Bug 877216. Add CallArgs-like structs for use in DOM specialized getters/setters/methods. r=waldo

dom/bindings/Codegen.py

@@ -5104,7 +5104,7 @@ class CGGenericMethod(CGAbstractBindingMethod):
         return CGIndenter(CGGeneric(
             "const JSJitInfo *info = FUNCTION_VALUE_TO_JITINFO(JS_CALLEE(cx, vp));\n"
             "MOZ_ASSERT(info->type == JSJitInfo::Method);\n"
-            "JSJitMethodOp method = (JSJitMethodOp)info->op;\n"
+            "JSJitMethodOp method = info->method;\n"
             "return method(cx, obj, self, argc, vp);"))
 
 class CGSpecializedMethod(CGAbstractStaticMethod):
@@ -5240,7 +5240,7 @@ class CGGenericGetter(CGAbstractBindingMethod):
         return CGIndenter(CGGeneric(
             "const JSJitInfo *info = FUNCTION_VALUE_TO_JITINFO(JS_CALLEE(cx, vp));\n"
             "MOZ_ASSERT(info->type == JSJitInfo::Getter);\n"
-            "JSJitPropertyOp getter = info->op;\n"
+            "JSJitGetterOp getter = info->getter;\n"
             "return getter(cx, obj, self, vp);"))
 
 class CGSpecializedGetter(CGAbstractStaticMethod):
@@ -5324,7 +5324,7 @@ class CGGenericSetter(CGAbstractBindingMethod):
                 "JS::Value* argv = JS_ARGV(cx, vp);\n"
                 "const JSJitInfo *info = FUNCTION_VALUE_TO_JITINFO(JS_CALLEE(cx, vp));\n"
                 "MOZ_ASSERT(info->type == JSJitInfo::Setter);\n"
-                "JSJitPropertyOp setter = info->op;\n"
+                "JSJitSetterOp setter = info->setter;\n"
                 "if (!setter(cx, obj, self, argv)) {\n"
                 "  return false;\n"
                 "}\n"
@@ -5431,7 +5431,7 @@ class CGMemberJITInfo(CGThing):
                             "")
         return ("\n"
                 "static const JSJitInfo %s = {\n"
-                "  %s,\n"
+                "  { %s },\n"
                 "  %s,\n"
                 "  %s,\n"
                 "  JSJitInfo::%s,\n"
@@ -5445,7 +5445,9 @@ class CGMemberJITInfo(CGThing):
     def define(self):
         if self.member.isAttr():
             getterinfo = ("%s_getterinfo" % self.member.identifier.name)
-            getter = ("(JSJitPropertyOp)get_%s" % self.member.identifier.name)
+            # We need the cast here because JSJitGetterOp has a "void* self"
+            # while we have the right type.
+            getter = ("(JSJitGetterOp)get_%s" % self.member.identifier.name)
             getterinfal = "infallible" in self.descriptor.getExtendedAttributes(self.member, getter=True)
             getterconst = self.member.getExtendedAttribute("Constant")
             getterpure = getterconst or self.member.getExtendedAttribute("Pure")
@@ -5457,7 +5459,9 @@ class CGMemberJITInfo(CGThing):
                                         [self.member.type])
             if not self.member.readonly or self.member.getExtendedAttribute("PutForwards") is not None:
                 setterinfo = ("%s_setterinfo" % self.member.identifier.name)
-                setter = ("(JSJitPropertyOp)set_%s" % self.member.identifier.name)
+                # Actually a JSJitSetterOp, but JSJitGetterOp is first in the
+                # union.
+                setter = ("(JSJitGetterOp)set_%s" % self.member.identifier.name)
                 # Setters are always fallible, since they have to do a typed unwrap.
                 result += self.defineJitInfo(setterinfo, setter, "Setter",
                                              False, False, False,
@@ -5466,8 +5470,8 @@ class CGMemberJITInfo(CGThing):
         if self.member.isMethod():
             methodinfo = ("%s_methodinfo" % self.member.identifier.name)
             name = CppKeywords.checkMethodName(self.member.identifier.name)
-            # Actually a JSJitMethodOp, but JSJitPropertyOp by struct definition.
+            # Actually a JSJitMethodOp, but JSJitGetterOp is first in the union.
-            method = ("(JSJitPropertyOp)%s" % name)
+            method = ("(JSJitGetterOp)%s" % name)
 
