basic/macros: rename noreturn into _noreturn_ (#8456)

"noreturn" is reserved and can be used in other header files we include:

  [   16s] In file included from /usr/include/gcrypt.h:30:0,
  [   16s]                  from ../src/journal/journal-file.h:26,
  [   16s]                  from ../src/journal/journal-vacuum.c:31:
  [   16s] /usr/include/gpg-error.h:1544:46: error: expected ‘,’ or ‘;’ before ‘)’ token
  [   16s]  void gpgrt_log_bug (const char *fmt, ...)    GPGRT_ATTR_NR_PRINTF(1,2);

Here we include grcrypt.h (which in turns include gpg-error.h) *after* we
"noreturn" was defined in macro.h.

src/basic/log.c

@@ -814,7 +814,7 @@ static void log_assert(
         log_dispatch_internal(level, 0, file, line, func, NULL, NULL, NULL, NULL, buffer);
 }
 
-noreturn void log_assert_failed_realm(
+_noreturn_ void log_assert_failed_realm(
                 LogRealm realm,
                 const char *text,
                 const char *file,
@@ -826,7 +826,7 @@ noreturn void log_assert_failed_realm(
         abort();
 }
 
-noreturn void log_assert_failed_unreachable_realm(
+_noreturn_ void log_assert_failed_unreachable_realm(
                 LogRealm realm,
                 const char *text,
                 const char *file,

src/basic/log.h

@@ -186,7 +186,7 @@ int log_dump_internal(
                 char *buffer);
 
 /* Logging for various assertions */
-noreturn void log_assert_failed_realm(
+_noreturn_ void log_assert_failed_realm(
                 LogRealm realm,
                 const char *text,
                 const char *file,
@@ -195,7 +195,7 @@ noreturn void log_assert_failed_realm(
 #define log_assert_failed(text, ...) \
         log_assert_failed_realm(LOG_REALM, (text), __VA_ARGS__)
 
-noreturn void log_assert_failed_unreachable_realm(
+_noreturn_ void log_assert_failed_unreachable_realm(
                 LogRealm realm,
                 const char *text,
                 const char *file,

src/basic/macro.h

@@ -53,6 +53,15 @@
 #else
 #define _fallthrough_
 #endif
+/* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
+ * compiler versions */
+#ifndef _noreturn_
+#if __STDC_VERSION__ >= 201112L
+#define _noreturn_ _Noreturn
+#else
+#define _noreturn_ __attribute__((noreturn))
+#endif
+#endif
 
 /* Temporarily disable some warnings */
 #define DISABLE_WARNING_DECLARATION_AFTER_STATEMENT                     \
@@ -414,16 +423,6 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) {
 #endif
 #endif
 
-/* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
- * compiler versions */
-#ifndef noreturn
-#if __STDC_VERSION__ >= 201112L
-#define noreturn _Noreturn
-#else
-#define noreturn __attribute__((noreturn))
-#endif
-#endif
-
 #define DEFINE_TRIVIAL_CLEANUP_FUNC(type, func)                 \
         static inline void func##p(type *p) {                   \
                 if (*p)                                         \

src/basic/process-util.c

@@ -987,7 +987,7 @@ bool is_main_thread(void) {
         return cached > 0;
 }
 
-noreturn void freeze(void) {
+_noreturn_ void freeze(void) {
 
         log_close();
 

src/basic/process-util.h

@@ -91,7 +91,7 @@ int pid_from_same_root_fs(pid_t pid);
 
 bool is_main_thread(void);
 
-noreturn void freeze(void);
+_noreturn_ void freeze(void);
 
 bool oom_score_adjust_is_valid(int oa);