lldb/source/Plugins/Language/CPlusPlus/LibStdcpp.cpp

//===-- LibStdcpp.cpp ---------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "LibStdcpp.h"

#include "lldb/Core/DataBufferHeap.h"
#include "lldb/Core/Error.h"
#include "lldb/Core/Stream.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/DataFormatters/StringPrinter.h"
#include "lldb/DataFormatters/VectorIterator.h"
#include "lldb/Host/Endian.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Target/Target.h"

using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::formatters;

class LibstdcppMapIteratorSyntheticFrontEnd : public SyntheticChildrenFrontEnd
{
public:
    LibstdcppMapIteratorSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp);
    
    size_t
    CalculateNumChildren() override;
    
    lldb::ValueObjectSP
    GetChildAtIndex(size_t idx) override;
    
    bool
    Update() override;
    
    bool
    MightHaveChildren() override;
    
    size_t
    GetIndexOfChildWithName (const ConstString &name) override;
    
    ~LibstdcppMapIteratorSyntheticFrontEnd() override;
    
private:
    ExecutionContextRef m_exe_ctx_ref;
    lldb::addr_t m_pair_address;
    CompilerType m_pair_type;
    EvaluateExpressionOptions m_options;
    lldb::ValueObjectSP m_pair_sp;
};

/*
 (std::_Rb_tree_iterator<std::pair<const int, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >) ibeg = {
 (_Base_ptr) _M_node = 0x0000000100103910 {
 (std::_Rb_tree_color) _M_color = _S_black
 (std::_Rb_tree_node_base::_Base_ptr) _M_parent = 0x00000001001038c0
 (std::_Rb_tree_node_base::_Base_ptr) _M_left = 0x0000000000000000
 (std::_Rb_tree_node_base::_Base_ptr) _M_right = 0x0000000000000000
 }
 }
 */

LibstdcppMapIteratorSyntheticFrontEnd::LibstdcppMapIteratorSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp) :
    SyntheticChildrenFrontEnd(*valobj_sp.get()),
    m_exe_ctx_ref(),
    m_pair_address(0),
    m_pair_type(),
    m_options(),
    m_pair_sp()
{
    if (valobj_sp)
        Update();
    m_options.SetCoerceToId(false);
    m_options.SetUnwindOnError(true);
    m_options.SetKeepInMemory(true);
    m_options.SetUseDynamic(lldb::eDynamicCanRunTarget);
}

bool
LibstdcppMapIteratorSyntheticFrontEnd::Update()
{
    ValueObjectSP valobj_sp = m_backend.GetSP();
    if (!valobj_sp)
        return false;
    
    TargetSP target_sp(valobj_sp->GetTargetSP());
    
    if (!target_sp)
        return false;
    
    bool is_64bit = (target_sp->GetArchitecture().GetAddressByteSize() == 8);
    
    if (!valobj_sp)
        return false;
    m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
    
    ValueObjectSP _M_node_sp(valobj_sp->GetChildMemberWithName(ConstString("_M_node"), true));
    if (!_M_node_sp)
        return false;
    
    m_pair_address = _M_node_sp->GetValueAsUnsigned(0);
    if (m_pair_address == 0)
        return false;
    
    m_pair_address += (is_64bit ? 32 : 16);
    
    CompilerType my_type(valobj_sp->GetCompilerType());
    if (my_type.GetNumTemplateArguments() >= 1)
    {
        TemplateArgumentKind kind;
        CompilerType pair_type = my_type.GetTemplateArgument(0, kind);
        if (kind != eTemplateArgumentKindType && kind != eTemplateArgumentKindTemplate && kind != eTemplateArgumentKindTemplateExpansion)
            return false;
        m_pair_type = pair_type;
    }
    else
        return false;
    
    return true;
}

size_t
LibstdcppMapIteratorSyntheticFrontEnd::CalculateNumChildren ()
{
    return 2;
}

