freepascal.compiler/compiler/systems.pas

{
    Copyright (c) 1998-2008 by Florian Klaempfl

    This unit contains information about the target systems supported
    (these are not processor specific)

    This program is free software; you can redistribute it and/or modify
    iu 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 systems;

{$i fpcdefs.inc}

interface


   type
       tendian = (endian_little,endian_big);

     (*
       IMPORTANT NOTE:
       The value of this enumeration is stored in PPU files.
       Therefore adding new CPU targets should not change the
       values of the pre-existing targets. (CEC)
       FURTHERMORE : Make sure that this branch values, are
       consistant with the main branch version always.
     *)
       tsystemcpu=
       (
             cpu_no,                       { 0 }
             cpu_i386,                     { 1 }
             cpu_m68k,                     { 2 }
             cpu_alpha,                    { 3 }
             cpu_powerpc,                  { 4 }
             cpu_sparc,                    { 5 }
             cpu_vm,                       { 6 }
             cpu_iA64,                     { 7 }
             cpu_x86_64,                   { 8 }
             cpu_mips,                     { 9 }
             cpu_arm,                      { 10 }
             cpu_powerpc64,                { 11 }
             cpu_avr,                      { 12 }
             cpu_mipsel                    { 13 }
       );

       tasmmode= (asmmode_none
            { standard assembler (cpu dependant) with full parsing }
            ,asmmode_standard
            ,asmmode_i386_att
            ,asmmode_i386_intel
            ,asmmode_ppc_gas
            ,asmmode_ppc_motorola
            ,asmmode_arm_gas
            ,asmmode_sparc_gas
            ,asmmode_x86_64_gas
            ,asmmode_m68k_mot
            ,asmmode_x86_64_intel
            ,asmmode_x86_64_att
            ,asmmode_avr_gas
       );

     (* IMPORTANT NOTE:
       the integer value of this enum is stored in PPU
       files to recognize the target, so if you add new targets
       allways add them at end PM
       FURTHERMORE : Make sure that this branch values are
       consistant with the main branch version always. (CEC)
       *)
     type
       tsystem =
       (
             system_none,               { 0 }
             obsolete_system_i386_GO32V1,{ 1 }
             system_i386_GO32V2,        { 2 }
             system_i386_linux,         { 3 }
             system_i386_OS2,           { 4 }
             system_i386_Win32,         { 5 }
             system_i386_freebsd,       { 6 }
             system_m68k_Amiga,         { 7 }
             system_m68k_Atari,         { 8 }
             system_m68k_Mac,           { 9 }
             system_m68k_linux,         { 10 }
             system_m68k_PalmOS,        { 11 }
             system_alpha_linux,        { 12 }
             system_powerpc_linux,      { 13 }
             system_powerpc_macos,      { 14 }
             system_i386_solaris,       { 15 }
             system_i386_beos,          { 16 }
             system_i386_netbsd,        { 17 }
             system_m68k_netbsd,        { 18 }
             system_i386_Netware,       { 19 }
             system_i386_qnx,           { 20 }
             system_i386_wdosx,         { 21 }
             system_sparc_solaris,      { 22 }
             system_sparc_linux,        { 23 }
             system_i386_openbsd,       { 24 }
             system_m68k_openbsd,       { 25 }
             system_x86_64_linux,       { 26 }
             system_powerpc_darwin,     { 27 }
             system_i386_EMX,           { 28 }
             system_powerpc_netbsd,     { 29 }
             system_powerpc_openbsd,    { 30 }
             system_arm_linux,          { 31 }
             system_i386_watcom,        { 32 }
             system_powerpc_MorphOS,    { 33 }
             system_x86_64_freebsd,     { 34 }
             system_i386_netwlibc,      { 35 }
             system_powerpc_Amiga,      { 36 }
             system_x86_64_win64,       { 37 }
             system_arm_wince,          { 38 }
             system_ia64_win64,         { 39 }
             system_i386_wince,         { 40 }
             system_x86_6432_linux,     { 41 }
             system_arm_gba,            { 42 }
             system_powerpc64_linux,    { 43 }
             system_i386_darwin,        { 44 }
             system_arm_palmos,         { 45 }
             system_powerpc64_darwin,   { 46 }
             system_arm_nds,            { 47 }
             system_i386_embedded,      { 48 }
             system_m68k_embedded,      { 49 }
             system_alpha_embedded,     { 50 }
             system_powerpc_embedded,   { 51 }
             system_sparc_embedded,     { 52 }
             system_vm_embedded,        { 53 }
             system_iA64_embedded,      { 54 }
             system_x86_64_embedded,    { 55 }
             system_mips_embedded,      { 56 }
             system_arm_embedded,       { 57 }
             system_powerpc64_embedded, { 58 }
             system_i386_symbian,       { 59 }
             system_arm_symbian,        { 60 }
             system_x86_64_darwin,      { 61 }
             system_avr_embedded,       { 62 }
             system_i386_haiku,         { 63 }
             system_arm_darwin,         { 64 }
             system_x86_64_solaris,     { 65 }
             system_mips_linux,         { 66 }
             system_mipsel_linux,       { 67 }
             system_i386_nativent,      { 68 }
             system_i386_iphonesim,     { 69 }
             system_powerpc_wii         { 70 }
       );

