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    <p>OK well generally speaking exception handling is highly operating system dependent. I am going to make some assumptions and try to provide some generic guidance. Please know that this is by no means an exhaustive reply, but should serve as a place to start.</p> <p>I will assume that:</p> <ol> <li><p>For the most part, you are interested in safeguarding against memory leaks.</p></li> <li><p>You are not interested in Windows (which is whole-other-ball-of-wax) since you mentioned dlopen (you would have said LoadLibrary otherwise)</p></li> <li><p>That you are aware of the nuances of linking against C++ symbols. If you are not read up on it at <a href="http://www.isotton.com/devel/docs/C++-dlopen-mini-HOWTO/C++-dlopen-mini-HOWTO.html#id303308" rel="nofollow noreferrer">mini howto on dlopen c++</a></p></li> </ol> <p><strong>Generally speaking</strong></p> <p>There is no general solution to the described problem without involving specialized operating systems that provide data and code segment sand-boxing there are Trusted Systems and specialty operating system kernels that can do this, but i assume that you want to do this on a good old *nix or windows environment.</p> <p>Compiler stuff further complicates issues (does your C++ compiler generate weak symbols by default? typically it would) This affects how exception handling happens in a try-catch.</p> <p>Simple operating system exception handling that raises signals (SIGSEGV, SIGFPE etc.):</p> <p><strong>Under POSIX system supporting <em>sigaction</em>...</strong></p> <p>Let's say you want to protect against generic things like bad memory addressing. Trap the SIGSEG using sigaction before dlopening a library (to protect against .init functions) and then also do a signal check before calling a function within the library. Consider using SA_STACK to ensure that your handler jumps into a stack you have good control over, and SA_SIGINFO to ensure that your handler gets info about the source.</p> <p>A good place to start on this is at the <a href="http://www.gnu.org/s/libc/manual/html_node/Signal-Handling.html#Signal-Handling" rel="nofollow noreferrer">Signal handling on GNU libc manual</a></p> <p><strong>Under C++: use wrappers and with try-catch to catch soft exceptions</strong></p> <p>try { foo(); } catch() { // do something }</p> <p>where foo is a weak symbol pointing to a function in your dll <a href="http://www.isotton.com/devel/docs/C++-dlopen-mini-HOWTO/C++-dlopen-mini-HOWTO.html#id303308" rel="nofollow noreferrer">see c++ dlopen mini-howto for a lot more examples and details on loading classes etc.</a></p> <p>If you have more specific needs, post them, i'll see if i can provide more info.</p> <p>Cheers</p>
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