1 //===-- ObjCLanguage.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 #include <mutex>
13 
14 // Other libraries and framework includes
15 // Project includes
16 #include "ObjCLanguage.h"
17 
18 #include "lldb/Core/ConstString.h"
19 #include "lldb/Core/PluginManager.h"
20 #include "lldb/Core/StreamString.h"
21 #include "lldb/Core/ValueObject.h"
22 #include "lldb/DataFormatters/DataVisualization.h"
23 #include "lldb/DataFormatters/FormattersHelpers.h"
24 #include "lldb/Symbol/ClangASTContext.h"
25 #include "lldb/Symbol/CompilerType.h"
26 #include "lldb/Target/ObjCLanguageRuntime.h"
27 #include "lldb/Target/Target.h"
28 
29 #include "CF.h"
30 #include "Cocoa.h"
31 #include "CoreMedia.h"
32 #include "NSDictionary.h"
33 #include "NSSet.h"
34 #include "NSString.h"
35 
36 using namespace lldb;
37 using namespace lldb_private;
38 using namespace lldb_private::formatters;
39 
40 void ObjCLanguage::Initialize() {
41   PluginManager::RegisterPlugin(GetPluginNameStatic(), "Objective-C Language",
42                                 CreateInstance);
43 }
44 
45 void ObjCLanguage::Terminate() {
46   PluginManager::UnregisterPlugin(CreateInstance);
47 }
48 
49 lldb_private::ConstString ObjCLanguage::GetPluginNameStatic() {
50   static ConstString g_name("objc");
51   return g_name;
52 }
53 
54 //------------------------------------------------------------------
55 // PluginInterface protocol
56 //------------------------------------------------------------------
57 
58 lldb_private::ConstString ObjCLanguage::GetPluginName() {
59   return GetPluginNameStatic();
60 }
61 
62 uint32_t ObjCLanguage::GetPluginVersion() { return 1; }
63 
64 //------------------------------------------------------------------
65 // Static Functions
66 //------------------------------------------------------------------
67 
68 Language *ObjCLanguage::CreateInstance(lldb::LanguageType language) {
69   switch (language) {
70   case lldb::eLanguageTypeObjC:
71     return new ObjCLanguage();
72   default:
73     return nullptr;
74   }
75 }
76 
77 void ObjCLanguage::MethodName::Clear() {
78   m_full.Clear();
79   m_class.Clear();
80   m_category.Clear();
81   m_selector.Clear();
82   m_type = eTypeUnspecified;
83   m_category_is_valid = false;
84 }
85 
86 bool ObjCLanguage::MethodName::SetName(llvm::StringRef name, bool strict) {
87   Clear();
88   if (name.empty())
89     return IsValid(strict);
90 
91   // If "strict" is true. then the method must be specified with a
92   // '+' or '-' at the beginning. If "strict" is false, then the '+'
93   // or '-' can be omitted
94   bool valid_prefix = false;
95 
96   if (name[0] == '+' || name[0] == '-') {
97     valid_prefix = name[1] == '[';
98     if (name[0] == '+')
99       m_type = eTypeClassMethod;
100     else
101       m_type = eTypeInstanceMethod;
102   } else if (!strict) {
103     // "strict" is false, the name just needs to start with '['
104     valid_prefix = name[0] == '[';
105   }
106 
107   if (valid_prefix) {
108     int name_len = name.size();
109     // Objective C methods must have at least:
110     //      "-[" or "+[" prefix
111     //      One character for a class name
112     //      One character for the space between the class name
113     //      One character for the method name
114     //      "]" suffix
115     if (name_len >= (5 + (strict ? 1 : 0)) && name.back() == ']') {
116       m_full.SetString(name);
117     }
118   }
119   return IsValid(strict);
120 }
121 
122 bool ObjCLanguage::MethodName::SetName(const char *name, bool strict) {
123   return SetName(llvm::StringRef(name), strict);
124 }
125 
126 const ConstString &ObjCLanguage::MethodName::GetClassName() {
127   if (!m_class) {
128     if (IsValid(false)) {
129       const char *full = m_full.GetCString();
130       const char *class_start = (full[0] == '[' ? full + 1 : full + 2);
131       const char *paren_pos = strchr(class_start, '(');
132       if (paren_pos) {
133         m_class.SetCStringWithLength(class_start, paren_pos - class_start);
134       } else {
135         // No '(' was found in the full name, we can definitively say
136         // that our category was valid (and empty).
137         m_category_is_valid = true;
138         const char *space_pos = strchr(full, ' ');
139         if (space_pos) {
140           m_class.SetCStringWithLength(class_start, space_pos - class_start);
141           if (!m_class_category) {
142             // No category in name, so we can also fill in the m_class_category
143             m_class_category = m_class;
144           }
145         }
146       }
147     }
148   }
149   return m_class;
150 }
151 
152 const ConstString &ObjCLanguage::MethodName::GetClassNameWithCategory() {
153   if (!m_class_category) {
154     if (IsValid(false)) {
155       const char *full = m_full.GetCString();
156       const char *class_start = (full[0] == '[' ? full + 1 : full + 2);
157       const char *space_pos = strchr(full, ' ');
158       if (space_pos) {
159         m_class_category.SetCStringWithLength(class_start,
160                                               space_pos - class_start);
161         // If m_class hasn't been filled in and the class with category doesn't
162         // contain a '(', then we can also fill in the m_class
163         if (!m_class && strchr(m_class_category.GetCString(), '(') == nullptr) {
164           m_class = m_class_category;
165           // No '(' was found in the full name, we can definitively say
166           // that our category was valid (and empty).
