configure: Bail out with MinGW targets.

We only support native Windows builds with SCons.

Tested with:

  ./configure --host=i686-w64-mingw32

Reviewed-by: Brian Paul <brianp@vmware.com>

configure.ac

@@ -46,6 +46,13 @@ AC_CONFIG_MACRO_DIR([m4])
 AC_CANONICAL_SYSTEM
 AM_INIT_AUTOMAKE([foreign tar-ustar dist-xz])
 
+dnl We only support native Windows builds (MinGW/MSVC) through SCons.
+case "$host_os" in
+mingw*)
+    AC_MSG_ERROR([MinGW build not supported through autoconf/automake, use SCons instead])
+    ;;
+esac
+
 # Support silent build rules, requires at least automake-1.11. Disable
 # by either passing --disable-silent-rules to configure or passing V=1
 # to make
@@ -651,7 +658,7 @@ AC_CHECK_FUNCS([dladdr])
 LIBS="$save_LIBS"
 
 case "$host_os" in
-darwin*|mingw*)
+darwin*)
     ;;
 *)
     AC_CHECK_FUNCS([clock_gettime], [CLOCK_LIB=],
@@ -665,16 +672,10 @@ dnl See if posix_memalign is available
 AC_CHECK_FUNC([posix_memalign], [DEFINES="$DEFINES -DHAVE_POSIX_MEMALIGN"])
 
 dnl Check for pthreads
-case "$host_os" in
-mingw*)
-    ;;
-*)
-    AX_PTHREAD
-    if test "x$ax_pthread_ok" = xno; then
-        AC_MSG_ERROR([Building mesa on this platform requires pthreads])
-    fi
-    ;;
-esac
+AX_PTHREAD
+if test "x$ax_pthread_ok" = xno; then
+    AC_MSG_ERROR([Building mesa on this platform requires pthreads])
+fi
 dnl AX_PTHREADS leaves PTHREAD_LIBS empty for gcc and sets PTHREAD_CFLAGS
 dnl to -pthread, which causes problems if we need -lpthread to appear in
 dnl pkgconfig files.
@@ -905,7 +906,7 @@ AM_CONDITIONAL(HAVE_DRI_GLX, test "x$enable_glx" = xyes -a \
 case "$host_os" in
 darwin*)
     dri_platform='apple' ;;
-gnu*|mingw*|cygwin*)
+gnu*|cygwin*)
     dri_platform='none' ;;
 *)
     dri_platform='drm' ;;