[Piglit] [PATCH v4] CMake: define GBM_BO_MAP only when symbol is found

[Daniel Díaz]

gbm_bo_map() and _unmap() have been added recently to Mesa,
and this update may not have reached all implementations of
GBM, such as the one provided by Mali r6, where said
definitions can be found in the header file but not in the
library itself. This leads to errors like the following when
linking:
  ../../../../lib/libpiglitutil_gl.so.0: undefined reference to `gbm_bo_unmap'
  ../../../../lib/libpiglitutil_gl.so.0: undefined reference to `gbm_bo_map'
  collect2: error: ld returned 1 exit status
  make[2]: *** [bin/point-sprite] Error 1

Instead of relying on the header file, actually try to link
using that symbol to determine if PIGLIT_HAS_GBM_BO_MAP
should be defined.

Signed-off-by: Daniel Díaz <daniel.diaz at linaro.org>
---
v2: Use CHECK_SYMBOL_EXISTS as suggested by Jan Vesely.
v3: Back to CHECK_FUNCTION_EXISTS.
v4: Use ${GBM_LIBRARIES} instead of 'gbm'.

 CMakeLists.txt | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a4ff99e..cc26fa8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -141,8 +141,9 @@ IF(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
 	if(GBM_FOUND)
 		set(PIGLIT_HAS_GBM True)
 		add_definitions(-DPIGLIT_HAS_GBM)
-		if (GBM_VERSION VERSION_EQUAL "12.1" OR GBM_VERSION VERSION_GREATER "12.1")
-			set(PIGLIT_HAS_GBM_BO_MAP True)
+		set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} ${GBM_LIBRARIES})
+		CHECK_FUNCTION_EXISTS(gbm_bo_map PIGLIT_HAS_GBM_BO_MAP)
+		if (PIGLIT_HAS_GBM_BO_MAP)
 			add_definitions(-DPIGLIT_HAS_GBM_BO_MAP)
 		endif()
 	endif(GBM_FOUND)
-- 
1.9.1