Add m-esr52 at 52.6.0

1 files changed, 599 insertions, 0 deletions

diff --git a/js/src/frontend/SyntaxParseHandler.h b/js/src/frontend/SyntaxParseHandler.h
new file mode 100644
index 000000000..75c7e3333
--- /dev/null
+++ b/js/src/frontend/SyntaxParseHandler.h
@@ -0,0 +1,599 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef frontend_SyntaxParseHandler_h
+#define frontend_SyntaxParseHandler_h
+
+#include "mozilla/Attributes.h"
+
+#include "frontend/ParseNode.h"
+#include "frontend/TokenStream.h"
+
+namespace js {
+namespace frontend {
+
+template <typename ParseHandler>
+class Parser;
+
+// Parse handler used when processing the syntax in a block of code, to generate
+// the minimal information which is required to detect syntax errors and allow
+// bytecode to be emitted for outer functions.
+//
+// When parsing, we start at the top level with a full parse, and when possible
+// only check the syntax for inner functions, so that they can be lazily parsed
+// into bytecode when/if they first run. Checking the syntax of a function is
+// several times faster than doing a full parse/emit, and lazy parsing improves
+// both performance and memory usage significantly when pages contain large
+// amounts of code that never executes (which happens often).
+class SyntaxParseHandler
+{
+    // Remember the last encountered name or string literal during syntax parses.
+    JSAtom* lastAtom;
+    TokenPos lastStringPos;
+    TokenStream& tokenStream;
+
+  public:
+    enum Node {
+        NodeFailure = 0,
+        NodeGeneric,
+        NodeGetProp,
+        NodeStringExprStatement,
+        NodeReturn,
+        NodeBreak,
+        NodeThrow,
+        NodeEmptyStatement,
+
+        NodeVarDeclaration,
+        NodeLexicalDeclaration,
+
+        NodeFunctionDefinition,
+
+        // This is needed for proper assignment-target handling.  ES6 formally
+        // requires function calls *not* pass IsValidSimpleAssignmentTarget,
+        // but at last check there were still sites with |f() = 5| and similar
+        // in code not actually executed (or at least not executed enough to be
+        // noticed).
+        NodeFunctionCall,
+
+        // Nodes representing *parenthesized* IsValidSimpleAssignmentTarget
+        // nodes.  We can't simply treat all such parenthesized nodes
+        // identically, because in assignment and increment/decrement contexts
+        // ES6 says that parentheses constitute a syntax error.
+        //
+        //   var obj = {};
+        //   var val;
+        //   (val) = 3; (obj.prop) = 4;       // okay per ES5's little mind
+        //   [(a)] = [3]; [(obj.prop)] = [4]; // invalid ES6 syntax
+        //   // ...and so on for the other IsValidSimpleAssignmentTarget nodes
+        //
+        // We don't know in advance in the current parser when we're parsing
+        // in a place where name parenthesization changes meaning, so we must
+        // have multiple node values for these cases.
+        NodeParenthesizedArgumentsName,
+        NodeParenthesizedEvalName,
+        NodeParenthesizedName,
+
+        NodeDottedProperty,
+        NodeElement,
+
+        // Destructuring target patterns can't be parenthesized: |([a]) = [3];|
+        // must be a syntax error.  (We can't use NodeGeneric instead of these
+        // because that would trigger invalid-left-hand-side ReferenceError
+        // semantics when SyntaxError semantics are desired.)
+        NodeParenthesizedArray,
+        NodeParenthesizedObject,
+
+        // In rare cases a parenthesized |node| doesn't have the same semantics
+        // as |node|.  Each such node has a special Node value, and we use a
+        // different Node value to represent the parenthesized form.  See also
+        // is{Unp,P}arenthesized*(Node), parenthesize(Node), and the various
+        // functions that deal in NodeUnparenthesized* below.
+
+        // Nodes representing unparenthesized names.
+        NodeUnparenthesizedArgumentsName,
+        NodeUnparenthesizedAsyncName,
+        NodeUnparenthesizedEvalName,
+        NodeUnparenthesizedName,
+
+        // Valuable for recognizing potential destructuring patterns.
+        NodeUnparenthesizedArray,
+        NodeUnparenthesizedObject,
+
+        // The directive prologue at the start of a FunctionBody or ScriptBody
+        // is the longest sequence (possibly empty) of string literal
+        // expression statements at the start of a function.  Thus we need this
+        // to treat |"use strict";| as a possible Use Strict Directive and
+        // |("use strict");| as a useless statement.
