[PATCH] pthread_sigmask: fix implicit declaration of 'pthread_sigmask'

[KO Myung-Hun]

This fixes the following warning:

-----
  CC       lib/pthread_sigmask.o
  lib/pthread_sigmask.c: In function 'rpl_pthread_sigmask':
  lib/pthread_sigmask.c:52:9: warning: implicit declaration of function 
'pthread_sigmask'; did you mean 'rpl_pthread_sigmask'? 
[-Wimplicit-function-declaration]
     52 |   ret = pthread_sigmask (how, new_mask, old_mask_ptr);
        |         ^~~~~~~~~~~~~~~
        |         rpl_pthread_sigmask
-----

* lib/signal.in.h [__KLIBC__]: Include <pthread.h>.
* lib/sys_select.in.h [__KLIBC__]: Do not include <signal.h>.
---
 lib/signal.in.h     | 6 +++---
 lib/sys_select.in.h | 9 ++++++++-
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/lib/signal.in.h b/lib/signal.in.h
index c94b053d6..70a2d4af6 100644
--- a/lib/signal.in.h
+++ b/lib/signal.in.h
@@ -55,13 +55,13 @@
 #ifndef _@GUARD_PREFIX@_SIGNAL_H
 #define _@GUARD_PREFIX@_SIGNAL_H
 
-/* Mac OS X 10.3, FreeBSD 6.4, OpenBSD 3.8, OSF/1 4.0, Solaris 2.6, Android
-   declare pthread_sigmask in <pthread.h>, not in <signal.h>.
+/* Mac OS X 10.3, FreeBSD 6.4, OpenBSD 3.8, OSF/1 4.0, Solaris 2.6, Android,
+   OS/2 kLIBC declare pthread_sigmask in <pthread.h>, not in <signal.h>.
    But avoid namespace pollution on glibc systems.*/
 #if (@GNULIB_PTHREAD_SIGMASK@ || defined GNULIB_POSIXCHECK) \
     && ((defined __APPLE__ && defined __MACH__) \
         || defined __FreeBSD__ || defined __OpenBSD__ || defined __osf__ \
-        || defined __sun || defined __ANDROID__) \
+        || defined __sun || defined __ANDROID__ || defined __KLIBC__) \
     && ! defined __GLIBC__
 # include <pthread.h>
 #endif
diff --git a/lib/sys_select.in.h b/lib/sys_select.in.h
index d625d73e7..034b0f32f 100644
--- a/lib/sys_select.in.h
+++ b/lib/sys_select.in.h
@@ -103,9 +103,16 @@
 /* Get definition of 'sigset_t'.
    But avoid namespace pollution on glibc systems and "unknown type
    name" problems on Cygwin.
+   On OS/2 kLIBC, sigset_t is defined in <sys/select.h>, too. In addition,
+   if <sys/param.h> is included, <types.h> -> <sys/types.h> -> <sys/select.h>
+   are included. Then <signal.h> -> <pthread.h> are included by GNULIB. By the
+   way, <pthread.h> requires PAGE_SIZE defined in <sys/param.h>. However,
+   <sys/param.h> has not been processed, yet. As a result, 'PAGE_SIZE'
+   undeclared error occurs in <pthread.h>.
    Do this after the include_next (for the sake of OpenBSD 5.0) but before
    the split double-inclusion guard (for the sake of Solaris).  */
-#if !((defined __GLIBC__ || defined __CYGWIN__) && !defined __UCLIBC__)
+#if !((defined __GLIBC__ || defined __CYGWIN__ || defined __KLIBC__) \
+      && !defined __UCLIBC__)
 # include <signal.h>
 #endif
 
-- 
2.22.0