From 77dad0d333fb0de52de47d6ae91633800b92c78c Mon Sep 17 00:00:00 2001 From: Ben Newman Date: Mon, 21 Nov 2016 16:15:27 -0500 Subject: [PATCH] Use regenerator-transform to implement babel-plugin-transform-regenerator. Though I believe this is safe to merge, you may want to wait to merge it until https://github.com/facebook/regenerator/pull/259 is merged. That pull request also provides more explanation of why I think moving the implementation of Regenerator back to its original repository is a good idea. I'm happy to compromise on anything necessary to make this happen. Note that the regenerator-transform version is pegged to an exact version (0.9.5). Past experience has taught me that releasing new versions of Regenerator is almost impossible if client projects are allowed to pull in new patch versions automatically. I will happily submit a pull request whenever a new version is released. --- .../package.json | 4 +- .../src/emit.js | 1184 ----------------- .../src/hoist.js | 150 --- .../src/index.js | 4 +- .../src/leap.js | 174 --- .../src/meta.js | 103 -- .../src/util.js | 23 - .../src/visit.js | 269 ---- 8 files changed, 2 insertions(+), 1909 deletions(-) delete mode 100644 packages/babel-plugin-transform-regenerator/src/emit.js delete mode 100644 packages/babel-plugin-transform-regenerator/src/hoist.js delete mode 100644 packages/babel-plugin-transform-regenerator/src/leap.js delete mode 100644 packages/babel-plugin-transform-regenerator/src/meta.js delete mode 100644 packages/babel-plugin-transform-regenerator/src/util.js delete mode 100644 packages/babel-plugin-transform-regenerator/src/visit.js diff --git a/packages/babel-plugin-transform-regenerator/package.json b/packages/babel-plugin-transform-regenerator/package.json index 491b227a0fd6..45de7ed4cbbd 100644 --- a/packages/babel-plugin-transform-regenerator/package.json +++ b/packages/babel-plugin-transform-regenerator/package.json @@ -7,9 +7,7 @@ "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-regenerator", "main": "lib/index.js", "dependencies": { - "babel-types": "^6.16.0", - "babel-runtime": "^6.9.0", - "private": "~0.1.5" + "regenerator-transform": "0.9.5" }, "license": "BSD", "devDependencies": { diff --git a/packages/babel-plugin-transform-regenerator/src/emit.js b/packages/babel-plugin-transform-regenerator/src/emit.js deleted file mode 100644 index b3378867b3b4..000000000000 --- a/packages/babel-plugin-transform-regenerator/src/emit.js +++ /dev/null @@ -1,1184 +0,0 @@ -/** - * Copyright (c) 2014, Facebook, Inc. - * All rights reserved. - * - * This source code is licensed under the BSD-style license found in the - * https://raw.github.com/facebook/regenerator/master/LICENSE file. An - * additional grant of patent rights can be found in the PATENTS file in - * the same directory. - */ - -import assert from "assert"; -import * as t from "babel-types"; -import * as leap from "./leap"; -import * as meta from "./meta"; -import * as util from "./util"; - -let hasOwn = Object.prototype.hasOwnProperty; - -function Emitter(contextId) { - assert.ok(this instanceof Emitter); - t.assertIdentifier(contextId); - - // Used to generate unique temporary names. - this.nextTempId = 0; - - // In order to make sure the context object does not collide with - // anything in the local scope, we might have to rename it, so we - // refer to it symbolically instead of just assuming that it will be - // called "context". - this.contextId = contextId; - - // An append-only list of Statements that grows each time this.emit is - // called. - this.listing = []; - - // A sparse array whose keys correspond to locations in this.listing - // that have been marked as branch/jump targets. - this.marked = [true]; - - // The last location will be marked when this.getDispatchLoop is - // called. - this.finalLoc = loc(); - - // A list of all leap.TryEntry statements emitted. - this.tryEntries = []; - - // Each time we evaluate the body of a loop, we tell this.leapManager - // to enter a nested loop context that determines the meaning of break - // and continue statements therein. - this.leapManager = new leap.LeapManager(this); -} - -let Ep = Emitter.prototype; -exports.Emitter = Emitter; - -// Offsets into this.listing that could be used as targets for branches or -// jumps are represented as numeric Literal nodes. This representation has -// the amazingly convenient benefit of allowing the exact value of the -// location to be determined at any time, even after generating code that -// refers to the location. -function loc() { - return t.numericLiteral(-1); -} - -// Sets the exact value of the given location to the offset of the next -// Statement emitted. -Ep.mark = function(loc) { - t.assertLiteral(loc); - let index = this.listing.length; - if (loc.value === -1) { - loc.value = index; - } else { - // Locations can be marked redundantly, but their values cannot change - // once set the first time. - assert.strictEqual(loc.value, index); - } - this.marked[index] = true; - return loc; -}; - -Ep.emit = function(node) { - if (t.isExpression(node)) { - node = t.expressionStatement(node); - } - - t.assertStatement(node); - this.listing.push(node); -}; - -// Shorthand for emitting assignment statements. This will come in handy -// for assignments to temporary variables. -Ep.emitAssign = function(lhs, rhs) { - this.emit(this.assign(lhs, rhs)); - return lhs; -}; - -// Shorthand for an assignment statement. -Ep.assign = function(lhs, rhs) { - return t.expressionStatement( - t.assignmentExpression("=", lhs, rhs)); -}; - -// Convenience function for generating expressions like context.next, -// context.sent, and context.rval. -Ep.contextProperty = function(name, computed) { - return t.memberExpression( - this.contextId, - computed ? t.stringLiteral(name) : t.identifier(name), - !!computed - ); -}; - -// Shorthand for setting context.rval and jumping to `context.stop()`. -Ep.stop = function(rval) { - if (rval) { - this.setReturnValue(rval); - } - - this.jump(this.finalLoc); -}; - -Ep.setReturnValue = function(valuePath) { - t.assertExpression(valuePath.value); - - this.emitAssign( - this.contextProperty("rval"), - this.explodeExpression(valuePath) - ); -}; - -Ep.clearPendingException = function(tryLoc, assignee) { - t.assertLiteral(tryLoc); - - let catchCall = t.callExpression( - this.contextProperty("catch", true), - [tryLoc] - ); - - if (assignee) { - this.emitAssign(assignee, catchCall); - } else { - this.emit(catchCall); - } -}; - -// Emits code for an unconditional jump to the given location, even if the -// exact value of the location is not yet known. -Ep.jump = function(toLoc) { - this.emitAssign(this.contextProperty("next"), toLoc); - this.emit(t.breakStatement()); -}; - -// Conditional