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 };
77 
78 } // end of anonymous namespace
79 
80 LibstdcppMapIteratorSyntheticFrontEnd::LibstdcppMapIteratorSyntheticFrontEnd(
81     lldb::ValueObjectSP valobj_sp)
82     : SyntheticChildrenFrontEnd(*valobj_sp), m_exe_ctx_ref(), m_pair_type(),
83       m_pair_sp() {
84   if (valobj_sp)
85     Update();
86 }
87 
88 bool LibstdcppMapIteratorSyntheticFrontEnd::Update() {
89   ValueObjectSP valobj_sp = m_backend.GetSP();
90   if (!valobj_sp)
91     return false;
92 
93   TargetSP target_sp(valobj_sp->GetTargetSP());
94 
95   if (!target_sp)
96     return false;
97 
98   bool is_64bit = (target_sp->GetArchitecture().GetAddressByteSize() == 8);
99 
100   if (!valobj_sp)
101     return false;
102   m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
103 
104   ValueObjectSP _M_node_sp(
105       valobj_sp->GetChildMemberWithName(ConstString("_M_node"), true));
106   if (!_M_node_sp)
107     return false;
108 
109   m_pair_address = _M_node_sp->GetValueAsUnsigned(0);
110   if (m_pair_address == 0)
111     return false;
112 
113   m_pair_address += (is_64bit ? 32 : 16);
114 
115   CompilerType my_type(valobj_sp->GetCompilerType());
116   if (my_type.GetNumTemplateArguments() >= 1) {
117     CompilerType pair_type = my_type.GetTypeTemplateArgument(0);
118     if (!pair_type)
119       return false;
120     m_pair_type = pair_type;
121   } else
122     return false;
123 
124   return true;
125 }
126 
127 size_t LibstdcppMapIteratorSyntheticFrontEnd::CalculateNumChildren() {
128   return 2;
129 }
130 
131 lldb::ValueObjectSP
132 LibstdcppMapIteratorSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
133   if (m_pair_address != 0 && m_pair_type) {
134     if (!m_pair_sp)
135       m_pair_sp = CreateValueObjectFromAddress("pair", m_pair_address,
136                                                m_exe_ctx_ref, m_pair_type);
137     if (m_pair_sp)
138       return m_pair_sp->GetChildAtIndex(idx, true);
139   }
140   return lldb::ValueObjectSP();
141 }
142 
143 bool LibstdcppMapIteratorSyntheticFrontEnd::MightHaveChildren() { return true; }
144 
145 size_t LibstdcppMapIteratorSyntheticFrontEnd::GetIndexOfChildWithName(
146     ConstString name) {
147   if (name == "first")
148     return 0;
149   if (name == "second")
150     return 1;
151   return UINT32_MAX;
152 }
153 
154 SyntheticChildrenFrontEnd *
155 lldb_private::formatters::LibstdcppMapIteratorSyntheticFrontEndCreator(
156     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
157   return (valobj_sp ? new LibstdcppMapIteratorSyntheticFrontEnd(valobj_sp)
158                     : nullptr);
159 }
160 
161 /*
162  (lldb) fr var ibeg --ptr-depth 1
163  (__gnu_cxx::__normal_iterator<int *, std::vector<int, std::allocator<int> > >)
164  ibeg = {
165  _M_current = 0x00000001001037a0 {
166  *_M_current = 1
167  }
168  }
169  */
170 
171 SyntheticChildrenFrontEnd *
172 lldb_private::formatters::LibStdcppVectorIteratorSyntheticFrontEndCreator(
173     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
174   return (valobj_sp ? new VectorIteratorSyntheticFrontEnd(
175                           valobj_sp, {ConstString("_M_current")})
176                     : nullptr);
177 }
178 
179 lldb_private::formatters::VectorIteratorSyntheticFrontEnd::
180     VectorIteratorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp,
181                                     llvm::ArrayRef<ConstString> item_names)
182     : SyntheticChildrenFrontEnd(*valobj_sp), m_exe_ctx_ref(),
183       m_item_names(item_names), m_item_sp() {
184   if (valobj_sp)
185     Update();
186 }
187 
188 bool VectorIteratorSyntheticFrontEnd::Update() {
189   m_item_sp.reset();
190 
191   ValueObjectSP valobj_sp = m_backend.GetSP();
192   if (!valobj_sp)