+        NodeUnparenthesizedString,
+
+        // Legacy generator expressions of the form |(expr for (...))| and
+        // array comprehensions of the form |[expr for (...)]|) don't permit
+        // |expr| to be a comma expression.  Thus we need this to treat
+        // |(a(), b for (x in []))| as a syntax error and
+        // |((a(), b) for (x in []))| as a generator that calls |a| and then
+        // yields |b| each time it's resumed.
+        NodeUnparenthesizedCommaExpr,
+
+        // Assignment expressions in condition contexts could be typos for
+        // equality checks.  (Think |if (x = y)| versus |if (x == y)|.)  Thus
+        // we need this to treat |if (x = y)| as a possible typo and
+        // |if ((x = y))| as a deliberate assignment within a condition.
+        //
+        // (Technically this isn't needed, as these are *only* extraWarnings
+        // warnings, and parsing with that option disables syntax parsing.  But
+        // it seems best to be consistent, and perhaps the syntax parser will
+        // eventually enforce extraWarnings and will require this then.)
+        NodeUnparenthesizedAssignment,
+
+        // This node is necessary to determine if the base operand in an
+        // exponentiation operation is an unparenthesized unary expression.
+        // We want to reject |-2 ** 3|, but still need to allow |(-2) ** 3|.
+        NodeUnparenthesizedUnary,
+
+        // This node is necessary to determine if the LHS of a property access is
+        // super related.
+        NodeSuperBase
+    };
+
+    bool isPropertyAccess(Node node) {
+        return node == NodeDottedProperty || node == NodeElement;
+    }
+
+    bool isFunctionCall(Node node) {
+        // Note: super() is a special form, *not* a function call.
+        return node == NodeFunctionCall;
+    }
+
+    static bool isUnparenthesizedDestructuringPattern(Node node) {
+        return node == NodeUnparenthesizedArray || node == NodeUnparenthesizedObject;
+    }
+
+    static bool isParenthesizedDestructuringPattern(Node node) {
+        // Technically this isn't a destructuring target at all -- the grammar
+        // doesn't treat it as such.  But we need to know when this happens to
+        // consider it a SyntaxError rather than an invalid-left-hand-side
+        // ReferenceError.
+        return node == NodeParenthesizedArray || node == NodeParenthesizedObject;
+    }
+
+    static bool isDestructuringPatternAnyParentheses(Node node) {
+        return isUnparenthesizedDestructuringPattern(node) ||
+                isParenthesizedDestructuringPattern(node);
+    }
+
+  public:
+    SyntaxParseHandler(ExclusiveContext* cx, LifoAlloc& alloc,
+                       TokenStream& tokenStream, Parser<SyntaxParseHandler>* syntaxParser,
+                       LazyScript* lazyOuterFunction)
+      : lastAtom(nullptr),
+        tokenStream(tokenStream)
+    {}
+
+    static Node null() { return NodeFailure; }
+
+    void prepareNodeForMutation(Node node) {}
+    void freeTree(Node node) {}
+
+    void trace(JSTracer* trc) {}
+
+    Node newName(PropertyName* name, const TokenPos& pos, ExclusiveContext* cx) {
+        lastAtom = name;
+        if (name == cx->names().arguments)
+            return NodeUnparenthesizedArgumentsName;
+        if (name == cx->names().async)
+            return NodeUnparenthesizedAsyncName;
+        if (name == cx->names().eval)
+            return NodeUnparenthesizedEvalName;
+        return NodeUnparenthesizedName;
+    }
+
+    Node newComputedName(Node expr, uint32_t start, uint32_t end) {
+        return NodeGeneric;
+    }
+
+    Node newObjectLiteralPropertyName(JSAtom* atom, const TokenPos& pos) {
+        return NodeUnparenthesizedName;
