Wrap coroutine call in try/catch in top-level coroutine wrapper function
LLCoros::toplevel(). Distinguish exception classes derived from
LLContinueError (log and continue) from all others (crash with LL_ERRS).
Enhance CRASH_ON_UNHANDLED_EXCEPTIONS() and LOG_UNHANDLED_EXCEPTIONS() macros
to accept a context string to supplement the log message. This lets us replace
many places that called boost::current_exception_diagnostic_information() with
LOG_UNHANDLED_EXCEPTIONS() instead, since the explicit calls were mostly to
log supplemental information.
Provide supplemental information (coroutine name, function parameters) for
some of the previous LOG_UNHANDLED_EXCEPTIONS() calls. This information
duplicates LL_DEBUGS() information at the top of these functions, but in a
typical log file we wouldn't see the LL_DEBUGS() message.
Eliminate a few catch (std::exception e) clauses: the information we get from
boost::current_exception_diagnostic_information() in a catch (...) clause
makes it unnecessary to distinguish.
In a few cases, add a final 'throw;' to a catch (...) clause: having logged
the local context info, propagate the exception to be caught by higher-level
try/catch.
In a couple places, couldn't resist reconciling indentation within a
particular function: tabs where the rest of the function uses tabs, spaces
where the rest of the function uses spaces.
In LLLogin::Impl::loginCoro(), eliminate some confusing comments about an
array of rewritten URIs that date back to a long-deleted implementation.
KDU internally throws kdu_exception, which is a typedef for int. It's possible
that such an exception might leak out.
Our usual strategy for unknown exceptions is to catch (...) and let
boost::current_exception_diagnostic_information() handle them. However, for
int (or a class not derived from std::exception), that function will only
shrug and report no information available.
Besides, we want to format kdu_exception specially anyway. First, the KDU
#defines are in hex, so we should report the value in hex. But on inspection,
certain of those hex values are actually multibyte ASCII literals in disguise
-- so also report the byte string value.
Turns out we have a surprising number of catch (...) clauses in the viewer
code base. If all we currently do is
LL_ERRS() << "unknown exception" << LL_ENDL;
then call CRASH_ON_UNHANDLED_EXCEPTION() instead. If what we do is
LL_WARNS() << "unknown exception" << LL_ENDL;
then call LOG_UNHANDLED_EXCEPTION() instead.
Since many places need LOG_UNHANDLED_EXCEPTION() and nobody catches
LLContinueError yet, eliminate LLContinueError& parameter from
LOG_UNHANDLED_EXCEPTION(). This permits us to use the same log message as
CRASH_ON_UNHANDLED_EXCEPTION(), just with a different severity level.
Where a catch (...) clause actually provides contextual information, or makes
an error string, add boost::current_exception_diagnostic_information() to try
to figure out actual exception class and message.
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.
Nat Goodspeed