             # Methods are infallible if they are infallible, have no arguments
             # to unwrap, and have a return type that's infallible to wrap up for

js/public/CallArgs.h

@@ -31,6 +31,7 @@
 
 #include "mozilla/Assertions.h"
 #include "mozilla/Attributes.h"
+#include "mozilla/TypeTraits.h"
 
 #include "jstypes.h"
 
@@ -92,30 +93,50 @@ namespace JS {
  * public interface are meant to be used by embedders!  See inline comments to
  * for details.
  */
-class MOZ_STACK_CLASS CallReceiver
+
+namespace detail {
+
+enum UsedRval { IncludeUsedRval, NoUsedRval };
+
+template<UsedRval WantUsedRval>
+class MOZ_STACK_CLASS UsedRvalBase;
+
+template<>
+class MOZ_STACK_CLASS UsedRvalBase<IncludeUsedRval>
 {
   protected:
-#ifdef DEBUG
     mutable bool usedRval_;
     void setUsedRval() const { usedRval_ = true; }
     void clearUsedRval() const { usedRval_ = false; }
-#else
+};
+
+template<>
+class MOZ_STACK_CLASS UsedRvalBase<NoUsedRval>
+{
+  protected:
     void setUsedRval() const {}
     void clearUsedRval() const {}
+};
+
+template<UsedRval WantUsedRval>
+class MOZ_STACK_CLASS CallReceiverBase : public UsedRvalBase<
+#ifdef DEBUG
+        WantUsedRval
+#else
+        NoUsedRval
 #endif
-
+    >
+{
+  protected:
     Value *argv_;
 
-    friend CallReceiver CallReceiverFromVp(Value *vp);
-    friend CallReceiver CallReceiverFromArgv(Value *argv);
-
   public:
     /*
      * Returns the function being called, as an object.  Must not be called
      * after rval() has been used!
      */
     JSObject &callee() const {
-        MOZ_ASSERT(!usedRval_);
+        MOZ_ASSERT(!this->usedRval_);
         return argv_[-2].toObject();
     }
 
@@ -124,7 +145,7 @@ class MOZ_STACK_CLASS CallReceiver
      * rval() has been used!
      */
     HandleValue calleev() const {
-        MOZ_ASSERT(!usedRval_);
+        MOZ_ASSERT(!this->usedRval_);
         return HandleValue::fromMarkedLocation(&argv_[-2]);
     }
 
@@ -160,7 +181,7 @@ class MOZ_STACK_CLASS CallReceiver
      * fails.
      */
     MutableHandleValue rval() const {
-        setUsedRval();
+        this->setUsedRval();
         return MutableHandleValue::fromMarkedLocation(&argv_[-2]);
     }
 
@@ -171,7 +192,7 @@ class MOZ_STACK_CLASS CallReceiver
     Value *base() const { return argv_ - 2; }
 
     Value *spAfterCall() const {
-        setUsedRval();
+        this->setUsedRval();
         return argv_ - 1;
     }
 
@@ -181,7 +202,7 @@ class MOZ_STACK_CLASS CallReceiver
     // it.  You probably don't want to use these!
 
     void setCallee(Value aCalleev) const {
-        clearUsedRval();
+        this->clearUsedRval();
         argv_[-2] = aCalleev;
     }
 
@@ -194,6 +215,15 @@ class MOZ_STACK_CLASS CallReceiver
     }
 };
 
+} // namespace detail
+
+class MOZ_STACK_CLASS CallReceiver : public detail::CallReceiverBase<detail::IncludeUsedRval>
+{
+  private:
+    friend CallReceiver CallReceiverFromVp(Value *vp);
+    friend CallReceiver CallReceiverFromArgv(Value *argv);
+};
+
 MOZ_ALWAYS_INLINE CallReceiver
 CallReceiverFromArgv(Value *argv)
 {
@@ -233,11 +263,63 @@ CallReceiverFromVp(Value *vp)
  * public interface are meant to be used by embedders!  See inline comments to
  * for details.
  */
-class MOZ_STACK_CLASS CallArgs : public CallReceiver
+namespace detail {
+
+template<UsedRval WantUsedRval>
+class MOZ_STACK_CLASS CallArgsBase :
+        public mozilla::Conditional<WantUsedRval == detail::IncludeUsedRval,
+                                    CallReceiver,
+                                    CallReceiverBase<NoUsedRval> >::Type
 {
   protected:
     unsigned argc_;
 
