SYNOPSIS
	string expand_define (string name)
	string expand_define (string name, string arg, ...)

DESCRIPTION
	Expands the macro <name> with the argument(s) <arg>... (default is
	one empty string "").
	Result is the expanded macro, or 0 if there is no macro with
	that name.

	This efun is applicable only while an object is compiled,
	therefore its usage is restricted to a few functions like the
	H_INCLUDE_DIRS driver hook, or the masters runtime_error()
	function.

EXAMPLE
	While compiling 'foo.c':
	  expand_define("__FILE__") --> "file.c"

HISTORY
	Introduced in 3.2.1@93.

SEE ALSO
	hooks(C), runtime_error(M)
