generic-tracing: fix lossage of first event

When using the generic-tracing experiment for generating a trace, the
first event, after the tracing is started (the start-symbol) is lost
in the trace. This patch handles this special case seperately.

Change-Id: Ia131a8559d67161532504160826fdb100247ed75

src/experiments/generic-tracing/experiment.cc

@@ -209,6 +209,10 @@ bool GenericTracing::run()
 	// this must be done *after* configuring the plugin:
 	simulator.addFlow(&tp);
 
+    // In order to not loose the IP event at the beginning of the
+    // trace, we have to handle the IP event manually
+    tp.handleSingleIP(l_start_symbol);
+
 	////////////////////////////////////////////////////////////////
 	// STEP 2: continue to the save point, and save state
 	if (start_symbol != save_symbol) {

src/plugins/tracing/TracingPlugin.cc

@@ -1,6 +1,7 @@
 #include <iostream>
 #include <assert.h>
 
+#include "sal/SALConfig.hpp"
 #include "sal/SALInst.hpp"
 #include "sal/Register.hpp"
 #include "sal/Memory.hpp"
@@ -10,6 +11,34 @@
 using namespace std;
 using namespace fail;
 
+void TracingPlugin::handleSingleIP(const BPListener &bp) {
+	address_t ip = bp.getTriggerInstructionPointer();
+	if (m_ipMap && !m_ipMap->isMatching(ip)) {
+		return;
+	}
+
+	m_curtime = simulator.getTimerTicks();
+	simtime_diff_t deltatime = m_curtime - m_prevtime;
+
+	if (m_os)
+		*m_os << "[Tracing] IP " << hex << ip << "\n";
+
+	if (m_protoStreamFile) {
+		Trace_Event e;
+		e.set_ip(ip);
+		// only store deltas != 0
+		if (deltatime != 0) {
+			e.set_time_delta(deltatime);
+		}
+		if (!ps) {
+			ps = new ProtoOStream (m_protoStreamFile);
+		}
+
+		ps->writeMessage(&e);
+	}
+}
+
+
 bool TracingPlugin::run()
 {
 	MemoryManager& mm = simulator.getMemoryManager();
@@ -33,14 +62,13 @@ bool TracingPlugin::run()
 
 	// the first event gets an absolute time stamp, all others a delta to their
 	// predecessor
-	simtime_t prevtime = 0, curtime;
 	simtime_diff_t deltatime;
 
 	while (true) {
 		ev = simulator.resume();
 
-		curtime = simulator.getTimerTicks();
-		deltatime = curtime - prevtime;
+		m_curtime = simulator.getTimerTicks();
+		deltatime = m_curtime - m_prevtime;
 
 		if (ev == &ev_step) {
 			simulator.addListener(&ev_step);
@@ -122,7 +150,7 @@ bool TracingPlugin::run()
 
 		// do this only if the last delta was written
 		// (no, e.g., memory map mismatch)
-		prevtime = curtime;
+		m_prevtime = m_curtime;
 	}
 
 	return true;

src/plugins/tracing/TracingPlugin.hpp

@@ -7,6 +7,8 @@
 #include "util/ProtoStream.hpp"
 #include "efw/ExperimentFlow.hpp"
 #include "config/FailConfig.hpp"
+#include "sal/Listener.hpp"
+
 
 #include "TracePlugin.pb.h"
 
@@ -48,10 +50,14 @@ private:
 	std::ostream *m_os; //!< ostream to write human-readable trace into
 	fail::ProtoOStream *ps;
 
+	fail::simtime_t m_prevtime;
+	fail::simtime_t m_curtime;
+
 public:
 	TracingPlugin(bool full_trace = false)
 	 : m_memMap(0), m_ipMap(0), m_memonly(false), m_iponly(false),
-	   m_full_trace(full_trace), m_protoStreamFile(0), m_os(0) { }
+	   m_full_trace(full_trace), m_protoStreamFile(0), m_os(0),
+	   m_prevtime(0) { }
 	bool run();
 	/**
 	 * Restricts tracing to memory addresses listed in this MemoryMap.	An
@@ -88,6 +94,13 @@ public:
 	 * ProtoStream file to trace into (trace.proto instance)
 	 */
 	void setTraceFile(std::ostream *os) { m_protoStreamFile = os; }
+
+	/**
+	 * Handles a single IP event. This is important for starting the
+	 * tracing process after triggering a breakpoint. Just pass on the
+	 * breakpoint
+	 */
+	void handleSingleIP(const fail::BPListener &bp);
 };
 
 #endif // __TRACING_PLUGIN_HPP__