ValueObjectVariable.cpp revision 49ce8969d3154e1560106cfe530444c09410f217 
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/Function.h"
22#include "lldb/Symbol/ObjectFile.h"
23#include "lldb/Symbol/SymbolContext.h"
24#include "lldb/Symbol/SymbolContextScope.h"
25#include "lldb/Symbol/Type.h"
26#include "lldb/Symbol/Variable.h"
27
28#include "lldb/Target/ExecutionContext.h"
29#include "lldb/Target/Process.h"
30#include "lldb/Target/RegisterContext.h"
31#include "lldb/Target/Target.h"
32#include "lldb/Target/Thread.h"
33
34
35using namespace lldb_private;
36
37lldb::ValueObjectSP
38ValueObjectVariable::Create (ExecutionContextScope *exe_scope, const lldb::VariableSP &var_sp)
39{
40    return (new ValueObjectVariable (exe_scope, var_sp))->GetSP();
41}
42
43ValueObjectVariable::ValueObjectVariable (ExecutionContextScope *exe_scope, const lldb::VariableSP &var_sp) :
44    ValueObject(exe_scope),
45    m_variable_sp(var_sp)
46{
47    // Do not attempt to construct one of these objects with no variable!
48    assert (m_variable_sp.get() != NULL);
49    m_name = var_sp->GetName();
50}
51
52ValueObjectVariable::~ValueObjectVariable()
53{
54}
55
56lldb::clang_type_t
57ValueObjectVariable::GetClangTypeImpl ()
58{
59    Type *var_type = m_variable_sp->GetType();
60    if (var_type)
61        return var_type->GetClangForwardType();
62    return NULL;
63}
64
65ConstString
66ValueObjectVariable::GetTypeName()
67{
68    Type * var_type = m_variable_sp->GetType();
69    if (var_type)
70        return var_type->GetName();
71    return ConstString();
72}
73
74ConstString
75ValueObjectVariable::GetQualifiedTypeName()
76{
77    Type * var_type = m_variable_sp->GetType();
78    if (var_type)
79        return var_type->GetQualifiedName();
80    return ConstString();
81}
82
83uint32_t
84ValueObjectVariable::CalculateNumChildren()
85{
86    ClangASTType type(GetClangAST(),
87                      GetClangType());
88
89    if (!type.IsValid())
90        return 0;
91
92    const bool omit_empty_base_classes = true;
93    return ClangASTContext::GetNumChildren(type.GetASTContext(), type.GetOpaqueQualType(), omit_empty_base_classes);
94}
95
96clang::ASTContext *
97ValueObjectVariable::GetClangASTImpl ()
98{
99    Type *var_type = m_variable_sp->GetType();
100    if (var_type)
101        return var_type->GetClangAST();
102    return 0;
103}
104
105size_t
106ValueObjectVariable::GetByteSize()
107{
108    ClangASTType type(GetClangAST(),
109                      GetClangType());
110
111    if (!type.IsValid())
112        return 0;
113
114    return (ClangASTType::GetClangTypeBitWidth(type.GetASTContext(), type.GetOpaqueQualType()) + 7) / 8;
115}
116
117lldb::ValueType
118ValueObjectVariable::GetValueType() const
119{
120    if (m_variable_sp)
121        return m_variable_sp->GetScope();
122    return lldb::eValueTypeInvalid;
123}
124
125bool
126ValueObjectVariable::UpdateValue ()
127{
128    SetValueIsValid (false);
129    m_error.Clear();
130
131    Variable *variable = m_variable_sp.get();
132    DWARFExpression &expr = variable->LocationExpression();
133
134    if (variable->GetLocationIsConstantValueData())
135    {
136        // expr doesn't contain DWARF bytes, it contains the constant variable
137        // value bytes themselves...
138        if (expr.GetExpressionData(m_data))
139            m_value.SetContext(Value::eContextTypeVariable, variable);
140        else
141            m_error.SetErrorString ("empty constant data");
142    }
143    else
144    {
145        lldb::addr_t loclist_base_load_addr = LLDB_INVALID_ADDRESS;
146        ExecutionContext exe_ctx (GetExecutionContextRef());
147
148        Target *target = exe_ctx.GetTargetPtr();
149        if (target)
150        {
151            m_data.SetByteOrder(target->GetArchitecture().GetByteOrder());
152            m_data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
153        }
154
155        if (expr.IsLocationList())
156        {
157            SymbolContext sc;
158            variable->CalculateSymbolContext (&sc);
159            if (sc.function)
160                loclist_base_load_addr = sc.function->GetAddressRange().GetBaseAddress().GetLoadAddress (target);
161        }
162        Value old_value(m_value);
163        if (expr.Evaluate (&exe_ctx, GetClangAST(), NULL, NULL, NULL, loclist_base_load_addr, NULL, m_value, &m_error))
164        {
165            m_value.SetContext(Value::eContextTypeVariable, variable);
166
167            Value::ValueType value_type = m_value.GetValueType();
168
169            switch (value_type)
170            {
171                case Value::eValueTypeFileAddress:
172                    SetAddressTypeOfChildren(eAddressTypeFile);
173                    break;
174                case Value::eValueTypeHostAddress:
175                    SetAddressTypeOfChildren(eAddressTypeHost);
176                    break;
177                case Value::eValueTypeLoadAddress:
178                case Value::eValueTypeScalar:
179                    SetAddressTypeOfChildren(eAddressTypeLoad);
180                    break;
181            }
182
183            switch (value_type)
184            {
185            default:
186                assert(!"Unhandled expression result value kind...");
187                break;
188
189            case Value::eValueTypeScalar:
190                // The variable value is in the Scalar value inside the m_value.
