fpc/compiler/nobj.pas

{
    Copyright (c) 1998-2002 by Florian Klaempfl

    Routines for the code generation of data structures
    like VMT, Messages, VTables, Interfaces descs

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 ****************************************************************************
}
unit nobj;

{$i fpcdefs.inc}

interface

    uses
       cutils,cclasses,
       globtype,
       symdef,symsym,
       aasmbase,aasmtai,aasmdata
       ;

    type
      TVMTBuilder=class
      private
        _Class : tobjectdef;
        function  is_new_vmt_entry(pd:tprocdef):boolean;
        procedure add_new_vmt_entry(pd:tprocdef);
        function  intf_search_procdef_by_name(proc: tprocdef;const name: string): tprocdef;
        procedure intf_get_procdefs(ImplIntf:TImplementedInterface;IntfDef:TObjectDef);
        procedure intf_get_procdefs_recursive(ImplIntf:TImplementedInterface;IntfDef:TObjectDef);
        procedure intf_optimize_vtbls;
        procedure intf_allocate_vtbls;
      public
        constructor create(c:tobjectdef);
        destructor  destroy;override;
        procedure generate_vmt;
      end;

    type
      pprocdeftree = ^tprocdeftree;
      tprocdeftree = record
         data : tprocdef;
         nl   : tasmlabel;
         l,r  : pprocdeftree;
      end;

      TVMTWriter=class
      private
        _Class : tobjectdef;
        { message tables }
        root : pprocdeftree;
        procedure disposeprocdeftree(p : pprocdeftree);
        procedure insertmsgint(p:TObject;arg:pointer);
        procedure insertmsgstr(p:TObject;arg:pointer);
        procedure insertint(p : pprocdeftree;var at : pprocdeftree;var count:longint);
        procedure insertstr(p : pprocdeftree;var at : pprocdeftree;var count:longint);
        procedure writenames(p : pprocdeftree);
        procedure writeintentry(p : pprocdeftree);
        procedure writestrentry(p : pprocdeftree);
{$ifdef WITHDMT}
        { dmt }
        procedure insertdmtentry(p:TObject;arg:pointer);
        procedure writedmtindexentry(p : pprocdeftree);
        procedure writedmtaddressentry(p : pprocdeftree);
{$endif}
        { published methods }
        procedure do_count_published_methods(p:TObject;arg:pointer);
        procedure do_gen_published_methods(p:TObject;arg:pointer);
        { virtual methods }
        procedure writevirtualmethods(List:TAsmList);
        { interface tables }
        function  intf_get_vtbl_name(AImplIntf:TImplementedInterface): string;
        procedure intf_create_vtbl(rawdata: TAsmList;AImplIntf:TImplementedInterface);
        procedure intf_gen_intf_ref(rawdata: TAsmList;AImplIntf:TImplementedInterface);
        function  intf_write_table:TAsmLabel;
        { generates the message tables for a class }
        function  genstrmsgtab : tasmlabel;
        function  genintmsgtab : tasmlabel;
        function  genpublishedmethodstable : tasmlabel;
        function  generate_field_table : tasmlabel;
{$ifdef WITHDMT}
        { generates a DMT for _class }
        function  gendmt : tasmlabel;
{$endif WITHDMT}
      public
        constructor create(c:tobjectdef);
        destructor destroy;override;
        { write the VMT to al_globals }
        procedure writevmt;
        procedure writeinterfaceids;
      end;

implementation

    uses
       SysUtils,
       globals,verbose,systems,
       node,
       symbase,symtable,symconst,symtype,defcmp,
       dbgbase,
       ncgrtti,
       wpobase
       ;


{*****************************************************************************
                              TVMTBuilder
*****************************************************************************}

    constructor TVMTBuilder.create(c:tobjectdef);
      begin
        inherited Create;
        _Class:=c;
      end;


    destructor TVMTBuilder.destroy;
      begin
      end;


    procedure TVMTBuilder.add_new_vmt_entry(pd:tprocdef);
      var
        i : longint;
        vmtentry : pvmtentry;
        vmtpd : tprocdef;
      begin
        { new entry is needed, override was not possible }
        if (po_overridingmethod in pd.procoptions) then
          MessagePos1(pd.fileinfo,parser_e_nothing_to_be_overridden,pd.fullprocname(false));

        { check that all methods have overload directive }
        if not(m_fpc in current_settings.modeswitches) then
          begin
            for i:=0 to _class.vmtentries.count-1 do
              begin
                vmtentry:=pvmtentry(_class.vmtentries[i]);
                vmtpd:=tprocdef(vmtentry^.procdef);
                if (vmtpd.procsym=pd.procsym) and
                   (not(po_overload in pd.procoptions) or
                    not(po_overload in vmtpd.procoptions)) then
                  begin
                    MessagePos1(pd.fileinfo,parser_e_no_overload_for_all_procs,pd.procsym.realname);
                    { recover }
                    include(vmtpd.procoptions,po_overload);
                    include(pd.procoptions,po_overload);
                  end;
              end;
          end;

        { Register virtual method and give it a number }
        if (po_virtualmethod in pd.procoptions) then
          begin
             { store vmt entry number in procdef }
             if (pd.extnumber<>$ffff) and
                (pd.extnumber<>_class.VMTEntries.Count) then
               internalerror(200810283);
             pd.extnumber:=_class.VMTEntries.Count;
             new(vmtentry);
             vmtentry^.procdef:=pd;
             vmtentry^.procdefderef.reset;
             vmtentry^.visibility:=pd.visibility;
             _class.VMTEntries.Add(vmtentry);
          end;
      end;


    function TVMTBuilder.is_new_vmt_entry(pd:tprocdef):boolean;
      const
        po_comp = [po_classmethod,po_virtualmethod,po_staticmethod,po_interrupt,po_iocheck,po_msgstr,po_msgint,
                   po_exports,po_varargs,po_explicitparaloc,po_nostackframe];
      var
        i : longint;
        hasequalpara,
        hasoverloads,
        pdoverload : boolean;
        vmtentry : pvmtentry;
        vmtpd : tprocdef;
      begin
        result:=false;
        { Load other values for easier readability }
        hasoverloads:=(tprocsym(pd.procsym).ProcdefList.Count>1);
        pdoverload:=(po_overload in pd.procoptions);

