[mpich-devel] Issue with MPI_Error_string() for user-defined codes/clases

[Rob Latham]

On 04/22/2014 04:04 AM, Lisandro Dalcin wrote:
> The following simple tests segfaults. A quick fix would be to return
> an empty string in MPIR_Err_get_dynerr_string() (file dynerrutil.c),

I don't muck around in this code very often, so after thinking about it 
for a bit, and coming up with another way to do it, I opened a ticket so 
i could get a second (third, I guess) opinion:

https://trac.mpich.org/projects/mpich/ticket/2067

==rob

> e.g:
>
> diff --git a/src/mpi/errhan/dynerrutil.c b/src/mpi/errhan/dynerrutil.c
> index 943e8c3..fb40469 100644
> --- a/src/mpi/errhan/dynerrutil.c
> +++ b/src/mpi/errhan/dynerrutil.c
> @@ -297,11 +297,13 @@ const char *MPIR_Err_get_dynerr_string( int code )
>       if (errcode) {
>    if (errcode < first_free_code) {
>       errstr = user_code_msgs[errcode];
> +    if (!errstr) errstr = "";
>    }
>       }
>       else {
>    if (errclass < first_free_class) {
>       errstr = user_class_msgs[errclass];
> +    if (!errstr) errstr = "";
>    }
>       }
>
>
> [dalcinl at kw2060 ~]$ cat error_string2.c
> #include <stdio.h>
> #include <mpi.h>
> int main(int argc, char *argv[])
> {
>    int errorclass;
>    char errorstring[MPI_MAX_ERROR_STRING] = {64,0};
>    int slen;
>    MPI_Init(&argc, &argv);
>    MPI_Add_error_class(&errorclass);
>    MPI_Error_string(errorclass, errorstring, &slen);
>    printf("errorclass:%d errorstring:'%s' len:%d\n", errorclass,
> errorstring, slen);
>    MPI_Finalize();
>    return 0;
> }

-- 
Rob Latham
Mathematics and Computer Science Division
Argonne National Lab, IL USA