Bug 1007878 part 2. Add a C++ type to represent MozMap. r=khuey

dom/bindings/BindingUtils.h

@@ -31,6 +31,7 @@
 #include "qsObjectHelper.h"
 #include "xpcpublic.h"
 #include "nsIVariant.h"
+#include "pldhash.h" // For PLDHashOperator
 
 #include "nsWrapperCacheInlines.h"
 
@@ -43,6 +44,7 @@ xpc_qsUnwrapArgImpl(JSContext* cx, JS::Handle<JS::Value> v, const nsIID& iid, vo
 
 namespace mozilla {
 namespace dom {
+template<typename DataType> class MozMap;
 
 struct SelfRef
 {
@@ -1977,6 +1979,33 @@ public:
   }
 };
 
+// XXXbz It's not clear whether it's better to add a pldhash dependency here
+// (for PLDHashOperator) or add a BindingUtils.h dependency (for
+// SequenceTracer) to MozMap.h...
+template<typename T>
+static PLDHashOperator
+TraceMozMapValue(T* aValue, void* aClosure)
+{
+  JSTracer* trc = static_cast<JSTracer*>(aClosure);
+  // Act like it's a one-element sequence to leverage all that infrastructure.
+  SequenceTracer<T>::TraceSequence(trc, aValue, aValue + 1);
+  return PL_DHASH_NEXT;
+}
+
+// sequence<MozMap>
+template<typename T>
+class SequenceTracer<MozMap<T>, false, false, false>
+{
+  explicit SequenceTracer() MOZ_DELETE; // Should never be instantiated
+
+public:
+  static void TraceSequence(JSTracer* trc, MozMap<T>* seqp, MozMap<T>* end) {
+    for (; seqp != end; ++seqp) {
+      seqp->EnumerateValues(TraceMozMapValue<T>, trc);
+    }
+  }
+};
+
 template<typename T>
 void DoTraceSequence(JSTracer* trc, FallibleTArray<T>& seq)
 {
@@ -2050,6 +2079,58 @@ public:
   SequenceType mSequenceType;
 };
 
+// Rooter class for MozMap; this is what we mostly use in the codegen.
+template<typename T>
+class MOZ_STACK_CLASS MozMapRooter : private JS::CustomAutoRooter
+{
+public:
+  MozMapRooter(JSContext *aCx, MozMap<T>* aMozMap
+               MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
+    : JS::CustomAutoRooter(aCx MOZ_GUARD_OBJECT_NOTIFIER_PARAM_TO_PARENT),
+      mMozMap(aMozMap),
+      mMozMapType(eMozMap)
+  {
+  }
+
+  MozMapRooter(JSContext *aCx, Nullable<MozMap<T>>* aMozMap
+                 MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
+    : JS::CustomAutoRooter(aCx MOZ_GUARD_OBJECT_NOTIFIER_PARAM_TO_PARENT),
+      mNullableMozMap(aMozMap),
+      mMozMapType(eNullableMozMap)
+  {
+  }
+
+private:
+  enum MozMapType {
+    eMozMap,
+    eNullableMozMap
+  };
+
+  virtual void trace(JSTracer *trc) MOZ_OVERRIDE
+  {
+    MozMap<T>* mozMap;
+    if (mMozMapType == eMozMap) {
+      mozMap = mMozMap;
+    } else {
+      MOZ_ASSERT(mMozMapType == eNullableMozMap);
+      if (mNullableMozMap->IsNull()) {
+        // Nothing to do
+        return;
+      }
+      mozMap = &mNullableMozMap->Value();
+    }
+
+    mozMap->EnumerateValues(TraceMozMapValue<T>, trc);
+  }
+
+  union {
+    MozMap<T>* mMozMap;
+    Nullable<MozMap<T>>* mNullableMozMap;
+  };
+
+  MozMapType mMozMapType;
+};
+
 template<typename T>
 class MOZ_STACK_CLASS RootedUnion : public T,
                                     private JS::CustomAutoRooter

dom/bindings/Codegen.py

@@ -39,7 +39,7 @@ def toBindingNamespace(arg):
 
