Correctly detect the GSL and print its version in the greetings.

configure.ac

@@ -404,6 +404,10 @@ AC_HEADER_STDC
 # Check for the libraries we will need.
 AC_CHECK_LIB(m,sqrt,,AC_MSG_ERROR(something is wrong with the math library!))
 
+# Check for GSL
+AC_CHECK_LIB([gslcblas],[cblas_dgemm])
+AC_CHECK_LIB([gsl],[gsl_blas_dgemm])
+
 # Check for pthreads.
 AX_PTHREAD([LIBS="$PTHREAD_LIBS $LIBS" CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
     CC="$PTHREAD_CC" LDFLAGS="$LDFLAGS $PTHREAD_LIBS $LIBS"],

src/common_io.c

@@ -395,6 +395,9 @@ void io_write_code_description(hid_t h_file) {
 #ifdef HAVE_FFTW
   io_write_attribute_s(h_grpcode, "FFTW library version", fftw3_version());
 #endif
+#ifdef HAVE_LIBGSL
+  io_write_attribute_s(h_grpcode, "GSL library version", libgsl_version());
+#endif
 #ifdef WITH_MPI
   io_write_attribute_s(h_grpcode, "MPI library", mpi_version());
 #ifdef HAVE_METIS

src/version.c

@@ -37,6 +37,10 @@
 #include <fftw3.h>
 #endif
 
+#ifdef HAVE_LIBGSL
+#include <gsl/gsl_version.h>
+#endif
+
 /* Some standard headers. */
 #include <stdio.h>
 #include <stdlib.h>
@@ -332,6 +336,22 @@ const char *fftw3_version(void) {
   return version;
 }
 
+/**
+ * @brief return the GSL version used when SWIFT was built.
+ *
+ * @result description of the GSL version.
+ */
+const char *libgsl_version(void) {
+
+  static char version[256] = {0};
+#if defined(HAVE_LIBGSL)
+  sprintf(version, "%s", gsl_version);
+#else
+  sprintf(version, "Unknown version");
+#endif
+  return version;
+}
+
 /**
  * @brief return the thread barrier used in SWIFT.
  *
@@ -376,6 +396,9 @@ void greetings(void) {
 #ifdef HAVE_FFTW
   printf(" FFTW library version: %s\n", fftw3_version());
 #endif
+#ifdef HAVE_LIBGSL
+  printf(" GSL library version: %s\n", libgsl_version());
+#endif
 #ifdef WITH_MPI
   printf(" MPI library: %s\n", mpi_version());
 #ifdef HAVE_METIS

src/version.h

@@ -34,6 +34,7 @@ const char* mpi_version(void);
 const char* metis_version(void);
 const char* hdf5_version(void);
 const char* fftw3_version(void);
+const char* libgsl_version(void);
 const char* thread_barrier_version(void);
 void greetings(void);