1 //===-- LibCxx.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 "LibCxx.h"
10 
11 #include "lldb/Core/Debugger.h"
12 #include "lldb/Core/FormatEntity.h"
13 #include "lldb/Core/ValueObject.h"
14 #include "lldb/Core/ValueObjectConstResult.h"
15 #include "lldb/DataFormatters/FormattersHelpers.h"
16 #include "lldb/DataFormatters/StringPrinter.h"
17 #include "lldb/DataFormatters/TypeSummary.h"
18 #include "lldb/DataFormatters/VectorIterator.h"
19 #include "lldb/Target/ProcessStructReader.h"
20 #include "lldb/Target/SectionLoadList.h"
21 #include "lldb/Target/Target.h"
22 #include "lldb/Utility/ConstString.h"
23 #include "lldb/Utility/DataBufferHeap.h"
24 #include "lldb/Utility/Endian.h"
25 #include "lldb/Utility/Status.h"
26 #include "lldb/Utility/Stream.h"
27 
28 #include "Plugins/LanguageRuntime/CPlusPlus/CPPLanguageRuntime.h"
29 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
30 #include "lldb/lldb-enumerations.h"
31 #include <tuple>
32 
33 using namespace lldb;
34 using namespace lldb_private;
35 using namespace lldb_private::formatters;
36 
LibcxxOptionalSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & options)37 bool lldb_private::formatters::LibcxxOptionalSummaryProvider(
38     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
39   ValueObjectSP valobj_sp(valobj.GetNonSyntheticValue());
40   if (!valobj_sp)
41     return false;
42 
43   // An optional either contains a value or not, the member __engaged_ is
44   // a bool flag, it is true if the optional has a value and false otherwise.
45   ValueObjectSP engaged_sp(
46       valobj_sp->GetChildMemberWithName(ConstString("__engaged_"), true));
47 
48   if (!engaged_sp)
49     return false;
50 
51   llvm::StringRef engaged_as_cstring(
52       engaged_sp->GetValueAsUnsigned(0) == 1 ? "true" : "false");
53 
54   stream.Printf(" Has Value=%s ", engaged_as_cstring.data());
55 
56   return true;
57 }
58 
LibcxxFunctionSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & options)59 bool lldb_private::formatters::LibcxxFunctionSummaryProvider(
60     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
61 
62   ValueObjectSP valobj_sp(valobj.GetNonSyntheticValue());
63 
64   if (!valobj_sp)
65     return false;
66 
67   ExecutionContext exe_ctx(valobj_sp->GetExecutionContextRef());
68   Process *process = exe_ctx.GetProcessPtr();
69 
70   if (process == nullptr)
71     return false;
72 
73   CPPLanguageRuntime *cpp_runtime = CPPLanguageRuntime::Get(*process);
74 
75   if (!cpp_runtime)
76     return false;
77 
78   CPPLanguageRuntime::LibCppStdFunctionCallableInfo callable_info =
79       cpp_runtime->FindLibCppStdFunctionCallableInfo(valobj_sp);
80 
81   switch (callable_info.callable_case) {
82   case CPPLanguageRuntime::LibCppStdFunctionCallableCase::Invalid:
83     stream.Printf(" __f_ = %" PRIu64, callable_info.member_f_pointer_value);
84     return false;
85     break;
86   case CPPLanguageRuntime::LibCppStdFunctionCallableCase::Lambda:
87     stream.Printf(
88         " Lambda in File %s at Line %u",
89         callable_info.callable_line_entry.file.GetFilename().GetCString(),
90         callable_info.callable_line_entry.line);
91     break;
92   case CPPLanguageRuntime::LibCppStdFunctionCallableCase::CallableObject:
93     stream.Printf(
94         " Function in File %s at Line %u",
95         callable_info.callable_line_entry.file.GetFilename().GetCString(),
96         callable_info.callable_line_entry.line);
97     break;
98   case CPPLanguageRuntime::LibCppStdFunctionCallableCase::FreeOrMemberFunction:
99     stream.Printf(" Function = %s ",
100                   callable_info.callable_symbol.GetName().GetCString());
101     break;
102   }
103 
104   return true;
105 }
106 
LibcxxSmartPointerSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & options)107 bool lldb_private::formatters::LibcxxSmartPointerSummaryProvider(
108     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
109   ValueObjectSP valobj_sp(valobj.GetNonSyntheticValue());
110   if (!valobj_sp)
111     return false;
112   ValueObjectSP ptr_sp(
113       valobj_sp->GetChildMemberWithName(ConstString("__ptr_"), true));
114   ValueObjectSP count_sp(valobj_sp->GetChildAtNamePath(
115       {ConstString("__cntrl_"), ConstString("__shared_owners_")}));
116   ValueObjectSP weakcount_sp(valobj_sp->GetChildAtNamePath(
117       {ConstString("__cntrl_"), ConstString("__shared_weak_owners_")}));
118 
119   if (!ptr_sp)
120     return false;
121 
122   if (ptr_sp->GetValueAsUnsigned(0) == 0) {
123     stream.Printf("nullptr");
124     return true;
125   } else {
126     bool print_pointee = false;
127     Status error;
128     ValueObjectSP pointee_sp = ptr_sp->Dereference(error);
129     if (pointee_sp && error.Success()) {
130       if (pointee_sp->DumpPrintableRepresentation(
131               stream, ValueObject::eValueObjectRepresentationStyleSummary,
132               lldb::eFormatInvalid,
133               ValueObject::PrintableRepresentationSpecialCases::eDisable,
134               false))
135         print_pointee = true;
136     }
137     if (!print_pointee)
138       stream.Printf("ptr = 0x%" PRIx64, ptr_sp->GetValueAsUnsigned(0));
139   }
140 
141   if (count_sp)
142     stream.Printf(" strong=%" PRIu64, 1 + count_sp->GetValueAsUnsigned(0));
143 
144   if (weakcount_sp)
145     stream.Printf(" weak=%" PRIu64, 1 + weakcount_sp->GetValueAsUnsigned(0));
146 
147   return true;
148 }
149 
LibcxxUniquePointerSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & options)150 bool lldb_private::formatters::LibcxxUniquePointerSummaryProvider(
151     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
152   ValueObjectSP valobj_sp(valobj.GetNonSyntheticValue());
153   if (!valobj_sp)
154     return false;
155 
156   ValueObjectSP ptr_sp(
157       valobj_sp->GetChildMemberWithName(ConstString("__ptr_"), true));
158   if (!ptr_sp)
159     return false;
160 
161   ptr_sp = GetValueOfLibCXXCompressedPair(*ptr_sp);
162   if (!ptr_sp)
163     return false;
164 
165   if (ptr_sp->GetValueAsUnsigned(0) == 0) {
166     stream.Printf("nullptr");
167     return true;
168   } else {
169     bool print_pointee = false;
170     Status error;
171     ValueObjectSP pointee_sp = ptr_sp->Dereference(error);
172     if (pointee_sp && error.Success()) {
173       if (pointee_sp->DumpPrintableRepresentation(
174               stream, ValueObject::eValueObjectRepresentationStyleSummary,
175               lldb::eFormatInvalid,
176               ValueObject::PrintableRepresentationSpecialCases::eDisable,
177               false))
178         print_pointee = true;
179     }
180     if (!print_pointee)
181       stream.Printf("ptr = 0x%" PRIx64, ptr_sp->GetValueAsUnsigned(0));
182   }
183 
184   return true;
185 }
186 
187 /*
188  (lldb) fr var ibeg --raw --ptr-depth 1
189  (std::__1::__map_iterator<std::__1::__tree_iterator<std::__1::pair<int,
190  std::__1::basic_string<char, std::__1::char_traits<char>,
191  std::__1::allocator<char> > >, std::__1::__tree_node<std::__1::pair<int,
192  std::__1::basic_string<char, std::__1::char_traits<char>,
193  std::__1::allocator<char> > >, void *> *, long> >) ibeg = {
194  __i_ = {
195  __ptr_ = 0x0000000100103870 {
196  std::__1::__tree_node_base<void *> = {
197  std::__1::__tree_end_node<std::__1::__tree_node_base<void *> *> = {
198  __left_ = 0x0000000000000000
199  }
200  __right_ = 0x0000000000000000
201  __parent_ = 0x00000001001038b0
202  __is_black_ = true
203  }
204  __value_ = {
205  first = 0
206  second = { std::string }
207  */
208 
209 lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::
LibCxxMapIteratorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)210     LibCxxMapIteratorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
211     : SyntheticChildrenFrontEnd(*valobj_sp), m_pair_ptr(), m_pair_sp() {
212   if (valobj_sp)
213     Update();
214 }
215 
Update()216 bool lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::Update() {
217   m_pair_sp.reset();
218   m_pair_ptr = nullptr;
219 
220   ValueObjectSP valobj_sp = m_backend.GetSP();
221   if (!valobj_sp)
222     return false;
223 
224   TargetSP target_sp(valobj_sp->GetTargetSP());
225 
226   if (!target_sp)
227     return false;
228 
229   if (!valobj_sp)
230     return false;
231 
232   static ConstString g_i_("__i_");
233 
234   // this must be a ValueObject* because it is a child of the ValueObject we
235   // are producing children for it if were a ValueObjectSP, we would end up
236   // with a loop (iterator -> synthetic -> child -> parent == iterator) and
237   // that would in turn leak memory by never allowing the ValueObjects to die
238   // and free their memory
239   m_pair_ptr = valobj_sp
240                    ->GetValueForExpressionPath(
241                        ".__i_.__ptr_->__value_", nullptr, nullptr,
242                        ValueObject::GetValueForExpressionPathOptions()
243                            .DontCheckDotVsArrowSyntax()
244                            .SetSyntheticChildrenTraversal(
245                                ValueObject::GetValueForExpressionPathOptions::
246                                    SyntheticChildrenTraversal::None),
247                        nullptr)
248                    .get();
249 
250   if (!m_pair_ptr) {
251     m_pair_ptr = valobj_sp
252                      ->GetValueForExpressionPath(
253                          ".__i_.__ptr_", nullptr, nullptr,
254                          ValueObject::GetValueForExpressionPathOptions()
255                              .DontCheckDotVsArrowSyntax()
256                              .SetSyntheticChildrenTraversal(
257                                  ValueObject::GetValueForExpressionPathOptions::
258                                      SyntheticChildrenTraversal::None),
259                          nullptr)
260                      .get();
261     if (m_pair_ptr) {
262       auto __i_(valobj_sp->GetChildMemberWithName(g_i_, true));
263       if (!__i_) {
264         m_pair_ptr = nullptr;
265         return false;
266       }
267       CompilerType pair_type(
268           __i_->GetCompilerType().GetTypeTemplateArgument(0));
269       std::string name;
270       uint64_t bit_offset_ptr;
271       uint32_t bitfield_bit_size_ptr;
272       bool is_bitfield_ptr;
273       pair_type = pair_type.GetFieldAtIndex(
274           0, name, &bit_offset_ptr, &bitfield_bit_size_ptr, &is_bitfield_ptr);
275       if (!pair_type) {
276         m_pair_ptr = nullptr;
277         return false;
278       }
279 
280       auto addr(m_pair_ptr->GetValueAsUnsigned(LLDB_INVALID_ADDRESS));
281       m_pair_ptr = nullptr;
282       if (addr && addr != LLDB_INVALID_ADDRESS) {
283         TypeSystemClang *ast_ctx =
284             llvm::dyn_cast_or_null<TypeSystemClang>(pair_type.GetTypeSystem());
285         if (!ast_ctx)
286           return false;
287 
288         // Mimick layout of std::__tree_iterator::__ptr_ and read it in
289         // from process memory.
