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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+/* Call and construct API. */
+
+#ifndef js_CallAndConstruct_h
+#define js_CallAndConstruct_h
+
+#include "mozilla/Assertions.h"  // MOZ_ASSERT
+
+#include "jstypes.h"  // JS_PUBLIC_API
+
+#include "js/RootingAPI.h"  // JS::Handle, JS::MutableHandle
+#include "js/Value.h"       // JS::Value, JS::ObjectValue
+#include "js/ValueArray.h"  // JS::HandleValueArray
+
+struct JSContext;
+class JSObject;
+class JSFunction;
+
+/*
+ * API for determining callability and constructability. [[Call]] and
+ * [[Construct]] are internal methods that aren't present on all objects, so it
+ * is useful to ask if they are there or not. The standard itself asks these
+ * questions routinely.
+ */
+namespace JS {
+
+/**
+ * Return true if the given object is callable. In ES6 terms, an object is
+ * callable if it has a [[Call]] internal method.
+ *
+ * Implements: ES6 7.2.3 IsCallable(argument).
+ *
+ * Functions are callable. A scripted proxy or wrapper is callable if its
+ * target is callable. Most other objects aren't callable.
+ */
+extern JS_PUBLIC_API bool IsCallable(JSObject* obj);
+
+/**
+ * Return true if the given object is a constructor. In ES6 terms, an object is
+ * a constructor if it has a [[Construct]] internal method. The expression
+ * `new obj()` throws a TypeError if obj is not a constructor.
+ *
+ * Implements: ES6 7.2.4 IsConstructor(argument).
+ *
+ * JS functions and classes are constructors. Arrow functions and most builtin
+ * functions are not. A scripted proxy or wrapper is a constructor if its
+ * target is a constructor.
+ */
+extern JS_PUBLIC_API bool IsConstructor(JSObject* obj);
+
+} /* namespace JS */
+
+/**
+ * Call a function, passing a this-value and arguments. This is the C++
+ * equivalent of `rval = Reflect.apply(fun, obj, args)`.
+ *
+ * Implements: ES6 7.3.12 Call(F, V, [argumentsList]).
+ * Use this function to invoke the [[Call]] internal method.
+ */
+extern JS_PUBLIC_API bool JS_CallFunctionValue(
+    JSContext* cx, JS::Handle<JSObject*> obj, JS::Handle<JS::Value> fval,
+    const JS::HandleValueArray& args, JS::MutableHandle<JS::Value> rval);
+
+extern JS_PUBLIC_API bool JS_CallFunction(JSContext* cx,
+                                          JS::Handle<JSObject*> obj,
+                                          JS::Handle<JSFunction*> fun,
+                                          const JS::HandleValueArray& args,
+                                          JS::MutableHandle<JS::Value> rval);
+
+/**
+ * Perform the method call `rval = obj[name](args)`.
+ */
+extern JS_PUBLIC_API bool JS_CallFunctionName(
+    JSContext* cx, JS::Handle<JSObject*> obj, const char* name,
+    const JS::HandleValueArray& args, JS::MutableHandle<JS::Value> rval);
+
+namespace JS {
+
+static inline bool Call(JSContext* cx, Handle<JSObject*> thisObj,
+                        Handle<JSFunction*> fun, const HandleValueArray& args,
+                        MutableHandle<Value> rval) {
+  return !!JS_CallFunction(cx, thisObj, fun, args, rval);
+}
+
+static inline bool Call(JSContext* cx, Handle<JSObject*> thisObj,
+                        Handle<Value> fun, const HandleValueArray& args,
+                        MutableHandle<Value> rval) {
+  return !!JS_CallFunctionValue(cx, thisObj, fun, args, rval);
+}
+
+static inline bool Call(JSContext* cx, Handle<JSObject*> thisObj,
+                        const char* name, const HandleValueArray& args,
+                        MutableHandle<Value> rval) {
+  return !!JS_CallFunctionName(cx, thisObj, name, args, rval);
+}
+
+extern JS_PUBLIC_API bool Call(JSContext* cx, Handle<Value> thisv,
+                               Handle<Value> fun, const HandleValueArray& args,
+                               MutableHandle<Value> rval);
+
+static inline bool Call(JSContext* cx, Handle<Value> thisv,
+                        Handle<JSObject*> funObj, const HandleValueArray& args,
+                        MutableHandle<Value> rval) {
+  MOZ_ASSERT(funObj);
+  Rooted<Value> fun(cx, ObjectValue(*funObj));
+  return Call(cx, thisv, fun, args, rval);
+}
+
+/**
+ * Invoke a constructor. This is the C++ equivalent of
+ * `rval = Reflect.construct(fun, args, newTarget)`.
+ *
+ * Construct() takes a `newTarget` argument that most callers don't need.
+ * Consider using the four-argument Construct signature instead. (But if you're
+ * implementing a subclass or a proxy handler's construct() method, this is the
+ * right function to call.)
+ *
+ * Implements: ES6 7.3.13 Construct(F, [argumentsList], [newTarget]).
+ * Use this function to invoke the [[Construct]] internal method.
+ */
+extern JS_PUBLIC_API bool Construct(JSContext* cx, Handle<Value> fun,
+                                    Handle<JSObject*> newTarget,
+                                    const HandleValueArray& args,
+                                    MutableHandle<JSObject*> objp);
+
+/**
+ * Invoke a constructor. This is the C++ equivalent of
+ * `rval = new fun(...args)`.
+ *
+ * Implements: ES6 7.3.13 Construct(F, [argumentsList], [newTarget]), when
+ * newTarget is omitted.
+ */
+extern JS_PUBLIC_API bool Construct(JSContext* cx, Handle<Value> fun,
+                                    const HandleValueArray& args,
+                                    MutableHandle<JSObject*> objp);
+
+} /* namespace JS */
+
+#endif /* js_CallAndConstruct_h */