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-rw-r--r--js/src/builtin/Function.js476
1 files changed, 476 insertions, 0 deletions
diff --git a/js/src/builtin/Function.js b/js/src/builtin/Function.js
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+/* 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/. */
+
+// ES7 draft (January 21, 2016) 19.2.3.2 Function.prototype.bind
+function FunctionBind(thisArg, ...boundArgs) {
+ // Step 1.
+ var target = this;
+ // Step 2.
+ if (!IsCallable(target)) {
+ ThrowTypeError(JSMSG_INCOMPATIBLE_PROTO, "Function", "bind", target);
+ }
+
+ // Step 3 (implicit).
+ // Step 4.
+ var F;
+ var argCount = boundArgs.length;
+ switch (argCount) {
+ case 0:
+ F = bind_bindFunction0(target, thisArg, boundArgs);
+ break;
+ case 1:
+ F = bind_bindFunction1(target, thisArg, boundArgs);
+ break;
+ case 2:
+ F = bind_bindFunction2(target, thisArg, boundArgs);
+ break;
+ default:
+ F = bind_bindFunctionN(target, thisArg, boundArgs);
+ }
+
+ // Steps 5-11.
+ FinishBoundFunctionInit(F, target, argCount);
+
+ // Ensure that the apply intrinsic has been cloned so it can be baked into
+ // JIT code.
+ void std_Function_apply;
+
+ // Step 12.
+ return F;
+}
+/**
+ * bind_bindFunction{0,1,2} are special cases of the generic bind_bindFunctionN
+ * below. They avoid the need to merge the lists of bound arguments and call
+ * arguments to the bound function into a new list which is then used in a
+ * destructuring call of the bound function.
+ *
+ * All three of these functions again have special-cases for call argument
+ * counts between 0 and 5. For calls with 6+ arguments, all - bound and call -
+ * arguments are copied into an array before invoking the generic call and
+ * construct helper functions. This avoids having to use rest parameters and
+ * destructuring in the fast path.
+ *
+ * Directly embedding the for-loop to combine bound and call arguments may
+ * inhibit inlining of the bound function, so we use a separate combiner
+ * function to perform this task. This combiner function is created lazily to
+ * ensure we only pay its construction cost when needed.
+ *
+ * All bind_bindFunction{X} functions have the same signature to enable simple
+ * reading out of closed-over state by debugging functions.
+ *
+ * Note: We use the '$' prefix on the function to force it to be an extended
+ * function so that `finishBoundFunctionInit` can track length.
+ */
+function bind_bindFunction0(fun, thisArg, boundArgs) {
+ return function $bound() {
+ // Ensure we allocate a call-object slot for |boundArgs|, so the
+ // debugger can access this value.
+ if (false) {
+ void boundArgs;
+ }
+
+ var newTarget;
+ if (IsConstructing()) {
+ newTarget = new.target;
+ if (newTarget === $bound) {
+ newTarget = fun;
+ }
+ switch (arguments.length) {
+ case 0:
+ return constructContentFunction(fun, newTarget);
+ case 1:
+ return constructContentFunction(fun, newTarget, SPREAD(arguments, 1));
+ case 2:
+ return constructContentFunction(fun, newTarget, SPREAD(arguments, 2));
+ case 3:
+ return constructContentFunction(fun, newTarget, SPREAD(arguments, 3));
+ case 4:
+ return constructContentFunction(fun, newTarget, SPREAD(arguments, 4));
+ case 5:
+ return constructContentFunction(fun, newTarget, SPREAD(arguments, 5));
+ default:
+ var args = FUN_APPLY(bind_mapArguments, null, arguments);
+ return bind_constructFunctionN(fun, newTarget, args);
+ }
+ } else {
+ switch (arguments.length) {
+ case 0:
+ return callContentFunction(fun, thisArg);
+ case 1:
+ return callContentFunction(fun, thisArg, SPREAD(arguments, 1));
+ case 2:
+ return callContentFunction(fun, thisArg, SPREAD(arguments, 2));
+ case 3:
+ return callContentFunction(fun, thisArg, SPREAD(arguments, 3));
+ case 4:
+ return callContentFunction(fun, thisArg, SPREAD(arguments, 4));
+ case 5:
+ return callContentFunction(fun, thisArg, SPREAD(arguments, 5));
+ default:
+ return FUN_APPLY(fun, thisArg, arguments);
+ }
+ }
+ };
+}
+
+function bind_bindFunction1(fun, thisArg, boundArgs) {
+ var bound1 = boundArgs[0];
+ var combiner = null;
+ return function $bound() {
+ // Ensure we allocate a call-object slot for |boundArgs|, so the
+ // debugger can access this value.
