From: Ken Thomases <ken@codeweavers.com>
Subject: [PATCH 2/3] configure: Check if -lunwind is needed for libunwind.
Message-Id: <096E1242-D3C7-4047-8B11-D841BC25F2C7@codeweavers.com>
Date: Sun, 14 Jun 2015 21:22:59 -0500

---
configure.ac           | 26 ++++++++++++++++++++++++++
dlls/ntdll/Makefile.in |  2 +-
2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index ba52ade..025ff07 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1086,6 +1086,32 @@ WINE_ERROR_WITH(pthread,[test "x$ac_cv_func_pthread_create" != xyes -a "x$PTHREA
 [pthread ${notice_platform}development files not found.
 Wine cannot support threads without libpthread.])
 
+dnl **** Check for libunwind ****
+
+if test "$ac_cv_header_libunwind_h" = "yes"
+then
+    AC_CACHE_CHECK([for libunwind], ac_cv_have_libunwind,
+      [ac_save_LIBS="$LIBS"
+       for lib in '' -lunwind
+       do
+         LIBS="$lib $ac_save_LIBS"
+         AC_LINK_IFELSE([AC_LANG_PROGRAM([[#define UNW_LOCAL_ONLY
+#include <libunwind.h>]],[[unw_cursor_t cursor; unw_context_t context; unw_getcontext(&context); unw_init_local(&cursor, &context);]])],
+           [ac_cv_have_libunwind=${lib:-"none required"}],[ac_cv_have_libunwind="not found"])
+         test "x$ac_cv_have_libunwind" = "xnot found" || break
+       done
+       LIBS="$ac_save_LIBS"])
+
+    case "$ac_cv_have_libunwind" in
+      "not found") ;;
+      "none required")
+        AC_DEFINE(HAVE_LIBUNWIND, 1, [Define if you have libunwind]) ;;
+      *)
+        AC_DEFINE(HAVE_LIBUNWIND, 1)
+        AC_SUBST(UNWIND_LIBS,$ac_cv_have_libunwind) ;;
+    esac
+fi
+
 dnl **** Check for X11 ****
 
 AC_PATH_XTRA
diff --git a/dlls/ntdll/Makefile.in b/dlls/ntdll/Makefile.in
index ed4bb94..08f094a 100644
--- a/dlls/ntdll/Makefile.in
+++ b/dlls/ntdll/Makefile.in
@@ -2,7 +2,7 @@ EXTRADEFS = -D_NTSYSTEM_
 MODULE    = ntdll.dll
 IMPORTLIB = ntdll
 IMPORTS   = winecrt0
-EXTRALIBS = $(IOKIT_LIBS) $(RT_LIBS) $(PTHREAD_LIBS)
+EXTRALIBS = $(IOKIT_LIBS) $(RT_LIBS) $(PTHREAD_LIBS) $(UNWIND_LIBS)
 EXTRADLLFLAGS = -nodefaultlibs -Wl,--image-base,0x7bc00000
 
 C_SRCS = \