{
    This file is part of the Free Pascal run time library.
    Copyright (c) 1999-2005 by Florian Klaempfl and Pavel Ozerski
    member of the Free Pascal development team.

    FPC Pascal system unit for the Win32 API.

    See the file COPYING.FPC, included in this distribution,
    for details about the copyright.

    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.

 **********************************************************************}
unit System;
interface

{$define FPC_IS_SYSTEM}
{$ifdef SYSTEMDEBUG}
  {$define SYSTEMEXCEPTIONDEBUG}
{$endif SYSTEMDEBUG}

{$ifdef VER3_0}
{ 3.1.1+ do not require this anymore }
{$define FPC_HAS_INDIRECT_ENTRY_INFORMATION}
{$endif VER3_0}

{$ifdef cpui386}
  {$define Set_i386_Exception_handler}
{$endif cpui386}

{$define DISABLE_NO_THREAD_MANAGER}
{$define HAS_WIDESTRINGMANAGER}
{$define DISABLE_NO_DYNLIBS_MANAGER}
{$define FPC_SYSTEM_HAS_SYSDLH}
{$define FPC_HAS_SETCTRLBREAKHANDLER}

{$ifdef FPC_USE_WIN32_SEH}
  {$define FPC_SYSTEM_HAS_RAISEEXCEPTION}
  {$define FPC_SYSTEM_HAS_RERAISE}
  {$define FPC_SYSTEM_HAS_DONEEXCEPTION}
  {$define FPC_SYSTEM_HAS_SAFECALLHANDLER}
{$endif FPC_USE_WIN32_SEH}

{ include system-independent routine headers }
{$I systemh.inc}
{ include common windows headers }
{$I syswinh.inc}

var
  MainInstance : longint;

implementation

var
  FPCSysInstance : PLongint;public name '_FPC_SysInstance';

{$define FPC_SYSTEM_HAS_OSSETUPENTRYINFORMATION}
procedure OsSetupEntryInformation(constref info: TEntryInformation); forward;

{$ifdef FPC_USE_WIN32_SEH}
function main_wrapper(arg: Pointer; proc: Pointer): ptrint; forward;
procedure OutermostHandler; external name '__FPC_DEFAULT_HANDLER';
{$endif FPC_USE_WIN32_SEH}

{$define FPC_SYSTEM_HAS_STACKTOP}
function StackTop: pointer; assembler;nostackframe;
asm
   movl  %fs:(4),%eax
end;

{ include system independent routines }
{$I system.inc}

{ include code common with win64 }
{$I syswin.inc}

procedure OsSetupEntryInformation(constref info: TEntryInformation);
begin
  TlsKey := info.OS.TlsKeyAddr;
  FPCSysInstance := info.OS.SysInstance;
  WStrInitTablesTable := info.OS.WideInitTables;
end;

{*****************************************************************************
                         System Dependent Exit code
*****************************************************************************}

{$ifndef FPC_USE_WIN32_SEH}
procedure install_exception_handlers;forward;
procedure remove_exception_handlers;forward;
{$endif FPC_USE_WIN32_SEH}

Procedure system_exit;
begin
  if IsLibrary then
  begin
    { If exiting from DLL_PROCESS_ATTACH/DETACH, unwind to DllMain context. }
    if DllInitState in [DLL_PROCESS_ATTACH,DLL_PROCESS_DETACH] then
      LongJmp(DLLBuf,1)
    else
    { Abnormal termination, Halt has been called from DLL function,
      put down the entire process (DLL_PROCESS_DETACH will still
      occur). At this point RTL has been already finalized in InternalExit
      and shouldn't be finalized another time in DLL_PROCESS_DETACH.
      Indicate this by resetting MainThreadIdWin32. }
      MainThreadIDWin32:=0;
  end;
  if not IsConsole then
   begin
     Close(stderr);
     Close(stdout);
     Close(erroutput);
     Close(Input);
     Close(Output);
     { what about Input and Output ?? PM }
     { now handled, FPK }
   end;
{$ifndef FPC_USE_WIN32_SEH}
  if not IsLibrary then
    remove_exception_handlers;
{$endif FPC_USE_WIN32_SEH}

  { do cleanup required by the startup code }
  EntryInformation.OS.asm_exit();

