[gnuastro-commits] master 5ad88be 2/2: Informative message when mandatory dependency is missing

[Mohammad Akhlaghi]

branch: master
commit 5ad88bedc82e831fdeb10c56e4bb99525fb4a959
Author: Mohammad Akhlaghi <address@hidden>
Commit: Mohammad Akhlaghi <address@hidden>

    Informative message when mandatory dependency is missing
    
    Until now, when a mandatory dependency was missing, there was only a
    single-line message which was hard to interpret for new users (especially
    people who aren't familiar with the libraries or haven't read the manual
    yet). The message would also abort the configure script, so it wasn't
    possible to see what other mandatory dependency we are missing.
    
    Since many questions were asked about what the single-line error messages
    are, and how to fix them, a more informative message is now printed. It
    also lists all the dependencies in one run of `./configure'.
---
 configure.ac | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 75 insertions(+), 13 deletions(-)

diff --git a/configure.ac b/configure.ac
index 771ca77..19c2d1b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -254,17 +254,19 @@ AC_MSG_RESULT( $path_warning )
 # checking the next libraries, so the linking with their dependent
 # libraries is done automatically with this order, and we don't have to
 # explicitly set the dependency flags.
+has_gsl=yes
+has_cmath=yes
+has_wcslib=yes
+has_cfitsio=yes
+has_gslcblas=yes
+missing_mandatory=no
+missing_optional_lib=no
 AC_SEARCH_LIBS(sqrt, m, [],
-    [AC_MSG_ERROR([C math library not present, cannot continue.])])
+               [missing_mandatory=yes; has_cmath=no])
 AC_SEARCH_LIBS([cblas_sdsdot], [gslcblas], [],
-    [AC_MSG_ERROR([GSL CBLAS not present, cannot continue.])])
+               [missing_mandatory=yes; has_gslcblas=no])
 AC_SEARCH_LIBS([gsl_integration_qng], [gsl], [],
-    [AC_MSG_ERROR([GSL not found, cannot continue.])])
-AC_CHECK_DECLS(gsl_interp_steffen,
-               [ gsl_version_old=no                   ],
-               [ gsl_version_old=yes; anywarnings=yes ],
-               [[#include <gsl/gsl_interp.h>]])
-
+               [missing_mandatory=yes; has_gsl=no])
 
 # Since version 0.42, if `libcurl' is installed, CFITSIO will link with it
 # and thus it will be necessary to explicitly link with libcurl also. If it
@@ -273,9 +275,57 @@ AC_CHECK_DECLS(gsl_interp_steffen,
 # script if libcurl isn't found.
 AC_SEARCH_LIBS([curl_global_init], [curl], [], [])
 AC_SEARCH_LIBS([ffopen], [cfitsio], [],
-    [AC_MSG_ERROR([CFITSIO not found, cannot continue.])])
+               [missing_mandatory=yes; has_cfitsio=no])
 AC_SEARCH_LIBS([wcspih], [wcs], [],
-    [AC_MSG_ERROR([WCSLIB not found, cannot continue.])])
+               [missing_mandatory=yes; has_wcslib=no])
+
+
+
+
+
+# If any necessary dependency is missing inform the user and abort.
+AS_IF([test "x$missing_mandatory" = "xyes"],
+      [
+        # Introduction.
+        AS_ECHO([""])
+        AS_ECHO(["The configure script couldn't link with the following 
mandatory dependency(s):"])
+
+        # List missing packages: print the GSL CBLAS message only if GSL is
+        # present. Otherwise, it is just confusing for the users (CBLAS
+        # will be installed with GSL). The CBLAS message is only
+        # interesting if the GSL test has passed.
+        AS_ECHO([""])
+        AS_IF([test "x$has_cmath" = "xno"],
+              [ AS_ECHO([" - C library (math): This may be the cause of all 
other failures."]) ])
+        AS_IF([test "x$has_gsl" = "xno"],
+              [ AS_ECHO([" - GNU Scientific Library (GSL): 
https://www.gnu.org/software/gsl";]) ],
+              [ AS_IF([test "x$has_gslcblas" = "xno"],
+                      [ AS_ECHO([" - The BLAS support of GNU Scientific 
Library (GSL). This should have"])
+                        AS_ECHO(["   been installed along with GSL. Try 
re-installing GSL."]) ]) ])
+        AS_IF([test "x$has_cfitsio" = "xno"],
+              [ AS_ECHO([" - CFITSIO: https://heasarc.gsfc.nasa.gov/fitsio";]) 
])
+        AS_IF([test "x$has_wcslib" = "xno"],
+              [ AS_ECHO([" - WCSLIB: 
http://www.atnf.csiro.au/people/mcalabre/WCS";]) ])
+
+        # Suggestions on fixing the problem.
+        AS_ECHO([""])
+        AS_ECHO(["You can use your package manager for easy and fast 
installation of all the"])
+        AS_ECHO(["mandatory and optional dependencies in one command. See the 
link below:"])
+        AS_ECHO(["  
https://www.gnu.org/software/gnuastro/manual/html_node/Dependencies-from-package-managers.html";])
+        AS_ECHO([""])
+        AS_ECHO(["If you have already installed a dependency (for example in 
\`/install/path'),"])
+        AS_ECHO(["but this script can't link with it, add the path to the 
LDFLAGS, CPPFLAGS and"])
+        AS_ECHO(["LD_LIBRARY_PATH environment variables before running 
configure. For example"])
+        AS_ECHO(["with the following commands (just correct the 
\`/install/path' part)."])
+        AS_ECHO(["  $ export LDFLAGS=\"\$LDFLAGS -L/install/path/lib\""])
+        AS_ECHO(["  $ export CPPFLAGS=\"\$CPPFLAGS -L/install/path/include\""])
+        AS_ECHO(["  $ export 
LD_LIBRARY_PATH=\"\$LD_LIBRARY_PATH:/install/path/lib\""])
+        AS_ECHO(["[TIP] Put these commands in your startup file (for example 
\`~/.bashrc') to"])
+        AS_ECHO(["avoid similar problems later. See the link below to learn 
more:"])
+        AS_ECHO(["  
https://www.gnu.org/software/gnuastro/manual/html_node/Installation-directory.html";])
+        AS_ECHO([""])
+        AC_MSG_ERROR([Mandatory dependency(s) missing, see above.])
+      ])
 
