[Bug fortran/38993] New: better error needed for incompatible f90 modules

["colinlee at cray dot com" <gcc-bugzilla at gcc dot gnu dot org>]

When using gfortran 4.3.1 with Fortran modules compiled by older, incompatible
releases like 4.2.4, the error message emitted is vague and does not attempt to
point out the possible incompatibility between compiler and Fortran module. 
Many users keep Fortran modules around and would encounter this error on
upgrading to the newest gfortran release, but would have to hunt for an answer.

"Fatal Error: Reading module test at line 14 column 17: Expected string"

> gcc -v -save-temps
Using built-in specs.
Target: x86_64-suse-linux
Configured with: ../xt-gcc-4.3.1/configure --prefix=/opt/gcc/4.3.1/snos
--disable-nls --libdir=/opt/gcc/4.3.1/snos/lib --enable-languages=c,c++,fortran
--with-gxx-include-dir=/opt/gcc/4.3.1/snos/include/g++
--with-slibdir=/opt/gcc/4.3.1/snos/lib --with-system-zlib --enable-shared
--enable-__cxa_atexit x86_64-suse-linux --with-mpfr=/opt/gcc/4.3.1/mpfr/2.3.1
Thread model: posix
gcc version 4.3.1 20080606 (rpm:5) (GCC)


-- 
           Summary: better error needed for incompatible f90 modules
           Product: gcc
           Version: 4.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: colinlee at cray dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38993