jump. -Ep.jumpIf = function(test, toLoc) { - t.assertExpression(test); - t.assertLiteral(toLoc); - - this.emit(t.ifStatement( - test, - t.blockStatement([ - this.assign(this.contextProperty("next"), toLoc), - t.breakStatement() - ]) - )); -}; - -// Conditional jump, with the condition negated. -Ep.jumpIfNot = function(test, toLoc) { - t.assertExpression(test); - t.assertLiteral(toLoc); - - let negatedTest; - if (t.isUnaryExpression(test) && - test.operator === "!") { - // Avoid double negation. - negatedTest = test.argument; - } else { - negatedTest = t.unaryExpression("!", test); - } - - this.emit(t.ifStatement( - negatedTest, - t.blockStatement([ - this.assign(this.contextProperty("next"), toLoc), - t.breakStatement() - ]) - )); -}; - -// Returns a unique MemberExpression that can be used to store and -// retrieve temporary values. Since the object of the member expression is -// the context object, which is presumed to coexist peacefully with all -// other local variables, and since we just increment `nextTempId` -// monotonically, uniqueness is assured. -Ep.makeTempVar = function() { - return this.contextProperty("t" + this.nextTempId++); -}; - -Ep.getContextFunction = function(id) { - return t.functionExpression( - id || null/*Anonymous*/, - [this.contextId], - t.blockStatement([this.getDispatchLoop()]), - false, // Not a generator anymore! - false // Nor an expression. - ); -}; - -// Turns this.listing into a loop of the form -// -// while (1) switch (context.next) { -// case 0: -// ... -// case n: -// return context.stop(); -// } -// -// Each marked location in this.listing will correspond to one generated -// case statement. -Ep.getDispatchLoop = function() { - let self = this; - let cases = []; - let current; - - // If we encounter a break, continue, or return statement in a switch - // case, we can skip the rest of the statements until the next case. - let alreadyEnded = false; - - self.listing.forEach(function(stmt, i) { - if (self.marked.hasOwnProperty(i)) { - cases.push(t.switchCase( - t.numericLiteral(i), - current = [])); - alreadyEnded = false; - } - - if (!alreadyEnded) { - current.push(stmt); - if (t.isCompletionStatement(stmt)) - alreadyEnded = true; - } - }); - - // Now that we know how many statements there will be in this.listing, - // we can finally resolve this.finalLoc.value. - this.finalLoc.value = this.listing.length; - - cases.push( - t.switchCase(this.finalLoc, [ - // Intentionally fall through to the "end" case... - ]), - - // So that the runtime can jump to the final location without having - // to know its offset, we provide the "end" case as a synonym. - t.switchCase(t.stringLiteral("end"), [ - // This will check/clear both context.thrown and context.rval. - t.returnStatement( - t.callExpression(this.contextProperty("stop"), []) - ) - ]) - ); - - return t.whileStatement( - t.numericLiteral(1), - t.switchStatement( - t.assignmentExpression( - "=", - this.contextProperty("prev"), - this.contextProperty("next") - ), - cases - ) - ); -}; - -Ep.getTryLocsList = function() { - if (this.tryEntries.length === 0) { - // To avoid adding a needless [] to the majority of runtime.wrap - // argument lists, force the caller to handle this case specially. - return null; - } - - let lastLocValue = 0; - - return t.arrayExpression( - this.tryEntries.map(function(tryEntry) { - let thisLocValue = tryEntry.firstLoc.value; - assert.ok(thisLocValue >= lastLocValue, "try entries out of order"); - lastLocValue = thisLocValue; - - let ce = tryEntry.catchEntry; - let fe = tryEntry.finallyEntry; - - let locs = [ - tryEntry.firstLoc, - // The null here makes a hole in the array. - ce ? ce.firstLoc : null - ]; - - if (fe) { - locs[2] = fe.firstLoc; - locs[3] = fe.afterLoc; - } - - return t.arrayExpression(locs); - }) - ); -}; - -// All side effects must be realized in order. - -// If any subexpression harbors a leap, all subexpressions must be -// neutered of side effects. - -// No destructive modification of AST nodes. - -Ep.explode = function(path, ignoreResult) { - let node = path.node; - let self = this; - - t.assertNode(node); - - if (t.isDeclaration(node)) - throw getDeclError(node); - - if (t.isStatement(node)) - return self.explodeStatement(path); - - if (t.isExpression(node)) - return self.explodeExpression(path, ignoreResult); - - switch (node.type) { - case "Program": - return path.get("body").map( - self.explodeStatement, - self - ); - - case "VariableDeclarator": - throw getDeclError(node); - - // These node types should be handled by their parent nodes - // (ObjectExpression, SwitchStatement, and TryStatement, respectively). - case "Property": - case "SwitchCase": - case "CatchClause": - throw new Error( - node.type + " nodes should be handled by their parents"); - - default: - throw new Error( - "unknown Node of type " + - JSON.stringify(node.type)); - } -}; - -function getDeclError(node) { - return new Error( - "all declarations should have been transformed into " + - "assignments before the Exploder began its work: " + - JSON.stringify(node)); -} - -Ep.explodeStatement = function(path, labelId) { - let stmt = path.node; - let self = this; - let before, after, head; - - t.assertStatement(stmt); - - if (labelId) { - t.assertIdentifier(labelId); - } else { - labelId = null; - } - - // Explode BlockStatement nodes even if they do not contain a yield, - // because we don't want or need the curly braces. - if (t.isBlockStatement(stmt)) { - path.get("body").forEach(function (path) { - self.explodeStatement(path); - }); - return; - } - - if (!meta.containsLeap(stmt)) { - // Technically we should be able to avoid emitting the statement - // altogether if !meta.hasSideEffects(stmt), but that leads to - // confusing generated code (for instance, `while (true) {}` just - // disappears) and is probably a more appropriate job for a dedicated - // dead code elimination pass. - self.emit(stmt); - return; - } - - switch (stmt.type) { - case "ExpressionStatement": - self.explodeExpression(path.get("expression"), true); - break; - - case "LabeledStatement": - after = loc(); - - // Did you know you can break from any labeled block statement or - // control structure? Well, you can! Note: when a labeled loop is - // encountered, the leap.LabeledEntry created here will immediately - // enclose a leap.LoopEntry on the leap manager's stack, and both - // entries will have the same label. Though this works just fine, it - // may seem a bit redundant. In theory, we could check here to - // determine if stmt knows how to handle its own label; for example, - // stmt happens to be a WhileStatement and so we know