     type
       tasm = (as_none
             ,as_gas                   { standard gnu assembler }
             ,as_i386_as_aout
             ,as_i386_nasmcoff
             ,as_i386_nasmwin32
             ,as_i386_nasmwdosx
             ,as_i386_nasmelf
             ,as_i386_nasmobj
             ,as_i386_nasmbeos
             ,as_i386_tasm
             ,as_i386_masm
             ,as_i386_wasm
             ,as_i386_coff
             ,as_i386_pecoff
             ,as_i386_elf32
             ,as_i386_pecoffwdosx
             ,as_m68k_mit
             ,as_powerpc_mpw
             ,as_darwin
             ,as_i386_macho
             ,as_x86_64_masm
             ,as_x86_64_pecoff
             ,as_i386_pecoffwince
             ,as_arm_pecoffwince
             ,as_x86_64_elf64
             ,as_sparc_elf32
             ,as_ggas                  { gnu assembler called "gas" instead of "as" }
             ,as_i386_nasmhaiku
             ,as_powerpc_vasm
             ,as_i386_nlmcoff
       );

       tar = (ar_none
            ,ar_gnu_ar
            ,ar_mpw_ar
            ,ar_gnu_ar_scripted
            ,ar_gnu_gar
       );

       tres = (res_none
            ,res_gnu_windres,res_watcom_wrc_os2
            ,res_m68k_palmos,res_m68k_mpw
            ,res_powerpc_mpw,res_elf
            ,res_win64_gorc, res_macho, res_ext
       );

       tresinfoflags = (res_external_file,res_arch_in_file_name
            ,res_single_file);

       tdbg = (dbg_none
            ,dbg_stabs,dbg_dwarf2,dbg_dwarf3,dbg_dwarf4
       );

       tscripttype = (script_none
            ,script_dos,script_unix,script_amiga,
            script_mpw
       );

       tabi = (abi_default
            ,abi_powerpc_sysv,abi_powerpc_aix
            ,abi_eabi,abi_armeb
       );

{*****************************************************************************
                               Structures
*****************************************************************************}

     type
       { Abstract linker class which is implemented in link module }
       TAbstractLinker = class
       end;

       TAbstractLinkerClass = class of TAbstractLinker;


       { Abstract assembler class which is implemented in assemble module }
       TAbstractAssembler = class
       end;

       TAbstractAssemblerClass = class of TAbstractAssembler;


