Re: [PATCH v1 07/11] perf probe: Move elfutils support check to libdw check

[Namhyung Kim <namhyung@kernel.org>]

On Tue, Sep 24, 2024 at 09:04:14AM -0700, Ian Rogers wrote:
> The test _ELFUTILS_PREREQ(0, 142) is false for elfutils before
> 2009-06-13, but that is 15 years ago and very unlikely. Add a test to
> test-libdw.c and assume the libdw version is at least 0.142 to
> simplify the build logic.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/build/feature/test-libdw.c | 10 +++++++++-
>  tools/perf/util/probe-finder.c   |  2 --
>  tools/perf/util/probe-finder.h   |  2 --
>  3 files changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/build/feature/test-libdw.c b/tools/build/feature/test-libdw.c
> index 71c6f8e3b0ee..2fb59479ab77 100644
> --- a/tools/build/feature/test-libdw.c
> +++ b/tools/build/feature/test-libdw.c
> @@ -41,8 +41,16 @@ int test_libdw_getcfi(void)
>  	return dwarf_getcfi(dwarf) == NULL;
>  }
>  
> +int test_elfutils(void)
> +{
> +	Dwarf_CFI *cfi = NULL;
> +
> +	dwarf_cfi_end(cfi);
> +	return 0;
> +}

I think it's the same as test_libdw_getcfi() and let's get rid of it.

Thanks,
Namhyung

> +
>  int main(void)
>  {
>  	return test_libdw() + test_libdw_unwind() + test_libdw_getlocations() +
> -	       test_libdw_getcfi();
> +	       test_libdw_getcfi() + test_elfutils();
>  }
> diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> index 78f34fa0c391..7434b38596b9 100644
> --- a/tools/perf/util/probe-finder.c
> +++ b/tools/perf/util/probe-finder.c
> @@ -1379,10 +1379,8 @@ int debuginfo__find_trace_events(struct debuginfo *dbg,
>  	if (ret >= 0 && tf.pf.skip_empty_arg)
>  		ret = fill_empty_trace_arg(pev, tf.tevs, tf.ntevs);
>  
> -#if _ELFUTILS_PREREQ(0, 142)
>  	dwarf_cfi_end(tf.pf.cfi_eh);
>  	dwarf_cfi_end(tf.pf.cfi_dbg);
> -#endif
>  
>  	if (ret < 0 || tf.ntevs == 0) {
>  		for (i = 0; i < tf.ntevs; i++)
> diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
> index 3add5ff516e1..f0149d72310c 100644
> --- a/tools/perf/util/probe-finder.h
> +++ b/tools/perf/util/probe-finder.h
> @@ -63,12 +63,10 @@ struct probe_finder {
>  	struct intlist		*lcache;	/* Line cache for lazy match */
>  
>  	/* For variable searching */
> -#if _ELFUTILS_PREREQ(0, 142)
>  	/* Call Frame Information from .eh_frame */
>  	Dwarf_CFI		*cfi_eh;
>  	/* Call Frame Information from .debug_frame */
>  	Dwarf_CFI		*cfi_dbg;
> -#endif
>  	Dwarf_Op		*fb_ops;	/* Frame base attribute */
>  	unsigned int		machine;	/* Target machine arch */
>  	struct perf_probe_arg	*pvar;		/* Current target variable */
> -- 
> 2.46.0.792.g87dc391469-goog
>