1 //===-- Value.cpp -----------------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Core/Value.h"
11 
12 // C Includes
13 // C++ Includes
14 // Other libraries and framework includes
15 // Project includes
16 #include "lldb/Core/DataExtractor.h"
17 #include "lldb/Core/DataBufferHeap.h"
18 #include "lldb/Core/Module.h"
19 #include "lldb/Core/Stream.h"
20 #include "lldb/Symbol/ClangASTType.h"
21 #include "lldb/Symbol/ClangASTContext.h"
22 #include "lldb/Symbol/ObjectFile.h"
23 #include "lldb/Symbol/SymbolContext.h"
24 #include "lldb/Symbol/Type.h"
25 #include "lldb/Symbol/Variable.h"
26 #include "lldb/Target/ExecutionContext.h"
27 #include "lldb/Target/Process.h"
28 #include "lldb/Target/Target.h"
29 
30 using namespace lldb;
31 using namespace lldb_private;
32 
33 Value::Value() :
34     m_value (),
35     m_value_type (eValueTypeScalar),
36     m_context (NULL),
37     m_context_type (eContextTypeInvalid),
38     m_data_buffer ()
39 {
40 }
41 
42 Value::Value(const Scalar& scalar) :
43     m_value (scalar),
44     m_value_type (eValueTypeScalar),
45     m_context (NULL),
46     m_context_type (eContextTypeInvalid),
47     m_data_buffer ()
48 {
49 }
50 
51 
52 Value::Value(const uint8_t *bytes, int len) :
53     m_value (),
54     m_value_type (eValueTypeHostAddress),
55     m_context (NULL),
56     m_context_type (eContextTypeInvalid),
57     m_data_buffer ()
58 {
59     m_data_buffer.CopyData(bytes, len);
60     m_value = (uintptr_t)m_data_buffer.GetBytes();
61 }
62 
63 Value::Value(const Value &v) :
64     m_value(v.m_value),
65     m_value_type(v.m_value_type),
66     m_context(v.m_context),
67     m_context_type(v.m_context_type)
68 {
69     if ((uintptr_t)v.m_value.ULongLong(LLDB_INVALID_ADDRESS) == (uintptr_t)v.m_data_buffer.GetBytes())
70     {
71         m_data_buffer.CopyData(v.m_data_buffer.GetBytes(),
72                                v.m_data_buffer.GetByteSize());
73 
74         m_value = (uintptr_t)m_data_buffer.GetBytes();
75     }
76 }
77 
78 Value &
79 Value::operator=(const Value &rhs)
80 {
81     if (this != &rhs)
82     {
83         m_value = rhs.m_value;
84         m_value_type = rhs.m_value_type;
85         m_context = rhs.m_context;
86         m_context_type = rhs.m_context_type;
87         if ((uintptr_t)rhs.m_value.ULongLong(LLDB_INVALID_ADDRESS) == (uintptr_t)rhs.m_data_buffer.GetBytes())
88         {
89             m_data_buffer.CopyData(rhs.m_data_buffer.GetBytes(),
90                                    rhs.m_data_buffer.GetByteSize());
91 
92             m_value = (uintptr_t)m_data_buffer.GetBytes();
93         }
94     }
95     return *this;
96 }
97 
98 void
99 Value::Dump (Stream* strm)
100 {
101     m_value.GetValue (strm, true);
102     strm->Printf(", value_type = %s, context = %p, context_type = %s",
103                 Value::GetValueTypeAsCString(m_value_type),
104                 m_context,
105                 Value::GetContextTypeAsCString(m_context_type));
106 }
107 
108 Value::ValueType
109 Value::GetValueType() const
110 {
111     return m_value_type;
112 }
113 
114 AddressType
115 Value::GetValueAddressType () const
116 {
117     switch (m_value_type)
118     {
119     default:
120     case eValueTypeScalar:
121         break;
122     case eValueTypeLoadAddress: return eAddressTypeLoad;
123     case eValueTypeFileAddress: return eAddressTypeFile;
124     case eValueTypeHostAddress: return eAddressTypeHost;
125     }
126     return eAddressTypeInvalid;
127 }
128 
129 RegisterInfo *
130 Value::GetRegisterInfo()
131 {
132     if (m_context_type == eContextTypeRegisterInfo)
133         return static_cast<RegisterInfo *> (m_context);
134     return NULL;
135 }
136 
137 Type *
