Bug 1257979 - Use a GCHashSet for a hash in the JSON stringifying algorithm. r=sfink

--HG--
extra : rebase_source : c6e2b22de7467ac4c99fa6e010a88c2f2ca1d981

js/public/GCHashTable.h

@@ -303,6 +303,7 @@ class MutableGCHashSetOperations
     bool init(uint32_t len = 16) { return set().init(len); }
     void clear()                 { set().clear(); }
     void finish()                { set().finish(); }
+    void remove(Ptr p)           { set().remove(p); }
     void remove(const Lookup& l) { set().remove(l); }
 
     template<typename TInput>

js/public/Id.h

@@ -27,11 +27,15 @@
 #include "js/TypeDecls.h"
 #include "js/Utility.h"
 
+namespace js {
+template <typename T> struct DefaultHasher;
+} // namespace js
+
 struct jsid
 {
     size_t asBits;
-    bool operator==(jsid rhs) const { return asBits == rhs.asBits; }
+    bool operator==(const jsid& rhs) const { return asBits == rhs.asBits; }
-    bool operator!=(jsid rhs) const { return asBits != rhs.asBits; }
+    bool operator!=(const jsid& rhs) const { return asBits != rhs.asBits; }
 } JS_HAZ_GC_POINTER;
 #define JSID_BITS(id) (id.asBits)
 
@@ -168,6 +172,18 @@ extern JS_PUBLIC_DATA(const JS::HandleId) JSID_EMPTYHANDLE;
 
 namespace js {
 
+template <>
+struct DefaultHasher<jsid>
+{
+    typedef jsid Lookup;
+    static HashNumber hash(jsid id) {
+        return JSID_BITS(id);
+    }
+    static bool match(jsid id1, jsid id2) {
+        return id1 == id2;
+    }
+};
+
 template <>
 struct GCPolicy<jsid>
 {

js/src/builtin/ModuleObject.h

@@ -13,6 +13,7 @@
 #include "gc/Zone.h"
 
 #include "js/GCVector.h"
+#include "js/Id.h"
 
 #include "vm/NativeObject.h"
 #include "vm/ProxyObject.h"
@@ -121,7 +122,7 @@ class IndirectBindingMap
         RelocatablePtrShape shape;
     };
 
-    typedef HashMap<jsid, Binding, JsidHasher, ZoneAllocPolicy> Map;
+    typedef HashMap<jsid, Binding, DefaultHasher<jsid>, ZoneAllocPolicy> Map;
 
     Map map_;
 };

js/src/jsatom.h

@@ -31,17 +31,6 @@ HashId(jsid id)
     return mozilla::HashGeneric(JSID_BITS(id));
 }
 
-struct JsidHasher
-{
-    typedef jsid Lookup;
-    static HashNumber hash(const Lookup& l) {
-        return HashNumber(JSID_BITS(l));
-    }
-    static bool match(const jsid& id, const Lookup& l) {
-        return id == l;
-    }
-};
-
 /*
  * Return a printable, lossless char[] representation of a string-type atom.
  * The lifetime of the result matches the lifetime of bytes.

js/src/json.cpp

@@ -635,7 +635,7 @@ js::Stringify(JSContext* cx, MutableHandleValue vp, JSObject* replacer_, Value s
             // is passed in.  If we end up having to add elements past this
             // size, the set will naturally resize to accommodate them.
             const uint32_t MaxInitialSize = 32;
-            HashSet<jsid, JsidHasher> idSet(cx);
+            Rooted<GCHashSet<jsid>> idSet(cx, GCHashSet<jsid>(cx));
             if (!idSet.init(Min(len, MaxInitialSize)))
                 return false;
 

js/src/vm/RegExpObject.cpp

@@ -925,6 +925,9 @@ js::CloneRegExpObject(JSContext* cx, JSObject* obj_)
     if (!currentStatics)
         return nullptr;
 
+    if (!EmptyShape::ensureInitialCustomShape<RegExpObject>(cx, clone))
+        return nullptr;
+
     Rooted<JSAtom*> source(cx, regex->getSource());
 
     RegExpFlag origFlags = regex->getFlags();