tests: check for gem5 binary before tests

Provides a helpful error when tests.py is invoked without the gem5 binary.

Before:
Running 0 tests

After:
gem5 binary 'quick/...' not an executable file

Change-Id: I1566802206c9e21ca89bd03e91db22844168a085
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/tests/tests.py b/tests/tests.py
index 136c879aa..3f6ed0a7a 100755
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -174,6 +174,11 @@ def _run_tests_args(subparsers):
     _add_format_args(parser)
 
 def _run_tests(args):
+    if not os.path.isfile(args.gem5) or not os.access(args.gem5, os.X_OK):
+        print >> sys.stderr, \
+            "gem5 binary '%s' not an executable file" % args.gem5
+        sys.exit(2)
+
     formatter = _create_formatter(args)
 
     out_base = os.path.abspath(args.directory)