Array.prototype.concat should not modify frozen objects.

https://bugs.webkit.org/show_bug.cgi?id=163302

Reviewed by Filip Pizlo.

JSTests:

* stress/array-concat-on-frozen-object.js: Added.

Source/JavaScriptCore:

The ES6 spec for Array.prototype.concat states that it uses the
CreateDataPropertyOrThrow() to add items to the result array.  The spec for
CreateDataPropertyOrThrow states:

"This abstract operation creates a property whose attributes are set to the same
defaults used for properties created by the ECMAScript language assignment
operator. Normally, the property will not already exist. If it does exist and is
not configurable or if O is not extensible, [[DefineOwnProperty]] will return
false causing this operation to throw a TypeError exception."

Since the properties of frozen objects are not extensible, not configurable, and
not writable, Array.prototype.concat should fail to write to the result array if
it is frozen.

Ref: https://tc39.github.io/ecma262/#sec-array.prototype.concat,
https://tc39.github.io/ecma262/#sec-createdatapropertyorthrow, and
https://tc39.github.io/ecma262/#sec-createdataproperty.

The fix consists of 2 parts:
1. moveElement() should use the PutDirectIndexShouldThrow mode when invoking
   putDirectIndex(), and
2. SparseArrayValueMap::putDirect() should check for the case where the property
   is read only.

(2) ensures that we don't write into a non-writable property.
(1) ensures that we throw a TypeError for attempts to write to a non-writeable
property.

* runtime/ArrayPrototype.cpp:
(JSC::moveElements):
* runtime/SparseArrayValueMap.cpp:
(JSC::SparseArrayValueMap::putDirect):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@207178 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/JSTests/ChangeLog b/JSTests/ChangeLog
index 567503d..3dea92c 100644 (file)
--- a/JSTests/ChangeLog
+++ b/JSTests/ChangeLog
@@ -1,3 +1,12 @@
+2016-10-11  Mark Lam  <mark.lam@apple.com>
+
+        Array.prototype.concat should not modify frozen objects.
+        https://bugs.webkit.org/show_bug.cgi?id=163302
+
+        Reviewed by Filip Pizlo.
+
+        * stress/array-concat-on-frozen-object.js: Added.
+

 2016-10-11  Saam Barati  <sbarati@apple.com>
 
         ValueAdd should be constant folded if the operands are constant String,Primitive or Primitive,String
 2016-10-11  Saam Barati  <sbarati@apple.com>
 
         ValueAdd should be constant folded if the operands are constant String,Primitive or Primitive,String

