Improved stack overflow stack printing, fixes #709

core/interpreter/src/main/java/org/overture/interpreter/runtime/Context.java

@@ -24,6 +24,8 @@
 package org.overture.interpreter.runtime;
 
 import java.io.PrintWriter;
+import java.util.LinkedList;
+import java.util.List;
 
 import org.overture.ast.intf.lex.ILexLocation;
 import org.overture.ast.intf.lex.ILexNameToken;
@@ -336,32 +338,52 @@ protected String format(String indent, Context what)
 	}
 
 	/**
-	 * This is used by the stack overflow processing in Function/OperationValue.
-	 * It is intended to print the frame titles without recursing.
-	 * @param out
+	 * This is used by the stack overflow processing via Function/OperationValue.
+	 * It is intended to print the frame titles without recursing, and to
+	 * suppress all but the top and bottom of the (presumably large) stack.
 	 */
-
-	private static final int FRAMES_LIMIT = 50;
+	private static final int FRAMES_LIMIT	= 50;	// Top count
+	private static final int TAIL_LIMIT		= 5;	// Bottom count
 
 	public void printStackFrames(PrintWriter out)
 	{
 		Context frame = this;
 		out.print(format("\t", frame));
 		int count = 0;
+		List<String> saved = new LinkedList<String>();
 
 		while (frame.outer != null)
 		{
 			if (++count < FRAMES_LIMIT)
 			{
 				out.println("In context of " + frame.title + " " + frame.location);
 			}
-			else if (count == FRAMES_LIMIT)
+			else
 			{
-				out.println("...");
+				saved.add(String.format("In context of " + frame.title + " " + frame.location));
 			}
 
 			frame = frame.outer;	// NB. DON'T RECURSE!
 		}
+
+		int skipped = saved.size();
+
+		if (skipped < TAIL_LIMIT)
+		{
+			for (String s: saved)
+			{
+				out.println(s);
+			}
+		}
+		else
+		{
+			out.println("... skipped " + (skipped - TAIL_LIMIT));
+
+			for (int i = skipped - TAIL_LIMIT; i < skipped; i++)
+			{
+				out.println(saved.get(i));
+			}
+		}
 
 		out.println("In context of " + frame.title);
 	}