{
    Copyright (c) 2003-2004 by Peter Vreman and Florian Klaempfl

    This units contains support for STABS debug info generation

    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 dbgstabs;

{$i fpcdefs.inc}

interface

    uses
      cclasses,
      dbgbase,
      symtype,symdef,symsym,symtable,symbase,
      aasmtai,aasmdata;

    const
      { stab types }
      N_GSYM = $20;
      N_STSYM = 38;     { initialized const }
      N_LCSYM = 40;     { non initialized variable}
      N_Function = $24; { function or const }
      N_TextLine = $44;
      N_DataLine = $46;
      N_BssLine = $48;
      N_RSYM = $40;     { register variable }
      N_LSYM = $80;
      N_tsym = 160;
      N_SourceFile = $64;
{ APPLE LOCAL N_OSO: This is the stab that associated the .o file with the
   N_SO stab, in the case where debug info is mostly stored in the .o file.  }
      N_OSO        = $66;
      N_IncludeFile = $84;
      N_BINCL = $82;
      N_EINCL = $A2;
      N_LBRAC = $C0;
      N_EXCL  = $C2;
      N_RBRAC = $E0;

    type
      TDebugInfoStabs=class(TDebugInfo)
      private
        writing_def_stabs  : boolean;
        global_stab_number : word;
        defnumberlist      : TFPObjectList;
        { tsym writing }
        function  sym_var_value(const s:string;arg:pointer):string;
        function  sym_stabstr_evaluate(sym:tsym;const s:string;const vars:array of string):ansistring;
        procedure write_sym_stabstr(list:TAsmList;sym:tsym;const ss:ansistring);
        procedure appendsym_staticvar(list:TAsmList;sym:tstaticvarsym);override;
        procedure appendsym_paravar(list:TAsmList;sym:tparavarsym);override;
        procedure appendsym_localvar(list:TAsmList;sym:tlocalvarsym);override;
        procedure appendsym_fieldvar(list:TAsmList;sym:tfieldvarsym);override;
        procedure appendsym_const(list:TAsmList;sym:tconstsym);override;
        procedure appendsym_type(list:TAsmList;sym:ttypesym);override;
        procedure appendsym_label(list:TAsmList;sym:tlabelsym);override;
        { tdef writing }
        function  def_stab_number(def:tdef):string;
        function  def_stab_classnumber(def:tobjectdef):string;
        function  def_var_value(const s:string;arg:pointer):string;
        function  def_stabstr_evaluate(def:tdef;const s:string;const vars:array of string):ansistring;
        procedure write_def_stabstr(list:TAsmList;def:tdef;const ss:ansistring);
        procedure field_add_stabstr(p:TObject;arg:pointer);
        procedure method_add_stabstr(p:TObject;arg:pointer);
        procedure field_write_defs(p:TObject;arg:pointer);
        procedure beforeappenddef(list:TAsmList;def:tdef);override;
        procedure appenddef_ord(list:TAsmList;def:torddef);override;
        procedure appenddef_float(list:TAsmList;def:tfloatdef);override;
        procedure appenddef_file(list:TAsmList;def:tfiledef);override;
        procedure appenddef_enum(list:TAsmList;def:tenumdef);override;
        procedure appenddef_array(list:TAsmList;def:tarraydef);override;
        procedure appenddef_record(list:TAsmList;def:trecorddef);override;
        procedure appenddef_object(list:TAsmList;def:tobjectdef);override;
        procedure appenddef_pointer(list:TAsmList;def:tpointerdef);override;
        procedure appenddef_string(list:TAsmList;def:tstringdef);override;
        procedure appenddef_procvar(list:TAsmList;def:tprocvardef);override;
        procedure appenddef_variant(list:TAsmList;def:tvariantdef);override;
        procedure appenddef_set(list:TAsmList;def:tsetdef);override;
        procedure appenddef_formal(list:TAsmList;def:tformaldef);override;
        procedure appenddef_undefined(list:TAsmList;def: tundefineddef);override;
        procedure appendprocdef(list:TAsmList;def:tprocdef);override;
      public
        procedure inserttypeinfo;override;
        procedure insertmoduleinfo;override;
        procedure insertlineinfo(list:TAsmList);override;
        procedure referencesections(list:TAsmList);override;
      end;


implementation

    uses
      SysUtils,cutils,cfileutl,
      systems,globals,globtype,verbose,constexp,
      symconst,defutil,
      cpuinfo,cpubase,cgbase,paramgr,
      aasmbase,procinfo,
      finput,fmodule,ppu;

    function GetSymName(Sym : TSymEntry) : string;
    begin
      if Not (cs_stabs_preservecase in current_settings.globalswitches) then
        result := Sym.Name
      else
        result := Sym.RealName;
    end;

    function GetSymTableName(SymTable : TSymTable) : string;
    begin
      if Not (cs_stabs_preservecase in current_settings.globalswitches) then
        result := SymTable.Name^
      else
        result := SymTable.RealName^;
    end;

    const
      memsizeinc = 512;

      tagtypes = [
        recorddef,
        enumdef,
        stringdef,
        filedef,
        objectdef
      ];

    type
       get_var_value_proc=function(const s:string;arg:pointer):string of object;


    function string_evaluate(s:string;get_var_value:get_var_value_proc;get_var_value_arg:pointer;const vars:array of string):ansistring;
    (*
     S contains a prototype of a result. Stabstr_evaluate will expand
     variables and parameters.

     Output is s in ASCIIZ format, with the following expanded:

     ${varname}   - The variable name is expanded.
     $n           - The parameter n is expanded.
     $$           - Is expanded to $
    *)

    const maxvalue=9;
          maxdata=1023;

    var i,j:byte;
        varname:string[63];
        varno,varcounter:byte;
        varvalues:array[0..9] of pshortstring;
        {1 kb of parameters is the limit. 256 extra bytes are allocated to
         ensure buffer integrity.}
        varvaluedata:array[0..maxdata+256] of char;
        varptr:Pchar;
        varidx : byte;
        len:longint;
        r:Pchar;

    begin
      {Two pass approach, first, calculate the length and receive variables.}
      i:=1;
      len:=0;
      varcounter:=0;
      varptr:=@varvaluedata[0];
      while i<=length(s) do
        begin
          if (s[i]='$') and (i<length(s)) then
            begin
             if s[i+1]='$' then
               begin
                 inc(len);
                 inc(i);
               end
             else if (s[i+1]='{') and (length(s)>2) and (i<length(s)-2) then
               begin
                 varname:='';
                 inc(i,2);
                 repeat
                   inc(varname[0]);
                   varname[length(varname)]:=s[i];
                   s[i]:=char(varcounter);
                   inc(i);
                 until s[i]='}';
                 varvalues[varcounter]:=pshortstring(varptr);
                 if varptr>@varvaluedata[maxdata] then
                   internalerrorproc(200411152);
                 pshortstring(varptr)^:=get_var_value(varname,get_var_value_arg);
                 inc(len,length(pshortstring(varptr)^));
                 inc(varptr,length(pshortstring(varptr)^)+1);
                 inc(varcounter);
               end
             else if s[i+1] in ['1'..'9'] then
               begin
                 varidx:=byte(s[i+1])-byte('1');
                 if varidx>high(vars) then
                   internalerror(200509263);
                 inc(len,length(vars[varidx]));
                 inc(i);
               end;
            end
          else
            inc(len);
          inc(i);
        end;

