Compiling
#include <sys/select.h>
void f(int X)
{
fd_set set;
FD_ZERO(&set);
FD_SET(X,&set);
FD_CLR(X+1,&set);
(void)FD_ISSET(X+2,&set);
}
results in plenty of gcc warnings when compiled with
-Wconversion -Wsign-conversion:
fds.c:7:2: warning: conversion to ‘long unsigned int’ from ‘int’ may
FD_SET(X,&set);
^~~~~~
[...]
The unsigned NFDBITS macro combined with the signed 1L constant
are causing lots of implicit signed/unsigned type conversions.
Fix this by updating the FD_* macro code to the latest from FreeBSD
and adding an (int) cast to _NFDBITS.
As a side-effect, this fixes the visibility of NFDBITS and
fds_bits (only if __BSD_VISIBLE).
This also eliminates the old, outdated fd_set workaround.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
748b416ab9