autoconf: Add support for shared DRI build on linux and freebsd

Added autoconf bits to allow using DRI as the driver through the option
--with-dri-driver=DRIVER. The options are x11 (default) and dri. Three
DRI specific options for controlling the driver directory, direct
rendering and TLS are also added.

The DRI will probably not work for platforms besides linux and freebsd.
diff --git a/configure.ac b/configure.ac
index 5563fa2..6c96038 100644
--- a/configure.ac
+++ b/configure.ac
@@ -87,14 +87,44 @@
 AC_SUBST(OSMESA_LIB_NAME)
 
 dnl
-dnl Build directories for xlib driver
+dnl Driver configuration. Options are x11 (Xlib) and dri right now.
+dnl More later: osmesa, directfb, fbdev, ...
+dnl
+AC_ARG_WITH(driver,
+    [AS_HELP_STRING([--with-driver=DRIVER],
+        [driver for Mesa: x11,dri @<:@default=x11@:>@])],
+    mesa_driver="$withval",
+    mesa_driver="x11")
+dnl Check for valid option
+case "x$mesa_driver" in
+xx11|xdri)
+    ;;
+*)
+    AC_MSG_ERROR([Driver '$mesa_driver' is not a valid option])
+    ;;
+esac
+
+dnl
+dnl Driver specific build directories
 dnl
 SRC_DIRS="mesa"
-DRIVER_DIRS="x11 osmesa"
 GLU_DIRS="sgi"
+DRI_DIRS=""
+WINDOW_SYSTEM=""
+case "$mesa_driver" in
+x11)
+    DRIVER_DIRS="x11"
+    ;;
+dri)
+    SRC_DIRS="glx/x11 $SRC_DIRS"
+    DRIVER_DIRS="dri"
+    WINDOW_SYSTEM="dri"
+    ;;
+esac
 AC_SUBST(SRC_DIRS)
 AC_SUBST(GLU_DIRS)
 AC_SUBST(DRIVER_DIRS)
+AC_SUBST(WINDOW_SYSTEM)
 
 dnl
 dnl Find out if X is available. The variables have_x or no_x will be
@@ -119,23 +149,50 @@
     AC_PATH_XTRA
 fi
 
-dnl
-dnl libGL for xlib driver
-dnl
-if test "$no_x" = yes; then
-    AC_MSG_ERROR([X11 development libraries needed for Xlib driver])
-fi
+dnl We need X for xlib and dri, so bomb now if it's not found
+case "$mesa_driver" in
+x11|dri)
+    if test "$no_x" = yes; then
+        AC_MSG_ERROR([X11 development libraries needed for $mesa_driver driver])
+    fi
+    ;;
+esac
 
-if test "$x11_pkgconfig" = yes; then
-PKG_CHECK_MODULES(X11GL, x11 xext)
-    X11_INCLUDES="$X11_INCLUDES $X11GL_CFLAGS"
-    GL_LIB_DEPS="$X11GL_LIBS"
-else
-    # should check these...
-    X11_INCLUDES="$X11_INCLUDES $X_CFLAGS"
-    GL_LIB_DEPS="$X_LIBS -lX11 -lXext"
-fi
-GL_LIB_DEPS="$GL_LIB_DEPS -lm -lpthread"
+dnl
+dnl libGL configuration per driver
+dnl
+case "$mesa_driver" in
+x11)
+    if test "$x11_pkgconfig" = yes; then
+        PKG_CHECK_MODULES(X11GL, x11 xext)
+        X11_INCLUDES="$X11_INCLUDES $X11GL_CFLAGS"
+        GL_LIB_DEPS="$X11GL_LIBS"
+    else
+        # should check these...
+        X11_INCLUDES="$X11_INCLUDES $X_CFLAGS"
+        GL_LIB_DEPS="$X_LIBS -lX11 -lXext"
+    fi
+    GL_LIB_DEPS="$GL_LIB_DEPS -lm -lpthread"
+    ;;
+dri)
+    # Check for libdrm
+    PKG_CHECK_MODULES(LIBDRM, libdrm)
+
+    # find the DRI deps for libGL
+    if test "$x11_pkgconfig" = yes; then
+        PKG_CHECK_MODULES(DRIGL, x11 xext xxf86vm xdamage xfixes)
+        X11_INCLUDES="$X11_INCLUDES $DRIGL_CFLAGS"
+        GL_LIB_DEPS="$DRIGL_LIBS"
+    else
+        # should check these...
+        X11_INCLUDES="$X11_INCLUDES $X_CFLAGS"
+        GL_LIB_DEPS="$X_LIBS -lX11 -lXext -lXxf86vm -lXdamage -lXfixes"
+    fi
+
+    # need DRM libs, -lpthread, etc.
+    GL_LIB_DEPS="$GL_LIB_DEPS $LIBDRM_LIBS -lm -lpthread -ldl"
+    ;;
+esac
 AC_SUBST(GL_LIB_DEPS)
 
