Add support to prevent execution

This is essentially a dry-run, and allows to check whether the loads configuration.

Signed-off-by: Stefan Marr <git@stefan-marr.de>

docs/usage.md

@@ -143,6 +143,17 @@ For this purpose we use *schedulers* to determine the execution order.
                         random [default: batch]
 ```
 
+#### Prevent Execution to Verify Configuration
+
+To check whether a configuration is correct, it can be useful to avoid
+execution altogether. For such *testing* or *dry run*, we have the following
+option:
+
+```text
+-E, --no-execution    Disables execution. It allows to verify the
+                      configuration file and other parameters.
+```  
+
 #### Continuous Performance Tracking
 
 ReBench supports [Codespeed][1] as platform for continuous performance

rebench/rebench.py

@@ -116,6 +116,11 @@ def shell_options(self):
             default='batch',
             help='execution order of benchmarks: '
                  'batch, round-robin, random [default: %(default)s]')
+        execution.add_argument(
+            '-E', '--no-execution', action='store_true', dest='no_execution',
+            default=False,
+            help='Disables execution.'
+                 ' It allows to verify the configuration file and other parameters.')
 
         data = parser.add_argument_group(
             'Data and Reporting',
@@ -220,7 +225,11 @@ def execute_experiment(self, runs):
                             self._config.options.debug,
                             scheduler_class,
                             self._config.build_log)
-        return executor.execute()
+
+        if self._config.options.no_execution:
+            return True
+        else:
+            return executor.execute()
 
 
 def main_func():