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SubjectRe: [PATCH 05/12] perf, tools, probe: Print location for resolved variables
On Mon, 27 Nov 2017 16:23:14 -0800
Andi Kleen <andi@firstfloor.org> wrote:

> From: Andi Kleen <ak@linux.intel.com>
>
> Print the location, e.g. the register, for resolved variables
> with perf probe -V. This is useful for debugging, and manually
> making sense of disassembly. I also have some scripts
> which can make use of this information.
>
> Before:
>
> % perf probe -x ./tsrc/tstruct -V main+20
> Available variables at main+20
> @<main+20>
> struct str* xp
>
> After:
>
> % perf probe -x ./tsrc/tstruct -V main+20
> Available variables at main+20
> @<main+20>
> struct str* xp %ax
>

Sounds good :)
For clearly separating it from variable name,
I would like to see as below;

% perf probe -x ./tsrc/tstruct -V main+20
Available variables at main+20
@<main+20>
struct str* xp // %ax


Thank you,

> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
> tools/perf/util/probe-finder.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
> index 0149428d453e..699f29d8a28e 100644
> --- a/tools/perf/util/probe-finder.c
> +++ b/tools/perf/util/probe-finder.c
> @@ -1369,6 +1369,7 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
> if (tag == DW_TAG_formal_parameter ||
> tag == DW_TAG_variable) {
> struct probe_trace_arg ta;
> + struct probe_trace_arg_ref *ref;
>
> memset(&ta, 0, sizeof(struct probe_trace_arg));
> ret = convert_variable_location(die_mem, af->pf.addr,
> @@ -1401,6 +1402,10 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data)
> die_mem, &buf);
> }
>
> + strbuf_addf(&buf, "\t%s", ta.value);
> + for (ref = ta.ref; ref; ref = ref->next)
> + strbuf_addf(&buf, " off %ld", ref->offset);
> +
> pr_debug("Add new var: %s\n", buf.buf);
> if (ret2 == 0) {
> struct str_node *sn;
> --
> 2.13.6
>


--
Masami Hiramatsu <mhiramat@kernel.org>

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