ValueObjectVariable.cpp revision b66cd074ec097b5b0a6f2ce292f5072aa1217ca6 
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
33using namespace lldb_private;
34
35ValueObjectVariable::ValueObjectVariable (const lldb::VariableSP &var_sp) :
36    ValueObject(),
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
44ValueObjectVariable::~ValueObjectVariable()
45{
46}
47
48void *
49ValueObjectVariable::GetOpaqueClangQualType ()
50{
51    Type *var_type = m_variable_sp->GetType();
52    if (var_type)
53        return var_type->GetOpaqueClangQualType();
54    return NULL;
55}
56
57ConstString
58ValueObjectVariable::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
67uint32_t
68ValueObjectVariable::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
76clang::ASTContext *
77ValueObjectVariable::GetClangAST ()
78{
79    return m_variable_sp->GetType()->GetClangAST();
80}
81
82size_t
83ValueObjectVariable::GetByteSize()
84{
85    return m_variable_sp->GetType()->GetByteSize();
86}
87
88lldb::ValueType
89ValueObjectVariable::GetValueType() const
90{
91    if (m_variable_sp)
92        return m_variable_sp->GetScope();
93    return lldb::eValueTypeInvalid;
94}
95
96void
97ValueObjectVariable::UpdateValue (ExecutionContextScope *exe_scope)
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 (exe_scope);
106
107    if (exe_ctx.process)
108    {
109        m_data.SetByteOrder(exe_ctx.process->GetByteOrder());
110        m_data.SetAddressByteSize(exe_ctx.process->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(), loclist_base_load_addr, NULL, m_value, &m_error))
122    {
123        m_value.SetContext(Value::eContextTypeDCVariable, 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 (GetOpaqueClangQualType()))
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::eContextTypeDCVariable, variable);
188                m_error = value.GetValueAsData(&exe_ctx, GetClangAST(), m_data, 0);
189            }
190            break;
191        }
192
193        SetValueIsValid (m_error.Success());
194    }
195}
196
197
198
199bool
200ValueObjectVariable::IsInScope (StackFrame *frame)
201{
202    return m_variable_sp->IsInScope (frame);
203}
204
205