[Bug tree-optimization/21733] New: filecmp.c:252: warning: #n1# may be used uninitialized in this function

["olh at suse dot de" <gcc-bugzilla@gcc.gnu.org>]

if I understand the code flow in FileCmpCmd correctly,
the first loop will initialize n1 and n2 because e1 = e2 = 0,
and k1 && k2 is always < BSIZE.
Even if the read() will return an error, the last check
to return either TCL_ERROR or TCL_OK is not undefined.


This is from http://ozlabs.org/~paulus/dirdiff-2.1.tar.gz

/usr/lib/gcc/powerpc64-suse-linux/4.0.1/cc1 -fpreprocessed filecmp.i -quiet -dumpbase filecmp.c -auxbase filecmp -O3 -Wall -version -fPIC -o filecmp.s
GNU C version 4.0.1 20050521 (prerelease) (SUSE Linux) (powerpc64-suse-linux)
        compiled by GNU C version 4.0.1 20050521 (prerelease) (SUSE Linux).
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
filecmp.c: In function #FileCmpCmd#:
filecmp.c:252: warning: #n2# may be used uninitialized in this function
filecmp.c:252: warning: #n1# may be used uninitialized in this function

-- 
           Summary: filecmp.c:252: warning: #n1# may be used uninitialized
                    in this function
           Product: gcc
           Version: 4.0.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: olh at suse dot de
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: powerpc-linux
  GCC host triplet: powerpc-linux
GCC target triplet: powerpc-linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21733