add CMake options for variables

they are just easier to discover this way (see ccmake and IDE
integrations)

CMakeLists.txt

@@ -23,6 +23,7 @@ set(INCLUDE_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/include")
 set(SOURCE_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/src")
 set(TEST_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/test")
 
+option(ENABLE_COVERAGE "Enable -ftest-converage" OFF)
 # enable coverage if requested
 if(ENABLE_COVERAGE)
   message("-- Coverage enabled")
@@ -50,11 +51,13 @@ set_target_properties(cwalk PROPERTIES PUBLIC_HEADER "${INCLUDE_DIRECTORY}/cwalk
 set_target_properties(cwalk PROPERTIES DEFINE_SYMBOL CWK_EXPORTS)
 
 # add shared library macro
+option(BUILD_SHARED_LIBS "build shared libraries" OFF)
 if(BUILD_SHARED_LIBS)
   target_compile_definitions(cwalk PUBLIC CWK_SHARED)
 endif()
 
 # enable tests
+option(ENABLE_TESTS "enable unit tests" OFF)
 if(ENABLE_TESTS)
   message("-- Tests enabled")
   enable_testing()

cmake/EnableWarnings.cmake

@@ -1,4 +1,6 @@
 # enable warnings
+option(IGNORE_WARNINGS "Disable -Werror" OFF)
+
 function(enable_warnings target)
   if(MSVC)
     target_compile_definitions(${target} PRIVATE _CRT_SECURE_NO_WARNINGS)