Quelle  test_xray_SavedFrame-02.js   Sprache: JAVA

// Test calling SavedFrame getters across wrappers from privileged and
// un-privileged globals.

const {addDebuggerToGlobal} = ChromeUtils.importESModule("resource://gre/modules/jsdebugger.sys.mjs");
addDebuggerToGlobal(globalThis);

const lowP = Services.scriptSecurityManager.createNullPrincipal({});
const highP = Cc["@mozilla.org/systemprincipal;1"].createInstance(Ci.nsIPrincipal);

const low  = new Cu.Sandbox(lowP);
const high = new Cu.Sandbox(highP);

function run_test() {
  // Privileged compartment accessing unprivileged stack.
  high.stack = getSavedFrameInstanceFromSandbox(low);
  Cu.evalInSandbox("this.parent = stack.parent", high);
  Cu.evalInSandbox("this.asyncParent = stack.asyncParent", high);
  Cu.evalInSandbox("this.source = stack.source", high);
  Cu.evalInSandbox("this.functionDisplayName = stack.functionDisplayName", high);

  // Un-privileged compartment accessing privileged stack.
  low.stack = getSavedFrameInstanceFromSandbox(high);
  try {
    Cu.evalInSandbox("this.parent = stack.parent", low);
  } catch (e) { }
  try {
    Cu.evalInSandbox("this.asyncParent = stack.asyncParent", low);
  } catch (e) { }
  try {
    Cu.evalInSandbox("this.source = stack.source", low);
  } catch (e) { }
  try {
    Cu.evalInSandbox("this.functionDisplayName = stack.functionDisplayName", low);
  } catch (e) { }

  // Privileged compartment accessing privileged stack.
  let stack = getSavedFrameInstanceFromSandbox(high);
  let parent = stack.parent;
  let asyncParent = stack.asyncParent;
  let source = stack.source;
  let functionDisplayName = stack.functionDisplayName;

  ok(true, "Didn't crash");
}

// Get a SavedFrame instance from inside the given sandbox.
//
// We can't use Cu.getJSTestingFunctions().saveStack() because Cu isn't
// available to sandboxes that don't have the system principal. The easiest way
// to get the SavedFrame is to use the Debugger API to track allocation sites
// and then do an allocation.
function getSavedFrameInstanceFromSandbox(sandbox) {
  const dbg = new Debugger(sandbox);

  dbg.memory.trackingAllocationSites = true;
  Cu.evalInSandbox("(function iife() { return new RegExp }())", sandbox);
  const allocs = dbg.memory.drainAllocationsLog().filter(e => e.class === "RegExp");
  dbg.memory.trackingAllocationSites = false;

  ok(allocs[0], "We should observe the allocation");
  const { frame } = allocs[0];

  if (sandbox !== high) {
    ok(Cu.isXrayWrapper(frame), "`frame` should be an xray...");
    equal(Object.prototype.toString.call(Cu.waiveXrays(frame)),
          "[object SavedFrame]",
          "...and that xray should wrap a SavedFrame");
  }

  return frame;
}