Re: [RFC 0/6] perf probe: Attempt to improve C++ probing
From: Masami Hiramatsu
Date: Mon May 14 2018 - 09:08:54 EST
Thank you for your great work!
On Mon, 14 May 2018 12:19:34 +0800
Holger Freyther <automatic+kernel@xxxxxxxxxxx> wrote:
> From: Holger Hans Peter Freyther <holgar+kernel@xxxxxxxxxx>
> Currently perf probe -x app --funcs will list and demangle C++ functions
> but the other probe actions can't work with them. When asking probe to not
> demangle it will not list any of the application symbols creating the
> impression that there are no symbols at all.
> Make --funcs --no-demangle list all C++ functions and modify the handling
> for listing code, variables and adding the uprobe work with the demangled
> C++ function name.
> I tried to keep this as minimal as possible but having to keep the dso in
> the debuginfo and passing it everywhere to be able to demangle the linkage
> name isn't pretty (and for C++ demangling the struct dso is not of much
> use. Maybe having a static "empty" dso could avoid a lot of the changes).
> Maybe the easiest first patch is to default to --no-demangle and change
> the DEFAULT_FUNC_FILTER to not include mangled C++ symbols. The remaining
> tooling would work then.
> This has seen very little testing outside the following commands.
> My test set includes:
> ./perf probe -x . -L "std::vector<int, std::allocator<int> >::at"
> ./perf probe -x . -L "std::vector<int, std::allocator<int> >::at:2-3"
> ./perf probe -x . -V "std::vector<int, std::allocator<int> >::at"
> ./perf probe -x . -V "std::vector<int, std::allocator<int> >::at:2"
> ./perf probe -x . -V "std::vector<int, std::allocator<int> >::size%return"
OK, let me review it.
> Holger Hans Peter Freyther (6):
> perf probe: Do not exclude mangled C++ funcs
> perf probe: Parse linerange for C++ functions
> perf probe: Make listing of C++ functions work
> perf probe: Show variables for C++ functions
> perf probe: Make listing of variables work for C++ functions
> perf probe: Make it possible to add a C++ uprobe
> tools/perf/builtin-probe.c | 2 +-
> tools/perf/util/probe-event.c | 77 ++++++++++++++++++++-
> tools/perf/util/probe-finder.c | 152 ++++++++++++++++++++++++++++++-----------
> tools/perf/util/probe-finder.h | 3 +
> tools/perf/util/string.c | 57 ++++++++++++++++
> tools/perf/util/string2.h | 1 +
> 6 files changed, 247 insertions(+), 45 deletions(-)
Masami Hiramatsu <mhiramat@xxxxxxxxxx>