290         //
291         // The following shows the contiguous block of memory:
292         //
293         //        +-----------------------------+ class __tree_end_node
294         // __ptr_ | pointer __left_;            |
295         //        +-----------------------------+ class __tree_node_base
296         //        | pointer __right_;           |
297         //        | __parent_pointer __parent_; |
298         //        | bool __is_black_;           |
299         //        +-----------------------------+ class __tree_node
300         //        | __node_value_type __value_; | <<< our key/value pair
301         //        +-----------------------------+
302         //
303         CompilerType tree_node_type = ast_ctx->CreateStructForIdentifier(
304             ConstString(),
305             {{"ptr0",
306               ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
307              {"ptr1",
308               ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
309              {"ptr2",
310               ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
311              {"cw", ast_ctx->GetBasicType(lldb::eBasicTypeBool)},
312              {"payload", pair_type}});
313         llvm::Optional<uint64_t> size = tree_node_type.GetByteSize(nullptr);
314         if (!size)
315           return false;
316         WritableDataBufferSP buffer_sp(new DataBufferHeap(*size, 0));
317         ProcessSP process_sp(target_sp->GetProcessSP());
318         Status error;
319         process_sp->ReadMemory(addr, buffer_sp->GetBytes(),
320                                buffer_sp->GetByteSize(), error);
321         if (error.Fail())
322           return false;
323         DataExtractor extractor(buffer_sp, process_sp->GetByteOrder(),
324                                 process_sp->GetAddressByteSize());
325         auto pair_sp = CreateValueObjectFromData(
326             "pair", extractor, valobj_sp->GetExecutionContextRef(),
327             tree_node_type);
328         if (pair_sp)
329           m_pair_sp = pair_sp->GetChildAtIndex(4, true);
330       }
331     }
332   }
333 
334   return false;
335 }
336 
337 size_t lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::
CalculateNumChildren()338     CalculateNumChildren() {
339   return 2;
340 }
341 
342 lldb::ValueObjectSP
GetChildAtIndex(size_t idx)343 lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::GetChildAtIndex(
344     size_t idx) {
345   if (m_pair_ptr)
346     return m_pair_ptr->GetChildAtIndex(idx, true);
347   if (m_pair_sp)
348     return m_pair_sp->GetChildAtIndex(idx, true);
349   return lldb::ValueObjectSP();
350 }
351 
352 bool lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::
MightHaveChildren()353     MightHaveChildren() {
354   return true;
355 }
356 
357 size_t lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::
GetIndexOfChildWithName(ConstString name)358     GetIndexOfChildWithName(ConstString name) {
359   if (name == "first")
360     return 0;
361   if (name == "second")
362     return 1;
363   return UINT32_MAX;
364 }
365 
366 lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::
~LibCxxMapIteratorSyntheticFrontEnd()367     ~LibCxxMapIteratorSyntheticFrontEnd() {
368   // this will be deleted when its parent dies (since it's a child object)
369   // delete m_pair_ptr;
370 }
371 
372 SyntheticChildrenFrontEnd *
LibCxxMapIteratorSyntheticFrontEndCreator(CXXSyntheticChildren *,lldb::ValueObjectSP valobj_sp)373 lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEndCreator(
374     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
375   return (valobj_sp ? new LibCxxMapIteratorSyntheticFrontEnd(valobj_sp)
376                     : nullptr);
377 }
378 
379 lldb_private::formatters::LibCxxUnorderedMapIteratorSyntheticFrontEnd::
LibCxxUnorderedMapIteratorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)380     LibCxxUnorderedMapIteratorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
381     : SyntheticChildrenFrontEnd(*valobj_sp) {
382   if (valobj_sp)
383     Update();
384 }
385 
386 bool lldb_private::formatters::LibCxxUnorderedMapIteratorSyntheticFrontEnd::
Update()387     Update() {
388   m_pair_sp.reset();
389   m_iter_ptr = nullptr;
390 
391   ValueObjectSP valobj_sp = m_backend.GetSP();
392   if (!valobj_sp)
393     return false;
394 
395   TargetSP target_sp(valobj_sp->GetTargetSP());
396 
397   if (!target_sp)
398     return false;
399 
400   if (!valobj_sp)
401     return false;
402 
403   auto exprPathOptions = ValueObject::GetValueForExpressionPathOptions()
404                              .DontCheckDotVsArrowSyntax()
405                              .SetSyntheticChildrenTraversal(
406                                  ValueObject::GetValueForExpressionPathOptions::
407                                      SyntheticChildrenTraversal::None);
408 
409   // This must be a ValueObject* because it is a child of the ValueObject we
410   // are producing children for it if were a ValueObjectSP, we would end up
411   // with a loop (iterator -> synthetic -> child -> parent == iterator) and
412   // that would in turn leak memory by never allowing the ValueObjects to die
413   // and free their memory.
