ValueObjectVariable.cpp revision 801417e453f8531ac176cd952200587bf15d9ccf 
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/SymbolContextScope.h"
24#include "lldb/Symbol/Type.h"
25#include "lldb/Symbol/Variable.h"
26
27#include "lldb/Target/ExecutionContext.h"
28#include "lldb/Target/Process.h"
29#include "lldb/Target/RegisterContext.h"
30#include "lldb/Target/Target.h"
31#include "lldb/Target/Thread.h"
32
33
34using namespace lldb_private;
35
36lldb::ValueObjectSP
37ValueObjectVariable::Create (ExecutionContextScope *exe_scope, const lldb::VariableSP &var_sp)
38{
39    return (new ValueObjectVariable (exe_scope, var_sp))->GetSP();
40}
41
42ValueObjectVariable::ValueObjectVariable (ExecutionContextScope *exe_scope, const lldb::VariableSP &var_sp) :
43    ValueObject(exe_scope),
44    m_variable_sp(var_sp)
45{
46    // Do not attempt to construct one of these objects with no variable!
47    assert (m_variable_sp.get() != NULL);
48    m_name = var_sp->GetName();
49}
50
51ValueObjectVariable::~ValueObjectVariable()
52{
53}
54
55lldb::clang_type_t
56ValueObjectVariable::GetClangType ()
57{
58    Type *var_type = m_variable_sp->GetType();
59    if (var_type)
60        return var_type->GetClangForwardType();
61    return NULL;
62}
63
64ConstString
65ValueObjectVariable::GetTypeName()
66{
67    Type * var_type = m_variable_sp->GetType();
68    if (var_type)
69        return var_type->GetName();
70    ConstString empty_type_name;
71    return empty_type_name;
72}
73
74uint32_t
75ValueObjectVariable::CalculateNumChildren()
76{
77    Type *var_type = m_variable_sp->GetType();
78    if (var_type)
79        return var_type->GetNumChildren(true);
80    return 0;
81}
82
83clang::ASTContext *
84ValueObjectVariable::GetClangAST ()
85{
86    return m_variable_sp->GetType()->GetClangAST();
87}
88
89size_t
90ValueObjectVariable::GetByteSize()
91{
92    Type *type = m_variable_sp->GetType();
93    if (type)
94        return type->GetByteSize();
95    return 0;
96}
97
98lldb::ValueType
99ValueObjectVariable::GetValueType() const
100{
101    if (m_variable_sp)
102        return m_variable_sp->GetScope();
103    return lldb::eValueTypeInvalid;
104}
105
106bool
107ValueObjectVariable::UpdateValue ()
108{
109    SetValueIsValid (false);
110    m_error.Clear();
111
112    Variable *variable = m_variable_sp.get();
113    DWARFExpression &expr = variable->LocationExpression();
114
115    if (variable->GetLocationIsConstantValueData())
116    {
117        // expr doesn't contain DWARF bytes, it contains the constant variable
118        // value bytes themselves...
119        if (expr.GetExpressionData(m_data))
120            m_value.SetContext(Value::eContextTypeVariable, variable);
121        else
122            m_error.SetErrorString ("empty constant data");
123    }
124    else
125    {
126        lldb::addr_t loclist_base_load_addr = LLDB_INVALID_ADDRESS;
127        ExecutionContext exe_ctx (GetExecutionContextScope());
128
129        if (exe_ctx.target)
130        {
131            m_data.SetByteOrder(exe_ctx.target->GetArchitecture().GetByteOrder());
132            m_data.SetAddressByteSize(exe_ctx.target->GetArchitecture().GetAddressByteSize());
133        }
134
135        if (expr.IsLocationList())
136        {
137            SymbolContext sc;
138            variable->CalculateSymbolContext (&sc);
139            if (sc.function)
140                loclist_base_load_addr = sc.function->GetAddressRange().GetBaseAddress().GetLoadAddress (exe_ctx.target);
141        }
142        Value old_value(m_value);
143        if (expr.Evaluate (&exe_ctx, GetClangAST(), NULL, NULL, NULL, loclist_base_load_addr, NULL, m_value, &m_error))
144        {
145            m_value.SetContext(Value::eContextTypeVariable, variable);
146
147            Value::ValueType value_type = m_value.GetValueType();
148
149            switch (value_type)
150            {
151            default:
152                assert(!"Unhandled expression result value kind...");
153                break;
154
155            case Value::eValueTypeScalar:
156                // The variable value is in the Scalar value inside the m_value.
