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