perf tests c2c: Add function view stdio coverage

Exercise the function view without driving a terminal now that it has
a stdio path. Keep the existing datasym record/report coverage and make a
separate recording of the contended locks used by the futex hash benchmark.

Always check the function table headers, table replacement, missing-iaddr
diagnostic, and conflicting options. A machine can support c2c recording
without capturing a contended sample, so report a skip when the hierarchy
is empty rather than treating hardware sampling variance as a failure.

When samples are available, check generic row shapes for all three
hierarchy levels, their expanded fold signs, cacheline addresses, and the
absence of trailing whitespace in the table body.

Reviewed-by: Tianyou Li <tianyou.li@intel.com>
Reviewed-by: Wangyang Guo <wangyang.guo@intel.com>
Signed-off-by: Jiebin Sun <jiebin.sun@intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/shell/c2c.sh

@@ -6,10 +6,15 @@ set -e
 
 err=0
 perfdata=$(mktemp /tmp/__perf_c2c_test.perf.data.XXXXX)
+funcdata=$(mktemp /tmp/__perf_c2c_function_test.perf.data.XXXXX)
+perfout=$(mktemp /tmp/__perf_c2c_test.output.XXXXX)
 
 cleanup() {
 	rm -f "${perfdata}"
 	rm -f "${perfdata}".old
+	rm -f "${funcdata}"
+	rm -f "${funcdata}".old
+	rm -f "${perfout}"
 	trap - EXIT TERM INT
 }
 
@@ -58,6 +63,114 @@ test_c2c_record_report() {
 	echo "c2c record and report test [Success]"
 }
 
+test_c2c_function_report() {
+	echo "c2c function stdio report test"
+
+	if perf c2c report -i "${perfdata}" --function -c pid > "${perfout}" 2>&1 ; then
+		echo "c2c function stdio report test [Failed: report accepted missing iaddr]"
+		err=1
+		return
+	fi
+	if ! grep -Fq "The function view requires iaddr in --coalesce." "${perfout}" ; then
+		echo "c2c function stdio report test [Failed: missing iaddr diagnostic]"
+		cat "${perfout}"
+		err=1
+		return
+	fi
+	if grep -Fq "Shared Data Functions Table" "${perfout}" ; then
+		echo "c2c function stdio report test [Failed: partial report on missing iaddr]"
+		cat "${perfout}"
+		err=1
+		return
+	fi
+
+	if perf c2c report -i "${perfdata}" --function --stats > "${perfout}" 2>&1 ; then
+		echo "c2c function stdio report test [Failed: accepted conflicting options]"
+		err=1
+		return
+	fi
+	if ! grep -Fq -- "--stats and --function cannot be used together." "${perfout}" ; then
+		echo "c2c function stdio report test [Failed: missing conflict diagnostic]"
+		cat "${perfout}"
+		err=1
+		return
+	fi
+
+	# Exercise contended futex hash-bucket locks so the function view can get
+	# reader, writer, and cacheline rows without changing the original test.
+	if ! perf c2c record -o "${funcdata}" -- \
+		perf bench futex hash -t 4 -r 1 -s > /dev/null 2>&1 ; then
+		echo "c2c function stdio report test [Skipped: recording failed]"
+		err=2
+		return
+	fi
+
+	if ! perf c2c report -i "${funcdata}" --function > "${perfout}" 2>&1 ; then
+		echo "c2c function stdio report test [Failed: report failed]"
+		cat "${perfout}"
+		err=1
+		return
+	fi
+
+	for expected in "Shared Data Functions Table" \
+		"#    Cycles    Store" \
+		"#         %    count  Function / Contending function / Cacheline" \
+		"# .........  ......." ; do
+		if ! grep -Fq "${expected}" "${perfout}" ; then
+			echo "c2c function stdio report test [Failed: missing '${expected}']"
+			cat "${perfout}"
+			err=1
+			return
+		fi
+	done
+	for unexpected in "Shared Data Cache Line Table" \
+		"Shared Cache Line Distribution Pareto" ; do
+		if grep -Fq "${unexpected}" "${perfout}" ; then
+			echo "c2c function stdio report test [Failed: found '${unexpected}']"
+			cat "${perfout}"
+			err=1
+			return
+		fi
+	done
+
+	if ! awk '/^# \.+/ { body = 1; next }
+		body && !/^#/ && NF { found = 1 }
+		END { exit !found }' "${perfout}" ; then
+		echo "c2c function stdio report test [Skipped: no contended samples]"
+		err=2
+		return
+	fi
+
+	# The spaces intentionally verify per-level indentation and expanded
+	# fold-sign placement without depending on symbol names.
+	for expected in \
+		'^  - +[0-9]+\.[0-9]+% +[0-9]+  - ' \
+		'^ +[0-9]+    - ' \
+		'^ +[0-9]+        0x[[:xdigit:]]+$' ; do
+		if ! grep -Eq "${expected}" "${perfout}" ; then
+			echo "c2c function stdio report test [Failed: missing hierarchy row]"
+			echo "  ${expected}"
+			cat "${perfout}"
+			err=1
+			return
+		fi
+	done
+
+	if awk '/^# \.+/ { body = 1; next }
+		body && /[[:blank:]]$/ { found = 1 }
+		END { exit !found }' "${perfout}" ; then
+		echo "c2c function stdio report test [Failed: trailing whitespace in table body]"
+		cat "${perfout}"
+		err=1
+		return
+	fi
+
+	echo "c2c function stdio report test [Success]"
+}
+
 test_c2c_record_report
+if [ "${err}" -eq 0 ]; then
+	test_c2c_function_report
+fi
 cleanup
 exit $err