diff --git a/js/src/jit-test/tests/debug/Debug-ctor.js b/js/src/jit-test/tests/debug/Debug-ctor-01.js
similarity index 71%
rename from js/src/jit-test/tests/debug/Debug-ctor.js
rename to js/src/jit-test/tests/debug/Debug-ctor-01.js
index 6d07a045858..cd95aad4790 100644
--- a/js/src/jit-test/tests/debug/Debug-ctor.js
+++ b/js/src/jit-test/tests/debug/Debug-ctor-01.js
@@ -1,5 +1,3 @@
-// |jit-test| debug
-
 load(libdir + 'asserts.js');
 
 // Debug rejects arguments that aren't cross-compartment wrappers.
@@ -21,14 +19,3 @@ var g = newGlobal('new-compartment');
 var dbg = new Debug(g);
 assertEq(dbg instanceof Debug, true);
 assertEq(Object.getPrototypeOf(dbg), Debug.prototype);
-
-// The reverse.
-var g2 = newGlobal('new-compartment');
-g2.debuggeeGlobal = this;
-g2.eval("var dbg = new Debug(debuggeeGlobal);");
-assertEq(g2.eval("dbg instanceof Debug"), true);
-
-// The Debug constructor from this compartment will not accept as its argument
-// an Object from this compartment. Shenanigans won't fool the membrane.
-g2.outer = this;
-assertThrowsInstanceOf(function () { g2.eval("outer.Debug(outer.Object())"); }, TypeError);
diff --git a/js/src/jit-test/tests/debug/Debug-ctor-02.js b/js/src/jit-test/tests/debug/Debug-ctor-02.js
new file mode 100644
index 00000000000..eadafd84e04
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Debug-ctor-02.js
@@ -0,0 +1,17 @@
+// |jit-test| debug
+// Test creating a Debug in a sandbox, debugging the initial global.
+//
+// This requires debug mode to already be on in the initial global, since it's
+// always on the stack in the shell. Hence the |jit-test| tag.
+
+load(libdir + 'asserts.js');
+
+var g = newGlobal('new-compartment');
+g.debuggeeGlobal = this;
+g.eval("var dbg = new Debug(debuggeeGlobal);");
+assertEq(g.eval("dbg instanceof Debug"), true);
+
+// The Debug constructor from this compartment will not accept as its argument
+// an Object from this compartment. Shenanigans won't fool the membrane.
+g.parent = this;
+assertThrowsInstanceOf(function () { g.eval("parent.Debug(parent.Object())"); }, TypeError);
diff --git a/js/src/jit-test/tests/debug/Debug-ctor-03.js b/js/src/jit-test/tests/debug/Debug-ctor-03.js
new file mode 100644
index 00000000000..0b4d1e9aecb
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Debug-ctor-03.js
@@ -0,0 +1,6 @@
+// If the debuggee cannot be put into debug mode, throw.
+var g = newGlobal('new-compartment');
+g.libdir = libdir;
+g.eval("load(libdir + 'asserts.js');");
+g.parent = this;
+g.eval("assertThrowsInstanceOf(function () { new Debug(parent); }, Error);");
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-01.js b/js/src/jit-test/tests/debug/Debug-debuggees-01.js
index f2a2893898e..770d2e35992 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-01.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // A Debug object created with no argument initially has no debuggees.
 var dbg = new Debug;
 var debuggees = dbg.getDebuggees();
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-02.js b/js/src/jit-test/tests/debug/Debug-debuggees-02.js
index 3a4d5ea200e..a606625bab0 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-02.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-02.js
@@ -1,5 +1,4 @@
-// |jit-test| debug
-// The array returned by getDebuggees is just a snapshot, not live
+// The array returned by getDebuggees is just a snapshot, not live.
 var dbg = new Debug;
 var a1 = dbg.getDebuggees();
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-03.js b/js/src/jit-test/tests/debug/Debug-debuggees-03.js
index 36b931a8fd2..12e3857dcc2 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-03.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-03.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Debug hooks fire based on debuggees.
 
 var g1 = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-04.js b/js/src/jit-test/tests/debug/Debug-debuggees-04.js
index 725422452e5..5f78d264c13 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-04.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-04.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // hasDebuggee tests.
 
 var g1 = newGlobal('new-compartment'), g1w;
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-05.js b/js/src/jit-test/tests/debug/Debug-debuggees-05.js
index 7599e25b382..f8aa79cf882 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-05.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-05.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // addDebuggee returns different Debug.Object wrappers for different Debug objects.
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-06.js b/js/src/jit-test/tests/debug/Debug-debuggees-06.js
index ccc2614f99a..13a82dc8503 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-06.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-06.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // {has,add,remove}Debuggee throw a TypeError if the argument is invalid.
 
 load(libdir + "asserts.js");
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-07.js b/js/src/jit-test/tests/debug/Debug-debuggees-07.js
index 691dc991a4e..6d38a878819 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-07.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-07.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Handle proto-less objects passed to addDebuggee.
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-08.js b/js/src/jit-test/tests/debug/Debug-debuggees-08.js
index a81e9fa4d9d..facf01abe42 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-08.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-08.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // addDebuggee(obj), where obj is not global, adds obj's global.
 // Adding a debuggee more than once is redundant.
 
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-10.js b/js/src/jit-test/tests/debug/Debug-debuggees-10.js
index 4c3038ffd42..8dcaa1aa02a 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-10.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-10.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // Allow diamonds in the graph of the compartment "debugs" relation.
-
 var program = newGlobal('new-compartment');
 var d1 = newGlobal('new-compartment');
 d1.top = this;
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-12.js b/js/src/jit-test/tests/debug/Debug-debuggees-12.js
index 5e9be612871..944aa854927 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-12.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-12.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // Events in a non-debuggee are ignored, even if a debuggee is in the same compartment.
-
 var g1 = newGlobal('new-compartment');
 var g2 = g1.eval("newGlobal('same-compartment')");
 var dbg = new Debug(g1);
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-13.js b/js/src/jit-test/tests/debug/Debug-debuggees-13.js
index c71e8978a41..0aed7aa254d 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-13.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-13.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // Removing a debuggee does not detach the debugger from a compartment if another debuggee is in it.
-
 var g1 = newGlobal('new-compartment');
 var g2 = g1.eval("newGlobal('same-compartment')");
 var dbg = new Debug(g1, g2);
diff --git a/js/src/jit-test/tests/debug/Debug-debuggees-14.js b/js/src/jit-test/tests/debug/Debug-debuggees-14.js
index 6e19e218273..2329bb5641d 100644
--- a/js/src/jit-test/tests/debug/Debug-debuggees-14.js
+++ b/js/src/jit-test/tests/debug/Debug-debuggees-14.js
@@ -1,11 +1,7 @@
-// Reject non-debug-mode debuggees without asserting.
-
-load(libdir + "asserts.js");
-
-function f() {
-    var v = new Debug;
-    var g = newGlobal('new-compartment');
-    v.addDebuggee(g); // don't assert
-}
-
-assertThrowsInstanceOf(f, Error);
+// Adding a debuggee in a compartment that is already in debug mode works
+// even if a script from that compartment is on the stack.
+var g = newGlobal('new-compartment');
+var dbg1 = Debug(g);
+var dbg2 = Debug();
+g.parent = this;
+g.eval("parent.dbg2.addDebuggee(this);");
diff --git a/js/src/jit-test/tests/debug/Debug-enabled-01.js b/js/src/jit-test/tests/debug/Debug-enabled-01.js
index e4041379778..9e4ad316961 100644
--- a/js/src/jit-test/tests/debug/Debug-enabled-01.js
+++ b/js/src/jit-test/tests/debug/Debug-enabled-01.js
@@ -1,5 +1,3 @@
-// |jit-test| debug
-
 var desc = Object.getOwnPropertyDescriptor(Debug.prototype, "enabled");
 assertEq(typeof desc.get, 'function');
 assertEq(typeof desc.set, 'function');
diff --git a/js/src/jit-test/tests/debug/Debug-getYoungestFrame-01.js b/js/src/jit-test/tests/debug/Debug-getYoungestFrame-01.js
index 38d58cc1b6d..4cc56970f02 100644
--- a/js/src/jit-test/tests/debug/Debug-getYoungestFrame-01.js
+++ b/js/src/jit-test/tests/debug/Debug-getYoungestFrame-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // getYoungestFrame basics.
 
 load(libdir + "asserts.js");
diff --git a/js/src/jit-test/tests/debug/Debug-getYoungestFrame-02.js b/js/src/jit-test/tests/debug/Debug-getYoungestFrame-02.js
index fdffa6aa401..53be1a4e3d7 100644
--- a/js/src/jit-test/tests/debug/Debug-getYoungestFrame-02.js
+++ b/js/src/jit-test/tests/debug/Debug-getYoungestFrame-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Hooks and Debug.prototype.getYoungestFrame produce the same Frame object.
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Debug-multi-01.js b/js/src/jit-test/tests/debug/Debug-multi-01.js
index 27ba90a890e..5b9255df418 100644
--- a/js/src/jit-test/tests/debug/Debug-multi-01.js
+++ b/js/src/jit-test/tests/debug/Debug-multi-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // When there are multiple debuggers, their hooks are called in order.
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Debug-multi-02.js b/js/src/jit-test/tests/debug/Debug-multi-02.js
index 59a448df3f6..a24f86aa3cb 100644
--- a/js/src/jit-test/tests/debug/Debug-multi-02.js
+++ b/js/src/jit-test/tests/debug/Debug-multi-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Test adding hooks during dispatch. The behavior is deterministic and "nice",
 // but mainly what we are checking here is that we do not crash due to
 // modifying a data structure while we're iterating over it.
diff --git a/js/src/jit-test/tests/debug/Debug-multi-03.js b/js/src/jit-test/tests/debug/Debug-multi-03.js
index 1a495149ed1..ed78138021a 100644
--- a/js/src/jit-test/tests/debug/Debug-multi-03.js
+++ b/js/src/jit-test/tests/debug/Debug-multi-03.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Q: But who shall debug the debuggers?  A: jimb
 
 var log = '';
diff --git a/js/src/jit-test/tests/debug/Frame-01.js b/js/src/jit-test/tests/debug/Frame-01.js
index 1ed41e146c7..ee9b502169e 100644
--- a/js/src/jit-test/tests/debug/Frame-01.js
+++ b/js/src/jit-test/tests/debug/Frame-01.js
@@ -1,70 +1,33 @@
-// |jit-test| debug
 // Test .type and .generator fields of topmost stack frame passed to debuggerHandler.
 
