[Bug c/34389] New: -Wconversion produces wrong warning

["Raimund dot Merkert at baesystems dot com" <gcc-bugzilla at gcc dot gnu dot org>]

If compiled with gcc -c -Wconversion the following code produces the warning:
test.c:7: warning: conversion to ?short int? from ?int? may alter its value

but if -DNO_WARNING is turned on it doesn't even though it should be same code.

cat > test.c <<EOF
short  mask(short x)
{
#if NO_WARNING
  short y = 0x7fff;
  return x&y;
#else
  return x & (short)0x7fff;
#endif
}
EOF


On a side node, I think it would be better to also change the warning to :
"conversion from 'int' to 'short int' may alter its value", which i find easier
 to read.


-- 
           Summary: -Wconversion produces wrong warning
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: Raimund dot Merkert at baesystems dot com
GCC target triplet: gcc (GCC) 4.3.0 20071130 (experimental)


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34389