it's going to - // establish its own LoopEntry when we explode it (below). Then this - // LabeledEntry would be unnecessary. Alternatively, we might be - // tempted not to pass stmt.label down into self.explodeStatement, - // because we've handled the label here, but that's a mistake because - // labeled loops may contain labeled continue statements, which is not - // something we can handle in this generic case. All in all, I think a - // little redundancy greatly simplifies the logic of this case, since - // it's clear that we handle all possible LabeledStatements correctly - // here, regardless of whether they interact with the leap manager - // themselves. Also remember that labels and break/continue-to-label - // statements are rare, and all of this logic happens at transform - // time, so it has no additional runtime cost. - self.leapManager.withEntry( - new leap.LabeledEntry(after, stmt.label), - function() { - self.explodeStatement(path.get("body"), stmt.label); - } - ); - - self.mark(after); - - break; - - case "WhileStatement": - before = loc(); - after = loc(); - - self.mark(before); - self.jumpIfNot(self.explodeExpression(path.get("test")), after); - self.leapManager.withEntry( - new leap.LoopEntry(after, before, labelId), - function() { self.explodeStatement(path.get("body")); } - ); - self.jump(before); - self.mark(after); - - break; - - case "DoWhileStatement": - let first = loc(); - let test = loc(); - after = loc(); - - self.mark(first); - self.leapManager.withEntry( - new leap.LoopEntry(after, test, labelId), - function() { self.explode(path.get("body")); } - ); - self.mark(test); - self.jumpIf(self.explodeExpression(path.get("test")), first); - self.mark(after); - - break; - - case "ForStatement": - head = loc(); - let update = loc(); - after = loc(); - - if (stmt.init) { - // We pass true here to indicate that if stmt.init is an expression - // then we do not care about its result. - self.explode(path.get("init"), true); - } - - self.mark(head); - - if (stmt.test) { - self.jumpIfNot(self.explodeExpression(path.get("test")), after); - } else { - // No test means continue unconditionally. - } - - self.leapManager.withEntry( - new leap.LoopEntry(after, update, labelId), - function() { self.explodeStatement(path.get("body")); } - ); - - self.mark(update); - - if (stmt.update) { - // We pass true here to indicate that if stmt.update is an - // expression then we do not care about its result. - self.explode(path.get("update"), true); - } - - self.jump(head); - - self.mark(after); - - break; - - case "TypeCastExpression": - return self.explodeExpression(path.get("expression")); - - case "ForInStatement": - head = loc(); - after = loc(); - - let keyIterNextFn = self.makeTempVar(); - self.emitAssign( - keyIterNextFn, - t.callExpression( - util.runtimeProperty("keys"), - [self.explodeExpression(path.get("right"))] - ) - ); - - self.mark(head); - - let keyInfoTmpVar = self.makeTempVar(); - self.jumpIf( - t.memberExpression( - t.assignmentExpression( - "=", - keyInfoTmpVar, - t.callExpression(keyIterNextFn, []) - ), - t.identifier("done"), - false - ), - after - ); - - self.emitAssign( - stmt.left, - t.memberExpression( - keyInfoTmpVar, - t.identifier("value"), - false - ) - ); - - self.leapManager.withEntry( - new leap.LoopEntry(after, head, labelId), - function() { self.explodeStatement(path.get("body")); } - ); - - self.jump(head); - - self.mark(after); - - break; - - case "BreakStatement": - self.emitAbruptCompletion({ - type: "break", - target: self.leapManager.getBreakLoc(stmt.label) - }); - - break; - - case "ContinueStatement": - self.emitAbruptCompletion({ - type: "continue", - target: self.leapManager.getContinueLoc(stmt.label) - }); - - break; - - case "SwitchStatement": - // Always save the discriminant into a temporary variable in case the - // test expressions overwrite values like context.sent. - let disc = self.emitAssign( - self.makeTempVar(), - self.explodeExpression(path.get("discriminant")) - ); - - after = loc(); - let defaultLoc = loc(); - let condition = defaultLoc; - let caseLocs = []; - - // If there are no cases, .cases might be undefined. - let cases = stmt.cases || []; - - for (let i = cases.length - 1; i >= 0; --i) { - let c = cases[i]; - t.assertSwitchCase(c); - - if (c.test) { - condition = t.conditionalExpression( - t.binaryExpression("===", disc, c.test), - caseLocs[i] = loc(), - condition - ); - } else { - caseLocs[i] = defaultLoc; - } - } - - let discriminant = path.get("discriminant"); - discriminant.replaceWith(condition); - self.jump(self.explodeExpression(discriminant)); - - self.leapManager.withEntry( - new leap.SwitchEntry(after), - function() { - path.get("cases").forEach(function(casePath) { - let i = casePath.key; - self.mark(caseLocs[i]); - - casePath.get("consequent").forEach(function (path) { - self.explodeStatement(path); - }); - }); - } - ); - - self.mark(after); - if (defaultLoc.value === -1) { - self.mark(defaultLoc); - assert.strictEqual(after.value, defaultLoc.value); - } - - break; - - case "IfStatement": - let elseLoc = stmt.alternate && loc(); - after = loc(); - - self.jumpIfNot( - self.explodeExpression(path.get("test")), - elseLoc || after - ); - - self.explodeStatement(path.get("consequent")); - - if (elseLoc) { - self.jump(after); - self.mark(elseLoc); - self.explodeStatement(path.get("alternate")); - } - - self.mark(after); - - break; - - case "ReturnStatement": - self.emitAbruptCompletion({ - type: "return", - value: self.explodeExpression(path.get("argument")) - }); - - break; - - case "WithStatement": - throw new Error("WithStatement not supported in generator functions."); - - case "TryStatement": - after = loc(); - - let handler = stmt.handler; - - let catchLoc = handler && loc(); - let catchEntry = catchLoc && new leap.CatchEntry( - catchLoc, - handler.param - ); - - let finallyLoc = stmt.finalizer && loc(); - let finallyEntry = finallyLoc && - new leap.FinallyEntry(finallyLoc, after); - - let tryEntry = new leap.TryEntry( - self.getUnmarkedCurrentLoc(), - catchEntry, - finallyEntry - ); - - self.tryEntries.push(tryEntry); - self.updateContextPrevLoc(tryEntry.firstLoc); - - self.leapManager.withEntry(tryEntry, function() { - self.explodeStatement(path.get("block")); - - if (catchLoc) { - if (finallyLoc) { - // If we have both a catch block and a finally block, then - // because we emit the catch block first, we need to jump over - // it to the finally block. - self.jump(finallyLoc); - - } else { - // If there is no finally block, then we need to jump over the - // catch block to the fall-through location. - self.jump(after); - } - - self.updateContextPrevLoc(self.mark(catchLoc)); - - let