source/Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.cpp

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

#include "DWARFDebugInfoEntry.h"

#include <assert.h>

#include <algorithm>

#include "lldb/Core/Stream.h"
#include "lldb/Expression/DWARFExpression.h"
#include "lldb/Symbol/ObjectFile.h"

#include "DWARFCompileUnit.h"
#include "SymbolFileDWARF.h"
#include "DWARFDebugAbbrev.h"
#include "DWARFDebugAranges.h"
#include "DWARFDebugInfo.h"
#include "DWARFDIECollection.h"
#include "DWARFFormValue.h"
#include "DWARFLocationDescription.h"
#include "DWARFLocationList.h"
#include "DWARFDebugRanges.h"

using namespace lldb_private;
using namespace std;
extern int g_verbose;



DWARFDebugInfoEntry::Attributes::Attributes() :
    m_infos()
{
    m_infos.reserve(20);
}

DWARFDebugInfoEntry::Attributes::~Attributes()
{
}


uint32_t
DWARFDebugInfoEntry::Attributes::FindAttributeIndex(dw_attr_t attr) const
{
    std::vector<Info>::const_iterator end = m_infos.end();
    std::vector<Info>::const_iterator beg = m_infos.begin();
    std::vector<Info>::const_iterator pos;
    for (pos = beg; pos != end; ++pos)
    {
        if (pos->attr == attr)
            return std::distance(beg, pos);
    }
    return UINT_MAX;
}

void
DWARFDebugInfoEntry::Attributes::Append(const DWARFCompileUnit *cu, dw_offset_t attr_die_offset, dw_attr_t attr, dw_form_t form)
{
    Info info = { cu, attr_die_offset, attr, form };
    m_infos.push_back(info);
}

bool
DWARFDebugInfoEntry::Attributes::ContainsAttribute(dw_attr_t attr) const
{
    return FindAttributeIndex(attr) != UINT_MAX;
}

bool
DWARFDebugInfoEntry::Attributes::RemoveAttribute(dw_attr_t attr)
{
    uint32_t attr_index = FindAttributeIndex(attr);
    if (attr_index != UINT_MAX)
    {
        m_infos.erase(m_infos.begin() + attr_index);
        return true;
    }
    return false;
}

bool
DWARFDebugInfoEntry::Attributes::ExtractFormValueAtIndex (SymbolFileDWARF* dwarf2Data, uint32_t i, DWARFFormValue &form_value) const
{
    form_value.SetForm(FormAtIndex(i));
    dw_offset_t offset = DIEOffsetAtIndex(i);
    return form_value.ExtractValue(dwarf2Data->get_debug_info_data(), &offset, CompileUnitAtIndex(i));
}

uint64_t
DWARFDebugInfoEntry::Attributes::FormValueAsUnsignedAtIndex(SymbolFileDWARF* dwarf2Data, uint32_t i, uint64_t fail_value) const
{
    DWARFFormValue form_value;
    if (ExtractFormValueAtIndex(dwarf2Data, i, form_value))
        return form_value.Reference(CompileUnitAtIndex(i));
    return fail_value;
}


//----------------------------------------------------------------------
// Extract
//
// Extract a debug info entry for a given compile unit from the
// .debug_info and .debug_abbrev data within the SymbolFileDWARF class
// starting at the given offset
//----------------------------------------------------------------------
bool
DWARFDebugInfoEntry::Extract
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    uint32_t* offset_ptr
)
{
    const DataExtractor& debug_info_data = dwarf2Data->get_debug_info_data();
//    const DataExtractor& debug_str_data = dwarf2Data->get_debug_str_data();
    const uint32_t cu_end_offset = cu->GetNextCompileUnitOffset();
    const uint8_t cu_addr_size = cu->GetAddressByteSize();
    uint32_t offset = *offset_ptr;
//  if (offset >= cu_end_offset)
//      Log::Error("DIE at offset 0x%8.8x is beyond the end of the current compile unit (0x%8.8x)", m_offset, cu_end_offset);
    if ((offset < cu_end_offset) && debug_info_data.ValidOffset(offset))
    {
        m_offset = offset;

        dw_uleb128_t abbrCode = debug_info_data.GetULEB128(&offset);

        if (abbrCode)
        {
            m_abbrevDecl = cu->GetAbbreviations()->GetAbbreviationDeclaration(abbrCode);

            if (m_abbrevDecl)
            {
                dw_tag_t tag = m_abbrevDecl->Tag();

                bool isCompileUnitTag = tag == DW_TAG_compile_unit;
                if (cu && isCompileUnitTag)
                    ((DWARFCompileUnit*)cu)->SetBaseAddress(0);

                // Skip all data in the .debug_info for the attributes
                const uint32_t numAttributes = m_abbrevDecl->NumAttributes();
                uint32_t i;
                dw_attr_t attr;
                dw_form_t form;
                for (i=0; i<numAttributes; ++i)
                {
                    m_abbrevDecl->GetAttrAndFormByIndexUnchecked(i, attr, form);

                    if (isCompileUnitTag && ((attr == DW_AT_entry_pc) || (attr == DW_AT_low_pc)))
                    {
                        DWARFFormValue form_value(form);
                        if (form_value.ExtractValue(debug_info_data, &offset, cu))
                        {
                            if (attr == DW_AT_low_pc || attr == DW_AT_entry_pc)
                                ((DWARFCompileUnit*)cu)->SetBaseAddress(form_value.Unsigned());
                        }
                    }
                    else
                    {
die_extract_indirect_form:
                        register uint32_t form_size = 0;
                        switch (form)
                        {
                        // Blocks if inlined data that have a length field and the data bytes
                        // inlined in the .debug_info
                        case DW_FORM_block      : form_size = debug_info_data.GetULEB128(&offset);  break;
                        case DW_FORM_block1     : form_size = debug_info_data.GetU8(&offset);       break;
                        case DW_FORM_block2     : form_size = debug_info_data.GetU16(&offset);      break;
                        case DW_FORM_block4     : form_size = debug_info_data.GetU32(&offset);      break;

                        // Inlined NULL terminated C-strings
                        case DW_FORM_string     :
                            {
//                                const char *s = 
                                debug_info_data.GetCStr(&offset);
//                                switch (attr)
//                                {
//                                case DW_AT_name: m_name = s; break;
//                                case DW_AT_MIPS_linkage_name: m_linkage_name = s; break;
//                                default: break;
//                                }
                            }
                            break;

                        // Compile unit address sized values
                        case DW_FORM_addr       :
                        case DW_FORM_ref_addr   :
                            form_size = cu_addr_size;
                            break;

                        // 1 byte values
                        case DW_FORM_data1      :
                        case DW_FORM_flag       :
                        case DW_FORM_ref1       :
                            form_size = 1;
                            break;

                        // 2 byte values
                        case DW_FORM_data2      :
                        case DW_FORM_ref2       :
                            form_size = 2;
                            break;

                        // 4 byte values
                        case DW_FORM_strp       :
//                            switch (attr)
//                            {
//                            case DW_AT_name:
//                                m_name = debug_str_data.PeekCStr(debug_info_data.GetU32(&offset));
//                                break;
//                            case DW_AT_MIPS_linkage_name:
//                                m_linkage_name = debug_str_data.PeekCStr(debug_info_data.GetU32(&offset));
//                                break;
//
//                            default:
                                form_size = 4;
//                                break;
//                            }
                            break;

                        case DW_FORM_data4      :
                        case DW_FORM_ref4       :
                            form_size = 4;
                            break;

                        // 8 byte values
                        case DW_FORM_data8      :
                        case DW_FORM_ref8       :
                            form_size = 8;
                            break;

                        // signed or unsigned LEB 128 values
                    //  case DW_FORM_APPLE_db_str:
                        case DW_FORM_sdata      :
                        case DW_FORM_udata      :
                        case DW_FORM_ref_udata  :
                            debug_info_data.Skip_LEB128(&offset);
                            break;

                        case DW_FORM_indirect   :
                            form = debug_info_data.GetULEB128(&offset);
                            goto die_extract_indirect_form;

                        default:
                            *offset_ptr = offset;
                            return false;
                        }

                        offset += form_size;
                    }
                }
                *offset_ptr = offset;
                return true;
            }
        }
        else
        {
            m_abbrevDecl = NULL;
            *offset_ptr = offset;
            return true;    // NULL debug tag entry
        }
    }

    return false;
}

//----------------------------------------------------------------------
// AppendDependentDIES()
//----------------------------------------------------------------------
bool
DWARFDebugInfoEntry::AppendDependentDIES
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const bool add_children,
    DWARFDIECollection& dependent_dies
) const
{
    // Add this object's DIE offset
    // The line below is the only place that should add a die to the
    // dependent_dies collection as we have to be careful of recursion!
    if ( !dependent_dies.Insert(this) )
        return false;   // This DIE already exists in the collection, nothing to do!