+    }
+
+    Node newNumber(double value, DecimalPoint decimalPoint, const TokenPos& pos) { return NodeGeneric; }
+    Node newBooleanLiteral(bool cond, const TokenPos& pos) { return NodeGeneric; }
+
+    Node newStringLiteral(JSAtom* atom, const TokenPos& pos) {
+        lastAtom = atom;
+        lastStringPos = pos;
+        return NodeUnparenthesizedString;
+    }
+
+    Node newTemplateStringLiteral(JSAtom* atom, const TokenPos& pos) {
+        return NodeGeneric;
+    }
+
+    Node newCallSiteObject(uint32_t begin) {
+        return NodeGeneric;
+    }
+
+    void addToCallSiteObject(Node callSiteObj, Node rawNode, Node cookedNode) {}
+
+    Node newThisLiteral(const TokenPos& pos, Node thisName) { return NodeGeneric; }
+    Node newNullLiteral(const TokenPos& pos) { return NodeGeneric; }
+
+    template <class Boxer>
+    Node newRegExp(RegExpObject* reobj, const TokenPos& pos, Boxer& boxer) { return NodeGeneric; }
+
+    Node newConditional(Node cond, Node thenExpr, Node elseExpr) { return NodeGeneric; }
+
+    Node newElision() { return NodeGeneric; }
+
+    Node newDelete(uint32_t begin, Node expr) {
+        return NodeUnparenthesizedUnary;
+    }
+
+    Node newTypeof(uint32_t begin, Node kid) {
+        return NodeUnparenthesizedUnary;
+    }
+
+    Node newUnary(ParseNodeKind kind, JSOp op, uint32_t begin, Node kid) {
+        return NodeUnparenthesizedUnary;
+    }
+
+    Node newUpdate(ParseNodeKind kind, uint32_t begin, Node kid) {
+        return NodeGeneric;
+    }
+
+    Node newSpread(uint32_t begin, Node kid) {
+        return NodeGeneric;
+    }
+
+    Node newArrayPush(uint32_t begin, Node kid) {
+        return NodeGeneric;
+    }
+
+    Node newBinary(ParseNodeKind kind, JSOp op = JSOP_NOP) { return NodeGeneric; }
+    Node newBinary(ParseNodeKind kind, Node left, JSOp op = JSOP_NOP) { return NodeGeneric; }
+    Node newBinary(ParseNodeKind kind, Node left, Node right, JSOp op = JSOP_NOP) {
+        return NodeGeneric;
+    }
+    Node appendOrCreateList(ParseNodeKind kind, Node left, Node right,
+                            ParseContext* pc, JSOp op = JSOP_NOP) {
+        return NodeGeneric;
+    }
+
+    Node newTernary(ParseNodeKind kind, Node first, Node second, Node third, JSOp op = JSOP_NOP) {
+        return NodeGeneric;
+    }
+
+    // Expressions
+
+    Node newArrayComprehension(Node body, const TokenPos& pos) { return NodeGeneric; }
+    Node newArrayLiteral(uint32_t begin) { return NodeUnparenthesizedArray; }
+    MOZ_MUST_USE bool addElision(Node literal, const TokenPos& pos) { return true; }
+    MOZ_MUST_USE bool addSpreadElement(Node literal, uint32_t begin, Node inner) { return true; }
+    void addArrayElement(Node literal, Node element) { }
+
+    Node newCall() { return NodeFunctionCall; }
+    Node newTaggedTemplate() { return NodeGeneric; }
+
+    Node newObjectLiteral(uint32_t begin) { return NodeUnparenthesizedObject; }
+    Node newClassMethodList(uint32_t begin) { return NodeGeneric; }
+    Node newClassNames(Node outer, Node inner, const TokenPos& pos) { return NodeGeneric; }
+    Node newClass(Node name, Node heritage, Node methodBlock) { return NodeGeneric; }
+
+    Node newNewTarget(Node newHolder, Node targetHolder) { return NodeGeneric; }
+    Node newPosHolder(const TokenPos& pos) { return NodeGeneric; }
+    Node newSuperBase(Node thisName, const TokenPos& pos) { return NodeSuperBase; }
+
+    MOZ_MUST_USE bool addPrototypeMutation(Node literal, uint32_t begin, Node expr) { return true; }
+    MOZ_MUST_USE bool addPropertyDefinition(Node literal, Node name, Node expr) { return true; }
+    MOZ_MUST_USE bool addShorthand(Node literal, Node name, Node expr) { return true; }
