llvm-project/lldb/source/Plugins/SymbolVendor/ELF/SymbolVendorELF.cpp

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

#include "SymbolVendorELF.h"

#include <string.h>

#include "lldb/Core/Module.h"
#include "lldb/Core/ModuleSpec.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/Section.h"
#include "lldb/Core/StreamString.h"
#include "lldb/Core/Timer.h"
#include "lldb/Host/Host.h"
#include "lldb/Host/Symbols.h"
#include "lldb/Symbol/ObjectFile.h"

using namespace lldb;
using namespace lldb_private;

//----------------------------------------------------------------------
// SymbolVendorELF constructor
//----------------------------------------------------------------------
SymbolVendorELF::SymbolVendorELF(const lldb::ModuleSP &module_sp) :
    SymbolVendor (module_sp)
{
}

//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
SymbolVendorELF::~SymbolVendorELF()
{
}

void
SymbolVendorELF::Initialize()
{
    PluginManager::RegisterPlugin (GetPluginNameStatic(),
                                   GetPluginDescriptionStatic(),
                                   CreateInstance);
}

void
SymbolVendorELF::Terminate()
{
    PluginManager::UnregisterPlugin (CreateInstance);
}


lldb_private::ConstString
SymbolVendorELF::GetPluginNameStatic()
{
    static ConstString g_name("ELF");
    return g_name;
}

const char *
SymbolVendorELF::GetPluginDescriptionStatic()
{
    return "Symbol vendor for ELF that looks for dSYM files that match executables.";
}



//----------------------------------------------------------------------
// CreateInstance
//
// Platforms can register a callback to use when creating symbol
// vendors to allow for complex debug information file setups, and to
// also allow for finding separate debug information files.
//----------------------------------------------------------------------
SymbolVendor*
SymbolVendorELF::CreateInstance (const lldb::ModuleSP &module_sp, lldb_private::Stream *feedback_strm)
{
    if (!module_sp)
        return NULL;

    ObjectFile *obj_file = module_sp->GetObjectFile();
    if (!obj_file)
        return NULL;

    static ConstString obj_file_elf("elf");
    ConstString obj_name = obj_file->GetPluginName();
    if (obj_name != obj_file_elf)
        return NULL;

    lldb_private::UUID uuid;
    if (!obj_file->GetUUID (&uuid))
        return NULL;

    // Get the .gnu_debuglink file (if specified).
    FileSpecList file_spec_list = obj_file->GetDebugSymbolFilePaths();

    // If the module specified a filespec, use it first.
    FileSpec debug_symbol_fspec (module_sp->GetSymbolFileFileSpec());
    if (debug_symbol_fspec)
        file_spec_list.Insert (0, debug_symbol_fspec);

    // If we have no debug symbol files, then nothing to do.
    if (file_spec_list.IsEmpty())
        return NULL;

    Timer scoped_timer (__PRETTY_FUNCTION__,
                        "SymbolVendorELF::CreateInstance (module = %s)",
                        module_sp->GetFileSpec().GetPath().c_str());

    for (size_t idx = 0; idx < file_spec_list.GetSize(); ++idx)
    {
        ModuleSpec module_spec;
        const FileSpec fspec = file_spec_list.GetFileSpecAtIndex (idx);

        module_spec.GetFileSpec() = obj_file->GetFileSpec();
        module_spec.GetFileSpec().ResolvePath();
        module_spec.GetSymbolFileSpec() = fspec;
        module_spec.GetUUID() = uuid;
        FileSpec dsym_fspec = Symbols::LocateExecutableSymbolFile (module_spec);
        if (dsym_fspec)
        {
            DataBufferSP dsym_file_data_sp;
            lldb::offset_t dsym_file_data_offset = 0;
            ObjectFileSP dsym_objfile_sp = ObjectFile::FindPlugin(module_sp, &dsym_fspec, 0, dsym_fspec.GetByteSize(), dsym_file_data_sp, dsym_file_data_offset);
            if (dsym_objfile_sp)
            {
                // This objfile is for debugging purposes. Sadly, ObjectFileELF won't be able
                // to figure this out consistently as the symbol file may not have stripped the
                // code sections, etc.
                dsym_objfile_sp->SetType (ObjectFile::eTypeDebugInfo);

                SymbolVendorELF* symbol_vendor = new SymbolVendorELF(module_sp);
                if (symbol_vendor)
                {
                    // Get the module unified section list and add our debug sections to that.
                    SectionList *module_section_list = module_sp->GetSectionList();
                    SectionList *objfile_section_list = dsym_objfile_sp->GetSectionList();

                    static const SectionType g_sections[] =
                    {
                        eSectionTypeDWARFDebugAranges,
                        eSectionTypeDWARFDebugInfo,
                        eSectionTypeDWARFDebugAbbrev,
                        eSectionTypeDWARFDebugFrame,
                        eSectionTypeDWARFDebugLine,
                        eSectionTypeDWARFDebugStr,
                        eSectionTypeDWARFDebugLoc,
                        eSectionTypeDWARFDebugMacInfo,
                        eSectionTypeDWARFDebugPubNames,
                        eSectionTypeDWARFDebugPubTypes,
                        eSectionTypeDWARFDebugRanges,
                        eSectionTypeELFSymbolTable,
                    };
                    for (size_t idx = 0; idx < sizeof(g_sections) / sizeof(g_sections[0]); ++idx)
                    {
                        SectionType section_type = g_sections[idx];
                        SectionSP section_sp (objfile_section_list->FindSectionByType (section_type, true));
                        if (section_sp)
                        {
                            SectionSP module_section_sp (module_section_list->FindSectionByType (section_type, true));
                            if (module_section_sp)
                                module_section_list->ReplaceSection (module_section_sp->GetID(), section_sp);
                            else
                                module_section_list->AddSection (section_sp);
                        }
                    }

                    symbol_vendor->AddSymbolFileRepresentation (dsym_objfile_sp);
                    return symbol_vendor;
                }
            }
        }
    }
    return NULL;
}

//------------------------------------------------------------------
// PluginInterface protocol
//------------------------------------------------------------------
ConstString
SymbolVendorELF::GetPluginName()
{
    return GetPluginNameStatic();
}

uint32_t
SymbolVendorELF::GetPluginVersion()
{
    return 1;
}