Compile private part as an OBJECT library (CMake concept)

src/CMakeLists.txt

@@ -45,27 +45,6 @@ set( LIBEXIV2_SRC         asfvideo.cpp
                           xmp.cpp
                           xmpsidecar.cpp
                           utilsvideo.cpp
-
-                          cr2image_int.cpp
-                          canonmn_int.cpp
-                          casiomn_int.cpp
-                          crwimage_int.cpp
-                          fujimn_int.cpp
-                          makernote_int.cpp
-                          minoltamn_int.cpp
-                          nikonmn_int.cpp
-                          olympusmn_int.cpp
-                          orfimage_int.cpp
-                          panasonicmn_int.cpp
-                          pentaxmn_int.cpp
-                          rw2image_int.cpp
-                          samsungmn_int.cpp
-                          sigmamn_int.cpp
-                          sonymn_int.cpp
-                          #tags_int.cpp
-                          tiffcomposite_int.cpp
-                          tiffimage_int.cpp
-                          tiffvisitor_int.cpp
    )
 
 # Public C++ header files
@@ -117,6 +96,28 @@ set( LIBEXIV2_HDR         ../include/exiv2/asfvideo.hpp
                           ${CMAKE_BINARY_DIR}/exv_conf.h
    )
 
+set( LIBEXIV2_PRIVATE_SRC cr2image_int.cpp
+                          canonmn_int.cpp
+                          casiomn_int.cpp
+                          crwimage_int.cpp
+                          fujimn_int.cpp
+                          makernote_int.cpp
+                          minoltamn_int.cpp
+                          nikonmn_int.cpp
+                          olympusmn_int.cpp
+                          orfimage_int.cpp
+                          panasonicmn_int.cpp
+                          pentaxmn_int.cpp
+                          rw2image_int.cpp
+                          samsungmn_int.cpp
+                          sigmamn_int.cpp
+                          sonymn_int.cpp
+                          #tags_int.cpp
+                          tiffcomposite_int.cpp
+                          tiffimage_int.cpp
+                          tiffvisitor_int.cpp
+)
+
 # Private headers only needed to build the library
 set( LIBEXIV2_PRIVATE_HDR canonmn_int.hpp
                           casiomn_int.hpp
@@ -159,7 +160,7 @@ endif()
 if( EXIV2_ENABLE_PNG )
     set( LIBEXIV2_SRC ${LIBEXIV2_SRC} pngimage.cpp)
     set( LIBEXIV2_HDR ${LIBEXIV2_HDR} ../include/exiv2/pngimage.hpp )
-    set( LIBEXIV2_SRC ${LIBEXIV2_SRC} pngchunk_int.cpp)
+    set( LIBEXIV2_PRIVATE_SRC ${LIBEXIV2_PRIVATE_SRC} pngchunk_int.cpp)
     set( LIBEXIV2_PRIVATE_HDR ${LIBEXIV2_PRIVATE_HDR} ../include/exiv2/pngimage.hpp)
 endif()
 
@@ -172,7 +173,8 @@ include_directories(${CMAKE_CURRENT_BINARY_DIR})
 # ******************************************************************************
 # exiv2lib library
 
-add_library( exiv2lib ${LIBEXIV2_SRC} ${LIBEXIV2_HDR} ${LIBEXIV2_PRIVATE_HDR})
+add_library( exiv2lib_int OBJECT ${LIBEXIV2_PRIVATE_SRC} ${LIBEXIV2_PRIVATE_HDR})
+add_library( exiv2lib ${LIBEXIV2_SRC} ${LIBEXIV2_HDR} $<TARGET_OBJECTS:exiv2lib_int>)
 
 set_target_properties( exiv2lib PROPERTIES
     VERSION       ${GENERIC_LIB_VERSION}
@@ -181,7 +183,12 @@ set_target_properties( exiv2lib PROPERTIES
     COMPILE_FLAGS ${EXTRA_COMPILE_FLAGS}
 )
 
+set_target_properties( exiv2lib_int PROPERTIES
+    POSITION_INDEPENDENT_CODE ON
+)
+
 target_compile_definitions(exiv2lib PRIVATE EXV_LOCALEDIR="${CMAKE_INSTALL_LOCALEDIR}" EXV_BUILDING_LIB )
+
 if ( BUILD_SHARED_LIBS )
     target_compile_definitions(exiv2lib PRIVATE EXV_HAVE_DLL )
 endif()
@@ -206,6 +213,10 @@ target_include_directories(exiv2lib PUBLIC
     $<INSTALL_INTERFACE:include>
 )
 
+target_include_directories(exiv2lib_int PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_SOURCE_DIR}/include/exiv2>
+)
+
 if (EXIV2_ENABLE_WEBREADY)
 
     if( EXIV2_ENABLE_SSH )