From mboxrd@z Thu Jan  1 00:00:00 1970
From: Zack Weinberg <zack@rabi.columbia.edu>
To: egcs@egcs.cygnus.com
Subject: added: tests for uninit variable warnings
Date: Wed, 31 Mar 1999 23:46:00 -0000
Message-ID: <199903120010.TAA03507@blastula.phys.columbia.edu>
X-SW-Source: 1999-03n/msg00437.html
Message-ID: <19990331234600.uiHUXx2Ttj6OE3JYkpgAoMgqa6jF-VCXcR4gljGCqGE@z>

I've added to the testsuite the files gcc.dg/uninit-[1234].c.  These
are tests for spurious uninitialized variable warnings.  uninit-1.c
and uninit-3.c are understandable weaknesses in data flow analysis.
uninit-2.c is slightly less understandable.  It ought to recognize
that rest_args cannot be nonzero on the first trip through the loop.

uninit-4.c is bizarre: the warning goes away if you remove the '1'
case, or if you replace 'struct operation' by an int, or even if you
make 'struct operation' smaller!  Also, if you take out the default
case _and_ the '1' case, the warning goes away, but it shouldn't (what
if cpp_lex returns 3?)

The tests are marked XFAIL - all systems.  I'm interested to know if
they pass on anyone's machine.

Note that any improvements that lead to uninit-[123] passing will
probably also lead to better loop optimization.

zw