cmake: Detect constructor and destructor attributes

Signed-off-by: Andreas Schneider <asn@cryptomilk.org>

ConfigureChecks.cmake

@@ -272,6 +272,30 @@ int main(void) {
 # errors
 set(CMAKE_REQUIRED_FLAGS "-Werror")
 
+check_c_source_compiles("
+void test_constructor_attribute(void) __attribute__ ((constructor));
+
+void test_constructor_attribute(void)
+{
+    return;
+}
+
+int main(void) {
+    return 0;
+}" HAVE_CONSTRUCTOR_ATTRIBUTE)
+
+check_c_source_compiles("
+void test_destructor_attribute(void) __attribute__ ((destructor));
+
+void test_destructor_attribute(void)
+{
+    return;
+}
+
+int main(void) {
+    return 0;
+}" HAVE_DESTRUCTOR_ATTRIBUTE)
+
 check_c_source_compiles("
 #define FALL_THROUGH __attribute__((fallthrough))
 

config.h.cmake

@@ -193,6 +193,9 @@
 
 #cmakedefine HAVE_FALLTHROUGH_ATTRIBUTE 1
 
+#cmakedefine HAVE_CONSTRUCTOR_ATTRIBUTE 1
+#cmakedefine HAVE_DESTRUCTOR_ATTRIBUTE 1
+
 #cmakedefine HAVE_GCC_VOLATILE_MEMORY_PROTECTION 1
 #cmakedefine HAVE_GCC_NARG_MACRO 1