qemu-e2k/scripts/tracetool/backend/ftrace.py
Stefan Hajnoczi 7fb48c0ee1 tracetool: show trace-events filename/lineno in fmt string errors
The compiler encounters trace event format strings in generated code.
Format strings are error-prone and therefore clear compiler errors are
important.

Use the #line directive to show the trace-events filename and line
number in format string errors:
https://gcc.gnu.org/onlinedocs/gcc-10.2.0/cpp/Line-Control.html

For example, if the cpu_in trace event's %u is changed to %p the
following error is reported:

  trace-events:29:18: error: format ‘%p’ expects argument of type ‘void *’, but argument 7 has type ‘unsigned int’ [-Werror=format=]

Line 29 in trace-events is where cpu_in is defined. This works for any
trace-events file in the QEMU source tree and the correct path is
displayed.

Unfortunately there does not seem to be a way to set the column, so "18"
is not the right character on that line.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200827142915.108730-5-stefanha@redhat.com>
2021-01-04 14:24:58 +00:00

56 lines
1.6 KiB
Python

# -*- coding: utf-8 -*-
"""
Ftrace built-in backend.
"""
__author__ = "Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>"
__copyright__ = "Copyright (C) 2013 Hitachi, Ltd."
__license__ = "GPL version 2 or (at your option) any later version"
__maintainer__ = "Stefan Hajnoczi"
__email__ = "stefanha@redhat.com"
from tracetool import out
PUBLIC = True
def generate_h_begin(events, group):
out('#include "trace/ftrace.h"',
'')
def generate_h(event, group):
argnames = ", ".join(event.args.names())
if len(event.args) > 0:
argnames = ", " + argnames
out(' {',
' char ftrace_buf[MAX_TRACE_STRLEN];',
' int unused __attribute__ ((unused));',
' int trlen;',
' if (trace_event_get_state(%(event_id)s)) {',
'#line %(event_lineno)d "%(event_filename)s"',
' trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
' "%(name)s " %(fmt)s "\\n" %(argnames)s);',
'#line %(out_next_lineno)d "%(out_filename)s"',
' trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
' unused = write(trace_marker_fd, ftrace_buf, trlen);',
' }',
' }',
name=event.name,
args=event.args,
event_id="TRACE_" + event.name.upper(),
event_lineno=event.lineno,
event_filename=event.filename,
fmt=event.fmt.rstrip("\n"),
argnames=argnames)
def generate_h_backend_dstate(event, group):
out(' trace_event_get_state_dynamic_by_id(%(event_id)s) || \\',
event_id="TRACE_" + event.name.upper())