guile: fix compilation with Guile < 2.0.4 (closes #198)

(cherry picked from commit 6a2bef6fb7f7f9a675d94230785cf644b2661644)

ChangeLog.asciidoc

@@ -28,6 +28,7 @@ http://weechat.org/files/releasenotes/ReleaseNotes-devel.html[release notes]
 * aspell: fix compilation with enchant version older than 1.6.0 (closes #192)
 * aspell: fix crash with command "/aspell addword" if no word is given
   (closes #164, closes #165)
+* guile: fix compilation with Guile < 2.0.4 (closes #198)
 * perl: fix detection of Perl >= 5.20 with autotools
 * script: fix crash on "/script update" if a script detail is displayed in
   buffer (closes #177)

cmake/FindGuile.cmake

@@ -34,4 +34,12 @@ endif()
 find_package(PkgConfig)
 if(PKG_CONFIG_FOUND)
   pkg_search_module(GUILE guile-2.0)
+  if(GUILE_FOUND)
+    # check if variable "scm_install_gmp_memory_functions" exists
+    set(CMAKE_REQUIRED_INCLUDES ${GUILE_INCLUDE_DIRS})
+    set(CMAKE_REQUIRED_LIBRARIES ${GUILE_LDFLAGS})
+    check_symbol_exists(scm_install_gmp_memory_functions "libguile.h" HAVE_GUILE_GMP_MEMORY_FUNCTIONS)
+    set(CMAKE_REQUIRED_INCLUDES)
+    set(CMAKE_REQUIRED_LIBRARIES)
+  endif()
 endif()

config.h.cmake

@@ -8,6 +8,7 @@
 #cmakedefine HAVE_EAT_NEWLINE_GLITCH
 #cmakedefine HAVE_ASPELL_VERSION_STRING
 #cmakedefine HAVE_ENCHANT_GET_VERSION
+#cmakedefine HAVE_GUILE_GMP_MEMORY_FUNCTIONS
 #define PACKAGE_VERSION "@VERSION@"
 #define PACKAGE "@PROJECT_NAME@"
 #define PACKAGE_NAME "@PROJECT_NAME@"

configure.ac

@@ -103,6 +103,7 @@ AH_VERBATIM([HAVE_FLOCK], [#undef HAVE_FLOCK])
 AH_VERBATIM([HAVE_EAT_NEWLINE_GLITCH], [#undef HAVE_EAT_NEWLINE_GLITCH])
 AH_VERBATIM([HAVE_ASPELL_VERSION_STRING], [#undef HAVE_ASPELL_VERSION_STRING])
 AH_VERBATIM([HAVE_ENCHANT_GET_VERSION], [#undef HAVE_ENCHANT_GET_VERSION])
+AH_VERBATIM([HAVE_GUILE_GMP_MEMORY_FUNCTIONS], [#undef HAVE_GUILE_GMP_MEMORY_FUNCTIONS])
 AH_VERBATIM([PLUGIN_ALIAS], [#undef PLUGIN_ALIAS])
 AH_VERBATIM([PLUGIN_ASPELL], [#undef PLUGIN_ASPELL])
 AH_VERBATIM([PLUGIN_CHARSET], [#undef PLUGIN_CHARSET])
@@ -814,7 +815,24 @@ if test "x$enable_guile" = "xyes" ; then
         fi
     done
 
-    if test "x$guile_found" = "xno" ; then
+    if test "x$guile_found" = "xyes" ; then
+        # check if variable "scm_install_gmp_memory_functions" exists
+        ac_save_CFLAGS="$CFLAGS"
+        ac_save_LDFLAGS="$LDFLAGS"
+        CFLAGS="$CFLAGS $GUILE_CFLAGS"
+        LDFLAGS="$LDFLAGS $GUILE_LFLAGS"
+        AC_CACHE_CHECK([for variable scm_install_gmp_memory_functions], ac_cv_have_guile_gmp_memory_functions, [
+        AC_LINK_IFELSE([AC_LANG_PROGRAM(
+            [[ #include <libguile.h>]],
+            [[ scm_install_gmp_memory_functions = 0; ]])],
+            [ ac_have_guile_gmp_memory_functions="yes" ],
+            [ ac_have_guile_gmp_memory_functions="no" ])])
+        CFLAGS="$ac_save_CFLAGS"
+        LDFLAGS="$ac_save_LDFLAGS"
+        if test "x$ac_have_guile_gmp_memory_functions" = "xyes"; then
+            AC_DEFINE(HAVE_GUILE_GMP_MEMORY_FUNCTIONS)
+        fi
+    else
         AC_MSG_WARN([
 *** Guile >= 2.0 couldn't be found on your system.
 *** WeeChat will be built without Guile (scheme) support.])

src/plugins/guile/weechat-guile.c

@@ -19,6 +19,10 @@
  * along with WeeChat.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #undef _
 
 #include <libguile.h>
@@ -971,12 +975,14 @@ weechat_plugin_init (struct t_weechat_plugin *plugin, int argc, char *argv[])
 
     guile_stdout = NULL;
 
+#ifdef HAVE_GUILE_GMP_MEMORY_FUNCTIONS
     /*
      * prevent guile to use its own gmp allocator, because it can conflict
      * with other plugins using GnuTLS like relay, which can crash WeeChat
      * on unload (or exit)
      */
     scm_install_gmp_memory_functions = 0;
+#endif
 
     scm_init_guile ();