From 64ff6a9948c01c914e0f8e09ca636c8ca01c4d25 Mon Sep 17 00:00:00 2001
From: Stefan Eissing <stefan@eissing.org>
Date: Tue, 12 Aug 2025 09:33:12 +0200
Subject: [PATCH] error on inability to use ALARMs

just a check on our CI platforms
---
 lib/easy_lock.h |  3 ++-
 lib/hostip.c    | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/lib/easy_lock.h b/lib/easy_lock.h
index 909753f43a..ff8e51a1bf 100644
--- a/lib/easy_lock.h
+++ b/lib/easy_lock.h
@@ -37,6 +37,7 @@
 #define curl_simple_lock_unlock(m) ReleaseSRWLockExclusive(m)
 
 #elif defined(HAVE_ATOMIC) && defined(HAVE_STDATOMIC_H)
+
 #include <stdatomic.h>
 #ifdef HAVE_SCHED_YIELD
 #include <sched.h>
@@ -61,7 +62,7 @@
 #define HAVE_BUILTIN_IA32_PAUSE
 #endif
 
-#endif
+#endif /* !__INTEL_COMPILER */
 
 static CURL_INLINE void curl_simple_lock_lock(curl_simple_lock *lock)
 {
diff --git a/lib/hostip.c b/lib/hostip.c
index 74ed5c0277..66b6ba038d 100644
--- a/lib/hostip.c
+++ b/lib/hostip.c
@@ -78,6 +78,26 @@
 #define USE_ALARM_TIMEOUT
 #endif
 
+#ifndef USE_ALARM_TIMEOUT
+#ifndef CURLRES_SYNCH
+/* disabling USE_ALARM_TIMEOUT because we are not using
+   the SYNCH resolver is fine */
+#endif
+#ifndef HAVE_ALARM
+#error "USE_ALARM_TIMEOUT disabled, HAVE_ALARM not defined"
+#endif
+#ifndef SIGALRM
+#error "USE_ALARM_TIMEOUT disabled, SIGALRM not defined"
+#endif
+#ifndef HAVE_SIGSETJMP
+#error "USE_ALARM_TIMEOUT disabled, HAVE_SIGSETJMP not defined"
+#endif
+#ifndef GLOBAL_INIT_IS_THREADSAFE
+#error "USE_ALARM_TIMEOUT disabled, GLOBAL_INIT_IS_THREADSAFE not defined"
+#endif
+#endif /* !USE_ALARM_TIMEOUT */
+
+
 #define MAX_HOSTCACHE_LEN (255 + 7) /* max FQDN + colon + port number + zero */
 
 #define MAX_DNS_CACHE_SIZE 29999