From f58ed932d80a85e1022c625892f0f2081589a408 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ayd=C4=B1n=20Mercan?= <aydin@isc.org>
Date: Thu, 11 Jul 2024 16:15:40 +0300
Subject: [PATCH] use only c23 or c11 noreturn specifiers

Since we require C11 or greater, we can depend on using either _Noreturn
or [[noreturn]].
---
 bin/check/named-checkconf.c      | 2 +-
 bin/check/named-checkzone.c      | 2 +-
 bin/confgen/rndc-confgen.c       | 2 +-
 bin/confgen/tsig-keygen.c        | 2 +-
 bin/confgen/util.h               | 2 +-
 bin/delv/delv.c                  | 2 +-
 bin/dig/dig.c                    | 2 +-
 bin/dig/dighost.h                | 4 ++--
 bin/dig/host.c                   | 2 +-
 bin/dig/nslookup.c               | 2 +-
 bin/dnssec/dnssec-cds.c          | 2 +-
 bin/dnssec/dnssec-dsfromkey.c    | 2 +-
 bin/dnssec/dnssec-importkey.c    | 2 +-
 bin/dnssec/dnssec-keyfromlabel.c | 2 +-
 bin/dnssec/dnssec-keygen.c       | 2 +-
 bin/dnssec/dnssec-revoke.c       | 2 +-
 bin/dnssec/dnssec-settime.c      | 2 +-
 bin/dnssec/dnssec-signzone.c     | 2 +-
 bin/dnssec/dnssec-verify.c       | 2 +-
 bin/dnssec/dnssectool.h          | 4 ++--
 bin/named/include/named/main.h   | 2 +-
 bin/named/main.c                 | 4 ++--
 bin/named/server.c               | 2 +-
 bin/nsupdate/nsupdate.c          | 2 +-
 bin/rndc/rndc.c                  | 2 +-
 bin/rndc/util.h                  | 2 +-
 bin/tools/dnstap-read.c          | 2 +-
 bin/tools/mdig.c                 | 4 ++--
 bin/tools/named-rrchecker.c      | 4 ++--
 bin/tools/nsec3hash.c            | 2 +-
 configure.ac                     | 9 ---------
 lib/isc/include/isc/assertions.h | 2 +-
 lib/isc/include/isc/attributes.h | 8 +++-----
 lib/isc/include/isc/error.h      | 2 +-
 34 files changed, 40 insertions(+), 51 deletions(-)

diff --git a/bin/check/named-checkconf.c b/bin/check/named-checkconf.c
index 00335b6089..70b4b317ba 100644
--- a/bin/check/named-checkconf.c
+++ b/bin/check/named-checkconf.c
@@ -54,7 +54,7 @@ isc_log_t *logc = NULL;
 	} while (0)
 
 /*% usage */
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/check/named-checkzone.c b/bin/check/named-checkzone.c
index db2e345561..a0ddf8a94b 100644
--- a/bin/check/named-checkzone.c
+++ b/bin/check/named-checkzone.c
@@ -62,7 +62,7 @@ static enum { progmode_check, progmode_compile } progmode;
 		}                                                             \
 	} while (0)
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/confgen/rndc-confgen.c b/bin/confgen/rndc-confgen.c
index c840e2c284..f96ee47d20 100644
--- a/bin/confgen/rndc-confgen.c
+++ b/bin/confgen/rndc-confgen.c
@@ -60,7 +60,7 @@ bool verbose = false;
 
 const char *keyfile, *keydef;
 
-noreturn static void
+ISC_NORETURN static void
 usage(int status);
 
 static void
diff --git a/bin/confgen/tsig-keygen.c b/bin/confgen/tsig-keygen.c
index c421702c8b..39f13a73fc 100644
--- a/bin/confgen/tsig-keygen.c
+++ b/bin/confgen/tsig-keygen.c
@@ -53,7 +53,7 @@ const char *progname;
 static enum { progmode_keygen, progmode_confgen } progmode;
 bool verbose = false; /* needed by util.c but not used here */
 