414   m_iter_ptr =
415       valobj_sp
416           ->GetValueForExpressionPath(".__i_.__node_", nullptr, nullptr,
417                                       exprPathOptions, nullptr)
418           .get();
419 
420   if (m_iter_ptr) {
421     auto iter_child(
422         valobj_sp->GetChildMemberWithName(ConstString("__i_"), true));
423     if (!iter_child) {
424       m_iter_ptr = nullptr;
425       return false;
426     }
427 
428     CompilerType node_type(iter_child->GetCompilerType()
429                                .GetTypeTemplateArgument(0)
430                                .GetPointeeType());
431 
432     CompilerType pair_type(node_type.GetTypeTemplateArgument(0));
433 
434     std::string name;
435     uint64_t bit_offset_ptr;
436     uint32_t bitfield_bit_size_ptr;
437     bool is_bitfield_ptr;
438 
439     pair_type = pair_type.GetFieldAtIndex(
440         0, name, &bit_offset_ptr, &bitfield_bit_size_ptr, &is_bitfield_ptr);
441     if (!pair_type) {
442       m_iter_ptr = nullptr;
443       return false;
444     }
445 
446     uint64_t addr = m_iter_ptr->GetValueAsUnsigned(LLDB_INVALID_ADDRESS);
447     m_iter_ptr = nullptr;
448 
449     if (addr == 0 || addr == LLDB_INVALID_ADDRESS)
450       return false;
451 
452     TypeSystemClang *ast_ctx =
453         llvm::dyn_cast_or_null<TypeSystemClang>(pair_type.GetTypeSystem());
454     if (!ast_ctx)
455       return false;
456 
457     // Mimick layout of std::__hash_iterator::__node_ and read it in
458     // from process memory.
459     //
460     // The following shows the contiguous block of memory:
461     //
462     //         +-----------------------------+ class __hash_node_base
463     // __node_ | __next_pointer __next_;     |
464     //         +-----------------------------+ class __hash_node
465     //         | size_t __hash_;             |
466     //         | __node_value_type __value_; | <<< our key/value pair
467     //         +-----------------------------+
468     //
469     CompilerType tree_node_type = ast_ctx->CreateStructForIdentifier(
470         ConstString(),
471         {{"__next_",
472           ast_ctx->GetBasicType(lldb::eBasicTypeVoid).GetPointerType()},
473          {"__hash_", ast_ctx->GetBasicType(lldb::eBasicTypeUnsignedLongLong)},
474          {"__value_", pair_type}});
475     llvm::Optional<uint64_t> size = tree_node_type.GetByteSize(nullptr);
476     if (!size)
477       return false;
478     WritableDataBufferSP buffer_sp(new DataBufferHeap(*size, 0));
479     ProcessSP process_sp(target_sp->GetProcessSP());
480     Status error;
481     process_sp->ReadMemory(addr, buffer_sp->GetBytes(),
482                            buffer_sp->GetByteSize(), error);
483     if (error.Fail())
484       return false;
485     DataExtractor extractor(buffer_sp, process_sp->GetByteOrder(),
486                             process_sp->GetAddressByteSize());
487     auto pair_sp = CreateValueObjectFromData(
488         "pair", extractor, valobj_sp->GetExecutionContextRef(), tree_node_type);
489     if (pair_sp)
490       m_pair_sp = pair_sp->GetChildAtIndex(2, true);
491   }
492 
493   return false;
494 }
495 
496 size_t lldb_private::formatters::LibCxxUnorderedMapIteratorSyntheticFrontEnd::
CalculateNumChildren()497     CalculateNumChildren() {
498   return 2;
499 }
500 
501 lldb::ValueObjectSP lldb_private::formatters::
GetChildAtIndex(size_t idx)502     LibCxxUnorderedMapIteratorSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
503   if (m_pair_sp)
504     return m_pair_sp->GetChildAtIndex(idx, true);
505   return lldb::ValueObjectSP();
506 }
507 
508 bool lldb_private::formatters::LibCxxUnorderedMapIteratorSyntheticFrontEnd::
MightHaveChildren()509     MightHaveChildren() {
510   return true;
511 }
512 
513 size_t lldb_private::formatters::LibCxxUnorderedMapIteratorSyntheticFrontEnd::
GetIndexOfChildWithName(ConstString name)514     GetIndexOfChildWithName(ConstString name) {
515   if (name == "first")
516     return 0;
517   if (name == "second")
518     return 1;
519   return UINT32_MAX;
520 }
521 
522 SyntheticChildrenFrontEnd *
LibCxxUnorderedMapIteratorSyntheticFrontEndCreator(CXXSyntheticChildren *,lldb::ValueObjectSP valobj_sp)523 lldb_private::formatters::LibCxxUnorderedMapIteratorSyntheticFrontEndCreator(
524     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
525   return (valobj_sp ? new LibCxxUnorderedMapIteratorSyntheticFrontEnd(valobj_sp)
526                     : nullptr);
527 }
528 
529 /*
530  (lldb) fr var ibeg --raw --ptr-depth 1 -T
531  (std::__1::__wrap_iter<int *>) ibeg = {
532  (std::__1::__wrap_iter<int *>::iterator_type) __i = 0x00000001001037a0 {
533  (int) *__i = 1
534  }
535  }
536 */
537 
538 SyntheticChildrenFrontEnd *
LibCxxVectorIteratorSyntheticFrontEndCreator(CXXSyntheticChildren *,lldb::ValueObjectSP valobj_sp)539 lldb_private::formatters::LibCxxVectorIteratorSyntheticFrontEndCreator(
540     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
541   static ConstString g_item_name;
542   if (!g_item_name)
543     g_item_name.SetCString("__i");
544   return (valobj_sp
545               ? new VectorIteratorSyntheticFrontEnd(valobj_sp, g_item_name)
546               : nullptr);
547 }
548 
549 lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd::
LibcxxSharedPtrSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)550     LibcxxSharedPtrSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
551     : SyntheticChildrenFrontEnd(*valobj_sp), m_cntrl(nullptr) {
552   if (valobj_sp)
553     Update();
554 }
555 
556 size_t lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd::
