From 9c49a6c91dd9b5bbe811fcd91d8992ed6bac33e7 Mon Sep 17 00:00:00 2001 From: Nat Goodspeed Date: Tue, 19 Jul 2016 16:25:25 -0400 Subject: MAINT-5011: Introduce LLException base class for viewer exceptions. This also introduces LLContinueError for exceptions which should interrupt some part of viewer processing (e.g. the current coroutine) but should attempt to let the viewer session proceed. Derive all existing viewer exception classes from LLException rather than from std::runtime_error or std::logic_error. Use BOOST_THROW_EXCEPTION() rather than plain 'throw' to enrich the thrown exception with source file, line number and containing function. --- indra/llcommon/llexception.h | 63 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 indra/llcommon/llexception.h (limited to 'indra/llcommon/llexception.h') diff --git a/indra/llcommon/llexception.h b/indra/llcommon/llexception.h new file mode 100644 index 0000000000..3ac2f4762f --- /dev/null +++ b/indra/llcommon/llexception.h @@ -0,0 +1,63 @@ +/** + * @file llexception.h + * @author Nat Goodspeed + * @date 2016-06-29 + * @brief Types needed for generic exception handling + * + * $LicenseInfo:firstyear=2016&license=viewerlgpl$ + * Copyright (c) 2016, Linden Research, Inc. + * $/LicenseInfo$ + */ + +#if ! defined(LL_LLEXCEPTION_H) +#define LL_LLEXCEPTION_H + +#include +#include + +/** + * LLException is intended as the common base class from which all + * viewer-specific exceptions are derived. It is itself a subclass of + * boost::exception; use catch (const boost::exception& e) clause to log the + * string from boost::diagnostic_information(e). + * + * Since it is also derived from std::exception, a generic catch (const + * std::exception&) should also work, though what() is unlikely to be as + * informative as boost::diagnostic_information(). + * + * Please use BOOST_THROW_EXCEPTION() + * http://www.boost.org/doc/libs/release/libs/exception/doc/BOOST_THROW_EXCEPTION.html + * to throw viewer exceptions whenever possible. This enriches the exception's + * diagnostic_information() with the source file, line and containing function + * of the BOOST_THROW_EXCEPTION() macro. + * + * There may be circumstances in which it would be valuable to distinguish an + * exception explicitly thrown by viewer code from an exception thrown by + * (say) a third-party library. Catching (const LLException&) supports such + * usage. However, most of the value of this base class is in the + * diagnostic_information() available via Boost.Exception. + */ +struct LLException: + public std::runtime_error, + public boost::exception +{ + LLException(const std::string& what): + std::runtime_error(what) + {} +}; + +/** + * The point of LLContinueError is to distinguish exceptions that need not + * terminate the whole viewer session. In general, an uncaught exception will + * be logged and will crash the viewer. However, though an uncaught exception + * derived from LLContinueError will still be logged, the viewer will attempt + * to continue processing. + */ +struct LLContinueError: public LLException +{ + LLContinueError(const std::string& what): + LLException(what) + {} +}; + +#endif /* ! defined(LL_LLEXCEPTION_H) */ -- cgit v1.2.3 From 1ed76c382e8b87bff02b6d37cf8acd7f6b1f8063 Mon Sep 17 00:00:00 2001 From: Nat Goodspeed Date: Wed, 17 Aug 2016 10:45:06 -0400 Subject: 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. --- indra/llcommon/llexception.h | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) (limited to 'indra/llcommon/llexception.h') diff --git a/indra/llcommon/llexception.h b/indra/llcommon/llexception.h index 3ac2f4762f..68bd20fbcd 100644 --- a/indra/llcommon/llexception.h +++ b/indra/llcommon/llexception.h @@ -15,15 +15,20 @@ #include #include +// "Found someone who can comfort me +// But there are always exceptions..." +// - Empty Pages, Traffic, from John Barleycorn (1970) +// https://www.youtube.com/watch?v=dRH0CGVK7ic + /** * LLException is intended as the common base class from which all - * viewer-specific exceptions are derived. It is itself a subclass of - * boost::exception; use catch (const boost::exception& e) clause to log the - * string from boost::diagnostic_information(e). + * viewer-specific exceptions are