Bug 1147371: Convert self-hosted code that need to call IteratorClose to use for-of

Issue #74

7 files changed, 27 insertions, 192 deletions

diff --git a/js/src/builtin/Array.js b/js/src/builtin/Array.js
index 5ab0b71be5..45f90a7b80 100644
--- a/js/src/builtin/Array.js
+++ b/js/src/builtin/Array.js
@@ -803,54 +803,32 @@ function ArrayFrom(items, mapfn=undefined, thisArg=undefined) {
         // Steps 5.a-c.
         var A = IsConstructor(C) ? new C() : [];
 
-        // Step 5.c.
-        var iterator = GetIterator(items, usingIterator);
-
         // Step 5.d.
         var k = 0;
 
-        // Step 5.e.
-        // These steps cannot be implemented using a for-of loop.
-        // See <https://bugs.ecmascript.org/show_bug.cgi?id=2883>.
-        while (true) {
+        // Step 5.c, 5.e.
+        var iteratorWrapper = { [std_iterator]() { return GetIterator(items, usingIterator); } };
+        for (var nextValue of allowContentIter(iteratorWrapper)) {
             // Step 5.e.i.
             // Disabled for performance reason.  We won't hit this case on
             // normal array, since _DefineDataProperty will throw before it.
             // We could hit this when |A| is a proxy and it ignores
             // |_DefineDataProperty|, but it happens only after too long loop.
             /*
-            if (k >= 0x1fffffffffffff) {
-                IteratorCloseThrow(iterator);
+            if (k >= 0x1fffffffffffff)
                 ThrowTypeError(JSMSG_TOO_LONG_ARRAY);
-            }
             */
 
-            // Step 5.e.iii.
-            var next = callContentFunction(iterator.next, iterator);
-            if (!IsObject(next))
-                ThrowTypeError(JSMSG_NEXT_RETURNED_PRIMITIVE);
-
-            // Step 5.e.iv.
-            if (next.done) {
-                A.length = k;
-                return A;
-            }
-
-            // Steps 5.e.v.
-            var nextValue = next.value;
-
             // Steps 5.e.vi-vii.
-            try {
-                var mappedValue = mapping ? callContentFunction(mapfn, thisArg, nextValue, k) : nextValue;
-
-                // Steps 5.e.ii (reordered), 5.e.viii.
-                _DefineDataProperty(A, k++, mappedValue);
-            } catch (e) {
-                // Steps 5.e.vi.2, 5.e.ix.
-                IteratorCloseThrow(iterator);
-                throw e;
-            }
+            var mappedValue = mapping ? callContentFunction(mapfn, thisArg, nextValue, k) : nextValue;
+
+            // Steps 5.e.ii (reordered), 5.e.viii.
+            _DefineDataProperty(A, k++, mappedValue);
         }
+
+        // Step 5.e.iv.
+        A.length = k;
+        return A;
     }
 
     // Step 7.
diff --git a/js/src/builtin/Classes.js b/js/src/builtin/Classes.js
index d0f20b5fd7..24841d605e 100644
--- a/js/src/builtin/Classes.js
+++ b/js/src/builtin/Classes.js
@@ -5,7 +5,7 @@
 var DefaultDerivedClassConstructor =
     class extends null {
         constructor(...args) {
-            super(...allowContentSpread(args));
+            super(...allowContentIter(args));
         }
     };
 MakeDefaultConstructor(DefaultDerivedClassConstructor);
diff --git a/js/src/builtin/Map.js b/js/src/builtin/Map.js
index 27a12bfff8..580629a132 100644
--- a/js/src/builtin/Map.js
+++ b/js/src/builtin/Map.js
@@ -14,44 +14,14 @@ function MapConstructorInit(iterable) {
     if (!IsCallable(adder))
         ThrowTypeError(JSMSG_NOT_FUNCTION, typeof adder);
 
