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Date:   Mon,  3 Apr 2023 11:40:29 -0700
Message-Id: <20230403184033.1836023-1-irogers@google.com>
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Subject: [PATCH v2 0/4] Support for llvm-addr2line
From:   Ian Rogers <irogers@google.com>
To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Ian Rogers <irogers@google.com>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        linux-perf-users@vger.kernel.org, llvm@lists.linux.dev
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Precedence: bulk

The addr2line command is started and then addresses piped to it. In
order to determine the end of a addr2lines output a ',' it output with
an expectation to get '??\n??:0\n' as a reply. llvm-addr2line differs
in that ',' generates a reply of ','.

The approach detects and then caches the addr2line style. When records
are read the sentinel is detected appropriately.

Comparing the output there is a little more inline data on my machine
with llvm-addr2line:
$ sudo perf record -a -g sleep 1
$ sudo perf report --addr2line=addr2line > a.txt
$ sudo perf report --addr2line=llvm-addr2line > b.txt
$ wc -l a.txt b.txt
  12386 a.txt
  12477 b.txt

Some other small changes, switching to the api/io code to avoid file
streams wrapping the command's stdin/stdout. Ignore SIGPIPE for when
addr2line exits and writes fail.

v2. Address review comments from Arnaldo and Namhyung, fixing a
    realloc error path, argument ordering and a comment.

Ian Rogers (4):
  tools api: Add io__getline
  perf srcline: Simplify addr2line subprocess
  perf srcline: Support for llvm-addr2line
  perf srcline: Avoid addr2line SIGPIPEs

 tools/lib/api/io.h        |  45 ++++++++++
 tools/perf/tests/api-io.c |  36 ++++++++
 tools/perf/util/srcline.c | 171 +++++++++++++++++++++++---------------
 3 files changed, 184 insertions(+), 68 deletions(-)

-- 
2.40.0.348.gf938b09366-goog