derived. Rationale for why it's derived from + * both std::exception and boost::exception is explained in + * tests/llexception_test.cpp. * - * Since it is also derived from std::exception, a generic catch (const - * std::exception&) should also work, though what() is unlikely to be as - * informative as boost::diagnostic_information(). + * boost::current_exception_diagnostic_information() is quite wonderful: if + * all we need to do with an exception is log it, in most places we should + * catch (...) and log boost::current_exception_diagnostic_information(). * * Please use BOOST_THROW_EXCEPTION() * http://www.boost.org/doc/libs/release/libs/exception/doc/BOOST_THROW_EXCEPTION.html @@ -60,4 +65,14 @@ struct LLContinueError: public LLException {} }; +/// Call this macro from a catch (...) clause +#define CRASH_ON_UNHANDLED_EXCEPTION() \ + crash_on_unhandled_exception_(__FILE__, __LINE__, __PRETTY_FUNCTION__) +void crash_on_unhandled_exception_(const char*, int, const char*); + +/// Call this from a catch (const LLContinueError&) clause +#define LOG_UNHANDLED_EXCEPTION(EXC) \ + log_unhandled_exception_(__FILE__, __LINE__, __PRETTY_FUNCTION__, EXC) +void log_unhandled_exception_(const char*, int, const char*, const LLContinueError&); + #endif /* ! defined(LL_LLEXCEPTION_H) */ -- cgit v1.2.3 From 5e9d2f57c82a57307a48afea09aa539b9fa80abf Mon Sep 17 00:00:00 2001 From: Nat Goodspeed Date: Wed, 17 Aug 2016 11:36:24 -0400 Subject: MAINT-5011: Use LLTHROW() instead of plain BOOST_THROW_EXCEPTION(). A level of preprocessor indirection lets us later change the implementation if desired. --- indra/llcommon/llexception.h | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'indra/llcommon/llexception.h') diff --git a/indra/llcommon/llexception.h b/indra/llcommon/llexception.h index 68bd20fbcd..e9e25ae689 100644 --- a/indra/llcommon/llexception.h +++ b/indra/llcommon/llexception.h @@ -14,6 +14,7 @@ #include #include +#include // "Found someone who can comfort me // But there are always exceptions..." @@ -30,12 +31,6 @@ * all we need to do with an exception is log it, in most places we should * catch (...) and log boost::current_exception_diagnostic_information(). * - * Please use BOOST_THROW_EXCEPTION() - * http://www.boost.org/doc/libs/release/libs/exception/doc/BOOST_THROW_EXCEPTION.html - * to throw viewer exceptions whenever possible. This enriches the exception's - * diagnostic_information() with the source file, line and containing function - * of the BOOST_THROW_EXCEPTION() macro. - * * There may be circumstances in which it would be valuable to distinguish an * exception explicitly thrown by viewer code from an exception thrown by * (say) a third-party library. Catching (const LLException&) supports such @@ -65,6 +60,15 @@ struct LLContinueError: public LLException {} }; +/** + * Please use LLTHROW() to throw viewer exceptions whenever possible. This + * enriches the exception's diagnostic_information() with the source file, + * line and containing function of the LLTHROW() macro. + */ +// Currently we implement that using BOOST_THROW_EXCEPTION(). Wrap it in +// LLTHROW() in case we ever want to revisit that implementation decision. +#define LLTHROW(x) BOOST_THROW_EXCEPTION(x) + /// Call this macro from a catch (...) clause #define CRASH_ON_UNHANDLED_EXCEPTION() \ crash_on_unhandled_exception_(__FILE__, __LINE__, __PRETTY_FUNCTION__) -- cgit v1.2.3 From 993f54f6e91d78a9c2e1389ad878d6bd46e9be5b Mon Sep 17 00:00:00 2001 From: Nat Goodspeed Date: Wed, 17 Aug 2016 15:40:03 -0400 Subject: MAINT-5011: Try to enrich catch (...) logging throughout viewer. 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. --- indra/llcommon/llexception.