diff --git a/JSTests/stress/array-concat-on-frozen-object.js b/JSTests/stress/array-concat-on-frozen-object.js
new file mode 100644 (file)
index 0000000..6b785c0
--- /dev/null
+++ b/JSTests/stress/array-concat-on-frozen-object.js
@@ -0,0 +1,72 @@
+//@ runFTLNoCJIT
+
+let totalFailed = 0;
+
+function shouldEqual(testId, actual, expected) {
+    if (actual != expected) {
+        throw testId + ": ERROR: expect " + expected + ", actual " + actual;
+    }
+}
+
+function makeArray() {
+    return ['unmodifiable'];
+}
+
+function makeArrayLikeObject() {
+    var obj = {};
+    obj[0] = 'unmodifiable';
+    obj.length = 1; 
+    return obj;
+}
+
+function emptyArraySourceMaker() {
+    return [];
+}
+
+function singleElementArraySourceMaker() {
+    return ['modified_1'];
+}
+
+// Make test functions with unique codeblocks.
+function makeConcatTest(testId) {
+    return new Function("arr", "return arr.concat(['" + testId + "'])");
+}
+function makeConcatOnHoleyArrayTest(testId) {
+    return new Function("arr", "var other = ['" + testId + "']; other[1000] = '" + testId + "'; return arr.concat(other);");
+}
+
+let numIterations = 10000;
+
+function runTest(testId, testMaker, targetMaker, sourceMaker, expectedValue, expectedException) {
+    var test = testMaker(testId);
+    noInline(test);
+
+    for (var i = 0; i < numIterations; i++) {
+        var exception = undefined;
+
+        var obj = targetMaker();
+        obj = Object.freeze(obj);
+
+        var arr = sourceMaker();
+        arr.constructor = { [Symbol.species]: function() { return obj; } };
+
+        try {
+            test(arr);
+        } catch (e) {
+            exception = "" + e;
+            exception = exception.substr(0, 10); // Search for "TypeError:".
+        }
+        shouldEqual(testId, exception, expectedException);
+        shouldEqual(testId, obj[0], expectedValue);
+    }
+}
+
+runTest(10010, makeConcatTest, makeArray,           emptyArraySourceMaker,         "unmodifiable", "TypeError:");
+runTest(10011, makeConcatTest, makeArray,           singleElementArraySourceMaker, "unmodifiable", "TypeError:");
+runTest(10020, makeConcatTest, makeArrayLikeObject, emptyArraySourceMaker,         "unmodifiable", "TypeError:");
+runTest(10021, makeConcatTest, makeArrayLikeObject, singleElementArraySourceMaker, "unmodifiable", "TypeError:");
+
+runTest(10110, makeConcatOnHoleyArrayTest, makeArray,           emptyArraySourceMaker,         "unmodifiable", "TypeError:");
+runTest(10111, makeConcatOnHoleyArrayTest, makeArray,           singleElementArraySourceMaker, "unmodifiable", "TypeError:");
+runTest(10120, makeConcatOnHoleyArrayTest, makeArrayLikeObject, emptyArraySourceMaker,         "unmodifiable", "TypeError:");
+runTest(10121, makeConcatOnHoleyArrayTest, makeArrayLikeObject, singleElementArraySourceMaker, "unmodifiable", "TypeError:");

diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
index eca9b65..0e74e1f 100644 (file)
--- a/Source/JavaScriptCore/ChangeLog
+++ b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,43 @@
+2016-10-11  Mark Lam  <mark.lam@apple.com>
+
+        Array.prototype.concat should not modify frozen objects.
+        https://bugs.webkit.org/show_bug.cgi?id=163302
+
+        Reviewed by Filip Pizlo.
+
+        The ES6 spec for Array.prototype.concat states that it uses the
+        CreateDataPropertyOrThrow() to add items to the result array.  The spec for
+        CreateDataPropertyOrThrow states:
+
+        "This abstract operation creates a property whose attributes are set to the same
+        defaults used for properties created by the ECMAScript language assignment
+        operator. Normally, the property will not already exist. If it does exist and is
+        not configurable or if O is not extensible, [[DefineOwnProperty]] will return
+        false causing this operation to throw a TypeError exception."
+
+        Since the properties of frozen objects are not extensible, not configurable, and
+        not writable, Array.prototype.concat should fail to write to the result array if
+        it is frozen.
+
+        Ref: https://tc39.github.io/ecma262/#sec-array.prototype.concat,
+        https://tc39.github.io/ecma262/#sec-createdatapropertyorthrow, and
+        https://tc39.github.io/ecma262/#sec-createdataproperty.
+
+        The fix consists of 2 parts:
+        1. moveElement() should use the PutDirectIndexShouldThrow mode when invoking
+           putDirectIndex(), and
+        2. SparseArrayValueMap::putDirect() should check for the case where the property
+           is read only.
+
+        (2) ensures that we don't write into a non-writable property.
+        (1) ensures that we throw a TypeError for attempts to write to a non-writeable
+        property.
+
+        * runtime/ArrayPrototype.cpp:
+        (JSC::moveElements):
+        * runtime/SparseArrayValueMap.cpp:
+        (JSC::SparseArrayValueMap::putDirect):
+

 2016-10-11  Yusuke Suzuki  <utatane.tea@gmail.com>
 
         [DOMJIT] DOMJIT::Patchpoint should have a way to receive constant folded arguments
 2016-10-11  Yusuke Suzuki  <utatane.tea@gmail.com>
 
