configuration/core: Add programmatic labels

A label may include ``{<param_name>}`` where <param_name> is any valid
workload, boot or runtime parameter that the workload may take. The
generated job will then substitute in the value of that parameter that
was taken.

More than one parameter may be identified (within separate sets of
``{}``) within a single label, and these may be alongside normal text
similar to python replacement fields.

wa/framework/configuration/core.py

@@ -997,6 +997,33 @@ class JobSpec(Configuration):
         if self.label is None:
             self.label = self.workload_name
 
+        self.convert_auto_label()
+
+    def convert_auto_label(self):
+        to_fetch = set() # Total parameter names required
+        for _, name, _, _ in Formatter().parse(str(self.label)):
+            if name:
+                to_fetch.add(name)
+
+        if not to_fetch:
+            return
+
+        fetched = {}  # maps parameter name -> value
+        for k, v in self.workload_parameters.items():
+            if k in to_fetch:
+                fetched[k] = v
+        for k, v in self.runtime_parameters.items():
+            if k in to_fetch:
+                fetched[k] = v
+        for k, v in self.boot_parameters.items():
+            if k in to_fetch:
+                fetched[k] = v
+
+        try:
+            self.label = self.label.format(**fetched)
+        except KeyError as e:
+                msg = '{} is not a recognised parameter'
+                raise ConfigError(msg.format(e.args[0]))
 
 # This is used to construct the list of Jobs WA will run
 class JobGenerator(object):