  { call exitprocess, with cleanup as required }
  ExitProcess(exitcode);
end;

var
  { value of the stack segment
    to check if the call stack can be written on exceptions }
  _SS : Cardinal;

procedure Exe_entry(constref info : TEntryInformation);[public,alias:'_FPC_EXE_Entry'];
  var
    xframe: TEXCEPTION_FRAME;
  begin
     SetupEntryInformation(info);
     IsLibrary:=false;
     { install the handlers for exe only ?
       or should we install them for DLL also ? (PM) }
{$ifndef FPC_USE_WIN32_SEH}
     install_exception_handlers;
{$endif FPC_USE_WIN32_SEH}
     { This strange construction is needed to solve the _SS problem
       with a smartlinked syswin32 (PFV) }
     asm
        { movl  %esp,%fs:(0)
          but don't insert it as it doesn't
          point to anything yet
          this will be used in signals unit }
        leal xframe,%eax
        movl %fs:(0),%ecx
        movl %ecx,TException_Frame.next(%eax)
        movl %eax,System_exception_frame
{$ifndef FPC_USE_WIN32_SEH}
        movl $0,TException_Frame.handler(%eax)
{$else}
        movl $OutermostHandler,TException_Frame.handler(%eax)
        movl %eax,%fs:(0)
{$endif FPC_USE_WIN32_SEH}
        pushl %ebp
        xorl %eax,%eax
        movw %ss,%ax
        movl %eax,_SS
        xorl %ebp,%ebp
     end;
     EntryInformation.PascalMain();
     asm
        popl %ebp
     end;
     { if we pass here there was no error ! }
     system_exit;
  end;

function is_prefetch(p : pointer) : boolean;
  var
    a : array[0..15] of byte;
    doagain : boolean;
    instrlo,instrhi,opcode : byte;
    i : longint;
  begin
    result:=false;
    { read memory savely without causing another exeception }
    if not(ReadProcessMemory(GetCurrentProcess,p,@a,sizeof(a),nil)) then
      exit;
    i:=0;
    doagain:=true;
    while doagain and (i<15) do
      begin
        opcode:=a[i];
        instrlo:=opcode and $f;
        instrhi:=opcode and $f0;
        case instrhi of
          { prefix? }
          $20,$30:
            doagain:=(instrlo and 7)=6;
          $60:
            doagain:=(instrlo and $c)=4;
          $f0:
            doagain:=instrlo in [0,2,3];
          $0:
            begin
              result:=(instrlo=$f) and (a[i+1] in [$d,$18]);
              exit;
            end;
          else
            doagain:=false;
        end;
        inc(i);
      end;
  end;

//
// Hardware exception handling
//

{$ifdef Set_i386_Exception_handler}

type
  PFloatingSaveArea = ^TFloatingSaveArea;
  TFloatingSaveArea = packed record
          ControlWord : Cardinal;
          StatusWord : Cardinal;
          TagWord : Cardinal;
          ErrorOffset : Cardinal;
          ErrorSelector : Cardinal;
          DataOffset : Cardinal;
          DataSelector : Cardinal;
          RegisterArea : array[0..79] of Byte;
          Cr0NpxState : Cardinal;
  end;

  PContext = ^TContext;
  TContext = packed record
      //
      // The flags values within this flag control the contents of
      // a CONTEXT record.
      //
          ContextFlags : Cardinal;

      //
      // This section is specified/returned if CONTEXT_DEBUG_REGISTERS is
      // set in ContextFlags.  Note that CONTEXT_DEBUG_REGISTERS is NOT
      // included in CONTEXT_FULL.
      //
          Dr0, Dr1, Dr2,
          Dr3, Dr6, Dr7 : Cardinal;

      //
      // This section is specified/returned if the
      // ContextFlags word contains the flag CONTEXT_FLOATING_POINT.
      //
          FloatSave : TFloatingSaveArea;

      //
      // This section is specified/returned if the
      // ContextFlags word contains the flag CONTEXT_SEGMENTS.
      //
          SegGs, SegFs,
          SegEs, SegDs : Cardinal;

      //
      // This section is specified/returned if the
      // ContextFlags word contains the flag CONTEXT_INTEGER.
      //
          Edi, Esi, Ebx,
          Edx, Ecx, Eax : Cardinal;

