1 | "use strict";
|
2 |
|
3 | const assert = require("assert");
|
4 | const stringmap = require("stringmap");
|
5 | const stringset = require("stringset");
|
6 | const is = require("simple-is");
|
7 | const fmt = require("simple-fmt");
|
8 | const error = require("./error");
|
9 | const options = require("./options");
|
10 |
|
11 | function Scope(args) {
|
12 | assert(is.someof(args.kind, ["hoist", "block", "catch-block"]));
|
13 | assert(is.object(args.node));
|
14 | assert(args.parent === null || is.object(args.parent));
|
15 |
|
16 | this.kind = args.kind;
|
17 | this.node = args.node;
|
18 | this.parent = args.parent;
|
19 | this.children = [];
|
20 | this.decls = stringmap();
|
21 | this.moves = stringmap();
|
22 | this.written = stringset();
|
23 | this.propagates = (this.kind === "hoist" ? stringset() : null);
|
24 |
|
25 | if (this.parent) {
|
26 | this.parent.children.push(this);
|
27 | }
|
28 | }
|
29 |
|
30 | Scope.prototype.print = function(indent) {
|
31 | indent = indent || 0;
|
32 | const scope = this;
|
33 | const names = this.decls.keys().map(function(name) {
|
34 | return fmt("{0} [{1}]", name, scope.decls.get(name).kind);
|
35 | }).join(", ");
|
36 | const propagates = this.propagates ? this.propagates.items().join(", ") : "";
|
37 | console.log(fmt("{0}{1}: {2}. propagates: {3}", fmt.repeat(" ", indent), this.node.type, names, propagates));
|
38 | this.children.forEach(function(c) {
|
39 | c.print(indent + 2);
|
40 | });
|
41 | };
|
42 |
|
43 | Scope.prototype.add = function(name, kind, node, referableFromPos) {
|
44 | assert(is.someof(kind, ["fun", "param", "var", "caught", "const", "let"]));
|
45 |
|
46 | function isConstLet(kind) {
|
47 | return is.someof(kind, ["const", "let"]);
|
48 | }
|
49 |
|
50 | let scope = this;
|
51 |
|
52 |
|
53 |
|
54 | if (is.someof(kind, ["fun", "param", "var"])) {
|
55 | while (scope.kind !== "hoist") {
|
56 | if (scope.decls.has(name) && isConstLet(scope.decls.get(name).kind)) {
|
57 | return error(node.loc.start.line, "{0} is already declared", name);
|
58 | }
|
59 | scope = scope.parent;
|
60 | }
|
61 | }
|
62 |
|
63 | if (scope.decls.has(name) && (options.disallowDuplicated || isConstLet(scope.decls.get(name).kind) || isConstLet(kind))) {
|
64 | return error(node.loc.start.line, "{0} is already declared", name);
|
65 | }
|
66 |
|
67 | if (kind === "fun" && referableFromPos === null) {
|
68 | referableFromPos = scope.node.range[0];
|
69 | }
|
70 |
|
71 | scope.decls.set(name, {
|
72 | kind: kind,
|
73 | node: node,
|
74 | from: referableFromPos,
|
75 | });
|
76 | };
|
77 |
|
78 | Scope.prototype.addGlobal = function(name, kind, node, referableFromPos) {
|
79 | assert(is.someof(kind, ["fun", "param", "var", "caught", "const", "let"]));
|
80 | assert(this.parent === null);
|
81 | this.decls.set(name, {
|
82 | kind: kind,
|
83 | node: node,
|
84 | from: referableFromPos,
|
85 | });
|
86 | };
|
87 |
|
88 | Scope.prototype.getKind = function(name) {
|
89 | assert(is.string(name));
|
90 | const decl = this.decls.get(name);
|
91 | return decl ? decl.kind : null;
|
92 | };
|
93 |
|
94 | Scope.prototype.getNode = function(name) {
|
95 | assert(is.string(name));
|
96 | const decl = this.decls.get(name);
|
97 | return decl ? decl.node : null;
|
98 | };
|
99 |
|
100 | Scope.prototype.getFromPos = function(name) {
|
101 | assert(is.string(name));
|
102 | const decl = this.decls.get(name);
|
103 | return decl ? decl.from : null;
|
104 | };
|
105 |
|
106 | Scope.prototype.move = function(name, newName, newScope) {
|
107 | assert(is.string(name));
|
108 | assert(is.string(newName));
|
109 | assert(this.decls.has(name));
|
110 | this.decls.delete(name);
|
111 | this.moves.set(name, {
|
112 | name: newName,
|
113 | scope: newScope,
|
114 | });
|
115 | };
|
116 |
|
117 | Scope.prototype.getMove = function(name) {
|
118 | return this.moves.get(name);
|
119 | };
|
120 |
|
121 | Scope.prototype.hasOwn = function(name) {
|
122 | return this.decls.has(name);
|
123 | };
|
124 |
|
125 | Scope.prototype.doesPropagate = function(name) {
|
126 | return this.propagates.has(name);
|
127 | };
|
128 |
|
129 | Scope.prototype.markPropagates = function(name) {
|
130 | this.propagates.add(name);
|
131 | };
|
132 |
|
133 | Scope.prototype.closestHoistScope = function() {
|
134 | let scope = this;
|
135 | while (scope.kind !== "hoist") {
|
136 | scope = scope.parent;
|
137 | }
|
138 | return scope;
|
139 | };
|
140 |
|
141 | Scope.prototype.hasFunctionScopeBetween = function(outer) {
|
142 | function isFunction(node) {
|
143 | return is.someof(node.type, ["FunctionDeclaration", "FunctionExpression"]);
|
144 | }
|
145 |
|
146 | for (let scope = this; scope; scope = scope.parent) {
|
147 | if (scope === outer) {
|
148 | return false;
|
149 | }
|
150 | if (isFunction(scope.node)) {
|
151 | return true;
|
152 | }
|
153 | }
|
154 |
|
155 | throw new Error("wasn't inner scope of outer");
|
156 | };
|
157 |
|
158 | Scope.prototype.lookup = function(name) {
|
159 | for (let scope = this; scope; scope = scope.parent) {
|
160 | if (scope.decls.has(name)) {
|
161 | return scope;
|
162 | } else if (scope.kind === "hoist") {
|
163 | scope.propagates.add(name);
|
164 | }
|
165 | }
|
166 | return null;
|
167 | };
|
168 |
|
169 | Scope.prototype.markWrite = function(name) {
|
170 | assert(is.string(name));
|
171 | this.written.add(name);
|
172 | };
|
173 |
|
174 |
|
175 | Scope.prototype.detectUnmodifiedLets = function() {
|
176 | const outmost = this;
|
177 |
|
178 | function detect(scope) {
|
179 | if (scope !== outmost) {
|
180 | scope.decls.keys().forEach(function(name) {
|
181 | if (scope.getKind(name) === "let" && !scope.written.has(name)) {
|
182 | return error(scope.getNode(name).loc.start.line, "{0} is declared as let but never modified so could be const", name);
|
183 | }
|
184 | });
|
185 | }
|
186 |
|
187 | scope.children.forEach(function(childScope) {
|
188 | detect(childScope);;
|
189 | });
|
190 | }
|
191 | detect(this);
|
192 | };
|
193 |
|
194 | module.exports = Scope;
|