C ++中的SIGSEGV崩溃预防

Question

What is wrong in preventing SIGSEGV crashes by putting the body of main inside a __try{} __catch{} block? Anyway nothing bad would have happened since the OS would have prevented it, and I would have just failed in whatever operation I tried to perform. I agree this is not the correct thing to do. But what are problems other than that I might fail some operations?

Answer 1

What is wrong in preventing SIGSEGV crashes by putting the body of main inside a __try{} __catch{} block?

It is probably not guaranteed to fix the problem. Most things that result in SIGSEGV are caused by undefined behaviour. When the behaviour of the program is undefined, it is not guaranteed to receive a SIGSEGV, nor is it guaranteed to behave as you would want. Any behaviour is possible. In that situation the safest thing to do is often to terminate the process.

Using __try{} __catch{} just in case is not by itself necessarily wrong, but do note that this is a compiler and system specific feature and so you need to take additional steps to keep your program portable to other compilers and systems if you care about that.

Furthermore, letting the program crash usually has the advantage that the operating system can generate a core dump for you, which can be used to debug the program to possibly find out the cause of the crash. I'm not intimately familiar with __try{} __catch{} but if it unwinds the stack like the regular catch does, then the call trace information is lost, potentially making debugging harder.