Compile time error with GCC 11.3 (and most probably all other GCC versions)

[robert-mijakovic]

Hi guys,

I tried to compile IMB with GCC 11.3 and link it against Intel MPI, however, it failed in the process.
Basically, the issue is with a fixed size string array (aux_string) that is insufficiently long to store a warning.
Ironically, it is supposed to show a message on an overflow, and is too large to fit into the string size.
The array is defined as:
#define out_fields 8;
#define ow_format 13;
extern char aux_string[out_fieldsow_format];
Meaning it is defined as an up to a 104 byte long message.
The message itself is 106 bytes long and needs an extra byte for null termination of a string (107 bytes).

It is guarded with a MPI1 pragma but I don't understand why it actually took that path.

I guess, this should be fixed.

Best regards,
Robert

[JuliaRS]

@robert-mijakovic Thank you for your request, what warning IMB try to throw?
Do you mean this piece of code

mpi-benchmarks/src_c/IMB_declare.h

Line 160 in 71ebc45

#define ow_format 13

?

[robert-mijakovic]

../src_c/IMB_output.c:346:152: error: ' int-overflow; The productio...' directive writing 106 bytes into a region of size 104 [-Werror=format-overflow=]
  346 |                 sprintf(aux_string + offset, " int-overflow; The production rank*size caused int overflow for given sample; use flag \"-data_type double\"");
      |                                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
../src_c/IMB_output.c:346:17: note: 'sprintf' output 107 bytes into a destination of size 104
  346 |                 sprintf(aux_string + offset, " int-overflow; The production rank*size caused int overflow for given sample; use flag \"-data_type double\"");
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~```