Question

I just started learning Free Pascal and I wrote this fairly basic program to practise arrays. I get two errors:

Strings.lpr(32,1) Error: Undefined symbol: THREADVARLIST_STRINGS

Strings.lpr(32,1) Error: Undefined symbol: STRINGS_STRPAS$PCHAR$$SHORTSTRING

Strings.lpr(32,1) Fatal: There were 2 errors compiling module, stopping

The code is as follows:

program Strings;

{$mode objfpc}{$H+}

uses
  {$IFDEF UNIX}{$IFDEF UseCThreads}
  cthreads,
  {$ENDIF}{$ENDIF}
  Classes, SysUtils
  { you can add units after this };

{$R *.res}
var
  Marks : array [1..10] of Integer;
  index : Integer;
begin
  for index:= 0 to 10 do
  begin
    write('Enter mark of student ',index,': ');
    readln(marks[index]);
  end;

  for index := 0 to 10 do
  begin
    write('Student No. ',index,'   Marks: ',marks[index],'   ');
    if marks[index]>65 then writeln('PASS')
    else writeln('FAIL');
  end;

  writeln('Press any key to continue.');
  readln;
end. {line 32}

Answer 1

Don’t name your program strings. There is a precompiled unit with that name.

In general means that you create a mainprogram but don’t link a proper RTL.

Possible causes:

• Version conflicts, (compiler<>RTL)
• mistakes made by manual linking (trying to access Pascal from C?)
• trying to use an embedded RTL that doesn’t support certain language features.
• (your case) some naming conflict. But this is usually rare, and usually trapped by the compiler. Therefore, this experience might be worth filing as bug in the FPC bugtracker