michael@0: // Test that SavedFrame.prototype.parent gives the next older frame whose
michael@0: // principals are subsumed by the caller's principals.
michael@0: 
michael@0: // Given a string of letters |expected|, say "abc", assert that the stack
michael@0: // contains calls to a series of functions named by the next letter from
michael@0: // the string, say a, b, and then c. Younger frames appear earlier in
michael@0: // |expected| than older frames.
michael@0: function check(expected, stack) {
michael@0:   print("check(" + uneval(expected) + ") against:\n" + stack);
michael@0:   count++;
michael@0: 
michael@0:   while (stack.length && expected.length) {
michael@0:     assertEq(stack.shift(), expected[0]);
michael@0:     expected = expected.slice(1);
michael@0:   }
michael@0: 
michael@0:   if (expected.length > 0) {
michael@0:     throw new Error("Missing frames for: " + expected);
michael@0:   }
michael@0:   if (stack.length > 0 && !stack.every(s => s === null)) {
michael@0:     throw new Error("Unexpected extra frame(s):\n" + stack);
michael@0:   }
michael@0: }
michael@0: 
michael@0: // Go from a SavedFrame linked list to an array of function display names.
michael@0: function extract(stack) {
michael@0:   const results = [];
michael@0:   while (stack) {
michael@0:     results.push(stack.functionDisplayName);
michael@0:     stack = stack.parent;
michael@0:   }
michael@0:   return results;
michael@0: }
michael@0: 
michael@0: const low  = newGlobal({ principal: 0       });
michael@0: const mid  = newGlobal({ principal: 0xffff  });
michael@0: const high = newGlobal({ principal: 0xfffff });
michael@0: 
michael@0: var count = 0;
michael@0: 
michael@0:      eval('function a() { check("a",        extract(saveStack())); b(); }');
michael@0: low .eval('function b() { check("b",        extract(saveStack())); c(); }');
michael@0: mid .eval('function c() { check("cba",      extract(saveStack())); d(); }');
michael@0: high.eval('function d() { check("dcba",     extract(saveStack())); e(); }');
michael@0:      eval('function e() { check("edcba",    extract(saveStack())); f(); }'); // no principal, so checks skipped
michael@0: low .eval('function f() { check("fb",       extract(saveStack())); g(); }');
michael@0: mid .eval('function g() { check("gfecba",   extract(saveStack())); h(); }');
michael@0: high.eval('function h() { check("hgfedcba", extract(saveStack()));      }');
michael@0: 
michael@0: // Make everyone's functions visible to each other, as needed.
michael@0:      b = low .b;
michael@0: low .c = mid .c;
michael@0: mid .d = high.d;
michael@0: high.e =      e;
michael@0:      f = low .f;
michael@0: low .g = mid .g;
michael@0: mid .h = high.h;
michael@0: 
michael@0: low.check = mid.check = high.check = check;
michael@0: 
michael@0: // They each must have their own extract so that CCWs don't mess up the
michael@0: // principals when we ask for the parent property.
michael@0: low. eval("" + extract);
michael@0: mid. eval("" + extract);
michael@0: high.eval("" + extract);
michael@0: 
michael@0: // Kick the whole process off.
michael@0: a();
michael@0: 
michael@0: assertEq(count, 8);