1 //===-- ValueObjectPrinter.cpp --------------------------------------------===//
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/DataFormatters/ValueObjectPrinter.h"
10 
11 #include "lldb/Core/ValueObject.h"
12 #include "lldb/DataFormatters/DataVisualization.h"
13 #include "lldb/Interpreter/CommandInterpreter.h"
14 #include "lldb/Target/Language.h"
15 #include "lldb/Target/Target.h"
16 #include "lldb/Utility/Stream.h"
17 
18 using namespace lldb;
19 using namespace lldb_private;
20 
ValueObjectPrinter(ValueObject * valobj,Stream * s)21 ValueObjectPrinter::ValueObjectPrinter(ValueObject *valobj, Stream *s) {
22   if (valobj) {
23     DumpValueObjectOptions options(*valobj);
24     Init(valobj, s, options, m_options.m_max_ptr_depth, 0, nullptr);
25   } else {
26     DumpValueObjectOptions options;
27     Init(valobj, s, options, m_options.m_max_ptr_depth, 0, nullptr);
28   }
29 }
30 
ValueObjectPrinter(ValueObject * valobj,Stream * s,const DumpValueObjectOptions & options)31 ValueObjectPrinter::ValueObjectPrinter(ValueObject *valobj, Stream *s,
32                                        const DumpValueObjectOptions &options) {
33   Init(valobj, s, options, m_options.m_max_ptr_depth, 0, nullptr);
34 }
35 
ValueObjectPrinter(ValueObject * valobj,Stream * s,const DumpValueObjectOptions & options,const DumpValueObjectOptions::PointerDepth & ptr_depth,uint32_t curr_depth,InstancePointersSetSP printed_instance_pointers)36 ValueObjectPrinter::ValueObjectPrinter(
37     ValueObject *valobj, Stream *s, const DumpValueObjectOptions &options,
38     const DumpValueObjectOptions::PointerDepth &ptr_depth, uint32_t curr_depth,
39     InstancePointersSetSP printed_instance_pointers) {
40   Init(valobj, s, options, ptr_depth, curr_depth, printed_instance_pointers);
41 }
42 
Init(ValueObject * valobj,Stream * s,const DumpValueObjectOptions & options,const DumpValueObjectOptions::PointerDepth & ptr_depth,uint32_t curr_depth,InstancePointersSetSP printed_instance_pointers)43 void ValueObjectPrinter::Init(
44     ValueObject *valobj, Stream *s, const DumpValueObjectOptions &options,
45     const DumpValueObjectOptions::PointerDepth &ptr_depth, uint32_t curr_depth,
46     InstancePointersSetSP printed_instance_pointers) {
47   m_orig_valobj = valobj;
48   m_valobj = nullptr;
49   m_stream = s;
50   m_options = options;
51   m_ptr_depth = ptr_depth;
52   m_curr_depth = curr_depth;
53   assert(m_orig_valobj && "cannot print a NULL ValueObject");
54   assert(m_stream && "cannot print to a NULL Stream");
55   m_should_print = eLazyBoolCalculate;
56   m_is_nil = eLazyBoolCalculate;
57   m_is_uninit = eLazyBoolCalculate;
58   m_is_ptr = eLazyBoolCalculate;
59   m_is_ref = eLazyBoolCalculate;
60   m_is_aggregate = eLazyBoolCalculate;
61   m_is_instance_ptr = eLazyBoolCalculate;
62   m_summary_formatter = {nullptr, false};
63   m_value.assign("");
64   m_summary.assign("");
65   m_error.assign("");
66   m_val_summary_ok = false;
67   m_printed_instance_pointers =
68       printed_instance_pointers
69           ? printed_instance_pointers
70           : InstancePointersSetSP(new InstancePointersSet());
71 }
72 
PrintValueObject()73 bool ValueObjectPrinter::PrintValueObject() {
74   if (!GetMostSpecializedValue() || m_valobj == nullptr)
75     return false;
76 
77   if (ShouldPrintValueObject()) {
78     PrintLocationIfNeeded();
79     m_stream->Indent();
80 
81     PrintDecl();
82   }
83 
84   bool value_printed = false;
85   bool summary_printed = false;
86 
87   m_val_summary_ok =
88       PrintValueAndSummaryIfNeeded(value_printed, summary_printed);
89 
90   if (m_val_summary_ok)
