qemu-e2k/scripts/tracetool/format/d.py
Stefan Hajnoczi b33b890cd0 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: 23c3d569f4 ("target/hppa: add TLB trace events")
Reported-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Message-id: 20190321170831.6539-3-stefanha@redhat.com
Message-Id: <20190321170831.6539-3-stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-03-22 15:55:50 +00:00

60 lines
1.7 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
trace/generated-tracers.dtrace (DTrace only).
"""
__author__ = "Lluís Vilanova <vilanova@ac.upc.edu>"
__copyright__ = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
__license__ = "GPL version 2 or (at your option) any later version"
__maintainer__ = "Stefan Hajnoczi"
__email__ = "stefanha@linux.vnet.ibm.com"
from tracetool import out
# Reserved keywords from
# https://wikis.oracle.com/display/DTrace/Types,+Operators+and+Expressions
RESERVED_WORDS = (
'auto', 'goto', 'sizeof', 'break', 'if', 'static', 'case', 'import',
'string', 'char', 'inline', 'stringof', 'const', 'int', 'struct',
'continue', 'long', 'switch', 'counter', 'offsetof', 'this',
'default', 'probe', 'translator', 'do', 'provider', 'typedef',
'double', 'register', 'union', 'else', 'restrict', 'unsigned',
'enum', 'return', 'void', 'extern', 'self', 'volatile', 'float',
'short', 'while', 'for', 'signed', 'xlate',
)
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 {')
for e in events:
args = []
for type_, name in e.args:
if name in RESERVED_WORDS:
name += '_'
args.append(type_ + ' ' + name)
# Define prototype for probe arguments
out('',
'probe %(name)s(%(args)s);',
name=e.name,
args=','.join(args))
out('',
'};')