CalculateNumChildren()557     CalculateNumChildren() {
558   return (m_cntrl ? 1 : 0);
559 }
560 
561 lldb::ValueObjectSP
GetChildAtIndex(size_t idx)562 lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd::GetChildAtIndex(
563     size_t idx) {
564   if (!m_cntrl)
565     return lldb::ValueObjectSP();
566 
567   ValueObjectSP valobj_sp = m_backend.GetSP();
568   if (!valobj_sp)
569     return lldb::ValueObjectSP();
570 
571   if (idx == 0)
572     return valobj_sp->GetChildMemberWithName(ConstString("__ptr_"), true);
573 
574   if (idx == 1) {
575     if (auto ptr_sp =
576             valobj_sp->GetChildMemberWithName(ConstString("__ptr_"), true)) {
577       Status status;
578       auto value_sp = ptr_sp->Dereference(status);
579       if (status.Success()) {
580         auto value_type_sp =
581             valobj_sp->GetCompilerType().GetTypeTemplateArgument(0);
582         return value_sp->Cast(value_type_sp);
583       }
584     }
585   }
586 
587   return lldb::ValueObjectSP();
588 }
589 
Update()590 bool lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd::Update() {
591   m_cntrl = nullptr;
592 
593   ValueObjectSP valobj_sp = m_backend.GetSP();
594   if (!valobj_sp)
595     return false;
596 
597   TargetSP target_sp(valobj_sp->GetTargetSP());
598   if (!target_sp)
599     return false;
600 
601   lldb::ValueObjectSP cntrl_sp(
602       valobj_sp->GetChildMemberWithName(ConstString("__cntrl_"), true));
603 
604   m_cntrl = cntrl_sp.get(); // need to store the raw pointer to avoid a circular
605                             // dependency
606   return false;
607 }
608 
609 bool lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd::
MightHaveChildren()610     MightHaveChildren() {
611   return true;
612 }
613 
614 size_t lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd::
GetIndexOfChildWithName(ConstString name)615     GetIndexOfChildWithName(ConstString name) {
616   if (name == "__ptr_")
617     return 0;
618   if (name == "$$dereference$$")
619     return 1;
620   return UINT32_MAX;
621 }
622 
623 lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEnd::
624     ~LibcxxSharedPtrSyntheticFrontEnd() = default;
625 
626 SyntheticChildrenFrontEnd *
LibcxxSharedPtrSyntheticFrontEndCreator(CXXSyntheticChildren *,lldb::ValueObjectSP valobj_sp)627 lldb_private::formatters::LibcxxSharedPtrSyntheticFrontEndCreator(
628     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
629   return (valobj_sp ? new LibcxxSharedPtrSyntheticFrontEnd(valobj_sp)
630                     : nullptr);
631 }
632 
633 lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::
LibcxxUniquePtrSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)634     LibcxxUniquePtrSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
635     : SyntheticChildrenFrontEnd(*valobj_sp) {
636   if (valobj_sp)
637     Update();
638 }
639 
640 lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::
641     ~LibcxxUniquePtrSyntheticFrontEnd() = default;
642 
643 SyntheticChildrenFrontEnd *
LibcxxUniquePtrSyntheticFrontEndCreator(CXXSyntheticChildren *,lldb::ValueObjectSP valobj_sp)644 lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEndCreator(
645     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
646   return (valobj_sp ? new LibcxxUniquePtrSyntheticFrontEnd(valobj_sp)
647                     : nullptr);
648 }
649 
650 size_t lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::
CalculateNumChildren()651     CalculateNumChildren() {
652   return (m_value_ptr_sp ? 1 : 0);
653 }
654 
655 lldb::ValueObjectSP
GetChildAtIndex(size_t idx)656 lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::GetChildAtIndex(
657     size_t idx) {
658   if (!m_value_ptr_sp)
659     return lldb::ValueObjectSP();
660 
661   if (idx == 0)
662     return m_value_ptr_sp;
663 
664   if (idx == 1) {
665     Status status;
666     auto value_sp = m_value_ptr_sp->Dereference(status);
667     if (status.Success()) {
668       return value_sp;
669     }
670   }
671 
672   return lldb::ValueObjectSP();
673 }
674 
Update()675 bool lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::Update() {
676   ValueObjectSP valobj_sp = m_backend.GetSP();
677   if (!valobj_sp)
678     return false;
679 
680   ValueObjectSP ptr_sp(
681       valobj_sp->GetChildMemberWithName(ConstString("__ptr_"), true));
682   if (!ptr_sp)
683     return false;
684 
685   m_value_ptr_sp = GetValueOfLibCXXCompressedPair(*ptr_sp);
686 
687   return false;
688 }
689 
690 bool lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::
MightHaveChildren()691     MightHaveChildren() {
692   return true;
693 }
694 
695 size_t lldb_private::formatters::LibcxxUniquePtrSyntheticFrontEnd::
GetIndexOfChildWithName(ConstString name)696     GetIndexOfChildWithName(ConstString name) {
697   if (name == "__value_")
698     return 0;
699   if (name == "$$dereference$$")
700     return 1;
701   return UINT32_MAX;
702 }
703 
LibcxxContainerSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & options)704 bool lldb_private::formatters::LibcxxContainerSummaryProvider(
705     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
706   if (valobj.IsPointerType()) {
707     uint64_t value = valobj.GetValueAsUnsigned(0);
708     if (!value)
709       return false;
710     stream.Printf("0x%016" PRIx64 " ", value);
711   }
712   return FormatEntity::FormatStringRef("size=${svar%#}", stream, nullptr,
713                                        nullptr, nullptr, &valobj, false, false);
714 }
715 
716 /// The field layout in a libc++ string (cap, side, data or data, size, cap).