       TAbstractResourceFile = class
         constructor create(const fn : ansistring);virtual;abstract;
       end;
       TAbstractResourceFileClass = class of TAbstractResourceFile;


       palignmentinfo = ^talignmentinfo;
       { this is written to ppus during token recording for generics so it must be packed }
       talignmentinfo = packed record
         procalign,
         loopalign,
         jumpalign,
         constalignmin,
         constalignmax,
         varalignmin,
         varalignmax,
         localalignmin,
         localalignmax,
         recordalignmin,
         recordalignmax,
         maxCrecordalign : longint;
       end;

       tasmflags = (af_none,
         af_outputbinary,af_allowdirect,
         af_needar,af_smartlink_sections,
         af_labelprefix_only_inside_procedure,
         af_supports_dwarf,
         af_no_debug,
         af_stabs_use_function_absolute_addresses
       );

       pasminfo = ^tasminfo;
       tasminfo = record
          id          : tasm;
          idtxt       : string[12];
          asmbin      : string[8];
          asmcmd      : string[50];
          supported_targets : set of tsystem;
          flags        : set of tasmflags;
          labelprefix : string[3];
          comment     : string[3];
       end;

       parinfo = ^tarinfo;
       tarinfo = record
          id          : tar;
          arcmd       : string[50];
          arfinishcmd : string[10];
       end;

       presinfo = ^tresinfo;
       tresinfo = record
          id      : tres;
          { Compiler for resource (.rc or .res) to obj }
          resbin  : string[10];
          rescmd  : string[50];
          { Optional compiler for resource script (.rc) to binary resource (.res). }
          { If it is not provided resbin and rescmd will be used.                 }
          rcbin   : string[10];
          rccmd   : string[50];
          resourcefileclass : TAbstractResourceFileClass;
          resflags : set of tresinfoflags;
       end;

       pdbginfo = ^tdbginfo;
       tdbginfo = record
          id      : tdbg;
          idtxt   : string[12];
       end;

       tsystemflags = (tf_none,
            tf_under_development,
            tf_need_export,
            tf_needs_isconsole,
            tf_code_small,
            tf_static_reg_based,
            tf_needs_symbol_size,
            tf_smartlink_sections,
            tf_smartlink_library,
            tf_needs_dwarf_cfi,
            tf_use_8_3,
            tf_pic_uses_got,
            tf_library_needs_pic,
            tf_needs_symbol_type,
            tf_section_threadvars,
            tf_files_case_sensitive,
            tf_files_case_aware,
            tf_p_ext_support,
            tf_has_dllscanner,
            tf_use_function_relative_addresses,
            tf_winlikewidestring,
            tf_dwarf_relative_addresses,         // use offsets where the Dwarf spec requires this instead of absolute addresses (the latter is needed by Linux binutils)
            tf_dwarf_only_local_labels,          // only use local labels inside the Dwarf debug_info section (needed for e.g. Darwin)
            tf_requires_proper_alignment,
            tf_no_pic_supported,
            tf_pic_default,
            { the os does some kind of stack checking and it can be converted into a rte 202 }
            tf_no_generic_stackcheck,
            tf_has_winlike_resources,
            tf_safecall_clearstack,             // With this flag set, after safecall calls the caller cleans up the stack
            tf_safecall_exceptions              // Exceptions in safecall calls are not raised, but passed to the caller as an ordinal (hresult) in the function result.
                                                // The original result (if it exists) is passed as an extra parameter
       );

