Add Debug.Frame.prototype.older.

js/src/jit-test/tests/debug/Frame-identity-03.js

@@ -0,0 +1,52 @@
+// |jit-test| debug
+// Test that we create new Debug.Frames and reuse old ones correctly with recursion.
+
+var g = newGlobal('new-compartment');
+g.debuggeeGlobal = this;
+g.eval("(" + function () {
+        function id(f) {
+            return ("id" in f) ? f.id : (f.id = nextid++);
+        }
+
+        var dbg = new Debug(debuggeeGlobal);
+        dbg.hooks = {
+            debuggerHandler: function (frame) {
+                var a = [];
+                for (; frame; frame = frame.older)
+                    a.push(frame);
+                var s = '';
+                while (a.length)
+                    s += id(a.pop());
+                results.push(s);
+            }
+        };
+    } + ")();");
+
+function cons(a, b) {
+    debugger;
+    return [a, b];
+}
+
+function tree(n) {
+    if (n < 2)
+        return n;
+    return cons(tree(n - 1), tree(n - 2));
+}
+
+g.eval("results = []; nextid = 0;");
+debugger;
+assertEq(g.results.join(","), "0");
+assertEq(g.nextid, 1);
+
+g.eval("results = [];");
+tree(2);
+assertEq(g.results.join(","), "012"); // 0=global, 1=tree, 2=cons
+
+g.eval("results = []; nextid = 1;");
+tree(3);
+assertEq(g.results.join(","), "0123,014"); //0=global, 1=tree(3), 2=tree(2), 3=cons, 4=cons
+
+g.eval("results = []; nextid = 1;");
+tree(4);
+// 0=global, 1=tree(4), 2=tree(3), 3=tree(2), 4=cons, tree(1), 5=cons, 6=tree(2), 7=cons, 8=cons
+assertEq(g.results.join(","), "01234,0125,0167,018");

js/src/jit-test/tests/debug/Frame-older-01.js

@@ -0,0 +1,25 @@
+// |jit-test| debug
+// 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(", ");
+            }
+        };
+    } + ")();");
+
+function first() { return second(); }
+function second() { return eval("third()"); }
+function third() { debugger; }
+first();
+assertEq(g.result, "global, first, second, eval, third");

js/src/jsdbg.cpp

@@ -149,9 +149,22 @@ Debug::init()
     return frames.init() && objects.init();
 }
 
+JS_STATIC_ASSERT(uintN(JSSLOT_DEBUGFRAME_OWNER) == uintN(JSSLOT_DEBUGOBJECT_OWNER));
+
+Debug *
+Debug::fromChildJSObject(JSObject *obj)
+{
+    JS_ASSERT(obj->clasp == &DebugFrame_class ||
+              obj->clasp == &DebugObject_class ||
+              obj->clasp == &DebugFunction_class);
+    JSObject *dbgobj = &obj->getReservedSlot(JSSLOT_DEBUGOBJECT_OWNER).toObject();
+    return fromJSObject(dbgobj);
+}
+
 bool
 Debug::getScriptFrame(JSContext *cx, StackFrame *fp, Value *vp)
 {
+    JS_ASSERT(fp->isScriptFrame());
     FrameMap::AddPtr p = frames.lookupForAdd(fp);
     if (!p) {
         // Create script frame. First copy the arguments.
@@ -734,28 +747,12 @@ DebugFrame_getType(JSContext *cx, uintN argc, Value *vp)
     return true;
 }
 
-JS_STATIC_ASSERT(uintN(JSSLOT_DEBUGFRAME_OWNER) == uintN(JSSLOT_DEBUGOBJECT_OWNER));
-
-static JSBool
-DebugChild_wrapDebuggeeValue(JSContext *cx, JSObject *frameobj, Value *vp)
-{
-    // This uses JSSLOT_DEBUGOBJECT_OWNER, but it will work for any object that
-    // has a pointer to the owning Debug object in reserved slot 0.
-    JSObject *dbgobj = &frameobj->getReservedSlot(JSSLOT_DEBUGOBJECT_OWNER).toObject();
-    Debug *dbg = Debug::fromJSObject(dbgobj);
-    if (!dbg->wrapDebuggeeValue(cx, vp)) {
-        vp->setUndefined();
-        return false;
-    }
-    return true;
-}
-
 static JSBool
 DebugFrame_getCallee(JSContext *cx, uintN argc, Value *vp)
 {
     THIS_FRAME(cx, vp, "get callee", thisobj, fp);
     *vp = (fp->isFunctionFrame() && !fp->isEvalFrame()) ? fp->calleev() : NullValue();
-    return DebugChild_wrapDebuggeeValue(cx, thisobj, vp);
+    return Debug::fromChildJSObject(thisobj)->wrapDebuggeeValue(cx, vp);
 }
 