    //DEBUG_PRINTF("    dependent_dies.Insert(0x%8.8x)\n", GetOffset());///

    if (m_abbrevDecl)
    {
        // Keep adding parent DIE offsets as long as the offsets do not
        // already exist in the collection
        const DWARFDebugInfoEntry* die = GetParent();
        while ( die && die->AppendDependentDIES(dwarf2Data, cu, false, dependent_dies) )
            die = die->GetParent();

        bool add_non_subprogram_children = false;
        bool add_children_override = false;

        if (!add_children)
        {
            switch (m_abbrevDecl->Tag())
            {
            case DW_TAG_array_type:                                             break;
            case DW_TAG_class_type:         add_non_subprogram_children = true; break;
            case DW_TAG_entry_point:                                            break;
            case DW_TAG_enumeration_type:                                       break;
            case DW_TAG_formal_parameter:                                       break;
            case DW_TAG_imported_declaration:                                   break;
            case DW_TAG_label:                                                  break;
            case DW_TAG_lexical_block:      add_children_override = true;       break;
            case DW_TAG_member:                                                 break;
            case DW_TAG_pointer_type:                                           break;
            case DW_TAG_reference_type:                                         break;
            case DW_TAG_compile_unit:                                           break;
            case DW_TAG_string_type:                                            break;
            case DW_TAG_structure_type:     add_non_subprogram_children = true; break;
            case DW_TAG_subroutine_type:    add_children_override = true;       break;
            case DW_TAG_typedef:                                                break;
            case DW_TAG_union_type:         add_non_subprogram_children = true; break;
            case DW_TAG_unspecified_parameters:                                 break;
            case DW_TAG_variant:                                                break;
            case DW_TAG_common_block:                                           break;
            case DW_TAG_common_inclusion:                                       break;
            case DW_TAG_inheritance:                                            break;
            case DW_TAG_inlined_subroutine:                                     break;
            case DW_TAG_module:                                                 break;
            case DW_TAG_ptr_to_member_type:                                     break;
            case DW_TAG_set_type:                                               break;
            case DW_TAG_subrange_type:                                          break;
            case DW_TAG_with_stmt:                                              break;
            case DW_TAG_access_declaration:                                     break;
            case DW_TAG_base_type:                                              break;
            case DW_TAG_catch_block:                                            break;
            case DW_TAG_const_type:                                             break;
            case DW_TAG_constant:                                               break;
            case DW_TAG_enumerator:                                             break;
            case DW_TAG_file_type:                                              break;
            case DW_TAG_friend:                                                 break;
            case DW_TAG_namelist:                                               break;
            case DW_TAG_namelist_item:                                          break;
            case DW_TAG_packed_type:                                            break;
            case DW_TAG_subprogram:             add_children_override = true;   break;
            case DW_TAG_template_type_parameter:                                break;
            case DW_TAG_template_value_parameter:                               break;
            case DW_TAG_thrown_type:                                            break;
            case DW_TAG_try_block:                                              break;
            case DW_TAG_variant_part:                                           break;
            case DW_TAG_variable:                                               break;
            case DW_TAG_volatile_type:                                          break;
            case DW_TAG_dwarf_procedure:                                        break;
            case DW_TAG_restrict_type:                                          break;
            case DW_TAG_interface_type:                                         break;
            case DW_TAG_namespace:                                              break;
            case DW_TAG_imported_module:                                        break;
            case DW_TAG_unspecified_type:                                       break;
            case DW_TAG_partial_unit:                                           break;
            case DW_TAG_imported_unit:                                          break;
            case DW_TAG_shared_type:                                            break;
            }
        }
        const DataExtractor& debug_info_data = dwarf2Data->get_debug_info_data();

        // Dump all data in the .debug_info for the attributes
        const uint32_t numAttributes = m_abbrevDecl->NumAttributes();
        uint32_t i;
        dw_offset_t offset = GetOffset();
        debug_info_data.Skip_LEB128(&offset);   // Skip abbreviation code

        dw_attr_t attr;
        dw_form_t form;
        for (i=0; i<numAttributes; ++i)
        {
            m_abbrevDecl->GetAttrAndFormByIndexUnchecked(i, attr, form);
            DWARFFormValue form_value(form);

            switch (attr)
            {
            // All cases that use refer to another DIE should use this case
            // without
            // having to check the FORM of the attribute to tell if it refers to another
            // DIE
            case DW_AT_abstract_origin:
            case DW_AT_import:
            case DW_AT_discr:
            case DW_AT_containing_type:
            case DW_AT_base_types:
            case DW_AT_friend:
            case DW_AT_specification:
            case DW_AT_type:
            case DW_AT_common_reference:
            case DW_AT_default_value:
                {
                    form_value.ExtractValue(debug_info_data, &offset, cu);
                    DWARFCompileUnitSP cu_sp_ptr;
                    const DWARFDebugInfoEntry* ref_die = const_cast<SymbolFileDWARF*>(dwarf2Data)->DebugInfo()->GetDIEPtr(form_value.Reference(cu), &cu_sp_ptr);
                    if (ref_die)
                        ref_die->AppendDependentDIES(dwarf2Data, cu_sp_ptr.get(), true, dependent_dies);
                }
                break;

            default:
                if (attr != DW_AT_sibling)
                {
                    switch (form_value.Form())
                    {
                    case DW_FORM_ref_addr:
                    case DW_FORM_ref1:
                    case DW_FORM_ref2:
                    case DW_FORM_ref4:
                    case DW_FORM_ref8:
                    case DW_FORM_ref_udata:
//                      Log::WarningVerbose("DWARFDebugInfoEntry::AppendDependentDIES() -- check on this item %s: attr = %s  form = %s",
//                          DW_TAG_value_to_name(m_abbrevDecl->Tag()),
//                          DW_AT_value_to_name(attr),
//                          DW_FORM_value_to_name(form));
                        break;
                    }
                }
                form_value.SkipValue(debug_info_data, &offset, cu);
                break;
            }
        }

        if (m_abbrevDecl->HasChildren())
        {
            const DWARFDebugInfoEntry* child;
            for (child = GetFirstChild(); child != NULL; child = child->GetSibling())
            {
                bool add = add_children || add_children_override;

                if (!add)
                {
                    if (add_non_subprogram_children)
                    {
                        // add_non_subprogram_children is used for classes and structs
                        // that may contain children that are the member variables that
                        // may have functions as children and whom may add the class or
                        // struct by adding their parent. We don't want to add any
                        // functions though since they may have been optimized out. But
                        // we do need to watch for declarations and keep them.
                        if (child->Tag() == DW_TAG_subprogram)
                        {
                            // Check if this subprogram TAG had a DW_AT_declaration attribute set to 1.
                            // If so we need to include this DIE so that we always have a complete view
                            // of a class definition so debuggers can track down any weak symbols that
                            // may not have had weak definition entries.
                            if (child->GetAttributeValueAsUnsigned(dwarf2Data, cu, DW_AT_declaration, 0) == 1)
                                add = true;
                        }
                        else
                        {
                            // Add all other items inside a class/struct
                            add = true;
                        }
                    }
                    else
                    {
                        // We don't need to add this child, only add it if it's a NULL tag
                        add = child->IsNULL();
                    }
                }

                if (add)
                    child->AppendDependentDIES(dwarf2Data, cu, true, dependent_dies);
            }
        }
    }
    return true;
}

