Android: gallium_dri: pass dri.sym to linker

Pass the dri.sym version script to the linker. This ensures only
explicitly exported symbols are exported and shrinks the library by up
to 60KB.

HAVE_DLADDR also needs to be set so that __driDriverExtensions is defined.

We need to pass "--undefined-version" because the Android build system
sets --no-undefined-version by default and we get an error on
driver specific symbols if those drivers are disabled without the option.

Suggested-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Android.common.mk

@@ -64,6 +64,7 @@ LOCAL_CFLAGS += \
 	-DHAVE___BUILTIN_CLZLL \
 	-DHAVE___BUILTIN_UNREACHABLE \
 	-DHAVE_PTHREAD=1 \
+	-DHAVE_DLADDR \
 	-DHAVE_DLOPEN \
 	-DHAVE_DL_ITERATE_PHDR \
 	-DMAJOR_IN_SYSMACROS \

src/gallium/targets/dri/Android.mk

@@ -32,6 +32,13 @@ LOCAL_SRC_FILES := target.c
 
 LOCAL_CFLAGS :=
 
+# We need --undefined-version as some functions in dri.sym may be missing
+# depending on which drivers are enabled or not. Otherwise, we get the error:
+# "version script assignment of  to symbol FOO failed: symbol not defined"
+LOCAL_LDFLAGS := \
+	-Wl,--version-script=$(LOCAL_PATH)/dri.sym \
+	-Wl,--undefined-version
+
 LOCAL_SHARED_LIBRARIES := \
 	libdl \
 	libglapi \