Added symbol visibility features to the build to hide internal symbols (GCC)

1 files changed, 92 insertions, 0 deletions

diff --git a/configure b/configure
index c108720..ebc1661 100755
--- a/configure
+++ b/configure
@@ -646,6 +646,9 @@ LFS_FLAG
 V6_FLAG
 OPENSSL_LIBS
 HTTPS_SUPPORT
+AM_CFLAGS
+HAVE_VISIBILITY
+CFLAG_VISIBILITY
 VERSION_INFO
 DEFAULT_CFLAGS
 LT_CV_OBJDIR
@@ -15317,6 +15320,95 @@ DEFAULT_CFLAGS="-Wall -Wcast-align -Wstrict-prototypes \
 
 
 
+### Check for -fvisibility=hidden support
+
+
+  CFLAG_VISIBILITY=
+  HAVE_VISIBILITY=0
+  if test -n "$GCC"; then
+                { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the -Werror option is usable" >&5
+$as_echo_n "checking whether the -Werror option is usable... " >&6; }
+    if ${gl_cv_cc_vis_werror+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+      gl_save_CFLAGS="$CFLAGS"
+      CFLAGS="$CFLAGS -Werror"
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  gl_cv_cc_vis_werror=yes
+else
+  gl_cv_cc_vis_werror=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+      CFLAGS="$gl_save_CFLAGS"
+fi
+
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_cc_vis_werror" >&5
+$as_echo "$gl_cv_cc_vis_werror" >&6; }
+        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for simple visibility declarations" >&5
+$as_echo_n "checking for simple visibility declarations... " >&6; }
+    if ${gl_cv_cc_visibility+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+
+      gl_save_CFLAGS="$CFLAGS"
+      CFLAGS="$CFLAGS -fvisibility=hidden"
+                                    if test $gl_cv_cc_vis_werror = yes; then
+        CFLAGS="$CFLAGS -Werror"
+      fi
+      cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+extern __attribute__((__visibility__("hidden"))) int hiddenvar;
+         extern __attribute__((__visibility__("default"))) int exportedvar;
+         extern __attribute__((__visibility__("hidden"))) int hiddenfunc (void);
+         extern __attribute__((__visibility__("default"))) int exportedfunc (void);
+         void dummyfunc (void) {}
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  gl_cv_cc_visibility=yes
+else
+  gl_cv_cc_visibility=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+      CFLAGS="$gl_save_CFLAGS"
+fi
+
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: $gl_cv_cc_visibility" >&5
+$as_echo "$gl_cv_cc_visibility" >&6; }
+    if test $gl_cv_cc_visibility = yes; then
+      CFLAG_VISIBILITY="-fvisibility=hidden"
+      HAVE_VISIBILITY=1
+    fi
+  fi
+
+
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_VISIBILITY $HAVE_VISIBILITY
+_ACEOF
+
+
+AM_CFLAGS="$AM_CFLAGS $CFLAG_VISIBILITY"
+
+
 ### Check for platform
 #case $host in
 #AIX) AC_DEFINE(HTS_PLATFORM, 1, [Defined to build under AIX]);;