588         if (type)
589         {
590             ClangASTContext *ast = valobj_sp->GetExecutionContextRef().GetTargetSP()->GetScratchClangASTContext();
591             if (ast)
592                 m_id_type = CompilerType(ast->getASTContext(), ast->getASTContext()->ObjCBuiltinIdTy);
593         }
594     }
595 }
596 
597 size_t
598 lldb_private::formatters::NSArrayISyntheticFrontEnd::GetIndexOfChildWithName (const ConstString &name)
599 {
600     const char* item_name = name.GetCString();
601     uint32_t idx = ExtractIndexFromString(item_name);
602     if (idx < UINT32_MAX && idx >= CalculateNumChildren())
603         return UINT32_MAX;
604     return idx;
605 }
606 
607 size_t
608 lldb_private::formatters::NSArrayISyntheticFrontEnd::CalculateNumChildren ()
609 {
610     return m_items;
611 }
612 
613 bool
614 lldb_private::formatters::NSArrayISyntheticFrontEnd::Update()
615 {
616     m_ptr_size = 0;
617     m_items = 0;
618     m_data_ptr = 0;
619     m_children.clear();
620     ValueObjectSP valobj_sp = m_backend.GetSP();
621     if (!valobj_sp)
622         return false;
623     m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
624     Error error;
625     error.Clear();
626     lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
627     if (!process_sp)
628         return false;
629     m_ptr_size = process_sp->GetAddressByteSize();
630     uint64_t data_location = valobj_sp->GetValueAsUnsigned(0) + m_ptr_size;
631     m_items = process_sp->ReadPointerFromMemory(data_location, error);
632     if (error.Fail())
633         return false;
634     m_data_ptr = data_location+m_ptr_size;
635     return false;
636 }
637 
638 bool
639 lldb_private::formatters::NSArrayISyntheticFrontEnd::MightHaveChildren ()
640 {
641     return true;
642 }
643 
644 lldb::ValueObjectSP
645 lldb_private::formatters::NSArrayISyntheticFrontEnd::GetChildAtIndex (size_t idx)
646 {
647     if (idx >= CalculateNumChildren())
648         return lldb::ValueObjectSP();
649     lldb::addr_t object_at_idx = m_data_ptr;
650     object_at_idx += (idx * m_ptr_size);
651     ProcessSP process_sp = m_exe_ctx_ref.GetProcessSP();
652     if (!process_sp)
653         return lldb::ValueObjectSP();
654     Error error;
655     if (error.Fail())
656         return lldb::ValueObjectSP();
657     StreamString idx_name;
658     idx_name.Printf("[%" PRIu64 "]", (uint64_t)idx);
659     lldb::ValueObjectSP retval_sp = CreateValueObjectFromAddress(idx_name.GetData(),
660                                                                  object_at_idx,
661                                                                  m_exe_ctx_ref,
662                                                                  m_id_type);
663     m_children.push_back(retval_sp);
664     return retval_sp;
665 }
666 
667 lldb_private::formatters::NSArray0SyntheticFrontEnd::NSArray0SyntheticFrontEnd (lldb::ValueObjectSP valobj_sp) :
668     SyntheticChildrenFrontEnd(*valobj_sp)
669 {
670 }
671 
672 size_t
673 lldb_private::formatters::NSArray0SyntheticFrontEnd::GetIndexOfChildWithName (const ConstString &name)
674 {
675     return UINT32_MAX;
676 }
677 
678 size_t
679 lldb_private::formatters::NSArray0SyntheticFrontEnd::CalculateNumChildren ()
680 {
681     return 0;
682 }
683 
684 bool
685 lldb_private::formatters::NSArray0SyntheticFrontEnd::Update()
686 {
687     return false;
688 }
689 
690 bool
691 lldb_private::formatters::NSArray0SyntheticFrontEnd::MightHaveChildren ()
692 {
693     return false;
694 }
695 
696 lldb::ValueObjectSP
