llvm-capstone/lldb/source/Core/ValueObjectChild.cpp
Enrico Granata 4873e52733 <rdar://problem/13623698>
This patch fixes the issue that we were using the C stack as a measure of depth of ValueObject hierarchies, in the sense that we were assuming that recursive ValueObject operations would never be deeper than the stack allows.
This assumption is easy to prove wrong, however.
For instance, after ~10k runs through this loop:
struct node
{
	int value;
	node* child;
	node (int x)
	{
		value = x;
		child = nullptr;
	}
};

int main ()
{
	node root(1);
	node* ptr = &root;
	int j = 2;
	while (1)
	{
		ptr->child = new node(j++);
		ptr = ptr->child;
	}
	return 0;
}

the deepmost child object will be deeper than the stack on most architectures, and we would be unable to display it

This checkin fixes the issue by introducing a notion of root of ValueObject hierarchies.
In a couple cases, we have to use an iterative algorithm instead of going to the root because we want to allow deeper customizations (e.g. formats, dynamic values).
While the patch passes our test suite without regressions, it is a good idea to keep eyes open for any unexpected behavior (recursion can be subtle..)
Also, I am hesitant to introduce a test case since failing at this will not just be marked as an "F", but most definitely crash LLDB.

llvm-svn: 179330
2013-04-11 22:48:58 +00:00

237 lines
7.7 KiB
C++

//===-- ValueObjectChild.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/ValueObjectChild.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/ValueObjectList.h"
#include "lldb/Symbol/ClangASTType.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/Target.h"
using namespace lldb_private;
ValueObjectChild::ValueObjectChild
(
ValueObject &parent,
clang::ASTContext *clang_ast,
void *clang_type,
const ConstString &name,
uint64_t byte_size,
int32_t byte_offset,
uint32_t bitfield_bit_size,
uint32_t bitfield_bit_offset,
bool is_base_class,
bool is_deref_of_parent,
AddressType child_ptr_or_ref_addr_type
) :
ValueObject (parent),
m_clang_ast (clang_ast),
m_clang_type (clang_type),
m_byte_size (byte_size),
m_byte_offset (byte_offset),
m_bitfield_bit_size (bitfield_bit_size),
m_bitfield_bit_offset (bitfield_bit_offset),
m_is_base_class (is_base_class),
m_is_deref_of_parent (is_deref_of_parent)
{
m_name = name;
SetAddressTypeOfChildren(child_ptr_or_ref_addr_type);
}
ValueObjectChild::~ValueObjectChild()
{
}
lldb::ValueType
ValueObjectChild::GetValueType() const
{
return m_parent->GetValueType();
}
size_t
ValueObjectChild::CalculateNumChildren()
{
return ClangASTContext::GetNumChildren (GetClangAST (), GetClangType(), true);
}
ConstString
ValueObjectChild::GetTypeName()
{
if (m_type_name.IsEmpty())
{
m_type_name = ClangASTType::GetConstTypeName (GetClangAST(), GetClangType());
if (m_type_name)
{
if (m_bitfield_bit_size > 0)
{
const char *clang_type_name = m_type_name.AsCString();
if (clang_type_name)
{
std::vector<char> bitfield_type_name (strlen(clang_type_name) + 32, 0);
::snprintf (&bitfield_type_name.front(), bitfield_type_name.size(), "%s:%u", clang_type_name, m_bitfield_bit_size);
m_type_name.SetCString(&bitfield_type_name.front());
}
}
}
}
return m_type_name;
}
ConstString
ValueObjectChild::GetQualifiedTypeName()
{
ConstString qualified_name = ClangASTType::GetConstQualifiedTypeName (GetClangAST(), GetClangType());
if (qualified_name)
{
if (m_bitfield_bit_size > 0)
{
const char *clang_type_name = qualified_name.AsCString();
if (clang_type_name)
{
std::vector<char> bitfield_type_name (strlen(clang_type_name) + 32, 0);
::snprintf (&bitfield_type_name.front(), bitfield_type_name.size(), "%s:%u", clang_type_name, m_bitfield_bit_size);
qualified_name.SetCString(&bitfield_type_name.front());
}
}
}
return qualified_name;
}
bool
ValueObjectChild::UpdateValue ()
{
m_error.Clear();
SetValueIsValid (false);
ValueObject* parent = m_parent;
if (parent)
{
if (parent->UpdateValueIfNeeded(false))
{
m_value.SetContext(Value::eContextTypeClangType, GetClangType());
// Copy the parent scalar value and the scalar value type
m_value.GetScalar() = parent->GetValue().GetScalar();
Value::ValueType value_type = parent->GetValue().GetValueType();
m_value.SetValueType (value_type);
if (ClangASTContext::IsPointerOrReferenceType (parent->GetClangType()))
{
lldb::addr_t addr = parent->GetPointerValue ();
m_value.GetScalar() = addr;
if (addr == LLDB_INVALID_ADDRESS)
{
m_error.SetErrorString ("parent address is invalid.");
}
else if (addr == 0)
{
m_error.SetErrorString ("parent is NULL");
}
else
{
m_value.GetScalar() += m_byte_offset;
AddressType addr_type = parent->GetAddressTypeOfChildren();
switch (addr_type)
{
case eAddressTypeFile:
{
lldb::ProcessSP process_sp (GetProcessSP());
if (process_sp && process_sp->IsAlive() == true)
m_value.SetValueType (Value::eValueTypeLoadAddress);
else
m_value.SetValueType(Value::eValueTypeFileAddress);
}
break;
case eAddressTypeLoad:
m_value.SetValueType (Value::eValueTypeLoadAddress);
break;
case eAddressTypeHost:
m_value.SetValueType(Value::eValueTypeHostAddress);
break;
case eAddressTypeInvalid:
// TODO: does this make sense?
m_value.SetValueType(Value::eValueTypeScalar);
break;
}
}
}
else
{
switch (value_type)
{
case Value::eValueTypeLoadAddress:
case Value::eValueTypeFileAddress:
case Value::eValueTypeHostAddress:
{
lldb::addr_t addr = m_value.GetScalar().ULongLong(LLDB_INVALID_ADDRESS);
if (addr == LLDB_INVALID_ADDRESS)
{
m_error.SetErrorString ("parent address is invalid.");
}
else if (addr == 0)
{
m_error.SetErrorString ("parent is NULL");
}
else
{
// Set this object's scalar value to the address of its
// value by adding its byte offset to the parent address
m_value.GetScalar() += GetByteOffset();
}
}
break;
case Value::eValueTypeScalar:
// TODO: What if this is a register value? Do we try and
// extract the child value from within the parent data?
// Probably...
default:
m_error.SetErrorString ("parent has invalid value.");
break;
}
}
if (m_error.Success())
{
ExecutionContext exe_ctx (GetExecutionContextRef().Lock());
m_error = m_value.GetValueAsData (&exe_ctx, GetClangAST (), m_data, 0, GetModule().get());
}
}
else
{
m_error.SetErrorStringWithFormat("parent failed to evaluate: %s", parent->GetError().AsCString());
}
}
else
{
m_error.SetErrorString("ValueObjectChild has a NULL parent ValueObject.");
}
return m_error.Success();
}
bool
ValueObjectChild::IsInScope ()
{
ValueObject* root(GetRoot());
if (root)
return root->IsInScope ();
return false;
}