+ if (false) {
+ void boundArgs;
+ }
+
+ var newTarget;
+ if (IsConstructing()) {
+ newTarget = new.target;
+ if (newTarget === $bound) {
+ newTarget = fun;
+ }
+ switch (arguments.length) {
+ case 0:
+ return constructContentFunction(fun, newTarget, bound1);
+ case 1:
+ return constructContentFunction(
+ fun,
+ newTarget,
+ bound1,
+ SPREAD(arguments, 1)
+ );
+ case 2:
+ return constructContentFunction(
+ fun,
+ newTarget,
+ bound1,
+ SPREAD(arguments, 2)
+ );
+ case 3:
+ return constructContentFunction(
+ fun,
+ newTarget,
+ bound1,
+ SPREAD(arguments, 3)
+ );
+ case 4:
+ return constructContentFunction(
+ fun,
+ newTarget,
+ bound1,
+ SPREAD(arguments, 4)
+ );
+ case 5:
+ return constructContentFunction(
+ fun,
+ newTarget,
+ bound1,
+ SPREAD(arguments, 5)
+ );
+ }
+ } else {
+ switch (arguments.length) {
+ case 0:
+ return callContentFunction(fun, thisArg, bound1);
+ case 1:
+ return callContentFunction(
+ fun,
+ thisArg,
+ bound1,
+ SPREAD(arguments, 1)
+ );
+ case 2:
+ return callContentFunction(
+ fun,
+ thisArg,
+ bound1,
+ SPREAD(arguments, 2)
+ );
+ case 3:
+ return callContentFunction(
+ fun,
+ thisArg,
+ bound1,
+ SPREAD(arguments, 3)
+ );
+ case 4:
+ return callContentFunction(
+ fun,
+ thisArg,
+ bound1,
+ SPREAD(arguments, 4)
+ );
+ case 5:
+ return callContentFunction(
+ fun,
+ thisArg,
+ bound1,
+ SPREAD(arguments, 5)
+ );
+ }
+ }
+
+ if (combiner === null) {
+ combiner = function() {
+ var callArgsCount = arguments.length;
+ var args = std_Array(1 + callArgsCount);
+ DefineDataProperty(args, 0, bound1);
+ for (var i = 0; i < callArgsCount; i++) {
+ DefineDataProperty(args, i + 1, arguments[i]);
+ }
+ return args;
+ };
+ }
+
+ var args = FUN_APPLY(combiner, null, arguments);
+ if (newTarget === undefined) {
+ return bind_applyFunctionN(fun, thisArg, args);
+ }
+ return bind_constructFunctionN(fun, newTarget, args);
+ };
+}
+
+function bind_bindFunction2(fun, thisArg, boundArgs) {
+ var bound1 = boundArgs[0];
+ var bound2 = boundArgs[1];
+ var combiner = null;
+ return function $bound() {
+ // Ensure we allocate a call-object slot for |boundArgs|, so the
+ // debugger can access this value.
+ if (false) {
+ void boundArgs;
+ }
+
+ var newTarget;
+ if (IsConstructing()) {
+ newTarget = new.target;
+ if (newTarget === $bound) {
+ newTarget = fun;
+ }
+ switch (arguments.length) {
+ case 0:
+ return constructContentFunction(fun, newTarget, bound1, bound2);
+ case 1:
+ return constructContentFunction(
+ fun,
+ newTarget,
+ bound1,
+ bound2,
+ SPREAD(arguments, 1)
+ );
+ case 2:
+ return constructContentFunction(
+ fun,
+ newTarget,
+ bound1,
+ bound2,
+ SPREAD(arguments, 2)
+ );
+ case 3:
+ return constructContentFunction(
+ fun,
+ newTarget,
+ bound1,
+ bound2,
+ SPREAD(arguments, 3)
+ );
+ case 4:
+ return constructContentFunction(
+ fun,
+ newTarget,
+ bound1,
+ bound2,
+ SPREAD(arguments, 4)
+ );
+ case 5:
+ return constructContentFunction(
+ fun,
+ newTarget,
+ bound1,
+ bound2,
+ SPREAD(arguments, 5)
+ );
+ }
+ } else {
+ switch (arguments.length) {
+ case 0:
+ return callContentFunction(fun, thisArg, bound1, bound2);
+ case 1:
+ return callContentFunction(
+ fun,
+ thisArg,
+ bound1,
+ bound2,
+ SPREAD(arguments, 1)
+ );
+ case 2:
+ return callContentFunction(
+ fun,
+ thisArg,
+ bound1,
+ bound2,
+ SPREAD(arguments, 2)
+ );
+ case 3:
+ return callContentFunction(
+ fun,
+ thisArg,
+ bound1,
+ bound2,
+ SPREAD(arguments, 3)
+ );
+ case 4:
+ return callContentFunction(
+ fun,
+ thisArg,
+ bound1,
+ bound2,
+ SPREAD(arguments, 4)
+ );
+ case 5:
+ return callContentFunction(
+ fun,
+ thisArg,
+ bound1,
+ bound2,
+ SPREAD(arguments, 5)
+ );
+ }
+ }
+
+ if (combiner === null) {
+ combiner = function() {
+ var callArgsCount = arguments.length;
+ var args = std_Array(2 + callArgsCount);
+ DefineDataProperty(args, 0, bound1);
+ DefineDataProperty(args, 1, bound2);
+ for (var i = 0; i < callArgsCount; i++) {
+ DefineDataProperty(args, i + 2, arguments[i]);
+ }
+ return args;
+ };
+ }
+
+ var args = FUN_APPLY(combiner, null, arguments);
+ if (newTarget === undefined) {
+ return bind_applyFunctionN(fun, thisArg, args);
+ }
+ return bind_constructFunctionN(fun, newTarget, args);
+ };
+}
+
+function bind_bindFunctionN(fun, thisArg, boundArgs) {
+ assert(
+ boundArgs.length > 2,
+ "Fast paths should be used for few-bound-args cases."