 dnl
@@ -146,8 +203,109 @@
 fi
 
 dnl
+dnl More DRI setup
+dnl
+AC_ARG_ENABLE(glx-tls,
+    [AS_HELP_STRING([--enable-glx-tls],
+        [enable TLS support in GLX @<:@default=no@:>@])],
+        GLX_USE_TLS="$enableval",
+        GLX_USE_TLS=no)
+dnl Directory for DRI drivers
+AC_ARG_WITH(dridriverdir,
+    [AS_HELP_STRING([--with-dridriverdir=DIR],
+        [directory for the DRI drivers @<:@/usr/X11R6/lib/modules/dri@:>@])],
+    DRI_DRIVER_INSTALL_DIR="$withval",
+    DRI_DRIVER_INSTALL_DIR='/usr/X11R6/lib/modules/dri')
+AC_SUBST(DRI_DRIVER_INSTALL_DIR)
+dnl Direct rendering or just indirect rendering
+AC_ARG_ENABLE(driglx-direct,
+    [AS_HELP_STRING([--enable-driglx-direct],
+        [enable direct rendering in GLX for DRI @<:@default=yes@:>@])],
+        driglx_direct="$enableval",
+        driglx_direct="yes")
+
+dnl Just default to no EGL for now
+USING_EGL=0
+AC_SUBST(USING_EGL)
+
+dnl Set DRI_DIRS, DEFINES and LIB_DEPS
+if test "$mesa_driver" = dri; then
+    # Use TLS in GLX?
+    if test "x$GLX_USE_TLS" = xyes; then
+        DEFINES="$DEFINES -DGLX_USE_TLS -DPTHREADS"
+    fi
+
+    if test "x$USING_EGL" = x1; then
+        PROGRAM_DIRS="egl"
+    fi
+
+    # Platform specific settings and drivers to build
+    case "$host_os" in
+    linux*)
+        DEFINES="$DEFINES -DUSE_EXTERNAL_DXTN_LIB=1 -DIN_DRI_DRIVER"
+        DEFINES="$DEFINES -DGLX_INDIRECT_RENDERING -DHAVE_ALIAS"
+        if test "x$driglx_direct" = xyes; then
+            DEFINES="$DEFINES -DGLX_DIRECT_RENDERING"
+        fi
+
+        case "$host_cpu" in
+        i*86)
+            DRI_DIRS="i810 i915tex i915 i965 mach64 mga r128 r200 r300 \
+                radeon s3v savage sis tdfx trident unichrome ffb"
+            ;;
+        x86_64)
+            DRI_DIRS="i915tex i915 i965 mach64 mga r128 r200 radeon tdfx \
+                unichrome savage r300"
+            ;;
+        powerpc*)
+            DRI_DIRS="mach64 r128 r200 r300 radeon tdfx"
+            ;;
+        esac
+        ;;
+    freebsd*)
+        DEFINES="$DEFINES -DPTHREADS -DUSE_EXTERNAL_DXTN_LIB=1"
+        DEFINES="$DEFINES -DIN_DRI_DRIVER -DHAVE_ALIAS"
+        DEFINES="$DEFINES -DGLX_INDIRECT_RENDERING"
+        if test "x$driglx_direct" = xyes; then
+            DEFINES="$DEFINES -DGLX_DIRECT_RENDERING"
+        fi
+        if test "x$GXX" = xyes; then
+            CXXFLAGS="$CXXFLAGS -ansi -pedantic"
+        fi
+
+        DRI_DIRS="i810 i915 i965 mach64 mga r128 r200 r300 radeon tdfx \
+            unichrome savage sis"
+        ;;
+    esac
+    DRI_DIRS=`echo "$DRI_DIRS" | $SED 's/  */ /g'`
+
+    # Check for expat
+    EXPAT_INCLUDES=""
+    EXPAT_LIB=-lexpat
+    AC_ARG_WITH(expat, AS_HELP_STRING([--with-expat=DIR],
+            [expat install directory]),[
+        EXPAT_INCLUDES="-I$withval/include"
+        CPPFLAGS="$CPPFLAGS $EXPAT_INCLUDES"
+        LDFLAGS="$LDFLAGS -L$withval/$LIB_DIR"
+        EXPAT_LIB="-L$withval/$LIB_DIR -lexpat"
+        ])
+    AC_CHECK_HEADER(expat.h,,AC_MSG_ERROR([Expat required for DRI.]))
+    AC_CHECK_LIB(expat, XML_ParserCreate,,
+        AC_MSG_ERROR([Expat required for DRI.]))
+
+    # put all the necessary libs together
+    DRI_LIB_DEPS="$LIBDRM_LIBS $EXPAT_LIB -lm -lpthread -ldl"
+fi
+AC_SUBST(DRI_DIRS)
+AC_SUBST(EXPAT_INCLUDES)
+AC_SUBST(DRI_LIB_DEPS)
+
+dnl
 dnl OSMesa configuration
 dnl
+if test "$mesa_driver" = x11; then
+    DRIVER_DIRS="$DRIVER_DIRS osmesa"
+fi
 OSMESA_LIB_DEPS=""
 OSMESA_MESA_DEPS='-l$(GL_LIB)'
 AC_SUBST(OSMESA_LIB_DEPS)