[7171] in Athena Bugs
rt 7.1H: hcc flames unnecessarily
daemon@ATHENA.MIT.EDU (daemon@ATHENA.MIT.EDU)
Fri Feb 22 22:42:52 1991
From: tytso@MIT.EDU
To: bugs@ATHENA.MIT.EDU
Date: Fri, 22 Feb 91 22:42:33 EST
System name: delwin
Type and version: RTPC-ROMPC 7.1H
Display type: apa16
What were you trying to do?
Compile a program
What's wrong:
Hcc complained with the following error message:
w "page.c",L784/C37: 0: Expression has no side-effects.
Where line 784 contained:
sigaddset(&set, SIGHUP);
and sigaddset is defined to be
#define sigaddset(set,signo) (*(set) |= sigmask(signo), 0)
It's not realizing that while '0' has no side effects, the entire
expression has a side effect, and it should have kept it's big mouth
shut.
What should have happened:
It shouldn't have issued this warning.
Please describe any relevant documentation references:
K&R
