1 //===-- ValueObjectVariable.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 
11 #include "lldb/Core/ValueObjectVariable.h"
12 
13 // C Includes
14 // C++ Includes
15 // Other libraries and framework includes
16 // Project includes
17 #include "lldb/Core/Module.h"
18 #include "lldb/Core/ValueObjectList.h"
19 #include "lldb/Core/Value.h"
20 
21 #include "lldb/Symbol/ObjectFile.h"
22 #include "lldb/Symbol/SymbolContext.h"
23 #include "lldb/Symbol/Type.h"
24 #include "lldb/Symbol/Variable.h"
25 
26 #include "lldb/Target/ExecutionContext.h"
27 #include "lldb/Target/Process.h"
28 #include "lldb/Target/RegisterContext.h"
29 #include "lldb/Target/Target.h"
30 #include "lldb/Target/Thread.h"
31 
32 
33 using namespace lldb_private;
34 
35 lldb::ValueObjectSP
36 ValueObjectVariable::Create (ExecutionContextScope *exe_scope, const lldb::VariableSP &var_sp)
37 {
38     return (new ValueObjectVariable (exe_scope, var_sp))->GetSP();
39 }
40 
41 ValueObjectVariable::ValueObjectVariable (ExecutionContextScope *exe_scope, const lldb::VariableSP &var_sp) :
42     ValueObject(exe_scope),
43     m_variable_sp(var_sp)
44 {
45     // Do not attempt to construct one of these objects with no variable!
46     assert (m_variable_sp.get() != NULL);
47     m_name = var_sp->GetName();
48 }
49 
50 ValueObjectVariable::~ValueObjectVariable()
51 {
52 }
53 
54 lldb::clang_type_t
55 ValueObjectVariable::GetClangType ()
56 {
57     Type *var_type = m_variable_sp->GetType();
58     if (var_type)
59         return var_type->GetClangForwardType();
60     return NULL;
61 }
62 
63 ConstString
64 ValueObjectVariable::GetTypeName()
65 {
66     Type * var_type = m_variable_sp->GetType();
67     if (var_type)
68         return var_type->GetName();
69     ConstString empty_type_name;
70     return empty_type_name;
71 }
72 
73 uint32_t
74 ValueObjectVariable::CalculateNumChildren()
75 {
76     Type *var_type = m_variable_sp->GetType();
77     if (var_type)
78         return var_type->GetNumChildren(true);
79     return 0;
80 }
81 
82 clang::ASTContext *
83 ValueObjectVariable::GetClangAST ()
84 {
85     return m_variable_sp->GetType()->GetClangAST();
86 }
87 
88 size_t
89 ValueObjectVariable::GetByteSize()
90 {
91     Type *type = m_variable_sp->GetType();
92     if (type)
93         return type->GetByteSize();
94     return 0;
95 }
96 
97 lldb::ValueType
98 ValueObjectVariable::GetValueType() const
99 {
100     if (m_variable_sp)
101         return m_variable_sp->GetScope();
102     return lldb::eValueTypeInvalid;
103 }
104 
105 bool
106 ValueObjectVariable::UpdateValue ()
107 {
108     SetValueIsValid (false);
109     m_error.Clear();
110 
111     Variable *variable = m_variable_sp.get();
112     DWARFExpression &expr = variable->LocationExpression();
113 
114     if (variable->GetLocationIsConstantValueData())
115     {
116         // expr doesn't contain DWARF bytes, it contains the constant variable
117         // value bytes themselves...