167           m_category_is_valid = true;
168         }
169       }
170     }
171   }
172   return m_class_category;
173 }
174 
175 const ConstString &ObjCLanguage::MethodName::GetSelector() {
176   if (!m_selector) {
177     if (IsValid(false)) {
178       const char *full = m_full.GetCString();
179       const char *space_pos = strchr(full, ' ');
180       if (space_pos) {
181         ++space_pos; // skip the space
182         m_selector.SetCStringWithLength(space_pos, m_full.GetLength() -
183                                                        (space_pos - full) - 1);
184       }
185     }
186   }
187   return m_selector;
188 }
189 
190 const ConstString &ObjCLanguage::MethodName::GetCategory() {
191   if (!m_category_is_valid && !m_category) {
192     if (IsValid(false)) {
193       m_category_is_valid = true;
194       const char *full = m_full.GetCString();
195       const char *class_start = (full[0] == '[' ? full + 1 : full + 2);
196       const char *open_paren_pos = strchr(class_start, '(');
197       if (open_paren_pos) {
198         ++open_paren_pos; // Skip the open paren
199         const char *close_paren_pos = strchr(open_paren_pos, ')');
200         if (close_paren_pos)
201           m_category.SetCStringWithLength(open_paren_pos,
202                                           close_paren_pos - open_paren_pos);
203       }
204     }
205   }
206   return m_category;
207 }
208 
209 ConstString ObjCLanguage::MethodName::GetFullNameWithoutCategory(
210     bool empty_if_no_category) {
211   if (IsValid(false)) {
212     if (HasCategory()) {
213       StreamString strm;
214       if (m_type == eTypeClassMethod)
215         strm.PutChar('+');
216       else if (m_type == eTypeInstanceMethod)
217         strm.PutChar('-');
218       strm.Printf("[%s %s]", GetClassName().GetCString(),
219                   GetSelector().GetCString());
220       return ConstString(strm.GetString().c_str());
221     }
222 
223     if (!empty_if_no_category) {
224       // Just return the full name since it doesn't have a category
225       return GetFullName();
226     }
227   }
228   return ConstString();
229 }
230 
231 size_t ObjCLanguage::MethodName::GetFullNames(std::vector<ConstString> &names,
232                                               bool append) {
233   if (!append)
234     names.clear();
235   if (IsValid(false)) {
236     StreamString strm;
237     const bool is_class_method = m_type == eTypeClassMethod;
238     const bool is_instance_method = m_type == eTypeInstanceMethod;
239     const ConstString &category = GetCategory();
240     if (is_class_method || is_instance_method) {
241       names.push_back(m_full);
242       if (category) {
243         strm.Printf("%c[%s %s]", is_class_method ? '+' : '-',
244                     GetClassName().GetCString(), GetSelector().GetCString());
245         names.push_back(ConstString(strm.GetString().c_str()));
246       }
247     } else {
248       const ConstString &class_name = GetClassName();
249       const ConstString &selector = GetSelector();
250       strm.Printf("+[%s %s]", class_name.GetCString(), selector.GetCString());
251       names.push_back(ConstString(strm.GetString().c_str()));
252       strm.Clear();
253       strm.Printf("-[%s %s]", class_name.GetCString(), selector.GetCString());
254       names.push_back(ConstString(strm.GetString().c_str()));
255       strm.Clear();
256       if (category) {
257         strm.Printf("+[%s(%s) %s]", class_name.GetCString(),
258                     category.GetCString(), selector.GetCString());
259         names.push_back(ConstString(strm.GetString().c_str()));
260         strm.Clear();
261         strm.Printf("-[%s(%s) %s]", class_name.GetCString(),
262                     category.GetCString(), selector.GetCString());
263         names.push_back(ConstString(strm.GetString().c_str()));
264       }
265     }
266   }
267   return names.size();
268 }
269 
270 static void LoadObjCFormatters(TypeCategoryImplSP objc_category_sp) {
271   if (!objc_category_sp)
272     return;
273 
274   TypeSummaryImpl::Flags objc_flags;
275   objc_flags.SetCascades(false)
276       .SetSkipPointers(true)
277       .SetSkipReferences(true)
278       .SetDontShowChildren(true)
279       .SetDontShowValue(true)
280       .SetShowMembersOneLiner(false)
281       .SetHideItemNames(false);
282 
283   lldb::TypeSummaryImplSP ObjC_BOOL_summary(new CXXFunctionSummaryFormat(
284       objc_flags, lldb_private::formatters::ObjCBOOLSummaryProvider, ""));
285   objc_category_sp->GetTypeSummariesContainer()->Add(ConstString("BOOL"),
286                                                      ObjC_BOOL_summary);
287   objc_category_sp->GetTypeSummariesContainer()->Add(ConstString("BOOL &"),
288                                                      ObjC_BOOL_summary);
289   objc_category_sp->GetTypeSummariesContainer()->Add(ConstString("BOOL *"),
290                                                      ObjC_BOOL_summary);
291 
292 #ifndef LLDB_DISABLE_PYTHON
293   // we need to skip pointers here since we are special casing a SEL* when
294   // retrieving its value
295   objc_flags.SetSkipPointers(true);
296   AddCXXSummary(objc_category_sp,
297                 lldb_private::formatters::ObjCSELSummaryProvider<false>,
298                 "SEL summary provider", ConstString("SEL"), objc_flags);
299   AddCXXSummary(
300       objc_category_sp, lldb_private::formatters::ObjCSELSummaryProvider<false>,
301       "SEL summary provider", ConstString("struct objc_selector"), objc_flags);
302   AddCXXSummary(
303       objc_category_sp, lldb_private::formatters::ObjCSELSummaryProvider<false>,
304       "SEL summary provider", ConstString("objc_selector"), objc_flags);
305   AddCXXSummary(
306       objc_category_sp, lldb_private::formatters::ObjCSELSummaryProvider<true>,
307       "SEL summary provider", ConstString("objc_selector *"), objc_flags);
308   AddCXXSummary(objc_category_sp,
309                 lldb_private::formatters::ObjCSELSummaryProvider<true>,
310                 "SEL summary provider", ConstString("SEL *"), objc_flags);
311 
312   AddCXXSummary(objc_category_sp,
313                 lldb_private::formatters::ObjCClassSummaryProvider,
