diff -r 000000000000 -r 6474c204b198 js/src/devtools/rootAnalysis/utility.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/devtools/rootAnalysis/utility.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,143 @@
+/* -*- Mode: Javascript; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+"use strict";
+
+function assert(x, msg)
+{
+    if (x)
+        return;
+    debugger;
+    if (msg)
+        throw "assertion failed: " + msg + "\n" + (Error().stack);
+    else
+        throw "assertion failed: " + (Error().stack);
+}
+
+function defined(x) {
+    return x !== undefined;
+}
+
+function xprint(x, padding)
+{
+    if (!padding)
+        padding = "";
+    if (x instanceof Array) {
+        print(padding + "[");
+        for (var elem of x)
+            xprint(elem, padding + " ");
+        print(padding + "]");
+    } else if (x instanceof Object) {
+        print(padding + "{");
+        for (var prop in x) {
+            print(padding + " " + prop + ":");
+            xprint(x[prop], padding + "  ");
+        }
+        print(padding + "}");
+    } else {
+        print(padding + x);
+    }
+}
+
+function sameBlockId(id0, id1)
+{
+    if (id0.Kind != id1.Kind)
+        return false;
+    if (!sameVariable(id0.Variable, id1.Variable))
+        return false;
+    if (id0.Kind == "Loop" && id0.Loop != id1.Loop)
+        return false;
+    return true;
+}
+
+function sameVariable(var0, var1)
+{
+    assert("Name" in var0 || var0.Kind == "This" || var0.Kind == "Return");
+    assert("Name" in var1 || var1.Kind == "This" || var1.Kind == "Return");
+    if ("Name" in var0)
+        return "Name" in var1 && var0.Name[0] == var1.Name[0];
+    return var0.Kind == var1.Kind;
+}
+
+function blockIdentifier(body)
+{
+    if (body.BlockId.Kind == "Loop")
+        return body.BlockId.Loop;
+    assert(body.BlockId.Kind == "Function", "body.Kind should be Function, not " + body.BlockId.Kind);
+    return body.BlockId.Variable.Name[0];
+}
+
+function collectBodyEdges(body)
+{
+    body.predecessors = [];
+    body.successors = [];
+    if (!("PEdge" in body))
+        return;
+
+    for (var edge of body.PEdge) {
+        var [ source, target ] = edge.Index;
+        if (!(target in body.predecessors))
+            body.predecessors[target] = [];
+        body.predecessors[target].push(edge);
+        if (!(source in body.successors))
+            body.successors[source] = [];
+        body.successors[source].push(edge);
+    }
+}
+
+function getPredecessors(body)
+{
+    try {
+        if (!('predecessors' in body))
+            collectBodyEdges(body);
+    } catch (e) {
+        debugger;
+        printErr("body is " + body);
+    }
+    return body.predecessors;
+}
+
+function getSuccessors(body)
+{
+    if (!('successors' in body))
+        collectBodyEdges(body);
+    return body.successors;
+}
+
+// Split apart a function from sixgill into its mangled and unmangled name. If
+// no mangled name was given, use the unmangled name as its mangled name
+function splitFunction(func)
+{
+    var split = func.indexOf("|");
+    if (split == -1)
+        return [ func, func ];
+    return [ func.substr(0, split), func.substr(split+1) ];
+}
+
+function mangled(fullname)
+{
+    var split = fullname.indexOf("|");
+    if (split == -1)
+        return fullname;
+    return fullname.substr(0, split);
+}
+
+function readable(fullname)
+{
+    var split = fullname.indexOf("|");
+    if (split == -1)
+        return fullname;
+    return fullname.substr(split+1);
+}
+
+function xdbLibrary()
+{
+    var lib = ctypes.open(environment['XDB']);
+    return {
+        open: lib.declare("xdb_open", ctypes.default_abi, ctypes.void_t, ctypes.char.ptr),
+        min_data_stream: lib.declare("xdb_min_data_stream", ctypes.default_abi, ctypes.int),
+        max_data_stream: lib.declare("xdb_max_data_stream", ctypes.default_abi, ctypes.int),
+        read_key: lib.declare("xdb_read_key", ctypes.default_abi, ctypes.char.ptr, ctypes.int),
+        read_entry: lib.declare("xdb_read_entry", ctypes.default_abi, ctypes.char.ptr, ctypes.char.ptr),
+        free_string: lib.declare("xdb_free", ctypes.default_abi, ctypes.void_t, ctypes.char.ptr)
+    };
+}