cmake: don't use CMAKE_SOURCE_DIR to enable building as subproject

examples/c++/CMakeLists.txt

@@ -9,11 +9,6 @@ add_executable(c++_example2	example2.cpp )
 add_executable(c++_example3	example3.cpp )
 add_executable(c++_example4	example4.cpp )
 
-target_include_directories(c++_example1 PRIVATE ${CMAKE_SOURCE_DIR}/lib)
-target_include_directories(c++_example2 PRIVATE ${CMAKE_SOURCE_DIR}/lib)
-target_include_directories(c++_example3 PRIVATE ${CMAKE_SOURCE_DIR}/lib)
-target_include_directories(c++_example4 PRIVATE ${CMAKE_SOURCE_DIR}/lib)
-
 target_link_libraries(c++_example1 ${libname}++ )
 target_link_libraries(c++_example2 ${libname}++ )
 target_link_libraries(c++_example3 ${libname}++ )

examples/c/CMakeLists.txt

@@ -8,10 +8,6 @@ add_executable(c_example1 example1.c )
 add_executable(c_example2 example2.c )
 add_executable(c_example3 example3.c )
 
-target_include_directories(c_example1 PRIVATE ${CMAKE_SOURCE_DIR}/lib)
-target_include_directories(c_example2 PRIVATE ${CMAKE_SOURCE_DIR}/lib)
-target_include_directories(c_example3 PRIVATE ${CMAKE_SOURCE_DIR}/lib)
-
 target_link_libraries(c_example1 ${libname} )
 target_link_libraries(c_example2 ${libname} )
 target_link_libraries(c_example3 ${libname} )

lib/CMakeLists.txt

@@ -37,6 +37,14 @@ endif()
 add_library(${libname} ${libsrc} ${libinc})
 add_library(${libname}++ ${libsrc_cpp} ${libinc_cpp})
 
+target_include_directories(${libname} PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
+    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+
+target_include_directories(${libname}++ PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
+    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+
 set_target_properties(${libname}
     PROPERTIES LINKER_LANGUAGE C
         PUBLIC_HEADER "${libinc}")

tests/CMakeLists.txt

@@ -4,8 +4,6 @@ else()
     set(libname "config")
 endif()
 
-include_directories(${CMAKE_SOURCE_DIR}/lib)
-
 add_executable(libconfig_tests
     tests.c
 )
@@ -18,5 +16,5 @@ target_link_libraries(libconfig_tests
 add_test(
     NAME libconfig_tests
     COMMAND libconfig_tests
-    WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}/tests
+    WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}/tests
 )