On 3/12/21 7:43 PM, xiaoyan yu wrote:
I am writing C++ program based on R extensions and also try to test the
program with google address sanitizer.

I thought if I don't protect the variable from the allocation API such as
Rf_allocVector, there will be a memory leak. However, the address sanitizer
didn't report it. Is my understanding correct? Or I will see the memory
leak only if I compile R source code with the address sanitizer.

Yes, you should use special options for compilation and linking to use address sanitizer. See Writing R Extensions, section 4.3.3.

If you allocate an R object using Rf_allocVector(), but don't protect it, it means this object is available for the garbage collector to reclaim. So it is not a memory leak.

Memory leaks with a garbage collector are much less common than without, because if the program loses a pointer to some piece of memory, that piece will automatically be reclaimed (not leaked). Still, memory leaks are possible if the program forgets about a pointer to some piece of memory no longer needed, and keeps that pointer in say some global structure. Such memory leaks would not be found using address sanitizer.

Address sanitizer/Undefined behavior sanitizer can sometimes find errors caused by that the program forgets to protect an R object, but this is relatively rare, as they don't understand R heap specifically, so you cannot assume that if you create such example, the error will always be found.

Best
Tomas


  Please help!

Thanks,
Xiaoyan

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