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(valobj_sp->GetChildMemberWithName("_M_node"));
114   if (!_M_node_sp)
115     return false;
116 
117   m_pair_address = _M_node_sp->GetValueAsUnsigned(0);
118   if (m_pair_address == 0)
119     return false;
120 
121   m_pair_address += (is_64bit ? 32 : 16);
122 
123   CompilerType my_type(valobj_sp->GetCompilerType());
124   if (my_type.GetNumTemplateArguments() >= 1) {
125     CompilerType pair_type = my_type.GetTypeTemplateArgument(0);
126     if (!pair_type)
127       return false;
128     m_pair_type = pair_type;
129   } else
130     return false;
131 
132   return true;
133 }
134 
135 size_t LibstdcppMapIteratorSyntheticFrontEnd::CalculateNumChildren() {
136   return 2;
137 }
138 
139 lldb::ValueObjectSP
140 LibstdcppMapIteratorSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
141   if (m_pair_address != 0 && m_pair_type) {
142     if (!m_pair_sp)
143       m_pair_sp = CreateValueObjectFromAddress("pair", m_pair_address,
144                                                m_exe_ctx_ref, m_pair_type);
145     if (m_pair_sp)
146       return m_pair_sp->GetChildAtIndex(idx);
147   }
148   return lldb::ValueObjectSP();
149 }
150 
151 bool LibstdcppMapIteratorSyntheticFrontEnd::MightHaveChildren() { return true; }
152 
153 size_t LibstdcppMapIteratorSyntheticFrontEnd::GetIndexOfChildWithName(
154     ConstString name) {
155   if (name == "first")
156     return 0;
157   if (name == "second")
158     return 1;
159   return UINT32_MAX;
160 }
161 
162 SyntheticChildrenFrontEnd *
163 lldb_private::formatters::LibstdcppMapIteratorSyntheticFrontEndCreator(
164     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
165   return (valobj_sp ? new LibstdcppMapIteratorSyntheticFrontEnd(valobj_sp)
166                     : nullptr);
167 }
168 
169 /*
170  (lldb) fr var ibeg --ptr-depth 1
171  (__gnu_cxx::__normal_iterator<int *, std::vector<int, std::allocator<int> > >)
172  ibeg = {
173  _M_current = 0x00000001001037a0 {
174  *_M_current = 1
175  }
176  }
177  */
178 
179 SyntheticChildrenFrontEnd *
180 lldb_private::formatters::LibStdcppVectorIteratorSyntheticFrontEndCreator(
181     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
182   return (valobj_sp ? new VectorIteratorSyntheticFrontEnd(
183                           valobj_sp, {ConstString("_M_current")})
184                     : nullptr);
185 }
186 
187 lldb_private::formatters::VectorIteratorSyntheticFrontEnd::
188     VectorIteratorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp,
189                                     llvm::ArrayRef<ConstString> item_names)
190     : SyntheticChildrenFrontEnd(*valobj_sp), m_exe_ctx_ref(),
191       m_item_names(item_names), m_item_sp() {
192   if (valobj_sp)
193     Update();
194 }
195 
196 bool VectorIteratorSyntheticFrontEnd::Update() {
197   m_item_sp.reset();
198 
199   ValueObjectSP valobj_sp = m_backend.GetSP();
200   if (!valobj_sp)
201     return false;
202 
203   if (!valobj_sp)
204     return false;
205 
206   ValueObjectSP item_ptr =
207       formatters::GetChildMemberWithName(*valobj_sp, m_item_names);
208   if (!item_ptr)
209     return false;
210   if (item_ptr->GetValueAsUnsigned(0) == 0)
211     return false;
212   Status err;
213   m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
214   m_item_sp = CreateValueObjectFromAddress(
215       "item", item_ptr->GetValueAsUnsigned(0), m_exe_ctx_ref,
216       item_ptr->GetCompilerType().GetPointeeType());
217   if (err.Fail())
