config: Add a --without-python option to build process

Add the ability to build libgem5 without embedded Python or the
ability to configure with Python.

This is a prelude to a patch to allow config.ini files to be loaded
into libgem5 using only C++ which would make embedding gem5 within
other simulation systems easier.

This adds a few registration interfaces to things which cross
between Python and C++.  Namely: stats dumping and SimObject resolving

src/base/statistics.cc

@@ -462,9 +462,31 @@ Formula::str() const
     return root ? root->str() : "";
 }
 
+Handler resetHandler = NULL;
+Handler dumpHandler = NULL;
+
+void
+registerHandlers(Handler reset_handler, Handler dump_handler)
+{
+    resetHandler = reset_handler;
+    dumpHandler = dump_handler;
+}
+
 CallbackQueue dumpQueue;
 CallbackQueue resetQueue;
 
+void
+processResetQueue()
+{
+    resetQueue.process();
+}
+
+void
+processDumpQueue()
+{
+    dumpQueue.process();
+}
+
 void
 registerResetCallback(Callback *cb)
 {
@@ -488,6 +510,24 @@ enable()
     _enabled = true;
 }
 
+void
+dump()
+{
+    if (dumpHandler)
+        dumpHandler();
+    else
+        fatal("No registered Stats::dump handler");
+}
+
+void
+reset()
+{
+    if (resetHandler)
+        resetHandler();
+    else
+        fatal("No registered Stats::reset handler");
+}
+
 void
 registerDumpCallback(Callback *cb)
 {

src/base/statistics.hh

@@ -3208,6 +3208,15 @@ void reset();
 void enable();
 bool enabled();
 
+/**
+ * Register reset and dump handlers.  These are the functions which
+ * will actually perform the whole statistics reset/dump actions
+ * including processing the reset/dump callbacks
+ */
+typedef void (*Handler)();
+
+void registerHandlers(Handler reset_handler, Handler dump_handler);
+
 /**
  * Register a callback that should be called whenever statistics are
  * reset
@@ -3220,6 +3229,16 @@ void registerResetCallback(Callback *cb);
  */
 void registerDumpCallback(Callback *cb);
 
+/**
+ * Process all the callbacks in the reset callbacks queue
+ */
+void processResetQueue();
+
+/**
+ * Process all the callbacks in the dump callbacks queue
+ */
+void processDumpQueue();
+
 std::list<Info *> &statsList();
 
 typedef std::map<const void *, Info *> MapType;