diff options
Diffstat (limited to 'indra/llcommon/llexception.h')
| -rw-r--r-- | indra/llcommon/llexception.h | 104 |
1 files changed, 63 insertions, 41 deletions
diff --git a/indra/llcommon/llexception.h b/indra/llcommon/llexception.h index 3e50678b44..f58a553eb3 100644 --- a/indra/llcommon/llexception.h +++ b/indra/llcommon/llexception.h @@ -12,6 +12,7 @@ #if ! defined(LL_LLEXCEPTION_H) #define LL_LLEXCEPTION_H +#include "always_return.h" #include <stdexcept> #include <boost/exception/exception.hpp> #include <boost/throw_exception.hpp> @@ -106,90 +107,111 @@ void log_unhandled_exception_(const char*, int, const char*, const std::string&) * Structured Exception Handling *****************************************************************************/ // this is used in platform-generic code -- define outside #if LL_WINDOWS -struct Windows_SEH_exception: public std::runtime_error +struct Windows_SEH_exception: public LLException { - Windows_SEH_exception(const std::string& what): std::runtime_error(what) {} + Windows_SEH_exception(const std::string& what): LLException(what) {} }; +namespace LL +{ +namespace seh +{ + #if LL_WINDOWS //------------------------------------------------------------- -#include <functional> +void fill_stacktrace(std::string& stacktrace, U32 code); + +// wrapper around caller's U32 filter(U32 code, struct _EXCEPTION_POINTERS*) +// filter function: capture a stacktrace, if possible, before forwarding the +// call to the caller's filter() function +template <typename FILTER> +U32 filter_(std::string& stacktrace, FILTER&& filter, + U32 code, struct _EXCEPTION_POINTERS* exptrs) +{ + // By the time the handler gets control, the stack has been unwound, + // so report the stack trace now at filter() time. + fill_stacktrace(stacktrace, code); + return std::forward<FILTER>(filter)(code, exptrs); +} -// triadic variant specifies try(), filter(U32, struct _EXCEPTION_POINTERS*), -// handler(U32, const std::string& stacktrace) -// stacktrace may or may not be available template <typename TRYCODE, typename FILTER, typename HANDLER> -auto seh_catcher(TRYCODE&& trycode, FILTER&& filter, HANDLER&& handler) +auto catcher_inner(std::string& stacktrace, + TRYCODE&& trycode, FILTER&& filter, HANDLER&& handler) { - // don't try to construct a std::function at the moment of Structured Exception - std::function<U32(U32, struct _EXCEPTION_POINTERS*)> - filter_function(std::forward<FILTER>(filter)); - std::string stacktrace; __try { return std::forward<TRYCODE>(trycode)(); } - __except (ll_seh_filter( - stacktrace, - filter_function, - GetExceptionCode(), - GetExceptionInformation())) + __except (filter_(stacktrace, + std::forward<FILTER>(filter), + GetExceptionCode(), GetExceptionInformation())) { - return std::forward<HANDLER>(handler)(GetExceptionCode(), stacktrace); + return always_return<decltype(trycode())>( + std::forward<HANDLER>(handler), GetExceptionCode(), stacktrace); } } -// dyadic variant specifies try(), handler(U32, stacktrace), assumes default filter +// triadic variant specifies try(), filter(U32, struct _EXCEPTION_POINTERS*), +// handler(U32, const std::string& stacktrace) +// stacktrace may or may not be available +template <typename TRYCODE, typename FILTER, typename HANDLER> +auto catcher(TRYCODE&& trycode, FILTER&& filter, HANDLER&& handler) +{ + // Construct and destroy this stacktrace string in the outer function + // because we can't do either in the function with __try/__except. + std::string stacktrace; + return catcher_inner(stacktrace, + std::forward<TRYCODE>(trycode), + std::forward<FILTER>(filter), + std::forward<HANDLER>(handler)); +} + +// common_filter() handles the typical case in which we want our handler +// clause to handle only Structured Exceptions rather than explicitly-thrown +// C++ exceptions +U32 common_filter(U32 code, struct _EXCEPTION_POINTERS*); + +// dyadic variant specifies try(), handler(U32, stacktrace), assumes common_filter() template <typename TRYCODE, typename HANDLER> -auto seh_catcher(TRYCODE&& trycode, HANDLER&& handler) +auto catcher(TRYCODE&& trycode, HANDLER&& handler) { - return seh_catcher( - std::forward<TRYCODE>(trycode), - seh_filter, - std::forward<HANDLER>(handler)); + return catcher(std::forward<TRYCODE>(trycode), + common_filter, + std::forward<HANDLER>(handler)); } // monadic variant specifies try(), assumes default filter and handler template <typename TRYCODE> -auto seh_catcher(TRYCODE&& trycode) +auto catcher(TRYCODE&& trycode) { - return seh_catcher( - std::forward<TRYCODE>(trycode), - seh_filter, - seh_rethrow); + return catcher(std::forward<TRYCODE>(trycode), rethrow); } -// SEH exception filtering for use in __try __except -// Separates C++ exceptions from C SEH exceptions -// Todo: might be good idea to do some kind of seh_to_msc_wrapper(function, ARGS&&); -U32 ll_seh_filter( - std::string& stacktrace, - std::function<U32(U32, struct _EXCEPTION_POINTERS*)> filter, - U32 code, - struct _EXCEPTION_POINTERS* exception_infop); -U32 seh_filter(U32 code, struct _EXCEPTION_POINTERS* exception_infop); -void seh_rethrow(U32 code, const std::string& stacktrace); +[[noreturn]] void rethrow(U32 code, const std::string& stacktrace); #else // not LL_WINDOWS ----------------------------------------------------- template <typename TRYCODE, typename FILTER, typename HANDLER> -auto seh_catcher(TRYCODE&& trycode, FILTER&&, HANDLER&&) +auto catcher(TRYCODE&& trycode, FILTER&&, HANDLER&&) { return std::forward<TRYCODE>(trycode)(); } template <typename TRYCODE, typename HANDLER> -auto seh_catcher(TRYCODE&& trycode, HANDLER&&) +auto catcher(TRYCODE&& trycode, HANDLER&&) { return std::forward<TRYCODE>(trycode)(); } template <typename TRYCODE> -auto seh_catcher(TRYCODE&& trycode) +auto catcher(TRYCODE&& trycode) { return std::forward<TRYCODE>(trycode)(); } #endif // not LL_WINDOWS ----------------------------------------------------- +} // namespace LL::seh +} // namespace LL + #endif /* ! defined(LL_LLEXCEPTION_H) */ |