        { compare with all stored definitions }
        for i:=0 to _class.vmtentries.Count-1 do
          begin
            vmtentry:=pvmtentry(_class.vmtentries[i]);
            vmtpd:=tprocdef(vmtentry^.procdef);

            { ignore hidden entries (e.g. virtual overridden by a static) that are not visible anymore }
            if vmtentry^.visibility=vis_hidden then
              continue;

            { ignore different names }
            if vmtpd.procsym.name<>pd.procsym.name then
              continue;

            { hide private methods that are not visible anymore. For this check we
              must override the visibility with the highest value in the override chain.
              This is required for case (see tw3292) with protected-private-protected where the
              same vmtentry is used (PFV) }
            if not is_visible_for_object(vmtpd.owner,vmtentry^.visibility,_class) then
              continue;

            { inherit overload }
            if (po_overload in vmtpd.procoptions) then
              begin
                include(pd.procoptions,po_overload);
                pdoverload:=true;
              end;

            { compare parameter types only, no specifiers yet }
            hasequalpara:=(compare_paras(vmtpd.paras,pd.paras,cp_none,[])>=te_equal);

            { check that we are not trying to override a final method }
            if (po_finalmethod in vmtpd.procoptions) and 
               hasequalpara and (po_overridingmethod in pd.procoptions) and is_class(_class) then
              MessagePos1(pd.fileinfo,parser_e_final_can_no_be_overridden,pd.fullprocname(false))
            else
            { old definition has virtual
              new definition has no virtual or override }
            if (po_virtualmethod in vmtpd.procoptions) and
               (
                not(po_virtualmethod in pd.procoptions) or
                { new one has not override }
                (is_class_or_interface(_class) and not(po_overridingmethod in pd.procoptions))
               ) then
              begin
                if (
                    not(pdoverload or hasoverloads) or
                    hasequalpara
                   ) then
                  begin
                    if not(po_reintroduce in pd.procoptions) then
                      MessagePos1(pd.fileinfo,parser_w_should_use_override,pd.fullprocname(false));
                    { disable/hide old VMT entry }
                    vmtentry^.visibility:=vis_hidden;
                  end;
              end
            { both are virtual? }
            else if (po_virtualmethod in pd.procoptions) and
                    (po_virtualmethod in vmtpd.procoptions) then
              begin
                { same parameter and return types (parameter specifiers will be checked below) }
                if hasequalpara and
                   compatible_childmethod_resultdef(vmtpd.returndef,pd.returndef) then
                  begin
                    { inherite calling convention when it was explicit and the
                      current definition has none explicit set }
                    if (po_hascallingconvention in vmtpd.procoptions) and
                       not(po_hascallingconvention in pd.procoptions) then
                      begin
                        pd.proccalloption:=vmtpd.proccalloption;
                        include(pd.procoptions,po_hascallingconvention);
                      end;

                    { All parameter specifiers and some procedure the flags have to match
                      except abstract and override }
                    if (compare_paras(vmtpd.paras,pd.paras,cp_all,[])<te_equal) or
                       (vmtpd.proccalloption<>pd.proccalloption) or
                       (vmtpd.proctypeoption<>pd.proctypeoption) or
                       ((vmtpd.procoptions*po_comp)<>(pd.procoptions*po_comp)) then
                       begin
                         MessagePos1(pd.fileinfo,parser_e_header_dont_match_forward,pd.fullprocname(false));
                         tprocsym(vmtpd.procsym).write_parameter_lists(pd);
                       end;

                    { Give a note if the new visibility is lower. For a higher
                      visibility update the vmt info }
                    if vmtentry^.visibility>pd.visibility then
                      MessagePos4(pd.fileinfo,parser_n_ignore_lower_visibility,pd.fullprocname(false),
                           visibilityname[pd.visibility],tobjectdef(vmtpd.owner.defowner).objrealname^,visibilityname[vmtentry^.visibility])
                    else if pd.visibility>vmtentry^.visibility then
                      vmtentry^.visibility:=pd.visibility;

                    { override old virtual method in VMT }
                    if (vmtpd.extnumber<>i) then
                      internalerror(200611084);
                    pd.extnumber:=vmtpd.extnumber;
                    vmtentry^.procdef:=pd;
                    exit;
                  end
                { different parameters }
                else
                 begin
                   { when we got an override directive then can search futher for
                     the procedure to override.
                     If we are starting a new virtual tree then hide the old tree }
                   if not(po_overridingmethod in pd.procoptions) and
                      not(pdoverload or hasoverloads) then
                     begin
                       if not(po_reintroduce in pd.procoptions) then
                         begin
                           if not is_object(_class) then
                             MessagePos1(pd.fileinfo,parser_w_should_use_override,pd.fullprocname(false))
                           else
                             { objects don't allow starting a new virtual tree }
                             MessagePos1(pd.fileinfo,parser_e_header_dont_match_forward,vmtpd.fullprocname(false));
                         end;
                       { disable/hide old VMT entry }
                       vmtentry^.visibility:=vis_hidden;
                     end;
                 end;
              end;
          end;
        { No entry found, we need to create a new entry }
        result:=true;
      end;


    function TVMTBuilder.intf_search_procdef_by_name(proc: tprocdef;const name: string): tprocdef;
      const
        po_comp = [po_classmethod,po_staticmethod,po_interrupt,po_iocheck,po_msgstr,po_msgint,
                   po_exports,po_varargs,po_explicitparaloc,po_nostackframe];
      var
        implprocdef : Tprocdef;
        i: cardinal;
        hclass : tobjectdef;
        hashedid : THashedIDString;
        srsym      : tsym;
      begin
        result:=nil;
        hashedid.id:=name;
        hclass:=_class;
        while assigned(hclass) do
          begin
            srsym:=tsym(hclass.symtable.FindWithHash(hashedid));
            if assigned(srsym) and
               (srsym.typ=procsym) then
              begin
                for i:=0 to Tprocsym(srsym).ProcdefList.Count-1 do
                  begin
                    implprocdef:=tprocdef(tprocsym(srsym).ProcdefList[i]);
                    if (implprocdef.procsym=tprocsym(srsym)) and
                       (compare_paras(proc.paras,implprocdef.paras,cp_all,[cpo_ignorehidden,cpo_comparedefaultvalue])>=te_equal) and
                       (compare_defs(proc.returndef,implprocdef.returndef,nothingn)>=te_equal) and
                       (proc.proccalloption=implprocdef.proccalloption) and
                       (proc.proctypeoption=implprocdef.proctypeoption) and
                       ((proc.procoptions*po_comp)=((implprocdef.procoptions+[po_virtualmethod])*po_comp)) then
                      begin
                        result:=implprocdef;
                        exit;
                      end;
                  end;
              end;
            hclass:=hclass.childof;
          end;
      end;