+  public:
+    /* Returns the number of arguments. */
+    unsigned length() const { return argc_; }
+
+    /* Returns the i-th zero-indexed argument. */
+    Value &operator[](unsigned i) const {
+        MOZ_ASSERT(i < argc_);
+        return this->argv_[i];
+    }
+
+    /* Returns a mutable handle for the i-th zero-indexed argument. */
+    MutableHandleValue handleAt(unsigned i) const {
+        MOZ_ASSERT(i < argc_);
+        return MutableHandleValue::fromMarkedLocation(&this->argv_[i]);
+    }
+
+    /*
+     * Returns the i-th zero-indexed argument, or |undefined| if there's no
+     * such argument.
+     */
+    Value get(unsigned i) const {
+        return i < length() ? this->argv_[i] : UndefinedValue();
+    }
+
+    /*
+     * Returns true if the i-th zero-indexed argument is present and is not
+     * |undefined|.
+     */
+    bool hasDefined(unsigned i) const {
+        return i < argc_ && !this->argv_[i].isUndefined();
+    }
+
+  public:
+    // These methods are publicly exposed, but we're less sure of the interface
+    // here than we'd like (because they're hackish and drop assertions).  Try
+    // to avoid using these if you can.
+
+    Value *array() const { return this->argv_; }
+    Value *end() const { return this->argv_ + argc_; }
+};
+
+} // namespace detail
+
+class MOZ_STACK_CLASS CallArgs : public detail::CallArgsBase<detail::IncludeUsedRval>
+{
+  private:
     friend CallArgs CallArgsFromVp(unsigned argc, Value *vp);
     friend CallArgs CallArgsFromSp(unsigned argc, Value *sp);
 
@@ -249,45 +331,6 @@ class MOZ_STACK_CLASS CallArgs : public CallReceiver
         return args;
     }
 
-  public:
-    /* Returns the number of arguments. */
-    unsigned length() const { return argc_; }
-
-    /* Returns the i-th zero-indexed argument. */
-    Value &operator[](unsigned i) const {
-        MOZ_ASSERT(i < argc_);
-        return argv_[i];
-    }
-
-    /* Returns a mutable handle for the i-th zero-indexed argument. */
-    MutableHandleValue handleAt(unsigned i) const {
-        MOZ_ASSERT(i < argc_);
-        return MutableHandleValue::fromMarkedLocation(&argv_[i]);
-    }
-
-    /*
-     * Returns the i-th zero-indexed argument, or |undefined| if there's no
-     * such argument.
-     */
-    Value get(unsigned i) const {
-        return i < length() ? argv_[i] : UndefinedValue();
-    }
-
-    /*
-     * Returns true if the i-th zero-indexed argument is present and is not
-     * |undefined|.
-     */
-    bool hasDefined(unsigned i) const {
-        return i < argc_ && !argv_[i].isUndefined();
-    }
-
-  public:
-    // These methods are publicly exposed, but we're less sure of the interface
-    // here than we'd like (because they're hackish and drop assertions).  Try
-    // to avoid using these if you can.
-
-    Value *array() const { return argv_; }
-    Value *end() const { return argv_ + argc_; }
 };
 
 MOZ_ALWAYS_INLINE CallArgs

js/src/ion/CodeGenerator.cpp

@@ -1453,7 +1453,7 @@ CodeGenerator::visitCallDOMNative(LCallDOMNative *call)
     masm.passABIArg(argPrivate);
     masm.passABIArg(argArgc);
     masm.passABIArg(argVp);
-    masm.callWithABI(JS_FUNC_TO_DATA_PTR(void *, target->jitInfo()->op));
+    masm.callWithABI(JS_FUNC_TO_DATA_PTR(void *, target->jitInfo()->method));
 
     if (target->jitInfo()->isInfallible) {
         masm.loadValue(Address(StackPointer, IonDOMMethodExitFrameLayout::offsetOfResult()),