 var g = newGlobal('new-compartment');
-g.debuggeeGlobal = this;
-g.eval("var hits;");
-g.eval("(" + function () {
-        var dbg = Debug(debuggeeGlobal);
-        dbg.hooks = {
-            debuggerHandler: function (f) {
-                // print(uneval(expected));
-                assertEq(Object.getPrototypeOf(f), Debug.Frame.prototype);
-                assertEq(f.type, expected.type);
-                assertEq(f.generator, expected.generator);
-                assertEq(f.constructing, expected.constructing);
-                hits++;
-            }
-        };
-    } + ")()");
+var dbg = Debug(g);
+var expected, hits;
+dbg.hooks = {
+    debuggerHandler: function (f) {
+        assertEq(Object.getPrototypeOf(f), Debug.Frame.prototype);
+        assertEq(f.type, expected.type);
+        assertEq(f.generator, expected.generator);
+        assertEq(f.constructing, expected.constructing);
+        hits++;
+    }
+};
 
-g.expected = { type:"global", generator:false, constructing:false };
-g.hits = 0;
-debugger;
-assertEq(g.hits, 1);
-
-g.expected = { type:"call", generator:false, constructing:false };
-g.hits = 0;
-(function () { debugger; })();
-assertEq(g.hits, 1);
-
-g.expected = { type:"call", generator:false, constructing:true };
-g.hits = 0;
-new function() { debugger; };
-assertEq(g.hits, 1);
-
-g.expected = { type:"call", generator:false, constructing:false };
-g.hits = 0;
-new function () {
-    (function() { debugger; })();
-    assertEq(g.hits, 1);
+function test(code, expectobj, expectedHits) {
+    expected = expectobj;
+    hits = 0;
+    g.evaluate(code);
+    assertEq(hits, arguments.length < 3 ? 1 : expectedHits);
 }
 
-g.expected = { type:"eval", generator:false, constructing:false };
-g.hits = 0;
-eval("debugger;");
-assertEq(g.hits, 1);
-
-g.expected = { type:"eval", generator:false, constructing:false };
-g.hits = 0;
-this.eval("debugger;");  // indirect eval
-assertEq(g.hits, 1);
-
-g.expected = { type:"eval", generator:false, constructing:false };
-g.hits = 0;
-(function () { eval("debugger;"); })();
-assertEq(g.hits, 1);
-
-g.expected = { type:"eval", generator:false, constructing:false };
-g.hits = 0;
-new function () {
-    eval("debugger");
-    assertEq(g.hits, 1);
-}
-
-g.expected = { type:"call", generator:true, constructing:false };
-g.hits = 0;
-function gen() { debugger; yield 1; debugger; }
-for (var x in gen()) {
-}
-assertEq(g.hits, 2);
+test("debugger;", {type: "global", generator: false, constructing: false});
+test("(function () { debugger; })();", {type: "call", generator: false, constructing: false});
+test("new function() { debugger; };", {type: "call", generator: false, constructing: true});
+test("new function () { (function() { debugger; })(); }", {type: "call", generator: false, constructing: false});
+test("eval('debugger;');", {type: "eval", generator: false, constructing: false});
+test("this.eval('debugger;');  // indirect eval", {type: "eval", generator: false, constructing: false});
+test("(function () { eval('debugger;'); })();", {type: "eval", generator: false, constructing: false});
+test("new function () { eval('debugger'); }", {type: "eval", generator: false, constructing: false});
+test("function gen() { debugger; yield 1; debugger; }\n" +
+     "for (var x in gen()) {}\n",
+     {type: "call", generator: true, constructing: false}, 2);
diff --git a/js/src/jit-test/tests/debug/Frame-02.js b/js/src/jit-test/tests/debug/Frame-02.js
index 0ebad76a26e..99305eee97e 100644
--- a/js/src/jit-test/tests/debug/Frame-02.js
+++ b/js/src/jit-test/tests/debug/Frame-02.js
@@ -1,35 +1,26 @@
-// |jit-test| debug
 // When the debugger is triggered twice from the same stack frame, the same
 // Debug.Frame object must be passed to the hook both times.
 
 var g = newGlobal('new-compartment');
-g.debuggeeGlobal = this;
-g.eval("var hits, frame;");
-g.eval("(" + function () {
-        var dbg = Debug(debuggeeGlobal);
-        dbg.hooks = {
-            debuggerHandler: function (f) {
-                if (hits++ == 0)
-                    frame = f;
-                else
-                    assertEq(f, frame);
-            }
-        };
-    } + ")()");
+var hits, frame;
+var dbg = Debug(g);
+dbg.hooks = {
+    debuggerHandler: function (f) {
+        if (hits++ == 0)
+            frame = f;
+        else
+            assertEq(f, frame);
+    }
+};
 
-g.hits = 0;
-debugger;
-debugger;
-assertEq(g.hits, 2);
+hits = 0;
+g.evaluate("debugger; debugger;");
+assertEq(hits, 2);
 
-g.hits = 0;
-function f() {
-    debugger;
-    debugger;
-}
-f();
-assertEq(g.hits, 2);
+hits = 0;
+g.evaluate("function f() { debugger; debugger; }  f();");
+assertEq(hits, 2);
 
-g.hits = 0;
-eval("debugger; debugger;");
-assertEq(g.hits, 2);
+hits = 0;
+g.evaluate("eval('debugger; debugger;');");
+assertEq(hits, 2);
diff --git a/js/src/jit-test/tests/debug/Frame-03.js b/js/src/jit-test/tests/debug/Frame-03.js
index 55ef8d86e78..3d19ca6e2a7 100644
--- a/js/src/jit-test/tests/debug/Frame-03.js
+++ b/js/src/jit-test/tests/debug/Frame-03.js
@@ -1,26 +1,21 @@
-// |jit-test| debug
 // When the debugger is triggered from different stack frames that happen to
 // occupy the same memory, it must deliver different Debug.Frame objects.
 
 var g = newGlobal('new-compartment');
-g.debuggeeGlobal = this;
-g.eval("var hits;");
-g.eval("(" + function () {
-        var a = [];
-        var dbg = Debug(debuggeeGlobal);
-        dbg.hooks = {
-            debuggerHandler: function (frame) {
-                for (var i = 0; i < a.length; i++) 
-                    assertEq(a[i] === frame, false);
-                a.push(frame);
-                hits++;
-            }
-        };
-    } + ")()");
+var dbg = Debug(g);
+var hits;
+var a = [];
+dbg.hooks = {
+    debuggerHandler: function (frame) {
+        for (var i = 0; i < a.length; i++) 
+            assertEq(a[i] === frame, false);
+        a.push(frame);
+        hits++;
+    }
+};
 
-function f() { debugger; }
-function h() { debugger; f(); }
-g.hits = 0;
-for (var i = 0; i < 4; i++)
-    h();
-assertEq(g.hits, 8);
+g.eval("function f() { debugger; }");
+g.eval("function h() { debugger; f(); }");
+hits = 0;
+g.eval("for (var i = 0; i < 4; i++) h();");
+assertEq(hits, 8);
diff --git a/js/src/jit-test/tests/debug/Frame-arguments-01.js b/js/src/jit-test/tests/debug/Frame-arguments-01.js
index 7c6099b5b31..b243a94abb7 100644
--- a/js/src/jit-test/tests/debug/Frame-arguments-01.js
+++ b/js/src/jit-test/tests/debug/Frame-arguments-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Frame.prototype.arguments with primitive values
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-arguments-02.js b/js/src/jit-test/tests/debug/Frame-arguments-02.js
index 2e1a6418707..ae6deb2a12e 100644
--- a/js/src/jit-test/tests/debug/Frame-arguments-02.js
+++ b/js/src/jit-test/tests/debug/Frame-arguments-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Object arguments.
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-arguments-03.js b/js/src/jit-test/tests/debug/Frame-arguments-03.js
index ee7d7a6d4d1..8284ebeb87c 100644
--- a/js/src/jit-test/tests/debug/Frame-arguments-03.js
+++ b/js/src/jit-test/tests/debug/Frame-arguments-03.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Destructuring arguments.
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-arguments-04.js b/js/src/jit-test/tests/debug/Frame-arguments-04.js
index 57b5457149d..c618e6b3e89 100644
--- a/js/src/jit-test/tests/debug/Frame-arguments-04.js
+++ b/js/src/jit-test/tests/debug/Frame-arguments-04.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // frame.arguments works for all live frames
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-arguments-05.js b/js/src/jit-test/tests/debug/Frame-arguments-05.js
index 57ee49de83a..ca2b161d924 100644
--- a/js/src/jit-test/tests/debug/Frame-arguments-05.js
+++ b/js/src/jit-test/tests/debug/Frame-arguments-05.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // frame.arguments is "live" (it reflects assignments to arguments).
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-arguments-06.js b/js/src/jit-test/tests/debug/Frame-arguments-06.js
index d9cb415ff9c..e8957888b6c 100644
--- a/js/src/jit-test/tests/debug/Frame-arguments-06.js
+++ b/js/src/jit-test/tests/debug/Frame-arguments-06.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Test extracting frame.arguments element getters and calling them in
 // various awkward ways.
 
