[PATCH v1 1/4] perf expr: Allow NaN to be a valid number

From: Ian Rogers
Date: Fri Feb 09 2024 - 15:50:31 EST


Currently only floating point numbers can be parsed, add a special
case for NaN.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/util/expr.l | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/tools/perf/util/expr.l b/tools/perf/util/expr.l
index 0feef0726c48..a2fc43159ee9 100644
--- a/tools/perf/util/expr.l
+++ b/tools/perf/util/expr.l
@@ -94,6 +94,14 @@ static int literal(yyscan_t scanner, const struct expr_scanner_ctx *sctx)
}
return LITERAL;
}
+
+static int nan_value(yyscan_t scanner)
+{
+ YYSTYPE *yylval = expr_get_lval(scanner);
+
+ yylval->num = NAN;
+ return NUMBER;
+}
%}

number ([0-9]+\.?[0-9]*|[0-9]*\.?[0-9]+)(e-?[0-9]+)?
@@ -115,6 +123,7 @@ else { return ELSE; }
source_count { return SOURCE_COUNT; }
has_event { return HAS_EVENT; }
strcmp_cpuid_str { return STRCMP_CPUID_STR; }
+NaN { return nan_value(yyscanner); }
{literal} { return literal(yyscanner, sctx); }
{number} { return value(yyscanner); }
{symbol} { return str(yyscanner, ID, sctx->runtime); }
--
2.43.0.687.g38aa6559b0-goog