automatically select internal/external tests

- having this as an option is a pain, because even if you haven't set it
  the value is remembered, so if you e.g. change BUILD_SHARED_LIBS you
  would have to explicitly set EAR_UNIT_TESTS

- not all tests depend on the internals, and we should still run the
  external ones if we can. this is not just a good idea from an
  integrity point of view, it also allows us to check that we've added
  exports to the external API

- either way, it should always be possible to run 'make test'
  successfully (unless explicitly disabled), so that if we add more
  tests in any configuration they will get picked up in CI

- cmake generator expressions don't actually work here, because they are
  evaluated when the build system is generated, not while the
  CMakeLists.txt files are being ran

CMakeLists.txt

@@ -33,7 +33,7 @@ SET(CMAKE_SHARED_LINKER_FLAGS_COVERAGE "${CMAKE_SHARED_LINKER_FLAGS_DEBUG} --cov
 include(FeatureSummary)
 option(BUILD_SHARED_LIBS "Build shared libraries rather than static" FALSE)
 option(EAR_HIDE_INTERNAL_SYMBOLS "Hide symbols by default" TRUE)
-option(EAR_UNIT_TESTS "Build units tests" $<AND:${IS_ROOT_PROJECT},$<NOT:${BUILD_SHARED_LIBS}>>)
+option(EAR_UNIT_TESTS "Build units tests" ${IS_ROOT_PROJECT})
 option(EAR_EXAMPLES "Build examples" ${IS_ROOT_PROJECT})
 option(EAR_PACKAGE_AND_INSTALL "Package and install libear" ${IS_ROOT_PROJECT})
 set(INSTALL_LIB_DIR lib CACHE PATH "Installation directory for libraries")
@@ -45,11 +45,10 @@ else()
   set(INSTALL_CMAKE_DIR share/cmake/ear CACHE PATH "Installation directory for CMake files")
 endif()
 
-if(${BUILD_SHARED_LIBS} AND ${EAR_UNIT_TESTS} AND ${EAR_HIDE_INTERNAL_SYMBOLS})
-  message(FATAL_ERROR "\
-    Unit tests need access to internal functions which are not exported by \
-    default for a shared library. Consider disabling EAR_HIDE_INTERNAL_SYMBOLS \
-    to run the unit tests with the shared library of libear.")
+if((NOT BUILD_SHARED_LIBS) OR (NOT EAR_HIDE_INTERNAL_SYMBOLS))
+    SET(EAR_INTERNAL_TESTS TRUE)
+else()
+    SET(EAR_INTERNAL_TESTS FALSE)
 endif()
 
 ############################################################
@@ -77,8 +76,8 @@ if(EAR_EXAMPLES)
 endif()
 
 if(EAR_UNIT_TESTS)
-  include(CTest)
-  add_subdirectory(tests)
+    include(CTest)
+    add_subdirectory(tests)
 endif()
 
 ############################################################
@@ -87,6 +86,8 @@ endif()
 add_feature_info(BUILD_SHARED_LIBS ${BUILD_SHARED_LIBS} "Build shared libraries rather than static")
 add_feature_info(EAR_HIDE_INTERNAL_SYMBOLS ${EAR_HIDE_INTERNAL_SYMBOLS} "Hide symbols by default")
 add_feature_info(EAR_UNIT_TESTS ${EAR_UNIT_TESTS} "Build units tests")
+add_feature_info("Internal Tests" ${EAR_INTERNAL_TESTS}
+    "Build internal tests; requires BUILD_SHARED_LIBS or EAR_HIDE_INTERNAL_SYMBOLS to be FALSE")
 add_feature_info(EAR_EXAMPLES ${EAR_EXAMPLES} "Build examples")
 add_feature_info(EAR_PACKAGE_AND_INSTALL ${EAR_PACKAGE_AND_INSTALL} "Package and install libear")
 feature_summary(WHAT ALL)

tests/CMakeLists.txt

@@ -23,18 +23,21 @@ endfunction()
 # when executed as "test" target
 file(COPY "${CMAKE_CURRENT_SOURCE_DIR}/test_data" DESTINATION ${PROJECT_BINARY_DIR})
 
-add_ear_test("bs2051_tests")
-add_ear_test("decorrelate_tests")
-add_ear_test("extent_tests")
-add_ear_test("eigen_helpers_tests")
-add_ear_test("gain_calculator_objects_tests")
-add_ear_test("gain_calculator_direct_speakers_tests")
-add_ear_test("gain_calculator_hoa_tests")
-add_ear_test("geom_tests")
-add_ear_test("point_source_panner_tests")
-add_ear_test("hoa_tests")
+if(EAR_INTERNAL_TESTS)
+    add_ear_test("decorrelate_tests")
+    add_ear_test("extent_tests")
+    add_ear_test("gain_calculator_direct_speakers_tests")
+    add_ear_test("geom_tests")
+    add_ear_test("hoa_tests")
+    add_ear_test("point_source_panner_tests")
+endif()
+
 add_ear_test("block_convolver_tests")
 target_sources("block_convolver_tests" PRIVATE "block_convolver_test_utils.cpp")
+add_ear_test("bs2051_tests")
 add_ear_test("delay_buffer_tests")
+add_ear_test("eigen_helpers_tests")
+add_ear_test("gain_calculator_hoa_tests")
+add_ear_test("gain_calculator_objects_tests")
 add_ear_test("gain_interpolator_tests")
 add_ear_test("variable_block_size_tests")