193     return false;
194 
195   if (!valobj_sp)
196     return false;
197 
198   ValueObjectSP item_ptr =
199       formatters::GetChildMemberWithName(*valobj_sp, m_item_names);
200   if (!item_ptr)
201     return false;
202   if (item_ptr->GetValueAsUnsigned(0) == 0)
203     return false;
204   Status err;
205   m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
206   m_item_sp = CreateValueObjectFromAddress(
207       "item", item_ptr->GetValueAsUnsigned(0), m_exe_ctx_ref,
208       item_ptr->GetCompilerType().GetPointeeType());
209   if (err.Fail())
210     m_item_sp.reset();
211   return false;
212 }
213 
214 size_t VectorIteratorSyntheticFrontEnd::CalculateNumChildren() { return 1; }
215 
216 lldb::ValueObjectSP
217 VectorIteratorSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
218   if (idx == 0)
219     return m_item_sp;
220   return lldb::ValueObjectSP();
221 }
222 
223 bool VectorIteratorSyntheticFrontEnd::MightHaveChildren() { return true; }
224 
225 size_t VectorIteratorSyntheticFrontEnd::GetIndexOfChildWithName(
226     ConstString name) {
227   if (name == "item")
228     return 0;
229   return UINT32_MAX;
230 }
231 
232 bool lldb_private::formatters::LibStdcppStringSummaryProvider(
233     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
234   const bool scalar_is_load_addr = true;
235   AddressType addr_type;
236   lldb::addr_t addr_of_string =
237       valobj.GetAddressOf(scalar_is_load_addr, &addr_type);
238   if (addr_of_string != LLDB_INVALID_ADDRESS) {
239     switch (addr_type) {
240     case eAddressTypeLoad: {
241       ProcessSP process_sp(valobj.GetProcessSP());
242       if (!process_sp)
243         return false;
244 
245       StringPrinter::ReadStringAndDumpToStreamOptions options(valobj);
246       Status error;
247       lldb::addr_t addr_of_data =
248           process_sp->ReadPointerFromMemory(addr_of_string, error);
249       if (error.Fail() || addr_of_data == 0 ||
250           addr_of_data == LLDB_INVALID_ADDRESS)
251         return false;
252       options.SetLocation(addr_of_data);
253       options.SetTargetSP(valobj.GetTargetSP());
254       options.SetStream(&stream);
255       options.SetNeedsZeroTermination(false);
256       options.SetBinaryZeroIsTerminator(true);
257       lldb::addr_t size_of_data = process_sp->ReadPointerFromMemory(
258           addr_of_string + process_sp->GetAddressByteSize(), error);
259       if (error.Fail())
260         return false;
261       options.SetSourceSize(size_of_data);
262       options.SetHasSourceSize(true);
263 
264       if (!StringPrinter::ReadStringAndDumpToStream<
265               StringPrinter::StringElementType::UTF8>(options)) {
266         stream.Printf("Summary Unavailable");
267         return true;
268       } else
269         return true;
270     } break;
271     case eAddressTypeHost:
272       break;
273     case eAddressTypeInvalid:
274     case eAddressTypeFile:
275       break;
276     }
277   }
278   return false;
279 }
280 
281 bool lldb_private::formatters::LibStdcppWStringSummaryProvider(
282     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
283   const bool scalar_is_load_addr = true;
284   AddressType addr_type;
285   lldb::addr_t addr_of_string =
286       valobj.GetAddressOf(scalar_is_load_addr, &addr_type);
287   if (addr_of_string != LLDB_INVALID_ADDRESS) {
288     switch (addr_type) {
289     case eAddressTypeLoad: {
290       ProcessSP process_sp(valobj.GetProcessSP());
291       if (!process_sp)
292         return false;
293 
294       CompilerType wchar_compiler_type =
295           valobj.GetCompilerType().GetBasicTypeFromAST(lldb::eBasicTypeWChar);
296 
297       if (!wchar_compiler_type)
298         return false;
299 
300       // Safe to pass nullptr for exe_scope here.
