dim.java

javascript语言的解释器源码

        for (int i = 0; i != function.getFunctionCount(); ++i) {
            collectFunctions_r(function.getFunction(i), array);
        }
    }

    void clearAllBreakpoints()
    {
        Enumeration e = urlToSourceInfo.elements();
        while (e.hasMoreElements()) {
            SourceInfo si = (SourceInfo)e.nextElement();
            si.removeAllBreakpoints();
        }
    }

    void handleBreakpointHit(StackFrame frame, Context cx) {
        breakFlag = false;
        interrupted(cx, frame, null);
    }

    void handleExceptionThrown(Context cx, Throwable ex, StackFrame frame) {
        if (breakOnExceptions) {
            ContextData cd = frame.contextData();
            if (cd.lastProcessedException != ex) {
                interrupted(cx, frame, ex);
                cd.lastProcessedException = ex;
            }
        }
    }

    /* end Debugger interface */

    void contextSwitch (int frameIndex) {
        this.frameIndex = frameIndex;
    }

    ContextData currentContextData() {
        return interruptedContextData;
    }

    void setReturnValue(int returnValue)
    {
        synchronized (monitor) {
            this.returnValue = returnValue;
            monitor.notify();
        }
    }

    void go()
    {
        synchronized (monitor) {
            this.returnValue = GO;
            monitor.notifyAll();
        }
    }

    String eval(String expr)
    {
        String result = "undefined";
        if (expr == null) {
            return result;
        }
        ContextData contextData = currentContextData();
        if (contextData == null || frameIndex >= contextData.frameCount()) {
            return result;
        }
        StackFrame frame = contextData.getFrame(frameIndex);
        if (contextData.eventThreadFlag) {
            Context cx = Context.getCurrentContext();
            result = do_eval(cx, frame, expr);
        } else {
            synchronized (monitor) {
                if (insideInterruptLoop) {
                    evalRequest = expr;
                    evalFrame = frame;
                    monitor.notify();
                    do {
                        try {
                            monitor.wait();
                        } catch (InterruptedException exc) {
                            Thread.currentThread().interrupt();
                            break;
                        }
                    } while (evalRequest != null);
                    result = evalResult;
                }
            }
        }
        return result;
    }

    void compileScript(String url, String text)
    {
        DimIProxy action = new DimIProxy(this, IPROXY_COMPILE_SCRIPT);
        action.url = url;
        action.text = text;
        action.withContext();
    }

    void evalScript(final String url, final String text)
    {
        DimIProxy action = new DimIProxy(this, IPROXY_EVAL_SCRIPT);
        action.url = url;
        action.text = text;
        action.withContext();
    }

    String objectToString(Object object)
    {
        DimIProxy action = new DimIProxy(this, IPROXY_OBJECT_TO_STRING);
        action.object = object;
        action.withContext();
        return action.stringResult;
    }

    boolean stringIsCompilableUnit(String str)
    {
        DimIProxy action = new DimIProxy(this, IPROXY_STRING_IS_COMPILABLE);
        action.text = str;
        action.withContext();
        return action.booleanResult;
    }

    Object getObjectProperty(Object object, Object id)
    {
        DimIProxy action = new DimIProxy(this, IPROXY_OBJECT_PROPERTY);
        action.object = object;
        action.id = id;
        action.withContext();
        return action.objectResult;
    }

    Object[] getObjectIds(Object object)
    {
        DimIProxy action = new DimIProxy(this, IPROXY_OBJECT_IDS);
        action.object = object;
        action.withContext();
        return action.objectArrayResult;
    }

    Object getObjectPropertyImpl(Context cx, Object object, Object id)
    {
        Scriptable scriptable = (Scriptable)object;
        Object result;
        if (id instanceof String) {
            String name = (String)id;
            if (name.equals("this")) {
                result = scriptable;
            } else if (name.equals("__proto__")) {
                result = scriptable.getPrototype();
            } else if (name.equals("__parent__")) {
                result = scriptable.getParentScope();
            } else {
                result = ScriptableObject.getProperty(scriptable, name);
                if (result == ScriptableObject.NOT_FOUND) {
                    result = Undefined.instance;
                }
            }
        } else {
            int index = ((Integer)id).intValue();
            result = ScriptableObject.getProperty(scriptable, index);
            if (result == ScriptableObject.NOT_FOUND) {
                result = Undefined.instance;
            }
        }
        return result;
    }

    Object[] getObjectIdsImpl(Context cx, Object object)
    {
        if (!(object instanceof Scriptable) || object == Undefined.instance) {
            return Context.emptyArgs;
        }

        Object[] ids;
        Scriptable scriptable = (Scriptable)object;
        if (scriptable instanceof DebuggableObject) {
            ids = ((DebuggableObject)scriptable).getAllIds();
        } else {
            ids = scriptable.getIds();
        }