diff --git a/js/src/jit-test/tests/debug/Frame-eval-01.js b/js/src/jit-test/tests/debug/Frame-eval-01.js
index 6d57b1ffb4e..57b6f8c8224 100644
--- a/js/src/jit-test/tests/debug/Frame-eval-01.js
+++ b/js/src/jit-test/tests/debug/Frame-eval-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // simplest possible test of Debug.Frame.prototype.eval
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-eval-02.js b/js/src/jit-test/tests/debug/Frame-eval-02.js
index 5cf5b04285b..daaacc1afce 100644
--- a/js/src/jit-test/tests/debug/Frame-eval-02.js
+++ b/js/src/jit-test/tests/debug/Frame-eval-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // frame.eval() throws if frame is not live
 
 load(libdir + "asserts.js");
diff --git a/js/src/jit-test/tests/debug/Frame-eval-03.js b/js/src/jit-test/tests/debug/Frame-eval-03.js
index 51410c382ff..13f1412627b 100644
--- a/js/src/jit-test/tests/debug/Frame-eval-03.js
+++ b/js/src/jit-test/tests/debug/Frame-eval-03.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Test eval-ing names in a topmost script frame
 
 load(libdir + "asserts.js");
diff --git a/js/src/jit-test/tests/debug/Frame-eval-04.js b/js/src/jit-test/tests/debug/Frame-eval-04.js
index 48bb1b05ee3..73017cfe5d7 100644
--- a/js/src/jit-test/tests/debug/Frame-eval-04.js
+++ b/js/src/jit-test/tests/debug/Frame-eval-04.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // frame.eval SyntaxErrors are reflected, not thrown
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-eval-05.js b/js/src/jit-test/tests/debug/Frame-eval-05.js
index 8e48b20832c..986a18622eb 100644
--- a/js/src/jit-test/tests/debug/Frame-eval-05.js
+++ b/js/src/jit-test/tests/debug/Frame-eval-05.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // var declarations in strict frame.eval do not modify the frame
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-eval-06.js b/js/src/jit-test/tests/debug/Frame-eval-06.js
index e799219ef2b..2a573f553c5 100644
--- a/js/src/jit-test/tests/debug/Frame-eval-06.js
+++ b/js/src/jit-test/tests/debug/Frame-eval-06.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // frame.eval throws if frame is a generator frame that isn't currently on the stack
 
 load(libdir + "asserts.js");
diff --git a/js/src/jit-test/tests/debug/Frame-eval-07.js b/js/src/jit-test/tests/debug/Frame-eval-07.js
index 8f7fdd2a05a..fba815527a7 100644
--- a/js/src/jit-test/tests/debug/Frame-eval-07.js
+++ b/js/src/jit-test/tests/debug/Frame-eval-07.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // test frame.eval in non-top frames
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-eval-08.js b/js/src/jit-test/tests/debug/Frame-eval-08.js
index a1405b96301..ae01b07ca48 100644
--- a/js/src/jit-test/tests/debug/Frame-eval-08.js
+++ b/js/src/jit-test/tests/debug/Frame-eval-08.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // The arguments can escape from a function via a debugging hook.
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-eval-09.js b/js/src/jit-test/tests/debug/Frame-eval-09.js
index e8081e9df92..50918fb894e 100644
--- a/js/src/jit-test/tests/debug/Frame-eval-09.js
+++ b/js/src/jit-test/tests/debug/Frame-eval-09.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // assigning to local variables in frame.eval code
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-eval-10.js b/js/src/jit-test/tests/debug/Frame-eval-10.js
index 694631c3690..5cd3d2641fa 100644
--- a/js/src/jit-test/tests/debug/Frame-eval-10.js
+++ b/js/src/jit-test/tests/debug/Frame-eval-10.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // frame.eval returns null if the eval code fails with an uncatchable error.
 var g = newGlobal('new-compartment');
 var dbg = Debug(g);
diff --git a/js/src/jit-test/tests/debug/Frame-evalWithBindings-01.js b/js/src/jit-test/tests/debug/Frame-evalWithBindings-01.js
index ebaf01fc08e..8892d411ae0 100644
--- a/js/src/jit-test/tests/debug/Frame-evalWithBindings-01.js
+++ b/js/src/jit-test/tests/debug/Frame-evalWithBindings-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // evalWithBindings basics
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-evalWithBindings-02.js b/js/src/jit-test/tests/debug/Frame-evalWithBindings-02.js
index bc23b258ab3..29c10167501 100644
--- a/js/src/jit-test/tests/debug/Frame-evalWithBindings-02.js
+++ b/js/src/jit-test/tests/debug/Frame-evalWithBindings-02.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // evalWithBindings to call a method of a debuggee object
-
 var g = newGlobal('new-compartment');
 var dbg = new Debug;
 var global = dbg.addDebuggee(g);
diff --git a/js/src/jit-test/tests/debug/Frame-evalWithBindings-03.js b/js/src/jit-test/tests/debug/Frame-evalWithBindings-03.js
index e7f670addff..13b2e82bb8e 100644
--- a/js/src/jit-test/tests/debug/Frame-evalWithBindings-03.js
+++ b/js/src/jit-test/tests/debug/Frame-evalWithBindings-03.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // arguments works in evalWithBindings (it does not interpose a function scope)
-
 var g = newGlobal('new-compartment');
 var dbg = new Debug;
 var global = dbg.addDebuggee(g);
diff --git a/js/src/jit-test/tests/debug/Frame-evalWithBindings-04.js b/js/src/jit-test/tests/debug/Frame-evalWithBindings-04.js
index 270b67258c0..e0f59736733 100644
--- a/js/src/jit-test/tests/debug/Frame-evalWithBindings-04.js
+++ b/js/src/jit-test/tests/debug/Frame-evalWithBindings-04.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // evalWithBindings works on non-top frames.
-
 var g = newGlobal('new-compartment');
 var dbg = new Debug(g);
 var f1;
diff --git a/js/src/jit-test/tests/debug/Frame-evalWithBindings-05.js b/js/src/jit-test/tests/debug/Frame-evalWithBindings-05.js
index 88fd99263a0..45b192549eb 100644
--- a/js/src/jit-test/tests/debug/Frame-evalWithBindings-05.js
+++ b/js/src/jit-test/tests/debug/Frame-evalWithBindings-05.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // evalWithBindings code can assign to the bindings.
 var g = newGlobal('new-compartment');
 var dbg = new Debug(g);
diff --git a/js/src/jit-test/tests/debug/Frame-evalWithBindings-06.js b/js/src/jit-test/tests/debug/Frame-evalWithBindings-06.js
index d6c8a7d1745..6d3abea9662 100644
--- a/js/src/jit-test/tests/debug/Frame-evalWithBindings-06.js
+++ b/js/src/jit-test/tests/debug/Frame-evalWithBindings-06.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // In evalWithBindings code, assignment to any name not in the bindings works just as in eval.
-
 var g = newGlobal('new-compartment');
 var dbg = new Debug(g);
 dbg.hooks = {
diff --git a/js/src/jit-test/tests/debug/Frame-evalWithBindings-07.js b/js/src/jit-test/tests/debug/Frame-evalWithBindings-07.js
index c2508ebece4..3f47e37e3c8 100644
--- a/js/src/jit-test/tests/debug/Frame-evalWithBindings-07.js
+++ b/js/src/jit-test/tests/debug/Frame-evalWithBindings-07.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // var statements in strict evalWithBindings code behave like strict eval.
-
 var g = newGlobal('new-compartment');
 var dbg = new Debug(g);
 var hits = 0;
diff --git a/js/src/jit-test/tests/debug/Frame-evalWithBindings-08.js b/js/src/jit-test/tests/debug/Frame-evalWithBindings-08.js
index 9168bb31932..a59d672eea9 100644
--- a/js/src/jit-test/tests/debug/Frame-evalWithBindings-08.js
+++ b/js/src/jit-test/tests/debug/Frame-evalWithBindings-08.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // evalWithBindings ignores non-enumerable and non-own properties.
-
 var g = newGlobal('new-compartment');
 var dbg = new Debug(g);
 var hits = 0;
diff --git a/js/src/jit-test/tests/debug/Frame-evalWithBindings-09.js b/js/src/jit-test/tests/debug/Frame-evalWithBindings-09.js
index d98574f5c5b..8f761572cb2 100644
--- a/js/src/jit-test/tests/debug/Frame-evalWithBindings-09.js
+++ b/js/src/jit-test/tests/debug/Frame-evalWithBindings-09.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // evalWithBindings code is debuggee code, so it can trip the debugger. It nests!
-
 var g = newGlobal('new-compartment');
 var dbg = new Debug(g);
 var f1;
diff --git a/js/src/jit-test/tests/debug/Frame-evalWithBindings-10.js b/js/src/jit-test/tests/debug/Frame-evalWithBindings-10.js
index 9dd30432ae5..5407c8e9c28 100644
--- a/js/src/jit-test/tests/debug/Frame-evalWithBindings-10.js
+++ b/js/src/jit-test/tests/debug/Frame-evalWithBindings-10.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // Direct eval code under evalWithbindings sees both the bindings and the enclosing scope.
-
 var g = newGlobal('new-compartment');
 var dbg = new Debug(g);
 var hits = 0;
diff --git a/js/src/jit-test/tests/debug/Frame-identity-04.js b/js/src/jit-test/tests/debug/Frame-identity-04.js
index 8cf70f95a5b..8e10b73f823 100644
--- a/js/src/jit-test/tests/debug/Frame-identity-04.js
+++ b/js/src/jit-test/tests/debug/Frame-identity-04.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Test that on-stack Debug.Frames are not GC'd even if they are only reachable
 // from the js::Debug::frames table.
 
diff --git a/js/src/jit-test/tests/debug/Frame-live-03.js b/js/src/jit-test/tests/debug/Frame-live-03.js
index 56cfcc966cf..e2c3f31bb44 100644
--- a/js/src/jit-test/tests/debug/Frame-live-03.js
+++ b/js/src/jit-test/tests/debug/Frame-live-03.js
@@ -4,18 +4,15 @@
 load(libdir + "asserts.js");
 
 var g = newGlobal('new-compartment');
-g.debuggeeGlobal = this;
-g.eval("var f;");
-g.eval("(" + function () {
-        Debug(debuggeeGlobal).hooks = {
-            debuggerHandler: function (frame) {
-                assertEq(frame.type, "call");
-                assertEq(frame.live, true);
-                f = frame;
-            }
-        };
-    } + ")()");
+var f;
+Debug(g).hooks = {
+    debuggerHandler: function (frame) {
+        assertEq(frame.type, "call");
+        assertEq(frame.live, true);
+        f = frame;
+    }
+};
 
