`-W' This is a general option similar to `-Wall' which warns about a
selection of common programming errors, such as functions which
can return without a value (also known as ``falling off the end of
the function body''), and comparisons between signed and unsigned
values. For example, the following function tests whether an un-
signed integer is negative (which is impossible, of course):
int
foo (unsigned int x)
{
if (x < 0)
return 0; /* cannot occur */
else
return 1;
}
Compiling this function with `-Wall' does not produce a warning...1