138 Value::GetType()
139 {
140     if (m_context_type == eContextTypeLLDBType)
141         return static_cast<Type *> (m_context);
142     return NULL;
143 }
144 
145 void
146 Value::ResizeData(int len)
147 {
148     m_value_type = eValueTypeHostAddress;
149     m_data_buffer.SetByteSize(len);
150     m_value = (uintptr_t)m_data_buffer.GetBytes();
151 }
152 
153 bool
154 Value::ValueOf(ExecutionContext *exe_ctx, clang::ASTContext *ast_context)
155 {
156     switch (m_context_type)
157     {
158     default:
159     case eContextTypeInvalid:
160     case eContextTypeClangType:         // clang::Type *
161     case eContextTypeRegisterInfo:      // RegisterInfo *
162     case eContextTypeLLDBType:          // Type *
163         break;
164 
165     case eContextTypeVariable:          // Variable *
166         ResolveValue(exe_ctx, ast_context);
167         return true;
168     }
169     return false;
170 }
171 
172 size_t
173 Value::GetValueByteSize (clang::ASTContext *ast_context, Error *error_ptr)
174 {
175     size_t byte_size = 0;
176 
177     switch (m_context_type)
178     {
179     default:
180     case eContextTypeInvalid:
181         // If we have no context, there is no way to know how much memory to read
182         if (error_ptr)
183             error_ptr->SetErrorString ("Invalid context type, there is no way to know how much memory to read.");
184         break;
185 
186     case eContextTypeClangType:
187         if (ast_context == NULL)
188         {
189             if (error_ptr)
190                 error_ptr->SetErrorString ("Can't determine size of opaque clang type with NULL ASTContext *.");
191         }
192         else
193         {
194             uint64_t bit_width = ClangASTType::GetClangTypeBitWidth (ast_context, m_context);
195             byte_size = (bit_width + 7 ) / 8;
196         }
197         break;
198 
199     case eContextTypeRegisterInfo:     // RegisterInfo *
200         if (GetRegisterInfo())
201             byte_size = GetRegisterInfo()->byte_size;
202         else if (error_ptr)
203                 error_ptr->SetErrorString ("Can't determine byte size with NULL RegisterInfo *.");
204 
205         break;
206 
207     case eContextTypeLLDBType:             // Type *
208         if (GetType())
209             byte_size = GetType()->GetByteSize();
210         else if (error_ptr)
211             error_ptr->SetErrorString ("Can't determine byte size with NULL Type *.");
212         break;
213 
214     case eContextTypeVariable:         // Variable *
215         if (GetVariable())
216         {
217             if (GetVariable()->GetType())
218                 byte_size = GetVariable()->GetType()->GetByteSize();
219             else if (error_ptr)
220                 error_ptr->SetErrorString ("Can't determine byte size with NULL Type *.");
221         }
222         else if (error_ptr)
223             error_ptr->SetErrorString ("Can't determine byte size with NULL Variable *.");
224         break;
225     }
226 
227     if (error_ptr)
228     {
229         if (byte_size == 0)
230         {
231             if (error_ptr->Success())
232                 error_ptr->SetErrorString("Unable to determine byte size.");
233         }
234         else
235         {
236             error_ptr->Clear();
237         }
238     }
239     return byte_size;
240 }
241 
242 clang_type_t
243 Value::GetClangType ()
244 {
245     switch (m_context_type)
246     {
247     default:
248     case eContextTypeInvalid:
249         break;
250 
251     case eContextTypeClangType:
252         return m_context;
253 
254     case eContextTypeRegisterInfo:
255         break;    // TODO: Eventually convert into a clang type?
