dos_compilers/Borland Turbo Pascal v4/CPASDEMO.PAS

{           Copyright (c) 1985, 87 by Borland International, Inc.            }

program CPASDEMO;
(*
  This program demonstrates how to interface Turbo Pascal and Turbo C.
  Turbo C is used to generate an .OBJ file (CPASDEMO.OBJ). Then
  this .OBJ is linked into this Turbo Pascal program using the {$L}
  compiler directive.

  NOTES:
    1. Data declared in the Turbo C module cannot be accessed from
       the Turbo Pascal program. Shared data must be declared in
       Pascal.

    2. If the C functions are only used in the implementation section
       of a unit, declare them NEAR.  If they are declared in the
       interface section of a unit, declare them FAR.  Always compile
       the Turbo C modules using the small memory model.

    3. Turbo C runtime library routines cannot be used because their
       modules do not have the correct segment names.  However, if you have
       the Turbo C runtime library source (available from Borland),
       you can use individual library modules by recompiling
       them using CTOPAS.BAT.  If you do recompile them, make sure
       that you include prototypes in your C module for all C
       library functions that you use.

    4. Some of the code that Turbo C generates are calls to internal
       routines. These cannot be used without recompiling the relevant
       parts of the Turbo C runtime library source code.

  In order to run this demonstration program you will need the following
  files:

    TCC.EXE and TURBO.CFG or
    TC.EXE and CTOPAS.TC

  To run the demonstration program CPASDEMO.EXE do the following:
  
  1. First create a CPASDEMO.OBJ file compatible with Turbo Pascal 4.0
     using Turbo C.

    a) If you are using the Turbo C integrated environment (TC.EXE)
       then at the DOS prompt execute:

       TC /CCTOPAS.TC CPASDEMO.C
       
       then create the .OBJ file by pressing ALT-F9.

    b) If you are using the Turbo C command line version (TCC.EXE)
       then at the DOS prompt execute:

       TCC CPASDEMO.C

       Note: Use the same configuration file (TURBO.CFG or CTOPAS.TC)
             when you create your own Turbo C modules for use with
             Turbo Pascal 4.0

  2. Compile and execute the Turbo Pascal program CPASDEMO.PAS

  This simple program calls each of the functions defined in the Turbo C
  module. Each of the Turbo C functions changes the current display color
  by calling the Turbo Pascal procedure SetColor. }
*)

uses Crt;

var
  Factor : Word;

{$L CPASDEMO.OBJ}  { link in the Turbo C-generated .OBJ module }

function Sqr(I : Integer) : Word; external;
{ Change the text color and return the square of I }

function HiBits(W : Word) : Word; external;
{ Change the text color and return the high byte of W }

function Suc(B : Byte) : Byte; external;
{ Change the text color and return B + 1 }

function Upr(C : Char) : Char; external;
{ Change the text color and return the upper case of C }

function Prd(S : ShortInt) : ShortInt; external;
{ Change the text color and return S - 1 }

function LoBits(L : LongInt) : LongInt; external;
{ Change the text color and return the low word of L }

procedure StrUpr(var S : string); external;
{ Change the text color and return the upper case of S - Note that the Turbo }
{ C routine must skip the length byte of the string.                         }

function BoolNot(B : Boolean) : Boolean; external;
{ Change the text color and return NOT B }

function MultByFactor(W : Word) : Word; external;
{ Change the text color and return W * Factor - note Turbo C's access of }
{ Turbo Pascal's global variable.                                        }

procedure SetColor(NewColor : Byte); { A procedure that changes the current }
begin                                { display color by changing the CRT    }
  TextAttr := NewColor;              { variable TextAttr                    }
end; { SetColor }

var
  S : string;

begin
  Writeln(Sqr(10));                  { Call each of the functions defined   }
  Writeln(HiBits(30000));            { passing it the appropriate info.     }
  Writeln(Suc(200));
  Writeln(Upr('x'));
  Writeln(Prd(-100));
  Writeln(LoBits(100000));
  S := 'abcdefg';
  StrUpr(S);
  Writeln(S);
  Writeln(BoolNot(False));
  Factor := 100;
  Writeln(MultbyFactor(10));
  SetColor(LightGray);
end.