Delphi Error – E2591 Only cdecl functions may use varargs

Delphi Compiler Error

E2591 Only cdecl functions may use varargs

Reason for the Error & Solution

This error occurs whenever the varargs directive is used with non-cdecl functions.

function test(): Integer; varargs;
begin

end;

To fix this error, you need to declare your function with the external and cdecl directives:

function test(): Integer; varargs; cdecl; external 'externalLibrary.dll'; //This imports functions from a dynamically loadable library.
begin

end.

Note: This only occurs by compiling with the Delphi Mobile Compilers (dccios32, dcciosarm or dcciosarm64). Otherwise, the code produces .

See Also