Bug 749697 - Support debugging when multiple JSContexts are on the stack. Part 2, fix evcross-context eval-in-frame. r=luke.

--HG--
extra : rebase_source : 216bdac31ec88af4130ffd9ffac9bf0ebb1a9b39

js/src/jit-test/tests/debug/cross-context-1.js

@@ -0,0 +1,20 @@
+// frame.eval can evaluate code in a frame pushed in another context. Bug 749697.
+
+// In other words, the debugger can see all frames on the stack, even though
+// each frame is attached to a particular JSContext and multiple JSContexts may
+// have frames on the stack.
+
+var g = newGlobal('new-compartment');
+g.eval('function f(a) { debugger; evaluate("debugger;", {newContext: true}); }');
+
+var dbg = new Debugger(g);
+var hits = 0;
+dbg.onDebuggerStatement = function (frame1) {
+    dbg.onDebuggerStatement = function (frame2) {
+        assertEq(frame1.eval("a").return, 31);
+        hits++;
+    };
+};
+
+g.f(31);
+assertEq(hits, 1);

js/src/jit-test/tests/debug/cross-context-2.js

@@ -0,0 +1,32 @@
+// The debugger can eval in any frame in the stack even if every frame was
+// pushed in a different context.
+
+var g = newGlobal('new-compartment');
+g.eval('function f(a) {\n' +
+       '    if (a == 1)\n' +
+       '        debugger;\n' +
+       '    else\n' +
+       '        evaluate("f(" + a + " - 1);", {newContext: true});\n' +
+       '}\n');
+var N = 9;
+
+var dbg = new Debugger(g);
+var frames = [];
+var hits = 0;
+dbg.onEnterFrame = function (frame) {
+    if (frame.type == "call" && frame.callee.name == "f") {
+        frames.push(frame);
+        frame.onPop = function () { assertEq(frames.pop(), frame); };
+    }
+};
+dbg.onDebuggerStatement = function (frame) {
+    assertEq(frames.length, N);
+    var i = N;
+    for (var f of frames)
+        assertEq(f.eval('a').return, i--);
+    hits++;
+};
+
+g.f(N);
+assertEq(hits, 1);
+assertEq(frames.length, 0);

js/src/vm/Stack.cpp

@@ -822,7 +822,8 @@ ContextStack::pushExecuteFrame(JSContext *cx, JSScript *script, const Value &thi
     MaybeExtend extend;
     if (evalInFrame) {
         /* Though the prev-frame is given, need to search for prev-call. */
-        StackIter iter(cx, StackIter::GO_THROUGH_SAVED);
+        StackSegment &seg = cx->stack.space().containingSegment(evalInFrame);
+        StackIter iter(cx->runtime, seg);
         while (!iter.isScript() || iter.fp() != evalInFrame)
             ++iter;
         evalInFrameCalls = iter.calls_;
@@ -1167,8 +1168,8 @@ StackIter::settleOnNewState()
             if (op == JSOP_CALL || op == JSOP_FUNCALL) {
                 unsigned argc = GET_ARGC(pc_);
                 DebugOnly<unsigned> spoff = sp_ - fp_->base();
-                JS_ASSERT_IF(cx_->stackIterAssertionEnabled,
-                             spoff == js_ReconstructStackDepth(cx_, fp_->script(), pc_));
+                JS_ASSERT_IF(maybecx_ && maybecx_->stackIterAssertionEnabled,
+                             spoff == js_ReconstructStackDepth(maybecx_, fp_->script(), pc_));
                 Value *vp = sp_ - (2 + argc);
 
                 CrashIfInvalidSlot(fp_, vp);
@@ -1217,7 +1218,7 @@ StackIter::settleOnNewState()
 }
 
 StackIter::StackIter(JSContext *cx, SavedOption savedOption)
-  : cx_(cx),
+  : maybecx_(cx),
     savedOption_(savedOption)
 {
 #ifdef JS_METHODJIT
@@ -1234,6 +1235,18 @@ StackIter::StackIter(JSContext *cx, SavedOption savedOption)
     }
 }
 
+StackIter::StackIter(JSRuntime *rt, StackSegment &seg)
+  : maybecx_(NULL), savedOption_(STOP_AT_SAVED)
+{
+#ifdef JS_METHODJIT
+    CompartmentVector &v = rt->compartments;
+    for (size_t i = 0; i < v.length(); i++)
+        mjit::ExpandInlineFrames(v[i]);
+#endif
+    startOnSegment(&seg);
+    settleOnNewState();
+}
+
 StackIter &
 StackIter::operator++()
 {

js/src/vm/Stack.h

@@ -1819,7 +1819,7 @@ class GeneratorFrameGuard : public FrameGuard
 class StackIter
 {
     friend class ContextStack;
-    JSContext    *cx_;
+    JSContext    *maybecx_;
   public:
     enum SavedOption { STOP_AT_SAVED, GO_THROUGH_SAVED };
   private:
@@ -1846,6 +1846,7 @@ class StackIter
 
   public:
     StackIter(JSContext *cx, SavedOption = STOP_AT_SAVED);
+    StackIter(JSRuntime *rt, StackSegment &seg);
 
     bool done() const { return state_ == DONE; }
     StackIter &operator++();