From 7fb48c0ee1bbf5cc4c905e900b054096250e9f39 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 27 Aug 2020 15:29:15 +0100 Subject: [PATCH] tracetool: show trace-events filename/lineno in fmt string errors MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Stefan Hajnoczi Reviewed-by: Peter Maydell Message-Id: <20200827142915.108730-5-stefanha@redhat.com> --- scripts/tracetool/backend/ftrace.py | 4 ++++ scripts/tracetool/backend/log.py | 4 ++++ scripts/tracetool/backend/syslog.py | 4 ++++ 3 files changed, 12 insertions(+) diff --git a/scripts/tracetool/backend/ftrace.py b/scripts/tracetool/backend/ftrace.py index e9844dd335..5fa30ccc08 100644 --- a/scripts/tracetool/backend/ftrace.py +++ b/scripts/tracetool/backend/ftrace.py @@ -33,8 +33,10 @@ def generate_h(event, group): ' 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);', ' }', @@ -42,6 +44,8 @@ def generate_h(event, group): 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) diff --git a/scripts/tracetool/backend/log.py b/scripts/tracetool/backend/log.py index 877222bbe9..bc43dbb4f4 100644 --- a/scripts/tracetool/backend/log.py +++ b/scripts/tracetool/backend/log.py @@ -37,12 +37,16 @@ def generate_h(event, group): out(' if (%(cond)s && qemu_loglevel_mask(LOG_TRACE)) {', ' struct timeval _now;', ' gettimeofday(&_now, NULL);', + '#line %(event_lineno)d "%(event_filename)s"', ' qemu_log("%%d@%%zu.%%06zu:%(name)s " %(fmt)s "\\n",', ' qemu_get_thread_id(),', ' (size_t)_now.tv_sec, (size_t)_now.tv_usec', ' %(argnames)s);', + '#line %(out_next_lineno)d "%(out_filename)s"', ' }', cond=cond, + event_lineno=event.lineno, + event_filename=event.filename, name=event.name, fmt=event.fmt.rstrip("\n"), argnames=argnames) diff --git a/scripts/tracetool/backend/syslog.py b/scripts/tracetool/backend/syslog.py index 1373a90192..5a3a00fe31 100644 --- a/scripts/tracetool/backend/syslog.py +++ b/scripts/tracetool/backend/syslog.py @@ -35,9 +35,13 @@ def generate_h(event, group): cond = "trace_event_get_state(%s)" % ("TRACE_" + event.name.upper()) out(' if (%(cond)s) {', + '#line %(event_lineno)d "%(event_filename)s"', ' syslog(LOG_INFO, "%(name)s " %(fmt)s %(argnames)s);', + '#line %(out_next_lineno)d "%(out_filename)s"', ' }', cond=cond, + event_lineno=event.lineno, + event_filename=event.filename, name=event.name, fmt=event.fmt.rstrip("\n"), argnames=argnames)