717 namespace {
718 enum class StringLayout { CSD, DSC };
719 }
720 
721 /// Determine the size in bytes of \p valobj (a libc++ std::string object) and
722 /// extract its data payload. Return the size + payload pair.
723 // TODO: Support big-endian architectures.
724 static llvm::Optional<std::pair<uint64_t, ValueObjectSP>>
ExtractLibcxxStringInfo(ValueObject & valobj)725 ExtractLibcxxStringInfo(ValueObject &valobj) {
726   ValueObjectSP valobj_r_sp =
727       valobj.GetChildMemberWithName(ConstString("__r_"), /*can_create=*/true);
728   if (!valobj_r_sp || !valobj_r_sp->GetError().Success())
729     return {};
730 
731   // __r_ is a compressed_pair of the actual data and the allocator. The data we
732   // want is in the first base class.
733   ValueObjectSP valobj_r_base_sp =
734       valobj_r_sp->GetChildAtIndex(0, /*can_create=*/true);
735   if (!valobj_r_base_sp)
736     return {};
737 
738   ValueObjectSP valobj_rep_sp = valobj_r_base_sp->GetChildMemberWithName(
739       ConstString("__value_"), /*can_create=*/true);
740   if (!valobj_rep_sp)
741     return {};
742 
743   ValueObjectSP l = valobj_rep_sp->GetChildMemberWithName(ConstString("__l"),
744                                                           /*can_create=*/true);
745   if (!l)
746     return {};
747 
748   StringLayout layout = l->GetIndexOfChildWithName(ConstString("__data_")) == 0
749                             ? StringLayout::DSC
750                             : StringLayout::CSD;
751 
752   bool short_mode = false; // this means the string is in short-mode and the
753                            // data is stored inline
754   bool using_bitmasks = true; // Whether the class uses bitmasks for the mode
755                               // flag (pre-D123580).
756   uint64_t size;
757   uint64_t size_mode_value = 0;
758 
759   ValueObjectSP short_sp = valobj_rep_sp->GetChildMemberWithName(
760       ConstString("__s"), /*can_create=*/true);
761   if (!short_sp)
762     return {};
763 
764   ValueObjectSP is_long =
765       short_sp->GetChildMemberWithName(ConstString("__is_long_"), true);
766   ValueObjectSP size_sp =
767       short_sp->GetChildAtNamePath({ConstString("__size_")});
768   if (!size_sp)
769     return {};
770 
771   if (is_long) {
772     using_bitmasks = false;
773     short_mode = !is_long->GetValueAsUnsigned(/*fail_value=*/0);
774     size = size_sp->GetValueAsUnsigned(/*fail_value=*/0);
775   } else {
776     // The string mode is encoded in the size field.
777     size_mode_value = size_sp->GetValueAsUnsigned(0);
778     uint8_t mode_mask = layout == StringLayout::DSC ? 0x80 : 1;
779     short_mode = (size_mode_value & mode_mask) == 0;
780   }
781 
782   if (short_mode) {
783     ValueObjectSP location_sp =
784         short_sp->GetChildMemberWithName(ConstString("__data_"), true);
785     if (using_bitmasks)
786       size = (layout == StringLayout::DSC) ? size_mode_value
787                                            : ((size_mode_value >> 1) % 256);
788 
789     // When the small-string optimization takes place, the data must fit in the
790     // inline string buffer (23 bytes on x86_64/Darwin). If it doesn't, it's
791     // likely that the string isn't initialized and we're reading garbage.
