From 56eae394cc37084eb92ac53c409ddfae09e6884e Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Sat, 5 Sep 2015 13:16:26 +0200
Subject: [PATCH] provide details about session-creation failure.

---
 libs/ardour/ardour/session.h | 12 ++++++++++++
 libs/ardour/session.cc       | 12 ++++++------
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 2e223beba7..102cb4917e 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -22,6 +22,7 @@
 
 #include "libardour-config.h"
 
+#include <exception>
 #include <list>
 #include <map>
 #include <set>
@@ -139,6 +140,17 @@ class WindowsVSTPlugin;
 
 extern void setup_enum_writer ();
 
+class LIBARDOUR_API SessionException: public std::exception {
+public:
+	explicit SessionException(const std::string msg) : _message(msg) {}
+	virtual ~SessionException() throw() {}
+
+	virtual const char* what() const throw() { return _message.c_str(); }
+
+private:
+	std::string _message;
+};
+
 class LIBARDOUR_API Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionList, public SessionEventManager
 {
   public:
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index e1a41e8db7..b0fbe8f4d1 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -315,12 +315,12 @@ Session::Session (AudioEngine &eng,
 #endif
 		if (ensure_engine (sr)) {
 			destroy ();
-			throw failed_constructor ();
+			throw SessionException (_("Cannot connect to audio/midi engine"));
 		}
 
 		if (create (mix_template, bus_profile)) {
 			destroy ();
-			throw failed_constructor ();
+			throw SessionException (_("Session initialization failed"));
 		}
 
 		/* if a mix template was provided, then ::create() will
@@ -336,7 +336,7 @@ Session::Session (AudioEngine &eng,
 
 		if (!mix_template.empty()) { 
 			if (load_state (_current_snapshot_name)) {
-				throw failed_constructor ();
+				throw SessionException (_("Failed to load template/snapshot state"));
 			}
 			store_recent_templates (mix_template);
 		}
@@ -347,7 +347,7 @@ Session::Session (AudioEngine &eng,
 	} else {
 
 		if (load_state (_current_snapshot_name)) {
-			throw failed_constructor ();
+			throw SessionException (_("Failed to load state"));
 		}
 	
 		/* try to get sample rate from XML state so that we
@@ -364,13 +364,13 @@ Session::Session (AudioEngine &eng,
 
 		if (ensure_engine (sr)) {
 			destroy ();
-			throw failed_constructor ();
+			throw SessionException (_("Cannot connect to audio/midi engine"));
 		}
 	}
 
 	if (post_engine_init ()) {
 		destroy ();
-		throw failed_constructor ();
+		throw SessionException (_("Cannot configure audio/midi engine with session parameters"));
 	}
 
 	store_recent_sessions (_name, _path);