llvm-project/lldb/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTrampolineHandler.h

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

#ifndef lldb_AppleObjCTrampolineHandler_h_
#define lldb_AppleObjCTrampolineHandler_h_

// C Includes
// C++ Includes
#include <map>
#include <string>
// Other libraries and framework includes
// Project includes
#include "lldb/Expression/ClangExpression.h"
#include "lldb/Expression/ClangFunction.h"
#include "lldb/Expression/ClangUtilityFunction.h"
#include "lldb/Host/Mutex.h"


namespace lldb_private
{
using namespace lldb;
  
class AppleObjCTrampolineHandler {
public:
    
    AppleObjCTrampolineHandler (ProcessSP process_sp, ModuleSP objc_module_sp);
    
    ~AppleObjCTrampolineHandler() {}
            
    ThreadPlanSP
    GetStepThroughDispatchPlan (Thread &thread, bool stop_others);
    
    ClangFunction *
    GetLookupImplementationWrapperFunction ();
    
    bool 
    AddrIsMsgForward (lldb::addr_t addr) const
    {
        return (addr == m_msg_forward_addr || addr == m_msg_forward_stret_addr);
    }

    
    struct DispatchFunction {
    public:
        typedef enum 
        {
            eFixUpNone,
            eFixUpFixed,
            eFixUpToFix
        } FixUpState;
                
        const char *name;
        bool stret_return;
        bool is_super;
        bool is_super2;
        FixUpState fixedup;
    };
    
private:
    static const char *g_lookup_implementation_function_name;
    static const char *g_lookup_implementation_function_code;

    class AppleObjCVTables
    {
    public:
        // These come from objc-gdb.h.
        enum VTableFlags
        {
             eOBJC_TRAMPOLINE_MESSAGE = (1<<0),   // trampoline acts like objc_msgSend                                                           
             eOBJC_TRAMPOLINE_STRET   = (1<<1),   // trampoline is struct-returning                                                              
             eOBJC_TRAMPOLINE_VTABLE  = (1<<2),   // trampoline is vtable dispatcher                                                             
        };
            
    private:
        struct VTableDescriptor 
        {
            VTableDescriptor(uint32_t in_flags, addr_t in_code_start) :
                flags(in_flags),
                code_start(in_code_start) {}
            
            uint32_t flags;
            lldb::addr_t code_start;
        };


        class VTableRegion 
        {
        public:
            VTableRegion() :
                    m_valid (false),
                    m_owner (NULL),
                    m_header_addr (LLDB_INVALID_ADDRESS),
                    m_code_start_addr(0),
                    m_code_end_addr (0),
                    m_next_region (0)
            {}
            
            VTableRegion(AppleObjCVTables *owner, lldb::addr_t header_addr);
            
            void SetUpRegion();
                        
            lldb::addr_t GetNextRegionAddr ()
            {
                return m_next_region;
            }
            
            lldb::addr_t
            GetCodeStart ()
            {
                return m_code_start_addr;
            }
            
            lldb::addr_t
            GetCodeEnd ()
            {
                return m_code_end_addr;
            }
            
            uint32_t
            GetFlagsForVTableAtAddress (lldb::addr_t address)
            {
                return 0;
            }
            
            bool
            IsValid ()
            {
                return m_valid;
            }
            
            bool 
            AddressInRegion (lldb::addr_t addr, uint32_t &flags);
            
            void
            Dump (Stream &s);
            
        public:
            bool m_valid;
            AppleObjCVTables *m_owner;
            lldb::addr_t m_header_addr;
            lldb::addr_t m_code_start_addr;
            lldb::addr_t m_code_end_addr;
            std::vector<VTableDescriptor> m_descriptors;
            lldb::addr_t m_next_region;
        };
        
    public:
        AppleObjCVTables(ProcessSP &process_sp, ModuleSP &objc_module_sp);
        
        ~AppleObjCVTables();
                
        bool
        InitializeVTableSymbols ();
                
        static bool RefreshTrampolines (void *baton, 
                                        StoppointCallbackContext *context, 
                                        lldb::user_id_t break_id, 
                                        lldb::user_id_t break_loc_id);
        bool
        ReadRegions ();
        
        bool
        ReadRegions (lldb::addr_t region_addr);
                
        bool
        IsAddressInVTables (lldb::addr_t addr, uint32_t &flags);
                
        Process *GetProcess ()
        {   
            return m_process_sp.get();
        }
        
    private:
        ProcessSP m_process_sp;
        typedef std::vector<VTableRegion> region_collection;
        lldb::addr_t m_trampoline_header;
        lldb::break_id_t m_trampolines_changed_bp_id;
        region_collection m_regions;
        lldb::ModuleSP m_objc_module_sp;
        
    };
    
    static const DispatchFunction g_dispatch_functions[];
    
    typedef std::map<lldb::addr_t, int> MsgsendMap; // This table maps an dispatch fn address to the index in g_dispatch_functions
    MsgsendMap m_msgSend_map;
    ProcessSP m_process_sp;
    ModuleSP m_objc_module_sp;
    std::auto_ptr<ClangFunction> m_impl_function;
    std::auto_ptr<ClangUtilityFunction> m_impl_code;
    Mutex m_impl_function_mutex;
    lldb::addr_t m_impl_fn_addr;
    lldb::addr_t m_impl_stret_fn_addr;
    lldb::addr_t m_msg_forward_addr;
    lldb::addr_t m_msg_forward_stret_addr;
    std::auto_ptr<AppleObjCVTables> m_vtables_ap;
    
     
};

}  // using namespace lldb_private

#endif	// lldb_AppleObjCTrampolineHandler_h_