118         if (expr.GetExpressionData(m_data))
119             m_value.SetContext(Value::eContextTypeVariable, variable);
120         else
121             m_error.SetErrorString ("empty constant data");
122     }
123     else
124     {
125         lldb::addr_t loclist_base_load_addr = LLDB_INVALID_ADDRESS;
126         ExecutionContext exe_ctx (GetExecutionContextScope());
127 
128         if (exe_ctx.target)
129         {
130             m_data.SetByteOrder(exe_ctx.target->GetArchitecture().GetByteOrder());
131             m_data.SetAddressByteSize(exe_ctx.target->GetArchitecture().GetAddressByteSize());
132         }
133 
134         if (expr.IsLocationList())
135         {
136             SymbolContext sc;
137             variable->CalculateSymbolContext (&sc);
138             if (sc.function)
139                 loclist_base_load_addr = sc.function->GetAddressRange().GetBaseAddress().GetLoadAddress (exe_ctx.target);
140         }
141         Value old_value(m_value);
142         if (expr.Evaluate (&exe_ctx, GetClangAST(), NULL, NULL, NULL, loclist_base_load_addr, NULL, m_value, &m_error))
143         {
144             m_value.SetContext(Value::eContextTypeVariable, variable);
145 
146             Value::ValueType value_type = m_value.GetValueType();
147 
148             switch (value_type)
149             {
150             default:
151                 assert(!"Unhandled expression result value kind...");
152                 break;
153 
154             case Value::eValueTypeScalar:
155                 // The variable value is in the Scalar value inside the m_value.
156                 // We can point our m_data right to it.
157                 m_error = m_value.GetValueAsData (&exe_ctx, GetClangAST(), m_data, 0);
158                 break;
159 
160             case Value::eValueTypeFileAddress:
161             case Value::eValueTypeLoadAddress:
162             case Value::eValueTypeHostAddress:
163                 // The DWARF expression result was an address in the inferior
164                 // process. If this variable is an aggregate type, we just need
165                 // the address as the main value as all child variable objects
166                 // will rely upon this location and add an offset and then read
167                 // their own values as needed. If this variable is a simple
168                 // type, we read all data for it into m_data.
169                 // Make sure this type has a value before we try and read it
170 
171                 // If we have a file address, convert it to a load address if we can.
172                 if (value_type == Value::eValueTypeFileAddress && exe_ctx.process)
173                 {
174                     lldb::addr_t file_addr = m_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
175                     if (file_addr != LLDB_INVALID_ADDRESS)
176                     {
177                         SymbolContext var_sc;
178                         variable->CalculateSymbolContext(&var_sc);
179                         if (var_sc.module_sp)
180                         {
181                             ObjectFile *objfile = var_sc.module_sp->GetObjectFile();
182                             if (objfile)
183                             {
184                                 Address so_addr(file_addr, objfile->GetSectionList());
185                                 lldb::addr_t load_addr = so_addr.GetLoadAddress (exe_ctx.target);
186                                 if (load_addr != LLDB_INVALID_ADDRESS)
187                                 {
188                                     m_value.SetValueType(Value::eValueTypeLoadAddress);
189                                     m_value.GetScalar() = load_addr;
190                                 }
191                             }
192                         }
193                     }
194                 }
195 
196                 if (ClangASTContext::IsAggregateType (GetClangType()))
197                 {
198                     // this value object represents an aggregate type whose
199                     // children have values, but this object does not. So we
200                     // say we are changed if our location has changed.
201                     SetValueDidChange (value_type != old_value.GetValueType() || m_value.GetScalar() != old_value.GetScalar());
202                 }
203                 else
204                 {
205                     // Copy the Value and set the context to use our Variable
206                     // so it can extract read its value into m_data appropriately
207                     Value value(m_value);
208                     value.SetContext(Value::eContextTypeVariable, variable);
209                     m_error = value.GetValueAsData(&exe_ctx, GetClangAST(), m_data, 0);
210                 }
211                 break;
212             }
213 
214             SetValueIsValid (m_error.Success());
215         }
216     }
217     return m_error.Success();
218 }
219 
220 
221 
222 bool
223 ValueObjectVariable::IsInScope ()
224 {
225     ExecutionContextScope *exe_scope = GetExecutionContextScope();
226     if (!exe_scope)
227         return true;
228 
229     StackFrame *frame = exe_scope->CalculateStackFrame();
230     if (!frame)
231         return true;
232 
233     return m_variable_sp->IsInScope (frame);
234 }
235 
236