      //
      // This section is specified/returned if the
      // ContextFlags word contains the flag CONTEXT_CONTROL.
      //
          Ebp : Cardinal;
          Eip : Cardinal;
          SegCs : Cardinal;
          EFlags, Esp, SegSs : Cardinal;

      //
      // This section is specified/returned if the ContextFlags word
      // contains the flag CONTEXT_EXTENDED_REGISTERS.
      // The format and contexts are processor specific
      //
          ExtendedRegisters : array[0..MAXIMUM_SUPPORTED_EXTENSION-1] of Byte;
  end;


  PExceptionPointers = ^TExceptionPointers;
  TExceptionPointers = packed record
          ExceptionRecord   : PExceptionRecord;
          ContextRecord     : PContext;
  end;

{ type of functions that should be used for exception handling }
  TTopLevelExceptionFilter = function (excep : PExceptionPointers) : Longint;stdcall;

{$i seh32.inc}

{$ifndef FPC_USE_WIN32_SEH}
function SetUnhandledExceptionFilter(lpTopLevelExceptionFilter : TTopLevelExceptionFilter) : TTopLevelExceptionFilter;
        stdcall;external 'kernel32' name 'SetUnhandledExceptionFilter';

const
  MaxExceptionLevel = 16;
  exceptLevel : Byte = 0;

var
  exceptEip       : array[0..MaxExceptionLevel-1] of Longint;
  exceptError     : array[0..MaxExceptionLevel-1] of Byte;
  resetFPU        : array[0..MaxExceptionLevel-1] of Boolean;

{$ifdef SYSTEMEXCEPTIONDEBUG}
procedure DebugHandleErrorAddrFrame(error : longint; addr, frame : pointer);
begin
  if IsConsole then
    begin
      write(stderr,'HandleErrorAddrFrame(error=',error);
      write(stderr,',addr=',hexstr(ptruint(addr),8));
      writeln(stderr,',frame=',hexstr(ptruint(frame),8),')');
    end;
  HandleErrorAddrFrame(error,addr,frame);
end;
{$endif SYSTEMEXCEPTIONDEBUG}

procedure JumpToHandleErrorFrame;
  var
    eip, ebp, error : Longint;
  begin
    // save ebp
    asm
      movl (%ebp),%eax
      movl %eax,ebp
    end;
    if (exceptLevel > 0) then
      dec(exceptLevel);

    eip:=exceptEip[exceptLevel];
    error:=exceptError[exceptLevel];
{$ifdef SYSTEMEXCEPTIONDEBUG}
    if IsConsole then
      writeln(stderr,'In JumpToHandleErrorFrame error=',error);
{$endif SYSTEMEXCEPTIONDEBUG}
    if resetFPU[exceptLevel] then
      SysResetFPU;
    { build a fake stack }
    asm
      movl   ebp,%ecx
      movl   eip,%edx
      movl   error,%eax
      pushl  eip
      movl   ebp,%ebp // Change frame pointer

{$ifdef SYSTEMEXCEPTIONDEBUG}
      jmpl   DebugHandleErrorAddrFrame
{$else not SYSTEMEXCEPTIONDEBUG}
      jmpl   HandleErrorAddrFrame
{$endif SYSTEMEXCEPTIONDEBUG}
    end;
  end;