314                 "Class summary provider", ConstString("Class"), objc_flags);
315 
316   SyntheticChildren::Flags class_synth_flags;
317   class_synth_flags.SetCascades(true).SetSkipPointers(false).SetSkipReferences(
318       false);
319 
320   AddCXXSynthetic(objc_category_sp,
321                   lldb_private::formatters::ObjCClassSyntheticFrontEndCreator,
322                   "Class synthetic children", ConstString("Class"),
323                   class_synth_flags);
324 #endif // LLDB_DISABLE_PYTHON
325 
326   objc_flags.SetSkipPointers(false);
327   objc_flags.SetCascades(true);
328   objc_flags.SetSkipReferences(false);
329 
330   AddStringSummary(objc_category_sp, "${var.__FuncPtr%A}",
331                    ConstString("__block_literal_generic"), objc_flags);
332 
333   AddStringSummary(objc_category_sp, "${var.years} years, ${var.months} "
334                                      "months, ${var.days} days, ${var.hours} "
335                                      "hours, ${var.minutes} minutes "
336                                      "${var.seconds} seconds",
337                    ConstString("CFGregorianUnits"), objc_flags);
338   AddStringSummary(objc_category_sp,
339                    "location=${var.location} length=${var.length}",
340                    ConstString("CFRange"), objc_flags);
341 
342   AddStringSummary(objc_category_sp,
343                    "location=${var.location}, length=${var.length}",
344                    ConstString("NSRange"), objc_flags);
345   AddStringSummary(objc_category_sp, "(${var.origin}, ${var.size}), ...",
346                    ConstString("NSRectArray"), objc_flags);
347 
348   AddOneLineSummary(objc_category_sp, ConstString("NSPoint"), objc_flags);
349   AddOneLineSummary(objc_category_sp, ConstString("NSSize"), objc_flags);
350   AddOneLineSummary(objc_category_sp, ConstString("NSRect"), objc_flags);
351 
352   AddOneLineSummary(objc_category_sp, ConstString("CGSize"), objc_flags);
353   AddOneLineSummary(objc_category_sp, ConstString("CGPoint"), objc_flags);
354   AddOneLineSummary(objc_category_sp, ConstString("CGRect"), objc_flags);
355 
356   AddStringSummary(objc_category_sp,
357                    "red=${var.red} green=${var.green} blue=${var.blue}",
358                    ConstString("RGBColor"), objc_flags);
359   AddStringSummary(
360       objc_category_sp,
361       "(t=${var.top}, l=${var.left}, b=${var.bottom}, r=${var.right})",
362       ConstString("Rect"), objc_flags);
363   AddStringSummary(objc_category_sp, "{(v=${var.v}, h=${var.h})}",
364                    ConstString("Point"), objc_flags);
365   AddStringSummary(objc_category_sp,
366                    "${var.month}/${var.day}/${var.year}  ${var.hour} "
367                    ":${var.minute} :${var.second} dayOfWeek:${var.dayOfWeek}",
368                    ConstString("DateTimeRect *"), objc_flags);
369   AddStringSummary(objc_category_sp, "${var.ld.month}/${var.ld.day}/"
370                                      "${var.ld.year} ${var.ld.hour} "
371                                      ":${var.ld.minute} :${var.ld.second} "
372                                      "dayOfWeek:${var.ld.dayOfWeek}",
373                    ConstString("LongDateRect"), objc_flags);
374   AddStringSummary(objc_category_sp, "(x=${var.x}, y=${var.y})",
375                    ConstString("HIPoint"), objc_flags);
376   AddStringSummary(objc_category_sp, "origin=${var.origin} size=${var.size}",
377                    ConstString("HIRect"), objc_flags);
378 
379   TypeSummaryImpl::Flags appkit_flags;
380   appkit_flags.SetCascades(true)
381       .SetSkipPointers(false)
382       .SetSkipReferences(false)
383       .SetDontShowChildren(true)
384       .SetDontShowValue(false)
385       .SetShowMembersOneLiner(false)
386       .SetHideItemNames(false);
387 
388   appkit_flags.SetDontShowChildren(false);
389 
390 #ifndef LLDB_DISABLE_PYTHON
391   AddCXXSummary(
392       objc_category_sp, lldb_private::formatters::NSArraySummaryProvider,
393       "NSArray summary provider", ConstString("NSArray"), appkit_flags);
394   AddCXXSummary(
395       objc_category_sp, lldb_private::formatters::NSArraySummaryProvider,
396       "NSArray summary provider", ConstString("NSMutableArray"), appkit_flags);
397   AddCXXSummary(
398       objc_category_sp, lldb_private::formatters::NSArraySummaryProvider,
399       "NSArray summary provider", ConstString("__NSArrayI"), appkit_flags);
400   AddCXXSummary(
401       objc_category_sp, lldb_private::formatters::NSArraySummaryProvider,
402       "NSArray summary provider", ConstString("__NSArray0"), appkit_flags);
403   AddCXXSummary(objc_category_sp,
404                 lldb_private::formatters::NSArraySummaryProvider,
405                 "NSArray summary provider",
406                 ConstString("__NSSingleObjectArrayI"), appkit_flags);
407   AddCXXSummary(
408       objc_category_sp, lldb_private::formatters::NSArraySummaryProvider,
409       "NSArray summary provider", ConstString("__NSArrayM"), appkit_flags);
410   AddCXXSummary(
411       objc_category_sp, lldb_private::formatters::NSArraySummaryProvider,
412       "NSArray summary provider", ConstString("__NSCFArray"), appkit_flags);
413   AddCXXSummary(
414       objc_category_sp, lldb_private::formatters::NSArraySummaryProvider,
415       "NSArray summary provider", ConstString("CFArrayRef"), appkit_flags);
416   AddCXXSummary(objc_category_sp,
417                 lldb_private::formatters::NSArraySummaryProvider,
418                 "NSArray summary provider", ConstString("CFMutableArrayRef"),
419                 appkit_flags);
420 
421   AddCXXSummary(objc_category_sp,
422                 lldb_private::formatters::NSDictionarySummaryProvider<false>,
423                 "NSDictionary summary provider", ConstString("NSDictionary"),
424                 appkit_flags);
425   AddCXXSummary(objc_category_sp,
426                 lldb_private::formatters::NSDictionarySummaryProvider<false>,
427                 "NSDictionary summary provider",
428                 ConstString("NSMutableDictionary"), appkit_flags);
429   AddCXXSummary(objc_category_sp,
