Refactor __attribute__ usage

Use internal macros for compatibility with non GNUC compilers.

CRT.h

@@ -7,6 +7,8 @@ Released under the GNU GPL, see the COPYING file
 in the source distribution for its full text.
 */
 
+#include "Macros.h"
+
 #include <stdbool.h>
 
 #define KEY_WHEELUP   KEY_F(20)
@@ -107,7 +109,7 @@ typedef enum ColorElements_ {
    LAST_COLORELEMENT
 } ColorElements;
 
-void CRT_fatalError(const char* note) __attribute__ ((noreturn));
+void CRT_fatalError(const char* note) ATTR_NORETURN;
 
 extern struct sigaction old_sigsegv_handler;
 void CRT_handleSIGSEGV(int sgn);

Macros.h

@@ -13,4 +13,20 @@
 #define CLAMP(x, low, high)	(((x) > (high)) ? (high) : MAXIMUM(x, low))
 #endif
 
+#ifdef  __GNUC__  // defined by GCC and Clang
+
+#define ATTR_FORMAT(type, index, check) __attribute__((format (type, index, check)))
+#define ATTR_NONNULL                    __attribute__((nonnull))
+#define ATTR_NORETURN                   __attribute__((noreturn))
+#define ATTR_UNUSED                     __attribute__((unused))
+
+#else /* __GNUC__ */
+
+#define ATTR_FORMAT(type, index, check)
+#define ATTR_NONNULL
+#define ATTR_NORETURN
+#define ATTR_UNUSED
+
+#endif /* __GNUC__ */
+
 #endif

XAlloc.c

@@ -53,14 +53,6 @@ void* xRealloc(void* ptr, size_t size) {
 # define xStrdup(str_) (assert(str_), xStrdup_(str_))
 #endif
 
-#ifndef __has_attribute // Clang's macro
-# define __has_attribute(x) 0
-#endif
-#if (__has_attribute(nonnull) || \
-    ((__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)))
-char* xStrdup_(const char* str) __attribute__((nonnull));
-#endif // __has_attribute(nonnull) || GNU C 3.3 or later
-
 char* xStrdup_(const char* str) {
    char* data = strdup(str);
    if (!data) {

XAlloc.h

@@ -31,14 +31,6 @@ void* xRealloc(void* ptr, size_t size);
 # define xStrdup(str_) (assert(str_), xStrdup_(str_))
 #endif
 
-#ifndef __has_attribute // Clang's macro
-# define __has_attribute(x) 0
-#endif
-#if (__has_attribute(nonnull) || \
-    ((__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)))
-char* xStrdup_(const char* str) __attribute__((nonnull));
-#endif // __has_attribute(nonnull) || GNU C 3.3 or later
-
-char* xStrdup_(const char* str);
+char* xStrdup_(const char* str) ATTR_NONNULL;
 
 #endif

dragonflybsd/DragonFlyBSDProcessList.c

@@ -22,8 +22,6 @@ in the source distribution for its full text.
 #include <sys/param.h>
 
 
-#define _UNUSED_ __attribute__((unused))
-
 static int MIB_hw_physmem[2];
 static int MIB_vm_stats_vm_v_page_count[4];
 static int pageSize;
@@ -377,7 +375,7 @@ void ProcessList_goThroughEntries(ProcessList* this) {
    for (int i = 0; i < count; i++) {
       struct kinfo_proc* kproc = &kprocs[i];
       bool preExisting = false;
-      bool _UNUSED_ isIdleProcess = false;
+      bool ATTR_UNUSED isIdleProcess = false;
 
       // note: dragonflybsd kernel processes all have the same pid, so we misuse the kernel thread address to give them a unique identifier
       Process* proc = ProcessList_getProcess(this, kproc->kp_ktaddr ? (pid_t)kproc->kp_ktaddr : kproc->kp_pid, &preExisting, (Process_New) DragonFlyBSDProcess_new);

dragonflybsd/DragonFlyBSDProcessList.h

@@ -51,8 +51,6 @@ typedef struct DragonFlyBSDProcessList_ {
    Hashtable *jails;
 } DragonFlyBSDProcessList;
 
-#define _UNUSED_ __attribute__((unused))
-
 ProcessList* ProcessList_new(UsersTable* usersTable, Hashtable* pidMatchList, uid_t userId);
 
 void ProcessList_delete(ProcessList* this);

zfs/ZfsArcStats.c

@@ -21,4 +21,6 @@ typedef struct ZfsArcStats_ {
 } ZfsArcStats;
 }*/
 
-static int make_iso_compilers_happy __attribute__((unused));
+#include "Macros.h"
+
+static int make_iso_compilers_happy ATTR_UNUSED;