      {Second pass, writeout result.}
      setlength(result,len);
      r:=pchar(result);
      i:=1;
      while i<=length(s) do
        begin
          if (s[i]='$') and (i<length(s)) then
            begin
             if s[i+1]='$' then
               begin
                 r^:='$';
                 inc(r);
                 inc(i);
               end
             else if (s[i+1]='{') and (length(s)>2) and (i<length(s)-2) then
               begin
                 varname:='';
                 inc(i,2);
                 varno:=byte(s[i]);
                 repeat
                   inc(i);
                 until s[i]='}';
                 for j:=1 to length(varvalues[varno]^) do
                   begin
                     r^:=varvalues[varno]^[j];
                     inc(r);
                   end;
               end
             else if s[i+1] in ['0'..'9'] then
               begin
                 for j:=1 to length(vars[byte(s[i+1])-byte('1')]) do
                   begin
                     r^:=vars[byte(s[i+1])-byte('1')][j];
                     inc(r);
                   end;
                 inc(i);
               end
            end
          else
            begin
              r^:=s[i];
              inc(r);
            end;
          inc(i);
        end;
      { verify that the length was correct }
      if r^<>#0 then
        internalerror(200802031);
    end;


{****************************************************************************
                               TDef support
****************************************************************************}

    function TDebugInfoStabs.def_stab_number(def:tdef):string;
      begin
        { procdefs only need a number, mark them as already written
          so they won't be written implicitly }
        if (def.typ=procdef) then
          def.dbg_state:=dbg_state_written;

        { Stab must already be written, or we must be busy writing it }
        if writing_def_stabs and
           not(def.dbg_state in [dbg_state_writing,dbg_state_written,dbg_state_queued]) then
          internalerror(200403091);

        { Keep track of used stabs, this info is only usefull for stabs
          referenced by the symbols. Definitions will always include all
          required stabs }
        if def.dbg_state=dbg_state_unused then
          def.dbg_state:=dbg_state_used;
        { Need a new number? }
        if def.stab_number=0 then
          begin
            inc(global_stab_number);
            { classes require 2 numbers }
            if is_class(def) then
              inc(global_stab_number);
            def.stab_number:=global_stab_number;
            if global_stab_number>=defnumberlist.count then
              defnumberlist.count:=global_stab_number+250;
            defnumberlist[global_stab_number]:=def;
          end;
        result:=tostr(def.stab_number);
      end;


    function TDebugInfoStabs.def_stab_classnumber(def:tobjectdef):string;
      begin
        if def.stab_number=0 then
          def_stab_number(def);
        if (def.objecttype=odt_class) then
          result:=tostr(def.stab_number-1)
        else
          result:=tostr(def.stab_number);
      end;


    function TDebugInfoStabs.def_var_value(const s:string;arg:pointer):string;
      var
        def : tdef;
      begin
        def:=tdef(arg);
        result:='';
        if s='numberstring' then
          result:=def_stab_number(def)
        else if s='sym_name' then
          begin
            if assigned(def.typesym) then
               result:=GetSymName(Ttypesym(def.typesym));
          end
        else if s='N_LSYM' then
          result:=tostr(N_LSYM)
        else if s='savesize' then
          result:=tostr(def.size);
      end;


    function TDebugInfoStabs.def_stabstr_evaluate(def:tdef;const s:string;const vars:array of string):ansistring;
      begin
        result:=string_evaluate(s,@def_var_value,def,vars);
      end;


    procedure TDebugInfoStabs.field_add_stabstr(p:TObject;arg:pointer);
      var
        spec    : string[3];
        varsize : aint;
        newss   : ansistring;
        ss      : pansistring absolute arg;
      begin
        { static variables from objects are like global objects }
        if (Tsym(p).typ=fieldvarsym) and
           not(sp_static in Tsym(p).symoptions) then
          begin
            if ([sp_protected,sp_strictprotected]*tsym(p).symoptions)<>[] then
              spec:='/1'
            else if ([sp_private,sp_strictprivate]*tsym(p).symoptions)<>[] then
              spec:='/0'
            else
              spec:='';
            if (tabstractrecordsymtable(tsym(p).owner).usefieldalignment<>bit_alignment) then
              begin
                varsize:=tfieldvarsym(p).vardef.size;
                { open arrays made overflows !! }
                { how can a record/object/class contain an open array? (JM) }
                if varsize>$fffffff then
                  varsize:=$fffffff;
                newss:=def_stabstr_evaluate(nil,'$1:$2,$3,$4;',[GetSymName(tfieldvarsym(p)),
                                     spec+def_stab_number(tfieldvarsym(p).vardef),
                                     tostr(TConstExprInt(tfieldvarsym(p).fieldoffset)*8),tostr(varsize*8)])
              end
            else
              newss:=def_stabstr_evaluate(nil,'$1:$2,$3,$4;',[GetSymName(tfieldvarsym(p)),
                                   spec+def_stab_number(tfieldvarsym(p).vardef),
                                   tostr(TConstExprInt(tfieldvarsym(p).fieldoffset)),tostr(tfieldvarsym(p).vardef.packedbitsize)]);
            ss^:=ss^+newss;
          end;
      end;


    procedure TDebugInfoStabs.method_add_stabstr(p:TObject;arg:pointer);
      var
        virtualind,argnames : string;
        pd     : tprocdef;
        lindex : longint;
        arglength : byte;
        sp : char;
        i : integer;
        parasym : tparavarsym;
        newss   : ansistring;
        ss      : pansistring absolute arg;
      begin
        if tsym(p).typ = procsym then
         begin
           pd :=tprocdef(tprocsym(p).ProcdefList[0]);
           if (po_virtualmethod in pd.procoptions) then
             begin
               lindex := pd.extnumber;
               {doesnt seem to be necessary
               lindex := lindex or $80000000;}
               virtualind := '*'+tostr(lindex)+';'+def_stab_classnumber(pd._class)+';'
             end
            else
             virtualind := '.';

            { used by gdbpas to recognize constructor and destructors }
            if (pd.proctypeoption=potype_constructor) then
              argnames:='__ct__'
            else if (pd.proctypeoption=potype_destructor) then
              argnames:='__dt__'
            else
              argnames := '';

           { arguments are not listed here }
           {we don't need another definition}
            for i:=0 to pd.paras.count-1 do
              begin
                parasym:=tparavarsym(pd.paras[i]);
                if Parasym.vardef.typ = formaldef then
                  begin
                    case Parasym.varspez of
                      vs_var :
                        argnames := argnames+'3var';
                      vs_const :
                        argnames:=argnames+'5const';
                      vs_out :
                        argnames:=argnames+'3out';
                    end;
                  end
                else
                  begin
                    { if the arg definition is like (v: ^byte;..
                    there is no sym attached to data !!! }
                    if assigned(Parasym.vardef.typesym) then
                      begin
                        arglength := length(GetSymName(Parasym.vardef.typesym));
                        argnames := argnames + tostr(arglength)+GetSymName(Parasym.vardef.typesym);
                      end
                    else
                      argnames:=argnames+'11unnamedtype';
                  end;
              end;
           { here 2A must be changed for private and protected }
           { 0 is private 1 protected and 2 public }
           if ([sp_private,sp_strictprivate]*tsym(p).symoptions)<>[] then
             sp:='0'
           else if ([sp_protected,sp_strictprotected]*tsym(p).symoptions)<>[] then
             sp:='1'
           else
             sp:='2';
           newss:=def_stabstr_evaluate(nil,'$1::$2=##$3;:$4;$5A$6;',[GetSymName(tsym(p)),def_stab_number(pd),
                                    def_stab_number(pd.returndef),argnames,sp,
                                    virtualind]);
           ss^:=ss^+newss;
         end;
      end;