-(function () { debugger; })();
-assertEq(g.f.live, false);
-assertThrowsInstanceOf(function () { g.f.type; }, g.Error);
+g.eval("(function () { debugger; })();");
+assertEq(f.live, false);
+assertThrowsInstanceOf(function () { f.type; }, Error);
diff --git a/js/src/jit-test/tests/debug/Frame-live-04.js b/js/src/jit-test/tests/debug/Frame-live-04.js
new file mode 100644
index 00000000000..4fd6275ddfe
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Frame-live-04.js
@@ -0,0 +1,28 @@
+// Frame.live is false for frames discarded during uncatchable error unwinding.
+var g = newGlobal('new-compartment');
+var dbg = Debug(g);
+var hits = 0;
+var snapshot;
+dbg.hooks = {
+    debuggerHandler: function (frame) {
+	var stack = [];
+	for (var f = frame; f; f = f.older) {
+	    if (f.type === "call")
+		stack.push(f);
+	}
+	snapshot = stack;
+	if (hits++ === 0)
+	    assertEq(frame.eval("x();"), null);
+	else
+	    return null;
+    }
+};
+
+g.eval("function z() { debugger; }");
+g.eval("function y() { z(); }");
+g.eval("function x() { y(); }");
+assertEq(g.eval("debugger; 'ok';"), "ok");
+assertEq(hits, 2);
+assertEq(snapshot.length, 3);
+for (var i = 0; i < snapshot.length; i++)
+    assertEq(snapshot[i].live, false);
diff --git a/js/src/jit-test/tests/debug/Frame-older-01.js b/js/src/jit-test/tests/debug/Frame-older-01.js
index e2419eaeacf..bde3b4cbe8c 100644
--- a/js/src/jit-test/tests/debug/Frame-older-01.js
+++ b/js/src/jit-test/tests/debug/Frame-older-01.js
@@ -2,24 +2,21 @@
 // Basic call chain.
 
 var g = newGlobal('new-compartment');
-g.debuggeeGlobal = this;
-g.result = null;
-g.eval("(" + function () {
-        var dbg = new Debug(debuggeeGlobal);
-        dbg.hooks = {
-            debuggerHandler: function (frame) {
-                var a = [];
-                assertEq(frame === frame.older, false);
-                for (; frame; frame = frame.older)
-                    a.push(frame.type === 'call' ? frame.callee.name : frame.type);
-                a.reverse();
-                result = a.join(", ");
-            }
-        };
-    } + ")();");
+var result = null;
+var dbg = new Debug(g);
+dbg.hooks = {
+    debuggerHandler: function (frame) {
+        var a = [];
+        assertEq(frame === frame.older, false);
+        for (; frame; frame = frame.older)
+            a.push(frame.type === 'call' ? frame.callee.name : frame.type);
+        a.reverse();
+        result = a.join(", ");
+    }
+};
 
-function first() { return second(); }
-function second() { return eval("third()"); }
-function third() { debugger; }
-first();
-assertEq(g.result, "global, first, second, eval, third");
+g.eval("function first() { return second(); }");
+g.eval("function second() { return eval('third()'); }");
+g.eval("function third() { debugger; }");
+g.evaluate("first();");
+assertEq(result, "global, first, second, eval, third");
diff --git a/js/src/jit-test/tests/debug/Frame-this-01.js b/js/src/jit-test/tests/debug/Frame-this-01.js
index 862c3e88e61..5eb81aa5935 100644
--- a/js/src/jit-test/tests/debug/Frame-this-01.js
+++ b/js/src/jit-test/tests/debug/Frame-this-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Frame.prototype.this in strict-mode functions, with primitive values
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-this-02.js b/js/src/jit-test/tests/debug/Frame-this-02.js
index c87b10656a7..5ce0d4b4781 100644
--- a/js/src/jit-test/tests/debug/Frame-this-02.js
+++ b/js/src/jit-test/tests/debug/Frame-this-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Frame.prototype.this in strict direct eval frames
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Frame-this-03.js b/js/src/jit-test/tests/debug/Frame-this-03.js
index c98b426fdcf..78454d20326 100644
--- a/js/src/jit-test/tests/debug/Frame-this-03.js
+++ b/js/src/jit-test/tests/debug/Frame-this-03.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Frame.prototype.this in non-strict-mode functions, with primitive values
 
 function classOf(obj) {
diff --git a/js/src/jit-test/tests/debug/Frame-this-04.js b/js/src/jit-test/tests/debug/Frame-this-04.js
index 913320262ed..2efbb397615 100644
--- a/js/src/jit-test/tests/debug/Frame-this-04.js
+++ b/js/src/jit-test/tests/debug/Frame-this-04.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Debug.Frame.prototype.this in functions, with object values
 
 function classOf(obj) {
diff --git a/js/src/jit-test/tests/debug/Object-01.js b/js/src/jit-test/tests/debug/Object-01.js
index b8dccd3bf8c..7bc74f431b7 100644
--- a/js/src/jit-test/tests/debug/Object-01.js
+++ b/js/src/jit-test/tests/debug/Object-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Debug.Object basics
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Object-apply-01.js b/js/src/jit-test/tests/debug/Object-apply-01.js
index 8598d38669f..30e0d6fe5b4 100644
--- a/js/src/jit-test/tests/debug/Object-apply-01.js
+++ b/js/src/jit-test/tests/debug/Object-apply-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // tests calling script functions via Debug.Object.prototype.apply/call
 
 load(libdir + "asserts.js");
diff --git a/js/src/jit-test/tests/debug/Object-apply-02.js b/js/src/jit-test/tests/debug/Object-apply-02.js
index ddd758c23ed..1eef67edb40 100644
--- a/js/src/jit-test/tests/debug/Object-apply-02.js
+++ b/js/src/jit-test/tests/debug/Object-apply-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // tests calling native functions via Debug.Object.prototype.apply/call
 
 load(libdir + "asserts.js");
diff --git a/js/src/jit-test/tests/debug/Object-apply-03.js b/js/src/jit-test/tests/debug/Object-apply-03.js
index f1a24b215de..2bff00c74be 100644
--- a/js/src/jit-test/tests/debug/Object-apply-03.js
+++ b/js/src/jit-test/tests/debug/Object-apply-03.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // reentering the debugger several times via debuggerHandler and apply/call on a single stack
 
 var g = newGlobal("new-compartment");
diff --git a/js/src/jit-test/tests/debug/Object-apply-04.js b/js/src/jit-test/tests/debug/Object-apply-04.js
index 78b69463895..6da2e3b918e 100644
--- a/js/src/jit-test/tests/debug/Object-apply-04.js
+++ b/js/src/jit-test/tests/debug/Object-apply-04.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Debug.Object.prototype.apply/call works with function proxies
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Object-callable.js b/js/src/jit-test/tests/debug/Object-callable.js
index a8e9056e418..49313643f90 100644
--- a/js/src/jit-test/tests/debug/Object-callable.js
+++ b/js/src/jit-test/tests/debug/Object-callable.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Test Debug.Object.prototype.callable.
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Object-class.js b/js/src/jit-test/tests/debug/Object-class.js
index 33493efcff2..529137da665 100644
--- a/js/src/jit-test/tests/debug/Object-class.js
+++ b/js/src/jit-test/tests/debug/Object-class.js
@@ -1,5 +1,4 @@
-// |jit-test| debug
-
+// Basic tests for Debug.Object.prototype.class.
 var g = newGlobal('new-compartment');
 var dbg = new Debug(g);
 var hits = 0;
@@ -14,6 +13,5 @@ dbg.hooks = {
         hits++;
     }
 };
-
 g.eval("(function () { debugger; })(Object.prototype, [], eval, new Date, Proxy.create({}));");
 assertEq(hits, 1);
diff --git a/js/src/jit-test/tests/debug/Object-identity-01.js b/js/src/jit-test/tests/debug/Object-identity-01.js
index 957cdd92bdd..d8f4c5a9cd3 100644
--- a/js/src/jit-test/tests/debug/Object-identity-01.js
+++ b/js/src/jit-test/tests/debug/Object-identity-01.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // Two references to the same object get the same Debug.Object wrapper.
-
 var g = newGlobal('new-compartment');
 var dbg = Debug(g);
 var hits = 0;
diff --git a/js/src/jit-test/tests/debug/Object-identity-02.js b/js/src/jit-test/tests/debug/Object-identity-02.js
index c082874472e..a58d73956bb 100644
--- a/js/src/jit-test/tests/debug/Object-identity-02.js
+++ b/js/src/jit-test/tests/debug/Object-identity-02.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // Different objects get different Debug.Object wrappers.
-
 var g = newGlobal('new-compartment');
 var dbg = Debug(g);
 var hits = 0;
diff --git a/js/src/jit-test/tests/debug/Object-identity-03.js b/js/src/jit-test/tests/debug/Object-identity-03.js
index 75e4abbd145..81feb786263 100644
--- a/js/src/jit-test/tests/debug/Object-identity-03.js
+++ b/js/src/jit-test/tests/debug/Object-identity-03.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // The same object gets the same Debug.Object wrapper at different times, if the difference would be observable.
 