         [DOMJIT] DOMJIT::Patchpoint should have a way to receive constant folded arguments

diff --git a/Source/JavaScriptCore/runtime/ArrayPrototype.cpp b/Source/JavaScriptCore/runtime/ArrayPrototype.cpp
index bd22b6e..ce6b94e 100644 (file)
--- a/Source/JavaScriptCore/runtime/ArrayPrototype.cpp
+++ b/Source/JavaScriptCore/runtime/ArrayPrototype.cpp
@@ -1078,7 +1078,7 @@ static bool moveElements(ExecState* exec, VM& vm, JSArray* target, unsigned targ
         for (unsigned i = 0; i < sourceLength; ++i) {
             JSValue value = source->tryGetIndexQuickly(i);
             if (value) {
         for (unsigned i = 0; i < sourceLength; ++i) {
             JSValue value = source->tryGetIndexQuickly(i);
             if (value) {

-                target->putDirectIndex(exec, targetOffset + i, value);
+                target->putDirectIndex(exec, targetOffset + i, value, 0, PutDirectIndexShouldThrow);

                 RETURN_IF_EXCEPTION(scope, false);
             }
         }
                 RETURN_IF_EXCEPTION(scope, false);
             }
         }


@@ -1087,7 +1087,7 @@ static bool moveElements(ExecState* exec, VM& vm, JSArray* target, unsigned targ
             JSValue value = getProperty(exec, source, i);
             RETURN_IF_EXCEPTION(scope, false);
             if (value) {
             JSValue value = getProperty(exec, source, i);
             RETURN_IF_EXCEPTION(scope, false);
             if (value) {

-                target->putDirectIndex(exec, targetOffset + i, value);
+                target->putDirectIndex(exec, targetOffset + i, value, 0, PutDirectIndexShouldThrow);

                 RETURN_IF_EXCEPTION(scope, false);
             }
         }
                 RETURN_IF_EXCEPTION(scope, false);
             }
         }

diff --git a/Source/JavaScriptCore/runtime/SparseArrayValueMap.cpp b/Source/JavaScriptCore/runtime/SparseArrayValueMap.cpp
index 1fb9a06..990c6c2 100644 (file)
--- a/Source/JavaScriptCore/runtime/SparseArrayValueMap.cpp
+++ b/Source/JavaScriptCore/runtime/SparseArrayValueMap.cpp
@@ -117,14 +117,17 @@ bool SparseArrayValueMap::putDirect(ExecState* exec, JSObject* array, unsigned i
     AddResult result = add(array, i);
     SparseArrayEntry& entry = result.iterator->value;
 
     AddResult result = add(array, i);
     SparseArrayEntry& entry = result.iterator->value;
 

-    // To save a separate find & add, we first always add to the sparse map.
-    // In the uncommon case that this is a new property, and the array is not
-    // extensible, this is not the right thing to have done - so remove again.
-    if (mode != PutDirectIndexLikePutDirect && result.isNewEntry && !array->isStructureExtensible()) {
-        remove(result.iterator);
-        return reject(exec, mode == PutDirectIndexShouldThrow, "Attempting to define property on object that is not extensible.");
+    if (mode != PutDirectIndexLikePutDirect && !array->isStructureExtensible()) {
+        // To save a separate find & add, we first always add to the sparse map.
+        // In the uncommon case that this is a new property, and the array is not
+        // extensible, this is not the right thing to have done - so remove again.
+        if (result.isNewEntry) {
+            remove(result.iterator);
+            return reject(exec, mode == PutDirectIndexShouldThrow, "Attempting to define property on object that is not extensible.");
+        }
+        if (entry.attributes & ReadOnly)
+            return reject(exec, mode == PutDirectIndexShouldThrow, ReadonlyPropertyWriteError);

     }
     }

-

     entry.attributes = attributes;
     entry.set(exec->vm(), this, value);
     return true;
     entry.attributes = attributes;
     entry.set(exec->vm(), this, value);
     return true;