    procedure TDebugInfoStabs.field_write_defs(p:TObject;arg:pointer);
      begin
        if (Tsym(p).typ=fieldvarsym) and
           not(sp_static in Tsym(p).symoptions) then
          appenddef(TAsmList(arg),tfieldvarsym(p).vardef);
      end;


    procedure TDebugInfoStabs.write_def_stabstr(list:TAsmList;def:tdef;const ss:ansistring);
      var
        stabchar : string[2];
        symname  : string[20];
        st    : ansistring;
        p     : pchar;
      begin
        { type prefix }
        if def.typ in tagtypes then
          stabchar := 'Tt'
        else
          stabchar := 't';
        { Type names for types defined in the current unit are already written in
          the typesym }
        if (def.owner.symtabletype=globalsymtable) and
           not(def.owner.iscurrentunit) then
          symname:='${sym_name}'
        else
          symname:='';
        { Here we maybe generate a type, so we have to use numberstring }
        if is_class(def) and
           tobjectdef(def).writing_class_record_dbginfo then
          st:=def_stabstr_evaluate(def,'"'+symname+':$1$2=',[stabchar,def_stab_classnumber(tobjectdef(def))])
        else
          st:=def_stabstr_evaluate(def,'"'+symname+':$1$2=',[stabchar,def_stab_number(def)]);
        st:=st+ss;
        { line info is set to 0 for all defs, because the def can be in an other
          unit and then the linenumber is invalid in the current sourcefile }
        st:=st+def_stabstr_evaluate(def,'",${N_LSYM},0,0,0',[]);
        { add to list }
        getmem(p,length(st)+1);
        move(pchar(st)^,p^,length(st)+1);
        list.concat(Tai_stab.create(stab_stabs,p));
      end;


    procedure TDebugInfoStabs.appenddef_string(list:TAsmList;def:tstringdef);
      var
        bytest,charst,longst : string;
        ss : ansistring;
        slen : longint;
      begin
        ss:='';
        case def.stringtype of
          st_shortstring:
            begin
              { fix length of openshortstring }
              slen:=def.len;
              if slen=0 then
                slen:=255;
              charst:=def_stab_number(cchartype);
              bytest:=def_stab_number(u8inttype);
              ss:=def_stabstr_evaluate(def,'s$1length:$2,0,8;st:ar$2;1;$3;$4,8,$5;;',
                          [tostr(slen+1),bytest,tostr(slen),charst,tostr(slen*8)]);
            end;
          st_longstring:
            begin
              charst:=def_stab_number(cchartype);
              bytest:=def_stab_number(u8inttype);
              longst:=def_stab_number(u32inttype);
              ss:=def_stabstr_evaluate(def,'s$1length:$2,0,32;dummy:$6,32,8;st:ar$2;1;$3;$4,40,$5;;',
                          [tostr(def.len+5),longst,tostr(def.len),charst,tostr(def.len*8),bytest]);
           end;
         st_ansistring:
           begin
             { looks like a pchar }
             ss:='*'+def_stab_number(cchartype);
           end;
         st_unicodestring,
         st_widestring:
           begin
             { looks like a pwidechar }
             ss:='*'+def_stab_number(cwidechartype);
           end;
        end;
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.appenddef_enum(list:TAsmList;def:tenumdef);
      var
        st : ansistring;
        p  : Tenumsym;
      begin
        { we can specify the size with @s<size>; prefix PM }
        if def.size <> std_param_align then
          st:='@s'+tostr(def.size*8)+';e'
        else
          st:='e';
        p := tenumsym(def.firstenum);
        while assigned(p) do
          begin
            st:=st+GetSymName(p)+':'+tostr(p.value)+',';
            p:=p.nextenum;
          end;
        { the final ',' is required to have a valid stabs }
        st:=st+';';
        write_def_stabstr(list,def,st);
      end;


    procedure TDebugInfoStabs.appenddef_ord(list:TAsmList;def:torddef);
      var
        ss : ansistring;
      begin
        ss:='';
        if cs_gdb_valgrind in current_settings.globalswitches then
          begin
            case def.ordtype of
              uvoid :
                ss:=strpnew(def_stab_number(def));
              pasbool,
              bool8bit,
              bool16bit,
              bool32bit,
              bool64bit :
                ss:=def_stabstr_evaluate(def,'r${numberstring};0;255;',[]);
              u32bit,
              s64bit,
              u64bit :
                ss:=def_stabstr_evaluate(def,'r${numberstring};0;-1;',[]);
              else
                ss:=def_stabstr_evaluate(def,'r${numberstring};$1;$2;',[tostr(longint(def.low.svalue)),tostr(longint(def.high.svalue))]);
            end;
          end
        else
          begin
            case def.ordtype of
              uvoid :
                ss:=strpnew(def_stab_number(def));
              uchar :
                ss:=strpnew('-20;');
              uwidechar :
                ss:=strpnew('-30;');
              pasbool,
              bool8bit :
                ss:=strpnew('-21;');
              bool16bit :
                ss:=strpnew('-22;');
              bool32bit :
                ss:=strpnew('-23;');
              bool64bit :
                { no clue if this is correct (FK) }
                ss:=strpnew('-23;');
              u64bit :
                ss:=strpnew('-32;');
              s64bit :
                ss:=strpnew('-31;');
              {u32bit : result:=def_stab_number(s32inttype)+';0;-1;'); }
              else
                ss:=def_stabstr_evaluate(def,'r${numberstring};$1;$2;',[tostr(longint(def.low.svalue)),tostr(longint(def.high.svalue))]);
            end;
         end;
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.appenddef_float(list:TAsmList;def:tfloatdef);
      var
        ss : ansistring;
      begin
        ss:='';
        case def.floattype of
          s32real,
          s64real,
          s80real:
            ss:=def_stabstr_evaluate(def,'r$1;${savesize};0;',[def_stab_number(s32inttype)]);
          s64currency,
          s64comp:
            ss:=def_stabstr_evaluate(def,'r$1;-${savesize};0;',[def_stab_number(s32inttype)]);
          else
            internalerror(200509261);
        end;
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.appenddef_file(list:TAsmList;def:tfiledef);
      var
        ss : ansistring;
      begin
{$ifdef cpu64bitaddr}
        ss:=def_stabstr_evaluate(def,'s${savesize}HANDLE:$1,0,32;MODE:$1,32,32;RECSIZE:$2,64,64;'+
                                 '_PRIVATE:ar$1;1;64;$3,128,256;USERDATA:ar$1;1;16;$3,384,128;'+
                                 'NAME:ar$1;0;255;$4,512,2048;;',[def_stab_number(s32inttype),
                                 def_stab_number(s64inttype),
                                 def_stab_number(u8inttype),
                                 def_stab_number(cchartype)]);
{$else cpu64bitaddr}
        ss:=def_stabstr_evaluate(def,'s${savesize}HANDLE:$1,0,32;MODE:$1,32,32;RECSIZE:$1,64,32;'+
                                 '_PRIVATE:ar$1;1;32;$3,96,256;USERDATA:ar$1;1;16;$2,352,128;'+
                                 'NAME:ar$1;0;255;$3,480,2048;;',[def_stab_number(s32inttype),
                                 def_stab_number(u8inttype),
                                 def_stab_number(cchartype)]);
{$endif cpu64bitaddr}
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.appenddef_record(list:TAsmList;def:trecorddef);
      var
        ss : ansistring;
      begin
        ss:='s'+tostr(def.size);
        def.symtable.SymList.ForEachCall(@field_add_stabstr,@ss);
        ss[length(ss)]:=';';
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.appenddef_object(list:TAsmList;def:tobjectdef);