        Scriptable proto = scriptable.getPrototype();
        Scriptable parent = scriptable.getParentScope();
        int extra = 0;
        if (proto != null) {
            ++extra;
        }
        if (parent != null) {
            ++extra;
        }
        if (extra != 0) {
            Object[] tmp = new Object[extra + ids.length];
            System.arraycopy(ids, 0, tmp, extra, ids.length);
            ids = tmp;
            extra = 0;
            if (proto != null) {
                ids[extra++] = "__proto__";
            }
            if (parent != null) {
                ids[extra++] = "__parent__";
            }
        }

        return ids;
    }

    private void interrupted(Context cx, final StackFrame frame,
                             Throwable scriptException)
    {
        ContextData contextData = frame.contextData();
        int line = frame.getLineNumber();
        String url = frame.getUrl();
        boolean eventThreadFlag = callback.isGuiEventThread();
        contextData.eventThreadFlag = eventThreadFlag;

        boolean recursiveEventThreadCall = false;

      interruptedCheck:
        synchronized (eventThreadMonitor) {
            if (eventThreadFlag) {
                if (interruptedContextData != null) {
                    recursiveEventThreadCall = true;
                    break interruptedCheck;
                }
            } else {
                while (interruptedContextData != null) {
                    try {
                        eventThreadMonitor.wait();
                    } catch (InterruptedException exc) {
                        return;
                    }
                }
            }
            interruptedContextData = contextData;
        }

        if (recursiveEventThreadCall) {
            // XXX: For now the foolowing is commented out as on Linux
            // too deep recursion of dispatchNextGuiEvent causes GUI lockout.
            // Note: it can make GUI unresponsive if long-running script
            // will be called on GUI thread while processing another interrupt
            if (false) {
               // Run event dispatch until gui sets a flag to exit the initial
               // call to interrupted.
                while (this.returnValue == -1) {
                    try {
                        callback.dispatchNextGuiEvent();
                    } catch (InterruptedException exc) {
                    }
                }
            }
            return;
        }

        if (interruptedContextData == null) Kit.codeBug();

        try {
            do {
                int frameCount = contextData.frameCount();
                this.frameIndex = frameCount -1;

                final String threadTitle = Thread.currentThread().toString();
                final String alertMessage;
                if (scriptException == null) {
                    alertMessage = null;
                } else {
                    alertMessage = scriptException.toString();
                }

                int returnValue = -1;
                if (!eventThreadFlag) {
                    synchronized (monitor) {
                        if (insideInterruptLoop) Kit.codeBug();
                        this.insideInterruptLoop = true;
                        this.evalRequest = null;
                        this.returnValue = -1;
                        callback.enterInterrupt(frame, threadTitle,
                                                alertMessage);
                        try {
                            for (;;) {
                                try {
                                    monitor.wait();
                                } catch (InterruptedException exc) {
                                    Thread.currentThread().interrupt();
                                    break;
                                }
                                if (evalRequest != null) {
                                    this.evalResult = null;
                                    try {
                                        evalResult = do_eval(cx, evalFrame,
                                                             evalRequest);
                                    } finally {
                                        evalRequest = null;
                                        evalFrame = null;
                                        monitor.notify();
                                    }
                                    continue;
                                }
                                if (this.returnValue != -1) {
                                    returnValue = this.returnValue;
                                    break;
                                }
                            }
                        } finally {
                            insideInterruptLoop = false;
                        }
                    }
                } else {
                    this.returnValue = -1;
                    callback.enterInterrupt(frame, threadTitle, alertMessage);
                    while (this.returnValue == -1) {
                        try {
                            callback.dispatchNextGuiEvent();
                        } catch (InterruptedException exc) {
                        }
                    }
                    returnValue = this.returnValue;
                }
                switch (returnValue) {
                case STEP_OVER:
                    contextData.breakNextLine = true;
                    contextData.stopAtFrameDepth = contextData.frameCount();
                    break;
                case STEP_INTO:
                    contextData.breakNextLine = true;
                    contextData.stopAtFrameDepth = -1;
                    break;
                case STEP_OUT:
                    if (contextData.frameCount() > 1) {
                        contextData.breakNextLine = true;
                        contextData.stopAtFrameDepth
                            = contextData.frameCount() -1;
                    }
                    break;
                }
            } while (false);
        } finally {
            synchronized (eventThreadMonitor) {
                interruptedContextData = null;
                eventThreadMonitor.notifyAll();
            }
        }

    }

    private static String do_eval(Context cx, StackFrame frame, String expr)
    {
        String resultString;
        Debugger saved_debugger = cx.getDebugger();
        Object saved_data = cx.getDebuggerContextData();
        int saved_level = cx.getOptimizationLevel();

        cx.setDebugger(null, null);
        cx.setOptimizationLevel(-1);
        cx.setGeneratingDebug(false);
        try {
            Callable script = (Callable)cx.compileString(expr, "", 0, null);
            Object result = script.call(cx, frame.scope, frame.thisObj,
                                        ScriptRuntime.emptyArgs);
            if (result == Undefined.instance) {
                resultString = "";
            } else {
                resultString = ScriptRuntime.toString(result);
            }
        } catch (Exception exc) {
            resultString = exc.getMessage();
        } finally {
            cx.setGeneratingDebug(true);
            cx.setOptimizationLevel(saved_level);
            cx.setDebugger(saved_debugger, saved_data);
        }
        if (resultString == null) {
            resultString = "null";
        }
        return resultString;
    }
}