teak-llvm/lldb/source/Core/ValueObjectMemory.cpp
Greg Clayton e1cd1be6d6 Switching back to using std::tr1::shared_ptr. We originally switched away
due to RTTI worries since llvm and clang don't use RTTI, but I was able to 
switch back with no issues as far as I can tell. Once the RTTI issue wasn't
an issue, we were looking for a way to properly track weak pointers to objects
to solve some of the threading issues we have been running into which naturally
led us back to std::tr1::weak_ptr. We also wanted the ability to make a shared 
pointer from just a pointer, which is also easily solved using the 
std::tr1::enable_shared_from_this class. 

The main reason for this move back is so we can start properly having weak
references to objects. Currently a lldb_private::Thread class has a refrence
to its parent lldb_private::Process. This doesn't work well when we now hand
out a SBThread object that contains a shared pointer to a lldb_private::Thread
as this SBThread can be held onto by external clients and if they end up
using one of these objects we can easily crash.

So the next task is to start adopting std::tr1::weak_ptr where ever it makes
sense which we can do with lldb_private::Debugger, lldb_private::Target,
lldb_private::Process, lldb_private::Thread, lldb_private::StackFrame, and
many more objects now that they are no longer using intrusive ref counted
pointer objects (you can't do std::tr1::weak_ptr functionality with intrusive
pointers).