        procedure do_write_object(list:TAsmList;def:tobjectdef);
        var
          ss : ansistring;
          anc    : tobjectdef;
        begin
          ss:='';
          { Write the invisible pointer for the class? }
          if (def.objecttype=odt_class) and
             (not def.writing_class_record_dbginfo) then
            begin
              ss:='*'+def_stab_classnumber(def);
              write_def_stabstr(list,def,ss);
              exit;
            end;

          ss:='s'+tostr(tobjecTSymtable(def.symtable).datasize);
          if assigned(def.childof) then
            begin
              {only one ancestor not virtual, public, at base offset 0 }
              {       !1           ,    0       2         0    ,       }
              ss:=ss+'!1,020,'+def_stab_classnumber(def.childof)+';';
            end;

          {virtual table to implement yet}
          def.symtable.symList.ForEachCall(@field_add_stabstr,@ss);

          if (oo_has_vmt in def.objectoptions) and
             (
              not assigned(def.childof) or
              not(oo_has_vmt in def.childof.objectoptions)
             ) then
            ss:=ss+'$vf'+def_stab_classnumber(def)+':'+def_stab_number(vmtarraytype)+','+tostr(def.vmt_offset*8)+';';
          def.symtable.symList.ForEachCall(@method_add_stabstr,@ss);
          if (oo_has_vmt in def.objectoptions) then
            begin
               anc := def;
               while assigned(anc.childof) and (oo_has_vmt in anc.childof.objectoptions) do
                 anc := anc.childof;
               { just in case anc = self }
               ss:=ss+';~%'+def_stab_classnumber(anc)+';';
            end
          else
            ss:=ss+';';
          write_def_stabstr(list,def,ss);
        end;

      var
        oldtypesym : tsym;
      begin
        { classes require special code to write the record and the invisible pointer }
        if is_class(def) then
          begin
            { Write the record class itself }
            tobjectdef(def).writing_class_record_dbginfo:=true;
            do_write_object(list,def);
            tobjectdef(def).writing_class_record_dbginfo:=false;
            { Write the invisible pointer class }
            oldtypesym:=def.typesym;
            def.typesym:=nil;
            do_write_object(list,def);
            def.typesym:=oldtypesym;
          end
        else
          do_write_object(list,def);
        { VMT symbol }
        if (oo_has_vmt in tobjectdef(def).objectoptions) and
           assigned(def.owner) and
           assigned(def.owner.name) then
          list.concat(Tai_stab.create(stab_stabs,strpnew('"vmt_'+GetSymTableName(def.owner)+tobjectdef(def).objname^+':S'+
                 def_stab_number(vmttype)+'",'+tostr(N_STSYM)+',0,0,'+tobjectdef(def).vmt_mangledname)));
      end;


    procedure TDebugInfoStabs.appenddef_variant(list:TAsmList;def:tvariantdef);
      var
        ss : ansistring;
      begin
        ss:=def_stabstr_evaluate(def,'${numberstring};',[]);
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.appenddef_pointer(list:TAsmList;def:tpointerdef);
      var
        ss : ansistring;
      begin
        ss:='*'+def_stab_number(tpointerdef(def).pointeddef);
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.appenddef_set(list:TAsmList;def:tsetdef);
      var
        ss : ansistring;
      begin
        ss:=def_stabstr_evaluate(def,'@s$1;S$2',[tostr(def.size*8),def_stab_number(tsetdef(def).elementdef)]);
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.appenddef_formal(list:TAsmList;def:tformaldef);
      var
        ss : ansistring;
      begin
        ss:=def_stabstr_evaluate(def,'${numberstring};',[]);
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.appenddef_array(list:TAsmList;def:tarraydef);
      var
        tempstr,
        ss : ansistring;
      begin
        if not is_packed_array(def) then
          ss:=def_stabstr_evaluate(def,'ar$1;$2;$3;$4',[def_stab_number(tarraydef(def).rangedef),
                   tostr(tarraydef(def).lowrange),tostr(tarraydef(def).highrange),def_stab_number(tarraydef(def).elementdef)])
        else
          begin
            // the @P seems to be ignored by gdb
            tempstr:=def_stabstr_evaluate(tarraydef(def).rangedef,'r${numberstring};$1;$2;',
              [tostr(tarraydef(def).lowrange),tostr(tarraydef(def).highrange)]);
            // will only show highrange-lowrange+1 bits in gdb
            ss:=def_stabstr_evaluate(def,'@s$1;@S;S$2',
              [tostr(TConstExprInt(tarraydef(def).elepackedbitsize) * tarraydef(def).elecount),tempstr]);
          end;
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.appenddef_procvar(list:TAsmList;def:tprocvardef);
      var
        ss : ansistring;
      begin
        ss:='*f'+def_stab_number(tprocvardef(def).returndef);
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.appenddef_undefined(list:TAsmList;def:tundefineddef);
      var
        ss : ansistring;
      begin
        ss:=def_stabstr_evaluate(def,'${numberstring};',[]);
        write_def_stabstr(list,def,ss);
      end;