       psysteminfo = ^tsysteminfo;
       { using packed causes bus errors on processors which require alignment }
       tsysteminfo = record
          system       : tsystem;
          name         : string[34];
          shortname    : string[9];
          flags        : set of tsystemflags;
          cpu          : tsystemcpu;
          unit_env     : string[16];
          extradefines : string[40];
          exeext,
          defext,
          scriptext,
          smartext,
          unitext,
          unitlibext,
          asmext,
          objext,
          resext       : string[4];
          resobjext    : string[7];
          sharedlibext : string[10];
          staticlibext,
          staticlibprefix : string[4];
          sharedlibprefix : string[4];
          sharedClibext : string[10];
          staticClibext,
          staticClibprefix : string[4];
          sharedClibprefix : string[4];
          importlibprefix : string[10];
          importlibext : string[4];
          Cprefix      : string[2];
          newline      : string[2];
          dirsep       : char;
          assem        : tasm;
          assemextern  : tasm; { external assembler, used by -a }
          link         : tabstractlinkerclass;
          linkextern   : tabstractlinkerclass;  { external linker, used by -s }
          ar           : tar;
          res          : tres;
          dbg          : tdbg;
          script       : tscripttype;
          endian       : tendian;
          alignment    : talignmentinfo;
          {
            Offset from the argument pointer register to the first
            argument's address. On some machines it may depend on
            the data type of the function.
            (see also FIRST_PARM_OFFSET in GCC source)
          }
          first_parm_offset : longint;
          stacksize    : longint;
          abi          : tabi;
       end;

    const
       { alias for supported_target field in tasminfo }
       system_any = system_none;

       systems_wince = [system_arm_wince,system_i386_wince];
       systems_linux = [system_i386_linux,system_x86_64_linux,system_powerpc_linux,system_powerpc64_linux,
                       system_arm_linux,system_sparc_linux,system_alpha_linux,system_m68k_linux,
                       system_x86_6432_linux,system_mips_linux,system_mipsel_linux];

       { all real windows systems, no cripple ones like wince, wdosx et. al. }
       systems_windows = [system_i386_win32,system_x86_64_win64,system_ia64_win64];

       { all windows systems }
       systems_all_windows = [system_i386_win32,system_x86_64_win64,system_ia64_win64,
                             system_arm_wince,system_i386_wince];

       { all darwin systems }
       systems_darwin = [system_powerpc_darwin,system_i386_darwin,
                         system_powerpc64_darwin,system_x86_64_darwin,
                         system_arm_darwin,system_i386_iphonesim];

       {all solaris systems }
       systems_solaris = [system_sparc_solaris, system_i386_solaris,
			  system_x86_64_solaris];

       { all embedded systems }
       systems_embedded = [system_i386_embedded,system_m68k_embedded,
                           system_alpha_embedded,system_powerpc_embedded,
                           system_sparc_embedded,system_vm_embedded,
                           system_iA64_embedded,system_x86_64_embedded,
                           system_mips_embedded,system_arm_embedded,
                           system_powerpc64_embedded];

       { all symbian systems }
       systems_symbian = [system_i386_symbian,system_arm_symbian];

       { all classic Mac OS targets }
       systems_macos = [system_m68k_Mac,system_powerpc_Macos];

       { all OS/2 targets }
       systems_os2 = [system_i386_OS2,system_i386_emx];

       { all native nt systems }
       systems_nativent = [system_i386_nativent];

       { systems supporting Objective-C }
       systems_objc_supported = systems_darwin;

       { systems using the non-fragile Objective-C ABI }
       systems_objc_nfabi = [system_powerpc64_darwin,system_x86_64_darwin,system_arm_darwin,system_i386_iphonesim];

       { all systems supporting exports from programs or units }
       systems_unit_program_exports = [system_i386_win32,
                                         system_i386_wdosx,
                                         system_i386_Netware,
                                         system_i386_netwlibc,
                                         system_arm_wince,
                                         system_x86_64_win64,
                                         system_ia64_win64]+systems_linux;

       { all systems for which weak linking has been tested/is supported }
       systems_weak_linking = systems_darwin + systems_solaris;

       systems_internal_sysinit = [system_i386_linux,system_i386_win32];

       systems_interrupt_table = [{system_arm_embedded}];

