clang-p2996/lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderMacOSXDYLD.h

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


// This is the DynamicLoader plugin for Darwin (macOS / iPhoneOS / tvOS / watchOS)
// platforms earlier than 2016, where lldb would read the "dyld_all_image_infos"
// dyld internal structure to understand where things were loaded and the 
// solib loaded/unloaded notification function we put a breakpoint on gives us
// an array of (load address, mod time, file path) tuples.
//
// As of late 2016, the new DynamicLoaderMacOS plugin should be used, which uses
// dyld SPI functions to get the same information without reading internal dyld
// data structures.

#ifndef liblldb_DynamicLoaderMacOSXDYLD_h_
#define liblldb_DynamicLoaderMacOSXDYLD_h_

// C Includes
// C++ Includes
#include <vector>
#include <mutex>

// Other libraries and framework includes
// Project includes
#include "lldb/Target/DynamicLoader.h"
#include "lldb/Host/FileSpec.h"
#include "lldb/Core/StructuredData.h"
#include "lldb/Core/UUID.h"
#include "lldb/Target/Process.h"
#include "lldb/Utility/SafeMachO.h"

#include "DynamicLoaderDarwin.h"

class DynamicLoaderMacOSXDYLD : public lldb_private::DynamicLoaderDarwin
{
public:
    DynamicLoaderMacOSXDYLD(lldb_private::Process *process);

    virtual ~DynamicLoaderMacOSXDYLD() override;

    //------------------------------------------------------------------
    // Static Functions
    //------------------------------------------------------------------
    static void
    Initialize();

    static void
    Terminate();

    static lldb_private::ConstString
    GetPluginNameStatic();

    static const char *
    GetPluginDescriptionStatic();

    static lldb_private::DynamicLoader *
    CreateInstance (lldb_private::Process *process, bool force);

    //------------------------------------------------------------------
    /// Called after attaching a process.
    ///
    /// Allow DynamicLoader plug-ins to execute some code after
    /// attaching to a process.
    //------------------------------------------------------------------
    bool
    ProcessDidExec() override;

    lldb_private::Error
    CanLoadImage() override;

    bool
    GetSharedCacheInformation (lldb::addr_t &base_address,
                               lldb_private::UUID &uuid,
                               lldb_private::LazyBool &using_shared_cache,
                               lldb_private::LazyBool &private_shared_cache) override;

    //------------------------------------------------------------------
    // PluginInterface protocol
    //------------------------------------------------------------------
    lldb_private::ConstString
    GetPluginName() override;

    uint32_t
    GetPluginVersion() override;

protected:
    void
    PutToLog(lldb_private::Log *log) const;

    void
    DoInitialImageFetch () override;

    bool
    NeedToDoInitialImageFetch () override;

    bool
    DidSetNotificationBreakpoint () override;

    void
    DoClear () override;

    bool
    ReadDYLDInfoFromMemoryAndSetNotificationCallback (lldb::addr_t addr);

    static bool
    NotifyBreakpointHit (void *baton,
                         lldb_private::StoppointCallbackContext *context,
                         lldb::user_id_t break_id,
                         lldb::user_id_t break_loc_id);

    uint32_t
    AddrByteSize();

    bool
    ReadMachHeader (lldb::addr_t addr,
                    llvm::MachO::mach_header *header,
                    lldb_private::DataExtractor *load_command_data);

    uint32_t
    ParseLoadCommands (const lldb_private::DataExtractor& data,
                       ImageInfo& dylib_info,
                       lldb_private::FileSpec *lc_id_dylinker);

    struct DYLDAllImageInfos
    {
        uint32_t version;
        uint32_t dylib_info_count;              // Version >= 1
        lldb::addr_t dylib_info_addr;           // Version >= 1
        lldb::addr_t notification;              // Version >= 1
        bool processDetachedFromSharedRegion;   // Version >= 1
        bool libSystemInitialized;              // Version >= 2
        lldb::addr_t dyldImageLoadAddress;      // Version >= 2

        DYLDAllImageInfos() :
            version (0),
            dylib_info_count (0),
            dylib_info_addr (LLDB_INVALID_ADDRESS),
            notification (LLDB_INVALID_ADDRESS),
            processDetachedFromSharedRegion (false),
            libSystemInitialized (false),
            dyldImageLoadAddress (LLDB_INVALID_ADDRESS)
        {
        }

        void
        Clear()
        {
            version = 0;
            dylib_info_count = 0;
            dylib_info_addr = LLDB_INVALID_ADDRESS;
            notification = LLDB_INVALID_ADDRESS;
            processDetachedFromSharedRegion = false;
            libSystemInitialized = false;
            dyldImageLoadAddress = LLDB_INVALID_ADDRESS;
        }

        bool
        IsValid() const
        {
            return version >= 1 || version <= 6;
        }
    };

    static lldb::ByteOrder
    GetByteOrderFromMagic(uint32_t magic);

    bool
    SetNotificationBreakpoint () override;

    void
    ClearNotificationBreakpoint () override;

    // There is a little tricky bit where you might initially attach while dyld is updating
    // the all_image_infos, and you can't read the infos, so you have to continue and pick it
    // up when you hit the update breakpoint.  At that point, you need to run this initialize
    // function, but when you do it that way you DON'T need to do the extra work you would at
    // the breakpoint.
    // So this function will only do actual work if the image infos haven't been read yet.
    // If it does do any work, then it will return true, and false otherwise.  That way you can
    // call it in the breakpoint action, and if it returns true you're done.
    bool
    InitializeFromAllImageInfos ();

    bool
    ReadAllImageInfosStructure ();
    
    bool
    AddModulesUsingImageInfosAddress (lldb::addr_t image_infos_addr, uint32_t image_infos_count);
    
    bool
    RemoveModulesUsingImageInfosAddress (lldb::addr_t image_infos_addr, uint32_t image_infos_count);

    void
    UpdateImageInfosHeaderAndLoadCommands(ImageInfo::collection &image_infos, 
                                          uint32_t infos_count, 
                                          bool update_executable);

    bool
    ReadImageInfos (lldb::addr_t image_infos_addr, 
                    uint32_t image_infos_count, 
                    ImageInfo::collection &image_infos);

    lldb::addr_t m_dyld_all_image_infos_addr;
    DYLDAllImageInfos m_dyld_all_image_infos;
    uint32_t m_dyld_all_image_infos_stop_id;
    lldb::user_id_t m_break_id;
    mutable std::recursive_mutex m_mutex;
    bool m_process_image_addr_is_all_images_infos;

private:
    DISALLOW_COPY_AND_ASSIGN (DynamicLoaderMacOSXDYLD);
};

#endif // liblldb_DynamicLoaderMacOSXDYLD_h_