    procedure TVMTBuilder.intf_get_procdefs(ImplIntf:TImplementedInterface;IntfDef:TObjectDef);
      var
        i   : longint;
        def : tdef;
        hs,
        prefix,
        mappedname: string;
        implprocdef: tprocdef;
      begin
        prefix:=ImplIntf.IntfDef.symtable.name^+'.';
        for i:=0 to IntfDef.symtable.DefList.Count-1 do
          begin
            def:=tdef(IntfDef.symtable.DefList[i]);
            if assigned(def) and
               (def.typ=procdef) then
              begin
                { Find implementing procdef
                   1. Check for mapped name
                   2. Use symbol name }
                implprocdef:=nil;
                hs:=prefix+tprocdef(def).procsym.name;
                mappedname:=ImplIntf.GetMapping(hs);
                if mappedname<>'' then
                  implprocdef:=intf_search_procdef_by_name(tprocdef(def),mappedname);
                if not assigned(implprocdef) then
                  implprocdef:=intf_search_procdef_by_name(tprocdef(def),tprocdef(def).procsym.name);
                { Add procdef to the implemented interface }
                if assigned(implprocdef) then
                  ImplIntf.AddImplProc(implprocdef)
                else
                  if ImplIntf.IType=etStandard then
                    Message1(sym_e_no_matching_implementation_found,tprocdef(def).fullprocname(false));
              end;
          end;
      end;


    procedure TVMTBuilder.intf_get_procdefs_recursive(ImplIntf:TImplementedInterface;IntfDef:TObjectDef);
      begin
        if assigned(IntfDef.childof) then
          intf_get_procdefs_recursive(ImplIntf,IntfDef.childof);
        intf_get_procdefs(ImplIntf,IntfDef);
      end;


    procedure TVMTBuilder.intf_optimize_vtbls;
      type
        tcompintfentry = record
          weight: longint;
          compintf: longint;
        end;
        { Max 1000 interface in the class header interfaces it's enough imho }
        tcompintfs = array[0..1000] of tcompintfentry;
        pcompintfs = ^tcompintfs;
        tequals    = array[0..1000] of longint;
        pequals    = ^tequals;
        timpls    = array[0..1000] of longint;
        pimpls    = ^timpls;
      var
        equals: pequals;
        compats: pcompintfs;
        impls: pimpls;
        ImplIntfCount,
        w,i,j,k: longint;
        ImplIntfI,
        ImplIntfJ  : TImplementedInterface;
        cij: boolean;
        cji: boolean;
      begin
        ImplIntfCount:=_class.ImplementedInterfaces.count;
        if ImplIntfCount>=High(tequals) then
          Internalerror(200006135);
        getmem(compats,sizeof(tcompintfentry)*ImplIntfCount);
        getmem(equals,sizeof(longint)*ImplIntfCount);
        getmem(impls,sizeof(longint)*ImplIntfCount);
        filldword(compats^,(sizeof(tcompintfentry) div sizeof(dword))*ImplIntfCount,dword(-1));
        filldword(equals^,ImplIntfCount,dword(-1));
        filldword(impls^,ImplIntfCount,dword(-1));
        { ismergepossible is a containing relation
          meaning of ismergepossible(a,b,w) =
          if implementorfunction map of a is contained implementorfunction map of b
          imp(a,b) and imp(b,c) => imp(a,c) ; imp(a,b) and imp(b,a) => a == b
        }
        { the order is very important for correct allocation }
        for i:=0 to ImplIntfCount-1 do
          begin
            for j:=i+1 to ImplIntfCount-1 do
              begin
                ImplIntfI:=TImplementedInterface(_class.ImplementedInterfaces[i]);
                ImplIntfJ:=TImplementedInterface(_class.ImplementedInterfaces[j]);
                cij:=ImplIntfI.IsImplMergePossible(ImplIntfJ,w);
                cji:=ImplIntfJ.IsImplMergePossible(ImplIntfI,w);
                if cij and cji then { i equal j }
                  begin
                    { get minimum index of equal }
                    if equals^[j]=-1 then
                      equals^[j]:=i;
                  end
                else if cij then
                  begin
                    { get minimum index of maximum weight  }
                    if compats^[i].weight<w then
                      begin
                        compats^[i].weight:=w;
                        compats^[i].compintf:=j;
                      end;
                  end
                else if cji then
                  begin
                    { get minimum index of maximum weight  }
                    if (compats^[j].weight<w) then
                      begin
                        compats^[j].weight:=w;
                        compats^[j].compintf:=i;
                      end;
                  end;
              end;
          end;
        { Reset, no replacements by default }
        for i:=0 to ImplIntfCount-1 do
          impls^[i]:=i;
        { Replace vtbls when equal or compat, repeat
          until there are no replacements possible anymore. This is
          needed for the cases like:
            First loop: 2->3, 3->1
            Second loop: 2->1 (because 3 was replaced with 1)
        }
        repeat
          k:=0;
          for i:=0 to ImplIntfCount-1 do
            begin
              if compats^[impls^[i]].compintf<>-1 then
                impls^[i]:=compats^[impls^[i]].compintf
              else if equals^[impls^[i]]<>-1 then
                impls^[i]:=equals^[impls^[i]]
              else
                inc(k);
            end;
        until k=ImplIntfCount;
        { Update the VtblImplIntf }
        for i:=0 to ImplIntfCount-1 do
          begin
            ImplIntfI:=TImplementedInterface(_class.ImplementedInterfaces[i]);
            ImplIntfI.VtblImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[impls^[i]]);
          end;
        freemem(compats);
        freemem(equals);
        freemem(impls);
      end;


