From 478da6ca1aabb23124551830d0bd619eb20b7431 Mon Sep 17 00:00:00 2001
From: Jon TURNEY <jon.turney@dronecode.org.uk>
Date: Wed, 21 Apr 2010 14:42:51 +0100
Subject: [PATCH 2/3] Cygwin: Enable mesa to be built for Cygwin -with-driver=dri with indirect rendering only

Various changes to enable mesa to be built for Cygwin -with-driver=dri with indirect
rendering only rather than -with-driver=xlib

Don't require all platforms to have LIBDRM, but introduce no_drm_is_fatal to make
behaviour on platforms which expect to have DRM available the same as before, i.e.
terminating configure with an error if DRM is not available

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
---
 configure.ac |   28 +++++++++++++++++++++++++---
 1 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index c68b002..d9eac22 100644
--- a/configure.ac
+++ b/configure.ac
@@ -557,6 +557,14 @@ else
     enable_xcb=no
 fi
 
+dnl is DRM expected on the target platform?
+no_drm_is_fatal=yes
+case "$host_os" in
+cygwin*)
+    no_drm_is_fatal=no
+    ;;
+esac
+
 dnl
 dnl libGL configuration per driver
 dnl
@@ -591,11 +599,18 @@ dri)
     fi
 
     # Check for libdrm
-    PKG_CHECK_MODULES([LIBDRM], [libdrm >= $LIBDRM_REQUIRED])
+    PKG_CHECK_MODULES([LIBDRM], [libdrm >= $LIBDRM_REQUIRED], HAVE_LIBDRM=yes, HAVE_LIBDRM=no)
     PKG_CHECK_MODULES([DRI2PROTO], [dri2proto >= $DRI2PROTO_REQUIRED])
     PKG_CHECK_MODULES([GLPROTO], [glproto >= $GLPROTO_REQUIRED])
-    GL_PC_REQ_PRIV="libdrm >= $LIBDRM_REQUIRED dri2proto >= $DRI2PROTO_REQUIRED glproto >= $GLPROTO_REQUIRED"
-    DRI_PC_REQ_PRIV="libdrm >= $LIBDRM_REQUIRED"
+
+    if test "$HAVE_LIBDRM" = no; then
+        if test "$no_drm_is_fatal" = yes; then
+            AC_MSG_ERROR([LIBDRM $LIBDRM_REQUIRED is required by DRI driver])
+        fi
+    else
+        GL_PC_REQ_PRIV="libdrm >= $LIBDRM_REQUIRED dri2proto >= $DRI2PROTO_REQUIRED glproto >= $GLPROTO_REQUIRED"
+        DRI_PC_REQ_PRIV="libdrm >= $LIBDRM_REQUIRED"
+    fi
 
     # find the DRI deps for libGL
     if test "$x11_pkgconfig" = yes; then
@@ -836,6 +851,13 @@ if test "$mesa_driver" = dri; then
             DEFINES="$DEFINES -DGLX_DIRECT_RENDERING"
         fi
         ;;
+    cygwin*)
+        DEFINES="$DEFINES -DUSE_EXTERNAL_DXTN_LIB=1 -DIN_DRI_DRIVER"
+        DEFINES="$DEFINES -DGLX_INDIRECT_RENDERING"
+        if test "x$DRI_DIRS" = "xyes"; then
+            DRI_DIRS="swrast"
+        fi
+        ;;
     esac
 
     # default drivers
-- 
1.7.1