218     m_item_sp.reset();
219   return false;
220 }
221 
222 size_t VectorIteratorSyntheticFrontEnd::CalculateNumChildren() { return 1; }
223 
224 lldb::ValueObjectSP
225 VectorIteratorSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
226   if (idx == 0)
227     return m_item_sp;
228   return lldb::ValueObjectSP();
229 }
230 
231 bool VectorIteratorSyntheticFrontEnd::MightHaveChildren() { return true; }
232 
233 size_t VectorIteratorSyntheticFrontEnd::GetIndexOfChildWithName(
234     ConstString name) {
235   if (name == "item")
236     return 0;
237   return UINT32_MAX;
238 }
239 
240 bool lldb_private::formatters::LibStdcppStringSummaryProvider(
241     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
242   const bool scalar_is_load_addr = true;
243   AddressType addr_type;
244   lldb::addr_t addr_of_string = LLDB_INVALID_ADDRESS;
245   if (valobj.IsPointerOrReferenceType()) {
246     Status error;
247     ValueObjectSP pointee_sp = valobj.Dereference(error);
248     if (pointee_sp && error.Success())
249       addr_of_string = pointee_sp->GetAddressOf(scalar_is_load_addr, &addr_type);
250   } else
251     addr_of_string =
252         valobj.GetAddressOf(scalar_is_load_addr, &addr_type);
253   if (addr_of_string != LLDB_INVALID_ADDRESS) {
254     switch (addr_type) {
255     case eAddressTypeLoad: {
256       ProcessSP process_sp(valobj.GetProcessSP());
257       if (!process_sp)
258         return false;
259 
260       StringPrinter::ReadStringAndDumpToStreamOptions options(valobj);
261       Status error;
262       lldb::addr_t addr_of_data =
263           process_sp->ReadPointerFromMemory(addr_of_string, error);
264       if (error.Fail() || addr_of_data == 0 ||
265           addr_of_data == LLDB_INVALID_ADDRESS)
266         return false;
267       options.SetLocation(addr_of_data);
268       options.SetTargetSP(valobj.GetTargetSP());
269       options.SetStream(&stream);
270       options.SetNeedsZeroTermination(false);
271       options.SetBinaryZeroIsTerminator(true);
272       lldb::addr_t size_of_data = process_sp->ReadPointerFromMemory(
273           addr_of_string + process_sp->GetAddressByteSize(), error);
274       if (error.Fail())
275         return false;
276       options.SetSourceSize(size_of_data);
277       options.SetHasSourceSize(true);
278 
279       if (!StringPrinter::ReadStringAndDumpToStream<
280               StringPrinter::StringElementType::UTF8>(options)) {
281         stream.Printf("Summary Unavailable");
282         return true;
283       } else
284         return true;
285     } break;
286     case eAddressTypeHost:
287       break;
288     case eAddressTypeInvalid:
289     case eAddressTypeFile:
290       break;
291     }
292   }
293   return false;
294 }
295 
296 bool lldb_private::formatters::LibStdcppWStringSummaryProvider(
297     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
298   const bool scalar_is_load_addr = true;
299   AddressType addr_type;
300   lldb::addr_t addr_of_string =
301       valobj.GetAddressOf(scalar_is_load_addr, &addr_type);
302   if (addr_of_string != LLDB_INVALID_ADDRESS) {
303     switch (addr_type) {
304     case eAddressTypeLoad: {
305       ProcessSP process_sp(valobj.GetProcessSP());
306       if (!process_sp)
307         return false;
308 
309       CompilerType wchar_compiler_type =
310           valobj.GetCompilerType().GetBasicTypeFromAST(lldb::eBasicTypeWChar);
311 
312       if (!wchar_compiler_type)
313         return false;
314 
315       // Safe to pass nullptr for exe_scope here.