//----------------------------------------------------------------------
// DumpAncestry
//
// Dumps all of a debug information entries parents up until oldest and
// all of it's attributes to the specified stream.
//----------------------------------------------------------------------
void
DWARFDebugInfoEntry::DumpAncestry
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const DWARFDebugInfoEntry* oldest,
    Stream *s,
    uint32_t recurse_depth
) const
{
    const DWARFDebugInfoEntry* parent = GetParent();
    if (parent && parent != oldest)
        parent->DumpAncestry(dwarf2Data, cu, oldest, s, 0);
    Dump(dwarf2Data, cu, s, recurse_depth);
}

//----------------------------------------------------------------------
// Compare two DIE by comparing all their attributes values, and
// following all DW_FORM_ref attributes and comparing their contents as
// well (except for DW_AT_sibling attributes.
//
//  DWARFDebugInfoEntry::CompareState compare_state;
//  int result = DWARFDebugInfoEntry::Compare(this, 0x00017ccb, 0x0001eb2b, compare_state, false, true);
//----------------------------------------------------------------------
int
DWARFDebugInfoEntry::Compare
(
    SymbolFileDWARF* dwarf2Data,
    dw_offset_t a_die_offset,
    dw_offset_t b_die_offset,
    CompareState &compare_state,
    bool compare_siblings,
    bool compare_children
)
{
    if (a_die_offset == b_die_offset)
        return 0;

    DWARFCompileUnitSP a_cu_sp;
    DWARFCompileUnitSP b_cu_sp;
    const DWARFDebugInfoEntry* a_die = dwarf2Data->DebugInfo()->GetDIEPtr(a_die_offset, &a_cu_sp);
    const DWARFDebugInfoEntry* b_die = dwarf2Data->DebugInfo()->GetDIEPtr(b_die_offset, &b_cu_sp);

    return Compare(dwarf2Data, a_cu_sp.get(), a_die, b_cu_sp.get(), b_die, compare_state, compare_siblings, compare_children);
}

int
DWARFDebugInfoEntry::Compare
(
    SymbolFileDWARF* dwarf2Data,
    DWARFCompileUnit* a_cu, const DWARFDebugInfoEntry* a_die,
    DWARFCompileUnit* b_cu, const DWARFDebugInfoEntry* b_die,
    CompareState &compare_state,
    bool compare_siblings,
    bool compare_children
)
{
    if (a_die == b_die)
        return 0;

    if (!compare_state.AddTypePair(a_die->GetOffset(), b_die->GetOffset()))
    {
        // We are already comparing both of these types, so let
        // compares complete for the real result
        return 0;
    }

    //printf("DWARFDebugInfoEntry::Compare(0x%8.8x, 0x%8.8x)\n", a_die->GetOffset(), b_die->GetOffset());

    // Do we have two valid DIEs?
    if (a_die && b_die)
    {
        // Both DIE are valid
        int result = 0;

        const dw_tag_t a_tag = a_die->Tag();
        const dw_tag_t b_tag = b_die->Tag();
        if (a_tag == 0 && b_tag == 0)
            return 0;

        //printf("    comparing tags: %s and %s\n", DW_TAG_value_to_name(a_tag), DW_TAG_value_to_name(b_tag));

        if (a_tag < b_tag)
            return -1;
        else if (a_tag > b_tag)
            return 1;

        DWARFDebugInfoEntry::Attributes a_attrs;
        DWARFDebugInfoEntry::Attributes b_attrs;
        size_t a_attr_count = a_die->GetAttributes(dwarf2Data, a_cu, a_attrs);
        size_t b_attr_count = b_die->GetAttributes(dwarf2Data, b_cu, b_attrs);
        if (a_attr_count != b_attr_count)
        {
            a_attrs.RemoveAttribute(DW_AT_sibling);
            b_attrs.RemoveAttribute(DW_AT_sibling);
        }

        a_attr_count = a_attrs.Size();
        b_attr_count = b_attrs.Size();

        DWARFFormValue a_form_value;
        DWARFFormValue b_form_value;

        if (a_attr_count != b_attr_count)
        {
            uint32_t is_decl_index = a_attrs.FindAttributeIndex(DW_AT_declaration);
            uint32_t a_name_index = UINT_MAX;
            uint32_t b_name_index = UINT_MAX;
            if (is_decl_index != UINT_MAX)
            {
                if (a_attr_count == 2)
                {
                    a_name_index = a_attrs.FindAttributeIndex(DW_AT_name);
                    b_name_index = b_attrs.FindAttributeIndex(DW_AT_name);
                }
            }
            else
            {
                is_decl_index = b_attrs.FindAttributeIndex(DW_AT_declaration);
                if (is_decl_index != UINT_MAX && a_attr_count == 2)
                {
                    a_name_index = a_attrs.FindAttributeIndex(DW_AT_name);
                    b_name_index = b_attrs.FindAttributeIndex(DW_AT_name);
                }
            }
            if (a_name_index != UINT_MAX && b_name_index != UINT_MAX)
            {
                if (a_attrs.ExtractFormValueAtIndex(dwarf2Data, a_name_index, a_form_value) &&
                    b_attrs.ExtractFormValueAtIndex(dwarf2Data, b_name_index, b_form_value))
                {
                    result = DWARFFormValue::Compare (a_form_value, b_form_value, a_cu, b_cu, &dwarf2Data->get_debug_str_data());
                    if (result == 0)
                    {
                        a_attr_count = b_attr_count = 0;
                        compare_children = false;
                    }
                }
            }
        }

        if (a_attr_count < b_attr_count)
            return -1;
        if (a_attr_count > b_attr_count)
            return 1;


        // The number of attributes are the same...
        if (a_attr_count > 0)
        {
            const DataExtractor* debug_str_data_ptr = &dwarf2Data->get_debug_str_data();

            uint32_t i;
            for (i=0; i<a_attr_count; ++i)
            {
                const dw_attr_t a_attr = a_attrs.AttributeAtIndex(i);
                const dw_attr_t b_attr = b_attrs.AttributeAtIndex(i);
                //printf("    comparing attributes\n\t\t0x%8.8x: %s %s\t\t0x%8.8x: %s %s\n",
                //                a_attrs.DIEOffsetAtIndex(i), DW_FORM_value_to_name(a_attrs.FormAtIndex(i)), DW_AT_value_to_name(a_attr),
                //                b_attrs.DIEOffsetAtIndex(i), DW_FORM_value_to_name(b_attrs.FormAtIndex(i)), DW_AT_value_to_name(b_attr));

                if (a_attr < b_attr)
                    return -1;
                else if (a_attr > b_attr)
                    return 1;

                switch (a_attr)
                {
                // Since we call a form of GetAttributes which inlines the
                // attributes from DW_AT_abstract_origin and DW_AT_specification
                // we don't care if their values mismatch...
                case DW_AT_abstract_origin:
                case DW_AT_specification:
                case DW_AT_sibling:
                case DW_AT_containing_type:
                    //printf("        action = IGNORE\n");
                    result = 0;
                    break;  // ignore

                default:
                    if (a_attrs.ExtractFormValueAtIndex(dwarf2Data, i, a_form_value) &&
                        b_attrs.ExtractFormValueAtIndex(dwarf2Data, i, b_form_value))
                        result = DWARFFormValue::Compare (a_form_value, b_form_value, a_cu, b_cu, debug_str_data_ptr);
                    break;
                }

                //printf("\t  result = %i\n", result);

                if (result != 0)
                {
                    // Attributes weren't equal, lets see if we care?
                    switch (a_attr)
                    {
                    case DW_AT_decl_file:
                        // TODO: add the ability to compare files in two different compile units
                        if (a_cu == b_cu)
                        {
                            //printf("        action = RETURN RESULT\n");
                            return result;  // Only return the compare results when the compile units are the same and the decl_file attributes can be compared
                        }
                        else
                        {
                            result = 0;
                            //printf("        action = IGNORE\n");
                        }
                        break;

                    default:
                        switch (a_attrs.FormAtIndex(i))
                        {
                        case DW_FORM_ref1:
                        case DW_FORM_ref2:
                        case DW_FORM_ref4:
                        case DW_FORM_ref8:
                        case DW_FORM_ref_udata:
                        case DW_FORM_ref_addr:
                            //printf("    action = COMPARE DIEs 0x%8.8x 0x%8.8x\n", (dw_offset_t)a_form_value.Reference(a_cu), (dw_offset_t)b_form_value.Reference(b_cu));
                            // These attribute values refer to other DIEs, so lets compare those instead of their DIE offsets...
                            result = Compare(dwarf2Data, a_form_value.Reference(a_cu), b_form_value.Reference(b_cu), compare_state, false, true);
                            if (result != 0)
                                return result;
                            break;