 
 def isTypeCopyConstructible(type):
-    # Nullable and sequence stuff doesn't affect copy/constructibility
+    # Nullable and sequence stuff doesn't affect copy-constructibility
     type = type.unroll()
     return (type.isPrimitive() or type.isString() or type.isEnum() or
             (type.isUnion() and
@@ -1028,7 +1028,7 @@ class CGHeaders(CGWrapper):
                 headerSet.add(self.getDeclarationFilename(unrolled.inner))
             elif unrolled.isCallback():
                 # Callbacks are both a type and an object
-                headerSet.add(self.getDeclarationFilename(t.unroll()))
+                headerSet.add(self.getDeclarationFilename(unrolled))
             elif unrolled.isFloat() and not unrolled.isUnrestricted():
                 # Restricted floats are tested for finiteness
                 bindingHeaders.add("mozilla/FloatingPoint.h")
@@ -1038,6 +1038,14 @@ class CGHeaders(CGWrapper):
                 declareIncludes.add(filename)
             elif unrolled.isPrimitive():
                 bindingHeaders.add("mozilla/dom/PrimitiveConversions.h")
+            elif unrolled.isMozMap():
+                if dictionary or jsImplementedDescriptors:
+                    declareIncludes.add("mozilla/dom/MozMap.h")
+                else:
+                    bindingHeaders.add("mozilla/dom/MozMap.h")
+                # Also add headers for the type the MozMap is
+                # parametrized over, if needed.
+                addHeadersForType((t.inner, descriptor, dictionary))
 
         map(addHeadersForType,
             getAllTypes(descriptors + callbackDescriptors, dictionaries,
@@ -1153,6 +1161,8 @@ def UnionTypes(descriptors, dictionaries, callbacks, config):
         assert not descriptor or not dictionary
 
         t = t.unroll()
+        while t.isMozMap():
+            t = t.inner.unroll()
         if not t.isUnion():
             continue
         name = str(t)
@@ -1163,10 +1173,10 @@ def UnionTypes(descriptors, dictionaries, callbacks, config):
             owningUnionStructs[name] = CGUnionStruct(t, providers[0],
                                                      ownsMembers=True)
 
-            for f in t.flatMemberTypes:
-                f = f.unroll()
+            def addHeadersForType(f):
                 if f.nullable():
                     headers.add("mozilla/dom/Nullable.h")
+                f = f.unroll()
                 if f.isInterface():
                     if f.isSpiderMonkeyInterface():
                         headers.add("jsfriendapi.h")
@@ -1202,6 +1212,14 @@ def UnionTypes(descriptors, dictionaries, callbacks, config):
                     # the right header to be able to Release() in our inlined
                     # code.
                     headers.add(CGHeaders.getDeclarationFilename(f))
+                elif f.isMozMap():
+                    headers.add("mozilla/dom/MozMap.h")
+                    # And add headers for the type we're parametrized over
+                    addHeadersForType(f.inner)
+
+            for f in t.flatMemberTypes:
+                assert not f.nullable()
+                addHeadersForType(f)
 
     return (headers, implheaders, declarations,
             CGList(SortedDictValues(unionStructs) +
@@ -1230,7 +1248,7 @@ def UnionConversions(descriptors, dictionaries, callbacks, config):
         if name not in unionConversions:
             providers = getRelevantProviders(descriptor, config)
             unionConversions[name] = CGUnionConversionStruct(t, providers[0])
-            for f in t.flatMemberTypes:
+            def addHeadersForType(f, providers):
                 f = f.unroll()
                 if f.isInterface():
                     if f.isSpiderMonkeyInterface():
@@ -1257,6 +1275,13 @@ def UnionConversions(descriptors, dictionaries, callbacks, config):
                     headers.add(CGHeaders.getDeclarationFilename(f.inner))
                 elif f.isPrimitive():
                     headers.add("mozilla/dom/PrimitiveConversions.h")
+                elif f.isMozMap():
+                    headers.add("mozilla/dom/MozMap.h")
+                    # And the internal type of the MozMap
+                    addHeadersForType(f.inner, providers)
+
+            for f in t.flatMemberTypes:
+                addHeadersForType(f, providers)
 
     return (headers,
             CGWrapper(CGList(SortedDictValues(unionConversions), "\n"),
@@ -10955,6 +10980,8 @@ class CGForwardDeclarations(CGWrapper):
                 # since we don't know which one we might want
                 builder.addInMozillaDom(CGUnionStruct.unionTypeName(t, False))
                 builder.addInMozillaDom(CGUnionStruct.unionTypeName(t, True))
+            elif t.isMozMap():
+                forwardDeclareForType(t.inner, workerness)
             # Don't need to do anything for void, primitive, string, any or object.
             # There may be some other cases we are missing.
 
