HP C/aC++ for PA-RISC Software manual Memory Allocation Failure and operator new

calls made through a callback mechanism). If such calls do exist, and an exception is thrown, the unwinding can cause:

•non-destruction of local objects (including compiler generated temporaries)

•memory leaks when destructors are not executed

•runtime errors when no catch clause is found

Memory Allocation Failure and operator new

In HP aC++ programs, when either operator new ( ) or operator new [ ] cannot obtain a block of storage, a bad_alloc exception results. This is required by the ANSI/ISO C++ International Standard.

In HP C++, memory allocation failures return a null pointer (zero) to the caller of operator new ().

To handle memory allocation failures in HP aC++ and to avoid a program abort, do one of the following:

•Write try or catch clauses to handle the bad_alloc exception.

•Use the nothrow_t parameter to specify the type when calling operator new and check for a null pointer.

Example:

operator new (size_t size, const nothrow_t &) throw(); operator new [] (size_t size, const nothrow_t &) throw();

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#include <new.h> #include <stdexcept>

class X{};
void foo1() {
X* xp1 = new(nothrow())X;	// returns 0 when creating a nothrow
	// object, if space is not allocated
}
void foo2() {
X* xp2 = newX:	// may throw bad_alloc
}
int main() {

try { foo1(); foo2();

}

catch (bad_alloc) {

// code to handle bad_alloc

}

catch(...) {

// code to handle all other exceptions

}

}

Possible Differences when Exiting a Signal Handler

Behavior when exiting a signal handler through a throw may differ between the two compilers.

Migration Considerations when Using Exception Handling 203