430                 lldb_private::formatters::NSDictionarySummaryProvider<false>,
431                 "NSDictionary summary provider",
432                 ConstString("__NSCFDictionary"), appkit_flags);
433   AddCXXSummary(objc_category_sp,
434                 lldb_private::formatters::NSDictionarySummaryProvider<false>,
435                 "NSDictionary summary provider", ConstString("__NSDictionaryI"),
436                 appkit_flags);
437   AddCXXSummary(objc_category_sp,
438                 lldb_private::formatters::NSDictionarySummaryProvider<false>,
439                 "NSDictionary summary provider",
440                 ConstString("__NSSingleEntryDictionaryI"), appkit_flags);
441   AddCXXSummary(objc_category_sp,
442                 lldb_private::formatters::NSDictionarySummaryProvider<false>,
443                 "NSDictionary summary provider", ConstString("__NSDictionaryM"),
444                 appkit_flags);
445   AddCXXSummary(objc_category_sp,
446                 lldb_private::formatters::NSDictionarySummaryProvider<true>,
447                 "NSDictionary summary provider", ConstString("CFDictionaryRef"),
448                 appkit_flags);
449   AddCXXSummary(objc_category_sp,
450                 lldb_private::formatters::NSDictionarySummaryProvider<true>,
451                 "NSDictionary summary provider",
452                 ConstString("CFMutableDictionaryRef"), appkit_flags);
453 
454   AddCXXSummary(objc_category_sp,
455                 lldb_private::formatters::NSSetSummaryProvider<false>,
456                 "NSSet summary", ConstString("NSSet"), appkit_flags);
457   AddCXXSummary(
458       objc_category_sp, lldb_private::formatters::NSSetSummaryProvider<false>,
459       "NSMutableSet summary", ConstString("NSMutableSet"), appkit_flags);
460   AddCXXSummary(objc_category_sp,
461                 lldb_private::formatters::NSSetSummaryProvider<true>,
462                 "CFSetRef summary", ConstString("CFSetRef"), appkit_flags);
463   AddCXXSummary(
464       objc_category_sp, lldb_private::formatters::NSSetSummaryProvider<true>,
465       "CFMutableSetRef summary", ConstString("CFMutableSetRef"), appkit_flags);
466   AddCXXSummary(objc_category_sp,
467                 lldb_private::formatters::NSSetSummaryProvider<false>,
468                 "__NSCFSet summary", ConstString("__NSCFSet"), appkit_flags);
469   AddCXXSummary(objc_category_sp,
470                 lldb_private::formatters::NSSetSummaryProvider<false>,
471                 "__NSSetI summary", ConstString("__NSSetI"), appkit_flags);
472   AddCXXSummary(objc_category_sp,
473                 lldb_private::formatters::NSSetSummaryProvider<false>,
474                 "__NSSetM summary", ConstString("__NSSetM"), appkit_flags);
475   AddCXXSummary(
476       objc_category_sp, lldb_private::formatters::NSSetSummaryProvider<false>,
477       "NSCountedSet summary", ConstString("NSCountedSet"), appkit_flags);
478   AddCXXSummary(
479       objc_category_sp, lldb_private::formatters::NSSetSummaryProvider<false>,
480       "NSMutableSet summary", ConstString("NSMutableSet"), appkit_flags);
481   AddCXXSummary(
482       objc_category_sp, lldb_private::formatters::NSSetSummaryProvider<false>,
483       "NSOrderedSet summary", ConstString("NSOrderedSet"), appkit_flags);
484   AddCXXSummary(
485       objc_category_sp, lldb_private::formatters::NSSetSummaryProvider<false>,
486       "__NSOrderedSetI summary", ConstString("__NSOrderedSetI"), appkit_flags);
487   AddCXXSummary(
488       objc_category_sp, lldb_private::formatters::NSSetSummaryProvider<false>,
489       "__NSOrderedSetM summary", ConstString("__NSOrderedSetM"), appkit_flags);
490 
491   AddCXXSummary(
492       objc_category_sp, lldb_private::formatters::NSError_SummaryProvider,
493       "NSError summary provider", ConstString("NSError"), appkit_flags);
494   AddCXXSummary(
495       objc_category_sp, lldb_private::formatters::NSException_SummaryProvider,
496       "NSException summary provider", ConstString("NSException"), appkit_flags);
497 
498   // AddSummary(appkit_category_sp, "${var.key%@} -> ${var.value%@}",
499   // ConstString("$_lldb_typegen_nspair"), appkit_flags);
500 
501   appkit_flags.SetDontShowChildren(true);
502 
503   AddCXXSynthetic(objc_category_sp,
504                   lldb_private::formatters::NSArraySyntheticFrontEndCreator,
505                   "NSArray synthetic children", ConstString("__NSArrayM"),
506                   ScriptedSyntheticChildren::Flags());
507   AddCXXSynthetic(objc_category_sp,
508                   lldb_private::formatters::NSArraySyntheticFrontEndCreator,
509                   "NSArray synthetic children", ConstString("__NSArrayI"),
510                   ScriptedSyntheticChildren::Flags());
511   AddCXXSynthetic(objc_category_sp,
512                   lldb_private::formatters::NSArraySyntheticFrontEndCreator,
513                   "NSArray synthetic children", ConstString("__NSArray0"),
514                   ScriptedSyntheticChildren::Flags());
515   AddCXXSynthetic(objc_category_sp,
516                   lldb_private::formatters::NSArraySyntheticFrontEndCreator,
517                   "NSArray synthetic children",
518                   ConstString("__NSSingleObjectArrayI"),
519                   ScriptedSyntheticChildren::Flags());
520   AddCXXSynthetic(objc_category_sp,
521                   lldb_private::formatters::NSArraySyntheticFrontEndCreator,
522                   "NSArray synthetic children", ConstString("NSArray"),
523                   ScriptedSyntheticChildren::Flags());
524   AddCXXSynthetic(objc_category_sp,
525                   lldb_private::formatters::NSArraySyntheticFrontEndCreator,
526                   "NSArray synthetic children", ConstString("NSMutableArray"),
527                   ScriptedSyntheticChildren::Flags());
528   AddCXXSynthetic(objc_category_sp,
529                   lldb_private::formatters::NSArraySyntheticFrontEndCreator,
530                   "NSArray synthetic children", ConstString("__NSCFArray"),
531                   ScriptedSyntheticChildren::Flags());
532   AddCXXSynthetic(objc_category_sp,
533                   lldb_private::formatters::NSArraySyntheticFrontEndCreator,
