1 files changed, 83 insertions, 16 deletions

diff --git a/js/src/jit/JitFrames.cpp b/js/src/jit/JitFrames.cpp
index 646442b4c..966d952d3 100644
--- a/js/src/jit/JitFrames.cpp
+++ b/js/src/jit/JitFrames.cpp
@@ -328,23 +328,46 @@ NumArgAndLocalSlots(const InlineFrameIterator& frame)
 }
 
 static void
-CloseLiveIteratorIon(JSContext* cx, const InlineFrameIterator& frame, uint32_t stackSlot)
+CloseLiveIteratorIon(JSContext* cx, const InlineFrameIterator& frame, JSTryNote* tn)
 {
+    MOZ_ASSERT(tn->kind == JSTRY_FOR_IN ||
+               tn->kind == JSTRY_DESTRUCTURING_ITERCLOSE);
+
+    bool isDestructuring = tn->kind == JSTRY_DESTRUCTURING_ITERCLOSE;
+    MOZ_ASSERT_IF(!isDestructuring, tn->stackDepth > 0);
+    MOZ_ASSERT_IF(isDestructuring, tn->stackDepth > 1);
+
     SnapshotIterator si = frame.snapshotIterator();
 
-    // Skip stack slots until we reach the iterator object.
-    uint32_t skipSlots = NumArgAndLocalSlots(frame) + stackSlot - 1;
+    // Skip stack slots until we reach the iterator object on the stack. For
+    // the destructuring case, we also need to get the "done" value.
+    uint32_t stackSlot = tn->stackDepth;
+    uint32_t adjust = isDestructuring ? 2 : 1;
+    uint32_t skipSlots = NumArgAndLocalSlots(frame) + stackSlot - adjust;
 
     for (unsigned i = 0; i < skipSlots; i++)
         si.skip();
 
     Value v = si.read();
-    RootedObject obj(cx, &v.toObject());
+    RootedObject iterObject(cx, &v.toObject());
+
+    if (isDestructuring) {
+        RootedValue doneValue(cx, si.read());
+        bool done = ToBoolean(doneValue);
+        // Do not call IteratorClose if the destructuring iterator is already
+        // done.
+        if (done)
+            return;
+    }
 
-    if (cx->isExceptionPending())
-        UnwindIteratorForException(cx, obj);
-    else
-        UnwindIteratorForUncatchableException(cx, obj);
+    if (cx->isExceptionPending()) {
+        if (tn->kind == JSTRY_FOR_IN)
+            UnwindIteratorForException(cx, iterObject);
+        else
+            IteratorCloseForException(cx, iterObject);
+    } else {
+        UnwindIteratorForUncatchableException(cx, iterObject);
+    }
 }
 
 class IonFrameStackDepthOp
@@ -413,25 +436,36 @@ HandleExceptionIon(JSContext* cx, const InlineFrameIterator& frame, ResumeFromEx
     if (!script->hasTrynotes())
         return;
 
+    bool inForOfIterClose = false;
+
     for (TryNoteIterIon tni(cx, frame); !tni.done(); ++tni) {
         JSTryNote* tn = *tni;
 
         switch (tn->kind) {
-          case JSTRY_FOR_IN: {
-            MOZ_ASSERT(JSOp(*(script->main() + tn->start + tn->length)) == JSOP_ENDITER);
-            MOZ_ASSERT(tn->stackDepth > 0);
+          case JSTRY_FOR_IN:
+          case JSTRY_DESTRUCTURING_ITERCLOSE:
+            MOZ_ASSERT_IF(tn->kind == JSTRY_FOR_IN,
+                          JSOp(*(script->main() + tn->start + tn->length)) == JSOP_ENDITER);
+            CloseLiveIteratorIon(cx, frame, tn);
+            break;
 