bodyPath = path.get("handler.body"); - let safeParam = self.makeTempVar(); - self.clearPendingException(tryEntry.firstLoc, safeParam); - - bodyPath.traverse(catchParamVisitor, { - safeParam: safeParam, - catchParamName: handler.param.name - }); - - self.leapManager.withEntry(catchEntry, function() { - self.explodeStatement(bodyPath); - }); - } - - if (finallyLoc) { - self.updateContextPrevLoc(self.mark(finallyLoc)); - - self.leapManager.withEntry(finallyEntry, function() { - self.explodeStatement(path.get("finalizer")); - }); - - self.emit(t.returnStatement(t.callExpression( - self.contextProperty("finish"), - [finallyEntry.firstLoc] - ))); - } - }); - - self.mark(after); - - break; - - case "ThrowStatement": - self.emit(t.throwStatement( - self.explodeExpression(path.get("argument")) - )); - - break; - - default: - throw new Error( - "unknown Statement of type " + - JSON.stringify(stmt.type)); - } -}; - -let catchParamVisitor = { - Identifier: function(path, state) { - if (path.node.name === state.catchParamName && util.isReference(path)) { - path.replaceWith(state.safeParam); - } - }, - - Scope: function(path, state) { - if (path.scope.hasOwnBinding(state.catchParamName)) { - // Don't descend into nested scopes that shadow the catch - // parameter with their own declarations. - path.skip(); - } - } -}; - -Ep.emitAbruptCompletion = function(record) { - if (!isValidCompletion(record)) { - assert.ok( - false, - "invalid completion record: " + - JSON.stringify(record) - ); - } - - assert.notStrictEqual( - record.type, "normal", - "normal completions are not abrupt" - ); - - let abruptArgs = [t.stringLiteral(record.type)]; - - if (record.type === "break" || - record.type === "continue") { - t.assertLiteral(record.target); - abruptArgs[1] = record.target; - } else if (record.type === "return" || - record.type === "throw") { - if (record.value) { - t.assertExpression(record.value); - abruptArgs[1] = record.value; - } - } - - this.emit( - t.returnStatement( - t.callExpression( - this.contextProperty("abrupt"), - abruptArgs - ) - ) - ); -}; - -function isValidCompletion(record) { - let type = record.type; - - if (type === "normal") { - return !hasOwn.call(record, "target"); - } - - if (type === "break" || - type === "continue") { - return !hasOwn.call(record, "value") - && t.isLiteral(record.target); - } - - if (type === "return" || - type === "throw") { - return hasOwn.call(record, "value") - && !hasOwn.call(record, "target"); - } - - return false; -} - - -// Not all offsets into emitter.listing are potential jump targets. For -// example, execution typically falls into the beginning of a try block -// without jumping directly there. This method returns the current offset -// without marking it, so that a switch case will not necessarily be -// generated for this offset (I say "not necessarily" because the same -// location might end up being marked in the process of emitting other -// statements). There's no logical harm in marking such locations as jump -// targets, but minimizing the number of switch cases keeps the generated -// code shorter. -Ep.getUnmarkedCurrentLoc = function() { - return t.numericLiteral(this.listing.length); -}; - -// The context.prev property takes the value of context.next whenever we -// evaluate the switch statement discriminant, which is generally good -// enough for tracking the last location we jumped to, but sometimes -// context.prev needs to be more precise, such as when we fall -// successfully out of a try block and into a finally block without -// jumping. This method exists to update context.prev to the freshest -// available location. If we were implementing a full interpreter, we -// would know the location of the current instruction with complete -// precision at all times, but we don't have that luxury here, as it would -// be costly and verbose to set context.prev before every statement. -Ep.updateContextPrevLoc = function(loc) { - if (loc) { - t.assertLiteral(loc); - - if (loc.value === -1) { - // If an uninitialized location literal was passed in, set its value - // to the current this.listing.length. - loc.value = this.listing.length; - } else { - // Otherwise assert that the location matches the current offset. - assert.strictEqual(loc.value, this.listing.length); - } - - } else { - loc = this.getUnmarkedCurrentLoc(); - } - - // Make sure context.prev is up to date in case we fell into this try - // statement without jumping to it. TODO Consider avoiding this - // assignment when we know control must have jumped here. - this.emitAssign(this.contextProperty("prev"), loc); -}; - -Ep.explodeExpression = function(path, ignoreResult) { - let expr = path.node; - if (expr) { - t.assertExpression(expr); - } else { - return expr; - } - - let self = this; - let result; // Used optionally by several cases below. - let after; - - function finish(expr) { - t.assertExpression(expr); - if (ignoreResult) { - self.emit(expr); - } else { - return expr; - } - } - - // If the expression does not contain a leap, then we either emit the - // expression as a standalone statement or return it whole. - if (!meta.containsLeap(expr)) { - return finish(expr); - } - - // If any child contains a leap (such as a yield or labeled continue or - // break statement), then any sibling subexpressions will almost - // certainly have to be exploded in order to maintain the order of their - // side effects relative to the leaping child(ren). - let hasLeapingChildren = meta.containsLeap.onlyChildren(expr); - - // In order to save the rest of explodeExpression from a combinatorial - // trainwreck of special cases, explodeViaTempVar is responsible for - // deciding when a subexpression needs to be "exploded," which is my - // very technical term for emitting the subexpression as an assignment - // to a temporary variable and the substituting the temporary variable - // for the original subexpression. Think of exploded view diagrams, not - // Michael Bay movies. The point of exploding subexpressions is to - // control the precise order in which the generated code realizes the - // side effects of those subexpressions. - function explodeViaTempVar(tempVar, childPath, ignoreChildResult) { - assert.ok( - !ignoreChildResult || !tempVar, - "Ignoring the result of a child expression but forcing it to " + - "be assigned to a temporary variable?" - ); - - let result = self.explodeExpression(childPath, ignoreChildResult); - - if (ignoreChildResult) { - // Side effects already emitted above. - - } else if (tempVar || (hasLeapingChildren && - !t.isLiteral(result))) { - // If tempVar was provided, then the result will always be assigned - // to it, even if the result does not