534                   "NSArray synthetic children",
535                   ConstString("CFMutableArrayRef"),
536                   ScriptedSyntheticChildren::Flags());
537   AddCXXSynthetic(objc_category_sp,
538                   lldb_private::formatters::NSArraySyntheticFrontEndCreator,
539                   "NSArray synthetic children", ConstString("CFArrayRef"),
540                   ScriptedSyntheticChildren::Flags());
541 
542   AddCXXSynthetic(
543       objc_category_sp,
544       lldb_private::formatters::NSDictionarySyntheticFrontEndCreator,
545       "NSDictionary synthetic children", ConstString("__NSDictionaryM"),
546       ScriptedSyntheticChildren::Flags());
547   AddCXXSynthetic(
548       objc_category_sp,
549       lldb_private::formatters::NSDictionarySyntheticFrontEndCreator,
550       "NSDictionary synthetic children", ConstString("__NSDictionaryI"),
551       ScriptedSyntheticChildren::Flags());
552   AddCXXSynthetic(
553       objc_category_sp,
554       lldb_private::formatters::NSDictionarySyntheticFrontEndCreator,
555       "NSDictionary synthetic children",
556       ConstString("__NSSingleEntryDictionaryI"),
557       ScriptedSyntheticChildren::Flags());
558   AddCXXSynthetic(
559       objc_category_sp,
560       lldb_private::formatters::NSDictionarySyntheticFrontEndCreator,
561       "NSDictionary synthetic children", ConstString("__NSCFDictionary"),
562       ScriptedSyntheticChildren::Flags());
563   AddCXXSynthetic(
564       objc_category_sp,
565       lldb_private::formatters::NSDictionarySyntheticFrontEndCreator,
566       "NSDictionary synthetic children", ConstString("NSDictionary"),
567       ScriptedSyntheticChildren::Flags());
568   AddCXXSynthetic(
569       objc_category_sp,
570       lldb_private::formatters::NSDictionarySyntheticFrontEndCreator,
571       "NSDictionary synthetic children", ConstString("NSMutableDictionary"),
572       ScriptedSyntheticChildren::Flags());
573   AddCXXSynthetic(
574       objc_category_sp,
575       lldb_private::formatters::NSDictionarySyntheticFrontEndCreator,
576       "NSDictionary synthetic children", ConstString("CFDictionaryRef"),
577       ScriptedSyntheticChildren::Flags());
578   AddCXXSynthetic(
579       objc_category_sp,
580       lldb_private::formatters::NSDictionarySyntheticFrontEndCreator,
581       "NSDictionary synthetic children", ConstString("CFMutableDictionaryRef"),
582       ScriptedSyntheticChildren::Flags());
583 
584   AddCXXSynthetic(objc_category_sp,
585                   lldb_private::formatters::NSErrorSyntheticFrontEndCreator,
586                   "NSError synthetic children", ConstString("NSError"),
587                   ScriptedSyntheticChildren::Flags());
588   AddCXXSynthetic(objc_category_sp,
589                   lldb_private::formatters::NSExceptionSyntheticFrontEndCreator,
590                   "NSException synthetic children", ConstString("NSException"),
591                   ScriptedSyntheticChildren::Flags());
592 
593   AddCXXSynthetic(objc_category_sp,
594                   lldb_private::formatters::NSSetSyntheticFrontEndCreator,
595                   "NSSet synthetic children", ConstString("NSSet"),
596                   ScriptedSyntheticChildren::Flags());
597   AddCXXSynthetic(objc_category_sp,
598                   lldb_private::formatters::NSSetSyntheticFrontEndCreator,
599                   "__NSSetI synthetic children", ConstString("__NSSetI"),
600                   ScriptedSyntheticChildren::Flags());
601   AddCXXSynthetic(objc_category_sp,
602                   lldb_private::formatters::NSSetSyntheticFrontEndCreator,
603                   "__NSSetM synthetic children", ConstString("__NSSetM"),
604                   ScriptedSyntheticChildren::Flags());
605   AddCXXSynthetic(
606       objc_category_sp, lldb_private::formatters::NSSetSyntheticFrontEndCreator,
607       "NSMutableSet synthetic children", ConstString("NSMutableSet"),
608       ScriptedSyntheticChildren::Flags());
609   AddCXXSynthetic(
610       objc_category_sp, lldb_private::formatters::NSSetSyntheticFrontEndCreator,
611       "NSOrderedSet synthetic children", ConstString("NSOrderedSet"),
612       ScriptedSyntheticChildren::Flags());
613   AddCXXSynthetic(
614       objc_category_sp, lldb_private::formatters::NSSetSyntheticFrontEndCreator,
615       "__NSOrderedSetI synthetic children", ConstString("__NSOrderedSetI"),
616       ScriptedSyntheticChildren::Flags());
617   AddCXXSynthetic(
618       objc_category_sp, lldb_private::formatters::NSSetSyntheticFrontEndCreator,
619       "__NSOrderedSetM synthetic children", ConstString("__NSOrderedSetM"),
620       ScriptedSyntheticChildren::Flags());
621 
622   AddCXXSynthetic(objc_category_sp,
623                   lldb_private::formatters::NSIndexPathSyntheticFrontEndCreator,
624                   "NSIndexPath synthetic children", ConstString("NSIndexPath"),
625                   ScriptedSyntheticChildren::Flags());
626 
627   AddCXXSummary(
628       objc_category_sp, lldb_private::formatters::CFBagSummaryProvider,
629       "CFBag summary provider", ConstString("CFBagRef"), appkit_flags);
630   AddCXXSummary(objc_category_sp,
631                 lldb_private::formatters::CFBagSummaryProvider,
632                 "CFBag summary provider", ConstString("__CFBag"), appkit_flags);
633   AddCXXSummary(objc_category_sp,
634                 lldb_private::formatters::CFBagSummaryProvider,
635                 "CFBag summary provider", ConstString("const struct __CFBag"),
636                 appkit_flags);
637   AddCXXSummary(
638       objc_category_sp, lldb_private::formatters::CFBagSummaryProvider,
639       "CFBag summary provider", ConstString("CFMutableBagRef"), appkit_flags);
640 
641   AddCXXSummary(objc_category_sp,
642                 lldb_private::formatters::CFBinaryHeapSummaryProvider,
643                 "CFBinaryHeap summary provider", ConstString("CFBinaryHeapRef"),
644                 appkit_flags);
645   AddCXXSummary(objc_category_sp,
646                 lldb_private::formatters::CFBinaryHeapSummaryProvider,
647                 "CFBinaryHeap summary provider", ConstString("__CFBinaryHeap"),
648                 appkit_flags);
649 
