getting gnu as to check the current location

[Alan Modra]

On Tue, Apr 13, 2010 at 01:36:16PM -0400, Harvey Chapman wrote:
> Is it possible with gnu as to do something like this?
> 
> .if (. - _start1) < 0x100 || (. - _start1) > 0x1ff
> 	.error	"some_label must be between 0x100 and 0x1FF!"
> .endif
> some_label:

It depends on what is between . and _start.  They must be in the same
section, and there can't be any .align or similar directives between.

-- 
Alan Modra
Australia Development Lab, IBM