On Jul 24 2012, William Gropp wrote:

I've run my code checker over the examples in the MPI-3 Standard, and I've found some issues. Perhaps the biggest is this (a typical example):

Opening file one-side-2.tex ex5501.c: In function 'main': ex5501.c:58: warning: passing argument 2 of 'MPI_Init' from incompatible pointer type

This occurs everywhere we include MPI_Init in an example. The compiler is gcc 4.2.1 . The corresponding declaration of argv is as intended:

int main(int argc, char *argv[])

The declaration in MPI_Init looks correct (argv is a pointer to an array of pointers to char). Is this a place where we should stick with the *** notation just to keep compilers happy? Or is there something I'm missing in the declaration?

How does your code checker work? This is an area where the C standard is ambiguous, but 'everybody knows' what it is supposed to mean. I tried to get it fixed several times in WG14, but failed every time :-( C++ is subtly different, and it is just about possible that you have tripped across something there. But it is an area which is so fiendish that few people can even imagine the horrors hidden under the carpet. If you can send me a code fragment and compilation command, including the exact declaration of MPI_Init, sufficient to reproduce the effect, I will check whether it is a bug in your checker or what. Regards, Nick Maclaren.