Test cases and expecting failures

["D.Venkatasubramanian, Noida" <dvenkat at noida dot hcltech dot com>]

Hi,
I found that some test cases were failing for targets when the 
compiler was built with newlib. Now there are some targets which
can be built with newlib and otherwise also with libc. But test
cases like "gcc.dg/wint_t-1.c" should only fail if the target 
is built with newlib.

Another observation I made was that, in gcc.c-torture directory,
the test cases are unresolved by making a <test-case>.x file, but
 such files weren't present in other directories. I found similar
"Commands" formatted as comments in test cases itself in other 
directories. Any specific reason for this difference?

For example in File : "gcc.dg/wint_t-1.c"
/* { dg-excess-errors "Newlib has no wchar.h" { target mmix-knuth-mmixware
cris-*-elf } } */

I presume that to add some other target, say xxx-*-*, 
I would change this to,

/* { dg-excess-errors "Newlib has no wchar.h" { target mmix-knuth-mmixware
cris-*-elf xxx-*-* } } */

Am I thinking correctly? And what if I only want this to happen if
xxx-*-* is built with newlib.

Any help, pointer to documents on the web, etc. would be very helpful.
Thanks and regards,
Venky