Changeset 262567 in webkit for trunk/Source/JavaScriptCore/bytecompiler

Timestamp:

Jun 4, 2020, 1:49:22 PM (5 years ago)

Author:

Alexey Shvayka

Message:

GetMethod isn't performed properly on iterators
​https://bugs.webkit.org/show_bug.cgi?id=212771

Reviewed by Saam Barati.

JSTests:

• test262/expectations.yaml: Mark 26 test cases as passing.

Source/JavaScriptCore:

Before this change, iterator's "return" and "throw" methods with value of null were
considered incorrect rather than missing, causing TypeError to be thrown.

This patch aligns method lookup of iterators with the spec [1], V8, and SpiderMonkey
by utilizing isUndefinedOrNull(), which doesn't special-case IsHTMLDDA objects [2],
fixing a few Annex B tests.

for/of microbenchmarks are neutral.

[1]: ​https://tc39.es/ecma262/#sec-getmethod (step 3)
[2]: ​https://tc39.es/ecma262/#sec-IsHTMLDDA-internal-slot

• builtins/AsyncFromSyncIteratorPrototype.js:
• bytecompiler/BytecodeGenerator.cpp:

(JSC::BytecodeGenerator::emitIteratorGenericClose):
(JSC::BytecodeGenerator::emitGetAsyncIterator):
(JSC::BytecodeGenerator::emitDelegateYield):

• runtime/IteratorOperations.cpp:

(JSC::iteratorClose):

• runtime/JSGenericTypedArrayViewConstructorInlines.h:

(JSC::constructGenericTypedArrayViewWithArguments):

File:

• trunk/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp (modified) (4 diffs)

trunk/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp

@@ -4724 +4724 @@
     Ref<Label> done = newLabel();
     RefPtr<RegisterID> returnMethod = emitGetById(newTemporary(), iterator, propertyNames().returnKeyword);
-    emitJumpIfTrue(emitIsUndefined(newTemporary(), returnMethod.get()), done.get());
+    emitJumpIfTrue(emitIsUndefinedOrNull(newTemporary(), returnMethod.get()), done.get());
 
     RefPtr<RegisterID> value = newTemporary();
@@ -4747 +4747 @@
     Ref<Label> iteratorReceived = newLabel();
 
-    emitJumpIfTrue(emitUnaryOp<OpEqNull>(newTemporary(), iterator.get()), asyncIteratorNotFound.get());
+    emitJumpIfTrue(emitIsUndefinedOrNull(newTemporary(), iterator.get()), asyncIteratorNotFound.get());
 
     emitJump(asyncIteratorFound.get());
@@ -4816 +4816 @@
                     Ref<Label> throwMethodFound = newLabel();
                     RefPtr<RegisterID> throwMethod = emitGetById(newTemporary(), iterator.get(), propertyNames().throwKeyword);
-                    emitJumpIfFalse(emitIsUndefined(newTemporary(), throwMethod.get()), throwMethodFound.get());
+                    emitJumpIfFalse(emitIsUndefinedOrNull(newTemporary(), throwMethod.get()), throwMethodFound.get());
 
                     EmitAwait emitAwaitInIteratorClose = parseMode() == SourceParseMode::AsyncGeneratorBodyMode ? EmitAwait::Yes : EmitAwait::No;
@@ -4837 +4837 @@
                     Ref<Label> returnMethodFound = newLabel();
                     RefPtr<RegisterID> returnMethod = emitGetById(newTemporary(), iterator.get(), propertyNames().returnKeyword);
-                    emitJumpIfFalse(emitIsUndefined(newTemporary(), returnMethod.get()), returnMethodFound.get());
+                    emitJumpIfFalse(emitIsUndefinedOrNull(newTemporary(), returnMethod.get()), returnMethodFound.get());
 
                     move(value.get(), generatorValueRegister());