[Qemu-devel] [PATCH] checkpatch: Error if signal(2) is used non-portably.

[Qemu-devel] [PATCH] checkpatch: Error if signal(2) is used non-portably.

[Richard W.M. Jones]

The only portable use for signal(2) is setting a signal to SIG_IGN or
SIG_DFL.  Everything else is a portability minefield.  This change
adds such a check to checkpatch.  It gives an error like this:

  ERROR: Use sigaction instead of signal, except when setting the handler to SIG_IGN or SIG_DFL
  #39: FILE: qemu-nbd.c:585:
  +    signal(SIGPIPE, foobar);

  total: 1 errors, 0 warnings, 10 lines checked

Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
---
 scripts/checkpatch.pl | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 45027b9281..76a2a87b25 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2593,6 +2593,15 @@ sub process {
 			$line =~ /\b(?:$non_exit_glib_asserts)\(/) {
 			ERROR("Use g_assert or g_assert_not_reached\n". $herecurr);
 		}
+
+# signal(2) can only portably be used for SIG_IGN or SIG_DFL.  For
+# everything else, sigaction should be used instead.
+                if ($line =~ /\bsignal\([^,]+, ([^,\)]+)/ &&
+                    $1 !~ /^SIG_(IGN|DFL)$/) {
+                    ERROR("Use sigaction instead of signal, ".
+                          "except when setting the handler to ".
+                          "SIG_IGN or SIG_DFL\n" . $herecurr);
+                }
 	}
 
 	# If we have no input at all, then there is nothing to report on
-- 
2.13.2

Re: [Qemu-devel] [PATCH] checkpatch: Error if signal(2) is used non-portably.

[Richard W.M. Jones]

Ignore this, Paolo also sent a similar patch after we were discussing
this on IRC.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-builder quickly builds VMs from scratch
http://libguestfs.org/virt-builder.1.html