Don't complain about reserved words in property name position

Also add forbidReserved: "everywhere" support. Issue #85
2014-02-14 11:27:48 +01:00 · 2014-02-14 11:27:48 +01:00 · 5bd50cce6f
commit 5bd50cce6f
parent 716ade22fb
4 changed files with 74 additions and 19 deletions
--- a/README.md
+++ b/README.md
@ -57,7 +57,9 @@ object referring to that same position.
  trailing commas in array and object literals. Default is `true`.

 - **forbidReserved**: If `true`, using a reserved word will generate
-  an error. Defaults to `false`.
+  an error. Defaults to `false`. When given the value `"everywhere"`,
+  reserved words and keywords can also not be used as property names
+  (as in Internet Explorer's old parser).
  
 - **allowReturnOutsideFunction**: By default, a return statement at
  the top level raises an error. Set this to `true` to accept such
--- a/acorn.js
+++ b/acorn.js
@ -62,7 +62,9 @@
    // trailing commas in array and object literals.
    allowTrailingCommas: true,
    // By default, reserved words are not enforced. Enable
-    // `forbidReserved` to enforce them.
+    // `forbidReserved` to enforce them. When this option has the
+    // value "everywhere", reserved words and keywords can also not be
+    // used as property names.
    forbidReserved: false,
    // When enabled, a return at the top level is not considered an
    // error.
@ -941,13 +943,8 @@
  function readWord() {
    var word = readWord1();
    var type = _name;
-    if (!containsEsc) {
-      if (isKeyword(word)) type = keywordTypes[word];
-      else if (options.forbidReserved &&
-               (options.ecmaVersion === 3 ? isReservedWord3 : isReservedWord5)(word) ||
-               strict && isStrictReservedWord(word))
-        raise(tokStart, "The keyword '" + word + "' is reserved");
-    }
+    if (!containsEsc && isKeyword(word))
+      type = keywordTypes[word];
    return finishToken(type, word);
  }

