1 files changed, 50 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/Environment-getVariable-13.js b/js/src/jit-test/tests/debug/Environment-getVariable-13.js
new file mode 100644
index 0000000000..37d5e90afc
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Environment-getVariable-13.js
@@ -0,0 +1,50 @@
+// Tests that we can use debug scopes with Ion frames.
+//
+// Unfortunately these tests are brittle. They depend on opaque JIT heuristics
+// kicking in.
+
+load(libdir + "jitopts.js");
+
+// GCs can invalidate JIT code and cause this test to fail.
+gczeal(0);
+
+if (!jitTogglesMatch(Opts_Ion2NoOffthreadCompilation))
+  quit(0);
+
+withJitOptions(Opts_Ion2NoOffthreadCompilation, function () {
+  var g = newGlobal({newCompartment: true});
+  var dbg = new Debugger;
+
+  // Note that this *depends* on CCW scripted functions being opaque to Ion
+  // optimization and not deoptimizing the frames below the call to toggle.
+  g.toggle = function toggle(d) {
+    if (d) {
+      dbg.addDebuggee(g);
+      var frame = dbg.getNewestFrame();
+      assertEq(frame.implementation, "ion");
+      // g is heavyweight but its call object is optimized out, because its
+      // arguments and locals are unaliased.
+      //
+      // Calling frame.environment here should make a fake debug scope that
+      // gets things directly from the frame. Calling frame.arguments doesn't
+      // go through the scope object and reads directly off the frame. Assert
+      // that the two are equal.
+      assertEq(frame.environment.getVariable("x"), frame.arguments[1]);
+    }
+  };
+
+  g.eval("" + function f(d, x) { g(d, x); });
+  g.eval("" + function g(d, x) {
+    for (var i = 0; i < 100; i++);
+    function inner() { i = 42; };
+    toggle(d);
+    // Use x so it doesn't get optimized out.
+    x++;
+  });
+
+  g.eval("(" + function test() {
+    for (i = 0; i < 15; i++)
+      f(false, 42);
+    f(true, 42);
+  } + ")();");
+});