@@ -11058,6 +11085,8 @@ class CGBindingRoot(CGThing):
         def checkForXPConnectImpls(typeInfo):
             type, _, _ = typeInfo
             type = type.unroll()
+            while type.isMozMap():
+                type = type.inner.unroll()
             if not type.isInterface() or not type.isGeckoInterface():
                 return False
             try:

dom/bindings/MozMap.h

@@ -0,0 +1,132 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+/**
+ * Class for representing MozMap arguments.  This is an nsTHashtable
+ * under the hood, but we don't want to leak that implementation
+ * detail.
+ */
+
+#ifndef mozilla_dom_MozMap_h
+#define mozilla_dom_MozMap_h
+
+#include "nsTHashtable.h"
+#include "nsHashKeys.h"
+#include "nsStringGlue.h"
+#include "nsTArray.h"
+#include "mozilla/Move.h"
+
+namespace mozilla {
+namespace dom {
+
+namespace binding_detail {
+template<typename DataType>
+class MozMapEntry : public nsStringHashKey
+{
+public:
+  MozMapEntry(const nsAString* aKeyTypePointer)
+    : nsStringHashKey(aKeyTypePointer)
+  {
+  }
+
+  // Move constructor so we can do MozMaps of MozMaps.
+  MozMapEntry(MozMapEntry<DataType>&& aOther)
+    : nsStringHashKey(aOther),
+      mData(Move(aOther.mData))
+  {
+  }
+
+  DataType mData;
+};
+} // namespace binding_detail
+
+template<typename DataType>
+class MozMap : protected nsTHashtable<binding_detail::MozMapEntry<DataType>>
+{
+public:
+  typedef typename binding_detail::MozMapEntry<DataType> EntryType;
+  typedef nsTHashtable<EntryType> Base;
+  typedef MozMap<DataType> SelfType;
+
+  MozMap()
+  {
+  }
+
+  // Move constructor so we can do MozMap of MozMap.
+  MozMap(SelfType&& aOther) :
+    Base(Move(aOther))
+  {
+  }
+
+  // The return value is only safe to use until an AddEntry call.
+  const DataType& Get(const nsAString& aKey) const
+  {
+    const EntryType* ent = this->GetEntry(aKey);
+    MOZ_ASSERT(ent, "Why are you using a key we didn't claim to have?");
+    return ent->mData;
+  }
+
+  // The return value is only safe to use until an AddEntry call.
+  const DataType* GetIfExists(const nsAString& aKey) const
+  {
+    const EntryType* ent = this->GetEntry(aKey);
+    if (!ent) {
+      return nullptr;
+    }
+    return &ent->mData;
+  }
+
+  void GetKeys(nsTArray<nsString>& aKeys) const {
+    // Sadly, EnumerateEntries is not a const method
+    const_cast<SelfType*>(this)->EnumerateEntries(KeyEnumerator, &aKeys);
+  }
+
+  // XXXbz we expose this generic enumerator for tracing.  Otherwise we'd end up
+  // with a dependency on BindingUtils.h here for the SequenceTracer bits.
+  typedef PLDHashOperator (* Enumerator)(DataType* aValue, void* aClosure);
+  void EnumerateValues(Enumerator aEnumerator, void *aClosure)
+  {
+    ValueEnumClosure args = { aEnumerator, aClosure };
+    this->EnumerateEntries(ValueEnumerator, &args);
+  }
+
+  DataType* AddEntry(const nsAString& aKey) NS_WARN_UNUSED_RESULT
+  {
+    // XXXbz can't just use fallible_t() because our superclass has a
+    // private typedef by that name.
+    EntryType* ent = this->PutEntry(aKey, mozilla::fallible_t());
+    if (!ent) {
+      return nullptr;
+    }
+    return &ent->mData;
+  }
+
+private:
+  static PLDHashOperator
+  KeyEnumerator(EntryType* aEntry, void* aClosure)
+  {
+    nsTArray<nsString>& keys = *static_cast<nsTArray<nsString>*>(aClosure);
+    keys.AppendElement(aEntry->GetKey());
+    return PL_DHASH_NEXT;
+  }
+
+  struct ValueEnumClosure {
+    Enumerator mEnumerator;
+    void* mClosure;
+  };
+
+  static PLDHashOperator
+  ValueEnumerator(EntryType* aEntry, void* aClosure)
+  {
+    ValueEnumClosure* enumClosure = static_cast<ValueEnumClosure*>(aClosure);
+    return enumClosure->mEnumerator(&aEntry->mData, enumClosure->mClosure);
+  }
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_MozMap_h