js/src/ion/IonBuilder.cpp

@@ -7791,7 +7791,8 @@ IonBuilder::jsop_setprop(HandlePropertyName name)
         // properties.
         RootedFunction setter(cx, commonSetter);
         if (isDOM && TestShouldDOMCall(cx, objTypes, setter, JSJitInfo::Setter)) {
-            MSetDOMProperty *set = MSetDOMProperty::New(setter->jitInfo()->op, obj, value);
+            JS_ASSERT(setter->jitInfo()->type == JSJitInfo::Setter);
+            MSetDOMProperty *set = MSetDOMProperty::New(setter->jitInfo()->setter, obj, value);
             if (!set)
                 return false;
 

js/src/ion/MIR.h

@@ -6586,9 +6586,9 @@ class MSetDOMProperty
   : public MAryInstruction<2>,
     public MixPolicy<ObjectPolicy<0>, BoxPolicy<1> >
 {
-    const JSJitPropertyOp func_;
+    const JSJitSetterOp func_;
 
-    MSetDOMProperty(const JSJitPropertyOp func, MDefinition *obj, MDefinition *val)
+    MSetDOMProperty(const JSJitSetterOp func, MDefinition *obj, MDefinition *val)
       : func_(func)
     {
         setOperand(0, obj);
@@ -6598,12 +6598,12 @@ class MSetDOMProperty
   public:
     INSTRUCTION_HEADER(SetDOMProperty)
 
-    static MSetDOMProperty *New(const JSJitPropertyOp func, MDefinition *obj, MDefinition *val)
+    static MSetDOMProperty *New(const JSJitSetterOp func, MDefinition *obj, MDefinition *val)
     {
         return new MSetDOMProperty(func, obj, val);
     }
 
-    const JSJitPropertyOp fun() {
+    const JSJitSetterOp fun() {
         return func_;
     }
 
@@ -6631,6 +6631,7 @@ class MGetDOMProperty
       : info_(jitinfo)
     {
         JS_ASSERT(jitinfo);
+        JS_ASSERT(jitinfo->type == JSJitInfo::Getter);
 
         setOperand(0, obj);
 
@@ -6657,8 +6658,8 @@ class MGetDOMProperty
         return new MGetDOMProperty(info, obj, guard);
     }
 
-    const JSJitPropertyOp fun() {
+    const JSJitGetterOp fun() {
-        return info_->op;
+        return info_->getter;
     }
     bool isInfallible() const {
         return info_->isInfallible;

js/src/jsfriendapi.h

@@ -14,6 +14,8 @@
 #include "jspubtd.h"
 #include "jsprvtd.h"
 
+#include "js/CallArgs.h"
+
 /*
  * This macro checks if the stack pointer has exceeded a given limit. If
  * |tolerance| is non-zero, it returns true only if the stack pointer has
@@ -1432,14 +1434,86 @@ JS_GetDataViewByteLength(JSObject *obj);
 JS_FRIEND_API(void *)
 JS_GetDataViewData(JSObject *obj);
 
+/*
+ * A class, expected to be passed by value, which represents the CallArgs for a
+ * JSJitGetterOp.
+ */
+class JSJitGetterCallArgs : protected JS::MutableHandleValue
+{
+  public:
+    explicit JSJitGetterCallArgs(const JS::CallArgs& args)
+      : JS::MutableHandleValue(args.rval())
+    {}
+
+    JS::MutableHandleValue rval() {
+        return *this;
+    }
+};
+
+/*
+ * A class, expected to be passed by value, which represents the CallArgs for a
+ * JSJitSetterOp.
+ */
+class JSJitSetterCallArgs : protected JS::MutableHandleValue
+{
+  public:
+    explicit JSJitSetterCallArgs(const JS::CallArgs& args)
+      : JS::MutableHandleValue(args.handleAt(0))
+    {}
+
+    JS::MutableHandleValue handleAt(unsigned i) {
+        MOZ_ASSERT(i == 0);
+        return *this;
+    }
+
+    unsigned length() const { return 1; }
+
+    // Add get() or maybe hasDefined() as needed
+};
+
+/*
+ * A class, expected to be passed by reference, which represents the CallArgs
+ * for a JSJitMethodOp.
+ */
+class JSJitMethodCallArgs : protected JS::detail::CallArgsBase<JS::detail::NoUsedRval>
+{
+  private:
+    typedef JS::detail::CallArgsBase<JS::detail::NoUsedRval> Base;
+
+  public:
+    explicit JSJitMethodCallArgs(const JS::CallArgs& args) {
+        argv_ = args.array();
+        argc_ = args.length();
+    }
+
+    JS::MutableHandleValue rval() const {
+        return Base::rval();
+    }
+
+    unsigned length() const { return Base::length(); }
+
+    JS::MutableHandleValue handleAt(unsigned i) const {
+        return Base::handleAt(i);
+    }
+
+    bool hasDefined(unsigned i) const {
+        return Base::hasDefined(i);
+    }
+
+    // Add get() as needed
+};
+
 /*
  * This struct contains metadata passed from the DOM to the JS Engine for JIT
  * optimizations on DOM property accessors. Eventually, this should be made
  * available to general JSAPI users, but we are not currently ready to do so.
  */
 typedef bool
-(* JSJitPropertyOp)(JSContext *cx, JSHandleObject thisObj,
+(* JSJitGetterOp)(JSContext *cx, JSHandleObject thisObj,
-                    void *specializedThis, JS::Value *vp);
+                  void *specializedThis, JS::Value *vp);
+typedef bool
+(* JSJitSetterOp)(JSContext *cx, JSHandleObject thisObj,
+                  void *specializedThis, JS::Value *vp);
 typedef bool
 (* JSJitMethodOp)(JSContext *cx, JSHandleObject thisObj,
                   void *specializedThis, unsigned argc, JS::Value *vp);
@@ -1451,7 +1525,11 @@ struct JSJitInfo {
         Method
     };
 