157                // We can point our m_data right to it.
158                m_error = m_value.GetValueAsData (&exe_ctx, GetClangAST(), m_data, 0, GetModule());
159                break;
160
161            case Value::eValueTypeFileAddress:
162            case Value::eValueTypeLoadAddress:
163            case Value::eValueTypeHostAddress:
164                // The DWARF expression result was an address in the inferior
165                // process. If this variable is an aggregate type, we just need
166                // the address as the main value as all child variable objects
167                // will rely upon this location and add an offset and then read
168                // their own values as needed. If this variable is a simple
169                // type, we read all data for it into m_data.
170                // Make sure this type has a value before we try and read it
171
172                // If we have a file address, convert it to a load address if we can.
173                if (value_type == Value::eValueTypeFileAddress && exe_ctx.process && exe_ctx.process->IsAlive())
174                {
175                    lldb::addr_t file_addr = m_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
176                    if (file_addr != LLDB_INVALID_ADDRESS)
177                    {
178                        SymbolContext var_sc;
179                        variable->CalculateSymbolContext(&var_sc);
180                        if (var_sc.module_sp)
181                        {
182                            ObjectFile *objfile = var_sc.module_sp->GetObjectFile();
183                            if (objfile)
184                            {
185                                Address so_addr(file_addr, objfile->GetSectionList());
186                                lldb::addr_t load_addr = so_addr.GetLoadAddress (exe_ctx.target);
187                                if (load_addr != LLDB_INVALID_ADDRESS)
188                                {
189                                    m_value.SetValueType(Value::eValueTypeLoadAddress);
190                                    m_value.GetScalar() = load_addr;
191                                }
192                            }
193                        }
194                    }
195                }
196
197                if (ClangASTContext::IsAggregateType (GetClangType()))
198                {
199                    // this value object represents an aggregate type whose
200                    // children have values, but this object does not. So we
201                    // say we are changed if our location has changed.
202                    SetValueDidChange (value_type != old_value.GetValueType() || m_value.GetScalar() != old_value.GetScalar());
203                }
204                else
205                {
206                    // Copy the Value and set the context to use our Variable
207                    // so it can extract read its value into m_data appropriately
208                    Value value(m_value);
209                    value.SetContext(Value::eContextTypeVariable, variable);
210                    m_error = value.GetValueAsData(&exe_ctx, GetClangAST(), m_data, 0, GetModule());
211                }
212                break;
213            }
214
215            SetValueIsValid (m_error.Success());
216        }
217    }
218    return m_error.Success();
219}
220
221
222
223bool
224ValueObjectVariable::IsInScope ()
225{
226    ExecutionContextScope *exe_scope = GetExecutionContextScope();
227    if (!exe_scope)
228        return true;
229
230    StackFrame *frame = exe_scope->CalculateStackFrame();
231    if (!frame)
232        return true;
233
234    return m_variable_sp->IsInScope (frame);
235}
236
237Module *
238ValueObjectVariable::GetModule()
239{
240    if (m_variable_sp)
241    {
242        SymbolContextScope *sc_scope = m_variable_sp->GetSymbolContextScope();
243        if (sc_scope)
244        {
245            SymbolContext sc;
246            sc_scope->CalculateSymbolContext (&sc);
247            return sc.module_sp.get();
248        }
249    }
250    return NULL;
251}
252
253
254