256 
257     case eContextTypeLLDBType:
258         if (GetType())
259             return GetType()->GetClangForwardType();
260         break;
261 
262     case eContextTypeVariable:
263         if (GetVariable())
264             return GetVariable()->GetType()->GetClangForwardType();
265         break;
266     }
267 
268     return NULL;
269 }
270 
271 lldb::Format
272 Value::GetValueDefaultFormat ()
273 {
274     switch (m_context_type)
275     {
276     default:
277     case eContextTypeInvalid:
278         break;
279 
280     case eContextTypeClangType:
281         return ClangASTType::GetFormat (m_context);
282 
283     case eContextTypeRegisterInfo:
284         if (GetRegisterInfo())
285             return GetRegisterInfo()->format;
286         break;
287 
288     case eContextTypeLLDBType:
289         if (GetType())
290             return GetType()->GetFormat();
291         break;
292 
293     case eContextTypeVariable:
294         if (GetVariable())
295             return GetVariable()->GetType()->GetFormat();
296         break;
297 
298     }
299 
300     // Return a good default in case we can't figure anything out
301     return eFormatHex;
302 }
303 
304 bool
305 Value::GetData (DataExtractor &data)
306 {
307     switch (m_value_type)
308     {
309     default:
310         break;
311 
312     case eValueTypeScalar:
313         if (m_value.GetData (data))
314             return true;
315         break;
316 
317     case eValueTypeLoadAddress:
318     case eValueTypeFileAddress:
319     case eValueTypeHostAddress:
320         if (m_data_buffer.GetByteSize())
321         {
322             data.SetData(m_data_buffer.GetBytes(), m_data_buffer.GetByteSize(), data.GetByteOrder());
323             return true;
324         }
325         break;
326     }
327 
328     return false;
329 
330 }
331 
332 Error
333 Value::GetValueAsData (ExecutionContext *exe_ctx,
334                        clang::ASTContext *ast_context,
335                        DataExtractor &data,
336                        uint32_t data_offset,
337                        Module *module)
338 {
339     data.Clear();
340 
341     Error error;
342     lldb::addr_t address = LLDB_INVALID_ADDRESS;
343     AddressType address_type = eAddressTypeFile;
344     Address file_so_addr;
345     switch (m_value_type)
346     {
347     default:
348         error.SetErrorStringWithFormat("invalid value type %i", m_value_type);
349         break;
350 
351     case eValueTypeScalar:
352         data.SetByteOrder (lldb::endian::InlHostByteOrder());
353         if (m_context_type == eContextTypeClangType && ast_context)
354         {
355             uint32_t ptr_bit_width = ClangASTType::GetClangTypeBitWidth (ast_context,
356                                                                      ClangASTContext::GetVoidPtrType(ast_context, false));
357             uint32_t ptr_byte_size = (ptr_bit_width + 7) / 8;
358             data.SetAddressByteSize (ptr_byte_size);
359         }
360         else
361             data.SetAddressByteSize(sizeof(void *));
362         if (m_value.GetData (data))
363             return error;   // Success;
364         error.SetErrorStringWithFormat("extracting data from value failed");
365         break;
366 
367     case eValueTypeLoadAddress:
368         if (exe_ctx == NULL)
369         {
370             error.SetErrorString ("can't read load address (no execution context)");
371         }
372         else
373         {
374             Process *process = exe_ctx->GetProcessPtr();
375             if (process == NULL)
376             {
377                 error.SetErrorString ("can't read load address (invalid process)");
378             }
379             else
380             {
381                 address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
382                 address_type = eAddressTypeLoad;
383                 data.SetByteOrder(process->GetTarget().GetArchitecture().GetByteOrder());
384                 data.SetAddressByteSize(process->GetTarget().GetArchitecture().GetAddressByteSize());
385             }
386         }
387         break;
388 
389     case eValueTypeFileAddress:
390         if (exe_ctx == NULL)
391         {
392             error.SetErrorString ("can't read file address (no execution context)");
393         }
394         else if (exe_ctx->GetTargetPtr() == NULL)
395         {
396             error.SetErrorString ("can't read file address (invalid target)");
397         }
398         else
399         {
400             address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
401             if (address == LLDB_INVALID_ADDRESS)
402             {
403                 error.SetErrorString ("invalid file address");
404             }
405             else
406             {
407                 if (module == NULL)
408                 {
409                     // The only thing we can currently lock down to a module so that
410                     // we can resolve a file address, is a variable.
