--- /dev/null
+/*
+ Copyright (C) 2015 Yusuke Suzuki <utatane.tea@gmail.com>
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+ DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+"use strict";
+
+/* eslint-disable no-underscore-dangle */
+/* eslint-disable no-undefined */
+
+const Syntax = require("estraverse").Syntax;
+
+const Reference = require("./reference");
+const Variable = require("./variable");
+const Definition = require("./definition").Definition;
+const assert = require("assert");
+
+/**
+ * Test if scope is struct
+ * @param {Scope} scope - scope
+ * @param {Block} block - block
+ * @param {boolean} isMethodDefinition - is method definiton
+ * @param {boolean} useDirective - use directive
+ * @returns {boolean} is strict scope
+ */
+function isStrictScope(scope, block, isMethodDefinition, useDirective) {
+ let body;
+
+ // When upper scope is exists and strict, inner scope is also strict.
+ if (scope.upper && scope.upper.isStrict) {
+ return true;
+ }
+
+ if (isMethodDefinition) {
+ return true;
+ }
+
+ if (scope.type === "class" || scope.type === "module") {
+ return true;
+ }
+
+ if (scope.type === "block" || scope.type === "switch") {
+ return false;
+ }
+
+ if (scope.type === "function") {
+ if (block.type === Syntax.ArrowFunctionExpression && block.body.type !== Syntax.BlockStatement) {
+ return false;
+ }
+
+ if (block.type === Syntax.Program) {
+ body = block;
+ } else {
+ body = block.body;
+ }
+
+ if (!body) {
+ return false;
+ }
+ } else if (scope.type === "global") {
+ body = block;
+ } else {
+ return false;
+ }
+
+ // Search 'use strict' directive.
+ if (useDirective) {
+ for (let i = 0, iz = body.body.length; i < iz; ++i) {
+ const stmt = body.body[i];
+
+ if (stmt.type !== Syntax.DirectiveStatement) {
+ break;
+ }
+ if (stmt.raw === "\"use strict\"" || stmt.raw === "'use strict'") {
+ return true;
+ }
+ }
+ } else {
+ for (let i = 0, iz = body.body.length; i < iz; ++i) {
+ const stmt = body.body[i];
+
+ if (stmt.type !== Syntax.ExpressionStatement) {
+ break;
+ }
+ const expr = stmt.expression;
+
+ if (expr.type !== Syntax.Literal || typeof expr.value !== "string") {
+ break;
+ }
+ if (expr.raw !== null && expr.raw !== undefined) {
+ if (expr.raw === "\"use strict\"" || expr.raw === "'use strict'") {
+ return true;
+ }
+ } else {
+ if (expr.value === "use strict") {
+ return true;
+ }
+ }
+ }
+ }
+ return false;
+}
+
+/**
+ * Register scope
+ * @param {ScopeManager} scopeManager - scope manager
+ * @param {Scope} scope - scope
+ * @returns {void}
+ */
+function registerScope(scopeManager, scope) {
+ scopeManager.scopes.push(scope);
+
+ const scopes = scopeManager.__nodeToScope.get(scope.block);
+
+ if (scopes) {
+ scopes.push(scope);
+ } else {
+ scopeManager.__nodeToScope.set(scope.block, [scope]);
+ }
+}
+
+/**
+ * Should be statically
+ * @param {Object} def - def
+ * @returns {boolean} should be statically
+ */
+function shouldBeStatically(def) {
+ return (
+ (def.type === Variable.ClassName) ||
+ (def.type === Variable.Variable && def.parent.kind !== "var")
+ );
+}
+
+/**
+ * @class Scope
+ */
+class Scope {
+ constructor(scopeManager, type, upperScope, block, isMethodDefinition) {
+
+ /**
+ * One of 'module', 'block', 'switch', 'function', 'catch', 'with', 'function', 'class', 'global'.
+ * @member {String} Scope#type
+ */
+ this.type = type;
+
+ /**
+ * The scoped {@link Variable}s of this scope, as <code>{ Variable.name
+ * : Variable }</code>.