    procedure TDebugInfoStabs.beforeappenddef(list:TAsmList;def:tdef);
      var
        anc : tobjectdef;
        i : longint;
      begin
        { write dependencies first }
        case def.typ of
          stringdef :
            begin
              if tstringdef(def).stringtype in [st_widestring,st_unicodestring] then
                appenddef(list,cwidechartype)
              else
                begin
                  appenddef(list,cchartype);
                  appenddef(list,u8inttype);
                end;
            end;
          floatdef :
            appenddef(list,s32inttype);
          filedef :
            begin
              appenddef(list,s32inttype);
{$ifdef cpu64bitaddr}
              appenddef(list,s64inttype);
{$endif cpu64bitaddr}
              appenddef(list,u8inttype);
              appenddef(list,cchartype);
            end;
          classrefdef :
            appenddef(list,pvmttype);
          pointerdef :
            appenddef(list,tpointerdef(def).pointeddef);
          setdef :
            appenddef(list,tsetdef(def).elementdef);
          procvardef :
            begin
              appenddef(list,tprocvardef(def).returndef);
              if assigned(tprocvardef(def).parast) then
                write_symtable_defs(list,tprocvardef(def).parast);
            end;
          procdef :
            begin
              appenddef(list,tprocdef(def).returndef);
              if assigned(tprocdef(def).parast) then
                write_symtable_defs(list,tprocdef(def).parast);
              if assigned(tprocdef(def).localst) and
                 (tprocdef(def).localst.symtabletype=localsymtable) then
                write_symtable_defs(list,tprocdef(def).localst);
            end;
          arraydef :
            begin
              appenddef(list,tarraydef(def).rangedef);
              appenddef(list,tarraydef(def).elementdef);
            end;
          recorddef :
            trecorddef(def).symtable.symList.ForEachCall(@field_write_defs,list);
          enumdef :
            if assigned(tenumdef(def).basedef) then
              appenddef(list,tenumdef(def).basedef);
          objectdef :
            begin
              { make sure we don't write child classdefs before their parent }
              { classdefs, because this crashes gdb                          }
              anc:=tobjectdef(def);
              while assigned(anc.childof) do
                begin
                  anc:=anc.childof;
                  if (anc.dbg_state=dbg_state_writing) then
                    { happens in case a field of a parent is of the (forward }
                    { defined) child type                                    }
                    begin
                      { We don't explicitly requeue it, but the fact that  }
                      { a child type was used in a parent before the child }
                      { type was fully defined means that it was forward   }
                      { declared, and will still be encountered later (it  }
                      { cannot have been declared in another unit, because }
                      { then this and that other unit would depend on      }
                      { eachother's interface)                             }
                      { Setting the state to queued however allows us to   }
                      { get the def number already without an IE           }
                      def.dbg_state:=dbg_state_queued;
                      exit;
                    end;
                end;
              appenddef(list,vmtarraytype);
              if assigned(tobjectdef(def).ImplementedInterfaces) then
                for i:=0 to tobjectdef(def).ImplementedInterfaces.Count-1 do
                  appenddef(list,TImplementedInterface(tobjectdef(def).ImplementedInterfaces[i]).IntfDef);
              { first the parents }
              anc:=tobjectdef(def);
              while assigned(anc.childof) do
                begin
                  anc:=anc.childof;
                  appenddef(list,anc);
                  if assigned(anc.ImplementedInterfaces) then
                    for i:=0 to anc.ImplementedInterfaces.Count-1 do
                      appenddef(list,TImplementedInterface(anc.ImplementedInterfaces[i]).IntfDef);
                end;
              tobjectdef(def).symtable.symList.ForEachCall(@field_write_defs,list);
            end;
        end;
      end;


    procedure TDebugInfoStabs.appendprocdef(list:TAsmList;def:tprocdef);
      var
        templist : TAsmList;
        stabsendlabel : tasmlabel;
        p  : pchar;
        RType : Char;
        Obj,Info : String;
        hs : string;
        ss : ansistring;
      begin
        if not assigned(def.procstarttai) then
          exit;

        { mark as used so the local type defs also be written }
        def.dbg_state:=dbg_state_used;

        templist:=TAsmList.create;

        { end of procedure }
        current_asmdata.getlabel(stabsendlabel,alt_dbgtype);

        if assigned(def.funcretsym) and
           (tabstractnormalvarsym(def.funcretsym).refs>0) then
          begin
            if tabstractnormalvarsym(def.funcretsym).localloc.loc=LOC_REFERENCE then
              begin
{$warning Need to add gdb support for ret in param register calling}
                if paramanager.ret_in_param(def.returndef,def.proccalloption) then
                  hs:='X*'
                else
                  hs:='X';
                templist.concat(Tai_stab.create(stab_stabs,strpnew(
                   '"'+GetSymName(def.procsym)+':'+hs+def_stab_number(def.returndef)+'",'+
                   tostr(N_tsym)+',0,0,'+tostr(tabstractnormalvarsym(def.funcretsym).localloc.reference.offset))));
                if (m_result in current_settings.modeswitches) then
                  templist.concat(Tai_stab.create(stab_stabs,strpnew(
                     '"RESULT:'+hs+def_stab_number(def.returndef)+'",'+
                     tostr(N_tsym)+',0,0,'+tostr(tabstractnormalvarsym(def.funcretsym).localloc.reference.offset))));
              end;
          end;
        // LBRAC
        ss:=tostr(N_LBRAC)+',0,0,';
        if target_info.cpu=cpu_powerpc64 then
          ss:=ss+'.';
        ss:=ss+def.mangledname;
        if (tf_use_function_relative_addresses in target_info.flags) then
          begin
            ss:=ss+'-';
            if target_info.cpu=cpu_powerpc64 then
              ss:=ss+'.';
            ss:=ss+def.mangledname;
          end;
        getmem(p,length(ss)+1);
        move(pchar(ss)^,p^,length(ss)+1);
        templist.concat(Tai_stab.Create(stab_stabn,p));
        // RBRAC
        ss:=tostr(N_RBRAC)+',0,0,'+stabsendlabel.name;
        if (tf_use_function_relative_addresses in target_info.flags) then
          begin
            ss:=ss+'-';
            if target_info.cpu=cpu_powerpc64 then
              ss:=ss+'.';
            ss:=ss+def.mangledname;
          end;
        getmem(p,length(ss)+1);
        move(pchar(ss)^,p^,length(ss)+1);
        templist.concat(Tai_stab.Create(stab_stabn,p));

        { the stabsendlabel must come after all other stabs for this }
        { function                                                   }
        templist.concat(tai_label.create(stabsendlabel));

        { Add a "size" stab as described in the last paragraph of 2.5 at  }
        { http://sourceware.org/gdb/current/onlinedocs/stabs_2.html#SEC12 }
        { This works at least on Darwin (and is needed on Darwin to get   }
        { correct smartlinking of stabs), but I don't know which binutils }
        { version is required on other platforms                          }
        { This stab must come after all other stabs for the procedure,    }
        { including the LBRAC/RBRAC ones                                  }
        if (target_info.system in systems_darwin) then
          templist.concat(Tai_stab.create(stab_stabs,
            strpnew('"",'+tostr(N_FUNCTION)+',0,0,'+stabsendlabel.name+'-'+def.mangledname)));

        current_asmdata.asmlists[al_procedures].insertlistafter(def.procendtai,templist);

        { "The stab representing a procedure is located immediately
          following the code of the procedure. This stab is in turn
          directly followed by a group of other stabs describing
          elements of the procedure. These other stabs describe the
          procedure's parameters, its block local variables, and its
          block structure." (stab docs)                               }
        { this is however incorrect in case "include source" statements }
        { appear in the block, in that case the procedure stab must     }
        { appear before this include stabs (and we generate such an     }
        { stabs for all functions) (JM)                                 }

        { FUNC stabs }
        obj := GetSymName(def.procsym);
        info := '';
        if (po_global in def.procoptions) then
          RType := 'F'
        else
          RType := 'f';
        if assigned(def.owner) then
          begin
            if (def.owner.symtabletype = objecTSymtable) then
              obj := GetSymTableName(def.owner)+'__'+GetSymName(def.procsym);
            if not(cs_gdb_valgrind in current_settings.globalswitches) and
               (def.owner.symtabletype=localsymtable) and
               assigned(def.owner.defowner) and
               assigned(tprocdef(def.owner.defowner).procsym) then
              info := ','+GetSymName(def.procsym)+','+GetSymName(tprocdef(def.owner.defowner).procsym);
          end;
        ss:='"'+ansistring(obj)+':'+RType+def_stab_number(def.returndef)+info+'",'+tostr(n_function)+',0,'+tostr(def.fileinfo.line)+','+ansistring(def.mangledname);
        getmem(p,length(ss)+1);
        move(pchar(ss)^,p^,length(ss)+1);
        templist.concat(Tai_stab.Create(stab_stabs,p));

        current_asmdata.asmlists[al_procedures].insertlistbefore(def.procstarttai,templist);