-noreturn static void
+ISC_NORETURN static void
 usage(int status);
 
 static void
diff --git a/bin/confgen/util.h b/bin/confgen/util.h
index 4ac83e5143..0567ad33b1 100644
--- a/bin/confgen/util.h
+++ b/bin/confgen/util.h
@@ -36,7 +36,7 @@ ISC_LANG_BEGINDECLS
 void
 notify(const char *fmt, ...) ISC_FORMAT_PRINTF(1, 2);
 
-noreturn void
+ISC_NORETURN void
 fatal(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);
 
 ISC_LANG_ENDDECLS
diff --git a/bin/delv/delv.c b/bin/delv/delv.c
index 36f26f042c..d494500675 100644
--- a/bin/delv/delv.c
+++ b/bin/delv/delv.c
@@ -250,7 +250,7 @@ usage(void) {
 	exit(EXIT_FAILURE);
 }
 
-noreturn static void
+ISC_NORETURN static void
 fatal(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);
 
 static void
diff --git a/bin/dig/dig.c b/bin/dig/dig.c
index e9665c9e01..288b327ef2 100644
--- a/bin/dig/dig.c
+++ b/bin/dig/dig.c
@@ -111,7 +111,7 @@ usage(void) {
 	fprintf(stderr, "Press <Help> for complete list of options\n");
 }
 #else  /* if TARGET_OS_IPHONE */
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/dig/dighost.h b/bin/dig/dighost.h
index 99c0c3c864..56842f9419 100644
--- a/bin/dig/dighost.h
+++ b/bin/dig/dighost.h
@@ -293,13 +293,13 @@ getaddresses(dig_lookup_t *lookup, const char *host, isc_result_t *resultp);
 isc_result_t
 get_reverse(char *reverse, size_t len, char *value, bool strict);
 
-noreturn void
+ISC_NORETURN void
 fatal(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);
 
 void
 warn(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);
 
-noreturn void
+ISC_NORETURN void
 digexit(void);
 
 void
diff --git a/bin/dig/host.c b/bin/dig/host.c
index 6710c981f1..a44acde55c 100644
--- a/bin/dig/host.c
+++ b/bin/dig/host.c
@@ -99,7 +99,7 @@ rcode_totext(dns_rcode_t rcode) {
 	return (totext.deconsttext);
 }
 
-noreturn static void
+ISC_NORETURN static void
 show_usage(void);
 
 static void
diff --git a/bin/dig/nslookup.c b/bin/dig/nslookup.c
index 4b813511b7..2c89243751 100644
--- a/bin/dig/nslookup.c
+++ b/bin/dig/nslookup.c
@@ -836,7 +836,7 @@ fgets_next_command(void *arg) {
 	cmdline = fgets(cmdlinebuf, COMMSIZE, stdin);
 }
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/dnssec/dnssec-cds.c b/bin/dnssec/dnssec-cds.c
index fd877160d8..86aeff0b11 100644
--- a/bin/dnssec/dnssec-cds.c
+++ b/bin/dnssec/dnssec-cds.c
@@ -1028,7 +1028,7 @@ nsdiff(uint32_t ttl, dns_rdataset_t *oldset, dns_rdataset_t *newset) {
 	}
 }
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/dnssec/dnssec-dsfromkey.c b/bin/dnssec/dnssec-dsfromkey.c
index 466f7ce0fe..97f2a3780d 100644
--- a/bin/dnssec/dnssec-dsfromkey.c
+++ b/bin/dnssec/dnssec-dsfromkey.c
@@ -324,7 +324,7 @@ emits(bool showall, bool cds, dns_rdata_t *rdata) {
 	}
 }
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/dnssec/dnssec-importkey.c b/bin/dnssec/dnssec-importkey.c
index 3bb4029052..165707d553 100644
--- a/bin/dnssec/dnssec-importkey.c
+++ b/bin/dnssec/dnssec-importkey.c
@@ -262,7 +262,7 @@ emit(const char *dir, dns_rdata_t *rdata) {
 	dst_key_free(&key);
 }
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/dnssec/dnssec-keyfromlabel.c b/bin/dnssec/dnssec-keyfromlabel.c
index a4afc1f66a..ce823e8f83 100644
--- a/bin/dnssec/dnssec-keyfromlabel.c
+++ b/bin/dnssec/dnssec-keyfromlabel.c
@@ -43,7 +43,7 @@
 