+    MOZ_MUST_USE bool addObjectMethodDefinition(Node literal, Node name, Node fn, JSOp op) { return true; }
+    MOZ_MUST_USE bool addClassMethodDefinition(Node literal, Node name, Node fn, JSOp op, bool isStatic) { return true; }
+    Node newYieldExpression(uint32_t begin, Node value, Node gen) { return NodeGeneric; }
+    Node newYieldStarExpression(uint32_t begin, Node value, Node gen) { return NodeGeneric; }
+    Node newAwaitExpression(uint32_t begin, Node value, Node gen) { return NodeGeneric; }
+
+    // Statements
+
+    Node newStatementList(const TokenPos& pos) { return NodeGeneric; }
+    void addStatementToList(Node list, Node stmt) {}
+    void addCaseStatementToList(Node list, Node stmt) {}
+    MOZ_MUST_USE bool prependInitialYield(Node stmtList, Node gen) { return true; }
+    Node newEmptyStatement(const TokenPos& pos) { return NodeEmptyStatement; }
+
+    Node newSetThis(Node thisName, Node value) { return value; }
+
+    Node newExprStatement(Node expr, uint32_t end) {
+        return expr == NodeUnparenthesizedString ? NodeStringExprStatement : NodeGeneric;
+    }
+
+    Node newIfStatement(uint32_t begin, Node cond, Node then, Node else_) { return NodeGeneric; }
+    Node newDoWhileStatement(Node body, Node cond, const TokenPos& pos) { return NodeGeneric; }
+    Node newWhileStatement(uint32_t begin, Node cond, Node body) { return NodeGeneric; }
+    Node newSwitchStatement(uint32_t begin, Node discriminant, Node caseList) { return NodeGeneric; }
+    Node newCaseOrDefault(uint32_t begin, Node expr, Node body) { return NodeGeneric; }
+    Node newContinueStatement(PropertyName* label, const TokenPos& pos) { return NodeGeneric; }
+    Node newBreakStatement(PropertyName* label, const TokenPos& pos) { return NodeBreak; }
+    Node newReturnStatement(Node expr, const TokenPos& pos) { return NodeReturn; }
+    Node newWithStatement(uint32_t begin, Node expr, Node body) { return NodeGeneric; }
+
+    Node newLabeledStatement(PropertyName* label, Node stmt, uint32_t begin) {
+        return NodeGeneric;
+    }
+
+    Node newThrowStatement(Node expr, const TokenPos& pos) { return NodeThrow; }
+    Node newTryStatement(uint32_t begin, Node body, Node catchList, Node finallyBlock) {
+        return NodeGeneric;
+    }
+    Node newDebuggerStatement(const TokenPos& pos) { return NodeGeneric; }
+
+    Node newPropertyAccess(Node pn, PropertyName* name, uint32_t end) {
+        lastAtom = name;
+        return NodeDottedProperty;
+    }
+
+    Node newPropertyByValue(Node pn, Node kid, uint32_t end) { return NodeElement; }
+
+    MOZ_MUST_USE bool addCatchBlock(Node catchList, Node letBlock, Node catchName,
+                                    Node catchGuard, Node catchBody) { return true; }
+
+    MOZ_MUST_USE bool setLastFunctionFormalParameterDefault(Node funcpn, Node pn) { return true; }
+    Node newFunctionDefinition() { return NodeFunctionDefinition; }
+    bool setComprehensionLambdaBody(Node pn, Node body) { return true; }
+    void setFunctionFormalParametersAndBody(Node pn, Node kid) {}
+    void setFunctionBody(Node pn, Node kid) {}
+    void setFunctionBox(Node pn, FunctionBox* funbox) {}
+    void addFunctionFormalParameter(Node pn, Node argpn) {}
+
+    Node newForStatement(uint32_t begin, Node forHead, Node body, unsigned iflags) {
+        return NodeGeneric;
+    }
+
+    Node newComprehensionFor(uint32_t begin, Node forHead, Node body) {
+        return NodeGeneric;
+    }
+
+    Node newComprehensionBinding(Node kid) {
+        // Careful: we're asking this well after the name was parsed, so the
+        // value returned may not correspond to |kid|'s actual name.  But it
+        // *will* be truthy iff |kid| was a name, so we're safe.