       { all systems for which istack must be at a 16 byte boundary
         when calling a function }
       systems_need_16_byte_stack_alignment = [
      	system_i386_darwin,
      	system_i386_iphonesim,
        system_x86_64_darwin,
        system_x86_64_win64,
        system_x86_64_linux,
        system_x86_64_freebsd,
        system_x86_64_solaris];

       cpu2str : array[TSystemCpu] of string[10] =
            ('','i386','m68k','alpha','powerpc','sparc','vm','ia64','x86_64',
             'mips','arm', 'powerpc64', 'avr', 'mipsel');

       abi2str : array[tabi] of string[10] =
         ('DEFAULT','SYSV','AIX','EABI','ARMEB');

    var
       targetinfos   : array[tsystem] of psysteminfo;
       arinfos       : array[tar] of parinfo;
       resinfos      : array[tres] of presinfo;
       asminfos      : array[tasm] of pasminfo;
       dbginfos      : array[tdbg] of pdbginfo;

       source_info : tsysteminfo;
       target_cpu  : tsystemcpu;
       target_info : tsysteminfo;
       target_asm  : tasminfo;
       target_ar   : tarinfo;
       target_res  : tresinfo;
       target_dbg  : tdbginfo;
       target_cpu_string,
       target_os_string   : string[12]; { for rtl/<X>/,fcl/<X>/, etc. }
       target_full_string : string[24];

    function set_target(t:tsystem):boolean;
    function set_target_asm(t:tasm):boolean;
    function set_target_ar(t:tar):boolean;
    function set_target_res(t:tres):boolean;
    function set_target_dbg(t:tdbg):boolean;

    function find_system_by_string(const s : string) : tsystem;
    function find_asm_by_string(const s : string) : tasm;
    function find_dbg_by_string(const s : string) : tdbg;

    procedure set_source_info(const ti : tsysteminfo);

    function UpdateAlignment(var d:talignmentinfo;const s:talignmentinfo) : boolean;

    procedure RegisterTarget(const r:tsysteminfo);
    procedure RegisterRes(const r:tresinfo; rcf : TAbstractResourceFileClass);
    procedure RegisterAr(const r:tarinfo);
    { Register the external linker. This routine is called to setup the
      class to use for the linker. It returns the tsysteminfo structure
      updated with the correct linker class for external linking.
    }
    procedure RegisterExternalLinker(var system_info: tsysteminfo; c:TAbstractLinkerClass);
    { Register the internal linker. This routine is called to setup the
      class to use for the linker. It returns the tsysteminfo structure
      updated with the correct linker class for internal linking.

      If internal linking is not supported, this class can be set
      to nil.
    }
    procedure RegisterInternalLinker(var system_info : tsysteminfo; c:TAbstractLinkerClass);

    procedure InitSystems;

    {$ifdef FreeBSD}
        function GetOSRelDate:Longint;
    {$endif}

implementation

    uses
      cutils{$ifdef FreeBSD},SysCtl,BaseUnix{$endif};

{****************************************************************************
           OS runtime version detection utility routine
****************************************************************************}

{$ifdef FreeBSD}
function GetOSRelDate:Longint;

var
        mib  : array[0..1] of cint;
        rval : cint;
        len  : size_t;
        i    : longint;
        v    : longint;
        oerrno : cint;
        S    : AnsiString;

Begin
        s:='ab';
        SetLength(S,50);
        mib[0] := CTL_KERN;
        mib[1] := KERN_OSRELDATE;
        len    := 4;
        oerrno:= fpgeterrno;
        if (FPsysctl(pChar(@mib), 2, pchar(@v), @len, NIL, 0) = -1) Then
           Begin
                if (fpgeterrno = ESysENOMEM) Then
                        fpseterrno(oerrno);
                GetOSRelDate:=0;
           End
        else
         GetOSRelDate:=v;
End;
{$endif}