                        default:
                            // We do care that they were different, return this result...
                            //printf("        action = RETURN RESULT\n");
                            return result;
                        }
                    }
                }
            }
        }
        //printf("    SUCCESS\n\t\t0x%8.8x: %s\n\t\t0x%8.8x: %s\n", a_die->GetOffset(), DW_TAG_value_to_name(a_tag), b_die->GetOffset(), DW_TAG_value_to_name(b_tag));

        if (compare_children)
        {
            bool a_has_children = a_die->HasChildren();
            bool b_has_children = b_die->HasChildren();
            if (a_has_children == b_has_children)
            {
                // Both either have kids or don't
                if (a_has_children)
                    result = Compare(   dwarf2Data,
                                        a_cu, a_die->GetFirstChild(),
                                        b_cu, b_die->GetFirstChild(),
                                        compare_state, true, compare_children);
                else
                    result = 0;
            }
            else if (!a_has_children)
                result = -1;    // A doesn't have kids, but B does
            else
                result = 1; // A has kids, but B doesn't
        }

        if (compare_siblings)
        {
            result = Compare(   dwarf2Data,
                                a_cu, a_die->GetSibling(),
                                b_cu, b_die->GetSibling(),
                                compare_state, true, compare_children);
        }

        return result;
    }

    if (a_die == NULL)
        return -1;  // a_die is NULL, yet b_die is non-NULL
    else
        return 1;   // a_die is non-NULL, yet b_die is NULL

}

//
//int
//DWARFDebugInfoEntry::Compare
//(
//  SymbolFileDWARF* dwarf2Data,
//  const DWARFCompileUnit* cu_a,
//  const DWARFDebugInfoEntry* die_a,
//  const DWARFCompileUnit* cu_a,
//  const DWARFDebugInfoEntry* die_b,
//  CompareState &compare_state
//)
//{
//}

//----------------------------------------------------------------------
// GetDIENamesAndRanges
//
// Gets the valid address ranges for a given DIE by looking for a
// DW_AT_low_pc/DW_AT_high_pc pair, DW_AT_entry_pc, or DW_AT_ranges
// attributes.
//----------------------------------------------------------------------
bool
DWARFDebugInfoEntry::GetDIENamesAndRanges
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const char * &name,
    const char * &mangled,
    DWARFDebugRanges::RangeList& ranges,
    int& decl_file,
    int& decl_line,
    int& decl_column,
    int& call_file,
    int& call_line,
    int& call_column,
    DWARFExpression *frame_base
) const
{
    if (dwarf2Data == NULL)
        return false;

    dw_addr_t lo_pc = DW_INVALID_ADDRESS;
    dw_addr_t hi_pc = DW_INVALID_ADDRESS;
    std::vector<dw_offset_t> die_offsets;
    if (m_abbrevDecl)
    {
        const DataExtractor& debug_info_data = dwarf2Data->get_debug_info_data();
        uint32_t offset = m_offset;

        if (!debug_info_data.ValidOffset(offset))
            return false;

        // Skip the abbreviation code
        debug_info_data.Skip_LEB128(&offset);

        const uint32_t numAttributes = m_abbrevDecl->NumAttributes();
        uint32_t i;
        dw_attr_t attr;
        dw_form_t form;
        for (i=0; i<numAttributes; ++i)
        {
            m_abbrevDecl->GetAttrAndFormByIndexUnchecked(i, attr, form);
            DWARFFormValue form_value(form);
            if (form_value.ExtractValue(debug_info_data, &offset, cu))
            {
                switch (attr)
                {
                case DW_AT_low_pc:
                case DW_AT_entry_pc:
                    lo_pc = form_value.Unsigned();
                    break;

                case DW_AT_high_pc:
                    hi_pc = form_value.Unsigned();
                    break;

                case DW_AT_ranges:
                    {
                        const DWARFDebugRanges* debug_ranges = dwarf2Data->DebugRanges();
                        debug_ranges->FindRanges(form_value.Unsigned(), ranges);
                        // All DW_AT_ranges are relative to the base address of the
                        // compile unit. We add the compile unit base address to make
                        // sure all the addresses are properly fixed up.
                        ranges.AddOffset(cu->GetBaseAddress());
                    }
                    break;

                case DW_AT_name:
                    if (name == NULL)
                        name = form_value.AsCString(&dwarf2Data->get_debug_str_data());
                    break;

                case DW_AT_MIPS_linkage_name:
                    if (mangled == NULL)
                        mangled = form_value.AsCString(&dwarf2Data->get_debug_str_data());
                    break;

                case DW_AT_abstract_origin:
                    die_offsets.push_back(form_value.Reference(cu));
                    break;

                case DW_AT_specification:
                    die_offsets.push_back(form_value.Reference(cu));
                    break;

                case DW_AT_decl_file:
                    if (decl_file == 0)
                        decl_file = form_value.Unsigned();
                    break;

                case DW_AT_decl_line:
                    if (decl_line == 0)
                        decl_line = form_value.Unsigned();
                    break;

                case DW_AT_decl_column:
                    if (decl_column == 0)
                        decl_column = form_value.Unsigned();
                    break;

                case DW_AT_call_file:
                    if (call_file == 0)
                        call_file = form_value.Unsigned();
                    break;

                case DW_AT_call_line:
                    if (call_line == 0)
                        call_line = form_value.Unsigned();
                    break;

                case DW_AT_call_column:
                    if (call_column == 0)
                        call_column = form_value.Unsigned();
                    break;

                case DW_AT_frame_base:
                    if (frame_base)
                    {
                        if (form_value.BlockData())
                        {
                            uint32_t block_offset = form_value.BlockData() - debug_info_data.GetDataStart();
                            uint32_t block_length = form_value.Unsigned();
                            frame_base->SetOpcodeData(debug_info_data, block_offset, block_length, NULL);
                        }
                        else
                        {
                            const DataExtractor&    debug_loc_data = dwarf2Data->get_debug_loc_data();
                            const dw_offset_t debug_loc_offset = form_value.Unsigned();

                            size_t loc_list_length = DWARFLocationList::Size(debug_loc_data, debug_loc_offset);
                            if (loc_list_length > 0)
                            {
                                Address base_address(cu->GetBaseAddress(), dwarf2Data->GetObjectFile()->GetSectionList());
                                frame_base->SetOpcodeData(debug_loc_data, debug_loc_offset, loc_list_length, &base_address);
                            }
                        }
                    }
                    break;

                default:
                    break;
                }
            }
        }
    }

    size_t numRanges = ranges.Size();

    if (numRanges == 0)
    {
        if (lo_pc != DW_INVALID_ADDRESS)
        {
            if (hi_pc != DW_INVALID_ADDRESS)
                ranges.AddRange(lo_pc, hi_pc);
            else
                ranges.AddRange(lo_pc, lo_pc);
        }
    }

    if (ranges.Size() == 0 || (name == NULL) || (mangled == NULL))
    {
        std::vector<dw_offset_t>::const_iterator pos;
        std::vector<dw_offset_t>::const_iterator end = die_offsets.end();
        for (pos = die_offsets.begin(); pos != end; ++pos)
        {
            DWARFCompileUnitSP cu_sp_ptr;
            const DWARFDebugInfoEntry* die = NULL;
            dw_offset_t die_offset = *pos;
            if (die_offset != DW_INVALID_OFFSET)
            {
                die = dwarf2Data->DebugInfo()->GetDIEPtr(die_offset, &cu_sp_ptr);
                if (die)
                    die->GetDIENamesAndRanges(dwarf2Data, cu_sp_ptr.get(), name, mangled, ranges, decl_file, decl_line, decl_column, call_file, call_line, call_column);
            }
        }
    }
    return ranges.Size() > 0;
}