+        MOZ_ASSERT(isUnparenthesizedName(kid));
+        return NodeGeneric;
+    }
+
+    Node newForHead(Node init, Node test, Node update, const TokenPos& pos) {
+        return NodeGeneric;
+    }
+
+    Node newForInOrOfHead(ParseNodeKind kind, Node target, Node iteratedExpr, const TokenPos& pos) {
+        return NodeGeneric;
+    }
+
+    MOZ_MUST_USE bool finishInitializerAssignment(Node pn, Node init) { return true; }
+
+    void setBeginPosition(Node pn, Node oth) {}
+    void setBeginPosition(Node pn, uint32_t begin) {}
+
+    void setEndPosition(Node pn, Node oth) {}
+    void setEndPosition(Node pn, uint32_t end) {}
+
+    void setPosition(Node pn, const TokenPos& pos) {}
+    TokenPos getPosition(Node pn) {
+        return tokenStream.currentToken().pos;
+    }
+
+    Node newList(ParseNodeKind kind, JSOp op = JSOP_NOP) {
+        MOZ_ASSERT(kind != PNK_VAR);
+        MOZ_ASSERT(kind != PNK_LET);
+        MOZ_ASSERT(kind != PNK_CONST);
+        return NodeGeneric;
+    }
+    Node newList(ParseNodeKind kind, uint32_t begin, JSOp op = JSOP_NOP) {
+        return newList(kind, op);
+    }
+    Node newList(ParseNodeKind kind, Node kid, JSOp op = JSOP_NOP) {
+        return newList(kind, op);
+    }
+
+    Node newDeclarationList(ParseNodeKind kind, JSOp op = JSOP_NOP) {
+        if (kind == PNK_VAR)
+            return NodeVarDeclaration;
+        MOZ_ASSERT(kind == PNK_LET || kind == PNK_CONST);
+        return NodeLexicalDeclaration;
+    }
+    Node newDeclarationList(ParseNodeKind kind, Node kid, JSOp op = JSOP_NOP) {
+        return newDeclarationList(kind, op);
+    }
+
+    bool isDeclarationList(Node node) {
+        return node == NodeVarDeclaration || node == NodeLexicalDeclaration;
+    }
+
+    Node singleBindingFromDeclaration(Node decl) {
+        MOZ_ASSERT(isDeclarationList(decl));
+
+        // This is, unfortunately, very dodgy.  Obviously NodeVarDeclaration
+        // and NodeLexicalDeclaration can store no info on the arbitrary
+        // number of bindings it could contain.
+        //
+        // But this method is called only for cloning for-in/of declarations
+        // as initialization targets.  That context simplifies matters.  If the
+        // binding is a single name, it'll always syntax-parse (or it would
+        // already have been rejected as assigning/binding a forbidden name).
+        // Otherwise the binding is a destructuring pattern.  But syntax
+        // parsing would *already* have aborted when it saw a destructuring
+        // pattern.  So we can just say any old thing here, because the only
+        // time we'll be wrong is a case that syntax parsing has already
+        // rejected.  Use NodeUnparenthesizedName so the SyntaxParseHandler
+        // Parser::cloneLeftHandSide can assert it sees only this.
+        return NodeUnparenthesizedName;
+    }
+
+    Node newCatchList() {
+        return newList(PNK_CATCHLIST, JSOP_NOP);
+    }
+
+    Node newCommaExpressionList(Node kid) {
+        return NodeUnparenthesizedCommaExpr;
+    }
+
+    void addList(Node list, Node kid) {
+        MOZ_ASSERT(list == NodeGeneric ||
+                   list == NodeUnparenthesizedArray ||
+                   list == NodeUnparenthesizedObject ||
+                   list == NodeUnparenthesizedCommaExpr ||
+                   list == NodeVarDeclaration ||
+                   list == NodeLexicalDeclaration ||
+                   list == NodeFunctionCall);
+    }
+
+    Node newAssignment(ParseNodeKind kind, Node lhs, Node rhs, JSOp op) {
+        if (kind == PNK_ASSIGN)
+            return NodeUnparenthesizedAssignment;
+        return newBinary(kind, lhs, rhs, op);
+    }
+
+    bool isUnparenthesizedCommaExpression(Node node) {
+        return node == NodeUnparenthesizedCommaExpr;
+    }
+
+    bool isUnparenthesizedAssignment(Node node) {
+        return node == NodeUnparenthesizedAssignment;
+    }
+
+    bool isUnparenthesizedUnaryExpression(Node node) {
+        return node == NodeUnparenthesizedUnary;
+    }
+
+    bool isReturnStatement(Node node) {
+        return node == NodeReturn;
+    }
+
+    bool isStatementPermittedAfterReturnStatement(Node pn) {
+        return pn == NodeFunctionDefinition || pn == NodeVarDeclaration ||
+               pn == NodeBreak ||
+               pn == NodeThrow ||
+               pn == NodeEmptyStatement;
+    }
+
+    bool isSuperBase(Node pn) {
+        return pn == NodeSuperBase;
+    }
+
+    void setOp(Node pn, JSOp op) {}
+    void setListFlag(Node pn, unsigned flag) {}
+    MOZ_MUST_USE Node parenthesize(Node node) {
+        // A number of nodes have different behavior upon parenthesization, but
+        // only in some circumstances.  Convert these nodes to special
+        // parenthesized forms.
