1 files changed, 42 insertions, 2 deletions

diff --git a/js/src/vm/SharedStencil.h b/js/src/vm/SharedStencil.h
index 58666919dc..a402895bd6 100644
--- a/js/src/vm/SharedStencil.h
+++ b/js/src/vm/SharedStencil.h
@@ -789,7 +789,11 @@ using SharedImmutableScriptDataTable =
                      SharedImmutableScriptData::Hasher, SystemAllocPolicy>;
 
 struct MemberInitializers {
+#ifdef ENABLE_DECORATORS
+  static constexpr size_t NumBits = 30;
+#else
   static constexpr size_t NumBits = 31;
+#endif
   static constexpr uint32_t MaxInitializers = BitMask(NumBits);
 
 #ifdef DEBUG
@@ -798,20 +802,37 @@ struct MemberInitializers {
 
   bool hasPrivateBrand : 1;
 
+#ifdef ENABLE_DECORATORS
+  bool hasDecorators : 1;
+#endif
+
   // This struct will eventually have a vector of constant values for optimizing
   // field initializers.
   uint32_t numMemberInitializers : NumBits;
 
-  MemberInitializers(bool hasPrivateBrand, uint32_t numMemberInitializers)
+  MemberInitializers(bool hasPrivateBrand,
+#ifdef ENABLE_DECORATORS
+                     bool hasDecorators,
+#endif
+                     uint32_t numMemberInitializers)
       :
 #ifdef DEBUG
         valid(true),
 #endif
         hasPrivateBrand(hasPrivateBrand),
+#ifdef ENABLE_DECORATORS
+        hasDecorators(hasDecorators),
+#endif
         numMemberInitializers(numMemberInitializers) {
+#ifdef ENABLE_DECORATORS
+    MOZ_ASSERT(
+        this->numMemberInitializers == numMemberInitializers,
+        "numMemberInitializers should easily fit in the 30-bit bitfield");
+#else
     MOZ_ASSERT(
         this->numMemberInitializers == numMemberInitializers,
         "numMemberInitializers should easily fit in the 31-bit bitfield");
+#endif
   }
 
   static MemberInitializers Invalid() { return MemberInitializers(); }
@@ -820,17 +841,33 @@ struct MemberInitializers {
   // fields. This is used when we elide the trivial data but still need a valid
   // set to stop scope walking.
   static const MemberInitializers& Empty() {
-    static const MemberInitializers zeroInitializers(false, 0);
+    static const MemberInitializers zeroInitializers(false,
+#ifdef ENABLE_DECORATORS
+                                                     false,
+#endif
+                                                     0);
     return zeroInitializers;
   }
 
   uint32_t serialize() const {
+#ifdef ENABLE_DECORATORS
+    auto serialised = (hasPrivateBrand << (NumBits + 1)) |
+                      hasDecorators << NumBits | numMemberInitializers;
+    return serialised;
+#else
     return (hasPrivateBrand << NumBits) | numMemberInitializers;
+#endif
   }
 
   static MemberInitializers deserialize(uint32_t bits) {
+#ifdef ENABLE_DECORATORS
+    return MemberInitializers((bits & Bit(NumBits + 1)) != 0,
+                              (bits & Bit(NumBits)) != 0,
+                              bits & BitMask(NumBits));
+#else
     return MemberInitializers((bits & Bit(NumBits)) != 0,
                               bits & BitMask(NumBits));
+#endif
   }
 
  private:
@@ -840,6 +877,9 @@ struct MemberInitializers {
         valid(false),
 #endif
         hasPrivateBrand(false),
+#ifdef ENABLE_DECORATORS
+        hasDecorators(false),
+#endif
         numMemberInitializers(0) {
   }
 };