https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67068
Bug ID: 67068 Summary: Ambiguous interfaces generated when including open mip fortran header Product: gcc Version: 5.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran Assignee: unassigned at gcc dot gnu.org Reporter: mwglass at sandia dot gov Target Milestone: --- Using gfortran-5.2.0 with openmpi 1.8.7 on a Linux RHEL system. When compiling a FORTRAN file with "-freal-4-real-8 -fdefault-double-8 -fdefault-real-8" and having the file include the mpif.h header from openmpi, gfortran generates the following error: mpif-sizeof.h:575:41: c 'mpi_sizeof_real64_r7' and 'mpi_sizeof_real32_r7' in generic interface 'mpi_sizeof' at (1) mpif-sizeof.h:1139:42: Error: Ambiguous interfaces 'pmpi_sizeof_real64_r7' and 'pmpi_sizeof_real32_r7' in generic interface 'pmpi_sizeof' at (1) mpif-sizeof.h:575:41: Error: Ambiguous interfaces 'mpi_sizeof_real64_r7' and 'mpi_sizeof_real32_r7' in generic interface 'mpi_sizeof' at (1) mpif-sizeof.h:1139:42: Error: Ambiguous interfaces 'pmpi_sizeof_real64_r7' and 'pmpi_sizeof_real32_r7' in generic interface 'pmpi_sizeof' at (1) mpif-sizeof.h:575:41: Error: Ambiguous interfaces 'mpi_sizeof_real64_r7' and 'mpi_sizeof_real32_r7' in generic interface 'mpi_sizeof' at (1) mpif-sizeof.h:1139:42: Error: Ambiguous interfaces 'pmpi_sizeof_real64_r7' and 'pmpi_sizeof_real32_r7' in generic interface 'pmpi_sizeof' at (1) All previous versions of gfortran (4,7.x, 4.8.x, 4.9.x, 5.0, and 5.1) did not do this. This also has never been a issue with the Intel fortran compile v14.x and 15.x.