llvm-svn: 149207
2012-01-29 20:56:30 +00:00

279 lines
8.7 KiB
C++

//===-- ValueObjectMemory.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/ValueObjectMemory.h"
// C Includes
// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/Core/Module.h"
#include "lldb/Core/ValueObjectList.h"
#include "lldb/Core/Value.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Symbol/SymbolContext.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;
using namespace lldb_private;
ValueObjectSP
ValueObjectMemory::Create (ExecutionContextScope *exe_scope,
const char *name,
const Address &address,
lldb::TypeSP &type_sp)
{
return (new ValueObjectMemory (exe_scope, name, address, type_sp))->GetSP();
}
ValueObjectSP
ValueObjectMemory::Create (ExecutionContextScope *exe_scope,
const char *name,
const Address &address,
const ClangASTType &ast_type)
{
return (new ValueObjectMemory (exe_scope, name, address, ast_type))->GetSP();
}
ValueObjectMemory::ValueObjectMemory (ExecutionContextScope *exe_scope,
const char *name,
const Address &address,
lldb::TypeSP &type_sp) :
ValueObject(exe_scope),
m_address (address),
m_type_sp(type_sp),
m_clang_type()
{
// Do not attempt to construct one of these objects with no variable!
assert (m_type_sp.get() != NULL);
SetName (ConstString(name));
m_value.SetContext(Value::eContextTypeLLDBType, m_type_sp.get());
lldb::addr_t load_address = m_address.GetLoadAddress(m_update_point.GetTargetSP().get());
if (load_address != LLDB_INVALID_ADDRESS)
{
m_value.SetValueType(Value::eValueTypeLoadAddress);
m_value.GetScalar() = load_address;
}
else
{
lldb::addr_t file_address = m_address.GetFileAddress();
if (file_address != LLDB_INVALID_ADDRESS)
{
m_value.SetValueType(Value::eValueTypeFileAddress);
m_value.GetScalar() = file_address;
}
else
{
m_value.GetScalar() = m_address.GetOffset();
m_value.SetValueType (Value::eValueTypeScalar);
}
}
}
ValueObjectMemory::ValueObjectMemory (ExecutionContextScope *exe_scope,
const char *name,
const Address &address,
const ClangASTType &ast_type) :
ValueObject(exe_scope),
m_address (address),
m_type_sp(),
m_clang_type(ast_type)
{
// Do not attempt to construct one of these objects with no variable!
assert (m_clang_type.GetASTContext());
assert (m_clang_type.GetOpaqueQualType());
SetName (ConstString(name));
m_value.SetContext(Value::eContextTypeClangType, m_clang_type.GetOpaqueQualType());
lldb::addr_t load_address = m_address.GetLoadAddress(m_update_point.GetTargetSP().get());
if (load_address != LLDB_INVALID_ADDRESS)
{
m_value.SetValueType(Value::eValueTypeLoadAddress);
m_value.GetScalar() = load_address;
}
else
{
lldb::addr_t file_address = m_address.GetFileAddress();
if (file_address != LLDB_INVALID_ADDRESS)
{
m_value.SetValueType(Value::eValueTypeFileAddress);
m_value.GetScalar() = file_address;
}
else
{
m_value.GetScalar() = m_address.GetOffset();
m_value.SetValueType (Value::eValueTypeScalar);
}
}
}
ValueObjectMemory::~ValueObjectMemory()
{
}
lldb::clang_type_t
ValueObjectMemory::GetClangType ()
{
if (m_type_sp)
return m_type_sp->GetClangForwardType();
return m_clang_type.GetOpaqueQualType();
}
ConstString
ValueObjectMemory::GetTypeName()
{
if (m_type_sp)
return m_type_sp->GetName();
return ClangASTType::GetConstTypeName (m_clang_type.GetOpaqueQualType());
}
uint32_t
ValueObjectMemory::CalculateNumChildren()
{
if (m_type_sp)
return m_type_sp->GetNumChildren(true);
const bool omit_empty_base_classes = true;
return ClangASTContext::GetNumChildren (m_clang_type.GetASTContext(),
m_clang_type.GetOpaqueQualType(),
omit_empty_base_classes);
}
clang::ASTContext *
ValueObjectMemory::GetClangAST ()
{
if (m_type_sp)
return m_type_sp->GetClangAST();
return m_clang_type.GetASTContext();
}
size_t
ValueObjectMemory::GetByteSize()
{
if (m_type_sp)
return m_type_sp->GetByteSize();
return (m_clang_type.GetClangTypeBitWidth () + 7) / 8;
}
lldb::ValueType
ValueObjectMemory::GetValueType() const
{
// RETHINK: Should this be inherited from somewhere?
return lldb::eValueTypeVariableGlobal;
}
bool
ValueObjectMemory::UpdateValue ()
{
SetValueIsValid (false);
m_error.Clear();
ExecutionContext exe_ctx (GetExecutionContextScope());
Target *target = exe_ctx.GetTargetPtr();
if (target)
{
m_data.SetByteOrder(target->GetArchitecture().GetByteOrder());
m_data.SetAddressByteSize(target->GetArchitecture().GetAddressByteSize());
}
Value old_value(m_value);
if (m_address.IsValid())
{
Value::ValueType value_type = m_value.GetValueType();
switch (value_type)
{
default:
assert(!"Unhandled expression result value kind...");
break;
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, GetClangAST(), m_data, 0, GetModule());
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 && exe_ctx.GetProcessPtr())
{
lldb::addr_t load_addr = m_address.GetLoadAddress(target);
if (load_addr != LLDB_INVALID_ADDRESS)
{
m_value.SetValueType(Value::eValueTypeLoadAddress);
m_value.GetScalar() = load_addr;
}
}
if (ClangASTContext::IsAggregateType (GetClangType()))
{
// 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);
if (m_type_sp)
value.SetContext(Value::eContextTypeLLDBType, m_type_sp.get());
else
value.SetContext(Value::eContextTypeClangType, m_clang_type.GetOpaqueQualType());
m_error = value.GetValueAsData(&exe_ctx, GetClangAST(), m_data, 0, GetModule());
}
break;
}
SetValueIsValid (m_error.Success());
}
return m_error.Success();
}
bool
ValueObjectMemory::IsInScope ()
{
// FIXME: Maybe try to read the memory address, and if that works, then
// we are in scope?
return true;
}
Module *
ValueObjectMemory::GetModule()
{
return m_address.GetModulePtr();
}