ValueObjectVariable.cpp revision 178710cd4307f3d44dc76ebd70fc7daf7ebe17c5 
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
96
97
98void
99ValueObjectVariable::UpdateValue (ExecutionContextScope *exe_scope)
100{
101    SetValueIsValid (false);
102    m_error.Clear();
103
104    Variable *variable = m_variable_sp.get();
105    DWARFExpression &expr = variable->LocationExpression();
106    lldb::addr_t loclist_base_load_addr = LLDB_INVALID_ADDRESS;
107    ExecutionContext exe_ctx (exe_scope);
108    if (expr.IsLocationList())
109    {
110        SymbolContext sc;
111        variable->CalculateSymbolContext (&sc);
112        if (sc.function)
113            loclist_base_load_addr = sc.function->GetAddressRange().GetBaseAddress().GetLoadAddress (exe_ctx.process);
114    }
115    Value old_value(m_value);
116    if (expr.Evaluate (&exe_ctx, GetClangAST(), loclist_base_load_addr, NULL, m_value, &m_error))
117    {
118        m_value.SetContext(Value::eContextTypeDCVariable, variable);
119
120        Value::ValueType value_type = m_value.GetValueType();
121
122        switch (value_type)
123        {
124        default:
125            assert(!"Unhandled expression result value kind...");
126            break;
127
128        case Value::eValueTypeScalar:
129            // The variable value is in the Scalar value inside the m_value.
130            // We can point our m_data right to it.
131            m_error = m_value.GetValueAsData (&exe_ctx, GetClangAST(), m_data, 0);
132            break;
133
134        case Value::eValueTypeFileAddress:
135        case Value::eValueTypeLoadAddress:
136        case Value::eValueTypeHostAddress:
137            // The DWARF expression result was an address in the inferior
138            // process. If this variable is an aggregate type, we just need
139            // the address as the main value as all child variable objects
140            // will rely upon this location and add an offset and then read
141            // their own values as needed. If this variable is a simple
142            // type, we read all data for it into m_data.
143            // Make sure this type has a value before we try and read it
144
145            // If we have a file address, convert it to a load address if we can.
146            if (value_type == Value::eValueTypeFileAddress && exe_ctx.process)
147            {
148                lldb::addr_t file_addr = m_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
149                if (file_addr != LLDB_INVALID_ADDRESS)
150                {
151                    SymbolContext var_sc;
152                    variable->CalculateSymbolContext(&var_sc);
153                    if (var_sc.module_sp)
154                    {
155                        ObjectFile *objfile = var_sc.module_sp->GetObjectFile();
156                        if (objfile)
157                        {
158                            Address so_addr(file_addr, objfile->GetSectionList());
159                            lldb::addr_t load_addr = so_addr.GetLoadAddress (exe_ctx.process);
160                            if (load_addr != LLDB_INVALID_ADDRESS)
161                            {
162                                m_value.SetValueType(Value::eValueTypeLoadAddress);
163                                m_value.GetScalar() = load_addr;
164                            }
165                        }
166                    }
167                }
168            }
169
170            if (ClangASTContext::IsAggregateType (GetOpaqueClangQualType()))
171            {
172                // this value object represents an aggregate type whose
173                // children have values, but this object does not. So we
174                // say we are changed if our location has changed.
175                SetValueDidChange (value_type != old_value.GetValueType() || m_value.GetScalar() != old_value.GetScalar());
176            }
177            else
178            {
179                // Copy the Value and set the context to use our Variable
180                // so it can extract read its value into m_data appropriately
181                Value value(m_value);
182                value.SetContext(Value::eContextTypeDCVariable, variable);
183                m_error = value.GetValueAsData(&exe_ctx, GetClangAST(), m_data, 0);
184            }
185            break;
186        }
187
188        SetValueIsValid (m_error.Success());
189    }
190}
191
192
193
194bool
195ValueObjectVariable::IsInScope (StackFrame *frame)
196{
197    return m_variable_sp->IsInScope (frame);
198}
199
200