650   AddCXXSummary(
651       objc_category_sp, lldb_private::formatters::NSStringSummaryProvider,
652       "NSString summary provider", ConstString("NSString"), appkit_flags);
653   AddCXXSummary(
654       objc_category_sp, lldb_private::formatters::NSStringSummaryProvider,
655       "NSString summary provider", ConstString("CFStringRef"), appkit_flags);
656   AddCXXSummary(
657       objc_category_sp, lldb_private::formatters::NSStringSummaryProvider,
658       "NSString summary provider", ConstString("__CFString"), appkit_flags);
659   AddCXXSummary(objc_category_sp,
660                 lldb_private::formatters::NSStringSummaryProvider,
661                 "NSString summary provider", ConstString("CFMutableStringRef"),
662                 appkit_flags);
663   AddCXXSummary(objc_category_sp,
664                 lldb_private::formatters::NSStringSummaryProvider,
665                 "NSString summary provider", ConstString("NSMutableString"),
666                 appkit_flags);
667   AddCXXSummary(objc_category_sp,
668                 lldb_private::formatters::NSStringSummaryProvider,
669                 "NSString summary provider",
670                 ConstString("__NSCFConstantString"), appkit_flags);
671   AddCXXSummary(
672       objc_category_sp, lldb_private::formatters::NSStringSummaryProvider,
673       "NSString summary provider", ConstString("__NSCFString"), appkit_flags);
674   AddCXXSummary(objc_category_sp,
675                 lldb_private::formatters::NSStringSummaryProvider,
676                 "NSString summary provider", ConstString("NSCFConstantString"),
677                 appkit_flags);
678   AddCXXSummary(
679       objc_category_sp, lldb_private::formatters::NSStringSummaryProvider,
680       "NSString summary provider", ConstString("NSCFString"), appkit_flags);
681   AddCXXSummary(
682       objc_category_sp, lldb_private::formatters::NSStringSummaryProvider,
683       "NSString summary provider", ConstString("NSPathStore2"), appkit_flags);
684   AddCXXSummary(objc_category_sp,
685                 lldb_private::formatters::NSStringSummaryProvider,
686                 "NSString summary provider",
687                 ConstString("NSTaggedPointerString"), appkit_flags);
688 
689   AddCXXSummary(objc_category_sp,
690                 lldb_private::formatters::NSAttributedStringSummaryProvider,
691                 "NSAttributedString summary provider",
692                 ConstString("NSAttributedString"), appkit_flags);
693   AddCXXSummary(
694       objc_category_sp,
695       lldb_private::formatters::NSMutableAttributedStringSummaryProvider,
696       "NSMutableAttributedString summary provider",
697       ConstString("NSMutableAttributedString"), appkit_flags);
698   AddCXXSummary(
699       objc_category_sp,
700       lldb_private::formatters::NSMutableAttributedStringSummaryProvider,
701       "NSMutableAttributedString summary provider",
702       ConstString("NSConcreteMutableAttributedString"), appkit_flags);
703 
704   AddCXXSummary(
705       objc_category_sp, lldb_private::formatters::NSBundleSummaryProvider,
706       "NSBundle summary provider", ConstString("NSBundle"), appkit_flags);
707 
708   AddCXXSummary(objc_category_sp,
709                 lldb_private::formatters::NSDataSummaryProvider<false>,
710                 "NSData summary provider", ConstString("NSData"), appkit_flags);
711   AddCXXSummary(
712       objc_category_sp, lldb_private::formatters::NSDataSummaryProvider<false>,
713       "NSData summary provider", ConstString("_NSInlineData"), appkit_flags);
714   AddCXXSummary(
715       objc_category_sp, lldb_private::formatters::NSDataSummaryProvider<false>,
716       "NSData summary provider", ConstString("NSConcreteData"), appkit_flags);
717   AddCXXSummary(objc_category_sp,
718                 lldb_private::formatters::NSDataSummaryProvider<false>,
719                 "NSData summary provider", ConstString("NSConcreteMutableData"),
720                 appkit_flags);
721   AddCXXSummary(
722       objc_category_sp, lldb_private::formatters::NSDataSummaryProvider<false>,
723       "NSData summary provider", ConstString("NSMutableData"), appkit_flags);
724   AddCXXSummary(
725       objc_category_sp, lldb_private::formatters::NSDataSummaryProvider<false>,
726       "NSData summary provider", ConstString("__NSCFData"), appkit_flags);
727   AddCXXSummary(
728       objc_category_sp, lldb_private::formatters::NSDataSummaryProvider<true>,
729       "NSData summary provider", ConstString("CFDataRef"), appkit_flags);
730   AddCXXSummary(
731       objc_category_sp, lldb_private::formatters::NSDataSummaryProvider<true>,
732       "NSData summary provider", ConstString("CFMutableDataRef"), appkit_flags);
733 
734   AddCXXSummary(
735       objc_category_sp, lldb_private::formatters::NSMachPortSummaryProvider,
736       "NSMachPort summary provider", ConstString("NSMachPort"), appkit_flags);
737 
738   AddCXXSummary(objc_category_sp,
739                 lldb_private::formatters::NSNotificationSummaryProvider,
740                 "NSNotification summary provider",
741                 ConstString("NSNotification"), appkit_flags);
742   AddCXXSummary(objc_category_sp,
743                 lldb_private::formatters::NSNotificationSummaryProvider,
744                 "NSNotification summary provider",
745                 ConstString("NSConcreteNotification"), appkit_flags);
746 
747   AddCXXSummary(
748       objc_category_sp, lldb_private::formatters::NSNumberSummaryProvider,
749       "NSNumber summary provider", ConstString("NSNumber"), appkit_flags);
750   AddCXXSummary(
751       objc_category_sp, lldb_private::formatters::NSNumberSummaryProvider,
752       "CFNumberRef summary provider", ConstString("CFNumberRef"), appkit_flags);
753   AddCXXSummary(
754       objc_category_sp, lldb_private::formatters::NSNumberSummaryProvider,
755       "NSNumber summary provider", ConstString("__NSCFBoolean"), appkit_flags);
756   AddCXXSummary(
757       objc_category_sp, lldb_private::formatters::NSNumberSummaryProvider,
758       "NSNumber summary provider", ConstString("__NSCFNumber"), appkit_flags);
759   AddCXXSummary(