otherwise need to be assigned - // to a temporary variable. When no tempVar is provided, we have - // the flexibility to decide whether a temporary variable is really - // necessary. Unfortunately, in general, a temporary variable is - // required whenever any child contains a yield expression, since it - // is difficult to prove (at all, let alone efficiently) whether - // this result would evaluate to the same value before and after the - // yield (see #206). One narrow case where we can prove it doesn't - // matter (and thus we do not need a temporary variable) is when the - // result in question is a Literal value. - result = self.emitAssign( - tempVar || self.makeTempVar(), - result - ); - } - return result; - } - - // If ignoreResult is true, then we must take full responsibility for - // emitting the expression with all its side effects, and we should not - // return a result. - - switch (expr.type) { - case "MemberExpression": - return finish(t.memberExpression( - self.explodeExpression(path.get("object")), - expr.computed - ? explodeViaTempVar(null, path.get("property")) - : expr.property, - expr.computed - )); - - case "CallExpression": - let calleePath = path.get("callee"); - let argsPath = path.get("arguments"); - - let newCallee; - let newArgs = []; - - let hasLeapingArgs = false; - argsPath.forEach(function(argPath) { - hasLeapingArgs = hasLeapingArgs || - meta.containsLeap(argPath.node); - }); - - if (t.isMemberExpression(calleePath.node)) { - if (hasLeapingArgs) { - // If the arguments of the CallExpression contained any yield - // expressions, then we need to be sure to evaluate the callee - // before evaluating the arguments, but if the callee was a member - // expression, then we must be careful that the object of the - // member expression still gets bound to `this` for the call. - - let newObject = explodeViaTempVar( - // Assign the exploded callee.object expression to a temporary - // variable so that we can use it twice without reevaluating it. - self.makeTempVar(), - calleePath.get("object") - ); - - let newProperty = calleePath.node.computed - ? explodeViaTempVar(null, calleePath.get("property")) - : calleePath.node.property; - - newArgs.unshift(newObject); - - newCallee = t.memberExpression( - t.memberExpression( - newObject, - newProperty, - calleePath.node.computed - ), - t.identifier("call"), - false - ); - - } else { - newCallee = self.explodeExpression(calleePath); - } - - } else { - newCallee = self.explodeExpression(calleePath); - - if (t.isMemberExpression(newCallee)) { - // If the callee was not previously a MemberExpression, then the - // CallExpression was "unqualified," meaning its `this` object - // should be the global object. If the exploded expression has - // become a MemberExpression (e.g. a context property, probably a - // temporary variable), then we need to force it to be unqualified - // by using the (0, object.property)(...) trick; otherwise, it - // will receive the object of the MemberExpression as its `this` - // object. - newCallee = t.sequenceExpression([ - t.numericLiteral(0), - newCallee - ]); - } - } - - argsPath.forEach(function(argPath) { - newArgs.push(explodeViaTempVar(null, argPath)); - }); - - return finish(t.callExpression( - newCallee, - newArgs - )); - - case "NewExpression": - return finish(t.newExpression( - explodeViaTempVar(null, path.get("callee")), - path.get("arguments").map(function(argPath) { - return explodeViaTempVar(null, argPath); - }) - )); - - case "ObjectExpression": - return finish(t.objectExpression( - path.get("properties").map(function(propPath) { - if (propPath.isObjectProperty()) { - return t.objectProperty( - propPath.node.key, - explodeViaTempVar(null, propPath.get("value")), - propPath.node.computed - ); - } else { - return propPath.node; - } - }) - )); - - case "ArrayExpression": - return finish(t.arrayExpression( - path.get("elements").map(function(elemPath) { - return explodeViaTempVar(null, elemPath); - }) - )); - - case "SequenceExpression": - let lastIndex = expr.expressions.length - 1; - - path.get("expressions").forEach(function(exprPath) { - if (exprPath.key === lastIndex) { - result = self.explodeExpression(exprPath, ignoreResult); - } else { - self.explodeExpression(exprPath, true); - } - }); - - return result; - - case "LogicalExpression": - after = loc(); - - if (!ignoreResult) { - result = self.makeTempVar(); - } - - let left = explodeViaTempVar(result, path.get("left")); - - if (expr.operator === "&&") { - self.jumpIfNot(left, after); - } else { - assert.strictEqual(expr.operator, "||"); - self.jumpIf(left, after); - } - - explodeViaTempVar(result, path.get("right"), ignoreResult); - - self.mark(after); - - return result; - - case "ConditionalExpression": - let elseLoc = loc(); - after = loc(); - let test = self.explodeExpression(path.get("test")); - - self.jumpIfNot(test, elseLoc); - - if (!ignoreResult) { - result = self.makeTempVar(); - } - - explodeViaTempVar(result, path.get("consequent"), ignoreResult); - self.jump(after); - - self.mark(elseLoc); - explodeViaTempVar(result, path.get("alternate"), ignoreResult); - - self.mark(after); - - return result; - - case "UnaryExpression": - return finish(t.unaryExpression( - expr.operator, - // Can't (and don't need to) break up the syntax of the argument. - // Think about delete a[b]. - self.explodeExpression(path.get("argument")), - !!expr.prefix - )); - - case "BinaryExpression": - return finish(t.binaryExpression( - expr.operator, - explodeViaTempVar(null, path.get("left")), - explodeViaTempVar(null, path.get("right")) - )); - - case "AssignmentExpression": - return finish(t.assignmentExpression( - expr.operator, - self.explodeExpression(path.get("left")), - self.explodeExpression(path.get("right")) - )); - - case "UpdateExpression": - return finish(t.updateExpression( - expr.operator, - self.explodeExpression(path.get("argument")), - expr.prefix - )); - - case "YieldExpression": - after = loc(); - let arg = expr.argument && self.explodeExpression(path.get("argument")); - - if (arg && expr.delegate) { - let result = self.makeTempVar(); - - self.emit(t.returnStatement(t.callExpression( - self.contextProperty("delegateYield"), [ - arg, - t.stringLiteral(result.property.name), - after - ] - ))); - - self.mark(after); - - return result; - } - - self.emitAssign(self.contextProperty("next"), after); - self.emit(t.returnStatement(arg || null)); - self.mark(after); - - return self.contextProperty("sent"); - - default: - throw new Error( - "unknown Expression of type " + - JSON.stringify(expr.type)); - } -}; diff --git a/packages/babel-plugin-transform-regenerator/src/hoist.js b/packages/babel-plugin-transform-regenerator/src/hoist.js