build: add checks for -rdynamic linker flag support

Signed-off-by: Ar Rakin <rakinar2@onesoftnet.eu.org>

Author: virtual-designer

configure.ac

@@ -139,13 +139,9 @@ LT_INIT
 
 # Checks for libraries.
 
-case "$host_os" in
-  darwin*) shared_library_ext="dylib" ;;
-  cygwin*|mingw*) shared_library_ext="dll" ;;
-  *) shared_library_ext="so" ;;
-esac
-
-AC_DEFINE_UNQUOTED([SHARED_LIBRARY_EXTENSION], ["$shared_library_ext"], [The extension shared libraries use on this platform])
+AC_CHECK_LIB([dl], [dlopen], [have_libdl=yes], [
+    AC_MSG_ERROR([libdl is required for loading dynamic modules])
+])
 
 FEATURE_SYSTEMD_SUPPORT_CHECK
 FEATURE_RAPIDHASH_CHECK
@@ -157,13 +153,21 @@ AC_SUBST([ABS_SRCDIR])
 AC_SUBST([ABS_BUILDDIR])
 
 # Define macros
+case "$host_os" in
+  darwin*) shared_library_ext="dylib" ;;
+  cygwin*|mingw*) shared_library_ext="dll" ;;
+  *) shared_library_ext="so" ;;
+esac
+
+AC_DEFINE_UNQUOTED([SHARED_LIBRARY_EXTENSION], ["$shared_library_ext"], [The extension shared libraries use on this platform])
 
 # Checks for header files.
 AC_CHECK_HEADERS([arpa/inet.h fcntl.h netdb.h netinet/in.h sys/socket.h sys/time.h])
 AC_CHECK_HEADERS([stdnoreturn.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
-STDC_CHECK_VLA_SUPPORT
+CC_CHECK_VLA_SUPPORT
+CCLD_CHECK_RDYNAMIC_SUPPORT
 
 AC_CHECK_HEADER_STDBOOL
 AC_TYPE_OFF_T
@@ -188,10 +192,6 @@ AC_FUNC_STRTOD
 AC_CHECK_FUNCS([atexit clock_gettime gettimeofday memchr memmove memset socket strcasecmp strdup strerror strndup strrchr strtoull])
 AC_CHECK_FUNCS([realpath strchr strncasecmp strtoul getopt_long])
 
-AC_CHECK_LIB([dl], [dlopen], [have_libdl=yes], [
-    AC_MSG_ERROR([libdl is required for loading dynamic modules])
-])
-
 # Enable modules
 m4_foreach([name], [AVAILABLE_MODULES], [
     AM_CONDITIONAL([ENABLE_MOD_]m4_toupper(name), [test "x$enable_mod_]name[" = "xyes" || test "x$enable_mod_all" = "xyes"])

m4/compiler.m4

@@ -1,4 +1,6 @@
-AC_DEFUN([STDC_CHECK_VLA_SUPPORT], [
+#                                -*- Autoconf -*-
+
+AC_DEFUN([CC_CHECK_VLA_SUPPORT], [
     AC_MSG_CHECKING([whether $CC supports VLAs])
 
     AC_COMPILE_IFELSE(
@@ -16,3 +18,28 @@ AC_DEFUN([STDC_CHECK_VLA_SUPPORT], [
         ]
     )
 ])
+
+AC_DEFUN([CCLD_CHECK_RDYNAMIC_SUPPORT], [
+	AC_MSG_CHECKING([whether $LD supports -rdynamic])
+
+	prev_ldflags="$LDFLAGS"
+	LDFLAGS="$LDFLAGS -rdynamic"
+
+	AC_LINK_IFELSE(
+		[AC_LANG_PROGRAM(
+			[[
+				#include <stdio.h>
+			]],
+			[[
+				puts ("Hello world");
+			]]
+		)],
+		[AC_MSG_RESULT([yes])],
+		[
+			AC_MSG_RESULT([no])
+			AC_MSG_ERROR([The linker $LD does not support -rdynamic])
+		]
+	)
+
+	LDFLAGS="$prev_ldflags"
+])