411                     Variable *variable = GetVariable();
412                     if (variable)
413                     {
414                         SymbolContext var_sc;
415                         variable->CalculateSymbolContext(&var_sc);
416                         module = var_sc.module_sp.get();
417                     }
418                 }
419 
420                 if (module)
421                 {
422                     bool resolved = false;
423                     ObjectFile *objfile = module->GetObjectFile();
424                     if (objfile)
425                     {
426                         Address so_addr(address, objfile->GetSectionList());
427                         addr_t load_address = so_addr.GetLoadAddress (exe_ctx->GetTargetPtr());
428                         if (load_address != LLDB_INVALID_ADDRESS)
429                         {
430                             resolved = true;
431                             address = load_address;
432                             address_type = eAddressTypeLoad;
433                             data.SetByteOrder(exe_ctx->GetTargetRef().GetArchitecture().GetByteOrder());
434                             data.SetAddressByteSize(exe_ctx->GetTargetRef().GetArchitecture().GetAddressByteSize());
435                         }
436                         else
437                         {
438                             if (so_addr.IsSectionOffset())
439                             {
440                                 resolved = true;
441                                 file_so_addr = so_addr;
442                                 data.SetByteOrder(objfile->GetByteOrder());
443                                 data.SetAddressByteSize(objfile->GetAddressByteSize());
444                             }
445                         }
446                     }
447                     if (!resolved)
448                     {
449                         Variable *variable = GetVariable();
450 
451                         if (module)
452                         {
453                             if (variable)
454                                 error.SetErrorStringWithFormat ("unable to resolve the module for file address 0x%llx for variable '%s' in %s%s%s",
455                                                                 address,
456                                                                 variable->GetName().AsCString(""),
457                                                                 module->GetFileSpec().GetDirectory().GetCString(),
458                                                                 module->GetFileSpec().GetDirectory() ? "/" : "",
459                                                                 module->GetFileSpec().GetFilename().GetCString());
460                             else
461                                 error.SetErrorStringWithFormat ("unable to resolve the module for file address 0x%llx in %s%s%s",
462                                                                 address,
463                                                                 module->GetFileSpec().GetDirectory().GetCString(),
464                                                                 module->GetFileSpec().GetDirectory() ? "/" : "",
465                                                                 module->GetFileSpec().GetFilename().GetCString());
466                         }
467                         else
468                         {
469                             if (variable)
470                                 error.SetErrorStringWithFormat ("unable to resolve the module for file address 0x%llx for variable '%s'",
471                                                                 address,
472                                                                 variable->GetName().AsCString(""));
473                             else
474                                 error.SetErrorStringWithFormat ("unable to resolve the module for file address 0x%llx", address);
475                         }
476                     }
477                 }
478                 else
479                 {
480                     // Can't convert a file address to anything valid without more
481                     // context (which Module it came from)
482                     error.SetErrorString ("can't read memory from file address without more context");
483                 }
484             }
485         }
486         break;
487 
488     case eValueTypeHostAddress:
489         address = m_value.ULongLong(LLDB_INVALID_ADDRESS);
490         data.SetByteOrder(lldb::endian::InlHostByteOrder());
491         data.SetAddressByteSize(sizeof(void *));
492         address_type = eAddressTypeHost;
493         break;
494     }
495 
496     // Bail if we encountered any errors
497     if (error.Fail())
498         return error;
499 
500     if (address == LLDB_INVALID_ADDRESS)
501     {
502         error.SetErrorStringWithFormat ("invalid %s address", address_type == eAddressTypeHost ? "host" : "load");
503         return error;
504     }
505 
506     // If we got here, we need to read the value from memory
507     uint32_t byte_size = GetValueByteSize (ast_context, &error);
508 
509     // Bail if we encountered any errors getting the byte size
510     if (error.Fail())
511         return error;
512 
513     // Make sure we have enough room within "data", and if we don't make
514     // something large enough that does
515     if (!data.ValidOffsetForDataOfSize (data_offset, byte_size))
516     {
517         DataBufferSP data_sp(new DataBufferHeap (data_offset + byte_size, '\0'));
518         data.SetData(data_sp);
519     }
520 
521     uint8_t* dst = const_cast<uint8_t*>(data.PeekData (data_offset, byte_size));
522     if (dst != NULL)
523     {
524         if (address_type == eAddressTypeHost)
525         {
526             // The address is an address in this process, so just copy it
527             memcpy (dst, (uint8_t*)NULL + address, byte_size);
528         }
529         else if ((address_type == eAddressTypeLoad) || (address_type == eAddressTypeFile))
530         {
531             if (file_so_addr.IsValid())
532             {
533                 // We have a file address that we were able to translate into a
534                 // section offset address so we might be able to read this from
535                 // the object files if we don't have a live process. Lets always
536                 // try and read from the process if we have one though since we
537                 // want to read the actual value by setting "prefer_file_cache"
538                 // to false.
539                 const bool prefer_file_cache = false;
540                 if (exe_ctx->GetTargetRef().ReadMemory(file_so_addr, prefer_file_cache, dst, byte_size, error) != byte_size)
541                 {
542                     error.SetErrorStringWithFormat("read memory from 0x%llx failed", (uint64_t)address);
543                 }
544             }
545             else
546             {
547                 // The execution context might have a NULL process, but it
548                 // might have a valid process in the exe_ctx->target, so use
549                 // the ExecutionContext::GetProcess accessor to ensure we
550                 // get the process if there is one.