 static JSBool
@@ -779,7 +776,19 @@ DebugFrame_getThis(JSContext *cx, uintN argc, Value *vp)
         *vp = fp->thisValue();
         ac.leave();
     }
-    return DebugChild_wrapDebuggeeValue(cx, thisobj, vp);
+    return Debug::fromChildJSObject(thisobj)->wrapDebuggeeValue(cx, vp);
+}
+
+static JSBool
+DebugFrame_getOlder(JSContext *cx, uintN argc, Value *vp)
+{
+    THIS_FRAME(cx, vp, "get this", thisobj, thisfp);
+    for (StackFrame *fp = thisfp->prev(); fp; fp = fp->prev()) {
+        if (!fp->isDummyFrame())
+            return Debug::fromChildJSObject(thisobj)->getScriptFrame(cx, fp, vp);
+    }
+    vp->setNull();
+    return true;
 }
 
 JSBool
@@ -811,11 +820,12 @@ DebugFrame_construct(JSContext *cx, uintN argc, Value *vp)
 
 static JSPropertySpec DebugFrame_properties[] = {
     JS_PSG("type", DebugFrame_getType, 0),
+    JS_PSG("this", DebugFrame_getThis, 0),
+    JS_PSG("older", DebugFrame_getOlder, 0),
+    JS_PSG("live", DebugFrame_getLive, 0),
     JS_PSG("callee", DebugFrame_getCallee, 0),
     JS_PSG("generator", DebugFrame_getGenerator, 0),
-    JS_PSG("this", DebugFrame_getThis, 0),
     JS_PSG("arguments", DebugFrame_getArguments, 0),
-    JS_PSG("live", DebugFrame_getLive, 0),
     JS_PS_END
 };
 
@@ -922,7 +932,7 @@ DebugFunction_getName(JSContext *cx, uintN argc, Value *vp)
     THIS_DEBUGFUNCTION_REFERENT(cx, vp, "get name", funobj);
     if (JSString *name = funobj->getFunctionPrivate()->atom) {
         vp->setString(name);
-        return DebugChild_wrapDebuggeeValue(cx, &vp[1].toObject(), vp);
+        return Debug::fromChildJSObject(&vp[1].toObject())->wrapDebuggeeValue(cx, vp);
     }
     vp->setNull();
     return true;

js/src/jsdbg.h

@@ -92,7 +92,6 @@ class Debug {
 
     inline bool hasAnyLiveHooks() const;
 
-    bool getScriptFrame(JSContext *cx, StackFrame *fp, Value *vp);
     static void slowPathLeaveStackFrame(JSContext *cx);
 
     inline bool observesDebuggerStatement() const;
@@ -104,8 +103,10 @@ class Debug {
     bool init();
     inline JSObject *toJSObject() const;
     static inline Debug *fromJSObject(JSObject *obj);
+    static Debug *fromChildJSObject(JSObject *obj);
+
+    /*********************************** Methods for interaction with the GC. */
 
-    // Methods for interaction with the GC.
     //
     // A Debug object is live if:
     //   * the Debug JSObject is live (Debug::trace handles this case); OR
@@ -131,6 +132,8 @@ class Debug {
     static inline void leaveStackFrame(JSContext *cx);
     static inline JSTrapStatus onDebuggerStatement(JSContext *cx, js::Value *vp);
 
+    /**************************************** Functions for use by jsdbg.cpp. */
+
     // Precondition: *vp is a value from a debuggee compartment and cx is in
     // the debugger's compartment.
     //
@@ -151,6 +154,8 @@ class Debug {
     //
     bool unwrapDebuggeeValue(JSContext *cx, Value *vp);
 
+    // Store the Debug.Frame object for the frame fp in *vp.
+    bool getScriptFrame(JSContext *cx, StackFrame *fp, Value *vp);
 };
 
 bool