Merge branch 'master' of github.com:6to5/6to5

src/babel/api/register/node.js

@@ -10,6 +10,7 @@ var util             = require("../../util");
 var fs               = require("fs");
 
 sourceMapSupport.install({
+  handleUncaughtExceptions: false,
   retrieveSourceMap(source) {
     var map = maps && maps[source];
     if (map) {

src/babel/transformation/transformers/es6/parameters.rest.js

@@ -3,6 +3,49 @@ var t    = require("../../../types");
 
 exports.check = t.isRestElement;
 
+var memberExpressionVisitor = {
+  enter(node, parent, scope, state) {
+    if (t.isScope(node, parent) && !scope.bindingIdentifierEquals(state.name, state.outerDeclar)) {
+      return this.skip();
+    }
+
+    if (t.isFunctionDeclaration(node) || t.isFunctionExpression(node)) {
+      state.isOptimizable = false;
+      return this.stop();
+    }
+
+    if (!t.isReferencedIdentifier(node, parent, { name: state.name })) return;
+
+    if (t.isMemberExpression(parent)) {
+      var prop = parent.property;
+      if (typeof prop.value === "number" ||
+          t.isUnaryExpression(prop) ||
+          t.isBinaryExpression(prop)) {
+        state.candidates.push({ node, parent });
+        return;
+      }
+    }
+
+    state.isOptimizable = false;
+    this.stop();
+  }
+};
+
+function optimizeMemberExpression(node, parent, offset) {
+  var newExpr;
+  var prop = parent.property;
+
+  if (t.isLiteral(prop)) {
+    node.name = "arguments";
+    prop.value += offset;
+    prop.raw = String(prop.value);
+  } else {
+    node.name = "arguments";
+    newExpr = t.binaryExpression("+", prop, t.literal(offset));
+    parent.property = newExpr;
+  }
+}
+
 var hasRest = function (node) {
   return t.isRestElement(node.params[node.params.length - 1]);
 };
@@ -17,6 +60,35 @@ exports.Function = function (node, parent, scope) {
   // otherwise `arguments` will be remapped in arrow functions
   argsId._ignoreAliasFunctions = true;
 
+  // support patterns
+  if (t.isPattern(rest)) {
+    var pattern = rest;
+    rest = scope.generateUidIdentifier("ref");
+    var declar = t.variableDeclaration("var", pattern.elements.map(function (elem, index) {
+      var accessExpr = t.memberExpression(rest, t.literal(index), true);
+      return t.variableDeclarator(elem, accessExpr);
+    }));
+    node.body.body.unshift(declar);
+  }
+
+  // check if rest is used only in member expressions
+  var restOuterDeclar = scope.getBindingIdentifier(rest.name);
+  var state = {
+    name: rest.name,
+    outerDeclar: restOuterDeclar,
+    isOptimizable: true,
+    candidates: []
+  };
+  scope.traverse(node, memberExpressionVisitor, state);
+
+  if (state.isOptimizable) {
+    for (let i = 0, count = state.candidates.length; i < count; ++i) {
+      let candidate = state.candidates[i];
+      optimizeMemberExpression(candidate.node, candidate.parent, node.params.length, state.strictMode);
+    }
+    return;
+  }
+
   var start = t.literal(node.params.length);
   var key = scope.generateUidIdentifier("key");
   var len = scope.generateUidIdentifier("len");
@@ -42,22 +114,6 @@ exports.Function = function (node, parent, scope) {
     );
   }
 
-  // support patterns
-  if (t.isPattern(rest)) {
-    var pattern = rest;
-    rest = scope.generateUidIdentifier("ref");
-
-    // let the destructuring transformer handle this
-    var restDeclar = t.variableDeclaration("var", [
-      t.variableDeclarator(pattern, rest)
-    ]);
-
-    // retain evaluation position
-    restDeclar._blockHoist = node.params.length + 1;
-
-    node.body.body.unshift(restDeclar);
-  }
-
   scope.assignTypeGeneric(rest.name, "Array");
 
   var loop = util.template("rest", {

test/fixtures/transformation/es6-parameters.rest/arrow-functions/actual.js

@@ -1,3 +1,4 @@
 var concat = (...arrs) => {
-
+    var x = arrs[0];
+    var y = arrs[1];
 };

test/fixtures/transformation/es6-parameters.rest/arrow-functions/expected.js

@@ -1,7 +1,8 @@
 "use strict";
 