+ );
+ var combiner = null;
+ return function $bound() {
+ var newTarget;
+ if (IsConstructing()) {
+ newTarget = new.target;
+ if (newTarget === $bound) {
+ newTarget = fun;
+ }
+ }
+ if (arguments.length === 0) {
+ if (newTarget !== undefined) {
+ return bind_constructFunctionN(fun, newTarget, boundArgs);
+ }
+ return bind_applyFunctionN(fun, thisArg, boundArgs);
+ }
+
+ if (combiner === null) {
+ combiner = function() {
+ var boundArgsCount = boundArgs.length;
+ var callArgsCount = arguments.length;
+ var args = std_Array(boundArgsCount + callArgsCount);
+ for (var i = 0; i < boundArgsCount; i++) {
+ DefineDataProperty(args, i, boundArgs[i]);
+ }
+ for (var i = 0; i < callArgsCount; i++) {
+ DefineDataProperty(args, i + boundArgsCount, arguments[i]);
+ }
+ return args;
+ };
+ }
+
+ var args = FUN_APPLY(combiner, null, arguments);
+ if (newTarget !== undefined) {
+ return bind_constructFunctionN(fun, newTarget, args);
+ }
+ return bind_applyFunctionN(fun, thisArg, args);
+ };
+}
+
+function bind_mapArguments() {
+ var len = arguments.length;
+ var args = std_Array(len);
+ for (var i = 0; i < len; i++) {
+ DefineDataProperty(args, i, arguments[i]);
+ }
+ return args;
+}
+
+function bind_applyFunctionN(fun, thisArg, args) {
+ switch (args.length) {
+ case 0:
+ return callContentFunction(fun, thisArg);
+ case 1:
+ return callContentFunction(fun, thisArg, SPREAD(args, 1));
+ case 2:
+ return callContentFunction(fun, thisArg, SPREAD(args, 2));
+ case 3:
+ return callContentFunction(fun, thisArg, SPREAD(args, 3));
+ case 4:
+ return callContentFunction(fun, thisArg, SPREAD(args, 4));
+ case 5:
+ return callContentFunction(fun, thisArg, SPREAD(args, 5));
+ case 6:
+ return callContentFunction(fun, thisArg, SPREAD(args, 6));
+ case 7:
+ return callContentFunction(fun, thisArg, SPREAD(args, 7));
+ case 8:
+ return callContentFunction(fun, thisArg, SPREAD(args, 8));
+ case 9:
+ return callContentFunction(fun, thisArg, SPREAD(args, 9));
+ default:
+ return FUN_APPLY(fun, thisArg, args);
+ }
+}
+
+function bind_constructFunctionN(fun, newTarget, args) {
+ switch (args.length) {
+ case 1:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 1));
+ case 2:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 2));
+ case 3:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 3));
+ case 4:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 4));
+ case 5:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 5));
+ case 6:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 6));
+ case 7:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 7));
+ case 8:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 8));
+ case 9:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 9));
+ case 10:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 10));
+ case 11:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 11));
+ case 12:
+ return constructContentFunction(fun, newTarget, SPREAD(args, 12));
+ default:
+ assert(
+ args.length !== 0,
+ "bound function construction without args should be handled by caller"
+ );
+ return ConstructFunction(fun, newTarget, args);
+ }
+}
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