[PATCH v3 3/7] selftests/ftrace: Add "requires:" list support

[Masami Hiramatsu <mhiramat@xxxxxxxxxx>]

Introduce "requires:" list to check required ftrace interface
for each test. This will simplify the interface checking code
and unify the error message. Another good point is, it can
skip the ftrace initializing.

Note that this requires list must be written as a shell
comment.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Reviewed-by: Tom Zanussi <zanussi@xxxxxxxxxx>
---
 Changes in v3:
  - Fixes a comment in template file.
---
 tools/testing/selftests/ftrace/ftracetest       |    8 +++++++-
 tools/testing/selftests/ftrace/test.d/functions |    9 +++++++++
 tools/testing/selftests/ftrace/test.d/template  |    1 +
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/ftrace/ftracetest b/tools/testing/selftests/ftrace/ftracetest
index d3f6652311ef..cdf7940b6610 100755
--- a/tools/testing/selftests/ftrace/ftracetest
+++ b/tools/testing/selftests/ftrace/ftracetest
@@ -267,6 +267,11 @@ testcase() { # testfile
   prlog -n "[$CASENO]$INSTANCE$desc"
 }
 
+checkreq() { # testfile
+  requires=`grep "^#[ \t]*requires:" $1 | cut -f2- -d:`
+  check_requires $requires
+}
+
 test_on_instance() { # testfile
   grep -q "^#[ \t]*flags:.*instance" $1
 }
@@ -356,7 +361,8 @@ trap 'SIG_RESULT=$XFAIL' $SIG_XFAIL
 
 __run_test() { # testfile
   # setup PID and PPID, $$ is not updated.
-  (cd $TRACING_DIR; read PID _ < /proc/self/stat; set -e; set -x; initialize_ftrace; . $1)
+  (cd $TRACING_DIR; read PID _ < /proc/self/stat; set -e; set -x;
+   checkreq $1; initialize_ftrace; . $1)
   [ $? -ne 0 ] && kill -s $SIG_FAIL $SIG_PID
 }
 
diff --git a/tools/testing/selftests/ftrace/test.d/functions b/tools/testing/selftests/ftrace/test.d/functions
index 697c77ef2e2b..5100eb1ada0f 100644
--- a/tools/testing/selftests/ftrace/test.d/functions
+++ b/tools/testing/selftests/ftrace/test.d/functions
@@ -113,6 +113,15 @@ initialize_ftrace() { # Reset ftrace to initial-state
     enable_tracing
 }
 
+check_requires() { # Check required files
+    for i in $* ; do
+        if [ ! -e $i ]; then
+            echo "Required feature interface $i doesn't exist."
+            exit_unsupported
+        fi
+    done
+}
+
 LOCALHOST=127.0.0.1
 
 yield() {
diff --git a/tools/testing/selftests/ftrace/test.d/template b/tools/testing/selftests/ftrace/test.d/template
index e1a5d14c4eaf..611423c4e75f 100644
--- a/tools/testing/selftests/ftrace/test.d/template
+++ b/tools/testing/selftests/ftrace/test.d/template
@@ -1,6 +1,7 @@
 #!/bin/sh
 # SPDX-License-Identifier: GPL-2.0
 # description: %HERE DESCRIBE WHAT THIS DOES%
+# requires: %HERE LIST THE REQUIRED FILES%
 # you have to add ".tc" extention for your testcase file
 # Note that all tests are run with "errexit" option.