91     PrintChildrenIfNeeded(value_printed, summary_printed);
92   else
93     m_stream->EOL();
94 
95   return true;
96 }
97 
GetMostSpecializedValue()98 bool ValueObjectPrinter::GetMostSpecializedValue() {
99   if (m_valobj)
100     return true;
101   bool update_success = m_orig_valobj->UpdateValueIfNeeded(true);
102   if (!update_success) {
103     m_valobj = m_orig_valobj;
104   } else {
105     if (m_orig_valobj->IsDynamic()) {
106       if (m_options.m_use_dynamic == eNoDynamicValues) {
107         ValueObject *static_value = m_orig_valobj->GetStaticValue().get();
108         if (static_value)
109           m_valobj = static_value;
110         else
111           m_valobj = m_orig_valobj;
112       } else
113         m_valobj = m_orig_valobj;
114     } else {
115       if (m_options.m_use_dynamic != eNoDynamicValues) {
116         ValueObject *dynamic_value =
117             m_orig_valobj->GetDynamicValue(m_options.m_use_dynamic).get();
118         if (dynamic_value)
119           m_valobj = dynamic_value;
120         else
121           m_valobj = m_orig_valobj;
122       } else
123         m_valobj = m_orig_valobj;
124     }
125 
126     if (m_valobj->IsSynthetic()) {
127       if (!m_options.m_use_synthetic) {
128         ValueObject *non_synthetic = m_valobj->GetNonSyntheticValue().get();
129         if (non_synthetic)
130           m_valobj = non_synthetic;
131       }
132     } else {
133       if (m_options.m_use_synthetic) {
134         ValueObject *synthetic = m_valobj->GetSyntheticValue().get();
135         if (synthetic)
136           m_valobj = synthetic;
137       }
138     }
139   }
140   m_compiler_type = m_valobj->GetCompilerType();
141   m_type_flags = m_compiler_type.GetTypeInfo();
142   return true;
143 }
144 
GetDescriptionForDisplay()145 const char *ValueObjectPrinter::GetDescriptionForDisplay() {
146   const char *str = m_valobj->GetObjectDescription();
147   if (!str)
148     str = m_valobj->GetSummaryAsCString();
149   if (!str)
150     str = m_valobj->GetValueAsCString();
151   return str;
152 }
153 
GetRootNameForDisplay()154 const char *ValueObjectPrinter::GetRootNameForDisplay() {
155   const char *root_valobj_name = m_options.m_root_valobj_name.empty()
156                                      ? m_valobj->GetName().AsCString()
157                                      : m_options.m_root_valobj_name.c_str();
158   return root_valobj_name ? root_valobj_name : "";
159 }
160 
ShouldPrintValueObject()161 bool ValueObjectPrinter::ShouldPrintValueObject() {
162   if (m_should_print == eLazyBoolCalculate)
163     m_should_print =
164         (!m_options.m_flat_output || m_type_flags.Test(eTypeHasValue))
165             ? eLazyBoolYes
166             : eLazyBoolNo;
167   return m_should_print == eLazyBoolYes;
168 }
169 
IsNil()170 bool ValueObjectPrinter::IsNil() {
171   if (m_is_nil == eLazyBoolCalculate)
172     m_is_nil = m_valobj->IsNilReference() ? eLazyBoolYes : eLazyBoolNo;
173   return m_is_nil == eLazyBoolYes;
174 }
175 
IsUninitialized()176 bool ValueObjectPrinter::IsUninitialized() {
177   if (m_is_uninit == eLazyBoolCalculate)
178     m_is_uninit =
179         m_valobj->IsUninitializedReference() ? eLazyBoolYes : eLazyBoolNo;
180   return m_is_uninit == eLazyBoolYes;
181 }
182 
IsPtr()183 bool ValueObjectPrinter::IsPtr() {
184   if (m_is_ptr == eLazyBoolCalculate)
185     m_is_ptr = m_type_flags.Test(eTypeIsPointer) ? eLazyBoolYes : eLazyBoolNo;
186   return m_is_ptr == eLazyBoolYes;
187 }
188 
IsRef()189 bool ValueObjectPrinter::IsRef() {
190   if (m_is_ref == eLazyBoolCalculate)
