run-in-sandbox.js

/*********************
 * SANDBOXED RUNNING *
 *********************/

// We support three ways to run generated code:
// * useGeckoSandbox(), which uses Components.utils.Sandbox.
//    * In xpcshell, we always use this method, so we don't accidentally erase the hard drive.
//
// * useSpidermonkeyShellSandbox(), which uses evalcx() with newGlobal().
//   * In spidermonkey shell, we often use this method, so we can do additional correctness tests.
//
// * tryRunningDirectly(), which uses eval() or new Function().
//   * This creates the most "interesting" testcases.

var tryRunning = xpcshell ? useGeckoSandbox() : tryRunningDirectly;
function fillShellSandbox(sandbox)
{
  var safeFuns = [
    "print",
    "schedulegc", "selectforgc", "gczeal", "gc", "gcslice",
    "verifyprebarriers", "gcPreserveCode",
    "minorgc", "abortgc",
    "evalcx", "newGlobal", "evaluate",
    "dumpln", "fillShellSandbox",
    "testMathyFunction", "hashStr",
    "isAsmJSCompilationAvailable",
  ];

  for (var i = 0; i < safeFuns.length; ++i) {
    var fn = safeFuns[i];
    if (sandbox[fn]) {
      //print("Target already has " + fn);
    } else if (this[fn]) { // FIXME: strict mode compliance requires passing glob around
      sandbox[fn] = this[fn].bind(this);
    } else {
      //print("Source is missing " + fn);
    }
  }

  return sandbox;
}

function useSpidermonkeyShellSandbox(sandboxType)
{
  var primarySandbox;

  switch (sandboxType) {
    case 0:  primarySandbox = evalcx('');
    case 1:  primarySandbox = evalcx('lazy');
    case 2:  primarySandbox = newGlobal({sameZoneAs: {}}); // same zone
    default: primarySandbox = newGlobal(); // new zone
  }

  fillShellSandbox(primarySandbox);

  return function(f, code, wtt) {
    try {
      evalcx(code, primarySandbox);
    } catch(e) {
      dumpln("Running in sandbox threw " + errorToString(e));
    }
  };
}

// When in xpcshell,
// * Run all testing in a sandbox so it doesn't accidentally wipe my hard drive.
// * Test interaction between sandboxes with same or different principals.
function newGeckoSandbox(n)
{
  var t = (typeof n == "number") ? n : 1;
  var s = Components.utils.Sandbox("http://x" + t + ".example.com/");

  // Allow the sandbox to do a few things
  s.newGeckoSandbox = newGeckoSandbox;
  s.evalInSandbox = function(str, sbx) {
    return Components.utils.evalInSandbox(str, sbx);
  };
  s.print = function(str) { print(str); };

  return s;
}

function useGeckoSandbox() {
  var primarySandbox = newGeckoSandbox(0);

  return function(f, code, wtt) {
    try {
      Components.utils.evalInSandbox(code, primarySandbox);
    } catch(e) {
      // It might not be safe to operate on |e|.
    }
  };
}