Changeset 185791 in webkit

Timestamp:

Jun 20, 2015 4:04:27 AM (9 years ago)

Author:

Yusuke Suzuki

Message:

[ES6] Destructuring assignment need to accept iterables
​https://bugs.webkit.org/show_bug.cgi?id=144111

Reviewed by Darin Adler.

Source/JavaScriptCore:

This patch makes that destructuring assignments to array binding patterns accept iterables.
Previously, it just access the indexed properties.
After this patch, it iterates the given value by using ES6 iterator protocol.

The iteration becomes different from the for-of case.

1. Since there's no break/continue case, finally scope is not necessary.
2. When the error is raised, the close status of the iterator becomes true. So IteratorClose is not called for that.
3. Since the array binding patterns requires a limited count of iterations (if there is no rest(...rest) case), IteratorClose is called when the iteration does not consume the all values of the iterator.
4. Since the array binding patterns requires a specified count of iterations, iterator's next call is skipped when iterator becomes closed.

• bytecompiler/BytecodeGenerator.cpp:

(JSC::BytecodeGenerator::emitIteratorClose):

• bytecompiler/BytecodeGenerator.h:
• bytecompiler/NodesCodegen.cpp:

(JSC::ArrayPatternNode::bindValue):

• parser/ASTBuilder.h:

(JSC::ASTBuilder::finishArrayPattern):

• parser/Nodes.h:
• parser/Parser.cpp:

(JSC::Parser<LexerType>::parseDeconstructionPattern):

• parser/SyntaxChecker.h:

(JSC::SyntaxChecker::operatorStackPop):

• tests/stress/destructuring-assignment-accepts-iterables.js: Added.

(shouldBe):
(shouldThrow):
(.set shouldThrow):

LayoutTests:

From this patch, we use iterators for destructuring assignments to array binding patterns.
So test results become different.

• js/destructuring-assignment-expected.txt:
• js/parser-syntax-check-expected.txt:
• js/script-tests/destructuring-assignment.js:

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/js/destructuring-assignment-expected.txt (modified) (1 diff)
• LayoutTests/js/parser-syntax-check-expected.txt (modified) (1 diff)
• LayoutTests/js/script-tests/destructuring-assignment.js (modified) (1 diff)
• Source/JavaScriptCore/ChangeLog (modified) (1 diff)
• Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp (modified) (1 diff)
• Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h (modified) (1 diff)
• Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp (modified) (1 diff)
• Source/JavaScriptCore/parser/ASTBuilder.h (modified) (1 diff)
• Source/JavaScriptCore/parser/Nodes.h (modified) (1 diff)
• Source/JavaScriptCore/parser/Parser.cpp (modified) (2 diffs)
• Source/JavaScriptCore/parser/SyntaxChecker.h (modified) (1 diff)
• Source/JavaScriptCore/tests/stress/destructuring-assignment-accepts-iterables.js (added)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2015-06-20  Yusuke Suzuki  <utatane.tea@gmail.com>
+
+        [ES6] Destructuring assignment need to accept iterables
+        https://bugs.webkit.org/show_bug.cgi?id=144111
+
+        Reviewed by Darin Adler.
+
+        From this patch, we use iterators for destructuring assignments to array binding patterns.
+        So test results become different.
+
+        * js/destructuring-assignment-expected.txt:
+        * js/parser-syntax-check-expected.txt:
+        * js/script-tests/destructuring-assignment.js:
+
 2015-06-19  Dean Jackson  <dino@apple.com>
 

trunk/LayoutTests/js/destructuring-assignment-expected.txt

@@ -81 +81 @@
 PASS testDeconstructArgs('1', '2') is '12'
 PASS testDeconstructArgLength('1', '2') is 2
-PASS testDeconstructArgs('2') is '23'
+PASS testDeconstructArgs('2') is '2undefined'
 PASS a is 1
 PASS b is 2

trunk/LayoutTests/js/parser-syntax-check-expected.txt

@@ -776 +776 @@
 PASS Valid:   "var {x, y}=1"
 PASS Valid:   "function f() { var {x, y}=1 }"
-PASS Valid:   "var [x]=1"
+PASS Valid:   "var [x]=1" with TypeError
 PASS Valid:   "function f() { var [x]=1 }"
-PASS Valid:   "var [x, y]=1"
+PASS Valid:   "var [x, y]=1" with TypeError
 PASS Valid:   "function f() { var [x, y]=1 }"
-PASS Valid:   "[x]=1"
+PASS Valid:   "[x]=1" with TypeError
 PASS Valid:   "function f() { [x]=1 }"
-PASS Valid:   "var [x]=1"
+PASS Valid:   "var [x]=1" with TypeError
 PASS Valid:   "function f() { var [x]=1 }"
 PASS Valid:   "({[x]: 1})"