191     m_is_ref = m_type_flags.Test(eTypeIsReference) ? eLazyBoolYes : eLazyBoolNo;
192   return m_is_ref == eLazyBoolYes;
193 }
194 
IsAggregate()195 bool ValueObjectPrinter::IsAggregate() {
196   if (m_is_aggregate == eLazyBoolCalculate)
197     m_is_aggregate =
198         m_type_flags.Test(eTypeHasChildren) ? eLazyBoolYes : eLazyBoolNo;
199   return m_is_aggregate == eLazyBoolYes;
200 }
201 
IsInstancePointer()202 bool ValueObjectPrinter::IsInstancePointer() {
203   // you need to do this check on the value's clang type
204   if (m_is_instance_ptr == eLazyBoolCalculate)
205     m_is_instance_ptr = (m_valobj->GetValue().GetCompilerType().GetTypeInfo() &
206                          eTypeInstanceIsPointer) != 0
207                             ? eLazyBoolYes
208                             : eLazyBoolNo;
209   if ((eLazyBoolYes == m_is_instance_ptr) && m_valobj->IsBaseClass())
210     m_is_instance_ptr = eLazyBoolNo;
211   return m_is_instance_ptr == eLazyBoolYes;
212 }
213 
PrintLocationIfNeeded()214 bool ValueObjectPrinter::PrintLocationIfNeeded() {
215   if (m_options.m_show_location) {
216     m_stream->Printf("%s: ", m_valobj->GetLocationAsCString());
217     return true;
218   }
219   return false;
220 }
221 
PrintDecl()222 void ValueObjectPrinter::PrintDecl() {
223   bool show_type = true;
224   // if we are at the root-level and been asked to hide the root's type, then
225   // hide it
226   if (m_curr_depth == 0 && m_options.m_hide_root_type)
227     show_type = false;
228   else
229     // otherwise decide according to the usual rules (asked to show types -
230     // always at the root level)
231     show_type = m_options.m_show_types ||
232                 (m_curr_depth == 0 && !m_options.m_flat_output);
233 
234   StreamString typeName;
235 
236   // always show the type at the root level if it is invalid
237   if (show_type) {
238     // Some ValueObjects don't have types (like registers sets). Only print the
239     // type if there is one to print
240     ConstString type_name;
241     if (m_compiler_type.IsValid()) {
242       type_name = m_options.m_use_type_display_name
243                       ? m_valobj->GetDisplayTypeName()
244                       : m_valobj->GetQualifiedTypeName();
245     } else {
246       // only show an invalid type name if the user explicitly triggered
247       // show_type
248       if (m_options.m_show_types)
249         type_name = ConstString("<invalid type>");
250     }
251 
252     if (type_name) {
253       std::string type_name_str(type_name.GetCString());
254       if (m_options.m_hide_pointer_value) {
255         for (auto iter = type_name_str.find(" *"); iter != std::string::npos;
256              iter = type_name_str.find(" *")) {
257           type_name_str.erase(iter, 2);
258         }
259       }
260       typeName << type_name_str.c_str();
261     }
262   }
263 
264   StreamString varName;
265 
266   if (!m_options.m_hide_name) {
267     if (m_options.m_flat_output)
268       m_valobj->GetExpressionPath(varName);
269     else
270       varName << GetRootNameForDisplay();
271   }
272 
273   bool decl_printed = false;
274   if (!m_options.m_decl_printing_helper) {
275     // if the user didn't give us a custom helper, pick one based upon the
276     // language, either the one that this printer is bound to, or the preferred
277     // one for the ValueObject
278     lldb::LanguageType lang_type =
279         (m_options.m_varformat_language == lldb::eLanguageTypeUnknown)
280             ? m_valobj->GetPreferredDisplayLanguage()
281             : m_options.m_varformat_language;
282     if (Language *lang_plugin = Language::FindPlugin(lang_type)) {
