xref: /llvm-project/lldb/source/Plugins/Language/CPlusPlus/LibStdcpp.cpp (revision 44bb442fd5be3860e7819cb216621b5ea59970c3)
1 //===-- LibStdcpp.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 "LibStdcpp.h"
10 #include "LibCxx.h"
11 
12 #include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
13 #include "lldb/Core/ValueObject.h"
14 #include "lldb/Core/ValueObjectConstResult.h"
15 #include "lldb/DataFormatters/StringPrinter.h"
16 #include "lldb/DataFormatters/VectorIterator.h"
17 #include "lldb/Target/Target.h"
18 #include "lldb/Utility/DataBufferHeap.h"
19 #include "lldb/Utility/Endian.h"
20 #include "lldb/Utility/Status.h"
21 #include "lldb/Utility/Stream.h"
22 #include <optional>
23 
24 using namespace lldb;
25 using namespace lldb_private;
26 using namespace lldb_private::formatters;
27 
28 namespace {
29 
30 class LibstdcppMapIteratorSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
31   /*
32    (std::_Rb_tree_iterator<std::pair<const int, std::basic_string<char,
33    std::char_traits<char>, std::allocator<char> > > >) ibeg = {
34    (_Base_ptr) _M_node = 0x0000000100103910 {
35    (std::_Rb_tree_color) _M_color = _S_black
36    (std::_Rb_tree_node_base::_Base_ptr) _M_parent = 0x00000001001038c0
37    (std::_Rb_tree_node_base::_Base_ptr) _M_left = 0x0000000000000000
38    (std::_Rb_tree_node_base::_Base_ptr) _M_right = 0x0000000000000000
39    }
40    }
41    */
42 
43 public:
44   explicit LibstdcppMapIteratorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
45 
46   size_t CalculateNumChildren() override;
47 
48   lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
49 
50   bool Update() override;
51 
52   bool MightHaveChildren() override;
53 
54   size_t GetIndexOfChildWithName(ConstString name) override;
55 
56 private:
57   ExecutionContextRef m_exe_ctx_ref;
58   lldb::addr_t m_pair_address = 0;
59   CompilerType m_pair_type;
60   lldb::ValueObjectSP m_pair_sp;
61 };
62 
63 class LibStdcppSharedPtrSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
64 public:
65   explicit LibStdcppSharedPtrSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
66 
67   size_t CalculateNumChildren() override;
68 
69   lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
70 
71   bool Update() override;
72 
73   bool MightHaveChildren() override;
74 
75   size_t GetIndexOfChildWithName(ConstString name) override;
76 private:
77 
78   // The lifetime of a ValueObject and all its derivative ValueObjects
79   // (children, clones, etc.) is managed by a ClusterManager. These
80   // objects are only destroyed when every shared pointer to any of them
81   // is destroyed, so we must not store a shared pointer to any ValueObject
82   // derived from our backend ValueObject (since we're in the same cluster).
83   ValueObject* m_ptr_obj = nullptr; // Underlying pointer (held, not owned)
84   ValueObject* m_obj_obj = nullptr; // Underlying object (held, not owned)
85 };
86 
87 } // end of anonymous namespace
88 
89 LibstdcppMapIteratorSyntheticFrontEnd::LibstdcppMapIteratorSyntheticFrontEnd(
90     lldb::ValueObjectSP valobj_sp)
91     : SyntheticChildrenFrontEnd(*valobj_sp), m_exe_ctx_ref(), m_pair_type(),
92       m_pair_sp() {
93   if (valobj_sp)
94     Update();
95 }
96 
97 bool LibstdcppMapIteratorSyntheticFrontEnd::Update() {
98   ValueObjectSP valobj_sp = m_backend.GetSP();
99   if (!valobj_sp)
100     return false;
101 
102   TargetSP target_sp(valobj_sp->GetTargetSP());
103 
104   if (!target_sp)
105     return false;
106 
107   bool is_64bit = (target_sp->GetArchitecture().GetAddressByteSize() == 8);
108 
109   if (!valobj_sp)
110     return false;
111   m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
112 
113   ValueObjectSP _M_node_sp(
114       valobj_sp->GetChildMemberWithName(ConstString("_M_node"), true));
115   if (!_M_node_sp)
116     return false;
117 
118   m_pair_address = _M_node_sp->GetValueAsUnsigned(0);
119   if (m_pair_address == 0)
120     return false;
121 
