Non-consistent exit statuses

[prj-]

The exit statuses of functions are non-consistent in the library, e.g., PMMG_Set_meshSize returns 1 on success, while PMMG_bdryUpdate returns PMMG_SUCCESS (defined to 0) on success. Would it be possible to follow the standard and always return 0 (or PMMG_SUCCESS) on success? Otherwise, it makes error checking in calling libraries extremely difficult to handle, see, e.g., https://gitlab.com/petsc/petsc/-/merge_requests/4889#note_863666426, as one needs to jump back and forth between if (return code != 1) // calling-library custom error-handling and if (return code != 0) // calling-library custom error-handling.

[prj-]

If you do not plan on addressing this in the near future, could you please generate two parsable lists of functions: the ones that return PMMG_SUCCESS on success and the ones that return 1 on success?

[lcirrottola]

Hello,
I agree that this is ambiguous. The short answer is that internal functions should return 1 on success and 0 on failure, while "high level" functions (those in parmmg.c, libparmmg.cand libparmmg1.c should use exit codes PMMG_SUCCESS, PMMG_LOWFAILURE and PMMG_STRONGFAILURE to differentiate the two failing cases where a mesh can be returned to the user or not. Anyway the two conventions are mixed for functions provided in the API...

This behaviour has been basically inherited from Mmg so I think you will see the same problem in coupling Mmg.

I will see with @Algiane what we can do to make the behaviour more friendly for automatic error checking, either the list you suggest or fixing error codes for the functions provided in libparmmg.h.

[prj-]

You are correct, this is « consistent » with Mmg, see MmgTools/mmg#131.

[lcirrottola]

FYI @taupalosaurus