283       m_options.m_decl_printing_helper = lang_plugin->GetDeclPrintingHelper();
284     }
285   }
286 
287   if (m_options.m_decl_printing_helper) {
288     ConstString type_name_cstr(typeName.GetString());
289     ConstString var_name_cstr(varName.GetString());
290 
291     StreamString dest_stream;
292     if (m_options.m_decl_printing_helper(type_name_cstr, var_name_cstr,
293                                          m_options, dest_stream)) {
294       decl_printed = true;
295       m_stream->PutCString(dest_stream.GetString());
296     }
297   }
298 
299   // if the helper failed, or there is none, do a default thing
300   if (!decl_printed) {
301     if (!typeName.Empty())
302       m_stream->Printf("(%s) ", typeName.GetData());
303     if (!varName.Empty())
304       m_stream->Printf("%s =", varName.GetData());
305     else if (!m_options.m_hide_name)
306       m_stream->Printf(" =");
307   }
308 }
309 
CheckScopeIfNeeded()310 bool ValueObjectPrinter::CheckScopeIfNeeded() {
311   if (m_options.m_scope_already_checked)
312     return true;
313   return m_valobj->IsInScope();
314 }
315 
GetSummaryFormatter(bool null_if_omitted)316 TypeSummaryImpl *ValueObjectPrinter::GetSummaryFormatter(bool null_if_omitted) {
317   if (!m_summary_formatter.second) {
318     TypeSummaryImpl *entry = m_options.m_summary_sp
319                                  ? m_options.m_summary_sp.get()
320                                  : m_valobj->GetSummaryFormat().get();
321 
322     if (m_options.m_omit_summary_depth > 0)
323       entry = nullptr;
324     m_summary_formatter.first = entry;
325     m_summary_formatter.second = true;
326   }
327   if (m_options.m_omit_summary_depth > 0 && null_if_omitted)
328     return nullptr;
329   return m_summary_formatter.first;
330 }
331 
IsPointerValue(const CompilerType & type)332 static bool IsPointerValue(const CompilerType &type) {
333   Flags type_flags(type.GetTypeInfo());
334   if (type_flags.AnySet(eTypeInstanceIsPointer | eTypeIsPointer))
335     return type_flags.AllClear(eTypeIsBuiltIn);
336   return false;
337 }
338 
GetValueSummaryError(std::string & value,std::string & summary,std::string & error)339 void ValueObjectPrinter::GetValueSummaryError(std::string &value,
340                                               std::string &summary,
341                                               std::string &error) {
342   lldb::Format format = m_options.m_format;
343   // if I am printing synthetized elements, apply the format to those elements
344   // only
345   if (m_options.m_pointer_as_array)
346     m_valobj->GetValueAsCString(lldb::eFormatDefault, value);
347   else if (format != eFormatDefault && format != m_valobj->GetFormat())
348     m_valobj->GetValueAsCString(format, value);
349   else {
350     const char *val_cstr = m_valobj->GetValueAsCString();
351     if (val_cstr)
352       value.assign(val_cstr);
353   }
354   const char *err_cstr = m_valobj->GetError().AsCString();
355   if (err_cstr)
356     error.assign(err_cstr);
357 
358   if (!ShouldPrintValueObject())
359     return;
360 
361   if (IsNil()) {
362     lldb::LanguageType lang_type =
363         (m_options.m_varformat_language == lldb::eLanguageTypeUnknown)
364             ? m_valobj->GetPreferredDisplayLanguage()
365             : m_options.m_varformat_language;
366     if (Language *lang_plugin = Language::FindPlugin(lang_type)) {
367       summary.assign(lang_plugin->GetNilReferenceSummaryString().str());
368     } else {
369       // We treat C as the fallback language rather than as a separate Language
370       // plugin.