lldb::ValueObjectSP
LibstdcppMapIteratorSyntheticFrontEnd::GetChildAtIndex (size_t idx)
{
    if (m_pair_address != 0 && m_pair_type)
    {
        if (!m_pair_sp)
            m_pair_sp = CreateValueObjectFromAddress("pair", m_pair_address, m_exe_ctx_ref, m_pair_type);
        if (m_pair_sp)
            return m_pair_sp->GetChildAtIndex(idx, true);
    }
    return lldb::ValueObjectSP();
}

bool
LibstdcppMapIteratorSyntheticFrontEnd::MightHaveChildren ()
{
    return true;
}

size_t
LibstdcppMapIteratorSyntheticFrontEnd::GetIndexOfChildWithName (const ConstString &name)
{
    if (name == ConstString("first"))
        return 0;
    if (name == ConstString("second"))
        return 1;
    return UINT32_MAX;
}

LibstdcppMapIteratorSyntheticFrontEnd::~LibstdcppMapIteratorSyntheticFrontEnd ()
{}

SyntheticChildrenFrontEnd*
lldb_private::formatters::LibstdcppMapIteratorSyntheticFrontEndCreator (CXXSyntheticChildren*, lldb::ValueObjectSP valobj_sp)
{
    if (!valobj_sp)
        return NULL;
    return (new LibstdcppMapIteratorSyntheticFrontEnd(valobj_sp));
}

/*
 (lldb) fr var ibeg --ptr-depth 1
 (__gnu_cxx::__normal_iterator<int *, std::vector<int, std::allocator<int> > >) ibeg = {
 _M_current = 0x00000001001037a0 {
 *_M_current = 1
 }
 }
 */

SyntheticChildrenFrontEnd*
lldb_private::formatters::LibStdcppVectorIteratorSyntheticFrontEndCreator (CXXSyntheticChildren*, lldb::ValueObjectSP valobj_sp)
{
    static ConstString g_item_name;
    if (!g_item_name)
        g_item_name.SetCString("_M_current");
    if (!valobj_sp)
        return NULL;
    return (new VectorIteratorSyntheticFrontEnd(valobj_sp,g_item_name));
}

lldb_private::formatters::VectorIteratorSyntheticFrontEnd::VectorIteratorSyntheticFrontEnd (lldb::ValueObjectSP valobj_sp,
                                                                                            ConstString item_name) :
SyntheticChildrenFrontEnd(*valobj_sp.get()),
m_exe_ctx_ref(),
m_item_name(item_name),
m_item_sp()
{
    if (valobj_sp)
        Update();
}

bool
lldb_private::formatters::VectorIteratorSyntheticFrontEnd::Update()
{
    m_item_sp.reset();
    
    ValueObjectSP valobj_sp = m_backend.GetSP();
    if (!valobj_sp)
        return false;
    
    if (!valobj_sp)
        return false;
    
    ValueObjectSP item_ptr(valobj_sp->GetChildMemberWithName(m_item_name,true));
    if (!item_ptr)
        return false;
    if (item_ptr->GetValueAsUnsigned(0) == 0)
        return false;
    Error err;
    m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
    m_item_sp = CreateValueObjectFromAddress("item", item_ptr->GetValueAsUnsigned(0), m_exe_ctx_ref, item_ptr->GetCompilerType().GetPointeeType());
    if (err.Fail())
        m_item_sp.reset();
    return false;
}

size_t
lldb_private::formatters::VectorIteratorSyntheticFrontEnd::CalculateNumChildren ()
{
    return 1;
}

lldb::ValueObjectSP
lldb_private::formatters::VectorIteratorSyntheticFrontEnd::GetChildAtIndex (size_t idx)
{
    if (idx == 0)
        return m_item_sp;
    return lldb::ValueObjectSP();
}

bool
lldb_private::formatters::VectorIteratorSyntheticFrontEnd::MightHaveChildren ()
{
    return true;
}

size_t
lldb_private::formatters::VectorIteratorSyntheticFrontEnd::GetIndexOfChildWithName (const ConstString &name)
{
    if (name == ConstString("item"))
        return 0;
    return UINT32_MAX;
}

lldb_private::formatters::VectorIteratorSyntheticFrontEnd::~VectorIteratorSyntheticFrontEnd ()
{
}

bool
lldb_private::formatters::LibStdcppStringSummaryProvider (ValueObject& valobj, Stream& stream, const TypeSummaryOptions& options)
{
    const bool scalar_is_load_addr = true;
    AddressType addr_type;
    lldb::addr_t addr_of_string = valobj.GetAddressOf(scalar_is_load_addr, &addr_type);
    if (addr_of_string != LLDB_INVALID_ADDRESS)
    {
        switch (addr_type)
        {
            case eAddressTypeLoad:
            {
                ProcessSP process_sp(valobj.GetProcessSP());
                if (!process_sp)
                    return false;