 
 
@@ -284,6 +334,10 @@ AC_SEARCH_LIBS([wcspih], [wcs], [],
 # These are secondary tests for more fine-grained control in libraries that
 # have already been checked. We don't need to add them to the LIBS
 # variable, so we are using AC_CHECK_LIB for these tests.
+AC_CHECK_DECLS(gsl_interp_steffen,
+               [ gsl_version_old=no                   ],
+               [ gsl_version_old=yes; anywarnings=yes ],
+               [[#include <gsl/gsl_interp.h>]])
 
 # If the CFITSIO library has the `fits_is_reentrant' function (it was added
 # since version 3.30 of April 2012).
@@ -324,7 +378,7 @@ AM_CONDITIONAL([COND_HASHELP2MAN], [test "x$has_help2man" = 
"xyes"])
 
 # Check libjpeg:
 AC_SEARCH_LIBS([jpeg_stdio_dest], [jpeg],
-               [has_libjpeg=yes], [has_libjpeg=no])
+               [has_libjpeg=yes], [has_libjpeg=no; missing_optional_lib=yes])
 AS_IF([test "x$has_libjpeg" = "xyes"],
       [AC_DEFINE([HAVE_LIBJPEG], [], [Has libjpeg])],
       [anywarnings=yes])
@@ -336,7 +390,7 @@ AM_CONDITIONAL([COND_HASLIBJPEG], [test "x$has_libjpeg" = 
"xyes"])
 
 # Check libtiff:
 AC_SEARCH_LIBS([TIFFOpen], [tiff],
-               [has_libtiff=yes], [has_libtiff=no])
+               [has_libtiff=yes], [has_libtiff=no; missing_optional_lib=yes])
 AS_IF([test "x$has_libtiff" = "xyes"],
       [AC_DEFINE([HAVE_LIBTIFF], [], [Has libtiff])],
       [anywarnings=yes])
@@ -348,7 +402,7 @@ AM_CONDITIONAL([COND_HASLIBTIFF], [test "x$has_libtiff" = 
"xyes"])
 
 # Check libgit2:
 AC_SEARCH_LIBS([git_libgit2_init], [git2],
-               [has_libgit2=1], [has_libgit2=0])
+               [has_libgit2=1], [has_libgit2=0; missing_optional_lib=yes])
 AC_DEFINE_UNQUOTED([GAL_CONFIG_HAVE_LIBGIT2], [$has_libgit2],
                    [libgit2 is installed on the system])
 AS_IF([test "x$has_libgit2" = "x1"], [], [anywarnings=yes])
@@ -843,6 +897,14 @@ AS_IF([test x$enable_guide_message = xyes],
                AS_ECHO(["        $ info gnuastro \"Installation directory\""])
                AS_ECHO([]) ])
 
+        # Notice on obtaining all the packages.
+        AS_ECHO(["  You can use your package manager for easy and fast 
installation of all"])
+        AS_ECHO(["  the mandatory and optional dependencies in one command. 
See the link"])
+        AS_ECHO(["  below:"])
+        AS_ECHO(["    
https://www.gnu.org/software/gnuastro/manual/html_node/Dependencies-from-package-managers.html";])
+        AS_ECHO([])
+
+        # Inform the user on skipped tests.
         AS_ECHO(["  All checks related to the warning(s) above will be 
skipped."])
         AS_ECHO([])
       ]