From 6e00db58fbeaa09e58c20a606e00b83743e81c7f Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Thu, 3 Apr 2025 10:12:53 +0200
Subject: [PATCH] configure: fix --disable-rt

This option now better only prevents the actual -lrt to be used, and
thus has no effect if the system does not need -lt for the monotonic
clock etc.

Fixes #16932
Closes #16934
---
 acinclude.m4 | 105 ++++++++++++++++++++++++++-------------------------
 configure.ac |   5 ---
 2 files changed, 54 insertions(+), 56 deletions(-)

diff --git a/acinclude.m4 b/acinclude.m4
index abf19c2cd4..53c302cc03 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -807,29 +807,29 @@ AC_DEFUN([CURL_CHECK_FUNC_CLOCK_GETTIME_MONOTONIC], [
   AC_CHECK_HEADERS(sys/types.h sys/time.h)
   AC_MSG_CHECKING([for monotonic clock_gettime])
   #
-  if test "x$dontwant_rt" = "xno" ; then
-    AC_COMPILE_IFELSE([
-      AC_LANG_PROGRAM([[
-        #ifdef HAVE_SYS_TYPES_H
-        #include <sys/types.h>
-        #endif
-        #ifdef HAVE_SYS_TIME_H
-        #include <sys/time.h>
-        #endif
-        #include <time.h>
-      ]],[[
-        struct timespec ts;
-        (void)clock_gettime(CLOCK_MONOTONIC, &ts);
-        (void)ts;
-      ]])
-    ],[
-      AC_MSG_RESULT([yes])
-      curl_func_clock_gettime="yes"
-    ],[
-      AC_MSG_RESULT([no])
-      curl_func_clock_gettime="no"
-    ])
-  fi
+
+  AC_COMPILE_IFELSE([
+    AC_LANG_PROGRAM([[
+      #ifdef HAVE_SYS_TYPES_H
+      #include <sys/types.h>
+      #endif
+      #ifdef HAVE_SYS_TIME_H
+      #include <sys/time.h>
+      #endif
+      #include <time.h>
+    ]],[[
+      struct timespec ts;
+      (void)clock_gettime(CLOCK_MONOTONIC, &ts);
+      (void)ts;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    curl_func_clock_gettime="yes"
+  ],[
+    AC_MSG_RESULT([no])
+    curl_func_clock_gettime="no"
+  ])
+
   dnl Definition of HAVE_CLOCK_GETTIME_MONOTONIC is intentionally postponed
   dnl until library linking and run-time checks for clock_gettime succeed.
 ])
@@ -842,29 +842,27 @@ AC_DEFUN([CURL_CHECK_FUNC_CLOCK_GETTIME_MONOTONIC_RAW], [
   AC_CHECK_HEADERS(sys/types.h sys/time.h)
   AC_MSG_CHECKING([for raw monotonic clock_gettime])
   #
-  if test "x$dontwant_rt" = "xno" ; then
-    AC_COMPILE_IFELSE([
-      AC_LANG_PROGRAM([[
-        #ifdef HAVE_SYS_TYPES_H
-        #include <sys/types.h>
-        #endif
-        #ifdef HAVE_SYS_TIME_H
-        #include <sys/time.h>
-        #endif
-        #include <time.h>
-      ]],[[
-        struct timespec ts;
-        (void)clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
-        (void)ts;
-      ]])
-    ],[
-      AC_MSG_RESULT([yes])
-      AC_DEFINE_UNQUOTED(HAVE_CLOCK_GETTIME_MONOTONIC_RAW, 1,
-        [Define to 1 if you have the clock_gettime function and raw monotonic timer.])
-    ],[
-      AC_MSG_RESULT([no])
-    ])
-  fi
+  AC_COMPILE_IFELSE([
+    AC_LANG_PROGRAM([[
+      #ifdef HAVE_SYS_TYPES_H
+      #include <sys/types.h>
+      #endif
+      #ifdef HAVE_SYS_TIME_H
+      #include <sys/time.h>
+      #endif
+      #include <time.h>
+    ]],[[
+      struct timespec ts;
+      (void)clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
+      (void)ts;
+    ]])
+  ],[
+    AC_MSG_RESULT([yes])
+    AC_DEFINE_UNQUOTED(HAVE_CLOCK_GETTIME_MONOTONIC_RAW, 1,
+      [Define to 1 if you have the clock_gettime function and raw monotonic timer.])
+  ],[
+    AC_MSG_RESULT([no])
+  ])
 ])
 
 
@@ -923,13 +921,18 @@ AC_DEFUN([CURL_CHECK_LIBS_CLOCK_GETTIME_MONOTONIC], [
         curl_func_clock_gettime="yes"
         ;;
       *)
-        if test -z "$curl_cv_save_LIBS"; then
-          LIBS="$curl_cv_gclk_LIBS"
+        if test "x$dontwant_rt" = "xyes" ; then
+          AC_MSG_WARN([needs -lrt but asked not to use it, HAVE_CLOCK_GETTIME_MONOTONIC will not be defined])
+          curl_func_clock_gettime="no"
         else
-          LIBS="$curl_cv_gclk_LIBS $curl_cv_save_LIBS"
+          if test -z "$curl_cv_save_LIBS"; then
+            LIBS="$curl_cv_gclk_LIBS"
+          else
+            LIBS="$curl_cv_gclk_LIBS $curl_cv_save_LIBS"
+          fi
+          AC_MSG_RESULT([$curl_cv_gclk_LIBS])
+          curl_func_clock_gettime="yes"
         fi
-        AC_MSG_RESULT([$curl_cv_gclk_LIBS])
-        curl_func_clock_gettime="yes"
         ;;
     esac
     #
diff --git a/configure.ac b/configure.ac
index 7f5a2bff59..311d2853e6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4203,11 +4203,6 @@ if test "$ipv6" = yes -a "$curl_cv_apple" = 'yes'; then
   CURL_DARWIN_SYSTEMCONFIGURATION
 fi
 
-dnl turn off pthreads if rt is disabled
-if test "$want_threaded_resolver" = "yes" && test "$dontwant_rt" = "yes"; then
-  AC_MSG_ERROR([options --enable-pthreads and --disable-rt are mutually exclusive])
-fi
-
 dnl Windows threaded resolver check
 if test "$want_threaded_resolver" = "yes" && test "$curl_cv_native_windows" = "yes"; then
   USE_THREADS_WIN32=1
-- 
2.47.2