371       summary.assign("NULL");
372     }
373   } else if (IsUninitialized()) {
374     summary.assign("<uninitialized>");
375   } else if (m_options.m_omit_summary_depth == 0) {
376     TypeSummaryImpl *entry = GetSummaryFormatter();
377     if (entry) {
378       m_valobj->GetSummaryAsCString(entry, summary,
379                                     m_options.m_varformat_language);
380     } else {
381       const char *sum_cstr =
382           m_valobj->GetSummaryAsCString(m_options.m_varformat_language);
383       if (sum_cstr)
384         summary.assign(sum_cstr);
385     }
386   }
387 }
388 
PrintValueAndSummaryIfNeeded(bool & value_printed,bool & summary_printed)389 bool ValueObjectPrinter::PrintValueAndSummaryIfNeeded(bool &value_printed,
390                                                       bool &summary_printed) {
391   bool error_printed = false;
392   if (ShouldPrintValueObject()) {
393     if (!CheckScopeIfNeeded())
394       m_error.assign("out of scope");
395     if (m_error.empty()) {
396       GetValueSummaryError(m_value, m_summary, m_error);
397     }
398     if (m_error.size()) {
399       // we need to support scenarios in which it is actually fine for a value
400       // to have no type but - on the other hand - if we get an error *AND*
401       // have no type, we try to get out gracefully, since most often that
402       // combination means "could not resolve a type" and the default failure
403       // mode is quite ugly
404       if (!m_compiler_type.IsValid()) {
405         m_stream->Printf(" <could not resolve type>");
406         return false;
407       }
408 
409       error_printed = true;
410       m_stream->Printf(" <%s>\n", m_error.c_str());
411     } else {
412       // Make sure we have a value and make sure the summary didn't specify
413       // that the value should not be printed - and do not print the value if
414       // this thing is nil (but show the value if the user passes a format
415       // explicitly)
416       TypeSummaryImpl *entry = GetSummaryFormatter();
417       const bool has_nil_or_uninitialized_summary =
418           (IsNil() || IsUninitialized()) && !m_summary.empty();
419       if (!has_nil_or_uninitialized_summary && !m_value.empty() &&
420           (entry == nullptr ||
421            (entry->DoesPrintValue(m_valobj) ||
422             m_options.m_format != eFormatDefault) ||
423            m_summary.empty()) &&
424           !m_options.m_hide_value) {
425         if (m_options.m_hide_pointer_value &&
426             IsPointerValue(m_valobj->GetCompilerType())) {
427         } else {
428           m_stream->Printf(" %s", m_value.c_str());
429           value_printed = true;
430         }
431       }
432 
433       if (m_summary.size()) {
434         m_stream->Printf(" %s", m_summary.c_str());
435         summary_printed = true;
436       }
437     }
438   }
439   return !error_printed;
440 }
441 
PrintObjectDescriptionIfNeeded(bool value_printed,bool summary_printed)442 bool ValueObjectPrinter::PrintObjectDescriptionIfNeeded(bool value_printed,
443                                                         bool summary_printed) {
444   if (ShouldPrintValueObject()) {
445     // let's avoid the overly verbose no description error for a nil thing
446     if (m_options.m_use_objc && !IsNil() && !IsUninitialized() &&
447         (!m_options.m_pointer_as_array)) {
448       if (!m_options.m_hide_value || !m_options.m_hide_name)
449         m_stream->Printf(" ");
450       const char *object_desc = nullptr;
451       if (value_printed || summary_printed)
452         object_desc = m_valobj->GetObjectDescription();
453       else
454         object_desc = GetDescriptionForDisplay();
455       if (object_desc && *object_desc) {
456         // If the description already ends with a \n don't add another one.
457         size_t object_end = strlen(object_desc) - 1;
458         if (object_desc[object_end] == '\n')
459           m_stream->Printf("%s", object_desc);
460         else
461           m_stream->Printf("%s\n", object_desc);
462         return true;
463       } else if (!value_printed && !summary_printed)
464         return true;
465       else
466         return false;
467     }
468   }
469   return true;
470 }
471 
CanAllowExpansion() const472 bool DumpValueObjectOptions::PointerDepth::CanAllowExpansion() const {
473   switch (m_mode) {
474   case Mode::Always:
475   case Mode::Default:
476     return m_count > 0;
477   case Mode::Never:
478     return false;
479   }
480   return false;
481 }
482 
ShouldPrintChildren(bool is_failed_description,DumpValueObjectOptions::PointerDepth & curr_ptr_depth)483 bool ValueObjectPrinter::ShouldPrintChildren(
484     bool is_failed_description,
485     DumpValueObjectOptions::PointerDepth &curr_ptr_depth) {
486   const bool is_ref = IsRef();
487   const bool is_ptr = IsPtr();
488   const bool is_uninit = IsUninitialized();
489 
490   if (is_uninit)
491     return false;
492 
493   // if the user has specified an element count, always print children as it is
494   // explicit user demand being honored
495   if (m_options.m_pointer_as_array)
496     return true;
497 
498   TypeSummaryImpl *entry = GetSummaryFormatter();
499 
500   if (m_options.m_use_objc)
501     return false;
502 
503   if (is_failed_description || !HasReachedMaximumDepth()) {
504     // We will show children for all concrete types. We won't show pointer
505     // contents unless a pointer depth has been specified. We won't reference
506     // contents unless the reference is the root object (depth of zero).