792     ExecutionContext exe_ctx(location_sp->GetExecutionContextRef());
793     const llvm::Optional<uint64_t> max_bytes =
794         location_sp->GetCompilerType().GetByteSize(
795             exe_ctx.GetBestExecutionContextScope());
796     if (!max_bytes || size > *max_bytes || !location_sp)
797       return {};
798 
799     return std::make_pair(size, location_sp);
800   }
801 
802   // we can use the layout_decider object as the data pointer
803   ValueObjectSP location_sp =
804       l->GetChildMemberWithName(ConstString("__data_"), /*can_create=*/true);
805   ValueObjectSP size_vo =
806       l->GetChildMemberWithName(ConstString("__size_"), /*can_create=*/true);
807   ValueObjectSP capacity_vo =
808       l->GetChildMemberWithName(ConstString("__cap_"), /*can_create=*/true);
809   if (!size_vo || !location_sp || !capacity_vo)
810     return {};
811   size = size_vo->GetValueAsUnsigned(LLDB_INVALID_OFFSET);
812   uint64_t capacity = capacity_vo->GetValueAsUnsigned(LLDB_INVALID_OFFSET);
813   if (!using_bitmasks && layout == StringLayout::CSD)
814     capacity *= 2;
815   if (size == LLDB_INVALID_OFFSET || capacity == LLDB_INVALID_OFFSET ||
816       capacity < size)
817     return {};
818   return std::make_pair(size, location_sp);
819 }
820 
821 static bool
LibcxxWStringSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options,ValueObjectSP location_sp,size_t size)822 LibcxxWStringSummaryProvider(ValueObject &valobj, Stream &stream,
823                              const TypeSummaryOptions &summary_options,
824                              ValueObjectSP location_sp, size_t size) {
825   if (size == 0) {
826     stream.Printf("L\"\"");
827     return true;
828   }
829   if (!location_sp)
830     return false;
831 
832   StringPrinter::ReadBufferAndDumpToStreamOptions options(valobj);
833   if (summary_options.GetCapping() == TypeSummaryCapping::eTypeSummaryCapped) {
834     const auto max_size = valobj.GetTargetSP()->GetMaximumSizeOfStringSummary();
835     if (size > max_size) {
836       size = max_size;
837       options.SetIsTruncated(true);
838     }
839   }
840 
841   DataExtractor extractor;
842   const size_t bytes_read = location_sp->GetPointeeData(extractor, 0, size);
843   if (bytes_read < size)
844     return false;
845 
846   // std::wstring::size() is measured in 'characters', not bytes
847   TypeSystemClang *ast_context =
848       ScratchTypeSystemClang::GetForTarget(*valobj.GetTargetSP());
849   if (!ast_context)
850     return false;
851 
852   auto wchar_t_size =
853       ast_context->GetBasicType(lldb::eBasicTypeWChar).GetByteSize(nullptr);
854   if (!wchar_t_size)
855     return false;
856 
857   options.SetData(std::move(extractor));
858   options.SetStream(&stream);
859   options.SetPrefixToken("L");
860   options.SetQuote('"');
861   options.SetSourceSize(size);
862   options.SetBinaryZeroIsTerminator(false);
863 
864   switch (*wchar_t_size) {
865   case 1:
866     return StringPrinter::ReadBufferAndDumpToStream<
867         lldb_private::formatters::StringPrinter::StringElementType::UTF8>(
868         options);
869     break;
870 
871   case 2:
872     return StringPrinter::ReadBufferAndDumpToStream<
873         lldb_private::formatters::StringPrinter::StringElementType::UTF16>(
874         options);
875     break;
876 
877   case 4:
878     return StringPrinter::ReadBufferAndDumpToStream<
879         lldb_private::formatters::StringPrinter::StringElementType::UTF32>(
880         options);
881   }
882   return false;
883 }
884 
LibcxxWStringSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)885 bool lldb_private::formatters::LibcxxWStringSummaryProvider(
886     ValueObject &valobj, Stream &stream,
887     const TypeSummaryOptions &summary_options) {
888   auto string_info = ExtractLibcxxStringInfo(valobj);
889   if (!string_info)
890     return false;
891   uint64_t size;
892   ValueObjectSP location_sp;
893   std::tie(size, location_sp) = *string_info;
894 
895   return ::LibcxxWStringSummaryProvider(valobj, stream, summary_options,
896                                         location_sp, size);
897 }
898 
899 template <StringPrinter::StringElementType element_type>
900 static bool
LibcxxStringSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options,std::string prefix_token,ValueObjectSP location_sp,uint64_t size)901 LibcxxStringSummaryProvider(ValueObject &valobj, Stream &stream,
902                             const TypeSummaryOptions &summary_options,
903                             std::string prefix_token, ValueObjectSP location_sp,
904                             uint64_t size) {
905 
906   if (size == 0) {
907     stream.Printf("\"\"");
908     return true;
909   }
910 
911   if (!location_sp)
912     return false;
913 
914   StringPrinter::ReadBufferAndDumpToStreamOptions options(valobj);
915 
916   if (summary_options.GetCapping() == TypeSummaryCapping::eTypeSummaryCapped) {
917     const auto max_size = valobj.GetTargetSP()->GetMaximumSizeOfStringSummary();
918     if (size > max_size) {
919       size = max_size;
920       options.SetIsTruncated(true);
921     }
922   }
923 
924   {
925     DataExtractor extractor;
926     const size_t bytes_read = location_sp->GetPointeeData(extractor, 0, size);
927     if (bytes_read < size)
928       return false;
929 
930     options.SetData(std::move(extractor));
931   }
932   options.SetStream(&stream);
933   if (prefix_token.empty())
934     options.SetPrefixToken(nullptr);
935   else
936     options.SetPrefixToken(prefix_token);
937   options.SetQuote('"');
938   options.SetSourceSize(size);
939   options.SetBinaryZeroIsTerminator(false);
940   return StringPrinter::ReadBufferAndDumpToStream<element_type>(options);
941 }
942 
943 template <StringPrinter::StringElementType element_type>
944 static bool
LibcxxStringSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options,std::string prefix_token)945 LibcxxStringSummaryProvider(ValueObject &valobj, Stream &stream,