    procedure TVMTBuilder.intf_allocate_vtbls;
      var
        i : longint;
        ImplIntf : TImplementedInterface;
      begin
        { Allocation vtbl space }
        for i:=0 to _class.ImplementedInterfaces.count-1 do
          begin
            ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
            { if it implements itself and if it's not implemented by delegation }
            if (ImplIntf.VtblImplIntf=ImplIntf) and (ImplIntf.IType=etStandard) then
              begin
                { allocate a pointer in the object memory }
                with tObjectSymtable(_class.symtable) do
                  begin
                    datasize:=align(datasize,sizeof(pint));
                    ImplIntf.Ioffset:=datasize;
                    datasize:=datasize+sizeof(pint);
                  end;
              end;
          end;
        { Update ioffset of current interface with the ioffset from
          the interface that is reused to implements this interface }
        for i:=0 to _class.ImplementedInterfaces.count-1 do
          begin
            ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
            if ImplIntf.VtblImplIntf<>ImplIntf then
              ImplIntf.IOffset:=ImplIntf.VtblImplIntf.IOffset;
          end;
      end;


    procedure TVMTBuilder.generate_vmt;
      var
        i : longint;
        def : tdef;
        ImplIntf : TImplementedInterface;
        old_current_objectdef : tobjectdef;
      begin
        old_current_objectdef:=current_objectdef;
        current_objectdef:=_class;

        _class.resetvmtentries;

        { inherit (copy) VMT from parent object }
        if assigned(_class.childof) then
          begin
            if not assigned(_class.childof.vmtentries) then
              internalerror(200810281);
            _class.copyvmtentries(_class.childof);
          end;

        { process all procdefs, we must process the defs to
          keep the same order as that is written in the source
          to be compatible with the indexes in the interface vtable (PFV) }
        for i:=0 to _class.symtable.DefList.Count-1 do
          begin
            def:=tdef(_class.symtable.DefList[i]);
            if def.typ=procdef then
              begin
                { VMT entry }
                if is_new_vmt_entry(tprocdef(def)) then
                  add_new_vmt_entry(tprocdef(def));
              end;
          end;

        { Find Procdefs implementing the interfaces }
        if assigned(_class.ImplementedInterfaces) then
          begin
            { Collect implementor functions into the tImplementedInterface.procdefs }
            for i:=0 to _class.ImplementedInterfaces.count-1 do
              begin
                ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
                intf_get_procdefs_recursive(ImplIntf,ImplIntf.IntfDef);
              end;
            { Optimize interface tables to reuse wrappers }
            intf_optimize_vtbls;
            { Allocate interface tables }
            intf_allocate_vtbls;
          end;

        current_objectdef:=old_current_objectdef;
      end;


{*****************************************************************************
                                TVMTWriter
*****************************************************************************}

    constructor TVMTWriter.create(c:tobjectdef);
      begin
        inherited Create;
        _Class:=c;
      end;


    destructor TVMTWriter.destroy;
      begin
      end;


{**************************************
           Message Tables
**************************************}

    procedure TVMTWriter.disposeprocdeftree(p : pprocdeftree);
      begin
         if assigned(p^.l) then
           disposeprocdeftree(p^.l);
         if assigned(p^.r) then
           disposeprocdeftree(p^.r);
         dispose(p);
      end;


    procedure TVMTWriter.insertint(p : pprocdeftree;var at : pprocdeftree;var count:longint);
      begin
         if at=nil then
           begin
              at:=p;
              inc(count);
           end
         else
           begin
              if p^.data.messageinf.i<at^.data.messageinf.i then
                insertint(p,at^.l,count)
              else if p^.data.messageinf.i>at^.data.messageinf.i then
                insertint(p,at^.r,count)
              else
                Message1(parser_e_duplicate_message_label,tostr(p^.data.messageinf.i));
           end;
      end;


    procedure TVMTWriter.insertstr(p : pprocdeftree;var at : pprocdeftree;var count:longint);
      var
         i : integer;
      begin
         if at=nil then
           begin
              at:=p;
              inc(count);
           end
         else
           begin
              i:=CompareStr(p^.data.messageinf.str^,at^.data.messageinf.str^);
              if i<0 then
                insertstr(p,at^.l,count)
              else if i>0 then
                insertstr(p,at^.r,count)
              else
                Message1(parser_e_duplicate_message_label,p^.data.messageinf.str^);
           end;
      end;


    procedure TVMTWriter.insertmsgint(p:TObject;arg:pointer);
      var
        i  : longint;
        pd : Tprocdef;
        pt : pprocdeftree;
      begin
        if tsym(p).typ<>procsym then
          exit;
        for i:=0 to Tprocsym(p).ProcdefList.Count-1 do
          begin
            pd:=tprocdef(Tprocsym(p).ProcdefList[i]);
            if po_msgint in pd.procoptions then
              begin
                new(pt);
                pt^.data:=pd;
                pt^.l:=nil;
                pt^.r:=nil;
                insertint(pt,root,plongint(arg)^);
              end;
          end;
      end;


    procedure TVMTWriter.insertmsgstr(p:TObject;arg:pointer);
      var
        i  : longint;
        pd : Tprocdef;
        pt : pprocdeftree;
      begin
        if tsym(p).typ<>procsym then
          exit;
        for i:=0 to Tprocsym(p).ProcdefList.Count-1 do
          begin
            pd:=tprocdef(Tprocsym(p).ProcdefList[i]);
            if po_msgstr in pd.procoptions then
              begin
                new(pt);
                pt^.data:=pd;
                pt^.l:=nil;
                pt^.r:=nil;
                insertstr(pt,root,plongint(arg)^);
              end;
          end;
      end;


    procedure TVMTWriter.writenames(p : pprocdeftree);
      var
        ca : pchar;
        len : byte;
      begin
         current_asmdata.getdatalabel(p^.nl);
         if assigned(p^.l) then
           writenames(p^.l);
         current_asmdata.asmlists[al_globals].concat(cai_align.create(const_align(sizeof(pint))));
         current_asmdata.asmlists[al_globals].concat(Tai_label.Create(p^.nl));
         len:=length(p^.data.messageinf.str^);
         current_asmdata.asmlists[al_globals].concat(tai_const.create_8bit(len));
         getmem(ca,len+1);
         move(p^.data.messageinf.str^[1],ca^,len);
         ca[len]:=#0;
         current_asmdata.asmlists[al_globals].concat(Tai_string.Create_pchar(ca,len));
         if assigned(p^.r) then
           writenames(p^.r);
      end;

    procedure TVMTWriter.writestrentry(p : pprocdeftree);

      begin
         if assigned(p^.l) then
           writestrentry(p^.l);