-    JSJitPropertyOp op;
+    union {
+        JSJitGetterOp getter;
+        JSJitSetterOp setter;
+        JSJitMethodOp method;
+    };
     uint32_t protoID;
     uint32_t depth;
     OpType type;

js/src/shell/js.cpp

@@ -4604,7 +4604,7 @@ dom_doFoo(JSContext* cx, JSHandleObject obj, void *self, unsigned argc, JS::Valu
 }
 
 const JSJitInfo dom_x_getterinfo = {
-    (JSJitPropertyOp)dom_get_x,
+    { (JSJitGetterOp)dom_get_x },
     0,        /* protoID */
     0,        /* depth */
     JSJitInfo::Getter,
@@ -4613,7 +4613,7 @@ const JSJitInfo dom_x_getterinfo = {
 };
 
 const JSJitInfo dom_x_setterinfo = {
-    (JSJitPropertyOp)dom_set_x,
+    { (JSJitGetterOp)dom_set_x },
     0,        /* protoID */
     0,        /* depth */
     JSJitInfo::Setter,
@@ -4622,7 +4622,7 @@ const JSJitInfo dom_x_setterinfo = {
 };
 
 const JSJitInfo doFoo_methodinfo = {
-    (JSJitPropertyOp)dom_doFoo,
+    { (JSJitGetterOp)dom_doFoo },
     0,        /* protoID */
     0,        /* depth */
     JSJitInfo::Method,
@@ -4684,7 +4684,7 @@ dom_genericGetter(JSContext *cx, unsigned argc, JS::Value *vp)
 
     const JSJitInfo *info = FUNCTION_VALUE_TO_JITINFO(JS_CALLEE(cx, vp));
     MOZ_ASSERT(info->type == JSJitInfo::Getter);
-    JSJitPropertyOp getter = info->op;
+    JSJitGetterOp getter = info->getter;
     return getter(cx, obj, val.toPrivate(), vp);
 }
 
@@ -4707,7 +4707,7 @@ dom_genericSetter(JSContext* cx, unsigned argc, JS::Value* vp)
 
     const JSJitInfo *info = FUNCTION_VALUE_TO_JITINFO(JS_CALLEE(cx, vp));
     MOZ_ASSERT(info->type == JSJitInfo::Setter);
-    JSJitPropertyOp setter = info->op;
+    JSJitSetterOp setter = info->setter;
     if (!setter(cx, obj, val.toPrivate(), argv))
         return false;
     JS_SET_RVAL(cx, vp, UndefinedValue());
@@ -4730,7 +4730,7 @@ dom_genericMethod(JSContext* cx, unsigned argc, JS::Value *vp)
 
     const JSJitInfo *info = FUNCTION_VALUE_TO_JITINFO(JS_CALLEE(cx, vp));
     MOZ_ASSERT(info->type == JSJitInfo::Method);
-    JSJitMethodOp method = (JSJitMethodOp)info->op;
+    JSJitMethodOp method = info->method;
     return method(cx, obj, val.toPrivate(), argc, vp);
 }