 const char *program = "dnssec-keyfromlabel";
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/dnssec/dnssec-keygen.c b/bin/dnssec/dnssec-keygen.c
index 5dce14964f..ffcbaba23e 100644
--- a/bin/dnssec/dnssec-keygen.c
+++ b/bin/dnssec/dnssec-keygen.c
@@ -74,7 +74,7 @@ static int min_dh = 128;
 
 isc_log_t *lctx = NULL;
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/dnssec/dnssec-revoke.c b/bin/dnssec/dnssec-revoke.c
index bc2ca62bf2..92169ca7b6 100644
--- a/bin/dnssec/dnssec-revoke.c
+++ b/bin/dnssec/dnssec-revoke.c
@@ -38,7 +38,7 @@ const char *program = "dnssec-revoke";
 
 static isc_mem_t *mctx = NULL;
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/dnssec/dnssec-settime.c b/bin/dnssec/dnssec-settime.c
index 3ca072f0e4..5b630ab115 100644
--- a/bin/dnssec/dnssec-settime.c
+++ b/bin/dnssec/dnssec-settime.c
@@ -42,7 +42,7 @@ const char *program = "dnssec-settime";
 
 static isc_mem_t *mctx = NULL;
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/dnssec/dnssec-signzone.c b/bin/dnssec/dnssec-signzone.c
index e17f85325d..82d4cf0721 100644
--- a/bin/dnssec/dnssec-signzone.c
+++ b/bin/dnssec/dnssec-signzone.c
@@ -3201,7 +3201,7 @@ print_version(FILE *fp) {
 	fprintf(fp, "; %s version %s\n", program, PACKAGE_VERSION);
 }
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/dnssec/dnssec-verify.c b/bin/dnssec/dnssec-verify.c
index 913f463ae5..ce7101c594 100644
--- a/bin/dnssec/dnssec-verify.c
+++ b/bin/dnssec/dnssec-verify.c
@@ -136,7 +136,7 @@ loadzone(char *file, char *origin, dns_rdataclass_t rdclass, dns_db_t **db) {
 	}
 }
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
diff --git a/bin/dnssec/dnssectool.h b/bin/dnssec/dnssectool.h
index aac6a709ad..1107fa7eb1 100644
--- a/bin/dnssec/dnssectool.h
+++ b/bin/dnssec/dnssectool.h
@@ -54,7 +54,7 @@ extern uint8_t dtype[8];
 
 typedef void(fatalcallback_t)(void);
 
-noreturn void
+ISC_NORETURN void
 fatal(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);
 
 void
@@ -66,7 +66,7 @@ check_result(isc_result_t result, const char *message);
 void
 vbprintf(int level, const char *fmt, ...) ISC_FORMAT_PRINTF(2, 3);
 
-noreturn void
+ISC_NORETURN void
 version(const char *program);
 
 void
diff --git a/bin/named/include/named/main.h b/bin/named/include/named/main.h
index bed5dd9787..7cf35e0a21 100644
--- a/bin/named/include/named/main.h
+++ b/bin/named/include/named/main.h
@@ -26,7 +26,7 @@
  */
 #define NAMED_MAIN_ARGS "46A:c:Cd:D:E:fFgL:M:m:n:N:p:sS:t:T:U:u:vVx:X:"
 