191                // We can point our m_data right to it.
192                m_error = m_value.GetValueAsData (&exe_ctx, GetClangAST(), m_data, 0, GetModule().get());
193                break;
194
195            case Value::eValueTypeFileAddress:
196            case Value::eValueTypeLoadAddress:
197            case Value::eValueTypeHostAddress:
198                // The DWARF expression result was an address in the inferior
199                // process. If this variable is an aggregate type, we just need
200                // the address as the main value as all child variable objects
201                // will rely upon this location and add an offset and then read
202                // their own values as needed. If this variable is a simple
203                // type, we read all data for it into m_data.
204                // Make sure this type has a value before we try and read it
205
206                // If we have a file address, convert it to a load address if we can.
207                Process *process = exe_ctx.GetProcessPtr();
208                if (value_type == Value::eValueTypeFileAddress && process && process->IsAlive())
209                {
210                    lldb::addr_t file_addr = m_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
211                    if (file_addr != LLDB_INVALID_ADDRESS)
212                    {
213                        SymbolContext var_sc;
214                        variable->CalculateSymbolContext(&var_sc);
215                        if (var_sc.module_sp)
216                        {
217                            ObjectFile *objfile = var_sc.module_sp->GetObjectFile();
218                            if (objfile)
219                            {
220                                Address so_addr(file_addr, objfile->GetSectionList());
221                                lldb::addr_t load_addr = so_addr.GetLoadAddress (target);
222                                if (load_addr != LLDB_INVALID_ADDRESS)
223                                {
224                                    m_value.SetValueType(Value::eValueTypeLoadAddress);
225                                    m_value.GetScalar() = load_addr;
226                                }
227                            }
228                        }
229                    }
230                }
231
232                if (ClangASTContext::IsAggregateType (GetClangType()))
233                {
234                    // this value object represents an aggregate type whose
235                    // children have values, but this object does not. So we
236                    // say we are changed if our location has changed.
237                    SetValueDidChange (value_type != old_value.GetValueType() || m_value.GetScalar() != old_value.GetScalar());
238                }
239                else
240                {
241                    // Copy the Value and set the context to use our Variable
242                    // so it can extract read its value into m_data appropriately
243                    Value value(m_value);
244                    value.SetContext(Value::eContextTypeVariable, variable);
245                    m_error = value.GetValueAsData(&exe_ctx, GetClangAST(), m_data, 0, GetModule().get());
246                }
247                break;
248            }
249
250            SetValueIsValid (m_error.Success());
251        }
252    }
253    return m_error.Success();
254}
255
256
257
258bool
259ValueObjectVariable::IsInScope ()
260{
261    const ExecutionContextRef &exe_ctx_ref = GetExecutionContextRef();
262    if (exe_ctx_ref.HasFrameRef())
263    {
264        ExecutionContext exe_ctx (exe_ctx_ref);
265        StackFrame *frame = exe_ctx.GetFramePtr();
266        if (frame)
267        {
268            return m_variable_sp->IsInScope (frame);
269        }
270        else
271        {
272            // This ValueObject had a frame at one time, but now we
273            // can't locate it, so return false since we probably aren't
274            // in scope.
275            return false;
276        }
277    }
278    // We have a variable that wasn't tied to a frame, which
279    // means it is a global and is always in scope.
280    return true;
281
282}
283
284lldb::ModuleSP
285ValueObjectVariable::GetModule()
286{
287    if (m_variable_sp)
288    {
289        SymbolContextScope *sc_scope = m_variable_sp->GetSymbolContextScope();
290        if (sc_scope)
291        {
292            return sc_scope->CalculateSymbolContextModule();
293        }
294    }
295    return lldb::ModuleSP();
296}
297
298SymbolContextScope *
299ValueObjectVariable::GetSymbolContextScope()
300{
301    if (m_variable_sp)
302        return m_variable_sp->GetSymbolContextScope();
303    return NULL;
304}
305
306bool
307ValueObjectVariable::GetDeclaration (Declaration &decl)
308{
309    if (m_variable_sp)
310    {
311        decl = m_variable_sp->GetDeclaration();
312        return true;
313    }
314    return false;
315}
316