//===-- ValueObjectVariable.cpp ---------------------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "lldb/Core/ValueObjectVariable.h" // C Includes // C++ Includes // Other libraries and framework includes // Project includes #include "lldb/Core/Module.h" #include "lldb/Core/RegisterValue.h" #include "lldb/Core/ValueObjectList.h" #include "lldb/Core/Value.h" #include "lldb/Symbol/Function.h" #include "lldb/Symbol/ObjectFile.h" #include "lldb/Symbol/SymbolContext.h" #include "lldb/Symbol/SymbolContextScope.h" #include "lldb/Symbol/Type.h" #include "lldb/Symbol/Variable.h" #include "lldb/Target/ExecutionContext.h" #include "lldb/Target/Process.h" #include "lldb/Target/RegisterContext.h" #include "lldb/Target/Target.h" #include "lldb/Target/Thread.h" using namespace lldb_private; lldb::ValueObjectSP ValueObjectVariable::Create (ExecutionContextScope *exe_scope, const lldb::VariableSP &var_sp) { return (new ValueObjectVariable (exe_scope, var_sp))->GetSP(); } ValueObjectVariable::ValueObjectVariable (ExecutionContextScope *exe_scope, const lldb::VariableSP &var_sp) : ValueObject(exe_scope), m_variable_sp(var_sp) { // Do not attempt to construct one of these objects with no variable! assert (m_variable_sp.get() != NULL); m_name = var_sp->GetName(); } ValueObjectVariable::~ValueObjectVariable() { } CompilerType ValueObjectVariable::GetCompilerTypeImpl () { Type *var_type = m_variable_sp->GetType(); if (var_type) return var_type->GetForwardCompilerType (); return CompilerType(); } ConstString ValueObjectVariable::GetTypeName() { Type * var_type = m_variable_sp->GetType(); if (var_type) return var_type->GetName(); return ConstString(); } ConstString ValueObjectVariable::GetDisplayTypeName() { Type * var_type = m_variable_sp->GetType(); if (var_type) return var_type->GetForwardCompilerType ().GetDisplayTypeName(); return ConstString(); } ConstString ValueObjectVariable::GetQualifiedTypeName() { Type * var_type = m_variable_sp->GetType(); if (var_type) return var_type->GetQualifiedName(); return ConstString(); } size_t ValueObjectVariable::CalculateNumChildren(uint32_t max) { CompilerType type(GetCompilerType()); if (!type.IsValid()) return 0; const bool omit_empty_base_classes = true; auto child_count = type.GetNumChildren(omit_empty_base_classes); return child_count <= max ? child_count : max; } uint64_t ValueObjectVariable::GetByteSize() { ExecutionContext exe_ctx(GetExecutionContextRef()); CompilerType type(GetCompilerType()); if (!type.IsValid()) return 0; return type.GetByteSize(exe_ctx.GetBestExecutionContextScope()); } lldb::ValueType ValueObjectVariable::GetValueType() const { if (m_variable_sp) return m_variable_sp->GetScope(); return lldb::eValueTypeInvalid; } bool ValueObjectVariable::UpdateValue () { SetValueIsValid (false); m_error.Clear(); Variable *variable = m_variable_sp.get(); DWARFExpression &expr = variable->LocationExpression(); if (variable->GetLocationIsConstantValueData()) { // expr doesn't contain DWARF bytes, it contains the constant variable // value bytes themselves... if (expr.GetExpressionData(m_data)) m_value.SetContext(Value::eContextTypeVariable, variable); else m_error.SetErrorString ("empty constant data"); // constant bytes can't be edited - sorry m_resolved_value.SetContext(Value::eContextTypeInvalid, NULL); } else { lldb::addr_t loclist_base_load_addr = LLDB_INVALID_ADDRESS; ExecutionContext exe_ctx (GetExecutionContextRef()); Target *target = exe_ctx.GetTargetPtr(); if (target) { m_data.SetByteOrder(target->GetArchitecture().GetByteOrder()); m_data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize()); } if (expr.IsLocationList()) { SymbolContext sc; variable->CalculateSymbolContext (&sc); if (sc.function) loclist_base_load_addr = sc.function->GetAddressRange().GetBaseAddress().GetLoadAddress (target); } Value old_value(m_value); if (expr.Evaluate (&exe_ctx, nullptr, nullptr, nullptr, loclist_base_load_addr, nullptr, nullptr, m_value, &m_error)) { m_resolved_value = m_value; m_value.SetContext(Value::eContextTypeVariable, variable); CompilerType compiler_type = GetCompilerType(); if (compiler_type.IsValid()) m_value.SetCompilerType(compiler_type); Value::ValueType value_type = m_value.GetValueType(); Process *process = exe_ctx.GetProcessPtr(); const bool process_is_alive = process && process->IsAlive(); const uint32_t type_info = compiler_type.GetTypeInfo(); const bool is_pointer_or_ref = (type_info & (lldb::eTypeIsPointer | lldb::eTypeIsReference)) != 0; switch (value_type) { case Value::eValueTypeFileAddress: // If this type is a pointer, then its children will be considered load addresses // if the pointer or reference is dereferenced, but only if the process is alive. // // There could be global variables like in the following code: // struct LinkedListNode { Foo* foo; LinkedListNode* next; }; // Foo g_foo1; // Foo g_foo2; // LinkedListNode g_second_node = { &g_foo2, NULL }; // LinkedListNode g_first_node = { &g_foo1, &g_second_node }; // // When we aren't running, we should be able to look at these variables using // the "target variable" command. Children of the "g_first_node" always will // be of the same address type as the parent. But children of the "next" member of // LinkedListNode will become load addresses if we have a live process, or remain // what a file address if it what a file address. if (process_is_alive && is_pointer_or_ref) SetAddressTypeOfChildren(eAddressTypeLoad); else SetAddressTypeOfChildren(eAddressTypeFile); break; case Value::eValueTypeHostAddress: // Same as above for load addresses, except children of pointer or refs are always // load addresses. Host addresses are used to store freeze dried variables. If this // type is a struct, the entire struct contents will be copied into the heap of the // LLDB process, but we do not currrently follow any pointers. if (is_pointer_or_ref) SetAddressTypeOfChildren(eAddressTypeLoad); else SetAddressTypeOfChildren(eAddressTypeHost); break; case Value::eValueTypeLoadAddress: case Value::eValueTypeScalar: case Value::eValueTypeVector: SetAddressTypeOfChildren(eAddressTypeLoad); break; } switch (value_type) { case Value::eValueTypeVector: // fall through case Value::eValueTypeScalar: // The variable value is in the Scalar value inside the m_value. // We can point our m_data right to it. m_error = m_value.GetValueAsData (&exe_ctx, m_data, 0, GetModule().get()); break; case Value::eValueTypeFileAddress: case Value::eValueTypeLoadAddress: case Value::eValueTypeHostAddress: // The DWARF expression result was an address in the inferior // process. If this variable is an aggregate type, we just need // the address as the main value as all child variable objects // will rely upon this location and add an offset and then read // their own values as needed. If this variable is a simple // type, we read all data for it into m_data. // Make sure this type has a value before we try and read it // If we have a file address, convert it to a load address if we can. if (value_type == Value::eValueTypeFileAddress && process_is_alive) { lldb::addr_t file_addr = m_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS); if (file_addr != LLDB_INVALID_ADDRESS) { SymbolContext var_sc; variable->CalculateSymbolContext(&var_sc); if (var_sc.module_sp) { ObjectFile *objfile = var_sc.module_sp->GetObjectFile(); if (objfile) { Address so_addr(file_addr, objfile->GetSectionList()); lldb::addr_t load_addr = so_addr.GetLoadAddress (target); if (load_addr != LLDB_INVALID_ADDRESS) { m_value.SetValueType(Value::eValueTypeLoadAddress); m_value.GetScalar() = load_addr; } } } } } if (!CanProvideValue()) { // this value object represents an aggregate type whose // children have values, but this object does