         { write name label }
         current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(p^.nl));
         current_asmdata.asmlists[al_globals].concat(Tai_const.Createname(p^.data.mangledname,0));

         if assigned(p^.r) then
           writestrentry(p^.r);
     end;


    function TVMTWriter.genstrmsgtab : tasmlabel;
      var
         count : aint;
      begin
         root:=nil;
         count:=0;
         { insert all message handlers into a tree, sorted by name }
         _class.symtable.SymList.ForEachCall(@insertmsgstr,@count);

         { write all names }
         if assigned(root) then
           writenames(root);

         { now start writing of the message string table }
         current_asmdata.getdatalabel(result);
         current_asmdata.asmlists[al_globals].concat(cai_align.create(const_align(sizeof(pint))));
         current_asmdata.asmlists[al_globals].concat(Tai_label.Create(result));
         current_asmdata.asmlists[al_globals].concat(Tai_const.Create_pint(count));
         if assigned(root) then
           begin
              writestrentry(root);
              disposeprocdeftree(root);
           end;
      end;


    procedure TVMTWriter.writeintentry(p : pprocdeftree);
      begin
         if assigned(p^.l) then
           writeintentry(p^.l);

         { write name label }
         current_asmdata.asmlists[al_globals].concat(Tai_const.Create_32bit(p^.data.messageinf.i));
         current_asmdata.asmlists[al_globals].concat(Tai_const.Createname(p^.data.mangledname,0));

         if assigned(p^.r) then
           writeintentry(p^.r);
      end;


    function TVMTWriter.genintmsgtab : tasmlabel;
      var
         r : tasmlabel;
         count : longint;
      begin
         root:=nil;
         count:=0;
         { insert all message handlers into a tree, sorted by name }
         _class.symtable.SymList.ForEachCall(@insertmsgint,@count);

         { now start writing of the message string table }
         current_asmdata.getdatalabel(r);
         current_asmdata.asmlists[al_globals].concat(cai_align.create(const_align(sizeof(pint))));
         current_asmdata.asmlists[al_globals].concat(Tai_label.Create(r));
         genintmsgtab:=r;
         current_asmdata.asmlists[al_globals].concat(Tai_const.Create_32bit(count));
         if assigned(root) then
           begin
              writeintentry(root);
              disposeprocdeftree(root);
           end;
      end;

{$ifdef WITHDMT}

{**************************************
              DMT
**************************************}

    procedure TVMTWriter.insertdmtentry(p:TObject;arg:pointer);

      var
         hp : tprocdef;
         pt : pprocdeftree;

      begin
         if tsym(p).typ=procsym then
           begin
              hp:=tprocsym(p).definition;
              while assigned(hp) do
                begin
                   if (po_msgint in hp.procoptions) then
                     begin
                        new(pt);
                        pt^.p:=hp;
                        pt^.l:=nil;
                        pt^.r:=nil;
                        insertint(pt,root);
                     end;
                   hp:=hp.nextoverloaded;
                end;
           end;
      end;

    procedure TVMTWriter.writedmtindexentry(p : pprocdeftree);

      begin
         if assigned(p^.l) then
           writedmtindexentry(p^.l);
         al_globals.concat(Tai_const.Create_32bit(p^.data.messageinf.i));
         if assigned(p^.r) then
           writedmtindexentry(p^.r);
      end;

    procedure TVMTWriter.writedmtaddressentry(p : pprocdeftree);

      begin
         if assigned(p^.l) then
           writedmtaddressentry(p^.l);
         al_globals.concat(Tai_const_symbol.Createname(p^.data.mangledname,0));
         if assigned(p^.r) then
           writedmtaddressentry(p^.r);
      end;

    function TVMTWriter.gendmt : tasmlabel;

      var
         r : tasmlabel;

      begin
         root:=nil;
         count:=0;
         gendmt:=nil;
         { insert all message handlers into a tree, sorted by number }
         _class.symtable.SymList.ForEachCall(insertdmtentry);

         if count>0 then
           begin
              current_asmdata.getdatalabel(r);
              gendmt:=r;
              al_globals.concat(cai_align.create(const_align(sizeof(pint))));
              al_globals.concat(Tai_label.Create(r));
              { entries for caching }
              al_globals.concat(Tai_const.Create_ptr(0));
              al_globals.concat(Tai_const.Create_ptr(0));

              al_globals.concat(Tai_const.Create_32bit(count));
              if assigned(root) then
                begin
                   writedmtindexentry(root);
                   writedmtaddressentry(root);
                   disposeprocdeftree(root);
                end;
           end;
      end;

