Changeset 187108 in webkit for trunk/Source/JavaScriptCore/parser/Parser.cpp

Timestamp:

Jul 21, 2015, 11:18:42 AM (10 years ago)

Author:

[email protected]

Message:

Add support for the new.target syntax.
​https://bugs.webkit.org/show_bug.cgi?id=147051

Patch by Keith Miller <​[email protected]> on 2015-07-21
Reviewed by Yusuke Suzuki.

Add support for new.target. Essentially the implementation is, before constructor calls,
the target of a "new" is placed where "this" noramlly goes in the calling convention.
Then in the constructor before object is initialized we move the target of the "new"
into a local variable.

• bytecompiler/BytecodeGenerator.cpp:

(JSC::BytecodeGenerator::BytecodeGenerator):

• bytecompiler/NodesCodegen.cpp:

(JSC::NewTargetNode::emitBytecode):

• parser/ASTBuilder.h:

(JSC::ASTBuilder::newTargetExpr):

• parser/NodeConstructors.h:

(JSC::NewTargetNode::NewTargetNode):

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

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

• parser/SyntaxChecker.h:

(JSC::SyntaxChecker::newTargetExpr):

• runtime/CommonIdentifiers.h:
• tests/stress/new-target.js: Added.

(test):
(call):
(Constructor.subCall):
(Constructor.SubConstructor):
(Constructor):
(noAssign):
(doWeirdThings):
(SuperClass):
(SubClass):

File:

• trunk/Source/JavaScriptCore/parser/Parser.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/parser/Parser.cpp

@@ -2884 +2884 @@
 #endif
 
+    bool baseIsNewTarget = false;
+    if (newCount && match(DOT)) {
+        next();
+        if (match(IDENT)) {
+            const Identifier* ident = m_token.m_data.ident;
+            if (m_vm->propertyNames->target == *ident) {
+                semanticFailIfFalse(currentScope()->isFunction(), "new.target is only valid inside functions");
+                baseIsNewTarget = true;
+                base = context.newTargetExpr(location);
+                newCount--;
+                next();
+            } else
+                failWithMessage("\"new.\" can only followed with target");
+        } else
+            failDueToUnexpectedToken();
+    }
+
     if (baseIsSuper) {
         base = context.superExpr(location);
         next();
         currentScope()->setNeedsSuperBinding();
-    } else
+    } else if (!baseIsNewTarget)
         base = parsePrimaryExpression(context);