Add detection of visibility attribute at configuration time

On SunOS the linker does not support the visibility attribute.

Reported-by: Uli Schlachter <psychon@znc.in>

3 files changed, 77 insertions, 1 deletions

diff --git a/compiler/simpleops-compiler-types.h b/compiler/simpleops-compiler-types.h
index 3507e42..7a6348c 100644
--- a/compiler/simpleops-compiler-types.h
+++ b/compiler/simpleops-compiler-types.h
@@ -143,7 +143,10 @@ typedef int simpleops_bool_t;
 #define _simpleops_import __declspec(dllimport)
 #define _simpleops_export __declspec(dllexport)
 #define simpleops_private
-#elif defined(__GNUC__) && (((__GNUC__ == 3) && (__GNUC_MINOR__ >= 3)) || (__GNUC__ > 3))
+#elif defined(__GNUC__) && \
+    (((__GNUC__ == 3) && (__GNUC_MINOR__ >= 3)) || (__GNUC__ > 3)) && \
+    defined (SIMPLEOPS_HAVE_ATTRIBUTE_VISIBILITY_DEFAULT) && \
+    defined (SIMPLEOPS_HAVE_ATTRIBUTE_VISIBILITY_HIDDEN)
 #define _simpleops_import extern
 #define _simpleops_export __attribute__((__visibility__("default")))
 #define simpleops_private __attribute__((__visibility__("hidden")))
diff --git a/m4/ax_c___attribute__visibility.m4 b/m4/ax_c___attribute__visibility.m4
new file mode 100644
index 0000000..2f49bbc
--- /dev/null
+++ b/m4/ax_c___attribute__visibility.m4
@@ -0,0 +1,71 @@
+# ===========================================================================
+#    http://www.gnu.org/software/autoconf-archive/ax_c___attribute__.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_C___ATTRIBUTE__VISIBILITY(VISIBILITY-TYPE)
+#
+# DESCRIPTION
+#
+#   Provides a test for the compiler support of the
+#   __attribute__((__visibility__("VISIBILITY-TYPE"))) extension.
+#   Defines HAVE_ATTRIBUTE_VISIBILITY_<VISIBILITY_TYPE> if it is
+#   found.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Stepan Kasal <skasal@redhat.com>
+#   Copyright (c) 2008 Christian Haggstrom
+#   Copyright (c) 2008 Ryan McCabe <ryan@numb.org>
+#   Copyright (c) 2011 Andrea Canciani <ranma42@gmail.com>
+#
+#   This program is free software; you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation; either version 2 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 11
+
+AC_DEFUN([AX_C_ATTRIBUTE_VISIBILITY], [
+  AC_CACHE_CHECK([for __attribute__((__visibility__("$1")))], [ax_cv_attribute_visibility_$1],
+    [AX_NODIFF_COMPILE_IFELSE(
+      [AC_LANG_PROGRAM(
+	[[
+void foo (void);
+void foo (void) { return; }
+        ]], [[foo ()]])],
+      [AC_LANG_PROGRAM(
+	[[
+void foo (void) __attribute__ ((__visibility__("$1")));
+void foo (void) { return; }
+        ]], [[foo ()]])],
+      [ax_cv_attribute_visibility_$1=yes],
+      [ax_cv_attribute_visibility_$1=no]
+    )
+  ])
+  if test "$ax_cv_attribute_visibility_$1" = "yes"; then
+    AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_ATTRIBUTE_VISIBILITY_$1]), 1, [Define to 1 if your compiler has __attribute__((__visibility__("$1"))).])
+  fi
+])
diff --git a/m4/simpleops_compiler.m4 b/m4/simpleops_compiler.m4
index 8ae12a5..65b8371 100644
--- a/m4/simpleops_compiler.m4
+++ b/m4/simpleops_compiler.m4
@@ -5,4 +5,6 @@ AC_DEFUN([SIMPLEOPS_CHECK_COMPILER],
 	AX_C_ATTRIBUTE([const])
 	AX_C_ATTRIBUTE([noinline])
 	AX_C_ATTRIBUTE([pure])
+	AX_C_ATTRIBUTE_VISIBILITY([default])
+	AX_C_ATTRIBUTE_VISIBILITY([hidden])
 ])