+var _arguments = arguments;
 var concat = function () {
-  for (var _len = arguments.length, arrs = Array(_len), _key = 0; _key < _len; _key++) {
-    arrs[_key] = arguments[_key];
-  }
+    var x = _arguments[0];
+    var y = _arguments[1];
 };
+

test/fixtures/transformation/es6-parameters.rest/deopt/actual.js

@@ -0,0 +1,24 @@
+var x = function (foo, ...bar) {
+  console.log(bar);
+};
+
+var y = function (foo, ...bar) {
+  var x = function z(bar) {
+    bar[1] = 5;
+  };
+};
+
+var z = function (foo, ...bar) {
+    var x = function () {
+        bar[1] = 5;
+    };
+};
+
+var a = function (foo, ...bar) {
+    return bar.join(',');
+};
+
+var b = function (foo, ...bar) {
+    var join = "join";
+    return bar[join];
+};

test/fixtures/transformation/es6-parameters.rest/deopt/expected.js

@@ -0,0 +1,43 @@
+"use strict";
+
+var x = function x(foo) {
+    for (var _len = arguments.length, bar = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
+        bar[_key - 1] = arguments[_key];
+    }
+
+    console.log(bar);
+};
+
+var y = function y(foo) {
+    var x = function z(bar) {
+        bar[1] = 5;
+    };
+};
+
+var z = function z(foo) {
+    for (var _len = arguments.length, bar = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
+        bar[_key - 1] = arguments[_key];
+    }
+
+    var x = function x() {
+        bar[1] = 5;
+    };
+};
+
+var a = function a(foo) {
+    for (var _len = arguments.length, bar = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
+        bar[_key - 1] = arguments[_key];
+    }
+
+    return bar.join(",");
+};
+
+var b = function b(foo) {
+    for (var _len = arguments.length, bar = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
+        bar[_key - 1] = arguments[_key];
+    }
+
+    var join = "join";
+    return bar[join];
+};
+

test/fixtures/transformation/es6-parameters.rest/multiple/actual.js

@@ -1,7 +1,11 @@
 var t = function (f, ...items) {
-
+    var x = f;
+    x = items[0];
+    x = items[1];
 };
 
 function t(f, ...items) {
-
+    var x = f;
+    x = items[0];
+    x = items[1];
 }

test/fixtures/transformation/es6-parameters.rest/multiple/expected.js

@@ -1,13 +1,14 @@
 "use strict";
 
 var t = function t(f) {
-  for (var _len = arguments.length, items = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
-    items[_key - 1] = arguments[_key];
-  }
+    var x = f;
+    x = arguments[1];
+    x = arguments[2];
 };
 
 function t(f) {
-  for (var _len = arguments.length, items = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
-    items[_key - 1] = arguments[_key];
-  }
+    var x = f;
+    x = arguments[1];
+    x = arguments[2];
 }
+

test/fixtures/transformation/es6-parameters.rest/pattern/actual.js

@@ -1,3 +1,2 @@
 var foo = function (...[a, b]) {
-
 };

test/fixtures/transformation/es6-parameters.rest/pattern/expected.js

@@ -1,10 +1,7 @@
 "use strict";
 
 var foo = function foo() {
-  for (var _len = arguments.length, _ref = Array(_len), _key = 0; _key < _len; _key++) {
-    _ref[_key] = arguments[_key];
-  }
-
-  var a = _ref[0];
-  var b = _ref[1];
+  var a = arguments[0],
+      b = arguments[1];
 };
+

test/fixtures/transformation/es6-parameters.rest/single/actual.js

@@ -1,7 +1,9 @@
 var t = function (...items) {
-
+    var x = items[0];
+    var y = items[1];
 }
 
 function t(...items) {
-
+    var x = items[0];
+    var y = items[1];
 }

test/fixtures/transformation/es6-parameters.rest/single/expected.js

@@ -1,13 +1,12 @@
 "use strict";
 
 var t = function t() {
-  for (var _len = arguments.length, items = Array(_len), _key = 0; _key < _len; _key++) {
-    items[_key] = arguments[_key];
-  }
+    var x = arguments[0];
+    var y = arguments[1];
 };
 
 function t() {
-  for (var _len = arguments.length, items = Array(_len), _key = 0; _key < _len; _key++) {
-    items[_key] = arguments[_key];
-  }
+    var x = arguments[0];
+    var y = arguments[1];
 }
+