760       objc_category_sp, lldb_private::formatters::NSNumberSummaryProvider,
761       "NSNumber summary provider", ConstString("NSCFBoolean"), appkit_flags);
762   AddCXXSummary(
763       objc_category_sp, lldb_private::formatters::NSNumberSummaryProvider,
764       "NSNumber summary provider", ConstString("NSCFNumber"), appkit_flags);
765 
766   AddCXXSummary(objc_category_sp,
767                 lldb_private::formatters::NSURLSummaryProvider,
768                 "NSURL summary provider", ConstString("NSURL"), appkit_flags);
769   AddCXXSummary(
770       objc_category_sp, lldb_private::formatters::NSURLSummaryProvider,
771       "NSURL summary provider", ConstString("CFURLRef"), appkit_flags);
772 
773   AddCXXSummary(objc_category_sp,
774                 lldb_private::formatters::NSDateSummaryProvider,
775                 "NSDate summary provider", ConstString("NSDate"), appkit_flags);
776   AddCXXSummary(
777       objc_category_sp, lldb_private::formatters::NSDateSummaryProvider,
778       "NSDate summary provider", ConstString("__NSDate"), appkit_flags);
779   AddCXXSummary(
780       objc_category_sp, lldb_private::formatters::NSDateSummaryProvider,
781       "NSDate summary provider", ConstString("__NSTaggedDate"), appkit_flags);
782   AddCXXSummary(
783       objc_category_sp, lldb_private::formatters::NSDateSummaryProvider,
784       "NSDate summary provider", ConstString("NSCalendarDate"), appkit_flags);
785 
786   AddCXXSummary(
787       objc_category_sp, lldb_private::formatters::NSTimeZoneSummaryProvider,
788       "NSTimeZone summary provider", ConstString("NSTimeZone"), appkit_flags);
789   AddCXXSummary(objc_category_sp,
790                 lldb_private::formatters::NSTimeZoneSummaryProvider,
791                 "NSTimeZone summary provider", ConstString("CFTimeZoneRef"),
792                 appkit_flags);
793   AddCXXSummary(
794       objc_category_sp, lldb_private::formatters::NSTimeZoneSummaryProvider,
795       "NSTimeZone summary provider", ConstString("__NSTimeZone"), appkit_flags);
796 
797   // CFAbsoluteTime is actually a double rather than a pointer to an object
798   // we do not care about the numeric value, since it is probably meaningless to
799   // users
800   appkit_flags.SetDontShowValue(true);
801   AddCXXSummary(objc_category_sp,
802                 lldb_private::formatters::CFAbsoluteTimeSummaryProvider,
803                 "CFAbsoluteTime summary provider",
804                 ConstString("CFAbsoluteTime"), appkit_flags);
805   appkit_flags.SetDontShowValue(false);
806 
807   AddCXXSummary(
808       objc_category_sp, lldb_private::formatters::NSIndexSetSummaryProvider,
809       "NSIndexSet summary provider", ConstString("NSIndexSet"), appkit_flags);
810   AddCXXSummary(objc_category_sp,
811                 lldb_private::formatters::NSIndexSetSummaryProvider,
812                 "NSIndexSet summary provider", ConstString("NSMutableIndexSet"),
813                 appkit_flags);
814 
815   AddStringSummary(objc_category_sp,
816                    "@\"${var.month%d}/${var.day%d}/${var.year%d} "
817                    "${var.hour%d}:${var.minute%d}:${var.second}\"",
818                    ConstString("CFGregorianDate"), appkit_flags);
819 
820   AddCXXSummary(objc_category_sp,
821                 lldb_private::formatters::CFBitVectorSummaryProvider,
822                 "CFBitVector summary provider", ConstString("CFBitVectorRef"),
823                 appkit_flags);
824   AddCXXSummary(objc_category_sp,
825                 lldb_private::formatters::CFBitVectorSummaryProvider,
826                 "CFBitVector summary provider",
827                 ConstString("CFMutableBitVectorRef"), appkit_flags);
828   AddCXXSummary(objc_category_sp,
829                 lldb_private::formatters::CFBitVectorSummaryProvider,
830                 "CFBitVector summary provider", ConstString("__CFBitVector"),
831                 appkit_flags);
832   AddCXXSummary(objc_category_sp,
833                 lldb_private::formatters::CFBitVectorSummaryProvider,
834                 "CFBitVector summary provider",
835                 ConstString("__CFMutableBitVector"), appkit_flags);
836 #endif // LLDB_DISABLE_PYTHON
837 }
838 
839 static void LoadCoreMediaFormatters(TypeCategoryImplSP objc_category_sp) {
840   if (!objc_category_sp)
841     return;
842 
843   TypeSummaryImpl::Flags cm_flags;
844   cm_flags.SetCascades(true)
845       .SetDontShowChildren(false)
846       .SetDontShowValue(false)
847       .SetHideItemNames(false)
848       .SetShowMembersOneLiner(false)
849       .SetSkipPointers(false)
850       .SetSkipReferences(false);
851 
852 #ifndef LLDB_DISABLE_PYTHON
853   AddCXXSummary(objc_category_sp,
854                 lldb_private::formatters::CMTimeSummaryProvider,
855                 "CMTime summary provider", ConstString("CMTime"), cm_flags);
856 #endif // LLDB_DISABLE_PYTHON
857 }
858 
859 lldb::TypeCategoryImplSP ObjCLanguage::GetFormatters() {
860   static std::once_flag g_initialize;
861   static TypeCategoryImplSP g_category;
862 
863   std::call_once(g_initialize, [this]() -> void {
864     DataVisualization::Categories::GetCategory(GetPluginName(), g_category);
865     if (g_category) {
866       LoadCoreMediaFormatters(g_category);
867       LoadObjCFormatters(g_category);
868     }
869   });
870   return g_category;
871 }
872 
873 std::vector<ConstString>
874 ObjCLanguage::GetPossibleFormattersMatches(ValueObject &valobj,
875                                            lldb::DynamicValueType use_dynamic) {
876   std::vector<ConstString> result;
877 
878   if (use_dynamic == lldb::eNoDynamicValues)
879     return result;
880 
881   CompilerType compiler_type(valobj.GetCompilerType());
882 
883   const bool check_cpp = false;
884   const bool check_objc = true;
885   bool canBeObjCDynamic =
886       compiler_type.IsPossibleDynamicType(nullptr, check_cpp, check_objc);
887 
888   if (canBeObjCDynamic) {
889     do {
890       lldb::ProcessSP process_sp = valobj.GetProcessSP();
891       if (!process_sp)
892         break;
893       ObjCLanguageRuntime *runtime = process_sp->GetObjCLanguageRuntime();
894       if (runtime == nullptr)
895         break;