 var N = HOTLOOP + 4;
diff --git a/js/src/jit-test/tests/debug/Object-name-01.js b/js/src/jit-test/tests/debug/Object-name-01.js
index b59eca69dfb..d59e36237ff 100644
--- a/js/src/jit-test/tests/debug/Object-name-01.js
+++ b/js/src/jit-test/tests/debug/Object-name-01.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // Debug.Object.prototype.name
-
 var g = newGlobal('new-compartment');
 var dbg = Debug(g);
 var name, hits;
diff --git a/js/src/jit-test/tests/debug/Object-name-02.js b/js/src/jit-test/tests/debug/Object-name-02.js
index 3096335dd15..b81c155476d 100644
--- a/js/src/jit-test/tests/debug/Object-name-02.js
+++ b/js/src/jit-test/tests/debug/Object-name-02.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // The .name of a non-function object is undefined.
-
 var g = newGlobal('new-compartment');
 var hits = 0;
 var dbg = new Debug(g);
diff --git a/js/src/jit-test/tests/debug/Object-parameterNames.js b/js/src/jit-test/tests/debug/Object-parameterNames.js
index e89343626c8..0e365bfa0d2 100644
--- a/js/src/jit-test/tests/debug/Object-parameterNames.js
+++ b/js/src/jit-test/tests/debug/Object-parameterNames.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 load(libdir + 'array-compare.js');
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/Object-proto.js b/js/src/jit-test/tests/debug/Object-proto.js
index caecdcf17d9..511ce8343c7 100644
--- a/js/src/jit-test/tests/debug/Object-proto.js
+++ b/js/src/jit-test/tests/debug/Object-proto.js
@@ -1,4 +1,4 @@
-// |jit-test| debug
+// Debug.Object.prototype.proto
 var g = newGlobal('new-compartment');
 var dbgeval = function () {
         var dbg = new Debug(g);
diff --git a/js/src/jit-test/tests/debug/dispatch-01.js b/js/src/jit-test/tests/debug/dispatch-01.js
index 6239a91d490..2a1c3bf875c 100644
--- a/js/src/jit-test/tests/debug/dispatch-01.js
+++ b/js/src/jit-test/tests/debug/dispatch-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Test removing hooks during dispatch.
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/dispatch-02.js b/js/src/jit-test/tests/debug/dispatch-02.js
index e5b81511a36..0644fb3e216 100644
--- a/js/src/jit-test/tests/debug/dispatch-02.js
+++ b/js/src/jit-test/tests/debug/dispatch-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Disabling a Debug object causes events to stop being delivered to it
 // immediately, even if we're in the middle of dispatching.
 
diff --git a/js/src/jit-test/tests/debug/gc-01.js b/js/src/jit-test/tests/debug/gc-01.js
index f0526bbb922..6844ca1e2e9 100644
--- a/js/src/jit-test/tests/debug/gc-01.js
+++ b/js/src/jit-test/tests/debug/gc-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Debuggers with enabled hooks should not be GC'd even if they are otherwise
 // unreachable.
 
diff --git a/js/src/jit-test/tests/debug/gc-02.js b/js/src/jit-test/tests/debug/gc-02.js
index a4ff9f9d731..2765f6ac691 100644
--- a/js/src/jit-test/tests/debug/gc-02.js
+++ b/js/src/jit-test/tests/debug/gc-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Dispatching an event to a debugger must keep enough of it gc-alive to avoid
 // crashing.
 
diff --git a/js/src/jit-test/tests/debug/gc-03.js b/js/src/jit-test/tests/debug/gc-03.js
index d6e1d57e198..27b95606013 100644
--- a/js/src/jit-test/tests/debug/gc-03.js
+++ b/js/src/jit-test/tests/debug/gc-03.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Storing a property on a Debug.Object protects it from GC as long as the
 // referent is alive.
 
diff --git a/js/src/jit-test/tests/debug/gc-04.js b/js/src/jit-test/tests/debug/gc-04.js
index 8ea9a6f6d15..11031b54586 100644
--- a/js/src/jit-test/tests/debug/gc-04.js
+++ b/js/src/jit-test/tests/debug/gc-04.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Storing a Debug.Object as a key in a WeakMap protects it from GC as long as
 // the referent is alive.
 
diff --git a/js/src/jit-test/tests/debug/gc-05.js b/js/src/jit-test/tests/debug/gc-05.js
index df3076899b5..324e2968f26 100644
--- a/js/src/jit-test/tests/debug/gc-05.js
+++ b/js/src/jit-test/tests/debug/gc-05.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // If a Debug survives its debuggee, its object cache must still be swept.
 
 var g2arr = []; // non-debuggee globals
diff --git a/js/src/jit-test/tests/debug/gc-06.js b/js/src/jit-test/tests/debug/gc-06.js
index 92d0d895c16..522bcb4fe62 100644
--- a/js/src/jit-test/tests/debug/gc-06.js
+++ b/js/src/jit-test/tests/debug/gc-06.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // Debug objects do not keep debuggee globals live.
-
 var dbg = new Debug;
 for (var i = 0; i < 4; i++)
     dbg.addDebuggee(newGlobal('new-compartment'));
diff --git a/js/src/jit-test/tests/debug/gc-07.js b/js/src/jit-test/tests/debug/gc-07.js
index 2b1de3e8b37..79e71d1d51a 100644
--- a/js/src/jit-test/tests/debug/gc-07.js
+++ b/js/src/jit-test/tests/debug/gc-07.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // Don't assert with dead Debug.Object and live cross-compartment wrapper of referent.
-
 var g = newGlobal('new-compartment');
 for (var j = 0; j < 4; j++) {
     var dbg = new Debug;
diff --git a/js/src/jit-test/tests/debug/gc-08.js b/js/src/jit-test/tests/debug/gc-08.js
index 4d5e16a39c4..5c9cfa40a9a 100644
--- a/js/src/jit-test/tests/debug/gc-08.js
+++ b/js/src/jit-test/tests/debug/gc-08.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Debuggers with enabled throw hooks should not be GC'd even if they are
 // otherwise unreachable.
 
diff --git a/js/src/jit-test/tests/debug/hooks-debuggerHandler-01.js b/js/src/jit-test/tests/debug/hooks-debuggerHandler-01.js
index 9ae99dbf8ff..fcabbee1185 100644
--- a/js/src/jit-test/tests/debug/hooks-debuggerHandler-01.js
+++ b/js/src/jit-test/tests/debug/hooks-debuggerHandler-01.js
@@ -1,13 +1,8 @@
-// |jit-test| debug
 var g = newGlobal('new-compartment');
 g.log = '';
 
 var dbg = Debug(g);
-var hooks = {
-    debuggerHandler: function (stack) {
-        g.log += '!';
-    }
-};
+var hooks = {debuggerHandler: function (stack) { g.log += '!'; }};
 dbg.hooks = hooks;
 assertEq(dbg.hooks, hooks);
 assertEq(g.eval("log += '1'; debugger; log += '2'; 3;"), 3);
diff --git a/js/src/jit-test/tests/debug/hooks-debuggerHandler-02.js b/js/src/jit-test/tests/debug/hooks-debuggerHandler-02.js
index 0f61e6c6a06..e79f8ecdcda 100644
--- a/js/src/jit-test/tests/debug/hooks-debuggerHandler-02.js
+++ b/js/src/jit-test/tests/debug/hooks-debuggerHandler-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Activity in the debugger compartment should not trigger debug hooks.
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/hooks-debuggerHandler-03.js b/js/src/jit-test/tests/debug/hooks-debuggerHandler-03.js
index 2c5af905cc0..2c4cecdeb1f 100644
--- a/js/src/jit-test/tests/debug/hooks-debuggerHandler-03.js
+++ b/js/src/jit-test/tests/debug/hooks-debuggerHandler-03.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // A debugger statement in a debuggerHandler should not reenter.
 
 var g = newGlobal('new-compartment');
diff --git a/js/src/jit-test/tests/debug/hooks-deleted.js b/js/src/jit-test/tests/debug/hooks-deleted.js
index 27ee53a6f03..eef212289bb 100644
--- a/js/src/jit-test/tests/debug/hooks-deleted.js
+++ b/js/src/jit-test/tests/debug/hooks-deleted.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // If a hook is deleted after setHooks or overwritten with a primitive, it
 // simply isn't called.
 
diff --git a/js/src/jit-test/tests/debug/hooks-throw-01.js b/js/src/jit-test/tests/debug/hooks-throw-01.js
index 3ab429af98f..8757bf3ac03 100644
--- a/js/src/jit-test/tests/debug/hooks-throw-01.js
+++ b/js/src/jit-test/tests/debug/hooks-throw-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Basic throw hook test.
 
 load(libdir + "asserts.js");
diff --git a/js/src/jit-test/tests/debug/hooks-throw-04.js b/js/src/jit-test/tests/debug/hooks-throw-04.js
index f5343caee6a..d5e6e38cd22 100644
--- a/js/src/jit-test/tests/debug/hooks-throw-04.js
+++ b/js/src/jit-test/tests/debug/hooks-throw-04.js
@@ -1,6 +1,4 @@
-// |jit-test| debug
 // hooks.throw is not called for exceptions thrown and handled in the debugger.
-
 var g = newGlobal('new-compartment');
 var dbg = Debug(g);
 g.log = '';
diff --git a/js/src/jit-test/tests/debug/resumption-01.js b/js/src/jit-test/tests/debug/resumption-01.js
index 5438dfc6d0a..7f4cab188f5 100644
--- a/js/src/jit-test/tests/debug/resumption-01.js
+++ b/js/src/jit-test/tests/debug/resumption-01.js
@@ -1,10 +1,8 @@
-// |jit-test| debug
 // Simple {throw:} resumption.
 
 load(libdir + "asserts.js");
 
 var g = newGlobal('new-compartment');
-
 var dbg = Debug(g);
 dbg.hooks = {
     debuggerHandler: function (stack) {
diff --git a/js/src/jit-test/tests/debug/resumption-02.js b/js/src/jit-test/tests/debug/resumption-02.js
index efdb64f5487..f24451991f3 100644
--- a/js/src/jit-test/tests/debug/resumption-02.js
+++ b/js/src/jit-test/tests/debug/resumption-02.js
@@ -1,8 +1,5 @@
-// |jit-test| debug
 // Simple {return:} resumption.
-
 var g = newGlobal('new-compartment');
-
 var dbg = Debug(g);
 dbg.hooks = {
     debuggerHandler: function (stack) {
diff --git a/js/src/jit-test/tests/debug/surfaces-01.js b/js/src/jit-test/tests/debug/surfaces-01.js
index 8a04693773c..495937ba884 100644
--- a/js/src/jit-test/tests/debug/surfaces-01.js
+++ b/js/src/jit-test/tests/debug/surfaces-01.js
@@ -1,4 +1,4 @@
-// |jit-test| debug
+// Check superficial characteristics of functions and properties (not functionality).
 
