diff options
| -rw-r--r-- | src/libutil/finally.hh | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/src/libutil/finally.hh b/src/libutil/finally.hh index f2293e5d4..cbfd6195b 100644 --- a/src/libutil/finally.hh +++ b/src/libutil/finally.hh @@ -1,6 +1,9 @@ #pragma once ///@file +#include <cassert> +#include <exception> + /** * A trivial class to run a function at the end of a scope. */ @@ -19,5 +22,25 @@ public: Finally(Finally &&other) : fun(std::move(other.fun)) { other.movedFrom = true; } - ~Finally() noexcept(false) { if (!movedFrom) fun(); } + ~Finally() noexcept(false) + { + try { + if (!movedFrom) + fun(); + } catch (...) { + // finally may only throw an exception if exception handling is not already + // in progress. if handling *is* in progress we have to return cleanly here + // but are still prohibited from doing so since eating the exception would, + // in almost all cases, mess up error handling even more. the only good way + // to handle this is to abort entirely and leave a message, so we'll assert + // (and rethrow anyway, just as a defense against possible NASSERT builds.) + if (std::uncaught_exceptions()) { + assert(false && + "Finally function threw an exception during exception handling. " + "this is not what you want, please use some other methods (like " + "std::promise or async) instead."); + } + throw; + } + } }; |