function syswin32_i386_exception_handler(excep : PExceptionPointers) : Longint;stdcall;
  var
    res,ssecode: longint;
    err: byte;
    must_reset_fpu: boolean;
  begin
    res := EXCEPTION_CONTINUE_SEARCH;
    if excep^.ContextRecord^.SegSs=_SS then begin
      err := 0;
      must_reset_fpu := true;
{$ifdef SYSTEMEXCEPTIONDEBUG}
      if IsConsole then Writeln(stderr,'Exception  ',
              hexstr(excep^.ExceptionRecord^.ExceptionCode, 8));
{$endif SYSTEMEXCEPTIONDEBUG}
      case excep^.ExceptionRecord^.ExceptionCode of
        STATUS_INTEGER_DIVIDE_BY_ZERO :
          err := 200;
        STATUS_FLOAT_DIVIDE_BY_ZERO :
          err := 208;
        STATUS_ARRAY_BOUNDS_EXCEEDED :
          begin
            err := 201;
            must_reset_fpu := false;
          end;
        STATUS_STACK_OVERFLOW :
          begin
            err := 202;
            must_reset_fpu := false;
          end;
        STATUS_FLOAT_OVERFLOW :
          err := 205;
        STATUS_FLOAT_DENORMAL_OPERAND,
        STATUS_FLOAT_UNDERFLOW :
          err := 206;
    {excep^.ContextRecord^.FloatSave.StatusWord := excep^.ContextRecord^.FloatSave.StatusWord and $ffffff00;}
        STATUS_FLOAT_INEXACT_RESULT,
        STATUS_FLOAT_INVALID_OPERATION,
        STATUS_FLOAT_STACK_CHECK :
          err := 207;
        STATUS_INTEGER_OVERFLOW :
          begin
            err := 215;
            must_reset_fpu := false;
          end;
        STATUS_ILLEGAL_INSTRUCTION:
          { if we're testing sse support, simply set the flag and continue }
          if sse_check then
            begin
              os_supports_sse:=false;
              { skip the offending movaps %xmm7, %xmm6 instruction }
              inc(excep^.ContextRecord^.Eip,3);
              excep^.ExceptionRecord^.ExceptionCode := 0;
              res:=EXCEPTION_CONTINUE_EXECUTION;
            end
          else
            err := 216;
        STATUS_ACCESS_VIOLATION:
          { Athlon prefetch bug? }
          if is_prefetch(pointer(excep^.ContextRecord^.Eip)) then
            begin
              { if yes, then retry }
              excep^.ExceptionRecord^.ExceptionCode := 0;
              res:=EXCEPTION_CONTINUE_EXECUTION;
            end
          else
            err := 216;

        STATUS_CONTROL_C_EXIT:
          err := 217;
        STATUS_PRIVILEGED_INSTRUCTION:
          begin
            err := 218;
            must_reset_fpu := false;
          end;
        STATUS_FLOAT_MULTIPLE_FAULTS,
        STATUS_FLOAT_MULTIPLE_TRAPS:
          begin
            { dumping ExtendedRegisters and comparing with the actually value of mxcsr revealed 24 }
            TranslateMxcsr(excep^.ContextRecord^.ExtendedRegisters[24],ssecode);
{$ifdef SYSTEMEXCEPTIONDEBUG}
            if IsConsole then
              Writeln(stderr,'MXSR: ',hexstr(excep^.ContextRecord^.ExtendedRegisters[24], 2),' SSECODE: ',ssecode);
{$endif SYSTEMEXCEPTIONDEBUG}
            err:=-ssecode;
          end;
        else
          begin
            if ((excep^.ExceptionRecord^.ExceptionCode and SEVERITY_ERROR) = SEVERITY_ERROR) then
              err := 217
            else
              err := 255;
          end;
      end;

      if (err <> 0) and (exceptLevel < MaxExceptionLevel) then begin
        exceptEip[exceptLevel] := excep^.ContextRecord^.Eip;
        exceptError[exceptLevel] := err;
        resetFPU[exceptLevel] := must_reset_fpu;
        inc(exceptLevel);

        excep^.ContextRecord^.Eip := Longint(@JumpToHandleErrorFrame);
        excep^.ExceptionRecord^.ExceptionCode := 0;

        res := EXCEPTION_CONTINUE_EXECUTION;
{$ifdef SYSTEMEXCEPTIONDEBUG}
        if IsConsole then begin
          writeln(stderr,'Exception Continue Exception set at ',
                  hexstr(exceptEip[exceptLevel],8));
          writeln(stderr,'Eip changed to ',
                  hexstr(longint(@JumpToHandleErrorFrame),8), ' error=', err);
        end;
{$endif SYSTEMEXCEPTIONDEBUG}
      end;
    end;
    syswin32_i386_exception_handler := res;
  end;

procedure install_exception_handlers;
  begin
    SetUnhandledExceptionFilter(@syswin32_i386_exception_handler);
  end;

procedure remove_exception_handlers;
  begin
    SetUnhandledExceptionFilter(nil);
  end;
{$endif not FPC_USE_WIN32_SEH}

{$else not cpui386 (Processor specific !!)}
procedure install_exception_handlers;
begin
end;

procedure remove_exception_handlers;
begin
end;
{$endif Set_i386_Exception_handler}

