Merge branch 'non_standard_fftw_path' into 'master'

Allow the user to specify a non-standard path for the FFTW library at configure time.

See merge request !534

configure.ac

@@ -444,6 +444,10 @@ if test "x$with_gsl" != "xno"; then
          AC_MSG_ERROR(something is wrong with the GSL library!), $GSL_LIBS)
       have_gsl="yes"
    fi
+   if test "$have_gsl" = "no"; then
+      GSL_LIBS=""
+      GSL_INCS=""
+   fi
 fi
 AC_SUBST([GSL_LIBS])
 AC_SUBST([GSL_INCS])
@@ -543,6 +547,45 @@ AC_SUBST([GRACKLE_LIBS])
 AC_SUBST([GRACKLE_INCS])
 AM_CONDITIONAL([HAVEGRACKLE],[test -n "$GRACKLE_LIBS"])
 
+# Check for FFTW. We test for this in the standard directories by default,
+# and only disable if using --with-fftw=no or --without-fftw. When a value
+# is given GSL must be found.
+have_fftw="no"
+AC_ARG_WITH([fftw],
+    [AS_HELP_STRING([--with-fftw=PATH],
+       [root directory where fftw is installed @<:@yes/no@:>@]
+    )],
+    [with_fftw="$withval"],
+    [with_fftw="test"]
+)
+if test "x$with_fftw" != "xno"; then
+   if test "x$with_fftw" != "xyes" -a "x$with_fftw" != "xtest" -a "x$with_fftw" != "x"; then
+      FFTW_LIBS="-L$with_fftw/lib -lfftw3"
+      FFTW_INCS="-I$with_fftw/include"
+   else
+      FFTW_LIBS="-lfftw3"
+      FFTW_INCS=""
+   fi
+   #  FFTW is not specified, so just check if we have it.
+   if test "x$with_fftw" = "xtest"; then
+      AC_CHECK_LIB([fftw3],[fftw_malloc],[have_fftw="yes"],[have_fftw="no"],$FFTW_LIBS)
+      if test "x$have_fftw" != "xno"; then
+      	 AC_DEFINE([HAVE_FFTW],1,[The FFTW library appears to be present.])
+      fi
+   else
+      AC_CHECK_LIB([fftw3],[fftw_malloc],
+         AC_DEFINE([HAVE_FFTW],1,[The FFTW library appears to be present.]),
+         AC_MSG_ERROR(something is wrong with the FFTW library!), $FFTW_LIBS)
+      have_fftw="yes"
+   fi      
+   if test "$have_fftw" = "no"; then
+      FFTW_LIBS=""
+      FFTW_INCS=""
+   fi
+fi
+AC_SUBST([FFTW_LIBS])
+AC_SUBST([FFTW_INCS])
+AM_CONDITIONAL([HAVEFFTW],[test -n "$FFTW_LIBS"])
 
 #  Check for tcmalloc a fast malloc that is part of the gperftools.
 have_tcmalloc="no"
@@ -704,16 +747,6 @@ if test "$ac_cv_func_pthread_setaffinity_np" = "yes"; then
   fi
 fi
 
-# Check for FFTW
-have_fftw3="no"
-AC_CHECK_HEADER([fftw3.h])
-if test "$ac_cv_header_fftw3_h" = "yes"; then
-   AC_CHECK_LIB([fftw3],[fftw_malloc], [AC_DEFINE([HAVE_FFTW],
-   [1],[Defined if FFTW 3.x exists.])] )
-   FFTW_LIBS="-lfftw3"
-   have_fftw3="yes"
-fi
-AC_SUBST([FFTW_LIBS])
 
 # Check for Intel and PowerPC intrinsics header optionally used by vector.h.
 AC_CHECK_HEADERS([immintrin.h])
@@ -1114,7 +1147,7 @@ AC_MSG_RESULT([
    HDF5 enabled     : $with_hdf5
     - parallel      : $have_parallel_hdf5
    Metis enabled    : $have_metis
-   FFTW3 enabled    : $have_fftw3
+   FFTW3 enabled    : $have_fftw
    GSL enabled      : $have_gsl
    libNUMA enabled  : $have_numa
    GRACKLE enabled  : $have_grackle

examples/Makefile.am

@@ -18,8 +18,8 @@
 # Common flags
 MYFLAGS = 
 
-# Add the source directory and debug to CFLAGS
-AM_CFLAGS = -I$(top_srcdir)/src $(HDF5_CPPFLAGS) $(GSL_INCS)
+# Add the source directory and the non-standard paths to the included library headers to CFLAGS
+AM_CFLAGS = -I$(top_srcdir)/src $(HDF5_CPPFLAGS) $(GSL_INCS) $(FFTW_INCS)
 
 AM_LDFLAGS = $(HDF5_LDFLAGS)
 

src/Makefile.am

@@ -15,8 +15,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Add the debug flag to the whole thing
-AM_CFLAGS = $(HDF5_CPPFLAGS) $(GSL_INCS)
+# Add the non-standard paths to the included library headers
+AM_CFLAGS = $(HDF5_CPPFLAGS) $(GSL_INCS) $(FFTW_INCS)
 
 # Assign a "safe" version number
 AM_LDFLAGS = $(HDF5_LDFLAGS) $(FFTW_LIBS) -version-info 0:0:0

tests/Makefile.am

@@ -14,8 +14,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Add the source directory and debug to CFLAGS
-AM_CFLAGS = -I$(top_srcdir)/src $(HDF5_CPPFLAGS) $(GSL_INCS)
+# Add the source directory and the non-standard paths to the included library headers to CFLAGS
+AM_CFLAGS = -I$(top_srcdir)/src $(HDF5_CPPFLAGS) $(GSL_INCS) $(FFTW_INCS)
 
 AM_LDFLAGS = ../src/.libs/libswiftsim.a $(HDF5_LDFLAGS) $(HDF5_LIBS) $(FFTW_LIBS) $(GRACKLE_LIBS) $(GSL_LIBS)