1 files changed, 33 insertions, 20 deletions

diff --git a/js/src/frontend/Parser.h b/js/src/frontend/Parser.h
index 8bd691fc4..88d2dad18 100644
--- a/js/src/frontend/Parser.h
+++ b/js/src/frontend/Parser.h
@@ -877,6 +877,12 @@ class ParserBase : public StrictModeGetter
      */
     MOZ_MUST_USE bool extraWarning(unsigned errorNumber, ...);
 
+    /*
+     * If extra warnings are enabled, report the given warning at the given
+     * offset.
+     */
+    MOZ_MUST_USE bool extraWarningAt(uint32_t offset, unsigned errorNumber, ...);
+
     bool isValidStrictBinding(PropertyName* name);
 
     bool warnOnceAboutExprClosure();
@@ -941,7 +947,7 @@ class Parser final : public ParserBase, private JS::AutoGCRooter
     class MOZ_STACK_CLASS PossibleError
     {
       private:
-        enum class ErrorKind { Expression, Destructuring };
+        enum class ErrorKind { Expression, Destructuring, DestructuringWarning };
 
         enum class ErrorState { None, Pending };
 
@@ -956,11 +962,12 @@ class Parser final : public ParserBase, private JS::AutoGCRooter
         Parser<ParseHandler>& parser_;
         Error exprError_;
         Error destructuringError_;
+        Error destructuringWarning_;
 
         // Returns the error report.
         Error& error(ErrorKind kind);
 
-        // Return true if an error is pending without reporting
+        // Return true if an error is pending without reporting.
         bool hasError(ErrorKind kind);
 
         // Resolve any pending error.
@@ -972,7 +979,11 @@ class Parser final : public ParserBase, private JS::AutoGCRooter
 
         // If there is a pending error, report it and return false, otherwise
         // return true.
-        bool checkForError(ErrorKind kind);
+        MOZ_MUST_USE bool checkForError(ErrorKind kind);
+
+        // If there is a pending warning, report it and return either false or
+        // true depending on the werror option, otherwise return true.
+        MOZ_MUST_USE bool checkForWarning(ErrorKind kind);
 
         // Transfer an existing error to another instance.
         void transferErrorTo(ErrorKind kind, PossibleError* other);
@@ -980,23 +991,33 @@ class Parser final : public ParserBase, private JS::AutoGCRooter
       public:
         explicit PossibleError(Parser<ParseHandler>& parser);
 
+        // Return true if a pending destructuring error is present.
+        bool hasPendingDestructuringError();
+
         // Set a pending destructuring error. Only a single error may be set
         // per instance, i.e. subsequent calls to this method are ignored and
         // won't overwrite the existing pending error.
         void setPendingDestructuringErrorAt(const TokenPos& pos, unsigned errorNumber);
 
+        // Set a pending destructuring warning. Only a single warning may be
+        // set per instance, i.e. subsequent calls to this method are ignored
+        // and won't overwrite the existing pending warning.
+        void setPendingDestructuringWarningAt(const TokenPos& pos, unsigned errorNumber);
+
         // Set a pending expression error. Only a single error may be set per
         // instance, i.e. subsequent calls to this method are ignored and won't
         // overwrite the existing pending error.
         void setPendingExpressionErrorAt(const TokenPos& pos, unsigned errorNumber);
 
-        // If there is a pending destructuring error, report it and return
-        // false, otherwise return true. Clears any pending expression error.
-        bool checkForDestructuringError();
+        // If there is a pending destructuring error or warning, report it and
+        // return false, otherwise return true. Clears any pending expression
+        // error.
+        MOZ_MUST_USE bool checkForDestructuringErrorOrWarning();
 
         // If there is a pending expression error, report it and return false,
-        // otherwise return true. Clears any pending destructuring error.
-        bool checkForExpressionError();
+        // otherwise return true. Clears any pending destructuring error or
+        // warning.
+        MOZ_MUST_USE bool checkForExpressionError();
 
         // Pass pending errors between possible error instances. This is useful
         // for extending the lifetime of a pending error beyond the scope of
@@ -1496,18 +1517,10 @@ class Parser final : public ParserBase, private JS::AutoGCRooter
     Node objectBindingPattern(DeclarationKind kind, YieldHandling yieldHandling);
     Node arrayBindingPattern(DeclarationKind kind, YieldHandling yieldHandling);
 
-    // Top-level entrypoint into destructuring assignment pattern checking and
-    // name-analyzing.
-    bool checkDestructuringAssignmentPattern(Node pattern,
-                                             PossibleError* possibleError = nullptr);
-
-    // Recursive methods for checking/name-analyzing subcomponents of an
-    // destructuring assignment pattern.  The array/object methods *must* be
-    // passed arrays or objects.  The name method may be passed anything but
-    // will report an error if not passed a name.
-    bool checkDestructuringAssignmentArray(Node arrayPattern);
-    bool checkDestructuringAssignmentObject(Node objectPattern);
-    bool checkDestructuringAssignmentName(Node expr);
+    void checkDestructuringAssignmentTarget(Node expr, TokenPos exprPos,
+                                            PossibleError* possibleError);
+    void checkDestructuringAssignmentElement(Node expr, TokenPos exprPos,
+                                             PossibleError* possibleError);
 
     Node newNumber(const Token& tok) {
         return handler.newNumber(tok.number(), tok.decimalPoint(), tok.pos);