{****************************************************************************
                              Target setting
****************************************************************************}

function set_target(t:tsystem):boolean;
begin
  set_target:=false;
  if assigned(targetinfos[t]) then
   begin
     target_info:=targetinfos[t]^;
     set_target_asm(target_info.assem);
     set_target_ar(target_info.ar);
     set_target_res(target_info.res);
     set_target_dbg(target_info.dbg);
     target_cpu:=target_info.cpu;
     target_os_string:=lower(target_info.shortname);
     target_cpu_string:=cpu2str[target_cpu];
     target_full_string:=target_cpu_string+'-'+target_os_string;
     set_target:=true;
     exit;
   end;
end;


function set_target_asm(t:tasm):boolean;
begin
  set_target_asm:=false;
  if assigned(asminfos[t]) and
    ((target_info.system in asminfos[t]^.supported_targets) or
     (system_any in asminfos[t]^.supported_targets)) then
   begin
     target_asm:=asminfos[t]^;
     set_target_asm:=true;
     exit;
   end;
end;


function set_target_ar(t:tar):boolean;
begin
  result:=false;
  if assigned(arinfos[t]) then
   begin
     target_ar:=arinfos[t]^;
     result:=true;
     exit;
   end;
end;


function set_target_res(t:tres):boolean;
begin
  result:=false;
  if assigned(resinfos[t]) then
   begin
     target_res:=resinfos[t]^;
     result:=true;
     exit;
   end
  else
   FillByte(target_res,sizeof(target_res),0);
end;


function set_target_dbg(t:tdbg):boolean;
begin
  result:=false;
  if assigned(dbginfos[t]) then
   begin
     target_dbg:=dbginfos[t]^;
     result:=true;
     exit;
   end;
end;


function find_system_by_string(const s : string) : tsystem;
var
  hs : string;
  t  : tsystem;
begin
  result:=system_none;
  hs:=upper(s);
  for t:=low(tsystem) to high(tsystem) do
   if assigned(targetinfos[t]) and
      (upper(targetinfos[t]^.shortname)=hs) then
    begin
      result:=t;
      exit;
    end;
end;


function find_asm_by_string(const s : string) : tasm;
var
  hs : string;
  t  : tasm;
begin
  result:=as_none;
  hs:=upper(s);
  for t:=low(tasm) to high(tasm) do
   if assigned(asminfos[t]) and
      (asminfos[t]^.idtxt=hs) then
    begin
      result:=t;
      exit;
    end;
end;


function find_dbg_by_string(const s : string) : tdbg;
var
  hs : string;
  t  : tdbg;
begin
  result:=dbg_none;
  hs:=upper(s);
  for t:=low(tdbg) to high(tdbg) do
   if assigned(dbginfos[t]) and
      (dbginfos[t]^.idtxt=hs) then
    begin
      result:=t;
      exit;
    end;
end;


function UpdateAlignment(var d:talignmentinfo;const s:talignmentinfo) : boolean;
begin
  result:=true;
  with d do
   begin
     if (s.procalign in [1,2,4,8,16,32,64,128]) or (s.procalign=256) then
       procalign:=s.procalign
     else if s.procalign<>0 then
       result:=false;
     if (s.loopalign in [1,2,4,8,16,32,64,128]) or (s.loopalign=256) then
       loopalign:=s.loopalign
     else if s.loopalign<>0 then
       result:=false;
     if (s.jumpalign in [1,2,4,8,16,32,64,128]) or (s.jumpalign=256) then
       jumpalign:=s.jumpalign
     else if s.jumpalign<>0 then
       result:=false;
     { general update rules:
       minimum: if higher then update
       maximum: if lower then update or if undefined then update }
     if s.constalignmin>constalignmin then
      constalignmin:=s.constalignmin;
     if (constalignmax=0) or
        ((s.constalignmax>0) and (s.constalignmax<constalignmax)) then
      constalignmax:=s.constalignmax;
     if s.varalignmin>varalignmin then
      varalignmin:=s.varalignmin;
     if (varalignmax=0) or
        ((s.varalignmax>0) and (s.varalignmax<varalignmax)) then
      varalignmax:=s.varalignmax;
     if s.localalignmin>localalignmin then
      localalignmin:=s.localalignmin;
     if (localalignmax=0) or
        ((s.localalignmax>0) and (s.localalignmax<localalignmax)) then
      localalignmax:=s.localalignmax;
     if s.recordalignmin>recordalignmin then
      recordalignmin:=s.recordalignmin;
     if (recordalignmax=0) or
        ((s.recordalignmax>0) and (s.recordalignmax<recordalignmax)) then
      recordalignmax:=s.recordalignmax;
     if (maxCrecordalign=0) or
        ((s.maxCrecordalign>0) and (s.maxCrecordalign<maxCrecordalign)) then
      maxCrecordalign:=s.maxCrecordalign;
   end;
end;