896       ObjCLanguageRuntime::ClassDescriptorSP objc_class_sp(
897           runtime->GetClassDescriptor(valobj));
898       if (!objc_class_sp)
899         break;
900       if (ConstString name = objc_class_sp->GetClassName())
901         result.push_back(name);
902     } while (false);
903   }
904 
905   return result;
906 }
907 
908 std::unique_ptr<Language::TypeScavenger> ObjCLanguage::GetTypeScavenger() {
909   class ObjCTypeScavenger : public Language::TypeScavenger {
910   private:
911     class ObjCScavengerResult : public Language::TypeScavenger::Result {
912     public:
913       ObjCScavengerResult(CompilerType type)
914           : Language::TypeScavenger::Result(), m_compiler_type(type) {}
915 
916       bool IsValid() override { return m_compiler_type.IsValid(); }
917 
918       bool DumpToStream(Stream &stream, bool print_help_if_available) override {
919         if (IsValid()) {
920           m_compiler_type.DumpTypeDescription(&stream);
921           stream.EOL();
922           return true;
923         }
924         return false;
925       }
926 
927       ~ObjCScavengerResult() override = default;
928 
929     private:
930       CompilerType m_compiler_type;
931     };
932 
933   protected:
934     ObjCTypeScavenger() = default;
935 
936     ~ObjCTypeScavenger() override = default;
937 
938     bool Find_Impl(ExecutionContextScope *exe_scope, const char *key,
939                    ResultSet &results) override {
940       bool result = false;
941 
942       Target *target = exe_scope->CalculateTarget().get();
943       if (target) {
944         if (auto clang_modules_decl_vendor =
945                 target->GetClangModulesDeclVendor()) {
946           std::vector<clang::NamedDecl *> decls;
947           ConstString key_cs(key);
948 
949           if (clang_modules_decl_vendor->FindDecls(key_cs, false, UINT32_MAX,
950                                                    decls) > 0 &&
951               !decls.empty()) {
952             CompilerType module_type =
953                 ClangASTContext::GetTypeForDecl(decls.front());
954             result = true;
955             std::unique_ptr<Language::TypeScavenger::Result> result(
956                 new ObjCScavengerResult(module_type));
957             results.insert(std::move(result));
958           }
959         }
960       }
961 
962       if (!result) {
963         Process *process = exe_scope->CalculateProcess().get();
964         if (process) {
965           const bool create_on_demand = false;
966           auto objc_runtime = process->GetObjCLanguageRuntime(create_on_demand);
967           if (objc_runtime) {
968             auto decl_vendor = objc_runtime->GetDeclVendor();
969             if (decl_vendor) {
970               std::vector<clang::NamedDecl *> decls;
971               ConstString name(key);
972               decl_vendor->FindDecls(name, true, UINT32_MAX, decls);
973               for (auto decl : decls) {
974                 if (decl) {
975                   if (CompilerType candidate =
976                           ClangASTContext::GetTypeForDecl(decl)) {
977                     result = true;
978                     std::unique_ptr<Language::TypeScavenger::Result> result(
979                         new ObjCScavengerResult(candidate));
980                     results.insert(std::move(result));
981                   }
982                 }
983               }
984             }
985           }
986         }
987       }
988 
989       return result;
990     }
991 
992     friend class lldb_private::ObjCLanguage;
993   };
994 
995   return std::unique_ptr<TypeScavenger>(new ObjCTypeScavenger());
996 }
997 
998 bool ObjCLanguage::GetFormatterPrefixSuffix(ValueObject &valobj,
999                                             ConstString type_hint,
1000                                             std::string &prefix,
1001                                             std::string &suffix) {
1002   static ConstString g_CFBag("CFBag");
1003   static ConstString g_CFBinaryHeap("CFBinaryHeap");
1004 
1005   static ConstString g_NSNumberChar("NSNumber:char");
1006   static ConstString g_NSNumberShort("NSNumber:short");
1007   static ConstString g_NSNumberInt("NSNumber:int");
1008   static ConstString g_NSNumberLong("NSNumber:long");
1009   static ConstString g_NSNumberFloat("NSNumber:float");
1010   static ConstString g_NSNumberDouble("NSNumber:double");
1011 
1012   static ConstString g_NSData("NSData");
1013   static ConstString g_NSArray("NSArray");
1014   static ConstString g_NSString("NSString");
1015   static ConstString g_NSStringStar("NSString*");
1016 
1017   if (type_hint.IsEmpty())
1018     return false;
1019 
1020   prefix.clear();
1021   suffix.clear();
1022 
1023   if (type_hint == g_CFBag || type_hint == g_CFBinaryHeap) {
1024     prefix = "@";
1025     return true;
1026   }
1027 
1028   if (type_hint == g_NSNumberChar) {
1029     prefix = "(char)";
1030     return true;
1031   }
1032   if (type_hint == g_NSNumberShort) {
1033     prefix = "(short)";
1034     return true;
1035   }
1036   if (type_hint == g_NSNumberInt) {
1037     prefix = "(int)";
1038     return true;
1039   }
1040   if (type_hint == g_NSNumberLong) {
1041     prefix = "(long)";
1042     return true;
1043   }
1044   if (type_hint == g_NSNumberFloat) {
1045     prefix = "(float)";
1046     return true;
1047   }
1048   if (type_hint == g_NSNumberDouble) {
1049     prefix = "(double)";
1050     return true;
1051   }
1052 
1053   if (type_hint == g_NSData || type_hint == g_NSArray) {
1054     prefix = "@\"";
1055     suffix = "\"";
1056     return true;
1057   }
1058 
1059   if (type_hint == g_NSString || type_hint == g_NSStringStar) {
1060     prefix = "@";
1061     return true;
1062   }
1063 
1064   return false;
1065 }
1066 
1067 bool ObjCLanguage::IsNilReference(ValueObject &valobj) {
1068   const uint32_t mask = eTypeIsObjC | eTypeIsPointer;
1069   bool isObjCpointer =
1070       (((valobj.GetCompilerType().GetTypeInfo(nullptr)) & mask) == mask);
1071   if (!isObjCpointer)
1072     return false;
1073   bool canReadValue = true;
1074   bool isZero = valobj.GetValueAsUnsigned(0, &canReadValue) == 0;
1075   return canReadValue && isZero;
1076 }
1077