                StringPrinter::ReadStringAndDumpToStreamOptions options(valobj);
                Error error;
                lldb::addr_t addr_of_data = process_sp->ReadPointerFromMemory(addr_of_string, error);
                if (error.Fail() || addr_of_data == 0 || addr_of_data == LLDB_INVALID_ADDRESS)
                    return false;
                options.SetLocation(addr_of_data);
                options.SetProcessSP(process_sp);
                options.SetStream(&stream);
                options.SetNeedsZeroTermination(false);
                options.SetBinaryZeroIsTerminator(true);
                lldb::addr_t size_of_data = process_sp->ReadPointerFromMemory(addr_of_string + process_sp->GetAddressByteSize(), error);
                if (error.Fail())
                    return false;
                options.SetSourceSize(size_of_data);

                if (!StringPrinter::ReadStringAndDumpToStream<StringPrinter::StringElementType::UTF8>(options))
                {
                    stream.Printf("Summary Unavailable");
                    return true;
                }
                else
                    return true;
            }
                break;
            case eAddressTypeHost:
                break;
            case eAddressTypeInvalid:
            case eAddressTypeFile:
                break;
        }
    }
    return false;
}

bool
lldb_private::formatters::LibStdcppWStringSummaryProvider (ValueObject& valobj, Stream& stream, const TypeSummaryOptions& options)
{
    const bool scalar_is_load_addr = true;
    AddressType addr_type;
    lldb::addr_t addr_of_string = valobj.GetAddressOf(scalar_is_load_addr, &addr_type);
    if (addr_of_string != LLDB_INVALID_ADDRESS)
    {
        switch (addr_type)
        {
            case eAddressTypeLoad:
            {
                ProcessSP process_sp(valobj.GetProcessSP());
                if (!process_sp)
                    return false;

                CompilerType wchar_compiler_type = valobj.GetCompilerType().GetBasicTypeFromAST(lldb::eBasicTypeWChar);

                if (!wchar_compiler_type)
                    return false;

                const uint32_t wchar_size = wchar_compiler_type.GetBitSize(nullptr); // Safe to pass NULL for exe_scope here

                StringPrinter::ReadStringAndDumpToStreamOptions options(valobj);
                Error error;
                lldb::addr_t addr_of_data = process_sp->ReadPointerFromMemory(addr_of_string, error);
                if (error.Fail() || addr_of_data == 0 || addr_of_data == LLDB_INVALID_ADDRESS)
                    return false;
                options.SetLocation(addr_of_data);
                options.SetProcessSP(process_sp);
                options.SetStream(&stream);
                options.SetNeedsZeroTermination(false);
                options.SetBinaryZeroIsTerminator(false);
                lldb::addr_t size_of_data = process_sp->ReadPointerFromMemory(addr_of_string + process_sp->GetAddressByteSize(), error);
                if (error.Fail())
                    return false;
                options.SetSourceSize(size_of_data);
                options.SetPrefixToken("L");

                switch (wchar_size)
                {
                    case 8:
                        return StringPrinter::ReadStringAndDumpToStream<StringPrinter::StringElementType::UTF8>(options);
                    case 16:
                        return StringPrinter::ReadStringAndDumpToStream<StringPrinter::StringElementType::UTF16>(options);
                    case 32:
                        return StringPrinter::ReadStringAndDumpToStream<StringPrinter::StringElementType::UTF32>(options);
                    default:
                        stream.Printf("size for wchar_t is not valid");
                        return true;
                }
                return true;
            }
                break;
            case eAddressTypeHost:
                break;
            case eAddressTypeInvalid:
            case eAddressTypeFile:
                break;
        }
    }
    return false;
}