-noreturn void
+ISC_NORETURN void
 named_main_earlyfatal(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);
 
 void
diff --git a/bin/named/main.c b/bin/named/main.c
index 274c2bbe2c..0d6af4115a 100644
--- a/bin/named/main.c
+++ b/bin/named/main.c
@@ -197,7 +197,7 @@ named_main_earlyfatal(const char *format, ...) {
 	_exit(EXIT_FAILURE);
 }
 
-noreturn static void
+ISC_NORETURN static void
 assertion_failed(const char *file, int line, isc_assertiontype_t type,
 		 const char *cond);
 
@@ -236,7 +236,7 @@ assertion_failed(const char *file, int line, isc_assertiontype_t type,
 	_exit(EXIT_FAILURE);
 }
 
-noreturn static void
+ISC_NORETURN static void
 library_fatal_error(const char *file, int line, const char *func,
 		    const char *format, va_list args) ISC_FORMAT_PRINTF(3, 0);
 
diff --git a/bin/named/server.c b/bin/named/server.c
index 7739d6b6f8..4081047762 100644
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -426,7 +426,7 @@ const char *empty_zones[] = {
 	NULL
 };
 
-noreturn static void
+ISC_NORETURN static void
 fatal(const char *msg, isc_result_t result);
 
 static void
diff --git a/bin/nsupdate/nsupdate.c b/bin/nsupdate/nsupdate.c
index d23b1c6732..5e06051cf6 100644
--- a/bin/nsupdate/nsupdate.c
+++ b/bin/nsupdate/nsupdate.c
@@ -198,7 +198,7 @@ send_update(dns_name_t *zonename, isc_sockaddr_t *primary);
 static void
 getinput(void *arg);
 
-noreturn static void
+ISC_NORETURN static void
 fatal(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);
 
 static void
diff --git a/bin/rndc/rndc.c b/bin/rndc/rndc.c
index 1d35ded62b..b11fbf47d2 100644
--- a/bin/rndc/rndc.c
+++ b/bin/rndc/rndc.c
@@ -87,7 +87,7 @@ static int32_t timeout = RNDC_TIMEOUT;
 static void
 rndc_startconnect(isc_sockaddr_t *addr);
 
-noreturn static void
+ISC_NORETURN static void
 usage(int status);
 
 static void
diff --git a/bin/rndc/util.h b/bin/rndc/util.h
index 4ac83e5143..0567ad33b1 100644
--- a/bin/rndc/util.h
+++ b/bin/rndc/util.h
@@ -36,7 +36,7 @@ ISC_LANG_BEGINDECLS
 void
 notify(const char *fmt, ...) ISC_FORMAT_PRINTF(1, 2);
 
-noreturn void
+ISC_NORETURN void
 fatal(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);
 
 ISC_LANG_ENDDECLS
diff --git a/bin/tools/dnstap-read.c b/bin/tools/dnstap-read.c
index cbc82c33c5..9127fba967 100644
--- a/bin/tools/dnstap-read.c
+++ b/bin/tools/dnstap-read.c
@@ -72,7 +72,7 @@ const char *program = "dnstap-read";
 		}                                                     \
 	} while (0)
 
-noreturn static void
+ISC_NORETURN static void
 fatal(const char *format, ...);
 
 static void
diff --git a/bin/tools/mdig.c b/bin/tools/mdig.c
index 7a5e9e3948..3c9d9a9377 100644
--- a/bin/tools/mdig.c
+++ b/bin/tools/mdig.c
@@ -775,7 +775,7 @@ sendqueries(void *arg) {
 	}
 }
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
@@ -883,7 +883,7 @@ help(void) {
 	       "Server ID)\n");
 }
 
-noreturn static void
+ISC_NORETURN static void
 fatal(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);
 
 static void
diff --git a/bin/tools/named-rrchecker.c b/bin/tools/named-rrchecker.c
index 563c623be4..d06e4aee2f 100644
--- a/bin/tools/named-rrchecker.c
+++ b/bin/tools/named-rrchecker.c
@@ -35,7 +35,7 @@ static isc_lex_t *lex;
 
 static isc_lexspecials_t specials;
 
