Bug 573569: One-pass SSA builder for Narcissus. (r=gal)

js/narcissus/jsdefs.js

@@ -112,6 +112,9 @@ Narcissus.definitions = (function() {
         // Terminals.
         "IDENTIFIER", "NUMBER", "STRING", "REGEXP",
 
+        // SSA fiction.
+        "PHI", "INTERVENED",
+
         // Keywords.
         "break",
         "case", "catch", "const", "continue",

js/narcissus/jsexec.js

@@ -1,5 +1,5 @@
 /* -*- Mode: JS; tab-width: 4; indent-tabs-mode: nil; -*-
- * vim: set sw=4 ts=8 et tw=78:
+ * vim: set sw=4 ts=4 et tw=78:
 /* ***** BEGIN LICENSE BLOCK *****
  *
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
@@ -140,7 +140,7 @@ Narcissus.interpreter = (function() {
             return s;
         },
 
-        //Don't want to proxy RegExp or some features won't work
+        // Don't want to proxy RegExp or some features won't work
         RegExp: RegExp,
 
         // Extensions to ECMA.
@@ -307,6 +307,22 @@ Narcissus.interpreter = (function() {
                  : new TypeError(message);
     }
 
+    function valuatePhis(n, v) {
+        var ps = n.phiUses;
+        if (!ps)
+            return;
+
+        for (var i = 0, j = ps.length; i < j; i++) {
+            // If the thing we're valuating is already equal to the thing we want
+            // to valuate it to, we have fully saturated (and have a cycle), and
+            // thus we should break.
+            if (ps[i].v === v)
+                break;
+            ps[i].v = v;
+            valuatePhis(ps[i], v);
+        }
+    }
+
     function execute(n, x) {
         var a, f, i, j, r, s, t, u, v;
 
@@ -818,11 +834,22 @@ Narcissus.interpreter = (function() {
             break;
 
           case IDENTIFIER:
-            for (s = x.scope; s; s = s.parent) {
-                if (n.value in s.object)
-                    break;
+            // Identifiers with forward pointers that weren't intervened can't be
+            // lvalues, so we safely get the cached value directly.
+            var resolved = n.resolve();
+
+            if (n.forward && !resolved.intervened &&
+                !(resolved.type == FUNCTION &&
+                  resolved.functionForm == parser.DECLARED_FORM)) {
+                v = resolved.v;
+                break;
+            } else {
+                for (s = x.scope; s; s = s.parent) {
+                    if (n.value in s.object)
+                        break;
+                }
+                v = new Reference(s && s.object, n.value, n);
             }
-            v = new Reference(s && s.object, n.value, n);
             break;
 
           case NUMBER:
@@ -839,6 +866,11 @@ Narcissus.interpreter = (function() {
             throw "PANIC: unknown operation " + n.type + ": " + uneval(n);
         }
 
+        if (n.backwards) {
+            n.v = v;
+        }
+        valuatePhis(n, v);
+
         return v;
     }
 
@@ -864,6 +896,21 @@ Narcissus.interpreter = (function() {
         definitions.defineProperty(proto, "constructor", this, false, false, true);
     }
 
+    function getPropertyDescriptor(obj, name) {
+        while (obj) {
+            if (({}).hasOwnProperty.call(obj, name))
+                return Object.getOwnPropertyDescriptor(obj, name);
+            obj = Object.getPrototypeOf(obj);
+        }
+    }
+
+    function getOwnProperties(obj) {
+        var map = {};
+        for (var name in Object.getOwnPropertyNames(obj))
+            map[name] = Object.getOwnPropertyDescriptor(obj, name);
+        return map;
+    }
+
     // Returns a new function wrapped with a Proxy.
     function newFunction(n, x) {
         var fobj = new FunctionObject(n, x.scope);
@@ -1098,4 +1145,3 @@ Narcissus.interpreter = (function() {
     };
 
 }());
-

js/narcissus/jslex.js

@@ -94,8 +94,10 @@ Narcissus.lexer = (function() {
         },
 
         mustMatch: function (tt) {
-            if (!this.match(tt))
-                throw this.newSyntaxError("Missing " + tokens[tt].toLowerCase());
+            if (!this.match(tt)) {
+                throw this.newSyntaxError("Missing " +
+                                          definitions.tokens[tt].toLowerCase());
+            }
             return this.token;
         },
 
@@ -466,4 +468,3 @@ Narcissus.lexer = (function() {
     return { Tokenizer: Tokenizer };
 
 }());
-