glx: Implement the libglvnd interface.

With reference to the libglvnd branch:

https://cgit.freedesktop.org/mesa/mesa/log/?h=libglvnd

This is a squashed commit containing all of Kyle's commits, all but two
of Emil's commits (to follow), and a small fixup from myself to mark the
rest of the glX* functions as _GLX_PUBLIC so they are not exported when
building for libglvnd. I (ajax) squashed them together both for ease of
review, and because most of the changes are un-useful intermediate
states representing the evolution of glvnd's internal API.

Co-author: Emil Velikov <[email protected]>
Reviewed-by: Adam Jackson <[email protected]>

1 files changed, 47 insertions, 2 deletions

diff --git a/configure.ac b/configure.ac
index fc0b1db2eb5..35fe99a0176 100644
--- a/configure.ac
+++ b/configure.ac
@@ -528,6 +528,34 @@ else
    DEFINES="$DEFINES -DNDEBUG"
 fi
 
+DEFAULT_GL_LIB_NAME=GL
+
+dnl
+dnl Libglvnd configuration
+dnl
+AC_ARG_ENABLE([libglvnd],
+    [AS_HELP_STRING([--enable-libglvnd],
+        [Build for libglvnd @<:@default=disabled@:>@])],
+    [enable_libglvnd="$enableval"],
+    [enable_libglvnd=no])
+AM_CONDITIONAL(USE_LIBGLVND_GLX, test "x$enable_libglvnd" = xyes)
+if test "x$enable_libglvnd" = xyes ; then
+    dnl XXX: update once we can handle more than libGL/glx.
+    dnl Namely: we should error out if neither of the glvnd enabled libraries
+    dnl are built
+    if test "x$enable_glx" = xno; then
+        AC_MSG_ERROR([cannot build libglvnd without GLX])
+    fi
+
+    if test "x$enable_xlib_glx" = xyes; then
+        AC_MSG_ERROR([cannot build libgvnd when Xlib-GLX is enabled])
+    fi
+
+    PKG_CHECK_MODULES([GLVND], libglvnd >= 0.1.0)
+    DEFINES="${DEFINES} -DUSE_LIBGLVND_GLX=1"
+    DEFAULT_GL_LIB_NAME=GLX_mesa
+fi
+
 dnl
 dnl Check if linker supports -Bsymbolic
 dnl
@@ -625,6 +653,23 @@ esac
 
 AM_CONDITIONAL(HAVE_COMPAT_SYMLINKS, test "x$HAVE_COMPAT_SYMLINKS" = xyes)
 
+DEFAULT_GL_LIB_NAME=GL
+
+dnl
+dnl Libglvnd configuration
+dnl
+AC_ARG_ENABLE([libglvnd],
+    [AS_HELP_STRING([--enable-libglvnd],
+        [Build for libglvnd @<:@default=disabled@:>@])],
+    [enable_libglvnd="$enableval"],
+    [enable_libglvnd=no])
+AM_CONDITIONAL(USE_LIBGLVND_GLX, test "x$enable_libglvnd" = xyes)
+#AM_COND_IF([USE_LIBGLVND_GLX], [DEFINES="${DEFINES} -DUSE_LIBGLVND_GLX=1"])
+if test "x$enable_libglvnd" = xyes ; then
+    DEFINES="${DEFINES} -DUSE_LIBGLVND_GLX=1"
+    DEFAULT_GL_LIB_NAME=GLX_mesa
+fi
+
 dnl
 dnl library names
 dnl
@@ -662,13 +707,13 @@ AC_ARG_WITH([gl-lib-name],
   [AS_HELP_STRING([--with-gl-lib-name@<:@=NAME@:>@],
     [specify GL library name @<:@default=GL@:>@])],
   [GL_LIB=$withval],
-  [GL_LIB=GL])
+  [GL_LIB="$DEFAULT_GL_LIB_NAME"])
 AC_ARG_WITH([osmesa-lib-name],
   [AS_HELP_STRING([--with-osmesa-lib-name@<:@=NAME@:>@],
     [specify OSMesa library name @<:@default=OSMesa@:>@])],
   [OSMESA_LIB=$withval],
   [OSMESA_LIB=OSMesa])
-AS_IF([test "x$GL_LIB" = xyes], [GL_LIB=GL])
+AS_IF([test "x$GL_LIB" = xyes], [GL_LIB="$DEFAULT_GL_LIB_NAME"])
 AS_IF([test "x$OSMESA_LIB" = xyes], [OSMESA_LIB=OSMesa])
 
 dnl