+ * @member {Map} Scope#set
+ */
+ this.set = new Map();
+
+ /**
+ * The tainted variables of this scope, as <code>{ Variable.name :
+ * boolean }</code>.
+ * @member {Map} Scope#taints */
+ this.taints = new Map();
+
+ /**
+ * Generally, through the lexical scoping of JS you can always know
+ * which variable an identifier in the source code refers to. There are
+ * a few exceptions to this rule. With 'global' and 'with' scopes you
+ * can only decide at runtime which variable a reference refers to.
+ * Moreover, if 'eval()' is used in a scope, it might introduce new
+ * bindings in this or its parent scopes.
+ * All those scopes are considered 'dynamic'.
+ * @member {boolean} Scope#dynamic
+ */
+ this.dynamic = this.type === "global" || this.type === "with";
+
+ /**
+ * A reference to the scope-defining syntax node.
+ * @member {espree.Node} Scope#block
+ */
+ this.block = block;
+
+ /**
+ * The {@link Reference|references} that are not resolved with this scope.
+ * @member {Reference[]} Scope#through
+ */
+ this.through = [];
+
+ /**
+ * The scoped {@link Variable}s of this scope. In the case of a
+ * 'function' scope this includes the automatic argument <em>arguments</em> as
+ * its first element, as well as all further formal arguments.
+ * @member {Variable[]} Scope#variables
+ */
+ this.variables = [];
+
+ /**
+ * Any variable {@link Reference|reference} found in this scope. This
+ * includes occurrences of local variables as well as variables from
+ * parent scopes (including the global scope). For local variables
+ * this also includes defining occurrences (like in a 'var' statement).
+ * In a 'function' scope this does not include the occurrences of the
+ * formal parameter in the parameter list.
+ * @member {Reference[]} Scope#references
+ */
+ this.references = [];
+
+ /**
+ * For 'global' and 'function' scopes, this is a self-reference. For
+ * other scope types this is the <em>variableScope</em> value of the
+ * parent scope.
+ * @member {Scope} Scope#variableScope
+ */
+ this.variableScope =
+ (this.type === "global" || this.type === "function" || this.type === "module") ? this : upperScope.variableScope;
+
+ /**
+ * Whether this scope is created by a FunctionExpression.
+ * @member {boolean} Scope#functionExpressionScope
+ */
+ this.functionExpressionScope = false;
+
+ /**
+ * Whether this is a scope that contains an 'eval()' invocation.
+ * @member {boolean} Scope#directCallToEvalScope
+ */
+ this.directCallToEvalScope = false;
+
+ /**
+ * @member {boolean} Scope#thisFound
+ */
+ this.thisFound = false;
+
+ this.__left = [];
+
+ /**
+ * Reference to the parent {@link Scope|scope}.
+ * @member {Scope} Scope#upper
+ */
+ this.upper = upperScope;
+
+ /**
+ * Whether 'use strict' is in effect in this scope.
+ * @member {boolean} Scope#isStrict
+ */
+ this.isStrict = isStrictScope(this, block, isMethodDefinition, scopeManager.__useDirective());
+
+ /**
+ * List of nested {@link Scope}s.
+ * @member {Scope[]} Scope#childScopes
+ */
+ this.childScopes = [];
+ if (this.upper) {
+ this.upper.childScopes.push(this);
+ }
+
+ this.__declaredVariables = scopeManager.__declaredVariables;
+
+ registerScope(scopeManager, this);
+ }
+
+ __shouldStaticallyClose(scopeManager) {
+ return (!this.dynamic || scopeManager.__isOptimistic());
+ }
+
+ __shouldStaticallyCloseForGlobal(ref) {
+
+ // On global scope, let/const/class declarations should be resolved statically.
