Free the lizard

git-svn-id: svn://10.0.0.236/trunk@10 18797224-902f-48f8-a5cc-f745e15eee43
1998-03-28 02:44:41 +00:00
parent 53f8de8141
commit 8ed5afe62c
5423 changed files with 1772023 additions and 0 deletions
--- a/mozilla/js/jsd/classes/netscape/jsdebug/StackFrameInfo.java
+++ b/mozilla/js/jsd/classes/netscape/jsdebug/StackFrameInfo.java
@@ -0,0 +1,94 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "NPL"); you may not use this file except in
+ * compliance with the NPL.  You may obtain a copy of the NPL at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the NPL is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
+ * for the specific language governing rights and limitations under the
+ * NPL.
+ *
+ * The Initial Developer of this code under the NPL is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
+ * Reserved.
+ */
+
+package netscape.jsdebug;
+
+/**
+* This interface provides access to the execution stack of a thread.
+* It has several subclasses to distinguish between different kinds of
+* stack frames: these currently include activations of Java methods
+* or JavaScript functions.
+* It is possible that synchronize blocks and try blocks deserve their own
+* stack frames - to allow for later extensions a debugger should skip over
+* stack frames it doesn't understand.
+* Note that this appears very Java-specific.  However, multiple threads and
+* exceptions are relevant to JavaScript as well because of its
+* interoperation with Java.
+*
+* @author  John Bandhauer
+* @author  Nick Thompson
+* @version 1.0
+* @since   1.0
+*/
+public abstract class StackFrameInfo {
+    ThreadStateBase threadState;
+    StackFrameInfo caller;
+
+    protected StackFrameInfo(ThreadStateBase threadState) {
+        this.threadState = threadState;
+    }
+
+    /**
+     * Return true if this stack frame is still valid.  Stack frames
+     * may become invalid when the thread is resumed (this is more
+     * conservative than invalidating the frame only when it actually
+     * returns).
+     */
+    public boolean isValid() {
+        return threadState.isValid();
+    }
+
+    /**
+     * Get the stack frame where this one was built, or null for the
+     * start of the stack.
+     */
+    public synchronized StackFrameInfo getCaller()
+        throws InvalidInfoException {
+        if (caller == null)
+            caller = getCaller0();
+        if (!isValid())
+            throw new InvalidInfoException("invalid StackFrameInfo");
+        return caller;
+    }
+
+    protected abstract StackFrameInfo getCaller0()
+        throws InvalidInfoException;
+
+    /**
+     * Get the thread that this stack frame is a part of.
+     */
+    public Thread getThread() {
+        return threadState.getThread();
+    }
+
+    /**
+     * Get the 'enclosing' thread state
+     */
+    public ThreadStateBase getThreadState() {
+        return threadState;
+    }
+
+
+    /**
+     * Get the current program counter value.  Note that the
+     * class JavaPC supports the getMethod() operation.
+     */
+    public abstract PC getPC()
+        throws InvalidInfoException;
+}
+