Class ACallFrame

rhino/src/main/java/org/mozilla/javascript/ACallFrame.java:19–218

Interface representing a call frame in the interpreter. This abstraction allows both the original interpreter's CallFrame and InterpreterV2's CallFrameV2 to be used interchangeably for stack traces and debugging purposes.

 * traces and debugging purposes.
 */
public abstract class ACallFrame<T extends ACallFrame<T, U>, U extends ACompilerData<?, U>>
        implements Serializable {
    private static final long serialVersionUID = 6100049821156242226L;

    public final T parentFrame;
    public final short frameIndex;
    public final ACallFrame<?, ?> previousInterpreterFrame;
    public final int parentPC;
    public boolean frozen;

    public ScriptOrFn<?> fnOrScript;
    public U compilerData;

    public final Object[] stack;
    public final byte[] stackAttributes;
    public final double[] doubleStack;

    public Object result;
    public double resultDbl;
    public int pc;
    public int stackTop = -1;
    public VarScope scope;

    // `this' might seem like it should be final, but is actually set
    // by a call to a super constructor and so must be mutable.
    public Scriptable thisObj;

    public final DebugFrame debuggerFrame;
    public final boolean useActivation;

    public ACallFrame<T, U> varSource;
    public final int localShift;
    public final short emptyStackTop;
    public Object throwable;
    final boolean parentStrictness;

    ACallFrame(
            Context cx,
            Scriptable thisObj,
            ScriptOrFn<?> fnOrScript,
            U code,
            T parentFrame,
            ACallFrame<?, ?> previousInterpreterFrame) {
        compilerData = code;
        debuggerFrame =
                cx.debugger != null ? cx.debugger.getFrame(cx, fnOrScript.getDescriptor()) : null;
        useActivation = fnOrScript.getDescriptor().requiresActivationFrame();

        emptyStackTop = (short) (compilerData.maxVars + compilerData.maxLocals - 1);
        int maxFrameArray = compilerData.maxFrameSize;
        if (maxFrameArray != emptyStackTop + compilerData.maxStack + 1) Kit.codeBug();

        stack = new Object[maxFrameArray];
        stackAttributes = new byte[maxFrameArray];
        doubleStack = new double[maxFrameArray];

        this.fnOrScript = fnOrScript;
        localShift = compilerData.maxVars;