+ const name = ref.identifier.name;
+
+ if (!this.set.has(name)) {
+ return false;
+ }
+
+ const variable = this.set.get(name);
+ const defs = variable.defs;
+
+ return defs.length > 0 && defs.every(shouldBeStatically);
+ }
+
+ __staticCloseRef(ref) {
+ if (!this.__resolve(ref)) {
+ this.__delegateToUpperScope(ref);
+ }
+ }
+
+ __dynamicCloseRef(ref) {
+
+ // notify all names are through to global
+ let current = this;
+
+ do {
+ current.through.push(ref);
+ current = current.upper;
+ } while (current);
+ }
+
+ __globalCloseRef(ref) {
+
+ // let/const/class declarations should be resolved statically.
+ // others should be resolved dynamically.
+ if (this.__shouldStaticallyCloseForGlobal(ref)) {
+ this.__staticCloseRef(ref);
+ } else {
+ this.__dynamicCloseRef(ref);
+ }
+ }
+
+ __close(scopeManager) {
+ let closeRef;
+
+ if (this.__shouldStaticallyClose(scopeManager)) {
+ closeRef = this.__staticCloseRef;
+ } else if (this.type !== "global") {
+ closeRef = this.__dynamicCloseRef;
+ } else {
+ closeRef = this.__globalCloseRef;
+ }
+
+ // Try Resolving all references in this scope.
+ for (let i = 0, iz = this.__left.length; i < iz; ++i) {
+ const ref = this.__left[i];
+
+ closeRef.call(this, ref);
+ }
+ this.__left = null;
+
+ return this.upper;
+ }
+
+ // To override by function scopes.
+ // References in default parameters isn't resolved to variables which are in their function body.
+ __isValidResolution(ref, variable) { // eslint-disable-line class-methods-use-this, no-unused-vars
+ return true;
+ }
+
+ __resolve(ref) {
+ const name = ref.identifier.name;
+
+ if (!this.set.has(name)) {
+ return false;
+ }
+ const variable = this.set.get(name);
+
+ if (!this.__isValidResolution(ref, variable)) {
+ return false;
+ }
+ variable.references.push(ref);
+ variable.stack = variable.stack && ref.from.variableScope === this.variableScope;
+ if (ref.tainted) {
+ variable.tainted = true;
+ this.taints.set(variable.name, true);
+ }
+ ref.resolved = variable;
+
+ return true;
+ }
+
+ __delegateToUpperScope(ref) {
+ if (this.upper) {
+ this.upper.__left.push(ref);
+ }
+ this.through.push(ref);
+ }
+
+ __addDeclaredVariablesOfNode(variable, node) {
+ if (node === null || node === undefined) {
+ return;
+ }
+
+ let variables = this.__declaredVariables.get(node);
+
+ if (variables === null || variables === undefined) {
+ variables = [];
+ this.__declaredVariables.set(node, variables);
+ }
+ if (variables.indexOf(variable) === -1) {
+ variables.push(variable);
+ }
+ }
+
+ __defineGeneric(name, set, variables, node, def) {
+ let variable;
+
+ variable = set.get(name);
+ if (!variable) {
+ variable = new Variable(name, this);
+ set.set(name, variable);
+ variables.push(variable);
+ }
+
+ if (def) {
+ variable.defs.push(def);
+ this.__addDeclaredVariablesOfNode(variable, def.node);
+ this.__addDeclaredVariablesOfNode(variable, def.parent);
+ }
+ if (node) {
+ variable.identifiers.push(node);
+ }
+ }
+
+ __define(node, def) {
+ if (node && node.type === Syntax.Identifier) {
+ this.__defineGeneric(
+ node.name,
+ this.set,
+ this.variables,
+ node,
+ def
+ );
+ }
+ }
+
+ __referencing(node, assign, writeExpr, maybeImplicitGlobal, partial, init) {
+
+ // because Array element may be null
+ if (!node || node.type !== Syntax.Identifier) {
+ return;
+ }
+
+ // Specially handle like `this`.