507 
508     // Use a new temporary pointer depth in case we override the current
509     // pointer depth below...
510 
511     if (is_ptr || is_ref) {
512       // We have a pointer or reference whose value is an address. Make sure
513       // that address is not NULL
514       AddressType ptr_address_type;
515       if (m_valobj->GetPointerValue(&ptr_address_type) == 0)
516         return false;
517 
518       const bool is_root_level = m_curr_depth == 0;
519 
520       if (is_ref && is_root_level) {
521         // If this is the root object (depth is zero) that we are showing and
522         // it is a reference, and no pointer depth has been supplied print out
523         // what it references. Don't do this at deeper depths otherwise we can
524         // end up with infinite recursion...
525         return true;
526       }
527 
528       return curr_ptr_depth.CanAllowExpansion();
529     }
530 
531     return (!entry || entry->DoesPrintChildren(m_valobj) || m_summary.empty());
532   }
533   return false;
534 }
535 
ShouldExpandEmptyAggregates()536 bool ValueObjectPrinter::ShouldExpandEmptyAggregates() {
537   TypeSummaryImpl *entry = GetSummaryFormatter();
538 
539   if (!entry)
540     return true;
541 
542   return entry->DoesPrintEmptyAggregates();
543 }
544 
GetValueObjectForChildrenGeneration()545 ValueObject *ValueObjectPrinter::GetValueObjectForChildrenGeneration() {
546   return m_valobj;
547 }
548 
PrintChildrenPreamble()549 void ValueObjectPrinter::PrintChildrenPreamble() {
550   if (m_options.m_flat_output) {
551     if (ShouldPrintValueObject())
552       m_stream->EOL();
553   } else {
554     if (ShouldPrintValueObject())
555       m_stream->PutCString(IsRef() ? ": {\n" : " {\n");
556     m_stream->IndentMore();
557   }
558 }
559 
PrintChild(ValueObjectSP child_sp,const DumpValueObjectOptions::PointerDepth & curr_ptr_depth)560 void ValueObjectPrinter::PrintChild(
561     ValueObjectSP child_sp,
562     const DumpValueObjectOptions::PointerDepth &curr_ptr_depth) {
563   const uint32_t consumed_depth = (!m_options.m_pointer_as_array) ? 1 : 0;
564   const bool does_consume_ptr_depth =
565       ((IsPtr() && !m_options.m_pointer_as_array) || IsRef());
566 
567   DumpValueObjectOptions child_options(m_options);
568   child_options.SetFormat(m_options.m_format)
569       .SetSummary()
570       .SetRootValueObjectName();
571   child_options.SetScopeChecked(true)
572       .SetHideName(m_options.m_hide_name)
573       .SetHideValue(m_options.m_hide_value)
574       .SetOmitSummaryDepth(child_options.m_omit_summary_depth > 1
575                                ? child_options.m_omit_summary_depth -
576                                      consumed_depth
577                                : 0)
578       .SetElementCount(0);
579 
580   if (child_sp.get()) {
581     ValueObjectPrinter child_printer(
582         child_sp.get(), m_stream, child_options,
583         does_consume_ptr_depth ? --curr_ptr_depth : curr_ptr_depth,
584         m_curr_depth + consumed_depth, m_printed_instance_pointers);
585     child_printer.PrintValueObject();
586   }
587 }
588 
GetMaxNumChildrenToPrint(bool & print_dotdotdot)589 uint32_t ValueObjectPrinter::GetMaxNumChildrenToPrint(bool &print_dotdotdot) {
590   ValueObject *synth_m_valobj = GetValueObjectForChildrenGeneration();
591 
592   if (m_options.m_pointer_as_array)
593     return m_options.m_pointer_as_array.m_element_count;
594 
595   size_t num_children = synth_m_valobj->GetNumChildren();
596   print_dotdotdot = false;
597   if (num_children) {
598     const size_t max_num_children =
599         m_valobj->GetTargetSP()->GetMaximumNumberOfChildrenToDisplay();