-            uint32_t localSlot = tn->stackDepth;
-            CloseLiveIteratorIon(cx, frame, localSlot);
+          case JSTRY_FOR_OF_ITERCLOSE:
+            inForOfIterClose = true;
             break;
-          }
 
           case JSTRY_FOR_OF:
+            inForOfIterClose = false;
+            break;
+
           case JSTRY_LOOP:
             break;
 
           case JSTRY_CATCH:
             if (cx->isExceptionPending()) {
+                // See corresponding comment in ProcessTryNotes.
+                if (inForOfIterClose)
+                    break;
+
                 // Ion can compile try-catch, but bailing out to catch
                 // exceptions is slow. Reset the warm-up counter so that if we
                 // catch many exceptions we won't Ion-compile the script.
@@ -562,6 +596,7 @@ ProcessTryNotesBaseline(JSContext* cx, const JitFrameIterator& frame, Environmen
                         ResumeFromException* rfe, jsbytecode** pc)
 {
     RootedScript script(cx, frame.baselineFrame()->script());
+    bool inForOfIterClose = false;
 
     for (TryNoteIterBaseline tni(cx, frame.baselineFrame(), *pc); !tni.done(); ++tni) {
         JSTryNote* tn = *tni;
@@ -572,7 +607,11 @@ ProcessTryNotesBaseline(JSContext* cx, const JitFrameIterator& frame, Environmen
             // If we're closing a legacy generator, we have to skip catch
             // blocks.
             if (cx->isClosingGenerator())
-                continue;
+                break;
+
+            // See corresponding comment in ProcessTryNotes.
+            if (inForOfIterClose)
+                break;
 
             SettleOnTryNote(cx, tn, frame, ei, rfe, pc);
 
@@ -588,6 +627,10 @@ ProcessTryNotesBaseline(JSContext* cx, const JitFrameIterator& frame, Environmen
           }
 
           case JSTRY_FINALLY: {
+            // See corresponding comment in ProcessTryNotes.
+            if (inForOfIterClose)
+                break;
+
             SettleOnTryNote(cx, tn, frame, ei, rfe, pc);
             rfe->kind = ResumeFromException::RESUME_FINALLY;
             rfe->target = script->baselineScript()->nativeCodeForPC(script, *pc);
@@ -602,7 +645,7 @@ ProcessTryNotesBaseline(JSContext* cx, const JitFrameIterator& frame, Environmen
             uint8_t* framePointer;
             uint8_t* stackPointer;
             BaselineFrameAndStackPointersFromTryNote(tn, frame, &framePointer, &stackPointer);
-            Value iterValue(*(Value*) stackPointer);
+            Value iterValue(*reinterpret_cast<Value*>(stackPointer));
             RootedObject iterObject(cx, &iterValue.toObject());
             if (!UnwindIteratorForException(cx, iterObject)) {
                 // See comment in the JSTRY_FOR_IN case in Interpreter.cpp's
@@ -614,7 +657,31 @@ ProcessTryNotesBaseline(JSContext* cx, const JitFrameIterator& frame, Environmen
             break;
           }
 
+          case JSTRY_DESTRUCTURING_ITERCLOSE: {
+            uint8_t* framePointer;
+            uint8_t* stackPointer;
+            BaselineFrameAndStackPointersFromTryNote(tn, frame, &framePointer, &stackPointer);
+            RootedValue doneValue(cx, *(reinterpret_cast<Value*>(stackPointer)));
+            bool done = ToBoolean(doneValue);
+            if (!done) {
+                Value iterValue(*(reinterpret_cast<Value*>(stackPointer) + 1));
+                RootedObject iterObject(cx, &iterValue.toObject());
+                if (!IteratorCloseForException(cx, iterObject)) {
+                    SettleOnTryNote(cx, tn, frame, ei, rfe, pc);
+                    return false;
+                }
+            }
+            break;
+          }
+
+          case JSTRY_FOR_OF_ITERCLOSE:
+            inForOfIterClose = true;
+            break;
+
           case JSTRY_FOR_OF:
+            inForOfIterClose = false;
+            break;
+
           case JSTRY_LOOP:
             break;