MAINT-5011: Add llexception_test.cpp with tests (and conclusions).

llexception_test.cpp is an unusual test source in that it need not be verified
on every build, so its invocation in indra/llcommon/CMakeLists.txt is
commented out with that remark. Its purpose is to help a developer decide what
base class(es) to use for LLException, how to throw and how to catch.

Our current conclusions are written up as comments in llexception_test.cpp.

Added CRASH_ON_UNHANDLED_EXCEPTION() and LOG_UNHANDLED_EXCEPTION() macros to
llexception.h -- macros to log __FILE__, __LINE__ and __PRETTY_FUNCTION__ of
the catch site. These invoke functions in llexception.cpp so we don't need to
#include llerror.h for every possible catch site.

1 files changed, 41 insertions, 0 deletions

diff --git a/indra/llcommon/llexception.cpp b/indra/llcommon/llexception.cpp
new file mode 100644
index 0000000000..f48509b2aa
--- /dev/null
+++ b/indra/llcommon/llexception.cpp
@@ -0,0 +1,41 @@
+/**
+ * @file   llexception.cpp
+ * @author Nat Goodspeed
+ * @date   2016-08-12
+ * @brief  Implementation for llexception.
+ * 
+ * $LicenseInfo:firstyear=2016&license=viewerlgpl$
+ * Copyright (c) 2016, Linden Research, Inc.
+ * $/LicenseInfo$
+ */
+
+// Precompiled header
+#include "linden_common.h"
+// associated header
+#include "llexception.h"
+// STL headers
+// std headers
+#include <typeinfo>
+// external library headers
+#include <boost/exception/diagnostic_information.hpp>
+// other Linden headers
+#include "llerror.h"
+
+void crash_on_unhandled_exception_(const char* file, int line, const char* pretty_function)
+{
+    // LL_ERRS() terminates, but also propagates message into crash dump.
+    LL_ERRS() << file << "(" << line << "): Unhandled exception caught in " << pretty_function
+              << ":\n" << boost::current_exception_diagnostic_information() << LL_ENDL;
+}
+
+void log_unhandled_exception_(const char* file, int line, const char* pretty_function,
+                             const LLContinueError& e)
+{
+    // Use LL_WARNS() because we seriously do not expect this to happen
+    // routinely, but we DO expect to return from this function. Deriving your
+    // exception from LLContinueError implies that such an exception should
+    // NOT be fatal to the viewer, only to its current task.
+    LL_WARNS() << file << "(" << line << "): Unhandled " << typeid(e).name()
+               << " exception caught in " << pretty_function
+               << ":\n" << boost::current_exception_diagnostic_information() << LL_ENDL;
+}