{$endif WITHDMT}

{**************************************
        Published Methods
**************************************}

    procedure TVMTWriter.do_count_published_methods(p:TObject;arg:pointer);
      var
        i  : longint;
        pd : tprocdef;
      begin
        if (tsym(p).typ<>procsym) then
          exit;
        for i:=0 to Tprocsym(p).ProcdefList.Count-1 do
          begin
            pd:=tprocdef(Tprocsym(p).ProcdefList[i]);
            if (pd.procsym=tsym(p)) and
               (pd.visibility=vis_published) then
              inc(plongint(arg)^);
          end;
      end;


    procedure TVMTWriter.do_gen_published_methods(p:TObject;arg:pointer);
      var
        i  : longint;
        l  : tasmlabel;
        pd : tprocdef;
      begin
        if (tsym(p).typ<>procsym) then
          exit;
        for i:=0 to Tprocsym(p).ProcdefList.Count-1 do
          begin
            pd:=tprocdef(Tprocsym(p).ProcdefList[i]);
            if (pd.procsym=tsym(p)) and
               (pd.visibility=vis_published) then
              begin
                current_asmdata.getdatalabel(l);

                current_asmdata.asmlists[al_typedconsts].concat(cai_align.create(const_align(sizeof(pint))));
                current_asmdata.asmlists[al_typedconsts].concat(Tai_label.Create(l));
                current_asmdata.asmlists[al_typedconsts].concat(Tai_const.Create_8bit(length(tsym(p).realname)));
                current_asmdata.asmlists[al_typedconsts].concat(Tai_string.Create(tsym(p).realname));

                current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(l));
                if po_abstractmethod in pd.procoptions then
                  current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil))
                else
                  current_asmdata.asmlists[al_globals].concat(Tai_const.Createname(pd.mangledname,0));
              end;
           end;
      end;


    function TVMTWriter.genpublishedmethodstable : tasmlabel;

      var
         l : tasmlabel;
         count : longint;

      begin
         count:=0;
         _class.symtable.SymList.ForEachCall(@do_count_published_methods,@count);
         if count>0 then
           begin
              current_asmdata.getdatalabel(l);
              current_asmdata.asmlists[al_globals].concat(cai_align.create(const_align(sizeof(pint))));
              current_asmdata.asmlists[al_globals].concat(Tai_label.Create(l));
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_32bit(count));
              _class.symtable.SymList.ForEachCall(@do_gen_published_methods,nil);
              genpublishedmethodstable:=l;
           end
         else
           genpublishedmethodstable:=nil;
      end;


    function TVMTWriter.generate_field_table : tasmlabel;
      var
        i   : longint;
        sym : tsym;
        fieldtable,
        classtable : tasmlabel;
        classindex,
        fieldcount : longint;
        classtablelist : TFPList;
      begin
        classtablelist:=TFPList.Create;
        current_asmdata.getdatalabel(fieldtable);
        current_asmdata.getdatalabel(classtable);
        maybe_new_object_file(current_asmdata.asmlists[al_rtti]);
        new_section(current_asmdata.asmlists[al_rtti],sec_rodata,classtable.name,const_align(sizeof(pint)));

        { retrieve field info fields }
        fieldcount:=0;
        for i:=0 to _class.symtable.SymList.Count-1 do
          begin
            sym:=tsym(_class.symtable.SymList[i]);
            if (sym.typ=fieldvarsym) and
               (sym.visibility=vis_published) then
             begin
                if tfieldvarsym(sym).vardef.typ<>objectdef then
                  internalerror(200611032);
                classindex:=classtablelist.IndexOf(tfieldvarsym(sym).vardef);
                if classindex=-1 then
                  classtablelist.Add(tfieldvarsym(sym).vardef);
                inc(fieldcount);
             end;
          end;

        { write fields }
        current_asmdata.asmlists[al_rtti].concat(Tai_label.Create(fieldtable));
        current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_16bit(fieldcount));
        if (tf_requires_proper_alignment in target_info.flags) then
          current_asmdata.asmlists[al_rtti].concat(cai_align.Create(sizeof(TConstPtrUInt)));
        current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_sym(classtable));
        for i:=0 to _class.symtable.SymList.Count-1 do
          begin
            sym:=tsym(_class.symtable.SymList[i]);
            if (sym.typ=fieldvarsym) and
               (sym.visibility=vis_published) then
              begin
                if (tf_requires_proper_alignment in target_info.flags) then
                  current_asmdata.asmlists[al_rtti].concat(cai_align.Create(sizeof(pint)));
                current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_pint(tfieldvarsym(sym).fieldoffset));
                classindex:=classtablelist.IndexOf(tfieldvarsym(sym).vardef);
                if classindex=-1 then
                  internalerror(200611033);
                current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_16bit(classindex+1));
                current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_8bit(length(tfieldvarsym(sym).realname)));
                current_asmdata.asmlists[al_rtti].concat(Tai_string.Create(tfieldvarsym(sym).realname));
              end;
          end;

        { generate the class table }
        current_asmdata.asmlists[al_rtti].concat(cai_align.create(const_align(sizeof(pint))));
        current_asmdata.asmlists[al_rtti].concat(Tai_label.Create(classtable));
        current_asmdata.asmlists[al_rtti].concat(Tai_const.Create_16bit(classtablelist.count));
        if (tf_requires_proper_alignment in target_info.flags) then
          current_asmdata.asmlists[al_rtti].concat(cai_align.Create(sizeof(TConstPtrUInt)));
        for i:=0 to classtablelist.Count-1 do
          current_asmdata.asmlists[al_rtti].concat(Tai_const.Createname(tobjectdef(classtablelist[i]).vmt_mangledname,0));

        classtablelist.free;
        result:=fieldtable;
      end;


{**************************************
           Interface tables
**************************************}

    function  TVMTWriter.intf_get_vtbl_name(AImplIntf:TImplementedInterface): string;
      begin
        result:=make_mangledname('VTBL',_class.owner,_class.objname^+'_$_'+AImplIntf.IntfDef.objname^);
      end;


    procedure TVMTWriter.intf_create_vtbl(rawdata: TAsmList;AImplIntf:TImplementedInterface);
      var
        pd : tprocdef;
        vtblstr,
        hs : string;
        i  : longint;
      begin
        vtblstr:=intf_get_vtbl_name(AImplIntf);
        section_symbol_start(rawdata,vtblstr,AT_DATA,true,sec_data,const_align(sizeof(pint)));
        if assigned(AImplIntf.procdefs) then
          begin
            for i:=0 to AImplIntf.procdefs.count-1 do
              begin
                pd:=tprocdef(AImplIntf.procdefs[i]);
                hs:=make_mangledname('WRPR',_class.owner,_class.objname^+'_$_'+AImplIntf.IntfDef.objname^+'_$_'+
                                     tostr(i)+'_$_'+pd.mangledname);
                { create reference }
                rawdata.concat(Tai_const.Createname(hs,0));
              end;
           end;
        section_symbol_end(rawdata,vtblstr);
      end;