        { para types }
        if assigned(def.parast) then
          write_symtable_syms(templist,def.parast);
        { local type defs and vars should not be written
          inside the main proc stab }
        if assigned(def.localst) and
           (def.localst.symtabletype=localsymtable) then
          write_symtable_syms(templist,def.localst);

        current_asmdata.asmlists[al_procedures].insertlistbefore(def.procstarttai,templist);

        templist.free;
      end;


{****************************************************************************
                               TSym support
****************************************************************************}

    function TDebugInfoStabs.sym_var_value(const s:string;arg:pointer):string;
      var
        sym : tsym absolute arg;
      begin
        result:='';
        if s='name' then
          result:=GetSymName(sym)
        else if s='mangledname' then
          result:=sym.mangledname
        else if s='ownername' then
          result:=GetSymTableName(sym.owner)
        else if s='line' then
          result:=tostr(sym.fileinfo.line)
        else if s='N_LSYM' then
          result:=tostr(N_LSYM)
        else if s='N_LCSYM' then
          result:=tostr(N_LCSYM)
        else if s='N_RSYM' then
          result:=tostr(N_RSYM)
        else if s='N_TSYM' then
          result:=tostr(N_TSYM)
        else if s='N_STSYM' then
          result:=tostr(N_STSYM)
        else if s='N_FUNCTION' then
          result:=tostr(N_FUNCTION)
        else
          internalerror(200401152);
      end;


    function TDebugInfoStabs.sym_stabstr_evaluate(sym:tsym;const s:string;const vars:array of string):ansistring;
      begin
        result:=string_evaluate(s,@sym_var_value,sym,vars);
      end;


    procedure TDebugInfoStabs.write_sym_stabstr(list:TAsmList;sym:tsym;const ss:ansistring);
      var
        p : pchar;
      begin
        if ss='' then
          exit;
        { add to list }
        getmem(p,length(ss)+1);
        move(pchar(ss)^,p^,length(ss)+1);
        list.concat(Tai_stab.create(stab_stabs,p));
      end;


    procedure TDebugInfoStabs.appendsym_fieldvar(list:TAsmList;sym:tfieldvarsym);
      var
        ss : ansistring;
      begin
        ss:='';
        if (sym.owner.symtabletype=objecTSymtable) and
           (sp_static in sym.symoptions) then
          ss:=sym_stabstr_evaluate(sym,'"${ownername}__${name}:S$1",${N_LCSYM},0,${line},${mangledname}',
              [def_stab_number(sym.vardef)]);
        write_sym_stabstr(list,sym,ss);
      end;


    procedure TDebugInfoStabs.appendsym_staticvar(list:TAsmList;sym:tstaticvarsym);
      var
        ss : ansistring;
        st : string;
        threadvaroffset : string;
        regidx : Tregisterindex;
        nsym : string[7];
      begin
        { external symbols can't be resolved at link time, so we
          can't generate stabs for them }
        if vo_is_external in sym.varoptions then
          exit;
        ss:='';
        st:=def_stab_number(sym.vardef);
        case sym.localloc.loc of
          LOC_REGISTER,
          LOC_CREGISTER,
          LOC_MMREGISTER,
          LOC_CMMREGISTER,
          LOC_FPUREGISTER,
          LOC_CFPUREGISTER :
            begin
              regidx:=findreg_by_number(sym.localloc.register);
              { "eax", "ecx", "edx", "ebx", "esp", "ebp", "esi", "edi", "eip", "ps", "cs", "ss", "ds", "es", "fs", "gs", }
              { this is the register order for GDB}
              if regidx<>0 then
                ss:=sym_stabstr_evaluate(sym,'"${name}:r$1",${N_RSYM},0,${line},$2',[st,tostr(regstabs_table[regidx])]);
            end;
          else
            begin
              if (vo_is_thread_var in sym.varoptions) then
                threadvaroffset:='+'+tostr(sizeof(pint))
              else
                threadvaroffset:='';
              if (vo_is_typed_const in sym.varoptions) then
                nsym:='N_STSYM'
              else
                nsym:='N_LCSYM';
              { Here we used S instead of
                because with G GDB doesn't look at the address field
                but searches the same name or with a leading underscore
                but these names don't exist in pascal !}
              st:='S'+st;
              ss:=sym_stabstr_evaluate(sym,'"${name}:$1",${'+nsym+'},0,${line},${mangledname}$2',[st,threadvaroffset]);
            end;
        end;
        write_sym_stabstr(list,sym,ss);
      end;


    procedure TDebugInfoStabs.appendsym_localvar(list:TAsmList;sym:tlocalvarsym);
      var
        ss : ansistring;
        st : string;
        regidx : Tregisterindex;
      begin
        { There is no space allocated for not referenced locals }
        if (sym.owner.symtabletype=localsymtable) and (sym.refs=0) then
          exit;

        ss:='';
        st:=def_stab_number(sym.vardef);
        case sym.localloc.loc of
          LOC_REGISTER,
          LOC_CREGISTER,
          LOC_MMREGISTER,
          LOC_CMMREGISTER,
          LOC_FPUREGISTER,
          LOC_CFPUREGISTER :
            begin
              regidx:=findreg_by_number(sym.localloc.register);
              { "eax", "ecx", "edx", "ebx", "esp", "ebp", "esi", "edi", "eip", "ps", "cs", "ss", "ds", "es", "fs", "gs", }
              { this is the register order for GDB}
              if regidx<>0 then
                ss:=sym_stabstr_evaluate(sym,'"${name}:r$1",${N_RSYM},0,${line},$2',[st,tostr(regstabs_table[regidx])]);
            end;
          LOC_REFERENCE :
            { offset to ebp => will not work if the framepointer is esp
              so some optimizing will make things harder to debug }
            ss:=sym_stabstr_evaluate(sym,'"${name}:$1",${N_TSYM},0,${line},$2',[st,tostr(sym.localloc.reference.offset)])
          else
            internalerror(2003091814);
        end;
        write_sym_stabstr(list,sym,ss);
      end;


    procedure TDebugInfoStabs.appendsym_paravar(list:TAsmList;sym:tparavarsym);
      var
        ss : ansistring;
        st : string;
        regidx : Tregisterindex;
        c : char;
      begin
        ss:='';
        { set loc to LOC_REFERENCE to get somewhat usable debugging info for -Or }
        { while stabs aren't adapted for regvars yet                             }
        if (vo_is_self in sym.varoptions) then
          begin
            case sym.localloc.loc of
              LOC_REGISTER,
              LOC_CREGISTER:
                regidx:=findreg_by_number(sym.localloc.register);
              LOC_REFERENCE: ;
              else
                internalerror(2003091815);
            end;
            if (po_classmethod in tabstractprocdef(sym.owner.defowner).procoptions) or
               (po_staticmethod in tabstractprocdef(sym.owner.defowner).procoptions) then
              begin
                if (sym.localloc.loc=LOC_REFERENCE) then
                  ss:=sym_stabstr_evaluate(sym,'"pvmt:p$1",${N_TSYM},0,0,$2',
                    [def_stab_number(pvmttype),tostr(sym.localloc.reference.offset)])
                else
                  begin
                    regidx:=findreg_by_number(sym.localloc.register);
                    ss:=sym_stabstr_evaluate(sym,'"pvmt:r$1",${N_RSYM},0,0,$2',
                      [def_stab_number(pvmttype),tostr(regstabs_table[regidx])]);
                  end
                end
            else
              begin
                if not(is_class(tprocdef(sym.owner.defowner)._class)) then
                  c:='v'
                else
                  c:='p';
                if (sym.localloc.loc=LOC_REFERENCE) then
                  ss:=sym_stabstr_evaluate(sym,'"$$t:$1",${N_TSYM},0,0,$2',
                        [c+def_stab_number(tprocdef(sym.owner.defowner)._class),tostr(sym.localloc.reference.offset)])
                else
                  begin
                    regidx:=findreg_by_number(sym.localloc.register);
                    ss:=sym_stabstr_evaluate(sym,'"$$t:r$1",${N_RSYM},0,0,$2',
                        [c+def_stab_number(tprocdef(sym.owner.defowner)._class),tostr(regstabs_table[regidx])]);
                  end
              end;
          end
        else
          begin
            st:=def_stab_number(sym.vardef);

