Re: OPENMP_FLAGS in autoconf not working

[Rudra Banerjee]

Hi Nick,
Taking all your comments into account, my current configure.ac is:
#!/bin/bash 

AC_INIT([src], [0.4],[],
        [kmc],[])

AC_LANG([Fortran])

AC_CONFIG_AUX_DIR([build-aux])
AC_CONFIG_HEADERS([config.h])
AC_CONFIG_MACRO_DIR([m4])
AM_INIT_AUTOMAKE([1.9.6 dist-bzip2 subdir-objects foreign])

#AC_SEARCH_LIBS([dsyev_], [lapack], ,AC_MSG_ERROR([No LAPACK library]))
AC_PROG_FC([ifort gfortran])
AC_OPENMP
printf 'OPENMP_FCFLAGS = %s\n' "$OPENMP_FCFLAGS"
FCFLAGS="$OPENMP_FCFLAGS -fcheck=all"
if test $FC == "ifort"; then
  FCFLAGS="$OPENMP_FCFLAGS -check all"
fi
AC_CHECK_PROG([DEPF90_CHECK],[makedepf90],[yes],[no])
AM_CONDITIONAL([FOUND_MAKEDEPF90], [test "x$DEPF90_CHECK" = xyes])
AC_CONFIG_FILES([
                 Makefile
                 ])
AC_OUTPUT

Here also, `AC_LANG` is crashing the make:

./configure 
checking for a BSD-compatible install... /usr/bin/install -c
checking whether build environment is sane... yes
checking for a thread-safe mkdir -p... /usr/bin/mkdir -p
checking for gawk... gawk
checking whether make sets $(MAKE)... yes
checking whether make supports nested variables... yes
checking for ifort... ifort
checking whether the Fortran compiler works... yes
checking for Fortran compiler default output file name... a.out
checking for suffix of executables... 
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU Fortran compiler... no
checking whether ifort accepts -g... yes
checking for ifort option to support OpenMP... -fopenmp
OPENMP_FCFLAGS = -fopenmp
checking for makedepf90... yes
checking that generated files are newer than configure... done
configure: creating ./config.status
config.status: creating Makefile
config.status: creating config.h
config.status: config.h is unchanged


$make
Makefile:752: *** missing separator.  Stop.


if I just comment out AC_LANG line, then, as you said, OPENMP_FCFLAGS
doesnot have a value:

checking whether we are using the GNU Fortran compiler... no
checking whether ifort accepts -g... yes
checking for style of include used by make... GNU
checking for gcc... gcc
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking whether gcc understands -c and -o together... yes
checking dependency style of gcc... none
checking for gcc option to support OpenMP... -fopenmp
OPENMP_FCFLAGS = 
checking for makedepf90... yes
checking that generated files are newer than configure... done
configure: creating ./config.status
config.status: creating Makefile
config.status: creating config.h
config.status: config.h is unchanged
config.status: executing depfiles commands

But the make is running:
make
make  all-am
...
make[1]: Leaving directory '/home/rudra/Devel/kmc/NEW'

The difference between the configure.ac is the AC_LANG is commented;
Nothing else has been changed in this two.
Please comment.

On Thu, 2016-06-23 at 10:24 -0400, Nick Bowler wrote:
> Hello,
> 
> The tests performed by AC_OPENMP (and the variables set) depend on
> the current language.  You have not posted a complete, compilable
> configure.ac, but unless you've done something else to switch the
> language, the default language is C.
> 
> It's also strange to test for openmp before testing the compiler --
> this will probably not do what you intended.  Also, you are testing
> for modern Fortran (AC_PROG_FC) yet OPENMP_FFLAGS is for Fortan 77,
> which is probably not what you wanted.
> 
> Try this:
> 
>   AC_INIT([test], [0])
> 
>   AC_LANG([Fortran])
>   AC_PROG_FC
>   AC_OPENMP
> 
>   printf 'OPENMP_FCFLAGS = %s\n' "$OPENMP_FCFLAGS"
> 
>   AC_OUTPUT
> 
> Cheers,
>   Nick