ValueObjectVariable.cpp revision 0468bb2077ab25a289514dc474d6b5a7c537202f 
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/RegisterValue.h"
19#include "lldb/Core/ValueObjectList.h"
20#include "lldb/Core/Value.h"
21
22#include "lldb/Symbol/Function.h"
23#include "lldb/Symbol/ObjectFile.h"
24#include "lldb/Symbol/SymbolContext.h"
25#include "lldb/Symbol/SymbolContextScope.h"
26#include "lldb/Symbol/Type.h"
27#include "lldb/Symbol/Variable.h"
28
29#include "lldb/Target/ExecutionContext.h"
30#include "lldb/Target/Process.h"
31#include "lldb/Target/RegisterContext.h"
32#include "lldb/Target/Target.h"
33#include "lldb/Target/Thread.h"
34
35
36using namespace lldb_private;
37
38lldb::ValueObjectSP
39ValueObjectVariable::Create (ExecutionContextScope *exe_scope, const lldb::VariableSP &var_sp)
40{
41    return (new ValueObjectVariable (exe_scope, var_sp))->GetSP();
42}
43
44ValueObjectVariable::ValueObjectVariable (ExecutionContextScope *exe_scope, const lldb::VariableSP &var_sp) :
45    ValueObject(exe_scope),
46    m_variable_sp(var_sp)
47{
48    // Do not attempt to construct one of these objects with no variable!
49    assert (m_variable_sp.get() != NULL);
50    m_name = var_sp->GetName();
51}
52
53ValueObjectVariable::~ValueObjectVariable()
54{
55}
56
57lldb::clang_type_t
58ValueObjectVariable::GetClangTypeImpl ()
59{
60    Type *var_type = m_variable_sp->GetType();
61    if (var_type)
62        return var_type->GetClangForwardType();
63    return NULL;
64}
65
66ConstString
67ValueObjectVariable::GetTypeName()
68{
69    Type * var_type = m_variable_sp->GetType();
70    if (var_type)
71        return var_type->GetName();
72    return ConstString();
73}
74
75ConstString
76ValueObjectVariable::GetQualifiedTypeName()
77{
78    Type * var_type = m_variable_sp->GetType();
79    if (var_type)
80        return var_type->GetQualifiedName();
81    return ConstString();
82}
83
84size_t
85ValueObjectVariable::CalculateNumChildren()
86{
87    ClangASTType type(GetClangAST(),
88                      GetClangType());
89
90    if (!type.IsValid())
91        return 0;
92
93    const bool omit_empty_base_classes = true;
94    return ClangASTContext::GetNumChildren(type.GetASTContext(), type.GetOpaqueQualType(), omit_empty_base_classes);
95}
96
97clang::ASTContext *
98ValueObjectVariable::GetClangASTImpl ()
99{
100    Type *var_type = m_variable_sp->GetType();
101    if (var_type)
102        return var_type->GetClangAST();
103    return 0;
104}
105
106uint64_t
107ValueObjectVariable::GetByteSize()
108{
109    ClangASTType type(GetClangAST(), GetClangType());
110
111    if (!type.IsValid())
112        return 0;
113
114    return type.GetClangTypeByteSize();
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        // constant bytes can't be edited - sorry
143        m_resolved_value.SetContext(Value::eContextTypeInvalid, NULL);
144    }
145    else
146    {
147        lldb::addr_t loclist_base_load_addr = LLDB_INVALID_ADDRESS;
148        ExecutionContext exe_ctx (GetExecutionContextRef());
149
150        Target *target = exe_ctx.GetTargetPtr();
151        if (target)
152        {
153            m_data.SetByteOrder(target->GetArchitecture().GetByteOrder());
154            m_data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
155        }
156
157        if (expr.IsLocationList())
158        {
159            SymbolContext sc;
160            variable->CalculateSymbolContext (&sc);
161            if (sc.function)
162                loclist_base_load_addr = sc.function->GetAddressRange().GetBaseAddress().GetLoadAddress (target);
163        }
164        Value old_value(m_value);
165        if (expr.Evaluate (&exe_ctx, GetClangAST(), NULL, NULL, NULL, loclist_base_load_addr, NULL, m_value, &m_error))
166        {
167            m_resolved_value = m_value;
168            m_value.SetContext(Value::eContextTypeVariable, variable);
169
170            Value::ValueType value_type = m_value.GetValueType();
171
172            switch (value_type)
173            {
174                case Value::eValueTypeFileAddress:
175                    SetAddressTypeOfChildren(eAddressTypeFile);
176                    break;
177                case Value::eValueTypeHostAddress:
178                    SetAddressTypeOfChildren(eAddressTypeHost);
179                    break;
180                case Value::eValueTypeLoadAddress:
181                case Value::eValueTypeScalar:
182                case Value::eValueTypeVector:
183                    SetAddressTypeOfChildren(eAddressTypeLoad);
184                    break;
185            }
186
187            switch (value_type)
188            {
189            default:
190                m_error.SetErrorStringWithFormat("Variable %s has an expression result value %d which is currently unhandled",variable->GetName().GetCString(),value_type);
191                break;
192
193            case Value::eValueTypeVector:
194                    // fall through
195            case Value::eValueTypeScalar:
196                // The variable value is in the Scalar value inside the m_value.
197                // We can point our m_data right to it.
198                m_error = m_value.GetValueAsData (&exe_ctx, GetClangAST(), m_data, 0, GetModule().get());
199                break;
200
201            case Value::eValueTypeFileAddress:
202            case Value::eValueTypeLoadAddress:
203            case Value::eValueTypeHostAddress:
204                // The DWARF expression result was an address in the inferior
205                // process. If this variable is an aggregate type, we just need
206                // the address as the main value as all child variable objects
207                // will rely upon this location and add an offset and then read
208                // their own values as needed. If this variable is a simple
209                // type, we read all data for it into m_data.
210                // Make sure this type has a value before we try and read it
211
212                // If we have a file address, convert it to a load address if we can.
213                Process *process = exe_ctx.GetProcessPtr();
214                if (value_type == Value::eValueTypeFileAddress && process && process->IsAlive())
215                {
216                    lldb::addr_t file_addr = m_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
217                    if (file_addr != LLDB_INVALID_ADDRESS)
218                    {
219                        SymbolContext var_sc;
220                        variable->CalculateSymbolContext(&var_sc);
221                        if (var_sc.module_sp)
222                        {
223                            ObjectFile *objfile = var_sc.module_sp->GetObjectFile();
224                            if (objfile)
225                            {
226                                Address so_addr(file_addr, objfile->GetSectionList());
227                                lldb::addr_t load_addr = so_addr.GetLoadAddress (target);
228                                if (load_addr != LLDB_INVALID_ADDRESS)
229                                {
230                                    m_value.SetValueType(Value::eValueTypeLoadAddress);
231                                    m_value.GetScalar() = load_addr;
232                                }
233                            }
234                        }
235                    }
236                }
237
238                if (ClangASTContext::IsAggregateType (GetClangType()))
239                {
240                    // this value object represents an aggregate type whose
241                    // children have values, but this object does not. So we
242                    // say we are changed if our location has changed.
243                    SetValueDidChange (value_type != old_value.GetValueType() || m_value.GetScalar() != old_value.GetScalar());
244                }
245                else
246                {
247                    // Copy the Value and set the context to use our Variable
248                    // so it can extract read its value into m_data appropriately
249                    Value value(m_value);
250                    value.SetContext(Value::eContextTypeVariable, variable);
251                    m_error = value.GetValueAsData(&exe_ctx, GetClangAST(), m_data, 0, GetModule().get());
252                }
253                break;
254            }
255
256            SetValueIsValid (m_error.Success());
257        }
258        else
259        {
260            // could not find location, won't allow editing
261            m_resolved_value.SetContext(Value::eContextTypeInvalid, NULL);
262        }
263    }
264    return m_error.Success();
265}
266
267
268
269bool
270ValueObjectVariable::IsInScope ()
271{
272    const ExecutionContextRef &exe_ctx_ref = GetExecutionContextRef();
273    if (exe_ctx_ref.HasFrameRef())
274    {
275        ExecutionContext exe_ctx (exe_ctx_ref);
276        StackFrame *frame = exe_ctx.GetFramePtr();
277        if (frame)
278        {
279            return m_variable_sp->IsInScope (frame);
280        }
281        else
282        {
283            // This ValueObject had a frame at one time, but now we
284            // can't locate it, so return false since we probably aren't
285            // in scope.
