diff --git a/externals/xhprof/xhprof_lib.php b/externals/xhprof/xhprof_lib.php
--- a/externals/xhprof/xhprof_lib.php
+++ b/externals/xhprof/xhprof_lib.php
@@ -19,8 +19,10 @@
 // Do not add any display specific code here.
 //
 
-function xhprof_error($message) {
-  error_log($message);
+if (!function_exists('xhprof_error')) {
+  function xhprof_error($message) {
+    error_log($message);
+  }
 }
 
 /*
@@ -31,8 +33,8 @@
  */
 function xhprof_get_possible_metrics() {
  static $possible_metrics =
-   array("wt" => array("Wall", "microsecs", "walltime" ),
-         "ut" => array("User", "microsecs", "user cpu time" ),
+   array("wt" => array("Wall", "microsecs", "walltime"),
+         "ut" => array("User", "microsecs", "user cpu time"),
          "st" => array("Sys", "microsecs", "system cpu time"),
          "cpu" => array("Cpu", "microsecs", "cpu time"),
          "mu" => array("MUse", "bytes", "memory usage"),
@@ -41,6 +43,82 @@
  return $possible_metrics;
 }
 
+/**
+ * Initialize the metrics we'll display based on the information
+ * in the raw data.
+ *
+ * @author Kannan
+ */
+function init_metrics($xhprof_data, $rep_symbol, $sort, $diff_report = false) {
+  global $stats;
+  global $pc_stats;
+  global $metrics;
+  global $diff_mode;
+  global $sortable_columns;
+  global $sort_col;
+  global $display_calls;
+
+  $diff_mode = $diff_report;
+
+  if (!empty($sort)) {
+    if (array_key_exists($sort, $sortable_columns)) {
+      $sort_col = $sort;
+    } else {
+      print("Invalid Sort Key $sort specified in URL");
+    }
+  }
+
+  // For C++ profiler runs, walltime attribute isn't present.
+  // In that case, use "samples" as the default sort column.
+  if (!isset($xhprof_data["main()"]["wt"])) {
+
+    if ($sort_col == "wt") {
+      $sort_col = "samples";
+    }
+
+    // C++ profiler data doesn't have call counts.
+    // ideally we should check to see if "ct" metric
+    // is present for "main()". But currently "ct"
+    // metric is artificially set to 1. So, relying
+    // on absence of "wt" metric instead.
+    $display_calls = false;
+  } else {
+    $display_calls = true;
+  }
+
+  // parent/child report doesn't support exclusive times yet.
+  // So, change sort hyperlinks to closest fit.
+  if (!empty($rep_symbol)) {
+    $sort_col = str_replace("excl_", "", $sort_col);
+  }
+
+  if ($display_calls) {
+    $stats = array("fn", "ct", "Calls%");
+  } else {
+    $stats = array("fn");
+  }
+
+  $pc_stats = $stats;
+
+  $possible_metrics = xhprof_get_possible_metrics();
+  foreach ($possible_metrics as $metric => $desc) {
+    if (isset($xhprof_data["main()"][$metric])) {
+      $metrics[] = $metric;
+      // flat (top-level reports): we can compute
+      // exclusive metrics reports as well.
+      $stats[] = $metric;
+      $stats[] = "I" . $desc[0] . "%";
+      $stats[] = "excl_" . $metric;
+      $stats[] = "E" . $desc[0] . "%";
+
+      // parent/child report for a function: we can
+      // only breakdown inclusive times correctly.
+      $pc_stats[] = $metric;
+      $pc_stats[] = "I" . $desc[0] . "%";
+    }
+  }
+}
+
 /*
  * Get the list of metrics present in $xhprof_data as an array.
  *
@@ -259,9 +337,9 @@
   }
 
   $bad_runs = array();
-  foreach($runs as $idx => $run_id) {
+  foreach ($runs as $idx => $run_id) {
 
-    $raw_data = $xhprof_runs_impl->get_run($run_id, $source, '?');
+    $raw_data = $xhprof_runs_impl->get_run($run_id, $source, $description);
 
     // use the first run to derive what metrics to aggregate on.
     if ($idx == 0) {
@@ -283,7 +361,7 @@
     }
 
     if ($use_script_name) {
-      $page = '?';
+      $page = $description;
 
       // create a fake function '__script::$page', and have and edge from
       // main() to '__script::$page'. We will also need edges to transfer
@@ -294,7 +372,7 @@
       // it shows up above the new entry in reports sorted by
       // inclusive metrics or call counts.
       if ($page) {
-        foreach($raw_data["main()"] as $metric => $val) {
+        foreach ($raw_data["main()"] as $metric => $val) {
           $fake_edge[$metric] = $val;
           $new_main[$metric]  = $val + 0.00001;
         }
@@ -316,7 +394,7 @@
         // if this is an old edge originating from main(), it now
         // needs to be from '__script::$page'
         if (substr($parent_child, 0, 9) == "main()==>") {
-          $child =substr($parent_child, 9);
+          $child = substr($parent_child, 9);
           // ignore the newly added edge from main()
           if (substr($child, 0, 10) != "__script::") {
             $parent_child = xhprof_build_parent_child_key("__script::$page",
@@ -381,7 +459,7 @@
 
   $metrics = xhprof_get_metrics($raw_data);
 
-  $overall_totals = array( "ct" => 0,
+  $overall_totals = array("ct" => 0,
                            "wt" => 0,
                            "ut" => 0,
                            "st" => 0,
@@ -829,6 +907,14 @@
       exit();
     }
 
+    if ($k === 'run') {
+      $p = implode(',', array_filter(explode(',', $p), 'ctype_xdigit'));
+    }
+
+    if ($k == 'symbol') {
+        $p = strip_tags($p);
+    }
+
     // create a global variable using the parameter name.
     $GLOBALS[$k] = $p;
   }
@@ -863,4 +949,3 @@
 
   return ($res);
 }
-