 function checkFunction(obj, name, nargs) {
     var desc = Object.getOwnPropertyDescriptor(obj, name);
diff --git a/js/src/jit-test/tests/debug/surfaces-02.js b/js/src/jit-test/tests/debug/surfaces-02.js
index f599b42eaec..ceac1fbd941 100644
--- a/js/src/jit-test/tests/debug/surfaces-02.js
+++ b/js/src/jit-test/tests/debug/surfaces-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Debug.prototype.hooks
 
 load(libdir + 'asserts.js');
diff --git a/js/src/jit-test/tests/debug/surfaces-03.js b/js/src/jit-test/tests/debug/surfaces-03.js
index 523a03620e8..6ee6ec1b1da 100644
--- a/js/src/jit-test/tests/debug/surfaces-03.js
+++ b/js/src/jit-test/tests/debug/surfaces-03.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // dumb basics of uncaughtExceptionHook
 
 load(libdir + 'asserts.js');
diff --git a/js/src/jit-test/tests/debug/uncaughtExceptionHook-01.js b/js/src/jit-test/tests/debug/uncaughtExceptionHook-01.js
index 4ca3230568f..5d9f0e87bf3 100644
--- a/js/src/jit-test/tests/debug/uncaughtExceptionHook-01.js
+++ b/js/src/jit-test/tests/debug/uncaughtExceptionHook-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Uncaught exceptions in the debugger itself are delivered to the
 // uncaughtExceptionHook.
 
diff --git a/js/src/jit-test/tests/debug/uncaughtExceptionHook-02.js b/js/src/jit-test/tests/debug/uncaughtExceptionHook-02.js
index ec4bd8a6db8..5c77d0d3713 100644
--- a/js/src/jit-test/tests/debug/uncaughtExceptionHook-02.js
+++ b/js/src/jit-test/tests/debug/uncaughtExceptionHook-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // Returning a bad resumption value causes an exception that is reported to the
 // uncaughtExceptionHook.
 
diff --git a/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-01.js b/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-01.js
index e30cb793327..c253317fc6c 100644
--- a/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-01.js
+++ b/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-01.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // uncaughtExceptionHook returns a resumption value.
 
 load(libdir + "asserts.js");
diff --git a/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-02.js b/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-02.js
index f2fbda68ab4..a15257e218c 100644
--- a/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-02.js
+++ b/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-02.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // uncaughtExceptionHook resumption value other than undefined causes further
 // hooks to be skipped.
 
diff --git a/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-03.js b/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-03.js
index 67c64d99f2c..ffa67171346 100644
--- a/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-03.js
+++ b/js/src/jit-test/tests/debug/uncaughtExceptionHook-resumption-03.js
@@ -1,4 +1,3 @@
-// |jit-test| debug
 // After hooks.throw throws, if uncaughtExceptionHook returns undefined,
 // the original exception continues to propagate.
 
diff --git a/js/src/jsanalyze.cpp b/js/src/jsanalyze.cpp
index e7ebbeaaeb2..91c138e0245 100644
--- a/js/src/jsanalyze.cpp
+++ b/js/src/jsanalyze.cpp
@@ -315,7 +315,7 @@ Script::analyze(JSContext *cx, JSScript *script)
      * by debug code or by eval, or if they could be accessed by an inner script.
      */
 
-    if (script->usesEval || cx->compartment->debugMode) {
+    if (script->usesEval || cx->compartment->debugMode()) {
         for (uint32 i = 0; i < nfixed; i++)
             setLocal(i, LOCAL_USE_BEFORE_DEF);
     }
@@ -330,7 +330,7 @@ Script::analyze(JSContext *cx, JSScript *script)
      * If the script is in debug mode, JS_SetFrameReturnValue can be called at
      * any safe point.
      */
-    if (cx->compartment->debugMode)
+    if (cx->compartment->debugMode())
         usesRval = true;
 
     /*
diff --git a/js/src/jsapi-tests/testDebugger.cpp b/js/src/jsapi-tests/testDebugger.cpp
index 3201f15f117..45498f2f50a 100644
--- a/js/src/jsapi-tests/testDebugger.cpp
+++ b/js/src/jsapi-tests/testDebugger.cpp
@@ -139,7 +139,7 @@ BEGIN_TEST(testDebugger_debugObjectVsDebugMode)
     EVAL("debuggee.eval('debugger; debugger; debugger;');\n"
          "hits;\n",
          &v);
-    CHECK_SAME(v, JSVAL_ONE);
+    CHECK_SAME(v, INT_TO_JSVAL(4));
     
     return true;
 }
diff --git a/js/src/jsapi.cpp b/js/src/jsapi.cpp
index 00cfadff2bf..595287fc56c 100644
--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -707,7 +707,7 @@ JSRuntime::init(uint32 maxbytes)
         return false;
 #endif
 
-    debugMode = JS_FALSE;
+    debugMode = false;
     return js_InitThreads(this);
 }
 
diff --git a/js/src/jscntxt.h b/js/src/jscntxt.h
index ba5f56a48ee..f188894e598 100644
--- a/js/src/jscntxt.h
+++ b/js/src/jscntxt.h
@@ -495,7 +495,7 @@ struct JSRuntime {
     /*
      * Right now, we only support runtime-wide debugging.
      */
-    JSBool              debugMode;
+    bool                debugMode;
 
 #ifdef JS_TRACER
     /* True if any debug hooks not supported by the JIT are enabled. */
diff --git a/js/src/jscompartment.cpp b/js/src/jscompartment.cpp
index 30e56054107..05459ce7025 100644
--- a/js/src/jscompartment.cpp
+++ b/js/src/jscompartment.cpp
@@ -87,7 +87,7 @@ JSCompartment::JSCompartment(JSRuntime *rt)
     emptyWithShape(NULL),
     initialRegExpShape(NULL),
     initialStringShape(NULL),
-    debugMode(rt->debugMode),
+    debugModeBits(rt->debugMode * DebugFromC),
     mathCache(NULL)
 {
     JS_INIT_CLIST(&scripts);
@@ -601,3 +601,54 @@ JSCompartment::isAboutToBeCollected(JSGCInvocationKind gckind)
 {
     return !hold && (arenaListsAreEmpty() || gckind == GC_LAST_CONTEXT);
 }
+
+bool
+JSCompartment::haveScriptsOnStack(JSContext *cx)
+{
+    for (AllFramesIter i(cx); !i.done(); ++i) {
+        JSScript *script = i.fp()->maybeScript();
+        if (script && script->compartment == this)
+            return true;
+    }
+    return false;
+}
+
+bool
+JSCompartment::setDebugModeFromC(JSContext *cx, bool b)
+{
+    bool wasEnabled = debugMode();
+
+    // Debug mode can be enabled only when no scripts from the target
+    // compartment are on the stack. It would even be incorrect to discard just
+    // the non-live scripts' JITScripts because they might share ICs with live
+    // scripts (bug 632343).
+    if (b && !wasEnabled && haveScriptsOnStack(cx)) {
+        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_DEBUG_NOT_IDLE);
+        return false;
+    }
+
+    debugModeBits = (debugModeBits & ~uintN(DebugFromC)) | (b * DebugFromC);
+    if (b != wasEnabled)
+        updateForDebugMode(cx);
+    return true;
+}
+
+void
+JSCompartment::updateForDebugMode(JSContext *cx)
+{
+#ifdef JS_METHODJIT
+    bool mode = debugMode();
+
+    // Discard JIT code for any scripts that change debugMode. This assumes
+    // that 'comp' is in the same thread as 'cx'.
+    for (JSScript *script = (JSScript *) scripts.next;
+         &script->links != &scripts;
+         script = (JSScript *) script->links.next)
+    {
+        if (script->debugMode != mode) {
+            mjit::ReleaseScriptCode(cx, script);
+            script->debugMode = mode;
+        }
+    }
+#endif
+}
diff --git a/js/src/jscompartment.h b/js/src/jscompartment.h
index f307d18593f..93b82d4cda4 100644
--- a/js/src/jscompartment.h
+++ b/js/src/jscompartment.h
@@ -462,8 +462,11 @@ struct JS_FRIEND_API(JSCompartment) {
     const js::Shape              *initialRegExpShape;
     const js::Shape              *initialStringShape;
 
-    bool                         debugMode;  // true iff debug mode on
-    JSCList                      scripts;    // scripts in this compartment
+  private:
+    enum { DebugFromC = 1, DebugFromJS = 2 };
+    uintN                        debugModeBits;  // see debugMode() below
+  public:
+    JSCList                      scripts;        // scripts in this compartment
 
     js::NativeIterCache          nativeIterCache;
 
@@ -528,13 +531,52 @@ struct JS_FRIEND_API(JSCompartment) {
     size_t backEdgeCount(jsbytecode *pc) const;
     size_t incBackEdgeCount(jsbytecode *pc);
 
