Every generated inline probe function is wrapped with a
trivial caller that has a hard-coded condition test:
static inline void _nocheck__trace_test_wibble(void * context, int value)
{
tracepoint(qemu, test_wibble, context, value);
}
static inline void trace_test_wibble(void * context, int value)
{
if (true) {
_nocheck__trace_test_wibble(context, value);
}
}
This was introduced for TCG probes back in
864a2178: trace: [tcg] Do not generate TCG code to trace dynamically-disabled events
but is obsolete since
126d4123 tracing: excise the tcg related from tracetool
This commit removes the wrapping such that we have
static inline void trace_test_wibble(void * context, int value)
{
tracepoint(qemu, test_wibble, context, value);
}
The default build of qemu-system-x86_64 on Fedora with the
'log' backend, has its size reduced by 1 MB
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20250916081638.764020-7-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
When reviewing tracetool patches it is often very unclear what the
expected output will be for the generated backends. Compounding
this is that a default build will only enable the 'log' trace
backend, so developers won't see generated code for other backends
without making a special effort. Some backends are also platform
specific, so can't be enabled in QEMU builds, even though tracetool
could generate the code.
To address this, introduce a test suite for tracetool which is
conceptually similar to the qapi-schema test. It is a simple
python program that runs tracetool and compares the actual output
to historical reference output kept in git. The test directly
emits TAP format logs for ease of integration with meson.
This can be run with
make check-tracetool
to make it easier for developers changing generated output, the
sample expected content can be auto-recreated
QEMU_TEST_REGENERATE=1 make check-tracetool
and the changes reviewed and added to the commit. This will also
assist reviewers interpreting the change.
Developers are reminded of this in the test output on failure:
$ make check-tracetool
1/6 qemu:tracetool / dtrace OK 0.14s
2/6 qemu:tracetool / ftrace FAIL 0.06s exit status 1
――――――――――――――――――――――――――――――――――――――――――――――――――――――――――
1..2
ok 1 - ftrace.c
#
not ok 1 - ftrace.h (set QEMU_TEST_REGENERATE=1 to recreate reference output if tracetool generator was intentionally changed)
――――――――――――――――――――――――――――――――――――――――――――――――――――――――――
3/6 qemu:tracetool / log OK 0.06s
4/6 qemu:tracetool / simple OK 0.06s
5/6 qemu:tracetool / syslog OK 0.06s
6/6 qemu:tracetool / ust OK 0.11s
Summary of Failures:
2/6 qemu:tracetool / ftrace FAIL 0.06s exit status 1
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20250916081638.764020-6-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
