From 1e3d236aed29b8d5d2d2aadc516b6e5a0a9c7ddc Mon Sep 17 00:00:00 2001
From: Pavol Bielik <pbielik@acm.org>
Date: Sun, 25 Jan 2015 01:50:10 +0100
Subject: [PATCH] do not output constrains if there are no features

---
 lib/feature_extractor.js | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/lib/feature_extractor.js b/lib/feature_extractor.js
index 0145413b..4b36bcd9 100644
--- a/lib/feature_extractor.js
+++ b/lib/feature_extractor.js
@@ -49,9 +49,10 @@ function replaceMangled(code, file) {
 	var feature_outputter = new FeatureJsonOutputter();
 	generateAstFeatures(toplevel, feature_outputter);
 	generateFnamesFeatures(toplevel, feature_outputter);
+	generateFscopeConstraints(toplevel, feature_outputter);
 
-	//feature_outputter.string_map defines what id is assigment to each node in the final output
-	//therefore to assign same ids, we need to first populate by running feature extraction
+	//feature_outputter.string_map defines what id is assigned to each node in the final output
+	//therefore to assign same ids, we need to first populate string_map by running feature extraction
 	var stream = OutputStream({beautify : true, replace_mangled_map : feature_outputter.string_map});
 	toplevel.print(stream);
 	return stream.toString();
@@ -361,6 +362,7 @@ function FeatureJsonOutputter() {
 	this.depth = 0;
 	this.pairs = {};
 	this.cur_scope = {};
+	this.has_features = false;
 }
 
 FeatureJsonOutputter.prototype.indent = function() {
@@ -432,6 +434,8 @@ FeatureJsonOutputter.prototype.addFeature = function(a, b, name){
 		return;
 	}
 
+	this.has_features = true;
+
 	this.openElem();
 
 	this.output += '"a": ' + a_id + ",";
@@ -457,6 +461,12 @@ FeatureJsonOutputter.prototype.addSymbol = function(key){
 };
 
 FeatureJsonOutputter.prototype.dumpSymbols = function(){
+	if (!this.has_features) {
+		this.openArray("assign");
+		this.closeArray();
+		return;
+	}
+
 	this.openArray("assign");
 
 	// var keys = Object.keys( this.string_map.map );
@@ -479,6 +489,10 @@ FeatureJsonOutputter.prototype.addToScope = function(a){
 
 FeatureJsonOutputter.prototype.endScope = function(){
 	//{"cn":"!=","n":[14,366,370,372,108,40,356]}
+	if (!this.has_features) {
+		return;
+	}
+
 	var keys = Object.keys(this.cur_scope);
 	if (keys.length <= 1) {
 		return;