[INFER] Always add type for 'arguments' variables, even with local redefinitions, bug 621126.

js/src/jit-test/tests/basic/builtinLocals.js

@@ -0,0 +1,35 @@
+
+/* Resolve 'arguments' and the name of the function itself in the presence of such local variables. */
+
+function f() {
+    return typeof arguments;
+    function arguments() {
+        return 7;
+    }
+}
+assertEq(f(), "object");
+
+function g() {
+    var arguments = 0;
+    return typeof arguments;
+}
+assertEq(g(), "number");
+
+function h() {
+    return typeof h;
+    function h() {
+        return 7;
+    }
+}
+assertEq(h(), "function");
+
+function i() {
+    return typeof i;
+    var i;
+}
+assertEq(i(), "undefined");
+
+function j() {
+    return typeof j;
+}
+assertEq(j(), "function");

js/src/jsinfer.cpp

@@ -1872,9 +1872,17 @@ Script::addVariable(JSContext *cx, jsid id, types::Variable *&var, bool localNam
     JS_ASSERT(!var);
     var = ArenaNew<types::Variable>(pool, &pool, id);
 
-    /* Variables which are definitely arguments or locals do not pull in builtin types. */
-    if (!localName) {
-        /* Augment with types for the 'arguments' variable. */
+    /*
+     * Augment with types for the function itself, unless this is an argument or
+     * local variable of the function.
+     */
+    if (!localName && fun && id == ATOM_TO_JSID(fun->atom))
+        var->types.addType(cx, (jstype) function());
+
+    /*
+     * Augment with types for the 'arguments' variable, even if there is a local
+     * variable named 'arguments'
+     */
     if (fun && id == id_arguments(cx)) {
         if (script->compileAndGo)
             var->types.addType(cx, (jstype) getTypeNewObject(cx, JSProto_Object));
@@ -1882,11 +1890,6 @@ Script::addVariable(JSContext *cx, jsid id, types::Variable *&var, bool localNam
             var->types.addType(cx, TYPE_UNKNOWN);
     }
 
-        /* Augment with types for the function itself. */
-        if (fun && id == ATOM_TO_JSID(fun->atom))
-            var->types.addType(cx, (jstype) function());
-    }
-
     InferSpew(ISpewOps, "addVariable: #%lu %s T%u",
               this->id, TypeIdString(id), var->types.id());
 }