            if paramanager.push_addr_param(sym.varspez,sym.vardef,tprocdef(sym.owner.defowner).proccalloption) and
               not(vo_has_local_copy in sym.varoptions) and
               not is_open_string(sym.vardef) then
              c:='v' { should be 'i' but 'i' doesn't work }
            else
              c:='p';
            case sym.localloc.loc of
              LOC_REGISTER,
              LOC_CREGISTER,
              LOC_MMREGISTER,
              LOC_CMMREGISTER,
              LOC_FPUREGISTER,
              LOC_CFPUREGISTER :
                begin
                  if c='p' then
                    c:='R'
                  else
                    c:='a';
                  st:=c+st;
                  regidx:=findreg_by_number(sym.localloc.register);
                  { "eax", "ecx", "edx", "ebx", "esp", "ebp", "esi", "edi", "eip", "ps", "cs", "ss", "ds", "es", "fs", "gs", }
                  { this is the register order for GDB}
                  if regidx<>0 then
                    ss:=sym_stabstr_evaluate(sym,'"${name}:$1",${N_RSYM},0,${line},$2',[st,tostr(longint(regstabs_table[regidx]))]);
                end;
              LOC_REFERENCE :
                begin
                  st:=c+st;
                  { offset to ebp => will not work if the framepointer is esp
                    so some optimizing will make things harder to debug }
                  ss:=sym_stabstr_evaluate(sym,'"${name}:$1",${N_TSYM},0,${line},$2',[st,tostr(sym.localloc.reference.offset)])
                end;
              else
                internalerror(2003091814);
            end;
          end;
        write_sym_stabstr(list,sym,ss);
      end;


    procedure TDebugInfoStabs.appendsym_const(list:TAsmList;sym:tconstsym);
      var
        st : string;
        ss : ansistring;
      begin
        ss:='';
        { Don't write info for default parameter values, the N_Func breaks
          the N_Func for the function itself.
          Valgrind does not support constants }
        if (sym.owner.symtabletype=parasymtable) or
           (cs_gdb_valgrind in current_settings.globalswitches) then
          exit;
        case sym.consttyp of
          conststring:
            begin
              if sym.value.len<200 then
                st:='s'''+backspace_quote(octal_quote(strpas(pchar(sym.value.valueptr)),[#0..#9,#11,#12,#14..#31,'''']),['"','\',#10,#13])+''''
              else
                st:='<constant string too long>';
            end;
          constord:
            st:='i'+tostr(sym.value.valueord);
          constpointer:
            st:='i'+tostr(sym.value.valueordptr);
          constreal:
            begin
              system.str(pbestreal(sym.value.valueptr)^,st);
              st := 'r'+st;
            end;
          else
            begin
              { if we don't know just put zero !! }
              st:='i0';
            end;
        end;
        ss:=sym_stabstr_evaluate(sym,'"${name}:c=$1;",${N_FUNCTION},0,${line},0',[st]);
        write_sym_stabstr(list,sym,ss);
      end;


    procedure TDebugInfoStabs.appendsym_type(list:TAsmList;sym:ttypesym);
      var
        ss : ansistring;
        stabchar : string[2];
      begin
        ss:='';
        if not assigned(sym.typedef) then
          internalerror(200509262);
        if sym.typedef.typ in tagtypes then
          stabchar:='Tt'
        else
          stabchar:='t';
        ss:=sym_stabstr_evaluate(sym,'"${name}:$1$2",${N_LSYM},0,${line},0',[stabchar,def_stab_number(sym.typedef)]);
        write_sym_stabstr(list,sym,ss);
      end;


    procedure TDebugInfoStabs.appendsym_label(list:TAsmList;sym:tlabelsym);
      var
        ss : ansistring;
      begin
        ss:=sym_stabstr_evaluate(sym,'"${name}",${N_LSYM},0,${line},0',[]);
        write_sym_stabstr(list,sym,ss);
      end;


{****************************************************************************
                             Proc/Module support
****************************************************************************}

    procedure tdebuginfostabs.inserttypeinfo;
      var
        stabsvarlist,
        stabstypelist : TAsmList;
        storefilepos  : tfileposinfo;
        i  : longint;
      begin
        storefilepos:=current_filepos;
        current_filepos:=current_module.mainfilepos;

        global_stab_number:=0;
        defnumberlist:=TFPObjectlist.create(false);
        stabsvarlist:=TAsmList.create;
        stabstypelist:=TAsmList.create;

        { include symbol that will be referenced from the main to be sure to
          include this debuginfo .o file }
        current_module.flags:=current_module.flags or uf_has_debuginfo;
        if not(target_info.system in systems_darwin) then
          begin
            new_section(current_asmdata.asmlists[al_stabs],sec_data,GetSymTableName(current_module.localsymtable),0);
            current_asmdata.asmlists[al_stabs].concat(tai_symbol.Createname_global(make_mangledname('DEBUGINFO',current_module.localsymtable,''),AT_DATA,0));
          end
        else
          new_section(current_asmdata.asmlists[al_stabs],sec_code,GetSymTableName(current_module.localsymtable),0);

        { write all global/local variables. This will flag all required tdefs  }
        if assigned(current_module.globalsymtable) then
          write_symtable_syms(stabsvarlist,current_module.globalsymtable);
        if assigned(current_module.localsymtable) then
          write_symtable_syms(stabsvarlist,current_module.localsymtable);

        { write all procedures and methods. This will flag all required tdefs }
        if assigned(current_module.globalsymtable) then
          write_symtable_procdefs(stabsvarlist,current_module.globalsymtable);
        if assigned(current_module.localsymtable) then
          write_symtable_procdefs(stabsvarlist,current_module.localsymtable);

        { reset unit type info flag }
        reset_unit_type_info;

        { write used types from the used units }
        write_used_unit_type_info(stabstypelist,current_module);
        { last write the types from this unit }
        if assigned(current_module.globalsymtable) then
          write_symtable_defs(stabstypelist,current_module.globalsymtable);
        if assigned(current_module.localsymtable) then
          write_symtable_defs(stabstypelist,current_module.localsymtable);

        current_asmdata.asmlists[al_stabs].concatlist(stabstypelist);
        current_asmdata.asmlists[al_stabs].concatlist(stabsvarlist);