{****************************************************************************
                              Target registration
****************************************************************************}

procedure RegisterTarget(const r:tsysteminfo);
var
  t : tsystem;
begin
  t:=r.system;
  if assigned(targetinfos[t]) then
   writeln('Warning: Target is already registered!')
  else
   Getmem(targetinfos[t],sizeof(tsysteminfo));
  targetinfos[t]^:=r;
end;


procedure RegisterRes(const r:tresinfo; rcf : TAbstractResourceFileClass);
var
  t : tres;
begin
  t:=r.id;
  if not assigned(resinfos[t]) then
    Getmem(resinfos[t],sizeof(tresinfo));
  resinfos[t]^:=r;
  resinfos[t]^.resourcefileclass:=rcf;
end;


procedure RegisterAr(const r:tarinfo);
var
  t : tar;
begin
  t:=r.id;
  if assigned(arinfos[t]) then
    writeln('Warning: ar is already registered!')
  else
    Getmem(arinfos[t],sizeof(tarinfo));
  arinfos[t]^:=r;
end;

procedure RegisterExternalLinker(var system_info: tsysteminfo; c:TAbstractLinkerClass);
begin
  system_info.linkextern := c;
end;

procedure RegisterInternalLinker(var system_info : tsysteminfo; c:TAbstractLinkerClass);
begin
  system_info.link := c;
end;



procedure DeregisterInfos;
var
  assem   : tasm;
  target  : tsystem;
  ar      : tar;
  res     : tres;
  dbg     : tdbg;
begin
  for target:=low(tsystem) to high(tsystem) do
   if assigned(targetinfos[target]) then
    begin
      freemem(targetinfos[target],sizeof(tsysteminfo));
      targetinfos[target]:=nil;
    end;
  for assem:=low(tasm) to high(tasm) do
   if assigned(asminfos[assem]) then
    begin
      freemem(asminfos[assem],sizeof(tasminfo));
      asminfos[assem]:=nil;
    end;
  for ar:=low(tar) to high(tar) do
   if assigned(arinfos[ar]) then
    begin
      freemem(arinfos[ar],sizeof(tarinfo));
      arinfos[ar]:=nil;
    end;
  for res:=low(tres) to high(tres) do
   if assigned(resinfos[res]) then
    begin
      freemem(resinfos[res],sizeof(tresinfo));
      resinfos[res]:=nil;
    end;
  for dbg:=low(tdbg) to high(tdbg) do
   if assigned(dbginfos[dbg]) then
    begin
      freemem(dbginfos[dbg],sizeof(tdbginfo));
      dbginfos[dbg]:=nil;
    end;
end;


{****************************************************************************
                      Initialization of default target
****************************************************************************}

procedure default_target(t:tsystem);
begin
  set_target(t);
  if source_info.name='' then
    source_info:=target_info;
end;


procedure set_source_info(const ti : tsysteminfo);
begin
{ can't use message() here (PFV) }
  if source_info.name<>'' then
    Writeln('Warning: Source OS Redefined!');
  source_info:=ti;
end;


procedure InitSystems;
begin
{ Now default target, this is dependent on the target cpu define,
  when the define is the same as the source cpu then we use the source
  os, else we pick a default }
{$ifdef i386}
  {$ifdef cpu86}
    default_target(source_info.system);
    {$define default_target_set}
  {$else cpu86}
   {$ifdef linux}
    default_target(system_i386_linux);
    {$define default_target_set}
   {$endif}
   {$ifdef freebsd}
    default_target(system_i386_freebsd);
    {$define default_target_set}
   {$endif}
   {$ifdef darwin}
    default_target(system_i386_darwin);
    {$define default_target_set}
   {$endif}
  {$endif cpu86}
  { default is linux }
  {$ifndef default_target_set}
   default_target(system_i386_linux);
  {$endif default_target_set}
{$endif i386}