+ if (node.name === "super") {
+ return;
+ }
+
+ const ref = new Reference(node, this, assign || Reference.READ, writeExpr, maybeImplicitGlobal, !!partial, !!init);
+
+ this.references.push(ref);
+ this.__left.push(ref);
+ }
+
+ __detectEval() {
+ let current = this;
+
+ this.directCallToEvalScope = true;
+ do {
+ current.dynamic = true;
+ current = current.upper;
+ } while (current);
+ }
+
+ __detectThis() {
+ this.thisFound = true;
+ }
+
+ __isClosed() {
+ return this.__left === null;
+ }
+
+ /**
+ * returns resolved {Reference}
+ * @method Scope#resolve
+ * @param {Espree.Identifier} ident - identifier to be resolved.
+ * @returns {Reference} reference
+ */
+ resolve(ident) {
+ let ref, i, iz;
+
+ assert(this.__isClosed(), "Scope should be closed.");
+ assert(ident.type === Syntax.Identifier, "Target should be identifier.");
+ for (i = 0, iz = this.references.length; i < iz; ++i) {
+ ref = this.references[i];
+ if (ref.identifier === ident) {
+ return ref;
+ }
+ }
+ return null;
+ }
+
+ /**
+ * returns this scope is static
+ * @method Scope#isStatic
+ * @returns {boolean} static
+ */
+ isStatic() {
+ return !this.dynamic;
+ }
+
+ /**
+ * returns this scope has materialized arguments
+ * @method Scope#isArgumentsMaterialized
+ * @returns {boolean} arguemnts materialized
+ */
+ isArgumentsMaterialized() { // eslint-disable-line class-methods-use-this
+ return true;
+ }
+
+ /**
+ * returns this scope has materialized `this` reference
+ * @method Scope#isThisMaterialized
+ * @returns {boolean} this materialized
+ */
+ isThisMaterialized() { // eslint-disable-line class-methods-use-this
+ return true;
+ }
+
+ isUsedName(name) {
+ if (this.set.has(name)) {
+ return true;
+ }
+ for (let i = 0, iz = this.through.length; i < iz; ++i) {
+ if (this.through[i].identifier.name === name) {
+ return true;
+ }
+ }
+ return false;
+ }
+}
+
+class GlobalScope extends Scope {
+ constructor(scopeManager, block) {
+ super(scopeManager, "global", null, block, false);
+ this.implicit = {
+ set: new Map(),
+ variables: [],
+
+ /**
+ * List of {@link Reference}s that are left to be resolved (i.e. which
+ * need to be linked to the variable they refer to).
+ * @member {Reference[]} Scope#implicit#left
+ */
+ left: []
+ };
+ }
+
+ __close(scopeManager) {
+ const implicit = [];
+
+ for (let i = 0, iz = this.__left.length; i < iz; ++i) {
+ const ref = this.__left[i];
+
+ if (ref.__maybeImplicitGlobal && !this.set.has(ref.identifier.name)) {
+ implicit.push(ref.__maybeImplicitGlobal);
+ }
+ }
+
+ // create an implicit global variable from assignment expression
+ for (let i = 0, iz = implicit.length; i < iz; ++i) {
+ const info = implicit[i];
+
+ this.__defineImplicit(info.pattern,
+ new Definition(
+ Variable.ImplicitGlobalVariable,
+ info.pattern,
+ info.node,
+ null,
+ null,
+ null
+ ));
+
+ }
+
+ this.implicit.left = this.__left;
+
+ return super.__close(scopeManager);
+ }
+
+ __defineImplicit(node, def) {
+ if (node && node.type === Syntax.Identifier) {
+ this.__defineGeneric(
+ node.name,
+ this.implicit.set,
+ this.implicit.variables,
+ node,
+ def
+ );
+ }
+ }
+}
+
+class ModuleScope extends Scope {
+ constructor(scopeManager, upperScope, block) {
+ super(scopeManager, "module", upperScope, block, false);
+ }
+}
+
+class FunctionExpressionNameScope extends Scope {
+ constructor(scopeManager, upperScope, block) {
+ super(scopeManager, "function-expression-name", upperScope, block, false);
+ this.__define(block.id,
+ new Definition(
+ Variable.FunctionName,