{$ifdef FPC_SECTION_THREADVARS}
function fpc_tls_add(addr: pointer): pointer; assembler; nostackframe;
  [public,alias: 'FPC_TLS_ADD']; compilerproc;
  asm
      sub   $tls_data_start,%eax
      cmpb  $0,IsLibrary
      mov   _tls_index,%ecx
      jnz   .L1
      mov   %fs:(0x2c),%edx
      add   (%edx,%ecx,4),%eax
      ret
.L1:
      push  %ebx
      mov   %eax,%ebx
      call  GetLastError
      push  %eax                      { save LastError }
      push  _tls_index
      call  TlsGetValue
      test  %eax,%eax
      jnz   .L2
      { This can happen when a thread existed before DLL was loaded,
        or if DisableThreadLibraryCalls was called. }
      call  SysAllocateThreadVars
      mov   $0x1000000,%eax
      call  InitThread
      push  _tls_index
      call  TlsGetValue
.L2:
      add   %eax,%ebx
      call  SetLastError              { restore (value is on stack) }
      mov   %ebx,%eax
      pop   %ebx
  end;
{$endif FPC_SECTION_THREADVARS}

function CheckInitialStkLen(stklen : SizeUInt) : SizeUInt;
  type
    tdosheader = packed record
       e_magic : word;
       e_cblp : word;
       e_cp : word;
       e_crlc : word;
       e_cparhdr : word;
       e_minalloc : word;
       e_maxalloc : word;
       e_ss : word;
       e_sp : word;
       e_csum : word;
       e_ip : word;
       e_cs : word;
       e_lfarlc : word;
       e_ovno : word;
       e_res : array[0..3] of word;
       e_oemid : word;
       e_oeminfo : word;
       e_res2 : array[0..9] of word;
       e_lfanew : longint;
    end;
    tpeheader = packed record
       PEMagic : longint;
       Machine : word;
       NumberOfSections : word;
       TimeDateStamp : longint;
       PointerToSymbolTable : longint;
       NumberOfSymbols : longint;
       SizeOfOptionalHeader : word;
       Characteristics : word;
       Magic : word;
       MajorLinkerVersion : byte;
       MinorLinkerVersion : byte;
       SizeOfCode : longint;
       SizeOfInitializedData : longint;
       SizeOfUninitializedData : longint;
       AddressOfEntryPoint : longint;
       BaseOfCode : longint;
       BaseOfData : longint;
       ImageBase : longint;
       SectionAlignment : longint;
       FileAlignment : longint;
       MajorOperatingSystemVersion : word;
       MinorOperatingSystemVersion : word;
       MajorImageVersion : word;
       MinorImageVersion : word;
       MajorSubsystemVersion : word;
       MinorSubsystemVersion : word;
       Reserved1 : longint;
       SizeOfImage : longint;
       SizeOfHeaders : longint;
       CheckSum : longint;
       Subsystem : word;
       DllCharacteristics : word;
       SizeOfStackReserve : longint;
       SizeOfStackCommit : longint;
       SizeOfHeapReserve : longint;
       SizeOfHeapCommit : longint;
       LoaderFlags : longint;
       NumberOfRvaAndSizes : longint;
       DataDirectory : array[1..$80] of byte;
    end;
  begin
    result:=tpeheader((pointer(getmodulehandle(nil))+(tdosheader(pointer(getmodulehandle(nil))^).e_lfanew))^).SizeOfStackReserve;
  end;

initialization
  { get some helpful informations }
  GetStartupInfo(@startupinfo);
  { some misc Win32 stuff }
  if not IsLibrary then
    FPCSysInstance^:=getmodulehandle(nil);

  MainInstance:=FPCSysInstance^;

  { pass dummy value }
  StackLength := CheckInitialStkLen($1000000);
  StackBottom := StackTop - StackLength;

  cmdshow:=startupinfo.wshowwindow;
  { Setup heap and threading, these may be already initialized from TLS callback }
  if not Assigned(CurrentTM.BeginThread) then
  begin
    InitHeap;
    InitSystemThreads;
  end;
  SysInitExceptions;
  { setup fastmove stuff }
  fpc_cpucodeinit;
  initunicodestringmanager;
  InitWin32Widestrings;
  SysInitStdIO;
  { Arguments }
  setup_arguments;
  InitSystemDynLibs;
  { Reset IO Error }
  InOutRes:=0;
  ProcessID := GetCurrentProcessID;
  DispCallByIDProc:=@DoDispCallByIDError;

finalization
  WinFinalizeSystem;

end.