//----------------------------------------------------------------------
// Dump
//
// Dumps a debug information entry and all of it's attributes to the
// specified stream.
//----------------------------------------------------------------------
void
DWARFDebugInfoEntry::Dump
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    Stream *s,
    uint32_t recurse_depth
) const
{
    const DataExtractor& debug_info_data = dwarf2Data->get_debug_info_data();
    uint32_t offset = m_offset;
    bool english    = s->GetFlags().IsSet (DWARFDebugInfo::eDumpFlag_EnglishyNames);

    if (debug_info_data.ValidOffset(offset))
    {
        dw_uleb128_t abbrCode = debug_info_data.GetULEB128(&offset);

        s->Printf("\n0x%8.8x: ", m_offset);
        s->Indent();
        if (abbrCode)
        {
            if (m_abbrevDecl)
            {
                if (english)
                    s->PutCString(DW_TAG_value_to_englishy_name(m_abbrevDecl->Tag()));
                else
                    s->PutCString(DW_TAG_value_to_name(m_abbrevDecl->Tag()));
                s->Printf( " [%u] %c\n", abbrCode, m_abbrevDecl->HasChildren() ? '*':' ');

                // Dump all data in the .debug_info for the attributes
                const uint32_t numAttributes = m_abbrevDecl->NumAttributes();
                uint32_t i;
                dw_attr_t attr;
                dw_form_t form;
                for (i=0; i<numAttributes; ++i)
                {
                    m_abbrevDecl->GetAttrAndFormByIndexUnchecked(i, attr, form);

                    DumpAttribute(dwarf2Data, cu, debug_info_data, &offset, s, attr, form);
                }

                const DWARFDebugInfoEntry* child = GetFirstChild();
                if (recurse_depth > 0 && child)
                {
                    s->IndentMore();

                    while (child)
                    {
                        child->Dump(dwarf2Data, cu, s, recurse_depth-1);
                        child = child->GetSibling();
                    }
                    s->IndentLess();
                }
            }
            else
                s->Printf( "Abbreviation code note found in 'debug_abbrev' class for code: %u\n", abbrCode);
        }
        else
        {
            s->Printf( "NULL\n");
        }
    }
}

//----------------------------------------------------------------------
// DumpAttribute
//
// Dumps a debug information entry attribute along with it's form. Any
// special display of attributes is done (disassemble location lists,
// show enumeration values for attributes, etc).
//----------------------------------------------------------------------
void
DWARFDebugInfoEntry::DumpAttribute
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const DataExtractor& debug_info_data,
    uint32_t* offset_ptr,
    Stream *s,
    dw_attr_t attr,
    dw_form_t form
)
{
    bool verbose    = s->GetVerbose();
    bool show_form  = s->GetFlags().IsSet(DWARFDebugInfo::eDumpFlag_ShowForm);
    bool english    = s->GetFlags().IsSet(DWARFDebugInfo::eDumpFlag_EnglishyNames);
    const DataExtractor* debug_str_data = dwarf2Data ? &dwarf2Data->get_debug_str_data() : NULL;
    if (verbose)
        s->Offset(*offset_ptr);
    else
        s->Printf( "            ");
    s->Indent();

    if (english)
        s->PutCString(DW_AT_value_to_englishy_name(attr));
    else
        s->PutCString(DW_AT_value_to_name(attr));

    if (show_form)
    {
        s->Printf( "[%s", english ? DW_FORM_value_to_englishy_name(form) : DW_FORM_value_to_name(form));
    }

    DWARFFormValue form_value(form);

    if (!form_value.ExtractValue(debug_info_data, offset_ptr, cu))
        return;

    if (show_form)
    {
        if (form == DW_FORM_indirect)
        {
            s->Printf( " [%s]", english ? DW_FORM_value_to_englishy_name(form_value.Form()) : DW_FORM_value_to_name(form_value.Form()));
        }

        s->PutCString("] ");
    }

    s->PutCString("( ");

    // Always dump form value if verbose is enabled
    if (verbose)
    {
        form_value.Dump(s, debug_str_data, cu);
    }


    // Check to see if we have any special attribute formatters
    switch (attr)
    {
    case DW_AT_stmt_list:
        if ( verbose ) s->PutCString(" ( ");
        s->Printf( "0x%8.8x", form_value.Unsigned());
        if ( verbose ) s->PutCString(" )");
        break;

    case DW_AT_language:
        if ( verbose ) s->PutCString(" ( ");
        s->PutCString(DW_LANG_value_to_name(form_value.Unsigned()));
        if ( verbose ) s->PutCString(" )");
        break;

    case DW_AT_encoding:
        if ( verbose ) s->PutCString(" ( ");
        s->PutCString(DW_ATE_value_to_name(form_value.Unsigned()));
        if ( verbose ) s->PutCString(" )");
        break;

    case DW_AT_frame_base:
    case DW_AT_location:
    case DW_AT_data_member_location:
        {
            const uint8_t* blockData = form_value.BlockData();
            if (blockData)
            {
                if (!verbose)
                    form_value.Dump(s, debug_str_data, cu);

                // Location description is inlined in data in the form value
                DataExtractor locationData(debug_info_data, (*offset_ptr) - form_value.Unsigned(), form_value.Unsigned());
                if ( verbose ) s->PutCString(" ( ");
                print_dwarf_expression (s, locationData, DWARFCompileUnit::GetAddressByteSize(cu), 4, false);
                if ( verbose ) s->PutCString(" )");
            }
            else
            {
                // We have a location list offset as the value that is
                // the offset into the .debug_loc section that describes
                // the value over it's lifetime
                uint64_t debug_loc_offset = form_value.Unsigned();
                if (dwarf2Data)
                {
                    if ( !verbose )
                        form_value.Dump(s, debug_str_data, cu);
                    DWARFLocationList::Dump(s, cu, dwarf2Data->get_debug_loc_data(), debug_loc_offset);
                }
                else
                {
                    if ( !verbose )
                        form_value.Dump(s, NULL, cu);
                }
            }
        }
        break;

    case DW_AT_abstract_origin:
    case DW_AT_specification:
        {
            uint64_t abstract_die_offset = form_value.Reference(cu);
            form_value.Dump(s, debug_str_data, cu);
        //  *ostrm_ptr << HEX32 << abstract_die_offset << " ( ";
            if ( verbose ) s->PutCString(" ( ");
            GetName(dwarf2Data, cu, abstract_die_offset, s);
            if ( verbose ) s->PutCString(" )");
        }
        break;

    case DW_AT_type:
        {
            uint64_t type_die_offset = form_value.Reference(cu);
            if (!verbose)
                form_value.Dump(s, debug_str_data, cu);
            s->PutCString(" ( ");
            AppendTypeName(dwarf2Data, cu, type_die_offset, s);
            s->PutCString(" )");
        }
        break;

    case DW_AT_ranges:
        {
            if ( !verbose )
                form_value.Dump(s, debug_str_data, cu);
            uint32_t ranges_offset = form_value.Unsigned();
            dw_addr_t base_addr = cu ? cu->GetBaseAddress() : 0;
            DWARFDebugRanges::Dump(s, dwarf2Data->get_debug_ranges_data(), &ranges_offset, base_addr);
        }
        break;

    default:
        if ( !verbose )
            form_value.Dump(s, debug_str_data, cu);
        break;
    }

    s->PutCString(" )\n");
}

//----------------------------------------------------------------------
// Get all attribute values for a given DIE, including following any
// specification or abstract origin attributes and including those in
// the results. Any duplicate attributes will have the first instance
// take precedence (this can happen for declaration attributes).
//----------------------------------------------------------------------
size_t
DWARFDebugInfoEntry::GetAttributes
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    DWARFDebugInfoEntry::Attributes& attributes
) const
{
    if (m_abbrevDecl)
    {
        uint32_t offset = GetOffset();
        const DataExtractor& debug_info_data = dwarf2Data->get_debug_info_data();

