egl: Native Display autodetection
EGL doesnt define howto manage different native platforms.
So mesa has a builtime configurable default platform,
whith non-standard envvar (EGL_PLATFORM) overwrites.
This caused unneeded bugreports, when EGL_PLATFORM was forgotten.
Detection is grouped into basic types of NativeDisplays (which itself
needs to be detected). The final decision is based on characteristcs
of these basic types:
File Desciptor based platforms (fbdev):
- fstat(2) to check for being a fd that belongs to a character device
- check kernel subsystem (todo)
Pointer to structuctures (x11, wayland, drm/gbm):
- mincore(2) to check whether its valid pointer to some memory.
- magic elements (e.g. pointers to exported symbols):
o wayland display stores interface type pointer (first elm.)
o gbm stores pointer to its constructor (first elm.)
o x11 as a fallback (FIXME?)
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
diff --git a/configure.ac b/configure.ac
index 1b1823a..9195da9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1370,6 +1370,8 @@
EGL_LIB_DEPS="$DLOPEN_LIBS $SELINUX_LIBS -lpthread"
EGL_DRIVERS_DIRS=""
+ AC_CHECK_FUNC(mincore, [DEFINES="$DEFINES -DHAVE_MINCORE"])
+
if test "$enable_static" != yes; then
# build egl_glx when libGL is built
if test "x$enable_glx" = xyes; then