qemu/scripts/tracetool/backend/dtrace.py
Stefan Hajnoczi 000822441e tracetool: carefully define SDT_USE_VARIADIC
The dtrace backend defines SDT_USE_VARIADIC as a workaround for a
conflict with a LTTng UST header file, which requires SDT_USE_VARIADIC
to be defined.

LTTng UST <lttng/tracepoint.h> breaks if included after generated dtrace
headers because SDT_USE_VARIADIC will already be defined:

  #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
  #define SDT_USE_VARIADIC <-- error, it's already defined
  #include <sys/sdt.h>

Be more careful when defining SDT_USE_VARIADIC. This fixes the build
when both the dtrace and ust tracers are enabled at the same time.

Fixes: 27e08bab94 ("tracetool: work around ust <sys/sdt.h> include conflict")
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200729153926.127083-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-07-30 16:02:38 +01:00

72 lines
1.8 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('#ifndef SDT_USE_VARIADIC')
out('#define SDT_USE_VARIADIC 1')
out('#endif')
out('#include "%s"' % header,
'')
out('#undef SDT_USE_VARIADIC')
# 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())