697 lldb_private::formatters::NSArray0SyntheticFrontEnd::GetChildAtIndex (size_t idx)
698 {
699     return lldb::ValueObjectSP();
700 }
701 
702 lldb_private::formatters::NSArray1SyntheticFrontEnd::NSArray1SyntheticFrontEnd (lldb::ValueObjectSP valobj_sp) :
703 SyntheticChildrenFrontEnd (*valobj_sp.get())
704 {
705 }
706 
707 size_t
708 lldb_private::formatters::NSArray1SyntheticFrontEnd::GetIndexOfChildWithName (const ConstString &name)
709 {
710     static const ConstString g_zero("[0]");
711 
712     if (name == g_zero)
713         return 0;
714 
715     return UINT32_MAX;
716 }
717 
718 size_t
719 lldb_private::formatters::NSArray1SyntheticFrontEnd::CalculateNumChildren ()
720 {
721     return 1;
722 }
723 
724 bool
725 lldb_private::formatters::NSArray1SyntheticFrontEnd::Update()
726 {
727     return false;
728 }
729 
730 bool
731 lldb_private::formatters::NSArray1SyntheticFrontEnd::MightHaveChildren ()
732 {
733     return true;
734 }
735 
736 lldb::ValueObjectSP
737 lldb_private::formatters::NSArray1SyntheticFrontEnd::GetChildAtIndex (size_t idx)
738 {
739     static const ConstString g_zero("[0]");
740 
741     if (idx == 0)
742     {
743         CompilerType id_type(m_backend.GetTargetSP()->GetScratchClangASTContext()->GetBasicType(lldb::eBasicTypeObjCID));
744         return m_backend.GetSyntheticChildAtOffset(m_backend.GetProcessSP()->GetAddressByteSize(), id_type, true, g_zero);
745     }
746     return lldb::ValueObjectSP();
747 }
748 
749 SyntheticChildrenFrontEnd* lldb_private::formatters::NSArraySyntheticFrontEndCreator (CXXSyntheticChildren*, lldb::ValueObjectSP valobj_sp)
750 {
751     if (!valobj_sp)
752         return nullptr;
753 
754     lldb::ProcessSP process_sp (valobj_sp->GetProcessSP());
755     if (!process_sp)
756         return nullptr;
757     AppleObjCRuntime *runtime = llvm::dyn_cast_or_null<AppleObjCRuntime>(process_sp->GetObjCLanguageRuntime());
758     if (!runtime)
759         return nullptr;
760 
761     CompilerType valobj_type(valobj_sp->GetCompilerType());
762     Flags flags(valobj_type.GetTypeInfo());
763 
764     if (flags.IsClear(eTypeIsPointer))
765     {
766         Error error;
767         valobj_sp = valobj_sp->AddressOf(error);
768         if (error.Fail() || !valobj_sp)
769             return nullptr;
770     }
771 
772     ObjCLanguageRuntime::ClassDescriptorSP descriptor(runtime->GetClassDescriptor(*valobj_sp));
773 
774     if (!descriptor || !descriptor->IsValid())
775         return nullptr;
776 
777     ConstString class_name(descriptor->GetClassName());
778 
779     static const ConstString g_NSArrayI("__NSArrayI");
780     static const ConstString g_NSArrayM("__NSArrayM");
781     static const ConstString g_NSArray0("__NSArray0");
782     static const ConstString g_NSArray1("__NSSingleObjectArrayI");
783 
784     if (class_name.IsEmpty())
785         return nullptr;
786 
787     if (class_name == g_NSArrayI)
788     {
789         return (new NSArrayISyntheticFrontEnd(valobj_sp));
790     }
791     else if (class_name == g_NSArray0)
792     {
793         return (new NSArray0SyntheticFrontEnd(valobj_sp));
794     }
795     else if (class_name == g_NSArray1)
796     {
797         return (new NSArray1SyntheticFrontEnd(valobj_sp));
798     }
799     else if (class_name == g_NSArrayM)
800     {
801         if (runtime->GetFoundationVersion() >= 1100)
802             return (new NSArrayMSyntheticFrontEnd_1010(valobj_sp));
803         else
804             return (new NSArrayMSyntheticFrontEnd_109(valobj_sp));
805     }
806 
807     return nullptr;
808 }
809