-noreturn static void
+ISC_NORETURN static void
 usage(void);
 
 static void
@@ -63,7 +63,7 @@ cleanup(void) {
 	}
 }
 
-noreturn static void
+ISC_NORETURN static void
 fatal(const char *format, ...);
 
 static void
diff --git a/bin/tools/nsec3hash.c b/bin/tools/nsec3hash.c
index 9d77a10d2a..88a47b5acb 100644
--- a/bin/tools/nsec3hash.c
+++ b/bin/tools/nsec3hash.c
@@ -36,7 +36,7 @@
 
 const char *program = "nsec3hash";
 
-noreturn static void
+ISC_NORETURN static void
 fatal(const char *format, ...);
 
 static void
diff --git a/configure.ac b/configure.ac
index 856920226b..738443a42f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -388,10 +388,6 @@ AC_COMPILE_IFELSE(
   ],
   [AC_MSG_FAILURE([stdatomic.h header found, but compilation failed, please fix your toolchain.])])
 
-AC_CHECK_HEADERS([stdnoreturn.h],
-		 [],
-		 [AC_MSG_ERROR([C11 standard headers not found, update your toolchain.])])
-
 AC_C_CONST
 AC_C_INLINE
 AC_C_VOLATILE
@@ -458,11 +454,6 @@ AC_COMPILE_IFELSE(
    AC_MSG_WARN([uname is not correctly supported])
   ])
 
-#
-# check for GCC noreturn attribute
-#
-AX_GCC_FUNC_ATTRIBUTE([noreturn])
-
 #
 # check for GCC malloc attribute
 #
diff --git a/lib/isc/include/isc/assertions.h b/lib/isc/include/isc/assertions.h
index 7eafa16011..03e90414eb 100644
--- a/lib/isc/include/isc/assertions.h
+++ b/lib/isc/include/isc/assertions.h
@@ -33,7 +33,7 @@ typedef void (*isc_assertioncallback_t)(const char *, int, isc_assertiontype_t,
 					const char *);
 
 /* coverity[+kill] */
-noreturn void
+ISC_NORETURN void
 isc_assertion_failed(const char *, int, isc_assertiontype_t, const char *);
 
 void isc_assertion_setcallback(isc_assertioncallback_t);
diff --git a/lib/isc/include/isc/attributes.h b/lib/isc/include/isc/attributes.h
index edb50ed826..eb1bb53e2e 100644
--- a/lib/isc/include/isc/attributes.h
+++ b/lib/isc/include/isc/attributes.h
@@ -21,12 +21,10 @@
 #define __has_c_attribute(x) 0
 #endif /* if !defined(__has_c_attribute) */
 
-#ifdef HAVE_STDNORETURN_H
-#include <stdnoreturn.h>
-#elif HAVE_FUNC_ATTRIBUTE_NORETURN
-#define noreturn __attribute__((noreturn))
+#if __has_c_attribute(noreturn) && __STDC_VERSION__ >= 202311L
+#define ISC_NORETURN [[noreturn]]
 #else
-#define noreturn
+#define ISC_NORETURN _Noreturn
 #endif
 
 #if HAVE_FUNC_ATTRIBUTE_RETURNS_NONNULL
diff --git a/lib/isc/include/isc/error.h b/lib/isc/include/isc/error.h
index f4f668203f..fe7b5c6208 100644
--- a/lib/isc/include/isc/error.h
+++ b/lib/isc/include/isc/error.h
@@ -38,7 +38,7 @@ isc_error_unexpected(const char *, int, const char *, const char *, ...)
 	ISC_FORMAT_PRINTF(4, 5);
 
 /*% fatal error */
-noreturn void
+ISC_NORETURN void
 isc_error_fatal(const char *, int, const char *, const char *, ...)
 	ISC_FORMAT_PRINTF(4, 5);