trunk/LayoutTests/js/script-tests/destructuring-assignment.js

@@ -49 +49 @@
 var text = '3';
 Object.prototype.__defineGetter__(1, function(){ var r = text; text = "fail"; return r; })
-shouldBe("testDeconstructArgs('2')", "'23'");
+shouldBe("testDeconstructArgs('2')", "'2undefined'");
 
 var [a,b] = [1,2], [c,d] = [3,4]

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2015-06-20  Yusuke Suzuki  <utatane.tea@gmail.com>
+
+        [ES6] Destructuring assignment need to accept iterables
+        https://bugs.webkit.org/show_bug.cgi?id=144111
+
+        Reviewed by Darin Adler.
+
+        This patch makes that destructuring assignments to array binding patterns accept iterables.
+        Previously, it just access the indexed properties.
+        After this patch, it iterates the given value by using ES6 iterator protocol.
+
+        The iteration becomes different from the for-of case.
+        1. Since there's no break/continue case, finally scope is not necessary.
+        2. When the error is raised, the close status of the iterator becomes true. So IteratorClose is not called for that.
+        3. Since the array binding patterns requires a limited count of iterations (if there is no rest(...rest) case), IteratorClose is called when the iteration does not consume the all values of the iterator.
+        4. Since the array binding patterns requires a specified count of iterations, iterator's next call is skipped when iterator becomes closed.
+
+        * bytecompiler/BytecodeGenerator.cpp:
+        (JSC::BytecodeGenerator::emitIteratorClose):
+        * bytecompiler/BytecodeGenerator.h:
+        * bytecompiler/NodesCodegen.cpp:
+        (JSC::ArrayPatternNode::bindValue):
+        * parser/ASTBuilder.h:
+        (JSC::ASTBuilder::finishArrayPattern):
+        * parser/Nodes.h:
+        * parser/Parser.cpp:
+        (JSC::Parser<LexerType>::parseDeconstructionPattern):
+        * parser/SyntaxChecker.h:
+        (JSC::SyntaxChecker::operatorStackPop):
+        * tests/stress/destructuring-assignment-accepts-iterables.js: Added.
+        (shouldBe):
+        (shouldThrow):
+        (.set shouldThrow):
+
 2015-06-19  Devin Rousso  <drousso@apple.com>
 

trunk/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp

@@ -2934 +2934 @@
 }
 
-void BytecodeGenerator::emitIteratorClose(RegisterID* iterator, ThrowableExpressionData* node)
+void BytecodeGenerator::emitIteratorClose(RegisterID* iterator, const ThrowableExpressionData* node)
 {
     RefPtr<Label> done = newLabel();

trunk/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h

@@ -547 +547 @@
         RegisterID* emitIsUndefined(RegisterID* dst, RegisterID* src);
 
-        void emitIteratorClose(RegisterID* iterator, ThrowableExpressionData* node);
+        void emitIteratorClose(RegisterID* iterator, const ThrowableExpressionData* node);
 
         void emitReadOnlyExceptionIfNeeded();

trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp

@@ -3129 +3129 @@
     generator.emitLabel(isNotUndefined.get());
 }
-    
+
 void ArrayPatternNode::bindValue(BytecodeGenerator& generator, RegisterID* rhs) const
 {
-    for (size_t i = 0; i < m_targetPatterns.size(); i++) {
-        auto target = m_targetPatterns[i];
+    RefPtr<RegisterID> iterator = generator.newTemporary();
+    {
+        generator.emitGetById(iterator.get(), rhs, generator.propertyNames().iteratorSymbol);
+        CallArguments args(generator, nullptr);
+        generator.emitMove(args.thisRegister(), rhs);
+        generator.emitCall(iterator.get(), iterator.get(), NoExpectedFunction, args, divot(), divotStart(), divotEnd());
+    }
+
+    RefPtr<RegisterID> done;
+    ASSERT(!m_targetPatterns.isEmpty());
+    for (auto& target : m_targetPatterns) {
+        RefPtr<RegisterID> value = generator.newTemporary();
+
+        RefPtr<Label> iterationSkipped = generator.newLabel();
+        if (!done)
+            done = generator.newTemporary();
+        else
+            generator.emitJumpIfTrue(done.get(), iterationSkipped.get());
+
+        {
+            RefPtr<RegisterID> next = generator.emitGetById(generator.newTemporary(), iterator.get(), generator.propertyNames().next);
+            CallArguments nextArguments(generator, nullptr);
+            generator.emitMove(nextArguments.thisRegister(), iterator.get());
+            generator.emitCall(value.get(), next.get(), NoExpectedFunction, nextArguments, divot(), divotStart(), divotEnd());
+        }
+        {
+            RefPtr<Label> typeIsObject = generator.newLabel();
+            generator.emitJumpIfTrue(generator.emitIsObject(generator.newTemporary(), value.get()), typeIsObject.get());
+            generator.emitThrowTypeError(ASCIILiteral("Iterator result interface is not an object."));
+            generator.emitLabel(typeIsObject.get());
+        }
+
+        {
+            generator.emitGetById(done.get(), value.get(), generator.propertyNames().done);
+            RefPtr<Label> valueIsSet = generator.newLabel();
+            generator.emitJumpIfTrue(done.get(), iterationSkipped.get());
+            generator.emitGetById(value.get(), value.get(), generator.propertyNames().value);
+            generator.emitJump(valueIsSet.get());
+            generator.emitLabel(iterationSkipped.get());
+            generator.emitLoad(value.get(), jsUndefined());
+            generator.emitLabel(valueIsSet.get());
+        }
+
         if (!target.pattern)
             continue;
-        RefPtr<RegisterID> temp = generator.newTemporary();
-        generator.emitLoad(temp.get(), jsNumber(i));
-        generator.emitGetByVal(temp.get(), rhs, temp.get());
         if (target.defaultValue)
-            assignDefaultValueIfUndefined(generator, temp.get(), target.defaultValue);
-        target.pattern->bindValue(generator, temp.get());
-    }
+            assignDefaultValueIfUndefined(generator, value.get(), target.defaultValue);
+        target.pattern->bindValue(generator, value.get());
+    }
+
+    RefPtr<Label> iteratorClosed = generator.newLabel();
+    generator.emitJumpIfTrue(done.get(), iteratorClosed.get());
+    generator.emitIteratorClose(iterator.get(), this);
+    generator.emitLabel(iteratorClosed.get());
 }
 

trunk/Source/JavaScriptCore/parser/ASTBuilder.h

@@ -745 +745 @@
         node->appendIndex(location, pattern.get(), defaultValue);
     }
+
+    void finishArrayPattern(ArrayPattern node, const JSTextPosition& divotStart, const JSTextPosition& divot, const JSTextPosition& divotEnd)
+    {
+        setExceptionLocation(node.get(), divotStart, divot, divotEnd);
+    }
     
     ObjectPattern createObjectPattern(const JSTokenLocation&)

trunk/Source/JavaScriptCore/parser/Nodes.h

@@ -1781 +1781 @@
     };
 
-    class ArrayPatternNode : public DeconstructionPatternNode {
+    class ArrayPatternNode : public DeconstructionPatternNode, public ThrowableExpressionData {
     public:
         static Ref<ArrayPatternNode> create();

trunk/Source/JavaScriptCore/parser/Parser.cpp

@@ -598 +598 @@
     switch (m_token.m_type) {
     case OPENBRACKET: {
+        JSTextPosition divotStart = tokenStartPosition();
         auto arrayPattern = context.createArrayPattern(m_token.m_location);
         next();
@@ -623 +624 @@
 
         consumeOrFail(CLOSEBRACKET, "Expected either a closing ']' or a ',' following an element deconstruction pattern");
+        context.finishArrayPattern(arrayPattern, divotStart, divotStart, lastTokenEndPosition());
         pattern = arrayPattern;
         break;

trunk/Source/JavaScriptCore/parser/SyntaxChecker.h

@@ -312 +312 @@
     {
     }
+    void finishArrayPattern(ArrayPattern, const JSTextPosition&, const JSTextPosition&, const JSTextPosition&)
+    {
+    }
     ObjectPattern createObjectPattern(const JSTokenLocation&)
     {