Add a simple test for sandbox trace

It is difficult to automatically test tracing on most architectures, but
with sandbox it is easy enough to do a simple sanity check.

Signed-off-by: Simon Glass <sjg@chromium.org>

test/trace/test-trace.sh

@@ -0,0 +1,89 @@
+# Copyright (c) 2013 The Chromium OS Authors.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+# Simple test script for tracing with sandbox
+
+OUTPUT_DIR=sandbox
+TRACE_OPT="FTRACE=1"
+
+fail() {
+	echo "Test failed: $1"
+	if [ -n ${tmp} ]; then
+		rm ${tmp}
+	fi
+	exit 1
+}
+
+build_uboot() {
+	echo "Build sandbox"
+	OPTS="O=${OUTPUT_DIR} ${TRACE_OPT}"
+	NUM_CPUS=$(grep -c processor /proc/cpuinfo)
+	make ${OPTS} sandbox_config
+	make ${OPTS} -s -j${NUM_CPUS}
+}
+
+run_trace() {
+	echo "Run trace"
+	./${OUTPUT_DIR}/u-boot <<END
+	trace stats
+	hash sha256 0 10000
+	trace pause
+	trace stats
+	hash sha256 0 10000
+	trace stats
+	trace resume
+	hash sha256 0 10000
+	trace pause
+	trace stats
+	reset
+END
+}
+
+check_results() {
+	echo "Check results"
+
+	# Expect sha256 to run 3 times, so we see the string 6 times
+	if [ $(grep -c sha256 ${tmp}) -ne 6 ]; then
+		fail "sha256 error"
+	fi
+
+	# 4 sets of results (output of 'trace stats')
+	if [ $(grep -c "traced function calls" ${tmp}) -ne 4 ]; then
+		fail "trace output error"
+	fi
+
+	# Check trace counts. We expect to see an increase in the number of
+	# traced function calls between each 'trace stats' command, except
+	# between calls 2 and 3, where tracing is paused.
+	# This code gets the sign of the difference between each number and
+	# its predecessor.
+	counts="$(tr -d , <${tmp} | awk '/traced function calls/ { diff = $1 - upto; upto = $1; printf "%d ", diff < 0 ? -1 : (diff > 0 ? 1 : 0)}')"
+
+	if [ "${counts}" != "1 1 0 1 " ]; then
+		fail "trace collection error: ${counts}"
+	fi
+}
+
+echo "Simple trace test / sanity check using sandbox"
+echo
+tmp="$(tempfile)"
+build_uboot
+run_trace >${tmp}
+check_results ${tmp}
+rm ${tmp}
+echo "Test passed"