dom/bindings/Nullable.h

@@ -9,6 +9,7 @@
 
 #include "mozilla/Assertions.h"
 #include "nsTArrayForwardDeclare.h"
+#include "mozilla/Move.h"
 
 namespace mozilla {
 namespace dom {
@@ -33,6 +34,22 @@ public:
     , mValue(aValue)
   {}
 
+  explicit Nullable(Nullable<T>&& aOther)
+    : mIsNull(aOther.mIsNull)
+    , mValue(mozilla::Move(aOther.mValue))
+  {}
+
+  Nullable(const Nullable<T>& aOther)
+    : mIsNull(aOther.mIsNull)
+    , mValue(aOther.mValue)
+  {}
+
+  void operator=(const Nullable<T>& aOther)
+  {
+    mIsNull = aOther.mIsNull;
+    mValue = aOther.mValue;
+  }
+
   void SetValue(T aValue) {
     mValue = aValue;
     mIsNull = false;

dom/bindings/TypedArray.h

@@ -12,6 +12,7 @@
 #include "js/RootingAPI.h"
 #include "js/TracingAPI.h"
 #include "mozilla/Attributes.h"
+#include "mozilla/Move.h"
 #include "mozilla/dom/BindingDeclarations.h"
 #include "nsWrapperCache.h"
 
@@ -29,6 +30,12 @@ protected:
   {
   }
 
+  explicit TypedArrayObjectStorage(TypedArrayObjectStorage&& aOther)
+    : mObj(aOther.mObj)
+  {
+    aOther.mObj = nullptr;
+  }
+
 public:
   inline void TraceSelf(JSTracer* trc)
   {
@@ -62,6 +69,15 @@ struct TypedArray_base : public TypedArrayObjectStorage {
     mObj = nullptr;
   }
 
+  explicit TypedArray_base(TypedArray_base&& aOther)
+    : TypedArrayObjectStorage(Move(aOther)),
+      mData(aOther.mData),
+      mLength(aOther.mLength)
+  {
+    aOther.mData = nullptr;
+    aOther.mLength = 0;
+  }
+
 private:
   T* mData;
   uint32_t mLength;
@@ -123,6 +139,11 @@ struct TypedArray : public TypedArray_base<T,UnboxArray> {
     TypedArray_base<T,UnboxArray>()
   {}
 
+  explicit TypedArray(TypedArray&& aOther)
+    : TypedArray_base<T,UnboxArray>(Move(aOther))
+  {
+  }
+
   static inline JSObject*
   Create(JSContext* cx, nsWrapperCache* creator, uint32_t length,
          const T* data = nullptr) {

dom/bindings/moz.build

@@ -24,6 +24,7 @@ EXPORTS.mozilla.dom += [
     'Errors.msg',
     'Exceptions.h',
     'JSSlots.h',
+    'MozMap.h',
     'NonRefcountedDOMObject.h',
     'Nullable.h',
     'OwningNonNull.h',

xpcom/glue/nsTHashtable.h

@@ -385,7 +385,7 @@ nsTHashtable<EntryType>::nsTHashtable(
 {
   // aOther shouldn't touch mTable after this, because we've stolen the table's
   // pointers but not overwitten them.
-  MOZ_MAKE_MEM_UNDEFINED(aOther.mTable, sizeof(aOther.mTable));
+  MOZ_MAKE_MEM_UNDEFINED(&aOther.mTable, sizeof(aOther.mTable));
 
   // Indicate that aOther is not initialized.  This will make its destructor a
   // nop, which is what we want.