122   m_pair_address += (is_64bit ? 32 : 16);
123 
124   CompilerType my_type(valobj_sp->GetCompilerType());
125   if (my_type.GetNumTemplateArguments() >= 1) {
126     CompilerType pair_type = my_type.GetTypeTemplateArgument(0);
127     if (!pair_type)
128       return false;
129     m_pair_type = pair_type;
130   } else
131     return false;
132 
133   return true;
134 }
135 
136 size_t LibstdcppMapIteratorSyntheticFrontEnd::CalculateNumChildren() {
137   return 2;
138 }
139 
140 lldb::ValueObjectSP
141 LibstdcppMapIteratorSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
142   if (m_pair_address != 0 && m_pair_type) {
143     if (!m_pair_sp)
144       m_pair_sp = CreateValueObjectFromAddress("pair", m_pair_address,
145                                                m_exe_ctx_ref, m_pair_type);
146     if (m_pair_sp)
147       return m_pair_sp->GetChildAtIndex(idx, true);
148   }
149   return lldb::ValueObjectSP();
150 }
151 
152 bool LibstdcppMapIteratorSyntheticFrontEnd::MightHaveChildren() { return true; }
153 
154 size_t LibstdcppMapIteratorSyntheticFrontEnd::GetIndexOfChildWithName(
155     ConstString name) {
156   if (name == "first")
157     return 0;
158   if (name == "second")
159     return 1;
160   return UINT32_MAX;
161 }
162 
163 SyntheticChildrenFrontEnd *
164 lldb_private::formatters::LibstdcppMapIteratorSyntheticFrontEndCreator(
165     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
166   return (valobj_sp ? new LibstdcppMapIteratorSyntheticFrontEnd(valobj_sp)
167                     : nullptr);
168 }
169 
170 /*
171  (lldb) fr var ibeg --ptr-depth 1
172  (__gnu_cxx::__normal_iterator<int *, std::vector<int, std::allocator<int> > >)
173  ibeg = {
174  _M_current = 0x00000001001037a0 {
175  *_M_current = 1
176  }
177  }
178  */
179 
180 SyntheticChildrenFrontEnd *
181 lldb_private::formatters::LibStdcppVectorIteratorSyntheticFrontEndCreator(
182     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
183   return (valobj_sp ? new VectorIteratorSyntheticFrontEnd(
184                           valobj_sp, {ConstString("_M_current")})
185                     : nullptr);
186 }
187 
188 lldb_private::formatters::VectorIteratorSyntheticFrontEnd::
189     VectorIteratorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp,
190                                     llvm::ArrayRef<ConstString> item_names)
191     : SyntheticChildrenFrontEnd(*valobj_sp), m_exe_ctx_ref(),
192       m_item_names(item_names), m_item_sp() {
193   if (valobj_sp)
194     Update();
195 }
196 
197 bool VectorIteratorSyntheticFrontEnd::Update() {
198   m_item_sp.reset();
199 
200   ValueObjectSP valobj_sp = m_backend.GetSP();
201   if (!valobj_sp)
202     return false;
203 
204   if (!valobj_sp)
205     return false;
206 
207   ValueObjectSP item_ptr =
208       formatters::GetChildMemberWithName(*valobj_sp, m_item_names);
209   if (!item_ptr)
210     return false;
211   if (item_ptr->GetValueAsUnsigned(0) == 0)
212     return false;
213   Status err;
214   m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
215   m_item_sp = CreateValueObjectFromAddress(
216       "item", item_ptr->GetValueAsUnsigned(0), m_exe_ctx_ref,
217       item_ptr->GetCompilerType().GetPointeeType());
218   if (err.Fail())
219     m_item_sp.reset();
220   return false;
221 }
222 
223 size_t VectorIteratorSyntheticFrontEnd::CalculateNumChildren() { return 1; }
224 
225 lldb::ValueObjectSP
226 VectorIteratorSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
227   if (idx == 0)
228     return m_item_sp;
229   return lldb::ValueObjectSP();
230 }
231 
232 bool VectorIteratorSyntheticFrontEnd::MightHaveChildren() { return true; }
233 
234 size_t VectorIteratorSyntheticFrontEnd::GetIndexOfChildWithName(
235     ConstString name) {
236   if (name == "item")
237     return 0;
238   return UINT32_MAX;
239 }
240 
241 bool lldb_private::formatters::LibStdcppStringSummaryProvider(
242     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