316       std::optional<uint64_t> size = wchar_compiler_type.GetBitSize(nullptr);
317       if (!size)
318         return false;
319       const uint32_t wchar_size = *size;
320 
321       StringPrinter::ReadStringAndDumpToStreamOptions options(valobj);
322       Status error;
323       lldb::addr_t addr_of_data =
324           process_sp->ReadPointerFromMemory(addr_of_string, error);
325       if (error.Fail() || addr_of_data == 0 ||
326           addr_of_data == LLDB_INVALID_ADDRESS)
327         return false;
328       options.SetLocation(addr_of_data);
329       options.SetTargetSP(valobj.GetTargetSP());
330       options.SetStream(&stream);
331       options.SetNeedsZeroTermination(false);
332       options.SetBinaryZeroIsTerminator(false);
333       lldb::addr_t size_of_data = process_sp->ReadPointerFromMemory(
334           addr_of_string + process_sp->GetAddressByteSize(), error);
335       if (error.Fail())
336         return false;
337       options.SetSourceSize(size_of_data);
338       options.SetHasSourceSize(true);
339       options.SetPrefixToken("L");
340 
341       switch (wchar_size) {
342       case 8:
343         return StringPrinter::ReadStringAndDumpToStream<
344             StringPrinter::StringElementType::UTF8>(options);
345       case 16:
346         return StringPrinter::ReadStringAndDumpToStream<
347             StringPrinter::StringElementType::UTF16>(options);
348       case 32:
349         return StringPrinter::ReadStringAndDumpToStream<
350             StringPrinter::StringElementType::UTF32>(options);
351       default:
352         stream.Printf("size for wchar_t is not valid");
353         return true;
354       }
355       return true;
356     } break;
357     case eAddressTypeHost:
358       break;
359     case eAddressTypeInvalid:
360     case eAddressTypeFile:
361       break;
362     }
363   }
364   return false;
365 }
366 
367 LibStdcppSharedPtrSyntheticFrontEnd::LibStdcppSharedPtrSyntheticFrontEnd(
368     lldb::ValueObjectSP valobj_sp)
369     : SyntheticChildrenFrontEnd(*valobj_sp) {
370   if (valobj_sp)
371     Update();
372 }
373 
374 size_t LibStdcppSharedPtrSyntheticFrontEnd::CalculateNumChildren() { return 1; }
375 
376 lldb::ValueObjectSP
377 LibStdcppSharedPtrSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
378   if (idx == 0)
379     return m_ptr_obj->GetSP();
380   if (idx == 1)
381     return m_obj_obj->GetSP();
382 
383   return lldb::ValueObjectSP();
384 }
385 
386 bool LibStdcppSharedPtrSyntheticFrontEnd::Update() {
387   auto backend = m_backend.GetSP();
388   if (!backend)
389     return false;
390 
391   auto valobj_sp = backend->GetNonSyntheticValue();
392   if (!valobj_sp)
393     return false;
394 
395   auto ptr_obj_sp = valobj_sp->GetChildMemberWithName("_M_ptr");
396   if (!ptr_obj_sp)
397     return false;
398 
399   m_ptr_obj = ptr_obj_sp->Clone(ConstString("pointer")).get();
400 
401   if (m_ptr_obj) {
402     Status error;
403     ValueObjectSP obj_obj = m_ptr_obj->Dereference(error);
404     if (error.Success()) {
405       m_obj_obj = obj_obj->Clone(ConstString("object")).get();
406     }
407   }
408 
409   return false;
410 }
411 
412 bool LibStdcppSharedPtrSyntheticFrontEnd::MightHaveChildren() { return true; }
413 
414 size_t LibStdcppSharedPtrSyntheticFrontEnd::GetIndexOfChildWithName(
415     ConstString name) {
416   if (name == "pointer")
417     return 0;
418   if (name == "object" || name == "$$dereference$$")
419     return 1;
420   return UINT32_MAX;
421 }
422 
423 SyntheticChildrenFrontEnd *
424 lldb_private::formatters::LibStdcppSharedPtrSyntheticFrontEndCreator(
425     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
426   return (valobj_sp ? new LibStdcppSharedPtrSyntheticFrontEnd(valobj_sp)
427                     : nullptr);
428 }
429 
430 bool lldb_private::formatters::LibStdcppSmartPointerSummaryProvider(
431     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
432   ValueObjectSP valobj_sp(valobj.GetNonSyntheticValue());
433   if (!valobj_sp)
434     return false;
435 
436   ValueObjectSP ptr_sp(valobj_sp->GetChildMemberWithName("_M_ptr"));
437   if (!ptr_sp)
438     return false;
439 
440   ValueObjectSP usecount_sp(
441       valobj_sp->GetChildAtNamePath({"_M_refcount", "_M_pi", "_M_use_count"}));
442   if (!usecount_sp)
443     return false;
444 
445   if (ptr_sp->GetValueAsUnsigned(0) == 0 ||
446       usecount_sp->GetValueAsUnsigned(0) == 0) {
447     stream.Printf("nullptr");
448     return true;
449   }
450 
451   Status error;
452   ValueObjectSP pointee_sp = ptr_sp->Dereference(error);
453   if (pointee_sp && error.Success()) {
454     if (pointee_sp->DumpPrintableRepresentation(
455             stream, ValueObject::eValueObjectRepresentationStyleSummary,
456             lldb::eFormatInvalid,
457             ValueObject::PrintableRepresentationSpecialCases::eDisable,
458             false)) {
459       return true;
460     }
461   }
462 
463   stream.Printf("ptr = 0x%" PRIx64, ptr_sp->GetValueAsUnsigned(0));
464   return true;
465 }
466