946                             const TypeSummaryOptions &summary_options,
947                             std::string prefix_token) {
948   auto string_info = ExtractLibcxxStringInfo(valobj);
949   if (!string_info)
950     return false;
951   uint64_t size;
952   ValueObjectSP location_sp;
953   std::tie(size, location_sp) = *string_info;
954 
955   return LibcxxStringSummaryProvider<element_type>(
956       valobj, stream, summary_options, prefix_token, location_sp, size);
957 }
958 template <StringPrinter::StringElementType element_type>
formatStringImpl(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options,std::string prefix_token)959 static bool formatStringImpl(ValueObject &valobj, Stream &stream,
960                              const TypeSummaryOptions &summary_options,
961                              std::string prefix_token) {
962   StreamString scratch_stream;
963   const bool success = LibcxxStringSummaryProvider<element_type>(
964       valobj, scratch_stream, summary_options, prefix_token);
965   if (success)
966     stream << scratch_stream.GetData();
967   else
968     stream << "Summary Unavailable";
969   return true;
970 }
971 
LibcxxStringSummaryProviderASCII(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)972 bool lldb_private::formatters::LibcxxStringSummaryProviderASCII(
973     ValueObject &valobj, Stream &stream,
974     const TypeSummaryOptions &summary_options) {
975   return formatStringImpl<StringPrinter::StringElementType::ASCII>(
976       valobj, stream, summary_options, "");
977 }
978 
LibcxxStringSummaryProviderUTF16(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)979 bool lldb_private::formatters::LibcxxStringSummaryProviderUTF16(
980     ValueObject &valobj, Stream &stream,
981     const TypeSummaryOptions &summary_options) {
982   return formatStringImpl<StringPrinter::StringElementType::UTF16>(
983       valobj, stream, summary_options, "u");
984 }
985 
LibcxxStringSummaryProviderUTF32(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)986 bool lldb_private::formatters::LibcxxStringSummaryProviderUTF32(
987     ValueObject &valobj, Stream &stream,
988     const TypeSummaryOptions &summary_options) {
989   return formatStringImpl<StringPrinter::StringElementType::UTF32>(
990       valobj, stream, summary_options, "U");
991 }
992 
993 static std::tuple<bool, ValueObjectSP, size_t>
LibcxxExtractStringViewData(ValueObject & valobj)994 LibcxxExtractStringViewData(ValueObject& valobj) {
995   ConstString g_data_name("__data");
996   ConstString g_size_name("__size");
997   auto dataobj = valobj.GetChildMemberWithName(g_data_name, true);
998   auto sizeobj = valobj.GetChildMemberWithName(g_size_name, true);
999 
1000   if (!dataobj || !sizeobj)
1001     return std::make_tuple<bool,ValueObjectSP,size_t>(false, {}, {});
1002 
1003   if (!dataobj->GetError().Success() || !sizeobj->GetError().Success())
1004     return std::make_tuple<bool,ValueObjectSP,size_t>(false, {}, {});
1005 
1006   bool success{false};
1007   uint64_t size = sizeobj->GetValueAsUnsigned(0, &success);
1008   if (!success)
1009     return std::make_tuple<bool,ValueObjectSP,size_t>(false, {}, {});
1010 
1011   return std::make_tuple(true,dataobj,size);
1012 }
1013 
1014 template <StringPrinter::StringElementType element_type>
formatStringViewImpl(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options,std::string prefix_token)1015 static bool formatStringViewImpl(ValueObject &valobj, Stream &stream,
1016                                  const TypeSummaryOptions &summary_options,
1017                                  std::string prefix_token) {
1018 
1019   bool success;
1020   ValueObjectSP dataobj;
1021   size_t size;
1022   std::tie(success, dataobj, size) = LibcxxExtractStringViewData(valobj);
1023 
1024   if (!success) {
1025     stream << "Summary Unavailable";
1026     return true;
1027   }
1028 
1029   return LibcxxStringSummaryProvider<element_type>(
1030       valobj, stream, summary_options, prefix_token, dataobj, size);
1031 }
1032 
LibcxxStringViewSummaryProviderASCII(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)1033 bool lldb_private::formatters::LibcxxStringViewSummaryProviderASCII(
1034     ValueObject &valobj, Stream &stream,
1035     const TypeSummaryOptions &summary_options) {
1036   return formatStringViewImpl<StringPrinter::StringElementType::ASCII>(
1037       valobj, stream, summary_options, "");
1038 }
1039 
LibcxxStringViewSummaryProviderUTF16(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)1040 bool lldb_private::formatters::LibcxxStringViewSummaryProviderUTF16(
1041     ValueObject &valobj, Stream &stream,
1042     const TypeSummaryOptions &summary_options) {
1043   return formatStringViewImpl<StringPrinter::StringElementType::UTF16>(
1044       valobj, stream, summary_options, "u");
1045 }
1046 
LibcxxStringViewSummaryProviderUTF32(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)1047 bool lldb_private::formatters::LibcxxStringViewSummaryProviderUTF32(
1048     ValueObject &valobj, Stream &stream,
1049     const TypeSummaryOptions &summary_options) {
1050   return formatStringViewImpl<StringPrinter::StringElementType::UTF32>(
1051       valobj, stream, summary_options, "U");
1052 }
1053 
LibcxxWStringViewSummaryProvider(ValueObject & valobj,Stream & stream,const TypeSummaryOptions & summary_options)1054 bool lldb_private::formatters::LibcxxWStringViewSummaryProvider(
1055     ValueObject &valobj, Stream &stream,
1056     const TypeSummaryOptions &summary_options) {
1057 
1058   bool success;
1059   ValueObjectSP dataobj;
1060   size_t size;
1061   std::tie( success, dataobj, size ) = LibcxxExtractStringViewData(valobj);
1062 
1063   if (!success) {
1064     stream << "Summary Unavailable";
1065     return true;
1066   }
1067 
1068 
1069   return ::LibcxxWStringSummaryProvider(valobj, stream, summary_options,
1070                                         dataobj, size);
1071 }
1072