    procedure TVMTWriter.intf_gen_intf_ref(rawdata: TAsmList;AImplIntf:TImplementedInterface);
      var
        iidlabel,
        guidlabel : tasmlabel;
        i: longint;
      begin
        { GUID }
        if AImplIntf.IntfDef.objecttype in [odt_interfacecom] then
          begin
            { label for GUID }
            current_asmdata.getdatalabel(guidlabel);
            rawdata.concat(cai_align.create(const_align(sizeof(pint))));
            rawdata.concat(Tai_label.Create(guidlabel));
            with AImplIntf.IntfDef.iidguid^ do
              begin
                rawdata.concat(Tai_const.Create_32bit(longint(D1)));
                rawdata.concat(Tai_const.Create_16bit(D2));
                rawdata.concat(Tai_const.Create_16bit(D3));
                for i:=Low(D4) to High(D4) do
                  rawdata.concat(Tai_const.Create_8bit(D4[i]));
              end;
            current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(guidlabel));
          end
        else
          begin
            { nil for Corba interfaces }
            current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
          end;
        { VTable }
        current_asmdata.asmlists[al_globals].concat(Tai_const.Createname(intf_get_vtbl_name(AImplIntf.VtblImplIntf),0));
        { IOffset field }
        case AImplIntf.VtblImplIntf.IType of
          etFieldValue,
          etStandard:
            current_asmdata.asmlists[al_globals].concat(Tai_const.Create_pint(AImplIntf.VtblImplIntf.IOffset));
          etVirtualMethodResult,
          etStaticMethodResult:
            current_asmdata.asmlists[al_globals].concat(Tai_const.Create_pint(0));
          else
            internalerror(200802162);
        end;

        { IIDStr }
        current_asmdata.getdatalabel(iidlabel);
        rawdata.concat(cai_align.create(const_align(sizeof(pint))));
        rawdata.concat(Tai_label.Create(iidlabel));
        rawdata.concat(Tai_const.Create_8bit(length(AImplIntf.IntfDef.iidstr^)));
        if AImplIntf.IntfDef.objecttype=odt_interfacecom then
          rawdata.concat(Tai_string.Create(upper(AImplIntf.IntfDef.iidstr^)))
        else
          rawdata.concat(Tai_string.Create(AImplIntf.IntfDef.iidstr^));
        current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(iidlabel));
        { IType }
        current_asmdata.asmlists[al_globals].concat(Tai_const.Create_pint(aint(AImplIntf.VtblImplIntf.IType)));
      end;


    function TVMTWriter.intf_write_table:TAsmLabel;
      var
        rawdata  : TAsmList;
        i        : longint;
        ImplIntf : TImplementedInterface;
        intftablelab : tasmlabel;
      begin
        current_asmdata.getdatalabel(intftablelab);
        current_asmdata.asmlists[al_globals].concat(cai_align.create(const_align(sizeof(pint))));
        current_asmdata.asmlists[al_globals].concat(Tai_label.Create(intftablelab));
        current_asmdata.asmlists[al_globals].concat(Tai_const.Create_pint(_class.ImplementedInterfaces.count));
        rawdata:=TAsmList.Create;
        { Write vtbls }
        for i:=0 to _class.ImplementedInterfaces.count-1 do
          begin
            ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
            if ImplIntf.VtblImplIntf=ImplIntf then
              intf_create_vtbl(rawdata,ImplIntf);
          end;
        { Write vtbl references }
        for i:=0 to _class.ImplementedInterfaces.count-1 do
          begin
            ImplIntf:=TImplementedInterface(_class.ImplementedInterfaces[i]);
            intf_gen_intf_ref(rawdata,ImplIntf);
          end;
        { Write interface table }
        current_asmdata.asmlists[al_globals].concatlist(rawdata);
        rawdata.free;
        result:=intftablelab;
      end;


  { Write interface identifiers to the data section }
  procedure TVMTWriter.writeinterfaceids;
    var
      i : longint;
      s : string;
    begin
      if assigned(_class.iidguid) then
        begin
          s:=make_mangledname('IID',_class.owner,_class.objname^);
          maybe_new_object_file(current_asmdata.asmlists[al_globals]);
          new_section(current_asmdata.asmlists[al_globals],sec_rodata,s,const_align(sizeof(pint)));
          current_asmdata.asmlists[al_globals].concat(Tai_symbol.Createname_global(s,AT_DATA,0));
          current_asmdata.asmlists[al_globals].concat(Tai_const.Create_32bit(longint(_class.iidguid^.D1)));
          current_asmdata.asmlists[al_globals].concat(Tai_const.Create_16bit(_class.iidguid^.D2));
          current_asmdata.asmlists[al_globals].concat(Tai_const.Create_16bit(_class.iidguid^.D3));
          for i:=Low(_class.iidguid^.D4) to High(_class.iidguid^.D4) do
            current_asmdata.asmlists[al_globals].concat(Tai_const.Create_8bit(_class.iidguid^.D4[i]));
        end;
      maybe_new_object_file(current_asmdata.asmlists[al_globals]);
      s:=make_mangledname('IIDSTR',_class.owner,_class.objname^);
      new_section(current_asmdata.asmlists[al_globals],sec_rodata,s,0);
      current_asmdata.asmlists[al_globals].concat(Tai_symbol.Createname_global(s,AT_DATA,0));
      current_asmdata.asmlists[al_globals].concat(Tai_const.Create_8bit(length(_class.iidstr^)));
      current_asmdata.asmlists[al_globals].concat(Tai_string.Create(_class.iidstr^));
    end;


