Bug 983228. Add a sequence tracer for sequences of unions. r=baku

dom/bindings/BindingDeclarations.h

@@ -47,6 +47,12 @@ protected:
 struct AllTypedArraysBase {
 };
 
+// Struct that serves as a base class for all owning unions.
+// Particularly useful so we can use IsBaseOf to detect owning union
+// template arguments.
+struct AllOwningUnionBase {
+};
+
 
 struct EnumEntry {
   const char* value;

dom/bindings/BindingUtils.h

@@ -1657,7 +1657,8 @@ public:
 // sequence types.
 template<typename T,
          bool isDictionary=IsBaseOf<DictionaryBase, T>::value,
-         bool isTypedArray=IsBaseOf<AllTypedArraysBase, T>::value>
+         bool isTypedArray=IsBaseOf<AllTypedArraysBase, T>::value,
+         bool isOwningUnion=IsBaseOf<AllOwningUnionBase, T>::value>
 class SequenceTracer
 {
   explicit SequenceTracer() MOZ_DELETE; // Should never be instantiated
@@ -1665,7 +1666,7 @@ class SequenceTracer
 
 // sequence<object> or sequence<object?>
 template<>
-class SequenceTracer<JSObject*, false, false>
+class SequenceTracer<JSObject*, false, false, false>
 {
   explicit SequenceTracer() MOZ_DELETE; // Should never be instantiated
 
@@ -1679,7 +1680,7 @@ public:
 
 // sequence<any>
 template<>
-class SequenceTracer<JS::Value, false, false>
+class SequenceTracer<JS::Value, false, false, false>
 {
   explicit SequenceTracer() MOZ_DELETE; // Should never be instantiated
 
@@ -1693,7 +1694,7 @@ public:
 
 // sequence<sequence<T>>
 template<typename T>
-class SequenceTracer<Sequence<T>, false, false>
+class SequenceTracer<Sequence<T>, false, false, false>
 {
   explicit SequenceTracer() MOZ_DELETE; // Should never be instantiated
 
@@ -1707,7 +1708,7 @@ public:
 
 // sequence<sequence<T>> as return value
 template<typename T>
-class SequenceTracer<nsTArray<T>, false, false>
+class SequenceTracer<nsTArray<T>, false, false, false>
 {
   explicit SequenceTracer() MOZ_DELETE; // Should never be instantiated
 
@@ -1721,7 +1722,7 @@ public:
 
 // sequence<someDictionary>
 template<typename T>
-class SequenceTracer<T, true, false>
+class SequenceTracer<T, true, false, false>
 {
   explicit SequenceTracer() MOZ_DELETE; // Should never be instantiated
 
@@ -1735,7 +1736,7 @@ public:
 
 // sequence<SomeTypedArray>
 template<typename T>
-class SequenceTracer<T, false, true>
+class SequenceTracer<T, false, true, false>
 {
   explicit SequenceTracer() MOZ_DELETE; // Should never be instantiated
 
@@ -1747,9 +1748,23 @@ public:
   }
 };
 
+// sequence<SomeOwningUnion>
+template<typename T>
+class SequenceTracer<T, false, false, true>
+{
+  explicit SequenceTracer() MOZ_DELETE; // Should never be instantiated
+
+public:
+  static void TraceSequence(JSTracer* trc, T* arrayp, T* end) {
+    for (; arrayp != end; ++arrayp) {
+      arrayp->TraceUnion(trc);
+    }
+  }
+};
+
 // sequence<T?> with T? being a Nullable<T>
 template<typename T>
-class SequenceTracer<Nullable<T>, false, false>
+class SequenceTracer<Nullable<T>, false, false, false>
 {
   explicit SequenceTracer() MOZ_DELETE; // Should never be instantiated
 

dom/bindings/Codegen.py

@@ -7201,7 +7201,9 @@ class CGUnionStruct(CGThing):
             disallowCopyConstruction = True
 
         friend="  friend class %sArgument;\n" % str(self.type) if not self.ownsMembers else ""
+        bases = [ClassBase("AllOwningUnionBase")] if self.ownsMembers else []
         return CGClass(selfName,
+                       bases=bases,
                        members=members,
                        constructors=constructors,
                        methods=methods,

dom/bindings/test/TestBindingHeader.h

@@ -567,6 +567,7 @@ public:
   void PassNullableUnionWithDefaultValue12(const Nullable<UnrestrictedFloatOrString>& arg);
 
   void PassSequenceOfUnions(const Sequence<OwningCanvasPatternOrCanvasGradient>&);
+  void PassSequenceOfUnions2(JSContext*, const Sequence<OwningObjectOrLong>&);
   void PassVariadicUnion(const Sequence<OwningCanvasPatternOrCanvasGradient>&);
 
   void PassSequenceOfNullableUnions(const Sequence<Nullable<OwningCanvasPatternOrCanvasGradient>>&);

dom/bindings/test/TestCodeGen.webidl

@@ -522,6 +522,7 @@ interface TestInterface {
   void passNullableUnionWithDefaultValue12(optional (unrestricted float or DOMString)? arg = null);
 
   void passSequenceOfUnions(sequence<(CanvasPattern or CanvasGradient)> arg);
+  void passSequenceOfUnions2(sequence<(object or long)> arg);
   void passVariadicUnion((CanvasPattern or CanvasGradient)... arg);
 
   void passSequenceOfNullableUnions(sequence<(CanvasPattern or CanvasGradient)?> arg);

dom/bindings/test/TestExampleGen.webidl

@@ -415,6 +415,7 @@ interface TestExampleInterface {
   void passNullableUnionWithDefaultValue12(optional (unrestricted float or DOMString)? arg = null);
 
   void passSequenceOfUnions(sequence<(CanvasPattern or CanvasGradient)> arg);
+  void passSequenceOfUnions2(sequence<(object or long)> arg);
   void passVariadicUnion((CanvasPattern or CanvasGradient)... arg);
 
   void passSequenceOfNullableUnions(sequence<(CanvasPattern or CanvasGradient)?> arg);

dom/bindings/test/TestJSImplGen.webidl

@@ -436,6 +436,7 @@ interface TestJSImplInterface {
   void passNullableUnionWithDefaultValue12(optional (unrestricted float or DOMString)? arg = null);
 
   void passSequenceOfUnions(sequence<(CanvasPattern or CanvasGradient)> arg);
+  void passSequenceOfUnions2(sequence<(object or long)> arg);
   void passVariadicUnion((CanvasPattern or CanvasGradient)... arg);
 
   void passSequenceOfNullableUnions(sequence<(CanvasPattern or CanvasGradient)?> arg);