From b0412a6ae888d17cfec929ca1dccefd3e80b263f Mon Sep 17 00:00:00 2001
From: Pavol Bielik <pbielik@acm.org>
Date: Sun, 25 Jan 2015 00:11:19 +0100
Subject: [PATCH] Add generating scope constraints

---
 bin/js_features.js                |  9 +++--
 lib/feature_extractor.js          | 65 +++++++++++++++++++++++++++++++
 test/feature_extraction/fnames.js | 37 +++++++++++++++++-
 3 files changed, 106 insertions(+), 5 deletions(-)

diff --git a/bin/js_features.js b/bin/js_features.js
index 50fcbbeb..2b361bd9 100755
--- a/bin/js_features.js
+++ b/bin/js_features.js
@@ -15,9 +15,10 @@ var ARGS = yargs
 	.describe("skip_minified", "Whether to skip processing minified files")
 	.describe("features", "Comma separated list of features: \n" + 
          "ASTREL - relations in AST, \n" + 
-         "FNAMES - function names to internal calls")
+         "FNAMES - function names to internal calls,\n" +
+		 "FSCOPE - add variable scope constraints.")
 	.demand(1)
-	.default('features', 'ASTREL,FNAMES')	
+	.default('features', 'ASTREL,FNAMES,FSCOPE')
 	.boolean("print_ast")
 	.boolean("skip_minified")
 	.boolean("json_formatting")
@@ -45,8 +46,8 @@ if (ARGS.features === true) {
 
 var features = ARGS.features.split(",");
 for (var i = 0; i < features.length; i++) {
-	if (features[i] != "FNAMES" && features[i] != "ASTREL") {
-		sys.error("WARNING: ignoring not suppored feature '" + features[i] + "'.");
+	if (features[i] != "FNAMES" && features[i] != "ASTREL" && features[i] != "FSCOPE") {
+		sys.error("WARNING: ignoring not supported feature '" + features[i] + "'.");
 	};
 };
 
diff --git a/lib/feature_extractor.js b/lib/feature_extractor.js
index cea2db00..c4bef4f5 100644
--- a/lib/feature_extractor.js
+++ b/lib/feature_extractor.js
@@ -89,6 +89,10 @@ function extractFeatures(code, file, print_ast, features, skip_minified) {
 		generateFnamesFeatures(toplevel, feature_outputter);
 	}
 
+	if (features.indexOf("FSCOPE") != -1) {
+		generateFscopeConstraints(toplevel, feature_outputter);
+	}
+
 	feature_outputter.closeArray();
 	feature_outputter.dumpSymbols();
 	feature_outputter.closeElem();
@@ -247,6 +251,37 @@ function addFeatures(lhss, lhs_label, rhs, rhs_label, feature_outputter){
 	}
 }
 
+function addScopeConstraints(node, toplevel, feature_outputter){
+	feature_outputter.beginScope();
+	var name = nodeToString(node);
+	if (name != null)
+		feature_outputter.addToScope(name);
+
+	for (var i = 0; i < node.enclosed.length; i++){
+		feature_outputter.addToScope(nodeToString(node.enclosed[i].orig[0]));
+	}
+
+	node.variables.each(function(symbol){
+		feature_outputter.addToScope(nodeToString(symbol.orig[0]));
+	});
+
+	toplevel.globals.each(function(symbol){
+		feature_outputter.addToScope(nodeToString(symbol.orig[0]));
+	});
+
+	feature_outputter.endScope();
+}
+
+
+function generateFscopeConstraints(toplevel, feature_outputter){
+	addScopeConstraints(toplevel, toplevel, feature_outputter);
+	toplevel.walk(new TreeWalker(function(node) {
+		if (node instanceof AST_Defun || node instanceof AST_Lambda) {
+			addScopeConstraints(node, toplevel, feature_outputter);
+		}
+	}));
+}
+
 function generateFnamesFeatures(toplevel, feature_outputter){
 	var outer_funcs = [];
 
@@ -321,6 +356,7 @@ function FeatureJsonOutputter() {
 	this.output = "";
 	this.depth = 0;
 	this.pairs = {};
+	this.cur_scope = {};
 }
 
 FeatureJsonOutputter.prototype.indent = function() {
@@ -428,6 +464,35 @@ FeatureJsonOutputter.prototype.dumpSymbols = function(){
 	this.closeArray();
 };
 
+FeatureJsonOutputter.prototype.beginScope = function(){
+	this.cur_scope = {};
+};
+
+FeatureJsonOutputter.prototype.addToScope = function(a){
+	var a_id = this.string_map.getId(a);
+	this.cur_scope[a_id] = true;
+};
+
+FeatureJsonOutputter.prototype.endScope = function(){
+	//{"cn":"!=","n":[14,366,370,372,108,40,356]}
+	var keys = Object.keys(this.cur_scope);
+	if (keys.length <= 1) {
+		return;
+	}
+
+	this.openElem();
+	this.output += '"cn":"!=", "n":[';
+
+	this.output += keys[0];
+	for(var i = 1,length = keys.length; i < length; i++ ) {
+		this.output += ',';
+		this.output += keys[i];
+	}
+
+	this.output += "]";
+	this.closeElem();
+};
+
 /* -----[ StringMap ]----- */
 
 function StringMap(nice_names) {
diff --git a/test/feature_extraction/fnames.js b/test/feature_extraction/fnames.js
index fc7b9be1..40f5dbc3 100644
--- a/test/feature_extraction/fnames.js
+++ b/test/feature_extraction/fnames.js
@@ -243,4 +243,39 @@ func_return: {
 			]
 		}'
 	}
-}
\ No newline at end of file
+}
+
+func_scopes: {
+	options = {
+		features	: "FNAMES, FSCOPE"
+	};
+	input: {
+		function foo(x,b){
+			var a = x + y + 1;
+			(function(r) {
+				return r + x;
+			})(2);
+		}
+	}
+	expect: {
+		'{
+			"query":[
+			{"a": 0,	"b": 1,	"f2": "FNPAR"},
+			{"a": 0,	"b": 2,	"f2": "FNPAR"},
+			{"a": 0,	"b": 3,	"f2": "FNDECL"},
+			{"cn":"!=", "n":[0,4]},
+			{"cn":"!=", "n":[0,1,2,3,4]},
+			{"cn":"!=", "n":[1,4,5]}
+			],
+			"assign":[
+			{"v": 0,	"giv": "foo"},
+			{"v": 1,	"inf": "x"},
+			{"v": 2,	"inf": "b"},
+			{"v": 3,	"inf": "a"},
+			{"v": 4,	"giv": "y"},
+			{"v": 5,	"inf": "r"}
+			]
+		}'
+	}
+}
+