        { reset stab numbers }
        for i:=0 to defnumberlist.count-1 do
          begin
            if assigned(defnumberlist[i]) then
              begin
                tdef(defnumberlist[i]).stab_number:=0;
                tdef(defnumberlist[i]).dbg_state:=dbg_state_unused;
              end;
          end;

        defnumberlist.free;
        defnumberlist:=nil;

        stabsvarlist.free;
        stabstypelist.free;
        current_filepos:=storefilepos;
      end;


    procedure tdebuginfostabs.insertlineinfo(list:TAsmList);
      var
        currfileinfo,
        lastfileinfo : tfileposinfo;
        currfuncname : pshortstring;
        currsectype  : TAsmSectiontype;
        hlabel       : tasmlabel;
        hp : tai;
        infile : tinputfile;
      begin
        FillChar(lastfileinfo,sizeof(lastfileinfo),0);
        currfuncname:=nil;
        currsectype:=sec_code;
        hp:=Tai(list.first);
        while assigned(hp) do
          begin
            case hp.typ of
              ait_section :
                currsectype:=tai_section(hp).sectype;
              ait_function_name :
                currfuncname:=tai_function_name(hp).funcname;
              ait_force_line :
                lastfileinfo.line:=-1;
            end;

            if (currsectype=sec_code) and
               (hp.typ=ait_instruction) then
              begin
                currfileinfo:=tailineinfo(hp).fileinfo;
                { file changed ? (must be before line info) }
                if (currfileinfo.fileindex<>0) and
                   ((lastfileinfo.fileindex<>currfileinfo.fileindex) or
                    (lastfileinfo.moduleindex<>currfileinfo.moduleindex)) then
                  begin
                    infile:=get_module(currfileinfo.moduleindex).sourcefiles.get_file(currfileinfo.fileindex);
                    if assigned(infile) then
                      begin
                        current_asmdata.getlabel(hlabel,alt_dbgfile);
                        { emit stabs }
                        if (infile.path^<>'') then
                          list.insertbefore(Tai_stab.Create_str(stab_stabs,'"'+BsToSlash(FixPath(infile.path^,false))+'",'+tostr(n_includefile)+
                                            ',0,0,'+hlabel.name),hp);
                        list.insertbefore(Tai_stab.Create_str(stab_stabs,'"'+FixFileName(infile.name^)+'",'+tostr(n_includefile)+
                                          ',0,0,'+hlabel.name),hp);
                        list.insertbefore(tai_label.create(hlabel),hp);
                        { force new line info }
                        lastfileinfo.line:=-1;
                      end;
                  end;

                { line changed ? }
                if (currfileinfo.line>lastfileinfo.line) and (currfileinfo.line<>0) then
                  begin
                     if assigned(currfuncname) and
                        (tf_use_function_relative_addresses in target_info.flags) then
                      begin
                        current_asmdata.getlabel(hlabel,alt_dbgline);
                        list.insertbefore(Tai_stab.Create_str(stab_stabn,tostr(n_textline)+',0,'+tostr(currfileinfo.line)+','+
                                          hlabel.name+' - '+{$IFDEF POWERPC64}'.'+{$ENDIF POWERPC64}currfuncname^),hp);
                        list.insertbefore(tai_label.create(hlabel),hp);
                      end
                     else
                      list.insertbefore(Tai_stab.Create_str(stab_stabd,tostr(n_textline)+',0,'+tostr(currfileinfo.line)),hp);
                  end;
                lastfileinfo:=currfileinfo;
              end;

            hp:=tai(hp.next);
          end;
      end;


    procedure tdebuginfostabs.insertmoduleinfo;
      var
        hlabel : tasmlabel;
        infile : tinputfile;
      begin
        { emit main source n_sourcefile for start of module }
        current_asmdata.getlabel(hlabel,alt_dbgfile);
        infile:=current_module.sourcefiles.get_file(1);
        new_section(current_asmdata.asmlists[al_start],sec_code,make_mangledname('DEBUGSTART',current_module.localsymtable,''),0,secorder_begin);
        if not(target_info.system in systems_darwin) then
          current_asmdata.asmlists[al_start].concat(tai_symbol.Createname_global(make_mangledname('DEBUGSTART',current_module.localsymtable,''),AT_DATA,0));
        if (infile.path^<>'') then
          current_asmdata.asmlists[al_start].concat(Tai_stab.Create_str(stab_stabs,'"'+BsToSlash(FixPath(infile.path^,false))+'",'+tostr(n_sourcefile)+
                      ',0,0,'+hlabel.name));
        current_asmdata.asmlists[al_start].concat(Tai_stab.Create_str(stab_stabs,'"'+FixFileName(infile.name^)+'",'+tostr(n_sourcefile)+
                    ',0,0,'+hlabel.name));
        current_asmdata.asmlists[al_start].concat(tai_label.create(hlabel));
        { for darwin, you need a "module marker" too to work around      }
        { either some assembler or gdb bug (radar 4386531 according to a }
        { comment in dbxout.c of Apple's gcc)                            }
        if (target_info.system in systems_darwin) then
          current_asmdata.asmlists[al_end].concat(Tai_stab.Create_str(stab_stabs,'"",'+tostr(N_OSO)+',0,0,0'));
        { emit empty n_sourcefile for end of module }
        current_asmdata.getlabel(hlabel,alt_dbgfile);
        new_section(current_asmdata.asmlists[al_end],sec_code,make_mangledname('DEBUGEND',current_module.localsymtable,''),0,secorder_end);
        if not(target_info.system in systems_darwin) then
          current_asmdata.asmlists[al_end].concat(tai_symbol.Createname_global(make_mangledname('DEBUGEND',current_module.localsymtable,''),AT_DATA,0));
        current_asmdata.asmlists[al_end].concat(Tai_stab.Create_str(stab_stabs,'"",'+tostr(n_sourcefile)+',0,0,'+hlabel.name));
        current_asmdata.asmlists[al_end].concat(tai_label.create(hlabel));
      end;


    procedure tdebuginfostabs.referencesections(list:TAsmList);
      var
        hp : tmodule;
        dbgtable : tai_symbol;
      begin
        { Reference all DEBUGINFO sections from the main .fpc section }
        if (target_info.system in ([system_powerpc_macos]+systems_darwin)) then
          exit;
        list.concat(Tai_section.create(sec_fpc,'links',0));
        { make sure the debuginfo doesn't get stripped out }
        if (target_info.system in systems_darwin) then
          begin
            dbgtable:=tai_symbol.createname('DEBUGINFOTABLE',AT_DATA,0);
            list.concat(tai_directive.create(asd_no_dead_strip,dbgtable.sym.name));
            list.concat(dbgtable);
          end;
        { include reference to all debuginfo sections of used units }
        hp:=tmodule(loaded_units.first);
        while assigned(hp) do
          begin
            If (hp.flags and uf_has_debuginfo)=uf_has_debuginfo then
              begin
                list.concat(Tai_const.Createname(make_mangledname('DEBUGINFO',hp.localsymtable,''),0));
                list.concat(Tai_const.Createname(make_mangledname('DEBUGSTART',hp.localsymtable,''),0));
                list.concat(Tai_const.Createname(make_mangledname('DEBUGEND',hp.localsymtable,''),0));
              end;
            hp:=tmodule(hp.next);
          end;
      end;


    const
      dbg_stabs_info : tdbginfo =
         (
           id     : dbg_stabs;
           idtxt  : 'STABS';
         );

initialization
  RegisterDebugInfo(dbg_stabs_info,TDebugInfoStabs);
end.