286            return false;
287        }
288    }
289    // We have a variable that wasn't tied to a frame, which
290    // means it is a global and is always in scope.
291    return true;
292
293}
294
295lldb::ModuleSP
296ValueObjectVariable::GetModule()
297{
298    if (m_variable_sp)
299    {
300        SymbolContextScope *sc_scope = m_variable_sp->GetSymbolContextScope();
301        if (sc_scope)
302        {
303            return sc_scope->CalculateSymbolContextModule();
304        }
305    }
306    return lldb::ModuleSP();
307}
308
309SymbolContextScope *
310ValueObjectVariable::GetSymbolContextScope()
311{
312    if (m_variable_sp)
313        return m_variable_sp->GetSymbolContextScope();
314    return NULL;
315}
316
317bool
318ValueObjectVariable::GetDeclaration (Declaration &decl)
319{
320    if (m_variable_sp)
321    {
322        decl = m_variable_sp->GetDeclaration();
323        return true;
324    }
325    return false;
326}
327
328const char *
329ValueObjectVariable::GetLocationAsCString ()
330{
331    if (m_resolved_value.GetContextType() == Value::eContextTypeRegisterInfo)
332        return GetLocationAsCStringImpl(m_resolved_value,
333                                        m_data);
334    else
335        return ValueObject::GetLocationAsCString();
336}
337
338bool
339ValueObjectVariable::SetValueFromCString (const char *value_str, Error& error)
340{
341    if (m_resolved_value.GetContextType() == Value::eContextTypeRegisterInfo)
342    {
343        RegisterInfo *reg_info = m_resolved_value.GetRegisterInfo();
344        ExecutionContext exe_ctx(GetExecutionContextRef());
345        RegisterContext *reg_ctx = exe_ctx.GetRegisterContext();
346        RegisterValue reg_value;
347        if (!reg_info || !reg_ctx)
348        {
349            error.SetErrorString("unable to retrieve register info");
350            return false;
351        }
352        error = reg_value.SetValueFromCString(reg_info, value_str);
353        if (error.Fail())
354            return false;
355        if (reg_ctx->WriteRegister (reg_info, reg_value))
356        {
357            SetNeedsUpdate();
358            return true;
359        }
360        else
361        {
362            error.SetErrorString("unable to write back to register");
363            return false;
364        }
365    }
366    else
367        return ValueObject::SetValueFromCString(value_str, error);
368}
369
370bool
371ValueObjectVariable::SetData (DataExtractor &data, Error &error)
372{
373    if (m_resolved_value.GetContextType() == Value::eContextTypeRegisterInfo)
374    {
375        RegisterInfo *reg_info = m_resolved_value.GetRegisterInfo();
376        ExecutionContext exe_ctx(GetExecutionContextRef());
377        RegisterContext *reg_ctx = exe_ctx.GetRegisterContext();
378        RegisterValue reg_value;
379        if (!reg_info || !reg_ctx)
380        {
381            error.SetErrorString("unable to retrieve register info");
382            return false;
383        }
384        error = reg_value.SetValueFromData(reg_info, data, 0, false);
385        if (error.Fail())
386            return false;
387        if (reg_ctx->WriteRegister (reg_info, reg_value))
388        {
389            SetNeedsUpdate();
390            return true;
391        }
392        else
393        {
394            error.SetErrorString("unable to write back to register");
395            return false;
396        }
397    }
398    else
399        return ValueObject::SetData(data, error);
400}
401