+    /*
+     * There are dueling APIs for debug mode. It can be enabled or disabled via
+     * JS_SetDebugModeForCompartment. It is automatically enabled and disabled
+     * by Debug objects. Therefore debugModeBits has the DebugFromC bit set if
+     * the C API wants debug mode and the DebugFromJS bit set if debuggees is
+     * nonempty.
+     */
+    bool debugMode() const { return !!debugModeBits; }
+
+    /*
+     * True if any scripts from this compartment are on the JS stack in the
+     * calling thread. cx is a context in the calling thread, and it is assumed
+     * that no other thread is using this compartment.
+     */
+    bool haveScriptsOnStack(JSContext *cx);
+
+    bool setDebugModeFromC(JSContext *cx, bool b);
+
+    /* This is called only when debugMode() has just toggled. */
+    void updateForDebugMode(JSContext *cx);
+
     js::GlobalObjectSet &getDebuggees() { return debuggees; }
-    bool addDebuggee(js::GlobalObject *global) {
-        JS_ASSERT(debugMode);
-        return !!debuggees.put(global);
+
+    bool addDebuggee(JSContext *cx, js::GlobalObject *global) {
+        bool wasEnabled = debugMode();
+        if (!wasEnabled && haveScriptsOnStack(cx)) {
+            JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_DEBUG_NOT_IDLE);
+            return false;
+        }
+        if (!debuggees.put(global)) {
+            js_ReportOutOfMemory(cx);
+            return false;
+        }
+        debugModeBits |= DebugFromJS;
+        if (!wasEnabled)
+            updateForDebugMode(cx);
+        return true;
     }
-    void removeDebuggee(js::GlobalObject *global) {
+
+    void removeDebuggee(JSContext *cx, js::GlobalObject *global) {
+        JS_ASSERT(debuggees.has(global));
         debuggees.remove(global);
+        if (debuggees.empty()) {
+            debugModeBits &= ~DebugFromJS;
+            updateForDebugMode(cx);
+        }
     }
 };
 
diff --git a/js/src/jsdbg.cpp b/js/src/jsdbg.cpp
index 7118b69d5de..7bb69f4ba8a 100644
--- a/js/src/jsdbg.cpp
+++ b/js/src/jsdbg.cpp
@@ -160,16 +160,10 @@ Debug::Debug(JSObject *dbg, JSObject *hooks)
 
 Debug::~Debug()
 {
-    JS_ASSERT(object->compartment()->rt->gcRunning);
-    if (!debuggees.empty()) {
-        // This happens only during per-compartment GC. See comment in
-        // Debug::sweepAll.
-        JS_ASSERT(object->compartment()->rt->gcCurrentCompartment == object->compartment());
-        for (GlobalObjectSet::Enum e(debuggees); !e.empty(); e.popFront())
-            removeDebuggeeGlobal(e.front(), NULL, &e);
-    }
+    JS_ASSERT(debuggees.empty());
 
     // This always happens in the GC thread, so no locking is required.
+    JS_ASSERT(object->compartment()->rt->gcRunning);
     JS_REMOVE_LINK(&link);
 }
 
@@ -616,8 +610,9 @@ Debug::trace(JSTracer *trc, JSObject *obj)
 }
 
 void
-Debug::sweepAll(JSRuntime *rt)
+Debug::sweepAll(JSContext *cx)
 {
+    JSRuntime *rt = cx->runtime;
     for (JSCList *p = &rt->debuggerList; (p = JS_NEXT_LINK(p)) != &rt->debuggerList;) {
         Debug *dbg = (Debug *) ((unsigned char *) p - offsetof(Debug, link));
 
@@ -636,47 +631,49 @@ Debug::sweepAll(JSRuntime *rt)
             // they are in different compartments), so in that case we just wait for
             // Debug::finalize.
             for (GlobalObjectSet::Enum e(dbg->debuggees); !e.empty(); e.popFront())
-                dbg->removeDebuggeeGlobal(e.front(), NULL, &e);
+                dbg->removeDebuggeeGlobal(cx, e.front(), NULL, &e);
         }
 
     }
 
     for (JSCompartment **c = rt->compartments.begin(); c != rt->compartments.end(); c++)
-        sweepCompartment(*c);
+        sweepCompartment(cx, *c);
 }
 
 void
-Debug::detachAllDebuggersFromGlobal(GlobalObject *global, GlobalObjectSet::Enum *compartmentEnum)
+Debug::detachAllDebuggersFromGlobal(JSContext *cx, GlobalObject *global, GlobalObjectSet::Enum *compartmentEnum)
 {
     const GlobalObject::DebugVector *debuggers = global->getDebuggers();
     JS_ASSERT(!debuggers->empty());
     while (!debuggers->empty())
-        debuggers->back()->removeDebuggeeGlobal(global, compartmentEnum, NULL);
+        debuggers->back()->removeDebuggeeGlobal(cx, global, compartmentEnum, NULL);
 }
 
 void
-Debug::sweepCompartment(JSCompartment *compartment)
+Debug::sweepCompartment(JSContext *cx, JSCompartment *compartment)
 {
     // For each debuggee being GC'd, detach it from all its debuggers.
     GlobalObjectSet &debuggees = compartment->getDebuggees();
     for (GlobalObjectSet::Enum e(debuggees); !e.empty(); e.popFront()) {
         GlobalObject *global = e.front();
         if (!global->isMarked())
-            detachAllDebuggersFromGlobal(global, &e);
+            detachAllDebuggersFromGlobal(cx, global, &e);
     }
 }
 
-void
-Debug::detachFromCompartment(JSCompartment *comp)
-{
-    for (GlobalObjectSet::Enum e(comp->getDebuggees()); !e.empty(); e.popFront())
-        detachAllDebuggersFromGlobal(e.front(), &e);
-}
-
 void
 Debug::finalize(JSContext *cx, JSObject *obj)
 {
     Debug *dbg = (Debug *) obj->getPrivate();
+    if (!dbg)
+        return;
+    if (!dbg->debuggees.empty()) {
+        // This happens only during per-compartment GC. See comment in
+        // Debug::sweepAll.
+        JS_ASSERT(cx->runtime->gcCurrentCompartment == dbg->object->compartment());
+        for (GlobalObjectSet::Enum e(dbg->debuggees); !e.empty(); e.popFront())
+            dbg->removeDebuggeeGlobal(cx, e.front(), NULL, &e);
+    }
     cx->delete_(dbg);
 }
 
@@ -822,7 +819,7 @@ Debug::removeDebuggee(JSContext *cx, uintN argc, Value *vp)
         return false;
     GlobalObject *global = referent->getGlobal();
     if (dbg->debuggees.has(global))
-        dbg->removeDebuggeeGlobal(global, NULL, NULL);
+        dbg->removeDebuggeeGlobal(cx, global, NULL, NULL);
     vp->setUndefined();
     return true;
 }
@@ -930,10 +927,7 @@ Debug::construct(JSContext *cx, uintN argc, Value *vp)
 bool
 Debug::addDebuggeeGlobal(JSContext *cx, GlobalObject *obj)
 {
-    if (!obj->compartment()->debugMode) {
-        JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_NEED_DEBUG_MODE);
-        return false;
-    }
+    JSCompartment *debuggeeCompartment = obj->compartment();
 
     // Check for cycles. If obj's compartment is reachable from this Debug
     // object's compartment by following debuggee-to-debugger links, then
@@ -942,10 +936,9 @@ Debug::addDebuggeeGlobal(JSContext *cx, GlobalObject *obj)
     Vector<JSCompartment *> visited(cx);
     if (!visited.append(object->compartment()))
         return false;
-    JSCompartment *dest = obj->compartment();
     for (size_t i = 0; i < visited.length(); i++) {
         JSCompartment *c = visited[i];
-        if (c == dest) {
+        if (c == debuggeeCompartment) {
             JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_DEBUG_LOOP);
             return false;
         }
@@ -963,12 +956,17 @@ Debug::addDebuggeeGlobal(JSContext *cx, GlobalObject *obj)
     }
 
     // Each debugger-debuggee relation must be stored in up to three places.
+    // JSCompartment::addDebuggee enables debug mode if needed.
     GlobalObject::DebugVector *v = obj->getOrCreateDebuggers(cx);
-    if (!v || !v->append(this))
+    if (!v || !v->append(this)) {
+        js_ReportOutOfMemory(cx);
         goto fail1;
-    if (!debuggees.put(obj))
+    }
+    if (!debuggees.put(obj)) {
+        js_ReportOutOfMemory(cx);
         goto fail2;
-    if (obj->getDebuggers()->length() == 1 && !obj->compartment()->addDebuggee(obj))
+    }
+    if (obj->getDebuggers()->length() == 1 && !debuggeeCompartment->addDebuggee(cx, obj))
         goto fail3;
     return true;
 
@@ -979,12 +977,12 @@ fail2:
     JS_ASSERT(v->back() == this);
     v->popBack();
 fail1:
-    js_ReportOutOfMemory(cx);
     return false;
 }
 
 void
-Debug::removeDebuggeeGlobal(GlobalObject *global, GlobalObjectSet::Enum *compartmentEnum,
+Debug::removeDebuggeeGlobal(JSContext *cx, GlobalObject *global,
+                            GlobalObjectSet::Enum *compartmentEnum,
                             GlobalObjectSet::Enum *debugEnum)
 {
     // Each debuggee is in two HashSets: one for its compartment and one for
@@ -1026,7 +1024,7 @@ Debug::removeDebuggeeGlobal(GlobalObject *global, GlobalObjectSet::Enum *compart
         if (compartmentEnum)
             compartmentEnum->removeFront();
         else
-            global->compartment()->removeDebuggee(global);
+            global->compartment()->removeDebuggee(cx, global);
     }
     if (debugEnum)
         debugEnum->removeFront();
diff --git a/js/src/jsdbg.h b/js/src/jsdbg.h
index 9761fdb986a..d08be9adf98 100644
--- a/js/src/jsdbg.h
+++ b/js/src/jsdbg.h
@@ -83,7 +83,8 @@ class Debug {
     ObjectMap objects;
 
     bool addDebuggeeGlobal(JSContext *cx, GlobalObject *obj);
-    void removeDebuggeeGlobal(GlobalObject *global, GlobalObjectSet::Enum *compartmentEnum,
+    void removeDebuggeeGlobal(JSContext *cx, GlobalObject *global,
+                              GlobalObjectSet::Enum *compartmentEnum,
                               GlobalObjectSet::Enum *debugEnum);
 