-    // Step 6.c.
-    var iterFn = iterable[std_iterator];
-    if (!IsCallable(iterFn))
-        ThrowTypeError(JSMSG_NOT_ITERABLE, DecompileArg(0, iterable));
-
-    var iter = callContentFunction(iterFn, iterable);
-    if (!IsObject(iter))
-        ThrowTypeError(JSMSG_NOT_NONNULL_OBJECT, typeof iter);
-
-    // Step 7 (not applicable).
-
-    // Step 8.
-    while (true) {
-        // Step 8.a.
-        var next = callContentFunction(iter.next, iter);
-        if (!IsObject(next))
-            ThrowTypeError(JSMSG_NOT_NONNULL_OBJECT, typeof next);
-
-        // Step 8.b.
-        if (next.done)
-            return;
-
-        // Step 8.c.
-        var nextItem = next.value;
-
+    // Steps 6.c-8.
+    for (var nextItem of allowContentIter(iterable)) {
         // Step 8.d.
-        if (!IsObject(nextItem)) {
-            IteratorCloseThrow(iter);
+        if (!IsObject(nextItem))
             ThrowTypeError(JSMSG_INVALID_MAP_ITERABLE, "Map");
-        }
 
         // Steps 8.e-j.
-        try {
-            callContentFunction(adder, map, nextItem[0], nextItem[1]);
-        } catch (e) {
-            IteratorCloseThrow(iter);
-            throw e;
-        }
+        callContentFunction(adder, map, nextItem[0], nextItem[1]);
     }
 }
 
diff --git a/js/src/builtin/Set.js b/js/src/builtin/Set.js
index c61a49ef8c..9af6cf8d1a 100644
--- a/js/src/builtin/Set.js
+++ b/js/src/builtin/Set.js
@@ -14,39 +14,9 @@ function SetConstructorInit(iterable) {
     if (!IsCallable(adder))
         ThrowTypeError(JSMSG_NOT_FUNCTION, typeof adder);
 
-    // Step 6.c.
-    var iterFn = iterable[std_iterator];
-    if (!IsCallable(iterFn))
-        ThrowTypeError(JSMSG_NOT_ITERABLE, DecompileArg(0, iterable));
-
-    var iter = callContentFunction(iterFn, iterable);
-    if (!IsObject(iter))
-        ThrowTypeError(JSMSG_NOT_NONNULL_OBJECT, typeof iter);
-
-    // Step 7 (not applicable).
-
-    // Step 8.
-    while (true) {
-        // Step 8.a.
-        var next = callContentFunction(iter.next, iter);
-        if (!IsObject(next))
-            ThrowTypeError(JSMSG_NOT_NONNULL_OBJECT, typeof next);
-
-        // Step 8.b.
-        if (next.done)
-            return;
-
-        // Step 8.c.
-        var nextValue = next.value;
-
-        // Steps 8.d-e.
-        try {
-            callContentFunction(adder, set, nextValue);
-        } catch (e) {
-            IteratorCloseThrow(iter);
-            throw e;
-        }
-    }
+    // Steps 6.c-8.
+    for (var nextValue of allowContentIter(iterable))
+        callContentFunction(adder, set, nextValue);
 }
 
 /* ES6 20121122 draft 15.16.4.6. */
diff --git a/js/src/builtin/Utilities.js b/js/src/builtin/Utilities.js
index 2dece38016..bfb1fe7f45 100644
--- a/js/src/builtin/Utilities.js
+++ b/js/src/builtin/Utilities.js
@@ -154,29 +154,6 @@ function GetIterator(obj, method) {
     return iterator;
 }
 