@ -1763,7 +1760,20 @@

  function parseIdent(liberal) {
    var node = startNode();
-    node.name = tokType === _name ? tokVal : (liberal && !options.forbidReserved && tokType.keyword) || unexpected();
+    if (liberal && options.forbidReserved == "everywhere") liberal = false;
+    if (tokType === _name) {
+      if (!liberal &&
+          (options.forbidReserved &&
+           (options.ecmaVersion === 3 ? isReservedWord3 : isReservedWord5)(tokVal) ||
+           strict && isStrictReservedWord(tokVal)) &&
+          input.slice(tokStart, tokEnd).indexOf("\\") == -1)
+        raise(tokStart, "The keyword '" + tokVal + "' is reserved");
+      node.name = tokVal;
+    } else if (liberal && tokType.keyword) {
+      node.name = tokType.keyword;
+    } else {
+      unexpected();
+    }
    tokRegexpAllowed = false;
    next();
    return finishNode(node, "Identifier");
--- a/index.html
+++ b/index.html
@ -39,7 +39,9 @@ influences support for strict mode, the set of reserved words, and
 support for getters and setter.</p>             </td>             <td class="code">               <div class="highlight"><pre>    <span class="nx">ecmaVersion</span><span class="o">:</span> <span class="mi">5</span><span class="p">,</span></pre></div>             </td>           </tr>                               <tr id="section-5">             <td class="docs">               <div class="pilwrap">                 <a class="pilcrow" href="#section-5">&#182;</a>               </div>               <p>Turn on <code>strictSemicolons</code> to prevent the parser from doing
 automatic semicolon insertion.</p>             </td>             <td class="code">               <div class="highlight"><pre>    <span class="nx">strictSemicolons</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span></pre></div>             </td>           </tr>                               <tr id="section-6">             <td class="docs">               <div class="pilwrap">                 <a class="pilcrow" href="#section-6">&#182;</a>               </div>               <p>When <code>allowTrailingCommas</code> is false, the parser will not allow
 trailing commas in array and object literals.</p>             </td>             <td class="code">               <div class="highlight"><pre>    <span class="nx">allowTrailingCommas</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span></pre></div>             </td>           </tr>                               <tr id="section-7">             <td class="docs">               <div class="pilwrap">                 <a class="pilcrow" href="#section-7">&#182;</a>               </div>               <p>By default, reserved words are not enforced. Enable
-<code>forbidReserved</code> to enforce them.</p>             </td>             <td class="code">               <div class="highlight"><pre>    <span class="nx">forbidReserved</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span></pre></div>             </td>           </tr>                               <tr id="section-8">             <td class="docs">               <div class="pilwrap">                 <a class="pilcrow" href="#section-8">&#182;</a>               </div>               <p>When enabled, a return at the top level is not considered an
+<code>forbidReserved</code> to enforce them. When this option has the
+value "everywhere", reserved words and keywords can also not be
+used as property names.</p>             </td>             <td class="code">               <div class="highlight"><pre>    <span class="nx">forbidReserved</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span></pre></div>             </td>           </tr>                               <tr id="section-8">             <td class="docs">               <div class="pilwrap">                 <a class="pilcrow" href="#section-8">&#182;</a>               </div>               <p>When enabled, a return at the top level is not considered an
 error.</p>             </td>             <td class="code">               <div class="highlight"><pre>    <span class="nx">allowReturnOutsideFunction</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span></pre></div>             </td>           </tr>                               <tr id="section-9">             <td class="docs">               <div class="pilwrap">                 <a class="pilcrow" href="#section-9">&#182;</a>               </div>               <p>When <code>locations</code> is on, <code>loc</code> properties holding objects with
 <code>start</code> and <code>end</code> properties in <code>{line, column}</code> form (with
 line being 1-based and column 0-based) will be attached to the
@ -676,13 +678,8 @@ containeds an escape, as a micro-optimization.</p>             </td>
 words when necessary.</p>             </td>             <td class="code">               <div class="highlight"><pre>  <span class="kd">function</span> <span class="nx">readWord</span><span class="p">()</span> <span class="p">{</span>
    <span class="kd">var</span> <span class="nx">word</span> <span class="o">=</span> <span class="nx">readWord1</span><span class="p">();</span>
    <span class="kd">var</span> <span class="nx">type</span> <span class="o">=</span> <span class="nx">_name</span><span class="p">;</span>
-    <span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">containsEsc</span><span class="p">)</span> <span class="p">{</span>
-      <span class="k">if</span> <span class="p">(</span><span class="nx">isKeyword</span><span class="p">(</span><span class="nx">word</span><span class="p">))</span> <span class="nx">type</span> <span class="o">=</span> <span class="nx">keywordTypes</span><span class="p">[</span><span class="nx">word</span><span class="p">];</span>
-      <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">forbidReserved</span> <span class="o">&amp;&amp;</span>
-               <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">ecmaVersion</span> <span class="o">===</span> <span class="mi">3</span> <span class="o">?</span> <span class="nx">isReservedWord3</span> <span class="o">:</span> <span class="nx">isReservedWord5</span><span class="p">)(</span><span class="nx">word</span><span class="p">)</span> <span class="o">||</span>
-               <span class="nx">strict</span> <span class="o">&amp;&amp;</span> <span class="nx">isStrictReservedWord</span><span class="p">(</span><span class="nx">word</span><span class="p">))</span>
-        <span class="nx">raise</span><span class="p">(</span><span class="nx">tokStart</span><span class="p">,</span> <span class="s2">&quot;The keyword &#39;&quot;</span> <span class="o">+</span> <span class="nx">word</span> <span class="o">+</span> <span class="s2">&quot;&#39; is reserved&quot;</span><span class="p">);</span>
