llvm-project/lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugAranges.cpp

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

#include "DWARFDebugAranges.h"

#include <assert.h>
#include <stdio.h>

#include <algorithm>

#include "lldb/Core/Log.h"
#include "lldb/Core/Stream.h"
#include "lldb/Core/Timer.h"

#include "LogChannelDWARF.h"
#include "SymbolFileDWARF.h"
#include "DWARFDebugInfo.h"
#include "DWARFCompileUnit.h"

using namespace lldb;
using namespace lldb_private;

//----------------------------------------------------------------------
// Constructor
//----------------------------------------------------------------------
DWARFDebugAranges::DWARFDebugAranges() :
    m_aranges()
{
}

//----------------------------------------------------------------------
// CountArangeDescriptors
//----------------------------------------------------------------------
class CountArangeDescriptors
{
public:
    CountArangeDescriptors (uint32_t& count_ref) : count(count_ref)
    {
//      printf("constructor CountArangeDescriptors()\n");
    }
    void operator() (const DWARFDebugArangeSet& set)
    {
        count += set.NumDescriptors();
    }
    uint32_t& count;
};


//----------------------------------------------------------------------
// Extract
//----------------------------------------------------------------------
bool
DWARFDebugAranges::Extract(const DWARFDataExtractor &debug_aranges_data)
{
    if (debug_aranges_data.ValidOffset(0))
    {
        lldb::offset_t offset = 0;

        DWARFDebugArangeSet set;
        Range range;
        while (set.Extract(debug_aranges_data, &offset))
        {
            const uint32_t num_descriptors = set.NumDescriptors();
            if (num_descriptors > 0)
            {
                const dw_offset_t cu_offset = set.GetCompileUnitDIEOffset();
                
                for (uint32_t i=0; i<num_descriptors; ++i)
                {
                    const DWARFDebugArangeSet::Descriptor &descriptor = set.GetDescriptorRef(i);
                    m_aranges.Append(RangeToDIE::Entry (descriptor.address, descriptor.length, cu_offset));
                }
            }
            set.Clear();
        }
    }
    return false;
}

//----------------------------------------------------------------------
// Generate
//----------------------------------------------------------------------
bool
DWARFDebugAranges::Generate(SymbolFileDWARF* dwarf2Data)
{
    Clear();
    DWARFDebugInfo* debug_info = dwarf2Data->DebugInfo();
    if (debug_info)
    {
        uint32_t cu_idx = 0;
        const uint32_t num_compile_units = dwarf2Data->GetNumCompileUnits();
        for (cu_idx = 0; cu_idx < num_compile_units; ++cu_idx)
        {
            DWARFCompileUnit* cu = debug_info->GetCompileUnitAtIndex(cu_idx);
            if (cu)
                cu->BuildAddressRangeTable(dwarf2Data, this);
        }
    }
    return !IsEmpty();
}


void
DWARFDebugAranges::Dump (Log *log) const
{
    if (log == NULL)
        return;
    
    const size_t num_entries = m_aranges.GetSize();
    for (size_t i=0; i<num_entries; ++i)
    {
        const RangeToDIE::Entry *entry = m_aranges.GetEntryAtIndex(i);
        if (entry)
            log->Printf ("0x%8.8x: [0x%" PRIx64 " - 0x%" PRIx64 ")",
                         entry->data,
                         entry->GetRangeBase(),
                         entry->GetRangeEnd());
    }
}

void
DWARFDebugAranges::AppendRange (dw_offset_t offset, dw_addr_t low_pc, dw_addr_t high_pc)
{
    if (high_pc > low_pc)
        m_aranges.Append(RangeToDIE::Entry (low_pc, high_pc - low_pc, offset));
}

void
DWARFDebugAranges::Sort (bool minimize)
{    
    Timer scoped_timer(__PRETTY_FUNCTION__, "%s this = %p",
                       __PRETTY_FUNCTION__, static_cast<void*>(this));

    Log *log (LogChannelDWARF::GetLogIfAll(DWARF_LOG_DEBUG_ARANGES));
    size_t orig_arange_size = 0;
    if (log)
    {
        orig_arange_size = m_aranges.GetSize();
        log->Printf ("DWARFDebugAranges::Sort(minimize = %u) with %" PRIu64 " entries", minimize, (uint64_t)orig_arange_size);
    }

    m_aranges.Sort();
    m_aranges.CombineConsecutiveEntriesWithEqualData();

    if (log)
    {
        if (minimize)
        {
            const size_t new_arange_size = m_aranges.GetSize();
            const size_t delta = orig_arange_size - new_arange_size;
            log->Printf ("DWARFDebugAranges::Sort() %" PRIu64 " entries after minimizing (%" PRIu64 " entries combined for %" PRIu64 " bytes saved)",
                         (uint64_t)new_arange_size,
                         (uint64_t)delta,
                         (uint64_t)delta * sizeof(Range));
        }
        Dump (log);
    }
}

//----------------------------------------------------------------------
// FindAddress
//----------------------------------------------------------------------
dw_offset_t
DWARFDebugAranges::FindAddress(dw_addr_t address) const
{
    const RangeToDIE::Entry *entry = m_aranges.FindEntryThatContains(address);
    if (entry)
        return entry->data;
    return DW_INVALID_OFFSET;
}