Fix pthreads detection when cross-compiling

Author: shivammathur

TSRM/threads.m4

@@ -66,7 +66,7 @@ dnl
 dnl Check whether the current setup can use POSIX threads calls
 dnl
 AC_DEFUN([PTHREADS_CHECK_COMPILE], [
-AC_TRY_RUN( [
+AC_LINK_IFELSE([ AC_LANG_SOURCE([
 #include <pthread.h>
 #include <stddef.h>
 
@@ -80,18 +80,11 @@ int main() {
     int data = 1;
     pthread_mutexattr_init(&mattr);
     return pthread_create(&thd, NULL, thread_routine, &data);
-} ], [
-  pthreads_working=yes
+} ]) ], [
+  pthreads_checked=yes
   ], [
-  pthreads_working=no
-  ], [
-  dnl For cross compiling running this test is of no use. NetWare supports pthreads
-  pthreads_working=no
-  case $host_alias in
-  *netware*)
-    pthreads_working=yes
-  esac
-]
+  pthreads_checked=no
+  ]
 ) ] )dnl
 dnl
 dnl PTHREADS_CHECK()
@@ -129,30 +122,34 @@ else
       CFLAGS="$CFLAGS $flag"
       PTHREADS_CHECK_COMPILE
       CFLAGS=$ac_save
-      if test "$pthreads_working" = "yes"; then
+      if test "$pthreads_checked" = "yes"; then
         ac_cv_pthreads_cflags=$flag
         break
       fi
     done
   fi
-fi
-])
+  ])
+
+  AC_CACHE_CHECK(for pthreads_lib, ac_cv_pthreads_lib,[
+  ac_cv_pthreads_lib=
+  if test "$pthreads_working" != "yes"; then
+   for lib in pthread pthreads c_r; do
+      ac_save=$LIBS
+      LIBS="$LIBS -l$lib"
+      PTHREADS_CHECK_COMPILE
+      LIBS=$ac_save
+      if test "$pthreads_checked" = "yes"; then
+        ac_cv_pthreads_lib=$lib
+        break
+      fi
+    done
+  fi
+  ])
 
-AC_CACHE_CHECK(for pthreads_lib, ac_cv_pthreads_lib,[
-ac_cv_pthreads_lib=
-if test "$pthreads_working" != "yes"; then
-  for lib in pthread pthreads c_r; do
-    ac_save=$LIBS
-    LIBS="$LIBS -l$lib"
-    PTHREADS_CHECK_COMPILE
-    LIBS=$ac_save
-    if test "$pthreads_working" = "yes"; then
-      ac_cv_pthreads_lib=$lib
-      break
-    fi
-  done
+  if test "x$ac_cv_pthreads_cflags" != "x" -o "x$ac_cv_pthreads_lib" != "x"; then
+    pthreads_working="yes"
+  fi
 fi
-])
 
 if test "$pthreads_working" = "yes"; then
   threads_result="POSIX-Threads found"