[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 <address@hidden>
---
 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