600 
601     if (num_children > max_num_children && !m_options.m_ignore_cap) {
602       print_dotdotdot = true;
603       return max_num_children;
604     }
605   }
606   return num_children;
607 }
608 
PrintChildrenPostamble(bool print_dotdotdot)609 void ValueObjectPrinter::PrintChildrenPostamble(bool print_dotdotdot) {
610   if (!m_options.m_flat_output) {
611     if (print_dotdotdot) {
612       m_valobj->GetTargetSP()
613           ->GetDebugger()
614           .GetCommandInterpreter()
615           .ChildrenTruncated();
616       m_stream->Indent("...\n");
617     }
618     m_stream->IndentLess();
619     m_stream->Indent("}\n");
620   }
621 }
622 
ShouldPrintEmptyBrackets(bool value_printed,bool summary_printed)623 bool ValueObjectPrinter::ShouldPrintEmptyBrackets(bool value_printed,
624                                                   bool summary_printed) {
625   ValueObject *synth_m_valobj = GetValueObjectForChildrenGeneration();
626 
627   if (!IsAggregate())
628     return false;
629 
630   if (!m_options.m_reveal_empty_aggregates) {
631     if (value_printed || summary_printed)
632       return false;
633   }
634 
635   if (synth_m_valobj->MightHaveChildren())
636     return true;
637 
638   if (m_val_summary_ok)
639     return false;
640 
641   return true;
642 }
643 
PhysicalIndexForLogicalIndex(size_t base,size_t stride,size_t logical)644 static constexpr size_t PhysicalIndexForLogicalIndex(size_t base, size_t stride,
645                                                      size_t logical) {
646   return base + logical * stride;
647 }
648 
GenerateChild(ValueObject * synth_valobj,size_t idx)649 ValueObjectSP ValueObjectPrinter::GenerateChild(ValueObject *synth_valobj,
650                                                 size_t idx) {
651   if (m_options.m_pointer_as_array) {
652     // if generating pointer-as-array children, use GetSyntheticArrayMember
653     return synth_valobj->GetSyntheticArrayMember(
654         PhysicalIndexForLogicalIndex(
655             m_options.m_pointer_as_array.m_base_element,
656             m_options.m_pointer_as_array.m_stride, idx),
657         true);
658   } else {
659     // otherwise, do the usual thing
660     return synth_valobj->GetChildAtIndex(idx, true);
661   }
662 }
663 
PrintChildren(bool value_printed,bool summary_printed,const DumpValueObjectOptions::PointerDepth & curr_ptr_depth)664 void ValueObjectPrinter::PrintChildren(
665     bool value_printed, bool summary_printed,
666     const DumpValueObjectOptions::PointerDepth &curr_ptr_depth) {
667   ValueObject *synth_m_valobj = GetValueObjectForChildrenGeneration();
668 
669   bool print_dotdotdot = false;
670   size_t num_children = GetMaxNumChildrenToPrint(print_dotdotdot);
671   if (num_children) {
672     bool any_children_printed = false;
673 
674     for (size_t idx = 0; idx < num_children; ++idx) {
675       if (ValueObjectSP child_sp = GenerateChild(synth_m_valobj, idx)) {
676         if (!any_children_printed) {
677           PrintChildrenPreamble();
678           any_children_printed = true;
679         }
680         PrintChild(child_sp, curr_ptr_depth);
681       }
682     }
683 
684     if (any_children_printed)
685       PrintChildrenPostamble(print_dotdotdot);
686     else {
687       if (ShouldPrintEmptyBrackets(value_printed, summary_printed)) {
688         if (ShouldPrintValueObject())
689           m_stream->PutCString(" {}\n");
690         else
691           m_stream->EOL();
692       } else
693         m_stream->EOL();
694     }
695   } else if (ShouldPrintEmptyBrackets(value_printed, summary_printed)) {
696     // Aggregate, no children...
