source: CIVL/examples/omp/amg2013/NOTES@ 1aaefd4

Current problem:
1. A abc bug illustrated by abcBug.c, abcBugHead1.h and abcBugHead2.h

2. Error: Undeclared identifier sysconf
at timer.c:45.41-47 "sysconf"  

sysconf looks like a constant defined in standard library.



[unused file]
ABC v0.2 of 31-mar-2014 -- http://vsl.cis.udel.edu/abc

Error: Expected 14 arguments but saw 13
at par_difconv.c:224.34-225.73 "hypre_map(ix,iy,iz-1 ... )"


[solved]
ABC v0.2 of 31-mar-2014 -- http://vsl.cis.udel.edu/abc

Error: No conversion from type of right hand side to that of left:
(void) *
struct MPI_Comm
at gen_redcs_mat.c:449.6-mpi.h:5.22 "new_comm = ((void*) ... )"
make: *** [abc_amg2013] Error 6




AMG2013/parcsr_ls/

Probably what happened is: this file was read in after mpi.h was read.
However in reality, this file will be preprocessed and compiled with other headers
insteaed of mpi.h.  In those headers, MPI_Comm is defined to be int, and
MPI_COMM_NULL is (-1).

Here are the includes:

#include "parcsr_ls.h"
#include "parcsr_mv.h"
#include "seq_mv.h"
#include "par_amg.h"

In parcsr_ls.h:
#include "HYPRE_parcsr_ls.h"
...
#include "utilities.h"

utilities.h includes HYPRE_utilities.h.

In HYPRE_utilities.h, mpi.h is included first.

In utilities.h there is  then a bunch of #defines which redefine MPI_Comm, etc.

In mpi.h:  typedef struct MPI_Comm MPI_Comm;

In utilities.h:
#define MPI_Comm            hypre_MPI_Comm            
...
typedef int hypre_MPI_Comm;