301       std::optional<uint64_t> size = wchar_compiler_type.GetBitSize(nullptr);
302       if (!size)
303         return false;
304       const uint32_t wchar_size = *size;
305 
306       StringPrinter::ReadStringAndDumpToStreamOptions options(valobj);
307       Status error;
308       lldb::addr_t addr_of_data =
309           process_sp->ReadPointerFromMemory(addr_of_string, error);
310       if (error.Fail() || addr_of_data == 0 ||
311           addr_of_data == LLDB_INVALID_ADDRESS)
312         return false;
313       options.SetLocation(addr_of_data);
314       options.SetTargetSP(valobj.GetTargetSP());
315       options.SetStream(&stream);
316       options.SetNeedsZeroTermination(false);
317       options.SetBinaryZeroIsTerminator(false);
318       lldb::addr_t size_of_data = process_sp->ReadPointerFromMemory(
319           addr_of_string + process_sp->GetAddressByteSize(), error);
320       if (error.Fail())
321         return false;
322       options.SetSourceSize(size_of_data);
323       options.SetHasSourceSize(true);
324       options.SetPrefixToken("L");
325 
326       switch (wchar_size) {
327       case 8:
328         return StringPrinter::ReadStringAndDumpToStream<
329             StringPrinter::StringElementType::UTF8>(options);
330       case 16:
331         return StringPrinter::ReadStringAndDumpToStream<
332             StringPrinter::StringElementType::UTF16>(options);
333       case 32:
334         return StringPrinter::ReadStringAndDumpToStream<
335             StringPrinter::StringElementType::UTF32>(options);
336       default:
337         stream.Printf("size for wchar_t is not valid");
338         return true;
339       }
340       return true;
341     } break;
342     case eAddressTypeHost:
343       break;
344     case eAddressTypeInvalid:
345     case eAddressTypeFile:
346       break;
347     }
348   }
349   return false;
350 }
351 
352 LibStdcppSharedPtrSyntheticFrontEnd::LibStdcppSharedPtrSyntheticFrontEnd(
353     lldb::ValueObjectSP valobj_sp)
354     : SyntheticChildrenFrontEnd(*valobj_sp) {
355   if (valobj_sp)
356     Update();
357 }
358 
359 size_t LibStdcppSharedPtrSyntheticFrontEnd::CalculateNumChildren() { return 1; }
360 
361 lldb::ValueObjectSP
362 LibStdcppSharedPtrSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
363   ValueObjectSP valobj_sp = m_backend.GetSP();
364   if (!valobj_sp)
365     return lldb::ValueObjectSP();
366 
367   if (idx == 0)
368     return valobj_sp->GetChildMemberWithName(ConstString("_M_ptr"), true);
369   else
370     return lldb::ValueObjectSP();
371 }
372 
373 bool LibStdcppSharedPtrSyntheticFrontEnd::Update() { return false; }
374 
375 bool LibStdcppSharedPtrSyntheticFrontEnd::MightHaveChildren() { return true; }
376 
377 size_t LibStdcppSharedPtrSyntheticFrontEnd::GetIndexOfChildWithName(
378     ConstString name) {
379   if (name == "_M_ptr")
380     return 0;
381   return UINT32_MAX;
382 }
383 
384 SyntheticChildrenFrontEnd *
385 lldb_private::formatters::LibStdcppSharedPtrSyntheticFrontEndCreator(
386     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
387   return (valobj_sp ? new LibStdcppSharedPtrSyntheticFrontEnd(valobj_sp)
388                     : nullptr);
389 }
390 
391 bool lldb_private::formatters::LibStdcppSmartPointerSummaryProvider(
392     ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
393   ValueObjectSP valobj_sp(valobj.GetNonSyntheticValue());
394   if (!valobj_sp)
395     return false;
396 
397   ValueObjectSP ptr_sp(
398       valobj_sp->GetChildMemberWithName(ConstString("_M_ptr"), true));
399   if (!ptr_sp)
400     return false;
401 
402   ValueObjectSP usecount_sp(valobj_sp->GetChildAtNamePath(
403       {ConstString("_M_refcount"), ConstString("_M_pi"),
404        ConstString("_M_use_count")}));
405   if (!usecount_sp)
406     return false;
407 
408   if (ptr_sp->GetValueAsUnsigned(0) == 0 ||
409       usecount_sp->GetValueAsUnsigned(0) == 0) {
410     stream.Printf("nullptr");
411     return true;
412   }
413 
414   Status error;
415   ValueObjectSP pointee_sp = ptr_sp->Dereference(error);
416   if (pointee_sp && error.Success()) {
417     if (pointee_sp->DumpPrintableRepresentation(
418             stream, ValueObject::eValueObjectRepresentationStyleSummary,
419             lldb::eFormatInvalid,
420             ValueObject::PrintableRepresentationSpecialCases::eDisable,
421             false)) {
422       return true;
423     }
424   }
425 
426   stream.Printf("ptr = 0x%" PRIx64, ptr_sp->GetValueAsUnsigned(0));
427   return true;
428 }
429