    procedure TVMTWriter.writevirtualmethods(List:TAsmList);
      var
         vmtpd : tprocdef;
         vmtentry : pvmtentry;
         i  : longint;
         procname : string;
{$ifdef vtentry}
         hs : string;
{$endif vtentry}
      begin
        if not assigned(_class.VMTEntries) then
          exit;
        for i:=0 to _class.VMTEntries.Count-1 do
         begin
           vmtentry:=pvmtentry(_class.vmtentries[i]);
           vmtpd:=vmtentry^.procdef;
           { safety checks }
           if not(po_virtualmethod in vmtpd.procoptions) then
             internalerror(200611082);
           if vmtpd.extnumber<>i then
             internalerror(200611083);
           if (po_abstractmethod in vmtpd.procoptions) then
             procname:='FPC_ABSTRACTERROR'
           else if not wpoinfomanager.optimized_name_for_vmt(_class,vmtpd,procname) then
             procname:=vmtpd.mangledname;
           List.concat(Tai_const.createname(procname,0));
{$ifdef vtentry}
           hs:='VTENTRY'+'_'+_class.vmt_mangledname+'$$'+tostr(_class.vmtmethodoffset(i) div sizeof(pint));
           current_asmdata.asmlists[al_globals].concat(tai_symbol.CreateName(hs,AT_DATA,0));
{$endif vtentry}
         end;
      end;


    procedure TVMTWriter.writevmt;
      var
         methodnametable,intmessagetable,
         strmessagetable,classnamelabel,
         fieldtablelabel : tasmlabel;
{$ifdef WITHDMT}
         dmtlabel : tasmlabel;
{$endif WITHDMT}
         interfacetable : tasmlabel;
{$ifdef vtentry}
         hs: string;
{$endif vtentry}
      begin
{$ifdef WITHDMT}
         dmtlabel:=gendmt;
{$endif WITHDMT}

         { write tables for classes, this must be done before the actual
           class is written, because we need the labels defined }
         if is_class(_class) then
          begin
            current_asmdata.getdatalabel(classnamelabel);
            maybe_new_object_file(current_asmdata.asmlists[al_globals]);
            new_section(current_asmdata.asmlists[al_globals],sec_rodata,classnamelabel.name,const_align(sizeof(pint)));

            { interface table }
            if _class.ImplementedInterfaces.count>0 then
              interfacetable:=intf_write_table;

            methodnametable:=genpublishedmethodstable;
            fieldtablelabel:=generate_field_table;
            { write class name }
            current_asmdata.asmlists[al_globals].concat(Tai_label.Create(classnamelabel));
            current_asmdata.asmlists[al_globals].concat(Tai_const.Create_8bit(length(_class.objrealname^)));
            current_asmdata.asmlists[al_globals].concat(Tai_string.Create(_class.objrealname^));

            { generate message and dynamic tables }
            if (oo_has_msgstr in _class.objectoptions) then
              strmessagetable:=genstrmsgtab;
            if (oo_has_msgint in _class.objectoptions) then
              intmessagetable:=genintmsgtab;
          end;

        { write debug info }
        maybe_new_object_file(current_asmdata.asmlists[al_globals]);
        new_section(current_asmdata.asmlists[al_globals],sec_rodata,_class.vmt_mangledname,const_align(sizeof(pint)));
        current_asmdata.asmlists[al_globals].concat(Tai_symbol.Createname_global(_class.vmt_mangledname,AT_DATA,0));

         { determine the size with symtable.datasize, because }
         { size gives back 4 for classes                    }
         current_asmdata.asmlists[al_globals].concat(Tai_const.Create(aitconst_ptr,tObjectSymtable(_class.symtable).datasize));
         current_asmdata.asmlists[al_globals].concat(Tai_const.Create(aitconst_ptr,-int64(tObjectSymtable(_class.symtable).datasize)));
{$ifdef WITHDMT}
         if _class.classtype=ct_object then
           begin
              if assigned(dmtlabel) then
                current_asmdata.asmlists[al_globals].concat(Tai_const_symbol.Create(dmtlabel)))
              else
                current_asmdata.asmlists[al_globals].concat(Tai_const.Create_ptr(0));
           end;
{$endif WITHDMT}
         { write pointer to parent VMT, this isn't implemented in TP }
         { but this is not used in FPC ? (PM) }
         { it's not used yet, but the delphi-operators as and is need it (FK) }
         { it is not written for parents that don't have any vmt !! }
         if assigned(_class.childof) and
            (oo_has_vmt in _class.childof.objectoptions) then
           current_asmdata.asmlists[al_globals].concat(Tai_const.Createname(_class.childof.vmt_mangledname,0))
         else
           current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));

         { write extended info for classes, for the order see rtl/inc/objpash.inc }
         if is_class(_class) then
          begin
            { pointer to class name string }
            current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(classnamelabel));
            { pointer to dynamic table or nil }
            if (oo_has_msgint in _class.objectoptions) then
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(intmessagetable))
            else
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
            { pointer to method table or nil }
            current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(methodnametable));
            { pointer to field table }
            current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(fieldtablelabel));
            { pointer to type info of published section }
            if (oo_can_have_published in _class.objectoptions) then
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(RTTIWriter.get_rtti_label(_class,fullrtti)))
            else
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
            { inittable for con-/destruction }
            if _class.members_need_inittable then
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(RTTIWriter.get_rtti_label(_class,initrtti)))
            else
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
            { auto table }
            current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
            { interface table }
            if _class.ImplementedInterfaces.count>0 then
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(interfacetable))
            else if _class.implements_any_interfaces then
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil))
            else
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(current_asmdata.RefAsmSymbol('FPC_EMPTYINTF')));
            { table for string messages }
            if (oo_has_msgstr in _class.objectoptions) then
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(strmessagetable))
            else
              current_asmdata.asmlists[al_globals].concat(Tai_const.Create_sym(nil));
          end;
         { write virtual methods }
         writevirtualmethods(current_asmdata.asmlists[al_globals]);
         current_asmdata.asmlists[al_globals].concat(Tai_const.create(aitconst_ptr,0));
         { write the size of the VMT }
         current_asmdata.asmlists[al_globals].concat(Tai_symbol_end.Createname(_class.vmt_mangledname));
{$ifdef vtentry}
         { write vtinherit symbol to notify the linker of the class inheritance tree }
         hs:='VTINHERIT'+'_'+_class.vmt_mangledname+'$$';
         if assigned(_class.childof) then
           hs:=hs+_class.childof.vmt_mangledname
         else
           hs:=hs+_class.vmt_mangledname;
         current_asmdata.asmlists[al_globals].concat(tai_symbol.CreateName(hs,AT_DATA,0));
{$endif vtentry}
      end;


end.