Re: [PATCH v2 05/12] perf jevents: Support parsing negative exponents

[Namhyung Kim]

On Fri, Mar 1, 2024 at 5:00 PM Ian Rogers <irogers@xxxxxxxxxx> wrote:
>
> Support negative exponents when parsing from a json metric string by
> making the numbers after the 'e' optional in the 'Event' insertion fix
> up.
>
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
>  tools/perf/pmu-events/metric.py      | 2 +-
>  tools/perf/pmu-events/metric_test.py | 4 ++++
>  2 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/pmu-events/metric.py b/tools/perf/pmu-events/metric.py
> index 847b614d40d5..31eea2f45152 100644
> --- a/tools/perf/pmu-events/metric.py
> +++ b/tools/perf/pmu-events/metric.py
> @@ -573,7 +573,7 @@ def ParsePerfJson(orig: str) -> Expression:
>    # a double by the Bison parser
>    py = re.sub(r'0Event\(r"[xX]([0-9a-fA-F]*)"\)', r'Event("0x\1")', py)
>    # Convert accidentally converted scientific notation constants back
> -  py = re.sub(r'([0-9]+)Event\(r"(e[0-9]+)"\)', r'\1\2', py)
> +  py = re.sub(r'([0-9]+)Event\(r"(e[0-9]*)"\)', r'\1\2', py)

I don't understand how it can handle negative numbers.
Why isn't it like Event\(r"(e-?[0-9]+)"\) ?

Thanks,
Namhyung


>    # Convert all the known keywords back from events to just the keyword
>    keywords = ['if', 'else', 'min', 'max', 'd_ratio', 'source_count', 'has_event', 'strcmp_cpuid_str']
>    for kw in keywords:
> diff --git a/tools/perf/pmu-events/metric_test.py b/tools/perf/pmu-events/metric_test.py
> index ee22ff43ddd7..8acfe4652b55 100755
> --- a/tools/perf/pmu-events/metric_test.py
> +++ b/tools/perf/pmu-events/metric_test.py
> @@ -61,6 +61,10 @@ class TestMetricExpressions(unittest.TestCase):
>      after = before
>      self.assertEqual(ParsePerfJson(before).ToPerfJson(), after)
>
> +    before = r'a + 3e-12 + b'
> +    after = before
> +    self.assertEqual(ParsePerfJson(before).ToPerfJson(), after)
> +
>    def test_IfElseTests(self):
>      # if-else needs rewriting to Select and back.
>      before = r'Event1 if #smt_on else Event2'
> --
> 2.44.0.278.ge034bb2e1d-goog
>