From: Brian Norris <banorris@uci.edu>
Date: Sat, 2 Mar 2013 00:45:52 +0000 (-0800)
Subject: action: bugfix - reads-from value should be VALUE_NONE for new actions
X-Git-Tag: oopsla2013~189
X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=commitdiff_plain;h=68b6b3ecad7edcaed6547d4d2be3eb974dfc98d6

action: bugfix - reads-from value should be VALUE_NONE for new actions

If a new read action hasn't had a chance to choose a valid reads-from or
reads-from-promise, it can have "no" value. This only occurs if we are
terminating an infeasible execution, where there were no valid reads to
read from.

This bug was triggering faults only for verbose printing, were we would
print the status of an incomplete read.
---

diff --git a/action.cc b/action.cc
index 5f83c3f..757b3d1 100644
--- a/action.cc
+++ b/action.cc
@@ -394,7 +394,9 @@ uint64_t ModelAction::get_reads_from_value() const
 	ASSERT(is_read());
 	if (reads_from)
 		return reads_from->get_write_value();
-	return reads_from_promise->get_value();
+	else if (reads_from_promise)
+		return reads_from_promise->get_value();
+	return VALUE_NONE; /* Only for new actions with no reads-from */
 }
 
 /**