Added stack overflow handing, fixes #709

overturetool · Nov 29, 2019 · c29570c · c29570c
1 parent 98065ea
commit c29570c
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Showing 3 changed files with 105 additions and 12 deletions.
diff --git a/core/interpreter/src/main/java/org/overture/interpreter/runtime/Context.java b/core/interpreter/src/main/java/org/overture/interpreter/runtime/Context.java
@@ -335,6 +335,37 @@ protected String format(String indent, Context what)
 		return sb.toString();
 	}
 
+	/**
+	 * This is used by the stack overflow processing in Function/OperationValue.
+	 * It is intended to print the frame titles without recursing.
+	 * @param out
+	 */
+
+	private static final int FRAMES_LIMIT = 100;
+
+	public void printStackFrames(PrintWriter out)
+	{
+		Context frame = this;
+		out.print(format("\t", frame));
+		int count = 0;
+
+		while (frame.outer != null)
+		{
+			if (++count < FRAMES_LIMIT)
+			{
+				out.println("In context of " + frame.title + " " + frame.location);
+			}
+			else if (count == FRAMES_LIMIT)
+			{
+				out.println("...");
+			}
+
+			frame = frame.outer;	// NB. DON'T RECURSE!
+		}
+
+		out.println("In context of " + frame.title);
+	}
+
 	public void printStackTrace(PrintWriter out, boolean variables)
 	{
 		if (outer == null) // Don't expand initial context

diff --git a/core/interpreter/src/main/java/org/overture/interpreter/values/FunctionValue.java b/core/interpreter/src/main/java/org/overture/interpreter/values/FunctionValue.java
@@ -270,17 +270,50 @@ public String toString()
 		return type.toString();
 	}
 
+	private static Integer stackUnwind		= null;
+	private static final int UNWIND_COUNT	= 20;	// Needed by printStackFrames
+
+	private ContextException stackOverflow(StackOverflowError e, Context ctxt)
+	{
+		if (stackUnwind == null)	// First time
+		{
+			stackUnwind = new Integer(UNWIND_COUNT);
+		}
+		else if (--stackUnwind <= 0)
+		{
+			Console.out.printf("Stack overflow %s\n", location);
+			ctxt.printStackFrames(Console.out);
+			return new ContextException(4174, "Stack overflow", location, ctxt);
+		}
+
+		throw e;	// Unwind further to make space for printStackFrames
+	}
+
 	public Value eval(ILexLocation from, Value arg, Context ctxt)
 			throws AnalysisException
 	{
-		ValueList args = new ValueList(arg);
-		return eval(from, args, ctxt, null);
+		try
+		{
+			ValueList args = new ValueList(arg);
+			return eval(from, args, ctxt, null);
+		}
+		catch (StackOverflowError e)
+		{
+			throw stackOverflow(e, ctxt);
+		}
 	}
 
 	public Value eval(ILexLocation from, ValueList argValues, Context ctxt)
 			throws AnalysisException
 	{
-		return eval(from, argValues, ctxt, null);
+		try
+		{
+			return eval(from, argValues, ctxt, null);
+		}
+		catch (StackOverflowError e)
+		{
+			throw stackOverflow(e, ctxt);
+		}
 	}
 
 	public void setSelf(ObjectValue self)
@@ -304,6 +337,8 @@ public void setClass(SClassDefinition classdef)
 	public Value eval(ILexLocation from, ValueList argValues, Context ctxt,
 			Context sctxt) throws AnalysisException
 	{
+		stackUnwind = null;
+
 		if (uninstantiated)
 		{
 			abort(3033, "Polymorphic function has not been instantiated: "

diff --git a/core/interpreter/src/main/java/org/overture/interpreter/values/OperationValue.java b/core/interpreter/src/main/java/org/overture/interpreter/values/OperationValue.java
@@ -67,6 +67,7 @@
 import org.overture.interpreter.runtime.ClassContext;
 import org.overture.interpreter.runtime.ClassInterpreter;
 import org.overture.interpreter.runtime.Context;
+import org.overture.interpreter.runtime.ContextException;
 import org.overture.interpreter.runtime.Interpreter;
 import org.overture.interpreter.runtime.ModuleInterpreter;
 import org.overture.interpreter.runtime.ObjectContext;
@@ -254,25 +255,51 @@ public void prepareGuard(ObjectContext ctxt)
 		}
 	}
 
+	private static Integer stackUnwind		= null;
+	private static final int UNWIND_COUNT	= 20;	// Needed by printStackFrames
+
+	private ContextException stackOverflow(ILexLocation location, StackOverflowError e, Context ctxt)
+	{
+		if (stackUnwind == null)	// First time
+		{
+			stackUnwind = new Integer(UNWIND_COUNT);
+		}
+		else if (--stackUnwind <= 0)
+		{
+			Console.out.printf("Stack overflow %s\n", location);
+			ctxt.printStackFrames(Console.out);
+			return new ContextException(4174, "Stack overflow", location, ctxt);
+		}
+
+		throw e;	// Unwind further to make space for printStackFrames
+	}
+
 	public Value eval(ILexLocation from, ValueList argValues, Context ctxt)
 			throws AnalysisException
 	{
-		// Note args cannot be Updateable, so we convert them here. This means
-		// that TransactionValues pass the local "new" value to the far end.
-		ValueList constValues = argValues.getConstant();
-
-		if (Settings.dialect == Dialect.VDM_RT)
+		try
 		{
-			if (!isStatic && (ctxt.threadState.CPU != self.getCPU() || isAsync))
+			// Note args cannot be Updateable, so we convert them here. This means
+			// that TransactionValues pass the local "new" value to the far end.
+			ValueList constValues = argValues.getConstant();
+
+			if (Settings.dialect == Dialect.VDM_RT)
 			{
-				return asyncEval(constValues, ctxt);
+				if (!isStatic && (ctxt.threadState.CPU != self.getCPU() || isAsync))
+				{
+					return asyncEval(constValues, ctxt);
+				} else
+				{
+					return localEval(from, constValues, ctxt, true);
+				}
 			} else
 			{
 				return localEval(from, constValues, ctxt, true);
 			}
-		} else
+		}
+		catch (StackOverflowError e)
 		{
-			return localEval(from, constValues, ctxt, true);
+			throw stackOverflow(from, e, ctxt);
 		}
 	}