{$ifdef x86_64}
  {$ifdef cpux86_64}
    default_target(source_info.system);
    {$define default_target_set}
  {$else cpux86_64}
   {$ifdef MSWindows}
    default_target(system_x86_64_win64);
    {$define default_target_set}
   {$endif}
   {$ifdef linux}
    default_target(system_x86_64_linux);
    {$define default_target_set}
   {$endif}
   {$ifdef freebsd}
    default_target(system_x86_64_freebsd);
    {$define default_target_set}
   {$endif}
   {$ifdef solaris}
    default_target(system_x86_64_solaris);
    {$define default_target_set}
   {$endif}
   {$ifdef darwin}
    default_target(system_x86_64_darwin);
    {$define default_target_set}
   {$endif}
  {$endif cpux86_64}
  { default is linux }
  {$ifndef default_target_set}
   default_target(system_x86_64_linux);
  {$endif default_target_set}
{$endif x86_64}

{$ifdef m68k}
  {$ifdef cpu68}
    default_target(source_info.target);
  {$else cpu68}
    default_target(system_m68k_linux);
  {$endif cpu68}
{$endif m68k}

{$ifdef alpha}
  {$ifdef cpualpha}
    default_target(source_info.system);
  {$else cpualpha}
    default_target(system_alpha_linux);
  {$endif cpualpha}
{$endif alpha}

{$ifdef powerpc}
  {$ifdef cpupowerpc}
    default_target(source_info.system);
    {$define default_target_set}
  {$else cpupowerpc}
   {$ifdef linux}
    default_target(system_powerpc_linux);
    {$define default_target_set}
   {$endif}
   {$ifdef darwin}
    default_target(system_powerpc_darwin);
    {$define default_target_set}
   {$endif}
  {$endif cpupowerpc}
  {$ifndef default_target_set}
    default_target(system_powerpc_linux);
  {$endif default_target_set}
{$endif powerpc}

{$ifdef POWERPC64}
  {$ifdef cpupowerpc64}
    default_target(source_info.system);
    {$define default_target_set}
  {$else cpupowerpc64}
    {$ifdef darwin}
     default_target(system_powerpc64_darwin);
     {$define default_target_set}
    {$endif}
    {$ifdef linux}
     default_target(system_powerpc64_linux);
     {$define default_target_set}
    {$endif}
  {$endif cpupowerpc64}
  {$ifndef default_target_set}
    default_target(system_powerpc64_linux);
    {$define default_target_set}
  {$endif}
{$endif POWERPC64}

{$ifdef sparc}
  {$ifdef cpusparc}
    default_target(source_info.system);
  {$else cpusparc}
    default_target(system_sparc_linux);
  {$endif cpusparc}
{$endif sparc}

{$ifdef arm}
  {$ifdef cpuarm}
    default_target(source_info.system);
  {$else cpuarm}
    {$ifdef WINDOWS}
      {$define default_target_set}
      default_target(system_arm_wince);
    {$endif}
    {$ifdef linux}
      {$define default_target_set}
      default_target(system_arm_linux);
    {$endif}
    {$ifdef darwin}
      {$define default_target_set}
      default_target(system_arm_darwin);
    {$endif}
    {$ifndef default_target_set}
      default_target(system_arm_linux);
      {$define default_target_set}
    {$endif}
  {$endif cpuarm}
{$endif arm}

{$ifdef avr}
  default_target(system_avr_embedded);
{$endif avr}

{$ifdef mips}
{$ifdef mipsel}
  default_target(system_mipsel_linux);
{$else mipsel}
  default_target(system_mips_linux);
{$endif mipsel}
{$endif mips}
end;


initialization
   source_info.name:='';
finalization
  DeregisterInfos;
end.