        // Skip the abbreviation code so we are at the data for the attributes
        debug_info_data.Skip_LEB128(&offset);

        const uint32_t num_attributes = m_abbrevDecl->NumAttributes();
        uint32_t i;
        dw_attr_t attr;
        dw_form_t form;
        DWARFFormValue form_value;
        for (i=0; i<num_attributes; ++i)
        {
            m_abbrevDecl->GetAttrAndFormByIndexUnchecked (i, attr, form);
            attributes.Append(cu, offset, attr, form);
            if ((attr == DW_AT_specification) || (attr == DW_AT_abstract_origin))
            {
                form_value.SetForm(form);
                if (form_value.ExtractValue(debug_info_data, &offset, cu))
                {
                    const DWARFDebugInfoEntry* die = NULL;
                    dw_offset_t die_offset = form_value.Reference(cu);
                    if (cu->ContainsDIEOffset(die_offset))
                    {
                        die = const_cast<DWARFCompileUnit*>(cu)->GetDIEPtr(die_offset);
                        if (die)
                            die->GetAttributes(dwarf2Data, cu, attributes);
                    }
                    else
                    {
                        DWARFCompileUnitSP cu_sp_ptr;
                        die = const_cast<SymbolFileDWARF*>(dwarf2Data)->DebugInfo()->GetDIEPtr(die_offset, &cu_sp_ptr);
                        if (die)
                            die->GetAttributes(dwarf2Data, cu_sp_ptr.get(), attributes);
                    }
                }
            }
            else
            {
                assert(DWARFFormValue::SkipValue(form, debug_info_data, &offset, cu));
            }
        }
    }
    else
    {
        attributes.Clear();
    }
    return attributes.Size();

}

//----------------------------------------------------------------------
// GetAttributeValue
//
// Get the value of an attribute and return the .debug_info offset of the
// attribute if it was properly extracted into form_value, or zero
// if we fail since an offset of zero is invalid for an attribute (it
// would be a compile unit header).
//----------------------------------------------------------------------
dw_offset_t
DWARFDebugInfoEntry::GetAttributeValue
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const dw_attr_t attr,
    DWARFFormValue& form_value,
    dw_offset_t* end_attr_offset_ptr
) const
{
    if (m_abbrevDecl)
    {
        uint32_t attr_idx = m_abbrevDecl->FindAttributeIndex(attr);

        if (attr_idx != DW_INVALID_INDEX)
        {
            uint32_t offset = GetOffset();

            const DataExtractor& debug_info_data = dwarf2Data->get_debug_info_data();

            // Skip the abbreviation code so we are at the data for the attributes
            debug_info_data.Skip_LEB128(&offset);

            uint32_t idx=0;
            while (idx<attr_idx)
                DWARFFormValue::SkipValue(m_abbrevDecl->GetFormByIndex(idx++), debug_info_data, &offset, cu);

            const dw_offset_t attr_offset = offset;
            form_value.SetForm(m_abbrevDecl->GetFormByIndex(idx));
            if (form_value.ExtractValue(debug_info_data, &offset, cu))
            {
                if (end_attr_offset_ptr)
                    *end_attr_offset_ptr = offset;
                return attr_offset;
            }
        }
    }

    return 0;
}

//----------------------------------------------------------------------
// GetAttributeValueAsString
//
// Get the value of an attribute as a string return it. The resulting
// pointer to the string data exists within the supplied SymbolFileDWARF
// and will only be available as long as the SymbolFileDWARF is still around
// and it's content doesn't change.
//----------------------------------------------------------------------
const char*
DWARFDebugInfoEntry::GetAttributeValueAsString
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const dw_attr_t attr,
    const char* fail_value) const
{
    DWARFFormValue form_value;
    if (GetAttributeValue(dwarf2Data, cu, attr, form_value))
        return form_value.AsCString(&dwarf2Data->get_debug_str_data());
    return fail_value;
}

//----------------------------------------------------------------------
// GetAttributeValueAsUnsigned
//
// Get the value of an attribute as unsigned and return it.
//----------------------------------------------------------------------
uint64_t
DWARFDebugInfoEntry::GetAttributeValueAsUnsigned
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const dw_attr_t attr,
    uint64_t fail_value
) const
{
    DWARFFormValue form_value;
    if (GetAttributeValue(dwarf2Data, cu, attr, form_value))
        return form_value.Unsigned();
    return fail_value;
}

//----------------------------------------------------------------------
// GetAttributeValueAsSigned
//
// Get the value of an attribute a signed value and return it.
//----------------------------------------------------------------------
int64_t
DWARFDebugInfoEntry::GetAttributeValueAsSigned
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const dw_attr_t attr,
    int64_t fail_value
) const
{
    DWARFFormValue form_value;
    if (GetAttributeValue(dwarf2Data, cu, attr, form_value))
        return form_value.Signed();
    return fail_value;
}

//----------------------------------------------------------------------
// GetAttributeValueAsReference
//
// Get the value of an attribute as reference and fix up and compile
// unit relative offsets as needed.
//----------------------------------------------------------------------
uint64_t
DWARFDebugInfoEntry::GetAttributeValueAsReference
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const dw_attr_t attr,
    uint64_t fail_value
) const
{
    DWARFFormValue form_value;
    if (GetAttributeValue(dwarf2Data, cu, attr, form_value))
        return form_value.Reference(cu);
    return fail_value;
}

//----------------------------------------------------------------------
// GetAttributeValueAsLocation
//
// Get the value of an attribute as reference and fix up and compile
// unit relative offsets as needed.
//----------------------------------------------------------------------
dw_offset_t
DWARFDebugInfoEntry::GetAttributeValueAsLocation
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const dw_attr_t attr,
    DataExtractor& location_data,
    uint32_t &block_size
) const
{
    block_size = 0;
    DWARFFormValue form_value;

    // Empty out data in case we don't find anything
    location_data.Clear();
    dw_offset_t end_addr_offset = DW_INVALID_OFFSET;
    const dw_offset_t attr_offset = GetAttributeValue(dwarf2Data, cu, attr, form_value, &end_addr_offset);
    if (attr_offset)
    {
        const uint8_t* blockData = form_value.BlockData();
        if (blockData)
        {
            // We have an inlined location list in the .debug_info section
            const DataExtractor& debug_info = dwarf2Data->get_debug_info_data();
            dw_offset_t block_offset = blockData - debug_info.GetDataStart();
            block_size = (end_addr_offset - attr_offset) - form_value.Unsigned();
            location_data.SetData(debug_info, block_offset, block_size);
        }
        else
        {
            // We have a location list offset as the value that is
            // the offset into the .debug_loc section that describes
            // the value over it's lifetime
            dw_offset_t debug_loc_offset = form_value.Unsigned();
            if (dwarf2Data)
            {
                assert(dwarf2Data->get_debug_loc_data().GetAddressByteSize() == cu->GetAddressByteSize());
                return DWARFLocationList::Extract(dwarf2Data->get_debug_loc_data(), &debug_loc_offset, location_data);
            }
        }
    }
    return attr_offset;
}

//----------------------------------------------------------------------
// GetName
//
// Get value of the DW_AT_name attribute and return it if one exists,
// else return NULL.
//----------------------------------------------------------------------
const char*
DWARFDebugInfoEntry::GetName
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu
) const
{
    DWARFFormValue form_value;
    if (GetAttributeValue(dwarf2Data, cu, DW_AT_name, form_value))
        return form_value.AsCString(&dwarf2Data->get_debug_str_data());
    return NULL;
}


//----------------------------------------------------------------------
// GetMangledName
//
// Get value of the DW_AT_MIPS_linkage_name attribute and return it if
// one exists, else return the value of the DW_AT_name attribute
//----------------------------------------------------------------------
const char*
DWARFDebugInfoEntry::GetMangledName
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    bool substitute_name_allowed
) const
{
    const char* name = NULL;
    DWARFFormValue form_value;

    if (GetAttributeValue(dwarf2Data, cu, DW_AT_MIPS_linkage_name, form_value))
        name = form_value.AsCString(&dwarf2Data->get_debug_str_data());

    if (substitute_name_allowed && name == NULL)
    {
        if (GetAttributeValue(dwarf2Data, cu, DW_AT_name, form_value))
            name = form_value.AsCString(&dwarf2Data->get_debug_str_data());
    }
    return name;
}