deleted file mode 100644 index cac505fdfe12..000000000000 --- a/packages/babel-plugin-transform-regenerator/src/hoist.js +++ /dev/null @@ -1,150 +0,0 @@ -/** - * Copyright (c) 2014, Facebook, Inc. - * All rights reserved. - * - * This source code is licensed under the BSD-style license found in the - * https://raw.github.com/facebook/regenerator/master/LICENSE file. An - * additional grant of patent rights can be found in the PATENTS file in - * the same directory. - */ - -import * as t from "babel-types"; -let hasOwn = Object.prototype.hasOwnProperty; - -// The hoist function takes a FunctionExpression or FunctionDeclaration -// and replaces any Declaration nodes in its body with assignments, then -// returns a VariableDeclaration containing just the names of the removed -// declarations. -exports.hoist = function(funPath) { - t.assertFunction(funPath.node); - - let vars = {}; - - function varDeclToExpr(vdec, includeIdentifiers) { - t.assertVariableDeclaration(vdec); - // TODO assert.equal(vdec.kind, "var"); - let exprs = []; - - vdec.declarations.forEach(function(dec) { - // Note: We duplicate 'dec.id' here to ensure that the variable declaration IDs don't - // have the same 'loc' value, since that can make sourcemaps and retainLines behave poorly. - vars[dec.id.name] = t.identifier(dec.id.name); - - if (dec.init) { - exprs.push(t.assignmentExpression( - "=", dec.id, dec.init - )); - } else if (includeIdentifiers) { - exprs.push(dec.id); - } - }); - - if (exprs.length === 0) - return null; - - if (exprs.length === 1) - return exprs[0]; - - return t.sequenceExpression(exprs); - } - - funPath.get("body").traverse({ - VariableDeclaration: { - exit: function(path) { - let expr = varDeclToExpr(path.node, false); - if (expr === null) { - path.remove(); - } else { - // We don't need to traverse this expression any further because - // there can't be any new declarations inside an expression. - path.replaceWith(t.expressionStatement(expr)); - } - - // Since the original node has been either removed or replaced, - // avoid traversing it any further. - path.skip(); - } - }, - - ForStatement: function(path) { - let init = path.node.init; - if (t.isVariableDeclaration(init)) { - path.get("init").replaceWith(varDeclToExpr(init, false)); - } - }, - - ForXStatement: function(path) { - let left = path.get("left"); - if (left.isVariableDeclaration()) { - left.replaceWith(varDeclToExpr(left.node, true)); - } - }, - - FunctionDeclaration: function(path) { - let node = path.node; - vars[node.id.name] = node.id; - - let assignment = t.expressionStatement( - t.assignmentExpression( - "=", - node.id, - t.functionExpression( - node.id, - node.params, - node.body, - node.generator, - node.expression - ) - ) - ); - - if (path.parentPath.isBlockStatement()) { - // Insert the assignment form before the first statement in the - // enclosing block. - path.parentPath.unshiftContainer("body", assignment); - - // Remove the function declaration now that we've inserted the - // equivalent assignment form at the beginning of the block. - path.remove(); - } else { - // If the parent node is not a block statement, then we can just - // replace the declaration with the equivalent assignment form - // without worrying about hoisting it. - path.replaceWith(assignment); - } - - // Don't hoist variables out of inner functions. - path.skip(); - }, - - FunctionExpression: function(path) { - // Don't descend into nested function expressions. - path.skip(); - } - }); - - let paramNames = {}; - funPath.get("params").forEach(function(paramPath) { - let param = paramPath.node; - if (t.isIdentifier(param)) { - paramNames[param.name] = param; - } else { - // Variables declared by destructuring parameter patterns will be - // harmlessly re-declared. - } - }); - - let declarations = []; - - Object.keys(vars).forEach(function(name) { - if (!hasOwn.call(paramNames, name)) { - declarations.push(t.variableDeclarator(vars[name], null)); - } - }); - - if (declarations.length === 0) { - return null; // Be sure to handle this case! - } - - return t.variableDeclaration("var", declarations); -}; diff --git a/packages/babel-plugin-transform-regenerator/src/index.js b/packages/babel-plugin-transform-regenerator/src/index.js index 34fea7a15a98..ba3acbf5b92f 100644 --- a/packages/babel-plugin-transform-regenerator/src/index.js +++ b/packages/babel-plugin-transform-regenerator/src/index.js @@ -8,6 +8,4 @@ * the same directory. */ -export default function () { - return require("./visit"); -} +export default require("regenerator-transform"); diff --git a/packages/babel-plugin-transform-regenerator/src/leap.js b/packages/babel-plugin-transform-regenerator/src/leap.js deleted file mode 100644 index 047a2bf263a4..000000000000 --- a/packages/babel-plugin-transform-regenerator/src/leap.js +++ /dev/null @@ -1,174 +0,0 @@ -/** - * Copyright (c) 2014, Facebook, Inc. - * All rights reserved. - * - * This source code is licensed under the BSD-style license found in the - * https://raw.github.com/facebook/regenerator/master/LICENSE file. An - * additional grant of patent rights can be found in the PATENTS file in - * the same directory. - */ - -import assert from "assert"; -import * as t from "babel-types"; -import { inherits } from "util"; - -function Entry() { - assert.ok(this instanceof Entry); -} - -function FunctionEntry(returnLoc) { - Entry.call(this); - t.assertLiteral(returnLoc); - this.returnLoc = returnLoc; -} - -inherits(FunctionEntry, Entry); -exports.FunctionEntry = FunctionEntry; - -function LoopEntry(breakLoc, continueLoc, label) { - Entry.call(this); - - t.assertLiteral(breakLoc); - t.assertLiteral(continueLoc); - - if (label) { - t.assertIdentifier(label); - } else { - label = null; - } - - this.breakLoc = breakLoc; - this.continueLoc = continueLoc; - this.label = label; -} - -inherits(LoopEntry, Entry); -exports.LoopEntry = LoopEntry; - -function SwitchEntry(breakLoc) { - Entry.call(this); - t.assertLiteral(breakLoc); - this.breakLoc = breakLoc; -} - -inherits(SwitchEntry, Entry); -exports.SwitchEntry = SwitchEntry; - -function TryEntry(firstLoc, catchEntry, finallyEntry) { - Entry.call(this); - - t.assertLiteral(firstLoc); - - if (catchEntry) { - assert.ok(catchEntry instanceof CatchEntry); - } else { - catchEntry = null; - } - - if (finallyEntry) { - assert.ok(finallyEntry instanceof FinallyEntry); - } else { - finallyEntry = null; - } - - // Have to have one or the other (or both). - assert.ok(catchEntry || finallyEntry); - - this.firstLoc = firstLoc; - this.catchEntry = catchEntry; - this.finallyEntry = finallyEntry; -} - -inherits(TryEntry, Entry); -exports.TryEntry = TryEntry; - -function