697     if (ShouldPrintValueObject()) {
698       // if it has a synthetic value, then don't print {}, the synthetic
699       // children are probably only being used to vend a value
700       if (m_valobj->DoesProvideSyntheticValue() ||
701           !ShouldExpandEmptyAggregates())
702         m_stream->PutCString("\n");
703       else
704         m_stream->PutCString(" {}\n");
705     }
706   } else {
707     if (ShouldPrintValueObject())
708       m_stream->EOL();
709   }
710 }
711 
PrintChildrenOneLiner(bool hide_names)712 bool ValueObjectPrinter::PrintChildrenOneLiner(bool hide_names) {
713   if (!GetMostSpecializedValue() || m_valobj == nullptr)
714     return false;
715 
716   ValueObject *synth_m_valobj = GetValueObjectForChildrenGeneration();
717 
718   bool print_dotdotdot = false;
719   size_t num_children = GetMaxNumChildrenToPrint(print_dotdotdot);
720 
721   if (num_children) {
722     m_stream->PutChar('(');
723 
724     for (uint32_t idx = 0; idx < num_children; ++idx) {
725       lldb::ValueObjectSP child_sp(synth_m_valobj->GetChildAtIndex(idx, true));
726       if (child_sp)
727         child_sp = child_sp->GetQualifiedRepresentationIfAvailable(
728             m_options.m_use_dynamic, m_options.m_use_synthetic);
729       if (child_sp) {
730         if (idx)
731           m_stream->PutCString(", ");
732         if (!hide_names) {
733           const char *name = child_sp.get()->GetName().AsCString();
734           if (name && *name) {
735             m_stream->PutCString(name);
736             m_stream->PutCString(" = ");
737           }
738         }
739         child_sp->DumpPrintableRepresentation(
740             *m_stream, ValueObject::eValueObjectRepresentationStyleSummary,
741             m_options.m_format,
742             ValueObject::PrintableRepresentationSpecialCases::eDisable);
743       }
744     }
745 
746     if (print_dotdotdot)
747       m_stream->PutCString(", ...)");
748     else
749       m_stream->PutChar(')');
750   }
751   return true;
752 }
753 
PrintChildrenIfNeeded(bool value_printed,bool summary_printed)754 void ValueObjectPrinter::PrintChildrenIfNeeded(bool value_printed,
755                                                bool summary_printed) {
756   // This flag controls whether we tried to display a description for this
757   // object and failed if that happens, we want to display the children if any.
758   bool is_failed_description =
759       !PrintObjectDescriptionIfNeeded(value_printed, summary_printed);
760 
761   DumpValueObjectOptions::PointerDepth curr_ptr_depth = m_ptr_depth;
762   const bool print_children =
763       ShouldPrintChildren(is_failed_description, curr_ptr_depth);
764   const bool print_oneline =
765       (curr_ptr_depth.CanAllowExpansion() || m_options.m_show_types ||
766        !m_options.m_allow_oneliner_mode || m_options.m_flat_output ||
767        (m_options.m_pointer_as_array) || m_options.m_show_location)
768           ? false
769           : DataVisualization::ShouldPrintAsOneLiner(*m_valobj);
770   if (print_children && IsInstancePointer()) {
771     uint64_t instance_ptr_value = m_valobj->GetValueAsUnsigned(0);
772     if (m_printed_instance_pointers->count(instance_ptr_value)) {
773       // We already printed this instance-is-pointer thing, so don't expand it.
774       m_stream->PutCString(" {...}\n");
775       return;
776     } else {
777       // Remember this guy for future reference.
778       m_printed_instance_pointers->emplace(instance_ptr_value);
779     }
780   }
781 
782   if (print_children) {
783     if (print_oneline) {
784       m_stream->PutChar(' ');
785       PrintChildrenOneLiner(false);
786       m_stream->EOL();
787     } else
788       PrintChildren(value_printed, summary_printed, curr_ptr_depth);
789   } else if (HasReachedMaximumDepth() && IsAggregate() &&
790              ShouldPrintValueObject()) {
791     m_stream->PutCString("{...}\n");
792     // The maximum child depth has been reached. If `m_max_depth` is the default
793     // (i.e. the user has _not_ customized it), then lldb presents a warning to
794     // the user. The warning tells the user that the limit has been reached, but
795     // more importantly tells them how to expand the limit if desired.
796     if (m_options.m_max_depth_is_default)
797       m_valobj->GetTargetSP()
798           ->GetDebugger()
799           .GetCommandInterpreter()
800           .SetReachedMaximumDepth();
801   } else
802     m_stream->EOL();
803 }
804 
HasReachedMaximumDepth()805 bool ValueObjectPrinter::HasReachedMaximumDepth() {
806   return m_curr_depth >= m_options.m_max_depth;
807 }
808