Mesa (master): configure: Don't require pthread-stubs on Cygwin

[Jon TURNEY]

Module: Mesa
Branch: master
Commit: 7d8edbaee72969355dc3519b91671ff930e01b2e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=7d8edbaee72969355dc3519b91671ff930e01b2e

Author: Jon Turney <jon.turney at dronecode.org.uk>
Date:   Tue Jun  7 14:22:31 2016 +0000

configure: Don't require pthread-stubs on Cygwin

Commit 1f4869a2 unconditionally requires pthread-stubs.  Unfortunately, the
cleverness that pthread-stubs is doesn't work with PE/COFF, and historically
Cygwin doesn't have a pthread-stubs.pc.

Don't require pthread-stubs on Cygwin.

Signed-off-by: Jon Turney <jon.turney at dronecode.org.uk>

---

 configure.ac | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index c1de4d8..54416b4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -822,9 +822,21 @@ dnl to -pthread, which causes problems if we need -lpthread to appear in
 dnl pkgconfig files.
 test -z "$PTHREAD_LIBS" && PTHREAD_LIBS="-lpthread"
 
-PKG_CHECK_MODULES(PTHREADSTUBS, pthread-stubs)
-AC_SUBST(PTHREADSTUBS_CFLAGS)
-AC_SUBST(PTHREADSTUBS_LIBS)
+dnl pthread-stubs is mandatory on targets where it exists
+case "$host_os" in
+cygwin* )
+    pthread_stubs_possible="no"
+    ;;
+* )
+    pthread_stubs_possible="yes"
+    ;;
+esac
+
+if test "x$pthread_stubs_possible" = xyes; then
+    PKG_CHECK_MODULES(PTHREADSTUBS, pthread-stubs)
+    AC_SUBST(PTHREADSTUBS_CFLAGS)
+    AC_SUBST(PTHREADSTUBS_LIBS)
+fi
 
 dnl SELinux awareness.
 AC_ARG_ENABLE([selinux],