-    <span class="p">}</span>
+    <span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">containsEsc</span> <span class="o">&amp;&amp;</span> <span class="nx">isKeyword</span><span class="p">(</span><span class="nx">word</span><span class="p">))</span>
+      <span class="nx">type</span> <span class="o">=</span> <span class="nx">keywordTypes</span><span class="p">[</span><span class="nx">word</span><span class="p">];</span>
    <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">type</span><span class="p">,</span> <span class="nx">word</span><span class="p">);</span>
  <span class="p">}</span></pre></div>             </td>           </tr>                               <tr id="section-79">             <td class="docs">               <div class="pilwrap">                 <a class="pilcrow" href="#section-79">&#182;</a>               </div>               <h2>Parser</h2>             </td>             <td class="code">               <div class="highlight"><pre></pre></div>             </td>           </tr>                               <tr id="section-80">             <td class="docs">               <div class="pilwrap">                 <a class="pilcrow" href="#section-80">&#182;</a>               </div>               <p>A recursive descent parser operates by defining functions for all
 syntactic elements, and recursively calling those, each function
@ -1323,7 +1320,20 @@ for array literals).</p>             </td>             <td class="code">
 when parsing properties), it will also convert keywords into
 identifiers.</p>             </td>             <td class="code">               <div class="highlight"><pre>  <span class="kd">function</span> <span class="nx">parseIdent</span><span class="p">(</span><span class="nx">liberal</span><span class="p">)</span> <span class="p">{</span>
    <span class="kd">var</span> <span class="nx">node</span> <span class="o">=</span> <span class="nx">startNode</span><span class="p">();</span>
-    <span class="nx">node</span><span class="p">.</span><span class="nx">name</span> <span class="o">=</span> <span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_name</span> <span class="o">?</span> <span class="nx">tokVal</span> <span class="o">:</span> <span class="p">(</span><span class="nx">liberal</span> <span class="o">&amp;&amp;</span> <span class="o">!</span><span class="nx">options</span><span class="p">.</span><span class="nx">forbidReserved</span> <span class="o">&amp;&amp;</span> <span class="nx">tokType</span><span class="p">.</span><span class="nx">keyword</span><span class="p">)</span> <span class="o">||</span> <span class="nx">unexpected</span><span class="p">();</span>
+    <span class="k">if</span> <span class="p">(</span><span class="nx">liberal</span> <span class="o">&amp;&amp;</span> <span class="nx">options</span><span class="p">.</span><span class="nx">forbidReserved</span> <span class="o">==</span> <span class="s2">&quot;everywhere&quot;</span><span class="p">)</span> <span class="nx">liberal</span> <span class="o">=</span> <span class="kc">false</span><span class="p">;</span>
+    <span class="k">if</span> <span class="p">(</span><span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_name</span><span class="p">)</span> <span class="p">{</span>
+      <span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">liberal</span> <span class="o">&amp;&amp;</span>
+          <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">forbidReserved</span> <span class="o">&amp;&amp;</span>
+           <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">ecmaVersion</span> <span class="o">===</span> <span class="mi">3</span> <span class="o">?</span> <span class="nx">isReservedWord3</span> <span class="o">:</span> <span class="nx">isReservedWord5</span><span class="p">)(</span><span class="nx">tokVal</span><span class="p">)</span> <span class="o">||</span>
+           <span class="nx">strict</span> <span class="o">&amp;&amp;</span> <span class="nx">isStrictReservedWord</span><span class="p">(</span><span class="nx">tokVal</span><span class="p">))</span> <span class="o">&amp;&amp;</span>
+          <span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">tokStart</span><span class="p">,</span> <span class="nx">tokEnd</span><span class="p">).</span><span class="nx">indexOf</span><span class="p">(</span><span class="s2">&quot;\\&quot;</span><span class="p">)</span> <span class="o">==</span> <span class="o">-</span><span class="mi">1</span><span class="p">)</span>
+        <span class="nx">raise</span><span class="p">(</span><span class="nx">tokStart</span><span class="p">,</span> <span class="s2">&quot;The keyword &#39;&quot;</span> <span class="o">+</span> <span class="nx">tokVal</span> <span class="o">+</span> <span class="s2">&quot;&#39; is reserved&quot;</span><span class="p">);</span>
+      <span class="nx">node</span><span class="p">.</span><span class="nx">name</span> <span class="o">=</span> <span class="nx">tokVal</span><span class="p">;</span>
+    <span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">liberal</span> <span class="o">&amp;&amp;</span> <span class="nx">tokType</span><span class="p">.</span><span class="nx">keyword</span><span class="p">)</span> <span class="p">{</span>
+      <span class="nx">node</span><span class="p">.</span><span class="nx">name</span> <span class="o">=</span> <span class="nx">tokType</span><span class="p">.</span><span class="nx">keyword</span><span class="p">;</span>
+    <span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
+      <span class="nx">unexpected</span><span class="p">();</span>
+    <span class="p">}</span>
    <span class="nx">tokRegexpAllowed</span> <span class="o">=</span> <span class="kc">false</span><span class="p">;</span>
    <span class="nx">next</span><span class="p">();</span>
    <span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">&quot;Identifier&quot;</span><span class="p">);</span>
--- a/test/tests.js
+++ b/test/tests.js
@ -26348,6 +26348,39 @@ test("x = y-->10;\n --> nothing", {
  ]
 });

+test("'use strict';\nobject.static();", {
+  type: "Program",
+  body: [
+    {
+      type: "ExpressionStatement",
+      expression: {
+        type: "Literal",
+        value: "use strict",
+        raw: "'use strict'"
+      }
+    },
+    {
+      type: "ExpressionStatement",
+      expression: {
+        type: "CallExpression",
+        callee: {
+          type: "MemberExpression",
+          object: {
+            type: "Identifier",
+            name: "object"
+          },
+          property: {
+            type: "Identifier",
+            name: "static"
+          },
+          computed: false
+        },
+        arguments: []
+      }
+    }
+  ]
+});
+
 // Failure tests

 testFail("{",