243   const bool scalar_is_load_addr = true;
244   AddressType addr_type;
245   lldb::addr_t addr_of_string = LLDB_INVALID_ADDRESS;
246   if (valobj.IsPointerOrReferenceType()) {
247     Status error;
248     ValueObjectSP pointee_sp = valobj.Dereference(error);
249     if (pointee_sp && error.Success())
250       addr_of_string = pointee_sp->GetAddressOf(scalar_is_load_addr, &addr_type);
251   } else
252     addr_of_string =
253         valobj.GetAddressOf(scalar_is_load_addr, &addr_type);
254   if (addr_of_string != LLDB_INVALID_ADDRESS) {
255     switch (addr_type) {
256     case eAddressTypeLoad: {
257       ProcessSP process_sp(valobj.GetProcessSP());
258       if (!process_sp)
259         return false;
260 
261       StringPrinter::ReadStringAndDumpToStreamOptions options(valobj);
262       Status error;
263       lldb::addr_t addr_of_data =
264           process_sp->ReadPointerFromMemory(addr_of_string, error);
265       if (error.Fail() || addr_of_data == 0 ||
266           addr_of_data == LLDB_INVALID_ADDRESS)
267         return false;
268       options.SetLocation(addr_of_data);
269       options.SetTargetSP(valobj.GetTargetSP());
270       options.SetStream(&stream);
271       options.SetNeedsZeroTermination(false);
272       options.SetBinaryZeroIsTerminator(true);
273       lldb::addr_t size_of_data = process_sp->ReadPointerFromMemory(
274           addr_of_string + process_sp->GetAddressByteSize(), error);
275       if (error.Fail())
276         return false;
277       options.SetSourceSize(size_of_data);
278       options.SetHasSourceSize(true);
279 
280       if (!StringPrinter::ReadStringAndDumpToStream<
281               StringPrinter::StringElementType::UTF8>(options)) {
282         stream.Printf("Summary Unavailable");
283         return true;
284       } else
285         return true;
286     } break;
287     case eAddressTypeHost:
288       break;
289     case eAddressTypeInvalid:
290     case eAddressTypeFile:
291       break;
292     }
293   }
294   return false;
295 }
296 
297 bool lldb_private::formatters::LibStdcppWStringSummaryProvider(
298     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
299   const bool scalar_is_load_addr = true;
300   AddressType addr_type;
301   lldb::addr_t addr_of_string =
302       valobj.GetAddressOf(scalar_is_load_addr, &addr_type);
303   if (addr_of_string != LLDB_INVALID_ADDRESS) {
304     switch (addr_type) {
305     case eAddressTypeLoad: {
306       ProcessSP process_sp(valobj.GetProcessSP());
307       if (!process_sp)
308         return false;
309 
310       CompilerType wchar_compiler_type =
311           valobj.GetCompilerType().GetBasicTypeFromAST(lldb::eBasicTypeWChar);
312 
313       if (!wchar_compiler_type)
314         return false;
315 
316       // Safe to pass nullptr for exe_scope here.
317       std::optional<uint64_t> size = wchar_compiler_type.GetBitSize(nullptr);
318       if (!size)
319         return false;
320       const uint32_t wchar_size = *size;
321 
322       StringPrinter::ReadStringAndDumpToStreamOptions options(valobj);
323       Status error;
324       lldb::addr_t addr_of_data =
325           process_sp->ReadPointerFromMemory(addr_of_string, error);
326       if (error.Fail() || addr_of_data == 0 ||
327           addr_of_data == LLDB_INVALID_ADDRESS)
328         return false;
329       options.SetLocation(addr_of_data);
330       options.SetTargetSP(valobj.GetTargetSP());
331       options.SetStream(&stream);
332       options.SetNeedsZeroTermination(false);
333       options.SetBinaryZeroIsTerminator(false);
334       lldb::addr_t size_of_data = process_sp->ReadPointerFromMemory(
335           addr_of_string + process_sp->GetAddressByteSize(), error);
336       if (error.Fail())
337         return false;
338       options.SetSourceSize(size_of_data);
339       options.SetHasSourceSize(true);
340       options.SetPrefixToken("L");
341 
342       switch (wchar_size) {
343       case 8:
344         return StringPrinter::ReadStringAndDumpToStream<
345             StringPrinter::StringElementType::UTF8>(options);
346       case 16:
347         return StringPrinter::ReadStringAndDumpToStream<
348             StringPrinter::StringElementType::UTF16>(options);
349       case 32:
350         return StringPrinter::ReadStringAndDumpToStream<
351             StringPrinter::StringElementType::UTF32>(options);
352       default:
353         stream.Printf("size for wchar_t is not valid");
354         return true;
355       }
356       return true;
357     } break;
358     case eAddressTypeHost:
359       break;
360     case eAddressTypeInvalid:
361     case eAddressTypeFile:
362       break;
363     }
364   }
365   return false;
366 }
367 
368 LibStdcppSharedPtrSyntheticFrontEnd::LibStdcppSharedPtrSyntheticFrontEnd(
369     lldb::ValueObjectSP valobj_sp)
370     : SyntheticChildrenFrontEnd(*valobj_sp) {
371   if (valobj_sp)
372     Update();
373 }
374 
375 size_t LibStdcppSharedPtrSyntheticFrontEnd::CalculateNumChildren() { return 1; }
376 
377 lldb::ValueObjectSP
378 LibStdcppSharedPtrSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
379   if (idx == 0)
380     return m_ptr_obj->GetSP();
381   if (idx == 1)
382     return m_obj_obj->GetSP();
383 
384   return lldb::ValueObjectSP();
385 }
386 
387 bool LibStdcppSharedPtrSyntheticFrontEnd::Update() {
388   auto backend = m_backend.GetSP();
389   if (!backend)
390     return false;
391 
392   auto valobj_sp = backend->GetNonSyntheticValue();
393   if (!valobj_sp)
394     return false;
395 
396   auto ptr_obj_sp = valobj_sp->GetChildMemberWithName(ConstString("_M_ptr"), true);
397   if (!ptr_obj_sp)
398     return false;
399 
400   m_ptr_obj = ptr_obj_sp->Clone(ConstString("pointer")).get();
401 
402   if (m_ptr_obj) {
403     Status error;
404     ValueObjectSP obj_obj = m_ptr_obj->Dereference(error);
405     if (error.Success()) {
406       m_obj_obj = obj_obj->Clone(ConstString("object")).get();
407     }
408   }
409 
410   return false;
411 }
412 
413 bool LibStdcppSharedPtrSyntheticFrontEnd::MightHaveChildren() { return true; }
414 
415 size_t LibStdcppSharedPtrSyntheticFrontEnd::GetIndexOfChildWithName(
416     ConstString name) {
417   if (name == "pointer")
418     return 0;
419   if (name == "object" || name == "$$dereference$$")
420     return 1;
421   return UINT32_MAX;
422 }
423 
424 SyntheticChildrenFrontEnd *
425 lldb_private::formatters::LibStdcppSharedPtrSyntheticFrontEndCreator(
426     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
427   return (valobj_sp ? new LibStdcppSharedPtrSyntheticFrontEnd(valobj_sp)
428                     : nullptr);
429 }
430 
431 bool lldb_private::formatters::LibStdcppSmartPointerSummaryProvider(
432     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
433   ValueObjectSP valobj_sp(valobj.GetNonSyntheticValue());
434   if (!valobj_sp)
435     return false;
436 
437   ValueObjectSP ptr_sp(
438       valobj_sp->GetChildMemberWithName(ConstString("_M_ptr"), true));
439   if (!ptr_sp)
440     return false;
441 
442   ValueObjectSP usecount_sp(valobj_sp->GetChildAtNamePath(
443       {ConstString("_M_refcount"), ConstString("_M_pi"),
444        ConstString("_M_use_count")}));
445   if (!usecount_sp)
446     return false;
447 
448   if (ptr_sp->GetValueAsUnsigned(0) == 0 ||
449       usecount_sp->GetValueAsUnsigned(0) == 0) {
450     stream.Printf("nullptr");
451     return true;
452   }
453 
454   Status error;
455   ValueObjectSP pointee_sp = ptr_sp->Dereference(error);
456   if (pointee_sp && error.Success()) {
457     if (pointee_sp->DumpPrintableRepresentation(
458             stream, ValueObject::eValueObjectRepresentationStyleSummary,
459             lldb::eFormatInvalid,
460             ValueObject::PrintableRepresentationSpecialCases::eDisable,
461             false)) {
462       return true;
463     }
464   }
465 
466   stream.Printf("ptr = 0x%" PRIx64, ptr_sp->GetValueAsUnsigned(0));
467   return true;
468 }
469