not. So we // say we are changed if our location has changed. SetValueDidChange (value_type != old_value.GetValueType() || m_value.GetScalar() != old_value.GetScalar()); } else { // Copy the Value and set the context to use our Variable // so it can extract read its value into m_data appropriately Value value(m_value); value.SetContext(Value::eContextTypeVariable, variable); m_error = value.GetValueAsData(&exe_ctx, m_data, 0, GetModule().get()); SetValueDidChange (value_type != old_value.GetValueType() || m_value.GetScalar() != old_value.GetScalar()); } break; } SetValueIsValid (m_error.Success()); } else { // could not find location, won't allow editing m_resolved_value.SetContext(Value::eContextTypeInvalid, NULL); } } return m_error.Success(); } bool ValueObjectVariable::IsInScope () { const ExecutionContextRef &exe_ctx_ref = GetExecutionContextRef(); if (exe_ctx_ref.HasFrameRef()) { ExecutionContext exe_ctx (exe_ctx_ref); StackFrame *frame = exe_ctx.GetFramePtr(); if (frame) { return m_variable_sp->IsInScope (frame); } else { // This ValueObject had a frame at one time, but now we // can't locate it, so return false since we probably aren't // in scope. return false; } } // We have a variable that wasn't tied to a frame, which // means it is a global and is always in scope. return true; } lldb::ModuleSP ValueObjectVariable::GetModule() { if (m_variable_sp) { SymbolContextScope *sc_scope = m_variable_sp->GetSymbolContextScope(); if (sc_scope) { return sc_scope->CalculateSymbolContextModule(); } } return lldb::ModuleSP(); } SymbolContextScope * ValueObjectVariable::GetSymbolContextScope() { if (m_variable_sp) return m_variable_sp->GetSymbolContextScope(); return NULL; } bool ValueObjectVariable::GetDeclaration (Declaration &decl) { if (m_variable_sp) { decl = m_variable_sp->GetDeclaration(); return true; } return false; } const char * ValueObjectVariable::GetLocationAsCString () { if (m_resolved_value.GetContextType() == Value::eContextTypeRegisterInfo) return GetLocationAsCStringImpl(m_resolved_value, m_data); else return ValueObject::GetLocationAsCString(); } bool ValueObjectVariable::SetValueFromCString (const char *value_str, Error& error) { if (!UpdateValueIfNeeded()) { error.SetErrorString("unable to update value before writing"); return false; } if (m_resolved_value.GetContextType() == Value::eContextTypeRegisterInfo) { RegisterInfo *reg_info = m_resolved_value.GetRegisterInfo(); ExecutionContext exe_ctx(GetExecutionContextRef()); RegisterContext *reg_ctx = exe_ctx.GetRegisterContext(); RegisterValue reg_value; if (!reg_info || !reg_ctx) { error.SetErrorString("unable to retrieve register info"); return false; } error = reg_value.SetValueFromCString(reg_info, value_str); if (error.Fail()) return false; if (reg_ctx->WriteRegister (reg_info, reg_value)) { SetNeedsUpdate(); return true; } else { error.SetErrorString("unable to write back to register"); return false; } } else return ValueObject::SetValueFromCString(value_str, error); } bool ValueObjectVariable::SetData (DataExtractor &data, Error &error) { if (!UpdateValueIfNeeded()) { error.SetErrorString("unable to update value before writing"); return false; } if (m_resolved_value.GetContextType() == Value::eContextTypeRegisterInfo) { RegisterInfo *reg_info = m_resolved_value.GetRegisterInfo(); ExecutionContext exe_ctx(GetExecutionContextRef()); RegisterContext *reg_ctx = exe_ctx.GetRegisterContext(); RegisterValue reg_value; if (!reg_info || !reg_ctx) { error.SetErrorString("unable to retrieve register info"); return false; } error = reg_value.SetValueFromData(reg_info, data, 0, true); if (error.Fail()) return false; if (reg_ctx->WriteRegister (reg_info, reg_value)) { SetNeedsUpdate(); return true; } else { error.SetErrorString("unable to write back to register"); return false; } } else return ValueObject::SetData(data, error); }