+        if (node == NodeUnparenthesizedArgumentsName)
+            return NodeParenthesizedArgumentsName;
+        if (node == NodeUnparenthesizedEvalName)
+            return NodeParenthesizedEvalName;
+        if (node == NodeUnparenthesizedName || node == NodeUnparenthesizedAsyncName)
+            return NodeParenthesizedName;
+
+        if (node == NodeUnparenthesizedArray)
+            return NodeParenthesizedArray;
+        if (node == NodeUnparenthesizedObject)
+            return NodeParenthesizedObject;
+
+        // Other nodes need not be recognizable after parenthesization; convert
+        // them to a generic node.
+        if (node == NodeUnparenthesizedString ||
+            node == NodeUnparenthesizedCommaExpr ||
+            node == NodeUnparenthesizedAssignment ||
+            node == NodeUnparenthesizedUnary)
+        {
+            return NodeGeneric;
+        }
+
+        // In all other cases, the parenthesized form of |node| is equivalent
+        // to the unparenthesized form: return |node| unchanged.
+        return node;
+    }
+    MOZ_MUST_USE Node setLikelyIIFE(Node pn) {
+        return pn; // Remain in syntax-parse mode.
+    }
+    void setPrologue(Node pn) {}
+
+    bool isConstant(Node pn) { return false; }
+
+    bool isUnparenthesizedName(Node node) {
+        return node == NodeUnparenthesizedArgumentsName ||
+               node == NodeUnparenthesizedAsyncName ||
+               node == NodeUnparenthesizedEvalName ||
+               node == NodeUnparenthesizedName;
+    }
+
+    bool isNameAnyParentheses(Node node) {
+        if (isUnparenthesizedName(node))
+            return true;
+        return node == NodeParenthesizedArgumentsName ||
+               node == NodeParenthesizedEvalName ||
+               node == NodeParenthesizedName;
+    }
+
+    bool nameIsEvalAnyParentheses(Node node, ExclusiveContext* cx) {
+        MOZ_ASSERT(isNameAnyParentheses(node),
+                   "must only call this function on known names");
+        return node == NodeUnparenthesizedEvalName || node == NodeParenthesizedEvalName;
+    }
+
+    const char* nameIsArgumentsEvalAnyParentheses(Node node, ExclusiveContext* cx) {
+        MOZ_ASSERT(isNameAnyParentheses(node),
+                   "must only call this method on known names");
+
+        if (nameIsEvalAnyParentheses(node, cx))
+            return js_eval_str;
+        if (node == NodeUnparenthesizedArgumentsName || node == NodeParenthesizedArgumentsName)
+            return js_arguments_str;
+        return nullptr;
+    }
+
+    bool nameIsUnparenthesizedAsync(Node node, ExclusiveContext* cx) {
+        MOZ_ASSERT(isNameAnyParentheses(node),
+                   "must only call this function on known names");
+        return node == NodeUnparenthesizedAsyncName;
+    }
+
+    PropertyName* maybeDottedProperty(Node node) {
+        // Note: |super.apply(...)| is a special form that calls an "apply"
+        // method retrieved from one value, but using a *different* value as
+        // |this|.  It's not really eligible for the funapply/funcall
+        // optimizations as they're currently implemented (assuming a single
+        // value is used for both retrieval and |this|).
+        if (node != NodeDottedProperty)
+            return nullptr;
+        return lastAtom->asPropertyName();
+    }
+
+    JSAtom* isStringExprStatement(Node pn, TokenPos* pos) {
+        if (pn == NodeStringExprStatement) {
+            *pos = lastStringPos;
+            return lastAtom;
+        }
+        return nullptr;
+    }
+
+    bool canSkipLazyInnerFunctions() {
+        return false;
+    }
+    bool canSkipLazyClosedOverBindings() {
+        return false;
+    }
+    JSAtom* nextLazyClosedOverBinding() {
+        MOZ_CRASH("SyntaxParseHandler::canSkipLazyClosedOverBindings must return false");
+    }
+
+    void adjustGetToSet(Node node) {}
+
+    void disableSyntaxParser() {
+    }
+};
+
+} // namespace frontend
+} // namespace js
+
+#endif /* frontend_SyntaxParseHandler_h */