     JSTrapStatus handleUncaughtException(AutoCompartment &ac, Value *vp, bool callHook);
@@ -134,7 +135,6 @@ class Debug {
     inline JSObject *toJSObject() const;
     static inline Debug *fromJSObject(JSObject *obj);
     static Debug *fromChildJSObject(JSObject *obj);
-    static void detachFromCompartment(JSCompartment *comp);
 
     /*********************************** Methods for interaction with the GC. */
 
@@ -153,9 +153,9 @@ class Debug {
     // returns true. If not, it returns false.
     //
     static bool mark(GCMarker *trc, JSCompartment *compartment, JSGCInvocationKind gckind);
-    static void sweepAll(JSRuntime *rt);
-    static void sweepCompartment(JSCompartment *compartment);
-    static void detachAllDebuggersFromGlobal(GlobalObject *global,
+    static void sweepAll(JSContext *cx);
+    static void sweepCompartment(JSContext *cx, JSCompartment *compartment);
+    static void detachAllDebuggersFromGlobal(JSContext *cx, GlobalObject *global,
                                              GlobalObjectSet::Enum *compartmentEnum);
 
     static inline void leaveStackFrame(JSContext *cx);
diff --git a/js/src/jsdbgapi.cpp b/js/src/jsdbgapi.cpp
index d4db795301a..de6673137d1 100644
--- a/js/src/jsdbgapi.cpp
+++ b/js/src/jsdbgapi.cpp
@@ -101,7 +101,7 @@ typedef struct JSTrap {
 JS_PUBLIC_API(JSBool)
 JS_GetDebugMode(JSContext *cx)
 {
-    return cx->compartment->debugMode;
+    return cx->compartment->debugMode();
 }
 
 JS_PUBLIC_API(JSBool)
@@ -113,7 +113,7 @@ JS_SetDebugMode(JSContext *cx, JSBool debug)
 JS_PUBLIC_API(void)
 JS_SetRuntimeDebugMode(JSRuntime *rt, JSBool debug)
 {
-    rt->debugMode = debug;
+    rt->debugMode = !!debug;
 }
 
 namespace js {
@@ -159,60 +159,7 @@ ScriptDebugEpilogue(JSContext *cx, StackFrame *fp, bool okArg)
 JS_FRIEND_API(JSBool)
 JS_SetDebugModeForCompartment(JSContext *cx, JSCompartment *comp, JSBool debug)
 {
-    if (comp->debugMode == !!debug)
-        return JS_TRUE;
-
-    if (debug) {
-        // This should only be called when no scripts are live. It would even
-        // be incorrect to discard just the non-live scripts' JITScripts
-        // because they might share ICs with live scripts (bug 632343).
-        for (AllFramesIter i(cx); !i.done(); ++i) {
-            JSScript *script = i.fp()->maybeScript();
-            if (script && script->compartment == comp) {
-                JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_DEBUG_NOT_IDLE);
-                return false;
-            }
-        }
-    }
-
-    // All scripts compiled from this point on should be in the requested debugMode.
-    comp->debugMode = !!debug;
-
-    // Detach any debuggers attached to this compartment.
-    if (debug)
-        JS_ASSERT(comp->getDebuggees().empty());
-    else
-        Debug::detachFromCompartment(comp);
-
-    // Discard JIT code for any scripts that change debugMode. This function
-    // assumes that 'comp' is in the same thread as 'cx'.
-#ifdef JS_METHODJIT
-    JS::AutoEnterScriptCompartment ac;
-
-    for (JSScript *script = (JSScript *)comp->scripts.next;
-         &script->links != &comp->scripts;
-         script = (JSScript *)script->links.next)
-    {
-        if (!script->debugMode == !debug)
-            continue;
-
-        /*
-         * If compartment entry fails, debug mode is left partially on, leading
-         * to a small performance overhead but no loss of correctness. We set
-         * the debug flags to false so that the caller will not later attempt
-         * to use debugging features.
-         */
-        if (!ac.entered() && !ac.enter(cx, script)) {
-            comp->debugMode = JS_FALSE;
-            return JS_FALSE;
-        }
-
-        mjit::ReleaseScriptCode(cx, script);
-        script->debugMode = !!debug;
-    }
-#endif
-
-    return JS_TRUE;
+    return comp->setDebugModeFromC(cx, !!debug);
 }
 
 JS_FRIEND_API(JSBool)
@@ -225,7 +172,7 @@ js_SetSingleStepMode(JSContext *cx, JSScript *script, JSBool singleStep)
         return JS_TRUE;
 #endif
 
-    JS_ASSERT_IF(singleStep, cx->compartment->debugMode);
+    JS_ASSERT_IF(singleStep, cx->compartment->debugMode());
 
 #ifdef JS_METHODJIT
     /* request the next recompile to inject single step interrupts */
diff --git a/js/src/jsgc.cpp b/js/src/jsgc.cpp
index ec916ea3f31..7240a2bb93e 100644
--- a/js/src/jsgc.cpp
+++ b/js/src/jsgc.cpp
@@ -2369,7 +2369,7 @@ MarkAndSweep(JSContext *cx, JSCompartment *comp, JSGCInvocationKind gckind GCTIM
     js_SweepWatchPoints(cx);
 
     if (!comp)
-        Debug::sweepAll(rt);
+        Debug::sweepAll(cx);
 
     /*
      * We finalize objects before other GC things to ensure that object's finalizer
diff --git a/js/src/jsinterpinlines.h b/js/src/jsinterpinlines.h
index 9b1ec580afe..99f432c4a28 100644
--- a/js/src/jsinterpinlines.h
+++ b/js/src/jsinterpinlines.h
@@ -353,7 +353,7 @@ ScriptPrologue(JSContext *cx, StackFrame *fp)
         fp->functionThis().setObject(*obj);
     }
 
-    if (cx->compartment->debugMode)
+    if (cx->compartment->debugMode())
         ScriptDebugPrologue(cx, fp);
     return true;
 }
@@ -361,7 +361,7 @@ ScriptPrologue(JSContext *cx, StackFrame *fp)
 inline bool
 ScriptEpilogue(JSContext *cx, StackFrame *fp, bool ok)
 {
-    if (cx->compartment->debugMode)
+    if (cx->compartment->debugMode())
         ok = ScriptDebugEpilogue(cx, fp, ok);
 
     /*
@@ -382,7 +382,7 @@ ScriptPrologueOrGeneratorResume(JSContext *cx, StackFrame *fp)
 {
     if (!fp->isGeneratorFrame())
         return ScriptPrologue(cx, fp);
-    if (cx->compartment->debugMode)
+    if (cx->compartment->debugMode())
         ScriptDebugPrologue(cx, fp);
     return true;
 }
@@ -392,7 +392,7 @@ ScriptEpilogueOrGeneratorYield(JSContext *cx, StackFrame *fp, bool ok)
 {
     if (!fp->isYielding())
         return ScriptEpilogue(cx, fp, ok);
-    if (cx->compartment->debugMode)
+    if (cx->compartment->debugMode())
         return ScriptDebugEpilogue(cx, fp, ok);
     return ok;
 }
diff --git a/js/src/methodjit/Compiler.cpp b/js/src/methodjit/Compiler.cpp
index 0db553b77d7..97a7a453c56 100644
--- a/js/src/methodjit/Compiler.cpp
+++ b/js/src/methodjit/Compiler.cpp
@@ -114,7 +114,7 @@ mjit::Compiler::Compiler(JSContext *cx, StackFrame *fp)
     jumpTables(CompilerAllocPolicy(cx, *thisFromCtor())),
     jumpTableOffsets(CompilerAllocPolicy(cx, *thisFromCtor())),
     stubcc(cx, *thisFromCtor(), frame, script),
-    debugMode_(cx->compartment->debugMode),
+    debugMode_(cx->compartment->debugMode()),
 #if defined JS_TRACER
     addTraceHints(cx->traceJitEnabled),
 #endif
diff --git a/js/src/methodjit/FrameState.cpp b/js/src/methodjit/FrameState.cpp
index 933e95c35b6..0f890361343 100644
--- a/js/src/methodjit/FrameState.cpp
+++ b/js/src/methodjit/FrameState.cpp
@@ -80,7 +80,7 @@ FrameState::init()
         return false;
 #endif
 
-    eval = script->usesEval || cx->compartment->debugMode;
+    eval = script->usesEval || cx->compartment->debugMode();
 
     size_t totalBytes = sizeof(FrameEntry) * nentries +                     // entries[], w/ callee+this
                         sizeof(FrameEntry *) * nentries +                   // tracker.entries
diff --git a/js/src/methodjit/Retcon.cpp b/js/src/methodjit/Retcon.cpp
index 05dd2e1e07e..8f370fdd3b8 100644
--- a/js/src/methodjit/Retcon.cpp
+++ b/js/src/methodjit/Retcon.cpp
@@ -202,7 +202,7 @@ Recompiler::recompile(StackFrame *fp, Vector<PatchableAddress> &patches,
                       Vector<CallSite> &sites)
 {
     /* If we get this far, the script is live, and we better be safe to re-jit. */
-    JS_ASSERT(cx->compartment->debugMode);
+    JS_ASSERT(cx->compartment->debugMode());
     JS_ASSERT(fp);
 
     Compiler c(cx, fp);
diff --git a/js/src/vm/GlobalObject.cpp b/js/src/vm/GlobalObject.cpp
index df7cda6b467..aac866a11d0 100644
--- a/js/src/vm/GlobalObject.cpp
+++ b/js/src/vm/GlobalObject.cpp
@@ -253,10 +253,10 @@ GlobalObject::addDebug(JSContext *cx, Debug *dbg)
     for (Debug **p = vec->begin(); p != vec->end(); p++)
         JS_ASSERT(*p != dbg);
 #endif
-    if (vec->empty() && !compartment()->addDebuggee(this))
+    if (vec->empty() && !compartment()->addDebuggee(cx, this))
         return false;
     if (!vec->append(dbg)) {
-        compartment()->removeDebuggee(this);
+        compartment()->removeDebuggee(cx, this);
         return false;
     }
     return true;