+ block.id,
+ block,
+ null,
+ null,
+ null
+ ));
+ this.functionExpressionScope = true;
+ }
+}
+
+class CatchScope extends Scope {
+ constructor(scopeManager, upperScope, block) {
+ super(scopeManager, "catch", upperScope, block, false);
+ }
+}
+
+class WithScope extends Scope {
+ constructor(scopeManager, upperScope, block) {
+ super(scopeManager, "with", upperScope, block, false);
+ }
+
+ __close(scopeManager) {
+ if (this.__shouldStaticallyClose(scopeManager)) {
+ return super.__close(scopeManager);
+ }
+
+ for (let i = 0, iz = this.__left.length; i < iz; ++i) {
+ const ref = this.__left[i];
+
+ ref.tainted = true;
+ this.__delegateToUpperScope(ref);
+ }
+ this.__left = null;
+
+ return this.upper;
+ }
+}
+
+class BlockScope extends Scope {
+ constructor(scopeManager, upperScope, block) {
+ super(scopeManager, "block", upperScope, block, false);
+ }
+}
+
+class SwitchScope extends Scope {
+ constructor(scopeManager, upperScope, block) {
+ super(scopeManager, "switch", upperScope, block, false);
+ }
+}
+
+class FunctionScope extends Scope {
+ constructor(scopeManager, upperScope, block, isMethodDefinition) {
+ super(scopeManager, "function", upperScope, block, isMethodDefinition);
+
+ // section 9.2.13, FunctionDeclarationInstantiation.
+ // NOTE Arrow functions never have an arguments objects.
+ if (this.block.type !== Syntax.ArrowFunctionExpression) {
+ this.__defineArguments();
+ }
+ }
+
+ isArgumentsMaterialized() {
+
+ // TODO(Constellation)
+ // We can more aggressive on this condition like this.
+ //
+ // function t() {
+ // // arguments of t is always hidden.
+ // function arguments() {
+ // }
+ // }
+ if (this.block.type === Syntax.ArrowFunctionExpression) {
+ return false;
+ }
+
+ if (!this.isStatic()) {
+ return true;
+ }
+
+ const variable = this.set.get("arguments");
+
+ assert(variable, "Always have arguments variable.");
+ return variable.tainted || variable.references.length !== 0;
+ }
+
+ isThisMaterialized() {
+ if (!this.isStatic()) {
+ return true;
+ }
+ return this.thisFound;
+ }
+
+ __defineArguments() {
+ this.__defineGeneric(
+ "arguments",
+ this.set,
+ this.variables,
+ null,
+ null
+ );
+ this.taints.set("arguments", true);
+ }
+
+ // References in default parameters isn't resolved to variables which are in their function body.
+ // const x = 1
+ // function f(a = x) { // This `x` is resolved to the `x` in the outer scope.
+ // const x = 2
+ // console.log(a)
+ // }
+ __isValidResolution(ref, variable) {
+
+ // If `options.nodejsScope` is true, `this.block` becomes a Program node.
+ if (this.block.type === "Program") {
+ return true;
+ }
+
+ const bodyStart = this.block.body.range[0];
+
+ // It's invalid resolution in the following case:
+ return !(
+ variable.scope === this &&
+ ref.identifier.range[0] < bodyStart && // the reference is in the parameter part.
+ variable.defs.every(d => d.name.range[0] >= bodyStart) // the variable is in the body.
+ );
+ }
+}
+
+class ForScope extends Scope {
+ constructor(scopeManager, upperScope, block) {
+ super(scopeManager, "for", upperScope, block, false);
+ }
+}
+
+class ClassScope extends Scope {
+ constructor(scopeManager, upperScope, block) {
+ super(scopeManager, "class", upperScope, block, false);
+ }
+}
+
+module.exports = {
+ Scope,
+ GlobalScope,
+ ModuleScope,
+ FunctionExpressionNameScope,
+ CatchScope,
+ WithScope,
+ BlockScope,
+ SwitchScope,
+ FunctionScope,
+ ForScope,
+ ClassScope
+};
+
+/* vim: set sw=4 ts=4 et tw=80 : */
projects / dotfiles / .git / blobdiff