551                 Process *process = exe_ctx->GetProcessPtr();
552 
553                 if (process)
554                 {
555                     const size_t bytes_read = process->ReadMemory(address, dst, byte_size, error);
556                     if (bytes_read != byte_size)
557                         error.SetErrorStringWithFormat("read memory from 0x%llx failed (%u of %u bytes read)",
558                                                        (uint64_t)address,
559                                                        (uint32_t)bytes_read,
560                                                        (uint32_t)byte_size);
561                 }
562                 else
563                 {
564                     error.SetErrorStringWithFormat("read memory from 0x%llx failed (invalid process)", (uint64_t)address);
565                 }
566             }
567         }
568         else
569         {
570             error.SetErrorStringWithFormat ("unsupported AddressType value (%i)", address_type);
571         }
572     }
573     else
574     {
575         error.SetErrorStringWithFormat ("out of memory");
576     }
577 
578     return error;
579 }
580 
581 Scalar &
582 Value::ResolveValue(ExecutionContext *exe_ctx, clang::ASTContext *ast_context)
583 {
584     void *opaque_clang_qual_type = GetClangType();
585     if (opaque_clang_qual_type)
586     {
587         switch (m_value_type)
588         {
589         case eValueTypeScalar:               // raw scalar value
590             break;
591 
592         default:
593         case eValueTypeFileAddress:
594             m_value.Clear();
595             break;
596 
597         case eValueTypeLoadAddress:          // load address value
598         case eValueTypeHostAddress:          // host address value (for memory in the process that is using liblldb)
599             {
600                 AddressType address_type = m_value_type == eValueTypeLoadAddress ? eAddressTypeLoad : eAddressTypeHost;
601                 lldb::addr_t addr = m_value.ULongLong(LLDB_INVALID_ADDRESS);
602                 DataExtractor data;
603                 if (ClangASTType::ReadFromMemory (ast_context, opaque_clang_qual_type, exe_ctx, addr, address_type, data))
604                 {
605                     Scalar scalar;
606                     if (ClangASTType::GetValueAsScalar (ast_context, opaque_clang_qual_type, data, 0, data.GetByteSize(), scalar))
607                     {
608                         m_value = scalar;
609                         m_value_type = eValueTypeScalar;
610                     }
611                     else
612                     {
613                         if ((uintptr_t)addr != (uintptr_t)m_data_buffer.GetBytes())
614                         {
615                             m_value.Clear();
616                             m_value_type = eValueTypeScalar;
617                         }
618                     }
619                 }
620                 else
621                 {
622                     if ((uintptr_t)addr != (uintptr_t)m_data_buffer.GetBytes())
623                     {
624                         m_value.Clear();
625                         m_value_type = eValueTypeScalar;
626                     }
627                 }
628             }
629             break;
630         }
631     }
632     return m_value;
633 }
634 
635 Variable *
636 Value::GetVariable()
637 {
638     if (m_context_type == eContextTypeVariable)
639         return static_cast<Variable *> (m_context);
640     return NULL;
641 }
642 
643 const char *
644 Value::GetValueTypeAsCString (ValueType value_type)
645 {
646     switch (value_type)
647     {
648     case eValueTypeScalar:      return "scalar";
649     case eValueTypeFileAddress: return "file address";
650     case eValueTypeLoadAddress: return "load address";
651     case eValueTypeHostAddress: return "host address";
652     };
653     return "???";
654 }
655 
656 const char *
657 Value::GetContextTypeAsCString (ContextType context_type)
658 {
659     switch (context_type)
660     {
661     case eContextTypeInvalid:       return "invalid";
662     case eContextTypeClangType:     return "clang::Type *";
663     case eContextTypeRegisterInfo:  return "RegisterInfo *";
664     case eContextTypeLLDBType:      return "Type *";
665     case eContextTypeVariable:      return "Variable *";
666     };
667     return "???";
668 }
669 
670 ValueList::ValueList (const ValueList &rhs)
671 {
672     m_values = rhs.m_values;
673 }
674 
675 const ValueList &
676 ValueList::operator= (const ValueList &rhs)
677 {
678     m_values = rhs.m_values;
679     return *this;
680 }
681 
682 void
683 ValueList::PushValue (const Value &value)
684 {
685     m_values.push_back (value);
686 }
687 
688 size_t
689 ValueList::GetSize()
690 {
691     return m_values.size();
692 }
693 
694 Value *
695 ValueList::GetValueAtIndex (size_t idx)
696 {
697     if (idx < GetSize())
698     {
699         return &(m_values[idx]);
700     }
701     else
702         return NULL;
703 }
704 
705 void
706 ValueList::Clear ()
707 {
708     m_values.clear();
709 }
710