From b33b890cd07eca1d05cd8c4f5f03790f0585423f Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 21 Mar 2019 17:08:31 +0000 Subject: [PATCH] trace: avoid SystemTap dtrace(1) warnings on empty files target/hppa/trace-events only contains disabled events, resulting in a trace-dtrace.dtrace file that says "provider qemu {}". SystemTap's dtrace(1) tool prints a warning when processing this input file. This patch avoids the error by emitting an empty file instead of "provider qemu {}" when there are no enabled trace events. Fixes: 23c3d569f44284066714ff7c46bc4f19e630583f ("target/hppa: add TLB trace events") Reported-by: Markus Armbruster Signed-off-by: Stefan Hajnoczi Reviewed-by: Markus Armbruster Reviewed-by: Liam Merwick Message-id: 20190321170831.6539-3-stefanha@redhat.com Message-Id: <20190321170831.6539-3-stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi --- scripts/tracetool/format/d.py | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/scripts/tracetool/format/d.py b/scripts/tracetool/format/d.py index 78397c24d2..c7cb2a93a6 100644 --- a/scripts/tracetool/format/d.py +++ b/scripts/tracetool/format/d.py @@ -33,6 +33,11 @@ def generate(events, backend, group): events = [e for e in events if "disable" not in e.properties] + # SystemTap's dtrace(1) warns about empty "provider qemu {}" but is happy + # with an empty file. Avoid the warning. + if not events: + return + out('/* This file is autogenerated by tracetool, do not edit. */' '', 'provider qemu {')