//----------------------------------------------------------------------
// GetPubname
//
// Get value the name for a DIE as it should appear for a
// .debug_pubnames or .debug_pubtypes section.
//----------------------------------------------------------------------
const char*
DWARFDebugInfoEntry::GetPubname
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu
) const
{
    const char* name = NULL;
    DWARFFormValue form_value;

    if (GetAttributeValue(dwarf2Data, cu, DW_AT_MIPS_linkage_name, form_value))
        name = form_value.AsCString(&dwarf2Data->get_debug_str_data());
    else if (GetAttributeValue(dwarf2Data, cu, DW_AT_name, form_value))
        name = form_value.AsCString(&dwarf2Data->get_debug_str_data());
    else if (GetAttributeValue(dwarf2Data, cu, DW_AT_specification, form_value))
    {
        // The specification DIE may be in another compile unit so we need
        // to get a die and its compile unit.
        DWARFCompileUnitSP cu_sp_ptr;
        const DWARFDebugInfoEntry* die = const_cast<SymbolFileDWARF*>(dwarf2Data)->DebugInfo()->GetDIEPtr(form_value.Reference(cu), &cu_sp_ptr);
        if (die)
            return die->GetPubname(dwarf2Data, cu_sp_ptr.get());
    }
    return name;
}


//----------------------------------------------------------------------
// GetName
//
// Get value of the DW_AT_name attribute for a debug information entry
// that exists at offset "die_offset" and place that value into the
// supplied stream object. If the DIE is a NULL object "NULL" is placed
// into the stream, and if no DW_AT_name attribute exists for the DIE
// then nothing is printed.
//----------------------------------------------------------------------
bool
DWARFDebugInfoEntry::GetName
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const uint32_t die_offset,
    Stream *s
)
{
    DWARFDebugInfoEntry die;
    uint32_t offset = die_offset;
    if (die.Extract(dwarf2Data, cu, &offset))
    {
        if (die.IsNULL())
        {
            s->PutCString("NULL");
            return true;
        }
        else
        {
            DWARFFormValue form_value;
            if (die.GetAttributeValue(dwarf2Data, cu, DW_AT_name, form_value))
            {
                const char* name = form_value.AsCString(&dwarf2Data->get_debug_str_data());
                if (name)
                {
                    s->PutCString(name);
                    return true;
                }
            }
        }
    }
    return false;
}

//----------------------------------------------------------------------
// AppendTypeName
//
// Follows the type name definition down through all needed tags to
// end up with a fully qualified type name and dump the results to
// the supplied stream. This is used to show the name of types given
// a type identifier.
//----------------------------------------------------------------------
bool
DWARFDebugInfoEntry::AppendTypeName
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    const uint32_t die_offset,
    Stream *s
)
{
    DWARFDebugInfoEntry die;
    uint32_t offset = die_offset;
    if (die.Extract(dwarf2Data, cu, &offset))
    {
        if (die.IsNULL())
        {
            s->PutCString("NULL");
            return true;
        }
        else
        {
            const char* name = die.GetPubname(dwarf2Data, cu);
        //  if (die.GetAttributeValue(dwarf2Data, cu, DW_AT_name, form_value))
        //      name = form_value.AsCString(&dwarf2Data->get_debug_str_data());
            if (name)
                s->PutCString(name);
            else
            {
                bool result = true;
                const DWARFAbbreviationDeclaration* abbrevDecl = die.GetAbbreviationDeclarationPtr();

                switch (abbrevDecl->Tag())
                {
                case DW_TAG_array_type:         break;  // print out a "[]" after printing the full type of the element below
                case DW_TAG_base_type:          s->PutCString("base ");         break;
                case DW_TAG_class_type:         s->PutCString("class ");            break;
                case DW_TAG_const_type:         s->PutCString("const ");            break;
                case DW_TAG_enumeration_type:   s->PutCString("enum ");         break;
                case DW_TAG_file_type:          s->PutCString("file ");         break;
                case DW_TAG_interface_type:     s->PutCString("interface ");        break;
                case DW_TAG_packed_type:        s->PutCString("packed ");       break;
                case DW_TAG_pointer_type:       break;  // print out a '*' after printing the full type below
                case DW_TAG_ptr_to_member_type: break;  // print out a '*' after printing the full type below
                case DW_TAG_reference_type:     break;  // print out a '&' after printing the full type below
                case DW_TAG_restrict_type:      s->PutCString("restrict ");     break;
                case DW_TAG_set_type:           s->PutCString("set ");          break;
                case DW_TAG_shared_type:        s->PutCString("shared ");       break;
                case DW_TAG_string_type:        s->PutCString("string ");       break;
                case DW_TAG_structure_type:     s->PutCString("struct ");       break;
                case DW_TAG_subrange_type:      s->PutCString("subrange ");     break;
                case DW_TAG_subroutine_type:    s->PutCString("function ");     break;
                case DW_TAG_thrown_type:        s->PutCString("thrown ");       break;
                case DW_TAG_union_type:         s->PutCString("union ");            break;
                case DW_TAG_unspecified_type:   s->PutCString("unspecified ");  break;
                case DW_TAG_volatile_type:      s->PutCString("volatile ");     break;
                default:
                    return false;
                }

                // Follow the DW_AT_type if possible
                DWARFFormValue form_value;
                if (die.GetAttributeValue(dwarf2Data, cu, DW_AT_type, form_value))
                {
                    uint64_t next_die_offset = form_value.Reference(cu);
                    result = AppendTypeName(dwarf2Data, cu, next_die_offset, s);
                }

                switch (abbrevDecl->Tag())
                {
                case DW_TAG_array_type:         s->PutCString("[]");    break;
                case DW_TAG_pointer_type:       s->PutChar('*');    break;
                case DW_TAG_ptr_to_member_type: s->PutChar('*');    break;
                case DW_TAG_reference_type:     s->PutChar('&');    break;
                default:
                    break;
                }
                return result;
            }
        }
    }
    return false;
}

//----------------------------------------------------------------------
// BuildAddressRangeTable
//----------------------------------------------------------------------
void
DWARFDebugInfoEntry::BuildAddressRangeTable
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    DWARFDebugAranges* debug_aranges
) const
{
    if (m_abbrevDecl)
    {
        dw_tag_t tag = m_abbrevDecl->Tag();
        if (tag == DW_TAG_subprogram)
        {
            dw_addr_t hi_pc = DW_INVALID_ADDRESS;
            dw_addr_t lo_pc = GetAttributeValueAsUnsigned(dwarf2Data, cu, DW_AT_low_pc, DW_INVALID_ADDRESS);
            if (lo_pc != DW_INVALID_ADDRESS)
                hi_pc = GetAttributeValueAsUnsigned(dwarf2Data, cu, DW_AT_high_pc, DW_INVALID_ADDRESS);
            if (hi_pc != DW_INVALID_ADDRESS)
            {
            /// printf("BuildAddressRangeTable() 0x%8.8x: %30s: [0x%8.8x - 0x%8.8x)\n", m_offset, DW_TAG_value_to_name(tag), lo_pc, hi_pc);
                debug_aranges->InsertRange(cu->GetOffset(), lo_pc, hi_pc);
            }
        }


        const DWARFDebugInfoEntry* child = GetFirstChild();
        while (child)
        {
            child->BuildAddressRangeTable(dwarf2Data, cu, debug_aranges);
            child = child->GetSibling();
        }
    }
}

//----------------------------------------------------------------------
// BuildFunctionAddressRangeTable
//
// This function is very similar to the BuildAddressRangeTable function
// except that the actual DIE offset for the function is placed in the
// table instead of the compile unit offset (which is the way the
// standard .debug_aranges section does it).
//----------------------------------------------------------------------
void
DWARFDebugInfoEntry::BuildFunctionAddressRangeTable
(
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    DWARFDebugAranges* debug_aranges
) const
{
    if (m_abbrevDecl)
    {
        dw_tag_t tag = m_abbrevDecl->Tag();
        if (tag == DW_TAG_subprogram)
        {
            dw_addr_t hi_pc = DW_INVALID_ADDRESS;
            dw_addr_t lo_pc = GetAttributeValueAsUnsigned(dwarf2Data, cu, DW_AT_low_pc, DW_INVALID_ADDRESS);
            if (lo_pc != DW_INVALID_ADDRESS)
                hi_pc = GetAttributeValueAsUnsigned(dwarf2Data, cu, DW_AT_high_pc, DW_INVALID_ADDRESS);
            if (hi_pc != DW_INVALID_ADDRESS)
            {
            //  printf("BuildAddressRangeTable() 0x%8.8x: [0x%16.16llx - 0x%16.16llx)\n", m_offset, lo_pc, hi_pc); // DEBUG ONLY
                debug_aranges->InsertRange(GetOffset(), lo_pc, hi_pc);
            }
        }

        const DWARFDebugInfoEntry* child = GetFirstChild();
        while (child)
        {
            child->BuildFunctionAddressRangeTable(dwarf2Data, cu, debug_aranges);
            child = child->GetSibling();
        }
    }
}


