Conséquences de l'utilisation de la manipulation des exceptions structurées (SEH)?
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15-11-2019 - |
Question
Je vois que Doug Harrison a fait une bonne déclaration de ce qui est "faux" avec l'utilisation d'exceptions structurées (c.-à-d. Attraper) (voir
Mais ce n'est qu'un exemple.Quelles autres problèmes pourraient-il y avoir?
La solution
/EHa disables an optimization. With /EHs in effect, the compiler can omit exception filters if it can be sure that no C++ exception is ever thrown by the code wrapped in a try {}. That's a small space optimization on x86 and x64, very small time optimization on x86. Problem is, those filters are needed if you catch non-C++ exceptions. The consequence is that the stack gets unwound when such an exception is caught without the destructor of a C++ object getting called. Not good, /EHa avoids it.
Mixing doesn't cause linker problems. It causes the above problem.
Yes, /EHa also makes catch(...) do a very stupid thing, it really catches everything. That ship wreck sailed a while ago though, Pokemon C++ exception handling is a bad idea too.