[PATCH 4/4] build: Update ax_pthread macro

[poljarinho@xxxxxxxxx (poljar (Damir Jelić))]

This patch updates the ax_pthread autoconf macro to the latest version
shipped with autoconf-archive: 2013.06.09.13

This also silences multiple warnings on autoconf 2.68+:
    configure.ac:471: warning: AC_LANG_CONFTEST: no AC_LANG_SOURCE call detected in body
---
 m4/ax_pthread.m4 | 47 +++++++++++++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 16 deletions(-)

diff --git a/m4/ax_pthread.m4 b/m4/ax_pthread.m4
index 94a3b0e..6d400ed 100644
--- a/m4/ax_pthread.m4
+++ b/m4/ax_pthread.m4
@@ -82,7 +82,7 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 14
+#serial 20
 
 AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])
 AC_DEFUN([AX_PTHREAD], [
@@ -145,8 +145,8 @@ ax_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mt
 # --thread-safe: KAI C++
 # pthread-config: use pthread-config program (for GNU Pth library)
 
-case "${host_cpu}-${host_os}" in
-        *solaris*)
+case ${host_os} in
+        solaris*)
 
         # On Solaris (at least, for some versions), libc contains stubbed
         # (non-functional) versions of the pthreads routines, so link-based
@@ -159,7 +159,7 @@ case "${host_cpu}-${host_os}" in
         ax_pthread_flags="-pthreads pthread -mt -pthread $ax_pthread_flags"
         ;;
 
-        *-darwin*)
+        darwin*)
         ax_pthread_flags="-pthread $ax_pthread_flags"
         ;;
 esac
@@ -254,9 +254,16 @@ if test "x$ax_pthread_ok" = xyes; then
 
         AC_MSG_CHECKING([if more special flags are required for pthreads])
         flag=no
-        case "${host_cpu}-${host_os}" in
-            *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
-            *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
+        case ${host_os} in
+            aix* | freebsd* | darwin*) flag="-D_THREAD_SAFE";;
+            osf* | hpux*) flag="-D_REENTRANT";;
+            solaris*)
+            if test "$GCC" = "yes"; then
+                flag="-D_REENTRANT"
+            else
+                flag="-mt -D_REENTRANT"
+            fi
+            ;;
         esac
         AC_MSG_RESULT(${flag})
         if test "x$flag" != xno; then
@@ -265,8 +272,8 @@ if test "x$ax_pthread_ok" = xyes; then
 
         AC_CACHE_CHECK([for PTHREAD_PRIO_INHERIT],
             ax_cv_PTHREAD_PRIO_INHERIT, [
-                AC_LINK_IFELSE(
-                    AC_LANG_PROGRAM([[#include <pthread.h>]], [[int i = PTHREAD_PRIO_INHERIT;]]),
+                AC_LINK_IFELSE([
+                    AC_LANG_PROGRAM([[#include <pthread.h>]], [[int i = PTHREAD_PRIO_INHERIT;]])],
                     [ax_cv_PTHREAD_PRIO_INHERIT=yes],
                     [ax_cv_PTHREAD_PRIO_INHERIT=no])
             ])
@@ -276,16 +283,24 @@ if test "x$ax_pthread_ok" = xyes; then
         LIBS="$save_LIBS"
         CFLAGS="$save_CFLAGS"
 
-        # More AIX lossage: must compile with xlc_r or cc_r
-        if test x"$GCC" != xyes; then
-          AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})
-        else
-          PTHREAD_CC=$CC
+        # More AIX lossage: compile with *_r variant
+        if test "x$GCC" != xyes; then
+            case $host_os in
+                aix*)
+                AS_CASE(["x/$CC"],
+                  [x*/c89|x*/c89_128|x*/c99|x*/c99_128|x*/cc|x*/cc128|x*/xlc|x*/xlc_v6|x*/xlc128|x*/xlc128_v6],
+                  [#handle absolute path differently from PATH based program lookup
+                   AS_CASE(["x$CC"],
+                     [x/*],
+                     [AS_IF([AS_EXECUTABLE_P([${CC}_r])],[PTHREAD_CC="${CC}_r"])],
+                     [AC_CHECK_PROGS([PTHREAD_CC],[${CC}_r],[$CC])])])
+                ;;
+            esac
         fi
-else
-        PTHREAD_CC="$CC"
 fi
 
+test -n "$PTHREAD_CC" || PTHREAD_CC="$CC"
+
 AC_SUBST(PTHREAD_LIBS)
 AC_SUBST(PTHREAD_CFLAGS)
 AC_SUBST(PTHREAD_CC)
-- 
1.8.4