//----------------------------------------------------------------------
// LookupAddress
//----------------------------------------------------------------------
bool
DWARFDebugInfoEntry::LookupAddress
(
    const dw_addr_t address,
    SymbolFileDWARF* dwarf2Data,
    const DWARFCompileUnit* cu,
    DWARFDebugInfoEntry** function_die,
    DWARFDebugInfoEntry** block_die
)
{
    bool found_address = false;
    if (m_abbrevDecl)
    {
        bool check_children = false;
        bool match_addr_range = false;
        dw_tag_t tag = m_abbrevDecl->Tag();
    //  printf("0x%8.8x: %30s: address = 0x%8.8x - ", m_offset, DW_TAG_value_to_name(tag), address);
        switch (tag)
        {
        case DW_TAG_array_type                 : break;
        case DW_TAG_class_type                 : check_children = true; break;
        case DW_TAG_entry_point                : break;
        case DW_TAG_enumeration_type           : break;
        case DW_TAG_formal_parameter           : break;
        case DW_TAG_imported_declaration       : break;
        case DW_TAG_label                      : break;
        case DW_TAG_lexical_block              : check_children = true; match_addr_range = true; break;
        case DW_TAG_member                     : break;
        case DW_TAG_pointer_type               : break;
        case DW_TAG_reference_type             : break;
        case DW_TAG_compile_unit               : match_addr_range = true; break;
        case DW_TAG_string_type                : break;
        case DW_TAG_structure_type             : check_children = true; break;
        case DW_TAG_subroutine_type            : break;
        case DW_TAG_typedef                    : break;
        case DW_TAG_union_type                 : break;
        case DW_TAG_unspecified_parameters     : break;
        case DW_TAG_variant                    : break;
        case DW_TAG_common_block               : check_children = true; break;
        case DW_TAG_common_inclusion           : break;
        case DW_TAG_inheritance                : break;
        case DW_TAG_inlined_subroutine         : check_children = true; match_addr_range = true; break;
        case DW_TAG_module                     : match_addr_range = true; break;
        case DW_TAG_ptr_to_member_type         : break;
        case DW_TAG_set_type                   : break;
        case DW_TAG_subrange_type              : break;
        case DW_TAG_with_stmt                  : break;
        case DW_TAG_access_declaration         : break;
        case DW_TAG_base_type                  : break;
        case DW_TAG_catch_block                : match_addr_range = true; break;
        case DW_TAG_const_type                 : break;
        case DW_TAG_constant                   : break;
        case DW_TAG_enumerator                 : break;
        case DW_TAG_file_type                  : break;
        case DW_TAG_friend                     : break;
        case DW_TAG_namelist                   : break;
        case DW_TAG_namelist_item              : break;
        case DW_TAG_packed_type                : break;
        case DW_TAG_subprogram                 : match_addr_range = true; break;
        case DW_TAG_template_type_parameter    : break;
        case DW_TAG_template_value_parameter   : break;
        case DW_TAG_thrown_type                : break;
        case DW_TAG_try_block                  : match_addr_range = true; break;
        case DW_TAG_variant_part               : break;
        case DW_TAG_variable                   : break;
        case DW_TAG_volatile_type              : break;
        case DW_TAG_dwarf_procedure            : break;
        case DW_TAG_restrict_type              : break;
        case DW_TAG_interface_type             : break;
        case DW_TAG_namespace                  : check_children = true; break;
        case DW_TAG_imported_module            : break;
        case DW_TAG_unspecified_type           : break;
        case DW_TAG_partial_unit               : break;
        case DW_TAG_imported_unit              : break;
        case DW_TAG_shared_type                : break;
        default: break;
        }

        if (match_addr_range)
        {
            dw_addr_t lo_pc = GetAttributeValueAsUnsigned(dwarf2Data, cu, DW_AT_low_pc, DW_INVALID_ADDRESS);
            if (lo_pc != DW_INVALID_ADDRESS)
            {
                dw_addr_t hi_pc = GetAttributeValueAsUnsigned(dwarf2Data, cu, DW_AT_high_pc, DW_INVALID_ADDRESS);
                if (hi_pc != DW_INVALID_ADDRESS)
                {
                    //  printf("\n0x%8.8x: %30s: address = 0x%8.8x  [0x%8.8x - 0x%8.8x) ", m_offset, DW_TAG_value_to_name(tag), address, lo_pc, hi_pc);
                    if ((lo_pc <= address) && (address < hi_pc))
                    {
                        found_address = true;
                    //  puts("***MATCH***");
                        switch (tag)
                        {
                        case DW_TAG_compile_unit:       // File
                            check_children = ((function_die != NULL) || (block_die != NULL));
                            break;

                        case DW_TAG_subprogram:         // Function
                            if (function_die)
                                *function_die = this;
                            check_children = (block_die != NULL);
                            break;

                        case DW_TAG_inlined_subroutine: // Inlined Function
                        case DW_TAG_lexical_block:      // Block { } in code
                            if (block_die)
                            {
                                *block_die = this;
                                check_children = true;
                            }
                            break;

                        default:
                            check_children = true;
                            break;
                        }
                    }
                }
                else
                {   // compile units may not have a valid high/low pc when there
                    // are address gaps in subtroutines so we must always search
                    // if there is no valid high and low PC
                    check_children = (tag == DW_TAG_compile_unit) && ((function_die != NULL) || (block_die != NULL));
                }
            }
            else
            {
                dw_offset_t debug_ranges_offset = GetAttributeValueAsUnsigned(dwarf2Data, cu, DW_AT_ranges, DW_INVALID_OFFSET);
                if (debug_ranges_offset != DW_INVALID_OFFSET)
                {
                    DWARFDebugRanges::RangeList ranges;
                    DWARFDebugRanges* debug_ranges = dwarf2Data->DebugRanges();
                    debug_ranges->FindRanges(debug_ranges_offset, ranges);
                    // All DW_AT_ranges are relative to the base address of the
                    // compile unit. We add the compile unit base address to make
                    // sure all the addresses are properly fixed up.
                    ranges.AddOffset(cu->GetBaseAddress());
                    if (ranges.Lookup(address))
                    {
                        found_address = true;
                    //  puts("***MATCH***");
                        switch (tag)
                        {
                        case DW_TAG_compile_unit:       // File
                            check_children = ((function_die != NULL) || (block_die != NULL));
                            break;

                        case DW_TAG_subprogram:         // Function
                            if (function_die)
                                *function_die = this;
                            check_children = (block_die != NULL);
                            break;

                        case DW_TAG_inlined_subroutine: // Inlined Function
                        case DW_TAG_lexical_block:      // Block { } in code
                            if (block_die)
                            {
                                *block_die = this;
                                check_children = true;
                            }
                            break;

                        default:
                            check_children = true;
                            break;
                        }
                    }
                    else
                    {
                        check_children = false;
                    }
                }
            }
        }


        if (check_children)
        {
        //  printf("checking children\n");
            DWARFDebugInfoEntry* child = GetFirstChild();
            while (child)
            {
                if (child->LookupAddress(address, dwarf2Data, cu, function_die, block_die))
                    return true;
                child = child->GetSibling();
            }
        }
    }
    return found_address;
}


bool
DWARFDebugInfoEntry::OffsetLessThan (const DWARFDebugInfoEntry& a, const DWARFDebugInfoEntry& b)
{
    return a.GetOffset() < b.GetOffset();
}