From 7c6ec620de3f99d4212f4a54aa576df1b97020ab Mon Sep 17 00:00:00 2001
From: Ondrej Kozina <okozina@redhat.com>
Date: Wed, 2 Feb 2022 11:34:57 +0100
Subject: [PATCH] Add check program for symver attribute.

Fixes: #709.
Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
---
 configure.ac               | 11 +++++++++++
 lib/libcryptsetup_symver.h |  8 +++-----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/configure.ac b/configure.ac
index a0e5990d..b052f8cf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -554,6 +554,17 @@ if test "x$enable_static_cryptsetup" = "xyes"; then
 	PKG_CONFIG=$saved_PKG_CONFIG
 fi
 
+dnl Check compiler support for symver function attribute
+saved_CFLAGS=$CFLAGS
+CFLAGS="-O0 -Werror"
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+	void _test_sym(void);
+	__attribute__((__symver__("sym@VERSION_4.2"))) void _test_sym(void) {}
+]],
+[[ _test_sym() ]]
+)],[ AC_DEFINE([HAVE_ATTRIBUTE_SYMVER], 1, [Define to 1 to use __attribute__((symver))])])
+CFLAGS=$saved_CFLAGS
+
 AC_MSG_CHECKING([for systemd tmpfiles config directory])
 PKG_CHECK_VAR([systemd_tmpfilesdir], [systemd], [tmpfilesdir], [], [systemd_tmpfilesdir=no])
 AC_MSG_RESULT([$systemd_tmpfilesdir])
diff --git a/lib/libcryptsetup_symver.h b/lib/libcryptsetup_symver.h
index 2a804b6a..3558310d 100644
--- a/lib/libcryptsetup_symver.h
+++ b/lib/libcryptsetup_symver.h
@@ -67,11 +67,9 @@
  *   under CRYPT_SYMBOL_EXPORT_OLD(int, crypt_func_X, ...) macro
  */
 
-#ifdef __has_attribute
-#  if __has_attribute(symver)
-#    define _CRYPT_SYMVER(_local_sym, _public_sym, _ver_str, _maj, _min)     \
-       __attribute__((__symver__(#_public_sym _ver_str #_maj "." #_min)))
-#  endif
+#if HAVE_ATTRIBUTE_SYMVER
+#  define _CRYPT_SYMVER(_local_sym, _public_sym, _ver_str, _maj, _min)     \
+     __attribute__((__symver__(#_public_sym _ver_str #_maj "." #_min)))
 #endif
 
 #if !defined(_CRYPT_SYMVER) && defined(__GNUC__)
-- 
2.25.1