making gdl executable to export its symbols (again) (#2054)

Co-authored-by: Giloo <gildas@localhost>

Author: GillesDuvert

src/CMakeLists.txt

@@ -231,8 +231,6 @@ if(PYTHON_MODULE) #GDL.so
 	SET_TARGET_PROPERTIES(gdl PROPERTIES NO_SONAME TRUE)
         SET_TARGET_PROPERTIES(gdl PROPERTIES SUFFIX ".so") # e.g. Mac defaults to .dylib which is not looked for by Python
 else(PYTHON_MODULE) #GDL.so
-#permit gdl (exe) to export its symbols, necessary for linkimage and DLM
-    set (CMAKE_SHARED_LIBRARY_ENABLE_EXPORTS true)
 	set(SOURCES ${SOURCES} gdl.cpp)
 	add_executable(gdl ${SOURCES})
 endif(PYTHON_MODULE)
@@ -279,17 +277,17 @@ else(PYTHON_MODULE)
 	set_target_properties(gdl PROPERTIES INSTALL_RPATH_USE_LINK_PATH TRUE)
 endif(PYTHON_MODULE)
 
-### replaced by use of CMAKE_SHARED_LIBRARY_ENABLE_EXPORTS above
-### if (NOT APPLE AND NOT OSX AND NOT MINGW)
-###     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--export-dynamic")
-### endif()
-### if (APPLE OR OSX )
-###     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fvisibility=protected") #-exported_symbols_list ${EXPORTED_SYMBOLS_LIST}")
-### endif()
-### if (MINGW )
-###   #set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--export-all-symbols")
-### endif()
-### 
+
+if (NOT APPLE AND NOT OSX AND NOT MINGW)
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--export-dynamic")
+endif()
+if (APPLE OR OSX )
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -fvisibility=protected") #-exported_symbols_list ${EXPORTED_SYMBOLS_LIST}")
+endif()
+if (MINGW )
+  #set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,--export-all-symbols")
+endif()
+
 install(DIRECTORY ${CMAKE_SOURCE_DIR}/src/pro/ DESTINATION ${CMAKE_INSTALL_PREFIX}/${GDL_DATA_DIR}/lib
 	PATTERN CVS EXCLUDE
 	PATTERN checks EXCLUDE