CatchEntry(firstLoc, paramId) { - Entry.call(this); - - t.assertLiteral(firstLoc); - t.assertIdentifier(paramId); - - this.firstLoc = firstLoc; - this.paramId = paramId; -} - -inherits(CatchEntry, Entry); -exports.CatchEntry = CatchEntry; - -function FinallyEntry(firstLoc, afterLoc) { - Entry.call(this); - t.assertLiteral(firstLoc); - t.assertLiteral(afterLoc); - this.firstLoc = firstLoc; - this.afterLoc = afterLoc; -} - -inherits(FinallyEntry, Entry); -exports.FinallyEntry = FinallyEntry; - -function LabeledEntry(breakLoc, label) { - Entry.call(this); - - t.assertLiteral(breakLoc); - t.assertIdentifier(label); - - this.breakLoc = breakLoc; - this.label = label; -} - -inherits(LabeledEntry, Entry); -exports.LabeledEntry = LabeledEntry; - -function LeapManager(emitter) { - assert.ok(this instanceof LeapManager); - - let Emitter = require("./emit").Emitter; - assert.ok(emitter instanceof Emitter); - - this.emitter = emitter; - this.entryStack = [new FunctionEntry(emitter.finalLoc)]; -} - -let LMp = LeapManager.prototype; -exports.LeapManager = LeapManager; - -LMp.withEntry = function(entry, callback) { - assert.ok(entry instanceof Entry); - this.entryStack.push(entry); - try { - callback.call(this.emitter); - } finally { - let popped = this.entryStack.pop(); - assert.strictEqual(popped, entry); - } -}; - -LMp._findLeapLocation = function(property, label) { - for (let i = this.entryStack.length - 1; i >= 0; --i) { - let entry = this.entryStack[i]; - let loc = entry[property]; - if (loc) { - if (label) { - if (entry.label && - entry.label.name === label.name) { - return loc; - } - } else if (entry instanceof LabeledEntry) { - // Ignore LabeledEntry entries unless we are actually breaking to - // a label. - } else { - return loc; - } - } - } - - return null; -}; - -LMp.getBreakLoc = function(label) { - return this._findLeapLocation("breakLoc", label); -}; - -LMp.getContinueLoc = function(label) { - return this._findLeapLocation("continueLoc", label); -}; diff --git a/packages/babel-plugin-transform-regenerator/src/meta.js b/packages/babel-plugin-transform-regenerator/src/meta.js deleted file mode 100644 index dc7ffcdd45a1..000000000000 --- a/packages/babel-plugin-transform-regenerator/src/meta.js +++ /dev/null @@ -1,103 +0,0 @@ -/** - * Copyright (c) 2014, Facebook, Inc. - * All rights reserved. - * - * This source code is licensed under the BSD-style license found in the - * https://raw.github.com/facebook/regenerator/master/LICENSE file. An - * additional grant of patent rights can be found in the PATENTS file in - * the same directory. - */ - -import assert from "assert"; -let m = require("private").makeAccessor(); -import * as t from "babel-types"; -let hasOwn = Object.prototype.hasOwnProperty; - -function makePredicate(propertyName, knownTypes) { - function onlyChildren(node) { - t.assertNode(node); - - // Assume no side effects until we find out otherwise. - let result = false; - - function check(child) { - if (result) { - // Do nothing. - } else if (Array.isArray(child)) { - child.some(check); - } else if (t.isNode(child)) { - assert.strictEqual(result, false); - result = predicate(child); - } - return result; - } - - let keys = t.VISITOR_KEYS[node.type]; - if (keys) { - for (let i = 0; i < keys.length; i++) { - let key = keys[i]; - let child = node[key]; - check(child); - } - } - - return result; - } - - function predicate(node) { - t.assertNode(node); - - let meta = m(node); - if (hasOwn.call(meta, propertyName)) - return meta[propertyName]; - - // Certain types are "opaque," which means they have no side - // effects or leaps and we don't care about their subexpressions. - if (hasOwn.call(opaqueTypes, node.type)) - return meta[propertyName] = false; - - if (hasOwn.call(knownTypes, node.type)) - return meta[propertyName] = true; - - return meta[propertyName] = onlyChildren(node); - } - - predicate.onlyChildren = onlyChildren; - - return predicate; -} - -let opaqueTypes = { - FunctionExpression: true -}; - -// These types potentially have side effects regardless of what side -// effects their subexpressions have. -let sideEffectTypes = { - CallExpression: true, // Anything could happen! - ForInStatement: true, // Modifies the key variable. - UnaryExpression: true, // Think delete. - BinaryExpression: true, // Might invoke .toString() or .valueOf(). - AssignmentExpression: true, // Side-effecting by definition. - UpdateExpression: true, // Updates are essentially assignments. - NewExpression: true // Similar to CallExpression. -}; - -// These types are the direct cause of all leaps in control flow. -let leapTypes = { - YieldExpression: true, - BreakStatement: true, - ContinueStatement: true, - ReturnStatement: true, - ThrowStatement: true -}; - -// All leap types are also side effect types. -for (let type in leapTypes) { - if (hasOwn.call(leapTypes, type)) { - sideEffectTypes[type] = leapTypes[type]; - } -} - -exports.hasSideEffects = makePredicate("hasSideEffects", sideEffectTypes); -exports.containsLeap = makePredicate("containsLeap", leapTypes); diff --git a/packages/babel-plugin-transform-regenerator/src/util.js b/packages/babel-plugin-transform-regenerator/src/util.js deleted file mode 100644 index 78bfa0f28b10..000000000000 --- a/packages/babel-plugin-transform-regenerator/src/util.js +++ /dev/null @@ -1,23 +0,0 @@ -/** - * Copyright (c) 2014, Facebook, Inc. - * All rights reserved. - * - * This source code is licensed under the BSD-style license found in the - * https://raw.github.com/facebook/regenerator/master/LICENSE file. An - * additional grant of patent rights can be found in the PATENTS file in - * the same directory. - */ - -import * as t from "babel-types"; - -export function runtimeProperty(name) { - return t.memberExpression( - t.identifier("regeneratorRuntime"), - t.identifier(name), - false - ); -} - -export function isReference(path) { - return path.isReferenced() || path.parentPath.isAssignmentExpression({ left: path.node }); -} diff --git a/packages/babel-plugin-transform-regenerator/src/visit.js b/packages/babel-plugin-transform-regenerator/src/visit.js deleted file mode 100644 index 8d96f2b40495..000000000000 --- a/packages/babel-plugin-transform-regenerator/src/visit.js +++ /dev/null @@ -1,269 +0,0 @@ -/** - * Copyright (c) 2014, Facebook, Inc. - * All rights reserved. - * - * This source code is licensed under the BSD-style license found in the - * https://raw.github.com/facebook/regenerator/master/LICENSE file. An - * additional grant of patent rights can be found in the PATENTS file in - * the same directory. - */ - -import assert from "assert"; -import * as t from "babel-types"; -import { hoist } from "./hoist"; -import { Emitter } from "./emit"; -import * as util from "./util"; - -let getMarkInfo = require("private").makeAccessor(); - -exports.visitor = { - Function: { - exit: function(path, state) { - let node = path.node; - - if (node.generator) { - if (node.async) { - // Async generator - if (state.opts.asyncGenerators === false) return; - } else { - // Plain generator - if (state.opts.generators === false) return; - } - } else if (node.async) { - // Async function - if (state.opts.async === false) return; - } else { - // Not a generator or async function. - return; - } - - let contextId = path.scope.generateUidIdentifier("context"); - let argsId = path.scope.generateUidIdentifier("args"); - - path.ensureBlock(); - let bodyBlockPath = path.get("body"); - - if (node.async) { - bodyBlockPath.traverse(awaitVisitor); - } - - bodyBlockPath.traverse(functionSentVisitor, { - context: contextId - }); - - let outerBody = []; - let innerBody = []; - - bodyBlockPath.get("body").forEach(function(childPath) { - let node = childPath.node; - if (node && node._blockHoist != null) { - outerBody.push(node); - } else { - innerBody.push(node); - } - }); - - if (outerBody.length > 0) { - // Only replace the inner body if we actually hoisted any statements - // to the outer body. - bodyBlockPath.node.body = innerBody; - } - - let outerFnExpr = getOuterFnExpr(path); - // Note that getOuterFnExpr has the side-effect of ensuring that the - // function has a name (so node.id will always be an Identifier), even - // if a temporary name has to be synthesized. - t.assertIdentifier(node.id); - let innerFnId = t.identifier(node.id.name + "$"); - - // Turn all declarations into vars, and replace the original - // declarations with equivalent assignment expressions. - let vars = hoist(path); - - let didRenameArguments = renameArguments(path, argsId); - if (didRenameArguments) { - vars = vars || t.variableDeclaration("var", []); - vars.declarations.push(t.variableDeclarator( - argsId, t.identifier("arguments") - )); - } - - let emitter = new Emitter(contextId); - emitter.explode(path.get("body")); - - if (vars && vars.declarations.length > 0) { - outerBody.push(vars); - } - - let wrapArgs = [ - emitter.getContextFunction(innerFnId), - // Async functions that are not generators don't care about the - // outer function because they don't need it to be marked and don't - // inherit from its .prototype. - node.generator ? outerFnExpr : t.nullLiteral(), - t.thisExpression() - ]; - - let tryLocsList = emitter.getTryLocsList(); - if (tryLocsList) { - wrapArgs.push(tryLocsList); - } - - let wrapCall = t.callExpression( - util.runtimeProperty(node.async ? "async" : "wrap"), - wrapArgs - ); - - outerBody.push(t.returnStatement(wrapCall)); - node.body = t.blockStatement(outerBody); - - let wasGeneratorFunction = node.generator; - if (wasGeneratorFunction) { - node.generator = false; - } - - if (node.async) { - node.async = false; - } - - if (wasGeneratorFunction && t.isExpression(node)) { - path.replaceWith(t.callExpression(util.runtimeProperty("mark"), [node])); - } - - // Generators are processed in 'exit' handlers so that regenerator only has to run on - // an ES5 AST, but that means traversal will not pick up newly inserted references - // to things like 'regeneratorRuntime'. To avoid this, we explicitly requeue. - path.requeue(); - } - } -}; - -// Given a NodePath for a Function, return an Expression node that can be -// used to refer reliably to the function object from inside the function. -// This expression is essentially a replacement for arguments.callee, with -// the key advantage that it works in strict mode. -function getOuterFnExpr(funPath) { - let node = funPath.node; - t.assertFunction(node); - - if (!node.id) { - // Default-exported function declarations, and function expressions may not - // have a name to reference, so we explicitly add one. - node.id = funPath.scope.parent.generateUidIdentifier("callee"); - } - - if (node.generator && // Non-generator functions don't need to be marked. - t.isFunctionDeclaration(node)) { - let pp = funPath.findParent(function (path) { - return path.isProgram() || path.isBlockStatement(); - }); - - if (!pp) { - return node.id; - } - - let markDecl = getRuntimeMarkDecl(pp); - let markedArray = markDecl.declarations[0].id; - let funDeclIdArray = markDecl.declarations[0].init.callee.object; - t.assertArrayExpression(funDeclIdArray); - - let index = funDeclIdArray.elements.length; - funDeclIdArray.elements.push(node.id); - - return t.memberExpression( - markedArray, - t.numericLiteral(index), - true - ); - } - - return node.id; -} - -function getRuntimeMarkDecl(blockPath) { - let block = blockPath.node; - assert.ok(Array.isArray(block.body)); - - let info = getMarkInfo(block); - if (info.decl) { - return info.decl; - } - - info.decl = t.variableDeclaration("var", [ - t.variableDeclarator( - blockPath.scope.generateUidIdentifier("marked"), - t.callExpression( - t.memberExpression( - t.arrayExpression([]), - t.identifier("map"), - false - ), - [util.runtimeProperty("mark")] - ) - ) - ]); - - blockPath.unshiftContainer("body", info.decl); - - return info.decl; -} - -function renameArguments(funcPath, argsId) { - let state = { - didRenameArguments: false, - argsId: argsId - }; - - funcPath.traverse(argumentsVisitor, state); - - // If the traversal replaced any arguments references, then we need to - // alias the outer function's arguments binding (be it the implicit - // arguments object or some other parameter or variable) to the variable - // named by argsId. - return state.didRenameArguments; -} - -let argumentsVisitor = { - "FunctionExpression|FunctionDeclaration": function(path) { - path.skip(); - }, - - Identifier: function(path, state) { - if (path.node.name === "arguments" && util.isReference(path)) { - path.replaceWith(state.argsId); - state.didRenameArguments = true; - } - } -}; - -let functionSentVisitor = { - MetaProperty(path) { - let { node } = path; - - if (node.meta.name === "function" && node.property.name === "sent") { - path.replaceWith(t.memberExpression(this.context, t.identifier("_sent"))); - } - } -}; - -let awaitVisitor = { - Function: function(path) { - path.skip(); // Don't descend into nested function scopes. - }, - - AwaitExpression: function(path) { - // Convert await expressions to yield expressions. - let argument = path.node.argument; - - // Transforming `await x` to `yield regeneratorRuntime.awrap(x)` - // causes the argument to be wrapped in such a way that the runtime - // can distinguish between awaited and merely yielded values. - path.replaceWith(t.yieldExpression( - t.callExpression( - util.runtimeProperty("awrap"), - [argument] - ), - false - )); - } -};