-// ES2017 draft rev 7.4.6.
-// When completion.[[Type]] is throw.
-function IteratorCloseThrow(iter) {
-    // Steps 1-2 (implicit)
-
-    // Step 3.
-    var returnMethod = GetMethod(iter, "return");
-
-    // Step 4 (done in caller).
-    if (returnMethod === undefined)
-        return;
-
-    try {
-        // Step 5.
-        callContentFunction(returnMethod, iter);
-    } catch (e) {
-    }
-
-    // Step 6 (done in caller).
-
-    // Steps 7-9 (skipped).
-}
-
 var _builtinCtorsCache = {__proto__: null};
 
 function GetBuiltinConstructor(builtinName) {
diff --git a/js/src/builtin/WeakMap.js b/js/src/builtin/WeakMap.js
index 708be84243..6755b7a7b8 100644
--- a/js/src/builtin/WeakMap.js
+++ b/js/src/builtin/WeakMap.js
@@ -14,43 +14,13 @@ function WeakMapConstructorInit(iterable) {
     if (!IsCallable(adder))
         ThrowTypeError(JSMSG_NOT_FUNCTION, typeof adder);
 
-    // Step 6.c.
-    var iterFn = iterable[std_iterator];
-    if (!IsCallable(iterFn))
-        ThrowTypeError(JSMSG_NOT_ITERABLE, DecompileArg(0, iterable));
-
-    var iter = callContentFunction(iterFn, iterable);
-    if (!IsObject(iter))
-        ThrowTypeError(JSMSG_NOT_NONNULL_OBJECT, typeof iter);
-
-    // Step 7 (not applicable).
-
-    // Step 8.
-    while (true) {
-        // Step 8.a.
-        var next = callContentFunction(iter.next, iter);
-        if (!IsObject(next))
-            ThrowTypeError(JSMSG_NOT_NONNULL_OBJECT, typeof next);
-
-        // Step 8.b.
-        if (next.done)
-            return;
-
-        // Step 8.c.
-        var nextItem = next.value;
-
+    // Steps 6.c-8.
+    for (var nextItem of allowContentIter(iterable)) {
         // Step 8.d.
-        if (!IsObject(nextItem)) {
-            IteratorCloseThrow(iter);
+        if (!IsObject(nextItem))
             ThrowTypeError(JSMSG_INVALID_MAP_ITERABLE, "WeakMap");
-        }
 
         // Steps 8.e-j.
-        try {
-            callContentFunction(adder, map, nextItem[0], nextItem[1]);
-        } catch (e) {
-            IteratorCloseThrow(iter);
-            throw e;
-        }
+        callContentFunction(adder, map, nextItem[0], nextItem[1]);
     }
 }
diff --git a/js/src/builtin/WeakSet.js b/js/src/builtin/WeakSet.js
index 8589f9dc60..b16b4634dd 100644
--- a/js/src/builtin/WeakSet.js
+++ b/js/src/builtin/WeakSet.js
@@ -14,39 +14,9 @@ function WeakSetConstructorInit(iterable) {
     if (!IsCallable(adder))
         ThrowTypeError(JSMSG_NOT_FUNCTION, typeof adder);
 
-    // Step 6.c.
-    var iterFn = iterable[std_iterator];
-    if (!IsCallable(iterFn))
-        ThrowTypeError(JSMSG_NOT_ITERABLE, DecompileArg(0, iterable));
-
-    var iter = callContentFunction(iterFn, iterable);
-    if (!IsObject(iter))
-        ThrowTypeError(JSMSG_NOT_NONNULL_OBJECT, typeof iter);
-
-    // Step 7 (not applicable).
-
-    // Step 8.
-    while (true) {
-        // Step 8.a.
-        var next = callContentFunction(iter.next, iter);
-        if (!IsObject(next))
-            ThrowTypeError(JSMSG_NOT_NONNULL_OBJECT, typeof next);
-
-        // Step 8.b.
-        if (next.done)
-            return;
-
-        // Step 8.c.
-        var nextValue = next.value;
-
-        // Steps 8.d-e.
-        try {
-            callContentFunction(adder, set, nextValue);
-        } catch (e) {
-            IteratorCloseThrow(iter);
-            throw e;
-        }
-    }
+    // Steps 6.c-8.
+    for (var nextValue of allowContentIter(iterable))
+        callContentFunction(adder, set, nextValue);
 }
 
 // 23.4.3.1