qemu/scripts/tracetool/backend/dtrace.py
Stefan Hajnoczi 27e08bab94 tracetool: work around ust <sys/sdt.h> include conflict
Both the dtrace and ust backends may include <sys/sdt.h> but LTTng
Userspace Tracer 2.11 and later requires SDT_USE_VARIADIC to be defined
before including the header file.

This is a classic problem with C header files included from different
parts of a program. If the same header is included twice within the same
compilation unit then the first inclusion determines the macro
environment.

Work around this by defining SDT_USE_VARIADIC in the dtrace backend too.
It doesn't hurt and fixes a missing STAP_PROBEV() compiler error when
the ust backend is enabled together with the dtrace backend.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200625140757.237012-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-07-07 16:07:14 +01:00

69 lines
1.7 KiB
Python

# -*- coding: utf-8 -*-
"""
DTrace/SystemTAP backend.
"""
__author__ = "Lluís Vilanova <vilanova@ac.upc.edu>"
__copyright__ = "Copyright 2012-2017, Lluís Vilanova <vilanova@ac.upc.edu>"
__license__ = "GPL version 2 or (at your option) any later version"
__maintainer__ = "Stefan Hajnoczi"
__email__ = "stefanha@redhat.com"
from tracetool import out
PUBLIC = True
PROBEPREFIX = None
def probeprefix():
if PROBEPREFIX is None:
raise ValueError("you must set PROBEPREFIX")
return PROBEPREFIX
BINARY = None
def binary():
if BINARY is None:
raise ValueError("you must set BINARY")
return BINARY
def generate_h_begin(events, group):
if group == "root":
header = "trace-dtrace-root.h"
else:
header = "trace-dtrace.h"
# Workaround for ust backend, which also includes <sys/sdt.h> and may
# require SDT_USE_VARIADIC to be defined. If dtrace includes <sys/sdt.h>
# first without defining SDT_USE_VARIADIC then ust breaks because the
# STAP_PROBEV() macro is not defined.
out('#define SDT_USE_VARIADIC 1')
out('#include "%s"' % header,
'')
# SystemTap defines <provider>_<name>_ENABLED() but other DTrace
# implementations might not.
for e in events:
out('#ifndef QEMU_%(uppername)s_ENABLED',
'#define QEMU_%(uppername)s_ENABLED() true',
'#endif',
uppername=e.name.upper())
def generate_h(event, group):
out(' QEMU_%(uppername)s(%(argnames)s);',
uppername=event.name.upper(),
argnames=", ".join(event.args.names()))
def generate_h_backend_dstate(event, group):
out(' QEMU_%(uppername)s_ENABLED() || \\',
uppername=event.name.upper())