Library libtest;

procedure Demo (var b: PWideChar; a: PWideChar); export;
begin
    //a := 'Hello'; // try to set initial value
    b := PWideChar(WideString(a) + '?!');
end;
   
    exports
        Demo;

begin
end.

MODULE TestLibDll ["libtest"];
   
   TYPE
      Pointer* = POINTER TO RECORD [untagged] END;
      WideString* = ARRAY [untagged] OF CHAR;
      PWideChar* = POINTER TO WideString;
   
   PROCEDURE Demo* (VAR b: PWideChar; a: PWideChar);
   
END TestLibDll.

MODULE TestDll;

   IMPORT SYSTEM, Lib := TestLibDll, Log := StdLog;
   
   (* int - показывать ли строку также и в числовом виде *)
   PROCEDURE WriteLn(IN s: ARRAY OF CHAR; int: BOOLEAN);
      VAR i: INTEGER;
   BEGIN
      IF int THEN
         FOR i := 0 TO LEN(s$) DO Log.Int(ORD(s[i])) END;
         Log.Ln
      END;
      Log.String("=>" + s  +"<="); Log.Ln;
   END WriteLn;
   
   PROCEDURE StrCpy(OUT dest: Lib.PWideChar; IN src: ARRAY OF CHAR);
      VAR l: INTEGER;
   BEGIN
      WriteLn(" src ", FALSE);
      WriteLn(src, FALSE);
      
      dest := src;
      
      WriteLn(" dest ", FALSE);
      
      (*l := SYSTEM.ADR(dest); Log.Int(l); Log.Ln;*)
      WriteLn(dest$, TRUE);
      
      WriteLn(" end ", FALSE);
   END StrCpy;
   
   PROCEDURE Run*;
      VAR
         a, b: Lib.PWideChar;
         s: ARRAY 64 OF CHAR;
   BEGIN
      StrCpy(a, "++++1234");
      
      WriteLn("===== Demo", FALSE);
      WriteLn(a$, TRUE);
      
      b := NIL;
      Lib.Demo(b, a);
      
      WriteLn(b$, TRUE);
      WriteLn("------ Demo", FALSE);
   END Run;
   
END TestDll.

=> src <=
=>++++1234<=
=> dest <=
 43 43 43 43 49 50 51 52 0
=>++++1234<=
=> end <=
=>===== Demo<=
 43 43 43 43 49 50 51 52 0
=>++++1234<=
 720 63 33 0
=>ː?!<=
=>------ Demo<=

type
    ByteArr = array [0.. 255] of byte;
    PByteArr = ^ByteArr;

const
    Lib = 'libtest.dll';
   
procedure Demo (var b: PWideChar; a: PWideChar); external Lib;
procedure Demo2 (var b: PAnsiChar; a: PAnsiChar); external Lib;

//procedure InsidePWideChar(s: PWideChar);
procedure InsidePAnsiChar(s: PAnsiChar);
var
    t: PByteArr;
    i: integer;
begin
    t := PByteArr(s);
    for i := 0 to 19 do
        write(t^[i]:4);
    writeln;
    for i := 0 to 19 do
        write(chr(t^[i]):4);
    writeln;
end;

var
    //p, s: PWideChar;
    p, s: PAnsiChar;
begin
    writeln('===');
    //p := PWideChar('Hello-');
    p := PAnsiChar('Hello-');
   
    writeln(AnsiString(p));
    //Demo(s, p);
    Demo2(s, p);

    //InsidePWideChar(s);
    InsidePAnsiChar(s);
    //writeln(WideString(s));
    writeln(AnsiString(s));
end.

P$LIBTEST_ADD$PWIDECHAR$PWIDECHAR$PWIDECHAR:
P$LIBTEST_ADD$PWIDECHAR$PWIDECHAR$PWIDECHAR:
; Temps allocated between ebp-68 and ebp-12
; [lib.pas]
; [4] begin
      push   ebp
      mov   ebp,esp
      sub   esp,68
      mov   dword ptr [ebp-68],ebx
; Var a located at ebp-4
; Var b located at ebp-8
; Var c located at ebp-12
      mov   dword ptr [ebp-4],eax
      mov   dword ptr [ebp-8],edx
      mov   dword ptr [ebp-12],ecx
...

P$LIBTEST_ADD$PWIDECHAR$PWIDECHAR$PWIDECHAR:
; Temps allocated between ebp-56 and ebp+0
; [lib.pas]
; [4] begin
      push   ebp
      mov   ebp,esp
      sub   esp,56
      mov   dword ptr [ebp-56],ebx
; Var a located at ebp+8
; Var b located at ebp+12
; Var c located at ebp+16

    END Add;

END TestDll.

ⓘ TestDll.Add
"a" "b"
"aa" "bb"
"123" "456"