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'indra/llcommon/llexception.h') diff --git a/indra/llcommon/llexception.h b/indra/llcommon/llexception.h index e9e25ae689..2a0f5e79eb 100644 --- a/indra/llcommon/llexception.h +++ b/indra/llcommon/llexception.h @@ -74,9 +74,10 @@ struct LLContinueError: public LLException crash_on_unhandled_exception_(__FILE__, __LINE__, __PRETTY_FUNCTION__) void crash_on_unhandled_exception_(const char*, int, const char*); -/// Call this from a catch (const LLContinueError&) clause -#define LOG_UNHANDLED_EXCEPTION(EXC) \ - log_unhandled_exception_(__FILE__, __LINE__, __PRETTY_FUNCTION__, EXC) -void log_unhandled_exception_(const char*, int, const char*, const LLContinueError&); +/// Call this from a catch (const LLContinueError&) clause, or from a catch +/// (...) clause in which you do NOT want the viewer to crash. +#define LOG_UNHANDLED_EXCEPTION() \ + log_unhandled_exception_(__FILE__, __LINE__, __PRETTY_FUNCTION__) +void log_unhandled_exception_(const char*, int, const char*); #endif /* ! defined(LL_LLEXCEPTION_H) */ -- cgit v1.2.3 From c7bf8af6378a54c3d03e77b161b7ba3b36186576 Mon Sep 17 00:00:00 2001 From: Nat Goodspeed Date: Thu, 18 Aug 2016 11:06:51 -0400 Subject: MAINT-5011: Use BOOST_CURRENT_FUNCTION instead of __PRETTY_FUNCTION__ since Visual Studio doesn't know __PRETTY_FUNCTION__, and Boost already has a portable macro to Do The Right Thing. --- indra/llcommon/llexception.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'indra/llcommon/llexception.h') diff --git a/indra/llcommon/llexception.h b/indra/llcommon/llexception.h index 2a0f5e79eb..384b2271fb 100644 --- a/indra/llcommon/llexception.h +++ b/indra/llcommon/llexception.h @@ -15,6 +15,7 @@ #include #include #include +#include // "Found someone who can comfort me // But there are always exceptions..." @@ -71,13 +72,13 @@ struct LLContinueError: public LLException /// Call this macro from a catch (...) clause #define CRASH_ON_UNHANDLED_EXCEPTION() \ - crash_on_unhandled_exception_(__FILE__, __LINE__, __PRETTY_FUNCTION__) + crash_on_unhandled_exception_(__FILE__, __LINE__, BOOST_CURRENT_FUNCTION) void crash_on_unhandled_exception_(const char*, int, const char*); /// Call this from a catch (const LLContinueError&) clause, or from a catch /// (...) clause in which you do NOT want the viewer to crash. #define LOG_UNHANDLED_EXCEPTION() \ - log_unhandled_exception_(__FILE__, __LINE__, __PRETTY_FUNCTION__) + log_unhandled_exception_(__FILE__, __LINE__, BOOST_CURRENT_FUNCTION) void log_unhandled_exception_(const char*, int, const char*); #endif /* ! defined(LL_LLEXCEPTION_H) */ -- cgit v1.2.3 From 4d10172d8b2c72fa809e322a3b4ff326b19ff340 Mon Sep 17 00:00:00 2001 From: Nat Goodspeed Date: Thu, 18 Aug 2016 17:33:44 -0400 Subject: MAINT-5011: Catch unhandled exceptions in LLCoros coroutines. 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. --- indra/llcommon/llexception.h | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'indra/llcommon/llexception.h') diff --git a/indra/llcommon/llexception.h b/indra/llcommon/llexception.h index 384b2271fb..dfcb7c192f 100644 --- a/indra/llcommon/llexception.h +++ b/indra/llcommon/llexception.h @@ -31,6 +31,7 @@ * boost::current_exception_diagnostic_information() is quite wonderful: if * all we need to do with an exception is log it, in most places we should * catch (...) and log boost::current_exception_diagnostic_information(). + * See CRASH_ON_UNHANDLED_EXCEPTION() and LOG_UNHANDLED_EXCEPTION() below. * * There may be circumstances in which it would be valuable to distinguish an * exception explicitly thrown by viewer code from an exception thrown by @@ -71,14 +72,14 @@ struct LLContinueError: public LLException #define LLTHROW(x) BOOST_THROW_EXCEPTION(x) /// Call this macro from a catch (...) clause -#define CRASH_ON_UNHANDLED_EXCEPTION() \ - crash_on_unhandled_exception_(__FILE__, __LINE__, BOOST_CURRENT_FUNCTION) -void crash_on_unhandled_exception_(const char*, int, const char*); +#define CRASH_ON_UNHANDLED_EXCEPTION(CONTEXT) \ + crash_on_unhandled_exception_(__FILE__, __LINE__, BOOST_CURRENT_FUNCTION, CONTEXT) +void crash_on_unhandled_exception_(const char*, int, const char*, const std::string&); /// Call this from a catch (const LLContinueError&) clause, or from a catch /// (...) clause in which you do NOT want the viewer to crash. -#define LOG_UNHANDLED_EXCEPTION() \ - log_unhandled_exception_(__FILE__, __LINE__, BOOST_CURRENT_FUNCTION) -void log_unhandled_exception_(const char*, int, const char*); +#define LOG_UNHANDLED_EXCEPTION(CONTEXT) \ + log_unhandled_exception_(__FILE__, __LINE__, BOOST_CURRENT_FUNCTION, CONTEXT) +void log_unhandled_exception_(const char*, int, const char*, const std::string&); #endif /* ! defined(LL_LLEXCEPTION_H) */ -- cgit v1.2.3