Merge pull request #10865 from Mic92/better-cleanup

libutil: guard Finally against invalid exception throws
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Robert Hensing 2024-06-05 23:59:51 +02:00 committed by GitHub
commit dadb6f86cf
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@ -2,6 +2,8 @@
///@file ///@file
#include <utility> #include <utility>
#include <cassert>
#include <exception>
/** /**
* A trivial class to run a function at the end of a scope. * A trivial class to run a function at the end of a scope.
@ -21,5 +23,25 @@ public:
Finally(Finally &&other) : fun(std::move(other.fun)) { Finally(Finally &&other) : fun(std::move(other.fun)) {
other.movedFrom = true; other.movedFrom = true;
} }
~Finally() { 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;
}
}
}; };